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