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Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
[mirror_ubuntu-artful-kernel.git] / drivers / net / tun.c
1 /*
2 * TUN - Universal TUN/TAP device driver.
3 * Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $
16 */
17
18 /*
19 * Changes:
20 *
21 * Brian Braunstein <linuxkernel@bristyle.com> 2007/03/23
22 * Fixed hw address handling. Now net_device.dev_addr is kept consistent
23 * with tun.dev_addr when the address is set by this module.
24 *
25 * Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
26 * Add TUNSETLINK ioctl to set the link encapsulation
27 *
28 * Mark Smith <markzzzsmith@yahoo.com.au>
29 * Use random_ether_addr() for tap MAC address.
30 *
31 * Harald Roelle <harald.roelle@ifi.lmu.de> 2004/04/20
32 * Fixes in packet dropping, queue length setting and queue wakeup.
33 * Increased default tx queue length.
34 * Added ethtool API.
35 * Minor cleanups
36 *
37 * Daniel Podlejski <underley@underley.eu.org>
38 * Modifications for 2.3.99-pre5 kernel.
39 */
40
41 #define DRV_NAME "tun"
42 #define DRV_VERSION "1.6"
43 #define DRV_DESCRIPTION "Universal TUN/TAP device driver"
44 #define DRV_COPYRIGHT "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>"
45
46 #include <linux/module.h>
47 #include <linux/errno.h>
48 #include <linux/kernel.h>
49 #include <linux/major.h>
50 #include <linux/slab.h>
51 #include <linux/poll.h>
52 #include <linux/fcntl.h>
53 #include <linux/init.h>
54 #include <linux/skbuff.h>
55 #include <linux/netdevice.h>
56 #include <linux/etherdevice.h>
57 #include <linux/miscdevice.h>
58 #include <linux/ethtool.h>
59 #include <linux/rtnetlink.h>
60 #include <linux/if.h>
61 #include <linux/if_arp.h>
62 #include <linux/if_ether.h>
63 #include <linux/if_tun.h>
64 #include <linux/crc32.h>
65 #include <linux/nsproxy.h>
66 #include <linux/virtio_net.h>
67 #include <net/net_namespace.h>
68 #include <net/netns/generic.h>
69
70 #include <asm/system.h>
71 #include <asm/uaccess.h>
72
73 /* Uncomment to enable debugging */
74 /* #define TUN_DEBUG 1 */
75
76 #ifdef TUN_DEBUG
77 static int debug;
78
79 #define DBG if(tun->debug)printk
80 #define DBG1 if(debug==2)printk
81 #else
82 #define DBG( a... )
83 #define DBG1( a... )
84 #endif
85
86 struct tun_struct {
87 struct list_head list;
88 unsigned long flags;
89 int attached;
90 uid_t owner;
91 gid_t group;
92
93 wait_queue_head_t read_wait;
94 struct sk_buff_head readq;
95
96 struct net_device *dev;
97
98 struct fasync_struct *fasync;
99
100 unsigned long if_flags;
101 u8 dev_addr[ETH_ALEN];
102 u32 chr_filter[2];
103 u32 net_filter[2];
104
105 #ifdef TUN_DEBUG
106 int debug;
107 #endif
108 };
109
110 /* Network device part of the driver */
111
112 static unsigned int tun_net_id;
113 struct tun_net {
114 struct list_head dev_list;
115 };
116
117 static const struct ethtool_ops tun_ethtool_ops;
118
119 /* Net device open. */
120 static int tun_net_open(struct net_device *dev)
121 {
122 netif_start_queue(dev);
123 return 0;
124 }
125
126 /* Net device close. */
127 static int tun_net_close(struct net_device *dev)
128 {
129 netif_stop_queue(dev);
130 return 0;
131 }
132
133 /* Net device start xmit */
134 static int tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
135 {
136 struct tun_struct *tun = netdev_priv(dev);
137
138 DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len);
139
140 /* Drop packet if interface is not attached */
141 if (!tun->attached)
142 goto drop;
143
144 /* Packet dropping */
145 if (skb_queue_len(&tun->readq) >= dev->tx_queue_len) {
146 if (!(tun->flags & TUN_ONE_QUEUE)) {
147 /* Normal queueing mode. */
148 /* Packet scheduler handles dropping of further packets. */
149 netif_stop_queue(dev);
150
151 /* We won't see all dropped packets individually, so overrun
152 * error is more appropriate. */
153 dev->stats.tx_fifo_errors++;
154 } else {
155 /* Single queue mode.
156 * Driver handles dropping of all packets itself. */
157 goto drop;
158 }
159 }
160
161 /* Queue packet */
162 skb_queue_tail(&tun->readq, skb);
163 dev->trans_start = jiffies;
164
165 /* Notify and wake up reader process */
166 if (tun->flags & TUN_FASYNC)
167 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
168 wake_up_interruptible(&tun->read_wait);
169 return 0;
170
171 drop:
172 dev->stats.tx_dropped++;
173 kfree_skb(skb);
174 return 0;
175 }
176
177 /** Add the specified Ethernet address to this multicast filter. */
178 static void
179 add_multi(u32* filter, const u8* addr)
180 {
181 int bit_nr = ether_crc(ETH_ALEN, addr) >> 26;
182 filter[bit_nr >> 5] |= 1 << (bit_nr & 31);
183 }
184
185 /** Remove the specified Ethernet addres from this multicast filter. */
186 static void
187 del_multi(u32* filter, const u8* addr)
188 {
189 int bit_nr = ether_crc(ETH_ALEN, addr) >> 26;
190 filter[bit_nr >> 5] &= ~(1 << (bit_nr & 31));
191 }
192
193 /** Update the list of multicast groups to which the network device belongs.
194 * This list is used to filter packets being sent from the character device to
195 * the network device. */
196 static void
197 tun_net_mclist(struct net_device *dev)
198 {
199 struct tun_struct *tun = netdev_priv(dev);
200 const struct dev_mc_list *mclist;
201 int i;
202 DECLARE_MAC_BUF(mac);
203 DBG(KERN_DEBUG "%s: tun_net_mclist: mc_count %d\n",
204 dev->name, dev->mc_count);
205 memset(tun->chr_filter, 0, sizeof tun->chr_filter);
206 for (i = 0, mclist = dev->mc_list; i < dev->mc_count && mclist != NULL;
207 i++, mclist = mclist->next) {
208 add_multi(tun->net_filter, mclist->dmi_addr);
209 DBG(KERN_DEBUG "%s: tun_net_mclist: %s\n",
210 dev->name, print_mac(mac, mclist->dmi_addr));
211 }
212 }
213
214 #define MIN_MTU 68
215 #define MAX_MTU 65535
216
217 static int
218 tun_net_change_mtu(struct net_device *dev, int new_mtu)
219 {
220 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
221 return -EINVAL;
222 dev->mtu = new_mtu;
223 return 0;
224 }
225
226 /* Initialize net device. */
227 static void tun_net_init(struct net_device *dev)
228 {
229 struct tun_struct *tun = netdev_priv(dev);
230
231 switch (tun->flags & TUN_TYPE_MASK) {
232 case TUN_TUN_DEV:
233 /* Point-to-Point TUN Device */
234 dev->hard_header_len = 0;
235 dev->addr_len = 0;
236 dev->mtu = 1500;
237 dev->change_mtu = tun_net_change_mtu;
238
239 /* Zero header length */
240 dev->type = ARPHRD_NONE;
241 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
242 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
243 break;
244
245 case TUN_TAP_DEV:
246 /* Ethernet TAP Device */
247 dev->set_multicast_list = tun_net_mclist;
248
249 ether_setup(dev);
250 dev->change_mtu = tun_net_change_mtu;
251
252 /* random address already created for us by tun_set_iff, use it */
253 memcpy(dev->dev_addr, tun->dev_addr, min(sizeof(tun->dev_addr), sizeof(dev->dev_addr)) );
254
255 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
256 break;
257 }
258 }
259
260 /* Character device part */
261
262 /* Poll */
263 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
264 {
265 struct tun_struct *tun = file->private_data;
266 unsigned int mask = POLLOUT | POLLWRNORM;
267
268 if (!tun)
269 return -EBADFD;
270
271 DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
272
273 poll_wait(file, &tun->read_wait, wait);
274
275 if (!skb_queue_empty(&tun->readq))
276 mask |= POLLIN | POLLRDNORM;
277
278 return mask;
279 }
280
281 /* Get packet from user space buffer */
282 static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, size_t count)
283 {
284 struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) };
285 struct sk_buff *skb;
286 size_t len = count, align = 0;
287 struct virtio_net_hdr gso = { 0 };
288
289 if (!(tun->flags & TUN_NO_PI)) {
290 if ((len -= sizeof(pi)) > count)
291 return -EINVAL;
292
293 if(memcpy_fromiovec((void *)&pi, iv, sizeof(pi)))
294 return -EFAULT;
295 }
296
297 if (tun->flags & TUN_VNET_HDR) {
298 if ((len -= sizeof(gso)) > count)
299 return -EINVAL;
300
301 if (memcpy_fromiovec((void *)&gso, iv, sizeof(gso)))
302 return -EFAULT;
303
304 if (gso.hdr_len > len)
305 return -EINVAL;
306 }
307
308 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
309 align = NET_IP_ALIGN;
310 if (unlikely(len < ETH_HLEN))
311 return -EINVAL;
312 }
313
314 if (!(skb = alloc_skb(len + align, GFP_KERNEL))) {
315 tun->dev->stats.rx_dropped++;
316 return -ENOMEM;
317 }
318
319 if (align)
320 skb_reserve(skb, align);
321 if (memcpy_fromiovec(skb_put(skb, len), iv, len)) {
322 tun->dev->stats.rx_dropped++;
323 kfree_skb(skb);
324 return -EFAULT;
325 }
326
327 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
328 if (!skb_partial_csum_set(skb, gso.csum_start,
329 gso.csum_offset)) {
330 tun->dev->stats.rx_frame_errors++;
331 kfree_skb(skb);
332 return -EINVAL;
333 }
334 } else if (tun->flags & TUN_NOCHECKSUM)
335 skb->ip_summed = CHECKSUM_UNNECESSARY;
336
337 switch (tun->flags & TUN_TYPE_MASK) {
338 case TUN_TUN_DEV:
339 if (tun->flags & TUN_NO_PI) {
340 switch (skb->data[0] & 0xf0) {
341 case 0x40:
342 pi.proto = htons(ETH_P_IP);
343 break;
344 case 0x60:
345 pi.proto = htons(ETH_P_IPV6);
346 break;
347 default:
348 tun->dev->stats.rx_dropped++;
349 kfree_skb(skb);
350 return -EINVAL;
351 }
352 }
353
354 skb_reset_mac_header(skb);
355 skb->protocol = pi.proto;
356 skb->dev = tun->dev;
357 break;
358 case TUN_TAP_DEV:
359 skb->protocol = eth_type_trans(skb, tun->dev);
360 break;
361 };
362
363 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
364 pr_debug("GSO!\n");
365 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
366 case VIRTIO_NET_HDR_GSO_TCPV4:
367 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
368 break;
369 case VIRTIO_NET_HDR_GSO_TCPV6:
370 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
371 break;
372 default:
373 tun->dev->stats.rx_frame_errors++;
374 kfree_skb(skb);
375 return -EINVAL;
376 }
377
378 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
379 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
380
381 skb_shinfo(skb)->gso_size = gso.gso_size;
382 if (skb_shinfo(skb)->gso_size == 0) {
383 tun->dev->stats.rx_frame_errors++;
384 kfree_skb(skb);
385 return -EINVAL;
386 }
387
388 /* Header must be checked, and gso_segs computed. */
389 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
390 skb_shinfo(skb)->gso_segs = 0;
391 }
392
393 netif_rx_ni(skb);
394 tun->dev->last_rx = jiffies;
395
396 tun->dev->stats.rx_packets++;
397 tun->dev->stats.rx_bytes += len;
398
399 return count;
400 }
401
402 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
403 unsigned long count, loff_t pos)
404 {
405 struct tun_struct *tun = iocb->ki_filp->private_data;
406
407 if (!tun)
408 return -EBADFD;
409
410 DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
411
412 return tun_get_user(tun, (struct iovec *) iv, iov_length(iv, count));
413 }
414
415 /* Put packet to the user space buffer */
416 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
417 struct sk_buff *skb,
418 struct iovec *iv, int len)
419 {
420 struct tun_pi pi = { 0, skb->protocol };
421 ssize_t total = 0;
422
423 if (!(tun->flags & TUN_NO_PI)) {
424 if ((len -= sizeof(pi)) < 0)
425 return -EINVAL;
426
427 if (len < skb->len) {
428 /* Packet will be striped */
429 pi.flags |= TUN_PKT_STRIP;
430 }
431
432 if (memcpy_toiovec(iv, (void *) &pi, sizeof(pi)))
433 return -EFAULT;
434 total += sizeof(pi);
435 }
436
437 if (tun->flags & TUN_VNET_HDR) {
438 struct virtio_net_hdr gso = { 0 }; /* no info leak */
439 if ((len -= sizeof(gso)) < 0)
440 return -EINVAL;
441
442 if (skb_is_gso(skb)) {
443 struct skb_shared_info *sinfo = skb_shinfo(skb);
444
445 /* This is a hint as to how much should be linear. */
446 gso.hdr_len = skb_headlen(skb);
447 gso.gso_size = sinfo->gso_size;
448 if (sinfo->gso_type & SKB_GSO_TCPV4)
449 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
450 else if (sinfo->gso_type & SKB_GSO_TCPV6)
451 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
452 else
453 BUG();
454 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
455 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
456 } else
457 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
458
459 if (skb->ip_summed == CHECKSUM_PARTIAL) {
460 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
461 gso.csum_start = skb->csum_start - skb_headroom(skb);
462 gso.csum_offset = skb->csum_offset;
463 } /* else everything is zero */
464
465 if (unlikely(memcpy_toiovec(iv, (void *)&gso, sizeof(gso))))
466 return -EFAULT;
467 total += sizeof(gso);
468 }
469
470 len = min_t(int, skb->len, len);
471
472 skb_copy_datagram_iovec(skb, 0, iv, len);
473 total += len;
474
475 tun->dev->stats.tx_packets++;
476 tun->dev->stats.tx_bytes += len;
477
478 return total;
479 }
480
481 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
482 unsigned long count, loff_t pos)
483 {
484 struct file *file = iocb->ki_filp;
485 struct tun_struct *tun = file->private_data;
486 DECLARE_WAITQUEUE(wait, current);
487 struct sk_buff *skb;
488 ssize_t len, ret = 0;
489 DECLARE_MAC_BUF(mac);
490
491 if (!tun)
492 return -EBADFD;
493
494 DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
495
496 len = iov_length(iv, count);
497 if (len < 0)
498 return -EINVAL;
499
500 add_wait_queue(&tun->read_wait, &wait);
501 while (len) {
502 const u8 ones[ ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
503 u8 addr[ ETH_ALEN];
504 int bit_nr;
505
506 current->state = TASK_INTERRUPTIBLE;
507
508 /* Read frames from the queue */
509 if (!(skb=skb_dequeue(&tun->readq))) {
510 if (file->f_flags & O_NONBLOCK) {
511 ret = -EAGAIN;
512 break;
513 }
514 if (signal_pending(current)) {
515 ret = -ERESTARTSYS;
516 break;
517 }
518
519 /* Nothing to read, let's sleep */
520 schedule();
521 continue;
522 }
523 netif_wake_queue(tun->dev);
524
525 /** Decide whether to accept this packet. This code is designed to
526 * behave identically to an Ethernet interface. Accept the packet if
527 * - we are promiscuous.
528 * - the packet is addressed to us.
529 * - the packet is broadcast.
530 * - the packet is multicast and
531 * - we are multicast promiscous.
532 * - we belong to the multicast group.
533 */
534 skb_copy_from_linear_data(skb, addr, min_t(size_t, sizeof addr,
535 skb->len));
536 bit_nr = ether_crc(sizeof addr, addr) >> 26;
537 if ((tun->if_flags & IFF_PROMISC) ||
538 memcmp(addr, tun->dev_addr, sizeof addr) == 0 ||
539 memcmp(addr, ones, sizeof addr) == 0 ||
540 (((addr[0] == 1 && addr[1] == 0 && addr[2] == 0x5e) ||
541 (addr[0] == 0x33 && addr[1] == 0x33)) &&
542 ((tun->if_flags & IFF_ALLMULTI) ||
543 (tun->chr_filter[bit_nr >> 5] & (1 << (bit_nr & 31)))))) {
544 DBG(KERN_DEBUG "%s: tun_chr_readv: accepted: %s\n",
545 tun->dev->name, print_mac(mac, addr));
546 ret = tun_put_user(tun, skb, (struct iovec *) iv, len);
547 kfree_skb(skb);
548 break;
549 } else {
550 DBG(KERN_DEBUG "%s: tun_chr_readv: rejected: %s\n",
551 tun->dev->name, print_mac(mac, addr));
552 kfree_skb(skb);
553 continue;
554 }
555 }
556
557 current->state = TASK_RUNNING;
558 remove_wait_queue(&tun->read_wait, &wait);
559
560 return ret;
561 }
562
563 static void tun_setup(struct net_device *dev)
564 {
565 struct tun_struct *tun = netdev_priv(dev);
566
567 skb_queue_head_init(&tun->readq);
568 init_waitqueue_head(&tun->read_wait);
569
570 tun->owner = -1;
571 tun->group = -1;
572
573 dev->open = tun_net_open;
574 dev->hard_start_xmit = tun_net_xmit;
575 dev->stop = tun_net_close;
576 dev->ethtool_ops = &tun_ethtool_ops;
577 dev->destructor = free_netdev;
578 dev->features |= NETIF_F_NETNS_LOCAL;
579 }
580
581 static struct tun_struct *tun_get_by_name(struct tun_net *tn, const char *name)
582 {
583 struct tun_struct *tun;
584
585 ASSERT_RTNL();
586 list_for_each_entry(tun, &tn->dev_list, list) {
587 if (!strncmp(tun->dev->name, name, IFNAMSIZ))
588 return tun;
589 }
590
591 return NULL;
592 }
593
594 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
595 {
596 struct tun_net *tn;
597 struct tun_struct *tun;
598 struct net_device *dev;
599 int err;
600
601 tn = net_generic(net, tun_net_id);
602 tun = tun_get_by_name(tn, ifr->ifr_name);
603 if (tun) {
604 if (tun->attached)
605 return -EBUSY;
606
607 /* Check permissions */
608 if (((tun->owner != -1 &&
609 current->euid != tun->owner) ||
610 (tun->group != -1 &&
611 current->egid != tun->group)) &&
612 !capable(CAP_NET_ADMIN))
613 return -EPERM;
614 }
615 else if (__dev_get_by_name(net, ifr->ifr_name))
616 return -EINVAL;
617 else {
618 char *name;
619 unsigned long flags = 0;
620
621 err = -EINVAL;
622
623 if (!capable(CAP_NET_ADMIN))
624 return -EPERM;
625
626 /* Set dev type */
627 if (ifr->ifr_flags & IFF_TUN) {
628 /* TUN device */
629 flags |= TUN_TUN_DEV;
630 name = "tun%d";
631 } else if (ifr->ifr_flags & IFF_TAP) {
632 /* TAP device */
633 flags |= TUN_TAP_DEV;
634 name = "tap%d";
635 } else
636 goto failed;
637
638 if (*ifr->ifr_name)
639 name = ifr->ifr_name;
640
641 dev = alloc_netdev(sizeof(struct tun_struct), name,
642 tun_setup);
643 if (!dev)
644 return -ENOMEM;
645
646 dev_net_set(dev, net);
647 tun = netdev_priv(dev);
648 tun->dev = dev;
649 tun->flags = flags;
650 /* Be promiscuous by default to maintain previous behaviour. */
651 tun->if_flags = IFF_PROMISC;
652 /* Generate random Ethernet address. */
653 *(__be16 *)tun->dev_addr = htons(0x00FF);
654 get_random_bytes(tun->dev_addr + sizeof(u16), 4);
655 memset(tun->chr_filter, 0, sizeof tun->chr_filter);
656
657 tun_net_init(dev);
658
659 if (strchr(dev->name, '%')) {
660 err = dev_alloc_name(dev, dev->name);
661 if (err < 0)
662 goto err_free_dev;
663 }
664
665 err = register_netdevice(tun->dev);
666 if (err < 0)
667 goto err_free_dev;
668
669 list_add(&tun->list, &tn->dev_list);
670 }
671
672 DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
673
674 if (ifr->ifr_flags & IFF_NO_PI)
675 tun->flags |= TUN_NO_PI;
676 else
677 tun->flags &= ~TUN_NO_PI;
678
679 if (ifr->ifr_flags & IFF_ONE_QUEUE)
680 tun->flags |= TUN_ONE_QUEUE;
681 else
682 tun->flags &= ~TUN_ONE_QUEUE;
683
684 if (ifr->ifr_flags & IFF_VNET_HDR)
685 tun->flags |= TUN_VNET_HDR;
686 else
687 tun->flags &= ~TUN_VNET_HDR;
688
689 file->private_data = tun;
690 tun->attached = 1;
691 get_net(dev_net(tun->dev));
692
693 /* Make sure persistent devices do not get stuck in
694 * xoff state.
695 */
696 if (netif_running(tun->dev))
697 netif_wake_queue(tun->dev);
698
699 strcpy(ifr->ifr_name, tun->dev->name);
700 return 0;
701
702 err_free_dev:
703 free_netdev(dev);
704 failed:
705 return err;
706 }
707
708 /* This is like a cut-down ethtool ops, except done via tun fd so no
709 * privs required. */
710 static int set_offload(struct net_device *dev, unsigned long arg)
711 {
712 unsigned int old_features, features;
713
714 old_features = dev->features;
715 /* Unset features, set them as we chew on the arg. */
716 features = (old_features & ~(NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST
717 |NETIF_F_TSO_ECN|NETIF_F_TSO|NETIF_F_TSO6));
718
719 if (arg & TUN_F_CSUM) {
720 features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
721 arg &= ~TUN_F_CSUM;
722
723 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
724 if (arg & TUN_F_TSO_ECN) {
725 features |= NETIF_F_TSO_ECN;
726 arg &= ~TUN_F_TSO_ECN;
727 }
728 if (arg & TUN_F_TSO4)
729 features |= NETIF_F_TSO;
730 if (arg & TUN_F_TSO6)
731 features |= NETIF_F_TSO6;
732 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
733 }
734 }
735
736 /* This gives the user a way to test for new features in future by
737 * trying to set them. */
738 if (arg)
739 return -EINVAL;
740
741 dev->features = features;
742 if (old_features != dev->features)
743 netdev_features_change(dev);
744
745 return 0;
746 }
747
748 static int tun_chr_ioctl(struct inode *inode, struct file *file,
749 unsigned int cmd, unsigned long arg)
750 {
751 struct tun_struct *tun = file->private_data;
752 void __user* argp = (void __user*)arg;
753 struct ifreq ifr;
754 DECLARE_MAC_BUF(mac);
755
756 if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
757 if (copy_from_user(&ifr, argp, sizeof ifr))
758 return -EFAULT;
759
760 if (cmd == TUNSETIFF && !tun) {
761 int err;
762
763 ifr.ifr_name[IFNAMSIZ-1] = '\0';
764
765 rtnl_lock();
766 err = tun_set_iff(current->nsproxy->net_ns, file, &ifr);
767 rtnl_unlock();
768
769 if (err)
770 return err;
771
772 if (copy_to_user(argp, &ifr, sizeof(ifr)))
773 return -EFAULT;
774 return 0;
775 }
776
777 if (cmd == TUNGETFEATURES) {
778 /* Currently this just means: "what IFF flags are valid?".
779 * This is needed because we never checked for invalid flags on
780 * TUNSETIFF. */
781 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
782 IFF_VNET_HDR,
783 (unsigned int __user*)argp);
784 }
785
786 if (!tun)
787 return -EBADFD;
788
789 DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
790
791 switch (cmd) {
792 case TUNSETNOCSUM:
793 /* Disable/Enable checksum */
794 if (arg)
795 tun->flags |= TUN_NOCHECKSUM;
796 else
797 tun->flags &= ~TUN_NOCHECKSUM;
798
799 DBG(KERN_INFO "%s: checksum %s\n",
800 tun->dev->name, arg ? "disabled" : "enabled");
801 break;
802
803 case TUNSETPERSIST:
804 /* Disable/Enable persist mode */
805 if (arg)
806 tun->flags |= TUN_PERSIST;
807 else
808 tun->flags &= ~TUN_PERSIST;
809
810 DBG(KERN_INFO "%s: persist %s\n",
811 tun->dev->name, arg ? "enabled" : "disabled");
812 break;
813
814 case TUNSETOWNER:
815 /* Set owner of the device */
816 tun->owner = (uid_t) arg;
817
818 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
819 break;
820
821 case TUNSETGROUP:
822 /* Set group of the device */
823 tun->group= (gid_t) arg;
824
825 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group);
826 break;
827
828 case TUNSETLINK:
829 {
830 int ret;
831
832 /* Only allow setting the type when the interface is down */
833 rtnl_lock();
834 if (tun->dev->flags & IFF_UP) {
835 DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
836 tun->dev->name);
837 ret = -EBUSY;
838 } else {
839 tun->dev->type = (int) arg;
840 DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
841 ret = 0;
842 }
843 rtnl_unlock();
844 return ret;
845 }
846
847 #ifdef TUN_DEBUG
848 case TUNSETDEBUG:
849 tun->debug = arg;
850 break;
851 #endif
852
853 case TUNSETOFFLOAD:
854 {
855 int ret;
856 rtnl_lock();
857 ret = set_offload(tun->dev, arg);
858 rtnl_unlock();
859 return ret;
860 }
861
862 case SIOCGIFFLAGS:
863 ifr.ifr_flags = tun->if_flags;
864 if (copy_to_user( argp, &ifr, sizeof ifr))
865 return -EFAULT;
866 return 0;
867
868 case SIOCSIFFLAGS:
869 /** Set the character device's interface flags. Currently only
870 * IFF_PROMISC and IFF_ALLMULTI are used. */
871 tun->if_flags = ifr.ifr_flags;
872 DBG(KERN_INFO "%s: interface flags 0x%lx\n",
873 tun->dev->name, tun->if_flags);
874 return 0;
875
876 case SIOCGIFHWADDR:
877 /* Note: the actual net device's address may be different */
878 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev_addr,
879 min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
880 if (copy_to_user( argp, &ifr, sizeof ifr))
881 return -EFAULT;
882 return 0;
883
884 case SIOCSIFHWADDR:
885 {
886 /* try to set the actual net device's hw address */
887 int ret;
888
889 rtnl_lock();
890 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
891 rtnl_unlock();
892
893 if (ret == 0) {
894 /** Set the character device's hardware address. This is used when
895 * filtering packets being sent from the network device to the character
896 * device. */
897 memcpy(tun->dev_addr, ifr.ifr_hwaddr.sa_data,
898 min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
899 DBG(KERN_DEBUG "%s: set hardware address: %x:%x:%x:%x:%x:%x\n",
900 tun->dev->name,
901 tun->dev_addr[0], tun->dev_addr[1], tun->dev_addr[2],
902 tun->dev_addr[3], tun->dev_addr[4], tun->dev_addr[5]);
903 }
904
905 return ret;
906 }
907
908 case SIOCADDMULTI:
909 /** Add the specified group to the character device's multicast filter
910 * list. */
911 rtnl_lock();
912 netif_tx_lock_bh(tun->dev);
913 add_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
914 netif_tx_unlock_bh(tun->dev);
915 rtnl_unlock();
916
917 DBG(KERN_DEBUG "%s: add multi: %s\n",
918 tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data));
919 return 0;
920
921 case SIOCDELMULTI:
922 /** Remove the specified group from the character device's multicast
923 * filter list. */
924 rtnl_lock();
925 netif_tx_lock_bh(tun->dev);
926 del_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
927 netif_tx_unlock_bh(tun->dev);
928 rtnl_unlock();
929
930 DBG(KERN_DEBUG "%s: del multi: %s\n",
931 tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data));
932 return 0;
933
934 default:
935 return -EINVAL;
936 };
937
938 return 0;
939 }
940
941 static int tun_chr_fasync(int fd, struct file *file, int on)
942 {
943 struct tun_struct *tun = file->private_data;
944 int ret;
945
946 if (!tun)
947 return -EBADFD;
948
949 DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
950
951 if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
952 return ret;
953
954 if (on) {
955 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
956 if (ret)
957 return ret;
958 tun->flags |= TUN_FASYNC;
959 } else
960 tun->flags &= ~TUN_FASYNC;
961
962 return 0;
963 }
964
965 static int tun_chr_open(struct inode *inode, struct file * file)
966 {
967 DBG1(KERN_INFO "tunX: tun_chr_open\n");
968 file->private_data = NULL;
969 return 0;
970 }
971
972 static int tun_chr_close(struct inode *inode, struct file *file)
973 {
974 struct tun_struct *tun = file->private_data;
975
976 if (!tun)
977 return 0;
978
979 DBG(KERN_INFO "%s: tun_chr_close\n", tun->dev->name);
980
981 tun_chr_fasync(-1, file, 0);
982
983 rtnl_lock();
984
985 /* Detach from net device */
986 file->private_data = NULL;
987 tun->attached = 0;
988 put_net(dev_net(tun->dev));
989
990 /* Drop read queue */
991 skb_queue_purge(&tun->readq);
992
993 if (!(tun->flags & TUN_PERSIST)) {
994 list_del(&tun->list);
995 unregister_netdevice(tun->dev);
996 }
997
998 rtnl_unlock();
999
1000 return 0;
1001 }
1002
1003 static const struct file_operations tun_fops = {
1004 .owner = THIS_MODULE,
1005 .llseek = no_llseek,
1006 .read = do_sync_read,
1007 .aio_read = tun_chr_aio_read,
1008 .write = do_sync_write,
1009 .aio_write = tun_chr_aio_write,
1010 .poll = tun_chr_poll,
1011 .ioctl = tun_chr_ioctl,
1012 .open = tun_chr_open,
1013 .release = tun_chr_close,
1014 .fasync = tun_chr_fasync
1015 };
1016
1017 static struct miscdevice tun_miscdev = {
1018 .minor = TUN_MINOR,
1019 .name = "tun",
1020 .fops = &tun_fops,
1021 };
1022
1023 /* ethtool interface */
1024
1025 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1026 {
1027 cmd->supported = 0;
1028 cmd->advertising = 0;
1029 cmd->speed = SPEED_10;
1030 cmd->duplex = DUPLEX_FULL;
1031 cmd->port = PORT_TP;
1032 cmd->phy_address = 0;
1033 cmd->transceiver = XCVR_INTERNAL;
1034 cmd->autoneg = AUTONEG_DISABLE;
1035 cmd->maxtxpkt = 0;
1036 cmd->maxrxpkt = 0;
1037 return 0;
1038 }
1039
1040 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
1041 {
1042 struct tun_struct *tun = netdev_priv(dev);
1043
1044 strcpy(info->driver, DRV_NAME);
1045 strcpy(info->version, DRV_VERSION);
1046 strcpy(info->fw_version, "N/A");
1047
1048 switch (tun->flags & TUN_TYPE_MASK) {
1049 case TUN_TUN_DEV:
1050 strcpy(info->bus_info, "tun");
1051 break;
1052 case TUN_TAP_DEV:
1053 strcpy(info->bus_info, "tap");
1054 break;
1055 }
1056 }
1057
1058 static u32 tun_get_msglevel(struct net_device *dev)
1059 {
1060 #ifdef TUN_DEBUG
1061 struct tun_struct *tun = netdev_priv(dev);
1062 return tun->debug;
1063 #else
1064 return -EOPNOTSUPP;
1065 #endif
1066 }
1067
1068 static void tun_set_msglevel(struct net_device *dev, u32 value)
1069 {
1070 #ifdef TUN_DEBUG
1071 struct tun_struct *tun = netdev_priv(dev);
1072 tun->debug = value;
1073 #endif
1074 }
1075
1076 static u32 tun_get_link(struct net_device *dev)
1077 {
1078 struct tun_struct *tun = netdev_priv(dev);
1079 return tun->attached;
1080 }
1081
1082 static u32 tun_get_rx_csum(struct net_device *dev)
1083 {
1084 struct tun_struct *tun = netdev_priv(dev);
1085 return (tun->flags & TUN_NOCHECKSUM) == 0;
1086 }
1087
1088 static int tun_set_rx_csum(struct net_device *dev, u32 data)
1089 {
1090 struct tun_struct *tun = netdev_priv(dev);
1091 if (data)
1092 tun->flags &= ~TUN_NOCHECKSUM;
1093 else
1094 tun->flags |= TUN_NOCHECKSUM;
1095 return 0;
1096 }
1097
1098 static const struct ethtool_ops tun_ethtool_ops = {
1099 .get_settings = tun_get_settings,
1100 .get_drvinfo = tun_get_drvinfo,
1101 .get_msglevel = tun_get_msglevel,
1102 .set_msglevel = tun_set_msglevel,
1103 .get_link = tun_get_link,
1104 .get_rx_csum = tun_get_rx_csum,
1105 .set_rx_csum = tun_set_rx_csum
1106 };
1107
1108 static int tun_init_net(struct net *net)
1109 {
1110 struct tun_net *tn;
1111
1112 tn = kmalloc(sizeof(*tn), GFP_KERNEL);
1113 if (tn == NULL)
1114 return -ENOMEM;
1115
1116 INIT_LIST_HEAD(&tn->dev_list);
1117
1118 if (net_assign_generic(net, tun_net_id, tn)) {
1119 kfree(tn);
1120 return -ENOMEM;
1121 }
1122
1123 return 0;
1124 }
1125
1126 static void tun_exit_net(struct net *net)
1127 {
1128 struct tun_net *tn;
1129 struct tun_struct *tun, *nxt;
1130
1131 tn = net_generic(net, tun_net_id);
1132
1133 rtnl_lock();
1134 list_for_each_entry_safe(tun, nxt, &tn->dev_list, list) {
1135 DBG(KERN_INFO "%s cleaned up\n", tun->dev->name);
1136 unregister_netdevice(tun->dev);
1137 }
1138 rtnl_unlock();
1139
1140 kfree(tn);
1141 }
1142
1143 static struct pernet_operations tun_net_ops = {
1144 .init = tun_init_net,
1145 .exit = tun_exit_net,
1146 };
1147
1148 static int __init tun_init(void)
1149 {
1150 int ret = 0;
1151
1152 printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
1153 printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
1154
1155 ret = register_pernet_gen_device(&tun_net_id, &tun_net_ops);
1156 if (ret) {
1157 printk(KERN_ERR "tun: Can't register pernet ops\n");
1158 goto err_pernet;
1159 }
1160
1161 ret = misc_register(&tun_miscdev);
1162 if (ret) {
1163 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
1164 goto err_misc;
1165 }
1166 return 0;
1167
1168 err_misc:
1169 unregister_pernet_gen_device(tun_net_id, &tun_net_ops);
1170 err_pernet:
1171 return ret;
1172 }
1173
1174 static void tun_cleanup(void)
1175 {
1176 misc_deregister(&tun_miscdev);
1177 unregister_pernet_gen_device(tun_net_id, &tun_net_ops);
1178 }
1179
1180 module_init(tun_init);
1181 module_exit(tun_cleanup);
1182 MODULE_DESCRIPTION(DRV_DESCRIPTION);
1183 MODULE_AUTHOR(DRV_COPYRIGHT);
1184 MODULE_LICENSE("GPL");
1185 MODULE_ALIAS_MISCDEV(TUN_MINOR);
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