Add support the Korina (IDT RC32434) Ethernet MAC
[linux-2.6.git] / drivers / net / tun.c
1 /*
2  *  TUN - Universal TUN/TAP device driver.
3  *  Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com>
4  *
5  *  This program is free software; you can redistribute it and/or modify
6  *  it under the terms of the GNU General Public License as published by
7  *  the Free Software Foundation; either version 2 of the License, or
8  *  (at your option) any later version.
9  *
10  *  This program is distributed in the hope that it will be useful,
11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13  *  GNU General Public License for more details.
14  *
15  *  $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $
16  */
17
18 /*
19  *  Changes:
20  *
21  *  Brian Braunstein <linuxkernel@bristyle.com> 2007/03/23
22  *    Fixed hw address handling.  Now net_device.dev_addr is kept consistent
23  *    with tun.dev_addr when the address is set by this module.
24  *
25  *  Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
26  *    Add TUNSETLINK ioctl to set the link encapsulation
27  *
28  *  Mark Smith <markzzzsmith@yahoo.com.au>
29  *   Use random_ether_addr() for tap MAC address.
30  *
31  *  Harald Roelle <harald.roelle@ifi.lmu.de>  2004/04/20
32  *    Fixes in packet dropping, queue length setting and queue wakeup.
33  *    Increased default tx queue length.
34  *    Added ethtool API.
35  *    Minor cleanups
36  *
37  *  Daniel Podlejski <underley@underley.eu.org>
38  *    Modifications for 2.3.99-pre5 kernel.
39  */
40
41 #define DRV_NAME        "tun"
42 #define DRV_VERSION     "1.6"
43 #define DRV_DESCRIPTION "Universal TUN/TAP device driver"
44 #define DRV_COPYRIGHT   "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>"
45
46 #include <linux/module.h>
47 #include <linux/errno.h>
48 #include <linux/kernel.h>
49 #include <linux/major.h>
50 #include <linux/slab.h>
51 #include <linux/poll.h>
52 #include <linux/fcntl.h>
53 #include <linux/init.h>
54 #include <linux/skbuff.h>
55 #include <linux/netdevice.h>
56 #include <linux/etherdevice.h>
57 #include <linux/miscdevice.h>
58 #include <linux/ethtool.h>
59 #include <linux/rtnetlink.h>
60 #include <linux/if.h>
61 #include <linux/if_arp.h>
62 #include <linux/if_ether.h>
63 #include <linux/if_tun.h>
64 #include <linux/crc32.h>
65 #include <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                         dev->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         dev->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         DECLARE_MAC_BUF(mac);
163         DBG(KERN_DEBUG "%s: tun_net_mclist: mc_count %d\n",
164                         dev->name, dev->mc_count);
165         memset(tun->chr_filter, 0, sizeof tun->chr_filter);
166         for (i = 0, mclist = dev->mc_list; i < dev->mc_count && mclist != NULL;
167                         i++, mclist = mclist->next) {
168                 add_multi(tun->net_filter, mclist->dmi_addr);
169                 DBG(KERN_DEBUG "%s: tun_net_mclist: %s\n",
170                     dev->name, print_mac(mac, mclist->dmi_addr));
171         }
172 }
173
174 #define MIN_MTU 68
175 #define MAX_MTU 65535
176
177 static int
178 tun_net_change_mtu(struct net_device *dev, int new_mtu)
179 {
180         if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
181                 return -EINVAL;
182         dev->mtu = new_mtu;
183         return 0;
184 }
185
186 /* Initialize net device. */
187 static void tun_net_init(struct net_device *dev)
188 {
189         struct tun_struct *tun = netdev_priv(dev);
190
191         switch (tun->flags & TUN_TYPE_MASK) {
192         case TUN_TUN_DEV:
193                 /* Point-to-Point TUN Device */
194                 dev->hard_header_len = 0;
195                 dev->addr_len = 0;
196                 dev->mtu = 1500;
197                 dev->change_mtu = tun_net_change_mtu;
198
199                 /* Zero header length */
200                 dev->type = ARPHRD_NONE;
201                 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
202                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
203                 break;
204
205         case TUN_TAP_DEV:
206                 /* Ethernet TAP Device */
207                 dev->set_multicast_list = tun_net_mclist;
208
209                 ether_setup(dev);
210                 dev->change_mtu = tun_net_change_mtu;
211
212                 /* random address already created for us by tun_set_iff, use it */
213                 memcpy(dev->dev_addr, tun->dev_addr, min(sizeof(tun->dev_addr), sizeof(dev->dev_addr)) );
214
215                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
216                 break;
217         }
218 }
219
220 /* Character device part */
221
222 /* Poll */
223 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
224 {
225         struct tun_struct *tun = file->private_data;
226         unsigned int mask = POLLOUT | POLLWRNORM;
227
228         if (!tun)
229                 return -EBADFD;
230
231         DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
232
233         poll_wait(file, &tun->read_wait, wait);
234
235         if (!skb_queue_empty(&tun->readq))
236                 mask |= POLLIN | POLLRDNORM;
237
238         return mask;
239 }
240
241 /* Get packet from user space buffer */
242 static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, size_t count)
243 {
244         struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) };
245         struct sk_buff *skb;
246         size_t len = count, align = 0;
247
248         if (!(tun->flags & TUN_NO_PI)) {
249                 if ((len -= sizeof(pi)) > count)
250                         return -EINVAL;
251
252                 if(memcpy_fromiovec((void *)&pi, iv, sizeof(pi)))
253                         return -EFAULT;
254         }
255
256         if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV)
257                 align = NET_IP_ALIGN;
258
259         if (!(skb = alloc_skb(len + align, GFP_KERNEL))) {
260                 tun->dev->stats.rx_dropped++;
261                 return -ENOMEM;
262         }
263
264         if (align)
265                 skb_reserve(skb, align);
266         if (memcpy_fromiovec(skb_put(skb, len), iv, len)) {
267                 tun->dev->stats.rx_dropped++;
268                 kfree_skb(skb);
269                 return -EFAULT;
270         }
271
272         switch (tun->flags & TUN_TYPE_MASK) {
273         case TUN_TUN_DEV:
274                 skb_reset_mac_header(skb);
275                 skb->protocol = pi.proto;
276                 skb->dev = tun->dev;
277                 break;
278         case TUN_TAP_DEV:
279                 skb->protocol = eth_type_trans(skb, tun->dev);
280                 break;
281         };
282
283         if (tun->flags & TUN_NOCHECKSUM)
284                 skb->ip_summed = CHECKSUM_UNNECESSARY;
285
286         netif_rx_ni(skb);
287         tun->dev->last_rx = jiffies;
288
289         tun->dev->stats.rx_packets++;
290         tun->dev->stats.rx_bytes += len;
291
292         return count;
293 }
294
295 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
296                               unsigned long count, loff_t pos)
297 {
298         struct tun_struct *tun = iocb->ki_filp->private_data;
299
300         if (!tun)
301                 return -EBADFD;
302
303         DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
304
305         return tun_get_user(tun, (struct iovec *) iv, iov_length(iv, count));
306 }
307
308 /* Put packet to the user space buffer */
309 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
310                                        struct sk_buff *skb,
311                                        struct iovec *iv, int len)
312 {
313         struct tun_pi pi = { 0, skb->protocol };
314         ssize_t total = 0;
315
316         if (!(tun->flags & TUN_NO_PI)) {
317                 if ((len -= sizeof(pi)) < 0)
318                         return -EINVAL;
319
320                 if (len < skb->len) {
321                         /* Packet will be striped */
322                         pi.flags |= TUN_PKT_STRIP;
323                 }
324
325                 if (memcpy_toiovec(iv, (void *) &pi, sizeof(pi)))
326                         return -EFAULT;
327                 total += sizeof(pi);
328         }
329
330         len = min_t(int, skb->len, len);
331
332         skb_copy_datagram_iovec(skb, 0, iv, len);
333         total += len;
334
335         tun->dev->stats.tx_packets++;
336         tun->dev->stats.tx_bytes += len;
337
338         return total;
339 }
340
341 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
342                             unsigned long count, loff_t pos)
343 {
344         struct file *file = iocb->ki_filp;
345         struct tun_struct *tun = file->private_data;
346         DECLARE_WAITQUEUE(wait, current);
347         struct sk_buff *skb;
348         ssize_t len, ret = 0;
349         DECLARE_MAC_BUF(mac);
350
351         if (!tun)
352                 return -EBADFD;
353
354         DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
355
356         len = iov_length(iv, count);
357         if (len < 0)
358                 return -EINVAL;
359
360         add_wait_queue(&tun->read_wait, &wait);
361         while (len) {
362                 const u8 ones[ ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
363                 u8 addr[ ETH_ALEN];
364                 int bit_nr;
365
366                 current->state = TASK_INTERRUPTIBLE;
367
368                 /* Read frames from the queue */
369                 if (!(skb=skb_dequeue(&tun->readq))) {
370                         if (file->f_flags & O_NONBLOCK) {
371                                 ret = -EAGAIN;
372                                 break;
373                         }
374                         if (signal_pending(current)) {
375                                 ret = -ERESTARTSYS;
376                                 break;
377                         }
378
379                         /* Nothing to read, let's sleep */
380                         schedule();
381                         continue;
382                 }
383                 netif_wake_queue(tun->dev);
384
385                 /** Decide whether to accept this packet. This code is designed to
386                  * behave identically to an Ethernet interface. Accept the packet if
387                  * - we are promiscuous.
388                  * - the packet is addressed to us.
389                  * - the packet is broadcast.
390                  * - the packet is multicast and
391                  *   - we are multicast promiscous.
392                  *   - we belong to the multicast group.
393                  */
394                 skb_copy_from_linear_data(skb, addr, min_t(size_t, sizeof addr,
395                                                                    skb->len));
396                 bit_nr = ether_crc(sizeof addr, addr) >> 26;
397                 if ((tun->if_flags & IFF_PROMISC) ||
398                                 memcmp(addr, tun->dev_addr, sizeof addr) == 0 ||
399                                 memcmp(addr, ones, sizeof addr) == 0 ||
400                                 (((addr[0] == 1 && addr[1] == 0 && addr[2] == 0x5e) ||
401                                   (addr[0] == 0x33 && addr[1] == 0x33)) &&
402                                  ((tun->if_flags & IFF_ALLMULTI) ||
403                                   (tun->chr_filter[bit_nr >> 5] & (1 << (bit_nr & 31)))))) {
404                         DBG(KERN_DEBUG "%s: tun_chr_readv: accepted: %s\n",
405                                         tun->dev->name, print_mac(mac, addr));
406                         ret = tun_put_user(tun, skb, (struct iovec *) iv, len);
407                         kfree_skb(skb);
408                         break;
409                 } else {
410                         DBG(KERN_DEBUG "%s: tun_chr_readv: rejected: %s\n",
411                                         tun->dev->name, print_mac(mac, addr));
412                         kfree_skb(skb);
413                         continue;
414                 }
415         }
416
417         current->state = TASK_RUNNING;
418         remove_wait_queue(&tun->read_wait, &wait);
419
420         return ret;
421 }
422
423 static void tun_setup(struct net_device *dev)
424 {
425         struct tun_struct *tun = netdev_priv(dev);
426
427         skb_queue_head_init(&tun->readq);
428         init_waitqueue_head(&tun->read_wait);
429
430         tun->owner = -1;
431         tun->group = -1;
432
433         dev->open = tun_net_open;
434         dev->hard_start_xmit = tun_net_xmit;
435         dev->stop = tun_net_close;
436         dev->ethtool_ops = &tun_ethtool_ops;
437         dev->destructor = free_netdev;
438 }
439
440 static struct tun_struct *tun_get_by_name(const char *name)
441 {
442         struct tun_struct *tun;
443
444         ASSERT_RTNL();
445         list_for_each_entry(tun, &tun_dev_list, list) {
446                 if (!strncmp(tun->dev->name, name, IFNAMSIZ))
447                     return tun;
448         }
449
450         return NULL;
451 }
452
453 static int tun_set_iff(struct file *file, struct ifreq *ifr)
454 {
455         struct tun_struct *tun;
456         struct net_device *dev;
457         int err;
458
459         tun = tun_get_by_name(ifr->ifr_name);
460         if (tun) {
461                 if (tun->attached)
462                         return -EBUSY;
463
464                 /* Check permissions */
465                 if (((tun->owner != -1 &&
466                       current->euid != tun->owner) ||
467                      (tun->group != -1 &&
468                       current->egid != tun->group)) &&
469                      !capable(CAP_NET_ADMIN))
470                         return -EPERM;
471         }
472         else if (__dev_get_by_name(&init_net, ifr->ifr_name))
473                 return -EINVAL;
474         else {
475                 char *name;
476                 unsigned long flags = 0;
477
478                 err = -EINVAL;
479
480                 if (!capable(CAP_NET_ADMIN))
481                         return -EPERM;
482
483                 /* Set dev type */
484                 if (ifr->ifr_flags & IFF_TUN) {
485                         /* TUN device */
486                         flags |= TUN_TUN_DEV;
487                         name = "tun%d";
488                 } else if (ifr->ifr_flags & IFF_TAP) {
489                         /* TAP device */
490                         flags |= TUN_TAP_DEV;
491                         name = "tap%d";
492                 } else
493                         goto failed;
494
495                 if (*ifr->ifr_name)
496                         name = ifr->ifr_name;
497
498                 dev = alloc_netdev(sizeof(struct tun_struct), name,
499                                    tun_setup);
500                 if (!dev)
501                         return -ENOMEM;
502
503                 tun = netdev_priv(dev);
504                 tun->dev = dev;
505                 tun->flags = flags;
506                 /* Be promiscuous by default to maintain previous behaviour. */
507                 tun->if_flags = IFF_PROMISC;
508                 /* Generate random Ethernet address. */
509                 *(__be16 *)tun->dev_addr = htons(0x00FF);
510                 get_random_bytes(tun->dev_addr + sizeof(u16), 4);
511                 memset(tun->chr_filter, 0, sizeof tun->chr_filter);
512
513                 tun_net_init(dev);
514
515                 if (strchr(dev->name, '%')) {
516                         err = dev_alloc_name(dev, dev->name);
517                         if (err < 0)
518                                 goto err_free_dev;
519                 }
520
521                 err = register_netdevice(tun->dev);
522                 if (err < 0)
523                         goto err_free_dev;
524
525                 list_add(&tun->list, &tun_dev_list);
526         }
527
528         DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
529
530         if (ifr->ifr_flags & IFF_NO_PI)
531                 tun->flags |= TUN_NO_PI;
532         else
533                 tun->flags &= ~TUN_NO_PI;
534
535         if (ifr->ifr_flags & IFF_ONE_QUEUE)
536                 tun->flags |= TUN_ONE_QUEUE;
537         else
538                 tun->flags &= ~TUN_ONE_QUEUE;
539
540         file->private_data = tun;
541         tun->attached = 1;
542
543         strcpy(ifr->ifr_name, tun->dev->name);
544         return 0;
545
546  err_free_dev:
547         free_netdev(dev);
548  failed:
549         return err;
550 }
551
552 static int tun_chr_ioctl(struct inode *inode, struct file *file,
553                          unsigned int cmd, unsigned long arg)
554 {
555         struct tun_struct *tun = file->private_data;
556         void __user* argp = (void __user*)arg;
557         struct ifreq ifr;
558         DECLARE_MAC_BUF(mac);
559
560         if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
561                 if (copy_from_user(&ifr, argp, sizeof ifr))
562                         return -EFAULT;
563
564         if (cmd == TUNSETIFF && !tun) {
565                 int err;
566
567                 ifr.ifr_name[IFNAMSIZ-1] = '\0';
568
569                 rtnl_lock();
570                 err = tun_set_iff(file, &ifr);
571                 rtnl_unlock();
572
573                 if (err)
574                         return err;
575
576                 if (copy_to_user(argp, &ifr, sizeof(ifr)))
577                         return -EFAULT;
578                 return 0;
579         }
580
581         if (!tun)
582                 return -EBADFD;
583
584         DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
585
586         switch (cmd) {
587         case TUNSETNOCSUM:
588                 /* Disable/Enable checksum */
589                 if (arg)
590                         tun->flags |= TUN_NOCHECKSUM;
591                 else
592                         tun->flags &= ~TUN_NOCHECKSUM;
593
594                 DBG(KERN_INFO "%s: checksum %s\n",
595                     tun->dev->name, arg ? "disabled" : "enabled");
596                 break;
597
598         case TUNSETPERSIST:
599                 /* Disable/Enable persist mode */
600                 if (arg)
601                         tun->flags |= TUN_PERSIST;
602                 else
603                         tun->flags &= ~TUN_PERSIST;
604
605                 DBG(KERN_INFO "%s: persist %s\n",
606                     tun->dev->name, arg ? "enabled" : "disabled");
607                 break;
608
609         case TUNSETOWNER:
610                 /* Set owner of the device */
611                 tun->owner = (uid_t) arg;
612
613                 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
614                 break;
615
616         case TUNSETGROUP:
617                 /* Set group of the device */
618                 tun->group= (gid_t) arg;
619
620                 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group);
621                 break;
622
623         case TUNSETLINK:
624                 /* Only allow setting the type when the interface is down */
625                 if (tun->dev->flags & IFF_UP) {
626                         DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
627                                 tun->dev->name);
628                         return -EBUSY;
629                 } else {
630                         tun->dev->type = (int) arg;
631                         DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
632                 }
633                 break;
634
635 #ifdef TUN_DEBUG
636         case TUNSETDEBUG:
637                 tun->debug = arg;
638                 break;
639 #endif
640
641         case SIOCGIFFLAGS:
642                 ifr.ifr_flags = tun->if_flags;
643                 if (copy_to_user( argp, &ifr, sizeof ifr))
644                         return -EFAULT;
645                 return 0;
646
647         case SIOCSIFFLAGS:
648                 /** Set the character device's interface flags. Currently only
649                  * IFF_PROMISC and IFF_ALLMULTI are used. */
650                 tun->if_flags = ifr.ifr_flags;
651                 DBG(KERN_INFO "%s: interface flags 0x%lx\n",
652                                 tun->dev->name, tun->if_flags);
653                 return 0;
654
655         case SIOCGIFHWADDR:
656                 /* Note: the actual net device's address may be different */
657                 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev_addr,
658                                 min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
659                 if (copy_to_user( argp, &ifr, sizeof ifr))
660                         return -EFAULT;
661                 return 0;
662
663         case SIOCSIFHWADDR:
664         {
665                 /* try to set the actual net device's hw address */
666                 int ret;
667
668                 rtnl_lock();
669                 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
670                 rtnl_unlock();
671
672                 if (ret == 0) {
673                         /** Set the character device's hardware address. This is used when
674                          * filtering packets being sent from the network device to the character
675                          * device. */
676                         memcpy(tun->dev_addr, ifr.ifr_hwaddr.sa_data,
677                                         min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
678                         DBG(KERN_DEBUG "%s: set hardware address: %x:%x:%x:%x:%x:%x\n",
679                                         tun->dev->name,
680                                         tun->dev_addr[0], tun->dev_addr[1], tun->dev_addr[2],
681                                         tun->dev_addr[3], tun->dev_addr[4], tun->dev_addr[5]);
682                 }
683
684                 return  ret;
685         }
686
687         case SIOCADDMULTI:
688                 /** Add the specified group to the character device's multicast filter
689                  * list. */
690                 add_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
691                 DBG(KERN_DEBUG "%s: add multi: %s\n",
692                     tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data));
693                 return 0;
694
695         case SIOCDELMULTI:
696                 /** Remove the specified group from the character device's multicast
697                  * filter list. */
698                 del_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
699                 DBG(KERN_DEBUG "%s: del multi: %s\n",
700                     tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data));
701                 return 0;
702
703         default:
704                 return -EINVAL;
705         };
706
707         return 0;
708 }
709
710 static int tun_chr_fasync(int fd, struct file *file, int on)
711 {
712         struct tun_struct *tun = file->private_data;
713         int ret;
714
715         if (!tun)
716                 return -EBADFD;
717
718         DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
719
720         if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
721                 return ret;
722
723         if (on) {
724                 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
725                 if (ret)
726                         return ret;
727                 tun->flags |= TUN_FASYNC;
728         } else
729                 tun->flags &= ~TUN_FASYNC;
730
731         return 0;
732 }
733
734 static int tun_chr_open(struct inode *inode, struct file * file)
735 {
736         DBG1(KERN_INFO "tunX: tun_chr_open\n");
737         file->private_data = NULL;
738         return 0;
739 }
740
741 static int tun_chr_close(struct inode *inode, struct file *file)
742 {
743         struct tun_struct *tun = file->private_data;
744
745         if (!tun)
746                 return 0;
747
748         DBG(KERN_INFO "%s: tun_chr_close\n", tun->dev->name);
749
750         tun_chr_fasync(-1, file, 0);
751
752         rtnl_lock();
753
754         /* Detach from net device */
755         file->private_data = NULL;
756         tun->attached = 0;
757
758         /* Drop read queue */
759         skb_queue_purge(&tun->readq);
760
761         if (!(tun->flags & TUN_PERSIST)) {
762                 list_del(&tun->list);
763                 unregister_netdevice(tun->dev);
764         }
765
766         rtnl_unlock();
767
768         return 0;
769 }
770
771 static const struct file_operations tun_fops = {
772         .owner  = THIS_MODULE,
773         .llseek = no_llseek,
774         .read  = do_sync_read,
775         .aio_read  = tun_chr_aio_read,
776         .write = do_sync_write,
777         .aio_write = tun_chr_aio_write,
778         .poll   = tun_chr_poll,
779         .ioctl  = tun_chr_ioctl,
780         .open   = tun_chr_open,
781         .release = tun_chr_close,
782         .fasync = tun_chr_fasync
783 };
784
785 static struct miscdevice tun_miscdev = {
786         .minor = TUN_MINOR,
787         .name = "tun",
788         .fops = &tun_fops,
789 };
790
791 /* ethtool interface */
792
793 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
794 {
795         cmd->supported          = 0;
796         cmd->advertising        = 0;
797         cmd->speed              = SPEED_10;
798         cmd->duplex             = DUPLEX_FULL;
799         cmd->port               = PORT_TP;
800         cmd->phy_address        = 0;
801         cmd->transceiver        = XCVR_INTERNAL;
802         cmd->autoneg            = AUTONEG_DISABLE;
803         cmd->maxtxpkt           = 0;
804         cmd->maxrxpkt           = 0;
805         return 0;
806 }
807
808 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
809 {
810         struct tun_struct *tun = netdev_priv(dev);
811
812         strcpy(info->driver, DRV_NAME);
813         strcpy(info->version, DRV_VERSION);
814         strcpy(info->fw_version, "N/A");
815
816         switch (tun->flags & TUN_TYPE_MASK) {
817         case TUN_TUN_DEV:
818                 strcpy(info->bus_info, "tun");
819                 break;
820         case TUN_TAP_DEV:
821                 strcpy(info->bus_info, "tap");
822                 break;
823         }
824 }
825
826 static u32 tun_get_msglevel(struct net_device *dev)
827 {
828 #ifdef TUN_DEBUG
829         struct tun_struct *tun = netdev_priv(dev);
830         return tun->debug;
831 #else
832         return -EOPNOTSUPP;
833 #endif
834 }
835
836 static void tun_set_msglevel(struct net_device *dev, u32 value)
837 {
838 #ifdef TUN_DEBUG
839         struct tun_struct *tun = netdev_priv(dev);
840         tun->debug = value;
841 #endif
842 }
843
844 static u32 tun_get_link(struct net_device *dev)
845 {
846         struct tun_struct *tun = netdev_priv(dev);
847         return tun->attached;
848 }
849
850 static u32 tun_get_rx_csum(struct net_device *dev)
851 {
852         struct tun_struct *tun = netdev_priv(dev);
853         return (tun->flags & TUN_NOCHECKSUM) == 0;
854 }
855
856 static int tun_set_rx_csum(struct net_device *dev, u32 data)
857 {
858         struct tun_struct *tun = netdev_priv(dev);
859         if (data)
860                 tun->flags &= ~TUN_NOCHECKSUM;
861         else
862                 tun->flags |= TUN_NOCHECKSUM;
863         return 0;
864 }
865
866 static const struct ethtool_ops tun_ethtool_ops = {
867         .get_settings   = tun_get_settings,
868         .get_drvinfo    = tun_get_drvinfo,
869         .get_msglevel   = tun_get_msglevel,
870         .set_msglevel   = tun_set_msglevel,
871         .get_link       = tun_get_link,
872         .get_rx_csum    = tun_get_rx_csum,
873         .set_rx_csum    = tun_set_rx_csum
874 };
875
876 static int __init tun_init(void)
877 {
878         int ret = 0;
879
880         printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
881         printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
882
883         ret = misc_register(&tun_miscdev);
884         if (ret)
885                 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
886         return ret;
887 }
888
889 static void tun_cleanup(void)
890 {
891         struct tun_struct *tun, *nxt;
892
893         misc_deregister(&tun_miscdev);
894
895         rtnl_lock();
896         list_for_each_entry_safe(tun, nxt, &tun_dev_list, list) {
897                 DBG(KERN_INFO "%s cleaned up\n", tun->dev->name);
898                 unregister_netdevice(tun->dev);
899         }
900         rtnl_unlock();
901
902 }
903
904 module_init(tun_init);
905 module_exit(tun_cleanup);
906 MODULE_DESCRIPTION(DRV_DESCRIPTION);
907 MODULE_AUTHOR(DRV_COPYRIGHT);
908 MODULE_LICENSE("GPL");
909 MODULE_ALIAS_MISCDEV(TUN_MINOR);