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