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Linux 4.1.16
[linux/fpc-iii.git] / drivers / net / tun.c
blobe470ae59d40536fe7530774cb473ebe57000f9a8
1 /*
2 * TUN - Universal TUN/TAP device driver.
3 * Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $
16 */
17
18 /*
19 * Changes:
20 *
21 * Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
22 * Add TUNSETLINK ioctl to set the link encapsulation
23 *
24 * Mark Smith <markzzzsmith@yahoo.com.au>
25 * Use eth_random_addr() for tap MAC address.
26 *
27 * Harald Roelle <harald.roelle@ifi.lmu.de> 2004/04/20
28 * Fixes in packet dropping, queue length setting and queue wakeup.
29 * Increased default tx queue length.
30 * Added ethtool API.
31 * Minor cleanups
32 *
33 * Daniel Podlejski <underley@underley.eu.org>
34 * Modifications for 2.3.99-pre5 kernel.
35 */
36
37 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
38
39 #define DRV_NAME "tun"
40 #define DRV_VERSION "1.6"
41 #define DRV_DESCRIPTION "Universal TUN/TAP device driver"
42 #define DRV_COPYRIGHT "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>"
43
44 #include <linux/module.h>
45 #include <linux/errno.h>
46 #include <linux/kernel.h>
47 #include <linux/major.h>
48 #include <linux/slab.h>
49 #include <linux/poll.h>
50 #include <linux/fcntl.h>
51 #include <linux/init.h>
52 #include <linux/skbuff.h>
53 #include <linux/netdevice.h>
54 #include <linux/etherdevice.h>
55 #include <linux/miscdevice.h>
56 #include <linux/ethtool.h>
57 #include <linux/rtnetlink.h>
58 #include <linux/compat.h>
59 #include <linux/if.h>
60 #include <linux/if_arp.h>
61 #include <linux/if_ether.h>
62 #include <linux/if_tun.h>
63 #include <linux/if_vlan.h>
64 #include <linux/crc32.h>
65 #include <linux/nsproxy.h>
66 #include <linux/virtio_net.h>
67 #include <linux/rcupdate.h>
68 #include <net/net_namespace.h>
69 #include <net/netns/generic.h>
70 #include <net/rtnetlink.h>
71 #include <net/sock.h>
72 #include <linux/seq_file.h>
73 #include <linux/uio.h>
74
75 #include <asm/uaccess.h>
76
77 /* Uncomment to enable debugging */
78 /* #define TUN_DEBUG 1 */
79
80 #ifdef TUN_DEBUG
81 static int debug;
82
83 #define tun_debug(level, tun, fmt, args...) \
84 do { \
85 if (tun->debug) \
86 netdev_printk(level, tun->dev, fmt, ##args); \
87 } while (0)
88 #define DBG1(level, fmt, args...) \
89 do { \
90 if (debug == 2) \
91 printk(level fmt, ##args); \
92 } while (0)
93 #else
94 #define tun_debug(level, tun, fmt, args...) \
95 do { \
96 if (0) \
97 netdev_printk(level, tun->dev, fmt, ##args); \
98 } while (0)
99 #define DBG1(level, fmt, args...) \
100 do { \
101 if (0) \
102 printk(level fmt, ##args); \
103 } while (0)
104 #endif
105
106 /* TUN device flags */
107
108 /* IFF_ATTACH_QUEUE is never stored in device flags,
109 * overload it to mean fasync when stored there.
110 */
111 #define TUN_FASYNC IFF_ATTACH_QUEUE
112 /* High bits in flags field are unused. */
113 #define TUN_VNET_LE 0x80000000
114
115 #define TUN_FEATURES (IFF_NO_PI | IFF_ONE_QUEUE | IFF_VNET_HDR | \
116 IFF_MULTI_QUEUE)
117 #define GOODCOPY_LEN 128
118
119 #define FLT_EXACT_COUNT 8
120 struct tap_filter {
121 unsigned int count; /* Number of addrs. Zero means disabled */
122 u32 mask[2]; /* Mask of the hashed addrs */
123 unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN];
124 };
125
126 /* MAX_TAP_QUEUES 256 is chosen to allow rx/tx queues to be equal
127 * to max number of VCPUs in guest. */
128 #define MAX_TAP_QUEUES 256
129 #define MAX_TAP_FLOWS 4096
130
131 #define TUN_FLOW_EXPIRE (3 * HZ)
132
133 /* A tun_file connects an open character device to a tuntap netdevice. It
134 * also contains all socket related structures (except sock_fprog and tap_filter)
135 * to serve as one transmit queue for tuntap device. The sock_fprog and
136 * tap_filter were kept in tun_struct since they were used for filtering for the
137 * netdevice not for a specific queue (at least I didn't see the requirement for
138 * this).
139 *
140 * RCU usage:
141 * The tun_file and tun_struct are loosely coupled, the pointer from one to the
142 * other can only be read while rcu_read_lock or rtnl_lock is held.
143 */
144 struct tun_file {
145 struct sock sk;
146 struct socket socket;
147 struct socket_wq wq;
148 struct tun_struct __rcu *tun;
149 struct net *net;
150 struct fasync_struct *fasync;
151 /* only used for fasnyc */
152 unsigned int flags;
153 union {
154 u16 queue_index;
155 unsigned int ifindex;
156 };
157 struct list_head next;
158 struct tun_struct *detached;
159 };
160
161 struct tun_flow_entry {
162 struct hlist_node hash_link;
163 struct rcu_head rcu;
164 struct tun_struct *tun;
165
166 u32 rxhash;
167 u32 rps_rxhash;
168 int queue_index;
169 unsigned long updated;
170 };
171
172 #define TUN_NUM_FLOW_ENTRIES 1024
173
174 /* Since the socket were moved to tun_file, to preserve the behavior of persist
175 * device, socket filter, sndbuf and vnet header size were restore when the
176 * file were attached to a persist device.
177 */
178 struct tun_struct {
179 struct tun_file __rcu *tfiles[MAX_TAP_QUEUES];
180 unsigned int numqueues;
181 unsigned int flags;
182 kuid_t owner;
183 kgid_t group;
184
185 struct net_device *dev;
186 netdev_features_t set_features;
187 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
188 NETIF_F_TSO6|NETIF_F_UFO)
189
190 int vnet_hdr_sz;
191 int sndbuf;
192 struct tap_filter txflt;
193 struct sock_fprog fprog;
194 /* protected by rtnl lock */
195 bool filter_attached;
196 #ifdef TUN_DEBUG
197 int debug;
198 #endif
199 spinlock_t lock;
200 struct hlist_head flows[TUN_NUM_FLOW_ENTRIES];
201 struct timer_list flow_gc_timer;
202 unsigned long ageing_time;
203 unsigned int numdisabled;
204 struct list_head disabled;
205 void *security;
206 u32 flow_count;
207 };
208
209 static inline u16 tun16_to_cpu(struct tun_struct *tun, __virtio16 val)
210 {
211 return __virtio16_to_cpu(tun->flags & TUN_VNET_LE, val);
212 }
213
214 static inline __virtio16 cpu_to_tun16(struct tun_struct *tun, u16 val)
215 {
216 return __cpu_to_virtio16(tun->flags & TUN_VNET_LE, val);
217 }
218
219 static inline u32 tun_hashfn(u32 rxhash)
220 {
221 return rxhash & 0x3ff;
222 }
223
224 static struct tun_flow_entry *tun_flow_find(struct hlist_head *head, u32 rxhash)
225 {
226 struct tun_flow_entry *e;
227
228 hlist_for_each_entry_rcu(e, head, hash_link) {
229 if (e->rxhash == rxhash)
230 return e;
231 }
232 return NULL;
233 }
234
235 static struct tun_flow_entry *tun_flow_create(struct tun_struct *tun,
236 struct hlist_head *head,
237 u32 rxhash, u16 queue_index)
238 {
239 struct tun_flow_entry *e = kmalloc(sizeof(*e), GFP_ATOMIC);
240
241 if (e) {
242 tun_debug(KERN_INFO, tun, "create flow: hash %u index %u\n",
243 rxhash, queue_index);
244 e->updated = jiffies;
245 e->rxhash = rxhash;
246 e->rps_rxhash = 0;
247 e->queue_index = queue_index;
248 e->tun = tun;
249 hlist_add_head_rcu(&e->hash_link, head);
250 ++tun->flow_count;
251 }
252 return e;
253 }
254
255 static void tun_flow_delete(struct tun_struct *tun, struct tun_flow_entry *e)
256 {
257 tun_debug(KERN_INFO, tun, "delete flow: hash %u index %u\n",
258 e->rxhash, e->queue_index);
259 hlist_del_rcu(&e->hash_link);
260 kfree_rcu(e, rcu);
261 --tun->flow_count;
262 }
263
264 static void tun_flow_flush(struct tun_struct *tun)
265 {
266 int i;
267
268 spin_lock_bh(&tun->lock);
269 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
270 struct tun_flow_entry *e;
271 struct hlist_node *n;
272
273 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link)
274 tun_flow_delete(tun, e);
275 }
276 spin_unlock_bh(&tun->lock);
277 }
278
279 static void tun_flow_delete_by_queue(struct tun_struct *tun, u16 queue_index)
280 {
281 int i;
282
283 spin_lock_bh(&tun->lock);
284 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
285 struct tun_flow_entry *e;
286 struct hlist_node *n;
287
288 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
289 if (e->queue_index == queue_index)
290 tun_flow_delete(tun, e);
291 }
292 }
293 spin_unlock_bh(&tun->lock);
294 }
295
296 static void tun_flow_cleanup(unsigned long data)
297 {
298 struct tun_struct *tun = (struct tun_struct *)data;
299 unsigned long delay = tun->ageing_time;
300 unsigned long next_timer = jiffies + delay;
301 unsigned long count = 0;
302 int i;
303
304 tun_debug(KERN_INFO, tun, "tun_flow_cleanup\n");
305
306 spin_lock_bh(&tun->lock);
307 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
308 struct tun_flow_entry *e;
309 struct hlist_node *n;
310
311 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
312 unsigned long this_timer;
313 count++;
314 this_timer = e->updated + delay;
315 if (time_before_eq(this_timer, jiffies))
316 tun_flow_delete(tun, e);
317 else if (time_before(this_timer, next_timer))
318 next_timer = this_timer;
319 }
320 }
321
322 if (count)
323 mod_timer(&tun->flow_gc_timer, round_jiffies_up(next_timer));
324 spin_unlock_bh(&tun->lock);
325 }
326
327 static void tun_flow_update(struct tun_struct *tun, u32 rxhash,
328 struct tun_file *tfile)
329 {
330 struct hlist_head *head;
331 struct tun_flow_entry *e;
332 unsigned long delay = tun->ageing_time;
333 u16 queue_index = tfile->queue_index;
334
335 if (!rxhash)
336 return;
337 else
338 head = &tun->flows[tun_hashfn(rxhash)];
339
340 rcu_read_lock();
341
342 /* We may get a very small possibility of OOO during switching, not
343 * worth to optimize.*/
344 if (tun->numqueues == 1 || tfile->detached)
345 goto unlock;
346
347 e = tun_flow_find(head, rxhash);
348 if (likely(e)) {
349 /* TODO: keep queueing to old queue until it's empty? */
350 e->queue_index = queue_index;
351 e->updated = jiffies;
352 sock_rps_record_flow_hash(e->rps_rxhash);
353 } else {
354 spin_lock_bh(&tun->lock);
355 if (!tun_flow_find(head, rxhash) &&
356 tun->flow_count < MAX_TAP_FLOWS)
357 tun_flow_create(tun, head, rxhash, queue_index);
358
359 if (!timer_pending(&tun->flow_gc_timer))
360 mod_timer(&tun->flow_gc_timer,
361 round_jiffies_up(jiffies + delay));
362 spin_unlock_bh(&tun->lock);
363 }
364
365 unlock:
366 rcu_read_unlock();
367 }
368
369 /**
370 * Save the hash received in the stack receive path and update the
371 * flow_hash table accordingly.
372 */
373 static inline void tun_flow_save_rps_rxhash(struct tun_flow_entry *e, u32 hash)
374 {
375 if (unlikely(e->rps_rxhash != hash))
376 e->rps_rxhash = hash;
377 }
378
379 /* We try to identify a flow through its rxhash first. The reason that
380 * we do not check rxq no. is because some cards(e.g 82599), chooses
381 * the rxq based on the txq where the last packet of the flow comes. As
382 * the userspace application move between processors, we may get a
383 * different rxq no. here. If we could not get rxhash, then we would
384 * hope the rxq no. may help here.
385 */
386 static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb,
387 void *accel_priv, select_queue_fallback_t fallback)
388 {
389 struct tun_struct *tun = netdev_priv(dev);
390 struct tun_flow_entry *e;
391 u32 txq = 0;
392 u32 numqueues = 0;
393
394 rcu_read_lock();
395 numqueues = ACCESS_ONCE(tun->numqueues);
396
397 txq = skb_get_hash(skb);
398 if (txq) {
399 e = tun_flow_find(&tun->flows[tun_hashfn(txq)], txq);
400 if (e) {
401 tun_flow_save_rps_rxhash(e, txq);
402 txq = e->queue_index;
403 } else
404 /* use multiply and shift instead of expensive divide */
405 txq = ((u64)txq * numqueues) >> 32;
406 } else if (likely(skb_rx_queue_recorded(skb))) {
407 txq = skb_get_rx_queue(skb);
408 while (unlikely(txq >= numqueues))
409 txq -= numqueues;
410 }
411
412 rcu_read_unlock();
413 return txq;
414 }
415
416 static inline bool tun_not_capable(struct tun_struct *tun)
417 {
418 const struct cred *cred = current_cred();
419 struct net *net = dev_net(tun->dev);
420
421 return ((uid_valid(tun->owner) && !uid_eq(cred->euid, tun->owner)) ||
422 (gid_valid(tun->group) && !in_egroup_p(tun->group))) &&
423 !ns_capable(net->user_ns, CAP_NET_ADMIN);
424 }
425
426 static void tun_set_real_num_queues(struct tun_struct *tun)
427 {
428 netif_set_real_num_tx_queues(tun->dev, tun->numqueues);
429 netif_set_real_num_rx_queues(tun->dev, tun->numqueues);
430 }
431
432 static void tun_disable_queue(struct tun_struct *tun, struct tun_file *tfile)
433 {
434 tfile->detached = tun;
435 list_add_tail(&tfile->next, &tun->disabled);
436 ++tun->numdisabled;
437 }
438
439 static struct tun_struct *tun_enable_queue(struct tun_file *tfile)
440 {
441 struct tun_struct *tun = tfile->detached;
442
443 tfile->detached = NULL;
444 list_del_init(&tfile->next);
445 --tun->numdisabled;
446 return tun;
447 }
448
449 static void tun_queue_purge(struct tun_file *tfile)
450 {
451 skb_queue_purge(&tfile->sk.sk_receive_queue);
452 skb_queue_purge(&tfile->sk.sk_error_queue);
453 }
454
455 static void __tun_detach(struct tun_file *tfile, bool clean)
456 {
457 struct tun_file *ntfile;
458 struct tun_struct *tun;
459
460 tun = rtnl_dereference(tfile->tun);
461
462 if (tun && !tfile->detached) {
463 u16 index = tfile->queue_index;
464 BUG_ON(index >= tun->numqueues);
465
466 rcu_assign_pointer(tun->tfiles[index],
467 tun->tfiles[tun->numqueues - 1]);
468 ntfile = rtnl_dereference(tun->tfiles[index]);
469 ntfile->queue_index = index;
470
471 --tun->numqueues;
472 if (clean) {
473 RCU_INIT_POINTER(tfile->tun, NULL);
474 sock_put(&tfile->sk);
475 } else
476 tun_disable_queue(tun, tfile);
477
478 synchronize_net();
479 tun_flow_delete_by_queue(tun, tun->numqueues + 1);
480 /* Drop read queue */
481 tun_queue_purge(tfile);
482 tun_set_real_num_queues(tun);
483 } else if (tfile->detached && clean) {
484 tun = tun_enable_queue(tfile);
485 sock_put(&tfile->sk);
486 }
487
488 if (clean) {
489 if (tun && tun->numqueues == 0 && tun->numdisabled == 0) {
490 netif_carrier_off(tun->dev);
491
492 if (!(tun->flags & IFF_PERSIST) &&
493 tun->dev->reg_state == NETREG_REGISTERED)
494 unregister_netdevice(tun->dev);
495 }
496
497 BUG_ON(!test_bit(SOCK_EXTERNALLY_ALLOCATED,
498 &tfile->socket.flags));
499 sk_release_kernel(&tfile->sk);
500 }
501 }
502
503 static void tun_detach(struct tun_file *tfile, bool clean)
504 {
505 rtnl_lock();
506 __tun_detach(tfile, clean);
507 rtnl_unlock();
508 }
509
510 static void tun_detach_all(struct net_device *dev)
511 {
512 struct tun_struct *tun = netdev_priv(dev);
513 struct tun_file *tfile, *tmp;
514 int i, n = tun->numqueues;
515
516 for (i = 0; i < n; i++) {
517 tfile = rtnl_dereference(tun->tfiles[i]);
518 BUG_ON(!tfile);
519 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
520 RCU_INIT_POINTER(tfile->tun, NULL);
521 --tun->numqueues;
522 }
523 list_for_each_entry(tfile, &tun->disabled, next) {
524 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
525 RCU_INIT_POINTER(tfile->tun, NULL);
526 }
527 BUG_ON(tun->numqueues != 0);
528
529 synchronize_net();
530 for (i = 0; i < n; i++) {
531 tfile = rtnl_dereference(tun->tfiles[i]);
532 /* Drop read queue */
533 tun_queue_purge(tfile);
534 sock_put(&tfile->sk);
535 }
536 list_for_each_entry_safe(tfile, tmp, &tun->disabled, next) {
537 tun_enable_queue(tfile);
538 tun_queue_purge(tfile);
539 sock_put(&tfile->sk);
540 }
541 BUG_ON(tun->numdisabled != 0);
542
543 if (tun->flags & IFF_PERSIST)
544 module_put(THIS_MODULE);
545 }
546
547 static int tun_attach(struct tun_struct *tun, struct file *file, bool skip_filter)
548 {
549 struct tun_file *tfile = file->private_data;
550 int err;
551
552 err = security_tun_dev_attach(tfile->socket.sk, tun->security);
553 if (err < 0)
554 goto out;
555
556 err = -EINVAL;
557 if (rtnl_dereference(tfile->tun) && !tfile->detached)
558 goto out;
559
560 err = -EBUSY;
561 if (!(tun->flags & IFF_MULTI_QUEUE) && tun->numqueues == 1)
562 goto out;
563
564 err = -E2BIG;
565 if (!tfile->detached &&
566 tun->numqueues + tun->numdisabled == MAX_TAP_QUEUES)
567 goto out;
568
569 err = 0;
570
571 /* Re-attach the filter to persist device */
572 if (!skip_filter && (tun->filter_attached == true)) {
573 err = sk_attach_filter(&tun->fprog, tfile->socket.sk);
574 if (!err)
575 goto out;
576 }
577 tfile->queue_index = tun->numqueues;
578 rcu_assign_pointer(tfile->tun, tun);
579 rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile);
580 tun->numqueues++;
581
582 if (tfile->detached)
583 tun_enable_queue(tfile);
584 else
585 sock_hold(&tfile->sk);
586
587 tun_set_real_num_queues(tun);
588
589 /* device is allowed to go away first, so no need to hold extra
590 * refcnt.
591 */
592
593 out:
594 return err;
595 }
596
597 static struct tun_struct *__tun_get(struct tun_file *tfile)
598 {
599 struct tun_struct *tun;
600
601 rcu_read_lock();
602 tun = rcu_dereference(tfile->tun);
603 if (tun)
604 dev_hold(tun->dev);
605 rcu_read_unlock();
606
607 return tun;
608 }
609
610 static struct tun_struct *tun_get(struct file *file)
611 {
612 return __tun_get(file->private_data);
613 }
614
615 static void tun_put(struct tun_struct *tun)
616 {
617 dev_put(tun->dev);
618 }
619
620 /* TAP filtering */
621 static void addr_hash_set(u32 *mask, const u8 *addr)
622 {
623 int n = ether_crc(ETH_ALEN, addr) >> 26;
624 mask[n >> 5] |= (1 << (n & 31));
625 }
626
627 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
628 {
629 int n = ether_crc(ETH_ALEN, addr) >> 26;
630 return mask[n >> 5] & (1 << (n & 31));
631 }
632
633 static int update_filter(struct tap_filter *filter, void __user *arg)
634 {
635 struct { u8 u[ETH_ALEN]; } *addr;
636 struct tun_filter uf;
637 int err, alen, n, nexact;
638
639 if (copy_from_user(&uf, arg, sizeof(uf)))
640 return -EFAULT;
641
642 if (!uf.count) {
643 /* Disabled */
644 filter->count = 0;
645 return 0;
646 }
647
648 alen = ETH_ALEN * uf.count;
649 addr = kmalloc(alen, GFP_KERNEL);
650 if (!addr)
651 return -ENOMEM;
652
653 if (copy_from_user(addr, arg + sizeof(uf), alen)) {
654 err = -EFAULT;
655 goto done;
656 }
657
658 /* The filter is updated without holding any locks. Which is
659 * perfectly safe. We disable it first and in the worst
660 * case we'll accept a few undesired packets. */
661 filter->count = 0;
662 wmb();
663
664 /* Use first set of addresses as an exact filter */
665 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
666 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
667
668 nexact = n;
669
670 /* Remaining multicast addresses are hashed,
671 * unicast will leave the filter disabled. */
672 memset(filter->mask, 0, sizeof(filter->mask));
673 for (; n < uf.count; n++) {
674 if (!is_multicast_ether_addr(addr[n].u)) {
675 err = 0; /* no filter */
676 goto done;
677 }
678 addr_hash_set(filter->mask, addr[n].u);
679 }
680
681 /* For ALLMULTI just set the mask to all ones.
682 * This overrides the mask populated above. */
683 if ((uf.flags & TUN_FLT_ALLMULTI))
684 memset(filter->mask, ~0, sizeof(filter->mask));
685
686 /* Now enable the filter */
687 wmb();
688 filter->count = nexact;
689
690 /* Return the number of exact filters */
691 err = nexact;
692
693 done:
694 kfree(addr);
695 return err;
696 }
697
698 /* Returns: 0 - drop, !=0 - accept */
699 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
700 {
701 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
702 * at this point. */
703 struct ethhdr *eh = (struct ethhdr *) skb->data;
704 int i;
705
706 /* Exact match */
707 for (i = 0; i < filter->count; i++)
708 if (ether_addr_equal(eh->h_dest, filter->addr[i]))
709 return 1;
710
711 /* Inexact match (multicast only) */
712 if (is_multicast_ether_addr(eh->h_dest))
713 return addr_hash_test(filter->mask, eh->h_dest);
714
715 return 0;
716 }
717
718 /*
719 * Checks whether the packet is accepted or not.
720 * Returns: 0 - drop, !=0 - accept
721 */
722 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
723 {
724 if (!filter->count)
725 return 1;
726
727 return run_filter(filter, skb);
728 }
729
730 /* Network device part of the driver */
731
732 static const struct ethtool_ops tun_ethtool_ops;
733
734 /* Net device detach from fd. */
735 static void tun_net_uninit(struct net_device *dev)
736 {
737 tun_detach_all(dev);
738 }
739
740 /* Net device open. */
741 static int tun_net_open(struct net_device *dev)
742 {
743 netif_tx_start_all_queues(dev);
744 return 0;
745 }
746
747 /* Net device close. */
748 static int tun_net_close(struct net_device *dev)
749 {
750 netif_tx_stop_all_queues(dev);
751 return 0;
752 }
753
754 /* Net device start xmit */
755 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
756 {
757 struct tun_struct *tun = netdev_priv(dev);
758 int txq = skb->queue_mapping;
759 struct tun_file *tfile;
760 u32 numqueues = 0;
761
762 rcu_read_lock();
763 tfile = rcu_dereference(tun->tfiles[txq]);
764 numqueues = ACCESS_ONCE(tun->numqueues);
765
766 /* Drop packet if interface is not attached */
767 if (txq >= numqueues)
768 goto drop;
769
770 if (numqueues == 1) {
771 /* Select queue was not called for the skbuff, so we extract the
772 * RPS hash and save it into the flow_table here.
773 */
774 __u32 rxhash;
775
776 rxhash = skb_get_hash(skb);
777 if (rxhash) {
778 struct tun_flow_entry *e;
779 e = tun_flow_find(&tun->flows[tun_hashfn(rxhash)],
780 rxhash);
781 if (e)
782 tun_flow_save_rps_rxhash(e, rxhash);
783 }
784 }
785
786 tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len);
787
788 BUG_ON(!tfile);
789
790 /* Drop if the filter does not like it.
791 * This is a noop if the filter is disabled.
792 * Filter can be enabled only for the TAP devices. */
793 if (!check_filter(&tun->txflt, skb))
794 goto drop;
795
796 if (tfile->socket.sk->sk_filter &&
797 sk_filter(tfile->socket.sk, skb))
798 goto drop;
799
800 /* Limit the number of packets queued by dividing txq length with the
801 * number of queues.
802 */
803 if (skb_queue_len(&tfile->socket.sk->sk_receive_queue) * numqueues
804 >= dev->tx_queue_len)
805 goto drop;
806
807 if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
808 goto drop;
809
810 if (skb->sk) {
811 sock_tx_timestamp(skb->sk, &skb_shinfo(skb)->tx_flags);
812 sw_tx_timestamp(skb);
813 }
814
815 /* Orphan the skb - required as we might hang on to it
816 * for indefinite time.
817 */
818 skb_orphan(skb);
819
820 nf_reset(skb);
821
822 /* Enqueue packet */
823 skb_queue_tail(&tfile->socket.sk->sk_receive_queue, skb);
824
825 /* Notify and wake up reader process */
826 if (tfile->flags & TUN_FASYNC)
827 kill_fasync(&tfile->fasync, SIGIO, POLL_IN);
828 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
829
830 rcu_read_unlock();
831 return NETDEV_TX_OK;
832
833 drop:
834 dev->stats.tx_dropped++;
835 skb_tx_error(skb);
836 kfree_skb(skb);
837 rcu_read_unlock();
838 return NET_XMIT_DROP;
839 }
840
841 static void tun_net_mclist(struct net_device *dev)
842 {
843 /*
844 * This callback is supposed to deal with mc filter in
845 * _rx_ path and has nothing to do with the _tx_ path.
846 * In rx path we always accept everything userspace gives us.
847 */
848 }
849
850 #define MIN_MTU 68
851 #define MAX_MTU 65535
852
853 static int
854 tun_net_change_mtu(struct net_device *dev, int new_mtu)
855 {
856 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
857 return -EINVAL;
858 dev->mtu = new_mtu;
859 return 0;
860 }
861
862 static netdev_features_t tun_net_fix_features(struct net_device *dev,
863 netdev_features_t features)
864 {
865 struct tun_struct *tun = netdev_priv(dev);
866
867 return (features & tun->set_features) | (features & ~TUN_USER_FEATURES);
868 }
869 #ifdef CONFIG_NET_POLL_CONTROLLER
870 static void tun_poll_controller(struct net_device *dev)
871 {
872 /*
873 * Tun only receives frames when:
874 * 1) the char device endpoint gets data from user space
875 * 2) the tun socket gets a sendmsg call from user space
876 * Since both of those are synchronous operations, we are guaranteed
877 * never to have pending data when we poll for it
878 * so there is nothing to do here but return.
879 * We need this though so netpoll recognizes us as an interface that
880 * supports polling, which enables bridge devices in virt setups to
881 * still use netconsole
882 */
883 return;
884 }
885 #endif
886 static const struct net_device_ops tun_netdev_ops = {
887 .ndo_uninit = tun_net_uninit,
888 .ndo_open = tun_net_open,
889 .ndo_stop = tun_net_close,
890 .ndo_start_xmit = tun_net_xmit,
891 .ndo_change_mtu = tun_net_change_mtu,
892 .ndo_fix_features = tun_net_fix_features,
893 .ndo_select_queue = tun_select_queue,
894 #ifdef CONFIG_NET_POLL_CONTROLLER
895 .ndo_poll_controller = tun_poll_controller,
896 #endif
897 };
898
899 static const struct net_device_ops tap_netdev_ops = {
900 .ndo_uninit = tun_net_uninit,
901 .ndo_open = tun_net_open,
902 .ndo_stop = tun_net_close,
903 .ndo_start_xmit = tun_net_xmit,
904 .ndo_change_mtu = tun_net_change_mtu,
905 .ndo_fix_features = tun_net_fix_features,
906 .ndo_set_rx_mode = tun_net_mclist,
907 .ndo_set_mac_address = eth_mac_addr,
908 .ndo_validate_addr = eth_validate_addr,
909 .ndo_select_queue = tun_select_queue,
910 #ifdef CONFIG_NET_POLL_CONTROLLER
911 .ndo_poll_controller = tun_poll_controller,
912 #endif
913 };
914
915 static void tun_flow_init(struct tun_struct *tun)
916 {
917 int i;
918
919 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++)
920 INIT_HLIST_HEAD(&tun->flows[i]);
921
922 tun->ageing_time = TUN_FLOW_EXPIRE;
923 setup_timer(&tun->flow_gc_timer, tun_flow_cleanup, (unsigned long)tun);
924 mod_timer(&tun->flow_gc_timer,
925 round_jiffies_up(jiffies + tun->ageing_time));
926 }
927
928 static void tun_flow_uninit(struct tun_struct *tun)
929 {
930 del_timer_sync(&tun->flow_gc_timer);
931 tun_flow_flush(tun);
932 }
933
934 /* Initialize net device. */
935 static void tun_net_init(struct net_device *dev)
936 {
937 struct tun_struct *tun = netdev_priv(dev);
938
939 switch (tun->flags & TUN_TYPE_MASK) {
940 case IFF_TUN:
941 dev->netdev_ops = &tun_netdev_ops;
942
943 /* Point-to-Point TUN Device */
944 dev->hard_header_len = 0;
945 dev->addr_len = 0;
946 dev->mtu = 1500;
947
948 /* Zero header length */
949 dev->type = ARPHRD_NONE;
950 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
951 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
952 break;
953
954 case IFF_TAP:
955 dev->netdev_ops = &tap_netdev_ops;
956 /* Ethernet TAP Device */
957 ether_setup(dev);
958 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
959 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
960
961 eth_hw_addr_random(dev);
962
963 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
964 break;
965 }
966 }
967
968 /* Character device part */
969
970 /* Poll */
971 static unsigned int tun_chr_poll(struct file *file, poll_table *wait)
972 {
973 struct tun_file *tfile = file->private_data;
974 struct tun_struct *tun = __tun_get(tfile);
975 struct sock *sk;
976 unsigned int mask = 0;
977
978 if (!tun)
979 return POLLERR;
980
981 sk = tfile->socket.sk;
982
983 tun_debug(KERN_INFO, tun, "tun_chr_poll\n");
984
985 poll_wait(file, sk_sleep(sk), wait);
986
987 if (!skb_queue_empty(&sk->sk_receive_queue))
988 mask |= POLLIN | POLLRDNORM;
989
990 if (sock_writeable(sk) ||
991 (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
992 sock_writeable(sk)))
993 mask |= POLLOUT | POLLWRNORM;
994
995 if (tun->dev->reg_state != NETREG_REGISTERED)
996 mask = POLLERR;
997
998 tun_put(tun);
999 return mask;
1000 }
1001
1002 /* prepad is the amount to reserve at front. len is length after that.
1003 * linear is a hint as to how much to copy (usually headers). */
1004 static struct sk_buff *tun_alloc_skb(struct tun_file *tfile,
1005 size_t prepad, size_t len,
1006 size_t linear, int noblock)
1007 {
1008 struct sock *sk = tfile->socket.sk;
1009 struct sk_buff *skb;
1010 int err;
1011
1012 /* Under a page? Don't bother with paged skb. */
1013 if (prepad + len < PAGE_SIZE || !linear)
1014 linear = len;
1015
1016 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
1017 &err, 0);
1018 if (!skb)
1019 return ERR_PTR(err);
1020
1021 skb_reserve(skb, prepad);
1022 skb_put(skb, linear);
1023 skb->data_len = len - linear;
1024 skb->len += len - linear;
1025
1026 return skb;
1027 }
1028
1029 /* Get packet from user space buffer */
1030 static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
1031 void *msg_control, struct iov_iter *from,
1032 int noblock)
1033 {
1034 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
1035 struct sk_buff *skb;
1036 size_t total_len = iov_iter_count(from);
1037 size_t len = total_len, align = NET_SKB_PAD, linear;
1038 struct virtio_net_hdr gso = { 0 };
1039 int good_linear;
1040 int copylen;
1041 bool zerocopy = false;
1042 int err;
1043 u32 rxhash;
1044 ssize_t n;
1045
1046 if (!(tun->flags & IFF_NO_PI)) {
1047 if (len < sizeof(pi))
1048 return -EINVAL;
1049 len -= sizeof(pi);
1050
1051 n = copy_from_iter(&pi, sizeof(pi), from);
1052 if (n != sizeof(pi))
1053 return -EFAULT;
1054 }
1055
1056 if (tun->flags & IFF_VNET_HDR) {
1057 if (len < tun->vnet_hdr_sz)
1058 return -EINVAL;
1059 len -= tun->vnet_hdr_sz;
1060
1061 n = copy_from_iter(&gso, sizeof(gso), from);
1062 if (n != sizeof(gso))
1063 return -EFAULT;
1064
1065 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
1066 tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2 > tun16_to_cpu(tun, gso.hdr_len))
1067 gso.hdr_len = cpu_to_tun16(tun, tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2);
1068
1069 if (tun16_to_cpu(tun, gso.hdr_len) > len)
1070 return -EINVAL;
1071 iov_iter_advance(from, tun->vnet_hdr_sz - sizeof(gso));
1072 }
1073
1074 if ((tun->flags & TUN_TYPE_MASK) == IFF_TAP) {
1075 align += NET_IP_ALIGN;
1076 if (unlikely(len < ETH_HLEN ||
1077 (gso.hdr_len && tun16_to_cpu(tun, gso.hdr_len) < ETH_HLEN)))
1078 return -EINVAL;
1079 }
1080
1081 good_linear = SKB_MAX_HEAD(align);
1082
1083 if (msg_control) {
1084 struct iov_iter i = *from;
1085
1086 /* There are 256 bytes to be copied in skb, so there is
1087 * enough room for skb expand head in case it is used.
1088 * The rest of the buffer is mapped from userspace.
1089 */
1090 copylen = gso.hdr_len ? tun16_to_cpu(tun, gso.hdr_len) : GOODCOPY_LEN;
1091 if (copylen > good_linear)
1092 copylen = good_linear;
1093 linear = copylen;
1094 iov_iter_advance(&i, copylen);
1095 if (iov_iter_npages(&i, INT_MAX) <= MAX_SKB_FRAGS)
1096 zerocopy = true;
1097 }
1098
1099 if (!zerocopy) {
1100 copylen = len;
1101 if (tun16_to_cpu(tun, gso.hdr_len) > good_linear)
1102 linear = good_linear;
1103 else
1104 linear = tun16_to_cpu(tun, gso.hdr_len);
1105 }
1106
1107 skb = tun_alloc_skb(tfile, align, copylen, linear, noblock);
1108 if (IS_ERR(skb)) {
1109 if (PTR_ERR(skb) != -EAGAIN)
1110 tun->dev->stats.rx_dropped++;
1111 return PTR_ERR(skb);
1112 }
1113
1114 if (zerocopy)
1115 err = zerocopy_sg_from_iter(skb, from);
1116 else {
1117 err = skb_copy_datagram_from_iter(skb, 0, from, len);
1118 if (!err && msg_control) {
1119 struct ubuf_info *uarg = msg_control;
1120 uarg->callback(uarg, false);
1121 }
1122 }
1123
1124 if (err) {
1125 tun->dev->stats.rx_dropped++;
1126 kfree_skb(skb);
1127 return -EFAULT;
1128 }
1129
1130 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
1131 if (!skb_partial_csum_set(skb, tun16_to_cpu(tun, gso.csum_start),
1132 tun16_to_cpu(tun, gso.csum_offset))) {
1133 tun->dev->stats.rx_frame_errors++;
1134 kfree_skb(skb);
1135 return -EINVAL;
1136 }
1137 }
1138
1139 switch (tun->flags & TUN_TYPE_MASK) {
1140 case IFF_TUN:
1141 if (tun->flags & IFF_NO_PI) {
1142 switch (skb->data[0] & 0xf0) {
1143 case 0x40:
1144 pi.proto = htons(ETH_P_IP);
1145 break;
1146 case 0x60:
1147 pi.proto = htons(ETH_P_IPV6);
1148 break;
1149 default:
1150 tun->dev->stats.rx_dropped++;
1151 kfree_skb(skb);
1152 return -EINVAL;
1153 }
1154 }
1155
1156 skb_reset_mac_header(skb);
1157 skb->protocol = pi.proto;
1158 skb->dev = tun->dev;
1159 break;
1160 case IFF_TAP:
1161 skb->protocol = eth_type_trans(skb, tun->dev);
1162 break;
1163 }
1164
1165 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
1166 pr_debug("GSO!\n");
1167 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
1168 case VIRTIO_NET_HDR_GSO_TCPV4:
1169 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
1170 break;
1171 case VIRTIO_NET_HDR_GSO_TCPV6:
1172 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
1173 break;
1174 case VIRTIO_NET_HDR_GSO_UDP:
1175 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
1176 break;
1177 default:
1178 tun->dev->stats.rx_frame_errors++;
1179 kfree_skb(skb);
1180 return -EINVAL;
1181 }
1182
1183 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
1184 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
1185
1186 skb_shinfo(skb)->gso_size = tun16_to_cpu(tun, gso.gso_size);
1187 if (skb_shinfo(skb)->gso_size == 0) {
1188 tun->dev->stats.rx_frame_errors++;
1189 kfree_skb(skb);
1190 return -EINVAL;
1191 }
1192
1193 /* Header must be checked, and gso_segs computed. */
1194 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
1195 skb_shinfo(skb)->gso_segs = 0;
1196 }
1197
1198 /* copy skb_ubuf_info for callback when skb has no error */
1199 if (zerocopy) {
1200 skb_shinfo(skb)->destructor_arg = msg_control;
1201 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1202 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
1203 }
1204
1205 skb_reset_network_header(skb);
1206 skb_probe_transport_header(skb, 0);
1207
1208 rxhash = skb_get_hash(skb);
1209 netif_rx_ni(skb);
1210
1211 tun->dev->stats.rx_packets++;
1212 tun->dev->stats.rx_bytes += len;
1213
1214 tun_flow_update(tun, rxhash, tfile);
1215 return total_len;
1216 }
1217
1218 static ssize_t tun_chr_write_iter(struct kiocb *iocb, struct iov_iter *from)
1219 {
1220 struct file *file = iocb->ki_filp;
1221 struct tun_struct *tun = tun_get(file);
1222 struct tun_file *tfile = file->private_data;
1223 ssize_t result;
1224
1225 if (!tun)
1226 return -EBADFD;
1227
1228 result = tun_get_user(tun, tfile, NULL, from, file->f_flags & O_NONBLOCK);
1229
1230 tun_put(tun);
1231 return result;
1232 }
1233
1234 /* Put packet to the user space buffer */
1235 static ssize_t tun_put_user(struct tun_struct *tun,
1236 struct tun_file *tfile,
1237 struct sk_buff *skb,
1238 struct iov_iter *iter)
1239 {
1240 struct tun_pi pi = { 0, skb->protocol };
1241 ssize_t total;
1242 int vlan_offset = 0;
1243 int vlan_hlen = 0;
1244 int vnet_hdr_sz = 0;
1245
1246 if (skb_vlan_tag_present(skb))
1247 vlan_hlen = VLAN_HLEN;
1248
1249 if (tun->flags & IFF_VNET_HDR)
1250 vnet_hdr_sz = tun->vnet_hdr_sz;
1251
1252 total = skb->len + vlan_hlen + vnet_hdr_sz;
1253
1254 if (!(tun->flags & IFF_NO_PI)) {
1255 if (iov_iter_count(iter) < sizeof(pi))
1256 return -EINVAL;
1257
1258 total += sizeof(pi);
1259 if (iov_iter_count(iter) < total) {
1260 /* Packet will be striped */
1261 pi.flags |= TUN_PKT_STRIP;
1262 }
1263
1264 if (copy_to_iter(&pi, sizeof(pi), iter) != sizeof(pi))
1265 return -EFAULT;
1266 }
1267
1268 if (vnet_hdr_sz) {
1269 struct virtio_net_hdr gso = { 0 }; /* no info leak */
1270 if (iov_iter_count(iter) < vnet_hdr_sz)
1271 return -EINVAL;
1272
1273 if (skb_is_gso(skb)) {
1274 struct skb_shared_info *sinfo = skb_shinfo(skb);
1275
1276 /* This is a hint as to how much should be linear. */
1277 gso.hdr_len = cpu_to_tun16(tun, skb_headlen(skb));
1278 gso.gso_size = cpu_to_tun16(tun, sinfo->gso_size);
1279 if (sinfo->gso_type & SKB_GSO_TCPV4)
1280 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
1281 else if (sinfo->gso_type & SKB_GSO_TCPV6)
1282 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
1283 else if (sinfo->gso_type & SKB_GSO_UDP)
1284 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
1285 else {
1286 pr_err("unexpected GSO type: "
1287 "0x%x, gso_size %d, hdr_len %d\n",
1288 sinfo->gso_type, tun16_to_cpu(tun, gso.gso_size),
1289 tun16_to_cpu(tun, gso.hdr_len));
1290 print_hex_dump(KERN_ERR, "tun: ",
1291 DUMP_PREFIX_NONE,
1292 16, 1, skb->head,
1293 min((int)tun16_to_cpu(tun, gso.hdr_len), 64), true);
1294 WARN_ON_ONCE(1);
1295 return -EINVAL;
1296 }
1297 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
1298 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
1299 } else
1300 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
1301
1302 if (skb->ip_summed == CHECKSUM_PARTIAL) {
1303 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
1304 gso.csum_start = cpu_to_tun16(tun, skb_checksum_start_offset(skb) +
1305 vlan_hlen);
1306 gso.csum_offset = cpu_to_tun16(tun, skb->csum_offset);
1307 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
1308 gso.flags = VIRTIO_NET_HDR_F_DATA_VALID;
1309 } /* else everything is zero */
1310
1311 if (copy_to_iter(&gso, sizeof(gso), iter) != sizeof(gso))
1312 return -EFAULT;
1313
1314 iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso));
1315 }
1316
1317 if (vlan_hlen) {
1318 int ret;
1319 struct {
1320 __be16 h_vlan_proto;
1321 __be16 h_vlan_TCI;
1322 } veth;
1323
1324 veth.h_vlan_proto = skb->vlan_proto;
1325 veth.h_vlan_TCI = htons(skb_vlan_tag_get(skb));
1326
1327 vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);
1328
1329 ret = skb_copy_datagram_iter(skb, 0, iter, vlan_offset);
1330 if (ret || !iov_iter_count(iter))
1331 goto done;
1332
1333 ret = copy_to_iter(&veth, sizeof(veth), iter);
1334 if (ret != sizeof(veth) || !iov_iter_count(iter))
1335 goto done;
1336 }
1337
1338 skb_copy_datagram_iter(skb, vlan_offset, iter, skb->len - vlan_offset);
1339
1340 done:
1341 tun->dev->stats.tx_packets++;
1342 tun->dev->stats.tx_bytes += skb->len + vlan_hlen;
1343
1344 return total;
1345 }
1346
1347 static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
1348 struct iov_iter *to,
1349 int noblock)
1350 {
1351 struct sk_buff *skb;
1352 ssize_t ret;
1353 int peeked, err, off = 0;
1354
1355 tun_debug(KERN_INFO, tun, "tun_do_read\n");
1356
1357 if (!iov_iter_count(to))
1358 return 0;
1359
1360 if (tun->dev->reg_state != NETREG_REGISTERED)
1361 return -EIO;
1362
1363 /* Read frames from queue */
1364 skb = __skb_recv_datagram(tfile->socket.sk, noblock ? MSG_DONTWAIT : 0,
1365 &peeked, &off, &err);
1366 if (!skb)
1367 return err;
1368
1369 ret = tun_put_user(tun, tfile, skb, to);
1370 if (unlikely(ret < 0))
1371 kfree_skb(skb);
1372 else
1373 consume_skb(skb);
1374
1375 return ret;
1376 }
1377
1378 static ssize_t tun_chr_read_iter(struct kiocb *iocb, struct iov_iter *to)
1379 {
1380 struct file *file = iocb->ki_filp;
1381 struct tun_file *tfile = file->private_data;
1382 struct tun_struct *tun = __tun_get(tfile);
1383 ssize_t len = iov_iter_count(to), ret;
1384
1385 if (!tun)
1386 return -EBADFD;
1387 ret = tun_do_read(tun, tfile, to, file->f_flags & O_NONBLOCK);
1388 ret = min_t(ssize_t, ret, len);
1389 if (ret > 0)
1390 iocb->ki_pos = ret;
1391 tun_put(tun);
1392 return ret;
1393 }
1394
1395 static void tun_free_netdev(struct net_device *dev)
1396 {
1397 struct tun_struct *tun = netdev_priv(dev);
1398
1399 BUG_ON(!(list_empty(&tun->disabled)));
1400 tun_flow_uninit(tun);
1401 security_tun_dev_free_security(tun->security);
1402 free_netdev(dev);
1403 }
1404
1405 static void tun_setup(struct net_device *dev)
1406 {
1407 struct tun_struct *tun = netdev_priv(dev);
1408
1409 tun->owner = INVALID_UID;
1410 tun->group = INVALID_GID;
1411
1412 dev->ethtool_ops = &tun_ethtool_ops;
1413 dev->destructor = tun_free_netdev;
1414 }
1415
1416 /* Trivial set of netlink ops to allow deleting tun or tap
1417 * device with netlink.
1418 */
1419 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
1420 {
1421 return -EINVAL;
1422 }
1423
1424 static struct rtnl_link_ops tun_link_ops __read_mostly = {
1425 .kind = DRV_NAME,
1426 .priv_size = sizeof(struct tun_struct),
1427 .setup = tun_setup,
1428 .validate = tun_validate,
1429 };
1430
1431 static void tun_sock_write_space(struct sock *sk)
1432 {
1433 struct tun_file *tfile;
1434 wait_queue_head_t *wqueue;
1435
1436 if (!sock_writeable(sk))
1437 return;
1438
1439 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
1440 return;
1441
1442 wqueue = sk_sleep(sk);
1443 if (wqueue && waitqueue_active(wqueue))
1444 wake_up_interruptible_sync_poll(wqueue, POLLOUT |
1445 POLLWRNORM | POLLWRBAND);
1446
1447 tfile = container_of(sk, struct tun_file, sk);
1448 kill_fasync(&tfile->fasync, SIGIO, POLL_OUT);
1449 }
1450
1451 static int tun_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
1452 {
1453 int ret;
1454 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1455 struct tun_struct *tun = __tun_get(tfile);
1456
1457 if (!tun)
1458 return -EBADFD;
1459
1460 ret = tun_get_user(tun, tfile, m->msg_control, &m->msg_iter,
1461 m->msg_flags & MSG_DONTWAIT);
1462 tun_put(tun);
1463 return ret;
1464 }
1465
1466 static int tun_recvmsg(struct socket *sock, struct msghdr *m, size_t total_len,
1467 int flags)
1468 {
1469 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1470 struct tun_struct *tun = __tun_get(tfile);
1471 int ret;
1472
1473 if (!tun)
1474 return -EBADFD;
1475
1476 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC|MSG_ERRQUEUE)) {
1477 ret = -EINVAL;
1478 goto out;
1479 }
1480 if (flags & MSG_ERRQUEUE) {
1481 ret = sock_recv_errqueue(sock->sk, m, total_len,
1482 SOL_PACKET, TUN_TX_TIMESTAMP);
1483 goto out;
1484 }
1485 ret = tun_do_read(tun, tfile, &m->msg_iter, flags & MSG_DONTWAIT);
1486 if (ret > (ssize_t)total_len) {
1487 m->msg_flags |= MSG_TRUNC;
1488 ret = flags & MSG_TRUNC ? ret : total_len;
1489 }
1490 out:
1491 tun_put(tun);
1492 return ret;
1493 }
1494
1495 static int tun_release(struct socket *sock)
1496 {
1497 if (sock->sk)
1498 sock_put(sock->sk);
1499 return 0;
1500 }
1501
1502 /* Ops structure to mimic raw sockets with tun */
1503 static const struct proto_ops tun_socket_ops = {
1504 .sendmsg = tun_sendmsg,
1505 .recvmsg = tun_recvmsg,
1506 .release = tun_release,
1507 };
1508
1509 static struct proto tun_proto = {
1510 .name = "tun",
1511 .owner = THIS_MODULE,
1512 .obj_size = sizeof(struct tun_file),
1513 };
1514
1515 static int tun_flags(struct tun_struct *tun)
1516 {
1517 return tun->flags & (TUN_FEATURES | IFF_PERSIST | IFF_TUN | IFF_TAP);
1518 }
1519
1520 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
1521 char *buf)
1522 {
1523 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1524 return sprintf(buf, "0x%x\n", tun_flags(tun));
1525 }
1526
1527 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
1528 char *buf)
1529 {
1530 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1531 return uid_valid(tun->owner)?
1532 sprintf(buf, "%u\n",
1533 from_kuid_munged(current_user_ns(), tun->owner)):
1534 sprintf(buf, "-1\n");
1535 }
1536
1537 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
1538 char *buf)
1539 {
1540 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1541 return gid_valid(tun->group) ?
1542 sprintf(buf, "%u\n",
1543 from_kgid_munged(current_user_ns(), tun->group)):
1544 sprintf(buf, "-1\n");
1545 }
1546
1547 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
1548 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
1549 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
1550
1551 static struct attribute *tun_dev_attrs[] = {
1552 &dev_attr_tun_flags.attr,
1553 &dev_attr_owner.attr,
1554 &dev_attr_group.attr,
1555 NULL
1556 };
1557
1558 static const struct attribute_group tun_attr_group = {
1559 .attrs = tun_dev_attrs
1560 };
1561
1562 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
1563 {
1564 struct tun_struct *tun;
1565 struct tun_file *tfile = file->private_data;
1566 struct net_device *dev;
1567 int err;
1568
1569 if (tfile->detached)
1570 return -EINVAL;
1571
1572 dev = __dev_get_by_name(net, ifr->ifr_name);
1573 if (dev) {
1574 if (ifr->ifr_flags & IFF_TUN_EXCL)
1575 return -EBUSY;
1576 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
1577 tun = netdev_priv(dev);
1578 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
1579 tun = netdev_priv(dev);
1580 else
1581 return -EINVAL;
1582
1583 if (!!(ifr->ifr_flags & IFF_MULTI_QUEUE) !=
1584 !!(tun->flags & IFF_MULTI_QUEUE))
1585 return -EINVAL;
1586
1587 if (tun_not_capable(tun))
1588 return -EPERM;
1589 err = security_tun_dev_open(tun->security);
1590 if (err < 0)
1591 return err;
1592
1593 err = tun_attach(tun, file, ifr->ifr_flags & IFF_NOFILTER);
1594 if (err < 0)
1595 return err;
1596
1597 if (tun->flags & IFF_MULTI_QUEUE &&
1598 (tun->numqueues + tun->numdisabled > 1)) {
1599 /* One or more queue has already been attached, no need
1600 * to initialize the device again.
1601 */
1602 return 0;
1603 }
1604 }
1605 else {
1606 char *name;
1607 unsigned long flags = 0;
1608 int queues = ifr->ifr_flags & IFF_MULTI_QUEUE ?
1609 MAX_TAP_QUEUES : 1;
1610
1611 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1612 return -EPERM;
1613 err = security_tun_dev_create();
1614 if (err < 0)
1615 return err;
1616
1617 /* Set dev type */
1618 if (ifr->ifr_flags & IFF_TUN) {
1619 /* TUN device */
1620 flags |= IFF_TUN;
1621 name = "tun%d";
1622 } else if (ifr->ifr_flags & IFF_TAP) {
1623 /* TAP device */
1624 flags |= IFF_TAP;
1625 name = "tap%d";
1626 } else
1627 return -EINVAL;
1628
1629 if (*ifr->ifr_name)
1630 name = ifr->ifr_name;
1631
1632 dev = alloc_netdev_mqs(sizeof(struct tun_struct), name,
1633 NET_NAME_UNKNOWN, tun_setup, queues,
1634 queues);
1635
1636 if (!dev)
1637 return -ENOMEM;
1638
1639 dev_net_set(dev, net);
1640 dev->rtnl_link_ops = &tun_link_ops;
1641 dev->ifindex = tfile->ifindex;
1642 dev->sysfs_groups[0] = &tun_attr_group;
1643
1644 tun = netdev_priv(dev);
1645 tun->dev = dev;
1646 tun->flags = flags;
1647 tun->txflt.count = 0;
1648 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
1649
1650 tun->filter_attached = false;
1651 tun->sndbuf = tfile->socket.sk->sk_sndbuf;
1652
1653 spin_lock_init(&tun->lock);
1654
1655 err = security_tun_dev_alloc_security(&tun->security);
1656 if (err < 0)
1657 goto err_free_dev;
1658
1659 tun_net_init(dev);
1660 tun_flow_init(tun);
1661
1662 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
1663 TUN_USER_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
1664 NETIF_F_HW_VLAN_STAG_TX;
1665 dev->features = dev->hw_features;
1666 dev->vlan_features = dev->features &
1667 ~(NETIF_F_HW_VLAN_CTAG_TX |
1668 NETIF_F_HW_VLAN_STAG_TX);
1669
1670 INIT_LIST_HEAD(&tun->disabled);
1671 err = tun_attach(tun, file, false);
1672 if (err < 0)
1673 goto err_free_flow;
1674
1675 err = register_netdevice(tun->dev);
1676 if (err < 0)
1677 goto err_detach;
1678 }
1679
1680 netif_carrier_on(tun->dev);
1681
1682 tun_debug(KERN_INFO, tun, "tun_set_iff\n");
1683
1684 tun->flags = (tun->flags & ~TUN_FEATURES) |
1685 (ifr->ifr_flags & TUN_FEATURES);
1686
1687 /* Make sure persistent devices do not get stuck in
1688 * xoff state.
1689 */
1690 if (netif_running(tun->dev))
1691 netif_tx_wake_all_queues(tun->dev);
1692
1693 strcpy(ifr->ifr_name, tun->dev->name);
1694 return 0;
1695
1696 err_detach:
1697 tun_detach_all(dev);
1698 err_free_flow:
1699 tun_flow_uninit(tun);
1700 security_tun_dev_free_security(tun->security);
1701 err_free_dev:
1702 free_netdev(dev);
1703 return err;
1704 }
1705
1706 static void tun_get_iff(struct net *net, struct tun_struct *tun,
1707 struct ifreq *ifr)
1708 {
1709 tun_debug(KERN_INFO, tun, "tun_get_iff\n");
1710
1711 strcpy(ifr->ifr_name, tun->dev->name);
1712
1713 ifr->ifr_flags = tun_flags(tun);
1714
1715 }
1716
1717 /* This is like a cut-down ethtool ops, except done via tun fd so no
1718 * privs required. */
1719 static int set_offload(struct tun_struct *tun, unsigned long arg)
1720 {
1721 netdev_features_t features = 0;
1722
1723 if (arg & TUN_F_CSUM) {
1724 features |= NETIF_F_HW_CSUM;
1725 arg &= ~TUN_F_CSUM;
1726
1727 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1728 if (arg & TUN_F_TSO_ECN) {
1729 features |= NETIF_F_TSO_ECN;
1730 arg &= ~TUN_F_TSO_ECN;
1731 }
1732 if (arg & TUN_F_TSO4)
1733 features |= NETIF_F_TSO;
1734 if (arg & TUN_F_TSO6)
1735 features |= NETIF_F_TSO6;
1736 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1737 }
1738
1739 if (arg & TUN_F_UFO) {
1740 features |= NETIF_F_UFO;
1741 arg &= ~TUN_F_UFO;
1742 }
1743 }
1744
1745 /* This gives the user a way to test for new features in future by
1746 * trying to set them. */
1747 if (arg)
1748 return -EINVAL;
1749
1750 tun->set_features = features;
1751 netdev_update_features(tun->dev);
1752
1753 return 0;
1754 }
1755
1756 static void tun_detach_filter(struct tun_struct *tun, int n)
1757 {
1758 int i;
1759 struct tun_file *tfile;
1760
1761 for (i = 0; i < n; i++) {
1762 tfile = rtnl_dereference(tun->tfiles[i]);
1763 sk_detach_filter(tfile->socket.sk);
1764 }
1765
1766 tun->filter_attached = false;
1767 }
1768
1769 static int tun_attach_filter(struct tun_struct *tun)
1770 {
1771 int i, ret = 0;
1772 struct tun_file *tfile;
1773
1774 for (i = 0; i < tun->numqueues; i++) {
1775 tfile = rtnl_dereference(tun->tfiles[i]);
1776 ret = sk_attach_filter(&tun->fprog, tfile->socket.sk);
1777 if (ret) {
1778 tun_detach_filter(tun, i);
1779 return ret;
1780 }
1781 }
1782
1783 tun->filter_attached = true;
1784 return ret;
1785 }
1786
1787 static void tun_set_sndbuf(struct tun_struct *tun)
1788 {
1789 struct tun_file *tfile;
1790 int i;
1791
1792 for (i = 0; i < tun->numqueues; i++) {
1793 tfile = rtnl_dereference(tun->tfiles[i]);
1794 tfile->socket.sk->sk_sndbuf = tun->sndbuf;
1795 }
1796 }
1797
1798 static int tun_set_queue(struct file *file, struct ifreq *ifr)
1799 {
1800 struct tun_file *tfile = file->private_data;
1801 struct tun_struct *tun;
1802 int ret = 0;
1803
1804 rtnl_lock();
1805
1806 if (ifr->ifr_flags & IFF_ATTACH_QUEUE) {
1807 tun = tfile->detached;
1808 if (!tun) {
1809 ret = -EINVAL;
1810 goto unlock;
1811 }
1812 ret = security_tun_dev_attach_queue(tun->security);
1813 if (ret < 0)
1814 goto unlock;
1815 ret = tun_attach(tun, file, false);
1816 } else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
1817 tun = rtnl_dereference(tfile->tun);
1818 if (!tun || !(tun->flags & IFF_MULTI_QUEUE) || tfile->detached)
1819 ret = -EINVAL;
1820 else
1821 __tun_detach(tfile, false);
1822 } else
1823 ret = -EINVAL;
1824
1825 unlock:
1826 rtnl_unlock();
1827 return ret;
1828 }
1829
1830 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
1831 unsigned long arg, int ifreq_len)
1832 {
1833 struct tun_file *tfile = file->private_data;
1834 struct tun_struct *tun;
1835 void __user* argp = (void __user*)arg;
1836 struct ifreq ifr;
1837 kuid_t owner;
1838 kgid_t group;
1839 int sndbuf;
1840 int vnet_hdr_sz;
1841 unsigned int ifindex;
1842 int le;
1843 int ret;
1844
1845 if (cmd == TUNSETIFF || cmd == TUNSETQUEUE || _IOC_TYPE(cmd) == 0x89) {
1846 if (copy_from_user(&ifr, argp, ifreq_len))
1847 return -EFAULT;
1848 } else {
1849 memset(&ifr, 0, sizeof(ifr));
1850 }
1851 if (cmd == TUNGETFEATURES) {
1852 /* Currently this just means: "what IFF flags are valid?".
1853 * This is needed because we never checked for invalid flags on
1854 * TUNSETIFF.
1855 */
1856 return put_user(IFF_TUN | IFF_TAP | TUN_FEATURES,
1857 (unsigned int __user*)argp);
1858 } else if (cmd == TUNSETQUEUE)
1859 return tun_set_queue(file, &ifr);
1860
1861 ret = 0;
1862 rtnl_lock();
1863
1864 tun = __tun_get(tfile);
1865 if (cmd == TUNSETIFF && !tun) {
1866 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1867
1868 ret = tun_set_iff(tfile->net, file, &ifr);
1869
1870 if (ret)
1871 goto unlock;
1872
1873 if (copy_to_user(argp, &ifr, ifreq_len))
1874 ret = -EFAULT;
1875 goto unlock;
1876 }
1877 if (cmd == TUNSETIFINDEX) {
1878 ret = -EPERM;
1879 if (tun)
1880 goto unlock;
1881
1882 ret = -EFAULT;
1883 if (copy_from_user(&ifindex, argp, sizeof(ifindex)))
1884 goto unlock;
1885
1886 ret = 0;
1887 tfile->ifindex = ifindex;
1888 goto unlock;
1889 }
1890
1891 ret = -EBADFD;
1892 if (!tun)
1893 goto unlock;
1894
1895 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %u\n", cmd);
1896
1897 ret = 0;
1898 switch (cmd) {
1899 case TUNGETIFF:
1900 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1901
1902 if (tfile->detached)
1903 ifr.ifr_flags |= IFF_DETACH_QUEUE;
1904 if (!tfile->socket.sk->sk_filter)
1905 ifr.ifr_flags |= IFF_NOFILTER;
1906
1907 if (copy_to_user(argp, &ifr, ifreq_len))
1908 ret = -EFAULT;
1909 break;
1910
1911 case TUNSETNOCSUM:
1912 /* Disable/Enable checksum */
1913
1914 /* [unimplemented] */
1915 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n",
1916 arg ? "disabled" : "enabled");
1917 break;
1918
1919 case TUNSETPERSIST:
1920 /* Disable/Enable persist mode. Keep an extra reference to the
1921 * module to prevent the module being unprobed.
1922 */
1923 if (arg && !(tun->flags & IFF_PERSIST)) {
1924 tun->flags |= IFF_PERSIST;
1925 __module_get(THIS_MODULE);
1926 }
1927 if (!arg && (tun->flags & IFF_PERSIST)) {
1928 tun->flags &= ~IFF_PERSIST;
1929 module_put(THIS_MODULE);
1930 }
1931
1932 tun_debug(KERN_INFO, tun, "persist %s\n",
1933 arg ? "enabled" : "disabled");
1934 break;
1935
1936 case TUNSETOWNER:
1937 /* Set owner of the device */
1938 owner = make_kuid(current_user_ns(), arg);
1939 if (!uid_valid(owner)) {
1940 ret = -EINVAL;
1941 break;
1942 }
1943 tun->owner = owner;
1944 tun_debug(KERN_INFO, tun, "owner set to %u\n",
1945 from_kuid(&init_user_ns, tun->owner));
1946 break;
1947
1948 case TUNSETGROUP:
1949 /* Set group of the device */
1950 group = make_kgid(current_user_ns(), arg);
1951 if (!gid_valid(group)) {
1952 ret = -EINVAL;
1953 break;
1954 }
1955 tun->group = group;
1956 tun_debug(KERN_INFO, tun, "group set to %u\n",
1957 from_kgid(&init_user_ns, tun->group));
1958 break;
1959
1960 case TUNSETLINK:
1961 /* Only allow setting the type when the interface is down */
1962 if (tun->dev->flags & IFF_UP) {
1963 tun_debug(KERN_INFO, tun,
1964 "Linktype set failed because interface is up\n");
1965 ret = -EBUSY;
1966 } else {
1967 tun->dev->type = (int) arg;
1968 tun_debug(KERN_INFO, tun, "linktype set to %d\n",
1969 tun->dev->type);
1970 ret = 0;
1971 }
1972 break;
1973
1974 #ifdef TUN_DEBUG
1975 case TUNSETDEBUG:
1976 tun->debug = arg;
1977 break;
1978 #endif
1979 case TUNSETOFFLOAD:
1980 ret = set_offload(tun, arg);
1981 break;
1982
1983 case TUNSETTXFILTER:
1984 /* Can be set only for TAPs */
1985 ret = -EINVAL;
1986 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
1987 break;
1988 ret = update_filter(&tun->txflt, (void __user *)arg);
1989 break;
1990
1991 case SIOCGIFHWADDR:
1992 /* Get hw address */
1993 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
1994 ifr.ifr_hwaddr.sa_family = tun->dev->type;
1995 if (copy_to_user(argp, &ifr, ifreq_len))
1996 ret = -EFAULT;
1997 break;
1998
1999 case SIOCSIFHWADDR:
2000 /* Set hw address */
2001 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
2002 ifr.ifr_hwaddr.sa_data);
2003
2004 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
2005 break;
2006
2007 case TUNGETSNDBUF:
2008 sndbuf = tfile->socket.sk->sk_sndbuf;
2009 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
2010 ret = -EFAULT;
2011 break;
2012
2013 case TUNSETSNDBUF:
2014 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
2015 ret = -EFAULT;
2016 break;
2017 }
2018
2019 tun->sndbuf = sndbuf;
2020 tun_set_sndbuf(tun);
2021 break;
2022
2023 case TUNGETVNETHDRSZ:
2024 vnet_hdr_sz = tun->vnet_hdr_sz;
2025 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
2026 ret = -EFAULT;
2027 break;
2028
2029 case TUNSETVNETHDRSZ:
2030 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
2031 ret = -EFAULT;
2032 break;
2033 }
2034 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
2035 ret = -EINVAL;
2036 break;
2037 }
2038
2039 tun->vnet_hdr_sz = vnet_hdr_sz;
2040 break;
2041
2042 case TUNGETVNETLE:
2043 le = !!(tun->flags & TUN_VNET_LE);
2044 if (put_user(le, (int __user *)argp))
2045 ret = -EFAULT;
2046 break;
2047
2048 case TUNSETVNETLE:
2049 if (get_user(le, (int __user *)argp)) {
2050 ret = -EFAULT;
2051 break;
2052 }
2053 if (le)
2054 tun->flags |= TUN_VNET_LE;
2055 else
2056 tun->flags &= ~TUN_VNET_LE;
2057 break;
2058
2059 case TUNATTACHFILTER:
2060 /* Can be set only for TAPs */
2061 ret = -EINVAL;
2062 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2063 break;
2064 ret = -EFAULT;
2065 if (copy_from_user(&tun->fprog, argp, sizeof(tun->fprog)))
2066 break;
2067
2068 ret = tun_attach_filter(tun);
2069 break;
2070
2071 case TUNDETACHFILTER:
2072 /* Can be set only for TAPs */
2073 ret = -EINVAL;
2074 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2075 break;
2076 ret = 0;
2077 tun_detach_filter(tun, tun->numqueues);
2078 break;
2079
2080 case TUNGETFILTER:
2081 ret = -EINVAL;
2082 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2083 break;
2084 ret = -EFAULT;
2085 if (copy_to_user(argp, &tun->fprog, sizeof(tun->fprog)))
2086 break;
2087 ret = 0;
2088 break;
2089
2090 default:
2091 ret = -EINVAL;
2092 break;
2093 }
2094
2095 unlock:
2096 rtnl_unlock();
2097 if (tun)
2098 tun_put(tun);
2099 return ret;
2100 }
2101
2102 static long tun_chr_ioctl(struct file *file,
2103 unsigned int cmd, unsigned long arg)
2104 {
2105 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
2106 }
2107
2108 #ifdef CONFIG_COMPAT
2109 static long tun_chr_compat_ioctl(struct file *file,
2110 unsigned int cmd, unsigned long arg)
2111 {
2112 switch (cmd) {
2113 case TUNSETIFF:
2114 case TUNGETIFF:
2115 case TUNSETTXFILTER:
2116 case TUNGETSNDBUF:
2117 case TUNSETSNDBUF:
2118 case SIOCGIFHWADDR:
2119 case SIOCSIFHWADDR:
2120 arg = (unsigned long)compat_ptr(arg);
2121 break;
2122 default:
2123 arg = (compat_ulong_t)arg;
2124 break;
2125 }
2126
2127 /*
2128 * compat_ifreq is shorter than ifreq, so we must not access beyond
2129 * the end of that structure. All fields that are used in this
2130 * driver are compatible though, we don't need to convert the
2131 * contents.
2132 */
2133 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
2134 }
2135 #endif /* CONFIG_COMPAT */
2136
2137 static int tun_chr_fasync(int fd, struct file *file, int on)
2138 {
2139 struct tun_file *tfile = file->private_data;
2140 int ret;
2141
2142 if ((ret = fasync_helper(fd, file, on, &tfile->fasync)) < 0)
2143 goto out;
2144
2145 if (on) {
2146 __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
2147 tfile->flags |= TUN_FASYNC;
2148 } else
2149 tfile->flags &= ~TUN_FASYNC;
2150 ret = 0;
2151 out:
2152 return ret;
2153 }
2154
2155 static int tun_chr_open(struct inode *inode, struct file * file)
2156 {
2157 struct tun_file *tfile;
2158
2159 DBG1(KERN_INFO, "tunX: tun_chr_open\n");
2160
2161 tfile = (struct tun_file *)sk_alloc(&init_net, AF_UNSPEC, GFP_KERNEL,
2162 &tun_proto);
2163 if (!tfile)
2164 return -ENOMEM;
2165 RCU_INIT_POINTER(tfile->tun, NULL);
2166 tfile->net = get_net(current->nsproxy->net_ns);
2167 tfile->flags = 0;
2168 tfile->ifindex = 0;
2169
2170 init_waitqueue_head(&tfile->wq.wait);
2171 RCU_INIT_POINTER(tfile->socket.wq, &tfile->wq);
2172
2173 tfile->socket.file = file;
2174 tfile->socket.ops = &tun_socket_ops;
2175
2176 sock_init_data(&tfile->socket, &tfile->sk);
2177 sk_change_net(&tfile->sk, tfile->net);
2178
2179 tfile->sk.sk_write_space = tun_sock_write_space;
2180 tfile->sk.sk_sndbuf = INT_MAX;
2181
2182 file->private_data = tfile;
2183 set_bit(SOCK_EXTERNALLY_ALLOCATED, &tfile->socket.flags);
2184 INIT_LIST_HEAD(&tfile->next);
2185
2186 sock_set_flag(&tfile->sk, SOCK_ZEROCOPY);
2187
2188 return 0;
2189 }
2190
2191 static int tun_chr_close(struct inode *inode, struct file *file)
2192 {
2193 struct tun_file *tfile = file->private_data;
2194 struct net *net = tfile->net;
2195
2196 tun_detach(tfile, true);
2197 put_net(net);
2198
2199 return 0;
2200 }
2201
2202 #ifdef CONFIG_PROC_FS
2203 static void tun_chr_show_fdinfo(struct seq_file *m, struct file *f)
2204 {
2205 struct tun_struct *tun;
2206 struct ifreq ifr;
2207
2208 memset(&ifr, 0, sizeof(ifr));
2209
2210 rtnl_lock();
2211 tun = tun_get(f);
2212 if (tun)
2213 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
2214 rtnl_unlock();
2215
2216 if (tun)
2217 tun_put(tun);
2218
2219 seq_printf(m, "iff:\t%s\n", ifr.ifr_name);
2220 }
2221 #endif
2222
2223 static const struct file_operations tun_fops = {
2224 .owner = THIS_MODULE,
2225 .llseek = no_llseek,
2226 .read_iter = tun_chr_read_iter,
2227 .write_iter = tun_chr_write_iter,
2228 .poll = tun_chr_poll,
2229 .unlocked_ioctl = tun_chr_ioctl,
2230 #ifdef CONFIG_COMPAT
2231 .compat_ioctl = tun_chr_compat_ioctl,
2232 #endif
2233 .open = tun_chr_open,
2234 .release = tun_chr_close,
2235 .fasync = tun_chr_fasync,
2236 #ifdef CONFIG_PROC_FS
2237 .show_fdinfo = tun_chr_show_fdinfo,
2238 #endif
2239 };
2240
2241 static struct miscdevice tun_miscdev = {
2242 .minor = TUN_MINOR,
2243 .name = "tun",
2244 .nodename = "net/tun",
2245 .fops = &tun_fops,
2246 };
2247
2248 /* ethtool interface */
2249
2250 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
2251 {
2252 cmd->supported = 0;
2253 cmd->advertising = 0;
2254 ethtool_cmd_speed_set(cmd, SPEED_10);
2255 cmd->duplex = DUPLEX_FULL;
2256 cmd->port = PORT_TP;
2257 cmd->phy_address = 0;
2258 cmd->transceiver = XCVR_INTERNAL;
2259 cmd->autoneg = AUTONEG_DISABLE;
2260 cmd->maxtxpkt = 0;
2261 cmd->maxrxpkt = 0;
2262 return 0;
2263 }
2264
2265 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
2266 {
2267 struct tun_struct *tun = netdev_priv(dev);
2268
2269 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
2270 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
2271
2272 switch (tun->flags & TUN_TYPE_MASK) {
2273 case IFF_TUN:
2274 strlcpy(info->bus_info, "tun", sizeof(info->bus_info));
2275 break;
2276 case IFF_TAP:
2277 strlcpy(info->bus_info, "tap", sizeof(info->bus_info));
2278 break;
2279 }
2280 }
2281
2282 static u32 tun_get_msglevel(struct net_device *dev)
2283 {
2284 #ifdef TUN_DEBUG
2285 struct tun_struct *tun = netdev_priv(dev);
2286 return tun->debug;
2287 #else
2288 return -EOPNOTSUPP;
2289 #endif
2290 }
2291
2292 static void tun_set_msglevel(struct net_device *dev, u32 value)
2293 {
2294 #ifdef TUN_DEBUG
2295 struct tun_struct *tun = netdev_priv(dev);
2296 tun->debug = value;
2297 #endif
2298 }
2299
2300 static const struct ethtool_ops tun_ethtool_ops = {
2301 .get_settings = tun_get_settings,
2302 .get_drvinfo = tun_get_drvinfo,
2303 .get_msglevel = tun_get_msglevel,
2304 .set_msglevel = tun_set_msglevel,
2305 .get_link = ethtool_op_get_link,
2306 .get_ts_info = ethtool_op_get_ts_info,
2307 };
2308
2309
2310 static int __init tun_init(void)
2311 {
2312 int ret = 0;
2313
2314 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
2315 pr_info("%s\n", DRV_COPYRIGHT);
2316
2317 ret = rtnl_link_register(&tun_link_ops);
2318 if (ret) {
2319 pr_err("Can't register link_ops\n");
2320 goto err_linkops;
2321 }
2322
2323 ret = misc_register(&tun_miscdev);
2324 if (ret) {
2325 pr_err("Can't register misc device %d\n", TUN_MINOR);
2326 goto err_misc;
2327 }
2328 return 0;
2329 err_misc:
2330 rtnl_link_unregister(&tun_link_ops);
2331 err_linkops:
2332 return ret;
2333 }
2334
2335 static void tun_cleanup(void)
2336 {
2337 misc_deregister(&tun_miscdev);
2338 rtnl_link_unregister(&tun_link_ops);
2339 }
2340
2341 /* Get an underlying socket object from tun file. Returns error unless file is
2342 * attached to a device. The returned object works like a packet socket, it
2343 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
2344 * holding a reference to the file for as long as the socket is in use. */
2345 struct socket *tun_get_socket(struct file *file)
2346 {
2347 struct tun_file *tfile;
2348 if (file->f_op != &tun_fops)
2349 return ERR_PTR(-EINVAL);
2350 tfile = file->private_data;
2351 if (!tfile)
2352 return ERR_PTR(-EBADFD);
2353 return &tfile->socket;
2354 }
2355 EXPORT_SYMBOL_GPL(tun_get_socket);
2356
2357 module_init(tun_init);
2358 module_exit(tun_cleanup);
2359 MODULE_DESCRIPTION(DRV_DESCRIPTION);
2360 MODULE_AUTHOR(DRV_COPYRIGHT);
2361 MODULE_LICENSE("GPL");
2362 MODULE_ALIAS_MISCDEV(TUN_MINOR);
2363 MODULE_ALIAS("devname:net/tun");
Linux with added FPC-III support