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drivers/misc/Makefile, Kconfig: cleanup
[linux-2.6/mini2440.git] / drivers / net / tun.c
blob33b6d1b122fb59fdadfdd2f156a0596f37efcc25
1 /*
2 * TUN - Universal TUN/TAP device driver.
3 * Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $
16 */
17
18 /*
19 * Changes:
20 *
21 * Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
22 * Add TUNSETLINK ioctl to set the link encapsulation
23 *
24 * Mark Smith <markzzzsmith@yahoo.com.au>
25 * Use random_ether_addr() for tap MAC address.
26 *
27 * Harald Roelle <harald.roelle@ifi.lmu.de> 2004/04/20
28 * Fixes in packet dropping, queue length setting and queue wakeup.
29 * Increased default tx queue length.
30 * Added ethtool API.
31 * Minor cleanups
32 *
33 * Daniel Podlejski <underley@underley.eu.org>
34 * Modifications for 2.3.99-pre5 kernel.
35 */
36
37 #define DRV_NAME "tun"
38 #define DRV_VERSION "1.6"
39 #define DRV_DESCRIPTION "Universal TUN/TAP device driver"
40 #define DRV_COPYRIGHT "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>"
41
42 #include <linux/module.h>
43 #include <linux/errno.h>
44 #include <linux/kernel.h>
45 #include <linux/major.h>
46 #include <linux/slab.h>
47 #include <linux/smp_lock.h>
48 #include <linux/poll.h>
49 #include <linux/fcntl.h>
50 #include <linux/init.h>
51 #include <linux/skbuff.h>
52 #include <linux/netdevice.h>
53 #include <linux/etherdevice.h>
54 #include <linux/miscdevice.h>
55 #include <linux/ethtool.h>
56 #include <linux/rtnetlink.h>
57 #include <linux/if.h>
58 #include <linux/if_arp.h>
59 #include <linux/if_ether.h>
60 #include <linux/if_tun.h>
61 #include <linux/crc32.h>
62 #include <linux/nsproxy.h>
63 #include <linux/virtio_net.h>
64 #include <net/net_namespace.h>
65 #include <net/netns/generic.h>
66
67 #include <asm/system.h>
68 #include <asm/uaccess.h>
69
70 /* Uncomment to enable debugging */
71 /* #define TUN_DEBUG 1 */
72
73 #ifdef TUN_DEBUG
74 static int debug;
75
76 #define DBG if(tun->debug)printk
77 #define DBG1 if(debug==2)printk
78 #else
79 #define DBG( a... )
80 #define DBG1( a... )
81 #endif
82
83 #define FLT_EXACT_COUNT 8
84 struct tap_filter {
85 unsigned int count; /* Number of addrs. Zero means disabled */
86 u32 mask[2]; /* Mask of the hashed addrs */
87 unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN];
88 };
89
90 struct tun_struct {
91 struct list_head list;
92 unsigned int flags;
93 int attached;
94 uid_t owner;
95 gid_t group;
96
97 wait_queue_head_t read_wait;
98 struct sk_buff_head readq;
99
100 struct net_device *dev;
101 struct fasync_struct *fasync;
102
103 struct tap_filter txflt;
104
105 #ifdef TUN_DEBUG
106 int debug;
107 #endif
108 };
109
110 /* TAP filterting */
111 static void addr_hash_set(u32 *mask, const u8 *addr)
112 {
113 int n = ether_crc(ETH_ALEN, addr) >> 26;
114 mask[n >> 5] |= (1 << (n & 31));
115 }
116
117 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
118 {
119 int n = ether_crc(ETH_ALEN, addr) >> 26;
120 return mask[n >> 5] & (1 << (n & 31));
121 }
122
123 static int update_filter(struct tap_filter *filter, void __user *arg)
124 {
125 struct { u8 u[ETH_ALEN]; } *addr;
126 struct tun_filter uf;
127 int err, alen, n, nexact;
128
129 if (copy_from_user(&uf, arg, sizeof(uf)))
130 return -EFAULT;
131
132 if (!uf.count) {
133 /* Disabled */
134 filter->count = 0;
135 return 0;
136 }
137
138 alen = ETH_ALEN * uf.count;
139 addr = kmalloc(alen, GFP_KERNEL);
140 if (!addr)
141 return -ENOMEM;
142
143 if (copy_from_user(addr, arg + sizeof(uf), alen)) {
144 err = -EFAULT;
145 goto done;
146 }
147
148 /* The filter is updated without holding any locks. Which is
149 * perfectly safe. We disable it first and in the worst
150 * case we'll accept a few undesired packets. */
151 filter->count = 0;
152 wmb();
153
154 /* Use first set of addresses as an exact filter */
155 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
156 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
157
158 nexact = n;
159
160 /* The rest is hashed */
161 memset(filter->mask, 0, sizeof(filter->mask));
162 for (; n < uf.count; n++)
163 addr_hash_set(filter->mask, addr[n].u);
164
165 /* For ALLMULTI just set the mask to all ones.
166 * This overrides the mask populated above. */
167 if ((uf.flags & TUN_FLT_ALLMULTI))
168 memset(filter->mask, ~0, sizeof(filter->mask));
169
170 /* Now enable the filter */
171 wmb();
172 filter->count = nexact;
173
174 /* Return the number of exact filters */
175 err = nexact;
176
177 done:
178 kfree(addr);
179 return err;
180 }
181
182 /* Returns: 0 - drop, !=0 - accept */
183 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
184 {
185 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
186 * at this point. */
187 struct ethhdr *eh = (struct ethhdr *) skb->data;
188 int i;
189
190 /* Exact match */
191 for (i = 0; i < filter->count; i++)
192 if (!compare_ether_addr(eh->h_dest, filter->addr[i]))
193 return 1;
194
195 /* Inexact match (multicast only) */
196 if (is_multicast_ether_addr(eh->h_dest))
197 return addr_hash_test(filter->mask, eh->h_dest);
198
199 return 0;
200 }
201
202 /*
203 * Checks whether the packet is accepted or not.
204 * Returns: 0 - drop, !=0 - accept
205 */
206 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
207 {
208 if (!filter->count)
209 return 1;
210
211 return run_filter(filter, skb);
212 }
213
214 /* Network device part of the driver */
215
216 static unsigned int tun_net_id;
217 struct tun_net {
218 struct list_head dev_list;
219 };
220
221 static const struct ethtool_ops tun_ethtool_ops;
222
223 /* Net device open. */
224 static int tun_net_open(struct net_device *dev)
225 {
226 netif_start_queue(dev);
227 return 0;
228 }
229
230 /* Net device close. */
231 static int tun_net_close(struct net_device *dev)
232 {
233 netif_stop_queue(dev);
234 return 0;
235 }
236
237 /* Net device start xmit */
238 static int tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
239 {
240 struct tun_struct *tun = netdev_priv(dev);
241
242 DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len);
243
244 /* Drop packet if interface is not attached */
245 if (!tun->attached)
246 goto drop;
247
248 /* Drop if the filter does not like it.
249 * This is a noop if the filter is disabled.
250 * Filter can be enabled only for the TAP devices. */
251 if (!check_filter(&tun->txflt, skb))
252 goto drop;
253
254 if (skb_queue_len(&tun->readq) >= dev->tx_queue_len) {
255 if (!(tun->flags & TUN_ONE_QUEUE)) {
256 /* Normal queueing mode. */
257 /* Packet scheduler handles dropping of further packets. */
258 netif_stop_queue(dev);
259
260 /* We won't see all dropped packets individually, so overrun
261 * error is more appropriate. */
262 dev->stats.tx_fifo_errors++;
263 } else {
264 /* Single queue mode.
265 * Driver handles dropping of all packets itself. */
266 goto drop;
267 }
268 }
269
270 /* Enqueue packet */
271 skb_queue_tail(&tun->readq, skb);
272 dev->trans_start = jiffies;
273
274 /* Notify and wake up reader process */
275 if (tun->flags & TUN_FASYNC)
276 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
277 wake_up_interruptible(&tun->read_wait);
278 return 0;
279
280 drop:
281 dev->stats.tx_dropped++;
282 kfree_skb(skb);
283 return 0;
284 }
285
286 static void tun_net_mclist(struct net_device *dev)
287 {
288 /*
289 * This callback is supposed to deal with mc filter in
290 * _rx_ path and has nothing to do with the _tx_ path.
291 * In rx path we always accept everything userspace gives us.
292 */
293 return;
294 }
295
296 #define MIN_MTU 68
297 #define MAX_MTU 65535
298
299 static int
300 tun_net_change_mtu(struct net_device *dev, int new_mtu)
301 {
302 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
303 return -EINVAL;
304 dev->mtu = new_mtu;
305 return 0;
306 }
307
308 /* Initialize net device. */
309 static void tun_net_init(struct net_device *dev)
310 {
311 struct tun_struct *tun = netdev_priv(dev);
312
313 switch (tun->flags & TUN_TYPE_MASK) {
314 case TUN_TUN_DEV:
315 /* Point-to-Point TUN Device */
316 dev->hard_header_len = 0;
317 dev->addr_len = 0;
318 dev->mtu = 1500;
319 dev->change_mtu = tun_net_change_mtu;
320
321 /* Zero header length */
322 dev->type = ARPHRD_NONE;
323 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
324 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
325 break;
326
327 case TUN_TAP_DEV:
328 /* Ethernet TAP Device */
329 ether_setup(dev);
330 dev->change_mtu = tun_net_change_mtu;
331 dev->set_multicast_list = tun_net_mclist;
332
333 random_ether_addr(dev->dev_addr);
334
335 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
336 break;
337 }
338 }
339
340 /* Character device part */
341
342 /* Poll */
343 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
344 {
345 struct tun_struct *tun = file->private_data;
346 unsigned int mask = POLLOUT | POLLWRNORM;
347
348 if (!tun)
349 return -EBADFD;
350
351 DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
352
353 poll_wait(file, &tun->read_wait, wait);
354
355 if (!skb_queue_empty(&tun->readq))
356 mask |= POLLIN | POLLRDNORM;
357
358 return mask;
359 }
360
361 /* prepad is the amount to reserve at front. len is length after that.
362 * linear is a hint as to how much to copy (usually headers). */
363 static struct sk_buff *tun_alloc_skb(size_t prepad, size_t len, size_t linear,
364 gfp_t gfp)
365 {
366 struct sk_buff *skb;
367 unsigned int i;
368
369 skb = alloc_skb(prepad + len, gfp|__GFP_NOWARN);
370 if (skb) {
371 skb_reserve(skb, prepad);
372 skb_put(skb, len);
373 return skb;
374 }
375
376 /* Under a page? Don't bother with paged skb. */
377 if (prepad + len < PAGE_SIZE)
378 return NULL;
379
380 /* Start with a normal skb, and add pages. */
381 skb = alloc_skb(prepad + linear, gfp);
382 if (!skb)
383 return NULL;
384
385 skb_reserve(skb, prepad);
386 skb_put(skb, linear);
387
388 len -= linear;
389
390 for (i = 0; i < MAX_SKB_FRAGS; i++) {
391 skb_frag_t *f = &skb_shinfo(skb)->frags[i];
392
393 f->page = alloc_page(gfp|__GFP_ZERO);
394 if (!f->page)
395 break;
396
397 f->page_offset = 0;
398 f->size = PAGE_SIZE;
399
400 skb->data_len += PAGE_SIZE;
401 skb->len += PAGE_SIZE;
402 skb->truesize += PAGE_SIZE;
403 skb_shinfo(skb)->nr_frags++;
404
405 if (len < PAGE_SIZE) {
406 len = 0;
407 break;
408 }
409 len -= PAGE_SIZE;
410 }
411
412 /* Too large, or alloc fail? */
413 if (unlikely(len)) {
414 kfree_skb(skb);
415 skb = NULL;
416 }
417
418 return skb;
419 }
420
421 /* Get packet from user space buffer */
422 static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, size_t count)
423 {
424 struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) };
425 struct sk_buff *skb;
426 size_t len = count, align = 0;
427 struct virtio_net_hdr gso = { 0 };
428
429 if (!(tun->flags & TUN_NO_PI)) {
430 if ((len -= sizeof(pi)) > count)
431 return -EINVAL;
432
433 if(memcpy_fromiovec((void *)&pi, iv, sizeof(pi)))
434 return -EFAULT;
435 }
436
437 if (tun->flags & TUN_VNET_HDR) {
438 if ((len -= sizeof(gso)) > count)
439 return -EINVAL;
440
441 if (memcpy_fromiovec((void *)&gso, iv, sizeof(gso)))
442 return -EFAULT;
443
444 if (gso.hdr_len > len)
445 return -EINVAL;
446 }
447
448 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
449 align = NET_IP_ALIGN;
450 if (unlikely(len < ETH_HLEN))
451 return -EINVAL;
452 }
453
454 if (!(skb = tun_alloc_skb(align, len, gso.hdr_len, GFP_KERNEL))) {
455 tun->dev->stats.rx_dropped++;
456 return -ENOMEM;
457 }
458
459 if (skb_copy_datagram_from_iovec(skb, 0, iv, len)) {
460 tun->dev->stats.rx_dropped++;
461 kfree_skb(skb);
462 return -EFAULT;
463 }
464
465 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
466 if (!skb_partial_csum_set(skb, gso.csum_start,
467 gso.csum_offset)) {
468 tun->dev->stats.rx_frame_errors++;
469 kfree_skb(skb);
470 return -EINVAL;
471 }
472 } else if (tun->flags & TUN_NOCHECKSUM)
473 skb->ip_summed = CHECKSUM_UNNECESSARY;
474
475 switch (tun->flags & TUN_TYPE_MASK) {
476 case TUN_TUN_DEV:
477 if (tun->flags & TUN_NO_PI) {
478 switch (skb->data[0] & 0xf0) {
479 case 0x40:
480 pi.proto = htons(ETH_P_IP);
481 break;
482 case 0x60:
483 pi.proto = htons(ETH_P_IPV6);
484 break;
485 default:
486 tun->dev->stats.rx_dropped++;
487 kfree_skb(skb);
488 return -EINVAL;
489 }
490 }
491
492 skb_reset_mac_header(skb);
493 skb->protocol = pi.proto;
494 skb->dev = tun->dev;
495 break;
496 case TUN_TAP_DEV:
497 skb->protocol = eth_type_trans(skb, tun->dev);
498 break;
499 };
500
501 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
502 pr_debug("GSO!\n");
503 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
504 case VIRTIO_NET_HDR_GSO_TCPV4:
505 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
506 break;
507 case VIRTIO_NET_HDR_GSO_TCPV6:
508 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
509 break;
510 default:
511 tun->dev->stats.rx_frame_errors++;
512 kfree_skb(skb);
513 return -EINVAL;
514 }
515
516 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
517 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
518
519 skb_shinfo(skb)->gso_size = gso.gso_size;
520 if (skb_shinfo(skb)->gso_size == 0) {
521 tun->dev->stats.rx_frame_errors++;
522 kfree_skb(skb);
523 return -EINVAL;
524 }
525
526 /* Header must be checked, and gso_segs computed. */
527 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
528 skb_shinfo(skb)->gso_segs = 0;
529 }
530
531 netif_rx_ni(skb);
532 tun->dev->last_rx = jiffies;
533
534 tun->dev->stats.rx_packets++;
535 tun->dev->stats.rx_bytes += len;
536
537 return count;
538 }
539
540 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
541 unsigned long count, loff_t pos)
542 {
543 struct tun_struct *tun = iocb->ki_filp->private_data;
544
545 if (!tun)
546 return -EBADFD;
547
548 DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
549
550 return tun_get_user(tun, (struct iovec *) iv, iov_length(iv, count));
551 }
552
553 /* Put packet to the user space buffer */
554 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
555 struct sk_buff *skb,
556 struct iovec *iv, int len)
557 {
558 struct tun_pi pi = { 0, skb->protocol };
559 ssize_t total = 0;
560
561 if (!(tun->flags & TUN_NO_PI)) {
562 if ((len -= sizeof(pi)) < 0)
563 return -EINVAL;
564
565 if (len < skb->len) {
566 /* Packet will be striped */
567 pi.flags |= TUN_PKT_STRIP;
568 }
569
570 if (memcpy_toiovec(iv, (void *) &pi, sizeof(pi)))
571 return -EFAULT;
572 total += sizeof(pi);
573 }
574
575 if (tun->flags & TUN_VNET_HDR) {
576 struct virtio_net_hdr gso = { 0 }; /* no info leak */
577 if ((len -= sizeof(gso)) < 0)
578 return -EINVAL;
579
580 if (skb_is_gso(skb)) {
581 struct skb_shared_info *sinfo = skb_shinfo(skb);
582
583 /* This is a hint as to how much should be linear. */
584 gso.hdr_len = skb_headlen(skb);
585 gso.gso_size = sinfo->gso_size;
586 if (sinfo->gso_type & SKB_GSO_TCPV4)
587 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
588 else if (sinfo->gso_type & SKB_GSO_TCPV6)
589 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
590 else
591 BUG();
592 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
593 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
594 } else
595 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
596
597 if (skb->ip_summed == CHECKSUM_PARTIAL) {
598 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
599 gso.csum_start = skb->csum_start - skb_headroom(skb);
600 gso.csum_offset = skb->csum_offset;
601 } /* else everything is zero */
602
603 if (unlikely(memcpy_toiovec(iv, (void *)&gso, sizeof(gso))))
604 return -EFAULT;
605 total += sizeof(gso);
606 }
607
608 len = min_t(int, skb->len, len);
609
610 skb_copy_datagram_iovec(skb, 0, iv, len);
611 total += len;
612
613 tun->dev->stats.tx_packets++;
614 tun->dev->stats.tx_bytes += len;
615
616 return total;
617 }
618
619 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
620 unsigned long count, loff_t pos)
621 {
622 struct file *file = iocb->ki_filp;
623 struct tun_struct *tun = file->private_data;
624 DECLARE_WAITQUEUE(wait, current);
625 struct sk_buff *skb;
626 ssize_t len, ret = 0;
627
628 if (!tun)
629 return -EBADFD;
630
631 DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
632
633 len = iov_length(iv, count);
634 if (len < 0)
635 return -EINVAL;
636
637 add_wait_queue(&tun->read_wait, &wait);
638 while (len) {
639 current->state = TASK_INTERRUPTIBLE;
640
641 /* Read frames from the queue */
642 if (!(skb=skb_dequeue(&tun->readq))) {
643 if (file->f_flags & O_NONBLOCK) {
644 ret = -EAGAIN;
645 break;
646 }
647 if (signal_pending(current)) {
648 ret = -ERESTARTSYS;
649 break;
650 }
651
652 /* Nothing to read, let's sleep */
653 schedule();
654 continue;
655 }
656 netif_wake_queue(tun->dev);
657
658 ret = tun_put_user(tun, skb, (struct iovec *) iv, len);
659 kfree_skb(skb);
660 break;
661 }
662
663 current->state = TASK_RUNNING;
664 remove_wait_queue(&tun->read_wait, &wait);
665
666 return ret;
667 }
668
669 static void tun_setup(struct net_device *dev)
670 {
671 struct tun_struct *tun = netdev_priv(dev);
672
673 skb_queue_head_init(&tun->readq);
674 init_waitqueue_head(&tun->read_wait);
675
676 tun->owner = -1;
677 tun->group = -1;
678
679 dev->open = tun_net_open;
680 dev->hard_start_xmit = tun_net_xmit;
681 dev->stop = tun_net_close;
682 dev->ethtool_ops = &tun_ethtool_ops;
683 dev->destructor = free_netdev;
684 dev->features |= NETIF_F_NETNS_LOCAL;
685 }
686
687 static struct tun_struct *tun_get_by_name(struct tun_net *tn, const char *name)
688 {
689 struct tun_struct *tun;
690
691 ASSERT_RTNL();
692 list_for_each_entry(tun, &tn->dev_list, list) {
693 if (!strncmp(tun->dev->name, name, IFNAMSIZ))
694 return tun;
695 }
696
697 return NULL;
698 }
699
700 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
701 {
702 struct tun_net *tn;
703 struct tun_struct *tun;
704 struct net_device *dev;
705 int err;
706
707 tn = net_generic(net, tun_net_id);
708 tun = tun_get_by_name(tn, ifr->ifr_name);
709 if (tun) {
710 if (tun->attached)
711 return -EBUSY;
712
713 /* Check permissions */
714 if (((tun->owner != -1 &&
715 current->euid != tun->owner) ||
716 (tun->group != -1 &&
717 current->egid != tun->group)) &&
718 !capable(CAP_NET_ADMIN))
719 return -EPERM;
720 }
721 else if (__dev_get_by_name(net, ifr->ifr_name))
722 return -EINVAL;
723 else {
724 char *name;
725 unsigned long flags = 0;
726
727 err = -EINVAL;
728
729 if (!capable(CAP_NET_ADMIN))
730 return -EPERM;
731
732 /* Set dev type */
733 if (ifr->ifr_flags & IFF_TUN) {
734 /* TUN device */
735 flags |= TUN_TUN_DEV;
736 name = "tun%d";
737 } else if (ifr->ifr_flags & IFF_TAP) {
738 /* TAP device */
739 flags |= TUN_TAP_DEV;
740 name = "tap%d";
741 } else
742 goto failed;
743
744 if (*ifr->ifr_name)
745 name = ifr->ifr_name;
746
747 dev = alloc_netdev(sizeof(struct tun_struct), name,
748 tun_setup);
749 if (!dev)
750 return -ENOMEM;
751
752 dev_net_set(dev, net);
753 tun = netdev_priv(dev);
754 tun->dev = dev;
755 tun->flags = flags;
756 tun->txflt.count = 0;
757
758 tun_net_init(dev);
759
760 if (strchr(dev->name, '%')) {
761 err = dev_alloc_name(dev, dev->name);
762 if (err < 0)
763 goto err_free_dev;
764 }
765
766 err = register_netdevice(tun->dev);
767 if (err < 0)
768 goto err_free_dev;
769
770 list_add(&tun->list, &tn->dev_list);
771 }
772
773 DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
774
775 if (ifr->ifr_flags & IFF_NO_PI)
776 tun->flags |= TUN_NO_PI;
777 else
778 tun->flags &= ~TUN_NO_PI;
779
780 if (ifr->ifr_flags & IFF_ONE_QUEUE)
781 tun->flags |= TUN_ONE_QUEUE;
782 else
783 tun->flags &= ~TUN_ONE_QUEUE;
784
785 if (ifr->ifr_flags & IFF_VNET_HDR)
786 tun->flags |= TUN_VNET_HDR;
787 else
788 tun->flags &= ~TUN_VNET_HDR;
789
790 file->private_data = tun;
791 tun->attached = 1;
792 get_net(dev_net(tun->dev));
793
794 /* Make sure persistent devices do not get stuck in
795 * xoff state.
796 */
797 if (netif_running(tun->dev))
798 netif_wake_queue(tun->dev);
799
800 strcpy(ifr->ifr_name, tun->dev->name);
801 return 0;
802
803 err_free_dev:
804 free_netdev(dev);
805 failed:
806 return err;
807 }
808
809 static int tun_get_iff(struct net *net, struct file *file, struct ifreq *ifr)
810 {
811 struct tun_struct *tun = file->private_data;
812
813 if (!tun)
814 return -EBADFD;
815
816 DBG(KERN_INFO "%s: tun_get_iff\n", tun->dev->name);
817
818 strcpy(ifr->ifr_name, tun->dev->name);
819
820 ifr->ifr_flags = 0;
821
822 if (ifr->ifr_flags & TUN_TUN_DEV)
823 ifr->ifr_flags |= IFF_TUN;
824 else
825 ifr->ifr_flags |= IFF_TAP;
826
827 if (tun->flags & TUN_NO_PI)
828 ifr->ifr_flags |= IFF_NO_PI;
829
830 if (tun->flags & TUN_ONE_QUEUE)
831 ifr->ifr_flags |= IFF_ONE_QUEUE;
832
833 if (tun->flags & TUN_VNET_HDR)
834 ifr->ifr_flags |= IFF_VNET_HDR;
835
836 return 0;
837 }
838
839 /* This is like a cut-down ethtool ops, except done via tun fd so no
840 * privs required. */
841 static int set_offload(struct net_device *dev, unsigned long arg)
842 {
843 unsigned int old_features, features;
844
845 old_features = dev->features;
846 /* Unset features, set them as we chew on the arg. */
847 features = (old_features & ~(NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST
848 |NETIF_F_TSO_ECN|NETIF_F_TSO|NETIF_F_TSO6));
849
850 if (arg & TUN_F_CSUM) {
851 features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
852 arg &= ~TUN_F_CSUM;
853
854 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
855 if (arg & TUN_F_TSO_ECN) {
856 features |= NETIF_F_TSO_ECN;
857 arg &= ~TUN_F_TSO_ECN;
858 }
859 if (arg & TUN_F_TSO4)
860 features |= NETIF_F_TSO;
861 if (arg & TUN_F_TSO6)
862 features |= NETIF_F_TSO6;
863 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
864 }
865 }
866
867 /* This gives the user a way to test for new features in future by
868 * trying to set them. */
869 if (arg)
870 return -EINVAL;
871
872 dev->features = features;
873 if (old_features != dev->features)
874 netdev_features_change(dev);
875
876 return 0;
877 }
878
879 static int tun_chr_ioctl(struct inode *inode, struct file *file,
880 unsigned int cmd, unsigned long arg)
881 {
882 struct tun_struct *tun = file->private_data;
883 void __user* argp = (void __user*)arg;
884 struct ifreq ifr;
885 int ret;
886 DECLARE_MAC_BUF(mac);
887
888 if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
889 if (copy_from_user(&ifr, argp, sizeof ifr))
890 return -EFAULT;
891
892 if (cmd == TUNSETIFF && !tun) {
893 int err;
894
895 ifr.ifr_name[IFNAMSIZ-1] = '\0';
896
897 rtnl_lock();
898 err = tun_set_iff(current->nsproxy->net_ns, file, &ifr);
899 rtnl_unlock();
900
901 if (err)
902 return err;
903
904 if (copy_to_user(argp, &ifr, sizeof(ifr)))
905 return -EFAULT;
906 return 0;
907 }
908
909 if (cmd == TUNGETFEATURES) {
910 /* Currently this just means: "what IFF flags are valid?".
911 * This is needed because we never checked for invalid flags on
912 * TUNSETIFF. */
913 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
914 IFF_VNET_HDR,
915 (unsigned int __user*)argp);
916 }
917
918 if (!tun)
919 return -EBADFD;
920
921 DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
922
923 switch (cmd) {
924 case TUNGETIFF:
925 ret = tun_get_iff(current->nsproxy->net_ns, file, &ifr);
926 if (ret)
927 return ret;
928
929 if (copy_to_user(argp, &ifr, sizeof(ifr)))
930 return -EFAULT;
931 break;
932
933 case TUNSETNOCSUM:
934 /* Disable/Enable checksum */
935 if (arg)
936 tun->flags |= TUN_NOCHECKSUM;
937 else
938 tun->flags &= ~TUN_NOCHECKSUM;
939
940 DBG(KERN_INFO "%s: checksum %s\n",
941 tun->dev->name, arg ? "disabled" : "enabled");
942 break;
943
944 case TUNSETPERSIST:
945 /* Disable/Enable persist mode */
946 if (arg)
947 tun->flags |= TUN_PERSIST;
948 else
949 tun->flags &= ~TUN_PERSIST;
950
951 DBG(KERN_INFO "%s: persist %s\n",
952 tun->dev->name, arg ? "enabled" : "disabled");
953 break;
954
955 case TUNSETOWNER:
956 /* Set owner of the device */
957 tun->owner = (uid_t) arg;
958
959 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
960 break;
961
962 case TUNSETGROUP:
963 /* Set group of the device */
964 tun->group= (gid_t) arg;
965
966 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group);
967 break;
968
969 case TUNSETLINK:
970 /* Only allow setting the type when the interface is down */
971 rtnl_lock();
972 if (tun->dev->flags & IFF_UP) {
973 DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
974 tun->dev->name);
975 ret = -EBUSY;
976 } else {
977 tun->dev->type = (int) arg;
978 DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
979 ret = 0;
980 }
981 rtnl_unlock();
982 return ret;
983
984 #ifdef TUN_DEBUG
985 case TUNSETDEBUG:
986 tun->debug = arg;
987 break;
988 #endif
989 case TUNSETOFFLOAD:
990 rtnl_lock();
991 ret = set_offload(tun->dev, arg);
992 rtnl_unlock();
993 return ret;
994
995 case TUNSETTXFILTER:
996 /* Can be set only for TAPs */
997 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
998 return -EINVAL;
999 rtnl_lock();
1000 ret = update_filter(&tun->txflt, (void __user *)arg);
1001 rtnl_unlock();
1002 return ret;
1003
1004 case SIOCGIFHWADDR:
1005 /* Get hw addres */
1006 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
1007 ifr.ifr_hwaddr.sa_family = tun->dev->type;
1008 if (copy_to_user(argp, &ifr, sizeof ifr))
1009 return -EFAULT;
1010 return 0;
1011
1012 case SIOCSIFHWADDR:
1013 /* Set hw address */
1014 DBG(KERN_DEBUG "%s: set hw address: %s\n",
1015 tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data));
1016
1017 rtnl_lock();
1018 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
1019 rtnl_unlock();
1020 return ret;
1021
1022 default:
1023 return -EINVAL;
1024 };
1025
1026 return 0;
1027 }
1028
1029 static int tun_chr_fasync(int fd, struct file *file, int on)
1030 {
1031 struct tun_struct *tun = file->private_data;
1032 int ret;
1033
1034 if (!tun)
1035 return -EBADFD;
1036
1037 DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
1038
1039 lock_kernel();
1040 if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
1041 goto out;
1042
1043 if (on) {
1044 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
1045 if (ret)
1046 goto out;
1047 tun->flags |= TUN_FASYNC;
1048 } else
1049 tun->flags &= ~TUN_FASYNC;
1050 ret = 0;
1051 out:
1052 unlock_kernel();
1053 return ret;
1054 }
1055
1056 static int tun_chr_open(struct inode *inode, struct file * file)
1057 {
1058 cycle_kernel_lock();
1059 DBG1(KERN_INFO "tunX: tun_chr_open\n");
1060 file->private_data = NULL;
1061 return 0;
1062 }
1063
1064 static int tun_chr_close(struct inode *inode, struct file *file)
1065 {
1066 struct tun_struct *tun = file->private_data;
1067
1068 if (!tun)
1069 return 0;
1070
1071 DBG(KERN_INFO "%s: tun_chr_close\n", tun->dev->name);
1072
1073 rtnl_lock();
1074
1075 /* Detach from net device */
1076 file->private_data = NULL;
1077 tun->attached = 0;
1078 put_net(dev_net(tun->dev));
1079
1080 /* Drop read queue */
1081 skb_queue_purge(&tun->readq);
1082
1083 if (!(tun->flags & TUN_PERSIST)) {
1084 list_del(&tun->list);
1085 unregister_netdevice(tun->dev);
1086 }
1087
1088 rtnl_unlock();
1089
1090 return 0;
1091 }
1092
1093 static const struct file_operations tun_fops = {
1094 .owner = THIS_MODULE,
1095 .llseek = no_llseek,
1096 .read = do_sync_read,
1097 .aio_read = tun_chr_aio_read,
1098 .write = do_sync_write,
1099 .aio_write = tun_chr_aio_write,
1100 .poll = tun_chr_poll,
1101 .ioctl = tun_chr_ioctl,
1102 .open = tun_chr_open,
1103 .release = tun_chr_close,
1104 .fasync = tun_chr_fasync
1105 };
1106
1107 static struct miscdevice tun_miscdev = {
1108 .minor = TUN_MINOR,
1109 .name = "tun",
1110 .fops = &tun_fops,
1111 };
1112
1113 /* ethtool interface */
1114
1115 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1116 {
1117 cmd->supported = 0;
1118 cmd->advertising = 0;
1119 cmd->speed = SPEED_10;
1120 cmd->duplex = DUPLEX_FULL;
1121 cmd->port = PORT_TP;
1122 cmd->phy_address = 0;
1123 cmd->transceiver = XCVR_INTERNAL;
1124 cmd->autoneg = AUTONEG_DISABLE;
1125 cmd->maxtxpkt = 0;
1126 cmd->maxrxpkt = 0;
1127 return 0;
1128 }
1129
1130 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
1131 {
1132 struct tun_struct *tun = netdev_priv(dev);
1133
1134 strcpy(info->driver, DRV_NAME);
1135 strcpy(info->version, DRV_VERSION);
1136 strcpy(info->fw_version, "N/A");
1137
1138 switch (tun->flags & TUN_TYPE_MASK) {
1139 case TUN_TUN_DEV:
1140 strcpy(info->bus_info, "tun");
1141 break;
1142 case TUN_TAP_DEV:
1143 strcpy(info->bus_info, "tap");
1144 break;
1145 }
1146 }
1147
1148 static u32 tun_get_msglevel(struct net_device *dev)
1149 {
1150 #ifdef TUN_DEBUG
1151 struct tun_struct *tun = netdev_priv(dev);
1152 return tun->debug;
1153 #else
1154 return -EOPNOTSUPP;
1155 #endif
1156 }
1157
1158 static void tun_set_msglevel(struct net_device *dev, u32 value)
1159 {
1160 #ifdef TUN_DEBUG
1161 struct tun_struct *tun = netdev_priv(dev);
1162 tun->debug = value;
1163 #endif
1164 }
1165
1166 static u32 tun_get_link(struct net_device *dev)
1167 {
1168 struct tun_struct *tun = netdev_priv(dev);
1169 return tun->attached;
1170 }
1171
1172 static u32 tun_get_rx_csum(struct net_device *dev)
1173 {
1174 struct tun_struct *tun = netdev_priv(dev);
1175 return (tun->flags & TUN_NOCHECKSUM) == 0;
1176 }
1177
1178 static int tun_set_rx_csum(struct net_device *dev, u32 data)
1179 {
1180 struct tun_struct *tun = netdev_priv(dev);
1181 if (data)
1182 tun->flags &= ~TUN_NOCHECKSUM;
1183 else
1184 tun->flags |= TUN_NOCHECKSUM;
1185 return 0;
1186 }
1187
1188 static const struct ethtool_ops tun_ethtool_ops = {
1189 .get_settings = tun_get_settings,
1190 .get_drvinfo = tun_get_drvinfo,
1191 .get_msglevel = tun_get_msglevel,
1192 .set_msglevel = tun_set_msglevel,
1193 .get_link = tun_get_link,
1194 .get_rx_csum = tun_get_rx_csum,
1195 .set_rx_csum = tun_set_rx_csum
1196 };
1197
1198 static int tun_init_net(struct net *net)
1199 {
1200 struct tun_net *tn;
1201
1202 tn = kmalloc(sizeof(*tn), GFP_KERNEL);
1203 if (tn == NULL)
1204 return -ENOMEM;
1205
1206 INIT_LIST_HEAD(&tn->dev_list);
1207
1208 if (net_assign_generic(net, tun_net_id, tn)) {
1209 kfree(tn);
1210 return -ENOMEM;
1211 }
1212
1213 return 0;
1214 }
1215
1216 static void tun_exit_net(struct net *net)
1217 {
1218 struct tun_net *tn;
1219 struct tun_struct *tun, *nxt;
1220
1221 tn = net_generic(net, tun_net_id);
1222
1223 rtnl_lock();
1224 list_for_each_entry_safe(tun, nxt, &tn->dev_list, list) {
1225 DBG(KERN_INFO "%s cleaned up\n", tun->dev->name);
1226 unregister_netdevice(tun->dev);
1227 }
1228 rtnl_unlock();
1229
1230 kfree(tn);
1231 }
1232
1233 static struct pernet_operations tun_net_ops = {
1234 .init = tun_init_net,
1235 .exit = tun_exit_net,
1236 };
1237
1238 static int __init tun_init(void)
1239 {
1240 int ret = 0;
1241
1242 printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
1243 printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
1244
1245 ret = register_pernet_gen_device(&tun_net_id, &tun_net_ops);
1246 if (ret) {
1247 printk(KERN_ERR "tun: Can't register pernet ops\n");
1248 goto err_pernet;
1249 }
1250
1251 ret = misc_register(&tun_miscdev);
1252 if (ret) {
1253 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
1254 goto err_misc;
1255 }
1256 return 0;
1257
1258 err_misc:
1259 unregister_pernet_gen_device(tun_net_id, &tun_net_ops);
1260 err_pernet:
1261 return ret;
1262 }
1263
1264 static void tun_cleanup(void)
1265 {
1266 misc_deregister(&tun_miscdev);
1267 unregister_pernet_gen_device(tun_net_id, &tun_net_ops);
1268 }
1269
1270 module_init(tun_init);
1271 module_exit(tun_cleanup);
1272 MODULE_DESCRIPTION(DRV_DESCRIPTION);
1273 MODULE_AUTHOR(DRV_COPYRIGHT);
1274 MODULE_LICENSE("GPL");
1275 MODULE_ALIAS_MISCDEV(TUN_MINOR);
Support for the Chinese Samsung S3C2440 based development boards