projects / linux-2.6-block.git / blame
? search:
summary | shortlog | log | commit | commitdiff | tree
blob | blame (incremental) | history | HEAD
Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
[linux-2.6-block.git] / drivers / net / tun.c
CommitLineData
1da177e4
LT		 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 *
36226a8d
BB		 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 *
ff4cc3ac
MK		 25 * Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
26 * Add TUNSETLINK ioctl to set the link encapsulation
27 *
1da177e4
LT		 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
1da177e4
LT		 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>
d647a591 65#include <linux/nsproxy.h>
f43798c2 66#include <linux/virtio_net.h>
881d966b 67#include <net/net_namespace.h>
79d17604 68#include <net/netns/generic.h>
1da177e4
LT		 69
70#include <asm/system.h>
71#include <asm/uaccess.h>
72
14daa021
RR		 73/* Uncomment to enable debugging */
74/* #define TUN_DEBUG 1 */
75
1da177e4
LT		 76#ifdef TUN_DEBUG
77static int debug;
14daa021
RR		 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
86struct 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;
1da177e4 107#endif
14daa021 108};
1da177e4
LT		 109
110/* Network device part of the driver */
111
79d17604
PE		 112static unsigned int tun_net_id;
113struct tun_net {
114 struct list_head dev_list;
115};
116
7282d491 117static const struct ethtool_ops tun_ethtool_ops;
1da177e4
LT		 118
119/* Net device open. */
120static int tun_net_open(struct net_device *dev)
121{
122 netif_start_queue(dev);
123 return 0;
124}
125
126/* Net device close. */
127static int tun_net_close(struct net_device *dev)
128{
129 netif_stop_queue(dev);
130 return 0;
131}
132
133/* Net device start xmit */
134static 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. */
09f75cd7 153 dev->stats.tx_fifo_errors++;
1da177e4
LT		 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
171drop:
09f75cd7 172 dev->stats.tx_dropped++;
1da177e4
LT		 173 kfree_skb(skb);
174 return 0;
175}
176
177/** Add the specified Ethernet address to this multicast filter. */
178static void
179add_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. */
186static void
187del_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. */
196static void
197tun_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;
0795af57 202 DECLARE_MAC_BUF(mac);
1da177e4
LT		 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);
0795af57
JP		 209 DBG(KERN_DEBUG "%s: tun_net_mclist: %s\n",
210 dev->name, print_mac(mac, mclist->dmi_addr));
1da177e4
LT		 211 }
212}
213
4885a504
ES		 214#define MIN_MTU 68
215#define MAX_MTU 65535
216
217static int
218tun_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
1da177e4
LT		 226/* Initialize net device. */
227static void tun_net_init(struct net_device *dev)
228{
229 struct tun_struct *tun = netdev_priv(dev);
6aa20a22 230
1da177e4
LT		 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;
4885a504 237 dev->change_mtu = tun_net_change_mtu;
1da177e4
LT		 238
239 /* Zero header length */
6aa20a22 240 dev->type = ARPHRD_NONE;
1da177e4
LT		 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);
4885a504 250 dev->change_mtu = tun_net_change_mtu;
36226a8d
BB		 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
1da177e4
LT		 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 */
263static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
6aa20a22 264{
1da177e4
LT		 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);
6aa20a22 274
b03efcfb 275 if (!skb_queue_empty(&tun->readq))
1da177e4
LT		 276 mask |= POLLIN | POLLRDNORM;
277
278 return mask;
279}
280
281/* Get packet from user space buffer */
282static __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;
f43798c2 287 struct virtio_net_hdr gso = { 0 };
1da177e4
LT		 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
f43798c2
RR		 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
e01bf1c8 308 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
1da177e4 309 align = NET_IP_ALIGN;
e01bf1c8
RR		 310 if (unlikely(len < ETH_HLEN))
311 return -EINVAL;
312 }
6aa20a22 313
1da177e4 314 if (!(skb = alloc_skb(len + align, GFP_KERNEL))) {
09f75cd7 315 tun->dev->stats.rx_dropped++;
1da177e4
LT		 316 return -ENOMEM;
317 }
318
319 if (align)
320 skb_reserve(skb, align);
8f22757e 321 if (memcpy_fromiovec(skb_put(skb, len), iv, len)) {
09f75cd7 322 tun->dev->stats.rx_dropped++;
8f22757e 323 kfree_skb(skb);
1da177e4 324 return -EFAULT;
8f22757e 325 }
1da177e4 326
f43798c2
RR		 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
1da177e4
LT		 337 switch (tun->flags & TUN_TYPE_MASK) {
338 case TUN_TUN_DEV:
f09f7ee2
AWC		 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
459a98ed 354 skb_reset_mac_header(skb);
1da177e4 355 skb->protocol = pi.proto;
4c13eb66 356 skb->dev = tun->dev;
1da177e4
LT		 357 break;
358 case TUN_TAP_DEV:
359 skb->protocol = eth_type_trans(skb, tun->dev);
360 break;
361 };
362
f43798c2
RR		 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 }
6aa20a22 392
1da177e4
LT		 393 netif_rx_ni(skb);
394 tun->dev->last_rx = jiffies;
6aa20a22 395
09f75cd7
JG		 396 tun->dev->stats.rx_packets++;
397 tun->dev->stats.rx_bytes += len;
1da177e4
LT		 398
399 return count;
6aa20a22 400}
1da177e4 401
ee0b3e67
BP		 402static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
403 unsigned long count, loff_t pos)
1da177e4 404{
ee0b3e67 405 struct tun_struct *tun = iocb->ki_filp->private_data;
1da177e4
LT		 406
407 if (!tun)
408 return -EBADFD;
409
410 DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
411
52427c9d 412 return tun_get_user(tun, (struct iovec *) iv, iov_length(iv, count));
1da177e4
LT		 413}
414
1da177e4
LT		 415/* Put packet to the user space buffer */
416static __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 }
6aa20a22 431
1da177e4
LT		 432 if (memcpy_toiovec(iv, (void *) &pi, sizeof(pi)))
433 return -EFAULT;
434 total += sizeof(pi);
6aa20a22 435 }
1da177e4 436
f43798c2
RR		 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
1da177e4
LT		 470 len = min_t(int, skb->len, len);
471
472 skb_copy_datagram_iovec(skb, 0, iv, len);
473 total += len;
474
09f75cd7
JG		 475 tun->dev->stats.tx_packets++;
476 tun->dev->stats.tx_bytes += len;
1da177e4
LT		 477
478 return total;
479}
480
ee0b3e67
BP		 481static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
482 unsigned long count, loff_t pos)
1da177e4 483{
ee0b3e67 484 struct file *file = iocb->ki_filp;
1da177e4
LT		 485 struct tun_struct *tun = file->private_data;
486 DECLARE_WAITQUEUE(wait, current);
487 struct sk_buff *skb;
488 ssize_t len, ret = 0;
0795af57 489 DECLARE_MAC_BUF(mac);
1da177e4
LT		 490
491 if (!tun)
492 return -EBADFD;
493
494 DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
495
52427c9d 496 len = iov_length(iv, count);
1da177e4
LT		 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 */
d626f62b
ACM		 534 skb_copy_from_linear_data(skb, addr, min_t(size_t, sizeof addr,
535 skb->len));
1da177e4
LT		 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)))))) {
0795af57
JP		 544 DBG(KERN_DEBUG "%s: tun_chr_readv: accepted: %s\n",
545 tun->dev->name, print_mac(mac, addr));
1da177e4
LT		 546 ret = tun_put_user(tun, skb, (struct iovec *) iv, len);
547 kfree_skb(skb);
548 break;
549 } else {
0795af57
JP		 550 DBG(KERN_DEBUG "%s: tun_chr_readv: rejected: %s\n",
551 tun->dev->name, print_mac(mac, addr));
1da177e4
LT		 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
1da177e4
LT		 563static 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;
8c644623 571 tun->group = -1;
1da177e4 572
1da177e4
LT		 573 dev->open = tun_net_open;
574 dev->hard_start_xmit = tun_net_xmit;
575 dev->stop = tun_net_close;
1da177e4
LT		 576 dev->ethtool_ops = &tun_ethtool_ops;
577 dev->destructor = free_netdev;
fc54c658 578 dev->features |= NETIF_F_NETNS_LOCAL;
1da177e4
LT		 579}
580
d647a591 581static struct tun_struct *tun_get_by_name(struct tun_net *tn, const char *name)
1da177e4
LT		 582{
583 struct tun_struct *tun;
584
585 ASSERT_RTNL();
d647a591 586 list_for_each_entry(tun, &tn->dev_list, list) {
1da177e4
LT		 587 if (!strncmp(tun->dev->name, name, IFNAMSIZ))
588 return tun;
589 }
590
591 return NULL;
592}
593
d647a591 594static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
1da177e4 595{
d647a591 596 struct tun_net *tn;
1da177e4
LT		 597 struct tun_struct *tun;
598 struct net_device *dev;
599 int err;
600
d647a591
PE		 601 tn = net_generic(net, tun_net_id);
602 tun = tun_get_by_name(tn, ifr->ifr_name);
1da177e4
LT		 603 if (tun) {
604 if (tun->attached)
605 return -EBUSY;
606
607 /* Check permissions */
8c644623
GG		 608 if (((tun->owner != -1 &&
609 current->euid != tun->owner) ||
610 (tun->group != -1 &&
611 current->egid != tun->group)) &&
612 !capable(CAP_NET_ADMIN))
1da177e4 613 return -EPERM;
6aa20a22 614 }
d647a591 615 else if (__dev_get_by_name(net, ifr->ifr_name))
1da177e4
LT		 616 return -EINVAL;
617 else {
618 char *name;
619 unsigned long flags = 0;
620
621 err = -EINVAL;
622
ca6bb5d7
DW		 623 if (!capable(CAP_NET_ADMIN))
624 return -EPERM;
625
1da177e4
LT		 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";
6aa20a22 635 } else
1da177e4 636 goto failed;
6aa20a22 637
1da177e4
LT		 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
fc54c658 646 dev_net_set(dev, net);
1da177e4
LT		 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. */
a3edb083 653 *(__be16 *)tun->dev_addr = htons(0x00FF);
1da177e4
LT		 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;
6aa20a22 668
d647a591 669 list_add(&tun->list, &tn->dev_list);
1da177e4
LT		 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;
a26af1e0
NF		 676 else
677 tun->flags &= ~TUN_NO_PI;
1da177e4
LT		 678
679 if (ifr->ifr_flags & IFF_ONE_QUEUE)
680 tun->flags |= TUN_ONE_QUEUE;
a26af1e0
NF		 681 else
682 tun->flags &= ~TUN_ONE_QUEUE;
1da177e4 683
f43798c2
RR		 684 if (ifr->ifr_flags & IFF_VNET_HDR)
685 tun->flags |= TUN_VNET_HDR;
686 else
687 tun->flags &= ~TUN_VNET_HDR;
688
1da177e4
LT		 689 file->private_data = tun;
690 tun->attached = 1;
fc54c658 691 get_net(dev_net(tun->dev));
1da177e4
LT		 692
693 strcpy(ifr->ifr_name, tun->dev->name);
694 return 0;
695
696 err_free_dev:
697 free_netdev(dev);
698 failed:
699 return err;
700}
701
5228ddc9
RR		 702/* This is like a cut-down ethtool ops, except done via tun fd so no
703 * privs required. */
704static int set_offload(struct net_device *dev, unsigned long arg)
705{
706 unsigned int old_features, features;
707
708 old_features = dev->features;
709 /* Unset features, set them as we chew on the arg. */
710 features = (old_features & ~(NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST
711 |NETIF_F_TSO_ECN|NETIF_F_TSO|NETIF_F_TSO6));
712
713 if (arg & TUN_F_CSUM) {
714 features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
715 arg &= ~TUN_F_CSUM;
716
717 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
718 if (arg & TUN_F_TSO_ECN) {
719 features |= NETIF_F_TSO_ECN;
720 arg &= ~TUN_F_TSO_ECN;
721 }
722 if (arg & TUN_F_TSO4)
723 features |= NETIF_F_TSO;
724 if (arg & TUN_F_TSO6)
725 features |= NETIF_F_TSO6;
726 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
727 }
728 }
729
730 /* This gives the user a way to test for new features in future by
731 * trying to set them. */
732 if (arg)
733 return -EINVAL;
734
735 dev->features = features;
736 if (old_features != dev->features)
737 netdev_features_change(dev);
738
739 return 0;
740}
741
6aa20a22 742static int tun_chr_ioctl(struct inode *inode, struct file *file,
1da177e4
LT		 743 unsigned int cmd, unsigned long arg)
744{
745 struct tun_struct *tun = file->private_data;
746 void __user* argp = (void __user*)arg;
747 struct ifreq ifr;
0795af57 748 DECLARE_MAC_BUF(mac);
1da177e4
LT		 749
750 if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
751 if (copy_from_user(&ifr, argp, sizeof ifr))
752 return -EFAULT;
753
754 if (cmd == TUNSETIFF && !tun) {
755 int err;
756
757 ifr.ifr_name[IFNAMSIZ-1] = '\0';
758
759 rtnl_lock();
d647a591 760 err = tun_set_iff(current->nsproxy->net_ns, file, &ifr);
1da177e4
LT		 761 rtnl_unlock();
762
763 if (err)
764 return err;
765
766 if (copy_to_user(argp, &ifr, sizeof(ifr)))
767 return -EFAULT;
768 return 0;
769 }
770
07240fd0
RR		 771 if (cmd == TUNGETFEATURES) {
772 /* Currently this just means: "what IFF flags are valid?".
773 * This is needed because we never checked for invalid flags on
774 * TUNSETIFF. */
f43798c2
RR		 775 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
776 IFF_VNET_HDR,
07240fd0
RR		 777 (unsigned int __user*)argp);
778 }
779
1da177e4
LT		 780 if (!tun)
781 return -EBADFD;
782
783 DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
784
785 switch (cmd) {
786 case TUNSETNOCSUM:
787 /* Disable/Enable checksum */
788 if (arg)
789 tun->flags |= TUN_NOCHECKSUM;
790 else
791 tun->flags &= ~TUN_NOCHECKSUM;
792
793 DBG(KERN_INFO "%s: checksum %s\n",
794 tun->dev->name, arg ? "disabled" : "enabled");
795 break;
796
797 case TUNSETPERSIST:
798 /* Disable/Enable persist mode */
799 if (arg)
800 tun->flags |= TUN_PERSIST;
801 else
802 tun->flags &= ~TUN_PERSIST;
803
804 DBG(KERN_INFO "%s: persist %s\n",
c6e991de 805 tun->dev->name, arg ? "enabled" : "disabled");
1da177e4
LT		 806 break;
807
808 case TUNSETOWNER:
809 /* Set owner of the device */
810 tun->owner = (uid_t) arg;
811
812 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
813 break;
814
8c644623
GG		 815 case TUNSETGROUP:
816 /* Set group of the device */
817 tun->group= (gid_t) arg;
818
819 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group);
820 break;
821
ff4cc3ac 822 case TUNSETLINK:
48abfe05
DM		 823 {
824 int ret;
825
ff4cc3ac 826 /* Only allow setting the type when the interface is down */
48abfe05 827 rtnl_lock();
ff4cc3ac
MK		 828 if (tun->dev->flags & IFF_UP) {
829 DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
830 tun->dev->name);
48abfe05 831 ret = -EBUSY;
ff4cc3ac
MK		 832 } else {
833 tun->dev->type = (int) arg;
834 DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
48abfe05 835 ret = 0;
ff4cc3ac 836 }
48abfe05
DM		 837 rtnl_unlock();
838 return ret;
839 }
ff4cc3ac 840
1da177e4
LT		 841#ifdef TUN_DEBUG
842 case TUNSETDEBUG:
843 tun->debug = arg;
844 break;
845#endif
846
5228ddc9
RR		 847 case TUNSETOFFLOAD:
848 {
849 int ret;
850 rtnl_lock();
851 ret = set_offload(tun->dev, arg);
852 rtnl_unlock();
853 return ret;
854 }
855
1da177e4
LT		 856 case SIOCGIFFLAGS:
857 ifr.ifr_flags = tun->if_flags;
858 if (copy_to_user( argp, &ifr, sizeof ifr))
859 return -EFAULT;
860 return 0;
861
862 case SIOCSIFFLAGS:
863 /** Set the character device's interface flags. Currently only
864 * IFF_PROMISC and IFF_ALLMULTI are used. */
865 tun->if_flags = ifr.ifr_flags;
866 DBG(KERN_INFO "%s: interface flags 0x%lx\n",
867 tun->dev->name, tun->if_flags);
868 return 0;
869
870 case SIOCGIFHWADDR:
36226a8d 871 /* Note: the actual net device's address may be different */
1da177e4
LT		 872 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev_addr,
873 min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
874 if (copy_to_user( argp, &ifr, sizeof ifr))
875 return -EFAULT;
876 return 0;
877
878 case SIOCSIFHWADDR:
36226a8d
BB		 879 {
880 /* try to set the actual net device's hw address */
40102371
KH		 881 int ret;
882
883 rtnl_lock();
884 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
885 rtnl_unlock();
36226a8d
BB		 886
887 if (ret == 0) {
888 /** Set the character device's hardware address. This is used when
889 * filtering packets being sent from the network device to the character
890 * device. */
891 memcpy(tun->dev_addr, ifr.ifr_hwaddr.sa_data,
892 min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
893 DBG(KERN_DEBUG "%s: set hardware address: %x:%x:%x:%x:%x:%x\n",
894 tun->dev->name,
895 tun->dev_addr[0], tun->dev_addr[1], tun->dev_addr[2],
896 tun->dev_addr[3], tun->dev_addr[4], tun->dev_addr[5]);
897 }
898
899 return ret;
900 }
1da177e4
LT		 901
902 case SIOCADDMULTI:
903 /** Add the specified group to the character device's multicast filter
904 * list. */
9edb74cc
DM		 905 rtnl_lock();
906 netif_tx_lock_bh(tun->dev);
1da177e4 907 add_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
9edb74cc
DM		 908 netif_tx_unlock_bh(tun->dev);
909 rtnl_unlock();
910
0795af57
JP		 911 DBG(KERN_DEBUG "%s: add multi: %s\n",
912 tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data));
1da177e4
LT		 913 return 0;
914
915 case SIOCDELMULTI:
916 /** Remove the specified group from the character device's multicast
917 * filter list. */
9edb74cc
DM		 918 rtnl_lock();
919 netif_tx_lock_bh(tun->dev);
1da177e4 920 del_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
9edb74cc
DM		 921 netif_tx_unlock_bh(tun->dev);
922 rtnl_unlock();
923
0795af57
JP		 924 DBG(KERN_DEBUG "%s: del multi: %s\n",
925 tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data));
1da177e4
LT		 926 return 0;
927
928 default:
929 return -EINVAL;
930 };
931
932 return 0;
933}
934
935static int tun_chr_fasync(int fd, struct file *file, int on)
936{
937 struct tun_struct *tun = file->private_data;
938 int ret;
939
940 if (!tun)
941 return -EBADFD;
942
943 DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
944
945 if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
6aa20a22
JG		 946 return ret;
947
1da177e4 948 if (on) {
609d7fa9 949 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
1da177e4
LT		 950 if (ret)
951 return ret;
952 tun->flags |= TUN_FASYNC;
6aa20a22 953 } else
1da177e4
LT		 954 tun->flags &= ~TUN_FASYNC;
955
956 return 0;
957}
958
959static int tun_chr_open(struct inode *inode, struct file * file)
960{
961 DBG1(KERN_INFO "tunX: tun_chr_open\n");
962 file->private_data = NULL;
963 return 0;
964}
965
966static int tun_chr_close(struct inode *inode, struct file *file)
967{
968 struct tun_struct *tun = file->private_data;
969
970 if (!tun)
971 return 0;
972
973 DBG(KERN_INFO "%s: tun_chr_close\n", tun->dev->name);
974
975 tun_chr_fasync(-1, file, 0);
976
977 rtnl_lock();
978
979 /* Detach from net device */
980 file->private_data = NULL;
981 tun->attached = 0;
fc54c658 982 put_net(dev_net(tun->dev));
1da177e4
LT		 983
984 /* Drop read queue */
985 skb_queue_purge(&tun->readq);
986
987 if (!(tun->flags & TUN_PERSIST)) {
988 list_del(&tun->list);
989 unregister_netdevice(tun->dev);
990 }
991
992 rtnl_unlock();
993
994 return 0;
995}
996
d54b1fdb 997static const struct file_operations tun_fops = {
6aa20a22 998 .owner = THIS_MODULE,
1da177e4 999 .llseek = no_llseek,
ee0b3e67
BP		 1000 .read = do_sync_read,
1001 .aio_read = tun_chr_aio_read,
1002 .write = do_sync_write,
1003 .aio_write = tun_chr_aio_write,
1da177e4
LT		 1004 .poll = tun_chr_poll,
1005 .ioctl = tun_chr_ioctl,
1006 .open = tun_chr_open,
1007 .release = tun_chr_close,
6aa20a22 1008 .fasync = tun_chr_fasync
1da177e4
LT		 1009};
1010
1011static struct miscdevice tun_miscdev = {
1012 .minor = TUN_MINOR,
1013 .name = "tun",
1014 .fops = &tun_fops,
1da177e4
LT		 1015};
1016
1017/* ethtool interface */
1018
1019static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1020{
1021 cmd->supported = 0;
1022 cmd->advertising = 0;
1023 cmd->speed = SPEED_10;
1024 cmd->duplex = DUPLEX_FULL;
1025 cmd->port = PORT_TP;
1026 cmd->phy_address = 0;
1027 cmd->transceiver = XCVR_INTERNAL;
1028 cmd->autoneg = AUTONEG_DISABLE;
1029 cmd->maxtxpkt = 0;
1030 cmd->maxrxpkt = 0;
1031 return 0;
1032}
1033
1034static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
1035{
1036 struct tun_struct *tun = netdev_priv(dev);
1037
1038 strcpy(info->driver, DRV_NAME);
1039 strcpy(info->version, DRV_VERSION);
1040 strcpy(info->fw_version, "N/A");
1041
1042 switch (tun->flags & TUN_TYPE_MASK) {
1043 case TUN_TUN_DEV:
1044 strcpy(info->bus_info, "tun");
1045 break;
1046 case TUN_TAP_DEV:
1047 strcpy(info->bus_info, "tap");
1048 break;
1049 }
1050}
1051
1052static u32 tun_get_msglevel(struct net_device *dev)
1053{
1054#ifdef TUN_DEBUG
1055 struct tun_struct *tun = netdev_priv(dev);
1056 return tun->debug;
1057#else
1058 return -EOPNOTSUPP;
1059#endif
1060}
1061
1062static void tun_set_msglevel(struct net_device *dev, u32 value)
1063{
1064#ifdef TUN_DEBUG
1065 struct tun_struct *tun = netdev_priv(dev);
1066 tun->debug = value;
1067#endif
1068}
1069
1070static u32 tun_get_link(struct net_device *dev)
1071{
1072 struct tun_struct *tun = netdev_priv(dev);
1073 return tun->attached;
1074}
1075
1076static u32 tun_get_rx_csum(struct net_device *dev)
1077{
1078 struct tun_struct *tun = netdev_priv(dev);
1079 return (tun->flags & TUN_NOCHECKSUM) == 0;
1080}
1081
1082static int tun_set_rx_csum(struct net_device *dev, u32 data)
1083{
1084 struct tun_struct *tun = netdev_priv(dev);
1085 if (data)
1086 tun->flags &= ~TUN_NOCHECKSUM;
1087 else
1088 tun->flags |= TUN_NOCHECKSUM;
1089 return 0;
1090}
1091
7282d491 1092static const struct ethtool_ops tun_ethtool_ops = {
1da177e4
LT		 1093 .get_settings = tun_get_settings,
1094 .get_drvinfo = tun_get_drvinfo,
1095 .get_msglevel = tun_get_msglevel,
1096 .set_msglevel = tun_set_msglevel,
1097 .get_link = tun_get_link,
1098 .get_rx_csum = tun_get_rx_csum,
1099 .set_rx_csum = tun_set_rx_csum
1100};
1101
79d17604
PE		 1102static int tun_init_net(struct net *net)
1103{
1104 struct tun_net *tn;
1105
1106 tn = kmalloc(sizeof(*tn), GFP_KERNEL);
1107 if (tn == NULL)
1108 return -ENOMEM;
1109
1110 INIT_LIST_HEAD(&tn->dev_list);
1111
1112 if (net_assign_generic(net, tun_net_id, tn)) {
1113 kfree(tn);
1114 return -ENOMEM;
1115 }
1116
1117 return 0;
1118}
1119
1120static void tun_exit_net(struct net *net)
1121{
1122 struct tun_net *tn;
d647a591 1123 struct tun_struct *tun, *nxt;
79d17604
PE		 1124
1125 tn = net_generic(net, tun_net_id);
d647a591
PE		 1126
1127 rtnl_lock();
1128 list_for_each_entry_safe(tun, nxt, &tn->dev_list, list) {
1129 DBG(KERN_INFO "%s cleaned up\n", tun->dev->name);
1130 unregister_netdevice(tun->dev);
1131 }
1132 rtnl_unlock();
1133
79d17604
PE		 1134 kfree(tn);
1135}
1136
1137static struct pernet_operations tun_net_ops = {
1138 .init = tun_init_net,
1139 .exit = tun_exit_net,
1140};
1141
1da177e4
LT		 1142static int __init tun_init(void)
1143{
1144 int ret = 0;
1145
1146 printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
1147 printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
1148
79d17604
PE		 1149 ret = register_pernet_gen_device(&tun_net_id, &tun_net_ops);
1150 if (ret) {
1151 printk(KERN_ERR "tun: Can't register pernet ops\n");
1152 goto err_pernet;
1153 }
1154
1da177e4 1155 ret = misc_register(&tun_miscdev);
79d17604 1156 if (ret) {
1da177e4 1157 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
79d17604
PE		 1158 goto err_misc;
1159 }
1160 return 0;
1161
1162err_misc:
1163 unregister_pernet_gen_device(tun_net_id, &tun_net_ops);
1164err_pernet:
1da177e4
LT		 1165 return ret;
1166}
1167
1168static void tun_cleanup(void)
1169{
6aa20a22 1170 misc_deregister(&tun_miscdev);
79d17604 1171 unregister_pernet_gen_device(tun_net_id, &tun_net_ops);
1da177e4
LT		 1172}
1173
1174module_init(tun_init);
1175module_exit(tun_cleanup);
1176MODULE_DESCRIPTION(DRV_DESCRIPTION);
1177MODULE_AUTHOR(DRV_COPYRIGHT);
1178MODULE_LICENSE("GPL");
1179MODULE_ALIAS_MISCDEV(TUN_MINOR);
Linux 6.x block layer and io_uring tree(s)