1 /* 2 * NET3 Protocol independent device support routines. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 7 * 2 of the License, or (at your option) any later version. 8 * 9 * Derived from the non IP parts of dev.c 1.0.19 10 * Authors: Ross Biro 11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 12 * Mark Evans, <evansmp@uhura.aston.ac.uk> 13 * 14 * Additional Authors: 15 * Florian la Roche <rzsfl@rz.uni-sb.de> 16 * Alan Cox <gw4pts@gw4pts.ampr.org> 17 * David Hinds <dahinds@users.sourceforge.net> 18 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> 19 * Adam Sulmicki <adam@cfar.umd.edu> 20 * Pekka Riikonen <priikone@poesidon.pspt.fi> 21 * 22 * Changes: 23 * D.J. Barrow : Fixed bug where dev->refcnt gets set 24 * to 2 if register_netdev gets called 25 * before net_dev_init & also removed a 26 * few lines of code in the process. 27 * Alan Cox : device private ioctl copies fields back. 28 * Alan Cox : Transmit queue code does relevant 29 * stunts to keep the queue safe. 30 * Alan Cox : Fixed double lock. 31 * Alan Cox : Fixed promisc NULL pointer trap 32 * ???????? : Support the full private ioctl range 33 * Alan Cox : Moved ioctl permission check into 34 * drivers 35 * Tim Kordas : SIOCADDMULTI/SIOCDELMULTI 36 * Alan Cox : 100 backlog just doesn't cut it when 37 * you start doing multicast video 8) 38 * Alan Cox : Rewrote net_bh and list manager. 39 * Alan Cox : Fix ETH_P_ALL echoback lengths. 40 * Alan Cox : Took out transmit every packet pass 41 * Saved a few bytes in the ioctl handler 42 * Alan Cox : Network driver sets packet type before 43 * calling netif_rx. Saves a function 44 * call a packet. 45 * Alan Cox : Hashed net_bh() 46 * Richard Kooijman: Timestamp fixes. 47 * Alan Cox : Wrong field in SIOCGIFDSTADDR 48 * Alan Cox : Device lock protection. 49 * Alan Cox : Fixed nasty side effect of device close 50 * changes. 51 * Rudi Cilibrasi : Pass the right thing to 52 * set_mac_address() 53 * Dave Miller : 32bit quantity for the device lock to 54 * make it work out on a Sparc. 55 * Bjorn Ekwall : Added KERNELD hack. 56 * Alan Cox : Cleaned up the backlog initialise. 57 * Craig Metz : SIOCGIFCONF fix if space for under 58 * 1 device. 59 * Thomas Bogendoerfer : Return ENODEV for dev_open, if there 60 * is no device open function. 61 * Andi Kleen : Fix error reporting for SIOCGIFCONF 62 * Michael Chastain : Fix signed/unsigned for SIOCGIFCONF 63 * Cyrus Durgin : Cleaned for KMOD 64 * Adam Sulmicki : Bug Fix : Network Device Unload 65 * A network device unload needs to purge 66 * the backlog queue. 67 * Paul Rusty Russell : SIOCSIFNAME 68 * Pekka Riikonen : Netdev boot-time settings code 69 * Andrew Morton : Make unregister_netdevice wait 70 * indefinitely on dev->refcnt 71 * J Hadi Salim : - Backlog queue sampling 72 * - netif_rx() feedback 73 */ 74 75 #include <asm/uaccess.h> 76 #include <linux/bitops.h> 77 #include <linux/capability.h> 78 #include <linux/cpu.h> 79 #include <linux/types.h> 80 #include <linux/kernel.h> 81 #include <linux/hash.h> 82 #include <linux/slab.h> 83 #include <linux/sched.h> 84 #include <linux/mutex.h> 85 #include <linux/string.h> 86 #include <linux/mm.h> 87 #include <linux/socket.h> 88 #include <linux/sockios.h> 89 #include <linux/errno.h> 90 #include <linux/interrupt.h> 91 #include <linux/if_ether.h> 92 #include <linux/netdevice.h> 93 #include <linux/etherdevice.h> 94 #include <linux/ethtool.h> 95 #include <linux/notifier.h> 96 #include <linux/skbuff.h> 97 #include <net/net_namespace.h> 98 #include <net/sock.h> 99 #include <linux/rtnetlink.h> 100 #include <linux/stat.h> 101 #include <net/dst.h> 102 #include <net/pkt_sched.h> 103 #include <net/checksum.h> 104 #include <net/xfrm.h> 105 #include <linux/highmem.h> 106 #include <linux/init.h> 107 #include <linux/module.h> 108 #include <linux/netpoll.h> 109 #include <linux/rcupdate.h> 110 #include <linux/delay.h> 111 #include <net/iw_handler.h> 112 #include <asm/current.h> 113 #include <linux/audit.h> 114 #include <linux/dmaengine.h> 115 #include <linux/err.h> 116 #include <linux/ctype.h> 117 #include <linux/if_arp.h> 118 #include <linux/if_vlan.h> 119 #include <linux/ip.h> 120 #include <net/ip.h> 121 #include <linux/ipv6.h> 122 #include <linux/in.h> 123 #include <linux/jhash.h> 124 #include <linux/random.h> 125 #include <trace/events/napi.h> 126 #include <trace/events/net.h> 127 #include <trace/events/skb.h> 128 #include <linux/pci.h> 129 #include <linux/inetdevice.h> 130 #include <linux/cpu_rmap.h> 131 #include <linux/static_key.h> 132 #include <linux/hashtable.h> 133 #include <linux/vmalloc.h> 134 #include <linux/if_macvlan.h> 135 136 #include "net-sysfs.h" 137 138 /* Instead of increasing this, you should create a hash table. */ 139 #define MAX_GRO_SKBS 8 140 141 /* This should be increased if a protocol with a bigger head is added. */ 142 #define GRO_MAX_HEAD (MAX_HEADER + 128) 143 144 static DEFINE_SPINLOCK(ptype_lock); 145 static DEFINE_SPINLOCK(offload_lock); 146 struct list_head ptype_base[PTYPE_HASH_SIZE] __read_mostly; 147 struct list_head ptype_all __read_mostly; /* Taps */ 148 static struct list_head offload_base __read_mostly; 149 150 static int netif_rx_internal(struct sk_buff *skb); 151 static int call_netdevice_notifiers_info(unsigned long val, 152 struct net_device *dev, 153 struct netdev_notifier_info *info); 154 155 /* 156 * The @dev_base_head list is protected by @dev_base_lock and the rtnl 157 * semaphore. 158 * 159 * Pure readers hold dev_base_lock for reading, or rcu_read_lock() 160 * 161 * Writers must hold the rtnl semaphore while they loop through the 162 * dev_base_head list, and hold dev_base_lock for writing when they do the 163 * actual updates. This allows pure readers to access the list even 164 * while a writer is preparing to update it. 165 * 166 * To put it another way, dev_base_lock is held for writing only to 167 * protect against pure readers; the rtnl semaphore provides the 168 * protection against other writers. 169 * 170 * See, for example usages, register_netdevice() and 171 * unregister_netdevice(), which must be called with the rtnl 172 * semaphore held. 173 */ 174 DEFINE_RWLOCK(dev_base_lock); 175 EXPORT_SYMBOL(dev_base_lock); 176 177 /* protects napi_hash addition/deletion and napi_gen_id */ 178 static DEFINE_SPINLOCK(napi_hash_lock); 179 180 static unsigned int napi_gen_id; 181 static DEFINE_HASHTABLE(napi_hash, 8); 182 183 static seqcount_t devnet_rename_seq; 184 185 static inline void dev_base_seq_inc(struct net *net) 186 { 187 while (++net->dev_base_seq == 0); 188 } 189 190 static inline struct hlist_head *dev_name_hash(struct net *net, const char *name) 191 { 192 unsigned int hash = full_name_hash(name, strnlen(name, IFNAMSIZ)); 193 194 return &net->dev_name_head[hash_32(hash, NETDEV_HASHBITS)]; 195 } 196 197 static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex) 198 { 199 return &net->dev_index_head[ifindex & (NETDEV_HASHENTRIES - 1)]; 200 } 201 202 static inline void rps_lock(struct softnet_data *sd) 203 { 204 #ifdef CONFIG_RPS 205 spin_lock(&sd->input_pkt_queue.lock); 206 #endif 207 } 208 209 static inline void rps_unlock(struct softnet_data *sd) 210 { 211 #ifdef CONFIG_RPS 212 spin_unlock(&sd->input_pkt_queue.lock); 213 #endif 214 } 215 216 /* Device list insertion */ 217 static void list_netdevice(struct net_device *dev) 218 { 219 struct net *net = dev_net(dev); 220 221 ASSERT_RTNL(); 222 223 write_lock_bh(&dev_base_lock); 224 list_add_tail_rcu(&dev->dev_list, &net->dev_base_head); 225 hlist_add_head_rcu(&dev->name_hlist, dev_name_hash(net, dev->name)); 226 hlist_add_head_rcu(&dev->index_hlist, 227 dev_index_hash(net, dev->ifindex)); 228 write_unlock_bh(&dev_base_lock); 229 230 dev_base_seq_inc(net); 231 } 232 233 /* Device list removal 234 * caller must respect a RCU grace period before freeing/reusing dev 235 */ 236 static void unlist_netdevice(struct net_device *dev) 237 { 238 ASSERT_RTNL(); 239 240 /* Unlink dev from the device chain */ 241 write_lock_bh(&dev_base_lock); 242 list_del_rcu(&dev->dev_list); 243 hlist_del_rcu(&dev->name_hlist); 244 hlist_del_rcu(&dev->index_hlist); 245 write_unlock_bh(&dev_base_lock); 246 247 dev_base_seq_inc(dev_net(dev)); 248 } 249 250 /* 251 * Our notifier list 252 */ 253 254 static RAW_NOTIFIER_HEAD(netdev_chain); 255 256 /* 257 * Device drivers call our routines to queue packets here. We empty the 258 * queue in the local softnet handler. 259 */ 260 261 DEFINE_PER_CPU_ALIGNED(struct softnet_data, softnet_data); 262 EXPORT_PER_CPU_SYMBOL(softnet_data); 263 264 #ifdef CONFIG_LOCKDEP 265 /* 266 * register_netdevice() inits txq->_xmit_lock and sets lockdep class 267 * according to dev->type 268 */ 269 static const unsigned short netdev_lock_type[] = 270 {ARPHRD_NETROM, ARPHRD_ETHER, ARPHRD_EETHER, ARPHRD_AX25, 271 ARPHRD_PRONET, ARPHRD_CHAOS, ARPHRD_IEEE802, ARPHRD_ARCNET, 272 ARPHRD_APPLETLK, ARPHRD_DLCI, ARPHRD_ATM, ARPHRD_METRICOM, 273 ARPHRD_IEEE1394, ARPHRD_EUI64, ARPHRD_INFINIBAND, ARPHRD_SLIP, 274 ARPHRD_CSLIP, ARPHRD_SLIP6, ARPHRD_CSLIP6, ARPHRD_RSRVD, 275 ARPHRD_ADAPT, ARPHRD_ROSE, ARPHRD_X25, ARPHRD_HWX25, 276 ARPHRD_PPP, ARPHRD_CISCO, ARPHRD_LAPB, ARPHRD_DDCMP, 277 ARPHRD_RAWHDLC, ARPHRD_TUNNEL, ARPHRD_TUNNEL6, ARPHRD_FRAD, 278 ARPHRD_SKIP, ARPHRD_LOOPBACK, ARPHRD_LOCALTLK, ARPHRD_FDDI, 279 ARPHRD_BIF, ARPHRD_SIT, ARPHRD_IPDDP, ARPHRD_IPGRE, 280 ARPHRD_PIMREG, ARPHRD_HIPPI, ARPHRD_ASH, ARPHRD_ECONET, 281 ARPHRD_IRDA, ARPHRD_FCPP, ARPHRD_FCAL, ARPHRD_FCPL, 282 ARPHRD_FCFABRIC, ARPHRD_IEEE80211, ARPHRD_IEEE80211_PRISM, 283 ARPHRD_IEEE80211_RADIOTAP, ARPHRD_PHONET, ARPHRD_PHONET_PIPE, 284 ARPHRD_IEEE802154, ARPHRD_VOID, ARPHRD_NONE}; 285 286 static const char *const netdev_lock_name[] = 287 {"_xmit_NETROM", "_xmit_ETHER", "_xmit_EETHER", "_xmit_AX25", 288 "_xmit_PRONET", "_xmit_CHAOS", "_xmit_IEEE802", "_xmit_ARCNET", 289 "_xmit_APPLETLK", "_xmit_DLCI", "_xmit_ATM", "_xmit_METRICOM", 290 "_xmit_IEEE1394", "_xmit_EUI64", "_xmit_INFINIBAND", "_xmit_SLIP", 291 "_xmit_CSLIP", "_xmit_SLIP6", "_xmit_CSLIP6", "_xmit_RSRVD", 292 "_xmit_ADAPT", "_xmit_ROSE", "_xmit_X25", "_xmit_HWX25", 293 "_xmit_PPP", "_xmit_CISCO", "_xmit_LAPB", "_xmit_DDCMP", 294 "_xmit_RAWHDLC", "_xmit_TUNNEL", "_xmit_TUNNEL6", "_xmit_FRAD", 295 "_xmit_SKIP", "_xmit_LOOPBACK", "_xmit_LOCALTLK", "_xmit_FDDI", 296 "_xmit_BIF", "_xmit_SIT", "_xmit_IPDDP", "_xmit_IPGRE", 297 "_xmit_PIMREG", "_xmit_HIPPI", "_xmit_ASH", "_xmit_ECONET", 298 "_xmit_IRDA", "_xmit_FCPP", "_xmit_FCAL", "_xmit_FCPL", 299 "_xmit_FCFABRIC", "_xmit_IEEE80211", "_xmit_IEEE80211_PRISM", 300 "_xmit_IEEE80211_RADIOTAP", "_xmit_PHONET", "_xmit_PHONET_PIPE", 301 "_xmit_IEEE802154", "_xmit_VOID", "_xmit_NONE"}; 302 303 static struct lock_class_key netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)]; 304 static struct lock_class_key netdev_addr_lock_key[ARRAY_SIZE(netdev_lock_type)]; 305 306 static inline unsigned short netdev_lock_pos(unsigned short dev_type) 307 { 308 int i; 309 310 for (i = 0; i < ARRAY_SIZE(netdev_lock_type); i++) 311 if (netdev_lock_type[i] == dev_type) 312 return i; 313 /* the last key is used by default */ 314 return ARRAY_SIZE(netdev_lock_type) - 1; 315 } 316 317 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock, 318 unsigned short dev_type) 319 { 320 int i; 321 322 i = netdev_lock_pos(dev_type); 323 lockdep_set_class_and_name(lock, &netdev_xmit_lock_key[i], 324 netdev_lock_name[i]); 325 } 326 327 static inline void netdev_set_addr_lockdep_class(struct net_device *dev) 328 { 329 int i; 330 331 i = netdev_lock_pos(dev->type); 332 lockdep_set_class_and_name(&dev->addr_list_lock, 333 &netdev_addr_lock_key[i], 334 netdev_lock_name[i]); 335 } 336 #else 337 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock, 338 unsigned short dev_type) 339 { 340 } 341 static inline void netdev_set_addr_lockdep_class(struct net_device *dev) 342 { 343 } 344 #endif 345 346 /******************************************************************************* 347 348 Protocol management and registration routines 349 350 *******************************************************************************/ 351 352 /* 353 * Add a protocol ID to the list. Now that the input handler is 354 * smarter we can dispense with all the messy stuff that used to be 355 * here. 356 * 357 * BEWARE!!! Protocol handlers, mangling input packets, 358 * MUST BE last in hash buckets and checking protocol handlers 359 * MUST start from promiscuous ptype_all chain in net_bh. 360 * It is true now, do not change it. 361 * Explanation follows: if protocol handler, mangling packet, will 362 * be the first on list, it is not able to sense, that packet 363 * is cloned and should be copied-on-write, so that it will 364 * change it and subsequent readers will get broken packet. 365 * --ANK (980803) 366 */ 367 368 static inline struct list_head *ptype_head(const struct packet_type *pt) 369 { 370 if (pt->type == htons(ETH_P_ALL)) 371 return &ptype_all; 372 else 373 return &ptype_base[ntohs(pt->type) & PTYPE_HASH_MASK]; 374 } 375 376 /** 377 * dev_add_pack - add packet handler 378 * @pt: packet type declaration 379 * 380 * Add a protocol handler to the networking stack. The passed &packet_type 381 * is linked into kernel lists and may not be freed until it has been 382 * removed from the kernel lists. 383 * 384 * This call does not sleep therefore it can not 385 * guarantee all CPU's that are in middle of receiving packets 386 * will see the new packet type (until the next received packet). 387 */ 388 389 void dev_add_pack(struct packet_type *pt) 390 { 391 struct list_head *head = ptype_head(pt); 392 393 spin_lock(&ptype_lock); 394 list_add_rcu(&pt->list, head); 395 spin_unlock(&ptype_lock); 396 } 397 EXPORT_SYMBOL(dev_add_pack); 398 399 /** 400 * __dev_remove_pack - remove packet handler 401 * @pt: packet type declaration 402 * 403 * Remove a protocol handler that was previously added to the kernel 404 * protocol handlers by dev_add_pack(). The passed &packet_type is removed 405 * from the kernel lists and can be freed or reused once this function 406 * returns. 407 * 408 * The packet type might still be in use by receivers 409 * and must not be freed until after all the CPU's have gone 410 * through a quiescent state. 411 */ 412 void __dev_remove_pack(struct packet_type *pt) 413 { 414 struct list_head *head = ptype_head(pt); 415 struct packet_type *pt1; 416 417 spin_lock(&ptype_lock); 418 419 list_for_each_entry(pt1, head, list) { 420 if (pt == pt1) { 421 list_del_rcu(&pt->list); 422 goto out; 423 } 424 } 425 426 pr_warn("dev_remove_pack: %p not found\n", pt); 427 out: 428 spin_unlock(&ptype_lock); 429 } 430 EXPORT_SYMBOL(__dev_remove_pack); 431 432 /** 433 * dev_remove_pack - remove packet handler 434 * @pt: packet type declaration 435 * 436 * Remove a protocol handler that was previously added to the kernel 437 * protocol handlers by dev_add_pack(). The passed &packet_type is removed 438 * from the kernel lists and can be freed or reused once this function 439 * returns. 440 * 441 * This call sleeps to guarantee that no CPU is looking at the packet 442 * type after return. 443 */ 444 void dev_remove_pack(struct packet_type *pt) 445 { 446 __dev_remove_pack(pt); 447 448 synchronize_net(); 449 } 450 EXPORT_SYMBOL(dev_remove_pack); 451 452 453 /** 454 * dev_add_offload - register offload handlers 455 * @po: protocol offload declaration 456 * 457 * Add protocol offload handlers to the networking stack. The passed 458 * &proto_offload is linked into kernel lists and may not be freed until 459 * it has been removed from the kernel lists. 460 * 461 * This call does not sleep therefore it can not 462 * guarantee all CPU's that are in middle of receiving packets 463 * will see the new offload handlers (until the next received packet). 464 */ 465 void dev_add_offload(struct packet_offload *po) 466 { 467 struct list_head *head = &offload_base; 468 469 spin_lock(&offload_lock); 470 list_add_rcu(&po->list, head); 471 spin_unlock(&offload_lock); 472 } 473 EXPORT_SYMBOL(dev_add_offload); 474 475 /** 476 * __dev_remove_offload - remove offload handler 477 * @po: packet offload declaration 478 * 479 * Remove a protocol offload handler that was previously added to the 480 * kernel offload handlers by dev_add_offload(). The passed &offload_type 481 * is removed from the kernel lists and can be freed or reused once this 482 * function returns. 483 * 484 * The packet type might still be in use by receivers 485 * and must not be freed until after all the CPU's have gone 486 * through a quiescent state. 487 */ 488 static void __dev_remove_offload(struct packet_offload *po) 489 { 490 struct list_head *head = &offload_base; 491 struct packet_offload *po1; 492 493 spin_lock(&offload_lock); 494 495 list_for_each_entry(po1, head, list) { 496 if (po == po1) { 497 list_del_rcu(&po->list); 498 goto out; 499 } 500 } 501 502 pr_warn("dev_remove_offload: %p not found\n", po); 503 out: 504 spin_unlock(&offload_lock); 505 } 506 507 /** 508 * dev_remove_offload - remove packet offload handler 509 * @po: packet offload declaration 510 * 511 * Remove a packet offload handler that was previously added to the kernel 512 * offload handlers by dev_add_offload(). The passed &offload_type is 513 * removed from the kernel lists and can be freed or reused once this 514 * function returns. 515 * 516 * This call sleeps to guarantee that no CPU is looking at the packet 517 * type after return. 518 */ 519 void dev_remove_offload(struct packet_offload *po) 520 { 521 __dev_remove_offload(po); 522 523 synchronize_net(); 524 } 525 EXPORT_SYMBOL(dev_remove_offload); 526 527 /****************************************************************************** 528 529 Device Boot-time Settings Routines 530 531 *******************************************************************************/ 532 533 /* Boot time configuration table */ 534 static struct netdev_boot_setup dev_boot_setup[NETDEV_BOOT_SETUP_MAX]; 535 536 /** 537 * netdev_boot_setup_add - add new setup entry 538 * @name: name of the device 539 * @map: configured settings for the device 540 * 541 * Adds new setup entry to the dev_boot_setup list. The function 542 * returns 0 on error and 1 on success. This is a generic routine to 543 * all netdevices. 544 */ 545 static int netdev_boot_setup_add(char *name, struct ifmap *map) 546 { 547 struct netdev_boot_setup *s; 548 int i; 549 550 s = dev_boot_setup; 551 for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) { 552 if (s[i].name[0] == '\0' || s[i].name[0] == ' ') { 553 memset(s[i].name, 0, sizeof(s[i].name)); 554 strlcpy(s[i].name, name, IFNAMSIZ); 555 memcpy(&s[i].map, map, sizeof(s[i].map)); 556 break; 557 } 558 } 559 560 return i >= NETDEV_BOOT_SETUP_MAX ? 0 : 1; 561 } 562 563 /** 564 * netdev_boot_setup_check - check boot time settings 565 * @dev: the netdevice 566 * 567 * Check boot time settings for the device. 568 * The found settings are set for the device to be used 569 * later in the device probing. 570 * Returns 0 if no settings found, 1 if they are. 571 */ 572 int netdev_boot_setup_check(struct net_device *dev) 573 { 574 struct netdev_boot_setup *s = dev_boot_setup; 575 int i; 576 577 for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) { 578 if (s[i].name[0] != '\0' && s[i].name[0] != ' ' && 579 !strcmp(dev->name, s[i].name)) { 580 dev->irq = s[i].map.irq; 581 dev->base_addr = s[i].map.base_addr; 582 dev->mem_start = s[i].map.mem_start; 583 dev->mem_end = s[i].map.mem_end; 584 return 1; 585 } 586 } 587 return 0; 588 } 589 EXPORT_SYMBOL(netdev_boot_setup_check); 590 591 592 /** 593 * netdev_boot_base - get address from boot time settings 594 * @prefix: prefix for network device 595 * @unit: id for network device 596 * 597 * Check boot time settings for the base address of device. 598 * The found settings are set for the device to be used 599 * later in the device probing. 600 * Returns 0 if no settings found. 601 */ 602 unsigned long netdev_boot_base(const char *prefix, int unit) 603 { 604 const struct netdev_boot_setup *s = dev_boot_setup; 605 char name[IFNAMSIZ]; 606 int i; 607 608 sprintf(name, "%s%d", prefix, unit); 609 610 /* 611 * If device already registered then return base of 1 612 * to indicate not to probe for this interface 613 */ 614 if (__dev_get_by_name(&init_net, name)) 615 return 1; 616 617 for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) 618 if (!strcmp(name, s[i].name)) 619 return s[i].map.base_addr; 620 return 0; 621 } 622 623 /* 624 * Saves at boot time configured settings for any netdevice. 625 */ 626 int __init netdev_boot_setup(char *str) 627 { 628 int ints[5]; 629 struct ifmap map; 630 631 str = get_options(str, ARRAY_SIZE(ints), ints); 632 if (!str || !*str) 633 return 0; 634 635 /* Save settings */ 636 memset(&map, 0, sizeof(map)); 637 if (ints[0] > 0) 638 map.irq = ints[1]; 639 if (ints[0] > 1) 640 map.base_addr = ints[2]; 641 if (ints[0] > 2) 642 map.mem_start = ints[3]; 643 if (ints[0] > 3) 644 map.mem_end = ints[4]; 645 646 /* Add new entry to the list */ 647 return netdev_boot_setup_add(str, &map); 648 } 649 650 __setup("netdev=", netdev_boot_setup); 651 652 /******************************************************************************* 653 654 Device Interface Subroutines 655 656 *******************************************************************************/ 657 658 /** 659 * __dev_get_by_name - find a device by its name 660 * @net: the applicable net namespace 661 * @name: name to find 662 * 663 * Find an interface by name. Must be called under RTNL semaphore 664 * or @dev_base_lock. If the name is found a pointer to the device 665 * is returned. If the name is not found then %NULL is returned. The 666 * reference counters are not incremented so the caller must be 667 * careful with locks. 668 */ 669 670 struct net_device *__dev_get_by_name(struct net *net, const char *name) 671 { 672 struct net_device *dev; 673 struct hlist_head *head = dev_name_hash(net, name); 674 675 hlist_for_each_entry(dev, head, name_hlist) 676 if (!strncmp(dev->name, name, IFNAMSIZ)) 677 return dev; 678 679 return NULL; 680 } 681 EXPORT_SYMBOL(__dev_get_by_name); 682 683 /** 684 * dev_get_by_name_rcu - find a device by its name 685 * @net: the applicable net namespace 686 * @name: name to find 687 * 688 * Find an interface by name. 689 * If the name is found a pointer to the device is returned. 690 * If the name is not found then %NULL is returned. 691 * The reference counters are not incremented so the caller must be 692 * careful with locks. The caller must hold RCU lock. 693 */ 694 695 struct net_device *dev_get_by_name_rcu(struct net *net, const char *name) 696 { 697 struct net_device *dev; 698 struct hlist_head *head = dev_name_hash(net, name); 699 700 hlist_for_each_entry_rcu(dev, head, name_hlist) 701 if (!strncmp(dev->name, name, IFNAMSIZ)) 702 return dev; 703 704 return NULL; 705 } 706 EXPORT_SYMBOL(dev_get_by_name_rcu); 707 708 /** 709 * dev_get_by_name - find a device by its name 710 * @net: the applicable net namespace 711 * @name: name to find 712 * 713 * Find an interface by name. This can be called from any 714 * context and does its own locking. The returned handle has 715 * the usage count incremented and the caller must use dev_put() to 716 * release it when it is no longer needed. %NULL is returned if no 717 * matching device is found. 718 */ 719 720 struct net_device *dev_get_by_name(struct net *net, const char *name) 721 { 722 struct net_device *dev; 723 724 rcu_read_lock(); 725 dev = dev_get_by_name_rcu(net, name); 726 if (dev) 727 dev_hold(dev); 728 rcu_read_unlock(); 729 return dev; 730 } 731 EXPORT_SYMBOL(dev_get_by_name); 732 733 /** 734 * __dev_get_by_index - find a device by its ifindex 735 * @net: the applicable net namespace 736 * @ifindex: index of device 737 * 738 * Search for an interface by index. Returns %NULL if the device 739 * is not found or a pointer to the device. The device has not 740 * had its reference counter increased so the caller must be careful 741 * about locking. The caller must hold either the RTNL semaphore 742 * or @dev_base_lock. 743 */ 744 745 struct net_device *__dev_get_by_index(struct net *net, int ifindex) 746 { 747 struct net_device *dev; 748 struct hlist_head *head = dev_index_hash(net, ifindex); 749 750 hlist_for_each_entry(dev, head, index_hlist) 751 if (dev->ifindex == ifindex) 752 return dev; 753 754 return NULL; 755 } 756 EXPORT_SYMBOL(__dev_get_by_index); 757 758 /** 759 * dev_get_by_index_rcu - find a device by its ifindex 760 * @net: the applicable net namespace 761 * @ifindex: index of device 762 * 763 * Search for an interface by index. Returns %NULL if the device 764 * is not found or a pointer to the device. The device has not 765 * had its reference counter increased so the caller must be careful 766 * about locking. The caller must hold RCU lock. 767 */ 768 769 struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex) 770 { 771 struct net_device *dev; 772 struct hlist_head *head = dev_index_hash(net, ifindex); 773 774 hlist_for_each_entry_rcu(dev, head, index_hlist) 775 if (dev->ifindex == ifindex) 776 return dev; 777 778 return NULL; 779 } 780 EXPORT_SYMBOL(dev_get_by_index_rcu); 781 782 783 /** 784 * dev_get_by_index - find a device by its ifindex 785 * @net: the applicable net namespace 786 * @ifindex: index of device 787 * 788 * Search for an interface by index. Returns NULL if the device 789 * is not found or a pointer to the device. The device returned has 790 * had a reference added and the pointer is safe until the user calls 791 * dev_put to indicate they have finished with it. 792 */ 793 794 struct net_device *dev_get_by_index(struct net *net, int ifindex) 795 { 796 struct net_device *dev; 797 798 rcu_read_lock(); 799 dev = dev_get_by_index_rcu(net, ifindex); 800 if (dev) 801 dev_hold(dev); 802 rcu_read_unlock(); 803 return dev; 804 } 805 EXPORT_SYMBOL(dev_get_by_index); 806 807 /** 808 * netdev_get_name - get a netdevice name, knowing its ifindex. 809 * @net: network namespace 810 * @name: a pointer to the buffer where the name will be stored. 811 * @ifindex: the ifindex of the interface to get the name from. 812 * 813 * The use of raw_seqcount_begin() and cond_resched() before 814 * retrying is required as we want to give the writers a chance 815 * to complete when CONFIG_PREEMPT is not set. 816 */ 817 int netdev_get_name(struct net *net, char *name, int ifindex) 818 { 819 struct net_device *dev; 820 unsigned int seq; 821 822 retry: 823 seq = raw_seqcount_begin(&devnet_rename_seq); 824 rcu_read_lock(); 825 dev = dev_get_by_index_rcu(net, ifindex); 826 if (!dev) { 827 rcu_read_unlock(); 828 return -ENODEV; 829 } 830 831 strcpy(name, dev->name); 832 rcu_read_unlock(); 833 if (read_seqcount_retry(&devnet_rename_seq, seq)) { 834 cond_resched(); 835 goto retry; 836 } 837 838 return 0; 839 } 840 841 /** 842 * dev_getbyhwaddr_rcu - find a device by its hardware address 843 * @net: the applicable net namespace 844 * @type: media type of device 845 * @ha: hardware address 846 * 847 * Search for an interface by MAC address. Returns NULL if the device 848 * is not found or a pointer to the device. 849 * The caller must hold RCU or RTNL. 850 * The returned device has not had its ref count increased 851 * and the caller must therefore be careful about locking 852 * 853 */ 854 855 struct net_device *dev_getbyhwaddr_rcu(struct net *net, unsigned short type, 856 const char *ha) 857 { 858 struct net_device *dev; 859 860 for_each_netdev_rcu(net, dev) 861 if (dev->type == type && 862 !memcmp(dev->dev_addr, ha, dev->addr_len)) 863 return dev; 864 865 return NULL; 866 } 867 EXPORT_SYMBOL(dev_getbyhwaddr_rcu); 868 869 struct net_device *__dev_getfirstbyhwtype(struct net *net, unsigned short type) 870 { 871 struct net_device *dev; 872 873 ASSERT_RTNL(); 874 for_each_netdev(net, dev) 875 if (dev->type == type) 876 return dev; 877 878 return NULL; 879 } 880 EXPORT_SYMBOL(__dev_getfirstbyhwtype); 881 882 struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type) 883 { 884 struct net_device *dev, *ret = NULL; 885 886 rcu_read_lock(); 887 for_each_netdev_rcu(net, dev) 888 if (dev->type == type) { 889 dev_hold(dev); 890 ret = dev; 891 break; 892 } 893 rcu_read_unlock(); 894 return ret; 895 } 896 EXPORT_SYMBOL(dev_getfirstbyhwtype); 897 898 /** 899 * dev_get_by_flags_rcu - find any device with given flags 900 * @net: the applicable net namespace 901 * @if_flags: IFF_* values 902 * @mask: bitmask of bits in if_flags to check 903 * 904 * Search for any interface with the given flags. Returns NULL if a device 905 * is not found or a pointer to the device. Must be called inside 906 * rcu_read_lock(), and result refcount is unchanged. 907 */ 908 909 struct net_device *dev_get_by_flags_rcu(struct net *net, unsigned short if_flags, 910 unsigned short mask) 911 { 912 struct net_device *dev, *ret; 913 914 ret = NULL; 915 for_each_netdev_rcu(net, dev) { 916 if (((dev->flags ^ if_flags) & mask) == 0) { 917 ret = dev; 918 break; 919 } 920 } 921 return ret; 922 } 923 EXPORT_SYMBOL(dev_get_by_flags_rcu); 924 925 /** 926 * dev_valid_name - check if name is okay for network device 927 * @name: name string 928 * 929 * Network device names need to be valid file names to 930 * to allow sysfs to work. We also disallow any kind of 931 * whitespace. 932 */ 933 bool dev_valid_name(const char *name) 934 { 935 if (*name == '\0') 936 return false; 937 if (strlen(name) >= IFNAMSIZ) 938 return false; 939 if (!strcmp(name, ".") || !strcmp(name, "..")) 940 return false; 941 942 while (*name) { 943 if (*name == '/' || isspace(*name)) 944 return false; 945 name++; 946 } 947 return true; 948 } 949 EXPORT_SYMBOL(dev_valid_name); 950 951 /** 952 * __dev_alloc_name - allocate a name for a device 953 * @net: network namespace to allocate the device name in 954 * @name: name format string 955 * @buf: scratch buffer and result name string 956 * 957 * Passed a format string - eg "lt%d" it will try and find a suitable 958 * id. It scans list of devices to build up a free map, then chooses 959 * the first empty slot. The caller must hold the dev_base or rtnl lock 960 * while allocating the name and adding the device in order to avoid 961 * duplicates. 962 * Limited to bits_per_byte * page size devices (ie 32K on most platforms). 963 * Returns the number of the unit assigned or a negative errno code. 964 */ 965 966 static int __dev_alloc_name(struct net *net, const char *name, char *buf) 967 { 968 int i = 0; 969 const char *p; 970 const int max_netdevices = 8*PAGE_SIZE; 971 unsigned long *inuse; 972 struct net_device *d; 973 974 p = strnchr(name, IFNAMSIZ-1, '%'); 975 if (p) { 976 /* 977 * Verify the string as this thing may have come from 978 * the user. There must be either one "%d" and no other "%" 979 * characters. 980 */ 981 if (p[1] != 'd' || strchr(p + 2, '%')) 982 return -EINVAL; 983 984 /* Use one page as a bit array of possible slots */ 985 inuse = (unsigned long *) get_zeroed_page(GFP_ATOMIC); 986 if (!inuse) 987 return -ENOMEM; 988 989 for_each_netdev(net, d) { 990 if (!sscanf(d->name, name, &i)) 991 continue; 992 if (i < 0 || i >= max_netdevices) 993 continue; 994 995 /* avoid cases where sscanf is not exact inverse of printf */ 996 snprintf(buf, IFNAMSIZ, name, i); 997 if (!strncmp(buf, d->name, IFNAMSIZ)) 998 set_bit(i, inuse); 999 } 1000 1001 i = find_first_zero_bit(inuse, max_netdevices); 1002 free_page((unsigned long) inuse); 1003 } 1004 1005 if (buf != name) 1006 snprintf(buf, IFNAMSIZ, name, i); 1007 if (!__dev_get_by_name(net, buf)) 1008 return i; 1009 1010 /* It is possible to run out of possible slots 1011 * when the name is long and there isn't enough space left 1012 * for the digits, or if all bits are used. 1013 */ 1014 return -ENFILE; 1015 } 1016 1017 /** 1018 * dev_alloc_name - allocate a name for a device 1019 * @dev: device 1020 * @name: name format string 1021 * 1022 * Passed a format string - eg "lt%d" it will try and find a suitable 1023 * id. It scans list of devices to build up a free map, then chooses 1024 * the first empty slot. The caller must hold the dev_base or rtnl lock 1025 * while allocating the name and adding the device in order to avoid 1026 * duplicates. 1027 * Limited to bits_per_byte * page size devices (ie 32K on most platforms). 1028 * Returns the number of the unit assigned or a negative errno code. 1029 */ 1030 1031 int dev_alloc_name(struct net_device *dev, const char *name) 1032 { 1033 char buf[IFNAMSIZ]; 1034 struct net *net; 1035 int ret; 1036 1037 BUG_ON(!dev_net(dev)); 1038 net = dev_net(dev); 1039 ret = __dev_alloc_name(net, name, buf); 1040 if (ret >= 0) 1041 strlcpy(dev->name, buf, IFNAMSIZ); 1042 return ret; 1043 } 1044 EXPORT_SYMBOL(dev_alloc_name); 1045 1046 static int dev_alloc_name_ns(struct net *net, 1047 struct net_device *dev, 1048 const char *name) 1049 { 1050 char buf[IFNAMSIZ]; 1051 int ret; 1052 1053 ret = __dev_alloc_name(net, name, buf); 1054 if (ret >= 0) 1055 strlcpy(dev->name, buf, IFNAMSIZ); 1056 return ret; 1057 } 1058 1059 static int dev_get_valid_name(struct net *net, 1060 struct net_device *dev, 1061 const char *name) 1062 { 1063 BUG_ON(!net); 1064 1065 if (!dev_valid_name(name)) 1066 return -EINVAL; 1067 1068 if (strchr(name, '%')) 1069 return dev_alloc_name_ns(net, dev, name); 1070 else if (__dev_get_by_name(net, name)) 1071 return -EEXIST; 1072 else if (dev->name != name) 1073 strlcpy(dev->name, name, IFNAMSIZ); 1074 1075 return 0; 1076 } 1077 1078 /** 1079 * dev_change_name - change name of a device 1080 * @dev: device 1081 * @newname: name (or format string) must be at least IFNAMSIZ 1082 * 1083 * Change name of a device, can pass format strings "eth%d". 1084 * for wildcarding. 1085 */ 1086 int dev_change_name(struct net_device *dev, const char *newname) 1087 { 1088 char oldname[IFNAMSIZ]; 1089 int err = 0; 1090 int ret; 1091 struct net *net; 1092 1093 ASSERT_RTNL(); 1094 BUG_ON(!dev_net(dev)); 1095 1096 net = dev_net(dev); 1097 if (dev->flags & IFF_UP) 1098 return -EBUSY; 1099 1100 write_seqcount_begin(&devnet_rename_seq); 1101 1102 if (strncmp(newname, dev->name, IFNAMSIZ) == 0) { 1103 write_seqcount_end(&devnet_rename_seq); 1104 return 0; 1105 } 1106 1107 memcpy(oldname, dev->name, IFNAMSIZ); 1108 1109 err = dev_get_valid_name(net, dev, newname); 1110 if (err < 0) { 1111 write_seqcount_end(&devnet_rename_seq); 1112 return err; 1113 } 1114 1115 rollback: 1116 ret = device_rename(&dev->dev, dev->name); 1117 if (ret) { 1118 memcpy(dev->name, oldname, IFNAMSIZ); 1119 write_seqcount_end(&devnet_rename_seq); 1120 return ret; 1121 } 1122 1123 write_seqcount_end(&devnet_rename_seq); 1124 1125 netdev_adjacent_rename_links(dev, oldname); 1126 1127 write_lock_bh(&dev_base_lock); 1128 hlist_del_rcu(&dev->name_hlist); 1129 write_unlock_bh(&dev_base_lock); 1130 1131 synchronize_rcu(); 1132 1133 write_lock_bh(&dev_base_lock); 1134 hlist_add_head_rcu(&dev->name_hlist, dev_name_hash(net, dev->name)); 1135 write_unlock_bh(&dev_base_lock); 1136 1137 ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev); 1138 ret = notifier_to_errno(ret); 1139 1140 if (ret) { 1141 /* err >= 0 after dev_alloc_name() or stores the first errno */ 1142 if (err >= 0) { 1143 err = ret; 1144 write_seqcount_begin(&devnet_rename_seq); 1145 memcpy(dev->name, oldname, IFNAMSIZ); 1146 memcpy(oldname, newname, IFNAMSIZ); 1147 goto rollback; 1148 } else { 1149 pr_err("%s: name change rollback failed: %d\n", 1150 dev->name, ret); 1151 } 1152 } 1153 1154 return err; 1155 } 1156 1157 /** 1158 * dev_set_alias - change ifalias of a device 1159 * @dev: device 1160 * @alias: name up to IFALIASZ 1161 * @len: limit of bytes to copy from info 1162 * 1163 * Set ifalias for a device, 1164 */ 1165 int dev_set_alias(struct net_device *dev, const char *alias, size_t len) 1166 { 1167 char *new_ifalias; 1168 1169 ASSERT_RTNL(); 1170 1171 if (len >= IFALIASZ) 1172 return -EINVAL; 1173 1174 if (!len) { 1175 kfree(dev->ifalias); 1176 dev->ifalias = NULL; 1177 return 0; 1178 } 1179 1180 new_ifalias = krealloc(dev->ifalias, len + 1, GFP_KERNEL); 1181 if (!new_ifalias) 1182 return -ENOMEM; 1183 dev->ifalias = new_ifalias; 1184 1185 strlcpy(dev->ifalias, alias, len+1); 1186 return len; 1187 } 1188 1189 1190 /** 1191 * netdev_features_change - device changes features 1192 * @dev: device to cause notification 1193 * 1194 * Called to indicate a device has changed features. 1195 */ 1196 void netdev_features_change(struct net_device *dev) 1197 { 1198 call_netdevice_notifiers(NETDEV_FEAT_CHANGE, dev); 1199 } 1200 EXPORT_SYMBOL(netdev_features_change); 1201 1202 /** 1203 * netdev_state_change - device changes state 1204 * @dev: device to cause notification 1205 * 1206 * Called to indicate a device has changed state. This function calls 1207 * the notifier chains for netdev_chain and sends a NEWLINK message 1208 * to the routing socket. 1209 */ 1210 void netdev_state_change(struct net_device *dev) 1211 { 1212 if (dev->flags & IFF_UP) { 1213 struct netdev_notifier_change_info change_info; 1214 1215 change_info.flags_changed = 0; 1216 call_netdevice_notifiers_info(NETDEV_CHANGE, dev, 1217 &change_info.info); 1218 rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL); 1219 } 1220 } 1221 EXPORT_SYMBOL(netdev_state_change); 1222 1223 /** 1224 * netdev_notify_peers - notify network peers about existence of @dev 1225 * @dev: network device 1226 * 1227 * Generate traffic such that interested network peers are aware of 1228 * @dev, such as by generating a gratuitous ARP. This may be used when 1229 * a device wants to inform the rest of the network about some sort of 1230 * reconfiguration such as a failover event or virtual machine 1231 * migration. 1232 */ 1233 void netdev_notify_peers(struct net_device *dev) 1234 { 1235 rtnl_lock(); 1236 call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev); 1237 rtnl_unlock(); 1238 } 1239 EXPORT_SYMBOL(netdev_notify_peers); 1240 1241 static int __dev_open(struct net_device *dev) 1242 { 1243 const struct net_device_ops *ops = dev->netdev_ops; 1244 int ret; 1245 1246 ASSERT_RTNL(); 1247 1248 if (!netif_device_present(dev)) 1249 return -ENODEV; 1250 1251 /* Block netpoll from trying to do any rx path servicing. 1252 * If we don't do this there is a chance ndo_poll_controller 1253 * or ndo_poll may be running while we open the device 1254 */ 1255 netpoll_poll_disable(dev); 1256 1257 ret = call_netdevice_notifiers(NETDEV_PRE_UP, dev); 1258 ret = notifier_to_errno(ret); 1259 if (ret) 1260 return ret; 1261 1262 set_bit(__LINK_STATE_START, &dev->state); 1263 1264 if (ops->ndo_validate_addr) 1265 ret = ops->ndo_validate_addr(dev); 1266 1267 if (!ret && ops->ndo_open) 1268 ret = ops->ndo_open(dev); 1269 1270 netpoll_poll_enable(dev); 1271 1272 if (ret) 1273 clear_bit(__LINK_STATE_START, &dev->state); 1274 else { 1275 dev->flags |= IFF_UP; 1276 net_dmaengine_get(); 1277 dev_set_rx_mode(dev); 1278 dev_activate(dev); 1279 add_device_randomness(dev->dev_addr, dev->addr_len); 1280 } 1281 1282 return ret; 1283 } 1284 1285 /** 1286 * dev_open - prepare an interface for use. 1287 * @dev: device to open 1288 * 1289 * Takes a device from down to up state. The device's private open 1290 * function is invoked and then the multicast lists are loaded. Finally 1291 * the device is moved into the up state and a %NETDEV_UP message is 1292 * sent to the netdev notifier chain. 1293 * 1294 * Calling this function on an active interface is a nop. On a failure 1295 * a negative errno code is returned. 1296 */ 1297 int dev_open(struct net_device *dev) 1298 { 1299 int ret; 1300 1301 if (dev->flags & IFF_UP) 1302 return 0; 1303 1304 ret = __dev_open(dev); 1305 if (ret < 0) 1306 return ret; 1307 1308 rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING, GFP_KERNEL); 1309 call_netdevice_notifiers(NETDEV_UP, dev); 1310 1311 return ret; 1312 } 1313 EXPORT_SYMBOL(dev_open); 1314 1315 static int __dev_close_many(struct list_head *head) 1316 { 1317 struct net_device *dev; 1318 1319 ASSERT_RTNL(); 1320 might_sleep(); 1321 1322 list_for_each_entry(dev, head, close_list) { 1323 /* Temporarily disable netpoll until the interface is down */ 1324 netpoll_poll_disable(dev); 1325 1326 call_netdevice_notifiers(NETDEV_GOING_DOWN, dev); 1327 1328 clear_bit(__LINK_STATE_START, &dev->state); 1329 1330 /* Synchronize to scheduled poll. We cannot touch poll list, it 1331 * can be even on different cpu. So just clear netif_running(). 1332 * 1333 * dev->stop() will invoke napi_disable() on all of it's 1334 * napi_struct instances on this device. 1335 */ 1336 smp_mb__after_atomic(); /* Commit netif_running(). */ 1337 } 1338 1339 dev_deactivate_many(head); 1340 1341 list_for_each_entry(dev, head, close_list) { 1342 const struct net_device_ops *ops = dev->netdev_ops; 1343 1344 /* 1345 * Call the device specific close. This cannot fail. 1346 * Only if device is UP 1347 * 1348 * We allow it to be called even after a DETACH hot-plug 1349 * event. 1350 */ 1351 if (ops->ndo_stop) 1352 ops->ndo_stop(dev); 1353 1354 dev->flags &= ~IFF_UP; 1355 net_dmaengine_put(); 1356 netpoll_poll_enable(dev); 1357 } 1358 1359 return 0; 1360 } 1361 1362 static int __dev_close(struct net_device *dev) 1363 { 1364 int retval; 1365 LIST_HEAD(single); 1366 1367 list_add(&dev->close_list, &single); 1368 retval = __dev_close_many(&single); 1369 list_del(&single); 1370 1371 return retval; 1372 } 1373 1374 static int dev_close_many(struct list_head *head) 1375 { 1376 struct net_device *dev, *tmp; 1377 1378 /* Remove the devices that don't need to be closed */ 1379 list_for_each_entry_safe(dev, tmp, head, close_list) 1380 if (!(dev->flags & IFF_UP)) 1381 list_del_init(&dev->close_list); 1382 1383 __dev_close_many(head); 1384 1385 list_for_each_entry_safe(dev, tmp, head, close_list) { 1386 rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING, GFP_KERNEL); 1387 call_netdevice_notifiers(NETDEV_DOWN, dev); 1388 list_del_init(&dev->close_list); 1389 } 1390 1391 return 0; 1392 } 1393 1394 /** 1395 * dev_close - shutdown an interface. 1396 * @dev: device to shutdown 1397 * 1398 * This function moves an active device into down state. A 1399 * %NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device 1400 * is then deactivated and finally a %NETDEV_DOWN is sent to the notifier 1401 * chain. 1402 */ 1403 int dev_close(struct net_device *dev) 1404 { 1405 if (dev->flags & IFF_UP) { 1406 LIST_HEAD(single); 1407 1408 list_add(&dev->close_list, &single); 1409 dev_close_many(&single); 1410 list_del(&single); 1411 } 1412 return 0; 1413 } 1414 EXPORT_SYMBOL(dev_close); 1415 1416 1417 /** 1418 * dev_disable_lro - disable Large Receive Offload on a device 1419 * @dev: device 1420 * 1421 * Disable Large Receive Offload (LRO) on a net device. Must be 1422 * called under RTNL. This is needed if received packets may be 1423 * forwarded to another interface. 1424 */ 1425 void dev_disable_lro(struct net_device *dev) 1426 { 1427 /* 1428 * If we're trying to disable lro on a vlan device 1429 * use the underlying physical device instead 1430 */ 1431 if (is_vlan_dev(dev)) 1432 dev = vlan_dev_real_dev(dev); 1433 1434 /* the same for macvlan devices */ 1435 if (netif_is_macvlan(dev)) 1436 dev = macvlan_dev_real_dev(dev); 1437 1438 dev->wanted_features &= ~NETIF_F_LRO; 1439 netdev_update_features(dev); 1440 1441 if (unlikely(dev->features & NETIF_F_LRO)) 1442 netdev_WARN(dev, "failed to disable LRO!\n"); 1443 } 1444 EXPORT_SYMBOL(dev_disable_lro); 1445 1446 static int call_netdevice_notifier(struct notifier_block *nb, unsigned long val, 1447 struct net_device *dev) 1448 { 1449 struct netdev_notifier_info info; 1450 1451 netdev_notifier_info_init(&info, dev); 1452 return nb->notifier_call(nb, val, &info); 1453 } 1454 1455 static int dev_boot_phase = 1; 1456 1457 /** 1458 * register_netdevice_notifier - register a network notifier block 1459 * @nb: notifier 1460 * 1461 * Register a notifier to be called when network device events occur. 1462 * The notifier passed is linked into the kernel structures and must 1463 * not be reused until it has been unregistered. A negative errno code 1464 * is returned on a failure. 1465 * 1466 * When registered all registration and up events are replayed 1467 * to the new notifier to allow device to have a race free 1468 * view of the network device list. 1469 */ 1470 1471 int register_netdevice_notifier(struct notifier_block *nb) 1472 { 1473 struct net_device *dev; 1474 struct net_device *last; 1475 struct net *net; 1476 int err; 1477 1478 rtnl_lock(); 1479 err = raw_notifier_chain_register(&netdev_chain, nb); 1480 if (err) 1481 goto unlock; 1482 if (dev_boot_phase) 1483 goto unlock; 1484 for_each_net(net) { 1485 for_each_netdev(net, dev) { 1486 err = call_netdevice_notifier(nb, NETDEV_REGISTER, dev); 1487 err = notifier_to_errno(err); 1488 if (err) 1489 goto rollback; 1490 1491 if (!(dev->flags & IFF_UP)) 1492 continue; 1493 1494 call_netdevice_notifier(nb, NETDEV_UP, dev); 1495 } 1496 } 1497 1498 unlock: 1499 rtnl_unlock(); 1500 return err; 1501 1502 rollback: 1503 last = dev; 1504 for_each_net(net) { 1505 for_each_netdev(net, dev) { 1506 if (dev == last) 1507 goto outroll; 1508 1509 if (dev->flags & IFF_UP) { 1510 call_netdevice_notifier(nb, NETDEV_GOING_DOWN, 1511 dev); 1512 call_netdevice_notifier(nb, NETDEV_DOWN, dev); 1513 } 1514 call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev); 1515 } 1516 } 1517 1518 outroll: 1519 raw_notifier_chain_unregister(&netdev_chain, nb); 1520 goto unlock; 1521 } 1522 EXPORT_SYMBOL(register_netdevice_notifier); 1523 1524 /** 1525 * unregister_netdevice_notifier - unregister a network notifier block 1526 * @nb: notifier 1527 * 1528 * Unregister a notifier previously registered by 1529 * register_netdevice_notifier(). The notifier is unlinked into the 1530 * kernel structures and may then be reused. A negative errno code 1531 * is returned on a failure. 1532 * 1533 * After unregistering unregister and down device events are synthesized 1534 * for all devices on the device list to the removed notifier to remove 1535 * the need for special case cleanup code. 1536 */ 1537 1538 int unregister_netdevice_notifier(struct notifier_block *nb) 1539 { 1540 struct net_device *dev; 1541 struct net *net; 1542 int err; 1543 1544 rtnl_lock(); 1545 err = raw_notifier_chain_unregister(&netdev_chain, nb); 1546 if (err) 1547 goto unlock; 1548 1549 for_each_net(net) { 1550 for_each_netdev(net, dev) { 1551 if (dev->flags & IFF_UP) { 1552 call_netdevice_notifier(nb, NETDEV_GOING_DOWN, 1553 dev); 1554 call_netdevice_notifier(nb, NETDEV_DOWN, dev); 1555 } 1556 call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev); 1557 } 1558 } 1559 unlock: 1560 rtnl_unlock(); 1561 return err; 1562 } 1563 EXPORT_SYMBOL(unregister_netdevice_notifier); 1564 1565 /** 1566 * call_netdevice_notifiers_info - call all network notifier blocks 1567 * @val: value passed unmodified to notifier function 1568 * @dev: net_device pointer passed unmodified to notifier function 1569 * @info: notifier information data 1570 * 1571 * Call all network notifier blocks. Parameters and return value 1572 * are as for raw_notifier_call_chain(). 1573 */ 1574 1575 static int call_netdevice_notifiers_info(unsigned long val, 1576 struct net_device *dev, 1577 struct netdev_notifier_info *info) 1578 { 1579 ASSERT_RTNL(); 1580 netdev_notifier_info_init(info, dev); 1581 return raw_notifier_call_chain(&netdev_chain, val, info); 1582 } 1583 1584 /** 1585 * call_netdevice_notifiers - call all network notifier blocks 1586 * @val: value passed unmodified to notifier function 1587 * @dev: net_device pointer passed unmodified to notifier function 1588 * 1589 * Call all network notifier blocks. Parameters and return value 1590 * are as for raw_notifier_call_chain(). 1591 */ 1592 1593 int call_netdevice_notifiers(unsigned long val, struct net_device *dev) 1594 { 1595 struct netdev_notifier_info info; 1596 1597 return call_netdevice_notifiers_info(val, dev, &info); 1598 } 1599 EXPORT_SYMBOL(call_netdevice_notifiers); 1600 1601 static struct static_key netstamp_needed __read_mostly; 1602 #ifdef HAVE_JUMP_LABEL 1603 /* We are not allowed to call static_key_slow_dec() from irq context 1604 * If net_disable_timestamp() is called from irq context, defer the 1605 * static_key_slow_dec() calls. 1606 */ 1607 static atomic_t netstamp_needed_deferred; 1608 #endif 1609 1610 void net_enable_timestamp(void) 1611 { 1612 #ifdef HAVE_JUMP_LABEL 1613 int deferred = atomic_xchg(&netstamp_needed_deferred, 0); 1614 1615 if (deferred) { 1616 while (--deferred) 1617 static_key_slow_dec(&netstamp_needed); 1618 return; 1619 } 1620 #endif 1621 static_key_slow_inc(&netstamp_needed); 1622 } 1623 EXPORT_SYMBOL(net_enable_timestamp); 1624 1625 void net_disable_timestamp(void) 1626 { 1627 #ifdef HAVE_JUMP_LABEL 1628 if (in_interrupt()) { 1629 atomic_inc(&netstamp_needed_deferred); 1630 return; 1631 } 1632 #endif 1633 static_key_slow_dec(&netstamp_needed); 1634 } 1635 EXPORT_SYMBOL(net_disable_timestamp); 1636 1637 static inline void net_timestamp_set(struct sk_buff *skb) 1638 { 1639 skb->tstamp.tv64 = 0; 1640 if (static_key_false(&netstamp_needed)) 1641 __net_timestamp(skb); 1642 } 1643 1644 #define net_timestamp_check(COND, SKB) \ 1645 if (static_key_false(&netstamp_needed)) { \ 1646 if ((COND) && !(SKB)->tstamp.tv64) \ 1647 __net_timestamp(SKB); \ 1648 } \ 1649 1650 bool is_skb_forwardable(struct net_device *dev, struct sk_buff *skb) 1651 { 1652 unsigned int len; 1653 1654 if (!(dev->flags & IFF_UP)) 1655 return false; 1656 1657 len = dev->mtu + dev->hard_header_len + VLAN_HLEN; 1658 if (skb->len <= len) 1659 return true; 1660 1661 /* if TSO is enabled, we don't care about the length as the packet 1662 * could be forwarded without being segmented before 1663 */ 1664 if (skb_is_gso(skb)) 1665 return true; 1666 1667 return false; 1668 } 1669 EXPORT_SYMBOL_GPL(is_skb_forwardable); 1670 1671 int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb) 1672 { 1673 if (skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY) { 1674 if (skb_copy_ubufs(skb, GFP_ATOMIC)) { 1675 atomic_long_inc(&dev->rx_dropped); 1676 kfree_skb(skb); 1677 return NET_RX_DROP; 1678 } 1679 } 1680 1681 if (unlikely(!is_skb_forwardable(dev, skb))) { 1682 atomic_long_inc(&dev->rx_dropped); 1683 kfree_skb(skb); 1684 return NET_RX_DROP; 1685 } 1686 1687 skb_scrub_packet(skb, true); 1688 skb->protocol = eth_type_trans(skb, dev); 1689 1690 return 0; 1691 } 1692 EXPORT_SYMBOL_GPL(__dev_forward_skb); 1693 1694 /** 1695 * dev_forward_skb - loopback an skb to another netif 1696 * 1697 * @dev: destination network device 1698 * @skb: buffer to forward 1699 * 1700 * return values: 1701 * NET_RX_SUCCESS (no congestion) 1702 * NET_RX_DROP (packet was dropped, but freed) 1703 * 1704 * dev_forward_skb can be used for injecting an skb from the 1705 * start_xmit function of one device into the receive queue 1706 * of another device. 1707 * 1708 * The receiving device may be in another namespace, so 1709 * we have to clear all information in the skb that could 1710 * impact namespace isolation. 1711 */ 1712 int dev_forward_skb(struct net_device *dev, struct sk_buff *skb) 1713 { 1714 return __dev_forward_skb(dev, skb) ?: netif_rx_internal(skb); 1715 } 1716 EXPORT_SYMBOL_GPL(dev_forward_skb); 1717 1718 static inline int deliver_skb(struct sk_buff *skb, 1719 struct packet_type *pt_prev, 1720 struct net_device *orig_dev) 1721 { 1722 if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC))) 1723 return -ENOMEM; 1724 atomic_inc(&skb->users); 1725 return pt_prev->func(skb, skb->dev, pt_prev, orig_dev); 1726 } 1727 1728 static inline bool skb_loop_sk(struct packet_type *ptype, struct sk_buff *skb) 1729 { 1730 if (!ptype->af_packet_priv || !skb->sk) 1731 return false; 1732 1733 if (ptype->id_match) 1734 return ptype->id_match(ptype, skb->sk); 1735 else if ((struct sock *)ptype->af_packet_priv == skb->sk) 1736 return true; 1737 1738 return false; 1739 } 1740 1741 /* 1742 * Support routine. Sends outgoing frames to any network 1743 * taps currently in use. 1744 */ 1745 1746 static void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev) 1747 { 1748 struct packet_type *ptype; 1749 struct sk_buff *skb2 = NULL; 1750 struct packet_type *pt_prev = NULL; 1751 1752 rcu_read_lock(); 1753 list_for_each_entry_rcu(ptype, &ptype_all, list) { 1754 /* Never send packets back to the socket 1755 * they originated from - MvS (miquels@drinkel.ow.org) 1756 */ 1757 if ((ptype->dev == dev || !ptype->dev) && 1758 (!skb_loop_sk(ptype, skb))) { 1759 if (pt_prev) { 1760 deliver_skb(skb2, pt_prev, skb->dev); 1761 pt_prev = ptype; 1762 continue; 1763 } 1764 1765 skb2 = skb_clone(skb, GFP_ATOMIC); 1766 if (!skb2) 1767 break; 1768 1769 net_timestamp_set(skb2); 1770 1771 /* skb->nh should be correctly 1772 set by sender, so that the second statement is 1773 just protection against buggy protocols. 1774 */ 1775 skb_reset_mac_header(skb2); 1776 1777 if (skb_network_header(skb2) < skb2->data || 1778 skb_network_header(skb2) > skb_tail_pointer(skb2)) { 1779 net_crit_ratelimited("protocol %04x is buggy, dev %s\n", 1780 ntohs(skb2->protocol), 1781 dev->name); 1782 skb_reset_network_header(skb2); 1783 } 1784 1785 skb2->transport_header = skb2->network_header; 1786 skb2->pkt_type = PACKET_OUTGOING; 1787 pt_prev = ptype; 1788 } 1789 } 1790 if (pt_prev) 1791 pt_prev->func(skb2, skb->dev, pt_prev, skb->dev); 1792 rcu_read_unlock(); 1793 } 1794 1795 /** 1796 * netif_setup_tc - Handle tc mappings on real_num_tx_queues change 1797 * @dev: Network device 1798 * @txq: number of queues available 1799 * 1800 * If real_num_tx_queues is changed the tc mappings may no longer be 1801 * valid. To resolve this verify the tc mapping remains valid and if 1802 * not NULL the mapping. With no priorities mapping to this 1803 * offset/count pair it will no longer be used. In the worst case TC0 1804 * is invalid nothing can be done so disable priority mappings. If is 1805 * expected that drivers will fix this mapping if they can before 1806 * calling netif_set_real_num_tx_queues. 1807 */ 1808 static void netif_setup_tc(struct net_device *dev, unsigned int txq) 1809 { 1810 int i; 1811 struct netdev_tc_txq *tc = &dev->tc_to_txq[0]; 1812 1813 /* If TC0 is invalidated disable TC mapping */ 1814 if (tc->offset + tc->count > txq) { 1815 pr_warn("Number of in use tx queues changed invalidating tc mappings. Priority traffic classification disabled!\n"); 1816 dev->num_tc = 0; 1817 return; 1818 } 1819 1820 /* Invalidated prio to tc mappings set to TC0 */ 1821 for (i = 1; i < TC_BITMASK + 1; i++) { 1822 int q = netdev_get_prio_tc_map(dev, i); 1823 1824 tc = &dev->tc_to_txq[q]; 1825 if (tc->offset + tc->count > txq) { 1826 pr_warn("Number of in use tx queues changed. Priority %i to tc mapping %i is no longer valid. Setting map to 0\n", 1827 i, q); 1828 netdev_set_prio_tc_map(dev, i, 0); 1829 } 1830 } 1831 } 1832 1833 #ifdef CONFIG_XPS 1834 static DEFINE_MUTEX(xps_map_mutex); 1835 #define xmap_dereference(P) \ 1836 rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex)) 1837 1838 static struct xps_map *remove_xps_queue(struct xps_dev_maps *dev_maps, 1839 int cpu, u16 index) 1840 { 1841 struct xps_map *map = NULL; 1842 int pos; 1843 1844 if (dev_maps) 1845 map = xmap_dereference(dev_maps->cpu_map[cpu]); 1846 1847 for (pos = 0; map && pos < map->len; pos++) { 1848 if (map->queues[pos] == index) { 1849 if (map->len > 1) { 1850 map->queues[pos] = map->queues[--map->len]; 1851 } else { 1852 RCU_INIT_POINTER(dev_maps->cpu_map[cpu], NULL); 1853 kfree_rcu(map, rcu); 1854 map = NULL; 1855 } 1856 break; 1857 } 1858 } 1859 1860 return map; 1861 } 1862 1863 static void netif_reset_xps_queues_gt(struct net_device *dev, u16 index) 1864 { 1865 struct xps_dev_maps *dev_maps; 1866 int cpu, i; 1867 bool active = false; 1868 1869 mutex_lock(&xps_map_mutex); 1870 dev_maps = xmap_dereference(dev->xps_maps); 1871 1872 if (!dev_maps) 1873 goto out_no_maps; 1874 1875 for_each_possible_cpu(cpu) { 1876 for (i = index; i < dev->num_tx_queues; i++) { 1877 if (!remove_xps_queue(dev_maps, cpu, i)) 1878 break; 1879 } 1880 if (i == dev->num_tx_queues) 1881 active = true; 1882 } 1883 1884 if (!active) { 1885 RCU_INIT_POINTER(dev->xps_maps, NULL); 1886 kfree_rcu(dev_maps, rcu); 1887 } 1888 1889 for (i = index; i < dev->num_tx_queues; i++) 1890 netdev_queue_numa_node_write(netdev_get_tx_queue(dev, i), 1891 NUMA_NO_NODE); 1892 1893 out_no_maps: 1894 mutex_unlock(&xps_map_mutex); 1895 } 1896 1897 static struct xps_map *expand_xps_map(struct xps_map *map, 1898 int cpu, u16 index) 1899 { 1900 struct xps_map *new_map; 1901 int alloc_len = XPS_MIN_MAP_ALLOC; 1902 int i, pos; 1903 1904 for (pos = 0; map && pos < map->len; pos++) { 1905 if (map->queues[pos] != index) 1906 continue; 1907 return map; 1908 } 1909 1910 /* Need to add queue to this CPU's existing map */ 1911 if (map) { 1912 if (pos < map->alloc_len) 1913 return map; 1914 1915 alloc_len = map->alloc_len * 2; 1916 } 1917 1918 /* Need to allocate new map to store queue on this CPU's map */ 1919 new_map = kzalloc_node(XPS_MAP_SIZE(alloc_len), GFP_KERNEL, 1920 cpu_to_node(cpu)); 1921 if (!new_map) 1922 return NULL; 1923 1924 for (i = 0; i < pos; i++) 1925 new_map->queues[i] = map->queues[i]; 1926 new_map->alloc_len = alloc_len; 1927 new_map->len = pos; 1928 1929 return new_map; 1930 } 1931 1932 int netif_set_xps_queue(struct net_device *dev, const struct cpumask *mask, 1933 u16 index) 1934 { 1935 struct xps_dev_maps *dev_maps, *new_dev_maps = NULL; 1936 struct xps_map *map, *new_map; 1937 int maps_sz = max_t(unsigned int, XPS_DEV_MAPS_SIZE, L1_CACHE_BYTES); 1938 int cpu, numa_node_id = -2; 1939 bool active = false; 1940 1941 mutex_lock(&xps_map_mutex); 1942 1943 dev_maps = xmap_dereference(dev->xps_maps); 1944 1945 /* allocate memory for queue storage */ 1946 for_each_online_cpu(cpu) { 1947 if (!cpumask_test_cpu(cpu, mask)) 1948 continue; 1949 1950 if (!new_dev_maps) 1951 new_dev_maps = kzalloc(maps_sz, GFP_KERNEL); 1952 if (!new_dev_maps) { 1953 mutex_unlock(&xps_map_mutex); 1954 return -ENOMEM; 1955 } 1956 1957 map = dev_maps ? xmap_dereference(dev_maps->cpu_map[cpu]) : 1958 NULL; 1959 1960 map = expand_xps_map(map, cpu, index); 1961 if (!map) 1962 goto error; 1963 1964 RCU_INIT_POINTER(new_dev_maps->cpu_map[cpu], map); 1965 } 1966 1967 if (!new_dev_maps) 1968 goto out_no_new_maps; 1969 1970 for_each_possible_cpu(cpu) { 1971 if (cpumask_test_cpu(cpu, mask) && cpu_online(cpu)) { 1972 /* add queue to CPU maps */ 1973 int pos = 0; 1974 1975 map = xmap_dereference(new_dev_maps->cpu_map[cpu]); 1976 while ((pos < map->len) && (map->queues[pos] != index)) 1977 pos++; 1978 1979 if (pos == map->len) 1980 map->queues[map->len++] = index; 1981 #ifdef CONFIG_NUMA 1982 if (numa_node_id == -2) 1983 numa_node_id = cpu_to_node(cpu); 1984 else if (numa_node_id != cpu_to_node(cpu)) 1985 numa_node_id = -1; 1986 #endif 1987 } else if (dev_maps) { 1988 /* fill in the new device map from the old device map */ 1989 map = xmap_dereference(dev_maps->cpu_map[cpu]); 1990 RCU_INIT_POINTER(new_dev_maps->cpu_map[cpu], map); 1991 } 1992 1993 } 1994 1995 rcu_assign_pointer(dev->xps_maps, new_dev_maps); 1996 1997 /* Cleanup old maps */ 1998 if (dev_maps) { 1999 for_each_possible_cpu(cpu) { 2000 new_map = xmap_dereference(new_dev_maps->cpu_map[cpu]); 2001 map = xmap_dereference(dev_maps->cpu_map[cpu]); 2002 if (map && map != new_map) 2003 kfree_rcu(map, rcu); 2004 } 2005 2006 kfree_rcu(dev_maps, rcu); 2007 } 2008 2009 dev_maps = new_dev_maps; 2010 active = true; 2011 2012 out_no_new_maps: 2013 /* update Tx queue numa node */ 2014 netdev_queue_numa_node_write(netdev_get_tx_queue(dev, index), 2015 (numa_node_id >= 0) ? numa_node_id : 2016 NUMA_NO_NODE); 2017 2018 if (!dev_maps) 2019 goto out_no_maps; 2020 2021 /* removes queue from unused CPUs */ 2022 for_each_possible_cpu(cpu) { 2023 if (cpumask_test_cpu(cpu, mask) && cpu_online(cpu)) 2024 continue; 2025 2026 if (remove_xps_queue(dev_maps, cpu, index)) 2027 active = true; 2028 } 2029 2030 /* free map if not active */ 2031 if (!active) { 2032 RCU_INIT_POINTER(dev->xps_maps, NULL); 2033 kfree_rcu(dev_maps, rcu); 2034 } 2035 2036 out_no_maps: 2037 mutex_unlock(&xps_map_mutex); 2038 2039 return 0; 2040 error: 2041 /* remove any maps that we added */ 2042 for_each_possible_cpu(cpu) { 2043 new_map = xmap_dereference(new_dev_maps->cpu_map[cpu]); 2044 map = dev_maps ? xmap_dereference(dev_maps->cpu_map[cpu]) : 2045 NULL; 2046 if (new_map && new_map != map) 2047 kfree(new_map); 2048 } 2049 2050 mutex_unlock(&xps_map_mutex); 2051 2052 kfree(new_dev_maps); 2053 return -ENOMEM; 2054 } 2055 EXPORT_SYMBOL(netif_set_xps_queue); 2056 2057 #endif 2058 /* 2059 * Routine to help set real_num_tx_queues. To avoid skbs mapped to queues 2060 * greater then real_num_tx_queues stale skbs on the qdisc must be flushed. 2061 */ 2062 int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq) 2063 { 2064 int rc; 2065 2066 if (txq < 1 || txq > dev->num_tx_queues) 2067 return -EINVAL; 2068 2069 if (dev->reg_state == NETREG_REGISTERED || 2070 dev->reg_state == NETREG_UNREGISTERING) { 2071 ASSERT_RTNL(); 2072 2073 rc = netdev_queue_update_kobjects(dev, dev->real_num_tx_queues, 2074 txq); 2075 if (rc) 2076 return rc; 2077 2078 if (dev->num_tc) 2079 netif_setup_tc(dev, txq); 2080 2081 if (txq < dev->real_num_tx_queues) { 2082 qdisc_reset_all_tx_gt(dev, txq); 2083 #ifdef CONFIG_XPS 2084 netif_reset_xps_queues_gt(dev, txq); 2085 #endif 2086 } 2087 } 2088 2089 dev->real_num_tx_queues = txq; 2090 return 0; 2091 } 2092 EXPORT_SYMBOL(netif_set_real_num_tx_queues); 2093 2094 #ifdef CONFIG_SYSFS 2095 /** 2096 * netif_set_real_num_rx_queues - set actual number of RX queues used 2097 * @dev: Network device 2098 * @rxq: Actual number of RX queues 2099 * 2100 * This must be called either with the rtnl_lock held or before 2101 * registration of the net device. Returns 0 on success, or a 2102 * negative error code. If called before registration, it always 2103 * succeeds. 2104 */ 2105 int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq) 2106 { 2107 int rc; 2108 2109 if (rxq < 1 || rxq > dev->num_rx_queues) 2110 return -EINVAL; 2111 2112 if (dev->reg_state == NETREG_REGISTERED) { 2113 ASSERT_RTNL(); 2114 2115 rc = net_rx_queue_update_kobjects(dev, dev->real_num_rx_queues, 2116 rxq); 2117 if (rc) 2118 return rc; 2119 } 2120 2121 dev->real_num_rx_queues = rxq; 2122 return 0; 2123 } 2124 EXPORT_SYMBOL(netif_set_real_num_rx_queues); 2125 #endif 2126 2127 /** 2128 * netif_get_num_default_rss_queues - default number of RSS queues 2129 * 2130 * This routine should set an upper limit on the number of RSS queues 2131 * used by default by multiqueue devices. 2132 */ 2133 int netif_get_num_default_rss_queues(void) 2134 { 2135 return min_t(int, DEFAULT_MAX_NUM_RSS_QUEUES, num_online_cpus()); 2136 } 2137 EXPORT_SYMBOL(netif_get_num_default_rss_queues); 2138 2139 static inline void __netif_reschedule(struct Qdisc *q) 2140 { 2141 struct softnet_data *sd; 2142 unsigned long flags; 2143 2144 local_irq_save(flags); 2145 sd = &__get_cpu_var(softnet_data); 2146 q->next_sched = NULL; 2147 *sd->output_queue_tailp = q; 2148 sd->output_queue_tailp = &q->next_sched; 2149 raise_softirq_irqoff(NET_TX_SOFTIRQ); 2150 local_irq_restore(flags); 2151 } 2152 2153 void __netif_schedule(struct Qdisc *q) 2154 { 2155 if (!test_and_set_bit(__QDISC_STATE_SCHED, &q->state)) 2156 __netif_reschedule(q); 2157 } 2158 EXPORT_SYMBOL(__netif_schedule); 2159 2160 struct dev_kfree_skb_cb { 2161 enum skb_free_reason reason; 2162 }; 2163 2164 static struct dev_kfree_skb_cb *get_kfree_skb_cb(const struct sk_buff *skb) 2165 { 2166 return (struct dev_kfree_skb_cb *)skb->cb; 2167 } 2168 2169 void __dev_kfree_skb_irq(struct sk_buff *skb, enum skb_free_reason reason) 2170 { 2171 unsigned long flags; 2172 2173 if (likely(atomic_read(&skb->users) == 1)) { 2174 smp_rmb(); 2175 atomic_set(&skb->users, 0); 2176 } else if (likely(!atomic_dec_and_test(&skb->users))) { 2177 return; 2178 } 2179 get_kfree_skb_cb(skb)->reason = reason; 2180 local_irq_save(flags); 2181 skb->next = __this_cpu_read(softnet_data.completion_queue); 2182 __this_cpu_write(softnet_data.completion_queue, skb); 2183 raise_softirq_irqoff(NET_TX_SOFTIRQ); 2184 local_irq_restore(flags); 2185 } 2186 EXPORT_SYMBOL(__dev_kfree_skb_irq); 2187 2188 void __dev_kfree_skb_any(struct sk_buff *skb, enum skb_free_reason reason) 2189 { 2190 if (in_irq() || irqs_disabled()) 2191 __dev_kfree_skb_irq(skb, reason); 2192 else 2193 dev_kfree_skb(skb); 2194 } 2195 EXPORT_SYMBOL(__dev_kfree_skb_any); 2196 2197 2198 /** 2199 * netif_device_detach - mark device as removed 2200 * @dev: network device 2201 * 2202 * Mark device as removed from system and therefore no longer available. 2203 */ 2204 void netif_device_detach(struct net_device *dev) 2205 { 2206 if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) && 2207 netif_running(dev)) { 2208 netif_tx_stop_all_queues(dev); 2209 } 2210 } 2211 EXPORT_SYMBOL(netif_device_detach); 2212 2213 /** 2214 * netif_device_attach - mark device as attached 2215 * @dev: network device 2216 * 2217 * Mark device as attached from system and restart if needed. 2218 */ 2219 void netif_device_attach(struct net_device *dev) 2220 { 2221 if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) && 2222 netif_running(dev)) { 2223 netif_tx_wake_all_queues(dev); 2224 __netdev_watchdog_up(dev); 2225 } 2226 } 2227 EXPORT_SYMBOL(netif_device_attach); 2228 2229 static void skb_warn_bad_offload(const struct sk_buff *skb) 2230 { 2231 static const netdev_features_t null_features = 0; 2232 struct net_device *dev = skb->dev; 2233 const char *driver = ""; 2234 2235 if (!net_ratelimit()) 2236 return; 2237 2238 if (dev && dev->dev.parent) 2239 driver = dev_driver_string(dev->dev.parent); 2240 2241 WARN(1, "%s: caps=(%pNF, %pNF) len=%d data_len=%d gso_size=%d " 2242 "gso_type=%d ip_summed=%d\n", 2243 driver, dev ? &dev->features : &null_features, 2244 skb->sk ? &skb->sk->sk_route_caps : &null_features, 2245 skb->len, skb->data_len, skb_shinfo(skb)->gso_size, 2246 skb_shinfo(skb)->gso_type, skb->ip_summed); 2247 } 2248 2249 /* 2250 * Invalidate hardware checksum when packet is to be mangled, and 2251 * complete checksum manually on outgoing path. 2252 */ 2253 int skb_checksum_help(struct sk_buff *skb) 2254 { 2255 __wsum csum; 2256 int ret = 0, offset; 2257 2258 if (skb->ip_summed == CHECKSUM_COMPLETE) 2259 goto out_set_summed; 2260 2261 if (unlikely(skb_shinfo(skb)->gso_size)) { 2262 skb_warn_bad_offload(skb); 2263 return -EINVAL; 2264 } 2265 2266 /* Before computing a checksum, we should make sure no frag could 2267 * be modified by an external entity : checksum could be wrong. 2268 */ 2269 if (skb_has_shared_frag(skb)) { 2270 ret = __skb_linearize(skb); 2271 if (ret) 2272 goto out; 2273 } 2274 2275 offset = skb_checksum_start_offset(skb); 2276 BUG_ON(offset >= skb_headlen(skb)); 2277 csum = skb_checksum(skb, offset, skb->len - offset, 0); 2278 2279 offset += skb->csum_offset; 2280 BUG_ON(offset + sizeof(__sum16) > skb_headlen(skb)); 2281 2282 if (skb_cloned(skb) && 2283 !skb_clone_writable(skb, offset + sizeof(__sum16))) { 2284 ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC); 2285 if (ret) 2286 goto out; 2287 } 2288 2289 *(__sum16 *)(skb->data + offset) = csum_fold(csum); 2290 out_set_summed: 2291 skb->ip_summed = CHECKSUM_NONE; 2292 out: 2293 return ret; 2294 } 2295 EXPORT_SYMBOL(skb_checksum_help); 2296 2297 __be16 skb_network_protocol(struct sk_buff *skb, int *depth) 2298 { 2299 unsigned int vlan_depth = skb->mac_len; 2300 __be16 type = skb->protocol; 2301 2302 /* Tunnel gso handlers can set protocol to ethernet. */ 2303 if (type == htons(ETH_P_TEB)) { 2304 struct ethhdr *eth; 2305 2306 if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr)))) 2307 return 0; 2308 2309 eth = (struct ethhdr *)skb_mac_header(skb); 2310 type = eth->h_proto; 2311 } 2312 2313 /* if skb->protocol is 802.1Q/AD then the header should already be 2314 * present at mac_len - VLAN_HLEN (if mac_len > 0), or at 2315 * ETH_HLEN otherwise 2316 */ 2317 if (type == htons(ETH_P_8021Q) || type == htons(ETH_P_8021AD)) { 2318 if (vlan_depth) { 2319 if (unlikely(WARN_ON(vlan_depth < VLAN_HLEN))) 2320 return 0; 2321 vlan_depth -= VLAN_HLEN; 2322 } else { 2323 vlan_depth = ETH_HLEN; 2324 } 2325 do { 2326 struct vlan_hdr *vh; 2327 2328 if (unlikely(!pskb_may_pull(skb, 2329 vlan_depth + VLAN_HLEN))) 2330 return 0; 2331 2332 vh = (struct vlan_hdr *)(skb->data + vlan_depth); 2333 type = vh->h_vlan_encapsulated_proto; 2334 vlan_depth += VLAN_HLEN; 2335 } while (type == htons(ETH_P_8021Q) || 2336 type == htons(ETH_P_8021AD)); 2337 } 2338 2339 *depth = vlan_depth; 2340 2341 return type; 2342 } 2343 2344 /** 2345 * skb_mac_gso_segment - mac layer segmentation handler. 2346 * @skb: buffer to segment 2347 * @features: features for the output path (see dev->features) 2348 */ 2349 struct sk_buff *skb_mac_gso_segment(struct sk_buff *skb, 2350 netdev_features_t features) 2351 { 2352 struct sk_buff *segs = ERR_PTR(-EPROTONOSUPPORT); 2353 struct packet_offload *ptype; 2354 int vlan_depth = skb->mac_len; 2355 __be16 type = skb_network_protocol(skb, &vlan_depth); 2356 2357 if (unlikely(!type)) 2358 return ERR_PTR(-EINVAL); 2359 2360 __skb_pull(skb, vlan_depth); 2361 2362 rcu_read_lock(); 2363 list_for_each_entry_rcu(ptype, &offload_base, list) { 2364 if (ptype->type == type && ptype->callbacks.gso_segment) { 2365 if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) { 2366 int err; 2367 2368 err = ptype->callbacks.gso_send_check(skb); 2369 segs = ERR_PTR(err); 2370 if (err || skb_gso_ok(skb, features)) 2371 break; 2372 __skb_push(skb, (skb->data - 2373 skb_network_header(skb))); 2374 } 2375 segs = ptype->callbacks.gso_segment(skb, features); 2376 break; 2377 } 2378 } 2379 rcu_read_unlock(); 2380 2381 __skb_push(skb, skb->data - skb_mac_header(skb)); 2382 2383 return segs; 2384 } 2385 EXPORT_SYMBOL(skb_mac_gso_segment); 2386 2387 2388 /* openvswitch calls this on rx path, so we need a different check. 2389 */ 2390 static inline bool skb_needs_check(struct sk_buff *skb, bool tx_path) 2391 { 2392 if (tx_path) 2393 return skb->ip_summed != CHECKSUM_PARTIAL; 2394 else 2395 return skb->ip_summed == CHECKSUM_NONE; 2396 } 2397 2398 /** 2399 * __skb_gso_segment - Perform segmentation on skb. 2400 * @skb: buffer to segment 2401 * @features: features for the output path (see dev->features) 2402 * @tx_path: whether it is called in TX path 2403 * 2404 * This function segments the given skb and returns a list of segments. 2405 * 2406 * It may return NULL if the skb requires no segmentation. This is 2407 * only possible when GSO is used for verifying header integrity. 2408 */ 2409 struct sk_buff *__skb_gso_segment(struct sk_buff *skb, 2410 netdev_features_t features, bool tx_path) 2411 { 2412 if (unlikely(skb_needs_check(skb, tx_path))) { 2413 int err; 2414 2415 skb_warn_bad_offload(skb); 2416 2417 if (skb_header_cloned(skb) && 2418 (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC))) 2419 return ERR_PTR(err); 2420 } 2421 2422 SKB_GSO_CB(skb)->mac_offset = skb_headroom(skb); 2423 SKB_GSO_CB(skb)->encap_level = 0; 2424 2425 skb_reset_mac_header(skb); 2426 skb_reset_mac_len(skb); 2427 2428 return skb_mac_gso_segment(skb, features); 2429 } 2430 EXPORT_SYMBOL(__skb_gso_segment); 2431 2432 /* Take action when hardware reception checksum errors are detected. */ 2433 #ifdef CONFIG_BUG 2434 void netdev_rx_csum_fault(struct net_device *dev) 2435 { 2436 if (net_ratelimit()) { 2437 pr_err("%s: hw csum failure\n", dev ? dev->name : "<unknown>"); 2438 dump_stack(); 2439 } 2440 } 2441 EXPORT_SYMBOL(netdev_rx_csum_fault); 2442 #endif 2443 2444 /* Actually, we should eliminate this check as soon as we know, that: 2445 * 1. IOMMU is present and allows to map all the memory. 2446 * 2. No high memory really exists on this machine. 2447 */ 2448 2449 static int illegal_highdma(struct net_device *dev, struct sk_buff *skb) 2450 { 2451 #ifdef CONFIG_HIGHMEM 2452 int i; 2453 if (!(dev->features & NETIF_F_HIGHDMA)) { 2454 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { 2455 skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; 2456 if (PageHighMem(skb_frag_page(frag))) 2457 return 1; 2458 } 2459 } 2460 2461 if (PCI_DMA_BUS_IS_PHYS) { 2462 struct device *pdev = dev->dev.parent; 2463 2464 if (!pdev) 2465 return 0; 2466 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { 2467 skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; 2468 dma_addr_t addr = page_to_phys(skb_frag_page(frag)); 2469 if (!pdev->dma_mask || addr + PAGE_SIZE - 1 > *pdev->dma_mask) 2470 return 1; 2471 } 2472 } 2473 #endif 2474 return 0; 2475 } 2476 2477 struct dev_gso_cb { 2478 void (*destructor)(struct sk_buff *skb); 2479 }; 2480 2481 #define DEV_GSO_CB(skb) ((struct dev_gso_cb *)(skb)->cb) 2482 2483 static void dev_gso_skb_destructor(struct sk_buff *skb) 2484 { 2485 struct dev_gso_cb *cb; 2486 2487 kfree_skb_list(skb->next); 2488 skb->next = NULL; 2489 2490 cb = DEV_GSO_CB(skb); 2491 if (cb->destructor) 2492 cb->destructor(skb); 2493 } 2494 2495 /** 2496 * dev_gso_segment - Perform emulated hardware segmentation on skb. 2497 * @skb: buffer to segment 2498 * @features: device features as applicable to this skb 2499 * 2500 * This function segments the given skb and stores the list of segments 2501 * in skb->next. 2502 */ 2503 static int dev_gso_segment(struct sk_buff *skb, netdev_features_t features) 2504 { 2505 struct sk_buff *segs; 2506 2507 segs = skb_gso_segment(skb, features); 2508 2509 /* Verifying header integrity only. */ 2510 if (!segs) 2511 return 0; 2512 2513 if (IS_ERR(segs)) 2514 return PTR_ERR(segs); 2515 2516 skb->next = segs; 2517 DEV_GSO_CB(skb)->destructor = skb->destructor; 2518 skb->destructor = dev_gso_skb_destructor; 2519 2520 return 0; 2521 } 2522 2523 /* If MPLS offload request, verify we are testing hardware MPLS features 2524 * instead of standard features for the netdev. 2525 */ 2526 #ifdef CONFIG_NET_MPLS_GSO 2527 static netdev_features_t net_mpls_features(struct sk_buff *skb, 2528 netdev_features_t features, 2529 __be16 type) 2530 { 2531 if (type == htons(ETH_P_MPLS_UC) || type == htons(ETH_P_MPLS_MC)) 2532 features &= skb->dev->mpls_features; 2533 2534 return features; 2535 } 2536 #else 2537 static netdev_features_t net_mpls_features(struct sk_buff *skb, 2538 netdev_features_t features, 2539 __be16 type) 2540 { 2541 return features; 2542 } 2543 #endif 2544 2545 static netdev_features_t harmonize_features(struct sk_buff *skb, 2546 netdev_features_t features) 2547 { 2548 int tmp; 2549 __be16 type; 2550 2551 type = skb_network_protocol(skb, &tmp); 2552 features = net_mpls_features(skb, features, type); 2553 2554 if (skb->ip_summed != CHECKSUM_NONE && 2555 !can_checksum_protocol(features, type)) { 2556 features &= ~NETIF_F_ALL_CSUM; 2557 } else if (illegal_highdma(skb->dev, skb)) { 2558 features &= ~NETIF_F_SG; 2559 } 2560 2561 return features; 2562 } 2563 2564 netdev_features_t netif_skb_features(struct sk_buff *skb) 2565 { 2566 __be16 protocol = skb->protocol; 2567 netdev_features_t features = skb->dev->features; 2568 2569 if (skb_shinfo(skb)->gso_segs > skb->dev->gso_max_segs) 2570 features &= ~NETIF_F_GSO_MASK; 2571 2572 if (protocol == htons(ETH_P_8021Q) || protocol == htons(ETH_P_8021AD)) { 2573 struct vlan_ethhdr *veh = (struct vlan_ethhdr *)skb->data; 2574 protocol = veh->h_vlan_encapsulated_proto; 2575 } else if (!vlan_tx_tag_present(skb)) { 2576 return harmonize_features(skb, features); 2577 } 2578 2579 features &= (skb->dev->vlan_features | NETIF_F_HW_VLAN_CTAG_TX | 2580 NETIF_F_HW_VLAN_STAG_TX); 2581 2582 if (protocol == htons(ETH_P_8021Q) || protocol == htons(ETH_P_8021AD)) 2583 features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST | 2584 NETIF_F_GEN_CSUM | NETIF_F_HW_VLAN_CTAG_TX | 2585 NETIF_F_HW_VLAN_STAG_TX; 2586 2587 return harmonize_features(skb, features); 2588 } 2589 EXPORT_SYMBOL(netif_skb_features); 2590 2591 int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev, 2592 struct netdev_queue *txq) 2593 { 2594 const struct net_device_ops *ops = dev->netdev_ops; 2595 int rc = NETDEV_TX_OK; 2596 unsigned int skb_len; 2597 2598 if (likely(!skb->next)) { 2599 netdev_features_t features; 2600 2601 /* 2602 * If device doesn't need skb->dst, release it right now while 2603 * its hot in this cpu cache 2604 */ 2605 if (dev->priv_flags & IFF_XMIT_DST_RELEASE) 2606 skb_dst_drop(skb); 2607 2608 features = netif_skb_features(skb); 2609 2610 if (vlan_tx_tag_present(skb) && 2611 !vlan_hw_offload_capable(features, skb->vlan_proto)) { 2612 skb = __vlan_put_tag(skb, skb->vlan_proto, 2613 vlan_tx_tag_get(skb)); 2614 if (unlikely(!skb)) 2615 goto out; 2616 2617 skb->vlan_tci = 0; 2618 } 2619 2620 /* If encapsulation offload request, verify we are testing 2621 * hardware encapsulation features instead of standard 2622 * features for the netdev 2623 */ 2624 if (skb->encapsulation) 2625 features &= dev->hw_enc_features; 2626 2627 if (netif_needs_gso(skb, features)) { 2628 if (unlikely(dev_gso_segment(skb, features))) 2629 goto out_kfree_skb; 2630 if (skb->next) 2631 goto gso; 2632 } else { 2633 if (skb_needs_linearize(skb, features) && 2634 __skb_linearize(skb)) 2635 goto out_kfree_skb; 2636 2637 /* If packet is not checksummed and device does not 2638 * support checksumming for this protocol, complete 2639 * checksumming here. 2640 */ 2641 if (skb->ip_summed == CHECKSUM_PARTIAL) { 2642 if (skb->encapsulation) 2643 skb_set_inner_transport_header(skb, 2644 skb_checksum_start_offset(skb)); 2645 else 2646 skb_set_transport_header(skb, 2647 skb_checksum_start_offset(skb)); 2648 if (!(features & NETIF_F_ALL_CSUM) && 2649 skb_checksum_help(skb)) 2650 goto out_kfree_skb; 2651 } 2652 } 2653 2654 if (!list_empty(&ptype_all)) 2655 dev_queue_xmit_nit(skb, dev); 2656 2657 skb_len = skb->len; 2658 trace_net_dev_start_xmit(skb, dev); 2659 rc = ops->ndo_start_xmit(skb, dev); 2660 trace_net_dev_xmit(skb, rc, dev, skb_len); 2661 if (rc == NETDEV_TX_OK) 2662 txq_trans_update(txq); 2663 return rc; 2664 } 2665 2666 gso: 2667 do { 2668 struct sk_buff *nskb = skb->next; 2669 2670 skb->next = nskb->next; 2671 nskb->next = NULL; 2672 2673 if (!list_empty(&ptype_all)) 2674 dev_queue_xmit_nit(nskb, dev); 2675 2676 skb_len = nskb->len; 2677 trace_net_dev_start_xmit(nskb, dev); 2678 rc = ops->ndo_start_xmit(nskb, dev); 2679 trace_net_dev_xmit(nskb, rc, dev, skb_len); 2680 if (unlikely(rc != NETDEV_TX_OK)) { 2681 if (rc & ~NETDEV_TX_MASK) 2682 goto out_kfree_gso_skb; 2683 nskb->next = skb->next; 2684 skb->next = nskb; 2685 return rc; 2686 } 2687 txq_trans_update(txq); 2688 if (unlikely(netif_xmit_stopped(txq) && skb->next)) 2689 return NETDEV_TX_BUSY; 2690 } while (skb->next); 2691 2692 out_kfree_gso_skb: 2693 if (likely(skb->next == NULL)) { 2694 skb->destructor = DEV_GSO_CB(skb)->destructor; 2695 consume_skb(skb); 2696 return rc; 2697 } 2698 out_kfree_skb: 2699 kfree_skb(skb); 2700 out: 2701 return rc; 2702 } 2703 EXPORT_SYMBOL_GPL(dev_hard_start_xmit); 2704 2705 static void qdisc_pkt_len_init(struct sk_buff *skb) 2706 { 2707 const struct skb_shared_info *shinfo = skb_shinfo(skb); 2708 2709 qdisc_skb_cb(skb)->pkt_len = skb->len; 2710 2711 /* To get more precise estimation of bytes sent on wire, 2712 * we add to pkt_len the headers size of all segments 2713 */ 2714 if (shinfo->gso_size) { 2715 unsigned int hdr_len; 2716 u16 gso_segs = shinfo->gso_segs; 2717 2718 /* mac layer + network layer */ 2719 hdr_len = skb_transport_header(skb) - skb_mac_header(skb); 2720 2721 /* + transport layer */ 2722 if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))) 2723 hdr_len += tcp_hdrlen(skb); 2724 else 2725 hdr_len += sizeof(struct udphdr); 2726 2727 if (shinfo->gso_type & SKB_GSO_DODGY) 2728 gso_segs = DIV_ROUND_UP(skb->len - hdr_len, 2729 shinfo->gso_size); 2730 2731 qdisc_skb_cb(skb)->pkt_len += (gso_segs - 1) * hdr_len; 2732 } 2733 } 2734 2735 static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q, 2736 struct net_device *dev, 2737 struct netdev_queue *txq) 2738 { 2739 spinlock_t *root_lock = qdisc_lock(q); 2740 bool contended; 2741 int rc; 2742 2743 qdisc_pkt_len_init(skb); 2744 qdisc_calculate_pkt_len(skb, q); 2745 /* 2746 * Heuristic to force contended enqueues to serialize on a 2747 * separate lock before trying to get qdisc main lock. 2748 * This permits __QDISC_STATE_RUNNING owner to get the lock more often 2749 * and dequeue packets faster. 2750 */ 2751 contended = qdisc_is_running(q); 2752 if (unlikely(contended)) 2753 spin_lock(&q->busylock); 2754 2755 spin_lock(root_lock); 2756 if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) { 2757 kfree_skb(skb); 2758 rc = NET_XMIT_DROP; 2759 } else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) && 2760 qdisc_run_begin(q)) { 2761 /* 2762 * This is a work-conserving queue; there are no old skbs 2763 * waiting to be sent out; and the qdisc is not running - 2764 * xmit the skb directly. 2765 */ 2766 if (!(dev->priv_flags & IFF_XMIT_DST_RELEASE)) 2767 skb_dst_force(skb); 2768 2769 qdisc_bstats_update(q, skb); 2770 2771 if (sch_direct_xmit(skb, q, dev, txq, root_lock)) { 2772 if (unlikely(contended)) { 2773 spin_unlock(&q->busylock); 2774 contended = false; 2775 } 2776 __qdisc_run(q); 2777 } else 2778 qdisc_run_end(q); 2779 2780 rc = NET_XMIT_SUCCESS; 2781 } else { 2782 skb_dst_force(skb); 2783 rc = q->enqueue(skb, q) & NET_XMIT_MASK; 2784 if (qdisc_run_begin(q)) { 2785 if (unlikely(contended)) { 2786 spin_unlock(&q->busylock); 2787 contended = false; 2788 } 2789 __qdisc_run(q); 2790 } 2791 } 2792 spin_unlock(root_lock); 2793 if (unlikely(contended)) 2794 spin_unlock(&q->busylock); 2795 return rc; 2796 } 2797 2798 #if IS_ENABLED(CONFIG_CGROUP_NET_PRIO) 2799 static void skb_update_prio(struct sk_buff *skb) 2800 { 2801 struct netprio_map *map = rcu_dereference_bh(skb->dev->priomap); 2802 2803 if (!skb->priority && skb->sk && map) { 2804 unsigned int prioidx = skb->sk->sk_cgrp_prioidx; 2805 2806 if (prioidx < map->priomap_len) 2807 skb->priority = map->priomap[prioidx]; 2808 } 2809 } 2810 #else 2811 #define skb_update_prio(skb) 2812 #endif 2813 2814 static DEFINE_PER_CPU(int, xmit_recursion); 2815 #define RECURSION_LIMIT 10 2816 2817 /** 2818 * dev_loopback_xmit - loop back @skb 2819 * @skb: buffer to transmit 2820 */ 2821 int dev_loopback_xmit(struct sk_buff *skb) 2822 { 2823 skb_reset_mac_header(skb); 2824 __skb_pull(skb, skb_network_offset(skb)); 2825 skb->pkt_type = PACKET_LOOPBACK; 2826 skb->ip_summed = CHECKSUM_UNNECESSARY; 2827 WARN_ON(!skb_dst(skb)); 2828 skb_dst_force(skb); 2829 netif_rx_ni(skb); 2830 return 0; 2831 } 2832 EXPORT_SYMBOL(dev_loopback_xmit); 2833 2834 /** 2835 * __dev_queue_xmit - transmit a buffer 2836 * @skb: buffer to transmit 2837 * @accel_priv: private data used for L2 forwarding offload 2838 * 2839 * Queue a buffer for transmission to a network device. The caller must 2840 * have set the device and priority and built the buffer before calling 2841 * this function. The function can be called from an interrupt. 2842 * 2843 * A negative errno code is returned on a failure. A success does not 2844 * guarantee the frame will be transmitted as it may be dropped due 2845 * to congestion or traffic shaping. 2846 * 2847 * ----------------------------------------------------------------------------------- 2848 * I notice this method can also return errors from the queue disciplines, 2849 * including NET_XMIT_DROP, which is a positive value. So, errors can also 2850 * be positive. 2851 * 2852 * Regardless of the return value, the skb is consumed, so it is currently 2853 * difficult to retry a send to this method. (You can bump the ref count 2854 * before sending to hold a reference for retry if you are careful.) 2855 * 2856 * When calling this method, interrupts MUST be enabled. This is because 2857 * the BH enable code must have IRQs enabled so that it will not deadlock. 2858 * --BLG 2859 */ 2860 static int __dev_queue_xmit(struct sk_buff *skb, void *accel_priv) 2861 { 2862 struct net_device *dev = skb->dev; 2863 struct netdev_queue *txq; 2864 struct Qdisc *q; 2865 int rc = -ENOMEM; 2866 2867 skb_reset_mac_header(skb); 2868 2869 /* Disable soft irqs for various locks below. Also 2870 * stops preemption for RCU. 2871 */ 2872 rcu_read_lock_bh(); 2873 2874 skb_update_prio(skb); 2875 2876 txq = netdev_pick_tx(dev, skb, accel_priv); 2877 q = rcu_dereference_bh(txq->qdisc); 2878 2879 #ifdef CONFIG_NET_CLS_ACT 2880 skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_EGRESS); 2881 #endif 2882 trace_net_dev_queue(skb); 2883 if (q->enqueue) { 2884 rc = __dev_xmit_skb(skb, q, dev, txq); 2885 goto out; 2886 } 2887 2888 /* The device has no queue. Common case for software devices: 2889 loopback, all the sorts of tunnels... 2890 2891 Really, it is unlikely that netif_tx_lock protection is necessary 2892 here. (f.e. loopback and IP tunnels are clean ignoring statistics 2893 counters.) 2894 However, it is possible, that they rely on protection 2895 made by us here. 2896 2897 Check this and shot the lock. It is not prone from deadlocks. 2898 Either shot noqueue qdisc, it is even simpler 8) 2899 */ 2900 if (dev->flags & IFF_UP) { 2901 int cpu = smp_processor_id(); /* ok because BHs are off */ 2902 2903 if (txq->xmit_lock_owner != cpu) { 2904 2905 if (__this_cpu_read(xmit_recursion) > RECURSION_LIMIT) 2906 goto recursion_alert; 2907 2908 HARD_TX_LOCK(dev, txq, cpu); 2909 2910 if (!netif_xmit_stopped(txq)) { 2911 __this_cpu_inc(xmit_recursion); 2912 rc = dev_hard_start_xmit(skb, dev, txq); 2913 __this_cpu_dec(xmit_recursion); 2914 if (dev_xmit_complete(rc)) { 2915 HARD_TX_UNLOCK(dev, txq); 2916 goto out; 2917 } 2918 } 2919 HARD_TX_UNLOCK(dev, txq); 2920 net_crit_ratelimited("Virtual device %s asks to queue packet!\n", 2921 dev->name); 2922 } else { 2923 /* Recursion is detected! It is possible, 2924 * unfortunately 2925 */ 2926 recursion_alert: 2927 net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n", 2928 dev->name); 2929 } 2930 } 2931 2932 rc = -ENETDOWN; 2933 rcu_read_unlock_bh(); 2934 2935 atomic_long_inc(&dev->tx_dropped); 2936 kfree_skb(skb); 2937 return rc; 2938 out: 2939 rcu_read_unlock_bh(); 2940 return rc; 2941 } 2942 2943 int dev_queue_xmit(struct sk_buff *skb) 2944 { 2945 return __dev_queue_xmit(skb, NULL); 2946 } 2947 EXPORT_SYMBOL(dev_queue_xmit); 2948 2949 int dev_queue_xmit_accel(struct sk_buff *skb, void *accel_priv) 2950 { 2951 return __dev_queue_xmit(skb, accel_priv); 2952 } 2953 EXPORT_SYMBOL(dev_queue_xmit_accel); 2954 2955 2956 /*======================================================================= 2957 Receiver routines 2958 =======================================================================*/ 2959 2960 int netdev_max_backlog __read_mostly = 1000; 2961 EXPORT_SYMBOL(netdev_max_backlog); 2962 2963 int netdev_tstamp_prequeue __read_mostly = 1; 2964 int netdev_budget __read_mostly = 300; 2965 int weight_p __read_mostly = 64; /* old backlog weight */ 2966 2967 /* Called with irq disabled */ 2968 static inline void ____napi_schedule(struct softnet_data *sd, 2969 struct napi_struct *napi) 2970 { 2971 list_add_tail(&napi->poll_list, &sd->poll_list); 2972 __raise_softirq_irqoff(NET_RX_SOFTIRQ); 2973 } 2974 2975 #ifdef CONFIG_RPS 2976 2977 /* One global table that all flow-based protocols share. */ 2978 struct rps_sock_flow_table __rcu *rps_sock_flow_table __read_mostly; 2979 EXPORT_SYMBOL(rps_sock_flow_table); 2980 2981 struct static_key rps_needed __read_mostly; 2982 2983 static struct rps_dev_flow * 2984 set_rps_cpu(struct net_device *dev, struct sk_buff *skb, 2985 struct rps_dev_flow *rflow, u16 next_cpu) 2986 { 2987 if (next_cpu != RPS_NO_CPU) { 2988 #ifdef CONFIG_RFS_ACCEL 2989 struct netdev_rx_queue *rxqueue; 2990 struct rps_dev_flow_table *flow_table; 2991 struct rps_dev_flow *old_rflow; 2992 u32 flow_id; 2993 u16 rxq_index; 2994 int rc; 2995 2996 /* Should we steer this flow to a different hardware queue? */ 2997 if (!skb_rx_queue_recorded(skb) || !dev->rx_cpu_rmap || 2998 !(dev->features & NETIF_F_NTUPLE)) 2999 goto out; 3000 rxq_index = cpu_rmap_lookup_index(dev->rx_cpu_rmap, next_cpu); 3001 if (rxq_index == skb_get_rx_queue(skb)) 3002 goto out; 3003 3004 rxqueue = dev->_rx + rxq_index; 3005 flow_table = rcu_dereference(rxqueue->rps_flow_table); 3006 if (!flow_table) 3007 goto out; 3008 flow_id = skb_get_hash(skb) & flow_table->mask; 3009 rc = dev->netdev_ops->ndo_rx_flow_steer(dev, skb, 3010 rxq_index, flow_id); 3011 if (rc < 0) 3012 goto out; 3013 old_rflow = rflow; 3014 rflow = &flow_table->flows[flow_id]; 3015 rflow->filter = rc; 3016 if (old_rflow->filter == rflow->filter) 3017 old_rflow->filter = RPS_NO_FILTER; 3018 out: 3019 #endif 3020 rflow->last_qtail = 3021 per_cpu(softnet_data, next_cpu).input_queue_head; 3022 } 3023 3024 rflow->cpu = next_cpu; 3025 return rflow; 3026 } 3027 3028 /* 3029 * get_rps_cpu is called from netif_receive_skb and returns the target 3030 * CPU from the RPS map of the receiving queue for a given skb. 3031 * rcu_read_lock must be held on entry. 3032 */ 3033 static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb, 3034 struct rps_dev_flow **rflowp) 3035 { 3036 struct netdev_rx_queue *rxqueue; 3037 struct rps_map *map; 3038 struct rps_dev_flow_table *flow_table; 3039 struct rps_sock_flow_table *sock_flow_table; 3040 int cpu = -1; 3041 u16 tcpu; 3042 u32 hash; 3043 3044 if (skb_rx_queue_recorded(skb)) { 3045 u16 index = skb_get_rx_queue(skb); 3046 if (unlikely(index >= dev->real_num_rx_queues)) { 3047 WARN_ONCE(dev->real_num_rx_queues > 1, 3048 "%s received packet on queue %u, but number " 3049 "of RX queues is %u\n", 3050 dev->name, index, dev->real_num_rx_queues); 3051 goto done; 3052 } 3053 rxqueue = dev->_rx + index; 3054 } else 3055 rxqueue = dev->_rx; 3056 3057 map = rcu_dereference(rxqueue->rps_map); 3058 if (map) { 3059 if (map->len == 1 && 3060 !rcu_access_pointer(rxqueue->rps_flow_table)) { 3061 tcpu = map->cpus[0]; 3062 if (cpu_online(tcpu)) 3063 cpu = tcpu; 3064 goto done; 3065 } 3066 } else if (!rcu_access_pointer(rxqueue->rps_flow_table)) { 3067 goto done; 3068 } 3069 3070 skb_reset_network_header(skb); 3071 hash = skb_get_hash(skb); 3072 if (!hash) 3073 goto done; 3074 3075 flow_table = rcu_dereference(rxqueue->rps_flow_table); 3076 sock_flow_table = rcu_dereference(rps_sock_flow_table); 3077 if (flow_table && sock_flow_table) { 3078 u16 next_cpu; 3079 struct rps_dev_flow *rflow; 3080 3081 rflow = &flow_table->flows[hash & flow_table->mask]; 3082 tcpu = rflow->cpu; 3083 3084 next_cpu = sock_flow_table->ents[hash & sock_flow_table->mask]; 3085 3086 /* 3087 * If the desired CPU (where last recvmsg was done) is 3088 * different from current CPU (one in the rx-queue flow 3089 * table entry), switch if one of the following holds: 3090 * - Current CPU is unset (equal to RPS_NO_CPU). 3091 * - Current CPU is offline. 3092 * - The current CPU's queue tail has advanced beyond the 3093 * last packet that was enqueued using this table entry. 3094 * This guarantees that all previous packets for the flow 3095 * have been dequeued, thus preserving in order delivery. 3096 */ 3097 if (unlikely(tcpu != next_cpu) && 3098 (tcpu == RPS_NO_CPU || !cpu_online(tcpu) || 3099 ((int)(per_cpu(softnet_data, tcpu).input_queue_head - 3100 rflow->last_qtail)) >= 0)) { 3101 tcpu = next_cpu; 3102 rflow = set_rps_cpu(dev, skb, rflow, next_cpu); 3103 } 3104 3105 if (tcpu != RPS_NO_CPU && cpu_online(tcpu)) { 3106 *rflowp = rflow; 3107 cpu = tcpu; 3108 goto done; 3109 } 3110 } 3111 3112 if (map) { 3113 tcpu = map->cpus[((u64) hash * map->len) >> 32]; 3114 3115 if (cpu_online(tcpu)) { 3116 cpu = tcpu; 3117 goto done; 3118 } 3119 } 3120 3121 done: 3122 return cpu; 3123 } 3124 3125 #ifdef CONFIG_RFS_ACCEL 3126 3127 /** 3128 * rps_may_expire_flow - check whether an RFS hardware filter may be removed 3129 * @dev: Device on which the filter was set 3130 * @rxq_index: RX queue index 3131 * @flow_id: Flow ID passed to ndo_rx_flow_steer() 3132 * @filter_id: Filter ID returned by ndo_rx_flow_steer() 3133 * 3134 * Drivers that implement ndo_rx_flow_steer() should periodically call 3135 * this function for each installed filter and remove the filters for 3136 * which it returns %true. 3137 */ 3138 bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index, 3139 u32 flow_id, u16 filter_id) 3140 { 3141 struct netdev_rx_queue *rxqueue = dev->_rx + rxq_index; 3142 struct rps_dev_flow_table *flow_table; 3143 struct rps_dev_flow *rflow; 3144 bool expire = true; 3145 int cpu; 3146 3147 rcu_read_lock(); 3148 flow_table = rcu_dereference(rxqueue->rps_flow_table); 3149 if (flow_table && flow_id <= flow_table->mask) { 3150 rflow = &flow_table->flows[flow_id]; 3151 cpu = ACCESS_ONCE(rflow->cpu); 3152 if (rflow->filter == filter_id && cpu != RPS_NO_CPU && 3153 ((int)(per_cpu(softnet_data, cpu).input_queue_head - 3154 rflow->last_qtail) < 3155 (int)(10 * flow_table->mask))) 3156 expire = false; 3157 } 3158 rcu_read_unlock(); 3159 return expire; 3160 } 3161 EXPORT_SYMBOL(rps_may_expire_flow); 3162 3163 #endif /* CONFIG_RFS_ACCEL */ 3164 3165 /* Called from hardirq (IPI) context */ 3166 static void rps_trigger_softirq(void *data) 3167 { 3168 struct softnet_data *sd = data; 3169 3170 ____napi_schedule(sd, &sd->backlog); 3171 sd->received_rps++; 3172 } 3173 3174 #endif /* CONFIG_RPS */ 3175 3176 /* 3177 * Check if this softnet_data structure is another cpu one 3178 * If yes, queue it to our IPI list and return 1 3179 * If no, return 0 3180 */ 3181 static int rps_ipi_queued(struct softnet_data *sd) 3182 { 3183 #ifdef CONFIG_RPS 3184 struct softnet_data *mysd = &__get_cpu_var(softnet_data); 3185 3186 if (sd != mysd) { 3187 sd->rps_ipi_next = mysd->rps_ipi_list; 3188 mysd->rps_ipi_list = sd; 3189 3190 __raise_softirq_irqoff(NET_RX_SOFTIRQ); 3191 return 1; 3192 } 3193 #endif /* CONFIG_RPS */ 3194 return 0; 3195 } 3196 3197 #ifdef CONFIG_NET_FLOW_LIMIT 3198 int netdev_flow_limit_table_len __read_mostly = (1 << 12); 3199 #endif 3200 3201 static bool skb_flow_limit(struct sk_buff *skb, unsigned int qlen) 3202 { 3203 #ifdef CONFIG_NET_FLOW_LIMIT 3204 struct sd_flow_limit *fl; 3205 struct softnet_data *sd; 3206 unsigned int old_flow, new_flow; 3207 3208 if (qlen < (netdev_max_backlog >> 1)) 3209 return false; 3210 3211 sd = &__get_cpu_var(softnet_data); 3212 3213 rcu_read_lock(); 3214 fl = rcu_dereference(sd->flow_limit); 3215 if (fl) { 3216 new_flow = skb_get_hash(skb) & (fl->num_buckets - 1); 3217 old_flow = fl->history[fl->history_head]; 3218 fl->history[fl->history_head] = new_flow; 3219 3220 fl->history_head++; 3221 fl->history_head &= FLOW_LIMIT_HISTORY - 1; 3222 3223 if (likely(fl->buckets[old_flow])) 3224 fl->buckets[old_flow]--; 3225 3226 if (++fl->buckets[new_flow] > (FLOW_LIMIT_HISTORY >> 1)) { 3227 fl->count++; 3228 rcu_read_unlock(); 3229 return true; 3230 } 3231 } 3232 rcu_read_unlock(); 3233 #endif 3234 return false; 3235 } 3236 3237 /* 3238 * enqueue_to_backlog is called to queue an skb to a per CPU backlog 3239 * queue (may be a remote CPU queue). 3240 */ 3241 static int enqueue_to_backlog(struct sk_buff *skb, int cpu, 3242 unsigned int *qtail) 3243 { 3244 struct softnet_data *sd; 3245 unsigned long flags; 3246 unsigned int qlen; 3247 3248 sd = &per_cpu(softnet_data, cpu); 3249 3250 local_irq_save(flags); 3251 3252 rps_lock(sd); 3253 qlen = skb_queue_len(&sd->input_pkt_queue); 3254 if (qlen <= netdev_max_backlog && !skb_flow_limit(skb, qlen)) { 3255 if (skb_queue_len(&sd->input_pkt_queue)) { 3256 enqueue: 3257 __skb_queue_tail(&sd->input_pkt_queue, skb); 3258 input_queue_tail_incr_save(sd, qtail); 3259 rps_unlock(sd); 3260 local_irq_restore(flags); 3261 return NET_RX_SUCCESS; 3262 } 3263 3264 /* Schedule NAPI for backlog device 3265 * We can use non atomic operation since we own the queue lock 3266 */ 3267 if (!__test_and_set_bit(NAPI_STATE_SCHED, &sd->backlog.state)) { 3268 if (!rps_ipi_queued(sd)) 3269 ____napi_schedule(sd, &sd->backlog); 3270 } 3271 goto enqueue; 3272 } 3273 3274 sd->dropped++; 3275 rps_unlock(sd); 3276 3277 local_irq_restore(flags); 3278 3279 atomic_long_inc(&skb->dev->rx_dropped); 3280 kfree_skb(skb); 3281 return NET_RX_DROP; 3282 } 3283 3284 static int netif_rx_internal(struct sk_buff *skb) 3285 { 3286 int ret; 3287 3288 net_timestamp_check(netdev_tstamp_prequeue, skb); 3289 3290 trace_netif_rx(skb); 3291 #ifdef CONFIG_RPS 3292 if (static_key_false(&rps_needed)) { 3293 struct rps_dev_flow voidflow, *rflow = &voidflow; 3294 int cpu; 3295 3296 preempt_disable(); 3297 rcu_read_lock(); 3298 3299 cpu = get_rps_cpu(skb->dev, skb, &rflow); 3300 if (cpu < 0) 3301 cpu = smp_processor_id(); 3302 3303 ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail); 3304 3305 rcu_read_unlock(); 3306 preempt_enable(); 3307 } else 3308 #endif 3309 { 3310 unsigned int qtail; 3311 ret = enqueue_to_backlog(skb, get_cpu(), &qtail); 3312 put_cpu(); 3313 } 3314 return ret; 3315 } 3316 3317 /** 3318 * netif_rx - post buffer to the network code 3319 * @skb: buffer to post 3320 * 3321 * This function receives a packet from a device driver and queues it for 3322 * the upper (protocol) levels to process. It always succeeds. The buffer 3323 * may be dropped during processing for congestion control or by the 3324 * protocol layers. 3325 * 3326 * return values: 3327 * NET_RX_SUCCESS (no congestion) 3328 * NET_RX_DROP (packet was dropped) 3329 * 3330 */ 3331 3332 int netif_rx(struct sk_buff *skb) 3333 { 3334 trace_netif_rx_entry(skb); 3335 3336 return netif_rx_internal(skb); 3337 } 3338 EXPORT_SYMBOL(netif_rx); 3339 3340 int netif_rx_ni(struct sk_buff *skb) 3341 { 3342 int err; 3343 3344 trace_netif_rx_ni_entry(skb); 3345 3346 preempt_disable(); 3347 err = netif_rx_internal(skb); 3348 if (local_softirq_pending()) 3349 do_softirq(); 3350 preempt_enable(); 3351 3352 return err; 3353 } 3354 EXPORT_SYMBOL(netif_rx_ni); 3355 3356 static void net_tx_action(struct softirq_action *h) 3357 { 3358 struct softnet_data *sd = &__get_cpu_var(softnet_data); 3359 3360 if (sd->completion_queue) { 3361 struct sk_buff *clist; 3362 3363 local_irq_disable(); 3364 clist = sd->completion_queue; 3365 sd->completion_queue = NULL; 3366 local_irq_enable(); 3367 3368 while (clist) { 3369 struct sk_buff *skb = clist; 3370 clist = clist->next; 3371 3372 WARN_ON(atomic_read(&skb->users)); 3373 if (likely(get_kfree_skb_cb(skb)->reason == SKB_REASON_CONSUMED)) 3374 trace_consume_skb(skb); 3375 else 3376 trace_kfree_skb(skb, net_tx_action); 3377 __kfree_skb(skb); 3378 } 3379 } 3380 3381 if (sd->output_queue) { 3382 struct Qdisc *head; 3383 3384 local_irq_disable(); 3385 head = sd->output_queue; 3386 sd->output_queue = NULL; 3387 sd->output_queue_tailp = &sd->output_queue; 3388 local_irq_enable(); 3389 3390 while (head) { 3391 struct Qdisc *q = head; 3392 spinlock_t *root_lock; 3393 3394 head = head->next_sched; 3395 3396 root_lock = qdisc_lock(q); 3397 if (spin_trylock(root_lock)) { 3398 smp_mb__before_atomic(); 3399 clear_bit(__QDISC_STATE_SCHED, 3400 &q->state); 3401 qdisc_run(q); 3402 spin_unlock(root_lock); 3403 } else { 3404 if (!test_bit(__QDISC_STATE_DEACTIVATED, 3405 &q->state)) { 3406 __netif_reschedule(q); 3407 } else { 3408 smp_mb__before_atomic(); 3409 clear_bit(__QDISC_STATE_SCHED, 3410 &q->state); 3411 } 3412 } 3413 } 3414 } 3415 } 3416 3417 #if (defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)) && \ 3418 (defined(CONFIG_ATM_LANE) || defined(CONFIG_ATM_LANE_MODULE)) 3419 /* This hook is defined here for ATM LANE */ 3420 int (*br_fdb_test_addr_hook)(struct net_device *dev, 3421 unsigned char *addr) __read_mostly; 3422 EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook); 3423 #endif 3424 3425 #ifdef CONFIG_NET_CLS_ACT 3426 /* TODO: Maybe we should just force sch_ingress to be compiled in 3427 * when CONFIG_NET_CLS_ACT is? otherwise some useless instructions 3428 * a compare and 2 stores extra right now if we dont have it on 3429 * but have CONFIG_NET_CLS_ACT 3430 * NOTE: This doesn't stop any functionality; if you dont have 3431 * the ingress scheduler, you just can't add policies on ingress. 3432 * 3433 */ 3434 static int ing_filter(struct sk_buff *skb, struct netdev_queue *rxq) 3435 { 3436 struct net_device *dev = skb->dev; 3437 u32 ttl = G_TC_RTTL(skb->tc_verd); 3438 int result = TC_ACT_OK; 3439 struct Qdisc *q; 3440 3441 if (unlikely(MAX_RED_LOOP < ttl++)) { 3442 net_warn_ratelimited("Redir loop detected Dropping packet (%d->%d)\n", 3443 skb->skb_iif, dev->ifindex); 3444 return TC_ACT_SHOT; 3445 } 3446 3447 skb->tc_verd = SET_TC_RTTL(skb->tc_verd, ttl); 3448 skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_INGRESS); 3449 3450 q = rxq->qdisc; 3451 if (q != &noop_qdisc) { 3452 spin_lock(qdisc_lock(q)); 3453 if (likely(!test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) 3454 result = qdisc_enqueue_root(skb, q); 3455 spin_unlock(qdisc_lock(q)); 3456 } 3457 3458 return result; 3459 } 3460 3461 static inline struct sk_buff *handle_ing(struct sk_buff *skb, 3462 struct packet_type **pt_prev, 3463 int *ret, struct net_device *orig_dev) 3464 { 3465 struct netdev_queue *rxq = rcu_dereference(skb->dev->ingress_queue); 3466 3467 if (!rxq || rxq->qdisc == &noop_qdisc) 3468 goto out; 3469 3470 if (*pt_prev) { 3471 *ret = deliver_skb(skb, *pt_prev, orig_dev); 3472 *pt_prev = NULL; 3473 } 3474 3475 switch (ing_filter(skb, rxq)) { 3476 case TC_ACT_SHOT: 3477 case TC_ACT_STOLEN: 3478 kfree_skb(skb); 3479 return NULL; 3480 } 3481 3482 out: 3483 skb->tc_verd = 0; 3484 return skb; 3485 } 3486 #endif 3487 3488 /** 3489 * netdev_rx_handler_register - register receive handler 3490 * @dev: device to register a handler for 3491 * @rx_handler: receive handler to register 3492 * @rx_handler_data: data pointer that is used by rx handler 3493 * 3494 * Register a receive handler for a device. This handler will then be 3495 * called from __netif_receive_skb. A negative errno code is returned 3496 * on a failure. 3497 * 3498 * The caller must hold the rtnl_mutex. 3499 * 3500 * For a general description of rx_handler, see enum rx_handler_result. 3501 */ 3502 int netdev_rx_handler_register(struct net_device *dev, 3503 rx_handler_func_t *rx_handler, 3504 void *rx_handler_data) 3505 { 3506 ASSERT_RTNL(); 3507 3508 if (dev->rx_handler) 3509 return -EBUSY; 3510 3511 /* Note: rx_handler_data must be set before rx_handler */ 3512 rcu_assign_pointer(dev->rx_handler_data, rx_handler_data); 3513 rcu_assign_pointer(dev->rx_handler, rx_handler); 3514 3515 return 0; 3516 } 3517 EXPORT_SYMBOL_GPL(netdev_rx_handler_register); 3518 3519 /** 3520 * netdev_rx_handler_unregister - unregister receive handler 3521 * @dev: device to unregister a handler from 3522 * 3523 * Unregister a receive handler from a device. 3524 * 3525 * The caller must hold the rtnl_mutex. 3526 */ 3527 void netdev_rx_handler_unregister(struct net_device *dev) 3528 { 3529 3530 ASSERT_RTNL(); 3531 RCU_INIT_POINTER(dev->rx_handler, NULL); 3532 /* a reader seeing a non NULL rx_handler in a rcu_read_lock() 3533 * section has a guarantee to see a non NULL rx_handler_data 3534 * as well. 3535 */ 3536 synchronize_net(); 3537 RCU_INIT_POINTER(dev->rx_handler_data, NULL); 3538 } 3539 EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister); 3540 3541 /* 3542 * Limit the use of PFMEMALLOC reserves to those protocols that implement 3543 * the special handling of PFMEMALLOC skbs. 3544 */ 3545 static bool skb_pfmemalloc_protocol(struct sk_buff *skb) 3546 { 3547 switch (skb->protocol) { 3548 case htons(ETH_P_ARP): 3549 case htons(ETH_P_IP): 3550 case htons(ETH_P_IPV6): 3551 case htons(ETH_P_8021Q): 3552 case htons(ETH_P_8021AD): 3553 return true; 3554 default: 3555 return false; 3556 } 3557 } 3558 3559 static int __netif_receive_skb_core(struct sk_buff *skb, bool pfmemalloc) 3560 { 3561 struct packet_type *ptype, *pt_prev; 3562 rx_handler_func_t *rx_handler; 3563 struct net_device *orig_dev; 3564 struct net_device *null_or_dev; 3565 bool deliver_exact = false; 3566 int ret = NET_RX_DROP; 3567 __be16 type; 3568 3569 net_timestamp_check(!netdev_tstamp_prequeue, skb); 3570 3571 trace_netif_receive_skb(skb); 3572 3573 orig_dev = skb->dev; 3574 3575 skb_reset_network_header(skb); 3576 if (!skb_transport_header_was_set(skb)) 3577 skb_reset_transport_header(skb); 3578 skb_reset_mac_len(skb); 3579 3580 pt_prev = NULL; 3581 3582 rcu_read_lock(); 3583 3584 another_round: 3585 skb->skb_iif = skb->dev->ifindex; 3586 3587 __this_cpu_inc(softnet_data.processed); 3588 3589 if (skb->protocol == cpu_to_be16(ETH_P_8021Q) || 3590 skb->protocol == cpu_to_be16(ETH_P_8021AD)) { 3591 skb = vlan_untag(skb); 3592 if (unlikely(!skb)) 3593 goto unlock; 3594 } 3595 3596 #ifdef CONFIG_NET_CLS_ACT 3597 if (skb->tc_verd & TC_NCLS) { 3598 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd); 3599 goto ncls; 3600 } 3601 #endif 3602 3603 if (pfmemalloc) 3604 goto skip_taps; 3605 3606 list_for_each_entry_rcu(ptype, &ptype_all, list) { 3607 if (!ptype->dev || ptype->dev == skb->dev) { 3608 if (pt_prev) 3609 ret = deliver_skb(skb, pt_prev, orig_dev); 3610 pt_prev = ptype; 3611 } 3612 } 3613 3614 skip_taps: 3615 #ifdef CONFIG_NET_CLS_ACT 3616 skb = handle_ing(skb, &pt_prev, &ret, orig_dev); 3617 if (!skb) 3618 goto unlock; 3619 ncls: 3620 #endif 3621 3622 if (pfmemalloc && !skb_pfmemalloc_protocol(skb)) 3623 goto drop; 3624 3625 if (vlan_tx_tag_present(skb)) { 3626 if (pt_prev) { 3627 ret = deliver_skb(skb, pt_prev, orig_dev); 3628 pt_prev = NULL; 3629 } 3630 if (vlan_do_receive(&skb)) 3631 goto another_round; 3632 else if (unlikely(!skb)) 3633 goto unlock; 3634 } 3635 3636 rx_handler = rcu_dereference(skb->dev->rx_handler); 3637 if (rx_handler) { 3638 if (pt_prev) { 3639 ret = deliver_skb(skb, pt_prev, orig_dev); 3640 pt_prev = NULL; 3641 } 3642 switch (rx_handler(&skb)) { 3643 case RX_HANDLER_CONSUMED: 3644 ret = NET_RX_SUCCESS; 3645 goto unlock; 3646 case RX_HANDLER_ANOTHER: 3647 goto another_round; 3648 case RX_HANDLER_EXACT: 3649 deliver_exact = true; 3650 case RX_HANDLER_PASS: 3651 break; 3652 default: 3653 BUG(); 3654 } 3655 } 3656 3657 if (unlikely(vlan_tx_tag_present(skb))) { 3658 if (vlan_tx_tag_get_id(skb)) 3659 skb->pkt_type = PACKET_OTHERHOST; 3660 /* Note: we might in the future use prio bits 3661 * and set skb->priority like in vlan_do_receive() 3662 * For the time being, just ignore Priority Code Point 3663 */ 3664 skb->vlan_tci = 0; 3665 } 3666 3667 /* deliver only exact match when indicated */ 3668 null_or_dev = deliver_exact ? skb->dev : NULL; 3669 3670 type = skb->protocol; 3671 list_for_each_entry_rcu(ptype, 3672 &ptype_base[ntohs(type) & PTYPE_HASH_MASK], list) { 3673 if (ptype->type == type && 3674 (ptype->dev == null_or_dev || ptype->dev == skb->dev || 3675 ptype->dev == orig_dev)) { 3676 if (pt_prev) 3677 ret = deliver_skb(skb, pt_prev, orig_dev); 3678 pt_prev = ptype; 3679 } 3680 } 3681 3682 if (pt_prev) { 3683 if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC))) 3684 goto drop; 3685 else 3686 ret = pt_prev->func(skb, skb->dev, pt_prev, orig_dev); 3687 } else { 3688 drop: 3689 atomic_long_inc(&skb->dev->rx_dropped); 3690 kfree_skb(skb); 3691 /* Jamal, now you will not able to escape explaining 3692 * me how you were going to use this. :-) 3693 */ 3694 ret = NET_RX_DROP; 3695 } 3696 3697 unlock: 3698 rcu_read_unlock(); 3699 return ret; 3700 } 3701 3702 static int __netif_receive_skb(struct sk_buff *skb) 3703 { 3704 int ret; 3705 3706 if (sk_memalloc_socks() && skb_pfmemalloc(skb)) { 3707 unsigned long pflags = current->flags; 3708 3709 /* 3710 * PFMEMALLOC skbs are special, they should 3711 * - be delivered to SOCK_MEMALLOC sockets only 3712 * - stay away from userspace 3713 * - have bounded memory usage 3714 * 3715 * Use PF_MEMALLOC as this saves us from propagating the allocation 3716 * context down to all allocation sites. 3717 */ 3718 current->flags |= PF_MEMALLOC; 3719 ret = __netif_receive_skb_core(skb, true); 3720 tsk_restore_flags(current, pflags, PF_MEMALLOC); 3721 } else 3722 ret = __netif_receive_skb_core(skb, false); 3723 3724 return ret; 3725 } 3726 3727 static int netif_receive_skb_internal(struct sk_buff *skb) 3728 { 3729 net_timestamp_check(netdev_tstamp_prequeue, skb); 3730 3731 if (skb_defer_rx_timestamp(skb)) 3732 return NET_RX_SUCCESS; 3733 3734 #ifdef CONFIG_RPS 3735 if (static_key_false(&rps_needed)) { 3736 struct rps_dev_flow voidflow, *rflow = &voidflow; 3737 int cpu, ret; 3738 3739 rcu_read_lock(); 3740 3741 cpu = get_rps_cpu(skb->dev, skb, &rflow); 3742 3743 if (cpu >= 0) { 3744 ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail); 3745 rcu_read_unlock(); 3746 return ret; 3747 } 3748 rcu_read_unlock(); 3749 } 3750 #endif 3751 return __netif_receive_skb(skb); 3752 } 3753 3754 /** 3755 * netif_receive_skb - process receive buffer from network 3756 * @skb: buffer to process 3757 * 3758 * netif_receive_skb() is the main receive data processing function. 3759 * It always succeeds. The buffer may be dropped during processing 3760 * for congestion control or by the protocol layers. 3761 * 3762 * This function may only be called from softirq context and interrupts 3763 * should be enabled. 3764 * 3765 * Return values (usually ignored): 3766 * NET_RX_SUCCESS: no congestion 3767 * NET_RX_DROP: packet was dropped 3768 */ 3769 int netif_receive_skb(struct sk_buff *skb) 3770 { 3771 trace_netif_receive_skb_entry(skb); 3772 3773 return netif_receive_skb_internal(skb); 3774 } 3775 EXPORT_SYMBOL(netif_receive_skb); 3776 3777 /* Network device is going away, flush any packets still pending 3778 * Called with irqs disabled. 3779 */ 3780 static void flush_backlog(void *arg) 3781 { 3782 struct net_device *dev = arg; 3783 struct softnet_data *sd = &__get_cpu_var(softnet_data); 3784 struct sk_buff *skb, *tmp; 3785 3786 rps_lock(sd); 3787 skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) { 3788 if (skb->dev == dev) { 3789 __skb_unlink(skb, &sd->input_pkt_queue); 3790 kfree_skb(skb); 3791 input_queue_head_incr(sd); 3792 } 3793 } 3794 rps_unlock(sd); 3795 3796 skb_queue_walk_safe(&sd->process_queue, skb, tmp) { 3797 if (skb->dev == dev) { 3798 __skb_unlink(skb, &sd->process_queue); 3799 kfree_skb(skb); 3800 input_queue_head_incr(sd); 3801 } 3802 } 3803 } 3804 3805 static int napi_gro_complete(struct sk_buff *skb) 3806 { 3807 struct packet_offload *ptype; 3808 __be16 type = skb->protocol; 3809 struct list_head *head = &offload_base; 3810 int err = -ENOENT; 3811 3812 BUILD_BUG_ON(sizeof(struct napi_gro_cb) > sizeof(skb->cb)); 3813 3814 if (NAPI_GRO_CB(skb)->count == 1) { 3815 skb_shinfo(skb)->gso_size = 0; 3816 goto out; 3817 } 3818 3819 rcu_read_lock(); 3820 list_for_each_entry_rcu(ptype, head, list) { 3821 if (ptype->type != type || !ptype->callbacks.gro_complete) 3822 continue; 3823 3824 err = ptype->callbacks.gro_complete(skb, 0); 3825 break; 3826 } 3827 rcu_read_unlock(); 3828 3829 if (err) { 3830 WARN_ON(&ptype->list == head); 3831 kfree_skb(skb); 3832 return NET_RX_SUCCESS; 3833 } 3834 3835 out: 3836 return netif_receive_skb_internal(skb); 3837 } 3838 3839 /* napi->gro_list contains packets ordered by age. 3840 * youngest packets at the head of it. 3841 * Complete skbs in reverse order to reduce latencies. 3842 */ 3843 void napi_gro_flush(struct napi_struct *napi, bool flush_old) 3844 { 3845 struct sk_buff *skb, *prev = NULL; 3846 3847 /* scan list and build reverse chain */ 3848 for (skb = napi->gro_list; skb != NULL; skb = skb->next) { 3849 skb->prev = prev; 3850 prev = skb; 3851 } 3852 3853 for (skb = prev; skb; skb = prev) { 3854 skb->next = NULL; 3855 3856 if (flush_old && NAPI_GRO_CB(skb)->age == jiffies) 3857 return; 3858 3859 prev = skb->prev; 3860 napi_gro_complete(skb); 3861 napi->gro_count--; 3862 } 3863 3864 napi->gro_list = NULL; 3865 } 3866 EXPORT_SYMBOL(napi_gro_flush); 3867 3868 static void gro_list_prepare(struct napi_struct *napi, struct sk_buff *skb) 3869 { 3870 struct sk_buff *p; 3871 unsigned int maclen = skb->dev->hard_header_len; 3872 u32 hash = skb_get_hash_raw(skb); 3873 3874 for (p = napi->gro_list; p; p = p->next) { 3875 unsigned long diffs; 3876 3877 NAPI_GRO_CB(p)->flush = 0; 3878 3879 if (hash != skb_get_hash_raw(p)) { 3880 NAPI_GRO_CB(p)->same_flow = 0; 3881 continue; 3882 } 3883 3884 diffs = (unsigned long)p->dev ^ (unsigned long)skb->dev; 3885 diffs |= p->vlan_tci ^ skb->vlan_tci; 3886 if (maclen == ETH_HLEN) 3887 diffs |= compare_ether_header(skb_mac_header(p), 3888 skb_mac_header(skb)); 3889 else if (!diffs) 3890 diffs = memcmp(skb_mac_header(p), 3891 skb_mac_header(skb), 3892 maclen); 3893 NAPI_GRO_CB(p)->same_flow = !diffs; 3894 } 3895 } 3896 3897 static void skb_gro_reset_offset(struct sk_buff *skb) 3898 { 3899 const struct skb_shared_info *pinfo = skb_shinfo(skb); 3900 const skb_frag_t *frag0 = &pinfo->frags[0]; 3901 3902 NAPI_GRO_CB(skb)->data_offset = 0; 3903 NAPI_GRO_CB(skb)->frag0 = NULL; 3904 NAPI_GRO_CB(skb)->frag0_len = 0; 3905 3906 if (skb_mac_header(skb) == skb_tail_pointer(skb) && 3907 pinfo->nr_frags && 3908 !PageHighMem(skb_frag_page(frag0))) { 3909 NAPI_GRO_CB(skb)->frag0 = skb_frag_address(frag0); 3910 NAPI_GRO_CB(skb)->frag0_len = skb_frag_size(frag0); 3911 } 3912 } 3913 3914 static void gro_pull_from_frag0(struct sk_buff *skb, int grow) 3915 { 3916 struct skb_shared_info *pinfo = skb_shinfo(skb); 3917 3918 BUG_ON(skb->end - skb->tail < grow); 3919 3920 memcpy(skb_tail_pointer(skb), NAPI_GRO_CB(skb)->frag0, grow); 3921 3922 skb->data_len -= grow; 3923 skb->tail += grow; 3924 3925 pinfo->frags[0].page_offset += grow; 3926 skb_frag_size_sub(&pinfo->frags[0], grow); 3927 3928 if (unlikely(!skb_frag_size(&pinfo->frags[0]))) { 3929 skb_frag_unref(skb, 0); 3930 memmove(pinfo->frags, pinfo->frags + 1, 3931 --pinfo->nr_frags * sizeof(pinfo->frags[0])); 3932 } 3933 } 3934 3935 static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb) 3936 { 3937 struct sk_buff **pp = NULL; 3938 struct packet_offload *ptype; 3939 __be16 type = skb->protocol; 3940 struct list_head *head = &offload_base; 3941 int same_flow; 3942 enum gro_result ret; 3943 int grow; 3944 3945 if (!(skb->dev->features & NETIF_F_GRO)) 3946 goto normal; 3947 3948 if (skb_is_gso(skb) || skb_has_frag_list(skb)) 3949 goto normal; 3950 3951 gro_list_prepare(napi, skb); 3952 NAPI_GRO_CB(skb)->csum = skb->csum; /* Needed for CHECKSUM_COMPLETE */ 3953 3954 rcu_read_lock(); 3955 list_for_each_entry_rcu(ptype, head, list) { 3956 if (ptype->type != type || !ptype->callbacks.gro_receive) 3957 continue; 3958 3959 skb_set_network_header(skb, skb_gro_offset(skb)); 3960 skb_reset_mac_len(skb); 3961 NAPI_GRO_CB(skb)->same_flow = 0; 3962 NAPI_GRO_CB(skb)->flush = 0; 3963 NAPI_GRO_CB(skb)->free = 0; 3964 NAPI_GRO_CB(skb)->udp_mark = 0; 3965 3966 pp = ptype->callbacks.gro_receive(&napi->gro_list, skb); 3967 break; 3968 } 3969 rcu_read_unlock(); 3970 3971 if (&ptype->list == head) 3972 goto normal; 3973 3974 same_flow = NAPI_GRO_CB(skb)->same_flow; 3975 ret = NAPI_GRO_CB(skb)->free ? GRO_MERGED_FREE : GRO_MERGED; 3976 3977 if (pp) { 3978 struct sk_buff *nskb = *pp; 3979 3980 *pp = nskb->next; 3981 nskb->next = NULL; 3982 napi_gro_complete(nskb); 3983 napi->gro_count--; 3984 } 3985 3986 if (same_flow) 3987 goto ok; 3988 3989 if (NAPI_GRO_CB(skb)->flush) 3990 goto normal; 3991 3992 if (unlikely(napi->gro_count >= MAX_GRO_SKBS)) { 3993 struct sk_buff *nskb = napi->gro_list; 3994 3995 /* locate the end of the list to select the 'oldest' flow */ 3996 while (nskb->next) { 3997 pp = &nskb->next; 3998 nskb = *pp; 3999 } 4000 *pp = NULL; 4001 nskb->next = NULL; 4002 napi_gro_complete(nskb); 4003 } else { 4004 napi->gro_count++; 4005 } 4006 NAPI_GRO_CB(skb)->count = 1; 4007 NAPI_GRO_CB(skb)->age = jiffies; 4008 NAPI_GRO_CB(skb)->last = skb; 4009 skb_shinfo(skb)->gso_size = skb_gro_len(skb); 4010 skb->next = napi->gro_list; 4011 napi->gro_list = skb; 4012 ret = GRO_HELD; 4013 4014 pull: 4015 grow = skb_gro_offset(skb) - skb_headlen(skb); 4016 if (grow > 0) 4017 gro_pull_from_frag0(skb, grow); 4018 ok: 4019 return ret; 4020 4021 normal: 4022 ret = GRO_NORMAL; 4023 goto pull; 4024 } 4025 4026 struct packet_offload *gro_find_receive_by_type(__be16 type) 4027 { 4028 struct list_head *offload_head = &offload_base; 4029 struct packet_offload *ptype; 4030 4031 list_for_each_entry_rcu(ptype, offload_head, list) { 4032 if (ptype->type != type || !ptype->callbacks.gro_receive) 4033 continue; 4034 return ptype; 4035 } 4036 return NULL; 4037 } 4038 EXPORT_SYMBOL(gro_find_receive_by_type); 4039 4040 struct packet_offload *gro_find_complete_by_type(__be16 type) 4041 { 4042 struct list_head *offload_head = &offload_base; 4043 struct packet_offload *ptype; 4044 4045 list_for_each_entry_rcu(ptype, offload_head, list) { 4046 if (ptype->type != type || !ptype->callbacks.gro_complete) 4047 continue; 4048 return ptype; 4049 } 4050 return NULL; 4051 } 4052 EXPORT_SYMBOL(gro_find_complete_by_type); 4053 4054 static gro_result_t napi_skb_finish(gro_result_t ret, struct sk_buff *skb) 4055 { 4056 switch (ret) { 4057 case GRO_NORMAL: 4058 if (netif_receive_skb_internal(skb)) 4059 ret = GRO_DROP; 4060 break; 4061 4062 case GRO_DROP: 4063 kfree_skb(skb); 4064 break; 4065 4066 case GRO_MERGED_FREE: 4067 if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD) 4068 kmem_cache_free(skbuff_head_cache, skb); 4069 else 4070 __kfree_skb(skb); 4071 break; 4072 4073 case GRO_HELD: 4074 case GRO_MERGED: 4075 break; 4076 } 4077 4078 return ret; 4079 } 4080 4081 gro_result_t napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb) 4082 { 4083 trace_napi_gro_receive_entry(skb); 4084 4085 skb_gro_reset_offset(skb); 4086 4087 return napi_skb_finish(dev_gro_receive(napi, skb), skb); 4088 } 4089 EXPORT_SYMBOL(napi_gro_receive); 4090 4091 static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb) 4092 { 4093 __skb_pull(skb, skb_headlen(skb)); 4094 /* restore the reserve we had after netdev_alloc_skb_ip_align() */ 4095 skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN - skb_headroom(skb)); 4096 skb->vlan_tci = 0; 4097 skb->dev = napi->dev; 4098 skb->skb_iif = 0; 4099 skb->truesize = SKB_TRUESIZE(skb_end_offset(skb)); 4100 4101 napi->skb = skb; 4102 } 4103 4104 struct sk_buff *napi_get_frags(struct napi_struct *napi) 4105 { 4106 struct sk_buff *skb = napi->skb; 4107 4108 if (!skb) { 4109 skb = netdev_alloc_skb_ip_align(napi->dev, GRO_MAX_HEAD); 4110 napi->skb = skb; 4111 } 4112 return skb; 4113 } 4114 EXPORT_SYMBOL(napi_get_frags); 4115 4116 static gro_result_t napi_frags_finish(struct napi_struct *napi, 4117 struct sk_buff *skb, 4118 gro_result_t ret) 4119 { 4120 switch (ret) { 4121 case GRO_NORMAL: 4122 case GRO_HELD: 4123 __skb_push(skb, ETH_HLEN); 4124 skb->protocol = eth_type_trans(skb, skb->dev); 4125 if (ret == GRO_NORMAL && netif_receive_skb_internal(skb)) 4126 ret = GRO_DROP; 4127 break; 4128 4129 case GRO_DROP: 4130 case GRO_MERGED_FREE: 4131 napi_reuse_skb(napi, skb); 4132 break; 4133 4134 case GRO_MERGED: 4135 break; 4136 } 4137 4138 return ret; 4139 } 4140 4141 /* Upper GRO stack assumes network header starts at gro_offset=0 4142 * Drivers could call both napi_gro_frags() and napi_gro_receive() 4143 * We copy ethernet header into skb->data to have a common layout. 4144 */ 4145 static struct sk_buff *napi_frags_skb(struct napi_struct *napi) 4146 { 4147 struct sk_buff *skb = napi->skb; 4148 const struct ethhdr *eth; 4149 unsigned int hlen = sizeof(*eth); 4150 4151 napi->skb = NULL; 4152 4153 skb_reset_mac_header(skb); 4154 skb_gro_reset_offset(skb); 4155 4156 eth = skb_gro_header_fast(skb, 0); 4157 if (unlikely(skb_gro_header_hard(skb, hlen))) { 4158 eth = skb_gro_header_slow(skb, hlen, 0); 4159 if (unlikely(!eth)) { 4160 napi_reuse_skb(napi, skb); 4161 return NULL; 4162 } 4163 } else { 4164 gro_pull_from_frag0(skb, hlen); 4165 NAPI_GRO_CB(skb)->frag0 += hlen; 4166 NAPI_GRO_CB(skb)->frag0_len -= hlen; 4167 } 4168 __skb_pull(skb, hlen); 4169 4170 /* 4171 * This works because the only protocols we care about don't require 4172 * special handling. 4173 * We'll fix it up properly in napi_frags_finish() 4174 */ 4175 skb->protocol = eth->h_proto; 4176 4177 return skb; 4178 } 4179 4180 gro_result_t napi_gro_frags(struct napi_struct *napi) 4181 { 4182 struct sk_buff *skb = napi_frags_skb(napi); 4183 4184 if (!skb) 4185 return GRO_DROP; 4186 4187 trace_napi_gro_frags_entry(skb); 4188 4189 return napi_frags_finish(napi, skb, dev_gro_receive(napi, skb)); 4190 } 4191 EXPORT_SYMBOL(napi_gro_frags); 4192 4193 /* 4194 * net_rps_action_and_irq_enable sends any pending IPI's for rps. 4195 * Note: called with local irq disabled, but exits with local irq enabled. 4196 */ 4197 static void net_rps_action_and_irq_enable(struct softnet_data *sd) 4198 { 4199 #ifdef CONFIG_RPS 4200 struct softnet_data *remsd = sd->rps_ipi_list; 4201 4202 if (remsd) { 4203 sd->rps_ipi_list = NULL; 4204 4205 local_irq_enable(); 4206 4207 /* Send pending IPI's to kick RPS processing on remote cpus. */ 4208 while (remsd) { 4209 struct softnet_data *next = remsd->rps_ipi_next; 4210 4211 if (cpu_online(remsd->cpu)) 4212 smp_call_function_single_async(remsd->cpu, 4213 &remsd->csd); 4214 remsd = next; 4215 } 4216 } else 4217 #endif 4218 local_irq_enable(); 4219 } 4220 4221 static int process_backlog(struct napi_struct *napi, int quota) 4222 { 4223 int work = 0; 4224 struct softnet_data *sd = container_of(napi, struct softnet_data, backlog); 4225 4226 #ifdef CONFIG_RPS 4227 /* Check if we have pending ipi, its better to send them now, 4228 * not waiting net_rx_action() end. 4229 */ 4230 if (sd->rps_ipi_list) { 4231 local_irq_disable(); 4232 net_rps_action_and_irq_enable(sd); 4233 } 4234 #endif 4235 napi->weight = weight_p; 4236 local_irq_disable(); 4237 while (1) { 4238 struct sk_buff *skb; 4239 4240 while ((skb = __skb_dequeue(&sd->process_queue))) { 4241 local_irq_enable(); 4242 __netif_receive_skb(skb); 4243 local_irq_disable(); 4244 input_queue_head_incr(sd); 4245 if (++work >= quota) { 4246 local_irq_enable(); 4247 return work; 4248 } 4249 } 4250 4251 rps_lock(sd); 4252 if (skb_queue_empty(&sd->input_pkt_queue)) { 4253 /* 4254 * Inline a custom version of __napi_complete(). 4255 * only current cpu owns and manipulates this napi, 4256 * and NAPI_STATE_SCHED is the only possible flag set 4257 * on backlog. 4258 * We can use a plain write instead of clear_bit(), 4259 * and we dont need an smp_mb() memory barrier. 4260 */ 4261 list_del(&napi->poll_list); 4262 napi->state = 0; 4263 rps_unlock(sd); 4264 4265 break; 4266 } 4267 4268 skb_queue_splice_tail_init(&sd->input_pkt_queue, 4269 &sd->process_queue); 4270 rps_unlock(sd); 4271 } 4272 local_irq_enable(); 4273 4274 return work; 4275 } 4276 4277 /** 4278 * __napi_schedule - schedule for receive 4279 * @n: entry to schedule 4280 * 4281 * The entry's receive function will be scheduled to run 4282 */ 4283 void __napi_schedule(struct napi_struct *n) 4284 { 4285 unsigned long flags; 4286 4287 local_irq_save(flags); 4288 ____napi_schedule(&__get_cpu_var(softnet_data), n); 4289 local_irq_restore(flags); 4290 } 4291 EXPORT_SYMBOL(__napi_schedule); 4292 4293 void __napi_complete(struct napi_struct *n) 4294 { 4295 BUG_ON(!test_bit(NAPI_STATE_SCHED, &n->state)); 4296 BUG_ON(n->gro_list); 4297 4298 list_del(&n->poll_list); 4299 smp_mb__before_atomic(); 4300 clear_bit(NAPI_STATE_SCHED, &n->state); 4301 } 4302 EXPORT_SYMBOL(__napi_complete); 4303 4304 void napi_complete(struct napi_struct *n) 4305 { 4306 unsigned long flags; 4307 4308 /* 4309 * don't let napi dequeue from the cpu poll list 4310 * just in case its running on a different cpu 4311 */ 4312 if (unlikely(test_bit(NAPI_STATE_NPSVC, &n->state))) 4313 return; 4314 4315 napi_gro_flush(n, false); 4316 local_irq_save(flags); 4317 __napi_complete(n); 4318 local_irq_restore(flags); 4319 } 4320 EXPORT_SYMBOL(napi_complete); 4321 4322 /* must be called under rcu_read_lock(), as we dont take a reference */ 4323 struct napi_struct *napi_by_id(unsigned int napi_id) 4324 { 4325 unsigned int hash = napi_id % HASH_SIZE(napi_hash); 4326 struct napi_struct *napi; 4327 4328 hlist_for_each_entry_rcu(napi, &napi_hash[hash], napi_hash_node) 4329 if (napi->napi_id == napi_id) 4330 return napi; 4331 4332 return NULL; 4333 } 4334 EXPORT_SYMBOL_GPL(napi_by_id); 4335 4336 void napi_hash_add(struct napi_struct *napi) 4337 { 4338 if (!test_and_set_bit(NAPI_STATE_HASHED, &napi->state)) { 4339 4340 spin_lock(&napi_hash_lock); 4341 4342 /* 0 is not a valid id, we also skip an id that is taken 4343 * we expect both events to be extremely rare 4344 */ 4345 napi->napi_id = 0; 4346 while (!napi->napi_id) { 4347 napi->napi_id = ++napi_gen_id; 4348 if (napi_by_id(napi->napi_id)) 4349 napi->napi_id = 0; 4350 } 4351 4352 hlist_add_head_rcu(&napi->napi_hash_node, 4353 &napi_hash[napi->napi_id % HASH_SIZE(napi_hash)]); 4354 4355 spin_unlock(&napi_hash_lock); 4356 } 4357 } 4358 EXPORT_SYMBOL_GPL(napi_hash_add); 4359 4360 /* Warning : caller is responsible to make sure rcu grace period 4361 * is respected before freeing memory containing @napi 4362 */ 4363 void napi_hash_del(struct napi_struct *napi) 4364 { 4365 spin_lock(&napi_hash_lock); 4366 4367 if (test_and_clear_bit(NAPI_STATE_HASHED, &napi->state)) 4368 hlist_del_rcu(&napi->napi_hash_node); 4369 4370 spin_unlock(&napi_hash_lock); 4371 } 4372 EXPORT_SYMBOL_GPL(napi_hash_del); 4373 4374 void netif_napi_add(struct net_device *dev, struct napi_struct *napi, 4375 int (*poll)(struct napi_struct *, int), int weight) 4376 { 4377 INIT_LIST_HEAD(&napi->poll_list); 4378 napi->gro_count = 0; 4379 napi->gro_list = NULL; 4380 napi->skb = NULL; 4381 napi->poll = poll; 4382 if (weight > NAPI_POLL_WEIGHT) 4383 pr_err_once("netif_napi_add() called with weight %d on device %s\n", 4384 weight, dev->name); 4385 napi->weight = weight; 4386 list_add(&napi->dev_list, &dev->napi_list); 4387 napi->dev = dev; 4388 #ifdef CONFIG_NETPOLL 4389 spin_lock_init(&napi->poll_lock); 4390 napi->poll_owner = -1; 4391 #endif 4392 set_bit(NAPI_STATE_SCHED, &napi->state); 4393 } 4394 EXPORT_SYMBOL(netif_napi_add); 4395 4396 void netif_napi_del(struct napi_struct *napi) 4397 { 4398 list_del_init(&napi->dev_list); 4399 napi_free_frags(napi); 4400 4401 kfree_skb_list(napi->gro_list); 4402 napi->gro_list = NULL; 4403 napi->gro_count = 0; 4404 } 4405 EXPORT_SYMBOL(netif_napi_del); 4406 4407 static void net_rx_action(struct softirq_action *h) 4408 { 4409 struct softnet_data *sd = &__get_cpu_var(softnet_data); 4410 unsigned long time_limit = jiffies + 2; 4411 int budget = netdev_budget; 4412 void *have; 4413 4414 local_irq_disable(); 4415 4416 while (!list_empty(&sd->poll_list)) { 4417 struct napi_struct *n; 4418 int work, weight; 4419 4420 /* If softirq window is exhuasted then punt. 4421 * Allow this to run for 2 jiffies since which will allow 4422 * an average latency of 1.5/HZ. 4423 */ 4424 if (unlikely(budget <= 0 || time_after_eq(jiffies, time_limit))) 4425 goto softnet_break; 4426 4427 local_irq_enable(); 4428 4429 /* Even though interrupts have been re-enabled, this 4430 * access is safe because interrupts can only add new 4431 * entries to the tail of this list, and only ->poll() 4432 * calls can remove this head entry from the list. 4433 */ 4434 n = list_first_entry(&sd->poll_list, struct napi_struct, poll_list); 4435 4436 have = netpoll_poll_lock(n); 4437 4438 weight = n->weight; 4439 4440 /* This NAPI_STATE_SCHED test is for avoiding a race 4441 * with netpoll's poll_napi(). Only the entity which 4442 * obtains the lock and sees NAPI_STATE_SCHED set will 4443 * actually make the ->poll() call. Therefore we avoid 4444 * accidentally calling ->poll() when NAPI is not scheduled. 4445 */ 4446 work = 0; 4447 if (test_bit(NAPI_STATE_SCHED, &n->state)) { 4448 work = n->poll(n, weight); 4449 trace_napi_poll(n); 4450 } 4451 4452 WARN_ON_ONCE(work > weight); 4453 4454 budget -= work; 4455 4456 local_irq_disable(); 4457 4458 /* Drivers must not modify the NAPI state if they 4459 * consume the entire weight. In such cases this code 4460 * still "owns" the NAPI instance and therefore can 4461 * move the instance around on the list at-will. 4462 */ 4463 if (unlikely(work == weight)) { 4464 if (unlikely(napi_disable_pending(n))) { 4465 local_irq_enable(); 4466 napi_complete(n); 4467 local_irq_disable(); 4468 } else { 4469 if (n->gro_list) { 4470 /* flush too old packets 4471 * If HZ < 1000, flush all packets. 4472 */ 4473 local_irq_enable(); 4474 napi_gro_flush(n, HZ >= 1000); 4475 local_irq_disable(); 4476 } 4477 list_move_tail(&n->poll_list, &sd->poll_list); 4478 } 4479 } 4480 4481 netpoll_poll_unlock(have); 4482 } 4483 out: 4484 net_rps_action_and_irq_enable(sd); 4485 4486 #ifdef CONFIG_NET_DMA 4487 /* 4488 * There may not be any more sk_buffs coming right now, so push 4489 * any pending DMA copies to hardware 4490 */ 4491 dma_issue_pending_all(); 4492 #endif 4493 4494 return; 4495 4496 softnet_break: 4497 sd->time_squeeze++; 4498 __raise_softirq_irqoff(NET_RX_SOFTIRQ); 4499 goto out; 4500 } 4501 4502 struct netdev_adjacent { 4503 struct net_device *dev; 4504 4505 /* upper master flag, there can only be one master device per list */ 4506 bool master; 4507 4508 /* counter for the number of times this device was added to us */ 4509 u16 ref_nr; 4510 4511 /* private field for the users */ 4512 void *private; 4513 4514 struct list_head list; 4515 struct rcu_head rcu; 4516 }; 4517 4518 static struct netdev_adjacent *__netdev_find_adj(struct net_device *dev, 4519 struct net_device *adj_dev, 4520 struct list_head *adj_list) 4521 { 4522 struct netdev_adjacent *adj; 4523 4524 list_for_each_entry(adj, adj_list, list) { 4525 if (adj->dev == adj_dev) 4526 return adj; 4527 } 4528 return NULL; 4529 } 4530 4531 /** 4532 * netdev_has_upper_dev - Check if device is linked to an upper device 4533 * @dev: device 4534 * @upper_dev: upper device to check 4535 * 4536 * Find out if a device is linked to specified upper device and return true 4537 * in case it is. Note that this checks only immediate upper device, 4538 * not through a complete stack of devices. The caller must hold the RTNL lock. 4539 */ 4540 bool netdev_has_upper_dev(struct net_device *dev, 4541 struct net_device *upper_dev) 4542 { 4543 ASSERT_RTNL(); 4544 4545 return __netdev_find_adj(dev, upper_dev, &dev->all_adj_list.upper); 4546 } 4547 EXPORT_SYMBOL(netdev_has_upper_dev); 4548 4549 /** 4550 * netdev_has_any_upper_dev - Check if device is linked to some device 4551 * @dev: device 4552 * 4553 * Find out if a device is linked to an upper device and return true in case 4554 * it is. The caller must hold the RTNL lock. 4555 */ 4556 static bool netdev_has_any_upper_dev(struct net_device *dev) 4557 { 4558 ASSERT_RTNL(); 4559 4560 return !list_empty(&dev->all_adj_list.upper); 4561 } 4562 4563 /** 4564 * netdev_master_upper_dev_get - Get master upper device 4565 * @dev: device 4566 * 4567 * Find a master upper device and return pointer to it or NULL in case 4568 * it's not there. The caller must hold the RTNL lock. 4569 */ 4570 struct net_device *netdev_master_upper_dev_get(struct net_device *dev) 4571 { 4572 struct netdev_adjacent *upper; 4573 4574 ASSERT_RTNL(); 4575 4576 if (list_empty(&dev->adj_list.upper)) 4577 return NULL; 4578 4579 upper = list_first_entry(&dev->adj_list.upper, 4580 struct netdev_adjacent, list); 4581 if (likely(upper->master)) 4582 return upper->dev; 4583 return NULL; 4584 } 4585 EXPORT_SYMBOL(netdev_master_upper_dev_get); 4586 4587 void *netdev_adjacent_get_private(struct list_head *adj_list) 4588 { 4589 struct netdev_adjacent *adj; 4590 4591 adj = list_entry(adj_list, struct netdev_adjacent, list); 4592 4593 return adj->private; 4594 } 4595 EXPORT_SYMBOL(netdev_adjacent_get_private); 4596 4597 /** 4598 * netdev_upper_get_next_dev_rcu - Get the next dev from upper list 4599 * @dev: device 4600 * @iter: list_head ** of the current position 4601 * 4602 * Gets the next device from the dev's upper list, starting from iter 4603 * position. The caller must hold RCU read lock. 4604 */ 4605 struct net_device *netdev_upper_get_next_dev_rcu(struct net_device *dev, 4606 struct list_head **iter) 4607 { 4608 struct netdev_adjacent *upper; 4609 4610 WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held()); 4611 4612 upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list); 4613 4614 if (&upper->list == &dev->adj_list.upper) 4615 return NULL; 4616 4617 *iter = &upper->list; 4618 4619 return upper->dev; 4620 } 4621 EXPORT_SYMBOL(netdev_upper_get_next_dev_rcu); 4622 4623 /** 4624 * netdev_all_upper_get_next_dev_rcu - Get the next dev from upper list 4625 * @dev: device 4626 * @iter: list_head ** of the current position 4627 * 4628 * Gets the next device from the dev's upper list, starting from iter 4629 * position. The caller must hold RCU read lock. 4630 */ 4631 struct net_device *netdev_all_upper_get_next_dev_rcu(struct net_device *dev, 4632 struct list_head **iter) 4633 { 4634 struct netdev_adjacent *upper; 4635 4636 WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held()); 4637 4638 upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list); 4639 4640 if (&upper->list == &dev->all_adj_list.upper) 4641 return NULL; 4642 4643 *iter = &upper->list; 4644 4645 return upper->dev; 4646 } 4647 EXPORT_SYMBOL(netdev_all_upper_get_next_dev_rcu); 4648 4649 /** 4650 * netdev_lower_get_next_private - Get the next ->private from the 4651 * lower neighbour list 4652 * @dev: device 4653 * @iter: list_head ** of the current position 4654 * 4655 * Gets the next netdev_adjacent->private from the dev's lower neighbour 4656 * list, starting from iter position. The caller must hold either hold the 4657 * RTNL lock or its own locking that guarantees that the neighbour lower 4658 * list will remain unchainged. 4659 */ 4660 void *netdev_lower_get_next_private(struct net_device *dev, 4661 struct list_head **iter) 4662 { 4663 struct netdev_adjacent *lower; 4664 4665 lower = list_entry(*iter, struct netdev_adjacent, list); 4666 4667 if (&lower->list == &dev->adj_list.lower) 4668 return NULL; 4669 4670 *iter = lower->list.next; 4671 4672 return lower->private; 4673 } 4674 EXPORT_SYMBOL(netdev_lower_get_next_private); 4675 4676 /** 4677 * netdev_lower_get_next_private_rcu - Get the next ->private from the 4678 * lower neighbour list, RCU 4679 * variant 4680 * @dev: device 4681 * @iter: list_head ** of the current position 4682 * 4683 * Gets the next netdev_adjacent->private from the dev's lower neighbour 4684 * list, starting from iter position. The caller must hold RCU read lock. 4685 */ 4686 void *netdev_lower_get_next_private_rcu(struct net_device *dev, 4687 struct list_head **iter) 4688 { 4689 struct netdev_adjacent *lower; 4690 4691 WARN_ON_ONCE(!rcu_read_lock_held()); 4692 4693 lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list); 4694 4695 if (&lower->list == &dev->adj_list.lower) 4696 return NULL; 4697 4698 *iter = &lower->list; 4699 4700 return lower->private; 4701 } 4702 EXPORT_SYMBOL(netdev_lower_get_next_private_rcu); 4703 4704 /** 4705 * netdev_lower_get_next - Get the next device from the lower neighbour 4706 * list 4707 * @dev: device 4708 * @iter: list_head ** of the current position 4709 * 4710 * Gets the next netdev_adjacent from the dev's lower neighbour 4711 * list, starting from iter position. The caller must hold RTNL lock or 4712 * its own locking that guarantees that the neighbour lower 4713 * list will remain unchainged. 4714 */ 4715 void *netdev_lower_get_next(struct net_device *dev, struct list_head **iter) 4716 { 4717 struct netdev_adjacent *lower; 4718 4719 lower = list_entry((*iter)->next, struct netdev_adjacent, list); 4720 4721 if (&lower->list == &dev->adj_list.lower) 4722 return NULL; 4723 4724 *iter = &lower->list; 4725 4726 return lower->dev; 4727 } 4728 EXPORT_SYMBOL(netdev_lower_get_next); 4729 4730 /** 4731 * netdev_lower_get_first_private_rcu - Get the first ->private from the 4732 * lower neighbour list, RCU 4733 * variant 4734 * @dev: device 4735 * 4736 * Gets the first netdev_adjacent->private from the dev's lower neighbour 4737 * list. The caller must hold RCU read lock. 4738 */ 4739 void *netdev_lower_get_first_private_rcu(struct net_device *dev) 4740 { 4741 struct netdev_adjacent *lower; 4742 4743 lower = list_first_or_null_rcu(&dev->adj_list.lower, 4744 struct netdev_adjacent, list); 4745 if (lower) 4746 return lower->private; 4747 return NULL; 4748 } 4749 EXPORT_SYMBOL(netdev_lower_get_first_private_rcu); 4750 4751 /** 4752 * netdev_master_upper_dev_get_rcu - Get master upper device 4753 * @dev: device 4754 * 4755 * Find a master upper device and return pointer to it or NULL in case 4756 * it's not there. The caller must hold the RCU read lock. 4757 */ 4758 struct net_device *netdev_master_upper_dev_get_rcu(struct net_device *dev) 4759 { 4760 struct netdev_adjacent *upper; 4761 4762 upper = list_first_or_null_rcu(&dev->adj_list.upper, 4763 struct netdev_adjacent, list); 4764 if (upper && likely(upper->master)) 4765 return upper->dev; 4766 return NULL; 4767 } 4768 EXPORT_SYMBOL(netdev_master_upper_dev_get_rcu); 4769 4770 static int netdev_adjacent_sysfs_add(struct net_device *dev, 4771 struct net_device *adj_dev, 4772 struct list_head *dev_list) 4773 { 4774 char linkname[IFNAMSIZ+7]; 4775 sprintf(linkname, dev_list == &dev->adj_list.upper ? 4776 "upper_%s" : "lower_%s", adj_dev->name); 4777 return sysfs_create_link(&(dev->dev.kobj), &(adj_dev->dev.kobj), 4778 linkname); 4779 } 4780 static void netdev_adjacent_sysfs_del(struct net_device *dev, 4781 char *name, 4782 struct list_head *dev_list) 4783 { 4784 char linkname[IFNAMSIZ+7]; 4785 sprintf(linkname, dev_list == &dev->adj_list.upper ? 4786 "upper_%s" : "lower_%s", name); 4787 sysfs_remove_link(&(dev->dev.kobj), linkname); 4788 } 4789 4790 #define netdev_adjacent_is_neigh_list(dev, dev_list) \ 4791 (dev_list == &dev->adj_list.upper || \ 4792 dev_list == &dev->adj_list.lower) 4793 4794 static int __netdev_adjacent_dev_insert(struct net_device *dev, 4795 struct net_device *adj_dev, 4796 struct list_head *dev_list, 4797 void *private, bool master) 4798 { 4799 struct netdev_adjacent *adj; 4800 int ret; 4801 4802 adj = __netdev_find_adj(dev, adj_dev, dev_list); 4803 4804 if (adj) { 4805 adj->ref_nr++; 4806 return 0; 4807 } 4808 4809 adj = kmalloc(sizeof(*adj), GFP_KERNEL); 4810 if (!adj) 4811 return -ENOMEM; 4812 4813 adj->dev = adj_dev; 4814 adj->master = master; 4815 adj->ref_nr = 1; 4816 adj->private = private; 4817 dev_hold(adj_dev); 4818 4819 pr_debug("dev_hold for %s, because of link added from %s to %s\n", 4820 adj_dev->name, dev->name, adj_dev->name); 4821 4822 if (netdev_adjacent_is_neigh_list(dev, dev_list)) { 4823 ret = netdev_adjacent_sysfs_add(dev, adj_dev, dev_list); 4824 if (ret) 4825 goto free_adj; 4826 } 4827 4828 /* Ensure that master link is always the first item in list. */ 4829 if (master) { 4830 ret = sysfs_create_link(&(dev->dev.kobj), 4831 &(adj_dev->dev.kobj), "master"); 4832 if (ret) 4833 goto remove_symlinks; 4834 4835 list_add_rcu(&adj->list, dev_list); 4836 } else { 4837 list_add_tail_rcu(&adj->list, dev_list); 4838 } 4839 4840 return 0; 4841 4842 remove_symlinks: 4843 if (netdev_adjacent_is_neigh_list(dev, dev_list)) 4844 netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list); 4845 free_adj: 4846 kfree(adj); 4847 dev_put(adj_dev); 4848 4849 return ret; 4850 } 4851 4852 static void __netdev_adjacent_dev_remove(struct net_device *dev, 4853 struct net_device *adj_dev, 4854 struct list_head *dev_list) 4855 { 4856 struct netdev_adjacent *adj; 4857 4858 adj = __netdev_find_adj(dev, adj_dev, dev_list); 4859 4860 if (!adj) { 4861 pr_err("tried to remove device %s from %s\n", 4862 dev->name, adj_dev->name); 4863 BUG(); 4864 } 4865 4866 if (adj->ref_nr > 1) { 4867 pr_debug("%s to %s ref_nr-- = %d\n", dev->name, adj_dev->name, 4868 adj->ref_nr-1); 4869 adj->ref_nr--; 4870 return; 4871 } 4872 4873 if (adj->master) 4874 sysfs_remove_link(&(dev->dev.kobj), "master"); 4875 4876 if (netdev_adjacent_is_neigh_list(dev, dev_list)) 4877 netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list); 4878 4879 list_del_rcu(&adj->list); 4880 pr_debug("dev_put for %s, because link removed from %s to %s\n", 4881 adj_dev->name, dev->name, adj_dev->name); 4882 dev_put(adj_dev); 4883 kfree_rcu(adj, rcu); 4884 } 4885 4886 static int __netdev_adjacent_dev_link_lists(struct net_device *dev, 4887 struct net_device *upper_dev, 4888 struct list_head *up_list, 4889 struct list_head *down_list, 4890 void *private, bool master) 4891 { 4892 int ret; 4893 4894 ret = __netdev_adjacent_dev_insert(dev, upper_dev, up_list, private, 4895 master); 4896 if (ret) 4897 return ret; 4898 4899 ret = __netdev_adjacent_dev_insert(upper_dev, dev, down_list, private, 4900 false); 4901 if (ret) { 4902 __netdev_adjacent_dev_remove(dev, upper_dev, up_list); 4903 return ret; 4904 } 4905 4906 return 0; 4907 } 4908 4909 static int __netdev_adjacent_dev_link(struct net_device *dev, 4910 struct net_device *upper_dev) 4911 { 4912 return __netdev_adjacent_dev_link_lists(dev, upper_dev, 4913 &dev->all_adj_list.upper, 4914 &upper_dev->all_adj_list.lower, 4915 NULL, false); 4916 } 4917 4918 static void __netdev_adjacent_dev_unlink_lists(struct net_device *dev, 4919 struct net_device *upper_dev, 4920 struct list_head *up_list, 4921 struct list_head *down_list) 4922 { 4923 __netdev_adjacent_dev_remove(dev, upper_dev, up_list); 4924 __netdev_adjacent_dev_remove(upper_dev, dev, down_list); 4925 } 4926 4927 static void __netdev_adjacent_dev_unlink(struct net_device *dev, 4928 struct net_device *upper_dev) 4929 { 4930 __netdev_adjacent_dev_unlink_lists(dev, upper_dev, 4931 &dev->all_adj_list.upper, 4932 &upper_dev->all_adj_list.lower); 4933 } 4934 4935 static int __netdev_adjacent_dev_link_neighbour(struct net_device *dev, 4936 struct net_device *upper_dev, 4937 void *private, bool master) 4938 { 4939 int ret = __netdev_adjacent_dev_link(dev, upper_dev); 4940 4941 if (ret) 4942 return ret; 4943 4944 ret = __netdev_adjacent_dev_link_lists(dev, upper_dev, 4945 &dev->adj_list.upper, 4946 &upper_dev->adj_list.lower, 4947 private, master); 4948 if (ret) { 4949 __netdev_adjacent_dev_unlink(dev, upper_dev); 4950 return ret; 4951 } 4952 4953 return 0; 4954 } 4955 4956 static void __netdev_adjacent_dev_unlink_neighbour(struct net_device *dev, 4957 struct net_device *upper_dev) 4958 { 4959 __netdev_adjacent_dev_unlink(dev, upper_dev); 4960 __netdev_adjacent_dev_unlink_lists(dev, upper_dev, 4961 &dev->adj_list.upper, 4962 &upper_dev->adj_list.lower); 4963 } 4964 4965 static int __netdev_upper_dev_link(struct net_device *dev, 4966 struct net_device *upper_dev, bool master, 4967 void *private) 4968 { 4969 struct netdev_adjacent *i, *j, *to_i, *to_j; 4970 int ret = 0; 4971 4972 ASSERT_RTNL(); 4973 4974 if (dev == upper_dev) 4975 return -EBUSY; 4976 4977 /* To prevent loops, check if dev is not upper device to upper_dev. */ 4978 if (__netdev_find_adj(upper_dev, dev, &upper_dev->all_adj_list.upper)) 4979 return -EBUSY; 4980 4981 if (__netdev_find_adj(dev, upper_dev, &dev->all_adj_list.upper)) 4982 return -EEXIST; 4983 4984 if (master && netdev_master_upper_dev_get(dev)) 4985 return -EBUSY; 4986 4987 ret = __netdev_adjacent_dev_link_neighbour(dev, upper_dev, private, 4988 master); 4989 if (ret) 4990 return ret; 4991 4992 /* Now that we linked these devs, make all the upper_dev's 4993 * all_adj_list.upper visible to every dev's all_adj_list.lower an 4994 * versa, and don't forget the devices itself. All of these 4995 * links are non-neighbours. 4996 */ 4997 list_for_each_entry(i, &dev->all_adj_list.lower, list) { 4998 list_for_each_entry(j, &upper_dev->all_adj_list.upper, list) { 4999 pr_debug("Interlinking %s with %s, non-neighbour\n", 5000 i->dev->name, j->dev->name); 5001 ret = __netdev_adjacent_dev_link(i->dev, j->dev); 5002 if (ret) 5003 goto rollback_mesh; 5004 } 5005 } 5006 5007 /* add dev to every upper_dev's upper device */ 5008 list_for_each_entry(i, &upper_dev->all_adj_list.upper, list) { 5009 pr_debug("linking %s's upper device %s with %s\n", 5010 upper_dev->name, i->dev->name, dev->name); 5011 ret = __netdev_adjacent_dev_link(dev, i->dev); 5012 if (ret) 5013 goto rollback_upper_mesh; 5014 } 5015 5016 /* add upper_dev to every dev's lower device */ 5017 list_for_each_entry(i, &dev->all_adj_list.lower, list) { 5018 pr_debug("linking %s's lower device %s with %s\n", dev->name, 5019 i->dev->name, upper_dev->name); 5020 ret = __netdev_adjacent_dev_link(i->dev, upper_dev); 5021 if (ret) 5022 goto rollback_lower_mesh; 5023 } 5024 5025 call_netdevice_notifiers(NETDEV_CHANGEUPPER, dev); 5026 return 0; 5027 5028 rollback_lower_mesh: 5029 to_i = i; 5030 list_for_each_entry(i, &dev->all_adj_list.lower, list) { 5031 if (i == to_i) 5032 break; 5033 __netdev_adjacent_dev_unlink(i->dev, upper_dev); 5034 } 5035 5036 i = NULL; 5037 5038 rollback_upper_mesh: 5039 to_i = i; 5040 list_for_each_entry(i, &upper_dev->all_adj_list.upper, list) { 5041 if (i == to_i) 5042 break; 5043 __netdev_adjacent_dev_unlink(dev, i->dev); 5044 } 5045 5046 i = j = NULL; 5047 5048 rollback_mesh: 5049 to_i = i; 5050 to_j = j; 5051 list_for_each_entry(i, &dev->all_adj_list.lower, list) { 5052 list_for_each_entry(j, &upper_dev->all_adj_list.upper, list) { 5053 if (i == to_i && j == to_j) 5054 break; 5055 __netdev_adjacent_dev_unlink(i->dev, j->dev); 5056 } 5057 if (i == to_i) 5058 break; 5059 } 5060 5061 __netdev_adjacent_dev_unlink_neighbour(dev, upper_dev); 5062 5063 return ret; 5064 } 5065 5066 /** 5067 * netdev_upper_dev_link - Add a link to the upper device 5068 * @dev: device 5069 * @upper_dev: new upper device 5070 * 5071 * Adds a link to device which is upper to this one. The caller must hold 5072 * the RTNL lock. On a failure a negative errno code is returned. 5073 * On success the reference counts are adjusted and the function 5074 * returns zero. 5075 */ 5076 int netdev_upper_dev_link(struct net_device *dev, 5077 struct net_device *upper_dev) 5078 { 5079 return __netdev_upper_dev_link(dev, upper_dev, false, NULL); 5080 } 5081 EXPORT_SYMBOL(netdev_upper_dev_link); 5082 5083 /** 5084 * netdev_master_upper_dev_link - Add a master link to the upper device 5085 * @dev: device 5086 * @upper_dev: new upper device 5087 * 5088 * Adds a link to device which is upper to this one. In this case, only 5089 * one master upper device can be linked, although other non-master devices 5090 * might be linked as well. The caller must hold the RTNL lock. 5091 * On a failure a negative errno code is returned. On success the reference 5092 * counts are adjusted and the function returns zero. 5093 */ 5094 int netdev_master_upper_dev_link(struct net_device *dev, 5095 struct net_device *upper_dev) 5096 { 5097 return __netdev_upper_dev_link(dev, upper_dev, true, NULL); 5098 } 5099 EXPORT_SYMBOL(netdev_master_upper_dev_link); 5100 5101 int netdev_master_upper_dev_link_private(struct net_device *dev, 5102 struct net_device *upper_dev, 5103 void *private) 5104 { 5105 return __netdev_upper_dev_link(dev, upper_dev, true, private); 5106 } 5107 EXPORT_SYMBOL(netdev_master_upper_dev_link_private); 5108 5109 /** 5110 * netdev_upper_dev_unlink - Removes a link to upper device 5111 * @dev: device 5112 * @upper_dev: new upper device 5113 * 5114 * Removes a link to device which is upper to this one. The caller must hold 5115 * the RTNL lock. 5116 */ 5117 void netdev_upper_dev_unlink(struct net_device *dev, 5118 struct net_device *upper_dev) 5119 { 5120 struct netdev_adjacent *i, *j; 5121 ASSERT_RTNL(); 5122 5123 __netdev_adjacent_dev_unlink_neighbour(dev, upper_dev); 5124 5125 /* Here is the tricky part. We must remove all dev's lower 5126 * devices from all upper_dev's upper devices and vice 5127 * versa, to maintain the graph relationship. 5128 */ 5129 list_for_each_entry(i, &dev->all_adj_list.lower, list) 5130 list_for_each_entry(j, &upper_dev->all_adj_list.upper, list) 5131 __netdev_adjacent_dev_unlink(i->dev, j->dev); 5132 5133 /* remove also the devices itself from lower/upper device 5134 * list 5135 */ 5136 list_for_each_entry(i, &dev->all_adj_list.lower, list) 5137 __netdev_adjacent_dev_unlink(i->dev, upper_dev); 5138 5139 list_for_each_entry(i, &upper_dev->all_adj_list.upper, list) 5140 __netdev_adjacent_dev_unlink(dev, i->dev); 5141 5142 call_netdevice_notifiers(NETDEV_CHANGEUPPER, dev); 5143 } 5144 EXPORT_SYMBOL(netdev_upper_dev_unlink); 5145 5146 void netdev_adjacent_rename_links(struct net_device *dev, char *oldname) 5147 { 5148 struct netdev_adjacent *iter; 5149 5150 list_for_each_entry(iter, &dev->adj_list.upper, list) { 5151 netdev_adjacent_sysfs_del(iter->dev, oldname, 5152 &iter->dev->adj_list.lower); 5153 netdev_adjacent_sysfs_add(iter->dev, dev, 5154 &iter->dev->adj_list.lower); 5155 } 5156 5157 list_for_each_entry(iter, &dev->adj_list.lower, list) { 5158 netdev_adjacent_sysfs_del(iter->dev, oldname, 5159 &iter->dev->adj_list.upper); 5160 netdev_adjacent_sysfs_add(iter->dev, dev, 5161 &iter->dev->adj_list.upper); 5162 } 5163 } 5164 5165 void *netdev_lower_dev_get_private(struct net_device *dev, 5166 struct net_device *lower_dev) 5167 { 5168 struct netdev_adjacent *lower; 5169 5170 if (!lower_dev) 5171 return NULL; 5172 lower = __netdev_find_adj(dev, lower_dev, &dev->adj_list.lower); 5173 if (!lower) 5174 return NULL; 5175 5176 return lower->private; 5177 } 5178 EXPORT_SYMBOL(netdev_lower_dev_get_private); 5179 5180 5181 int dev_get_nest_level(struct net_device *dev, 5182 bool (*type_check)(struct net_device *dev)) 5183 { 5184 struct net_device *lower = NULL; 5185 struct list_head *iter; 5186 int max_nest = -1; 5187 int nest; 5188 5189 ASSERT_RTNL(); 5190 5191 netdev_for_each_lower_dev(dev, lower, iter) { 5192 nest = dev_get_nest_level(lower, type_check); 5193 if (max_nest < nest) 5194 max_nest = nest; 5195 } 5196 5197 if (type_check(dev)) 5198 max_nest++; 5199 5200 return max_nest; 5201 } 5202 EXPORT_SYMBOL(dev_get_nest_level); 5203 5204 static void dev_change_rx_flags(struct net_device *dev, int flags) 5205 { 5206 const struct net_device_ops *ops = dev->netdev_ops; 5207 5208 if (ops->ndo_change_rx_flags) 5209 ops->ndo_change_rx_flags(dev, flags); 5210 } 5211 5212 static int __dev_set_promiscuity(struct net_device *dev, int inc, bool notify) 5213 { 5214 unsigned int old_flags = dev->flags; 5215 kuid_t uid; 5216 kgid_t gid; 5217 5218 ASSERT_RTNL(); 5219 5220 dev->flags |= IFF_PROMISC; 5221 dev->promiscuity += inc; 5222 if (dev->promiscuity == 0) { 5223 /* 5224 * Avoid overflow. 5225 * If inc causes overflow, untouch promisc and return error. 5226 */ 5227 if (inc < 0) 5228 dev->flags &= ~IFF_PROMISC; 5229 else { 5230 dev->promiscuity -= inc; 5231 pr_warn("%s: promiscuity touches roof, set promiscuity failed. promiscuity feature of device might be broken.\n", 5232 dev->name); 5233 return -EOVERFLOW; 5234 } 5235 } 5236 if (dev->flags != old_flags) { 5237 pr_info("device %s %s promiscuous mode\n", 5238 dev->name, 5239 dev->flags & IFF_PROMISC ? "entered" : "left"); 5240 if (audit_enabled) { 5241 current_uid_gid(&uid, &gid); 5242 audit_log(current->audit_context, GFP_ATOMIC, 5243 AUDIT_ANOM_PROMISCUOUS, 5244 "dev=%s prom=%d old_prom=%d auid=%u uid=%u gid=%u ses=%u", 5245 dev->name, (dev->flags & IFF_PROMISC), 5246 (old_flags & IFF_PROMISC), 5247 from_kuid(&init_user_ns, audit_get_loginuid(current)), 5248 from_kuid(&init_user_ns, uid), 5249 from_kgid(&init_user_ns, gid), 5250 audit_get_sessionid(current)); 5251 } 5252 5253 dev_change_rx_flags(dev, IFF_PROMISC); 5254 } 5255 if (notify) 5256 __dev_notify_flags(dev, old_flags, IFF_PROMISC); 5257 return 0; 5258 } 5259 5260 /** 5261 * dev_set_promiscuity - update promiscuity count on a device 5262 * @dev: device 5263 * @inc: modifier 5264 * 5265 * Add or remove promiscuity from a device. While the count in the device 5266 * remains above zero the interface remains promiscuous. Once it hits zero 5267 * the device reverts back to normal filtering operation. A negative inc 5268 * value is used to drop promiscuity on the device. 5269 * Return 0 if successful or a negative errno code on error. 5270 */ 5271 int dev_set_promiscuity(struct net_device *dev, int inc) 5272 { 5273 unsigned int old_flags = dev->flags; 5274 int err; 5275 5276 err = __dev_set_promiscuity(dev, inc, true); 5277 if (err < 0) 5278 return err; 5279 if (dev->flags != old_flags) 5280 dev_set_rx_mode(dev); 5281 return err; 5282 } 5283 EXPORT_SYMBOL(dev_set_promiscuity); 5284 5285 static int __dev_set_allmulti(struct net_device *dev, int inc, bool notify) 5286 { 5287 unsigned int old_flags = dev->flags, old_gflags = dev->gflags; 5288 5289 ASSERT_RTNL(); 5290 5291 dev->flags |= IFF_ALLMULTI; 5292 dev->allmulti += inc; 5293 if (dev->allmulti == 0) { 5294 /* 5295 * Avoid overflow. 5296 * If inc causes overflow, untouch allmulti and return error. 5297 */ 5298 if (inc < 0) 5299 dev->flags &= ~IFF_ALLMULTI; 5300 else { 5301 dev->allmulti -= inc; 5302 pr_warn("%s: allmulti touches roof, set allmulti failed. allmulti feature of device might be broken.\n", 5303 dev->name); 5304 return -EOVERFLOW; 5305 } 5306 } 5307 if (dev->flags ^ old_flags) { 5308 dev_change_rx_flags(dev, IFF_ALLMULTI); 5309 dev_set_rx_mode(dev); 5310 if (notify) 5311 __dev_notify_flags(dev, old_flags, 5312 dev->gflags ^ old_gflags); 5313 } 5314 return 0; 5315 } 5316 5317 /** 5318 * dev_set_allmulti - update allmulti count on a device 5319 * @dev: device 5320 * @inc: modifier 5321 * 5322 * Add or remove reception of all multicast frames to a device. While the 5323 * count in the device remains above zero the interface remains listening 5324 * to all interfaces. Once it hits zero the device reverts back to normal 5325 * filtering operation. A negative @inc value is used to drop the counter 5326 * when releasing a resource needing all multicasts. 5327 * Return 0 if successful or a negative errno code on error. 5328 */ 5329 5330 int dev_set_allmulti(struct net_device *dev, int inc) 5331 { 5332 return __dev_set_allmulti(dev, inc, true); 5333 } 5334 EXPORT_SYMBOL(dev_set_allmulti); 5335 5336 /* 5337 * Upload unicast and multicast address lists to device and 5338 * configure RX filtering. When the device doesn't support unicast 5339 * filtering it is put in promiscuous mode while unicast addresses 5340 * are present. 5341 */ 5342 void __dev_set_rx_mode(struct net_device *dev) 5343 { 5344 const struct net_device_ops *ops = dev->netdev_ops; 5345 5346 /* dev_open will call this function so the list will stay sane. */ 5347 if (!(dev->flags&IFF_UP)) 5348 return; 5349 5350 if (!netif_device_present(dev)) 5351 return; 5352 5353 if (!(dev->priv_flags & IFF_UNICAST_FLT)) { 5354 /* Unicast addresses changes may only happen under the rtnl, 5355 * therefore calling __dev_set_promiscuity here is safe. 5356 */ 5357 if (!netdev_uc_empty(dev) && !dev->uc_promisc) { 5358 __dev_set_promiscuity(dev, 1, false); 5359 dev->uc_promisc = true; 5360 } else if (netdev_uc_empty(dev) && dev->uc_promisc) { 5361 __dev_set_promiscuity(dev, -1, false); 5362 dev->uc_promisc = false; 5363 } 5364 } 5365 5366 if (ops->ndo_set_rx_mode) 5367 ops->ndo_set_rx_mode(dev); 5368 } 5369 5370 void dev_set_rx_mode(struct net_device *dev) 5371 { 5372 netif_addr_lock_bh(dev); 5373 __dev_set_rx_mode(dev); 5374 netif_addr_unlock_bh(dev); 5375 } 5376 5377 /** 5378 * dev_get_flags - get flags reported to userspace 5379 * @dev: device 5380 * 5381 * Get the combination of flag bits exported through APIs to userspace. 5382 */ 5383 unsigned int dev_get_flags(const struct net_device *dev) 5384 { 5385 unsigned int flags; 5386 5387 flags = (dev->flags & ~(IFF_PROMISC | 5388 IFF_ALLMULTI | 5389 IFF_RUNNING | 5390 IFF_LOWER_UP | 5391 IFF_DORMANT)) | 5392 (dev->gflags & (IFF_PROMISC | 5393 IFF_ALLMULTI)); 5394 5395 if (netif_running(dev)) { 5396 if (netif_oper_up(dev)) 5397 flags |= IFF_RUNNING; 5398 if (netif_carrier_ok(dev)) 5399 flags |= IFF_LOWER_UP; 5400 if (netif_dormant(dev)) 5401 flags |= IFF_DORMANT; 5402 } 5403 5404 return flags; 5405 } 5406 EXPORT_SYMBOL(dev_get_flags); 5407 5408 int __dev_change_flags(struct net_device *dev, unsigned int flags) 5409 { 5410 unsigned int old_flags = dev->flags; 5411 int ret; 5412 5413 ASSERT_RTNL(); 5414 5415 /* 5416 * Set the flags on our device. 5417 */ 5418 5419 dev->flags = (flags & (IFF_DEBUG | IFF_NOTRAILERS | IFF_NOARP | 5420 IFF_DYNAMIC | IFF_MULTICAST | IFF_PORTSEL | 5421 IFF_AUTOMEDIA)) | 5422 (dev->flags & (IFF_UP | IFF_VOLATILE | IFF_PROMISC | 5423 IFF_ALLMULTI)); 5424 5425 /* 5426 * Load in the correct multicast list now the flags have changed. 5427 */ 5428 5429 if ((old_flags ^ flags) & IFF_MULTICAST) 5430 dev_change_rx_flags(dev, IFF_MULTICAST); 5431 5432 dev_set_rx_mode(dev); 5433 5434 /* 5435 * Have we downed the interface. We handle IFF_UP ourselves 5436 * according to user attempts to set it, rather than blindly 5437 * setting it. 5438 */ 5439 5440 ret = 0; 5441 if ((old_flags ^ flags) & IFF_UP) { /* Bit is different ? */ 5442 ret = ((old_flags & IFF_UP) ? __dev_close : __dev_open)(dev); 5443 5444 if (!ret) 5445 dev_set_rx_mode(dev); 5446 } 5447 5448 if ((flags ^ dev->gflags) & IFF_PROMISC) { 5449 int inc = (flags & IFF_PROMISC) ? 1 : -1; 5450 unsigned int old_flags = dev->flags; 5451 5452 dev->gflags ^= IFF_PROMISC; 5453 5454 if (__dev_set_promiscuity(dev, inc, false) >= 0) 5455 if (dev->flags != old_flags) 5456 dev_set_rx_mode(dev); 5457 } 5458 5459 /* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI 5460 is important. Some (broken) drivers set IFF_PROMISC, when 5461 IFF_ALLMULTI is requested not asking us and not reporting. 5462 */ 5463 if ((flags ^ dev->gflags) & IFF_ALLMULTI) { 5464 int inc = (flags & IFF_ALLMULTI) ? 1 : -1; 5465 5466 dev->gflags ^= IFF_ALLMULTI; 5467 __dev_set_allmulti(dev, inc, false); 5468 } 5469 5470 return ret; 5471 } 5472 5473 void __dev_notify_flags(struct net_device *dev, unsigned int old_flags, 5474 unsigned int gchanges) 5475 { 5476 unsigned int changes = dev->flags ^ old_flags; 5477 5478 if (gchanges) 5479 rtmsg_ifinfo(RTM_NEWLINK, dev, gchanges, GFP_ATOMIC); 5480 5481 if (changes & IFF_UP) { 5482 if (dev->flags & IFF_UP) 5483 call_netdevice_notifiers(NETDEV_UP, dev); 5484 else 5485 call_netdevice_notifiers(NETDEV_DOWN, dev); 5486 } 5487 5488 if (dev->flags & IFF_UP && 5489 (changes & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI | IFF_VOLATILE))) { 5490 struct netdev_notifier_change_info change_info; 5491 5492 change_info.flags_changed = changes; 5493 call_netdevice_notifiers_info(NETDEV_CHANGE, dev, 5494 &change_info.info); 5495 } 5496 } 5497 5498 /** 5499 * dev_change_flags - change device settings 5500 * @dev: device 5501 * @flags: device state flags 5502 * 5503 * Change settings on device based state flags. The flags are 5504 * in the userspace exported format. 5505 */ 5506 int dev_change_flags(struct net_device *dev, unsigned int flags) 5507 { 5508 int ret; 5509 unsigned int changes, old_flags = dev->flags, old_gflags = dev->gflags; 5510 5511 ret = __dev_change_flags(dev, flags); 5512 if (ret < 0) 5513 return ret; 5514 5515 changes = (old_flags ^ dev->flags) | (old_gflags ^ dev->gflags); 5516 __dev_notify_flags(dev, old_flags, changes); 5517 return ret; 5518 } 5519 EXPORT_SYMBOL(dev_change_flags); 5520 5521 static int __dev_set_mtu(struct net_device *dev, int new_mtu) 5522 { 5523 const struct net_device_ops *ops = dev->netdev_ops; 5524 5525 if (ops->ndo_change_mtu) 5526 return ops->ndo_change_mtu(dev, new_mtu); 5527 5528 dev->mtu = new_mtu; 5529 return 0; 5530 } 5531 5532 /** 5533 * dev_set_mtu - Change maximum transfer unit 5534 * @dev: device 5535 * @new_mtu: new transfer unit 5536 * 5537 * Change the maximum transfer size of the network device. 5538 */ 5539 int dev_set_mtu(struct net_device *dev, int new_mtu) 5540 { 5541 int err, orig_mtu; 5542 5543 if (new_mtu == dev->mtu) 5544 return 0; 5545 5546 /* MTU must be positive. */ 5547 if (new_mtu < 0) 5548 return -EINVAL; 5549 5550 if (!netif_device_present(dev)) 5551 return -ENODEV; 5552 5553 err = call_netdevice_notifiers(NETDEV_PRECHANGEMTU, dev); 5554 err = notifier_to_errno(err); 5555 if (err) 5556 return err; 5557 5558 orig_mtu = dev->mtu; 5559 err = __dev_set_mtu(dev, new_mtu); 5560 5561 if (!err) { 5562 err = call_netdevice_notifiers(NETDEV_CHANGEMTU, dev); 5563 err = notifier_to_errno(err); 5564 if (err) { 5565 /* setting mtu back and notifying everyone again, 5566 * so that they have a chance to revert changes. 5567 */ 5568 __dev_set_mtu(dev, orig_mtu); 5569 call_netdevice_notifiers(NETDEV_CHANGEMTU, dev); 5570 } 5571 } 5572 return err; 5573 } 5574 EXPORT_SYMBOL(dev_set_mtu); 5575 5576 /** 5577 * dev_set_group - Change group this device belongs to 5578 * @dev: device 5579 * @new_group: group this device should belong to 5580 */ 5581 void dev_set_group(struct net_device *dev, int new_group) 5582 { 5583 dev->group = new_group; 5584 } 5585 EXPORT_SYMBOL(dev_set_group); 5586 5587 /** 5588 * dev_set_mac_address - Change Media Access Control Address 5589 * @dev: device 5590 * @sa: new address 5591 * 5592 * Change the hardware (MAC) address of the device 5593 */ 5594 int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa) 5595 { 5596 const struct net_device_ops *ops = dev->netdev_ops; 5597 int err; 5598 5599 if (!ops->ndo_set_mac_address) 5600 return -EOPNOTSUPP; 5601 if (sa->sa_family != dev->type) 5602 return -EINVAL; 5603 if (!netif_device_present(dev)) 5604 return -ENODEV; 5605 err = ops->ndo_set_mac_address(dev, sa); 5606 if (err) 5607 return err; 5608 dev->addr_assign_type = NET_ADDR_SET; 5609 call_netdevice_notifiers(NETDEV_CHANGEADDR, dev); 5610 add_device_randomness(dev->dev_addr, dev->addr_len); 5611 return 0; 5612 } 5613 EXPORT_SYMBOL(dev_set_mac_address); 5614 5615 /** 5616 * dev_change_carrier - Change device carrier 5617 * @dev: device 5618 * @new_carrier: new value 5619 * 5620 * Change device carrier 5621 */ 5622 int dev_change_carrier(struct net_device *dev, bool new_carrier) 5623 { 5624 const struct net_device_ops *ops = dev->netdev_ops; 5625 5626 if (!ops->ndo_change_carrier) 5627 return -EOPNOTSUPP; 5628 if (!netif_device_present(dev)) 5629 return -ENODEV; 5630 return ops->ndo_change_carrier(dev, new_carrier); 5631 } 5632 EXPORT_SYMBOL(dev_change_carrier); 5633 5634 /** 5635 * dev_get_phys_port_id - Get device physical port ID 5636 * @dev: device 5637 * @ppid: port ID 5638 * 5639 * Get device physical port ID 5640 */ 5641 int dev_get_phys_port_id(struct net_device *dev, 5642 struct netdev_phys_port_id *ppid) 5643 { 5644 const struct net_device_ops *ops = dev->netdev_ops; 5645 5646 if (!ops->ndo_get_phys_port_id) 5647 return -EOPNOTSUPP; 5648 return ops->ndo_get_phys_port_id(dev, ppid); 5649 } 5650 EXPORT_SYMBOL(dev_get_phys_port_id); 5651 5652 /** 5653 * dev_new_index - allocate an ifindex 5654 * @net: the applicable net namespace 5655 * 5656 * Returns a suitable unique value for a new device interface 5657 * number. The caller must hold the rtnl semaphore or the 5658 * dev_base_lock to be sure it remains unique. 5659 */ 5660 static int dev_new_index(struct net *net) 5661 { 5662 int ifindex = net->ifindex; 5663 for (;;) { 5664 if (++ifindex <= 0) 5665 ifindex = 1; 5666 if (!__dev_get_by_index(net, ifindex)) 5667 return net->ifindex = ifindex; 5668 } 5669 } 5670 5671 /* Delayed registration/unregisteration */ 5672 static LIST_HEAD(net_todo_list); 5673 DECLARE_WAIT_QUEUE_HEAD(netdev_unregistering_wq); 5674 5675 static void net_set_todo(struct net_device *dev) 5676 { 5677 list_add_tail(&dev->todo_list, &net_todo_list); 5678 dev_net(dev)->dev_unreg_count++; 5679 } 5680 5681 static void rollback_registered_many(struct list_head *head) 5682 { 5683 struct net_device *dev, *tmp; 5684 LIST_HEAD(close_head); 5685 5686 BUG_ON(dev_boot_phase); 5687 ASSERT_RTNL(); 5688 5689 list_for_each_entry_safe(dev, tmp, head, unreg_list) { 5690 /* Some devices call without registering 5691 * for initialization unwind. Remove those 5692 * devices and proceed with the remaining. 5693 */ 5694 if (dev->reg_state == NETREG_UNINITIALIZED) { 5695 pr_debug("unregister_netdevice: device %s/%p never was registered\n", 5696 dev->name, dev); 5697 5698 WARN_ON(1); 5699 list_del(&dev->unreg_list); 5700 continue; 5701 } 5702 dev->dismantle = true; 5703 BUG_ON(dev->reg_state != NETREG_REGISTERED); 5704 } 5705 5706 /* If device is running, close it first. */ 5707 list_for_each_entry(dev, head, unreg_list) 5708 list_add_tail(&dev->close_list, &close_head); 5709 dev_close_many(&close_head); 5710 5711 list_for_each_entry(dev, head, unreg_list) { 5712 /* And unlink it from device chain. */ 5713 unlist_netdevice(dev); 5714 5715 dev->reg_state = NETREG_UNREGISTERING; 5716 } 5717 5718 synchronize_net(); 5719 5720 list_for_each_entry(dev, head, unreg_list) { 5721 /* Shutdown queueing discipline. */ 5722 dev_shutdown(dev); 5723 5724 5725 /* Notify protocols, that we are about to destroy 5726 this device. They should clean all the things. 5727 */ 5728 call_netdevice_notifiers(NETDEV_UNREGISTER, dev); 5729 5730 /* 5731 * Flush the unicast and multicast chains 5732 */ 5733 dev_uc_flush(dev); 5734 dev_mc_flush(dev); 5735 5736 if (dev->netdev_ops->ndo_uninit) 5737 dev->netdev_ops->ndo_uninit(dev); 5738 5739 if (!dev->rtnl_link_ops || 5740 dev->rtnl_link_state == RTNL_LINK_INITIALIZED) 5741 rtmsg_ifinfo(RTM_DELLINK, dev, ~0U, GFP_KERNEL); 5742 5743 /* Notifier chain MUST detach us all upper devices. */ 5744 WARN_ON(netdev_has_any_upper_dev(dev)); 5745 5746 /* Remove entries from kobject tree */ 5747 netdev_unregister_kobject(dev); 5748 #ifdef CONFIG_XPS 5749 /* Remove XPS queueing entries */ 5750 netif_reset_xps_queues_gt(dev, 0); 5751 #endif 5752 } 5753 5754 synchronize_net(); 5755 5756 list_for_each_entry(dev, head, unreg_list) 5757 dev_put(dev); 5758 } 5759 5760 static void rollback_registered(struct net_device *dev) 5761 { 5762 LIST_HEAD(single); 5763 5764 list_add(&dev->unreg_list, &single); 5765 rollback_registered_many(&single); 5766 list_del(&single); 5767 } 5768 5769 static netdev_features_t netdev_fix_features(struct net_device *dev, 5770 netdev_features_t features) 5771 { 5772 /* Fix illegal checksum combinations */ 5773 if ((features & NETIF_F_HW_CSUM) && 5774 (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) { 5775 netdev_warn(dev, "mixed HW and IP checksum settings.\n"); 5776 features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM); 5777 } 5778 5779 /* TSO requires that SG is present as well. */ 5780 if ((features & NETIF_F_ALL_TSO) && !(features & NETIF_F_SG)) { 5781 netdev_dbg(dev, "Dropping TSO features since no SG feature.\n"); 5782 features &= ~NETIF_F_ALL_TSO; 5783 } 5784 5785 if ((features & NETIF_F_TSO) && !(features & NETIF_F_HW_CSUM) && 5786 !(features & NETIF_F_IP_CSUM)) { 5787 netdev_dbg(dev, "Dropping TSO features since no CSUM feature.\n"); 5788 features &= ~NETIF_F_TSO; 5789 features &= ~NETIF_F_TSO_ECN; 5790 } 5791 5792 if ((features & NETIF_F_TSO6) && !(features & NETIF_F_HW_CSUM) && 5793 !(features & NETIF_F_IPV6_CSUM)) { 5794 netdev_dbg(dev, "Dropping TSO6 features since no CSUM feature.\n"); 5795 features &= ~NETIF_F_TSO6; 5796 } 5797 5798 /* TSO ECN requires that TSO is present as well. */ 5799 if ((features & NETIF_F_ALL_TSO) == NETIF_F_TSO_ECN) 5800 features &= ~NETIF_F_TSO_ECN; 5801 5802 /* Software GSO depends on SG. */ 5803 if ((features & NETIF_F_GSO) && !(features & NETIF_F_SG)) { 5804 netdev_dbg(dev, "Dropping NETIF_F_GSO since no SG feature.\n"); 5805 features &= ~NETIF_F_GSO; 5806 } 5807 5808 /* UFO needs SG and checksumming */ 5809 if (features & NETIF_F_UFO) { 5810 /* maybe split UFO into V4 and V6? */ 5811 if (!((features & NETIF_F_GEN_CSUM) || 5812 (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM)) 5813 == (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) { 5814 netdev_dbg(dev, 5815 "Dropping NETIF_F_UFO since no checksum offload features.\n"); 5816 features &= ~NETIF_F_UFO; 5817 } 5818 5819 if (!(features & NETIF_F_SG)) { 5820 netdev_dbg(dev, 5821 "Dropping NETIF_F_UFO since no NETIF_F_SG feature.\n"); 5822 features &= ~NETIF_F_UFO; 5823 } 5824 } 5825 5826 #ifdef CONFIG_NET_RX_BUSY_POLL 5827 if (dev->netdev_ops->ndo_busy_poll) 5828 features |= NETIF_F_BUSY_POLL; 5829 else 5830 #endif 5831 features &= ~NETIF_F_BUSY_POLL; 5832 5833 return features; 5834 } 5835 5836 int __netdev_update_features(struct net_device *dev) 5837 { 5838 netdev_features_t features; 5839 int err = 0; 5840 5841 ASSERT_RTNL(); 5842 5843 features = netdev_get_wanted_features(dev); 5844 5845 if (dev->netdev_ops->ndo_fix_features) 5846 features = dev->netdev_ops->ndo_fix_features(dev, features); 5847 5848 /* driver might be less strict about feature dependencies */ 5849 features = netdev_fix_features(dev, features); 5850 5851 if (dev->features == features) 5852 return 0; 5853 5854 netdev_dbg(dev, "Features changed: %pNF -> %pNF\n", 5855 &dev->features, &features); 5856 5857 if (dev->netdev_ops->ndo_set_features) 5858 err = dev->netdev_ops->ndo_set_features(dev, features); 5859 5860 if (unlikely(err < 0)) { 5861 netdev_err(dev, 5862 "set_features() failed (%d); wanted %pNF, left %pNF\n", 5863 err, &features, &dev->features); 5864 return -1; 5865 } 5866 5867 if (!err) 5868 dev->features = features; 5869 5870 return 1; 5871 } 5872 5873 /** 5874 * netdev_update_features - recalculate device features 5875 * @dev: the device to check 5876 * 5877 * Recalculate dev->features set and send notifications if it 5878 * has changed. Should be called after driver or hardware dependent 5879 * conditions might have changed that influence the features. 5880 */ 5881 void netdev_update_features(struct net_device *dev) 5882 { 5883 if (__netdev_update_features(dev)) 5884 netdev_features_change(dev); 5885 } 5886 EXPORT_SYMBOL(netdev_update_features); 5887 5888 /** 5889 * netdev_change_features - recalculate device features 5890 * @dev: the device to check 5891 * 5892 * Recalculate dev->features set and send notifications even 5893 * if they have not changed. Should be called instead of 5894 * netdev_update_features() if also dev->vlan_features might 5895 * have changed to allow the changes to be propagated to stacked 5896 * VLAN devices. 5897 */ 5898 void netdev_change_features(struct net_device *dev) 5899 { 5900 __netdev_update_features(dev); 5901 netdev_features_change(dev); 5902 } 5903 EXPORT_SYMBOL(netdev_change_features); 5904 5905 /** 5906 * netif_stacked_transfer_operstate - transfer operstate 5907 * @rootdev: the root or lower level device to transfer state from 5908 * @dev: the device to transfer operstate to 5909 * 5910 * Transfer operational state from root to device. This is normally 5911 * called when a stacking relationship exists between the root 5912 * device and the device(a leaf device). 5913 */ 5914 void netif_stacked_transfer_operstate(const struct net_device *rootdev, 5915 struct net_device *dev) 5916 { 5917 if (rootdev->operstate == IF_OPER_DORMANT) 5918 netif_dormant_on(dev); 5919 else 5920 netif_dormant_off(dev); 5921 5922 if (netif_carrier_ok(rootdev)) { 5923 if (!netif_carrier_ok(dev)) 5924 netif_carrier_on(dev); 5925 } else { 5926 if (netif_carrier_ok(dev)) 5927 netif_carrier_off(dev); 5928 } 5929 } 5930 EXPORT_SYMBOL(netif_stacked_transfer_operstate); 5931 5932 #ifdef CONFIG_SYSFS 5933 static int netif_alloc_rx_queues(struct net_device *dev) 5934 { 5935 unsigned int i, count = dev->num_rx_queues; 5936 struct netdev_rx_queue *rx; 5937 5938 BUG_ON(count < 1); 5939 5940 rx = kcalloc(count, sizeof(struct netdev_rx_queue), GFP_KERNEL); 5941 if (!rx) 5942 return -ENOMEM; 5943 5944 dev->_rx = rx; 5945 5946 for (i = 0; i < count; i++) 5947 rx[i].dev = dev; 5948 return 0; 5949 } 5950 #endif 5951 5952 static void netdev_init_one_queue(struct net_device *dev, 5953 struct netdev_queue *queue, void *_unused) 5954 { 5955 /* Initialize queue lock */ 5956 spin_lock_init(&queue->_xmit_lock); 5957 netdev_set_xmit_lockdep_class(&queue->_xmit_lock, dev->type); 5958 queue->xmit_lock_owner = -1; 5959 netdev_queue_numa_node_write(queue, NUMA_NO_NODE); 5960 queue->dev = dev; 5961 #ifdef CONFIG_BQL 5962 dql_init(&queue->dql, HZ); 5963 #endif 5964 } 5965 5966 static void netif_free_tx_queues(struct net_device *dev) 5967 { 5968 kvfree(dev->_tx); 5969 } 5970 5971 static int netif_alloc_netdev_queues(struct net_device *dev) 5972 { 5973 unsigned int count = dev->num_tx_queues; 5974 struct netdev_queue *tx; 5975 size_t sz = count * sizeof(*tx); 5976 5977 BUG_ON(count < 1 || count > 0xffff); 5978 5979 tx = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT); 5980 if (!tx) { 5981 tx = vzalloc(sz); 5982 if (!tx) 5983 return -ENOMEM; 5984 } 5985 dev->_tx = tx; 5986 5987 netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL); 5988 spin_lock_init(&dev->tx_global_lock); 5989 5990 return 0; 5991 } 5992 5993 /** 5994 * register_netdevice - register a network device 5995 * @dev: device to register 5996 * 5997 * Take a completed network device structure and add it to the kernel 5998 * interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier 5999 * chain. 0 is returned on success. A negative errno code is returned 6000 * on a failure to set up the device, or if the name is a duplicate. 6001 * 6002 * Callers must hold the rtnl semaphore. You may want 6003 * register_netdev() instead of this. 6004 * 6005 * BUGS: 6006 * The locking appears insufficient to guarantee two parallel registers 6007 * will not get the same name. 6008 */ 6009 6010 int register_netdevice(struct net_device *dev) 6011 { 6012 int ret; 6013 struct net *net = dev_net(dev); 6014 6015 BUG_ON(dev_boot_phase); 6016 ASSERT_RTNL(); 6017 6018 might_sleep(); 6019 6020 /* When net_device's are persistent, this will be fatal. */ 6021 BUG_ON(dev->reg_state != NETREG_UNINITIALIZED); 6022 BUG_ON(!net); 6023 6024 spin_lock_init(&dev->addr_list_lock); 6025 netdev_set_addr_lockdep_class(dev); 6026 6027 dev->iflink = -1; 6028 6029 ret = dev_get_valid_name(net, dev, dev->name); 6030 if (ret < 0) 6031 goto out; 6032 6033 /* Init, if this function is available */ 6034 if (dev->netdev_ops->ndo_init) { 6035 ret = dev->netdev_ops->ndo_init(dev); 6036 if (ret) { 6037 if (ret > 0) 6038 ret = -EIO; 6039 goto out; 6040 } 6041 } 6042 6043 if (((dev->hw_features | dev->features) & 6044 NETIF_F_HW_VLAN_CTAG_FILTER) && 6045 (!dev->netdev_ops->ndo_vlan_rx_add_vid || 6046 !dev->netdev_ops->ndo_vlan_rx_kill_vid)) { 6047 netdev_WARN(dev, "Buggy VLAN acceleration in driver!\n"); 6048 ret = -EINVAL; 6049 goto err_uninit; 6050 } 6051 6052 ret = -EBUSY; 6053 if (!dev->ifindex) 6054 dev->ifindex = dev_new_index(net); 6055 else if (__dev_get_by_index(net, dev->ifindex)) 6056 goto err_uninit; 6057 6058 if (dev->iflink == -1) 6059 dev->iflink = dev->ifindex; 6060 6061 /* Transfer changeable features to wanted_features and enable 6062 * software offloads (GSO and GRO). 6063 */ 6064 dev->hw_features |= NETIF_F_SOFT_FEATURES; 6065 dev->features |= NETIF_F_SOFT_FEATURES; 6066 dev->wanted_features = dev->features & dev->hw_features; 6067 6068 if (!(dev->flags & IFF_LOOPBACK)) { 6069 dev->hw_features |= NETIF_F_NOCACHE_COPY; 6070 } 6071 6072 /* Make NETIF_F_HIGHDMA inheritable to VLAN devices. 6073 */ 6074 dev->vlan_features |= NETIF_F_HIGHDMA; 6075 6076 /* Make NETIF_F_SG inheritable to tunnel devices. 6077 */ 6078 dev->hw_enc_features |= NETIF_F_SG; 6079 6080 /* Make NETIF_F_SG inheritable to MPLS. 6081 */ 6082 dev->mpls_features |= NETIF_F_SG; 6083 6084 ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev); 6085 ret = notifier_to_errno(ret); 6086 if (ret) 6087 goto err_uninit; 6088 6089 ret = netdev_register_kobject(dev); 6090 if (ret) 6091 goto err_uninit; 6092 dev->reg_state = NETREG_REGISTERED; 6093 6094 __netdev_update_features(dev); 6095 6096 /* 6097 * Default initial state at registry is that the 6098 * device is present. 6099 */ 6100 6101 set_bit(__LINK_STATE_PRESENT, &dev->state); 6102 6103 linkwatch_init_dev(dev); 6104 6105 dev_init_scheduler(dev); 6106 dev_hold(dev); 6107 list_netdevice(dev); 6108 add_device_randomness(dev->dev_addr, dev->addr_len); 6109 6110 /* If the device has permanent device address, driver should 6111 * set dev_addr and also addr_assign_type should be set to 6112 * NET_ADDR_PERM (default value). 6113 */ 6114 if (dev->addr_assign_type == NET_ADDR_PERM) 6115 memcpy(dev->perm_addr, dev->dev_addr, dev->addr_len); 6116 6117 /* Notify protocols, that a new device appeared. */ 6118 ret = call_netdevice_notifiers(NETDEV_REGISTER, dev); 6119 ret = notifier_to_errno(ret); 6120 if (ret) { 6121 rollback_registered(dev); 6122 dev->reg_state = NETREG_UNREGISTERED; 6123 } 6124 /* 6125 * Prevent userspace races by waiting until the network 6126 * device is fully setup before sending notifications. 6127 */ 6128 if (!dev->rtnl_link_ops || 6129 dev->rtnl_link_state == RTNL_LINK_INITIALIZED) 6130 rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL); 6131 6132 out: 6133 return ret; 6134 6135 err_uninit: 6136 if (dev->netdev_ops->ndo_uninit) 6137 dev->netdev_ops->ndo_uninit(dev); 6138 goto out; 6139 } 6140 EXPORT_SYMBOL(register_netdevice); 6141 6142 /** 6143 * init_dummy_netdev - init a dummy network device for NAPI 6144 * @dev: device to init 6145 * 6146 * This takes a network device structure and initialize the minimum 6147 * amount of fields so it can be used to schedule NAPI polls without 6148 * registering a full blown interface. This is to be used by drivers 6149 * that need to tie several hardware interfaces to a single NAPI 6150 * poll scheduler due to HW limitations. 6151 */ 6152 int init_dummy_netdev(struct net_device *dev) 6153 { 6154 /* Clear everything. Note we don't initialize spinlocks 6155 * are they aren't supposed to be taken by any of the 6156 * NAPI code and this dummy netdev is supposed to be 6157 * only ever used for NAPI polls 6158 */ 6159 memset(dev, 0, sizeof(struct net_device)); 6160 6161 /* make sure we BUG if trying to hit standard 6162 * register/unregister code path 6163 */ 6164 dev->reg_state = NETREG_DUMMY; 6165 6166 /* NAPI wants this */ 6167 INIT_LIST_HEAD(&dev->napi_list); 6168 6169 /* a dummy interface is started by default */ 6170 set_bit(__LINK_STATE_PRESENT, &dev->state); 6171 set_bit(__LINK_STATE_START, &dev->state); 6172 6173 /* Note : We dont allocate pcpu_refcnt for dummy devices, 6174 * because users of this 'device' dont need to change 6175 * its refcount. 6176 */ 6177 6178 return 0; 6179 } 6180 EXPORT_SYMBOL_GPL(init_dummy_netdev); 6181 6182 6183 /** 6184 * register_netdev - register a network device 6185 * @dev: device to register 6186 * 6187 * Take a completed network device structure and add it to the kernel 6188 * interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier 6189 * chain. 0 is returned on success. A negative errno code is returned 6190 * on a failure to set up the device, or if the name is a duplicate. 6191 * 6192 * This is a wrapper around register_netdevice that takes the rtnl semaphore 6193 * and expands the device name if you passed a format string to 6194 * alloc_netdev. 6195 */ 6196 int register_netdev(struct net_device *dev) 6197 { 6198 int err; 6199 6200 rtnl_lock(); 6201 err = register_netdevice(dev); 6202 rtnl_unlock(); 6203 return err; 6204 } 6205 EXPORT_SYMBOL(register_netdev); 6206 6207 int netdev_refcnt_read(const struct net_device *dev) 6208 { 6209 int i, refcnt = 0; 6210 6211 for_each_possible_cpu(i) 6212 refcnt += *per_cpu_ptr(dev->pcpu_refcnt, i); 6213 return refcnt; 6214 } 6215 EXPORT_SYMBOL(netdev_refcnt_read); 6216 6217 /** 6218 * netdev_wait_allrefs - wait until all references are gone. 6219 * @dev: target net_device 6220 * 6221 * This is called when unregistering network devices. 6222 * 6223 * Any protocol or device that holds a reference should register 6224 * for netdevice notification, and cleanup and put back the 6225 * reference if they receive an UNREGISTER event. 6226 * We can get stuck here if buggy protocols don't correctly 6227 * call dev_put. 6228 */ 6229 static void netdev_wait_allrefs(struct net_device *dev) 6230 { 6231 unsigned long rebroadcast_time, warning_time; 6232 int refcnt; 6233 6234 linkwatch_forget_dev(dev); 6235 6236 rebroadcast_time = warning_time = jiffies; 6237 refcnt = netdev_refcnt_read(dev); 6238 6239 while (refcnt != 0) { 6240 if (time_after(jiffies, rebroadcast_time + 1 * HZ)) { 6241 rtnl_lock(); 6242 6243 /* Rebroadcast unregister notification */ 6244 call_netdevice_notifiers(NETDEV_UNREGISTER, dev); 6245 6246 __rtnl_unlock(); 6247 rcu_barrier(); 6248 rtnl_lock(); 6249 6250 call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev); 6251 if (test_bit(__LINK_STATE_LINKWATCH_PENDING, 6252 &dev->state)) { 6253 /* We must not have linkwatch events 6254 * pending on unregister. If this 6255 * happens, we simply run the queue 6256 * unscheduled, resulting in a noop 6257 * for this device. 6258 */ 6259 linkwatch_run_queue(); 6260 } 6261 6262 __rtnl_unlock(); 6263 6264 rebroadcast_time = jiffies; 6265 } 6266 6267 msleep(250); 6268 6269 refcnt = netdev_refcnt_read(dev); 6270 6271 if (time_after(jiffies, warning_time + 10 * HZ)) { 6272 pr_emerg("unregister_netdevice: waiting for %s to become free. Usage count = %d\n", 6273 dev->name, refcnt); 6274 warning_time = jiffies; 6275 } 6276 } 6277 } 6278 6279 /* The sequence is: 6280 * 6281 * rtnl_lock(); 6282 * ... 6283 * register_netdevice(x1); 6284 * register_netdevice(x2); 6285 * ... 6286 * unregister_netdevice(y1); 6287 * unregister_netdevice(y2); 6288 * ... 6289 * rtnl_unlock(); 6290 * free_netdev(y1); 6291 * free_netdev(y2); 6292 * 6293 * We are invoked by rtnl_unlock(). 6294 * This allows us to deal with problems: 6295 * 1) We can delete sysfs objects which invoke hotplug 6296 * without deadlocking with linkwatch via keventd. 6297 * 2) Since we run with the RTNL semaphore not held, we can sleep 6298 * safely in order to wait for the netdev refcnt to drop to zero. 6299 * 6300 * We must not return until all unregister events added during 6301 * the interval the lock was held have been completed. 6302 */ 6303 void netdev_run_todo(void) 6304 { 6305 struct list_head list; 6306 6307 /* Snapshot list, allow later requests */ 6308 list_replace_init(&net_todo_list, &list); 6309 6310 __rtnl_unlock(); 6311 6312 6313 /* Wait for rcu callbacks to finish before next phase */ 6314 if (!list_empty(&list)) 6315 rcu_barrier(); 6316 6317 while (!list_empty(&list)) { 6318 struct net_device *dev 6319 = list_first_entry(&list, struct net_device, todo_list); 6320 list_del(&dev->todo_list); 6321 6322 rtnl_lock(); 6323 call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev); 6324 __rtnl_unlock(); 6325 6326 if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) { 6327 pr_err("network todo '%s' but state %d\n", 6328 dev->name, dev->reg_state); 6329 dump_stack(); 6330 continue; 6331 } 6332 6333 dev->reg_state = NETREG_UNREGISTERED; 6334 6335 on_each_cpu(flush_backlog, dev, 1); 6336 6337 netdev_wait_allrefs(dev); 6338 6339 /* paranoia */ 6340 BUG_ON(netdev_refcnt_read(dev)); 6341 WARN_ON(rcu_access_pointer(dev->ip_ptr)); 6342 WARN_ON(rcu_access_pointer(dev->ip6_ptr)); 6343 WARN_ON(dev->dn_ptr); 6344 6345 if (dev->destructor) 6346 dev->destructor(dev); 6347 6348 /* Report a network device has been unregistered */ 6349 rtnl_lock(); 6350 dev_net(dev)->dev_unreg_count--; 6351 __rtnl_unlock(); 6352 wake_up(&netdev_unregistering_wq); 6353 6354 /* Free network device */ 6355 kobject_put(&dev->dev.kobj); 6356 } 6357 } 6358 6359 /* Convert net_device_stats to rtnl_link_stats64. They have the same 6360 * fields in the same order, with only the type differing. 6361 */ 6362 void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64, 6363 const struct net_device_stats *netdev_stats) 6364 { 6365 #if BITS_PER_LONG == 64 6366 BUILD_BUG_ON(sizeof(*stats64) != sizeof(*netdev_stats)); 6367 memcpy(stats64, netdev_stats, sizeof(*stats64)); 6368 #else 6369 size_t i, n = sizeof(*stats64) / sizeof(u64); 6370 const unsigned long *src = (const unsigned long *)netdev_stats; 6371 u64 *dst = (u64 *)stats64; 6372 6373 BUILD_BUG_ON(sizeof(*netdev_stats) / sizeof(unsigned long) != 6374 sizeof(*stats64) / sizeof(u64)); 6375 for (i = 0; i < n; i++) 6376 dst[i] = src[i]; 6377 #endif 6378 } 6379 EXPORT_SYMBOL(netdev_stats_to_stats64); 6380 6381 /** 6382 * dev_get_stats - get network device statistics 6383 * @dev: device to get statistics from 6384 * @storage: place to store stats 6385 * 6386 * Get network statistics from device. Return @storage. 6387 * The device driver may provide its own method by setting 6388 * dev->netdev_ops->get_stats64 or dev->netdev_ops->get_stats; 6389 * otherwise the internal statistics structure is used. 6390 */ 6391 struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev, 6392 struct rtnl_link_stats64 *storage) 6393 { 6394 const struct net_device_ops *ops = dev->netdev_ops; 6395 6396 if (ops->ndo_get_stats64) { 6397 memset(storage, 0, sizeof(*storage)); 6398 ops->ndo_get_stats64(dev, storage); 6399 } else if (ops->ndo_get_stats) { 6400 netdev_stats_to_stats64(storage, ops->ndo_get_stats(dev)); 6401 } else { 6402 netdev_stats_to_stats64(storage, &dev->stats); 6403 } 6404 storage->rx_dropped += atomic_long_read(&dev->rx_dropped); 6405 storage->tx_dropped += atomic_long_read(&dev->tx_dropped); 6406 return storage; 6407 } 6408 EXPORT_SYMBOL(dev_get_stats); 6409 6410 struct netdev_queue *dev_ingress_queue_create(struct net_device *dev) 6411 { 6412 struct netdev_queue *queue = dev_ingress_queue(dev); 6413 6414 #ifdef CONFIG_NET_CLS_ACT 6415 if (queue) 6416 return queue; 6417 queue = kzalloc(sizeof(*queue), GFP_KERNEL); 6418 if (!queue) 6419 return NULL; 6420 netdev_init_one_queue(dev, queue, NULL); 6421 queue->qdisc = &noop_qdisc; 6422 queue->qdisc_sleeping = &noop_qdisc; 6423 rcu_assign_pointer(dev->ingress_queue, queue); 6424 #endif 6425 return queue; 6426 } 6427 6428 static const struct ethtool_ops default_ethtool_ops; 6429 6430 void netdev_set_default_ethtool_ops(struct net_device *dev, 6431 const struct ethtool_ops *ops) 6432 { 6433 if (dev->ethtool_ops == &default_ethtool_ops) 6434 dev->ethtool_ops = ops; 6435 } 6436 EXPORT_SYMBOL_GPL(netdev_set_default_ethtool_ops); 6437 6438 void netdev_freemem(struct net_device *dev) 6439 { 6440 char *addr = (char *)dev - dev->padded; 6441 6442 kvfree(addr); 6443 } 6444 6445 /** 6446 * alloc_netdev_mqs - allocate network device 6447 * @sizeof_priv: size of private data to allocate space for 6448 * @name: device name format string 6449 * @setup: callback to initialize device 6450 * @txqs: the number of TX subqueues to allocate 6451 * @rxqs: the number of RX subqueues to allocate 6452 * 6453 * Allocates a struct net_device with private data area for driver use 6454 * and performs basic initialization. Also allocates subqueue structs 6455 * for each queue on the device. 6456 */ 6457 struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name, 6458 void (*setup)(struct net_device *), 6459 unsigned int txqs, unsigned int rxqs) 6460 { 6461 struct net_device *dev; 6462 size_t alloc_size; 6463 struct net_device *p; 6464 6465 BUG_ON(strlen(name) >= sizeof(dev->name)); 6466 6467 if (txqs < 1) { 6468 pr_err("alloc_netdev: Unable to allocate device with zero queues\n"); 6469 return NULL; 6470 } 6471 6472 #ifdef CONFIG_SYSFS 6473 if (rxqs < 1) { 6474 pr_err("alloc_netdev: Unable to allocate device with zero RX queues\n"); 6475 return NULL; 6476 } 6477 #endif 6478 6479 alloc_size = sizeof(struct net_device); 6480 if (sizeof_priv) { 6481 /* ensure 32-byte alignment of private area */ 6482 alloc_size = ALIGN(alloc_size, NETDEV_ALIGN); 6483 alloc_size += sizeof_priv; 6484 } 6485 /* ensure 32-byte alignment of whole construct */ 6486 alloc_size += NETDEV_ALIGN - 1; 6487 6488 p = kzalloc(alloc_size, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT); 6489 if (!p) 6490 p = vzalloc(alloc_size); 6491 if (!p) 6492 return NULL; 6493 6494 dev = PTR_ALIGN(p, NETDEV_ALIGN); 6495 dev->padded = (char *)dev - (char *)p; 6496 6497 dev->pcpu_refcnt = alloc_percpu(int); 6498 if (!dev->pcpu_refcnt) 6499 goto free_dev; 6500 6501 if (dev_addr_init(dev)) 6502 goto free_pcpu; 6503 6504 dev_mc_init(dev); 6505 dev_uc_init(dev); 6506 6507 dev_net_set(dev, &init_net); 6508 6509 dev->gso_max_size = GSO_MAX_SIZE; 6510 dev->gso_max_segs = GSO_MAX_SEGS; 6511 6512 INIT_LIST_HEAD(&dev->napi_list); 6513 INIT_LIST_HEAD(&dev->unreg_list); 6514 INIT_LIST_HEAD(&dev->close_list); 6515 INIT_LIST_HEAD(&dev->link_watch_list); 6516 INIT_LIST_HEAD(&dev->adj_list.upper); 6517 INIT_LIST_HEAD(&dev->adj_list.lower); 6518 INIT_LIST_HEAD(&dev->all_adj_list.upper); 6519 INIT_LIST_HEAD(&dev->all_adj_list.lower); 6520 dev->priv_flags = IFF_XMIT_DST_RELEASE; 6521 setup(dev); 6522 6523 dev->num_tx_queues = txqs; 6524 dev->real_num_tx_queues = txqs; 6525 if (netif_alloc_netdev_queues(dev)) 6526 goto free_all; 6527 6528 #ifdef CONFIG_SYSFS 6529 dev->num_rx_queues = rxqs; 6530 dev->real_num_rx_queues = rxqs; 6531 if (netif_alloc_rx_queues(dev)) 6532 goto free_all; 6533 #endif 6534 6535 strcpy(dev->name, name); 6536 dev->group = INIT_NETDEV_GROUP; 6537 if (!dev->ethtool_ops) 6538 dev->ethtool_ops = &default_ethtool_ops; 6539 return dev; 6540 6541 free_all: 6542 free_netdev(dev); 6543 return NULL; 6544 6545 free_pcpu: 6546 free_percpu(dev->pcpu_refcnt); 6547 free_dev: 6548 netdev_freemem(dev); 6549 return NULL; 6550 } 6551 EXPORT_SYMBOL(alloc_netdev_mqs); 6552 6553 /** 6554 * free_netdev - free network device 6555 * @dev: device 6556 * 6557 * This function does the last stage of destroying an allocated device 6558 * interface. The reference to the device object is released. 6559 * If this is the last reference then it will be freed. 6560 */ 6561 void free_netdev(struct net_device *dev) 6562 { 6563 struct napi_struct *p, *n; 6564 6565 release_net(dev_net(dev)); 6566 6567 netif_free_tx_queues(dev); 6568 #ifdef CONFIG_SYSFS 6569 kfree(dev->_rx); 6570 #endif 6571 6572 kfree(rcu_dereference_protected(dev->ingress_queue, 1)); 6573 6574 /* Flush device addresses */ 6575 dev_addr_flush(dev); 6576 6577 list_for_each_entry_safe(p, n, &dev->napi_list, dev_list) 6578 netif_napi_del(p); 6579 6580 free_percpu(dev->pcpu_refcnt); 6581 dev->pcpu_refcnt = NULL; 6582 6583 /* Compatibility with error handling in drivers */ 6584 if (dev->reg_state == NETREG_UNINITIALIZED) { 6585 netdev_freemem(dev); 6586 return; 6587 } 6588 6589 BUG_ON(dev->reg_state != NETREG_UNREGISTERED); 6590 dev->reg_state = NETREG_RELEASED; 6591 6592 /* will free via device release */ 6593 put_device(&dev->dev); 6594 } 6595 EXPORT_SYMBOL(free_netdev); 6596 6597 /** 6598 * synchronize_net - Synchronize with packet receive processing 6599 * 6600 * Wait for packets currently being received to be done. 6601 * Does not block later packets from starting. 6602 */ 6603 void synchronize_net(void) 6604 { 6605 might_sleep(); 6606 if (rtnl_is_locked()) 6607 synchronize_rcu_expedited(); 6608 else 6609 synchronize_rcu(); 6610 } 6611 EXPORT_SYMBOL(synchronize_net); 6612 6613 /** 6614 * unregister_netdevice_queue - remove device from the kernel 6615 * @dev: device 6616 * @head: list 6617 * 6618 * This function shuts down a device interface and removes it 6619 * from the kernel tables. 6620 * If head not NULL, device is queued to be unregistered later. 6621 * 6622 * Callers must hold the rtnl semaphore. You may want 6623 * unregister_netdev() instead of this. 6624 */ 6625 6626 void unregister_netdevice_queue(struct net_device *dev, struct list_head *head) 6627 { 6628 ASSERT_RTNL(); 6629 6630 if (head) { 6631 list_move_tail(&dev->unreg_list, head); 6632 } else { 6633 rollback_registered(dev); 6634 /* Finish processing unregister after unlock */ 6635 net_set_todo(dev); 6636 } 6637 } 6638 EXPORT_SYMBOL(unregister_netdevice_queue); 6639 6640 /** 6641 * unregister_netdevice_many - unregister many devices 6642 * @head: list of devices 6643 * 6644 * Note: As most callers use a stack allocated list_head, 6645 * we force a list_del() to make sure stack wont be corrupted later. 6646 */ 6647 void unregister_netdevice_many(struct list_head *head) 6648 { 6649 struct net_device *dev; 6650 6651 if (!list_empty(head)) { 6652 rollback_registered_many(head); 6653 list_for_each_entry(dev, head, unreg_list) 6654 net_set_todo(dev); 6655 list_del(head); 6656 } 6657 } 6658 EXPORT_SYMBOL(unregister_netdevice_many); 6659 6660 /** 6661 * unregister_netdev - remove device from the kernel 6662 * @dev: device 6663 * 6664 * This function shuts down a device interface and removes it 6665 * from the kernel tables. 6666 * 6667 * This is just a wrapper for unregister_netdevice that takes 6668 * the rtnl semaphore. In general you want to use this and not 6669 * unregister_netdevice. 6670 */ 6671 void unregister_netdev(struct net_device *dev) 6672 { 6673 rtnl_lock(); 6674 unregister_netdevice(dev); 6675 rtnl_unlock(); 6676 } 6677 EXPORT_SYMBOL(unregister_netdev); 6678 6679 /** 6680 * dev_change_net_namespace - move device to different nethost namespace 6681 * @dev: device 6682 * @net: network namespace 6683 * @pat: If not NULL name pattern to try if the current device name 6684 * is already taken in the destination network namespace. 6685 * 6686 * This function shuts down a device interface and moves it 6687 * to a new network namespace. On success 0 is returned, on 6688 * a failure a netagive errno code is returned. 6689 * 6690 * Callers must hold the rtnl semaphore. 6691 */ 6692 6693 int dev_change_net_namespace(struct net_device *dev, struct net *net, const char *pat) 6694 { 6695 int err; 6696 6697 ASSERT_RTNL(); 6698 6699 /* Don't allow namespace local devices to be moved. */ 6700 err = -EINVAL; 6701 if (dev->features & NETIF_F_NETNS_LOCAL) 6702 goto out; 6703 6704 /* Ensure the device has been registrered */ 6705 if (dev->reg_state != NETREG_REGISTERED) 6706 goto out; 6707 6708 /* Get out if there is nothing todo */ 6709 err = 0; 6710 if (net_eq(dev_net(dev), net)) 6711 goto out; 6712 6713 /* Pick the destination device name, and ensure 6714 * we can use it in the destination network namespace. 6715 */ 6716 err = -EEXIST; 6717 if (__dev_get_by_name(net, dev->name)) { 6718 /* We get here if we can't use the current device name */ 6719 if (!pat) 6720 goto out; 6721 if (dev_get_valid_name(net, dev, pat) < 0) 6722 goto out; 6723 } 6724 6725 /* 6726 * And now a mini version of register_netdevice unregister_netdevice. 6727 */ 6728 6729 /* If device is running close it first. */ 6730 dev_close(dev); 6731 6732 /* And unlink it from device chain */ 6733 err = -ENODEV; 6734 unlist_netdevice(dev); 6735 6736 synchronize_net(); 6737 6738 /* Shutdown queueing discipline. */ 6739 dev_shutdown(dev); 6740 6741 /* Notify protocols, that we are about to destroy 6742 this device. They should clean all the things. 6743 6744 Note that dev->reg_state stays at NETREG_REGISTERED. 6745 This is wanted because this way 8021q and macvlan know 6746 the device is just moving and can keep their slaves up. 6747 */ 6748 call_netdevice_notifiers(NETDEV_UNREGISTER, dev); 6749 rcu_barrier(); 6750 call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev); 6751 rtmsg_ifinfo(RTM_DELLINK, dev, ~0U, GFP_KERNEL); 6752 6753 /* 6754 * Flush the unicast and multicast chains 6755 */ 6756 dev_uc_flush(dev); 6757 dev_mc_flush(dev); 6758 6759 /* Send a netdev-removed uevent to the old namespace */ 6760 kobject_uevent(&dev->dev.kobj, KOBJ_REMOVE); 6761 6762 /* Actually switch the network namespace */ 6763 dev_net_set(dev, net); 6764 6765 /* If there is an ifindex conflict assign a new one */ 6766 if (__dev_get_by_index(net, dev->ifindex)) { 6767 int iflink = (dev->iflink == dev->ifindex); 6768 dev->ifindex = dev_new_index(net); 6769 if (iflink) 6770 dev->iflink = dev->ifindex; 6771 } 6772 6773 /* Send a netdev-add uevent to the new namespace */ 6774 kobject_uevent(&dev->dev.kobj, KOBJ_ADD); 6775 6776 /* Fixup kobjects */ 6777 err = device_rename(&dev->dev, dev->name); 6778 WARN_ON(err); 6779 6780 /* Add the device back in the hashes */ 6781 list_netdevice(dev); 6782 6783 /* Notify protocols, that a new device appeared. */ 6784 call_netdevice_notifiers(NETDEV_REGISTER, dev); 6785 6786 /* 6787 * Prevent userspace races by waiting until the network 6788 * device is fully setup before sending notifications. 6789 */ 6790 rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL); 6791 6792 synchronize_net(); 6793 err = 0; 6794 out: 6795 return err; 6796 } 6797 EXPORT_SYMBOL_GPL(dev_change_net_namespace); 6798 6799 static int dev_cpu_callback(struct notifier_block *nfb, 6800 unsigned long action, 6801 void *ocpu) 6802 { 6803 struct sk_buff **list_skb; 6804 struct sk_buff *skb; 6805 unsigned int cpu, oldcpu = (unsigned long)ocpu; 6806 struct softnet_data *sd, *oldsd; 6807 6808 if (action != CPU_DEAD && action != CPU_DEAD_FROZEN) 6809 return NOTIFY_OK; 6810 6811 local_irq_disable(); 6812 cpu = smp_processor_id(); 6813 sd = &per_cpu(softnet_data, cpu); 6814 oldsd = &per_cpu(softnet_data, oldcpu); 6815 6816 /* Find end of our completion_queue. */ 6817 list_skb = &sd->completion_queue; 6818 while (*list_skb) 6819 list_skb = &(*list_skb)->next; 6820 /* Append completion queue from offline CPU. */ 6821 *list_skb = oldsd->completion_queue; 6822 oldsd->completion_queue = NULL; 6823 6824 /* Append output queue from offline CPU. */ 6825 if (oldsd->output_queue) { 6826 *sd->output_queue_tailp = oldsd->output_queue; 6827 sd->output_queue_tailp = oldsd->output_queue_tailp; 6828 oldsd->output_queue = NULL; 6829 oldsd->output_queue_tailp = &oldsd->output_queue; 6830 } 6831 /* Append NAPI poll list from offline CPU. */ 6832 if (!list_empty(&oldsd->poll_list)) { 6833 list_splice_init(&oldsd->poll_list, &sd->poll_list); 6834 raise_softirq_irqoff(NET_RX_SOFTIRQ); 6835 } 6836 6837 raise_softirq_irqoff(NET_TX_SOFTIRQ); 6838 local_irq_enable(); 6839 6840 /* Process offline CPU's input_pkt_queue */ 6841 while ((skb = __skb_dequeue(&oldsd->process_queue))) { 6842 netif_rx_internal(skb); 6843 input_queue_head_incr(oldsd); 6844 } 6845 while ((skb = __skb_dequeue(&oldsd->input_pkt_queue))) { 6846 netif_rx_internal(skb); 6847 input_queue_head_incr(oldsd); 6848 } 6849 6850 return NOTIFY_OK; 6851 } 6852 6853 6854 /** 6855 * netdev_increment_features - increment feature set by one 6856 * @all: current feature set 6857 * @one: new feature set 6858 * @mask: mask feature set 6859 * 6860 * Computes a new feature set after adding a device with feature set 6861 * @one to the master device with current feature set @all. Will not 6862 * enable anything that is off in @mask. Returns the new feature set. 6863 */ 6864 netdev_features_t netdev_increment_features(netdev_features_t all, 6865 netdev_features_t one, netdev_features_t mask) 6866 { 6867 if (mask & NETIF_F_GEN_CSUM) 6868 mask |= NETIF_F_ALL_CSUM; 6869 mask |= NETIF_F_VLAN_CHALLENGED; 6870 6871 all |= one & (NETIF_F_ONE_FOR_ALL|NETIF_F_ALL_CSUM) & mask; 6872 all &= one | ~NETIF_F_ALL_FOR_ALL; 6873 6874 /* If one device supports hw checksumming, set for all. */ 6875 if (all & NETIF_F_GEN_CSUM) 6876 all &= ~(NETIF_F_ALL_CSUM & ~NETIF_F_GEN_CSUM); 6877 6878 return all; 6879 } 6880 EXPORT_SYMBOL(netdev_increment_features); 6881 6882 static struct hlist_head * __net_init netdev_create_hash(void) 6883 { 6884 int i; 6885 struct hlist_head *hash; 6886 6887 hash = kmalloc(sizeof(*hash) * NETDEV_HASHENTRIES, GFP_KERNEL); 6888 if (hash != NULL) 6889 for (i = 0; i < NETDEV_HASHENTRIES; i++) 6890 INIT_HLIST_HEAD(&hash[i]); 6891 6892 return hash; 6893 } 6894 6895 /* Initialize per network namespace state */ 6896 static int __net_init netdev_init(struct net *net) 6897 { 6898 if (net != &init_net) 6899 INIT_LIST_HEAD(&net->dev_base_head); 6900 6901 net->dev_name_head = netdev_create_hash(); 6902 if (net->dev_name_head == NULL) 6903 goto err_name; 6904 6905 net->dev_index_head = netdev_create_hash(); 6906 if (net->dev_index_head == NULL) 6907 goto err_idx; 6908 6909 return 0; 6910 6911 err_idx: 6912 kfree(net->dev_name_head); 6913 err_name: 6914 return -ENOMEM; 6915 } 6916 6917 /** 6918 * netdev_drivername - network driver for the device 6919 * @dev: network device 6920 * 6921 * Determine network driver for device. 6922 */ 6923 const char *netdev_drivername(const struct net_device *dev) 6924 { 6925 const struct device_driver *driver; 6926 const struct device *parent; 6927 const char *empty = ""; 6928 6929 parent = dev->dev.parent; 6930 if (!parent) 6931 return empty; 6932 6933 driver = parent->driver; 6934 if (driver && driver->name) 6935 return driver->name; 6936 return empty; 6937 } 6938 6939 static int __netdev_printk(const char *level, const struct net_device *dev, 6940 struct va_format *vaf) 6941 { 6942 int r; 6943 6944 if (dev && dev->dev.parent) { 6945 r = dev_printk_emit(level[1] - '0', 6946 dev->dev.parent, 6947 "%s %s %s: %pV", 6948 dev_driver_string(dev->dev.parent), 6949 dev_name(dev->dev.parent), 6950 netdev_name(dev), vaf); 6951 } else if (dev) { 6952 r = printk("%s%s: %pV", level, netdev_name(dev), vaf); 6953 } else { 6954 r = printk("%s(NULL net_device): %pV", level, vaf); 6955 } 6956 6957 return r; 6958 } 6959 6960 int netdev_printk(const char *level, const struct net_device *dev, 6961 const char *format, ...) 6962 { 6963 struct va_format vaf; 6964 va_list args; 6965 int r; 6966 6967 va_start(args, format); 6968 6969 vaf.fmt = format; 6970 vaf.va = &args; 6971 6972 r = __netdev_printk(level, dev, &vaf); 6973 6974 va_end(args); 6975 6976 return r; 6977 } 6978 EXPORT_SYMBOL(netdev_printk); 6979 6980 #define define_netdev_printk_level(func, level) \ 6981 int func(const struct net_device *dev, const char *fmt, ...) \ 6982 { \ 6983 int r; \ 6984 struct va_format vaf; \ 6985 va_list args; \ 6986 \ 6987 va_start(args, fmt); \ 6988 \ 6989 vaf.fmt = fmt; \ 6990 vaf.va = &args; \ 6991 \ 6992 r = __netdev_printk(level, dev, &vaf); \ 6993 \ 6994 va_end(args); \ 6995 \ 6996 return r; \ 6997 } \ 6998 EXPORT_SYMBOL(func); 6999 7000 define_netdev_printk_level(netdev_emerg, KERN_EMERG); 7001 define_netdev_printk_level(netdev_alert, KERN_ALERT); 7002 define_netdev_printk_level(netdev_crit, KERN_CRIT); 7003 define_netdev_printk_level(netdev_err, KERN_ERR); 7004 define_netdev_printk_level(netdev_warn, KERN_WARNING); 7005 define_netdev_printk_level(netdev_notice, KERN_NOTICE); 7006 define_netdev_printk_level(netdev_info, KERN_INFO); 7007 7008 static void __net_exit netdev_exit(struct net *net) 7009 { 7010 kfree(net->dev_name_head); 7011 kfree(net->dev_index_head); 7012 } 7013 7014 static struct pernet_operations __net_initdata netdev_net_ops = { 7015 .init = netdev_init, 7016 .exit = netdev_exit, 7017 }; 7018 7019 static void __net_exit default_device_exit(struct net *net) 7020 { 7021 struct net_device *dev, *aux; 7022 /* 7023 * Push all migratable network devices back to the 7024 * initial network namespace 7025 */ 7026 rtnl_lock(); 7027 for_each_netdev_safe(net, dev, aux) { 7028 int err; 7029 char fb_name[IFNAMSIZ]; 7030 7031 /* Ignore unmoveable devices (i.e. loopback) */ 7032 if (dev->features & NETIF_F_NETNS_LOCAL) 7033 continue; 7034 7035 /* Leave virtual devices for the generic cleanup */ 7036 if (dev->rtnl_link_ops) 7037 continue; 7038 7039 /* Push remaining network devices to init_net */ 7040 snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex); 7041 err = dev_change_net_namespace(dev, &init_net, fb_name); 7042 if (err) { 7043 pr_emerg("%s: failed to move %s to init_net: %d\n", 7044 __func__, dev->name, err); 7045 BUG(); 7046 } 7047 } 7048 rtnl_unlock(); 7049 } 7050 7051 static void __net_exit rtnl_lock_unregistering(struct list_head *net_list) 7052 { 7053 /* Return with the rtnl_lock held when there are no network 7054 * devices unregistering in any network namespace in net_list. 7055 */ 7056 struct net *net; 7057 bool unregistering; 7058 DEFINE_WAIT(wait); 7059 7060 for (;;) { 7061 prepare_to_wait(&netdev_unregistering_wq, &wait, 7062 TASK_UNINTERRUPTIBLE); 7063 unregistering = false; 7064 rtnl_lock(); 7065 list_for_each_entry(net, net_list, exit_list) { 7066 if (net->dev_unreg_count > 0) { 7067 unregistering = true; 7068 break; 7069 } 7070 } 7071 if (!unregistering) 7072 break; 7073 __rtnl_unlock(); 7074 schedule(); 7075 } 7076 finish_wait(&netdev_unregistering_wq, &wait); 7077 } 7078 7079 static void __net_exit default_device_exit_batch(struct list_head *net_list) 7080 { 7081 /* At exit all network devices most be removed from a network 7082 * namespace. Do this in the reverse order of registration. 7083 * Do this across as many network namespaces as possible to 7084 * improve batching efficiency. 7085 */ 7086 struct net_device *dev; 7087 struct net *net; 7088 LIST_HEAD(dev_kill_list); 7089 7090 /* To prevent network device cleanup code from dereferencing 7091 * loopback devices or network devices that have been freed 7092 * wait here for all pending unregistrations to complete, 7093 * before unregistring the loopback device and allowing the 7094 * network namespace be freed. 7095 * 7096 * The netdev todo list containing all network devices 7097 * unregistrations that happen in default_device_exit_batch 7098 * will run in the rtnl_unlock() at the end of 7099 * default_device_exit_batch. 7100 */ 7101 rtnl_lock_unregistering(net_list); 7102 list_for_each_entry(net, net_list, exit_list) { 7103 for_each_netdev_reverse(net, dev) { 7104 if (dev->rtnl_link_ops) 7105 dev->rtnl_link_ops->dellink(dev, &dev_kill_list); 7106 else 7107 unregister_netdevice_queue(dev, &dev_kill_list); 7108 } 7109 } 7110 unregister_netdevice_many(&dev_kill_list); 7111 rtnl_unlock(); 7112 } 7113 7114 static struct pernet_operations __net_initdata default_device_ops = { 7115 .exit = default_device_exit, 7116 .exit_batch = default_device_exit_batch, 7117 }; 7118 7119 /* 7120 * Initialize the DEV module. At boot time this walks the device list and 7121 * unhooks any devices that fail to initialise (normally hardware not 7122 * present) and leaves us with a valid list of present and active devices. 7123 * 7124 */ 7125 7126 /* 7127 * This is called single threaded during boot, so no need 7128 * to take the rtnl semaphore. 7129 */ 7130 static int __init net_dev_init(void) 7131 { 7132 int i, rc = -ENOMEM; 7133 7134 BUG_ON(!dev_boot_phase); 7135 7136 if (dev_proc_init()) 7137 goto out; 7138 7139 if (netdev_kobject_init()) 7140 goto out; 7141 7142 INIT_LIST_HEAD(&ptype_all); 7143 for (i = 0; i < PTYPE_HASH_SIZE; i++) 7144 INIT_LIST_HEAD(&ptype_base[i]); 7145 7146 INIT_LIST_HEAD(&offload_base); 7147 7148 if (register_pernet_subsys(&netdev_net_ops)) 7149 goto out; 7150 7151 /* 7152 * Initialise the packet receive queues. 7153 */ 7154 7155 for_each_possible_cpu(i) { 7156 struct softnet_data *sd = &per_cpu(softnet_data, i); 7157 7158 skb_queue_head_init(&sd->input_pkt_queue); 7159 skb_queue_head_init(&sd->process_queue); 7160 INIT_LIST_HEAD(&sd->poll_list); 7161 sd->output_queue_tailp = &sd->output_queue; 7162 #ifdef CONFIG_RPS 7163 sd->csd.func = rps_trigger_softirq; 7164 sd->csd.info = sd; 7165 sd->cpu = i; 7166 #endif 7167 7168 sd->backlog.poll = process_backlog; 7169 sd->backlog.weight = weight_p; 7170 } 7171 7172 dev_boot_phase = 0; 7173 7174 /* The loopback device is special if any other network devices 7175 * is present in a network namespace the loopback device must 7176 * be present. Since we now dynamically allocate and free the 7177 * loopback device ensure this invariant is maintained by 7178 * keeping the loopback device as the first device on the 7179 * list of network devices. Ensuring the loopback devices 7180 * is the first device that appears and the last network device 7181 * that disappears. 7182 */ 7183 if (register_pernet_device(&loopback_net_ops)) 7184 goto out; 7185 7186 if (register_pernet_device(&default_device_ops)) 7187 goto out; 7188 7189 open_softirq(NET_TX_SOFTIRQ, net_tx_action); 7190 open_softirq(NET_RX_SOFTIRQ, net_rx_action); 7191 7192 hotcpu_notifier(dev_cpu_callback, 0); 7193 dst_init(); 7194 rc = 0; 7195 out: 7196 return rc; 7197 } 7198 7199 subsys_initcall(net_dev_init); 7200