Merge branch 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus
[linux-2.6] / 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  *  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 /* Get packet from user space buffer */
362 static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, size_t count)
363 {
364         struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) };
365         struct sk_buff *skb;
366         size_t len = count, align = 0;
367         struct virtio_net_hdr gso = { 0 };
368
369         if (!(tun->flags & TUN_NO_PI)) {
370                 if ((len -= sizeof(pi)) > count)
371                         return -EINVAL;
372
373                 if(memcpy_fromiovec((void *)&pi, iv, sizeof(pi)))
374                         return -EFAULT;
375         }
376
377         if (tun->flags & TUN_VNET_HDR) {
378                 if ((len -= sizeof(gso)) > count)
379                         return -EINVAL;
380
381                 if (memcpy_fromiovec((void *)&gso, iv, sizeof(gso)))
382                         return -EFAULT;
383
384                 if (gso.hdr_len > len)
385                         return -EINVAL;
386         }
387
388         if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
389                 align = NET_IP_ALIGN;
390                 if (unlikely(len < ETH_HLEN))
391                         return -EINVAL;
392         }
393
394         if (!(skb = alloc_skb(len + align, GFP_KERNEL))) {
395                 tun->dev->stats.rx_dropped++;
396                 return -ENOMEM;
397         }
398
399         if (align)
400                 skb_reserve(skb, align);
401         if (memcpy_fromiovec(skb_put(skb, len), iv, len)) {
402                 tun->dev->stats.rx_dropped++;
403                 kfree_skb(skb);
404                 return -EFAULT;
405         }
406
407         if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
408                 if (!skb_partial_csum_set(skb, gso.csum_start,
409                                           gso.csum_offset)) {
410                         tun->dev->stats.rx_frame_errors++;
411                         kfree_skb(skb);
412                         return -EINVAL;
413                 }
414         } else if (tun->flags & TUN_NOCHECKSUM)
415                 skb->ip_summed = CHECKSUM_UNNECESSARY;
416
417         switch (tun->flags & TUN_TYPE_MASK) {
418         case TUN_TUN_DEV:
419                 if (tun->flags & TUN_NO_PI) {
420                         switch (skb->data[0] & 0xf0) {
421                         case 0x40:
422                                 pi.proto = htons(ETH_P_IP);
423                                 break;
424                         case 0x60:
425                                 pi.proto = htons(ETH_P_IPV6);
426                                 break;
427                         default:
428                                 tun->dev->stats.rx_dropped++;
429                                 kfree_skb(skb);
430                                 return -EINVAL;
431                         }
432                 }
433
434                 skb_reset_mac_header(skb);
435                 skb->protocol = pi.proto;
436                 skb->dev = tun->dev;
437                 break;
438         case TUN_TAP_DEV:
439                 skb->protocol = eth_type_trans(skb, tun->dev);
440                 break;
441         };
442
443         if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
444                 pr_debug("GSO!\n");
445                 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
446                 case VIRTIO_NET_HDR_GSO_TCPV4:
447                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
448                         break;
449                 case VIRTIO_NET_HDR_GSO_TCPV6:
450                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
451                         break;
452                 default:
453                         tun->dev->stats.rx_frame_errors++;
454                         kfree_skb(skb);
455                         return -EINVAL;
456                 }
457
458                 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
459                         skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
460
461                 skb_shinfo(skb)->gso_size = gso.gso_size;
462                 if (skb_shinfo(skb)->gso_size == 0) {
463                         tun->dev->stats.rx_frame_errors++;
464                         kfree_skb(skb);
465                         return -EINVAL;
466                 }
467
468                 /* Header must be checked, and gso_segs computed. */
469                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
470                 skb_shinfo(skb)->gso_segs = 0;
471         }
472
473         netif_rx_ni(skb);
474         tun->dev->last_rx = jiffies;
475
476         tun->dev->stats.rx_packets++;
477         tun->dev->stats.rx_bytes += len;
478
479         return count;
480 }
481
482 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
483                               unsigned long count, loff_t pos)
484 {
485         struct tun_struct *tun = iocb->ki_filp->private_data;
486
487         if (!tun)
488                 return -EBADFD;
489
490         DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
491
492         return tun_get_user(tun, (struct iovec *) iv, iov_length(iv, count));
493 }
494
495 /* Put packet to the user space buffer */
496 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
497                                        struct sk_buff *skb,
498                                        struct iovec *iv, int len)
499 {
500         struct tun_pi pi = { 0, skb->protocol };
501         ssize_t total = 0;
502
503         if (!(tun->flags & TUN_NO_PI)) {
504                 if ((len -= sizeof(pi)) < 0)
505                         return -EINVAL;
506
507                 if (len < skb->len) {
508                         /* Packet will be striped */
509                         pi.flags |= TUN_PKT_STRIP;
510                 }
511
512                 if (memcpy_toiovec(iv, (void *) &pi, sizeof(pi)))
513                         return -EFAULT;
514                 total += sizeof(pi);
515         }
516
517         if (tun->flags & TUN_VNET_HDR) {
518                 struct virtio_net_hdr gso = { 0 }; /* no info leak */
519                 if ((len -= sizeof(gso)) < 0)
520                         return -EINVAL;
521
522                 if (skb_is_gso(skb)) {
523                         struct skb_shared_info *sinfo = skb_shinfo(skb);
524
525                         /* This is a hint as to how much should be linear. */
526                         gso.hdr_len = skb_headlen(skb);
527                         gso.gso_size = sinfo->gso_size;
528                         if (sinfo->gso_type & SKB_GSO_TCPV4)
529                                 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
530                         else if (sinfo->gso_type & SKB_GSO_TCPV6)
531                                 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
532                         else
533                                 BUG();
534                         if (sinfo->gso_type & SKB_GSO_TCP_ECN)
535                                 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
536                 } else
537                         gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
538
539                 if (skb->ip_summed == CHECKSUM_PARTIAL) {
540                         gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
541                         gso.csum_start = skb->csum_start - skb_headroom(skb);
542                         gso.csum_offset = skb->csum_offset;
543                 } /* else everything is zero */
544
545                 if (unlikely(memcpy_toiovec(iv, (void *)&gso, sizeof(gso))))
546                         return -EFAULT;
547                 total += sizeof(gso);
548         }
549
550         len = min_t(int, skb->len, len);
551
552         skb_copy_datagram_iovec(skb, 0, iv, len);
553         total += len;
554
555         tun->dev->stats.tx_packets++;
556         tun->dev->stats.tx_bytes += len;
557
558         return total;
559 }
560
561 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
562                             unsigned long count, loff_t pos)
563 {
564         struct file *file = iocb->ki_filp;
565         struct tun_struct *tun = file->private_data;
566         DECLARE_WAITQUEUE(wait, current);
567         struct sk_buff *skb;
568         ssize_t len, ret = 0;
569
570         if (!tun)
571                 return -EBADFD;
572
573         DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
574
575         len = iov_length(iv, count);
576         if (len < 0)
577                 return -EINVAL;
578
579         add_wait_queue(&tun->read_wait, &wait);
580         while (len) {
581                 current->state = TASK_INTERRUPTIBLE;
582
583                 /* Read frames from the queue */
584                 if (!(skb=skb_dequeue(&tun->readq))) {
585                         if (file->f_flags & O_NONBLOCK) {
586                                 ret = -EAGAIN;
587                                 break;
588                         }
589                         if (signal_pending(current)) {
590                                 ret = -ERESTARTSYS;
591                                 break;
592                         }
593
594                         /* Nothing to read, let's sleep */
595                         schedule();
596                         continue;
597                 }
598                 netif_wake_queue(tun->dev);
599
600                 ret = tun_put_user(tun, skb, (struct iovec *) iv, len);
601                 kfree_skb(skb);
602                 break;
603         }
604
605         current->state = TASK_RUNNING;
606         remove_wait_queue(&tun->read_wait, &wait);
607
608         return ret;
609 }
610
611 static void tun_setup(struct net_device *dev)
612 {
613         struct tun_struct *tun = netdev_priv(dev);
614
615         skb_queue_head_init(&tun->readq);
616         init_waitqueue_head(&tun->read_wait);
617
618         tun->owner = -1;
619         tun->group = -1;
620
621         dev->open = tun_net_open;
622         dev->hard_start_xmit = tun_net_xmit;
623         dev->stop = tun_net_close;
624         dev->ethtool_ops = &tun_ethtool_ops;
625         dev->destructor = free_netdev;
626         dev->features |= NETIF_F_NETNS_LOCAL;
627 }
628
629 static struct tun_struct *tun_get_by_name(struct tun_net *tn, const char *name)
630 {
631         struct tun_struct *tun;
632
633         ASSERT_RTNL();
634         list_for_each_entry(tun, &tn->dev_list, list) {
635                 if (!strncmp(tun->dev->name, name, IFNAMSIZ))
636                     return tun;
637         }
638
639         return NULL;
640 }
641
642 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
643 {
644         struct tun_net *tn;
645         struct tun_struct *tun;
646         struct net_device *dev;
647         int err;
648
649         tn = net_generic(net, tun_net_id);
650         tun = tun_get_by_name(tn, ifr->ifr_name);
651         if (tun) {
652                 if (tun->attached)
653                         return -EBUSY;
654
655                 /* Check permissions */
656                 if (((tun->owner != -1 &&
657                       current->euid != tun->owner) ||
658                      (tun->group != -1 &&
659                       current->egid != tun->group)) &&
660                      !capable(CAP_NET_ADMIN))
661                         return -EPERM;
662         }
663         else if (__dev_get_by_name(net, ifr->ifr_name))
664                 return -EINVAL;
665         else {
666                 char *name;
667                 unsigned long flags = 0;
668
669                 err = -EINVAL;
670
671                 if (!capable(CAP_NET_ADMIN))
672                         return -EPERM;
673
674                 /* Set dev type */
675                 if (ifr->ifr_flags & IFF_TUN) {
676                         /* TUN device */
677                         flags |= TUN_TUN_DEV;
678                         name = "tun%d";
679                 } else if (ifr->ifr_flags & IFF_TAP) {
680                         /* TAP device */
681                         flags |= TUN_TAP_DEV;
682                         name = "tap%d";
683                 } else
684                         goto failed;
685
686                 if (*ifr->ifr_name)
687                         name = ifr->ifr_name;
688
689                 dev = alloc_netdev(sizeof(struct tun_struct), name,
690                                    tun_setup);
691                 if (!dev)
692                         return -ENOMEM;
693
694                 dev_net_set(dev, net);
695                 tun = netdev_priv(dev);
696                 tun->dev = dev;
697                 tun->flags = flags;
698                 tun->txflt.count = 0;
699
700                 tun_net_init(dev);
701
702                 if (strchr(dev->name, '%')) {
703                         err = dev_alloc_name(dev, dev->name);
704                         if (err < 0)
705                                 goto err_free_dev;
706                 }
707
708                 err = register_netdevice(tun->dev);
709                 if (err < 0)
710                         goto err_free_dev;
711
712                 list_add(&tun->list, &tn->dev_list);
713         }
714
715         DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
716
717         if (ifr->ifr_flags & IFF_NO_PI)
718                 tun->flags |= TUN_NO_PI;
719         else
720                 tun->flags &= ~TUN_NO_PI;
721
722         if (ifr->ifr_flags & IFF_ONE_QUEUE)
723                 tun->flags |= TUN_ONE_QUEUE;
724         else
725                 tun->flags &= ~TUN_ONE_QUEUE;
726
727         if (ifr->ifr_flags & IFF_VNET_HDR)
728                 tun->flags |= TUN_VNET_HDR;
729         else
730                 tun->flags &= ~TUN_VNET_HDR;
731
732         file->private_data = tun;
733         tun->attached = 1;
734         get_net(dev_net(tun->dev));
735
736         /* Make sure persistent devices do not get stuck in
737          * xoff state.
738          */
739         if (netif_running(tun->dev))
740                 netif_wake_queue(tun->dev);
741
742         strcpy(ifr->ifr_name, tun->dev->name);
743         return 0;
744
745  err_free_dev:
746         free_netdev(dev);
747  failed:
748         return err;
749 }
750
751 /* This is like a cut-down ethtool ops, except done via tun fd so no
752  * privs required. */
753 static int set_offload(struct net_device *dev, unsigned long arg)
754 {
755         unsigned int old_features, features;
756
757         old_features = dev->features;
758         /* Unset features, set them as we chew on the arg. */
759         features = (old_features & ~(NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST
760                                     |NETIF_F_TSO_ECN|NETIF_F_TSO|NETIF_F_TSO6));
761
762         if (arg & TUN_F_CSUM) {
763                 features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
764                 arg &= ~TUN_F_CSUM;
765
766                 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
767                         if (arg & TUN_F_TSO_ECN) {
768                                 features |= NETIF_F_TSO_ECN;
769                                 arg &= ~TUN_F_TSO_ECN;
770                         }
771                         if (arg & TUN_F_TSO4)
772                                 features |= NETIF_F_TSO;
773                         if (arg & TUN_F_TSO6)
774                                 features |= NETIF_F_TSO6;
775                         arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
776                 }
777         }
778
779         /* This gives the user a way to test for new features in future by
780          * trying to set them. */
781         if (arg)
782                 return -EINVAL;
783
784         dev->features = features;
785         if (old_features != dev->features)
786                 netdev_features_change(dev);
787
788         return 0;
789 }
790
791 static int tun_chr_ioctl(struct inode *inode, struct file *file,
792                          unsigned int cmd, unsigned long arg)
793 {
794         struct tun_struct *tun = file->private_data;
795         void __user* argp = (void __user*)arg;
796         struct ifreq ifr;
797         int ret;
798         DECLARE_MAC_BUF(mac);
799
800         if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
801                 if (copy_from_user(&ifr, argp, sizeof ifr))
802                         return -EFAULT;
803
804         if (cmd == TUNSETIFF && !tun) {
805                 int err;
806
807                 ifr.ifr_name[IFNAMSIZ-1] = '\0';
808
809                 rtnl_lock();
810                 err = tun_set_iff(current->nsproxy->net_ns, file, &ifr);
811                 rtnl_unlock();
812
813                 if (err)
814                         return err;
815
816                 if (copy_to_user(argp, &ifr, sizeof(ifr)))
817                         return -EFAULT;
818                 return 0;
819         }
820
821         if (cmd == TUNGETFEATURES) {
822                 /* Currently this just means: "what IFF flags are valid?".
823                  * This is needed because we never checked for invalid flags on
824                  * TUNSETIFF. */
825                 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
826                                 IFF_VNET_HDR,
827                                 (unsigned int __user*)argp);
828         }
829
830         if (!tun)
831                 return -EBADFD;
832
833         DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
834
835         switch (cmd) {
836         case TUNSETNOCSUM:
837                 /* Disable/Enable checksum */
838                 if (arg)
839                         tun->flags |= TUN_NOCHECKSUM;
840                 else
841                         tun->flags &= ~TUN_NOCHECKSUM;
842
843                 DBG(KERN_INFO "%s: checksum %s\n",
844                     tun->dev->name, arg ? "disabled" : "enabled");
845                 break;
846
847         case TUNSETPERSIST:
848                 /* Disable/Enable persist mode */
849                 if (arg)
850                         tun->flags |= TUN_PERSIST;
851                 else
852                         tun->flags &= ~TUN_PERSIST;
853
854                 DBG(KERN_INFO "%s: persist %s\n",
855                     tun->dev->name, arg ? "enabled" : "disabled");
856                 break;
857
858         case TUNSETOWNER:
859                 /* Set owner of the device */
860                 tun->owner = (uid_t) arg;
861
862                 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
863                 break;
864
865         case TUNSETGROUP:
866                 /* Set group of the device */
867                 tun->group= (gid_t) arg;
868
869                 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group);
870                 break;
871
872         case TUNSETLINK:
873                 /* Only allow setting the type when the interface is down */
874                 rtnl_lock();
875                 if (tun->dev->flags & IFF_UP) {
876                         DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
877                                 tun->dev->name);
878                         ret = -EBUSY;
879                 } else {
880                         tun->dev->type = (int) arg;
881                         DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
882                         ret = 0;
883                 }
884                 rtnl_unlock();
885                 return ret;
886
887 #ifdef TUN_DEBUG
888         case TUNSETDEBUG:
889                 tun->debug = arg;
890                 break;
891 #endif
892         case TUNSETOFFLOAD:
893                 rtnl_lock();
894                 ret = set_offload(tun->dev, arg);
895                 rtnl_unlock();
896                 return ret;
897
898         case TUNSETTXFILTER:
899                 /* Can be set only for TAPs */
900                 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
901                         return -EINVAL;
902                 rtnl_lock();
903                 ret = update_filter(&tun->txflt, (void *) __user arg);
904                 rtnl_unlock();
905                 return ret;
906
907         case SIOCGIFHWADDR:
908                 /* Get hw addres */
909                 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
910                 ifr.ifr_hwaddr.sa_family = tun->dev->type;
911                 if (copy_to_user(argp, &ifr, sizeof ifr))
912                         return -EFAULT;
913                 return 0;
914
915         case SIOCSIFHWADDR:
916                 /* Set hw address */
917                 DBG(KERN_DEBUG "%s: set hw address: %s\n",
918                         tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data));
919
920                 rtnl_lock();
921                 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
922                 rtnl_unlock();
923                 return ret;
924
925         default:
926                 return -EINVAL;
927         };
928
929         return 0;
930 }
931
932 static int tun_chr_fasync(int fd, struct file *file, int on)
933 {
934         struct tun_struct *tun = file->private_data;
935         int ret;
936
937         if (!tun)
938                 return -EBADFD;
939
940         DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
941
942         lock_kernel();
943         if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
944                 goto out;
945
946         if (on) {
947                 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
948                 if (ret)
949                         goto out;
950                 tun->flags |= TUN_FASYNC;
951         } else
952                 tun->flags &= ~TUN_FASYNC;
953         ret = 0;
954 out:
955         unlock_kernel();
956         return ret;
957 }
958
959 static int tun_chr_open(struct inode *inode, struct file * file)
960 {
961         cycle_kernel_lock();
962         DBG1(KERN_INFO "tunX: tun_chr_open\n");
963         file->private_data = NULL;
964         return 0;
965 }
966
967 static int tun_chr_close(struct inode *inode, struct file *file)
968 {
969         struct tun_struct *tun = file->private_data;
970
971         if (!tun)
972                 return 0;
973
974         DBG(KERN_INFO "%s: tun_chr_close\n", tun->dev->name);
975
976         tun_chr_fasync(-1, file, 0);
977
978         rtnl_lock();
979
980         /* Detach from net device */
981         file->private_data = NULL;
982         tun->attached = 0;
983         put_net(dev_net(tun->dev));
984
985         /* Drop read queue */
986         skb_queue_purge(&tun->readq);
987
988         if (!(tun->flags & TUN_PERSIST)) {
989                 list_del(&tun->list);
990                 unregister_netdevice(tun->dev);
991         }
992
993         rtnl_unlock();
994
995         return 0;
996 }
997
998 static const struct file_operations tun_fops = {
999         .owner  = THIS_MODULE,
1000         .llseek = no_llseek,
1001         .read  = do_sync_read,
1002         .aio_read  = tun_chr_aio_read,
1003         .write = do_sync_write,
1004         .aio_write = tun_chr_aio_write,
1005         .poll   = tun_chr_poll,
1006         .ioctl  = tun_chr_ioctl,
1007         .open   = tun_chr_open,
1008         .release = tun_chr_close,
1009         .fasync = tun_chr_fasync
1010 };
1011
1012 static struct miscdevice tun_miscdev = {
1013         .minor = TUN_MINOR,
1014         .name = "tun",
1015         .fops = &tun_fops,
1016 };
1017
1018 /* ethtool interface */
1019
1020 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1021 {
1022         cmd->supported          = 0;
1023         cmd->advertising        = 0;
1024         cmd->speed              = SPEED_10;
1025         cmd->duplex             = DUPLEX_FULL;
1026         cmd->port               = PORT_TP;
1027         cmd->phy_address        = 0;
1028         cmd->transceiver        = XCVR_INTERNAL;
1029         cmd->autoneg            = AUTONEG_DISABLE;
1030         cmd->maxtxpkt           = 0;
1031         cmd->maxrxpkt           = 0;
1032         return 0;
1033 }
1034
1035 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
1036 {
1037         struct tun_struct *tun = netdev_priv(dev);
1038
1039         strcpy(info->driver, DRV_NAME);
1040         strcpy(info->version, DRV_VERSION);
1041         strcpy(info->fw_version, "N/A");
1042
1043         switch (tun->flags & TUN_TYPE_MASK) {
1044         case TUN_TUN_DEV:
1045                 strcpy(info->bus_info, "tun");
1046                 break;
1047         case TUN_TAP_DEV:
1048                 strcpy(info->bus_info, "tap");
1049                 break;
1050         }
1051 }
1052
1053 static u32 tun_get_msglevel(struct net_device *dev)
1054 {
1055 #ifdef TUN_DEBUG
1056         struct tun_struct *tun = netdev_priv(dev);
1057         return tun->debug;
1058 #else
1059         return -EOPNOTSUPP;
1060 #endif
1061 }
1062
1063 static void tun_set_msglevel(struct net_device *dev, u32 value)
1064 {
1065 #ifdef TUN_DEBUG
1066         struct tun_struct *tun = netdev_priv(dev);
1067         tun->debug = value;
1068 #endif
1069 }
1070
1071 static u32 tun_get_link(struct net_device *dev)
1072 {
1073         struct tun_struct *tun = netdev_priv(dev);
1074         return tun->attached;
1075 }
1076
1077 static u32 tun_get_rx_csum(struct net_device *dev)
1078 {
1079         struct tun_struct *tun = netdev_priv(dev);
1080         return (tun->flags & TUN_NOCHECKSUM) == 0;
1081 }
1082
1083 static int tun_set_rx_csum(struct net_device *dev, u32 data)
1084 {
1085         struct tun_struct *tun = netdev_priv(dev);
1086         if (data)
1087                 tun->flags &= ~TUN_NOCHECKSUM;
1088         else
1089                 tun->flags |= TUN_NOCHECKSUM;
1090         return 0;
1091 }
1092
1093 static const struct ethtool_ops tun_ethtool_ops = {
1094         .get_settings   = tun_get_settings,
1095         .get_drvinfo    = tun_get_drvinfo,
1096         .get_msglevel   = tun_get_msglevel,
1097         .set_msglevel   = tun_set_msglevel,
1098         .get_link       = tun_get_link,
1099         .get_rx_csum    = tun_get_rx_csum,
1100         .set_rx_csum    = tun_set_rx_csum
1101 };
1102
1103 static int tun_init_net(struct net *net)
1104 {
1105         struct tun_net *tn;
1106
1107         tn = kmalloc(sizeof(*tn), GFP_KERNEL);
1108         if (tn == NULL)
1109                 return -ENOMEM;
1110
1111         INIT_LIST_HEAD(&tn->dev_list);
1112
1113         if (net_assign_generic(net, tun_net_id, tn)) {
1114                 kfree(tn);
1115                 return -ENOMEM;
1116         }
1117
1118         return 0;
1119 }
1120
1121 static void tun_exit_net(struct net *net)
1122 {
1123         struct tun_net *tn;
1124         struct tun_struct *tun, *nxt;
1125
1126         tn = net_generic(net, tun_net_id);
1127
1128         rtnl_lock();
1129         list_for_each_entry_safe(tun, nxt, &tn->dev_list, list) {
1130                 DBG(KERN_INFO "%s cleaned up\n", tun->dev->name);
1131                 unregister_netdevice(tun->dev);
1132         }
1133         rtnl_unlock();
1134
1135         kfree(tn);
1136 }
1137
1138 static struct pernet_operations tun_net_ops = {
1139         .init = tun_init_net,
1140         .exit = tun_exit_net,
1141 };
1142
1143 static int __init tun_init(void)
1144 {
1145         int ret = 0;
1146
1147         printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
1148         printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
1149
1150         ret = register_pernet_gen_device(&tun_net_id, &tun_net_ops);
1151         if (ret) {
1152                 printk(KERN_ERR "tun: Can't register pernet ops\n");
1153                 goto err_pernet;
1154         }
1155
1156         ret = misc_register(&tun_miscdev);
1157         if (ret) {
1158                 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
1159                 goto err_misc;
1160         }
1161         return 0;
1162
1163 err_misc:
1164         unregister_pernet_gen_device(tun_net_id, &tun_net_ops);
1165 err_pernet:
1166         return ret;
1167 }
1168
1169 static void tun_cleanup(void)
1170 {
1171         misc_deregister(&tun_miscdev);
1172         unregister_pernet_gen_device(tun_net_id, &tun_net_ops);
1173 }
1174
1175 module_init(tun_init);
1176 module_exit(tun_cleanup);
1177 MODULE_DESCRIPTION(DRV_DESCRIPTION);
1178 MODULE_AUTHOR(DRV_COPYRIGHT);
1179 MODULE_LICENSE("GPL");
1180 MODULE_ALIAS_MISCDEV(TUN_MINOR);