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