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/smp_lock.h>
  52 #include <linux/poll.h>
  53 #include <linux/fcntl.h>
  54 #include <linux/init.h>
  55 #include <linux/skbuff.h>
  56 #include <linux/netdevice.h>
  57 #include <linux/etherdevice.h>
  58 #include <linux/miscdevice.h>
  59 #include <linux/ethtool.h>
  60 #include <linux/rtnetlink.h>
  61 #include <linux/if.h>
  62 #include <linux/if_arp.h>
  63 #include <linux/if_ether.h>
  64 #include <linux/if_tun.h>
  65 #include <linux/crc32.h>
  66 #include <linux/nsproxy.h>
  67 #include <net/net_namespace.h>
  68 #include <net/netns/generic.h>
  69
  70 #include <asm/system.h>
  71 #include <asm/uaccess.h>
  72
  73 /* Uncomment to enable debugging */
  74 /* #define TUN_DEBUG 1 */
  75
  76 #ifdef TUN_DEBUG
  77 static int debug;
  78
  79 #define DBG  if(tun->debug)printk
  80 #define DBG1 if(debug==2)printk
  81 #else
  82 #define DBG( a... )
  83 #define DBG1( a... )
  84 #endif
  85
  86 struct tun_struct {
  87         struct list_head        list;
  88         unsigned long           flags;
  89         int                     attached;
  90         uid_t                   owner;
  91         gid_t                   group;
  92
  93         wait_queue_head_t       read_wait;
  94         struct sk_buff_head     readq;
  95
  96         struct net_device       *dev;
  97
  98         struct fasync_struct    *fasync;
  99
 100         unsigned long if_flags;
 101         u8 dev_addr[ETH_ALEN];
 102         u32 chr_filter[2];
 103         u32 net_filter[2];
 104
 105 #ifdef TUN_DEBUG
 106         int debug;
 107 #endif
 108 };
 109
 110 /* Network device part of the driver */
 111
 112 static unsigned int tun_net_id;
 113 struct tun_net {
 114         struct list_head dev_list;
 115 };
 116
 117 static const struct ethtool_ops tun_ethtool_ops;
 118
 119 /* Net device open. */
 120 static int tun_net_open(struct net_device *dev)
 121 {
 122         netif_start_queue(dev);
 123         return 0;
 124 }
 125
 126 /* Net device close. */
 127 static int tun_net_close(struct net_device *dev)
 128 {
 129         netif_stop_queue(dev);
 130         return 0;
 131 }
 132
 133 /* Net device start xmit */
 134 static int tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
 135 {
 136         struct tun_struct *tun = netdev_priv(dev);
 137
 138         DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len);
 139
 140         /* Drop packet if interface is not attached */
 141         if (!tun->attached)
 142                 goto drop;
 143
 144         /* Packet dropping */
 145         if (skb_queue_len(&tun->readq) >= dev->tx_queue_len) {
 146                 if (!(tun->flags & TUN_ONE_QUEUE)) {
 147                         /* Normal queueing mode. */
 148                         /* Packet scheduler handles dropping of further packets. */
 149                         netif_stop_queue(dev);
 150
 151                         /* We won't see all dropped packets individually, so overrun
 152                          * error is more appropriate. */
 153                         dev->stats.tx_fifo_errors++;
 154                 } else {
 155                         /* Single queue mode.
 156                          * Driver handles dropping of all packets itself. */
 157                         goto drop;
 158                 }
 159         }
 160
 161         /* Queue packet */
 162         skb_queue_tail(&tun->readq, skb);
 163         dev->trans_start = jiffies;
 164
 165         /* Notify and wake up reader process */
 166         if (tun->flags & TUN_FASYNC)
 167                 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
 168         wake_up_interruptible(&tun->read_wait);
 169         return 0;
 170
 171 drop:
 172         dev->stats.tx_dropped++;
 173         kfree_skb(skb);
 174         return 0;
 175 }
 176
 177 /** Add the specified Ethernet address to this multicast filter. */
 178 static void
 179 add_multi(u32* filter, const u8* addr)
 180 {
 181         int bit_nr = ether_crc(ETH_ALEN, addr) >> 26;
 182         filter[bit_nr >> 5] |= 1 << (bit_nr & 31);
 183 }
 184
 185 /** Remove the specified Ethernet addres from this multicast filter. */
 186 static void
 187 del_multi(u32* filter, const u8* addr)
 188 {
 189         int bit_nr = ether_crc(ETH_ALEN, addr) >> 26;
 190         filter[bit_nr >> 5] &= ~(1 << (bit_nr & 31));
 191 }
 192
 193 /** Update the list of multicast groups to which the network device belongs.
 194  * This list is used to filter packets being sent from the character device to
 195  * the network device. */
 196 static void
 197 tun_net_mclist(struct net_device *dev)
 198 {
 199         struct tun_struct *tun = netdev_priv(dev);
 200         const struct dev_mc_list *mclist;
 201         int i;
 202         DECLARE_MAC_BUF(mac);
 203         DBG(KERN_DEBUG "%s: tun_net_mclist: mc_count %d\n",
 204                         dev->name, dev->mc_count);
 205         memset(tun->chr_filter, 0, sizeof tun->chr_filter);
 206         for (i = 0, mclist = dev->mc_list; i < dev->mc_count && mclist != NULL;
 207                         i++, mclist = mclist->next) {
 208                 add_multi(tun->net_filter, mclist->dmi_addr);
 209                 DBG(KERN_DEBUG "%s: tun_net_mclist: %s\n",
 210                     dev->name, print_mac(mac, mclist->dmi_addr));
 211         }
 212 }
 213
 214 #define MIN_MTU 68
 215 #define MAX_MTU 65535
 216
 217 static int
 218 tun_net_change_mtu(struct net_device *dev, int new_mtu)
 219 {
 220         if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
 221                 return -EINVAL;
 222         dev->mtu = new_mtu;
 223         return 0;
 224 }
 225
 226 /* Initialize net device. */
 227 static void tun_net_init(struct net_device *dev)
 228 {
 229         struct tun_struct *tun = netdev_priv(dev);
 230
 231         switch (tun->flags & TUN_TYPE_MASK) {
 232         case TUN_TUN_DEV:
 233                 /* Point-to-Point TUN Device */
 234                 dev->hard_header_len = 0;
 235                 dev->addr_len = 0;
 236                 dev->mtu = 1500;
 237                 dev->change_mtu = tun_net_change_mtu;
 238
 239                 /* Zero header length */
 240                 dev->type = ARPHRD_NONE;
 241                 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
 242                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
 243                 break;
 244
 245         case TUN_TAP_DEV:
 246                 /* Ethernet TAP Device */
 247                 dev->set_multicast_list = tun_net_mclist;
 248
 249                 ether_setup(dev);
 250                 dev->change_mtu = tun_net_change_mtu;
 251
 252                 /* random address already created for us by tun_set_iff, use it */
 253                 memcpy(dev->dev_addr, tun->dev_addr, min(sizeof(tun->dev_addr), sizeof(dev->dev_addr)) );
 254
 255                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
 256                 break;
 257         }
 258 }
 259
 260 /* Character device part */
 261
 262 /* Poll */
 263 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
 264 {
 265         struct tun_struct *tun = file->private_data;
 266         unsigned int mask = POLLOUT | POLLWRNORM;
 267
 268         if (!tun)
 269                 return -EBADFD;
 270
 271         DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
 272
 273         poll_wait(file, &tun->read_wait, wait);
 274
 275         if (!skb_queue_empty(&tun->readq))
 276                 mask |= POLLIN | POLLRDNORM;
 277
 278         return mask;
 279 }
 280
 281 /* Get packet from user space buffer */
 282 static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, size_t count)
 283 {
 284         struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) };
 285         struct sk_buff *skb;
 286         size_t len = count, align = 0;
 287
 288         if (!(tun->flags & TUN_NO_PI)) {
 289                 if ((len -= sizeof(pi)) > count)
 290                         return -EINVAL;
 291
 292                 if(memcpy_fromiovec((void *)&pi, iv, sizeof(pi)))
 293                         return -EFAULT;
 294         }
 295
 296         if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
 297                 align = NET_IP_ALIGN;
 298                 if (unlikely(len < ETH_HLEN))
 299                         return -EINVAL;
 300         }
 301
 302         if (!(skb = alloc_skb(len + align, GFP_KERNEL))) {
 303                 tun->dev->stats.rx_dropped++;
 304                 return -ENOMEM;
 305         }
 306
 307         if (align)
 308                 skb_reserve(skb, align);
 309         if (memcpy_fromiovec(skb_put(skb, len), iv, len)) {
 310                 tun->dev->stats.rx_dropped++;
 311                 kfree_skb(skb);
 312                 return -EFAULT;
 313         }
 314
 315         switch (tun->flags & TUN_TYPE_MASK) {
 316         case TUN_TUN_DEV:
 317                 if (tun->flags & TUN_NO_PI) {
 318                         switch (skb->data[0] & 0xf0) {
 319                         case 0x40:
 320                                 pi.proto = htons(ETH_P_IP);
 321                                 break;
 322                         case 0x60:
 323                                 pi.proto = htons(ETH_P_IPV6);
 324                                 break;
 325                         default:
 326                                 tun->dev->stats.rx_dropped++;
 327                                 kfree_skb(skb);
 328                                 return -EINVAL;
 329                         }
 330                 }
 331
 332                 skb_reset_mac_header(skb);
 333                 skb->protocol = pi.proto;
 334                 skb->dev = tun->dev;
 335                 break;
 336         case TUN_TAP_DEV:
 337                 skb->protocol = eth_type_trans(skb, tun->dev);
 338                 break;
 339         };
 340
 341         if (tun->flags & TUN_NOCHECKSUM)
 342                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 343
 344         netif_rx_ni(skb);
 345         tun->dev->last_rx = jiffies;
 346
 347         tun->dev->stats.rx_packets++;
 348         tun->dev->stats.rx_bytes += len;
 349
 350         return count;
 351 }
 352
 353 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
 354                               unsigned long count, loff_t pos)
 355 {
 356         struct tun_struct *tun = iocb->ki_filp->private_data;
 357
 358         if (!tun)
 359                 return -EBADFD;
 360
 361         DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
 362
 363         return tun_get_user(tun, (struct iovec *) iv, iov_length(iv, count));
 364 }
 365
 366 /* Put packet to the user space buffer */
 367 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
 368                                        struct sk_buff *skb,
 369                                        struct iovec *iv, int len)
 370 {
 371         struct tun_pi pi = { 0, skb->protocol };
 372         ssize_t total = 0;
 373
 374         if (!(tun->flags & TUN_NO_PI)) {
 375                 if ((len -= sizeof(pi)) < 0)
 376                         return -EINVAL;
 377
 378                 if (len < skb->len) {
 379                         /* Packet will be striped */
 380                         pi.flags |= TUN_PKT_STRIP;
 381                 }
 382
 383                 if (memcpy_toiovec(iv, (void *) &pi, sizeof(pi)))
 384                         return -EFAULT;
 385                 total += sizeof(pi);
 386         }
 387
 388         len = min_t(int, skb->len, len);
 389
 390         skb_copy_datagram_iovec(skb, 0, iv, len);
 391         total += len;
 392
 393         tun->dev->stats.tx_packets++;
 394         tun->dev->stats.tx_bytes += len;
 395
 396         return total;
 397 }
 398
 399 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
 400                             unsigned long count, loff_t pos)
 401 {
 402         struct file *file = iocb->ki_filp;
 403         struct tun_struct *tun = file->private_data;
 404         DECLARE_WAITQUEUE(wait, current);
 405         struct sk_buff *skb;
 406         ssize_t len, ret = 0;
 407         DECLARE_MAC_BUF(mac);
 408
 409         if (!tun)
 410                 return -EBADFD;
 411
 412         DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
 413
 414         len = iov_length(iv, count);
 415         if (len < 0)
 416                 return -EINVAL;
 417
 418         add_wait_queue(&tun->read_wait, &wait);
 419         while (len) {
 420                 const u8 ones[ ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
 421                 u8 addr[ ETH_ALEN];
 422                 int bit_nr;
 423
 424                 current->state = TASK_INTERRUPTIBLE;
 425
 426                 /* Read frames from the queue */
 427                 if (!(skb=skb_dequeue(&tun->readq))) {
 428                         if (file->f_flags & O_NONBLOCK) {
 429                                 ret = -EAGAIN;
 430                                 break;
 431                         }
 432                         if (signal_pending(current)) {
 433                                 ret = -ERESTARTSYS;
 434                                 break;
 435                         }
 436
 437                         /* Nothing to read, let's sleep */
 438                         schedule();
 439                         continue;
 440                 }
 441                 netif_wake_queue(tun->dev);
 442
 443                 /** Decide whether to accept this packet. This code is designed to
 444                  * behave identically to an Ethernet interface. Accept the packet if
 445                  * - we are promiscuous.
 446                  * - the packet is addressed to us.
 447                  * - the packet is broadcast.
 448                  * - the packet is multicast and
 449                  *   - we are multicast promiscous.
 450                  *   - we belong to the multicast group.
 451                  */
 452                 skb_copy_from_linear_data(skb, addr, min_t(size_t, sizeof addr,
 453                                                                    skb->len));
 454                 bit_nr = ether_crc(sizeof addr, addr) >> 26;
 455                 if ((tun->if_flags & IFF_PROMISC) ||
 456                                 memcmp(addr, tun->dev_addr, sizeof addr) == 0 ||
 457                                 memcmp(addr, ones, sizeof addr) == 0 ||
 458                                 (((addr[0] == 1 && addr[1] == 0 && addr[2] == 0x5e) ||
 459                                   (addr[0] == 0x33 && addr[1] == 0x33)) &&
 460                                  ((tun->if_flags & IFF_ALLMULTI) ||
 461                                   (tun->chr_filter[bit_nr >> 5] & (1 << (bit_nr & 31)))))) {
 462                         DBG(KERN_DEBUG "%s: tun_chr_readv: accepted: %s\n",
 463                                         tun->dev->name, print_mac(mac, addr));
 464                         ret = tun_put_user(tun, skb, (struct iovec *) iv, len);
 465                         kfree_skb(skb);
 466                         break;
 467                 } else {
 468                         DBG(KERN_DEBUG "%s: tun_chr_readv: rejected: %s\n",
 469                                         tun->dev->name, print_mac(mac, addr));
 470                         kfree_skb(skb);
 471                         continue;
 472                 }
 473         }
 474
 475         current->state = TASK_RUNNING;
 476         remove_wait_queue(&tun->read_wait, &wait);
 477
 478         return ret;
 479 }
 480
 481 static void tun_setup(struct net_device *dev)
 482 {
 483         struct tun_struct *tun = netdev_priv(dev);
 484
 485         skb_queue_head_init(&tun->readq);
 486         init_waitqueue_head(&tun->read_wait);
 487
 488         tun->owner = -1;
 489         tun->group = -1;
 490
 491         dev->open = tun_net_open;
 492         dev->hard_start_xmit = tun_net_xmit;
 493         dev->stop = tun_net_close;
 494         dev->ethtool_ops = &tun_ethtool_ops;
 495         dev->destructor = free_netdev;
 496         dev->features |= NETIF_F_NETNS_LOCAL;
 497 }
 498
 499 static struct tun_struct *tun_get_by_name(struct tun_net *tn, const char *name)
 500 {
 501         struct tun_struct *tun;
 502
 503         ASSERT_RTNL();
 504         list_for_each_entry(tun, &tn->dev_list, list) {
 505                 if (!strncmp(tun->dev->name, name, IFNAMSIZ))
 506                     return tun;
 507         }
 508
 509         return NULL;
 510 }
 511
 512 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
 513 {
 514         struct tun_net *tn;
 515         struct tun_struct *tun;
 516         struct net_device *dev;
 517         int err;
 518
 519         tn = net_generic(net, tun_net_id);
 520         tun = tun_get_by_name(tn, ifr->ifr_name);
 521         if (tun) {
 522                 if (tun->attached)
 523                         return -EBUSY;
 524
 525                 /* Check permissions */
 526                 if (((tun->owner != -1 &&
 527                       current->euid != tun->owner) ||
 528                      (tun->group != -1 &&
 529                       current->egid != tun->group)) &&
 530                      !capable(CAP_NET_ADMIN))
 531                         return -EPERM;
 532         }
 533         else if (__dev_get_by_name(net, ifr->ifr_name))
 534                 return -EINVAL;
 535         else {
 536                 char *name;
 537                 unsigned long flags = 0;
 538
 539                 err = -EINVAL;
 540
 541                 if (!capable(CAP_NET_ADMIN))
 542                         return -EPERM;
 543
 544                 /* Set dev type */
 545                 if (ifr->ifr_flags & IFF_TUN) {
 546                         /* TUN device */
 547                         flags |= TUN_TUN_DEV;
 548                         name = "tun%d";
 549                 } else if (ifr->ifr_flags & IFF_TAP) {
 550                         /* TAP device */
 551                         flags |= TUN_TAP_DEV;
 552                         name = "tap%d";
 553                 } else
 554                         goto failed;
 555
 556                 if (*ifr->ifr_name)
 557                         name = ifr->ifr_name;
 558
 559                 dev = alloc_netdev(sizeof(struct tun_struct), name,
 560                                    tun_setup);
 561                 if (!dev)
 562                         return -ENOMEM;
 563
 564                 dev_net_set(dev, net);
 565                 tun = netdev_priv(dev);
 566                 tun->dev = dev;
 567                 tun->flags = flags;
 568                 /* Be promiscuous by default to maintain previous behaviour. */
 569                 tun->if_flags = IFF_PROMISC;
 570                 /* Generate random Ethernet address. */
 571                 *(__be16 *)tun->dev_addr = htons(0x00FF);
 572                 get_random_bytes(tun->dev_addr + sizeof(u16), 4);
 573                 memset(tun->chr_filter, 0, sizeof tun->chr_filter);
 574
 575                 tun_net_init(dev);
 576
 577                 if (strchr(dev->name, '%')) {
 578                         err = dev_alloc_name(dev, dev->name);
 579                         if (err < 0)
 580                                 goto err_free_dev;
 581                 }
 582
 583                 err = register_netdevice(tun->dev);
 584                 if (err < 0)
 585                         goto err_free_dev;
 586
 587                 list_add(&tun->list, &tn->dev_list);
 588         }
 589
 590         DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
 591
 592         if (ifr->ifr_flags & IFF_NO_PI)
 593                 tun->flags |= TUN_NO_PI;
 594         else
 595                 tun->flags &= ~TUN_NO_PI;
 596
 597         if (ifr->ifr_flags & IFF_ONE_QUEUE)
 598                 tun->flags |= TUN_ONE_QUEUE;
 599         else
 600                 tun->flags &= ~TUN_ONE_QUEUE;
 601
 602         file->private_data = tun;
 603         tun->attached = 1;
 604         get_net(dev_net(tun->dev));
 605
 606         /* Make sure persistent devices do not get stuck in
 607          * xoff state.
 608          */
 609         if (netif_running(tun->dev))
 610                 netif_wake_queue(tun->dev);
 611
 612         strcpy(ifr->ifr_name, tun->dev->name);
 613         return 0;
 614
 615  err_free_dev:
 616         free_netdev(dev);
 617  failed:
 618         return err;
 619 }
 620
 621 static int tun_chr_ioctl(struct inode *inode, struct file *file,
 622                          unsigned int cmd, unsigned long arg)
 623 {
 624         struct tun_struct *tun = file->private_data;
 625         void __user* argp = (void __user*)arg;
 626         struct ifreq ifr;
 627         DECLARE_MAC_BUF(mac);
 628
 629         if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
 630                 if (copy_from_user(&ifr, argp, sizeof ifr))
 631                         return -EFAULT;
 632
 633         if (cmd == TUNSETIFF && !tun) {
 634                 int err;
 635
 636                 ifr.ifr_name[IFNAMSIZ-1] = '\0';
 637
 638                 rtnl_lock();
 639                 err = tun_set_iff(current->nsproxy->net_ns, file, &ifr);
 640                 rtnl_unlock();
 641
 642                 if (err)
 643                         return err;
 644
 645                 if (copy_to_user(argp, &ifr, sizeof(ifr)))
 646                         return -EFAULT;
 647                 return 0;
 648         }
 649
 650         if (!tun)
 651                 return -EBADFD;
 652
 653         DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
 654
 655         switch (cmd) {
 656         case TUNSETNOCSUM:
 657                 /* Disable/Enable checksum */
 658                 if (arg)
 659                         tun->flags |= TUN_NOCHECKSUM;
 660                 else
 661                         tun->flags &= ~TUN_NOCHECKSUM;
 662
 663                 DBG(KERN_INFO "%s: checksum %s\n",
 664                     tun->dev->name, arg ? "disabled" : "enabled");
 665                 break;
 666
 667         case TUNSETPERSIST:
 668                 /* Disable/Enable persist mode */
 669                 if (arg)
 670                         tun->flags |= TUN_PERSIST;
 671                 else
 672                         tun->flags &= ~TUN_PERSIST;
 673
 674                 DBG(KERN_INFO "%s: persist %s\n",
 675                     tun->dev->name, arg ? "enabled" : "disabled");
 676                 break;
 677
 678         case TUNSETOWNER:
 679                 /* Set owner of the device */
 680                 tun->owner = (uid_t) arg;
 681
 682                 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
 683                 break;
 684
 685         case TUNSETGROUP:
 686                 /* Set group of the device */
 687                 tun->group= (gid_t) arg;
 688
 689                 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group);
 690                 break;
 691
 692         case TUNSETLINK:
 693         {
 694                 int ret;
 695
 696                 /* Only allow setting the type when the interface is down */
 697                 rtnl_lock();
 698                 if (tun->dev->flags & IFF_UP) {
 699                         DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
 700                                 tun->dev->name);
 701                         ret = -EBUSY;
 702                 } else {
 703                         tun->dev->type = (int) arg;
 704                         DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
 705                         ret = 0;
 706                 }
 707                 rtnl_unlock();
 708                 return ret;
 709         }
 710
 711 #ifdef TUN_DEBUG
 712         case TUNSETDEBUG:
 713                 tun->debug = arg;
 714                 break;
 715 #endif
 716
 717         case SIOCGIFFLAGS:
 718                 ifr.ifr_flags = tun->if_flags;
 719                 if (copy_to_user( argp, &ifr, sizeof ifr))
 720                         return -EFAULT;
 721                 return 0;
 722
 723         case SIOCSIFFLAGS:
 724                 /** Set the character device's interface flags. Currently only
 725                  * IFF_PROMISC and IFF_ALLMULTI are used. */
 726                 tun->if_flags = ifr.ifr_flags;
 727                 DBG(KERN_INFO "%s: interface flags 0x%lx\n",
 728                                 tun->dev->name, tun->if_flags);
 729                 return 0;
 730
 731         case SIOCGIFHWADDR:
 732                 /* Note: the actual net device's address may be different */
 733                 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev_addr,
 734                                 min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
 735                 if (copy_to_user( argp, &ifr, sizeof ifr))
 736                         return -EFAULT;
 737                 return 0;
 738
 739         case SIOCSIFHWADDR:
 740         {
 741                 /* try to set the actual net device's hw address */
 742                 int ret;
 743
 744                 rtnl_lock();
 745                 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
 746                 rtnl_unlock();
 747
 748                 if (ret == 0) {
 749                         /** Set the character device's hardware address. This is used when
 750                          * filtering packets being sent from the network device to the character
 751                          * device. */
 752                         memcpy(tun->dev_addr, ifr.ifr_hwaddr.sa_data,
 753                                         min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
 754                         DBG(KERN_DEBUG "%s: set hardware address: %x:%x:%x:%x:%x:%x\n",
 755                                         tun->dev->name,
 756                                         tun->dev_addr[0], tun->dev_addr[1], tun->dev_addr[2],
 757                                         tun->dev_addr[3], tun->dev_addr[4], tun->dev_addr[5]);
 758                 }
 759
 760                 return  ret;
 761         }
 762
 763         case SIOCADDMULTI:
 764                 /** Add the specified group to the character device's multicast filter
 765                  * list. */
 766                 rtnl_lock();
 767                 netif_tx_lock_bh(tun->dev);
 768                 add_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
 769                 netif_tx_unlock_bh(tun->dev);
 770                 rtnl_unlock();
 771
 772                 DBG(KERN_DEBUG "%s: add multi: %s\n",
 773                     tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data));
 774                 return 0;
 775
 776         case SIOCDELMULTI:
 777                 /** Remove the specified group from the character device's multicast
 778                  * filter list. */
 779                 rtnl_lock();
 780                 netif_tx_lock_bh(tun->dev);
 781                 del_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
 782                 netif_tx_unlock_bh(tun->dev);
 783                 rtnl_unlock();
 784
 785                 DBG(KERN_DEBUG "%s: del multi: %s\n",
 786                     tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data));
 787                 return 0;
 788
 789         default:
 790                 return -EINVAL;
 791         };
 792
 793         return 0;
 794 }
 795
 796 static int tun_chr_fasync(int fd, struct file *file, int on)
 797 {
 798         struct tun_struct *tun = file->private_data;
 799         int ret;
 800
 801         if (!tun)
 802                 return -EBADFD;
 803
 804         DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
 805
 806         lock_kernel();
 807         if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
 808                 goto out;
 809
 810         if (on) {
 811                 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
 812                 if (ret)
 813                         goto out;
 814                 tun->flags |= TUN_FASYNC;
 815         } else
 816                 tun->flags &= ~TUN_FASYNC;
 817         ret = 0;
 818 out:
 819         unlock_kernel();
 820         return ret;
 821 }
 822
 823 static int tun_chr_open(struct inode *inode, struct file * file)
 824 {
 825         cycle_kernel_lock();
 826         DBG1(KERN_INFO "tunX: tun_chr_open\n");
 827         file->private_data = NULL;
 828         return 0;
 829 }
 830
 831 static int tun_chr_close(struct inode *inode, struct file *file)
 832 {
 833         struct tun_struct *tun = file->private_data;
 834
 835         if (!tun)
 836                 return 0;
 837
 838         DBG(KERN_INFO "%s: tun_chr_close\n", tun->dev->name);
 839
 840         tun_chr_fasync(-1, file, 0);
 841
 842         rtnl_lock();
 843
 844         /* Detach from net device */
 845         file->private_data = NULL;
 846         tun->attached = 0;
 847         put_net(dev_net(tun->dev));
 848
 849         /* Drop read queue */
 850         skb_queue_purge(&tun->readq);
 851
 852         if (!(tun->flags & TUN_PERSIST)) {
 853                 list_del(&tun->list);
 854                 unregister_netdevice(tun->dev);
 855         }
 856
 857         rtnl_unlock();
 858
 859         return 0;
 860 }
 861
 862 static const struct file_operations tun_fops = {
 863         .owner  = THIS_MODULE,
 864         .llseek = no_llseek,
 865         .read  = do_sync_read,
 866         .aio_read  = tun_chr_aio_read,
 867         .write = do_sync_write,
 868         .aio_write = tun_chr_aio_write,
 869         .poll   = tun_chr_poll,
 870         .ioctl  = tun_chr_ioctl,
 871         .open   = tun_chr_open,
 872         .release = tun_chr_close,
 873         .fasync = tun_chr_fasync
 874 };
 875
 876 static struct miscdevice tun_miscdev = {
 877         .minor = TUN_MINOR,
 878         .name = "tun",
 879         .fops = &tun_fops,
 880 };
 881
 882 /* ethtool interface */
 883
 884 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
 885 {
 886         cmd->supported          = 0;
 887         cmd->advertising        = 0;
 888         cmd->speed              = SPEED_10;
 889         cmd->duplex             = DUPLEX_FULL;
 890         cmd->port               = PORT_TP;
 891         cmd->phy_address        = 0;
 892         cmd->transceiver        = XCVR_INTERNAL;
 893         cmd->autoneg            = AUTONEG_DISABLE;
 894         cmd->maxtxpkt           = 0;
 895         cmd->maxrxpkt           = 0;
 896         return 0;
 897 }
 898
 899 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 900 {
 901         struct tun_struct *tun = netdev_priv(dev);
 902
 903         strcpy(info->driver, DRV_NAME);
 904         strcpy(info->version, DRV_VERSION);
 905         strcpy(info->fw_version, "N/A");
 906
 907         switch (tun->flags & TUN_TYPE_MASK) {
 908         case TUN_TUN_DEV:
 909                 strcpy(info->bus_info, "tun");
 910                 break;
 911         case TUN_TAP_DEV:
 912                 strcpy(info->bus_info, "tap");
 913                 break;
 914         }
 915 }
 916
 917 static u32 tun_get_msglevel(struct net_device *dev)
 918 {
 919 #ifdef TUN_DEBUG
 920         struct tun_struct *tun = netdev_priv(dev);
 921         return tun->debug;
 922 #else
 923         return -EOPNOTSUPP;
 924 #endif
 925 }
 926
 927 static void tun_set_msglevel(struct net_device *dev, u32 value)
 928 {
 929 #ifdef TUN_DEBUG
 930         struct tun_struct *tun = netdev_priv(dev);
 931         tun->debug = value;
 932 #endif
 933 }
 934
 935 static u32 tun_get_link(struct net_device *dev)
 936 {
 937         struct tun_struct *tun = netdev_priv(dev);
 938         return tun->attached;
 939 }
 940
 941 static u32 tun_get_rx_csum(struct net_device *dev)
 942 {
 943         struct tun_struct *tun = netdev_priv(dev);
 944         return (tun->flags & TUN_NOCHECKSUM) == 0;
 945 }
 946
 947 static int tun_set_rx_csum(struct net_device *dev, u32 data)
 948 {
 949         struct tun_struct *tun = netdev_priv(dev);
 950         if (data)
 951                 tun->flags &= ~TUN_NOCHECKSUM;
 952         else
 953                 tun->flags |= TUN_NOCHECKSUM;
 954         return 0;
 955 }
 956
 957 static const struct ethtool_ops tun_ethtool_ops = {
 958         .get_settings   = tun_get_settings,
 959         .get_drvinfo    = tun_get_drvinfo,
 960         .get_msglevel   = tun_get_msglevel,
 961         .set_msglevel   = tun_set_msglevel,
 962         .get_link       = tun_get_link,
 963         .get_rx_csum    = tun_get_rx_csum,
 964         .set_rx_csum    = tun_set_rx_csum
 965 };
 966
 967 static int tun_init_net(struct net *net)
 968 {
 969         struct tun_net *tn;
 970
 971         tn = kmalloc(sizeof(*tn), GFP_KERNEL);
 972         if (tn == NULL)
 973                 return -ENOMEM;
 974
 975         INIT_LIST_HEAD(&tn->dev_list);
 976
 977         if (net_assign_generic(net, tun_net_id, tn)) {
 978                 kfree(tn);
 979                 return -ENOMEM;
 980         }
 981
 982         return 0;
 983 }
 984
 985 static void tun_exit_net(struct net *net)
 986 {
 987         struct tun_net *tn;
 988         struct tun_struct *tun, *nxt;
 989
 990         tn = net_generic(net, tun_net_id);
 991
 992         rtnl_lock();
 993         list_for_each_entry_safe(tun, nxt, &tn->dev_list, list) {
 994                 DBG(KERN_INFO "%s cleaned up\n", tun->dev->name);
 995                 unregister_netdevice(tun->dev);
 996         }
 997         rtnl_unlock();
 998
 999         kfree(tn);
1000 }
1001
1002 static struct pernet_operations tun_net_ops = {
1003         .init = tun_init_net,
1004         .exit = tun_exit_net,
1005 };
1006
1007 static int __init tun_init(void)
1008 {
1009         int ret = 0;
1010
1011         printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
1012         printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
1013
1014         ret = register_pernet_gen_device(&tun_net_id, &tun_net_ops);
1015         if (ret) {
1016                 printk(KERN_ERR "tun: Can't register pernet ops\n");
1017                 goto err_pernet;
1018         }
1019
1020         ret = misc_register(&tun_miscdev);
1021         if (ret) {
1022                 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
1023                 goto err_misc;
1024         }
1025         return 0;
1026
1027 err_misc:
1028         unregister_pernet_gen_device(tun_net_id, &tun_net_ops);
1029 err_pernet:
1030         return ret;
1031 }
1032
1033 static void tun_cleanup(void)
1034 {
1035         misc_deregister(&tun_miscdev);
1036         unregister_pernet_gen_device(tun_net_id, &tun_net_ops);
1037 }
1038
1039 module_init(tun_init);
1040 module_exit(tun_cleanup);
1041 MODULE_DESCRIPTION(DRV_DESCRIPTION);
1042 MODULE_AUTHOR(DRV_COPYRIGHT);
1043 MODULE_LICENSE("GPL");
1044 MODULE_ALIAS_MISCDEV(TUN_MINOR);