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