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Merge branch 'vhost-net-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mst...
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / net / tun.c
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CommitLineData
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
78static int debug;
79
80#define tun_debug(level, tun, fmt, args...) \
81do { \
82 if (tun->debug) \
83 netdev_printk(level, tun->dev, fmt, ##args); \
84} while (0)
85#define DBG1(level, fmt, args...) \
86do { \
87 if (debug == 2) \
88 printk(level fmt, ##args); \
89} while (0)
90#else
91#define tun_debug(level, tun, fmt, args...) \
92do { \
93 if (0) \
94 netdev_printk(level, tun->dev, fmt, ##args); \
95} while (0)
96#define DBG1(level, fmt, args...) \
97do { \
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
106struct 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 */
131struct 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};
142
143struct tun_flow_entry {
144 struct hlist_node hash_link;
145 struct rcu_head rcu;
146 struct tun_struct *tun;
147
148 u32 rxhash;
149 int queue_index;
150 unsigned long updated;
151};
152
153#define TUN_NUM_FLOW_ENTRIES 1024
154
155/* Since the socket were moved to tun_file, to preserve the behavior of persist
156 * device, socket filter, sndbuf and vnet header size were restore when the
157 * file were attached to a persist device.
158 */
159struct tun_struct {
160 struct tun_file __rcu *tfiles[MAX_TAP_QUEUES];
161 unsigned int numqueues;
162 unsigned int flags;
163 kuid_t owner;
164 kgid_t group;
165
166 struct net_device *dev;
167 netdev_features_t set_features;
168#define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
169 NETIF_F_TSO6|NETIF_F_UFO)
170
171 int vnet_hdr_sz;
172 int sndbuf;
173 struct tap_filter txflt;
174 struct sock_fprog fprog;
175 /* protected by rtnl lock */
176 bool filter_attached;
177#ifdef TUN_DEBUG
178 int debug;
179#endif
180 spinlock_t lock;
181 struct kmem_cache *flow_cache;
182 struct hlist_head flows[TUN_NUM_FLOW_ENTRIES];
183 struct timer_list flow_gc_timer;
184 unsigned long ageing_time;
185};
186
187static inline u32 tun_hashfn(u32 rxhash)
188{
189 return rxhash & 0x3ff;
190}
191
192static struct tun_flow_entry *tun_flow_find(struct hlist_head *head, u32 rxhash)
193{
194 struct tun_flow_entry *e;
195 struct hlist_node *n;
196
197 hlist_for_each_entry_rcu(e, n, head, hash_link) {
198 if (e->rxhash == rxhash)
199 return e;
200 }
201 return NULL;
202}
203
204static struct tun_flow_entry *tun_flow_create(struct tun_struct *tun,
205 struct hlist_head *head,
206 u32 rxhash, u16 queue_index)
207{
208 struct tun_flow_entry *e = kmem_cache_alloc(tun->flow_cache,
209 GFP_ATOMIC);
210 if (e) {
211 tun_debug(KERN_INFO, tun, "create flow: hash %u index %u\n",
212 rxhash, queue_index);
213 e->updated = jiffies;
214 e->rxhash = rxhash;
215 e->queue_index = queue_index;
216 e->tun = tun;
217 hlist_add_head_rcu(&e->hash_link, head);
218 }
219 return e;
220}
221
222static void tun_flow_free(struct rcu_head *head)
223{
224 struct tun_flow_entry *e
225 = container_of(head, struct tun_flow_entry, rcu);
226 kmem_cache_free(e->tun->flow_cache, e);
227}
228
229static void tun_flow_delete(struct tun_struct *tun, struct tun_flow_entry *e)
230{
231 tun_debug(KERN_INFO, tun, "delete flow: hash %u index %u\n",
232 e->rxhash, e->queue_index);
233 hlist_del_rcu(&e->hash_link);
234 call_rcu(&e->rcu, tun_flow_free);
235}
236
237static void tun_flow_flush(struct tun_struct *tun)
238{
239 int i;
240
241 spin_lock_bh(&tun->lock);
242 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
243 struct tun_flow_entry *e;
244 struct hlist_node *h, *n;
245
246 hlist_for_each_entry_safe(e, h, n, &tun->flows[i], hash_link)
247 tun_flow_delete(tun, e);
248 }
249 spin_unlock_bh(&tun->lock);
250}
251
252static void tun_flow_delete_by_queue(struct tun_struct *tun, u16 queue_index)
253{
254 int i;
255
256 spin_lock_bh(&tun->lock);
257 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
258 struct tun_flow_entry *e;
259 struct hlist_node *h, *n;
260
261 hlist_for_each_entry_safe(e, h, n, &tun->flows[i], hash_link) {
262 if (e->queue_index == queue_index)
263 tun_flow_delete(tun, e);
264 }
265 }
266 spin_unlock_bh(&tun->lock);
267}
268
269static void tun_flow_cleanup(unsigned long data)
270{
271 struct tun_struct *tun = (struct tun_struct *)data;
272 unsigned long delay = tun->ageing_time;
273 unsigned long next_timer = jiffies + delay;
274 unsigned long count = 0;
275 int i;
276
277 tun_debug(KERN_INFO, tun, "tun_flow_cleanup\n");
278
279 spin_lock_bh(&tun->lock);
280 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
281 struct tun_flow_entry *e;
282 struct hlist_node *h, *n;
283
284 hlist_for_each_entry_safe(e, h, n, &tun->flows[i], hash_link) {
285 unsigned long this_timer;
286 count++;
287 this_timer = e->updated + delay;
288 if (time_before_eq(this_timer, jiffies))
289 tun_flow_delete(tun, e);
290 else if (time_before(this_timer, next_timer))
291 next_timer = this_timer;
292 }
293 }
294
295 if (count)
296 mod_timer(&tun->flow_gc_timer, round_jiffies_up(next_timer));
297 spin_unlock_bh(&tun->lock);
298}
299
300static void tun_flow_update(struct tun_struct *tun, struct sk_buff *skb,
301 u16 queue_index)
302{
303 struct hlist_head *head;
304 struct tun_flow_entry *e;
305 unsigned long delay = tun->ageing_time;
306 u32 rxhash = skb_get_rxhash(skb);
307
308 if (!rxhash)
309 return;
310 else
311 head = &tun->flows[tun_hashfn(rxhash)];
312
313 rcu_read_lock();
314
315 if (tun->numqueues == 1)
316 goto unlock;
317
318 e = tun_flow_find(head, rxhash);
319 if (likely(e)) {
320 /* TODO: keep queueing to old queue until it's empty? */
321 e->queue_index = queue_index;
322 e->updated = jiffies;
323 } else {
324 spin_lock_bh(&tun->lock);
325 if (!tun_flow_find(head, rxhash))
326 tun_flow_create(tun, head, rxhash, queue_index);
327
328 if (!timer_pending(&tun->flow_gc_timer))
329 mod_timer(&tun->flow_gc_timer,
330 round_jiffies_up(jiffies + delay));
331 spin_unlock_bh(&tun->lock);
332 }
333
334unlock:
335 rcu_read_unlock();
336}
337
338/* We try to identify a flow through its rxhash first. The reason that
339 * we do not check rxq no. is becuase some cards(e.g 82599), chooses
340 * the rxq based on the txq where the last packet of the flow comes. As
341 * the userspace application move between processors, we may get a
342 * different rxq no. here. If we could not get rxhash, then we would
343 * hope the rxq no. may help here.
344 */
345static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb)
346{
347 struct tun_struct *tun = netdev_priv(dev);
348 struct tun_flow_entry *e;
349 u32 txq = 0;
350 u32 numqueues = 0;
351
352 rcu_read_lock();
353 numqueues = tun->numqueues;
354
355 txq = skb_get_rxhash(skb);
356 if (txq) {
357 e = tun_flow_find(&tun->flows[tun_hashfn(txq)], txq);
358 if (e)
359 txq = e->queue_index;
360 else
361 /* use multiply and shift instead of expensive divide */
362 txq = ((u64)txq * numqueues) >> 32;
363 } else if (likely(skb_rx_queue_recorded(skb))) {
364 txq = skb_get_rx_queue(skb);
365 while (unlikely(txq >= numqueues))
366 txq -= numqueues;
367 }
368
369 rcu_read_unlock();
370 return txq;
371}
372
373static inline bool tun_not_capable(struct tun_struct *tun)
374{
375 const struct cred *cred = current_cred();
376 struct net *net = dev_net(tun->dev);
377
378 return ((uid_valid(tun->owner) && !uid_eq(cred->euid, tun->owner)) ||
379 (gid_valid(tun->group) && !in_egroup_p(tun->group))) &&
380 !ns_capable(net->user_ns, CAP_NET_ADMIN);
381}
382
383static void tun_set_real_num_queues(struct tun_struct *tun)
384{
385 netif_set_real_num_tx_queues(tun->dev, tun->numqueues);
386 netif_set_real_num_rx_queues(tun->dev, tun->numqueues);
387}
388
389static void __tun_detach(struct tun_file *tfile, bool clean)
390{
391 struct tun_file *ntfile;
392 struct tun_struct *tun;
393 struct net_device *dev;
394
395 tun = rcu_dereference_protected(tfile->tun,
396 lockdep_rtnl_is_held());
397 if (tun) {
398 u16 index = tfile->queue_index;
399 BUG_ON(index >= tun->numqueues);
400 dev = tun->dev;
401
402 rcu_assign_pointer(tun->tfiles[index],
403 tun->tfiles[tun->numqueues - 1]);
404 rcu_assign_pointer(tfile->tun, NULL);
405 ntfile = rcu_dereference_protected(tun->tfiles[index],
406 lockdep_rtnl_is_held());
407 ntfile->queue_index = index;
408
409 --tun->numqueues;
410 sock_put(&tfile->sk);
411
412 synchronize_net();
413 tun_flow_delete_by_queue(tun, tun->numqueues + 1);
414 /* Drop read queue */
415 skb_queue_purge(&tfile->sk.sk_receive_queue);
416 tun_set_real_num_queues(tun);
417
418 if (tun->numqueues == 0 && !(tun->flags & TUN_PERSIST))
419 if (dev->reg_state == NETREG_REGISTERED)
420 unregister_netdevice(dev);
421 }
422
423 if (clean) {
424 BUG_ON(!test_bit(SOCK_EXTERNALLY_ALLOCATED,
425 &tfile->socket.flags));
426 sk_release_kernel(&tfile->sk);
427 }
428}
429
430static void tun_detach(struct tun_file *tfile, bool clean)
431{
432 rtnl_lock();
433 __tun_detach(tfile, clean);
434 rtnl_unlock();
435}
436
437static void tun_detach_all(struct net_device *dev)
438{
439 struct tun_struct *tun = netdev_priv(dev);
440 struct tun_file *tfile;
441 int i, n = tun->numqueues;
442
443 for (i = 0; i < n; i++) {
444 tfile = rcu_dereference_protected(tun->tfiles[i],
445 lockdep_rtnl_is_held());
446 BUG_ON(!tfile);
447 wake_up_all(&tfile->wq.wait);
448 rcu_assign_pointer(tfile->tun, NULL);
449 --tun->numqueues;
450 }
451 BUG_ON(tun->numqueues != 0);
452
453 synchronize_net();
454 for (i = 0; i < n; i++) {
455 tfile = rcu_dereference_protected(tun->tfiles[i],
456 lockdep_rtnl_is_held());
457 /* Drop read queue */
458 skb_queue_purge(&tfile->sk.sk_receive_queue);
459 sock_put(&tfile->sk);
460 }
461}
462
463static int tun_attach(struct tun_struct *tun, struct file *file)
464{
465 struct tun_file *tfile = file->private_data;
466 int err;
467
468 err = -EINVAL;
469 if (rcu_dereference_protected(tfile->tun, lockdep_rtnl_is_held()))
470 goto out;
471
472 err = -EBUSY;
473 if (!(tun->flags & TUN_TAP_MQ) && tun->numqueues == 1)
474 goto out;
475
476 err = -E2BIG;
477 if (tun->numqueues == MAX_TAP_QUEUES)
478 goto out;
479
480 err = 0;
481
482 /* Re-attach the filter to presist device */
483 if (tun->filter_attached == true) {
484 err = sk_attach_filter(&tun->fprog, tfile->socket.sk);
485 if (!err)
486 goto out;
487 }
488 tfile->queue_index = tun->numqueues;
489 rcu_assign_pointer(tfile->tun, tun);
490 rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile);
491 sock_hold(&tfile->sk);
492 tun->numqueues++;
493
494 tun_set_real_num_queues(tun);
495
496 /* device is allowed to go away first, so no need to hold extra
497 * refcnt.
498 */
499
500out:
501 return err;
502}
503
504static struct tun_struct *__tun_get(struct tun_file *tfile)
505{
506 struct tun_struct *tun;
507
508 rcu_read_lock();
509 tun = rcu_dereference(tfile->tun);
510 if (tun)
511 dev_hold(tun->dev);
512 rcu_read_unlock();
513
514 return tun;
515}
516
517static struct tun_struct *tun_get(struct file *file)
518{
519 return __tun_get(file->private_data);
520}
521
522static void tun_put(struct tun_struct *tun)
523{
524 dev_put(tun->dev);
525}
526
527/* TAP filtering */
528static void addr_hash_set(u32 *mask, const u8 *addr)
529{
530 int n = ether_crc(ETH_ALEN, addr) >> 26;
531 mask[n >> 5] |= (1 << (n & 31));
532}
533
534static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
535{
536 int n = ether_crc(ETH_ALEN, addr) >> 26;
537 return mask[n >> 5] & (1 << (n & 31));
538}
539
540static int update_filter(struct tap_filter *filter, void __user *arg)
541{
542 struct { u8 u[ETH_ALEN]; } *addr;
543 struct tun_filter uf;
544 int err, alen, n, nexact;
545
546 if (copy_from_user(&uf, arg, sizeof(uf)))
547 return -EFAULT;
548
549 if (!uf.count) {
550 /* Disabled */
551 filter->count = 0;
552 return 0;
553 }
554
555 alen = ETH_ALEN * uf.count;
556 addr = kmalloc(alen, GFP_KERNEL);
557 if (!addr)
558 return -ENOMEM;
559
560 if (copy_from_user(addr, arg + sizeof(uf), alen)) {
561 err = -EFAULT;
562 goto done;
563 }
564
565 /* The filter is updated without holding any locks. Which is
566 * perfectly safe. We disable it first and in the worst
567 * case we'll accept a few undesired packets. */
568 filter->count = 0;
569 wmb();
570
571 /* Use first set of addresses as an exact filter */
572 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
573 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
574
575 nexact = n;
576
577 /* Remaining multicast addresses are hashed,
578 * unicast will leave the filter disabled. */
579 memset(filter->mask, 0, sizeof(filter->mask));
580 for (; n < uf.count; n++) {
581 if (!is_multicast_ether_addr(addr[n].u)) {
582 err = 0; /* no filter */
583 goto done;
584 }
585 addr_hash_set(filter->mask, addr[n].u);
586 }
587
588 /* For ALLMULTI just set the mask to all ones.
589 * This overrides the mask populated above. */
590 if ((uf.flags & TUN_FLT_ALLMULTI))
591 memset(filter->mask, ~0, sizeof(filter->mask));
592
593 /* Now enable the filter */
594 wmb();
595 filter->count = nexact;
596
597 /* Return the number of exact filters */
598 err = nexact;
599
600done:
601 kfree(addr);
602 return err;
603}
604
605/* Returns: 0 - drop, !=0 - accept */
606static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
607{
608 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
609 * at this point. */
610 struct ethhdr *eh = (struct ethhdr *) skb->data;
611 int i;
612
613 /* Exact match */
614 for (i = 0; i < filter->count; i++)
615 if (ether_addr_equal(eh->h_dest, filter->addr[i]))
616 return 1;
617
618 /* Inexact match (multicast only) */
619 if (is_multicast_ether_addr(eh->h_dest))
620 return addr_hash_test(filter->mask, eh->h_dest);
621
622 return 0;
623}
624
625/*
626 * Checks whether the packet is accepted or not.
627 * Returns: 0 - drop, !=0 - accept
628 */
629static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
630{
631 if (!filter->count)
632 return 1;
633
634 return run_filter(filter, skb);
635}
636
637/* Network device part of the driver */
638
639static const struct ethtool_ops tun_ethtool_ops;
640
641/* Net device detach from fd. */
642static void tun_net_uninit(struct net_device *dev)
643{
644 tun_detach_all(dev);
645}
646
647/* Net device open. */
648static int tun_net_open(struct net_device *dev)
649{
650 netif_tx_start_all_queues(dev);
651 return 0;
652}
653
654/* Net device close. */
655static int tun_net_close(struct net_device *dev)
656{
657 netif_tx_stop_all_queues(dev);
658 return 0;
659}
660
661/* Net device start xmit */
662static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
663{
664 struct tun_struct *tun = netdev_priv(dev);
665 int txq = skb->queue_mapping;
666 struct tun_file *tfile;
667
668 rcu_read_lock();
669 tfile = rcu_dereference(tun->tfiles[txq]);
670
671 /* Drop packet if interface is not attached */
672 if (txq >= tun->numqueues)
673 goto drop;
674
675 tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len);
676
677 BUG_ON(!tfile);
678
679 /* Drop if the filter does not like it.
680 * This is a noop if the filter is disabled.
681 * Filter can be enabled only for the TAP devices. */
682 if (!check_filter(&tun->txflt, skb))
683 goto drop;
684
685 if (tfile->socket.sk->sk_filter &&
686 sk_filter(tfile->socket.sk, skb))
687 goto drop;
688
689 /* Limit the number of packets queued by dividing txq length with the
690 * number of queues.
691 */
692 if (skb_queue_len(&tfile->socket.sk->sk_receive_queue)
693 >= dev->tx_queue_len / tun->numqueues)
694 goto drop;
695
696 /* Orphan the skb - required as we might hang on to it
697 * for indefinite time. */
698 if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
699 goto drop;
700 skb_orphan(skb);
701
702 /* Enqueue packet */
703 skb_queue_tail(&tfile->socket.sk->sk_receive_queue, skb);
704
705 /* Notify and wake up reader process */
706 if (tfile->flags & TUN_FASYNC)
707 kill_fasync(&tfile->fasync, SIGIO, POLL_IN);
708 wake_up_interruptible_poll(&tfile->wq.wait, POLLIN |
709 POLLRDNORM | POLLRDBAND);
710
711 rcu_read_unlock();
712 return NETDEV_TX_OK;
713
714drop:
715 dev->stats.tx_dropped++;
716 skb_tx_error(skb);
717 kfree_skb(skb);
718 rcu_read_unlock();
719 return NETDEV_TX_OK;
720}
721
722static void tun_net_mclist(struct net_device *dev)
723{
724 /*
725 * This callback is supposed to deal with mc filter in
726 * _rx_ path and has nothing to do with the _tx_ path.
727 * In rx path we always accept everything userspace gives us.
728 */
729}
730
731#define MIN_MTU 68
732#define MAX_MTU 65535
733
734static int
735tun_net_change_mtu(struct net_device *dev, int new_mtu)
736{
737 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
738 return -EINVAL;
739 dev->mtu = new_mtu;
740 return 0;
741}
742
743static netdev_features_t tun_net_fix_features(struct net_device *dev,
744 netdev_features_t features)
745{
746 struct tun_struct *tun = netdev_priv(dev);
747
748 return (features & tun->set_features) | (features & ~TUN_USER_FEATURES);
749}
750#ifdef CONFIG_NET_POLL_CONTROLLER
751static void tun_poll_controller(struct net_device *dev)
752{
753 /*
754 * Tun only receives frames when:
755 * 1) the char device endpoint gets data from user space
756 * 2) the tun socket gets a sendmsg call from user space
757 * Since both of those are syncronous operations, we are guaranteed
758 * never to have pending data when we poll for it
759 * so theres nothing to do here but return.
760 * We need this though so netpoll recognizes us as an interface that
761 * supports polling, which enables bridge devices in virt setups to
762 * still use netconsole
763 */
764 return;
765}
766#endif
767static const struct net_device_ops tun_netdev_ops = {
768 .ndo_uninit = tun_net_uninit,
769 .ndo_open = tun_net_open,
770 .ndo_stop = tun_net_close,
771 .ndo_start_xmit = tun_net_xmit,
772 .ndo_change_mtu = tun_net_change_mtu,
773 .ndo_fix_features = tun_net_fix_features,
774 .ndo_select_queue = tun_select_queue,
775#ifdef CONFIG_NET_POLL_CONTROLLER
776 .ndo_poll_controller = tun_poll_controller,
777#endif
778};
779
780static const struct net_device_ops tap_netdev_ops = {
781 .ndo_uninit = tun_net_uninit,
782 .ndo_open = tun_net_open,
783 .ndo_stop = tun_net_close,
784 .ndo_start_xmit = tun_net_xmit,
785 .ndo_change_mtu = tun_net_change_mtu,
786 .ndo_fix_features = tun_net_fix_features,
787 .ndo_set_rx_mode = tun_net_mclist,
788 .ndo_set_mac_address = eth_mac_addr,
789 .ndo_validate_addr = eth_validate_addr,
790 .ndo_select_queue = tun_select_queue,
791#ifdef CONFIG_NET_POLL_CONTROLLER
792 .ndo_poll_controller = tun_poll_controller,
793#endif
794};
795
796static int tun_flow_init(struct tun_struct *tun)
797{
798 int i;
799
800 tun->flow_cache = kmem_cache_create("tun_flow_cache",
801 sizeof(struct tun_flow_entry), 0, 0,
802 NULL);
803 if (!tun->flow_cache)
804 return -ENOMEM;
805
806 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++)
807 INIT_HLIST_HEAD(&tun->flows[i]);
808
809 tun->ageing_time = TUN_FLOW_EXPIRE;
810 setup_timer(&tun->flow_gc_timer, tun_flow_cleanup, (unsigned long)tun);
811 mod_timer(&tun->flow_gc_timer,
812 round_jiffies_up(jiffies + tun->ageing_time));
813
814 return 0;
815}
816
817static void tun_flow_uninit(struct tun_struct *tun)
818{
819 del_timer_sync(&tun->flow_gc_timer);
820 tun_flow_flush(tun);
821
822 /* Wait for completion of call_rcu()'s */
823 rcu_barrier();
824 kmem_cache_destroy(tun->flow_cache);
825}
826
827/* Initialize net device. */
828static void tun_net_init(struct net_device *dev)
829{
830 struct tun_struct *tun = netdev_priv(dev);
831
832 switch (tun->flags & TUN_TYPE_MASK) {
833 case TUN_TUN_DEV:
834 dev->netdev_ops = &tun_netdev_ops;
835
836 /* Point-to-Point TUN Device */
837 dev->hard_header_len = 0;
838 dev->addr_len = 0;
839 dev->mtu = 1500;
840
841 /* Zero header length */
842 dev->type = ARPHRD_NONE;
843 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
844 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
845 break;
846
847 case TUN_TAP_DEV:
848 dev->netdev_ops = &tap_netdev_ops;
849 /* Ethernet TAP Device */
850 ether_setup(dev);
851 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
852
853 eth_hw_addr_random(dev);
854
855 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
856 break;
857 }
858}
859
860/* Character device part */
861
862/* Poll */
863static unsigned int tun_chr_poll(struct file *file, poll_table *wait)
864{
865 struct tun_file *tfile = file->private_data;
866 struct tun_struct *tun = __tun_get(tfile);
867 struct sock *sk;
868 unsigned int mask = 0;
869
870 if (!tun)
871 return POLLERR;
872
873 sk = tfile->socket.sk;
874
875 tun_debug(KERN_INFO, tun, "tun_chr_poll\n");
876
877 poll_wait(file, &tfile->wq.wait, wait);
878
879 if (!skb_queue_empty(&sk->sk_receive_queue))
880 mask |= POLLIN | POLLRDNORM;
881
882 if (sock_writeable(sk) ||
883 (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
884 sock_writeable(sk)))
885 mask |= POLLOUT | POLLWRNORM;
886
887 if (tun->dev->reg_state != NETREG_REGISTERED)
888 mask = POLLERR;
889
890 tun_put(tun);
891 return mask;
892}
893
894/* prepad is the amount to reserve at front. len is length after that.
895 * linear is a hint as to how much to copy (usually headers). */
896static struct sk_buff *tun_alloc_skb(struct tun_file *tfile,
897 size_t prepad, size_t len,
898 size_t linear, int noblock)
899{
900 struct sock *sk = tfile->socket.sk;
901 struct sk_buff *skb;
902 int err;
903
904 /* Under a page? Don't bother with paged skb. */
905 if (prepad + len < PAGE_SIZE || !linear)
906 linear = len;
907
908 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
909 &err);
910 if (!skb)
911 return ERR_PTR(err);
912
913 skb_reserve(skb, prepad);
914 skb_put(skb, linear);
915 skb->data_len = len - linear;
916 skb->len += len - linear;
917
918 return skb;
919}
920
921/* set skb frags from iovec, this can move to core network code for reuse */
922static int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *from,
923 int offset, size_t count)
924{
925 int len = iov_length(from, count) - offset;
926 int copy = skb_headlen(skb);
927 int size, offset1 = 0;
928 int i = 0;
929
930 /* Skip over from offset */
931 while (count && (offset >= from->iov_len)) {
932 offset -= from->iov_len;
933 ++from;
934 --count;
935 }
936
937 /* copy up to skb headlen */
938 while (count && (copy > 0)) {
939 size = min_t(unsigned int, copy, from->iov_len - offset);
940 if (copy_from_user(skb->data + offset1, from->iov_base + offset,
941 size))
942 return -EFAULT;
943 if (copy > size) {
944 ++from;
945 --count;
946 offset = 0;
947 } else
948 offset += size;
949 copy -= size;
950 offset1 += size;
951 }
952
953 if (len == offset1)
954 return 0;
955
956 while (count--) {
957 struct page *page[MAX_SKB_FRAGS];
958 int num_pages;
959 unsigned long base;
960 unsigned long truesize;
961
962 len = from->iov_len - offset;
963 if (!len) {
964 offset = 0;
965 ++from;
966 continue;
967 }
968 base = (unsigned long)from->iov_base + offset;
969 size = ((base & ~PAGE_MASK) + len + ~PAGE_MASK) >> PAGE_SHIFT;
970 if (i + size > MAX_SKB_FRAGS)
971 return -EMSGSIZE;
972 num_pages = get_user_pages_fast(base, size, 0, &page[i]);
973 if (num_pages != size) {
974 for (i = 0; i < num_pages; i++)
975 put_page(page[i]);
976 return -EFAULT;
977 }
978 truesize = size * PAGE_SIZE;
979 skb->data_len += len;
980 skb->len += len;
981 skb->truesize += truesize;
982 atomic_add(truesize, &skb->sk->sk_wmem_alloc);
983 while (len) {
984 int off = base & ~PAGE_MASK;
985 int size = min_t(int, len, PAGE_SIZE - off);
986 __skb_fill_page_desc(skb, i, page[i], off, size);
987 skb_shinfo(skb)->nr_frags++;
988 /* increase sk_wmem_alloc */
989 base += size;
990 len -= size;
991 i++;
992 }
993 offset = 0;
994 ++from;
995 }
996 return 0;
997}
998
999/* Get packet from user space buffer */
1000static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
1001 void *msg_control, const struct iovec *iv,
1002 size_t total_len, size_t count, int noblock)
1003{
1004 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
1005 struct sk_buff *skb;
1006 size_t len = total_len, align = NET_SKB_PAD;
1007 struct virtio_net_hdr gso = { 0 };
1008 int offset = 0;
1009 int copylen;
1010 bool zerocopy = false;
1011 int err;
1012
1013 if (!(tun->flags & TUN_NO_PI)) {
1014 if ((len -= sizeof(pi)) > total_len)
1015 return -EINVAL;
1016
1017 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
1018 return -EFAULT;
1019 offset += sizeof(pi);
1020 }
1021
1022 if (tun->flags & TUN_VNET_HDR) {
1023 if ((len -= tun->vnet_hdr_sz) > total_len)
1024 return -EINVAL;
1025
1026 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
1027 return -EFAULT;
1028
1029 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
1030 gso.csum_start + gso.csum_offset + 2 > gso.hdr_len)
1031 gso.hdr_len = gso.csum_start + gso.csum_offset + 2;
1032
1033 if (gso.hdr_len > len)
1034 return -EINVAL;
1035 offset += tun->vnet_hdr_sz;
1036 }
1037
1038 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
1039 align += NET_IP_ALIGN;
1040 if (unlikely(len < ETH_HLEN ||
1041 (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
1042 return -EINVAL;
1043 }
1044
1045 if (msg_control)
1046 zerocopy = true;
1047
1048 if (zerocopy) {
1049 /* Userspace may produce vectors with count greater than
1050 * MAX_SKB_FRAGS, so we need to linearize parts of the skb
1051 * to let the rest of data to be fit in the frags.
1052 */
1053 if (count > MAX_SKB_FRAGS) {
1054 copylen = iov_length(iv, count - MAX_SKB_FRAGS);
1055 if (copylen < offset)
1056 copylen = 0;
1057 else
1058 copylen -= offset;
1059 } else
1060 copylen = 0;
1061 /* There are 256 bytes to be copied in skb, so there is enough
1062 * room for skb expand head in case it is used.
1063 * The rest of the buffer is mapped from userspace.
1064 */
1065 if (copylen < gso.hdr_len)
1066 copylen = gso.hdr_len;
1067 if (!copylen)
1068 copylen = GOODCOPY_LEN;
1069 } else
1070 copylen = len;
1071
1072 skb = tun_alloc_skb(tfile, align, copylen, gso.hdr_len, noblock);
1073 if (IS_ERR(skb)) {
1074 if (PTR_ERR(skb) != -EAGAIN)
1075 tun->dev->stats.rx_dropped++;
1076 return PTR_ERR(skb);
1077 }
1078
1079 if (zerocopy)
1080 err = zerocopy_sg_from_iovec(skb, iv, offset, count);
1081 else
1082 err = skb_copy_datagram_from_iovec(skb, 0, iv, offset, len);
1083
1084 if (err) {
1085 tun->dev->stats.rx_dropped++;
1086 kfree_skb(skb);
1087 return -EFAULT;
1088 }
1089
1090 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
1091 if (!skb_partial_csum_set(skb, gso.csum_start,
1092 gso.csum_offset)) {
1093 tun->dev->stats.rx_frame_errors++;
1094 kfree_skb(skb);
1095 return -EINVAL;
1096 }
1097 }
1098
1099 switch (tun->flags & TUN_TYPE_MASK) {
1100 case TUN_TUN_DEV:
1101 if (tun->flags & TUN_NO_PI) {
1102 switch (skb->data[0] & 0xf0) {
1103 case 0x40:
1104 pi.proto = htons(ETH_P_IP);
1105 break;
1106 case 0x60:
1107 pi.proto = htons(ETH_P_IPV6);
1108 break;
1109 default:
1110 tun->dev->stats.rx_dropped++;
1111 kfree_skb(skb);
1112 return -EINVAL;
1113 }
1114 }
1115
1116 skb_reset_mac_header(skb);
1117 skb->protocol = pi.proto;
1118 skb->dev = tun->dev;
1119 break;
1120 case TUN_TAP_DEV:
1121 skb->protocol = eth_type_trans(skb, tun->dev);
1122 break;
1123 }
1124
1125 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
1126 pr_debug("GSO!\n");
1127 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
1128 case VIRTIO_NET_HDR_GSO_TCPV4:
1129 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
1130 break;
1131 case VIRTIO_NET_HDR_GSO_TCPV6:
1132 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
1133 break;
1134 case VIRTIO_NET_HDR_GSO_UDP:
1135 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
1136 break;
1137 default:
1138 tun->dev->stats.rx_frame_errors++;
1139 kfree_skb(skb);
1140 return -EINVAL;
1141 }
1142
1143 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
1144 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
1145
1146 skb_shinfo(skb)->gso_size = gso.gso_size;
1147 if (skb_shinfo(skb)->gso_size == 0) {
1148 tun->dev->stats.rx_frame_errors++;
1149 kfree_skb(skb);
1150 return -EINVAL;
1151 }
1152
1153 /* Header must be checked, and gso_segs computed. */
1154 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
1155 skb_shinfo(skb)->gso_segs = 0;
1156 }
1157
1158 /* copy skb_ubuf_info for callback when skb has no error */
1159 if (zerocopy) {
1160 skb_shinfo(skb)->destructor_arg = msg_control;
1161 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1162 }
1163
1164 netif_rx_ni(skb);
1165
1166 tun->dev->stats.rx_packets++;
1167 tun->dev->stats.rx_bytes += len;
1168
1169 tun_flow_update(tun, skb, tfile->queue_index);
1170 return total_len;
1171}
1172
1173static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
1174 unsigned long count, loff_t pos)
1175{
1176 struct file *file = iocb->ki_filp;
1177 struct tun_struct *tun = tun_get(file);
1178 struct tun_file *tfile = file->private_data;
1179 ssize_t result;
1180
1181 if (!tun)
1182 return -EBADFD;
1183
1184 tun_debug(KERN_INFO, tun, "tun_chr_write %ld\n", count);
1185
1186 result = tun_get_user(tun, tfile, NULL, iv, iov_length(iv, count),
1187 count, file->f_flags & O_NONBLOCK);
1188
1189 tun_put(tun);
1190 return result;
1191}
1192
1193/* Put packet to the user space buffer */
1194static ssize_t tun_put_user(struct tun_struct *tun,
1195 struct tun_file *tfile,
1196 struct sk_buff *skb,
1197 const struct iovec *iv, int len)
1198{
1199 struct tun_pi pi = { 0, skb->protocol };
1200 ssize_t total = 0;
1201
1202 if (!(tun->flags & TUN_NO_PI)) {
1203 if ((len -= sizeof(pi)) < 0)
1204 return -EINVAL;
1205
1206 if (len < skb->len) {
1207 /* Packet will be striped */
1208 pi.flags |= TUN_PKT_STRIP;
1209 }
1210
1211 if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi)))
1212 return -EFAULT;
1213 total += sizeof(pi);
1214 }
1215
1216 if (tun->flags & TUN_VNET_HDR) {
1217 struct virtio_net_hdr gso = { 0 }; /* no info leak */
1218 if ((len -= tun->vnet_hdr_sz) < 0)
1219 return -EINVAL;
1220
1221 if (skb_is_gso(skb)) {
1222 struct skb_shared_info *sinfo = skb_shinfo(skb);
1223
1224 /* This is a hint as to how much should be linear. */
1225 gso.hdr_len = skb_headlen(skb);
1226 gso.gso_size = sinfo->gso_size;
1227 if (sinfo->gso_type & SKB_GSO_TCPV4)
1228 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
1229 else if (sinfo->gso_type & SKB_GSO_TCPV6)
1230 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
1231 else if (sinfo->gso_type & SKB_GSO_UDP)
1232 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
1233 else {
1234 pr_err("unexpected GSO type: "
1235 "0x%x, gso_size %d, hdr_len %d\n",
1236 sinfo->gso_type, gso.gso_size,
1237 gso.hdr_len);
1238 print_hex_dump(KERN_ERR, "tun: ",
1239 DUMP_PREFIX_NONE,
1240 16, 1, skb->head,
1241 min((int)gso.hdr_len, 64), true);
1242 WARN_ON_ONCE(1);
1243 return -EINVAL;
1244 }
1245 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
1246 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
1247 } else
1248 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
1249
1250 if (skb->ip_summed == CHECKSUM_PARTIAL) {
1251 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
1252 gso.csum_start = skb_checksum_start_offset(skb);
1253 gso.csum_offset = skb->csum_offset;
1254 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
1255 gso.flags = VIRTIO_NET_HDR_F_DATA_VALID;
1256 } /* else everything is zero */
1257
1258 if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
1259 sizeof(gso))))
1260 return -EFAULT;
1261 total += tun->vnet_hdr_sz;
1262 }
1263
1264 len = min_t(int, skb->len, len);
1265
1266 skb_copy_datagram_const_iovec(skb, 0, iv, total, len);
1267 total += skb->len;
1268
1269 tun->dev->stats.tx_packets++;
1270 tun->dev->stats.tx_bytes += len;
1271
1272 return total;
1273}
1274
1275static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
1276 struct kiocb *iocb, const struct iovec *iv,
1277 ssize_t len, int noblock)
1278{
1279 DECLARE_WAITQUEUE(wait, current);
1280 struct sk_buff *skb;
1281 ssize_t ret = 0;
1282
1283 tun_debug(KERN_INFO, tun, "tun_do_read\n");
1284
1285 if (unlikely(!noblock))
1286 add_wait_queue(&tfile->wq.wait, &wait);
1287 while (len) {
1288 current->state = TASK_INTERRUPTIBLE;
1289
1290 /* Read frames from the queue */
1291 if (!(skb = skb_dequeue(&tfile->socket.sk->sk_receive_queue))) {
1292 if (noblock) {
1293 ret = -EAGAIN;
1294 break;
1295 }
1296 if (signal_pending(current)) {
1297 ret = -ERESTARTSYS;
1298 break;
1299 }
1300 if (tun->dev->reg_state != NETREG_REGISTERED) {
1301 ret = -EIO;
1302 break;
1303 }
1304
1305 /* Nothing to read, let's sleep */
1306 schedule();
1307 continue;
1308 }
1309
1310 ret = tun_put_user(tun, tfile, skb, iv, len);
1311 kfree_skb(skb);
1312 break;
1313 }
1314
1315 current->state = TASK_RUNNING;
1316 if (unlikely(!noblock))
1317 remove_wait_queue(&tfile->wq.wait, &wait);
1318
1319 return ret;
1320}
1321
1322static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
1323 unsigned long count, loff_t pos)
1324{
1325 struct file *file = iocb->ki_filp;
1326 struct tun_file *tfile = file->private_data;
1327 struct tun_struct *tun = __tun_get(tfile);
1328 ssize_t len, ret;
1329
1330 if (!tun)
1331 return -EBADFD;
1332 len = iov_length(iv, count);
1333 if (len < 0) {
1334 ret = -EINVAL;
1335 goto out;
1336 }
1337
1338 ret = tun_do_read(tun, tfile, iocb, iv, len,
1339 file->f_flags & O_NONBLOCK);
1340 ret = min_t(ssize_t, ret, len);
1341out:
1342 tun_put(tun);
1343 return ret;
1344}
1345
1346static void tun_free_netdev(struct net_device *dev)
1347{
1348 struct tun_struct *tun = netdev_priv(dev);
1349
1350 tun_flow_uninit(tun);
1351 free_netdev(dev);
1352}
1353
1354static void tun_setup(struct net_device *dev)
1355{
1356 struct tun_struct *tun = netdev_priv(dev);
1357
1358 tun->owner = INVALID_UID;
1359 tun->group = INVALID_GID;
1360
1361 dev->ethtool_ops = &tun_ethtool_ops;
1362 dev->destructor = tun_free_netdev;
1363}
1364
1365/* Trivial set of netlink ops to allow deleting tun or tap
1366 * device with netlink.
1367 */
1368static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
1369{
1370 return -EINVAL;
1371}
1372
1373static struct rtnl_link_ops tun_link_ops __read_mostly = {
1374 .kind = DRV_NAME,
1375 .priv_size = sizeof(struct tun_struct),
1376 .setup = tun_setup,
1377 .validate = tun_validate,
1378};
1379
1380static void tun_sock_write_space(struct sock *sk)
1381{
1382 struct tun_file *tfile;
1383 wait_queue_head_t *wqueue;
1384
1385 if (!sock_writeable(sk))
1386 return;
1387
1388 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
1389 return;
1390
1391 wqueue = sk_sleep(sk);
1392 if (wqueue && waitqueue_active(wqueue))
1393 wake_up_interruptible_sync_poll(wqueue, POLLOUT |
1394 POLLWRNORM | POLLWRBAND);
1395
1396 tfile = container_of(sk, struct tun_file, sk);
1397 kill_fasync(&tfile->fasync, SIGIO, POLL_OUT);
1398}
1399
1400static int tun_sendmsg(struct kiocb *iocb, struct socket *sock,
1401 struct msghdr *m, size_t total_len)
1402{
1403 int ret;
1404 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1405 struct tun_struct *tun = __tun_get(tfile);
1406
1407 if (!tun)
1408 return -EBADFD;
1409 ret = tun_get_user(tun, tfile, m->msg_control, m->msg_iov, total_len,
1410 m->msg_iovlen, m->msg_flags & MSG_DONTWAIT);
1411 tun_put(tun);
1412 return ret;
1413}
1414
1415
1416static int tun_recvmsg(struct kiocb *iocb, struct socket *sock,
1417 struct msghdr *m, size_t total_len,
1418 int flags)
1419{
1420 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1421 struct tun_struct *tun = __tun_get(tfile);
1422 int ret;
1423
1424 if (!tun)
1425 return -EBADFD;
1426
1427 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))
1428 return -EINVAL;
1429 ret = tun_do_read(tun, tfile, iocb, m->msg_iov, total_len,
1430 flags & MSG_DONTWAIT);
1431 if (ret > total_len) {
1432 m->msg_flags |= MSG_TRUNC;
1433 ret = flags & MSG_TRUNC ? ret : total_len;
1434 }
1435 tun_put(tun);
1436 return ret;
1437}
1438
1439static int tun_release(struct socket *sock)
1440{
1441 if (sock->sk)
1442 sock_put(sock->sk);
1443 return 0;
1444}
1445
1446/* Ops structure to mimic raw sockets with tun */
1447static const struct proto_ops tun_socket_ops = {
1448 .sendmsg = tun_sendmsg,
1449 .recvmsg = tun_recvmsg,
1450 .release = tun_release,
1451};
1452
1453static struct proto tun_proto = {
1454 .name = "tun",
1455 .owner = THIS_MODULE,
1456 .obj_size = sizeof(struct tun_file),
1457};
1458
1459static int tun_flags(struct tun_struct *tun)
1460{
1461 int flags = 0;
1462
1463 if (tun->flags & TUN_TUN_DEV)
1464 flags |= IFF_TUN;
1465 else
1466 flags |= IFF_TAP;
1467
1468 if (tun->flags & TUN_NO_PI)
1469 flags |= IFF_NO_PI;
1470
1471 /* This flag has no real effect. We track the value for backwards
1472 * compatibility.
1473 */
1474 if (tun->flags & TUN_ONE_QUEUE)
1475 flags |= IFF_ONE_QUEUE;
1476
1477 if (tun->flags & TUN_VNET_HDR)
1478 flags |= IFF_VNET_HDR;
1479
1480 if (tun->flags & TUN_TAP_MQ)
1481 flags |= IFF_MULTI_QUEUE;
1482
1483 return flags;
1484}
1485
1486static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
1487 char *buf)
1488{
1489 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1490 return sprintf(buf, "0x%x\n", tun_flags(tun));
1491}
1492
1493static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
1494 char *buf)
1495{
1496 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1497 return uid_valid(tun->owner)?
1498 sprintf(buf, "%u\n",
1499 from_kuid_munged(current_user_ns(), tun->owner)):
1500 sprintf(buf, "-1\n");
1501}
1502
1503static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
1504 char *buf)
1505{
1506 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1507 return gid_valid(tun->group) ?
1508 sprintf(buf, "%u\n",
1509 from_kgid_munged(current_user_ns(), tun->group)):
1510 sprintf(buf, "-1\n");
1511}
1512
1513static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
1514static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
1515static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
1516
1517static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
1518{
1519 struct tun_struct *tun;
1520 struct tun_file *tfile = file->private_data;
1521 struct net_device *dev;
1522 int err;
1523
1524 dev = __dev_get_by_name(net, ifr->ifr_name);
1525 if (dev) {
1526 if (ifr->ifr_flags & IFF_TUN_EXCL)
1527 return -EBUSY;
1528 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
1529 tun = netdev_priv(dev);
1530 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
1531 tun = netdev_priv(dev);
1532 else
1533 return -EINVAL;
1534
1535 if (tun_not_capable(tun))
1536 return -EPERM;
1537 err = security_tun_dev_attach(tfile->socket.sk);
1538 if (err < 0)
1539 return err;
1540
1541 err = tun_attach(tun, file);
1542 if (err < 0)
1543 return err;
1544 }
1545 else {
1546 char *name;
1547 unsigned long flags = 0;
1548
1549 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1550 return -EPERM;
1551 err = security_tun_dev_create();
1552 if (err < 0)
1553 return err;
1554
1555 /* Set dev type */
1556 if (ifr->ifr_flags & IFF_TUN) {
1557 /* TUN device */
1558 flags |= TUN_TUN_DEV;
1559 name = "tun%d";
1560 } else if (ifr->ifr_flags & IFF_TAP) {
1561 /* TAP device */
1562 flags |= TUN_TAP_DEV;
1563 name = "tap%d";
1564 } else
1565 return -EINVAL;
1566
1567 if (*ifr->ifr_name)
1568 name = ifr->ifr_name;
1569
1570 dev = alloc_netdev_mqs(sizeof(struct tun_struct), name,
1571 tun_setup,
1572 MAX_TAP_QUEUES, MAX_TAP_QUEUES);
1573 if (!dev)
1574 return -ENOMEM;
1575
1576 dev_net_set(dev, net);
1577 dev->rtnl_link_ops = &tun_link_ops;
1578
1579 tun = netdev_priv(dev);
1580 tun->dev = dev;
1581 tun->flags = flags;
1582 tun->txflt.count = 0;
1583 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
1584
1585 tun->filter_attached = false;
1586 tun->sndbuf = tfile->socket.sk->sk_sndbuf;
1587
1588 spin_lock_init(&tun->lock);
1589
1590 security_tun_dev_post_create(&tfile->sk);
1591
1592 tun_net_init(dev);
1593
1594 if (tun_flow_init(tun))
1595 goto err_free_dev;
1596
1597 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
1598 TUN_USER_FEATURES;
1599 dev->features = dev->hw_features;
1600
1601 err = tun_attach(tun, file);
1602 if (err < 0)
1603 goto err_free_dev;
1604
1605 err = register_netdevice(tun->dev);
1606 if (err < 0)
1607 goto err_free_dev;
1608
1609 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
1610 device_create_file(&tun->dev->dev, &dev_attr_owner) ||
1611 device_create_file(&tun->dev->dev, &dev_attr_group))
1612 pr_err("Failed to create tun sysfs files\n");
1613
1614 netif_carrier_on(tun->dev);
1615 }
1616
1617 tun_debug(KERN_INFO, tun, "tun_set_iff\n");
1618
1619 if (ifr->ifr_flags & IFF_NO_PI)
1620 tun->flags |= TUN_NO_PI;
1621 else
1622 tun->flags &= ~TUN_NO_PI;
1623
1624 /* This flag has no real effect. We track the value for backwards
1625 * compatibility.
1626 */
1627 if (ifr->ifr_flags & IFF_ONE_QUEUE)
1628 tun->flags |= TUN_ONE_QUEUE;
1629 else
1630 tun->flags &= ~TUN_ONE_QUEUE;
1631
1632 if (ifr->ifr_flags & IFF_VNET_HDR)
1633 tun->flags |= TUN_VNET_HDR;
1634 else
1635 tun->flags &= ~TUN_VNET_HDR;
1636
1637 if (ifr->ifr_flags & IFF_MULTI_QUEUE)
1638 tun->flags |= TUN_TAP_MQ;
1639 else
1640 tun->flags &= ~TUN_TAP_MQ;
1641
1642 /* Make sure persistent devices do not get stuck in
1643 * xoff state.
1644 */
1645 if (netif_running(tun->dev))
1646 netif_tx_wake_all_queues(tun->dev);
1647
1648 strcpy(ifr->ifr_name, tun->dev->name);
1649 return 0;
1650
1651 err_free_dev:
1652 free_netdev(dev);
1653 return err;
1654}
1655
1656static void tun_get_iff(struct net *net, struct tun_struct *tun,
1657 struct ifreq *ifr)
1658{
1659 tun_debug(KERN_INFO, tun, "tun_get_iff\n");
1660
1661 strcpy(ifr->ifr_name, tun->dev->name);
1662
1663 ifr->ifr_flags = tun_flags(tun);
1664
1665}
1666
1667/* This is like a cut-down ethtool ops, except done via tun fd so no
1668 * privs required. */
1669static int set_offload(struct tun_struct *tun, unsigned long arg)
1670{
1671 netdev_features_t features = 0;
1672
1673 if (arg & TUN_F_CSUM) {
1674 features |= NETIF_F_HW_CSUM;
1675 arg &= ~TUN_F_CSUM;
1676
1677 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1678 if (arg & TUN_F_TSO_ECN) {
1679 features |= NETIF_F_TSO_ECN;
1680 arg &= ~TUN_F_TSO_ECN;
1681 }
1682 if (arg & TUN_F_TSO4)
1683 features |= NETIF_F_TSO;
1684 if (arg & TUN_F_TSO6)
1685 features |= NETIF_F_TSO6;
1686 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1687 }
1688
1689 if (arg & TUN_F_UFO) {
1690 features |= NETIF_F_UFO;
1691 arg &= ~TUN_F_UFO;
1692 }
1693 }
1694
1695 /* This gives the user a way to test for new features in future by
1696 * trying to set them. */
1697 if (arg)
1698 return -EINVAL;
1699
1700 tun->set_features = features;
1701 netdev_update_features(tun->dev);
1702
1703 return 0;
1704}
1705
1706static void tun_detach_filter(struct tun_struct *tun, int n)
1707{
1708 int i;
1709 struct tun_file *tfile;
1710
1711 for (i = 0; i < n; i++) {
1712 tfile = rcu_dereference_protected(tun->tfiles[i],
1713 lockdep_rtnl_is_held());
1714 sk_detach_filter(tfile->socket.sk);
1715 }
1716
1717 tun->filter_attached = false;
1718}
1719
1720static int tun_attach_filter(struct tun_struct *tun)
1721{
1722 int i, ret = 0;
1723 struct tun_file *tfile;
1724
1725 for (i = 0; i < tun->numqueues; i++) {
1726 tfile = rcu_dereference_protected(tun->tfiles[i],
1727 lockdep_rtnl_is_held());
1728 ret = sk_attach_filter(&tun->fprog, tfile->socket.sk);
1729 if (ret) {
1730 tun_detach_filter(tun, i);
1731 return ret;
1732 }
1733 }
1734
1735 tun->filter_attached = true;
1736 return ret;
1737}
1738
1739static void tun_set_sndbuf(struct tun_struct *tun)
1740{
1741 struct tun_file *tfile;
1742 int i;
1743
1744 for (i = 0; i < tun->numqueues; i++) {
1745 tfile = rcu_dereference_protected(tun->tfiles[i],
1746 lockdep_rtnl_is_held());
1747 tfile->socket.sk->sk_sndbuf = tun->sndbuf;
1748 }
1749}
1750
1751static int tun_set_queue(struct file *file, struct ifreq *ifr)
1752{
1753 struct tun_file *tfile = file->private_data;
1754 struct tun_struct *tun;
1755 struct net_device *dev;
1756 int ret = 0;
1757
1758 rtnl_lock();
1759
1760 if (ifr->ifr_flags & IFF_ATTACH_QUEUE) {
1761 dev = __dev_get_by_name(tfile->net, ifr->ifr_name);
1762 if (!dev) {
1763 ret = -EINVAL;
1764 goto unlock;
1765 }
1766
1767 tun = netdev_priv(dev);
1768 if (dev->netdev_ops != &tap_netdev_ops &&
1769 dev->netdev_ops != &tun_netdev_ops)
1770 ret = -EINVAL;
1771 else if (tun_not_capable(tun))
1772 ret = -EPERM;
1773 else
1774 ret = tun_attach(tun, file);
1775 } else if (ifr->ifr_flags & IFF_DETACH_QUEUE)
1776 __tun_detach(tfile, false);
1777 else
1778 ret = -EINVAL;
1779
1780unlock:
1781 rtnl_unlock();
1782 return ret;
1783}
1784
1785static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
1786 unsigned long arg, int ifreq_len)
1787{
1788 struct tun_file *tfile = file->private_data;
1789 struct tun_struct *tun;
1790 void __user* argp = (void __user*)arg;
1791 struct ifreq ifr;
1792 kuid_t owner;
1793 kgid_t group;
1794 int sndbuf;
1795 int vnet_hdr_sz;
1796 int ret;
1797
1798 if (cmd == TUNSETIFF || cmd == TUNSETQUEUE || _IOC_TYPE(cmd) == 0x89) {
1799 if (copy_from_user(&ifr, argp, ifreq_len))
1800 return -EFAULT;
1801 } else {
1802 memset(&ifr, 0, sizeof(ifr));
1803 }
1804 if (cmd == TUNGETFEATURES) {
1805 /* Currently this just means: "what IFF flags are valid?".
1806 * This is needed because we never checked for invalid flags on
1807 * TUNSETIFF. */
1808 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
1809 IFF_VNET_HDR | IFF_MULTI_QUEUE,
1810 (unsigned int __user*)argp);
1811 } else if (cmd == TUNSETQUEUE)
1812 return tun_set_queue(file, &ifr);
1813
1814 ret = 0;
1815 rtnl_lock();
1816
1817 tun = __tun_get(tfile);
1818 if (cmd == TUNSETIFF && !tun) {
1819 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1820
1821 ret = tun_set_iff(tfile->net, file, &ifr);
1822
1823 if (ret)
1824 goto unlock;
1825
1826 if (copy_to_user(argp, &ifr, ifreq_len))
1827 ret = -EFAULT;
1828 goto unlock;
1829 }
1830
1831 ret = -EBADFD;
1832 if (!tun)
1833 goto unlock;
1834
1835 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %u\n", cmd);
1836
1837 ret = 0;
1838 switch (cmd) {
1839 case TUNGETIFF:
1840 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1841
1842 if (copy_to_user(argp, &ifr, ifreq_len))
1843 ret = -EFAULT;
1844 break;
1845
1846 case TUNSETNOCSUM:
1847 /* Disable/Enable checksum */
1848
1849 /* [unimplemented] */
1850 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n",
1851 arg ? "disabled" : "enabled");
1852 break;
1853
1854 case TUNSETPERSIST:
1855 /* Disable/Enable persist mode. Keep an extra reference to the
1856 * module to prevent the module being unprobed.
1857 */
1858 if (arg) {
1859 tun->flags |= TUN_PERSIST;
1860 __module_get(THIS_MODULE);
1861 } else {
1862 tun->flags &= ~TUN_PERSIST;
1863 module_put(THIS_MODULE);
1864 }
1865
1866 tun_debug(KERN_INFO, tun, "persist %s\n",
1867 arg ? "enabled" : "disabled");
1868 break;
1869
1870 case TUNSETOWNER:
1871 /* Set owner of the device */
1872 owner = make_kuid(current_user_ns(), arg);
1873 if (!uid_valid(owner)) {
1874 ret = -EINVAL;
1875 break;
1876 }
1877 tun->owner = owner;
1878 tun_debug(KERN_INFO, tun, "owner set to %u\n",
1879 from_kuid(&init_user_ns, tun->owner));
1880 break;
1881
1882 case TUNSETGROUP:
1883 /* Set group of the device */
1884 group = make_kgid(current_user_ns(), arg);
1885 if (!gid_valid(group)) {
1886 ret = -EINVAL;
1887 break;
1888 }
1889 tun->group = group;
1890 tun_debug(KERN_INFO, tun, "group set to %u\n",
1891 from_kgid(&init_user_ns, tun->group));
1892 break;
1893
1894 case TUNSETLINK:
1895 /* Only allow setting the type when the interface is down */
1896 if (tun->dev->flags & IFF_UP) {
1897 tun_debug(KERN_INFO, tun,
1898 "Linktype set failed because interface is up\n");
1899 ret = -EBUSY;
1900 } else {
1901 tun->dev->type = (int) arg;
1902 tun_debug(KERN_INFO, tun, "linktype set to %d\n",
1903 tun->dev->type);
1904 ret = 0;
1905 }
1906 break;
1907
1908#ifdef TUN_DEBUG
1909 case TUNSETDEBUG:
1910 tun->debug = arg;
1911 break;
1912#endif
1913 case TUNSETOFFLOAD:
1914 ret = set_offload(tun, arg);
1915 break;
1916
1917 case TUNSETTXFILTER:
1918 /* Can be set only for TAPs */
1919 ret = -EINVAL;
1920 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1921 break;
1922 ret = update_filter(&tun->txflt, (void __user *)arg);
1923 break;
1924
1925 case SIOCGIFHWADDR:
1926 /* Get hw address */
1927 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
1928 ifr.ifr_hwaddr.sa_family = tun->dev->type;
1929 if (copy_to_user(argp, &ifr, ifreq_len))
1930 ret = -EFAULT;
1931 break;
1932
1933 case SIOCSIFHWADDR:
1934 /* Set hw address */
1935 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
1936 ifr.ifr_hwaddr.sa_data);
1937
1938 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
1939 break;
1940
1941 case TUNGETSNDBUF:
1942 sndbuf = tfile->socket.sk->sk_sndbuf;
1943 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
1944 ret = -EFAULT;
1945 break;
1946
1947 case TUNSETSNDBUF:
1948 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
1949 ret = -EFAULT;
1950 break;
1951 }
1952
1953 tun->sndbuf = sndbuf;
1954 tun_set_sndbuf(tun);
1955 break;
1956
1957 case TUNGETVNETHDRSZ:
1958 vnet_hdr_sz = tun->vnet_hdr_sz;
1959 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
1960 ret = -EFAULT;
1961 break;
1962
1963 case TUNSETVNETHDRSZ:
1964 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
1965 ret = -EFAULT;
1966 break;
1967 }
1968 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
1969 ret = -EINVAL;
1970 break;
1971 }
1972
1973 tun->vnet_hdr_sz = vnet_hdr_sz;
1974 break;
1975
1976 case TUNATTACHFILTER:
1977 /* Can be set only for TAPs */
1978 ret = -EINVAL;
1979 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1980 break;
1981 ret = -EFAULT;
1982 if (copy_from_user(&tun->fprog, argp, sizeof(tun->fprog)))
1983 break;
1984
1985 ret = tun_attach_filter(tun);
1986 break;
1987
1988 case TUNDETACHFILTER:
1989 /* Can be set only for TAPs */
1990 ret = -EINVAL;
1991 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1992 break;
1993 ret = 0;
1994 tun_detach_filter(tun, tun->numqueues);
1995 break;
1996
1997 default:
1998 ret = -EINVAL;
1999 break;
2000 }
2001
2002unlock:
2003 rtnl_unlock();
2004 if (tun)
2005 tun_put(tun);
2006 return ret;
2007}
2008
2009static long tun_chr_ioctl(struct file *file,
2010 unsigned int cmd, unsigned long arg)
2011{
2012 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
2013}
2014
2015#ifdef CONFIG_COMPAT
2016static long tun_chr_compat_ioctl(struct file *file,
2017 unsigned int cmd, unsigned long arg)
2018{
2019 switch (cmd) {
2020 case TUNSETIFF:
2021 case TUNGETIFF:
2022 case TUNSETTXFILTER:
2023 case TUNGETSNDBUF:
2024 case TUNSETSNDBUF:
2025 case SIOCGIFHWADDR:
2026 case SIOCSIFHWADDR:
2027 arg = (unsigned long)compat_ptr(arg);
2028 break;
2029 default:
2030 arg = (compat_ulong_t)arg;
2031 break;
2032 }
2033
2034 /*
2035 * compat_ifreq is shorter than ifreq, so we must not access beyond
2036 * the end of that structure. All fields that are used in this
2037 * driver are compatible though, we don't need to convert the
2038 * contents.
2039 */
2040 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
2041}
2042#endif /* CONFIG_COMPAT */
2043
2044static int tun_chr_fasync(int fd, struct file *file, int on)
2045{
2046 struct tun_file *tfile = file->private_data;
2047 int ret;
2048
2049 if ((ret = fasync_helper(fd, file, on, &tfile->fasync)) < 0)
2050 goto out;
2051
2052 if (on) {
2053 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
2054 if (ret)
2055 goto out;
2056 tfile->flags |= TUN_FASYNC;
2057 } else
2058 tfile->flags &= ~TUN_FASYNC;
2059 ret = 0;
2060out:
2061 return ret;
2062}
2063
2064static int tun_chr_open(struct inode *inode, struct file * file)
2065{
2066 struct tun_file *tfile;
2067
2068 DBG1(KERN_INFO, "tunX: tun_chr_open\n");
2069
2070 tfile = (struct tun_file *)sk_alloc(&init_net, AF_UNSPEC, GFP_KERNEL,
2071 &tun_proto);
2072 if (!tfile)
2073 return -ENOMEM;
2074 rcu_assign_pointer(tfile->tun, NULL);
2075 tfile->net = get_net(current->nsproxy->net_ns);
2076 tfile->flags = 0;
2077
2078 rcu_assign_pointer(tfile->socket.wq, &tfile->wq);
2079 init_waitqueue_head(&tfile->wq.wait);
2080
2081 tfile->socket.file = file;
2082 tfile->socket.ops = &tun_socket_ops;
2083
2084 sock_init_data(&tfile->socket, &tfile->sk);
2085 sk_change_net(&tfile->sk, tfile->net);
2086
2087 tfile->sk.sk_write_space = tun_sock_write_space;
2088 tfile->sk.sk_sndbuf = INT_MAX;
2089
2090 file->private_data = tfile;
2091 set_bit(SOCK_EXTERNALLY_ALLOCATED, &tfile->socket.flags);
2092
2093 return 0;
2094}
2095
2096static int tun_chr_close(struct inode *inode, struct file *file)
2097{
2098 struct tun_file *tfile = file->private_data;
2099 struct net *net = tfile->net;
2100
2101 tun_detach(tfile, true);
2102 put_net(net);
2103
2104 return 0;
2105}
2106
2107static const struct file_operations tun_fops = {
2108 .owner = THIS_MODULE,
2109 .llseek = no_llseek,
2110 .read = do_sync_read,
2111 .aio_read = tun_chr_aio_read,
2112 .write = do_sync_write,
2113 .aio_write = tun_chr_aio_write,
2114 .poll = tun_chr_poll,
2115 .unlocked_ioctl = tun_chr_ioctl,
2116#ifdef CONFIG_COMPAT
2117 .compat_ioctl = tun_chr_compat_ioctl,
2118#endif
2119 .open = tun_chr_open,
2120 .release = tun_chr_close,
2121 .fasync = tun_chr_fasync
2122};
2123
2124static struct miscdevice tun_miscdev = {
2125 .minor = TUN_MINOR,
2126 .name = "tun",
2127 .nodename = "net/tun",
2128 .fops = &tun_fops,
2129};
2130
2131/* ethtool interface */
2132
2133static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
2134{
2135 cmd->supported = 0;
2136 cmd->advertising = 0;
2137 ethtool_cmd_speed_set(cmd, SPEED_10);
2138 cmd->duplex = DUPLEX_FULL;
2139 cmd->port = PORT_TP;
2140 cmd->phy_address = 0;
2141 cmd->transceiver = XCVR_INTERNAL;
2142 cmd->autoneg = AUTONEG_DISABLE;
2143 cmd->maxtxpkt = 0;
2144 cmd->maxrxpkt = 0;
2145 return 0;
2146}
2147
2148static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
2149{
2150 struct tun_struct *tun = netdev_priv(dev);
2151
2152 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
2153 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
2154
2155 switch (tun->flags & TUN_TYPE_MASK) {
2156 case TUN_TUN_DEV:
2157 strlcpy(info->bus_info, "tun", sizeof(info->bus_info));
2158 break;
2159 case TUN_TAP_DEV:
2160 strlcpy(info->bus_info, "tap", sizeof(info->bus_info));
2161 break;
2162 }
2163}
2164
2165static u32 tun_get_msglevel(struct net_device *dev)
2166{
2167#ifdef TUN_DEBUG
2168 struct tun_struct *tun = netdev_priv(dev);
2169 return tun->debug;
2170#else
2171 return -EOPNOTSUPP;
2172#endif
2173}
2174
2175static void tun_set_msglevel(struct net_device *dev, u32 value)
2176{
2177#ifdef TUN_DEBUG
2178 struct tun_struct *tun = netdev_priv(dev);
2179 tun->debug = value;
2180#endif
2181}
2182
2183static const struct ethtool_ops tun_ethtool_ops = {
2184 .get_settings = tun_get_settings,
2185 .get_drvinfo = tun_get_drvinfo,
2186 .get_msglevel = tun_get_msglevel,
2187 .set_msglevel = tun_set_msglevel,
2188 .get_link = ethtool_op_get_link,
2189};
2190
2191
2192static int __init tun_init(void)
2193{
2194 int ret = 0;
2195
2196 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
2197 pr_info("%s\n", DRV_COPYRIGHT);
2198
2199 ret = rtnl_link_register(&tun_link_ops);
2200 if (ret) {
2201 pr_err("Can't register link_ops\n");
2202 goto err_linkops;
2203 }
2204
2205 ret = misc_register(&tun_miscdev);
2206 if (ret) {
2207 pr_err("Can't register misc device %d\n", TUN_MINOR);
2208 goto err_misc;
2209 }
2210 return 0;
2211err_misc:
2212 rtnl_link_unregister(&tun_link_ops);
2213err_linkops:
2214 return ret;
2215}
2216
2217static void tun_cleanup(void)
2218{
2219 misc_deregister(&tun_miscdev);
2220 rtnl_link_unregister(&tun_link_ops);
2221}
2222
2223/* Get an underlying socket object from tun file. Returns error unless file is
2224 * attached to a device. The returned object works like a packet socket, it
2225 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
2226 * holding a reference to the file for as long as the socket is in use. */
2227struct socket *tun_get_socket(struct file *file)
2228{
2229 struct tun_file *tfile;
2230 if (file->f_op != &tun_fops)
2231 return ERR_PTR(-EINVAL);
2232 tfile = file->private_data;
2233 if (!tfile)
2234 return ERR_PTR(-EBADFD);
2235 return &tfile->socket;
2236}
2237EXPORT_SYMBOL_GPL(tun_get_socket);
2238
2239module_init(tun_init);
2240module_exit(tun_cleanup);
2241MODULE_DESCRIPTION(DRV_DESCRIPTION);
2242MODULE_AUTHOR(DRV_COPYRIGHT);
2243MODULE_LICENSE("GPL");
2244MODULE_ALIAS_MISCDEV(TUN_MINOR);
2245MODULE_ALIAS("devname:net/tun");
kernel source for telekom puls (alcatel/mediatek)