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