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