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MAINTAINERS: fix arch/arm/plat-omap/include/plat/omap_hwmod.h
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / net / tun.c
blobfbd106edbe59bdcae871e29d6fd70c993634cdea
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 = rcu_dereference_protected(tfile->tun,
408 lockdep_rtnl_is_held());
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 = rcu_dereference_protected(tun->tfiles[index],
418 lockdep_rtnl_is_held());
419 ntfile->queue_index = index;
420
421 --tun->numqueues;
422 if (clean)
423 sock_put(&tfile->sk);
424 else
425 tun_disable_queue(tun, tfile);
426
427 synchronize_net();
428 tun_flow_delete_by_queue(tun, tun->numqueues + 1);
429 /* Drop read queue */
430 skb_queue_purge(&tfile->sk.sk_receive_queue);
431 tun_set_real_num_queues(tun);
432 } else if (tfile->detached && clean)
433 tun = tun_enable_queue(tfile);
434
435 if (clean) {
436 if (tun && tun->numqueues == 0 && tun->numdisabled == 0 &&
437 !(tun->flags & TUN_PERSIST))
438 if (tun->dev->reg_state == NETREG_REGISTERED)
439 unregister_netdevice(tun->dev);
440
441 BUG_ON(!test_bit(SOCK_EXTERNALLY_ALLOCATED,
442 &tfile->socket.flags));
443 sk_release_kernel(&tfile->sk);
444 }
445 }
446
447 static void tun_detach(struct tun_file *tfile, bool clean)
448 {
449 rtnl_lock();
450 __tun_detach(tfile, clean);
451 rtnl_unlock();
452 }
453
454 static void tun_detach_all(struct net_device *dev)
455 {
456 struct tun_struct *tun = netdev_priv(dev);
457 struct tun_file *tfile, *tmp;
458 int i, n = tun->numqueues;
459
460 for (i = 0; i < n; i++) {
461 tfile = rcu_dereference_protected(tun->tfiles[i],
462 lockdep_rtnl_is_held());
463 BUG_ON(!tfile);
464 wake_up_all(&tfile->wq.wait);
465 rcu_assign_pointer(tfile->tun, NULL);
466 --tun->numqueues;
467 }
468 BUG_ON(tun->numqueues != 0);
469
470 synchronize_net();
471 for (i = 0; i < n; i++) {
472 tfile = rcu_dereference_protected(tun->tfiles[i],
473 lockdep_rtnl_is_held());
474 /* Drop read queue */
475 skb_queue_purge(&tfile->sk.sk_receive_queue);
476 sock_put(&tfile->sk);
477 }
478 list_for_each_entry_safe(tfile, tmp, &tun->disabled, next) {
479 tun_enable_queue(tfile);
480 skb_queue_purge(&tfile->sk.sk_receive_queue);
481 sock_put(&tfile->sk);
482 }
483 BUG_ON(tun->numdisabled != 0);
484 }
485
486 static int tun_attach(struct tun_struct *tun, struct file *file)
487 {
488 struct tun_file *tfile = file->private_data;
489 int err;
490
491 err = -EINVAL;
492 if (rcu_dereference_protected(tfile->tun, lockdep_rtnl_is_held()))
493 goto out;
494
495 err = -EBUSY;
496 if (!(tun->flags & TUN_TAP_MQ) && tun->numqueues == 1)
497 goto out;
498
499 err = -E2BIG;
500 if (!tfile->detached &&
501 tun->numqueues + tun->numdisabled == MAX_TAP_QUEUES)
502 goto out;
503
504 err = 0;
505
506 /* Re-attach the filter to presist device */
507 if (tun->filter_attached == true) {
508 err = sk_attach_filter(&tun->fprog, tfile->socket.sk);
509 if (!err)
510 goto out;
511 }
512 tfile->queue_index = tun->numqueues;
513 rcu_assign_pointer(tfile->tun, tun);
514 rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile);
515 tun->numqueues++;
516
517 if (tfile->detached)
518 tun_enable_queue(tfile);
519 else
520 sock_hold(&tfile->sk);
521
522 tun_set_real_num_queues(tun);
523
524 /* device is allowed to go away first, so no need to hold extra
525 * refcnt.
526 */
527
528 out:
529 return err;
530 }
531
532 static struct tun_struct *__tun_get(struct tun_file *tfile)
533 {
534 struct tun_struct *tun;
535
536 rcu_read_lock();
537 tun = rcu_dereference(tfile->tun);
538 if (tun)
539 dev_hold(tun->dev);
540 rcu_read_unlock();
541
542 return tun;
543 }
544
545 static struct tun_struct *tun_get(struct file *file)
546 {
547 return __tun_get(file->private_data);
548 }
549
550 static void tun_put(struct tun_struct *tun)
551 {
552 dev_put(tun->dev);
553 }
554
555 /* TAP filtering */
556 static void addr_hash_set(u32 *mask, const u8 *addr)
557 {
558 int n = ether_crc(ETH_ALEN, addr) >> 26;
559 mask[n >> 5] |= (1 << (n & 31));
560 }
561
562 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
563 {
564 int n = ether_crc(ETH_ALEN, addr) >> 26;
565 return mask[n >> 5] & (1 << (n & 31));
566 }
567
568 static int update_filter(struct tap_filter *filter, void __user *arg)
569 {
570 struct { u8 u[ETH_ALEN]; } *addr;
571 struct tun_filter uf;
572 int err, alen, n, nexact;
573
574 if (copy_from_user(&uf, arg, sizeof(uf)))
575 return -EFAULT;
576
577 if (!uf.count) {
578 /* Disabled */
579 filter->count = 0;
580 return 0;
581 }
582
583 alen = ETH_ALEN * uf.count;
584 addr = kmalloc(alen, GFP_KERNEL);
585 if (!addr)
586 return -ENOMEM;
587
588 if (copy_from_user(addr, arg + sizeof(uf), alen)) {
589 err = -EFAULT;
590 goto done;
591 }
592
593 /* The filter is updated without holding any locks. Which is
594 * perfectly safe. We disable it first and in the worst
595 * case we'll accept a few undesired packets. */
596 filter->count = 0;
597 wmb();
598
599 /* Use first set of addresses as an exact filter */
600 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
601 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
602
603 nexact = n;
604
605 /* Remaining multicast addresses are hashed,
606 * unicast will leave the filter disabled. */
607 memset(filter->mask, 0, sizeof(filter->mask));
608 for (; n < uf.count; n++) {
609 if (!is_multicast_ether_addr(addr[n].u)) {
610 err = 0; /* no filter */
611 goto done;
612 }
613 addr_hash_set(filter->mask, addr[n].u);
614 }
615
616 /* For ALLMULTI just set the mask to all ones.
617 * This overrides the mask populated above. */
618 if ((uf.flags & TUN_FLT_ALLMULTI))
619 memset(filter->mask, ~0, sizeof(filter->mask));
620
621 /* Now enable the filter */
622 wmb();
623 filter->count = nexact;
624
625 /* Return the number of exact filters */
626 err = nexact;
627
628 done:
629 kfree(addr);
630 return err;
631 }
632
633 /* Returns: 0 - drop, !=0 - accept */
634 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
635 {
636 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
637 * at this point. */
638 struct ethhdr *eh = (struct ethhdr *) skb->data;
639 int i;
640
641 /* Exact match */
642 for (i = 0; i < filter->count; i++)
643 if (ether_addr_equal(eh->h_dest, filter->addr[i]))
644 return 1;
645
646 /* Inexact match (multicast only) */
647 if (is_multicast_ether_addr(eh->h_dest))
648 return addr_hash_test(filter->mask, eh->h_dest);
649
650 return 0;
651 }
652
653 /*
654 * Checks whether the packet is accepted or not.
655 * Returns: 0 - drop, !=0 - accept
656 */
657 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
658 {
659 if (!filter->count)
660 return 1;
661
662 return run_filter(filter, skb);
663 }
664
665 /* Network device part of the driver */
666
667 static const struct ethtool_ops tun_ethtool_ops;
668
669 /* Net device detach from fd. */
670 static void tun_net_uninit(struct net_device *dev)
671 {
672 tun_detach_all(dev);
673 }
674
675 /* Net device open. */
676 static int tun_net_open(struct net_device *dev)
677 {
678 netif_tx_start_all_queues(dev);
679 return 0;
680 }
681
682 /* Net device close. */
683 static int tun_net_close(struct net_device *dev)
684 {
685 netif_tx_stop_all_queues(dev);
686 return 0;
687 }
688
689 /* Net device start xmit */
690 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
691 {
692 struct tun_struct *tun = netdev_priv(dev);
693 int txq = skb->queue_mapping;
694 struct tun_file *tfile;
695
696 rcu_read_lock();
697 tfile = rcu_dereference(tun->tfiles[txq]);
698
699 /* Drop packet if interface is not attached */
700 if (txq >= tun->numqueues)
701 goto drop;
702
703 tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len);
704
705 BUG_ON(!tfile);
706
707 /* Drop if the filter does not like it.
708 * This is a noop if the filter is disabled.
709 * Filter can be enabled only for the TAP devices. */
710 if (!check_filter(&tun->txflt, skb))
711 goto drop;
712
713 if (tfile->socket.sk->sk_filter &&
714 sk_filter(tfile->socket.sk, skb))
715 goto drop;
716
717 /* Limit the number of packets queued by dividing txq length with the
718 * number of queues.
719 */
720 if (skb_queue_len(&tfile->socket.sk->sk_receive_queue)
721 >= dev->tx_queue_len / tun->numqueues)
722 goto drop;
723
724 /* Orphan the skb - required as we might hang on to it
725 * for indefinite time. */
726 if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
727 goto drop;
728 skb_orphan(skb);
729
730 /* Enqueue packet */
731 skb_queue_tail(&tfile->socket.sk->sk_receive_queue, skb);
732
733 /* Notify and wake up reader process */
734 if (tfile->flags & TUN_FASYNC)
735 kill_fasync(&tfile->fasync, SIGIO, POLL_IN);
736 wake_up_interruptible_poll(&tfile->wq.wait, POLLIN |
737 POLLRDNORM | POLLRDBAND);
738
739 rcu_read_unlock();
740 return NETDEV_TX_OK;
741
742 drop:
743 dev->stats.tx_dropped++;
744 skb_tx_error(skb);
745 kfree_skb(skb);
746 rcu_read_unlock();
747 return NETDEV_TX_OK;
748 }
749
750 static void tun_net_mclist(struct net_device *dev)
751 {
752 /*
753 * This callback is supposed to deal with mc filter in
754 * _rx_ path and has nothing to do with the _tx_ path.
755 * In rx path we always accept everything userspace gives us.
756 */
757 }
758
759 #define MIN_MTU 68
760 #define MAX_MTU 65535
761
762 static int
763 tun_net_change_mtu(struct net_device *dev, int new_mtu)
764 {
765 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
766 return -EINVAL;
767 dev->mtu = new_mtu;
768 return 0;
769 }
770
771 static netdev_features_t tun_net_fix_features(struct net_device *dev,
772 netdev_features_t features)
773 {
774 struct tun_struct *tun = netdev_priv(dev);
775
776 return (features & tun->set_features) | (features & ~TUN_USER_FEATURES);
777 }
778 #ifdef CONFIG_NET_POLL_CONTROLLER
779 static void tun_poll_controller(struct net_device *dev)
780 {
781 /*
782 * Tun only receives frames when:
783 * 1) the char device endpoint gets data from user space
784 * 2) the tun socket gets a sendmsg call from user space
785 * Since both of those are syncronous operations, we are guaranteed
786 * never to have pending data when we poll for it
787 * so theres nothing to do here but return.
788 * We need this though so netpoll recognizes us as an interface that
789 * supports polling, which enables bridge devices in virt setups to
790 * still use netconsole
791 */
792 return;
793 }
794 #endif
795 static const struct net_device_ops tun_netdev_ops = {
796 .ndo_uninit = tun_net_uninit,
797 .ndo_open = tun_net_open,
798 .ndo_stop = tun_net_close,
799 .ndo_start_xmit = tun_net_xmit,
800 .ndo_change_mtu = tun_net_change_mtu,
801 .ndo_fix_features = tun_net_fix_features,
802 .ndo_select_queue = tun_select_queue,
803 #ifdef CONFIG_NET_POLL_CONTROLLER
804 .ndo_poll_controller = tun_poll_controller,
805 #endif
806 };
807
808 static const struct net_device_ops tap_netdev_ops = {
809 .ndo_uninit = tun_net_uninit,
810 .ndo_open = tun_net_open,
811 .ndo_stop = tun_net_close,
812 .ndo_start_xmit = tun_net_xmit,
813 .ndo_change_mtu = tun_net_change_mtu,
814 .ndo_fix_features = tun_net_fix_features,
815 .ndo_set_rx_mode = tun_net_mclist,
816 .ndo_set_mac_address = eth_mac_addr,
817 .ndo_validate_addr = eth_validate_addr,
818 .ndo_select_queue = tun_select_queue,
819 #ifdef CONFIG_NET_POLL_CONTROLLER
820 .ndo_poll_controller = tun_poll_controller,
821 #endif
822 };
823
824 static int tun_flow_init(struct tun_struct *tun)
825 {
826 int i;
827
828 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++)
829 INIT_HLIST_HEAD(&tun->flows[i]);
830
831 tun->ageing_time = TUN_FLOW_EXPIRE;
832 setup_timer(&tun->flow_gc_timer, tun_flow_cleanup, (unsigned long)tun);
833 mod_timer(&tun->flow_gc_timer,
834 round_jiffies_up(jiffies + tun->ageing_time));
835
836 return 0;
837 }
838
839 static void tun_flow_uninit(struct tun_struct *tun)
840 {
841 del_timer_sync(&tun->flow_gc_timer);
842 tun_flow_flush(tun);
843 }
844
845 /* Initialize net device. */
846 static void tun_net_init(struct net_device *dev)
847 {
848 struct tun_struct *tun = netdev_priv(dev);
849
850 switch (tun->flags & TUN_TYPE_MASK) {
851 case TUN_TUN_DEV:
852 dev->netdev_ops = &tun_netdev_ops;
853
854 /* Point-to-Point TUN Device */
855 dev->hard_header_len = 0;
856 dev->addr_len = 0;
857 dev->mtu = 1500;
858
859 /* Zero header length */
860 dev->type = ARPHRD_NONE;
861 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
862 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
863 break;
864
865 case TUN_TAP_DEV:
866 dev->netdev_ops = &tap_netdev_ops;
867 /* Ethernet TAP Device */
868 ether_setup(dev);
869 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
870 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
871
872 eth_hw_addr_random(dev);
873
874 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
875 break;
876 }
877 }
878
879 /* Character device part */
880
881 /* Poll */
882 static unsigned int tun_chr_poll(struct file *file, poll_table *wait)
883 {
884 struct tun_file *tfile = file->private_data;
885 struct tun_struct *tun = __tun_get(tfile);
886 struct sock *sk;
887 unsigned int mask = 0;
888
889 if (!tun)
890 return POLLERR;
891
892 sk = tfile->socket.sk;
893
894 tun_debug(KERN_INFO, tun, "tun_chr_poll\n");
895
896 poll_wait(file, &tfile->wq.wait, wait);
897
898 if (!skb_queue_empty(&sk->sk_receive_queue))
899 mask |= POLLIN | POLLRDNORM;
900
901 if (sock_writeable(sk) ||
902 (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
903 sock_writeable(sk)))
904 mask |= POLLOUT | POLLWRNORM;
905
906 if (tun->dev->reg_state != NETREG_REGISTERED)
907 mask = POLLERR;
908
909 tun_put(tun);
910 return mask;
911 }
912
913 /* prepad is the amount to reserve at front. len is length after that.
914 * linear is a hint as to how much to copy (usually headers). */
915 static struct sk_buff *tun_alloc_skb(struct tun_file *tfile,
916 size_t prepad, size_t len,
917 size_t linear, int noblock)
918 {
919 struct sock *sk = tfile->socket.sk;
920 struct sk_buff *skb;
921 int err;
922
923 /* Under a page? Don't bother with paged skb. */
924 if (prepad + len < PAGE_SIZE || !linear)
925 linear = len;
926
927 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
928 &err);
929 if (!skb)
930 return ERR_PTR(err);
931
932 skb_reserve(skb, prepad);
933 skb_put(skb, linear);
934 skb->data_len = len - linear;
935 skb->len += len - linear;
936
937 return skb;
938 }
939
940 /* set skb frags from iovec, this can move to core network code for reuse */
941 static int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *from,
942 int offset, size_t count)
943 {
944 int len = iov_length(from, count) - offset;
945 int copy = skb_headlen(skb);
946 int size, offset1 = 0;
947 int i = 0;
948
949 /* Skip over from offset */
950 while (count && (offset >= from->iov_len)) {
951 offset -= from->iov_len;
952 ++from;
953 --count;
954 }
955
956 /* copy up to skb headlen */
957 while (count && (copy > 0)) {
958 size = min_t(unsigned int, copy, from->iov_len - offset);
959 if (copy_from_user(skb->data + offset1, from->iov_base + offset,
960 size))
961 return -EFAULT;
962 if (copy > size) {
963 ++from;
964 --count;
965 offset = 0;
966 } else
967 offset += size;
968 copy -= size;
969 offset1 += size;
970 }
971
972 if (len == offset1)
973 return 0;
974
975 while (count--) {
976 struct page *page[MAX_SKB_FRAGS];
977 int num_pages;
978 unsigned long base;
979 unsigned long truesize;
980
981 len = from->iov_len - offset;
982 if (!len) {
983 offset = 0;
984 ++from;
985 continue;
986 }
987 base = (unsigned long)from->iov_base + offset;
988 size = ((base & ~PAGE_MASK) + len + ~PAGE_MASK) >> PAGE_SHIFT;
989 if (i + size > MAX_SKB_FRAGS)
990 return -EMSGSIZE;
991 num_pages = get_user_pages_fast(base, size, 0, &page[i]);
992 if (num_pages != size) {
993 for (i = 0; i < num_pages; i++)
994 put_page(page[i]);
995 return -EFAULT;
996 }
997 truesize = size * PAGE_SIZE;
998 skb->data_len += len;
999 skb->len += len;
1000 skb->truesize += truesize;
1001 atomic_add(truesize, &skb->sk->sk_wmem_alloc);
1002 while (len) {
1003 int off = base & ~PAGE_MASK;
1004 int size = min_t(int, len, PAGE_SIZE - off);
1005 __skb_fill_page_desc(skb, i, page[i], off, size);
1006 skb_shinfo(skb)->nr_frags++;
1007 /* increase sk_wmem_alloc */
1008 base += size;
1009 len -= size;
1010 i++;
1011 }
1012 offset = 0;
1013 ++from;
1014 }
1015 return 0;
1016 }
1017
1018 /* Get packet from user space buffer */
1019 static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
1020 void *msg_control, const struct iovec *iv,
1021 size_t total_len, size_t count, int noblock)
1022 {
1023 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
1024 struct sk_buff *skb;
1025 size_t len = total_len, align = NET_SKB_PAD;
1026 struct virtio_net_hdr gso = { 0 };
1027 int offset = 0;
1028 int copylen;
1029 bool zerocopy = false;
1030 int err;
1031 u32 rxhash;
1032
1033 if (!(tun->flags & TUN_NO_PI)) {
1034 if ((len -= sizeof(pi)) > total_len)
1035 return -EINVAL;
1036
1037 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
1038 return -EFAULT;
1039 offset += sizeof(pi);
1040 }
1041
1042 if (tun->flags & TUN_VNET_HDR) {
1043 if ((len -= tun->vnet_hdr_sz) > total_len)
1044 return -EINVAL;
1045
1046 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
1047 return -EFAULT;
1048
1049 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
1050 gso.csum_start + gso.csum_offset + 2 > gso.hdr_len)
1051 gso.hdr_len = gso.csum_start + gso.csum_offset + 2;
1052
1053 if (gso.hdr_len > len)
1054 return -EINVAL;
1055 offset += tun->vnet_hdr_sz;
1056 }
1057
1058 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
1059 align += NET_IP_ALIGN;
1060 if (unlikely(len < ETH_HLEN ||
1061 (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
1062 return -EINVAL;
1063 }
1064
1065 if (msg_control)
1066 zerocopy = true;
1067
1068 if (zerocopy) {
1069 /* Userspace may produce vectors with count greater than
1070 * MAX_SKB_FRAGS, so we need to linearize parts of the skb
1071 * to let the rest of data to be fit in the frags.
1072 */
1073 if (count > MAX_SKB_FRAGS) {
1074 copylen = iov_length(iv, count - MAX_SKB_FRAGS);
1075 if (copylen < offset)
1076 copylen = 0;
1077 else
1078 copylen -= offset;
1079 } else
1080 copylen = 0;
1081 /* There are 256 bytes to be copied in skb, so there is enough
1082 * room for skb expand head in case it is used.
1083 * The rest of the buffer is mapped from userspace.
1084 */
1085 if (copylen < gso.hdr_len)
1086 copylen = gso.hdr_len;
1087 if (!copylen)
1088 copylen = GOODCOPY_LEN;
1089 } else
1090 copylen = len;
1091
1092 skb = tun_alloc_skb(tfile, align, copylen, gso.hdr_len, noblock);
1093 if (IS_ERR(skb)) {
1094 if (PTR_ERR(skb) != -EAGAIN)
1095 tun->dev->stats.rx_dropped++;
1096 return PTR_ERR(skb);
1097 }
1098
1099 if (zerocopy)
1100 err = zerocopy_sg_from_iovec(skb, iv, offset, count);
1101 else
1102 err = skb_copy_datagram_from_iovec(skb, 0, iv, offset, len);
1103
1104 if (err) {
1105 tun->dev->stats.rx_dropped++;
1106 kfree_skb(skb);
1107 return -EFAULT;
1108 }
1109
1110 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
1111 if (!skb_partial_csum_set(skb, gso.csum_start,
1112 gso.csum_offset)) {
1113 tun->dev->stats.rx_frame_errors++;
1114 kfree_skb(skb);
1115 return -EINVAL;
1116 }
1117 }
1118
1119 switch (tun->flags & TUN_TYPE_MASK) {
1120 case TUN_TUN_DEV:
1121 if (tun->flags & TUN_NO_PI) {
1122 switch (skb->data[0] & 0xf0) {
1123 case 0x40:
1124 pi.proto = htons(ETH_P_IP);
1125 break;
1126 case 0x60:
1127 pi.proto = htons(ETH_P_IPV6);
1128 break;
1129 default:
1130 tun->dev->stats.rx_dropped++;
1131 kfree_skb(skb);
1132 return -EINVAL;
1133 }
1134 }
1135
1136 skb_reset_mac_header(skb);
1137 skb->protocol = pi.proto;
1138 skb->dev = tun->dev;
1139 break;
1140 case TUN_TAP_DEV:
1141 skb->protocol = eth_type_trans(skb, tun->dev);
1142 break;
1143 }
1144
1145 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
1146 pr_debug("GSO!\n");
1147 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
1148 case VIRTIO_NET_HDR_GSO_TCPV4:
1149 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
1150 break;
1151 case VIRTIO_NET_HDR_GSO_TCPV6:
1152 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
1153 break;
1154 case VIRTIO_NET_HDR_GSO_UDP:
1155 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
1156 break;
1157 default:
1158 tun->dev->stats.rx_frame_errors++;
1159 kfree_skb(skb);
1160 return -EINVAL;
1161 }
1162
1163 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
1164 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
1165
1166 skb_shinfo(skb)->gso_size = gso.gso_size;
1167 if (skb_shinfo(skb)->gso_size == 0) {
1168 tun->dev->stats.rx_frame_errors++;
1169 kfree_skb(skb);
1170 return -EINVAL;
1171 }
1172
1173 /* Header must be checked, and gso_segs computed. */
1174 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
1175 skb_shinfo(skb)->gso_segs = 0;
1176 }
1177
1178 /* copy skb_ubuf_info for callback when skb has no error */
1179 if (zerocopy) {
1180 skb_shinfo(skb)->destructor_arg = msg_control;
1181 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1182 }
1183
1184 skb_reset_network_header(skb);
1185 rxhash = skb_get_rxhash(skb);
1186 netif_rx_ni(skb);
1187
1188 tun->dev->stats.rx_packets++;
1189 tun->dev->stats.rx_bytes += len;
1190
1191 tun_flow_update(tun, rxhash, tfile->queue_index);
1192 return total_len;
1193 }
1194
1195 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
1196 unsigned long count, loff_t pos)
1197 {
1198 struct file *file = iocb->ki_filp;
1199 struct tun_struct *tun = tun_get(file);
1200 struct tun_file *tfile = file->private_data;
1201 ssize_t result;
1202
1203 if (!tun)
1204 return -EBADFD;
1205
1206 tun_debug(KERN_INFO, tun, "tun_chr_write %ld\n", count);
1207
1208 result = tun_get_user(tun, tfile, NULL, iv, iov_length(iv, count),
1209 count, file->f_flags & O_NONBLOCK);
1210
1211 tun_put(tun);
1212 return result;
1213 }
1214
1215 /* Put packet to the user space buffer */
1216 static ssize_t tun_put_user(struct tun_struct *tun,
1217 struct tun_file *tfile,
1218 struct sk_buff *skb,
1219 const struct iovec *iv, int len)
1220 {
1221 struct tun_pi pi = { 0, skb->protocol };
1222 ssize_t total = 0;
1223
1224 if (!(tun->flags & TUN_NO_PI)) {
1225 if ((len -= sizeof(pi)) < 0)
1226 return -EINVAL;
1227
1228 if (len < skb->len) {
1229 /* Packet will be striped */
1230 pi.flags |= TUN_PKT_STRIP;
1231 }
1232
1233 if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi)))
1234 return -EFAULT;
1235 total += sizeof(pi);
1236 }
1237
1238 if (tun->flags & TUN_VNET_HDR) {
1239 struct virtio_net_hdr gso = { 0 }; /* no info leak */
1240 if ((len -= tun->vnet_hdr_sz) < 0)
1241 return -EINVAL;
1242
1243 if (skb_is_gso(skb)) {
1244 struct skb_shared_info *sinfo = skb_shinfo(skb);
1245
1246 /* This is a hint as to how much should be linear. */
1247 gso.hdr_len = skb_headlen(skb);
1248 gso.gso_size = sinfo->gso_size;
1249 if (sinfo->gso_type & SKB_GSO_TCPV4)
1250 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
1251 else if (sinfo->gso_type & SKB_GSO_TCPV6)
1252 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
1253 else if (sinfo->gso_type & SKB_GSO_UDP)
1254 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
1255 else {
1256 pr_err("unexpected GSO type: "
1257 "0x%x, gso_size %d, hdr_len %d\n",
1258 sinfo->gso_type, gso.gso_size,
1259 gso.hdr_len);
1260 print_hex_dump(KERN_ERR, "tun: ",
1261 DUMP_PREFIX_NONE,
1262 16, 1, skb->head,
1263 min((int)gso.hdr_len, 64), true);
1264 WARN_ON_ONCE(1);
1265 return -EINVAL;
1266 }
1267 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
1268 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
1269 } else
1270 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
1271
1272 if (skb->ip_summed == CHECKSUM_PARTIAL) {
1273 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
1274 gso.csum_start = skb_checksum_start_offset(skb);
1275 gso.csum_offset = skb->csum_offset;
1276 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
1277 gso.flags = VIRTIO_NET_HDR_F_DATA_VALID;
1278 } /* else everything is zero */
1279
1280 if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
1281 sizeof(gso))))
1282 return -EFAULT;
1283 total += tun->vnet_hdr_sz;
1284 }
1285
1286 len = min_t(int, skb->len, len);
1287
1288 skb_copy_datagram_const_iovec(skb, 0, iv, total, len);
1289 total += skb->len;
1290
1291 tun->dev->stats.tx_packets++;
1292 tun->dev->stats.tx_bytes += len;
1293
1294 return total;
1295 }
1296
1297 static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
1298 struct kiocb *iocb, const struct iovec *iv,
1299 ssize_t len, int noblock)
1300 {
1301 DECLARE_WAITQUEUE(wait, current);
1302 struct sk_buff *skb;
1303 ssize_t ret = 0;
1304
1305 tun_debug(KERN_INFO, tun, "tun_do_read\n");
1306
1307 if (unlikely(!noblock))
1308 add_wait_queue(&tfile->wq.wait, &wait);
1309 while (len) {
1310 current->state = TASK_INTERRUPTIBLE;
1311
1312 /* Read frames from the queue */
1313 if (!(skb = skb_dequeue(&tfile->socket.sk->sk_receive_queue))) {
1314 if (noblock) {
1315 ret = -EAGAIN;
1316 break;
1317 }
1318 if (signal_pending(current)) {
1319 ret = -ERESTARTSYS;
1320 break;
1321 }
1322 if (tun->dev->reg_state != NETREG_REGISTERED) {
1323 ret = -EIO;
1324 break;
1325 }
1326
1327 /* Nothing to read, let's sleep */
1328 schedule();
1329 continue;
1330 }
1331
1332 ret = tun_put_user(tun, tfile, skb, iv, len);
1333 kfree_skb(skb);
1334 break;
1335 }
1336
1337 current->state = TASK_RUNNING;
1338 if (unlikely(!noblock))
1339 remove_wait_queue(&tfile->wq.wait, &wait);
1340
1341 return ret;
1342 }
1343
1344 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
1345 unsigned long count, loff_t pos)
1346 {
1347 struct file *file = iocb->ki_filp;
1348 struct tun_file *tfile = file->private_data;
1349 struct tun_struct *tun = __tun_get(tfile);
1350 ssize_t len, ret;
1351
1352 if (!tun)
1353 return -EBADFD;
1354 len = iov_length(iv, count);
1355 if (len < 0) {
1356 ret = -EINVAL;
1357 goto out;
1358 }
1359
1360 ret = tun_do_read(tun, tfile, iocb, iv, len,
1361 file->f_flags & O_NONBLOCK);
1362 ret = min_t(ssize_t, ret, len);
1363 out:
1364 tun_put(tun);
1365 return ret;
1366 }
1367
1368 static void tun_free_netdev(struct net_device *dev)
1369 {
1370 struct tun_struct *tun = netdev_priv(dev);
1371
1372 BUG_ON(!(list_empty(&tun->disabled)));
1373 tun_flow_uninit(tun);
1374 free_netdev(dev);
1375 }
1376
1377 static void tun_setup(struct net_device *dev)
1378 {
1379 struct tun_struct *tun = netdev_priv(dev);
1380
1381 tun->owner = INVALID_UID;
1382 tun->group = INVALID_GID;
1383
1384 dev->ethtool_ops = &tun_ethtool_ops;
1385 dev->destructor = tun_free_netdev;
1386 }
1387
1388 /* Trivial set of netlink ops to allow deleting tun or tap
1389 * device with netlink.
1390 */
1391 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
1392 {
1393 return -EINVAL;
1394 }
1395
1396 static struct rtnl_link_ops tun_link_ops __read_mostly = {
1397 .kind = DRV_NAME,
1398 .priv_size = sizeof(struct tun_struct),
1399 .setup = tun_setup,
1400 .validate = tun_validate,
1401 };
1402
1403 static void tun_sock_write_space(struct sock *sk)
1404 {
1405 struct tun_file *tfile;
1406 wait_queue_head_t *wqueue;
1407
1408 if (!sock_writeable(sk))
1409 return;
1410
1411 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
1412 return;
1413
1414 wqueue = sk_sleep(sk);
1415 if (wqueue && waitqueue_active(wqueue))
1416 wake_up_interruptible_sync_poll(wqueue, POLLOUT |
1417 POLLWRNORM | POLLWRBAND);
1418
1419 tfile = container_of(sk, struct tun_file, sk);
1420 kill_fasync(&tfile->fasync, SIGIO, POLL_OUT);
1421 }
1422
1423 static int tun_sendmsg(struct kiocb *iocb, struct socket *sock,
1424 struct msghdr *m, size_t total_len)
1425 {
1426 int ret;
1427 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1428 struct tun_struct *tun = __tun_get(tfile);
1429
1430 if (!tun)
1431 return -EBADFD;
1432 ret = tun_get_user(tun, tfile, m->msg_control, m->msg_iov, total_len,
1433 m->msg_iovlen, m->msg_flags & MSG_DONTWAIT);
1434 tun_put(tun);
1435 return ret;
1436 }
1437
1438
1439 static int tun_recvmsg(struct kiocb *iocb, struct socket *sock,
1440 struct msghdr *m, size_t total_len,
1441 int flags)
1442 {
1443 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1444 struct tun_struct *tun = __tun_get(tfile);
1445 int ret;
1446
1447 if (!tun)
1448 return -EBADFD;
1449
1450 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))
1451 return -EINVAL;
1452 ret = tun_do_read(tun, tfile, iocb, m->msg_iov, total_len,
1453 flags & MSG_DONTWAIT);
1454 if (ret > total_len) {
1455 m->msg_flags |= MSG_TRUNC;
1456 ret = flags & MSG_TRUNC ? ret : total_len;
1457 }
1458 tun_put(tun);
1459 return ret;
1460 }
1461
1462 static int tun_release(struct socket *sock)
1463 {
1464 if (sock->sk)
1465 sock_put(sock->sk);
1466 return 0;
1467 }
1468
1469 /* Ops structure to mimic raw sockets with tun */
1470 static const struct proto_ops tun_socket_ops = {
1471 .sendmsg = tun_sendmsg,
1472 .recvmsg = tun_recvmsg,
1473 .release = tun_release,
1474 };
1475
1476 static struct proto tun_proto = {
1477 .name = "tun",
1478 .owner = THIS_MODULE,
1479 .obj_size = sizeof(struct tun_file),
1480 };
1481
1482 static int tun_flags(struct tun_struct *tun)
1483 {
1484 int flags = 0;
1485
1486 if (tun->flags & TUN_TUN_DEV)
1487 flags |= IFF_TUN;
1488 else
1489 flags |= IFF_TAP;
1490
1491 if (tun->flags & TUN_NO_PI)
1492 flags |= IFF_NO_PI;
1493
1494 /* This flag has no real effect. We track the value for backwards
1495 * compatibility.
1496 */
1497 if (tun->flags & TUN_ONE_QUEUE)
1498 flags |= IFF_ONE_QUEUE;
1499
1500 if (tun->flags & TUN_VNET_HDR)
1501 flags |= IFF_VNET_HDR;
1502
1503 if (tun->flags & TUN_TAP_MQ)
1504 flags |= IFF_MULTI_QUEUE;
1505
1506 return flags;
1507 }
1508
1509 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
1510 char *buf)
1511 {
1512 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1513 return sprintf(buf, "0x%x\n", tun_flags(tun));
1514 }
1515
1516 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
1517 char *buf)
1518 {
1519 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1520 return uid_valid(tun->owner)?
1521 sprintf(buf, "%u\n",
1522 from_kuid_munged(current_user_ns(), tun->owner)):
1523 sprintf(buf, "-1\n");
1524 }
1525
1526 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
1527 char *buf)
1528 {
1529 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1530 return gid_valid(tun->group) ?
1531 sprintf(buf, "%u\n",
1532 from_kgid_munged(current_user_ns(), tun->group)):
1533 sprintf(buf, "-1\n");
1534 }
1535
1536 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
1537 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
1538 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
1539
1540 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
1541 {
1542 struct tun_struct *tun;
1543 struct tun_file *tfile = file->private_data;
1544 struct net_device *dev;
1545 int err;
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 = rcu_dereference_protected(tun->tfiles[i],
1742 lockdep_rtnl_is_held());
1743 sk_detach_filter(tfile->socket.sk);
1744 }
1745
1746 tun->filter_attached = false;
1747 }
1748
1749 static int tun_attach_filter(struct tun_struct *tun)
1750 {
1751 int i, ret = 0;
1752 struct tun_file *tfile;
1753
1754 for (i = 0; i < tun->numqueues; i++) {
1755 tfile = rcu_dereference_protected(tun->tfiles[i],
1756 lockdep_rtnl_is_held());
1757 ret = sk_attach_filter(&tun->fprog, tfile->socket.sk);
1758 if (ret) {
1759 tun_detach_filter(tun, i);
1760 return ret;
1761 }
1762 }
1763
1764 tun->filter_attached = true;
1765 return ret;
1766 }
1767
1768 static void tun_set_sndbuf(struct tun_struct *tun)
1769 {
1770 struct tun_file *tfile;
1771 int i;
1772
1773 for (i = 0; i < tun->numqueues; i++) {
1774 tfile = rcu_dereference_protected(tun->tfiles[i],
1775 lockdep_rtnl_is_held());
1776 tfile->socket.sk->sk_sndbuf = tun->sndbuf;
1777 }
1778 }
1779
1780 static int tun_set_queue(struct file *file, struct ifreq *ifr)
1781 {
1782 struct tun_file *tfile = file->private_data;
1783 struct tun_struct *tun;
1784 int ret = 0;
1785
1786 rtnl_lock();
1787
1788 if (ifr->ifr_flags & IFF_ATTACH_QUEUE) {
1789 tun = tfile->detached;
1790 if (!tun)
1791 ret = -EINVAL;
1792 else if (tun_not_capable(tun))
1793 ret = -EPERM;
1794 else
1795 ret = tun_attach(tun, file);
1796 } else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
1797 tun = rcu_dereference_protected(tfile->tun,
1798 lockdep_rtnl_is_held());
1799 if (!tun || !(tun->flags & TUN_TAP_MQ))
1800 ret = -EINVAL;
1801 else
1802 __tun_detach(tfile, false);
1803 } else
1804 ret = -EINVAL;
1805
1806 rtnl_unlock();
1807 return ret;
1808 }
1809
1810 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
1811 unsigned long arg, int ifreq_len)
1812 {
1813 struct tun_file *tfile = file->private_data;
1814 struct tun_struct *tun;
1815 void __user* argp = (void __user*)arg;
1816 struct ifreq ifr;
1817 kuid_t owner;
1818 kgid_t group;
1819 int sndbuf;
1820 int vnet_hdr_sz;
1821 int ret;
1822
1823 if (cmd == TUNSETIFF || cmd == TUNSETQUEUE || _IOC_TYPE(cmd) == 0x89) {
1824 if (copy_from_user(&ifr, argp, ifreq_len))
1825 return -EFAULT;
1826 } else {
1827 memset(&ifr, 0, sizeof(ifr));
1828 }
1829 if (cmd == TUNGETFEATURES) {
1830 /* Currently this just means: "what IFF flags are valid?".
1831 * This is needed because we never checked for invalid flags on
1832 * TUNSETIFF. */
1833 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
1834 IFF_VNET_HDR | IFF_MULTI_QUEUE,
1835 (unsigned int __user*)argp);
1836 } else if (cmd == TUNSETQUEUE)
1837 return tun_set_queue(file, &ifr);
1838
1839 ret = 0;
1840 rtnl_lock();
1841
1842 tun = __tun_get(tfile);
1843 if (cmd == TUNSETIFF && !tun) {
1844 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1845
1846 ret = tun_set_iff(tfile->net, file, &ifr);
1847
1848 if (ret)
1849 goto unlock;
1850
1851 if (copy_to_user(argp, &ifr, ifreq_len))
1852 ret = -EFAULT;
1853 goto unlock;
1854 }
1855
1856 ret = -EBADFD;
1857 if (!tun)
1858 goto unlock;
1859
1860 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %u\n", cmd);
1861
1862 ret = 0;
1863 switch (cmd) {
1864 case TUNGETIFF:
1865 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1866
1867 if (copy_to_user(argp, &ifr, ifreq_len))
1868 ret = -EFAULT;
1869 break;
1870
1871 case TUNSETNOCSUM:
1872 /* Disable/Enable checksum */
1873
1874 /* [unimplemented] */
1875 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n",
1876 arg ? "disabled" : "enabled");
1877 break;
1878
1879 case TUNSETPERSIST:
1880 /* Disable/Enable persist mode. Keep an extra reference to the
1881 * module to prevent the module being unprobed.
1882 */
1883 if (arg) {
1884 tun->flags |= TUN_PERSIST;
1885 __module_get(THIS_MODULE);
1886 } else {
1887 tun->flags &= ~TUN_PERSIST;
1888 module_put(THIS_MODULE);
1889 }
1890
1891 tun_debug(KERN_INFO, tun, "persist %s\n",
1892 arg ? "enabled" : "disabled");
1893 break;
1894
1895 case TUNSETOWNER:
1896 /* Set owner of the device */
1897 owner = make_kuid(current_user_ns(), arg);
1898 if (!uid_valid(owner)) {
1899 ret = -EINVAL;
1900 break;
1901 }
1902 tun->owner = owner;
1903 tun_debug(KERN_INFO, tun, "owner set to %u\n",
1904 from_kuid(&init_user_ns, tun->owner));
1905 break;
1906
1907 case TUNSETGROUP:
1908 /* Set group of the device */
1909 group = make_kgid(current_user_ns(), arg);
1910 if (!gid_valid(group)) {
1911 ret = -EINVAL;
1912 break;
1913 }
1914 tun->group = group;
1915 tun_debug(KERN_INFO, tun, "group set to %u\n",
1916 from_kgid(&init_user_ns, tun->group));
1917 break;
1918
1919 case TUNSETLINK:
1920 /* Only allow setting the type when the interface is down */
1921 if (tun->dev->flags & IFF_UP) {
1922 tun_debug(KERN_INFO, tun,
1923 "Linktype set failed because interface is up\n");
1924 ret = -EBUSY;
1925 } else {
1926 tun->dev->type = (int) arg;
1927 tun_debug(KERN_INFO, tun, "linktype set to %d\n",
1928 tun->dev->type);
1929 ret = 0;
1930 }
1931 break;
1932
1933 #ifdef TUN_DEBUG
1934 case TUNSETDEBUG:
1935 tun->debug = arg;
1936 break;
1937 #endif
1938 case TUNSETOFFLOAD:
1939 ret = set_offload(tun, arg);
1940 break;
1941
1942 case TUNSETTXFILTER:
1943 /* Can be set only for TAPs */
1944 ret = -EINVAL;
1945 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1946 break;
1947 ret = update_filter(&tun->txflt, (void __user *)arg);
1948 break;
1949
1950 case SIOCGIFHWADDR:
1951 /* Get hw address */
1952 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
1953 ifr.ifr_hwaddr.sa_family = tun->dev->type;
1954 if (copy_to_user(argp, &ifr, ifreq_len))
1955 ret = -EFAULT;
1956 break;
1957
1958 case SIOCSIFHWADDR:
1959 /* Set hw address */
1960 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
1961 ifr.ifr_hwaddr.sa_data);
1962
1963 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
1964 break;
1965
1966 case TUNGETSNDBUF:
1967 sndbuf = tfile->socket.sk->sk_sndbuf;
1968 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
1969 ret = -EFAULT;
1970 break;
1971
1972 case TUNSETSNDBUF:
1973 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
1974 ret = -EFAULT;
1975 break;
1976 }
1977
1978 tun->sndbuf = sndbuf;
1979 tun_set_sndbuf(tun);
1980 break;
1981
1982 case TUNGETVNETHDRSZ:
1983 vnet_hdr_sz = tun->vnet_hdr_sz;
1984 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
1985 ret = -EFAULT;
1986 break;
1987
1988 case TUNSETVNETHDRSZ:
1989 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
1990 ret = -EFAULT;
1991 break;
1992 }
1993 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
1994 ret = -EINVAL;
1995 break;
1996 }
1997
1998 tun->vnet_hdr_sz = vnet_hdr_sz;
1999 break;
2000
2001 case TUNATTACHFILTER:
2002 /* Can be set only for TAPs */
2003 ret = -EINVAL;
2004 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
2005 break;
2006 ret = -EFAULT;
2007 if (copy_from_user(&tun->fprog, argp, sizeof(tun->fprog)))
2008 break;
2009
2010 ret = tun_attach_filter(tun);
2011 break;
2012
2013 case TUNDETACHFILTER:
2014 /* Can be set only for TAPs */
2015 ret = -EINVAL;
2016 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
2017 break;
2018 ret = 0;
2019 tun_detach_filter(tun, tun->numqueues);
2020 break;
2021
2022 default:
2023 ret = -EINVAL;
2024 break;
2025 }
2026
2027 unlock:
2028 rtnl_unlock();
2029 if (tun)
2030 tun_put(tun);
2031 return ret;
2032 }
2033
2034 static long tun_chr_ioctl(struct file *file,
2035 unsigned int cmd, unsigned long arg)
2036 {
2037 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
2038 }
2039
2040 #ifdef CONFIG_COMPAT
2041 static long tun_chr_compat_ioctl(struct file *file,
2042 unsigned int cmd, unsigned long arg)
2043 {
2044 switch (cmd) {
2045 case TUNSETIFF:
2046 case TUNGETIFF:
2047 case TUNSETTXFILTER:
2048 case TUNGETSNDBUF:
2049 case TUNSETSNDBUF:
2050 case SIOCGIFHWADDR:
2051 case SIOCSIFHWADDR:
2052 arg = (unsigned long)compat_ptr(arg);
2053 break;
2054 default:
2055 arg = (compat_ulong_t)arg;
2056 break;
2057 }
2058
2059 /*
2060 * compat_ifreq is shorter than ifreq, so we must not access beyond
2061 * the end of that structure. All fields that are used in this
2062 * driver are compatible though, we don't need to convert the
2063 * contents.
2064 */
2065 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
2066 }
2067 #endif /* CONFIG_COMPAT */
2068
2069 static int tun_chr_fasync(int fd, struct file *file, int on)
2070 {
2071 struct tun_file *tfile = file->private_data;
2072 int ret;
2073
2074 if ((ret = fasync_helper(fd, file, on, &tfile->fasync)) < 0)
2075 goto out;
2076
2077 if (on) {
2078 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
2079 if (ret)
2080 goto out;
2081 tfile->flags |= TUN_FASYNC;
2082 } else
2083 tfile->flags &= ~TUN_FASYNC;
2084 ret = 0;
2085 out:
2086 return ret;
2087 }
2088
2089 static int tun_chr_open(struct inode *inode, struct file * file)
2090 {
2091 struct tun_file *tfile;
2092
2093 DBG1(KERN_INFO, "tunX: tun_chr_open\n");
2094
2095 tfile = (struct tun_file *)sk_alloc(&init_net, AF_UNSPEC, GFP_KERNEL,
2096 &tun_proto);
2097 if (!tfile)
2098 return -ENOMEM;
2099 rcu_assign_pointer(tfile->tun, NULL);
2100 tfile->net = get_net(current->nsproxy->net_ns);
2101 tfile->flags = 0;
2102
2103 rcu_assign_pointer(tfile->socket.wq, &tfile->wq);
2104 init_waitqueue_head(&tfile->wq.wait);
2105
2106 tfile->socket.file = file;
2107 tfile->socket.ops = &tun_socket_ops;
2108
2109 sock_init_data(&tfile->socket, &tfile->sk);
2110 sk_change_net(&tfile->sk, tfile->net);
2111
2112 tfile->sk.sk_write_space = tun_sock_write_space;
2113 tfile->sk.sk_sndbuf = INT_MAX;
2114
2115 file->private_data = tfile;
2116 set_bit(SOCK_EXTERNALLY_ALLOCATED, &tfile->socket.flags);
2117 INIT_LIST_HEAD(&tfile->next);
2118
2119 return 0;
2120 }
2121
2122 static int tun_chr_close(struct inode *inode, struct file *file)
2123 {
2124 struct tun_file *tfile = file->private_data;
2125 struct net *net = tfile->net;
2126
2127 tun_detach(tfile, true);
2128 put_net(net);
2129
2130 return 0;
2131 }
2132
2133 static const struct file_operations tun_fops = {
2134 .owner = THIS_MODULE,
2135 .llseek = no_llseek,
2136 .read = do_sync_read,
2137 .aio_read = tun_chr_aio_read,
2138 .write = do_sync_write,
2139 .aio_write = tun_chr_aio_write,
2140 .poll = tun_chr_poll,
2141 .unlocked_ioctl = tun_chr_ioctl,
2142 #ifdef CONFIG_COMPAT
2143 .compat_ioctl = tun_chr_compat_ioctl,
2144 #endif
2145 .open = tun_chr_open,
2146 .release = tun_chr_close,
2147 .fasync = tun_chr_fasync
2148 };
2149
2150 static struct miscdevice tun_miscdev = {
2151 .minor = TUN_MINOR,
2152 .name = "tun",
2153 .nodename = "net/tun",
2154 .fops = &tun_fops,
2155 };
2156
2157 /* ethtool interface */
2158
2159 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
2160 {
2161 cmd->supported = 0;
2162 cmd->advertising = 0;
2163 ethtool_cmd_speed_set(cmd, SPEED_10);
2164 cmd->duplex = DUPLEX_FULL;
2165 cmd->port = PORT_TP;
2166 cmd->phy_address = 0;
2167 cmd->transceiver = XCVR_INTERNAL;
2168 cmd->autoneg = AUTONEG_DISABLE;
2169 cmd->maxtxpkt = 0;
2170 cmd->maxrxpkt = 0;
2171 return 0;
2172 }
2173
2174 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
2175 {
2176 struct tun_struct *tun = netdev_priv(dev);
2177
2178 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
2179 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
2180
2181 switch (tun->flags & TUN_TYPE_MASK) {
2182 case TUN_TUN_DEV:
2183 strlcpy(info->bus_info, "tun", sizeof(info->bus_info));
2184 break;
2185 case TUN_TAP_DEV:
2186 strlcpy(info->bus_info, "tap", sizeof(info->bus_info));
2187 break;
2188 }
2189 }
2190
2191 static u32 tun_get_msglevel(struct net_device *dev)
2192 {
2193 #ifdef TUN_DEBUG
2194 struct tun_struct *tun = netdev_priv(dev);
2195 return tun->debug;
2196 #else
2197 return -EOPNOTSUPP;
2198 #endif
2199 }
2200
2201 static void tun_set_msglevel(struct net_device *dev, u32 value)
2202 {
2203 #ifdef TUN_DEBUG
2204 struct tun_struct *tun = netdev_priv(dev);
2205 tun->debug = value;
2206 #endif
2207 }
2208
2209 static const struct ethtool_ops tun_ethtool_ops = {
2210 .get_settings = tun_get_settings,
2211 .get_drvinfo = tun_get_drvinfo,
2212 .get_msglevel = tun_get_msglevel,
2213 .set_msglevel = tun_set_msglevel,
2214 .get_link = ethtool_op_get_link,
2215 };
2216
2217
2218 static int __init tun_init(void)
2219 {
2220 int ret = 0;
2221
2222 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
2223 pr_info("%s\n", DRV_COPYRIGHT);
2224
2225 ret = rtnl_link_register(&tun_link_ops);
2226 if (ret) {
2227 pr_err("Can't register link_ops\n");
2228 goto err_linkops;
2229 }
2230
2231 ret = misc_register(&tun_miscdev);
2232 if (ret) {
2233 pr_err("Can't register misc device %d\n", TUN_MINOR);
2234 goto err_misc;
2235 }
2236 return 0;
2237 err_misc:
2238 rtnl_link_unregister(&tun_link_ops);
2239 err_linkops:
2240 return ret;
2241 }
2242
2243 static void tun_cleanup(void)
2244 {
2245 misc_deregister(&tun_miscdev);
2246 rtnl_link_unregister(&tun_link_ops);
2247 }
2248
2249 /* Get an underlying socket object from tun file. Returns error unless file is
2250 * attached to a device. The returned object works like a packet socket, it
2251 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
2252 * holding a reference to the file for as long as the socket is in use. */
2253 struct socket *tun_get_socket(struct file *file)
2254 {
2255 struct tun_file *tfile;
2256 if (file->f_op != &tun_fops)
2257 return ERR_PTR(-EINVAL);
2258 tfile = file->private_data;
2259 if (!tfile)
2260 return ERR_PTR(-EBADFD);
2261 return &tfile->socket;
2262 }
2263 EXPORT_SYMBOL_GPL(tun_get_socket);
2264
2265 module_init(tun_init);
2266 module_exit(tun_cleanup);
2267 MODULE_DESCRIPTION(DRV_DESCRIPTION);
2268 MODULE_AUTHOR(DRV_COPYRIGHT);
2269 MODULE_LICENSE("GPL");
2270 MODULE_ALIAS_MISCDEV(TUN_MINOR);
2271 MODULE_ALIAS("devname:net/tun");
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree