projects / deliverable / linux.git / blob
? search:


5dce262f538ecc8bfb46df05d33e54c5577299dd
[deliverable/linux.git] / drivers / net / tun.c
1 /*
2 * TUN - Universal TUN/TAP device driver.
3 * Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $
16 */
17
18 /*
19 * Changes:
20 *
21 * Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
22 * Add TUNSETLINK ioctl to set the link encapsulation
23 *
24 * Mark Smith <markzzzsmith@yahoo.com.au>
25 * Use eth_random_addr() for tap MAC address.
26 *
27 * Harald Roelle <harald.roelle@ifi.lmu.de> 2004/04/20
28 * Fixes in packet dropping, queue length setting and queue wakeup.
29 * Increased default tx queue length.
30 * Added ethtool API.
31 * Minor cleanups
32 *
33 * Daniel Podlejski <underley@underley.eu.org>
34 * Modifications for 2.3.99-pre5 kernel.
35 */
36
37 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
38
39 #define DRV_NAME "tun"
40 #define DRV_VERSION "1.6"
41 #define DRV_DESCRIPTION "Universal TUN/TAP device driver"
42 #define DRV_COPYRIGHT "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>"
43
44 #include <linux/module.h>
45 #include <linux/errno.h>
46 #include <linux/kernel.h>
47 #include <linux/major.h>
48 #include <linux/slab.h>
49 #include <linux/poll.h>
50 #include <linux/fcntl.h>
51 #include <linux/init.h>
52 #include <linux/skbuff.h>
53 #include <linux/netdevice.h>
54 #include <linux/etherdevice.h>
55 #include <linux/miscdevice.h>
56 #include <linux/ethtool.h>
57 #include <linux/rtnetlink.h>
58 #include <linux/compat.h>
59 #include <linux/if.h>
60 #include <linux/if_arp.h>
61 #include <linux/if_ether.h>
62 #include <linux/if_tun.h>
63 #include <linux/if_vlan.h>
64 #include <linux/crc32.h>
65 #include <linux/nsproxy.h>
66 #include <linux/virtio_net.h>
67 #include <linux/rcupdate.h>
68 #include <net/net_namespace.h>
69 #include <net/netns/generic.h>
70 #include <net/rtnetlink.h>
71 #include <net/sock.h>
72
73 #include <asm/uaccess.h>
74
75 /* Uncomment to enable debugging */
76 /* #define TUN_DEBUG 1 */
77
78 #ifdef TUN_DEBUG
79 static int debug;
80
81 #define tun_debug(level, tun, fmt, args...) \
82 do { \
83 if (tun->debug) \
84 netdev_printk(level, tun->dev, fmt, ##args); \
85 } while (0)
86 #define DBG1(level, fmt, args...) \
87 do { \
88 if (debug == 2) \
89 printk(level fmt, ##args); \
90 } while (0)
91 #else
92 #define tun_debug(level, tun, fmt, args...) \
93 do { \
94 if (0) \
95 netdev_printk(level, tun->dev, fmt, ##args); \
96 } while (0)
97 #define DBG1(level, fmt, args...) \
98 do { \
99 if (0) \
100 printk(level fmt, ##args); \
101 } while (0)
102 #endif
103
104 #define GOODCOPY_LEN 128
105
106 #define FLT_EXACT_COUNT 8
107 struct tap_filter {
108 unsigned int count; /* Number of addrs. Zero means disabled */
109 u32 mask[2]; /* Mask of the hashed addrs */
110 unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN];
111 };
112
113 /* DEFAULT_MAX_NUM_RSS_QUEUES were choosed to let the rx/tx queues allocated for
114 * the netdevice to be fit in one page. So we can make sure the success of
115 * memory allocation. TODO: increase the limit. */
116 #define MAX_TAP_QUEUES DEFAULT_MAX_NUM_RSS_QUEUES
117 #define MAX_TAP_FLOWS 4096
118
119 #define TUN_FLOW_EXPIRE (3 * HZ)
120
121 /* A tun_file connects an open character device to a tuntap netdevice. It
122 * also contains all socket related strctures (except sock_fprog and tap_filter)
123 * to serve as one transmit queue for tuntap device. The sock_fprog and
124 * tap_filter were kept in tun_struct since they were used for filtering for the
125 * netdevice not for a specific queue (at least I didn't see the requirement for
126 * this).
127 *
128 * RCU usage:
129 * The tun_file and tun_struct are loosely coupled, the pointer from one to the
130 * other can only be read while rcu_read_lock or rtnl_lock is held.
131 */
132 struct tun_file {
133 struct sock sk;
134 struct socket socket;
135 struct socket_wq wq;
136 struct tun_struct __rcu *tun;
137 struct net *net;
138 struct fasync_struct *fasync;
139 /* only used for fasnyc */
140 unsigned int flags;
141 u16 queue_index;
142 struct list_head next;
143 struct tun_struct *detached;
144 };
145
146 struct tun_flow_entry {
147 struct hlist_node hash_link;
148 struct rcu_head rcu;
149 struct tun_struct *tun;
150
151 u32 rxhash;
152 int queue_index;
153 unsigned long updated;
154 };
155
156 #define TUN_NUM_FLOW_ENTRIES 1024
157
158 /* Since the socket were moved to tun_file, to preserve the behavior of persist
159 * device, socket filter, sndbuf and vnet header size were restore when the
160 * file were attached to a persist device.
161 */
162 struct tun_struct {
163 struct tun_file __rcu *tfiles[MAX_TAP_QUEUES];
164 unsigned int numqueues;
165 unsigned int flags;
166 kuid_t owner;
167 kgid_t group;
168
169 struct net_device *dev;
170 netdev_features_t set_features;
171 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
172 NETIF_F_TSO6|NETIF_F_UFO)
173
174 int vnet_hdr_sz;
175 int sndbuf;
176 struct tap_filter txflt;
177 struct sock_fprog fprog;
178 /* protected by rtnl lock */
179 bool filter_attached;
180 #ifdef TUN_DEBUG
181 int debug;
182 #endif
183 spinlock_t lock;
184 struct hlist_head flows[TUN_NUM_FLOW_ENTRIES];
185 struct timer_list flow_gc_timer;
186 unsigned long ageing_time;
187 unsigned int numdisabled;
188 struct list_head disabled;
189 void *security;
190 u32 flow_count;
191 };
192
193 static inline u32 tun_hashfn(u32 rxhash)
194 {
195 return rxhash & 0x3ff;
196 }
197
198 static struct tun_flow_entry *tun_flow_find(struct hlist_head *head, u32 rxhash)
199 {
200 struct tun_flow_entry *e;
201
202 hlist_for_each_entry_rcu(e, head, hash_link) {
203 if (e->rxhash == rxhash)
204 return e;
205 }
206 return NULL;
207 }
208
209 static struct tun_flow_entry *tun_flow_create(struct tun_struct *tun,
210 struct hlist_head *head,
211 u32 rxhash, u16 queue_index)
212 {
213 struct tun_flow_entry *e = kmalloc(sizeof(*e), GFP_ATOMIC);
214
215 if (e) {
216 tun_debug(KERN_INFO, tun, "create flow: hash %u index %u\n",
217 rxhash, queue_index);
218 e->updated = jiffies;
219 e->rxhash = rxhash;
220 e->queue_index = queue_index;
221 e->tun = tun;
222 hlist_add_head_rcu(&e->hash_link, head);
223 ++tun->flow_count;
224 }
225 return e;
226 }
227
228 static void tun_flow_delete(struct tun_struct *tun, struct tun_flow_entry *e)
229 {
230 tun_debug(KERN_INFO, tun, "delete flow: hash %u index %u\n",
231 e->rxhash, e->queue_index);
232 hlist_del_rcu(&e->hash_link);
233 kfree_rcu(e, rcu);
234 --tun->flow_count;
235 }
236
237 static void tun_flow_flush(struct tun_struct *tun)
238 {
239 int i;
240
241 spin_lock_bh(&tun->lock);
242 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
243 struct tun_flow_entry *e;
244 struct hlist_node *n;
245
246 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link)
247 tun_flow_delete(tun, e);
248 }
249 spin_unlock_bh(&tun->lock);
250 }
251
252 static void tun_flow_delete_by_queue(struct tun_struct *tun, u16 queue_index)
253 {
254 int i;
255
256 spin_lock_bh(&tun->lock);
257 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
258 struct tun_flow_entry *e;
259 struct hlist_node *n;
260
261 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
262 if (e->queue_index == queue_index)
263 tun_flow_delete(tun, e);
264 }
265 }
266 spin_unlock_bh(&tun->lock);
267 }
268
269 static void tun_flow_cleanup(unsigned long data)
270 {
271 struct tun_struct *tun = (struct tun_struct *)data;
272 unsigned long delay = tun->ageing_time;
273 unsigned long next_timer = jiffies + delay;
274 unsigned long count = 0;
275 int i;
276
277 tun_debug(KERN_INFO, tun, "tun_flow_cleanup\n");
278
279 spin_lock_bh(&tun->lock);
280 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
281 struct tun_flow_entry *e;
282 struct hlist_node *n;
283
284 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
285 unsigned long this_timer;
286 count++;
287 this_timer = e->updated + delay;
288 if (time_before_eq(this_timer, jiffies))
289 tun_flow_delete(tun, e);
290 else if (time_before(this_timer, next_timer))
291 next_timer = this_timer;
292 }
293 }
294
295 if (count)
296 mod_timer(&tun->flow_gc_timer, round_jiffies_up(next_timer));
297 spin_unlock_bh(&tun->lock);
298 }
299
300 static void tun_flow_update(struct tun_struct *tun, u32 rxhash,
301 struct tun_file *tfile)
302 {
303 struct hlist_head *head;
304 struct tun_flow_entry *e;
305 unsigned long delay = tun->ageing_time;
306 u16 queue_index = tfile->queue_index;
307
308 if (!rxhash)
309 return;
310 else
311 head = &tun->flows[tun_hashfn(rxhash)];
312
313 rcu_read_lock();
314
315 /* We may get a very small possibility of OOO during switching, not
316 * worth to optimize.*/
317 if (tun->numqueues == 1 || tfile->detached)
318 goto unlock;
319
320 e = tun_flow_find(head, rxhash);
321 if (likely(e)) {
322 /* TODO: keep queueing to old queue until it's empty? */
323 e->queue_index = queue_index;
324 e->updated = jiffies;
325 } else {
326 spin_lock_bh(&tun->lock);
327 if (!tun_flow_find(head, rxhash) &&
328 tun->flow_count < MAX_TAP_FLOWS)
329 tun_flow_create(tun, head, rxhash, queue_index);
330
331 if (!timer_pending(&tun->flow_gc_timer))
332 mod_timer(&tun->flow_gc_timer,
333 round_jiffies_up(jiffies + delay));
334 spin_unlock_bh(&tun->lock);
335 }
336
337 unlock:
338 rcu_read_unlock();
339 }
340
341 /* We try to identify a flow through its rxhash first. The reason that
342 * we do not check rxq no. is becuase some cards(e.g 82599), chooses
343 * the rxq based on the txq where the last packet of the flow comes. As
344 * the userspace application move between processors, we may get a
345 * different rxq no. here. If we could not get rxhash, then we would
346 * hope the rxq no. may help here.
347 */
348 static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb)
349 {
350 struct tun_struct *tun = netdev_priv(dev);
351 struct tun_flow_entry *e;
352 u32 txq = 0;
353 u32 numqueues = 0;
354
355 rcu_read_lock();
356 numqueues = ACCESS_ONCE(tun->numqueues);
357
358 txq = skb_get_rxhash(skb);
359 if (txq) {
360 e = tun_flow_find(&tun->flows[tun_hashfn(txq)], txq);
361 if (e)
362 txq = e->queue_index;
363 else
364 /* use multiply and shift instead of expensive divide */
365 txq = ((u64)txq * numqueues) >> 32;
366 } else if (likely(skb_rx_queue_recorded(skb))) {
367 txq = skb_get_rx_queue(skb);
368 while (unlikely(txq >= numqueues))
369 txq -= numqueues;
370 }
371
372 rcu_read_unlock();
373 return txq;
374 }
375
376 static inline bool tun_not_capable(struct tun_struct *tun)
377 {
378 const struct cred *cred = current_cred();
379 struct net *net = dev_net(tun->dev);
380
381 return ((uid_valid(tun->owner) && !uid_eq(cred->euid, tun->owner)) ||
382 (gid_valid(tun->group) && !in_egroup_p(tun->group))) &&
383 !ns_capable(net->user_ns, CAP_NET_ADMIN);
384 }
385
386 static void tun_set_real_num_queues(struct tun_struct *tun)
387 {
388 netif_set_real_num_tx_queues(tun->dev, tun->numqueues);
389 netif_set_real_num_rx_queues(tun->dev, tun->numqueues);
390 }
391
392 static void tun_disable_queue(struct tun_struct *tun, struct tun_file *tfile)
393 {
394 tfile->detached = tun;
395 list_add_tail(&tfile->next, &tun->disabled);
396 ++tun->numdisabled;
397 }
398
399 static struct tun_struct *tun_enable_queue(struct tun_file *tfile)
400 {
401 struct tun_struct *tun = tfile->detached;
402
403 tfile->detached = NULL;
404 list_del_init(&tfile->next);
405 --tun->numdisabled;
406 return tun;
407 }
408
409 static void __tun_detach(struct tun_file *tfile, bool clean)
410 {
411 struct tun_file *ntfile;
412 struct tun_struct *tun;
413
414 tun = rtnl_dereference(tfile->tun);
415
416 if (tun && !tfile->detached) {
417 u16 index = tfile->queue_index;
418 BUG_ON(index >= tun->numqueues);
419
420 rcu_assign_pointer(tun->tfiles[index],
421 tun->tfiles[tun->numqueues - 1]);
422 ntfile = rtnl_dereference(tun->tfiles[index]);
423 ntfile->queue_index = index;
424
425 --tun->numqueues;
426 if (clean) {
427 rcu_assign_pointer(tfile->tun, NULL);
428 sock_put(&tfile->sk);
429 } else
430 tun_disable_queue(tun, tfile);
431
432 synchronize_net();
433 tun_flow_delete_by_queue(tun, tun->numqueues + 1);
434 /* Drop read queue */
435 skb_queue_purge(&tfile->sk.sk_receive_queue);
436 tun_set_real_num_queues(tun);
437 } else if (tfile->detached && clean) {
438 tun = tun_enable_queue(tfile);
439 sock_put(&tfile->sk);
440 }
441
442 if (clean) {
443 if (tun && tun->numqueues == 0 && tun->numdisabled == 0) {
444 netif_carrier_off(tun->dev);
445
446 if (!(tun->flags & TUN_PERSIST) &&
447 tun->dev->reg_state == NETREG_REGISTERED)
448 unregister_netdevice(tun->dev);
449 }
450
451 BUG_ON(!test_bit(SOCK_EXTERNALLY_ALLOCATED,
452 &tfile->socket.flags));
453 sk_release_kernel(&tfile->sk);
454 }
455 }
456
457 static void tun_detach(struct tun_file *tfile, bool clean)
458 {
459 rtnl_lock();
460 __tun_detach(tfile, clean);
461 rtnl_unlock();
462 }
463
464 static void tun_detach_all(struct net_device *dev)
465 {
466 struct tun_struct *tun = netdev_priv(dev);
467 struct tun_file *tfile, *tmp;
468 int i, n = tun->numqueues;
469
470 for (i = 0; i < n; i++) {
471 tfile = rtnl_dereference(tun->tfiles[i]);
472 BUG_ON(!tfile);
473 wake_up_all(&tfile->wq.wait);
474 rcu_assign_pointer(tfile->tun, NULL);
475 --tun->numqueues;
476 }
477 list_for_each_entry(tfile, &tun->disabled, next) {
478 wake_up_all(&tfile->wq.wait);
479 rcu_assign_pointer(tfile->tun, NULL);
480 }
481 BUG_ON(tun->numqueues != 0);
482
483 synchronize_net();
484 for (i = 0; i < n; i++) {
485 tfile = rtnl_dereference(tun->tfiles[i]);
486 /* Drop read queue */
487 skb_queue_purge(&tfile->sk.sk_receive_queue);
488 sock_put(&tfile->sk);
489 }
490 list_for_each_entry_safe(tfile, tmp, &tun->disabled, next) {
491 tun_enable_queue(tfile);
492 skb_queue_purge(&tfile->sk.sk_receive_queue);
493 sock_put(&tfile->sk);
494 }
495 BUG_ON(tun->numdisabled != 0);
496
497 if (tun->flags & TUN_PERSIST)
498 module_put(THIS_MODULE);
499 }
500
501 static int tun_attach(struct tun_struct *tun, struct file *file)
502 {
503 struct tun_file *tfile = file->private_data;
504 int err;
505
506 err = security_tun_dev_attach(tfile->socket.sk, tun->security);
507 if (err < 0)
508 goto out;
509
510 err = -EINVAL;
511 if (rtnl_dereference(tfile->tun) && !tfile->detached)
512 goto out;
513
514 err = -EBUSY;
515 if (!(tun->flags & TUN_TAP_MQ) && tun->numqueues == 1)
516 goto out;
517
518 err = -E2BIG;
519 if (!tfile->detached &&
520 tun->numqueues + tun->numdisabled == MAX_TAP_QUEUES)
521 goto out;
522
523 err = 0;
524
525 /* Re-attach the filter to presist device */
526 if (tun->filter_attached == true) {
527 err = sk_attach_filter(&tun->fprog, tfile->socket.sk);
528 if (!err)
529 goto out;
530 }
531 tfile->queue_index = tun->numqueues;
532 rcu_assign_pointer(tfile->tun, tun);
533 rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile);
534 tun->numqueues++;
535
536 if (tfile->detached)
537 tun_enable_queue(tfile);
538 else
539 sock_hold(&tfile->sk);
540
541 tun_set_real_num_queues(tun);
542
543 /* device is allowed to go away first, so no need to hold extra
544 * refcnt.
545 */
546
547 out:
548 return err;
549 }
550
551 static struct tun_struct *__tun_get(struct tun_file *tfile)
552 {
553 struct tun_struct *tun;
554
555 rcu_read_lock();
556 tun = rcu_dereference(tfile->tun);
557 if (tun)
558 dev_hold(tun->dev);
559 rcu_read_unlock();
560
561 return tun;
562 }
563
564 static struct tun_struct *tun_get(struct file *file)
565 {
566 return __tun_get(file->private_data);
567 }
568
569 static void tun_put(struct tun_struct *tun)
570 {
571 dev_put(tun->dev);
572 }
573
574 /* TAP filtering */
575 static void addr_hash_set(u32 *mask, const u8 *addr)
576 {
577 int n = ether_crc(ETH_ALEN, addr) >> 26;
578 mask[n >> 5] |= (1 << (n & 31));
579 }
580
581 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
582 {
583 int n = ether_crc(ETH_ALEN, addr) >> 26;
584 return mask[n >> 5] & (1 << (n & 31));
585 }
586
587 static int update_filter(struct tap_filter *filter, void __user *arg)
588 {
589 struct { u8 u[ETH_ALEN]; } *addr;
590 struct tun_filter uf;
591 int err, alen, n, nexact;
592
593 if (copy_from_user(&uf, arg, sizeof(uf)))
594 return -EFAULT;
595
596 if (!uf.count) {
597 /* Disabled */
598 filter->count = 0;
599 return 0;
600 }
601
602 alen = ETH_ALEN * uf.count;
603 addr = kmalloc(alen, GFP_KERNEL);
604 if (!addr)
605 return -ENOMEM;
606
607 if (copy_from_user(addr, arg + sizeof(uf), alen)) {
608 err = -EFAULT;
609 goto done;
610 }
611
612 /* The filter is updated without holding any locks. Which is
613 * perfectly safe. We disable it first and in the worst
614 * case we'll accept a few undesired packets. */
615 filter->count = 0;
616 wmb();
617
618 /* Use first set of addresses as an exact filter */
619 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
620 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
621
622 nexact = n;
623
624 /* Remaining multicast addresses are hashed,
625 * unicast will leave the filter disabled. */
626 memset(filter->mask, 0, sizeof(filter->mask));
627 for (; n < uf.count; n++) {
628 if (!is_multicast_ether_addr(addr[n].u)) {
629 err = 0; /* no filter */
630 goto done;
631 }
632 addr_hash_set(filter->mask, addr[n].u);
633 }
634
635 /* For ALLMULTI just set the mask to all ones.
636 * This overrides the mask populated above. */
637 if ((uf.flags & TUN_FLT_ALLMULTI))
638 memset(filter->mask, ~0, sizeof(filter->mask));
639
640 /* Now enable the filter */
641 wmb();
642 filter->count = nexact;
643
644 /* Return the number of exact filters */
645 err = nexact;
646
647 done:
648 kfree(addr);
649 return err;
650 }
651
652 /* Returns: 0 - drop, !=0 - accept */
653 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
654 {
655 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
656 * at this point. */
657 struct ethhdr *eh = (struct ethhdr *) skb->data;
658 int i;
659
660 /* Exact match */
661 for (i = 0; i < filter->count; i++)
662 if (ether_addr_equal(eh->h_dest, filter->addr[i]))
663 return 1;
664
665 /* Inexact match (multicast only) */
666 if (is_multicast_ether_addr(eh->h_dest))
667 return addr_hash_test(filter->mask, eh->h_dest);
668
669 return 0;
670 }
671
672 /*
673 * Checks whether the packet is accepted or not.
674 * Returns: 0 - drop, !=0 - accept
675 */
676 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
677 {
678 if (!filter->count)
679 return 1;
680
681 return run_filter(filter, skb);
682 }
683
684 /* Network device part of the driver */
685
686 static const struct ethtool_ops tun_ethtool_ops;
687
688 /* Net device detach from fd. */
689 static void tun_net_uninit(struct net_device *dev)
690 {
691 tun_detach_all(dev);
692 }
693
694 /* Net device open. */
695 static int tun_net_open(struct net_device *dev)
696 {
697 netif_tx_start_all_queues(dev);
698 return 0;
699 }
700
701 /* Net device close. */
702 static int tun_net_close(struct net_device *dev)
703 {
704 netif_tx_stop_all_queues(dev);
705 return 0;
706 }
707
708 /* Net device start xmit */
709 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
710 {
711 struct tun_struct *tun = netdev_priv(dev);
712 int txq = skb->queue_mapping;
713 struct tun_file *tfile;
714
715 rcu_read_lock();
716 tfile = rcu_dereference(tun->tfiles[txq]);
717
718 /* Drop packet if interface is not attached */
719 if (txq >= tun->numqueues)
720 goto drop;
721
722 tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len);
723
724 BUG_ON(!tfile);
725
726 /* Drop if the filter does not like it.
727 * This is a noop if the filter is disabled.
728 * Filter can be enabled only for the TAP devices. */
729 if (!check_filter(&tun->txflt, skb))
730 goto drop;
731
732 if (tfile->socket.sk->sk_filter &&
733 sk_filter(tfile->socket.sk, skb))
734 goto drop;
735
736 /* Limit the number of packets queued by dividing txq length with the
737 * number of queues.
738 */
739 if (skb_queue_len(&tfile->socket.sk->sk_receive_queue)
740 >= dev->tx_queue_len / tun->numqueues)
741 goto drop;
742
743 if (skb->sk) {
744 sock_tx_timestamp(skb->sk, &skb_shinfo(skb)->tx_flags);
745 sw_tx_timestamp(skb);
746 }
747
748 /* Orphan the skb - required as we might hang on to it
749 * for indefinite time. */
750 if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
751 goto drop;
752 skb_orphan(skb);
753
754 nf_reset(skb);
755
756 /* Enqueue packet */
757 skb_queue_tail(&tfile->socket.sk->sk_receive_queue, skb);
758
759 /* Notify and wake up reader process */
760 if (tfile->flags & TUN_FASYNC)
761 kill_fasync(&tfile->fasync, SIGIO, POLL_IN);
762 wake_up_interruptible_poll(&tfile->wq.wait, POLLIN |
763 POLLRDNORM | POLLRDBAND);
764
765 rcu_read_unlock();
766 return NETDEV_TX_OK;
767
768 drop:
769 dev->stats.tx_dropped++;
770 skb_tx_error(skb);
771 kfree_skb(skb);
772 rcu_read_unlock();
773 return NETDEV_TX_OK;
774 }
775
776 static void tun_net_mclist(struct net_device *dev)
777 {
778 /*
779 * This callback is supposed to deal with mc filter in
780 * _rx_ path and has nothing to do with the _tx_ path.
781 * In rx path we always accept everything userspace gives us.
782 */
783 }
784
785 #define MIN_MTU 68
786 #define MAX_MTU 65535
787
788 static int
789 tun_net_change_mtu(struct net_device *dev, int new_mtu)
790 {
791 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
792 return -EINVAL;
793 dev->mtu = new_mtu;
794 return 0;
795 }
796
797 static netdev_features_t tun_net_fix_features(struct net_device *dev,
798 netdev_features_t features)
799 {
800 struct tun_struct *tun = netdev_priv(dev);
801
802 return (features & tun->set_features) | (features & ~TUN_USER_FEATURES);
803 }
804 #ifdef CONFIG_NET_POLL_CONTROLLER
805 static void tun_poll_controller(struct net_device *dev)
806 {
807 /*
808 * Tun only receives frames when:
809 * 1) the char device endpoint gets data from user space
810 * 2) the tun socket gets a sendmsg call from user space
811 * Since both of those are syncronous operations, we are guaranteed
812 * never to have pending data when we poll for it
813 * so theres nothing to do here but return.
814 * We need this though so netpoll recognizes us as an interface that
815 * supports polling, which enables bridge devices in virt setups to
816 * still use netconsole
817 */
818 return;
819 }
820 #endif
821 static const struct net_device_ops tun_netdev_ops = {
822 .ndo_uninit = tun_net_uninit,
823 .ndo_open = tun_net_open,
824 .ndo_stop = tun_net_close,
825 .ndo_start_xmit = tun_net_xmit,
826 .ndo_change_mtu = tun_net_change_mtu,
827 .ndo_fix_features = tun_net_fix_features,
828 .ndo_select_queue = tun_select_queue,
829 #ifdef CONFIG_NET_POLL_CONTROLLER
830 .ndo_poll_controller = tun_poll_controller,
831 #endif
832 };
833
834 static const struct net_device_ops tap_netdev_ops = {
835 .ndo_uninit = tun_net_uninit,
836 .ndo_open = tun_net_open,
837 .ndo_stop = tun_net_close,
838 .ndo_start_xmit = tun_net_xmit,
839 .ndo_change_mtu = tun_net_change_mtu,
840 .ndo_fix_features = tun_net_fix_features,
841 .ndo_set_rx_mode = tun_net_mclist,
842 .ndo_set_mac_address = eth_mac_addr,
843 .ndo_validate_addr = eth_validate_addr,
844 .ndo_select_queue = tun_select_queue,
845 #ifdef CONFIG_NET_POLL_CONTROLLER
846 .ndo_poll_controller = tun_poll_controller,
847 #endif
848 };
849
850 static void tun_flow_init(struct tun_struct *tun)
851 {
852 int i;
853
854 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++)
855 INIT_HLIST_HEAD(&tun->flows[i]);
856
857 tun->ageing_time = TUN_FLOW_EXPIRE;
858 setup_timer(&tun->flow_gc_timer, tun_flow_cleanup, (unsigned long)tun);
859 mod_timer(&tun->flow_gc_timer,
860 round_jiffies_up(jiffies + tun->ageing_time));
861 }
862
863 static void tun_flow_uninit(struct tun_struct *tun)
864 {
865 del_timer_sync(&tun->flow_gc_timer);
866 tun_flow_flush(tun);
867 }
868
869 /* Initialize net device. */
870 static void tun_net_init(struct net_device *dev)
871 {
872 struct tun_struct *tun = netdev_priv(dev);
873
874 switch (tun->flags & TUN_TYPE_MASK) {
875 case TUN_TUN_DEV:
876 dev->netdev_ops = &tun_netdev_ops;
877
878 /* Point-to-Point TUN Device */
879 dev->hard_header_len = 0;
880 dev->addr_len = 0;
881 dev->mtu = 1500;
882
883 /* Zero header length */
884 dev->type = ARPHRD_NONE;
885 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
886 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
887 break;
888
889 case TUN_TAP_DEV:
890 dev->netdev_ops = &tap_netdev_ops;
891 /* Ethernet TAP Device */
892 ether_setup(dev);
893 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
894 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
895
896 eth_hw_addr_random(dev);
897
898 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
899 break;
900 }
901 }
902
903 /* Character device part */
904
905 /* Poll */
906 static unsigned int tun_chr_poll(struct file *file, poll_table *wait)
907 {
908 struct tun_file *tfile = file->private_data;
909 struct tun_struct *tun = __tun_get(tfile);
910 struct sock *sk;
911 unsigned int mask = 0;
912
913 if (!tun)
914 return POLLERR;
915
916 sk = tfile->socket.sk;
917
918 tun_debug(KERN_INFO, tun, "tun_chr_poll\n");
919
920 poll_wait(file, &tfile->wq.wait, wait);
921
922 if (!skb_queue_empty(&sk->sk_receive_queue))
923 mask |= POLLIN | POLLRDNORM;
924
925 if (sock_writeable(sk) ||
926 (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
927 sock_writeable(sk)))
928 mask |= POLLOUT | POLLWRNORM;
929
930 if (tun->dev->reg_state != NETREG_REGISTERED)
931 mask = POLLERR;
932
933 tun_put(tun);
934 return mask;
935 }
936
937 /* prepad is the amount to reserve at front. len is length after that.
938 * linear is a hint as to how much to copy (usually headers). */
939 static struct sk_buff *tun_alloc_skb(struct tun_file *tfile,
940 size_t prepad, size_t len,
941 size_t linear, int noblock)
942 {
943 struct sock *sk = tfile->socket.sk;
944 struct sk_buff *skb;
945 int err;
946
947 /* Under a page? Don't bother with paged skb. */
948 if (prepad + len < PAGE_SIZE || !linear)
949 linear = len;
950
951 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
952 &err);
953 if (!skb)
954 return ERR_PTR(err);
955
956 skb_reserve(skb, prepad);
957 skb_put(skb, linear);
958 skb->data_len = len - linear;
959 skb->len += len - linear;
960
961 return skb;
962 }
963
964 /* set skb frags from iovec, this can move to core network code for reuse */
965 static int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *from,
966 int offset, size_t count)
967 {
968 int len = iov_length(from, count) - offset;
969 int copy = skb_headlen(skb);
970 int size, offset1 = 0;
971 int i = 0;
972
973 /* Skip over from offset */
974 while (count && (offset >= from->iov_len)) {
975 offset -= from->iov_len;
976 ++from;
977 --count;
978 }
979
980 /* copy up to skb headlen */
981 while (count && (copy > 0)) {
982 size = min_t(unsigned int, copy, from->iov_len - offset);
983 if (copy_from_user(skb->data + offset1, from->iov_base + offset,
984 size))
985 return -EFAULT;
986 if (copy > size) {
987 ++from;
988 --count;
989 offset = 0;
990 } else
991 offset += size;
992 copy -= size;
993 offset1 += size;
994 }
995
996 if (len == offset1)
997 return 0;
998
999 while (count--) {
1000 struct page *page[MAX_SKB_FRAGS];
1001 int num_pages;
1002 unsigned long base;
1003 unsigned long truesize;
1004
1005 len = from->iov_len - offset;
1006 if (!len) {
1007 offset = 0;
1008 ++from;
1009 continue;
1010 }
1011 base = (unsigned long)from->iov_base + offset;
1012 size = ((base & ~PAGE_MASK) + len + ~PAGE_MASK) >> PAGE_SHIFT;
1013 if (i + size > MAX_SKB_FRAGS)
1014 return -EMSGSIZE;
1015 num_pages = get_user_pages_fast(base, size, 0, &page[i]);
1016 if (num_pages != size) {
1017 int j;
1018
1019 for (j = 0; j < num_pages; j++)
1020 put_page(page[i + j]);
1021 return -EFAULT;
1022 }
1023 truesize = size * PAGE_SIZE;
1024 skb->data_len += len;
1025 skb->len += len;
1026 skb->truesize += truesize;
1027 atomic_add(truesize, &skb->sk->sk_wmem_alloc);
1028 while (len) {
1029 int off = base & ~PAGE_MASK;
1030 int size = min_t(int, len, PAGE_SIZE - off);
1031 __skb_fill_page_desc(skb, i, page[i], off, size);
1032 skb_shinfo(skb)->nr_frags++;
1033 /* increase sk_wmem_alloc */
1034 base += size;
1035 len -= size;
1036 i++;
1037 }
1038 offset = 0;
1039 ++from;
1040 }
1041 return 0;
1042 }
1043
1044 static unsigned long iov_pages(const struct iovec *iv, int offset,
1045 unsigned long nr_segs)
1046 {
1047 unsigned long seg, base;
1048 int pages = 0, len, size;
1049
1050 while (nr_segs && (offset >= iv->iov_len)) {
1051 offset -= iv->iov_len;
1052 ++iv;
1053 --nr_segs;
1054 }
1055
1056 for (seg = 0; seg < nr_segs; seg++) {
1057 base = (unsigned long)iv[seg].iov_base + offset;
1058 len = iv[seg].iov_len - offset;
1059 size = ((base & ~PAGE_MASK) + len + ~PAGE_MASK) >> PAGE_SHIFT;
1060 pages += size;
1061 offset = 0;
1062 }
1063
1064 return pages;
1065 }
1066
1067 /* Get packet from user space buffer */
1068 static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
1069 void *msg_control, const struct iovec *iv,
1070 size_t total_len, size_t count, int noblock)
1071 {
1072 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
1073 struct sk_buff *skb;
1074 size_t len = total_len, align = NET_SKB_PAD, linear;
1075 struct virtio_net_hdr gso = { 0 };
1076 int offset = 0;
1077 int copylen;
1078 bool zerocopy = false;
1079 int err;
1080 u32 rxhash;
1081
1082 if (!(tun->flags & TUN_NO_PI)) {
1083 if ((len -= sizeof(pi)) > total_len)
1084 return -EINVAL;
1085
1086 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
1087 return -EFAULT;
1088 offset += sizeof(pi);
1089 }
1090
1091 if (tun->flags & TUN_VNET_HDR) {
1092 if ((len -= tun->vnet_hdr_sz) > total_len)
1093 return -EINVAL;
1094
1095 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
1096 return -EFAULT;
1097
1098 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
1099 gso.csum_start + gso.csum_offset + 2 > gso.hdr_len)
1100 gso.hdr_len = gso.csum_start + gso.csum_offset + 2;
1101
1102 if (gso.hdr_len > len)
1103 return -EINVAL;
1104 offset += tun->vnet_hdr_sz;
1105 }
1106
1107 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
1108 align += NET_IP_ALIGN;
1109 if (unlikely(len < ETH_HLEN ||
1110 (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
1111 return -EINVAL;
1112 }
1113
1114 if (msg_control) {
1115 /* There are 256 bytes to be copied in skb, so there is
1116 * enough room for skb expand head in case it is used.
1117 * The rest of the buffer is mapped from userspace.
1118 */
1119 copylen = gso.hdr_len ? gso.hdr_len : GOODCOPY_LEN;
1120 linear = copylen;
1121 if (iov_pages(iv, offset + copylen, count) <= MAX_SKB_FRAGS)
1122 zerocopy = true;
1123 }
1124
1125 if (!zerocopy) {
1126 copylen = len;
1127 linear = gso.hdr_len;
1128 }
1129
1130 skb = tun_alloc_skb(tfile, align, copylen, linear, noblock);
1131 if (IS_ERR(skb)) {
1132 if (PTR_ERR(skb) != -EAGAIN)
1133 tun->dev->stats.rx_dropped++;
1134 return PTR_ERR(skb);
1135 }
1136
1137 if (zerocopy)
1138 err = zerocopy_sg_from_iovec(skb, iv, offset, count);
1139 else {
1140 err = skb_copy_datagram_from_iovec(skb, 0, iv, offset, len);
1141 if (!err && msg_control) {
1142 struct ubuf_info *uarg = msg_control;
1143 uarg->callback(uarg, false);
1144 }
1145 }
1146
1147 if (err) {
1148 tun->dev->stats.rx_dropped++;
1149 kfree_skb(skb);
1150 return -EFAULT;
1151 }
1152
1153 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
1154 if (!skb_partial_csum_set(skb, gso.csum_start,
1155 gso.csum_offset)) {
1156 tun->dev->stats.rx_frame_errors++;
1157 kfree_skb(skb);
1158 return -EINVAL;
1159 }
1160 }
1161
1162 switch (tun->flags & TUN_TYPE_MASK) {
1163 case TUN_TUN_DEV:
1164 if (tun->flags & TUN_NO_PI) {
1165 switch (skb->data[0] & 0xf0) {
1166 case 0x40:
1167 pi.proto = htons(ETH_P_IP);
1168 break;
1169 case 0x60:
1170 pi.proto = htons(ETH_P_IPV6);
1171 break;
1172 default:
1173 tun->dev->stats.rx_dropped++;
1174 kfree_skb(skb);
1175 return -EINVAL;
1176 }
1177 }
1178
1179 skb_reset_mac_header(skb);
1180 skb->protocol = pi.proto;
1181 skb->dev = tun->dev;
1182 break;
1183 case TUN_TAP_DEV:
1184 skb->protocol = eth_type_trans(skb, tun->dev);
1185 break;
1186 }
1187
1188 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
1189 pr_debug("GSO!\n");
1190 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
1191 case VIRTIO_NET_HDR_GSO_TCPV4:
1192 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
1193 break;
1194 case VIRTIO_NET_HDR_GSO_TCPV6:
1195 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
1196 break;
1197 case VIRTIO_NET_HDR_GSO_UDP:
1198 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
1199 break;
1200 default:
1201 tun->dev->stats.rx_frame_errors++;
1202 kfree_skb(skb);
1203 return -EINVAL;
1204 }
1205
1206 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
1207 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
1208
1209 skb_shinfo(skb)->gso_size = gso.gso_size;
1210 if (skb_shinfo(skb)->gso_size == 0) {
1211 tun->dev->stats.rx_frame_errors++;
1212 kfree_skb(skb);
1213 return -EINVAL;
1214 }
1215
1216 /* Header must be checked, and gso_segs computed. */
1217 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
1218 skb_shinfo(skb)->gso_segs = 0;
1219 }
1220
1221 /* copy skb_ubuf_info for callback when skb has no error */
1222 if (zerocopy) {
1223 skb_shinfo(skb)->destructor_arg = msg_control;
1224 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1225 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
1226 }
1227
1228 skb_reset_network_header(skb);
1229 skb_probe_transport_header(skb, 0);
1230
1231 rxhash = skb_get_rxhash(skb);
1232 netif_rx_ni(skb);
1233
1234 tun->dev->stats.rx_packets++;
1235 tun->dev->stats.rx_bytes += len;
1236
1237 tun_flow_update(tun, rxhash, tfile);
1238 return total_len;
1239 }
1240
1241 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
1242 unsigned long count, loff_t pos)
1243 {
1244 struct file *file = iocb->ki_filp;
1245 struct tun_struct *tun = tun_get(file);
1246 struct tun_file *tfile = file->private_data;
1247 ssize_t result;
1248
1249 if (!tun)
1250 return -EBADFD;
1251
1252 tun_debug(KERN_INFO, tun, "tun_chr_write %ld\n", count);
1253
1254 result = tun_get_user(tun, tfile, NULL, iv, iov_length(iv, count),
1255 count, file->f_flags & O_NONBLOCK);
1256
1257 tun_put(tun);
1258 return result;
1259 }
1260
1261 /* Put packet to the user space buffer */
1262 static ssize_t tun_put_user(struct tun_struct *tun,
1263 struct tun_file *tfile,
1264 struct sk_buff *skb,
1265 const struct iovec *iv, int len)
1266 {
1267 struct tun_pi pi = { 0, skb->protocol };
1268 ssize_t total = 0;
1269 int vlan_offset = 0;
1270
1271 if (!(tun->flags & TUN_NO_PI)) {
1272 if ((len -= sizeof(pi)) < 0)
1273 return -EINVAL;
1274
1275 if (len < skb->len) {
1276 /* Packet will be striped */
1277 pi.flags |= TUN_PKT_STRIP;
1278 }
1279
1280 if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi)))
1281 return -EFAULT;
1282 total += sizeof(pi);
1283 }
1284
1285 if (tun->flags & TUN_VNET_HDR) {
1286 struct virtio_net_hdr gso = { 0 }; /* no info leak */
1287 if ((len -= tun->vnet_hdr_sz) < 0)
1288 return -EINVAL;
1289
1290 if (skb_is_gso(skb)) {
1291 struct skb_shared_info *sinfo = skb_shinfo(skb);
1292
1293 /* This is a hint as to how much should be linear. */
1294 gso.hdr_len = skb_headlen(skb);
1295 gso.gso_size = sinfo->gso_size;
1296 if (sinfo->gso_type & SKB_GSO_TCPV4)
1297 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
1298 else if (sinfo->gso_type & SKB_GSO_TCPV6)
1299 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
1300 else if (sinfo->gso_type & SKB_GSO_UDP)
1301 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
1302 else {
1303 pr_err("unexpected GSO type: "
1304 "0x%x, gso_size %d, hdr_len %d\n",
1305 sinfo->gso_type, gso.gso_size,
1306 gso.hdr_len);
1307 print_hex_dump(KERN_ERR, "tun: ",
1308 DUMP_PREFIX_NONE,
1309 16, 1, skb->head,
1310 min((int)gso.hdr_len, 64), true);
1311 WARN_ON_ONCE(1);
1312 return -EINVAL;
1313 }
1314 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
1315 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
1316 } else
1317 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
1318
1319 if (skb->ip_summed == CHECKSUM_PARTIAL) {
1320 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
1321 gso.csum_start = skb_checksum_start_offset(skb);
1322 gso.csum_offset = skb->csum_offset;
1323 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
1324 gso.flags = VIRTIO_NET_HDR_F_DATA_VALID;
1325 } /* else everything is zero */
1326
1327 if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
1328 sizeof(gso))))
1329 return -EFAULT;
1330 total += tun->vnet_hdr_sz;
1331 }
1332
1333 if (!vlan_tx_tag_present(skb)) {
1334 len = min_t(int, skb->len, len);
1335 } else {
1336 int copy, ret;
1337 struct {
1338 __be16 h_vlan_proto;
1339 __be16 h_vlan_TCI;
1340 } veth;
1341
1342 veth.h_vlan_proto = skb->vlan_proto;
1343 veth.h_vlan_TCI = htons(vlan_tx_tag_get(skb));
1344
1345 vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);
1346 len = min_t(int, skb->len + VLAN_HLEN, len);
1347
1348 copy = min_t(int, vlan_offset, len);
1349 ret = skb_copy_datagram_const_iovec(skb, 0, iv, total, copy);
1350 len -= copy;
1351 total += copy;
1352 if (ret || !len)
1353 goto done;
1354
1355 copy = min_t(int, sizeof(veth), len);
1356 ret = memcpy_toiovecend(iv, (void *)&veth, total, copy);
1357 len -= copy;
1358 total += copy;
1359 if (ret || !len)
1360 goto done;
1361 }
1362
1363 skb_copy_datagram_const_iovec(skb, vlan_offset, iv, total, len);
1364 total += len;
1365
1366 done:
1367 tun->dev->stats.tx_packets++;
1368 tun->dev->stats.tx_bytes += len;
1369
1370 return total;
1371 }
1372
1373 static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
1374 struct kiocb *iocb, const struct iovec *iv,
1375 ssize_t len, int noblock)
1376 {
1377 DECLARE_WAITQUEUE(wait, current);
1378 struct sk_buff *skb;
1379 ssize_t ret = 0;
1380
1381 tun_debug(KERN_INFO, tun, "tun_do_read\n");
1382
1383 if (unlikely(!noblock))
1384 add_wait_queue(&tfile->wq.wait, &wait);
1385 while (len) {
1386 current->state = TASK_INTERRUPTIBLE;
1387
1388 /* Read frames from the queue */
1389 if (!(skb = skb_dequeue(&tfile->socket.sk->sk_receive_queue))) {
1390 if (noblock) {
1391 ret = -EAGAIN;
1392 break;
1393 }
1394 if (signal_pending(current)) {
1395 ret = -ERESTARTSYS;
1396 break;
1397 }
1398 if (tun->dev->reg_state != NETREG_REGISTERED) {
1399 ret = -EIO;
1400 break;
1401 }
1402
1403 /* Nothing to read, let's sleep */
1404 schedule();
1405 continue;
1406 }
1407
1408 ret = tun_put_user(tun, tfile, skb, iv, len);
1409 kfree_skb(skb);
1410 break;
1411 }
1412
1413 current->state = TASK_RUNNING;
1414 if (unlikely(!noblock))
1415 remove_wait_queue(&tfile->wq.wait, &wait);
1416
1417 return ret;
1418 }
1419
1420 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
1421 unsigned long count, loff_t pos)
1422 {
1423 struct file *file = iocb->ki_filp;
1424 struct tun_file *tfile = file->private_data;
1425 struct tun_struct *tun = __tun_get(tfile);
1426 ssize_t len, ret;
1427
1428 if (!tun)
1429 return -EBADFD;
1430 len = iov_length(iv, count);
1431 if (len < 0) {
1432 ret = -EINVAL;
1433 goto out;
1434 }
1435
1436 ret = tun_do_read(tun, tfile, iocb, iv, len,
1437 file->f_flags & O_NONBLOCK);
1438 ret = min_t(ssize_t, ret, len);
1439 out:
1440 tun_put(tun);
1441 return ret;
1442 }
1443
1444 static void tun_free_netdev(struct net_device *dev)
1445 {
1446 struct tun_struct *tun = netdev_priv(dev);
1447
1448 BUG_ON(!(list_empty(&tun->disabled)));
1449 tun_flow_uninit(tun);
1450 security_tun_dev_free_security(tun->security);
1451 free_netdev(dev);
1452 }
1453
1454 static void tun_setup(struct net_device *dev)
1455 {
1456 struct tun_struct *tun = netdev_priv(dev);
1457
1458 tun->owner = INVALID_UID;
1459 tun->group = INVALID_GID;
1460
1461 dev->ethtool_ops = &tun_ethtool_ops;
1462 dev->destructor = tun_free_netdev;
1463 }
1464
1465 /* Trivial set of netlink ops to allow deleting tun or tap
1466 * device with netlink.
1467 */
1468 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
1469 {
1470 return -EINVAL;
1471 }
1472
1473 static struct rtnl_link_ops tun_link_ops __read_mostly = {
1474 .kind = DRV_NAME,
1475 .priv_size = sizeof(struct tun_struct),
1476 .setup = tun_setup,
1477 .validate = tun_validate,
1478 };
1479
1480 static void tun_sock_write_space(struct sock *sk)
1481 {
1482 struct tun_file *tfile;
1483 wait_queue_head_t *wqueue;
1484
1485 if (!sock_writeable(sk))
1486 return;
1487
1488 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
1489 return;
1490
1491 wqueue = sk_sleep(sk);
1492 if (wqueue && waitqueue_active(wqueue))
1493 wake_up_interruptible_sync_poll(wqueue, POLLOUT |
1494 POLLWRNORM | POLLWRBAND);
1495
1496 tfile = container_of(sk, struct tun_file, sk);
1497 kill_fasync(&tfile->fasync, SIGIO, POLL_OUT);
1498 }
1499
1500 static int tun_sendmsg(struct kiocb *iocb, struct socket *sock,
1501 struct msghdr *m, size_t total_len)
1502 {
1503 int ret;
1504 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1505 struct tun_struct *tun = __tun_get(tfile);
1506
1507 if (!tun)
1508 return -EBADFD;
1509 ret = tun_get_user(tun, tfile, m->msg_control, m->msg_iov, total_len,
1510 m->msg_iovlen, m->msg_flags & MSG_DONTWAIT);
1511 tun_put(tun);
1512 return ret;
1513 }
1514
1515 static int tun_recvmsg(struct kiocb *iocb, struct socket *sock,
1516 struct msghdr *m, size_t total_len,
1517 int flags)
1518 {
1519 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1520 struct tun_struct *tun = __tun_get(tfile);
1521 int ret;
1522
1523 if (!tun)
1524 return -EBADFD;
1525
1526 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC|MSG_ERRQUEUE)) {
1527 ret = -EINVAL;
1528 goto out;
1529 }
1530 if (flags & MSG_ERRQUEUE) {
1531 ret = sock_recv_errqueue(sock->sk, m, total_len,
1532 SOL_PACKET, TUN_TX_TIMESTAMP);
1533 goto out;
1534 }
1535 ret = tun_do_read(tun, tfile, iocb, m->msg_iov, total_len,
1536 flags & MSG_DONTWAIT);
1537 if (ret > total_len) {
1538 m->msg_flags |= MSG_TRUNC;
1539 ret = flags & MSG_TRUNC ? ret : total_len;
1540 }
1541 out:
1542 tun_put(tun);
1543 return ret;
1544 }
1545
1546 static int tun_release(struct socket *sock)
1547 {
1548 if (sock->sk)
1549 sock_put(sock->sk);
1550 return 0;
1551 }
1552
1553 /* Ops structure to mimic raw sockets with tun */
1554 static const struct proto_ops tun_socket_ops = {
1555 .sendmsg = tun_sendmsg,
1556 .recvmsg = tun_recvmsg,
1557 .release = tun_release,
1558 };
1559
1560 static struct proto tun_proto = {
1561 .name = "tun",
1562 .owner = THIS_MODULE,
1563 .obj_size = sizeof(struct tun_file),
1564 };
1565
1566 static int tun_flags(struct tun_struct *tun)
1567 {
1568 int flags = 0;
1569
1570 if (tun->flags & TUN_TUN_DEV)
1571 flags |= IFF_TUN;
1572 else
1573 flags |= IFF_TAP;
1574
1575 if (tun->flags & TUN_NO_PI)
1576 flags |= IFF_NO_PI;
1577
1578 /* This flag has no real effect. We track the value for backwards
1579 * compatibility.
1580 */
1581 if (tun->flags & TUN_ONE_QUEUE)
1582 flags |= IFF_ONE_QUEUE;
1583
1584 if (tun->flags & TUN_VNET_HDR)
1585 flags |= IFF_VNET_HDR;
1586
1587 if (tun->flags & TUN_TAP_MQ)
1588 flags |= IFF_MULTI_QUEUE;
1589
1590 if (tun->flags & TUN_PERSIST)
1591 flags |= IFF_PERSIST;
1592
1593 return flags;
1594 }
1595
1596 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
1597 char *buf)
1598 {
1599 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1600 return sprintf(buf, "0x%x\n", tun_flags(tun));
1601 }
1602
1603 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
1604 char *buf)
1605 {
1606 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1607 return uid_valid(tun->owner)?
1608 sprintf(buf, "%u\n",
1609 from_kuid_munged(current_user_ns(), tun->owner)):
1610 sprintf(buf, "-1\n");
1611 }
1612
1613 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
1614 char *buf)
1615 {
1616 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1617 return gid_valid(tun->group) ?
1618 sprintf(buf, "%u\n",
1619 from_kgid_munged(current_user_ns(), tun->group)):
1620 sprintf(buf, "-1\n");
1621 }
1622
1623 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
1624 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
1625 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
1626
1627 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
1628 {
1629 struct tun_struct *tun;
1630 struct tun_file *tfile = file->private_data;
1631 struct net_device *dev;
1632 int err;
1633
1634 if (tfile->detached)
1635 return -EINVAL;
1636
1637 dev = __dev_get_by_name(net, ifr->ifr_name);
1638 if (dev) {
1639 if (ifr->ifr_flags & IFF_TUN_EXCL)
1640 return -EBUSY;
1641 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
1642 tun = netdev_priv(dev);
1643 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
1644 tun = netdev_priv(dev);
1645 else
1646 return -EINVAL;
1647
1648 if (!!(ifr->ifr_flags & IFF_MULTI_QUEUE) !=
1649 !!(tun->flags & TUN_TAP_MQ))
1650 return -EINVAL;
1651
1652 if (tun_not_capable(tun))
1653 return -EPERM;
1654 err = security_tun_dev_open(tun->security);
1655 if (err < 0)
1656 return err;
1657
1658 err = tun_attach(tun, file);
1659 if (err < 0)
1660 return err;
1661
1662 if (tun->flags & TUN_TAP_MQ &&
1663 (tun->numqueues + tun->numdisabled > 1)) {
1664 /* One or more queue has already been attached, no need
1665 * to initialize the device again.
1666 */
1667 return 0;
1668 }
1669 }
1670 else {
1671 char *name;
1672 unsigned long flags = 0;
1673 int queues = ifr->ifr_flags & IFF_MULTI_QUEUE ?
1674 MAX_TAP_QUEUES : 1;
1675
1676 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1677 return -EPERM;
1678 err = security_tun_dev_create();
1679 if (err < 0)
1680 return err;
1681
1682 /* Set dev type */
1683 if (ifr->ifr_flags & IFF_TUN) {
1684 /* TUN device */
1685 flags |= TUN_TUN_DEV;
1686 name = "tun%d";
1687 } else if (ifr->ifr_flags & IFF_TAP) {
1688 /* TAP device */
1689 flags |= TUN_TAP_DEV;
1690 name = "tap%d";
1691 } else
1692 return -EINVAL;
1693
1694 if (*ifr->ifr_name)
1695 name = ifr->ifr_name;
1696
1697 dev = alloc_netdev_mqs(sizeof(struct tun_struct), name,
1698 tun_setup, queues, queues);
1699
1700 if (!dev)
1701 return -ENOMEM;
1702
1703 dev_net_set(dev, net);
1704 dev->rtnl_link_ops = &tun_link_ops;
1705
1706 tun = netdev_priv(dev);
1707 tun->dev = dev;
1708 tun->flags = flags;
1709 tun->txflt.count = 0;
1710 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
1711
1712 tun->filter_attached = false;
1713 tun->sndbuf = tfile->socket.sk->sk_sndbuf;
1714
1715 spin_lock_init(&tun->lock);
1716
1717 err = security_tun_dev_alloc_security(&tun->security);
1718 if (err < 0)
1719 goto err_free_dev;
1720
1721 tun_net_init(dev);
1722 tun_flow_init(tun);
1723
1724 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
1725 TUN_USER_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
1726 NETIF_F_HW_VLAN_STAG_TX;
1727 dev->features = dev->hw_features;
1728 dev->vlan_features = dev->features;
1729
1730 INIT_LIST_HEAD(&tun->disabled);
1731 err = tun_attach(tun, file);
1732 if (err < 0)
1733 goto err_free_dev;
1734
1735 err = register_netdevice(tun->dev);
1736 if (err < 0)
1737 goto err_free_dev;
1738
1739 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
1740 device_create_file(&tun->dev->dev, &dev_attr_owner) ||
1741 device_create_file(&tun->dev->dev, &dev_attr_group))
1742 pr_err("Failed to create tun sysfs files\n");
1743 }
1744
1745 netif_carrier_on(tun->dev);
1746
1747 tun_debug(KERN_INFO, tun, "tun_set_iff\n");
1748
1749 if (ifr->ifr_flags & IFF_NO_PI)
1750 tun->flags |= TUN_NO_PI;
1751 else
1752 tun->flags &= ~TUN_NO_PI;
1753
1754 /* This flag has no real effect. We track the value for backwards
1755 * compatibility.
1756 */
1757 if (ifr->ifr_flags & IFF_ONE_QUEUE)
1758 tun->flags |= TUN_ONE_QUEUE;
1759 else
1760 tun->flags &= ~TUN_ONE_QUEUE;
1761
1762 if (ifr->ifr_flags & IFF_VNET_HDR)
1763 tun->flags |= TUN_VNET_HDR;
1764 else
1765 tun->flags &= ~TUN_VNET_HDR;
1766
1767 if (ifr->ifr_flags & IFF_MULTI_QUEUE)
1768 tun->flags |= TUN_TAP_MQ;
1769 else
1770 tun->flags &= ~TUN_TAP_MQ;
1771
1772 /* Make sure persistent devices do not get stuck in
1773 * xoff state.
1774 */
1775 if (netif_running(tun->dev))
1776 netif_tx_wake_all_queues(tun->dev);
1777
1778 strcpy(ifr->ifr_name, tun->dev->name);
1779 return 0;
1780
1781 err_free_dev:
1782 free_netdev(dev);
1783 return err;
1784 }
1785
1786 static void tun_get_iff(struct net *net, struct tun_struct *tun,
1787 struct ifreq *ifr)
1788 {
1789 tun_debug(KERN_INFO, tun, "tun_get_iff\n");
1790
1791 strcpy(ifr->ifr_name, tun->dev->name);
1792
1793 ifr->ifr_flags = tun_flags(tun);
1794
1795 }
1796
1797 /* This is like a cut-down ethtool ops, except done via tun fd so no
1798 * privs required. */
1799 static int set_offload(struct tun_struct *tun, unsigned long arg)
1800 {
1801 netdev_features_t features = 0;
1802
1803 if (arg & TUN_F_CSUM) {
1804 features |= NETIF_F_HW_CSUM;
1805 arg &= ~TUN_F_CSUM;
1806
1807 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1808 if (arg & TUN_F_TSO_ECN) {
1809 features |= NETIF_F_TSO_ECN;
1810 arg &= ~TUN_F_TSO_ECN;
1811 }
1812 if (arg & TUN_F_TSO4)
1813 features |= NETIF_F_TSO;
1814 if (arg & TUN_F_TSO6)
1815 features |= NETIF_F_TSO6;
1816 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1817 }
1818
1819 if (arg & TUN_F_UFO) {
1820 features |= NETIF_F_UFO;
1821 arg &= ~TUN_F_UFO;
1822 }
1823 }
1824
1825 /* This gives the user a way to test for new features in future by
1826 * trying to set them. */
1827 if (arg)
1828 return -EINVAL;
1829
1830 tun->set_features = features;
1831 netdev_update_features(tun->dev);
1832
1833 return 0;
1834 }
1835
1836 static void tun_detach_filter(struct tun_struct *tun, int n)
1837 {
1838 int i;
1839 struct tun_file *tfile;
1840
1841 for (i = 0; i < n; i++) {
1842 tfile = rtnl_dereference(tun->tfiles[i]);
1843 sk_detach_filter(tfile->socket.sk);
1844 }
1845
1846 tun->filter_attached = false;
1847 }
1848
1849 static int tun_attach_filter(struct tun_struct *tun)
1850 {
1851 int i, ret = 0;
1852 struct tun_file *tfile;
1853
1854 for (i = 0; i < tun->numqueues; i++) {
1855 tfile = rtnl_dereference(tun->tfiles[i]);
1856 ret = sk_attach_filter(&tun->fprog, tfile->socket.sk);
1857 if (ret) {
1858 tun_detach_filter(tun, i);
1859 return ret;
1860 }
1861 }
1862
1863 tun->filter_attached = true;
1864 return ret;
1865 }
1866
1867 static void tun_set_sndbuf(struct tun_struct *tun)
1868 {
1869 struct tun_file *tfile;
1870 int i;
1871
1872 for (i = 0; i < tun->numqueues; i++) {
1873 tfile = rtnl_dereference(tun->tfiles[i]);
1874 tfile->socket.sk->sk_sndbuf = tun->sndbuf;
1875 }
1876 }
1877
1878 static int tun_set_queue(struct file *file, struct ifreq *ifr)
1879 {
1880 struct tun_file *tfile = file->private_data;
1881 struct tun_struct *tun;
1882 int ret = 0;
1883
1884 rtnl_lock();
1885
1886 if (ifr->ifr_flags & IFF_ATTACH_QUEUE) {
1887 tun = tfile->detached;
1888 if (!tun) {
1889 ret = -EINVAL;
1890 goto unlock;
1891 }
1892 ret = security_tun_dev_attach_queue(tun->security);
1893 if (ret < 0)
1894 goto unlock;
1895 ret = tun_attach(tun, file);
1896 } else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
1897 tun = rtnl_dereference(tfile->tun);
1898 if (!tun || !(tun->flags & TUN_TAP_MQ) || tfile->detached)
1899 ret = -EINVAL;
1900 else
1901 __tun_detach(tfile, false);
1902 } else
1903 ret = -EINVAL;
1904
1905 unlock:
1906 rtnl_unlock();
1907 return ret;
1908 }
1909
1910 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
1911 unsigned long arg, int ifreq_len)
1912 {
1913 struct tun_file *tfile = file->private_data;
1914 struct tun_struct *tun;
1915 void __user* argp = (void __user*)arg;
1916 struct ifreq ifr;
1917 kuid_t owner;
1918 kgid_t group;
1919 int sndbuf;
1920 int vnet_hdr_sz;
1921 int ret;
1922
1923 if (cmd == TUNSETIFF || cmd == TUNSETQUEUE || _IOC_TYPE(cmd) == 0x89) {
1924 if (copy_from_user(&ifr, argp, ifreq_len))
1925 return -EFAULT;
1926 } else {
1927 memset(&ifr, 0, sizeof(ifr));
1928 }
1929 if (cmd == TUNGETFEATURES) {
1930 /* Currently this just means: "what IFF flags are valid?".
1931 * This is needed because we never checked for invalid flags on
1932 * TUNSETIFF. */
1933 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
1934 IFF_VNET_HDR | IFF_MULTI_QUEUE,
1935 (unsigned int __user*)argp);
1936 } else if (cmd == TUNSETQUEUE)
1937 return tun_set_queue(file, &ifr);
1938
1939 ret = 0;
1940 rtnl_lock();
1941
1942 tun = __tun_get(tfile);
1943 if (cmd == TUNSETIFF && !tun) {
1944 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1945
1946 ret = tun_set_iff(tfile->net, file, &ifr);
1947
1948 if (ret)
1949 goto unlock;
1950
1951 if (copy_to_user(argp, &ifr, ifreq_len))
1952 ret = -EFAULT;
1953 goto unlock;
1954 }
1955
1956 ret = -EBADFD;
1957 if (!tun)
1958 goto unlock;
1959
1960 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %u\n", cmd);
1961
1962 ret = 0;
1963 switch (cmd) {
1964 case TUNGETIFF:
1965 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1966
1967 if (copy_to_user(argp, &ifr, ifreq_len))
1968 ret = -EFAULT;
1969 break;
1970
1971 case TUNSETNOCSUM:
1972 /* Disable/Enable checksum */
1973
1974 /* [unimplemented] */
1975 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n",
1976 arg ? "disabled" : "enabled");
1977 break;
1978
1979 case TUNSETPERSIST:
1980 /* Disable/Enable persist mode. Keep an extra reference to the
1981 * module to prevent the module being unprobed.
1982 */
1983 if (arg && !(tun->flags & TUN_PERSIST)) {
1984 tun->flags |= TUN_PERSIST;
1985 __module_get(THIS_MODULE);
1986 }
1987 if (!arg && (tun->flags & TUN_PERSIST)) {
1988 tun->flags &= ~TUN_PERSIST;
1989 module_put(THIS_MODULE);
1990 }
1991
1992 tun_debug(KERN_INFO, tun, "persist %s\n",
1993 arg ? "enabled" : "disabled");
1994 break;
1995
1996 case TUNSETOWNER:
1997 /* Set owner of the device */
1998 owner = make_kuid(current_user_ns(), arg);
1999 if (!uid_valid(owner)) {
2000 ret = -EINVAL;
2001 break;
2002 }
2003 tun->owner = owner;
2004 tun_debug(KERN_INFO, tun, "owner set to %u\n",
2005 from_kuid(&init_user_ns, tun->owner));
2006 break;
2007
2008 case TUNSETGROUP:
2009 /* Set group of the device */
2010 group = make_kgid(current_user_ns(), arg);
2011 if (!gid_valid(group)) {
2012 ret = -EINVAL;
2013 break;
2014 }
2015 tun->group = group;
2016 tun_debug(KERN_INFO, tun, "group set to %u\n",
2017 from_kgid(&init_user_ns, tun->group));
2018 break;
2019
2020 case TUNSETLINK:
2021 /* Only allow setting the type when the interface is down */
2022 if (tun->dev->flags & IFF_UP) {
2023 tun_debug(KERN_INFO, tun,
2024 "Linktype set failed because interface is up\n");
2025 ret = -EBUSY;
2026 } else {
2027 tun->dev->type = (int) arg;
2028 tun_debug(KERN_INFO, tun, "linktype set to %d\n",
2029 tun->dev->type);
2030 ret = 0;
2031 }
2032 break;
2033
2034 #ifdef TUN_DEBUG
2035 case TUNSETDEBUG:
2036 tun->debug = arg;
2037 break;
2038 #endif
2039 case TUNSETOFFLOAD:
2040 ret = set_offload(tun, arg);
2041 break;
2042
2043 case TUNSETTXFILTER:
2044 /* Can be set only for TAPs */
2045 ret = -EINVAL;
2046 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
2047 break;
2048 ret = update_filter(&tun->txflt, (void __user *)arg);
2049 break;
2050
2051 case SIOCGIFHWADDR:
2052 /* Get hw address */
2053 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
2054 ifr.ifr_hwaddr.sa_family = tun->dev->type;
2055 if (copy_to_user(argp, &ifr, ifreq_len))
2056 ret = -EFAULT;
2057 break;
2058
2059 case SIOCSIFHWADDR:
2060 /* Set hw address */
2061 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
2062 ifr.ifr_hwaddr.sa_data);
2063
2064 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
2065 break;
2066
2067 case TUNGETSNDBUF:
2068 sndbuf = tfile->socket.sk->sk_sndbuf;
2069 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
2070 ret = -EFAULT;
2071 break;
2072
2073 case TUNSETSNDBUF:
2074 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
2075 ret = -EFAULT;
2076 break;
2077 }
2078
2079 tun->sndbuf = sndbuf;
2080 tun_set_sndbuf(tun);
2081 break;
2082
2083 case TUNGETVNETHDRSZ:
2084 vnet_hdr_sz = tun->vnet_hdr_sz;
2085 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
2086 ret = -EFAULT;
2087 break;
2088
2089 case TUNSETVNETHDRSZ:
2090 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
2091 ret = -EFAULT;
2092 break;
2093 }
2094 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
2095 ret = -EINVAL;
2096 break;
2097 }
2098
2099 tun->vnet_hdr_sz = vnet_hdr_sz;
2100 break;
2101
2102 case TUNATTACHFILTER:
2103 /* Can be set only for TAPs */
2104 ret = -EINVAL;
2105 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
2106 break;
2107 ret = -EFAULT;
2108 if (copy_from_user(&tun->fprog, argp, sizeof(tun->fprog)))
2109 break;
2110
2111 ret = tun_attach_filter(tun);
2112 break;
2113
2114 case TUNDETACHFILTER:
2115 /* Can be set only for TAPs */
2116 ret = -EINVAL;
2117 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
2118 break;
2119 ret = 0;
2120 tun_detach_filter(tun, tun->numqueues);
2121 break;
2122
2123 default:
2124 ret = -EINVAL;
2125 break;
2126 }
2127
2128 unlock:
2129 rtnl_unlock();
2130 if (tun)
2131 tun_put(tun);
2132 return ret;
2133 }
2134
2135 static long tun_chr_ioctl(struct file *file,
2136 unsigned int cmd, unsigned long arg)
2137 {
2138 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
2139 }
2140
2141 #ifdef CONFIG_COMPAT
2142 static long tun_chr_compat_ioctl(struct file *file,
2143 unsigned int cmd, unsigned long arg)
2144 {
2145 switch (cmd) {
2146 case TUNSETIFF:
2147 case TUNGETIFF:
2148 case TUNSETTXFILTER:
2149 case TUNGETSNDBUF:
2150 case TUNSETSNDBUF:
2151 case SIOCGIFHWADDR:
2152 case SIOCSIFHWADDR:
2153 arg = (unsigned long)compat_ptr(arg);
2154 break;
2155 default:
2156 arg = (compat_ulong_t)arg;
2157 break;
2158 }
2159
2160 /*
2161 * compat_ifreq is shorter than ifreq, so we must not access beyond
2162 * the end of that structure. All fields that are used in this
2163 * driver are compatible though, we don't need to convert the
2164 * contents.
2165 */
2166 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
2167 }
2168 #endif /* CONFIG_COMPAT */
2169
2170 static int tun_chr_fasync(int fd, struct file *file, int on)
2171 {
2172 struct tun_file *tfile = file->private_data;
2173 int ret;
2174
2175 if ((ret = fasync_helper(fd, file, on, &tfile->fasync)) < 0)
2176 goto out;
2177
2178 if (on) {
2179 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
2180 if (ret)
2181 goto out;
2182 tfile->flags |= TUN_FASYNC;
2183 } else
2184 tfile->flags &= ~TUN_FASYNC;
2185 ret = 0;
2186 out:
2187 return ret;
2188 }
2189
2190 static int tun_chr_open(struct inode *inode, struct file * file)
2191 {
2192 struct tun_file *tfile;
2193
2194 DBG1(KERN_INFO, "tunX: tun_chr_open\n");
2195
2196 tfile = (struct tun_file *)sk_alloc(&init_net, AF_UNSPEC, GFP_KERNEL,
2197 &tun_proto);
2198 if (!tfile)
2199 return -ENOMEM;
2200 rcu_assign_pointer(tfile->tun, NULL);
2201 tfile->net = get_net(current->nsproxy->net_ns);
2202 tfile->flags = 0;
2203
2204 rcu_assign_pointer(tfile->socket.wq, &tfile->wq);
2205 init_waitqueue_head(&tfile->wq.wait);
2206
2207 tfile->socket.file = file;
2208 tfile->socket.ops = &tun_socket_ops;
2209
2210 sock_init_data(&tfile->socket, &tfile->sk);
2211 sk_change_net(&tfile->sk, tfile->net);
2212
2213 tfile->sk.sk_write_space = tun_sock_write_space;
2214 tfile->sk.sk_sndbuf = INT_MAX;
2215
2216 file->private_data = tfile;
2217 set_bit(SOCK_EXTERNALLY_ALLOCATED, &tfile->socket.flags);
2218 INIT_LIST_HEAD(&tfile->next);
2219
2220 sock_set_flag(&tfile->sk, SOCK_ZEROCOPY);
2221
2222 return 0;
2223 }
2224
2225 static int tun_chr_close(struct inode *inode, struct file *file)
2226 {
2227 struct tun_file *tfile = file->private_data;
2228 struct net *net = tfile->net;
2229
2230 tun_detach(tfile, true);
2231 put_net(net);
2232
2233 return 0;
2234 }
2235
2236 static const struct file_operations tun_fops = {
2237 .owner = THIS_MODULE,
2238 .llseek = no_llseek,
2239 .read = do_sync_read,
2240 .aio_read = tun_chr_aio_read,
2241 .write = do_sync_write,
2242 .aio_write = tun_chr_aio_write,
2243 .poll = tun_chr_poll,
2244 .unlocked_ioctl = tun_chr_ioctl,
2245 #ifdef CONFIG_COMPAT
2246 .compat_ioctl = tun_chr_compat_ioctl,
2247 #endif
2248 .open = tun_chr_open,
2249 .release = tun_chr_close,
2250 .fasync = tun_chr_fasync
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 kernel - Deliverables
This page took 0.093268 seconds and 4 git commands to generate.