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