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perf tools: Be consistent on the type of map->symbols[] interator
[linux/fpc-iii.git] / drivers / net / tun.c
blobbfabe180053e414dee777e0e56b24eceef05c918
1 /*
2 * TUN - Universal TUN/TAP device driver.
3 * Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $
16 */
17
18 /*
19 * Changes:
20 *
21 * Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
22 * Add TUNSETLINK ioctl to set the link encapsulation
23 *
24 * Mark Smith <markzzzsmith@yahoo.com.au>
25 * Use eth_random_addr() for tap MAC address.
26 *
27 * Harald Roelle <harald.roelle@ifi.lmu.de> 2004/04/20
28 * Fixes in packet dropping, queue length setting and queue wakeup.
29 * Increased default tx queue length.
30 * Added ethtool API.
31 * Minor cleanups
32 *
33 * Daniel Podlejski <underley@underley.eu.org>
34 * Modifications for 2.3.99-pre5 kernel.
35 */
36
37 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
38
39 #define DRV_NAME "tun"
40 #define DRV_VERSION "1.6"
41 #define DRV_DESCRIPTION "Universal TUN/TAP device driver"
42 #define DRV_COPYRIGHT "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>"
43
44 #include <linux/module.h>
45 #include <linux/errno.h>
46 #include <linux/kernel.h>
47 #include <linux/major.h>
48 #include <linux/slab.h>
49 #include <linux/poll.h>
50 #include <linux/fcntl.h>
51 #include <linux/init.h>
52 #include <linux/skbuff.h>
53 #include <linux/netdevice.h>
54 #include <linux/etherdevice.h>
55 #include <linux/miscdevice.h>
56 #include <linux/ethtool.h>
57 #include <linux/rtnetlink.h>
58 #include <linux/compat.h>
59 #include <linux/if.h>
60 #include <linux/if_arp.h>
61 #include <linux/if_ether.h>
62 #include <linux/if_tun.h>
63 #include <linux/if_vlan.h>
64 #include <linux/crc32.h>
65 #include <linux/nsproxy.h>
66 #include <linux/virtio_net.h>
67 #include <linux/rcupdate.h>
68 #include <net/net_namespace.h>
69 #include <net/netns/generic.h>
70 #include <net/rtnetlink.h>
71 #include <net/sock.h>
72 #include <linux/seq_file.h>
73 #include <linux/uio.h>
74 #include <linux/skb_array.h>
75
76 #include <linux/uaccess.h>
77
78 /* Uncomment to enable debugging */
79 /* #define TUN_DEBUG 1 */
80
81 #ifdef TUN_DEBUG
82 static int debug;
83
84 #define tun_debug(level, tun, fmt, args...) \
85 do { \
86 if (tun->debug) \
87 netdev_printk(level, tun->dev, fmt, ##args); \
88 } while (0)
89 #define DBG1(level, fmt, args...) \
90 do { \
91 if (debug == 2) \
92 printk(level fmt, ##args); \
93 } while (0)
94 #else
95 #define tun_debug(level, tun, fmt, args...) \
96 do { \
97 if (0) \
98 netdev_printk(level, tun->dev, fmt, ##args); \
99 } while (0)
100 #define DBG1(level, fmt, args...) \
101 do { \
102 if (0) \
103 printk(level fmt, ##args); \
104 } while (0)
105 #endif
106
107 /* TUN device flags */
108
109 /* IFF_ATTACH_QUEUE is never stored in device flags,
110 * overload it to mean fasync when stored there.
111 */
112 #define TUN_FASYNC IFF_ATTACH_QUEUE
113 /* High bits in flags field are unused. */
114 #define TUN_VNET_LE 0x80000000
115 #define TUN_VNET_BE 0x40000000
116
117 #define TUN_FEATURES (IFF_NO_PI | IFF_ONE_QUEUE | IFF_VNET_HDR | \
118 IFF_MULTI_QUEUE)
119 #define GOODCOPY_LEN 128
120
121 #define FLT_EXACT_COUNT 8
122 struct tap_filter {
123 unsigned int count; /* Number of addrs. Zero means disabled */
124 u32 mask[2]; /* Mask of the hashed addrs */
125 unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN];
126 };
127
128 /* MAX_TAP_QUEUES 256 is chosen to allow rx/tx queues to be equal
129 * to max number of VCPUs in guest. */
130 #define MAX_TAP_QUEUES 256
131 #define MAX_TAP_FLOWS 4096
132
133 #define TUN_FLOW_EXPIRE (3 * HZ)
134
135 struct tun_pcpu_stats {
136 u64 rx_packets;
137 u64 rx_bytes;
138 u64 tx_packets;
139 u64 tx_bytes;
140 struct u64_stats_sync syncp;
141 u32 rx_dropped;
142 u32 tx_dropped;
143 u32 rx_frame_errors;
144 };
145
146 /* A tun_file connects an open character device to a tuntap netdevice. It
147 * also contains all socket related structures (except sock_fprog and tap_filter)
148 * to serve as one transmit queue for tuntap device. The sock_fprog and
149 * tap_filter were kept in tun_struct since they were used for filtering for the
150 * netdevice not for a specific queue (at least I didn't see the requirement for
151 * this).
152 *
153 * RCU usage:
154 * The tun_file and tun_struct are loosely coupled, the pointer from one to the
155 * other can only be read while rcu_read_lock or rtnl_lock is held.
156 */
157 struct tun_file {
158 struct sock sk;
159 struct socket socket;
160 struct socket_wq wq;
161 struct tun_struct __rcu *tun;
162 struct fasync_struct *fasync;
163 /* only used for fasnyc */
164 unsigned int flags;
165 union {
166 u16 queue_index;
167 unsigned int ifindex;
168 };
169 struct list_head next;
170 struct tun_struct *detached;
171 struct skb_array tx_array;
172 };
173
174 struct tun_flow_entry {
175 struct hlist_node hash_link;
176 struct rcu_head rcu;
177 struct tun_struct *tun;
178
179 u32 rxhash;
180 u32 rps_rxhash;
181 int queue_index;
182 unsigned long updated;
183 };
184
185 #define TUN_NUM_FLOW_ENTRIES 1024
186
187 /* Since the socket were moved to tun_file, to preserve the behavior of persist
188 * device, socket filter, sndbuf and vnet header size were restore when the
189 * file were attached to a persist device.
190 */
191 struct tun_struct {
192 struct tun_file __rcu *tfiles[MAX_TAP_QUEUES];
193 unsigned int numqueues;
194 unsigned int flags;
195 kuid_t owner;
196 kgid_t group;
197
198 struct net_device *dev;
199 netdev_features_t set_features;
200 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
201 NETIF_F_TSO6|NETIF_F_UFO)
202
203 int align;
204 int vnet_hdr_sz;
205 int sndbuf;
206 struct tap_filter txflt;
207 struct sock_fprog fprog;
208 /* protected by rtnl lock */
209 bool filter_attached;
210 #ifdef TUN_DEBUG
211 int debug;
212 #endif
213 spinlock_t lock;
214 struct hlist_head flows[TUN_NUM_FLOW_ENTRIES];
215 struct timer_list flow_gc_timer;
216 unsigned long ageing_time;
217 unsigned int numdisabled;
218 struct list_head disabled;
219 void *security;
220 u32 flow_count;
221 struct tun_pcpu_stats __percpu *pcpu_stats;
222 };
223
224 #ifdef CONFIG_TUN_VNET_CROSS_LE
225 static inline bool tun_legacy_is_little_endian(struct tun_struct *tun)
226 {
227 return tun->flags & TUN_VNET_BE ? false :
228 virtio_legacy_is_little_endian();
229 }
230
231 static long tun_get_vnet_be(struct tun_struct *tun, int __user *argp)
232 {
233 int be = !!(tun->flags & TUN_VNET_BE);
234
235 if (put_user(be, argp))
236 return -EFAULT;
237
238 return 0;
239 }
240
241 static long tun_set_vnet_be(struct tun_struct *tun, int __user *argp)
242 {
243 int be;
244
245 if (get_user(be, argp))
246 return -EFAULT;
247
248 if (be)
249 tun->flags |= TUN_VNET_BE;
250 else
251 tun->flags &= ~TUN_VNET_BE;
252
253 return 0;
254 }
255 #else
256 static inline bool tun_legacy_is_little_endian(struct tun_struct *tun)
257 {
258 return virtio_legacy_is_little_endian();
259 }
260
261 static long tun_get_vnet_be(struct tun_struct *tun, int __user *argp)
262 {
263 return -EINVAL;
264 }
265
266 static long tun_set_vnet_be(struct tun_struct *tun, int __user *argp)
267 {
268 return -EINVAL;
269 }
270 #endif /* CONFIG_TUN_VNET_CROSS_LE */
271
272 static inline bool tun_is_little_endian(struct tun_struct *tun)
273 {
274 return tun->flags & TUN_VNET_LE ||
275 tun_legacy_is_little_endian(tun);
276 }
277
278 static inline u16 tun16_to_cpu(struct tun_struct *tun, __virtio16 val)
279 {
280 return __virtio16_to_cpu(tun_is_little_endian(tun), val);
281 }
282
283 static inline __virtio16 cpu_to_tun16(struct tun_struct *tun, u16 val)
284 {
285 return __cpu_to_virtio16(tun_is_little_endian(tun), val);
286 }
287
288 static inline u32 tun_hashfn(u32 rxhash)
289 {
290 return rxhash & 0x3ff;
291 }
292
293 static struct tun_flow_entry *tun_flow_find(struct hlist_head *head, u32 rxhash)
294 {
295 struct tun_flow_entry *e;
296
297 hlist_for_each_entry_rcu(e, head, hash_link) {
298 if (e->rxhash == rxhash)
299 return e;
300 }
301 return NULL;
302 }
303
304 static struct tun_flow_entry *tun_flow_create(struct tun_struct *tun,
305 struct hlist_head *head,
306 u32 rxhash, u16 queue_index)
307 {
308 struct tun_flow_entry *e = kmalloc(sizeof(*e), GFP_ATOMIC);
309
310 if (e) {
311 tun_debug(KERN_INFO, tun, "create flow: hash %u index %u\n",
312 rxhash, queue_index);
313 e->updated = jiffies;
314 e->rxhash = rxhash;
315 e->rps_rxhash = 0;
316 e->queue_index = queue_index;
317 e->tun = tun;
318 hlist_add_head_rcu(&e->hash_link, head);
319 ++tun->flow_count;
320 }
321 return e;
322 }
323
324 static void tun_flow_delete(struct tun_struct *tun, struct tun_flow_entry *e)
325 {
326 tun_debug(KERN_INFO, tun, "delete flow: hash %u index %u\n",
327 e->rxhash, e->queue_index);
328 hlist_del_rcu(&e->hash_link);
329 kfree_rcu(e, rcu);
330 --tun->flow_count;
331 }
332
333 static void tun_flow_flush(struct tun_struct *tun)
334 {
335 int i;
336
337 spin_lock_bh(&tun->lock);
338 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
339 struct tun_flow_entry *e;
340 struct hlist_node *n;
341
342 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link)
343 tun_flow_delete(tun, e);
344 }
345 spin_unlock_bh(&tun->lock);
346 }
347
348 static void tun_flow_delete_by_queue(struct tun_struct *tun, u16 queue_index)
349 {
350 int i;
351
352 spin_lock_bh(&tun->lock);
353 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
354 struct tun_flow_entry *e;
355 struct hlist_node *n;
356
357 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
358 if (e->queue_index == queue_index)
359 tun_flow_delete(tun, e);
360 }
361 }
362 spin_unlock_bh(&tun->lock);
363 }
364
365 static void tun_flow_cleanup(unsigned long data)
366 {
367 struct tun_struct *tun = (struct tun_struct *)data;
368 unsigned long delay = tun->ageing_time;
369 unsigned long next_timer = jiffies + delay;
370 unsigned long count = 0;
371 int i;
372
373 tun_debug(KERN_INFO, tun, "tun_flow_cleanup\n");
374
375 spin_lock_bh(&tun->lock);
376 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
377 struct tun_flow_entry *e;
378 struct hlist_node *n;
379
380 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
381 unsigned long this_timer;
382 count++;
383 this_timer = e->updated + delay;
384 if (time_before_eq(this_timer, jiffies))
385 tun_flow_delete(tun, e);
386 else if (time_before(this_timer, next_timer))
387 next_timer = this_timer;
388 }
389 }
390
391 if (count)
392 mod_timer(&tun->flow_gc_timer, round_jiffies_up(next_timer));
393 spin_unlock_bh(&tun->lock);
394 }
395
396 static void tun_flow_update(struct tun_struct *tun, u32 rxhash,
397 struct tun_file *tfile)
398 {
399 struct hlist_head *head;
400 struct tun_flow_entry *e;
401 unsigned long delay = tun->ageing_time;
402 u16 queue_index = tfile->queue_index;
403
404 if (!rxhash)
405 return;
406 else
407 head = &tun->flows[tun_hashfn(rxhash)];
408
409 rcu_read_lock();
410
411 /* We may get a very small possibility of OOO during switching, not
412 * worth to optimize.*/
413 if (tun->numqueues == 1 || tfile->detached)
414 goto unlock;
415
416 e = tun_flow_find(head, rxhash);
417 if (likely(e)) {
418 /* TODO: keep queueing to old queue until it's empty? */
419 e->queue_index = queue_index;
420 e->updated = jiffies;
421 sock_rps_record_flow_hash(e->rps_rxhash);
422 } else {
423 spin_lock_bh(&tun->lock);
424 if (!tun_flow_find(head, rxhash) &&
425 tun->flow_count < MAX_TAP_FLOWS)
426 tun_flow_create(tun, head, rxhash, queue_index);
427
428 if (!timer_pending(&tun->flow_gc_timer))
429 mod_timer(&tun->flow_gc_timer,
430 round_jiffies_up(jiffies + delay));
431 spin_unlock_bh(&tun->lock);
432 }
433
434 unlock:
435 rcu_read_unlock();
436 }
437
438 /**
439 * Save the hash received in the stack receive path and update the
440 * flow_hash table accordingly.
441 */
442 static inline void tun_flow_save_rps_rxhash(struct tun_flow_entry *e, u32 hash)
443 {
444 if (unlikely(e->rps_rxhash != hash))
445 e->rps_rxhash = hash;
446 }
447
448 /* We try to identify a flow through its rxhash first. The reason that
449 * we do not check rxq no. is because some cards(e.g 82599), chooses
450 * the rxq based on the txq where the last packet of the flow comes. As
451 * the userspace application move between processors, we may get a
452 * different rxq no. here. If we could not get rxhash, then we would
453 * hope the rxq no. may help here.
454 */
455 static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb,
456 void *accel_priv, select_queue_fallback_t fallback)
457 {
458 struct tun_struct *tun = netdev_priv(dev);
459 struct tun_flow_entry *e;
460 u32 txq = 0;
461 u32 numqueues = 0;
462
463 rcu_read_lock();
464 numqueues = ACCESS_ONCE(tun->numqueues);
465
466 txq = skb_get_hash(skb);
467 if (txq) {
468 e = tun_flow_find(&tun->flows[tun_hashfn(txq)], txq);
469 if (e) {
470 tun_flow_save_rps_rxhash(e, txq);
471 txq = e->queue_index;
472 } else
473 /* use multiply and shift instead of expensive divide */
474 txq = ((u64)txq * numqueues) >> 32;
475 } else if (likely(skb_rx_queue_recorded(skb))) {
476 txq = skb_get_rx_queue(skb);
477 while (unlikely(txq >= numqueues))
478 txq -= numqueues;
479 }
480
481 rcu_read_unlock();
482 return txq;
483 }
484
485 static inline bool tun_not_capable(struct tun_struct *tun)
486 {
487 const struct cred *cred = current_cred();
488 struct net *net = dev_net(tun->dev);
489
490 return ((uid_valid(tun->owner) && !uid_eq(cred->euid, tun->owner)) ||
491 (gid_valid(tun->group) && !in_egroup_p(tun->group))) &&
492 !ns_capable(net->user_ns, CAP_NET_ADMIN);
493 }
494
495 static void tun_set_real_num_queues(struct tun_struct *tun)
496 {
497 netif_set_real_num_tx_queues(tun->dev, tun->numqueues);
498 netif_set_real_num_rx_queues(tun->dev, tun->numqueues);
499 }
500
501 static void tun_disable_queue(struct tun_struct *tun, struct tun_file *tfile)
502 {
503 tfile->detached = tun;
504 list_add_tail(&tfile->next, &tun->disabled);
505 ++tun->numdisabled;
506 }
507
508 static struct tun_struct *tun_enable_queue(struct tun_file *tfile)
509 {
510 struct tun_struct *tun = tfile->detached;
511
512 tfile->detached = NULL;
513 list_del_init(&tfile->next);
514 --tun->numdisabled;
515 return tun;
516 }
517
518 static void tun_queue_purge(struct tun_file *tfile)
519 {
520 struct sk_buff *skb;
521
522 while ((skb = skb_array_consume(&tfile->tx_array)) != NULL)
523 kfree_skb(skb);
524
525 skb_queue_purge(&tfile->sk.sk_error_queue);
526 }
527
528 static void __tun_detach(struct tun_file *tfile, bool clean)
529 {
530 struct tun_file *ntfile;
531 struct tun_struct *tun;
532
533 tun = rtnl_dereference(tfile->tun);
534
535 if (tun && !tfile->detached) {
536 u16 index = tfile->queue_index;
537 BUG_ON(index >= tun->numqueues);
538
539 rcu_assign_pointer(tun->tfiles[index],
540 tun->tfiles[tun->numqueues - 1]);
541 ntfile = rtnl_dereference(tun->tfiles[index]);
542 ntfile->queue_index = index;
543
544 --tun->numqueues;
545 if (clean) {
546 RCU_INIT_POINTER(tfile->tun, NULL);
547 sock_put(&tfile->sk);
548 } else
549 tun_disable_queue(tun, tfile);
550
551 synchronize_net();
552 tun_flow_delete_by_queue(tun, tun->numqueues + 1);
553 /* Drop read queue */
554 tun_queue_purge(tfile);
555 tun_set_real_num_queues(tun);
556 } else if (tfile->detached && clean) {
557 tun = tun_enable_queue(tfile);
558 sock_put(&tfile->sk);
559 }
560
561 if (clean) {
562 if (tun && tun->numqueues == 0 && tun->numdisabled == 0) {
563 netif_carrier_off(tun->dev);
564
565 if (!(tun->flags & IFF_PERSIST) &&
566 tun->dev->reg_state == NETREG_REGISTERED)
567 unregister_netdevice(tun->dev);
568 }
569 if (tun)
570 skb_array_cleanup(&tfile->tx_array);
571 sock_put(&tfile->sk);
572 }
573 }
574
575 static void tun_detach(struct tun_file *tfile, bool clean)
576 {
577 rtnl_lock();
578 __tun_detach(tfile, clean);
579 rtnl_unlock();
580 }
581
582 static void tun_detach_all(struct net_device *dev)
583 {
584 struct tun_struct *tun = netdev_priv(dev);
585 struct tun_file *tfile, *tmp;
586 int i, n = tun->numqueues;
587
588 for (i = 0; i < n; i++) {
589 tfile = rtnl_dereference(tun->tfiles[i]);
590 BUG_ON(!tfile);
591 tfile->socket.sk->sk_shutdown = RCV_SHUTDOWN;
592 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
593 RCU_INIT_POINTER(tfile->tun, NULL);
594 --tun->numqueues;
595 }
596 list_for_each_entry(tfile, &tun->disabled, next) {
597 tfile->socket.sk->sk_shutdown = RCV_SHUTDOWN;
598 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
599 RCU_INIT_POINTER(tfile->tun, NULL);
600 }
601 BUG_ON(tun->numqueues != 0);
602
603 synchronize_net();
604 for (i = 0; i < n; i++) {
605 tfile = rtnl_dereference(tun->tfiles[i]);
606 /* Drop read queue */
607 tun_queue_purge(tfile);
608 sock_put(&tfile->sk);
609 }
610 list_for_each_entry_safe(tfile, tmp, &tun->disabled, next) {
611 tun_enable_queue(tfile);
612 tun_queue_purge(tfile);
613 sock_put(&tfile->sk);
614 }
615 BUG_ON(tun->numdisabled != 0);
616
617 if (tun->flags & IFF_PERSIST)
618 module_put(THIS_MODULE);
619 }
620
621 static int tun_attach(struct tun_struct *tun, struct file *file, bool skip_filter)
622 {
623 struct tun_file *tfile = file->private_data;
624 struct net_device *dev = tun->dev;
625 int err;
626
627 err = security_tun_dev_attach(tfile->socket.sk, tun->security);
628 if (err < 0)
629 goto out;
630
631 err = -EINVAL;
632 if (rtnl_dereference(tfile->tun) && !tfile->detached)
633 goto out;
634
635 err = -EBUSY;
636 if (!(tun->flags & IFF_MULTI_QUEUE) && tun->numqueues == 1)
637 goto out;
638
639 err = -E2BIG;
640 if (!tfile->detached &&
641 tun->numqueues + tun->numdisabled == MAX_TAP_QUEUES)
642 goto out;
643
644 err = 0;
645
646 /* Re-attach the filter to persist device */
647 if (!skip_filter && (tun->filter_attached == true)) {
648 lock_sock(tfile->socket.sk);
649 err = sk_attach_filter(&tun->fprog, tfile->socket.sk);
650 release_sock(tfile->socket.sk);
651 if (!err)
652 goto out;
653 }
654
655 if (!tfile->detached &&
656 skb_array_init(&tfile->tx_array, dev->tx_queue_len, GFP_KERNEL)) {
657 err = -ENOMEM;
658 goto out;
659 }
660
661 tfile->queue_index = tun->numqueues;
662 tfile->socket.sk->sk_shutdown &= ~RCV_SHUTDOWN;
663 rcu_assign_pointer(tfile->tun, tun);
664 rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile);
665 tun->numqueues++;
666
667 if (tfile->detached)
668 tun_enable_queue(tfile);
669 else
670 sock_hold(&tfile->sk);
671
672 tun_set_real_num_queues(tun);
673
674 /* device is allowed to go away first, so no need to hold extra
675 * refcnt.
676 */
677
678 out:
679 return err;
680 }
681
682 static struct tun_struct *__tun_get(struct tun_file *tfile)
683 {
684 struct tun_struct *tun;
685
686 rcu_read_lock();
687 tun = rcu_dereference(tfile->tun);
688 if (tun)
689 dev_hold(tun->dev);
690 rcu_read_unlock();
691
692 return tun;
693 }
694
695 static struct tun_struct *tun_get(struct file *file)
696 {
697 return __tun_get(file->private_data);
698 }
699
700 static void tun_put(struct tun_struct *tun)
701 {
702 dev_put(tun->dev);
703 }
704
705 /* TAP filtering */
706 static void addr_hash_set(u32 *mask, const u8 *addr)
707 {
708 int n = ether_crc(ETH_ALEN, addr) >> 26;
709 mask[n >> 5] |= (1 << (n & 31));
710 }
711
712 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
713 {
714 int n = ether_crc(ETH_ALEN, addr) >> 26;
715 return mask[n >> 5] & (1 << (n & 31));
716 }
717
718 static int update_filter(struct tap_filter *filter, void __user *arg)
719 {
720 struct { u8 u[ETH_ALEN]; } *addr;
721 struct tun_filter uf;
722 int err, alen, n, nexact;
723
724 if (copy_from_user(&uf, arg, sizeof(uf)))
725 return -EFAULT;
726
727 if (!uf.count) {
728 /* Disabled */
729 filter->count = 0;
730 return 0;
731 }
732
733 alen = ETH_ALEN * uf.count;
734 addr = memdup_user(arg + sizeof(uf), alen);
735 if (IS_ERR(addr))
736 return PTR_ERR(addr);
737
738 /* The filter is updated without holding any locks. Which is
739 * perfectly safe. We disable it first and in the worst
740 * case we'll accept a few undesired packets. */
741 filter->count = 0;
742 wmb();
743
744 /* Use first set of addresses as an exact filter */
745 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
746 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
747
748 nexact = n;
749
750 /* Remaining multicast addresses are hashed,
751 * unicast will leave the filter disabled. */
752 memset(filter->mask, 0, sizeof(filter->mask));
753 for (; n < uf.count; n++) {
754 if (!is_multicast_ether_addr(addr[n].u)) {
755 err = 0; /* no filter */
756 goto free_addr;
757 }
758 addr_hash_set(filter->mask, addr[n].u);
759 }
760
761 /* For ALLMULTI just set the mask to all ones.
762 * This overrides the mask populated above. */
763 if ((uf.flags & TUN_FLT_ALLMULTI))
764 memset(filter->mask, ~0, sizeof(filter->mask));
765
766 /* Now enable the filter */
767 wmb();
768 filter->count = nexact;
769
770 /* Return the number of exact filters */
771 err = nexact;
772 free_addr:
773 kfree(addr);
774 return err;
775 }
776
777 /* Returns: 0 - drop, !=0 - accept */
778 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
779 {
780 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
781 * at this point. */
782 struct ethhdr *eh = (struct ethhdr *) skb->data;
783 int i;
784
785 /* Exact match */
786 for (i = 0; i < filter->count; i++)
787 if (ether_addr_equal(eh->h_dest, filter->addr[i]))
788 return 1;
789
790 /* Inexact match (multicast only) */
791 if (is_multicast_ether_addr(eh->h_dest))
792 return addr_hash_test(filter->mask, eh->h_dest);
793
794 return 0;
795 }
796
797 /*
798 * Checks whether the packet is accepted or not.
799 * Returns: 0 - drop, !=0 - accept
800 */
801 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
802 {
803 if (!filter->count)
804 return 1;
805
806 return run_filter(filter, skb);
807 }
808
809 /* Network device part of the driver */
810
811 static const struct ethtool_ops tun_ethtool_ops;
812
813 /* Net device detach from fd. */
814 static void tun_net_uninit(struct net_device *dev)
815 {
816 tun_detach_all(dev);
817 }
818
819 /* Net device open. */
820 static int tun_net_open(struct net_device *dev)
821 {
822 netif_tx_start_all_queues(dev);
823 return 0;
824 }
825
826 /* Net device close. */
827 static int tun_net_close(struct net_device *dev)
828 {
829 netif_tx_stop_all_queues(dev);
830 return 0;
831 }
832
833 /* Net device start xmit */
834 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
835 {
836 struct tun_struct *tun = netdev_priv(dev);
837 int txq = skb->queue_mapping;
838 struct tun_file *tfile;
839 u32 numqueues = 0;
840
841 rcu_read_lock();
842 tfile = rcu_dereference(tun->tfiles[txq]);
843 numqueues = ACCESS_ONCE(tun->numqueues);
844
845 /* Drop packet if interface is not attached */
846 if (txq >= numqueues)
847 goto drop;
848
849 #ifdef CONFIG_RPS
850 if (numqueues == 1 && static_key_false(&rps_needed)) {
851 /* Select queue was not called for the skbuff, so we extract the
852 * RPS hash and save it into the flow_table here.
853 */
854 __u32 rxhash;
855
856 rxhash = skb_get_hash(skb);
857 if (rxhash) {
858 struct tun_flow_entry *e;
859 e = tun_flow_find(&tun->flows[tun_hashfn(rxhash)],
860 rxhash);
861 if (e)
862 tun_flow_save_rps_rxhash(e, rxhash);
863 }
864 }
865 #endif
866
867 tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len);
868
869 BUG_ON(!tfile);
870
871 /* Drop if the filter does not like it.
872 * This is a noop if the filter is disabled.
873 * Filter can be enabled only for the TAP devices. */
874 if (!check_filter(&tun->txflt, skb))
875 goto drop;
876
877 if (tfile->socket.sk->sk_filter &&
878 sk_filter(tfile->socket.sk, skb))
879 goto drop;
880
881 if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
882 goto drop;
883
884 skb_tx_timestamp(skb);
885
886 /* Orphan the skb - required as we might hang on to it
887 * for indefinite time.
888 */
889 skb_orphan(skb);
890
891 nf_reset(skb);
892
893 if (skb_array_produce(&tfile->tx_array, skb))
894 goto drop;
895
896 /* Notify and wake up reader process */
897 if (tfile->flags & TUN_FASYNC)
898 kill_fasync(&tfile->fasync, SIGIO, POLL_IN);
899 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
900
901 rcu_read_unlock();
902 return NETDEV_TX_OK;
903
904 drop:
905 this_cpu_inc(tun->pcpu_stats->tx_dropped);
906 skb_tx_error(skb);
907 kfree_skb(skb);
908 rcu_read_unlock();
909 return NET_XMIT_DROP;
910 }
911
912 static void tun_net_mclist(struct net_device *dev)
913 {
914 /*
915 * This callback is supposed to deal with mc filter in
916 * _rx_ path and has nothing to do with the _tx_ path.
917 * In rx path we always accept everything userspace gives us.
918 */
919 }
920
921 static netdev_features_t tun_net_fix_features(struct net_device *dev,
922 netdev_features_t features)
923 {
924 struct tun_struct *tun = netdev_priv(dev);
925
926 return (features & tun->set_features) | (features & ~TUN_USER_FEATURES);
927 }
928 #ifdef CONFIG_NET_POLL_CONTROLLER
929 static void tun_poll_controller(struct net_device *dev)
930 {
931 /*
932 * Tun only receives frames when:
933 * 1) the char device endpoint gets data from user space
934 * 2) the tun socket gets a sendmsg call from user space
935 * Since both of those are synchronous operations, we are guaranteed
936 * never to have pending data when we poll for it
937 * so there is nothing to do here but return.
938 * We need this though so netpoll recognizes us as an interface that
939 * supports polling, which enables bridge devices in virt setups to
940 * still use netconsole
941 */
942 return;
943 }
944 #endif
945
946 static void tun_set_headroom(struct net_device *dev, int new_hr)
947 {
948 struct tun_struct *tun = netdev_priv(dev);
949
950 if (new_hr < NET_SKB_PAD)
951 new_hr = NET_SKB_PAD;
952
953 tun->align = new_hr;
954 }
955
956 static struct rtnl_link_stats64 *
957 tun_net_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
958 {
959 u32 rx_dropped = 0, tx_dropped = 0, rx_frame_errors = 0;
960 struct tun_struct *tun = netdev_priv(dev);
961 struct tun_pcpu_stats *p;
962 int i;
963
964 for_each_possible_cpu(i) {
965 u64 rxpackets, rxbytes, txpackets, txbytes;
966 unsigned int start;
967
968 p = per_cpu_ptr(tun->pcpu_stats, i);
969 do {
970 start = u64_stats_fetch_begin(&p->syncp);
971 rxpackets = p->rx_packets;
972 rxbytes = p->rx_bytes;
973 txpackets = p->tx_packets;
974 txbytes = p->tx_bytes;
975 } while (u64_stats_fetch_retry(&p->syncp, start));
976
977 stats->rx_packets += rxpackets;
978 stats->rx_bytes += rxbytes;
979 stats->tx_packets += txpackets;
980 stats->tx_bytes += txbytes;
981
982 /* u32 counters */
983 rx_dropped += p->rx_dropped;
984 rx_frame_errors += p->rx_frame_errors;
985 tx_dropped += p->tx_dropped;
986 }
987 stats->rx_dropped = rx_dropped;
988 stats->rx_frame_errors = rx_frame_errors;
989 stats->tx_dropped = tx_dropped;
990 return stats;
991 }
992
993 static const struct net_device_ops tun_netdev_ops = {
994 .ndo_uninit = tun_net_uninit,
995 .ndo_open = tun_net_open,
996 .ndo_stop = tun_net_close,
997 .ndo_start_xmit = tun_net_xmit,
998 .ndo_fix_features = tun_net_fix_features,
999 .ndo_select_queue = tun_select_queue,
1000 #ifdef CONFIG_NET_POLL_CONTROLLER
1001 .ndo_poll_controller = tun_poll_controller,
1002 #endif
1003 .ndo_set_rx_headroom = tun_set_headroom,
1004 .ndo_get_stats64 = tun_net_get_stats64,
1005 };
1006
1007 static const struct net_device_ops tap_netdev_ops = {
1008 .ndo_uninit = tun_net_uninit,
1009 .ndo_open = tun_net_open,
1010 .ndo_stop = tun_net_close,
1011 .ndo_start_xmit = tun_net_xmit,
1012 .ndo_fix_features = tun_net_fix_features,
1013 .ndo_set_rx_mode = tun_net_mclist,
1014 .ndo_set_mac_address = eth_mac_addr,
1015 .ndo_validate_addr = eth_validate_addr,
1016 .ndo_select_queue = tun_select_queue,
1017 #ifdef CONFIG_NET_POLL_CONTROLLER
1018 .ndo_poll_controller = tun_poll_controller,
1019 #endif
1020 .ndo_features_check = passthru_features_check,
1021 .ndo_set_rx_headroom = tun_set_headroom,
1022 .ndo_get_stats64 = tun_net_get_stats64,
1023 };
1024
1025 static void tun_flow_init(struct tun_struct *tun)
1026 {
1027 int i;
1028
1029 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++)
1030 INIT_HLIST_HEAD(&tun->flows[i]);
1031
1032 tun->ageing_time = TUN_FLOW_EXPIRE;
1033 setup_timer(&tun->flow_gc_timer, tun_flow_cleanup, (unsigned long)tun);
1034 mod_timer(&tun->flow_gc_timer,
1035 round_jiffies_up(jiffies + tun->ageing_time));
1036 }
1037
1038 static void tun_flow_uninit(struct tun_struct *tun)
1039 {
1040 del_timer_sync(&tun->flow_gc_timer);
1041 tun_flow_flush(tun);
1042 }
1043
1044 #define MIN_MTU 68
1045 #define MAX_MTU 65535
1046
1047 /* Initialize net device. */
1048 static void tun_net_init(struct net_device *dev)
1049 {
1050 struct tun_struct *tun = netdev_priv(dev);
1051
1052 switch (tun->flags & TUN_TYPE_MASK) {
1053 case IFF_TUN:
1054 dev->netdev_ops = &tun_netdev_ops;
1055
1056 /* Point-to-Point TUN Device */
1057 dev->hard_header_len = 0;
1058 dev->addr_len = 0;
1059 dev->mtu = 1500;
1060
1061 /* Zero header length */
1062 dev->type = ARPHRD_NONE;
1063 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1064 break;
1065
1066 case IFF_TAP:
1067 dev->netdev_ops = &tap_netdev_ops;
1068 /* Ethernet TAP Device */
1069 ether_setup(dev);
1070 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1071 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1072
1073 eth_hw_addr_random(dev);
1074
1075 break;
1076 }
1077
1078 dev->min_mtu = MIN_MTU;
1079 dev->max_mtu = MAX_MTU - dev->hard_header_len;
1080 }
1081
1082 /* Character device part */
1083
1084 /* Poll */
1085 static unsigned int tun_chr_poll(struct file *file, poll_table *wait)
1086 {
1087 struct tun_file *tfile = file->private_data;
1088 struct tun_struct *tun = __tun_get(tfile);
1089 struct sock *sk;
1090 unsigned int mask = 0;
1091
1092 if (!tun)
1093 return POLLERR;
1094
1095 sk = tfile->socket.sk;
1096
1097 tun_debug(KERN_INFO, tun, "tun_chr_poll\n");
1098
1099 poll_wait(file, sk_sleep(sk), wait);
1100
1101 if (!skb_array_empty(&tfile->tx_array))
1102 mask |= POLLIN | POLLRDNORM;
1103
1104 if (sock_writeable(sk) ||
1105 (!test_and_set_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
1106 sock_writeable(sk)))
1107 mask |= POLLOUT | POLLWRNORM;
1108
1109 if (tun->dev->reg_state != NETREG_REGISTERED)
1110 mask = POLLERR;
1111
1112 tun_put(tun);
1113 return mask;
1114 }
1115
1116 /* prepad is the amount to reserve at front. len is length after that.
1117 * linear is a hint as to how much to copy (usually headers). */
1118 static struct sk_buff *tun_alloc_skb(struct tun_file *tfile,
1119 size_t prepad, size_t len,
1120 size_t linear, int noblock)
1121 {
1122 struct sock *sk = tfile->socket.sk;
1123 struct sk_buff *skb;
1124 int err;
1125
1126 /* Under a page? Don't bother with paged skb. */
1127 if (prepad + len < PAGE_SIZE || !linear)
1128 linear = len;
1129
1130 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
1131 &err, 0);
1132 if (!skb)
1133 return ERR_PTR(err);
1134
1135 skb_reserve(skb, prepad);
1136 skb_put(skb, linear);
1137 skb->data_len = len - linear;
1138 skb->len += len - linear;
1139
1140 return skb;
1141 }
1142
1143 /* Get packet from user space buffer */
1144 static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
1145 void *msg_control, struct iov_iter *from,
1146 int noblock)
1147 {
1148 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
1149 struct sk_buff *skb;
1150 size_t total_len = iov_iter_count(from);
1151 size_t len = total_len, align = tun->align, linear;
1152 struct virtio_net_hdr gso = { 0 };
1153 struct tun_pcpu_stats *stats;
1154 int good_linear;
1155 int copylen;
1156 bool zerocopy = false;
1157 int err;
1158 u32 rxhash;
1159
1160 if (!(tun->dev->flags & IFF_UP))
1161 return -EIO;
1162
1163 if (!(tun->flags & IFF_NO_PI)) {
1164 if (len < sizeof(pi))
1165 return -EINVAL;
1166 len -= sizeof(pi);
1167
1168 if (!copy_from_iter_full(&pi, sizeof(pi), from))
1169 return -EFAULT;
1170 }
1171
1172 if (tun->flags & IFF_VNET_HDR) {
1173 int vnet_hdr_sz = READ_ONCE(tun->vnet_hdr_sz);
1174
1175 if (len < vnet_hdr_sz)
1176 return -EINVAL;
1177 len -= vnet_hdr_sz;
1178
1179 if (!copy_from_iter_full(&gso, sizeof(gso), from))
1180 return -EFAULT;
1181
1182 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
1183 tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2 > tun16_to_cpu(tun, gso.hdr_len))
1184 gso.hdr_len = cpu_to_tun16(tun, tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2);
1185
1186 if (tun16_to_cpu(tun, gso.hdr_len) > len)
1187 return -EINVAL;
1188 iov_iter_advance(from, vnet_hdr_sz - sizeof(gso));
1189 }
1190
1191 if ((tun->flags & TUN_TYPE_MASK) == IFF_TAP) {
1192 align += NET_IP_ALIGN;
1193 if (unlikely(len < ETH_HLEN ||
1194 (gso.hdr_len && tun16_to_cpu(tun, gso.hdr_len) < ETH_HLEN)))
1195 return -EINVAL;
1196 }
1197
1198 good_linear = SKB_MAX_HEAD(align);
1199
1200 if (msg_control) {
1201 struct iov_iter i = *from;
1202
1203 /* There are 256 bytes to be copied in skb, so there is
1204 * enough room for skb expand head in case it is used.
1205 * The rest of the buffer is mapped from userspace.
1206 */
1207 copylen = gso.hdr_len ? tun16_to_cpu(tun, gso.hdr_len) : GOODCOPY_LEN;
1208 if (copylen > good_linear)
1209 copylen = good_linear;
1210 linear = copylen;
1211 iov_iter_advance(&i, copylen);
1212 if (iov_iter_npages(&i, INT_MAX) <= MAX_SKB_FRAGS)
1213 zerocopy = true;
1214 }
1215
1216 if (!zerocopy) {
1217 copylen = len;
1218 if (tun16_to_cpu(tun, gso.hdr_len) > good_linear)
1219 linear = good_linear;
1220 else
1221 linear = tun16_to_cpu(tun, gso.hdr_len);
1222 }
1223
1224 skb = tun_alloc_skb(tfile, align, copylen, linear, noblock);
1225 if (IS_ERR(skb)) {
1226 if (PTR_ERR(skb) != -EAGAIN)
1227 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1228 return PTR_ERR(skb);
1229 }
1230
1231 if (zerocopy)
1232 err = zerocopy_sg_from_iter(skb, from);
1233 else
1234 err = skb_copy_datagram_from_iter(skb, 0, from, len);
1235
1236 if (err) {
1237 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1238 kfree_skb(skb);
1239 return -EFAULT;
1240 }
1241
1242 if (virtio_net_hdr_to_skb(skb, &gso, tun_is_little_endian(tun))) {
1243 this_cpu_inc(tun->pcpu_stats->rx_frame_errors);
1244 kfree_skb(skb);
1245 return -EINVAL;
1246 }
1247
1248 switch (tun->flags & TUN_TYPE_MASK) {
1249 case IFF_TUN:
1250 if (tun->flags & IFF_NO_PI) {
1251 switch (skb->data[0] & 0xf0) {
1252 case 0x40:
1253 pi.proto = htons(ETH_P_IP);
1254 break;
1255 case 0x60:
1256 pi.proto = htons(ETH_P_IPV6);
1257 break;
1258 default:
1259 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1260 kfree_skb(skb);
1261 return -EINVAL;
1262 }
1263 }
1264
1265 skb_reset_mac_header(skb);
1266 skb->protocol = pi.proto;
1267 skb->dev = tun->dev;
1268 break;
1269 case IFF_TAP:
1270 skb->protocol = eth_type_trans(skb, tun->dev);
1271 break;
1272 }
1273
1274 /* copy skb_ubuf_info for callback when skb has no error */
1275 if (zerocopy) {
1276 skb_shinfo(skb)->destructor_arg = msg_control;
1277 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1278 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
1279 } else if (msg_control) {
1280 struct ubuf_info *uarg = msg_control;
1281 uarg->callback(uarg, false);
1282 }
1283
1284 skb_reset_network_header(skb);
1285 skb_probe_transport_header(skb, 0);
1286
1287 rxhash = skb_get_hash(skb);
1288 #ifndef CONFIG_4KSTACKS
1289 local_bh_disable();
1290 netif_receive_skb(skb);
1291 local_bh_enable();
1292 #else
1293 netif_rx_ni(skb);
1294 #endif
1295
1296 stats = get_cpu_ptr(tun->pcpu_stats);
1297 u64_stats_update_begin(&stats->syncp);
1298 stats->rx_packets++;
1299 stats->rx_bytes += len;
1300 u64_stats_update_end(&stats->syncp);
1301 put_cpu_ptr(stats);
1302
1303 tun_flow_update(tun, rxhash, tfile);
1304 return total_len;
1305 }
1306
1307 static ssize_t tun_chr_write_iter(struct kiocb *iocb, struct iov_iter *from)
1308 {
1309 struct file *file = iocb->ki_filp;
1310 struct tun_struct *tun = tun_get(file);
1311 struct tun_file *tfile = file->private_data;
1312 ssize_t result;
1313
1314 if (!tun)
1315 return -EBADFD;
1316
1317 result = tun_get_user(tun, tfile, NULL, from, file->f_flags & O_NONBLOCK);
1318
1319 tun_put(tun);
1320 return result;
1321 }
1322
1323 /* Put packet to the user space buffer */
1324 static ssize_t tun_put_user(struct tun_struct *tun,
1325 struct tun_file *tfile,
1326 struct sk_buff *skb,
1327 struct iov_iter *iter)
1328 {
1329 struct tun_pi pi = { 0, skb->protocol };
1330 struct tun_pcpu_stats *stats;
1331 ssize_t total;
1332 int vlan_offset = 0;
1333 int vlan_hlen = 0;
1334 int vnet_hdr_sz = 0;
1335
1336 if (skb_vlan_tag_present(skb))
1337 vlan_hlen = VLAN_HLEN;
1338
1339 if (tun->flags & IFF_VNET_HDR)
1340 vnet_hdr_sz = READ_ONCE(tun->vnet_hdr_sz);
1341
1342 total = skb->len + vlan_hlen + vnet_hdr_sz;
1343
1344 if (!(tun->flags & IFF_NO_PI)) {
1345 if (iov_iter_count(iter) < sizeof(pi))
1346 return -EINVAL;
1347
1348 total += sizeof(pi);
1349 if (iov_iter_count(iter) < total) {
1350 /* Packet will be striped */
1351 pi.flags |= TUN_PKT_STRIP;
1352 }
1353
1354 if (copy_to_iter(&pi, sizeof(pi), iter) != sizeof(pi))
1355 return -EFAULT;
1356 }
1357
1358 if (vnet_hdr_sz) {
1359 struct virtio_net_hdr gso;
1360
1361 if (iov_iter_count(iter) < vnet_hdr_sz)
1362 return -EINVAL;
1363
1364 if (virtio_net_hdr_from_skb(skb, &gso,
1365 tun_is_little_endian(tun), true)) {
1366 struct skb_shared_info *sinfo = skb_shinfo(skb);
1367 pr_err("unexpected GSO type: "
1368 "0x%x, gso_size %d, hdr_len %d\n",
1369 sinfo->gso_type, tun16_to_cpu(tun, gso.gso_size),
1370 tun16_to_cpu(tun, gso.hdr_len));
1371 print_hex_dump(KERN_ERR, "tun: ",
1372 DUMP_PREFIX_NONE,
1373 16, 1, skb->head,
1374 min((int)tun16_to_cpu(tun, gso.hdr_len), 64), true);
1375 WARN_ON_ONCE(1);
1376 return -EINVAL;
1377 }
1378
1379 if (copy_to_iter(&gso, sizeof(gso), iter) != sizeof(gso))
1380 return -EFAULT;
1381
1382 iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso));
1383 }
1384
1385 if (vlan_hlen) {
1386 int ret;
1387 struct {
1388 __be16 h_vlan_proto;
1389 __be16 h_vlan_TCI;
1390 } veth;
1391
1392 veth.h_vlan_proto = skb->vlan_proto;
1393 veth.h_vlan_TCI = htons(skb_vlan_tag_get(skb));
1394
1395 vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);
1396
1397 ret = skb_copy_datagram_iter(skb, 0, iter, vlan_offset);
1398 if (ret || !iov_iter_count(iter))
1399 goto done;
1400
1401 ret = copy_to_iter(&veth, sizeof(veth), iter);
1402 if (ret != sizeof(veth) || !iov_iter_count(iter))
1403 goto done;
1404 }
1405
1406 skb_copy_datagram_iter(skb, vlan_offset, iter, skb->len - vlan_offset);
1407
1408 done:
1409 /* caller is in process context, */
1410 stats = get_cpu_ptr(tun->pcpu_stats);
1411 u64_stats_update_begin(&stats->syncp);
1412 stats->tx_packets++;
1413 stats->tx_bytes += skb->len + vlan_hlen;
1414 u64_stats_update_end(&stats->syncp);
1415 put_cpu_ptr(tun->pcpu_stats);
1416
1417 return total;
1418 }
1419
1420 static struct sk_buff *tun_ring_recv(struct tun_file *tfile, int noblock,
1421 int *err)
1422 {
1423 DECLARE_WAITQUEUE(wait, current);
1424 struct sk_buff *skb = NULL;
1425 int error = 0;
1426
1427 skb = skb_array_consume(&tfile->tx_array);
1428 if (skb)
1429 goto out;
1430 if (noblock) {
1431 error = -EAGAIN;
1432 goto out;
1433 }
1434
1435 add_wait_queue(&tfile->wq.wait, &wait);
1436 current->state = TASK_INTERRUPTIBLE;
1437
1438 while (1) {
1439 skb = skb_array_consume(&tfile->tx_array);
1440 if (skb)
1441 break;
1442 if (signal_pending(current)) {
1443 error = -ERESTARTSYS;
1444 break;
1445 }
1446 if (tfile->socket.sk->sk_shutdown & RCV_SHUTDOWN) {
1447 error = -EFAULT;
1448 break;
1449 }
1450
1451 schedule();
1452 }
1453
1454 current->state = TASK_RUNNING;
1455 remove_wait_queue(&tfile->wq.wait, &wait);
1456
1457 out:
1458 *err = error;
1459 return skb;
1460 }
1461
1462 static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
1463 struct iov_iter *to,
1464 int noblock)
1465 {
1466 struct sk_buff *skb;
1467 ssize_t ret;
1468 int err;
1469
1470 tun_debug(KERN_INFO, tun, "tun_do_read\n");
1471
1472 if (!iov_iter_count(to))
1473 return 0;
1474
1475 /* Read frames from ring */
1476 skb = tun_ring_recv(tfile, noblock, &err);
1477 if (!skb)
1478 return err;
1479
1480 ret = tun_put_user(tun, tfile, skb, to);
1481 if (unlikely(ret < 0))
1482 kfree_skb(skb);
1483 else
1484 consume_skb(skb);
1485
1486 return ret;
1487 }
1488
1489 static ssize_t tun_chr_read_iter(struct kiocb *iocb, struct iov_iter *to)
1490 {
1491 struct file *file = iocb->ki_filp;
1492 struct tun_file *tfile = file->private_data;
1493 struct tun_struct *tun = __tun_get(tfile);
1494 ssize_t len = iov_iter_count(to), ret;
1495
1496 if (!tun)
1497 return -EBADFD;
1498 ret = tun_do_read(tun, tfile, to, file->f_flags & O_NONBLOCK);
1499 ret = min_t(ssize_t, ret, len);
1500 if (ret > 0)
1501 iocb->ki_pos = ret;
1502 tun_put(tun);
1503 return ret;
1504 }
1505
1506 static void tun_free_netdev(struct net_device *dev)
1507 {
1508 struct tun_struct *tun = netdev_priv(dev);
1509
1510 BUG_ON(!(list_empty(&tun->disabled)));
1511 free_percpu(tun->pcpu_stats);
1512 tun_flow_uninit(tun);
1513 security_tun_dev_free_security(tun->security);
1514 free_netdev(dev);
1515 }
1516
1517 static void tun_setup(struct net_device *dev)
1518 {
1519 struct tun_struct *tun = netdev_priv(dev);
1520
1521 tun->owner = INVALID_UID;
1522 tun->group = INVALID_GID;
1523
1524 dev->ethtool_ops = &tun_ethtool_ops;
1525 dev->destructor = tun_free_netdev;
1526 /* We prefer our own queue length */
1527 dev->tx_queue_len = TUN_READQ_SIZE;
1528 }
1529
1530 /* Trivial set of netlink ops to allow deleting tun or tap
1531 * device with netlink.
1532 */
1533 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
1534 {
1535 return -EINVAL;
1536 }
1537
1538 static struct rtnl_link_ops tun_link_ops __read_mostly = {
1539 .kind = DRV_NAME,
1540 .priv_size = sizeof(struct tun_struct),
1541 .setup = tun_setup,
1542 .validate = tun_validate,
1543 };
1544
1545 static void tun_sock_write_space(struct sock *sk)
1546 {
1547 struct tun_file *tfile;
1548 wait_queue_head_t *wqueue;
1549
1550 if (!sock_writeable(sk))
1551 return;
1552
1553 if (!test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags))
1554 return;
1555
1556 wqueue = sk_sleep(sk);
1557 if (wqueue && waitqueue_active(wqueue))
1558 wake_up_interruptible_sync_poll(wqueue, POLLOUT |
1559 POLLWRNORM | POLLWRBAND);
1560
1561 tfile = container_of(sk, struct tun_file, sk);
1562 kill_fasync(&tfile->fasync, SIGIO, POLL_OUT);
1563 }
1564
1565 static int tun_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
1566 {
1567 int ret;
1568 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1569 struct tun_struct *tun = __tun_get(tfile);
1570
1571 if (!tun)
1572 return -EBADFD;
1573
1574 ret = tun_get_user(tun, tfile, m->msg_control, &m->msg_iter,
1575 m->msg_flags & MSG_DONTWAIT);
1576 tun_put(tun);
1577 return ret;
1578 }
1579
1580 static int tun_recvmsg(struct socket *sock, struct msghdr *m, size_t total_len,
1581 int flags)
1582 {
1583 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1584 struct tun_struct *tun = __tun_get(tfile);
1585 int ret;
1586
1587 if (!tun)
1588 return -EBADFD;
1589
1590 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC|MSG_ERRQUEUE)) {
1591 ret = -EINVAL;
1592 goto out;
1593 }
1594 if (flags & MSG_ERRQUEUE) {
1595 ret = sock_recv_errqueue(sock->sk, m, total_len,
1596 SOL_PACKET, TUN_TX_TIMESTAMP);
1597 goto out;
1598 }
1599 ret = tun_do_read(tun, tfile, &m->msg_iter, flags & MSG_DONTWAIT);
1600 if (ret > (ssize_t)total_len) {
1601 m->msg_flags |= MSG_TRUNC;
1602 ret = flags & MSG_TRUNC ? ret : total_len;
1603 }
1604 out:
1605 tun_put(tun);
1606 return ret;
1607 }
1608
1609 static int tun_peek_len(struct socket *sock)
1610 {
1611 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1612 struct tun_struct *tun;
1613 int ret = 0;
1614
1615 tun = __tun_get(tfile);
1616 if (!tun)
1617 return 0;
1618
1619 ret = skb_array_peek_len(&tfile->tx_array);
1620 tun_put(tun);
1621
1622 return ret;
1623 }
1624
1625 /* Ops structure to mimic raw sockets with tun */
1626 static const struct proto_ops tun_socket_ops = {
1627 .peek_len = tun_peek_len,
1628 .sendmsg = tun_sendmsg,
1629 .recvmsg = tun_recvmsg,
1630 };
1631
1632 static struct proto tun_proto = {
1633 .name = "tun",
1634 .owner = THIS_MODULE,
1635 .obj_size = sizeof(struct tun_file),
1636 };
1637
1638 static int tun_flags(struct tun_struct *tun)
1639 {
1640 return tun->flags & (TUN_FEATURES | IFF_PERSIST | IFF_TUN | IFF_TAP);
1641 }
1642
1643 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
1644 char *buf)
1645 {
1646 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1647 return sprintf(buf, "0x%x\n", tun_flags(tun));
1648 }
1649
1650 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
1651 char *buf)
1652 {
1653 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1654 return uid_valid(tun->owner)?
1655 sprintf(buf, "%u\n",
1656 from_kuid_munged(current_user_ns(), tun->owner)):
1657 sprintf(buf, "-1\n");
1658 }
1659
1660 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
1661 char *buf)
1662 {
1663 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1664 return gid_valid(tun->group) ?
1665 sprintf(buf, "%u\n",
1666 from_kgid_munged(current_user_ns(), tun->group)):
1667 sprintf(buf, "-1\n");
1668 }
1669
1670 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
1671 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
1672 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
1673
1674 static struct attribute *tun_dev_attrs[] = {
1675 &dev_attr_tun_flags.attr,
1676 &dev_attr_owner.attr,
1677 &dev_attr_group.attr,
1678 NULL
1679 };
1680
1681 static const struct attribute_group tun_attr_group = {
1682 .attrs = tun_dev_attrs
1683 };
1684
1685 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
1686 {
1687 struct tun_struct *tun;
1688 struct tun_file *tfile = file->private_data;
1689 struct net_device *dev;
1690 int err;
1691
1692 if (tfile->detached)
1693 return -EINVAL;
1694
1695 dev = __dev_get_by_name(net, ifr->ifr_name);
1696 if (dev) {
1697 if (ifr->ifr_flags & IFF_TUN_EXCL)
1698 return -EBUSY;
1699 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
1700 tun = netdev_priv(dev);
1701 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
1702 tun = netdev_priv(dev);
1703 else
1704 return -EINVAL;
1705
1706 if (!!(ifr->ifr_flags & IFF_MULTI_QUEUE) !=
1707 !!(tun->flags & IFF_MULTI_QUEUE))
1708 return -EINVAL;
1709
1710 if (tun_not_capable(tun))
1711 return -EPERM;
1712 err = security_tun_dev_open(tun->security);
1713 if (err < 0)
1714 return err;
1715
1716 err = tun_attach(tun, file, ifr->ifr_flags & IFF_NOFILTER);
1717 if (err < 0)
1718 return err;
1719
1720 if (tun->flags & IFF_MULTI_QUEUE &&
1721 (tun->numqueues + tun->numdisabled > 1)) {
1722 /* One or more queue has already been attached, no need
1723 * to initialize the device again.
1724 */
1725 return 0;
1726 }
1727 }
1728 else {
1729 char *name;
1730 unsigned long flags = 0;
1731 int queues = ifr->ifr_flags & IFF_MULTI_QUEUE ?
1732 MAX_TAP_QUEUES : 1;
1733
1734 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1735 return -EPERM;
1736 err = security_tun_dev_create();
1737 if (err < 0)
1738 return err;
1739
1740 /* Set dev type */
1741 if (ifr->ifr_flags & IFF_TUN) {
1742 /* TUN device */
1743 flags |= IFF_TUN;
1744 name = "tun%d";
1745 } else if (ifr->ifr_flags & IFF_TAP) {
1746 /* TAP device */
1747 flags |= IFF_TAP;
1748 name = "tap%d";
1749 } else
1750 return -EINVAL;
1751
1752 if (*ifr->ifr_name)
1753 name = ifr->ifr_name;
1754
1755 dev = alloc_netdev_mqs(sizeof(struct tun_struct), name,
1756 NET_NAME_UNKNOWN, tun_setup, queues,
1757 queues);
1758
1759 if (!dev)
1760 return -ENOMEM;
1761
1762 dev_net_set(dev, net);
1763 dev->rtnl_link_ops = &tun_link_ops;
1764 dev->ifindex = tfile->ifindex;
1765 dev->sysfs_groups[0] = &tun_attr_group;
1766
1767 tun = netdev_priv(dev);
1768 tun->dev = dev;
1769 tun->flags = flags;
1770 tun->txflt.count = 0;
1771 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
1772
1773 tun->align = NET_SKB_PAD;
1774 tun->filter_attached = false;
1775 tun->sndbuf = tfile->socket.sk->sk_sndbuf;
1776
1777 tun->pcpu_stats = netdev_alloc_pcpu_stats(struct tun_pcpu_stats);
1778 if (!tun->pcpu_stats) {
1779 err = -ENOMEM;
1780 goto err_free_dev;
1781 }
1782
1783 spin_lock_init(&tun->lock);
1784
1785 err = security_tun_dev_alloc_security(&tun->security);
1786 if (err < 0)
1787 goto err_free_stat;
1788
1789 tun_net_init(dev);
1790 tun_flow_init(tun);
1791
1792 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
1793 TUN_USER_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
1794 NETIF_F_HW_VLAN_STAG_TX;
1795 dev->features = dev->hw_features | NETIF_F_LLTX;
1796 dev->vlan_features = dev->features &
1797 ~(NETIF_F_HW_VLAN_CTAG_TX |
1798 NETIF_F_HW_VLAN_STAG_TX);
1799
1800 INIT_LIST_HEAD(&tun->disabled);
1801 err = tun_attach(tun, file, false);
1802 if (err < 0)
1803 goto err_free_flow;
1804
1805 err = register_netdevice(tun->dev);
1806 if (err < 0)
1807 goto err_detach;
1808 }
1809
1810 netif_carrier_on(tun->dev);
1811
1812 tun_debug(KERN_INFO, tun, "tun_set_iff\n");
1813
1814 tun->flags = (tun->flags & ~TUN_FEATURES) |
1815 (ifr->ifr_flags & TUN_FEATURES);
1816
1817 /* Make sure persistent devices do not get stuck in
1818 * xoff state.
1819 */
1820 if (netif_running(tun->dev))
1821 netif_tx_wake_all_queues(tun->dev);
1822
1823 strcpy(ifr->ifr_name, tun->dev->name);
1824 return 0;
1825
1826 err_detach:
1827 tun_detach_all(dev);
1828 err_free_flow:
1829 tun_flow_uninit(tun);
1830 security_tun_dev_free_security(tun->security);
1831 err_free_stat:
1832 free_percpu(tun->pcpu_stats);
1833 err_free_dev:
1834 free_netdev(dev);
1835 return err;
1836 }
1837
1838 static void tun_get_iff(struct net *net, struct tun_struct *tun,
1839 struct ifreq *ifr)
1840 {
1841 tun_debug(KERN_INFO, tun, "tun_get_iff\n");
1842
1843 strcpy(ifr->ifr_name, tun->dev->name);
1844
1845 ifr->ifr_flags = tun_flags(tun);
1846
1847 }
1848
1849 /* This is like a cut-down ethtool ops, except done via tun fd so no
1850 * privs required. */
1851 static int set_offload(struct tun_struct *tun, unsigned long arg)
1852 {
1853 netdev_features_t features = 0;
1854
1855 if (arg & TUN_F_CSUM) {
1856 features |= NETIF_F_HW_CSUM;
1857 arg &= ~TUN_F_CSUM;
1858
1859 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1860 if (arg & TUN_F_TSO_ECN) {
1861 features |= NETIF_F_TSO_ECN;
1862 arg &= ~TUN_F_TSO_ECN;
1863 }
1864 if (arg & TUN_F_TSO4)
1865 features |= NETIF_F_TSO;
1866 if (arg & TUN_F_TSO6)
1867 features |= NETIF_F_TSO6;
1868 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1869 }
1870
1871 if (arg & TUN_F_UFO) {
1872 features |= NETIF_F_UFO;
1873 arg &= ~TUN_F_UFO;
1874 }
1875 }
1876
1877 /* This gives the user a way to test for new features in future by
1878 * trying to set them. */
1879 if (arg)
1880 return -EINVAL;
1881
1882 tun->set_features = features;
1883 netdev_update_features(tun->dev);
1884
1885 return 0;
1886 }
1887
1888 static void tun_detach_filter(struct tun_struct *tun, int n)
1889 {
1890 int i;
1891 struct tun_file *tfile;
1892
1893 for (i = 0; i < n; i++) {
1894 tfile = rtnl_dereference(tun->tfiles[i]);
1895 lock_sock(tfile->socket.sk);
1896 sk_detach_filter(tfile->socket.sk);
1897 release_sock(tfile->socket.sk);
1898 }
1899
1900 tun->filter_attached = false;
1901 }
1902
1903 static int tun_attach_filter(struct tun_struct *tun)
1904 {
1905 int i, ret = 0;
1906 struct tun_file *tfile;
1907
1908 for (i = 0; i < tun->numqueues; i++) {
1909 tfile = rtnl_dereference(tun->tfiles[i]);
1910 lock_sock(tfile->socket.sk);
1911 ret = sk_attach_filter(&tun->fprog, tfile->socket.sk);
1912 release_sock(tfile->socket.sk);
1913 if (ret) {
1914 tun_detach_filter(tun, i);
1915 return ret;
1916 }
1917 }
1918
1919 tun->filter_attached = true;
1920 return ret;
1921 }
1922
1923 static void tun_set_sndbuf(struct tun_struct *tun)
1924 {
1925 struct tun_file *tfile;
1926 int i;
1927
1928 for (i = 0; i < tun->numqueues; i++) {
1929 tfile = rtnl_dereference(tun->tfiles[i]);
1930 tfile->socket.sk->sk_sndbuf = tun->sndbuf;
1931 }
1932 }
1933
1934 static int tun_set_queue(struct file *file, struct ifreq *ifr)
1935 {
1936 struct tun_file *tfile = file->private_data;
1937 struct tun_struct *tun;
1938 int ret = 0;
1939
1940 rtnl_lock();
1941
1942 if (ifr->ifr_flags & IFF_ATTACH_QUEUE) {
1943 tun = tfile->detached;
1944 if (!tun) {
1945 ret = -EINVAL;
1946 goto unlock;
1947 }
1948 ret = security_tun_dev_attach_queue(tun->security);
1949 if (ret < 0)
1950 goto unlock;
1951 ret = tun_attach(tun, file, false);
1952 } else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
1953 tun = rtnl_dereference(tfile->tun);
1954 if (!tun || !(tun->flags & IFF_MULTI_QUEUE) || tfile->detached)
1955 ret = -EINVAL;
1956 else
1957 __tun_detach(tfile, false);
1958 } else
1959 ret = -EINVAL;
1960
1961 unlock:
1962 rtnl_unlock();
1963 return ret;
1964 }
1965
1966 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
1967 unsigned long arg, int ifreq_len)
1968 {
1969 struct tun_file *tfile = file->private_data;
1970 struct tun_struct *tun;
1971 void __user* argp = (void __user*)arg;
1972 struct ifreq ifr;
1973 kuid_t owner;
1974 kgid_t group;
1975 int sndbuf;
1976 int vnet_hdr_sz;
1977 unsigned int ifindex;
1978 int le;
1979 int ret;
1980
1981 if (cmd == TUNSETIFF || cmd == TUNSETQUEUE || _IOC_TYPE(cmd) == SOCK_IOC_TYPE) {
1982 if (copy_from_user(&ifr, argp, ifreq_len))
1983 return -EFAULT;
1984 } else {
1985 memset(&ifr, 0, sizeof(ifr));
1986 }
1987 if (cmd == TUNGETFEATURES) {
1988 /* Currently this just means: "what IFF flags are valid?".
1989 * This is needed because we never checked for invalid flags on
1990 * TUNSETIFF.
1991 */
1992 return put_user(IFF_TUN | IFF_TAP | TUN_FEATURES,
1993 (unsigned int __user*)argp);
1994 } else if (cmd == TUNSETQUEUE)
1995 return tun_set_queue(file, &ifr);
1996
1997 ret = 0;
1998 rtnl_lock();
1999
2000 tun = __tun_get(tfile);
2001 if (cmd == TUNSETIFF) {
2002 ret = -EEXIST;
2003 if (tun)
2004 goto unlock;
2005
2006 ifr.ifr_name[IFNAMSIZ-1] = '\0';
2007
2008 ret = tun_set_iff(sock_net(&tfile->sk), file, &ifr);
2009
2010 if (ret)
2011 goto unlock;
2012
2013 if (copy_to_user(argp, &ifr, ifreq_len))
2014 ret = -EFAULT;
2015 goto unlock;
2016 }
2017 if (cmd == TUNSETIFINDEX) {
2018 ret = -EPERM;
2019 if (tun)
2020 goto unlock;
2021
2022 ret = -EFAULT;
2023 if (copy_from_user(&ifindex, argp, sizeof(ifindex)))
2024 goto unlock;
2025
2026 ret = 0;
2027 tfile->ifindex = ifindex;
2028 goto unlock;
2029 }
2030
2031 ret = -EBADFD;
2032 if (!tun)
2033 goto unlock;
2034
2035 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %u\n", cmd);
2036
2037 ret = 0;
2038 switch (cmd) {
2039 case TUNGETIFF:
2040 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
2041
2042 if (tfile->detached)
2043 ifr.ifr_flags |= IFF_DETACH_QUEUE;
2044 if (!tfile->socket.sk->sk_filter)
2045 ifr.ifr_flags |= IFF_NOFILTER;
2046
2047 if (copy_to_user(argp, &ifr, ifreq_len))
2048 ret = -EFAULT;
2049 break;
2050
2051 case TUNSETNOCSUM:
2052 /* Disable/Enable checksum */
2053
2054 /* [unimplemented] */
2055 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n",
2056 arg ? "disabled" : "enabled");
2057 break;
2058
2059 case TUNSETPERSIST:
2060 /* Disable/Enable persist mode. Keep an extra reference to the
2061 * module to prevent the module being unprobed.
2062 */
2063 if (arg && !(tun->flags & IFF_PERSIST)) {
2064 tun->flags |= IFF_PERSIST;
2065 __module_get(THIS_MODULE);
2066 }
2067 if (!arg && (tun->flags & IFF_PERSIST)) {
2068 tun->flags &= ~IFF_PERSIST;
2069 module_put(THIS_MODULE);
2070 }
2071
2072 tun_debug(KERN_INFO, tun, "persist %s\n",
2073 arg ? "enabled" : "disabled");
2074 break;
2075
2076 case TUNSETOWNER:
2077 /* Set owner of the device */
2078 owner = make_kuid(current_user_ns(), arg);
2079 if (!uid_valid(owner)) {
2080 ret = -EINVAL;
2081 break;
2082 }
2083 tun->owner = owner;
2084 tun_debug(KERN_INFO, tun, "owner set to %u\n",
2085 from_kuid(&init_user_ns, tun->owner));
2086 break;
2087
2088 case TUNSETGROUP:
2089 /* Set group of the device */
2090 group = make_kgid(current_user_ns(), arg);
2091 if (!gid_valid(group)) {
2092 ret = -EINVAL;
2093 break;
2094 }
2095 tun->group = group;
2096 tun_debug(KERN_INFO, tun, "group set to %u\n",
2097 from_kgid(&init_user_ns, tun->group));
2098 break;
2099
2100 case TUNSETLINK:
2101 /* Only allow setting the type when the interface is down */
2102 if (tun->dev->flags & IFF_UP) {
2103 tun_debug(KERN_INFO, tun,
2104 "Linktype set failed because interface is up\n");
2105 ret = -EBUSY;
2106 } else {
2107 tun->dev->type = (int) arg;
2108 tun_debug(KERN_INFO, tun, "linktype set to %d\n",
2109 tun->dev->type);
2110 ret = 0;
2111 }
2112 break;
2113
2114 #ifdef TUN_DEBUG
2115 case TUNSETDEBUG:
2116 tun->debug = arg;
2117 break;
2118 #endif
2119 case TUNSETOFFLOAD:
2120 ret = set_offload(tun, arg);
2121 break;
2122
2123 case TUNSETTXFILTER:
2124 /* Can be set only for TAPs */
2125 ret = -EINVAL;
2126 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2127 break;
2128 ret = update_filter(&tun->txflt, (void __user *)arg);
2129 break;
2130
2131 case SIOCGIFHWADDR:
2132 /* Get hw address */
2133 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
2134 ifr.ifr_hwaddr.sa_family = tun->dev->type;
2135 if (copy_to_user(argp, &ifr, ifreq_len))
2136 ret = -EFAULT;
2137 break;
2138
2139 case SIOCSIFHWADDR:
2140 /* Set hw address */
2141 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
2142 ifr.ifr_hwaddr.sa_data);
2143
2144 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
2145 break;
2146
2147 case TUNGETSNDBUF:
2148 sndbuf = tfile->socket.sk->sk_sndbuf;
2149 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
2150 ret = -EFAULT;
2151 break;
2152
2153 case TUNSETSNDBUF:
2154 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
2155 ret = -EFAULT;
2156 break;
2157 }
2158
2159 tun->sndbuf = sndbuf;
2160 tun_set_sndbuf(tun);
2161 break;
2162
2163 case TUNGETVNETHDRSZ:
2164 vnet_hdr_sz = tun->vnet_hdr_sz;
2165 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
2166 ret = -EFAULT;
2167 break;
2168
2169 case TUNSETVNETHDRSZ:
2170 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
2171 ret = -EFAULT;
2172 break;
2173 }
2174 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
2175 ret = -EINVAL;
2176 break;
2177 }
2178
2179 tun->vnet_hdr_sz = vnet_hdr_sz;
2180 break;
2181
2182 case TUNGETVNETLE:
2183 le = !!(tun->flags & TUN_VNET_LE);
2184 if (put_user(le, (int __user *)argp))
2185 ret = -EFAULT;
2186 break;
2187
2188 case TUNSETVNETLE:
2189 if (get_user(le, (int __user *)argp)) {
2190 ret = -EFAULT;
2191 break;
2192 }
2193 if (le)
2194 tun->flags |= TUN_VNET_LE;
2195 else
2196 tun->flags &= ~TUN_VNET_LE;
2197 break;
2198
2199 case TUNGETVNETBE:
2200 ret = tun_get_vnet_be(tun, argp);
2201 break;
2202
2203 case TUNSETVNETBE:
2204 ret = tun_set_vnet_be(tun, argp);
2205 break;
2206
2207 case TUNATTACHFILTER:
2208 /* Can be set only for TAPs */
2209 ret = -EINVAL;
2210 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2211 break;
2212 ret = -EFAULT;
2213 if (copy_from_user(&tun->fprog, argp, sizeof(tun->fprog)))
2214 break;
2215
2216 ret = tun_attach_filter(tun);
2217 break;
2218
2219 case TUNDETACHFILTER:
2220 /* Can be set only for TAPs */
2221 ret = -EINVAL;
2222 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2223 break;
2224 ret = 0;
2225 tun_detach_filter(tun, tun->numqueues);
2226 break;
2227
2228 case TUNGETFILTER:
2229 ret = -EINVAL;
2230 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2231 break;
2232 ret = -EFAULT;
2233 if (copy_to_user(argp, &tun->fprog, sizeof(tun->fprog)))
2234 break;
2235 ret = 0;
2236 break;
2237
2238 default:
2239 ret = -EINVAL;
2240 break;
2241 }
2242
2243 unlock:
2244 rtnl_unlock();
2245 if (tun)
2246 tun_put(tun);
2247 return ret;
2248 }
2249
2250 static long tun_chr_ioctl(struct file *file,
2251 unsigned int cmd, unsigned long arg)
2252 {
2253 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
2254 }
2255
2256 #ifdef CONFIG_COMPAT
2257 static long tun_chr_compat_ioctl(struct file *file,
2258 unsigned int cmd, unsigned long arg)
2259 {
2260 switch (cmd) {
2261 case TUNSETIFF:
2262 case TUNGETIFF:
2263 case TUNSETTXFILTER:
2264 case TUNGETSNDBUF:
2265 case TUNSETSNDBUF:
2266 case SIOCGIFHWADDR:
2267 case SIOCSIFHWADDR:
2268 arg = (unsigned long)compat_ptr(arg);
2269 break;
2270 default:
2271 arg = (compat_ulong_t)arg;
2272 break;
2273 }
2274
2275 /*
2276 * compat_ifreq is shorter than ifreq, so we must not access beyond
2277 * the end of that structure. All fields that are used in this
2278 * driver are compatible though, we don't need to convert the
2279 * contents.
2280 */
2281 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
2282 }
2283 #endif /* CONFIG_COMPAT */
2284
2285 static int tun_chr_fasync(int fd, struct file *file, int on)
2286 {
2287 struct tun_file *tfile = file->private_data;
2288 int ret;
2289
2290 if ((ret = fasync_helper(fd, file, on, &tfile->fasync)) < 0)
2291 goto out;
2292
2293 if (on) {
2294 __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
2295 tfile->flags |= TUN_FASYNC;
2296 } else
2297 tfile->flags &= ~TUN_FASYNC;
2298 ret = 0;
2299 out:
2300 return ret;
2301 }
2302
2303 static int tun_chr_open(struct inode *inode, struct file * file)
2304 {
2305 struct net *net = current->nsproxy->net_ns;
2306 struct tun_file *tfile;
2307
2308 DBG1(KERN_INFO, "tunX: tun_chr_open\n");
2309
2310 tfile = (struct tun_file *)sk_alloc(net, AF_UNSPEC, GFP_KERNEL,
2311 &tun_proto, 0);
2312 if (!tfile)
2313 return -ENOMEM;
2314 RCU_INIT_POINTER(tfile->tun, NULL);
2315 tfile->flags = 0;
2316 tfile->ifindex = 0;
2317
2318 init_waitqueue_head(&tfile->wq.wait);
2319 RCU_INIT_POINTER(tfile->socket.wq, &tfile->wq);
2320
2321 tfile->socket.file = file;
2322 tfile->socket.ops = &tun_socket_ops;
2323
2324 sock_init_data(&tfile->socket, &tfile->sk);
2325
2326 tfile->sk.sk_write_space = tun_sock_write_space;
2327 tfile->sk.sk_sndbuf = INT_MAX;
2328
2329 file->private_data = tfile;
2330 INIT_LIST_HEAD(&tfile->next);
2331
2332 sock_set_flag(&tfile->sk, SOCK_ZEROCOPY);
2333
2334 return 0;
2335 }
2336
2337 static int tun_chr_close(struct inode *inode, struct file *file)
2338 {
2339 struct tun_file *tfile = file->private_data;
2340
2341 tun_detach(tfile, true);
2342
2343 return 0;
2344 }
2345
2346 #ifdef CONFIG_PROC_FS
2347 static void tun_chr_show_fdinfo(struct seq_file *m, struct file *f)
2348 {
2349 struct tun_struct *tun;
2350 struct ifreq ifr;
2351
2352 memset(&ifr, 0, sizeof(ifr));
2353
2354 rtnl_lock();
2355 tun = tun_get(f);
2356 if (tun)
2357 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
2358 rtnl_unlock();
2359
2360 if (tun)
2361 tun_put(tun);
2362
2363 seq_printf(m, "iff:\t%s\n", ifr.ifr_name);
2364 }
2365 #endif
2366
2367 static const struct file_operations tun_fops = {
2368 .owner = THIS_MODULE,
2369 .llseek = no_llseek,
2370 .read_iter = tun_chr_read_iter,
2371 .write_iter = tun_chr_write_iter,
2372 .poll = tun_chr_poll,
2373 .unlocked_ioctl = tun_chr_ioctl,
2374 #ifdef CONFIG_COMPAT
2375 .compat_ioctl = tun_chr_compat_ioctl,
2376 #endif
2377 .open = tun_chr_open,
2378 .release = tun_chr_close,
2379 .fasync = tun_chr_fasync,
2380 #ifdef CONFIG_PROC_FS
2381 .show_fdinfo = tun_chr_show_fdinfo,
2382 #endif
2383 };
2384
2385 static struct miscdevice tun_miscdev = {
2386 .minor = TUN_MINOR,
2387 .name = "tun",
2388 .nodename = "net/tun",
2389 .fops = &tun_fops,
2390 };
2391
2392 /* ethtool interface */
2393
2394 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
2395 {
2396 cmd->supported = 0;
2397 cmd->advertising = 0;
2398 ethtool_cmd_speed_set(cmd, SPEED_10);
2399 cmd->duplex = DUPLEX_FULL;
2400 cmd->port = PORT_TP;
2401 cmd->phy_address = 0;
2402 cmd->transceiver = XCVR_INTERNAL;
2403 cmd->autoneg = AUTONEG_DISABLE;
2404 cmd->maxtxpkt = 0;
2405 cmd->maxrxpkt = 0;
2406 return 0;
2407 }
2408
2409 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
2410 {
2411 struct tun_struct *tun = netdev_priv(dev);
2412
2413 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
2414 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
2415
2416 switch (tun->flags & TUN_TYPE_MASK) {
2417 case IFF_TUN:
2418 strlcpy(info->bus_info, "tun", sizeof(info->bus_info));
2419 break;
2420 case IFF_TAP:
2421 strlcpy(info->bus_info, "tap", sizeof(info->bus_info));
2422 break;
2423 }
2424 }
2425
2426 static u32 tun_get_msglevel(struct net_device *dev)
2427 {
2428 #ifdef TUN_DEBUG
2429 struct tun_struct *tun = netdev_priv(dev);
2430 return tun->debug;
2431 #else
2432 return -EOPNOTSUPP;
2433 #endif
2434 }
2435
2436 static void tun_set_msglevel(struct net_device *dev, u32 value)
2437 {
2438 #ifdef TUN_DEBUG
2439 struct tun_struct *tun = netdev_priv(dev);
2440 tun->debug = value;
2441 #endif
2442 }
2443
2444 static const struct ethtool_ops tun_ethtool_ops = {
2445 .get_settings = tun_get_settings,
2446 .get_drvinfo = tun_get_drvinfo,
2447 .get_msglevel = tun_get_msglevel,
2448 .set_msglevel = tun_set_msglevel,
2449 .get_link = ethtool_op_get_link,
2450 .get_ts_info = ethtool_op_get_ts_info,
2451 };
2452
2453 static int tun_queue_resize(struct tun_struct *tun)
2454 {
2455 struct net_device *dev = tun->dev;
2456 struct tun_file *tfile;
2457 struct skb_array **arrays;
2458 int n = tun->numqueues + tun->numdisabled;
2459 int ret, i;
2460
2461 arrays = kmalloc(sizeof *arrays * n, GFP_KERNEL);
2462 if (!arrays)
2463 return -ENOMEM;
2464
2465 for (i = 0; i < tun->numqueues; i++) {
2466 tfile = rtnl_dereference(tun->tfiles[i]);
2467 arrays[i] = &tfile->tx_array;
2468 }
2469 list_for_each_entry(tfile, &tun->disabled, next)
2470 arrays[i++] = &tfile->tx_array;
2471
2472 ret = skb_array_resize_multiple(arrays, n,
2473 dev->tx_queue_len, GFP_KERNEL);
2474
2475 kfree(arrays);
2476 return ret;
2477 }
2478
2479 static int tun_device_event(struct notifier_block *unused,
2480 unsigned long event, void *ptr)
2481 {
2482 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
2483 struct tun_struct *tun = netdev_priv(dev);
2484
2485 if (dev->rtnl_link_ops != &tun_link_ops)
2486 return NOTIFY_DONE;
2487
2488 switch (event) {
2489 case NETDEV_CHANGE_TX_QUEUE_LEN:
2490 if (tun_queue_resize(tun))
2491 return NOTIFY_BAD;
2492 break;
2493 default:
2494 break;
2495 }
2496
2497 return NOTIFY_DONE;
2498 }
2499
2500 static struct notifier_block tun_notifier_block __read_mostly = {
2501 .notifier_call = tun_device_event,
2502 };
2503
2504 static int __init tun_init(void)
2505 {
2506 int ret = 0;
2507
2508 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
2509 pr_info("%s\n", DRV_COPYRIGHT);
2510
2511 ret = rtnl_link_register(&tun_link_ops);
2512 if (ret) {
2513 pr_err("Can't register link_ops\n");
2514 goto err_linkops;
2515 }
2516
2517 ret = misc_register(&tun_miscdev);
2518 if (ret) {
2519 pr_err("Can't register misc device %d\n", TUN_MINOR);
2520 goto err_misc;
2521 }
2522
2523 register_netdevice_notifier(&tun_notifier_block);
2524 return 0;
2525 err_misc:
2526 rtnl_link_unregister(&tun_link_ops);
2527 err_linkops:
2528 return ret;
2529 }
2530
2531 static void tun_cleanup(void)
2532 {
2533 misc_deregister(&tun_miscdev);
2534 rtnl_link_unregister(&tun_link_ops);
2535 unregister_netdevice_notifier(&tun_notifier_block);
2536 }
2537
2538 /* Get an underlying socket object from tun file. Returns error unless file is
2539 * attached to a device. The returned object works like a packet socket, it
2540 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
2541 * holding a reference to the file for as long as the socket is in use. */
2542 struct socket *tun_get_socket(struct file *file)
2543 {
2544 struct tun_file *tfile;
2545 if (file->f_op != &tun_fops)
2546 return ERR_PTR(-EINVAL);
2547 tfile = file->private_data;
2548 if (!tfile)
2549 return ERR_PTR(-EBADFD);
2550 return &tfile->socket;
2551 }
2552 EXPORT_SYMBOL_GPL(tun_get_socket);
2553
2554 module_init(tun_init);
2555 module_exit(tun_cleanup);
2556 MODULE_DESCRIPTION(DRV_DESCRIPTION);
2557 MODULE_AUTHOR(DRV_COPYRIGHT);
2558 MODULE_LICENSE("GPL");
2559 MODULE_ALIAS_MISCDEV(TUN_MINOR);
2560 MODULE_ALIAS("devname:net/tun");
Linux with added FPC-III support