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irqchip/s3c24xx: Mark init_eint as __maybe_unused
[linux/fpc-iii.git] / drivers / net / tun.c
blobf0db770e8b2f9655be8d3c3000a9395f945284e2
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 #define TUN_VNET_BE 0x40000000
115
116 #define TUN_FEATURES (IFF_NO_PI | IFF_ONE_QUEUE | IFF_VNET_HDR | \
117 IFF_MULTI_QUEUE)
118 #define GOODCOPY_LEN 128
119
120 #define FLT_EXACT_COUNT 8
121 struct tap_filter {
122 unsigned int count; /* Number of addrs. Zero means disabled */
123 u32 mask[2]; /* Mask of the hashed addrs */
124 unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN];
125 };
126
127 /* MAX_TAP_QUEUES 256 is chosen to allow rx/tx queues to be equal
128 * to max number of VCPUs in guest. */
129 #define MAX_TAP_QUEUES 256
130 #define MAX_TAP_FLOWS 4096
131
132 #define TUN_FLOW_EXPIRE (3 * HZ)
133
134 /* A tun_file connects an open character device to a tuntap netdevice. It
135 * also contains all socket related structures (except sock_fprog and tap_filter)
136 * to serve as one transmit queue for tuntap device. The sock_fprog and
137 * tap_filter were kept in tun_struct since they were used for filtering for the
138 * netdevice not for a specific queue (at least I didn't see the requirement for
139 * this).
140 *
141 * RCU usage:
142 * The tun_file and tun_struct are loosely coupled, the pointer from one to the
143 * other can only be read while rcu_read_lock or rtnl_lock is held.
144 */
145 struct tun_file {
146 struct sock sk;
147 struct socket socket;
148 struct socket_wq wq;
149 struct tun_struct __rcu *tun;
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 #ifdef CONFIG_TUN_VNET_CROSS_LE
210 static inline bool tun_legacy_is_little_endian(struct tun_struct *tun)
211 {
212 return tun->flags & TUN_VNET_BE ? false :
213 virtio_legacy_is_little_endian();
214 }
215
216 static long tun_get_vnet_be(struct tun_struct *tun, int __user *argp)
217 {
218 int be = !!(tun->flags & TUN_VNET_BE);
219
220 if (put_user(be, argp))
221 return -EFAULT;
222
223 return 0;
224 }
225
226 static long tun_set_vnet_be(struct tun_struct *tun, int __user *argp)
227 {
228 int be;
229
230 if (get_user(be, argp))
231 return -EFAULT;
232
233 if (be)
234 tun->flags |= TUN_VNET_BE;
235 else
236 tun->flags &= ~TUN_VNET_BE;
237
238 return 0;
239 }
240 #else
241 static inline bool tun_legacy_is_little_endian(struct tun_struct *tun)
242 {
243 return virtio_legacy_is_little_endian();
244 }
245
246 static long tun_get_vnet_be(struct tun_struct *tun, int __user *argp)
247 {
248 return -EINVAL;
249 }
250
251 static long tun_set_vnet_be(struct tun_struct *tun, int __user *argp)
252 {
253 return -EINVAL;
254 }
255 #endif /* CONFIG_TUN_VNET_CROSS_LE */
256
257 static inline bool tun_is_little_endian(struct tun_struct *tun)
258 {
259 return tun->flags & TUN_VNET_LE ||
260 tun_legacy_is_little_endian(tun);
261 }
262
263 static inline u16 tun16_to_cpu(struct tun_struct *tun, __virtio16 val)
264 {
265 return __virtio16_to_cpu(tun_is_little_endian(tun), val);
266 }
267
268 static inline __virtio16 cpu_to_tun16(struct tun_struct *tun, u16 val)
269 {
270 return __cpu_to_virtio16(tun_is_little_endian(tun), val);
271 }
272
273 static inline u32 tun_hashfn(u32 rxhash)
274 {
275 return rxhash & 0x3ff;
276 }
277
278 static struct tun_flow_entry *tun_flow_find(struct hlist_head *head, u32 rxhash)
279 {
280 struct tun_flow_entry *e;
281
282 hlist_for_each_entry_rcu(e, head, hash_link) {
283 if (e->rxhash == rxhash)
284 return e;
285 }
286 return NULL;
287 }
288
289 static struct tun_flow_entry *tun_flow_create(struct tun_struct *tun,
290 struct hlist_head *head,
291 u32 rxhash, u16 queue_index)
292 {
293 struct tun_flow_entry *e = kmalloc(sizeof(*e), GFP_ATOMIC);
294
295 if (e) {
296 tun_debug(KERN_INFO, tun, "create flow: hash %u index %u\n",
297 rxhash, queue_index);
298 e->updated = jiffies;
299 e->rxhash = rxhash;
300 e->rps_rxhash = 0;
301 e->queue_index = queue_index;
302 e->tun = tun;
303 hlist_add_head_rcu(&e->hash_link, head);
304 ++tun->flow_count;
305 }
306 return e;
307 }
308
309 static void tun_flow_delete(struct tun_struct *tun, struct tun_flow_entry *e)
310 {
311 tun_debug(KERN_INFO, tun, "delete flow: hash %u index %u\n",
312 e->rxhash, e->queue_index);
313 hlist_del_rcu(&e->hash_link);
314 kfree_rcu(e, rcu);
315 --tun->flow_count;
316 }
317
318 static void tun_flow_flush(struct tun_struct *tun)
319 {
320 int i;
321
322 spin_lock_bh(&tun->lock);
323 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
324 struct tun_flow_entry *e;
325 struct hlist_node *n;
326
327 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link)
328 tun_flow_delete(tun, e);
329 }
330 spin_unlock_bh(&tun->lock);
331 }
332
333 static void tun_flow_delete_by_queue(struct tun_struct *tun, u16 queue_index)
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 if (e->queue_index == queue_index)
344 tun_flow_delete(tun, e);
345 }
346 }
347 spin_unlock_bh(&tun->lock);
348 }
349
350 static void tun_flow_cleanup(unsigned long data)
351 {
352 struct tun_struct *tun = (struct tun_struct *)data;
353 unsigned long delay = tun->ageing_time;
354 unsigned long next_timer = jiffies + delay;
355 unsigned long count = 0;
356 int i;
357
358 tun_debug(KERN_INFO, tun, "tun_flow_cleanup\n");
359
360 spin_lock_bh(&tun->lock);
361 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
362 struct tun_flow_entry *e;
363 struct hlist_node *n;
364
365 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
366 unsigned long this_timer;
367 count++;
368 this_timer = e->updated + delay;
369 if (time_before_eq(this_timer, jiffies))
370 tun_flow_delete(tun, e);
371 else if (time_before(this_timer, next_timer))
372 next_timer = this_timer;
373 }
374 }
375
376 if (count)
377 mod_timer(&tun->flow_gc_timer, round_jiffies_up(next_timer));
378 spin_unlock_bh(&tun->lock);
379 }
380
381 static void tun_flow_update(struct tun_struct *tun, u32 rxhash,
382 struct tun_file *tfile)
383 {
384 struct hlist_head *head;
385 struct tun_flow_entry *e;
386 unsigned long delay = tun->ageing_time;
387 u16 queue_index = tfile->queue_index;
388
389 if (!rxhash)
390 return;
391 else
392 head = &tun->flows[tun_hashfn(rxhash)];
393
394 rcu_read_lock();
395
396 /* We may get a very small possibility of OOO during switching, not
397 * worth to optimize.*/
398 if (tun->numqueues == 1 || tfile->detached)
399 goto unlock;
400
401 e = tun_flow_find(head, rxhash);
402 if (likely(e)) {
403 /* TODO: keep queueing to old queue until it's empty? */
404 e->queue_index = queue_index;
405 e->updated = jiffies;
406 sock_rps_record_flow_hash(e->rps_rxhash);
407 } else {
408 spin_lock_bh(&tun->lock);
409 if (!tun_flow_find(head, rxhash) &&
410 tun->flow_count < MAX_TAP_FLOWS)
411 tun_flow_create(tun, head, rxhash, queue_index);
412
413 if (!timer_pending(&tun->flow_gc_timer))
414 mod_timer(&tun->flow_gc_timer,
415 round_jiffies_up(jiffies + delay));
416 spin_unlock_bh(&tun->lock);
417 }
418
419 unlock:
420 rcu_read_unlock();
421 }
422
423 /**
424 * Save the hash received in the stack receive path and update the
425 * flow_hash table accordingly.
426 */
427 static inline void tun_flow_save_rps_rxhash(struct tun_flow_entry *e, u32 hash)
428 {
429 if (unlikely(e->rps_rxhash != hash))
430 e->rps_rxhash = hash;
431 }
432
433 /* We try to identify a flow through its rxhash first. The reason that
434 * we do not check rxq no. is because some cards(e.g 82599), chooses
435 * the rxq based on the txq where the last packet of the flow comes. As
436 * the userspace application move between processors, we may get a
437 * different rxq no. here. If we could not get rxhash, then we would
438 * hope the rxq no. may help here.
439 */
440 static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb,
441 void *accel_priv, select_queue_fallback_t fallback)
442 {
443 struct tun_struct *tun = netdev_priv(dev);
444 struct tun_flow_entry *e;
445 u32 txq = 0;
446 u32 numqueues = 0;
447
448 rcu_read_lock();
449 numqueues = ACCESS_ONCE(tun->numqueues);
450
451 txq = skb_get_hash(skb);
452 if (txq) {
453 e = tun_flow_find(&tun->flows[tun_hashfn(txq)], txq);
454 if (e) {
455 tun_flow_save_rps_rxhash(e, txq);
456 txq = e->queue_index;
457 } else
458 /* use multiply and shift instead of expensive divide */
459 txq = ((u64)txq * numqueues) >> 32;
460 } else if (likely(skb_rx_queue_recorded(skb))) {
461 txq = skb_get_rx_queue(skb);
462 while (unlikely(txq >= numqueues))
463 txq -= numqueues;
464 }
465
466 rcu_read_unlock();
467 return txq;
468 }
469
470 static inline bool tun_not_capable(struct tun_struct *tun)
471 {
472 const struct cred *cred = current_cred();
473 struct net *net = dev_net(tun->dev);
474
475 return ((uid_valid(tun->owner) && !uid_eq(cred->euid, tun->owner)) ||
476 (gid_valid(tun->group) && !in_egroup_p(tun->group))) &&
477 !ns_capable(net->user_ns, CAP_NET_ADMIN);
478 }
479
480 static void tun_set_real_num_queues(struct tun_struct *tun)
481 {
482 netif_set_real_num_tx_queues(tun->dev, tun->numqueues);
483 netif_set_real_num_rx_queues(tun->dev, tun->numqueues);
484 }
485
486 static void tun_disable_queue(struct tun_struct *tun, struct tun_file *tfile)
487 {
488 tfile->detached = tun;
489 list_add_tail(&tfile->next, &tun->disabled);
490 ++tun->numdisabled;
491 }
492
493 static struct tun_struct *tun_enable_queue(struct tun_file *tfile)
494 {
495 struct tun_struct *tun = tfile->detached;
496
497 tfile->detached = NULL;
498 list_del_init(&tfile->next);
499 --tun->numdisabled;
500 return tun;
501 }
502
503 static void tun_queue_purge(struct tun_file *tfile)
504 {
505 skb_queue_purge(&tfile->sk.sk_receive_queue);
506 skb_queue_purge(&tfile->sk.sk_error_queue);
507 }
508
509 static void __tun_detach(struct tun_file *tfile, bool clean)
510 {
511 struct tun_file *ntfile;
512 struct tun_struct *tun;
513
514 tun = rtnl_dereference(tfile->tun);
515
516 if (tun && !tfile->detached) {
517 u16 index = tfile->queue_index;
518 BUG_ON(index >= tun->numqueues);
519
520 rcu_assign_pointer(tun->tfiles[index],
521 tun->tfiles[tun->numqueues - 1]);
522 ntfile = rtnl_dereference(tun->tfiles[index]);
523 ntfile->queue_index = index;
524
525 --tun->numqueues;
526 if (clean) {
527 RCU_INIT_POINTER(tfile->tun, NULL);
528 sock_put(&tfile->sk);
529 } else
530 tun_disable_queue(tun, tfile);
531
532 synchronize_net();
533 tun_flow_delete_by_queue(tun, tun->numqueues + 1);
534 /* Drop read queue */
535 tun_queue_purge(tfile);
536 tun_set_real_num_queues(tun);
537 } else if (tfile->detached && clean) {
538 tun = tun_enable_queue(tfile);
539 sock_put(&tfile->sk);
540 }
541
542 if (clean) {
543 if (tun && tun->numqueues == 0 && tun->numdisabled == 0) {
544 netif_carrier_off(tun->dev);
545
546 if (!(tun->flags & IFF_PERSIST) &&
547 tun->dev->reg_state == NETREG_REGISTERED)
548 unregister_netdevice(tun->dev);
549 }
550 sock_put(&tfile->sk);
551 }
552 }
553
554 static void tun_detach(struct tun_file *tfile, bool clean)
555 {
556 rtnl_lock();
557 __tun_detach(tfile, clean);
558 rtnl_unlock();
559 }
560
561 static void tun_detach_all(struct net_device *dev)
562 {
563 struct tun_struct *tun = netdev_priv(dev);
564 struct tun_file *tfile, *tmp;
565 int i, n = tun->numqueues;
566
567 for (i = 0; i < n; i++) {
568 tfile = rtnl_dereference(tun->tfiles[i]);
569 BUG_ON(!tfile);
570 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
571 RCU_INIT_POINTER(tfile->tun, NULL);
572 --tun->numqueues;
573 }
574 list_for_each_entry(tfile, &tun->disabled, next) {
575 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
576 RCU_INIT_POINTER(tfile->tun, NULL);
577 }
578 BUG_ON(tun->numqueues != 0);
579
580 synchronize_net();
581 for (i = 0; i < n; i++) {
582 tfile = rtnl_dereference(tun->tfiles[i]);
583 /* Drop read queue */
584 tun_queue_purge(tfile);
585 sock_put(&tfile->sk);
586 }
587 list_for_each_entry_safe(tfile, tmp, &tun->disabled, next) {
588 tun_enable_queue(tfile);
589 tun_queue_purge(tfile);
590 sock_put(&tfile->sk);
591 }
592 BUG_ON(tun->numdisabled != 0);
593
594 if (tun->flags & IFF_PERSIST)
595 module_put(THIS_MODULE);
596 }
597
598 static int tun_attach(struct tun_struct *tun, struct file *file, bool skip_filter)
599 {
600 struct tun_file *tfile = file->private_data;
601 int err;
602
603 err = security_tun_dev_attach(tfile->socket.sk, tun->security);
604 if (err < 0)
605 goto out;
606
607 err = -EINVAL;
608 if (rtnl_dereference(tfile->tun) && !tfile->detached)
609 goto out;
610
611 err = -EBUSY;
612 if (!(tun->flags & IFF_MULTI_QUEUE) && tun->numqueues == 1)
613 goto out;
614
615 err = -E2BIG;
616 if (!tfile->detached &&
617 tun->numqueues + tun->numdisabled == MAX_TAP_QUEUES)
618 goto out;
619
620 err = 0;
621
622 /* Re-attach the filter to persist device */
623 if (!skip_filter && (tun->filter_attached == true)) {
624 err = sk_attach_filter(&tun->fprog, tfile->socket.sk);
625 if (!err)
626 goto out;
627 }
628 tfile->queue_index = tun->numqueues;
629 rcu_assign_pointer(tfile->tun, tun);
630 rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile);
631 tun->numqueues++;
632
633 if (tfile->detached)
634 tun_enable_queue(tfile);
635 else
636 sock_hold(&tfile->sk);
637
638 tun_set_real_num_queues(tun);
639
640 /* device is allowed to go away first, so no need to hold extra
641 * refcnt.
642 */
643
644 out:
645 return err;
646 }
647
648 static struct tun_struct *__tun_get(struct tun_file *tfile)
649 {
650 struct tun_struct *tun;
651
652 rcu_read_lock();
653 tun = rcu_dereference(tfile->tun);
654 if (tun)
655 dev_hold(tun->dev);
656 rcu_read_unlock();
657
658 return tun;
659 }
660
661 static struct tun_struct *tun_get(struct file *file)
662 {
663 return __tun_get(file->private_data);
664 }
665
666 static void tun_put(struct tun_struct *tun)
667 {
668 dev_put(tun->dev);
669 }
670
671 /* TAP filtering */
672 static void addr_hash_set(u32 *mask, const u8 *addr)
673 {
674 int n = ether_crc(ETH_ALEN, addr) >> 26;
675 mask[n >> 5] |= (1 << (n & 31));
676 }
677
678 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
679 {
680 int n = ether_crc(ETH_ALEN, addr) >> 26;
681 return mask[n >> 5] & (1 << (n & 31));
682 }
683
684 static int update_filter(struct tap_filter *filter, void __user *arg)
685 {
686 struct { u8 u[ETH_ALEN]; } *addr;
687 struct tun_filter uf;
688 int err, alen, n, nexact;
689
690 if (copy_from_user(&uf, arg, sizeof(uf)))
691 return -EFAULT;
692
693 if (!uf.count) {
694 /* Disabled */
695 filter->count = 0;
696 return 0;
697 }
698
699 alen = ETH_ALEN * uf.count;
700 addr = kmalloc(alen, GFP_KERNEL);
701 if (!addr)
702 return -ENOMEM;
703
704 if (copy_from_user(addr, arg + sizeof(uf), alen)) {
705 err = -EFAULT;
706 goto done;
707 }
708
709 /* The filter is updated without holding any locks. Which is
710 * perfectly safe. We disable it first and in the worst
711 * case we'll accept a few undesired packets. */
712 filter->count = 0;
713 wmb();
714
715 /* Use first set of addresses as an exact filter */
716 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
717 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
718
719 nexact = n;
720
721 /* Remaining multicast addresses are hashed,
722 * unicast will leave the filter disabled. */
723 memset(filter->mask, 0, sizeof(filter->mask));
724 for (; n < uf.count; n++) {
725 if (!is_multicast_ether_addr(addr[n].u)) {
726 err = 0; /* no filter */
727 goto done;
728 }
729 addr_hash_set(filter->mask, addr[n].u);
730 }
731
732 /* For ALLMULTI just set the mask to all ones.
733 * This overrides the mask populated above. */
734 if ((uf.flags & TUN_FLT_ALLMULTI))
735 memset(filter->mask, ~0, sizeof(filter->mask));
736
737 /* Now enable the filter */
738 wmb();
739 filter->count = nexact;
740
741 /* Return the number of exact filters */
742 err = nexact;
743
744 done:
745 kfree(addr);
746 return err;
747 }
748
749 /* Returns: 0 - drop, !=0 - accept */
750 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
751 {
752 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
753 * at this point. */
754 struct ethhdr *eh = (struct ethhdr *) skb->data;
755 int i;
756
757 /* Exact match */
758 for (i = 0; i < filter->count; i++)
759 if (ether_addr_equal(eh->h_dest, filter->addr[i]))
760 return 1;
761
762 /* Inexact match (multicast only) */
763 if (is_multicast_ether_addr(eh->h_dest))
764 return addr_hash_test(filter->mask, eh->h_dest);
765
766 return 0;
767 }
768
769 /*
770 * Checks whether the packet is accepted or not.
771 * Returns: 0 - drop, !=0 - accept
772 */
773 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
774 {
775 if (!filter->count)
776 return 1;
777
778 return run_filter(filter, skb);
779 }
780
781 /* Network device part of the driver */
782
783 static const struct ethtool_ops tun_ethtool_ops;
784
785 /* Net device detach from fd. */
786 static void tun_net_uninit(struct net_device *dev)
787 {
788 tun_detach_all(dev);
789 }
790
791 /* Net device open. */
792 static int tun_net_open(struct net_device *dev)
793 {
794 netif_tx_start_all_queues(dev);
795 return 0;
796 }
797
798 /* Net device close. */
799 static int tun_net_close(struct net_device *dev)
800 {
801 netif_tx_stop_all_queues(dev);
802 return 0;
803 }
804
805 /* Net device start xmit */
806 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
807 {
808 struct tun_struct *tun = netdev_priv(dev);
809 int txq = skb->queue_mapping;
810 struct tun_file *tfile;
811 u32 numqueues = 0;
812
813 rcu_read_lock();
814 tfile = rcu_dereference(tun->tfiles[txq]);
815 numqueues = ACCESS_ONCE(tun->numqueues);
816
817 /* Drop packet if interface is not attached */
818 if (txq >= numqueues)
819 goto drop;
820
821 if (numqueues == 1) {
822 /* Select queue was not called for the skbuff, so we extract the
823 * RPS hash and save it into the flow_table here.
824 */
825 __u32 rxhash;
826
827 rxhash = skb_get_hash(skb);
828 if (rxhash) {
829 struct tun_flow_entry *e;
830 e = tun_flow_find(&tun->flows[tun_hashfn(rxhash)],
831 rxhash);
832 if (e)
833 tun_flow_save_rps_rxhash(e, rxhash);
834 }
835 }
836
837 tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len);
838
839 BUG_ON(!tfile);
840
841 /* Drop if the filter does not like it.
842 * This is a noop if the filter is disabled.
843 * Filter can be enabled only for the TAP devices. */
844 if (!check_filter(&tun->txflt, skb))
845 goto drop;
846
847 if (tfile->socket.sk->sk_filter &&
848 sk_filter(tfile->socket.sk, skb))
849 goto drop;
850
851 /* Limit the number of packets queued by dividing txq length with the
852 * number of queues.
853 */
854 if (skb_queue_len(&tfile->socket.sk->sk_receive_queue) * numqueues
855 >= dev->tx_queue_len)
856 goto drop;
857
858 if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
859 goto drop;
860
861 if (skb->sk && sk_fullsock(skb->sk)) {
862 sock_tx_timestamp(skb->sk, &skb_shinfo(skb)->tx_flags);
863 sw_tx_timestamp(skb);
864 }
865
866 /* Orphan the skb - required as we might hang on to it
867 * for indefinite time.
868 */
869 skb_orphan(skb);
870
871 nf_reset(skb);
872
873 /* Enqueue packet */
874 skb_queue_tail(&tfile->socket.sk->sk_receive_queue, skb);
875
876 /* Notify and wake up reader process */
877 if (tfile->flags & TUN_FASYNC)
878 kill_fasync(&tfile->fasync, SIGIO, POLL_IN);
879 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
880
881 rcu_read_unlock();
882 return NETDEV_TX_OK;
883
884 drop:
885 dev->stats.tx_dropped++;
886 skb_tx_error(skb);
887 kfree_skb(skb);
888 rcu_read_unlock();
889 return NET_XMIT_DROP;
890 }
891
892 static void tun_net_mclist(struct net_device *dev)
893 {
894 /*
895 * This callback is supposed to deal with mc filter in
896 * _rx_ path and has nothing to do with the _tx_ path.
897 * In rx path we always accept everything userspace gives us.
898 */
899 }
900
901 #define MIN_MTU 68
902 #define MAX_MTU 65535
903
904 static int
905 tun_net_change_mtu(struct net_device *dev, int new_mtu)
906 {
907 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
908 return -EINVAL;
909 dev->mtu = new_mtu;
910 return 0;
911 }
912
913 static netdev_features_t tun_net_fix_features(struct net_device *dev,
914 netdev_features_t features)
915 {
916 struct tun_struct *tun = netdev_priv(dev);
917
918 return (features & tun->set_features) | (features & ~TUN_USER_FEATURES);
919 }
920 #ifdef CONFIG_NET_POLL_CONTROLLER
921 static void tun_poll_controller(struct net_device *dev)
922 {
923 /*
924 * Tun only receives frames when:
925 * 1) the char device endpoint gets data from user space
926 * 2) the tun socket gets a sendmsg call from user space
927 * Since both of those are synchronous operations, we are guaranteed
928 * never to have pending data when we poll for it
929 * so there is nothing to do here but return.
930 * We need this though so netpoll recognizes us as an interface that
931 * supports polling, which enables bridge devices in virt setups to
932 * still use netconsole
933 */
934 return;
935 }
936 #endif
937 static const struct net_device_ops tun_netdev_ops = {
938 .ndo_uninit = tun_net_uninit,
939 .ndo_open = tun_net_open,
940 .ndo_stop = tun_net_close,
941 .ndo_start_xmit = tun_net_xmit,
942 .ndo_change_mtu = tun_net_change_mtu,
943 .ndo_fix_features = tun_net_fix_features,
944 .ndo_select_queue = tun_select_queue,
945 #ifdef CONFIG_NET_POLL_CONTROLLER
946 .ndo_poll_controller = tun_poll_controller,
947 #endif
948 };
949
950 static const struct net_device_ops tap_netdev_ops = {
951 .ndo_uninit = tun_net_uninit,
952 .ndo_open = tun_net_open,
953 .ndo_stop = tun_net_close,
954 .ndo_start_xmit = tun_net_xmit,
955 .ndo_change_mtu = tun_net_change_mtu,
956 .ndo_fix_features = tun_net_fix_features,
957 .ndo_set_rx_mode = tun_net_mclist,
958 .ndo_set_mac_address = eth_mac_addr,
959 .ndo_validate_addr = eth_validate_addr,
960 .ndo_select_queue = tun_select_queue,
961 #ifdef CONFIG_NET_POLL_CONTROLLER
962 .ndo_poll_controller = tun_poll_controller,
963 #endif
964 .ndo_features_check = passthru_features_check,
965 };
966
967 static void tun_flow_init(struct tun_struct *tun)
968 {
969 int i;
970
971 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++)
972 INIT_HLIST_HEAD(&tun->flows[i]);
973
974 tun->ageing_time = TUN_FLOW_EXPIRE;
975 setup_timer(&tun->flow_gc_timer, tun_flow_cleanup, (unsigned long)tun);
976 mod_timer(&tun->flow_gc_timer,
977 round_jiffies_up(jiffies + tun->ageing_time));
978 }
979
980 static void tun_flow_uninit(struct tun_struct *tun)
981 {
982 del_timer_sync(&tun->flow_gc_timer);
983 tun_flow_flush(tun);
984 }
985
986 /* Initialize net device. */
987 static void tun_net_init(struct net_device *dev)
988 {
989 struct tun_struct *tun = netdev_priv(dev);
990
991 switch (tun->flags & TUN_TYPE_MASK) {
992 case IFF_TUN:
993 dev->netdev_ops = &tun_netdev_ops;
994
995 /* Point-to-Point TUN Device */
996 dev->hard_header_len = 0;
997 dev->addr_len = 0;
998 dev->mtu = 1500;
999
1000 /* Zero header length */
1001 dev->type = ARPHRD_NONE;
1002 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1003 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
1004 break;
1005
1006 case IFF_TAP:
1007 dev->netdev_ops = &tap_netdev_ops;
1008 /* Ethernet TAP Device */
1009 ether_setup(dev);
1010 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1011 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1012
1013 eth_hw_addr_random(dev);
1014
1015 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
1016 break;
1017 }
1018 }
1019
1020 /* Character device part */
1021
1022 /* Poll */
1023 static unsigned int tun_chr_poll(struct file *file, poll_table *wait)
1024 {
1025 struct tun_file *tfile = file->private_data;
1026 struct tun_struct *tun = __tun_get(tfile);
1027 struct sock *sk;
1028 unsigned int mask = 0;
1029
1030 if (!tun)
1031 return POLLERR;
1032
1033 sk = tfile->socket.sk;
1034
1035 tun_debug(KERN_INFO, tun, "tun_chr_poll\n");
1036
1037 poll_wait(file, sk_sleep(sk), wait);
1038
1039 if (!skb_queue_empty(&sk->sk_receive_queue))
1040 mask |= POLLIN | POLLRDNORM;
1041
1042 if (sock_writeable(sk) ||
1043 (!test_and_set_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
1044 sock_writeable(sk)))
1045 mask |= POLLOUT | POLLWRNORM;
1046
1047 if (tun->dev->reg_state != NETREG_REGISTERED)
1048 mask = POLLERR;
1049
1050 tun_put(tun);
1051 return mask;
1052 }
1053
1054 /* prepad is the amount to reserve at front. len is length after that.
1055 * linear is a hint as to how much to copy (usually headers). */
1056 static struct sk_buff *tun_alloc_skb(struct tun_file *tfile,
1057 size_t prepad, size_t len,
1058 size_t linear, int noblock)
1059 {
1060 struct sock *sk = tfile->socket.sk;
1061 struct sk_buff *skb;
1062 int err;
1063
1064 /* Under a page? Don't bother with paged skb. */
1065 if (prepad + len < PAGE_SIZE || !linear)
1066 linear = len;
1067
1068 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
1069 &err, 0);
1070 if (!skb)
1071 return ERR_PTR(err);
1072
1073 skb_reserve(skb, prepad);
1074 skb_put(skb, linear);
1075 skb->data_len = len - linear;
1076 skb->len += len - linear;
1077
1078 return skb;
1079 }
1080
1081 /* Get packet from user space buffer */
1082 static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
1083 void *msg_control, struct iov_iter *from,
1084 int noblock)
1085 {
1086 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
1087 struct sk_buff *skb;
1088 size_t total_len = iov_iter_count(from);
1089 size_t len = total_len, align = NET_SKB_PAD, linear;
1090 struct virtio_net_hdr gso = { 0 };
1091 int good_linear;
1092 int copylen;
1093 bool zerocopy = false;
1094 int err;
1095 u32 rxhash;
1096 ssize_t n;
1097
1098 if (!(tun->flags & IFF_NO_PI)) {
1099 if (len < sizeof(pi))
1100 return -EINVAL;
1101 len -= sizeof(pi);
1102
1103 n = copy_from_iter(&pi, sizeof(pi), from);
1104 if (n != sizeof(pi))
1105 return -EFAULT;
1106 }
1107
1108 if (tun->flags & IFF_VNET_HDR) {
1109 if (len < tun->vnet_hdr_sz)
1110 return -EINVAL;
1111 len -= tun->vnet_hdr_sz;
1112
1113 n = copy_from_iter(&gso, sizeof(gso), from);
1114 if (n != sizeof(gso))
1115 return -EFAULT;
1116
1117 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
1118 tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2 > tun16_to_cpu(tun, gso.hdr_len))
1119 gso.hdr_len = cpu_to_tun16(tun, tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2);
1120
1121 if (tun16_to_cpu(tun, gso.hdr_len) > len)
1122 return -EINVAL;
1123 iov_iter_advance(from, tun->vnet_hdr_sz - sizeof(gso));
1124 }
1125
1126 if ((tun->flags & TUN_TYPE_MASK) == IFF_TAP) {
1127 align += NET_IP_ALIGN;
1128 if (unlikely(len < ETH_HLEN ||
1129 (gso.hdr_len && tun16_to_cpu(tun, gso.hdr_len) < ETH_HLEN)))
1130 return -EINVAL;
1131 }
1132
1133 good_linear = SKB_MAX_HEAD(align);
1134
1135 if (msg_control) {
1136 struct iov_iter i = *from;
1137
1138 /* There are 256 bytes to be copied in skb, so there is
1139 * enough room for skb expand head in case it is used.
1140 * The rest of the buffer is mapped from userspace.
1141 */
1142 copylen = gso.hdr_len ? tun16_to_cpu(tun, gso.hdr_len) : GOODCOPY_LEN;
1143 if (copylen > good_linear)
1144 copylen = good_linear;
1145 linear = copylen;
1146 iov_iter_advance(&i, copylen);
1147 if (iov_iter_npages(&i, INT_MAX) <= MAX_SKB_FRAGS)
1148 zerocopy = true;
1149 }
1150
1151 if (!zerocopy) {
1152 copylen = len;
1153 if (tun16_to_cpu(tun, gso.hdr_len) > good_linear)
1154 linear = good_linear;
1155 else
1156 linear = tun16_to_cpu(tun, gso.hdr_len);
1157 }
1158
1159 skb = tun_alloc_skb(tfile, align, copylen, linear, noblock);
1160 if (IS_ERR(skb)) {
1161 if (PTR_ERR(skb) != -EAGAIN)
1162 tun->dev->stats.rx_dropped++;
1163 return PTR_ERR(skb);
1164 }
1165
1166 if (zerocopy)
1167 err = zerocopy_sg_from_iter(skb, from);
1168 else {
1169 err = skb_copy_datagram_from_iter(skb, 0, from, len);
1170 if (!err && msg_control) {
1171 struct ubuf_info *uarg = msg_control;
1172 uarg->callback(uarg, false);
1173 }
1174 }
1175
1176 if (err) {
1177 tun->dev->stats.rx_dropped++;
1178 kfree_skb(skb);
1179 return -EFAULT;
1180 }
1181
1182 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
1183 if (!skb_partial_csum_set(skb, tun16_to_cpu(tun, gso.csum_start),
1184 tun16_to_cpu(tun, gso.csum_offset))) {
1185 tun->dev->stats.rx_frame_errors++;
1186 kfree_skb(skb);
1187 return -EINVAL;
1188 }
1189 }
1190
1191 switch (tun->flags & TUN_TYPE_MASK) {
1192 case IFF_TUN:
1193 if (tun->flags & IFF_NO_PI) {
1194 switch (skb->data[0] & 0xf0) {
1195 case 0x40:
1196 pi.proto = htons(ETH_P_IP);
1197 break;
1198 case 0x60:
1199 pi.proto = htons(ETH_P_IPV6);
1200 break;
1201 default:
1202 tun->dev->stats.rx_dropped++;
1203 kfree_skb(skb);
1204 return -EINVAL;
1205 }
1206 }
1207
1208 skb_reset_mac_header(skb);
1209 skb->protocol = pi.proto;
1210 skb->dev = tun->dev;
1211 break;
1212 case IFF_TAP:
1213 skb->protocol = eth_type_trans(skb, tun->dev);
1214 break;
1215 }
1216
1217 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
1218 pr_debug("GSO!\n");
1219 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
1220 case VIRTIO_NET_HDR_GSO_TCPV4:
1221 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
1222 break;
1223 case VIRTIO_NET_HDR_GSO_TCPV6:
1224 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
1225 break;
1226 case VIRTIO_NET_HDR_GSO_UDP:
1227 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
1228 break;
1229 default:
1230 tun->dev->stats.rx_frame_errors++;
1231 kfree_skb(skb);
1232 return -EINVAL;
1233 }
1234
1235 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
1236 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
1237
1238 skb_shinfo(skb)->gso_size = tun16_to_cpu(tun, gso.gso_size);
1239 if (skb_shinfo(skb)->gso_size == 0) {
1240 tun->dev->stats.rx_frame_errors++;
1241 kfree_skb(skb);
1242 return -EINVAL;
1243 }
1244
1245 /* Header must be checked, and gso_segs computed. */
1246 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
1247 skb_shinfo(skb)->gso_segs = 0;
1248 }
1249
1250 /* copy skb_ubuf_info for callback when skb has no error */
1251 if (zerocopy) {
1252 skb_shinfo(skb)->destructor_arg = msg_control;
1253 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1254 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
1255 }
1256
1257 skb_reset_network_header(skb);
1258 skb_probe_transport_header(skb, 0);
1259
1260 rxhash = skb_get_hash(skb);
1261 netif_rx_ni(skb);
1262
1263 tun->dev->stats.rx_packets++;
1264 tun->dev->stats.rx_bytes += len;
1265
1266 tun_flow_update(tun, rxhash, tfile);
1267 return total_len;
1268 }
1269
1270 static ssize_t tun_chr_write_iter(struct kiocb *iocb, struct iov_iter *from)
1271 {
1272 struct file *file = iocb->ki_filp;
1273 struct tun_struct *tun = tun_get(file);
1274 struct tun_file *tfile = file->private_data;
1275 ssize_t result;
1276
1277 if (!tun)
1278 return -EBADFD;
1279
1280 result = tun_get_user(tun, tfile, NULL, from, file->f_flags & O_NONBLOCK);
1281
1282 tun_put(tun);
1283 return result;
1284 }
1285
1286 /* Put packet to the user space buffer */
1287 static ssize_t tun_put_user(struct tun_struct *tun,
1288 struct tun_file *tfile,
1289 struct sk_buff *skb,
1290 struct iov_iter *iter)
1291 {
1292 struct tun_pi pi = { 0, skb->protocol };
1293 ssize_t total;
1294 int vlan_offset = 0;
1295 int vlan_hlen = 0;
1296 int vnet_hdr_sz = 0;
1297
1298 if (skb_vlan_tag_present(skb))
1299 vlan_hlen = VLAN_HLEN;
1300
1301 if (tun->flags & IFF_VNET_HDR)
1302 vnet_hdr_sz = tun->vnet_hdr_sz;
1303
1304 total = skb->len + vlan_hlen + vnet_hdr_sz;
1305
1306 if (!(tun->flags & IFF_NO_PI)) {
1307 if (iov_iter_count(iter) < sizeof(pi))
1308 return -EINVAL;
1309
1310 total += sizeof(pi);
1311 if (iov_iter_count(iter) < total) {
1312 /* Packet will be striped */
1313 pi.flags |= TUN_PKT_STRIP;
1314 }
1315
1316 if (copy_to_iter(&pi, sizeof(pi), iter) != sizeof(pi))
1317 return -EFAULT;
1318 }
1319
1320 if (vnet_hdr_sz) {
1321 struct virtio_net_hdr gso = { 0 }; /* no info leak */
1322 if (iov_iter_count(iter) < vnet_hdr_sz)
1323 return -EINVAL;
1324
1325 if (skb_is_gso(skb)) {
1326 struct skb_shared_info *sinfo = skb_shinfo(skb);
1327
1328 /* This is a hint as to how much should be linear. */
1329 gso.hdr_len = cpu_to_tun16(tun, skb_headlen(skb));
1330 gso.gso_size = cpu_to_tun16(tun, sinfo->gso_size);
1331 if (sinfo->gso_type & SKB_GSO_TCPV4)
1332 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
1333 else if (sinfo->gso_type & SKB_GSO_TCPV6)
1334 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
1335 else if (sinfo->gso_type & SKB_GSO_UDP)
1336 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
1337 else {
1338 pr_err("unexpected GSO type: "
1339 "0x%x, gso_size %d, hdr_len %d\n",
1340 sinfo->gso_type, tun16_to_cpu(tun, gso.gso_size),
1341 tun16_to_cpu(tun, gso.hdr_len));
1342 print_hex_dump(KERN_ERR, "tun: ",
1343 DUMP_PREFIX_NONE,
1344 16, 1, skb->head,
1345 min((int)tun16_to_cpu(tun, gso.hdr_len), 64), true);
1346 WARN_ON_ONCE(1);
1347 return -EINVAL;
1348 }
1349 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
1350 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
1351 } else
1352 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
1353
1354 if (skb->ip_summed == CHECKSUM_PARTIAL) {
1355 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
1356 gso.csum_start = cpu_to_tun16(tun, skb_checksum_start_offset(skb) +
1357 vlan_hlen);
1358 gso.csum_offset = cpu_to_tun16(tun, skb->csum_offset);
1359 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
1360 gso.flags = VIRTIO_NET_HDR_F_DATA_VALID;
1361 } /* else everything is zero */
1362
1363 if (copy_to_iter(&gso, sizeof(gso), iter) != sizeof(gso))
1364 return -EFAULT;
1365
1366 iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso));
1367 }
1368
1369 if (vlan_hlen) {
1370 int ret;
1371 struct {
1372 __be16 h_vlan_proto;
1373 __be16 h_vlan_TCI;
1374 } veth;
1375
1376 veth.h_vlan_proto = skb->vlan_proto;
1377 veth.h_vlan_TCI = htons(skb_vlan_tag_get(skb));
1378
1379 vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);
1380
1381 ret = skb_copy_datagram_iter(skb, 0, iter, vlan_offset);
1382 if (ret || !iov_iter_count(iter))
1383 goto done;
1384
1385 ret = copy_to_iter(&veth, sizeof(veth), iter);
1386 if (ret != sizeof(veth) || !iov_iter_count(iter))
1387 goto done;
1388 }
1389
1390 skb_copy_datagram_iter(skb, vlan_offset, iter, skb->len - vlan_offset);
1391
1392 done:
1393 tun->dev->stats.tx_packets++;
1394 tun->dev->stats.tx_bytes += skb->len + vlan_hlen;
1395
1396 return total;
1397 }
1398
1399 static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
1400 struct iov_iter *to,
1401 int noblock)
1402 {
1403 struct sk_buff *skb;
1404 ssize_t ret;
1405 int peeked, err, off = 0;
1406
1407 tun_debug(KERN_INFO, tun, "tun_do_read\n");
1408
1409 if (!iov_iter_count(to))
1410 return 0;
1411
1412 if (tun->dev->reg_state != NETREG_REGISTERED)
1413 return -EIO;
1414
1415 /* Read frames from queue */
1416 skb = __skb_recv_datagram(tfile->socket.sk, noblock ? MSG_DONTWAIT : 0,
1417 &peeked, &off, &err);
1418 if (!skb)
1419 return err;
1420
1421 ret = tun_put_user(tun, tfile, skb, to);
1422 if (unlikely(ret < 0))
1423 kfree_skb(skb);
1424 else
1425 consume_skb(skb);
1426
1427 return ret;
1428 }
1429
1430 static ssize_t tun_chr_read_iter(struct kiocb *iocb, struct iov_iter *to)
1431 {
1432 struct file *file = iocb->ki_filp;
1433 struct tun_file *tfile = file->private_data;
1434 struct tun_struct *tun = __tun_get(tfile);
1435 ssize_t len = iov_iter_count(to), ret;
1436
1437 if (!tun)
1438 return -EBADFD;
1439 ret = tun_do_read(tun, tfile, to, file->f_flags & O_NONBLOCK);
1440 ret = min_t(ssize_t, ret, len);
1441 if (ret > 0)
1442 iocb->ki_pos = ret;
1443 tun_put(tun);
1444 return ret;
1445 }
1446
1447 static void tun_free_netdev(struct net_device *dev)
1448 {
1449 struct tun_struct *tun = netdev_priv(dev);
1450
1451 BUG_ON(!(list_empty(&tun->disabled)));
1452 tun_flow_uninit(tun);
1453 security_tun_dev_free_security(tun->security);
1454 free_netdev(dev);
1455 }
1456
1457 static void tun_setup(struct net_device *dev)
1458 {
1459 struct tun_struct *tun = netdev_priv(dev);
1460
1461 tun->owner = INVALID_UID;
1462 tun->group = INVALID_GID;
1463
1464 dev->ethtool_ops = &tun_ethtool_ops;
1465 dev->destructor = tun_free_netdev;
1466 }
1467
1468 /* Trivial set of netlink ops to allow deleting tun or tap
1469 * device with netlink.
1470 */
1471 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
1472 {
1473 return -EINVAL;
1474 }
1475
1476 static struct rtnl_link_ops tun_link_ops __read_mostly = {
1477 .kind = DRV_NAME,
1478 .priv_size = sizeof(struct tun_struct),
1479 .setup = tun_setup,
1480 .validate = tun_validate,
1481 };
1482
1483 static void tun_sock_write_space(struct sock *sk)
1484 {
1485 struct tun_file *tfile;
1486 wait_queue_head_t *wqueue;
1487
1488 if (!sock_writeable(sk))
1489 return;
1490
1491 if (!test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags))
1492 return;
1493
1494 wqueue = sk_sleep(sk);
1495 if (wqueue && waitqueue_active(wqueue))
1496 wake_up_interruptible_sync_poll(wqueue, POLLOUT |
1497 POLLWRNORM | POLLWRBAND);
1498
1499 tfile = container_of(sk, struct tun_file, sk);
1500 kill_fasync(&tfile->fasync, SIGIO, POLL_OUT);
1501 }
1502
1503 static int tun_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
1504 {
1505 int ret;
1506 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1507 struct tun_struct *tun = __tun_get(tfile);
1508
1509 if (!tun)
1510 return -EBADFD;
1511
1512 ret = tun_get_user(tun, tfile, m->msg_control, &m->msg_iter,
1513 m->msg_flags & MSG_DONTWAIT);
1514 tun_put(tun);
1515 return ret;
1516 }
1517
1518 static int tun_recvmsg(struct socket *sock, struct msghdr *m, size_t total_len,
1519 int flags)
1520 {
1521 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1522 struct tun_struct *tun = __tun_get(tfile);
1523 int ret;
1524
1525 if (!tun)
1526 return -EBADFD;
1527
1528 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC|MSG_ERRQUEUE)) {
1529 ret = -EINVAL;
1530 goto out;
1531 }
1532 if (flags & MSG_ERRQUEUE) {
1533 ret = sock_recv_errqueue(sock->sk, m, total_len,
1534 SOL_PACKET, TUN_TX_TIMESTAMP);
1535 goto out;
1536 }
1537 ret = tun_do_read(tun, tfile, &m->msg_iter, flags & MSG_DONTWAIT);
1538 if (ret > (ssize_t)total_len) {
1539 m->msg_flags |= MSG_TRUNC;
1540 ret = flags & MSG_TRUNC ? ret : total_len;
1541 }
1542 out:
1543 tun_put(tun);
1544 return ret;
1545 }
1546
1547 /* Ops structure to mimic raw sockets with tun */
1548 static const struct proto_ops tun_socket_ops = {
1549 .sendmsg = tun_sendmsg,
1550 .recvmsg = tun_recvmsg,
1551 };
1552
1553 static struct proto tun_proto = {
1554 .name = "tun",
1555 .owner = THIS_MODULE,
1556 .obj_size = sizeof(struct tun_file),
1557 };
1558
1559 static int tun_flags(struct tun_struct *tun)
1560 {
1561 return tun->flags & (TUN_FEATURES | IFF_PERSIST | IFF_TUN | IFF_TAP);
1562 }
1563
1564 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
1565 char *buf)
1566 {
1567 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1568 return sprintf(buf, "0x%x\n", tun_flags(tun));
1569 }
1570
1571 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
1572 char *buf)
1573 {
1574 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1575 return uid_valid(tun->owner)?
1576 sprintf(buf, "%u\n",
1577 from_kuid_munged(current_user_ns(), tun->owner)):
1578 sprintf(buf, "-1\n");
1579 }
1580
1581 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
1582 char *buf)
1583 {
1584 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1585 return gid_valid(tun->group) ?
1586 sprintf(buf, "%u\n",
1587 from_kgid_munged(current_user_ns(), tun->group)):
1588 sprintf(buf, "-1\n");
1589 }
1590
1591 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
1592 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
1593 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
1594
1595 static struct attribute *tun_dev_attrs[] = {
1596 &dev_attr_tun_flags.attr,
1597 &dev_attr_owner.attr,
1598 &dev_attr_group.attr,
1599 NULL
1600 };
1601
1602 static const struct attribute_group tun_attr_group = {
1603 .attrs = tun_dev_attrs
1604 };
1605
1606 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
1607 {
1608 struct tun_struct *tun;
1609 struct tun_file *tfile = file->private_data;
1610 struct net_device *dev;
1611 int err;
1612
1613 if (tfile->detached)
1614 return -EINVAL;
1615
1616 dev = __dev_get_by_name(net, ifr->ifr_name);
1617 if (dev) {
1618 if (ifr->ifr_flags & IFF_TUN_EXCL)
1619 return -EBUSY;
1620 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
1621 tun = netdev_priv(dev);
1622 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
1623 tun = netdev_priv(dev);
1624 else
1625 return -EINVAL;
1626
1627 if (!!(ifr->ifr_flags & IFF_MULTI_QUEUE) !=
1628 !!(tun->flags & IFF_MULTI_QUEUE))
1629 return -EINVAL;
1630
1631 if (tun_not_capable(tun))
1632 return -EPERM;
1633 err = security_tun_dev_open(tun->security);
1634 if (err < 0)
1635 return err;
1636
1637 err = tun_attach(tun, file, ifr->ifr_flags & IFF_NOFILTER);
1638 if (err < 0)
1639 return err;
1640
1641 if (tun->flags & IFF_MULTI_QUEUE &&
1642 (tun->numqueues + tun->numdisabled > 1)) {
1643 /* One or more queue has already been attached, no need
1644 * to initialize the device again.
1645 */
1646 return 0;
1647 }
1648 }
1649 else {
1650 char *name;
1651 unsigned long flags = 0;
1652 int queues = ifr->ifr_flags & IFF_MULTI_QUEUE ?
1653 MAX_TAP_QUEUES : 1;
1654
1655 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1656 return -EPERM;
1657 err = security_tun_dev_create();
1658 if (err < 0)
1659 return err;
1660
1661 /* Set dev type */
1662 if (ifr->ifr_flags & IFF_TUN) {
1663 /* TUN device */
1664 flags |= IFF_TUN;
1665 name = "tun%d";
1666 } else if (ifr->ifr_flags & IFF_TAP) {
1667 /* TAP device */
1668 flags |= IFF_TAP;
1669 name = "tap%d";
1670 } else
1671 return -EINVAL;
1672
1673 if (*ifr->ifr_name)
1674 name = ifr->ifr_name;
1675
1676 dev = alloc_netdev_mqs(sizeof(struct tun_struct), name,
1677 NET_NAME_UNKNOWN, tun_setup, queues,
1678 queues);
1679
1680 if (!dev)
1681 return -ENOMEM;
1682
1683 dev_net_set(dev, net);
1684 dev->rtnl_link_ops = &tun_link_ops;
1685 dev->ifindex = tfile->ifindex;
1686 dev->sysfs_groups[0] = &tun_attr_group;
1687
1688 tun = netdev_priv(dev);
1689 tun->dev = dev;
1690 tun->flags = flags;
1691 tun->txflt.count = 0;
1692 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
1693
1694 tun->filter_attached = false;
1695 tun->sndbuf = tfile->socket.sk->sk_sndbuf;
1696
1697 spin_lock_init(&tun->lock);
1698
1699 err = security_tun_dev_alloc_security(&tun->security);
1700 if (err < 0)
1701 goto err_free_dev;
1702
1703 tun_net_init(dev);
1704 tun_flow_init(tun);
1705
1706 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
1707 TUN_USER_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
1708 NETIF_F_HW_VLAN_STAG_TX;
1709 dev->features = dev->hw_features;
1710 dev->vlan_features = dev->features &
1711 ~(NETIF_F_HW_VLAN_CTAG_TX |
1712 NETIF_F_HW_VLAN_STAG_TX);
1713
1714 INIT_LIST_HEAD(&tun->disabled);
1715 err = tun_attach(tun, file, false);
1716 if (err < 0)
1717 goto err_free_flow;
1718
1719 err = register_netdevice(tun->dev);
1720 if (err < 0)
1721 goto err_detach;
1722 }
1723
1724 netif_carrier_on(tun->dev);
1725
1726 tun_debug(KERN_INFO, tun, "tun_set_iff\n");
1727
1728 tun->flags = (tun->flags & ~TUN_FEATURES) |
1729 (ifr->ifr_flags & TUN_FEATURES);
1730
1731 /* Make sure persistent devices do not get stuck in
1732 * xoff state.
1733 */
1734 if (netif_running(tun->dev))
1735 netif_tx_wake_all_queues(tun->dev);
1736
1737 strcpy(ifr->ifr_name, tun->dev->name);
1738 return 0;
1739
1740 err_detach:
1741 tun_detach_all(dev);
1742 err_free_flow:
1743 tun_flow_uninit(tun);
1744 security_tun_dev_free_security(tun->security);
1745 err_free_dev:
1746 free_netdev(dev);
1747 return err;
1748 }
1749
1750 static void tun_get_iff(struct net *net, struct tun_struct *tun,
1751 struct ifreq *ifr)
1752 {
1753 tun_debug(KERN_INFO, tun, "tun_get_iff\n");
1754
1755 strcpy(ifr->ifr_name, tun->dev->name);
1756
1757 ifr->ifr_flags = tun_flags(tun);
1758
1759 }
1760
1761 /* This is like a cut-down ethtool ops, except done via tun fd so no
1762 * privs required. */
1763 static int set_offload(struct tun_struct *tun, unsigned long arg)
1764 {
1765 netdev_features_t features = 0;
1766
1767 if (arg & TUN_F_CSUM) {
1768 features |= NETIF_F_HW_CSUM;
1769 arg &= ~TUN_F_CSUM;
1770
1771 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1772 if (arg & TUN_F_TSO_ECN) {
1773 features |= NETIF_F_TSO_ECN;
1774 arg &= ~TUN_F_TSO_ECN;
1775 }
1776 if (arg & TUN_F_TSO4)
1777 features |= NETIF_F_TSO;
1778 if (arg & TUN_F_TSO6)
1779 features |= NETIF_F_TSO6;
1780 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1781 }
1782
1783 if (arg & TUN_F_UFO) {
1784 features |= NETIF_F_UFO;
1785 arg &= ~TUN_F_UFO;
1786 }
1787 }
1788
1789 /* This gives the user a way to test for new features in future by
1790 * trying to set them. */
1791 if (arg)
1792 return -EINVAL;
1793
1794 tun->set_features = features;
1795 netdev_update_features(tun->dev);
1796
1797 return 0;
1798 }
1799
1800 static void tun_detach_filter(struct tun_struct *tun, int n)
1801 {
1802 int i;
1803 struct tun_file *tfile;
1804
1805 for (i = 0; i < n; i++) {
1806 tfile = rtnl_dereference(tun->tfiles[i]);
1807 sk_detach_filter(tfile->socket.sk);
1808 }
1809
1810 tun->filter_attached = false;
1811 }
1812
1813 static int tun_attach_filter(struct tun_struct *tun)
1814 {
1815 int i, ret = 0;
1816 struct tun_file *tfile;
1817
1818 for (i = 0; i < tun->numqueues; i++) {
1819 tfile = rtnl_dereference(tun->tfiles[i]);
1820 ret = sk_attach_filter(&tun->fprog, tfile->socket.sk);
1821 if (ret) {
1822 tun_detach_filter(tun, i);
1823 return ret;
1824 }
1825 }
1826
1827 tun->filter_attached = true;
1828 return ret;
1829 }
1830
1831 static void tun_set_sndbuf(struct tun_struct *tun)
1832 {
1833 struct tun_file *tfile;
1834 int i;
1835
1836 for (i = 0; i < tun->numqueues; i++) {
1837 tfile = rtnl_dereference(tun->tfiles[i]);
1838 tfile->socket.sk->sk_sndbuf = tun->sndbuf;
1839 }
1840 }
1841
1842 static int tun_set_queue(struct file *file, struct ifreq *ifr)
1843 {
1844 struct tun_file *tfile = file->private_data;
1845 struct tun_struct *tun;
1846 int ret = 0;
1847
1848 rtnl_lock();
1849
1850 if (ifr->ifr_flags & IFF_ATTACH_QUEUE) {
1851 tun = tfile->detached;
1852 if (!tun) {
1853 ret = -EINVAL;
1854 goto unlock;
1855 }
1856 ret = security_tun_dev_attach_queue(tun->security);
1857 if (ret < 0)
1858 goto unlock;
1859 ret = tun_attach(tun, file, false);
1860 } else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
1861 tun = rtnl_dereference(tfile->tun);
1862 if (!tun || !(tun->flags & IFF_MULTI_QUEUE) || tfile->detached)
1863 ret = -EINVAL;
1864 else
1865 __tun_detach(tfile, false);
1866 } else
1867 ret = -EINVAL;
1868
1869 unlock:
1870 rtnl_unlock();
1871 return ret;
1872 }
1873
1874 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
1875 unsigned long arg, int ifreq_len)
1876 {
1877 struct tun_file *tfile = file->private_data;
1878 struct tun_struct *tun;
1879 void __user* argp = (void __user*)arg;
1880 struct ifreq ifr;
1881 kuid_t owner;
1882 kgid_t group;
1883 int sndbuf;
1884 int vnet_hdr_sz;
1885 unsigned int ifindex;
1886 int le;
1887 int ret;
1888
1889 if (cmd == TUNSETIFF || cmd == TUNSETQUEUE || _IOC_TYPE(cmd) == 0x89) {
1890 if (copy_from_user(&ifr, argp, ifreq_len))
1891 return -EFAULT;
1892 } else {
1893 memset(&ifr, 0, sizeof(ifr));
1894 }
1895 if (cmd == TUNGETFEATURES) {
1896 /* Currently this just means: "what IFF flags are valid?".
1897 * This is needed because we never checked for invalid flags on
1898 * TUNSETIFF.
1899 */
1900 return put_user(IFF_TUN | IFF_TAP | TUN_FEATURES,
1901 (unsigned int __user*)argp);
1902 } else if (cmd == TUNSETQUEUE)
1903 return tun_set_queue(file, &ifr);
1904
1905 ret = 0;
1906 rtnl_lock();
1907
1908 tun = __tun_get(tfile);
1909 if (cmd == TUNSETIFF && !tun) {
1910 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1911
1912 ret = tun_set_iff(sock_net(&tfile->sk), file, &ifr);
1913
1914 if (ret)
1915 goto unlock;
1916
1917 if (copy_to_user(argp, &ifr, ifreq_len))
1918 ret = -EFAULT;
1919 goto unlock;
1920 }
1921 if (cmd == TUNSETIFINDEX) {
1922 ret = -EPERM;
1923 if (tun)
1924 goto unlock;
1925
1926 ret = -EFAULT;
1927 if (copy_from_user(&ifindex, argp, sizeof(ifindex)))
1928 goto unlock;
1929
1930 ret = 0;
1931 tfile->ifindex = ifindex;
1932 goto unlock;
1933 }
1934
1935 ret = -EBADFD;
1936 if (!tun)
1937 goto unlock;
1938
1939 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %u\n", cmd);
1940
1941 ret = 0;
1942 switch (cmd) {
1943 case TUNGETIFF:
1944 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1945
1946 if (tfile->detached)
1947 ifr.ifr_flags |= IFF_DETACH_QUEUE;
1948 if (!tfile->socket.sk->sk_filter)
1949 ifr.ifr_flags |= IFF_NOFILTER;
1950
1951 if (copy_to_user(argp, &ifr, ifreq_len))
1952 ret = -EFAULT;
1953 break;
1954
1955 case TUNSETNOCSUM:
1956 /* Disable/Enable checksum */
1957
1958 /* [unimplemented] */
1959 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n",
1960 arg ? "disabled" : "enabled");
1961 break;
1962
1963 case TUNSETPERSIST:
1964 /* Disable/Enable persist mode. Keep an extra reference to the
1965 * module to prevent the module being unprobed.
1966 */
1967 if (arg && !(tun->flags & IFF_PERSIST)) {
1968 tun->flags |= IFF_PERSIST;
1969 __module_get(THIS_MODULE);
1970 }
1971 if (!arg && (tun->flags & IFF_PERSIST)) {
1972 tun->flags &= ~IFF_PERSIST;
1973 module_put(THIS_MODULE);
1974 }
1975
1976 tun_debug(KERN_INFO, tun, "persist %s\n",
1977 arg ? "enabled" : "disabled");
1978 break;
1979
1980 case TUNSETOWNER:
1981 /* Set owner of the device */
1982 owner = make_kuid(current_user_ns(), arg);
1983 if (!uid_valid(owner)) {
1984 ret = -EINVAL;
1985 break;
1986 }
1987 tun->owner = owner;
1988 tun_debug(KERN_INFO, tun, "owner set to %u\n",
1989 from_kuid(&init_user_ns, tun->owner));
1990 break;
1991
1992 case TUNSETGROUP:
1993 /* Set group of the device */
1994 group = make_kgid(current_user_ns(), arg);
1995 if (!gid_valid(group)) {
1996 ret = -EINVAL;
1997 break;
1998 }
1999 tun->group = group;
2000 tun_debug(KERN_INFO, tun, "group set to %u\n",
2001 from_kgid(&init_user_ns, tun->group));
2002 break;
2003
2004 case TUNSETLINK:
2005 /* Only allow setting the type when the interface is down */
2006 if (tun->dev->flags & IFF_UP) {
2007 tun_debug(KERN_INFO, tun,
2008 "Linktype set failed because interface is up\n");
2009 ret = -EBUSY;
2010 } else {
2011 tun->dev->type = (int) arg;
2012 tun_debug(KERN_INFO, tun, "linktype set to %d\n",
2013 tun->dev->type);
2014 ret = 0;
2015 }
2016 break;
2017
2018 #ifdef TUN_DEBUG
2019 case TUNSETDEBUG:
2020 tun->debug = arg;
2021 break;
2022 #endif
2023 case TUNSETOFFLOAD:
2024 ret = set_offload(tun, arg);
2025 break;
2026
2027 case TUNSETTXFILTER:
2028 /* Can be set only for TAPs */
2029 ret = -EINVAL;
2030 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2031 break;
2032 ret = update_filter(&tun->txflt, (void __user *)arg);
2033 break;
2034
2035 case SIOCGIFHWADDR:
2036 /* Get hw address */
2037 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
2038 ifr.ifr_hwaddr.sa_family = tun->dev->type;
2039 if (copy_to_user(argp, &ifr, ifreq_len))
2040 ret = -EFAULT;
2041 break;
2042
2043 case SIOCSIFHWADDR:
2044 /* Set hw address */
2045 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
2046 ifr.ifr_hwaddr.sa_data);
2047
2048 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
2049 break;
2050
2051 case TUNGETSNDBUF:
2052 sndbuf = tfile->socket.sk->sk_sndbuf;
2053 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
2054 ret = -EFAULT;
2055 break;
2056
2057 case TUNSETSNDBUF:
2058 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
2059 ret = -EFAULT;
2060 break;
2061 }
2062
2063 tun->sndbuf = sndbuf;
2064 tun_set_sndbuf(tun);
2065 break;
2066
2067 case TUNGETVNETHDRSZ:
2068 vnet_hdr_sz = tun->vnet_hdr_sz;
2069 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
2070 ret = -EFAULT;
2071 break;
2072
2073 case TUNSETVNETHDRSZ:
2074 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
2075 ret = -EFAULT;
2076 break;
2077 }
2078 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
2079 ret = -EINVAL;
2080 break;
2081 }
2082
2083 tun->vnet_hdr_sz = vnet_hdr_sz;
2084 break;
2085
2086 case TUNGETVNETLE:
2087 le = !!(tun->flags & TUN_VNET_LE);
2088 if (put_user(le, (int __user *)argp))
2089 ret = -EFAULT;
2090 break;
2091
2092 case TUNSETVNETLE:
2093 if (get_user(le, (int __user *)argp)) {
2094 ret = -EFAULT;
2095 break;
2096 }
2097 if (le)
2098 tun->flags |= TUN_VNET_LE;
2099 else
2100 tun->flags &= ~TUN_VNET_LE;
2101 break;
2102
2103 case TUNGETVNETBE:
2104 ret = tun_get_vnet_be(tun, argp);
2105 break;
2106
2107 case TUNSETVNETBE:
2108 ret = tun_set_vnet_be(tun, argp);
2109 break;
2110
2111 case TUNATTACHFILTER:
2112 /* Can be set only for TAPs */
2113 ret = -EINVAL;
2114 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2115 break;
2116 ret = -EFAULT;
2117 if (copy_from_user(&tun->fprog, argp, sizeof(tun->fprog)))
2118 break;
2119
2120 ret = tun_attach_filter(tun);
2121 break;
2122
2123 case TUNDETACHFILTER:
2124 /* Can be set only for TAPs */
2125 ret = -EINVAL;
2126 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2127 break;
2128 ret = 0;
2129 tun_detach_filter(tun, tun->numqueues);
2130 break;
2131
2132 case TUNGETFILTER:
2133 ret = -EINVAL;
2134 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2135 break;
2136 ret = -EFAULT;
2137 if (copy_to_user(argp, &tun->fprog, sizeof(tun->fprog)))
2138 break;
2139 ret = 0;
2140 break;
2141
2142 default:
2143 ret = -EINVAL;
2144 break;
2145 }
2146
2147 unlock:
2148 rtnl_unlock();
2149 if (tun)
2150 tun_put(tun);
2151 return ret;
2152 }
2153
2154 static long tun_chr_ioctl(struct file *file,
2155 unsigned int cmd, unsigned long arg)
2156 {
2157 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
2158 }
2159
2160 #ifdef CONFIG_COMPAT
2161 static long tun_chr_compat_ioctl(struct file *file,
2162 unsigned int cmd, unsigned long arg)
2163 {
2164 switch (cmd) {
2165 case TUNSETIFF:
2166 case TUNGETIFF:
2167 case TUNSETTXFILTER:
2168 case TUNGETSNDBUF:
2169 case TUNSETSNDBUF:
2170 case SIOCGIFHWADDR:
2171 case SIOCSIFHWADDR:
2172 arg = (unsigned long)compat_ptr(arg);
2173 break;
2174 default:
2175 arg = (compat_ulong_t)arg;
2176 break;
2177 }
2178
2179 /*
2180 * compat_ifreq is shorter than ifreq, so we must not access beyond
2181 * the end of that structure. All fields that are used in this
2182 * driver are compatible though, we don't need to convert the
2183 * contents.
2184 */
2185 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
2186 }
2187 #endif /* CONFIG_COMPAT */
2188
2189 static int tun_chr_fasync(int fd, struct file *file, int on)
2190 {
2191 struct tun_file *tfile = file->private_data;
2192 int ret;
2193
2194 if ((ret = fasync_helper(fd, file, on, &tfile->fasync)) < 0)
2195 goto out;
2196
2197 if (on) {
2198 __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
2199 tfile->flags |= TUN_FASYNC;
2200 } else
2201 tfile->flags &= ~TUN_FASYNC;
2202 ret = 0;
2203 out:
2204 return ret;
2205 }
2206
2207 static int tun_chr_open(struct inode *inode, struct file * file)
2208 {
2209 struct net *net = current->nsproxy->net_ns;
2210 struct tun_file *tfile;
2211
2212 DBG1(KERN_INFO, "tunX: tun_chr_open\n");
2213
2214 tfile = (struct tun_file *)sk_alloc(net, AF_UNSPEC, GFP_KERNEL,
2215 &tun_proto, 0);
2216 if (!tfile)
2217 return -ENOMEM;
2218 RCU_INIT_POINTER(tfile->tun, NULL);
2219 tfile->flags = 0;
2220 tfile->ifindex = 0;
2221
2222 init_waitqueue_head(&tfile->wq.wait);
2223 RCU_INIT_POINTER(tfile->socket.wq, &tfile->wq);
2224
2225 tfile->socket.file = file;
2226 tfile->socket.ops = &tun_socket_ops;
2227
2228 sock_init_data(&tfile->socket, &tfile->sk);
2229
2230 tfile->sk.sk_write_space = tun_sock_write_space;
2231 tfile->sk.sk_sndbuf = INT_MAX;
2232
2233 file->private_data = tfile;
2234 INIT_LIST_HEAD(&tfile->next);
2235
2236 sock_set_flag(&tfile->sk, SOCK_ZEROCOPY);
2237
2238 return 0;
2239 }
2240
2241 static int tun_chr_close(struct inode *inode, struct file *file)
2242 {
2243 struct tun_file *tfile = file->private_data;
2244
2245 tun_detach(tfile, true);
2246
2247 return 0;
2248 }
2249
2250 #ifdef CONFIG_PROC_FS
2251 static void tun_chr_show_fdinfo(struct seq_file *m, struct file *f)
2252 {
2253 struct tun_struct *tun;
2254 struct ifreq ifr;
2255
2256 memset(&ifr, 0, sizeof(ifr));
2257
2258 rtnl_lock();
2259 tun = tun_get(f);
2260 if (tun)
2261 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
2262 rtnl_unlock();
2263
2264 if (tun)
2265 tun_put(tun);
2266
2267 seq_printf(m, "iff:\t%s\n", ifr.ifr_name);
2268 }
2269 #endif
2270
2271 static const struct file_operations tun_fops = {
2272 .owner = THIS_MODULE,
2273 .llseek = no_llseek,
2274 .read_iter = tun_chr_read_iter,
2275 .write_iter = tun_chr_write_iter,
2276 .poll = tun_chr_poll,
2277 .unlocked_ioctl = tun_chr_ioctl,
2278 #ifdef CONFIG_COMPAT
2279 .compat_ioctl = tun_chr_compat_ioctl,
2280 #endif
2281 .open = tun_chr_open,
2282 .release = tun_chr_close,
2283 .fasync = tun_chr_fasync,
2284 #ifdef CONFIG_PROC_FS
2285 .show_fdinfo = tun_chr_show_fdinfo,
2286 #endif
2287 };
2288
2289 static struct miscdevice tun_miscdev = {
2290 .minor = TUN_MINOR,
2291 .name = "tun",
2292 .nodename = "net/tun",
2293 .fops = &tun_fops,
2294 };
2295
2296 /* ethtool interface */
2297
2298 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
2299 {
2300 cmd->supported = 0;
2301 cmd->advertising = 0;
2302 ethtool_cmd_speed_set(cmd, SPEED_10);
2303 cmd->duplex = DUPLEX_FULL;
2304 cmd->port = PORT_TP;
2305 cmd->phy_address = 0;
2306 cmd->transceiver = XCVR_INTERNAL;
2307 cmd->autoneg = AUTONEG_DISABLE;
2308 cmd->maxtxpkt = 0;
2309 cmd->maxrxpkt = 0;
2310 return 0;
2311 }
2312
2313 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
2314 {
2315 struct tun_struct *tun = netdev_priv(dev);
2316
2317 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
2318 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
2319
2320 switch (tun->flags & TUN_TYPE_MASK) {
2321 case IFF_TUN:
2322 strlcpy(info->bus_info, "tun", sizeof(info->bus_info));
2323 break;
2324 case IFF_TAP:
2325 strlcpy(info->bus_info, "tap", sizeof(info->bus_info));
2326 break;
2327 }
2328 }
2329
2330 static u32 tun_get_msglevel(struct net_device *dev)
2331 {
2332 #ifdef TUN_DEBUG
2333 struct tun_struct *tun = netdev_priv(dev);
2334 return tun->debug;
2335 #else
2336 return -EOPNOTSUPP;
2337 #endif
2338 }
2339
2340 static void tun_set_msglevel(struct net_device *dev, u32 value)
2341 {
2342 #ifdef TUN_DEBUG
2343 struct tun_struct *tun = netdev_priv(dev);
2344 tun->debug = value;
2345 #endif
2346 }
2347
2348 static const struct ethtool_ops tun_ethtool_ops = {
2349 .get_settings = tun_get_settings,
2350 .get_drvinfo = tun_get_drvinfo,
2351 .get_msglevel = tun_get_msglevel,
2352 .set_msglevel = tun_set_msglevel,
2353 .get_link = ethtool_op_get_link,
2354 .get_ts_info = ethtool_op_get_ts_info,
2355 };
2356
2357
2358 static int __init tun_init(void)
2359 {
2360 int ret = 0;
2361
2362 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
2363 pr_info("%s\n", DRV_COPYRIGHT);
2364
2365 ret = rtnl_link_register(&tun_link_ops);
2366 if (ret) {
2367 pr_err("Can't register link_ops\n");
2368 goto err_linkops;
2369 }
2370
2371 ret = misc_register(&tun_miscdev);
2372 if (ret) {
2373 pr_err("Can't register misc device %d\n", TUN_MINOR);
2374 goto err_misc;
2375 }
2376 return 0;
2377 err_misc:
2378 rtnl_link_unregister(&tun_link_ops);
2379 err_linkops:
2380 return ret;
2381 }
2382
2383 static void tun_cleanup(void)
2384 {
2385 misc_deregister(&tun_miscdev);
2386 rtnl_link_unregister(&tun_link_ops);
2387 }
2388
2389 /* Get an underlying socket object from tun file. Returns error unless file is
2390 * attached to a device. The returned object works like a packet socket, it
2391 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
2392 * holding a reference to the file for as long as the socket is in use. */
2393 struct socket *tun_get_socket(struct file *file)
2394 {
2395 struct tun_file *tfile;
2396 if (file->f_op != &tun_fops)
2397 return ERR_PTR(-EINVAL);
2398 tfile = file->private_data;
2399 if (!tfile)
2400 return ERR_PTR(-EBADFD);
2401 return &tfile->socket;
2402 }
2403 EXPORT_SYMBOL_GPL(tun_get_socket);
2404
2405 module_init(tun_init);
2406 module_exit(tun_cleanup);
2407 MODULE_DESCRIPTION(DRV_DESCRIPTION);
2408 MODULE_AUTHOR(DRV_COPYRIGHT);
2409 MODULE_LICENSE("GPL");
2410 MODULE_ALIAS_MISCDEV(TUN_MINOR);
2411 MODULE_ALIAS("devname:net/tun");
Linux with added FPC-III support