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 struct socket_wq wq; 113 114 int vnet_hdr_sz; 115 116 #ifdef TUN_DEBUG 117 int debug; 118 #endif 119 }; 120 121 struct tun_sock { 122 struct sock sk; 123 struct tun_struct *tun; 124 }; 125 126 static inline struct tun_sock *tun_sk(struct sock *sk) 127 { 128 return container_of(sk, struct tun_sock, sk); 129 } 130 131 static int tun_attach(struct tun_struct *tun, struct file *file) 132 { 133 struct tun_file *tfile = file->private_data; 134 int err; 135 136 ASSERT_RTNL(); 137 138 netif_tx_lock_bh(tun->dev); 139 140 err = -EINVAL; 141 if (tfile->tun) 142 goto out; 143 144 err = -EBUSY; 145 if (tun->tfile) 146 goto out; 147 148 err = 0; 149 tfile->tun = tun; 150 tun->tfile = tfile; 151 tun->socket.file = file; 152 dev_hold(tun->dev); 153 sock_hold(tun->socket.sk); 154 atomic_inc(&tfile->count); 155 156 out: 157 netif_tx_unlock_bh(tun->dev); 158 return err; 159 } 160 161 static void __tun_detach(struct tun_struct *tun) 162 { 163 /* Detach from net device */ 164 netif_tx_lock_bh(tun->dev); 165 tun->tfile = NULL; 166 tun->socket.file = NULL; 167 netif_tx_unlock_bh(tun->dev); 168 169 /* Drop read queue */ 170 skb_queue_purge(&tun->socket.sk->sk_receive_queue); 171 172 /* Drop the extra count on the net device */ 173 dev_put(tun->dev); 174 } 175 176 static void tun_detach(struct tun_struct *tun) 177 { 178 rtnl_lock(); 179 __tun_detach(tun); 180 rtnl_unlock(); 181 } 182 183 static struct tun_struct *__tun_get(struct tun_file *tfile) 184 { 185 struct tun_struct *tun = NULL; 186 187 if (atomic_inc_not_zero(&tfile->count)) 188 tun = tfile->tun; 189 190 return tun; 191 } 192 193 static struct tun_struct *tun_get(struct file *file) 194 { 195 return __tun_get(file->private_data); 196 } 197 198 static void tun_put(struct tun_struct *tun) 199 { 200 struct tun_file *tfile = tun->tfile; 201 202 if (atomic_dec_and_test(&tfile->count)) 203 tun_detach(tfile->tun); 204 } 205 206 /* TAP filterting */ 207 static void addr_hash_set(u32 *mask, const u8 *addr) 208 { 209 int n = ether_crc(ETH_ALEN, addr) >> 26; 210 mask[n >> 5] |= (1 << (n & 31)); 211 } 212 213 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr) 214 { 215 int n = ether_crc(ETH_ALEN, addr) >> 26; 216 return mask[n >> 5] & (1 << (n & 31)); 217 } 218 219 static int update_filter(struct tap_filter *filter, void __user *arg) 220 { 221 struct { u8 u[ETH_ALEN]; } *addr; 222 struct tun_filter uf; 223 int err, alen, n, nexact; 224 225 if (copy_from_user(&uf, arg, sizeof(uf))) 226 return -EFAULT; 227 228 if (!uf.count) { 229 /* Disabled */ 230 filter->count = 0; 231 return 0; 232 } 233 234 alen = ETH_ALEN * uf.count; 235 addr = kmalloc(alen, GFP_KERNEL); 236 if (!addr) 237 return -ENOMEM; 238 239 if (copy_from_user(addr, arg + sizeof(uf), alen)) { 240 err = -EFAULT; 241 goto done; 242 } 243 244 /* The filter is updated without holding any locks. Which is 245 * perfectly safe. We disable it first and in the worst 246 * case we'll accept a few undesired packets. */ 247 filter->count = 0; 248 wmb(); 249 250 /* Use first set of addresses as an exact filter */ 251 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++) 252 memcpy(filter->addr[n], addr[n].u, ETH_ALEN); 253 254 nexact = n; 255 256 /* Remaining multicast addresses are hashed, 257 * unicast will leave the filter disabled. */ 258 memset(filter->mask, 0, sizeof(filter->mask)); 259 for (; n < uf.count; n++) { 260 if (!is_multicast_ether_addr(addr[n].u)) { 261 err = 0; /* no filter */ 262 goto done; 263 } 264 addr_hash_set(filter->mask, addr[n].u); 265 } 266 267 /* For ALLMULTI just set the mask to all ones. 268 * This overrides the mask populated above. */ 269 if ((uf.flags & TUN_FLT_ALLMULTI)) 270 memset(filter->mask, ~0, sizeof(filter->mask)); 271 272 /* Now enable the filter */ 273 wmb(); 274 filter->count = nexact; 275 276 /* Return the number of exact filters */ 277 err = nexact; 278 279 done: 280 kfree(addr); 281 return err; 282 } 283 284 /* Returns: 0 - drop, !=0 - accept */ 285 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb) 286 { 287 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect 288 * at this point. */ 289 struct ethhdr *eh = (struct ethhdr *) skb->data; 290 int i; 291 292 /* Exact match */ 293 for (i = 0; i < filter->count; i++) 294 if (!compare_ether_addr(eh->h_dest, filter->addr[i])) 295 return 1; 296 297 /* Inexact match (multicast only) */ 298 if (is_multicast_ether_addr(eh->h_dest)) 299 return addr_hash_test(filter->mask, eh->h_dest); 300 301 return 0; 302 } 303 304 /* 305 * Checks whether the packet is accepted or not. 306 * Returns: 0 - drop, !=0 - accept 307 */ 308 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb) 309 { 310 if (!filter->count) 311 return 1; 312 313 return run_filter(filter, skb); 314 } 315 316 /* Network device part of the driver */ 317 318 static const struct ethtool_ops tun_ethtool_ops; 319 320 /* Net device detach from fd. */ 321 static void tun_net_uninit(struct net_device *dev) 322 { 323 struct tun_struct *tun = netdev_priv(dev); 324 struct tun_file *tfile = tun->tfile; 325 326 /* Inform the methods they need to stop using the dev. 327 */ 328 if (tfile) { 329 wake_up_all(&tun->wq.wait); 330 if (atomic_dec_and_test(&tfile->count)) 331 __tun_detach(tun); 332 } 333 } 334 335 static void tun_free_netdev(struct net_device *dev) 336 { 337 struct tun_struct *tun = netdev_priv(dev); 338 339 sock_put(tun->socket.sk); 340 } 341 342 /* Net device open. */ 343 static int tun_net_open(struct net_device *dev) 344 { 345 netif_start_queue(dev); 346 return 0; 347 } 348 349 /* Net device close. */ 350 static int tun_net_close(struct net_device *dev) 351 { 352 netif_stop_queue(dev); 353 return 0; 354 } 355 356 /* Net device start xmit */ 357 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev) 358 { 359 struct tun_struct *tun = netdev_priv(dev); 360 361 DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len); 362 363 /* Drop packet if interface is not attached */ 364 if (!tun->tfile) 365 goto drop; 366 367 /* Drop if the filter does not like it. 368 * This is a noop if the filter is disabled. 369 * Filter can be enabled only for the TAP devices. */ 370 if (!check_filter(&tun->txflt, skb)) 371 goto drop; 372 373 if (tun->socket.sk->sk_filter && 374 sk_filter(tun->socket.sk, skb)) 375 goto drop; 376 377 if (skb_queue_len(&tun->socket.sk->sk_receive_queue) >= dev->tx_queue_len) { 378 if (!(tun->flags & TUN_ONE_QUEUE)) { 379 /* Normal queueing mode. */ 380 /* Packet scheduler handles dropping of further packets. */ 381 netif_stop_queue(dev); 382 383 /* We won't see all dropped packets individually, so overrun 384 * error is more appropriate. */ 385 dev->stats.tx_fifo_errors++; 386 } else { 387 /* Single queue mode. 388 * Driver handles dropping of all packets itself. */ 389 goto drop; 390 } 391 } 392 393 /* Orphan the skb - required as we might hang on to it 394 * for indefinite time. */ 395 skb_orphan(skb); 396 397 /* Enqueue packet */ 398 skb_queue_tail(&tun->socket.sk->sk_receive_queue, skb); 399 400 /* Notify and wake up reader process */ 401 if (tun->flags & TUN_FASYNC) 402 kill_fasync(&tun->fasync, SIGIO, POLL_IN); 403 wake_up_interruptible_poll(&tun->wq.wait, POLLIN | 404 POLLRDNORM | POLLRDBAND); 405 return NETDEV_TX_OK; 406 407 drop: 408 dev->stats.tx_dropped++; 409 kfree_skb(skb); 410 return NETDEV_TX_OK; 411 } 412 413 static void tun_net_mclist(struct net_device *dev) 414 { 415 /* 416 * This callback is supposed to deal with mc filter in 417 * _rx_ path and has nothing to do with the _tx_ path. 418 * In rx path we always accept everything userspace gives us. 419 */ 420 } 421 422 #define MIN_MTU 68 423 #define MAX_MTU 65535 424 425 static int 426 tun_net_change_mtu(struct net_device *dev, int new_mtu) 427 { 428 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU) 429 return -EINVAL; 430 dev->mtu = new_mtu; 431 return 0; 432 } 433 434 static const struct net_device_ops tun_netdev_ops = { 435 .ndo_uninit = tun_net_uninit, 436 .ndo_open = tun_net_open, 437 .ndo_stop = tun_net_close, 438 .ndo_start_xmit = tun_net_xmit, 439 .ndo_change_mtu = tun_net_change_mtu, 440 }; 441 442 static const struct net_device_ops tap_netdev_ops = { 443 .ndo_uninit = tun_net_uninit, 444 .ndo_open = tun_net_open, 445 .ndo_stop = tun_net_close, 446 .ndo_start_xmit = tun_net_xmit, 447 .ndo_change_mtu = tun_net_change_mtu, 448 .ndo_set_multicast_list = tun_net_mclist, 449 .ndo_set_mac_address = eth_mac_addr, 450 .ndo_validate_addr = eth_validate_addr, 451 }; 452 453 /* Initialize net device. */ 454 static void tun_net_init(struct net_device *dev) 455 { 456 struct tun_struct *tun = netdev_priv(dev); 457 458 switch (tun->flags & TUN_TYPE_MASK) { 459 case TUN_TUN_DEV: 460 dev->netdev_ops = &tun_netdev_ops; 461 462 /* Point-to-Point TUN Device */ 463 dev->hard_header_len = 0; 464 dev->addr_len = 0; 465 dev->mtu = 1500; 466 467 /* Zero header length */ 468 dev->type = ARPHRD_NONE; 469 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 470 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */ 471 break; 472 473 case TUN_TAP_DEV: 474 dev->netdev_ops = &tap_netdev_ops; 475 /* Ethernet TAP Device */ 476 ether_setup(dev); 477 478 random_ether_addr(dev->dev_addr); 479 480 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */ 481 break; 482 } 483 } 484 485 /* Character device part */ 486 487 /* Poll */ 488 static unsigned int tun_chr_poll(struct file *file, poll_table * wait) 489 { 490 struct tun_file *tfile = file->private_data; 491 struct tun_struct *tun = __tun_get(tfile); 492 struct sock *sk; 493 unsigned int mask = 0; 494 495 if (!tun) 496 return POLLERR; 497 498 sk = tun->socket.sk; 499 500 DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name); 501 502 poll_wait(file, &tun->wq.wait, wait); 503 504 if (!skb_queue_empty(&sk->sk_receive_queue)) 505 mask |= POLLIN | POLLRDNORM; 506 507 if (sock_writeable(sk) || 508 (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) && 509 sock_writeable(sk))) 510 mask |= POLLOUT | POLLWRNORM; 511 512 if (tun->dev->reg_state != NETREG_REGISTERED) 513 mask = POLLERR; 514 515 tun_put(tun); 516 return mask; 517 } 518 519 /* prepad is the amount to reserve at front. len is length after that. 520 * linear is a hint as to how much to copy (usually headers). */ 521 static inline struct sk_buff *tun_alloc_skb(struct tun_struct *tun, 522 size_t prepad, size_t len, 523 size_t linear, int noblock) 524 { 525 struct sock *sk = tun->socket.sk; 526 struct sk_buff *skb; 527 int err; 528 529 sock_update_classid(sk); 530 531 /* Under a page? Don't bother with paged skb. */ 532 if (prepad + len < PAGE_SIZE || !linear) 533 linear = len; 534 535 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 536 &err); 537 if (!skb) 538 return ERR_PTR(err); 539 540 skb_reserve(skb, prepad); 541 skb_put(skb, linear); 542 skb->data_len = len - linear; 543 skb->len += len - linear; 544 545 return skb; 546 } 547 548 /* Get packet from user space buffer */ 549 static __inline__ ssize_t tun_get_user(struct tun_struct *tun, 550 const struct iovec *iv, size_t count, 551 int noblock) 552 { 553 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) }; 554 struct sk_buff *skb; 555 size_t len = count, align = 0; 556 struct virtio_net_hdr gso = { 0 }; 557 int offset = 0; 558 559 if (!(tun->flags & TUN_NO_PI)) { 560 if ((len -= sizeof(pi)) > count) 561 return -EINVAL; 562 563 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi))) 564 return -EFAULT; 565 offset += sizeof(pi); 566 } 567 568 if (tun->flags & TUN_VNET_HDR) { 569 if ((len -= tun->vnet_hdr_sz) > count) 570 return -EINVAL; 571 572 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso))) 573 return -EFAULT; 574 575 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 576 gso.csum_start + gso.csum_offset + 2 > gso.hdr_len) 577 gso.hdr_len = gso.csum_start + gso.csum_offset + 2; 578 579 if (gso.hdr_len > len) 580 return -EINVAL; 581 offset += tun->vnet_hdr_sz; 582 } 583 584 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) { 585 align = NET_IP_ALIGN; 586 if (unlikely(len < ETH_HLEN || 587 (gso.hdr_len && gso.hdr_len < ETH_HLEN))) 588 return -EINVAL; 589 } 590 591 skb = tun_alloc_skb(tun, align, len, gso.hdr_len, noblock); 592 if (IS_ERR(skb)) { 593 if (PTR_ERR(skb) != -EAGAIN) 594 tun->dev->stats.rx_dropped++; 595 return PTR_ERR(skb); 596 } 597 598 if (skb_copy_datagram_from_iovec(skb, 0, iv, offset, len)) { 599 tun->dev->stats.rx_dropped++; 600 kfree_skb(skb); 601 return -EFAULT; 602 } 603 604 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 605 if (!skb_partial_csum_set(skb, gso.csum_start, 606 gso.csum_offset)) { 607 tun->dev->stats.rx_frame_errors++; 608 kfree_skb(skb); 609 return -EINVAL; 610 } 611 } else if (tun->flags & TUN_NOCHECKSUM) 612 skb->ip_summed = CHECKSUM_UNNECESSARY; 613 614 switch (tun->flags & TUN_TYPE_MASK) { 615 case TUN_TUN_DEV: 616 if (tun->flags & TUN_NO_PI) { 617 switch (skb->data[0] & 0xf0) { 618 case 0x40: 619 pi.proto = htons(ETH_P_IP); 620 break; 621 case 0x60: 622 pi.proto = htons(ETH_P_IPV6); 623 break; 624 default: 625 tun->dev->stats.rx_dropped++; 626 kfree_skb(skb); 627 return -EINVAL; 628 } 629 } 630 631 skb_reset_mac_header(skb); 632 skb->protocol = pi.proto; 633 skb->dev = tun->dev; 634 break; 635 case TUN_TAP_DEV: 636 skb->protocol = eth_type_trans(skb, tun->dev); 637 break; 638 }; 639 640 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 641 pr_debug("GSO!\n"); 642 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 643 case VIRTIO_NET_HDR_GSO_TCPV4: 644 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; 645 break; 646 case VIRTIO_NET_HDR_GSO_TCPV6: 647 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; 648 break; 649 case VIRTIO_NET_HDR_GSO_UDP: 650 skb_shinfo(skb)->gso_type = SKB_GSO_UDP; 651 break; 652 default: 653 tun->dev->stats.rx_frame_errors++; 654 kfree_skb(skb); 655 return -EINVAL; 656 } 657 658 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN) 659 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; 660 661 skb_shinfo(skb)->gso_size = gso.gso_size; 662 if (skb_shinfo(skb)->gso_size == 0) { 663 tun->dev->stats.rx_frame_errors++; 664 kfree_skb(skb); 665 return -EINVAL; 666 } 667 668 /* Header must be checked, and gso_segs computed. */ 669 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 670 skb_shinfo(skb)->gso_segs = 0; 671 } 672 673 netif_rx_ni(skb); 674 675 tun->dev->stats.rx_packets++; 676 tun->dev->stats.rx_bytes += len; 677 678 return count; 679 } 680 681 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv, 682 unsigned long count, loff_t pos) 683 { 684 struct file *file = iocb->ki_filp; 685 struct tun_struct *tun = tun_get(file); 686 ssize_t result; 687 688 if (!tun) 689 return -EBADFD; 690 691 DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count); 692 693 result = tun_get_user(tun, iv, iov_length(iv, count), 694 file->f_flags & O_NONBLOCK); 695 696 tun_put(tun); 697 return result; 698 } 699 700 /* Put packet to the user space buffer */ 701 static __inline__ ssize_t tun_put_user(struct tun_struct *tun, 702 struct sk_buff *skb, 703 const struct iovec *iv, int len) 704 { 705 struct tun_pi pi = { 0, skb->protocol }; 706 ssize_t total = 0; 707 708 if (!(tun->flags & TUN_NO_PI)) { 709 if ((len -= sizeof(pi)) < 0) 710 return -EINVAL; 711 712 if (len < skb->len) { 713 /* Packet will be striped */ 714 pi.flags |= TUN_PKT_STRIP; 715 } 716 717 if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi))) 718 return -EFAULT; 719 total += sizeof(pi); 720 } 721 722 if (tun->flags & TUN_VNET_HDR) { 723 struct virtio_net_hdr gso = { 0 }; /* no info leak */ 724 if ((len -= tun->vnet_hdr_sz) < 0) 725 return -EINVAL; 726 727 if (skb_is_gso(skb)) { 728 struct skb_shared_info *sinfo = skb_shinfo(skb); 729 730 /* This is a hint as to how much should be linear. */ 731 gso.hdr_len = skb_headlen(skb); 732 gso.gso_size = sinfo->gso_size; 733 if (sinfo->gso_type & SKB_GSO_TCPV4) 734 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 735 else if (sinfo->gso_type & SKB_GSO_TCPV6) 736 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 737 else if (sinfo->gso_type & SKB_GSO_UDP) 738 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP; 739 else 740 BUG(); 741 if (sinfo->gso_type & SKB_GSO_TCP_ECN) 742 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 743 } else 744 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE; 745 746 if (skb->ip_summed == CHECKSUM_PARTIAL) { 747 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 748 gso.csum_start = skb->csum_start - skb_headroom(skb); 749 gso.csum_offset = skb->csum_offset; 750 } /* else everything is zero */ 751 752 if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total, 753 sizeof(gso)))) 754 return -EFAULT; 755 total += tun->vnet_hdr_sz; 756 } 757 758 len = min_t(int, skb->len, len); 759 760 skb_copy_datagram_const_iovec(skb, 0, iv, total, len); 761 total += skb->len; 762 763 tun->dev->stats.tx_packets++; 764 tun->dev->stats.tx_bytes += len; 765 766 return total; 767 } 768 769 static ssize_t tun_do_read(struct tun_struct *tun, 770 struct kiocb *iocb, const struct iovec *iv, 771 ssize_t len, int noblock) 772 { 773 DECLARE_WAITQUEUE(wait, current); 774 struct sk_buff *skb; 775 ssize_t ret = 0; 776 777 DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name); 778 779 add_wait_queue(&tun->wq.wait, &wait); 780 while (len) { 781 current->state = TASK_INTERRUPTIBLE; 782 783 /* Read frames from the queue */ 784 if (!(skb=skb_dequeue(&tun->socket.sk->sk_receive_queue))) { 785 if (noblock) { 786 ret = -EAGAIN; 787 break; 788 } 789 if (signal_pending(current)) { 790 ret = -ERESTARTSYS; 791 break; 792 } 793 if (tun->dev->reg_state != NETREG_REGISTERED) { 794 ret = -EIO; 795 break; 796 } 797 798 /* Nothing to read, let's sleep */ 799 schedule(); 800 continue; 801 } 802 netif_wake_queue(tun->dev); 803 804 ret = tun_put_user(tun, skb, iv, len); 805 kfree_skb(skb); 806 break; 807 } 808 809 current->state = TASK_RUNNING; 810 remove_wait_queue(&tun->wq.wait, &wait); 811 812 return ret; 813 } 814 815 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv, 816 unsigned long count, loff_t pos) 817 { 818 struct file *file = iocb->ki_filp; 819 struct tun_file *tfile = file->private_data; 820 struct tun_struct *tun = __tun_get(tfile); 821 ssize_t len, ret; 822 823 if (!tun) 824 return -EBADFD; 825 len = iov_length(iv, count); 826 if (len < 0) { 827 ret = -EINVAL; 828 goto out; 829 } 830 831 ret = tun_do_read(tun, iocb, iv, len, file->f_flags & O_NONBLOCK); 832 ret = min_t(ssize_t, ret, len); 833 out: 834 tun_put(tun); 835 return ret; 836 } 837 838 static void tun_setup(struct net_device *dev) 839 { 840 struct tun_struct *tun = netdev_priv(dev); 841 842 tun->owner = -1; 843 tun->group = -1; 844 845 dev->ethtool_ops = &tun_ethtool_ops; 846 dev->destructor = tun_free_netdev; 847 } 848 849 /* Trivial set of netlink ops to allow deleting tun or tap 850 * device with netlink. 851 */ 852 static int tun_validate(struct nlattr *tb[], struct nlattr *data[]) 853 { 854 return -EINVAL; 855 } 856 857 static struct rtnl_link_ops tun_link_ops __read_mostly = { 858 .kind = DRV_NAME, 859 .priv_size = sizeof(struct tun_struct), 860 .setup = tun_setup, 861 .validate = tun_validate, 862 }; 863 864 static void tun_sock_write_space(struct sock *sk) 865 { 866 struct tun_struct *tun; 867 wait_queue_head_t *wqueue; 868 869 if (!sock_writeable(sk)) 870 return; 871 872 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags)) 873 return; 874 875 wqueue = sk_sleep(sk); 876 if (wqueue && waitqueue_active(wqueue)) 877 wake_up_interruptible_sync_poll(wqueue, POLLOUT | 878 POLLWRNORM | POLLWRBAND); 879 880 tun = tun_sk(sk)->tun; 881 kill_fasync(&tun->fasync, SIGIO, POLL_OUT); 882 } 883 884 static void tun_sock_destruct(struct sock *sk) 885 { 886 free_netdev(tun_sk(sk)->tun->dev); 887 } 888 889 static int tun_sendmsg(struct kiocb *iocb, struct socket *sock, 890 struct msghdr *m, size_t total_len) 891 { 892 struct tun_struct *tun = container_of(sock, struct tun_struct, socket); 893 return tun_get_user(tun, m->msg_iov, total_len, 894 m->msg_flags & MSG_DONTWAIT); 895 } 896 897 static int tun_recvmsg(struct kiocb *iocb, struct socket *sock, 898 struct msghdr *m, size_t total_len, 899 int flags) 900 { 901 struct tun_struct *tun = container_of(sock, struct tun_struct, socket); 902 int ret; 903 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC)) 904 return -EINVAL; 905 ret = tun_do_read(tun, iocb, m->msg_iov, total_len, 906 flags & MSG_DONTWAIT); 907 if (ret > total_len) { 908 m->msg_flags |= MSG_TRUNC; 909 ret = flags & MSG_TRUNC ? ret : total_len; 910 } 911 return ret; 912 } 913 914 /* Ops structure to mimic raw sockets with tun */ 915 static const struct proto_ops tun_socket_ops = { 916 .sendmsg = tun_sendmsg, 917 .recvmsg = tun_recvmsg, 918 }; 919 920 static struct proto tun_proto = { 921 .name = "tun", 922 .owner = THIS_MODULE, 923 .obj_size = sizeof(struct tun_sock), 924 }; 925 926 static int tun_flags(struct tun_struct *tun) 927 { 928 int flags = 0; 929 930 if (tun->flags & TUN_TUN_DEV) 931 flags |= IFF_TUN; 932 else 933 flags |= IFF_TAP; 934 935 if (tun->flags & TUN_NO_PI) 936 flags |= IFF_NO_PI; 937 938 if (tun->flags & TUN_ONE_QUEUE) 939 flags |= IFF_ONE_QUEUE; 940 941 if (tun->flags & TUN_VNET_HDR) 942 flags |= IFF_VNET_HDR; 943 944 return flags; 945 } 946 947 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr, 948 char *buf) 949 { 950 struct tun_struct *tun = netdev_priv(to_net_dev(dev)); 951 return sprintf(buf, "0x%x\n", tun_flags(tun)); 952 } 953 954 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr, 955 char *buf) 956 { 957 struct tun_struct *tun = netdev_priv(to_net_dev(dev)); 958 return sprintf(buf, "%d\n", tun->owner); 959 } 960 961 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr, 962 char *buf) 963 { 964 struct tun_struct *tun = netdev_priv(to_net_dev(dev)); 965 return sprintf(buf, "%d\n", tun->group); 966 } 967 968 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL); 969 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL); 970 static DEVICE_ATTR(group, 0444, tun_show_group, NULL); 971 972 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) 973 { 974 struct sock *sk; 975 struct tun_struct *tun; 976 struct net_device *dev; 977 int err; 978 979 dev = __dev_get_by_name(net, ifr->ifr_name); 980 if (dev) { 981 const struct cred *cred = current_cred(); 982 983 if (ifr->ifr_flags & IFF_TUN_EXCL) 984 return -EBUSY; 985 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops) 986 tun = netdev_priv(dev); 987 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops) 988 tun = netdev_priv(dev); 989 else 990 return -EINVAL; 991 992 if (((tun->owner != -1 && cred->euid != tun->owner) || 993 (tun->group != -1 && !in_egroup_p(tun->group))) && 994 !capable(CAP_NET_ADMIN)) 995 return -EPERM; 996 err = security_tun_dev_attach(tun->socket.sk); 997 if (err < 0) 998 return err; 999 1000 err = tun_attach(tun, file); 1001 if (err < 0) 1002 return err; 1003 } 1004 else { 1005 char *name; 1006 unsigned long flags = 0; 1007 1008 if (!capable(CAP_NET_ADMIN)) 1009 return -EPERM; 1010 err = security_tun_dev_create(); 1011 if (err < 0) 1012 return err; 1013 1014 /* Set dev type */ 1015 if (ifr->ifr_flags & IFF_TUN) { 1016 /* TUN device */ 1017 flags |= TUN_TUN_DEV; 1018 name = "tun%d"; 1019 } else if (ifr->ifr_flags & IFF_TAP) { 1020 /* TAP device */ 1021 flags |= TUN_TAP_DEV; 1022 name = "tap%d"; 1023 } else 1024 return -EINVAL; 1025 1026 if (*ifr->ifr_name) 1027 name = ifr->ifr_name; 1028 1029 dev = alloc_netdev(sizeof(struct tun_struct), name, 1030 tun_setup); 1031 if (!dev) 1032 return -ENOMEM; 1033 1034 dev_net_set(dev, net); 1035 dev->rtnl_link_ops = &tun_link_ops; 1036 1037 tun = netdev_priv(dev); 1038 tun->dev = dev; 1039 tun->flags = flags; 1040 tun->txflt.count = 0; 1041 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr); 1042 1043 err = -ENOMEM; 1044 sk = sk_alloc(net, AF_UNSPEC, GFP_KERNEL, &tun_proto); 1045 if (!sk) 1046 goto err_free_dev; 1047 1048 tun->socket.wq = &tun->wq; 1049 init_waitqueue_head(&tun->wq.wait); 1050 tun->socket.ops = &tun_socket_ops; 1051 sock_init_data(&tun->socket, sk); 1052 sk->sk_write_space = tun_sock_write_space; 1053 sk->sk_sndbuf = INT_MAX; 1054 1055 tun_sk(sk)->tun = tun; 1056 1057 security_tun_dev_post_create(sk); 1058 1059 tun_net_init(dev); 1060 1061 if (strchr(dev->name, '%')) { 1062 err = dev_alloc_name(dev, dev->name); 1063 if (err < 0) 1064 goto err_free_sk; 1065 } 1066 1067 err = register_netdevice(tun->dev); 1068 if (err < 0) 1069 goto err_free_sk; 1070 1071 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) || 1072 device_create_file(&tun->dev->dev, &dev_attr_owner) || 1073 device_create_file(&tun->dev->dev, &dev_attr_group)) 1074 printk(KERN_ERR "Failed to create tun sysfs files\n"); 1075 1076 sk->sk_destruct = tun_sock_destruct; 1077 1078 err = tun_attach(tun, file); 1079 if (err < 0) 1080 goto failed; 1081 } 1082 1083 DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name); 1084 1085 if (ifr->ifr_flags & IFF_NO_PI) 1086 tun->flags |= TUN_NO_PI; 1087 else 1088 tun->flags &= ~TUN_NO_PI; 1089 1090 if (ifr->ifr_flags & IFF_ONE_QUEUE) 1091 tun->flags |= TUN_ONE_QUEUE; 1092 else 1093 tun->flags &= ~TUN_ONE_QUEUE; 1094 1095 if (ifr->ifr_flags & IFF_VNET_HDR) 1096 tun->flags |= TUN_VNET_HDR; 1097 else 1098 tun->flags &= ~TUN_VNET_HDR; 1099 1100 /* Make sure persistent devices do not get stuck in 1101 * xoff state. 1102 */ 1103 if (netif_running(tun->dev)) 1104 netif_wake_queue(tun->dev); 1105 1106 strcpy(ifr->ifr_name, tun->dev->name); 1107 return 0; 1108 1109 err_free_sk: 1110 sock_put(sk); 1111 err_free_dev: 1112 free_netdev(dev); 1113 failed: 1114 return err; 1115 } 1116 1117 static int tun_get_iff(struct net *net, struct tun_struct *tun, 1118 struct ifreq *ifr) 1119 { 1120 DBG(KERN_INFO "%s: tun_get_iff\n", tun->dev->name); 1121 1122 strcpy(ifr->ifr_name, tun->dev->name); 1123 1124 ifr->ifr_flags = tun_flags(tun); 1125 1126 return 0; 1127 } 1128 1129 /* This is like a cut-down ethtool ops, except done via tun fd so no 1130 * privs required. */ 1131 static int set_offload(struct net_device *dev, unsigned long arg) 1132 { 1133 unsigned int old_features, features; 1134 1135 old_features = dev->features; 1136 /* Unset features, set them as we chew on the arg. */ 1137 features = (old_features & ~(NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST 1138 |NETIF_F_TSO_ECN|NETIF_F_TSO|NETIF_F_TSO6 1139 |NETIF_F_UFO)); 1140 1141 if (arg & TUN_F_CSUM) { 1142 features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; 1143 arg &= ~TUN_F_CSUM; 1144 1145 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) { 1146 if (arg & TUN_F_TSO_ECN) { 1147 features |= NETIF_F_TSO_ECN; 1148 arg &= ~TUN_F_TSO_ECN; 1149 } 1150 if (arg & TUN_F_TSO4) 1151 features |= NETIF_F_TSO; 1152 if (arg & TUN_F_TSO6) 1153 features |= NETIF_F_TSO6; 1154 arg &= ~(TUN_F_TSO4|TUN_F_TSO6); 1155 } 1156 1157 if (arg & TUN_F_UFO) { 1158 features |= NETIF_F_UFO; 1159 arg &= ~TUN_F_UFO; 1160 } 1161 } 1162 1163 /* This gives the user a way to test for new features in future by 1164 * trying to set them. */ 1165 if (arg) 1166 return -EINVAL; 1167 1168 dev->features = features; 1169 if (old_features != dev->features) 1170 netdev_features_change(dev); 1171 1172 return 0; 1173 } 1174 1175 static long __tun_chr_ioctl(struct file *file, unsigned int cmd, 1176 unsigned long arg, int ifreq_len) 1177 { 1178 struct tun_file *tfile = file->private_data; 1179 struct tun_struct *tun; 1180 void __user* argp = (void __user*)arg; 1181 struct sock_fprog fprog; 1182 struct ifreq ifr; 1183 int sndbuf; 1184 int vnet_hdr_sz; 1185 int ret; 1186 1187 if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89) 1188 if (copy_from_user(&ifr, argp, ifreq_len)) 1189 return -EFAULT; 1190 1191 if (cmd == TUNGETFEATURES) { 1192 /* Currently this just means: "what IFF flags are valid?". 1193 * This is needed because we never checked for invalid flags on 1194 * TUNSETIFF. */ 1195 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE | 1196 IFF_VNET_HDR, 1197 (unsigned int __user*)argp); 1198 } 1199 1200 rtnl_lock(); 1201 1202 tun = __tun_get(tfile); 1203 if (cmd == TUNSETIFF && !tun) { 1204 ifr.ifr_name[IFNAMSIZ-1] = '\0'; 1205 1206 ret = tun_set_iff(tfile->net, file, &ifr); 1207 1208 if (ret) 1209 goto unlock; 1210 1211 if (copy_to_user(argp, &ifr, ifreq_len)) 1212 ret = -EFAULT; 1213 goto unlock; 1214 } 1215 1216 ret = -EBADFD; 1217 if (!tun) 1218 goto unlock; 1219 1220 DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd); 1221 1222 ret = 0; 1223 switch (cmd) { 1224 case TUNGETIFF: 1225 ret = tun_get_iff(current->nsproxy->net_ns, tun, &ifr); 1226 if (ret) 1227 break; 1228 1229 if (copy_to_user(argp, &ifr, ifreq_len)) 1230 ret = -EFAULT; 1231 break; 1232 1233 case TUNSETNOCSUM: 1234 /* Disable/Enable checksum */ 1235 if (arg) 1236 tun->flags |= TUN_NOCHECKSUM; 1237 else 1238 tun->flags &= ~TUN_NOCHECKSUM; 1239 1240 DBG(KERN_INFO "%s: checksum %s\n", 1241 tun->dev->name, arg ? "disabled" : "enabled"); 1242 break; 1243 1244 case TUNSETPERSIST: 1245 /* Disable/Enable persist mode */ 1246 if (arg) 1247 tun->flags |= TUN_PERSIST; 1248 else 1249 tun->flags &= ~TUN_PERSIST; 1250 1251 DBG(KERN_INFO "%s: persist %s\n", 1252 tun->dev->name, arg ? "enabled" : "disabled"); 1253 break; 1254 1255 case TUNSETOWNER: 1256 /* Set owner of the device */ 1257 tun->owner = (uid_t) arg; 1258 1259 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner); 1260 break; 1261 1262 case TUNSETGROUP: 1263 /* Set group of the device */ 1264 tun->group= (gid_t) arg; 1265 1266 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group); 1267 break; 1268 1269 case TUNSETLINK: 1270 /* Only allow setting the type when the interface is down */ 1271 if (tun->dev->flags & IFF_UP) { 1272 DBG(KERN_INFO "%s: Linktype set failed because interface is up\n", 1273 tun->dev->name); 1274 ret = -EBUSY; 1275 } else { 1276 tun->dev->type = (int) arg; 1277 DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type); 1278 ret = 0; 1279 } 1280 break; 1281 1282 #ifdef TUN_DEBUG 1283 case TUNSETDEBUG: 1284 tun->debug = arg; 1285 break; 1286 #endif 1287 case TUNSETOFFLOAD: 1288 ret = set_offload(tun->dev, arg); 1289 break; 1290 1291 case TUNSETTXFILTER: 1292 /* Can be set only for TAPs */ 1293 ret = -EINVAL; 1294 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV) 1295 break; 1296 ret = update_filter(&tun->txflt, (void __user *)arg); 1297 break; 1298 1299 case SIOCGIFHWADDR: 1300 /* Get hw addres */ 1301 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN); 1302 ifr.ifr_hwaddr.sa_family = tun->dev->type; 1303 if (copy_to_user(argp, &ifr, ifreq_len)) 1304 ret = -EFAULT; 1305 break; 1306 1307 case SIOCSIFHWADDR: 1308 /* Set hw address */ 1309 DBG(KERN_DEBUG "%s: set hw address: %pM\n", 1310 tun->dev->name, ifr.ifr_hwaddr.sa_data); 1311 1312 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr); 1313 break; 1314 1315 case TUNGETSNDBUF: 1316 sndbuf = tun->socket.sk->sk_sndbuf; 1317 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf))) 1318 ret = -EFAULT; 1319 break; 1320 1321 case TUNSETSNDBUF: 1322 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) { 1323 ret = -EFAULT; 1324 break; 1325 } 1326 1327 tun->socket.sk->sk_sndbuf = sndbuf; 1328 break; 1329 1330 case TUNGETVNETHDRSZ: 1331 vnet_hdr_sz = tun->vnet_hdr_sz; 1332 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz))) 1333 ret = -EFAULT; 1334 break; 1335 1336 case TUNSETVNETHDRSZ: 1337 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) { 1338 ret = -EFAULT; 1339 break; 1340 } 1341 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) { 1342 ret = -EINVAL; 1343 break; 1344 } 1345 1346 tun->vnet_hdr_sz = vnet_hdr_sz; 1347 break; 1348 1349 case TUNATTACHFILTER: 1350 /* Can be set only for TAPs */ 1351 ret = -EINVAL; 1352 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV) 1353 break; 1354 ret = -EFAULT; 1355 if (copy_from_user(&fprog, argp, sizeof(fprog))) 1356 break; 1357 1358 ret = sk_attach_filter(&fprog, tun->socket.sk); 1359 break; 1360 1361 case TUNDETACHFILTER: 1362 /* Can be set only for TAPs */ 1363 ret = -EINVAL; 1364 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV) 1365 break; 1366 ret = sk_detach_filter(tun->socket.sk); 1367 break; 1368 1369 default: 1370 ret = -EINVAL; 1371 break; 1372 } 1373 1374 unlock: 1375 rtnl_unlock(); 1376 if (tun) 1377 tun_put(tun); 1378 return ret; 1379 } 1380 1381 static long tun_chr_ioctl(struct file *file, 1382 unsigned int cmd, unsigned long arg) 1383 { 1384 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq)); 1385 } 1386 1387 #ifdef CONFIG_COMPAT 1388 static long tun_chr_compat_ioctl(struct file *file, 1389 unsigned int cmd, unsigned long arg) 1390 { 1391 switch (cmd) { 1392 case TUNSETIFF: 1393 case TUNGETIFF: 1394 case TUNSETTXFILTER: 1395 case TUNGETSNDBUF: 1396 case TUNSETSNDBUF: 1397 case SIOCGIFHWADDR: 1398 case SIOCSIFHWADDR: 1399 arg = (unsigned long)compat_ptr(arg); 1400 break; 1401 default: 1402 arg = (compat_ulong_t)arg; 1403 break; 1404 } 1405 1406 /* 1407 * compat_ifreq is shorter than ifreq, so we must not access beyond 1408 * the end of that structure. All fields that are used in this 1409 * driver are compatible though, we don't need to convert the 1410 * contents. 1411 */ 1412 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq)); 1413 } 1414 #endif /* CONFIG_COMPAT */ 1415 1416 static int tun_chr_fasync(int fd, struct file *file, int on) 1417 { 1418 struct tun_struct *tun = tun_get(file); 1419 int ret; 1420 1421 if (!tun) 1422 return -EBADFD; 1423 1424 DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on); 1425 1426 if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0) 1427 goto out; 1428 1429 if (on) { 1430 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0); 1431 if (ret) 1432 goto out; 1433 tun->flags |= TUN_FASYNC; 1434 } else 1435 tun->flags &= ~TUN_FASYNC; 1436 ret = 0; 1437 out: 1438 tun_put(tun); 1439 return ret; 1440 } 1441 1442 static int tun_chr_open(struct inode *inode, struct file * file) 1443 { 1444 struct tun_file *tfile; 1445 1446 DBG1(KERN_INFO "tunX: tun_chr_open\n"); 1447 1448 tfile = kmalloc(sizeof(*tfile), GFP_KERNEL); 1449 if (!tfile) 1450 return -ENOMEM; 1451 atomic_set(&tfile->count, 0); 1452 tfile->tun = NULL; 1453 tfile->net = get_net(current->nsproxy->net_ns); 1454 file->private_data = tfile; 1455 return 0; 1456 } 1457 1458 static int tun_chr_close(struct inode *inode, struct file *file) 1459 { 1460 struct tun_file *tfile = file->private_data; 1461 struct tun_struct *tun; 1462 1463 tun = __tun_get(tfile); 1464 if (tun) { 1465 struct net_device *dev = tun->dev; 1466 1467 DBG(KERN_INFO "%s: tun_chr_close\n", dev->name); 1468 1469 __tun_detach(tun); 1470 1471 /* If desirable, unregister the netdevice. */ 1472 if (!(tun->flags & TUN_PERSIST)) { 1473 rtnl_lock(); 1474 if (dev->reg_state == NETREG_REGISTERED) 1475 unregister_netdevice(dev); 1476 rtnl_unlock(); 1477 } 1478 } 1479 1480 tun = tfile->tun; 1481 if (tun) 1482 sock_put(tun->socket.sk); 1483 1484 put_net(tfile->net); 1485 kfree(tfile); 1486 1487 return 0; 1488 } 1489 1490 static const struct file_operations tun_fops = { 1491 .owner = THIS_MODULE, 1492 .llseek = no_llseek, 1493 .read = do_sync_read, 1494 .aio_read = tun_chr_aio_read, 1495 .write = do_sync_write, 1496 .aio_write = tun_chr_aio_write, 1497 .poll = tun_chr_poll, 1498 .unlocked_ioctl = tun_chr_ioctl, 1499 #ifdef CONFIG_COMPAT 1500 .compat_ioctl = tun_chr_compat_ioctl, 1501 #endif 1502 .open = tun_chr_open, 1503 .release = tun_chr_close, 1504 .fasync = tun_chr_fasync 1505 }; 1506 1507 static struct miscdevice tun_miscdev = { 1508 .minor = TUN_MINOR, 1509 .name = "tun", 1510 .nodename = "net/tun", 1511 .fops = &tun_fops, 1512 }; 1513 1514 /* ethtool interface */ 1515 1516 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd) 1517 { 1518 cmd->supported = 0; 1519 cmd->advertising = 0; 1520 cmd->speed = SPEED_10; 1521 cmd->duplex = DUPLEX_FULL; 1522 cmd->port = PORT_TP; 1523 cmd->phy_address = 0; 1524 cmd->transceiver = XCVR_INTERNAL; 1525 cmd->autoneg = AUTONEG_DISABLE; 1526 cmd->maxtxpkt = 0; 1527 cmd->maxrxpkt = 0; 1528 return 0; 1529 } 1530 1531 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info) 1532 { 1533 struct tun_struct *tun = netdev_priv(dev); 1534 1535 strcpy(info->driver, DRV_NAME); 1536 strcpy(info->version, DRV_VERSION); 1537 strcpy(info->fw_version, "N/A"); 1538 1539 switch (tun->flags & TUN_TYPE_MASK) { 1540 case TUN_TUN_DEV: 1541 strcpy(info->bus_info, "tun"); 1542 break; 1543 case TUN_TAP_DEV: 1544 strcpy(info->bus_info, "tap"); 1545 break; 1546 } 1547 } 1548 1549 static u32 tun_get_msglevel(struct net_device *dev) 1550 { 1551 #ifdef TUN_DEBUG 1552 struct tun_struct *tun = netdev_priv(dev); 1553 return tun->debug; 1554 #else 1555 return -EOPNOTSUPP; 1556 #endif 1557 } 1558 1559 static void tun_set_msglevel(struct net_device *dev, u32 value) 1560 { 1561 #ifdef TUN_DEBUG 1562 struct tun_struct *tun = netdev_priv(dev); 1563 tun->debug = value; 1564 #endif 1565 } 1566 1567 static u32 tun_get_link(struct net_device *dev) 1568 { 1569 struct tun_struct *tun = netdev_priv(dev); 1570 return !!tun->tfile; 1571 } 1572 1573 static u32 tun_get_rx_csum(struct net_device *dev) 1574 { 1575 struct tun_struct *tun = netdev_priv(dev); 1576 return (tun->flags & TUN_NOCHECKSUM) == 0; 1577 } 1578 1579 static int tun_set_rx_csum(struct net_device *dev, u32 data) 1580 { 1581 struct tun_struct *tun = netdev_priv(dev); 1582 if (data) 1583 tun->flags &= ~TUN_NOCHECKSUM; 1584 else 1585 tun->flags |= TUN_NOCHECKSUM; 1586 return 0; 1587 } 1588 1589 static const struct ethtool_ops tun_ethtool_ops = { 1590 .get_settings = tun_get_settings, 1591 .get_drvinfo = tun_get_drvinfo, 1592 .get_msglevel = tun_get_msglevel, 1593 .set_msglevel = tun_set_msglevel, 1594 .get_link = tun_get_link, 1595 .get_rx_csum = tun_get_rx_csum, 1596 .set_rx_csum = tun_set_rx_csum 1597 }; 1598 1599 1600 static int __init tun_init(void) 1601 { 1602 int ret = 0; 1603 1604 printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION); 1605 printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT); 1606 1607 ret = rtnl_link_register(&tun_link_ops); 1608 if (ret) { 1609 printk(KERN_ERR "tun: Can't register link_ops\n"); 1610 goto err_linkops; 1611 } 1612 1613 ret = misc_register(&tun_miscdev); 1614 if (ret) { 1615 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR); 1616 goto err_misc; 1617 } 1618 return 0; 1619 err_misc: 1620 rtnl_link_unregister(&tun_link_ops); 1621 err_linkops: 1622 return ret; 1623 } 1624 1625 static void tun_cleanup(void) 1626 { 1627 misc_deregister(&tun_miscdev); 1628 rtnl_link_unregister(&tun_link_ops); 1629 } 1630 1631 /* Get an underlying socket object from tun file. Returns error unless file is 1632 * attached to a device. The returned object works like a packet socket, it 1633 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for 1634 * holding a reference to the file for as long as the socket is in use. */ 1635 struct socket *tun_get_socket(struct file *file) 1636 { 1637 struct tun_struct *tun; 1638 if (file->f_op != &tun_fops) 1639 return ERR_PTR(-EINVAL); 1640 tun = tun_get(file); 1641 if (!tun) 1642 return ERR_PTR(-EBADFD); 1643 tun_put(tun); 1644 return &tun->socket; 1645 } 1646 EXPORT_SYMBOL_GPL(tun_get_socket); 1647 1648 module_init(tun_init); 1649 module_exit(tun_cleanup); 1650 MODULE_DESCRIPTION(DRV_DESCRIPTION); 1651 MODULE_AUTHOR(DRV_COPYRIGHT); 1652 MODULE_LICENSE("GPL"); 1653 MODULE_ALIAS_MISCDEV(TUN_MINOR); 1654 MODULE_ALIAS("devname:net/tun"); 1655