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 /* prepad is the amount to reserve at front. len is length after that. 362 * linear is a hint as to how much to copy (usually headers). */ 363 static struct sk_buff *tun_alloc_skb(size_t prepad, size_t len, size_t linear, 364 gfp_t gfp) 365 { 366 struct sk_buff *skb; 367 unsigned int i; 368 369 skb = alloc_skb(prepad + len, gfp|__GFP_NOWARN); 370 if (skb) { 371 skb_reserve(skb, prepad); 372 skb_put(skb, len); 373 return skb; 374 } 375 376 /* Under a page? Don't bother with paged skb. */ 377 if (prepad + len < PAGE_SIZE) 378 return NULL; 379 380 /* Start with a normal skb, and add pages. */ 381 skb = alloc_skb(prepad + linear, gfp); 382 if (!skb) 383 return NULL; 384 385 skb_reserve(skb, prepad); 386 skb_put(skb, linear); 387 388 len -= linear; 389 390 for (i = 0; i < MAX_SKB_FRAGS; i++) { 391 skb_frag_t *f = &skb_shinfo(skb)->frags[i]; 392 393 f->page = alloc_page(gfp|__GFP_ZERO); 394 if (!f->page) 395 break; 396 397 f->page_offset = 0; 398 f->size = PAGE_SIZE; 399 400 skb->data_len += PAGE_SIZE; 401 skb->len += PAGE_SIZE; 402 skb->truesize += PAGE_SIZE; 403 skb_shinfo(skb)->nr_frags++; 404 405 if (len < PAGE_SIZE) { 406 len = 0; 407 break; 408 } 409 len -= PAGE_SIZE; 410 } 411 412 /* Too large, or alloc fail? */ 413 if (unlikely(len)) { 414 kfree_skb(skb); 415 skb = NULL; 416 } 417 418 return skb; 419 } 420 421 /* Get packet from user space buffer */ 422 static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, size_t count) 423 { 424 struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) }; 425 struct sk_buff *skb; 426 size_t len = count, align = 0; 427 struct virtio_net_hdr gso = { 0 }; 428 429 if (!(tun->flags & TUN_NO_PI)) { 430 if ((len -= sizeof(pi)) > count) 431 return -EINVAL; 432 433 if(memcpy_fromiovec((void *)&pi, iv, sizeof(pi))) 434 return -EFAULT; 435 } 436 437 if (tun->flags & TUN_VNET_HDR) { 438 if ((len -= sizeof(gso)) > count) 439 return -EINVAL; 440 441 if (memcpy_fromiovec((void *)&gso, iv, sizeof(gso))) 442 return -EFAULT; 443 444 if (gso.hdr_len > len) 445 return -EINVAL; 446 } 447 448 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) { 449 align = NET_IP_ALIGN; 450 if (unlikely(len < ETH_HLEN)) 451 return -EINVAL; 452 } 453 454 if (!(skb = tun_alloc_skb(align, len, gso.hdr_len, GFP_KERNEL))) { 455 tun->dev->stats.rx_dropped++; 456 return -ENOMEM; 457 } 458 459 if (skb_copy_datagram_from_iovec(skb, 0, iv, len)) { 460 tun->dev->stats.rx_dropped++; 461 kfree_skb(skb); 462 return -EFAULT; 463 } 464 465 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 466 if (!skb_partial_csum_set(skb, gso.csum_start, 467 gso.csum_offset)) { 468 tun->dev->stats.rx_frame_errors++; 469 kfree_skb(skb); 470 return -EINVAL; 471 } 472 } else if (tun->flags & TUN_NOCHECKSUM) 473 skb->ip_summed = CHECKSUM_UNNECESSARY; 474 475 switch (tun->flags & TUN_TYPE_MASK) { 476 case TUN_TUN_DEV: 477 if (tun->flags & TUN_NO_PI) { 478 switch (skb->data[0] & 0xf0) { 479 case 0x40: 480 pi.proto = htons(ETH_P_IP); 481 break; 482 case 0x60: 483 pi.proto = htons(ETH_P_IPV6); 484 break; 485 default: 486 tun->dev->stats.rx_dropped++; 487 kfree_skb(skb); 488 return -EINVAL; 489 } 490 } 491 492 skb_reset_mac_header(skb); 493 skb->protocol = pi.proto; 494 skb->dev = tun->dev; 495 break; 496 case TUN_TAP_DEV: 497 skb->protocol = eth_type_trans(skb, tun->dev); 498 break; 499 }; 500 501 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 502 pr_debug("GSO!\n"); 503 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 504 case VIRTIO_NET_HDR_GSO_TCPV4: 505 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; 506 break; 507 case VIRTIO_NET_HDR_GSO_TCPV6: 508 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; 509 break; 510 default: 511 tun->dev->stats.rx_frame_errors++; 512 kfree_skb(skb); 513 return -EINVAL; 514 } 515 516 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN) 517 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; 518 519 skb_shinfo(skb)->gso_size = gso.gso_size; 520 if (skb_shinfo(skb)->gso_size == 0) { 521 tun->dev->stats.rx_frame_errors++; 522 kfree_skb(skb); 523 return -EINVAL; 524 } 525 526 /* Header must be checked, and gso_segs computed. */ 527 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 528 skb_shinfo(skb)->gso_segs = 0; 529 } 530 531 netif_rx_ni(skb); 532 tun->dev->last_rx = jiffies; 533 534 tun->dev->stats.rx_packets++; 535 tun->dev->stats.rx_bytes += len; 536 537 return count; 538 } 539 540 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv, 541 unsigned long count, loff_t pos) 542 { 543 struct tun_struct *tun = iocb->ki_filp->private_data; 544 545 if (!tun) 546 return -EBADFD; 547 548 DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count); 549 550 return tun_get_user(tun, (struct iovec *) iv, iov_length(iv, count)); 551 } 552 553 /* Put packet to the user space buffer */ 554 static __inline__ ssize_t tun_put_user(struct tun_struct *tun, 555 struct sk_buff *skb, 556 struct iovec *iv, int len) 557 { 558 struct tun_pi pi = { 0, skb->protocol }; 559 ssize_t total = 0; 560 561 if (!(tun->flags & TUN_NO_PI)) { 562 if ((len -= sizeof(pi)) < 0) 563 return -EINVAL; 564 565 if (len < skb->len) { 566 /* Packet will be striped */ 567 pi.flags |= TUN_PKT_STRIP; 568 } 569 570 if (memcpy_toiovec(iv, (void *) &pi, sizeof(pi))) 571 return -EFAULT; 572 total += sizeof(pi); 573 } 574 575 if (tun->flags & TUN_VNET_HDR) { 576 struct virtio_net_hdr gso = { 0 }; /* no info leak */ 577 if ((len -= sizeof(gso)) < 0) 578 return -EINVAL; 579 580 if (skb_is_gso(skb)) { 581 struct skb_shared_info *sinfo = skb_shinfo(skb); 582 583 /* This is a hint as to how much should be linear. */ 584 gso.hdr_len = skb_headlen(skb); 585 gso.gso_size = sinfo->gso_size; 586 if (sinfo->gso_type & SKB_GSO_TCPV4) 587 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 588 else if (sinfo->gso_type & SKB_GSO_TCPV6) 589 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 590 else 591 BUG(); 592 if (sinfo->gso_type & SKB_GSO_TCP_ECN) 593 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 594 } else 595 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE; 596 597 if (skb->ip_summed == CHECKSUM_PARTIAL) { 598 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 599 gso.csum_start = skb->csum_start - skb_headroom(skb); 600 gso.csum_offset = skb->csum_offset; 601 } /* else everything is zero */ 602 603 if (unlikely(memcpy_toiovec(iv, (void *)&gso, sizeof(gso)))) 604 return -EFAULT; 605 total += sizeof(gso); 606 } 607 608 len = min_t(int, skb->len, len); 609 610 skb_copy_datagram_iovec(skb, 0, iv, len); 611 total += len; 612 613 tun->dev->stats.tx_packets++; 614 tun->dev->stats.tx_bytes += len; 615 616 return total; 617 } 618 619 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv, 620 unsigned long count, loff_t pos) 621 { 622 struct file *file = iocb->ki_filp; 623 struct tun_struct *tun = file->private_data; 624 DECLARE_WAITQUEUE(wait, current); 625 struct sk_buff *skb; 626 ssize_t len, ret = 0; 627 628 if (!tun) 629 return -EBADFD; 630 631 DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name); 632 633 len = iov_length(iv, count); 634 if (len < 0) 635 return -EINVAL; 636 637 add_wait_queue(&tun->read_wait, &wait); 638 while (len) { 639 current->state = TASK_INTERRUPTIBLE; 640 641 /* Read frames from the queue */ 642 if (!(skb=skb_dequeue(&tun->readq))) { 643 if (file->f_flags & O_NONBLOCK) { 644 ret = -EAGAIN; 645 break; 646 } 647 if (signal_pending(current)) { 648 ret = -ERESTARTSYS; 649 break; 650 } 651 652 /* Nothing to read, let's sleep */ 653 schedule(); 654 continue; 655 } 656 netif_wake_queue(tun->dev); 657 658 ret = tun_put_user(tun, skb, (struct iovec *) iv, len); 659 kfree_skb(skb); 660 break; 661 } 662 663 current->state = TASK_RUNNING; 664 remove_wait_queue(&tun->read_wait, &wait); 665 666 return ret; 667 } 668 669 static void tun_setup(struct net_device *dev) 670 { 671 struct tun_struct *tun = netdev_priv(dev); 672 673 skb_queue_head_init(&tun->readq); 674 init_waitqueue_head(&tun->read_wait); 675 676 tun->owner = -1; 677 tun->group = -1; 678 679 dev->open = tun_net_open; 680 dev->hard_start_xmit = tun_net_xmit; 681 dev->stop = tun_net_close; 682 dev->ethtool_ops = &tun_ethtool_ops; 683 dev->destructor = free_netdev; 684 dev->features |= NETIF_F_NETNS_LOCAL; 685 } 686 687 static struct tun_struct *tun_get_by_name(struct tun_net *tn, const char *name) 688 { 689 struct tun_struct *tun; 690 691 ASSERT_RTNL(); 692 list_for_each_entry(tun, &tn->dev_list, list) { 693 if (!strncmp(tun->dev->name, name, IFNAMSIZ)) 694 return tun; 695 } 696 697 return NULL; 698 } 699 700 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) 701 { 702 struct tun_net *tn; 703 struct tun_struct *tun; 704 struct net_device *dev; 705 int err; 706 707 tn = net_generic(net, tun_net_id); 708 tun = tun_get_by_name(tn, ifr->ifr_name); 709 if (tun) { 710 if (tun->attached) 711 return -EBUSY; 712 713 /* Check permissions */ 714 if (((tun->owner != -1 && 715 current->euid != tun->owner) || 716 (tun->group != -1 && 717 current->egid != tun->group)) && 718 !capable(CAP_NET_ADMIN)) 719 return -EPERM; 720 } 721 else if (__dev_get_by_name(net, ifr->ifr_name)) 722 return -EINVAL; 723 else { 724 char *name; 725 unsigned long flags = 0; 726 727 err = -EINVAL; 728 729 if (!capable(CAP_NET_ADMIN)) 730 return -EPERM; 731 732 /* Set dev type */ 733 if (ifr->ifr_flags & IFF_TUN) { 734 /* TUN device */ 735 flags |= TUN_TUN_DEV; 736 name = "tun%d"; 737 } else if (ifr->ifr_flags & IFF_TAP) { 738 /* TAP device */ 739 flags |= TUN_TAP_DEV; 740 name = "tap%d"; 741 } else 742 goto failed; 743 744 if (*ifr->ifr_name) 745 name = ifr->ifr_name; 746 747 dev = alloc_netdev(sizeof(struct tun_struct), name, 748 tun_setup); 749 if (!dev) 750 return -ENOMEM; 751 752 dev_net_set(dev, net); 753 tun = netdev_priv(dev); 754 tun->dev = dev; 755 tun->flags = flags; 756 tun->txflt.count = 0; 757 758 tun_net_init(dev); 759 760 if (strchr(dev->name, '%')) { 761 err = dev_alloc_name(dev, dev->name); 762 if (err < 0) 763 goto err_free_dev; 764 } 765 766 err = register_netdevice(tun->dev); 767 if (err < 0) 768 goto err_free_dev; 769 770 list_add(&tun->list, &tn->dev_list); 771 } 772 773 DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name); 774 775 if (ifr->ifr_flags & IFF_NO_PI) 776 tun->flags |= TUN_NO_PI; 777 else 778 tun->flags &= ~TUN_NO_PI; 779 780 if (ifr->ifr_flags & IFF_ONE_QUEUE) 781 tun->flags |= TUN_ONE_QUEUE; 782 else 783 tun->flags &= ~TUN_ONE_QUEUE; 784 785 if (ifr->ifr_flags & IFF_VNET_HDR) 786 tun->flags |= TUN_VNET_HDR; 787 else 788 tun->flags &= ~TUN_VNET_HDR; 789 790 file->private_data = tun; 791 tun->attached = 1; 792 get_net(dev_net(tun->dev)); 793 794 /* Make sure persistent devices do not get stuck in 795 * xoff state. 796 */ 797 if (netif_running(tun->dev)) 798 netif_wake_queue(tun->dev); 799 800 strcpy(ifr->ifr_name, tun->dev->name); 801 return 0; 802 803 err_free_dev: 804 free_netdev(dev); 805 failed: 806 return err; 807 } 808 809 static int tun_get_iff(struct net *net, struct file *file, struct ifreq *ifr) 810 { 811 struct tun_struct *tun = file->private_data; 812 813 if (!tun) 814 return -EBADFD; 815 816 DBG(KERN_INFO "%s: tun_get_iff\n", tun->dev->name); 817 818 strcpy(ifr->ifr_name, tun->dev->name); 819 820 ifr->ifr_flags = 0; 821 822 if (ifr->ifr_flags & TUN_TUN_DEV) 823 ifr->ifr_flags |= IFF_TUN; 824 else 825 ifr->ifr_flags |= IFF_TAP; 826 827 if (tun->flags & TUN_NO_PI) 828 ifr->ifr_flags |= IFF_NO_PI; 829 830 if (tun->flags & TUN_ONE_QUEUE) 831 ifr->ifr_flags |= IFF_ONE_QUEUE; 832 833 if (tun->flags & TUN_VNET_HDR) 834 ifr->ifr_flags |= IFF_VNET_HDR; 835 836 return 0; 837 } 838 839 /* This is like a cut-down ethtool ops, except done via tun fd so no 840 * privs required. */ 841 static int set_offload(struct net_device *dev, unsigned long arg) 842 { 843 unsigned int old_features, features; 844 845 old_features = dev->features; 846 /* Unset features, set them as we chew on the arg. */ 847 features = (old_features & ~(NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST 848 |NETIF_F_TSO_ECN|NETIF_F_TSO|NETIF_F_TSO6)); 849 850 if (arg & TUN_F_CSUM) { 851 features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; 852 arg &= ~TUN_F_CSUM; 853 854 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) { 855 if (arg & TUN_F_TSO_ECN) { 856 features |= NETIF_F_TSO_ECN; 857 arg &= ~TUN_F_TSO_ECN; 858 } 859 if (arg & TUN_F_TSO4) 860 features |= NETIF_F_TSO; 861 if (arg & TUN_F_TSO6) 862 features |= NETIF_F_TSO6; 863 arg &= ~(TUN_F_TSO4|TUN_F_TSO6); 864 } 865 } 866 867 /* This gives the user a way to test for new features in future by 868 * trying to set them. */ 869 if (arg) 870 return -EINVAL; 871 872 dev->features = features; 873 if (old_features != dev->features) 874 netdev_features_change(dev); 875 876 return 0; 877 } 878 879 static int tun_chr_ioctl(struct inode *inode, struct file *file, 880 unsigned int cmd, unsigned long arg) 881 { 882 struct tun_struct *tun = file->private_data; 883 void __user* argp = (void __user*)arg; 884 struct ifreq ifr; 885 int ret; 886 DECLARE_MAC_BUF(mac); 887 888 if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89) 889 if (copy_from_user(&ifr, argp, sizeof ifr)) 890 return -EFAULT; 891 892 if (cmd == TUNSETIFF && !tun) { 893 int err; 894 895 ifr.ifr_name[IFNAMSIZ-1] = '\0'; 896 897 rtnl_lock(); 898 err = tun_set_iff(current->nsproxy->net_ns, file, &ifr); 899 rtnl_unlock(); 900 901 if (err) 902 return err; 903 904 if (copy_to_user(argp, &ifr, sizeof(ifr))) 905 return -EFAULT; 906 return 0; 907 } 908 909 if (cmd == TUNGETFEATURES) { 910 /* Currently this just means: "what IFF flags are valid?". 911 * This is needed because we never checked for invalid flags on 912 * TUNSETIFF. */ 913 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE | 914 IFF_VNET_HDR, 915 (unsigned int __user*)argp); 916 } 917 918 if (!tun) 919 return -EBADFD; 920 921 DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd); 922 923 switch (cmd) { 924 case TUNGETIFF: 925 ret = tun_get_iff(current->nsproxy->net_ns, file, &ifr); 926 if (ret) 927 return ret; 928 929 if (copy_to_user(argp, &ifr, sizeof(ifr))) 930 return -EFAULT; 931 break; 932 933 case TUNSETNOCSUM: 934 /* Disable/Enable checksum */ 935 if (arg) 936 tun->flags |= TUN_NOCHECKSUM; 937 else 938 tun->flags &= ~TUN_NOCHECKSUM; 939 940 DBG(KERN_INFO "%s: checksum %s\n", 941 tun->dev->name, arg ? "disabled" : "enabled"); 942 break; 943 944 case TUNSETPERSIST: 945 /* Disable/Enable persist mode */ 946 if (arg) 947 tun->flags |= TUN_PERSIST; 948 else 949 tun->flags &= ~TUN_PERSIST; 950 951 DBG(KERN_INFO "%s: persist %s\n", 952 tun->dev->name, arg ? "enabled" : "disabled"); 953 break; 954 955 case TUNSETOWNER: 956 /* Set owner of the device */ 957 tun->owner = (uid_t) arg; 958 959 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner); 960 break; 961 962 case TUNSETGROUP: 963 /* Set group of the device */ 964 tun->group= (gid_t) arg; 965 966 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group); 967 break; 968 969 case TUNSETLINK: 970 /* Only allow setting the type when the interface is down */ 971 rtnl_lock(); 972 if (tun->dev->flags & IFF_UP) { 973 DBG(KERN_INFO "%s: Linktype set failed because interface is up\n", 974 tun->dev->name); 975 ret = -EBUSY; 976 } else { 977 tun->dev->type = (int) arg; 978 DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type); 979 ret = 0; 980 } 981 rtnl_unlock(); 982 return ret; 983 984 #ifdef TUN_DEBUG 985 case TUNSETDEBUG: 986 tun->debug = arg; 987 break; 988 #endif 989 case TUNSETOFFLOAD: 990 rtnl_lock(); 991 ret = set_offload(tun->dev, arg); 992 rtnl_unlock(); 993 return ret; 994 995 case TUNSETTXFILTER: 996 /* Can be set only for TAPs */ 997 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV) 998 return -EINVAL; 999 rtnl_lock(); 1000 ret = update_filter(&tun->txflt, (void __user *)arg); 1001 rtnl_unlock(); 1002 return ret; 1003 1004 case SIOCGIFHWADDR: 1005 /* Get hw addres */ 1006 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN); 1007 ifr.ifr_hwaddr.sa_family = tun->dev->type; 1008 if (copy_to_user(argp, &ifr, sizeof ifr)) 1009 return -EFAULT; 1010 return 0; 1011 1012 case SIOCSIFHWADDR: 1013 /* Set hw address */ 1014 DBG(KERN_DEBUG "%s: set hw address: %s\n", 1015 tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data)); 1016 1017 rtnl_lock(); 1018 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr); 1019 rtnl_unlock(); 1020 return ret; 1021 1022 default: 1023 return -EINVAL; 1024 }; 1025 1026 return 0; 1027 } 1028 1029 static int tun_chr_fasync(int fd, struct file *file, int on) 1030 { 1031 struct tun_struct *tun = file->private_data; 1032 int ret; 1033 1034 if (!tun) 1035 return -EBADFD; 1036 1037 DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on); 1038 1039 lock_kernel(); 1040 if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0) 1041 goto out; 1042 1043 if (on) { 1044 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0); 1045 if (ret) 1046 goto out; 1047 tun->flags |= TUN_FASYNC; 1048 } else 1049 tun->flags &= ~TUN_FASYNC; 1050 ret = 0; 1051 out: 1052 unlock_kernel(); 1053 return ret; 1054 } 1055 1056 static int tun_chr_open(struct inode *inode, struct file * file) 1057 { 1058 cycle_kernel_lock(); 1059 DBG1(KERN_INFO "tunX: tun_chr_open\n"); 1060 file->private_data = NULL; 1061 return 0; 1062 } 1063 1064 static int tun_chr_close(struct inode *inode, struct file *file) 1065 { 1066 struct tun_struct *tun = file->private_data; 1067 1068 if (!tun) 1069 return 0; 1070 1071 DBG(KERN_INFO "%s: tun_chr_close\n", tun->dev->name); 1072 1073 rtnl_lock(); 1074 1075 /* Detach from net device */ 1076 file->private_data = NULL; 1077 tun->attached = 0; 1078 put_net(dev_net(tun->dev)); 1079 1080 /* Drop read queue */ 1081 skb_queue_purge(&tun->readq); 1082 1083 if (!(tun->flags & TUN_PERSIST)) { 1084 list_del(&tun->list); 1085 unregister_netdevice(tun->dev); 1086 } 1087 1088 rtnl_unlock(); 1089 1090 return 0; 1091 } 1092 1093 static const struct file_operations tun_fops = { 1094 .owner = THIS_MODULE, 1095 .llseek = no_llseek, 1096 .read = do_sync_read, 1097 .aio_read = tun_chr_aio_read, 1098 .write = do_sync_write, 1099 .aio_write = tun_chr_aio_write, 1100 .poll = tun_chr_poll, 1101 .ioctl = tun_chr_ioctl, 1102 .open = tun_chr_open, 1103 .release = tun_chr_close, 1104 .fasync = tun_chr_fasync 1105 }; 1106 1107 static struct miscdevice tun_miscdev = { 1108 .minor = TUN_MINOR, 1109 .name = "tun", 1110 .fops = &tun_fops, 1111 }; 1112 1113 /* ethtool interface */ 1114 1115 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd) 1116 { 1117 cmd->supported = 0; 1118 cmd->advertising = 0; 1119 cmd->speed = SPEED_10; 1120 cmd->duplex = DUPLEX_FULL; 1121 cmd->port = PORT_TP; 1122 cmd->phy_address = 0; 1123 cmd->transceiver = XCVR_INTERNAL; 1124 cmd->autoneg = AUTONEG_DISABLE; 1125 cmd->maxtxpkt = 0; 1126 cmd->maxrxpkt = 0; 1127 return 0; 1128 } 1129 1130 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info) 1131 { 1132 struct tun_struct *tun = netdev_priv(dev); 1133 1134 strcpy(info->driver, DRV_NAME); 1135 strcpy(info->version, DRV_VERSION); 1136 strcpy(info->fw_version, "N/A"); 1137 1138 switch (tun->flags & TUN_TYPE_MASK) { 1139 case TUN_TUN_DEV: 1140 strcpy(info->bus_info, "tun"); 1141 break; 1142 case TUN_TAP_DEV: 1143 strcpy(info->bus_info, "tap"); 1144 break; 1145 } 1146 } 1147 1148 static u32 tun_get_msglevel(struct net_device *dev) 1149 { 1150 #ifdef TUN_DEBUG 1151 struct tun_struct *tun = netdev_priv(dev); 1152 return tun->debug; 1153 #else 1154 return -EOPNOTSUPP; 1155 #endif 1156 } 1157 1158 static void tun_set_msglevel(struct net_device *dev, u32 value) 1159 { 1160 #ifdef TUN_DEBUG 1161 struct tun_struct *tun = netdev_priv(dev); 1162 tun->debug = value; 1163 #endif 1164 } 1165 1166 static u32 tun_get_link(struct net_device *dev) 1167 { 1168 struct tun_struct *tun = netdev_priv(dev); 1169 return tun->attached; 1170 } 1171 1172 static u32 tun_get_rx_csum(struct net_device *dev) 1173 { 1174 struct tun_struct *tun = netdev_priv(dev); 1175 return (tun->flags & TUN_NOCHECKSUM) == 0; 1176 } 1177 1178 static int tun_set_rx_csum(struct net_device *dev, u32 data) 1179 { 1180 struct tun_struct *tun = netdev_priv(dev); 1181 if (data) 1182 tun->flags &= ~TUN_NOCHECKSUM; 1183 else 1184 tun->flags |= TUN_NOCHECKSUM; 1185 return 0; 1186 } 1187 1188 static const struct ethtool_ops tun_ethtool_ops = { 1189 .get_settings = tun_get_settings, 1190 .get_drvinfo = tun_get_drvinfo, 1191 .get_msglevel = tun_get_msglevel, 1192 .set_msglevel = tun_set_msglevel, 1193 .get_link = tun_get_link, 1194 .get_rx_csum = tun_get_rx_csum, 1195 .set_rx_csum = tun_set_rx_csum 1196 }; 1197 1198 static int tun_init_net(struct net *net) 1199 { 1200 struct tun_net *tn; 1201 1202 tn = kmalloc(sizeof(*tn), GFP_KERNEL); 1203 if (tn == NULL) 1204 return -ENOMEM; 1205 1206 INIT_LIST_HEAD(&tn->dev_list); 1207 1208 if (net_assign_generic(net, tun_net_id, tn)) { 1209 kfree(tn); 1210 return -ENOMEM; 1211 } 1212 1213 return 0; 1214 } 1215 1216 static void tun_exit_net(struct net *net) 1217 { 1218 struct tun_net *tn; 1219 struct tun_struct *tun, *nxt; 1220 1221 tn = net_generic(net, tun_net_id); 1222 1223 rtnl_lock(); 1224 list_for_each_entry_safe(tun, nxt, &tn->dev_list, list) { 1225 DBG(KERN_INFO "%s cleaned up\n", tun->dev->name); 1226 unregister_netdevice(tun->dev); 1227 } 1228 rtnl_unlock(); 1229 1230 kfree(tn); 1231 } 1232 1233 static struct pernet_operations tun_net_ops = { 1234 .init = tun_init_net, 1235 .exit = tun_exit_net, 1236 }; 1237 1238 static int __init tun_init(void) 1239 { 1240 int ret = 0; 1241 1242 printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION); 1243 printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT); 1244 1245 ret = register_pernet_gen_device(&tun_net_id, &tun_net_ops); 1246 if (ret) { 1247 printk(KERN_ERR "tun: Can't register pernet ops\n"); 1248 goto err_pernet; 1249 } 1250 1251 ret = misc_register(&tun_miscdev); 1252 if (ret) { 1253 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR); 1254 goto err_misc; 1255 } 1256 return 0; 1257 1258 err_misc: 1259 unregister_pernet_gen_device(tun_net_id, &tun_net_ops); 1260 err_pernet: 1261 return ret; 1262 } 1263 1264 static void tun_cleanup(void) 1265 { 1266 misc_deregister(&tun_miscdev); 1267 unregister_pernet_gen_device(tun_net_id, &tun_net_ops); 1268 } 1269 1270 module_init(tun_init); 1271 module_exit(tun_cleanup); 1272 MODULE_DESCRIPTION(DRV_DESCRIPTION); 1273 MODULE_AUTHOR(DRV_COPYRIGHT); 1274 MODULE_LICENSE("GPL"); 1275 MODULE_ALIAS_MISCDEV(TUN_MINOR); 1276