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 netdev_features_t 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 sk_release_kernel(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 netdev_features_t tun_net_fix_features(struct net_device *dev, 458 netdev_features_t features) 459 { 460 struct tun_struct *tun = netdev_priv(dev); 461 462 return (features & tun->set_features) | (features & ~TUN_USER_FEATURES); 463 } 464 #ifdef CONFIG_NET_POLL_CONTROLLER 465 static void tun_poll_controller(struct net_device *dev) 466 { 467 /* 468 * Tun only receives frames when: 469 * 1) the char device endpoint gets data from user space 470 * 2) the tun socket gets a sendmsg call from user space 471 * Since both of those are syncronous operations, we are guaranteed 472 * never to have pending data when we poll for it 473 * so theres nothing to do here but return. 474 * We need this though so netpoll recognizes us as an interface that 475 * supports polling, which enables bridge devices in virt setups to 476 * still use netconsole 477 */ 478 return; 479 } 480 #endif 481 static const struct net_device_ops tun_netdev_ops = { 482 .ndo_uninit = tun_net_uninit, 483 .ndo_open = tun_net_open, 484 .ndo_stop = tun_net_close, 485 .ndo_start_xmit = tun_net_xmit, 486 .ndo_change_mtu = tun_net_change_mtu, 487 .ndo_fix_features = tun_net_fix_features, 488 #ifdef CONFIG_NET_POLL_CONTROLLER 489 .ndo_poll_controller = tun_poll_controller, 490 #endif 491 }; 492 493 static const struct net_device_ops tap_netdev_ops = { 494 .ndo_uninit = tun_net_uninit, 495 .ndo_open = tun_net_open, 496 .ndo_stop = tun_net_close, 497 .ndo_start_xmit = tun_net_xmit, 498 .ndo_change_mtu = tun_net_change_mtu, 499 .ndo_fix_features = tun_net_fix_features, 500 .ndo_set_rx_mode = tun_net_mclist, 501 .ndo_set_mac_address = eth_mac_addr, 502 .ndo_validate_addr = eth_validate_addr, 503 #ifdef CONFIG_NET_POLL_CONTROLLER 504 .ndo_poll_controller = tun_poll_controller, 505 #endif 506 }; 507 508 /* Initialize net device. */ 509 static void tun_net_init(struct net_device *dev) 510 { 511 struct tun_struct *tun = netdev_priv(dev); 512 513 switch (tun->flags & TUN_TYPE_MASK) { 514 case TUN_TUN_DEV: 515 dev->netdev_ops = &tun_netdev_ops; 516 517 /* Point-to-Point TUN Device */ 518 dev->hard_header_len = 0; 519 dev->addr_len = 0; 520 dev->mtu = 1500; 521 522 /* Zero header length */ 523 dev->type = ARPHRD_NONE; 524 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 525 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */ 526 break; 527 528 case TUN_TAP_DEV: 529 dev->netdev_ops = &tap_netdev_ops; 530 /* Ethernet TAP Device */ 531 ether_setup(dev); 532 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 533 534 eth_hw_addr_random(dev); 535 536 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */ 537 break; 538 } 539 } 540 541 /* Character device part */ 542 543 /* Poll */ 544 static unsigned int tun_chr_poll(struct file *file, poll_table * wait) 545 { 546 struct tun_file *tfile = file->private_data; 547 struct tun_struct *tun = __tun_get(tfile); 548 struct sock *sk; 549 unsigned int mask = 0; 550 551 if (!tun) 552 return POLLERR; 553 554 sk = tun->socket.sk; 555 556 tun_debug(KERN_INFO, tun, "tun_chr_poll\n"); 557 558 poll_wait(file, &tun->wq.wait, wait); 559 560 if (!skb_queue_empty(&sk->sk_receive_queue)) 561 mask |= POLLIN | POLLRDNORM; 562 563 if (sock_writeable(sk) || 564 (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) && 565 sock_writeable(sk))) 566 mask |= POLLOUT | POLLWRNORM; 567 568 if (tun->dev->reg_state != NETREG_REGISTERED) 569 mask = POLLERR; 570 571 tun_put(tun); 572 return mask; 573 } 574 575 /* prepad is the amount to reserve at front. len is length after that. 576 * linear is a hint as to how much to copy (usually headers). */ 577 static struct sk_buff *tun_alloc_skb(struct tun_struct *tun, 578 size_t prepad, size_t len, 579 size_t linear, int noblock) 580 { 581 struct sock *sk = tun->socket.sk; 582 struct sk_buff *skb; 583 int err; 584 585 sock_update_classid(sk); 586 587 /* Under a page? Don't bother with paged skb. */ 588 if (prepad + len < PAGE_SIZE || !linear) 589 linear = len; 590 591 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 592 &err); 593 if (!skb) 594 return ERR_PTR(err); 595 596 skb_reserve(skb, prepad); 597 skb_put(skb, linear); 598 skb->data_len = len - linear; 599 skb->len += len - linear; 600 601 return skb; 602 } 603 604 /* Get packet from user space buffer */ 605 static ssize_t tun_get_user(struct tun_struct *tun, 606 const struct iovec *iv, size_t count, 607 int noblock) 608 { 609 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) }; 610 struct sk_buff *skb; 611 size_t len = count, align = NET_SKB_PAD; 612 struct virtio_net_hdr gso = { 0 }; 613 int offset = 0; 614 615 if (!(tun->flags & TUN_NO_PI)) { 616 if ((len -= sizeof(pi)) > count) 617 return -EINVAL; 618 619 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi))) 620 return -EFAULT; 621 offset += sizeof(pi); 622 } 623 624 if (tun->flags & TUN_VNET_HDR) { 625 if ((len -= tun->vnet_hdr_sz) > count) 626 return -EINVAL; 627 628 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso))) 629 return -EFAULT; 630 631 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 632 gso.csum_start + gso.csum_offset + 2 > gso.hdr_len) 633 gso.hdr_len = gso.csum_start + gso.csum_offset + 2; 634 635 if (gso.hdr_len > len) 636 return -EINVAL; 637 offset += tun->vnet_hdr_sz; 638 } 639 640 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) { 641 align += NET_IP_ALIGN; 642 if (unlikely(len < ETH_HLEN || 643 (gso.hdr_len && gso.hdr_len < ETH_HLEN))) 644 return -EINVAL; 645 } 646 647 skb = tun_alloc_skb(tun, align, len, gso.hdr_len, noblock); 648 if (IS_ERR(skb)) { 649 if (PTR_ERR(skb) != -EAGAIN) 650 tun->dev->stats.rx_dropped++; 651 return PTR_ERR(skb); 652 } 653 654 if (skb_copy_datagram_from_iovec(skb, 0, iv, offset, len)) { 655 tun->dev->stats.rx_dropped++; 656 kfree_skb(skb); 657 return -EFAULT; 658 } 659 660 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 661 if (!skb_partial_csum_set(skb, gso.csum_start, 662 gso.csum_offset)) { 663 tun->dev->stats.rx_frame_errors++; 664 kfree_skb(skb); 665 return -EINVAL; 666 } 667 } 668 669 switch (tun->flags & TUN_TYPE_MASK) { 670 case TUN_TUN_DEV: 671 if (tun->flags & TUN_NO_PI) { 672 switch (skb->data[0] & 0xf0) { 673 case 0x40: 674 pi.proto = htons(ETH_P_IP); 675 break; 676 case 0x60: 677 pi.proto = htons(ETH_P_IPV6); 678 break; 679 default: 680 tun->dev->stats.rx_dropped++; 681 kfree_skb(skb); 682 return -EINVAL; 683 } 684 } 685 686 skb_reset_mac_header(skb); 687 skb->protocol = pi.proto; 688 skb->dev = tun->dev; 689 break; 690 case TUN_TAP_DEV: 691 skb->protocol = eth_type_trans(skb, tun->dev); 692 break; 693 } 694 695 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 696 pr_debug("GSO!\n"); 697 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 698 case VIRTIO_NET_HDR_GSO_TCPV4: 699 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; 700 break; 701 case VIRTIO_NET_HDR_GSO_TCPV6: 702 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; 703 break; 704 case VIRTIO_NET_HDR_GSO_UDP: 705 skb_shinfo(skb)->gso_type = SKB_GSO_UDP; 706 break; 707 default: 708 tun->dev->stats.rx_frame_errors++; 709 kfree_skb(skb); 710 return -EINVAL; 711 } 712 713 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN) 714 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; 715 716 skb_shinfo(skb)->gso_size = gso.gso_size; 717 if (skb_shinfo(skb)->gso_size == 0) { 718 tun->dev->stats.rx_frame_errors++; 719 kfree_skb(skb); 720 return -EINVAL; 721 } 722 723 /* Header must be checked, and gso_segs computed. */ 724 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 725 skb_shinfo(skb)->gso_segs = 0; 726 } 727 728 netif_rx_ni(skb); 729 730 tun->dev->stats.rx_packets++; 731 tun->dev->stats.rx_bytes += len; 732 733 return count; 734 } 735 736 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv, 737 unsigned long count, loff_t pos) 738 { 739 struct file *file = iocb->ki_filp; 740 struct tun_struct *tun = tun_get(file); 741 ssize_t result; 742 743 if (!tun) 744 return -EBADFD; 745 746 tun_debug(KERN_INFO, tun, "tun_chr_write %ld\n", count); 747 748 result = tun_get_user(tun, iv, iov_length(iv, count), 749 file->f_flags & O_NONBLOCK); 750 751 tun_put(tun); 752 return result; 753 } 754 755 /* Put packet to the user space buffer */ 756 static ssize_t tun_put_user(struct tun_struct *tun, 757 struct sk_buff *skb, 758 const struct iovec *iv, int len) 759 { 760 struct tun_pi pi = { 0, skb->protocol }; 761 ssize_t total = 0; 762 763 if (!(tun->flags & TUN_NO_PI)) { 764 if ((len -= sizeof(pi)) < 0) 765 return -EINVAL; 766 767 if (len < skb->len) { 768 /* Packet will be striped */ 769 pi.flags |= TUN_PKT_STRIP; 770 } 771 772 if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi))) 773 return -EFAULT; 774 total += sizeof(pi); 775 } 776 777 if (tun->flags & TUN_VNET_HDR) { 778 struct virtio_net_hdr gso = { 0 }; /* no info leak */ 779 if ((len -= tun->vnet_hdr_sz) < 0) 780 return -EINVAL; 781 782 if (skb_is_gso(skb)) { 783 struct skb_shared_info *sinfo = skb_shinfo(skb); 784 785 /* This is a hint as to how much should be linear. */ 786 gso.hdr_len = skb_headlen(skb); 787 gso.gso_size = sinfo->gso_size; 788 if (sinfo->gso_type & SKB_GSO_TCPV4) 789 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 790 else if (sinfo->gso_type & SKB_GSO_TCPV6) 791 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 792 else if (sinfo->gso_type & SKB_GSO_UDP) 793 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP; 794 else { 795 pr_err("unexpected GSO type: " 796 "0x%x, gso_size %d, hdr_len %d\n", 797 sinfo->gso_type, gso.gso_size, 798 gso.hdr_len); 799 print_hex_dump(KERN_ERR, "tun: ", 800 DUMP_PREFIX_NONE, 801 16, 1, skb->head, 802 min((int)gso.hdr_len, 64), true); 803 WARN_ON_ONCE(1); 804 return -EINVAL; 805 } 806 if (sinfo->gso_type & SKB_GSO_TCP_ECN) 807 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 808 } else 809 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE; 810 811 if (skb->ip_summed == CHECKSUM_PARTIAL) { 812 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 813 gso.csum_start = skb_checksum_start_offset(skb); 814 gso.csum_offset = skb->csum_offset; 815 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 816 gso.flags = VIRTIO_NET_HDR_F_DATA_VALID; 817 } /* else everything is zero */ 818 819 if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total, 820 sizeof(gso)))) 821 return -EFAULT; 822 total += tun->vnet_hdr_sz; 823 } 824 825 len = min_t(int, skb->len, len); 826 827 skb_copy_datagram_const_iovec(skb, 0, iv, total, len); 828 total += skb->len; 829 830 tun->dev->stats.tx_packets++; 831 tun->dev->stats.tx_bytes += len; 832 833 return total; 834 } 835 836 static ssize_t tun_do_read(struct tun_struct *tun, 837 struct kiocb *iocb, const struct iovec *iv, 838 ssize_t len, int noblock) 839 { 840 DECLARE_WAITQUEUE(wait, current); 841 struct sk_buff *skb; 842 ssize_t ret = 0; 843 844 tun_debug(KERN_INFO, tun, "tun_chr_read\n"); 845 846 if (unlikely(!noblock)) 847 add_wait_queue(&tun->wq.wait, &wait); 848 while (len) { 849 current->state = TASK_INTERRUPTIBLE; 850 851 /* Read frames from the queue */ 852 if (!(skb=skb_dequeue(&tun->socket.sk->sk_receive_queue))) { 853 if (noblock) { 854 ret = -EAGAIN; 855 break; 856 } 857 if (signal_pending(current)) { 858 ret = -ERESTARTSYS; 859 break; 860 } 861 if (tun->dev->reg_state != NETREG_REGISTERED) { 862 ret = -EIO; 863 break; 864 } 865 866 /* Nothing to read, let's sleep */ 867 schedule(); 868 continue; 869 } 870 netif_wake_queue(tun->dev); 871 872 ret = tun_put_user(tun, skb, iv, len); 873 kfree_skb(skb); 874 break; 875 } 876 877 current->state = TASK_RUNNING; 878 if (unlikely(!noblock)) 879 remove_wait_queue(&tun->wq.wait, &wait); 880 881 return ret; 882 } 883 884 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv, 885 unsigned long count, loff_t pos) 886 { 887 struct file *file = iocb->ki_filp; 888 struct tun_file *tfile = file->private_data; 889 struct tun_struct *tun = __tun_get(tfile); 890 ssize_t len, ret; 891 892 if (!tun) 893 return -EBADFD; 894 len = iov_length(iv, count); 895 if (len < 0) { 896 ret = -EINVAL; 897 goto out; 898 } 899 900 ret = tun_do_read(tun, iocb, iv, len, file->f_flags & O_NONBLOCK); 901 ret = min_t(ssize_t, ret, len); 902 out: 903 tun_put(tun); 904 return ret; 905 } 906 907 static void tun_setup(struct net_device *dev) 908 { 909 struct tun_struct *tun = netdev_priv(dev); 910 911 tun->owner = -1; 912 tun->group = -1; 913 914 dev->ethtool_ops = &tun_ethtool_ops; 915 dev->destructor = tun_free_netdev; 916 } 917 918 /* Trivial set of netlink ops to allow deleting tun or tap 919 * device with netlink. 920 */ 921 static int tun_validate(struct nlattr *tb[], struct nlattr *data[]) 922 { 923 return -EINVAL; 924 } 925 926 static struct rtnl_link_ops tun_link_ops __read_mostly = { 927 .kind = DRV_NAME, 928 .priv_size = sizeof(struct tun_struct), 929 .setup = tun_setup, 930 .validate = tun_validate, 931 }; 932 933 static void tun_sock_write_space(struct sock *sk) 934 { 935 struct tun_struct *tun; 936 wait_queue_head_t *wqueue; 937 938 if (!sock_writeable(sk)) 939 return; 940 941 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags)) 942 return; 943 944 wqueue = sk_sleep(sk); 945 if (wqueue && waitqueue_active(wqueue)) 946 wake_up_interruptible_sync_poll(wqueue, POLLOUT | 947 POLLWRNORM | POLLWRBAND); 948 949 tun = tun_sk(sk)->tun; 950 kill_fasync(&tun->fasync, SIGIO, POLL_OUT); 951 } 952 953 static void tun_sock_destruct(struct sock *sk) 954 { 955 free_netdev(tun_sk(sk)->tun->dev); 956 } 957 958 static int tun_sendmsg(struct kiocb *iocb, struct socket *sock, 959 struct msghdr *m, size_t total_len) 960 { 961 struct tun_struct *tun = container_of(sock, struct tun_struct, socket); 962 return tun_get_user(tun, m->msg_iov, total_len, 963 m->msg_flags & MSG_DONTWAIT); 964 } 965 966 static int tun_recvmsg(struct kiocb *iocb, struct socket *sock, 967 struct msghdr *m, size_t total_len, 968 int flags) 969 { 970 struct tun_struct *tun = container_of(sock, struct tun_struct, socket); 971 int ret; 972 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC)) 973 return -EINVAL; 974 ret = tun_do_read(tun, iocb, m->msg_iov, total_len, 975 flags & MSG_DONTWAIT); 976 if (ret > total_len) { 977 m->msg_flags |= MSG_TRUNC; 978 ret = flags & MSG_TRUNC ? ret : total_len; 979 } 980 return ret; 981 } 982 983 static int tun_release(struct socket *sock) 984 { 985 if (sock->sk) 986 sock_put(sock->sk); 987 return 0; 988 } 989 990 /* Ops structure to mimic raw sockets with tun */ 991 static const struct proto_ops tun_socket_ops = { 992 .sendmsg = tun_sendmsg, 993 .recvmsg = tun_recvmsg, 994 .release = tun_release, 995 }; 996 997 static struct proto tun_proto = { 998 .name = "tun", 999 .owner = THIS_MODULE, 1000 .obj_size = sizeof(struct tun_sock), 1001 }; 1002 1003 static int tun_flags(struct tun_struct *tun) 1004 { 1005 int flags = 0; 1006 1007 if (tun->flags & TUN_TUN_DEV) 1008 flags |= IFF_TUN; 1009 else 1010 flags |= IFF_TAP; 1011 1012 if (tun->flags & TUN_NO_PI) 1013 flags |= IFF_NO_PI; 1014 1015 if (tun->flags & TUN_ONE_QUEUE) 1016 flags |= IFF_ONE_QUEUE; 1017 1018 if (tun->flags & TUN_VNET_HDR) 1019 flags |= IFF_VNET_HDR; 1020 1021 return flags; 1022 } 1023 1024 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr, 1025 char *buf) 1026 { 1027 struct tun_struct *tun = netdev_priv(to_net_dev(dev)); 1028 return sprintf(buf, "0x%x\n", tun_flags(tun)); 1029 } 1030 1031 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr, 1032 char *buf) 1033 { 1034 struct tun_struct *tun = netdev_priv(to_net_dev(dev)); 1035 return sprintf(buf, "%d\n", tun->owner); 1036 } 1037 1038 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr, 1039 char *buf) 1040 { 1041 struct tun_struct *tun = netdev_priv(to_net_dev(dev)); 1042 return sprintf(buf, "%d\n", tun->group); 1043 } 1044 1045 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL); 1046 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL); 1047 static DEVICE_ATTR(group, 0444, tun_show_group, NULL); 1048 1049 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) 1050 { 1051 struct sock *sk; 1052 struct tun_struct *tun; 1053 struct net_device *dev; 1054 int err; 1055 1056 dev = __dev_get_by_name(net, ifr->ifr_name); 1057 if (dev) { 1058 const struct cred *cred = current_cred(); 1059 1060 if (ifr->ifr_flags & IFF_TUN_EXCL) 1061 return -EBUSY; 1062 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops) 1063 tun = netdev_priv(dev); 1064 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops) 1065 tun = netdev_priv(dev); 1066 else 1067 return -EINVAL; 1068 1069 if (((tun->owner != -1 && cred->euid != tun->owner) || 1070 (tun->group != -1 && !in_egroup_p(tun->group))) && 1071 !capable(CAP_NET_ADMIN)) 1072 return -EPERM; 1073 err = security_tun_dev_attach(tun->socket.sk); 1074 if (err < 0) 1075 return err; 1076 1077 err = tun_attach(tun, file); 1078 if (err < 0) 1079 return err; 1080 } 1081 else { 1082 char *name; 1083 unsigned long flags = 0; 1084 1085 if (!capable(CAP_NET_ADMIN)) 1086 return -EPERM; 1087 err = security_tun_dev_create(); 1088 if (err < 0) 1089 return err; 1090 1091 /* Set dev type */ 1092 if (ifr->ifr_flags & IFF_TUN) { 1093 /* TUN device */ 1094 flags |= TUN_TUN_DEV; 1095 name = "tun%d"; 1096 } else if (ifr->ifr_flags & IFF_TAP) { 1097 /* TAP device */ 1098 flags |= TUN_TAP_DEV; 1099 name = "tap%d"; 1100 } else 1101 return -EINVAL; 1102 1103 if (*ifr->ifr_name) 1104 name = ifr->ifr_name; 1105 1106 dev = alloc_netdev(sizeof(struct tun_struct), name, 1107 tun_setup); 1108 if (!dev) 1109 return -ENOMEM; 1110 1111 dev_net_set(dev, net); 1112 dev->rtnl_link_ops = &tun_link_ops; 1113 1114 tun = netdev_priv(dev); 1115 tun->dev = dev; 1116 tun->flags = flags; 1117 tun->txflt.count = 0; 1118 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr); 1119 1120 err = -ENOMEM; 1121 sk = sk_alloc(&init_net, AF_UNSPEC, GFP_KERNEL, &tun_proto); 1122 if (!sk) 1123 goto err_free_dev; 1124 1125 sk_change_net(sk, net); 1126 tun->socket.wq = &tun->wq; 1127 init_waitqueue_head(&tun->wq.wait); 1128 tun->socket.ops = &tun_socket_ops; 1129 sock_init_data(&tun->socket, sk); 1130 sk->sk_write_space = tun_sock_write_space; 1131 sk->sk_sndbuf = INT_MAX; 1132 1133 tun_sk(sk)->tun = tun; 1134 1135 security_tun_dev_post_create(sk); 1136 1137 tun_net_init(dev); 1138 1139 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | 1140 TUN_USER_FEATURES; 1141 dev->features = dev->hw_features; 1142 1143 err = register_netdevice(tun->dev); 1144 if (err < 0) 1145 goto err_free_sk; 1146 1147 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) || 1148 device_create_file(&tun->dev->dev, &dev_attr_owner) || 1149 device_create_file(&tun->dev->dev, &dev_attr_group)) 1150 pr_err("Failed to create tun sysfs files\n"); 1151 1152 sk->sk_destruct = tun_sock_destruct; 1153 1154 err = tun_attach(tun, file); 1155 if (err < 0) 1156 goto failed; 1157 } 1158 1159 tun_debug(KERN_INFO, tun, "tun_set_iff\n"); 1160 1161 if (ifr->ifr_flags & IFF_NO_PI) 1162 tun->flags |= TUN_NO_PI; 1163 else 1164 tun->flags &= ~TUN_NO_PI; 1165 1166 if (ifr->ifr_flags & IFF_ONE_QUEUE) 1167 tun->flags |= TUN_ONE_QUEUE; 1168 else 1169 tun->flags &= ~TUN_ONE_QUEUE; 1170 1171 if (ifr->ifr_flags & IFF_VNET_HDR) 1172 tun->flags |= TUN_VNET_HDR; 1173 else 1174 tun->flags &= ~TUN_VNET_HDR; 1175 1176 /* Make sure persistent devices do not get stuck in 1177 * xoff state. 1178 */ 1179 if (netif_running(tun->dev)) 1180 netif_wake_queue(tun->dev); 1181 1182 strcpy(ifr->ifr_name, tun->dev->name); 1183 return 0; 1184 1185 err_free_sk: 1186 tun_free_netdev(dev); 1187 err_free_dev: 1188 free_netdev(dev); 1189 failed: 1190 return err; 1191 } 1192 1193 static int tun_get_iff(struct net *net, struct tun_struct *tun, 1194 struct ifreq *ifr) 1195 { 1196 tun_debug(KERN_INFO, tun, "tun_get_iff\n"); 1197 1198 strcpy(ifr->ifr_name, tun->dev->name); 1199 1200 ifr->ifr_flags = tun_flags(tun); 1201 1202 return 0; 1203 } 1204 1205 /* This is like a cut-down ethtool ops, except done via tun fd so no 1206 * privs required. */ 1207 static int set_offload(struct tun_struct *tun, unsigned long arg) 1208 { 1209 netdev_features_t features = 0; 1210 1211 if (arg & TUN_F_CSUM) { 1212 features |= NETIF_F_HW_CSUM; 1213 arg &= ~TUN_F_CSUM; 1214 1215 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) { 1216 if (arg & TUN_F_TSO_ECN) { 1217 features |= NETIF_F_TSO_ECN; 1218 arg &= ~TUN_F_TSO_ECN; 1219 } 1220 if (arg & TUN_F_TSO4) 1221 features |= NETIF_F_TSO; 1222 if (arg & TUN_F_TSO6) 1223 features |= NETIF_F_TSO6; 1224 arg &= ~(TUN_F_TSO4|TUN_F_TSO6); 1225 } 1226 1227 if (arg & TUN_F_UFO) { 1228 features |= NETIF_F_UFO; 1229 arg &= ~TUN_F_UFO; 1230 } 1231 } 1232 1233 /* This gives the user a way to test for new features in future by 1234 * trying to set them. */ 1235 if (arg) 1236 return -EINVAL; 1237 1238 tun->set_features = features; 1239 netdev_update_features(tun->dev); 1240 1241 return 0; 1242 } 1243 1244 static long __tun_chr_ioctl(struct file *file, unsigned int cmd, 1245 unsigned long arg, int ifreq_len) 1246 { 1247 struct tun_file *tfile = file->private_data; 1248 struct tun_struct *tun; 1249 void __user* argp = (void __user*)arg; 1250 struct sock_fprog fprog; 1251 struct ifreq ifr; 1252 int sndbuf; 1253 int vnet_hdr_sz; 1254 int ret; 1255 1256 if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89) 1257 if (copy_from_user(&ifr, argp, ifreq_len)) 1258 return -EFAULT; 1259 1260 if (cmd == TUNGETFEATURES) { 1261 /* Currently this just means: "what IFF flags are valid?". 1262 * This is needed because we never checked for invalid flags on 1263 * TUNSETIFF. */ 1264 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE | 1265 IFF_VNET_HDR, 1266 (unsigned int __user*)argp); 1267 } 1268 1269 rtnl_lock(); 1270 1271 tun = __tun_get(tfile); 1272 if (cmd == TUNSETIFF && !tun) { 1273 ifr.ifr_name[IFNAMSIZ-1] = '\0'; 1274 1275 ret = tun_set_iff(tfile->net, file, &ifr); 1276 1277 if (ret) 1278 goto unlock; 1279 1280 if (copy_to_user(argp, &ifr, ifreq_len)) 1281 ret = -EFAULT; 1282 goto unlock; 1283 } 1284 1285 ret = -EBADFD; 1286 if (!tun) 1287 goto unlock; 1288 1289 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %d\n", cmd); 1290 1291 ret = 0; 1292 switch (cmd) { 1293 case TUNGETIFF: 1294 ret = tun_get_iff(current->nsproxy->net_ns, tun, &ifr); 1295 if (ret) 1296 break; 1297 1298 if (copy_to_user(argp, &ifr, ifreq_len)) 1299 ret = -EFAULT; 1300 break; 1301 1302 case TUNSETNOCSUM: 1303 /* Disable/Enable checksum */ 1304 1305 /* [unimplemented] */ 1306 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n", 1307 arg ? "disabled" : "enabled"); 1308 break; 1309 1310 case TUNSETPERSIST: 1311 /* Disable/Enable persist mode */ 1312 if (arg) 1313 tun->flags |= TUN_PERSIST; 1314 else 1315 tun->flags &= ~TUN_PERSIST; 1316 1317 tun_debug(KERN_INFO, tun, "persist %s\n", 1318 arg ? "enabled" : "disabled"); 1319 break; 1320 1321 case TUNSETOWNER: 1322 /* Set owner of the device */ 1323 tun->owner = (uid_t) arg; 1324 1325 tun_debug(KERN_INFO, tun, "owner set to %d\n", tun->owner); 1326 break; 1327 1328 case TUNSETGROUP: 1329 /* Set group of the device */ 1330 tun->group= (gid_t) arg; 1331 1332 tun_debug(KERN_INFO, tun, "group set to %d\n", tun->group); 1333 break; 1334 1335 case TUNSETLINK: 1336 /* Only allow setting the type when the interface is down */ 1337 if (tun->dev->flags & IFF_UP) { 1338 tun_debug(KERN_INFO, tun, 1339 "Linktype set failed because interface is up\n"); 1340 ret = -EBUSY; 1341 } else { 1342 tun->dev->type = (int) arg; 1343 tun_debug(KERN_INFO, tun, "linktype set to %d\n", 1344 tun->dev->type); 1345 ret = 0; 1346 } 1347 break; 1348 1349 #ifdef TUN_DEBUG 1350 case TUNSETDEBUG: 1351 tun->debug = arg; 1352 break; 1353 #endif 1354 case TUNSETOFFLOAD: 1355 ret = set_offload(tun, arg); 1356 break; 1357 1358 case TUNSETTXFILTER: 1359 /* Can be set only for TAPs */ 1360 ret = -EINVAL; 1361 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV) 1362 break; 1363 ret = update_filter(&tun->txflt, (void __user *)arg); 1364 break; 1365 1366 case SIOCGIFHWADDR: 1367 /* Get hw address */ 1368 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN); 1369 ifr.ifr_hwaddr.sa_family = tun->dev->type; 1370 if (copy_to_user(argp, &ifr, ifreq_len)) 1371 ret = -EFAULT; 1372 break; 1373 1374 case SIOCSIFHWADDR: 1375 /* Set hw address */ 1376 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n", 1377 ifr.ifr_hwaddr.sa_data); 1378 1379 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr); 1380 break; 1381 1382 case TUNGETSNDBUF: 1383 sndbuf = tun->socket.sk->sk_sndbuf; 1384 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf))) 1385 ret = -EFAULT; 1386 break; 1387 1388 case TUNSETSNDBUF: 1389 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) { 1390 ret = -EFAULT; 1391 break; 1392 } 1393 1394 tun->socket.sk->sk_sndbuf = sndbuf; 1395 break; 1396 1397 case TUNGETVNETHDRSZ: 1398 vnet_hdr_sz = tun->vnet_hdr_sz; 1399 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz))) 1400 ret = -EFAULT; 1401 break; 1402 1403 case TUNSETVNETHDRSZ: 1404 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) { 1405 ret = -EFAULT; 1406 break; 1407 } 1408 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) { 1409 ret = -EINVAL; 1410 break; 1411 } 1412 1413 tun->vnet_hdr_sz = vnet_hdr_sz; 1414 break; 1415 1416 case TUNATTACHFILTER: 1417 /* Can be set only for TAPs */ 1418 ret = -EINVAL; 1419 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV) 1420 break; 1421 ret = -EFAULT; 1422 if (copy_from_user(&fprog, argp, sizeof(fprog))) 1423 break; 1424 1425 ret = sk_attach_filter(&fprog, tun->socket.sk); 1426 break; 1427 1428 case TUNDETACHFILTER: 1429 /* Can be set only for TAPs */ 1430 ret = -EINVAL; 1431 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV) 1432 break; 1433 ret = sk_detach_filter(tun->socket.sk); 1434 break; 1435 1436 default: 1437 ret = -EINVAL; 1438 break; 1439 } 1440 1441 unlock: 1442 rtnl_unlock(); 1443 if (tun) 1444 tun_put(tun); 1445 return ret; 1446 } 1447 1448 static long tun_chr_ioctl(struct file *file, 1449 unsigned int cmd, unsigned long arg) 1450 { 1451 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq)); 1452 } 1453 1454 #ifdef CONFIG_COMPAT 1455 static long tun_chr_compat_ioctl(struct file *file, 1456 unsigned int cmd, unsigned long arg) 1457 { 1458 switch (cmd) { 1459 case TUNSETIFF: 1460 case TUNGETIFF: 1461 case TUNSETTXFILTER: 1462 case TUNGETSNDBUF: 1463 case TUNSETSNDBUF: 1464 case SIOCGIFHWADDR: 1465 case SIOCSIFHWADDR: 1466 arg = (unsigned long)compat_ptr(arg); 1467 break; 1468 default: 1469 arg = (compat_ulong_t)arg; 1470 break; 1471 } 1472 1473 /* 1474 * compat_ifreq is shorter than ifreq, so we must not access beyond 1475 * the end of that structure. All fields that are used in this 1476 * driver are compatible though, we don't need to convert the 1477 * contents. 1478 */ 1479 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq)); 1480 } 1481 #endif /* CONFIG_COMPAT */ 1482 1483 static int tun_chr_fasync(int fd, struct file *file, int on) 1484 { 1485 struct tun_struct *tun = tun_get(file); 1486 int ret; 1487 1488 if (!tun) 1489 return -EBADFD; 1490 1491 tun_debug(KERN_INFO, tun, "tun_chr_fasync %d\n", on); 1492 1493 if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0) 1494 goto out; 1495 1496 if (on) { 1497 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0); 1498 if (ret) 1499 goto out; 1500 tun->flags |= TUN_FASYNC; 1501 } else 1502 tun->flags &= ~TUN_FASYNC; 1503 ret = 0; 1504 out: 1505 tun_put(tun); 1506 return ret; 1507 } 1508 1509 static int tun_chr_open(struct inode *inode, struct file * file) 1510 { 1511 struct tun_file *tfile; 1512 1513 DBG1(KERN_INFO, "tunX: tun_chr_open\n"); 1514 1515 tfile = kmalloc(sizeof(*tfile), GFP_KERNEL); 1516 if (!tfile) 1517 return -ENOMEM; 1518 atomic_set(&tfile->count, 0); 1519 tfile->tun = NULL; 1520 tfile->net = get_net(current->nsproxy->net_ns); 1521 file->private_data = tfile; 1522 return 0; 1523 } 1524 1525 static int tun_chr_close(struct inode *inode, struct file *file) 1526 { 1527 struct tun_file *tfile = file->private_data; 1528 struct tun_struct *tun; 1529 1530 tun = __tun_get(tfile); 1531 if (tun) { 1532 struct net_device *dev = tun->dev; 1533 1534 tun_debug(KERN_INFO, tun, "tun_chr_close\n"); 1535 1536 __tun_detach(tun); 1537 1538 /* If desirable, unregister the netdevice. */ 1539 if (!(tun->flags & TUN_PERSIST)) { 1540 rtnl_lock(); 1541 if (dev->reg_state == NETREG_REGISTERED) 1542 unregister_netdevice(dev); 1543 rtnl_unlock(); 1544 } 1545 } 1546 1547 tun = tfile->tun; 1548 if (tun) 1549 sock_put(tun->socket.sk); 1550 1551 put_net(tfile->net); 1552 kfree(tfile); 1553 1554 return 0; 1555 } 1556 1557 static const struct file_operations tun_fops = { 1558 .owner = THIS_MODULE, 1559 .llseek = no_llseek, 1560 .read = do_sync_read, 1561 .aio_read = tun_chr_aio_read, 1562 .write = do_sync_write, 1563 .aio_write = tun_chr_aio_write, 1564 .poll = tun_chr_poll, 1565 .unlocked_ioctl = tun_chr_ioctl, 1566 #ifdef CONFIG_COMPAT 1567 .compat_ioctl = tun_chr_compat_ioctl, 1568 #endif 1569 .open = tun_chr_open, 1570 .release = tun_chr_close, 1571 .fasync = tun_chr_fasync 1572 }; 1573 1574 static struct miscdevice tun_miscdev = { 1575 .minor = TUN_MINOR, 1576 .name = "tun", 1577 .nodename = "net/tun", 1578 .fops = &tun_fops, 1579 }; 1580 1581 /* ethtool interface */ 1582 1583 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd) 1584 { 1585 cmd->supported = 0; 1586 cmd->advertising = 0; 1587 ethtool_cmd_speed_set(cmd, SPEED_10); 1588 cmd->duplex = DUPLEX_FULL; 1589 cmd->port = PORT_TP; 1590 cmd->phy_address = 0; 1591 cmd->transceiver = XCVR_INTERNAL; 1592 cmd->autoneg = AUTONEG_DISABLE; 1593 cmd->maxtxpkt = 0; 1594 cmd->maxrxpkt = 0; 1595 return 0; 1596 } 1597 1598 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info) 1599 { 1600 struct tun_struct *tun = netdev_priv(dev); 1601 1602 strlcpy(info->driver, DRV_NAME, sizeof(info->driver)); 1603 strlcpy(info->version, DRV_VERSION, sizeof(info->version)); 1604 1605 switch (tun->flags & TUN_TYPE_MASK) { 1606 case TUN_TUN_DEV: 1607 strlcpy(info->bus_info, "tun", sizeof(info->bus_info)); 1608 break; 1609 case TUN_TAP_DEV: 1610 strlcpy(info->bus_info, "tap", sizeof(info->bus_info)); 1611 break; 1612 } 1613 } 1614 1615 static u32 tun_get_msglevel(struct net_device *dev) 1616 { 1617 #ifdef TUN_DEBUG 1618 struct tun_struct *tun = netdev_priv(dev); 1619 return tun->debug; 1620 #else 1621 return -EOPNOTSUPP; 1622 #endif 1623 } 1624 1625 static void tun_set_msglevel(struct net_device *dev, u32 value) 1626 { 1627 #ifdef TUN_DEBUG 1628 struct tun_struct *tun = netdev_priv(dev); 1629 tun->debug = value; 1630 #endif 1631 } 1632 1633 static const struct ethtool_ops tun_ethtool_ops = { 1634 .get_settings = tun_get_settings, 1635 .get_drvinfo = tun_get_drvinfo, 1636 .get_msglevel = tun_get_msglevel, 1637 .set_msglevel = tun_set_msglevel, 1638 .get_link = ethtool_op_get_link, 1639 }; 1640 1641 1642 static int __init tun_init(void) 1643 { 1644 int ret = 0; 1645 1646 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION); 1647 pr_info("%s\n", DRV_COPYRIGHT); 1648 1649 ret = rtnl_link_register(&tun_link_ops); 1650 if (ret) { 1651 pr_err("Can't register link_ops\n"); 1652 goto err_linkops; 1653 } 1654 1655 ret = misc_register(&tun_miscdev); 1656 if (ret) { 1657 pr_err("Can't register misc device %d\n", TUN_MINOR); 1658 goto err_misc; 1659 } 1660 return 0; 1661 err_misc: 1662 rtnl_link_unregister(&tun_link_ops); 1663 err_linkops: 1664 return ret; 1665 } 1666 1667 static void tun_cleanup(void) 1668 { 1669 misc_deregister(&tun_miscdev); 1670 rtnl_link_unregister(&tun_link_ops); 1671 } 1672 1673 /* Get an underlying socket object from tun file. Returns error unless file is 1674 * attached to a device. The returned object works like a packet socket, it 1675 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for 1676 * holding a reference to the file for as long as the socket is in use. */ 1677 struct socket *tun_get_socket(struct file *file) 1678 { 1679 struct tun_struct *tun; 1680 if (file->f_op != &tun_fops) 1681 return ERR_PTR(-EINVAL); 1682 tun = tun_get(file); 1683 if (!tun) 1684 return ERR_PTR(-EBADFD); 1685 tun_put(tun); 1686 return &tun->socket; 1687 } 1688 EXPORT_SYMBOL_GPL(tun_get_socket); 1689 1690 module_init(tun_init); 1691 module_exit(tun_cleanup); 1692 MODULE_DESCRIPTION(DRV_DESCRIPTION); 1693 MODULE_AUTHOR(DRV_COPYRIGHT); 1694 MODULE_LICENSE("GPL"); 1695 MODULE_ALIAS_MISCDEV(TUN_MINOR); 1696 MODULE_ALIAS("devname:net/tun"); 1697