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powerpc/mm/4k: don't allocate larger pmd page table for 4k
[linux/fpc-iii.git] / drivers / net / tun.c
blobcd8e02c94be0e514f226b8109e59e5ec29dad7de
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 if (len < tun->vnet_hdr_sz)
1174 return -EINVAL;
1175 len -= tun->vnet_hdr_sz;
1176
1177 if (!copy_from_iter_full(&gso, sizeof(gso), from))
1178 return -EFAULT;
1179
1180 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
1181 tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2 > tun16_to_cpu(tun, gso.hdr_len))
1182 gso.hdr_len = cpu_to_tun16(tun, tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2);
1183
1184 if (tun16_to_cpu(tun, gso.hdr_len) > len)
1185 return -EINVAL;
1186 iov_iter_advance(from, tun->vnet_hdr_sz - sizeof(gso));
1187 }
1188
1189 if ((tun->flags & TUN_TYPE_MASK) == IFF_TAP) {
1190 align += NET_IP_ALIGN;
1191 if (unlikely(len < ETH_HLEN ||
1192 (gso.hdr_len && tun16_to_cpu(tun, gso.hdr_len) < ETH_HLEN)))
1193 return -EINVAL;
1194 }
1195
1196 good_linear = SKB_MAX_HEAD(align);
1197
1198 if (msg_control) {
1199 struct iov_iter i = *from;
1200
1201 /* There are 256 bytes to be copied in skb, so there is
1202 * enough room for skb expand head in case it is used.
1203 * The rest of the buffer is mapped from userspace.
1204 */
1205 copylen = gso.hdr_len ? tun16_to_cpu(tun, gso.hdr_len) : GOODCOPY_LEN;
1206 if (copylen > good_linear)
1207 copylen = good_linear;
1208 linear = copylen;
1209 iov_iter_advance(&i, copylen);
1210 if (iov_iter_npages(&i, INT_MAX) <= MAX_SKB_FRAGS)
1211 zerocopy = true;
1212 }
1213
1214 if (!zerocopy) {
1215 copylen = len;
1216 if (tun16_to_cpu(tun, gso.hdr_len) > good_linear)
1217 linear = good_linear;
1218 else
1219 linear = tun16_to_cpu(tun, gso.hdr_len);
1220 }
1221
1222 skb = tun_alloc_skb(tfile, align, copylen, linear, noblock);
1223 if (IS_ERR(skb)) {
1224 if (PTR_ERR(skb) != -EAGAIN)
1225 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1226 return PTR_ERR(skb);
1227 }
1228
1229 if (zerocopy)
1230 err = zerocopy_sg_from_iter(skb, from);
1231 else
1232 err = skb_copy_datagram_from_iter(skb, 0, from, len);
1233
1234 if (err) {
1235 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1236 kfree_skb(skb);
1237 return -EFAULT;
1238 }
1239
1240 if (virtio_net_hdr_to_skb(skb, &gso, tun_is_little_endian(tun))) {
1241 this_cpu_inc(tun->pcpu_stats->rx_frame_errors);
1242 kfree_skb(skb);
1243 return -EINVAL;
1244 }
1245
1246 switch (tun->flags & TUN_TYPE_MASK) {
1247 case IFF_TUN:
1248 if (tun->flags & IFF_NO_PI) {
1249 switch (skb->data[0] & 0xf0) {
1250 case 0x40:
1251 pi.proto = htons(ETH_P_IP);
1252 break;
1253 case 0x60:
1254 pi.proto = htons(ETH_P_IPV6);
1255 break;
1256 default:
1257 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1258 kfree_skb(skb);
1259 return -EINVAL;
1260 }
1261 }
1262
1263 skb_reset_mac_header(skb);
1264 skb->protocol = pi.proto;
1265 skb->dev = tun->dev;
1266 break;
1267 case IFF_TAP:
1268 skb->protocol = eth_type_trans(skb, tun->dev);
1269 break;
1270 }
1271
1272 /* copy skb_ubuf_info for callback when skb has no error */
1273 if (zerocopy) {
1274 skb_shinfo(skb)->destructor_arg = msg_control;
1275 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1276 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
1277 } else if (msg_control) {
1278 struct ubuf_info *uarg = msg_control;
1279 uarg->callback(uarg, false);
1280 }
1281
1282 skb_reset_network_header(skb);
1283 skb_probe_transport_header(skb, 0);
1284
1285 rxhash = skb_get_hash(skb);
1286 #ifndef CONFIG_4KSTACKS
1287 local_bh_disable();
1288 netif_receive_skb(skb);
1289 local_bh_enable();
1290 #else
1291 netif_rx_ni(skb);
1292 #endif
1293
1294 stats = get_cpu_ptr(tun->pcpu_stats);
1295 u64_stats_update_begin(&stats->syncp);
1296 stats->rx_packets++;
1297 stats->rx_bytes += len;
1298 u64_stats_update_end(&stats->syncp);
1299 put_cpu_ptr(stats);
1300
1301 tun_flow_update(tun, rxhash, tfile);
1302 return total_len;
1303 }
1304
1305 static ssize_t tun_chr_write_iter(struct kiocb *iocb, struct iov_iter *from)
1306 {
1307 struct file *file = iocb->ki_filp;
1308 struct tun_struct *tun = tun_get(file);
1309 struct tun_file *tfile = file->private_data;
1310 ssize_t result;
1311
1312 if (!tun)
1313 return -EBADFD;
1314
1315 result = tun_get_user(tun, tfile, NULL, from, file->f_flags & O_NONBLOCK);
1316
1317 tun_put(tun);
1318 return result;
1319 }
1320
1321 /* Put packet to the user space buffer */
1322 static ssize_t tun_put_user(struct tun_struct *tun,
1323 struct tun_file *tfile,
1324 struct sk_buff *skb,
1325 struct iov_iter *iter)
1326 {
1327 struct tun_pi pi = { 0, skb->protocol };
1328 struct tun_pcpu_stats *stats;
1329 ssize_t total;
1330 int vlan_offset = 0;
1331 int vlan_hlen = 0;
1332 int vnet_hdr_sz = 0;
1333
1334 if (skb_vlan_tag_present(skb))
1335 vlan_hlen = VLAN_HLEN;
1336
1337 if (tun->flags & IFF_VNET_HDR)
1338 vnet_hdr_sz = tun->vnet_hdr_sz;
1339
1340 total = skb->len + vlan_hlen + vnet_hdr_sz;
1341
1342 if (!(tun->flags & IFF_NO_PI)) {
1343 if (iov_iter_count(iter) < sizeof(pi))
1344 return -EINVAL;
1345
1346 total += sizeof(pi);
1347 if (iov_iter_count(iter) < total) {
1348 /* Packet will be striped */
1349 pi.flags |= TUN_PKT_STRIP;
1350 }
1351
1352 if (copy_to_iter(&pi, sizeof(pi), iter) != sizeof(pi))
1353 return -EFAULT;
1354 }
1355
1356 if (vnet_hdr_sz) {
1357 struct virtio_net_hdr gso;
1358
1359 if (iov_iter_count(iter) < vnet_hdr_sz)
1360 return -EINVAL;
1361
1362 if (virtio_net_hdr_from_skb(skb, &gso,
1363 tun_is_little_endian(tun))) {
1364 struct skb_shared_info *sinfo = skb_shinfo(skb);
1365 pr_err("unexpected GSO type: "
1366 "0x%x, gso_size %d, hdr_len %d\n",
1367 sinfo->gso_type, tun16_to_cpu(tun, gso.gso_size),
1368 tun16_to_cpu(tun, gso.hdr_len));
1369 print_hex_dump(KERN_ERR, "tun: ",
1370 DUMP_PREFIX_NONE,
1371 16, 1, skb->head,
1372 min((int)tun16_to_cpu(tun, gso.hdr_len), 64), true);
1373 WARN_ON_ONCE(1);
1374 return -EINVAL;
1375 }
1376
1377 if (copy_to_iter(&gso, sizeof(gso), iter) != sizeof(gso))
1378 return -EFAULT;
1379
1380 iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso));
1381 }
1382
1383 if (vlan_hlen) {
1384 int ret;
1385 struct {
1386 __be16 h_vlan_proto;
1387 __be16 h_vlan_TCI;
1388 } veth;
1389
1390 veth.h_vlan_proto = skb->vlan_proto;
1391 veth.h_vlan_TCI = htons(skb_vlan_tag_get(skb));
1392
1393 vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);
1394
1395 ret = skb_copy_datagram_iter(skb, 0, iter, vlan_offset);
1396 if (ret || !iov_iter_count(iter))
1397 goto done;
1398
1399 ret = copy_to_iter(&veth, sizeof(veth), iter);
1400 if (ret != sizeof(veth) || !iov_iter_count(iter))
1401 goto done;
1402 }
1403
1404 skb_copy_datagram_iter(skb, vlan_offset, iter, skb->len - vlan_offset);
1405
1406 done:
1407 /* caller is in process context, */
1408 stats = get_cpu_ptr(tun->pcpu_stats);
1409 u64_stats_update_begin(&stats->syncp);
1410 stats->tx_packets++;
1411 stats->tx_bytes += skb->len + vlan_hlen;
1412 u64_stats_update_end(&stats->syncp);
1413 put_cpu_ptr(tun->pcpu_stats);
1414
1415 return total;
1416 }
1417
1418 static struct sk_buff *tun_ring_recv(struct tun_file *tfile, int noblock,
1419 int *err)
1420 {
1421 DECLARE_WAITQUEUE(wait, current);
1422 struct sk_buff *skb = NULL;
1423 int error = 0;
1424
1425 skb = skb_array_consume(&tfile->tx_array);
1426 if (skb)
1427 goto out;
1428 if (noblock) {
1429 error = -EAGAIN;
1430 goto out;
1431 }
1432
1433 add_wait_queue(&tfile->wq.wait, &wait);
1434 current->state = TASK_INTERRUPTIBLE;
1435
1436 while (1) {
1437 skb = skb_array_consume(&tfile->tx_array);
1438 if (skb)
1439 break;
1440 if (signal_pending(current)) {
1441 error = -ERESTARTSYS;
1442 break;
1443 }
1444 if (tfile->socket.sk->sk_shutdown & RCV_SHUTDOWN) {
1445 error = -EFAULT;
1446 break;
1447 }
1448
1449 schedule();
1450 }
1451
1452 current->state = TASK_RUNNING;
1453 remove_wait_queue(&tfile->wq.wait, &wait);
1454
1455 out:
1456 *err = error;
1457 return skb;
1458 }
1459
1460 static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
1461 struct iov_iter *to,
1462 int noblock)
1463 {
1464 struct sk_buff *skb;
1465 ssize_t ret;
1466 int err;
1467
1468 tun_debug(KERN_INFO, tun, "tun_do_read\n");
1469
1470 if (!iov_iter_count(to))
1471 return 0;
1472
1473 /* Read frames from ring */
1474 skb = tun_ring_recv(tfile, noblock, &err);
1475 if (!skb)
1476 return err;
1477
1478 ret = tun_put_user(tun, tfile, skb, to);
1479 if (unlikely(ret < 0))
1480 kfree_skb(skb);
1481 else
1482 consume_skb(skb);
1483
1484 return ret;
1485 }
1486
1487 static ssize_t tun_chr_read_iter(struct kiocb *iocb, struct iov_iter *to)
1488 {
1489 struct file *file = iocb->ki_filp;
1490 struct tun_file *tfile = file->private_data;
1491 struct tun_struct *tun = __tun_get(tfile);
1492 ssize_t len = iov_iter_count(to), ret;
1493
1494 if (!tun)
1495 return -EBADFD;
1496 ret = tun_do_read(tun, tfile, to, file->f_flags & O_NONBLOCK);
1497 ret = min_t(ssize_t, ret, len);
1498 if (ret > 0)
1499 iocb->ki_pos = ret;
1500 tun_put(tun);
1501 return ret;
1502 }
1503
1504 static void tun_free_netdev(struct net_device *dev)
1505 {
1506 struct tun_struct *tun = netdev_priv(dev);
1507
1508 BUG_ON(!(list_empty(&tun->disabled)));
1509 free_percpu(tun->pcpu_stats);
1510 tun_flow_uninit(tun);
1511 security_tun_dev_free_security(tun->security);
1512 free_netdev(dev);
1513 }
1514
1515 static void tun_setup(struct net_device *dev)
1516 {
1517 struct tun_struct *tun = netdev_priv(dev);
1518
1519 tun->owner = INVALID_UID;
1520 tun->group = INVALID_GID;
1521
1522 dev->ethtool_ops = &tun_ethtool_ops;
1523 dev->destructor = tun_free_netdev;
1524 /* We prefer our own queue length */
1525 dev->tx_queue_len = TUN_READQ_SIZE;
1526 }
1527
1528 /* Trivial set of netlink ops to allow deleting tun or tap
1529 * device with netlink.
1530 */
1531 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
1532 {
1533 return -EINVAL;
1534 }
1535
1536 static struct rtnl_link_ops tun_link_ops __read_mostly = {
1537 .kind = DRV_NAME,
1538 .priv_size = sizeof(struct tun_struct),
1539 .setup = tun_setup,
1540 .validate = tun_validate,
1541 };
1542
1543 static void tun_sock_write_space(struct sock *sk)
1544 {
1545 struct tun_file *tfile;
1546 wait_queue_head_t *wqueue;
1547
1548 if (!sock_writeable(sk))
1549 return;
1550
1551 if (!test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags))
1552 return;
1553
1554 wqueue = sk_sleep(sk);
1555 if (wqueue && waitqueue_active(wqueue))
1556 wake_up_interruptible_sync_poll(wqueue, POLLOUT |
1557 POLLWRNORM | POLLWRBAND);
1558
1559 tfile = container_of(sk, struct tun_file, sk);
1560 kill_fasync(&tfile->fasync, SIGIO, POLL_OUT);
1561 }
1562
1563 static int tun_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
1564 {
1565 int ret;
1566 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1567 struct tun_struct *tun = __tun_get(tfile);
1568
1569 if (!tun)
1570 return -EBADFD;
1571
1572 ret = tun_get_user(tun, tfile, m->msg_control, &m->msg_iter,
1573 m->msg_flags & MSG_DONTWAIT);
1574 tun_put(tun);
1575 return ret;
1576 }
1577
1578 static int tun_recvmsg(struct socket *sock, struct msghdr *m, size_t total_len,
1579 int flags)
1580 {
1581 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1582 struct tun_struct *tun = __tun_get(tfile);
1583 int ret;
1584
1585 if (!tun)
1586 return -EBADFD;
1587
1588 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC|MSG_ERRQUEUE)) {
1589 ret = -EINVAL;
1590 goto out;
1591 }
1592 if (flags & MSG_ERRQUEUE) {
1593 ret = sock_recv_errqueue(sock->sk, m, total_len,
1594 SOL_PACKET, TUN_TX_TIMESTAMP);
1595 goto out;
1596 }
1597 ret = tun_do_read(tun, tfile, &m->msg_iter, flags & MSG_DONTWAIT);
1598 if (ret > (ssize_t)total_len) {
1599 m->msg_flags |= MSG_TRUNC;
1600 ret = flags & MSG_TRUNC ? ret : total_len;
1601 }
1602 out:
1603 tun_put(tun);
1604 return ret;
1605 }
1606
1607 static int tun_peek_len(struct socket *sock)
1608 {
1609 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1610 struct tun_struct *tun;
1611 int ret = 0;
1612
1613 tun = __tun_get(tfile);
1614 if (!tun)
1615 return 0;
1616
1617 ret = skb_array_peek_len(&tfile->tx_array);
1618 tun_put(tun);
1619
1620 return ret;
1621 }
1622
1623 /* Ops structure to mimic raw sockets with tun */
1624 static const struct proto_ops tun_socket_ops = {
1625 .peek_len = tun_peek_len,
1626 .sendmsg = tun_sendmsg,
1627 .recvmsg = tun_recvmsg,
1628 };
1629
1630 static struct proto tun_proto = {
1631 .name = "tun",
1632 .owner = THIS_MODULE,
1633 .obj_size = sizeof(struct tun_file),
1634 };
1635
1636 static int tun_flags(struct tun_struct *tun)
1637 {
1638 return tun->flags & (TUN_FEATURES | IFF_PERSIST | IFF_TUN | IFF_TAP);
1639 }
1640
1641 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
1642 char *buf)
1643 {
1644 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1645 return sprintf(buf, "0x%x\n", tun_flags(tun));
1646 }
1647
1648 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
1649 char *buf)
1650 {
1651 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1652 return uid_valid(tun->owner)?
1653 sprintf(buf, "%u\n",
1654 from_kuid_munged(current_user_ns(), tun->owner)):
1655 sprintf(buf, "-1\n");
1656 }
1657
1658 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
1659 char *buf)
1660 {
1661 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1662 return gid_valid(tun->group) ?
1663 sprintf(buf, "%u\n",
1664 from_kgid_munged(current_user_ns(), tun->group)):
1665 sprintf(buf, "-1\n");
1666 }
1667
1668 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
1669 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
1670 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
1671
1672 static struct attribute *tun_dev_attrs[] = {
1673 &dev_attr_tun_flags.attr,
1674 &dev_attr_owner.attr,
1675 &dev_attr_group.attr,
1676 NULL
1677 };
1678
1679 static const struct attribute_group tun_attr_group = {
1680 .attrs = tun_dev_attrs
1681 };
1682
1683 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
1684 {
1685 struct tun_struct *tun;
1686 struct tun_file *tfile = file->private_data;
1687 struct net_device *dev;
1688 int err;
1689
1690 if (tfile->detached)
1691 return -EINVAL;
1692
1693 dev = __dev_get_by_name(net, ifr->ifr_name);
1694 if (dev) {
1695 if (ifr->ifr_flags & IFF_TUN_EXCL)
1696 return -EBUSY;
1697 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
1698 tun = netdev_priv(dev);
1699 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
1700 tun = netdev_priv(dev);
1701 else
1702 return -EINVAL;
1703
1704 if (!!(ifr->ifr_flags & IFF_MULTI_QUEUE) !=
1705 !!(tun->flags & IFF_MULTI_QUEUE))
1706 return -EINVAL;
1707
1708 if (tun_not_capable(tun))
1709 return -EPERM;
1710 err = security_tun_dev_open(tun->security);
1711 if (err < 0)
1712 return err;
1713
1714 err = tun_attach(tun, file, ifr->ifr_flags & IFF_NOFILTER);
1715 if (err < 0)
1716 return err;
1717
1718 if (tun->flags & IFF_MULTI_QUEUE &&
1719 (tun->numqueues + tun->numdisabled > 1)) {
1720 /* One or more queue has already been attached, no need
1721 * to initialize the device again.
1722 */
1723 return 0;
1724 }
1725 }
1726 else {
1727 char *name;
1728 unsigned long flags = 0;
1729 int queues = ifr->ifr_flags & IFF_MULTI_QUEUE ?
1730 MAX_TAP_QUEUES : 1;
1731
1732 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1733 return -EPERM;
1734 err = security_tun_dev_create();
1735 if (err < 0)
1736 return err;
1737
1738 /* Set dev type */
1739 if (ifr->ifr_flags & IFF_TUN) {
1740 /* TUN device */
1741 flags |= IFF_TUN;
1742 name = "tun%d";
1743 } else if (ifr->ifr_flags & IFF_TAP) {
1744 /* TAP device */
1745 flags |= IFF_TAP;
1746 name = "tap%d";
1747 } else
1748 return -EINVAL;
1749
1750 if (*ifr->ifr_name)
1751 name = ifr->ifr_name;
1752
1753 dev = alloc_netdev_mqs(sizeof(struct tun_struct), name,
1754 NET_NAME_UNKNOWN, tun_setup, queues,
1755 queues);
1756
1757 if (!dev)
1758 return -ENOMEM;
1759
1760 dev_net_set(dev, net);
1761 dev->rtnl_link_ops = &tun_link_ops;
1762 dev->ifindex = tfile->ifindex;
1763 dev->sysfs_groups[0] = &tun_attr_group;
1764
1765 tun = netdev_priv(dev);
1766 tun->dev = dev;
1767 tun->flags = flags;
1768 tun->txflt.count = 0;
1769 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
1770
1771 tun->align = NET_SKB_PAD;
1772 tun->filter_attached = false;
1773 tun->sndbuf = tfile->socket.sk->sk_sndbuf;
1774
1775 tun->pcpu_stats = netdev_alloc_pcpu_stats(struct tun_pcpu_stats);
1776 if (!tun->pcpu_stats) {
1777 err = -ENOMEM;
1778 goto err_free_dev;
1779 }
1780
1781 spin_lock_init(&tun->lock);
1782
1783 err = security_tun_dev_alloc_security(&tun->security);
1784 if (err < 0)
1785 goto err_free_stat;
1786
1787 tun_net_init(dev);
1788 tun_flow_init(tun);
1789
1790 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
1791 TUN_USER_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
1792 NETIF_F_HW_VLAN_STAG_TX;
1793 dev->features = dev->hw_features | NETIF_F_LLTX;
1794 dev->vlan_features = dev->features &
1795 ~(NETIF_F_HW_VLAN_CTAG_TX |
1796 NETIF_F_HW_VLAN_STAG_TX);
1797
1798 INIT_LIST_HEAD(&tun->disabled);
1799 err = tun_attach(tun, file, false);
1800 if (err < 0)
1801 goto err_free_flow;
1802
1803 err = register_netdevice(tun->dev);
1804 if (err < 0)
1805 goto err_detach;
1806 }
1807
1808 netif_carrier_on(tun->dev);
1809
1810 tun_debug(KERN_INFO, tun, "tun_set_iff\n");
1811
1812 tun->flags = (tun->flags & ~TUN_FEATURES) |
1813 (ifr->ifr_flags & TUN_FEATURES);
1814
1815 /* Make sure persistent devices do not get stuck in
1816 * xoff state.
1817 */
1818 if (netif_running(tun->dev))
1819 netif_tx_wake_all_queues(tun->dev);
1820
1821 strcpy(ifr->ifr_name, tun->dev->name);
1822 return 0;
1823
1824 err_detach:
1825 tun_detach_all(dev);
1826 err_free_flow:
1827 tun_flow_uninit(tun);
1828 security_tun_dev_free_security(tun->security);
1829 err_free_stat:
1830 free_percpu(tun->pcpu_stats);
1831 err_free_dev:
1832 free_netdev(dev);
1833 return err;
1834 }
1835
1836 static void tun_get_iff(struct net *net, struct tun_struct *tun,
1837 struct ifreq *ifr)
1838 {
1839 tun_debug(KERN_INFO, tun, "tun_get_iff\n");
1840
1841 strcpy(ifr->ifr_name, tun->dev->name);
1842
1843 ifr->ifr_flags = tun_flags(tun);
1844
1845 }
1846
1847 /* This is like a cut-down ethtool ops, except done via tun fd so no
1848 * privs required. */
1849 static int set_offload(struct tun_struct *tun, unsigned long arg)
1850 {
1851 netdev_features_t features = 0;
1852
1853 if (arg & TUN_F_CSUM) {
1854 features |= NETIF_F_HW_CSUM;
1855 arg &= ~TUN_F_CSUM;
1856
1857 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1858 if (arg & TUN_F_TSO_ECN) {
1859 features |= NETIF_F_TSO_ECN;
1860 arg &= ~TUN_F_TSO_ECN;
1861 }
1862 if (arg & TUN_F_TSO4)
1863 features |= NETIF_F_TSO;
1864 if (arg & TUN_F_TSO6)
1865 features |= NETIF_F_TSO6;
1866 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1867 }
1868
1869 if (arg & TUN_F_UFO) {
1870 features |= NETIF_F_UFO;
1871 arg &= ~TUN_F_UFO;
1872 }
1873 }
1874
1875 /* This gives the user a way to test for new features in future by
1876 * trying to set them. */
1877 if (arg)
1878 return -EINVAL;
1879
1880 tun->set_features = features;
1881 netdev_update_features(tun->dev);
1882
1883 return 0;
1884 }
1885
1886 static void tun_detach_filter(struct tun_struct *tun, int n)
1887 {
1888 int i;
1889 struct tun_file *tfile;
1890
1891 for (i = 0; i < n; i++) {
1892 tfile = rtnl_dereference(tun->tfiles[i]);
1893 lock_sock(tfile->socket.sk);
1894 sk_detach_filter(tfile->socket.sk);
1895 release_sock(tfile->socket.sk);
1896 }
1897
1898 tun->filter_attached = false;
1899 }
1900
1901 static int tun_attach_filter(struct tun_struct *tun)
1902 {
1903 int i, ret = 0;
1904 struct tun_file *tfile;
1905
1906 for (i = 0; i < tun->numqueues; i++) {
1907 tfile = rtnl_dereference(tun->tfiles[i]);
1908 lock_sock(tfile->socket.sk);
1909 ret = sk_attach_filter(&tun->fprog, tfile->socket.sk);
1910 release_sock(tfile->socket.sk);
1911 if (ret) {
1912 tun_detach_filter(tun, i);
1913 return ret;
1914 }
1915 }
1916
1917 tun->filter_attached = true;
1918 return ret;
1919 }
1920
1921 static void tun_set_sndbuf(struct tun_struct *tun)
1922 {
1923 struct tun_file *tfile;
1924 int i;
1925
1926 for (i = 0; i < tun->numqueues; i++) {
1927 tfile = rtnl_dereference(tun->tfiles[i]);
1928 tfile->socket.sk->sk_sndbuf = tun->sndbuf;
1929 }
1930 }
1931
1932 static int tun_set_queue(struct file *file, struct ifreq *ifr)
1933 {
1934 struct tun_file *tfile = file->private_data;
1935 struct tun_struct *tun;
1936 int ret = 0;
1937
1938 rtnl_lock();
1939
1940 if (ifr->ifr_flags & IFF_ATTACH_QUEUE) {
1941 tun = tfile->detached;
1942 if (!tun) {
1943 ret = -EINVAL;
1944 goto unlock;
1945 }
1946 ret = security_tun_dev_attach_queue(tun->security);
1947 if (ret < 0)
1948 goto unlock;
1949 ret = tun_attach(tun, file, false);
1950 } else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
1951 tun = rtnl_dereference(tfile->tun);
1952 if (!tun || !(tun->flags & IFF_MULTI_QUEUE) || tfile->detached)
1953 ret = -EINVAL;
1954 else
1955 __tun_detach(tfile, false);
1956 } else
1957 ret = -EINVAL;
1958
1959 unlock:
1960 rtnl_unlock();
1961 return ret;
1962 }
1963
1964 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
1965 unsigned long arg, int ifreq_len)
1966 {
1967 struct tun_file *tfile = file->private_data;
1968 struct tun_struct *tun;
1969 void __user* argp = (void __user*)arg;
1970 struct ifreq ifr;
1971 kuid_t owner;
1972 kgid_t group;
1973 int sndbuf;
1974 int vnet_hdr_sz;
1975 unsigned int ifindex;
1976 int le;
1977 int ret;
1978
1979 if (cmd == TUNSETIFF || cmd == TUNSETQUEUE || _IOC_TYPE(cmd) == SOCK_IOC_TYPE) {
1980 if (copy_from_user(&ifr, argp, ifreq_len))
1981 return -EFAULT;
1982 } else {
1983 memset(&ifr, 0, sizeof(ifr));
1984 }
1985 if (cmd == TUNGETFEATURES) {
1986 /* Currently this just means: "what IFF flags are valid?".
1987 * This is needed because we never checked for invalid flags on
1988 * TUNSETIFF.
1989 */
1990 return put_user(IFF_TUN | IFF_TAP | TUN_FEATURES,
1991 (unsigned int __user*)argp);
1992 } else if (cmd == TUNSETQUEUE)
1993 return tun_set_queue(file, &ifr);
1994
1995 ret = 0;
1996 rtnl_lock();
1997
1998 tun = __tun_get(tfile);
1999 if (cmd == TUNSETIFF) {
2000 ret = -EEXIST;
2001 if (tun)
2002 goto unlock;
2003
2004 ifr.ifr_name[IFNAMSIZ-1] = '\0';
2005
2006 ret = tun_set_iff(sock_net(&tfile->sk), file, &ifr);
2007
2008 if (ret)
2009 goto unlock;
2010
2011 if (copy_to_user(argp, &ifr, ifreq_len))
2012 ret = -EFAULT;
2013 goto unlock;
2014 }
2015 if (cmd == TUNSETIFINDEX) {
2016 ret = -EPERM;
2017 if (tun)
2018 goto unlock;
2019
2020 ret = -EFAULT;
2021 if (copy_from_user(&ifindex, argp, sizeof(ifindex)))
2022 goto unlock;
2023
2024 ret = 0;
2025 tfile->ifindex = ifindex;
2026 goto unlock;
2027 }
2028
2029 ret = -EBADFD;
2030 if (!tun)
2031 goto unlock;
2032
2033 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %u\n", cmd);
2034
2035 ret = 0;
2036 switch (cmd) {
2037 case TUNGETIFF:
2038 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
2039
2040 if (tfile->detached)
2041 ifr.ifr_flags |= IFF_DETACH_QUEUE;
2042 if (!tfile->socket.sk->sk_filter)
2043 ifr.ifr_flags |= IFF_NOFILTER;
2044
2045 if (copy_to_user(argp, &ifr, ifreq_len))
2046 ret = -EFAULT;
2047 break;
2048
2049 case TUNSETNOCSUM:
2050 /* Disable/Enable checksum */
2051
2052 /* [unimplemented] */
2053 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n",
2054 arg ? "disabled" : "enabled");
2055 break;
2056
2057 case TUNSETPERSIST:
2058 /* Disable/Enable persist mode. Keep an extra reference to the
2059 * module to prevent the module being unprobed.
2060 */
2061 if (arg && !(tun->flags & IFF_PERSIST)) {
2062 tun->flags |= IFF_PERSIST;
2063 __module_get(THIS_MODULE);
2064 }
2065 if (!arg && (tun->flags & IFF_PERSIST)) {
2066 tun->flags &= ~IFF_PERSIST;
2067 module_put(THIS_MODULE);
2068 }
2069
2070 tun_debug(KERN_INFO, tun, "persist %s\n",
2071 arg ? "enabled" : "disabled");
2072 break;
2073
2074 case TUNSETOWNER:
2075 /* Set owner of the device */
2076 owner = make_kuid(current_user_ns(), arg);
2077 if (!uid_valid(owner)) {
2078 ret = -EINVAL;
2079 break;
2080 }
2081 tun->owner = owner;
2082 tun_debug(KERN_INFO, tun, "owner set to %u\n",
2083 from_kuid(&init_user_ns, tun->owner));
2084 break;
2085
2086 case TUNSETGROUP:
2087 /* Set group of the device */
2088 group = make_kgid(current_user_ns(), arg);
2089 if (!gid_valid(group)) {
2090 ret = -EINVAL;
2091 break;
2092 }
2093 tun->group = group;
2094 tun_debug(KERN_INFO, tun, "group set to %u\n",
2095 from_kgid(&init_user_ns, tun->group));
2096 break;
2097
2098 case TUNSETLINK:
2099 /* Only allow setting the type when the interface is down */
2100 if (tun->dev->flags & IFF_UP) {
2101 tun_debug(KERN_INFO, tun,
2102 "Linktype set failed because interface is up\n");
2103 ret = -EBUSY;
2104 } else {
2105 tun->dev->type = (int) arg;
2106 tun_debug(KERN_INFO, tun, "linktype set to %d\n",
2107 tun->dev->type);
2108 ret = 0;
2109 }
2110 break;
2111
2112 #ifdef TUN_DEBUG
2113 case TUNSETDEBUG:
2114 tun->debug = arg;
2115 break;
2116 #endif
2117 case TUNSETOFFLOAD:
2118 ret = set_offload(tun, arg);
2119 break;
2120
2121 case TUNSETTXFILTER:
2122 /* Can be set only for TAPs */
2123 ret = -EINVAL;
2124 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2125 break;
2126 ret = update_filter(&tun->txflt, (void __user *)arg);
2127 break;
2128
2129 case SIOCGIFHWADDR:
2130 /* Get hw address */
2131 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
2132 ifr.ifr_hwaddr.sa_family = tun->dev->type;
2133 if (copy_to_user(argp, &ifr, ifreq_len))
2134 ret = -EFAULT;
2135 break;
2136
2137 case SIOCSIFHWADDR:
2138 /* Set hw address */
2139 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
2140 ifr.ifr_hwaddr.sa_data);
2141
2142 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
2143 break;
2144
2145 case TUNGETSNDBUF:
2146 sndbuf = tfile->socket.sk->sk_sndbuf;
2147 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
2148 ret = -EFAULT;
2149 break;
2150
2151 case TUNSETSNDBUF:
2152 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
2153 ret = -EFAULT;
2154 break;
2155 }
2156
2157 tun->sndbuf = sndbuf;
2158 tun_set_sndbuf(tun);
2159 break;
2160
2161 case TUNGETVNETHDRSZ:
2162 vnet_hdr_sz = tun->vnet_hdr_sz;
2163 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
2164 ret = -EFAULT;
2165 break;
2166
2167 case TUNSETVNETHDRSZ:
2168 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
2169 ret = -EFAULT;
2170 break;
2171 }
2172 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
2173 ret = -EINVAL;
2174 break;
2175 }
2176
2177 tun->vnet_hdr_sz = vnet_hdr_sz;
2178 break;
2179
2180 case TUNGETVNETLE:
2181 le = !!(tun->flags & TUN_VNET_LE);
2182 if (put_user(le, (int __user *)argp))
2183 ret = -EFAULT;
2184 break;
2185
2186 case TUNSETVNETLE:
2187 if (get_user(le, (int __user *)argp)) {
2188 ret = -EFAULT;
2189 break;
2190 }
2191 if (le)
2192 tun->flags |= TUN_VNET_LE;
2193 else
2194 tun->flags &= ~TUN_VNET_LE;
2195 break;
2196
2197 case TUNGETVNETBE:
2198 ret = tun_get_vnet_be(tun, argp);
2199 break;
2200
2201 case TUNSETVNETBE:
2202 ret = tun_set_vnet_be(tun, argp);
2203 break;
2204
2205 case TUNATTACHFILTER:
2206 /* Can be set only for TAPs */
2207 ret = -EINVAL;
2208 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2209 break;
2210 ret = -EFAULT;
2211 if (copy_from_user(&tun->fprog, argp, sizeof(tun->fprog)))
2212 break;
2213
2214 ret = tun_attach_filter(tun);
2215 break;
2216
2217 case TUNDETACHFILTER:
2218 /* Can be set only for TAPs */
2219 ret = -EINVAL;
2220 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2221 break;
2222 ret = 0;
2223 tun_detach_filter(tun, tun->numqueues);
2224 break;
2225
2226 case TUNGETFILTER:
2227 ret = -EINVAL;
2228 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2229 break;
2230 ret = -EFAULT;
2231 if (copy_to_user(argp, &tun->fprog, sizeof(tun->fprog)))
2232 break;
2233 ret = 0;
2234 break;
2235
2236 default:
2237 ret = -EINVAL;
2238 break;
2239 }
2240
2241 unlock:
2242 rtnl_unlock();
2243 if (tun)
2244 tun_put(tun);
2245 return ret;
2246 }
2247
2248 static long tun_chr_ioctl(struct file *file,
2249 unsigned int cmd, unsigned long arg)
2250 {
2251 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
2252 }
2253
2254 #ifdef CONFIG_COMPAT
2255 static long tun_chr_compat_ioctl(struct file *file,
2256 unsigned int cmd, unsigned long arg)
2257 {
2258 switch (cmd) {
2259 case TUNSETIFF:
2260 case TUNGETIFF:
2261 case TUNSETTXFILTER:
2262 case TUNGETSNDBUF:
2263 case TUNSETSNDBUF:
2264 case SIOCGIFHWADDR:
2265 case SIOCSIFHWADDR:
2266 arg = (unsigned long)compat_ptr(arg);
2267 break;
2268 default:
2269 arg = (compat_ulong_t)arg;
2270 break;
2271 }
2272
2273 /*
2274 * compat_ifreq is shorter than ifreq, so we must not access beyond
2275 * the end of that structure. All fields that are used in this
2276 * driver are compatible though, we don't need to convert the
2277 * contents.
2278 */
2279 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
2280 }
2281 #endif /* CONFIG_COMPAT */
2282
2283 static int tun_chr_fasync(int fd, struct file *file, int on)
2284 {
2285 struct tun_file *tfile = file->private_data;
2286 int ret;
2287
2288 if ((ret = fasync_helper(fd, file, on, &tfile->fasync)) < 0)
2289 goto out;
2290
2291 if (on) {
2292 __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
2293 tfile->flags |= TUN_FASYNC;
2294 } else
2295 tfile->flags &= ~TUN_FASYNC;
2296 ret = 0;
2297 out:
2298 return ret;
2299 }
2300
2301 static int tun_chr_open(struct inode *inode, struct file * file)
2302 {
2303 struct net *net = current->nsproxy->net_ns;
2304 struct tun_file *tfile;
2305
2306 DBG1(KERN_INFO, "tunX: tun_chr_open\n");
2307
2308 tfile = (struct tun_file *)sk_alloc(net, AF_UNSPEC, GFP_KERNEL,
2309 &tun_proto, 0);
2310 if (!tfile)
2311 return -ENOMEM;
2312 RCU_INIT_POINTER(tfile->tun, NULL);
2313 tfile->flags = 0;
2314 tfile->ifindex = 0;
2315
2316 init_waitqueue_head(&tfile->wq.wait);
2317 RCU_INIT_POINTER(tfile->socket.wq, &tfile->wq);
2318
2319 tfile->socket.file = file;
2320 tfile->socket.ops = &tun_socket_ops;
2321
2322 sock_init_data(&tfile->socket, &tfile->sk);
2323
2324 tfile->sk.sk_write_space = tun_sock_write_space;
2325 tfile->sk.sk_sndbuf = INT_MAX;
2326
2327 file->private_data = tfile;
2328 INIT_LIST_HEAD(&tfile->next);
2329
2330 sock_set_flag(&tfile->sk, SOCK_ZEROCOPY);
2331
2332 return 0;
2333 }
2334
2335 static int tun_chr_close(struct inode *inode, struct file *file)
2336 {
2337 struct tun_file *tfile = file->private_data;
2338
2339 tun_detach(tfile, true);
2340
2341 return 0;
2342 }
2343
2344 #ifdef CONFIG_PROC_FS
2345 static void tun_chr_show_fdinfo(struct seq_file *m, struct file *f)
2346 {
2347 struct tun_struct *tun;
2348 struct ifreq ifr;
2349
2350 memset(&ifr, 0, sizeof(ifr));
2351
2352 rtnl_lock();
2353 tun = tun_get(f);
2354 if (tun)
2355 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
2356 rtnl_unlock();
2357
2358 if (tun)
2359 tun_put(tun);
2360
2361 seq_printf(m, "iff:\t%s\n", ifr.ifr_name);
2362 }
2363 #endif
2364
2365 static const struct file_operations tun_fops = {
2366 .owner = THIS_MODULE,
2367 .llseek = no_llseek,
2368 .read_iter = tun_chr_read_iter,
2369 .write_iter = tun_chr_write_iter,
2370 .poll = tun_chr_poll,
2371 .unlocked_ioctl = tun_chr_ioctl,
2372 #ifdef CONFIG_COMPAT
2373 .compat_ioctl = tun_chr_compat_ioctl,
2374 #endif
2375 .open = tun_chr_open,
2376 .release = tun_chr_close,
2377 .fasync = tun_chr_fasync,
2378 #ifdef CONFIG_PROC_FS
2379 .show_fdinfo = tun_chr_show_fdinfo,
2380 #endif
2381 };
2382
2383 static struct miscdevice tun_miscdev = {
2384 .minor = TUN_MINOR,
2385 .name = "tun",
2386 .nodename = "net/tun",
2387 .fops = &tun_fops,
2388 };
2389
2390 /* ethtool interface */
2391
2392 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
2393 {
2394 cmd->supported = 0;
2395 cmd->advertising = 0;
2396 ethtool_cmd_speed_set(cmd, SPEED_10);
2397 cmd->duplex = DUPLEX_FULL;
2398 cmd->port = PORT_TP;
2399 cmd->phy_address = 0;
2400 cmd->transceiver = XCVR_INTERNAL;
2401 cmd->autoneg = AUTONEG_DISABLE;
2402 cmd->maxtxpkt = 0;
2403 cmd->maxrxpkt = 0;
2404 return 0;
2405 }
2406
2407 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
2408 {
2409 struct tun_struct *tun = netdev_priv(dev);
2410
2411 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
2412 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
2413
2414 switch (tun->flags & TUN_TYPE_MASK) {
2415 case IFF_TUN:
2416 strlcpy(info->bus_info, "tun", sizeof(info->bus_info));
2417 break;
2418 case IFF_TAP:
2419 strlcpy(info->bus_info, "tap", sizeof(info->bus_info));
2420 break;
2421 }
2422 }
2423
2424 static u32 tun_get_msglevel(struct net_device *dev)
2425 {
2426 #ifdef TUN_DEBUG
2427 struct tun_struct *tun = netdev_priv(dev);
2428 return tun->debug;
2429 #else
2430 return -EOPNOTSUPP;
2431 #endif
2432 }
2433
2434 static void tun_set_msglevel(struct net_device *dev, u32 value)
2435 {
2436 #ifdef TUN_DEBUG
2437 struct tun_struct *tun = netdev_priv(dev);
2438 tun->debug = value;
2439 #endif
2440 }
2441
2442 static const struct ethtool_ops tun_ethtool_ops = {
2443 .get_settings = tun_get_settings,
2444 .get_drvinfo = tun_get_drvinfo,
2445 .get_msglevel = tun_get_msglevel,
2446 .set_msglevel = tun_set_msglevel,
2447 .get_link = ethtool_op_get_link,
2448 .get_ts_info = ethtool_op_get_ts_info,
2449 };
2450
2451 static int tun_queue_resize(struct tun_struct *tun)
2452 {
2453 struct net_device *dev = tun->dev;
2454 struct tun_file *tfile;
2455 struct skb_array **arrays;
2456 int n = tun->numqueues + tun->numdisabled;
2457 int ret, i;
2458
2459 arrays = kmalloc(sizeof *arrays * n, GFP_KERNEL);
2460 if (!arrays)
2461 return -ENOMEM;
2462
2463 for (i = 0; i < tun->numqueues; i++) {
2464 tfile = rtnl_dereference(tun->tfiles[i]);
2465 arrays[i] = &tfile->tx_array;
2466 }
2467 list_for_each_entry(tfile, &tun->disabled, next)
2468 arrays[i++] = &tfile->tx_array;
2469
2470 ret = skb_array_resize_multiple(arrays, n,
2471 dev->tx_queue_len, GFP_KERNEL);
2472
2473 kfree(arrays);
2474 return ret;
2475 }
2476
2477 static int tun_device_event(struct notifier_block *unused,
2478 unsigned long event, void *ptr)
2479 {
2480 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
2481 struct tun_struct *tun = netdev_priv(dev);
2482
2483 if (dev->rtnl_link_ops != &tun_link_ops)
2484 return NOTIFY_DONE;
2485
2486 switch (event) {
2487 case NETDEV_CHANGE_TX_QUEUE_LEN:
2488 if (tun_queue_resize(tun))
2489 return NOTIFY_BAD;
2490 break;
2491 default:
2492 break;
2493 }
2494
2495 return NOTIFY_DONE;
2496 }
2497
2498 static struct notifier_block tun_notifier_block __read_mostly = {
2499 .notifier_call = tun_device_event,
2500 };
2501
2502 static int __init tun_init(void)
2503 {
2504 int ret = 0;
2505
2506 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
2507 pr_info("%s\n", DRV_COPYRIGHT);
2508
2509 ret = rtnl_link_register(&tun_link_ops);
2510 if (ret) {
2511 pr_err("Can't register link_ops\n");
2512 goto err_linkops;
2513 }
2514
2515 ret = misc_register(&tun_miscdev);
2516 if (ret) {
2517 pr_err("Can't register misc device %d\n", TUN_MINOR);
2518 goto err_misc;
2519 }
2520
2521 register_netdevice_notifier(&tun_notifier_block);
2522 return 0;
2523 err_misc:
2524 rtnl_link_unregister(&tun_link_ops);
2525 err_linkops:
2526 return ret;
2527 }
2528
2529 static void tun_cleanup(void)
2530 {
2531 misc_deregister(&tun_miscdev);
2532 rtnl_link_unregister(&tun_link_ops);
2533 unregister_netdevice_notifier(&tun_notifier_block);
2534 }
2535
2536 /* Get an underlying socket object from tun file. Returns error unless file is
2537 * attached to a device. The returned object works like a packet socket, it
2538 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
2539 * holding a reference to the file for as long as the socket is in use. */
2540 struct socket *tun_get_socket(struct file *file)
2541 {
2542 struct tun_file *tfile;
2543 if (file->f_op != &tun_fops)
2544 return ERR_PTR(-EINVAL);
2545 tfile = file->private_data;
2546 if (!tfile)
2547 return ERR_PTR(-EBADFD);
2548 return &tfile->socket;
2549 }
2550 EXPORT_SYMBOL_GPL(tun_get_socket);
2551
2552 module_init(tun_init);
2553 module_exit(tun_cleanup);
2554 MODULE_DESCRIPTION(DRV_DESCRIPTION);
2555 MODULE_AUTHOR(DRV_COPYRIGHT);
2556 MODULE_LICENSE("GPL");
2557 MODULE_ALIAS_MISCDEV(TUN_MINOR);
2558 MODULE_ALIAS("devname:net/tun");
Linux with added FPC-III support