S2io: Check for device state before handling traffic
[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  *  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 <net/net_namespace.h>
66
67 #include <asm/system.h>
68 #include <asm/uaccess.h>
69
70 #ifdef TUN_DEBUG
71 static int debug;
72 #endif
73
74 /* Network device part of the driver */
75
76 static LIST_HEAD(tun_dev_list);
77 static const struct ethtool_ops tun_ethtool_ops;
78
79 /* Net device open. */
80 static int tun_net_open(struct net_device *dev)
81 {
82         netif_start_queue(dev);
83         return 0;
84 }
85
86 /* Net device close. */
87 static int tun_net_close(struct net_device *dev)
88 {
89         netif_stop_queue(dev);
90         return 0;
91 }
92
93 /* Net device start xmit */
94 static int tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
95 {
96         struct tun_struct *tun = netdev_priv(dev);
97
98         DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len);
99
100         /* Drop packet if interface is not attached */
101         if (!tun->attached)
102                 goto drop;
103
104         /* Packet dropping */
105         if (skb_queue_len(&tun->readq) >= dev->tx_queue_len) {
106                 if (!(tun->flags & TUN_ONE_QUEUE)) {
107                         /* Normal queueing mode. */
108                         /* Packet scheduler handles dropping of further packets. */
109                         netif_stop_queue(dev);
110
111                         /* We won't see all dropped packets individually, so overrun
112                          * error is more appropriate. */
113                         tun->stats.tx_fifo_errors++;
114                 } else {
115                         /* Single queue mode.
116                          * Driver handles dropping of all packets itself. */
117                         goto drop;
118                 }
119         }
120
121         /* Queue packet */
122         skb_queue_tail(&tun->readq, skb);
123         dev->trans_start = jiffies;
124
125         /* Notify and wake up reader process */
126         if (tun->flags & TUN_FASYNC)
127                 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
128         wake_up_interruptible(&tun->read_wait);
129         return 0;
130
131 drop:
132         tun->stats.tx_dropped++;
133         kfree_skb(skb);
134         return 0;
135 }
136
137 /** Add the specified Ethernet address to this multicast filter. */
138 static void
139 add_multi(u32* filter, const u8* addr)
140 {
141         int bit_nr = ether_crc(ETH_ALEN, addr) >> 26;
142         filter[bit_nr >> 5] |= 1 << (bit_nr & 31);
143 }
144
145 /** Remove the specified Ethernet addres from this multicast filter. */
146 static void
147 del_multi(u32* filter, const u8* addr)
148 {
149         int bit_nr = ether_crc(ETH_ALEN, addr) >> 26;
150         filter[bit_nr >> 5] &= ~(1 << (bit_nr & 31));
151 }
152
153 /** Update the list of multicast groups to which the network device belongs.
154  * This list is used to filter packets being sent from the character device to
155  * the network device. */
156 static void
157 tun_net_mclist(struct net_device *dev)
158 {
159         struct tun_struct *tun = netdev_priv(dev);
160         const struct dev_mc_list *mclist;
161         int i;
162         DBG(KERN_DEBUG "%s: tun_net_mclist: mc_count %d\n",
163                         dev->name, dev->mc_count);
164         memset(tun->chr_filter, 0, sizeof tun->chr_filter);
165         for (i = 0, mclist = dev->mc_list; i < dev->mc_count && mclist != NULL;
166                         i++, mclist = mclist->next) {
167                 add_multi(tun->net_filter, mclist->dmi_addr);
168                 DBG(KERN_DEBUG "%s: tun_net_mclist: %x:%x:%x:%x:%x:%x\n",
169                                 dev->name,
170                                 mclist->dmi_addr[0], mclist->dmi_addr[1], mclist->dmi_addr[2],
171                                 mclist->dmi_addr[3], mclist->dmi_addr[4], mclist->dmi_addr[5]);
172         }
173 }
174
175 static struct net_device_stats *tun_net_stats(struct net_device *dev)
176 {
177         struct tun_struct *tun = netdev_priv(dev);
178         return &tun->stats;
179 }
180
181 /* Initialize net device. */
182 static void tun_net_init(struct net_device *dev)
183 {
184         struct tun_struct *tun = netdev_priv(dev);
185
186         switch (tun->flags & TUN_TYPE_MASK) {
187         case TUN_TUN_DEV:
188                 /* Point-to-Point TUN Device */
189                 dev->hard_header_len = 0;
190                 dev->addr_len = 0;
191                 dev->mtu = 1500;
192
193                 /* Zero header length */
194                 dev->type = ARPHRD_NONE;
195                 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
196                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
197                 break;
198
199         case TUN_TAP_DEV:
200                 /* Ethernet TAP Device */
201                 dev->set_multicast_list = tun_net_mclist;
202
203                 ether_setup(dev);
204
205                 /* random address already created for us by tun_set_iff, use it */
206                 memcpy(dev->dev_addr, tun->dev_addr, min(sizeof(tun->dev_addr), sizeof(dev->dev_addr)) );
207
208                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
209                 break;
210         }
211 }
212
213 /* Character device part */
214
215 /* Poll */
216 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
217 {
218         struct tun_struct *tun = file->private_data;
219         unsigned int mask = POLLOUT | POLLWRNORM;
220
221         if (!tun)
222                 return -EBADFD;
223
224         DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
225
226         poll_wait(file, &tun->read_wait, wait);
227
228         if (!skb_queue_empty(&tun->readq))
229                 mask |= POLLIN | POLLRDNORM;
230
231         return mask;
232 }
233
234 /* Get packet from user space buffer */
235 static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, size_t count)
236 {
237         struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) };
238         struct sk_buff *skb;
239         size_t len = count, align = 0;
240
241         if (!(tun->flags & TUN_NO_PI)) {
242                 if ((len -= sizeof(pi)) > count)
243                         return -EINVAL;
244
245                 if(memcpy_fromiovec((void *)&pi, iv, sizeof(pi)))
246                         return -EFAULT;
247         }
248
249         if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV)
250                 align = NET_IP_ALIGN;
251
252         if (!(skb = alloc_skb(len + align, GFP_KERNEL))) {
253                 tun->stats.rx_dropped++;
254                 return -ENOMEM;
255         }
256
257         if (align)
258                 skb_reserve(skb, align);
259         if (memcpy_fromiovec(skb_put(skb, len), iv, len)) {
260                 tun->stats.rx_dropped++;
261                 kfree_skb(skb);
262                 return -EFAULT;
263         }
264
265         switch (tun->flags & TUN_TYPE_MASK) {
266         case TUN_TUN_DEV:
267                 skb_reset_mac_header(skb);
268                 skb->protocol = pi.proto;
269                 skb->dev = tun->dev;
270                 break;
271         case TUN_TAP_DEV:
272                 skb->protocol = eth_type_trans(skb, tun->dev);
273                 break;
274         };
275
276         if (tun->flags & TUN_NOCHECKSUM)
277                 skb->ip_summed = CHECKSUM_UNNECESSARY;
278
279         netif_rx_ni(skb);
280         tun->dev->last_rx = jiffies;
281
282         tun->stats.rx_packets++;
283         tun->stats.rx_bytes += len;
284
285         return count;
286 }
287
288 static inline size_t iov_total(const struct iovec *iv, unsigned long count)
289 {
290         unsigned long i;
291         size_t len;
292
293         for (i = 0, len = 0; i < count; i++)
294                 len += iv[i].iov_len;
295
296         return len;
297 }
298
299 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
300                               unsigned long count, loff_t pos)
301 {
302         struct tun_struct *tun = iocb->ki_filp->private_data;
303
304         if (!tun)
305                 return -EBADFD;
306
307         DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
308
309         return tun_get_user(tun, (struct iovec *) iv, iov_total(iv, count));
310 }
311
312 /* Put packet to the user space buffer */
313 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
314                                        struct sk_buff *skb,
315                                        struct iovec *iv, int len)
316 {
317         struct tun_pi pi = { 0, skb->protocol };
318         ssize_t total = 0;
319
320         if (!(tun->flags & TUN_NO_PI)) {
321                 if ((len -= sizeof(pi)) < 0)
322                         return -EINVAL;
323
324                 if (len < skb->len) {
325                         /* Packet will be striped */
326                         pi.flags |= TUN_PKT_STRIP;
327                 }
328
329                 if (memcpy_toiovec(iv, (void *) &pi, sizeof(pi)))
330                         return -EFAULT;
331                 total += sizeof(pi);
332         }
333
334         len = min_t(int, skb->len, len);
335
336         skb_copy_datagram_iovec(skb, 0, iv, len);
337         total += len;
338
339         tun->stats.tx_packets++;
340         tun->stats.tx_bytes += len;
341
342         return total;
343 }
344
345 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
346                             unsigned long count, loff_t pos)
347 {
348         struct file *file = iocb->ki_filp;
349         struct tun_struct *tun = file->private_data;
350         DECLARE_WAITQUEUE(wait, current);
351         struct sk_buff *skb;
352         ssize_t len, ret = 0;
353
354         if (!tun)
355                 return -EBADFD;
356
357         DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
358
359         len = iov_total(iv, count);
360         if (len < 0)
361                 return -EINVAL;
362
363         add_wait_queue(&tun->read_wait, &wait);
364         while (len) {
365                 const u8 ones[ ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
366                 u8 addr[ ETH_ALEN];
367                 int bit_nr;
368
369                 current->state = TASK_INTERRUPTIBLE;
370
371                 /* Read frames from the queue */
372                 if (!(skb=skb_dequeue(&tun->readq))) {
373                         if (file->f_flags & O_NONBLOCK) {
374                                 ret = -EAGAIN;
375                                 break;
376                         }
377                         if (signal_pending(current)) {
378                                 ret = -ERESTARTSYS;
379                                 break;
380                         }
381
382                         /* Nothing to read, let's sleep */
383                         schedule();
384                         continue;
385                 }
386                 netif_wake_queue(tun->dev);
387
388                 /** Decide whether to accept this packet. This code is designed to
389                  * behave identically to an Ethernet interface. Accept the packet if
390                  * - we are promiscuous.
391                  * - the packet is addressed to us.
392                  * - the packet is broadcast.
393                  * - the packet is multicast and
394                  *   - we are multicast promiscous.
395                  *   - we belong to the multicast group.
396                  */
397                 skb_copy_from_linear_data(skb, addr, min_t(size_t, sizeof addr,
398                                                                    skb->len));
399                 bit_nr = ether_crc(sizeof addr, addr) >> 26;
400                 if ((tun->if_flags & IFF_PROMISC) ||
401                                 memcmp(addr, tun->dev_addr, sizeof addr) == 0 ||
402                                 memcmp(addr, ones, sizeof addr) == 0 ||
403                                 (((addr[0] == 1 && addr[1] == 0 && addr[2] == 0x5e) ||
404                                   (addr[0] == 0x33 && addr[1] == 0x33)) &&
405                                  ((tun->if_flags & IFF_ALLMULTI) ||
406                                   (tun->chr_filter[bit_nr >> 5] & (1 << (bit_nr & 31)))))) {
407                         DBG(KERN_DEBUG "%s: tun_chr_readv: accepted: %x:%x:%x:%x:%x:%x\n",
408                                         tun->dev->name, addr[0], addr[1], addr[2],
409                                         addr[3], addr[4], addr[5]);
410                         ret = tun_put_user(tun, skb, (struct iovec *) iv, len);
411                         kfree_skb(skb);
412                         break;
413                 } else {
414                         DBG(KERN_DEBUG "%s: tun_chr_readv: rejected: %x:%x:%x:%x:%x:%x\n",
415                                         tun->dev->name, addr[0], addr[1], addr[2],
416                                         addr[3], addr[4], addr[5]);
417                         kfree_skb(skb);
418                         continue;
419                 }
420         }
421
422         current->state = TASK_RUNNING;
423         remove_wait_queue(&tun->read_wait, &wait);
424
425         return ret;
426 }
427
428 static void tun_setup(struct net_device *dev)
429 {
430         struct tun_struct *tun = netdev_priv(dev);
431
432         skb_queue_head_init(&tun->readq);
433         init_waitqueue_head(&tun->read_wait);
434
435         tun->owner = -1;
436         tun->group = -1;
437
438         SET_MODULE_OWNER(dev);
439         dev->open = tun_net_open;
440         dev->hard_start_xmit = tun_net_xmit;
441         dev->stop = tun_net_close;
442         dev->get_stats = tun_net_stats;
443         dev->ethtool_ops = &tun_ethtool_ops;
444         dev->destructor = free_netdev;
445 }
446
447 static struct tun_struct *tun_get_by_name(const char *name)
448 {
449         struct tun_struct *tun;
450
451         ASSERT_RTNL();
452         list_for_each_entry(tun, &tun_dev_list, list) {
453                 if (!strncmp(tun->dev->name, name, IFNAMSIZ))
454                     return tun;
455         }
456
457         return NULL;
458 }
459
460 static int tun_set_iff(struct file *file, struct ifreq *ifr)
461 {
462         struct tun_struct *tun;
463         struct net_device *dev;
464         int err;
465
466         tun = tun_get_by_name(ifr->ifr_name);
467         if (tun) {
468                 if (tun->attached)
469                         return -EBUSY;
470
471                 /* Check permissions */
472                 if (((tun->owner != -1 &&
473                       current->euid != tun->owner) ||
474                      (tun->group != -1 &&
475                       current->egid != tun->group)) &&
476                      !capable(CAP_NET_ADMIN))
477                         return -EPERM;
478         }
479         else if (__dev_get_by_name(&init_net, ifr->ifr_name))
480                 return -EINVAL;
481         else {
482                 char *name;
483                 unsigned long flags = 0;
484
485                 err = -EINVAL;
486
487                 if (!capable(CAP_NET_ADMIN))
488                         return -EPERM;
489
490                 /* Set dev type */
491                 if (ifr->ifr_flags & IFF_TUN) {
492                         /* TUN device */
493                         flags |= TUN_TUN_DEV;
494                         name = "tun%d";
495                 } else if (ifr->ifr_flags & IFF_TAP) {
496                         /* TAP device */
497                         flags |= TUN_TAP_DEV;
498                         name = "tap%d";
499                 } else
500                         goto failed;
501
502                 if (*ifr->ifr_name)
503                         name = ifr->ifr_name;
504
505                 dev = alloc_netdev(sizeof(struct tun_struct), name,
506                                    tun_setup);
507                 if (!dev)
508                         return -ENOMEM;
509
510                 tun = netdev_priv(dev);
511                 tun->dev = dev;
512                 tun->flags = flags;
513                 /* Be promiscuous by default to maintain previous behaviour. */
514                 tun->if_flags = IFF_PROMISC;
515                 /* Generate random Ethernet address. */
516                 *(u16 *)tun->dev_addr = htons(0x00FF);
517                 get_random_bytes(tun->dev_addr + sizeof(u16), 4);
518                 memset(tun->chr_filter, 0, sizeof tun->chr_filter);
519
520                 tun_net_init(dev);
521
522                 if (strchr(dev->name, '%')) {
523                         err = dev_alloc_name(dev, dev->name);
524                         if (err < 0)
525                                 goto err_free_dev;
526                 }
527
528                 err = register_netdevice(tun->dev);
529                 if (err < 0)
530                         goto err_free_dev;
531
532                 list_add(&tun->list, &tun_dev_list);
533         }
534
535         DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
536
537         if (ifr->ifr_flags & IFF_NO_PI)
538                 tun->flags |= TUN_NO_PI;
539
540         if (ifr->ifr_flags & IFF_ONE_QUEUE)
541                 tun->flags |= TUN_ONE_QUEUE;
542
543         file->private_data = tun;
544         tun->attached = 1;
545
546         strcpy(ifr->ifr_name, tun->dev->name);
547         return 0;
548
549  err_free_dev:
550         free_netdev(dev);
551  failed:
552         return err;
553 }
554
555 static int tun_chr_ioctl(struct inode *inode, struct file *file,
556                          unsigned int cmd, unsigned long arg)
557 {
558         struct tun_struct *tun = file->private_data;
559         void __user* argp = (void __user*)arg;
560         struct ifreq ifr;
561
562         if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
563                 if (copy_from_user(&ifr, argp, sizeof ifr))
564                         return -EFAULT;
565
566         if (cmd == TUNSETIFF && !tun) {
567                 int err;
568
569                 ifr.ifr_name[IFNAMSIZ-1] = '\0';
570
571                 rtnl_lock();
572                 err = tun_set_iff(file, &ifr);
573                 rtnl_unlock();
574
575                 if (err)
576                         return err;
577
578                 if (copy_to_user(argp, &ifr, sizeof(ifr)))
579                         return -EFAULT;
580                 return 0;
581         }
582
583         if (!tun)
584                 return -EBADFD;
585
586         DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
587
588         switch (cmd) {
589         case TUNSETNOCSUM:
590                 /* Disable/Enable checksum */
591                 if (arg)
592                         tun->flags |= TUN_NOCHECKSUM;
593                 else
594                         tun->flags &= ~TUN_NOCHECKSUM;
595
596                 DBG(KERN_INFO "%s: checksum %s\n",
597                     tun->dev->name, arg ? "disabled" : "enabled");
598                 break;
599
600         case TUNSETPERSIST:
601                 /* Disable/Enable persist mode */
602                 if (arg)
603                         tun->flags |= TUN_PERSIST;
604                 else
605                         tun->flags &= ~TUN_PERSIST;
606
607                 DBG(KERN_INFO "%s: persist %s\n",
608                     tun->dev->name, arg ? "disabled" : "enabled");
609                 break;
610
611         case TUNSETOWNER:
612                 /* Set owner of the device */
613                 tun->owner = (uid_t) arg;
614
615                 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
616                 break;
617
618         case TUNSETGROUP:
619                 /* Set group of the device */
620                 tun->group= (gid_t) arg;
621
622                 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group);
623                 break;
624
625         case TUNSETLINK:
626                 /* Only allow setting the type when the interface is down */
627                 if (tun->dev->flags & IFF_UP) {
628                         DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
629                                 tun->dev->name);
630                         return -EBUSY;
631                 } else {
632                         tun->dev->type = (int) arg;
633                         DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
634                 }
635                 break;
636
637 #ifdef TUN_DEBUG
638         case TUNSETDEBUG:
639                 tun->debug = arg;
640                 break;
641 #endif
642
643         case SIOCGIFFLAGS:
644                 ifr.ifr_flags = tun->if_flags;
645                 if (copy_to_user( argp, &ifr, sizeof ifr))
646                         return -EFAULT;
647                 return 0;
648
649         case SIOCSIFFLAGS:
650                 /** Set the character device's interface flags. Currently only
651                  * IFF_PROMISC and IFF_ALLMULTI are used. */
652                 tun->if_flags = ifr.ifr_flags;
653                 DBG(KERN_INFO "%s: interface flags 0x%lx\n",
654                                 tun->dev->name, tun->if_flags);
655                 return 0;
656
657         case SIOCGIFHWADDR:
658                 /* Note: the actual net device's address may be different */
659                 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev_addr,
660                                 min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
661                 if (copy_to_user( argp, &ifr, sizeof ifr))
662                         return -EFAULT;
663                 return 0;
664
665         case SIOCSIFHWADDR:
666         {
667                 /* try to set the actual net device's hw address */
668                 int ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
669
670                 if (ret == 0) {
671                         /** Set the character device's hardware address. This is used when
672                          * filtering packets being sent from the network device to the character
673                          * device. */
674                         memcpy(tun->dev_addr, ifr.ifr_hwaddr.sa_data,
675                                         min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
676                         DBG(KERN_DEBUG "%s: set hardware address: %x:%x:%x:%x:%x:%x\n",
677                                         tun->dev->name,
678                                         tun->dev_addr[0], tun->dev_addr[1], tun->dev_addr[2],
679                                         tun->dev_addr[3], tun->dev_addr[4], tun->dev_addr[5]);
680                 }
681
682                 return  ret;
683         }
684
685         case SIOCADDMULTI:
686                 /** Add the specified group to the character device's multicast filter
687                  * list. */
688                 add_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
689                 DBG(KERN_DEBUG "%s: add multi: %x:%x:%x:%x:%x:%x\n",
690                                 tun->dev->name,
691                                 (u8)ifr.ifr_hwaddr.sa_data[0], (u8)ifr.ifr_hwaddr.sa_data[1],
692                                 (u8)ifr.ifr_hwaddr.sa_data[2], (u8)ifr.ifr_hwaddr.sa_data[3],
693                                 (u8)ifr.ifr_hwaddr.sa_data[4], (u8)ifr.ifr_hwaddr.sa_data[5]);
694                 return 0;
695
696         case SIOCDELMULTI:
697                 /** Remove the specified group from the character device's multicast
698                  * filter list. */
699                 del_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
700                 DBG(KERN_DEBUG "%s: del multi: %x:%x:%x:%x:%x:%x\n",
701                                 tun->dev->name,
702                                 (u8)ifr.ifr_hwaddr.sa_data[0], (u8)ifr.ifr_hwaddr.sa_data[1],
703                                 (u8)ifr.ifr_hwaddr.sa_data[2], (u8)ifr.ifr_hwaddr.sa_data[3],
704                                 (u8)ifr.ifr_hwaddr.sa_data[4], (u8)ifr.ifr_hwaddr.sa_data[5]);
705                 return 0;
706
707         default:
708                 return -EINVAL;
709         };
710
711         return 0;
712 }
713
714 static int tun_chr_fasync(int fd, struct file *file, int on)
715 {
716         struct tun_struct *tun = file->private_data;
717         int ret;
718
719         if (!tun)
720                 return -EBADFD;
721
722         DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
723
724         if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
725                 return ret;
726
727         if (on) {
728                 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
729                 if (ret)
730                         return ret;
731                 tun->flags |= TUN_FASYNC;
732         } else
733                 tun->flags &= ~TUN_FASYNC;
734
735         return 0;
736 }
737
738 static int tun_chr_open(struct inode *inode, struct file * file)
739 {
740         DBG1(KERN_INFO "tunX: tun_chr_open\n");
741         file->private_data = NULL;
742         return 0;
743 }
744
745 static int tun_chr_close(struct inode *inode, struct file *file)
746 {
747         struct tun_struct *tun = file->private_data;
748
749         if (!tun)
750                 return 0;
751
752         DBG(KERN_INFO "%s: tun_chr_close\n", tun->dev->name);
753
754         tun_chr_fasync(-1, file, 0);
755
756         rtnl_lock();
757
758         /* Detach from net device */
759         file->private_data = NULL;
760         tun->attached = 0;
761
762         /* Drop read queue */
763         skb_queue_purge(&tun->readq);
764
765         if (!(tun->flags & TUN_PERSIST)) {
766                 list_del(&tun->list);
767                 unregister_netdevice(tun->dev);
768         }
769
770         rtnl_unlock();
771
772         return 0;
773 }
774
775 static const struct file_operations tun_fops = {
776         .owner  = THIS_MODULE,
777         .llseek = no_llseek,
778         .read  = do_sync_read,
779         .aio_read  = tun_chr_aio_read,
780         .write = do_sync_write,
781         .aio_write = tun_chr_aio_write,
782         .poll   = tun_chr_poll,
783         .ioctl  = tun_chr_ioctl,
784         .open   = tun_chr_open,
785         .release = tun_chr_close,
786         .fasync = tun_chr_fasync
787 };
788
789 static struct miscdevice tun_miscdev = {
790         .minor = TUN_MINOR,
791         .name = "tun",
792         .fops = &tun_fops,
793 };
794
795 /* ethtool interface */
796
797 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
798 {
799         cmd->supported          = 0;
800         cmd->advertising        = 0;
801         cmd->speed              = SPEED_10;
802         cmd->duplex             = DUPLEX_FULL;
803         cmd->port               = PORT_TP;
804         cmd->phy_address        = 0;
805         cmd->transceiver        = XCVR_INTERNAL;
806         cmd->autoneg            = AUTONEG_DISABLE;
807         cmd->maxtxpkt           = 0;
808         cmd->maxrxpkt           = 0;
809         return 0;
810 }
811
812 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
813 {
814         struct tun_struct *tun = netdev_priv(dev);
815
816         strcpy(info->driver, DRV_NAME);
817         strcpy(info->version, DRV_VERSION);
818         strcpy(info->fw_version, "N/A");
819
820         switch (tun->flags & TUN_TYPE_MASK) {
821         case TUN_TUN_DEV:
822                 strcpy(info->bus_info, "tun");
823                 break;
824         case TUN_TAP_DEV:
825                 strcpy(info->bus_info, "tap");
826                 break;
827         }
828 }
829
830 static u32 tun_get_msglevel(struct net_device *dev)
831 {
832 #ifdef TUN_DEBUG
833         struct tun_struct *tun = netdev_priv(dev);
834         return tun->debug;
835 #else
836         return -EOPNOTSUPP;
837 #endif
838 }
839
840 static void tun_set_msglevel(struct net_device *dev, u32 value)
841 {
842 #ifdef TUN_DEBUG
843         struct tun_struct *tun = netdev_priv(dev);
844         tun->debug = value;
845 #endif
846 }
847
848 static u32 tun_get_link(struct net_device *dev)
849 {
850         struct tun_struct *tun = netdev_priv(dev);
851         return tun->attached;
852 }
853
854 static u32 tun_get_rx_csum(struct net_device *dev)
855 {
856         struct tun_struct *tun = netdev_priv(dev);
857         return (tun->flags & TUN_NOCHECKSUM) == 0;
858 }
859
860 static int tun_set_rx_csum(struct net_device *dev, u32 data)
861 {
862         struct tun_struct *tun = netdev_priv(dev);
863         if (data)
864                 tun->flags &= ~TUN_NOCHECKSUM;
865         else
866                 tun->flags |= TUN_NOCHECKSUM;
867         return 0;
868 }
869
870 static const struct ethtool_ops tun_ethtool_ops = {
871         .get_settings   = tun_get_settings,
872         .get_drvinfo    = tun_get_drvinfo,
873         .get_msglevel   = tun_get_msglevel,
874         .set_msglevel   = tun_set_msglevel,
875         .get_link       = tun_get_link,
876         .get_rx_csum    = tun_get_rx_csum,
877         .set_rx_csum    = tun_set_rx_csum
878 };
879
880 static int __init tun_init(void)
881 {
882         int ret = 0;
883
884         printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
885         printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
886
887         ret = misc_register(&tun_miscdev);
888         if (ret)
889                 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
890         return ret;
891 }
892
893 static void tun_cleanup(void)
894 {
895         struct tun_struct *tun, *nxt;
896
897         misc_deregister(&tun_miscdev);
898
899         rtnl_lock();
900         list_for_each_entry_safe(tun, nxt, &tun_dev_list, list) {
901                 DBG(KERN_INFO "%s cleaned up\n", tun->dev->name);
902                 unregister_netdevice(tun->dev);
903         }
904         rtnl_unlock();
905
906 }
907
908 module_init(tun_init);
909 module_exit(tun_cleanup);
910 MODULE_DESCRIPTION(DRV_DESCRIPTION);
911 MODULE_AUTHOR(DRV_COPYRIGHT);
912 MODULE_LICENSE("GPL");
913 MODULE_ALIAS_MISCDEV(TUN_MINOR);