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/smp_lock.h> 48 #include <linux/poll.h> 49 #include <linux/fcntl.h> 50 #include <linux/init.h> 51 #include <linux/skbuff.h> 52 #include <linux/netdevice.h> 53 #include <linux/etherdevice.h> 54 #include <linux/miscdevice.h> 55 #include <linux/ethtool.h> 56 #include <linux/rtnetlink.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 67 #include <asm/system.h> 68 #include <asm/uaccess.h> 69 70 /* Uncomment to enable debugging */ 71 /* #define TUN_DEBUG 1 */ 72 73 #ifdef TUN_DEBUG 74 static int debug; 75 76 #define DBG if(tun->debug)printk 77 #define DBG1 if(debug==2)printk 78 #else 79 #define DBG( a... ) 80 #define DBG1( a... ) 81 #endif 82 83 #define FLT_EXACT_COUNT 8 84 struct tap_filter { 85 unsigned int count; /* Number of addrs. Zero means disabled */ 86 u32 mask[2]; /* Mask of the hashed addrs */ 87 unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN]; 88 }; 89 90 struct tun_struct { 91 struct list_head list; 92 unsigned int flags; 93 int attached; 94 uid_t owner; 95 gid_t group; 96 97 wait_queue_head_t read_wait; 98 struct sk_buff_head readq; 99 100 struct net_device *dev; 101 struct fasync_struct *fasync; 102 103 struct tap_filter txflt; 104 105 #ifdef TUN_DEBUG 106 int debug; 107 #endif 108 }; 109 110 /* TAP filterting */ 111 static void addr_hash_set(u32 *mask, const u8 *addr) 112 { 113 int n = ether_crc(ETH_ALEN, addr) >> 26; 114 mask[n >> 5] |= (1 << (n & 31)); 115 } 116 117 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr) 118 { 119 int n = ether_crc(ETH_ALEN, addr) >> 26; 120 return mask[n >> 5] & (1 << (n & 31)); 121 } 122 123 static int update_filter(struct tap_filter *filter, void __user *arg) 124 { 125 struct { u8 u[ETH_ALEN]; } *addr; 126 struct tun_filter uf; 127 int err, alen, n, nexact; 128 129 if (copy_from_user(&uf, arg, sizeof(uf))) 130 return -EFAULT; 131 132 if (!uf.count) { 133 /* Disabled */ 134 filter->count = 0; 135 return 0; 136 } 137 138 alen = ETH_ALEN * uf.count; 139 addr = kmalloc(alen, GFP_KERNEL); 140 if (!addr) 141 return -ENOMEM; 142 143 if (copy_from_user(addr, arg + sizeof(uf), alen)) { 144 err = -EFAULT; 145 goto done; 146 } 147 148 /* The filter is updated without holding any locks. Which is 149 * perfectly safe. We disable it first and in the worst 150 * case we'll accept a few undesired packets. */ 151 filter->count = 0; 152 wmb(); 153 154 /* Use first set of addresses as an exact filter */ 155 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++) 156 memcpy(filter->addr[n], addr[n].u, ETH_ALEN); 157 158 nexact = n; 159 160 /* The rest is hashed */ 161 memset(filter->mask, 0, sizeof(filter->mask)); 162 for (; n < uf.count; n++) 163 addr_hash_set(filter->mask, addr[n].u); 164 165 /* For ALLMULTI just set the mask to all ones. 166 * This overrides the mask populated above. */ 167 if ((uf.flags & TUN_FLT_ALLMULTI)) 168 memset(filter->mask, ~0, sizeof(filter->mask)); 169 170 /* Now enable the filter */ 171 wmb(); 172 filter->count = nexact; 173 174 /* Return the number of exact filters */ 175 err = nexact; 176 177 done: 178 kfree(addr); 179 return err; 180 } 181 182 /* Returns: 0 - drop, !=0 - accept */ 183 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb) 184 { 185 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect 186 * at this point. */ 187 struct ethhdr *eh = (struct ethhdr *) skb->data; 188 int i; 189 190 /* Exact match */ 191 for (i = 0; i < filter->count; i++) 192 if (!compare_ether_addr(eh->h_dest, filter->addr[i])) 193 return 1; 194 195 /* Inexact match (multicast only) */ 196 if (is_multicast_ether_addr(eh->h_dest)) 197 return addr_hash_test(filter->mask, eh->h_dest); 198 199 return 0; 200 } 201 202 /* 203 * Checks whether the packet is accepted or not. 204 * Returns: 0 - drop, !=0 - accept 205 */ 206 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb) 207 { 208 if (!filter->count) 209 return 1; 210 211 return run_filter(filter, skb); 212 } 213 214 /* Network device part of the driver */ 215 216 static unsigned int tun_net_id; 217 struct tun_net { 218 struct list_head dev_list; 219 }; 220 221 static const struct ethtool_ops tun_ethtool_ops; 222 223 /* Net device open. */ 224 static int tun_net_open(struct net_device *dev) 225 { 226 netif_start_queue(dev); 227 return 0; 228 } 229 230 /* Net device close. */ 231 static int tun_net_close(struct net_device *dev) 232 { 233 netif_stop_queue(dev); 234 return 0; 235 } 236 237 /* Net device start xmit */ 238 static int tun_net_xmit(struct sk_buff *skb, struct net_device *dev) 239 { 240 struct tun_struct *tun = netdev_priv(dev); 241 242 DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len); 243 244 /* Drop packet if interface is not attached */ 245 if (!tun->attached) 246 goto drop; 247 248 /* Drop if the filter does not like it. 249 * This is a noop if the filter is disabled. 250 * Filter can be enabled only for the TAP devices. */ 251 if (!check_filter(&tun->txflt, skb)) 252 goto drop; 253 254 if (skb_queue_len(&tun->readq) >= dev->tx_queue_len) { 255 if (!(tun->flags & TUN_ONE_QUEUE)) { 256 /* Normal queueing mode. */ 257 /* Packet scheduler handles dropping of further packets. */ 258 netif_stop_queue(dev); 259 260 /* We won't see all dropped packets individually, so overrun 261 * error is more appropriate. */ 262 dev->stats.tx_fifo_errors++; 263 } else { 264 /* Single queue mode. 265 * Driver handles dropping of all packets itself. */ 266 goto drop; 267 } 268 } 269 270 /* Enqueue packet */ 271 skb_queue_tail(&tun->readq, skb); 272 dev->trans_start = jiffies; 273 274 /* Notify and wake up reader process */ 275 if (tun->flags & TUN_FASYNC) 276 kill_fasync(&tun->fasync, SIGIO, POLL_IN); 277 wake_up_interruptible(&tun->read_wait); 278 return 0; 279 280 drop: 281 dev->stats.tx_dropped++; 282 kfree_skb(skb); 283 return 0; 284 } 285 286 static void tun_net_mclist(struct net_device *dev) 287 { 288 /* 289 * This callback is supposed to deal with mc filter in 290 * _rx_ path and has nothing to do with the _tx_ path. 291 * In rx path we always accept everything userspace gives us. 292 */ 293 return; 294 } 295 296 #define MIN_MTU 68 297 #define MAX_MTU 65535 298 299 static int 300 tun_net_change_mtu(struct net_device *dev, int new_mtu) 301 { 302 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU) 303 return -EINVAL; 304 dev->mtu = new_mtu; 305 return 0; 306 } 307 308 /* Initialize net device. */ 309 static void tun_net_init(struct net_device *dev) 310 { 311 struct tun_struct *tun = netdev_priv(dev); 312 313 switch (tun->flags & TUN_TYPE_MASK) { 314 case TUN_TUN_DEV: 315 /* Point-to-Point TUN Device */ 316 dev->hard_header_len = 0; 317 dev->addr_len = 0; 318 dev->mtu = 1500; 319 dev->change_mtu = tun_net_change_mtu; 320 321 /* Zero header length */ 322 dev->type = ARPHRD_NONE; 323 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 324 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */ 325 break; 326 327 case TUN_TAP_DEV: 328 /* Ethernet TAP Device */ 329 ether_setup(dev); 330 dev->change_mtu = tun_net_change_mtu; 331 dev->set_multicast_list = tun_net_mclist; 332 333 random_ether_addr(dev->dev_addr); 334 335 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */ 336 break; 337 } 338 } 339 340 /* Character device part */ 341 342 /* Poll */ 343 static unsigned int tun_chr_poll(struct file *file, poll_table * wait) 344 { 345 struct tun_struct *tun = file->private_data; 346 unsigned int mask = POLLOUT | POLLWRNORM; 347 348 if (!tun) 349 return -EBADFD; 350 351 DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name); 352 353 poll_wait(file, &tun->read_wait, wait); 354 355 if (!skb_queue_empty(&tun->readq)) 356 mask |= POLLIN | POLLRDNORM; 357 358 return mask; 359 } 360 361 /* Get packet from user space buffer */ 362 static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, size_t count) 363 { 364 struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) }; 365 struct sk_buff *skb; 366 size_t len = count, align = 0; 367 struct virtio_net_hdr gso = { 0 }; 368 369 if (!(tun->flags & TUN_NO_PI)) { 370 if ((len -= sizeof(pi)) > count) 371 return -EINVAL; 372 373 if(memcpy_fromiovec((void *)&pi, iv, sizeof(pi))) 374 return -EFAULT; 375 } 376 377 if (tun->flags & TUN_VNET_HDR) { 378 if ((len -= sizeof(gso)) > count) 379 return -EINVAL; 380 381 if (memcpy_fromiovec((void *)&gso, iv, sizeof(gso))) 382 return -EFAULT; 383 384 if (gso.hdr_len > len) 385 return -EINVAL; 386 } 387 388 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) { 389 align = NET_IP_ALIGN; 390 if (unlikely(len < ETH_HLEN)) 391 return -EINVAL; 392 } 393 394 if (!(skb = alloc_skb(len + align, GFP_KERNEL))) { 395 tun->dev->stats.rx_dropped++; 396 return -ENOMEM; 397 } 398 399 if (align) 400 skb_reserve(skb, align); 401 if (memcpy_fromiovec(skb_put(skb, len), iv, len)) { 402 tun->dev->stats.rx_dropped++; 403 kfree_skb(skb); 404 return -EFAULT; 405 } 406 407 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 408 if (!skb_partial_csum_set(skb, gso.csum_start, 409 gso.csum_offset)) { 410 tun->dev->stats.rx_frame_errors++; 411 kfree_skb(skb); 412 return -EINVAL; 413 } 414 } else if (tun->flags & TUN_NOCHECKSUM) 415 skb->ip_summed = CHECKSUM_UNNECESSARY; 416 417 switch (tun->flags & TUN_TYPE_MASK) { 418 case TUN_TUN_DEV: 419 if (tun->flags & TUN_NO_PI) { 420 switch (skb->data[0] & 0xf0) { 421 case 0x40: 422 pi.proto = htons(ETH_P_IP); 423 break; 424 case 0x60: 425 pi.proto = htons(ETH_P_IPV6); 426 break; 427 default: 428 tun->dev->stats.rx_dropped++; 429 kfree_skb(skb); 430 return -EINVAL; 431 } 432 } 433 434 skb_reset_mac_header(skb); 435 skb->protocol = pi.proto; 436 skb->dev = tun->dev; 437 break; 438 case TUN_TAP_DEV: 439 skb->protocol = eth_type_trans(skb, tun->dev); 440 break; 441 }; 442 443 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 444 pr_debug("GSO!\n"); 445 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 446 case VIRTIO_NET_HDR_GSO_TCPV4: 447 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; 448 break; 449 case VIRTIO_NET_HDR_GSO_TCPV6: 450 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; 451 break; 452 default: 453 tun->dev->stats.rx_frame_errors++; 454 kfree_skb(skb); 455 return -EINVAL; 456 } 457 458 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN) 459 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; 460 461 skb_shinfo(skb)->gso_size = gso.gso_size; 462 if (skb_shinfo(skb)->gso_size == 0) { 463 tun->dev->stats.rx_frame_errors++; 464 kfree_skb(skb); 465 return -EINVAL; 466 } 467 468 /* Header must be checked, and gso_segs computed. */ 469 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 470 skb_shinfo(skb)->gso_segs = 0; 471 } 472 473 netif_rx_ni(skb); 474 tun->dev->last_rx = jiffies; 475 476 tun->dev->stats.rx_packets++; 477 tun->dev->stats.rx_bytes += len; 478 479 return count; 480 } 481 482 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv, 483 unsigned long count, loff_t pos) 484 { 485 struct tun_struct *tun = iocb->ki_filp->private_data; 486 487 if (!tun) 488 return -EBADFD; 489 490 DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count); 491 492 return tun_get_user(tun, (struct iovec *) iv, iov_length(iv, count)); 493 } 494 495 /* Put packet to the user space buffer */ 496 static __inline__ ssize_t tun_put_user(struct tun_struct *tun, 497 struct sk_buff *skb, 498 struct iovec *iv, int len) 499 { 500 struct tun_pi pi = { 0, skb->protocol }; 501 ssize_t total = 0; 502 503 if (!(tun->flags & TUN_NO_PI)) { 504 if ((len -= sizeof(pi)) < 0) 505 return -EINVAL; 506 507 if (len < skb->len) { 508 /* Packet will be striped */ 509 pi.flags |= TUN_PKT_STRIP; 510 } 511 512 if (memcpy_toiovec(iv, (void *) &pi, sizeof(pi))) 513 return -EFAULT; 514 total += sizeof(pi); 515 } 516 517 if (tun->flags & TUN_VNET_HDR) { 518 struct virtio_net_hdr gso = { 0 }; /* no info leak */ 519 if ((len -= sizeof(gso)) < 0) 520 return -EINVAL; 521 522 if (skb_is_gso(skb)) { 523 struct skb_shared_info *sinfo = skb_shinfo(skb); 524 525 /* This is a hint as to how much should be linear. */ 526 gso.hdr_len = skb_headlen(skb); 527 gso.gso_size = sinfo->gso_size; 528 if (sinfo->gso_type & SKB_GSO_TCPV4) 529 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 530 else if (sinfo->gso_type & SKB_GSO_TCPV6) 531 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 532 else 533 BUG(); 534 if (sinfo->gso_type & SKB_GSO_TCP_ECN) 535 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 536 } else 537 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE; 538 539 if (skb->ip_summed == CHECKSUM_PARTIAL) { 540 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 541 gso.csum_start = skb->csum_start - skb_headroom(skb); 542 gso.csum_offset = skb->csum_offset; 543 } /* else everything is zero */ 544 545 if (unlikely(memcpy_toiovec(iv, (void *)&gso, sizeof(gso)))) 546 return -EFAULT; 547 total += sizeof(gso); 548 } 549 550 len = min_t(int, skb->len, len); 551 552 skb_copy_datagram_iovec(skb, 0, iv, len); 553 total += len; 554 555 tun->dev->stats.tx_packets++; 556 tun->dev->stats.tx_bytes += len; 557 558 return total; 559 } 560 561 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv, 562 unsigned long count, loff_t pos) 563 { 564 struct file *file = iocb->ki_filp; 565 struct tun_struct *tun = file->private_data; 566 DECLARE_WAITQUEUE(wait, current); 567 struct sk_buff *skb; 568 ssize_t len, ret = 0; 569 570 if (!tun) 571 return -EBADFD; 572 573 DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name); 574 575 len = iov_length(iv, count); 576 if (len < 0) 577 return -EINVAL; 578 579 add_wait_queue(&tun->read_wait, &wait); 580 while (len) { 581 current->state = TASK_INTERRUPTIBLE; 582 583 /* Read frames from the queue */ 584 if (!(skb=skb_dequeue(&tun->readq))) { 585 if (file->f_flags & O_NONBLOCK) { 586 ret = -EAGAIN; 587 break; 588 } 589 if (signal_pending(current)) { 590 ret = -ERESTARTSYS; 591 break; 592 } 593 594 /* Nothing to read, let's sleep */ 595 schedule(); 596 continue; 597 } 598 netif_wake_queue(tun->dev); 599 600 ret = tun_put_user(tun, skb, (struct iovec *) iv, len); 601 kfree_skb(skb); 602 break; 603 } 604 605 current->state = TASK_RUNNING; 606 remove_wait_queue(&tun->read_wait, &wait); 607 608 return ret; 609 } 610 611 static void tun_setup(struct net_device *dev) 612 { 613 struct tun_struct *tun = netdev_priv(dev); 614 615 skb_queue_head_init(&tun->readq); 616 init_waitqueue_head(&tun->read_wait); 617 618 tun->owner = -1; 619 tun->group = -1; 620 621 dev->open = tun_net_open; 622 dev->hard_start_xmit = tun_net_xmit; 623 dev->stop = tun_net_close; 624 dev->ethtool_ops = &tun_ethtool_ops; 625 dev->destructor = free_netdev; 626 dev->features |= NETIF_F_NETNS_LOCAL; 627 } 628 629 static struct tun_struct *tun_get_by_name(struct tun_net *tn, const char *name) 630 { 631 struct tun_struct *tun; 632 633 ASSERT_RTNL(); 634 list_for_each_entry(tun, &tn->dev_list, list) { 635 if (!strncmp(tun->dev->name, name, IFNAMSIZ)) 636 return tun; 637 } 638 639 return NULL; 640 } 641 642 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) 643 { 644 struct tun_net *tn; 645 struct tun_struct *tun; 646 struct net_device *dev; 647 int err; 648 649 tn = net_generic(net, tun_net_id); 650 tun = tun_get_by_name(tn, ifr->ifr_name); 651 if (tun) { 652 if (tun->attached) 653 return -EBUSY; 654 655 /* Check permissions */ 656 if (((tun->owner != -1 && 657 current->euid != tun->owner) || 658 (tun->group != -1 && 659 current->egid != tun->group)) && 660 !capable(CAP_NET_ADMIN)) 661 return -EPERM; 662 } 663 else if (__dev_get_by_name(net, ifr->ifr_name)) 664 return -EINVAL; 665 else { 666 char *name; 667 unsigned long flags = 0; 668 669 err = -EINVAL; 670 671 if (!capable(CAP_NET_ADMIN)) 672 return -EPERM; 673 674 /* Set dev type */ 675 if (ifr->ifr_flags & IFF_TUN) { 676 /* TUN device */ 677 flags |= TUN_TUN_DEV; 678 name = "tun%d"; 679 } else if (ifr->ifr_flags & IFF_TAP) { 680 /* TAP device */ 681 flags |= TUN_TAP_DEV; 682 name = "tap%d"; 683 } else 684 goto failed; 685 686 if (*ifr->ifr_name) 687 name = ifr->ifr_name; 688 689 dev = alloc_netdev(sizeof(struct tun_struct), name, 690 tun_setup); 691 if (!dev) 692 return -ENOMEM; 693 694 dev_net_set(dev, net); 695 tun = netdev_priv(dev); 696 tun->dev = dev; 697 tun->flags = flags; 698 tun->txflt.count = 0; 699 700 tun_net_init(dev); 701 702 if (strchr(dev->name, '%')) { 703 err = dev_alloc_name(dev, dev->name); 704 if (err < 0) 705 goto err_free_dev; 706 } 707 708 err = register_netdevice(tun->dev); 709 if (err < 0) 710 goto err_free_dev; 711 712 list_add(&tun->list, &tn->dev_list); 713 } 714 715 DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name); 716 717 if (ifr->ifr_flags & IFF_NO_PI) 718 tun->flags |= TUN_NO_PI; 719 else 720 tun->flags &= ~TUN_NO_PI; 721 722 if (ifr->ifr_flags & IFF_ONE_QUEUE) 723 tun->flags |= TUN_ONE_QUEUE; 724 else 725 tun->flags &= ~TUN_ONE_QUEUE; 726 727 if (ifr->ifr_flags & IFF_VNET_HDR) 728 tun->flags |= TUN_VNET_HDR; 729 else 730 tun->flags &= ~TUN_VNET_HDR; 731 732 file->private_data = tun; 733 tun->attached = 1; 734 get_net(dev_net(tun->dev)); 735 736 /* Make sure persistent devices do not get stuck in 737 * xoff state. 738 */ 739 if (netif_running(tun->dev)) 740 netif_wake_queue(tun->dev); 741 742 strcpy(ifr->ifr_name, tun->dev->name); 743 return 0; 744 745 err_free_dev: 746 free_netdev(dev); 747 failed: 748 return err; 749 } 750 751 /* This is like a cut-down ethtool ops, except done via tun fd so no 752 * privs required. */ 753 static int set_offload(struct net_device *dev, unsigned long arg) 754 { 755 unsigned int old_features, features; 756 757 old_features = dev->features; 758 /* Unset features, set them as we chew on the arg. */ 759 features = (old_features & ~(NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST 760 |NETIF_F_TSO_ECN|NETIF_F_TSO|NETIF_F_TSO6)); 761 762 if (arg & TUN_F_CSUM) { 763 features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; 764 arg &= ~TUN_F_CSUM; 765 766 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) { 767 if (arg & TUN_F_TSO_ECN) { 768 features |= NETIF_F_TSO_ECN; 769 arg &= ~TUN_F_TSO_ECN; 770 } 771 if (arg & TUN_F_TSO4) 772 features |= NETIF_F_TSO; 773 if (arg & TUN_F_TSO6) 774 features |= NETIF_F_TSO6; 775 arg &= ~(TUN_F_TSO4|TUN_F_TSO6); 776 } 777 } 778 779 /* This gives the user a way to test for new features in future by 780 * trying to set them. */ 781 if (arg) 782 return -EINVAL; 783 784 dev->features = features; 785 if (old_features != dev->features) 786 netdev_features_change(dev); 787 788 return 0; 789 } 790 791 static int tun_chr_ioctl(struct inode *inode, struct file *file, 792 unsigned int cmd, unsigned long arg) 793 { 794 struct tun_struct *tun = file->private_data; 795 void __user* argp = (void __user*)arg; 796 struct ifreq ifr; 797 int ret; 798 DECLARE_MAC_BUF(mac); 799 800 if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89) 801 if (copy_from_user(&ifr, argp, sizeof ifr)) 802 return -EFAULT; 803 804 if (cmd == TUNSETIFF && !tun) { 805 int err; 806 807 ifr.ifr_name[IFNAMSIZ-1] = '\0'; 808 809 rtnl_lock(); 810 err = tun_set_iff(current->nsproxy->net_ns, file, &ifr); 811 rtnl_unlock(); 812 813 if (err) 814 return err; 815 816 if (copy_to_user(argp, &ifr, sizeof(ifr))) 817 return -EFAULT; 818 return 0; 819 } 820 821 if (cmd == TUNGETFEATURES) { 822 /* Currently this just means: "what IFF flags are valid?". 823 * This is needed because we never checked for invalid flags on 824 * TUNSETIFF. */ 825 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE | 826 IFF_VNET_HDR, 827 (unsigned int __user*)argp); 828 } 829 830 if (!tun) 831 return -EBADFD; 832 833 DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd); 834 835 switch (cmd) { 836 case TUNSETNOCSUM: 837 /* Disable/Enable checksum */ 838 if (arg) 839 tun->flags |= TUN_NOCHECKSUM; 840 else 841 tun->flags &= ~TUN_NOCHECKSUM; 842 843 DBG(KERN_INFO "%s: checksum %s\n", 844 tun->dev->name, arg ? "disabled" : "enabled"); 845 break; 846 847 case TUNSETPERSIST: 848 /* Disable/Enable persist mode */ 849 if (arg) 850 tun->flags |= TUN_PERSIST; 851 else 852 tun->flags &= ~TUN_PERSIST; 853 854 DBG(KERN_INFO "%s: persist %s\n", 855 tun->dev->name, arg ? "enabled" : "disabled"); 856 break; 857 858 case TUNSETOWNER: 859 /* Set owner of the device */ 860 tun->owner = (uid_t) arg; 861 862 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner); 863 break; 864 865 case TUNSETGROUP: 866 /* Set group of the device */ 867 tun->group= (gid_t) arg; 868 869 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group); 870 break; 871 872 case TUNSETLINK: 873 /* Only allow setting the type when the interface is down */ 874 rtnl_lock(); 875 if (tun->dev->flags & IFF_UP) { 876 DBG(KERN_INFO "%s: Linktype set failed because interface is up\n", 877 tun->dev->name); 878 ret = -EBUSY; 879 } else { 880 tun->dev->type = (int) arg; 881 DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type); 882 ret = 0; 883 } 884 rtnl_unlock(); 885 return ret; 886 887 #ifdef TUN_DEBUG 888 case TUNSETDEBUG: 889 tun->debug = arg; 890 break; 891 #endif 892 case TUNSETOFFLOAD: 893 rtnl_lock(); 894 ret = set_offload(tun->dev, arg); 895 rtnl_unlock(); 896 return ret; 897 898 case TUNSETTXFILTER: 899 /* Can be set only for TAPs */ 900 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV) 901 return -EINVAL; 902 rtnl_lock(); 903 ret = update_filter(&tun->txflt, (void __user *)arg); 904 rtnl_unlock(); 905 return ret; 906 907 case SIOCGIFHWADDR: 908 /* Get hw addres */ 909 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN); 910 ifr.ifr_hwaddr.sa_family = tun->dev->type; 911 if (copy_to_user(argp, &ifr, sizeof ifr)) 912 return -EFAULT; 913 return 0; 914 915 case SIOCSIFHWADDR: 916 /* Set hw address */ 917 DBG(KERN_DEBUG "%s: set hw address: %s\n", 918 tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data)); 919 920 rtnl_lock(); 921 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr); 922 rtnl_unlock(); 923 return ret; 924 925 default: 926 return -EINVAL; 927 }; 928 929 return 0; 930 } 931 932 static int tun_chr_fasync(int fd, struct file *file, int on) 933 { 934 struct tun_struct *tun = file->private_data; 935 int ret; 936 937 if (!tun) 938 return -EBADFD; 939 940 DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on); 941 942 lock_kernel(); 943 if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0) 944 goto out; 945 946 if (on) { 947 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0); 948 if (ret) 949 goto out; 950 tun->flags |= TUN_FASYNC; 951 } else 952 tun->flags &= ~TUN_FASYNC; 953 ret = 0; 954 out: 955 unlock_kernel(); 956 return ret; 957 } 958 959 static int tun_chr_open(struct inode *inode, struct file * file) 960 { 961 cycle_kernel_lock(); 962 DBG1(KERN_INFO "tunX: tun_chr_open\n"); 963 file->private_data = NULL; 964 return 0; 965 } 966 967 static int tun_chr_close(struct inode *inode, struct file *file) 968 { 969 struct tun_struct *tun = file->private_data; 970 971 if (!tun) 972 return 0; 973 974 DBG(KERN_INFO "%s: tun_chr_close\n", tun->dev->name); 975 976 tun_chr_fasync(-1, file, 0); 977 978 rtnl_lock(); 979 980 /* Detach from net device */ 981 file->private_data = NULL; 982 tun->attached = 0; 983 put_net(dev_net(tun->dev)); 984 985 /* Drop read queue */ 986 skb_queue_purge(&tun->readq); 987 988 if (!(tun->flags & TUN_PERSIST)) { 989 list_del(&tun->list); 990 unregister_netdevice(tun->dev); 991 } 992 993 rtnl_unlock(); 994 995 return 0; 996 } 997 998 static const struct file_operations tun_fops = { 999 .owner = THIS_MODULE, 1000 .llseek = no_llseek, 1001 .read = do_sync_read, 1002 .aio_read = tun_chr_aio_read, 1003 .write = do_sync_write, 1004 .aio_write = tun_chr_aio_write, 1005 .poll = tun_chr_poll, 1006 .ioctl = tun_chr_ioctl, 1007 .open = tun_chr_open, 1008 .release = tun_chr_close, 1009 .fasync = tun_chr_fasync 1010 }; 1011 1012 static struct miscdevice tun_miscdev = { 1013 .minor = TUN_MINOR, 1014 .name = "tun", 1015 .fops = &tun_fops, 1016 }; 1017 1018 /* ethtool interface */ 1019 1020 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd) 1021 { 1022 cmd->supported = 0; 1023 cmd->advertising = 0; 1024 cmd->speed = SPEED_10; 1025 cmd->duplex = DUPLEX_FULL; 1026 cmd->port = PORT_TP; 1027 cmd->phy_address = 0; 1028 cmd->transceiver = XCVR_INTERNAL; 1029 cmd->autoneg = AUTONEG_DISABLE; 1030 cmd->maxtxpkt = 0; 1031 cmd->maxrxpkt = 0; 1032 return 0; 1033 } 1034 1035 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info) 1036 { 1037 struct tun_struct *tun = netdev_priv(dev); 1038 1039 strcpy(info->driver, DRV_NAME); 1040 strcpy(info->version, DRV_VERSION); 1041 strcpy(info->fw_version, "N/A"); 1042 1043 switch (tun->flags & TUN_TYPE_MASK) { 1044 case TUN_TUN_DEV: 1045 strcpy(info->bus_info, "tun"); 1046 break; 1047 case TUN_TAP_DEV: 1048 strcpy(info->bus_info, "tap"); 1049 break; 1050 } 1051 } 1052 1053 static u32 tun_get_msglevel(struct net_device *dev) 1054 { 1055 #ifdef TUN_DEBUG 1056 struct tun_struct *tun = netdev_priv(dev); 1057 return tun->debug; 1058 #else 1059 return -EOPNOTSUPP; 1060 #endif 1061 } 1062 1063 static void tun_set_msglevel(struct net_device *dev, u32 value) 1064 { 1065 #ifdef TUN_DEBUG 1066 struct tun_struct *tun = netdev_priv(dev); 1067 tun->debug = value; 1068 #endif 1069 } 1070 1071 static u32 tun_get_link(struct net_device *dev) 1072 { 1073 struct tun_struct *tun = netdev_priv(dev); 1074 return tun->attached; 1075 } 1076 1077 static u32 tun_get_rx_csum(struct net_device *dev) 1078 { 1079 struct tun_struct *tun = netdev_priv(dev); 1080 return (tun->flags & TUN_NOCHECKSUM) == 0; 1081 } 1082 1083 static int tun_set_rx_csum(struct net_device *dev, u32 data) 1084 { 1085 struct tun_struct *tun = netdev_priv(dev); 1086 if (data) 1087 tun->flags &= ~TUN_NOCHECKSUM; 1088 else 1089 tun->flags |= TUN_NOCHECKSUM; 1090 return 0; 1091 } 1092 1093 static const struct ethtool_ops tun_ethtool_ops = { 1094 .get_settings = tun_get_settings, 1095 .get_drvinfo = tun_get_drvinfo, 1096 .get_msglevel = tun_get_msglevel, 1097 .set_msglevel = tun_set_msglevel, 1098 .get_link = tun_get_link, 1099 .get_rx_csum = tun_get_rx_csum, 1100 .set_rx_csum = tun_set_rx_csum 1101 }; 1102 1103 static int tun_init_net(struct net *net) 1104 { 1105 struct tun_net *tn; 1106 1107 tn = kmalloc(sizeof(*tn), GFP_KERNEL); 1108 if (tn == NULL) 1109 return -ENOMEM; 1110 1111 INIT_LIST_HEAD(&tn->dev_list); 1112 1113 if (net_assign_generic(net, tun_net_id, tn)) { 1114 kfree(tn); 1115 return -ENOMEM; 1116 } 1117 1118 return 0; 1119 } 1120 1121 static void tun_exit_net(struct net *net) 1122 { 1123 struct tun_net *tn; 1124 struct tun_struct *tun, *nxt; 1125 1126 tn = net_generic(net, tun_net_id); 1127 1128 rtnl_lock(); 1129 list_for_each_entry_safe(tun, nxt, &tn->dev_list, list) { 1130 DBG(KERN_INFO "%s cleaned up\n", tun->dev->name); 1131 unregister_netdevice(tun->dev); 1132 } 1133 rtnl_unlock(); 1134 1135 kfree(tn); 1136 } 1137 1138 static struct pernet_operations tun_net_ops = { 1139 .init = tun_init_net, 1140 .exit = tun_exit_net, 1141 }; 1142 1143 static int __init tun_init(void) 1144 { 1145 int ret = 0; 1146 1147 printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION); 1148 printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT); 1149 1150 ret = register_pernet_gen_device(&tun_net_id, &tun_net_ops); 1151 if (ret) { 1152 printk(KERN_ERR "tun: Can't register pernet ops\n"); 1153 goto err_pernet; 1154 } 1155 1156 ret = misc_register(&tun_miscdev); 1157 if (ret) { 1158 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR); 1159 goto err_misc; 1160 } 1161 return 0; 1162 1163 err_misc: 1164 unregister_pernet_gen_device(tun_net_id, &tun_net_ops); 1165 err_pernet: 1166 return ret; 1167 } 1168 1169 static void tun_cleanup(void) 1170 { 1171 misc_deregister(&tun_miscdev); 1172 unregister_pernet_gen_device(tun_net_id, &tun_net_ops); 1173 } 1174 1175 module_init(tun_init); 1176 module_exit(tun_cleanup); 1177 MODULE_DESCRIPTION(DRV_DESCRIPTION); 1178 MODULE_AUTHOR(DRV_COPYRIGHT); 1179 MODULE_LICENSE("GPL"); 1180 MODULE_ALIAS_MISCDEV(TUN_MINOR); 1181