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ARM: dts: add 'dr_mode' property to hsotg devices for exynos boards
[linux/fpc-iii.git] / drivers / net / tun.c
blob8c8dc16839a79473e976d9de2132cc6df911e418
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/ipv6.h>
69 #include <net/net_namespace.h>
70 #include <net/netns/generic.h>
71 #include <net/rtnetlink.h>
72 #include <net/sock.h>
73 #include <linux/seq_file.h>
74 #include <linux/uio.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
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 /* DEFAULT_MAX_NUM_RSS_QUEUES were chosen to let the rx/tx queues allocated for
128 * the netdevice to be fit in one page. So we can make sure the success of
129 * memory allocation. TODO: increase the limit. */
130 #define MAX_TAP_QUEUES DEFAULT_MAX_NUM_RSS_QUEUES
131 #define MAX_TAP_FLOWS 4096
132
133 #define TUN_FLOW_EXPIRE (3 * HZ)
134
135 /* A tun_file connects an open character device to a tuntap netdevice. It
136 * also contains all socket related structures (except sock_fprog and tap_filter)
137 * to serve as one transmit queue for tuntap device. The sock_fprog and
138 * tap_filter were kept in tun_struct since they were used for filtering for the
139 * netdevice not for a specific queue (at least I didn't see the requirement for
140 * this).
141 *
142 * RCU usage:
143 * The tun_file and tun_struct are loosely coupled, the pointer from one to the
144 * other can only be read while rcu_read_lock or rtnl_lock is held.
145 */
146 struct tun_file {
147 struct sock sk;
148 struct socket socket;
149 struct socket_wq wq;
150 struct tun_struct __rcu *tun;
151 struct net *net;
152 struct fasync_struct *fasync;
153 /* only used for fasnyc */
154 unsigned int flags;
155 union {
156 u16 queue_index;
157 unsigned int ifindex;
158 };
159 struct list_head next;
160 struct tun_struct *detached;
161 };
162
163 struct tun_flow_entry {
164 struct hlist_node hash_link;
165 struct rcu_head rcu;
166 struct tun_struct *tun;
167
168 u32 rxhash;
169 u32 rps_rxhash;
170 int queue_index;
171 unsigned long updated;
172 };
173
174 #define TUN_NUM_FLOW_ENTRIES 1024
175
176 /* Since the socket were moved to tun_file, to preserve the behavior of persist
177 * device, socket filter, sndbuf and vnet header size were restore when the
178 * file were attached to a persist device.
179 */
180 struct tun_struct {
181 struct tun_file __rcu *tfiles[MAX_TAP_QUEUES];
182 unsigned int numqueues;
183 unsigned int flags;
184 kuid_t owner;
185 kgid_t group;
186
187 struct net_device *dev;
188 netdev_features_t set_features;
189 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
190 NETIF_F_TSO6)
191
192 int vnet_hdr_sz;
193 int sndbuf;
194 struct tap_filter txflt;
195 struct sock_fprog fprog;
196 /* protected by rtnl lock */
197 bool filter_attached;
198 #ifdef TUN_DEBUG
199 int debug;
200 #endif
201 spinlock_t lock;
202 struct hlist_head flows[TUN_NUM_FLOW_ENTRIES];
203 struct timer_list flow_gc_timer;
204 unsigned long ageing_time;
205 unsigned int numdisabled;
206 struct list_head disabled;
207 void *security;
208 u32 flow_count;
209 };
210
211 static inline u16 tun16_to_cpu(struct tun_struct *tun, __virtio16 val)
212 {
213 return __virtio16_to_cpu(tun->flags & TUN_VNET_LE, val);
214 }
215
216 static inline __virtio16 cpu_to_tun16(struct tun_struct *tun, u16 val)
217 {
218 return __cpu_to_virtio16(tun->flags & TUN_VNET_LE, val);
219 }
220
221 static inline u32 tun_hashfn(u32 rxhash)
222 {
223 return rxhash & 0x3ff;
224 }
225
226 static struct tun_flow_entry *tun_flow_find(struct hlist_head *head, u32 rxhash)
227 {
228 struct tun_flow_entry *e;
229
230 hlist_for_each_entry_rcu(e, head, hash_link) {
231 if (e->rxhash == rxhash)
232 return e;
233 }
234 return NULL;
235 }
236
237 static struct tun_flow_entry *tun_flow_create(struct tun_struct *tun,
238 struct hlist_head *head,
239 u32 rxhash, u16 queue_index)
240 {
241 struct tun_flow_entry *e = kmalloc(sizeof(*e), GFP_ATOMIC);
242
243 if (e) {
244 tun_debug(KERN_INFO, tun, "create flow: hash %u index %u\n",
245 rxhash, queue_index);
246 e->updated = jiffies;
247 e->rxhash = rxhash;
248 e->rps_rxhash = 0;
249 e->queue_index = queue_index;
250 e->tun = tun;
251 hlist_add_head_rcu(&e->hash_link, head);
252 ++tun->flow_count;
253 }
254 return e;
255 }
256
257 static void tun_flow_delete(struct tun_struct *tun, struct tun_flow_entry *e)
258 {
259 tun_debug(KERN_INFO, tun, "delete flow: hash %u index %u\n",
260 e->rxhash, e->queue_index);
261 sock_rps_reset_flow_hash(e->rps_rxhash);
262 hlist_del_rcu(&e->hash_link);
263 kfree_rcu(e, rcu);
264 --tun->flow_count;
265 }
266
267 static void tun_flow_flush(struct tun_struct *tun)
268 {
269 int i;
270
271 spin_lock_bh(&tun->lock);
272 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
273 struct tun_flow_entry *e;
274 struct hlist_node *n;
275
276 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link)
277 tun_flow_delete(tun, e);
278 }
279 spin_unlock_bh(&tun->lock);
280 }
281
282 static void tun_flow_delete_by_queue(struct tun_struct *tun, u16 queue_index)
283 {
284 int i;
285
286 spin_lock_bh(&tun->lock);
287 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
288 struct tun_flow_entry *e;
289 struct hlist_node *n;
290
291 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
292 if (e->queue_index == queue_index)
293 tun_flow_delete(tun, e);
294 }
295 }
296 spin_unlock_bh(&tun->lock);
297 }
298
299 static void tun_flow_cleanup(unsigned long data)
300 {
301 struct tun_struct *tun = (struct tun_struct *)data;
302 unsigned long delay = tun->ageing_time;
303 unsigned long next_timer = jiffies + delay;
304 unsigned long count = 0;
305 int i;
306
307 tun_debug(KERN_INFO, tun, "tun_flow_cleanup\n");
308
309 spin_lock_bh(&tun->lock);
310 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
311 struct tun_flow_entry *e;
312 struct hlist_node *n;
313
314 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
315 unsigned long this_timer;
316 count++;
317 this_timer = e->updated + delay;
318 if (time_before_eq(this_timer, jiffies))
319 tun_flow_delete(tun, e);
320 else if (time_before(this_timer, next_timer))
321 next_timer = this_timer;
322 }
323 }
324
325 if (count)
326 mod_timer(&tun->flow_gc_timer, round_jiffies_up(next_timer));
327 spin_unlock_bh(&tun->lock);
328 }
329
330 static void tun_flow_update(struct tun_struct *tun, u32 rxhash,
331 struct tun_file *tfile)
332 {
333 struct hlist_head *head;
334 struct tun_flow_entry *e;
335 unsigned long delay = tun->ageing_time;
336 u16 queue_index = tfile->queue_index;
337
338 if (!rxhash)
339 return;
340 else
341 head = &tun->flows[tun_hashfn(rxhash)];
342
343 rcu_read_lock();
344
345 /* We may get a very small possibility of OOO during switching, not
346 * worth to optimize.*/
347 if (tun->numqueues == 1 || tfile->detached)
348 goto unlock;
349
350 e = tun_flow_find(head, rxhash);
351 if (likely(e)) {
352 /* TODO: keep queueing to old queue until it's empty? */
353 e->queue_index = queue_index;
354 e->updated = jiffies;
355 sock_rps_record_flow_hash(e->rps_rxhash);
356 } else {
357 spin_lock_bh(&tun->lock);
358 if (!tun_flow_find(head, rxhash) &&
359 tun->flow_count < MAX_TAP_FLOWS)
360 tun_flow_create(tun, head, rxhash, queue_index);
361
362 if (!timer_pending(&tun->flow_gc_timer))
363 mod_timer(&tun->flow_gc_timer,
364 round_jiffies_up(jiffies + delay));
365 spin_unlock_bh(&tun->lock);
366 }
367
368 unlock:
369 rcu_read_unlock();
370 }
371
372 /**
373 * Save the hash received in the stack receive path and update the
374 * flow_hash table accordingly.
375 */
376 static inline void tun_flow_save_rps_rxhash(struct tun_flow_entry *e, u32 hash)
377 {
378 if (unlikely(e->rps_rxhash != hash)) {
379 sock_rps_reset_flow_hash(e->rps_rxhash);
380 e->rps_rxhash = hash;
381 }
382 }
383
384 /* We try to identify a flow through its rxhash first. The reason that
385 * we do not check rxq no. is because some cards(e.g 82599), chooses
386 * the rxq based on the txq where the last packet of the flow comes. As
387 * the userspace application move between processors, we may get a
388 * different rxq no. here. If we could not get rxhash, then we would
389 * hope the rxq no. may help here.
390 */
391 static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb,
392 void *accel_priv, select_queue_fallback_t fallback)
393 {
394 struct tun_struct *tun = netdev_priv(dev);
395 struct tun_flow_entry *e;
396 u32 txq = 0;
397 u32 numqueues = 0;
398
399 rcu_read_lock();
400 numqueues = ACCESS_ONCE(tun->numqueues);
401
402 txq = skb_get_hash(skb);
403 if (txq) {
404 e = tun_flow_find(&tun->flows[tun_hashfn(txq)], txq);
405 if (e) {
406 tun_flow_save_rps_rxhash(e, txq);
407 txq = e->queue_index;
408 } else
409 /* use multiply and shift instead of expensive divide */
410 txq = ((u64)txq * numqueues) >> 32;
411 } else if (likely(skb_rx_queue_recorded(skb))) {
412 txq = skb_get_rx_queue(skb);
413 while (unlikely(txq >= numqueues))
414 txq -= numqueues;
415 }
416
417 rcu_read_unlock();
418 return txq;
419 }
420
421 static inline bool tun_not_capable(struct tun_struct *tun)
422 {
423 const struct cred *cred = current_cred();
424 struct net *net = dev_net(tun->dev);
425
426 return ((uid_valid(tun->owner) && !uid_eq(cred->euid, tun->owner)) ||
427 (gid_valid(tun->group) && !in_egroup_p(tun->group))) &&
428 !ns_capable(net->user_ns, CAP_NET_ADMIN);
429 }
430
431 static void tun_set_real_num_queues(struct tun_struct *tun)
432 {
433 netif_set_real_num_tx_queues(tun->dev, tun->numqueues);
434 netif_set_real_num_rx_queues(tun->dev, tun->numqueues);
435 }
436
437 static void tun_disable_queue(struct tun_struct *tun, struct tun_file *tfile)
438 {
439 tfile->detached = tun;
440 list_add_tail(&tfile->next, &tun->disabled);
441 ++tun->numdisabled;
442 }
443
444 static struct tun_struct *tun_enable_queue(struct tun_file *tfile)
445 {
446 struct tun_struct *tun = tfile->detached;
447
448 tfile->detached = NULL;
449 list_del_init(&tfile->next);
450 --tun->numdisabled;
451 return tun;
452 }
453
454 static void tun_queue_purge(struct tun_file *tfile)
455 {
456 skb_queue_purge(&tfile->sk.sk_receive_queue);
457 skb_queue_purge(&tfile->sk.sk_error_queue);
458 }
459
460 static void __tun_detach(struct tun_file *tfile, bool clean)
461 {
462 struct tun_file *ntfile;
463 struct tun_struct *tun;
464
465 tun = rtnl_dereference(tfile->tun);
466
467 if (tun && !tfile->detached) {
468 u16 index = tfile->queue_index;
469 BUG_ON(index >= tun->numqueues);
470
471 rcu_assign_pointer(tun->tfiles[index],
472 tun->tfiles[tun->numqueues - 1]);
473 ntfile = rtnl_dereference(tun->tfiles[index]);
474 ntfile->queue_index = index;
475
476 --tun->numqueues;
477 if (clean) {
478 RCU_INIT_POINTER(tfile->tun, NULL);
479 sock_put(&tfile->sk);
480 } else
481 tun_disable_queue(tun, tfile);
482
483 synchronize_net();
484 tun_flow_delete_by_queue(tun, tun->numqueues + 1);
485 /* Drop read queue */
486 tun_queue_purge(tfile);
487 tun_set_real_num_queues(tun);
488 } else if (tfile->detached && clean) {
489 tun = tun_enable_queue(tfile);
490 sock_put(&tfile->sk);
491 }
492
493 if (clean) {
494 if (tun && tun->numqueues == 0 && tun->numdisabled == 0) {
495 netif_carrier_off(tun->dev);
496
497 if (!(tun->flags & IFF_PERSIST) &&
498 tun->dev->reg_state == NETREG_REGISTERED)
499 unregister_netdevice(tun->dev);
500 }
501
502 BUG_ON(!test_bit(SOCK_EXTERNALLY_ALLOCATED,
503 &tfile->socket.flags));
504 sk_release_kernel(&tfile->sk);
505 }
506 }
507
508 static void tun_detach(struct tun_file *tfile, bool clean)
509 {
510 rtnl_lock();
511 __tun_detach(tfile, clean);
512 rtnl_unlock();
513 }
514
515 static void tun_detach_all(struct net_device *dev)
516 {
517 struct tun_struct *tun = netdev_priv(dev);
518 struct tun_file *tfile, *tmp;
519 int i, n = tun->numqueues;
520
521 for (i = 0; i < n; i++) {
522 tfile = rtnl_dereference(tun->tfiles[i]);
523 BUG_ON(!tfile);
524 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
525 RCU_INIT_POINTER(tfile->tun, NULL);
526 --tun->numqueues;
527 }
528 list_for_each_entry(tfile, &tun->disabled, next) {
529 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
530 RCU_INIT_POINTER(tfile->tun, NULL);
531 }
532 BUG_ON(tun->numqueues != 0);
533
534 synchronize_net();
535 for (i = 0; i < n; i++) {
536 tfile = rtnl_dereference(tun->tfiles[i]);
537 /* Drop read queue */
538 tun_queue_purge(tfile);
539 sock_put(&tfile->sk);
540 }
541 list_for_each_entry_safe(tfile, tmp, &tun->disabled, next) {
542 tun_enable_queue(tfile);
543 tun_queue_purge(tfile);
544 sock_put(&tfile->sk);
545 }
546 BUG_ON(tun->numdisabled != 0);
547
548 if (tun->flags & IFF_PERSIST)
549 module_put(THIS_MODULE);
550 }
551
552 static int tun_attach(struct tun_struct *tun, struct file *file, bool skip_filter)
553 {
554 struct tun_file *tfile = file->private_data;
555 int err;
556
557 err = security_tun_dev_attach(tfile->socket.sk, tun->security);
558 if (err < 0)
559 goto out;
560
561 err = -EINVAL;
562 if (rtnl_dereference(tfile->tun) && !tfile->detached)
563 goto out;
564
565 err = -EBUSY;
566 if (!(tun->flags & IFF_MULTI_QUEUE) && tun->numqueues == 1)
567 goto out;
568
569 err = -E2BIG;
570 if (!tfile->detached &&
571 tun->numqueues + tun->numdisabled == MAX_TAP_QUEUES)
572 goto out;
573
574 err = 0;
575
576 /* Re-attach the filter to persist device */
577 if (!skip_filter && (tun->filter_attached == true)) {
578 err = sk_attach_filter(&tun->fprog, tfile->socket.sk);
579 if (!err)
580 goto out;
581 }
582 tfile->queue_index = tun->numqueues;
583 rcu_assign_pointer(tfile->tun, tun);
584 rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile);
585 tun->numqueues++;
586
587 if (tfile->detached)
588 tun_enable_queue(tfile);
589 else
590 sock_hold(&tfile->sk);
591
592 tun_set_real_num_queues(tun);
593
594 /* device is allowed to go away first, so no need to hold extra
595 * refcnt.
596 */
597
598 out:
599 return err;
600 }
601
602 static struct tun_struct *__tun_get(struct tun_file *tfile)
603 {
604 struct tun_struct *tun;
605
606 rcu_read_lock();
607 tun = rcu_dereference(tfile->tun);
608 if (tun)
609 dev_hold(tun->dev);
610 rcu_read_unlock();
611
612 return tun;
613 }
614
615 static struct tun_struct *tun_get(struct file *file)
616 {
617 return __tun_get(file->private_data);
618 }
619
620 static void tun_put(struct tun_struct *tun)
621 {
622 dev_put(tun->dev);
623 }
624
625 /* TAP filtering */
626 static void addr_hash_set(u32 *mask, const u8 *addr)
627 {
628 int n = ether_crc(ETH_ALEN, addr) >> 26;
629 mask[n >> 5] |= (1 << (n & 31));
630 }
631
632 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
633 {
634 int n = ether_crc(ETH_ALEN, addr) >> 26;
635 return mask[n >> 5] & (1 << (n & 31));
636 }
637
638 static int update_filter(struct tap_filter *filter, void __user *arg)
639 {
640 struct { u8 u[ETH_ALEN]; } *addr;
641 struct tun_filter uf;
642 int err, alen, n, nexact;
643
644 if (copy_from_user(&uf, arg, sizeof(uf)))
645 return -EFAULT;
646
647 if (!uf.count) {
648 /* Disabled */
649 filter->count = 0;
650 return 0;
651 }
652
653 alen = ETH_ALEN * uf.count;
654 addr = kmalloc(alen, GFP_KERNEL);
655 if (!addr)
656 return -ENOMEM;
657
658 if (copy_from_user(addr, arg + sizeof(uf), alen)) {
659 err = -EFAULT;
660 goto done;
661 }
662
663 /* The filter is updated without holding any locks. Which is
664 * perfectly safe. We disable it first and in the worst
665 * case we'll accept a few undesired packets. */
666 filter->count = 0;
667 wmb();
668
669 /* Use first set of addresses as an exact filter */
670 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
671 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
672
673 nexact = n;
674
675 /* Remaining multicast addresses are hashed,
676 * unicast will leave the filter disabled. */
677 memset(filter->mask, 0, sizeof(filter->mask));
678 for (; n < uf.count; n++) {
679 if (!is_multicast_ether_addr(addr[n].u)) {
680 err = 0; /* no filter */
681 goto done;
682 }
683 addr_hash_set(filter->mask, addr[n].u);
684 }
685
686 /* For ALLMULTI just set the mask to all ones.
687 * This overrides the mask populated above. */
688 if ((uf.flags & TUN_FLT_ALLMULTI))
689 memset(filter->mask, ~0, sizeof(filter->mask));
690
691 /* Now enable the filter */
692 wmb();
693 filter->count = nexact;
694
695 /* Return the number of exact filters */
696 err = nexact;
697
698 done:
699 kfree(addr);
700 return err;
701 }
702
703 /* Returns: 0 - drop, !=0 - accept */
704 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
705 {
706 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
707 * at this point. */
708 struct ethhdr *eh = (struct ethhdr *) skb->data;
709 int i;
710
711 /* Exact match */
712 for (i = 0; i < filter->count; i++)
713 if (ether_addr_equal(eh->h_dest, filter->addr[i]))
714 return 1;
715
716 /* Inexact match (multicast only) */
717 if (is_multicast_ether_addr(eh->h_dest))
718 return addr_hash_test(filter->mask, eh->h_dest);
719
720 return 0;
721 }
722
723 /*
724 * Checks whether the packet is accepted or not.
725 * Returns: 0 - drop, !=0 - accept
726 */
727 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
728 {
729 if (!filter->count)
730 return 1;
731
732 return run_filter(filter, skb);
733 }
734
735 /* Network device part of the driver */
736
737 static const struct ethtool_ops tun_ethtool_ops;
738
739 /* Net device detach from fd. */
740 static void tun_net_uninit(struct net_device *dev)
741 {
742 tun_detach_all(dev);
743 }
744
745 /* Net device open. */
746 static int tun_net_open(struct net_device *dev)
747 {
748 netif_tx_start_all_queues(dev);
749 return 0;
750 }
751
752 /* Net device close. */
753 static int tun_net_close(struct net_device *dev)
754 {
755 netif_tx_stop_all_queues(dev);
756 return 0;
757 }
758
759 /* Net device start xmit */
760 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
761 {
762 struct tun_struct *tun = netdev_priv(dev);
763 int txq = skb->queue_mapping;
764 struct tun_file *tfile;
765 u32 numqueues = 0;
766
767 rcu_read_lock();
768 tfile = rcu_dereference(tun->tfiles[txq]);
769 numqueues = ACCESS_ONCE(tun->numqueues);
770
771 /* Drop packet if interface is not attached */
772 if (txq >= numqueues)
773 goto drop;
774
775 if (numqueues == 1) {
776 /* Select queue was not called for the skbuff, so we extract the
777 * RPS hash and save it into the flow_table here.
778 */
779 __u32 rxhash;
780
781 rxhash = skb_get_hash(skb);
782 if (rxhash) {
783 struct tun_flow_entry *e;
784 e = tun_flow_find(&tun->flows[tun_hashfn(rxhash)],
785 rxhash);
786 if (e)
787 tun_flow_save_rps_rxhash(e, rxhash);
788 }
789 }
790
791 tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len);
792
793 BUG_ON(!tfile);
794
795 /* Drop if the filter does not like it.
796 * This is a noop if the filter is disabled.
797 * Filter can be enabled only for the TAP devices. */
798 if (!check_filter(&tun->txflt, skb))
799 goto drop;
800
801 if (tfile->socket.sk->sk_filter &&
802 sk_filter(tfile->socket.sk, skb))
803 goto drop;
804
805 /* Limit the number of packets queued by dividing txq length with the
806 * number of queues.
807 */
808 if (skb_queue_len(&tfile->socket.sk->sk_receive_queue) * numqueues
809 >= dev->tx_queue_len)
810 goto drop;
811
812 if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
813 goto drop;
814
815 if (skb->sk) {
816 sock_tx_timestamp(skb->sk, &skb_shinfo(skb)->tx_flags);
817 sw_tx_timestamp(skb);
818 }
819
820 /* Orphan the skb - required as we might hang on to it
821 * for indefinite time.
822 */
823 skb_orphan(skb);
824
825 nf_reset(skb);
826
827 /* Enqueue packet */
828 skb_queue_tail(&tfile->socket.sk->sk_receive_queue, skb);
829
830 /* Notify and wake up reader process */
831 if (tfile->flags & TUN_FASYNC)
832 kill_fasync(&tfile->fasync, SIGIO, POLL_IN);
833 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
834
835 rcu_read_unlock();
836 return NETDEV_TX_OK;
837
838 drop:
839 dev->stats.tx_dropped++;
840 skb_tx_error(skb);
841 kfree_skb(skb);
842 rcu_read_unlock();
843 return NET_XMIT_DROP;
844 }
845
846 static void tun_net_mclist(struct net_device *dev)
847 {
848 /*
849 * This callback is supposed to deal with mc filter in
850 * _rx_ path and has nothing to do with the _tx_ path.
851 * In rx path we always accept everything userspace gives us.
852 */
853 }
854
855 #define MIN_MTU 68
856 #define MAX_MTU 65535
857
858 static int
859 tun_net_change_mtu(struct net_device *dev, int new_mtu)
860 {
861 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
862 return -EINVAL;
863 dev->mtu = new_mtu;
864 return 0;
865 }
866
867 static netdev_features_t tun_net_fix_features(struct net_device *dev,
868 netdev_features_t features)
869 {
870 struct tun_struct *tun = netdev_priv(dev);
871
872 return (features & tun->set_features) | (features & ~TUN_USER_FEATURES);
873 }
874 #ifdef CONFIG_NET_POLL_CONTROLLER
875 static void tun_poll_controller(struct net_device *dev)
876 {
877 /*
878 * Tun only receives frames when:
879 * 1) the char device endpoint gets data from user space
880 * 2) the tun socket gets a sendmsg call from user space
881 * Since both of those are synchronous operations, we are guaranteed
882 * never to have pending data when we poll for it
883 * so there is nothing to do here but return.
884 * We need this though so netpoll recognizes us as an interface that
885 * supports polling, which enables bridge devices in virt setups to
886 * still use netconsole
887 */
888 return;
889 }
890 #endif
891 static const struct net_device_ops tun_netdev_ops = {
892 .ndo_uninit = tun_net_uninit,
893 .ndo_open = tun_net_open,
894 .ndo_stop = tun_net_close,
895 .ndo_start_xmit = tun_net_xmit,
896 .ndo_change_mtu = tun_net_change_mtu,
897 .ndo_fix_features = tun_net_fix_features,
898 .ndo_select_queue = tun_select_queue,
899 #ifdef CONFIG_NET_POLL_CONTROLLER
900 .ndo_poll_controller = tun_poll_controller,
901 #endif
902 };
903
904 static const struct net_device_ops tap_netdev_ops = {
905 .ndo_uninit = tun_net_uninit,
906 .ndo_open = tun_net_open,
907 .ndo_stop = tun_net_close,
908 .ndo_start_xmit = tun_net_xmit,
909 .ndo_change_mtu = tun_net_change_mtu,
910 .ndo_fix_features = tun_net_fix_features,
911 .ndo_set_rx_mode = tun_net_mclist,
912 .ndo_set_mac_address = eth_mac_addr,
913 .ndo_validate_addr = eth_validate_addr,
914 .ndo_select_queue = tun_select_queue,
915 #ifdef CONFIG_NET_POLL_CONTROLLER
916 .ndo_poll_controller = tun_poll_controller,
917 #endif
918 };
919
920 static void tun_flow_init(struct tun_struct *tun)
921 {
922 int i;
923
924 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++)
925 INIT_HLIST_HEAD(&tun->flows[i]);
926
927 tun->ageing_time = TUN_FLOW_EXPIRE;
928 setup_timer(&tun->flow_gc_timer, tun_flow_cleanup, (unsigned long)tun);
929 mod_timer(&tun->flow_gc_timer,
930 round_jiffies_up(jiffies + tun->ageing_time));
931 }
932
933 static void tun_flow_uninit(struct tun_struct *tun)
934 {
935 del_timer_sync(&tun->flow_gc_timer);
936 tun_flow_flush(tun);
937 }
938
939 /* Initialize net device. */
940 static void tun_net_init(struct net_device *dev)
941 {
942 struct tun_struct *tun = netdev_priv(dev);
943
944 switch (tun->flags & TUN_TYPE_MASK) {
945 case IFF_TUN:
946 dev->netdev_ops = &tun_netdev_ops;
947
948 /* Point-to-Point TUN Device */
949 dev->hard_header_len = 0;
950 dev->addr_len = 0;
951 dev->mtu = 1500;
952
953 /* Zero header length */
954 dev->type = ARPHRD_NONE;
955 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
956 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
957 break;
958
959 case IFF_TAP:
960 dev->netdev_ops = &tap_netdev_ops;
961 /* Ethernet TAP Device */
962 ether_setup(dev);
963 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
964 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
965
966 eth_hw_addr_random(dev);
967
968 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
969 break;
970 }
971 }
972
973 /* Character device part */
974
975 /* Poll */
976 static unsigned int tun_chr_poll(struct file *file, poll_table *wait)
977 {
978 struct tun_file *tfile = file->private_data;
979 struct tun_struct *tun = __tun_get(tfile);
980 struct sock *sk;
981 unsigned int mask = 0;
982
983 if (!tun)
984 return POLLERR;
985
986 sk = tfile->socket.sk;
987
988 tun_debug(KERN_INFO, tun, "tun_chr_poll\n");
989
990 poll_wait(file, sk_sleep(sk), wait);
991
992 if (!skb_queue_empty(&sk->sk_receive_queue))
993 mask |= POLLIN | POLLRDNORM;
994
995 if (sock_writeable(sk) ||
996 (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
997 sock_writeable(sk)))
998 mask |= POLLOUT | POLLWRNORM;
999
1000 if (tun->dev->reg_state != NETREG_REGISTERED)
1001 mask = POLLERR;
1002
1003 tun_put(tun);
1004 return mask;
1005 }
1006
1007 /* prepad is the amount to reserve at front. len is length after that.
1008 * linear is a hint as to how much to copy (usually headers). */
1009 static struct sk_buff *tun_alloc_skb(struct tun_file *tfile,
1010 size_t prepad, size_t len,
1011 size_t linear, int noblock)
1012 {
1013 struct sock *sk = tfile->socket.sk;
1014 struct sk_buff *skb;
1015 int err;
1016
1017 /* Under a page? Don't bother with paged skb. */
1018 if (prepad + len < PAGE_SIZE || !linear)
1019 linear = len;
1020
1021 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
1022 &err, 0);
1023 if (!skb)
1024 return ERR_PTR(err);
1025
1026 skb_reserve(skb, prepad);
1027 skb_put(skb, linear);
1028 skb->data_len = len - linear;
1029 skb->len += len - linear;
1030
1031 return skb;
1032 }
1033
1034 /* Get packet from user space buffer */
1035 static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
1036 void *msg_control, struct iov_iter *from,
1037 int noblock)
1038 {
1039 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
1040 struct sk_buff *skb;
1041 size_t total_len = iov_iter_count(from);
1042 size_t len = total_len, align = NET_SKB_PAD, linear;
1043 struct virtio_net_hdr gso = { 0 };
1044 int good_linear;
1045 int copylen;
1046 bool zerocopy = false;
1047 int err;
1048 u32 rxhash;
1049 ssize_t n;
1050
1051 if (!(tun->flags & IFF_NO_PI)) {
1052 if (len < sizeof(pi))
1053 return -EINVAL;
1054 len -= sizeof(pi);
1055
1056 n = copy_from_iter(&pi, sizeof(pi), from);
1057 if (n != sizeof(pi))
1058 return -EFAULT;
1059 }
1060
1061 if (tun->flags & IFF_VNET_HDR) {
1062 if (len < tun->vnet_hdr_sz)
1063 return -EINVAL;
1064 len -= tun->vnet_hdr_sz;
1065
1066 n = copy_from_iter(&gso, sizeof(gso), from);
1067 if (n != sizeof(gso))
1068 return -EFAULT;
1069
1070 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
1071 tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2 > tun16_to_cpu(tun, gso.hdr_len))
1072 gso.hdr_len = cpu_to_tun16(tun, tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2);
1073
1074 if (tun16_to_cpu(tun, gso.hdr_len) > len)
1075 return -EINVAL;
1076 iov_iter_advance(from, tun->vnet_hdr_sz - sizeof(gso));
1077 }
1078
1079 if ((tun->flags & TUN_TYPE_MASK) == IFF_TAP) {
1080 align += NET_IP_ALIGN;
1081 if (unlikely(len < ETH_HLEN ||
1082 (gso.hdr_len && tun16_to_cpu(tun, gso.hdr_len) < ETH_HLEN)))
1083 return -EINVAL;
1084 }
1085
1086 good_linear = SKB_MAX_HEAD(align);
1087
1088 if (msg_control) {
1089 struct iov_iter i = *from;
1090
1091 /* There are 256 bytes to be copied in skb, so there is
1092 * enough room for skb expand head in case it is used.
1093 * The rest of the buffer is mapped from userspace.
1094 */
1095 copylen = gso.hdr_len ? tun16_to_cpu(tun, gso.hdr_len) : GOODCOPY_LEN;
1096 if (copylen > good_linear)
1097 copylen = good_linear;
1098 linear = copylen;
1099 iov_iter_advance(&i, copylen);
1100 if (iov_iter_npages(&i, INT_MAX) <= MAX_SKB_FRAGS)
1101 zerocopy = true;
1102 }
1103
1104 if (!zerocopy) {
1105 copylen = len;
1106 if (tun16_to_cpu(tun, gso.hdr_len) > good_linear)
1107 linear = good_linear;
1108 else
1109 linear = tun16_to_cpu(tun, gso.hdr_len);
1110 }
1111
1112 skb = tun_alloc_skb(tfile, align, copylen, linear, noblock);
1113 if (IS_ERR(skb)) {
1114 if (PTR_ERR(skb) != -EAGAIN)
1115 tun->dev->stats.rx_dropped++;
1116 return PTR_ERR(skb);
1117 }
1118
1119 if (zerocopy)
1120 err = zerocopy_sg_from_iter(skb, from);
1121 else {
1122 err = skb_copy_datagram_from_iter(skb, 0, from, len);
1123 if (!err && msg_control) {
1124 struct ubuf_info *uarg = msg_control;
1125 uarg->callback(uarg, false);
1126 }
1127 }
1128
1129 if (err) {
1130 tun->dev->stats.rx_dropped++;
1131 kfree_skb(skb);
1132 return -EFAULT;
1133 }
1134
1135 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
1136 if (!skb_partial_csum_set(skb, tun16_to_cpu(tun, gso.csum_start),
1137 tun16_to_cpu(tun, gso.csum_offset))) {
1138 tun->dev->stats.rx_frame_errors++;
1139 kfree_skb(skb);
1140 return -EINVAL;
1141 }
1142 }
1143
1144 switch (tun->flags & TUN_TYPE_MASK) {
1145 case IFF_TUN:
1146 if (tun->flags & IFF_NO_PI) {
1147 switch (skb->data[0] & 0xf0) {
1148 case 0x40:
1149 pi.proto = htons(ETH_P_IP);
1150 break;
1151 case 0x60:
1152 pi.proto = htons(ETH_P_IPV6);
1153 break;
1154 default:
1155 tun->dev->stats.rx_dropped++;
1156 kfree_skb(skb);
1157 return -EINVAL;
1158 }
1159 }
1160
1161 skb_reset_mac_header(skb);
1162 skb->protocol = pi.proto;
1163 skb->dev = tun->dev;
1164 break;
1165 case IFF_TAP:
1166 skb->protocol = eth_type_trans(skb, tun->dev);
1167 break;
1168 }
1169
1170 skb_reset_network_header(skb);
1171
1172 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
1173 pr_debug("GSO!\n");
1174 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
1175 case VIRTIO_NET_HDR_GSO_TCPV4:
1176 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
1177 break;
1178 case VIRTIO_NET_HDR_GSO_TCPV6:
1179 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
1180 break;
1181 case VIRTIO_NET_HDR_GSO_UDP:
1182 {
1183 static bool warned;
1184
1185 if (!warned) {
1186 warned = true;
1187 netdev_warn(tun->dev,
1188 "%s: using disabled UFO feature; please fix this program\n",
1189 current->comm);
1190 }
1191 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
1192 if (skb->protocol == htons(ETH_P_IPV6))
1193 ipv6_proxy_select_ident(skb);
1194 break;
1195 }
1196 default:
1197 tun->dev->stats.rx_frame_errors++;
1198 kfree_skb(skb);
1199 return -EINVAL;
1200 }
1201
1202 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
1203 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
1204
1205 skb_shinfo(skb)->gso_size = tun16_to_cpu(tun, gso.gso_size);
1206 if (skb_shinfo(skb)->gso_size == 0) {
1207 tun->dev->stats.rx_frame_errors++;
1208 kfree_skb(skb);
1209 return -EINVAL;
1210 }
1211
1212 /* Header must be checked, and gso_segs computed. */
1213 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
1214 skb_shinfo(skb)->gso_segs = 0;
1215 }
1216
1217 /* copy skb_ubuf_info for callback when skb has no error */
1218 if (zerocopy) {
1219 skb_shinfo(skb)->destructor_arg = msg_control;
1220 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1221 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
1222 }
1223
1224 skb_probe_transport_header(skb, 0);
1225
1226 rxhash = skb_get_hash(skb);
1227 netif_rx_ni(skb);
1228
1229 tun->dev->stats.rx_packets++;
1230 tun->dev->stats.rx_bytes += len;
1231
1232 tun_flow_update(tun, rxhash, tfile);
1233 return total_len;
1234 }
1235
1236 static ssize_t tun_chr_write_iter(struct kiocb *iocb, struct iov_iter *from)
1237 {
1238 struct file *file = iocb->ki_filp;
1239 struct tun_struct *tun = tun_get(file);
1240 struct tun_file *tfile = file->private_data;
1241 ssize_t result;
1242
1243 if (!tun)
1244 return -EBADFD;
1245
1246 result = tun_get_user(tun, tfile, NULL, from, file->f_flags & O_NONBLOCK);
1247
1248 tun_put(tun);
1249 return result;
1250 }
1251
1252 /* Put packet to the user space buffer */
1253 static ssize_t tun_put_user(struct tun_struct *tun,
1254 struct tun_file *tfile,
1255 struct sk_buff *skb,
1256 struct iov_iter *iter)
1257 {
1258 struct tun_pi pi = { 0, skb->protocol };
1259 ssize_t total;
1260 int vlan_offset = 0;
1261 int vlan_hlen = 0;
1262 int vnet_hdr_sz = 0;
1263
1264 if (vlan_tx_tag_present(skb))
1265 vlan_hlen = VLAN_HLEN;
1266
1267 if (tun->flags & IFF_VNET_HDR)
1268 vnet_hdr_sz = tun->vnet_hdr_sz;
1269
1270 total = skb->len + vlan_hlen + vnet_hdr_sz;
1271
1272 if (!(tun->flags & IFF_NO_PI)) {
1273 if (iov_iter_count(iter) < sizeof(pi))
1274 return -EINVAL;
1275
1276 total += sizeof(pi);
1277 if (iov_iter_count(iter) < total) {
1278 /* Packet will be striped */
1279 pi.flags |= TUN_PKT_STRIP;
1280 }
1281
1282 if (copy_to_iter(&pi, sizeof(pi), iter) != sizeof(pi))
1283 return -EFAULT;
1284 }
1285
1286 if (vnet_hdr_sz) {
1287 struct virtio_net_hdr gso = { 0 }; /* no info leak */
1288 if (iov_iter_count(iter) < vnet_hdr_sz)
1289 return -EINVAL;
1290
1291 if (skb_is_gso(skb)) {
1292 struct skb_shared_info *sinfo = skb_shinfo(skb);
1293
1294 /* This is a hint as to how much should be linear. */
1295 gso.hdr_len = cpu_to_tun16(tun, skb_headlen(skb));
1296 gso.gso_size = cpu_to_tun16(tun, sinfo->gso_size);
1297 if (sinfo->gso_type & SKB_GSO_TCPV4)
1298 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
1299 else if (sinfo->gso_type & SKB_GSO_TCPV6)
1300 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
1301 else {
1302 pr_err("unexpected GSO type: "
1303 "0x%x, gso_size %d, hdr_len %d\n",
1304 sinfo->gso_type, tun16_to_cpu(tun, gso.gso_size),
1305 tun16_to_cpu(tun, gso.hdr_len));
1306 print_hex_dump(KERN_ERR, "tun: ",
1307 DUMP_PREFIX_NONE,
1308 16, 1, skb->head,
1309 min((int)tun16_to_cpu(tun, gso.hdr_len), 64), true);
1310 WARN_ON_ONCE(1);
1311 return -EINVAL;
1312 }
1313 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
1314 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
1315 } else
1316 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
1317
1318 if (skb->ip_summed == CHECKSUM_PARTIAL) {
1319 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
1320 gso.csum_start = cpu_to_tun16(tun, skb_checksum_start_offset(skb) +
1321 vlan_hlen);
1322 gso.csum_offset = cpu_to_tun16(tun, skb->csum_offset);
1323 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
1324 gso.flags = VIRTIO_NET_HDR_F_DATA_VALID;
1325 } /* else everything is zero */
1326
1327 if (copy_to_iter(&gso, sizeof(gso), iter) != sizeof(gso))
1328 return -EFAULT;
1329
1330 iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso));
1331 }
1332
1333 if (vlan_hlen) {
1334 int ret;
1335 struct {
1336 __be16 h_vlan_proto;
1337 __be16 h_vlan_TCI;
1338 } veth;
1339
1340 veth.h_vlan_proto = skb->vlan_proto;
1341 veth.h_vlan_TCI = htons(vlan_tx_tag_get(skb));
1342
1343 vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);
1344
1345 ret = skb_copy_datagram_iter(skb, 0, iter, vlan_offset);
1346 if (ret || !iov_iter_count(iter))
1347 goto done;
1348
1349 ret = copy_to_iter(&veth, sizeof(veth), iter);
1350 if (ret != sizeof(veth) || !iov_iter_count(iter))
1351 goto done;
1352 }
1353
1354 skb_copy_datagram_iter(skb, vlan_offset, iter, skb->len - vlan_offset);
1355
1356 done:
1357 tun->dev->stats.tx_packets++;
1358 tun->dev->stats.tx_bytes += skb->len + vlan_hlen;
1359
1360 return total;
1361 }
1362
1363 static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
1364 struct iov_iter *to,
1365 int noblock)
1366 {
1367 struct sk_buff *skb;
1368 ssize_t ret;
1369 int peeked, err, off = 0;
1370
1371 tun_debug(KERN_INFO, tun, "tun_do_read\n");
1372
1373 if (!iov_iter_count(to))
1374 return 0;
1375
1376 if (tun->dev->reg_state != NETREG_REGISTERED)
1377 return -EIO;
1378
1379 /* Read frames from queue */
1380 skb = __skb_recv_datagram(tfile->socket.sk, noblock ? MSG_DONTWAIT : 0,
1381 &peeked, &off, &err);
1382 if (!skb)
1383 return 0;
1384
1385 ret = tun_put_user(tun, tfile, skb, to);
1386 if (unlikely(ret < 0))
1387 kfree_skb(skb);
1388 else
1389 consume_skb(skb);
1390
1391 return ret;
1392 }
1393
1394 static ssize_t tun_chr_read_iter(struct kiocb *iocb, struct iov_iter *to)
1395 {
1396 struct file *file = iocb->ki_filp;
1397 struct tun_file *tfile = file->private_data;
1398 struct tun_struct *tun = __tun_get(tfile);
1399 ssize_t len = iov_iter_count(to), ret;
1400
1401 if (!tun)
1402 return -EBADFD;
1403 ret = tun_do_read(tun, tfile, to, file->f_flags & O_NONBLOCK);
1404 ret = min_t(ssize_t, ret, len);
1405 if (ret > 0)
1406 iocb->ki_pos = ret;
1407 tun_put(tun);
1408 return ret;
1409 }
1410
1411 static void tun_free_netdev(struct net_device *dev)
1412 {
1413 struct tun_struct *tun = netdev_priv(dev);
1414
1415 BUG_ON(!(list_empty(&tun->disabled)));
1416 tun_flow_uninit(tun);
1417 security_tun_dev_free_security(tun->security);
1418 free_netdev(dev);
1419 }
1420
1421 static void tun_setup(struct net_device *dev)
1422 {
1423 struct tun_struct *tun = netdev_priv(dev);
1424
1425 tun->owner = INVALID_UID;
1426 tun->group = INVALID_GID;
1427
1428 dev->ethtool_ops = &tun_ethtool_ops;
1429 dev->destructor = tun_free_netdev;
1430 }
1431
1432 /* Trivial set of netlink ops to allow deleting tun or tap
1433 * device with netlink.
1434 */
1435 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
1436 {
1437 return -EINVAL;
1438 }
1439
1440 static struct rtnl_link_ops tun_link_ops __read_mostly = {
1441 .kind = DRV_NAME,
1442 .priv_size = sizeof(struct tun_struct),
1443 .setup = tun_setup,
1444 .validate = tun_validate,
1445 };
1446
1447 static void tun_sock_write_space(struct sock *sk)
1448 {
1449 struct tun_file *tfile;
1450 wait_queue_head_t *wqueue;
1451
1452 if (!sock_writeable(sk))
1453 return;
1454
1455 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
1456 return;
1457
1458 wqueue = sk_sleep(sk);
1459 if (wqueue && waitqueue_active(wqueue))
1460 wake_up_interruptible_sync_poll(wqueue, POLLOUT |
1461 POLLWRNORM | POLLWRBAND);
1462
1463 tfile = container_of(sk, struct tun_file, sk);
1464 kill_fasync(&tfile->fasync, SIGIO, POLL_OUT);
1465 }
1466
1467 static int tun_sendmsg(struct kiocb *iocb, struct socket *sock,
1468 struct msghdr *m, size_t total_len)
1469 {
1470 int ret;
1471 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1472 struct tun_struct *tun = __tun_get(tfile);
1473
1474 if (!tun)
1475 return -EBADFD;
1476
1477 ret = tun_get_user(tun, tfile, m->msg_control, &m->msg_iter,
1478 m->msg_flags & MSG_DONTWAIT);
1479 tun_put(tun);
1480 return ret;
1481 }
1482
1483 static int tun_recvmsg(struct kiocb *iocb, struct socket *sock,
1484 struct msghdr *m, size_t total_len,
1485 int flags)
1486 {
1487 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1488 struct tun_struct *tun = __tun_get(tfile);
1489 int ret;
1490
1491 if (!tun)
1492 return -EBADFD;
1493
1494 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC|MSG_ERRQUEUE)) {
1495 ret = -EINVAL;
1496 goto out;
1497 }
1498 if (flags & MSG_ERRQUEUE) {
1499 ret = sock_recv_errqueue(sock->sk, m, total_len,
1500 SOL_PACKET, TUN_TX_TIMESTAMP);
1501 goto out;
1502 }
1503 ret = tun_do_read(tun, tfile, &m->msg_iter, flags & MSG_DONTWAIT);
1504 if (ret > total_len) {
1505 m->msg_flags |= MSG_TRUNC;
1506 ret = flags & MSG_TRUNC ? ret : total_len;
1507 }
1508 out:
1509 tun_put(tun);
1510 return ret;
1511 }
1512
1513 static int tun_release(struct socket *sock)
1514 {
1515 if (sock->sk)
1516 sock_put(sock->sk);
1517 return 0;
1518 }
1519
1520 /* Ops structure to mimic raw sockets with tun */
1521 static const struct proto_ops tun_socket_ops = {
1522 .sendmsg = tun_sendmsg,
1523 .recvmsg = tun_recvmsg,
1524 .release = tun_release,
1525 };
1526
1527 static struct proto tun_proto = {
1528 .name = "tun",
1529 .owner = THIS_MODULE,
1530 .obj_size = sizeof(struct tun_file),
1531 };
1532
1533 static int tun_flags(struct tun_struct *tun)
1534 {
1535 return tun->flags & (TUN_FEATURES | IFF_PERSIST | IFF_TUN | IFF_TAP);
1536 }
1537
1538 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
1539 char *buf)
1540 {
1541 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1542 return sprintf(buf, "0x%x\n", tun_flags(tun));
1543 }
1544
1545 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
1546 char *buf)
1547 {
1548 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1549 return uid_valid(tun->owner)?
1550 sprintf(buf, "%u\n",
1551 from_kuid_munged(current_user_ns(), tun->owner)):
1552 sprintf(buf, "-1\n");
1553 }
1554
1555 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
1556 char *buf)
1557 {
1558 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1559 return gid_valid(tun->group) ?
1560 sprintf(buf, "%u\n",
1561 from_kgid_munged(current_user_ns(), tun->group)):
1562 sprintf(buf, "-1\n");
1563 }
1564
1565 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
1566 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
1567 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
1568
1569 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
1570 {
1571 struct tun_struct *tun;
1572 struct tun_file *tfile = file->private_data;
1573 struct net_device *dev;
1574 int err;
1575
1576 if (tfile->detached)
1577 return -EINVAL;
1578
1579 dev = __dev_get_by_name(net, ifr->ifr_name);
1580 if (dev) {
1581 if (ifr->ifr_flags & IFF_TUN_EXCL)
1582 return -EBUSY;
1583 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
1584 tun = netdev_priv(dev);
1585 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
1586 tun = netdev_priv(dev);
1587 else
1588 return -EINVAL;
1589
1590 if (!!(ifr->ifr_flags & IFF_MULTI_QUEUE) !=
1591 !!(tun->flags & IFF_MULTI_QUEUE))
1592 return -EINVAL;
1593
1594 if (tun_not_capable(tun))
1595 return -EPERM;
1596 err = security_tun_dev_open(tun->security);
1597 if (err < 0)
1598 return err;
1599
1600 err = tun_attach(tun, file, ifr->ifr_flags & IFF_NOFILTER);
1601 if (err < 0)
1602 return err;
1603
1604 if (tun->flags & IFF_MULTI_QUEUE &&
1605 (tun->numqueues + tun->numdisabled > 1)) {
1606 /* One or more queue has already been attached, no need
1607 * to initialize the device again.
1608 */
1609 return 0;
1610 }
1611 }
1612 else {
1613 char *name;
1614 unsigned long flags = 0;
1615 int queues = ifr->ifr_flags & IFF_MULTI_QUEUE ?
1616 MAX_TAP_QUEUES : 1;
1617
1618 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1619 return -EPERM;
1620 err = security_tun_dev_create();
1621 if (err < 0)
1622 return err;
1623
1624 /* Set dev type */
1625 if (ifr->ifr_flags & IFF_TUN) {
1626 /* TUN device */
1627 flags |= IFF_TUN;
1628 name = "tun%d";
1629 } else if (ifr->ifr_flags & IFF_TAP) {
1630 /* TAP device */
1631 flags |= IFF_TAP;
1632 name = "tap%d";
1633 } else
1634 return -EINVAL;
1635
1636 if (*ifr->ifr_name)
1637 name = ifr->ifr_name;
1638
1639 dev = alloc_netdev_mqs(sizeof(struct tun_struct), name,
1640 NET_NAME_UNKNOWN, tun_setup, queues,
1641 queues);
1642
1643 if (!dev)
1644 return -ENOMEM;
1645
1646 dev_net_set(dev, net);
1647 dev->rtnl_link_ops = &tun_link_ops;
1648 dev->ifindex = tfile->ifindex;
1649
1650 tun = netdev_priv(dev);
1651 tun->dev = dev;
1652 tun->flags = flags;
1653 tun->txflt.count = 0;
1654 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
1655
1656 tun->filter_attached = false;
1657 tun->sndbuf = tfile->socket.sk->sk_sndbuf;
1658
1659 spin_lock_init(&tun->lock);
1660
1661 err = security_tun_dev_alloc_security(&tun->security);
1662 if (err < 0)
1663 goto err_free_dev;
1664
1665 tun_net_init(dev);
1666 tun_flow_init(tun);
1667
1668 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
1669 TUN_USER_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
1670 NETIF_F_HW_VLAN_STAG_TX;
1671 dev->features = dev->hw_features;
1672 dev->vlan_features = dev->features &
1673 ~(NETIF_F_HW_VLAN_CTAG_TX |
1674 NETIF_F_HW_VLAN_STAG_TX);
1675
1676 INIT_LIST_HEAD(&tun->disabled);
1677 err = tun_attach(tun, file, false);
1678 if (err < 0)
1679 goto err_free_flow;
1680
1681 err = register_netdevice(tun->dev);
1682 if (err < 0)
1683 goto err_detach;
1684
1685 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
1686 device_create_file(&tun->dev->dev, &dev_attr_owner) ||
1687 device_create_file(&tun->dev->dev, &dev_attr_group))
1688 pr_err("Failed to create tun sysfs files\n");
1689 }
1690
1691 netif_carrier_on(tun->dev);
1692
1693 tun_debug(KERN_INFO, tun, "tun_set_iff\n");
1694
1695 tun->flags = (tun->flags & ~TUN_FEATURES) |
1696 (ifr->ifr_flags & TUN_FEATURES);
1697
1698 /* Make sure persistent devices do not get stuck in
1699 * xoff state.
1700 */
1701 if (netif_running(tun->dev))
1702 netif_tx_wake_all_queues(tun->dev);
1703
1704 strcpy(ifr->ifr_name, tun->dev->name);
1705 return 0;
1706
1707 err_detach:
1708 tun_detach_all(dev);
1709 err_free_flow:
1710 tun_flow_uninit(tun);
1711 security_tun_dev_free_security(tun->security);
1712 err_free_dev:
1713 free_netdev(dev);
1714 return err;
1715 }
1716
1717 static void tun_get_iff(struct net *net, struct tun_struct *tun,
1718 struct ifreq *ifr)
1719 {
1720 tun_debug(KERN_INFO, tun, "tun_get_iff\n");
1721
1722 strcpy(ifr->ifr_name, tun->dev->name);
1723
1724 ifr->ifr_flags = tun_flags(tun);
1725
1726 }
1727
1728 /* This is like a cut-down ethtool ops, except done via tun fd so no
1729 * privs required. */
1730 static int set_offload(struct tun_struct *tun, unsigned long arg)
1731 {
1732 netdev_features_t features = 0;
1733
1734 if (arg & TUN_F_CSUM) {
1735 features |= NETIF_F_HW_CSUM;
1736 arg &= ~TUN_F_CSUM;
1737
1738 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1739 if (arg & TUN_F_TSO_ECN) {
1740 features |= NETIF_F_TSO_ECN;
1741 arg &= ~TUN_F_TSO_ECN;
1742 }
1743 if (arg & TUN_F_TSO4)
1744 features |= NETIF_F_TSO;
1745 if (arg & TUN_F_TSO6)
1746 features |= NETIF_F_TSO6;
1747 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1748 }
1749 }
1750
1751 /* This gives the user a way to test for new features in future by
1752 * trying to set them. */
1753 if (arg)
1754 return -EINVAL;
1755
1756 tun->set_features = features;
1757 netdev_update_features(tun->dev);
1758
1759 return 0;
1760 }
1761
1762 static void tun_detach_filter(struct tun_struct *tun, int n)
1763 {
1764 int i;
1765 struct tun_file *tfile;
1766
1767 for (i = 0; i < n; i++) {
1768 tfile = rtnl_dereference(tun->tfiles[i]);
1769 sk_detach_filter(tfile->socket.sk);
1770 }
1771
1772 tun->filter_attached = false;
1773 }
1774
1775 static int tun_attach_filter(struct tun_struct *tun)
1776 {
1777 int i, ret = 0;
1778 struct tun_file *tfile;
1779
1780 for (i = 0; i < tun->numqueues; i++) {
1781 tfile = rtnl_dereference(tun->tfiles[i]);
1782 ret = sk_attach_filter(&tun->fprog, tfile->socket.sk);
1783 if (ret) {
1784 tun_detach_filter(tun, i);
1785 return ret;
1786 }
1787 }
1788
1789 tun->filter_attached = true;
1790 return ret;
1791 }
1792
1793 static void tun_set_sndbuf(struct tun_struct *tun)
1794 {
1795 struct tun_file *tfile;
1796 int i;
1797
1798 for (i = 0; i < tun->numqueues; i++) {
1799 tfile = rtnl_dereference(tun->tfiles[i]);
1800 tfile->socket.sk->sk_sndbuf = tun->sndbuf;
1801 }
1802 }
1803
1804 static int tun_set_queue(struct file *file, struct ifreq *ifr)
1805 {
1806 struct tun_file *tfile = file->private_data;
1807 struct tun_struct *tun;
1808 int ret = 0;
1809
1810 rtnl_lock();
1811
1812 if (ifr->ifr_flags & IFF_ATTACH_QUEUE) {
1813 tun = tfile->detached;
1814 if (!tun) {
1815 ret = -EINVAL;
1816 goto unlock;
1817 }
1818 ret = security_tun_dev_attach_queue(tun->security);
1819 if (ret < 0)
1820 goto unlock;
1821 ret = tun_attach(tun, file, false);
1822 } else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
1823 tun = rtnl_dereference(tfile->tun);
1824 if (!tun || !(tun->flags & IFF_MULTI_QUEUE) || tfile->detached)
1825 ret = -EINVAL;
1826 else
1827 __tun_detach(tfile, false);
1828 } else
1829 ret = -EINVAL;
1830
1831 unlock:
1832 rtnl_unlock();
1833 return ret;
1834 }
1835
1836 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
1837 unsigned long arg, int ifreq_len)
1838 {
1839 struct tun_file *tfile = file->private_data;
1840 struct tun_struct *tun;
1841 void __user* argp = (void __user*)arg;
1842 struct ifreq ifr;
1843 kuid_t owner;
1844 kgid_t group;
1845 int sndbuf;
1846 int vnet_hdr_sz;
1847 unsigned int ifindex;
1848 int le;
1849 int ret;
1850
1851 if (cmd == TUNSETIFF || cmd == TUNSETQUEUE || _IOC_TYPE(cmd) == 0x89) {
1852 if (copy_from_user(&ifr, argp, ifreq_len))
1853 return -EFAULT;
1854 } else {
1855 memset(&ifr, 0, sizeof(ifr));
1856 }
1857 if (cmd == TUNGETFEATURES) {
1858 /* Currently this just means: "what IFF flags are valid?".
1859 * This is needed because we never checked for invalid flags on
1860 * TUNSETIFF.
1861 */
1862 return put_user(IFF_TUN | IFF_TAP | TUN_FEATURES,
1863 (unsigned int __user*)argp);
1864 } else if (cmd == TUNSETQUEUE)
1865 return tun_set_queue(file, &ifr);
1866
1867 ret = 0;
1868 rtnl_lock();
1869
1870 tun = __tun_get(tfile);
1871 if (cmd == TUNSETIFF && !tun) {
1872 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1873
1874 ret = tun_set_iff(tfile->net, file, &ifr);
1875
1876 if (ret)
1877 goto unlock;
1878
1879 if (copy_to_user(argp, &ifr, ifreq_len))
1880 ret = -EFAULT;
1881 goto unlock;
1882 }
1883 if (cmd == TUNSETIFINDEX) {
1884 ret = -EPERM;
1885 if (tun)
1886 goto unlock;
1887
1888 ret = -EFAULT;
1889 if (copy_from_user(&ifindex, argp, sizeof(ifindex)))
1890 goto unlock;
1891
1892 ret = 0;
1893 tfile->ifindex = ifindex;
1894 goto unlock;
1895 }
1896
1897 ret = -EBADFD;
1898 if (!tun)
1899 goto unlock;
1900
1901 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %u\n", cmd);
1902
1903 ret = 0;
1904 switch (cmd) {
1905 case TUNGETIFF:
1906 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1907
1908 if (tfile->detached)
1909 ifr.ifr_flags |= IFF_DETACH_QUEUE;
1910 if (!tfile->socket.sk->sk_filter)
1911 ifr.ifr_flags |= IFF_NOFILTER;
1912
1913 if (copy_to_user(argp, &ifr, ifreq_len))
1914 ret = -EFAULT;
1915 break;
1916
1917 case TUNSETNOCSUM:
1918 /* Disable/Enable checksum */
1919
1920 /* [unimplemented] */
1921 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n",
1922 arg ? "disabled" : "enabled");
1923 break;
1924
1925 case TUNSETPERSIST:
1926 /* Disable/Enable persist mode. Keep an extra reference to the
1927 * module to prevent the module being unprobed.
1928 */
1929 if (arg && !(tun->flags & IFF_PERSIST)) {
1930 tun->flags |= IFF_PERSIST;
1931 __module_get(THIS_MODULE);
1932 }
1933 if (!arg && (tun->flags & IFF_PERSIST)) {
1934 tun->flags &= ~IFF_PERSIST;
1935 module_put(THIS_MODULE);
1936 }
1937
1938 tun_debug(KERN_INFO, tun, "persist %s\n",
1939 arg ? "enabled" : "disabled");
1940 break;
1941
1942 case TUNSETOWNER:
1943 /* Set owner of the device */
1944 owner = make_kuid(current_user_ns(), arg);
1945 if (!uid_valid(owner)) {
1946 ret = -EINVAL;
1947 break;
1948 }
1949 tun->owner = owner;
1950 tun_debug(KERN_INFO, tun, "owner set to %u\n",
1951 from_kuid(&init_user_ns, tun->owner));
1952 break;
1953
1954 case TUNSETGROUP:
1955 /* Set group of the device */
1956 group = make_kgid(current_user_ns(), arg);
1957 if (!gid_valid(group)) {
1958 ret = -EINVAL;
1959 break;
1960 }
1961 tun->group = group;
1962 tun_debug(KERN_INFO, tun, "group set to %u\n",
1963 from_kgid(&init_user_ns, tun->group));
1964 break;
1965
1966 case TUNSETLINK:
1967 /* Only allow setting the type when the interface is down */
1968 if (tun->dev->flags & IFF_UP) {
1969 tun_debug(KERN_INFO, tun,
1970 "Linktype set failed because interface is up\n");
1971 ret = -EBUSY;
1972 } else {
1973 tun->dev->type = (int) arg;
1974 tun_debug(KERN_INFO, tun, "linktype set to %d\n",
1975 tun->dev->type);
1976 ret = 0;
1977 }
1978 break;
1979
1980 #ifdef TUN_DEBUG
1981 case TUNSETDEBUG:
1982 tun->debug = arg;
1983 break;
1984 #endif
1985 case TUNSETOFFLOAD:
1986 ret = set_offload(tun, arg);
1987 break;
1988
1989 case TUNSETTXFILTER:
1990 /* Can be set only for TAPs */
1991 ret = -EINVAL;
1992 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
1993 break;
1994 ret = update_filter(&tun->txflt, (void __user *)arg);
1995 break;
1996
1997 case SIOCGIFHWADDR:
1998 /* Get hw address */
1999 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
2000 ifr.ifr_hwaddr.sa_family = tun->dev->type;
2001 if (copy_to_user(argp, &ifr, ifreq_len))
2002 ret = -EFAULT;
2003 break;
2004
2005 case SIOCSIFHWADDR:
2006 /* Set hw address */
2007 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
2008 ifr.ifr_hwaddr.sa_data);
2009
2010 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
2011 break;
2012
2013 case TUNGETSNDBUF:
2014 sndbuf = tfile->socket.sk->sk_sndbuf;
2015 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
2016 ret = -EFAULT;
2017 break;
2018
2019 case TUNSETSNDBUF:
2020 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
2021 ret = -EFAULT;
2022 break;
2023 }
2024
2025 tun->sndbuf = sndbuf;
2026 tun_set_sndbuf(tun);
2027 break;
2028
2029 case TUNGETVNETHDRSZ:
2030 vnet_hdr_sz = tun->vnet_hdr_sz;
2031 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
2032 ret = -EFAULT;
2033 break;
2034
2035 case TUNSETVNETHDRSZ:
2036 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
2037 ret = -EFAULT;
2038 break;
2039 }
2040 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
2041 ret = -EINVAL;
2042 break;
2043 }
2044
2045 tun->vnet_hdr_sz = vnet_hdr_sz;
2046 break;
2047
2048 case TUNGETVNETLE:
2049 le = !!(tun->flags & TUN_VNET_LE);
2050 if (put_user(le, (int __user *)argp))
2051 ret = -EFAULT;
2052 break;
2053
2054 case TUNSETVNETLE:
2055 if (get_user(le, (int __user *)argp)) {
2056 ret = -EFAULT;
2057 break;
2058 }
2059 if (le)
2060 tun->flags |= TUN_VNET_LE;
2061 else
2062 tun->flags &= ~TUN_VNET_LE;
2063 break;
2064
2065 case TUNATTACHFILTER:
2066 /* Can be set only for TAPs */
2067 ret = -EINVAL;
2068 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2069 break;
2070 ret = -EFAULT;
2071 if (copy_from_user(&tun->fprog, argp, sizeof(tun->fprog)))
2072 break;
2073
2074 ret = tun_attach_filter(tun);
2075 break;
2076
2077 case TUNDETACHFILTER:
2078 /* Can be set only for TAPs */
2079 ret = -EINVAL;
2080 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2081 break;
2082 ret = 0;
2083 tun_detach_filter(tun, tun->numqueues);
2084 break;
2085
2086 case TUNGETFILTER:
2087 ret = -EINVAL;
2088 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2089 break;
2090 ret = -EFAULT;
2091 if (copy_to_user(argp, &tun->fprog, sizeof(tun->fprog)))
2092 break;
2093 ret = 0;
2094 break;
2095
2096 default:
2097 ret = -EINVAL;
2098 break;
2099 }
2100
2101 unlock:
2102 rtnl_unlock();
2103 if (tun)
2104 tun_put(tun);
2105 return ret;
2106 }
2107
2108 static long tun_chr_ioctl(struct file *file,
2109 unsigned int cmd, unsigned long arg)
2110 {
2111 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
2112 }
2113
2114 #ifdef CONFIG_COMPAT
2115 static long tun_chr_compat_ioctl(struct file *file,
2116 unsigned int cmd, unsigned long arg)
2117 {
2118 switch (cmd) {
2119 case TUNSETIFF:
2120 case TUNGETIFF:
2121 case TUNSETTXFILTER:
2122 case TUNGETSNDBUF:
2123 case TUNSETSNDBUF:
2124 case SIOCGIFHWADDR:
2125 case SIOCSIFHWADDR:
2126 arg = (unsigned long)compat_ptr(arg);
2127 break;
2128 default:
2129 arg = (compat_ulong_t)arg;
2130 break;
2131 }
2132
2133 /*
2134 * compat_ifreq is shorter than ifreq, so we must not access beyond
2135 * the end of that structure. All fields that are used in this
2136 * driver are compatible though, we don't need to convert the
2137 * contents.
2138 */
2139 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
2140 }
2141 #endif /* CONFIG_COMPAT */
2142
2143 static int tun_chr_fasync(int fd, struct file *file, int on)
2144 {
2145 struct tun_file *tfile = file->private_data;
2146 int ret;
2147
2148 if ((ret = fasync_helper(fd, file, on, &tfile->fasync)) < 0)
2149 goto out;
2150
2151 if (on) {
2152 __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
2153 tfile->flags |= TUN_FASYNC;
2154 } else
2155 tfile->flags &= ~TUN_FASYNC;
2156 ret = 0;
2157 out:
2158 return ret;
2159 }
2160
2161 static int tun_chr_open(struct inode *inode, struct file * file)
2162 {
2163 struct tun_file *tfile;
2164
2165 DBG1(KERN_INFO, "tunX: tun_chr_open\n");
2166
2167 tfile = (struct tun_file *)sk_alloc(&init_net, AF_UNSPEC, GFP_KERNEL,
2168 &tun_proto);
2169 if (!tfile)
2170 return -ENOMEM;
2171 RCU_INIT_POINTER(tfile->tun, NULL);
2172 tfile->net = get_net(current->nsproxy->net_ns);
2173 tfile->flags = 0;
2174 tfile->ifindex = 0;
2175
2176 init_waitqueue_head(&tfile->wq.wait);
2177 RCU_INIT_POINTER(tfile->socket.wq, &tfile->wq);
2178
2179 tfile->socket.file = file;
2180 tfile->socket.ops = &tun_socket_ops;
2181
2182 sock_init_data(&tfile->socket, &tfile->sk);
2183 sk_change_net(&tfile->sk, tfile->net);
2184
2185 tfile->sk.sk_write_space = tun_sock_write_space;
2186 tfile->sk.sk_sndbuf = INT_MAX;
2187
2188 file->private_data = tfile;
2189 set_bit(SOCK_EXTERNALLY_ALLOCATED, &tfile->socket.flags);
2190 INIT_LIST_HEAD(&tfile->next);
2191
2192 sock_set_flag(&tfile->sk, SOCK_ZEROCOPY);
2193
2194 return 0;
2195 }
2196
2197 static int tun_chr_close(struct inode *inode, struct file *file)
2198 {
2199 struct tun_file *tfile = file->private_data;
2200 struct net *net = tfile->net;
2201
2202 tun_detach(tfile, true);
2203 put_net(net);
2204
2205 return 0;
2206 }
2207
2208 #ifdef CONFIG_PROC_FS
2209 static void tun_chr_show_fdinfo(struct seq_file *m, struct file *f)
2210 {
2211 struct tun_struct *tun;
2212 struct ifreq ifr;
2213
2214 memset(&ifr, 0, sizeof(ifr));
2215
2216 rtnl_lock();
2217 tun = tun_get(f);
2218 if (tun)
2219 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
2220 rtnl_unlock();
2221
2222 if (tun)
2223 tun_put(tun);
2224
2225 seq_printf(m, "iff:\t%s\n", ifr.ifr_name);
2226 }
2227 #endif
2228
2229 static const struct file_operations tun_fops = {
2230 .owner = THIS_MODULE,
2231 .llseek = no_llseek,
2232 .read = new_sync_read,
2233 .write = new_sync_write,
2234 .read_iter = tun_chr_read_iter,
2235 .write_iter = tun_chr_write_iter,
2236 .poll = tun_chr_poll,
2237 .unlocked_ioctl = tun_chr_ioctl,
2238 #ifdef CONFIG_COMPAT
2239 .compat_ioctl = tun_chr_compat_ioctl,
2240 #endif
2241 .open = tun_chr_open,
2242 .release = tun_chr_close,
2243 .fasync = tun_chr_fasync,
2244 #ifdef CONFIG_PROC_FS
2245 .show_fdinfo = tun_chr_show_fdinfo,
2246 #endif
2247 };
2248
2249 static struct miscdevice tun_miscdev = {
2250 .minor = TUN_MINOR,
2251 .name = "tun",
2252 .nodename = "net/tun",
2253 .fops = &tun_fops,
2254 };
2255
2256 /* ethtool interface */
2257
2258 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
2259 {
2260 cmd->supported = 0;
2261 cmd->advertising = 0;
2262 ethtool_cmd_speed_set(cmd, SPEED_10);
2263 cmd->duplex = DUPLEX_FULL;
2264 cmd->port = PORT_TP;
2265 cmd->phy_address = 0;
2266 cmd->transceiver = XCVR_INTERNAL;
2267 cmd->autoneg = AUTONEG_DISABLE;
2268 cmd->maxtxpkt = 0;
2269 cmd->maxrxpkt = 0;
2270 return 0;
2271 }
2272
2273 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
2274 {
2275 struct tun_struct *tun = netdev_priv(dev);
2276
2277 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
2278 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
2279
2280 switch (tun->flags & TUN_TYPE_MASK) {
2281 case IFF_TUN:
2282 strlcpy(info->bus_info, "tun", sizeof(info->bus_info));
2283 break;
2284 case IFF_TAP:
2285 strlcpy(info->bus_info, "tap", sizeof(info->bus_info));
2286 break;
2287 }
2288 }
2289
2290 static u32 tun_get_msglevel(struct net_device *dev)
2291 {
2292 #ifdef TUN_DEBUG
2293 struct tun_struct *tun = netdev_priv(dev);
2294 return tun->debug;
2295 #else
2296 return -EOPNOTSUPP;
2297 #endif
2298 }
2299
2300 static void tun_set_msglevel(struct net_device *dev, u32 value)
2301 {
2302 #ifdef TUN_DEBUG
2303 struct tun_struct *tun = netdev_priv(dev);
2304 tun->debug = value;
2305 #endif
2306 }
2307
2308 static const struct ethtool_ops tun_ethtool_ops = {
2309 .get_settings = tun_get_settings,
2310 .get_drvinfo = tun_get_drvinfo,
2311 .get_msglevel = tun_get_msglevel,
2312 .set_msglevel = tun_set_msglevel,
2313 .get_link = ethtool_op_get_link,
2314 .get_ts_info = ethtool_op_get_ts_info,
2315 };
2316
2317
2318 static int __init tun_init(void)
2319 {
2320 int ret = 0;
2321
2322 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
2323 pr_info("%s\n", DRV_COPYRIGHT);
2324
2325 ret = rtnl_link_register(&tun_link_ops);
2326 if (ret) {
2327 pr_err("Can't register link_ops\n");
2328 goto err_linkops;
2329 }
2330
2331 ret = misc_register(&tun_miscdev);
2332 if (ret) {
2333 pr_err("Can't register misc device %d\n", TUN_MINOR);
2334 goto err_misc;
2335 }
2336 return 0;
2337 err_misc:
2338 rtnl_link_unregister(&tun_link_ops);
2339 err_linkops:
2340 return ret;
2341 }
2342
2343 static void tun_cleanup(void)
2344 {
2345 misc_deregister(&tun_miscdev);
2346 rtnl_link_unregister(&tun_link_ops);
2347 }
2348
2349 /* Get an underlying socket object from tun file. Returns error unless file is
2350 * attached to a device. The returned object works like a packet socket, it
2351 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
2352 * holding a reference to the file for as long as the socket is in use. */
2353 struct socket *tun_get_socket(struct file *file)
2354 {
2355 struct tun_file *tfile;
2356 if (file->f_op != &tun_fops)
2357 return ERR_PTR(-EINVAL);
2358 tfile = file->private_data;
2359 if (!tfile)
2360 return ERR_PTR(-EBADFD);
2361 return &tfile->socket;
2362 }
2363 EXPORT_SYMBOL_GPL(tun_get_socket);
2364
2365 module_init(tun_init);
2366 module_exit(tun_cleanup);
2367 MODULE_DESCRIPTION(DRV_DESCRIPTION);
2368 MODULE_AUTHOR(DRV_COPYRIGHT);
2369 MODULE_LICENSE("GPL");
2370 MODULE_ALIAS_MISCDEV(TUN_MINOR);
2371 MODULE_ALIAS("devname:net/tun");
Linux with added FPC-III support