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cxl: Poll for outstanding IRQs when detaching a context
[linux/fpc-iii.git] / drivers / net / tun.c
blobafdf950617c36e0bc5042da9cf0e57a0cb0cd88d
1 /*
2 * TUN - Universal TUN/TAP device driver.
3 * Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $
16 */
17
18 /*
19 * Changes:
20 *
21 * Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
22 * Add TUNSETLINK ioctl to set the link encapsulation
23 *
24 * Mark Smith <markzzzsmith@yahoo.com.au>
25 * Use eth_random_addr() for tap MAC address.
26 *
27 * Harald Roelle <harald.roelle@ifi.lmu.de> 2004/04/20
28 * Fixes in packet dropping, queue length setting and queue wakeup.
29 * Increased default tx queue length.
30 * Added ethtool API.
31 * Minor cleanups
32 *
33 * Daniel Podlejski <underley@underley.eu.org>
34 * Modifications for 2.3.99-pre5 kernel.
35 */
36
37 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
38
39 #define DRV_NAME "tun"
40 #define DRV_VERSION "1.6"
41 #define DRV_DESCRIPTION "Universal TUN/TAP device driver"
42 #define DRV_COPYRIGHT "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>"
43
44 #include <linux/module.h>
45 #include <linux/errno.h>
46 #include <linux/kernel.h>
47 #include <linux/major.h>
48 #include <linux/slab.h>
49 #include <linux/poll.h>
50 #include <linux/fcntl.h>
51 #include <linux/init.h>
52 #include <linux/skbuff.h>
53 #include <linux/netdevice.h>
54 #include <linux/etherdevice.h>
55 #include <linux/miscdevice.h>
56 #include <linux/ethtool.h>
57 #include <linux/rtnetlink.h>
58 #include <linux/compat.h>
59 #include <linux/if.h>
60 #include <linux/if_arp.h>
61 #include <linux/if_ether.h>
62 #include <linux/if_tun.h>
63 #include <linux/if_vlan.h>
64 #include <linux/crc32.h>
65 #include <linux/nsproxy.h>
66 #include <linux/virtio_net.h>
67 #include <linux/rcupdate.h>
68 #include <net/net_namespace.h>
69 #include <net/netns/generic.h>
70 #include <net/rtnetlink.h>
71 #include <net/sock.h>
72 #include <linux/seq_file.h>
73 #include <linux/uio.h>
74
75 #include <asm/uaccess.h>
76
77 /* Uncomment to enable debugging */
78 /* #define TUN_DEBUG 1 */
79
80 #ifdef TUN_DEBUG
81 static int debug;
82
83 #define tun_debug(level, tun, fmt, args...) \
84 do { \
85 if (tun->debug) \
86 netdev_printk(level, tun->dev, fmt, ##args); \
87 } while (0)
88 #define DBG1(level, fmt, args...) \
89 do { \
90 if (debug == 2) \
91 printk(level fmt, ##args); \
92 } while (0)
93 #else
94 #define tun_debug(level, tun, fmt, args...) \
95 do { \
96 if (0) \
97 netdev_printk(level, tun->dev, fmt, ##args); \
98 } while (0)
99 #define DBG1(level, fmt, args...) \
100 do { \
101 if (0) \
102 printk(level fmt, ##args); \
103 } while (0)
104 #endif
105
106 /* TUN device flags */
107
108 /* IFF_ATTACH_QUEUE is never stored in device flags,
109 * overload it to mean fasync when stored there.
110 */
111 #define TUN_FASYNC IFF_ATTACH_QUEUE
112 /* High bits in flags field are unused. */
113 #define TUN_VNET_LE 0x80000000
114 #define TUN_VNET_BE 0x40000000
115
116 #define TUN_FEATURES (IFF_NO_PI | IFF_ONE_QUEUE | IFF_VNET_HDR | \
117 IFF_MULTI_QUEUE)
118 #define GOODCOPY_LEN 128
119
120 #define FLT_EXACT_COUNT 8
121 struct tap_filter {
122 unsigned int count; /* Number of addrs. Zero means disabled */
123 u32 mask[2]; /* Mask of the hashed addrs */
124 unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN];
125 };
126
127 /* MAX_TAP_QUEUES 256 is chosen to allow rx/tx queues to be equal
128 * to max number of VCPUs in guest. */
129 #define MAX_TAP_QUEUES 256
130 #define MAX_TAP_FLOWS 4096
131
132 #define TUN_FLOW_EXPIRE (3 * HZ)
133
134 /* A tun_file connects an open character device to a tuntap netdevice. It
135 * also contains all socket related structures (except sock_fprog and tap_filter)
136 * to serve as one transmit queue for tuntap device. The sock_fprog and
137 * tap_filter were kept in tun_struct since they were used for filtering for the
138 * netdevice not for a specific queue (at least I didn't see the requirement for
139 * this).
140 *
141 * RCU usage:
142 * The tun_file and tun_struct are loosely coupled, the pointer from one to the
143 * other can only be read while rcu_read_lock or rtnl_lock is held.
144 */
145 struct tun_file {
146 struct sock sk;
147 struct socket socket;
148 struct socket_wq wq;
149 struct tun_struct __rcu *tun;
150 struct fasync_struct *fasync;
151 /* only used for fasnyc */
152 unsigned int flags;
153 union {
154 u16 queue_index;
155 unsigned int ifindex;
156 };
157 struct list_head next;
158 struct tun_struct *detached;
159 };
160
161 struct tun_flow_entry {
162 struct hlist_node hash_link;
163 struct rcu_head rcu;
164 struct tun_struct *tun;
165
166 u32 rxhash;
167 u32 rps_rxhash;
168 int queue_index;
169 unsigned long updated;
170 };
171
172 #define TUN_NUM_FLOW_ENTRIES 1024
173
174 /* Since the socket were moved to tun_file, to preserve the behavior of persist
175 * device, socket filter, sndbuf and vnet header size were restore when the
176 * file were attached to a persist device.
177 */
178 struct tun_struct {
179 struct tun_file __rcu *tfiles[MAX_TAP_QUEUES];
180 unsigned int numqueues;
181 unsigned int flags;
182 kuid_t owner;
183 kgid_t group;
184
185 struct net_device *dev;
186 netdev_features_t set_features;
187 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
188 NETIF_F_TSO6|NETIF_F_UFO)
189
190 int align;
191 int vnet_hdr_sz;
192 int sndbuf;
193 struct tap_filter txflt;
194 struct sock_fprog fprog;
195 /* protected by rtnl lock */
196 bool filter_attached;
197 #ifdef TUN_DEBUG
198 int debug;
199 #endif
200 spinlock_t lock;
201 struct hlist_head flows[TUN_NUM_FLOW_ENTRIES];
202 struct timer_list flow_gc_timer;
203 unsigned long ageing_time;
204 unsigned int numdisabled;
205 struct list_head disabled;
206 void *security;
207 u32 flow_count;
208 };
209
210 #ifdef CONFIG_TUN_VNET_CROSS_LE
211 static inline bool tun_legacy_is_little_endian(struct tun_struct *tun)
212 {
213 return tun->flags & TUN_VNET_BE ? false :
214 virtio_legacy_is_little_endian();
215 }
216
217 static long tun_get_vnet_be(struct tun_struct *tun, int __user *argp)
218 {
219 int be = !!(tun->flags & TUN_VNET_BE);
220
221 if (put_user(be, argp))
222 return -EFAULT;
223
224 return 0;
225 }
226
227 static long tun_set_vnet_be(struct tun_struct *tun, int __user *argp)
228 {
229 int be;
230
231 if (get_user(be, argp))
232 return -EFAULT;
233
234 if (be)
235 tun->flags |= TUN_VNET_BE;
236 else
237 tun->flags &= ~TUN_VNET_BE;
238
239 return 0;
240 }
241 #else
242 static inline bool tun_legacy_is_little_endian(struct tun_struct *tun)
243 {
244 return virtio_legacy_is_little_endian();
245 }
246
247 static long tun_get_vnet_be(struct tun_struct *tun, int __user *argp)
248 {
249 return -EINVAL;
250 }
251
252 static long tun_set_vnet_be(struct tun_struct *tun, int __user *argp)
253 {
254 return -EINVAL;
255 }
256 #endif /* CONFIG_TUN_VNET_CROSS_LE */
257
258 static inline bool tun_is_little_endian(struct tun_struct *tun)
259 {
260 return tun->flags & TUN_VNET_LE ||
261 tun_legacy_is_little_endian(tun);
262 }
263
264 static inline u16 tun16_to_cpu(struct tun_struct *tun, __virtio16 val)
265 {
266 return __virtio16_to_cpu(tun_is_little_endian(tun), val);
267 }
268
269 static inline __virtio16 cpu_to_tun16(struct tun_struct *tun, u16 val)
270 {
271 return __cpu_to_virtio16(tun_is_little_endian(tun), val);
272 }
273
274 static inline u32 tun_hashfn(u32 rxhash)
275 {
276 return rxhash & 0x3ff;
277 }
278
279 static struct tun_flow_entry *tun_flow_find(struct hlist_head *head, u32 rxhash)
280 {
281 struct tun_flow_entry *e;
282
283 hlist_for_each_entry_rcu(e, head, hash_link) {
284 if (e->rxhash == rxhash)
285 return e;
286 }
287 return NULL;
288 }
289
290 static struct tun_flow_entry *tun_flow_create(struct tun_struct *tun,
291 struct hlist_head *head,
292 u32 rxhash, u16 queue_index)
293 {
294 struct tun_flow_entry *e = kmalloc(sizeof(*e), GFP_ATOMIC);
295
296 if (e) {
297 tun_debug(KERN_INFO, tun, "create flow: hash %u index %u\n",
298 rxhash, queue_index);
299 e->updated = jiffies;
300 e->rxhash = rxhash;
301 e->rps_rxhash = 0;
302 e->queue_index = queue_index;
303 e->tun = tun;
304 hlist_add_head_rcu(&e->hash_link, head);
305 ++tun->flow_count;
306 }
307 return e;
308 }
309
310 static void tun_flow_delete(struct tun_struct *tun, struct tun_flow_entry *e)
311 {
312 tun_debug(KERN_INFO, tun, "delete flow: hash %u index %u\n",
313 e->rxhash, e->queue_index);
314 hlist_del_rcu(&e->hash_link);
315 kfree_rcu(e, rcu);
316 --tun->flow_count;
317 }
318
319 static void tun_flow_flush(struct tun_struct *tun)
320 {
321 int i;
322
323 spin_lock_bh(&tun->lock);
324 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
325 struct tun_flow_entry *e;
326 struct hlist_node *n;
327
328 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link)
329 tun_flow_delete(tun, e);
330 }
331 spin_unlock_bh(&tun->lock);
332 }
333
334 static void tun_flow_delete_by_queue(struct tun_struct *tun, u16 queue_index)
335 {
336 int i;
337
338 spin_lock_bh(&tun->lock);
339 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
340 struct tun_flow_entry *e;
341 struct hlist_node *n;
342
343 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
344 if (e->queue_index == queue_index)
345 tun_flow_delete(tun, e);
346 }
347 }
348 spin_unlock_bh(&tun->lock);
349 }
350
351 static void tun_flow_cleanup(unsigned long data)
352 {
353 struct tun_struct *tun = (struct tun_struct *)data;
354 unsigned long delay = tun->ageing_time;
355 unsigned long next_timer = jiffies + delay;
356 unsigned long count = 0;
357 int i;
358
359 tun_debug(KERN_INFO, tun, "tun_flow_cleanup\n");
360
361 spin_lock_bh(&tun->lock);
362 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
363 struct tun_flow_entry *e;
364 struct hlist_node *n;
365
366 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
367 unsigned long this_timer;
368 count++;
369 this_timer = e->updated + delay;
370 if (time_before_eq(this_timer, jiffies))
371 tun_flow_delete(tun, e);
372 else if (time_before(this_timer, next_timer))
373 next_timer = this_timer;
374 }
375 }
376
377 if (count)
378 mod_timer(&tun->flow_gc_timer, round_jiffies_up(next_timer));
379 spin_unlock_bh(&tun->lock);
380 }
381
382 static void tun_flow_update(struct tun_struct *tun, u32 rxhash,
383 struct tun_file *tfile)
384 {
385 struct hlist_head *head;
386 struct tun_flow_entry *e;
387 unsigned long delay = tun->ageing_time;
388 u16 queue_index = tfile->queue_index;
389
390 if (!rxhash)
391 return;
392 else
393 head = &tun->flows[tun_hashfn(rxhash)];
394
395 rcu_read_lock();
396
397 /* We may get a very small possibility of OOO during switching, not
398 * worth to optimize.*/
399 if (tun->numqueues == 1 || tfile->detached)
400 goto unlock;
401
402 e = tun_flow_find(head, rxhash);
403 if (likely(e)) {
404 /* TODO: keep queueing to old queue until it's empty? */
405 e->queue_index = queue_index;
406 e->updated = jiffies;
407 sock_rps_record_flow_hash(e->rps_rxhash);
408 } else {
409 spin_lock_bh(&tun->lock);
410 if (!tun_flow_find(head, rxhash) &&
411 tun->flow_count < MAX_TAP_FLOWS)
412 tun_flow_create(tun, head, rxhash, queue_index);
413
414 if (!timer_pending(&tun->flow_gc_timer))
415 mod_timer(&tun->flow_gc_timer,
416 round_jiffies_up(jiffies + delay));
417 spin_unlock_bh(&tun->lock);
418 }
419
420 unlock:
421 rcu_read_unlock();
422 }
423
424 /**
425 * Save the hash received in the stack receive path and update the
426 * flow_hash table accordingly.
427 */
428 static inline void tun_flow_save_rps_rxhash(struct tun_flow_entry *e, u32 hash)
429 {
430 if (unlikely(e->rps_rxhash != hash))
431 e->rps_rxhash = hash;
432 }
433
434 /* We try to identify a flow through its rxhash first. The reason that
435 * we do not check rxq no. is because some cards(e.g 82599), chooses
436 * the rxq based on the txq where the last packet of the flow comes. As
437 * the userspace application move between processors, we may get a
438 * different rxq no. here. If we could not get rxhash, then we would
439 * hope the rxq no. may help here.
440 */
441 static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb,
442 void *accel_priv, select_queue_fallback_t fallback)
443 {
444 struct tun_struct *tun = netdev_priv(dev);
445 struct tun_flow_entry *e;
446 u32 txq = 0;
447 u32 numqueues = 0;
448
449 rcu_read_lock();
450 numqueues = ACCESS_ONCE(tun->numqueues);
451
452 txq = skb_get_hash(skb);
453 if (txq) {
454 e = tun_flow_find(&tun->flows[tun_hashfn(txq)], txq);
455 if (e) {
456 tun_flow_save_rps_rxhash(e, txq);
457 txq = e->queue_index;
458 } else
459 /* use multiply and shift instead of expensive divide */
460 txq = ((u64)txq * numqueues) >> 32;
461 } else if (likely(skb_rx_queue_recorded(skb))) {
462 txq = skb_get_rx_queue(skb);
463 while (unlikely(txq >= numqueues))
464 txq -= numqueues;
465 }
466
467 rcu_read_unlock();
468 return txq;
469 }
470
471 static inline bool tun_not_capable(struct tun_struct *tun)
472 {
473 const struct cred *cred = current_cred();
474 struct net *net = dev_net(tun->dev);
475
476 return ((uid_valid(tun->owner) && !uid_eq(cred->euid, tun->owner)) ||
477 (gid_valid(tun->group) && !in_egroup_p(tun->group))) &&
478 !ns_capable(net->user_ns, CAP_NET_ADMIN);
479 }
480
481 static void tun_set_real_num_queues(struct tun_struct *tun)
482 {
483 netif_set_real_num_tx_queues(tun->dev, tun->numqueues);
484 netif_set_real_num_rx_queues(tun->dev, tun->numqueues);
485 }
486
487 static void tun_disable_queue(struct tun_struct *tun, struct tun_file *tfile)
488 {
489 tfile->detached = tun;
490 list_add_tail(&tfile->next, &tun->disabled);
491 ++tun->numdisabled;
492 }
493
494 static struct tun_struct *tun_enable_queue(struct tun_file *tfile)
495 {
496 struct tun_struct *tun = tfile->detached;
497
498 tfile->detached = NULL;
499 list_del_init(&tfile->next);
500 --tun->numdisabled;
501 return tun;
502 }
503
504 static void tun_queue_purge(struct tun_file *tfile)
505 {
506 skb_queue_purge(&tfile->sk.sk_receive_queue);
507 skb_queue_purge(&tfile->sk.sk_error_queue);
508 }
509
510 static void __tun_detach(struct tun_file *tfile, bool clean)
511 {
512 struct tun_file *ntfile;
513 struct tun_struct *tun;
514
515 tun = rtnl_dereference(tfile->tun);
516
517 if (tun && !tfile->detached) {
518 u16 index = tfile->queue_index;
519 BUG_ON(index >= tun->numqueues);
520
521 rcu_assign_pointer(tun->tfiles[index],
522 tun->tfiles[tun->numqueues - 1]);
523 ntfile = rtnl_dereference(tun->tfiles[index]);
524 ntfile->queue_index = index;
525
526 --tun->numqueues;
527 if (clean) {
528 RCU_INIT_POINTER(tfile->tun, NULL);
529 sock_put(&tfile->sk);
530 } else
531 tun_disable_queue(tun, tfile);
532
533 synchronize_net();
534 tun_flow_delete_by_queue(tun, tun->numqueues + 1);
535 /* Drop read queue */
536 tun_queue_purge(tfile);
537 tun_set_real_num_queues(tun);
538 } else if (tfile->detached && clean) {
539 tun = tun_enable_queue(tfile);
540 sock_put(&tfile->sk);
541 }
542
543 if (clean) {
544 if (tun && tun->numqueues == 0 && tun->numdisabled == 0) {
545 netif_carrier_off(tun->dev);
546
547 if (!(tun->flags & IFF_PERSIST) &&
548 tun->dev->reg_state == NETREG_REGISTERED)
549 unregister_netdevice(tun->dev);
550 }
551 sock_put(&tfile->sk);
552 }
553 }
554
555 static void tun_detach(struct tun_file *tfile, bool clean)
556 {
557 rtnl_lock();
558 __tun_detach(tfile, clean);
559 rtnl_unlock();
560 }
561
562 static void tun_detach_all(struct net_device *dev)
563 {
564 struct tun_struct *tun = netdev_priv(dev);
565 struct tun_file *tfile, *tmp;
566 int i, n = tun->numqueues;
567
568 for (i = 0; i < n; i++) {
569 tfile = rtnl_dereference(tun->tfiles[i]);
570 BUG_ON(!tfile);
571 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
572 RCU_INIT_POINTER(tfile->tun, NULL);
573 --tun->numqueues;
574 }
575 list_for_each_entry(tfile, &tun->disabled, next) {
576 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
577 RCU_INIT_POINTER(tfile->tun, NULL);
578 }
579 BUG_ON(tun->numqueues != 0);
580
581 synchronize_net();
582 for (i = 0; i < n; i++) {
583 tfile = rtnl_dereference(tun->tfiles[i]);
584 /* Drop read queue */
585 tun_queue_purge(tfile);
586 sock_put(&tfile->sk);
587 }
588 list_for_each_entry_safe(tfile, tmp, &tun->disabled, next) {
589 tun_enable_queue(tfile);
590 tun_queue_purge(tfile);
591 sock_put(&tfile->sk);
592 }
593 BUG_ON(tun->numdisabled != 0);
594
595 if (tun->flags & IFF_PERSIST)
596 module_put(THIS_MODULE);
597 }
598
599 static int tun_attach(struct tun_struct *tun, struct file *file, bool skip_filter)
600 {
601 struct tun_file *tfile = file->private_data;
602 int err;
603
604 err = security_tun_dev_attach(tfile->socket.sk, tun->security);
605 if (err < 0)
606 goto out;
607
608 err = -EINVAL;
609 if (rtnl_dereference(tfile->tun) && !tfile->detached)
610 goto out;
611
612 err = -EBUSY;
613 if (!(tun->flags & IFF_MULTI_QUEUE) && tun->numqueues == 1)
614 goto out;
615
616 err = -E2BIG;
617 if (!tfile->detached &&
618 tun->numqueues + tun->numdisabled == MAX_TAP_QUEUES)
619 goto out;
620
621 err = 0;
622
623 /* Re-attach the filter to persist device */
624 if (!skip_filter && (tun->filter_attached == true)) {
625 err = sk_attach_filter(&tun->fprog, tfile->socket.sk);
626 if (!err)
627 goto out;
628 }
629 tfile->queue_index = tun->numqueues;
630 rcu_assign_pointer(tfile->tun, tun);
631 rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile);
632 tun->numqueues++;
633
634 if (tfile->detached)
635 tun_enable_queue(tfile);
636 else
637 sock_hold(&tfile->sk);
638
639 tun_set_real_num_queues(tun);
640
641 /* device is allowed to go away first, so no need to hold extra
642 * refcnt.
643 */
644
645 out:
646 return err;
647 }
648
649 static struct tun_struct *__tun_get(struct tun_file *tfile)
650 {
651 struct tun_struct *tun;
652
653 rcu_read_lock();
654 tun = rcu_dereference(tfile->tun);
655 if (tun)
656 dev_hold(tun->dev);
657 rcu_read_unlock();
658
659 return tun;
660 }
661
662 static struct tun_struct *tun_get(struct file *file)
663 {
664 return __tun_get(file->private_data);
665 }
666
667 static void tun_put(struct tun_struct *tun)
668 {
669 dev_put(tun->dev);
670 }
671
672 /* TAP filtering */
673 static void addr_hash_set(u32 *mask, const u8 *addr)
674 {
675 int n = ether_crc(ETH_ALEN, addr) >> 26;
676 mask[n >> 5] |= (1 << (n & 31));
677 }
678
679 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
680 {
681 int n = ether_crc(ETH_ALEN, addr) >> 26;
682 return mask[n >> 5] & (1 << (n & 31));
683 }
684
685 static int update_filter(struct tap_filter *filter, void __user *arg)
686 {
687 struct { u8 u[ETH_ALEN]; } *addr;
688 struct tun_filter uf;
689 int err, alen, n, nexact;
690
691 if (copy_from_user(&uf, arg, sizeof(uf)))
692 return -EFAULT;
693
694 if (!uf.count) {
695 /* Disabled */
696 filter->count = 0;
697 return 0;
698 }
699
700 alen = ETH_ALEN * uf.count;
701 addr = kmalloc(alen, GFP_KERNEL);
702 if (!addr)
703 return -ENOMEM;
704
705 if (copy_from_user(addr, arg + sizeof(uf), alen)) {
706 err = -EFAULT;
707 goto done;
708 }
709
710 /* The filter is updated without holding any locks. Which is
711 * perfectly safe. We disable it first and in the worst
712 * case we'll accept a few undesired packets. */
713 filter->count = 0;
714 wmb();
715
716 /* Use first set of addresses as an exact filter */
717 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
718 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
719
720 nexact = n;
721
722 /* Remaining multicast addresses are hashed,
723 * unicast will leave the filter disabled. */
724 memset(filter->mask, 0, sizeof(filter->mask));
725 for (; n < uf.count; n++) {
726 if (!is_multicast_ether_addr(addr[n].u)) {
727 err = 0; /* no filter */
728 goto done;
729 }
730 addr_hash_set(filter->mask, addr[n].u);
731 }
732
733 /* For ALLMULTI just set the mask to all ones.
734 * This overrides the mask populated above. */
735 if ((uf.flags & TUN_FLT_ALLMULTI))
736 memset(filter->mask, ~0, sizeof(filter->mask));
737
738 /* Now enable the filter */
739 wmb();
740 filter->count = nexact;
741
742 /* Return the number of exact filters */
743 err = nexact;
744
745 done:
746 kfree(addr);
747 return err;
748 }
749
750 /* Returns: 0 - drop, !=0 - accept */
751 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
752 {
753 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
754 * at this point. */
755 struct ethhdr *eh = (struct ethhdr *) skb->data;
756 int i;
757
758 /* Exact match */
759 for (i = 0; i < filter->count; i++)
760 if (ether_addr_equal(eh->h_dest, filter->addr[i]))
761 return 1;
762
763 /* Inexact match (multicast only) */
764 if (is_multicast_ether_addr(eh->h_dest))
765 return addr_hash_test(filter->mask, eh->h_dest);
766
767 return 0;
768 }
769
770 /*
771 * Checks whether the packet is accepted or not.
772 * Returns: 0 - drop, !=0 - accept
773 */
774 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
775 {
776 if (!filter->count)
777 return 1;
778
779 return run_filter(filter, skb);
780 }
781
782 /* Network device part of the driver */
783
784 static const struct ethtool_ops tun_ethtool_ops;
785
786 /* Net device detach from fd. */
787 static void tun_net_uninit(struct net_device *dev)
788 {
789 tun_detach_all(dev);
790 }
791
792 /* Net device open. */
793 static int tun_net_open(struct net_device *dev)
794 {
795 netif_tx_start_all_queues(dev);
796 return 0;
797 }
798
799 /* Net device close. */
800 static int tun_net_close(struct net_device *dev)
801 {
802 netif_tx_stop_all_queues(dev);
803 return 0;
804 }
805
806 /* Net device start xmit */
807 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
808 {
809 struct tun_struct *tun = netdev_priv(dev);
810 int txq = skb->queue_mapping;
811 struct tun_file *tfile;
812 u32 numqueues = 0;
813
814 rcu_read_lock();
815 tfile = rcu_dereference(tun->tfiles[txq]);
816 numqueues = ACCESS_ONCE(tun->numqueues);
817
818 /* Drop packet if interface is not attached */
819 if (txq >= numqueues)
820 goto drop;
821
822 if (numqueues == 1) {
823 /* Select queue was not called for the skbuff, so we extract the
824 * RPS hash and save it into the flow_table here.
825 */
826 __u32 rxhash;
827
828 rxhash = skb_get_hash(skb);
829 if (rxhash) {
830 struct tun_flow_entry *e;
831 e = tun_flow_find(&tun->flows[tun_hashfn(rxhash)],
832 rxhash);
833 if (e)
834 tun_flow_save_rps_rxhash(e, rxhash);
835 }
836 }
837
838 tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len);
839
840 BUG_ON(!tfile);
841
842 /* Drop if the filter does not like it.
843 * This is a noop if the filter is disabled.
844 * Filter can be enabled only for the TAP devices. */
845 if (!check_filter(&tun->txflt, skb))
846 goto drop;
847
848 if (tfile->socket.sk->sk_filter &&
849 sk_filter(tfile->socket.sk, skb))
850 goto drop;
851
852 /* Limit the number of packets queued by dividing txq length with the
853 * number of queues.
854 */
855 if (skb_queue_len(&tfile->socket.sk->sk_receive_queue) * numqueues
856 >= dev->tx_queue_len)
857 goto drop;
858
859 if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
860 goto drop;
861
862 if (skb->sk && sk_fullsock(skb->sk)) {
863 sock_tx_timestamp(skb->sk, &skb_shinfo(skb)->tx_flags);
864 sw_tx_timestamp(skb);
865 }
866
867 /* Orphan the skb - required as we might hang on to it
868 * for indefinite time.
869 */
870 skb_orphan(skb);
871
872 nf_reset(skb);
873
874 /* Enqueue packet */
875 skb_queue_tail(&tfile->socket.sk->sk_receive_queue, skb);
876
877 /* Notify and wake up reader process */
878 if (tfile->flags & TUN_FASYNC)
879 kill_fasync(&tfile->fasync, SIGIO, POLL_IN);
880 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
881
882 rcu_read_unlock();
883 return NETDEV_TX_OK;
884
885 drop:
886 dev->stats.tx_dropped++;
887 skb_tx_error(skb);
888 kfree_skb(skb);
889 rcu_read_unlock();
890 return NET_XMIT_DROP;
891 }
892
893 static void tun_net_mclist(struct net_device *dev)
894 {
895 /*
896 * This callback is supposed to deal with mc filter in
897 * _rx_ path and has nothing to do with the _tx_ path.
898 * In rx path we always accept everything userspace gives us.
899 */
900 }
901
902 #define MIN_MTU 68
903 #define MAX_MTU 65535
904
905 static int
906 tun_net_change_mtu(struct net_device *dev, int new_mtu)
907 {
908 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
909 return -EINVAL;
910 dev->mtu = new_mtu;
911 return 0;
912 }
913
914 static netdev_features_t tun_net_fix_features(struct net_device *dev,
915 netdev_features_t features)
916 {
917 struct tun_struct *tun = netdev_priv(dev);
918
919 return (features & tun->set_features) | (features & ~TUN_USER_FEATURES);
920 }
921 #ifdef CONFIG_NET_POLL_CONTROLLER
922 static void tun_poll_controller(struct net_device *dev)
923 {
924 /*
925 * Tun only receives frames when:
926 * 1) the char device endpoint gets data from user space
927 * 2) the tun socket gets a sendmsg call from user space
928 * Since both of those are synchronous operations, we are guaranteed
929 * never to have pending data when we poll for it
930 * so there is nothing to do here but return.
931 * We need this though so netpoll recognizes us as an interface that
932 * supports polling, which enables bridge devices in virt setups to
933 * still use netconsole
934 */
935 return;
936 }
937 #endif
938
939 static void tun_set_headroom(struct net_device *dev, int new_hr)
940 {
941 struct tun_struct *tun = netdev_priv(dev);
942
943 if (new_hr < NET_SKB_PAD)
944 new_hr = NET_SKB_PAD;
945
946 tun->align = new_hr;
947 }
948
949 static const struct net_device_ops tun_netdev_ops = {
950 .ndo_uninit = tun_net_uninit,
951 .ndo_open = tun_net_open,
952 .ndo_stop = tun_net_close,
953 .ndo_start_xmit = tun_net_xmit,
954 .ndo_change_mtu = tun_net_change_mtu,
955 .ndo_fix_features = tun_net_fix_features,
956 .ndo_select_queue = tun_select_queue,
957 #ifdef CONFIG_NET_POLL_CONTROLLER
958 .ndo_poll_controller = tun_poll_controller,
959 #endif
960 .ndo_set_rx_headroom = tun_set_headroom,
961 };
962
963 static const struct net_device_ops tap_netdev_ops = {
964 .ndo_uninit = tun_net_uninit,
965 .ndo_open = tun_net_open,
966 .ndo_stop = tun_net_close,
967 .ndo_start_xmit = tun_net_xmit,
968 .ndo_change_mtu = tun_net_change_mtu,
969 .ndo_fix_features = tun_net_fix_features,
970 .ndo_set_rx_mode = tun_net_mclist,
971 .ndo_set_mac_address = eth_mac_addr,
972 .ndo_validate_addr = eth_validate_addr,
973 .ndo_select_queue = tun_select_queue,
974 #ifdef CONFIG_NET_POLL_CONTROLLER
975 .ndo_poll_controller = tun_poll_controller,
976 #endif
977 .ndo_features_check = passthru_features_check,
978 .ndo_set_rx_headroom = tun_set_headroom,
979 };
980
981 static void tun_flow_init(struct tun_struct *tun)
982 {
983 int i;
984
985 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++)
986 INIT_HLIST_HEAD(&tun->flows[i]);
987
988 tun->ageing_time = TUN_FLOW_EXPIRE;
989 setup_timer(&tun->flow_gc_timer, tun_flow_cleanup, (unsigned long)tun);
990 mod_timer(&tun->flow_gc_timer,
991 round_jiffies_up(jiffies + tun->ageing_time));
992 }
993
994 static void tun_flow_uninit(struct tun_struct *tun)
995 {
996 del_timer_sync(&tun->flow_gc_timer);
997 tun_flow_flush(tun);
998 }
999
1000 /* Initialize net device. */
1001 static void tun_net_init(struct net_device *dev)
1002 {
1003 struct tun_struct *tun = netdev_priv(dev);
1004
1005 switch (tun->flags & TUN_TYPE_MASK) {
1006 case IFF_TUN:
1007 dev->netdev_ops = &tun_netdev_ops;
1008
1009 /* Point-to-Point TUN Device */
1010 dev->hard_header_len = 0;
1011 dev->addr_len = 0;
1012 dev->mtu = 1500;
1013
1014 /* Zero header length */
1015 dev->type = ARPHRD_NONE;
1016 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1017 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
1018 break;
1019
1020 case IFF_TAP:
1021 dev->netdev_ops = &tap_netdev_ops;
1022 /* Ethernet TAP Device */
1023 ether_setup(dev);
1024 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1025 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1026
1027 eth_hw_addr_random(dev);
1028
1029 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
1030 break;
1031 }
1032 }
1033
1034 /* Character device part */
1035
1036 /* Poll */
1037 static unsigned int tun_chr_poll(struct file *file, poll_table *wait)
1038 {
1039 struct tun_file *tfile = file->private_data;
1040 struct tun_struct *tun = __tun_get(tfile);
1041 struct sock *sk;
1042 unsigned int mask = 0;
1043
1044 if (!tun)
1045 return POLLERR;
1046
1047 sk = tfile->socket.sk;
1048
1049 tun_debug(KERN_INFO, tun, "tun_chr_poll\n");
1050
1051 poll_wait(file, sk_sleep(sk), wait);
1052
1053 if (!skb_queue_empty(&sk->sk_receive_queue))
1054 mask |= POLLIN | POLLRDNORM;
1055
1056 if (sock_writeable(sk) ||
1057 (!test_and_set_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
1058 sock_writeable(sk)))
1059 mask |= POLLOUT | POLLWRNORM;
1060
1061 if (tun->dev->reg_state != NETREG_REGISTERED)
1062 mask = POLLERR;
1063
1064 tun_put(tun);
1065 return mask;
1066 }
1067
1068 /* prepad is the amount to reserve at front. len is length after that.
1069 * linear is a hint as to how much to copy (usually headers). */
1070 static struct sk_buff *tun_alloc_skb(struct tun_file *tfile,
1071 size_t prepad, size_t len,
1072 size_t linear, int noblock)
1073 {
1074 struct sock *sk = tfile->socket.sk;
1075 struct sk_buff *skb;
1076 int err;
1077
1078 /* Under a page? Don't bother with paged skb. */
1079 if (prepad + len < PAGE_SIZE || !linear)
1080 linear = len;
1081
1082 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
1083 &err, 0);
1084 if (!skb)
1085 return ERR_PTR(err);
1086
1087 skb_reserve(skb, prepad);
1088 skb_put(skb, linear);
1089 skb->data_len = len - linear;
1090 skb->len += len - linear;
1091
1092 return skb;
1093 }
1094
1095 /* Get packet from user space buffer */
1096 static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
1097 void *msg_control, struct iov_iter *from,
1098 int noblock)
1099 {
1100 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
1101 struct sk_buff *skb;
1102 size_t total_len = iov_iter_count(from);
1103 size_t len = total_len, align = tun->align, linear;
1104 struct virtio_net_hdr gso = { 0 };
1105 int good_linear;
1106 int copylen;
1107 bool zerocopy = false;
1108 int err;
1109 u32 rxhash;
1110 ssize_t n;
1111
1112 if (!(tun->dev->flags & IFF_UP))
1113 return -EIO;
1114
1115 if (!(tun->flags & IFF_NO_PI)) {
1116 if (len < sizeof(pi))
1117 return -EINVAL;
1118 len -= sizeof(pi);
1119
1120 n = copy_from_iter(&pi, sizeof(pi), from);
1121 if (n != sizeof(pi))
1122 return -EFAULT;
1123 }
1124
1125 if (tun->flags & IFF_VNET_HDR) {
1126 if (len < tun->vnet_hdr_sz)
1127 return -EINVAL;
1128 len -= tun->vnet_hdr_sz;
1129
1130 n = copy_from_iter(&gso, sizeof(gso), from);
1131 if (n != sizeof(gso))
1132 return -EFAULT;
1133
1134 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
1135 tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2 > tun16_to_cpu(tun, gso.hdr_len))
1136 gso.hdr_len = cpu_to_tun16(tun, tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2);
1137
1138 if (tun16_to_cpu(tun, gso.hdr_len) > len)
1139 return -EINVAL;
1140 iov_iter_advance(from, tun->vnet_hdr_sz - sizeof(gso));
1141 }
1142
1143 if ((tun->flags & TUN_TYPE_MASK) == IFF_TAP) {
1144 align += NET_IP_ALIGN;
1145 if (unlikely(len < ETH_HLEN ||
1146 (gso.hdr_len && tun16_to_cpu(tun, gso.hdr_len) < ETH_HLEN)))
1147 return -EINVAL;
1148 }
1149
1150 good_linear = SKB_MAX_HEAD(align);
1151
1152 if (msg_control) {
1153 struct iov_iter i = *from;
1154
1155 /* There are 256 bytes to be copied in skb, so there is
1156 * enough room for skb expand head in case it is used.
1157 * The rest of the buffer is mapped from userspace.
1158 */
1159 copylen = gso.hdr_len ? tun16_to_cpu(tun, gso.hdr_len) : GOODCOPY_LEN;
1160 if (copylen > good_linear)
1161 copylen = good_linear;
1162 linear = copylen;
1163 iov_iter_advance(&i, copylen);
1164 if (iov_iter_npages(&i, INT_MAX) <= MAX_SKB_FRAGS)
1165 zerocopy = true;
1166 }
1167
1168 if (!zerocopy) {
1169 copylen = len;
1170 if (tun16_to_cpu(tun, gso.hdr_len) > good_linear)
1171 linear = good_linear;
1172 else
1173 linear = tun16_to_cpu(tun, gso.hdr_len);
1174 }
1175
1176 skb = tun_alloc_skb(tfile, align, copylen, linear, noblock);
1177 if (IS_ERR(skb)) {
1178 if (PTR_ERR(skb) != -EAGAIN)
1179 tun->dev->stats.rx_dropped++;
1180 return PTR_ERR(skb);
1181 }
1182
1183 if (zerocopy)
1184 err = zerocopy_sg_from_iter(skb, from);
1185 else {
1186 err = skb_copy_datagram_from_iter(skb, 0, from, len);
1187 if (!err && msg_control) {
1188 struct ubuf_info *uarg = msg_control;
1189 uarg->callback(uarg, false);
1190 }
1191 }
1192
1193 if (err) {
1194 tun->dev->stats.rx_dropped++;
1195 kfree_skb(skb);
1196 return -EFAULT;
1197 }
1198
1199 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
1200 if (!skb_partial_csum_set(skb, tun16_to_cpu(tun, gso.csum_start),
1201 tun16_to_cpu(tun, gso.csum_offset))) {
1202 tun->dev->stats.rx_frame_errors++;
1203 kfree_skb(skb);
1204 return -EINVAL;
1205 }
1206 }
1207
1208 switch (tun->flags & TUN_TYPE_MASK) {
1209 case IFF_TUN:
1210 if (tun->flags & IFF_NO_PI) {
1211 switch (skb->data[0] & 0xf0) {
1212 case 0x40:
1213 pi.proto = htons(ETH_P_IP);
1214 break;
1215 case 0x60:
1216 pi.proto = htons(ETH_P_IPV6);
1217 break;
1218 default:
1219 tun->dev->stats.rx_dropped++;
1220 kfree_skb(skb);
1221 return -EINVAL;
1222 }
1223 }
1224
1225 skb_reset_mac_header(skb);
1226 skb->protocol = pi.proto;
1227 skb->dev = tun->dev;
1228 break;
1229 case IFF_TAP:
1230 skb->protocol = eth_type_trans(skb, tun->dev);
1231 break;
1232 }
1233
1234 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
1235 pr_debug("GSO!\n");
1236 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
1237 case VIRTIO_NET_HDR_GSO_TCPV4:
1238 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
1239 break;
1240 case VIRTIO_NET_HDR_GSO_TCPV6:
1241 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
1242 break;
1243 case VIRTIO_NET_HDR_GSO_UDP:
1244 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
1245 break;
1246 default:
1247 tun->dev->stats.rx_frame_errors++;
1248 kfree_skb(skb);
1249 return -EINVAL;
1250 }
1251
1252 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
1253 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
1254
1255 skb_shinfo(skb)->gso_size = tun16_to_cpu(tun, gso.gso_size);
1256 if (skb_shinfo(skb)->gso_size == 0) {
1257 tun->dev->stats.rx_frame_errors++;
1258 kfree_skb(skb);
1259 return -EINVAL;
1260 }
1261
1262 /* Header must be checked, and gso_segs computed. */
1263 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
1264 skb_shinfo(skb)->gso_segs = 0;
1265 }
1266
1267 /* copy skb_ubuf_info for callback when skb has no error */
1268 if (zerocopy) {
1269 skb_shinfo(skb)->destructor_arg = msg_control;
1270 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1271 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
1272 }
1273
1274 skb_reset_network_header(skb);
1275 skb_probe_transport_header(skb, 0);
1276
1277 rxhash = skb_get_hash(skb);
1278 netif_rx_ni(skb);
1279
1280 tun->dev->stats.rx_packets++;
1281 tun->dev->stats.rx_bytes += len;
1282
1283 tun_flow_update(tun, rxhash, tfile);
1284 return total_len;
1285 }
1286
1287 static ssize_t tun_chr_write_iter(struct kiocb *iocb, struct iov_iter *from)
1288 {
1289 struct file *file = iocb->ki_filp;
1290 struct tun_struct *tun = tun_get(file);
1291 struct tun_file *tfile = file->private_data;
1292 ssize_t result;
1293
1294 if (!tun)
1295 return -EBADFD;
1296
1297 result = tun_get_user(tun, tfile, NULL, from, file->f_flags & O_NONBLOCK);
1298
1299 tun_put(tun);
1300 return result;
1301 }
1302
1303 /* Put packet to the user space buffer */
1304 static ssize_t tun_put_user(struct tun_struct *tun,
1305 struct tun_file *tfile,
1306 struct sk_buff *skb,
1307 struct iov_iter *iter)
1308 {
1309 struct tun_pi pi = { 0, skb->protocol };
1310 ssize_t total;
1311 int vlan_offset = 0;
1312 int vlan_hlen = 0;
1313 int vnet_hdr_sz = 0;
1314
1315 if (skb_vlan_tag_present(skb))
1316 vlan_hlen = VLAN_HLEN;
1317
1318 if (tun->flags & IFF_VNET_HDR)
1319 vnet_hdr_sz = tun->vnet_hdr_sz;
1320
1321 total = skb->len + vlan_hlen + vnet_hdr_sz;
1322
1323 if (!(tun->flags & IFF_NO_PI)) {
1324 if (iov_iter_count(iter) < sizeof(pi))
1325 return -EINVAL;
1326
1327 total += sizeof(pi);
1328 if (iov_iter_count(iter) < total) {
1329 /* Packet will be striped */
1330 pi.flags |= TUN_PKT_STRIP;
1331 }
1332
1333 if (copy_to_iter(&pi, sizeof(pi), iter) != sizeof(pi))
1334 return -EFAULT;
1335 }
1336
1337 if (vnet_hdr_sz) {
1338 struct virtio_net_hdr gso = { 0 }; /* no info leak */
1339 if (iov_iter_count(iter) < vnet_hdr_sz)
1340 return -EINVAL;
1341
1342 if (skb_is_gso(skb)) {
1343 struct skb_shared_info *sinfo = skb_shinfo(skb);
1344
1345 /* This is a hint as to how much should be linear. */
1346 gso.hdr_len = cpu_to_tun16(tun, skb_headlen(skb));
1347 gso.gso_size = cpu_to_tun16(tun, sinfo->gso_size);
1348 if (sinfo->gso_type & SKB_GSO_TCPV4)
1349 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
1350 else if (sinfo->gso_type & SKB_GSO_TCPV6)
1351 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
1352 else if (sinfo->gso_type & SKB_GSO_UDP)
1353 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
1354 else {
1355 pr_err("unexpected GSO type: "
1356 "0x%x, gso_size %d, hdr_len %d\n",
1357 sinfo->gso_type, tun16_to_cpu(tun, gso.gso_size),
1358 tun16_to_cpu(tun, gso.hdr_len));
1359 print_hex_dump(KERN_ERR, "tun: ",
1360 DUMP_PREFIX_NONE,
1361 16, 1, skb->head,
1362 min((int)tun16_to_cpu(tun, gso.hdr_len), 64), true);
1363 WARN_ON_ONCE(1);
1364 return -EINVAL;
1365 }
1366 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
1367 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
1368 } else
1369 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
1370
1371 if (skb->ip_summed == CHECKSUM_PARTIAL) {
1372 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
1373 gso.csum_start = cpu_to_tun16(tun, skb_checksum_start_offset(skb) +
1374 vlan_hlen);
1375 gso.csum_offset = cpu_to_tun16(tun, skb->csum_offset);
1376 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
1377 gso.flags = VIRTIO_NET_HDR_F_DATA_VALID;
1378 } /* else everything is zero */
1379
1380 if (copy_to_iter(&gso, sizeof(gso), iter) != sizeof(gso))
1381 return -EFAULT;
1382
1383 iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso));
1384 }
1385
1386 if (vlan_hlen) {
1387 int ret;
1388 struct {
1389 __be16 h_vlan_proto;
1390 __be16 h_vlan_TCI;
1391 } veth;
1392
1393 veth.h_vlan_proto = skb->vlan_proto;
1394 veth.h_vlan_TCI = htons(skb_vlan_tag_get(skb));
1395
1396 vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);
1397
1398 ret = skb_copy_datagram_iter(skb, 0, iter, vlan_offset);
1399 if (ret || !iov_iter_count(iter))
1400 goto done;
1401
1402 ret = copy_to_iter(&veth, sizeof(veth), iter);
1403 if (ret != sizeof(veth) || !iov_iter_count(iter))
1404 goto done;
1405 }
1406
1407 skb_copy_datagram_iter(skb, vlan_offset, iter, skb->len - vlan_offset);
1408
1409 done:
1410 tun->dev->stats.tx_packets++;
1411 tun->dev->stats.tx_bytes += skb->len + vlan_hlen;
1412
1413 return total;
1414 }
1415
1416 static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
1417 struct iov_iter *to,
1418 int noblock)
1419 {
1420 struct sk_buff *skb;
1421 ssize_t ret;
1422 int peeked, err, off = 0;
1423
1424 tun_debug(KERN_INFO, tun, "tun_do_read\n");
1425
1426 if (!iov_iter_count(to))
1427 return 0;
1428
1429 if (tun->dev->reg_state != NETREG_REGISTERED)
1430 return -EIO;
1431
1432 /* Read frames from queue */
1433 skb = __skb_recv_datagram(tfile->socket.sk, noblock ? MSG_DONTWAIT : 0,
1434 &peeked, &off, &err);
1435 if (!skb)
1436 return err;
1437
1438 ret = tun_put_user(tun, tfile, skb, to);
1439 if (unlikely(ret < 0))
1440 kfree_skb(skb);
1441 else
1442 consume_skb(skb);
1443
1444 return ret;
1445 }
1446
1447 static ssize_t tun_chr_read_iter(struct kiocb *iocb, struct iov_iter *to)
1448 {
1449 struct file *file = iocb->ki_filp;
1450 struct tun_file *tfile = file->private_data;
1451 struct tun_struct *tun = __tun_get(tfile);
1452 ssize_t len = iov_iter_count(to), ret;
1453
1454 if (!tun)
1455 return -EBADFD;
1456 ret = tun_do_read(tun, tfile, to, file->f_flags & O_NONBLOCK);
1457 ret = min_t(ssize_t, ret, len);
1458 if (ret > 0)
1459 iocb->ki_pos = ret;
1460 tun_put(tun);
1461 return ret;
1462 }
1463
1464 static void tun_free_netdev(struct net_device *dev)
1465 {
1466 struct tun_struct *tun = netdev_priv(dev);
1467
1468 BUG_ON(!(list_empty(&tun->disabled)));
1469 tun_flow_uninit(tun);
1470 security_tun_dev_free_security(tun->security);
1471 free_netdev(dev);
1472 }
1473
1474 static void tun_setup(struct net_device *dev)
1475 {
1476 struct tun_struct *tun = netdev_priv(dev);
1477
1478 tun->owner = INVALID_UID;
1479 tun->group = INVALID_GID;
1480
1481 dev->ethtool_ops = &tun_ethtool_ops;
1482 dev->destructor = tun_free_netdev;
1483 }
1484
1485 /* Trivial set of netlink ops to allow deleting tun or tap
1486 * device with netlink.
1487 */
1488 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
1489 {
1490 return -EINVAL;
1491 }
1492
1493 static struct rtnl_link_ops tun_link_ops __read_mostly = {
1494 .kind = DRV_NAME,
1495 .priv_size = sizeof(struct tun_struct),
1496 .setup = tun_setup,
1497 .validate = tun_validate,
1498 };
1499
1500 static void tun_sock_write_space(struct sock *sk)
1501 {
1502 struct tun_file *tfile;
1503 wait_queue_head_t *wqueue;
1504
1505 if (!sock_writeable(sk))
1506 return;
1507
1508 if (!test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags))
1509 return;
1510
1511 wqueue = sk_sleep(sk);
1512 if (wqueue && waitqueue_active(wqueue))
1513 wake_up_interruptible_sync_poll(wqueue, POLLOUT |
1514 POLLWRNORM | POLLWRBAND);
1515
1516 tfile = container_of(sk, struct tun_file, sk);
1517 kill_fasync(&tfile->fasync, SIGIO, POLL_OUT);
1518 }
1519
1520 static int tun_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
1521 {
1522 int ret;
1523 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1524 struct tun_struct *tun = __tun_get(tfile);
1525
1526 if (!tun)
1527 return -EBADFD;
1528
1529 ret = tun_get_user(tun, tfile, m->msg_control, &m->msg_iter,
1530 m->msg_flags & MSG_DONTWAIT);
1531 tun_put(tun);
1532 return ret;
1533 }
1534
1535 static int tun_recvmsg(struct socket *sock, struct msghdr *m, size_t total_len,
1536 int flags)
1537 {
1538 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1539 struct tun_struct *tun = __tun_get(tfile);
1540 int ret;
1541
1542 if (!tun)
1543 return -EBADFD;
1544
1545 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC|MSG_ERRQUEUE)) {
1546 ret = -EINVAL;
1547 goto out;
1548 }
1549 if (flags & MSG_ERRQUEUE) {
1550 ret = sock_recv_errqueue(sock->sk, m, total_len,
1551 SOL_PACKET, TUN_TX_TIMESTAMP);
1552 goto out;
1553 }
1554 ret = tun_do_read(tun, tfile, &m->msg_iter, flags & MSG_DONTWAIT);
1555 if (ret > (ssize_t)total_len) {
1556 m->msg_flags |= MSG_TRUNC;
1557 ret = flags & MSG_TRUNC ? ret : total_len;
1558 }
1559 out:
1560 tun_put(tun);
1561 return ret;
1562 }
1563
1564 /* Ops structure to mimic raw sockets with tun */
1565 static const struct proto_ops tun_socket_ops = {
1566 .sendmsg = tun_sendmsg,
1567 .recvmsg = tun_recvmsg,
1568 };
1569
1570 static struct proto tun_proto = {
1571 .name = "tun",
1572 .owner = THIS_MODULE,
1573 .obj_size = sizeof(struct tun_file),
1574 };
1575
1576 static int tun_flags(struct tun_struct *tun)
1577 {
1578 return tun->flags & (TUN_FEATURES | IFF_PERSIST | IFF_TUN | IFF_TAP);
1579 }
1580
1581 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
1582 char *buf)
1583 {
1584 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1585 return sprintf(buf, "0x%x\n", tun_flags(tun));
1586 }
1587
1588 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
1589 char *buf)
1590 {
1591 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1592 return uid_valid(tun->owner)?
1593 sprintf(buf, "%u\n",
1594 from_kuid_munged(current_user_ns(), tun->owner)):
1595 sprintf(buf, "-1\n");
1596 }
1597
1598 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
1599 char *buf)
1600 {
1601 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1602 return gid_valid(tun->group) ?
1603 sprintf(buf, "%u\n",
1604 from_kgid_munged(current_user_ns(), tun->group)):
1605 sprintf(buf, "-1\n");
1606 }
1607
1608 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
1609 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
1610 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
1611
1612 static struct attribute *tun_dev_attrs[] = {
1613 &dev_attr_tun_flags.attr,
1614 &dev_attr_owner.attr,
1615 &dev_attr_group.attr,
1616 NULL
1617 };
1618
1619 static const struct attribute_group tun_attr_group = {
1620 .attrs = tun_dev_attrs
1621 };
1622
1623 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
1624 {
1625 struct tun_struct *tun;
1626 struct tun_file *tfile = file->private_data;
1627 struct net_device *dev;
1628 int err;
1629
1630 if (tfile->detached)
1631 return -EINVAL;
1632
1633 dev = __dev_get_by_name(net, ifr->ifr_name);
1634 if (dev) {
1635 if (ifr->ifr_flags & IFF_TUN_EXCL)
1636 return -EBUSY;
1637 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
1638 tun = netdev_priv(dev);
1639 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
1640 tun = netdev_priv(dev);
1641 else
1642 return -EINVAL;
1643
1644 if (!!(ifr->ifr_flags & IFF_MULTI_QUEUE) !=
1645 !!(tun->flags & IFF_MULTI_QUEUE))
1646 return -EINVAL;
1647
1648 if (tun_not_capable(tun))
1649 return -EPERM;
1650 err = security_tun_dev_open(tun->security);
1651 if (err < 0)
1652 return err;
1653
1654 err = tun_attach(tun, file, ifr->ifr_flags & IFF_NOFILTER);
1655 if (err < 0)
1656 return err;
1657
1658 if (tun->flags & IFF_MULTI_QUEUE &&
1659 (tun->numqueues + tun->numdisabled > 1)) {
1660 /* One or more queue has already been attached, no need
1661 * to initialize the device again.
1662 */
1663 return 0;
1664 }
1665 }
1666 else {
1667 char *name;
1668 unsigned long flags = 0;
1669 int queues = ifr->ifr_flags & IFF_MULTI_QUEUE ?
1670 MAX_TAP_QUEUES : 1;
1671
1672 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1673 return -EPERM;
1674 err = security_tun_dev_create();
1675 if (err < 0)
1676 return err;
1677
1678 /* Set dev type */
1679 if (ifr->ifr_flags & IFF_TUN) {
1680 /* TUN device */
1681 flags |= IFF_TUN;
1682 name = "tun%d";
1683 } else if (ifr->ifr_flags & IFF_TAP) {
1684 /* TAP device */
1685 flags |= IFF_TAP;
1686 name = "tap%d";
1687 } else
1688 return -EINVAL;
1689
1690 if (*ifr->ifr_name)
1691 name = ifr->ifr_name;
1692
1693 dev = alloc_netdev_mqs(sizeof(struct tun_struct), name,
1694 NET_NAME_UNKNOWN, tun_setup, queues,
1695 queues);
1696
1697 if (!dev)
1698 return -ENOMEM;
1699
1700 dev_net_set(dev, net);
1701 dev->rtnl_link_ops = &tun_link_ops;
1702 dev->ifindex = tfile->ifindex;
1703 dev->sysfs_groups[0] = &tun_attr_group;
1704
1705 tun = netdev_priv(dev);
1706 tun->dev = dev;
1707 tun->flags = flags;
1708 tun->txflt.count = 0;
1709 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
1710
1711 tun->align = NET_SKB_PAD;
1712 tun->filter_attached = false;
1713 tun->sndbuf = tfile->socket.sk->sk_sndbuf;
1714
1715 spin_lock_init(&tun->lock);
1716
1717 err = security_tun_dev_alloc_security(&tun->security);
1718 if (err < 0)
1719 goto err_free_dev;
1720
1721 tun_net_init(dev);
1722 tun_flow_init(tun);
1723
1724 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
1725 TUN_USER_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
1726 NETIF_F_HW_VLAN_STAG_TX;
1727 dev->features = dev->hw_features;
1728 dev->vlan_features = dev->features &
1729 ~(NETIF_F_HW_VLAN_CTAG_TX |
1730 NETIF_F_HW_VLAN_STAG_TX);
1731
1732 INIT_LIST_HEAD(&tun->disabled);
1733 err = tun_attach(tun, file, false);
1734 if (err < 0)
1735 goto err_free_flow;
1736
1737 err = register_netdevice(tun->dev);
1738 if (err < 0)
1739 goto err_detach;
1740 }
1741
1742 netif_carrier_on(tun->dev);
1743
1744 tun_debug(KERN_INFO, tun, "tun_set_iff\n");
1745
1746 tun->flags = (tun->flags & ~TUN_FEATURES) |
1747 (ifr->ifr_flags & TUN_FEATURES);
1748
1749 /* Make sure persistent devices do not get stuck in
1750 * xoff state.
1751 */
1752 if (netif_running(tun->dev))
1753 netif_tx_wake_all_queues(tun->dev);
1754
1755 strcpy(ifr->ifr_name, tun->dev->name);
1756 return 0;
1757
1758 err_detach:
1759 tun_detach_all(dev);
1760 err_free_flow:
1761 tun_flow_uninit(tun);
1762 security_tun_dev_free_security(tun->security);
1763 err_free_dev:
1764 free_netdev(dev);
1765 return err;
1766 }
1767
1768 static void tun_get_iff(struct net *net, struct tun_struct *tun,
1769 struct ifreq *ifr)
1770 {
1771 tun_debug(KERN_INFO, tun, "tun_get_iff\n");
1772
1773 strcpy(ifr->ifr_name, tun->dev->name);
1774
1775 ifr->ifr_flags = tun_flags(tun);
1776
1777 }
1778
1779 /* This is like a cut-down ethtool ops, except done via tun fd so no
1780 * privs required. */
1781 static int set_offload(struct tun_struct *tun, unsigned long arg)
1782 {
1783 netdev_features_t features = 0;
1784
1785 if (arg & TUN_F_CSUM) {
1786 features |= NETIF_F_HW_CSUM;
1787 arg &= ~TUN_F_CSUM;
1788
1789 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1790 if (arg & TUN_F_TSO_ECN) {
1791 features |= NETIF_F_TSO_ECN;
1792 arg &= ~TUN_F_TSO_ECN;
1793 }
1794 if (arg & TUN_F_TSO4)
1795 features |= NETIF_F_TSO;
1796 if (arg & TUN_F_TSO6)
1797 features |= NETIF_F_TSO6;
1798 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1799 }
1800
1801 if (arg & TUN_F_UFO) {
1802 features |= NETIF_F_UFO;
1803 arg &= ~TUN_F_UFO;
1804 }
1805 }
1806
1807 /* This gives the user a way to test for new features in future by
1808 * trying to set them. */
1809 if (arg)
1810 return -EINVAL;
1811
1812 tun->set_features = features;
1813 netdev_update_features(tun->dev);
1814
1815 return 0;
1816 }
1817
1818 static void tun_detach_filter(struct tun_struct *tun, int n)
1819 {
1820 int i;
1821 struct tun_file *tfile;
1822
1823 for (i = 0; i < n; i++) {
1824 tfile = rtnl_dereference(tun->tfiles[i]);
1825 sk_detach_filter(tfile->socket.sk);
1826 }
1827
1828 tun->filter_attached = false;
1829 }
1830
1831 static int tun_attach_filter(struct tun_struct *tun)
1832 {
1833 int i, ret = 0;
1834 struct tun_file *tfile;
1835
1836 for (i = 0; i < tun->numqueues; i++) {
1837 tfile = rtnl_dereference(tun->tfiles[i]);
1838 ret = sk_attach_filter(&tun->fprog, tfile->socket.sk);
1839 if (ret) {
1840 tun_detach_filter(tun, i);
1841 return ret;
1842 }
1843 }
1844
1845 tun->filter_attached = true;
1846 return ret;
1847 }
1848
1849 static void tun_set_sndbuf(struct tun_struct *tun)
1850 {
1851 struct tun_file *tfile;
1852 int i;
1853
1854 for (i = 0; i < tun->numqueues; i++) {
1855 tfile = rtnl_dereference(tun->tfiles[i]);
1856 tfile->socket.sk->sk_sndbuf = tun->sndbuf;
1857 }
1858 }
1859
1860 static int tun_set_queue(struct file *file, struct ifreq *ifr)
1861 {
1862 struct tun_file *tfile = file->private_data;
1863 struct tun_struct *tun;
1864 int ret = 0;
1865
1866 rtnl_lock();
1867
1868 if (ifr->ifr_flags & IFF_ATTACH_QUEUE) {
1869 tun = tfile->detached;
1870 if (!tun) {
1871 ret = -EINVAL;
1872 goto unlock;
1873 }
1874 ret = security_tun_dev_attach_queue(tun->security);
1875 if (ret < 0)
1876 goto unlock;
1877 ret = tun_attach(tun, file, false);
1878 } else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
1879 tun = rtnl_dereference(tfile->tun);
1880 if (!tun || !(tun->flags & IFF_MULTI_QUEUE) || tfile->detached)
1881 ret = -EINVAL;
1882 else
1883 __tun_detach(tfile, false);
1884 } else
1885 ret = -EINVAL;
1886
1887 unlock:
1888 rtnl_unlock();
1889 return ret;
1890 }
1891
1892 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
1893 unsigned long arg, int ifreq_len)
1894 {
1895 struct tun_file *tfile = file->private_data;
1896 struct tun_struct *tun;
1897 void __user* argp = (void __user*)arg;
1898 struct ifreq ifr;
1899 kuid_t owner;
1900 kgid_t group;
1901 int sndbuf;
1902 int vnet_hdr_sz;
1903 unsigned int ifindex;
1904 int le;
1905 int ret;
1906
1907 if (cmd == TUNSETIFF || cmd == TUNSETQUEUE || _IOC_TYPE(cmd) == 0x89) {
1908 if (copy_from_user(&ifr, argp, ifreq_len))
1909 return -EFAULT;
1910 } else {
1911 memset(&ifr, 0, sizeof(ifr));
1912 }
1913 if (cmd == TUNGETFEATURES) {
1914 /* Currently this just means: "what IFF flags are valid?".
1915 * This is needed because we never checked for invalid flags on
1916 * TUNSETIFF.
1917 */
1918 return put_user(IFF_TUN | IFF_TAP | TUN_FEATURES,
1919 (unsigned int __user*)argp);
1920 } else if (cmd == TUNSETQUEUE)
1921 return tun_set_queue(file, &ifr);
1922
1923 ret = 0;
1924 rtnl_lock();
1925
1926 tun = __tun_get(tfile);
1927 if (cmd == TUNSETIFF && !tun) {
1928 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1929
1930 ret = tun_set_iff(sock_net(&tfile->sk), file, &ifr);
1931
1932 if (ret)
1933 goto unlock;
1934
1935 if (copy_to_user(argp, &ifr, ifreq_len))
1936 ret = -EFAULT;
1937 goto unlock;
1938 }
1939 if (cmd == TUNSETIFINDEX) {
1940 ret = -EPERM;
1941 if (tun)
1942 goto unlock;
1943
1944 ret = -EFAULT;
1945 if (copy_from_user(&ifindex, argp, sizeof(ifindex)))
1946 goto unlock;
1947
1948 ret = 0;
1949 tfile->ifindex = ifindex;
1950 goto unlock;
1951 }
1952
1953 ret = -EBADFD;
1954 if (!tun)
1955 goto unlock;
1956
1957 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %u\n", cmd);
1958
1959 ret = 0;
1960 switch (cmd) {
1961 case TUNGETIFF:
1962 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1963
1964 if (tfile->detached)
1965 ifr.ifr_flags |= IFF_DETACH_QUEUE;
1966 if (!tfile->socket.sk->sk_filter)
1967 ifr.ifr_flags |= IFF_NOFILTER;
1968
1969 if (copy_to_user(argp, &ifr, ifreq_len))
1970 ret = -EFAULT;
1971 break;
1972
1973 case TUNSETNOCSUM:
1974 /* Disable/Enable checksum */
1975
1976 /* [unimplemented] */
1977 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n",
1978 arg ? "disabled" : "enabled");
1979 break;
1980
1981 case TUNSETPERSIST:
1982 /* Disable/Enable persist mode. Keep an extra reference to the
1983 * module to prevent the module being unprobed.
1984 */
1985 if (arg && !(tun->flags & IFF_PERSIST)) {
1986 tun->flags |= IFF_PERSIST;
1987 __module_get(THIS_MODULE);
1988 }
1989 if (!arg && (tun->flags & IFF_PERSIST)) {
1990 tun->flags &= ~IFF_PERSIST;
1991 module_put(THIS_MODULE);
1992 }
1993
1994 tun_debug(KERN_INFO, tun, "persist %s\n",
1995 arg ? "enabled" : "disabled");
1996 break;
1997
1998 case TUNSETOWNER:
1999 /* Set owner of the device */
2000 owner = make_kuid(current_user_ns(), arg);
2001 if (!uid_valid(owner)) {
2002 ret = -EINVAL;
2003 break;
2004 }
2005 tun->owner = owner;
2006 tun_debug(KERN_INFO, tun, "owner set to %u\n",
2007 from_kuid(&init_user_ns, tun->owner));
2008 break;
2009
2010 case TUNSETGROUP:
2011 /* Set group of the device */
2012 group = make_kgid(current_user_ns(), arg);
2013 if (!gid_valid(group)) {
2014 ret = -EINVAL;
2015 break;
2016 }
2017 tun->group = group;
2018 tun_debug(KERN_INFO, tun, "group set to %u\n",
2019 from_kgid(&init_user_ns, tun->group));
2020 break;
2021
2022 case TUNSETLINK:
2023 /* Only allow setting the type when the interface is down */
2024 if (tun->dev->flags & IFF_UP) {
2025 tun_debug(KERN_INFO, tun,
2026 "Linktype set failed because interface is up\n");
2027 ret = -EBUSY;
2028 } else {
2029 tun->dev->type = (int) arg;
2030 tun_debug(KERN_INFO, tun, "linktype set to %d\n",
2031 tun->dev->type);
2032 ret = 0;
2033 }
2034 break;
2035
2036 #ifdef TUN_DEBUG
2037 case TUNSETDEBUG:
2038 tun->debug = arg;
2039 break;
2040 #endif
2041 case TUNSETOFFLOAD:
2042 ret = set_offload(tun, arg);
2043 break;
2044
2045 case TUNSETTXFILTER:
2046 /* Can be set only for TAPs */
2047 ret = -EINVAL;
2048 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2049 break;
2050 ret = update_filter(&tun->txflt, (void __user *)arg);
2051 break;
2052
2053 case SIOCGIFHWADDR:
2054 /* Get hw address */
2055 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
2056 ifr.ifr_hwaddr.sa_family = tun->dev->type;
2057 if (copy_to_user(argp, &ifr, ifreq_len))
2058 ret = -EFAULT;
2059 break;
2060
2061 case SIOCSIFHWADDR:
2062 /* Set hw address */
2063 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
2064 ifr.ifr_hwaddr.sa_data);
2065
2066 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
2067 break;
2068
2069 case TUNGETSNDBUF:
2070 sndbuf = tfile->socket.sk->sk_sndbuf;
2071 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
2072 ret = -EFAULT;
2073 break;
2074
2075 case TUNSETSNDBUF:
2076 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
2077 ret = -EFAULT;
2078 break;
2079 }
2080
2081 tun->sndbuf = sndbuf;
2082 tun_set_sndbuf(tun);
2083 break;
2084
2085 case TUNGETVNETHDRSZ:
2086 vnet_hdr_sz = tun->vnet_hdr_sz;
2087 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
2088 ret = -EFAULT;
2089 break;
2090
2091 case TUNSETVNETHDRSZ:
2092 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
2093 ret = -EFAULT;
2094 break;
2095 }
2096 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
2097 ret = -EINVAL;
2098 break;
2099 }
2100
2101 tun->vnet_hdr_sz = vnet_hdr_sz;
2102 break;
2103
2104 case TUNGETVNETLE:
2105 le = !!(tun->flags & TUN_VNET_LE);
2106 if (put_user(le, (int __user *)argp))
2107 ret = -EFAULT;
2108 break;
2109
2110 case TUNSETVNETLE:
2111 if (get_user(le, (int __user *)argp)) {
2112 ret = -EFAULT;
2113 break;
2114 }
2115 if (le)
2116 tun->flags |= TUN_VNET_LE;
2117 else
2118 tun->flags &= ~TUN_VNET_LE;
2119 break;
2120
2121 case TUNGETVNETBE:
2122 ret = tun_get_vnet_be(tun, argp);
2123 break;
2124
2125 case TUNSETVNETBE:
2126 ret = tun_set_vnet_be(tun, argp);
2127 break;
2128
2129 case TUNATTACHFILTER:
2130 /* Can be set only for TAPs */
2131 ret = -EINVAL;
2132 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2133 break;
2134 ret = -EFAULT;
2135 if (copy_from_user(&tun->fprog, argp, sizeof(tun->fprog)))
2136 break;
2137
2138 ret = tun_attach_filter(tun);
2139 break;
2140
2141 case TUNDETACHFILTER:
2142 /* Can be set only for TAPs */
2143 ret = -EINVAL;
2144 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2145 break;
2146 ret = 0;
2147 tun_detach_filter(tun, tun->numqueues);
2148 break;
2149
2150 case TUNGETFILTER:
2151 ret = -EINVAL;
2152 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2153 break;
2154 ret = -EFAULT;
2155 if (copy_to_user(argp, &tun->fprog, sizeof(tun->fprog)))
2156 break;
2157 ret = 0;
2158 break;
2159
2160 default:
2161 ret = -EINVAL;
2162 break;
2163 }
2164
2165 unlock:
2166 rtnl_unlock();
2167 if (tun)
2168 tun_put(tun);
2169 return ret;
2170 }
2171
2172 static long tun_chr_ioctl(struct file *file,
2173 unsigned int cmd, unsigned long arg)
2174 {
2175 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
2176 }
2177
2178 #ifdef CONFIG_COMPAT
2179 static long tun_chr_compat_ioctl(struct file *file,
2180 unsigned int cmd, unsigned long arg)
2181 {
2182 switch (cmd) {
2183 case TUNSETIFF:
2184 case TUNGETIFF:
2185 case TUNSETTXFILTER:
2186 case TUNGETSNDBUF:
2187 case TUNSETSNDBUF:
2188 case SIOCGIFHWADDR:
2189 case SIOCSIFHWADDR:
2190 arg = (unsigned long)compat_ptr(arg);
2191 break;
2192 default:
2193 arg = (compat_ulong_t)arg;
2194 break;
2195 }
2196
2197 /*
2198 * compat_ifreq is shorter than ifreq, so we must not access beyond
2199 * the end of that structure. All fields that are used in this
2200 * driver are compatible though, we don't need to convert the
2201 * contents.
2202 */
2203 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
2204 }
2205 #endif /* CONFIG_COMPAT */
2206
2207 static int tun_chr_fasync(int fd, struct file *file, int on)
2208 {
2209 struct tun_file *tfile = file->private_data;
2210 int ret;
2211
2212 if ((ret = fasync_helper(fd, file, on, &tfile->fasync)) < 0)
2213 goto out;
2214
2215 if (on) {
2216 __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
2217 tfile->flags |= TUN_FASYNC;
2218 } else
2219 tfile->flags &= ~TUN_FASYNC;
2220 ret = 0;
2221 out:
2222 return ret;
2223 }
2224
2225 static int tun_chr_open(struct inode *inode, struct file * file)
2226 {
2227 struct net *net = current->nsproxy->net_ns;
2228 struct tun_file *tfile;
2229
2230 DBG1(KERN_INFO, "tunX: tun_chr_open\n");
2231
2232 tfile = (struct tun_file *)sk_alloc(net, AF_UNSPEC, GFP_KERNEL,
2233 &tun_proto, 0);
2234 if (!tfile)
2235 return -ENOMEM;
2236 RCU_INIT_POINTER(tfile->tun, NULL);
2237 tfile->flags = 0;
2238 tfile->ifindex = 0;
2239
2240 init_waitqueue_head(&tfile->wq.wait);
2241 RCU_INIT_POINTER(tfile->socket.wq, &tfile->wq);
2242
2243 tfile->socket.file = file;
2244 tfile->socket.ops = &tun_socket_ops;
2245
2246 sock_init_data(&tfile->socket, &tfile->sk);
2247
2248 tfile->sk.sk_write_space = tun_sock_write_space;
2249 tfile->sk.sk_sndbuf = INT_MAX;
2250
2251 file->private_data = tfile;
2252 INIT_LIST_HEAD(&tfile->next);
2253
2254 sock_set_flag(&tfile->sk, SOCK_ZEROCOPY);
2255
2256 return 0;
2257 }
2258
2259 static int tun_chr_close(struct inode *inode, struct file *file)
2260 {
2261 struct tun_file *tfile = file->private_data;
2262
2263 tun_detach(tfile, true);
2264
2265 return 0;
2266 }
2267
2268 #ifdef CONFIG_PROC_FS
2269 static void tun_chr_show_fdinfo(struct seq_file *m, struct file *f)
2270 {
2271 struct tun_struct *tun;
2272 struct ifreq ifr;
2273
2274 memset(&ifr, 0, sizeof(ifr));
2275
2276 rtnl_lock();
2277 tun = tun_get(f);
2278 if (tun)
2279 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
2280 rtnl_unlock();
2281
2282 if (tun)
2283 tun_put(tun);
2284
2285 seq_printf(m, "iff:\t%s\n", ifr.ifr_name);
2286 }
2287 #endif
2288
2289 static const struct file_operations tun_fops = {
2290 .owner = THIS_MODULE,
2291 .llseek = no_llseek,
2292 .read_iter = tun_chr_read_iter,
2293 .write_iter = tun_chr_write_iter,
2294 .poll = tun_chr_poll,
2295 .unlocked_ioctl = tun_chr_ioctl,
2296 #ifdef CONFIG_COMPAT
2297 .compat_ioctl = tun_chr_compat_ioctl,
2298 #endif
2299 .open = tun_chr_open,
2300 .release = tun_chr_close,
2301 .fasync = tun_chr_fasync,
2302 #ifdef CONFIG_PROC_FS
2303 .show_fdinfo = tun_chr_show_fdinfo,
2304 #endif
2305 };
2306
2307 static struct miscdevice tun_miscdev = {
2308 .minor = TUN_MINOR,
2309 .name = "tun",
2310 .nodename = "net/tun",
2311 .fops = &tun_fops,
2312 };
2313
2314 /* ethtool interface */
2315
2316 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
2317 {
2318 cmd->supported = 0;
2319 cmd->advertising = 0;
2320 ethtool_cmd_speed_set(cmd, SPEED_10);
2321 cmd->duplex = DUPLEX_FULL;
2322 cmd->port = PORT_TP;
2323 cmd->phy_address = 0;
2324 cmd->transceiver = XCVR_INTERNAL;
2325 cmd->autoneg = AUTONEG_DISABLE;
2326 cmd->maxtxpkt = 0;
2327 cmd->maxrxpkt = 0;
2328 return 0;
2329 }
2330
2331 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
2332 {
2333 struct tun_struct *tun = netdev_priv(dev);
2334
2335 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
2336 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
2337
2338 switch (tun->flags & TUN_TYPE_MASK) {
2339 case IFF_TUN:
2340 strlcpy(info->bus_info, "tun", sizeof(info->bus_info));
2341 break;
2342 case IFF_TAP:
2343 strlcpy(info->bus_info, "tap", sizeof(info->bus_info));
2344 break;
2345 }
2346 }
2347
2348 static u32 tun_get_msglevel(struct net_device *dev)
2349 {
2350 #ifdef TUN_DEBUG
2351 struct tun_struct *tun = netdev_priv(dev);
2352 return tun->debug;
2353 #else
2354 return -EOPNOTSUPP;
2355 #endif
2356 }
2357
2358 static void tun_set_msglevel(struct net_device *dev, u32 value)
2359 {
2360 #ifdef TUN_DEBUG
2361 struct tun_struct *tun = netdev_priv(dev);
2362 tun->debug = value;
2363 #endif
2364 }
2365
2366 static const struct ethtool_ops tun_ethtool_ops = {
2367 .get_settings = tun_get_settings,
2368 .get_drvinfo = tun_get_drvinfo,
2369 .get_msglevel = tun_get_msglevel,
2370 .set_msglevel = tun_set_msglevel,
2371 .get_link = ethtool_op_get_link,
2372 .get_ts_info = ethtool_op_get_ts_info,
2373 };
2374
2375
2376 static int __init tun_init(void)
2377 {
2378 int ret = 0;
2379
2380 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
2381 pr_info("%s\n", DRV_COPYRIGHT);
2382
2383 ret = rtnl_link_register(&tun_link_ops);
2384 if (ret) {
2385 pr_err("Can't register link_ops\n");
2386 goto err_linkops;
2387 }
2388
2389 ret = misc_register(&tun_miscdev);
2390 if (ret) {
2391 pr_err("Can't register misc device %d\n", TUN_MINOR);
2392 goto err_misc;
2393 }
2394 return 0;
2395 err_misc:
2396 rtnl_link_unregister(&tun_link_ops);
2397 err_linkops:
2398 return ret;
2399 }
2400
2401 static void tun_cleanup(void)
2402 {
2403 misc_deregister(&tun_miscdev);
2404 rtnl_link_unregister(&tun_link_ops);
2405 }
2406
2407 /* Get an underlying socket object from tun file. Returns error unless file is
2408 * attached to a device. The returned object works like a packet socket, it
2409 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
2410 * holding a reference to the file for as long as the socket is in use. */
2411 struct socket *tun_get_socket(struct file *file)
2412 {
2413 struct tun_file *tfile;
2414 if (file->f_op != &tun_fops)
2415 return ERR_PTR(-EINVAL);
2416 tfile = file->private_data;
2417 if (!tfile)
2418 return ERR_PTR(-EBADFD);
2419 return &tfile->socket;
2420 }
2421 EXPORT_SYMBOL_GPL(tun_get_socket);
2422
2423 module_init(tun_init);
2424 module_exit(tun_cleanup);
2425 MODULE_DESCRIPTION(DRV_DESCRIPTION);
2426 MODULE_AUTHOR(DRV_COPYRIGHT);
2427 MODULE_LICENSE("GPL");
2428 MODULE_ALIAS_MISCDEV(TUN_MINOR);
2429 MODULE_ALIAS("devname:net/tun");
Linux with added FPC-III support