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/uaccess.h> 73 74 /* Uncomment to enable debugging */ 75 /* #define TUN_DEBUG 1 */ 76 77 #ifdef TUN_DEBUG 78 static int debug; 79 80 #define tun_debug(level, tun, fmt, args...) \ 81 do { \ 82 if (tun->debug) \ 83 netdev_printk(level, tun->dev, fmt, ##args); \ 84 } while (0) 85 #define DBG1(level, fmt, args...) \ 86 do { \ 87 if (debug == 2) \ 88 printk(level fmt, ##args); \ 89 } while (0) 90 #else 91 #define tun_debug(level, tun, fmt, args...) \ 92 do { \ 93 if (0) \ 94 netdev_printk(level, tun->dev, fmt, ##args); \ 95 } while (0) 96 #define DBG1(level, fmt, args...) \ 97 do { \ 98 if (0) \ 99 printk(level fmt, ##args); \ 100 } while (0) 101 #endif 102 103 #define FLT_EXACT_COUNT 8 104 struct tap_filter { 105 unsigned int count; /* Number of addrs. Zero means disabled */ 106 u32 mask[2]; /* Mask of the hashed addrs */ 107 unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN]; 108 }; 109 110 struct tun_file { 111 atomic_t count; 112 struct tun_struct *tun; 113 struct net *net; 114 }; 115 116 struct tun_sock; 117 118 struct tun_struct { 119 struct tun_file *tfile; 120 unsigned int flags; 121 uid_t owner; 122 gid_t group; 123 124 struct net_device *dev; 125 netdev_features_t set_features; 126 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \ 127 NETIF_F_TSO6|NETIF_F_UFO) 128 struct fasync_struct *fasync; 129 130 struct tap_filter txflt; 131 struct socket socket; 132 struct socket_wq wq; 133 134 int vnet_hdr_sz; 135 136 #ifdef TUN_DEBUG 137 int debug; 138 #endif 139 }; 140 141 struct tun_sock { 142 struct sock sk; 143 struct tun_struct *tun; 144 }; 145 146 static inline struct tun_sock *tun_sk(struct sock *sk) 147 { 148 return container_of(sk, struct tun_sock, sk); 149 } 150 151 static int tun_attach(struct tun_struct *tun, struct file *file) 152 { 153 struct tun_file *tfile = file->private_data; 154 int err; 155 156 ASSERT_RTNL(); 157 158 netif_tx_lock_bh(tun->dev); 159 160 err = -EINVAL; 161 if (tfile->tun) 162 goto out; 163 164 err = -EBUSY; 165 if (tun->tfile) 166 goto out; 167 168 err = 0; 169 tfile->tun = tun; 170 tun->tfile = tfile; 171 tun->socket.file = file; 172 netif_carrier_on(tun->dev); 173 dev_hold(tun->dev); 174 sock_hold(tun->socket.sk); 175 atomic_inc(&tfile->count); 176 177 out: 178 netif_tx_unlock_bh(tun->dev); 179 return err; 180 } 181 182 static void __tun_detach(struct tun_struct *tun) 183 { 184 /* Detach from net device */ 185 netif_tx_lock_bh(tun->dev); 186 netif_carrier_off(tun->dev); 187 tun->tfile = NULL; 188 tun->socket.file = NULL; 189 netif_tx_unlock_bh(tun->dev); 190 191 /* Drop read queue */ 192 skb_queue_purge(&tun->socket.sk->sk_receive_queue); 193 194 /* Drop the extra count on the net device */ 195 dev_put(tun->dev); 196 } 197 198 static void tun_detach(struct tun_struct *tun) 199 { 200 rtnl_lock(); 201 __tun_detach(tun); 202 rtnl_unlock(); 203 } 204 205 static struct tun_struct *__tun_get(struct tun_file *tfile) 206 { 207 struct tun_struct *tun = NULL; 208 209 if (atomic_inc_not_zero(&tfile->count)) 210 tun = tfile->tun; 211 212 return tun; 213 } 214 215 static struct tun_struct *tun_get(struct file *file) 216 { 217 return __tun_get(file->private_data); 218 } 219 220 static void tun_put(struct tun_struct *tun) 221 { 222 struct tun_file *tfile = tun->tfile; 223 224 if (atomic_dec_and_test(&tfile->count)) 225 tun_detach(tfile->tun); 226 } 227 228 /* TAP filtering */ 229 static void addr_hash_set(u32 *mask, const u8 *addr) 230 { 231 int n = ether_crc(ETH_ALEN, addr) >> 26; 232 mask[n >> 5] |= (1 << (n & 31)); 233 } 234 235 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr) 236 { 237 int n = ether_crc(ETH_ALEN, addr) >> 26; 238 return mask[n >> 5] & (1 << (n & 31)); 239 } 240 241 static int update_filter(struct tap_filter *filter, void __user *arg) 242 { 243 struct { u8 u[ETH_ALEN]; } *addr; 244 struct tun_filter uf; 245 int err, alen, n, nexact; 246 247 if (copy_from_user(&uf, arg, sizeof(uf))) 248 return -EFAULT; 249 250 if (!uf.count) { 251 /* Disabled */ 252 filter->count = 0; 253 return 0; 254 } 255 256 alen = ETH_ALEN * uf.count; 257 addr = kmalloc(alen, GFP_KERNEL); 258 if (!addr) 259 return -ENOMEM; 260 261 if (copy_from_user(addr, arg + sizeof(uf), alen)) { 262 err = -EFAULT; 263 goto done; 264 } 265 266 /* The filter is updated without holding any locks. Which is 267 * perfectly safe. We disable it first and in the worst 268 * case we'll accept a few undesired packets. */ 269 filter->count = 0; 270 wmb(); 271 272 /* Use first set of addresses as an exact filter */ 273 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++) 274 memcpy(filter->addr[n], addr[n].u, ETH_ALEN); 275 276 nexact = n; 277 278 /* Remaining multicast addresses are hashed, 279 * unicast will leave the filter disabled. */ 280 memset(filter->mask, 0, sizeof(filter->mask)); 281 for (; n < uf.count; n++) { 282 if (!is_multicast_ether_addr(addr[n].u)) { 283 err = 0; /* no filter */ 284 goto done; 285 } 286 addr_hash_set(filter->mask, addr[n].u); 287 } 288 289 /* For ALLMULTI just set the mask to all ones. 290 * This overrides the mask populated above. */ 291 if ((uf.flags & TUN_FLT_ALLMULTI)) 292 memset(filter->mask, ~0, sizeof(filter->mask)); 293 294 /* Now enable the filter */ 295 wmb(); 296 filter->count = nexact; 297 298 /* Return the number of exact filters */ 299 err = nexact; 300 301 done: 302 kfree(addr); 303 return err; 304 } 305 306 /* Returns: 0 - drop, !=0 - accept */ 307 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb) 308 { 309 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect 310 * at this point. */ 311 struct ethhdr *eh = (struct ethhdr *) skb->data; 312 int i; 313 314 /* Exact match */ 315 for (i = 0; i < filter->count; i++) 316 if (!compare_ether_addr(eh->h_dest, filter->addr[i])) 317 return 1; 318 319 /* Inexact match (multicast only) */ 320 if (is_multicast_ether_addr(eh->h_dest)) 321 return addr_hash_test(filter->mask, eh->h_dest); 322 323 return 0; 324 } 325 326 /* 327 * Checks whether the packet is accepted or not. 328 * Returns: 0 - drop, !=0 - accept 329 */ 330 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb) 331 { 332 if (!filter->count) 333 return 1; 334 335 return run_filter(filter, skb); 336 } 337 338 /* Network device part of the driver */ 339 340 static const struct ethtool_ops tun_ethtool_ops; 341 342 /* Net device detach from fd. */ 343 static void tun_net_uninit(struct net_device *dev) 344 { 345 struct tun_struct *tun = netdev_priv(dev); 346 struct tun_file *tfile = tun->tfile; 347 348 /* Inform the methods they need to stop using the dev. 349 */ 350 if (tfile) { 351 wake_up_all(&tun->wq.wait); 352 if (atomic_dec_and_test(&tfile->count)) 353 __tun_detach(tun); 354 } 355 } 356 357 static void tun_free_netdev(struct net_device *dev) 358 { 359 struct tun_struct *tun = netdev_priv(dev); 360 361 sk_release_kernel(tun->socket.sk); 362 } 363 364 /* Net device open. */ 365 static int tun_net_open(struct net_device *dev) 366 { 367 netif_start_queue(dev); 368 return 0; 369 } 370 371 /* Net device close. */ 372 static int tun_net_close(struct net_device *dev) 373 { 374 netif_stop_queue(dev); 375 return 0; 376 } 377 378 /* Net device start xmit */ 379 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev) 380 { 381 struct tun_struct *tun = netdev_priv(dev); 382 383 tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len); 384 385 /* Drop packet if interface is not attached */ 386 if (!tun->tfile) 387 goto drop; 388 389 /* Drop if the filter does not like it. 390 * This is a noop if the filter is disabled. 391 * Filter can be enabled only for the TAP devices. */ 392 if (!check_filter(&tun->txflt, skb)) 393 goto drop; 394 395 if (tun->socket.sk->sk_filter && 396 sk_filter(tun->socket.sk, skb)) 397 goto drop; 398 399 if (skb_queue_len(&tun->socket.sk->sk_receive_queue) >= dev->tx_queue_len) { 400 if (!(tun->flags & TUN_ONE_QUEUE)) { 401 /* Normal queueing mode. */ 402 /* Packet scheduler handles dropping of further packets. */ 403 netif_stop_queue(dev); 404 405 /* We won't see all dropped packets individually, so overrun 406 * error is more appropriate. */ 407 dev->stats.tx_fifo_errors++; 408 } else { 409 /* Single queue mode. 410 * Driver handles dropping of all packets itself. */ 411 goto drop; 412 } 413 } 414 415 /* Orphan the skb - required as we might hang on to it 416 * for indefinite time. */ 417 skb_orphan(skb); 418 419 /* Enqueue packet */ 420 skb_queue_tail(&tun->socket.sk->sk_receive_queue, skb); 421 422 /* Notify and wake up reader process */ 423 if (tun->flags & TUN_FASYNC) 424 kill_fasync(&tun->fasync, SIGIO, POLL_IN); 425 wake_up_interruptible_poll(&tun->wq.wait, POLLIN | 426 POLLRDNORM | POLLRDBAND); 427 return NETDEV_TX_OK; 428 429 drop: 430 dev->stats.tx_dropped++; 431 kfree_skb(skb); 432 return NETDEV_TX_OK; 433 } 434 435 static void tun_net_mclist(struct net_device *dev) 436 { 437 /* 438 * This callback is supposed to deal with mc filter in 439 * _rx_ path and has nothing to do with the _tx_ path. 440 * In rx path we always accept everything userspace gives us. 441 */ 442 } 443 444 #define MIN_MTU 68 445 #define MAX_MTU 65535 446 447 static int 448 tun_net_change_mtu(struct net_device *dev, int new_mtu) 449 { 450 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU) 451 return -EINVAL; 452 dev->mtu = new_mtu; 453 return 0; 454 } 455 456 static netdev_features_t tun_net_fix_features(struct net_device *dev, 457 netdev_features_t 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_rx_mode = 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 eth_hw_addr_random(dev); 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 static int tun_release(struct socket *sock) 983 { 984 if (sock->sk) 985 sock_put(sock->sk); 986 return 0; 987 } 988 989 /* Ops structure to mimic raw sockets with tun */ 990 static const struct proto_ops tun_socket_ops = { 991 .sendmsg = tun_sendmsg, 992 .recvmsg = tun_recvmsg, 993 .release = tun_release, 994 }; 995 996 static struct proto tun_proto = { 997 .name = "tun", 998 .owner = THIS_MODULE, 999 .obj_size = sizeof(struct tun_sock), 1000 }; 1001 1002 static int tun_flags(struct tun_struct *tun) 1003 { 1004 int flags = 0; 1005 1006 if (tun->flags & TUN_TUN_DEV) 1007 flags |= IFF_TUN; 1008 else 1009 flags |= IFF_TAP; 1010 1011 if (tun->flags & TUN_NO_PI) 1012 flags |= IFF_NO_PI; 1013 1014 if (tun->flags & TUN_ONE_QUEUE) 1015 flags |= IFF_ONE_QUEUE; 1016 1017 if (tun->flags & TUN_VNET_HDR) 1018 flags |= IFF_VNET_HDR; 1019 1020 return flags; 1021 } 1022 1023 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr, 1024 char *buf) 1025 { 1026 struct tun_struct *tun = netdev_priv(to_net_dev(dev)); 1027 return sprintf(buf, "0x%x\n", tun_flags(tun)); 1028 } 1029 1030 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr, 1031 char *buf) 1032 { 1033 struct tun_struct *tun = netdev_priv(to_net_dev(dev)); 1034 return sprintf(buf, "%d\n", tun->owner); 1035 } 1036 1037 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr, 1038 char *buf) 1039 { 1040 struct tun_struct *tun = netdev_priv(to_net_dev(dev)); 1041 return sprintf(buf, "%d\n", tun->group); 1042 } 1043 1044 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL); 1045 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL); 1046 static DEVICE_ATTR(group, 0444, tun_show_group, NULL); 1047 1048 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) 1049 { 1050 struct sock *sk; 1051 struct tun_struct *tun; 1052 struct net_device *dev; 1053 int err; 1054 1055 dev = __dev_get_by_name(net, ifr->ifr_name); 1056 if (dev) { 1057 const struct cred *cred = current_cred(); 1058 1059 if (ifr->ifr_flags & IFF_TUN_EXCL) 1060 return -EBUSY; 1061 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops) 1062 tun = netdev_priv(dev); 1063 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops) 1064 tun = netdev_priv(dev); 1065 else 1066 return -EINVAL; 1067 1068 if (((tun->owner != -1 && cred->euid != tun->owner) || 1069 (tun->group != -1 && !in_egroup_p(tun->group))) && 1070 !capable(CAP_NET_ADMIN)) 1071 return -EPERM; 1072 err = security_tun_dev_attach(tun->socket.sk); 1073 if (err < 0) 1074 return err; 1075 1076 err = tun_attach(tun, file); 1077 if (err < 0) 1078 return err; 1079 } 1080 else { 1081 char *name; 1082 unsigned long flags = 0; 1083 1084 if (!capable(CAP_NET_ADMIN)) 1085 return -EPERM; 1086 err = security_tun_dev_create(); 1087 if (err < 0) 1088 return err; 1089 1090 /* Set dev type */ 1091 if (ifr->ifr_flags & IFF_TUN) { 1092 /* TUN device */ 1093 flags |= TUN_TUN_DEV; 1094 name = "tun%d"; 1095 } else if (ifr->ifr_flags & IFF_TAP) { 1096 /* TAP device */ 1097 flags |= TUN_TAP_DEV; 1098 name = "tap%d"; 1099 } else 1100 return -EINVAL; 1101 1102 if (*ifr->ifr_name) 1103 name = ifr->ifr_name; 1104 1105 dev = alloc_netdev(sizeof(struct tun_struct), name, 1106 tun_setup); 1107 if (!dev) 1108 return -ENOMEM; 1109 1110 dev_net_set(dev, net); 1111 dev->rtnl_link_ops = &tun_link_ops; 1112 1113 tun = netdev_priv(dev); 1114 tun->dev = dev; 1115 tun->flags = flags; 1116 tun->txflt.count = 0; 1117 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr); 1118 1119 err = -ENOMEM; 1120 sk = sk_alloc(&init_net, AF_UNSPEC, GFP_KERNEL, &tun_proto); 1121 if (!sk) 1122 goto err_free_dev; 1123 1124 sk_change_net(sk, net); 1125 tun->socket.wq = &tun->wq; 1126 init_waitqueue_head(&tun->wq.wait); 1127 tun->socket.ops = &tun_socket_ops; 1128 sock_init_data(&tun->socket, sk); 1129 sk->sk_write_space = tun_sock_write_space; 1130 sk->sk_sndbuf = INT_MAX; 1131 1132 tun_sk(sk)->tun = tun; 1133 1134 security_tun_dev_post_create(sk); 1135 1136 tun_net_init(dev); 1137 1138 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | 1139 TUN_USER_FEATURES; 1140 dev->features = dev->hw_features; 1141 1142 err = register_netdevice(tun->dev); 1143 if (err < 0) 1144 goto err_free_sk; 1145 1146 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) || 1147 device_create_file(&tun->dev->dev, &dev_attr_owner) || 1148 device_create_file(&tun->dev->dev, &dev_attr_group)) 1149 pr_err("Failed to create tun sysfs files\n"); 1150 1151 sk->sk_destruct = tun_sock_destruct; 1152 1153 err = tun_attach(tun, file); 1154 if (err < 0) 1155 goto failed; 1156 } 1157 1158 tun_debug(KERN_INFO, tun, "tun_set_iff\n"); 1159 1160 if (ifr->ifr_flags & IFF_NO_PI) 1161 tun->flags |= TUN_NO_PI; 1162 else 1163 tun->flags &= ~TUN_NO_PI; 1164 1165 if (ifr->ifr_flags & IFF_ONE_QUEUE) 1166 tun->flags |= TUN_ONE_QUEUE; 1167 else 1168 tun->flags &= ~TUN_ONE_QUEUE; 1169 1170 if (ifr->ifr_flags & IFF_VNET_HDR) 1171 tun->flags |= TUN_VNET_HDR; 1172 else 1173 tun->flags &= ~TUN_VNET_HDR; 1174 1175 /* Make sure persistent devices do not get stuck in 1176 * xoff state. 1177 */ 1178 if (netif_running(tun->dev)) 1179 netif_wake_queue(tun->dev); 1180 1181 strcpy(ifr->ifr_name, tun->dev->name); 1182 return 0; 1183 1184 err_free_sk: 1185 tun_free_netdev(dev); 1186 err_free_dev: 1187 free_netdev(dev); 1188 failed: 1189 return err; 1190 } 1191 1192 static int tun_get_iff(struct net *net, struct tun_struct *tun, 1193 struct ifreq *ifr) 1194 { 1195 tun_debug(KERN_INFO, tun, "tun_get_iff\n"); 1196 1197 strcpy(ifr->ifr_name, tun->dev->name); 1198 1199 ifr->ifr_flags = tun_flags(tun); 1200 1201 return 0; 1202 } 1203 1204 /* This is like a cut-down ethtool ops, except done via tun fd so no 1205 * privs required. */ 1206 static int set_offload(struct tun_struct *tun, unsigned long arg) 1207 { 1208 netdev_features_t features = 0; 1209 1210 if (arg & TUN_F_CSUM) { 1211 features |= NETIF_F_HW_CSUM; 1212 arg &= ~TUN_F_CSUM; 1213 1214 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) { 1215 if (arg & TUN_F_TSO_ECN) { 1216 features |= NETIF_F_TSO_ECN; 1217 arg &= ~TUN_F_TSO_ECN; 1218 } 1219 if (arg & TUN_F_TSO4) 1220 features |= NETIF_F_TSO; 1221 if (arg & TUN_F_TSO6) 1222 features |= NETIF_F_TSO6; 1223 arg &= ~(TUN_F_TSO4|TUN_F_TSO6); 1224 } 1225 1226 if (arg & TUN_F_UFO) { 1227 features |= NETIF_F_UFO; 1228 arg &= ~TUN_F_UFO; 1229 } 1230 } 1231 1232 /* This gives the user a way to test for new features in future by 1233 * trying to set them. */ 1234 if (arg) 1235 return -EINVAL; 1236 1237 tun->set_features = features; 1238 netdev_update_features(tun->dev); 1239 1240 return 0; 1241 } 1242 1243 static long __tun_chr_ioctl(struct file *file, unsigned int cmd, 1244 unsigned long arg, int ifreq_len) 1245 { 1246 struct tun_file *tfile = file->private_data; 1247 struct tun_struct *tun; 1248 void __user* argp = (void __user*)arg; 1249 struct sock_fprog fprog; 1250 struct ifreq ifr; 1251 int sndbuf; 1252 int vnet_hdr_sz; 1253 int ret; 1254 1255 if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89) 1256 if (copy_from_user(&ifr, argp, ifreq_len)) 1257 return -EFAULT; 1258 1259 if (cmd == TUNGETFEATURES) { 1260 /* Currently this just means: "what IFF flags are valid?". 1261 * This is needed because we never checked for invalid flags on 1262 * TUNSETIFF. */ 1263 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE | 1264 IFF_VNET_HDR, 1265 (unsigned int __user*)argp); 1266 } 1267 1268 rtnl_lock(); 1269 1270 tun = __tun_get(tfile); 1271 if (cmd == TUNSETIFF && !tun) { 1272 ifr.ifr_name[IFNAMSIZ-1] = '\0'; 1273 1274 ret = tun_set_iff(tfile->net, file, &ifr); 1275 1276 if (ret) 1277 goto unlock; 1278 1279 if (copy_to_user(argp, &ifr, ifreq_len)) 1280 ret = -EFAULT; 1281 goto unlock; 1282 } 1283 1284 ret = -EBADFD; 1285 if (!tun) 1286 goto unlock; 1287 1288 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %d\n", cmd); 1289 1290 ret = 0; 1291 switch (cmd) { 1292 case TUNGETIFF: 1293 ret = tun_get_iff(current->nsproxy->net_ns, tun, &ifr); 1294 if (ret) 1295 break; 1296 1297 if (copy_to_user(argp, &ifr, ifreq_len)) 1298 ret = -EFAULT; 1299 break; 1300 1301 case TUNSETNOCSUM: 1302 /* Disable/Enable checksum */ 1303 1304 /* [unimplemented] */ 1305 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n", 1306 arg ? "disabled" : "enabled"); 1307 break; 1308 1309 case TUNSETPERSIST: 1310 /* Disable/Enable persist mode */ 1311 if (arg) 1312 tun->flags |= TUN_PERSIST; 1313 else 1314 tun->flags &= ~TUN_PERSIST; 1315 1316 tun_debug(KERN_INFO, tun, "persist %s\n", 1317 arg ? "enabled" : "disabled"); 1318 break; 1319 1320 case TUNSETOWNER: 1321 /* Set owner of the device */ 1322 tun->owner = (uid_t) arg; 1323 1324 tun_debug(KERN_INFO, tun, "owner set to %d\n", tun->owner); 1325 break; 1326 1327 case TUNSETGROUP: 1328 /* Set group of the device */ 1329 tun->group= (gid_t) arg; 1330 1331 tun_debug(KERN_INFO, tun, "group set to %d\n", tun->group); 1332 break; 1333 1334 case TUNSETLINK: 1335 /* Only allow setting the type when the interface is down */ 1336 if (tun->dev->flags & IFF_UP) { 1337 tun_debug(KERN_INFO, tun, 1338 "Linktype set failed because interface is up\n"); 1339 ret = -EBUSY; 1340 } else { 1341 tun->dev->type = (int) arg; 1342 tun_debug(KERN_INFO, tun, "linktype set to %d\n", 1343 tun->dev->type); 1344 ret = 0; 1345 } 1346 break; 1347 1348 #ifdef TUN_DEBUG 1349 case TUNSETDEBUG: 1350 tun->debug = arg; 1351 break; 1352 #endif 1353 case TUNSETOFFLOAD: 1354 ret = set_offload(tun, arg); 1355 break; 1356 1357 case TUNSETTXFILTER: 1358 /* Can be set only for TAPs */ 1359 ret = -EINVAL; 1360 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV) 1361 break; 1362 ret = update_filter(&tun->txflt, (void __user *)arg); 1363 break; 1364 1365 case SIOCGIFHWADDR: 1366 /* Get hw address */ 1367 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN); 1368 ifr.ifr_hwaddr.sa_family = tun->dev->type; 1369 if (copy_to_user(argp, &ifr, ifreq_len)) 1370 ret = -EFAULT; 1371 break; 1372 1373 case SIOCSIFHWADDR: 1374 /* Set hw address */ 1375 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n", 1376 ifr.ifr_hwaddr.sa_data); 1377 1378 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr); 1379 break; 1380 1381 case TUNGETSNDBUF: 1382 sndbuf = tun->socket.sk->sk_sndbuf; 1383 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf))) 1384 ret = -EFAULT; 1385 break; 1386 1387 case TUNSETSNDBUF: 1388 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) { 1389 ret = -EFAULT; 1390 break; 1391 } 1392 1393 tun->socket.sk->sk_sndbuf = sndbuf; 1394 break; 1395 1396 case TUNGETVNETHDRSZ: 1397 vnet_hdr_sz = tun->vnet_hdr_sz; 1398 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz))) 1399 ret = -EFAULT; 1400 break; 1401 1402 case TUNSETVNETHDRSZ: 1403 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) { 1404 ret = -EFAULT; 1405 break; 1406 } 1407 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) { 1408 ret = -EINVAL; 1409 break; 1410 } 1411 1412 tun->vnet_hdr_sz = vnet_hdr_sz; 1413 break; 1414 1415 case TUNATTACHFILTER: 1416 /* Can be set only for TAPs */ 1417 ret = -EINVAL; 1418 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV) 1419 break; 1420 ret = -EFAULT; 1421 if (copy_from_user(&fprog, argp, sizeof(fprog))) 1422 break; 1423 1424 ret = sk_attach_filter(&fprog, tun->socket.sk); 1425 break; 1426 1427 case TUNDETACHFILTER: 1428 /* Can be set only for TAPs */ 1429 ret = -EINVAL; 1430 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV) 1431 break; 1432 ret = sk_detach_filter(tun->socket.sk); 1433 break; 1434 1435 default: 1436 ret = -EINVAL; 1437 break; 1438 } 1439 1440 unlock: 1441 rtnl_unlock(); 1442 if (tun) 1443 tun_put(tun); 1444 return ret; 1445 } 1446 1447 static long tun_chr_ioctl(struct file *file, 1448 unsigned int cmd, unsigned long arg) 1449 { 1450 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq)); 1451 } 1452 1453 #ifdef CONFIG_COMPAT 1454 static long tun_chr_compat_ioctl(struct file *file, 1455 unsigned int cmd, unsigned long arg) 1456 { 1457 switch (cmd) { 1458 case TUNSETIFF: 1459 case TUNGETIFF: 1460 case TUNSETTXFILTER: 1461 case TUNGETSNDBUF: 1462 case TUNSETSNDBUF: 1463 case SIOCGIFHWADDR: 1464 case SIOCSIFHWADDR: 1465 arg = (unsigned long)compat_ptr(arg); 1466 break; 1467 default: 1468 arg = (compat_ulong_t)arg; 1469 break; 1470 } 1471 1472 /* 1473 * compat_ifreq is shorter than ifreq, so we must not access beyond 1474 * the end of that structure. All fields that are used in this 1475 * driver are compatible though, we don't need to convert the 1476 * contents. 1477 */ 1478 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq)); 1479 } 1480 #endif /* CONFIG_COMPAT */ 1481 1482 static int tun_chr_fasync(int fd, struct file *file, int on) 1483 { 1484 struct tun_struct *tun = tun_get(file); 1485 int ret; 1486 1487 if (!tun) 1488 return -EBADFD; 1489 1490 tun_debug(KERN_INFO, tun, "tun_chr_fasync %d\n", on); 1491 1492 if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0) 1493 goto out; 1494 1495 if (on) { 1496 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0); 1497 if (ret) 1498 goto out; 1499 tun->flags |= TUN_FASYNC; 1500 } else 1501 tun->flags &= ~TUN_FASYNC; 1502 ret = 0; 1503 out: 1504 tun_put(tun); 1505 return ret; 1506 } 1507 1508 static int tun_chr_open(struct inode *inode, struct file * file) 1509 { 1510 struct tun_file *tfile; 1511 1512 DBG1(KERN_INFO, "tunX: tun_chr_open\n"); 1513 1514 tfile = kmalloc(sizeof(*tfile), GFP_KERNEL); 1515 if (!tfile) 1516 return -ENOMEM; 1517 atomic_set(&tfile->count, 0); 1518 tfile->tun = NULL; 1519 tfile->net = get_net(current->nsproxy->net_ns); 1520 file->private_data = tfile; 1521 return 0; 1522 } 1523 1524 static int tun_chr_close(struct inode *inode, struct file *file) 1525 { 1526 struct tun_file *tfile = file->private_data; 1527 struct tun_struct *tun; 1528 1529 tun = __tun_get(tfile); 1530 if (tun) { 1531 struct net_device *dev = tun->dev; 1532 1533 tun_debug(KERN_INFO, tun, "tun_chr_close\n"); 1534 1535 __tun_detach(tun); 1536 1537 /* If desirable, unregister the netdevice. */ 1538 if (!(tun->flags & TUN_PERSIST)) { 1539 rtnl_lock(); 1540 if (dev->reg_state == NETREG_REGISTERED) 1541 unregister_netdevice(dev); 1542 rtnl_unlock(); 1543 } 1544 } 1545 1546 tun = tfile->tun; 1547 if (tun) 1548 sock_put(tun->socket.sk); 1549 1550 put_net(tfile->net); 1551 kfree(tfile); 1552 1553 return 0; 1554 } 1555 1556 static const struct file_operations tun_fops = { 1557 .owner = THIS_MODULE, 1558 .llseek = no_llseek, 1559 .read = do_sync_read, 1560 .aio_read = tun_chr_aio_read, 1561 .write = do_sync_write, 1562 .aio_write = tun_chr_aio_write, 1563 .poll = tun_chr_poll, 1564 .unlocked_ioctl = tun_chr_ioctl, 1565 #ifdef CONFIG_COMPAT 1566 .compat_ioctl = tun_chr_compat_ioctl, 1567 #endif 1568 .open = tun_chr_open, 1569 .release = tun_chr_close, 1570 .fasync = tun_chr_fasync 1571 }; 1572 1573 static struct miscdevice tun_miscdev = { 1574 .minor = TUN_MINOR, 1575 .name = "tun", 1576 .nodename = "net/tun", 1577 .fops = &tun_fops, 1578 }; 1579 1580 /* ethtool interface */ 1581 1582 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd) 1583 { 1584 cmd->supported = 0; 1585 cmd->advertising = 0; 1586 ethtool_cmd_speed_set(cmd, SPEED_10); 1587 cmd->duplex = DUPLEX_FULL; 1588 cmd->port = PORT_TP; 1589 cmd->phy_address = 0; 1590 cmd->transceiver = XCVR_INTERNAL; 1591 cmd->autoneg = AUTONEG_DISABLE; 1592 cmd->maxtxpkt = 0; 1593 cmd->maxrxpkt = 0; 1594 return 0; 1595 } 1596 1597 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info) 1598 { 1599 struct tun_struct *tun = netdev_priv(dev); 1600 1601 strlcpy(info->driver, DRV_NAME, sizeof(info->driver)); 1602 strlcpy(info->version, DRV_VERSION, sizeof(info->version)); 1603 1604 switch (tun->flags & TUN_TYPE_MASK) { 1605 case TUN_TUN_DEV: 1606 strlcpy(info->bus_info, "tun", sizeof(info->bus_info)); 1607 break; 1608 case TUN_TAP_DEV: 1609 strlcpy(info->bus_info, "tap", sizeof(info->bus_info)); 1610 break; 1611 } 1612 } 1613 1614 static u32 tun_get_msglevel(struct net_device *dev) 1615 { 1616 #ifdef TUN_DEBUG 1617 struct tun_struct *tun = netdev_priv(dev); 1618 return tun->debug; 1619 #else 1620 return -EOPNOTSUPP; 1621 #endif 1622 } 1623 1624 static void tun_set_msglevel(struct net_device *dev, u32 value) 1625 { 1626 #ifdef TUN_DEBUG 1627 struct tun_struct *tun = netdev_priv(dev); 1628 tun->debug = value; 1629 #endif 1630 } 1631 1632 static const struct ethtool_ops tun_ethtool_ops = { 1633 .get_settings = tun_get_settings, 1634 .get_drvinfo = tun_get_drvinfo, 1635 .get_msglevel = tun_get_msglevel, 1636 .set_msglevel = tun_set_msglevel, 1637 .get_link = ethtool_op_get_link, 1638 }; 1639 1640 1641 static int __init tun_init(void) 1642 { 1643 int ret = 0; 1644 1645 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION); 1646 pr_info("%s\n", DRV_COPYRIGHT); 1647 1648 ret = rtnl_link_register(&tun_link_ops); 1649 if (ret) { 1650 pr_err("Can't register link_ops\n"); 1651 goto err_linkops; 1652 } 1653 1654 ret = misc_register(&tun_miscdev); 1655 if (ret) { 1656 pr_err("Can't register misc device %d\n", TUN_MINOR); 1657 goto err_misc; 1658 } 1659 return 0; 1660 err_misc: 1661 rtnl_link_unregister(&tun_link_ops); 1662 err_linkops: 1663 return ret; 1664 } 1665 1666 static void tun_cleanup(void) 1667 { 1668 misc_deregister(&tun_miscdev); 1669 rtnl_link_unregister(&tun_link_ops); 1670 } 1671 1672 /* Get an underlying socket object from tun file. Returns error unless file is 1673 * attached to a device. The returned object works like a packet socket, it 1674 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for 1675 * holding a reference to the file for as long as the socket is in use. */ 1676 struct socket *tun_get_socket(struct file *file) 1677 { 1678 struct tun_struct *tun; 1679 if (file->f_op != &tun_fops) 1680 return ERR_PTR(-EINVAL); 1681 tun = tun_get(file); 1682 if (!tun) 1683 return ERR_PTR(-EBADFD); 1684 tun_put(tun); 1685 return &tun->socket; 1686 } 1687 EXPORT_SYMBOL_GPL(tun_get_socket); 1688 1689 module_init(tun_init); 1690 module_exit(tun_cleanup); 1691 MODULE_DESCRIPTION(DRV_DESCRIPTION); 1692 MODULE_AUTHOR(DRV_COPYRIGHT); 1693 MODULE_LICENSE("GPL"); 1694 MODULE_ALIAS_MISCDEV(TUN_MINOR); 1695 MODULE_ALIAS("devname:net/tun"); 1696