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tuntap: forbid calling TUNSETIFF when detached
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / net / tun.c
bloba36b56f0940bd9b2718c3ff522c1b6f2c5bc972e
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/crc32.h>
64 #include <linux/nsproxy.h>
65 #include <linux/virtio_net.h>
66 #include <linux/rcupdate.h>
67 #include <net/net_namespace.h>
68 #include <net/netns/generic.h>
69 #include <net/rtnetlink.h>
70 #include <net/sock.h>
71
72 #include <asm/uaccess.h>
73
74 /* Uncomment to enable debugging */
75 /* #define TUN_DEBUG 1 */
76
77 #ifdef TUN_DEBUG
78 static int debug;
79
80 #define tun_debug(level, tun, fmt, args...) \
81 do { \
82 if (tun->debug) \
83 netdev_printk(level, tun->dev, fmt, ##args); \
84 } while (0)
85 #define DBG1(level, fmt, args...) \
86 do { \
87 if (debug == 2) \
88 printk(level fmt, ##args); \
89 } while (0)
90 #else
91 #define tun_debug(level, tun, fmt, args...) \
92 do { \
93 if (0) \
94 netdev_printk(level, tun->dev, fmt, ##args); \
95 } while (0)
96 #define DBG1(level, fmt, args...) \
97 do { \
98 if (0) \
99 printk(level fmt, ##args); \
100 } while (0)
101 #endif
102
103 #define GOODCOPY_LEN 128
104
105 #define FLT_EXACT_COUNT 8
106 struct tap_filter {
107 unsigned int count; /* Number of addrs. Zero means disabled */
108 u32 mask[2]; /* Mask of the hashed addrs */
109 unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN];
110 };
111
112 /* 1024 is probably a high enough limit: modern hypervisors seem to support on
113 * the order of 100-200 CPUs so this leaves us some breathing space if we want
114 * to match a queue per guest CPU.
115 */
116 #define MAX_TAP_QUEUES 1024
117
118 #define TUN_FLOW_EXPIRE (3 * HZ)
119
120 /* A tun_file connects an open character device to a tuntap netdevice. It
121 * also contains all socket related strctures (except sock_fprog and tap_filter)
122 * to serve as one transmit queue for tuntap device. The sock_fprog and
123 * tap_filter were kept in tun_struct since they were used for filtering for the
124 * netdevice not for a specific queue (at least I didn't see the requirement for
125 * this).
126 *
127 * RCU usage:
128 * The tun_file and tun_struct are loosely coupled, the pointer from one to the
129 * other can only be read while rcu_read_lock or rtnl_lock is held.
130 */
131 struct tun_file {
132 struct sock sk;
133 struct socket socket;
134 struct socket_wq wq;
135 struct tun_struct __rcu *tun;
136 struct net *net;
137 struct fasync_struct *fasync;
138 /* only used for fasnyc */
139 unsigned int flags;
140 u16 queue_index;
141 struct list_head next;
142 struct tun_struct *detached;
143 };
144
145 struct tun_flow_entry {
146 struct hlist_node hash_link;
147 struct rcu_head rcu;
148 struct tun_struct *tun;
149
150 u32 rxhash;
151 int queue_index;
152 unsigned long updated;
153 };
154
155 #define TUN_NUM_FLOW_ENTRIES 1024
156
157 /* Since the socket were moved to tun_file, to preserve the behavior of persist
158 * device, socket filter, sndbuf and vnet header size were restore when the
159 * file were attached to a persist device.
160 */
161 struct tun_struct {
162 struct tun_file __rcu *tfiles[MAX_TAP_QUEUES];
163 unsigned int numqueues;
164 unsigned int flags;
165 kuid_t owner;
166 kgid_t group;
167
168 struct net_device *dev;
169 netdev_features_t set_features;
170 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
171 NETIF_F_TSO6|NETIF_F_UFO)
172
173 int vnet_hdr_sz;
174 int sndbuf;
175 struct tap_filter txflt;
176 struct sock_fprog fprog;
177 /* protected by rtnl lock */
178 bool filter_attached;
179 #ifdef TUN_DEBUG
180 int debug;
181 #endif
182 spinlock_t lock;
183 struct hlist_head flows[TUN_NUM_FLOW_ENTRIES];
184 struct timer_list flow_gc_timer;
185 unsigned long ageing_time;
186 unsigned int numdisabled;
187 struct list_head disabled;
188 };
189
190 static inline u32 tun_hashfn(u32 rxhash)
191 {
192 return rxhash & 0x3ff;
193 }
194
195 static struct tun_flow_entry *tun_flow_find(struct hlist_head *head, u32 rxhash)
196 {
197 struct tun_flow_entry *e;
198 struct hlist_node *n;
199
200 hlist_for_each_entry_rcu(e, n, head, hash_link) {
201 if (e->rxhash == rxhash)
202 return e;
203 }
204 return NULL;
205 }
206
207 static struct tun_flow_entry *tun_flow_create(struct tun_struct *tun,
208 struct hlist_head *head,
209 u32 rxhash, u16 queue_index)
210 {
211 struct tun_flow_entry *e = kmalloc(sizeof(*e), GFP_ATOMIC);
212
213 if (e) {
214 tun_debug(KERN_INFO, tun, "create flow: hash %u index %u\n",
215 rxhash, queue_index);
216 e->updated = jiffies;
217 e->rxhash = rxhash;
218 e->queue_index = queue_index;
219 e->tun = tun;
220 hlist_add_head_rcu(&e->hash_link, head);
221 }
222 return e;
223 }
224
225 static void tun_flow_delete(struct tun_struct *tun, struct tun_flow_entry *e)
226 {
227 tun_debug(KERN_INFO, tun, "delete flow: hash %u index %u\n",
228 e->rxhash, e->queue_index);
229 hlist_del_rcu(&e->hash_link);
230 kfree_rcu(e, rcu);
231 }
232
233 static void tun_flow_flush(struct tun_struct *tun)
234 {
235 int i;
236
237 spin_lock_bh(&tun->lock);
238 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
239 struct tun_flow_entry *e;
240 struct hlist_node *h, *n;
241
242 hlist_for_each_entry_safe(e, h, n, &tun->flows[i], hash_link)
243 tun_flow_delete(tun, e);
244 }
245 spin_unlock_bh(&tun->lock);
246 }
247
248 static void tun_flow_delete_by_queue(struct tun_struct *tun, u16 queue_index)
249 {
250 int i;
251
252 spin_lock_bh(&tun->lock);
253 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
254 struct tun_flow_entry *e;
255 struct hlist_node *h, *n;
256
257 hlist_for_each_entry_safe(e, h, n, &tun->flows[i], hash_link) {
258 if (e->queue_index == queue_index)
259 tun_flow_delete(tun, e);
260 }
261 }
262 spin_unlock_bh(&tun->lock);
263 }
264
265 static void tun_flow_cleanup(unsigned long data)
266 {
267 struct tun_struct *tun = (struct tun_struct *)data;
268 unsigned long delay = tun->ageing_time;
269 unsigned long next_timer = jiffies + delay;
270 unsigned long count = 0;
271 int i;
272
273 tun_debug(KERN_INFO, tun, "tun_flow_cleanup\n");
274
275 spin_lock_bh(&tun->lock);
276 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
277 struct tun_flow_entry *e;
278 struct hlist_node *h, *n;
279
280 hlist_for_each_entry_safe(e, h, n, &tun->flows[i], hash_link) {
281 unsigned long this_timer;
282 count++;
283 this_timer = e->updated + delay;
284 if (time_before_eq(this_timer, jiffies))
285 tun_flow_delete(tun, e);
286 else if (time_before(this_timer, next_timer))
287 next_timer = this_timer;
288 }
289 }
290
291 if (count)
292 mod_timer(&tun->flow_gc_timer, round_jiffies_up(next_timer));
293 spin_unlock_bh(&tun->lock);
294 }
295
296 static void tun_flow_update(struct tun_struct *tun, u32 rxhash,
297 u16 queue_index)
298 {
299 struct hlist_head *head;
300 struct tun_flow_entry *e;
301 unsigned long delay = tun->ageing_time;
302
303 if (!rxhash)
304 return;
305 else
306 head = &tun->flows[tun_hashfn(rxhash)];
307
308 rcu_read_lock();
309
310 if (tun->numqueues == 1)
311 goto unlock;
312
313 e = tun_flow_find(head, rxhash);
314 if (likely(e)) {
315 /* TODO: keep queueing to old queue until it's empty? */
316 e->queue_index = queue_index;
317 e->updated = jiffies;
318 } else {
319 spin_lock_bh(&tun->lock);
320 if (!tun_flow_find(head, rxhash))
321 tun_flow_create(tun, head, rxhash, queue_index);
322
323 if (!timer_pending(&tun->flow_gc_timer))
324 mod_timer(&tun->flow_gc_timer,
325 round_jiffies_up(jiffies + delay));
326 spin_unlock_bh(&tun->lock);
327 }
328
329 unlock:
330 rcu_read_unlock();
331 }
332
333 /* We try to identify a flow through its rxhash first. The reason that
334 * we do not check rxq no. is becuase some cards(e.g 82599), chooses
335 * the rxq based on the txq where the last packet of the flow comes. As
336 * the userspace application move between processors, we may get a
337 * different rxq no. here. If we could not get rxhash, then we would
338 * hope the rxq no. may help here.
339 */
340 static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb)
341 {
342 struct tun_struct *tun = netdev_priv(dev);
343 struct tun_flow_entry *e;
344 u32 txq = 0;
345 u32 numqueues = 0;
346
347 rcu_read_lock();
348 numqueues = tun->numqueues;
349
350 txq = skb_get_rxhash(skb);
351 if (txq) {
352 e = tun_flow_find(&tun->flows[tun_hashfn(txq)], txq);
353 if (e)
354 txq = e->queue_index;
355 else
356 /* use multiply and shift instead of expensive divide */
357 txq = ((u64)txq * numqueues) >> 32;
358 } else if (likely(skb_rx_queue_recorded(skb))) {
359 txq = skb_get_rx_queue(skb);
360 while (unlikely(txq >= numqueues))
361 txq -= numqueues;
362 }
363
364 rcu_read_unlock();
365 return txq;
366 }
367
368 static inline bool tun_not_capable(struct tun_struct *tun)
369 {
370 const struct cred *cred = current_cred();
371 struct net *net = dev_net(tun->dev);
372
373 return ((uid_valid(tun->owner) && !uid_eq(cred->euid, tun->owner)) ||
374 (gid_valid(tun->group) && !in_egroup_p(tun->group))) &&
375 !ns_capable(net->user_ns, CAP_NET_ADMIN);
376 }
377
378 static void tun_set_real_num_queues(struct tun_struct *tun)
379 {
380 netif_set_real_num_tx_queues(tun->dev, tun->numqueues);
381 netif_set_real_num_rx_queues(tun->dev, tun->numqueues);
382 }
383
384 static void tun_disable_queue(struct tun_struct *tun, struct tun_file *tfile)
385 {
386 tfile->detached = tun;
387 list_add_tail(&tfile->next, &tun->disabled);
388 ++tun->numdisabled;
389 }
390
391 static struct tun_struct *tun_enable_queue(struct tun_file *tfile)
392 {
393 struct tun_struct *tun = tfile->detached;
394
395 tfile->detached = NULL;
396 list_del_init(&tfile->next);
397 --tun->numdisabled;
398 return tun;
399 }
400
401 static void __tun_detach(struct tun_file *tfile, bool clean)
402 {
403 struct tun_file *ntfile;
404 struct tun_struct *tun;
405 struct net_device *dev;
406
407 tun = rtnl_dereference(tfile->tun);
408
409 if (tun) {
410 u16 index = tfile->queue_index;
411 BUG_ON(index >= tun->numqueues);
412 dev = tun->dev;
413
414 rcu_assign_pointer(tun->tfiles[index],
415 tun->tfiles[tun->numqueues - 1]);
416 rcu_assign_pointer(tfile->tun, NULL);
417 ntfile = rtnl_dereference(tun->tfiles[index]);
418 ntfile->queue_index = index;
419
420 --tun->numqueues;
421 if (clean)
422 sock_put(&tfile->sk);
423 else
424 tun_disable_queue(tun, tfile);
425
426 synchronize_net();
427 tun_flow_delete_by_queue(tun, tun->numqueues + 1);
428 /* Drop read queue */
429 skb_queue_purge(&tfile->sk.sk_receive_queue);
430 tun_set_real_num_queues(tun);
431 } else if (tfile->detached && clean)
432 tun = tun_enable_queue(tfile);
433
434 if (clean) {
435 if (tun && tun->numqueues == 0 && tun->numdisabled == 0 &&
436 !(tun->flags & TUN_PERSIST))
437 if (tun->dev->reg_state == NETREG_REGISTERED)
438 unregister_netdevice(tun->dev);
439
440 BUG_ON(!test_bit(SOCK_EXTERNALLY_ALLOCATED,
441 &tfile->socket.flags));
442 sk_release_kernel(&tfile->sk);
443 }
444 }
445
446 static void tun_detach(struct tun_file *tfile, bool clean)
447 {
448 rtnl_lock();
449 __tun_detach(tfile, clean);
450 rtnl_unlock();
451 }
452
453 static void tun_detach_all(struct net_device *dev)
454 {
455 struct tun_struct *tun = netdev_priv(dev);
456 struct tun_file *tfile, *tmp;
457 int i, n = tun->numqueues;
458
459 for (i = 0; i < n; i++) {
460 tfile = rtnl_dereference(tun->tfiles[i]);
461 BUG_ON(!tfile);
462 wake_up_all(&tfile->wq.wait);
463 rcu_assign_pointer(tfile->tun, NULL);
464 --tun->numqueues;
465 }
466 BUG_ON(tun->numqueues != 0);
467
468 synchronize_net();
469 for (i = 0; i < n; i++) {
470 tfile = rtnl_dereference(tun->tfiles[i]);
471 /* Drop read queue */
472 skb_queue_purge(&tfile->sk.sk_receive_queue);
473 sock_put(&tfile->sk);
474 }
475 list_for_each_entry_safe(tfile, tmp, &tun->disabled, next) {
476 tun_enable_queue(tfile);
477 skb_queue_purge(&tfile->sk.sk_receive_queue);
478 sock_put(&tfile->sk);
479 }
480 BUG_ON(tun->numdisabled != 0);
481 }
482
483 static int tun_attach(struct tun_struct *tun, struct file *file)
484 {
485 struct tun_file *tfile = file->private_data;
486 int err;
487
488 err = -EINVAL;
489 if (rtnl_dereference(tfile->tun))
490 goto out;
491
492 err = -EBUSY;
493 if (!(tun->flags & TUN_TAP_MQ) && tun->numqueues == 1)
494 goto out;
495
496 err = -E2BIG;
497 if (!tfile->detached &&
498 tun->numqueues + tun->numdisabled == MAX_TAP_QUEUES)
499 goto out;
500
501 err = 0;
502
503 /* Re-attach the filter to presist device */
504 if (tun->filter_attached == true) {
505 err = sk_attach_filter(&tun->fprog, tfile->socket.sk);
506 if (!err)
507 goto out;
508 }
509 tfile->queue_index = tun->numqueues;
510 rcu_assign_pointer(tfile->tun, tun);
511 rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile);
512 tun->numqueues++;
513
514 if (tfile->detached)
515 tun_enable_queue(tfile);
516 else
517 sock_hold(&tfile->sk);
518
519 tun_set_real_num_queues(tun);
520
521 /* device is allowed to go away first, so no need to hold extra
522 * refcnt.
523 */
524
525 out:
526 return err;
527 }
528
529 static struct tun_struct *__tun_get(struct tun_file *tfile)
530 {
531 struct tun_struct *tun;
532
533 rcu_read_lock();
534 tun = rcu_dereference(tfile->tun);
535 if (tun)
536 dev_hold(tun->dev);
537 rcu_read_unlock();
538
539 return tun;
540 }
541
542 static struct tun_struct *tun_get(struct file *file)
543 {
544 return __tun_get(file->private_data);
545 }
546
547 static void tun_put(struct tun_struct *tun)
548 {
549 dev_put(tun->dev);
550 }
551
552 /* TAP filtering */
553 static void addr_hash_set(u32 *mask, const u8 *addr)
554 {
555 int n = ether_crc(ETH_ALEN, addr) >> 26;
556 mask[n >> 5] |= (1 << (n & 31));
557 }
558
559 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
560 {
561 int n = ether_crc(ETH_ALEN, addr) >> 26;
562 return mask[n >> 5] & (1 << (n & 31));
563 }
564
565 static int update_filter(struct tap_filter *filter, void __user *arg)
566 {
567 struct { u8 u[ETH_ALEN]; } *addr;
568 struct tun_filter uf;
569 int err, alen, n, nexact;
570
571 if (copy_from_user(&uf, arg, sizeof(uf)))
572 return -EFAULT;
573
574 if (!uf.count) {
575 /* Disabled */
576 filter->count = 0;
577 return 0;
578 }
579
580 alen = ETH_ALEN * uf.count;
581 addr = kmalloc(alen, GFP_KERNEL);
582 if (!addr)
583 return -ENOMEM;
584
585 if (copy_from_user(addr, arg + sizeof(uf), alen)) {
586 err = -EFAULT;
587 goto done;
588 }
589
590 /* The filter is updated without holding any locks. Which is
591 * perfectly safe. We disable it first and in the worst
592 * case we'll accept a few undesired packets. */
593 filter->count = 0;
594 wmb();
595
596 /* Use first set of addresses as an exact filter */
597 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
598 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
599
600 nexact = n;
601
602 /* Remaining multicast addresses are hashed,
603 * unicast will leave the filter disabled. */
604 memset(filter->mask, 0, sizeof(filter->mask));
605 for (; n < uf.count; n++) {
606 if (!is_multicast_ether_addr(addr[n].u)) {
607 err = 0; /* no filter */
608 goto done;
609 }
610 addr_hash_set(filter->mask, addr[n].u);
611 }
612
613 /* For ALLMULTI just set the mask to all ones.
614 * This overrides the mask populated above. */
615 if ((uf.flags & TUN_FLT_ALLMULTI))
616 memset(filter->mask, ~0, sizeof(filter->mask));
617
618 /* Now enable the filter */
619 wmb();
620 filter->count = nexact;
621
622 /* Return the number of exact filters */
623 err = nexact;
624
625 done:
626 kfree(addr);
627 return err;
628 }
629
630 /* Returns: 0 - drop, !=0 - accept */
631 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
632 {
633 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
634 * at this point. */
635 struct ethhdr *eh = (struct ethhdr *) skb->data;
636 int i;
637
638 /* Exact match */
639 for (i = 0; i < filter->count; i++)
640 if (ether_addr_equal(eh->h_dest, filter->addr[i]))
641 return 1;
642
643 /* Inexact match (multicast only) */
644 if (is_multicast_ether_addr(eh->h_dest))
645 return addr_hash_test(filter->mask, eh->h_dest);
646
647 return 0;
648 }
649
650 /*
651 * Checks whether the packet is accepted or not.
652 * Returns: 0 - drop, !=0 - accept
653 */
654 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
655 {
656 if (!filter->count)
657 return 1;
658
659 return run_filter(filter, skb);
660 }
661
662 /* Network device part of the driver */
663
664 static const struct ethtool_ops tun_ethtool_ops;
665
666 /* Net device detach from fd. */
667 static void tun_net_uninit(struct net_device *dev)
668 {
669 tun_detach_all(dev);
670 }
671
672 /* Net device open. */
673 static int tun_net_open(struct net_device *dev)
674 {
675 netif_tx_start_all_queues(dev);
676 return 0;
677 }
678
679 /* Net device close. */
680 static int tun_net_close(struct net_device *dev)
681 {
682 netif_tx_stop_all_queues(dev);
683 return 0;
684 }
685
686 /* Net device start xmit */
687 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
688 {
689 struct tun_struct *tun = netdev_priv(dev);
690 int txq = skb->queue_mapping;
691 struct tun_file *tfile;
692
693 rcu_read_lock();
694 tfile = rcu_dereference(tun->tfiles[txq]);
695
696 /* Drop packet if interface is not attached */
697 if (txq >= tun->numqueues)
698 goto drop;
699
700 tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len);
701
702 BUG_ON(!tfile);
703
704 /* Drop if the filter does not like it.
705 * This is a noop if the filter is disabled.
706 * Filter can be enabled only for the TAP devices. */
707 if (!check_filter(&tun->txflt, skb))
708 goto drop;
709
710 if (tfile->socket.sk->sk_filter &&
711 sk_filter(tfile->socket.sk, skb))
712 goto drop;
713
714 /* Limit the number of packets queued by dividing txq length with the
715 * number of queues.
716 */
717 if (skb_queue_len(&tfile->socket.sk->sk_receive_queue)
718 >= dev->tx_queue_len / tun->numqueues)
719 goto drop;
720
721 /* Orphan the skb - required as we might hang on to it
722 * for indefinite time. */
723 if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
724 goto drop;
725 skb_orphan(skb);
726
727 /* Enqueue packet */
728 skb_queue_tail(&tfile->socket.sk->sk_receive_queue, skb);
729
730 /* Notify and wake up reader process */
731 if (tfile->flags & TUN_FASYNC)
732 kill_fasync(&tfile->fasync, SIGIO, POLL_IN);
733 wake_up_interruptible_poll(&tfile->wq.wait, POLLIN |
734 POLLRDNORM | POLLRDBAND);
735
736 rcu_read_unlock();
737 return NETDEV_TX_OK;
738
739 drop:
740 dev->stats.tx_dropped++;
741 skb_tx_error(skb);
742 kfree_skb(skb);
743 rcu_read_unlock();
744 return NETDEV_TX_OK;
745 }
746
747 static void tun_net_mclist(struct net_device *dev)
748 {
749 /*
750 * This callback is supposed to deal with mc filter in
751 * _rx_ path and has nothing to do with the _tx_ path.
752 * In rx path we always accept everything userspace gives us.
753 */
754 }
755
756 #define MIN_MTU 68
757 #define MAX_MTU 65535
758
759 static int
760 tun_net_change_mtu(struct net_device *dev, int new_mtu)
761 {
762 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
763 return -EINVAL;
764 dev->mtu = new_mtu;
765 return 0;
766 }
767
768 static netdev_features_t tun_net_fix_features(struct net_device *dev,
769 netdev_features_t features)
770 {
771 struct tun_struct *tun = netdev_priv(dev);
772
773 return (features & tun->set_features) | (features & ~TUN_USER_FEATURES);
774 }
775 #ifdef CONFIG_NET_POLL_CONTROLLER
776 static void tun_poll_controller(struct net_device *dev)
777 {
778 /*
779 * Tun only receives frames when:
780 * 1) the char device endpoint gets data from user space
781 * 2) the tun socket gets a sendmsg call from user space
782 * Since both of those are syncronous operations, we are guaranteed
783 * never to have pending data when we poll for it
784 * so theres nothing to do here but return.
785 * We need this though so netpoll recognizes us as an interface that
786 * supports polling, which enables bridge devices in virt setups to
787 * still use netconsole
788 */
789 return;
790 }
791 #endif
792 static const struct net_device_ops tun_netdev_ops = {
793 .ndo_uninit = tun_net_uninit,
794 .ndo_open = tun_net_open,
795 .ndo_stop = tun_net_close,
796 .ndo_start_xmit = tun_net_xmit,
797 .ndo_change_mtu = tun_net_change_mtu,
798 .ndo_fix_features = tun_net_fix_features,
799 .ndo_select_queue = tun_select_queue,
800 #ifdef CONFIG_NET_POLL_CONTROLLER
801 .ndo_poll_controller = tun_poll_controller,
802 #endif
803 };
804
805 static const struct net_device_ops tap_netdev_ops = {
806 .ndo_uninit = tun_net_uninit,
807 .ndo_open = tun_net_open,
808 .ndo_stop = tun_net_close,
809 .ndo_start_xmit = tun_net_xmit,
810 .ndo_change_mtu = tun_net_change_mtu,
811 .ndo_fix_features = tun_net_fix_features,
812 .ndo_set_rx_mode = tun_net_mclist,
813 .ndo_set_mac_address = eth_mac_addr,
814 .ndo_validate_addr = eth_validate_addr,
815 .ndo_select_queue = tun_select_queue,
816 #ifdef CONFIG_NET_POLL_CONTROLLER
817 .ndo_poll_controller = tun_poll_controller,
818 #endif
819 };
820
821 static int tun_flow_init(struct tun_struct *tun)
822 {
823 int i;
824
825 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++)
826 INIT_HLIST_HEAD(&tun->flows[i]);
827
828 tun->ageing_time = TUN_FLOW_EXPIRE;
829 setup_timer(&tun->flow_gc_timer, tun_flow_cleanup, (unsigned long)tun);
830 mod_timer(&tun->flow_gc_timer,
831 round_jiffies_up(jiffies + tun->ageing_time));
832
833 return 0;
834 }
835
836 static void tun_flow_uninit(struct tun_struct *tun)
837 {
838 del_timer_sync(&tun->flow_gc_timer);
839 tun_flow_flush(tun);
840 }
841
842 /* Initialize net device. */
843 static void tun_net_init(struct net_device *dev)
844 {
845 struct tun_struct *tun = netdev_priv(dev);
846
847 switch (tun->flags & TUN_TYPE_MASK) {
848 case TUN_TUN_DEV:
849 dev->netdev_ops = &tun_netdev_ops;
850
851 /* Point-to-Point TUN Device */
852 dev->hard_header_len = 0;
853 dev->addr_len = 0;
854 dev->mtu = 1500;
855
856 /* Zero header length */
857 dev->type = ARPHRD_NONE;
858 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
859 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
860 break;
861
862 case TUN_TAP_DEV:
863 dev->netdev_ops = &tap_netdev_ops;
864 /* Ethernet TAP Device */
865 ether_setup(dev);
866 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
867 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
868
869 eth_hw_addr_random(dev);
870
871 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
872 break;
873 }
874 }
875
876 /* Character device part */
877
878 /* Poll */
879 static unsigned int tun_chr_poll(struct file *file, poll_table *wait)
880 {
881 struct tun_file *tfile = file->private_data;
882 struct tun_struct *tun = __tun_get(tfile);
883 struct sock *sk;
884 unsigned int mask = 0;
885
886 if (!tun)
887 return POLLERR;
888
889 sk = tfile->socket.sk;
890
891 tun_debug(KERN_INFO, tun, "tun_chr_poll\n");
892
893 poll_wait(file, &tfile->wq.wait, wait);
894
895 if (!skb_queue_empty(&sk->sk_receive_queue))
896 mask |= POLLIN | POLLRDNORM;
897
898 if (sock_writeable(sk) ||
899 (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
900 sock_writeable(sk)))
901 mask |= POLLOUT | POLLWRNORM;
902
903 if (tun->dev->reg_state != NETREG_REGISTERED)
904 mask = POLLERR;
905
906 tun_put(tun);
907 return mask;
908 }
909
910 /* prepad is the amount to reserve at front. len is length after that.
911 * linear is a hint as to how much to copy (usually headers). */
912 static struct sk_buff *tun_alloc_skb(struct tun_file *tfile,
913 size_t prepad, size_t len,
914 size_t linear, int noblock)
915 {
916 struct sock *sk = tfile->socket.sk;
917 struct sk_buff *skb;
918 int err;
919
920 /* Under a page? Don't bother with paged skb. */
921 if (prepad + len < PAGE_SIZE || !linear)
922 linear = len;
923
924 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
925 &err);
926 if (!skb)
927 return ERR_PTR(err);
928
929 skb_reserve(skb, prepad);
930 skb_put(skb, linear);
931 skb->data_len = len - linear;
932 skb->len += len - linear;
933
934 return skb;
935 }
936
937 /* set skb frags from iovec, this can move to core network code for reuse */
938 static int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *from,
939 int offset, size_t count)
940 {
941 int len = iov_length(from, count) - offset;
942 int copy = skb_headlen(skb);
943 int size, offset1 = 0;
944 int i = 0;
945
946 /* Skip over from offset */
947 while (count && (offset >= from->iov_len)) {
948 offset -= from->iov_len;
949 ++from;
950 --count;
951 }
952
953 /* copy up to skb headlen */
954 while (count && (copy > 0)) {
955 size = min_t(unsigned int, copy, from->iov_len - offset);
956 if (copy_from_user(skb->data + offset1, from->iov_base + offset,
957 size))
958 return -EFAULT;
959 if (copy > size) {
960 ++from;
961 --count;
962 offset = 0;
963 } else
964 offset += size;
965 copy -= size;
966 offset1 += size;
967 }
968
969 if (len == offset1)
970 return 0;
971
972 while (count--) {
973 struct page *page[MAX_SKB_FRAGS];
974 int num_pages;
975 unsigned long base;
976 unsigned long truesize;
977
978 len = from->iov_len - offset;
979 if (!len) {
980 offset = 0;
981 ++from;
982 continue;
983 }
984 base = (unsigned long)from->iov_base + offset;
985 size = ((base & ~PAGE_MASK) + len + ~PAGE_MASK) >> PAGE_SHIFT;
986 if (i + size > MAX_SKB_FRAGS)
987 return -EMSGSIZE;
988 num_pages = get_user_pages_fast(base, size, 0, &page[i]);
989 if (num_pages != size) {
990 for (i = 0; i < num_pages; i++)
991 put_page(page[i]);
992 return -EFAULT;
993 }
994 truesize = size * PAGE_SIZE;
995 skb->data_len += len;
996 skb->len += len;
997 skb->truesize += truesize;
998 atomic_add(truesize, &skb->sk->sk_wmem_alloc);
999 while (len) {
1000 int off = base & ~PAGE_MASK;
1001 int size = min_t(int, len, PAGE_SIZE - off);
1002 __skb_fill_page_desc(skb, i, page[i], off, size);
1003 skb_shinfo(skb)->nr_frags++;
1004 /* increase sk_wmem_alloc */
1005 base += size;
1006 len -= size;
1007 i++;
1008 }
1009 offset = 0;
1010 ++from;
1011 }
1012 return 0;
1013 }
1014
1015 /* Get packet from user space buffer */
1016 static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
1017 void *msg_control, const struct iovec *iv,
1018 size_t total_len, size_t count, int noblock)
1019 {
1020 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
1021 struct sk_buff *skb;
1022 size_t len = total_len, align = NET_SKB_PAD;
1023 struct virtio_net_hdr gso = { 0 };
1024 int offset = 0;
1025 int copylen;
1026 bool zerocopy = false;
1027 int err;
1028 u32 rxhash;
1029
1030 if (!(tun->flags & TUN_NO_PI)) {
1031 if ((len -= sizeof(pi)) > total_len)
1032 return -EINVAL;
1033
1034 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
1035 return -EFAULT;
1036 offset += sizeof(pi);
1037 }
1038
1039 if (tun->flags & TUN_VNET_HDR) {
1040 if ((len -= tun->vnet_hdr_sz) > total_len)
1041 return -EINVAL;
1042
1043 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
1044 return -EFAULT;
1045
1046 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
1047 gso.csum_start + gso.csum_offset + 2 > gso.hdr_len)
1048 gso.hdr_len = gso.csum_start + gso.csum_offset + 2;
1049
1050 if (gso.hdr_len > len)
1051 return -EINVAL;
1052 offset += tun->vnet_hdr_sz;
1053 }
1054
1055 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
1056 align += NET_IP_ALIGN;
1057 if (unlikely(len < ETH_HLEN ||
1058 (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
1059 return -EINVAL;
1060 }
1061
1062 if (msg_control)
1063 zerocopy = true;
1064
1065 if (zerocopy) {
1066 /* Userspace may produce vectors with count greater than
1067 * MAX_SKB_FRAGS, so we need to linearize parts of the skb
1068 * to let the rest of data to be fit in the frags.
1069 */
1070 if (count > MAX_SKB_FRAGS) {
1071 copylen = iov_length(iv, count - MAX_SKB_FRAGS);
1072 if (copylen < offset)
1073 copylen = 0;
1074 else
1075 copylen -= offset;
1076 } else
1077 copylen = 0;
1078 /* There are 256 bytes to be copied in skb, so there is enough
1079 * room for skb expand head in case it is used.
1080 * The rest of the buffer is mapped from userspace.
1081 */
1082 if (copylen < gso.hdr_len)
1083 copylen = gso.hdr_len;
1084 if (!copylen)
1085 copylen = GOODCOPY_LEN;
1086 } else
1087 copylen = len;
1088
1089 skb = tun_alloc_skb(tfile, align, copylen, gso.hdr_len, noblock);
1090 if (IS_ERR(skb)) {
1091 if (PTR_ERR(skb) != -EAGAIN)
1092 tun->dev->stats.rx_dropped++;
1093 return PTR_ERR(skb);
1094 }
1095
1096 if (zerocopy)
1097 err = zerocopy_sg_from_iovec(skb, iv, offset, count);
1098 else
1099 err = skb_copy_datagram_from_iovec(skb, 0, iv, offset, len);
1100
1101 if (err) {
1102 tun->dev->stats.rx_dropped++;
1103 kfree_skb(skb);
1104 return -EFAULT;
1105 }
1106
1107 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
1108 if (!skb_partial_csum_set(skb, gso.csum_start,
1109 gso.csum_offset)) {
1110 tun->dev->stats.rx_frame_errors++;
1111 kfree_skb(skb);
1112 return -EINVAL;
1113 }
1114 }
1115
1116 switch (tun->flags & TUN_TYPE_MASK) {
1117 case TUN_TUN_DEV:
1118 if (tun->flags & TUN_NO_PI) {
1119 switch (skb->data[0] & 0xf0) {
1120 case 0x40:
1121 pi.proto = htons(ETH_P_IP);
1122 break;
1123 case 0x60:
1124 pi.proto = htons(ETH_P_IPV6);
1125 break;
1126 default:
1127 tun->dev->stats.rx_dropped++;
1128 kfree_skb(skb);
1129 return -EINVAL;
1130 }
1131 }
1132
1133 skb_reset_mac_header(skb);
1134 skb->protocol = pi.proto;
1135 skb->dev = tun->dev;
1136 break;
1137 case TUN_TAP_DEV:
1138 skb->protocol = eth_type_trans(skb, tun->dev);
1139 break;
1140 }
1141
1142 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
1143 pr_debug("GSO!\n");
1144 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
1145 case VIRTIO_NET_HDR_GSO_TCPV4:
1146 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
1147 break;
1148 case VIRTIO_NET_HDR_GSO_TCPV6:
1149 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
1150 break;
1151 case VIRTIO_NET_HDR_GSO_UDP:
1152 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
1153 break;
1154 default:
1155 tun->dev->stats.rx_frame_errors++;
1156 kfree_skb(skb);
1157 return -EINVAL;
1158 }
1159
1160 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
1161 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
1162
1163 skb_shinfo(skb)->gso_size = gso.gso_size;
1164 if (skb_shinfo(skb)->gso_size == 0) {
1165 tun->dev->stats.rx_frame_errors++;
1166 kfree_skb(skb);
1167 return -EINVAL;
1168 }
1169
1170 /* Header must be checked, and gso_segs computed. */
1171 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
1172 skb_shinfo(skb)->gso_segs = 0;
1173 }
1174
1175 /* copy skb_ubuf_info for callback when skb has no error */
1176 if (zerocopy) {
1177 skb_shinfo(skb)->destructor_arg = msg_control;
1178 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1179 }
1180
1181 skb_reset_network_header(skb);
1182 rxhash = skb_get_rxhash(skb);
1183 netif_rx_ni(skb);
1184
1185 tun->dev->stats.rx_packets++;
1186 tun->dev->stats.rx_bytes += len;
1187
1188 tun_flow_update(tun, rxhash, tfile->queue_index);
1189 return total_len;
1190 }
1191
1192 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
1193 unsigned long count, loff_t pos)
1194 {
1195 struct file *file = iocb->ki_filp;
1196 struct tun_struct *tun = tun_get(file);
1197 struct tun_file *tfile = file->private_data;
1198 ssize_t result;
1199
1200 if (!tun)
1201 return -EBADFD;
1202
1203 tun_debug(KERN_INFO, tun, "tun_chr_write %ld\n", count);
1204
1205 result = tun_get_user(tun, tfile, NULL, iv, iov_length(iv, count),
1206 count, file->f_flags & O_NONBLOCK);
1207
1208 tun_put(tun);
1209 return result;
1210 }
1211
1212 /* Put packet to the user space buffer */
1213 static ssize_t tun_put_user(struct tun_struct *tun,
1214 struct tun_file *tfile,
1215 struct sk_buff *skb,
1216 const struct iovec *iv, int len)
1217 {
1218 struct tun_pi pi = { 0, skb->protocol };
1219 ssize_t total = 0;
1220
1221 if (!(tun->flags & TUN_NO_PI)) {
1222 if ((len -= sizeof(pi)) < 0)
1223 return -EINVAL;
1224
1225 if (len < skb->len) {
1226 /* Packet will be striped */
1227 pi.flags |= TUN_PKT_STRIP;
1228 }
1229
1230 if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi)))
1231 return -EFAULT;
1232 total += sizeof(pi);
1233 }
1234
1235 if (tun->flags & TUN_VNET_HDR) {
1236 struct virtio_net_hdr gso = { 0 }; /* no info leak */
1237 if ((len -= tun->vnet_hdr_sz) < 0)
1238 return -EINVAL;
1239
1240 if (skb_is_gso(skb)) {
1241 struct skb_shared_info *sinfo = skb_shinfo(skb);
1242
1243 /* This is a hint as to how much should be linear. */
1244 gso.hdr_len = skb_headlen(skb);
1245 gso.gso_size = sinfo->gso_size;
1246 if (sinfo->gso_type & SKB_GSO_TCPV4)
1247 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
1248 else if (sinfo->gso_type & SKB_GSO_TCPV6)
1249 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
1250 else if (sinfo->gso_type & SKB_GSO_UDP)
1251 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
1252 else {
1253 pr_err("unexpected GSO type: "
1254 "0x%x, gso_size %d, hdr_len %d\n",
1255 sinfo->gso_type, gso.gso_size,
1256 gso.hdr_len);
1257 print_hex_dump(KERN_ERR, "tun: ",
1258 DUMP_PREFIX_NONE,
1259 16, 1, skb->head,
1260 min((int)gso.hdr_len, 64), true);
1261 WARN_ON_ONCE(1);
1262 return -EINVAL;
1263 }
1264 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
1265 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
1266 } else
1267 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
1268
1269 if (skb->ip_summed == CHECKSUM_PARTIAL) {
1270 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
1271 gso.csum_start = skb_checksum_start_offset(skb);
1272 gso.csum_offset = skb->csum_offset;
1273 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
1274 gso.flags = VIRTIO_NET_HDR_F_DATA_VALID;
1275 } /* else everything is zero */
1276
1277 if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
1278 sizeof(gso))))
1279 return -EFAULT;
1280 total += tun->vnet_hdr_sz;
1281 }
1282
1283 len = min_t(int, skb->len, len);
1284
1285 skb_copy_datagram_const_iovec(skb, 0, iv, total, len);
1286 total += skb->len;
1287
1288 tun->dev->stats.tx_packets++;
1289 tun->dev->stats.tx_bytes += len;
1290
1291 return total;
1292 }
1293
1294 static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
1295 struct kiocb *iocb, const struct iovec *iv,
1296 ssize_t len, int noblock)
1297 {
1298 DECLARE_WAITQUEUE(wait, current);
1299 struct sk_buff *skb;
1300 ssize_t ret = 0;
1301
1302 tun_debug(KERN_INFO, tun, "tun_do_read\n");
1303
1304 if (unlikely(!noblock))
1305 add_wait_queue(&tfile->wq.wait, &wait);
1306 while (len) {
1307 current->state = TASK_INTERRUPTIBLE;
1308
1309 /* Read frames from the queue */
1310 if (!(skb = skb_dequeue(&tfile->socket.sk->sk_receive_queue))) {
1311 if (noblock) {
1312 ret = -EAGAIN;
1313 break;
1314 }
1315 if (signal_pending(current)) {
1316 ret = -ERESTARTSYS;
1317 break;
1318 }
1319 if (tun->dev->reg_state != NETREG_REGISTERED) {
1320 ret = -EIO;
1321 break;
1322 }
1323
1324 /* Nothing to read, let's sleep */
1325 schedule();
1326 continue;
1327 }
1328
1329 ret = tun_put_user(tun, tfile, skb, iv, len);
1330 kfree_skb(skb);
1331 break;
1332 }
1333
1334 current->state = TASK_RUNNING;
1335 if (unlikely(!noblock))
1336 remove_wait_queue(&tfile->wq.wait, &wait);
1337
1338 return ret;
1339 }
1340
1341 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
1342 unsigned long count, loff_t pos)
1343 {
1344 struct file *file = iocb->ki_filp;
1345 struct tun_file *tfile = file->private_data;
1346 struct tun_struct *tun = __tun_get(tfile);
1347 ssize_t len, ret;
1348
1349 if (!tun)
1350 return -EBADFD;
1351 len = iov_length(iv, count);
1352 if (len < 0) {
1353 ret = -EINVAL;
1354 goto out;
1355 }
1356
1357 ret = tun_do_read(tun, tfile, iocb, iv, len,
1358 file->f_flags & O_NONBLOCK);
1359 ret = min_t(ssize_t, ret, len);
1360 out:
1361 tun_put(tun);
1362 return ret;
1363 }
1364
1365 static void tun_free_netdev(struct net_device *dev)
1366 {
1367 struct tun_struct *tun = netdev_priv(dev);
1368
1369 BUG_ON(!(list_empty(&tun->disabled)));
1370 tun_flow_uninit(tun);
1371 free_netdev(dev);
1372 }
1373
1374 static void tun_setup(struct net_device *dev)
1375 {
1376 struct tun_struct *tun = netdev_priv(dev);
1377
1378 tun->owner = INVALID_UID;
1379 tun->group = INVALID_GID;
1380
1381 dev->ethtool_ops = &tun_ethtool_ops;
1382 dev->destructor = tun_free_netdev;
1383 }
1384
1385 /* Trivial set of netlink ops to allow deleting tun or tap
1386 * device with netlink.
1387 */
1388 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
1389 {
1390 return -EINVAL;
1391 }
1392
1393 static struct rtnl_link_ops tun_link_ops __read_mostly = {
1394 .kind = DRV_NAME,
1395 .priv_size = sizeof(struct tun_struct),
1396 .setup = tun_setup,
1397 .validate = tun_validate,
1398 };
1399
1400 static void tun_sock_write_space(struct sock *sk)
1401 {
1402 struct tun_file *tfile;
1403 wait_queue_head_t *wqueue;
1404
1405 if (!sock_writeable(sk))
1406 return;
1407
1408 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
1409 return;
1410
1411 wqueue = sk_sleep(sk);
1412 if (wqueue && waitqueue_active(wqueue))
1413 wake_up_interruptible_sync_poll(wqueue, POLLOUT |
1414 POLLWRNORM | POLLWRBAND);
1415
1416 tfile = container_of(sk, struct tun_file, sk);
1417 kill_fasync(&tfile->fasync, SIGIO, POLL_OUT);
1418 }
1419
1420 static int tun_sendmsg(struct kiocb *iocb, struct socket *sock,
1421 struct msghdr *m, size_t total_len)
1422 {
1423 int ret;
1424 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1425 struct tun_struct *tun = __tun_get(tfile);
1426
1427 if (!tun)
1428 return -EBADFD;
1429 ret = tun_get_user(tun, tfile, m->msg_control, m->msg_iov, total_len,
1430 m->msg_iovlen, m->msg_flags & MSG_DONTWAIT);
1431 tun_put(tun);
1432 return ret;
1433 }
1434
1435
1436 static int tun_recvmsg(struct kiocb *iocb, struct socket *sock,
1437 struct msghdr *m, size_t total_len,
1438 int flags)
1439 {
1440 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1441 struct tun_struct *tun = __tun_get(tfile);
1442 int ret;
1443
1444 if (!tun)
1445 return -EBADFD;
1446
1447 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))
1448 return -EINVAL;
1449 ret = tun_do_read(tun, tfile, iocb, m->msg_iov, total_len,
1450 flags & MSG_DONTWAIT);
1451 if (ret > total_len) {
1452 m->msg_flags |= MSG_TRUNC;
1453 ret = flags & MSG_TRUNC ? ret : total_len;
1454 }
1455 tun_put(tun);
1456 return ret;
1457 }
1458
1459 static int tun_release(struct socket *sock)
1460 {
1461 if (sock->sk)
1462 sock_put(sock->sk);
1463 return 0;
1464 }
1465
1466 /* Ops structure to mimic raw sockets with tun */
1467 static const struct proto_ops tun_socket_ops = {
1468 .sendmsg = tun_sendmsg,
1469 .recvmsg = tun_recvmsg,
1470 .release = tun_release,
1471 };
1472
1473 static struct proto tun_proto = {
1474 .name = "tun",
1475 .owner = THIS_MODULE,
1476 .obj_size = sizeof(struct tun_file),
1477 };
1478
1479 static int tun_flags(struct tun_struct *tun)
1480 {
1481 int flags = 0;
1482
1483 if (tun->flags & TUN_TUN_DEV)
1484 flags |= IFF_TUN;
1485 else
1486 flags |= IFF_TAP;
1487
1488 if (tun->flags & TUN_NO_PI)
1489 flags |= IFF_NO_PI;
1490
1491 /* This flag has no real effect. We track the value for backwards
1492 * compatibility.
1493 */
1494 if (tun->flags & TUN_ONE_QUEUE)
1495 flags |= IFF_ONE_QUEUE;
1496
1497 if (tun->flags & TUN_VNET_HDR)
1498 flags |= IFF_VNET_HDR;
1499
1500 if (tun->flags & TUN_TAP_MQ)
1501 flags |= IFF_MULTI_QUEUE;
1502
1503 return flags;
1504 }
1505
1506 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
1507 char *buf)
1508 {
1509 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1510 return sprintf(buf, "0x%x\n", tun_flags(tun));
1511 }
1512
1513 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
1514 char *buf)
1515 {
1516 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1517 return uid_valid(tun->owner)?
1518 sprintf(buf, "%u\n",
1519 from_kuid_munged(current_user_ns(), tun->owner)):
1520 sprintf(buf, "-1\n");
1521 }
1522
1523 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
1524 char *buf)
1525 {
1526 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1527 return gid_valid(tun->group) ?
1528 sprintf(buf, "%u\n",
1529 from_kgid_munged(current_user_ns(), tun->group)):
1530 sprintf(buf, "-1\n");
1531 }
1532
1533 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
1534 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
1535 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
1536
1537 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
1538 {
1539 struct tun_struct *tun;
1540 struct tun_file *tfile = file->private_data;
1541 struct net_device *dev;
1542 int err;
1543
1544 if (tfile->detached)
1545 return -EINVAL;
1546
1547 dev = __dev_get_by_name(net, ifr->ifr_name);
1548 if (dev) {
1549 if (ifr->ifr_flags & IFF_TUN_EXCL)
1550 return -EBUSY;
1551 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
1552 tun = netdev_priv(dev);
1553 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
1554 tun = netdev_priv(dev);
1555 else
1556 return -EINVAL;
1557
1558 if (tun_not_capable(tun))
1559 return -EPERM;
1560 err = security_tun_dev_attach(tfile->socket.sk);
1561 if (err < 0)
1562 return err;
1563
1564 err = tun_attach(tun, file);
1565 if (err < 0)
1566 return err;
1567
1568 if (tun->flags & TUN_TAP_MQ &&
1569 (tun->numqueues + tun->numdisabled > 1))
1570 return err;
1571 }
1572 else {
1573 char *name;
1574 unsigned long flags = 0;
1575
1576 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1577 return -EPERM;
1578 err = security_tun_dev_create();
1579 if (err < 0)
1580 return err;
1581
1582 /* Set dev type */
1583 if (ifr->ifr_flags & IFF_TUN) {
1584 /* TUN device */
1585 flags |= TUN_TUN_DEV;
1586 name = "tun%d";
1587 } else if (ifr->ifr_flags & IFF_TAP) {
1588 /* TAP device */
1589 flags |= TUN_TAP_DEV;
1590 name = "tap%d";
1591 } else
1592 return -EINVAL;
1593
1594 if (*ifr->ifr_name)
1595 name = ifr->ifr_name;
1596
1597 dev = alloc_netdev_mqs(sizeof(struct tun_struct), name,
1598 tun_setup,
1599 MAX_TAP_QUEUES, MAX_TAP_QUEUES);
1600 if (!dev)
1601 return -ENOMEM;
1602
1603 dev_net_set(dev, net);
1604 dev->rtnl_link_ops = &tun_link_ops;
1605
1606 tun = netdev_priv(dev);
1607 tun->dev = dev;
1608 tun->flags = flags;
1609 tun->txflt.count = 0;
1610 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
1611
1612 tun->filter_attached = false;
1613 tun->sndbuf = tfile->socket.sk->sk_sndbuf;
1614
1615 spin_lock_init(&tun->lock);
1616
1617 security_tun_dev_post_create(&tfile->sk);
1618
1619 tun_net_init(dev);
1620
1621 err = tun_flow_init(tun);
1622 if (err < 0)
1623 goto err_free_dev;
1624
1625 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
1626 TUN_USER_FEATURES;
1627 dev->features = dev->hw_features;
1628
1629 INIT_LIST_HEAD(&tun->disabled);
1630 err = tun_attach(tun, file);
1631 if (err < 0)
1632 goto err_free_dev;
1633
1634 err = register_netdevice(tun->dev);
1635 if (err < 0)
1636 goto err_free_dev;
1637
1638 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
1639 device_create_file(&tun->dev->dev, &dev_attr_owner) ||
1640 device_create_file(&tun->dev->dev, &dev_attr_group))
1641 pr_err("Failed to create tun sysfs files\n");
1642
1643 netif_carrier_on(tun->dev);
1644 }
1645
1646 tun_debug(KERN_INFO, tun, "tun_set_iff\n");
1647
1648 if (ifr->ifr_flags & IFF_NO_PI)
1649 tun->flags |= TUN_NO_PI;
1650 else
1651 tun->flags &= ~TUN_NO_PI;
1652
1653 /* This flag has no real effect. We track the value for backwards
1654 * compatibility.
1655 */
1656 if (ifr->ifr_flags & IFF_ONE_QUEUE)
1657 tun->flags |= TUN_ONE_QUEUE;
1658 else
1659 tun->flags &= ~TUN_ONE_QUEUE;
1660
1661 if (ifr->ifr_flags & IFF_VNET_HDR)
1662 tun->flags |= TUN_VNET_HDR;
1663 else
1664 tun->flags &= ~TUN_VNET_HDR;
1665
1666 if (ifr->ifr_flags & IFF_MULTI_QUEUE)
1667 tun->flags |= TUN_TAP_MQ;
1668 else
1669 tun->flags &= ~TUN_TAP_MQ;
1670
1671 /* Make sure persistent devices do not get stuck in
1672 * xoff state.
1673 */
1674 if (netif_running(tun->dev))
1675 netif_tx_wake_all_queues(tun->dev);
1676
1677 strcpy(ifr->ifr_name, tun->dev->name);
1678 return 0;
1679
1680 err_free_dev:
1681 free_netdev(dev);
1682 return err;
1683 }
1684
1685 static void tun_get_iff(struct net *net, struct tun_struct *tun,
1686 struct ifreq *ifr)
1687 {
1688 tun_debug(KERN_INFO, tun, "tun_get_iff\n");
1689
1690 strcpy(ifr->ifr_name, tun->dev->name);
1691
1692 ifr->ifr_flags = tun_flags(tun);
1693
1694 }
1695
1696 /* This is like a cut-down ethtool ops, except done via tun fd so no
1697 * privs required. */
1698 static int set_offload(struct tun_struct *tun, unsigned long arg)
1699 {
1700 netdev_features_t features = 0;
1701
1702 if (arg & TUN_F_CSUM) {
1703 features |= NETIF_F_HW_CSUM;
1704 arg &= ~TUN_F_CSUM;
1705
1706 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1707 if (arg & TUN_F_TSO_ECN) {
1708 features |= NETIF_F_TSO_ECN;
1709 arg &= ~TUN_F_TSO_ECN;
1710 }
1711 if (arg & TUN_F_TSO4)
1712 features |= NETIF_F_TSO;
1713 if (arg & TUN_F_TSO6)
1714 features |= NETIF_F_TSO6;
1715 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1716 }
1717
1718 if (arg & TUN_F_UFO) {
1719 features |= NETIF_F_UFO;
1720 arg &= ~TUN_F_UFO;
1721 }
1722 }
1723
1724 /* This gives the user a way to test for new features in future by
1725 * trying to set them. */
1726 if (arg)
1727 return -EINVAL;
1728
1729 tun->set_features = features;
1730 netdev_update_features(tun->dev);
1731
1732 return 0;
1733 }
1734
1735 static void tun_detach_filter(struct tun_struct *tun, int n)
1736 {
1737 int i;
1738 struct tun_file *tfile;
1739
1740 for (i = 0; i < n; i++) {
1741 tfile = rtnl_dereference(tun->tfiles[i]);
1742 sk_detach_filter(tfile->socket.sk);
1743 }
1744
1745 tun->filter_attached = false;
1746 }
1747
1748 static int tun_attach_filter(struct tun_struct *tun)
1749 {
1750 int i, ret = 0;
1751 struct tun_file *tfile;
1752
1753 for (i = 0; i < tun->numqueues; i++) {
1754 tfile = rtnl_dereference(tun->tfiles[i]);
1755 ret = sk_attach_filter(&tun->fprog, tfile->socket.sk);
1756 if (ret) {
1757 tun_detach_filter(tun, i);
1758 return ret;
1759 }
1760 }
1761
1762 tun->filter_attached = true;
1763 return ret;
1764 }
1765
1766 static void tun_set_sndbuf(struct tun_struct *tun)
1767 {
1768 struct tun_file *tfile;
1769 int i;
1770
1771 for (i = 0; i < tun->numqueues; i++) {
1772 tfile = rtnl_dereference(tun->tfiles[i]);
1773 tfile->socket.sk->sk_sndbuf = tun->sndbuf;
1774 }
1775 }
1776
1777 static int tun_set_queue(struct file *file, struct ifreq *ifr)
1778 {
1779 struct tun_file *tfile = file->private_data;
1780 struct tun_struct *tun;
1781 int ret = 0;
1782
1783 rtnl_lock();
1784
1785 if (ifr->ifr_flags & IFF_ATTACH_QUEUE) {
1786 tun = tfile->detached;
1787 if (!tun)
1788 ret = -EINVAL;
1789 else
1790 ret = tun_attach(tun, file);
1791 } else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
1792 tun = rtnl_dereference(tfile->tun);
1793 if (!tun || !(tun->flags & TUN_TAP_MQ))
1794 ret = -EINVAL;
1795 else
1796 __tun_detach(tfile, false);
1797 } else
1798 ret = -EINVAL;
1799
1800 rtnl_unlock();
1801 return ret;
1802 }
1803
1804 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
1805 unsigned long arg, int ifreq_len)
1806 {
1807 struct tun_file *tfile = file->private_data;
1808 struct tun_struct *tun;
1809 void __user* argp = (void __user*)arg;
1810 struct ifreq ifr;
1811 kuid_t owner;
1812 kgid_t group;
1813 int sndbuf;
1814 int vnet_hdr_sz;
1815 int ret;
1816
1817 if (cmd == TUNSETIFF || cmd == TUNSETQUEUE || _IOC_TYPE(cmd) == 0x89) {
1818 if (copy_from_user(&ifr, argp, ifreq_len))
1819 return -EFAULT;
1820 } else {
1821 memset(&ifr, 0, sizeof(ifr));
1822 }
1823 if (cmd == TUNGETFEATURES) {
1824 /* Currently this just means: "what IFF flags are valid?".
1825 * This is needed because we never checked for invalid flags on
1826 * TUNSETIFF. */
1827 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
1828 IFF_VNET_HDR | IFF_MULTI_QUEUE,
1829 (unsigned int __user*)argp);
1830 } else if (cmd == TUNSETQUEUE)
1831 return tun_set_queue(file, &ifr);
1832
1833 ret = 0;
1834 rtnl_lock();
1835
1836 tun = __tun_get(tfile);
1837 if (cmd == TUNSETIFF && !tun) {
1838 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1839
1840 ret = tun_set_iff(tfile->net, file, &ifr);
1841
1842 if (ret)
1843 goto unlock;
1844
1845 if (copy_to_user(argp, &ifr, ifreq_len))
1846 ret = -EFAULT;
1847 goto unlock;
1848 }
1849
1850 ret = -EBADFD;
1851 if (!tun)
1852 goto unlock;
1853
1854 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %u\n", cmd);
1855
1856 ret = 0;
1857 switch (cmd) {
1858 case TUNGETIFF:
1859 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1860
1861 if (copy_to_user(argp, &ifr, ifreq_len))
1862 ret = -EFAULT;
1863 break;
1864
1865 case TUNSETNOCSUM:
1866 /* Disable/Enable checksum */
1867
1868 /* [unimplemented] */
1869 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n",
1870 arg ? "disabled" : "enabled");
1871 break;
1872
1873 case TUNSETPERSIST:
1874 /* Disable/Enable persist mode. Keep an extra reference to the
1875 * module to prevent the module being unprobed.
1876 */
1877 if (arg) {
1878 tun->flags |= TUN_PERSIST;
1879 __module_get(THIS_MODULE);
1880 } else {
1881 tun->flags &= ~TUN_PERSIST;
1882 module_put(THIS_MODULE);
1883 }
1884
1885 tun_debug(KERN_INFO, tun, "persist %s\n",
1886 arg ? "enabled" : "disabled");
1887 break;
1888
1889 case TUNSETOWNER:
1890 /* Set owner of the device */
1891 owner = make_kuid(current_user_ns(), arg);
1892 if (!uid_valid(owner)) {
1893 ret = -EINVAL;
1894 break;
1895 }
1896 tun->owner = owner;
1897 tun_debug(KERN_INFO, tun, "owner set to %u\n",
1898 from_kuid(&init_user_ns, tun->owner));
1899 break;
1900
1901 case TUNSETGROUP:
1902 /* Set group of the device */
1903 group = make_kgid(current_user_ns(), arg);
1904 if (!gid_valid(group)) {
1905 ret = -EINVAL;
1906 break;
1907 }
1908 tun->group = group;
1909 tun_debug(KERN_INFO, tun, "group set to %u\n",
1910 from_kgid(&init_user_ns, tun->group));
1911 break;
1912
1913 case TUNSETLINK:
1914 /* Only allow setting the type when the interface is down */
1915 if (tun->dev->flags & IFF_UP) {
1916 tun_debug(KERN_INFO, tun,
1917 "Linktype set failed because interface is up\n");
1918 ret = -EBUSY;
1919 } else {
1920 tun->dev->type = (int) arg;
1921 tun_debug(KERN_INFO, tun, "linktype set to %d\n",
1922 tun->dev->type);
1923 ret = 0;
1924 }
1925 break;
1926
1927 #ifdef TUN_DEBUG
1928 case TUNSETDEBUG:
1929 tun->debug = arg;
1930 break;
1931 #endif
1932 case TUNSETOFFLOAD:
1933 ret = set_offload(tun, arg);
1934 break;
1935
1936 case TUNSETTXFILTER:
1937 /* Can be set only for TAPs */
1938 ret = -EINVAL;
1939 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1940 break;
1941 ret = update_filter(&tun->txflt, (void __user *)arg);
1942 break;
1943
1944 case SIOCGIFHWADDR:
1945 /* Get hw address */
1946 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
1947 ifr.ifr_hwaddr.sa_family = tun->dev->type;
1948 if (copy_to_user(argp, &ifr, ifreq_len))
1949 ret = -EFAULT;
1950 break;
1951
1952 case SIOCSIFHWADDR:
1953 /* Set hw address */
1954 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
1955 ifr.ifr_hwaddr.sa_data);
1956
1957 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
1958 break;
1959
1960 case TUNGETSNDBUF:
1961 sndbuf = tfile->socket.sk->sk_sndbuf;
1962 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
1963 ret = -EFAULT;
1964 break;
1965
1966 case TUNSETSNDBUF:
1967 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
1968 ret = -EFAULT;
1969 break;
1970 }
1971
1972 tun->sndbuf = sndbuf;
1973 tun_set_sndbuf(tun);
1974 break;
1975
1976 case TUNGETVNETHDRSZ:
1977 vnet_hdr_sz = tun->vnet_hdr_sz;
1978 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
1979 ret = -EFAULT;
1980 break;
1981
1982 case TUNSETVNETHDRSZ:
1983 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
1984 ret = -EFAULT;
1985 break;
1986 }
1987 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
1988 ret = -EINVAL;
1989 break;
1990 }
1991
1992 tun->vnet_hdr_sz = vnet_hdr_sz;
1993 break;
1994
1995 case TUNATTACHFILTER:
1996 /* Can be set only for TAPs */
1997 ret = -EINVAL;
1998 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1999 break;
2000 ret = -EFAULT;
2001 if (copy_from_user(&tun->fprog, argp, sizeof(tun->fprog)))
2002 break;
2003
2004 ret = tun_attach_filter(tun);
2005 break;
2006
2007 case TUNDETACHFILTER:
2008 /* Can be set only for TAPs */
2009 ret = -EINVAL;
2010 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
2011 break;
2012 ret = 0;
2013 tun_detach_filter(tun, tun->numqueues);
2014 break;
2015
2016 default:
2017 ret = -EINVAL;
2018 break;
2019 }
2020
2021 unlock:
2022 rtnl_unlock();
2023 if (tun)
2024 tun_put(tun);
2025 return ret;
2026 }
2027
2028 static long tun_chr_ioctl(struct file *file,
2029 unsigned int cmd, unsigned long arg)
2030 {
2031 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
2032 }
2033
2034 #ifdef CONFIG_COMPAT
2035 static long tun_chr_compat_ioctl(struct file *file,
2036 unsigned int cmd, unsigned long arg)
2037 {
2038 switch (cmd) {
2039 case TUNSETIFF:
2040 case TUNGETIFF:
2041 case TUNSETTXFILTER:
2042 case TUNGETSNDBUF:
2043 case TUNSETSNDBUF:
2044 case SIOCGIFHWADDR:
2045 case SIOCSIFHWADDR:
2046 arg = (unsigned long)compat_ptr(arg);
2047 break;
2048 default:
2049 arg = (compat_ulong_t)arg;
2050 break;
2051 }
2052
2053 /*
2054 * compat_ifreq is shorter than ifreq, so we must not access beyond
2055 * the end of that structure. All fields that are used in this
2056 * driver are compatible though, we don't need to convert the
2057 * contents.
2058 */
2059 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
2060 }
2061 #endif /* CONFIG_COMPAT */
2062
2063 static int tun_chr_fasync(int fd, struct file *file, int on)
2064 {
2065 struct tun_file *tfile = file->private_data;
2066 int ret;
2067
2068 if ((ret = fasync_helper(fd, file, on, &tfile->fasync)) < 0)
2069 goto out;
2070
2071 if (on) {
2072 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
2073 if (ret)
2074 goto out;
2075 tfile->flags |= TUN_FASYNC;
2076 } else
2077 tfile->flags &= ~TUN_FASYNC;
2078 ret = 0;
2079 out:
2080 return ret;
2081 }
2082
2083 static int tun_chr_open(struct inode *inode, struct file * file)
2084 {
2085 struct tun_file *tfile;
2086
2087 DBG1(KERN_INFO, "tunX: tun_chr_open\n");
2088
2089 tfile = (struct tun_file *)sk_alloc(&init_net, AF_UNSPEC, GFP_KERNEL,
2090 &tun_proto);
2091 if (!tfile)
2092 return -ENOMEM;
2093 rcu_assign_pointer(tfile->tun, NULL);
2094 tfile->net = get_net(current->nsproxy->net_ns);
2095 tfile->flags = 0;
2096
2097 rcu_assign_pointer(tfile->socket.wq, &tfile->wq);
2098 init_waitqueue_head(&tfile->wq.wait);
2099
2100 tfile->socket.file = file;
2101 tfile->socket.ops = &tun_socket_ops;
2102
2103 sock_init_data(&tfile->socket, &tfile->sk);
2104 sk_change_net(&tfile->sk, tfile->net);
2105
2106 tfile->sk.sk_write_space = tun_sock_write_space;
2107 tfile->sk.sk_sndbuf = INT_MAX;
2108
2109 file->private_data = tfile;
2110 set_bit(SOCK_EXTERNALLY_ALLOCATED, &tfile->socket.flags);
2111 INIT_LIST_HEAD(&tfile->next);
2112
2113 return 0;
2114 }
2115
2116 static int tun_chr_close(struct inode *inode, struct file *file)
2117 {
2118 struct tun_file *tfile = file->private_data;
2119 struct net *net = tfile->net;
2120
2121 tun_detach(tfile, true);
2122 put_net(net);
2123
2124 return 0;
2125 }
2126
2127 static const struct file_operations tun_fops = {
2128 .owner = THIS_MODULE,
2129 .llseek = no_llseek,
2130 .read = do_sync_read,
2131 .aio_read = tun_chr_aio_read,
2132 .write = do_sync_write,
2133 .aio_write = tun_chr_aio_write,
2134 .poll = tun_chr_poll,
2135 .unlocked_ioctl = tun_chr_ioctl,
2136 #ifdef CONFIG_COMPAT
2137 .compat_ioctl = tun_chr_compat_ioctl,
2138 #endif
2139 .open = tun_chr_open,
2140 .release = tun_chr_close,
2141 .fasync = tun_chr_fasync
2142 };
2143
2144 static struct miscdevice tun_miscdev = {
2145 .minor = TUN_MINOR,
2146 .name = "tun",
2147 .nodename = "net/tun",
2148 .fops = &tun_fops,
2149 };
2150
2151 /* ethtool interface */
2152
2153 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
2154 {
2155 cmd->supported = 0;
2156 cmd->advertising = 0;
2157 ethtool_cmd_speed_set(cmd, SPEED_10);
2158 cmd->duplex = DUPLEX_FULL;
2159 cmd->port = PORT_TP;
2160 cmd->phy_address = 0;
2161 cmd->transceiver = XCVR_INTERNAL;
2162 cmd->autoneg = AUTONEG_DISABLE;
2163 cmd->maxtxpkt = 0;
2164 cmd->maxrxpkt = 0;
2165 return 0;
2166 }
2167
2168 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
2169 {
2170 struct tun_struct *tun = netdev_priv(dev);
2171
2172 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
2173 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
2174
2175 switch (tun->flags & TUN_TYPE_MASK) {
2176 case TUN_TUN_DEV:
2177 strlcpy(info->bus_info, "tun", sizeof(info->bus_info));
2178 break;
2179 case TUN_TAP_DEV:
2180 strlcpy(info->bus_info, "tap", sizeof(info->bus_info));
2181 break;
2182 }
2183 }
2184
2185 static u32 tun_get_msglevel(struct net_device *dev)
2186 {
2187 #ifdef TUN_DEBUG
2188 struct tun_struct *tun = netdev_priv(dev);
2189 return tun->debug;
2190 #else
2191 return -EOPNOTSUPP;
2192 #endif
2193 }
2194
2195 static void tun_set_msglevel(struct net_device *dev, u32 value)
2196 {
2197 #ifdef TUN_DEBUG
2198 struct tun_struct *tun = netdev_priv(dev);
2199 tun->debug = value;
2200 #endif
2201 }
2202
2203 static const struct ethtool_ops tun_ethtool_ops = {
2204 .get_settings = tun_get_settings,
2205 .get_drvinfo = tun_get_drvinfo,
2206 .get_msglevel = tun_get_msglevel,
2207 .set_msglevel = tun_set_msglevel,
2208 .get_link = ethtool_op_get_link,
2209 };
2210
2211
2212 static int __init tun_init(void)
2213 {
2214 int ret = 0;
2215
2216 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
2217 pr_info("%s\n", DRV_COPYRIGHT);
2218
2219 ret = rtnl_link_register(&tun_link_ops);
2220 if (ret) {
2221 pr_err("Can't register link_ops\n");
2222 goto err_linkops;
2223 }
2224
2225 ret = misc_register(&tun_miscdev);
2226 if (ret) {
2227 pr_err("Can't register misc device %d\n", TUN_MINOR);
2228 goto err_misc;
2229 }
2230 return 0;
2231 err_misc:
2232 rtnl_link_unregister(&tun_link_ops);
2233 err_linkops:
2234 return ret;
2235 }
2236
2237 static void tun_cleanup(void)
2238 {
2239 misc_deregister(&tun_miscdev);
2240 rtnl_link_unregister(&tun_link_ops);
2241 }
2242
2243 /* Get an underlying socket object from tun file. Returns error unless file is
2244 * attached to a device. The returned object works like a packet socket, it
2245 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
2246 * holding a reference to the file for as long as the socket is in use. */
2247 struct socket *tun_get_socket(struct file *file)
2248 {
2249 struct tun_file *tfile;
2250 if (file->f_op != &tun_fops)
2251 return ERR_PTR(-EINVAL);
2252 tfile = file->private_data;
2253 if (!tfile)
2254 return ERR_PTR(-EBADFD);
2255 return &tfile->socket;
2256 }
2257 EXPORT_SYMBOL_GPL(tun_get_socket);
2258
2259 module_init(tun_init);
2260 module_exit(tun_cleanup);
2261 MODULE_DESCRIPTION(DRV_DESCRIPTION);
2262 MODULE_AUTHOR(DRV_COPYRIGHT);
2263 MODULE_LICENSE("GPL");
2264 MODULE_ALIAS_MISCDEV(TUN_MINOR);
2265 MODULE_ALIAS("devname:net/tun");
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree