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 DRV_NAME "tun" 38 #define DRV_VERSION "1.6" 39 #define DRV_DESCRIPTION "Universal TUN/TAP device driver" 40 #define DRV_COPYRIGHT "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>" 41 42 #include <linux/module.h> 43 #include <linux/errno.h> 44 #include <linux/kernel.h> 45 #include <linux/major.h> 46 #include <linux/slab.h> 47 #include <linux/poll.h> 48 #include <linux/fcntl.h> 49 #include <linux/init.h> 50 #include <linux/skbuff.h> 51 #include <linux/netdevice.h> 52 #include <linux/etherdevice.h> 53 #include <linux/miscdevice.h> 54 #include <linux/ethtool.h> 55 #include <linux/rtnetlink.h> 56 #include <linux/compat.h> 57 #include <linux/if.h> 58 #include <linux/if_arp.h> 59 #include <linux/if_ether.h> 60 #include <linux/if_tun.h> 61 #include <linux/crc32.h> 62 #include <linux/nsproxy.h> 63 #include <linux/virtio_net.h> 64 #include <linux/rcupdate.h> 65 #include <net/net_namespace.h> 66 #include <net/netns/generic.h> 67 #include <net/rtnetlink.h> 68 #include <net/sock.h> 69 70 #include <asm/system.h> 71 #include <asm/uaccess.h> 72 73 /* Uncomment to enable debugging */ 74 /* #define TUN_DEBUG 1 */ 75 76 #ifdef TUN_DEBUG 77 static int debug; 78 79 #define DBG if(tun->debug)printk 80 #define DBG1 if(debug==2)printk 81 #else 82 #define DBG( a... ) 83 #define DBG1( a... ) 84 #endif 85 86 #define FLT_EXACT_COUNT 8 87 struct tap_filter { 88 unsigned int count; /* Number of addrs. Zero means disabled */ 89 u32 mask[2]; /* Mask of the hashed addrs */ 90 unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN]; 91 }; 92 93 struct tun_file { 94 atomic_t count; 95 struct tun_struct *tun; 96 struct net *net; 97 }; 98 99 struct tun_sock; 100 101 struct tun_struct { 102 struct tun_file *tfile; 103 unsigned int flags; 104 uid_t owner; 105 gid_t group; 106 107 struct net_device *dev; 108 struct fasync_struct *fasync; 109 110 struct tap_filter txflt; 111 struct socket socket; 112 113 #ifdef TUN_DEBUG 114 int debug; 115 #endif 116 }; 117 118 struct tun_sock { 119 struct sock sk; 120 struct tun_struct *tun; 121 }; 122 123 static inline struct tun_sock *tun_sk(struct sock *sk) 124 { 125 return container_of(sk, struct tun_sock, sk); 126 } 127 128 static int tun_attach(struct tun_struct *tun, struct file *file) 129 { 130 struct tun_file *tfile = file->private_data; 131 int err; 132 133 ASSERT_RTNL(); 134 135 netif_tx_lock_bh(tun->dev); 136 137 err = -EINVAL; 138 if (tfile->tun) 139 goto out; 140 141 err = -EBUSY; 142 if (tun->tfile) 143 goto out; 144 145 err = 0; 146 tfile->tun = tun; 147 tun->tfile = tfile; 148 tun->socket.file = file; 149 dev_hold(tun->dev); 150 sock_hold(tun->socket.sk); 151 atomic_inc(&tfile->count); 152 153 out: 154 netif_tx_unlock_bh(tun->dev); 155 return err; 156 } 157 158 static void __tun_detach(struct tun_struct *tun) 159 { 160 /* Detach from net device */ 161 netif_tx_lock_bh(tun->dev); 162 tun->tfile = NULL; 163 tun->socket.file = NULL; 164 netif_tx_unlock_bh(tun->dev); 165 166 /* Drop read queue */ 167 skb_queue_purge(&tun->socket.sk->sk_receive_queue); 168 169 /* Drop the extra count on the net device */ 170 dev_put(tun->dev); 171 } 172 173 static void tun_detach(struct tun_struct *tun) 174 { 175 rtnl_lock(); 176 __tun_detach(tun); 177 rtnl_unlock(); 178 } 179 180 static struct tun_struct *__tun_get(struct tun_file *tfile) 181 { 182 struct tun_struct *tun = NULL; 183 184 if (atomic_inc_not_zero(&tfile->count)) 185 tun = tfile->tun; 186 187 return tun; 188 } 189 190 static struct tun_struct *tun_get(struct file *file) 191 { 192 return __tun_get(file->private_data); 193 } 194 195 static void tun_put(struct tun_struct *tun) 196 { 197 struct tun_file *tfile = tun->tfile; 198 199 if (atomic_dec_and_test(&tfile->count)) 200 tun_detach(tfile->tun); 201 } 202 203 /* TAP filterting */ 204 static void addr_hash_set(u32 *mask, const u8 *addr) 205 { 206 int n = ether_crc(ETH_ALEN, addr) >> 26; 207 mask[n >> 5] |= (1 << (n & 31)); 208 } 209 210 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr) 211 { 212 int n = ether_crc(ETH_ALEN, addr) >> 26; 213 return mask[n >> 5] & (1 << (n & 31)); 214 } 215 216 static int update_filter(struct tap_filter *filter, void __user *arg) 217 { 218 struct { u8 u[ETH_ALEN]; } *addr; 219 struct tun_filter uf; 220 int err, alen, n, nexact; 221 222 if (copy_from_user(&uf, arg, sizeof(uf))) 223 return -EFAULT; 224 225 if (!uf.count) { 226 /* Disabled */ 227 filter->count = 0; 228 return 0; 229 } 230 231 alen = ETH_ALEN * uf.count; 232 addr = kmalloc(alen, GFP_KERNEL); 233 if (!addr) 234 return -ENOMEM; 235 236 if (copy_from_user(addr, arg + sizeof(uf), alen)) { 237 err = -EFAULT; 238 goto done; 239 } 240 241 /* The filter is updated without holding any locks. Which is 242 * perfectly safe. We disable it first and in the worst 243 * case we'll accept a few undesired packets. */ 244 filter->count = 0; 245 wmb(); 246 247 /* Use first set of addresses as an exact filter */ 248 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++) 249 memcpy(filter->addr[n], addr[n].u, ETH_ALEN); 250 251 nexact = n; 252 253 /* Remaining multicast addresses are hashed, 254 * unicast will leave the filter disabled. */ 255 memset(filter->mask, 0, sizeof(filter->mask)); 256 for (; n < uf.count; n++) { 257 if (!is_multicast_ether_addr(addr[n].u)) { 258 err = 0; /* no filter */ 259 goto done; 260 } 261 addr_hash_set(filter->mask, addr[n].u); 262 } 263 264 /* For ALLMULTI just set the mask to all ones. 265 * This overrides the mask populated above. */ 266 if ((uf.flags & TUN_FLT_ALLMULTI)) 267 memset(filter->mask, ~0, sizeof(filter->mask)); 268 269 /* Now enable the filter */ 270 wmb(); 271 filter->count = nexact; 272 273 /* Return the number of exact filters */ 274 err = nexact; 275 276 done: 277 kfree(addr); 278 return err; 279 } 280 281 /* Returns: 0 - drop, !=0 - accept */ 282 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb) 283 { 284 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect 285 * at this point. */ 286 struct ethhdr *eh = (struct ethhdr *) skb->data; 287 int i; 288 289 /* Exact match */ 290 for (i = 0; i < filter->count; i++) 291 if (!compare_ether_addr(eh->h_dest, filter->addr[i])) 292 return 1; 293 294 /* Inexact match (multicast only) */ 295 if (is_multicast_ether_addr(eh->h_dest)) 296 return addr_hash_test(filter->mask, eh->h_dest); 297 298 return 0; 299 } 300 301 /* 302 * Checks whether the packet is accepted or not. 303 * Returns: 0 - drop, !=0 - accept 304 */ 305 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb) 306 { 307 if (!filter->count) 308 return 1; 309 310 return run_filter(filter, skb); 311 } 312 313 /* Network device part of the driver */ 314 315 static const struct ethtool_ops tun_ethtool_ops; 316 317 /* Net device detach from fd. */ 318 static void tun_net_uninit(struct net_device *dev) 319 { 320 struct tun_struct *tun = netdev_priv(dev); 321 struct tun_file *tfile = tun->tfile; 322 323 /* Inform the methods they need to stop using the dev. 324 */ 325 if (tfile) { 326 wake_up_all(&tun->socket.wait); 327 if (atomic_dec_and_test(&tfile->count)) 328 __tun_detach(tun); 329 } 330 } 331 332 static void tun_free_netdev(struct net_device *dev) 333 { 334 struct tun_struct *tun = netdev_priv(dev); 335 336 sock_put(tun->socket.sk); 337 } 338 339 /* Net device open. */ 340 static int tun_net_open(struct net_device *dev) 341 { 342 netif_start_queue(dev); 343 return 0; 344 } 345 346 /* Net device close. */ 347 static int tun_net_close(struct net_device *dev) 348 { 349 netif_stop_queue(dev); 350 return 0; 351 } 352 353 /* Net device start xmit */ 354 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev) 355 { 356 struct tun_struct *tun = netdev_priv(dev); 357 358 DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len); 359 360 /* Drop packet if interface is not attached */ 361 if (!tun->tfile) 362 goto drop; 363 364 /* Drop if the filter does not like it. 365 * This is a noop if the filter is disabled. 366 * Filter can be enabled only for the TAP devices. */ 367 if (!check_filter(&tun->txflt, skb)) 368 goto drop; 369 370 if (tun->socket.sk->sk_filter && 371 sk_filter(tun->socket.sk, skb)) 372 goto drop; 373 374 if (skb_queue_len(&tun->socket.sk->sk_receive_queue) >= dev->tx_queue_len) { 375 if (!(tun->flags & TUN_ONE_QUEUE)) { 376 /* Normal queueing mode. */ 377 /* Packet scheduler handles dropping of further packets. */ 378 netif_stop_queue(dev); 379 380 /* We won't see all dropped packets individually, so overrun 381 * error is more appropriate. */ 382 dev->stats.tx_fifo_errors++; 383 } else { 384 /* Single queue mode. 385 * Driver handles dropping of all packets itself. */ 386 goto drop; 387 } 388 } 389 390 /* Enqueue packet */ 391 skb_queue_tail(&tun->socket.sk->sk_receive_queue, skb); 392 dev->trans_start = jiffies; 393 394 /* Notify and wake up reader process */ 395 if (tun->flags & TUN_FASYNC) 396 kill_fasync(&tun->fasync, SIGIO, POLL_IN); 397 wake_up_interruptible_poll(&tun->socket.wait, POLLIN | 398 POLLRDNORM | POLLRDBAND); 399 return NETDEV_TX_OK; 400 401 drop: 402 dev->stats.tx_dropped++; 403 kfree_skb(skb); 404 return NETDEV_TX_OK; 405 } 406 407 static void tun_net_mclist(struct net_device *dev) 408 { 409 /* 410 * This callback is supposed to deal with mc filter in 411 * _rx_ path and has nothing to do with the _tx_ path. 412 * In rx path we always accept everything userspace gives us. 413 */ 414 return; 415 } 416 417 #define MIN_MTU 68 418 #define MAX_MTU 65535 419 420 static int 421 tun_net_change_mtu(struct net_device *dev, int new_mtu) 422 { 423 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU) 424 return -EINVAL; 425 dev->mtu = new_mtu; 426 return 0; 427 } 428 429 static const struct net_device_ops tun_netdev_ops = { 430 .ndo_uninit = tun_net_uninit, 431 .ndo_open = tun_net_open, 432 .ndo_stop = tun_net_close, 433 .ndo_start_xmit = tun_net_xmit, 434 .ndo_change_mtu = tun_net_change_mtu, 435 }; 436 437 static const struct net_device_ops tap_netdev_ops = { 438 .ndo_uninit = tun_net_uninit, 439 .ndo_open = tun_net_open, 440 .ndo_stop = tun_net_close, 441 .ndo_start_xmit = tun_net_xmit, 442 .ndo_change_mtu = tun_net_change_mtu, 443 .ndo_set_multicast_list = tun_net_mclist, 444 .ndo_set_mac_address = eth_mac_addr, 445 .ndo_validate_addr = eth_validate_addr, 446 }; 447 448 /* Initialize net device. */ 449 static void tun_net_init(struct net_device *dev) 450 { 451 struct tun_struct *tun = netdev_priv(dev); 452 453 switch (tun->flags & TUN_TYPE_MASK) { 454 case TUN_TUN_DEV: 455 dev->netdev_ops = &tun_netdev_ops; 456 457 /* Point-to-Point TUN Device */ 458 dev->hard_header_len = 0; 459 dev->addr_len = 0; 460 dev->mtu = 1500; 461 462 /* Zero header length */ 463 dev->type = ARPHRD_NONE; 464 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 465 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */ 466 break; 467 468 case TUN_TAP_DEV: 469 dev->netdev_ops = &tap_netdev_ops; 470 /* Ethernet TAP Device */ 471 ether_setup(dev); 472 473 random_ether_addr(dev->dev_addr); 474 475 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */ 476 break; 477 } 478 } 479 480 /* Character device part */ 481 482 /* Poll */ 483 static unsigned int tun_chr_poll(struct file *file, poll_table * wait) 484 { 485 struct tun_file *tfile = file->private_data; 486 struct tun_struct *tun = __tun_get(tfile); 487 struct sock *sk; 488 unsigned int mask = 0; 489 490 if (!tun) 491 return POLLERR; 492 493 sk = tun->socket.sk; 494 495 DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name); 496 497 poll_wait(file, &tun->socket.wait, wait); 498 499 if (!skb_queue_empty(&sk->sk_receive_queue)) 500 mask |= POLLIN | POLLRDNORM; 501 502 if (sock_writeable(sk) || 503 (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) && 504 sock_writeable(sk))) 505 mask |= POLLOUT | POLLWRNORM; 506 507 if (tun->dev->reg_state != NETREG_REGISTERED) 508 mask = POLLERR; 509 510 tun_put(tun); 511 return mask; 512 } 513 514 /* prepad is the amount to reserve at front. len is length after that. 515 * linear is a hint as to how much to copy (usually headers). */ 516 static inline struct sk_buff *tun_alloc_skb(struct tun_struct *tun, 517 size_t prepad, size_t len, 518 size_t linear, int noblock) 519 { 520 struct sock *sk = tun->socket.sk; 521 struct sk_buff *skb; 522 int err; 523 524 /* Under a page? Don't bother with paged skb. */ 525 if (prepad + len < PAGE_SIZE || !linear) 526 linear = len; 527 528 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 529 &err); 530 if (!skb) 531 return ERR_PTR(err); 532 533 skb_reserve(skb, prepad); 534 skb_put(skb, linear); 535 skb->data_len = len - linear; 536 skb->len += len - linear; 537 538 return skb; 539 } 540 541 /* Get packet from user space buffer */ 542 static __inline__ ssize_t tun_get_user(struct tun_struct *tun, 543 const struct iovec *iv, size_t count, 544 int noblock) 545 { 546 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) }; 547 struct sk_buff *skb; 548 size_t len = count, align = 0; 549 struct virtio_net_hdr gso = { 0 }; 550 int offset = 0; 551 552 if (!(tun->flags & TUN_NO_PI)) { 553 if ((len -= sizeof(pi)) > count) 554 return -EINVAL; 555 556 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi))) 557 return -EFAULT; 558 offset += sizeof(pi); 559 } 560 561 if (tun->flags & TUN_VNET_HDR) { 562 if ((len -= sizeof(gso)) > count) 563 return -EINVAL; 564 565 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso))) 566 return -EFAULT; 567 568 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 569 gso.csum_start + gso.csum_offset + 2 > gso.hdr_len) 570 gso.hdr_len = gso.csum_start + gso.csum_offset + 2; 571 572 if (gso.hdr_len > len) 573 return -EINVAL; 574 offset += sizeof(gso); 575 } 576 577 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) { 578 align = NET_IP_ALIGN; 579 if (unlikely(len < ETH_HLEN || 580 (gso.hdr_len && gso.hdr_len < ETH_HLEN))) 581 return -EINVAL; 582 } 583 584 skb = tun_alloc_skb(tun, align, len, gso.hdr_len, noblock); 585 if (IS_ERR(skb)) { 586 if (PTR_ERR(skb) != -EAGAIN) 587 tun->dev->stats.rx_dropped++; 588 return PTR_ERR(skb); 589 } 590 591 if (skb_copy_datagram_from_iovec(skb, 0, iv, offset, len)) { 592 tun->dev->stats.rx_dropped++; 593 kfree_skb(skb); 594 return -EFAULT; 595 } 596 597 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 598 if (!skb_partial_csum_set(skb, gso.csum_start, 599 gso.csum_offset)) { 600 tun->dev->stats.rx_frame_errors++; 601 kfree_skb(skb); 602 return -EINVAL; 603 } 604 } else if (tun->flags & TUN_NOCHECKSUM) 605 skb->ip_summed = CHECKSUM_UNNECESSARY; 606 607 switch (tun->flags & TUN_TYPE_MASK) { 608 case TUN_TUN_DEV: 609 if (tun->flags & TUN_NO_PI) { 610 switch (skb->data[0] & 0xf0) { 611 case 0x40: 612 pi.proto = htons(ETH_P_IP); 613 break; 614 case 0x60: 615 pi.proto = htons(ETH_P_IPV6); 616 break; 617 default: 618 tun->dev->stats.rx_dropped++; 619 kfree_skb(skb); 620 return -EINVAL; 621 } 622 } 623 624 skb_reset_mac_header(skb); 625 skb->protocol = pi.proto; 626 skb->dev = tun->dev; 627 break; 628 case TUN_TAP_DEV: 629 skb->protocol = eth_type_trans(skb, tun->dev); 630 break; 631 }; 632 633 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 634 pr_debug("GSO!\n"); 635 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 636 case VIRTIO_NET_HDR_GSO_TCPV4: 637 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; 638 break; 639 case VIRTIO_NET_HDR_GSO_TCPV6: 640 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; 641 break; 642 case VIRTIO_NET_HDR_GSO_UDP: 643 skb_shinfo(skb)->gso_type = SKB_GSO_UDP; 644 break; 645 default: 646 tun->dev->stats.rx_frame_errors++; 647 kfree_skb(skb); 648 return -EINVAL; 649 } 650 651 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN) 652 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; 653 654 skb_shinfo(skb)->gso_size = gso.gso_size; 655 if (skb_shinfo(skb)->gso_size == 0) { 656 tun->dev->stats.rx_frame_errors++; 657 kfree_skb(skb); 658 return -EINVAL; 659 } 660 661 /* Header must be checked, and gso_segs computed. */ 662 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 663 skb_shinfo(skb)->gso_segs = 0; 664 } 665 666 netif_rx_ni(skb); 667 668 tun->dev->stats.rx_packets++; 669 tun->dev->stats.rx_bytes += len; 670 671 return count; 672 } 673 674 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv, 675 unsigned long count, loff_t pos) 676 { 677 struct file *file = iocb->ki_filp; 678 struct tun_struct *tun = tun_get(file); 679 ssize_t result; 680 681 if (!tun) 682 return -EBADFD; 683 684 DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count); 685 686 result = tun_get_user(tun, iv, iov_length(iv, count), 687 file->f_flags & O_NONBLOCK); 688 689 tun_put(tun); 690 return result; 691 } 692 693 /* Put packet to the user space buffer */ 694 static __inline__ ssize_t tun_put_user(struct tun_struct *tun, 695 struct sk_buff *skb, 696 const struct iovec *iv, int len) 697 { 698 struct tun_pi pi = { 0, skb->protocol }; 699 ssize_t total = 0; 700 701 if (!(tun->flags & TUN_NO_PI)) { 702 if ((len -= sizeof(pi)) < 0) 703 return -EINVAL; 704 705 if (len < skb->len) { 706 /* Packet will be striped */ 707 pi.flags |= TUN_PKT_STRIP; 708 } 709 710 if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi))) 711 return -EFAULT; 712 total += sizeof(pi); 713 } 714 715 if (tun->flags & TUN_VNET_HDR) { 716 struct virtio_net_hdr gso = { 0 }; /* no info leak */ 717 if ((len -= sizeof(gso)) < 0) 718 return -EINVAL; 719 720 if (skb_is_gso(skb)) { 721 struct skb_shared_info *sinfo = skb_shinfo(skb); 722 723 /* This is a hint as to how much should be linear. */ 724 gso.hdr_len = skb_headlen(skb); 725 gso.gso_size = sinfo->gso_size; 726 if (sinfo->gso_type & SKB_GSO_TCPV4) 727 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 728 else if (sinfo->gso_type & SKB_GSO_TCPV6) 729 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 730 else if (sinfo->gso_type & SKB_GSO_UDP) 731 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP; 732 else 733 BUG(); 734 if (sinfo->gso_type & SKB_GSO_TCP_ECN) 735 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 736 } else 737 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE; 738 739 if (skb->ip_summed == CHECKSUM_PARTIAL) { 740 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 741 gso.csum_start = skb->csum_start - skb_headroom(skb); 742 gso.csum_offset = skb->csum_offset; 743 } /* else everything is zero */ 744 745 if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total, 746 sizeof(gso)))) 747 return -EFAULT; 748 total += sizeof(gso); 749 } 750 751 len = min_t(int, skb->len, len); 752 753 skb_copy_datagram_const_iovec(skb, 0, iv, total, len); 754 total += skb->len; 755 756 tun->dev->stats.tx_packets++; 757 tun->dev->stats.tx_bytes += len; 758 759 return total; 760 } 761 762 static ssize_t tun_do_read(struct tun_struct *tun, 763 struct kiocb *iocb, const struct iovec *iv, 764 ssize_t len, int noblock) 765 { 766 DECLARE_WAITQUEUE(wait, current); 767 struct sk_buff *skb; 768 ssize_t ret = 0; 769 770 DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name); 771 772 add_wait_queue(&tun->socket.wait, &wait); 773 while (len) { 774 current->state = TASK_INTERRUPTIBLE; 775 776 /* Read frames from the queue */ 777 if (!(skb=skb_dequeue(&tun->socket.sk->sk_receive_queue))) { 778 if (noblock) { 779 ret = -EAGAIN; 780 break; 781 } 782 if (signal_pending(current)) { 783 ret = -ERESTARTSYS; 784 break; 785 } 786 if (tun->dev->reg_state != NETREG_REGISTERED) { 787 ret = -EIO; 788 break; 789 } 790 791 /* Nothing to read, let's sleep */ 792 schedule(); 793 continue; 794 } 795 netif_wake_queue(tun->dev); 796 797 ret = tun_put_user(tun, skb, iv, len); 798 kfree_skb(skb); 799 break; 800 } 801 802 current->state = TASK_RUNNING; 803 remove_wait_queue(&tun->socket.wait, &wait); 804 805 return ret; 806 } 807 808 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv, 809 unsigned long count, loff_t pos) 810 { 811 struct file *file = iocb->ki_filp; 812 struct tun_file *tfile = file->private_data; 813 struct tun_struct *tun = __tun_get(tfile); 814 ssize_t len, ret; 815 816 if (!tun) 817 return -EBADFD; 818 len = iov_length(iv, count); 819 if (len < 0) { 820 ret = -EINVAL; 821 goto out; 822 } 823 824 ret = tun_do_read(tun, iocb, iv, len, file->f_flags & O_NONBLOCK); 825 ret = min_t(ssize_t, ret, len); 826 out: 827 tun_put(tun); 828 return ret; 829 } 830 831 static void tun_setup(struct net_device *dev) 832 { 833 struct tun_struct *tun = netdev_priv(dev); 834 835 tun->owner = -1; 836 tun->group = -1; 837 838 dev->ethtool_ops = &tun_ethtool_ops; 839 dev->destructor = tun_free_netdev; 840 } 841 842 /* Trivial set of netlink ops to allow deleting tun or tap 843 * device with netlink. 844 */ 845 static int tun_validate(struct nlattr *tb[], struct nlattr *data[]) 846 { 847 return -EINVAL; 848 } 849 850 static struct rtnl_link_ops tun_link_ops __read_mostly = { 851 .kind = DRV_NAME, 852 .priv_size = sizeof(struct tun_struct), 853 .setup = tun_setup, 854 .validate = tun_validate, 855 }; 856 857 static void tun_sock_write_space(struct sock *sk) 858 { 859 struct tun_struct *tun; 860 861 if (!sock_writeable(sk)) 862 return; 863 864 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags)) 865 return; 866 867 if (sk->sk_sleep && waitqueue_active(sk->sk_sleep)) 868 wake_up_interruptible_sync_poll(sk->sk_sleep, POLLOUT | 869 POLLWRNORM | POLLWRBAND); 870 871 tun = tun_sk(sk)->tun; 872 kill_fasync(&tun->fasync, SIGIO, POLL_OUT); 873 } 874 875 static void tun_sock_destruct(struct sock *sk) 876 { 877 free_netdev(tun_sk(sk)->tun->dev); 878 } 879 880 static int tun_sendmsg(struct kiocb *iocb, struct socket *sock, 881 struct msghdr *m, size_t total_len) 882 { 883 struct tun_struct *tun = container_of(sock, struct tun_struct, socket); 884 return tun_get_user(tun, m->msg_iov, total_len, 885 m->msg_flags & MSG_DONTWAIT); 886 } 887 888 static int tun_recvmsg(struct kiocb *iocb, struct socket *sock, 889 struct msghdr *m, size_t total_len, 890 int flags) 891 { 892 struct tun_struct *tun = container_of(sock, struct tun_struct, socket); 893 int ret; 894 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC)) 895 return -EINVAL; 896 ret = tun_do_read(tun, iocb, m->msg_iov, total_len, 897 flags & MSG_DONTWAIT); 898 if (ret > total_len) { 899 m->msg_flags |= MSG_TRUNC; 900 ret = flags & MSG_TRUNC ? ret : total_len; 901 } 902 return ret; 903 } 904 905 /* Ops structure to mimic raw sockets with tun */ 906 static const struct proto_ops tun_socket_ops = { 907 .sendmsg = tun_sendmsg, 908 .recvmsg = tun_recvmsg, 909 }; 910 911 static struct proto tun_proto = { 912 .name = "tun", 913 .owner = THIS_MODULE, 914 .obj_size = sizeof(struct tun_sock), 915 }; 916 917 static int tun_flags(struct tun_struct *tun) 918 { 919 int flags = 0; 920 921 if (tun->flags & TUN_TUN_DEV) 922 flags |= IFF_TUN; 923 else 924 flags |= IFF_TAP; 925 926 if (tun->flags & TUN_NO_PI) 927 flags |= IFF_NO_PI; 928 929 if (tun->flags & TUN_ONE_QUEUE) 930 flags |= IFF_ONE_QUEUE; 931 932 if (tun->flags & TUN_VNET_HDR) 933 flags |= IFF_VNET_HDR; 934 935 return flags; 936 } 937 938 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr, 939 char *buf) 940 { 941 struct tun_struct *tun = netdev_priv(to_net_dev(dev)); 942 return sprintf(buf, "0x%x\n", tun_flags(tun)); 943 } 944 945 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr, 946 char *buf) 947 { 948 struct tun_struct *tun = netdev_priv(to_net_dev(dev)); 949 return sprintf(buf, "%d\n", tun->owner); 950 } 951 952 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr, 953 char *buf) 954 { 955 struct tun_struct *tun = netdev_priv(to_net_dev(dev)); 956 return sprintf(buf, "%d\n", tun->group); 957 } 958 959 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL); 960 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL); 961 static DEVICE_ATTR(group, 0444, tun_show_group, NULL); 962 963 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) 964 { 965 struct sock *sk; 966 struct tun_struct *tun; 967 struct net_device *dev; 968 int err; 969 970 dev = __dev_get_by_name(net, ifr->ifr_name); 971 if (dev) { 972 const struct cred *cred = current_cred(); 973 974 if (ifr->ifr_flags & IFF_TUN_EXCL) 975 return -EBUSY; 976 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops) 977 tun = netdev_priv(dev); 978 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops) 979 tun = netdev_priv(dev); 980 else 981 return -EINVAL; 982 983 if (((tun->owner != -1 && cred->euid != tun->owner) || 984 (tun->group != -1 && !in_egroup_p(tun->group))) && 985 !capable(CAP_NET_ADMIN)) 986 return -EPERM; 987 err = security_tun_dev_attach(tun->socket.sk); 988 if (err < 0) 989 return err; 990 991 err = tun_attach(tun, file); 992 if (err < 0) 993 return err; 994 } 995 else { 996 char *name; 997 unsigned long flags = 0; 998 999 if (!capable(CAP_NET_ADMIN)) 1000 return -EPERM; 1001 err = security_tun_dev_create(); 1002 if (err < 0) 1003 return err; 1004 1005 /* Set dev type */ 1006 if (ifr->ifr_flags & IFF_TUN) { 1007 /* TUN device */ 1008 flags |= TUN_TUN_DEV; 1009 name = "tun%d"; 1010 } else if (ifr->ifr_flags & IFF_TAP) { 1011 /* TAP device */ 1012 flags |= TUN_TAP_DEV; 1013 name = "tap%d"; 1014 } else 1015 return -EINVAL; 1016 1017 if (*ifr->ifr_name) 1018 name = ifr->ifr_name; 1019 1020 dev = alloc_netdev(sizeof(struct tun_struct), name, 1021 tun_setup); 1022 if (!dev) 1023 return -ENOMEM; 1024 1025 dev_net_set(dev, net); 1026 dev->rtnl_link_ops = &tun_link_ops; 1027 1028 tun = netdev_priv(dev); 1029 tun->dev = dev; 1030 tun->flags = flags; 1031 tun->txflt.count = 0; 1032 1033 err = -ENOMEM; 1034 sk = sk_alloc(net, AF_UNSPEC, GFP_KERNEL, &tun_proto); 1035 if (!sk) 1036 goto err_free_dev; 1037 1038 init_waitqueue_head(&tun->socket.wait); 1039 tun->socket.ops = &tun_socket_ops; 1040 sock_init_data(&tun->socket, sk); 1041 sk->sk_write_space = tun_sock_write_space; 1042 sk->sk_sndbuf = INT_MAX; 1043 1044 tun_sk(sk)->tun = tun; 1045 1046 security_tun_dev_post_create(sk); 1047 1048 tun_net_init(dev); 1049 1050 if (strchr(dev->name, '%')) { 1051 err = dev_alloc_name(dev, dev->name); 1052 if (err < 0) 1053 goto err_free_sk; 1054 } 1055 1056 err = register_netdevice(tun->dev); 1057 if (err < 0) 1058 goto err_free_sk; 1059 1060 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) || 1061 device_create_file(&tun->dev->dev, &dev_attr_owner) || 1062 device_create_file(&tun->dev->dev, &dev_attr_group)) 1063 printk(KERN_ERR "Failed to create tun sysfs files\n"); 1064 1065 sk->sk_destruct = tun_sock_destruct; 1066 1067 err = tun_attach(tun, file); 1068 if (err < 0) 1069 goto failed; 1070 } 1071 1072 DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name); 1073 1074 if (ifr->ifr_flags & IFF_NO_PI) 1075 tun->flags |= TUN_NO_PI; 1076 else 1077 tun->flags &= ~TUN_NO_PI; 1078 1079 if (ifr->ifr_flags & IFF_ONE_QUEUE) 1080 tun->flags |= TUN_ONE_QUEUE; 1081 else 1082 tun->flags &= ~TUN_ONE_QUEUE; 1083 1084 if (ifr->ifr_flags & IFF_VNET_HDR) 1085 tun->flags |= TUN_VNET_HDR; 1086 else 1087 tun->flags &= ~TUN_VNET_HDR; 1088 1089 /* Make sure persistent devices do not get stuck in 1090 * xoff state. 1091 */ 1092 if (netif_running(tun->dev)) 1093 netif_wake_queue(tun->dev); 1094 1095 strcpy(ifr->ifr_name, tun->dev->name); 1096 return 0; 1097 1098 err_free_sk: 1099 sock_put(sk); 1100 err_free_dev: 1101 free_netdev(dev); 1102 failed: 1103 return err; 1104 } 1105 1106 static int tun_get_iff(struct net *net, struct tun_struct *tun, 1107 struct ifreq *ifr) 1108 { 1109 DBG(KERN_INFO "%s: tun_get_iff\n", tun->dev->name); 1110 1111 strcpy(ifr->ifr_name, tun->dev->name); 1112 1113 ifr->ifr_flags = tun_flags(tun); 1114 1115 return 0; 1116 } 1117 1118 /* This is like a cut-down ethtool ops, except done via tun fd so no 1119 * privs required. */ 1120 static int set_offload(struct net_device *dev, unsigned long arg) 1121 { 1122 unsigned int old_features, features; 1123 1124 old_features = dev->features; 1125 /* Unset features, set them as we chew on the arg. */ 1126 features = (old_features & ~(NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST 1127 |NETIF_F_TSO_ECN|NETIF_F_TSO|NETIF_F_TSO6 1128 |NETIF_F_UFO)); 1129 1130 if (arg & TUN_F_CSUM) { 1131 features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; 1132 arg &= ~TUN_F_CSUM; 1133 1134 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) { 1135 if (arg & TUN_F_TSO_ECN) { 1136 features |= NETIF_F_TSO_ECN; 1137 arg &= ~TUN_F_TSO_ECN; 1138 } 1139 if (arg & TUN_F_TSO4) 1140 features |= NETIF_F_TSO; 1141 if (arg & TUN_F_TSO6) 1142 features |= NETIF_F_TSO6; 1143 arg &= ~(TUN_F_TSO4|TUN_F_TSO6); 1144 } 1145 1146 if (arg & TUN_F_UFO) { 1147 features |= NETIF_F_UFO; 1148 arg &= ~TUN_F_UFO; 1149 } 1150 } 1151 1152 /* This gives the user a way to test for new features in future by 1153 * trying to set them. */ 1154 if (arg) 1155 return -EINVAL; 1156 1157 dev->features = features; 1158 if (old_features != dev->features) 1159 netdev_features_change(dev); 1160 1161 return 0; 1162 } 1163 1164 static long __tun_chr_ioctl(struct file *file, unsigned int cmd, 1165 unsigned long arg, int ifreq_len) 1166 { 1167 struct tun_file *tfile = file->private_data; 1168 struct tun_struct *tun; 1169 void __user* argp = (void __user*)arg; 1170 struct sock_fprog fprog; 1171 struct ifreq ifr; 1172 int sndbuf; 1173 int ret; 1174 1175 if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89) 1176 if (copy_from_user(&ifr, argp, ifreq_len)) 1177 return -EFAULT; 1178 1179 if (cmd == TUNGETFEATURES) { 1180 /* Currently this just means: "what IFF flags are valid?". 1181 * This is needed because we never checked for invalid flags on 1182 * TUNSETIFF. */ 1183 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE | 1184 IFF_VNET_HDR, 1185 (unsigned int __user*)argp); 1186 } 1187 1188 rtnl_lock(); 1189 1190 tun = __tun_get(tfile); 1191 if (cmd == TUNSETIFF && !tun) { 1192 ifr.ifr_name[IFNAMSIZ-1] = '\0'; 1193 1194 ret = tun_set_iff(tfile->net, file, &ifr); 1195 1196 if (ret) 1197 goto unlock; 1198 1199 if (copy_to_user(argp, &ifr, ifreq_len)) 1200 ret = -EFAULT; 1201 goto unlock; 1202 } 1203 1204 ret = -EBADFD; 1205 if (!tun) 1206 goto unlock; 1207 1208 DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd); 1209 1210 ret = 0; 1211 switch (cmd) { 1212 case TUNGETIFF: 1213 ret = tun_get_iff(current->nsproxy->net_ns, tun, &ifr); 1214 if (ret) 1215 break; 1216 1217 if (copy_to_user(argp, &ifr, ifreq_len)) 1218 ret = -EFAULT; 1219 break; 1220 1221 case TUNSETNOCSUM: 1222 /* Disable/Enable checksum */ 1223 if (arg) 1224 tun->flags |= TUN_NOCHECKSUM; 1225 else 1226 tun->flags &= ~TUN_NOCHECKSUM; 1227 1228 DBG(KERN_INFO "%s: checksum %s\n", 1229 tun->dev->name, arg ? "disabled" : "enabled"); 1230 break; 1231 1232 case TUNSETPERSIST: 1233 /* Disable/Enable persist mode */ 1234 if (arg) 1235 tun->flags |= TUN_PERSIST; 1236 else 1237 tun->flags &= ~TUN_PERSIST; 1238 1239 DBG(KERN_INFO "%s: persist %s\n", 1240 tun->dev->name, arg ? "enabled" : "disabled"); 1241 break; 1242 1243 case TUNSETOWNER: 1244 /* Set owner of the device */ 1245 tun->owner = (uid_t) arg; 1246 1247 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner); 1248 break; 1249 1250 case TUNSETGROUP: 1251 /* Set group of the device */ 1252 tun->group= (gid_t) arg; 1253 1254 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group); 1255 break; 1256 1257 case TUNSETLINK: 1258 /* Only allow setting the type when the interface is down */ 1259 if (tun->dev->flags & IFF_UP) { 1260 DBG(KERN_INFO "%s: Linktype set failed because interface is up\n", 1261 tun->dev->name); 1262 ret = -EBUSY; 1263 } else { 1264 tun->dev->type = (int) arg; 1265 DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type); 1266 ret = 0; 1267 } 1268 break; 1269 1270 #ifdef TUN_DEBUG 1271 case TUNSETDEBUG: 1272 tun->debug = arg; 1273 break; 1274 #endif 1275 case TUNSETOFFLOAD: 1276 ret = set_offload(tun->dev, arg); 1277 break; 1278 1279 case TUNSETTXFILTER: 1280 /* Can be set only for TAPs */ 1281 ret = -EINVAL; 1282 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV) 1283 break; 1284 ret = update_filter(&tun->txflt, (void __user *)arg); 1285 break; 1286 1287 case SIOCGIFHWADDR: 1288 /* Get hw addres */ 1289 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN); 1290 ifr.ifr_hwaddr.sa_family = tun->dev->type; 1291 if (copy_to_user(argp, &ifr, ifreq_len)) 1292 ret = -EFAULT; 1293 break; 1294 1295 case SIOCSIFHWADDR: 1296 /* Set hw address */ 1297 DBG(KERN_DEBUG "%s: set hw address: %pM\n", 1298 tun->dev->name, ifr.ifr_hwaddr.sa_data); 1299 1300 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr); 1301 break; 1302 1303 case TUNGETSNDBUF: 1304 sndbuf = tun->socket.sk->sk_sndbuf; 1305 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf))) 1306 ret = -EFAULT; 1307 break; 1308 1309 case TUNSETSNDBUF: 1310 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) { 1311 ret = -EFAULT; 1312 break; 1313 } 1314 1315 tun->socket.sk->sk_sndbuf = sndbuf; 1316 break; 1317 1318 case TUNATTACHFILTER: 1319 /* Can be set only for TAPs */ 1320 ret = -EINVAL; 1321 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV) 1322 break; 1323 ret = -EFAULT; 1324 if (copy_from_user(&fprog, argp, sizeof(fprog))) 1325 break; 1326 1327 ret = sk_attach_filter(&fprog, tun->socket.sk); 1328 break; 1329 1330 case TUNDETACHFILTER: 1331 /* Can be set only for TAPs */ 1332 ret = -EINVAL; 1333 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV) 1334 break; 1335 ret = sk_detach_filter(tun->socket.sk); 1336 break; 1337 1338 default: 1339 ret = -EINVAL; 1340 break; 1341 }; 1342 1343 unlock: 1344 rtnl_unlock(); 1345 if (tun) 1346 tun_put(tun); 1347 return ret; 1348 } 1349 1350 static long tun_chr_ioctl(struct file *file, 1351 unsigned int cmd, unsigned long arg) 1352 { 1353 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq)); 1354 } 1355 1356 #ifdef CONFIG_COMPAT 1357 static long tun_chr_compat_ioctl(struct file *file, 1358 unsigned int cmd, unsigned long arg) 1359 { 1360 switch (cmd) { 1361 case TUNSETIFF: 1362 case TUNGETIFF: 1363 case TUNSETTXFILTER: 1364 case TUNGETSNDBUF: 1365 case TUNSETSNDBUF: 1366 case SIOCGIFHWADDR: 1367 case SIOCSIFHWADDR: 1368 arg = (unsigned long)compat_ptr(arg); 1369 break; 1370 default: 1371 arg = (compat_ulong_t)arg; 1372 break; 1373 } 1374 1375 /* 1376 * compat_ifreq is shorter than ifreq, so we must not access beyond 1377 * the end of that structure. All fields that are used in this 1378 * driver are compatible though, we don't need to convert the 1379 * contents. 1380 */ 1381 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq)); 1382 } 1383 #endif /* CONFIG_COMPAT */ 1384 1385 static int tun_chr_fasync(int fd, struct file *file, int on) 1386 { 1387 struct tun_struct *tun = tun_get(file); 1388 int ret; 1389 1390 if (!tun) 1391 return -EBADFD; 1392 1393 DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on); 1394 1395 if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0) 1396 goto out; 1397 1398 if (on) { 1399 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0); 1400 if (ret) 1401 goto out; 1402 tun->flags |= TUN_FASYNC; 1403 } else 1404 tun->flags &= ~TUN_FASYNC; 1405 ret = 0; 1406 out: 1407 tun_put(tun); 1408 return ret; 1409 } 1410 1411 static int tun_chr_open(struct inode *inode, struct file * file) 1412 { 1413 struct tun_file *tfile; 1414 1415 DBG1(KERN_INFO "tunX: tun_chr_open\n"); 1416 1417 tfile = kmalloc(sizeof(*tfile), GFP_KERNEL); 1418 if (!tfile) 1419 return -ENOMEM; 1420 atomic_set(&tfile->count, 0); 1421 tfile->tun = NULL; 1422 tfile->net = get_net(current->nsproxy->net_ns); 1423 file->private_data = tfile; 1424 return 0; 1425 } 1426 1427 static int tun_chr_close(struct inode *inode, struct file *file) 1428 { 1429 struct tun_file *tfile = file->private_data; 1430 struct tun_struct *tun; 1431 1432 tun = __tun_get(tfile); 1433 if (tun) { 1434 struct net_device *dev = tun->dev; 1435 1436 DBG(KERN_INFO "%s: tun_chr_close\n", dev->name); 1437 1438 __tun_detach(tun); 1439 1440 /* If desirable, unregister the netdevice. */ 1441 if (!(tun->flags & TUN_PERSIST)) { 1442 rtnl_lock(); 1443 if (dev->reg_state == NETREG_REGISTERED) 1444 unregister_netdevice(dev); 1445 rtnl_unlock(); 1446 } 1447 } 1448 1449 tun = tfile->tun; 1450 if (tun) 1451 sock_put(tun->socket.sk); 1452 1453 put_net(tfile->net); 1454 kfree(tfile); 1455 1456 return 0; 1457 } 1458 1459 static const struct file_operations tun_fops = { 1460 .owner = THIS_MODULE, 1461 .llseek = no_llseek, 1462 .read = do_sync_read, 1463 .aio_read = tun_chr_aio_read, 1464 .write = do_sync_write, 1465 .aio_write = tun_chr_aio_write, 1466 .poll = tun_chr_poll, 1467 .unlocked_ioctl = tun_chr_ioctl, 1468 #ifdef CONFIG_COMPAT 1469 .compat_ioctl = tun_chr_compat_ioctl, 1470 #endif 1471 .open = tun_chr_open, 1472 .release = tun_chr_close, 1473 .fasync = tun_chr_fasync 1474 }; 1475 1476 static struct miscdevice tun_miscdev = { 1477 .minor = TUN_MINOR, 1478 .name = "tun", 1479 .nodename = "net/tun", 1480 .fops = &tun_fops, 1481 }; 1482 1483 /* ethtool interface */ 1484 1485 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd) 1486 { 1487 cmd->supported = 0; 1488 cmd->advertising = 0; 1489 cmd->speed = SPEED_10; 1490 cmd->duplex = DUPLEX_FULL; 1491 cmd->port = PORT_TP; 1492 cmd->phy_address = 0; 1493 cmd->transceiver = XCVR_INTERNAL; 1494 cmd->autoneg = AUTONEG_DISABLE; 1495 cmd->maxtxpkt = 0; 1496 cmd->maxrxpkt = 0; 1497 return 0; 1498 } 1499 1500 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info) 1501 { 1502 struct tun_struct *tun = netdev_priv(dev); 1503 1504 strcpy(info->driver, DRV_NAME); 1505 strcpy(info->version, DRV_VERSION); 1506 strcpy(info->fw_version, "N/A"); 1507 1508 switch (tun->flags & TUN_TYPE_MASK) { 1509 case TUN_TUN_DEV: 1510 strcpy(info->bus_info, "tun"); 1511 break; 1512 case TUN_TAP_DEV: 1513 strcpy(info->bus_info, "tap"); 1514 break; 1515 } 1516 } 1517 1518 static u32 tun_get_msglevel(struct net_device *dev) 1519 { 1520 #ifdef TUN_DEBUG 1521 struct tun_struct *tun = netdev_priv(dev); 1522 return tun->debug; 1523 #else 1524 return -EOPNOTSUPP; 1525 #endif 1526 } 1527 1528 static void tun_set_msglevel(struct net_device *dev, u32 value) 1529 { 1530 #ifdef TUN_DEBUG 1531 struct tun_struct *tun = netdev_priv(dev); 1532 tun->debug = value; 1533 #endif 1534 } 1535 1536 static u32 tun_get_link(struct net_device *dev) 1537 { 1538 struct tun_struct *tun = netdev_priv(dev); 1539 return !!tun->tfile; 1540 } 1541 1542 static u32 tun_get_rx_csum(struct net_device *dev) 1543 { 1544 struct tun_struct *tun = netdev_priv(dev); 1545 return (tun->flags & TUN_NOCHECKSUM) == 0; 1546 } 1547 1548 static int tun_set_rx_csum(struct net_device *dev, u32 data) 1549 { 1550 struct tun_struct *tun = netdev_priv(dev); 1551 if (data) 1552 tun->flags &= ~TUN_NOCHECKSUM; 1553 else 1554 tun->flags |= TUN_NOCHECKSUM; 1555 return 0; 1556 } 1557 1558 static const struct ethtool_ops tun_ethtool_ops = { 1559 .get_settings = tun_get_settings, 1560 .get_drvinfo = tun_get_drvinfo, 1561 .get_msglevel = tun_get_msglevel, 1562 .set_msglevel = tun_set_msglevel, 1563 .get_link = tun_get_link, 1564 .get_rx_csum = tun_get_rx_csum, 1565 .set_rx_csum = tun_set_rx_csum 1566 }; 1567 1568 1569 static int __init tun_init(void) 1570 { 1571 int ret = 0; 1572 1573 printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION); 1574 printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT); 1575 1576 ret = rtnl_link_register(&tun_link_ops); 1577 if (ret) { 1578 printk(KERN_ERR "tun: Can't register link_ops\n"); 1579 goto err_linkops; 1580 } 1581 1582 ret = misc_register(&tun_miscdev); 1583 if (ret) { 1584 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR); 1585 goto err_misc; 1586 } 1587 return 0; 1588 err_misc: 1589 rtnl_link_unregister(&tun_link_ops); 1590 err_linkops: 1591 return ret; 1592 } 1593 1594 static void tun_cleanup(void) 1595 { 1596 misc_deregister(&tun_miscdev); 1597 rtnl_link_unregister(&tun_link_ops); 1598 } 1599 1600 /* Get an underlying socket object from tun file. Returns error unless file is 1601 * attached to a device. The returned object works like a packet socket, it 1602 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for 1603 * holding a reference to the file for as long as the socket is in use. */ 1604 struct socket *tun_get_socket(struct file *file) 1605 { 1606 struct tun_struct *tun; 1607 if (file->f_op != &tun_fops) 1608 return ERR_PTR(-EINVAL); 1609 tun = tun_get(file); 1610 if (!tun) 1611 return ERR_PTR(-EBADFD); 1612 tun_put(tun); 1613 return &tun->socket; 1614 } 1615 EXPORT_SYMBOL_GPL(tun_get_socket); 1616 1617 module_init(tun_init); 1618 module_exit(tun_cleanup); 1619 MODULE_DESCRIPTION(DRV_DESCRIPTION); 1620 MODULE_AUTHOR(DRV_COPYRIGHT); 1621 MODULE_LICENSE("GPL"); 1622 MODULE_ALIAS_MISCDEV(TUN_MINOR); 1623