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 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 static const struct net_device_ops tun_netdev_ops = { 309 .ndo_open = tun_net_open, 310 .ndo_stop = tun_net_close, 311 .ndo_start_xmit = tun_net_xmit, 312 .ndo_change_mtu = tun_net_change_mtu, 313 }; 314 315 static const struct net_device_ops tap_netdev_ops = { 316 .ndo_open = tun_net_open, 317 .ndo_stop = tun_net_close, 318 .ndo_start_xmit = tun_net_xmit, 319 .ndo_change_mtu = tun_net_change_mtu, 320 .ndo_set_multicast_list = tun_net_mclist, 321 .ndo_set_mac_address = eth_mac_addr, 322 .ndo_validate_addr = eth_validate_addr, 323 }; 324 325 /* Initialize net device. */ 326 static void tun_net_init(struct net_device *dev) 327 { 328 struct tun_struct *tun = netdev_priv(dev); 329 330 switch (tun->flags & TUN_TYPE_MASK) { 331 case TUN_TUN_DEV: 332 dev->netdev_ops = &tun_netdev_ops; 333 334 /* Point-to-Point TUN Device */ 335 dev->hard_header_len = 0; 336 dev->addr_len = 0; 337 dev->mtu = 1500; 338 339 /* Zero header length */ 340 dev->type = ARPHRD_NONE; 341 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 342 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */ 343 break; 344 345 case TUN_TAP_DEV: 346 dev->netdev_ops = &tap_netdev_ops; 347 /* Ethernet TAP Device */ 348 ether_setup(dev); 349 350 random_ether_addr(dev->dev_addr); 351 352 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */ 353 break; 354 } 355 } 356 357 /* Character device part */ 358 359 /* Poll */ 360 static unsigned int tun_chr_poll(struct file *file, poll_table * wait) 361 { 362 struct tun_struct *tun = file->private_data; 363 unsigned int mask = POLLOUT | POLLWRNORM; 364 365 if (!tun) 366 return -EBADFD; 367 368 DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name); 369 370 poll_wait(file, &tun->read_wait, wait); 371 372 if (!skb_queue_empty(&tun->readq)) 373 mask |= POLLIN | POLLRDNORM; 374 375 return mask; 376 } 377 378 /* prepad is the amount to reserve at front. len is length after that. 379 * linear is a hint as to how much to copy (usually headers). */ 380 static struct sk_buff *tun_alloc_skb(size_t prepad, size_t len, size_t linear, 381 gfp_t gfp) 382 { 383 struct sk_buff *skb; 384 unsigned int i; 385 386 skb = alloc_skb(prepad + len, gfp|__GFP_NOWARN); 387 if (skb) { 388 skb_reserve(skb, prepad); 389 skb_put(skb, len); 390 return skb; 391 } 392 393 /* Under a page? Don't bother with paged skb. */ 394 if (prepad + len < PAGE_SIZE) 395 return NULL; 396 397 /* Start with a normal skb, and add pages. */ 398 skb = alloc_skb(prepad + linear, gfp); 399 if (!skb) 400 return NULL; 401 402 skb_reserve(skb, prepad); 403 skb_put(skb, linear); 404 405 len -= linear; 406 407 for (i = 0; i < MAX_SKB_FRAGS; i++) { 408 skb_frag_t *f = &skb_shinfo(skb)->frags[i]; 409 410 f->page = alloc_page(gfp|__GFP_ZERO); 411 if (!f->page) 412 break; 413 414 f->page_offset = 0; 415 f->size = PAGE_SIZE; 416 417 skb->data_len += PAGE_SIZE; 418 skb->len += PAGE_SIZE; 419 skb->truesize += PAGE_SIZE; 420 skb_shinfo(skb)->nr_frags++; 421 422 if (len < PAGE_SIZE) { 423 len = 0; 424 break; 425 } 426 len -= PAGE_SIZE; 427 } 428 429 /* Too large, or alloc fail? */ 430 if (unlikely(len)) { 431 kfree_skb(skb); 432 skb = NULL; 433 } 434 435 return skb; 436 } 437 438 /* Get packet from user space buffer */ 439 static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, size_t count) 440 { 441 struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) }; 442 struct sk_buff *skb; 443 size_t len = count, align = 0; 444 struct virtio_net_hdr gso = { 0 }; 445 446 if (!(tun->flags & TUN_NO_PI)) { 447 if ((len -= sizeof(pi)) > count) 448 return -EINVAL; 449 450 if(memcpy_fromiovec((void *)&pi, iv, sizeof(pi))) 451 return -EFAULT; 452 } 453 454 if (tun->flags & TUN_VNET_HDR) { 455 if ((len -= sizeof(gso)) > count) 456 return -EINVAL; 457 458 if (memcpy_fromiovec((void *)&gso, iv, sizeof(gso))) 459 return -EFAULT; 460 461 if (gso.hdr_len > len) 462 return -EINVAL; 463 } 464 465 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) { 466 align = NET_IP_ALIGN; 467 if (unlikely(len < ETH_HLEN)) 468 return -EINVAL; 469 } 470 471 if (!(skb = tun_alloc_skb(align, len, gso.hdr_len, GFP_KERNEL))) { 472 tun->dev->stats.rx_dropped++; 473 return -ENOMEM; 474 } 475 476 if (skb_copy_datagram_from_iovec(skb, 0, iv, len)) { 477 tun->dev->stats.rx_dropped++; 478 kfree_skb(skb); 479 return -EFAULT; 480 } 481 482 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 483 if (!skb_partial_csum_set(skb, gso.csum_start, 484 gso.csum_offset)) { 485 tun->dev->stats.rx_frame_errors++; 486 kfree_skb(skb); 487 return -EINVAL; 488 } 489 } else if (tun->flags & TUN_NOCHECKSUM) 490 skb->ip_summed = CHECKSUM_UNNECESSARY; 491 492 switch (tun->flags & TUN_TYPE_MASK) { 493 case TUN_TUN_DEV: 494 if (tun->flags & TUN_NO_PI) { 495 switch (skb->data[0] & 0xf0) { 496 case 0x40: 497 pi.proto = htons(ETH_P_IP); 498 break; 499 case 0x60: 500 pi.proto = htons(ETH_P_IPV6); 501 break; 502 default: 503 tun->dev->stats.rx_dropped++; 504 kfree_skb(skb); 505 return -EINVAL; 506 } 507 } 508 509 skb_reset_mac_header(skb); 510 skb->protocol = pi.proto; 511 skb->dev = tun->dev; 512 break; 513 case TUN_TAP_DEV: 514 skb->protocol = eth_type_trans(skb, tun->dev); 515 break; 516 }; 517 518 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 519 pr_debug("GSO!\n"); 520 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 521 case VIRTIO_NET_HDR_GSO_TCPV4: 522 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; 523 break; 524 case VIRTIO_NET_HDR_GSO_TCPV6: 525 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; 526 break; 527 default: 528 tun->dev->stats.rx_frame_errors++; 529 kfree_skb(skb); 530 return -EINVAL; 531 } 532 533 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN) 534 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; 535 536 skb_shinfo(skb)->gso_size = gso.gso_size; 537 if (skb_shinfo(skb)->gso_size == 0) { 538 tun->dev->stats.rx_frame_errors++; 539 kfree_skb(skb); 540 return -EINVAL; 541 } 542 543 /* Header must be checked, and gso_segs computed. */ 544 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 545 skb_shinfo(skb)->gso_segs = 0; 546 } 547 548 netif_rx_ni(skb); 549 550 tun->dev->stats.rx_packets++; 551 tun->dev->stats.rx_bytes += len; 552 553 return count; 554 } 555 556 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv, 557 unsigned long count, loff_t pos) 558 { 559 struct tun_struct *tun = iocb->ki_filp->private_data; 560 561 if (!tun) 562 return -EBADFD; 563 564 DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count); 565 566 return tun_get_user(tun, (struct iovec *) iv, iov_length(iv, count)); 567 } 568 569 /* Put packet to the user space buffer */ 570 static __inline__ ssize_t tun_put_user(struct tun_struct *tun, 571 struct sk_buff *skb, 572 struct iovec *iv, int len) 573 { 574 struct tun_pi pi = { 0, skb->protocol }; 575 ssize_t total = 0; 576 577 if (!(tun->flags & TUN_NO_PI)) { 578 if ((len -= sizeof(pi)) < 0) 579 return -EINVAL; 580 581 if (len < skb->len) { 582 /* Packet will be striped */ 583 pi.flags |= TUN_PKT_STRIP; 584 } 585 586 if (memcpy_toiovec(iv, (void *) &pi, sizeof(pi))) 587 return -EFAULT; 588 total += sizeof(pi); 589 } 590 591 if (tun->flags & TUN_VNET_HDR) { 592 struct virtio_net_hdr gso = { 0 }; /* no info leak */ 593 if ((len -= sizeof(gso)) < 0) 594 return -EINVAL; 595 596 if (skb_is_gso(skb)) { 597 struct skb_shared_info *sinfo = skb_shinfo(skb); 598 599 /* This is a hint as to how much should be linear. */ 600 gso.hdr_len = skb_headlen(skb); 601 gso.gso_size = sinfo->gso_size; 602 if (sinfo->gso_type & SKB_GSO_TCPV4) 603 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 604 else if (sinfo->gso_type & SKB_GSO_TCPV6) 605 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 606 else 607 BUG(); 608 if (sinfo->gso_type & SKB_GSO_TCP_ECN) 609 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 610 } else 611 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE; 612 613 if (skb->ip_summed == CHECKSUM_PARTIAL) { 614 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 615 gso.csum_start = skb->csum_start - skb_headroom(skb); 616 gso.csum_offset = skb->csum_offset; 617 } /* else everything is zero */ 618 619 if (unlikely(memcpy_toiovec(iv, (void *)&gso, sizeof(gso)))) 620 return -EFAULT; 621 total += sizeof(gso); 622 } 623 624 len = min_t(int, skb->len, len); 625 626 skb_copy_datagram_iovec(skb, 0, iv, len); 627 total += len; 628 629 tun->dev->stats.tx_packets++; 630 tun->dev->stats.tx_bytes += len; 631 632 return total; 633 } 634 635 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv, 636 unsigned long count, loff_t pos) 637 { 638 struct file *file = iocb->ki_filp; 639 struct tun_struct *tun = file->private_data; 640 DECLARE_WAITQUEUE(wait, current); 641 struct sk_buff *skb; 642 ssize_t len, ret = 0; 643 644 if (!tun) 645 return -EBADFD; 646 647 DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name); 648 649 len = iov_length(iv, count); 650 if (len < 0) 651 return -EINVAL; 652 653 add_wait_queue(&tun->read_wait, &wait); 654 while (len) { 655 current->state = TASK_INTERRUPTIBLE; 656 657 /* Read frames from the queue */ 658 if (!(skb=skb_dequeue(&tun->readq))) { 659 if (file->f_flags & O_NONBLOCK) { 660 ret = -EAGAIN; 661 break; 662 } 663 if (signal_pending(current)) { 664 ret = -ERESTARTSYS; 665 break; 666 } 667 668 /* Nothing to read, let's sleep */ 669 schedule(); 670 continue; 671 } 672 netif_wake_queue(tun->dev); 673 674 ret = tun_put_user(tun, skb, (struct iovec *) iv, len); 675 kfree_skb(skb); 676 break; 677 } 678 679 current->state = TASK_RUNNING; 680 remove_wait_queue(&tun->read_wait, &wait); 681 682 return ret; 683 } 684 685 static void tun_setup(struct net_device *dev) 686 { 687 struct tun_struct *tun = netdev_priv(dev); 688 689 skb_queue_head_init(&tun->readq); 690 init_waitqueue_head(&tun->read_wait); 691 692 tun->owner = -1; 693 tun->group = -1; 694 695 dev->ethtool_ops = &tun_ethtool_ops; 696 dev->destructor = free_netdev; 697 dev->features |= NETIF_F_NETNS_LOCAL; 698 } 699 700 static struct tun_struct *tun_get_by_name(struct tun_net *tn, const char *name) 701 { 702 struct tun_struct *tun; 703 704 ASSERT_RTNL(); 705 list_for_each_entry(tun, &tn->dev_list, list) { 706 if (!strncmp(tun->dev->name, name, IFNAMSIZ)) 707 return tun; 708 } 709 710 return NULL; 711 } 712 713 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) 714 { 715 struct tun_net *tn; 716 struct tun_struct *tun; 717 struct net_device *dev; 718 const struct cred *cred = current_cred(); 719 int err; 720 721 tn = net_generic(net, tun_net_id); 722 tun = tun_get_by_name(tn, ifr->ifr_name); 723 if (tun) { 724 if (tun->attached) 725 return -EBUSY; 726 727 /* Check permissions */ 728 if (((tun->owner != -1 && 729 cred->euid != tun->owner) || 730 (tun->group != -1 && 731 cred->egid != tun->group)) && 732 !capable(CAP_NET_ADMIN)) { 733 return -EPERM; 734 } 735 } 736 else if (__dev_get_by_name(net, ifr->ifr_name)) 737 return -EINVAL; 738 else { 739 char *name; 740 unsigned long flags = 0; 741 742 err = -EINVAL; 743 744 if (!capable(CAP_NET_ADMIN)) 745 return -EPERM; 746 747 /* Set dev type */ 748 if (ifr->ifr_flags & IFF_TUN) { 749 /* TUN device */ 750 flags |= TUN_TUN_DEV; 751 name = "tun%d"; 752 } else if (ifr->ifr_flags & IFF_TAP) { 753 /* TAP device */ 754 flags |= TUN_TAP_DEV; 755 name = "tap%d"; 756 } else 757 goto failed; 758 759 if (*ifr->ifr_name) 760 name = ifr->ifr_name; 761 762 dev = alloc_netdev(sizeof(struct tun_struct), name, 763 tun_setup); 764 if (!dev) 765 return -ENOMEM; 766 767 dev_net_set(dev, net); 768 769 tun = netdev_priv(dev); 770 tun->dev = dev; 771 tun->flags = flags; 772 tun->txflt.count = 0; 773 774 tun_net_init(dev); 775 776 if (strchr(dev->name, '%')) { 777 err = dev_alloc_name(dev, dev->name); 778 if (err < 0) 779 goto err_free_dev; 780 } 781 782 err = register_netdevice(tun->dev); 783 if (err < 0) 784 goto err_free_dev; 785 786 list_add(&tun->list, &tn->dev_list); 787 } 788 789 DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name); 790 791 if (ifr->ifr_flags & IFF_NO_PI) 792 tun->flags |= TUN_NO_PI; 793 else 794 tun->flags &= ~TUN_NO_PI; 795 796 if (ifr->ifr_flags & IFF_ONE_QUEUE) 797 tun->flags |= TUN_ONE_QUEUE; 798 else 799 tun->flags &= ~TUN_ONE_QUEUE; 800 801 if (ifr->ifr_flags & IFF_VNET_HDR) 802 tun->flags |= TUN_VNET_HDR; 803 else 804 tun->flags &= ~TUN_VNET_HDR; 805 806 file->private_data = tun; 807 tun->attached = 1; 808 get_net(dev_net(tun->dev)); 809 810 /* Make sure persistent devices do not get stuck in 811 * xoff state. 812 */ 813 if (netif_running(tun->dev)) 814 netif_wake_queue(tun->dev); 815 816 strcpy(ifr->ifr_name, tun->dev->name); 817 return 0; 818 819 err_free_dev: 820 free_netdev(dev); 821 failed: 822 return err; 823 } 824 825 static int tun_get_iff(struct net *net, struct file *file, struct ifreq *ifr) 826 { 827 struct tun_struct *tun = file->private_data; 828 829 if (!tun) 830 return -EBADFD; 831 832 DBG(KERN_INFO "%s: tun_get_iff\n", tun->dev->name); 833 834 strcpy(ifr->ifr_name, tun->dev->name); 835 836 ifr->ifr_flags = 0; 837 838 if (ifr->ifr_flags & TUN_TUN_DEV) 839 ifr->ifr_flags |= IFF_TUN; 840 else 841 ifr->ifr_flags |= IFF_TAP; 842 843 if (tun->flags & TUN_NO_PI) 844 ifr->ifr_flags |= IFF_NO_PI; 845 846 if (tun->flags & TUN_ONE_QUEUE) 847 ifr->ifr_flags |= IFF_ONE_QUEUE; 848 849 if (tun->flags & TUN_VNET_HDR) 850 ifr->ifr_flags |= IFF_VNET_HDR; 851 852 return 0; 853 } 854 855 /* This is like a cut-down ethtool ops, except done via tun fd so no 856 * privs required. */ 857 static int set_offload(struct net_device *dev, unsigned long arg) 858 { 859 unsigned int old_features, features; 860 861 old_features = dev->features; 862 /* Unset features, set them as we chew on the arg. */ 863 features = (old_features & ~(NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST 864 |NETIF_F_TSO_ECN|NETIF_F_TSO|NETIF_F_TSO6)); 865 866 if (arg & TUN_F_CSUM) { 867 features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; 868 arg &= ~TUN_F_CSUM; 869 870 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) { 871 if (arg & TUN_F_TSO_ECN) { 872 features |= NETIF_F_TSO_ECN; 873 arg &= ~TUN_F_TSO_ECN; 874 } 875 if (arg & TUN_F_TSO4) 876 features |= NETIF_F_TSO; 877 if (arg & TUN_F_TSO6) 878 features |= NETIF_F_TSO6; 879 arg &= ~(TUN_F_TSO4|TUN_F_TSO6); 880 } 881 } 882 883 /* This gives the user a way to test for new features in future by 884 * trying to set them. */ 885 if (arg) 886 return -EINVAL; 887 888 dev->features = features; 889 if (old_features != dev->features) 890 netdev_features_change(dev); 891 892 return 0; 893 } 894 895 static int tun_chr_ioctl(struct inode *inode, struct file *file, 896 unsigned int cmd, unsigned long arg) 897 { 898 struct tun_struct *tun = file->private_data; 899 void __user* argp = (void __user*)arg; 900 struct ifreq ifr; 901 int ret; 902 903 if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89) 904 if (copy_from_user(&ifr, argp, sizeof ifr)) 905 return -EFAULT; 906 907 if (cmd == TUNSETIFF && !tun) { 908 int err; 909 910 ifr.ifr_name[IFNAMSIZ-1] = '\0'; 911 912 rtnl_lock(); 913 err = tun_set_iff(current->nsproxy->net_ns, file, &ifr); 914 rtnl_unlock(); 915 916 if (err) 917 return err; 918 919 if (copy_to_user(argp, &ifr, sizeof(ifr))) 920 return -EFAULT; 921 return 0; 922 } 923 924 if (cmd == TUNGETFEATURES) { 925 /* Currently this just means: "what IFF flags are valid?". 926 * This is needed because we never checked for invalid flags on 927 * TUNSETIFF. */ 928 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE | 929 IFF_VNET_HDR, 930 (unsigned int __user*)argp); 931 } 932 933 if (!tun) 934 return -EBADFD; 935 936 DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd); 937 938 switch (cmd) { 939 case TUNGETIFF: 940 ret = tun_get_iff(current->nsproxy->net_ns, file, &ifr); 941 if (ret) 942 return ret; 943 944 if (copy_to_user(argp, &ifr, sizeof(ifr))) 945 return -EFAULT; 946 break; 947 948 case TUNSETNOCSUM: 949 /* Disable/Enable checksum */ 950 if (arg) 951 tun->flags |= TUN_NOCHECKSUM; 952 else 953 tun->flags &= ~TUN_NOCHECKSUM; 954 955 DBG(KERN_INFO "%s: checksum %s\n", 956 tun->dev->name, arg ? "disabled" : "enabled"); 957 break; 958 959 case TUNSETPERSIST: 960 /* Disable/Enable persist mode */ 961 if (arg) 962 tun->flags |= TUN_PERSIST; 963 else 964 tun->flags &= ~TUN_PERSIST; 965 966 DBG(KERN_INFO "%s: persist %s\n", 967 tun->dev->name, arg ? "enabled" : "disabled"); 968 break; 969 970 case TUNSETOWNER: 971 /* Set owner of the device */ 972 tun->owner = (uid_t) arg; 973 974 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner); 975 break; 976 977 case TUNSETGROUP: 978 /* Set group of the device */ 979 tun->group= (gid_t) arg; 980 981 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group); 982 break; 983 984 case TUNSETLINK: 985 /* Only allow setting the type when the interface is down */ 986 rtnl_lock(); 987 if (tun->dev->flags & IFF_UP) { 988 DBG(KERN_INFO "%s: Linktype set failed because interface is up\n", 989 tun->dev->name); 990 ret = -EBUSY; 991 } else { 992 tun->dev->type = (int) arg; 993 DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type); 994 ret = 0; 995 } 996 rtnl_unlock(); 997 return ret; 998 999 #ifdef TUN_DEBUG 1000 case TUNSETDEBUG: 1001 tun->debug = arg; 1002 break; 1003 #endif 1004 case TUNSETOFFLOAD: 1005 rtnl_lock(); 1006 ret = set_offload(tun->dev, arg); 1007 rtnl_unlock(); 1008 return ret; 1009 1010 case TUNSETTXFILTER: 1011 /* Can be set only for TAPs */ 1012 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV) 1013 return -EINVAL; 1014 rtnl_lock(); 1015 ret = update_filter(&tun->txflt, (void __user *)arg); 1016 rtnl_unlock(); 1017 return ret; 1018 1019 case SIOCGIFHWADDR: 1020 /* Get hw addres */ 1021 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN); 1022 ifr.ifr_hwaddr.sa_family = tun->dev->type; 1023 if (copy_to_user(argp, &ifr, sizeof ifr)) 1024 return -EFAULT; 1025 return 0; 1026 1027 case SIOCSIFHWADDR: 1028 /* Set hw address */ 1029 DBG(KERN_DEBUG "%s: set hw address: %pM\n", 1030 tun->dev->name, ifr.ifr_hwaddr.sa_data); 1031 1032 rtnl_lock(); 1033 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr); 1034 rtnl_unlock(); 1035 return ret; 1036 1037 default: 1038 return -EINVAL; 1039 }; 1040 1041 return 0; 1042 } 1043 1044 static int tun_chr_fasync(int fd, struct file *file, int on) 1045 { 1046 struct tun_struct *tun = file->private_data; 1047 int ret; 1048 1049 if (!tun) 1050 return -EBADFD; 1051 1052 DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on); 1053 1054 lock_kernel(); 1055 if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0) 1056 goto out; 1057 1058 if (on) { 1059 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0); 1060 if (ret) 1061 goto out; 1062 tun->flags |= TUN_FASYNC; 1063 } else 1064 tun->flags &= ~TUN_FASYNC; 1065 ret = 0; 1066 out: 1067 unlock_kernel(); 1068 return ret; 1069 } 1070 1071 static int tun_chr_open(struct inode *inode, struct file * file) 1072 { 1073 cycle_kernel_lock(); 1074 DBG1(KERN_INFO "tunX: tun_chr_open\n"); 1075 file->private_data = NULL; 1076 return 0; 1077 } 1078 1079 static int tun_chr_close(struct inode *inode, struct file *file) 1080 { 1081 struct tun_struct *tun = file->private_data; 1082 1083 if (!tun) 1084 return 0; 1085 1086 DBG(KERN_INFO "%s: tun_chr_close\n", tun->dev->name); 1087 1088 rtnl_lock(); 1089 1090 /* Detach from net device */ 1091 file->private_data = NULL; 1092 tun->attached = 0; 1093 put_net(dev_net(tun->dev)); 1094 1095 /* Drop read queue */ 1096 skb_queue_purge(&tun->readq); 1097 1098 if (!(tun->flags & TUN_PERSIST)) { 1099 list_del(&tun->list); 1100 unregister_netdevice(tun->dev); 1101 } 1102 1103 rtnl_unlock(); 1104 1105 return 0; 1106 } 1107 1108 static const struct file_operations tun_fops = { 1109 .owner = THIS_MODULE, 1110 .llseek = no_llseek, 1111 .read = do_sync_read, 1112 .aio_read = tun_chr_aio_read, 1113 .write = do_sync_write, 1114 .aio_write = tun_chr_aio_write, 1115 .poll = tun_chr_poll, 1116 .ioctl = tun_chr_ioctl, 1117 .open = tun_chr_open, 1118 .release = tun_chr_close, 1119 .fasync = tun_chr_fasync 1120 }; 1121 1122 static struct miscdevice tun_miscdev = { 1123 .minor = TUN_MINOR, 1124 .name = "tun", 1125 .fops = &tun_fops, 1126 }; 1127 1128 /* ethtool interface */ 1129 1130 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd) 1131 { 1132 cmd->supported = 0; 1133 cmd->advertising = 0; 1134 cmd->speed = SPEED_10; 1135 cmd->duplex = DUPLEX_FULL; 1136 cmd->port = PORT_TP; 1137 cmd->phy_address = 0; 1138 cmd->transceiver = XCVR_INTERNAL; 1139 cmd->autoneg = AUTONEG_DISABLE; 1140 cmd->maxtxpkt = 0; 1141 cmd->maxrxpkt = 0; 1142 return 0; 1143 } 1144 1145 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info) 1146 { 1147 struct tun_struct *tun = netdev_priv(dev); 1148 1149 strcpy(info->driver, DRV_NAME); 1150 strcpy(info->version, DRV_VERSION); 1151 strcpy(info->fw_version, "N/A"); 1152 1153 switch (tun->flags & TUN_TYPE_MASK) { 1154 case TUN_TUN_DEV: 1155 strcpy(info->bus_info, "tun"); 1156 break; 1157 case TUN_TAP_DEV: 1158 strcpy(info->bus_info, "tap"); 1159 break; 1160 } 1161 } 1162 1163 static u32 tun_get_msglevel(struct net_device *dev) 1164 { 1165 #ifdef TUN_DEBUG 1166 struct tun_struct *tun = netdev_priv(dev); 1167 return tun->debug; 1168 #else 1169 return -EOPNOTSUPP; 1170 #endif 1171 } 1172 1173 static void tun_set_msglevel(struct net_device *dev, u32 value) 1174 { 1175 #ifdef TUN_DEBUG 1176 struct tun_struct *tun = netdev_priv(dev); 1177 tun->debug = value; 1178 #endif 1179 } 1180 1181 static u32 tun_get_link(struct net_device *dev) 1182 { 1183 struct tun_struct *tun = netdev_priv(dev); 1184 return tun->attached; 1185 } 1186 1187 static u32 tun_get_rx_csum(struct net_device *dev) 1188 { 1189 struct tun_struct *tun = netdev_priv(dev); 1190 return (tun->flags & TUN_NOCHECKSUM) == 0; 1191 } 1192 1193 static int tun_set_rx_csum(struct net_device *dev, u32 data) 1194 { 1195 struct tun_struct *tun = netdev_priv(dev); 1196 if (data) 1197 tun->flags &= ~TUN_NOCHECKSUM; 1198 else 1199 tun->flags |= TUN_NOCHECKSUM; 1200 return 0; 1201 } 1202 1203 static const struct ethtool_ops tun_ethtool_ops = { 1204 .get_settings = tun_get_settings, 1205 .get_drvinfo = tun_get_drvinfo, 1206 .get_msglevel = tun_get_msglevel, 1207 .set_msglevel = tun_set_msglevel, 1208 .get_link = tun_get_link, 1209 .get_rx_csum = tun_get_rx_csum, 1210 .set_rx_csum = tun_set_rx_csum 1211 }; 1212 1213 static int tun_init_net(struct net *net) 1214 { 1215 struct tun_net *tn; 1216 1217 tn = kmalloc(sizeof(*tn), GFP_KERNEL); 1218 if (tn == NULL) 1219 return -ENOMEM; 1220 1221 INIT_LIST_HEAD(&tn->dev_list); 1222 1223 if (net_assign_generic(net, tun_net_id, tn)) { 1224 kfree(tn); 1225 return -ENOMEM; 1226 } 1227 1228 return 0; 1229 } 1230 1231 static void tun_exit_net(struct net *net) 1232 { 1233 struct tun_net *tn; 1234 struct tun_struct *tun, *nxt; 1235 1236 tn = net_generic(net, tun_net_id); 1237 1238 rtnl_lock(); 1239 list_for_each_entry_safe(tun, nxt, &tn->dev_list, list) { 1240 DBG(KERN_INFO "%s cleaned up\n", tun->dev->name); 1241 unregister_netdevice(tun->dev); 1242 } 1243 rtnl_unlock(); 1244 1245 kfree(tn); 1246 } 1247 1248 static struct pernet_operations tun_net_ops = { 1249 .init = tun_init_net, 1250 .exit = tun_exit_net, 1251 }; 1252 1253 static int __init tun_init(void) 1254 { 1255 int ret = 0; 1256 1257 printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION); 1258 printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT); 1259 1260 ret = register_pernet_gen_device(&tun_net_id, &tun_net_ops); 1261 if (ret) { 1262 printk(KERN_ERR "tun: Can't register pernet ops\n"); 1263 goto err_pernet; 1264 } 1265 1266 ret = misc_register(&tun_miscdev); 1267 if (ret) { 1268 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR); 1269 goto err_misc; 1270 } 1271 return 0; 1272 1273 err_misc: 1274 unregister_pernet_gen_device(tun_net_id, &tun_net_ops); 1275 err_pernet: 1276 return ret; 1277 } 1278 1279 static void tun_cleanup(void) 1280 { 1281 misc_deregister(&tun_miscdev); 1282 unregister_pernet_gen_device(tun_net_id, &tun_net_ops); 1283 } 1284 1285 module_init(tun_init); 1286 module_exit(tun_cleanup); 1287 MODULE_DESCRIPTION(DRV_DESCRIPTION); 1288 MODULE_AUTHOR(DRV_COPYRIGHT); 1289 MODULE_LICENSE("GPL"); 1290 MODULE_ALIAS_MISCDEV(TUN_MINOR); 1291