?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux...
[linux/fpc-iii.git] / drivers / net / tun.c
blob2c9e45f50edb299714f2c2fead0e78b4092b5904
1 /*
2 * TUN - Universal TUN/TAP device driver.
3 * Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $
16 */
17
18 /*
19 * Changes:
20 *
21 * Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
22 * Add TUNSETLINK ioctl to set the link encapsulation
23 *
24 * Mark Smith <markzzzsmith@yahoo.com.au>
25 * Use eth_random_addr() for tap MAC address.
26 *
27 * Harald Roelle <harald.roelle@ifi.lmu.de> 2004/04/20
28 * Fixes in packet dropping, queue length setting and queue wakeup.
29 * Increased default tx queue length.
30 * Added ethtool API.
31 * Minor cleanups
32 *
33 * Daniel Podlejski <underley@underley.eu.org>
34 * Modifications for 2.3.99-pre5 kernel.
35 */
36
37 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
38
39 #define DRV_NAME "tun"
40 #define DRV_VERSION "1.6"
41 #define DRV_DESCRIPTION "Universal TUN/TAP device driver"
42 #define DRV_COPYRIGHT "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>"
43
44 #include <linux/module.h>
45 #include <linux/errno.h>
46 #include <linux/kernel.h>
47 #include <linux/major.h>
48 #include <linux/slab.h>
49 #include <linux/poll.h>
50 #include <linux/fcntl.h>
51 #include <linux/init.h>
52 #include <linux/skbuff.h>
53 #include <linux/netdevice.h>
54 #include <linux/etherdevice.h>
55 #include <linux/miscdevice.h>
56 #include <linux/ethtool.h>
57 #include <linux/rtnetlink.h>
58 #include <linux/compat.h>
59 #include <linux/if.h>
60 #include <linux/if_arp.h>
61 #include <linux/if_ether.h>
62 #include <linux/if_tun.h>
63 #include <linux/if_vlan.h>
64 #include <linux/crc32.h>
65 #include <linux/nsproxy.h>
66 #include <linux/virtio_net.h>
67 #include <linux/rcupdate.h>
68 #include <net/net_namespace.h>
69 #include <net/netns/generic.h>
70 #include <net/rtnetlink.h>
71 #include <net/sock.h>
72 #include <linux/seq_file.h>
73 #include <linux/uio.h>
74
75 #include <asm/uaccess.h>
76
77 /* Uncomment to enable debugging */
78 /* #define TUN_DEBUG 1 */
79
80 #ifdef TUN_DEBUG
81 static int debug;
82
83 #define tun_debug(level, tun, fmt, args...) \
84 do { \
85 if (tun->debug) \
86 netdev_printk(level, tun->dev, fmt, ##args); \
87 } while (0)
88 #define DBG1(level, fmt, args...) \
89 do { \
90 if (debug == 2) \
91 printk(level fmt, ##args); \
92 } while (0)
93 #else
94 #define tun_debug(level, tun, fmt, args...) \
95 do { \
96 if (0) \
97 netdev_printk(level, tun->dev, fmt, ##args); \
98 } while (0)
99 #define DBG1(level, fmt, args...) \
100 do { \
101 if (0) \
102 printk(level fmt, ##args); \
103 } while (0)
104 #endif
105
106 /* TUN device flags */
107
108 /* IFF_ATTACH_QUEUE is never stored in device flags,
109 * overload it to mean fasync when stored there.
110 */
111 #define TUN_FASYNC IFF_ATTACH_QUEUE
112 /* High bits in flags field are unused. */
113 #define TUN_VNET_LE 0x80000000
114 #define TUN_VNET_BE 0x40000000
115
116 #define TUN_FEATURES (IFF_NO_PI | IFF_ONE_QUEUE | IFF_VNET_HDR | \
117 IFF_MULTI_QUEUE)
118 #define GOODCOPY_LEN 128
119
120 #define FLT_EXACT_COUNT 8
121 struct tap_filter {
122 unsigned int count; /* Number of addrs. Zero means disabled */
123 u32 mask[2]; /* Mask of the hashed addrs */
124 unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN];
125 };
126
127 /* MAX_TAP_QUEUES 256 is chosen to allow rx/tx queues to be equal
128 * to max number of VCPUs in guest. */
129 #define MAX_TAP_QUEUES 256
130 #define MAX_TAP_FLOWS 4096
131
132 #define TUN_FLOW_EXPIRE (3 * HZ)
133
134 /* A tun_file connects an open character device to a tuntap netdevice. It
135 * also contains all socket related structures (except sock_fprog and tap_filter)
136 * to serve as one transmit queue for tuntap device. The sock_fprog and
137 * tap_filter were kept in tun_struct since they were used for filtering for the
138 * netdevice not for a specific queue (at least I didn't see the requirement for
139 * this).
140 *
141 * RCU usage:
142 * The tun_file and tun_struct are loosely coupled, the pointer from one to the
143 * other can only be read while rcu_read_lock or rtnl_lock is held.
144 */
145 struct tun_file {
146 struct sock sk;
147 struct socket socket;
148 struct socket_wq wq;
149 struct tun_struct __rcu *tun;
150 struct fasync_struct *fasync;
151 /* only used for fasnyc */
152 unsigned int flags;
153 union {
154 u16 queue_index;
155 unsigned int ifindex;
156 };
157 struct list_head next;
158 struct tun_struct *detached;
159 };
160
161 struct tun_flow_entry {
162 struct hlist_node hash_link;
163 struct rcu_head rcu;
164 struct tun_struct *tun;
165
166 u32 rxhash;
167 u32 rps_rxhash;
168 int queue_index;
169 unsigned long updated;
170 };
171
172 #define TUN_NUM_FLOW_ENTRIES 1024
173
174 /* Since the socket were moved to tun_file, to preserve the behavior of persist
175 * device, socket filter, sndbuf and vnet header size were restore when the
176 * file were attached to a persist device.
177 */
178 struct tun_struct {
179 struct tun_file __rcu *tfiles[MAX_TAP_QUEUES];
180 unsigned int numqueues;
181 unsigned int flags;
182 kuid_t owner;
183 kgid_t group;
184
185 struct net_device *dev;
186 netdev_features_t set_features;
187 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
188 NETIF_F_TSO6|NETIF_F_UFO)
189
190 int align;
191 int vnet_hdr_sz;
192 int sndbuf;
193 struct tap_filter txflt;
194 struct sock_fprog fprog;
195 /* protected by rtnl lock */
196 bool filter_attached;
197 #ifdef TUN_DEBUG
198 int debug;
199 #endif
200 spinlock_t lock;
201 struct hlist_head flows[TUN_NUM_FLOW_ENTRIES];
202 struct timer_list flow_gc_timer;
203 unsigned long ageing_time;
204 unsigned int numdisabled;
205 struct list_head disabled;
206 void *security;
207 u32 flow_count;
208 };
209
210 #ifdef CONFIG_TUN_VNET_CROSS_LE
211 static inline bool tun_legacy_is_little_endian(struct tun_struct *tun)
212 {
213 return tun->flags & TUN_VNET_BE ? false :
214 virtio_legacy_is_little_endian();
215 }
216
217 static long tun_get_vnet_be(struct tun_struct *tun, int __user *argp)
218 {
219 int be = !!(tun->flags & TUN_VNET_BE);
220
221 if (put_user(be, argp))
222 return -EFAULT;
223
224 return 0;
225 }
226
227 static long tun_set_vnet_be(struct tun_struct *tun, int __user *argp)
228 {
229 int be;
230
231 if (get_user(be, argp))
232 return -EFAULT;
233
234 if (be)
235 tun->flags |= TUN_VNET_BE;
236 else
237 tun->flags &= ~TUN_VNET_BE;
238
239 return 0;
240 }
241 #else
242 static inline bool tun_legacy_is_little_endian(struct tun_struct *tun)
243 {
244 return virtio_legacy_is_little_endian();
245 }
246
247 static long tun_get_vnet_be(struct tun_struct *tun, int __user *argp)
248 {
249 return -EINVAL;
250 }
251
252 static long tun_set_vnet_be(struct tun_struct *tun, int __user *argp)
253 {
254 return -EINVAL;
255 }
256 #endif /* CONFIG_TUN_VNET_CROSS_LE */
257
258 static inline bool tun_is_little_endian(struct tun_struct *tun)
259 {
260 return tun->flags & TUN_VNET_LE ||
261 tun_legacy_is_little_endian(tun);
262 }
263
264 static inline u16 tun16_to_cpu(struct tun_struct *tun, __virtio16 val)
265 {
266 return __virtio16_to_cpu(tun_is_little_endian(tun), val);
267 }
268
269 static inline __virtio16 cpu_to_tun16(struct tun_struct *tun, u16 val)
270 {
271 return __cpu_to_virtio16(tun_is_little_endian(tun), val);
272 }
273
274 static inline u32 tun_hashfn(u32 rxhash)
275 {
276 return rxhash & 0x3ff;
277 }
278
279 static struct tun_flow_entry *tun_flow_find(struct hlist_head *head, u32 rxhash)
280 {
281 struct tun_flow_entry *e;
282
283 hlist_for_each_entry_rcu(e, head, hash_link) {
284 if (e->rxhash == rxhash)
285 return e;
286 }
287 return NULL;
288 }
289
290 static struct tun_flow_entry *tun_flow_create(struct tun_struct *tun,
291 struct hlist_head *head,
292 u32 rxhash, u16 queue_index)
293 {
294 struct tun_flow_entry *e = kmalloc(sizeof(*e), GFP_ATOMIC);
295
296 if (e) {
297 tun_debug(KERN_INFO, tun, "create flow: hash %u index %u\n",
298 rxhash, queue_index);
299 e->updated = jiffies;
300 e->rxhash = rxhash;
301 e->rps_rxhash = 0;
302 e->queue_index = queue_index;
303 e->tun = tun;
304 hlist_add_head_rcu(&e->hash_link, head);
305 ++tun->flow_count;
306 }
307 return e;
308 }
309
310 static void tun_flow_delete(struct tun_struct *tun, struct tun_flow_entry *e)
311 {
312 tun_debug(KERN_INFO, tun, "delete flow: hash %u index %u\n",
313 e->rxhash, e->queue_index);
314 hlist_del_rcu(&e->hash_link);
315 kfree_rcu(e, rcu);
316 --tun->flow_count;
317 }
318
319 static void tun_flow_flush(struct tun_struct *tun)
320 {
321 int i;
322
323 spin_lock_bh(&tun->lock);
324 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
325 struct tun_flow_entry *e;
326 struct hlist_node *n;
327
328 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link)
329 tun_flow_delete(tun, e);
330 }
331 spin_unlock_bh(&tun->lock);
332 }
333
334 static void tun_flow_delete_by_queue(struct tun_struct *tun, u16 queue_index)
335 {
336 int i;
337
338 spin_lock_bh(&tun->lock);
339 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
340 struct tun_flow_entry *e;
341 struct hlist_node *n;
342
343 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
344 if (e->queue_index == queue_index)
345 tun_flow_delete(tun, e);
346 }
347 }
348 spin_unlock_bh(&tun->lock);
349 }
350
351 static void tun_flow_cleanup(unsigned long data)
352 {
353 struct tun_struct *tun = (struct tun_struct *)data;
354 unsigned long delay = tun->ageing_time;
355 unsigned long next_timer = jiffies + delay;
356 unsigned long count = 0;
357 int i;
358
359 tun_debug(KERN_INFO, tun, "tun_flow_cleanup\n");
360
361 spin_lock_bh(&tun->lock);
362 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
363 struct tun_flow_entry *e;
364 struct hlist_node *n;
365
366 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
367 unsigned long this_timer;
368 count++;
369 this_timer = e->updated + delay;
370 if (time_before_eq(this_timer, jiffies))
371 tun_flow_delete(tun, e);
372 else if (time_before(this_timer, next_timer))
373 next_timer = this_timer;
374 }
375 }
376
377 if (count)
378 mod_timer(&tun->flow_gc_timer, round_jiffies_up(next_timer));
379 spin_unlock_bh(&tun->lock);
380 }
381
382 static void tun_flow_update(struct tun_struct *tun, u32 rxhash,
383 struct tun_file *tfile)
384 {
385 struct hlist_head *head;
386 struct tun_flow_entry *e;
387 unsigned long delay = tun->ageing_time;
388 u16 queue_index = tfile->queue_index;
389
390 if (!rxhash)
391 return;
392 else
393 head = &tun->flows[tun_hashfn(rxhash)];
394
395 rcu_read_lock();
396
397 /* We may get a very small possibility of OOO during switching, not
398 * worth to optimize.*/
399 if (tun->numqueues == 1 || tfile->detached)
400 goto unlock;
401
402 e = tun_flow_find(head, rxhash);
403 if (likely(e)) {
404 /* TODO: keep queueing to old queue until it's empty? */
405 e->queue_index = queue_index;
406 e->updated = jiffies;
407 sock_rps_record_flow_hash(e->rps_rxhash);
408 } else {
409 spin_lock_bh(&tun->lock);
410 if (!tun_flow_find(head, rxhash) &&
411 tun->flow_count < MAX_TAP_FLOWS)
412 tun_flow_create(tun, head, rxhash, queue_index);
413
414 if (!timer_pending(&tun->flow_gc_timer))
415 mod_timer(&tun->flow_gc_timer,
416 round_jiffies_up(jiffies + delay));
417 spin_unlock_bh(&tun->lock);
418 }
419
420 unlock:
421 rcu_read_unlock();
422 }
423
424 /**
425 * Save the hash received in the stack receive path and update the
426 * flow_hash table accordingly.
427 */
428 static inline void tun_flow_save_rps_rxhash(struct tun_flow_entry *e, u32 hash)
429 {
430 if (unlikely(e->rps_rxhash != hash))
431 e->rps_rxhash = hash;
432 }
433
434 /* We try to identify a flow through its rxhash first. The reason that
435 * we do not check rxq no. is because some cards(e.g 82599), chooses
436 * the rxq based on the txq where the last packet of the flow comes. As
437 * the userspace application move between processors, we may get a
438 * different rxq no. here. If we could not get rxhash, then we would
439 * hope the rxq no. may help here.
440 */
441 static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb,
442 void *accel_priv, select_queue_fallback_t fallback)
443 {
444 struct tun_struct *tun = netdev_priv(dev);
445 struct tun_flow_entry *e;
446 u32 txq = 0;
447 u32 numqueues = 0;
448
449 rcu_read_lock();
450 numqueues = ACCESS_ONCE(tun->numqueues);
451
452 txq = skb_get_hash(skb);
453 if (txq) {
454 e = tun_flow_find(&tun->flows[tun_hashfn(txq)], txq);
455 if (e) {
456 tun_flow_save_rps_rxhash(e, txq);
457 txq = e->queue_index;
458 } else
459 /* use multiply and shift instead of expensive divide */
460 txq = ((u64)txq * numqueues) >> 32;
461 } else if (likely(skb_rx_queue_recorded(skb))) {
462 txq = skb_get_rx_queue(skb);
463 while (unlikely(txq >= numqueues))
464 txq -= numqueues;
465 }
466
467 rcu_read_unlock();
468 return txq;
469 }
470
471 static inline bool tun_not_capable(struct tun_struct *tun)
472 {
473 const struct cred *cred = current_cred();
474 struct net *net = dev_net(tun->dev);
475
476 return ((uid_valid(tun->owner) && !uid_eq(cred->euid, tun->owner)) ||
477 (gid_valid(tun->group) && !in_egroup_p(tun->group))) &&
478 !ns_capable(net->user_ns, CAP_NET_ADMIN);
479 }
480
481 static void tun_set_real_num_queues(struct tun_struct *tun)
482 {
483 netif_set_real_num_tx_queues(tun->dev, tun->numqueues);
484 netif_set_real_num_rx_queues(tun->dev, tun->numqueues);
485 }
486
487 static void tun_disable_queue(struct tun_struct *tun, struct tun_file *tfile)
488 {
489 tfile->detached = tun;
490 list_add_tail(&tfile->next, &tun->disabled);
491 ++tun->numdisabled;
492 }
493
494 static struct tun_struct *tun_enable_queue(struct tun_file *tfile)
495 {
496 struct tun_struct *tun = tfile->detached;
497
498 tfile->detached = NULL;
499 list_del_init(&tfile->next);
500 --tun->numdisabled;
501 return tun;
502 }
503
504 static void tun_queue_purge(struct tun_file *tfile)
505 {
506 skb_queue_purge(&tfile->sk.sk_receive_queue);
507 skb_queue_purge(&tfile->sk.sk_error_queue);
508 }
509
510 static void __tun_detach(struct tun_file *tfile, bool clean)
511 {
512 struct tun_file *ntfile;
513 struct tun_struct *tun;
514
515 tun = rtnl_dereference(tfile->tun);
516
517 if (tun && !tfile->detached) {
518 u16 index = tfile->queue_index;
519 BUG_ON(index >= tun->numqueues);
520
521 rcu_assign_pointer(tun->tfiles[index],
522 tun->tfiles[tun->numqueues - 1]);
523 ntfile = rtnl_dereference(tun->tfiles[index]);
524 ntfile->queue_index = index;
525
526 --tun->numqueues;
527 if (clean) {
528 RCU_INIT_POINTER(tfile->tun, NULL);
529 sock_put(&tfile->sk);
530 } else
531 tun_disable_queue(tun, tfile);
532
533 synchronize_net();
534 tun_flow_delete_by_queue(tun, tun->numqueues + 1);
535 /* Drop read queue */
536 tun_queue_purge(tfile);
537 tun_set_real_num_queues(tun);
538 } else if (tfile->detached && clean) {
539 tun = tun_enable_queue(tfile);
540 sock_put(&tfile->sk);
541 }
542
543 if (clean) {
544 if (tun && tun->numqueues == 0 && tun->numdisabled == 0) {
545 netif_carrier_off(tun->dev);
546
547 if (!(tun->flags & IFF_PERSIST) &&
548 tun->dev->reg_state == NETREG_REGISTERED)
549 unregister_netdevice(tun->dev);
550 }
551 sock_put(&tfile->sk);
552 }
553 }
554
555 static void tun_detach(struct tun_file *tfile, bool clean)
556 {
557 rtnl_lock();
558 __tun_detach(tfile, clean);
559 rtnl_unlock();
560 }
561
562 static void tun_detach_all(struct net_device *dev)
563 {
564 struct tun_struct *tun = netdev_priv(dev);
565 struct tun_file *tfile, *tmp;
566 int i, n = tun->numqueues;
567
568 for (i = 0; i < n; i++) {
569 tfile = rtnl_dereference(tun->tfiles[i]);
570 BUG_ON(!tfile);
571 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
572 RCU_INIT_POINTER(tfile->tun, NULL);
573 --tun->numqueues;
574 }
575 list_for_each_entry(tfile, &tun->disabled, next) {
576 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
577 RCU_INIT_POINTER(tfile->tun, NULL);
578 }
579 BUG_ON(tun->numqueues != 0);
580
581 synchronize_net();
582 for (i = 0; i < n; i++) {
583 tfile = rtnl_dereference(tun->tfiles[i]);
584 /* Drop read queue */
585 tun_queue_purge(tfile);
586 sock_put(&tfile->sk);
587 }
588 list_for_each_entry_safe(tfile, tmp, &tun->disabled, next) {
589 tun_enable_queue(tfile);
590 tun_queue_purge(tfile);
591 sock_put(&tfile->sk);
592 }
593 BUG_ON(tun->numdisabled != 0);
594
595 if (tun->flags & IFF_PERSIST)
596 module_put(THIS_MODULE);
597 }
598
599 static int tun_attach(struct tun_struct *tun, struct file *file, bool skip_filter)
600 {
601 struct tun_file *tfile = file->private_data;
602 int err;
603
604 err = security_tun_dev_attach(tfile->socket.sk, tun->security);
605 if (err < 0)
606 goto out;
607
608 err = -EINVAL;
609 if (rtnl_dereference(tfile->tun) && !tfile->detached)
610 goto out;
611
612 err = -EBUSY;
613 if (!(tun->flags & IFF_MULTI_QUEUE) && tun->numqueues == 1)
614 goto out;
615
616 err = -E2BIG;
617 if (!tfile->detached &&
618 tun->numqueues + tun->numdisabled == MAX_TAP_QUEUES)
619 goto out;
620
621 err = 0;
622
623 /* Re-attach the filter to persist device */
624 if (!skip_filter && (tun->filter_attached == true)) {
625 err = __sk_attach_filter(&tun->fprog, tfile->socket.sk,
626 lockdep_rtnl_is_held());
627 if (!err)
628 goto out;
629 }
630 tfile->queue_index = tun->numqueues;
631 rcu_assign_pointer(tfile->tun, tun);
632 rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile);
633 tun->numqueues++;
634
635 if (tfile->detached)
636 tun_enable_queue(tfile);
637 else
638 sock_hold(&tfile->sk);
639
640 tun_set_real_num_queues(tun);
641
642 /* device is allowed to go away first, so no need to hold extra
643 * refcnt.
644 */
645
646 out:
647 return err;
648 }
649
650 static struct tun_struct *__tun_get(struct tun_file *tfile)
651 {
652 struct tun_struct *tun;
653
654 rcu_read_lock();
655 tun = rcu_dereference(tfile->tun);
656 if (tun)
657 dev_hold(tun->dev);
658 rcu_read_unlock();
659
660 return tun;
661 }
662
663 static struct tun_struct *tun_get(struct file *file)
664 {
665 return __tun_get(file->private_data);
666 }
667
668 static void tun_put(struct tun_struct *tun)
669 {
670 dev_put(tun->dev);
671 }
672
673 /* TAP filtering */
674 static void addr_hash_set(u32 *mask, const u8 *addr)
675 {
676 int n = ether_crc(ETH_ALEN, addr) >> 26;
677 mask[n >> 5] |= (1 << (n & 31));
678 }
679
680 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
681 {
682 int n = ether_crc(ETH_ALEN, addr) >> 26;
683 return mask[n >> 5] & (1 << (n & 31));
684 }
685
686 static int update_filter(struct tap_filter *filter, void __user *arg)
687 {
688 struct { u8 u[ETH_ALEN]; } *addr;
689 struct tun_filter uf;
690 int err, alen, n, nexact;
691
692 if (copy_from_user(&uf, arg, sizeof(uf)))
693 return -EFAULT;
694
695 if (!uf.count) {
696 /* Disabled */
697 filter->count = 0;
698 return 0;
699 }
700
701 alen = ETH_ALEN * uf.count;
702 addr = kmalloc(alen, GFP_KERNEL);
703 if (!addr)
704 return -ENOMEM;
705
706 if (copy_from_user(addr, arg + sizeof(uf), alen)) {
707 err = -EFAULT;
708 goto done;
709 }
710
711 /* The filter is updated without holding any locks. Which is
712 * perfectly safe. We disable it first and in the worst
713 * case we'll accept a few undesired packets. */
714 filter->count = 0;
715 wmb();
716
717 /* Use first set of addresses as an exact filter */
718 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
719 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
720
721 nexact = n;
722
723 /* Remaining multicast addresses are hashed,
724 * unicast will leave the filter disabled. */
725 memset(filter->mask, 0, sizeof(filter->mask));
726 for (; n < uf.count; n++) {
727 if (!is_multicast_ether_addr(addr[n].u)) {
728 err = 0; /* no filter */
729 goto done;
730 }
731 addr_hash_set(filter->mask, addr[n].u);
732 }
733
734 /* For ALLMULTI just set the mask to all ones.
735 * This overrides the mask populated above. */
736 if ((uf.flags & TUN_FLT_ALLMULTI))
737 memset(filter->mask, ~0, sizeof(filter->mask));
738
739 /* Now enable the filter */
740 wmb();
741 filter->count = nexact;
742
743 /* Return the number of exact filters */
744 err = nexact;
745
746 done:
747 kfree(addr);
748 return err;
749 }
750
751 /* Returns: 0 - drop, !=0 - accept */
752 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
753 {
754 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
755 * at this point. */
756 struct ethhdr *eh = (struct ethhdr *) skb->data;
757 int i;
758
759 /* Exact match */
760 for (i = 0; i < filter->count; i++)
761 if (ether_addr_equal(eh->h_dest, filter->addr[i]))
762 return 1;
763
764 /* Inexact match (multicast only) */
765 if (is_multicast_ether_addr(eh->h_dest))
766 return addr_hash_test(filter->mask, eh->h_dest);
767
768 return 0;
769 }
770
771 /*
772 * Checks whether the packet is accepted or not.
773 * Returns: 0 - drop, !=0 - accept
774 */
775 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
776 {
777 if (!filter->count)
778 return 1;
779
780 return run_filter(filter, skb);
781 }
782
783 /* Network device part of the driver */
784
785 static const struct ethtool_ops tun_ethtool_ops;
786
787 /* Net device detach from fd. */
788 static void tun_net_uninit(struct net_device *dev)
789 {
790 tun_detach_all(dev);
791 }
792
793 /* Net device open. */
794 static int tun_net_open(struct net_device *dev)
795 {
796 netif_tx_start_all_queues(dev);
797 return 0;
798 }
799
800 /* Net device close. */
801 static int tun_net_close(struct net_device *dev)
802 {
803 netif_tx_stop_all_queues(dev);
804 return 0;
805 }
806
807 /* Net device start xmit */
808 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
809 {
810 struct tun_struct *tun = netdev_priv(dev);
811 int txq = skb->queue_mapping;
812 struct tun_file *tfile;
813 u32 numqueues = 0;
814
815 rcu_read_lock();
816 tfile = rcu_dereference(tun->tfiles[txq]);
817 numqueues = ACCESS_ONCE(tun->numqueues);
818
819 /* Drop packet if interface is not attached */
820 if (txq >= numqueues)
821 goto drop;
822
823 if (numqueues == 1) {
824 /* Select queue was not called for the skbuff, so we extract the
825 * RPS hash and save it into the flow_table here.
826 */
827 __u32 rxhash;
828
829 rxhash = skb_get_hash(skb);
830 if (rxhash) {
831 struct tun_flow_entry *e;
832 e = tun_flow_find(&tun->flows[tun_hashfn(rxhash)],
833 rxhash);
834 if (e)
835 tun_flow_save_rps_rxhash(e, rxhash);
836 }
837 }
838
839 tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len);
840
841 BUG_ON(!tfile);
842
843 /* Drop if the filter does not like it.
844 * This is a noop if the filter is disabled.
845 * Filter can be enabled only for the TAP devices. */
846 if (!check_filter(&tun->txflt, skb))
847 goto drop;
848
849 if (tfile->socket.sk->sk_filter &&
850 sk_filter(tfile->socket.sk, skb))
851 goto drop;
852
853 /* Limit the number of packets queued by dividing txq length with the
854 * number of queues.
855 */
856 if (skb_queue_len(&tfile->socket.sk->sk_receive_queue) * numqueues
857 >= dev->tx_queue_len)
858 goto drop;
859
860 if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
861 goto drop;
862
863 if (skb->sk && sk_fullsock(skb->sk)) {
864 sock_tx_timestamp(skb->sk, &skb_shinfo(skb)->tx_flags);
865 sw_tx_timestamp(skb);
866 }
867
868 /* Orphan the skb - required as we might hang on to it
869 * for indefinite time.
870 */
871 skb_orphan(skb);
872
873 nf_reset(skb);
874
875 /* Enqueue packet */
876 skb_queue_tail(&tfile->socket.sk->sk_receive_queue, skb);
877
878 /* Notify and wake up reader process */
879 if (tfile->flags & TUN_FASYNC)
880 kill_fasync(&tfile->fasync, SIGIO, POLL_IN);
881 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
882
883 rcu_read_unlock();
884 return NETDEV_TX_OK;
885
886 drop:
887 dev->stats.tx_dropped++;
888 skb_tx_error(skb);
889 kfree_skb(skb);
890 rcu_read_unlock();
891 return NET_XMIT_DROP;
892 }
893
894 static void tun_net_mclist(struct net_device *dev)
895 {
896 /*
897 * This callback is supposed to deal with mc filter in
898 * _rx_ path and has nothing to do with the _tx_ path.
899 * In rx path we always accept everything userspace gives us.
900 */
901 }
902
903 #define MIN_MTU 68
904 #define MAX_MTU 65535
905
906 static int
907 tun_net_change_mtu(struct net_device *dev, int new_mtu)
908 {
909 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
910 return -EINVAL;
911 dev->mtu = new_mtu;
912 return 0;
913 }
914
915 static netdev_features_t tun_net_fix_features(struct net_device *dev,
916 netdev_features_t features)
917 {
918 struct tun_struct *tun = netdev_priv(dev);
919
920 return (features & tun->set_features) | (features & ~TUN_USER_FEATURES);
921 }
922 #ifdef CONFIG_NET_POLL_CONTROLLER
923 static void tun_poll_controller(struct net_device *dev)
924 {
925 /*
926 * Tun only receives frames when:
927 * 1) the char device endpoint gets data from user space
928 * 2) the tun socket gets a sendmsg call from user space
929 * Since both of those are synchronous operations, we are guaranteed
930 * never to have pending data when we poll for it
931 * so there is nothing to do here but return.
932 * We need this though so netpoll recognizes us as an interface that
933 * supports polling, which enables bridge devices in virt setups to
934 * still use netconsole
935 */
936 return;
937 }
938 #endif
939
940 static void tun_set_headroom(struct net_device *dev, int new_hr)
941 {
942 struct tun_struct *tun = netdev_priv(dev);
943
944 if (new_hr < NET_SKB_PAD)
945 new_hr = NET_SKB_PAD;
946
947 tun->align = new_hr;
948 }
949
950 static const struct net_device_ops tun_netdev_ops = {
951 .ndo_uninit = tun_net_uninit,
952 .ndo_open = tun_net_open,
953 .ndo_stop = tun_net_close,
954 .ndo_start_xmit = tun_net_xmit,
955 .ndo_change_mtu = tun_net_change_mtu,
956 .ndo_fix_features = tun_net_fix_features,
957 .ndo_select_queue = tun_select_queue,
958 #ifdef CONFIG_NET_POLL_CONTROLLER
959 .ndo_poll_controller = tun_poll_controller,
960 #endif
961 .ndo_set_rx_headroom = tun_set_headroom,
962 };
963
964 static const struct net_device_ops tap_netdev_ops = {
965 .ndo_uninit = tun_net_uninit,
966 .ndo_open = tun_net_open,
967 .ndo_stop = tun_net_close,
968 .ndo_start_xmit = tun_net_xmit,
969 .ndo_change_mtu = tun_net_change_mtu,
970 .ndo_fix_features = tun_net_fix_features,
971 .ndo_set_rx_mode = tun_net_mclist,
972 .ndo_set_mac_address = eth_mac_addr,
973 .ndo_validate_addr = eth_validate_addr,
974 .ndo_select_queue = tun_select_queue,
975 #ifdef CONFIG_NET_POLL_CONTROLLER
976 .ndo_poll_controller = tun_poll_controller,
977 #endif
978 .ndo_features_check = passthru_features_check,
979 .ndo_set_rx_headroom = tun_set_headroom,
980 };
981
982 static void tun_flow_init(struct tun_struct *tun)
983 {
984 int i;
985
986 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++)
987 INIT_HLIST_HEAD(&tun->flows[i]);
988
989 tun->ageing_time = TUN_FLOW_EXPIRE;
990 setup_timer(&tun->flow_gc_timer, tun_flow_cleanup, (unsigned long)tun);
991 mod_timer(&tun->flow_gc_timer,
992 round_jiffies_up(jiffies + tun->ageing_time));
993 }
994
995 static void tun_flow_uninit(struct tun_struct *tun)
996 {
997 del_timer_sync(&tun->flow_gc_timer);
998 tun_flow_flush(tun);
999 }
1000
1001 /* Initialize net device. */
1002 static void tun_net_init(struct net_device *dev)
1003 {
1004 struct tun_struct *tun = netdev_priv(dev);
1005
1006 switch (tun->flags & TUN_TYPE_MASK) {
1007 case IFF_TUN:
1008 dev->netdev_ops = &tun_netdev_ops;
1009
1010 /* Point-to-Point TUN Device */
1011 dev->hard_header_len = 0;
1012 dev->addr_len = 0;
1013 dev->mtu = 1500;
1014
1015 /* Zero header length */
1016 dev->type = ARPHRD_NONE;
1017 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1018 break;
1019
1020 case IFF_TAP:
1021 dev->netdev_ops = &tap_netdev_ops;
1022 /* Ethernet TAP Device */
1023 ether_setup(dev);
1024 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1025 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1026
1027 eth_hw_addr_random(dev);
1028
1029 break;
1030 }
1031 }
1032
1033 /* Character device part */
1034
1035 /* Poll */
1036 static unsigned int tun_chr_poll(struct file *file, poll_table *wait)
1037 {
1038 struct tun_file *tfile = file->private_data;
1039 struct tun_struct *tun = __tun_get(tfile);
1040 struct sock *sk;
1041 unsigned int mask = 0;
1042
1043 if (!tun)
1044 return POLLERR;
1045
1046 sk = tfile->socket.sk;
1047
1048 tun_debug(KERN_INFO, tun, "tun_chr_poll\n");
1049
1050 poll_wait(file, sk_sleep(sk), wait);
1051
1052 if (!skb_queue_empty(&sk->sk_receive_queue))
1053 mask |= POLLIN | POLLRDNORM;
1054
1055 if (sock_writeable(sk) ||
1056 (!test_and_set_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
1057 sock_writeable(sk)))
1058 mask |= POLLOUT | POLLWRNORM;
1059
1060 if (tun->dev->reg_state != NETREG_REGISTERED)
1061 mask = POLLERR;
1062
1063 tun_put(tun);
1064 return mask;
1065 }
1066
1067 /* prepad is the amount to reserve at front. len is length after that.
1068 * linear is a hint as to how much to copy (usually headers). */
1069 static struct sk_buff *tun_alloc_skb(struct tun_file *tfile,
1070 size_t prepad, size_t len,
1071 size_t linear, int noblock)
1072 {
1073 struct sock *sk = tfile->socket.sk;
1074 struct sk_buff *skb;
1075 int err;
1076
1077 /* Under a page? Don't bother with paged skb. */
1078 if (prepad + len < PAGE_SIZE || !linear)
1079 linear = len;
1080
1081 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
1082 &err, 0);
1083 if (!skb)
1084 return ERR_PTR(err);
1085
1086 skb_reserve(skb, prepad);
1087 skb_put(skb, linear);
1088 skb->data_len = len - linear;
1089 skb->len += len - linear;
1090
1091 return skb;
1092 }
1093
1094 /* Get packet from user space buffer */
1095 static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
1096 void *msg_control, struct iov_iter *from,
1097 int noblock)
1098 {
1099 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
1100 struct sk_buff *skb;
1101 size_t total_len = iov_iter_count(from);
1102 size_t len = total_len, align = tun->align, linear;
1103 struct virtio_net_hdr gso = { 0 };
1104 int good_linear;
1105 int copylen;
1106 bool zerocopy = false;
1107 int err;
1108 u32 rxhash;
1109 ssize_t n;
1110
1111 if (!(tun->dev->flags & IFF_UP))
1112 return -EIO;
1113
1114 if (!(tun->flags & IFF_NO_PI)) {
1115 if (len < sizeof(pi))
1116 return -EINVAL;
1117 len -= sizeof(pi);
1118
1119 n = copy_from_iter(&pi, sizeof(pi), from);
1120 if (n != sizeof(pi))
1121 return -EFAULT;
1122 }
1123
1124 if (tun->flags & IFF_VNET_HDR) {
1125 if (len < tun->vnet_hdr_sz)
1126 return -EINVAL;
1127 len -= tun->vnet_hdr_sz;
1128
1129 n = copy_from_iter(&gso, sizeof(gso), from);
1130 if (n != sizeof(gso))
1131 return -EFAULT;
1132
1133 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
1134 tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2 > tun16_to_cpu(tun, gso.hdr_len))
1135 gso.hdr_len = cpu_to_tun16(tun, tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2);
1136
1137 if (tun16_to_cpu(tun, gso.hdr_len) > len)
1138 return -EINVAL;
1139 iov_iter_advance(from, tun->vnet_hdr_sz - sizeof(gso));
1140 }
1141
1142 if ((tun->flags & TUN_TYPE_MASK) == IFF_TAP) {
1143 align += NET_IP_ALIGN;
1144 if (unlikely(len < ETH_HLEN ||
1145 (gso.hdr_len && tun16_to_cpu(tun, gso.hdr_len) < ETH_HLEN)))
1146 return -EINVAL;
1147 }
1148
1149 good_linear = SKB_MAX_HEAD(align);
1150
1151 if (msg_control) {
1152 struct iov_iter i = *from;
1153
1154 /* There are 256 bytes to be copied in skb, so there is
1155 * enough room for skb expand head in case it is used.
1156 * The rest of the buffer is mapped from userspace.
1157 */
1158 copylen = gso.hdr_len ? tun16_to_cpu(tun, gso.hdr_len) : GOODCOPY_LEN;
1159 if (copylen > good_linear)
1160 copylen = good_linear;
1161 linear = copylen;
1162 iov_iter_advance(&i, copylen);
1163 if (iov_iter_npages(&i, INT_MAX) <= MAX_SKB_FRAGS)
1164 zerocopy = true;
1165 }
1166
1167 if (!zerocopy) {
1168 copylen = len;
1169 if (tun16_to_cpu(tun, gso.hdr_len) > good_linear)
1170 linear = good_linear;
1171 else
1172 linear = tun16_to_cpu(tun, gso.hdr_len);
1173 }
1174
1175 skb = tun_alloc_skb(tfile, align, copylen, linear, noblock);
1176 if (IS_ERR(skb)) {
1177 if (PTR_ERR(skb) != -EAGAIN)
1178 tun->dev->stats.rx_dropped++;
1179 return PTR_ERR(skb);
1180 }
1181
1182 if (zerocopy)
1183 err = zerocopy_sg_from_iter(skb, from);
1184 else {
1185 err = skb_copy_datagram_from_iter(skb, 0, from, len);
1186 if (!err && msg_control) {
1187 struct ubuf_info *uarg = msg_control;
1188 uarg->callback(uarg, false);
1189 }
1190 }
1191
1192 if (err) {
1193 tun->dev->stats.rx_dropped++;
1194 kfree_skb(skb);
1195 return -EFAULT;
1196 }
1197
1198 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
1199 if (!skb_partial_csum_set(skb, tun16_to_cpu(tun, gso.csum_start),
1200 tun16_to_cpu(tun, gso.csum_offset))) {
1201 tun->dev->stats.rx_frame_errors++;
1202 kfree_skb(skb);
1203 return -EINVAL;
1204 }
1205 }
1206
1207 switch (tun->flags & TUN_TYPE_MASK) {
1208 case IFF_TUN:
1209 if (tun->flags & IFF_NO_PI) {
1210 switch (skb->data[0] & 0xf0) {
1211 case 0x40:
1212 pi.proto = htons(ETH_P_IP);
1213 break;
1214 case 0x60:
1215 pi.proto = htons(ETH_P_IPV6);
1216 break;
1217 default:
1218 tun->dev->stats.rx_dropped++;
1219 kfree_skb(skb);
1220 return -EINVAL;
1221 }
1222 }
1223
1224 skb_reset_mac_header(skb);
1225 skb->protocol = pi.proto;
1226 skb->dev = tun->dev;
1227 break;
1228 case IFF_TAP:
1229 skb->protocol = eth_type_trans(skb, tun->dev);
1230 break;
1231 }
1232
1233 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
1234 pr_debug("GSO!\n");
1235 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
1236 case VIRTIO_NET_HDR_GSO_TCPV4:
1237 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
1238 break;
1239 case VIRTIO_NET_HDR_GSO_TCPV6:
1240 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
1241 break;
1242 case VIRTIO_NET_HDR_GSO_UDP:
1243 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
1244 break;
1245 default:
1246 tun->dev->stats.rx_frame_errors++;
1247 kfree_skb(skb);
1248 return -EINVAL;
1249 }
1250
1251 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
1252 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
1253
1254 skb_shinfo(skb)->gso_size = tun16_to_cpu(tun, gso.gso_size);
1255 if (skb_shinfo(skb)->gso_size == 0) {
1256 tun->dev->stats.rx_frame_errors++;
1257 kfree_skb(skb);
1258 return -EINVAL;
1259 }
1260
1261 /* Header must be checked, and gso_segs computed. */
1262 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
1263 skb_shinfo(skb)->gso_segs = 0;
1264 }
1265
1266 /* copy skb_ubuf_info for callback when skb has no error */
1267 if (zerocopy) {
1268 skb_shinfo(skb)->destructor_arg = msg_control;
1269 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1270 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
1271 }
1272
1273 skb_reset_network_header(skb);
1274 skb_probe_transport_header(skb, 0);
1275
1276 rxhash = skb_get_hash(skb);
1277 netif_rx_ni(skb);
1278
1279 tun->dev->stats.rx_packets++;
1280 tun->dev->stats.rx_bytes += len;
1281
1282 tun_flow_update(tun, rxhash, tfile);
1283 return total_len;
1284 }
1285
1286 static ssize_t tun_chr_write_iter(struct kiocb *iocb, struct iov_iter *from)
1287 {
1288 struct file *file = iocb->ki_filp;
1289 struct tun_struct *tun = tun_get(file);
1290 struct tun_file *tfile = file->private_data;
1291 ssize_t result;
1292
1293 if (!tun)
1294 return -EBADFD;
1295
1296 result = tun_get_user(tun, tfile, NULL, from, file->f_flags & O_NONBLOCK);
1297
1298 tun_put(tun);
1299 return result;
1300 }
1301
1302 /* Put packet to the user space buffer */
1303 static ssize_t tun_put_user(struct tun_struct *tun,
1304 struct tun_file *tfile,
1305 struct sk_buff *skb,
1306 struct iov_iter *iter)
1307 {
1308 struct tun_pi pi = { 0, skb->protocol };
1309 ssize_t total;
1310 int vlan_offset = 0;
1311 int vlan_hlen = 0;
1312 int vnet_hdr_sz = 0;
1313
1314 if (skb_vlan_tag_present(skb))
1315 vlan_hlen = VLAN_HLEN;
1316
1317 if (tun->flags & IFF_VNET_HDR)
1318 vnet_hdr_sz = tun->vnet_hdr_sz;
1319
1320 total = skb->len + vlan_hlen + vnet_hdr_sz;
1321
1322 if (!(tun->flags & IFF_NO_PI)) {
1323 if (iov_iter_count(iter) < sizeof(pi))
1324 return -EINVAL;
1325
1326 total += sizeof(pi);
1327 if (iov_iter_count(iter) < total) {
1328 /* Packet will be striped */
1329 pi.flags |= TUN_PKT_STRIP;
1330 }
1331
1332 if (copy_to_iter(&pi, sizeof(pi), iter) != sizeof(pi))
1333 return -EFAULT;
1334 }
1335
1336 if (vnet_hdr_sz) {
1337 struct virtio_net_hdr gso = { 0 }; /* no info leak */
1338 if (iov_iter_count(iter) < vnet_hdr_sz)
1339 return -EINVAL;
1340
1341 if (skb_is_gso(skb)) {
1342 struct skb_shared_info *sinfo = skb_shinfo(skb);
1343
1344 /* This is a hint as to how much should be linear. */
1345 gso.hdr_len = cpu_to_tun16(tun, skb_headlen(skb));
1346 gso.gso_size = cpu_to_tun16(tun, sinfo->gso_size);
1347 if (sinfo->gso_type & SKB_GSO_TCPV4)
1348 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
1349 else if (sinfo->gso_type & SKB_GSO_TCPV6)
1350 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
1351 else if (sinfo->gso_type & SKB_GSO_UDP)
1352 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
1353 else {
1354 pr_err("unexpected GSO type: "
1355 "0x%x, gso_size %d, hdr_len %d\n",
1356 sinfo->gso_type, tun16_to_cpu(tun, gso.gso_size),
1357 tun16_to_cpu(tun, gso.hdr_len));
1358 print_hex_dump(KERN_ERR, "tun: ",
1359 DUMP_PREFIX_NONE,
1360 16, 1, skb->head,
1361 min((int)tun16_to_cpu(tun, gso.hdr_len), 64), true);
1362 WARN_ON_ONCE(1);
1363 return -EINVAL;
1364 }
1365 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
1366 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
1367 } else
1368 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
1369
1370 if (skb->ip_summed == CHECKSUM_PARTIAL) {
1371 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
1372 gso.csum_start = cpu_to_tun16(tun, skb_checksum_start_offset(skb) +
1373 vlan_hlen);
1374 gso.csum_offset = cpu_to_tun16(tun, skb->csum_offset);
1375 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
1376 gso.flags = VIRTIO_NET_HDR_F_DATA_VALID;
1377 } /* else everything is zero */
1378
1379 if (copy_to_iter(&gso, sizeof(gso), iter) != sizeof(gso))
1380 return -EFAULT;
1381
1382 iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso));
1383 }
1384
1385 if (vlan_hlen) {
1386 int ret;
1387 struct {
1388 __be16 h_vlan_proto;
1389 __be16 h_vlan_TCI;
1390 } veth;
1391
1392 veth.h_vlan_proto = skb->vlan_proto;
1393 veth.h_vlan_TCI = htons(skb_vlan_tag_get(skb));
1394
1395 vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);
1396
1397 ret = skb_copy_datagram_iter(skb, 0, iter, vlan_offset);
1398 if (ret || !iov_iter_count(iter))
1399 goto done;
1400
1401 ret = copy_to_iter(&veth, sizeof(veth), iter);
1402 if (ret != sizeof(veth) || !iov_iter_count(iter))
1403 goto done;
1404 }
1405
1406 skb_copy_datagram_iter(skb, vlan_offset, iter, skb->len - vlan_offset);
1407
1408 done:
1409 tun->dev->stats.tx_packets++;
1410 tun->dev->stats.tx_bytes += skb->len + vlan_hlen;
1411
1412 return total;
1413 }
1414
1415 static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
1416 struct iov_iter *to,
1417 int noblock)
1418 {
1419 struct sk_buff *skb;
1420 ssize_t ret;
1421 int peeked, err, off = 0;
1422
1423 tun_debug(KERN_INFO, tun, "tun_do_read\n");
1424
1425 if (!iov_iter_count(to))
1426 return 0;
1427
1428 if (tun->dev->reg_state != NETREG_REGISTERED)
1429 return -EIO;
1430
1431 /* Read frames from queue */
1432 skb = __skb_recv_datagram(tfile->socket.sk, noblock ? MSG_DONTWAIT : 0,
1433 &peeked, &off, &err);
1434 if (!skb)
1435 return err;
1436
1437 ret = tun_put_user(tun, tfile, skb, to);
1438 if (unlikely(ret < 0))
1439 kfree_skb(skb);
1440 else
1441 consume_skb(skb);
1442
1443 return ret;
1444 }
1445
1446 static ssize_t tun_chr_read_iter(struct kiocb *iocb, struct iov_iter *to)
1447 {
1448 struct file *file = iocb->ki_filp;
1449 struct tun_file *tfile = file->private_data;
1450 struct tun_struct *tun = __tun_get(tfile);
1451 ssize_t len = iov_iter_count(to), ret;
1452
1453 if (!tun)
1454 return -EBADFD;
1455 ret = tun_do_read(tun, tfile, to, file->f_flags & O_NONBLOCK);
1456 ret = min_t(ssize_t, ret, len);
1457 if (ret > 0)
1458 iocb->ki_pos = ret;
1459 tun_put(tun);
1460 return ret;
1461 }
1462
1463 static void tun_free_netdev(struct net_device *dev)
1464 {
1465 struct tun_struct *tun = netdev_priv(dev);
1466
1467 BUG_ON(!(list_empty(&tun->disabled)));
1468 tun_flow_uninit(tun);
1469 security_tun_dev_free_security(tun->security);
1470 free_netdev(dev);
1471 }
1472
1473 static void tun_setup(struct net_device *dev)
1474 {
1475 struct tun_struct *tun = netdev_priv(dev);
1476
1477 tun->owner = INVALID_UID;
1478 tun->group = INVALID_GID;
1479
1480 dev->ethtool_ops = &tun_ethtool_ops;
1481 dev->destructor = tun_free_netdev;
1482 /* We prefer our own queue length */
1483 dev->tx_queue_len = TUN_READQ_SIZE;
1484 }
1485
1486 /* Trivial set of netlink ops to allow deleting tun or tap
1487 * device with netlink.
1488 */
1489 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
1490 {
1491 return -EINVAL;
1492 }
1493
1494 static struct rtnl_link_ops tun_link_ops __read_mostly = {
1495 .kind = DRV_NAME,
1496 .priv_size = sizeof(struct tun_struct),
1497 .setup = tun_setup,
1498 .validate = tun_validate,
1499 };
1500
1501 static void tun_sock_write_space(struct sock *sk)
1502 {
1503 struct tun_file *tfile;
1504 wait_queue_head_t *wqueue;
1505
1506 if (!sock_writeable(sk))
1507 return;
1508
1509 if (!test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags))
1510 return;
1511
1512 wqueue = sk_sleep(sk);
1513 if (wqueue && waitqueue_active(wqueue))
1514 wake_up_interruptible_sync_poll(wqueue, POLLOUT |
1515 POLLWRNORM | POLLWRBAND);
1516
1517 tfile = container_of(sk, struct tun_file, sk);
1518 kill_fasync(&tfile->fasync, SIGIO, POLL_OUT);
1519 }
1520
1521 static int tun_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
1522 {
1523 int ret;
1524 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1525 struct tun_struct *tun = __tun_get(tfile);
1526
1527 if (!tun)
1528 return -EBADFD;
1529
1530 ret = tun_get_user(tun, tfile, m->msg_control, &m->msg_iter,
1531 m->msg_flags & MSG_DONTWAIT);
1532 tun_put(tun);
1533 return ret;
1534 }
1535
1536 static int tun_recvmsg(struct socket *sock, struct msghdr *m, size_t total_len,
1537 int flags)
1538 {
1539 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1540 struct tun_struct *tun = __tun_get(tfile);
1541 int ret;
1542
1543 if (!tun)
1544 return -EBADFD;
1545
1546 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC|MSG_ERRQUEUE)) {
1547 ret = -EINVAL;
1548 goto out;
1549 }
1550 if (flags & MSG_ERRQUEUE) {
1551 ret = sock_recv_errqueue(sock->sk, m, total_len,
1552 SOL_PACKET, TUN_TX_TIMESTAMP);
1553 goto out;
1554 }
1555 ret = tun_do_read(tun, tfile, &m->msg_iter, flags & MSG_DONTWAIT);
1556 if (ret > (ssize_t)total_len) {
1557 m->msg_flags |= MSG_TRUNC;
1558 ret = flags & MSG_TRUNC ? ret : total_len;
1559 }
1560 out:
1561 tun_put(tun);
1562 return ret;
1563 }
1564
1565 /* Ops structure to mimic raw sockets with tun */
1566 static const struct proto_ops tun_socket_ops = {
1567 .sendmsg = tun_sendmsg,
1568 .recvmsg = tun_recvmsg,
1569 };
1570
1571 static struct proto tun_proto = {
1572 .name = "tun",
1573 .owner = THIS_MODULE,
1574 .obj_size = sizeof(struct tun_file),
1575 };
1576
1577 static int tun_flags(struct tun_struct *tun)
1578 {
1579 return tun->flags & (TUN_FEATURES | IFF_PERSIST | IFF_TUN | IFF_TAP);
1580 }
1581
1582 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
1583 char *buf)
1584 {
1585 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1586 return sprintf(buf, "0x%x\n", tun_flags(tun));
1587 }
1588
1589 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
1590 char *buf)
1591 {
1592 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1593 return uid_valid(tun->owner)?
1594 sprintf(buf, "%u\n",
1595 from_kuid_munged(current_user_ns(), tun->owner)):
1596 sprintf(buf, "-1\n");
1597 }
1598
1599 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
1600 char *buf)
1601 {
1602 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1603 return gid_valid(tun->group) ?
1604 sprintf(buf, "%u\n",
1605 from_kgid_munged(current_user_ns(), tun->group)):
1606 sprintf(buf, "-1\n");
1607 }
1608
1609 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
1610 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
1611 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
1612
1613 static struct attribute *tun_dev_attrs[] = {
1614 &dev_attr_tun_flags.attr,
1615 &dev_attr_owner.attr,
1616 &dev_attr_group.attr,
1617 NULL
1618 };
1619
1620 static const struct attribute_group tun_attr_group = {
1621 .attrs = tun_dev_attrs
1622 };
1623
1624 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
1625 {
1626 struct tun_struct *tun;
1627 struct tun_file *tfile = file->private_data;
1628 struct net_device *dev;
1629 int err;
1630
1631 if (tfile->detached)
1632 return -EINVAL;
1633
1634 dev = __dev_get_by_name(net, ifr->ifr_name);
1635 if (dev) {
1636 if (ifr->ifr_flags & IFF_TUN_EXCL)
1637 return -EBUSY;
1638 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
1639 tun = netdev_priv(dev);
1640 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
1641 tun = netdev_priv(dev);
1642 else
1643 return -EINVAL;
1644
1645 if (!!(ifr->ifr_flags & IFF_MULTI_QUEUE) !=
1646 !!(tun->flags & IFF_MULTI_QUEUE))
1647 return -EINVAL;
1648
1649 if (tun_not_capable(tun))
1650 return -EPERM;
1651 err = security_tun_dev_open(tun->security);
1652 if (err < 0)
1653 return err;
1654
1655 err = tun_attach(tun, file, ifr->ifr_flags & IFF_NOFILTER);
1656 if (err < 0)
1657 return err;
1658
1659 if (tun->flags & IFF_MULTI_QUEUE &&
1660 (tun->numqueues + tun->numdisabled > 1)) {
1661 /* One or more queue has already been attached, no need
1662 * to initialize the device again.
1663 */
1664 return 0;
1665 }
1666 }
1667 else {
1668 char *name;
1669 unsigned long flags = 0;
1670 int queues = ifr->ifr_flags & IFF_MULTI_QUEUE ?
1671 MAX_TAP_QUEUES : 1;
1672
1673 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1674 return -EPERM;
1675 err = security_tun_dev_create();
1676 if (err < 0)
1677 return err;
1678
1679 /* Set dev type */
1680 if (ifr->ifr_flags & IFF_TUN) {
1681 /* TUN device */
1682 flags |= IFF_TUN;
1683 name = "tun%d";
1684 } else if (ifr->ifr_flags & IFF_TAP) {
1685 /* TAP device */
1686 flags |= IFF_TAP;
1687 name = "tap%d";
1688 } else
1689 return -EINVAL;
1690
1691 if (*ifr->ifr_name)
1692 name = ifr->ifr_name;
1693
1694 dev = alloc_netdev_mqs(sizeof(struct tun_struct), name,
1695 NET_NAME_UNKNOWN, tun_setup, queues,
1696 queues);
1697
1698 if (!dev)
1699 return -ENOMEM;
1700
1701 dev_net_set(dev, net);
1702 dev->rtnl_link_ops = &tun_link_ops;
1703 dev->ifindex = tfile->ifindex;
1704 dev->sysfs_groups[0] = &tun_attr_group;
1705
1706 tun = netdev_priv(dev);
1707 tun->dev = dev;
1708 tun->flags = flags;
1709 tun->txflt.count = 0;
1710 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
1711
1712 tun->align = NET_SKB_PAD;
1713 tun->filter_attached = false;
1714 tun->sndbuf = tfile->socket.sk->sk_sndbuf;
1715
1716 spin_lock_init(&tun->lock);
1717
1718 err = security_tun_dev_alloc_security(&tun->security);
1719 if (err < 0)
1720 goto err_free_dev;
1721
1722 tun_net_init(dev);
1723 tun_flow_init(tun);
1724
1725 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
1726 TUN_USER_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
1727 NETIF_F_HW_VLAN_STAG_TX;
1728 dev->features = dev->hw_features;
1729 dev->vlan_features = dev->features &
1730 ~(NETIF_F_HW_VLAN_CTAG_TX |
1731 NETIF_F_HW_VLAN_STAG_TX);
1732
1733 INIT_LIST_HEAD(&tun->disabled);
1734 err = tun_attach(tun, file, false);
1735 if (err < 0)
1736 goto err_free_flow;
1737
1738 err = register_netdevice(tun->dev);
1739 if (err < 0)
1740 goto err_detach;
1741 }
1742
1743 netif_carrier_on(tun->dev);
1744
1745 tun_debug(KERN_INFO, tun, "tun_set_iff\n");
1746
1747 tun->flags = (tun->flags & ~TUN_FEATURES) |
1748 (ifr->ifr_flags & TUN_FEATURES);
1749
1750 /* Make sure persistent devices do not get stuck in
1751 * xoff state.
1752 */
1753 if (netif_running(tun->dev))
1754 netif_tx_wake_all_queues(tun->dev);
1755
1756 strcpy(ifr->ifr_name, tun->dev->name);
1757 return 0;
1758
1759 err_detach:
1760 tun_detach_all(dev);
1761 err_free_flow:
1762 tun_flow_uninit(tun);
1763 security_tun_dev_free_security(tun->security);
1764 err_free_dev:
1765 free_netdev(dev);
1766 return err;
1767 }
1768
1769 static void tun_get_iff(struct net *net, struct tun_struct *tun,
1770 struct ifreq *ifr)
1771 {
1772 tun_debug(KERN_INFO, tun, "tun_get_iff\n");
1773
1774 strcpy(ifr->ifr_name, tun->dev->name);
1775
1776 ifr->ifr_flags = tun_flags(tun);
1777
1778 }
1779
1780 /* This is like a cut-down ethtool ops, except done via tun fd so no
1781 * privs required. */
1782 static int set_offload(struct tun_struct *tun, unsigned long arg)
1783 {
1784 netdev_features_t features = 0;
1785
1786 if (arg & TUN_F_CSUM) {
1787 features |= NETIF_F_HW_CSUM;
1788 arg &= ~TUN_F_CSUM;
1789
1790 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1791 if (arg & TUN_F_TSO_ECN) {
1792 features |= NETIF_F_TSO_ECN;
1793 arg &= ~TUN_F_TSO_ECN;
1794 }
1795 if (arg & TUN_F_TSO4)
1796 features |= NETIF_F_TSO;
1797 if (arg & TUN_F_TSO6)
1798 features |= NETIF_F_TSO6;
1799 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1800 }
1801
1802 if (arg & TUN_F_UFO) {
1803 features |= NETIF_F_UFO;
1804 arg &= ~TUN_F_UFO;
1805 }
1806 }
1807
1808 /* This gives the user a way to test for new features in future by
1809 * trying to set them. */
1810 if (arg)
1811 return -EINVAL;
1812
1813 tun->set_features = features;
1814 netdev_update_features(tun->dev);
1815
1816 return 0;
1817 }
1818
1819 static void tun_detach_filter(struct tun_struct *tun, int n)
1820 {
1821 int i;
1822 struct tun_file *tfile;
1823
1824 for (i = 0; i < n; i++) {
1825 tfile = rtnl_dereference(tun->tfiles[i]);
1826 __sk_detach_filter(tfile->socket.sk, lockdep_rtnl_is_held());
1827 }
1828
1829 tun->filter_attached = false;
1830 }
1831
1832 static int tun_attach_filter(struct tun_struct *tun)
1833 {
1834 int i, ret = 0;
1835 struct tun_file *tfile;
1836
1837 for (i = 0; i < tun->numqueues; i++) {
1838 tfile = rtnl_dereference(tun->tfiles[i]);
1839 ret = __sk_attach_filter(&tun->fprog, tfile->socket.sk,
1840 lockdep_rtnl_is_held());
1841 if (ret) {
1842 tun_detach_filter(tun, i);
1843 return ret;
1844 }
1845 }
1846
1847 tun->filter_attached = true;
1848 return ret;
1849 }
1850
1851 static void tun_set_sndbuf(struct tun_struct *tun)
1852 {
1853 struct tun_file *tfile;
1854 int i;
1855
1856 for (i = 0; i < tun->numqueues; i++) {
1857 tfile = rtnl_dereference(tun->tfiles[i]);
1858 tfile->socket.sk->sk_sndbuf = tun->sndbuf;
1859 }
1860 }
1861
1862 static int tun_set_queue(struct file *file, struct ifreq *ifr)
1863 {
1864 struct tun_file *tfile = file->private_data;
1865 struct tun_struct *tun;
1866 int ret = 0;
1867
1868 rtnl_lock();
1869
1870 if (ifr->ifr_flags & IFF_ATTACH_QUEUE) {
1871 tun = tfile->detached;
1872 if (!tun) {
1873 ret = -EINVAL;
1874 goto unlock;
1875 }
1876 ret = security_tun_dev_attach_queue(tun->security);
1877 if (ret < 0)
1878 goto unlock;
1879 ret = tun_attach(tun, file, false);
1880 } else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
1881 tun = rtnl_dereference(tfile->tun);
1882 if (!tun || !(tun->flags & IFF_MULTI_QUEUE) || tfile->detached)
1883 ret = -EINVAL;
1884 else
1885 __tun_detach(tfile, false);
1886 } else
1887 ret = -EINVAL;
1888
1889 unlock:
1890 rtnl_unlock();
1891 return ret;
1892 }
1893
1894 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
1895 unsigned long arg, int ifreq_len)
1896 {
1897 struct tun_file *tfile = file->private_data;
1898 struct tun_struct *tun;
1899 void __user* argp = (void __user*)arg;
1900 struct ifreq ifr;
1901 kuid_t owner;
1902 kgid_t group;
1903 int sndbuf;
1904 int vnet_hdr_sz;
1905 unsigned int ifindex;
1906 int le;
1907 int ret;
1908
1909 if (cmd == TUNSETIFF || cmd == TUNSETQUEUE || _IOC_TYPE(cmd) == 0x89) {
1910 if (copy_from_user(&ifr, argp, ifreq_len))
1911 return -EFAULT;
1912 } else {
1913 memset(&ifr, 0, sizeof(ifr));
1914 }
1915 if (cmd == TUNGETFEATURES) {
1916 /* Currently this just means: "what IFF flags are valid?".
1917 * This is needed because we never checked for invalid flags on
1918 * TUNSETIFF.
1919 */
1920 return put_user(IFF_TUN | IFF_TAP | TUN_FEATURES,
1921 (unsigned int __user*)argp);
1922 } else if (cmd == TUNSETQUEUE)
1923 return tun_set_queue(file, &ifr);
1924
1925 ret = 0;
1926 rtnl_lock();
1927
1928 tun = __tun_get(tfile);
1929 if (cmd == TUNSETIFF && !tun) {
1930 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1931
1932 ret = tun_set_iff(sock_net(&tfile->sk), file, &ifr);
1933
1934 if (ret)
1935 goto unlock;
1936
1937 if (copy_to_user(argp, &ifr, ifreq_len))
1938 ret = -EFAULT;
1939 goto unlock;
1940 }
1941 if (cmd == TUNSETIFINDEX) {
1942 ret = -EPERM;
1943 if (tun)
1944 goto unlock;
1945
1946 ret = -EFAULT;
1947 if (copy_from_user(&ifindex, argp, sizeof(ifindex)))
1948 goto unlock;
1949
1950 ret = 0;
1951 tfile->ifindex = ifindex;
1952 goto unlock;
1953 }
1954
1955 ret = -EBADFD;
1956 if (!tun)
1957 goto unlock;
1958
1959 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %u\n", cmd);
1960
1961 ret = 0;
1962 switch (cmd) {
1963 case TUNGETIFF:
1964 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1965
1966 if (tfile->detached)
1967 ifr.ifr_flags |= IFF_DETACH_QUEUE;
1968 if (!tfile->socket.sk->sk_filter)
1969 ifr.ifr_flags |= IFF_NOFILTER;
1970
1971 if (copy_to_user(argp, &ifr, ifreq_len))
1972 ret = -EFAULT;
1973 break;
1974
1975 case TUNSETNOCSUM:
1976 /* Disable/Enable checksum */
1977
1978 /* [unimplemented] */
1979 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n",
1980 arg ? "disabled" : "enabled");
1981 break;
1982
1983 case TUNSETPERSIST:
1984 /* Disable/Enable persist mode. Keep an extra reference to the
1985 * module to prevent the module being unprobed.
1986 */
1987 if (arg && !(tun->flags & IFF_PERSIST)) {
1988 tun->flags |= IFF_PERSIST;
1989 __module_get(THIS_MODULE);
1990 }
1991 if (!arg && (tun->flags & IFF_PERSIST)) {
1992 tun->flags &= ~IFF_PERSIST;
1993 module_put(THIS_MODULE);
1994 }
1995
1996 tun_debug(KERN_INFO, tun, "persist %s\n",
1997 arg ? "enabled" : "disabled");
1998 break;
1999
2000 case TUNSETOWNER:
2001 /* Set owner of the device */
2002 owner = make_kuid(current_user_ns(), arg);
2003 if (!uid_valid(owner)) {
2004 ret = -EINVAL;
2005 break;
2006 }
2007 tun->owner = owner;
2008 tun_debug(KERN_INFO, tun, "owner set to %u\n",
2009 from_kuid(&init_user_ns, tun->owner));
2010 break;
2011
2012 case TUNSETGROUP:
2013 /* Set group of the device */
2014 group = make_kgid(current_user_ns(), arg);
2015 if (!gid_valid(group)) {
2016 ret = -EINVAL;
2017 break;
2018 }
2019 tun->group = group;
2020 tun_debug(KERN_INFO, tun, "group set to %u\n",
2021 from_kgid(&init_user_ns, tun->group));
2022 break;
2023
2024 case TUNSETLINK:
2025 /* Only allow setting the type when the interface is down */
2026 if (tun->dev->flags & IFF_UP) {
2027 tun_debug(KERN_INFO, tun,
2028 "Linktype set failed because interface is up\n");
2029 ret = -EBUSY;
2030 } else {
2031 tun->dev->type = (int) arg;
2032 tun_debug(KERN_INFO, tun, "linktype set to %d\n",
2033 tun->dev->type);
2034 ret = 0;
2035 }
2036 break;
2037
2038 #ifdef TUN_DEBUG
2039 case TUNSETDEBUG:
2040 tun->debug = arg;
2041 break;
2042 #endif
2043 case TUNSETOFFLOAD:
2044 ret = set_offload(tun, arg);
2045 break;
2046
2047 case TUNSETTXFILTER:
2048 /* Can be set only for TAPs */
2049 ret = -EINVAL;
2050 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2051 break;
2052 ret = update_filter(&tun->txflt, (void __user *)arg);
2053 break;
2054
2055 case SIOCGIFHWADDR:
2056 /* Get hw address */
2057 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
2058 ifr.ifr_hwaddr.sa_family = tun->dev->type;
2059 if (copy_to_user(argp, &ifr, ifreq_len))
2060 ret = -EFAULT;
2061 break;
2062
2063 case SIOCSIFHWADDR:
2064 /* Set hw address */
2065 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
2066 ifr.ifr_hwaddr.sa_data);
2067
2068 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
2069 break;
2070
2071 case TUNGETSNDBUF:
2072 sndbuf = tfile->socket.sk->sk_sndbuf;
2073 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
2074 ret = -EFAULT;
2075 break;
2076
2077 case TUNSETSNDBUF:
2078 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
2079 ret = -EFAULT;
2080 break;
2081 }
2082
2083 tun->sndbuf = sndbuf;
2084 tun_set_sndbuf(tun);
2085 break;
2086
2087 case TUNGETVNETHDRSZ:
2088 vnet_hdr_sz = tun->vnet_hdr_sz;
2089 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
2090 ret = -EFAULT;
2091 break;
2092
2093 case TUNSETVNETHDRSZ:
2094 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
2095 ret = -EFAULT;
2096 break;
2097 }
2098 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
2099 ret = -EINVAL;
2100 break;
2101 }
2102
2103 tun->vnet_hdr_sz = vnet_hdr_sz;
2104 break;
2105
2106 case TUNGETVNETLE:
2107 le = !!(tun->flags & TUN_VNET_LE);
2108 if (put_user(le, (int __user *)argp))
2109 ret = -EFAULT;
2110 break;
2111
2112 case TUNSETVNETLE:
2113 if (get_user(le, (int __user *)argp)) {
2114 ret = -EFAULT;
2115 break;
2116 }
2117 if (le)
2118 tun->flags |= TUN_VNET_LE;
2119 else
2120 tun->flags &= ~TUN_VNET_LE;
2121 break;
2122
2123 case TUNGETVNETBE:
2124 ret = tun_get_vnet_be(tun, argp);
2125 break;
2126
2127 case TUNSETVNETBE:
2128 ret = tun_set_vnet_be(tun, argp);
2129 break;
2130
2131 case TUNATTACHFILTER:
2132 /* Can be set only for TAPs */
2133 ret = -EINVAL;
2134 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2135 break;
2136 ret = -EFAULT;
2137 if (copy_from_user(&tun->fprog, argp, sizeof(tun->fprog)))
2138 break;
2139
2140 ret = tun_attach_filter(tun);
2141 break;
2142
2143 case TUNDETACHFILTER:
2144 /* Can be set only for TAPs */
2145 ret = -EINVAL;
2146 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2147 break;
2148 ret = 0;
2149 tun_detach_filter(tun, tun->numqueues);
2150 break;
2151
2152 case TUNGETFILTER:
2153 ret = -EINVAL;
2154 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2155 break;
2156 ret = -EFAULT;
2157 if (copy_to_user(argp, &tun->fprog, sizeof(tun->fprog)))
2158 break;
2159 ret = 0;
2160 break;
2161
2162 default:
2163 ret = -EINVAL;
2164 break;
2165 }
2166
2167 unlock:
2168 rtnl_unlock();
2169 if (tun)
2170 tun_put(tun);
2171 return ret;
2172 }
2173
2174 static long tun_chr_ioctl(struct file *file,
2175 unsigned int cmd, unsigned long arg)
2176 {
2177 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
2178 }
2179
2180 #ifdef CONFIG_COMPAT
2181 static long tun_chr_compat_ioctl(struct file *file,
2182 unsigned int cmd, unsigned long arg)
2183 {
2184 switch (cmd) {
2185 case TUNSETIFF:
2186 case TUNGETIFF:
2187 case TUNSETTXFILTER:
2188 case TUNGETSNDBUF:
2189 case TUNSETSNDBUF:
2190 case SIOCGIFHWADDR:
2191 case SIOCSIFHWADDR:
2192 arg = (unsigned long)compat_ptr(arg);
2193 break;
2194 default:
2195 arg = (compat_ulong_t)arg;
2196 break;
2197 }
2198
2199 /*
2200 * compat_ifreq is shorter than ifreq, so we must not access beyond
2201 * the end of that structure. All fields that are used in this
2202 * driver are compatible though, we don't need to convert the
2203 * contents.
2204 */
2205 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
2206 }
2207 #endif /* CONFIG_COMPAT */
2208
2209 static int tun_chr_fasync(int fd, struct file *file, int on)
2210 {
2211 struct tun_file *tfile = file->private_data;
2212 int ret;
2213
2214 if ((ret = fasync_helper(fd, file, on, &tfile->fasync)) < 0)
2215 goto out;
2216
2217 if (on) {
2218 __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
2219 tfile->flags |= TUN_FASYNC;
2220 } else
2221 tfile->flags &= ~TUN_FASYNC;
2222 ret = 0;
2223 out:
2224 return ret;
2225 }
2226
2227 static int tun_chr_open(struct inode *inode, struct file * file)
2228 {
2229 struct net *net = current->nsproxy->net_ns;
2230 struct tun_file *tfile;
2231
2232 DBG1(KERN_INFO, "tunX: tun_chr_open\n");
2233
2234 tfile = (struct tun_file *)sk_alloc(net, AF_UNSPEC, GFP_KERNEL,
2235 &tun_proto, 0);
2236 if (!tfile)
2237 return -ENOMEM;
2238 RCU_INIT_POINTER(tfile->tun, NULL);
2239 tfile->flags = 0;
2240 tfile->ifindex = 0;
2241
2242 init_waitqueue_head(&tfile->wq.wait);
2243 RCU_INIT_POINTER(tfile->socket.wq, &tfile->wq);
2244
2245 tfile->socket.file = file;
2246 tfile->socket.ops = &tun_socket_ops;
2247
2248 sock_init_data(&tfile->socket, &tfile->sk);
2249
2250 tfile->sk.sk_write_space = tun_sock_write_space;
2251 tfile->sk.sk_sndbuf = INT_MAX;
2252
2253 file->private_data = tfile;
2254 INIT_LIST_HEAD(&tfile->next);
2255
2256 sock_set_flag(&tfile->sk, SOCK_ZEROCOPY);
2257
2258 return 0;
2259 }
2260
2261 static int tun_chr_close(struct inode *inode, struct file *file)
2262 {
2263 struct tun_file *tfile = file->private_data;
2264
2265 tun_detach(tfile, true);
2266
2267 return 0;
2268 }
2269
2270 #ifdef CONFIG_PROC_FS
2271 static void tun_chr_show_fdinfo(struct seq_file *m, struct file *f)
2272 {
2273 struct tun_struct *tun;
2274 struct ifreq ifr;
2275
2276 memset(&ifr, 0, sizeof(ifr));
2277
2278 rtnl_lock();
2279 tun = tun_get(f);
2280 if (tun)
2281 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
2282 rtnl_unlock();
2283
2284 if (tun)
2285 tun_put(tun);
2286
2287 seq_printf(m, "iff:\t%s\n", ifr.ifr_name);
2288 }
2289 #endif
2290
2291 static const struct file_operations tun_fops = {
2292 .owner = THIS_MODULE,
2293 .llseek = no_llseek,
2294 .read_iter = tun_chr_read_iter,
2295 .write_iter = tun_chr_write_iter,
2296 .poll = tun_chr_poll,
2297 .unlocked_ioctl = tun_chr_ioctl,
2298 #ifdef CONFIG_COMPAT
2299 .compat_ioctl = tun_chr_compat_ioctl,
2300 #endif
2301 .open = tun_chr_open,
2302 .release = tun_chr_close,
2303 .fasync = tun_chr_fasync,
2304 #ifdef CONFIG_PROC_FS
2305 .show_fdinfo = tun_chr_show_fdinfo,
2306 #endif
2307 };
2308
2309 static struct miscdevice tun_miscdev = {
2310 .minor = TUN_MINOR,
2311 .name = "tun",
2312 .nodename = "net/tun",
2313 .fops = &tun_fops,
2314 };
2315
2316 /* ethtool interface */
2317
2318 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
2319 {
2320 cmd->supported = 0;
2321 cmd->advertising = 0;
2322 ethtool_cmd_speed_set(cmd, SPEED_10);
2323 cmd->duplex = DUPLEX_FULL;
2324 cmd->port = PORT_TP;
2325 cmd->phy_address = 0;
2326 cmd->transceiver = XCVR_INTERNAL;
2327 cmd->autoneg = AUTONEG_DISABLE;
2328 cmd->maxtxpkt = 0;
2329 cmd->maxrxpkt = 0;
2330 return 0;
2331 }
2332
2333 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
2334 {
2335 struct tun_struct *tun = netdev_priv(dev);
2336
2337 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
2338 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
2339
2340 switch (tun->flags & TUN_TYPE_MASK) {
2341 case IFF_TUN:
2342 strlcpy(info->bus_info, "tun", sizeof(info->bus_info));
2343 break;
2344 case IFF_TAP:
2345 strlcpy(info->bus_info, "tap", sizeof(info->bus_info));
2346 break;
2347 }
2348 }
2349
2350 static u32 tun_get_msglevel(struct net_device *dev)
2351 {
2352 #ifdef TUN_DEBUG
2353 struct tun_struct *tun = netdev_priv(dev);
2354 return tun->debug;
2355 #else
2356 return -EOPNOTSUPP;
2357 #endif
2358 }
2359
2360 static void tun_set_msglevel(struct net_device *dev, u32 value)
2361 {
2362 #ifdef TUN_DEBUG
2363 struct tun_struct *tun = netdev_priv(dev);
2364 tun->debug = value;
2365 #endif
2366 }
2367
2368 static const struct ethtool_ops tun_ethtool_ops = {
2369 .get_settings = tun_get_settings,
2370 .get_drvinfo = tun_get_drvinfo,
2371 .get_msglevel = tun_get_msglevel,
2372 .set_msglevel = tun_set_msglevel,
2373 .get_link = ethtool_op_get_link,
2374 .get_ts_info = ethtool_op_get_ts_info,
2375 };
2376
2377
2378 static int __init tun_init(void)
2379 {
2380 int ret = 0;
2381
2382 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
2383 pr_info("%s\n", DRV_COPYRIGHT);
2384
2385 ret = rtnl_link_register(&tun_link_ops);
2386 if (ret) {
2387 pr_err("Can't register link_ops\n");
2388 goto err_linkops;
2389 }
2390
2391 ret = misc_register(&tun_miscdev);
2392 if (ret) {
2393 pr_err("Can't register misc device %d\n", TUN_MINOR);
2394 goto err_misc;
2395 }
2396 return 0;
2397 err_misc:
2398 rtnl_link_unregister(&tun_link_ops);
2399 err_linkops:
2400 return ret;
2401 }
2402
2403 static void tun_cleanup(void)
2404 {
2405 misc_deregister(&tun_miscdev);
2406 rtnl_link_unregister(&tun_link_ops);
2407 }
2408
2409 /* Get an underlying socket object from tun file. Returns error unless file is
2410 * attached to a device. The returned object works like a packet socket, it
2411 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
2412 * holding a reference to the file for as long as the socket is in use. */
2413 struct socket *tun_get_socket(struct file *file)
2414 {
2415 struct tun_file *tfile;
2416 if (file->f_op != &tun_fops)
2417 return ERR_PTR(-EINVAL);
2418 tfile = file->private_data;
2419 if (!tfile)
2420 return ERR_PTR(-EBADFD);
2421 return &tfile->socket;
2422 }
2423 EXPORT_SYMBOL_GPL(tun_get_socket);
2424
2425 module_init(tun_init);
2426 module_exit(tun_cleanup);
2427 MODULE_DESCRIPTION(DRV_DESCRIPTION);
2428 MODULE_AUTHOR(DRV_COPYRIGHT);
2429 MODULE_LICENSE("GPL");
2430 MODULE_ALIAS_MISCDEV(TUN_MINOR);
2431 MODULE_ALIAS("devname:net/tun");
Linux with added FPC-III support