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tun: Check supplemental groups in TUN/TAP driver.
[linux-2.6/mini2440.git] / drivers / net / tun.c
blob15d67635bb10540ee1185818aaa2b83c86bbee5b
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
68 #include <asm/system.h>
69 #include <asm/uaccess.h>
70
71 /* Uncomment to enable debugging */
72 /* #define TUN_DEBUG 1 */
73
74 #ifdef TUN_DEBUG
75 static int debug;
76
77 #define DBG if(tun->debug)printk
78 #define DBG1 if(debug==2)printk
79 #else
80 #define DBG( a... )
81 #define DBG1( a... )
82 #endif
83
84 #define FLT_EXACT_COUNT 8
85 struct tap_filter {
86 unsigned int count; /* Number of addrs. Zero means disabled */
87 u32 mask[2]; /* Mask of the hashed addrs */
88 unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN];
89 };
90
91 struct tun_file {
92 atomic_t count;
93 struct tun_struct *tun;
94 struct net *net;
95 wait_queue_head_t read_wait;
96 };
97
98 struct tun_struct {
99 struct tun_file *tfile;
100 unsigned int flags;
101 uid_t owner;
102 gid_t group;
103
104 struct sk_buff_head readq;
105
106 struct net_device *dev;
107 struct fasync_struct *fasync;
108
109 struct tap_filter txflt;
110
111 #ifdef TUN_DEBUG
112 int debug;
113 #endif
114 };
115
116 static int tun_attach(struct tun_struct *tun, struct file *file)
117 {
118 struct tun_file *tfile = file->private_data;
119 const struct cred *cred = current_cred();
120 int err;
121
122 ASSERT_RTNL();
123
124 /* Check permissions */
125 if (((tun->owner != -1 && cred->euid != tun->owner) ||
126 (tun->group != -1 && !in_egroup_p(tun->group))) &&
127 !capable(CAP_NET_ADMIN))
128 return -EPERM;
129
130 netif_tx_lock_bh(tun->dev);
131
132 err = -EINVAL;
133 if (tfile->tun)
134 goto out;
135
136 err = -EBUSY;
137 if (tun->tfile)
138 goto out;
139
140 err = 0;
141 tfile->tun = tun;
142 tun->tfile = tfile;
143 dev_hold(tun->dev);
144 atomic_inc(&tfile->count);
145
146 out:
147 netif_tx_unlock_bh(tun->dev);
148 return err;
149 }
150
151 static void __tun_detach(struct tun_struct *tun)
152 {
153 struct tun_file *tfile = tun->tfile;
154
155 /* Detach from net device */
156 netif_tx_lock_bh(tun->dev);
157 tfile->tun = NULL;
158 tun->tfile = NULL;
159 netif_tx_unlock_bh(tun->dev);
160
161 /* Drop read queue */
162 skb_queue_purge(&tun->readq);
163
164 /* Drop the extra count on the net device */
165 dev_put(tun->dev);
166 }
167
168 static void tun_detach(struct tun_struct *tun)
169 {
170 rtnl_lock();
171 __tun_detach(tun);
172 rtnl_unlock();
173 }
174
175 static struct tun_struct *__tun_get(struct tun_file *tfile)
176 {
177 struct tun_struct *tun = NULL;
178
179 if (atomic_inc_not_zero(&tfile->count))
180 tun = tfile->tun;
181
182 return tun;
183 }
184
185 static struct tun_struct *tun_get(struct file *file)
186 {
187 return __tun_get(file->private_data);
188 }
189
190 static void tun_put(struct tun_struct *tun)
191 {
192 struct tun_file *tfile = tun->tfile;
193
194 if (atomic_dec_and_test(&tfile->count))
195 tun_detach(tfile->tun);
196 }
197
198 /* TAP filterting */
199 static void addr_hash_set(u32 *mask, const u8 *addr)
200 {
201 int n = ether_crc(ETH_ALEN, addr) >> 26;
202 mask[n >> 5] |= (1 << (n & 31));
203 }
204
205 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
206 {
207 int n = ether_crc(ETH_ALEN, addr) >> 26;
208 return mask[n >> 5] & (1 << (n & 31));
209 }
210
211 static int update_filter(struct tap_filter *filter, void __user *arg)
212 {
213 struct { u8 u[ETH_ALEN]; } *addr;
214 struct tun_filter uf;
215 int err, alen, n, nexact;
216
217 if (copy_from_user(&uf, arg, sizeof(uf)))
218 return -EFAULT;
219
220 if (!uf.count) {
221 /* Disabled */
222 filter->count = 0;
223 return 0;
224 }
225
226 alen = ETH_ALEN * uf.count;
227 addr = kmalloc(alen, GFP_KERNEL);
228 if (!addr)
229 return -ENOMEM;
230
231 if (copy_from_user(addr, arg + sizeof(uf), alen)) {
232 err = -EFAULT;
233 goto done;
234 }
235
236 /* The filter is updated without holding any locks. Which is
237 * perfectly safe. We disable it first and in the worst
238 * case we'll accept a few undesired packets. */
239 filter->count = 0;
240 wmb();
241
242 /* Use first set of addresses as an exact filter */
243 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
244 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
245
246 nexact = n;
247
248 /* The rest is hashed */
249 memset(filter->mask, 0, sizeof(filter->mask));
250 for (; n < uf.count; n++)
251 addr_hash_set(filter->mask, addr[n].u);
252
253 /* For ALLMULTI just set the mask to all ones.
254 * This overrides the mask populated above. */
255 if ((uf.flags & TUN_FLT_ALLMULTI))
256 memset(filter->mask, ~0, sizeof(filter->mask));
257
258 /* Now enable the filter */
259 wmb();
260 filter->count = nexact;
261
262 /* Return the number of exact filters */
263 err = nexact;
264
265 done:
266 kfree(addr);
267 return err;
268 }
269
270 /* Returns: 0 - drop, !=0 - accept */
271 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
272 {
273 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
274 * at this point. */
275 struct ethhdr *eh = (struct ethhdr *) skb->data;
276 int i;
277
278 /* Exact match */
279 for (i = 0; i < filter->count; i++)
280 if (!compare_ether_addr(eh->h_dest, filter->addr[i]))
281 return 1;
282
283 /* Inexact match (multicast only) */
284 if (is_multicast_ether_addr(eh->h_dest))
285 return addr_hash_test(filter->mask, eh->h_dest);
286
287 return 0;
288 }
289
290 /*
291 * Checks whether the packet is accepted or not.
292 * Returns: 0 - drop, !=0 - accept
293 */
294 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
295 {
296 if (!filter->count)
297 return 1;
298
299 return run_filter(filter, skb);
300 }
301
302 /* Network device part of the driver */
303
304 static const struct ethtool_ops tun_ethtool_ops;
305
306 /* Net device detach from fd. */
307 static void tun_net_uninit(struct net_device *dev)
308 {
309 struct tun_struct *tun = netdev_priv(dev);
310 struct tun_file *tfile = tun->tfile;
311
312 /* Inform the methods they need to stop using the dev.
313 */
314 if (tfile) {
315 wake_up_all(&tfile->read_wait);
316 if (atomic_dec_and_test(&tfile->count))
317 __tun_detach(tun);
318 }
319 }
320
321 /* Net device open. */
322 static int tun_net_open(struct net_device *dev)
323 {
324 netif_start_queue(dev);
325 return 0;
326 }
327
328 /* Net device close. */
329 static int tun_net_close(struct net_device *dev)
330 {
331 netif_stop_queue(dev);
332 return 0;
333 }
334
335 /* Net device start xmit */
336 static int tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
337 {
338 struct tun_struct *tun = netdev_priv(dev);
339
340 DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len);
341
342 /* Drop packet if interface is not attached */
343 if (!tun->tfile)
344 goto drop;
345
346 /* Drop if the filter does not like it.
347 * This is a noop if the filter is disabled.
348 * Filter can be enabled only for the TAP devices. */
349 if (!check_filter(&tun->txflt, skb))
350 goto drop;
351
352 if (skb_queue_len(&tun->readq) >= dev->tx_queue_len) {
353 if (!(tun->flags & TUN_ONE_QUEUE)) {
354 /* Normal queueing mode. */
355 /* Packet scheduler handles dropping of further packets. */
356 netif_stop_queue(dev);
357
358 /* We won't see all dropped packets individually, so overrun
359 * error is more appropriate. */
360 dev->stats.tx_fifo_errors++;
361 } else {
362 /* Single queue mode.
363 * Driver handles dropping of all packets itself. */
364 goto drop;
365 }
366 }
367
368 /* Enqueue packet */
369 skb_queue_tail(&tun->readq, skb);
370 dev->trans_start = jiffies;
371
372 /* Notify and wake up reader process */
373 if (tun->flags & TUN_FASYNC)
374 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
375 wake_up_interruptible(&tun->tfile->read_wait);
376 return 0;
377
378 drop:
379 dev->stats.tx_dropped++;
380 kfree_skb(skb);
381 return 0;
382 }
383
384 static void tun_net_mclist(struct net_device *dev)
385 {
386 /*
387 * This callback is supposed to deal with mc filter in
388 * _rx_ path and has nothing to do with the _tx_ path.
389 * In rx path we always accept everything userspace gives us.
390 */
391 return;
392 }
393
394 #define MIN_MTU 68
395 #define MAX_MTU 65535
396
397 static int
398 tun_net_change_mtu(struct net_device *dev, int new_mtu)
399 {
400 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
401 return -EINVAL;
402 dev->mtu = new_mtu;
403 return 0;
404 }
405
406 static const struct net_device_ops tun_netdev_ops = {
407 .ndo_uninit = tun_net_uninit,
408 .ndo_open = tun_net_open,
409 .ndo_stop = tun_net_close,
410 .ndo_start_xmit = tun_net_xmit,
411 .ndo_change_mtu = tun_net_change_mtu,
412 };
413
414 static const struct net_device_ops tap_netdev_ops = {
415 .ndo_uninit = tun_net_uninit,
416 .ndo_open = tun_net_open,
417 .ndo_stop = tun_net_close,
418 .ndo_start_xmit = tun_net_xmit,
419 .ndo_change_mtu = tun_net_change_mtu,
420 .ndo_set_multicast_list = tun_net_mclist,
421 .ndo_set_mac_address = eth_mac_addr,
422 .ndo_validate_addr = eth_validate_addr,
423 };
424
425 /* Initialize net device. */
426 static void tun_net_init(struct net_device *dev)
427 {
428 struct tun_struct *tun = netdev_priv(dev);
429
430 switch (tun->flags & TUN_TYPE_MASK) {
431 case TUN_TUN_DEV:
432 dev->netdev_ops = &tun_netdev_ops;
433
434 /* Point-to-Point TUN Device */
435 dev->hard_header_len = 0;
436 dev->addr_len = 0;
437 dev->mtu = 1500;
438
439 /* Zero header length */
440 dev->type = ARPHRD_NONE;
441 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
442 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
443 break;
444
445 case TUN_TAP_DEV:
446 dev->netdev_ops = &tap_netdev_ops;
447 /* Ethernet TAP Device */
448 ether_setup(dev);
449
450 random_ether_addr(dev->dev_addr);
451
452 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
453 break;
454 }
455 }
456
457 /* Character device part */
458
459 /* Poll */
460 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
461 {
462 struct tun_file *tfile = file->private_data;
463 struct tun_struct *tun = __tun_get(tfile);
464 unsigned int mask = POLLOUT | POLLWRNORM;
465
466 if (!tun)
467 return POLLERR;
468
469 DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
470
471 poll_wait(file, &tfile->read_wait, wait);
472
473 if (!skb_queue_empty(&tun->readq))
474 mask |= POLLIN | POLLRDNORM;
475
476 if (tun->dev->reg_state != NETREG_REGISTERED)
477 mask = POLLERR;
478
479 tun_put(tun);
480 return mask;
481 }
482
483 /* prepad is the amount to reserve at front. len is length after that.
484 * linear is a hint as to how much to copy (usually headers). */
485 static struct sk_buff *tun_alloc_skb(size_t prepad, size_t len, size_t linear,
486 gfp_t gfp)
487 {
488 struct sk_buff *skb;
489 unsigned int i;
490
491 skb = alloc_skb(prepad + len, gfp|__GFP_NOWARN);
492 if (skb) {
493 skb_reserve(skb, prepad);
494 skb_put(skb, len);
495 return skb;
496 }
497
498 /* Under a page? Don't bother with paged skb. */
499 if (prepad + len < PAGE_SIZE)
500 return NULL;
501
502 /* Start with a normal skb, and add pages. */
503 skb = alloc_skb(prepad + linear, gfp);
504 if (!skb)
505 return NULL;
506
507 skb_reserve(skb, prepad);
508 skb_put(skb, linear);
509
510 len -= linear;
511
512 for (i = 0; i < MAX_SKB_FRAGS; i++) {
513 skb_frag_t *f = &skb_shinfo(skb)->frags[i];
514
515 f->page = alloc_page(gfp|__GFP_ZERO);
516 if (!f->page)
517 break;
518
519 f->page_offset = 0;
520 f->size = PAGE_SIZE;
521
522 skb->data_len += PAGE_SIZE;
523 skb->len += PAGE_SIZE;
524 skb->truesize += PAGE_SIZE;
525 skb_shinfo(skb)->nr_frags++;
526
527 if (len < PAGE_SIZE) {
528 len = 0;
529 break;
530 }
531 len -= PAGE_SIZE;
532 }
533
534 /* Too large, or alloc fail? */
535 if (unlikely(len)) {
536 kfree_skb(skb);
537 skb = NULL;
538 }
539
540 return skb;
541 }
542
543 /* Get packet from user space buffer */
544 static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, size_t count)
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 return -EINVAL;
574 }
575
576 if (!(skb = tun_alloc_skb(align, len, gso.hdr_len, GFP_KERNEL))) {
577 tun->dev->stats.rx_dropped++;
578 return -ENOMEM;
579 }
580
581 if (skb_copy_datagram_from_iovec(skb, 0, iv, len)) {
582 tun->dev->stats.rx_dropped++;
583 kfree_skb(skb);
584 return -EFAULT;
585 }
586
587 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
588 if (!skb_partial_csum_set(skb, gso.csum_start,
589 gso.csum_offset)) {
590 tun->dev->stats.rx_frame_errors++;
591 kfree_skb(skb);
592 return -EINVAL;
593 }
594 } else if (tun->flags & TUN_NOCHECKSUM)
595 skb->ip_summed = CHECKSUM_UNNECESSARY;
596
597 switch (tun->flags & TUN_TYPE_MASK) {
598 case TUN_TUN_DEV:
599 if (tun->flags & TUN_NO_PI) {
600 switch (skb->data[0] & 0xf0) {
601 case 0x40:
602 pi.proto = htons(ETH_P_IP);
603 break;
604 case 0x60:
605 pi.proto = htons(ETH_P_IPV6);
606 break;
607 default:
608 tun->dev->stats.rx_dropped++;
609 kfree_skb(skb);
610 return -EINVAL;
611 }
612 }
613
614 skb_reset_mac_header(skb);
615 skb->protocol = pi.proto;
616 skb->dev = tun->dev;
617 break;
618 case TUN_TAP_DEV:
619 skb->protocol = eth_type_trans(skb, tun->dev);
620 break;
621 };
622
623 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
624 pr_debug("GSO!\n");
625 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
626 case VIRTIO_NET_HDR_GSO_TCPV4:
627 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
628 break;
629 case VIRTIO_NET_HDR_GSO_TCPV6:
630 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
631 break;
632 default:
633 tun->dev->stats.rx_frame_errors++;
634 kfree_skb(skb);
635 return -EINVAL;
636 }
637
638 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
639 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
640
641 skb_shinfo(skb)->gso_size = gso.gso_size;
642 if (skb_shinfo(skb)->gso_size == 0) {
643 tun->dev->stats.rx_frame_errors++;
644 kfree_skb(skb);
645 return -EINVAL;
646 }
647
648 /* Header must be checked, and gso_segs computed. */
649 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
650 skb_shinfo(skb)->gso_segs = 0;
651 }
652
653 netif_rx_ni(skb);
654
655 tun->dev->stats.rx_packets++;
656 tun->dev->stats.rx_bytes += len;
657
658 return count;
659 }
660
661 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
662 unsigned long count, loff_t pos)
663 {
664 struct tun_struct *tun = tun_get(iocb->ki_filp);
665 ssize_t result;
666
667 if (!tun)
668 return -EBADFD;
669
670 DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
671
672 result = tun_get_user(tun, (struct iovec *) iv, iov_length(iv, count));
673
674 tun_put(tun);
675 return result;
676 }
677
678 /* Put packet to the user space buffer */
679 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
680 struct sk_buff *skb,
681 struct iovec *iv, int len)
682 {
683 struct tun_pi pi = { 0, skb->protocol };
684 ssize_t total = 0;
685
686 if (!(tun->flags & TUN_NO_PI)) {
687 if ((len -= sizeof(pi)) < 0)
688 return -EINVAL;
689
690 if (len < skb->len) {
691 /* Packet will be striped */
692 pi.flags |= TUN_PKT_STRIP;
693 }
694
695 if (memcpy_toiovec(iv, (void *) &pi, sizeof(pi)))
696 return -EFAULT;
697 total += sizeof(pi);
698 }
699
700 if (tun->flags & TUN_VNET_HDR) {
701 struct virtio_net_hdr gso = { 0 }; /* no info leak */
702 if ((len -= sizeof(gso)) < 0)
703 return -EINVAL;
704
705 if (skb_is_gso(skb)) {
706 struct skb_shared_info *sinfo = skb_shinfo(skb);
707
708 /* This is a hint as to how much should be linear. */
709 gso.hdr_len = skb_headlen(skb);
710 gso.gso_size = sinfo->gso_size;
711 if (sinfo->gso_type & SKB_GSO_TCPV4)
712 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
713 else if (sinfo->gso_type & SKB_GSO_TCPV6)
714 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
715 else
716 BUG();
717 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
718 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
719 } else
720 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
721
722 if (skb->ip_summed == CHECKSUM_PARTIAL) {
723 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
724 gso.csum_start = skb->csum_start - skb_headroom(skb);
725 gso.csum_offset = skb->csum_offset;
726 } /* else everything is zero */
727
728 if (unlikely(memcpy_toiovec(iv, (void *)&gso, sizeof(gso))))
729 return -EFAULT;
730 total += sizeof(gso);
731 }
732
733 len = min_t(int, skb->len, len);
734
735 skb_copy_datagram_iovec(skb, 0, iv, len);
736 total += len;
737
738 tun->dev->stats.tx_packets++;
739 tun->dev->stats.tx_bytes += len;
740
741 return total;
742 }
743
744 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
745 unsigned long count, loff_t pos)
746 {
747 struct file *file = iocb->ki_filp;
748 struct tun_file *tfile = file->private_data;
749 struct tun_struct *tun = __tun_get(tfile);
750 DECLARE_WAITQUEUE(wait, current);
751 struct sk_buff *skb;
752 ssize_t len, ret = 0;
753
754 if (!tun)
755 return -EBADFD;
756
757 DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
758
759 len = iov_length(iv, count);
760 if (len < 0) {
761 ret = -EINVAL;
762 goto out;
763 }
764
765 add_wait_queue(&tfile->read_wait, &wait);
766 while (len) {
767 current->state = TASK_INTERRUPTIBLE;
768
769 /* Read frames from the queue */
770 if (!(skb=skb_dequeue(&tun->readq))) {
771 if (file->f_flags & O_NONBLOCK) {
772 ret = -EAGAIN;
773 break;
774 }
775 if (signal_pending(current)) {
776 ret = -ERESTARTSYS;
777 break;
778 }
779 if (tun->dev->reg_state != NETREG_REGISTERED) {
780 ret = -EIO;
781 break;
782 }
783
784 /* Nothing to read, let's sleep */
785 schedule();
786 continue;
787 }
788 netif_wake_queue(tun->dev);
789
790 ret = tun_put_user(tun, skb, (struct iovec *) iv, len);
791 kfree_skb(skb);
792 break;
793 }
794
795 current->state = TASK_RUNNING;
796 remove_wait_queue(&tfile->read_wait, &wait);
797
798 out:
799 tun_put(tun);
800 return ret;
801 }
802
803 static void tun_setup(struct net_device *dev)
804 {
805 struct tun_struct *tun = netdev_priv(dev);
806
807 skb_queue_head_init(&tun->readq);
808
809 tun->owner = -1;
810 tun->group = -1;
811
812 dev->ethtool_ops = &tun_ethtool_ops;
813 dev->destructor = free_netdev;
814 }
815
816 /* Trivial set of netlink ops to allow deleting tun or tap
817 * device with netlink.
818 */
819 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
820 {
821 return -EINVAL;
822 }
823
824 static struct rtnl_link_ops tun_link_ops __read_mostly = {
825 .kind = DRV_NAME,
826 .priv_size = sizeof(struct tun_struct),
827 .setup = tun_setup,
828 .validate = tun_validate,
829 };
830
831
832 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
833 {
834 struct tun_struct *tun;
835 struct net_device *dev;
836 int err;
837
838 dev = __dev_get_by_name(net, ifr->ifr_name);
839 if (dev) {
840 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
841 tun = netdev_priv(dev);
842 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
843 tun = netdev_priv(dev);
844 else
845 return -EINVAL;
846
847 err = tun_attach(tun, file);
848 if (err < 0)
849 return err;
850 }
851 else {
852 char *name;
853 unsigned long flags = 0;
854
855 err = -EINVAL;
856
857 if (!capable(CAP_NET_ADMIN))
858 return -EPERM;
859
860 /* Set dev type */
861 if (ifr->ifr_flags & IFF_TUN) {
862 /* TUN device */
863 flags |= TUN_TUN_DEV;
864 name = "tun%d";
865 } else if (ifr->ifr_flags & IFF_TAP) {
866 /* TAP device */
867 flags |= TUN_TAP_DEV;
868 name = "tap%d";
869 } else
870 goto failed;
871
872 if (*ifr->ifr_name)
873 name = ifr->ifr_name;
874
875 dev = alloc_netdev(sizeof(struct tun_struct), name,
876 tun_setup);
877 if (!dev)
878 return -ENOMEM;
879
880 dev_net_set(dev, net);
881 dev->rtnl_link_ops = &tun_link_ops;
882
883 tun = netdev_priv(dev);
884 tun->dev = dev;
885 tun->flags = flags;
886 tun->txflt.count = 0;
887
888 tun_net_init(dev);
889
890 if (strchr(dev->name, '%')) {
891 err = dev_alloc_name(dev, dev->name);
892 if (err < 0)
893 goto err_free_dev;
894 }
895
896 err = register_netdevice(tun->dev);
897 if (err < 0)
898 goto err_free_dev;
899
900 err = tun_attach(tun, file);
901 if (err < 0)
902 goto err_free_dev;
903 }
904
905 DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
906
907 if (ifr->ifr_flags & IFF_NO_PI)
908 tun->flags |= TUN_NO_PI;
909 else
910 tun->flags &= ~TUN_NO_PI;
911
912 if (ifr->ifr_flags & IFF_ONE_QUEUE)
913 tun->flags |= TUN_ONE_QUEUE;
914 else
915 tun->flags &= ~TUN_ONE_QUEUE;
916
917 if (ifr->ifr_flags & IFF_VNET_HDR)
918 tun->flags |= TUN_VNET_HDR;
919 else
920 tun->flags &= ~TUN_VNET_HDR;
921
922 /* Make sure persistent devices do not get stuck in
923 * xoff state.
924 */
925 if (netif_running(tun->dev))
926 netif_wake_queue(tun->dev);
927
928 strcpy(ifr->ifr_name, tun->dev->name);
929 return 0;
930
931 err_free_dev:
932 free_netdev(dev);
933 failed:
934 return err;
935 }
936
937 static int tun_get_iff(struct net *net, struct file *file, struct ifreq *ifr)
938 {
939 struct tun_struct *tun = tun_get(file);
940
941 if (!tun)
942 return -EBADFD;
943
944 DBG(KERN_INFO "%s: tun_get_iff\n", tun->dev->name);
945
946 strcpy(ifr->ifr_name, tun->dev->name);
947
948 ifr->ifr_flags = 0;
949
950 if (ifr->ifr_flags & TUN_TUN_DEV)
951 ifr->ifr_flags |= IFF_TUN;
952 else
953 ifr->ifr_flags |= IFF_TAP;
954
955 if (tun->flags & TUN_NO_PI)
956 ifr->ifr_flags |= IFF_NO_PI;
957
958 if (tun->flags & TUN_ONE_QUEUE)
959 ifr->ifr_flags |= IFF_ONE_QUEUE;
960
961 if (tun->flags & TUN_VNET_HDR)
962 ifr->ifr_flags |= IFF_VNET_HDR;
963
964 tun_put(tun);
965 return 0;
966 }
967
968 /* This is like a cut-down ethtool ops, except done via tun fd so no
969 * privs required. */
970 static int set_offload(struct net_device *dev, unsigned long arg)
971 {
972 unsigned int old_features, features;
973
974 old_features = dev->features;
975 /* Unset features, set them as we chew on the arg. */
976 features = (old_features & ~(NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST
977 |NETIF_F_TSO_ECN|NETIF_F_TSO|NETIF_F_TSO6));
978
979 if (arg & TUN_F_CSUM) {
980 features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
981 arg &= ~TUN_F_CSUM;
982
983 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
984 if (arg & TUN_F_TSO_ECN) {
985 features |= NETIF_F_TSO_ECN;
986 arg &= ~TUN_F_TSO_ECN;
987 }
988 if (arg & TUN_F_TSO4)
989 features |= NETIF_F_TSO;
990 if (arg & TUN_F_TSO6)
991 features |= NETIF_F_TSO6;
992 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
993 }
994 }
995
996 /* This gives the user a way to test for new features in future by
997 * trying to set them. */
998 if (arg)
999 return -EINVAL;
1000
1001 dev->features = features;
1002 if (old_features != dev->features)
1003 netdev_features_change(dev);
1004
1005 return 0;
1006 }
1007
1008 static int tun_chr_ioctl(struct inode *inode, struct file *file,
1009 unsigned int cmd, unsigned long arg)
1010 {
1011 struct tun_file *tfile = file->private_data;
1012 struct tun_struct *tun;
1013 void __user* argp = (void __user*)arg;
1014 struct ifreq ifr;
1015 int ret;
1016
1017 if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
1018 if (copy_from_user(&ifr, argp, sizeof ifr))
1019 return -EFAULT;
1020
1021 if (cmd == TUNGETFEATURES) {
1022 /* Currently this just means: "what IFF flags are valid?".
1023 * This is needed because we never checked for invalid flags on
1024 * TUNSETIFF. */
1025 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
1026 IFF_VNET_HDR,
1027 (unsigned int __user*)argp);
1028 }
1029
1030 tun = __tun_get(tfile);
1031 if (cmd == TUNSETIFF && !tun) {
1032 int err;
1033
1034 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1035
1036 rtnl_lock();
1037 err = tun_set_iff(tfile->net, file, &ifr);
1038 rtnl_unlock();
1039
1040 if (err)
1041 return err;
1042
1043 if (copy_to_user(argp, &ifr, sizeof(ifr)))
1044 return -EFAULT;
1045 return 0;
1046 }
1047
1048
1049 if (!tun)
1050 return -EBADFD;
1051
1052 DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
1053
1054 ret = 0;
1055 switch (cmd) {
1056 case TUNGETIFF:
1057 ret = tun_get_iff(current->nsproxy->net_ns, file, &ifr);
1058 if (ret)
1059 break;
1060
1061 if (copy_to_user(argp, &ifr, sizeof(ifr)))
1062 ret = -EFAULT;
1063 break;
1064
1065 case TUNSETNOCSUM:
1066 /* Disable/Enable checksum */
1067 if (arg)
1068 tun->flags |= TUN_NOCHECKSUM;
1069 else
1070 tun->flags &= ~TUN_NOCHECKSUM;
1071
1072 DBG(KERN_INFO "%s: checksum %s\n",
1073 tun->dev->name, arg ? "disabled" : "enabled");
1074 break;
1075
1076 case TUNSETPERSIST:
1077 /* Disable/Enable persist mode */
1078 if (arg)
1079 tun->flags |= TUN_PERSIST;
1080 else
1081 tun->flags &= ~TUN_PERSIST;
1082
1083 DBG(KERN_INFO "%s: persist %s\n",
1084 tun->dev->name, arg ? "enabled" : "disabled");
1085 break;
1086
1087 case TUNSETOWNER:
1088 /* Set owner of the device */
1089 tun->owner = (uid_t) arg;
1090
1091 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
1092 break;
1093
1094 case TUNSETGROUP:
1095 /* Set group of the device */
1096 tun->group= (gid_t) arg;
1097
1098 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group);
1099 break;
1100
1101 case TUNSETLINK:
1102 /* Only allow setting the type when the interface is down */
1103 rtnl_lock();
1104 if (tun->dev->flags & IFF_UP) {
1105 DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
1106 tun->dev->name);
1107 ret = -EBUSY;
1108 } else {
1109 tun->dev->type = (int) arg;
1110 DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
1111 ret = 0;
1112 }
1113 rtnl_unlock();
1114 break;
1115
1116 #ifdef TUN_DEBUG
1117 case TUNSETDEBUG:
1118 tun->debug = arg;
1119 break;
1120 #endif
1121 case TUNSETOFFLOAD:
1122 rtnl_lock();
1123 ret = set_offload(tun->dev, arg);
1124 rtnl_unlock();
1125 break;
1126
1127 case TUNSETTXFILTER:
1128 /* Can be set only for TAPs */
1129 ret = -EINVAL;
1130 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1131 break;
1132 rtnl_lock();
1133 ret = update_filter(&tun->txflt, (void __user *)arg);
1134 rtnl_unlock();
1135 break;
1136
1137 case SIOCGIFHWADDR:
1138 /* Get hw addres */
1139 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
1140 ifr.ifr_hwaddr.sa_family = tun->dev->type;
1141 if (copy_to_user(argp, &ifr, sizeof ifr))
1142 ret = -EFAULT;
1143 break;
1144
1145 case SIOCSIFHWADDR:
1146 /* Set hw address */
1147 DBG(KERN_DEBUG "%s: set hw address: %pM\n",
1148 tun->dev->name, ifr.ifr_hwaddr.sa_data);
1149
1150 rtnl_lock();
1151 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
1152 rtnl_unlock();
1153 break;
1154 default:
1155 ret = -EINVAL;
1156 break;
1157 };
1158
1159 tun_put(tun);
1160 return ret;
1161 }
1162
1163 static int tun_chr_fasync(int fd, struct file *file, int on)
1164 {
1165 struct tun_struct *tun = tun_get(file);
1166 int ret;
1167
1168 if (!tun)
1169 return -EBADFD;
1170
1171 DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
1172
1173 lock_kernel();
1174 if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
1175 goto out;
1176
1177 if (on) {
1178 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
1179 if (ret)
1180 goto out;
1181 tun->flags |= TUN_FASYNC;
1182 } else
1183 tun->flags &= ~TUN_FASYNC;
1184 ret = 0;
1185 out:
1186 unlock_kernel();
1187 tun_put(tun);
1188 return ret;
1189 }
1190
1191 static int tun_chr_open(struct inode *inode, struct file * file)
1192 {
1193 struct tun_file *tfile;
1194 cycle_kernel_lock();
1195 DBG1(KERN_INFO "tunX: tun_chr_open\n");
1196
1197 tfile = kmalloc(sizeof(*tfile), GFP_KERNEL);
1198 if (!tfile)
1199 return -ENOMEM;
1200 atomic_set(&tfile->count, 0);
1201 tfile->tun = NULL;
1202 tfile->net = get_net(current->nsproxy->net_ns);
1203 init_waitqueue_head(&tfile->read_wait);
1204 file->private_data = tfile;
1205 return 0;
1206 }
1207
1208 static int tun_chr_close(struct inode *inode, struct file *file)
1209 {
1210 struct tun_file *tfile = file->private_data;
1211 struct tun_struct *tun = __tun_get(tfile);
1212
1213
1214 if (tun) {
1215 DBG(KERN_INFO "%s: tun_chr_close\n", tun->dev->name);
1216
1217 rtnl_lock();
1218 __tun_detach(tun);
1219
1220 /* If desireable, unregister the netdevice. */
1221 if (!(tun->flags & TUN_PERSIST))
1222 unregister_netdevice(tun->dev);
1223
1224 rtnl_unlock();
1225 }
1226
1227 put_net(tfile->net);
1228 kfree(tfile);
1229
1230 return 0;
1231 }
1232
1233 static const struct file_operations tun_fops = {
1234 .owner = THIS_MODULE,
1235 .llseek = no_llseek,
1236 .read = do_sync_read,
1237 .aio_read = tun_chr_aio_read,
1238 .write = do_sync_write,
1239 .aio_write = tun_chr_aio_write,
1240 .poll = tun_chr_poll,
1241 .ioctl = tun_chr_ioctl,
1242 .open = tun_chr_open,
1243 .release = tun_chr_close,
1244 .fasync = tun_chr_fasync
1245 };
1246
1247 static struct miscdevice tun_miscdev = {
1248 .minor = TUN_MINOR,
1249 .name = "tun",
1250 .fops = &tun_fops,
1251 };
1252
1253 /* ethtool interface */
1254
1255 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1256 {
1257 cmd->supported = 0;
1258 cmd->advertising = 0;
1259 cmd->speed = SPEED_10;
1260 cmd->duplex = DUPLEX_FULL;
1261 cmd->port = PORT_TP;
1262 cmd->phy_address = 0;
1263 cmd->transceiver = XCVR_INTERNAL;
1264 cmd->autoneg = AUTONEG_DISABLE;
1265 cmd->maxtxpkt = 0;
1266 cmd->maxrxpkt = 0;
1267 return 0;
1268 }
1269
1270 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
1271 {
1272 struct tun_struct *tun = netdev_priv(dev);
1273
1274 strcpy(info->driver, DRV_NAME);
1275 strcpy(info->version, DRV_VERSION);
1276 strcpy(info->fw_version, "N/A");
1277
1278 switch (tun->flags & TUN_TYPE_MASK) {
1279 case TUN_TUN_DEV:
1280 strcpy(info->bus_info, "tun");
1281 break;
1282 case TUN_TAP_DEV:
1283 strcpy(info->bus_info, "tap");
1284 break;
1285 }
1286 }
1287
1288 static u32 tun_get_msglevel(struct net_device *dev)
1289 {
1290 #ifdef TUN_DEBUG
1291 struct tun_struct *tun = netdev_priv(dev);
1292 return tun->debug;
1293 #else
1294 return -EOPNOTSUPP;
1295 #endif
1296 }
1297
1298 static void tun_set_msglevel(struct net_device *dev, u32 value)
1299 {
1300 #ifdef TUN_DEBUG
1301 struct tun_struct *tun = netdev_priv(dev);
1302 tun->debug = value;
1303 #endif
1304 }
1305
1306 static u32 tun_get_link(struct net_device *dev)
1307 {
1308 struct tun_struct *tun = netdev_priv(dev);
1309 return !!tun->tfile;
1310 }
1311
1312 static u32 tun_get_rx_csum(struct net_device *dev)
1313 {
1314 struct tun_struct *tun = netdev_priv(dev);
1315 return (tun->flags & TUN_NOCHECKSUM) == 0;
1316 }
1317
1318 static int tun_set_rx_csum(struct net_device *dev, u32 data)
1319 {
1320 struct tun_struct *tun = netdev_priv(dev);
1321 if (data)
1322 tun->flags &= ~TUN_NOCHECKSUM;
1323 else
1324 tun->flags |= TUN_NOCHECKSUM;
1325 return 0;
1326 }
1327
1328 static const struct ethtool_ops tun_ethtool_ops = {
1329 .get_settings = tun_get_settings,
1330 .get_drvinfo = tun_get_drvinfo,
1331 .get_msglevel = tun_get_msglevel,
1332 .set_msglevel = tun_set_msglevel,
1333 .get_link = tun_get_link,
1334 .get_rx_csum = tun_get_rx_csum,
1335 .set_rx_csum = tun_set_rx_csum
1336 };
1337
1338
1339 static int __init tun_init(void)
1340 {
1341 int ret = 0;
1342
1343 printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
1344 printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
1345
1346 ret = rtnl_link_register(&tun_link_ops);
1347 if (ret) {
1348 printk(KERN_ERR "tun: Can't register link_ops\n");
1349 goto err_linkops;
1350 }
1351
1352 ret = misc_register(&tun_miscdev);
1353 if (ret) {
1354 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
1355 goto err_misc;
1356 }
1357 return 0;
1358 err_misc:
1359 rtnl_link_unregister(&tun_link_ops);
1360 err_linkops:
1361 return ret;
1362 }
1363
1364 static void tun_cleanup(void)
1365 {
1366 misc_deregister(&tun_miscdev);
1367 rtnl_link_unregister(&tun_link_ops);
1368 }
1369
1370 module_init(tun_init);
1371 module_exit(tun_cleanup);
1372 MODULE_DESCRIPTION(DRV_DESCRIPTION);
1373 MODULE_AUTHOR(DRV_COPYRIGHT);
1374 MODULE_LICENSE("GPL");
1375 MODULE_ALIAS_MISCDEV(TUN_MINOR);
Support for the Chinese Samsung S3C2440 based development boards