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sched: Remove double_rq_lock() from __migrate_task()
[linux/fpc-iii.git] / drivers / net / tun.c
blob98bad1fb1bfb1ce66ea4219c2e767256f05d6cbb
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
74 #include <asm/uaccess.h>
75
76 /* Uncomment to enable debugging */
77 /* #define TUN_DEBUG 1 */
78
79 #ifdef TUN_DEBUG
80 static int debug;
81
82 #define tun_debug(level, tun, fmt, args...) \
83 do { \
84 if (tun->debug) \
85 netdev_printk(level, tun->dev, fmt, ##args); \
86 } while (0)
87 #define DBG1(level, fmt, args...) \
88 do { \
89 if (debug == 2) \
90 printk(level fmt, ##args); \
91 } while (0)
92 #else
93 #define tun_debug(level, tun, fmt, args...) \
94 do { \
95 if (0) \
96 netdev_printk(level, tun->dev, fmt, ##args); \
97 } while (0)
98 #define DBG1(level, fmt, args...) \
99 do { \
100 if (0) \
101 printk(level fmt, ##args); \
102 } while (0)
103 #endif
104
105 #define GOODCOPY_LEN 128
106
107 #define FLT_EXACT_COUNT 8
108 struct tap_filter {
109 unsigned int count; /* Number of addrs. Zero means disabled */
110 u32 mask[2]; /* Mask of the hashed addrs */
111 unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN];
112 };
113
114 /* DEFAULT_MAX_NUM_RSS_QUEUES were chosen to let the rx/tx queues allocated for
115 * the netdevice to be fit in one page. So we can make sure the success of
116 * memory allocation. TODO: increase the limit. */
117 #define MAX_TAP_QUEUES DEFAULT_MAX_NUM_RSS_QUEUES
118 #define MAX_TAP_FLOWS 4096
119
120 #define TUN_FLOW_EXPIRE (3 * HZ)
121
122 /* A tun_file connects an open character device to a tuntap netdevice. It
123 * also contains all socket related structures (except sock_fprog and tap_filter)
124 * to serve as one transmit queue for tuntap device. The sock_fprog and
125 * tap_filter were kept in tun_struct since they were used for filtering for the
126 * netdevice not for a specific queue (at least I didn't see the requirement for
127 * this).
128 *
129 * RCU usage:
130 * The tun_file and tun_struct are loosely coupled, the pointer from one to the
131 * other can only be read while rcu_read_lock or rtnl_lock is held.
132 */
133 struct tun_file {
134 struct sock sk;
135 struct socket socket;
136 struct socket_wq wq;
137 struct tun_struct __rcu *tun;
138 struct net *net;
139 struct fasync_struct *fasync;
140 /* only used for fasnyc */
141 unsigned int flags;
142 union {
143 u16 queue_index;
144 unsigned int ifindex;
145 };
146 struct list_head next;
147 struct tun_struct *detached;
148 };
149
150 struct tun_flow_entry {
151 struct hlist_node hash_link;
152 struct rcu_head rcu;
153 struct tun_struct *tun;
154
155 u32 rxhash;
156 u32 rps_rxhash;
157 int queue_index;
158 unsigned long updated;
159 };
160
161 #define TUN_NUM_FLOW_ENTRIES 1024
162
163 /* Since the socket were moved to tun_file, to preserve the behavior of persist
164 * device, socket filter, sndbuf and vnet header size were restore when the
165 * file were attached to a persist device.
166 */
167 struct tun_struct {
168 struct tun_file __rcu *tfiles[MAX_TAP_QUEUES];
169 unsigned int numqueues;
170 unsigned int flags;
171 kuid_t owner;
172 kgid_t group;
173
174 struct net_device *dev;
175 netdev_features_t set_features;
176 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
177 NETIF_F_TSO6|NETIF_F_UFO)
178
179 int vnet_hdr_sz;
180 int sndbuf;
181 struct tap_filter txflt;
182 struct sock_fprog fprog;
183 /* protected by rtnl lock */
184 bool filter_attached;
185 #ifdef TUN_DEBUG
186 int debug;
187 #endif
188 spinlock_t lock;
189 struct hlist_head flows[TUN_NUM_FLOW_ENTRIES];
190 struct timer_list flow_gc_timer;
191 unsigned long ageing_time;
192 unsigned int numdisabled;
193 struct list_head disabled;
194 void *security;
195 u32 flow_count;
196 };
197
198 static inline u32 tun_hashfn(u32 rxhash)
199 {
200 return rxhash & 0x3ff;
201 }
202
203 static struct tun_flow_entry *tun_flow_find(struct hlist_head *head, u32 rxhash)
204 {
205 struct tun_flow_entry *e;
206
207 hlist_for_each_entry_rcu(e, head, hash_link) {
208 if (e->rxhash == rxhash)
209 return e;
210 }
211 return NULL;
212 }
213
214 static struct tun_flow_entry *tun_flow_create(struct tun_struct *tun,
215 struct hlist_head *head,
216 u32 rxhash, u16 queue_index)
217 {
218 struct tun_flow_entry *e = kmalloc(sizeof(*e), GFP_ATOMIC);
219
220 if (e) {
221 tun_debug(KERN_INFO, tun, "create flow: hash %u index %u\n",
222 rxhash, queue_index);
223 e->updated = jiffies;
224 e->rxhash = rxhash;
225 e->rps_rxhash = 0;
226 e->queue_index = queue_index;
227 e->tun = tun;
228 hlist_add_head_rcu(&e->hash_link, head);
229 ++tun->flow_count;
230 }
231 return e;
232 }
233
234 static void tun_flow_delete(struct tun_struct *tun, struct tun_flow_entry *e)
235 {
236 tun_debug(KERN_INFO, tun, "delete flow: hash %u index %u\n",
237 e->rxhash, e->queue_index);
238 sock_rps_reset_flow_hash(e->rps_rxhash);
239 hlist_del_rcu(&e->hash_link);
240 kfree_rcu(e, rcu);
241 --tun->flow_count;
242 }
243
244 static void tun_flow_flush(struct tun_struct *tun)
245 {
246 int i;
247
248 spin_lock_bh(&tun->lock);
249 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
250 struct tun_flow_entry *e;
251 struct hlist_node *n;
252
253 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link)
254 tun_flow_delete(tun, e);
255 }
256 spin_unlock_bh(&tun->lock);
257 }
258
259 static void tun_flow_delete_by_queue(struct tun_struct *tun, u16 queue_index)
260 {
261 int i;
262
263 spin_lock_bh(&tun->lock);
264 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
265 struct tun_flow_entry *e;
266 struct hlist_node *n;
267
268 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
269 if (e->queue_index == queue_index)
270 tun_flow_delete(tun, e);
271 }
272 }
273 spin_unlock_bh(&tun->lock);
274 }
275
276 static void tun_flow_cleanup(unsigned long data)
277 {
278 struct tun_struct *tun = (struct tun_struct *)data;
279 unsigned long delay = tun->ageing_time;
280 unsigned long next_timer = jiffies + delay;
281 unsigned long count = 0;
282 int i;
283
284 tun_debug(KERN_INFO, tun, "tun_flow_cleanup\n");
285
286 spin_lock_bh(&tun->lock);
287 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
288 struct tun_flow_entry *e;
289 struct hlist_node *n;
290
291 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
292 unsigned long this_timer;
293 count++;
294 this_timer = e->updated + delay;
295 if (time_before_eq(this_timer, jiffies))
296 tun_flow_delete(tun, e);
297 else if (time_before(this_timer, next_timer))
298 next_timer = this_timer;
299 }
300 }
301
302 if (count)
303 mod_timer(&tun->flow_gc_timer, round_jiffies_up(next_timer));
304 spin_unlock_bh(&tun->lock);
305 }
306
307 static void tun_flow_update(struct tun_struct *tun, u32 rxhash,
308 struct tun_file *tfile)
309 {
310 struct hlist_head *head;
311 struct tun_flow_entry *e;
312 unsigned long delay = tun->ageing_time;
313 u16 queue_index = tfile->queue_index;
314
315 if (!rxhash)
316 return;
317 else
318 head = &tun->flows[tun_hashfn(rxhash)];
319
320 rcu_read_lock();
321
322 /* We may get a very small possibility of OOO during switching, not
323 * worth to optimize.*/
324 if (tun->numqueues == 1 || tfile->detached)
325 goto unlock;
326
327 e = tun_flow_find(head, rxhash);
328 if (likely(e)) {
329 /* TODO: keep queueing to old queue until it's empty? */
330 e->queue_index = queue_index;
331 e->updated = jiffies;
332 sock_rps_record_flow_hash(e->rps_rxhash);
333 } else {
334 spin_lock_bh(&tun->lock);
335 if (!tun_flow_find(head, rxhash) &&
336 tun->flow_count < MAX_TAP_FLOWS)
337 tun_flow_create(tun, head, rxhash, queue_index);
338
339 if (!timer_pending(&tun->flow_gc_timer))
340 mod_timer(&tun->flow_gc_timer,
341 round_jiffies_up(jiffies + delay));
342 spin_unlock_bh(&tun->lock);
343 }
344
345 unlock:
346 rcu_read_unlock();
347 }
348
349 /**
350 * Save the hash received in the stack receive path and update the
351 * flow_hash table accordingly.
352 */
353 static inline void tun_flow_save_rps_rxhash(struct tun_flow_entry *e, u32 hash)
354 {
355 if (unlikely(e->rps_rxhash != hash)) {
356 sock_rps_reset_flow_hash(e->rps_rxhash);
357 e->rps_rxhash = hash;
358 }
359 }
360
361 /* We try to identify a flow through its rxhash first. The reason that
362 * we do not check rxq no. is because some cards(e.g 82599), chooses
363 * the rxq based on the txq where the last packet of the flow comes. As
364 * the userspace application move between processors, we may get a
365 * different rxq no. here. If we could not get rxhash, then we would
366 * hope the rxq no. may help here.
367 */
368 static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb,
369 void *accel_priv, select_queue_fallback_t fallback)
370 {
371 struct tun_struct *tun = netdev_priv(dev);
372 struct tun_flow_entry *e;
373 u32 txq = 0;
374 u32 numqueues = 0;
375
376 rcu_read_lock();
377 numqueues = ACCESS_ONCE(tun->numqueues);
378
379 txq = skb_get_hash(skb);
380 if (txq) {
381 e = tun_flow_find(&tun->flows[tun_hashfn(txq)], txq);
382 if (e) {
383 tun_flow_save_rps_rxhash(e, txq);
384 txq = e->queue_index;
385 } else
386 /* use multiply and shift instead of expensive divide */
387 txq = ((u64)txq * numqueues) >> 32;
388 } else if (likely(skb_rx_queue_recorded(skb))) {
389 txq = skb_get_rx_queue(skb);
390 while (unlikely(txq >= numqueues))
391 txq -= numqueues;
392 }
393
394 rcu_read_unlock();
395 return txq;
396 }
397
398 static inline bool tun_not_capable(struct tun_struct *tun)
399 {
400 const struct cred *cred = current_cred();
401 struct net *net = dev_net(tun->dev);
402
403 return ((uid_valid(tun->owner) && !uid_eq(cred->euid, tun->owner)) ||
404 (gid_valid(tun->group) && !in_egroup_p(tun->group))) &&
405 !ns_capable(net->user_ns, CAP_NET_ADMIN);
406 }
407
408 static void tun_set_real_num_queues(struct tun_struct *tun)
409 {
410 netif_set_real_num_tx_queues(tun->dev, tun->numqueues);
411 netif_set_real_num_rx_queues(tun->dev, tun->numqueues);
412 }
413
414 static void tun_disable_queue(struct tun_struct *tun, struct tun_file *tfile)
415 {
416 tfile->detached = tun;
417 list_add_tail(&tfile->next, &tun->disabled);
418 ++tun->numdisabled;
419 }
420
421 static struct tun_struct *tun_enable_queue(struct tun_file *tfile)
422 {
423 struct tun_struct *tun = tfile->detached;
424
425 tfile->detached = NULL;
426 list_del_init(&tfile->next);
427 --tun->numdisabled;
428 return tun;
429 }
430
431 static void tun_queue_purge(struct tun_file *tfile)
432 {
433 skb_queue_purge(&tfile->sk.sk_receive_queue);
434 skb_queue_purge(&tfile->sk.sk_error_queue);
435 }
436
437 static void __tun_detach(struct tun_file *tfile, bool clean)
438 {
439 struct tun_file *ntfile;
440 struct tun_struct *tun;
441
442 tun = rtnl_dereference(tfile->tun);
443
444 if (tun && !tfile->detached) {
445 u16 index = tfile->queue_index;
446 BUG_ON(index >= tun->numqueues);
447
448 rcu_assign_pointer(tun->tfiles[index],
449 tun->tfiles[tun->numqueues - 1]);
450 ntfile = rtnl_dereference(tun->tfiles[index]);
451 ntfile->queue_index = index;
452
453 --tun->numqueues;
454 if (clean) {
455 RCU_INIT_POINTER(tfile->tun, NULL);
456 sock_put(&tfile->sk);
457 } else
458 tun_disable_queue(tun, tfile);
459
460 synchronize_net();
461 tun_flow_delete_by_queue(tun, tun->numqueues + 1);
462 /* Drop read queue */
463 tun_queue_purge(tfile);
464 tun_set_real_num_queues(tun);
465 } else if (tfile->detached && clean) {
466 tun = tun_enable_queue(tfile);
467 sock_put(&tfile->sk);
468 }
469
470 if (clean) {
471 if (tun && tun->numqueues == 0 && tun->numdisabled == 0) {
472 netif_carrier_off(tun->dev);
473
474 if (!(tun->flags & TUN_PERSIST) &&
475 tun->dev->reg_state == NETREG_REGISTERED)
476 unregister_netdevice(tun->dev);
477 }
478
479 BUG_ON(!test_bit(SOCK_EXTERNALLY_ALLOCATED,
480 &tfile->socket.flags));
481 sk_release_kernel(&tfile->sk);
482 }
483 }
484
485 static void tun_detach(struct tun_file *tfile, bool clean)
486 {
487 rtnl_lock();
488 __tun_detach(tfile, clean);
489 rtnl_unlock();
490 }
491
492 static void tun_detach_all(struct net_device *dev)
493 {
494 struct tun_struct *tun = netdev_priv(dev);
495 struct tun_file *tfile, *tmp;
496 int i, n = tun->numqueues;
497
498 for (i = 0; i < n; i++) {
499 tfile = rtnl_dereference(tun->tfiles[i]);
500 BUG_ON(!tfile);
501 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
502 RCU_INIT_POINTER(tfile->tun, NULL);
503 --tun->numqueues;
504 }
505 list_for_each_entry(tfile, &tun->disabled, next) {
506 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
507 RCU_INIT_POINTER(tfile->tun, NULL);
508 }
509 BUG_ON(tun->numqueues != 0);
510
511 synchronize_net();
512 for (i = 0; i < n; i++) {
513 tfile = rtnl_dereference(tun->tfiles[i]);
514 /* Drop read queue */
515 tun_queue_purge(tfile);
516 sock_put(&tfile->sk);
517 }
518 list_for_each_entry_safe(tfile, tmp, &tun->disabled, next) {
519 tun_enable_queue(tfile);
520 tun_queue_purge(tfile);
521 sock_put(&tfile->sk);
522 }
523 BUG_ON(tun->numdisabled != 0);
524
525 if (tun->flags & TUN_PERSIST)
526 module_put(THIS_MODULE);
527 }
528
529 static int tun_attach(struct tun_struct *tun, struct file *file, bool skip_filter)
530 {
531 struct tun_file *tfile = file->private_data;
532 int err;
533
534 err = security_tun_dev_attach(tfile->socket.sk, tun->security);
535 if (err < 0)
536 goto out;
537
538 err = -EINVAL;
539 if (rtnl_dereference(tfile->tun) && !tfile->detached)
540 goto out;
541
542 err = -EBUSY;
543 if (!(tun->flags & TUN_TAP_MQ) && tun->numqueues == 1)
544 goto out;
545
546 err = -E2BIG;
547 if (!tfile->detached &&
548 tun->numqueues + tun->numdisabled == MAX_TAP_QUEUES)
549 goto out;
550
551 err = 0;
552
553 /* Re-attach the filter to persist device */
554 if (!skip_filter && (tun->filter_attached == true)) {
555 err = sk_attach_filter(&tun->fprog, tfile->socket.sk);
556 if (!err)
557 goto out;
558 }
559 tfile->queue_index = tun->numqueues;
560 rcu_assign_pointer(tfile->tun, tun);
561 rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile);
562 tun->numqueues++;
563
564 if (tfile->detached)
565 tun_enable_queue(tfile);
566 else
567 sock_hold(&tfile->sk);
568
569 tun_set_real_num_queues(tun);
570
571 /* device is allowed to go away first, so no need to hold extra
572 * refcnt.
573 */
574
575 out:
576 return err;
577 }
578
579 static struct tun_struct *__tun_get(struct tun_file *tfile)
580 {
581 struct tun_struct *tun;
582
583 rcu_read_lock();
584 tun = rcu_dereference(tfile->tun);
585 if (tun)
586 dev_hold(tun->dev);
587 rcu_read_unlock();
588
589 return tun;
590 }
591
592 static struct tun_struct *tun_get(struct file *file)
593 {
594 return __tun_get(file->private_data);
595 }
596
597 static void tun_put(struct tun_struct *tun)
598 {
599 dev_put(tun->dev);
600 }
601
602 /* TAP filtering */
603 static void addr_hash_set(u32 *mask, const u8 *addr)
604 {
605 int n = ether_crc(ETH_ALEN, addr) >> 26;
606 mask[n >> 5] |= (1 << (n & 31));
607 }
608
609 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
610 {
611 int n = ether_crc(ETH_ALEN, addr) >> 26;
612 return mask[n >> 5] & (1 << (n & 31));
613 }
614
615 static int update_filter(struct tap_filter *filter, void __user *arg)
616 {
617 struct { u8 u[ETH_ALEN]; } *addr;
618 struct tun_filter uf;
619 int err, alen, n, nexact;
620
621 if (copy_from_user(&uf, arg, sizeof(uf)))
622 return -EFAULT;
623
624 if (!uf.count) {
625 /* Disabled */
626 filter->count = 0;
627 return 0;
628 }
629
630 alen = ETH_ALEN * uf.count;
631 addr = kmalloc(alen, GFP_KERNEL);
632 if (!addr)
633 return -ENOMEM;
634
635 if (copy_from_user(addr, arg + sizeof(uf), alen)) {
636 err = -EFAULT;
637 goto done;
638 }
639
640 /* The filter is updated without holding any locks. Which is
641 * perfectly safe. We disable it first and in the worst
642 * case we'll accept a few undesired packets. */
643 filter->count = 0;
644 wmb();
645
646 /* Use first set of addresses as an exact filter */
647 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
648 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
649
650 nexact = n;
651
652 /* Remaining multicast addresses are hashed,
653 * unicast will leave the filter disabled. */
654 memset(filter->mask, 0, sizeof(filter->mask));
655 for (; n < uf.count; n++) {
656 if (!is_multicast_ether_addr(addr[n].u)) {
657 err = 0; /* no filter */
658 goto done;
659 }
660 addr_hash_set(filter->mask, addr[n].u);
661 }
662
663 /* For ALLMULTI just set the mask to all ones.
664 * This overrides the mask populated above. */
665 if ((uf.flags & TUN_FLT_ALLMULTI))
666 memset(filter->mask, ~0, sizeof(filter->mask));
667
668 /* Now enable the filter */
669 wmb();
670 filter->count = nexact;
671
672 /* Return the number of exact filters */
673 err = nexact;
674
675 done:
676 kfree(addr);
677 return err;
678 }
679
680 /* Returns: 0 - drop, !=0 - accept */
681 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
682 {
683 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
684 * at this point. */
685 struct ethhdr *eh = (struct ethhdr *) skb->data;
686 int i;
687
688 /* Exact match */
689 for (i = 0; i < filter->count; i++)
690 if (ether_addr_equal(eh->h_dest, filter->addr[i]))
691 return 1;
692
693 /* Inexact match (multicast only) */
694 if (is_multicast_ether_addr(eh->h_dest))
695 return addr_hash_test(filter->mask, eh->h_dest);
696
697 return 0;
698 }
699
700 /*
701 * Checks whether the packet is accepted or not.
702 * Returns: 0 - drop, !=0 - accept
703 */
704 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
705 {
706 if (!filter->count)
707 return 1;
708
709 return run_filter(filter, skb);
710 }
711
712 /* Network device part of the driver */
713
714 static const struct ethtool_ops tun_ethtool_ops;
715
716 /* Net device detach from fd. */
717 static void tun_net_uninit(struct net_device *dev)
718 {
719 tun_detach_all(dev);
720 }
721
722 /* Net device open. */
723 static int tun_net_open(struct net_device *dev)
724 {
725 netif_tx_start_all_queues(dev);
726 return 0;
727 }
728
729 /* Net device close. */
730 static int tun_net_close(struct net_device *dev)
731 {
732 netif_tx_stop_all_queues(dev);
733 return 0;
734 }
735
736 /* Net device start xmit */
737 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
738 {
739 struct tun_struct *tun = netdev_priv(dev);
740 int txq = skb->queue_mapping;
741 struct tun_file *tfile;
742 u32 numqueues = 0;
743
744 rcu_read_lock();
745 tfile = rcu_dereference(tun->tfiles[txq]);
746 numqueues = ACCESS_ONCE(tun->numqueues);
747
748 /* Drop packet if interface is not attached */
749 if (txq >= numqueues)
750 goto drop;
751
752 if (numqueues == 1) {
753 /* Select queue was not called for the skbuff, so we extract the
754 * RPS hash and save it into the flow_table here.
755 */
756 __u32 rxhash;
757
758 rxhash = skb_get_hash(skb);
759 if (rxhash) {
760 struct tun_flow_entry *e;
761 e = tun_flow_find(&tun->flows[tun_hashfn(rxhash)],
762 rxhash);
763 if (e)
764 tun_flow_save_rps_rxhash(e, rxhash);
765 }
766 }
767
768 tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len);
769
770 BUG_ON(!tfile);
771
772 /* Drop if the filter does not like it.
773 * This is a noop if the filter is disabled.
774 * Filter can be enabled only for the TAP devices. */
775 if (!check_filter(&tun->txflt, skb))
776 goto drop;
777
778 if (tfile->socket.sk->sk_filter &&
779 sk_filter(tfile->socket.sk, skb))
780 goto drop;
781
782 /* Limit the number of packets queued by dividing txq length with the
783 * number of queues.
784 */
785 if (skb_queue_len(&tfile->socket.sk->sk_receive_queue) * numqueues
786 >= dev->tx_queue_len)
787 goto drop;
788
789 if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
790 goto drop;
791
792 if (skb->sk) {
793 sock_tx_timestamp(skb->sk, &skb_shinfo(skb)->tx_flags);
794 sw_tx_timestamp(skb);
795 }
796
797 /* Orphan the skb - required as we might hang on to it
798 * for indefinite time.
799 */
800 skb_orphan(skb);
801
802 nf_reset(skb);
803
804 /* Enqueue packet */
805 skb_queue_tail(&tfile->socket.sk->sk_receive_queue, skb);
806
807 /* Notify and wake up reader process */
808 if (tfile->flags & TUN_FASYNC)
809 kill_fasync(&tfile->fasync, SIGIO, POLL_IN);
810 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
811
812 rcu_read_unlock();
813 return NETDEV_TX_OK;
814
815 drop:
816 dev->stats.tx_dropped++;
817 skb_tx_error(skb);
818 kfree_skb(skb);
819 rcu_read_unlock();
820 return NETDEV_TX_OK;
821 }
822
823 static void tun_net_mclist(struct net_device *dev)
824 {
825 /*
826 * This callback is supposed to deal with mc filter in
827 * _rx_ path and has nothing to do with the _tx_ path.
828 * In rx path we always accept everything userspace gives us.
829 */
830 }
831
832 #define MIN_MTU 68
833 #define MAX_MTU 65535
834
835 static int
836 tun_net_change_mtu(struct net_device *dev, int new_mtu)
837 {
838 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
839 return -EINVAL;
840 dev->mtu = new_mtu;
841 return 0;
842 }
843
844 static netdev_features_t tun_net_fix_features(struct net_device *dev,
845 netdev_features_t features)
846 {
847 struct tun_struct *tun = netdev_priv(dev);
848
849 return (features & tun->set_features) | (features & ~TUN_USER_FEATURES);
850 }
851 #ifdef CONFIG_NET_POLL_CONTROLLER
852 static void tun_poll_controller(struct net_device *dev)
853 {
854 /*
855 * Tun only receives frames when:
856 * 1) the char device endpoint gets data from user space
857 * 2) the tun socket gets a sendmsg call from user space
858 * Since both of those are synchronous operations, we are guaranteed
859 * never to have pending data when we poll for it
860 * so there is nothing to do here but return.
861 * We need this though so netpoll recognizes us as an interface that
862 * supports polling, which enables bridge devices in virt setups to
863 * still use netconsole
864 */
865 return;
866 }
867 #endif
868 static const struct net_device_ops tun_netdev_ops = {
869 .ndo_uninit = tun_net_uninit,
870 .ndo_open = tun_net_open,
871 .ndo_stop = tun_net_close,
872 .ndo_start_xmit = tun_net_xmit,
873 .ndo_change_mtu = tun_net_change_mtu,
874 .ndo_fix_features = tun_net_fix_features,
875 .ndo_select_queue = tun_select_queue,
876 #ifdef CONFIG_NET_POLL_CONTROLLER
877 .ndo_poll_controller = tun_poll_controller,
878 #endif
879 };
880
881 static const struct net_device_ops tap_netdev_ops = {
882 .ndo_uninit = tun_net_uninit,
883 .ndo_open = tun_net_open,
884 .ndo_stop = tun_net_close,
885 .ndo_start_xmit = tun_net_xmit,
886 .ndo_change_mtu = tun_net_change_mtu,
887 .ndo_fix_features = tun_net_fix_features,
888 .ndo_set_rx_mode = tun_net_mclist,
889 .ndo_set_mac_address = eth_mac_addr,
890 .ndo_validate_addr = eth_validate_addr,
891 .ndo_select_queue = tun_select_queue,
892 #ifdef CONFIG_NET_POLL_CONTROLLER
893 .ndo_poll_controller = tun_poll_controller,
894 #endif
895 };
896
897 static void tun_flow_init(struct tun_struct *tun)
898 {
899 int i;
900
901 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++)
902 INIT_HLIST_HEAD(&tun->flows[i]);
903
904 tun->ageing_time = TUN_FLOW_EXPIRE;
905 setup_timer(&tun->flow_gc_timer, tun_flow_cleanup, (unsigned long)tun);
906 mod_timer(&tun->flow_gc_timer,
907 round_jiffies_up(jiffies + tun->ageing_time));
908 }
909
910 static void tun_flow_uninit(struct tun_struct *tun)
911 {
912 del_timer_sync(&tun->flow_gc_timer);
913 tun_flow_flush(tun);
914 }
915
916 /* Initialize net device. */
917 static void tun_net_init(struct net_device *dev)
918 {
919 struct tun_struct *tun = netdev_priv(dev);
920
921 switch (tun->flags & TUN_TYPE_MASK) {
922 case TUN_TUN_DEV:
923 dev->netdev_ops = &tun_netdev_ops;
924
925 /* Point-to-Point TUN Device */
926 dev->hard_header_len = 0;
927 dev->addr_len = 0;
928 dev->mtu = 1500;
929
930 /* Zero header length */
931 dev->type = ARPHRD_NONE;
932 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
933 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
934 break;
935
936 case TUN_TAP_DEV:
937 dev->netdev_ops = &tap_netdev_ops;
938 /* Ethernet TAP Device */
939 ether_setup(dev);
940 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
941 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
942
943 eth_hw_addr_random(dev);
944
945 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
946 break;
947 }
948 }
949
950 /* Character device part */
951
952 /* Poll */
953 static unsigned int tun_chr_poll(struct file *file, poll_table *wait)
954 {
955 struct tun_file *tfile = file->private_data;
956 struct tun_struct *tun = __tun_get(tfile);
957 struct sock *sk;
958 unsigned int mask = 0;
959
960 if (!tun)
961 return POLLERR;
962
963 sk = tfile->socket.sk;
964
965 tun_debug(KERN_INFO, tun, "tun_chr_poll\n");
966
967 poll_wait(file, sk_sleep(sk), wait);
968
969 if (!skb_queue_empty(&sk->sk_receive_queue))
970 mask |= POLLIN | POLLRDNORM;
971
972 if (sock_writeable(sk) ||
973 (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
974 sock_writeable(sk)))
975 mask |= POLLOUT | POLLWRNORM;
976
977 if (tun->dev->reg_state != NETREG_REGISTERED)
978 mask = POLLERR;
979
980 tun_put(tun);
981 return mask;
982 }
983
984 /* prepad is the amount to reserve at front. len is length after that.
985 * linear is a hint as to how much to copy (usually headers). */
986 static struct sk_buff *tun_alloc_skb(struct tun_file *tfile,
987 size_t prepad, size_t len,
988 size_t linear, int noblock)
989 {
990 struct sock *sk = tfile->socket.sk;
991 struct sk_buff *skb;
992 int err;
993
994 /* Under a page? Don't bother with paged skb. */
995 if (prepad + len < PAGE_SIZE || !linear)
996 linear = len;
997
998 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
999 &err, 0);
1000 if (!skb)
1001 return ERR_PTR(err);
1002
1003 skb_reserve(skb, prepad);
1004 skb_put(skb, linear);
1005 skb->data_len = len - linear;
1006 skb->len += len - linear;
1007
1008 return skb;
1009 }
1010
1011 /* Get packet from user space buffer */
1012 static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
1013 void *msg_control, const struct iovec *iv,
1014 size_t total_len, size_t count, int noblock)
1015 {
1016 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
1017 struct sk_buff *skb;
1018 size_t len = total_len, align = NET_SKB_PAD, linear;
1019 struct virtio_net_hdr gso = { 0 };
1020 int good_linear;
1021 int offset = 0;
1022 int copylen;
1023 bool zerocopy = false;
1024 int err;
1025 u32 rxhash;
1026
1027 if (!(tun->flags & TUN_NO_PI)) {
1028 if (len < sizeof(pi))
1029 return -EINVAL;
1030 len -= sizeof(pi);
1031
1032 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
1033 return -EFAULT;
1034 offset += sizeof(pi);
1035 }
1036
1037 if (tun->flags & TUN_VNET_HDR) {
1038 if (len < tun->vnet_hdr_sz)
1039 return -EINVAL;
1040 len -= tun->vnet_hdr_sz;
1041
1042 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
1043 return -EFAULT;
1044
1045 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
1046 gso.csum_start + gso.csum_offset + 2 > gso.hdr_len)
1047 gso.hdr_len = gso.csum_start + gso.csum_offset + 2;
1048
1049 if (gso.hdr_len > len)
1050 return -EINVAL;
1051 offset += tun->vnet_hdr_sz;
1052 }
1053
1054 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
1055 align += NET_IP_ALIGN;
1056 if (unlikely(len < ETH_HLEN ||
1057 (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
1058 return -EINVAL;
1059 }
1060
1061 good_linear = SKB_MAX_HEAD(align);
1062
1063 if (msg_control) {
1064 /* There are 256 bytes to be copied in skb, so there is
1065 * enough room for skb expand head in case it is used.
1066 * The rest of the buffer is mapped from userspace.
1067 */
1068 copylen = gso.hdr_len ? gso.hdr_len : GOODCOPY_LEN;
1069 if (copylen > good_linear)
1070 copylen = good_linear;
1071 linear = copylen;
1072 if (iov_pages(iv, offset + copylen, count) <= MAX_SKB_FRAGS)
1073 zerocopy = true;
1074 }
1075
1076 if (!zerocopy) {
1077 copylen = len;
1078 if (gso.hdr_len > good_linear)
1079 linear = good_linear;
1080 else
1081 linear = gso.hdr_len;
1082 }
1083
1084 skb = tun_alloc_skb(tfile, align, copylen, linear, noblock);
1085 if (IS_ERR(skb)) {
1086 if (PTR_ERR(skb) != -EAGAIN)
1087 tun->dev->stats.rx_dropped++;
1088 return PTR_ERR(skb);
1089 }
1090
1091 if (zerocopy)
1092 err = zerocopy_sg_from_iovec(skb, iv, offset, count);
1093 else {
1094 err = skb_copy_datagram_from_iovec(skb, 0, iv, offset, len);
1095 if (!err && msg_control) {
1096 struct ubuf_info *uarg = msg_control;
1097 uarg->callback(uarg, false);
1098 }
1099 }
1100
1101 if (err) {
1102 tun->dev->stats.rx_dropped++;
1103 kfree_skb(skb);
1104 return -EFAULT;
1105 }
1106
1107 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
1108 if (!skb_partial_csum_set(skb, gso.csum_start,
1109 gso.csum_offset)) {
1110 tun->dev->stats.rx_frame_errors++;
1111 kfree_skb(skb);
1112 return -EINVAL;
1113 }
1114 }
1115
1116 switch (tun->flags & TUN_TYPE_MASK) {
1117 case TUN_TUN_DEV:
1118 if (tun->flags & TUN_NO_PI) {
1119 switch (skb->data[0] & 0xf0) {
1120 case 0x40:
1121 pi.proto = htons(ETH_P_IP);
1122 break;
1123 case 0x60:
1124 pi.proto = htons(ETH_P_IPV6);
1125 break;
1126 default:
1127 tun->dev->stats.rx_dropped++;
1128 kfree_skb(skb);
1129 return -EINVAL;
1130 }
1131 }
1132
1133 skb_reset_mac_header(skb);
1134 skb->protocol = pi.proto;
1135 skb->dev = tun->dev;
1136 break;
1137 case TUN_TAP_DEV:
1138 skb->protocol = eth_type_trans(skb, tun->dev);
1139 break;
1140 }
1141
1142 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
1143 pr_debug("GSO!\n");
1144 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
1145 case VIRTIO_NET_HDR_GSO_TCPV4:
1146 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
1147 break;
1148 case VIRTIO_NET_HDR_GSO_TCPV6:
1149 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
1150 break;
1151 case VIRTIO_NET_HDR_GSO_UDP:
1152 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
1153 break;
1154 default:
1155 tun->dev->stats.rx_frame_errors++;
1156 kfree_skb(skb);
1157 return -EINVAL;
1158 }
1159
1160 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
1161 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
1162
1163 skb_shinfo(skb)->gso_size = gso.gso_size;
1164 if (skb_shinfo(skb)->gso_size == 0) {
1165 tun->dev->stats.rx_frame_errors++;
1166 kfree_skb(skb);
1167 return -EINVAL;
1168 }
1169
1170 /* Header must be checked, and gso_segs computed. */
1171 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
1172 skb_shinfo(skb)->gso_segs = 0;
1173 }
1174
1175 /* copy skb_ubuf_info for callback when skb has no error */
1176 if (zerocopy) {
1177 skb_shinfo(skb)->destructor_arg = msg_control;
1178 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1179 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
1180 }
1181
1182 skb_reset_network_header(skb);
1183 skb_probe_transport_header(skb, 0);
1184
1185 rxhash = skb_get_hash(skb);
1186 netif_rx_ni(skb);
1187
1188 tun->dev->stats.rx_packets++;
1189 tun->dev->stats.rx_bytes += len;
1190
1191 tun_flow_update(tun, rxhash, tfile);
1192 return total_len;
1193 }
1194
1195 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
1196 unsigned long count, loff_t pos)
1197 {
1198 struct file *file = iocb->ki_filp;
1199 struct tun_struct *tun = tun_get(file);
1200 struct tun_file *tfile = file->private_data;
1201 ssize_t result;
1202
1203 if (!tun)
1204 return -EBADFD;
1205
1206 tun_debug(KERN_INFO, tun, "tun_chr_write %ld\n", count);
1207
1208 result = tun_get_user(tun, tfile, NULL, iv, iov_length(iv, count),
1209 count, file->f_flags & O_NONBLOCK);
1210
1211 tun_put(tun);
1212 return result;
1213 }
1214
1215 /* Put packet to the user space buffer */
1216 static ssize_t tun_put_user(struct tun_struct *tun,
1217 struct tun_file *tfile,
1218 struct sk_buff *skb,
1219 const struct iovec *iv, int len)
1220 {
1221 struct tun_pi pi = { 0, skb->protocol };
1222 ssize_t total = 0;
1223 int vlan_offset = 0, copied;
1224
1225 if (!(tun->flags & TUN_NO_PI)) {
1226 if ((len -= sizeof(pi)) < 0)
1227 return -EINVAL;
1228
1229 if (len < skb->len) {
1230 /* Packet will be striped */
1231 pi.flags |= TUN_PKT_STRIP;
1232 }
1233
1234 if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi)))
1235 return -EFAULT;
1236 total += sizeof(pi);
1237 }
1238
1239 if (tun->flags & TUN_VNET_HDR) {
1240 struct virtio_net_hdr gso = { 0 }; /* no info leak */
1241 if ((len -= tun->vnet_hdr_sz) < 0)
1242 return -EINVAL;
1243
1244 if (skb_is_gso(skb)) {
1245 struct skb_shared_info *sinfo = skb_shinfo(skb);
1246
1247 /* This is a hint as to how much should be linear. */
1248 gso.hdr_len = skb_headlen(skb);
1249 gso.gso_size = sinfo->gso_size;
1250 if (sinfo->gso_type & SKB_GSO_TCPV4)
1251 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
1252 else if (sinfo->gso_type & SKB_GSO_TCPV6)
1253 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
1254 else if (sinfo->gso_type & SKB_GSO_UDP)
1255 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
1256 else {
1257 pr_err("unexpected GSO type: "
1258 "0x%x, gso_size %d, hdr_len %d\n",
1259 sinfo->gso_type, gso.gso_size,
1260 gso.hdr_len);
1261 print_hex_dump(KERN_ERR, "tun: ",
1262 DUMP_PREFIX_NONE,
1263 16, 1, skb->head,
1264 min((int)gso.hdr_len, 64), true);
1265 WARN_ON_ONCE(1);
1266 return -EINVAL;
1267 }
1268 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
1269 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
1270 } else
1271 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
1272
1273 if (skb->ip_summed == CHECKSUM_PARTIAL) {
1274 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
1275 gso.csum_start = skb_checksum_start_offset(skb);
1276 gso.csum_offset = skb->csum_offset;
1277 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
1278 gso.flags = VIRTIO_NET_HDR_F_DATA_VALID;
1279 } /* else everything is zero */
1280
1281 if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
1282 sizeof(gso))))
1283 return -EFAULT;
1284 total += tun->vnet_hdr_sz;
1285 }
1286
1287 copied = total;
1288 total += skb->len;
1289 if (!vlan_tx_tag_present(skb)) {
1290 len = min_t(int, skb->len, len);
1291 } else {
1292 int copy, ret;
1293 struct {
1294 __be16 h_vlan_proto;
1295 __be16 h_vlan_TCI;
1296 } veth;
1297
1298 veth.h_vlan_proto = skb->vlan_proto;
1299 veth.h_vlan_TCI = htons(vlan_tx_tag_get(skb));
1300
1301 vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);
1302 len = min_t(int, skb->len + VLAN_HLEN, len);
1303 total += VLAN_HLEN;
1304
1305 copy = min_t(int, vlan_offset, len);
1306 ret = skb_copy_datagram_const_iovec(skb, 0, iv, copied, copy);
1307 len -= copy;
1308 copied += copy;
1309 if (ret || !len)
1310 goto done;
1311
1312 copy = min_t(int, sizeof(veth), len);
1313 ret = memcpy_toiovecend(iv, (void *)&veth, copied, copy);
1314 len -= copy;
1315 copied += copy;
1316 if (ret || !len)
1317 goto done;
1318 }
1319
1320 skb_copy_datagram_const_iovec(skb, vlan_offset, iv, copied, len);
1321
1322 done:
1323 tun->dev->stats.tx_packets++;
1324 tun->dev->stats.tx_bytes += len;
1325
1326 return total;
1327 }
1328
1329 static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
1330 const struct iovec *iv, ssize_t len, int noblock)
1331 {
1332 struct sk_buff *skb;
1333 ssize_t ret = 0;
1334 int peeked, err, off = 0;
1335
1336 tun_debug(KERN_INFO, tun, "tun_do_read\n");
1337
1338 if (!len)
1339 return ret;
1340
1341 if (tun->dev->reg_state != NETREG_REGISTERED)
1342 return -EIO;
1343
1344 /* Read frames from queue */
1345 skb = __skb_recv_datagram(tfile->socket.sk, noblock ? MSG_DONTWAIT : 0,
1346 &peeked, &off, &err);
1347 if (skb) {
1348 ret = tun_put_user(tun, tfile, skb, iv, len);
1349 kfree_skb(skb);
1350 } else
1351 ret = err;
1352
1353 return ret;
1354 }
1355
1356 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
1357 unsigned long count, loff_t pos)
1358 {
1359 struct file *file = iocb->ki_filp;
1360 struct tun_file *tfile = file->private_data;
1361 struct tun_struct *tun = __tun_get(tfile);
1362 ssize_t len, ret;
1363
1364 if (!tun)
1365 return -EBADFD;
1366 len = iov_length(iv, count);
1367 if (len < 0) {
1368 ret = -EINVAL;
1369 goto out;
1370 }
1371
1372 ret = tun_do_read(tun, tfile, iv, len,
1373 file->f_flags & O_NONBLOCK);
1374 ret = min_t(ssize_t, ret, len);
1375 if (ret > 0)
1376 iocb->ki_pos = ret;
1377 out:
1378 tun_put(tun);
1379 return ret;
1380 }
1381
1382 static void tun_free_netdev(struct net_device *dev)
1383 {
1384 struct tun_struct *tun = netdev_priv(dev);
1385
1386 BUG_ON(!(list_empty(&tun->disabled)));
1387 tun_flow_uninit(tun);
1388 security_tun_dev_free_security(tun->security);
1389 free_netdev(dev);
1390 }
1391
1392 static void tun_setup(struct net_device *dev)
1393 {
1394 struct tun_struct *tun = netdev_priv(dev);
1395
1396 tun->owner = INVALID_UID;
1397 tun->group = INVALID_GID;
1398
1399 dev->ethtool_ops = &tun_ethtool_ops;
1400 dev->destructor = tun_free_netdev;
1401 }
1402
1403 /* Trivial set of netlink ops to allow deleting tun or tap
1404 * device with netlink.
1405 */
1406 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
1407 {
1408 return -EINVAL;
1409 }
1410
1411 static struct rtnl_link_ops tun_link_ops __read_mostly = {
1412 .kind = DRV_NAME,
1413 .priv_size = sizeof(struct tun_struct),
1414 .setup = tun_setup,
1415 .validate = tun_validate,
1416 };
1417
1418 static void tun_sock_write_space(struct sock *sk)
1419 {
1420 struct tun_file *tfile;
1421 wait_queue_head_t *wqueue;
1422
1423 if (!sock_writeable(sk))
1424 return;
1425
1426 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
1427 return;
1428
1429 wqueue = sk_sleep(sk);
1430 if (wqueue && waitqueue_active(wqueue))
1431 wake_up_interruptible_sync_poll(wqueue, POLLOUT |
1432 POLLWRNORM | POLLWRBAND);
1433
1434 tfile = container_of(sk, struct tun_file, sk);
1435 kill_fasync(&tfile->fasync, SIGIO, POLL_OUT);
1436 }
1437
1438 static int tun_sendmsg(struct kiocb *iocb, struct socket *sock,
1439 struct msghdr *m, size_t total_len)
1440 {
1441 int ret;
1442 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1443 struct tun_struct *tun = __tun_get(tfile);
1444
1445 if (!tun)
1446 return -EBADFD;
1447 ret = tun_get_user(tun, tfile, m->msg_control, m->msg_iov, total_len,
1448 m->msg_iovlen, m->msg_flags & MSG_DONTWAIT);
1449 tun_put(tun);
1450 return ret;
1451 }
1452
1453 static int tun_recvmsg(struct kiocb *iocb, struct socket *sock,
1454 struct msghdr *m, size_t total_len,
1455 int flags)
1456 {
1457 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1458 struct tun_struct *tun = __tun_get(tfile);
1459 int ret;
1460
1461 if (!tun)
1462 return -EBADFD;
1463
1464 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC|MSG_ERRQUEUE)) {
1465 ret = -EINVAL;
1466 goto out;
1467 }
1468 if (flags & MSG_ERRQUEUE) {
1469 ret = sock_recv_errqueue(sock->sk, m, total_len,
1470 SOL_PACKET, TUN_TX_TIMESTAMP);
1471 goto out;
1472 }
1473 ret = tun_do_read(tun, tfile, m->msg_iov, total_len,
1474 flags & MSG_DONTWAIT);
1475 if (ret > total_len) {
1476 m->msg_flags |= MSG_TRUNC;
1477 ret = flags & MSG_TRUNC ? ret : total_len;
1478 }
1479 out:
1480 tun_put(tun);
1481 return ret;
1482 }
1483
1484 static int tun_release(struct socket *sock)
1485 {
1486 if (sock->sk)
1487 sock_put(sock->sk);
1488 return 0;
1489 }
1490
1491 /* Ops structure to mimic raw sockets with tun */
1492 static const struct proto_ops tun_socket_ops = {
1493 .sendmsg = tun_sendmsg,
1494 .recvmsg = tun_recvmsg,
1495 .release = tun_release,
1496 };
1497
1498 static struct proto tun_proto = {
1499 .name = "tun",
1500 .owner = THIS_MODULE,
1501 .obj_size = sizeof(struct tun_file),
1502 };
1503
1504 static int tun_flags(struct tun_struct *tun)
1505 {
1506 int flags = 0;
1507
1508 if (tun->flags & TUN_TUN_DEV)
1509 flags |= IFF_TUN;
1510 else
1511 flags |= IFF_TAP;
1512
1513 if (tun->flags & TUN_NO_PI)
1514 flags |= IFF_NO_PI;
1515
1516 /* This flag has no real effect. We track the value for backwards
1517 * compatibility.
1518 */
1519 if (tun->flags & TUN_ONE_QUEUE)
1520 flags |= IFF_ONE_QUEUE;
1521
1522 if (tun->flags & TUN_VNET_HDR)
1523 flags |= IFF_VNET_HDR;
1524
1525 if (tun->flags & TUN_TAP_MQ)
1526 flags |= IFF_MULTI_QUEUE;
1527
1528 if (tun->flags & TUN_PERSIST)
1529 flags |= IFF_PERSIST;
1530
1531 return flags;
1532 }
1533
1534 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
1535 char *buf)
1536 {
1537 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1538 return sprintf(buf, "0x%x\n", tun_flags(tun));
1539 }
1540
1541 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
1542 char *buf)
1543 {
1544 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1545 return uid_valid(tun->owner)?
1546 sprintf(buf, "%u\n",
1547 from_kuid_munged(current_user_ns(), tun->owner)):
1548 sprintf(buf, "-1\n");
1549 }
1550
1551 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
1552 char *buf)
1553 {
1554 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1555 return gid_valid(tun->group) ?
1556 sprintf(buf, "%u\n",
1557 from_kgid_munged(current_user_ns(), tun->group)):
1558 sprintf(buf, "-1\n");
1559 }
1560
1561 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
1562 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
1563 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
1564
1565 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
1566 {
1567 struct tun_struct *tun;
1568 struct tun_file *tfile = file->private_data;
1569 struct net_device *dev;
1570 int err;
1571
1572 if (tfile->detached)
1573 return -EINVAL;
1574
1575 dev = __dev_get_by_name(net, ifr->ifr_name);
1576 if (dev) {
1577 if (ifr->ifr_flags & IFF_TUN_EXCL)
1578 return -EBUSY;
1579 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
1580 tun = netdev_priv(dev);
1581 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
1582 tun = netdev_priv(dev);
1583 else
1584 return -EINVAL;
1585
1586 if (!!(ifr->ifr_flags & IFF_MULTI_QUEUE) !=
1587 !!(tun->flags & TUN_TAP_MQ))
1588 return -EINVAL;
1589
1590 if (tun_not_capable(tun))
1591 return -EPERM;
1592 err = security_tun_dev_open(tun->security);
1593 if (err < 0)
1594 return err;
1595
1596 err = tun_attach(tun, file, ifr->ifr_flags & IFF_NOFILTER);
1597 if (err < 0)
1598 return err;
1599
1600 if (tun->flags & TUN_TAP_MQ &&
1601 (tun->numqueues + tun->numdisabled > 1)) {
1602 /* One or more queue has already been attached, no need
1603 * to initialize the device again.
1604 */
1605 return 0;
1606 }
1607 }
1608 else {
1609 char *name;
1610 unsigned long flags = 0;
1611 int queues = ifr->ifr_flags & IFF_MULTI_QUEUE ?
1612 MAX_TAP_QUEUES : 1;
1613
1614 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1615 return -EPERM;
1616 err = security_tun_dev_create();
1617 if (err < 0)
1618 return err;
1619
1620 /* Set dev type */
1621 if (ifr->ifr_flags & IFF_TUN) {
1622 /* TUN device */
1623 flags |= TUN_TUN_DEV;
1624 name = "tun%d";
1625 } else if (ifr->ifr_flags & IFF_TAP) {
1626 /* TAP device */
1627 flags |= TUN_TAP_DEV;
1628 name = "tap%d";
1629 } else
1630 return -EINVAL;
1631
1632 if (*ifr->ifr_name)
1633 name = ifr->ifr_name;
1634
1635 dev = alloc_netdev_mqs(sizeof(struct tun_struct), name,
1636 tun_setup, queues, queues);
1637
1638 if (!dev)
1639 return -ENOMEM;
1640
1641 dev_net_set(dev, net);
1642 dev->rtnl_link_ops = &tun_link_ops;
1643 dev->ifindex = tfile->ifindex;
1644
1645 tun = netdev_priv(dev);
1646 tun->dev = dev;
1647 tun->flags = flags;
1648 tun->txflt.count = 0;
1649 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
1650
1651 tun->filter_attached = false;
1652 tun->sndbuf = tfile->socket.sk->sk_sndbuf;
1653
1654 spin_lock_init(&tun->lock);
1655
1656 err = security_tun_dev_alloc_security(&tun->security);
1657 if (err < 0)
1658 goto err_free_dev;
1659
1660 tun_net_init(dev);
1661 tun_flow_init(tun);
1662
1663 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
1664 TUN_USER_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
1665 NETIF_F_HW_VLAN_STAG_TX;
1666 dev->features = dev->hw_features;
1667 dev->vlan_features = dev->features &
1668 ~(NETIF_F_HW_VLAN_CTAG_TX |
1669 NETIF_F_HW_VLAN_STAG_TX);
1670
1671 INIT_LIST_HEAD(&tun->disabled);
1672 err = tun_attach(tun, file, false);
1673 if (err < 0)
1674 goto err_free_flow;
1675
1676 err = register_netdevice(tun->dev);
1677 if (err < 0)
1678 goto err_detach;
1679
1680 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
1681 device_create_file(&tun->dev->dev, &dev_attr_owner) ||
1682 device_create_file(&tun->dev->dev, &dev_attr_group))
1683 pr_err("Failed to create tun sysfs files\n");
1684 }
1685
1686 netif_carrier_on(tun->dev);
1687
1688 tun_debug(KERN_INFO, tun, "tun_set_iff\n");
1689
1690 if (ifr->ifr_flags & IFF_NO_PI)
1691 tun->flags |= TUN_NO_PI;
1692 else
1693 tun->flags &= ~TUN_NO_PI;
1694
1695 /* This flag has no real effect. We track the value for backwards
1696 * compatibility.
1697 */
1698 if (ifr->ifr_flags & IFF_ONE_QUEUE)
1699 tun->flags |= TUN_ONE_QUEUE;
1700 else
1701 tun->flags &= ~TUN_ONE_QUEUE;
1702
1703 if (ifr->ifr_flags & IFF_VNET_HDR)
1704 tun->flags |= TUN_VNET_HDR;
1705 else
1706 tun->flags &= ~TUN_VNET_HDR;
1707
1708 if (ifr->ifr_flags & IFF_MULTI_QUEUE)
1709 tun->flags |= TUN_TAP_MQ;
1710 else
1711 tun->flags &= ~TUN_TAP_MQ;
1712
1713 /* Make sure persistent devices do not get stuck in
1714 * xoff state.
1715 */
1716 if (netif_running(tun->dev))
1717 netif_tx_wake_all_queues(tun->dev);
1718
1719 strcpy(ifr->ifr_name, tun->dev->name);
1720 return 0;
1721
1722 err_detach:
1723 tun_detach_all(dev);
1724 err_free_flow:
1725 tun_flow_uninit(tun);
1726 security_tun_dev_free_security(tun->security);
1727 err_free_dev:
1728 free_netdev(dev);
1729 return err;
1730 }
1731
1732 static void tun_get_iff(struct net *net, struct tun_struct *tun,
1733 struct ifreq *ifr)
1734 {
1735 tun_debug(KERN_INFO, tun, "tun_get_iff\n");
1736
1737 strcpy(ifr->ifr_name, tun->dev->name);
1738
1739 ifr->ifr_flags = tun_flags(tun);
1740
1741 }
1742
1743 /* This is like a cut-down ethtool ops, except done via tun fd so no
1744 * privs required. */
1745 static int set_offload(struct tun_struct *tun, unsigned long arg)
1746 {
1747 netdev_features_t features = 0;
1748
1749 if (arg & TUN_F_CSUM) {
1750 features |= NETIF_F_HW_CSUM;
1751 arg &= ~TUN_F_CSUM;
1752
1753 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1754 if (arg & TUN_F_TSO_ECN) {
1755 features |= NETIF_F_TSO_ECN;
1756 arg &= ~TUN_F_TSO_ECN;
1757 }
1758 if (arg & TUN_F_TSO4)
1759 features |= NETIF_F_TSO;
1760 if (arg & TUN_F_TSO6)
1761 features |= NETIF_F_TSO6;
1762 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1763 }
1764
1765 if (arg & TUN_F_UFO) {
1766 features |= NETIF_F_UFO;
1767 arg &= ~TUN_F_UFO;
1768 }
1769 }
1770
1771 /* This gives the user a way to test for new features in future by
1772 * trying to set them. */
1773 if (arg)
1774 return -EINVAL;
1775
1776 tun->set_features = features;
1777 netdev_update_features(tun->dev);
1778
1779 return 0;
1780 }
1781
1782 static void tun_detach_filter(struct tun_struct *tun, int n)
1783 {
1784 int i;
1785 struct tun_file *tfile;
1786
1787 for (i = 0; i < n; i++) {
1788 tfile = rtnl_dereference(tun->tfiles[i]);
1789 sk_detach_filter(tfile->socket.sk);
1790 }
1791
1792 tun->filter_attached = false;
1793 }
1794
1795 static int tun_attach_filter(struct tun_struct *tun)
1796 {
1797 int i, ret = 0;
1798 struct tun_file *tfile;
1799
1800 for (i = 0; i < tun->numqueues; i++) {
1801 tfile = rtnl_dereference(tun->tfiles[i]);
1802 ret = sk_attach_filter(&tun->fprog, tfile->socket.sk);
1803 if (ret) {
1804 tun_detach_filter(tun, i);
1805 return ret;
1806 }
1807 }
1808
1809 tun->filter_attached = true;
1810 return ret;
1811 }
1812
1813 static void tun_set_sndbuf(struct tun_struct *tun)
1814 {
1815 struct tun_file *tfile;
1816 int i;
1817
1818 for (i = 0; i < tun->numqueues; i++) {
1819 tfile = rtnl_dereference(tun->tfiles[i]);
1820 tfile->socket.sk->sk_sndbuf = tun->sndbuf;
1821 }
1822 }
1823
1824 static int tun_set_queue(struct file *file, struct ifreq *ifr)
1825 {
1826 struct tun_file *tfile = file->private_data;
1827 struct tun_struct *tun;
1828 int ret = 0;
1829
1830 rtnl_lock();
1831
1832 if (ifr->ifr_flags & IFF_ATTACH_QUEUE) {
1833 tun = tfile->detached;
1834 if (!tun) {
1835 ret = -EINVAL;
1836 goto unlock;
1837 }
1838 ret = security_tun_dev_attach_queue(tun->security);
1839 if (ret < 0)
1840 goto unlock;
1841 ret = tun_attach(tun, file, false);
1842 } else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
1843 tun = rtnl_dereference(tfile->tun);
1844 if (!tun || !(tun->flags & TUN_TAP_MQ) || tfile->detached)
1845 ret = -EINVAL;
1846 else
1847 __tun_detach(tfile, false);
1848 } else
1849 ret = -EINVAL;
1850
1851 unlock:
1852 rtnl_unlock();
1853 return ret;
1854 }
1855
1856 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
1857 unsigned long arg, int ifreq_len)
1858 {
1859 struct tun_file *tfile = file->private_data;
1860 struct tun_struct *tun;
1861 void __user* argp = (void __user*)arg;
1862 struct ifreq ifr;
1863 kuid_t owner;
1864 kgid_t group;
1865 int sndbuf;
1866 int vnet_hdr_sz;
1867 unsigned int ifindex;
1868 int ret;
1869
1870 if (cmd == TUNSETIFF || cmd == TUNSETQUEUE || _IOC_TYPE(cmd) == 0x89) {
1871 if (copy_from_user(&ifr, argp, ifreq_len))
1872 return -EFAULT;
1873 } else {
1874 memset(&ifr, 0, sizeof(ifr));
1875 }
1876 if (cmd == TUNGETFEATURES) {
1877 /* Currently this just means: "what IFF flags are valid?".
1878 * This is needed because we never checked for invalid flags on
1879 * TUNSETIFF. */
1880 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
1881 IFF_VNET_HDR | IFF_MULTI_QUEUE,
1882 (unsigned int __user*)argp);
1883 } else if (cmd == TUNSETQUEUE)
1884 return tun_set_queue(file, &ifr);
1885
1886 ret = 0;
1887 rtnl_lock();
1888
1889 tun = __tun_get(tfile);
1890 if (cmd == TUNSETIFF && !tun) {
1891 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1892
1893 ret = tun_set_iff(tfile->net, file, &ifr);
1894
1895 if (ret)
1896 goto unlock;
1897
1898 if (copy_to_user(argp, &ifr, ifreq_len))
1899 ret = -EFAULT;
1900 goto unlock;
1901 }
1902 if (cmd == TUNSETIFINDEX) {
1903 ret = -EPERM;
1904 if (tun)
1905 goto unlock;
1906
1907 ret = -EFAULT;
1908 if (copy_from_user(&ifindex, argp, sizeof(ifindex)))
1909 goto unlock;
1910
1911 ret = 0;
1912 tfile->ifindex = ifindex;
1913 goto unlock;
1914 }
1915
1916 ret = -EBADFD;
1917 if (!tun)
1918 goto unlock;
1919
1920 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %u\n", cmd);
1921
1922 ret = 0;
1923 switch (cmd) {
1924 case TUNGETIFF:
1925 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1926
1927 if (tfile->detached)
1928 ifr.ifr_flags |= IFF_DETACH_QUEUE;
1929 if (!tfile->socket.sk->sk_filter)
1930 ifr.ifr_flags |= IFF_NOFILTER;
1931
1932 if (copy_to_user(argp, &ifr, ifreq_len))
1933 ret = -EFAULT;
1934 break;
1935
1936 case TUNSETNOCSUM:
1937 /* Disable/Enable checksum */
1938
1939 /* [unimplemented] */
1940 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n",
1941 arg ? "disabled" : "enabled");
1942 break;
1943
1944 case TUNSETPERSIST:
1945 /* Disable/Enable persist mode. Keep an extra reference to the
1946 * module to prevent the module being unprobed.
1947 */
1948 if (arg && !(tun->flags & TUN_PERSIST)) {
1949 tun->flags |= TUN_PERSIST;
1950 __module_get(THIS_MODULE);
1951 }
1952 if (!arg && (tun->flags & TUN_PERSIST)) {
1953 tun->flags &= ~TUN_PERSIST;
1954 module_put(THIS_MODULE);
1955 }
1956
1957 tun_debug(KERN_INFO, tun, "persist %s\n",
1958 arg ? "enabled" : "disabled");
1959 break;
1960
1961 case TUNSETOWNER:
1962 /* Set owner of the device */
1963 owner = make_kuid(current_user_ns(), arg);
1964 if (!uid_valid(owner)) {
1965 ret = -EINVAL;
1966 break;
1967 }
1968 tun->owner = owner;
1969 tun_debug(KERN_INFO, tun, "owner set to %u\n",
1970 from_kuid(&init_user_ns, tun->owner));
1971 break;
1972
1973 case TUNSETGROUP:
1974 /* Set group of the device */
1975 group = make_kgid(current_user_ns(), arg);
1976 if (!gid_valid(group)) {
1977 ret = -EINVAL;
1978 break;
1979 }
1980 tun->group = group;
1981 tun_debug(KERN_INFO, tun, "group set to %u\n",
1982 from_kgid(&init_user_ns, tun->group));
1983 break;
1984
1985 case TUNSETLINK:
1986 /* Only allow setting the type when the interface is down */
1987 if (tun->dev->flags & IFF_UP) {
1988 tun_debug(KERN_INFO, tun,
1989 "Linktype set failed because interface is up\n");
1990 ret = -EBUSY;
1991 } else {
1992 tun->dev->type = (int) arg;
1993 tun_debug(KERN_INFO, tun, "linktype set to %d\n",
1994 tun->dev->type);
1995 ret = 0;
1996 }
1997 break;
1998
1999 #ifdef TUN_DEBUG
2000 case TUNSETDEBUG:
2001 tun->debug = arg;
2002 break;
2003 #endif
2004 case TUNSETOFFLOAD:
2005 ret = set_offload(tun, arg);
2006 break;
2007
2008 case TUNSETTXFILTER:
2009 /* Can be set only for TAPs */
2010 ret = -EINVAL;
2011 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
2012 break;
2013 ret = update_filter(&tun->txflt, (void __user *)arg);
2014 break;
2015
2016 case SIOCGIFHWADDR:
2017 /* Get hw address */
2018 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
2019 ifr.ifr_hwaddr.sa_family = tun->dev->type;
2020 if (copy_to_user(argp, &ifr, ifreq_len))
2021 ret = -EFAULT;
2022 break;
2023
2024 case SIOCSIFHWADDR:
2025 /* Set hw address */
2026 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
2027 ifr.ifr_hwaddr.sa_data);
2028
2029 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
2030 break;
2031
2032 case TUNGETSNDBUF:
2033 sndbuf = tfile->socket.sk->sk_sndbuf;
2034 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
2035 ret = -EFAULT;
2036 break;
2037
2038 case TUNSETSNDBUF:
2039 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
2040 ret = -EFAULT;
2041 break;
2042 }
2043
2044 tun->sndbuf = sndbuf;
2045 tun_set_sndbuf(tun);
2046 break;
2047
2048 case TUNGETVNETHDRSZ:
2049 vnet_hdr_sz = tun->vnet_hdr_sz;
2050 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
2051 ret = -EFAULT;
2052 break;
2053
2054 case TUNSETVNETHDRSZ:
2055 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
2056 ret = -EFAULT;
2057 break;
2058 }
2059 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
2060 ret = -EINVAL;
2061 break;
2062 }
2063
2064 tun->vnet_hdr_sz = vnet_hdr_sz;
2065 break;
2066
2067 case TUNATTACHFILTER:
2068 /* Can be set only for TAPs */
2069 ret = -EINVAL;
2070 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
2071 break;
2072 ret = -EFAULT;
2073 if (copy_from_user(&tun->fprog, argp, sizeof(tun->fprog)))
2074 break;
2075
2076 ret = tun_attach_filter(tun);
2077 break;
2078
2079 case TUNDETACHFILTER:
2080 /* Can be set only for TAPs */
2081 ret = -EINVAL;
2082 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
2083 break;
2084 ret = 0;
2085 tun_detach_filter(tun, tun->numqueues);
2086 break;
2087
2088 case TUNGETFILTER:
2089 ret = -EINVAL;
2090 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
2091 break;
2092 ret = -EFAULT;
2093 if (copy_to_user(argp, &tun->fprog, sizeof(tun->fprog)))
2094 break;
2095 ret = 0;
2096 break;
2097
2098 default:
2099 ret = -EINVAL;
2100 break;
2101 }
2102
2103 unlock:
2104 rtnl_unlock();
2105 if (tun)
2106 tun_put(tun);
2107 return ret;
2108 }
2109
2110 static long tun_chr_ioctl(struct file *file,
2111 unsigned int cmd, unsigned long arg)
2112 {
2113 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
2114 }
2115
2116 #ifdef CONFIG_COMPAT
2117 static long tun_chr_compat_ioctl(struct file *file,
2118 unsigned int cmd, unsigned long arg)
2119 {
2120 switch (cmd) {
2121 case TUNSETIFF:
2122 case TUNGETIFF:
2123 case TUNSETTXFILTER:
2124 case TUNGETSNDBUF:
2125 case TUNSETSNDBUF:
2126 case SIOCGIFHWADDR:
2127 case SIOCSIFHWADDR:
2128 arg = (unsigned long)compat_ptr(arg);
2129 break;
2130 default:
2131 arg = (compat_ulong_t)arg;
2132 break;
2133 }
2134
2135 /*
2136 * compat_ifreq is shorter than ifreq, so we must not access beyond
2137 * the end of that structure. All fields that are used in this
2138 * driver are compatible though, we don't need to convert the
2139 * contents.
2140 */
2141 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
2142 }
2143 #endif /* CONFIG_COMPAT */
2144
2145 static int tun_chr_fasync(int fd, struct file *file, int on)
2146 {
2147 struct tun_file *tfile = file->private_data;
2148 int ret;
2149
2150 if ((ret = fasync_helper(fd, file, on, &tfile->fasync)) < 0)
2151 goto out;
2152
2153 if (on) {
2154 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
2155 if (ret)
2156 goto out;
2157 tfile->flags |= TUN_FASYNC;
2158 } else
2159 tfile->flags &= ~TUN_FASYNC;
2160 ret = 0;
2161 out:
2162 return ret;
2163 }
2164
2165 static int tun_chr_open(struct inode *inode, struct file * file)
2166 {
2167 struct tun_file *tfile;
2168
2169 DBG1(KERN_INFO, "tunX: tun_chr_open\n");
2170
2171 tfile = (struct tun_file *)sk_alloc(&init_net, AF_UNSPEC, GFP_KERNEL,
2172 &tun_proto);
2173 if (!tfile)
2174 return -ENOMEM;
2175 RCU_INIT_POINTER(tfile->tun, NULL);
2176 tfile->net = get_net(current->nsproxy->net_ns);
2177 tfile->flags = 0;
2178 tfile->ifindex = 0;
2179
2180 init_waitqueue_head(&tfile->wq.wait);
2181 RCU_INIT_POINTER(tfile->socket.wq, &tfile->wq);
2182
2183 tfile->socket.file = file;
2184 tfile->socket.ops = &tun_socket_ops;
2185
2186 sock_init_data(&tfile->socket, &tfile->sk);
2187 sk_change_net(&tfile->sk, tfile->net);
2188
2189 tfile->sk.sk_write_space = tun_sock_write_space;
2190 tfile->sk.sk_sndbuf = INT_MAX;
2191
2192 file->private_data = tfile;
2193 set_bit(SOCK_EXTERNALLY_ALLOCATED, &tfile->socket.flags);
2194 INIT_LIST_HEAD(&tfile->next);
2195
2196 sock_set_flag(&tfile->sk, SOCK_ZEROCOPY);
2197
2198 return 0;
2199 }
2200
2201 static int tun_chr_close(struct inode *inode, struct file *file)
2202 {
2203 struct tun_file *tfile = file->private_data;
2204 struct net *net = tfile->net;
2205
2206 tun_detach(tfile, true);
2207 put_net(net);
2208
2209 return 0;
2210 }
2211
2212 #ifdef CONFIG_PROC_FS
2213 static int tun_chr_show_fdinfo(struct seq_file *m, struct file *f)
2214 {
2215 struct tun_struct *tun;
2216 struct ifreq ifr;
2217
2218 memset(&ifr, 0, sizeof(ifr));
2219
2220 rtnl_lock();
2221 tun = tun_get(f);
2222 if (tun)
2223 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
2224 rtnl_unlock();
2225
2226 if (tun)
2227 tun_put(tun);
2228
2229 return seq_printf(m, "iff:\t%s\n", ifr.ifr_name);
2230 }
2231 #endif
2232
2233 static const struct file_operations tun_fops = {
2234 .owner = THIS_MODULE,
2235 .llseek = no_llseek,
2236 .read = do_sync_read,
2237 .aio_read = tun_chr_aio_read,
2238 .write = do_sync_write,
2239 .aio_write = tun_chr_aio_write,
2240 .poll = tun_chr_poll,
2241 .unlocked_ioctl = tun_chr_ioctl,
2242 #ifdef CONFIG_COMPAT
2243 .compat_ioctl = tun_chr_compat_ioctl,
2244 #endif
2245 .open = tun_chr_open,
2246 .release = tun_chr_close,
2247 .fasync = tun_chr_fasync,
2248 #ifdef CONFIG_PROC_FS
2249 .show_fdinfo = tun_chr_show_fdinfo,
2250 #endif
2251 };
2252
2253 static struct miscdevice tun_miscdev = {
2254 .minor = TUN_MINOR,
2255 .name = "tun",
2256 .nodename = "net/tun",
2257 .fops = &tun_fops,
2258 };
2259
2260 /* ethtool interface */
2261
2262 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
2263 {
2264 cmd->supported = 0;
2265 cmd->advertising = 0;
2266 ethtool_cmd_speed_set(cmd, SPEED_10);
2267 cmd->duplex = DUPLEX_FULL;
2268 cmd->port = PORT_TP;
2269 cmd->phy_address = 0;
2270 cmd->transceiver = XCVR_INTERNAL;
2271 cmd->autoneg = AUTONEG_DISABLE;
2272 cmd->maxtxpkt = 0;
2273 cmd->maxrxpkt = 0;
2274 return 0;
2275 }
2276
2277 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
2278 {
2279 struct tun_struct *tun = netdev_priv(dev);
2280
2281 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
2282 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
2283
2284 switch (tun->flags & TUN_TYPE_MASK) {
2285 case TUN_TUN_DEV:
2286 strlcpy(info->bus_info, "tun", sizeof(info->bus_info));
2287 break;
2288 case TUN_TAP_DEV:
2289 strlcpy(info->bus_info, "tap", sizeof(info->bus_info));
2290 break;
2291 }
2292 }
2293
2294 static u32 tun_get_msglevel(struct net_device *dev)
2295 {
2296 #ifdef TUN_DEBUG
2297 struct tun_struct *tun = netdev_priv(dev);
2298 return tun->debug;
2299 #else
2300 return -EOPNOTSUPP;
2301 #endif
2302 }
2303
2304 static void tun_set_msglevel(struct net_device *dev, u32 value)
2305 {
2306 #ifdef TUN_DEBUG
2307 struct tun_struct *tun = netdev_priv(dev);
2308 tun->debug = value;
2309 #endif
2310 }
2311
2312 static const struct ethtool_ops tun_ethtool_ops = {
2313 .get_settings = tun_get_settings,
2314 .get_drvinfo = tun_get_drvinfo,
2315 .get_msglevel = tun_get_msglevel,
2316 .set_msglevel = tun_set_msglevel,
2317 .get_link = ethtool_op_get_link,
2318 .get_ts_info = ethtool_op_get_ts_info,
2319 };
2320
2321
2322 static int __init tun_init(void)
2323 {
2324 int ret = 0;
2325
2326 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
2327 pr_info("%s\n", DRV_COPYRIGHT);
2328
2329 ret = rtnl_link_register(&tun_link_ops);
2330 if (ret) {
2331 pr_err("Can't register link_ops\n");
2332 goto err_linkops;
2333 }
2334
2335 ret = misc_register(&tun_miscdev);
2336 if (ret) {
2337 pr_err("Can't register misc device %d\n", TUN_MINOR);
2338 goto err_misc;
2339 }
2340 return 0;
2341 err_misc:
2342 rtnl_link_unregister(&tun_link_ops);
2343 err_linkops:
2344 return ret;
2345 }
2346
2347 static void tun_cleanup(void)
2348 {
2349 misc_deregister(&tun_miscdev);
2350 rtnl_link_unregister(&tun_link_ops);
2351 }
2352
2353 /* Get an underlying socket object from tun file. Returns error unless file is
2354 * attached to a device. The returned object works like a packet socket, it
2355 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
2356 * holding a reference to the file for as long as the socket is in use. */
2357 struct socket *tun_get_socket(struct file *file)
2358 {
2359 struct tun_file *tfile;
2360 if (file->f_op != &tun_fops)
2361 return ERR_PTR(-EINVAL);
2362 tfile = file->private_data;
2363 if (!tfile)
2364 return ERR_PTR(-EBADFD);
2365 return &tfile->socket;
2366 }
2367 EXPORT_SYMBOL_GPL(tun_get_socket);
2368
2369 module_init(tun_init);
2370 module_exit(tun_cleanup);
2371 MODULE_DESCRIPTION(DRV_DESCRIPTION);
2372 MODULE_AUTHOR(DRV_COPYRIGHT);
2373 MODULE_LICENSE("GPL");
2374 MODULE_ALIAS_MISCDEV(TUN_MINOR);
2375 MODULE_ALIAS("devname:net/tun");
Linux with added FPC-III support