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ALSA: Clean up snd_monitor_file management
[linux-2.6/mini2440.git] / drivers / net / tun.c
blob09fea31d3e360da7d79afeb25c399ef6286f4951
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 /* Remaining multicast addresses are hashed,
161 * unicast will leave the filter disabled. */
162 memset(filter->mask, 0, sizeof(filter->mask));
163 for (; n < uf.count; n++) {
164 if (!is_multicast_ether_addr(addr[n].u)) {
165 err = 0; /* no filter */
166 goto done;
167 }
168 addr_hash_set(filter->mask, addr[n].u);
169 }
170
171 /* For ALLMULTI just set the mask to all ones.
172 * This overrides the mask populated above. */
173 if ((uf.flags & TUN_FLT_ALLMULTI))
174 memset(filter->mask, ~0, sizeof(filter->mask));
175
176 /* Now enable the filter */
177 wmb();
178 filter->count = nexact;
179
180 /* Return the number of exact filters */
181 err = nexact;
182
183 done:
184 kfree(addr);
185 return err;
186 }
187
188 /* Returns: 0 - drop, !=0 - accept */
189 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
190 {
191 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
192 * at this point. */
193 struct ethhdr *eh = (struct ethhdr *) skb->data;
194 int i;
195
196 /* Exact match */
197 for (i = 0; i < filter->count; i++)
198 if (!compare_ether_addr(eh->h_dest, filter->addr[i]))
199 return 1;
200
201 /* Inexact match (multicast only) */
202 if (is_multicast_ether_addr(eh->h_dest))
203 return addr_hash_test(filter->mask, eh->h_dest);
204
205 return 0;
206 }
207
208 /*
209 * Checks whether the packet is accepted or not.
210 * Returns: 0 - drop, !=0 - accept
211 */
212 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
213 {
214 if (!filter->count)
215 return 1;
216
217 return run_filter(filter, skb);
218 }
219
220 /* Network device part of the driver */
221
222 static int tun_net_id;
223 struct tun_net {
224 struct list_head dev_list;
225 };
226
227 static const struct ethtool_ops tun_ethtool_ops;
228
229 /* Net device open. */
230 static int tun_net_open(struct net_device *dev)
231 {
232 netif_start_queue(dev);
233 return 0;
234 }
235
236 /* Net device close. */
237 static int tun_net_close(struct net_device *dev)
238 {
239 netif_stop_queue(dev);
240 return 0;
241 }
242
243 /* Net device start xmit */
244 static int tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
245 {
246 struct tun_struct *tun = netdev_priv(dev);
247
248 DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len);
249
250 /* Drop packet if interface is not attached */
251 if (!tun->attached)
252 goto drop;
253
254 /* Drop if the filter does not like it.
255 * This is a noop if the filter is disabled.
256 * Filter can be enabled only for the TAP devices. */
257 if (!check_filter(&tun->txflt, skb))
258 goto drop;
259
260 if (skb_queue_len(&tun->readq) >= dev->tx_queue_len) {
261 if (!(tun->flags & TUN_ONE_QUEUE)) {
262 /* Normal queueing mode. */
263 /* Packet scheduler handles dropping of further packets. */
264 netif_stop_queue(dev);
265
266 /* We won't see all dropped packets individually, so overrun
267 * error is more appropriate. */
268 dev->stats.tx_fifo_errors++;
269 } else {
270 /* Single queue mode.
271 * Driver handles dropping of all packets itself. */
272 goto drop;
273 }
274 }
275
276 /* Enqueue packet */
277 skb_queue_tail(&tun->readq, skb);
278 dev->trans_start = jiffies;
279
280 /* Notify and wake up reader process */
281 if (tun->flags & TUN_FASYNC)
282 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
283 wake_up_interruptible(&tun->read_wait);
284 return 0;
285
286 drop:
287 dev->stats.tx_dropped++;
288 kfree_skb(skb);
289 return 0;
290 }
291
292 static void tun_net_mclist(struct net_device *dev)
293 {
294 /*
295 * This callback is supposed to deal with mc filter in
296 * _rx_ path and has nothing to do with the _tx_ path.
297 * In rx path we always accept everything userspace gives us.
298 */
299 return;
300 }
301
302 #define MIN_MTU 68
303 #define MAX_MTU 65535
304
305 static int
306 tun_net_change_mtu(struct net_device *dev, int new_mtu)
307 {
308 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
309 return -EINVAL;
310 dev->mtu = new_mtu;
311 return 0;
312 }
313
314 static const struct net_device_ops tun_netdev_ops = {
315 .ndo_open = tun_net_open,
316 .ndo_stop = tun_net_close,
317 .ndo_start_xmit = tun_net_xmit,
318 .ndo_change_mtu = tun_net_change_mtu,
319 };
320
321 static const struct net_device_ops tap_netdev_ops = {
322 .ndo_open = tun_net_open,
323 .ndo_stop = tun_net_close,
324 .ndo_start_xmit = tun_net_xmit,
325 .ndo_change_mtu = tun_net_change_mtu,
326 .ndo_set_multicast_list = tun_net_mclist,
327 .ndo_set_mac_address = eth_mac_addr,
328 .ndo_validate_addr = eth_validate_addr,
329 };
330
331 /* Initialize net device. */
332 static void tun_net_init(struct net_device *dev)
333 {
334 struct tun_struct *tun = netdev_priv(dev);
335
336 switch (tun->flags & TUN_TYPE_MASK) {
337 case TUN_TUN_DEV:
338 dev->netdev_ops = &tun_netdev_ops;
339
340 /* Point-to-Point TUN Device */
341 dev->hard_header_len = 0;
342 dev->addr_len = 0;
343 dev->mtu = 1500;
344
345 /* Zero header length */
346 dev->type = ARPHRD_NONE;
347 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
348 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
349 break;
350
351 case TUN_TAP_DEV:
352 dev->netdev_ops = &tap_netdev_ops;
353 /* Ethernet TAP Device */
354 ether_setup(dev);
355
356 random_ether_addr(dev->dev_addr);
357
358 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
359 break;
360 }
361 }
362
363 /* Character device part */
364
365 /* Poll */
366 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
367 {
368 struct tun_struct *tun = file->private_data;
369 unsigned int mask = POLLOUT | POLLWRNORM;
370
371 if (!tun)
372 return -EBADFD;
373
374 DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
375
376 poll_wait(file, &tun->read_wait, wait);
377
378 if (!skb_queue_empty(&tun->readq))
379 mask |= POLLIN | POLLRDNORM;
380
381 return mask;
382 }
383
384 /* prepad is the amount to reserve at front. len is length after that.
385 * linear is a hint as to how much to copy (usually headers). */
386 static struct sk_buff *tun_alloc_skb(size_t prepad, size_t len, size_t linear,
387 gfp_t gfp)
388 {
389 struct sk_buff *skb;
390 unsigned int i;
391
392 skb = alloc_skb(prepad + len, gfp|__GFP_NOWARN);
393 if (skb) {
394 skb_reserve(skb, prepad);
395 skb_put(skb, len);
396 return skb;
397 }
398
399 /* Under a page? Don't bother with paged skb. */
400 if (prepad + len < PAGE_SIZE)
401 return NULL;
402
403 /* Start with a normal skb, and add pages. */
404 skb = alloc_skb(prepad + linear, gfp);
405 if (!skb)
406 return NULL;
407
408 skb_reserve(skb, prepad);
409 skb_put(skb, linear);
410
411 len -= linear;
412
413 for (i = 0; i < MAX_SKB_FRAGS; i++) {
414 skb_frag_t *f = &skb_shinfo(skb)->frags[i];
415
416 f->page = alloc_page(gfp|__GFP_ZERO);
417 if (!f->page)
418 break;
419
420 f->page_offset = 0;
421 f->size = PAGE_SIZE;
422
423 skb->data_len += PAGE_SIZE;
424 skb->len += PAGE_SIZE;
425 skb->truesize += PAGE_SIZE;
426 skb_shinfo(skb)->nr_frags++;
427
428 if (len < PAGE_SIZE) {
429 len = 0;
430 break;
431 }
432 len -= PAGE_SIZE;
433 }
434
435 /* Too large, or alloc fail? */
436 if (unlikely(len)) {
437 kfree_skb(skb);
438 skb = NULL;
439 }
440
441 return skb;
442 }
443
444 /* Get packet from user space buffer */
445 static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, size_t count)
446 {
447 struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) };
448 struct sk_buff *skb;
449 size_t len = count, align = 0;
450 struct virtio_net_hdr gso = { 0 };
451
452 if (!(tun->flags & TUN_NO_PI)) {
453 if ((len -= sizeof(pi)) > count)
454 return -EINVAL;
455
456 if(memcpy_fromiovec((void *)&pi, iv, sizeof(pi)))
457 return -EFAULT;
458 }
459
460 if (tun->flags & TUN_VNET_HDR) {
461 if ((len -= sizeof(gso)) > count)
462 return -EINVAL;
463
464 if (memcpy_fromiovec((void *)&gso, iv, sizeof(gso)))
465 return -EFAULT;
466
467 if (gso.hdr_len > len)
468 return -EINVAL;
469 }
470
471 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
472 align = NET_IP_ALIGN;
473 if (unlikely(len < ETH_HLEN))
474 return -EINVAL;
475 }
476
477 if (!(skb = tun_alloc_skb(align, len, gso.hdr_len, GFP_KERNEL))) {
478 tun->dev->stats.rx_dropped++;
479 return -ENOMEM;
480 }
481
482 if (skb_copy_datagram_from_iovec(skb, 0, iv, len)) {
483 tun->dev->stats.rx_dropped++;
484 kfree_skb(skb);
485 return -EFAULT;
486 }
487
488 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
489 if (!skb_partial_csum_set(skb, gso.csum_start,
490 gso.csum_offset)) {
491 tun->dev->stats.rx_frame_errors++;
492 kfree_skb(skb);
493 return -EINVAL;
494 }
495 } else if (tun->flags & TUN_NOCHECKSUM)
496 skb->ip_summed = CHECKSUM_UNNECESSARY;
497
498 switch (tun->flags & TUN_TYPE_MASK) {
499 case TUN_TUN_DEV:
500 if (tun->flags & TUN_NO_PI) {
501 switch (skb->data[0] & 0xf0) {
502 case 0x40:
503 pi.proto = htons(ETH_P_IP);
504 break;
505 case 0x60:
506 pi.proto = htons(ETH_P_IPV6);
507 break;
508 default:
509 tun->dev->stats.rx_dropped++;
510 kfree_skb(skb);
511 return -EINVAL;
512 }
513 }
514
515 skb_reset_mac_header(skb);
516 skb->protocol = pi.proto;
517 skb->dev = tun->dev;
518 break;
519 case TUN_TAP_DEV:
520 skb->protocol = eth_type_trans(skb, tun->dev);
521 break;
522 };
523
524 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
525 pr_debug("GSO!\n");
526 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
527 case VIRTIO_NET_HDR_GSO_TCPV4:
528 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
529 break;
530 case VIRTIO_NET_HDR_GSO_TCPV6:
531 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
532 break;
533 default:
534 tun->dev->stats.rx_frame_errors++;
535 kfree_skb(skb);
536 return -EINVAL;
537 }
538
539 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
540 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
541
542 skb_shinfo(skb)->gso_size = gso.gso_size;
543 if (skb_shinfo(skb)->gso_size == 0) {
544 tun->dev->stats.rx_frame_errors++;
545 kfree_skb(skb);
546 return -EINVAL;
547 }
548
549 /* Header must be checked, and gso_segs computed. */
550 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
551 skb_shinfo(skb)->gso_segs = 0;
552 }
553
554 netif_rx_ni(skb);
555
556 tun->dev->stats.rx_packets++;
557 tun->dev->stats.rx_bytes += len;
558
559 return count;
560 }
561
562 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
563 unsigned long count, loff_t pos)
564 {
565 struct tun_struct *tun = iocb->ki_filp->private_data;
566
567 if (!tun)
568 return -EBADFD;
569
570 DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
571
572 return tun_get_user(tun, (struct iovec *) iv, iov_length(iv, count));
573 }
574
575 /* Put packet to the user space buffer */
576 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
577 struct sk_buff *skb,
578 struct iovec *iv, int len)
579 {
580 struct tun_pi pi = { 0, skb->protocol };
581 ssize_t total = 0;
582
583 if (!(tun->flags & TUN_NO_PI)) {
584 if ((len -= sizeof(pi)) < 0)
585 return -EINVAL;
586
587 if (len < skb->len) {
588 /* Packet will be striped */
589 pi.flags |= TUN_PKT_STRIP;
590 }
591
592 if (memcpy_toiovec(iv, (void *) &pi, sizeof(pi)))
593 return -EFAULT;
594 total += sizeof(pi);
595 }
596
597 if (tun->flags & TUN_VNET_HDR) {
598 struct virtio_net_hdr gso = { 0 }; /* no info leak */
599 if ((len -= sizeof(gso)) < 0)
600 return -EINVAL;
601
602 if (skb_is_gso(skb)) {
603 struct skb_shared_info *sinfo = skb_shinfo(skb);
604
605 /* This is a hint as to how much should be linear. */
606 gso.hdr_len = skb_headlen(skb);
607 gso.gso_size = sinfo->gso_size;
608 if (sinfo->gso_type & SKB_GSO_TCPV4)
609 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
610 else if (sinfo->gso_type & SKB_GSO_TCPV6)
611 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
612 else
613 BUG();
614 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
615 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
616 } else
617 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
618
619 if (skb->ip_summed == CHECKSUM_PARTIAL) {
620 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
621 gso.csum_start = skb->csum_start - skb_headroom(skb);
622 gso.csum_offset = skb->csum_offset;
623 } /* else everything is zero */
624
625 if (unlikely(memcpy_toiovec(iv, (void *)&gso, sizeof(gso))))
626 return -EFAULT;
627 total += sizeof(gso);
628 }
629
630 len = min_t(int, skb->len, len);
631
632 skb_copy_datagram_iovec(skb, 0, iv, len);
633 total += len;
634
635 tun->dev->stats.tx_packets++;
636 tun->dev->stats.tx_bytes += len;
637
638 return total;
639 }
640
641 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
642 unsigned long count, loff_t pos)
643 {
644 struct file *file = iocb->ki_filp;
645 struct tun_struct *tun = file->private_data;
646 DECLARE_WAITQUEUE(wait, current);
647 struct sk_buff *skb;
648 ssize_t len, ret = 0;
649
650 if (!tun)
651 return -EBADFD;
652
653 DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
654
655 len = iov_length(iv, count);
656 if (len < 0)
657 return -EINVAL;
658
659 add_wait_queue(&tun->read_wait, &wait);
660 while (len) {
661 current->state = TASK_INTERRUPTIBLE;
662
663 /* Read frames from the queue */
664 if (!(skb=skb_dequeue(&tun->readq))) {
665 if (file->f_flags & O_NONBLOCK) {
666 ret = -EAGAIN;
667 break;
668 }
669 if (signal_pending(current)) {
670 ret = -ERESTARTSYS;
671 break;
672 }
673
674 /* Nothing to read, let's sleep */
675 schedule();
676 continue;
677 }
678 netif_wake_queue(tun->dev);
679
680 ret = tun_put_user(tun, skb, (struct iovec *) iv, len);
681 kfree_skb(skb);
682 break;
683 }
684
685 current->state = TASK_RUNNING;
686 remove_wait_queue(&tun->read_wait, &wait);
687
688 return ret;
689 }
690
691 static void tun_setup(struct net_device *dev)
692 {
693 struct tun_struct *tun = netdev_priv(dev);
694
695 skb_queue_head_init(&tun->readq);
696 init_waitqueue_head(&tun->read_wait);
697
698 tun->owner = -1;
699 tun->group = -1;
700
701 dev->ethtool_ops = &tun_ethtool_ops;
702 dev->destructor = free_netdev;
703 dev->features |= NETIF_F_NETNS_LOCAL;
704 }
705
706 static struct tun_struct *tun_get_by_name(struct tun_net *tn, const char *name)
707 {
708 struct tun_struct *tun;
709
710 ASSERT_RTNL();
711 list_for_each_entry(tun, &tn->dev_list, list) {
712 if (!strncmp(tun->dev->name, name, IFNAMSIZ))
713 return tun;
714 }
715
716 return NULL;
717 }
718
719 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
720 {
721 struct tun_net *tn;
722 struct tun_struct *tun;
723 struct net_device *dev;
724 const struct cred *cred = current_cred();
725 int err;
726
727 tn = net_generic(net, tun_net_id);
728 tun = tun_get_by_name(tn, ifr->ifr_name);
729 if (tun) {
730 if (tun->attached)
731 return -EBUSY;
732
733 /* Check permissions */
734 if (((tun->owner != -1 &&
735 cred->euid != tun->owner) ||
736 (tun->group != -1 &&
737 cred->egid != tun->group)) &&
738 !capable(CAP_NET_ADMIN)) {
739 return -EPERM;
740 }
741 }
742 else if (__dev_get_by_name(net, ifr->ifr_name))
743 return -EINVAL;
744 else {
745 char *name;
746 unsigned long flags = 0;
747
748 err = -EINVAL;
749
750 if (!capable(CAP_NET_ADMIN))
751 return -EPERM;
752
753 /* Set dev type */
754 if (ifr->ifr_flags & IFF_TUN) {
755 /* TUN device */
756 flags |= TUN_TUN_DEV;
757 name = "tun%d";
758 } else if (ifr->ifr_flags & IFF_TAP) {
759 /* TAP device */
760 flags |= TUN_TAP_DEV;
761 name = "tap%d";
762 } else
763 goto failed;
764
765 if (*ifr->ifr_name)
766 name = ifr->ifr_name;
767
768 dev = alloc_netdev(sizeof(struct tun_struct), name,
769 tun_setup);
770 if (!dev)
771 return -ENOMEM;
772
773 dev_net_set(dev, net);
774
775 tun = netdev_priv(dev);
776 tun->dev = dev;
777 tun->flags = flags;
778 tun->txflt.count = 0;
779
780 tun_net_init(dev);
781
782 if (strchr(dev->name, '%')) {
783 err = dev_alloc_name(dev, dev->name);
784 if (err < 0)
785 goto err_free_dev;
786 }
787
788 err = register_netdevice(tun->dev);
789 if (err < 0)
790 goto err_free_dev;
791
792 list_add(&tun->list, &tn->dev_list);
793 }
794
795 DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
796
797 if (ifr->ifr_flags & IFF_NO_PI)
798 tun->flags |= TUN_NO_PI;
799 else
800 tun->flags &= ~TUN_NO_PI;
801
802 if (ifr->ifr_flags & IFF_ONE_QUEUE)
803 tun->flags |= TUN_ONE_QUEUE;
804 else
805 tun->flags &= ~TUN_ONE_QUEUE;
806
807 if (ifr->ifr_flags & IFF_VNET_HDR)
808 tun->flags |= TUN_VNET_HDR;
809 else
810 tun->flags &= ~TUN_VNET_HDR;
811
812 file->private_data = tun;
813 tun->attached = 1;
814 get_net(dev_net(tun->dev));
815
816 /* Make sure persistent devices do not get stuck in
817 * xoff state.
818 */
819 if (netif_running(tun->dev))
820 netif_wake_queue(tun->dev);
821
822 strcpy(ifr->ifr_name, tun->dev->name);
823 return 0;
824
825 err_free_dev:
826 free_netdev(dev);
827 failed:
828 return err;
829 }
830
831 static int tun_get_iff(struct net *net, struct file *file, struct ifreq *ifr)
832 {
833 struct tun_struct *tun = file->private_data;
834
835 if (!tun)
836 return -EBADFD;
837
838 DBG(KERN_INFO "%s: tun_get_iff\n", tun->dev->name);
839
840 strcpy(ifr->ifr_name, tun->dev->name);
841
842 ifr->ifr_flags = 0;
843
844 if (ifr->ifr_flags & TUN_TUN_DEV)
845 ifr->ifr_flags |= IFF_TUN;
846 else
847 ifr->ifr_flags |= IFF_TAP;
848
849 if (tun->flags & TUN_NO_PI)
850 ifr->ifr_flags |= IFF_NO_PI;
851
852 if (tun->flags & TUN_ONE_QUEUE)
853 ifr->ifr_flags |= IFF_ONE_QUEUE;
854
855 if (tun->flags & TUN_VNET_HDR)
856 ifr->ifr_flags |= IFF_VNET_HDR;
857
858 return 0;
859 }
860
861 /* This is like a cut-down ethtool ops, except done via tun fd so no
862 * privs required. */
863 static int set_offload(struct net_device *dev, unsigned long arg)
864 {
865 unsigned int old_features, features;
866
867 old_features = dev->features;
868 /* Unset features, set them as we chew on the arg. */
869 features = (old_features & ~(NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST
870 |NETIF_F_TSO_ECN|NETIF_F_TSO|NETIF_F_TSO6));
871
872 if (arg & TUN_F_CSUM) {
873 features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
874 arg &= ~TUN_F_CSUM;
875
876 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
877 if (arg & TUN_F_TSO_ECN) {
878 features |= NETIF_F_TSO_ECN;
879 arg &= ~TUN_F_TSO_ECN;
880 }
881 if (arg & TUN_F_TSO4)
882 features |= NETIF_F_TSO;
883 if (arg & TUN_F_TSO6)
884 features |= NETIF_F_TSO6;
885 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
886 }
887 }
888
889 /* This gives the user a way to test for new features in future by
890 * trying to set them. */
891 if (arg)
892 return -EINVAL;
893
894 dev->features = features;
895 if (old_features != dev->features)
896 netdev_features_change(dev);
897
898 return 0;
899 }
900
901 static int tun_chr_ioctl(struct inode *inode, struct file *file,
902 unsigned int cmd, unsigned long arg)
903 {
904 struct tun_struct *tun = file->private_data;
905 void __user* argp = (void __user*)arg;
906 struct ifreq ifr;
907 int ret;
908
909 if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
910 if (copy_from_user(&ifr, argp, sizeof ifr))
911 return -EFAULT;
912
913 if (cmd == TUNSETIFF && !tun) {
914 int err;
915
916 ifr.ifr_name[IFNAMSIZ-1] = '\0';
917
918 rtnl_lock();
919 err = tun_set_iff(current->nsproxy->net_ns, file, &ifr);
920 rtnl_unlock();
921
922 if (err)
923 return err;
924
925 if (copy_to_user(argp, &ifr, sizeof(ifr)))
926 return -EFAULT;
927 return 0;
928 }
929
930 if (cmd == TUNGETFEATURES) {
931 /* Currently this just means: "what IFF flags are valid?".
932 * This is needed because we never checked for invalid flags on
933 * TUNSETIFF. */
934 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
935 IFF_VNET_HDR,
936 (unsigned int __user*)argp);
937 }
938
939 if (!tun)
940 return -EBADFD;
941
942 DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
943
944 switch (cmd) {
945 case TUNGETIFF:
946 ret = tun_get_iff(current->nsproxy->net_ns, file, &ifr);
947 if (ret)
948 return ret;
949
950 if (copy_to_user(argp, &ifr, sizeof(ifr)))
951 return -EFAULT;
952 break;
953
954 case TUNSETNOCSUM:
955 /* Disable/Enable checksum */
956 if (arg)
957 tun->flags |= TUN_NOCHECKSUM;
958 else
959 tun->flags &= ~TUN_NOCHECKSUM;
960
961 DBG(KERN_INFO "%s: checksum %s\n",
962 tun->dev->name, arg ? "disabled" : "enabled");
963 break;
964
965 case TUNSETPERSIST:
966 /* Disable/Enable persist mode */
967 if (arg)
968 tun->flags |= TUN_PERSIST;
969 else
970 tun->flags &= ~TUN_PERSIST;
971
972 DBG(KERN_INFO "%s: persist %s\n",
973 tun->dev->name, arg ? "enabled" : "disabled");
974 break;
975
976 case TUNSETOWNER:
977 /* Set owner of the device */
978 tun->owner = (uid_t) arg;
979
980 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
981 break;
982
983 case TUNSETGROUP:
984 /* Set group of the device */
985 tun->group= (gid_t) arg;
986
987 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group);
988 break;
989
990 case TUNSETLINK:
991 /* Only allow setting the type when the interface is down */
992 rtnl_lock();
993 if (tun->dev->flags & IFF_UP) {
994 DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
995 tun->dev->name);
996 ret = -EBUSY;
997 } else {
998 tun->dev->type = (int) arg;
999 DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
1000 ret = 0;
1001 }
1002 rtnl_unlock();
1003 return ret;
1004
1005 #ifdef TUN_DEBUG
1006 case TUNSETDEBUG:
1007 tun->debug = arg;
1008 break;
1009 #endif
1010 case TUNSETOFFLOAD:
1011 rtnl_lock();
1012 ret = set_offload(tun->dev, arg);
1013 rtnl_unlock();
1014 return ret;
1015
1016 case TUNSETTXFILTER:
1017 /* Can be set only for TAPs */
1018 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1019 return -EINVAL;
1020 rtnl_lock();
1021 ret = update_filter(&tun->txflt, (void __user *)arg);
1022 rtnl_unlock();
1023 return ret;
1024
1025 case SIOCGIFHWADDR:
1026 /* Get hw addres */
1027 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
1028 ifr.ifr_hwaddr.sa_family = tun->dev->type;
1029 if (copy_to_user(argp, &ifr, sizeof ifr))
1030 return -EFAULT;
1031 return 0;
1032
1033 case SIOCSIFHWADDR:
1034 /* Set hw address */
1035 DBG(KERN_DEBUG "%s: set hw address: %pM\n",
1036 tun->dev->name, ifr.ifr_hwaddr.sa_data);
1037
1038 rtnl_lock();
1039 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
1040 rtnl_unlock();
1041 return ret;
1042
1043 default:
1044 return -EINVAL;
1045 };
1046
1047 return 0;
1048 }
1049
1050 static int tun_chr_fasync(int fd, struct file *file, int on)
1051 {
1052 struct tun_struct *tun = file->private_data;
1053 int ret;
1054
1055 if (!tun)
1056 return -EBADFD;
1057
1058 DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
1059
1060 lock_kernel();
1061 if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
1062 goto out;
1063
1064 if (on) {
1065 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
1066 if (ret)
1067 goto out;
1068 tun->flags |= TUN_FASYNC;
1069 } else
1070 tun->flags &= ~TUN_FASYNC;
1071 ret = 0;
1072 out:
1073 unlock_kernel();
1074 return ret;
1075 }
1076
1077 static int tun_chr_open(struct inode *inode, struct file * file)
1078 {
1079 cycle_kernel_lock();
1080 DBG1(KERN_INFO "tunX: tun_chr_open\n");
1081 file->private_data = NULL;
1082 return 0;
1083 }
1084
1085 static int tun_chr_close(struct inode *inode, struct file *file)
1086 {
1087 struct tun_struct *tun = file->private_data;
1088
1089 if (!tun)
1090 return 0;
1091
1092 DBG(KERN_INFO "%s: tun_chr_close\n", tun->dev->name);
1093
1094 rtnl_lock();
1095
1096 /* Detach from net device */
1097 file->private_data = NULL;
1098 tun->attached = 0;
1099 put_net(dev_net(tun->dev));
1100
1101 /* Drop read queue */
1102 skb_queue_purge(&tun->readq);
1103
1104 if (!(tun->flags & TUN_PERSIST)) {
1105 list_del(&tun->list);
1106 unregister_netdevice(tun->dev);
1107 }
1108
1109 rtnl_unlock();
1110
1111 return 0;
1112 }
1113
1114 static const struct file_operations tun_fops = {
1115 .owner = THIS_MODULE,
1116 .llseek = no_llseek,
1117 .read = do_sync_read,
1118 .aio_read = tun_chr_aio_read,
1119 .write = do_sync_write,
1120 .aio_write = tun_chr_aio_write,
1121 .poll = tun_chr_poll,
1122 .ioctl = tun_chr_ioctl,
1123 .open = tun_chr_open,
1124 .release = tun_chr_close,
1125 .fasync = tun_chr_fasync
1126 };
1127
1128 static struct miscdevice tun_miscdev = {
1129 .minor = TUN_MINOR,
1130 .name = "tun",
1131 .fops = &tun_fops,
1132 };
1133
1134 /* ethtool interface */
1135
1136 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1137 {
1138 cmd->supported = 0;
1139 cmd->advertising = 0;
1140 cmd->speed = SPEED_10;
1141 cmd->duplex = DUPLEX_FULL;
1142 cmd->port = PORT_TP;
1143 cmd->phy_address = 0;
1144 cmd->transceiver = XCVR_INTERNAL;
1145 cmd->autoneg = AUTONEG_DISABLE;
1146 cmd->maxtxpkt = 0;
1147 cmd->maxrxpkt = 0;
1148 return 0;
1149 }
1150
1151 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
1152 {
1153 struct tun_struct *tun = netdev_priv(dev);
1154
1155 strcpy(info->driver, DRV_NAME);
1156 strcpy(info->version, DRV_VERSION);
1157 strcpy(info->fw_version, "N/A");
1158
1159 switch (tun->flags & TUN_TYPE_MASK) {
1160 case TUN_TUN_DEV:
1161 strcpy(info->bus_info, "tun");
1162 break;
1163 case TUN_TAP_DEV:
1164 strcpy(info->bus_info, "tap");
1165 break;
1166 }
1167 }
1168
1169 static u32 tun_get_msglevel(struct net_device *dev)
1170 {
1171 #ifdef TUN_DEBUG
1172 struct tun_struct *tun = netdev_priv(dev);
1173 return tun->debug;
1174 #else
1175 return -EOPNOTSUPP;
1176 #endif
1177 }
1178
1179 static void tun_set_msglevel(struct net_device *dev, u32 value)
1180 {
1181 #ifdef TUN_DEBUG
1182 struct tun_struct *tun = netdev_priv(dev);
1183 tun->debug = value;
1184 #endif
1185 }
1186
1187 static u32 tun_get_link(struct net_device *dev)
1188 {
1189 struct tun_struct *tun = netdev_priv(dev);
1190 return tun->attached;
1191 }
1192
1193 static u32 tun_get_rx_csum(struct net_device *dev)
1194 {
1195 struct tun_struct *tun = netdev_priv(dev);
1196 return (tun->flags & TUN_NOCHECKSUM) == 0;
1197 }
1198
1199 static int tun_set_rx_csum(struct net_device *dev, u32 data)
1200 {
1201 struct tun_struct *tun = netdev_priv(dev);
1202 if (data)
1203 tun->flags &= ~TUN_NOCHECKSUM;
1204 else
1205 tun->flags |= TUN_NOCHECKSUM;
1206 return 0;
1207 }
1208
1209 static const struct ethtool_ops tun_ethtool_ops = {
1210 .get_settings = tun_get_settings,
1211 .get_drvinfo = tun_get_drvinfo,
1212 .get_msglevel = tun_get_msglevel,
1213 .set_msglevel = tun_set_msglevel,
1214 .get_link = tun_get_link,
1215 .get_rx_csum = tun_get_rx_csum,
1216 .set_rx_csum = tun_set_rx_csum
1217 };
1218
1219 static int tun_init_net(struct net *net)
1220 {
1221 struct tun_net *tn;
1222
1223 tn = kmalloc(sizeof(*tn), GFP_KERNEL);
1224 if (tn == NULL)
1225 return -ENOMEM;
1226
1227 INIT_LIST_HEAD(&tn->dev_list);
1228
1229 if (net_assign_generic(net, tun_net_id, tn)) {
1230 kfree(tn);
1231 return -ENOMEM;
1232 }
1233
1234 return 0;
1235 }
1236
1237 static void tun_exit_net(struct net *net)
1238 {
1239 struct tun_net *tn;
1240 struct tun_struct *tun, *nxt;
1241
1242 tn = net_generic(net, tun_net_id);
1243
1244 rtnl_lock();
1245 list_for_each_entry_safe(tun, nxt, &tn->dev_list, list) {
1246 DBG(KERN_INFO "%s cleaned up\n", tun->dev->name);
1247 unregister_netdevice(tun->dev);
1248 }
1249 rtnl_unlock();
1250
1251 kfree(tn);
1252 }
1253
1254 static struct pernet_operations tun_net_ops = {
1255 .init = tun_init_net,
1256 .exit = tun_exit_net,
1257 };
1258
1259 static int __init tun_init(void)
1260 {
1261 int ret = 0;
1262
1263 printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
1264 printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
1265
1266 ret = register_pernet_gen_device(&tun_net_id, &tun_net_ops);
1267 if (ret) {
1268 printk(KERN_ERR "tun: Can't register pernet ops\n");
1269 goto err_pernet;
1270 }
1271
1272 ret = misc_register(&tun_miscdev);
1273 if (ret) {
1274 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
1275 goto err_misc;
1276 }
1277 return 0;
1278
1279 err_misc:
1280 unregister_pernet_gen_device(tun_net_id, &tun_net_ops);
1281 err_pernet:
1282 return ret;
1283 }
1284
1285 static void tun_cleanup(void)
1286 {
1287 misc_deregister(&tun_miscdev);
1288 unregister_pernet_gen_device(tun_net_id, &tun_net_ops);
1289 }
1290
1291 module_init(tun_init);
1292 module_exit(tun_cleanup);
1293 MODULE_DESCRIPTION(DRV_DESCRIPTION);
1294 MODULE_AUTHOR(DRV_COPYRIGHT);
1295 MODULE_LICENSE("GPL");
1296 MODULE_ALIAS_MISCDEV(TUN_MINOR);
Support for the Chinese Samsung S3C2440 based development boards