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Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
[linux-2.6/mini2440.git] / drivers / net / tun.c
blob735bf41c654ab459a6bf556bbf6d8242b8117797
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 #include <net/rtnetlink.h>
67 #include <net/sock.h>
68
69 #include <asm/system.h>
70 #include <asm/uaccess.h>
71
72 /* Uncomment to enable debugging */
73 /* #define TUN_DEBUG 1 */
74
75 #ifdef TUN_DEBUG
76 static int debug;
77
78 #define DBG if(tun->debug)printk
79 #define DBG1 if(debug==2)printk
80 #else
81 #define DBG( a... )
82 #define DBG1( a... )
83 #endif
84
85 #define FLT_EXACT_COUNT 8
86 struct tap_filter {
87 unsigned int count; /* Number of addrs. Zero means disabled */
88 u32 mask[2]; /* Mask of the hashed addrs */
89 unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN];
90 };
91
92 struct tun_file {
93 atomic_t count;
94 struct tun_struct *tun;
95 struct net *net;
96 };
97
98 struct tun_sock;
99
100 struct tun_struct {
101 struct tun_file *tfile;
102 unsigned int flags;
103 uid_t owner;
104 gid_t group;
105
106 struct sk_buff_head readq;
107
108 struct net_device *dev;
109 struct fasync_struct *fasync;
110
111 struct tap_filter txflt;
112 struct sock *sk;
113 struct socket socket;
114
115 #ifdef TUN_DEBUG
116 int debug;
117 #endif
118 };
119
120 struct tun_sock {
121 struct sock sk;
122 struct tun_struct *tun;
123 };
124
125 static inline struct tun_sock *tun_sk(struct sock *sk)
126 {
127 return container_of(sk, struct tun_sock, sk);
128 }
129
130 static int tun_attach(struct tun_struct *tun, struct file *file)
131 {
132 struct tun_file *tfile = file->private_data;
133 const struct cred *cred = current_cred();
134 int err;
135
136 ASSERT_RTNL();
137
138 /* Check permissions */
139 if (((tun->owner != -1 && cred->euid != tun->owner) ||
140 (tun->group != -1 && !in_egroup_p(tun->group))) &&
141 !capable(CAP_NET_ADMIN))
142 return -EPERM;
143
144 netif_tx_lock_bh(tun->dev);
145
146 err = -EINVAL;
147 if (tfile->tun)
148 goto out;
149
150 err = -EBUSY;
151 if (tun->tfile)
152 goto out;
153
154 err = 0;
155 tfile->tun = tun;
156 tun->tfile = tfile;
157 dev_hold(tun->dev);
158 sock_hold(tun->sk);
159 atomic_inc(&tfile->count);
160
161 out:
162 netif_tx_unlock_bh(tun->dev);
163 return err;
164 }
165
166 static void __tun_detach(struct tun_struct *tun)
167 {
168 /* Detach from net device */
169 netif_tx_lock_bh(tun->dev);
170 tun->tfile = NULL;
171 netif_tx_unlock_bh(tun->dev);
172
173 /* Drop read queue */
174 skb_queue_purge(&tun->readq);
175
176 /* Drop the extra count on the net device */
177 dev_put(tun->dev);
178 }
179
180 static void tun_detach(struct tun_struct *tun)
181 {
182 rtnl_lock();
183 __tun_detach(tun);
184 rtnl_unlock();
185 }
186
187 static struct tun_struct *__tun_get(struct tun_file *tfile)
188 {
189 struct tun_struct *tun = NULL;
190
191 if (atomic_inc_not_zero(&tfile->count))
192 tun = tfile->tun;
193
194 return tun;
195 }
196
197 static struct tun_struct *tun_get(struct file *file)
198 {
199 return __tun_get(file->private_data);
200 }
201
202 static void tun_put(struct tun_struct *tun)
203 {
204 struct tun_file *tfile = tun->tfile;
205
206 if (atomic_dec_and_test(&tfile->count))
207 tun_detach(tfile->tun);
208 }
209
210 /* TAP filterting */
211 static void addr_hash_set(u32 *mask, const u8 *addr)
212 {
213 int n = ether_crc(ETH_ALEN, addr) >> 26;
214 mask[n >> 5] |= (1 << (n & 31));
215 }
216
217 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
218 {
219 int n = ether_crc(ETH_ALEN, addr) >> 26;
220 return mask[n >> 5] & (1 << (n & 31));
221 }
222
223 static int update_filter(struct tap_filter *filter, void __user *arg)
224 {
225 struct { u8 u[ETH_ALEN]; } *addr;
226 struct tun_filter uf;
227 int err, alen, n, nexact;
228
229 if (copy_from_user(&uf, arg, sizeof(uf)))
230 return -EFAULT;
231
232 if (!uf.count) {
233 /* Disabled */
234 filter->count = 0;
235 return 0;
236 }
237
238 alen = ETH_ALEN * uf.count;
239 addr = kmalloc(alen, GFP_KERNEL);
240 if (!addr)
241 return -ENOMEM;
242
243 if (copy_from_user(addr, arg + sizeof(uf), alen)) {
244 err = -EFAULT;
245 goto done;
246 }
247
248 /* The filter is updated without holding any locks. Which is
249 * perfectly safe. We disable it first and in the worst
250 * case we'll accept a few undesired packets. */
251 filter->count = 0;
252 wmb();
253
254 /* Use first set of addresses as an exact filter */
255 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
256 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
257
258 nexact = n;
259
260 /* Remaining multicast addresses are hashed,
261 * unicast will leave the filter disabled. */
262 memset(filter->mask, 0, sizeof(filter->mask));
263 for (; n < uf.count; n++) {
264 if (!is_multicast_ether_addr(addr[n].u)) {
265 err = 0; /* no filter */
266 goto done;
267 }
268 addr_hash_set(filter->mask, addr[n].u);
269 }
270
271 /* For ALLMULTI just set the mask to all ones.
272 * This overrides the mask populated above. */
273 if ((uf.flags & TUN_FLT_ALLMULTI))
274 memset(filter->mask, ~0, sizeof(filter->mask));
275
276 /* Now enable the filter */
277 wmb();
278 filter->count = nexact;
279
280 /* Return the number of exact filters */
281 err = nexact;
282
283 done:
284 kfree(addr);
285 return err;
286 }
287
288 /* Returns: 0 - drop, !=0 - accept */
289 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
290 {
291 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
292 * at this point. */
293 struct ethhdr *eh = (struct ethhdr *) skb->data;
294 int i;
295
296 /* Exact match */
297 for (i = 0; i < filter->count; i++)
298 if (!compare_ether_addr(eh->h_dest, filter->addr[i]))
299 return 1;
300
301 /* Inexact match (multicast only) */
302 if (is_multicast_ether_addr(eh->h_dest))
303 return addr_hash_test(filter->mask, eh->h_dest);
304
305 return 0;
306 }
307
308 /*
309 * Checks whether the packet is accepted or not.
310 * Returns: 0 - drop, !=0 - accept
311 */
312 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
313 {
314 if (!filter->count)
315 return 1;
316
317 return run_filter(filter, skb);
318 }
319
320 /* Network device part of the driver */
321
322 static const struct ethtool_ops tun_ethtool_ops;
323
324 /* Net device detach from fd. */
325 static void tun_net_uninit(struct net_device *dev)
326 {
327 struct tun_struct *tun = netdev_priv(dev);
328 struct tun_file *tfile = tun->tfile;
329
330 /* Inform the methods they need to stop using the dev.
331 */
332 if (tfile) {
333 wake_up_all(&tun->socket.wait);
334 if (atomic_dec_and_test(&tfile->count))
335 __tun_detach(tun);
336 }
337 }
338
339 static void tun_free_netdev(struct net_device *dev)
340 {
341 struct tun_struct *tun = netdev_priv(dev);
342
343 sock_put(tun->sk);
344 }
345
346 /* Net device open. */
347 static int tun_net_open(struct net_device *dev)
348 {
349 netif_start_queue(dev);
350 return 0;
351 }
352
353 /* Net device close. */
354 static int tun_net_close(struct net_device *dev)
355 {
356 netif_stop_queue(dev);
357 return 0;
358 }
359
360 /* Net device start xmit */
361 static int tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
362 {
363 struct tun_struct *tun = netdev_priv(dev);
364
365 DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len);
366
367 /* Drop packet if interface is not attached */
368 if (!tun->tfile)
369 goto drop;
370
371 /* Drop if the filter does not like it.
372 * This is a noop if the filter is disabled.
373 * Filter can be enabled only for the TAP devices. */
374 if (!check_filter(&tun->txflt, skb))
375 goto drop;
376
377 if (skb_queue_len(&tun->readq) >= dev->tx_queue_len) {
378 if (!(tun->flags & TUN_ONE_QUEUE)) {
379 /* Normal queueing mode. */
380 /* Packet scheduler handles dropping of further packets. */
381 netif_stop_queue(dev);
382
383 /* We won't see all dropped packets individually, so overrun
384 * error is more appropriate. */
385 dev->stats.tx_fifo_errors++;
386 } else {
387 /* Single queue mode.
388 * Driver handles dropping of all packets itself. */
389 goto drop;
390 }
391 }
392
393 /* Enqueue packet */
394 skb_queue_tail(&tun->readq, skb);
395 dev->trans_start = jiffies;
396
397 /* Notify and wake up reader process */
398 if (tun->flags & TUN_FASYNC)
399 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
400 wake_up_interruptible(&tun->socket.wait);
401 return 0;
402
403 drop:
404 dev->stats.tx_dropped++;
405 kfree_skb(skb);
406 return 0;
407 }
408
409 static void tun_net_mclist(struct net_device *dev)
410 {
411 /*
412 * This callback is supposed to deal with mc filter in
413 * _rx_ path and has nothing to do with the _tx_ path.
414 * In rx path we always accept everything userspace gives us.
415 */
416 return;
417 }
418
419 #define MIN_MTU 68
420 #define MAX_MTU 65535
421
422 static int
423 tun_net_change_mtu(struct net_device *dev, int new_mtu)
424 {
425 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
426 return -EINVAL;
427 dev->mtu = new_mtu;
428 return 0;
429 }
430
431 static const struct net_device_ops tun_netdev_ops = {
432 .ndo_uninit = tun_net_uninit,
433 .ndo_open = tun_net_open,
434 .ndo_stop = tun_net_close,
435 .ndo_start_xmit = tun_net_xmit,
436 .ndo_change_mtu = tun_net_change_mtu,
437 };
438
439 static const struct net_device_ops tap_netdev_ops = {
440 .ndo_uninit = tun_net_uninit,
441 .ndo_open = tun_net_open,
442 .ndo_stop = tun_net_close,
443 .ndo_start_xmit = tun_net_xmit,
444 .ndo_change_mtu = tun_net_change_mtu,
445 .ndo_set_multicast_list = tun_net_mclist,
446 .ndo_set_mac_address = eth_mac_addr,
447 .ndo_validate_addr = eth_validate_addr,
448 };
449
450 /* Initialize net device. */
451 static void tun_net_init(struct net_device *dev)
452 {
453 struct tun_struct *tun = netdev_priv(dev);
454
455 switch (tun->flags & TUN_TYPE_MASK) {
456 case TUN_TUN_DEV:
457 dev->netdev_ops = &tun_netdev_ops;
458
459 /* Point-to-Point TUN Device */
460 dev->hard_header_len = 0;
461 dev->addr_len = 0;
462 dev->mtu = 1500;
463
464 /* Zero header length */
465 dev->type = ARPHRD_NONE;
466 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
467 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
468 break;
469
470 case TUN_TAP_DEV:
471 dev->netdev_ops = &tap_netdev_ops;
472 /* Ethernet TAP Device */
473 ether_setup(dev);
474
475 random_ether_addr(dev->dev_addr);
476
477 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
478 break;
479 }
480 }
481
482 /* Character device part */
483
484 /* Poll */
485 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
486 {
487 struct tun_file *tfile = file->private_data;
488 struct tun_struct *tun = __tun_get(tfile);
489 struct sock *sk = tun->sk;
490 unsigned int mask = 0;
491
492 if (!tun)
493 return POLLERR;
494
495 DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
496
497 poll_wait(file, &tun->socket.wait, wait);
498
499 if (!skb_queue_empty(&tun->readq))
500 mask |= POLLIN | POLLRDNORM;
501
502 if (sock_writeable(sk) ||
503 (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
504 sock_writeable(sk)))
505 mask |= POLLOUT | POLLWRNORM;
506
507 if (tun->dev->reg_state != NETREG_REGISTERED)
508 mask = POLLERR;
509
510 tun_put(tun);
511 return mask;
512 }
513
514 /* prepad is the amount to reserve at front. len is length after that.
515 * linear is a hint as to how much to copy (usually headers). */
516 static inline struct sk_buff *tun_alloc_skb(struct tun_struct *tun,
517 size_t prepad, size_t len,
518 size_t linear, int noblock)
519 {
520 struct sock *sk = tun->sk;
521 struct sk_buff *skb;
522 int err;
523
524 /* Under a page? Don't bother with paged skb. */
525 if (prepad + len < PAGE_SIZE || !linear)
526 linear = len;
527
528 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
529 &err);
530 if (!skb)
531 return ERR_PTR(err);
532
533 skb_reserve(skb, prepad);
534 skb_put(skb, linear);
535 skb->data_len = len - linear;
536 skb->len += len - linear;
537
538 return skb;
539 }
540
541 /* Get packet from user space buffer */
542 static __inline__ ssize_t tun_get_user(struct tun_struct *tun,
543 struct iovec *iv, size_t count,
544 int noblock)
545 {
546 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
547 struct sk_buff *skb;
548 size_t len = count, align = 0;
549 struct virtio_net_hdr gso = { 0 };
550
551 if (!(tun->flags & TUN_NO_PI)) {
552 if ((len -= sizeof(pi)) > count)
553 return -EINVAL;
554
555 if(memcpy_fromiovec((void *)&pi, iv, sizeof(pi)))
556 return -EFAULT;
557 }
558
559 if (tun->flags & TUN_VNET_HDR) {
560 if ((len -= sizeof(gso)) > count)
561 return -EINVAL;
562
563 if (memcpy_fromiovec((void *)&gso, iv, sizeof(gso)))
564 return -EFAULT;
565
566 if (gso.hdr_len > len)
567 return -EINVAL;
568 }
569
570 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
571 align = NET_IP_ALIGN;
572 if (unlikely(len < ETH_HLEN ||
573 (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
574 return -EINVAL;
575 }
576
577 skb = tun_alloc_skb(tun, align, len, gso.hdr_len, noblock);
578 if (IS_ERR(skb)) {
579 if (PTR_ERR(skb) != -EAGAIN)
580 tun->dev->stats.rx_dropped++;
581 return PTR_ERR(skb);
582 }
583
584 if (skb_copy_datagram_from_iovec(skb, 0, iv, len)) {
585 tun->dev->stats.rx_dropped++;
586 kfree_skb(skb);
587 return -EFAULT;
588 }
589
590 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
591 if (!skb_partial_csum_set(skb, gso.csum_start,
592 gso.csum_offset)) {
593 tun->dev->stats.rx_frame_errors++;
594 kfree_skb(skb);
595 return -EINVAL;
596 }
597 } else if (tun->flags & TUN_NOCHECKSUM)
598 skb->ip_summed = CHECKSUM_UNNECESSARY;
599
600 switch (tun->flags & TUN_TYPE_MASK) {
601 case TUN_TUN_DEV:
602 if (tun->flags & TUN_NO_PI) {
603 switch (skb->data[0] & 0xf0) {
604 case 0x40:
605 pi.proto = htons(ETH_P_IP);
606 break;
607 case 0x60:
608 pi.proto = htons(ETH_P_IPV6);
609 break;
610 default:
611 tun->dev->stats.rx_dropped++;
612 kfree_skb(skb);
613 return -EINVAL;
614 }
615 }
616
617 skb_reset_mac_header(skb);
618 skb->protocol = pi.proto;
619 skb->dev = tun->dev;
620 break;
621 case TUN_TAP_DEV:
622 skb->protocol = eth_type_trans(skb, tun->dev);
623 break;
624 };
625
626 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
627 pr_debug("GSO!\n");
628 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
629 case VIRTIO_NET_HDR_GSO_TCPV4:
630 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
631 break;
632 case VIRTIO_NET_HDR_GSO_TCPV6:
633 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
634 break;
635 default:
636 tun->dev->stats.rx_frame_errors++;
637 kfree_skb(skb);
638 return -EINVAL;
639 }
640
641 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
642 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
643
644 skb_shinfo(skb)->gso_size = gso.gso_size;
645 if (skb_shinfo(skb)->gso_size == 0) {
646 tun->dev->stats.rx_frame_errors++;
647 kfree_skb(skb);
648 return -EINVAL;
649 }
650
651 /* Header must be checked, and gso_segs computed. */
652 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
653 skb_shinfo(skb)->gso_segs = 0;
654 }
655
656 netif_rx_ni(skb);
657
658 tun->dev->stats.rx_packets++;
659 tun->dev->stats.rx_bytes += len;
660
661 return count;
662 }
663
664 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
665 unsigned long count, loff_t pos)
666 {
667 struct file *file = iocb->ki_filp;
668 struct tun_struct *tun = tun_get(file);
669 ssize_t result;
670
671 if (!tun)
672 return -EBADFD;
673
674 DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
675
676 result = tun_get_user(tun, (struct iovec *)iv, iov_length(iv, count),
677 file->f_flags & O_NONBLOCK);
678
679 tun_put(tun);
680 return result;
681 }
682
683 /* Put packet to the user space buffer */
684 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
685 struct sk_buff *skb,
686 struct iovec *iv, int len)
687 {
688 struct tun_pi pi = { 0, skb->protocol };
689 ssize_t total = 0;
690
691 if (!(tun->flags & TUN_NO_PI)) {
692 if ((len -= sizeof(pi)) < 0)
693 return -EINVAL;
694
695 if (len < skb->len) {
696 /* Packet will be striped */
697 pi.flags |= TUN_PKT_STRIP;
698 }
699
700 if (memcpy_toiovec(iv, (void *) &pi, sizeof(pi)))
701 return -EFAULT;
702 total += sizeof(pi);
703 }
704
705 if (tun->flags & TUN_VNET_HDR) {
706 struct virtio_net_hdr gso = { 0 }; /* no info leak */
707 if ((len -= sizeof(gso)) < 0)
708 return -EINVAL;
709
710 if (skb_is_gso(skb)) {
711 struct skb_shared_info *sinfo = skb_shinfo(skb);
712
713 /* This is a hint as to how much should be linear. */
714 gso.hdr_len = skb_headlen(skb);
715 gso.gso_size = sinfo->gso_size;
716 if (sinfo->gso_type & SKB_GSO_TCPV4)
717 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
718 else if (sinfo->gso_type & SKB_GSO_TCPV6)
719 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
720 else
721 BUG();
722 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
723 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
724 } else
725 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
726
727 if (skb->ip_summed == CHECKSUM_PARTIAL) {
728 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
729 gso.csum_start = skb->csum_start - skb_headroom(skb);
730 gso.csum_offset = skb->csum_offset;
731 } /* else everything is zero */
732
733 if (unlikely(memcpy_toiovec(iv, (void *)&gso, sizeof(gso))))
734 return -EFAULT;
735 total += sizeof(gso);
736 }
737
738 len = min_t(int, skb->len, len);
739
740 skb_copy_datagram_iovec(skb, 0, iv, len);
741 total += len;
742
743 tun->dev->stats.tx_packets++;
744 tun->dev->stats.tx_bytes += len;
745
746 return total;
747 }
748
749 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
750 unsigned long count, loff_t pos)
751 {
752 struct file *file = iocb->ki_filp;
753 struct tun_file *tfile = file->private_data;
754 struct tun_struct *tun = __tun_get(tfile);
755 DECLARE_WAITQUEUE(wait, current);
756 struct sk_buff *skb;
757 ssize_t len, ret = 0;
758
759 if (!tun)
760 return -EBADFD;
761
762 DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
763
764 len = iov_length(iv, count);
765 if (len < 0) {
766 ret = -EINVAL;
767 goto out;
768 }
769
770 add_wait_queue(&tun->socket.wait, &wait);
771 while (len) {
772 current->state = TASK_INTERRUPTIBLE;
773
774 /* Read frames from the queue */
775 if (!(skb=skb_dequeue(&tun->readq))) {
776 if (file->f_flags & O_NONBLOCK) {
777 ret = -EAGAIN;
778 break;
779 }
780 if (signal_pending(current)) {
781 ret = -ERESTARTSYS;
782 break;
783 }
784 if (tun->dev->reg_state != NETREG_REGISTERED) {
785 ret = -EIO;
786 break;
787 }
788
789 /* Nothing to read, let's sleep */
790 schedule();
791 continue;
792 }
793 netif_wake_queue(tun->dev);
794
795 ret = tun_put_user(tun, skb, (struct iovec *) iv, len);
796 kfree_skb(skb);
797 break;
798 }
799
800 current->state = TASK_RUNNING;
801 remove_wait_queue(&tun->socket.wait, &wait);
802
803 out:
804 tun_put(tun);
805 return ret;
806 }
807
808 static void tun_setup(struct net_device *dev)
809 {
810 struct tun_struct *tun = netdev_priv(dev);
811
812 skb_queue_head_init(&tun->readq);
813
814 tun->owner = -1;
815 tun->group = -1;
816
817 dev->ethtool_ops = &tun_ethtool_ops;
818 dev->destructor = tun_free_netdev;
819 }
820
821 /* Trivial set of netlink ops to allow deleting tun or tap
822 * device with netlink.
823 */
824 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
825 {
826 return -EINVAL;
827 }
828
829 static struct rtnl_link_ops tun_link_ops __read_mostly = {
830 .kind = DRV_NAME,
831 .priv_size = sizeof(struct tun_struct),
832 .setup = tun_setup,
833 .validate = tun_validate,
834 };
835
836 static void tun_sock_write_space(struct sock *sk)
837 {
838 struct tun_struct *tun;
839
840 if (!sock_writeable(sk))
841 return;
842
843 if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
844 wake_up_interruptible_sync(sk->sk_sleep);
845
846 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
847 return;
848
849 tun = container_of(sk, struct tun_sock, sk)->tun;
850 kill_fasync(&tun->fasync, SIGIO, POLL_OUT);
851 }
852
853 static void tun_sock_destruct(struct sock *sk)
854 {
855 free_netdev(container_of(sk, struct tun_sock, sk)->tun->dev);
856 }
857
858 static struct proto tun_proto = {
859 .name = "tun",
860 .owner = THIS_MODULE,
861 .obj_size = sizeof(struct tun_sock),
862 };
863
864 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
865 {
866 struct sock *sk;
867 struct tun_struct *tun;
868 struct net_device *dev;
869 int err;
870
871 dev = __dev_get_by_name(net, ifr->ifr_name);
872 if (dev) {
873 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
874 tun = netdev_priv(dev);
875 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
876 tun = netdev_priv(dev);
877 else
878 return -EINVAL;
879
880 err = tun_attach(tun, file);
881 if (err < 0)
882 return err;
883 }
884 else {
885 char *name;
886 unsigned long flags = 0;
887
888 err = -EINVAL;
889
890 if (!capable(CAP_NET_ADMIN))
891 return -EPERM;
892
893 /* Set dev type */
894 if (ifr->ifr_flags & IFF_TUN) {
895 /* TUN device */
896 flags |= TUN_TUN_DEV;
897 name = "tun%d";
898 } else if (ifr->ifr_flags & IFF_TAP) {
899 /* TAP device */
900 flags |= TUN_TAP_DEV;
901 name = "tap%d";
902 } else
903 goto failed;
904
905 if (*ifr->ifr_name)
906 name = ifr->ifr_name;
907
908 dev = alloc_netdev(sizeof(struct tun_struct), name,
909 tun_setup);
910 if (!dev)
911 return -ENOMEM;
912
913 dev_net_set(dev, net);
914 dev->rtnl_link_ops = &tun_link_ops;
915
916 tun = netdev_priv(dev);
917 tun->dev = dev;
918 tun->flags = flags;
919 tun->txflt.count = 0;
920
921 err = -ENOMEM;
922 sk = sk_alloc(net, AF_UNSPEC, GFP_KERNEL, &tun_proto);
923 if (!sk)
924 goto err_free_dev;
925
926 init_waitqueue_head(&tun->socket.wait);
927 sock_init_data(&tun->socket, sk);
928 sk->sk_write_space = tun_sock_write_space;
929 sk->sk_sndbuf = INT_MAX;
930
931 tun->sk = sk;
932 container_of(sk, struct tun_sock, sk)->tun = tun;
933
934 tun_net_init(dev);
935
936 if (strchr(dev->name, '%')) {
937 err = dev_alloc_name(dev, dev->name);
938 if (err < 0)
939 goto err_free_sk;
940 }
941
942 err = -EINVAL;
943 err = register_netdevice(tun->dev);
944 if (err < 0)
945 goto err_free_sk;
946
947 sk->sk_destruct = tun_sock_destruct;
948
949 err = tun_attach(tun, file);
950 if (err < 0)
951 goto failed;
952 }
953
954 DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
955
956 if (ifr->ifr_flags & IFF_NO_PI)
957 tun->flags |= TUN_NO_PI;
958 else
959 tun->flags &= ~TUN_NO_PI;
960
961 if (ifr->ifr_flags & IFF_ONE_QUEUE)
962 tun->flags |= TUN_ONE_QUEUE;
963 else
964 tun->flags &= ~TUN_ONE_QUEUE;
965
966 if (ifr->ifr_flags & IFF_VNET_HDR)
967 tun->flags |= TUN_VNET_HDR;
968 else
969 tun->flags &= ~TUN_VNET_HDR;
970
971 /* Make sure persistent devices do not get stuck in
972 * xoff state.
973 */
974 if (netif_running(tun->dev))
975 netif_wake_queue(tun->dev);
976
977 strcpy(ifr->ifr_name, tun->dev->name);
978 return 0;
979
980 err_free_sk:
981 sock_put(sk);
982 err_free_dev:
983 free_netdev(dev);
984 failed:
985 return err;
986 }
987
988 static int tun_get_iff(struct net *net, struct file *file, struct ifreq *ifr)
989 {
990 struct tun_struct *tun = tun_get(file);
991
992 if (!tun)
993 return -EBADFD;
994
995 DBG(KERN_INFO "%s: tun_get_iff\n", tun->dev->name);
996
997 strcpy(ifr->ifr_name, tun->dev->name);
998
999 ifr->ifr_flags = 0;
1000
1001 if (ifr->ifr_flags & TUN_TUN_DEV)
1002 ifr->ifr_flags |= IFF_TUN;
1003 else
1004 ifr->ifr_flags |= IFF_TAP;
1005
1006 if (tun->flags & TUN_NO_PI)
1007 ifr->ifr_flags |= IFF_NO_PI;
1008
1009 if (tun->flags & TUN_ONE_QUEUE)
1010 ifr->ifr_flags |= IFF_ONE_QUEUE;
1011
1012 if (tun->flags & TUN_VNET_HDR)
1013 ifr->ifr_flags |= IFF_VNET_HDR;
1014
1015 tun_put(tun);
1016 return 0;
1017 }
1018
1019 /* This is like a cut-down ethtool ops, except done via tun fd so no
1020 * privs required. */
1021 static int set_offload(struct net_device *dev, unsigned long arg)
1022 {
1023 unsigned int old_features, features;
1024
1025 old_features = dev->features;
1026 /* Unset features, set them as we chew on the arg. */
1027 features = (old_features & ~(NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST
1028 |NETIF_F_TSO_ECN|NETIF_F_TSO|NETIF_F_TSO6));
1029
1030 if (arg & TUN_F_CSUM) {
1031 features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1032 arg &= ~TUN_F_CSUM;
1033
1034 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1035 if (arg & TUN_F_TSO_ECN) {
1036 features |= NETIF_F_TSO_ECN;
1037 arg &= ~TUN_F_TSO_ECN;
1038 }
1039 if (arg & TUN_F_TSO4)
1040 features |= NETIF_F_TSO;
1041 if (arg & TUN_F_TSO6)
1042 features |= NETIF_F_TSO6;
1043 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1044 }
1045 }
1046
1047 /* This gives the user a way to test for new features in future by
1048 * trying to set them. */
1049 if (arg)
1050 return -EINVAL;
1051
1052 dev->features = features;
1053 if (old_features != dev->features)
1054 netdev_features_change(dev);
1055
1056 return 0;
1057 }
1058
1059 static int tun_chr_ioctl(struct inode *inode, struct file *file,
1060 unsigned int cmd, unsigned long arg)
1061 {
1062 struct tun_file *tfile = file->private_data;
1063 struct tun_struct *tun;
1064 void __user* argp = (void __user*)arg;
1065 struct ifreq ifr;
1066 int sndbuf;
1067 int ret;
1068
1069 if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
1070 if (copy_from_user(&ifr, argp, sizeof ifr))
1071 return -EFAULT;
1072
1073 if (cmd == TUNGETFEATURES) {
1074 /* Currently this just means: "what IFF flags are valid?".
1075 * This is needed because we never checked for invalid flags on
1076 * TUNSETIFF. */
1077 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
1078 IFF_VNET_HDR,
1079 (unsigned int __user*)argp);
1080 }
1081
1082 tun = __tun_get(tfile);
1083 if (cmd == TUNSETIFF && !tun) {
1084 int err;
1085
1086 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1087
1088 rtnl_lock();
1089 err = tun_set_iff(tfile->net, file, &ifr);
1090 rtnl_unlock();
1091
1092 if (err)
1093 return err;
1094
1095 if (copy_to_user(argp, &ifr, sizeof(ifr)))
1096 return -EFAULT;
1097 return 0;
1098 }
1099
1100
1101 if (!tun)
1102 return -EBADFD;
1103
1104 DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
1105
1106 ret = 0;
1107 switch (cmd) {
1108 case TUNGETIFF:
1109 ret = tun_get_iff(current->nsproxy->net_ns, file, &ifr);
1110 if (ret)
1111 break;
1112
1113 if (copy_to_user(argp, &ifr, sizeof(ifr)))
1114 ret = -EFAULT;
1115 break;
1116
1117 case TUNSETNOCSUM:
1118 /* Disable/Enable checksum */
1119 if (arg)
1120 tun->flags |= TUN_NOCHECKSUM;
1121 else
1122 tun->flags &= ~TUN_NOCHECKSUM;
1123
1124 DBG(KERN_INFO "%s: checksum %s\n",
1125 tun->dev->name, arg ? "disabled" : "enabled");
1126 break;
1127
1128 case TUNSETPERSIST:
1129 /* Disable/Enable persist mode */
1130 if (arg)
1131 tun->flags |= TUN_PERSIST;
1132 else
1133 tun->flags &= ~TUN_PERSIST;
1134
1135 DBG(KERN_INFO "%s: persist %s\n",
1136 tun->dev->name, arg ? "enabled" : "disabled");
1137 break;
1138
1139 case TUNSETOWNER:
1140 /* Set owner of the device */
1141 tun->owner = (uid_t) arg;
1142
1143 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
1144 break;
1145
1146 case TUNSETGROUP:
1147 /* Set group of the device */
1148 tun->group= (gid_t) arg;
1149
1150 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group);
1151 break;
1152
1153 case TUNSETLINK:
1154 /* Only allow setting the type when the interface is down */
1155 rtnl_lock();
1156 if (tun->dev->flags & IFF_UP) {
1157 DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
1158 tun->dev->name);
1159 ret = -EBUSY;
1160 } else {
1161 tun->dev->type = (int) arg;
1162 DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
1163 ret = 0;
1164 }
1165 rtnl_unlock();
1166 break;
1167
1168 #ifdef TUN_DEBUG
1169 case TUNSETDEBUG:
1170 tun->debug = arg;
1171 break;
1172 #endif
1173 case TUNSETOFFLOAD:
1174 rtnl_lock();
1175 ret = set_offload(tun->dev, arg);
1176 rtnl_unlock();
1177 break;
1178
1179 case TUNSETTXFILTER:
1180 /* Can be set only for TAPs */
1181 ret = -EINVAL;
1182 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1183 break;
1184 rtnl_lock();
1185 ret = update_filter(&tun->txflt, (void __user *)arg);
1186 rtnl_unlock();
1187 break;
1188
1189 case SIOCGIFHWADDR:
1190 /* Get hw addres */
1191 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
1192 ifr.ifr_hwaddr.sa_family = tun->dev->type;
1193 if (copy_to_user(argp, &ifr, sizeof ifr))
1194 ret = -EFAULT;
1195 break;
1196
1197 case SIOCSIFHWADDR:
1198 /* Set hw address */
1199 DBG(KERN_DEBUG "%s: set hw address: %pM\n",
1200 tun->dev->name, ifr.ifr_hwaddr.sa_data);
1201
1202 rtnl_lock();
1203 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
1204 rtnl_unlock();
1205 break;
1206
1207 case TUNGETSNDBUF:
1208 sndbuf = tun->sk->sk_sndbuf;
1209 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
1210 ret = -EFAULT;
1211 break;
1212
1213 case TUNSETSNDBUF:
1214 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
1215 ret = -EFAULT;
1216 break;
1217 }
1218
1219 tun->sk->sk_sndbuf = sndbuf;
1220 break;
1221
1222 default:
1223 ret = -EINVAL;
1224 break;
1225 };
1226
1227 tun_put(tun);
1228 return ret;
1229 }
1230
1231 static int tun_chr_fasync(int fd, struct file *file, int on)
1232 {
1233 struct tun_struct *tun = tun_get(file);
1234 int ret;
1235
1236 if (!tun)
1237 return -EBADFD;
1238
1239 DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
1240
1241 lock_kernel();
1242 if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
1243 goto out;
1244
1245 if (on) {
1246 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
1247 if (ret)
1248 goto out;
1249 tun->flags |= TUN_FASYNC;
1250 } else
1251 tun->flags &= ~TUN_FASYNC;
1252 ret = 0;
1253 out:
1254 unlock_kernel();
1255 tun_put(tun);
1256 return ret;
1257 }
1258
1259 static int tun_chr_open(struct inode *inode, struct file * file)
1260 {
1261 struct tun_file *tfile;
1262 cycle_kernel_lock();
1263 DBG1(KERN_INFO "tunX: tun_chr_open\n");
1264
1265 tfile = kmalloc(sizeof(*tfile), GFP_KERNEL);
1266 if (!tfile)
1267 return -ENOMEM;
1268 atomic_set(&tfile->count, 0);
1269 tfile->tun = NULL;
1270 tfile->net = get_net(current->nsproxy->net_ns);
1271 file->private_data = tfile;
1272 return 0;
1273 }
1274
1275 static int tun_chr_close(struct inode *inode, struct file *file)
1276 {
1277 struct tun_file *tfile = file->private_data;
1278 struct tun_struct *tun = __tun_get(tfile);
1279
1280
1281 if (tun) {
1282 DBG(KERN_INFO "%s: tun_chr_close\n", tun->dev->name);
1283
1284 rtnl_lock();
1285 __tun_detach(tun);
1286
1287 /* If desireable, unregister the netdevice. */
1288 if (!(tun->flags & TUN_PERSIST))
1289 unregister_netdevice(tun->dev);
1290
1291 rtnl_unlock();
1292 }
1293
1294 tun = tfile->tun;
1295 if (tun)
1296 sock_put(tun->sk);
1297
1298 put_net(tfile->net);
1299 kfree(tfile);
1300
1301 return 0;
1302 }
1303
1304 static const struct file_operations tun_fops = {
1305 .owner = THIS_MODULE,
1306 .llseek = no_llseek,
1307 .read = do_sync_read,
1308 .aio_read = tun_chr_aio_read,
1309 .write = do_sync_write,
1310 .aio_write = tun_chr_aio_write,
1311 .poll = tun_chr_poll,
1312 .ioctl = tun_chr_ioctl,
1313 .open = tun_chr_open,
1314 .release = tun_chr_close,
1315 .fasync = tun_chr_fasync
1316 };
1317
1318 static struct miscdevice tun_miscdev = {
1319 .minor = TUN_MINOR,
1320 .name = "tun",
1321 .fops = &tun_fops,
1322 };
1323
1324 /* ethtool interface */
1325
1326 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1327 {
1328 cmd->supported = 0;
1329 cmd->advertising = 0;
1330 cmd->speed = SPEED_10;
1331 cmd->duplex = DUPLEX_FULL;
1332 cmd->port = PORT_TP;
1333 cmd->phy_address = 0;
1334 cmd->transceiver = XCVR_INTERNAL;
1335 cmd->autoneg = AUTONEG_DISABLE;
1336 cmd->maxtxpkt = 0;
1337 cmd->maxrxpkt = 0;
1338 return 0;
1339 }
1340
1341 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
1342 {
1343 struct tun_struct *tun = netdev_priv(dev);
1344
1345 strcpy(info->driver, DRV_NAME);
1346 strcpy(info->version, DRV_VERSION);
1347 strcpy(info->fw_version, "N/A");
1348
1349 switch (tun->flags & TUN_TYPE_MASK) {
1350 case TUN_TUN_DEV:
1351 strcpy(info->bus_info, "tun");
1352 break;
1353 case TUN_TAP_DEV:
1354 strcpy(info->bus_info, "tap");
1355 break;
1356 }
1357 }
1358
1359 static u32 tun_get_msglevel(struct net_device *dev)
1360 {
1361 #ifdef TUN_DEBUG
1362 struct tun_struct *tun = netdev_priv(dev);
1363 return tun->debug;
1364 #else
1365 return -EOPNOTSUPP;
1366 #endif
1367 }
1368
1369 static void tun_set_msglevel(struct net_device *dev, u32 value)
1370 {
1371 #ifdef TUN_DEBUG
1372 struct tun_struct *tun = netdev_priv(dev);
1373 tun->debug = value;
1374 #endif
1375 }
1376
1377 static u32 tun_get_link(struct net_device *dev)
1378 {
1379 struct tun_struct *tun = netdev_priv(dev);
1380 return !!tun->tfile;
1381 }
1382
1383 static u32 tun_get_rx_csum(struct net_device *dev)
1384 {
1385 struct tun_struct *tun = netdev_priv(dev);
1386 return (tun->flags & TUN_NOCHECKSUM) == 0;
1387 }
1388
1389 static int tun_set_rx_csum(struct net_device *dev, u32 data)
1390 {
1391 struct tun_struct *tun = netdev_priv(dev);
1392 if (data)
1393 tun->flags &= ~TUN_NOCHECKSUM;
1394 else
1395 tun->flags |= TUN_NOCHECKSUM;
1396 return 0;
1397 }
1398
1399 static const struct ethtool_ops tun_ethtool_ops = {
1400 .get_settings = tun_get_settings,
1401 .get_drvinfo = tun_get_drvinfo,
1402 .get_msglevel = tun_get_msglevel,
1403 .set_msglevel = tun_set_msglevel,
1404 .get_link = tun_get_link,
1405 .get_rx_csum = tun_get_rx_csum,
1406 .set_rx_csum = tun_set_rx_csum
1407 };
1408
1409
1410 static int __init tun_init(void)
1411 {
1412 int ret = 0;
1413
1414 printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
1415 printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
1416
1417 ret = rtnl_link_register(&tun_link_ops);
1418 if (ret) {
1419 printk(KERN_ERR "tun: Can't register link_ops\n");
1420 goto err_linkops;
1421 }
1422
1423 ret = misc_register(&tun_miscdev);
1424 if (ret) {
1425 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
1426 goto err_misc;
1427 }
1428 return 0;
1429 err_misc:
1430 rtnl_link_unregister(&tun_link_ops);
1431 err_linkops:
1432 return ret;
1433 }
1434
1435 static void tun_cleanup(void)
1436 {
1437 misc_deregister(&tun_miscdev);
1438 rtnl_link_unregister(&tun_link_ops);
1439 }
1440
1441 module_init(tun_init);
1442 module_exit(tun_cleanup);
1443 MODULE_DESCRIPTION(DRV_DESCRIPTION);
1444 MODULE_AUTHOR(DRV_COPYRIGHT);
1445 MODULE_LICENSE("GPL");
1446 MODULE_ALIAS_MISCDEV(TUN_MINOR);
Support for the Chinese Samsung S3C2440 based development boards