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fix a kmap leak in virtio_console
[linux/fpc-iii.git] / drivers / net / tun.c
blob44c4db8450f0347b4ea6ce861da7f05524ebdb5d
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)
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_assign_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 wake_up_all(&tfile->wq.wait);
502 rcu_assign_pointer(tfile->tun, NULL);
503 --tun->numqueues;
504 }
505 list_for_each_entry(tfile, &tun->disabled, next) {
506 wake_up_all(&tfile->wq.wait);
507 rcu_assign_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 wake_up_interruptible_poll(&tfile->wq.wait, POLLIN |
811 POLLRDNORM | POLLRDBAND);
812
813 rcu_read_unlock();
814 return NETDEV_TX_OK;
815
816 drop:
817 dev->stats.tx_dropped++;
818 skb_tx_error(skb);
819 kfree_skb(skb);
820 rcu_read_unlock();
821 return NETDEV_TX_OK;
822 }
823
824 static void tun_net_mclist(struct net_device *dev)
825 {
826 /*
827 * This callback is supposed to deal with mc filter in
828 * _rx_ path and has nothing to do with the _tx_ path.
829 * In rx path we always accept everything userspace gives us.
830 */
831 }
832
833 #define MIN_MTU 68
834 #define MAX_MTU 65535
835
836 static int
837 tun_net_change_mtu(struct net_device *dev, int new_mtu)
838 {
839 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
840 return -EINVAL;
841 dev->mtu = new_mtu;
842 return 0;
843 }
844
845 static netdev_features_t tun_net_fix_features(struct net_device *dev,
846 netdev_features_t features)
847 {
848 struct tun_struct *tun = netdev_priv(dev);
849
850 return (features & tun->set_features) | (features & ~TUN_USER_FEATURES);
851 }
852 #ifdef CONFIG_NET_POLL_CONTROLLER
853 static void tun_poll_controller(struct net_device *dev)
854 {
855 /*
856 * Tun only receives frames when:
857 * 1) the char device endpoint gets data from user space
858 * 2) the tun socket gets a sendmsg call from user space
859 * Since both of those are synchronous operations, we are guaranteed
860 * never to have pending data when we poll for it
861 * so there is nothing to do here but return.
862 * We need this though so netpoll recognizes us as an interface that
863 * supports polling, which enables bridge devices in virt setups to
864 * still use netconsole
865 */
866 return;
867 }
868 #endif
869 static const struct net_device_ops tun_netdev_ops = {
870 .ndo_uninit = tun_net_uninit,
871 .ndo_open = tun_net_open,
872 .ndo_stop = tun_net_close,
873 .ndo_start_xmit = tun_net_xmit,
874 .ndo_change_mtu = tun_net_change_mtu,
875 .ndo_fix_features = tun_net_fix_features,
876 .ndo_select_queue = tun_select_queue,
877 #ifdef CONFIG_NET_POLL_CONTROLLER
878 .ndo_poll_controller = tun_poll_controller,
879 #endif
880 };
881
882 static const struct net_device_ops tap_netdev_ops = {
883 .ndo_uninit = tun_net_uninit,
884 .ndo_open = tun_net_open,
885 .ndo_stop = tun_net_close,
886 .ndo_start_xmit = tun_net_xmit,
887 .ndo_change_mtu = tun_net_change_mtu,
888 .ndo_fix_features = tun_net_fix_features,
889 .ndo_set_rx_mode = tun_net_mclist,
890 .ndo_set_mac_address = eth_mac_addr,
891 .ndo_validate_addr = eth_validate_addr,
892 .ndo_select_queue = tun_select_queue,
893 #ifdef CONFIG_NET_POLL_CONTROLLER
894 .ndo_poll_controller = tun_poll_controller,
895 #endif
896 };
897
898 static void tun_flow_init(struct tun_struct *tun)
899 {
900 int i;
901
902 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++)
903 INIT_HLIST_HEAD(&tun->flows[i]);
904
905 tun->ageing_time = TUN_FLOW_EXPIRE;
906 setup_timer(&tun->flow_gc_timer, tun_flow_cleanup, (unsigned long)tun);
907 mod_timer(&tun->flow_gc_timer,
908 round_jiffies_up(jiffies + tun->ageing_time));
909 }
910
911 static void tun_flow_uninit(struct tun_struct *tun)
912 {
913 del_timer_sync(&tun->flow_gc_timer);
914 tun_flow_flush(tun);
915 }
916
917 /* Initialize net device. */
918 static void tun_net_init(struct net_device *dev)
919 {
920 struct tun_struct *tun = netdev_priv(dev);
921
922 switch (tun->flags & TUN_TYPE_MASK) {
923 case TUN_TUN_DEV:
924 dev->netdev_ops = &tun_netdev_ops;
925
926 /* Point-to-Point TUN Device */
927 dev->hard_header_len = 0;
928 dev->addr_len = 0;
929 dev->mtu = 1500;
930
931 /* Zero header length */
932 dev->type = ARPHRD_NONE;
933 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
934 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
935 break;
936
937 case TUN_TAP_DEV:
938 dev->netdev_ops = &tap_netdev_ops;
939 /* Ethernet TAP Device */
940 ether_setup(dev);
941 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
942 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
943
944 eth_hw_addr_random(dev);
945
946 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
947 break;
948 }
949 }
950
951 /* Character device part */
952
953 /* Poll */
954 static unsigned int tun_chr_poll(struct file *file, poll_table *wait)
955 {
956 struct tun_file *tfile = file->private_data;
957 struct tun_struct *tun = __tun_get(tfile);
958 struct sock *sk;
959 unsigned int mask = 0;
960
961 if (!tun)
962 return POLLERR;
963
964 sk = tfile->socket.sk;
965
966 tun_debug(KERN_INFO, tun, "tun_chr_poll\n");
967
968 poll_wait(file, &tfile->wq.wait, wait);
969
970 if (!skb_queue_empty(&sk->sk_receive_queue))
971 mask |= POLLIN | POLLRDNORM;
972
973 if (sock_writeable(sk) ||
974 (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
975 sock_writeable(sk)))
976 mask |= POLLOUT | POLLWRNORM;
977
978 if (tun->dev->reg_state != NETREG_REGISTERED)
979 mask = POLLERR;
980
981 tun_put(tun);
982 return mask;
983 }
984
985 /* prepad is the amount to reserve at front. len is length after that.
986 * linear is a hint as to how much to copy (usually headers). */
987 static struct sk_buff *tun_alloc_skb(struct tun_file *tfile,
988 size_t prepad, size_t len,
989 size_t linear, int noblock)
990 {
991 struct sock *sk = tfile->socket.sk;
992 struct sk_buff *skb;
993 int err;
994
995 /* Under a page? Don't bother with paged skb. */
996 if (prepad + len < PAGE_SIZE || !linear)
997 linear = len;
998
999 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
1000 &err, 0);
1001 if (!skb)
1002 return ERR_PTR(err);
1003
1004 skb_reserve(skb, prepad);
1005 skb_put(skb, linear);
1006 skb->data_len = len - linear;
1007 skb->len += len - linear;
1008
1009 return skb;
1010 }
1011
1012 /* Get packet from user space buffer */
1013 static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
1014 void *msg_control, const struct iovec *iv,
1015 size_t total_len, size_t count, int noblock)
1016 {
1017 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
1018 struct sk_buff *skb;
1019 size_t len = total_len, align = NET_SKB_PAD, linear;
1020 struct virtio_net_hdr gso = { 0 };
1021 int good_linear;
1022 int offset = 0;
1023 int copylen;
1024 bool zerocopy = false;
1025 int err;
1026 u32 rxhash;
1027
1028 if (!(tun->flags & TUN_NO_PI)) {
1029 if (len < sizeof(pi))
1030 return -EINVAL;
1031 len -= sizeof(pi);
1032
1033 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
1034 return -EFAULT;
1035 offset += sizeof(pi);
1036 }
1037
1038 if (tun->flags & TUN_VNET_HDR) {
1039 if (len < tun->vnet_hdr_sz)
1040 return -EINVAL;
1041 len -= tun->vnet_hdr_sz;
1042
1043 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
1044 return -EFAULT;
1045
1046 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
1047 gso.csum_start + gso.csum_offset + 2 > gso.hdr_len)
1048 gso.hdr_len = gso.csum_start + gso.csum_offset + 2;
1049
1050 if (gso.hdr_len > len)
1051 return -EINVAL;
1052 offset += tun->vnet_hdr_sz;
1053 }
1054
1055 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
1056 align += NET_IP_ALIGN;
1057 if (unlikely(len < ETH_HLEN ||
1058 (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
1059 return -EINVAL;
1060 }
1061
1062 good_linear = SKB_MAX_HEAD(align);
1063
1064 if (msg_control) {
1065 /* There are 256 bytes to be copied in skb, so there is
1066 * enough room for skb expand head in case it is used.
1067 * The rest of the buffer is mapped from userspace.
1068 */
1069 copylen = gso.hdr_len ? gso.hdr_len : GOODCOPY_LEN;
1070 if (copylen > good_linear)
1071 copylen = good_linear;
1072 linear = copylen;
1073 if (iov_pages(iv, offset + copylen, count) <= MAX_SKB_FRAGS)
1074 zerocopy = true;
1075 }
1076
1077 if (!zerocopy) {
1078 copylen = len;
1079 if (gso.hdr_len > good_linear)
1080 linear = good_linear;
1081 else
1082 linear = gso.hdr_len;
1083 }
1084
1085 skb = tun_alloc_skb(tfile, align, copylen, linear, noblock);
1086 if (IS_ERR(skb)) {
1087 if (PTR_ERR(skb) != -EAGAIN)
1088 tun->dev->stats.rx_dropped++;
1089 return PTR_ERR(skb);
1090 }
1091
1092 if (zerocopy)
1093 err = zerocopy_sg_from_iovec(skb, iv, offset, count);
1094 else {
1095 err = skb_copy_datagram_from_iovec(skb, 0, iv, offset, len);
1096 if (!err && msg_control) {
1097 struct ubuf_info *uarg = msg_control;
1098 uarg->callback(uarg, false);
1099 }
1100 }
1101
1102 if (err) {
1103 tun->dev->stats.rx_dropped++;
1104 kfree_skb(skb);
1105 return -EFAULT;
1106 }
1107
1108 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
1109 if (!skb_partial_csum_set(skb, gso.csum_start,
1110 gso.csum_offset)) {
1111 tun->dev->stats.rx_frame_errors++;
1112 kfree_skb(skb);
1113 return -EINVAL;
1114 }
1115 }
1116
1117 switch (tun->flags & TUN_TYPE_MASK) {
1118 case TUN_TUN_DEV:
1119 if (tun->flags & TUN_NO_PI) {
1120 switch (skb->data[0] & 0xf0) {
1121 case 0x40:
1122 pi.proto = htons(ETH_P_IP);
1123 break;
1124 case 0x60:
1125 pi.proto = htons(ETH_P_IPV6);
1126 break;
1127 default:
1128 tun->dev->stats.rx_dropped++;
1129 kfree_skb(skb);
1130 return -EINVAL;
1131 }
1132 }
1133
1134 skb_reset_mac_header(skb);
1135 skb->protocol = pi.proto;
1136 skb->dev = tun->dev;
1137 break;
1138 case TUN_TAP_DEV:
1139 skb->protocol = eth_type_trans(skb, tun->dev);
1140 break;
1141 }
1142
1143 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
1144 pr_debug("GSO!\n");
1145 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
1146 case VIRTIO_NET_HDR_GSO_TCPV4:
1147 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
1148 break;
1149 case VIRTIO_NET_HDR_GSO_TCPV6:
1150 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
1151 break;
1152 case VIRTIO_NET_HDR_GSO_UDP:
1153 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
1154 break;
1155 default:
1156 tun->dev->stats.rx_frame_errors++;
1157 kfree_skb(skb);
1158 return -EINVAL;
1159 }
1160
1161 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
1162 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
1163
1164 skb_shinfo(skb)->gso_size = gso.gso_size;
1165 if (skb_shinfo(skb)->gso_size == 0) {
1166 tun->dev->stats.rx_frame_errors++;
1167 kfree_skb(skb);
1168 return -EINVAL;
1169 }
1170
1171 /* Header must be checked, and gso_segs computed. */
1172 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
1173 skb_shinfo(skb)->gso_segs = 0;
1174 }
1175
1176 /* copy skb_ubuf_info for callback when skb has no error */
1177 if (zerocopy) {
1178 skb_shinfo(skb)->destructor_arg = msg_control;
1179 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1180 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
1181 }
1182
1183 skb_reset_network_header(skb);
1184 skb_probe_transport_header(skb, 0);
1185
1186 rxhash = skb_get_hash(skb);
1187 netif_rx_ni(skb);
1188
1189 tun->dev->stats.rx_packets++;
1190 tun->dev->stats.rx_bytes += len;
1191
1192 tun_flow_update(tun, rxhash, tfile);
1193 return total_len;
1194 }
1195
1196 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
1197 unsigned long count, loff_t pos)
1198 {
1199 struct file *file = iocb->ki_filp;
1200 struct tun_struct *tun = tun_get(file);
1201 struct tun_file *tfile = file->private_data;
1202 ssize_t result;
1203
1204 if (!tun)
1205 return -EBADFD;
1206
1207 tun_debug(KERN_INFO, tun, "tun_chr_write %ld\n", count);
1208
1209 result = tun_get_user(tun, tfile, NULL, iv, iov_length(iv, count),
1210 count, file->f_flags & O_NONBLOCK);
1211
1212 tun_put(tun);
1213 return result;
1214 }
1215
1216 /* Put packet to the user space buffer */
1217 static ssize_t tun_put_user(struct tun_struct *tun,
1218 struct tun_file *tfile,
1219 struct sk_buff *skb,
1220 const struct iovec *iv, int len)
1221 {
1222 struct tun_pi pi = { 0, skb->protocol };
1223 ssize_t total = 0;
1224 int vlan_offset = 0, copied;
1225
1226 if (!(tun->flags & TUN_NO_PI)) {
1227 if ((len -= sizeof(pi)) < 0)
1228 return -EINVAL;
1229
1230 if (len < skb->len) {
1231 /* Packet will be striped */
1232 pi.flags |= TUN_PKT_STRIP;
1233 }
1234
1235 if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi)))
1236 return -EFAULT;
1237 total += sizeof(pi);
1238 }
1239
1240 if (tun->flags & TUN_VNET_HDR) {
1241 struct virtio_net_hdr gso = { 0 }; /* no info leak */
1242 if ((len -= tun->vnet_hdr_sz) < 0)
1243 return -EINVAL;
1244
1245 if (skb_is_gso(skb)) {
1246 struct skb_shared_info *sinfo = skb_shinfo(skb);
1247
1248 /* This is a hint as to how much should be linear. */
1249 gso.hdr_len = skb_headlen(skb);
1250 gso.gso_size = sinfo->gso_size;
1251 if (sinfo->gso_type & SKB_GSO_TCPV4)
1252 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
1253 else if (sinfo->gso_type & SKB_GSO_TCPV6)
1254 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
1255 else if (sinfo->gso_type & SKB_GSO_UDP)
1256 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
1257 else {
1258 pr_err("unexpected GSO type: "
1259 "0x%x, gso_size %d, hdr_len %d\n",
1260 sinfo->gso_type, gso.gso_size,
1261 gso.hdr_len);
1262 print_hex_dump(KERN_ERR, "tun: ",
1263 DUMP_PREFIX_NONE,
1264 16, 1, skb->head,
1265 min((int)gso.hdr_len, 64), true);
1266 WARN_ON_ONCE(1);
1267 return -EINVAL;
1268 }
1269 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
1270 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
1271 } else
1272 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
1273
1274 if (skb->ip_summed == CHECKSUM_PARTIAL) {
1275 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
1276 gso.csum_start = skb_checksum_start_offset(skb);
1277 gso.csum_offset = skb->csum_offset;
1278 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
1279 gso.flags = VIRTIO_NET_HDR_F_DATA_VALID;
1280 } /* else everything is zero */
1281
1282 if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
1283 sizeof(gso))))
1284 return -EFAULT;
1285 total += tun->vnet_hdr_sz;
1286 }
1287
1288 copied = total;
1289 total += skb->len;
1290 if (!vlan_tx_tag_present(skb)) {
1291 len = min_t(int, skb->len, len);
1292 } else {
1293 int copy, ret;
1294 struct {
1295 __be16 h_vlan_proto;
1296 __be16 h_vlan_TCI;
1297 } veth;
1298
1299 veth.h_vlan_proto = skb->vlan_proto;
1300 veth.h_vlan_TCI = htons(vlan_tx_tag_get(skb));
1301
1302 vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);
1303 len = min_t(int, skb->len + VLAN_HLEN, len);
1304 total += VLAN_HLEN;
1305
1306 copy = min_t(int, vlan_offset, len);
1307 ret = skb_copy_datagram_const_iovec(skb, 0, iv, copied, copy);
1308 len -= copy;
1309 copied += copy;
1310 if (ret || !len)
1311 goto done;
1312
1313 copy = min_t(int, sizeof(veth), len);
1314 ret = memcpy_toiovecend(iv, (void *)&veth, copied, copy);
1315 len -= copy;
1316 copied += copy;
1317 if (ret || !len)
1318 goto done;
1319 }
1320
1321 skb_copy_datagram_const_iovec(skb, vlan_offset, iv, copied, len);
1322
1323 done:
1324 tun->dev->stats.tx_packets++;
1325 tun->dev->stats.tx_bytes += len;
1326
1327 return total;
1328 }
1329
1330 static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
1331 const struct iovec *iv, ssize_t len, int noblock)
1332 {
1333 DECLARE_WAITQUEUE(wait, current);
1334 struct sk_buff *skb;
1335 ssize_t ret = 0;
1336
1337 tun_debug(KERN_INFO, tun, "tun_do_read\n");
1338
1339 if (unlikely(!noblock))
1340 add_wait_queue(&tfile->wq.wait, &wait);
1341 while (len) {
1342 if (unlikely(!noblock))
1343 current->state = TASK_INTERRUPTIBLE;
1344
1345 /* Read frames from the queue */
1346 if (!(skb = skb_dequeue(&tfile->socket.sk->sk_receive_queue))) {
1347 if (noblock) {
1348 ret = -EAGAIN;
1349 break;
1350 }
1351 if (signal_pending(current)) {
1352 ret = -ERESTARTSYS;
1353 break;
1354 }
1355 if (tun->dev->reg_state != NETREG_REGISTERED) {
1356 ret = -EIO;
1357 break;
1358 }
1359
1360 /* Nothing to read, let's sleep */
1361 schedule();
1362 continue;
1363 }
1364
1365 ret = tun_put_user(tun, tfile, skb, iv, len);
1366 kfree_skb(skb);
1367 break;
1368 }
1369
1370 if (unlikely(!noblock)) {
1371 current->state = TASK_RUNNING;
1372 remove_wait_queue(&tfile->wq.wait, &wait);
1373 }
1374
1375 return ret;
1376 }
1377
1378 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
1379 unsigned long count, loff_t pos)
1380 {
1381 struct file *file = iocb->ki_filp;
1382 struct tun_file *tfile = file->private_data;
1383 struct tun_struct *tun = __tun_get(tfile);
1384 ssize_t len, ret;
1385
1386 if (!tun)
1387 return -EBADFD;
1388 len = iov_length(iv, count);
1389 if (len < 0) {
1390 ret = -EINVAL;
1391 goto out;
1392 }
1393
1394 ret = tun_do_read(tun, tfile, iv, len,
1395 file->f_flags & O_NONBLOCK);
1396 ret = min_t(ssize_t, ret, len);
1397 if (ret > 0)
1398 iocb->ki_pos = ret;
1399 out:
1400 tun_put(tun);
1401 return ret;
1402 }
1403
1404 static void tun_free_netdev(struct net_device *dev)
1405 {
1406 struct tun_struct *tun = netdev_priv(dev);
1407
1408 BUG_ON(!(list_empty(&tun->disabled)));
1409 tun_flow_uninit(tun);
1410 security_tun_dev_free_security(tun->security);
1411 free_netdev(dev);
1412 }
1413
1414 static void tun_setup(struct net_device *dev)
1415 {
1416 struct tun_struct *tun = netdev_priv(dev);
1417
1418 tun->owner = INVALID_UID;
1419 tun->group = INVALID_GID;
1420
1421 dev->ethtool_ops = &tun_ethtool_ops;
1422 dev->destructor = tun_free_netdev;
1423 }
1424
1425 /* Trivial set of netlink ops to allow deleting tun or tap
1426 * device with netlink.
1427 */
1428 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
1429 {
1430 return -EINVAL;
1431 }
1432
1433 static struct rtnl_link_ops tun_link_ops __read_mostly = {
1434 .kind = DRV_NAME,
1435 .priv_size = sizeof(struct tun_struct),
1436 .setup = tun_setup,
1437 .validate = tun_validate,
1438 };
1439
1440 static void tun_sock_write_space(struct sock *sk)
1441 {
1442 struct tun_file *tfile;
1443 wait_queue_head_t *wqueue;
1444
1445 if (!sock_writeable(sk))
1446 return;
1447
1448 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
1449 return;
1450
1451 wqueue = sk_sleep(sk);
1452 if (wqueue && waitqueue_active(wqueue))
1453 wake_up_interruptible_sync_poll(wqueue, POLLOUT |
1454 POLLWRNORM | POLLWRBAND);
1455
1456 tfile = container_of(sk, struct tun_file, sk);
1457 kill_fasync(&tfile->fasync, SIGIO, POLL_OUT);
1458 }
1459
1460 static int tun_sendmsg(struct kiocb *iocb, struct socket *sock,
1461 struct msghdr *m, size_t total_len)
1462 {
1463 int ret;
1464 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1465 struct tun_struct *tun = __tun_get(tfile);
1466
1467 if (!tun)
1468 return -EBADFD;
1469 ret = tun_get_user(tun, tfile, m->msg_control, m->msg_iov, total_len,
1470 m->msg_iovlen, m->msg_flags & MSG_DONTWAIT);
1471 tun_put(tun);
1472 return ret;
1473 }
1474
1475 static int tun_recvmsg(struct kiocb *iocb, struct socket *sock,
1476 struct msghdr *m, size_t total_len,
1477 int flags)
1478 {
1479 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1480 struct tun_struct *tun = __tun_get(tfile);
1481 int ret;
1482
1483 if (!tun)
1484 return -EBADFD;
1485
1486 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC|MSG_ERRQUEUE)) {
1487 ret = -EINVAL;
1488 goto out;
1489 }
1490 if (flags & MSG_ERRQUEUE) {
1491 ret = sock_recv_errqueue(sock->sk, m, total_len,
1492 SOL_PACKET, TUN_TX_TIMESTAMP);
1493 goto out;
1494 }
1495 ret = tun_do_read(tun, tfile, m->msg_iov, total_len,
1496 flags & MSG_DONTWAIT);
1497 if (ret > total_len) {
1498 m->msg_flags |= MSG_TRUNC;
1499 ret = flags & MSG_TRUNC ? ret : total_len;
1500 }
1501 out:
1502 tun_put(tun);
1503 return ret;
1504 }
1505
1506 static int tun_release(struct socket *sock)
1507 {
1508 if (sock->sk)
1509 sock_put(sock->sk);
1510 return 0;
1511 }
1512
1513 /* Ops structure to mimic raw sockets with tun */
1514 static const struct proto_ops tun_socket_ops = {
1515 .sendmsg = tun_sendmsg,
1516 .recvmsg = tun_recvmsg,
1517 .release = tun_release,
1518 };
1519
1520 static struct proto tun_proto = {
1521 .name = "tun",
1522 .owner = THIS_MODULE,
1523 .obj_size = sizeof(struct tun_file),
1524 };
1525
1526 static int tun_flags(struct tun_struct *tun)
1527 {
1528 int flags = 0;
1529
1530 if (tun->flags & TUN_TUN_DEV)
1531 flags |= IFF_TUN;
1532 else
1533 flags |= IFF_TAP;
1534
1535 if (tun->flags & TUN_NO_PI)
1536 flags |= IFF_NO_PI;
1537
1538 /* This flag has no real effect. We track the value for backwards
1539 * compatibility.
1540 */
1541 if (tun->flags & TUN_ONE_QUEUE)
1542 flags |= IFF_ONE_QUEUE;
1543
1544 if (tun->flags & TUN_VNET_HDR)
1545 flags |= IFF_VNET_HDR;
1546
1547 if (tun->flags & TUN_TAP_MQ)
1548 flags |= IFF_MULTI_QUEUE;
1549
1550 if (tun->flags & TUN_PERSIST)
1551 flags |= IFF_PERSIST;
1552
1553 return flags;
1554 }
1555
1556 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
1557 char *buf)
1558 {
1559 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1560 return sprintf(buf, "0x%x\n", tun_flags(tun));
1561 }
1562
1563 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
1564 char *buf)
1565 {
1566 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1567 return uid_valid(tun->owner)?
1568 sprintf(buf, "%u\n",
1569 from_kuid_munged(current_user_ns(), tun->owner)):
1570 sprintf(buf, "-1\n");
1571 }
1572
1573 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
1574 char *buf)
1575 {
1576 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1577 return gid_valid(tun->group) ?
1578 sprintf(buf, "%u\n",
1579 from_kgid_munged(current_user_ns(), tun->group)):
1580 sprintf(buf, "-1\n");
1581 }
1582
1583 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
1584 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
1585 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
1586
1587 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
1588 {
1589 struct tun_struct *tun;
1590 struct tun_file *tfile = file->private_data;
1591 struct net_device *dev;
1592 int err;
1593
1594 if (tfile->detached)
1595 return -EINVAL;
1596
1597 dev = __dev_get_by_name(net, ifr->ifr_name);
1598 if (dev) {
1599 if (ifr->ifr_flags & IFF_TUN_EXCL)
1600 return -EBUSY;
1601 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
1602 tun = netdev_priv(dev);
1603 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
1604 tun = netdev_priv(dev);
1605 else
1606 return -EINVAL;
1607
1608 if (!!(ifr->ifr_flags & IFF_MULTI_QUEUE) !=
1609 !!(tun->flags & TUN_TAP_MQ))
1610 return -EINVAL;
1611
1612 if (tun_not_capable(tun))
1613 return -EPERM;
1614 err = security_tun_dev_open(tun->security);
1615 if (err < 0)
1616 return err;
1617
1618 err = tun_attach(tun, file, ifr->ifr_flags & IFF_NOFILTER);
1619 if (err < 0)
1620 return err;
1621
1622 if (tun->flags & TUN_TAP_MQ &&
1623 (tun->numqueues + tun->numdisabled > 1)) {
1624 /* One or more queue has already been attached, no need
1625 * to initialize the device again.
1626 */
1627 return 0;
1628 }
1629 }
1630 else {
1631 char *name;
1632 unsigned long flags = 0;
1633 int queues = ifr->ifr_flags & IFF_MULTI_QUEUE ?
1634 MAX_TAP_QUEUES : 1;
1635
1636 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1637 return -EPERM;
1638 err = security_tun_dev_create();
1639 if (err < 0)
1640 return err;
1641
1642 /* Set dev type */
1643 if (ifr->ifr_flags & IFF_TUN) {
1644 /* TUN device */
1645 flags |= TUN_TUN_DEV;
1646 name = "tun%d";
1647 } else if (ifr->ifr_flags & IFF_TAP) {
1648 /* TAP device */
1649 flags |= TUN_TAP_DEV;
1650 name = "tap%d";
1651 } else
1652 return -EINVAL;
1653
1654 if (*ifr->ifr_name)
1655 name = ifr->ifr_name;
1656
1657 dev = alloc_netdev_mqs(sizeof(struct tun_struct), name,
1658 tun_setup, queues, queues);
1659
1660 if (!dev)
1661 return -ENOMEM;
1662
1663 dev_net_set(dev, net);
1664 dev->rtnl_link_ops = &tun_link_ops;
1665 dev->ifindex = tfile->ifindex;
1666
1667 tun = netdev_priv(dev);
1668 tun->dev = dev;
1669 tun->flags = flags;
1670 tun->txflt.count = 0;
1671 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
1672
1673 tun->filter_attached = false;
1674 tun->sndbuf = tfile->socket.sk->sk_sndbuf;
1675
1676 spin_lock_init(&tun->lock);
1677
1678 err = security_tun_dev_alloc_security(&tun->security);
1679 if (err < 0)
1680 goto err_free_dev;
1681
1682 tun_net_init(dev);
1683 tun_flow_init(tun);
1684
1685 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
1686 TUN_USER_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
1687 NETIF_F_HW_VLAN_STAG_TX;
1688 dev->features = dev->hw_features;
1689 dev->vlan_features = dev->features;
1690
1691 INIT_LIST_HEAD(&tun->disabled);
1692 err = tun_attach(tun, file, false);
1693 if (err < 0)
1694 goto err_free_flow;
1695
1696 err = register_netdevice(tun->dev);
1697 if (err < 0)
1698 goto err_detach;
1699
1700 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
1701 device_create_file(&tun->dev->dev, &dev_attr_owner) ||
1702 device_create_file(&tun->dev->dev, &dev_attr_group))
1703 pr_err("Failed to create tun sysfs files\n");
1704 }
1705
1706 netif_carrier_on(tun->dev);
1707
1708 tun_debug(KERN_INFO, tun, "tun_set_iff\n");
1709
1710 if (ifr->ifr_flags & IFF_NO_PI)
1711 tun->flags |= TUN_NO_PI;
1712 else
1713 tun->flags &= ~TUN_NO_PI;
1714
1715 /* This flag has no real effect. We track the value for backwards
1716 * compatibility.
1717 */
1718 if (ifr->ifr_flags & IFF_ONE_QUEUE)
1719 tun->flags |= TUN_ONE_QUEUE;
1720 else
1721 tun->flags &= ~TUN_ONE_QUEUE;
1722
1723 if (ifr->ifr_flags & IFF_VNET_HDR)
1724 tun->flags |= TUN_VNET_HDR;
1725 else
1726 tun->flags &= ~TUN_VNET_HDR;
1727
1728 if (ifr->ifr_flags & IFF_MULTI_QUEUE)
1729 tun->flags |= TUN_TAP_MQ;
1730 else
1731 tun->flags &= ~TUN_TAP_MQ;
1732
1733 /* Make sure persistent devices do not get stuck in
1734 * xoff state.
1735 */
1736 if (netif_running(tun->dev))
1737 netif_tx_wake_all_queues(tun->dev);
1738
1739 strcpy(ifr->ifr_name, tun->dev->name);
1740 return 0;
1741
1742 err_detach:
1743 tun_detach_all(dev);
1744 err_free_flow:
1745 tun_flow_uninit(tun);
1746 security_tun_dev_free_security(tun->security);
1747 err_free_dev:
1748 free_netdev(dev);
1749 return err;
1750 }
1751
1752 static void tun_get_iff(struct net *net, struct tun_struct *tun,
1753 struct ifreq *ifr)
1754 {
1755 tun_debug(KERN_INFO, tun, "tun_get_iff\n");
1756
1757 strcpy(ifr->ifr_name, tun->dev->name);
1758
1759 ifr->ifr_flags = tun_flags(tun);
1760
1761 }
1762
1763 /* This is like a cut-down ethtool ops, except done via tun fd so no
1764 * privs required. */
1765 static int set_offload(struct tun_struct *tun, unsigned long arg)
1766 {
1767 netdev_features_t features = 0;
1768
1769 if (arg & TUN_F_CSUM) {
1770 features |= NETIF_F_HW_CSUM;
1771 arg &= ~TUN_F_CSUM;
1772
1773 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1774 if (arg & TUN_F_TSO_ECN) {
1775 features |= NETIF_F_TSO_ECN;
1776 arg &= ~TUN_F_TSO_ECN;
1777 }
1778 if (arg & TUN_F_TSO4)
1779 features |= NETIF_F_TSO;
1780 if (arg & TUN_F_TSO6)
1781 features |= NETIF_F_TSO6;
1782 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1783 }
1784
1785 if (arg & TUN_F_UFO) {
1786 features |= NETIF_F_UFO;
1787 arg &= ~TUN_F_UFO;
1788 }
1789 }
1790
1791 /* This gives the user a way to test for new features in future by
1792 * trying to set them. */
1793 if (arg)
1794 return -EINVAL;
1795
1796 tun->set_features = features;
1797 netdev_update_features(tun->dev);
1798
1799 return 0;
1800 }
1801
1802 static void tun_detach_filter(struct tun_struct *tun, int n)
1803 {
1804 int i;
1805 struct tun_file *tfile;
1806
1807 for (i = 0; i < n; i++) {
1808 tfile = rtnl_dereference(tun->tfiles[i]);
1809 sk_detach_filter(tfile->socket.sk);
1810 }
1811
1812 tun->filter_attached = false;
1813 }
1814
1815 static int tun_attach_filter(struct tun_struct *tun)
1816 {
1817 int i, ret = 0;
1818 struct tun_file *tfile;
1819
1820 for (i = 0; i < tun->numqueues; i++) {
1821 tfile = rtnl_dereference(tun->tfiles[i]);
1822 ret = sk_attach_filter(&tun->fprog, tfile->socket.sk);
1823 if (ret) {
1824 tun_detach_filter(tun, i);
1825 return ret;
1826 }
1827 }
1828
1829 tun->filter_attached = true;
1830 return ret;
1831 }
1832
1833 static void tun_set_sndbuf(struct tun_struct *tun)
1834 {
1835 struct tun_file *tfile;
1836 int i;
1837
1838 for (i = 0; i < tun->numqueues; i++) {
1839 tfile = rtnl_dereference(tun->tfiles[i]);
1840 tfile->socket.sk->sk_sndbuf = tun->sndbuf;
1841 }
1842 }
1843
1844 static int tun_set_queue(struct file *file, struct ifreq *ifr)
1845 {
1846 struct tun_file *tfile = file->private_data;
1847 struct tun_struct *tun;
1848 int ret = 0;
1849
1850 rtnl_lock();
1851
1852 if (ifr->ifr_flags & IFF_ATTACH_QUEUE) {
1853 tun = tfile->detached;
1854 if (!tun) {
1855 ret = -EINVAL;
1856 goto unlock;
1857 }
1858 ret = security_tun_dev_attach_queue(tun->security);
1859 if (ret < 0)
1860 goto unlock;
1861 ret = tun_attach(tun, file, false);
1862 } else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
1863 tun = rtnl_dereference(tfile->tun);
1864 if (!tun || !(tun->flags & TUN_TAP_MQ) || tfile->detached)
1865 ret = -EINVAL;
1866 else
1867 __tun_detach(tfile, false);
1868 } else
1869 ret = -EINVAL;
1870
1871 unlock:
1872 rtnl_unlock();
1873 return ret;
1874 }
1875
1876 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
1877 unsigned long arg, int ifreq_len)
1878 {
1879 struct tun_file *tfile = file->private_data;
1880 struct tun_struct *tun;
1881 void __user* argp = (void __user*)arg;
1882 struct ifreq ifr;
1883 kuid_t owner;
1884 kgid_t group;
1885 int sndbuf;
1886 int vnet_hdr_sz;
1887 unsigned int ifindex;
1888 int ret;
1889
1890 if (cmd == TUNSETIFF || cmd == TUNSETQUEUE || _IOC_TYPE(cmd) == 0x89) {
1891 if (copy_from_user(&ifr, argp, ifreq_len))
1892 return -EFAULT;
1893 } else {
1894 memset(&ifr, 0, sizeof(ifr));
1895 }
1896 if (cmd == TUNGETFEATURES) {
1897 /* Currently this just means: "what IFF flags are valid?".
1898 * This is needed because we never checked for invalid flags on
1899 * TUNSETIFF. */
1900 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
1901 IFF_VNET_HDR | IFF_MULTI_QUEUE,
1902 (unsigned int __user*)argp);
1903 } else if (cmd == TUNSETQUEUE)
1904 return tun_set_queue(file, &ifr);
1905
1906 ret = 0;
1907 rtnl_lock();
1908
1909 tun = __tun_get(tfile);
1910 if (cmd == TUNSETIFF && !tun) {
1911 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1912
1913 ret = tun_set_iff(tfile->net, file, &ifr);
1914
1915 if (ret)
1916 goto unlock;
1917
1918 if (copy_to_user(argp, &ifr, ifreq_len))
1919 ret = -EFAULT;
1920 goto unlock;
1921 }
1922 if (cmd == TUNSETIFINDEX) {
1923 ret = -EPERM;
1924 if (tun)
1925 goto unlock;
1926
1927 ret = -EFAULT;
1928 if (copy_from_user(&ifindex, argp, sizeof(ifindex)))
1929 goto unlock;
1930
1931 ret = 0;
1932 tfile->ifindex = ifindex;
1933 goto unlock;
1934 }
1935
1936 ret = -EBADFD;
1937 if (!tun)
1938 goto unlock;
1939
1940 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %u\n", cmd);
1941
1942 ret = 0;
1943 switch (cmd) {
1944 case TUNGETIFF:
1945 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1946
1947 if (tfile->detached)
1948 ifr.ifr_flags |= IFF_DETACH_QUEUE;
1949 if (!tfile->socket.sk->sk_filter)
1950 ifr.ifr_flags |= IFF_NOFILTER;
1951
1952 if (copy_to_user(argp, &ifr, ifreq_len))
1953 ret = -EFAULT;
1954 break;
1955
1956 case TUNSETNOCSUM:
1957 /* Disable/Enable checksum */
1958
1959 /* [unimplemented] */
1960 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n",
1961 arg ? "disabled" : "enabled");
1962 break;
1963
1964 case TUNSETPERSIST:
1965 /* Disable/Enable persist mode. Keep an extra reference to the
1966 * module to prevent the module being unprobed.
1967 */
1968 if (arg && !(tun->flags & TUN_PERSIST)) {
1969 tun->flags |= TUN_PERSIST;
1970 __module_get(THIS_MODULE);
1971 }
1972 if (!arg && (tun->flags & TUN_PERSIST)) {
1973 tun->flags &= ~TUN_PERSIST;
1974 module_put(THIS_MODULE);
1975 }
1976
1977 tun_debug(KERN_INFO, tun, "persist %s\n",
1978 arg ? "enabled" : "disabled");
1979 break;
1980
1981 case TUNSETOWNER:
1982 /* Set owner of the device */
1983 owner = make_kuid(current_user_ns(), arg);
1984 if (!uid_valid(owner)) {
1985 ret = -EINVAL;
1986 break;
1987 }
1988 tun->owner = owner;
1989 tun_debug(KERN_INFO, tun, "owner set to %u\n",
1990 from_kuid(&init_user_ns, tun->owner));
1991 break;
1992
1993 case TUNSETGROUP:
1994 /* Set group of the device */
1995 group = make_kgid(current_user_ns(), arg);
1996 if (!gid_valid(group)) {
1997 ret = -EINVAL;
1998 break;
1999 }
2000 tun->group = group;
2001 tun_debug(KERN_INFO, tun, "group set to %u\n",
2002 from_kgid(&init_user_ns, tun->group));
2003 break;
2004
2005 case TUNSETLINK:
2006 /* Only allow setting the type when the interface is down */
2007 if (tun->dev->flags & IFF_UP) {
2008 tun_debug(KERN_INFO, tun,
2009 "Linktype set failed because interface is up\n");
2010 ret = -EBUSY;
2011 } else {
2012 tun->dev->type = (int) arg;
2013 tun_debug(KERN_INFO, tun, "linktype set to %d\n",
2014 tun->dev->type);
2015 ret = 0;
2016 }
2017 break;
2018
2019 #ifdef TUN_DEBUG
2020 case TUNSETDEBUG:
2021 tun->debug = arg;
2022 break;
2023 #endif
2024 case TUNSETOFFLOAD:
2025 ret = set_offload(tun, arg);
2026 break;
2027
2028 case TUNSETTXFILTER:
2029 /* Can be set only for TAPs */
2030 ret = -EINVAL;
2031 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
2032 break;
2033 ret = update_filter(&tun->txflt, (void __user *)arg);
2034 break;
2035
2036 case SIOCGIFHWADDR:
2037 /* Get hw address */
2038 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
2039 ifr.ifr_hwaddr.sa_family = tun->dev->type;
2040 if (copy_to_user(argp, &ifr, ifreq_len))
2041 ret = -EFAULT;
2042 break;
2043
2044 case SIOCSIFHWADDR:
2045 /* Set hw address */
2046 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
2047 ifr.ifr_hwaddr.sa_data);
2048
2049 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
2050 break;
2051
2052 case TUNGETSNDBUF:
2053 sndbuf = tfile->socket.sk->sk_sndbuf;
2054 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
2055 ret = -EFAULT;
2056 break;
2057
2058 case TUNSETSNDBUF:
2059 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
2060 ret = -EFAULT;
2061 break;
2062 }
2063
2064 tun->sndbuf = sndbuf;
2065 tun_set_sndbuf(tun);
2066 break;
2067
2068 case TUNGETVNETHDRSZ:
2069 vnet_hdr_sz = tun->vnet_hdr_sz;
2070 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
2071 ret = -EFAULT;
2072 break;
2073
2074 case TUNSETVNETHDRSZ:
2075 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
2076 ret = -EFAULT;
2077 break;
2078 }
2079 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
2080 ret = -EINVAL;
2081 break;
2082 }
2083
2084 tun->vnet_hdr_sz = vnet_hdr_sz;
2085 break;
2086
2087 case TUNATTACHFILTER:
2088 /* Can be set only for TAPs */
2089 ret = -EINVAL;
2090 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
2091 break;
2092 ret = -EFAULT;
2093 if (copy_from_user(&tun->fprog, argp, sizeof(tun->fprog)))
2094 break;
2095
2096 ret = tun_attach_filter(tun);
2097 break;
2098
2099 case TUNDETACHFILTER:
2100 /* Can be set only for TAPs */
2101 ret = -EINVAL;
2102 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
2103 break;
2104 ret = 0;
2105 tun_detach_filter(tun, tun->numqueues);
2106 break;
2107
2108 case TUNGETFILTER:
2109 ret = -EINVAL;
2110 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
2111 break;
2112 ret = -EFAULT;
2113 if (copy_to_user(argp, &tun->fprog, sizeof(tun->fprog)))
2114 break;
2115 ret = 0;
2116 break;
2117
2118 default:
2119 ret = -EINVAL;
2120 break;
2121 }
2122
2123 unlock:
2124 rtnl_unlock();
2125 if (tun)
2126 tun_put(tun);
2127 return ret;
2128 }
2129
2130 static long tun_chr_ioctl(struct file *file,
2131 unsigned int cmd, unsigned long arg)
2132 {
2133 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
2134 }
2135
2136 #ifdef CONFIG_COMPAT
2137 static long tun_chr_compat_ioctl(struct file *file,
2138 unsigned int cmd, unsigned long arg)
2139 {
2140 switch (cmd) {
2141 case TUNSETIFF:
2142 case TUNGETIFF:
2143 case TUNSETTXFILTER:
2144 case TUNGETSNDBUF:
2145 case TUNSETSNDBUF:
2146 case SIOCGIFHWADDR:
2147 case SIOCSIFHWADDR:
2148 arg = (unsigned long)compat_ptr(arg);
2149 break;
2150 default:
2151 arg = (compat_ulong_t)arg;
2152 break;
2153 }
2154
2155 /*
2156 * compat_ifreq is shorter than ifreq, so we must not access beyond
2157 * the end of that structure. All fields that are used in this
2158 * driver are compatible though, we don't need to convert the
2159 * contents.
2160 */
2161 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
2162 }
2163 #endif /* CONFIG_COMPAT */
2164
2165 static int tun_chr_fasync(int fd, struct file *file, int on)
2166 {
2167 struct tun_file *tfile = file->private_data;
2168 int ret;
2169
2170 if ((ret = fasync_helper(fd, file, on, &tfile->fasync)) < 0)
2171 goto out;
2172
2173 if (on) {
2174 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
2175 if (ret)
2176 goto out;
2177 tfile->flags |= TUN_FASYNC;
2178 } else
2179 tfile->flags &= ~TUN_FASYNC;
2180 ret = 0;
2181 out:
2182 return ret;
2183 }
2184
2185 static int tun_chr_open(struct inode *inode, struct file * file)
2186 {
2187 struct tun_file *tfile;
2188
2189 DBG1(KERN_INFO, "tunX: tun_chr_open\n");
2190
2191 tfile = (struct tun_file *)sk_alloc(&init_net, AF_UNSPEC, GFP_KERNEL,
2192 &tun_proto);
2193 if (!tfile)
2194 return -ENOMEM;
2195 rcu_assign_pointer(tfile->tun, NULL);
2196 tfile->net = get_net(current->nsproxy->net_ns);
2197 tfile->flags = 0;
2198 tfile->ifindex = 0;
2199
2200 rcu_assign_pointer(tfile->socket.wq, &tfile->wq);
2201 init_waitqueue_head(&tfile->wq.wait);
2202
2203 tfile->socket.file = file;
2204 tfile->socket.ops = &tun_socket_ops;
2205
2206 sock_init_data(&tfile->socket, &tfile->sk);
2207 sk_change_net(&tfile->sk, tfile->net);
2208
2209 tfile->sk.sk_write_space = tun_sock_write_space;
2210 tfile->sk.sk_sndbuf = INT_MAX;
2211
2212 file->private_data = tfile;
2213 set_bit(SOCK_EXTERNALLY_ALLOCATED, &tfile->socket.flags);
2214 INIT_LIST_HEAD(&tfile->next);
2215
2216 sock_set_flag(&tfile->sk, SOCK_ZEROCOPY);
2217
2218 return 0;
2219 }
2220
2221 static int tun_chr_close(struct inode *inode, struct file *file)
2222 {
2223 struct tun_file *tfile = file->private_data;
2224 struct net *net = tfile->net;
2225
2226 tun_detach(tfile, true);
2227 put_net(net);
2228
2229 return 0;
2230 }
2231
2232 #ifdef CONFIG_PROC_FS
2233 static int tun_chr_show_fdinfo(struct seq_file *m, struct file *f)
2234 {
2235 struct tun_struct *tun;
2236 struct ifreq ifr;
2237
2238 memset(&ifr, 0, sizeof(ifr));
2239
2240 rtnl_lock();
2241 tun = tun_get(f);
2242 if (tun)
2243 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
2244 rtnl_unlock();
2245
2246 if (tun)
2247 tun_put(tun);
2248
2249 return seq_printf(m, "iff:\t%s\n", ifr.ifr_name);
2250 }
2251 #endif
2252
2253 static const struct file_operations tun_fops = {
2254 .owner = THIS_MODULE,
2255 .llseek = no_llseek,
2256 .read = do_sync_read,
2257 .aio_read = tun_chr_aio_read,
2258 .write = do_sync_write,
2259 .aio_write = tun_chr_aio_write,
2260 .poll = tun_chr_poll,
2261 .unlocked_ioctl = tun_chr_ioctl,
2262 #ifdef CONFIG_COMPAT
2263 .compat_ioctl = tun_chr_compat_ioctl,
2264 #endif
2265 .open = tun_chr_open,
2266 .release = tun_chr_close,
2267 .fasync = tun_chr_fasync,
2268 #ifdef CONFIG_PROC_FS
2269 .show_fdinfo = tun_chr_show_fdinfo,
2270 #endif
2271 };
2272
2273 static struct miscdevice tun_miscdev = {
2274 .minor = TUN_MINOR,
2275 .name = "tun",
2276 .nodename = "net/tun",
2277 .fops = &tun_fops,
2278 };
2279
2280 /* ethtool interface */
2281
2282 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
2283 {
2284 cmd->supported = 0;
2285 cmd->advertising = 0;
2286 ethtool_cmd_speed_set(cmd, SPEED_10);
2287 cmd->duplex = DUPLEX_FULL;
2288 cmd->port = PORT_TP;
2289 cmd->phy_address = 0;
2290 cmd->transceiver = XCVR_INTERNAL;
2291 cmd->autoneg = AUTONEG_DISABLE;
2292 cmd->maxtxpkt = 0;
2293 cmd->maxrxpkt = 0;
2294 return 0;
2295 }
2296
2297 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
2298 {
2299 struct tun_struct *tun = netdev_priv(dev);
2300
2301 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
2302 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
2303
2304 switch (tun->flags & TUN_TYPE_MASK) {
2305 case TUN_TUN_DEV:
2306 strlcpy(info->bus_info, "tun", sizeof(info->bus_info));
2307 break;
2308 case TUN_TAP_DEV:
2309 strlcpy(info->bus_info, "tap", sizeof(info->bus_info));
2310 break;
2311 }
2312 }
2313
2314 static u32 tun_get_msglevel(struct net_device *dev)
2315 {
2316 #ifdef TUN_DEBUG
2317 struct tun_struct *tun = netdev_priv(dev);
2318 return tun->debug;
2319 #else
2320 return -EOPNOTSUPP;
2321 #endif
2322 }
2323
2324 static void tun_set_msglevel(struct net_device *dev, u32 value)
2325 {
2326 #ifdef TUN_DEBUG
2327 struct tun_struct *tun = netdev_priv(dev);
2328 tun->debug = value;
2329 #endif
2330 }
2331
2332 static const struct ethtool_ops tun_ethtool_ops = {
2333 .get_settings = tun_get_settings,
2334 .get_drvinfo = tun_get_drvinfo,
2335 .get_msglevel = tun_get_msglevel,
2336 .set_msglevel = tun_set_msglevel,
2337 .get_link = ethtool_op_get_link,
2338 .get_ts_info = ethtool_op_get_ts_info,
2339 };
2340
2341
2342 static int __init tun_init(void)
2343 {
2344 int ret = 0;
2345
2346 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
2347 pr_info("%s\n", DRV_COPYRIGHT);
2348
2349 ret = rtnl_link_register(&tun_link_ops);
2350 if (ret) {
2351 pr_err("Can't register link_ops\n");
2352 goto err_linkops;
2353 }
2354
2355 ret = misc_register(&tun_miscdev);
2356 if (ret) {
2357 pr_err("Can't register misc device %d\n", TUN_MINOR);
2358 goto err_misc;
2359 }
2360 return 0;
2361 err_misc:
2362 rtnl_link_unregister(&tun_link_ops);
2363 err_linkops:
2364 return ret;
2365 }
2366
2367 static void tun_cleanup(void)
2368 {
2369 misc_deregister(&tun_miscdev);
2370 rtnl_link_unregister(&tun_link_ops);
2371 }
2372
2373 /* Get an underlying socket object from tun file. Returns error unless file is
2374 * attached to a device. The returned object works like a packet socket, it
2375 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
2376 * holding a reference to the file for as long as the socket is in use. */
2377 struct socket *tun_get_socket(struct file *file)
2378 {
2379 struct tun_file *tfile;
2380 if (file->f_op != &tun_fops)
2381 return ERR_PTR(-EINVAL);
2382 tfile = file->private_data;
2383 if (!tfile)
2384 return ERR_PTR(-EBADFD);
2385 return &tfile->socket;
2386 }
2387 EXPORT_SYMBOL_GPL(tun_get_socket);
2388
2389 module_init(tun_init);
2390 module_exit(tun_cleanup);
2391 MODULE_DESCRIPTION(DRV_DESCRIPTION);
2392 MODULE_AUTHOR(DRV_COPYRIGHT);
2393 MODULE_LICENSE("GPL");
2394 MODULE_ALIAS_MISCDEV(TUN_MINOR);
2395 MODULE_ALIAS("devname:net/tun");
Linux with added FPC-III support