1 /* 2 * TUN - Universal TUN/TAP device driver. 3 * Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com> 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License as published by 7 * the Free Software Foundation; either version 2 of the License, or 8 * (at your option) any later version. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $ 16 */ 17 18 /* 19 * Changes: 20 * 21 * Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14 22 * Add TUNSETLINK ioctl to set the link encapsulation 23 * 24 * Mark Smith <markzzzsmith@yahoo.com.au> 25 * Use eth_random_addr() for tap MAC address. 26 * 27 * Harald Roelle <harald.roelle@ifi.lmu.de> 2004/04/20 28 * Fixes in packet dropping, queue length setting and queue wakeup. 29 * Increased default tx queue length. 30 * Added ethtool API. 31 * Minor cleanups 32 * 33 * Daniel Podlejski <underley@underley.eu.org> 34 * Modifications for 2.3.99-pre5 kernel. 35 */ 36 37 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 38 39 #define DRV_NAME "tun" 40 #define DRV_VERSION "1.6" 41 #define DRV_DESCRIPTION "Universal TUN/TAP device driver" 42 #define DRV_COPYRIGHT "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>" 43 44 #include <linux/module.h> 45 #include <linux/errno.h> 46 #include <linux/kernel.h> 47 #include <linux/major.h> 48 #include <linux/slab.h> 49 #include <linux/poll.h> 50 #include <linux/fcntl.h> 51 #include <linux/init.h> 52 #include <linux/skbuff.h> 53 #include <linux/netdevice.h> 54 #include <linux/etherdevice.h> 55 #include <linux/miscdevice.h> 56 #include <linux/ethtool.h> 57 #include <linux/rtnetlink.h> 58 #include <linux/compat.h> 59 #include <linux/if.h> 60 #include <linux/if_arp.h> 61 #include <linux/if_ether.h> 62 #include <linux/if_tun.h> 63 #include <linux/if_vlan.h> 64 #include <linux/crc32.h> 65 #include <linux/nsproxy.h> 66 #include <linux/virtio_net.h> 67 #include <linux/rcupdate.h> 68 #include <net/net_namespace.h> 69 #include <net/netns/generic.h> 70 #include <net/rtnetlink.h> 71 #include <net/sock.h> 72 #include <linux/seq_file.h> 73 #include <linux/uio.h> 74 75 #include <asm/uaccess.h> 76 77 /* Uncomment to enable debugging */ 78 /* #define TUN_DEBUG 1 */ 79 80 #ifdef TUN_DEBUG 81 static int debug; 82 83 #define tun_debug(level, tun, fmt, args...) \ 84 do { \ 85 if (tun->debug) \ 86 netdev_printk(level, tun->dev, fmt, ##args); \ 87 } while (0) 88 #define DBG1(level, fmt, args...) \ 89 do { \ 90 if (debug == 2) \ 91 printk(level fmt, ##args); \ 92 } while (0) 93 #else 94 #define tun_debug(level, tun, fmt, args...) \ 95 do { \ 96 if (0) \ 97 netdev_printk(level, tun->dev, fmt, ##args); \ 98 } while (0) 99 #define DBG1(level, fmt, args...) \ 100 do { \ 101 if (0) \ 102 printk(level fmt, ##args); \ 103 } while (0) 104 #endif 105 106 /* TUN device flags */ 107 108 /* IFF_ATTACH_QUEUE is never stored in device flags, 109 * overload it to mean fasync when stored there. 110 */ 111 #define TUN_FASYNC IFF_ATTACH_QUEUE 112 /* High bits in flags field are unused. */ 113 #define TUN_VNET_LE 0x80000000 114 #define TUN_VNET_BE 0x40000000 115 116 #define TUN_FEATURES (IFF_NO_PI | IFF_ONE_QUEUE | IFF_VNET_HDR | \ 117 IFF_MULTI_QUEUE) 118 #define GOODCOPY_LEN 128 119 120 #define FLT_EXACT_COUNT 8 121 struct tap_filter { 122 unsigned int count; /* Number of addrs. Zero means disabled */ 123 u32 mask[2]; /* Mask of the hashed addrs */ 124 unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN]; 125 }; 126 127 /* MAX_TAP_QUEUES 256 is chosen to allow rx/tx queues to be equal 128 * to max number of VCPUs in guest. */ 129 #define MAX_TAP_QUEUES 256 130 #define MAX_TAP_FLOWS 4096 131 132 #define TUN_FLOW_EXPIRE (3 * HZ) 133 134 /* A tun_file connects an open character device to a tuntap netdevice. It 135 * also contains all socket related structures (except sock_fprog and tap_filter) 136 * to serve as one transmit queue for tuntap device. The sock_fprog and 137 * tap_filter were kept in tun_struct since they were used for filtering for the 138 * netdevice not for a specific queue (at least I didn't see the requirement for 139 * this). 140 * 141 * RCU usage: 142 * The tun_file and tun_struct are loosely coupled, the pointer from one to the 143 * other can only be read while rcu_read_lock or rtnl_lock is held. 144 */ 145 struct tun_file { 146 struct sock sk; 147 struct socket socket; 148 struct socket_wq wq; 149 struct tun_struct __rcu *tun; 150 struct fasync_struct *fasync; 151 /* only used for fasnyc */ 152 unsigned int flags; 153 union { 154 u16 queue_index; 155 unsigned int ifindex; 156 }; 157 struct list_head next; 158 struct tun_struct *detached; 159 }; 160 161 struct tun_flow_entry { 162 struct hlist_node hash_link; 163 struct rcu_head rcu; 164 struct tun_struct *tun; 165 166 u32 rxhash; 167 u32 rps_rxhash; 168 int queue_index; 169 unsigned long updated; 170 }; 171 172 #define TUN_NUM_FLOW_ENTRIES 1024 173 174 /* Since the socket were moved to tun_file, to preserve the behavior of persist 175 * device, socket filter, sndbuf and vnet header size were restore when the 176 * file were attached to a persist device. 177 */ 178 struct tun_struct { 179 struct tun_file __rcu *tfiles[MAX_TAP_QUEUES]; 180 unsigned int numqueues; 181 unsigned int flags; 182 kuid_t owner; 183 kgid_t group; 184 185 struct net_device *dev; 186 netdev_features_t set_features; 187 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \ 188 NETIF_F_TSO6|NETIF_F_UFO) 189 190 int align; 191 int vnet_hdr_sz; 192 int sndbuf; 193 struct tap_filter txflt; 194 struct sock_fprog fprog; 195 /* protected by rtnl lock */ 196 bool filter_attached; 197 #ifdef TUN_DEBUG 198 int debug; 199 #endif 200 spinlock_t lock; 201 struct hlist_head flows[TUN_NUM_FLOW_ENTRIES]; 202 struct timer_list flow_gc_timer; 203 unsigned long ageing_time; 204 unsigned int numdisabled; 205 struct list_head disabled; 206 void *security; 207 u32 flow_count; 208 }; 209 210 #ifdef CONFIG_TUN_VNET_CROSS_LE 211 static inline bool tun_legacy_is_little_endian(struct tun_struct *tun) 212 { 213 return tun->flags & TUN_VNET_BE ? false : 214 virtio_legacy_is_little_endian(); 215 } 216 217 static long tun_get_vnet_be(struct tun_struct *tun, int __user *argp) 218 { 219 int be = !!(tun->flags & TUN_VNET_BE); 220 221 if (put_user(be, argp)) 222 return -EFAULT; 223 224 return 0; 225 } 226 227 static long tun_set_vnet_be(struct tun_struct *tun, int __user *argp) 228 { 229 int be; 230 231 if (get_user(be, argp)) 232 return -EFAULT; 233 234 if (be) 235 tun->flags |= TUN_VNET_BE; 236 else 237 tun->flags &= ~TUN_VNET_BE; 238 239 return 0; 240 } 241 #else 242 static inline bool tun_legacy_is_little_endian(struct tun_struct *tun) 243 { 244 return virtio_legacy_is_little_endian(); 245 } 246 247 static long tun_get_vnet_be(struct tun_struct *tun, int __user *argp) 248 { 249 return -EINVAL; 250 } 251 252 static long tun_set_vnet_be(struct tun_struct *tun, int __user *argp) 253 { 254 return -EINVAL; 255 } 256 #endif /* CONFIG_TUN_VNET_CROSS_LE */ 257 258 static inline bool tun_is_little_endian(struct tun_struct *tun) 259 { 260 return tun->flags & TUN_VNET_LE || 261 tun_legacy_is_little_endian(tun); 262 } 263 264 static inline u16 tun16_to_cpu(struct tun_struct *tun, __virtio16 val) 265 { 266 return __virtio16_to_cpu(tun_is_little_endian(tun), val); 267 } 268 269 static inline __virtio16 cpu_to_tun16(struct tun_struct *tun, u16 val) 270 { 271 return __cpu_to_virtio16(tun_is_little_endian(tun), val); 272 } 273 274 static inline u32 tun_hashfn(u32 rxhash) 275 { 276 return rxhash & 0x3ff; 277 } 278 279 static struct tun_flow_entry *tun_flow_find(struct hlist_head *head, u32 rxhash) 280 { 281 struct tun_flow_entry *e; 282 283 hlist_for_each_entry_rcu(e, head, hash_link) { 284 if (e->rxhash == rxhash) 285 return e; 286 } 287 return NULL; 288 } 289 290 static struct tun_flow_entry *tun_flow_create(struct tun_struct *tun, 291 struct hlist_head *head, 292 u32 rxhash, u16 queue_index) 293 { 294 struct tun_flow_entry *e = kmalloc(sizeof(*e), GFP_ATOMIC); 295 296 if (e) { 297 tun_debug(KERN_INFO, tun, "create flow: hash %u index %u\n", 298 rxhash, queue_index); 299 e->updated = jiffies; 300 e->rxhash = rxhash; 301 e->rps_rxhash = 0; 302 e->queue_index = queue_index; 303 e->tun = tun; 304 hlist_add_head_rcu(&e->hash_link, head); 305 ++tun->flow_count; 306 } 307 return e; 308 } 309 310 static void tun_flow_delete(struct tun_struct *tun, struct tun_flow_entry *e) 311 { 312 tun_debug(KERN_INFO, tun, "delete flow: hash %u index %u\n", 313 e->rxhash, e->queue_index); 314 hlist_del_rcu(&e->hash_link); 315 kfree_rcu(e, rcu); 316 --tun->flow_count; 317 } 318 319 static void tun_flow_flush(struct tun_struct *tun) 320 { 321 int i; 322 323 spin_lock_bh(&tun->lock); 324 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) { 325 struct tun_flow_entry *e; 326 struct hlist_node *n; 327 328 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) 329 tun_flow_delete(tun, e); 330 } 331 spin_unlock_bh(&tun->lock); 332 } 333 334 static void tun_flow_delete_by_queue(struct tun_struct *tun, u16 queue_index) 335 { 336 int i; 337 338 spin_lock_bh(&tun->lock); 339 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) { 340 struct tun_flow_entry *e; 341 struct hlist_node *n; 342 343 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) { 344 if (e->queue_index == queue_index) 345 tun_flow_delete(tun, e); 346 } 347 } 348 spin_unlock_bh(&tun->lock); 349 } 350 351 static void tun_flow_cleanup(unsigned long data) 352 { 353 struct tun_struct *tun = (struct tun_struct *)data; 354 unsigned long delay = tun->ageing_time; 355 unsigned long next_timer = jiffies + delay; 356 unsigned long count = 0; 357 int i; 358 359 tun_debug(KERN_INFO, tun, "tun_flow_cleanup\n"); 360 361 spin_lock_bh(&tun->lock); 362 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) { 363 struct tun_flow_entry *e; 364 struct hlist_node *n; 365 366 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) { 367 unsigned long this_timer; 368 count++; 369 this_timer = e->updated + delay; 370 if (time_before_eq(this_timer, jiffies)) 371 tun_flow_delete(tun, e); 372 else if (time_before(this_timer, next_timer)) 373 next_timer = this_timer; 374 } 375 } 376 377 if (count) 378 mod_timer(&tun->flow_gc_timer, round_jiffies_up(next_timer)); 379 spin_unlock_bh(&tun->lock); 380 } 381 382 static void tun_flow_update(struct tun_struct *tun, u32 rxhash, 383 struct tun_file *tfile) 384 { 385 struct hlist_head *head; 386 struct tun_flow_entry *e; 387 unsigned long delay = tun->ageing_time; 388 u16 queue_index = tfile->queue_index; 389 390 if (!rxhash) 391 return; 392 else 393 head = &tun->flows[tun_hashfn(rxhash)]; 394 395 rcu_read_lock(); 396 397 /* We may get a very small possibility of OOO during switching, not 398 * worth to optimize.*/ 399 if (tun->numqueues == 1 || tfile->detached) 400 goto unlock; 401 402 e = tun_flow_find(head, rxhash); 403 if (likely(e)) { 404 /* TODO: keep queueing to old queue until it's empty? */ 405 e->queue_index = queue_index; 406 e->updated = jiffies; 407 sock_rps_record_flow_hash(e->rps_rxhash); 408 } else { 409 spin_lock_bh(&tun->lock); 410 if (!tun_flow_find(head, rxhash) && 411 tun->flow_count < MAX_TAP_FLOWS) 412 tun_flow_create(tun, head, rxhash, queue_index); 413 414 if (!timer_pending(&tun->flow_gc_timer)) 415 mod_timer(&tun->flow_gc_timer, 416 round_jiffies_up(jiffies + delay)); 417 spin_unlock_bh(&tun->lock); 418 } 419 420 unlock: 421 rcu_read_unlock(); 422 } 423 424 /** 425 * Save the hash received in the stack receive path and update the 426 * flow_hash table accordingly. 427 */ 428 static inline void tun_flow_save_rps_rxhash(struct tun_flow_entry *e, u32 hash) 429 { 430 if (unlikely(e->rps_rxhash != hash)) 431 e->rps_rxhash = hash; 432 } 433 434 /* We try to identify a flow through its rxhash first. The reason that 435 * we do not check rxq no. is because some cards(e.g 82599), chooses 436 * the rxq based on the txq where the last packet of the flow comes. As 437 * the userspace application move between processors, we may get a 438 * different rxq no. here. If we could not get rxhash, then we would 439 * hope the rxq no. may help here. 440 */ 441 static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb, 442 void *accel_priv, select_queue_fallback_t fallback) 443 { 444 struct tun_struct *tun = netdev_priv(dev); 445 struct tun_flow_entry *e; 446 u32 txq = 0; 447 u32 numqueues = 0; 448 449 rcu_read_lock(); 450 numqueues = ACCESS_ONCE(tun->numqueues); 451 452 txq = skb_get_hash(skb); 453 if (txq) { 454 e = tun_flow_find(&tun->flows[tun_hashfn(txq)], txq); 455 if (e) { 456 tun_flow_save_rps_rxhash(e, txq); 457 txq = e->queue_index; 458 } else 459 /* use multiply and shift instead of expensive divide */ 460 txq = ((u64)txq * numqueues) >> 32; 461 } else if (likely(skb_rx_queue_recorded(skb))) { 462 txq = skb_get_rx_queue(skb); 463 while (unlikely(txq >= numqueues)) 464 txq -= numqueues; 465 } 466 467 rcu_read_unlock(); 468 return txq; 469 } 470 471 static inline bool tun_not_capable(struct tun_struct *tun) 472 { 473 const struct cred *cred = current_cred(); 474 struct net *net = dev_net(tun->dev); 475 476 return ((uid_valid(tun->owner) && !uid_eq(cred->euid, tun->owner)) || 477 (gid_valid(tun->group) && !in_egroup_p(tun->group))) && 478 !ns_capable(net->user_ns, CAP_NET_ADMIN); 479 } 480 481 static void tun_set_real_num_queues(struct tun_struct *tun) 482 { 483 netif_set_real_num_tx_queues(tun->dev, tun->numqueues); 484 netif_set_real_num_rx_queues(tun->dev, tun->numqueues); 485 } 486 487 static void tun_disable_queue(struct tun_struct *tun, struct tun_file *tfile) 488 { 489 tfile->detached = tun; 490 list_add_tail(&tfile->next, &tun->disabled); 491 ++tun->numdisabled; 492 } 493 494 static struct tun_struct *tun_enable_queue(struct tun_file *tfile) 495 { 496 struct tun_struct *tun = tfile->detached; 497 498 tfile->detached = NULL; 499 list_del_init(&tfile->next); 500 --tun->numdisabled; 501 return tun; 502 } 503 504 static void tun_queue_purge(struct tun_file *tfile) 505 { 506 skb_queue_purge(&tfile->sk.sk_receive_queue); 507 skb_queue_purge(&tfile->sk.sk_error_queue); 508 } 509 510 static void __tun_detach(struct tun_file *tfile, bool clean) 511 { 512 struct tun_file *ntfile; 513 struct tun_struct *tun; 514 515 tun = rtnl_dereference(tfile->tun); 516 517 if (tun && !tfile->detached) { 518 u16 index = tfile->queue_index; 519 BUG_ON(index >= tun->numqueues); 520 521 rcu_assign_pointer(tun->tfiles[index], 522 tun->tfiles[tun->numqueues - 1]); 523 ntfile = rtnl_dereference(tun->tfiles[index]); 524 ntfile->queue_index = index; 525 526 --tun->numqueues; 527 if (clean) { 528 RCU_INIT_POINTER(tfile->tun, NULL); 529 sock_put(&tfile->sk); 530 } else 531 tun_disable_queue(tun, tfile); 532 533 synchronize_net(); 534 tun_flow_delete_by_queue(tun, tun->numqueues + 1); 535 /* Drop read queue */ 536 tun_queue_purge(tfile); 537 tun_set_real_num_queues(tun); 538 } else if (tfile->detached && clean) { 539 tun = tun_enable_queue(tfile); 540 sock_put(&tfile->sk); 541 } 542 543 if (clean) { 544 if (tun && tun->numqueues == 0 && tun->numdisabled == 0) { 545 netif_carrier_off(tun->dev); 546 547 if (!(tun->flags & IFF_PERSIST) && 548 tun->dev->reg_state == NETREG_REGISTERED) 549 unregister_netdevice(tun->dev); 550 } 551 sock_put(&tfile->sk); 552 } 553 } 554 555 static void tun_detach(struct tun_file *tfile, bool clean) 556 { 557 rtnl_lock(); 558 __tun_detach(tfile, clean); 559 rtnl_unlock(); 560 } 561 562 static void tun_detach_all(struct net_device *dev) 563 { 564 struct tun_struct *tun = netdev_priv(dev); 565 struct tun_file *tfile, *tmp; 566 int i, n = tun->numqueues; 567 568 for (i = 0; i < n; i++) { 569 tfile = rtnl_dereference(tun->tfiles[i]); 570 BUG_ON(!tfile); 571 tfile->socket.sk->sk_data_ready(tfile->socket.sk); 572 RCU_INIT_POINTER(tfile->tun, NULL); 573 --tun->numqueues; 574 } 575 list_for_each_entry(tfile, &tun->disabled, next) { 576 tfile->socket.sk->sk_data_ready(tfile->socket.sk); 577 RCU_INIT_POINTER(tfile->tun, NULL); 578 } 579 BUG_ON(tun->numqueues != 0); 580 581 synchronize_net(); 582 for (i = 0; i < n; i++) { 583 tfile = rtnl_dereference(tun->tfiles[i]); 584 /* Drop read queue */ 585 tun_queue_purge(tfile); 586 sock_put(&tfile->sk); 587 } 588 list_for_each_entry_safe(tfile, tmp, &tun->disabled, next) { 589 tun_enable_queue(tfile); 590 tun_queue_purge(tfile); 591 sock_put(&tfile->sk); 592 } 593 BUG_ON(tun->numdisabled != 0); 594 595 if (tun->flags & IFF_PERSIST) 596 module_put(THIS_MODULE); 597 } 598 599 static int tun_attach(struct tun_struct *tun, struct file *file, bool skip_filter) 600 { 601 struct tun_file *tfile = file->private_data; 602 int err; 603 604 err = security_tun_dev_attach(tfile->socket.sk, tun->security); 605 if (err < 0) 606 goto out; 607 608 err = -EINVAL; 609 if (rtnl_dereference(tfile->tun) && !tfile->detached) 610 goto out; 611 612 err = -EBUSY; 613 if (!(tun->flags & IFF_MULTI_QUEUE) && tun->numqueues == 1) 614 goto out; 615 616 err = -E2BIG; 617 if (!tfile->detached && 618 tun->numqueues + tun->numdisabled == MAX_TAP_QUEUES) 619 goto out; 620 621 err = 0; 622 623 /* Re-attach the filter to persist device */ 624 if (!skip_filter && (tun->filter_attached == true)) { 625 err = __sk_attach_filter(&tun->fprog, tfile->socket.sk, 626 lockdep_rtnl_is_held()); 627 if (!err) 628 goto out; 629 } 630 tfile->queue_index = tun->numqueues; 631 rcu_assign_pointer(tfile->tun, tun); 632 rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile); 633 tun->numqueues++; 634 635 if (tfile->detached) 636 tun_enable_queue(tfile); 637 else 638 sock_hold(&tfile->sk); 639 640 tun_set_real_num_queues(tun); 641 642 /* device is allowed to go away first, so no need to hold extra 643 * refcnt. 644 */ 645 646 out: 647 return err; 648 } 649 650 static struct tun_struct *__tun_get(struct tun_file *tfile) 651 { 652 struct tun_struct *tun; 653 654 rcu_read_lock(); 655 tun = rcu_dereference(tfile->tun); 656 if (tun) 657 dev_hold(tun->dev); 658 rcu_read_unlock(); 659 660 return tun; 661 } 662 663 static struct tun_struct *tun_get(struct file *file) 664 { 665 return __tun_get(file->private_data); 666 } 667 668 static void tun_put(struct tun_struct *tun) 669 { 670 dev_put(tun->dev); 671 } 672 673 /* TAP filtering */ 674 static void addr_hash_set(u32 *mask, const u8 *addr) 675 { 676 int n = ether_crc(ETH_ALEN, addr) >> 26; 677 mask[n >> 5] |= (1 << (n & 31)); 678 } 679 680 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr) 681 { 682 int n = ether_crc(ETH_ALEN, addr) >> 26; 683 return mask[n >> 5] & (1 << (n & 31)); 684 } 685 686 static int update_filter(struct tap_filter *filter, void __user *arg) 687 { 688 struct { u8 u[ETH_ALEN]; } *addr; 689 struct tun_filter uf; 690 int err, alen, n, nexact; 691 692 if (copy_from_user(&uf, arg, sizeof(uf))) 693 return -EFAULT; 694 695 if (!uf.count) { 696 /* Disabled */ 697 filter->count = 0; 698 return 0; 699 } 700 701 alen = ETH_ALEN * uf.count; 702 addr = kmalloc(alen, GFP_KERNEL); 703 if (!addr) 704 return -ENOMEM; 705 706 if (copy_from_user(addr, arg + sizeof(uf), alen)) { 707 err = -EFAULT; 708 goto done; 709 } 710 711 /* The filter is updated without holding any locks. Which is 712 * perfectly safe. We disable it first and in the worst 713 * case we'll accept a few undesired packets. */ 714 filter->count = 0; 715 wmb(); 716 717 /* Use first set of addresses as an exact filter */ 718 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++) 719 memcpy(filter->addr[n], addr[n].u, ETH_ALEN); 720 721 nexact = n; 722 723 /* Remaining multicast addresses are hashed, 724 * unicast will leave the filter disabled. */ 725 memset(filter->mask, 0, sizeof(filter->mask)); 726 for (; n < uf.count; n++) { 727 if (!is_multicast_ether_addr(addr[n].u)) { 728 err = 0; /* no filter */ 729 goto done; 730 } 731 addr_hash_set(filter->mask, addr[n].u); 732 } 733 734 /* For ALLMULTI just set the mask to all ones. 735 * This overrides the mask populated above. */ 736 if ((uf.flags & TUN_FLT_ALLMULTI)) 737 memset(filter->mask, ~0, sizeof(filter->mask)); 738 739 /* Now enable the filter */ 740 wmb(); 741 filter->count = nexact; 742 743 /* Return the number of exact filters */ 744 err = nexact; 745 746 done: 747 kfree(addr); 748 return err; 749 } 750 751 /* Returns: 0 - drop, !=0 - accept */ 752 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb) 753 { 754 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect 755 * at this point. */ 756 struct ethhdr *eh = (struct ethhdr *) skb->data; 757 int i; 758 759 /* Exact match */ 760 for (i = 0; i < filter->count; i++) 761 if (ether_addr_equal(eh->h_dest, filter->addr[i])) 762 return 1; 763 764 /* Inexact match (multicast only) */ 765 if (is_multicast_ether_addr(eh->h_dest)) 766 return addr_hash_test(filter->mask, eh->h_dest); 767 768 return 0; 769 } 770 771 /* 772 * Checks whether the packet is accepted or not. 773 * Returns: 0 - drop, !=0 - accept 774 */ 775 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb) 776 { 777 if (!filter->count) 778 return 1; 779 780 return run_filter(filter, skb); 781 } 782 783 /* Network device part of the driver */ 784 785 static const struct ethtool_ops tun_ethtool_ops; 786 787 /* Net device detach from fd. */ 788 static void tun_net_uninit(struct net_device *dev) 789 { 790 tun_detach_all(dev); 791 } 792 793 /* Net device open. */ 794 static int tun_net_open(struct net_device *dev) 795 { 796 netif_tx_start_all_queues(dev); 797 return 0; 798 } 799 800 /* Net device close. */ 801 static int tun_net_close(struct net_device *dev) 802 { 803 netif_tx_stop_all_queues(dev); 804 return 0; 805 } 806 807 /* Net device start xmit */ 808 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev) 809 { 810 struct tun_struct *tun = netdev_priv(dev); 811 int txq = skb->queue_mapping; 812 struct tun_file *tfile; 813 u32 numqueues = 0; 814 815 rcu_read_lock(); 816 tfile = rcu_dereference(tun->tfiles[txq]); 817 numqueues = ACCESS_ONCE(tun->numqueues); 818 819 /* Drop packet if interface is not attached */ 820 if (txq >= numqueues) 821 goto drop; 822 823 if (numqueues == 1) { 824 /* Select queue was not called for the skbuff, so we extract the 825 * RPS hash and save it into the flow_table here. 826 */ 827 __u32 rxhash; 828 829 rxhash = skb_get_hash(skb); 830 if (rxhash) { 831 struct tun_flow_entry *e; 832 e = tun_flow_find(&tun->flows[tun_hashfn(rxhash)], 833 rxhash); 834 if (e) 835 tun_flow_save_rps_rxhash(e, rxhash); 836 } 837 } 838 839 tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len); 840 841 BUG_ON(!tfile); 842 843 /* Drop if the filter does not like it. 844 * This is a noop if the filter is disabled. 845 * Filter can be enabled only for the TAP devices. */ 846 if (!check_filter(&tun->txflt, skb)) 847 goto drop; 848 849 if (tfile->socket.sk->sk_filter && 850 sk_filter(tfile->socket.sk, skb)) 851 goto drop; 852 853 /* Limit the number of packets queued by dividing txq length with the 854 * number of queues. 855 */ 856 if (skb_queue_len(&tfile->socket.sk->sk_receive_queue) * numqueues 857 >= dev->tx_queue_len) 858 goto drop; 859 860 if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC))) 861 goto drop; 862 863 if (skb->sk && sk_fullsock(skb->sk)) { 864 sock_tx_timestamp(skb->sk, &skb_shinfo(skb)->tx_flags); 865 sw_tx_timestamp(skb); 866 } 867 868 /* Orphan the skb - required as we might hang on to it 869 * for indefinite time. 870 */ 871 skb_orphan(skb); 872 873 nf_reset(skb); 874 875 /* Enqueue packet */ 876 skb_queue_tail(&tfile->socket.sk->sk_receive_queue, skb); 877 878 /* Notify and wake up reader process */ 879 if (tfile->flags & TUN_FASYNC) 880 kill_fasync(&tfile->fasync, SIGIO, POLL_IN); 881 tfile->socket.sk->sk_data_ready(tfile->socket.sk); 882 883 rcu_read_unlock(); 884 return NETDEV_TX_OK; 885 886 drop: 887 dev->stats.tx_dropped++; 888 skb_tx_error(skb); 889 kfree_skb(skb); 890 rcu_read_unlock(); 891 return NET_XMIT_DROP; 892 } 893 894 static void tun_net_mclist(struct net_device *dev) 895 { 896 /* 897 * This callback is supposed to deal with mc filter in 898 * _rx_ path and has nothing to do with the _tx_ path. 899 * In rx path we always accept everything userspace gives us. 900 */ 901 } 902 903 #define MIN_MTU 68 904 #define MAX_MTU 65535 905 906 static int 907 tun_net_change_mtu(struct net_device *dev, int new_mtu) 908 { 909 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU) 910 return -EINVAL; 911 dev->mtu = new_mtu; 912 return 0; 913 } 914 915 static netdev_features_t tun_net_fix_features(struct net_device *dev, 916 netdev_features_t features) 917 { 918 struct tun_struct *tun = netdev_priv(dev); 919 920 return (features & tun->set_features) | (features & ~TUN_USER_FEATURES); 921 } 922 #ifdef CONFIG_NET_POLL_CONTROLLER 923 static void tun_poll_controller(struct net_device *dev) 924 { 925 /* 926 * Tun only receives frames when: 927 * 1) the char device endpoint gets data from user space 928 * 2) the tun socket gets a sendmsg call from user space 929 * Since both of those are synchronous operations, we are guaranteed 930 * never to have pending data when we poll for it 931 * so there is nothing to do here but return. 932 * We need this though so netpoll recognizes us as an interface that 933 * supports polling, which enables bridge devices in virt setups to 934 * still use netconsole 935 */ 936 return; 937 } 938 #endif 939 940 static void tun_set_headroom(struct net_device *dev, int new_hr) 941 { 942 struct tun_struct *tun = netdev_priv(dev); 943 944 if (new_hr < NET_SKB_PAD) 945 new_hr = NET_SKB_PAD; 946 947 tun->align = new_hr; 948 } 949 950 static const struct net_device_ops tun_netdev_ops = { 951 .ndo_uninit = tun_net_uninit, 952 .ndo_open = tun_net_open, 953 .ndo_stop = tun_net_close, 954 .ndo_start_xmit = tun_net_xmit, 955 .ndo_change_mtu = tun_net_change_mtu, 956 .ndo_fix_features = tun_net_fix_features, 957 .ndo_select_queue = tun_select_queue, 958 #ifdef CONFIG_NET_POLL_CONTROLLER 959 .ndo_poll_controller = tun_poll_controller, 960 #endif 961 .ndo_set_rx_headroom = tun_set_headroom, 962 }; 963 964 static const struct net_device_ops tap_netdev_ops = { 965 .ndo_uninit = tun_net_uninit, 966 .ndo_open = tun_net_open, 967 .ndo_stop = tun_net_close, 968 .ndo_start_xmit = tun_net_xmit, 969 .ndo_change_mtu = tun_net_change_mtu, 970 .ndo_fix_features = tun_net_fix_features, 971 .ndo_set_rx_mode = tun_net_mclist, 972 .ndo_set_mac_address = eth_mac_addr, 973 .ndo_validate_addr = eth_validate_addr, 974 .ndo_select_queue = tun_select_queue, 975 #ifdef CONFIG_NET_POLL_CONTROLLER 976 .ndo_poll_controller = tun_poll_controller, 977 #endif 978 .ndo_features_check = passthru_features_check, 979 .ndo_set_rx_headroom = tun_set_headroom, 980 }; 981 982 static void tun_flow_init(struct tun_struct *tun) 983 { 984 int i; 985 986 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) 987 INIT_HLIST_HEAD(&tun->flows[i]); 988 989 tun->ageing_time = TUN_FLOW_EXPIRE; 990 setup_timer(&tun->flow_gc_timer, tun_flow_cleanup, (unsigned long)tun); 991 mod_timer(&tun->flow_gc_timer, 992 round_jiffies_up(jiffies + tun->ageing_time)); 993 } 994 995 static void tun_flow_uninit(struct tun_struct *tun) 996 { 997 del_timer_sync(&tun->flow_gc_timer); 998 tun_flow_flush(tun); 999 } 1000 1001 /* Initialize net device. */ 1002 static void tun_net_init(struct net_device *dev) 1003 { 1004 struct tun_struct *tun = netdev_priv(dev); 1005 1006 switch (tun->flags & TUN_TYPE_MASK) { 1007 case IFF_TUN: 1008 dev->netdev_ops = &tun_netdev_ops; 1009 1010 /* Point-to-Point TUN Device */ 1011 dev->hard_header_len = 0; 1012 dev->addr_len = 0; 1013 dev->mtu = 1500; 1014 1015 /* Zero header length */ 1016 dev->type = ARPHRD_NONE; 1017 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 1018 break; 1019 1020 case IFF_TAP: 1021 dev->netdev_ops = &tap_netdev_ops; 1022 /* Ethernet TAP Device */ 1023 ether_setup(dev); 1024 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 1025 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1026 1027 eth_hw_addr_random(dev); 1028 1029 break; 1030 } 1031 } 1032 1033 /* Character device part */ 1034 1035 /* Poll */ 1036 static unsigned int tun_chr_poll(struct file *file, poll_table *wait) 1037 { 1038 struct tun_file *tfile = file->private_data; 1039 struct tun_struct *tun = __tun_get(tfile); 1040 struct sock *sk; 1041 unsigned int mask = 0; 1042 1043 if (!tun) 1044 return POLLERR; 1045 1046 sk = tfile->socket.sk; 1047 1048 tun_debug(KERN_INFO, tun, "tun_chr_poll\n"); 1049 1050 poll_wait(file, sk_sleep(sk), wait); 1051 1052 if (!skb_queue_empty(&sk->sk_receive_queue)) 1053 mask |= POLLIN | POLLRDNORM; 1054 1055 if (sock_writeable(sk) || 1056 (!test_and_set_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags) && 1057 sock_writeable(sk))) 1058 mask |= POLLOUT | POLLWRNORM; 1059 1060 if (tun->dev->reg_state != NETREG_REGISTERED) 1061 mask = POLLERR; 1062 1063 tun_put(tun); 1064 return mask; 1065 } 1066 1067 /* prepad is the amount to reserve at front. len is length after that. 1068 * linear is a hint as to how much to copy (usually headers). */ 1069 static struct sk_buff *tun_alloc_skb(struct tun_file *tfile, 1070 size_t prepad, size_t len, 1071 size_t linear, int noblock) 1072 { 1073 struct sock *sk = tfile->socket.sk; 1074 struct sk_buff *skb; 1075 int err; 1076 1077 /* Under a page? Don't bother with paged skb. */ 1078 if (prepad + len < PAGE_SIZE || !linear) 1079 linear = len; 1080 1081 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 1082 &err, 0); 1083 if (!skb) 1084 return ERR_PTR(err); 1085 1086 skb_reserve(skb, prepad); 1087 skb_put(skb, linear); 1088 skb->data_len = len - linear; 1089 skb->len += len - linear; 1090 1091 return skb; 1092 } 1093 1094 /* Get packet from user space buffer */ 1095 static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile, 1096 void *msg_control, struct iov_iter *from, 1097 int noblock) 1098 { 1099 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) }; 1100 struct sk_buff *skb; 1101 size_t total_len = iov_iter_count(from); 1102 size_t len = total_len, align = tun->align, linear; 1103 struct virtio_net_hdr gso = { 0 }; 1104 int good_linear; 1105 int copylen; 1106 bool zerocopy = false; 1107 int err; 1108 u32 rxhash; 1109 ssize_t n; 1110 1111 if (!(tun->dev->flags & IFF_UP)) 1112 return -EIO; 1113 1114 if (!(tun->flags & IFF_NO_PI)) { 1115 if (len < sizeof(pi)) 1116 return -EINVAL; 1117 len -= sizeof(pi); 1118 1119 n = copy_from_iter(&pi, sizeof(pi), from); 1120 if (n != sizeof(pi)) 1121 return -EFAULT; 1122 } 1123 1124 if (tun->flags & IFF_VNET_HDR) { 1125 if (len < tun->vnet_hdr_sz) 1126 return -EINVAL; 1127 len -= tun->vnet_hdr_sz; 1128 1129 n = copy_from_iter(&gso, sizeof(gso), from); 1130 if (n != sizeof(gso)) 1131 return -EFAULT; 1132 1133 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 1134 tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2 > tun16_to_cpu(tun, gso.hdr_len)) 1135 gso.hdr_len = cpu_to_tun16(tun, tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2); 1136 1137 if (tun16_to_cpu(tun, gso.hdr_len) > len) 1138 return -EINVAL; 1139 iov_iter_advance(from, tun->vnet_hdr_sz - sizeof(gso)); 1140 } 1141 1142 if ((tun->flags & TUN_TYPE_MASK) == IFF_TAP) { 1143 align += NET_IP_ALIGN; 1144 if (unlikely(len < ETH_HLEN || 1145 (gso.hdr_len && tun16_to_cpu(tun, gso.hdr_len) < ETH_HLEN))) 1146 return -EINVAL; 1147 } 1148 1149 good_linear = SKB_MAX_HEAD(align); 1150 1151 if (msg_control) { 1152 struct iov_iter i = *from; 1153 1154 /* There are 256 bytes to be copied in skb, so there is 1155 * enough room for skb expand head in case it is used. 1156 * The rest of the buffer is mapped from userspace. 1157 */ 1158 copylen = gso.hdr_len ? tun16_to_cpu(tun, gso.hdr_len) : GOODCOPY_LEN; 1159 if (copylen > good_linear) 1160 copylen = good_linear; 1161 linear = copylen; 1162 iov_iter_advance(&i, copylen); 1163 if (iov_iter_npages(&i, INT_MAX) <= MAX_SKB_FRAGS) 1164 zerocopy = true; 1165 } 1166 1167 if (!zerocopy) { 1168 copylen = len; 1169 if (tun16_to_cpu(tun, gso.hdr_len) > good_linear) 1170 linear = good_linear; 1171 else 1172 linear = tun16_to_cpu(tun, gso.hdr_len); 1173 } 1174 1175 skb = tun_alloc_skb(tfile, align, copylen, linear, noblock); 1176 if (IS_ERR(skb)) { 1177 if (PTR_ERR(skb) != -EAGAIN) 1178 tun->dev->stats.rx_dropped++; 1179 return PTR_ERR(skb); 1180 } 1181 1182 if (zerocopy) 1183 err = zerocopy_sg_from_iter(skb, from); 1184 else { 1185 err = skb_copy_datagram_from_iter(skb, 0, from, len); 1186 if (!err && msg_control) { 1187 struct ubuf_info *uarg = msg_control; 1188 uarg->callback(uarg, false); 1189 } 1190 } 1191 1192 if (err) { 1193 tun->dev->stats.rx_dropped++; 1194 kfree_skb(skb); 1195 return -EFAULT; 1196 } 1197 1198 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 1199 if (!skb_partial_csum_set(skb, tun16_to_cpu(tun, gso.csum_start), 1200 tun16_to_cpu(tun, gso.csum_offset))) { 1201 tun->dev->stats.rx_frame_errors++; 1202 kfree_skb(skb); 1203 return -EINVAL; 1204 } 1205 } 1206 1207 switch (tun->flags & TUN_TYPE_MASK) { 1208 case IFF_TUN: 1209 if (tun->flags & IFF_NO_PI) { 1210 switch (skb->data[0] & 0xf0) { 1211 case 0x40: 1212 pi.proto = htons(ETH_P_IP); 1213 break; 1214 case 0x60: 1215 pi.proto = htons(ETH_P_IPV6); 1216 break; 1217 default: 1218 tun->dev->stats.rx_dropped++; 1219 kfree_skb(skb); 1220 return -EINVAL; 1221 } 1222 } 1223 1224 skb_reset_mac_header(skb); 1225 skb->protocol = pi.proto; 1226 skb->dev = tun->dev; 1227 break; 1228 case IFF_TAP: 1229 skb->protocol = eth_type_trans(skb, tun->dev); 1230 break; 1231 } 1232 1233 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 1234 pr_debug("GSO!\n"); 1235 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 1236 case VIRTIO_NET_HDR_GSO_TCPV4: 1237 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; 1238 break; 1239 case VIRTIO_NET_HDR_GSO_TCPV6: 1240 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; 1241 break; 1242 case VIRTIO_NET_HDR_GSO_UDP: 1243 skb_shinfo(skb)->gso_type = SKB_GSO_UDP; 1244 break; 1245 default: 1246 tun->dev->stats.rx_frame_errors++; 1247 kfree_skb(skb); 1248 return -EINVAL; 1249 } 1250 1251 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN) 1252 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; 1253 1254 skb_shinfo(skb)->gso_size = tun16_to_cpu(tun, gso.gso_size); 1255 if (skb_shinfo(skb)->gso_size == 0) { 1256 tun->dev->stats.rx_frame_errors++; 1257 kfree_skb(skb); 1258 return -EINVAL; 1259 } 1260 1261 /* Header must be checked, and gso_segs computed. */ 1262 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 1263 skb_shinfo(skb)->gso_segs = 0; 1264 } 1265 1266 /* copy skb_ubuf_info for callback when skb has no error */ 1267 if (zerocopy) { 1268 skb_shinfo(skb)->destructor_arg = msg_control; 1269 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY; 1270 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG; 1271 } 1272 1273 skb_reset_network_header(skb); 1274 skb_probe_transport_header(skb, 0); 1275 1276 rxhash = skb_get_hash(skb); 1277 netif_rx_ni(skb); 1278 1279 tun->dev->stats.rx_packets++; 1280 tun->dev->stats.rx_bytes += len; 1281 1282 tun_flow_update(tun, rxhash, tfile); 1283 return total_len; 1284 } 1285 1286 static ssize_t tun_chr_write_iter(struct kiocb *iocb, struct iov_iter *from) 1287 { 1288 struct file *file = iocb->ki_filp; 1289 struct tun_struct *tun = tun_get(file); 1290 struct tun_file *tfile = file->private_data; 1291 ssize_t result; 1292 1293 if (!tun) 1294 return -EBADFD; 1295 1296 result = tun_get_user(tun, tfile, NULL, from, file->f_flags & O_NONBLOCK); 1297 1298 tun_put(tun); 1299 return result; 1300 } 1301 1302 /* Put packet to the user space buffer */ 1303 static ssize_t tun_put_user(struct tun_struct *tun, 1304 struct tun_file *tfile, 1305 struct sk_buff *skb, 1306 struct iov_iter *iter) 1307 { 1308 struct tun_pi pi = { 0, skb->protocol }; 1309 ssize_t total; 1310 int vlan_offset = 0; 1311 int vlan_hlen = 0; 1312 int vnet_hdr_sz = 0; 1313 1314 if (skb_vlan_tag_present(skb)) 1315 vlan_hlen = VLAN_HLEN; 1316 1317 if (tun->flags & IFF_VNET_HDR) 1318 vnet_hdr_sz = tun->vnet_hdr_sz; 1319 1320 total = skb->len + vlan_hlen + vnet_hdr_sz; 1321 1322 if (!(tun->flags & IFF_NO_PI)) { 1323 if (iov_iter_count(iter) < sizeof(pi)) 1324 return -EINVAL; 1325 1326 total += sizeof(pi); 1327 if (iov_iter_count(iter) < total) { 1328 /* Packet will be striped */ 1329 pi.flags |= TUN_PKT_STRIP; 1330 } 1331 1332 if (copy_to_iter(&pi, sizeof(pi), iter) != sizeof(pi)) 1333 return -EFAULT; 1334 } 1335 1336 if (vnet_hdr_sz) { 1337 struct virtio_net_hdr gso = { 0 }; /* no info leak */ 1338 if (iov_iter_count(iter) < vnet_hdr_sz) 1339 return -EINVAL; 1340 1341 if (skb_is_gso(skb)) { 1342 struct skb_shared_info *sinfo = skb_shinfo(skb); 1343 1344 /* This is a hint as to how much should be linear. */ 1345 gso.hdr_len = cpu_to_tun16(tun, skb_headlen(skb)); 1346 gso.gso_size = cpu_to_tun16(tun, sinfo->gso_size); 1347 if (sinfo->gso_type & SKB_GSO_TCPV4) 1348 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 1349 else if (sinfo->gso_type & SKB_GSO_TCPV6) 1350 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 1351 else if (sinfo->gso_type & SKB_GSO_UDP) 1352 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP; 1353 else { 1354 pr_err("unexpected GSO type: " 1355 "0x%x, gso_size %d, hdr_len %d\n", 1356 sinfo->gso_type, tun16_to_cpu(tun, gso.gso_size), 1357 tun16_to_cpu(tun, gso.hdr_len)); 1358 print_hex_dump(KERN_ERR, "tun: ", 1359 DUMP_PREFIX_NONE, 1360 16, 1, skb->head, 1361 min((int)tun16_to_cpu(tun, gso.hdr_len), 64), true); 1362 WARN_ON_ONCE(1); 1363 return -EINVAL; 1364 } 1365 if (sinfo->gso_type & SKB_GSO_TCP_ECN) 1366 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 1367 } else 1368 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE; 1369 1370 if (skb->ip_summed == CHECKSUM_PARTIAL) { 1371 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 1372 gso.csum_start = cpu_to_tun16(tun, skb_checksum_start_offset(skb) + 1373 vlan_hlen); 1374 gso.csum_offset = cpu_to_tun16(tun, skb->csum_offset); 1375 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 1376 gso.flags = VIRTIO_NET_HDR_F_DATA_VALID; 1377 } /* else everything is zero */ 1378 1379 if (copy_to_iter(&gso, sizeof(gso), iter) != sizeof(gso)) 1380 return -EFAULT; 1381 1382 iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso)); 1383 } 1384 1385 if (vlan_hlen) { 1386 int ret; 1387 struct { 1388 __be16 h_vlan_proto; 1389 __be16 h_vlan_TCI; 1390 } veth; 1391 1392 veth.h_vlan_proto = skb->vlan_proto; 1393 veth.h_vlan_TCI = htons(skb_vlan_tag_get(skb)); 1394 1395 vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto); 1396 1397 ret = skb_copy_datagram_iter(skb, 0, iter, vlan_offset); 1398 if (ret || !iov_iter_count(iter)) 1399 goto done; 1400 1401 ret = copy_to_iter(&veth, sizeof(veth), iter); 1402 if (ret != sizeof(veth) || !iov_iter_count(iter)) 1403 goto done; 1404 } 1405 1406 skb_copy_datagram_iter(skb, vlan_offset, iter, skb->len - vlan_offset); 1407 1408 done: 1409 tun->dev->stats.tx_packets++; 1410 tun->dev->stats.tx_bytes += skb->len + vlan_hlen; 1411 1412 return total; 1413 } 1414 1415 static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile, 1416 struct iov_iter *to, 1417 int noblock) 1418 { 1419 struct sk_buff *skb; 1420 ssize_t ret; 1421 int peeked, err, off = 0; 1422 1423 tun_debug(KERN_INFO, tun, "tun_do_read\n"); 1424 1425 if (!iov_iter_count(to)) 1426 return 0; 1427 1428 if (tun->dev->reg_state != NETREG_REGISTERED) 1429 return -EIO; 1430 1431 /* Read frames from queue */ 1432 skb = __skb_recv_datagram(tfile->socket.sk, noblock ? MSG_DONTWAIT : 0, 1433 &peeked, &off, &err); 1434 if (!skb) 1435 return err; 1436 1437 ret = tun_put_user(tun, tfile, skb, to); 1438 if (unlikely(ret < 0)) 1439 kfree_skb(skb); 1440 else 1441 consume_skb(skb); 1442 1443 return ret; 1444 } 1445 1446 static ssize_t tun_chr_read_iter(struct kiocb *iocb, struct iov_iter *to) 1447 { 1448 struct file *file = iocb->ki_filp; 1449 struct tun_file *tfile = file->private_data; 1450 struct tun_struct *tun = __tun_get(tfile); 1451 ssize_t len = iov_iter_count(to), ret; 1452 1453 if (!tun) 1454 return -EBADFD; 1455 ret = tun_do_read(tun, tfile, to, file->f_flags & O_NONBLOCK); 1456 ret = min_t(ssize_t, ret, len); 1457 if (ret > 0) 1458 iocb->ki_pos = ret; 1459 tun_put(tun); 1460 return ret; 1461 } 1462 1463 static void tun_free_netdev(struct net_device *dev) 1464 { 1465 struct tun_struct *tun = netdev_priv(dev); 1466 1467 BUG_ON(!(list_empty(&tun->disabled))); 1468 tun_flow_uninit(tun); 1469 security_tun_dev_free_security(tun->security); 1470 free_netdev(dev); 1471 } 1472 1473 static void tun_setup(struct net_device *dev) 1474 { 1475 struct tun_struct *tun = netdev_priv(dev); 1476 1477 tun->owner = INVALID_UID; 1478 tun->group = INVALID_GID; 1479 1480 dev->ethtool_ops = &tun_ethtool_ops; 1481 dev->destructor = tun_free_netdev; 1482 /* We prefer our own queue length */ 1483 dev->tx_queue_len = TUN_READQ_SIZE; 1484 } 1485 1486 /* Trivial set of netlink ops to allow deleting tun or tap 1487 * device with netlink. 1488 */ 1489 static int tun_validate(struct nlattr *tb[], struct nlattr *data[]) 1490 { 1491 return -EINVAL; 1492 } 1493 1494 static struct rtnl_link_ops tun_link_ops __read_mostly = { 1495 .kind = DRV_NAME, 1496 .priv_size = sizeof(struct tun_struct), 1497 .setup = tun_setup, 1498 .validate = tun_validate, 1499 }; 1500 1501 static void tun_sock_write_space(struct sock *sk) 1502 { 1503 struct tun_file *tfile; 1504 wait_queue_head_t *wqueue; 1505 1506 if (!sock_writeable(sk)) 1507 return; 1508 1509 if (!test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags)) 1510 return; 1511 1512 wqueue = sk_sleep(sk); 1513 if (wqueue && waitqueue_active(wqueue)) 1514 wake_up_interruptible_sync_poll(wqueue, POLLOUT | 1515 POLLWRNORM | POLLWRBAND); 1516 1517 tfile = container_of(sk, struct tun_file, sk); 1518 kill_fasync(&tfile->fasync, SIGIO, POLL_OUT); 1519 } 1520 1521 static int tun_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len) 1522 { 1523 int ret; 1524 struct tun_file *tfile = container_of(sock, struct tun_file, socket); 1525 struct tun_struct *tun = __tun_get(tfile); 1526 1527 if (!tun) 1528 return -EBADFD; 1529 1530 ret = tun_get_user(tun, tfile, m->msg_control, &m->msg_iter, 1531 m->msg_flags & MSG_DONTWAIT); 1532 tun_put(tun); 1533 return ret; 1534 } 1535 1536 static int tun_recvmsg(struct socket *sock, struct msghdr *m, size_t total_len, 1537 int flags) 1538 { 1539 struct tun_file *tfile = container_of(sock, struct tun_file, socket); 1540 struct tun_struct *tun = __tun_get(tfile); 1541 int ret; 1542 1543 if (!tun) 1544 return -EBADFD; 1545 1546 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC|MSG_ERRQUEUE)) { 1547 ret = -EINVAL; 1548 goto out; 1549 } 1550 if (flags & MSG_ERRQUEUE) { 1551 ret = sock_recv_errqueue(sock->sk, m, total_len, 1552 SOL_PACKET, TUN_TX_TIMESTAMP); 1553 goto out; 1554 } 1555 ret = tun_do_read(tun, tfile, &m->msg_iter, flags & MSG_DONTWAIT); 1556 if (ret > (ssize_t)total_len) { 1557 m->msg_flags |= MSG_TRUNC; 1558 ret = flags & MSG_TRUNC ? ret : total_len; 1559 } 1560 out: 1561 tun_put(tun); 1562 return ret; 1563 } 1564 1565 /* Ops structure to mimic raw sockets with tun */ 1566 static const struct proto_ops tun_socket_ops = { 1567 .sendmsg = tun_sendmsg, 1568 .recvmsg = tun_recvmsg, 1569 }; 1570 1571 static struct proto tun_proto = { 1572 .name = "tun", 1573 .owner = THIS_MODULE, 1574 .obj_size = sizeof(struct tun_file), 1575 }; 1576 1577 static int tun_flags(struct tun_struct *tun) 1578 { 1579 return tun->flags & (TUN_FEATURES | IFF_PERSIST | IFF_TUN | IFF_TAP); 1580 } 1581 1582 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr, 1583 char *buf) 1584 { 1585 struct tun_struct *tun = netdev_priv(to_net_dev(dev)); 1586 return sprintf(buf, "0x%x\n", tun_flags(tun)); 1587 } 1588 1589 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr, 1590 char *buf) 1591 { 1592 struct tun_struct *tun = netdev_priv(to_net_dev(dev)); 1593 return uid_valid(tun->owner)? 1594 sprintf(buf, "%u\n", 1595 from_kuid_munged(current_user_ns(), tun->owner)): 1596 sprintf(buf, "-1\n"); 1597 } 1598 1599 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr, 1600 char *buf) 1601 { 1602 struct tun_struct *tun = netdev_priv(to_net_dev(dev)); 1603 return gid_valid(tun->group) ? 1604 sprintf(buf, "%u\n", 1605 from_kgid_munged(current_user_ns(), tun->group)): 1606 sprintf(buf, "-1\n"); 1607 } 1608 1609 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL); 1610 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL); 1611 static DEVICE_ATTR(group, 0444, tun_show_group, NULL); 1612 1613 static struct attribute *tun_dev_attrs[] = { 1614 &dev_attr_tun_flags.attr, 1615 &dev_attr_owner.attr, 1616 &dev_attr_group.attr, 1617 NULL 1618 }; 1619 1620 static const struct attribute_group tun_attr_group = { 1621 .attrs = tun_dev_attrs 1622 }; 1623 1624 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) 1625 { 1626 struct tun_struct *tun; 1627 struct tun_file *tfile = file->private_data; 1628 struct net_device *dev; 1629 int err; 1630 1631 if (tfile->detached) 1632 return -EINVAL; 1633 1634 dev = __dev_get_by_name(net, ifr->ifr_name); 1635 if (dev) { 1636 if (ifr->ifr_flags & IFF_TUN_EXCL) 1637 return -EBUSY; 1638 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops) 1639 tun = netdev_priv(dev); 1640 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops) 1641 tun = netdev_priv(dev); 1642 else 1643 return -EINVAL; 1644 1645 if (!!(ifr->ifr_flags & IFF_MULTI_QUEUE) != 1646 !!(tun->flags & IFF_MULTI_QUEUE)) 1647 return -EINVAL; 1648 1649 if (tun_not_capable(tun)) 1650 return -EPERM; 1651 err = security_tun_dev_open(tun->security); 1652 if (err < 0) 1653 return err; 1654 1655 err = tun_attach(tun, file, ifr->ifr_flags & IFF_NOFILTER); 1656 if (err < 0) 1657 return err; 1658 1659 if (tun->flags & IFF_MULTI_QUEUE && 1660 (tun->numqueues + tun->numdisabled > 1)) { 1661 /* One or more queue has already been attached, no need 1662 * to initialize the device again. 1663 */ 1664 return 0; 1665 } 1666 } 1667 else { 1668 char *name; 1669 unsigned long flags = 0; 1670 int queues = ifr->ifr_flags & IFF_MULTI_QUEUE ? 1671 MAX_TAP_QUEUES : 1; 1672 1673 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1674 return -EPERM; 1675 err = security_tun_dev_create(); 1676 if (err < 0) 1677 return err; 1678 1679 /* Set dev type */ 1680 if (ifr->ifr_flags & IFF_TUN) { 1681 /* TUN device */ 1682 flags |= IFF_TUN; 1683 name = "tun%d"; 1684 } else if (ifr->ifr_flags & IFF_TAP) { 1685 /* TAP device */ 1686 flags |= IFF_TAP; 1687 name = "tap%d"; 1688 } else 1689 return -EINVAL; 1690 1691 if (*ifr->ifr_name) 1692 name = ifr->ifr_name; 1693 1694 dev = alloc_netdev_mqs(sizeof(struct tun_struct), name, 1695 NET_NAME_UNKNOWN, tun_setup, queues, 1696 queues); 1697 1698 if (!dev) 1699 return -ENOMEM; 1700 1701 dev_net_set(dev, net); 1702 dev->rtnl_link_ops = &tun_link_ops; 1703 dev->ifindex = tfile->ifindex; 1704 dev->sysfs_groups[0] = &tun_attr_group; 1705 1706 tun = netdev_priv(dev); 1707 tun->dev = dev; 1708 tun->flags = flags; 1709 tun->txflt.count = 0; 1710 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr); 1711 1712 tun->align = NET_SKB_PAD; 1713 tun->filter_attached = false; 1714 tun->sndbuf = tfile->socket.sk->sk_sndbuf; 1715 1716 spin_lock_init(&tun->lock); 1717 1718 err = security_tun_dev_alloc_security(&tun->security); 1719 if (err < 0) 1720 goto err_free_dev; 1721 1722 tun_net_init(dev); 1723 tun_flow_init(tun); 1724 1725 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | 1726 TUN_USER_FEATURES | NETIF_F_HW_VLAN_CTAG_TX | 1727 NETIF_F_HW_VLAN_STAG_TX; 1728 dev->features = dev->hw_features; 1729 dev->vlan_features = dev->features & 1730 ~(NETIF_F_HW_VLAN_CTAG_TX | 1731 NETIF_F_HW_VLAN_STAG_TX); 1732 1733 INIT_LIST_HEAD(&tun->disabled); 1734 err = tun_attach(tun, file, false); 1735 if (err < 0) 1736 goto err_free_flow; 1737 1738 err = register_netdevice(tun->dev); 1739 if (err < 0) 1740 goto err_detach; 1741 } 1742 1743 netif_carrier_on(tun->dev); 1744 1745 tun_debug(KERN_INFO, tun, "tun_set_iff\n"); 1746 1747 tun->flags = (tun->flags & ~TUN_FEATURES) | 1748 (ifr->ifr_flags & TUN_FEATURES); 1749 1750 /* Make sure persistent devices do not get stuck in 1751 * xoff state. 1752 */ 1753 if (netif_running(tun->dev)) 1754 netif_tx_wake_all_queues(tun->dev); 1755 1756 strcpy(ifr->ifr_name, tun->dev->name); 1757 return 0; 1758 1759 err_detach: 1760 tun_detach_all(dev); 1761 err_free_flow: 1762 tun_flow_uninit(tun); 1763 security_tun_dev_free_security(tun->security); 1764 err_free_dev: 1765 free_netdev(dev); 1766 return err; 1767 } 1768 1769 static void tun_get_iff(struct net *net, struct tun_struct *tun, 1770 struct ifreq *ifr) 1771 { 1772 tun_debug(KERN_INFO, tun, "tun_get_iff\n"); 1773 1774 strcpy(ifr->ifr_name, tun->dev->name); 1775 1776 ifr->ifr_flags = tun_flags(tun); 1777 1778 } 1779 1780 /* This is like a cut-down ethtool ops, except done via tun fd so no 1781 * privs required. */ 1782 static int set_offload(struct tun_struct *tun, unsigned long arg) 1783 { 1784 netdev_features_t features = 0; 1785 1786 if (arg & TUN_F_CSUM) { 1787 features |= NETIF_F_HW_CSUM; 1788 arg &= ~TUN_F_CSUM; 1789 1790 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) { 1791 if (arg & TUN_F_TSO_ECN) { 1792 features |= NETIF_F_TSO_ECN; 1793 arg &= ~TUN_F_TSO_ECN; 1794 } 1795 if (arg & TUN_F_TSO4) 1796 features |= NETIF_F_TSO; 1797 if (arg & TUN_F_TSO6) 1798 features |= NETIF_F_TSO6; 1799 arg &= ~(TUN_F_TSO4|TUN_F_TSO6); 1800 } 1801 1802 if (arg & TUN_F_UFO) { 1803 features |= NETIF_F_UFO; 1804 arg &= ~TUN_F_UFO; 1805 } 1806 } 1807 1808 /* This gives the user a way to test for new features in future by 1809 * trying to set them. */ 1810 if (arg) 1811 return -EINVAL; 1812 1813 tun->set_features = features; 1814 netdev_update_features(tun->dev); 1815 1816 return 0; 1817 } 1818 1819 static void tun_detach_filter(struct tun_struct *tun, int n) 1820 { 1821 int i; 1822 struct tun_file *tfile; 1823 1824 for (i = 0; i < n; i++) { 1825 tfile = rtnl_dereference(tun->tfiles[i]); 1826 __sk_detach_filter(tfile->socket.sk, lockdep_rtnl_is_held()); 1827 } 1828 1829 tun->filter_attached = false; 1830 } 1831 1832 static int tun_attach_filter(struct tun_struct *tun) 1833 { 1834 int i, ret = 0; 1835 struct tun_file *tfile; 1836 1837 for (i = 0; i < tun->numqueues; i++) { 1838 tfile = rtnl_dereference(tun->tfiles[i]); 1839 ret = __sk_attach_filter(&tun->fprog, tfile->socket.sk, 1840 lockdep_rtnl_is_held()); 1841 if (ret) { 1842 tun_detach_filter(tun, i); 1843 return ret; 1844 } 1845 } 1846 1847 tun->filter_attached = true; 1848 return ret; 1849 } 1850 1851 static void tun_set_sndbuf(struct tun_struct *tun) 1852 { 1853 struct tun_file *tfile; 1854 int i; 1855 1856 for (i = 0; i < tun->numqueues; i++) { 1857 tfile = rtnl_dereference(tun->tfiles[i]); 1858 tfile->socket.sk->sk_sndbuf = tun->sndbuf; 1859 } 1860 } 1861 1862 static int tun_set_queue(struct file *file, struct ifreq *ifr) 1863 { 1864 struct tun_file *tfile = file->private_data; 1865 struct tun_struct *tun; 1866 int ret = 0; 1867 1868 rtnl_lock(); 1869 1870 if (ifr->ifr_flags & IFF_ATTACH_QUEUE) { 1871 tun = tfile->detached; 1872 if (!tun) { 1873 ret = -EINVAL; 1874 goto unlock; 1875 } 1876 ret = security_tun_dev_attach_queue(tun->security); 1877 if (ret < 0) 1878 goto unlock; 1879 ret = tun_attach(tun, file, false); 1880 } else if (ifr->ifr_flags & IFF_DETACH_QUEUE) { 1881 tun = rtnl_dereference(tfile->tun); 1882 if (!tun || !(tun->flags & IFF_MULTI_QUEUE) || tfile->detached) 1883 ret = -EINVAL; 1884 else 1885 __tun_detach(tfile, false); 1886 } else 1887 ret = -EINVAL; 1888 1889 unlock: 1890 rtnl_unlock(); 1891 return ret; 1892 } 1893 1894 static long __tun_chr_ioctl(struct file *file, unsigned int cmd, 1895 unsigned long arg, int ifreq_len) 1896 { 1897 struct tun_file *tfile = file->private_data; 1898 struct tun_struct *tun; 1899 void __user* argp = (void __user*)arg; 1900 struct ifreq ifr; 1901 kuid_t owner; 1902 kgid_t group; 1903 int sndbuf; 1904 int vnet_hdr_sz; 1905 unsigned int ifindex; 1906 int le; 1907 int ret; 1908 1909 if (cmd == TUNSETIFF || cmd == TUNSETQUEUE || _IOC_TYPE(cmd) == 0x89) { 1910 if (copy_from_user(&ifr, argp, ifreq_len)) 1911 return -EFAULT; 1912 } else { 1913 memset(&ifr, 0, sizeof(ifr)); 1914 } 1915 if (cmd == TUNGETFEATURES) { 1916 /* Currently this just means: "what IFF flags are valid?". 1917 * This is needed because we never checked for invalid flags on 1918 * TUNSETIFF. 1919 */ 1920 return put_user(IFF_TUN | IFF_TAP | TUN_FEATURES, 1921 (unsigned int __user*)argp); 1922 } else if (cmd == TUNSETQUEUE) 1923 return tun_set_queue(file, &ifr); 1924 1925 ret = 0; 1926 rtnl_lock(); 1927 1928 tun = __tun_get(tfile); 1929 if (cmd == TUNSETIFF && !tun) { 1930 ifr.ifr_name[IFNAMSIZ-1] = '\0'; 1931 1932 ret = tun_set_iff(sock_net(&tfile->sk), file, &ifr); 1933 1934 if (ret) 1935 goto unlock; 1936 1937 if (copy_to_user(argp, &ifr, ifreq_len)) 1938 ret = -EFAULT; 1939 goto unlock; 1940 } 1941 if (cmd == TUNSETIFINDEX) { 1942 ret = -EPERM; 1943 if (tun) 1944 goto unlock; 1945 1946 ret = -EFAULT; 1947 if (copy_from_user(&ifindex, argp, sizeof(ifindex))) 1948 goto unlock; 1949 1950 ret = 0; 1951 tfile->ifindex = ifindex; 1952 goto unlock; 1953 } 1954 1955 ret = -EBADFD; 1956 if (!tun) 1957 goto unlock; 1958 1959 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %u\n", cmd); 1960 1961 ret = 0; 1962 switch (cmd) { 1963 case TUNGETIFF: 1964 tun_get_iff(current->nsproxy->net_ns, tun, &ifr); 1965 1966 if (tfile->detached) 1967 ifr.ifr_flags |= IFF_DETACH_QUEUE; 1968 if (!tfile->socket.sk->sk_filter) 1969 ifr.ifr_flags |= IFF_NOFILTER; 1970 1971 if (copy_to_user(argp, &ifr, ifreq_len)) 1972 ret = -EFAULT; 1973 break; 1974 1975 case TUNSETNOCSUM: 1976 /* Disable/Enable checksum */ 1977 1978 /* [unimplemented] */ 1979 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n", 1980 arg ? "disabled" : "enabled"); 1981 break; 1982 1983 case TUNSETPERSIST: 1984 /* Disable/Enable persist mode. Keep an extra reference to the 1985 * module to prevent the module being unprobed. 1986 */ 1987 if (arg && !(tun->flags & IFF_PERSIST)) { 1988 tun->flags |= IFF_PERSIST; 1989 __module_get(THIS_MODULE); 1990 } 1991 if (!arg && (tun->flags & IFF_PERSIST)) { 1992 tun->flags &= ~IFF_PERSIST; 1993 module_put(THIS_MODULE); 1994 } 1995 1996 tun_debug(KERN_INFO, tun, "persist %s\n", 1997 arg ? "enabled" : "disabled"); 1998 break; 1999 2000 case TUNSETOWNER: 2001 /* Set owner of the device */ 2002 owner = make_kuid(current_user_ns(), arg); 2003 if (!uid_valid(owner)) { 2004 ret = -EINVAL; 2005 break; 2006 } 2007 tun->owner = owner; 2008 tun_debug(KERN_INFO, tun, "owner set to %u\n", 2009 from_kuid(&init_user_ns, tun->owner)); 2010 break; 2011 2012 case TUNSETGROUP: 2013 /* Set group of the device */ 2014 group = make_kgid(current_user_ns(), arg); 2015 if (!gid_valid(group)) { 2016 ret = -EINVAL; 2017 break; 2018 } 2019 tun->group = group; 2020 tun_debug(KERN_INFO, tun, "group set to %u\n", 2021 from_kgid(&init_user_ns, tun->group)); 2022 break; 2023 2024 case TUNSETLINK: 2025 /* Only allow setting the type when the interface is down */ 2026 if (tun->dev->flags & IFF_UP) { 2027 tun_debug(KERN_INFO, tun, 2028 "Linktype set failed because interface is up\n"); 2029 ret = -EBUSY; 2030 } else { 2031 tun->dev->type = (int) arg; 2032 tun_debug(KERN_INFO, tun, "linktype set to %d\n", 2033 tun->dev->type); 2034 ret = 0; 2035 } 2036 break; 2037 2038 #ifdef TUN_DEBUG 2039 case TUNSETDEBUG: 2040 tun->debug = arg; 2041 break; 2042 #endif 2043 case TUNSETOFFLOAD: 2044 ret = set_offload(tun, arg); 2045 break; 2046 2047 case TUNSETTXFILTER: 2048 /* Can be set only for TAPs */ 2049 ret = -EINVAL; 2050 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP) 2051 break; 2052 ret = update_filter(&tun->txflt, (void __user *)arg); 2053 break; 2054 2055 case SIOCGIFHWADDR: 2056 /* Get hw address */ 2057 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN); 2058 ifr.ifr_hwaddr.sa_family = tun->dev->type; 2059 if (copy_to_user(argp, &ifr, ifreq_len)) 2060 ret = -EFAULT; 2061 break; 2062 2063 case SIOCSIFHWADDR: 2064 /* Set hw address */ 2065 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n", 2066 ifr.ifr_hwaddr.sa_data); 2067 2068 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr); 2069 break; 2070 2071 case TUNGETSNDBUF: 2072 sndbuf = tfile->socket.sk->sk_sndbuf; 2073 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf))) 2074 ret = -EFAULT; 2075 break; 2076 2077 case TUNSETSNDBUF: 2078 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) { 2079 ret = -EFAULT; 2080 break; 2081 } 2082 2083 tun->sndbuf = sndbuf; 2084 tun_set_sndbuf(tun); 2085 break; 2086 2087 case TUNGETVNETHDRSZ: 2088 vnet_hdr_sz = tun->vnet_hdr_sz; 2089 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz))) 2090 ret = -EFAULT; 2091 break; 2092 2093 case TUNSETVNETHDRSZ: 2094 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) { 2095 ret = -EFAULT; 2096 break; 2097 } 2098 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) { 2099 ret = -EINVAL; 2100 break; 2101 } 2102 2103 tun->vnet_hdr_sz = vnet_hdr_sz; 2104 break; 2105 2106 case TUNGETVNETLE: 2107 le = !!(tun->flags & TUN_VNET_LE); 2108 if (put_user(le, (int __user *)argp)) 2109 ret = -EFAULT; 2110 break; 2111 2112 case TUNSETVNETLE: 2113 if (get_user(le, (int __user *)argp)) { 2114 ret = -EFAULT; 2115 break; 2116 } 2117 if (le) 2118 tun->flags |= TUN_VNET_LE; 2119 else 2120 tun->flags &= ~TUN_VNET_LE; 2121 break; 2122 2123 case TUNGETVNETBE: 2124 ret = tun_get_vnet_be(tun, argp); 2125 break; 2126 2127 case TUNSETVNETBE: 2128 ret = tun_set_vnet_be(tun, argp); 2129 break; 2130 2131 case TUNATTACHFILTER: 2132 /* Can be set only for TAPs */ 2133 ret = -EINVAL; 2134 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP) 2135 break; 2136 ret = -EFAULT; 2137 if (copy_from_user(&tun->fprog, argp, sizeof(tun->fprog))) 2138 break; 2139 2140 ret = tun_attach_filter(tun); 2141 break; 2142 2143 case TUNDETACHFILTER: 2144 /* Can be set only for TAPs */ 2145 ret = -EINVAL; 2146 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP) 2147 break; 2148 ret = 0; 2149 tun_detach_filter(tun, tun->numqueues); 2150 break; 2151 2152 case TUNGETFILTER: 2153 ret = -EINVAL; 2154 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP) 2155 break; 2156 ret = -EFAULT; 2157 if (copy_to_user(argp, &tun->fprog, sizeof(tun->fprog))) 2158 break; 2159 ret = 0; 2160 break; 2161 2162 default: 2163 ret = -EINVAL; 2164 break; 2165 } 2166 2167 unlock: 2168 rtnl_unlock(); 2169 if (tun) 2170 tun_put(tun); 2171 return ret; 2172 } 2173 2174 static long tun_chr_ioctl(struct file *file, 2175 unsigned int cmd, unsigned long arg) 2176 { 2177 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq)); 2178 } 2179 2180 #ifdef CONFIG_COMPAT 2181 static long tun_chr_compat_ioctl(struct file *file, 2182 unsigned int cmd, unsigned long arg) 2183 { 2184 switch (cmd) { 2185 case TUNSETIFF: 2186 case TUNGETIFF: 2187 case TUNSETTXFILTER: 2188 case TUNGETSNDBUF: 2189 case TUNSETSNDBUF: 2190 case SIOCGIFHWADDR: 2191 case SIOCSIFHWADDR: 2192 arg = (unsigned long)compat_ptr(arg); 2193 break; 2194 default: 2195 arg = (compat_ulong_t)arg; 2196 break; 2197 } 2198 2199 /* 2200 * compat_ifreq is shorter than ifreq, so we must not access beyond 2201 * the end of that structure. All fields that are used in this 2202 * driver are compatible though, we don't need to convert the 2203 * contents. 2204 */ 2205 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq)); 2206 } 2207 #endif /* CONFIG_COMPAT */ 2208 2209 static int tun_chr_fasync(int fd, struct file *file, int on) 2210 { 2211 struct tun_file *tfile = file->private_data; 2212 int ret; 2213 2214 if ((ret = fasync_helper(fd, file, on, &tfile->fasync)) < 0) 2215 goto out; 2216 2217 if (on) { 2218 __f_setown(file, task_pid(current), PIDTYPE_PID, 0); 2219 tfile->flags |= TUN_FASYNC; 2220 } else 2221 tfile->flags &= ~TUN_FASYNC; 2222 ret = 0; 2223 out: 2224 return ret; 2225 } 2226 2227 static int tun_chr_open(struct inode *inode, struct file * file) 2228 { 2229 struct net *net = current->nsproxy->net_ns; 2230 struct tun_file *tfile; 2231 2232 DBG1(KERN_INFO, "tunX: tun_chr_open\n"); 2233 2234 tfile = (struct tun_file *)sk_alloc(net, AF_UNSPEC, GFP_KERNEL, 2235 &tun_proto, 0); 2236 if (!tfile) 2237 return -ENOMEM; 2238 RCU_INIT_POINTER(tfile->tun, NULL); 2239 tfile->flags = 0; 2240 tfile->ifindex = 0; 2241 2242 init_waitqueue_head(&tfile->wq.wait); 2243 RCU_INIT_POINTER(tfile->socket.wq, &tfile->wq); 2244 2245 tfile->socket.file = file; 2246 tfile->socket.ops = &tun_socket_ops; 2247 2248 sock_init_data(&tfile->socket, &tfile->sk); 2249 2250 tfile->sk.sk_write_space = tun_sock_write_space; 2251 tfile->sk.sk_sndbuf = INT_MAX; 2252 2253 file->private_data = tfile; 2254 INIT_LIST_HEAD(&tfile->next); 2255 2256 sock_set_flag(&tfile->sk, SOCK_ZEROCOPY); 2257 2258 return 0; 2259 } 2260 2261 static int tun_chr_close(struct inode *inode, struct file *file) 2262 { 2263 struct tun_file *tfile = file->private_data; 2264 2265 tun_detach(tfile, true); 2266 2267 return 0; 2268 } 2269 2270 #ifdef CONFIG_PROC_FS 2271 static void tun_chr_show_fdinfo(struct seq_file *m, struct file *f) 2272 { 2273 struct tun_struct *tun; 2274 struct ifreq ifr; 2275 2276 memset(&ifr, 0, sizeof(ifr)); 2277 2278 rtnl_lock(); 2279 tun = tun_get(f); 2280 if (tun) 2281 tun_get_iff(current->nsproxy->net_ns, tun, &ifr); 2282 rtnl_unlock(); 2283 2284 if (tun) 2285 tun_put(tun); 2286 2287 seq_printf(m, "iff:\t%s\n", ifr.ifr_name); 2288 } 2289 #endif 2290 2291 static const struct file_operations tun_fops = { 2292 .owner = THIS_MODULE, 2293 .llseek = no_llseek, 2294 .read_iter = tun_chr_read_iter, 2295 .write_iter = tun_chr_write_iter, 2296 .poll = tun_chr_poll, 2297 .unlocked_ioctl = tun_chr_ioctl, 2298 #ifdef CONFIG_COMPAT 2299 .compat_ioctl = tun_chr_compat_ioctl, 2300 #endif 2301 .open = tun_chr_open, 2302 .release = tun_chr_close, 2303 .fasync = tun_chr_fasync, 2304 #ifdef CONFIG_PROC_FS 2305 .show_fdinfo = tun_chr_show_fdinfo, 2306 #endif 2307 }; 2308 2309 static struct miscdevice tun_miscdev = { 2310 .minor = TUN_MINOR, 2311 .name = "tun", 2312 .nodename = "net/tun", 2313 .fops = &tun_fops, 2314 }; 2315 2316 /* ethtool interface */ 2317 2318 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd) 2319 { 2320 cmd->supported = 0; 2321 cmd->advertising = 0; 2322 ethtool_cmd_speed_set(cmd, SPEED_10); 2323 cmd->duplex = DUPLEX_FULL; 2324 cmd->port = PORT_TP; 2325 cmd->phy_address = 0; 2326 cmd->transceiver = XCVR_INTERNAL; 2327 cmd->autoneg = AUTONEG_DISABLE; 2328 cmd->maxtxpkt = 0; 2329 cmd->maxrxpkt = 0; 2330 return 0; 2331 } 2332 2333 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info) 2334 { 2335 struct tun_struct *tun = netdev_priv(dev); 2336 2337 strlcpy(info->driver, DRV_NAME, sizeof(info->driver)); 2338 strlcpy(info->version, DRV_VERSION, sizeof(info->version)); 2339 2340 switch (tun->flags & TUN_TYPE_MASK) { 2341 case IFF_TUN: 2342 strlcpy(info->bus_info, "tun", sizeof(info->bus_info)); 2343 break; 2344 case IFF_TAP: 2345 strlcpy(info->bus_info, "tap", sizeof(info->bus_info)); 2346 break; 2347 } 2348 } 2349 2350 static u32 tun_get_msglevel(struct net_device *dev) 2351 { 2352 #ifdef TUN_DEBUG 2353 struct tun_struct *tun = netdev_priv(dev); 2354 return tun->debug; 2355 #else 2356 return -EOPNOTSUPP; 2357 #endif 2358 } 2359 2360 static void tun_set_msglevel(struct net_device *dev, u32 value) 2361 { 2362 #ifdef TUN_DEBUG 2363 struct tun_struct *tun = netdev_priv(dev); 2364 tun->debug = value; 2365 #endif 2366 } 2367 2368 static const struct ethtool_ops tun_ethtool_ops = { 2369 .get_settings = tun_get_settings, 2370 .get_drvinfo = tun_get_drvinfo, 2371 .get_msglevel = tun_get_msglevel, 2372 .set_msglevel = tun_set_msglevel, 2373 .get_link = ethtool_op_get_link, 2374 .get_ts_info = ethtool_op_get_ts_info, 2375 }; 2376 2377 2378 static int __init tun_init(void) 2379 { 2380 int ret = 0; 2381 2382 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION); 2383 pr_info("%s\n", DRV_COPYRIGHT); 2384 2385 ret = rtnl_link_register(&tun_link_ops); 2386 if (ret) { 2387 pr_err("Can't register link_ops\n"); 2388 goto err_linkops; 2389 } 2390 2391 ret = misc_register(&tun_miscdev); 2392 if (ret) { 2393 pr_err("Can't register misc device %d\n", TUN_MINOR); 2394 goto err_misc; 2395 } 2396 return 0; 2397 err_misc: 2398 rtnl_link_unregister(&tun_link_ops); 2399 err_linkops: 2400 return ret; 2401 } 2402 2403 static void tun_cleanup(void) 2404 { 2405 misc_deregister(&tun_miscdev); 2406 rtnl_link_unregister(&tun_link_ops); 2407 } 2408 2409 /* Get an underlying socket object from tun file. Returns error unless file is 2410 * attached to a device. The returned object works like a packet socket, it 2411 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for 2412 * holding a reference to the file for as long as the socket is in use. */ 2413 struct socket *tun_get_socket(struct file *file) 2414 { 2415 struct tun_file *tfile; 2416 if (file->f_op != &tun_fops) 2417 return ERR_PTR(-EINVAL); 2418 tfile = file->private_data; 2419 if (!tfile) 2420 return ERR_PTR(-EBADFD); 2421 return &tfile->socket; 2422 } 2423 EXPORT_SYMBOL_GPL(tun_get_socket); 2424 2425 module_init(tun_init); 2426 module_exit(tun_cleanup); 2427 MODULE_DESCRIPTION(DRV_DESCRIPTION); 2428 MODULE_AUTHOR(DRV_COPYRIGHT); 2429 MODULE_LICENSE("GPL"); 2430 MODULE_ALIAS_MISCDEV(TUN_MINOR); 2431 MODULE_ALIAS("devname:net/tun"); 2432