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 * Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14 22 * Add TUNSETLINK ioctl to set the link encapsulation 23 * 24 * Mark Smith <markzzzsmith@yahoo.com.au> 25 * Use random_ether_addr() for tap MAC address. 26 * 27 * Harald Roelle <harald.roelle@ifi.lmu.de> 2004/04/20 28 * Fixes in packet dropping, queue length setting and queue wakeup. 29 * Increased default tx queue length. 30 * Added ethtool API. 31 * Minor cleanups 32 * 33 * Daniel Podlejski <underley@underley.eu.org> 34 * Modifications for 2.3.99-pre5 kernel. 35 */ 36 37 #define DRV_NAME "tun" 38 #define DRV_VERSION "1.6" 39 #define DRV_DESCRIPTION "Universal TUN/TAP device driver" 40 #define DRV_COPYRIGHT "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>" 41 42 #include <linux/module.h> 43 #include <linux/errno.h> 44 #include <linux/kernel.h> 45 #include <linux/major.h> 46 #include <linux/slab.h> 47 #include <linux/smp_lock.h> 48 #include <linux/poll.h> 49 #include <linux/fcntl.h> 50 #include <linux/init.h> 51 #include <linux/skbuff.h> 52 #include <linux/netdevice.h> 53 #include <linux/etherdevice.h> 54 #include <linux/miscdevice.h> 55 #include <linux/ethtool.h> 56 #include <linux/rtnetlink.h> 57 #include <linux/if.h> 58 #include <linux/if_arp.h> 59 #include <linux/if_ether.h> 60 #include <linux/if_tun.h> 61 #include <linux/crc32.h> 62 #include <linux/nsproxy.h> 63 #include <linux/virtio_net.h> 64 #include <net/net_namespace.h> 65 #include <net/netns/generic.h> 66 #include <net/rtnetlink.h> 67 #include <net/sock.h> 68 69 #include <asm/system.h> 70 #include <asm/uaccess.h> 71 72 /* Uncomment to enable debugging */ 73 /* #define TUN_DEBUG 1 */ 74 75 #ifdef TUN_DEBUG 76 static int debug; 77 78 #define DBG if(tun->debug)printk 79 #define DBG1 if(debug==2)printk 80 #else 81 #define DBG( a... ) 82 #define DBG1( a... ) 83 #endif 84 85 #define FLT_EXACT_COUNT 8 86 struct tap_filter { 87 unsigned int count; /* Number of addrs. Zero means disabled */ 88 u32 mask[2]; /* Mask of the hashed addrs */ 89 unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN]; 90 }; 91 92 struct tun_file { 93 atomic_t count; 94 struct tun_struct *tun; 95 struct net *net; 96 }; 97 98 struct tun_sock; 99 100 struct tun_struct { 101 struct tun_file *tfile; 102 unsigned int flags; 103 uid_t owner; 104 gid_t group; 105 106 struct sk_buff_head readq; 107 108 struct net_device *dev; 109 struct fasync_struct *fasync; 110 111 struct tap_filter txflt; 112 struct sock *sk; 113 struct socket socket; 114 115 #ifdef TUN_DEBUG 116 int debug; 117 #endif 118 }; 119 120 struct tun_sock { 121 struct sock sk; 122 struct tun_struct *tun; 123 }; 124 125 static inline struct tun_sock *tun_sk(struct sock *sk) 126 { 127 return container_of(sk, struct tun_sock, sk); 128 } 129 130 static int tun_attach(struct tun_struct *tun, struct file *file) 131 { 132 struct tun_file *tfile = file->private_data; 133 const struct cred *cred = current_cred(); 134 int err; 135 136 ASSERT_RTNL(); 137 138 /* Check permissions */ 139 if (((tun->owner != -1 && cred->euid != tun->owner) || 140 (tun->group != -1 && !in_egroup_p(tun->group))) && 141 !capable(CAP_NET_ADMIN)) 142 return -EPERM; 143 144 netif_tx_lock_bh(tun->dev); 145 146 err = -EINVAL; 147 if (tfile->tun) 148 goto out; 149 150 err = -EBUSY; 151 if (tun->tfile) 152 goto out; 153 154 err = 0; 155 tfile->tun = tun; 156 tun->tfile = tfile; 157 dev_hold(tun->dev); 158 sock_hold(tun->sk); 159 atomic_inc(&tfile->count); 160 161 out: 162 netif_tx_unlock_bh(tun->dev); 163 return err; 164 } 165 166 static void __tun_detach(struct tun_struct *tun) 167 { 168 /* Detach from net device */ 169 netif_tx_lock_bh(tun->dev); 170 tun->tfile = NULL; 171 netif_tx_unlock_bh(tun->dev); 172 173 /* Drop read queue */ 174 skb_queue_purge(&tun->readq); 175 176 /* Drop the extra count on the net device */ 177 dev_put(tun->dev); 178 } 179 180 static void tun_detach(struct tun_struct *tun) 181 { 182 rtnl_lock(); 183 __tun_detach(tun); 184 rtnl_unlock(); 185 } 186 187 static struct tun_struct *__tun_get(struct tun_file *tfile) 188 { 189 struct tun_struct *tun = NULL; 190 191 if (atomic_inc_not_zero(&tfile->count)) 192 tun = tfile->tun; 193 194 return tun; 195 } 196 197 static struct tun_struct *tun_get(struct file *file) 198 { 199 return __tun_get(file->private_data); 200 } 201 202 static void tun_put(struct tun_struct *tun) 203 { 204 struct tun_file *tfile = tun->tfile; 205 206 if (atomic_dec_and_test(&tfile->count)) 207 tun_detach(tfile->tun); 208 } 209 210 /* TAP filterting */ 211 static void addr_hash_set(u32 *mask, const u8 *addr) 212 { 213 int n = ether_crc(ETH_ALEN, addr) >> 26; 214 mask[n >> 5] |= (1 << (n & 31)); 215 } 216 217 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr) 218 { 219 int n = ether_crc(ETH_ALEN, addr) >> 26; 220 return mask[n >> 5] & (1 << (n & 31)); 221 } 222 223 static int update_filter(struct tap_filter *filter, void __user *arg) 224 { 225 struct { u8 u[ETH_ALEN]; } *addr; 226 struct tun_filter uf; 227 int err, alen, n, nexact; 228 229 if (copy_from_user(&uf, arg, sizeof(uf))) 230 return -EFAULT; 231 232 if (!uf.count) { 233 /* Disabled */ 234 filter->count = 0; 235 return 0; 236 } 237 238 alen = ETH_ALEN * uf.count; 239 addr = kmalloc(alen, GFP_KERNEL); 240 if (!addr) 241 return -ENOMEM; 242 243 if (copy_from_user(addr, arg + sizeof(uf), alen)) { 244 err = -EFAULT; 245 goto done; 246 } 247 248 /* The filter is updated without holding any locks. Which is 249 * perfectly safe. We disable it first and in the worst 250 * case we'll accept a few undesired packets. */ 251 filter->count = 0; 252 wmb(); 253 254 /* Use first set of addresses as an exact filter */ 255 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++) 256 memcpy(filter->addr[n], addr[n].u, ETH_ALEN); 257 258 nexact = n; 259 260 /* Remaining multicast addresses are hashed, 261 * unicast will leave the filter disabled. */ 262 memset(filter->mask, 0, sizeof(filter->mask)); 263 for (; n < uf.count; n++) { 264 if (!is_multicast_ether_addr(addr[n].u)) { 265 err = 0; /* no filter */ 266 goto done; 267 } 268 addr_hash_set(filter->mask, addr[n].u); 269 } 270 271 /* For ALLMULTI just set the mask to all ones. 272 * This overrides the mask populated above. */ 273 if ((uf.flags & TUN_FLT_ALLMULTI)) 274 memset(filter->mask, ~0, sizeof(filter->mask)); 275 276 /* Now enable the filter */ 277 wmb(); 278 filter->count = nexact; 279 280 /* Return the number of exact filters */ 281 err = nexact; 282 283 done: 284 kfree(addr); 285 return err; 286 } 287 288 /* Returns: 0 - drop, !=0 - accept */ 289 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb) 290 { 291 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect 292 * at this point. */ 293 struct ethhdr *eh = (struct ethhdr *) skb->data; 294 int i; 295 296 /* Exact match */ 297 for (i = 0; i < filter->count; i++) 298 if (!compare_ether_addr(eh->h_dest, filter->addr[i])) 299 return 1; 300 301 /* Inexact match (multicast only) */ 302 if (is_multicast_ether_addr(eh->h_dest)) 303 return addr_hash_test(filter->mask, eh->h_dest); 304 305 return 0; 306 } 307 308 /* 309 * Checks whether the packet is accepted or not. 310 * Returns: 0 - drop, !=0 - accept 311 */ 312 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb) 313 { 314 if (!filter->count) 315 return 1; 316 317 return run_filter(filter, skb); 318 } 319 320 /* Network device part of the driver */ 321 322 static const struct ethtool_ops tun_ethtool_ops; 323 324 /* Net device detach from fd. */ 325 static void tun_net_uninit(struct net_device *dev) 326 { 327 struct tun_struct *tun = netdev_priv(dev); 328 struct tun_file *tfile = tun->tfile; 329 330 /* Inform the methods they need to stop using the dev. 331 */ 332 if (tfile) { 333 wake_up_all(&tun->socket.wait); 334 if (atomic_dec_and_test(&tfile->count)) 335 __tun_detach(tun); 336 } 337 } 338 339 static void tun_free_netdev(struct net_device *dev) 340 { 341 struct tun_struct *tun = netdev_priv(dev); 342 343 sock_put(tun->sk); 344 } 345 346 /* Net device open. */ 347 static int tun_net_open(struct net_device *dev) 348 { 349 netif_start_queue(dev); 350 return 0; 351 } 352 353 /* Net device close. */ 354 static int tun_net_close(struct net_device *dev) 355 { 356 netif_stop_queue(dev); 357 return 0; 358 } 359 360 /* Net device start xmit */ 361 static int tun_net_xmit(struct sk_buff *skb, struct net_device *dev) 362 { 363 struct tun_struct *tun = netdev_priv(dev); 364 365 DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len); 366 367 /* Drop packet if interface is not attached */ 368 if (!tun->tfile) 369 goto drop; 370 371 /* Drop if the filter does not like it. 372 * This is a noop if the filter is disabled. 373 * Filter can be enabled only for the TAP devices. */ 374 if (!check_filter(&tun->txflt, skb)) 375 goto drop; 376 377 if (skb_queue_len(&tun->readq) >= dev->tx_queue_len) { 378 if (!(tun->flags & TUN_ONE_QUEUE)) { 379 /* Normal queueing mode. */ 380 /* Packet scheduler handles dropping of further packets. */ 381 netif_stop_queue(dev); 382 383 /* We won't see all dropped packets individually, so overrun 384 * error is more appropriate. */ 385 dev->stats.tx_fifo_errors++; 386 } else { 387 /* Single queue mode. 388 * Driver handles dropping of all packets itself. */ 389 goto drop; 390 } 391 } 392 393 /* Enqueue packet */ 394 skb_queue_tail(&tun->readq, skb); 395 dev->trans_start = jiffies; 396 397 /* Notify and wake up reader process */ 398 if (tun->flags & TUN_FASYNC) 399 kill_fasync(&tun->fasync, SIGIO, POLL_IN); 400 wake_up_interruptible(&tun->socket.wait); 401 return 0; 402 403 drop: 404 dev->stats.tx_dropped++; 405 kfree_skb(skb); 406 return 0; 407 } 408 409 static void tun_net_mclist(struct net_device *dev) 410 { 411 /* 412 * This callback is supposed to deal with mc filter in 413 * _rx_ path and has nothing to do with the _tx_ path. 414 * In rx path we always accept everything userspace gives us. 415 */ 416 return; 417 } 418 419 #define MIN_MTU 68 420 #define MAX_MTU 65535 421 422 static int 423 tun_net_change_mtu(struct net_device *dev, int new_mtu) 424 { 425 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU) 426 return -EINVAL; 427 dev->mtu = new_mtu; 428 return 0; 429 } 430 431 static const struct net_device_ops tun_netdev_ops = { 432 .ndo_uninit = tun_net_uninit, 433 .ndo_open = tun_net_open, 434 .ndo_stop = tun_net_close, 435 .ndo_start_xmit = tun_net_xmit, 436 .ndo_change_mtu = tun_net_change_mtu, 437 }; 438 439 static const struct net_device_ops tap_netdev_ops = { 440 .ndo_uninit = tun_net_uninit, 441 .ndo_open = tun_net_open, 442 .ndo_stop = tun_net_close, 443 .ndo_start_xmit = tun_net_xmit, 444 .ndo_change_mtu = tun_net_change_mtu, 445 .ndo_set_multicast_list = tun_net_mclist, 446 .ndo_set_mac_address = eth_mac_addr, 447 .ndo_validate_addr = eth_validate_addr, 448 }; 449 450 /* Initialize net device. */ 451 static void tun_net_init(struct net_device *dev) 452 { 453 struct tun_struct *tun = netdev_priv(dev); 454 455 switch (tun->flags & TUN_TYPE_MASK) { 456 case TUN_TUN_DEV: 457 dev->netdev_ops = &tun_netdev_ops; 458 459 /* Point-to-Point TUN Device */ 460 dev->hard_header_len = 0; 461 dev->addr_len = 0; 462 dev->mtu = 1500; 463 464 /* Zero header length */ 465 dev->type = ARPHRD_NONE; 466 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 467 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */ 468 break; 469 470 case TUN_TAP_DEV: 471 dev->netdev_ops = &tap_netdev_ops; 472 /* Ethernet TAP Device */ 473 ether_setup(dev); 474 475 random_ether_addr(dev->dev_addr); 476 477 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */ 478 break; 479 } 480 } 481 482 /* Character device part */ 483 484 /* Poll */ 485 static unsigned int tun_chr_poll(struct file *file, poll_table * wait) 486 { 487 struct tun_file *tfile = file->private_data; 488 struct tun_struct *tun = __tun_get(tfile); 489 struct sock *sk = tun->sk; 490 unsigned int mask = 0; 491 492 if (!tun) 493 return POLLERR; 494 495 DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name); 496 497 poll_wait(file, &tun->socket.wait, wait); 498 499 if (!skb_queue_empty(&tun->readq)) 500 mask |= POLLIN | POLLRDNORM; 501 502 if (sock_writeable(sk) || 503 (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) && 504 sock_writeable(sk))) 505 mask |= POLLOUT | POLLWRNORM; 506 507 if (tun->dev->reg_state != NETREG_REGISTERED) 508 mask = POLLERR; 509 510 tun_put(tun); 511 return mask; 512 } 513 514 /* prepad is the amount to reserve at front. len is length after that. 515 * linear is a hint as to how much to copy (usually headers). */ 516 static inline struct sk_buff *tun_alloc_skb(struct tun_struct *tun, 517 size_t prepad, size_t len, 518 size_t linear, int noblock) 519 { 520 struct sock *sk = tun->sk; 521 struct sk_buff *skb; 522 int err; 523 524 /* Under a page? Don't bother with paged skb. */ 525 if (prepad + len < PAGE_SIZE || !linear) 526 linear = len; 527 528 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 529 &err); 530 if (!skb) 531 return ERR_PTR(err); 532 533 skb_reserve(skb, prepad); 534 skb_put(skb, linear); 535 skb->data_len = len - linear; 536 skb->len += len - linear; 537 538 return skb; 539 } 540 541 /* Get packet from user space buffer */ 542 static __inline__ ssize_t tun_get_user(struct tun_struct *tun, 543 const struct iovec *iv, size_t count, 544 int noblock) 545 { 546 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) }; 547 struct sk_buff *skb; 548 size_t len = count, align = 0; 549 struct virtio_net_hdr gso = { 0 }; 550 int offset = 0; 551 552 if (!(tun->flags & TUN_NO_PI)) { 553 if ((len -= sizeof(pi)) > count) 554 return -EINVAL; 555 556 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi))) 557 return -EFAULT; 558 offset += sizeof(pi); 559 } 560 561 if (tun->flags & TUN_VNET_HDR) { 562 if ((len -= sizeof(gso)) > count) 563 return -EINVAL; 564 565 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso))) 566 return -EFAULT; 567 568 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 569 gso.csum_start + gso.csum_offset + 2 > gso.hdr_len) 570 gso.hdr_len = gso.csum_start + gso.csum_offset + 2; 571 572 if (gso.hdr_len > len) 573 return -EINVAL; 574 offset += sizeof(gso); 575 } 576 577 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) { 578 align = NET_IP_ALIGN; 579 if (unlikely(len < ETH_HLEN || 580 (gso.hdr_len && gso.hdr_len < ETH_HLEN))) 581 return -EINVAL; 582 } 583 584 skb = tun_alloc_skb(tun, align, len, gso.hdr_len, noblock); 585 if (IS_ERR(skb)) { 586 if (PTR_ERR(skb) != -EAGAIN) 587 tun->dev->stats.rx_dropped++; 588 return PTR_ERR(skb); 589 } 590 591 if (skb_copy_datagram_from_iovec(skb, 0, iv, offset, len)) { 592 tun->dev->stats.rx_dropped++; 593 kfree_skb(skb); 594 return -EFAULT; 595 } 596 597 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 598 if (!skb_partial_csum_set(skb, gso.csum_start, 599 gso.csum_offset)) { 600 tun->dev->stats.rx_frame_errors++; 601 kfree_skb(skb); 602 return -EINVAL; 603 } 604 } else if (tun->flags & TUN_NOCHECKSUM) 605 skb->ip_summed = CHECKSUM_UNNECESSARY; 606 607 switch (tun->flags & TUN_TYPE_MASK) { 608 case TUN_TUN_DEV: 609 if (tun->flags & TUN_NO_PI) { 610 switch (skb->data[0] & 0xf0) { 611 case 0x40: 612 pi.proto = htons(ETH_P_IP); 613 break; 614 case 0x60: 615 pi.proto = htons(ETH_P_IPV6); 616 break; 617 default: 618 tun->dev->stats.rx_dropped++; 619 kfree_skb(skb); 620 return -EINVAL; 621 } 622 } 623 624 skb_reset_mac_header(skb); 625 skb->protocol = pi.proto; 626 skb->dev = tun->dev; 627 break; 628 case TUN_TAP_DEV: 629 skb->protocol = eth_type_trans(skb, tun->dev); 630 break; 631 }; 632 633 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 634 pr_debug("GSO!\n"); 635 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 636 case VIRTIO_NET_HDR_GSO_TCPV4: 637 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; 638 break; 639 case VIRTIO_NET_HDR_GSO_TCPV6: 640 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; 641 break; 642 default: 643 tun->dev->stats.rx_frame_errors++; 644 kfree_skb(skb); 645 return -EINVAL; 646 } 647 648 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN) 649 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; 650 651 skb_shinfo(skb)->gso_size = gso.gso_size; 652 if (skb_shinfo(skb)->gso_size == 0) { 653 tun->dev->stats.rx_frame_errors++; 654 kfree_skb(skb); 655 return -EINVAL; 656 } 657 658 /* Header must be checked, and gso_segs computed. */ 659 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 660 skb_shinfo(skb)->gso_segs = 0; 661 } 662 663 netif_rx_ni(skb); 664 665 tun->dev->stats.rx_packets++; 666 tun->dev->stats.rx_bytes += len; 667 668 return count; 669 } 670 671 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv, 672 unsigned long count, loff_t pos) 673 { 674 struct file *file = iocb->ki_filp; 675 struct tun_struct *tun = tun_get(file); 676 ssize_t result; 677 678 if (!tun) 679 return -EBADFD; 680 681 DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count); 682 683 result = tun_get_user(tun, iv, iov_length(iv, count), 684 file->f_flags & O_NONBLOCK); 685 686 tun_put(tun); 687 return result; 688 } 689 690 /* Put packet to the user space buffer */ 691 static __inline__ ssize_t tun_put_user(struct tun_struct *tun, 692 struct sk_buff *skb, 693 const struct iovec *iv, int len) 694 { 695 struct tun_pi pi = { 0, skb->protocol }; 696 ssize_t total = 0; 697 698 if (!(tun->flags & TUN_NO_PI)) { 699 if ((len -= sizeof(pi)) < 0) 700 return -EINVAL; 701 702 if (len < skb->len) { 703 /* Packet will be striped */ 704 pi.flags |= TUN_PKT_STRIP; 705 } 706 707 if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi))) 708 return -EFAULT; 709 total += sizeof(pi); 710 } 711 712 if (tun->flags & TUN_VNET_HDR) { 713 struct virtio_net_hdr gso = { 0 }; /* no info leak */ 714 if ((len -= sizeof(gso)) < 0) 715 return -EINVAL; 716 717 if (skb_is_gso(skb)) { 718 struct skb_shared_info *sinfo = skb_shinfo(skb); 719 720 /* This is a hint as to how much should be linear. */ 721 gso.hdr_len = skb_headlen(skb); 722 gso.gso_size = sinfo->gso_size; 723 if (sinfo->gso_type & SKB_GSO_TCPV4) 724 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 725 else if (sinfo->gso_type & SKB_GSO_TCPV6) 726 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 727 else 728 BUG(); 729 if (sinfo->gso_type & SKB_GSO_TCP_ECN) 730 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 731 } else 732 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE; 733 734 if (skb->ip_summed == CHECKSUM_PARTIAL) { 735 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 736 gso.csum_start = skb->csum_start - skb_headroom(skb); 737 gso.csum_offset = skb->csum_offset; 738 } /* else everything is zero */ 739 740 if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total, 741 sizeof(gso)))) 742 return -EFAULT; 743 total += sizeof(gso); 744 } 745 746 len = min_t(int, skb->len, len); 747 748 skb_copy_datagram_const_iovec(skb, 0, iv, total, len); 749 total += len; 750 751 tun->dev->stats.tx_packets++; 752 tun->dev->stats.tx_bytes += len; 753 754 return total; 755 } 756 757 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv, 758 unsigned long count, loff_t pos) 759 { 760 struct file *file = iocb->ki_filp; 761 struct tun_file *tfile = file->private_data; 762 struct tun_struct *tun = __tun_get(tfile); 763 DECLARE_WAITQUEUE(wait, current); 764 struct sk_buff *skb; 765 ssize_t len, ret = 0; 766 767 if (!tun) 768 return -EBADFD; 769 770 DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name); 771 772 len = iov_length(iv, count); 773 if (len < 0) { 774 ret = -EINVAL; 775 goto out; 776 } 777 778 add_wait_queue(&tun->socket.wait, &wait); 779 while (len) { 780 current->state = TASK_INTERRUPTIBLE; 781 782 /* Read frames from the queue */ 783 if (!(skb=skb_dequeue(&tun->readq))) { 784 if (file->f_flags & O_NONBLOCK) { 785 ret = -EAGAIN; 786 break; 787 } 788 if (signal_pending(current)) { 789 ret = -ERESTARTSYS; 790 break; 791 } 792 if (tun->dev->reg_state != NETREG_REGISTERED) { 793 ret = -EIO; 794 break; 795 } 796 797 /* Nothing to read, let's sleep */ 798 schedule(); 799 continue; 800 } 801 netif_wake_queue(tun->dev); 802 803 ret = tun_put_user(tun, skb, iv, len); 804 kfree_skb(skb); 805 break; 806 } 807 808 current->state = TASK_RUNNING; 809 remove_wait_queue(&tun->socket.wait, &wait); 810 811 out: 812 tun_put(tun); 813 return ret; 814 } 815 816 static void tun_setup(struct net_device *dev) 817 { 818 struct tun_struct *tun = netdev_priv(dev); 819 820 skb_queue_head_init(&tun->readq); 821 822 tun->owner = -1; 823 tun->group = -1; 824 825 dev->ethtool_ops = &tun_ethtool_ops; 826 dev->destructor = tun_free_netdev; 827 } 828 829 /* Trivial set of netlink ops to allow deleting tun or tap 830 * device with netlink. 831 */ 832 static int tun_validate(struct nlattr *tb[], struct nlattr *data[]) 833 { 834 return -EINVAL; 835 } 836 837 static struct rtnl_link_ops tun_link_ops __read_mostly = { 838 .kind = DRV_NAME, 839 .priv_size = sizeof(struct tun_struct), 840 .setup = tun_setup, 841 .validate = tun_validate, 842 }; 843 844 static void tun_sock_write_space(struct sock *sk) 845 { 846 struct tun_struct *tun; 847 848 if (!sock_writeable(sk)) 849 return; 850 851 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags)) 852 return; 853 854 if (sk->sk_sleep && waitqueue_active(sk->sk_sleep)) 855 wake_up_interruptible_sync(sk->sk_sleep); 856 857 tun = container_of(sk, struct tun_sock, sk)->tun; 858 kill_fasync(&tun->fasync, SIGIO, POLL_OUT); 859 } 860 861 static void tun_sock_destruct(struct sock *sk) 862 { 863 free_netdev(container_of(sk, struct tun_sock, sk)->tun->dev); 864 } 865 866 static struct proto tun_proto = { 867 .name = "tun", 868 .owner = THIS_MODULE, 869 .obj_size = sizeof(struct tun_sock), 870 }; 871 872 static int tun_flags(struct tun_struct *tun) 873 { 874 int flags = 0; 875 876 if (tun->flags & TUN_TUN_DEV) 877 flags |= IFF_TUN; 878 else 879 flags |= IFF_TAP; 880 881 if (tun->flags & TUN_NO_PI) 882 flags |= IFF_NO_PI; 883 884 if (tun->flags & TUN_ONE_QUEUE) 885 flags |= IFF_ONE_QUEUE; 886 887 if (tun->flags & TUN_VNET_HDR) 888 flags |= IFF_VNET_HDR; 889 890 return flags; 891 } 892 893 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr, 894 char *buf) 895 { 896 struct tun_struct *tun = netdev_priv(to_net_dev(dev)); 897 return sprintf(buf, "0x%x\n", tun_flags(tun)); 898 } 899 900 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr, 901 char *buf) 902 { 903 struct tun_struct *tun = netdev_priv(to_net_dev(dev)); 904 return sprintf(buf, "%d\n", tun->owner); 905 } 906 907 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr, 908 char *buf) 909 { 910 struct tun_struct *tun = netdev_priv(to_net_dev(dev)); 911 return sprintf(buf, "%d\n", tun->group); 912 } 913 914 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL); 915 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL); 916 static DEVICE_ATTR(group, 0444, tun_show_group, NULL); 917 918 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) 919 { 920 struct sock *sk; 921 struct tun_struct *tun; 922 struct net_device *dev; 923 int err; 924 925 dev = __dev_get_by_name(net, ifr->ifr_name); 926 if (dev) { 927 if (ifr->ifr_flags & IFF_TUN_EXCL) 928 return -EBUSY; 929 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops) 930 tun = netdev_priv(dev); 931 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops) 932 tun = netdev_priv(dev); 933 else 934 return -EINVAL; 935 936 err = tun_attach(tun, file); 937 if (err < 0) 938 return err; 939 } 940 else { 941 char *name; 942 unsigned long flags = 0; 943 944 err = -EINVAL; 945 946 if (!capable(CAP_NET_ADMIN)) 947 return -EPERM; 948 949 /* Set dev type */ 950 if (ifr->ifr_flags & IFF_TUN) { 951 /* TUN device */ 952 flags |= TUN_TUN_DEV; 953 name = "tun%d"; 954 } else if (ifr->ifr_flags & IFF_TAP) { 955 /* TAP device */ 956 flags |= TUN_TAP_DEV; 957 name = "tap%d"; 958 } else 959 goto failed; 960 961 if (*ifr->ifr_name) 962 name = ifr->ifr_name; 963 964 dev = alloc_netdev(sizeof(struct tun_struct), name, 965 tun_setup); 966 if (!dev) 967 return -ENOMEM; 968 969 dev_net_set(dev, net); 970 dev->rtnl_link_ops = &tun_link_ops; 971 972 tun = netdev_priv(dev); 973 tun->dev = dev; 974 tun->flags = flags; 975 tun->txflt.count = 0; 976 977 err = -ENOMEM; 978 sk = sk_alloc(net, AF_UNSPEC, GFP_KERNEL, &tun_proto); 979 if (!sk) 980 goto err_free_dev; 981 982 init_waitqueue_head(&tun->socket.wait); 983 sock_init_data(&tun->socket, sk); 984 sk->sk_write_space = tun_sock_write_space; 985 sk->sk_sndbuf = INT_MAX; 986 987 tun->sk = sk; 988 container_of(sk, struct tun_sock, sk)->tun = tun; 989 990 tun_net_init(dev); 991 992 if (strchr(dev->name, '%')) { 993 err = dev_alloc_name(dev, dev->name); 994 if (err < 0) 995 goto err_free_sk; 996 } 997 998 err = -EINVAL; 999 err = register_netdevice(tun->dev); 1000 if (err < 0) 1001 goto err_free_sk; 1002 1003 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) || 1004 device_create_file(&tun->dev->dev, &dev_attr_owner) || 1005 device_create_file(&tun->dev->dev, &dev_attr_group)) 1006 printk(KERN_ERR "Failed to create tun sysfs files\n"); 1007 1008 sk->sk_destruct = tun_sock_destruct; 1009 1010 err = tun_attach(tun, file); 1011 if (err < 0) 1012 goto failed; 1013 } 1014 1015 DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name); 1016 1017 if (ifr->ifr_flags & IFF_NO_PI) 1018 tun->flags |= TUN_NO_PI; 1019 else 1020 tun->flags &= ~TUN_NO_PI; 1021 1022 if (ifr->ifr_flags & IFF_ONE_QUEUE) 1023 tun->flags |= TUN_ONE_QUEUE; 1024 else 1025 tun->flags &= ~TUN_ONE_QUEUE; 1026 1027 if (ifr->ifr_flags & IFF_VNET_HDR) 1028 tun->flags |= TUN_VNET_HDR; 1029 else 1030 tun->flags &= ~TUN_VNET_HDR; 1031 1032 /* Make sure persistent devices do not get stuck in 1033 * xoff state. 1034 */ 1035 if (netif_running(tun->dev)) 1036 netif_wake_queue(tun->dev); 1037 1038 strcpy(ifr->ifr_name, tun->dev->name); 1039 return 0; 1040 1041 err_free_sk: 1042 sock_put(sk); 1043 err_free_dev: 1044 free_netdev(dev); 1045 failed: 1046 return err; 1047 } 1048 1049 static int tun_get_iff(struct net *net, struct file *file, struct ifreq *ifr) 1050 { 1051 struct tun_struct *tun = tun_get(file); 1052 1053 if (!tun) 1054 return -EBADFD; 1055 1056 DBG(KERN_INFO "%s: tun_get_iff\n", tun->dev->name); 1057 1058 strcpy(ifr->ifr_name, tun->dev->name); 1059 1060 ifr->ifr_flags = tun_flags(tun); 1061 1062 tun_put(tun); 1063 return 0; 1064 } 1065 1066 /* This is like a cut-down ethtool ops, except done via tun fd so no 1067 * privs required. */ 1068 static int set_offload(struct net_device *dev, unsigned long arg) 1069 { 1070 unsigned int old_features, features; 1071 1072 old_features = dev->features; 1073 /* Unset features, set them as we chew on the arg. */ 1074 features = (old_features & ~(NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST 1075 |NETIF_F_TSO_ECN|NETIF_F_TSO|NETIF_F_TSO6)); 1076 1077 if (arg & TUN_F_CSUM) { 1078 features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; 1079 arg &= ~TUN_F_CSUM; 1080 1081 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) { 1082 if (arg & TUN_F_TSO_ECN) { 1083 features |= NETIF_F_TSO_ECN; 1084 arg &= ~TUN_F_TSO_ECN; 1085 } 1086 if (arg & TUN_F_TSO4) 1087 features |= NETIF_F_TSO; 1088 if (arg & TUN_F_TSO6) 1089 features |= NETIF_F_TSO6; 1090 arg &= ~(TUN_F_TSO4|TUN_F_TSO6); 1091 } 1092 } 1093 1094 /* This gives the user a way to test for new features in future by 1095 * trying to set them. */ 1096 if (arg) 1097 return -EINVAL; 1098 1099 dev->features = features; 1100 if (old_features != dev->features) 1101 netdev_features_change(dev); 1102 1103 return 0; 1104 } 1105 1106 static int tun_chr_ioctl(struct inode *inode, struct file *file, 1107 unsigned int cmd, unsigned long arg) 1108 { 1109 struct tun_file *tfile = file->private_data; 1110 struct tun_struct *tun; 1111 void __user* argp = (void __user*)arg; 1112 struct ifreq ifr; 1113 int sndbuf; 1114 int ret; 1115 1116 if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89) 1117 if (copy_from_user(&ifr, argp, sizeof ifr)) 1118 return -EFAULT; 1119 1120 if (cmd == TUNGETFEATURES) { 1121 /* Currently this just means: "what IFF flags are valid?". 1122 * This is needed because we never checked for invalid flags on 1123 * TUNSETIFF. */ 1124 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE | 1125 IFF_VNET_HDR, 1126 (unsigned int __user*)argp); 1127 } 1128 1129 tun = __tun_get(tfile); 1130 if (cmd == TUNSETIFF && !tun) { 1131 int err; 1132 1133 ifr.ifr_name[IFNAMSIZ-1] = '\0'; 1134 1135 rtnl_lock(); 1136 err = tun_set_iff(tfile->net, file, &ifr); 1137 rtnl_unlock(); 1138 1139 if (err) 1140 return err; 1141 1142 if (copy_to_user(argp, &ifr, sizeof(ifr))) 1143 return -EFAULT; 1144 return 0; 1145 } 1146 1147 1148 if (!tun) 1149 return -EBADFD; 1150 1151 DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd); 1152 1153 ret = 0; 1154 switch (cmd) { 1155 case TUNGETIFF: 1156 ret = tun_get_iff(current->nsproxy->net_ns, file, &ifr); 1157 if (ret) 1158 break; 1159 1160 if (copy_to_user(argp, &ifr, sizeof(ifr))) 1161 ret = -EFAULT; 1162 break; 1163 1164 case TUNSETNOCSUM: 1165 /* Disable/Enable checksum */ 1166 if (arg) 1167 tun->flags |= TUN_NOCHECKSUM; 1168 else 1169 tun->flags &= ~TUN_NOCHECKSUM; 1170 1171 DBG(KERN_INFO "%s: checksum %s\n", 1172 tun->dev->name, arg ? "disabled" : "enabled"); 1173 break; 1174 1175 case TUNSETPERSIST: 1176 /* Disable/Enable persist mode */ 1177 if (arg) 1178 tun->flags |= TUN_PERSIST; 1179 else 1180 tun->flags &= ~TUN_PERSIST; 1181 1182 DBG(KERN_INFO "%s: persist %s\n", 1183 tun->dev->name, arg ? "enabled" : "disabled"); 1184 break; 1185 1186 case TUNSETOWNER: 1187 /* Set owner of the device */ 1188 tun->owner = (uid_t) arg; 1189 1190 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner); 1191 break; 1192 1193 case TUNSETGROUP: 1194 /* Set group of the device */ 1195 tun->group= (gid_t) arg; 1196 1197 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group); 1198 break; 1199 1200 case TUNSETLINK: 1201 /* Only allow setting the type when the interface is down */ 1202 rtnl_lock(); 1203 if (tun->dev->flags & IFF_UP) { 1204 DBG(KERN_INFO "%s: Linktype set failed because interface is up\n", 1205 tun->dev->name); 1206 ret = -EBUSY; 1207 } else { 1208 tun->dev->type = (int) arg; 1209 DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type); 1210 ret = 0; 1211 } 1212 rtnl_unlock(); 1213 break; 1214 1215 #ifdef TUN_DEBUG 1216 case TUNSETDEBUG: 1217 tun->debug = arg; 1218 break; 1219 #endif 1220 case TUNSETOFFLOAD: 1221 rtnl_lock(); 1222 ret = set_offload(tun->dev, arg); 1223 rtnl_unlock(); 1224 break; 1225 1226 case TUNSETTXFILTER: 1227 /* Can be set only for TAPs */ 1228 ret = -EINVAL; 1229 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV) 1230 break; 1231 rtnl_lock(); 1232 ret = update_filter(&tun->txflt, (void __user *)arg); 1233 rtnl_unlock(); 1234 break; 1235 1236 case SIOCGIFHWADDR: 1237 /* Get hw addres */ 1238 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN); 1239 ifr.ifr_hwaddr.sa_family = tun->dev->type; 1240 if (copy_to_user(argp, &ifr, sizeof ifr)) 1241 ret = -EFAULT; 1242 break; 1243 1244 case SIOCSIFHWADDR: 1245 /* Set hw address */ 1246 DBG(KERN_DEBUG "%s: set hw address: %pM\n", 1247 tun->dev->name, ifr.ifr_hwaddr.sa_data); 1248 1249 rtnl_lock(); 1250 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr); 1251 rtnl_unlock(); 1252 break; 1253 1254 case TUNGETSNDBUF: 1255 sndbuf = tun->sk->sk_sndbuf; 1256 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf))) 1257 ret = -EFAULT; 1258 break; 1259 1260 case TUNSETSNDBUF: 1261 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) { 1262 ret = -EFAULT; 1263 break; 1264 } 1265 1266 tun->sk->sk_sndbuf = sndbuf; 1267 break; 1268 1269 default: 1270 ret = -EINVAL; 1271 break; 1272 }; 1273 1274 tun_put(tun); 1275 return ret; 1276 } 1277 1278 static int tun_chr_fasync(int fd, struct file *file, int on) 1279 { 1280 struct tun_struct *tun = tun_get(file); 1281 int ret; 1282 1283 if (!tun) 1284 return -EBADFD; 1285 1286 DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on); 1287 1288 lock_kernel(); 1289 if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0) 1290 goto out; 1291 1292 if (on) { 1293 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0); 1294 if (ret) 1295 goto out; 1296 tun->flags |= TUN_FASYNC; 1297 } else 1298 tun->flags &= ~TUN_FASYNC; 1299 ret = 0; 1300 out: 1301 unlock_kernel(); 1302 tun_put(tun); 1303 return ret; 1304 } 1305 1306 static int tun_chr_open(struct inode *inode, struct file * file) 1307 { 1308 struct tun_file *tfile; 1309 cycle_kernel_lock(); 1310 DBG1(KERN_INFO "tunX: tun_chr_open\n"); 1311 1312 tfile = kmalloc(sizeof(*tfile), GFP_KERNEL); 1313 if (!tfile) 1314 return -ENOMEM; 1315 atomic_set(&tfile->count, 0); 1316 tfile->tun = NULL; 1317 tfile->net = get_net(current->nsproxy->net_ns); 1318 file->private_data = tfile; 1319 return 0; 1320 } 1321 1322 static int tun_chr_close(struct inode *inode, struct file *file) 1323 { 1324 struct tun_file *tfile = file->private_data; 1325 struct tun_struct *tun; 1326 1327 1328 rtnl_lock(); 1329 tun = __tun_get(tfile); 1330 if (tun) { 1331 DBG(KERN_INFO "%s: tun_chr_close\n", tun->dev->name); 1332 1333 __tun_detach(tun); 1334 1335 /* If desireable, unregister the netdevice. */ 1336 if (!(tun->flags & TUN_PERSIST)) 1337 unregister_netdevice(tun->dev); 1338 1339 } 1340 rtnl_unlock(); 1341 1342 tun = tfile->tun; 1343 if (tun) 1344 sock_put(tun->sk); 1345 1346 put_net(tfile->net); 1347 kfree(tfile); 1348 1349 return 0; 1350 } 1351 1352 static const struct file_operations tun_fops = { 1353 .owner = THIS_MODULE, 1354 .llseek = no_llseek, 1355 .read = do_sync_read, 1356 .aio_read = tun_chr_aio_read, 1357 .write = do_sync_write, 1358 .aio_write = tun_chr_aio_write, 1359 .poll = tun_chr_poll, 1360 .ioctl = tun_chr_ioctl, 1361 .open = tun_chr_open, 1362 .release = tun_chr_close, 1363 .fasync = tun_chr_fasync 1364 }; 1365 1366 static struct miscdevice tun_miscdev = { 1367 .minor = TUN_MINOR, 1368 .name = "tun", 1369 .fops = &tun_fops, 1370 }; 1371 1372 /* ethtool interface */ 1373 1374 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd) 1375 { 1376 cmd->supported = 0; 1377 cmd->advertising = 0; 1378 cmd->speed = SPEED_10; 1379 cmd->duplex = DUPLEX_FULL; 1380 cmd->port = PORT_TP; 1381 cmd->phy_address = 0; 1382 cmd->transceiver = XCVR_INTERNAL; 1383 cmd->autoneg = AUTONEG_DISABLE; 1384 cmd->maxtxpkt = 0; 1385 cmd->maxrxpkt = 0; 1386 return 0; 1387 } 1388 1389 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info) 1390 { 1391 struct tun_struct *tun = netdev_priv(dev); 1392 1393 strcpy(info->driver, DRV_NAME); 1394 strcpy(info->version, DRV_VERSION); 1395 strcpy(info->fw_version, "N/A"); 1396 1397 switch (tun->flags & TUN_TYPE_MASK) { 1398 case TUN_TUN_DEV: 1399 strcpy(info->bus_info, "tun"); 1400 break; 1401 case TUN_TAP_DEV: 1402 strcpy(info->bus_info, "tap"); 1403 break; 1404 } 1405 } 1406 1407 static u32 tun_get_msglevel(struct net_device *dev) 1408 { 1409 #ifdef TUN_DEBUG 1410 struct tun_struct *tun = netdev_priv(dev); 1411 return tun->debug; 1412 #else 1413 return -EOPNOTSUPP; 1414 #endif 1415 } 1416 1417 static void tun_set_msglevel(struct net_device *dev, u32 value) 1418 { 1419 #ifdef TUN_DEBUG 1420 struct tun_struct *tun = netdev_priv(dev); 1421 tun->debug = value; 1422 #endif 1423 } 1424 1425 static u32 tun_get_link(struct net_device *dev) 1426 { 1427 struct tun_struct *tun = netdev_priv(dev); 1428 return !!tun->tfile; 1429 } 1430 1431 static u32 tun_get_rx_csum(struct net_device *dev) 1432 { 1433 struct tun_struct *tun = netdev_priv(dev); 1434 return (tun->flags & TUN_NOCHECKSUM) == 0; 1435 } 1436 1437 static int tun_set_rx_csum(struct net_device *dev, u32 data) 1438 { 1439 struct tun_struct *tun = netdev_priv(dev); 1440 if (data) 1441 tun->flags &= ~TUN_NOCHECKSUM; 1442 else 1443 tun->flags |= TUN_NOCHECKSUM; 1444 return 0; 1445 } 1446 1447 static const struct ethtool_ops tun_ethtool_ops = { 1448 .get_settings = tun_get_settings, 1449 .get_drvinfo = tun_get_drvinfo, 1450 .get_msglevel = tun_get_msglevel, 1451 .set_msglevel = tun_set_msglevel, 1452 .get_link = tun_get_link, 1453 .get_rx_csum = tun_get_rx_csum, 1454 .set_rx_csum = tun_set_rx_csum 1455 }; 1456 1457 1458 static int __init tun_init(void) 1459 { 1460 int ret = 0; 1461 1462 printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION); 1463 printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT); 1464 1465 ret = rtnl_link_register(&tun_link_ops); 1466 if (ret) { 1467 printk(KERN_ERR "tun: Can't register link_ops\n"); 1468 goto err_linkops; 1469 } 1470 1471 ret = misc_register(&tun_miscdev); 1472 if (ret) { 1473 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR); 1474 goto err_misc; 1475 } 1476 return 0; 1477 err_misc: 1478 rtnl_link_unregister(&tun_link_ops); 1479 err_linkops: 1480 return ret; 1481 } 1482 1483 static void tun_cleanup(void) 1484 { 1485 misc_deregister(&tun_miscdev); 1486 rtnl_link_unregister(&tun_link_ops); 1487 } 1488 1489 module_init(tun_init); 1490 module_exit(tun_cleanup); 1491 MODULE_DESCRIPTION(DRV_DESCRIPTION); 1492 MODULE_AUTHOR(DRV_COPYRIGHT); 1493 MODULE_LICENSE("GPL"); 1494 MODULE_ALIAS_MISCDEV(TUN_MINOR); 1495