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