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 pr_fmt(fmt) KBUILD_MODNAME ": " fmt 38 39 #define DRV_NAME "tun" 40 #define DRV_VERSION "1.6" 41 #define DRV_DESCRIPTION "Universal TUN/TAP device driver" 42 #define DRV_COPYRIGHT "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>" 43 44 #include <linux/module.h> 45 #include <linux/errno.h> 46 #include <linux/kernel.h> 47 #include <linux/major.h> 48 #include <linux/slab.h> 49 #include <linux/poll.h> 50 #include <linux/fcntl.h> 51 #include <linux/init.h> 52 #include <linux/skbuff.h> 53 #include <linux/netdevice.h> 54 #include <linux/etherdevice.h> 55 #include <linux/miscdevice.h> 56 #include <linux/ethtool.h> 57 #include <linux/rtnetlink.h> 58 #include <linux/compat.h> 59 #include <linux/if.h> 60 #include <linux/if_arp.h> 61 #include <linux/if_ether.h> 62 #include <linux/if_tun.h> 63 #include <linux/crc32.h> 64 #include <linux/nsproxy.h> 65 #include <linux/virtio_net.h> 66 #include <linux/rcupdate.h> 67 #include <net/net_namespace.h> 68 #include <net/netns/generic.h> 69 #include <net/rtnetlink.h> 70 #include <net/sock.h> 71 72 #include <asm/system.h> 73 #include <asm/uaccess.h> 74 75 /* Uncomment to enable debugging */ 76 /* #define TUN_DEBUG 1 */ 77 78 #ifdef TUN_DEBUG 79 static int debug; 80 81 #define tun_debug(level, tun, fmt, args...) \ 82 do { \ 83 if (tun->debug) \ 84 netdev_printk(level, tun->dev, fmt, ##args); \ 85 } while (0) 86 #define DBG1(level, fmt, args...) \ 87 do { \ 88 if (debug == 2) \ 89 printk(level fmt, ##args); \ 90 } while (0) 91 #else 92 #define tun_debug(level, tun, fmt, args...) \ 93 do { \ 94 if (0) \ 95 netdev_printk(level, tun->dev, fmt, ##args); \ 96 } while (0) 97 #define DBG1(level, fmt, args...) \ 98 do { \ 99 if (0) \ 100 printk(level fmt, ##args); \ 101 } while (0) 102 #endif 103 104 #define FLT_EXACT_COUNT 8 105 struct tap_filter { 106 unsigned int count; /* Number of addrs. Zero means disabled */ 107 u32 mask[2]; /* Mask of the hashed addrs */ 108 unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN]; 109 }; 110 111 struct tun_file { 112 atomic_t count; 113 struct tun_struct *tun; 114 struct net *net; 115 }; 116 117 struct tun_sock; 118 119 struct tun_struct { 120 struct tun_file *tfile; 121 unsigned int flags; 122 uid_t owner; 123 gid_t group; 124 125 struct net_device *dev; 126 u32 set_features; 127 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \ 128 NETIF_F_TSO6|NETIF_F_UFO) 129 struct fasync_struct *fasync; 130 131 struct tap_filter txflt; 132 struct socket socket; 133 struct socket_wq wq; 134 135 int vnet_hdr_sz; 136 137 #ifdef TUN_DEBUG 138 int debug; 139 #endif 140 }; 141 142 struct tun_sock { 143 struct sock sk; 144 struct tun_struct *tun; 145 }; 146 147 static inline struct tun_sock *tun_sk(struct sock *sk) 148 { 149 return container_of(sk, struct tun_sock, sk); 150 } 151 152 static int tun_attach(struct tun_struct *tun, struct file *file) 153 { 154 struct tun_file *tfile = file->private_data; 155 int err; 156 157 ASSERT_RTNL(); 158 159 netif_tx_lock_bh(tun->dev); 160 161 err = -EINVAL; 162 if (tfile->tun) 163 goto out; 164 165 err = -EBUSY; 166 if (tun->tfile) 167 goto out; 168 169 err = 0; 170 tfile->tun = tun; 171 tun->tfile = tfile; 172 tun->socket.file = file; 173 netif_carrier_on(tun->dev); 174 dev_hold(tun->dev); 175 sock_hold(tun->socket.sk); 176 atomic_inc(&tfile->count); 177 178 out: 179 netif_tx_unlock_bh(tun->dev); 180 return err; 181 } 182 183 static void __tun_detach(struct tun_struct *tun) 184 { 185 /* Detach from net device */ 186 netif_tx_lock_bh(tun->dev); 187 netif_carrier_off(tun->dev); 188 tun->tfile = NULL; 189 tun->socket.file = NULL; 190 netif_tx_unlock_bh(tun->dev); 191 192 /* Drop read queue */ 193 skb_queue_purge(&tun->socket.sk->sk_receive_queue); 194 195 /* Drop the extra count on the net device */ 196 dev_put(tun->dev); 197 } 198 199 static void tun_detach(struct tun_struct *tun) 200 { 201 rtnl_lock(); 202 __tun_detach(tun); 203 rtnl_unlock(); 204 } 205 206 static struct tun_struct *__tun_get(struct tun_file *tfile) 207 { 208 struct tun_struct *tun = NULL; 209 210 if (atomic_inc_not_zero(&tfile->count)) 211 tun = tfile->tun; 212 213 return tun; 214 } 215 216 static struct tun_struct *tun_get(struct file *file) 217 { 218 return __tun_get(file->private_data); 219 } 220 221 static void tun_put(struct tun_struct *tun) 222 { 223 struct tun_file *tfile = tun->tfile; 224 225 if (atomic_dec_and_test(&tfile->count)) 226 tun_detach(tfile->tun); 227 } 228 229 /* TAP filtering */ 230 static void addr_hash_set(u32 *mask, const u8 *addr) 231 { 232 int n = ether_crc(ETH_ALEN, addr) >> 26; 233 mask[n >> 5] |= (1 << (n & 31)); 234 } 235 236 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr) 237 { 238 int n = ether_crc(ETH_ALEN, addr) >> 26; 239 return mask[n >> 5] & (1 << (n & 31)); 240 } 241 242 static int update_filter(struct tap_filter *filter, void __user *arg) 243 { 244 struct { u8 u[ETH_ALEN]; } *addr; 245 struct tun_filter uf; 246 int err, alen, n, nexact; 247 248 if (copy_from_user(&uf, arg, sizeof(uf))) 249 return -EFAULT; 250 251 if (!uf.count) { 252 /* Disabled */ 253 filter->count = 0; 254 return 0; 255 } 256 257 alen = ETH_ALEN * uf.count; 258 addr = kmalloc(alen, GFP_KERNEL); 259 if (!addr) 260 return -ENOMEM; 261 262 if (copy_from_user(addr, arg + sizeof(uf), alen)) { 263 err = -EFAULT; 264 goto done; 265 } 266 267 /* The filter is updated without holding any locks. Which is 268 * perfectly safe. We disable it first and in the worst 269 * case we'll accept a few undesired packets. */ 270 filter->count = 0; 271 wmb(); 272 273 /* Use first set of addresses as an exact filter */ 274 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++) 275 memcpy(filter->addr[n], addr[n].u, ETH_ALEN); 276 277 nexact = n; 278 279 /* Remaining multicast addresses are hashed, 280 * unicast will leave the filter disabled. */ 281 memset(filter->mask, 0, sizeof(filter->mask)); 282 for (; n < uf.count; n++) { 283 if (!is_multicast_ether_addr(addr[n].u)) { 284 err = 0; /* no filter */ 285 goto done; 286 } 287 addr_hash_set(filter->mask, addr[n].u); 288 } 289 290 /* For ALLMULTI just set the mask to all ones. 291 * This overrides the mask populated above. */ 292 if ((uf.flags & TUN_FLT_ALLMULTI)) 293 memset(filter->mask, ~0, sizeof(filter->mask)); 294 295 /* Now enable the filter */ 296 wmb(); 297 filter->count = nexact; 298 299 /* Return the number of exact filters */ 300 err = nexact; 301 302 done: 303 kfree(addr); 304 return err; 305 } 306 307 /* Returns: 0 - drop, !=0 - accept */ 308 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb) 309 { 310 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect 311 * at this point. */ 312 struct ethhdr *eh = (struct ethhdr *) skb->data; 313 int i; 314 315 /* Exact match */ 316 for (i = 0; i < filter->count; i++) 317 if (!compare_ether_addr(eh->h_dest, filter->addr[i])) 318 return 1; 319 320 /* Inexact match (multicast only) */ 321 if (is_multicast_ether_addr(eh->h_dest)) 322 return addr_hash_test(filter->mask, eh->h_dest); 323 324 return 0; 325 } 326 327 /* 328 * Checks whether the packet is accepted or not. 329 * Returns: 0 - drop, !=0 - accept 330 */ 331 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb) 332 { 333 if (!filter->count) 334 return 1; 335 336 return run_filter(filter, skb); 337 } 338 339 /* Network device part of the driver */ 340 341 static const struct ethtool_ops tun_ethtool_ops; 342 343 /* Net device detach from fd. */ 344 static void tun_net_uninit(struct net_device *dev) 345 { 346 struct tun_struct *tun = netdev_priv(dev); 347 struct tun_file *tfile = tun->tfile; 348 349 /* Inform the methods they need to stop using the dev. 350 */ 351 if (tfile) { 352 wake_up_all(&tun->wq.wait); 353 if (atomic_dec_and_test(&tfile->count)) 354 __tun_detach(tun); 355 } 356 } 357 358 static void tun_free_netdev(struct net_device *dev) 359 { 360 struct tun_struct *tun = netdev_priv(dev); 361 362 sock_put(tun->socket.sk); 363 } 364 365 /* Net device open. */ 366 static int tun_net_open(struct net_device *dev) 367 { 368 netif_start_queue(dev); 369 return 0; 370 } 371 372 /* Net device close. */ 373 static int tun_net_close(struct net_device *dev) 374 { 375 netif_stop_queue(dev); 376 return 0; 377 } 378 379 /* Net device start xmit */ 380 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev) 381 { 382 struct tun_struct *tun = netdev_priv(dev); 383 384 tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len); 385 386 /* Drop packet if interface is not attached */ 387 if (!tun->tfile) 388 goto drop; 389 390 /* Drop if the filter does not like it. 391 * This is a noop if the filter is disabled. 392 * Filter can be enabled only for the TAP devices. */ 393 if (!check_filter(&tun->txflt, skb)) 394 goto drop; 395 396 if (tun->socket.sk->sk_filter && 397 sk_filter(tun->socket.sk, skb)) 398 goto drop; 399 400 if (skb_queue_len(&tun->socket.sk->sk_receive_queue) >= dev->tx_queue_len) { 401 if (!(tun->flags & TUN_ONE_QUEUE)) { 402 /* Normal queueing mode. */ 403 /* Packet scheduler handles dropping of further packets. */ 404 netif_stop_queue(dev); 405 406 /* We won't see all dropped packets individually, so overrun 407 * error is more appropriate. */ 408 dev->stats.tx_fifo_errors++; 409 } else { 410 /* Single queue mode. 411 * Driver handles dropping of all packets itself. */ 412 goto drop; 413 } 414 } 415 416 /* Orphan the skb - required as we might hang on to it 417 * for indefinite time. */ 418 skb_orphan(skb); 419 420 /* Enqueue packet */ 421 skb_queue_tail(&tun->socket.sk->sk_receive_queue, skb); 422 423 /* Notify and wake up reader process */ 424 if (tun->flags & TUN_FASYNC) 425 kill_fasync(&tun->fasync, SIGIO, POLL_IN); 426 wake_up_interruptible_poll(&tun->wq.wait, POLLIN | 427 POLLRDNORM | POLLRDBAND); 428 return NETDEV_TX_OK; 429 430 drop: 431 dev->stats.tx_dropped++; 432 kfree_skb(skb); 433 return NETDEV_TX_OK; 434 } 435 436 static void tun_net_mclist(struct net_device *dev) 437 { 438 /* 439 * This callback is supposed to deal with mc filter in 440 * _rx_ path and has nothing to do with the _tx_ path. 441 * In rx path we always accept everything userspace gives us. 442 */ 443 } 444 445 #define MIN_MTU 68 446 #define MAX_MTU 65535 447 448 static int 449 tun_net_change_mtu(struct net_device *dev, int new_mtu) 450 { 451 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU) 452 return -EINVAL; 453 dev->mtu = new_mtu; 454 return 0; 455 } 456 457 static u32 tun_net_fix_features(struct net_device *dev, u32 features) 458 { 459 struct tun_struct *tun = netdev_priv(dev); 460 461 return (features & tun->set_features) | (features & ~TUN_USER_FEATURES); 462 } 463 #ifdef CONFIG_NET_POLL_CONTROLLER 464 static void tun_poll_controller(struct net_device *dev) 465 { 466 /* 467 * Tun only receives frames when: 468 * 1) the char device endpoint gets data from user space 469 * 2) the tun socket gets a sendmsg call from user space 470 * Since both of those are syncronous operations, we are guaranteed 471 * never to have pending data when we poll for it 472 * so theres nothing to do here but return. 473 * We need this though so netpoll recognizes us as an interface that 474 * supports polling, which enables bridge devices in virt setups to 475 * still use netconsole 476 */ 477 return; 478 } 479 #endif 480 static const struct net_device_ops tun_netdev_ops = { 481 .ndo_uninit = tun_net_uninit, 482 .ndo_open = tun_net_open, 483 .ndo_stop = tun_net_close, 484 .ndo_start_xmit = tun_net_xmit, 485 .ndo_change_mtu = tun_net_change_mtu, 486 .ndo_fix_features = tun_net_fix_features, 487 #ifdef CONFIG_NET_POLL_CONTROLLER 488 .ndo_poll_controller = tun_poll_controller, 489 #endif 490 }; 491 492 static const struct net_device_ops tap_netdev_ops = { 493 .ndo_uninit = tun_net_uninit, 494 .ndo_open = tun_net_open, 495 .ndo_stop = tun_net_close, 496 .ndo_start_xmit = tun_net_xmit, 497 .ndo_change_mtu = tun_net_change_mtu, 498 .ndo_fix_features = tun_net_fix_features, 499 .ndo_set_multicast_list = tun_net_mclist, 500 .ndo_set_mac_address = eth_mac_addr, 501 .ndo_validate_addr = eth_validate_addr, 502 #ifdef CONFIG_NET_POLL_CONTROLLER 503 .ndo_poll_controller = tun_poll_controller, 504 #endif 505 }; 506 507 /* Initialize net device. */ 508 static void tun_net_init(struct net_device *dev) 509 { 510 struct tun_struct *tun = netdev_priv(dev); 511 512 switch (tun->flags & TUN_TYPE_MASK) { 513 case TUN_TUN_DEV: 514 dev->netdev_ops = &tun_netdev_ops; 515 516 /* Point-to-Point TUN Device */ 517 dev->hard_header_len = 0; 518 dev->addr_len = 0; 519 dev->mtu = 1500; 520 521 /* Zero header length */ 522 dev->type = ARPHRD_NONE; 523 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 524 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */ 525 break; 526 527 case TUN_TAP_DEV: 528 dev->netdev_ops = &tap_netdev_ops; 529 /* Ethernet TAP Device */ 530 ether_setup(dev); 531 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 532 533 random_ether_addr(dev->dev_addr); 534 535 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */ 536 break; 537 } 538 } 539 540 /* Character device part */ 541 542 /* Poll */ 543 static unsigned int tun_chr_poll(struct file *file, poll_table * wait) 544 { 545 struct tun_file *tfile = file->private_data; 546 struct tun_struct *tun = __tun_get(tfile); 547 struct sock *sk; 548 unsigned int mask = 0; 549 550 if (!tun) 551 return POLLERR; 552 553 sk = tun->socket.sk; 554 555 tun_debug(KERN_INFO, tun, "tun_chr_poll\n"); 556 557 poll_wait(file, &tun->wq.wait, wait); 558 559 if (!skb_queue_empty(&sk->sk_receive_queue)) 560 mask |= POLLIN | POLLRDNORM; 561 562 if (sock_writeable(sk) || 563 (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) && 564 sock_writeable(sk))) 565 mask |= POLLOUT | POLLWRNORM; 566 567 if (tun->dev->reg_state != NETREG_REGISTERED) 568 mask = POLLERR; 569 570 tun_put(tun); 571 return mask; 572 } 573 574 /* prepad is the amount to reserve at front. len is length after that. 575 * linear is a hint as to how much to copy (usually headers). */ 576 static struct sk_buff *tun_alloc_skb(struct tun_struct *tun, 577 size_t prepad, size_t len, 578 size_t linear, int noblock) 579 { 580 struct sock *sk = tun->socket.sk; 581 struct sk_buff *skb; 582 int err; 583 584 sock_update_classid(sk); 585 586 /* Under a page? Don't bother with paged skb. */ 587 if (prepad + len < PAGE_SIZE || !linear) 588 linear = len; 589 590 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 591 &err); 592 if (!skb) 593 return ERR_PTR(err); 594 595 skb_reserve(skb, prepad); 596 skb_put(skb, linear); 597 skb->data_len = len - linear; 598 skb->len += len - linear; 599 600 return skb; 601 } 602 603 /* Get packet from user space buffer */ 604 static ssize_t tun_get_user(struct tun_struct *tun, 605 const struct iovec *iv, size_t count, 606 int noblock) 607 { 608 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) }; 609 struct sk_buff *skb; 610 size_t len = count, align = NET_SKB_PAD; 611 struct virtio_net_hdr gso = { 0 }; 612 int offset = 0; 613 614 if (!(tun->flags & TUN_NO_PI)) { 615 if ((len -= sizeof(pi)) > count) 616 return -EINVAL; 617 618 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi))) 619 return -EFAULT; 620 offset += sizeof(pi); 621 } 622 623 if (tun->flags & TUN_VNET_HDR) { 624 if ((len -= tun->vnet_hdr_sz) > count) 625 return -EINVAL; 626 627 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso))) 628 return -EFAULT; 629 630 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 631 gso.csum_start + gso.csum_offset + 2 > gso.hdr_len) 632 gso.hdr_len = gso.csum_start + gso.csum_offset + 2; 633 634 if (gso.hdr_len > len) 635 return -EINVAL; 636 offset += tun->vnet_hdr_sz; 637 } 638 639 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) { 640 align += NET_IP_ALIGN; 641 if (unlikely(len < ETH_HLEN || 642 (gso.hdr_len && gso.hdr_len < ETH_HLEN))) 643 return -EINVAL; 644 } 645 646 skb = tun_alloc_skb(tun, align, len, gso.hdr_len, noblock); 647 if (IS_ERR(skb)) { 648 if (PTR_ERR(skb) != -EAGAIN) 649 tun->dev->stats.rx_dropped++; 650 return PTR_ERR(skb); 651 } 652 653 if (skb_copy_datagram_from_iovec(skb, 0, iv, offset, len)) { 654 tun->dev->stats.rx_dropped++; 655 kfree_skb(skb); 656 return -EFAULT; 657 } 658 659 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 660 if (!skb_partial_csum_set(skb, gso.csum_start, 661 gso.csum_offset)) { 662 tun->dev->stats.rx_frame_errors++; 663 kfree_skb(skb); 664 return -EINVAL; 665 } 666 } 667 668 switch (tun->flags & TUN_TYPE_MASK) { 669 case TUN_TUN_DEV: 670 if (tun->flags & TUN_NO_PI) { 671 switch (skb->data[0] & 0xf0) { 672 case 0x40: 673 pi.proto = htons(ETH_P_IP); 674 break; 675 case 0x60: 676 pi.proto = htons(ETH_P_IPV6); 677 break; 678 default: 679 tun->dev->stats.rx_dropped++; 680 kfree_skb(skb); 681 return -EINVAL; 682 } 683 } 684 685 skb_reset_mac_header(skb); 686 skb->protocol = pi.proto; 687 skb->dev = tun->dev; 688 break; 689 case TUN_TAP_DEV: 690 skb->protocol = eth_type_trans(skb, tun->dev); 691 break; 692 } 693 694 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 695 pr_debug("GSO!\n"); 696 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 697 case VIRTIO_NET_HDR_GSO_TCPV4: 698 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; 699 break; 700 case VIRTIO_NET_HDR_GSO_TCPV6: 701 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; 702 break; 703 case VIRTIO_NET_HDR_GSO_UDP: 704 skb_shinfo(skb)->gso_type = SKB_GSO_UDP; 705 break; 706 default: 707 tun->dev->stats.rx_frame_errors++; 708 kfree_skb(skb); 709 return -EINVAL; 710 } 711 712 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN) 713 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; 714 715 skb_shinfo(skb)->gso_size = gso.gso_size; 716 if (skb_shinfo(skb)->gso_size == 0) { 717 tun->dev->stats.rx_frame_errors++; 718 kfree_skb(skb); 719 return -EINVAL; 720 } 721 722 /* Header must be checked, and gso_segs computed. */ 723 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 724 skb_shinfo(skb)->gso_segs = 0; 725 } 726 727 netif_rx_ni(skb); 728 729 tun->dev->stats.rx_packets++; 730 tun->dev->stats.rx_bytes += len; 731 732 return count; 733 } 734 735 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv, 736 unsigned long count, loff_t pos) 737 { 738 struct file *file = iocb->ki_filp; 739 struct tun_struct *tun = tun_get(file); 740 ssize_t result; 741 742 if (!tun) 743 return -EBADFD; 744 745 tun_debug(KERN_INFO, tun, "tun_chr_write %ld\n", count); 746 747 result = tun_get_user(tun, iv, iov_length(iv, count), 748 file->f_flags & O_NONBLOCK); 749 750 tun_put(tun); 751 return result; 752 } 753 754 /* Put packet to the user space buffer */ 755 static ssize_t tun_put_user(struct tun_struct *tun, 756 struct sk_buff *skb, 757 const struct iovec *iv, int len) 758 { 759 struct tun_pi pi = { 0, skb->protocol }; 760 ssize_t total = 0; 761 762 if (!(tun->flags & TUN_NO_PI)) { 763 if ((len -= sizeof(pi)) < 0) 764 return -EINVAL; 765 766 if (len < skb->len) { 767 /* Packet will be striped */ 768 pi.flags |= TUN_PKT_STRIP; 769 } 770 771 if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi))) 772 return -EFAULT; 773 total += sizeof(pi); 774 } 775 776 if (tun->flags & TUN_VNET_HDR) { 777 struct virtio_net_hdr gso = { 0 }; /* no info leak */ 778 if ((len -= tun->vnet_hdr_sz) < 0) 779 return -EINVAL; 780 781 if (skb_is_gso(skb)) { 782 struct skb_shared_info *sinfo = skb_shinfo(skb); 783 784 /* This is a hint as to how much should be linear. */ 785 gso.hdr_len = skb_headlen(skb); 786 gso.gso_size = sinfo->gso_size; 787 if (sinfo->gso_type & SKB_GSO_TCPV4) 788 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 789 else if (sinfo->gso_type & SKB_GSO_TCPV6) 790 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 791 else if (sinfo->gso_type & SKB_GSO_UDP) 792 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP; 793 else { 794 pr_err("unexpected GSO type: " 795 "0x%x, gso_size %d, hdr_len %d\n", 796 sinfo->gso_type, gso.gso_size, 797 gso.hdr_len); 798 print_hex_dump(KERN_ERR, "tun: ", 799 DUMP_PREFIX_NONE, 800 16, 1, skb->head, 801 min((int)gso.hdr_len, 64), true); 802 WARN_ON_ONCE(1); 803 return -EINVAL; 804 } 805 if (sinfo->gso_type & SKB_GSO_TCP_ECN) 806 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 807 } else 808 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE; 809 810 if (skb->ip_summed == CHECKSUM_PARTIAL) { 811 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 812 gso.csum_start = skb_checksum_start_offset(skb); 813 gso.csum_offset = skb->csum_offset; 814 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 815 gso.flags = VIRTIO_NET_HDR_F_DATA_VALID; 816 } /* else everything is zero */ 817 818 if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total, 819 sizeof(gso)))) 820 return -EFAULT; 821 total += tun->vnet_hdr_sz; 822 } 823 824 len = min_t(int, skb->len, len); 825 826 skb_copy_datagram_const_iovec(skb, 0, iv, total, len); 827 total += skb->len; 828 829 tun->dev->stats.tx_packets++; 830 tun->dev->stats.tx_bytes += len; 831 832 return total; 833 } 834 835 static ssize_t tun_do_read(struct tun_struct *tun, 836 struct kiocb *iocb, const struct iovec *iv, 837 ssize_t len, int noblock) 838 { 839 DECLARE_WAITQUEUE(wait, current); 840 struct sk_buff *skb; 841 ssize_t ret = 0; 842 843 tun_debug(KERN_INFO, tun, "tun_chr_read\n"); 844 845 if (unlikely(!noblock)) 846 add_wait_queue(&tun->wq.wait, &wait); 847 while (len) { 848 current->state = TASK_INTERRUPTIBLE; 849 850 /* Read frames from the queue */ 851 if (!(skb=skb_dequeue(&tun->socket.sk->sk_receive_queue))) { 852 if (noblock) { 853 ret = -EAGAIN; 854 break; 855 } 856 if (signal_pending(current)) { 857 ret = -ERESTARTSYS; 858 break; 859 } 860 if (tun->dev->reg_state != NETREG_REGISTERED) { 861 ret = -EIO; 862 break; 863 } 864 865 /* Nothing to read, let's sleep */ 866 schedule(); 867 continue; 868 } 869 netif_wake_queue(tun->dev); 870 871 ret = tun_put_user(tun, skb, iv, len); 872 kfree_skb(skb); 873 break; 874 } 875 876 current->state = TASK_RUNNING; 877 if (unlikely(!noblock)) 878 remove_wait_queue(&tun->wq.wait, &wait); 879 880 return ret; 881 } 882 883 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv, 884 unsigned long count, loff_t pos) 885 { 886 struct file *file = iocb->ki_filp; 887 struct tun_file *tfile = file->private_data; 888 struct tun_struct *tun = __tun_get(tfile); 889 ssize_t len, ret; 890 891 if (!tun) 892 return -EBADFD; 893 len = iov_length(iv, count); 894 if (len < 0) { 895 ret = -EINVAL; 896 goto out; 897 } 898 899 ret = tun_do_read(tun, iocb, iv, len, file->f_flags & O_NONBLOCK); 900 ret = min_t(ssize_t, ret, len); 901 out: 902 tun_put(tun); 903 return ret; 904 } 905 906 static void tun_setup(struct net_device *dev) 907 { 908 struct tun_struct *tun = netdev_priv(dev); 909 910 tun->owner = -1; 911 tun->group = -1; 912 913 dev->ethtool_ops = &tun_ethtool_ops; 914 dev->destructor = tun_free_netdev; 915 } 916 917 /* Trivial set of netlink ops to allow deleting tun or tap 918 * device with netlink. 919 */ 920 static int tun_validate(struct nlattr *tb[], struct nlattr *data[]) 921 { 922 return -EINVAL; 923 } 924 925 static struct rtnl_link_ops tun_link_ops __read_mostly = { 926 .kind = DRV_NAME, 927 .priv_size = sizeof(struct tun_struct), 928 .setup = tun_setup, 929 .validate = tun_validate, 930 }; 931 932 static void tun_sock_write_space(struct sock *sk) 933 { 934 struct tun_struct *tun; 935 wait_queue_head_t *wqueue; 936 937 if (!sock_writeable(sk)) 938 return; 939 940 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags)) 941 return; 942 943 wqueue = sk_sleep(sk); 944 if (wqueue && waitqueue_active(wqueue)) 945 wake_up_interruptible_sync_poll(wqueue, POLLOUT | 946 POLLWRNORM | POLLWRBAND); 947 948 tun = tun_sk(sk)->tun; 949 kill_fasync(&tun->fasync, SIGIO, POLL_OUT); 950 } 951 952 static void tun_sock_destruct(struct sock *sk) 953 { 954 free_netdev(tun_sk(sk)->tun->dev); 955 } 956 957 static int tun_sendmsg(struct kiocb *iocb, struct socket *sock, 958 struct msghdr *m, size_t total_len) 959 { 960 struct tun_struct *tun = container_of(sock, struct tun_struct, socket); 961 return tun_get_user(tun, m->msg_iov, total_len, 962 m->msg_flags & MSG_DONTWAIT); 963 } 964 965 static int tun_recvmsg(struct kiocb *iocb, struct socket *sock, 966 struct msghdr *m, size_t total_len, 967 int flags) 968 { 969 struct tun_struct *tun = container_of(sock, struct tun_struct, socket); 970 int ret; 971 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC)) 972 return -EINVAL; 973 ret = tun_do_read(tun, iocb, m->msg_iov, total_len, 974 flags & MSG_DONTWAIT); 975 if (ret > total_len) { 976 m->msg_flags |= MSG_TRUNC; 977 ret = flags & MSG_TRUNC ? ret : total_len; 978 } 979 return ret; 980 } 981 982 /* Ops structure to mimic raw sockets with tun */ 983 static const struct proto_ops tun_socket_ops = { 984 .sendmsg = tun_sendmsg, 985 .recvmsg = tun_recvmsg, 986 }; 987 988 static struct proto tun_proto = { 989 .name = "tun", 990 .owner = THIS_MODULE, 991 .obj_size = sizeof(struct tun_sock), 992 }; 993 994 static int tun_flags(struct tun_struct *tun) 995 { 996 int flags = 0; 997 998 if (tun->flags & TUN_TUN_DEV) 999 flags |= IFF_TUN; 1000 else 1001 flags |= IFF_TAP; 1002 1003 if (tun->flags & TUN_NO_PI) 1004 flags |= IFF_NO_PI; 1005 1006 if (tun->flags & TUN_ONE_QUEUE) 1007 flags |= IFF_ONE_QUEUE; 1008 1009 if (tun->flags & TUN_VNET_HDR) 1010 flags |= IFF_VNET_HDR; 1011 1012 return flags; 1013 } 1014 1015 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr, 1016 char *buf) 1017 { 1018 struct tun_struct *tun = netdev_priv(to_net_dev(dev)); 1019 return sprintf(buf, "0x%x\n", tun_flags(tun)); 1020 } 1021 1022 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr, 1023 char *buf) 1024 { 1025 struct tun_struct *tun = netdev_priv(to_net_dev(dev)); 1026 return sprintf(buf, "%d\n", tun->owner); 1027 } 1028 1029 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr, 1030 char *buf) 1031 { 1032 struct tun_struct *tun = netdev_priv(to_net_dev(dev)); 1033 return sprintf(buf, "%d\n", tun->group); 1034 } 1035 1036 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL); 1037 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL); 1038 static DEVICE_ATTR(group, 0444, tun_show_group, NULL); 1039 1040 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) 1041 { 1042 struct sock *sk; 1043 struct tun_struct *tun; 1044 struct net_device *dev; 1045 int err; 1046 1047 dev = __dev_get_by_name(net, ifr->ifr_name); 1048 if (dev) { 1049 const struct cred *cred = current_cred(); 1050 1051 if (ifr->ifr_flags & IFF_TUN_EXCL) 1052 return -EBUSY; 1053 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops) 1054 tun = netdev_priv(dev); 1055 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops) 1056 tun = netdev_priv(dev); 1057 else 1058 return -EINVAL; 1059 1060 if (((tun->owner != -1 && cred->euid != tun->owner) || 1061 (tun->group != -1 && !in_egroup_p(tun->group))) && 1062 !capable(CAP_NET_ADMIN)) 1063 return -EPERM; 1064 err = security_tun_dev_attach(tun->socket.sk); 1065 if (err < 0) 1066 return err; 1067 1068 err = tun_attach(tun, file); 1069 if (err < 0) 1070 return err; 1071 } 1072 else { 1073 char *name; 1074 unsigned long flags = 0; 1075 1076 if (!capable(CAP_NET_ADMIN)) 1077 return -EPERM; 1078 err = security_tun_dev_create(); 1079 if (err < 0) 1080 return err; 1081 1082 /* Set dev type */ 1083 if (ifr->ifr_flags & IFF_TUN) { 1084 /* TUN device */ 1085 flags |= TUN_TUN_DEV; 1086 name = "tun%d"; 1087 } else if (ifr->ifr_flags & IFF_TAP) { 1088 /* TAP device */ 1089 flags |= TUN_TAP_DEV; 1090 name = "tap%d"; 1091 } else 1092 return -EINVAL; 1093 1094 if (*ifr->ifr_name) 1095 name = ifr->ifr_name; 1096 1097 dev = alloc_netdev(sizeof(struct tun_struct), name, 1098 tun_setup); 1099 if (!dev) 1100 return -ENOMEM; 1101 1102 dev_net_set(dev, net); 1103 dev->rtnl_link_ops = &tun_link_ops; 1104 1105 tun = netdev_priv(dev); 1106 tun->dev = dev; 1107 tun->flags = flags; 1108 tun->txflt.count = 0; 1109 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr); 1110 1111 err = -ENOMEM; 1112 sk = sk_alloc(net, AF_UNSPEC, GFP_KERNEL, &tun_proto); 1113 if (!sk) 1114 goto err_free_dev; 1115 1116 tun->socket.wq = &tun->wq; 1117 init_waitqueue_head(&tun->wq.wait); 1118 tun->socket.ops = &tun_socket_ops; 1119 sock_init_data(&tun->socket, sk); 1120 sk->sk_write_space = tun_sock_write_space; 1121 sk->sk_sndbuf = INT_MAX; 1122 1123 tun_sk(sk)->tun = tun; 1124 1125 security_tun_dev_post_create(sk); 1126 1127 tun_net_init(dev); 1128 1129 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | 1130 TUN_USER_FEATURES; 1131 dev->features = dev->hw_features; 1132 1133 err = register_netdevice(tun->dev); 1134 if (err < 0) 1135 goto err_free_sk; 1136 1137 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) || 1138 device_create_file(&tun->dev->dev, &dev_attr_owner) || 1139 device_create_file(&tun->dev->dev, &dev_attr_group)) 1140 pr_err("Failed to create tun sysfs files\n"); 1141 1142 sk->sk_destruct = tun_sock_destruct; 1143 1144 err = tun_attach(tun, file); 1145 if (err < 0) 1146 goto failed; 1147 } 1148 1149 tun_debug(KERN_INFO, tun, "tun_set_iff\n"); 1150 1151 if (ifr->ifr_flags & IFF_NO_PI) 1152 tun->flags |= TUN_NO_PI; 1153 else 1154 tun->flags &= ~TUN_NO_PI; 1155 1156 if (ifr->ifr_flags & IFF_ONE_QUEUE) 1157 tun->flags |= TUN_ONE_QUEUE; 1158 else 1159 tun->flags &= ~TUN_ONE_QUEUE; 1160 1161 if (ifr->ifr_flags & IFF_VNET_HDR) 1162 tun->flags |= TUN_VNET_HDR; 1163 else 1164 tun->flags &= ~TUN_VNET_HDR; 1165 1166 /* Make sure persistent devices do not get stuck in 1167 * xoff state. 1168 */ 1169 if (netif_running(tun->dev)) 1170 netif_wake_queue(tun->dev); 1171 1172 strcpy(ifr->ifr_name, tun->dev->name); 1173 return 0; 1174 1175 err_free_sk: 1176 sock_put(sk); 1177 err_free_dev: 1178 free_netdev(dev); 1179 failed: 1180 return err; 1181 } 1182 1183 static int tun_get_iff(struct net *net, struct tun_struct *tun, 1184 struct ifreq *ifr) 1185 { 1186 tun_debug(KERN_INFO, tun, "tun_get_iff\n"); 1187 1188 strcpy(ifr->ifr_name, tun->dev->name); 1189 1190 ifr->ifr_flags = tun_flags(tun); 1191 1192 return 0; 1193 } 1194 1195 /* This is like a cut-down ethtool ops, except done via tun fd so no 1196 * privs required. */ 1197 static int set_offload(struct tun_struct *tun, unsigned long arg) 1198 { 1199 u32 features = 0; 1200 1201 if (arg & TUN_F_CSUM) { 1202 features |= NETIF_F_HW_CSUM; 1203 arg &= ~TUN_F_CSUM; 1204 1205 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) { 1206 if (arg & TUN_F_TSO_ECN) { 1207 features |= NETIF_F_TSO_ECN; 1208 arg &= ~TUN_F_TSO_ECN; 1209 } 1210 if (arg & TUN_F_TSO4) 1211 features |= NETIF_F_TSO; 1212 if (arg & TUN_F_TSO6) 1213 features |= NETIF_F_TSO6; 1214 arg &= ~(TUN_F_TSO4|TUN_F_TSO6); 1215 } 1216 1217 if (arg & TUN_F_UFO) { 1218 features |= NETIF_F_UFO; 1219 arg &= ~TUN_F_UFO; 1220 } 1221 } 1222 1223 /* This gives the user a way to test for new features in future by 1224 * trying to set them. */ 1225 if (arg) 1226 return -EINVAL; 1227 1228 tun->set_features = features; 1229 netdev_update_features(tun->dev); 1230 1231 return 0; 1232 } 1233 1234 static long __tun_chr_ioctl(struct file *file, unsigned int cmd, 1235 unsigned long arg, int ifreq_len) 1236 { 1237 struct tun_file *tfile = file->private_data; 1238 struct tun_struct *tun; 1239 void __user* argp = (void __user*)arg; 1240 struct sock_fprog fprog; 1241 struct ifreq ifr; 1242 int sndbuf; 1243 int vnet_hdr_sz; 1244 int ret; 1245 1246 if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89) 1247 if (copy_from_user(&ifr, argp, ifreq_len)) 1248 return -EFAULT; 1249 1250 if (cmd == TUNGETFEATURES) { 1251 /* Currently this just means: "what IFF flags are valid?". 1252 * This is needed because we never checked for invalid flags on 1253 * TUNSETIFF. */ 1254 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE | 1255 IFF_VNET_HDR, 1256 (unsigned int __user*)argp); 1257 } 1258 1259 rtnl_lock(); 1260 1261 tun = __tun_get(tfile); 1262 if (cmd == TUNSETIFF && !tun) { 1263 ifr.ifr_name[IFNAMSIZ-1] = '\0'; 1264 1265 ret = tun_set_iff(tfile->net, file, &ifr); 1266 1267 if (ret) 1268 goto unlock; 1269 1270 if (copy_to_user(argp, &ifr, ifreq_len)) 1271 ret = -EFAULT; 1272 goto unlock; 1273 } 1274 1275 ret = -EBADFD; 1276 if (!tun) 1277 goto unlock; 1278 1279 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %d\n", cmd); 1280 1281 ret = 0; 1282 switch (cmd) { 1283 case TUNGETIFF: 1284 ret = tun_get_iff(current->nsproxy->net_ns, tun, &ifr); 1285 if (ret) 1286 break; 1287 1288 if (copy_to_user(argp, &ifr, ifreq_len)) 1289 ret = -EFAULT; 1290 break; 1291 1292 case TUNSETNOCSUM: 1293 /* Disable/Enable checksum */ 1294 1295 /* [unimplemented] */ 1296 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n", 1297 arg ? "disabled" : "enabled"); 1298 break; 1299 1300 case TUNSETPERSIST: 1301 /* Disable/Enable persist mode */ 1302 if (arg) 1303 tun->flags |= TUN_PERSIST; 1304 else 1305 tun->flags &= ~TUN_PERSIST; 1306 1307 tun_debug(KERN_INFO, tun, "persist %s\n", 1308 arg ? "enabled" : "disabled"); 1309 break; 1310 1311 case TUNSETOWNER: 1312 /* Set owner of the device */ 1313 tun->owner = (uid_t) arg; 1314 1315 tun_debug(KERN_INFO, tun, "owner set to %d\n", tun->owner); 1316 break; 1317 1318 case TUNSETGROUP: 1319 /* Set group of the device */ 1320 tun->group= (gid_t) arg; 1321 1322 tun_debug(KERN_INFO, tun, "group set to %d\n", tun->group); 1323 break; 1324 1325 case TUNSETLINK: 1326 /* Only allow setting the type when the interface is down */ 1327 if (tun->dev->flags & IFF_UP) { 1328 tun_debug(KERN_INFO, tun, 1329 "Linktype set failed because interface is up\n"); 1330 ret = -EBUSY; 1331 } else { 1332 tun->dev->type = (int) arg; 1333 tun_debug(KERN_INFO, tun, "linktype set to %d\n", 1334 tun->dev->type); 1335 ret = 0; 1336 } 1337 break; 1338 1339 #ifdef TUN_DEBUG 1340 case TUNSETDEBUG: 1341 tun->debug = arg; 1342 break; 1343 #endif 1344 case TUNSETOFFLOAD: 1345 ret = set_offload(tun, arg); 1346 break; 1347 1348 case TUNSETTXFILTER: 1349 /* Can be set only for TAPs */ 1350 ret = -EINVAL; 1351 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV) 1352 break; 1353 ret = update_filter(&tun->txflt, (void __user *)arg); 1354 break; 1355 1356 case SIOCGIFHWADDR: 1357 /* Get hw address */ 1358 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN); 1359 ifr.ifr_hwaddr.sa_family = tun->dev->type; 1360 if (copy_to_user(argp, &ifr, ifreq_len)) 1361 ret = -EFAULT; 1362 break; 1363 1364 case SIOCSIFHWADDR: 1365 /* Set hw address */ 1366 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n", 1367 ifr.ifr_hwaddr.sa_data); 1368 1369 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr); 1370 break; 1371 1372 case TUNGETSNDBUF: 1373 sndbuf = tun->socket.sk->sk_sndbuf; 1374 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf))) 1375 ret = -EFAULT; 1376 break; 1377 1378 case TUNSETSNDBUF: 1379 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) { 1380 ret = -EFAULT; 1381 break; 1382 } 1383 1384 tun->socket.sk->sk_sndbuf = sndbuf; 1385 break; 1386 1387 case TUNGETVNETHDRSZ: 1388 vnet_hdr_sz = tun->vnet_hdr_sz; 1389 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz))) 1390 ret = -EFAULT; 1391 break; 1392 1393 case TUNSETVNETHDRSZ: 1394 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) { 1395 ret = -EFAULT; 1396 break; 1397 } 1398 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) { 1399 ret = -EINVAL; 1400 break; 1401 } 1402 1403 tun->vnet_hdr_sz = vnet_hdr_sz; 1404 break; 1405 1406 case TUNATTACHFILTER: 1407 /* Can be set only for TAPs */ 1408 ret = -EINVAL; 1409 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV) 1410 break; 1411 ret = -EFAULT; 1412 if (copy_from_user(&fprog, argp, sizeof(fprog))) 1413 break; 1414 1415 ret = sk_attach_filter(&fprog, tun->socket.sk); 1416 break; 1417 1418 case TUNDETACHFILTER: 1419 /* Can be set only for TAPs */ 1420 ret = -EINVAL; 1421 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV) 1422 break; 1423 ret = sk_detach_filter(tun->socket.sk); 1424 break; 1425 1426 default: 1427 ret = -EINVAL; 1428 break; 1429 } 1430 1431 unlock: 1432 rtnl_unlock(); 1433 if (tun) 1434 tun_put(tun); 1435 return ret; 1436 } 1437 1438 static long tun_chr_ioctl(struct file *file, 1439 unsigned int cmd, unsigned long arg) 1440 { 1441 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq)); 1442 } 1443 1444 #ifdef CONFIG_COMPAT 1445 static long tun_chr_compat_ioctl(struct file *file, 1446 unsigned int cmd, unsigned long arg) 1447 { 1448 switch (cmd) { 1449 case TUNSETIFF: 1450 case TUNGETIFF: 1451 case TUNSETTXFILTER: 1452 case TUNGETSNDBUF: 1453 case TUNSETSNDBUF: 1454 case SIOCGIFHWADDR: 1455 case SIOCSIFHWADDR: 1456 arg = (unsigned long)compat_ptr(arg); 1457 break; 1458 default: 1459 arg = (compat_ulong_t)arg; 1460 break; 1461 } 1462 1463 /* 1464 * compat_ifreq is shorter than ifreq, so we must not access beyond 1465 * the end of that structure. All fields that are used in this 1466 * driver are compatible though, we don't need to convert the 1467 * contents. 1468 */ 1469 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq)); 1470 } 1471 #endif /* CONFIG_COMPAT */ 1472 1473 static int tun_chr_fasync(int fd, struct file *file, int on) 1474 { 1475 struct tun_struct *tun = tun_get(file); 1476 int ret; 1477 1478 if (!tun) 1479 return -EBADFD; 1480 1481 tun_debug(KERN_INFO, tun, "tun_chr_fasync %d\n", on); 1482 1483 if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0) 1484 goto out; 1485 1486 if (on) { 1487 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0); 1488 if (ret) 1489 goto out; 1490 tun->flags |= TUN_FASYNC; 1491 } else 1492 tun->flags &= ~TUN_FASYNC; 1493 ret = 0; 1494 out: 1495 tun_put(tun); 1496 return ret; 1497 } 1498 1499 static int tun_chr_open(struct inode *inode, struct file * file) 1500 { 1501 struct tun_file *tfile; 1502 1503 DBG1(KERN_INFO, "tunX: tun_chr_open\n"); 1504 1505 tfile = kmalloc(sizeof(*tfile), GFP_KERNEL); 1506 if (!tfile) 1507 return -ENOMEM; 1508 atomic_set(&tfile->count, 0); 1509 tfile->tun = NULL; 1510 tfile->net = get_net(current->nsproxy->net_ns); 1511 file->private_data = tfile; 1512 return 0; 1513 } 1514 1515 static int tun_chr_close(struct inode *inode, struct file *file) 1516 { 1517 struct tun_file *tfile = file->private_data; 1518 struct tun_struct *tun; 1519 1520 tun = __tun_get(tfile); 1521 if (tun) { 1522 struct net_device *dev = tun->dev; 1523 1524 tun_debug(KERN_INFO, tun, "tun_chr_close\n"); 1525 1526 __tun_detach(tun); 1527 1528 /* If desirable, unregister the netdevice. */ 1529 if (!(tun->flags & TUN_PERSIST)) { 1530 rtnl_lock(); 1531 if (dev->reg_state == NETREG_REGISTERED) 1532 unregister_netdevice(dev); 1533 rtnl_unlock(); 1534 } 1535 } 1536 1537 tun = tfile->tun; 1538 if (tun) 1539 sock_put(tun->socket.sk); 1540 1541 put_net(tfile->net); 1542 kfree(tfile); 1543 1544 return 0; 1545 } 1546 1547 static const struct file_operations tun_fops = { 1548 .owner = THIS_MODULE, 1549 .llseek = no_llseek, 1550 .read = do_sync_read, 1551 .aio_read = tun_chr_aio_read, 1552 .write = do_sync_write, 1553 .aio_write = tun_chr_aio_write, 1554 .poll = tun_chr_poll, 1555 .unlocked_ioctl = tun_chr_ioctl, 1556 #ifdef CONFIG_COMPAT 1557 .compat_ioctl = tun_chr_compat_ioctl, 1558 #endif 1559 .open = tun_chr_open, 1560 .release = tun_chr_close, 1561 .fasync = tun_chr_fasync 1562 }; 1563 1564 static struct miscdevice tun_miscdev = { 1565 .minor = TUN_MINOR, 1566 .name = "tun", 1567 .nodename = "net/tun", 1568 .fops = &tun_fops, 1569 }; 1570 1571 /* ethtool interface */ 1572 1573 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd) 1574 { 1575 cmd->supported = 0; 1576 cmd->advertising = 0; 1577 ethtool_cmd_speed_set(cmd, SPEED_10); 1578 cmd->duplex = DUPLEX_FULL; 1579 cmd->port = PORT_TP; 1580 cmd->phy_address = 0; 1581 cmd->transceiver = XCVR_INTERNAL; 1582 cmd->autoneg = AUTONEG_DISABLE; 1583 cmd->maxtxpkt = 0; 1584 cmd->maxrxpkt = 0; 1585 return 0; 1586 } 1587 1588 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info) 1589 { 1590 struct tun_struct *tun = netdev_priv(dev); 1591 1592 strcpy(info->driver, DRV_NAME); 1593 strcpy(info->version, DRV_VERSION); 1594 strcpy(info->fw_version, "N/A"); 1595 1596 switch (tun->flags & TUN_TYPE_MASK) { 1597 case TUN_TUN_DEV: 1598 strcpy(info->bus_info, "tun"); 1599 break; 1600 case TUN_TAP_DEV: 1601 strcpy(info->bus_info, "tap"); 1602 break; 1603 } 1604 } 1605 1606 static u32 tun_get_msglevel(struct net_device *dev) 1607 { 1608 #ifdef TUN_DEBUG 1609 struct tun_struct *tun = netdev_priv(dev); 1610 return tun->debug; 1611 #else 1612 return -EOPNOTSUPP; 1613 #endif 1614 } 1615 1616 static void tun_set_msglevel(struct net_device *dev, u32 value) 1617 { 1618 #ifdef TUN_DEBUG 1619 struct tun_struct *tun = netdev_priv(dev); 1620 tun->debug = value; 1621 #endif 1622 } 1623 1624 static const struct ethtool_ops tun_ethtool_ops = { 1625 .get_settings = tun_get_settings, 1626 .get_drvinfo = tun_get_drvinfo, 1627 .get_msglevel = tun_get_msglevel, 1628 .set_msglevel = tun_set_msglevel, 1629 .get_link = ethtool_op_get_link, 1630 }; 1631 1632 1633 static int __init tun_init(void) 1634 { 1635 int ret = 0; 1636 1637 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION); 1638 pr_info("%s\n", DRV_COPYRIGHT); 1639 1640 ret = rtnl_link_register(&tun_link_ops); 1641 if (ret) { 1642 pr_err("Can't register link_ops\n"); 1643 goto err_linkops; 1644 } 1645 1646 ret = misc_register(&tun_miscdev); 1647 if (ret) { 1648 pr_err("Can't register misc device %d\n", TUN_MINOR); 1649 goto err_misc; 1650 } 1651 return 0; 1652 err_misc: 1653 rtnl_link_unregister(&tun_link_ops); 1654 err_linkops: 1655 return ret; 1656 } 1657 1658 static void tun_cleanup(void) 1659 { 1660 misc_deregister(&tun_miscdev); 1661 rtnl_link_unregister(&tun_link_ops); 1662 } 1663 1664 /* Get an underlying socket object from tun file. Returns error unless file is 1665 * attached to a device. The returned object works like a packet socket, it 1666 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for 1667 * holding a reference to the file for as long as the socket is in use. */ 1668 struct socket *tun_get_socket(struct file *file) 1669 { 1670 struct tun_struct *tun; 1671 if (file->f_op != &tun_fops) 1672 return ERR_PTR(-EINVAL); 1673 tun = tun_get(file); 1674 if (!tun) 1675 return ERR_PTR(-EBADFD); 1676 tun_put(tun); 1677 return &tun->socket; 1678 } 1679 EXPORT_SYMBOL_GPL(tun_get_socket); 1680 1681 module_init(tun_init); 1682 module_exit(tun_cleanup); 1683 MODULE_DESCRIPTION(DRV_DESCRIPTION); 1684 MODULE_AUTHOR(DRV_COPYRIGHT); 1685 MODULE_LICENSE("GPL"); 1686 MODULE_ALIAS_MISCDEV(TUN_MINOR); 1687 MODULE_ALIAS("devname:net/tun"); 1688