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 /* Uncomment to enable debugging */
  71 /* #define TUN_DEBUG 1 */
  72
  73 #ifdef TUN_DEBUG
  74 static int debug;
  75
  76 #define DBG  if(tun->debug)printk
  77 #define DBG1 if(debug==2)printk
  78 #else
  79 #define DBG( a... )
  80 #define DBG1( a... )
  81 #endif
  82
  83 struct tun_struct {
  84         struct list_head        list;
  85         unsigned long           flags;
  86         int                     attached;
  87         uid_t                   owner;
  88         gid_t                   group;
  89
  90         wait_queue_head_t       read_wait;
  91         struct sk_buff_head     readq;
  92
  93         struct net_device       *dev;
  94
  95         struct fasync_struct    *fasync;
  96
  97         unsigned long if_flags;
  98         u8 dev_addr[ETH_ALEN];
  99         u32 chr_filter[2];
 100         u32 net_filter[2];
 101
 102 #ifdef TUN_DEBUG
 103         int debug;
 104 #endif
 105 };
 106
 107 /* Network device part of the driver */
 108
 109 static LIST_HEAD(tun_dev_list);
 110 static const struct ethtool_ops tun_ethtool_ops;
 111
 112 /* Net device open. */
 113 static int tun_net_open(struct net_device *dev)
 114 {
 115         netif_start_queue(dev);
 116         return 0;
 117 }
 118
 119 /* Net device close. */
 120 static int tun_net_close(struct net_device *dev)
 121 {
 122         netif_stop_queue(dev);
 123         return 0;
 124 }
 125
 126 /* Net device start xmit */
 127 static int tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
 128 {
 129         struct tun_struct *tun = netdev_priv(dev);
 130
 131         DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len);
 132
 133         /* Drop packet if interface is not attached */
 134         if (!tun->attached)
 135                 goto drop;
 136
 137         /* Packet dropping */
 138         if (skb_queue_len(&tun->readq) >= dev->tx_queue_len) {
 139                 if (!(tun->flags & TUN_ONE_QUEUE)) {
 140                         /* Normal queueing mode. */
 141                         /* Packet scheduler handles dropping of further packets. */
 142                         netif_stop_queue(dev);
 143
 144                         /* We won't see all dropped packets individually, so overrun
 145                          * error is more appropriate. */
 146                         dev->stats.tx_fifo_errors++;
 147                 } else {
 148                         /* Single queue mode.
 149                          * Driver handles dropping of all packets itself. */
 150                         goto drop;
 151                 }
 152         }
 153
 154         /* Queue packet */
 155         skb_queue_tail(&tun->readq, skb);
 156         dev->trans_start = jiffies;
 157
 158         /* Notify and wake up reader process */
 159         if (tun->flags & TUN_FASYNC)
 160                 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
 161         wake_up_interruptible(&tun->read_wait);
 162         return 0;
 163
 164 drop:
 165         dev->stats.tx_dropped++;
 166         kfree_skb(skb);
 167         return 0;
 168 }
 169
 170 /** Add the specified Ethernet address to this multicast filter. */
 171 static void
 172 add_multi(u32* filter, const u8* addr)
 173 {
 174         int bit_nr = ether_crc(ETH_ALEN, addr) >> 26;
 175         filter[bit_nr >> 5] |= 1 << (bit_nr & 31);
 176 }
 177
 178 /** Remove the specified Ethernet addres from this multicast filter. */
 179 static void
 180 del_multi(u32* filter, const u8* addr)
 181 {
 182         int bit_nr = ether_crc(ETH_ALEN, addr) >> 26;
 183         filter[bit_nr >> 5] &= ~(1 << (bit_nr & 31));
 184 }
 185
 186 /** Update the list of multicast groups to which the network device belongs.
 187  * This list is used to filter packets being sent from the character device to
 188  * the network device. */
 189 static void
 190 tun_net_mclist(struct net_device *dev)
 191 {
 192         struct tun_struct *tun = netdev_priv(dev);
 193         const struct dev_mc_list *mclist;
 194         int i;
 195         DECLARE_MAC_BUF(mac);
 196         DBG(KERN_DEBUG "%s: tun_net_mclist: mc_count %d\n",
 197                         dev->name, dev->mc_count);
 198         memset(tun->chr_filter, 0, sizeof tun->chr_filter);
 199         for (i = 0, mclist = dev->mc_list; i < dev->mc_count && mclist != NULL;
 200                         i++, mclist = mclist->next) {
 201                 add_multi(tun->net_filter, mclist->dmi_addr);
 202                 DBG(KERN_DEBUG "%s: tun_net_mclist: %s\n",
 203                     dev->name, print_mac(mac, mclist->dmi_addr));
 204         }
 205 }
 206
 207 #define MIN_MTU 68
 208 #define MAX_MTU 65535
 209
 210 static int
 211 tun_net_change_mtu(struct net_device *dev, int new_mtu)
 212 {
 213         if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
 214                 return -EINVAL;
 215         dev->mtu = new_mtu;
 216         return 0;
 217 }
 218
 219 /* Initialize net device. */
 220 static void tun_net_init(struct net_device *dev)
 221 {
 222         struct tun_struct *tun = netdev_priv(dev);
 223
 224         switch (tun->flags & TUN_TYPE_MASK) {
 225         case TUN_TUN_DEV:
 226                 /* Point-to-Point TUN Device */
 227                 dev->hard_header_len = 0;
 228                 dev->addr_len = 0;
 229                 dev->mtu = 1500;
 230                 dev->change_mtu = tun_net_change_mtu;
 231
 232                 /* Zero header length */
 233                 dev->type = ARPHRD_NONE;
 234                 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
 235                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
 236                 break;
 237
 238         case TUN_TAP_DEV:
 239                 /* Ethernet TAP Device */
 240                 dev->set_multicast_list = tun_net_mclist;
 241
 242                 ether_setup(dev);
 243                 dev->change_mtu = tun_net_change_mtu;
 244
 245                 /* random address already created for us by tun_set_iff, use it */
 246                 memcpy(dev->dev_addr, tun->dev_addr, min(sizeof(tun->dev_addr), sizeof(dev->dev_addr)) );
 247
 248                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
 249                 break;
 250         }
 251 }
 252
 253 /* Character device part */
 254
 255 /* Poll */
 256 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
 257 {
 258         struct tun_struct *tun = file->private_data;
 259         unsigned int mask = POLLOUT | POLLWRNORM;
 260
 261         if (!tun)
 262                 return -EBADFD;
 263
 264         DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
 265
 266         poll_wait(file, &tun->read_wait, wait);
 267
 268         if (!skb_queue_empty(&tun->readq))
 269                 mask |= POLLIN | POLLRDNORM;
 270
 271         return mask;
 272 }
 273
 274 /* Get packet from user space buffer */
 275 static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, size_t count)
 276 {
 277         struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) };
 278         struct sk_buff *skb;
 279         size_t len = count, align = 0;
 280
 281         if (!(tun->flags & TUN_NO_PI)) {
 282                 if ((len -= sizeof(pi)) > count)
 283                         return -EINVAL;
 284
 285                 if(memcpy_fromiovec((void *)&pi, iv, sizeof(pi)))
 286                         return -EFAULT;
 287         }
 288
 289         if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV)
 290                 align = NET_IP_ALIGN;
 291
 292         if (!(skb = alloc_skb(len + align, GFP_KERNEL))) {
 293                 tun->dev->stats.rx_dropped++;
 294                 return -ENOMEM;
 295         }
 296
 297         if (align)
 298                 skb_reserve(skb, align);
 299         if (memcpy_fromiovec(skb_put(skb, len), iv, len)) {
 300                 tun->dev->stats.rx_dropped++;
 301                 kfree_skb(skb);
 302                 return -EFAULT;
 303         }
 304
 305         switch (tun->flags & TUN_TYPE_MASK) {
 306         case TUN_TUN_DEV:
 307                 skb_reset_mac_header(skb);
 308                 skb->protocol = pi.proto;
 309                 skb->dev = tun->dev;
 310                 break;
 311         case TUN_TAP_DEV:
 312                 skb->protocol = eth_type_trans(skb, tun->dev);
 313                 break;
 314         };
 315
 316         if (tun->flags & TUN_NOCHECKSUM)
 317                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 318
 319         netif_rx_ni(skb);
 320         tun->dev->last_rx = jiffies;
 321
 322         tun->dev->stats.rx_packets++;
 323         tun->dev->stats.rx_bytes += len;
 324
 325         return count;
 326 }
 327
 328 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
 329                               unsigned long count, loff_t pos)
 330 {
 331         struct tun_struct *tun = iocb->ki_filp->private_data;
 332
 333         if (!tun)
 334                 return -EBADFD;
 335
 336         DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
 337
 338         return tun_get_user(tun, (struct iovec *) iv, iov_length(iv, count));
 339 }
 340
 341 /* Put packet to the user space buffer */
 342 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
 343                                        struct sk_buff *skb,
 344                                        struct iovec *iv, int len)
 345 {
 346         struct tun_pi pi = { 0, skb->protocol };
 347         ssize_t total = 0;
 348
 349         if (!(tun->flags & TUN_NO_PI)) {
 350                 if ((len -= sizeof(pi)) < 0)
 351                         return -EINVAL;
 352
 353                 if (len < skb->len) {
 354                         /* Packet will be striped */
 355                         pi.flags |= TUN_PKT_STRIP;
 356                 }
 357
 358                 if (memcpy_toiovec(iv, (void *) &pi, sizeof(pi)))
 359                         return -EFAULT;
 360                 total += sizeof(pi);
 361         }
 362
 363         len = min_t(int, skb->len, len);
 364
 365         skb_copy_datagram_iovec(skb, 0, iv, len);
 366         total += len;
 367
 368         tun->dev->stats.tx_packets++;
 369         tun->dev->stats.tx_bytes += len;
 370
 371         return total;
 372 }
 373
 374 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
 375                             unsigned long count, loff_t pos)
 376 {
 377         struct file *file = iocb->ki_filp;
 378         struct tun_struct *tun = file->private_data;
 379         DECLARE_WAITQUEUE(wait, current);
 380         struct sk_buff *skb;
 381         ssize_t len, ret = 0;
 382         DECLARE_MAC_BUF(mac);
 383
 384         if (!tun)
 385                 return -EBADFD;
 386
 387         DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
 388
 389         len = iov_length(iv, count);
 390         if (len < 0)
 391                 return -EINVAL;
 392
 393         add_wait_queue(&tun->read_wait, &wait);
 394         while (len) {
 395                 const u8 ones[ ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
 396                 u8 addr[ ETH_ALEN];
 397                 int bit_nr;
 398
 399                 current->state = TASK_INTERRUPTIBLE;
 400
 401                 /* Read frames from the queue */
 402                 if (!(skb=skb_dequeue(&tun->readq))) {
 403                         if (file->f_flags & O_NONBLOCK) {
 404                                 ret = -EAGAIN;
 405                                 break;
 406                         }
 407                         if (signal_pending(current)) {
 408                                 ret = -ERESTARTSYS;
 409                                 break;
 410                         }
 411
 412                         /* Nothing to read, let's sleep */
 413                         schedule();
 414                         continue;
 415                 }
 416                 netif_wake_queue(tun->dev);
 417
 418                 /** Decide whether to accept this packet. This code is designed to
 419                  * behave identically to an Ethernet interface. Accept the packet if
 420                  * - we are promiscuous.
 421                  * - the packet is addressed to us.
 422                  * - the packet is broadcast.
 423                  * - the packet is multicast and
 424                  *   - we are multicast promiscous.
 425                  *   - we belong to the multicast group.
 426                  */
 427                 skb_copy_from_linear_data(skb, addr, min_t(size_t, sizeof addr,
 428                                                                    skb->len));
 429                 bit_nr = ether_crc(sizeof addr, addr) >> 26;
 430                 if ((tun->if_flags & IFF_PROMISC) ||
 431                                 memcmp(addr, tun->dev_addr, sizeof addr) == 0 ||
 432                                 memcmp(addr, ones, sizeof addr) == 0 ||
 433                                 (((addr[0] == 1 && addr[1] == 0 && addr[2] == 0x5e) ||
 434                                   (addr[0] == 0x33 && addr[1] == 0x33)) &&
 435                                  ((tun->if_flags & IFF_ALLMULTI) ||
 436                                   (tun->chr_filter[bit_nr >> 5] & (1 << (bit_nr & 31)))))) {
 437                         DBG(KERN_DEBUG "%s: tun_chr_readv: accepted: %s\n",
 438                                         tun->dev->name, print_mac(mac, addr));
 439                         ret = tun_put_user(tun, skb, (struct iovec *) iv, len);
 440                         kfree_skb(skb);
 441                         break;
 442                 } else {
 443                         DBG(KERN_DEBUG "%s: tun_chr_readv: rejected: %s\n",
 444                                         tun->dev->name, print_mac(mac, addr));
 445                         kfree_skb(skb);
 446                         continue;
 447                 }
 448         }
 449
 450         current->state = TASK_RUNNING;
 451         remove_wait_queue(&tun->read_wait, &wait);
 452
 453         return ret;
 454 }
 455
 456 static void tun_setup(struct net_device *dev)
 457 {
 458         struct tun_struct *tun = netdev_priv(dev);
 459
 460         skb_queue_head_init(&tun->readq);
 461         init_waitqueue_head(&tun->read_wait);
 462
 463         tun->owner = -1;
 464         tun->group = -1;
 465
 466         dev->open = tun_net_open;
 467         dev->hard_start_xmit = tun_net_xmit;
 468         dev->stop = tun_net_close;
 469         dev->ethtool_ops = &tun_ethtool_ops;
 470         dev->destructor = free_netdev;
 471 }
 472
 473 static struct tun_struct *tun_get_by_name(const char *name)
 474 {
 475         struct tun_struct *tun;
 476
 477         ASSERT_RTNL();
 478         list_for_each_entry(tun, &tun_dev_list, list) {
 479                 if (!strncmp(tun->dev->name, name, IFNAMSIZ))
 480                     return tun;
 481         }
 482
 483         return NULL;
 484 }
 485
 486 static int tun_set_iff(struct file *file, struct ifreq *ifr)
 487 {
 488         struct tun_struct *tun;
 489         struct net_device *dev;
 490         int err;
 491
 492         tun = tun_get_by_name(ifr->ifr_name);
 493         if (tun) {
 494                 if (tun->attached)
 495                         return -EBUSY;
 496
 497                 /* Check permissions */
 498                 if (((tun->owner != -1 &&
 499                       current->euid != tun->owner) ||
 500                      (tun->group != -1 &&
 501                       current->egid != tun->group)) &&
 502                      !capable(CAP_NET_ADMIN))
 503                         return -EPERM;
 504         }
 505         else if (__dev_get_by_name(&init_net, ifr->ifr_name))
 506                 return -EINVAL;
 507         else {
 508                 char *name;
 509                 unsigned long flags = 0;
 510
 511                 err = -EINVAL;
 512
 513                 if (!capable(CAP_NET_ADMIN))
 514                         return -EPERM;
 515
 516                 /* Set dev type */
 517                 if (ifr->ifr_flags & IFF_TUN) {
 518                         /* TUN device */
 519                         flags |= TUN_TUN_DEV;
 520                         name = "tun%d";
 521                 } else if (ifr->ifr_flags & IFF_TAP) {
 522                         /* TAP device */
 523                         flags |= TUN_TAP_DEV;
 524                         name = "tap%d";
 525                 } else
 526                         goto failed;
 527
 528                 if (*ifr->ifr_name)
 529                         name = ifr->ifr_name;
 530
 531                 dev = alloc_netdev(sizeof(struct tun_struct), name,
 532                                    tun_setup);
 533                 if (!dev)
 534                         return -ENOMEM;
 535
 536                 tun = netdev_priv(dev);
 537                 tun->dev = dev;
 538                 tun->flags = flags;
 539                 /* Be promiscuous by default to maintain previous behaviour. */
 540                 tun->if_flags = IFF_PROMISC;
 541                 /* Generate random Ethernet address. */
 542                 *(__be16 *)tun->dev_addr = htons(0x00FF);
 543                 get_random_bytes(tun->dev_addr + sizeof(u16), 4);
 544                 memset(tun->chr_filter, 0, sizeof tun->chr_filter);
 545
 546                 tun_net_init(dev);
 547
 548                 if (strchr(dev->name, '%')) {
 549                         err = dev_alloc_name(dev, dev->name);
 550                         if (err < 0)
 551                                 goto err_free_dev;
 552                 }
 553
 554                 err = register_netdevice(tun->dev);
 555                 if (err < 0)
 556                         goto err_free_dev;
 557
 558                 list_add(&tun->list, &tun_dev_list);
 559         }
 560
 561         DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
 562
 563         if (ifr->ifr_flags & IFF_NO_PI)
 564                 tun->flags |= TUN_NO_PI;
 565         else
 566                 tun->flags &= ~TUN_NO_PI;
 567
 568         if (ifr->ifr_flags & IFF_ONE_QUEUE)
 569                 tun->flags |= TUN_ONE_QUEUE;
 570         else
 571                 tun->flags &= ~TUN_ONE_QUEUE;
 572
 573         file->private_data = tun;
 574         tun->attached = 1;
 575
 576         strcpy(ifr->ifr_name, tun->dev->name);
 577         return 0;
 578
 579  err_free_dev:
 580         free_netdev(dev);
 581  failed:
 582         return err;
 583 }
 584
 585 static int tun_chr_ioctl(struct inode *inode, struct file *file,
 586                          unsigned int cmd, unsigned long arg)
 587 {
 588         struct tun_struct *tun = file->private_data;
 589         void __user* argp = (void __user*)arg;
 590         struct ifreq ifr;
 591         DECLARE_MAC_BUF(mac);
 592
 593         if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
 594                 if (copy_from_user(&ifr, argp, sizeof ifr))
 595                         return -EFAULT;
 596
 597         if (cmd == TUNSETIFF && !tun) {
 598                 int err;
 599
 600                 ifr.ifr_name[IFNAMSIZ-1] = '\0';
 601
 602                 rtnl_lock();
 603                 err = tun_set_iff(file, &ifr);
 604                 rtnl_unlock();
 605
 606                 if (err)
 607                         return err;
 608
 609                 if (copy_to_user(argp, &ifr, sizeof(ifr)))
 610                         return -EFAULT;
 611                 return 0;
 612         }
 613
 614         if (!tun)
 615                 return -EBADFD;
 616
 617         DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
 618
 619         switch (cmd) {
 620         case TUNSETNOCSUM:
 621                 /* Disable/Enable checksum */
 622                 if (arg)
 623                         tun->flags |= TUN_NOCHECKSUM;
 624                 else
 625                         tun->flags &= ~TUN_NOCHECKSUM;
 626
 627                 DBG(KERN_INFO "%s: checksum %s\n",
 628                     tun->dev->name, arg ? "disabled" : "enabled");
 629                 break;
 630
 631         case TUNSETPERSIST:
 632                 /* Disable/Enable persist mode */
 633                 if (arg)
 634                         tun->flags |= TUN_PERSIST;
 635                 else
 636                         tun->flags &= ~TUN_PERSIST;
 637
 638                 DBG(KERN_INFO "%s: persist %s\n",
 639                     tun->dev->name, arg ? "enabled" : "disabled");
 640                 break;
 641
 642         case TUNSETOWNER:
 643                 /* Set owner of the device */
 644                 tun->owner = (uid_t) arg;
 645
 646                 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
 647                 break;
 648
 649         case TUNSETGROUP:
 650                 /* Set group of the device */
 651                 tun->group= (gid_t) arg;
 652
 653                 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group);
 654                 break;
 655
 656         case TUNSETLINK:
 657                 /* Only allow setting the type when the interface is down */
 658                 if (tun->dev->flags & IFF_UP) {
 659                         DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
 660                                 tun->dev->name);
 661                         return -EBUSY;
 662                 } else {
 663                         tun->dev->type = (int) arg;
 664                         DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
 665                 }
 666                 break;
 667
 668 #ifdef TUN_DEBUG
 669         case TUNSETDEBUG:
 670                 tun->debug = arg;
 671                 break;
 672 #endif
 673
 674         case SIOCGIFFLAGS:
 675                 ifr.ifr_flags = tun->if_flags;
 676                 if (copy_to_user( argp, &ifr, sizeof ifr))
 677                         return -EFAULT;
 678                 return 0;
 679
 680         case SIOCSIFFLAGS:
 681                 /** Set the character device's interface flags. Currently only
 682                  * IFF_PROMISC and IFF_ALLMULTI are used. */
 683                 tun->if_flags = ifr.ifr_flags;
 684                 DBG(KERN_INFO "%s: interface flags 0x%lx\n",
 685                                 tun->dev->name, tun->if_flags);
 686                 return 0;
 687
 688         case SIOCGIFHWADDR:
 689                 /* Note: the actual net device's address may be different */
 690                 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev_addr,
 691                                 min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
 692                 if (copy_to_user( argp, &ifr, sizeof ifr))
 693                         return -EFAULT;
 694                 return 0;
 695
 696         case SIOCSIFHWADDR:
 697         {
 698                 /* try to set the actual net device's hw address */
 699                 int ret;
 700
 701                 rtnl_lock();
 702                 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
 703                 rtnl_unlock();
 704
 705                 if (ret == 0) {
 706                         /** Set the character device's hardware address. This is used when
 707                          * filtering packets being sent from the network device to the character
 708                          * device. */
 709                         memcpy(tun->dev_addr, ifr.ifr_hwaddr.sa_data,
 710                                         min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
 711                         DBG(KERN_DEBUG "%s: set hardware address: %x:%x:%x:%x:%x:%x\n",
 712                                         tun->dev->name,
 713                                         tun->dev_addr[0], tun->dev_addr[1], tun->dev_addr[2],
 714                                         tun->dev_addr[3], tun->dev_addr[4], tun->dev_addr[5]);
 715                 }
 716
 717                 return  ret;
 718         }
 719
 720         case SIOCADDMULTI:
 721                 /** Add the specified group to the character device's multicast filter
 722                  * list. */
 723                 add_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
 724                 DBG(KERN_DEBUG "%s: add multi: %s\n",
 725                     tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data));
 726                 return 0;
 727
 728         case SIOCDELMULTI:
 729                 /** Remove the specified group from the character device's multicast
 730                  * filter list. */
 731                 del_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
 732                 DBG(KERN_DEBUG "%s: del multi: %s\n",
 733                     tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data));
 734                 return 0;
 735
 736         default:
 737                 return -EINVAL;
 738         };
 739
 740         return 0;
 741 }
 742
 743 static int tun_chr_fasync(int fd, struct file *file, int on)
 744 {
 745         struct tun_struct *tun = file->private_data;
 746         int ret;
 747
 748         if (!tun)
 749                 return -EBADFD;
 750
 751         DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
 752
 753         if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
 754                 return ret;
 755
 756         if (on) {
 757                 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
 758                 if (ret)
 759                         return ret;
 760                 tun->flags |= TUN_FASYNC;
 761         } else
 762                 tun->flags &= ~TUN_FASYNC;
 763
 764         return 0;
 765 }
 766
 767 static int tun_chr_open(struct inode *inode, struct file * file)
 768 {
 769         DBG1(KERN_INFO "tunX: tun_chr_open\n");
 770         file->private_data = NULL;
 771         return 0;
 772 }
 773
 774 static int tun_chr_close(struct inode *inode, struct file *file)
 775 {
 776         struct tun_struct *tun = file->private_data;
 777
 778         if (!tun)
 779                 return 0;
 780
 781         DBG(KERN_INFO "%s: tun_chr_close\n", tun->dev->name);
 782
 783         tun_chr_fasync(-1, file, 0);
 784
 785         rtnl_lock();
 786
 787         /* Detach from net device */
 788         file->private_data = NULL;
 789         tun->attached = 0;
 790
 791         /* Drop read queue */
 792         skb_queue_purge(&tun->readq);
 793
 794         if (!(tun->flags & TUN_PERSIST)) {
 795                 list_del(&tun->list);
 796                 unregister_netdevice(tun->dev);
 797         }
 798
 799         rtnl_unlock();
 800
 801         return 0;
 802 }
 803
 804 static const struct file_operations tun_fops = {
 805         .owner  = THIS_MODULE,
 806         .llseek = no_llseek,
 807         .read  = do_sync_read,
 808         .aio_read  = tun_chr_aio_read,
 809         .write = do_sync_write,
 810         .aio_write = tun_chr_aio_write,
 811         .poll   = tun_chr_poll,
 812         .ioctl  = tun_chr_ioctl,
 813         .open   = tun_chr_open,
 814         .release = tun_chr_close,
 815         .fasync = tun_chr_fasync
 816 };
 817
 818 static struct miscdevice tun_miscdev = {
 819         .minor = TUN_MINOR,
 820         .name = "tun",
 821         .fops = &tun_fops,
 822 };
 823
 824 /* ethtool interface */
 825
 826 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
 827 {
 828         cmd->supported          = 0;
 829         cmd->advertising        = 0;
 830         cmd->speed              = SPEED_10;
 831         cmd->duplex             = DUPLEX_FULL;
 832         cmd->port               = PORT_TP;
 833         cmd->phy_address        = 0;
 834         cmd->transceiver        = XCVR_INTERNAL;
 835         cmd->autoneg            = AUTONEG_DISABLE;
 836         cmd->maxtxpkt           = 0;
 837         cmd->maxrxpkt           = 0;
 838         return 0;
 839 }
 840
 841 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 842 {
 843         struct tun_struct *tun = netdev_priv(dev);
 844
 845         strcpy(info->driver, DRV_NAME);
 846         strcpy(info->version, DRV_VERSION);
 847         strcpy(info->fw_version, "N/A");
 848
 849         switch (tun->flags & TUN_TYPE_MASK) {
 850         case TUN_TUN_DEV:
 851                 strcpy(info->bus_info, "tun");
 852                 break;
 853         case TUN_TAP_DEV:
 854                 strcpy(info->bus_info, "tap");
 855                 break;
 856         }
 857 }
 858
 859 static u32 tun_get_msglevel(struct net_device *dev)
 860 {
 861 #ifdef TUN_DEBUG
 862         struct tun_struct *tun = netdev_priv(dev);
 863         return tun->debug;
 864 #else
 865         return -EOPNOTSUPP;
 866 #endif
 867 }
 868
 869 static void tun_set_msglevel(struct net_device *dev, u32 value)
 870 {
 871 #ifdef TUN_DEBUG
 872         struct tun_struct *tun = netdev_priv(dev);
 873         tun->debug = value;
 874 #endif
 875 }
 876
 877 static u32 tun_get_link(struct net_device *dev)
 878 {
 879         struct tun_struct *tun = netdev_priv(dev);
 880         return tun->attached;
 881 }
 882
 883 static u32 tun_get_rx_csum(struct net_device *dev)
 884 {
 885         struct tun_struct *tun = netdev_priv(dev);
 886         return (tun->flags & TUN_NOCHECKSUM) == 0;
 887 }
 888
 889 static int tun_set_rx_csum(struct net_device *dev, u32 data)
 890 {
 891         struct tun_struct *tun = netdev_priv(dev);
 892         if (data)
 893                 tun->flags &= ~TUN_NOCHECKSUM;
 894         else
 895                 tun->flags |= TUN_NOCHECKSUM;
 896         return 0;
 897 }
 898
 899 static const struct ethtool_ops tun_ethtool_ops = {
 900         .get_settings   = tun_get_settings,
 901         .get_drvinfo    = tun_get_drvinfo,
 902         .get_msglevel   = tun_get_msglevel,
 903         .set_msglevel   = tun_set_msglevel,
 904         .get_link       = tun_get_link,
 905         .get_rx_csum    = tun_get_rx_csum,
 906         .set_rx_csum    = tun_set_rx_csum
 907 };
 908
 909 static int __init tun_init(void)
 910 {
 911         int ret = 0;
 912
 913         printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
 914         printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
 915
 916         ret = misc_register(&tun_miscdev);
 917         if (ret)
 918                 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
 919         return ret;
 920 }
 921
 922 static void tun_cleanup(void)
 923 {
 924         struct tun_struct *tun, *nxt;
 925
 926         misc_deregister(&tun_miscdev);
 927
 928         rtnl_lock();
 929         list_for_each_entry_safe(tun, nxt, &tun_dev_list, list) {
 930                 DBG(KERN_INFO "%s cleaned up\n", tun->dev->name);
 931                 unregister_netdevice(tun->dev);
 932         }
 933         rtnl_unlock();
 934
 935 }
 936
 937 module_init(tun_init);
 938 module_exit(tun_cleanup);
 939 MODULE_DESCRIPTION(DRV_DESCRIPTION);
 940 MODULE_AUTHOR(DRV_COPYRIGHT);
 941 MODULE_LICENSE("GPL");
 942 MODULE_ALIAS_MISCDEV(TUN_MINOR);