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tuntap: forbid changing mq flag for persistent device
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / net / tun.c
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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/* DEFAULT_MAX_NUM_RSS_QUEUES were choosed to let the rx/tx queues allocated for
113 * the netdevice to be fit in one page. So we can make sure the success of
114 * memory allocation. TODO: increase the limit. */
115#define MAX_TAP_QUEUES DEFAULT_MAX_NUM_RSS_QUEUES
116#define MAX_TAP_FLOWS 4096
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 struct list_head next;
142 struct tun_struct *detached;
143};
144
145struct 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 */
161struct 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 void *security;
189 u32 flow_count;
190};
191
192static inline u32 tun_hashfn(u32 rxhash)
193{
194 return rxhash & 0x3ff;
195}
196
197static struct tun_flow_entry *tun_flow_find(struct hlist_head *head, u32 rxhash)
198{
199 struct tun_flow_entry *e;
200
201 hlist_for_each_entry_rcu(e, head, hash_link) {
202 if (e->rxhash == rxhash)
203 return e;
204 }
205 return NULL;
206}
207
208static struct tun_flow_entry *tun_flow_create(struct tun_struct *tun,
209 struct hlist_head *head,
210 u32 rxhash, u16 queue_index)
211{
212 struct tun_flow_entry *e = kmalloc(sizeof(*e), GFP_ATOMIC);
213
214 if (e) {
215 tun_debug(KERN_INFO, tun, "create flow: hash %u index %u\n",
216 rxhash, queue_index);
217 e->updated = jiffies;
218 e->rxhash = rxhash;
219 e->queue_index = queue_index;
220 e->tun = tun;
221 hlist_add_head_rcu(&e->hash_link, head);
222 ++tun->flow_count;
223 }
224 return e;
225}
226
227static void tun_flow_delete(struct tun_struct *tun, struct tun_flow_entry *e)
228{
229 tun_debug(KERN_INFO, tun, "delete flow: hash %u index %u\n",
230 e->rxhash, e->queue_index);
231 hlist_del_rcu(&e->hash_link);
232 kfree_rcu(e, rcu);
233 --tun->flow_count;
234}
235
236static void tun_flow_flush(struct tun_struct *tun)
237{
238 int i;
239
240 spin_lock_bh(&tun->lock);
241 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
242 struct tun_flow_entry *e;
243 struct hlist_node *n;
244
245 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link)
246 tun_flow_delete(tun, e);
247 }
248 spin_unlock_bh(&tun->lock);
249}
250
251static void tun_flow_delete_by_queue(struct tun_struct *tun, u16 queue_index)
252{
253 int i;
254
255 spin_lock_bh(&tun->lock);
256 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
257 struct tun_flow_entry *e;
258 struct hlist_node *n;
259
260 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
261 if (e->queue_index == queue_index)
262 tun_flow_delete(tun, e);
263 }
264 }
265 spin_unlock_bh(&tun->lock);
266}
267
268static void tun_flow_cleanup(unsigned long data)
269{
270 struct tun_struct *tun = (struct tun_struct *)data;
271 unsigned long delay = tun->ageing_time;
272 unsigned long next_timer = jiffies + delay;
273 unsigned long count = 0;
274 int i;
275
276 tun_debug(KERN_INFO, tun, "tun_flow_cleanup\n");
277
278 spin_lock_bh(&tun->lock);
279 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
280 struct tun_flow_entry *e;
281 struct hlist_node *n;
282
283 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
284 unsigned long this_timer;
285 count++;
286 this_timer = e->updated + delay;
287 if (time_before_eq(this_timer, jiffies))
288 tun_flow_delete(tun, e);
289 else if (time_before(this_timer, next_timer))
290 next_timer = this_timer;
291 }
292 }
293
294 if (count)
295 mod_timer(&tun->flow_gc_timer, round_jiffies_up(next_timer));
296 spin_unlock_bh(&tun->lock);
297}
298
299static void tun_flow_update(struct tun_struct *tun, u32 rxhash,
300 struct tun_file *tfile)
301{
302 struct hlist_head *head;
303 struct tun_flow_entry *e;
304 unsigned long delay = tun->ageing_time;
305 u16 queue_index = tfile->queue_index;
306
307 if (!rxhash)
308 return;
309 else
310 head = &tun->flows[tun_hashfn(rxhash)];
311
312 rcu_read_lock();
313
314 /* We may get a very small possibility of OOO during switching, not
315 * worth to optimize.*/
316 if (tun->numqueues == 1 || tfile->detached)
317 goto unlock;
318
319 e = tun_flow_find(head, rxhash);
320 if (likely(e)) {
321 /* TODO: keep queueing to old queue until it's empty? */
322 e->queue_index = queue_index;
323 e->updated = jiffies;
324 } else {
325 spin_lock_bh(&tun->lock);
326 if (!tun_flow_find(head, rxhash) &&
327 tun->flow_count < MAX_TAP_FLOWS)
328 tun_flow_create(tun, head, rxhash, queue_index);
329
330 if (!timer_pending(&tun->flow_gc_timer))
331 mod_timer(&tun->flow_gc_timer,
332 round_jiffies_up(jiffies + delay));
333 spin_unlock_bh(&tun->lock);
334 }
335
336unlock:
337 rcu_read_unlock();
338}
339
340/* We try to identify a flow through its rxhash first. The reason that
341 * we do not check rxq no. is becuase some cards(e.g 82599), chooses
342 * the rxq based on the txq where the last packet of the flow comes. As
343 * the userspace application move between processors, we may get a
344 * different rxq no. here. If we could not get rxhash, then we would
345 * hope the rxq no. may help here.
346 */
347static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb)
348{
349 struct tun_struct *tun = netdev_priv(dev);
350 struct tun_flow_entry *e;
351 u32 txq = 0;
352 u32 numqueues = 0;
353
354 rcu_read_lock();
355 numqueues = tun->numqueues;
356
357 txq = skb_get_rxhash(skb);
358 if (txq) {
359 e = tun_flow_find(&tun->flows[tun_hashfn(txq)], txq);
360 if (e)
361 txq = e->queue_index;
362 else
363 /* use multiply and shift instead of expensive divide */
364 txq = ((u64)txq * numqueues) >> 32;
365 } else if (likely(skb_rx_queue_recorded(skb))) {
366 txq = skb_get_rx_queue(skb);
367 while (unlikely(txq >= numqueues))
368 txq -= numqueues;
369 }
370
371 rcu_read_unlock();
372 return txq;
373}
374
375static inline bool tun_not_capable(struct tun_struct *tun)
376{
377 const struct cred *cred = current_cred();
378 struct net *net = dev_net(tun->dev);
379
380 return ((uid_valid(tun->owner) && !uid_eq(cred->euid, tun->owner)) ||
381 (gid_valid(tun->group) && !in_egroup_p(tun->group))) &&
382 !ns_capable(net->user_ns, CAP_NET_ADMIN);
383}
384
385static void tun_set_real_num_queues(struct tun_struct *tun)
386{
387 netif_set_real_num_tx_queues(tun->dev, tun->numqueues);
388 netif_set_real_num_rx_queues(tun->dev, tun->numqueues);
389}
390
391static void tun_disable_queue(struct tun_struct *tun, struct tun_file *tfile)
392{
393 tfile->detached = tun;
394 list_add_tail(&tfile->next, &tun->disabled);
395 ++tun->numdisabled;
396}
397
398static struct tun_struct *tun_enable_queue(struct tun_file *tfile)
399{
400 struct tun_struct *tun = tfile->detached;
401
402 tfile->detached = NULL;
403 list_del_init(&tfile->next);
404 --tun->numdisabled;
405 return tun;
406}
407
408static void __tun_detach(struct tun_file *tfile, bool clean)
409{
410 struct tun_file *ntfile;
411 struct tun_struct *tun;
412
413 tun = rtnl_dereference(tfile->tun);
414
415 if (tun && !tfile->detached) {
416 u16 index = tfile->queue_index;
417 BUG_ON(index >= tun->numqueues);
418
419 rcu_assign_pointer(tun->tfiles[index],
420 tun->tfiles[tun->numqueues - 1]);
421 ntfile = rtnl_dereference(tun->tfiles[index]);
422 ntfile->queue_index = index;
423
424 --tun->numqueues;
425 if (clean) {
426 rcu_assign_pointer(tfile->tun, NULL);
427 sock_put(&tfile->sk);
428 } else
429 tun_disable_queue(tun, tfile);
430
431 synchronize_net();
432 tun_flow_delete_by_queue(tun, tun->numqueues + 1);
433 /* Drop read queue */
434 skb_queue_purge(&tfile->sk.sk_receive_queue);
435 tun_set_real_num_queues(tun);
436 } else if (tfile->detached && clean) {
437 tun = tun_enable_queue(tfile);
438 sock_put(&tfile->sk);
439 }
440
441 if (clean) {
442 if (tun && tun->numqueues == 0 && tun->numdisabled == 0) {
443 netif_carrier_off(tun->dev);
444
445 if (!(tun->flags & TUN_PERSIST) &&
446 tun->dev->reg_state == NETREG_REGISTERED)
447 unregister_netdevice(tun->dev);
448 }
449
450 BUG_ON(!test_bit(SOCK_EXTERNALLY_ALLOCATED,
451 &tfile->socket.flags));
452 sk_release_kernel(&tfile->sk);
453 }
454}
455
456static void tun_detach(struct tun_file *tfile, bool clean)
457{
458 rtnl_lock();
459 __tun_detach(tfile, clean);
460 rtnl_unlock();
461}
462
463static void tun_detach_all(struct net_device *dev)
464{
465 struct tun_struct *tun = netdev_priv(dev);
466 struct tun_file *tfile, *tmp;
467 int i, n = tun->numqueues;
468
469 for (i = 0; i < n; i++) {
470 tfile = rtnl_dereference(tun->tfiles[i]);
471 BUG_ON(!tfile);
472 wake_up_all(&tfile->wq.wait);
473 rcu_assign_pointer(tfile->tun, NULL);
474 --tun->numqueues;
475 }
476 list_for_each_entry(tfile, &tun->disabled, next) {
477 wake_up_all(&tfile->wq.wait);
478 rcu_assign_pointer(tfile->tun, NULL);
479 }
480 BUG_ON(tun->numqueues != 0);
481
482 synchronize_net();
483 for (i = 0; i < n; i++) {
484 tfile = rtnl_dereference(tun->tfiles[i]);
485 /* Drop read queue */
486 skb_queue_purge(&tfile->sk.sk_receive_queue);
487 sock_put(&tfile->sk);
488 }
489 list_for_each_entry_safe(tfile, tmp, &tun->disabled, next) {
490 tun_enable_queue(tfile);
491 skb_queue_purge(&tfile->sk.sk_receive_queue);
492 sock_put(&tfile->sk);
493 }
494 BUG_ON(tun->numdisabled != 0);
495
496 if (tun->flags & TUN_PERSIST)
497 module_put(THIS_MODULE);
498}
499
500static int tun_attach(struct tun_struct *tun, struct file *file)
501{
502 struct tun_file *tfile = file->private_data;
503 int err;
504
505 err = security_tun_dev_attach(tfile->socket.sk, tun->security);
506 if (err < 0)
507 goto out;
508
509 err = -EINVAL;
510 if (rtnl_dereference(tfile->tun) && !tfile->detached)
511 goto out;
512
513 err = -EBUSY;
514 if (!(tun->flags & TUN_TAP_MQ) && tun->numqueues == 1)
515 goto out;
516
517 err = -E2BIG;
518 if (!tfile->detached &&
519 tun->numqueues + tun->numdisabled == MAX_TAP_QUEUES)
520 goto out;
521
522 err = 0;
523
524 /* Re-attach the filter to presist device */
525 if (tun->filter_attached == true) {
526 err = sk_attach_filter(&tun->fprog, tfile->socket.sk);
527 if (!err)
528 goto out;
529 }
530 tfile->queue_index = tun->numqueues;
531 rcu_assign_pointer(tfile->tun, tun);
532 rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile);
533 tun->numqueues++;
534
535 if (tfile->detached)
536 tun_enable_queue(tfile);
537 else
538 sock_hold(&tfile->sk);
539
540 tun_set_real_num_queues(tun);
541
542 /* device is allowed to go away first, so no need to hold extra
543 * refcnt.
544 */
545
546out:
547 return err;
548}
549
550static struct tun_struct *__tun_get(struct tun_file *tfile)
551{
552 struct tun_struct *tun;
553
554 rcu_read_lock();
555 tun = rcu_dereference(tfile->tun);
556 if (tun)
557 dev_hold(tun->dev);
558 rcu_read_unlock();
559
560 return tun;
561}
562
563static struct tun_struct *tun_get(struct file *file)
564{
565 return __tun_get(file->private_data);
566}
567
568static void tun_put(struct tun_struct *tun)
569{
570 dev_put(tun->dev);
571}
572
573/* TAP filtering */
574static void addr_hash_set(u32 *mask, const u8 *addr)
575{
576 int n = ether_crc(ETH_ALEN, addr) >> 26;
577 mask[n >> 5] |= (1 << (n & 31));
578}
579
580static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
581{
582 int n = ether_crc(ETH_ALEN, addr) >> 26;
583 return mask[n >> 5] & (1 << (n & 31));
584}
585
586static int update_filter(struct tap_filter *filter, void __user *arg)
587{
588 struct { u8 u[ETH_ALEN]; } *addr;
589 struct tun_filter uf;
590 int err, alen, n, nexact;
591
592 if (copy_from_user(&uf, arg, sizeof(uf)))
593 return -EFAULT;
594
595 if (!uf.count) {
596 /* Disabled */
597 filter->count = 0;
598 return 0;
599 }
600
601 alen = ETH_ALEN * uf.count;
602 addr = kmalloc(alen, GFP_KERNEL);
603 if (!addr)
604 return -ENOMEM;
605
606 if (copy_from_user(addr, arg + sizeof(uf), alen)) {
607 err = -EFAULT;
608 goto done;
609 }
610
611 /* The filter is updated without holding any locks. Which is
612 * perfectly safe. We disable it first and in the worst
613 * case we'll accept a few undesired packets. */
614 filter->count = 0;
615 wmb();
616
617 /* Use first set of addresses as an exact filter */
618 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
619 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
620
621 nexact = n;
622
623 /* Remaining multicast addresses are hashed,
624 * unicast will leave the filter disabled. */
625 memset(filter->mask, 0, sizeof(filter->mask));
626 for (; n < uf.count; n++) {
627 if (!is_multicast_ether_addr(addr[n].u)) {
628 err = 0; /* no filter */
629 goto done;
630 }
631 addr_hash_set(filter->mask, addr[n].u);
632 }
633
634 /* For ALLMULTI just set the mask to all ones.
635 * This overrides the mask populated above. */
636 if ((uf.flags & TUN_FLT_ALLMULTI))
637 memset(filter->mask, ~0, sizeof(filter->mask));
638
639 /* Now enable the filter */
640 wmb();
641 filter->count = nexact;
642
643 /* Return the number of exact filters */
644 err = nexact;
645
646done:
647 kfree(addr);
648 return err;
649}
650
651/* Returns: 0 - drop, !=0 - accept */
652static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
653{
654 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
655 * at this point. */
656 struct ethhdr *eh = (struct ethhdr *) skb->data;
657 int i;
658
659 /* Exact match */
660 for (i = 0; i < filter->count; i++)
661 if (ether_addr_equal(eh->h_dest, filter->addr[i]))
662 return 1;
663
664 /* Inexact match (multicast only) */
665 if (is_multicast_ether_addr(eh->h_dest))
666 return addr_hash_test(filter->mask, eh->h_dest);
667
668 return 0;
669}
670
671/*
672 * Checks whether the packet is accepted or not.
673 * Returns: 0 - drop, !=0 - accept
674 */
675static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
676{
677 if (!filter->count)
678 return 1;
679
680 return run_filter(filter, skb);
681}
682
683/* Network device part of the driver */
684
685static const struct ethtool_ops tun_ethtool_ops;
686
687/* Net device detach from fd. */
688static void tun_net_uninit(struct net_device *dev)
689{
690 tun_detach_all(dev);
691}
692
693/* Net device open. */
694static int tun_net_open(struct net_device *dev)
695{
696 netif_tx_start_all_queues(dev);
697 return 0;
698}
699
700/* Net device close. */
701static int tun_net_close(struct net_device *dev)
702{
703 netif_tx_stop_all_queues(dev);
704 return 0;
705}
706
707/* Net device start xmit */
708static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
709{
710 struct tun_struct *tun = netdev_priv(dev);
711 int txq = skb->queue_mapping;
712 struct tun_file *tfile;
713
714 rcu_read_lock();
715 tfile = rcu_dereference(tun->tfiles[txq]);
716
717 /* Drop packet if interface is not attached */
718 if (txq >= tun->numqueues)
719 goto drop;
720
721 tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len);
722
723 BUG_ON(!tfile);
724
725 /* Drop if the filter does not like it.
726 * This is a noop if the filter is disabled.
727 * Filter can be enabled only for the TAP devices. */
728 if (!check_filter(&tun->txflt, skb))
729 goto drop;
730
731 if (tfile->socket.sk->sk_filter &&
732 sk_filter(tfile->socket.sk, skb))
733 goto drop;
734
735 /* Limit the number of packets queued by dividing txq length with the
736 * number of queues.
737 */
738 if (skb_queue_len(&tfile->socket.sk->sk_receive_queue)
739 >= dev->tx_queue_len / tun->numqueues)
740 goto drop;
741
742 /* Orphan the skb - required as we might hang on to it
743 * for indefinite time. */
744 if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
745 goto drop;
746 skb_orphan(skb);
747
748 nf_reset(skb);
749
750 /* Enqueue packet */
751 skb_queue_tail(&tfile->socket.sk->sk_receive_queue, skb);
752
753 /* Notify and wake up reader process */
754 if (tfile->flags & TUN_FASYNC)
755 kill_fasync(&tfile->fasync, SIGIO, POLL_IN);
756 wake_up_interruptible_poll(&tfile->wq.wait, POLLIN |
757 POLLRDNORM | POLLRDBAND);
758
759 rcu_read_unlock();
760 return NETDEV_TX_OK;
761
762drop:
763 dev->stats.tx_dropped++;
764 skb_tx_error(skb);
765 kfree_skb(skb);
766 rcu_read_unlock();
767 return NETDEV_TX_OK;
768}
769
770static void tun_net_mclist(struct net_device *dev)
771{
772 /*
773 * This callback is supposed to deal with mc filter in
774 * _rx_ path and has nothing to do with the _tx_ path.
775 * In rx path we always accept everything userspace gives us.
776 */
777}
778
779#define MIN_MTU 68
780#define MAX_MTU 65535
781
782static int
783tun_net_change_mtu(struct net_device *dev, int new_mtu)
784{
785 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
786 return -EINVAL;
787 dev->mtu = new_mtu;
788 return 0;
789}
790
791static netdev_features_t tun_net_fix_features(struct net_device *dev,
792 netdev_features_t features)
793{
794 struct tun_struct *tun = netdev_priv(dev);
795
796 return (features & tun->set_features) | (features & ~TUN_USER_FEATURES);
797}
798#ifdef CONFIG_NET_POLL_CONTROLLER
799static void tun_poll_controller(struct net_device *dev)
800{
801 /*
802 * Tun only receives frames when:
803 * 1) the char device endpoint gets data from user space
804 * 2) the tun socket gets a sendmsg call from user space
805 * Since both of those are syncronous operations, we are guaranteed
806 * never to have pending data when we poll for it
807 * so theres nothing to do here but return.
808 * We need this though so netpoll recognizes us as an interface that
809 * supports polling, which enables bridge devices in virt setups to
810 * still use netconsole
811 */
812 return;
813}
814#endif
815static const struct net_device_ops tun_netdev_ops = {
816 .ndo_uninit = tun_net_uninit,
817 .ndo_open = tun_net_open,
818 .ndo_stop = tun_net_close,
819 .ndo_start_xmit = tun_net_xmit,
820 .ndo_change_mtu = tun_net_change_mtu,
821 .ndo_fix_features = tun_net_fix_features,
822 .ndo_select_queue = tun_select_queue,
823#ifdef CONFIG_NET_POLL_CONTROLLER
824 .ndo_poll_controller = tun_poll_controller,
825#endif
826};
827
828static const struct net_device_ops tap_netdev_ops = {
829 .ndo_uninit = tun_net_uninit,
830 .ndo_open = tun_net_open,
831 .ndo_stop = tun_net_close,
832 .ndo_start_xmit = tun_net_xmit,
833 .ndo_change_mtu = tun_net_change_mtu,
834 .ndo_fix_features = tun_net_fix_features,
835 .ndo_set_rx_mode = tun_net_mclist,
836 .ndo_set_mac_address = eth_mac_addr,
837 .ndo_validate_addr = eth_validate_addr,
838 .ndo_select_queue = tun_select_queue,
839#ifdef CONFIG_NET_POLL_CONTROLLER
840 .ndo_poll_controller = tun_poll_controller,
841#endif
842};
843
844static int tun_flow_init(struct tun_struct *tun)
845{
846 int i;
847
848 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++)
849 INIT_HLIST_HEAD(&tun->flows[i]);
850
851 tun->ageing_time = TUN_FLOW_EXPIRE;
852 setup_timer(&tun->flow_gc_timer, tun_flow_cleanup, (unsigned long)tun);
853 mod_timer(&tun->flow_gc_timer,
854 round_jiffies_up(jiffies + tun->ageing_time));
855
856 return 0;
857}
858
859static void tun_flow_uninit(struct tun_struct *tun)
860{
861 del_timer_sync(&tun->flow_gc_timer);
862 tun_flow_flush(tun);
863}
864
865/* Initialize net device. */
866static void tun_net_init(struct net_device *dev)
867{
868 struct tun_struct *tun = netdev_priv(dev);
869
870 switch (tun->flags & TUN_TYPE_MASK) {
871 case TUN_TUN_DEV:
872 dev->netdev_ops = &tun_netdev_ops;
873
874 /* Point-to-Point TUN Device */
875 dev->hard_header_len = 0;
876 dev->addr_len = 0;
877 dev->mtu = 1500;
878
879 /* Zero header length */
880 dev->type = ARPHRD_NONE;
881 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
882 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
883 break;
884
885 case TUN_TAP_DEV:
886 dev->netdev_ops = &tap_netdev_ops;
887 /* Ethernet TAP Device */
888 ether_setup(dev);
889 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
890 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
891
892 eth_hw_addr_random(dev);
893
894 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
895 break;
896 }
897}
898
899/* Character device part */
900
901/* Poll */
902static unsigned int tun_chr_poll(struct file *file, poll_table *wait)
903{
904 struct tun_file *tfile = file->private_data;
905 struct tun_struct *tun = __tun_get(tfile);
906 struct sock *sk;
907 unsigned int mask = 0;
908
909 if (!tun)
910 return POLLERR;
911
912 sk = tfile->socket.sk;
913
914 tun_debug(KERN_INFO, tun, "tun_chr_poll\n");
915
916 poll_wait(file, &tfile->wq.wait, wait);
917
918 if (!skb_queue_empty(&sk->sk_receive_queue))
919 mask |= POLLIN | POLLRDNORM;
920
921 if (sock_writeable(sk) ||
922 (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
923 sock_writeable(sk)))
924 mask |= POLLOUT | POLLWRNORM;
925
926 if (tun->dev->reg_state != NETREG_REGISTERED)
927 mask = POLLERR;
928
929 tun_put(tun);
930 return mask;
931}
932
933/* prepad is the amount to reserve at front. len is length after that.
934 * linear is a hint as to how much to copy (usually headers). */
935static struct sk_buff *tun_alloc_skb(struct tun_file *tfile,
936 size_t prepad, size_t len,
937 size_t linear, int noblock)
938{
939 struct sock *sk = tfile->socket.sk;
940 struct sk_buff *skb;
941 int err;
942
943 /* Under a page? Don't bother with paged skb. */
944 if (prepad + len < PAGE_SIZE || !linear)
945 linear = len;
946
947 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
948 &err);
949 if (!skb)
950 return ERR_PTR(err);
951
952 skb_reserve(skb, prepad);
953 skb_put(skb, linear);
954 skb->data_len = len - linear;
955 skb->len += len - linear;
956
957 return skb;
958}
959
960/* set skb frags from iovec, this can move to core network code for reuse */
961static int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *from,
962 int offset, size_t count)
963{
964 int len = iov_length(from, count) - offset;
965 int copy = skb_headlen(skb);
966 int size, offset1 = 0;
967 int i = 0;
968
969 /* Skip over from offset */
970 while (count && (offset >= from->iov_len)) {
971 offset -= from->iov_len;
972 ++from;
973 --count;
974 }
975
976 /* copy up to skb headlen */
977 while (count && (copy > 0)) {
978 size = min_t(unsigned int, copy, from->iov_len - offset);
979 if (copy_from_user(skb->data + offset1, from->iov_base + offset,
980 size))
981 return -EFAULT;
982 if (copy > size) {
983 ++from;
984 --count;
985 offset = 0;
986 } else
987 offset += size;
988 copy -= size;
989 offset1 += size;
990 }
991
992 if (len == offset1)
993 return 0;
994
995 while (count--) {
996 struct page *page[MAX_SKB_FRAGS];
997 int num_pages;
998 unsigned long base;
999 unsigned long truesize;
1000
1001 len = from->iov_len - offset;
1002 if (!len) {
1003 offset = 0;
1004 ++from;
1005 continue;
1006 }
1007 base = (unsigned long)from->iov_base + offset;
1008 size = ((base & ~PAGE_MASK) + len + ~PAGE_MASK) >> PAGE_SHIFT;
1009 if (i + size > MAX_SKB_FRAGS)
1010 return -EMSGSIZE;
1011 num_pages = get_user_pages_fast(base, size, 0, &page[i]);
1012 if (num_pages != size) {
1013 for (i = 0; i < num_pages; i++)
1014 put_page(page[i]);
1015 return -EFAULT;
1016 }
1017 truesize = size * PAGE_SIZE;
1018 skb->data_len += len;
1019 skb->len += len;
1020 skb->truesize += truesize;
1021 atomic_add(truesize, &skb->sk->sk_wmem_alloc);
1022 while (len) {
1023 int off = base & ~PAGE_MASK;
1024 int size = min_t(int, len, PAGE_SIZE - off);
1025 __skb_fill_page_desc(skb, i, page[i], off, size);
1026 skb_shinfo(skb)->nr_frags++;
1027 /* increase sk_wmem_alloc */
1028 base += size;
1029 len -= size;
1030 i++;
1031 }
1032 offset = 0;
1033 ++from;
1034 }
1035 return 0;
1036}
1037
1038/* Get packet from user space buffer */
1039static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
1040 void *msg_control, const struct iovec *iv,
1041 size_t total_len, size_t count, int noblock)
1042{
1043 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
1044 struct sk_buff *skb;
1045 size_t len = total_len, align = NET_SKB_PAD;
1046 struct virtio_net_hdr gso = { 0 };
1047 int offset = 0;
1048 int copylen;
1049 bool zerocopy = false;
1050 int err;
1051 u32 rxhash;
1052
1053 if (!(tun->flags & TUN_NO_PI)) {
1054 if ((len -= sizeof(pi)) > total_len)
1055 return -EINVAL;
1056
1057 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
1058 return -EFAULT;
1059 offset += sizeof(pi);
1060 }
1061
1062 if (tun->flags & TUN_VNET_HDR) {
1063 if ((len -= tun->vnet_hdr_sz) > total_len)
1064 return -EINVAL;
1065
1066 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
1067 return -EFAULT;
1068
1069 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
1070 gso.csum_start + gso.csum_offset + 2 > gso.hdr_len)
1071 gso.hdr_len = gso.csum_start + gso.csum_offset + 2;
1072
1073 if (gso.hdr_len > len)
1074 return -EINVAL;
1075 offset += tun->vnet_hdr_sz;
1076 }
1077
1078 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
1079 align += NET_IP_ALIGN;
1080 if (unlikely(len < ETH_HLEN ||
1081 (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
1082 return -EINVAL;
1083 }
1084
1085 if (msg_control)
1086 zerocopy = true;
1087
1088 if (zerocopy) {
1089 /* Userspace may produce vectors with count greater than
1090 * MAX_SKB_FRAGS, so we need to linearize parts of the skb
1091 * to let the rest of data to be fit in the frags.
1092 */
1093 if (count > MAX_SKB_FRAGS) {
1094 copylen = iov_length(iv, count - MAX_SKB_FRAGS);
1095 if (copylen < offset)
1096 copylen = 0;
1097 else
1098 copylen -= offset;
1099 } else
1100 copylen = 0;
1101 /* There are 256 bytes to be copied in skb, so there is enough
1102 * room for skb expand head in case it is used.
1103 * The rest of the buffer is mapped from userspace.
1104 */
1105 if (copylen < gso.hdr_len)
1106 copylen = gso.hdr_len;
1107 if (!copylen)
1108 copylen = GOODCOPY_LEN;
1109 } else
1110 copylen = len;
1111
1112 skb = tun_alloc_skb(tfile, align, copylen, gso.hdr_len, noblock);
1113 if (IS_ERR(skb)) {
1114 if (PTR_ERR(skb) != -EAGAIN)
1115 tun->dev->stats.rx_dropped++;
1116 return PTR_ERR(skb);
1117 }
1118
1119 if (zerocopy)
1120 err = zerocopy_sg_from_iovec(skb, iv, offset, count);
1121 else
1122 err = skb_copy_datagram_from_iovec(skb, 0, iv, offset, len);
1123
1124 if (err) {
1125 tun->dev->stats.rx_dropped++;
1126 kfree_skb(skb);
1127 return -EFAULT;
1128 }
1129
1130 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
1131 if (!skb_partial_csum_set(skb, gso.csum_start,
1132 gso.csum_offset)) {
1133 tun->dev->stats.rx_frame_errors++;
1134 kfree_skb(skb);
1135 return -EINVAL;
1136 }
1137 }
1138
1139 switch (tun->flags & TUN_TYPE_MASK) {
1140 case TUN_TUN_DEV:
1141 if (tun->flags & TUN_NO_PI) {
1142 switch (skb->data[0] & 0xf0) {
1143 case 0x40:
1144 pi.proto = htons(ETH_P_IP);
1145 break;
1146 case 0x60:
1147 pi.proto = htons(ETH_P_IPV6);
1148 break;
1149 default:
1150 tun->dev->stats.rx_dropped++;
1151 kfree_skb(skb);
1152 return -EINVAL;
1153 }
1154 }
1155
1156 skb_reset_mac_header(skb);
1157 skb->protocol = pi.proto;
1158 skb->dev = tun->dev;
1159 break;
1160 case TUN_TAP_DEV:
1161 skb->protocol = eth_type_trans(skb, tun->dev);
1162 break;
1163 }
1164
1165 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
1166 pr_debug("GSO!\n");
1167 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
1168 case VIRTIO_NET_HDR_GSO_TCPV4:
1169 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
1170 break;
1171 case VIRTIO_NET_HDR_GSO_TCPV6:
1172 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
1173 break;
1174 case VIRTIO_NET_HDR_GSO_UDP:
1175 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
1176 break;
1177 default:
1178 tun->dev->stats.rx_frame_errors++;
1179 kfree_skb(skb);
1180 return -EINVAL;
1181 }
1182
1183 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
1184 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
1185
1186 skb_shinfo(skb)->gso_size = gso.gso_size;
1187 if (skb_shinfo(skb)->gso_size == 0) {
1188 tun->dev->stats.rx_frame_errors++;
1189 kfree_skb(skb);
1190 return -EINVAL;
1191 }
1192
1193 /* Header must be checked, and gso_segs computed. */
1194 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
1195 skb_shinfo(skb)->gso_segs = 0;
1196 }
1197
1198 /* copy skb_ubuf_info for callback when skb has no error */
1199 if (zerocopy) {
1200 skb_shinfo(skb)->destructor_arg = msg_control;
1201 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1202 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
1203 }
1204
1205 skb_reset_network_header(skb);
1206 skb_probe_transport_header(skb, 0);
1207
1208 rxhash = skb_get_rxhash(skb);
1209 netif_rx_ni(skb);
1210
1211 tun->dev->stats.rx_packets++;
1212 tun->dev->stats.rx_bytes += len;
1213
1214 tun_flow_update(tun, rxhash, tfile);
1215 return total_len;
1216}
1217
1218static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
1219 unsigned long count, loff_t pos)
1220{
1221 struct file *file = iocb->ki_filp;
1222 struct tun_struct *tun = tun_get(file);
1223 struct tun_file *tfile = file->private_data;
1224 ssize_t result;
1225
1226 if (!tun)
1227 return -EBADFD;
1228
1229 tun_debug(KERN_INFO, tun, "tun_chr_write %ld\n", count);
1230
1231 result = tun_get_user(tun, tfile, NULL, iv, iov_length(iv, count),
1232 count, file->f_flags & O_NONBLOCK);
1233
1234 tun_put(tun);
1235 return result;
1236}
1237
1238/* Put packet to the user space buffer */
1239static ssize_t tun_put_user(struct tun_struct *tun,
1240 struct tun_file *tfile,
1241 struct sk_buff *skb,
1242 const struct iovec *iv, int len)
1243{
1244 struct tun_pi pi = { 0, skb->protocol };
1245 ssize_t total = 0;
1246
1247 if (!(tun->flags & TUN_NO_PI)) {
1248 if ((len -= sizeof(pi)) < 0)
1249 return -EINVAL;
1250
1251 if (len < skb->len) {
1252 /* Packet will be striped */
1253 pi.flags |= TUN_PKT_STRIP;
1254 }
1255
1256 if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi)))
1257 return -EFAULT;
1258 total += sizeof(pi);
1259 }
1260
1261 if (tun->flags & TUN_VNET_HDR) {
1262 struct virtio_net_hdr gso = { 0 }; /* no info leak */
1263 if ((len -= tun->vnet_hdr_sz) < 0)
1264 return -EINVAL;
1265
1266 if (skb_is_gso(skb)) {
1267 struct skb_shared_info *sinfo = skb_shinfo(skb);
1268
1269 /* This is a hint as to how much should be linear. */
1270 gso.hdr_len = skb_headlen(skb);
1271 gso.gso_size = sinfo->gso_size;
1272 if (sinfo->gso_type & SKB_GSO_TCPV4)
1273 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
1274 else if (sinfo->gso_type & SKB_GSO_TCPV6)
1275 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
1276 else if (sinfo->gso_type & SKB_GSO_UDP)
1277 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
1278 else {
1279 pr_err("unexpected GSO type: "
1280 "0x%x, gso_size %d, hdr_len %d\n",
1281 sinfo->gso_type, gso.gso_size,
1282 gso.hdr_len);
1283 print_hex_dump(KERN_ERR, "tun: ",
1284 DUMP_PREFIX_NONE,
1285 16, 1, skb->head,
1286 min((int)gso.hdr_len, 64), true);
1287 WARN_ON_ONCE(1);
1288 return -EINVAL;
1289 }
1290 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
1291 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
1292 } else
1293 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
1294
1295 if (skb->ip_summed == CHECKSUM_PARTIAL) {
1296 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
1297 gso.csum_start = skb_checksum_start_offset(skb);
1298 gso.csum_offset = skb->csum_offset;
1299 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
1300 gso.flags = VIRTIO_NET_HDR_F_DATA_VALID;
1301 } /* else everything is zero */
1302
1303 if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
1304 sizeof(gso))))
1305 return -EFAULT;
1306 total += tun->vnet_hdr_sz;
1307 }
1308
1309 len = min_t(int, skb->len, len);
1310
1311 skb_copy_datagram_const_iovec(skb, 0, iv, total, len);
1312 total += skb->len;
1313
1314 tun->dev->stats.tx_packets++;
1315 tun->dev->stats.tx_bytes += len;
1316
1317 return total;
1318}
1319
1320static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
1321 struct kiocb *iocb, const struct iovec *iv,
1322 ssize_t len, int noblock)
1323{
1324 DECLARE_WAITQUEUE(wait, current);
1325 struct sk_buff *skb;
1326 ssize_t ret = 0;
1327
1328 tun_debug(KERN_INFO, tun, "tun_do_read\n");
1329
1330 if (unlikely(!noblock))
1331 add_wait_queue(&tfile->wq.wait, &wait);
1332 while (len) {
1333 current->state = TASK_INTERRUPTIBLE;
1334
1335 /* Read frames from the queue */
1336 if (!(skb = skb_dequeue(&tfile->socket.sk->sk_receive_queue))) {
1337 if (noblock) {
1338 ret = -EAGAIN;
1339 break;
1340 }
1341 if (signal_pending(current)) {
1342 ret = -ERESTARTSYS;
1343 break;
1344 }
1345 if (tun->dev->reg_state != NETREG_REGISTERED) {
1346 ret = -EIO;
1347 break;
1348 }
1349
1350 /* Nothing to read, let's sleep */
1351 schedule();
1352 continue;
1353 }
1354
1355 ret = tun_put_user(tun, tfile, skb, iv, len);
1356 kfree_skb(skb);
1357 break;
1358 }
1359
1360 current->state = TASK_RUNNING;
1361 if (unlikely(!noblock))
1362 remove_wait_queue(&tfile->wq.wait, &wait);
1363
1364 return ret;
1365}
1366
1367static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
1368 unsigned long count, loff_t pos)
1369{
1370 struct file *file = iocb->ki_filp;
1371 struct tun_file *tfile = file->private_data;
1372 struct tun_struct *tun = __tun_get(tfile);
1373 ssize_t len, ret;
1374
1375 if (!tun)
1376 return -EBADFD;
1377 len = iov_length(iv, count);
1378 if (len < 0) {
1379 ret = -EINVAL;
1380 goto out;
1381 }
1382
1383 ret = tun_do_read(tun, tfile, iocb, iv, len,
1384 file->f_flags & O_NONBLOCK);
1385 ret = min_t(ssize_t, ret, len);
1386out:
1387 tun_put(tun);
1388 return ret;
1389}
1390
1391static void tun_free_netdev(struct net_device *dev)
1392{
1393 struct tun_struct *tun = netdev_priv(dev);
1394
1395 BUG_ON(!(list_empty(&tun->disabled)));
1396 tun_flow_uninit(tun);
1397 security_tun_dev_free_security(tun->security);
1398 free_netdev(dev);
1399}
1400
1401static void tun_setup(struct net_device *dev)
1402{
1403 struct tun_struct *tun = netdev_priv(dev);
1404
1405 tun->owner = INVALID_UID;
1406 tun->group = INVALID_GID;
1407
1408 dev->ethtool_ops = &tun_ethtool_ops;
1409 dev->destructor = tun_free_netdev;
1410}
1411
1412/* Trivial set of netlink ops to allow deleting tun or tap
1413 * device with netlink.
1414 */
1415static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
1416{
1417 return -EINVAL;
1418}
1419
1420static struct rtnl_link_ops tun_link_ops __read_mostly = {
1421 .kind = DRV_NAME,
1422 .priv_size = sizeof(struct tun_struct),
1423 .setup = tun_setup,
1424 .validate = tun_validate,
1425};
1426
1427static void tun_sock_write_space(struct sock *sk)
1428{
1429 struct tun_file *tfile;
1430 wait_queue_head_t *wqueue;
1431
1432 if (!sock_writeable(sk))
1433 return;
1434
1435 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
1436 return;
1437
1438 wqueue = sk_sleep(sk);
1439 if (wqueue && waitqueue_active(wqueue))
1440 wake_up_interruptible_sync_poll(wqueue, POLLOUT |
1441 POLLWRNORM | POLLWRBAND);
1442
1443 tfile = container_of(sk, struct tun_file, sk);
1444 kill_fasync(&tfile->fasync, SIGIO, POLL_OUT);
1445}
1446
1447static int tun_sendmsg(struct kiocb *iocb, struct socket *sock,
1448 struct msghdr *m, size_t total_len)
1449{
1450 int ret;
1451 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1452 struct tun_struct *tun = __tun_get(tfile);
1453
1454 if (!tun)
1455 return -EBADFD;
1456 ret = tun_get_user(tun, tfile, m->msg_control, m->msg_iov, total_len,
1457 m->msg_iovlen, m->msg_flags & MSG_DONTWAIT);
1458 tun_put(tun);
1459 return ret;
1460}
1461
1462
1463static int tun_recvmsg(struct kiocb *iocb, struct socket *sock,
1464 struct msghdr *m, size_t total_len,
1465 int flags)
1466{
1467 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1468 struct tun_struct *tun = __tun_get(tfile);
1469 int ret;
1470
1471 if (!tun)
1472 return -EBADFD;
1473
1474 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC)) {
1475 ret = -EINVAL;
1476 goto out;
1477 }
1478 ret = tun_do_read(tun, tfile, iocb, m->msg_iov, total_len,
1479 flags & MSG_DONTWAIT);
1480 if (ret > total_len) {
1481 m->msg_flags |= MSG_TRUNC;
1482 ret = flags & MSG_TRUNC ? ret : total_len;
1483 }
1484out:
1485 tun_put(tun);
1486 return ret;
1487}
1488
1489static int tun_release(struct socket *sock)
1490{
1491 if (sock->sk)
1492 sock_put(sock->sk);
1493 return 0;
1494}
1495
1496/* Ops structure to mimic raw sockets with tun */
1497static const struct proto_ops tun_socket_ops = {
1498 .sendmsg = tun_sendmsg,
1499 .recvmsg = tun_recvmsg,
1500 .release = tun_release,
1501};
1502
1503static struct proto tun_proto = {
1504 .name = "tun",
1505 .owner = THIS_MODULE,
1506 .obj_size = sizeof(struct tun_file),
1507};
1508
1509static int tun_flags(struct tun_struct *tun)
1510{
1511 int flags = 0;
1512
1513 if (tun->flags & TUN_TUN_DEV)
1514 flags |= IFF_TUN;
1515 else
1516 flags |= IFF_TAP;
1517
1518 if (tun->flags & TUN_NO_PI)
1519 flags |= IFF_NO_PI;
1520
1521 /* This flag has no real effect. We track the value for backwards
1522 * compatibility.
1523 */
1524 if (tun->flags & TUN_ONE_QUEUE)
1525 flags |= IFF_ONE_QUEUE;
1526
1527 if (tun->flags & TUN_VNET_HDR)
1528 flags |= IFF_VNET_HDR;
1529
1530 if (tun->flags & TUN_TAP_MQ)
1531 flags |= IFF_MULTI_QUEUE;
1532
1533 return flags;
1534}
1535
1536static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
1537 char *buf)
1538{
1539 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1540 return sprintf(buf, "0x%x\n", tun_flags(tun));
1541}
1542
1543static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
1544 char *buf)
1545{
1546 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1547 return uid_valid(tun->owner)?
1548 sprintf(buf, "%u\n",
1549 from_kuid_munged(current_user_ns(), tun->owner)):
1550 sprintf(buf, "-1\n");
1551}
1552
1553static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
1554 char *buf)
1555{
1556 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1557 return gid_valid(tun->group) ?
1558 sprintf(buf, "%u\n",
1559 from_kgid_munged(current_user_ns(), tun->group)):
1560 sprintf(buf, "-1\n");
1561}
1562
1563static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
1564static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
1565static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
1566
1567static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
1568{
1569 struct tun_struct *tun;
1570 struct tun_file *tfile = file->private_data;
1571 struct net_device *dev;
1572 int err;
1573
1574 if (tfile->detached)
1575 return -EINVAL;
1576
1577 dev = __dev_get_by_name(net, ifr->ifr_name);
1578 if (dev) {
1579 if (ifr->ifr_flags & IFF_TUN_EXCL)
1580 return -EBUSY;
1581 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
1582 tun = netdev_priv(dev);
1583 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
1584 tun = netdev_priv(dev);
1585 else
1586 return -EINVAL;
1587
1588 if (!!(ifr->ifr_flags & IFF_MULTI_QUEUE) !=
1589 !!(tun->flags & TUN_TAP_MQ))
1590 return -EINVAL;
1591
1592 if (tun_not_capable(tun))
1593 return -EPERM;
1594 err = security_tun_dev_open(tun->security);
1595 if (err < 0)
1596 return err;
1597
1598 err = tun_attach(tun, file);
1599 if (err < 0)
1600 return err;
1601
1602 if (tun->flags & TUN_TAP_MQ &&
1603 (tun->numqueues + tun->numdisabled > 1)) {
1604 /* One or more queue has already been attached, no need
1605 * to initialize the device again.
1606 */
1607 return 0;
1608 }
1609 }
1610 else {
1611 char *name;
1612 unsigned long flags = 0;
1613 int queues = ifr->ifr_flags & IFF_MULTI_QUEUE ?
1614 MAX_TAP_QUEUES : 1;
1615
1616 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1617 return -EPERM;
1618 err = security_tun_dev_create();
1619 if (err < 0)
1620 return err;
1621
1622 /* Set dev type */
1623 if (ifr->ifr_flags & IFF_TUN) {
1624 /* TUN device */
1625 flags |= TUN_TUN_DEV;
1626 name = "tun%d";
1627 } else if (ifr->ifr_flags & IFF_TAP) {
1628 /* TAP device */
1629 flags |= TUN_TAP_DEV;
1630 name = "tap%d";
1631 } else
1632 return -EINVAL;
1633
1634 if (*ifr->ifr_name)
1635 name = ifr->ifr_name;
1636
1637 dev = alloc_netdev_mqs(sizeof(struct tun_struct), name,
1638 tun_setup, queues, queues);
1639
1640 if (!dev)
1641 return -ENOMEM;
1642
1643 dev_net_set(dev, net);
1644 dev->rtnl_link_ops = &tun_link_ops;
1645
1646 tun = netdev_priv(dev);
1647 tun->dev = dev;
1648 tun->flags = flags;
1649 tun->txflt.count = 0;
1650 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
1651
1652 tun->filter_attached = false;
1653 tun->sndbuf = tfile->socket.sk->sk_sndbuf;
1654
1655 spin_lock_init(&tun->lock);
1656
1657 err = security_tun_dev_alloc_security(&tun->security);
1658 if (err < 0)
1659 goto err_free_dev;
1660
1661 tun_net_init(dev);
1662
1663 err = tun_flow_init(tun);
1664 if (err < 0)
1665 goto err_free_dev;
1666
1667 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
1668 TUN_USER_FEATURES;
1669 dev->features = dev->hw_features;
1670 dev->vlan_features = dev->features;
1671
1672 INIT_LIST_HEAD(&tun->disabled);
1673 err = tun_attach(tun, file);
1674 if (err < 0)
1675 goto err_free_dev;
1676
1677 err = register_netdevice(tun->dev);
1678 if (err < 0)
1679 goto err_free_dev;
1680
1681 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
1682 device_create_file(&tun->dev->dev, &dev_attr_owner) ||
1683 device_create_file(&tun->dev->dev, &dev_attr_group))
1684 pr_err("Failed to create tun sysfs files\n");
1685 }
1686
1687 netif_carrier_on(tun->dev);
1688
1689 tun_debug(KERN_INFO, tun, "tun_set_iff\n");
1690
1691 if (ifr->ifr_flags & IFF_NO_PI)
1692 tun->flags |= TUN_NO_PI;
1693 else
1694 tun->flags &= ~TUN_NO_PI;
1695
1696 /* This flag has no real effect. We track the value for backwards
1697 * compatibility.
1698 */
1699 if (ifr->ifr_flags & IFF_ONE_QUEUE)
1700 tun->flags |= TUN_ONE_QUEUE;
1701 else
1702 tun->flags &= ~TUN_ONE_QUEUE;
1703
1704 if (ifr->ifr_flags & IFF_VNET_HDR)
1705 tun->flags |= TUN_VNET_HDR;
1706 else
1707 tun->flags &= ~TUN_VNET_HDR;
1708
1709 if (ifr->ifr_flags & IFF_MULTI_QUEUE)
1710 tun->flags |= TUN_TAP_MQ;
1711 else
1712 tun->flags &= ~TUN_TAP_MQ;
1713
1714 /* Make sure persistent devices do not get stuck in
1715 * xoff state.
1716 */
1717 if (netif_running(tun->dev))
1718 netif_tx_wake_all_queues(tun->dev);
1719
1720 strcpy(ifr->ifr_name, tun->dev->name);
1721 return 0;
1722
1723 err_free_dev:
1724 free_netdev(dev);
1725 return err;
1726}
1727
1728static void tun_get_iff(struct net *net, struct tun_struct *tun,
1729 struct ifreq *ifr)
1730{
1731 tun_debug(KERN_INFO, tun, "tun_get_iff\n");
1732
1733 strcpy(ifr->ifr_name, tun->dev->name);
1734
1735 ifr->ifr_flags = tun_flags(tun);
1736
1737}
1738
1739/* This is like a cut-down ethtool ops, except done via tun fd so no
1740 * privs required. */
1741static int set_offload(struct tun_struct *tun, unsigned long arg)
1742{
1743 netdev_features_t features = 0;
1744
1745 if (arg & TUN_F_CSUM) {
1746 features |= NETIF_F_HW_CSUM;
1747 arg &= ~TUN_F_CSUM;
1748
1749 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1750 if (arg & TUN_F_TSO_ECN) {
1751 features |= NETIF_F_TSO_ECN;
1752 arg &= ~TUN_F_TSO_ECN;
1753 }
1754 if (arg & TUN_F_TSO4)
1755 features |= NETIF_F_TSO;
1756 if (arg & TUN_F_TSO6)
1757 features |= NETIF_F_TSO6;
1758 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1759 }
1760
1761 if (arg & TUN_F_UFO) {
1762 features |= NETIF_F_UFO;
1763 arg &= ~TUN_F_UFO;
1764 }
1765 }
1766
1767 /* This gives the user a way to test for new features in future by
1768 * trying to set them. */
1769 if (arg)
1770 return -EINVAL;
1771
1772 tun->set_features = features;
1773 netdev_update_features(tun->dev);
1774
1775 return 0;
1776}
1777
1778static void tun_detach_filter(struct tun_struct *tun, int n)
1779{
1780 int i;
1781 struct tun_file *tfile;
1782
1783 for (i = 0; i < n; i++) {
1784 tfile = rtnl_dereference(tun->tfiles[i]);
1785 sk_detach_filter(tfile->socket.sk);
1786 }
1787
1788 tun->filter_attached = false;
1789}
1790
1791static int tun_attach_filter(struct tun_struct *tun)
1792{
1793 int i, ret = 0;
1794 struct tun_file *tfile;
1795
1796 for (i = 0; i < tun->numqueues; i++) {
1797 tfile = rtnl_dereference(tun->tfiles[i]);
1798 ret = sk_attach_filter(&tun->fprog, tfile->socket.sk);
1799 if (ret) {
1800 tun_detach_filter(tun, i);
1801 return ret;
1802 }
1803 }
1804
1805 tun->filter_attached = true;
1806 return ret;
1807}
1808
1809static void tun_set_sndbuf(struct tun_struct *tun)
1810{
1811 struct tun_file *tfile;
1812 int i;
1813
1814 for (i = 0; i < tun->numqueues; i++) {
1815 tfile = rtnl_dereference(tun->tfiles[i]);
1816 tfile->socket.sk->sk_sndbuf = tun->sndbuf;
1817 }
1818}
1819
1820static int tun_set_queue(struct file *file, struct ifreq *ifr)
1821{
1822 struct tun_file *tfile = file->private_data;
1823 struct tun_struct *tun;
1824 int ret = 0;
1825
1826 rtnl_lock();
1827
1828 if (ifr->ifr_flags & IFF_ATTACH_QUEUE) {
1829 tun = tfile->detached;
1830 if (!tun) {
1831 ret = -EINVAL;
1832 goto unlock;
1833 }
1834 ret = security_tun_dev_attach_queue(tun->security);
1835 if (ret < 0)
1836 goto unlock;
1837 ret = tun_attach(tun, file);
1838 } else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
1839 tun = rtnl_dereference(tfile->tun);
1840 if (!tun || !(tun->flags & TUN_TAP_MQ) || tfile->detached)
1841 ret = -EINVAL;
1842 else
1843 __tun_detach(tfile, false);
1844 } else
1845 ret = -EINVAL;
1846
1847unlock:
1848 rtnl_unlock();
1849 return ret;
1850}
1851
1852static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
1853 unsigned long arg, int ifreq_len)
1854{
1855 struct tun_file *tfile = file->private_data;
1856 struct tun_struct *tun;
1857 void __user* argp = (void __user*)arg;
1858 struct ifreq ifr;
1859 kuid_t owner;
1860 kgid_t group;
1861 int sndbuf;
1862 int vnet_hdr_sz;
1863 int ret;
1864
1865 if (cmd == TUNSETIFF || cmd == TUNSETQUEUE || _IOC_TYPE(cmd) == 0x89) {
1866 if (copy_from_user(&ifr, argp, ifreq_len))
1867 return -EFAULT;
1868 } else {
1869 memset(&ifr, 0, sizeof(ifr));
1870 }
1871 if (cmd == TUNGETFEATURES) {
1872 /* Currently this just means: "what IFF flags are valid?".
1873 * This is needed because we never checked for invalid flags on
1874 * TUNSETIFF. */
1875 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
1876 IFF_VNET_HDR | IFF_MULTI_QUEUE,
1877 (unsigned int __user*)argp);
1878 } else if (cmd == TUNSETQUEUE)
1879 return tun_set_queue(file, &ifr);
1880
1881 ret = 0;
1882 rtnl_lock();
1883
1884 tun = __tun_get(tfile);
1885 if (cmd == TUNSETIFF && !tun) {
1886 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1887
1888 ret = tun_set_iff(tfile->net, file, &ifr);
1889
1890 if (ret)
1891 goto unlock;
1892
1893 if (copy_to_user(argp, &ifr, ifreq_len))
1894 ret = -EFAULT;
1895 goto unlock;
1896 }
1897
1898 ret = -EBADFD;
1899 if (!tun)
1900 goto unlock;
1901
1902 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %u\n", cmd);
1903
1904 ret = 0;
1905 switch (cmd) {
1906 case TUNGETIFF:
1907 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1908
1909 if (copy_to_user(argp, &ifr, ifreq_len))
1910 ret = -EFAULT;
1911 break;
1912
1913 case TUNSETNOCSUM:
1914 /* Disable/Enable checksum */
1915
1916 /* [unimplemented] */
1917 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n",
1918 arg ? "disabled" : "enabled");
1919 break;
1920
1921 case TUNSETPERSIST:
1922 /* Disable/Enable persist mode. Keep an extra reference to the
1923 * module to prevent the module being unprobed.
1924 */
1925 if (arg && !(tun->flags & TUN_PERSIST)) {
1926 tun->flags |= TUN_PERSIST;
1927 __module_get(THIS_MODULE);
1928 }
1929 if (!arg && (tun->flags & TUN_PERSIST)) {
1930 tun->flags &= ~TUN_PERSIST;
1931 module_put(THIS_MODULE);
1932 }
1933
1934 tun_debug(KERN_INFO, tun, "persist %s\n",
1935 arg ? "enabled" : "disabled");
1936 break;
1937
1938 case TUNSETOWNER:
1939 /* Set owner of the device */
1940 owner = make_kuid(current_user_ns(), arg);
1941 if (!uid_valid(owner)) {
1942 ret = -EINVAL;
1943 break;
1944 }
1945 tun->owner = owner;
1946 tun_debug(KERN_INFO, tun, "owner set to %u\n",
1947 from_kuid(&init_user_ns, tun->owner));
1948 break;
1949
1950 case TUNSETGROUP:
1951 /* Set group of the device */
1952 group = make_kgid(current_user_ns(), arg);
1953 if (!gid_valid(group)) {
1954 ret = -EINVAL;
1955 break;
1956 }
1957 tun->group = group;
1958 tun_debug(KERN_INFO, tun, "group set to %u\n",
1959 from_kgid(&init_user_ns, tun->group));
1960 break;
1961
1962 case TUNSETLINK:
1963 /* Only allow setting the type when the interface is down */
1964 if (tun->dev->flags & IFF_UP) {
1965 tun_debug(KERN_INFO, tun,
1966 "Linktype set failed because interface is up\n");
1967 ret = -EBUSY;
1968 } else {
1969 tun->dev->type = (int) arg;
1970 tun_debug(KERN_INFO, tun, "linktype set to %d\n",
1971 tun->dev->type);
1972 ret = 0;
1973 }
1974 break;
1975
1976#ifdef TUN_DEBUG
1977 case TUNSETDEBUG:
1978 tun->debug = arg;
1979 break;
1980#endif
1981 case TUNSETOFFLOAD:
1982 ret = set_offload(tun, arg);
1983 break;
1984
1985 case TUNSETTXFILTER:
1986 /* Can be set only for TAPs */
1987 ret = -EINVAL;
1988 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1989 break;
1990 ret = update_filter(&tun->txflt, (void __user *)arg);
1991 break;
1992
1993 case SIOCGIFHWADDR:
1994 /* Get hw address */
1995 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
1996 ifr.ifr_hwaddr.sa_family = tun->dev->type;
1997 if (copy_to_user(argp, &ifr, ifreq_len))
1998 ret = -EFAULT;
1999 break;
2000
2001 case SIOCSIFHWADDR:
2002 /* Set hw address */
2003 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
2004 ifr.ifr_hwaddr.sa_data);
2005
2006 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
2007 break;
2008
2009 case TUNGETSNDBUF:
2010 sndbuf = tfile->socket.sk->sk_sndbuf;
2011 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
2012 ret = -EFAULT;
2013 break;
2014
2015 case TUNSETSNDBUF:
2016 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
2017 ret = -EFAULT;
2018 break;
2019 }
2020
2021 tun->sndbuf = sndbuf;
2022 tun_set_sndbuf(tun);
2023 break;
2024
2025 case TUNGETVNETHDRSZ:
2026 vnet_hdr_sz = tun->vnet_hdr_sz;
2027 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
2028 ret = -EFAULT;
2029 break;
2030
2031 case TUNSETVNETHDRSZ:
2032 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
2033 ret = -EFAULT;
2034 break;
2035 }
2036 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
2037 ret = -EINVAL;
2038 break;
2039 }
2040
2041 tun->vnet_hdr_sz = vnet_hdr_sz;
2042 break;
2043
2044 case TUNATTACHFILTER:
2045 /* Can be set only for TAPs */
2046 ret = -EINVAL;
2047 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
2048 break;
2049 ret = -EFAULT;
2050 if (copy_from_user(&tun->fprog, argp, sizeof(tun->fprog)))
2051 break;
2052
2053 ret = tun_attach_filter(tun);
2054 break;
2055
2056 case TUNDETACHFILTER:
2057 /* Can be set only for TAPs */
2058 ret = -EINVAL;
2059 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
2060 break;
2061 ret = 0;
2062 tun_detach_filter(tun, tun->numqueues);
2063 break;
2064
2065 default:
2066 ret = -EINVAL;
2067 break;
2068 }
2069
2070unlock:
2071 rtnl_unlock();
2072 if (tun)
2073 tun_put(tun);
2074 return ret;
2075}
2076
2077static long tun_chr_ioctl(struct file *file,
2078 unsigned int cmd, unsigned long arg)
2079{
2080 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
2081}
2082
2083#ifdef CONFIG_COMPAT
2084static long tun_chr_compat_ioctl(struct file *file,
2085 unsigned int cmd, unsigned long arg)
2086{
2087 switch (cmd) {
2088 case TUNSETIFF:
2089 case TUNGETIFF:
2090 case TUNSETTXFILTER:
2091 case TUNGETSNDBUF:
2092 case TUNSETSNDBUF:
2093 case SIOCGIFHWADDR:
2094 case SIOCSIFHWADDR:
2095 arg = (unsigned long)compat_ptr(arg);
2096 break;
2097 default:
2098 arg = (compat_ulong_t)arg;
2099 break;
2100 }
2101
2102 /*
2103 * compat_ifreq is shorter than ifreq, so we must not access beyond
2104 * the end of that structure. All fields that are used in this
2105 * driver are compatible though, we don't need to convert the
2106 * contents.
2107 */
2108 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
2109}
2110#endif /* CONFIG_COMPAT */
2111
2112static int tun_chr_fasync(int fd, struct file *file, int on)
2113{
2114 struct tun_file *tfile = file->private_data;
2115 int ret;
2116
2117 if ((ret = fasync_helper(fd, file, on, &tfile->fasync)) < 0)
2118 goto out;
2119
2120 if (on) {
2121 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
2122 if (ret)
2123 goto out;
2124 tfile->flags |= TUN_FASYNC;
2125 } else
2126 tfile->flags &= ~TUN_FASYNC;
2127 ret = 0;
2128out:
2129 return ret;
2130}
2131
2132static int tun_chr_open(struct inode *inode, struct file * file)
2133{
2134 struct tun_file *tfile;
2135
2136 DBG1(KERN_INFO, "tunX: tun_chr_open\n");
2137
2138 tfile = (struct tun_file *)sk_alloc(&init_net, AF_UNSPEC, GFP_KERNEL,
2139 &tun_proto);
2140 if (!tfile)
2141 return -ENOMEM;
2142 rcu_assign_pointer(tfile->tun, NULL);
2143 tfile->net = get_net(current->nsproxy->net_ns);
2144 tfile->flags = 0;
2145
2146 rcu_assign_pointer(tfile->socket.wq, &tfile->wq);
2147 init_waitqueue_head(&tfile->wq.wait);
2148
2149 tfile->socket.file = file;
2150 tfile->socket.ops = &tun_socket_ops;
2151
2152 sock_init_data(&tfile->socket, &tfile->sk);
2153 sk_change_net(&tfile->sk, tfile->net);
2154
2155 tfile->sk.sk_write_space = tun_sock_write_space;
2156 tfile->sk.sk_sndbuf = INT_MAX;
2157
2158 file->private_data = tfile;
2159 set_bit(SOCK_EXTERNALLY_ALLOCATED, &tfile->socket.flags);
2160 INIT_LIST_HEAD(&tfile->next);
2161
2162 return 0;
2163}
2164
2165static int tun_chr_close(struct inode *inode, struct file *file)
2166{
2167 struct tun_file *tfile = file->private_data;
2168 struct net *net = tfile->net;
2169
2170 tun_detach(tfile, true);
2171 put_net(net);
2172
2173 return 0;
2174}
2175
2176static const struct file_operations tun_fops = {
2177 .owner = THIS_MODULE,
2178 .llseek = no_llseek,
2179 .read = do_sync_read,
2180 .aio_read = tun_chr_aio_read,
2181 .write = do_sync_write,
2182 .aio_write = tun_chr_aio_write,
2183 .poll = tun_chr_poll,
2184 .unlocked_ioctl = tun_chr_ioctl,
2185#ifdef CONFIG_COMPAT
2186 .compat_ioctl = tun_chr_compat_ioctl,
2187#endif
2188 .open = tun_chr_open,
2189 .release = tun_chr_close,
2190 .fasync = tun_chr_fasync
2191};
2192
2193static struct miscdevice tun_miscdev = {
2194 .minor = TUN_MINOR,
2195 .name = "tun",
2196 .nodename = "net/tun",
2197 .fops = &tun_fops,
2198};
2199
2200/* ethtool interface */
2201
2202static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
2203{
2204 cmd->supported = 0;
2205 cmd->advertising = 0;
2206 ethtool_cmd_speed_set(cmd, SPEED_10);
2207 cmd->duplex = DUPLEX_FULL;
2208 cmd->port = PORT_TP;
2209 cmd->phy_address = 0;
2210 cmd->transceiver = XCVR_INTERNAL;
2211 cmd->autoneg = AUTONEG_DISABLE;
2212 cmd->maxtxpkt = 0;
2213 cmd->maxrxpkt = 0;
2214 return 0;
2215}
2216
2217static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
2218{
2219 struct tun_struct *tun = netdev_priv(dev);
2220
2221 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
2222 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
2223
2224 switch (tun->flags & TUN_TYPE_MASK) {
2225 case TUN_TUN_DEV:
2226 strlcpy(info->bus_info, "tun", sizeof(info->bus_info));
2227 break;
2228 case TUN_TAP_DEV:
2229 strlcpy(info->bus_info, "tap", sizeof(info->bus_info));
2230 break;
2231 }
2232}
2233
2234static u32 tun_get_msglevel(struct net_device *dev)
2235{
2236#ifdef TUN_DEBUG
2237 struct tun_struct *tun = netdev_priv(dev);
2238 return tun->debug;
2239#else
2240 return -EOPNOTSUPP;
2241#endif
2242}
2243
2244static void tun_set_msglevel(struct net_device *dev, u32 value)
2245{
2246#ifdef TUN_DEBUG
2247 struct tun_struct *tun = netdev_priv(dev);
2248 tun->debug = value;
2249#endif
2250}
2251
2252static const struct ethtool_ops tun_ethtool_ops = {
2253 .get_settings = tun_get_settings,
2254 .get_drvinfo = tun_get_drvinfo,
2255 .get_msglevel = tun_get_msglevel,
2256 .set_msglevel = tun_set_msglevel,
2257 .get_link = ethtool_op_get_link,
2258};
2259
2260
2261static int __init tun_init(void)
2262{
2263 int ret = 0;
2264
2265 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
2266 pr_info("%s\n", DRV_COPYRIGHT);
2267
2268 ret = rtnl_link_register(&tun_link_ops);
2269 if (ret) {
2270 pr_err("Can't register link_ops\n");
2271 goto err_linkops;
2272 }
2273
2274 ret = misc_register(&tun_miscdev);
2275 if (ret) {
2276 pr_err("Can't register misc device %d\n", TUN_MINOR);
2277 goto err_misc;
2278 }
2279 return 0;
2280err_misc:
2281 rtnl_link_unregister(&tun_link_ops);
2282err_linkops:
2283 return ret;
2284}
2285
2286static void tun_cleanup(void)
2287{
2288 misc_deregister(&tun_miscdev);
2289 rtnl_link_unregister(&tun_link_ops);
2290}
2291
2292/* Get an underlying socket object from tun file. Returns error unless file is
2293 * attached to a device. The returned object works like a packet socket, it
2294 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
2295 * holding a reference to the file for as long as the socket is in use. */
2296struct socket *tun_get_socket(struct file *file)
2297{
2298 struct tun_file *tfile;
2299 if (file->f_op != &tun_fops)
2300 return ERR_PTR(-EINVAL);
2301 tfile = file->private_data;
2302 if (!tfile)
2303 return ERR_PTR(-EBADFD);
2304 return &tfile->socket;
2305}
2306EXPORT_SYMBOL_GPL(tun_get_socket);
2307
2308module_init(tun_init);
2309module_exit(tun_cleanup);
2310MODULE_DESCRIPTION(DRV_DESCRIPTION);
2311MODULE_AUTHOR(DRV_COPYRIGHT);
2312MODULE_LICENSE("GPL");
2313MODULE_ALIAS_MISCDEV(TUN_MINOR);
2314MODULE_ALIAS("devname:net/tun");
kernel source for telekom puls (alcatel/mediatek)