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tun: fix transmit timestamp support
[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 #include <linux/seq_file.h>
73 #include <linux/uio.h>
74 #include <linux/skb_array.h>
75
76 #include <asm/uaccess.h>
77
78 /* Uncomment to enable debugging */
79 /* #define TUN_DEBUG 1 */
80
81 #ifdef TUN_DEBUG
82 static int debug;
83
84 #define tun_debug(level, tun, fmt, args...) \
85 do { \
86 if (tun->debug) \
87 netdev_printk(level, tun->dev, fmt, ##args); \
88 } while (0)
89 #define DBG1(level, fmt, args...) \
90 do { \
91 if (debug == 2) \
92 printk(level fmt, ##args); \
93 } while (0)
94 #else
95 #define tun_debug(level, tun, fmt, args...) \
96 do { \
97 if (0) \
98 netdev_printk(level, tun->dev, fmt, ##args); \
99 } while (0)
100 #define DBG1(level, fmt, args...) \
101 do { \
102 if (0) \
103 printk(level fmt, ##args); \
104 } while (0)
105 #endif
106
107 /* TUN device flags */
108
109 /* IFF_ATTACH_QUEUE is never stored in device flags,
110 * overload it to mean fasync when stored there.
111 */
112 #define TUN_FASYNC IFF_ATTACH_QUEUE
113 /* High bits in flags field are unused. */
114 #define TUN_VNET_LE 0x80000000
115 #define TUN_VNET_BE 0x40000000
116
117 #define TUN_FEATURES (IFF_NO_PI | IFF_ONE_QUEUE | IFF_VNET_HDR | \
118 IFF_MULTI_QUEUE)
119 #define GOODCOPY_LEN 128
120
121 #define FLT_EXACT_COUNT 8
122 struct tap_filter {
123 unsigned int count; /* Number of addrs. Zero means disabled */
124 u32 mask[2]; /* Mask of the hashed addrs */
125 unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN];
126 };
127
128 /* MAX_TAP_QUEUES 256 is chosen to allow rx/tx queues to be equal
129 * to max number of VCPUs in guest. */
130 #define MAX_TAP_QUEUES 256
131 #define MAX_TAP_FLOWS 4096
132
133 #define TUN_FLOW_EXPIRE (3 * HZ)
134
135 struct tun_pcpu_stats {
136 u64 rx_packets;
137 u64 rx_bytes;
138 u64 tx_packets;
139 u64 tx_bytes;
140 struct u64_stats_sync syncp;
141 u32 rx_dropped;
142 u32 tx_dropped;
143 u32 rx_frame_errors;
144 };
145
146 /* A tun_file connects an open character device to a tuntap netdevice. It
147 * also contains all socket related structures (except sock_fprog and tap_filter)
148 * to serve as one transmit queue for tuntap device. The sock_fprog and
149 * tap_filter were kept in tun_struct since they were used for filtering for the
150 * netdevice not for a specific queue (at least I didn't see the requirement for
151 * this).
152 *
153 * RCU usage:
154 * The tun_file and tun_struct are loosely coupled, the pointer from one to the
155 * other can only be read while rcu_read_lock or rtnl_lock is held.
156 */
157 struct tun_file {
158 struct sock sk;
159 struct socket socket;
160 struct socket_wq wq;
161 struct tun_struct __rcu *tun;
162 struct fasync_struct *fasync;
163 /* only used for fasnyc */
164 unsigned int flags;
165 union {
166 u16 queue_index;
167 unsigned int ifindex;
168 };
169 struct list_head next;
170 struct tun_struct *detached;
171 struct skb_array tx_array;
172 };
173
174 struct tun_flow_entry {
175 struct hlist_node hash_link;
176 struct rcu_head rcu;
177 struct tun_struct *tun;
178
179 u32 rxhash;
180 u32 rps_rxhash;
181 int queue_index;
182 unsigned long updated;
183 };
184
185 #define TUN_NUM_FLOW_ENTRIES 1024
186
187 /* Since the socket were moved to tun_file, to preserve the behavior of persist
188 * device, socket filter, sndbuf and vnet header size were restore when the
189 * file were attached to a persist device.
190 */
191 struct tun_struct {
192 struct tun_file __rcu *tfiles[MAX_TAP_QUEUES];
193 unsigned int numqueues;
194 unsigned int flags;
195 kuid_t owner;
196 kgid_t group;
197
198 struct net_device *dev;
199 netdev_features_t set_features;
200 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
201 NETIF_F_TSO6|NETIF_F_UFO)
202
203 int align;
204 int vnet_hdr_sz;
205 int sndbuf;
206 struct tap_filter txflt;
207 struct sock_fprog fprog;
208 /* protected by rtnl lock */
209 bool filter_attached;
210 #ifdef TUN_DEBUG
211 int debug;
212 #endif
213 spinlock_t lock;
214 struct hlist_head flows[TUN_NUM_FLOW_ENTRIES];
215 struct timer_list flow_gc_timer;
216 unsigned long ageing_time;
217 unsigned int numdisabled;
218 struct list_head disabled;
219 void *security;
220 u32 flow_count;
221 struct tun_pcpu_stats __percpu *pcpu_stats;
222 };
223
224 #ifdef CONFIG_TUN_VNET_CROSS_LE
225 static inline bool tun_legacy_is_little_endian(struct tun_struct *tun)
226 {
227 return tun->flags & TUN_VNET_BE ? false :
228 virtio_legacy_is_little_endian();
229 }
230
231 static long tun_get_vnet_be(struct tun_struct *tun, int __user *argp)
232 {
233 int be = !!(tun->flags & TUN_VNET_BE);
234
235 if (put_user(be, argp))
236 return -EFAULT;
237
238 return 0;
239 }
240
241 static long tun_set_vnet_be(struct tun_struct *tun, int __user *argp)
242 {
243 int be;
244
245 if (get_user(be, argp))
246 return -EFAULT;
247
248 if (be)
249 tun->flags |= TUN_VNET_BE;
250 else
251 tun->flags &= ~TUN_VNET_BE;
252
253 return 0;
254 }
255 #else
256 static inline bool tun_legacy_is_little_endian(struct tun_struct *tun)
257 {
258 return virtio_legacy_is_little_endian();
259 }
260
261 static long tun_get_vnet_be(struct tun_struct *tun, int __user *argp)
262 {
263 return -EINVAL;
264 }
265
266 static long tun_set_vnet_be(struct tun_struct *tun, int __user *argp)
267 {
268 return -EINVAL;
269 }
270 #endif /* CONFIG_TUN_VNET_CROSS_LE */
271
272 static inline bool tun_is_little_endian(struct tun_struct *tun)
273 {
274 return tun->flags & TUN_VNET_LE ||
275 tun_legacy_is_little_endian(tun);
276 }
277
278 static inline u16 tun16_to_cpu(struct tun_struct *tun, __virtio16 val)
279 {
280 return __virtio16_to_cpu(tun_is_little_endian(tun), val);
281 }
282
283 static inline __virtio16 cpu_to_tun16(struct tun_struct *tun, u16 val)
284 {
285 return __cpu_to_virtio16(tun_is_little_endian(tun), val);
286 }
287
288 static inline u32 tun_hashfn(u32 rxhash)
289 {
290 return rxhash & 0x3ff;
291 }
292
293 static struct tun_flow_entry *tun_flow_find(struct hlist_head *head, u32 rxhash)
294 {
295 struct tun_flow_entry *e;
296
297 hlist_for_each_entry_rcu(e, head, hash_link) {
298 if (e->rxhash == rxhash)
299 return e;
300 }
301 return NULL;
302 }
303
304 static struct tun_flow_entry *tun_flow_create(struct tun_struct *tun,
305 struct hlist_head *head,
306 u32 rxhash, u16 queue_index)
307 {
308 struct tun_flow_entry *e = kmalloc(sizeof(*e), GFP_ATOMIC);
309
310 if (e) {
311 tun_debug(KERN_INFO, tun, "create flow: hash %u index %u\n",
312 rxhash, queue_index);
313 e->updated = jiffies;
314 e->rxhash = rxhash;
315 e->rps_rxhash = 0;
316 e->queue_index = queue_index;
317 e->tun = tun;
318 hlist_add_head_rcu(&e->hash_link, head);
319 ++tun->flow_count;
320 }
321 return e;
322 }
323
324 static void tun_flow_delete(struct tun_struct *tun, struct tun_flow_entry *e)
325 {
326 tun_debug(KERN_INFO, tun, "delete flow: hash %u index %u\n",
327 e->rxhash, e->queue_index);
328 hlist_del_rcu(&e->hash_link);
329 kfree_rcu(e, rcu);
330 --tun->flow_count;
331 }
332
333 static void tun_flow_flush(struct tun_struct *tun)
334 {
335 int i;
336
337 spin_lock_bh(&tun->lock);
338 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
339 struct tun_flow_entry *e;
340 struct hlist_node *n;
341
342 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link)
343 tun_flow_delete(tun, e);
344 }
345 spin_unlock_bh(&tun->lock);
346 }
347
348 static void tun_flow_delete_by_queue(struct tun_struct *tun, u16 queue_index)
349 {
350 int i;
351
352 spin_lock_bh(&tun->lock);
353 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
354 struct tun_flow_entry *e;
355 struct hlist_node *n;
356
357 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
358 if (e->queue_index == queue_index)
359 tun_flow_delete(tun, e);
360 }
361 }
362 spin_unlock_bh(&tun->lock);
363 }
364
365 static void tun_flow_cleanup(unsigned long data)
366 {
367 struct tun_struct *tun = (struct tun_struct *)data;
368 unsigned long delay = tun->ageing_time;
369 unsigned long next_timer = jiffies + delay;
370 unsigned long count = 0;
371 int i;
372
373 tun_debug(KERN_INFO, tun, "tun_flow_cleanup\n");
374
375 spin_lock_bh(&tun->lock);
376 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
377 struct tun_flow_entry *e;
378 struct hlist_node *n;
379
380 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
381 unsigned long this_timer;
382 count++;
383 this_timer = e->updated + delay;
384 if (time_before_eq(this_timer, jiffies))
385 tun_flow_delete(tun, e);
386 else if (time_before(this_timer, next_timer))
387 next_timer = this_timer;
388 }
389 }
390
391 if (count)
392 mod_timer(&tun->flow_gc_timer, round_jiffies_up(next_timer));
393 spin_unlock_bh(&tun->lock);
394 }
395
396 static void tun_flow_update(struct tun_struct *tun, u32 rxhash,
397 struct tun_file *tfile)
398 {
399 struct hlist_head *head;
400 struct tun_flow_entry *e;
401 unsigned long delay = tun->ageing_time;
402 u16 queue_index = tfile->queue_index;
403
404 if (!rxhash)
405 return;
406 else
407 head = &tun->flows[tun_hashfn(rxhash)];
408
409 rcu_read_lock();
410
411 /* We may get a very small possibility of OOO during switching, not
412 * worth to optimize.*/
413 if (tun->numqueues == 1 || tfile->detached)
414 goto unlock;
415
416 e = tun_flow_find(head, rxhash);
417 if (likely(e)) {
418 /* TODO: keep queueing to old queue until it's empty? */
419 e->queue_index = queue_index;
420 e->updated = jiffies;
421 sock_rps_record_flow_hash(e->rps_rxhash);
422 } else {
423 spin_lock_bh(&tun->lock);
424 if (!tun_flow_find(head, rxhash) &&
425 tun->flow_count < MAX_TAP_FLOWS)
426 tun_flow_create(tun, head, rxhash, queue_index);
427
428 if (!timer_pending(&tun->flow_gc_timer))
429 mod_timer(&tun->flow_gc_timer,
430 round_jiffies_up(jiffies + delay));
431 spin_unlock_bh(&tun->lock);
432 }
433
434 unlock:
435 rcu_read_unlock();
436 }
437
438 /**
439 * Save the hash received in the stack receive path and update the
440 * flow_hash table accordingly.
441 */
442 static inline void tun_flow_save_rps_rxhash(struct tun_flow_entry *e, u32 hash)
443 {
444 if (unlikely(e->rps_rxhash != hash))
445 e->rps_rxhash = hash;
446 }
447
448 /* We try to identify a flow through its rxhash first. The reason that
449 * we do not check rxq no. is because some cards(e.g 82599), chooses
450 * the rxq based on the txq where the last packet of the flow comes. As
451 * the userspace application move between processors, we may get a
452 * different rxq no. here. If we could not get rxhash, then we would
453 * hope the rxq no. may help here.
454 */
455 static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb,
456 void *accel_priv, select_queue_fallback_t fallback)
457 {
458 struct tun_struct *tun = netdev_priv(dev);
459 struct tun_flow_entry *e;
460 u32 txq = 0;
461 u32 numqueues = 0;
462
463 rcu_read_lock();
464 numqueues = ACCESS_ONCE(tun->numqueues);
465
466 txq = skb_get_hash(skb);
467 if (txq) {
468 e = tun_flow_find(&tun->flows[tun_hashfn(txq)], txq);
469 if (e) {
470 tun_flow_save_rps_rxhash(e, txq);
471 txq = e->queue_index;
472 } else
473 /* use multiply and shift instead of expensive divide */
474 txq = ((u64)txq * numqueues) >> 32;
475 } else if (likely(skb_rx_queue_recorded(skb))) {
476 txq = skb_get_rx_queue(skb);
477 while (unlikely(txq >= numqueues))
478 txq -= numqueues;
479 }
480
481 rcu_read_unlock();
482 return txq;
483 }
484
485 static inline bool tun_not_capable(struct tun_struct *tun)
486 {
487 const struct cred *cred = current_cred();
488 struct net *net = dev_net(tun->dev);
489
490 return ((uid_valid(tun->owner) && !uid_eq(cred->euid, tun->owner)) ||
491 (gid_valid(tun->group) && !in_egroup_p(tun->group))) &&
492 !ns_capable(net->user_ns, CAP_NET_ADMIN);
493 }
494
495 static void tun_set_real_num_queues(struct tun_struct *tun)
496 {
497 netif_set_real_num_tx_queues(tun->dev, tun->numqueues);
498 netif_set_real_num_rx_queues(tun->dev, tun->numqueues);
499 }
500
501 static void tun_disable_queue(struct tun_struct *tun, struct tun_file *tfile)
502 {
503 tfile->detached = tun;
504 list_add_tail(&tfile->next, &tun->disabled);
505 ++tun->numdisabled;
506 }
507
508 static struct tun_struct *tun_enable_queue(struct tun_file *tfile)
509 {
510 struct tun_struct *tun = tfile->detached;
511
512 tfile->detached = NULL;
513 list_del_init(&tfile->next);
514 --tun->numdisabled;
515 return tun;
516 }
517
518 static void tun_queue_purge(struct tun_file *tfile)
519 {
520 struct sk_buff *skb;
521
522 while ((skb = skb_array_consume(&tfile->tx_array)) != NULL)
523 kfree_skb(skb);
524
525 skb_queue_purge(&tfile->sk.sk_error_queue);
526 }
527
528 static void __tun_detach(struct tun_file *tfile, bool clean)
529 {
530 struct tun_file *ntfile;
531 struct tun_struct *tun;
532
533 tun = rtnl_dereference(tfile->tun);
534
535 if (tun && !tfile->detached) {
536 u16 index = tfile->queue_index;
537 BUG_ON(index >= tun->numqueues);
538
539 rcu_assign_pointer(tun->tfiles[index],
540 tun->tfiles[tun->numqueues - 1]);
541 ntfile = rtnl_dereference(tun->tfiles[index]);
542 ntfile->queue_index = index;
543
544 --tun->numqueues;
545 if (clean) {
546 RCU_INIT_POINTER(tfile->tun, NULL);
547 sock_put(&tfile->sk);
548 } else
549 tun_disable_queue(tun, tfile);
550
551 synchronize_net();
552 tun_flow_delete_by_queue(tun, tun->numqueues + 1);
553 /* Drop read queue */
554 tun_queue_purge(tfile);
555 tun_set_real_num_queues(tun);
556 } else if (tfile->detached && clean) {
557 tun = tun_enable_queue(tfile);
558 sock_put(&tfile->sk);
559 }
560
561 if (clean) {
562 if (tun && tun->numqueues == 0 && tun->numdisabled == 0) {
563 netif_carrier_off(tun->dev);
564
565 if (!(tun->flags & IFF_PERSIST) &&
566 tun->dev->reg_state == NETREG_REGISTERED)
567 unregister_netdevice(tun->dev);
568 }
569 if (tun)
570 skb_array_cleanup(&tfile->tx_array);
571 sock_put(&tfile->sk);
572 }
573 }
574
575 static void tun_detach(struct tun_file *tfile, bool clean)
576 {
577 rtnl_lock();
578 __tun_detach(tfile, clean);
579 rtnl_unlock();
580 }
581
582 static void tun_detach_all(struct net_device *dev)
583 {
584 struct tun_struct *tun = netdev_priv(dev);
585 struct tun_file *tfile, *tmp;
586 int i, n = tun->numqueues;
587
588 for (i = 0; i < n; i++) {
589 tfile = rtnl_dereference(tun->tfiles[i]);
590 BUG_ON(!tfile);
591 tfile->socket.sk->sk_shutdown = RCV_SHUTDOWN;
592 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
593 RCU_INIT_POINTER(tfile->tun, NULL);
594 --tun->numqueues;
595 }
596 list_for_each_entry(tfile, &tun->disabled, next) {
597 tfile->socket.sk->sk_shutdown = RCV_SHUTDOWN;
598 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
599 RCU_INIT_POINTER(tfile->tun, NULL);
600 }
601 BUG_ON(tun->numqueues != 0);
602
603 synchronize_net();
604 for (i = 0; i < n; i++) {
605 tfile = rtnl_dereference(tun->tfiles[i]);
606 /* Drop read queue */
607 tun_queue_purge(tfile);
608 sock_put(&tfile->sk);
609 }
610 list_for_each_entry_safe(tfile, tmp, &tun->disabled, next) {
611 tun_enable_queue(tfile);
612 tun_queue_purge(tfile);
613 sock_put(&tfile->sk);
614 }
615 BUG_ON(tun->numdisabled != 0);
616
617 if (tun->flags & IFF_PERSIST)
618 module_put(THIS_MODULE);
619 }
620
621 static int tun_attach(struct tun_struct *tun, struct file *file, bool skip_filter)
622 {
623 struct tun_file *tfile = file->private_data;
624 struct net_device *dev = tun->dev;
625 int err;
626
627 err = security_tun_dev_attach(tfile->socket.sk, tun->security);
628 if (err < 0)
629 goto out;
630
631 err = -EINVAL;
632 if (rtnl_dereference(tfile->tun) && !tfile->detached)
633 goto out;
634
635 err = -EBUSY;
636 if (!(tun->flags & IFF_MULTI_QUEUE) && tun->numqueues == 1)
637 goto out;
638
639 err = -E2BIG;
640 if (!tfile->detached &&
641 tun->numqueues + tun->numdisabled == MAX_TAP_QUEUES)
642 goto out;
643
644 err = 0;
645
646 /* Re-attach the filter to persist device */
647 if (!skip_filter && (tun->filter_attached == true)) {
648 lock_sock(tfile->socket.sk);
649 err = sk_attach_filter(&tun->fprog, tfile->socket.sk);
650 release_sock(tfile->socket.sk);
651 if (!err)
652 goto out;
653 }
654
655 if (!tfile->detached &&
656 skb_array_init(&tfile->tx_array, dev->tx_queue_len, GFP_KERNEL)) {
657 err = -ENOMEM;
658 goto out;
659 }
660
661 tfile->queue_index = tun->numqueues;
662 tfile->socket.sk->sk_shutdown &= ~RCV_SHUTDOWN;
663 rcu_assign_pointer(tfile->tun, tun);
664 rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile);
665 tun->numqueues++;
666
667 if (tfile->detached)
668 tun_enable_queue(tfile);
669 else
670 sock_hold(&tfile->sk);
671
672 tun_set_real_num_queues(tun);
673
674 /* device is allowed to go away first, so no need to hold extra
675 * refcnt.
676 */
677
678 out:
679 return err;
680 }
681
682 static struct tun_struct *__tun_get(struct tun_file *tfile)
683 {
684 struct tun_struct *tun;
685
686 rcu_read_lock();
687 tun = rcu_dereference(tfile->tun);
688 if (tun)
689 dev_hold(tun->dev);
690 rcu_read_unlock();
691
692 return tun;
693 }
694
695 static struct tun_struct *tun_get(struct file *file)
696 {
697 return __tun_get(file->private_data);
698 }
699
700 static void tun_put(struct tun_struct *tun)
701 {
702 dev_put(tun->dev);
703 }
704
705 /* TAP filtering */
706 static void addr_hash_set(u32 *mask, const u8 *addr)
707 {
708 int n = ether_crc(ETH_ALEN, addr) >> 26;
709 mask[n >> 5] |= (1 << (n & 31));
710 }
711
712 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
713 {
714 int n = ether_crc(ETH_ALEN, addr) >> 26;
715 return mask[n >> 5] & (1 << (n & 31));
716 }
717
718 static int update_filter(struct tap_filter *filter, void __user *arg)
719 {
720 struct { u8 u[ETH_ALEN]; } *addr;
721 struct tun_filter uf;
722 int err, alen, n, nexact;
723
724 if (copy_from_user(&uf, arg, sizeof(uf)))
725 return -EFAULT;
726
727 if (!uf.count) {
728 /* Disabled */
729 filter->count = 0;
730 return 0;
731 }
732
733 alen = ETH_ALEN * uf.count;
734 addr = kmalloc(alen, GFP_KERNEL);
735 if (!addr)
736 return -ENOMEM;
737
738 if (copy_from_user(addr, arg + sizeof(uf), alen)) {
739 err = -EFAULT;
740 goto done;
741 }
742
743 /* The filter is updated without holding any locks. Which is
744 * perfectly safe. We disable it first and in the worst
745 * case we'll accept a few undesired packets. */
746 filter->count = 0;
747 wmb();
748
749 /* Use first set of addresses as an exact filter */
750 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
751 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
752
753 nexact = n;
754
755 /* Remaining multicast addresses are hashed,
756 * unicast will leave the filter disabled. */
757 memset(filter->mask, 0, sizeof(filter->mask));
758 for (; n < uf.count; n++) {
759 if (!is_multicast_ether_addr(addr[n].u)) {
760 err = 0; /* no filter */
761 goto done;
762 }
763 addr_hash_set(filter->mask, addr[n].u);
764 }
765
766 /* For ALLMULTI just set the mask to all ones.
767 * This overrides the mask populated above. */
768 if ((uf.flags & TUN_FLT_ALLMULTI))
769 memset(filter->mask, ~0, sizeof(filter->mask));
770
771 /* Now enable the filter */
772 wmb();
773 filter->count = nexact;
774
775 /* Return the number of exact filters */
776 err = nexact;
777
778 done:
779 kfree(addr);
780 return err;
781 }
782
783 /* Returns: 0 - drop, !=0 - accept */
784 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
785 {
786 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
787 * at this point. */
788 struct ethhdr *eh = (struct ethhdr *) skb->data;
789 int i;
790
791 /* Exact match */
792 for (i = 0; i < filter->count; i++)
793 if (ether_addr_equal(eh->h_dest, filter->addr[i]))
794 return 1;
795
796 /* Inexact match (multicast only) */
797 if (is_multicast_ether_addr(eh->h_dest))
798 return addr_hash_test(filter->mask, eh->h_dest);
799
800 return 0;
801 }
802
803 /*
804 * Checks whether the packet is accepted or not.
805 * Returns: 0 - drop, !=0 - accept
806 */
807 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
808 {
809 if (!filter->count)
810 return 1;
811
812 return run_filter(filter, skb);
813 }
814
815 /* Network device part of the driver */
816
817 static const struct ethtool_ops tun_ethtool_ops;
818
819 /* Net device detach from fd. */
820 static void tun_net_uninit(struct net_device *dev)
821 {
822 tun_detach_all(dev);
823 }
824
825 /* Net device open. */
826 static int tun_net_open(struct net_device *dev)
827 {
828 netif_tx_start_all_queues(dev);
829 return 0;
830 }
831
832 /* Net device close. */
833 static int tun_net_close(struct net_device *dev)
834 {
835 netif_tx_stop_all_queues(dev);
836 return 0;
837 }
838
839 /* Net device start xmit */
840 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
841 {
842 struct tun_struct *tun = netdev_priv(dev);
843 int txq = skb->queue_mapping;
844 struct tun_file *tfile;
845 u32 numqueues = 0;
846
847 rcu_read_lock();
848 tfile = rcu_dereference(tun->tfiles[txq]);
849 numqueues = ACCESS_ONCE(tun->numqueues);
850
851 /* Drop packet if interface is not attached */
852 if (txq >= numqueues)
853 goto drop;
854
855 #ifdef CONFIG_RPS
856 if (numqueues == 1 && static_key_false(&rps_needed)) {
857 /* Select queue was not called for the skbuff, so we extract the
858 * RPS hash and save it into the flow_table here.
859 */
860 __u32 rxhash;
861
862 rxhash = skb_get_hash(skb);
863 if (rxhash) {
864 struct tun_flow_entry *e;
865 e = tun_flow_find(&tun->flows[tun_hashfn(rxhash)],
866 rxhash);
867 if (e)
868 tun_flow_save_rps_rxhash(e, rxhash);
869 }
870 }
871 #endif
872
873 tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len);
874
875 BUG_ON(!tfile);
876
877 /* Drop if the filter does not like it.
878 * This is a noop if the filter is disabled.
879 * Filter can be enabled only for the TAP devices. */
880 if (!check_filter(&tun->txflt, skb))
881 goto drop;
882
883 if (tfile->socket.sk->sk_filter &&
884 sk_filter(tfile->socket.sk, skb))
885 goto drop;
886
887 /* Limit the number of packets queued by dividing txq length with the
888 * number of queues.
889 */
890 if (skb_queue_len(&tfile->socket.sk->sk_receive_queue) * numqueues
891 >= dev->tx_queue_len)
892 goto drop;
893
894 if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
895 goto drop;
896
897 skb_tx_timestamp(skb);
898
899 /* Orphan the skb - required as we might hang on to it
900 * for indefinite time.
901 */
902 skb_orphan(skb);
903
904 nf_reset(skb);
905
906 if (skb_array_produce(&tfile->tx_array, skb))
907 goto drop;
908
909 /* Notify and wake up reader process */
910 if (tfile->flags & TUN_FASYNC)
911 kill_fasync(&tfile->fasync, SIGIO, POLL_IN);
912 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
913
914 rcu_read_unlock();
915 return NETDEV_TX_OK;
916
917 drop:
918 this_cpu_inc(tun->pcpu_stats->tx_dropped);
919 skb_tx_error(skb);
920 kfree_skb(skb);
921 rcu_read_unlock();
922 return NET_XMIT_DROP;
923 }
924
925 static void tun_net_mclist(struct net_device *dev)
926 {
927 /*
928 * This callback is supposed to deal with mc filter in
929 * _rx_ path and has nothing to do with the _tx_ path.
930 * In rx path we always accept everything userspace gives us.
931 */
932 }
933
934 #define MIN_MTU 68
935 #define MAX_MTU 65535
936
937 static int
938 tun_net_change_mtu(struct net_device *dev, int new_mtu)
939 {
940 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
941 return -EINVAL;
942 dev->mtu = new_mtu;
943 return 0;
944 }
945
946 static netdev_features_t tun_net_fix_features(struct net_device *dev,
947 netdev_features_t features)
948 {
949 struct tun_struct *tun = netdev_priv(dev);
950
951 return (features & tun->set_features) | (features & ~TUN_USER_FEATURES);
952 }
953 #ifdef CONFIG_NET_POLL_CONTROLLER
954 static void tun_poll_controller(struct net_device *dev)
955 {
956 /*
957 * Tun only receives frames when:
958 * 1) the char device endpoint gets data from user space
959 * 2) the tun socket gets a sendmsg call from user space
960 * Since both of those are synchronous operations, we are guaranteed
961 * never to have pending data when we poll for it
962 * so there is nothing to do here but return.
963 * We need this though so netpoll recognizes us as an interface that
964 * supports polling, which enables bridge devices in virt setups to
965 * still use netconsole
966 */
967 return;
968 }
969 #endif
970
971 static void tun_set_headroom(struct net_device *dev, int new_hr)
972 {
973 struct tun_struct *tun = netdev_priv(dev);
974
975 if (new_hr < NET_SKB_PAD)
976 new_hr = NET_SKB_PAD;
977
978 tun->align = new_hr;
979 }
980
981 static struct rtnl_link_stats64 *
982 tun_net_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
983 {
984 u32 rx_dropped = 0, tx_dropped = 0, rx_frame_errors = 0;
985 struct tun_struct *tun = netdev_priv(dev);
986 struct tun_pcpu_stats *p;
987 int i;
988
989 for_each_possible_cpu(i) {
990 u64 rxpackets, rxbytes, txpackets, txbytes;
991 unsigned int start;
992
993 p = per_cpu_ptr(tun->pcpu_stats, i);
994 do {
995 start = u64_stats_fetch_begin(&p->syncp);
996 rxpackets = p->rx_packets;
997 rxbytes = p->rx_bytes;
998 txpackets = p->tx_packets;
999 txbytes = p->tx_bytes;
1000 } while (u64_stats_fetch_retry(&p->syncp, start));
1001
1002 stats->rx_packets += rxpackets;
1003 stats->rx_bytes += rxbytes;
1004 stats->tx_packets += txpackets;
1005 stats->tx_bytes += txbytes;
1006
1007 /* u32 counters */
1008 rx_dropped += p->rx_dropped;
1009 rx_frame_errors += p->rx_frame_errors;
1010 tx_dropped += p->tx_dropped;
1011 }
1012 stats->rx_dropped = rx_dropped;
1013 stats->rx_frame_errors = rx_frame_errors;
1014 stats->tx_dropped = tx_dropped;
1015 return stats;
1016 }
1017
1018 static const struct net_device_ops tun_netdev_ops = {
1019 .ndo_uninit = tun_net_uninit,
1020 .ndo_open = tun_net_open,
1021 .ndo_stop = tun_net_close,
1022 .ndo_start_xmit = tun_net_xmit,
1023 .ndo_change_mtu = tun_net_change_mtu,
1024 .ndo_fix_features = tun_net_fix_features,
1025 .ndo_select_queue = tun_select_queue,
1026 #ifdef CONFIG_NET_POLL_CONTROLLER
1027 .ndo_poll_controller = tun_poll_controller,
1028 #endif
1029 .ndo_set_rx_headroom = tun_set_headroom,
1030 .ndo_get_stats64 = tun_net_get_stats64,
1031 };
1032
1033 static const struct net_device_ops tap_netdev_ops = {
1034 .ndo_uninit = tun_net_uninit,
1035 .ndo_open = tun_net_open,
1036 .ndo_stop = tun_net_close,
1037 .ndo_start_xmit = tun_net_xmit,
1038 .ndo_change_mtu = tun_net_change_mtu,
1039 .ndo_fix_features = tun_net_fix_features,
1040 .ndo_set_rx_mode = tun_net_mclist,
1041 .ndo_set_mac_address = eth_mac_addr,
1042 .ndo_validate_addr = eth_validate_addr,
1043 .ndo_select_queue = tun_select_queue,
1044 #ifdef CONFIG_NET_POLL_CONTROLLER
1045 .ndo_poll_controller = tun_poll_controller,
1046 #endif
1047 .ndo_features_check = passthru_features_check,
1048 .ndo_set_rx_headroom = tun_set_headroom,
1049 .ndo_get_stats64 = tun_net_get_stats64,
1050 };
1051
1052 static void tun_flow_init(struct tun_struct *tun)
1053 {
1054 int i;
1055
1056 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++)
1057 INIT_HLIST_HEAD(&tun->flows[i]);
1058
1059 tun->ageing_time = TUN_FLOW_EXPIRE;
1060 setup_timer(&tun->flow_gc_timer, tun_flow_cleanup, (unsigned long)tun);
1061 mod_timer(&tun->flow_gc_timer,
1062 round_jiffies_up(jiffies + tun->ageing_time));
1063 }
1064
1065 static void tun_flow_uninit(struct tun_struct *tun)
1066 {
1067 del_timer_sync(&tun->flow_gc_timer);
1068 tun_flow_flush(tun);
1069 }
1070
1071 /* Initialize net device. */
1072 static void tun_net_init(struct net_device *dev)
1073 {
1074 struct tun_struct *tun = netdev_priv(dev);
1075
1076 switch (tun->flags & TUN_TYPE_MASK) {
1077 case IFF_TUN:
1078 dev->netdev_ops = &tun_netdev_ops;
1079
1080 /* Point-to-Point TUN Device */
1081 dev->hard_header_len = 0;
1082 dev->addr_len = 0;
1083 dev->mtu = 1500;
1084
1085 /* Zero header length */
1086 dev->type = ARPHRD_NONE;
1087 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1088 break;
1089
1090 case IFF_TAP:
1091 dev->netdev_ops = &tap_netdev_ops;
1092 /* Ethernet TAP Device */
1093 ether_setup(dev);
1094 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1095 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1096
1097 eth_hw_addr_random(dev);
1098
1099 break;
1100 }
1101 }
1102
1103 /* Character device part */
1104
1105 /* Poll */
1106 static unsigned int tun_chr_poll(struct file *file, poll_table *wait)
1107 {
1108 struct tun_file *tfile = file->private_data;
1109 struct tun_struct *tun = __tun_get(tfile);
1110 struct sock *sk;
1111 unsigned int mask = 0;
1112
1113 if (!tun)
1114 return POLLERR;
1115
1116 sk = tfile->socket.sk;
1117
1118 tun_debug(KERN_INFO, tun, "tun_chr_poll\n");
1119
1120 poll_wait(file, sk_sleep(sk), wait);
1121
1122 if (!skb_array_empty(&tfile->tx_array))
1123 mask |= POLLIN | POLLRDNORM;
1124
1125 if (sock_writeable(sk) ||
1126 (!test_and_set_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
1127 sock_writeable(sk)))
1128 mask |= POLLOUT | POLLWRNORM;
1129
1130 if (tun->dev->reg_state != NETREG_REGISTERED)
1131 mask = POLLERR;
1132
1133 tun_put(tun);
1134 return mask;
1135 }
1136
1137 /* prepad is the amount to reserve at front. len is length after that.
1138 * linear is a hint as to how much to copy (usually headers). */
1139 static struct sk_buff *tun_alloc_skb(struct tun_file *tfile,
1140 size_t prepad, size_t len,
1141 size_t linear, int noblock)
1142 {
1143 struct sock *sk = tfile->socket.sk;
1144 struct sk_buff *skb;
1145 int err;
1146
1147 /* Under a page? Don't bother with paged skb. */
1148 if (prepad + len < PAGE_SIZE || !linear)
1149 linear = len;
1150
1151 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
1152 &err, 0);
1153 if (!skb)
1154 return ERR_PTR(err);
1155
1156 skb_reserve(skb, prepad);
1157 skb_put(skb, linear);
1158 skb->data_len = len - linear;
1159 skb->len += len - linear;
1160
1161 return skb;
1162 }
1163
1164 /* Get packet from user space buffer */
1165 static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
1166 void *msg_control, struct iov_iter *from,
1167 int noblock)
1168 {
1169 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
1170 struct sk_buff *skb;
1171 size_t total_len = iov_iter_count(from);
1172 size_t len = total_len, align = tun->align, linear;
1173 struct virtio_net_hdr gso = { 0 };
1174 struct tun_pcpu_stats *stats;
1175 int good_linear;
1176 int copylen;
1177 bool zerocopy = false;
1178 int err;
1179 u32 rxhash;
1180 ssize_t n;
1181
1182 if (!(tun->dev->flags & IFF_UP))
1183 return -EIO;
1184
1185 if (!(tun->flags & IFF_NO_PI)) {
1186 if (len < sizeof(pi))
1187 return -EINVAL;
1188 len -= sizeof(pi);
1189
1190 n = copy_from_iter(&pi, sizeof(pi), from);
1191 if (n != sizeof(pi))
1192 return -EFAULT;
1193 }
1194
1195 if (tun->flags & IFF_VNET_HDR) {
1196 if (len < tun->vnet_hdr_sz)
1197 return -EINVAL;
1198 len -= tun->vnet_hdr_sz;
1199
1200 n = copy_from_iter(&gso, sizeof(gso), from);
1201 if (n != sizeof(gso))
1202 return -EFAULT;
1203
1204 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
1205 tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2 > tun16_to_cpu(tun, gso.hdr_len))
1206 gso.hdr_len = cpu_to_tun16(tun, tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2);
1207
1208 if (tun16_to_cpu(tun, gso.hdr_len) > len)
1209 return -EINVAL;
1210 iov_iter_advance(from, tun->vnet_hdr_sz - sizeof(gso));
1211 }
1212
1213 if ((tun->flags & TUN_TYPE_MASK) == IFF_TAP) {
1214 align += NET_IP_ALIGN;
1215 if (unlikely(len < ETH_HLEN ||
1216 (gso.hdr_len && tun16_to_cpu(tun, gso.hdr_len) < ETH_HLEN)))
1217 return -EINVAL;
1218 }
1219
1220 good_linear = SKB_MAX_HEAD(align);
1221
1222 if (msg_control) {
1223 struct iov_iter i = *from;
1224
1225 /* There are 256 bytes to be copied in skb, so there is
1226 * enough room for skb expand head in case it is used.
1227 * The rest of the buffer is mapped from userspace.
1228 */
1229 copylen = gso.hdr_len ? tun16_to_cpu(tun, gso.hdr_len) : GOODCOPY_LEN;
1230 if (copylen > good_linear)
1231 copylen = good_linear;
1232 linear = copylen;
1233 iov_iter_advance(&i, copylen);
1234 if (iov_iter_npages(&i, INT_MAX) <= MAX_SKB_FRAGS)
1235 zerocopy = true;
1236 }
1237
1238 if (!zerocopy) {
1239 copylen = len;
1240 if (tun16_to_cpu(tun, gso.hdr_len) > good_linear)
1241 linear = good_linear;
1242 else
1243 linear = tun16_to_cpu(tun, gso.hdr_len);
1244 }
1245
1246 skb = tun_alloc_skb(tfile, align, copylen, linear, noblock);
1247 if (IS_ERR(skb)) {
1248 if (PTR_ERR(skb) != -EAGAIN)
1249 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1250 return PTR_ERR(skb);
1251 }
1252
1253 if (zerocopy)
1254 err = zerocopy_sg_from_iter(skb, from);
1255 else {
1256 err = skb_copy_datagram_from_iter(skb, 0, from, len);
1257 if (!err && msg_control) {
1258 struct ubuf_info *uarg = msg_control;
1259 uarg->callback(uarg, false);
1260 }
1261 }
1262
1263 if (err) {
1264 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1265 kfree_skb(skb);
1266 return -EFAULT;
1267 }
1268
1269 err = virtio_net_hdr_to_skb(skb, &gso, tun_is_little_endian(tun));
1270 if (err) {
1271 this_cpu_inc(tun->pcpu_stats->rx_frame_errors);
1272 kfree_skb(skb);
1273 return -EINVAL;
1274 }
1275
1276 switch (tun->flags & TUN_TYPE_MASK) {
1277 case IFF_TUN:
1278 if (tun->flags & IFF_NO_PI) {
1279 switch (skb->data[0] & 0xf0) {
1280 case 0x40:
1281 pi.proto = htons(ETH_P_IP);
1282 break;
1283 case 0x60:
1284 pi.proto = htons(ETH_P_IPV6);
1285 break;
1286 default:
1287 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1288 kfree_skb(skb);
1289 return -EINVAL;
1290 }
1291 }
1292
1293 skb_reset_mac_header(skb);
1294 skb->protocol = pi.proto;
1295 skb->dev = tun->dev;
1296 break;
1297 case IFF_TAP:
1298 skb->protocol = eth_type_trans(skb, tun->dev);
1299 break;
1300 }
1301
1302 /* copy skb_ubuf_info for callback when skb has no error */
1303 if (zerocopy) {
1304 skb_shinfo(skb)->destructor_arg = msg_control;
1305 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1306 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
1307 }
1308
1309 skb_reset_network_header(skb);
1310 skb_probe_transport_header(skb, 0);
1311
1312 rxhash = skb_get_hash(skb);
1313 netif_rx_ni(skb);
1314
1315 stats = get_cpu_ptr(tun->pcpu_stats);
1316 u64_stats_update_begin(&stats->syncp);
1317 stats->rx_packets++;
1318 stats->rx_bytes += len;
1319 u64_stats_update_end(&stats->syncp);
1320 put_cpu_ptr(stats);
1321
1322 tun_flow_update(tun, rxhash, tfile);
1323 return total_len;
1324 }
1325
1326 static ssize_t tun_chr_write_iter(struct kiocb *iocb, struct iov_iter *from)
1327 {
1328 struct file *file = iocb->ki_filp;
1329 struct tun_struct *tun = tun_get(file);
1330 struct tun_file *tfile = file->private_data;
1331 ssize_t result;
1332
1333 if (!tun)
1334 return -EBADFD;
1335
1336 result = tun_get_user(tun, tfile, NULL, from, file->f_flags & O_NONBLOCK);
1337
1338 tun_put(tun);
1339 return result;
1340 }
1341
1342 /* Put packet to the user space buffer */
1343 static ssize_t tun_put_user(struct tun_struct *tun,
1344 struct tun_file *tfile,
1345 struct sk_buff *skb,
1346 struct iov_iter *iter)
1347 {
1348 struct tun_pi pi = { 0, skb->protocol };
1349 struct tun_pcpu_stats *stats;
1350 ssize_t total;
1351 int vlan_offset = 0;
1352 int vlan_hlen = 0;
1353 int vnet_hdr_sz = 0;
1354
1355 if (skb_vlan_tag_present(skb))
1356 vlan_hlen = VLAN_HLEN;
1357
1358 if (tun->flags & IFF_VNET_HDR)
1359 vnet_hdr_sz = tun->vnet_hdr_sz;
1360
1361 total = skb->len + vlan_hlen + vnet_hdr_sz;
1362
1363 if (!(tun->flags & IFF_NO_PI)) {
1364 if (iov_iter_count(iter) < sizeof(pi))
1365 return -EINVAL;
1366
1367 total += sizeof(pi);
1368 if (iov_iter_count(iter) < total) {
1369 /* Packet will be striped */
1370 pi.flags |= TUN_PKT_STRIP;
1371 }
1372
1373 if (copy_to_iter(&pi, sizeof(pi), iter) != sizeof(pi))
1374 return -EFAULT;
1375 }
1376
1377 if (vnet_hdr_sz) {
1378 struct virtio_net_hdr gso = { 0 }; /* no info leak */
1379 int ret;
1380
1381 if (iov_iter_count(iter) < vnet_hdr_sz)
1382 return -EINVAL;
1383
1384 ret = virtio_net_hdr_from_skb(skb, &gso,
1385 tun_is_little_endian(tun));
1386 if (ret) {
1387 struct skb_shared_info *sinfo = skb_shinfo(skb);
1388 pr_err("unexpected GSO type: "
1389 "0x%x, gso_size %d, hdr_len %d\n",
1390 sinfo->gso_type, tun16_to_cpu(tun, gso.gso_size),
1391 tun16_to_cpu(tun, gso.hdr_len));
1392 print_hex_dump(KERN_ERR, "tun: ",
1393 DUMP_PREFIX_NONE,
1394 16, 1, skb->head,
1395 min((int)tun16_to_cpu(tun, gso.hdr_len), 64), true);
1396 WARN_ON_ONCE(1);
1397 return -EINVAL;
1398 }
1399
1400 if (copy_to_iter(&gso, sizeof(gso), iter) != sizeof(gso))
1401 return -EFAULT;
1402
1403 iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso));
1404 }
1405
1406 if (vlan_hlen) {
1407 int ret;
1408 struct {
1409 __be16 h_vlan_proto;
1410 __be16 h_vlan_TCI;
1411 } veth;
1412
1413 veth.h_vlan_proto = skb->vlan_proto;
1414 veth.h_vlan_TCI = htons(skb_vlan_tag_get(skb));
1415
1416 vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);
1417
1418 ret = skb_copy_datagram_iter(skb, 0, iter, vlan_offset);
1419 if (ret || !iov_iter_count(iter))
1420 goto done;
1421
1422 ret = copy_to_iter(&veth, sizeof(veth), iter);
1423 if (ret != sizeof(veth) || !iov_iter_count(iter))
1424 goto done;
1425 }
1426
1427 skb_copy_datagram_iter(skb, vlan_offset, iter, skb->len - vlan_offset);
1428
1429 done:
1430 /* caller is in process context, */
1431 stats = get_cpu_ptr(tun->pcpu_stats);
1432 u64_stats_update_begin(&stats->syncp);
1433 stats->tx_packets++;
1434 stats->tx_bytes += skb->len + vlan_hlen;
1435 u64_stats_update_end(&stats->syncp);
1436 put_cpu_ptr(tun->pcpu_stats);
1437
1438 return total;
1439 }
1440
1441 static struct sk_buff *tun_ring_recv(struct tun_file *tfile, int noblock,
1442 int *err)
1443 {
1444 DECLARE_WAITQUEUE(wait, current);
1445 struct sk_buff *skb = NULL;
1446 int error = 0;
1447
1448 skb = skb_array_consume(&tfile->tx_array);
1449 if (skb)
1450 goto out;
1451 if (noblock) {
1452 error = -EAGAIN;
1453 goto out;
1454 }
1455
1456 add_wait_queue(&tfile->wq.wait, &wait);
1457 current->state = TASK_INTERRUPTIBLE;
1458
1459 while (1) {
1460 skb = skb_array_consume(&tfile->tx_array);
1461 if (skb)
1462 break;
1463 if (signal_pending(current)) {
1464 error = -ERESTARTSYS;
1465 break;
1466 }
1467 if (tfile->socket.sk->sk_shutdown & RCV_SHUTDOWN) {
1468 error = -EFAULT;
1469 break;
1470 }
1471
1472 schedule();
1473 }
1474
1475 current->state = TASK_RUNNING;
1476 remove_wait_queue(&tfile->wq.wait, &wait);
1477
1478 out:
1479 *err = error;
1480 return skb;
1481 }
1482
1483 static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
1484 struct iov_iter *to,
1485 int noblock)
1486 {
1487 struct sk_buff *skb;
1488 ssize_t ret;
1489 int err;
1490
1491 tun_debug(KERN_INFO, tun, "tun_do_read\n");
1492
1493 if (!iov_iter_count(to))
1494 return 0;
1495
1496 /* Read frames from ring */
1497 skb = tun_ring_recv(tfile, noblock, &err);
1498 if (!skb)
1499 return err;
1500
1501 ret = tun_put_user(tun, tfile, skb, to);
1502 if (unlikely(ret < 0))
1503 kfree_skb(skb);
1504 else
1505 consume_skb(skb);
1506
1507 return ret;
1508 }
1509
1510 static ssize_t tun_chr_read_iter(struct kiocb *iocb, struct iov_iter *to)
1511 {
1512 struct file *file = iocb->ki_filp;
1513 struct tun_file *tfile = file->private_data;
1514 struct tun_struct *tun = __tun_get(tfile);
1515 ssize_t len = iov_iter_count(to), ret;
1516
1517 if (!tun)
1518 return -EBADFD;
1519 ret = tun_do_read(tun, tfile, to, file->f_flags & O_NONBLOCK);
1520 ret = min_t(ssize_t, ret, len);
1521 if (ret > 0)
1522 iocb->ki_pos = ret;
1523 tun_put(tun);
1524 return ret;
1525 }
1526
1527 static void tun_free_netdev(struct net_device *dev)
1528 {
1529 struct tun_struct *tun = netdev_priv(dev);
1530
1531 BUG_ON(!(list_empty(&tun->disabled)));
1532 free_percpu(tun->pcpu_stats);
1533 tun_flow_uninit(tun);
1534 security_tun_dev_free_security(tun->security);
1535 free_netdev(dev);
1536 }
1537
1538 static void tun_setup(struct net_device *dev)
1539 {
1540 struct tun_struct *tun = netdev_priv(dev);
1541
1542 tun->owner = INVALID_UID;
1543 tun->group = INVALID_GID;
1544
1545 dev->ethtool_ops = &tun_ethtool_ops;
1546 dev->destructor = tun_free_netdev;
1547 /* We prefer our own queue length */
1548 dev->tx_queue_len = TUN_READQ_SIZE;
1549 }
1550
1551 /* Trivial set of netlink ops to allow deleting tun or tap
1552 * device with netlink.
1553 */
1554 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
1555 {
1556 return -EINVAL;
1557 }
1558
1559 static struct rtnl_link_ops tun_link_ops __read_mostly = {
1560 .kind = DRV_NAME,
1561 .priv_size = sizeof(struct tun_struct),
1562 .setup = tun_setup,
1563 .validate = tun_validate,
1564 };
1565
1566 static void tun_sock_write_space(struct sock *sk)
1567 {
1568 struct tun_file *tfile;
1569 wait_queue_head_t *wqueue;
1570
1571 if (!sock_writeable(sk))
1572 return;
1573
1574 if (!test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags))
1575 return;
1576
1577 wqueue = sk_sleep(sk);
1578 if (wqueue && waitqueue_active(wqueue))
1579 wake_up_interruptible_sync_poll(wqueue, POLLOUT |
1580 POLLWRNORM | POLLWRBAND);
1581
1582 tfile = container_of(sk, struct tun_file, sk);
1583 kill_fasync(&tfile->fasync, SIGIO, POLL_OUT);
1584 }
1585
1586 static int tun_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
1587 {
1588 int ret;
1589 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1590 struct tun_struct *tun = __tun_get(tfile);
1591
1592 if (!tun)
1593 return -EBADFD;
1594
1595 ret = tun_get_user(tun, tfile, m->msg_control, &m->msg_iter,
1596 m->msg_flags & MSG_DONTWAIT);
1597 tun_put(tun);
1598 return ret;
1599 }
1600
1601 static int tun_recvmsg(struct socket *sock, struct msghdr *m, size_t total_len,
1602 int flags)
1603 {
1604 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1605 struct tun_struct *tun = __tun_get(tfile);
1606 int ret;
1607
1608 if (!tun)
1609 return -EBADFD;
1610
1611 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC|MSG_ERRQUEUE)) {
1612 ret = -EINVAL;
1613 goto out;
1614 }
1615 if (flags & MSG_ERRQUEUE) {
1616 ret = sock_recv_errqueue(sock->sk, m, total_len,
1617 SOL_PACKET, TUN_TX_TIMESTAMP);
1618 goto out;
1619 }
1620 ret = tun_do_read(tun, tfile, &m->msg_iter, flags & MSG_DONTWAIT);
1621 if (ret > (ssize_t)total_len) {
1622 m->msg_flags |= MSG_TRUNC;
1623 ret = flags & MSG_TRUNC ? ret : total_len;
1624 }
1625 out:
1626 tun_put(tun);
1627 return ret;
1628 }
1629
1630 static int tun_peek_len(struct socket *sock)
1631 {
1632 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1633 struct tun_struct *tun;
1634 int ret = 0;
1635
1636 tun = __tun_get(tfile);
1637 if (!tun)
1638 return 0;
1639
1640 ret = skb_array_peek_len(&tfile->tx_array);
1641 tun_put(tun);
1642
1643 return ret;
1644 }
1645
1646 /* Ops structure to mimic raw sockets with tun */
1647 static const struct proto_ops tun_socket_ops = {
1648 .peek_len = tun_peek_len,
1649 .sendmsg = tun_sendmsg,
1650 .recvmsg = tun_recvmsg,
1651 };
1652
1653 static struct proto tun_proto = {
1654 .name = "tun",
1655 .owner = THIS_MODULE,
1656 .obj_size = sizeof(struct tun_file),
1657 };
1658
1659 static int tun_flags(struct tun_struct *tun)
1660 {
1661 return tun->flags & (TUN_FEATURES | IFF_PERSIST | IFF_TUN | IFF_TAP);
1662 }
1663
1664 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
1665 char *buf)
1666 {
1667 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1668 return sprintf(buf, "0x%x\n", tun_flags(tun));
1669 }
1670
1671 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
1672 char *buf)
1673 {
1674 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1675 return uid_valid(tun->owner)?
1676 sprintf(buf, "%u\n",
1677 from_kuid_munged(current_user_ns(), tun->owner)):
1678 sprintf(buf, "-1\n");
1679 }
1680
1681 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
1682 char *buf)
1683 {
1684 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1685 return gid_valid(tun->group) ?
1686 sprintf(buf, "%u\n",
1687 from_kgid_munged(current_user_ns(), tun->group)):
1688 sprintf(buf, "-1\n");
1689 }
1690
1691 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
1692 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
1693 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
1694
1695 static struct attribute *tun_dev_attrs[] = {
1696 &dev_attr_tun_flags.attr,
1697 &dev_attr_owner.attr,
1698 &dev_attr_group.attr,
1699 NULL
1700 };
1701
1702 static const struct attribute_group tun_attr_group = {
1703 .attrs = tun_dev_attrs
1704 };
1705
1706 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
1707 {
1708 struct tun_struct *tun;
1709 struct tun_file *tfile = file->private_data;
1710 struct net_device *dev;
1711 int err;
1712
1713 if (tfile->detached)
1714 return -EINVAL;
1715
1716 dev = __dev_get_by_name(net, ifr->ifr_name);
1717 if (dev) {
1718 if (ifr->ifr_flags & IFF_TUN_EXCL)
1719 return -EBUSY;
1720 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
1721 tun = netdev_priv(dev);
1722 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
1723 tun = netdev_priv(dev);
1724 else
1725 return -EINVAL;
1726
1727 if (!!(ifr->ifr_flags & IFF_MULTI_QUEUE) !=
1728 !!(tun->flags & IFF_MULTI_QUEUE))
1729 return -EINVAL;
1730
1731 if (tun_not_capable(tun))
1732 return -EPERM;
1733 err = security_tun_dev_open(tun->security);
1734 if (err < 0)
1735 return err;
1736
1737 err = tun_attach(tun, file, ifr->ifr_flags & IFF_NOFILTER);
1738 if (err < 0)
1739 return err;
1740
1741 if (tun->flags & IFF_MULTI_QUEUE &&
1742 (tun->numqueues + tun->numdisabled > 1)) {
1743 /* One or more queue has already been attached, no need
1744 * to initialize the device again.
1745 */
1746 return 0;
1747 }
1748 }
1749 else {
1750 char *name;
1751 unsigned long flags = 0;
1752 int queues = ifr->ifr_flags & IFF_MULTI_QUEUE ?
1753 MAX_TAP_QUEUES : 1;
1754
1755 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1756 return -EPERM;
1757 err = security_tun_dev_create();
1758 if (err < 0)
1759 return err;
1760
1761 /* Set dev type */
1762 if (ifr->ifr_flags & IFF_TUN) {
1763 /* TUN device */
1764 flags |= IFF_TUN;
1765 name = "tun%d";
1766 } else if (ifr->ifr_flags & IFF_TAP) {
1767 /* TAP device */
1768 flags |= IFF_TAP;
1769 name = "tap%d";
1770 } else
1771 return -EINVAL;
1772
1773 if (*ifr->ifr_name)
1774 name = ifr->ifr_name;
1775
1776 dev = alloc_netdev_mqs(sizeof(struct tun_struct), name,
1777 NET_NAME_UNKNOWN, tun_setup, queues,
1778 queues);
1779
1780 if (!dev)
1781 return -ENOMEM;
1782
1783 dev_net_set(dev, net);
1784 dev->rtnl_link_ops = &tun_link_ops;
1785 dev->ifindex = tfile->ifindex;
1786 dev->sysfs_groups[0] = &tun_attr_group;
1787
1788 tun = netdev_priv(dev);
1789 tun->dev = dev;
1790 tun->flags = flags;
1791 tun->txflt.count = 0;
1792 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
1793
1794 tun->align = NET_SKB_PAD;
1795 tun->filter_attached = false;
1796 tun->sndbuf = tfile->socket.sk->sk_sndbuf;
1797
1798 tun->pcpu_stats = netdev_alloc_pcpu_stats(struct tun_pcpu_stats);
1799 if (!tun->pcpu_stats) {
1800 err = -ENOMEM;
1801 goto err_free_dev;
1802 }
1803
1804 spin_lock_init(&tun->lock);
1805
1806 err = security_tun_dev_alloc_security(&tun->security);
1807 if (err < 0)
1808 goto err_free_stat;
1809
1810 tun_net_init(dev);
1811 tun_flow_init(tun);
1812
1813 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
1814 TUN_USER_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
1815 NETIF_F_HW_VLAN_STAG_TX;
1816 dev->features = dev->hw_features | NETIF_F_LLTX;
1817 dev->vlan_features = dev->features &
1818 ~(NETIF_F_HW_VLAN_CTAG_TX |
1819 NETIF_F_HW_VLAN_STAG_TX);
1820
1821 INIT_LIST_HEAD(&tun->disabled);
1822 err = tun_attach(tun, file, false);
1823 if (err < 0)
1824 goto err_free_flow;
1825
1826 err = register_netdevice(tun->dev);
1827 if (err < 0)
1828 goto err_detach;
1829 }
1830
1831 netif_carrier_on(tun->dev);
1832
1833 tun_debug(KERN_INFO, tun, "tun_set_iff\n");
1834
1835 tun->flags = (tun->flags & ~TUN_FEATURES) |
1836 (ifr->ifr_flags & TUN_FEATURES);
1837
1838 /* Make sure persistent devices do not get stuck in
1839 * xoff state.
1840 */
1841 if (netif_running(tun->dev))
1842 netif_tx_wake_all_queues(tun->dev);
1843
1844 strcpy(ifr->ifr_name, tun->dev->name);
1845 return 0;
1846
1847 err_detach:
1848 tun_detach_all(dev);
1849 err_free_flow:
1850 tun_flow_uninit(tun);
1851 security_tun_dev_free_security(tun->security);
1852 err_free_stat:
1853 free_percpu(tun->pcpu_stats);
1854 err_free_dev:
1855 free_netdev(dev);
1856 return err;
1857 }
1858
1859 static void tun_get_iff(struct net *net, struct tun_struct *tun,
1860 struct ifreq *ifr)
1861 {
1862 tun_debug(KERN_INFO, tun, "tun_get_iff\n");
1863
1864 strcpy(ifr->ifr_name, tun->dev->name);
1865
1866 ifr->ifr_flags = tun_flags(tun);
1867
1868 }
1869
1870 /* This is like a cut-down ethtool ops, except done via tun fd so no
1871 * privs required. */
1872 static int set_offload(struct tun_struct *tun, unsigned long arg)
1873 {
1874 netdev_features_t features = 0;
1875
1876 if (arg & TUN_F_CSUM) {
1877 features |= NETIF_F_HW_CSUM;
1878 arg &= ~TUN_F_CSUM;
1879
1880 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1881 if (arg & TUN_F_TSO_ECN) {
1882 features |= NETIF_F_TSO_ECN;
1883 arg &= ~TUN_F_TSO_ECN;
1884 }
1885 if (arg & TUN_F_TSO4)
1886 features |= NETIF_F_TSO;
1887 if (arg & TUN_F_TSO6)
1888 features |= NETIF_F_TSO6;
1889 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1890 }
1891
1892 if (arg & TUN_F_UFO) {
1893 features |= NETIF_F_UFO;
1894 arg &= ~TUN_F_UFO;
1895 }
1896 }
1897
1898 /* This gives the user a way to test for new features in future by
1899 * trying to set them. */
1900 if (arg)
1901 return -EINVAL;
1902
1903 tun->set_features = features;
1904 netdev_update_features(tun->dev);
1905
1906 return 0;
1907 }
1908
1909 static void tun_detach_filter(struct tun_struct *tun, int n)
1910 {
1911 int i;
1912 struct tun_file *tfile;
1913
1914 for (i = 0; i < n; i++) {
1915 tfile = rtnl_dereference(tun->tfiles[i]);
1916 lock_sock(tfile->socket.sk);
1917 sk_detach_filter(tfile->socket.sk);
1918 release_sock(tfile->socket.sk);
1919 }
1920
1921 tun->filter_attached = false;
1922 }
1923
1924 static int tun_attach_filter(struct tun_struct *tun)
1925 {
1926 int i, ret = 0;
1927 struct tun_file *tfile;
1928
1929 for (i = 0; i < tun->numqueues; i++) {
1930 tfile = rtnl_dereference(tun->tfiles[i]);
1931 lock_sock(tfile->socket.sk);
1932 ret = sk_attach_filter(&tun->fprog, tfile->socket.sk);
1933 release_sock(tfile->socket.sk);
1934 if (ret) {
1935 tun_detach_filter(tun, i);
1936 return ret;
1937 }
1938 }
1939
1940 tun->filter_attached = true;
1941 return ret;
1942 }
1943
1944 static void tun_set_sndbuf(struct tun_struct *tun)
1945 {
1946 struct tun_file *tfile;
1947 int i;
1948
1949 for (i = 0; i < tun->numqueues; i++) {
1950 tfile = rtnl_dereference(tun->tfiles[i]);
1951 tfile->socket.sk->sk_sndbuf = tun->sndbuf;
1952 }
1953 }
1954
1955 static int tun_set_queue(struct file *file, struct ifreq *ifr)
1956 {
1957 struct tun_file *tfile = file->private_data;
1958 struct tun_struct *tun;
1959 int ret = 0;
1960
1961 rtnl_lock();
1962
1963 if (ifr->ifr_flags & IFF_ATTACH_QUEUE) {
1964 tun = tfile->detached;
1965 if (!tun) {
1966 ret = -EINVAL;
1967 goto unlock;
1968 }
1969 ret = security_tun_dev_attach_queue(tun->security);
1970 if (ret < 0)
1971 goto unlock;
1972 ret = tun_attach(tun, file, false);
1973 } else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
1974 tun = rtnl_dereference(tfile->tun);
1975 if (!tun || !(tun->flags & IFF_MULTI_QUEUE) || tfile->detached)
1976 ret = -EINVAL;
1977 else
1978 __tun_detach(tfile, false);
1979 } else
1980 ret = -EINVAL;
1981
1982 unlock:
1983 rtnl_unlock();
1984 return ret;
1985 }
1986
1987 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
1988 unsigned long arg, int ifreq_len)
1989 {
1990 struct tun_file *tfile = file->private_data;
1991 struct tun_struct *tun;
1992 void __user* argp = (void __user*)arg;
1993 struct ifreq ifr;
1994 kuid_t owner;
1995 kgid_t group;
1996 int sndbuf;
1997 int vnet_hdr_sz;
1998 unsigned int ifindex;
1999 int le;
2000 int ret;
2001
2002 if (cmd == TUNSETIFF || cmd == TUNSETQUEUE || _IOC_TYPE(cmd) == 0x89) {
2003 if (copy_from_user(&ifr, argp, ifreq_len))
2004 return -EFAULT;
2005 } else {
2006 memset(&ifr, 0, sizeof(ifr));
2007 }
2008 if (cmd == TUNGETFEATURES) {
2009 /* Currently this just means: "what IFF flags are valid?".
2010 * This is needed because we never checked for invalid flags on
2011 * TUNSETIFF.
2012 */
2013 return put_user(IFF_TUN | IFF_TAP | TUN_FEATURES,
2014 (unsigned int __user*)argp);
2015 } else if (cmd == TUNSETQUEUE)
2016 return tun_set_queue(file, &ifr);
2017
2018 ret = 0;
2019 rtnl_lock();
2020
2021 tun = __tun_get(tfile);
2022 if (cmd == TUNSETIFF && !tun) {
2023 ifr.ifr_name[IFNAMSIZ-1] = '\0';
2024
2025 ret = tun_set_iff(sock_net(&tfile->sk), file, &ifr);
2026
2027 if (ret)
2028 goto unlock;
2029
2030 if (copy_to_user(argp, &ifr, ifreq_len))
2031 ret = -EFAULT;
2032 goto unlock;
2033 }
2034 if (cmd == TUNSETIFINDEX) {
2035 ret = -EPERM;
2036 if (tun)
2037 goto unlock;
2038
2039 ret = -EFAULT;
2040 if (copy_from_user(&ifindex, argp, sizeof(ifindex)))
2041 goto unlock;
2042
2043 ret = 0;
2044 tfile->ifindex = ifindex;
2045 goto unlock;
2046 }
2047
2048 ret = -EBADFD;
2049 if (!tun)
2050 goto unlock;
2051
2052 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %u\n", cmd);
2053
2054 ret = 0;
2055 switch (cmd) {
2056 case TUNGETIFF:
2057 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
2058
2059 if (tfile->detached)
2060 ifr.ifr_flags |= IFF_DETACH_QUEUE;
2061 if (!tfile->socket.sk->sk_filter)
2062 ifr.ifr_flags |= IFF_NOFILTER;
2063
2064 if (copy_to_user(argp, &ifr, ifreq_len))
2065 ret = -EFAULT;
2066 break;
2067
2068 case TUNSETNOCSUM:
2069 /* Disable/Enable checksum */
2070
2071 /* [unimplemented] */
2072 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n",
2073 arg ? "disabled" : "enabled");
2074 break;
2075
2076 case TUNSETPERSIST:
2077 /* Disable/Enable persist mode. Keep an extra reference to the
2078 * module to prevent the module being unprobed.
2079 */
2080 if (arg && !(tun->flags & IFF_PERSIST)) {
2081 tun->flags |= IFF_PERSIST;
2082 __module_get(THIS_MODULE);
2083 }
2084 if (!arg && (tun->flags & IFF_PERSIST)) {
2085 tun->flags &= ~IFF_PERSIST;
2086 module_put(THIS_MODULE);
2087 }
2088
2089 tun_debug(KERN_INFO, tun, "persist %s\n",
2090 arg ? "enabled" : "disabled");
2091 break;
2092
2093 case TUNSETOWNER:
2094 /* Set owner of the device */
2095 owner = make_kuid(current_user_ns(), arg);
2096 if (!uid_valid(owner)) {
2097 ret = -EINVAL;
2098 break;
2099 }
2100 tun->owner = owner;
2101 tun_debug(KERN_INFO, tun, "owner set to %u\n",
2102 from_kuid(&init_user_ns, tun->owner));
2103 break;
2104
2105 case TUNSETGROUP:
2106 /* Set group of the device */
2107 group = make_kgid(current_user_ns(), arg);
2108 if (!gid_valid(group)) {
2109 ret = -EINVAL;
2110 break;
2111 }
2112 tun->group = group;
2113 tun_debug(KERN_INFO, tun, "group set to %u\n",
2114 from_kgid(&init_user_ns, tun->group));
2115 break;
2116
2117 case TUNSETLINK:
2118 /* Only allow setting the type when the interface is down */
2119 if (tun->dev->flags & IFF_UP) {
2120 tun_debug(KERN_INFO, tun,
2121 "Linktype set failed because interface is up\n");
2122 ret = -EBUSY;
2123 } else {
2124 tun->dev->type = (int) arg;
2125 tun_debug(KERN_INFO, tun, "linktype set to %d\n",
2126 tun->dev->type);
2127 ret = 0;
2128 }
2129 break;
2130
2131 #ifdef TUN_DEBUG
2132 case TUNSETDEBUG:
2133 tun->debug = arg;
2134 break;
2135 #endif
2136 case TUNSETOFFLOAD:
2137 ret = set_offload(tun, arg);
2138 break;
2139
2140 case TUNSETTXFILTER:
2141 /* Can be set only for TAPs */
2142 ret = -EINVAL;
2143 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2144 break;
2145 ret = update_filter(&tun->txflt, (void __user *)arg);
2146 break;
2147
2148 case SIOCGIFHWADDR:
2149 /* Get hw address */
2150 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
2151 ifr.ifr_hwaddr.sa_family = tun->dev->type;
2152 if (copy_to_user(argp, &ifr, ifreq_len))
2153 ret = -EFAULT;
2154 break;
2155
2156 case SIOCSIFHWADDR:
2157 /* Set hw address */
2158 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
2159 ifr.ifr_hwaddr.sa_data);
2160
2161 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
2162 break;
2163
2164 case TUNGETSNDBUF:
2165 sndbuf = tfile->socket.sk->sk_sndbuf;
2166 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
2167 ret = -EFAULT;
2168 break;
2169
2170 case TUNSETSNDBUF:
2171 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
2172 ret = -EFAULT;
2173 break;
2174 }
2175
2176 tun->sndbuf = sndbuf;
2177 tun_set_sndbuf(tun);
2178 break;
2179
2180 case TUNGETVNETHDRSZ:
2181 vnet_hdr_sz = tun->vnet_hdr_sz;
2182 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
2183 ret = -EFAULT;
2184 break;
2185
2186 case TUNSETVNETHDRSZ:
2187 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
2188 ret = -EFAULT;
2189 break;
2190 }
2191 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
2192 ret = -EINVAL;
2193 break;
2194 }
2195
2196 tun->vnet_hdr_sz = vnet_hdr_sz;
2197 break;
2198
2199 case TUNGETVNETLE:
2200 le = !!(tun->flags & TUN_VNET_LE);
2201 if (put_user(le, (int __user *)argp))
2202 ret = -EFAULT;
2203 break;
2204
2205 case TUNSETVNETLE:
2206 if (get_user(le, (int __user *)argp)) {
2207 ret = -EFAULT;
2208 break;
2209 }
2210 if (le)
2211 tun->flags |= TUN_VNET_LE;
2212 else
2213 tun->flags &= ~TUN_VNET_LE;
2214 break;
2215
2216 case TUNGETVNETBE:
2217 ret = tun_get_vnet_be(tun, argp);
2218 break;
2219
2220 case TUNSETVNETBE:
2221 ret = tun_set_vnet_be(tun, argp);
2222 break;
2223
2224 case TUNATTACHFILTER:
2225 /* Can be set only for TAPs */
2226 ret = -EINVAL;
2227 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2228 break;
2229 ret = -EFAULT;
2230 if (copy_from_user(&tun->fprog, argp, sizeof(tun->fprog)))
2231 break;
2232
2233 ret = tun_attach_filter(tun);
2234 break;
2235
2236 case TUNDETACHFILTER:
2237 /* Can be set only for TAPs */
2238 ret = -EINVAL;
2239 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2240 break;
2241 ret = 0;
2242 tun_detach_filter(tun, tun->numqueues);
2243 break;
2244
2245 case TUNGETFILTER:
2246 ret = -EINVAL;
2247 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2248 break;
2249 ret = -EFAULT;
2250 if (copy_to_user(argp, &tun->fprog, sizeof(tun->fprog)))
2251 break;
2252 ret = 0;
2253 break;
2254
2255 default:
2256 ret = -EINVAL;
2257 break;
2258 }
2259
2260 unlock:
2261 rtnl_unlock();
2262 if (tun)
2263 tun_put(tun);
2264 return ret;
2265 }
2266
2267 static long tun_chr_ioctl(struct file *file,
2268 unsigned int cmd, unsigned long arg)
2269 {
2270 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
2271 }
2272
2273 #ifdef CONFIG_COMPAT
2274 static long tun_chr_compat_ioctl(struct file *file,
2275 unsigned int cmd, unsigned long arg)
2276 {
2277 switch (cmd) {
2278 case TUNSETIFF:
2279 case TUNGETIFF:
2280 case TUNSETTXFILTER:
2281 case TUNGETSNDBUF:
2282 case TUNSETSNDBUF:
2283 case SIOCGIFHWADDR:
2284 case SIOCSIFHWADDR:
2285 arg = (unsigned long)compat_ptr(arg);
2286 break;
2287 default:
2288 arg = (compat_ulong_t)arg;
2289 break;
2290 }
2291
2292 /*
2293 * compat_ifreq is shorter than ifreq, so we must not access beyond
2294 * the end of that structure. All fields that are used in this
2295 * driver are compatible though, we don't need to convert the
2296 * contents.
2297 */
2298 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
2299 }
2300 #endif /* CONFIG_COMPAT */
2301
2302 static int tun_chr_fasync(int fd, struct file *file, int on)
2303 {
2304 struct tun_file *tfile = file->private_data;
2305 int ret;
2306
2307 if ((ret = fasync_helper(fd, file, on, &tfile->fasync)) < 0)
2308 goto out;
2309
2310 if (on) {
2311 __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
2312 tfile->flags |= TUN_FASYNC;
2313 } else
2314 tfile->flags &= ~TUN_FASYNC;
2315 ret = 0;
2316 out:
2317 return ret;
2318 }
2319
2320 static int tun_chr_open(struct inode *inode, struct file * file)
2321 {
2322 struct net *net = current->nsproxy->net_ns;
2323 struct tun_file *tfile;
2324
2325 DBG1(KERN_INFO, "tunX: tun_chr_open\n");
2326
2327 tfile = (struct tun_file *)sk_alloc(net, AF_UNSPEC, GFP_KERNEL,
2328 &tun_proto, 0);
2329 if (!tfile)
2330 return -ENOMEM;
2331 RCU_INIT_POINTER(tfile->tun, NULL);
2332 tfile->flags = 0;
2333 tfile->ifindex = 0;
2334
2335 init_waitqueue_head(&tfile->wq.wait);
2336 RCU_INIT_POINTER(tfile->socket.wq, &tfile->wq);
2337
2338 tfile->socket.file = file;
2339 tfile->socket.ops = &tun_socket_ops;
2340
2341 sock_init_data(&tfile->socket, &tfile->sk);
2342
2343 tfile->sk.sk_write_space = tun_sock_write_space;
2344 tfile->sk.sk_sndbuf = INT_MAX;
2345
2346 file->private_data = tfile;
2347 INIT_LIST_HEAD(&tfile->next);
2348
2349 sock_set_flag(&tfile->sk, SOCK_ZEROCOPY);
2350
2351 return 0;
2352 }
2353
2354 static int tun_chr_close(struct inode *inode, struct file *file)
2355 {
2356 struct tun_file *tfile = file->private_data;
2357
2358 tun_detach(tfile, true);
2359
2360 return 0;
2361 }
2362
2363 #ifdef CONFIG_PROC_FS
2364 static void tun_chr_show_fdinfo(struct seq_file *m, struct file *f)
2365 {
2366 struct tun_struct *tun;
2367 struct ifreq ifr;
2368
2369 memset(&ifr, 0, sizeof(ifr));
2370
2371 rtnl_lock();
2372 tun = tun_get(f);
2373 if (tun)
2374 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
2375 rtnl_unlock();
2376
2377 if (tun)
2378 tun_put(tun);
2379
2380 seq_printf(m, "iff:\t%s\n", ifr.ifr_name);
2381 }
2382 #endif
2383
2384 static const struct file_operations tun_fops = {
2385 .owner = THIS_MODULE,
2386 .llseek = no_llseek,
2387 .read_iter = tun_chr_read_iter,
2388 .write_iter = tun_chr_write_iter,
2389 .poll = tun_chr_poll,
2390 .unlocked_ioctl = tun_chr_ioctl,
2391 #ifdef CONFIG_COMPAT
2392 .compat_ioctl = tun_chr_compat_ioctl,
2393 #endif
2394 .open = tun_chr_open,
2395 .release = tun_chr_close,
2396 .fasync = tun_chr_fasync,
2397 #ifdef CONFIG_PROC_FS
2398 .show_fdinfo = tun_chr_show_fdinfo,
2399 #endif
2400 };
2401
2402 static struct miscdevice tun_miscdev = {
2403 .minor = TUN_MINOR,
2404 .name = "tun",
2405 .nodename = "net/tun",
2406 .fops = &tun_fops,
2407 };
2408
2409 /* ethtool interface */
2410
2411 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
2412 {
2413 cmd->supported = 0;
2414 cmd->advertising = 0;
2415 ethtool_cmd_speed_set(cmd, SPEED_10);
2416 cmd->duplex = DUPLEX_FULL;
2417 cmd->port = PORT_TP;
2418 cmd->phy_address = 0;
2419 cmd->transceiver = XCVR_INTERNAL;
2420 cmd->autoneg = AUTONEG_DISABLE;
2421 cmd->maxtxpkt = 0;
2422 cmd->maxrxpkt = 0;
2423 return 0;
2424 }
2425
2426 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
2427 {
2428 struct tun_struct *tun = netdev_priv(dev);
2429
2430 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
2431 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
2432
2433 switch (tun->flags & TUN_TYPE_MASK) {
2434 case IFF_TUN:
2435 strlcpy(info->bus_info, "tun", sizeof(info->bus_info));
2436 break;
2437 case IFF_TAP:
2438 strlcpy(info->bus_info, "tap", sizeof(info->bus_info));
2439 break;
2440 }
2441 }
2442
2443 static u32 tun_get_msglevel(struct net_device *dev)
2444 {
2445 #ifdef TUN_DEBUG
2446 struct tun_struct *tun = netdev_priv(dev);
2447 return tun->debug;
2448 #else
2449 return -EOPNOTSUPP;
2450 #endif
2451 }
2452
2453 static void tun_set_msglevel(struct net_device *dev, u32 value)
2454 {
2455 #ifdef TUN_DEBUG
2456 struct tun_struct *tun = netdev_priv(dev);
2457 tun->debug = value;
2458 #endif
2459 }
2460
2461 static const struct ethtool_ops tun_ethtool_ops = {
2462 .get_settings = tun_get_settings,
2463 .get_drvinfo = tun_get_drvinfo,
2464 .get_msglevel = tun_get_msglevel,
2465 .set_msglevel = tun_set_msglevel,
2466 .get_link = ethtool_op_get_link,
2467 .get_ts_info = ethtool_op_get_ts_info,
2468 };
2469
2470 static int tun_queue_resize(struct tun_struct *tun)
2471 {
2472 struct net_device *dev = tun->dev;
2473 struct tun_file *tfile;
2474 struct skb_array **arrays;
2475 int n = tun->numqueues + tun->numdisabled;
2476 int ret, i;
2477
2478 arrays = kmalloc(sizeof *arrays * n, GFP_KERNEL);
2479 if (!arrays)
2480 return -ENOMEM;
2481
2482 for (i = 0; i < tun->numqueues; i++) {
2483 tfile = rtnl_dereference(tun->tfiles[i]);
2484 arrays[i] = &tfile->tx_array;
2485 }
2486 list_for_each_entry(tfile, &tun->disabled, next)
2487 arrays[i++] = &tfile->tx_array;
2488
2489 ret = skb_array_resize_multiple(arrays, n,
2490 dev->tx_queue_len, GFP_KERNEL);
2491
2492 kfree(arrays);
2493 return ret;
2494 }
2495
2496 static int tun_device_event(struct notifier_block *unused,
2497 unsigned long event, void *ptr)
2498 {
2499 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
2500 struct tun_struct *tun = netdev_priv(dev);
2501
2502 if (dev->rtnl_link_ops != &tun_link_ops)
2503 return NOTIFY_DONE;
2504
2505 switch (event) {
2506 case NETDEV_CHANGE_TX_QUEUE_LEN:
2507 if (tun_queue_resize(tun))
2508 return NOTIFY_BAD;
2509 break;
2510 default:
2511 break;
2512 }
2513
2514 return NOTIFY_DONE;
2515 }
2516
2517 static struct notifier_block tun_notifier_block __read_mostly = {
2518 .notifier_call = tun_device_event,
2519 };
2520
2521 static int __init tun_init(void)
2522 {
2523 int ret = 0;
2524
2525 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
2526 pr_info("%s\n", DRV_COPYRIGHT);
2527
2528 ret = rtnl_link_register(&tun_link_ops);
2529 if (ret) {
2530 pr_err("Can't register link_ops\n");
2531 goto err_linkops;
2532 }
2533
2534 ret = misc_register(&tun_miscdev);
2535 if (ret) {
2536 pr_err("Can't register misc device %d\n", TUN_MINOR);
2537 goto err_misc;
2538 }
2539
2540 register_netdevice_notifier(&tun_notifier_block);
2541 return 0;
2542 err_misc:
2543 rtnl_link_unregister(&tun_link_ops);
2544 err_linkops:
2545 return ret;
2546 }
2547
2548 static void tun_cleanup(void)
2549 {
2550 misc_deregister(&tun_miscdev);
2551 rtnl_link_unregister(&tun_link_ops);
2552 unregister_netdevice_notifier(&tun_notifier_block);
2553 }
2554
2555 /* Get an underlying socket object from tun file. Returns error unless file is
2556 * attached to a device. The returned object works like a packet socket, it
2557 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
2558 * holding a reference to the file for as long as the socket is in use. */
2559 struct socket *tun_get_socket(struct file *file)
2560 {
2561 struct tun_file *tfile;
2562 if (file->f_op != &tun_fops)
2563 return ERR_PTR(-EINVAL);
2564 tfile = file->private_data;
2565 if (!tfile)
2566 return ERR_PTR(-EBADFD);
2567 return &tfile->socket;
2568 }
2569 EXPORT_SYMBOL_GPL(tun_get_socket);
2570
2571 module_init(tun_init);
2572 module_exit(tun_cleanup);
2573 MODULE_DESCRIPTION(DRV_DESCRIPTION);
2574 MODULE_AUTHOR(DRV_COPYRIGHT);
2575 MODULE_LICENSE("GPL");
2576 MODULE_ALIAS_MISCDEV(TUN_MINOR);
2577 MODULE_ALIAS("devname:net/tun");
Linux kernel - Deliverables
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