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tun: TUNGETIFF interface to query name and flags
[deliverable/linux.git] / drivers / net / tun.c
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 random_ether_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 DRV_NAME "tun"
38 #define DRV_VERSION "1.6"
39 #define DRV_DESCRIPTION "Universal TUN/TAP device driver"
40 #define DRV_COPYRIGHT "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>"
41
42 #include <linux/module.h>
43 #include <linux/errno.h>
44 #include <linux/kernel.h>
45 #include <linux/major.h>
46 #include <linux/slab.h>
47 #include <linux/smp_lock.h>
48 #include <linux/poll.h>
49 #include <linux/fcntl.h>
50 #include <linux/init.h>
51 #include <linux/skbuff.h>
52 #include <linux/netdevice.h>
53 #include <linux/etherdevice.h>
54 #include <linux/miscdevice.h>
55 #include <linux/ethtool.h>
56 #include <linux/rtnetlink.h>
57 #include <linux/if.h>
58 #include <linux/if_arp.h>
59 #include <linux/if_ether.h>
60 #include <linux/if_tun.h>
61 #include <linux/crc32.h>
62 #include <linux/nsproxy.h>
63 #include <linux/virtio_net.h>
64 #include <net/net_namespace.h>
65 #include <net/netns/generic.h>
66
67 #include <asm/system.h>
68 #include <asm/uaccess.h>
69
70 /* Uncomment to enable debugging */
71 /* #define TUN_DEBUG 1 */
72
73 #ifdef TUN_DEBUG
74 static int debug;
75
76 #define DBG if(tun->debug)printk
77 #define DBG1 if(debug==2)printk
78 #else
79 #define DBG( a... )
80 #define DBG1( a... )
81 #endif
82
83 #define FLT_EXACT_COUNT 8
84 struct tap_filter {
85 unsigned int count; /* Number of addrs. Zero means disabled */
86 u32 mask[2]; /* Mask of the hashed addrs */
87 unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN];
88 };
89
90 struct tun_struct {
91 struct list_head list;
92 unsigned int flags;
93 int attached;
94 uid_t owner;
95 gid_t group;
96
97 wait_queue_head_t read_wait;
98 struct sk_buff_head readq;
99
100 struct net_device *dev;
101 struct fasync_struct *fasync;
102
103 struct tap_filter txflt;
104
105 #ifdef TUN_DEBUG
106 int debug;
107 #endif
108 };
109
110 /* TAP filterting */
111 static void addr_hash_set(u32 *mask, const u8 *addr)
112 {
113 int n = ether_crc(ETH_ALEN, addr) >> 26;
114 mask[n >> 5] |= (1 << (n & 31));
115 }
116
117 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
118 {
119 int n = ether_crc(ETH_ALEN, addr) >> 26;
120 return mask[n >> 5] & (1 << (n & 31));
121 }
122
123 static int update_filter(struct tap_filter *filter, void __user *arg)
124 {
125 struct { u8 u[ETH_ALEN]; } *addr;
126 struct tun_filter uf;
127 int err, alen, n, nexact;
128
129 if (copy_from_user(&uf, arg, sizeof(uf)))
130 return -EFAULT;
131
132 if (!uf.count) {
133 /* Disabled */
134 filter->count = 0;
135 return 0;
136 }
137
138 alen = ETH_ALEN * uf.count;
139 addr = kmalloc(alen, GFP_KERNEL);
140 if (!addr)
141 return -ENOMEM;
142
143 if (copy_from_user(addr, arg + sizeof(uf), alen)) {
144 err = -EFAULT;
145 goto done;
146 }
147
148 /* The filter is updated without holding any locks. Which is
149 * perfectly safe. We disable it first and in the worst
150 * case we'll accept a few undesired packets. */
151 filter->count = 0;
152 wmb();
153
154 /* Use first set of addresses as an exact filter */
155 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
156 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
157
158 nexact = n;
159
160 /* The rest is hashed */
161 memset(filter->mask, 0, sizeof(filter->mask));
162 for (; n < uf.count; n++)
163 addr_hash_set(filter->mask, addr[n].u);
164
165 /* For ALLMULTI just set the mask to all ones.
166 * This overrides the mask populated above. */
167 if ((uf.flags & TUN_FLT_ALLMULTI))
168 memset(filter->mask, ~0, sizeof(filter->mask));
169
170 /* Now enable the filter */
171 wmb();
172 filter->count = nexact;
173
174 /* Return the number of exact filters */
175 err = nexact;
176
177 done:
178 kfree(addr);
179 return err;
180 }
181
182 /* Returns: 0 - drop, !=0 - accept */
183 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
184 {
185 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
186 * at this point. */
187 struct ethhdr *eh = (struct ethhdr *) skb->data;
188 int i;
189
190 /* Exact match */
191 for (i = 0; i < filter->count; i++)
192 if (!compare_ether_addr(eh->h_dest, filter->addr[i]))
193 return 1;
194
195 /* Inexact match (multicast only) */
196 if (is_multicast_ether_addr(eh->h_dest))
197 return addr_hash_test(filter->mask, eh->h_dest);
198
199 return 0;
200 }
201
202 /*
203 * Checks whether the packet is accepted or not.
204 * Returns: 0 - drop, !=0 - accept
205 */
206 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
207 {
208 if (!filter->count)
209 return 1;
210
211 return run_filter(filter, skb);
212 }
213
214 /* Network device part of the driver */
215
216 static unsigned int tun_net_id;
217 struct tun_net {
218 struct list_head dev_list;
219 };
220
221 static const struct ethtool_ops tun_ethtool_ops;
222
223 /* Net device open. */
224 static int tun_net_open(struct net_device *dev)
225 {
226 netif_start_queue(dev);
227 return 0;
228 }
229
230 /* Net device close. */
231 static int tun_net_close(struct net_device *dev)
232 {
233 netif_stop_queue(dev);
234 return 0;
235 }
236
237 /* Net device start xmit */
238 static int tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
239 {
240 struct tun_struct *tun = netdev_priv(dev);
241
242 DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len);
243
244 /* Drop packet if interface is not attached */
245 if (!tun->attached)
246 goto drop;
247
248 /* Drop if the filter does not like it.
249 * This is a noop if the filter is disabled.
250 * Filter can be enabled only for the TAP devices. */
251 if (!check_filter(&tun->txflt, skb))
252 goto drop;
253
254 if (skb_queue_len(&tun->readq) >= dev->tx_queue_len) {
255 if (!(tun->flags & TUN_ONE_QUEUE)) {
256 /* Normal queueing mode. */
257 /* Packet scheduler handles dropping of further packets. */
258 netif_stop_queue(dev);
259
260 /* We won't see all dropped packets individually, so overrun
261 * error is more appropriate. */
262 dev->stats.tx_fifo_errors++;
263 } else {
264 /* Single queue mode.
265 * Driver handles dropping of all packets itself. */
266 goto drop;
267 }
268 }
269
270 /* Enqueue packet */
271 skb_queue_tail(&tun->readq, skb);
272 dev->trans_start = jiffies;
273
274 /* Notify and wake up reader process */
275 if (tun->flags & TUN_FASYNC)
276 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
277 wake_up_interruptible(&tun->read_wait);
278 return 0;
279
280 drop:
281 dev->stats.tx_dropped++;
282 kfree_skb(skb);
283 return 0;
284 }
285
286 static void tun_net_mclist(struct net_device *dev)
287 {
288 /*
289 * This callback is supposed to deal with mc filter in
290 * _rx_ path and has nothing to do with the _tx_ path.
291 * In rx path we always accept everything userspace gives us.
292 */
293 return;
294 }
295
296 #define MIN_MTU 68
297 #define MAX_MTU 65535
298
299 static int
300 tun_net_change_mtu(struct net_device *dev, int new_mtu)
301 {
302 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
303 return -EINVAL;
304 dev->mtu = new_mtu;
305 return 0;
306 }
307
308 /* Initialize net device. */
309 static void tun_net_init(struct net_device *dev)
310 {
311 struct tun_struct *tun = netdev_priv(dev);
312
313 switch (tun->flags & TUN_TYPE_MASK) {
314 case TUN_TUN_DEV:
315 /* Point-to-Point TUN Device */
316 dev->hard_header_len = 0;
317 dev->addr_len = 0;
318 dev->mtu = 1500;
319 dev->change_mtu = tun_net_change_mtu;
320
321 /* Zero header length */
322 dev->type = ARPHRD_NONE;
323 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
324 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
325 break;
326
327 case TUN_TAP_DEV:
328 /* Ethernet TAP Device */
329 ether_setup(dev);
330 dev->change_mtu = tun_net_change_mtu;
331 dev->set_multicast_list = tun_net_mclist;
332
333 random_ether_addr(dev->dev_addr);
334
335 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
336 break;
337 }
338 }
339
340 /* Character device part */
341
342 /* Poll */
343 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
344 {
345 struct tun_struct *tun = file->private_data;
346 unsigned int mask = POLLOUT | POLLWRNORM;
347
348 if (!tun)
349 return -EBADFD;
350
351 DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
352
353 poll_wait(file, &tun->read_wait, wait);
354
355 if (!skb_queue_empty(&tun->readq))
356 mask |= POLLIN | POLLRDNORM;
357
358 return mask;
359 }
360
361 /* Get packet from user space buffer */
362 static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, size_t count)
363 {
364 struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) };
365 struct sk_buff *skb;
366 size_t len = count, align = 0;
367 struct virtio_net_hdr gso = { 0 };
368
369 if (!(tun->flags & TUN_NO_PI)) {
370 if ((len -= sizeof(pi)) > count)
371 return -EINVAL;
372
373 if(memcpy_fromiovec((void *)&pi, iv, sizeof(pi)))
374 return -EFAULT;
375 }
376
377 if (tun->flags & TUN_VNET_HDR) {
378 if ((len -= sizeof(gso)) > count)
379 return -EINVAL;
380
381 if (memcpy_fromiovec((void *)&gso, iv, sizeof(gso)))
382 return -EFAULT;
383
384 if (gso.hdr_len > len)
385 return -EINVAL;
386 }
387
388 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
389 align = NET_IP_ALIGN;
390 if (unlikely(len < ETH_HLEN))
391 return -EINVAL;
392 }
393
394 if (!(skb = alloc_skb(len + align, GFP_KERNEL))) {
395 tun->dev->stats.rx_dropped++;
396 return -ENOMEM;
397 }
398
399 if (align)
400 skb_reserve(skb, align);
401 if (memcpy_fromiovec(skb_put(skb, len), iv, len)) {
402 tun->dev->stats.rx_dropped++;
403 kfree_skb(skb);
404 return -EFAULT;
405 }
406
407 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
408 if (!skb_partial_csum_set(skb, gso.csum_start,
409 gso.csum_offset)) {
410 tun->dev->stats.rx_frame_errors++;
411 kfree_skb(skb);
412 return -EINVAL;
413 }
414 } else if (tun->flags & TUN_NOCHECKSUM)
415 skb->ip_summed = CHECKSUM_UNNECESSARY;
416
417 switch (tun->flags & TUN_TYPE_MASK) {
418 case TUN_TUN_DEV:
419 if (tun->flags & TUN_NO_PI) {
420 switch (skb->data[0] & 0xf0) {
421 case 0x40:
422 pi.proto = htons(ETH_P_IP);
423 break;
424 case 0x60:
425 pi.proto = htons(ETH_P_IPV6);
426 break;
427 default:
428 tun->dev->stats.rx_dropped++;
429 kfree_skb(skb);
430 return -EINVAL;
431 }
432 }
433
434 skb_reset_mac_header(skb);
435 skb->protocol = pi.proto;
436 skb->dev = tun->dev;
437 break;
438 case TUN_TAP_DEV:
439 skb->protocol = eth_type_trans(skb, tun->dev);
440 break;
441 };
442
443 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
444 pr_debug("GSO!\n");
445 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
446 case VIRTIO_NET_HDR_GSO_TCPV4:
447 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
448 break;
449 case VIRTIO_NET_HDR_GSO_TCPV6:
450 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
451 break;
452 default:
453 tun->dev->stats.rx_frame_errors++;
454 kfree_skb(skb);
455 return -EINVAL;
456 }
457
458 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
459 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
460
461 skb_shinfo(skb)->gso_size = gso.gso_size;
462 if (skb_shinfo(skb)->gso_size == 0) {
463 tun->dev->stats.rx_frame_errors++;
464 kfree_skb(skb);
465 return -EINVAL;
466 }
467
468 /* Header must be checked, and gso_segs computed. */
469 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
470 skb_shinfo(skb)->gso_segs = 0;
471 }
472
473 netif_rx_ni(skb);
474 tun->dev->last_rx = jiffies;
475
476 tun->dev->stats.rx_packets++;
477 tun->dev->stats.rx_bytes += len;
478
479 return count;
480 }
481
482 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
483 unsigned long count, loff_t pos)
484 {
485 struct tun_struct *tun = iocb->ki_filp->private_data;
486
487 if (!tun)
488 return -EBADFD;
489
490 DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
491
492 return tun_get_user(tun, (struct iovec *) iv, iov_length(iv, count));
493 }
494
495 /* Put packet to the user space buffer */
496 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
497 struct sk_buff *skb,
498 struct iovec *iv, int len)
499 {
500 struct tun_pi pi = { 0, skb->protocol };
501 ssize_t total = 0;
502
503 if (!(tun->flags & TUN_NO_PI)) {
504 if ((len -= sizeof(pi)) < 0)
505 return -EINVAL;
506
507 if (len < skb->len) {
508 /* Packet will be striped */
509 pi.flags |= TUN_PKT_STRIP;
510 }
511
512 if (memcpy_toiovec(iv, (void *) &pi, sizeof(pi)))
513 return -EFAULT;
514 total += sizeof(pi);
515 }
516
517 if (tun->flags & TUN_VNET_HDR) {
518 struct virtio_net_hdr gso = { 0 }; /* no info leak */
519 if ((len -= sizeof(gso)) < 0)
520 return -EINVAL;
521
522 if (skb_is_gso(skb)) {
523 struct skb_shared_info *sinfo = skb_shinfo(skb);
524
525 /* This is a hint as to how much should be linear. */
526 gso.hdr_len = skb_headlen(skb);
527 gso.gso_size = sinfo->gso_size;
528 if (sinfo->gso_type & SKB_GSO_TCPV4)
529 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
530 else if (sinfo->gso_type & SKB_GSO_TCPV6)
531 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
532 else
533 BUG();
534 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
535 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
536 } else
537 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
538
539 if (skb->ip_summed == CHECKSUM_PARTIAL) {
540 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
541 gso.csum_start = skb->csum_start - skb_headroom(skb);
542 gso.csum_offset = skb->csum_offset;
543 } /* else everything is zero */
544
545 if (unlikely(memcpy_toiovec(iv, (void *)&gso, sizeof(gso))))
546 return -EFAULT;
547 total += sizeof(gso);
548 }
549
550 len = min_t(int, skb->len, len);
551
552 skb_copy_datagram_iovec(skb, 0, iv, len);
553 total += len;
554
555 tun->dev->stats.tx_packets++;
556 tun->dev->stats.tx_bytes += len;
557
558 return total;
559 }
560
561 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
562 unsigned long count, loff_t pos)
563 {
564 struct file *file = iocb->ki_filp;
565 struct tun_struct *tun = file->private_data;
566 DECLARE_WAITQUEUE(wait, current);
567 struct sk_buff *skb;
568 ssize_t len, ret = 0;
569
570 if (!tun)
571 return -EBADFD;
572
573 DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
574
575 len = iov_length(iv, count);
576 if (len < 0)
577 return -EINVAL;
578
579 add_wait_queue(&tun->read_wait, &wait);
580 while (len) {
581 current->state = TASK_INTERRUPTIBLE;
582
583 /* Read frames from the queue */
584 if (!(skb=skb_dequeue(&tun->readq))) {
585 if (file->f_flags & O_NONBLOCK) {
586 ret = -EAGAIN;
587 break;
588 }
589 if (signal_pending(current)) {
590 ret = -ERESTARTSYS;
591 break;
592 }
593
594 /* Nothing to read, let's sleep */
595 schedule();
596 continue;
597 }
598 netif_wake_queue(tun->dev);
599
600 ret = tun_put_user(tun, skb, (struct iovec *) iv, len);
601 kfree_skb(skb);
602 break;
603 }
604
605 current->state = TASK_RUNNING;
606 remove_wait_queue(&tun->read_wait, &wait);
607
608 return ret;
609 }
610
611 static void tun_setup(struct net_device *dev)
612 {
613 struct tun_struct *tun = netdev_priv(dev);
614
615 skb_queue_head_init(&tun->readq);
616 init_waitqueue_head(&tun->read_wait);
617
618 tun->owner = -1;
619 tun->group = -1;
620
621 dev->open = tun_net_open;
622 dev->hard_start_xmit = tun_net_xmit;
623 dev->stop = tun_net_close;
624 dev->ethtool_ops = &tun_ethtool_ops;
625 dev->destructor = free_netdev;
626 dev->features |= NETIF_F_NETNS_LOCAL;
627 }
628
629 static struct tun_struct *tun_get_by_name(struct tun_net *tn, const char *name)
630 {
631 struct tun_struct *tun;
632
633 ASSERT_RTNL();
634 list_for_each_entry(tun, &tn->dev_list, list) {
635 if (!strncmp(tun->dev->name, name, IFNAMSIZ))
636 return tun;
637 }
638
639 return NULL;
640 }
641
642 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
643 {
644 struct tun_net *tn;
645 struct tun_struct *tun;
646 struct net_device *dev;
647 int err;
648
649 tn = net_generic(net, tun_net_id);
650 tun = tun_get_by_name(tn, ifr->ifr_name);
651 if (tun) {
652 if (tun->attached)
653 return -EBUSY;
654
655 /* Check permissions */
656 if (((tun->owner != -1 &&
657 current->euid != tun->owner) ||
658 (tun->group != -1 &&
659 current->egid != tun->group)) &&
660 !capable(CAP_NET_ADMIN))
661 return -EPERM;
662 }
663 else if (__dev_get_by_name(net, ifr->ifr_name))
664 return -EINVAL;
665 else {
666 char *name;
667 unsigned long flags = 0;
668
669 err = -EINVAL;
670
671 if (!capable(CAP_NET_ADMIN))
672 return -EPERM;
673
674 /* Set dev type */
675 if (ifr->ifr_flags & IFF_TUN) {
676 /* TUN device */
677 flags |= TUN_TUN_DEV;
678 name = "tun%d";
679 } else if (ifr->ifr_flags & IFF_TAP) {
680 /* TAP device */
681 flags |= TUN_TAP_DEV;
682 name = "tap%d";
683 } else
684 goto failed;
685
686 if (*ifr->ifr_name)
687 name = ifr->ifr_name;
688
689 dev = alloc_netdev(sizeof(struct tun_struct), name,
690 tun_setup);
691 if (!dev)
692 return -ENOMEM;
693
694 dev_net_set(dev, net);
695 tun = netdev_priv(dev);
696 tun->dev = dev;
697 tun->flags = flags;
698 tun->txflt.count = 0;
699
700 tun_net_init(dev);
701
702 if (strchr(dev->name, '%')) {
703 err = dev_alloc_name(dev, dev->name);
704 if (err < 0)
705 goto err_free_dev;
706 }
707
708 err = register_netdevice(tun->dev);
709 if (err < 0)
710 goto err_free_dev;
711
712 list_add(&tun->list, &tn->dev_list);
713 }
714
715 DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
716
717 if (ifr->ifr_flags & IFF_NO_PI)
718 tun->flags |= TUN_NO_PI;
719 else
720 tun->flags &= ~TUN_NO_PI;
721
722 if (ifr->ifr_flags & IFF_ONE_QUEUE)
723 tun->flags |= TUN_ONE_QUEUE;
724 else
725 tun->flags &= ~TUN_ONE_QUEUE;
726
727 if (ifr->ifr_flags & IFF_VNET_HDR)
728 tun->flags |= TUN_VNET_HDR;
729 else
730 tun->flags &= ~TUN_VNET_HDR;
731
732 file->private_data = tun;
733 tun->attached = 1;
734 get_net(dev_net(tun->dev));
735
736 /* Make sure persistent devices do not get stuck in
737 * xoff state.
738 */
739 if (netif_running(tun->dev))
740 netif_wake_queue(tun->dev);
741
742 strcpy(ifr->ifr_name, tun->dev->name);
743 return 0;
744
745 err_free_dev:
746 free_netdev(dev);
747 failed:
748 return err;
749 }
750
751 static int tun_get_iff(struct net *net, struct file *file, struct ifreq *ifr)
752 {
753 struct tun_struct *tun = file->private_data;
754
755 if (!tun)
756 return -EBADFD;
757
758 DBG(KERN_INFO "%s: tun_get_iff\n", tun->dev->name);
759
760 strcpy(ifr->ifr_name, tun->dev->name);
761
762 ifr->ifr_flags = 0;
763
764 if (ifr->ifr_flags & TUN_TUN_DEV)
765 ifr->ifr_flags |= IFF_TUN;
766 else
767 ifr->ifr_flags |= IFF_TAP;
768
769 if (tun->flags & TUN_NO_PI)
770 ifr->ifr_flags |= IFF_NO_PI;
771
772 if (tun->flags & TUN_ONE_QUEUE)
773 ifr->ifr_flags |= IFF_ONE_QUEUE;
774
775 if (tun->flags & TUN_VNET_HDR)
776 ifr->ifr_flags |= IFF_VNET_HDR;
777
778 return 0;
779 }
780
781 /* This is like a cut-down ethtool ops, except done via tun fd so no
782 * privs required. */
783 static int set_offload(struct net_device *dev, unsigned long arg)
784 {
785 unsigned int old_features, features;
786
787 old_features = dev->features;
788 /* Unset features, set them as we chew on the arg. */
789 features = (old_features & ~(NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST
790 |NETIF_F_TSO_ECN|NETIF_F_TSO|NETIF_F_TSO6));
791
792 if (arg & TUN_F_CSUM) {
793 features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
794 arg &= ~TUN_F_CSUM;
795
796 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
797 if (arg & TUN_F_TSO_ECN) {
798 features |= NETIF_F_TSO_ECN;
799 arg &= ~TUN_F_TSO_ECN;
800 }
801 if (arg & TUN_F_TSO4)
802 features |= NETIF_F_TSO;
803 if (arg & TUN_F_TSO6)
804 features |= NETIF_F_TSO6;
805 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
806 }
807 }
808
809 /* This gives the user a way to test for new features in future by
810 * trying to set them. */
811 if (arg)
812 return -EINVAL;
813
814 dev->features = features;
815 if (old_features != dev->features)
816 netdev_features_change(dev);
817
818 return 0;
819 }
820
821 static int tun_chr_ioctl(struct inode *inode, struct file *file,
822 unsigned int cmd, unsigned long arg)
823 {
824 struct tun_struct *tun = file->private_data;
825 void __user* argp = (void __user*)arg;
826 struct ifreq ifr;
827 int ret;
828 DECLARE_MAC_BUF(mac);
829
830 if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
831 if (copy_from_user(&ifr, argp, sizeof ifr))
832 return -EFAULT;
833
834 if (cmd == TUNSETIFF && !tun) {
835 int err;
836
837 ifr.ifr_name[IFNAMSIZ-1] = '\0';
838
839 rtnl_lock();
840 err = tun_set_iff(current->nsproxy->net_ns, file, &ifr);
841 rtnl_unlock();
842
843 if (err)
844 return err;
845
846 if (copy_to_user(argp, &ifr, sizeof(ifr)))
847 return -EFAULT;
848 return 0;
849 }
850
851 if (cmd == TUNGETFEATURES) {
852 /* Currently this just means: "what IFF flags are valid?".
853 * This is needed because we never checked for invalid flags on
854 * TUNSETIFF. */
855 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
856 IFF_VNET_HDR,
857 (unsigned int __user*)argp);
858 }
859
860 if (!tun)
861 return -EBADFD;
862
863 DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
864
865 switch (cmd) {
866 case TUNGETIFF:
867 ret = tun_get_iff(current->nsproxy->net_ns, file, &ifr);
868 if (ret)
869 return ret;
870
871 if (copy_to_user(argp, &ifr, sizeof(ifr)))
872 return -EFAULT;
873 break;
874
875 case TUNSETNOCSUM:
876 /* Disable/Enable checksum */
877 if (arg)
878 tun->flags |= TUN_NOCHECKSUM;
879 else
880 tun->flags &= ~TUN_NOCHECKSUM;
881
882 DBG(KERN_INFO "%s: checksum %s\n",
883 tun->dev->name, arg ? "disabled" : "enabled");
884 break;
885
886 case TUNSETPERSIST:
887 /* Disable/Enable persist mode */
888 if (arg)
889 tun->flags |= TUN_PERSIST;
890 else
891 tun->flags &= ~TUN_PERSIST;
892
893 DBG(KERN_INFO "%s: persist %s\n",
894 tun->dev->name, arg ? "enabled" : "disabled");
895 break;
896
897 case TUNSETOWNER:
898 /* Set owner of the device */
899 tun->owner = (uid_t) arg;
900
901 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
902 break;
903
904 case TUNSETGROUP:
905 /* Set group of the device */
906 tun->group= (gid_t) arg;
907
908 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group);
909 break;
910
911 case TUNSETLINK:
912 /* Only allow setting the type when the interface is down */
913 rtnl_lock();
914 if (tun->dev->flags & IFF_UP) {
915 DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
916 tun->dev->name);
917 ret = -EBUSY;
918 } else {
919 tun->dev->type = (int) arg;
920 DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
921 ret = 0;
922 }
923 rtnl_unlock();
924 return ret;
925
926 #ifdef TUN_DEBUG
927 case TUNSETDEBUG:
928 tun->debug = arg;
929 break;
930 #endif
931 case TUNSETOFFLOAD:
932 rtnl_lock();
933 ret = set_offload(tun->dev, arg);
934 rtnl_unlock();
935 return ret;
936
937 case TUNSETTXFILTER:
938 /* Can be set only for TAPs */
939 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
940 return -EINVAL;
941 rtnl_lock();
942 ret = update_filter(&tun->txflt, (void __user *)arg);
943 rtnl_unlock();
944 return ret;
945
946 case SIOCGIFHWADDR:
947 /* Get hw addres */
948 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
949 ifr.ifr_hwaddr.sa_family = tun->dev->type;
950 if (copy_to_user(argp, &ifr, sizeof ifr))
951 return -EFAULT;
952 return 0;
953
954 case SIOCSIFHWADDR:
955 /* Set hw address */
956 DBG(KERN_DEBUG "%s: set hw address: %s\n",
957 tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data));
958
959 rtnl_lock();
960 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
961 rtnl_unlock();
962 return ret;
963
964 default:
965 return -EINVAL;
966 };
967
968 return 0;
969 }
970
971 static int tun_chr_fasync(int fd, struct file *file, int on)
972 {
973 struct tun_struct *tun = file->private_data;
974 int ret;
975
976 if (!tun)
977 return -EBADFD;
978
979 DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
980
981 lock_kernel();
982 if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
983 goto out;
984
985 if (on) {
986 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
987 if (ret)
988 goto out;
989 tun->flags |= TUN_FASYNC;
990 } else
991 tun->flags &= ~TUN_FASYNC;
992 ret = 0;
993 out:
994 unlock_kernel();
995 return ret;
996 }
997
998 static int tun_chr_open(struct inode *inode, struct file * file)
999 {
1000 cycle_kernel_lock();
1001 DBG1(KERN_INFO "tunX: tun_chr_open\n");
1002 file->private_data = NULL;
1003 return 0;
1004 }
1005
1006 static int tun_chr_close(struct inode *inode, struct file *file)
1007 {
1008 struct tun_struct *tun = file->private_data;
1009
1010 if (!tun)
1011 return 0;
1012
1013 DBG(KERN_INFO "%s: tun_chr_close\n", tun->dev->name);
1014
1015 tun_chr_fasync(-1, file, 0);
1016
1017 rtnl_lock();
1018
1019 /* Detach from net device */
1020 file->private_data = NULL;
1021 tun->attached = 0;
1022 put_net(dev_net(tun->dev));
1023
1024 /* Drop read queue */
1025 skb_queue_purge(&tun->readq);
1026
1027 if (!(tun->flags & TUN_PERSIST)) {
1028 list_del(&tun->list);
1029 unregister_netdevice(tun->dev);
1030 }
1031
1032 rtnl_unlock();
1033
1034 return 0;
1035 }
1036
1037 static const struct file_operations tun_fops = {
1038 .owner = THIS_MODULE,
1039 .llseek = no_llseek,
1040 .read = do_sync_read,
1041 .aio_read = tun_chr_aio_read,
1042 .write = do_sync_write,
1043 .aio_write = tun_chr_aio_write,
1044 .poll = tun_chr_poll,
1045 .ioctl = tun_chr_ioctl,
1046 .open = tun_chr_open,
1047 .release = tun_chr_close,
1048 .fasync = tun_chr_fasync
1049 };
1050
1051 static struct miscdevice tun_miscdev = {
1052 .minor = TUN_MINOR,
1053 .name = "tun",
1054 .fops = &tun_fops,
1055 };
1056
1057 /* ethtool interface */
1058
1059 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1060 {
1061 cmd->supported = 0;
1062 cmd->advertising = 0;
1063 cmd->speed = SPEED_10;
1064 cmd->duplex = DUPLEX_FULL;
1065 cmd->port = PORT_TP;
1066 cmd->phy_address = 0;
1067 cmd->transceiver = XCVR_INTERNAL;
1068 cmd->autoneg = AUTONEG_DISABLE;
1069 cmd->maxtxpkt = 0;
1070 cmd->maxrxpkt = 0;
1071 return 0;
1072 }
1073
1074 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
1075 {
1076 struct tun_struct *tun = netdev_priv(dev);
1077
1078 strcpy(info->driver, DRV_NAME);
1079 strcpy(info->version, DRV_VERSION);
1080 strcpy(info->fw_version, "N/A");
1081
1082 switch (tun->flags & TUN_TYPE_MASK) {
1083 case TUN_TUN_DEV:
1084 strcpy(info->bus_info, "tun");
1085 break;
1086 case TUN_TAP_DEV:
1087 strcpy(info->bus_info, "tap");
1088 break;
1089 }
1090 }
1091
1092 static u32 tun_get_msglevel(struct net_device *dev)
1093 {
1094 #ifdef TUN_DEBUG
1095 struct tun_struct *tun = netdev_priv(dev);
1096 return tun->debug;
1097 #else
1098 return -EOPNOTSUPP;
1099 #endif
1100 }
1101
1102 static void tun_set_msglevel(struct net_device *dev, u32 value)
1103 {
1104 #ifdef TUN_DEBUG
1105 struct tun_struct *tun = netdev_priv(dev);
1106 tun->debug = value;
1107 #endif
1108 }
1109
1110 static u32 tun_get_link(struct net_device *dev)
1111 {
1112 struct tun_struct *tun = netdev_priv(dev);
1113 return tun->attached;
1114 }
1115
1116 static u32 tun_get_rx_csum(struct net_device *dev)
1117 {
1118 struct tun_struct *tun = netdev_priv(dev);
1119 return (tun->flags & TUN_NOCHECKSUM) == 0;
1120 }
1121
1122 static int tun_set_rx_csum(struct net_device *dev, u32 data)
1123 {
1124 struct tun_struct *tun = netdev_priv(dev);
1125 if (data)
1126 tun->flags &= ~TUN_NOCHECKSUM;
1127 else
1128 tun->flags |= TUN_NOCHECKSUM;
1129 return 0;
1130 }
1131
1132 static const struct ethtool_ops tun_ethtool_ops = {
1133 .get_settings = tun_get_settings,
1134 .get_drvinfo = tun_get_drvinfo,
1135 .get_msglevel = tun_get_msglevel,
1136 .set_msglevel = tun_set_msglevel,
1137 .get_link = tun_get_link,
1138 .get_rx_csum = tun_get_rx_csum,
1139 .set_rx_csum = tun_set_rx_csum
1140 };
1141
1142 static int tun_init_net(struct net *net)
1143 {
1144 struct tun_net *tn;
1145
1146 tn = kmalloc(sizeof(*tn), GFP_KERNEL);
1147 if (tn == NULL)
1148 return -ENOMEM;
1149
1150 INIT_LIST_HEAD(&tn->dev_list);
1151
1152 if (net_assign_generic(net, tun_net_id, tn)) {
1153 kfree(tn);
1154 return -ENOMEM;
1155 }
1156
1157 return 0;
1158 }
1159
1160 static void tun_exit_net(struct net *net)
1161 {
1162 struct tun_net *tn;
1163 struct tun_struct *tun, *nxt;
1164
1165 tn = net_generic(net, tun_net_id);
1166
1167 rtnl_lock();
1168 list_for_each_entry_safe(tun, nxt, &tn->dev_list, list) {
1169 DBG(KERN_INFO "%s cleaned up\n", tun->dev->name);
1170 unregister_netdevice(tun->dev);
1171 }
1172 rtnl_unlock();
1173
1174 kfree(tn);
1175 }
1176
1177 static struct pernet_operations tun_net_ops = {
1178 .init = tun_init_net,
1179 .exit = tun_exit_net,
1180 };
1181
1182 static int __init tun_init(void)
1183 {
1184 int ret = 0;
1185
1186 printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
1187 printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
1188
1189 ret = register_pernet_gen_device(&tun_net_id, &tun_net_ops);
1190 if (ret) {
1191 printk(KERN_ERR "tun: Can't register pernet ops\n");
1192 goto err_pernet;
1193 }
1194
1195 ret = misc_register(&tun_miscdev);
1196 if (ret) {
1197 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
1198 goto err_misc;
1199 }
1200 return 0;
1201
1202 err_misc:
1203 unregister_pernet_gen_device(tun_net_id, &tun_net_ops);
1204 err_pernet:
1205 return ret;
1206 }
1207
1208 static void tun_cleanup(void)
1209 {
1210 misc_deregister(&tun_miscdev);
1211 unregister_pernet_gen_device(tun_net_id, &tun_net_ops);
1212 }
1213
1214 module_init(tun_init);
1215 module_exit(tun_cleanup);
1216 MODULE_DESCRIPTION(DRV_DESCRIPTION);
1217 MODULE_AUTHOR(DRV_COPYRIGHT);
1218 MODULE_LICENSE("GPL");
1219 MODULE_ALIAS_MISCDEV(TUN_MINOR);
Linux kernel - Deliverables
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