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