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 * Brian Braunstein <linuxkernel@bristyle.com> 2007/03/23 22 * Fixed hw address handling. Now net_device.dev_addr is kept consistent 23 * with tun.dev_addr when the address is set by this module. 24 * 25 * Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14 26 * Add TUNSETLINK ioctl to set the link encapsulation 27 * 28 * Mark Smith <markzzzsmith@yahoo.com.au> 29 * Use random_ether_addr() for tap MAC address. 30 * 31 * Harald Roelle <harald.roelle@ifi.lmu.de> 2004/04/20 32 * Fixes in packet dropping, queue length setting and queue wakeup. 33 * Increased default tx queue length. 34 * Added ethtool API. 35 * Minor cleanups 36 * 37 * Daniel Podlejski <underley@underley.eu.org> 38 * Modifications for 2.3.99-pre5 kernel. 39 */ 40 41 #define DRV_NAME "tun" 42 #define DRV_VERSION "1.6" 43 #define DRV_DESCRIPTION "Universal TUN/TAP device driver" 44 #define DRV_COPYRIGHT "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>" 45 46 #include <linux/module.h> 47 #include <linux/errno.h> 48 #include <linux/kernel.h> 49 #include <linux/major.h> 50 #include <linux/slab.h> 51 #include <linux/poll.h> 52 #include <linux/fcntl.h> 53 #include <linux/init.h> 54 #include <linux/skbuff.h> 55 #include <linux/netdevice.h> 56 #include <linux/etherdevice.h> 57 #include <linux/miscdevice.h> 58 #include <linux/ethtool.h> 59 #include <linux/rtnetlink.h> 60 #include <linux/if.h> 61 #include <linux/if_arp.h> 62 #include <linux/if_ether.h> 63 #include <linux/if_tun.h> 64 #include <linux/crc32.h> 65 #include <linux/nsproxy.h> 66 #include <net/net_namespace.h> 67 #include <net/netns/generic.h> 68 69 #include <asm/system.h> 70 #include <asm/uaccess.h> 71 72 /* Uncomment to enable debugging */ 73 /* #define TUN_DEBUG 1 */ 74 75 #ifdef TUN_DEBUG 76 static int debug; 77 78 #define DBG if(tun->debug)printk 79 #define DBG1 if(debug==2)printk 80 #else 81 #define DBG( a... ) 82 #define DBG1( a... ) 83 #endif 84 85 struct tun_struct { 86 struct list_head list; 87 unsigned long flags; 88 int attached; 89 uid_t owner; 90 gid_t group; 91 92 wait_queue_head_t read_wait; 93 struct sk_buff_head readq; 94 95 struct net_device *dev; 96 97 struct fasync_struct *fasync; 98 99 unsigned long if_flags; 100 u8 dev_addr[ETH_ALEN]; 101 u32 chr_filter[2]; 102 u32 net_filter[2]; 103 104 #ifdef TUN_DEBUG 105 int debug; 106 #endif 107 }; 108 109 /* Network device part of the driver */ 110 111 static unsigned int tun_net_id; 112 struct tun_net { 113 struct list_head dev_list; 114 }; 115 116 static const struct ethtool_ops tun_ethtool_ops; 117 118 /* Net device open. */ 119 static int tun_net_open(struct net_device *dev) 120 { 121 netif_start_queue(dev); 122 return 0; 123 } 124 125 /* Net device close. */ 126 static int tun_net_close(struct net_device *dev) 127 { 128 netif_stop_queue(dev); 129 return 0; 130 } 131 132 /* Net device start xmit */ 133 static int tun_net_xmit(struct sk_buff *skb, struct net_device *dev) 134 { 135 struct tun_struct *tun = netdev_priv(dev); 136 137 DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len); 138 139 /* Drop packet if interface is not attached */ 140 if (!tun->attached) 141 goto drop; 142 143 /* Packet dropping */ 144 if (skb_queue_len(&tun->readq) >= dev->tx_queue_len) { 145 if (!(tun->flags & TUN_ONE_QUEUE)) { 146 /* Normal queueing mode. */ 147 /* Packet scheduler handles dropping of further packets. */ 148 netif_stop_queue(dev); 149 150 /* We won't see all dropped packets individually, so overrun 151 * error is more appropriate. */ 152 dev->stats.tx_fifo_errors++; 153 } else { 154 /* Single queue mode. 155 * Driver handles dropping of all packets itself. */ 156 goto drop; 157 } 158 } 159 160 /* Queue packet */ 161 skb_queue_tail(&tun->readq, skb); 162 dev->trans_start = jiffies; 163 164 /* Notify and wake up reader process */ 165 if (tun->flags & TUN_FASYNC) 166 kill_fasync(&tun->fasync, SIGIO, POLL_IN); 167 wake_up_interruptible(&tun->read_wait); 168 return 0; 169 170 drop: 171 dev->stats.tx_dropped++; 172 kfree_skb(skb); 173 return 0; 174 } 175 176 /** Add the specified Ethernet address to this multicast filter. */ 177 static void 178 add_multi(u32* filter, const u8* addr) 179 { 180 int bit_nr = ether_crc(ETH_ALEN, addr) >> 26; 181 filter[bit_nr >> 5] |= 1 << (bit_nr & 31); 182 } 183 184 /** Remove the specified Ethernet addres from this multicast filter. */ 185 static void 186 del_multi(u32* filter, const u8* addr) 187 { 188 int bit_nr = ether_crc(ETH_ALEN, addr) >> 26; 189 filter[bit_nr >> 5] &= ~(1 << (bit_nr & 31)); 190 } 191 192 /** Update the list of multicast groups to which the network device belongs. 193 * This list is used to filter packets being sent from the character device to 194 * the network device. */ 195 static void 196 tun_net_mclist(struct net_device *dev) 197 { 198 struct tun_struct *tun = netdev_priv(dev); 199 const struct dev_mc_list *mclist; 200 int i; 201 DECLARE_MAC_BUF(mac); 202 DBG(KERN_DEBUG "%s: tun_net_mclist: mc_count %d\n", 203 dev->name, dev->mc_count); 204 memset(tun->chr_filter, 0, sizeof tun->chr_filter); 205 for (i = 0, mclist = dev->mc_list; i < dev->mc_count && mclist != NULL; 206 i++, mclist = mclist->next) { 207 add_multi(tun->net_filter, mclist->dmi_addr); 208 DBG(KERN_DEBUG "%s: tun_net_mclist: %s\n", 209 dev->name, print_mac(mac, mclist->dmi_addr)); 210 } 211 } 212 213 #define MIN_MTU 68 214 #define MAX_MTU 65535 215 216 static int 217 tun_net_change_mtu(struct net_device *dev, int new_mtu) 218 { 219 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU) 220 return -EINVAL; 221 dev->mtu = new_mtu; 222 return 0; 223 } 224 225 /* Initialize net device. */ 226 static void tun_net_init(struct net_device *dev) 227 { 228 struct tun_struct *tun = netdev_priv(dev); 229 230 switch (tun->flags & TUN_TYPE_MASK) { 231 case TUN_TUN_DEV: 232 /* Point-to-Point TUN Device */ 233 dev->hard_header_len = 0; 234 dev->addr_len = 0; 235 dev->mtu = 1500; 236 dev->change_mtu = tun_net_change_mtu; 237 238 /* Zero header length */ 239 dev->type = ARPHRD_NONE; 240 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 241 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */ 242 break; 243 244 case TUN_TAP_DEV: 245 /* Ethernet TAP Device */ 246 dev->set_multicast_list = tun_net_mclist; 247 248 ether_setup(dev); 249 dev->change_mtu = tun_net_change_mtu; 250 251 /* random address already created for us by tun_set_iff, use it */ 252 memcpy(dev->dev_addr, tun->dev_addr, min(sizeof(tun->dev_addr), sizeof(dev->dev_addr)) ); 253 254 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */ 255 break; 256 } 257 } 258 259 /* Character device part */ 260 261 /* Poll */ 262 static unsigned int tun_chr_poll(struct file *file, poll_table * wait) 263 { 264 struct tun_struct *tun = file->private_data; 265 unsigned int mask = POLLOUT | POLLWRNORM; 266 267 if (!tun) 268 return -EBADFD; 269 270 DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name); 271 272 poll_wait(file, &tun->read_wait, wait); 273 274 if (!skb_queue_empty(&tun->readq)) 275 mask |= POLLIN | POLLRDNORM; 276 277 return mask; 278 } 279 280 /* Get packet from user space buffer */ 281 static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, size_t count) 282 { 283 struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) }; 284 struct sk_buff *skb; 285 size_t len = count, align = 0; 286 287 if (!(tun->flags & TUN_NO_PI)) { 288 if ((len -= sizeof(pi)) > count) 289 return -EINVAL; 290 291 if(memcpy_fromiovec((void *)&pi, iv, sizeof(pi))) 292 return -EFAULT; 293 } 294 295 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) { 296 align = NET_IP_ALIGN; 297 if (unlikely(len < ETH_HLEN)) 298 return -EINVAL; 299 } 300 301 if (!(skb = alloc_skb(len + align, GFP_KERNEL))) { 302 tun->dev->stats.rx_dropped++; 303 return -ENOMEM; 304 } 305 306 if (align) 307 skb_reserve(skb, align); 308 if (memcpy_fromiovec(skb_put(skb, len), iv, len)) { 309 tun->dev->stats.rx_dropped++; 310 kfree_skb(skb); 311 return -EFAULT; 312 } 313 314 switch (tun->flags & TUN_TYPE_MASK) { 315 case TUN_TUN_DEV: 316 skb_reset_mac_header(skb); 317 skb->protocol = pi.proto; 318 skb->dev = tun->dev; 319 break; 320 case TUN_TAP_DEV: 321 skb->protocol = eth_type_trans(skb, tun->dev); 322 break; 323 }; 324 325 if (tun->flags & TUN_NOCHECKSUM) 326 skb->ip_summed = CHECKSUM_UNNECESSARY; 327 328 netif_rx_ni(skb); 329 tun->dev->last_rx = jiffies; 330 331 tun->dev->stats.rx_packets++; 332 tun->dev->stats.rx_bytes += len; 333 334 return count; 335 } 336 337 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv, 338 unsigned long count, loff_t pos) 339 { 340 struct tun_struct *tun = iocb->ki_filp->private_data; 341 342 if (!tun) 343 return -EBADFD; 344 345 DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count); 346 347 return tun_get_user(tun, (struct iovec *) iv, iov_length(iv, count)); 348 } 349 350 /* Put packet to the user space buffer */ 351 static __inline__ ssize_t tun_put_user(struct tun_struct *tun, 352 struct sk_buff *skb, 353 struct iovec *iv, int len) 354 { 355 struct tun_pi pi = { 0, skb->protocol }; 356 ssize_t total = 0; 357 358 if (!(tun->flags & TUN_NO_PI)) { 359 if ((len -= sizeof(pi)) < 0) 360 return -EINVAL; 361 362 if (len < skb->len) { 363 /* Packet will be striped */ 364 pi.flags |= TUN_PKT_STRIP; 365 } 366 367 if (memcpy_toiovec(iv, (void *) &pi, sizeof(pi))) 368 return -EFAULT; 369 total += sizeof(pi); 370 } 371 372 len = min_t(int, skb->len, len); 373 374 skb_copy_datagram_iovec(skb, 0, iv, len); 375 total += len; 376 377 tun->dev->stats.tx_packets++; 378 tun->dev->stats.tx_bytes += len; 379 380 return total; 381 } 382 383 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv, 384 unsigned long count, loff_t pos) 385 { 386 struct file *file = iocb->ki_filp; 387 struct tun_struct *tun = file->private_data; 388 DECLARE_WAITQUEUE(wait, current); 389 struct sk_buff *skb; 390 ssize_t len, ret = 0; 391 DECLARE_MAC_BUF(mac); 392 393 if (!tun) 394 return -EBADFD; 395 396 DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name); 397 398 len = iov_length(iv, count); 399 if (len < 0) 400 return -EINVAL; 401 402 add_wait_queue(&tun->read_wait, &wait); 403 while (len) { 404 const u8 ones[ ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; 405 u8 addr[ ETH_ALEN]; 406 int bit_nr; 407 408 current->state = TASK_INTERRUPTIBLE; 409 410 /* Read frames from the queue */ 411 if (!(skb=skb_dequeue(&tun->readq))) { 412 if (file->f_flags & O_NONBLOCK) { 413 ret = -EAGAIN; 414 break; 415 } 416 if (signal_pending(current)) { 417 ret = -ERESTARTSYS; 418 break; 419 } 420 421 /* Nothing to read, let's sleep */ 422 schedule(); 423 continue; 424 } 425 netif_wake_queue(tun->dev); 426 427 /** Decide whether to accept this packet. This code is designed to 428 * behave identically to an Ethernet interface. Accept the packet if 429 * - we are promiscuous. 430 * - the packet is addressed to us. 431 * - the packet is broadcast. 432 * - the packet is multicast and 433 * - we are multicast promiscous. 434 * - we belong to the multicast group. 435 */ 436 skb_copy_from_linear_data(skb, addr, min_t(size_t, sizeof addr, 437 skb->len)); 438 bit_nr = ether_crc(sizeof addr, addr) >> 26; 439 if ((tun->if_flags & IFF_PROMISC) || 440 memcmp(addr, tun->dev_addr, sizeof addr) == 0 || 441 memcmp(addr, ones, sizeof addr) == 0 || 442 (((addr[0] == 1 && addr[1] == 0 && addr[2] == 0x5e) || 443 (addr[0] == 0x33 && addr[1] == 0x33)) && 444 ((tun->if_flags & IFF_ALLMULTI) || 445 (tun->chr_filter[bit_nr >> 5] & (1 << (bit_nr & 31)))))) { 446 DBG(KERN_DEBUG "%s: tun_chr_readv: accepted: %s\n", 447 tun->dev->name, print_mac(mac, addr)); 448 ret = tun_put_user(tun, skb, (struct iovec *) iv, len); 449 kfree_skb(skb); 450 break; 451 } else { 452 DBG(KERN_DEBUG "%s: tun_chr_readv: rejected: %s\n", 453 tun->dev->name, print_mac(mac, addr)); 454 kfree_skb(skb); 455 continue; 456 } 457 } 458 459 current->state = TASK_RUNNING; 460 remove_wait_queue(&tun->read_wait, &wait); 461 462 return ret; 463 } 464 465 static void tun_setup(struct net_device *dev) 466 { 467 struct tun_struct *tun = netdev_priv(dev); 468 469 skb_queue_head_init(&tun->readq); 470 init_waitqueue_head(&tun->read_wait); 471 472 tun->owner = -1; 473 tun->group = -1; 474 475 dev->open = tun_net_open; 476 dev->hard_start_xmit = tun_net_xmit; 477 dev->stop = tun_net_close; 478 dev->ethtool_ops = &tun_ethtool_ops; 479 dev->destructor = free_netdev; 480 dev->features |= NETIF_F_NETNS_LOCAL; 481 } 482 483 static struct tun_struct *tun_get_by_name(struct tun_net *tn, const char *name) 484 { 485 struct tun_struct *tun; 486 487 ASSERT_RTNL(); 488 list_for_each_entry(tun, &tn->dev_list, list) { 489 if (!strncmp(tun->dev->name, name, IFNAMSIZ)) 490 return tun; 491 } 492 493 return NULL; 494 } 495 496 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) 497 { 498 struct tun_net *tn; 499 struct tun_struct *tun; 500 struct net_device *dev; 501 int err; 502 503 tn = net_generic(net, tun_net_id); 504 tun = tun_get_by_name(tn, ifr->ifr_name); 505 if (tun) { 506 if (tun->attached) 507 return -EBUSY; 508 509 /* Check permissions */ 510 if (((tun->owner != -1 && 511 current->euid != tun->owner) || 512 (tun->group != -1 && 513 current->egid != tun->group)) && 514 !capable(CAP_NET_ADMIN)) 515 return -EPERM; 516 } 517 else if (__dev_get_by_name(net, ifr->ifr_name)) 518 return -EINVAL; 519 else { 520 char *name; 521 unsigned long flags = 0; 522 523 err = -EINVAL; 524 525 if (!capable(CAP_NET_ADMIN)) 526 return -EPERM; 527 528 /* Set dev type */ 529 if (ifr->ifr_flags & IFF_TUN) { 530 /* TUN device */ 531 flags |= TUN_TUN_DEV; 532 name = "tun%d"; 533 } else if (ifr->ifr_flags & IFF_TAP) { 534 /* TAP device */ 535 flags |= TUN_TAP_DEV; 536 name = "tap%d"; 537 } else 538 goto failed; 539 540 if (*ifr->ifr_name) 541 name = ifr->ifr_name; 542 543 dev = alloc_netdev(sizeof(struct tun_struct), name, 544 tun_setup); 545 if (!dev) 546 return -ENOMEM; 547 548 dev_net_set(dev, net); 549 tun = netdev_priv(dev); 550 tun->dev = dev; 551 tun->flags = flags; 552 /* Be promiscuous by default to maintain previous behaviour. */ 553 tun->if_flags = IFF_PROMISC; 554 /* Generate random Ethernet address. */ 555 *(__be16 *)tun->dev_addr = htons(0x00FF); 556 get_random_bytes(tun->dev_addr + sizeof(u16), 4); 557 memset(tun->chr_filter, 0, sizeof tun->chr_filter); 558 559 tun_net_init(dev); 560 561 if (strchr(dev->name, '%')) { 562 err = dev_alloc_name(dev, dev->name); 563 if (err < 0) 564 goto err_free_dev; 565 } 566 567 err = register_netdevice(tun->dev); 568 if (err < 0) 569 goto err_free_dev; 570 571 list_add(&tun->list, &tn->dev_list); 572 } 573 574 DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name); 575 576 if (ifr->ifr_flags & IFF_NO_PI) 577 tun->flags |= TUN_NO_PI; 578 else 579 tun->flags &= ~TUN_NO_PI; 580 581 if (ifr->ifr_flags & IFF_ONE_QUEUE) 582 tun->flags |= TUN_ONE_QUEUE; 583 else 584 tun->flags &= ~TUN_ONE_QUEUE; 585 586 file->private_data = tun; 587 tun->attached = 1; 588 get_net(dev_net(tun->dev)); 589 590 strcpy(ifr->ifr_name, tun->dev->name); 591 return 0; 592 593 err_free_dev: 594 free_netdev(dev); 595 failed: 596 return err; 597 } 598 599 static int tun_chr_ioctl(struct inode *inode, struct file *file, 600 unsigned int cmd, unsigned long arg) 601 { 602 struct tun_struct *tun = file->private_data; 603 void __user* argp = (void __user*)arg; 604 struct ifreq ifr; 605 DECLARE_MAC_BUF(mac); 606 607 if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89) 608 if (copy_from_user(&ifr, argp, sizeof ifr)) 609 return -EFAULT; 610 611 if (cmd == TUNSETIFF && !tun) { 612 int err; 613 614 ifr.ifr_name[IFNAMSIZ-1] = '\0'; 615 616 rtnl_lock(); 617 err = tun_set_iff(current->nsproxy->net_ns, file, &ifr); 618 rtnl_unlock(); 619 620 if (err) 621 return err; 622 623 if (copy_to_user(argp, &ifr, sizeof(ifr))) 624 return -EFAULT; 625 return 0; 626 } 627 628 if (!tun) 629 return -EBADFD; 630 631 DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd); 632 633 switch (cmd) { 634 case TUNSETNOCSUM: 635 /* Disable/Enable checksum */ 636 if (arg) 637 tun->flags |= TUN_NOCHECKSUM; 638 else 639 tun->flags &= ~TUN_NOCHECKSUM; 640 641 DBG(KERN_INFO "%s: checksum %s\n", 642 tun->dev->name, arg ? "disabled" : "enabled"); 643 break; 644 645 case TUNSETPERSIST: 646 /* Disable/Enable persist mode */ 647 if (arg) 648 tun->flags |= TUN_PERSIST; 649 else 650 tun->flags &= ~TUN_PERSIST; 651 652 DBG(KERN_INFO "%s: persist %s\n", 653 tun->dev->name, arg ? "enabled" : "disabled"); 654 break; 655 656 case TUNSETOWNER: 657 /* Set owner of the device */ 658 tun->owner = (uid_t) arg; 659 660 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner); 661 break; 662 663 case TUNSETGROUP: 664 /* Set group of the device */ 665 tun->group= (gid_t) arg; 666 667 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group); 668 break; 669 670 case TUNSETLINK: 671 { 672 int ret; 673 674 /* Only allow setting the type when the interface is down */ 675 rtnl_lock(); 676 if (tun->dev->flags & IFF_UP) { 677 DBG(KERN_INFO "%s: Linktype set failed because interface is up\n", 678 tun->dev->name); 679 ret = -EBUSY; 680 } else { 681 tun->dev->type = (int) arg; 682 DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type); 683 ret = 0; 684 } 685 rtnl_unlock(); 686 return ret; 687 } 688 689 #ifdef TUN_DEBUG 690 case TUNSETDEBUG: 691 tun->debug = arg; 692 break; 693 #endif 694 695 case SIOCGIFFLAGS: 696 ifr.ifr_flags = tun->if_flags; 697 if (copy_to_user( argp, &ifr, sizeof ifr)) 698 return -EFAULT; 699 return 0; 700 701 case SIOCSIFFLAGS: 702 /** Set the character device's interface flags. Currently only 703 * IFF_PROMISC and IFF_ALLMULTI are used. */ 704 tun->if_flags = ifr.ifr_flags; 705 DBG(KERN_INFO "%s: interface flags 0x%lx\n", 706 tun->dev->name, tun->if_flags); 707 return 0; 708 709 case SIOCGIFHWADDR: 710 /* Note: the actual net device's address may be different */ 711 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev_addr, 712 min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr)); 713 if (copy_to_user( argp, &ifr, sizeof ifr)) 714 return -EFAULT; 715 return 0; 716 717 case SIOCSIFHWADDR: 718 { 719 /* try to set the actual net device's hw address */ 720 int ret; 721 722 rtnl_lock(); 723 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr); 724 rtnl_unlock(); 725 726 if (ret == 0) { 727 /** Set the character device's hardware address. This is used when 728 * filtering packets being sent from the network device to the character 729 * device. */ 730 memcpy(tun->dev_addr, ifr.ifr_hwaddr.sa_data, 731 min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr)); 732 DBG(KERN_DEBUG "%s: set hardware address: %x:%x:%x:%x:%x:%x\n", 733 tun->dev->name, 734 tun->dev_addr[0], tun->dev_addr[1], tun->dev_addr[2], 735 tun->dev_addr[3], tun->dev_addr[4], tun->dev_addr[5]); 736 } 737 738 return ret; 739 } 740 741 case SIOCADDMULTI: 742 /** Add the specified group to the character device's multicast filter 743 * list. */ 744 rtnl_lock(); 745 netif_tx_lock_bh(tun->dev); 746 add_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data); 747 netif_tx_unlock_bh(tun->dev); 748 rtnl_unlock(); 749 750 DBG(KERN_DEBUG "%s: add multi: %s\n", 751 tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data)); 752 return 0; 753 754 case SIOCDELMULTI: 755 /** Remove the specified group from the character device's multicast 756 * filter list. */ 757 rtnl_lock(); 758 netif_tx_lock_bh(tun->dev); 759 del_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data); 760 netif_tx_unlock_bh(tun->dev); 761 rtnl_unlock(); 762 763 DBG(KERN_DEBUG "%s: del multi: %s\n", 764 tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data)); 765 return 0; 766 767 default: 768 return -EINVAL; 769 }; 770 771 return 0; 772 } 773 774 static int tun_chr_fasync(int fd, struct file *file, int on) 775 { 776 struct tun_struct *tun = file->private_data; 777 int ret; 778 779 if (!tun) 780 return -EBADFD; 781 782 DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on); 783 784 if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0) 785 return ret; 786 787 if (on) { 788 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0); 789 if (ret) 790 return ret; 791 tun->flags |= TUN_FASYNC; 792 } else 793 tun->flags &= ~TUN_FASYNC; 794 795 return 0; 796 } 797 798 static int tun_chr_open(struct inode *inode, struct file * file) 799 { 800 DBG1(KERN_INFO "tunX: tun_chr_open\n"); 801 file->private_data = NULL; 802 return 0; 803 } 804 805 static int tun_chr_close(struct inode *inode, struct file *file) 806 { 807 struct tun_struct *tun = file->private_data; 808 809 if (!tun) 810 return 0; 811 812 DBG(KERN_INFO "%s: tun_chr_close\n", tun->dev->name); 813 814 tun_chr_fasync(-1, file, 0); 815 816 rtnl_lock(); 817 818 /* Detach from net device */ 819 file->private_data = NULL; 820 tun->attached = 0; 821 put_net(dev_net(tun->dev)); 822 823 /* Drop read queue */ 824 skb_queue_purge(&tun->readq); 825 826 if (!(tun->flags & TUN_PERSIST)) { 827 list_del(&tun->list); 828 unregister_netdevice(tun->dev); 829 } 830 831 rtnl_unlock(); 832 833 return 0; 834 } 835 836 static const struct file_operations tun_fops = { 837 .owner = THIS_MODULE, 838 .llseek = no_llseek, 839 .read = do_sync_read, 840 .aio_read = tun_chr_aio_read, 841 .write = do_sync_write, 842 .aio_write = tun_chr_aio_write, 843 .poll = tun_chr_poll, 844 .ioctl = tun_chr_ioctl, 845 .open = tun_chr_open, 846 .release = tun_chr_close, 847 .fasync = tun_chr_fasync 848 }; 849 850 static struct miscdevice tun_miscdev = { 851 .minor = TUN_MINOR, 852 .name = "tun", 853 .fops = &tun_fops, 854 }; 855 856 /* ethtool interface */ 857 858 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd) 859 { 860 cmd->supported = 0; 861 cmd->advertising = 0; 862 cmd->speed = SPEED_10; 863 cmd->duplex = DUPLEX_FULL; 864 cmd->port = PORT_TP; 865 cmd->phy_address = 0; 866 cmd->transceiver = XCVR_INTERNAL; 867 cmd->autoneg = AUTONEG_DISABLE; 868 cmd->maxtxpkt = 0; 869 cmd->maxrxpkt = 0; 870 return 0; 871 } 872 873 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info) 874 { 875 struct tun_struct *tun = netdev_priv(dev); 876 877 strcpy(info->driver, DRV_NAME); 878 strcpy(info->version, DRV_VERSION); 879 strcpy(info->fw_version, "N/A"); 880 881 switch (tun->flags & TUN_TYPE_MASK) { 882 case TUN_TUN_DEV: 883 strcpy(info->bus_info, "tun"); 884 break; 885 case TUN_TAP_DEV: 886 strcpy(info->bus_info, "tap"); 887 break; 888 } 889 } 890 891 static u32 tun_get_msglevel(struct net_device *dev) 892 { 893 #ifdef TUN_DEBUG 894 struct tun_struct *tun = netdev_priv(dev); 895 return tun->debug; 896 #else 897 return -EOPNOTSUPP; 898 #endif 899 } 900 901 static void tun_set_msglevel(struct net_device *dev, u32 value) 902 { 903 #ifdef TUN_DEBUG 904 struct tun_struct *tun = netdev_priv(dev); 905 tun->debug = value; 906 #endif 907 } 908 909 static u32 tun_get_link(struct net_device *dev) 910 { 911 struct tun_struct *tun = netdev_priv(dev); 912 return tun->attached; 913 } 914 915 static u32 tun_get_rx_csum(struct net_device *dev) 916 { 917 struct tun_struct *tun = netdev_priv(dev); 918 return (tun->flags & TUN_NOCHECKSUM) == 0; 919 } 920 921 static int tun_set_rx_csum(struct net_device *dev, u32 data) 922 { 923 struct tun_struct *tun = netdev_priv(dev); 924 if (data) 925 tun->flags &= ~TUN_NOCHECKSUM; 926 else 927 tun->flags |= TUN_NOCHECKSUM; 928 return 0; 929 } 930 931 static const struct ethtool_ops tun_ethtool_ops = { 932 .get_settings = tun_get_settings, 933 .get_drvinfo = tun_get_drvinfo, 934 .get_msglevel = tun_get_msglevel, 935 .set_msglevel = tun_set_msglevel, 936 .get_link = tun_get_link, 937 .get_rx_csum = tun_get_rx_csum, 938 .set_rx_csum = tun_set_rx_csum 939 }; 940 941 static int tun_init_net(struct net *net) 942 { 943 struct tun_net *tn; 944 945 tn = kmalloc(sizeof(*tn), GFP_KERNEL); 946 if (tn == NULL) 947 return -ENOMEM; 948 949 INIT_LIST_HEAD(&tn->dev_list); 950 951 if (net_assign_generic(net, tun_net_id, tn)) { 952 kfree(tn); 953 return -ENOMEM; 954 } 955 956 return 0; 957 } 958 959 static void tun_exit_net(struct net *net) 960 { 961 struct tun_net *tn; 962 struct tun_struct *tun, *nxt; 963 964 tn = net_generic(net, tun_net_id); 965 966 rtnl_lock(); 967 list_for_each_entry_safe(tun, nxt, &tn->dev_list, list) { 968 DBG(KERN_INFO "%s cleaned up\n", tun->dev->name); 969 unregister_netdevice(tun->dev); 970 } 971 rtnl_unlock(); 972 973 kfree(tn); 974 } 975 976 static struct pernet_operations tun_net_ops = { 977 .init = tun_init_net, 978 .exit = tun_exit_net, 979 }; 980 981 static int __init tun_init(void) 982 { 983 int ret = 0; 984 985 printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION); 986 printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT); 987 988 ret = register_pernet_gen_device(&tun_net_id, &tun_net_ops); 989 if (ret) { 990 printk(KERN_ERR "tun: Can't register pernet ops\n"); 991 goto err_pernet; 992 } 993 994 ret = misc_register(&tun_miscdev); 995 if (ret) { 996 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR); 997 goto err_misc; 998 } 999 return 0; 1000 1001 err_misc: 1002 unregister_pernet_gen_device(tun_net_id, &tun_net_ops); 1003 err_pernet: 1004 return ret; 1005 } 1006 1007 static void tun_cleanup(void) 1008 { 1009 misc_deregister(&tun_miscdev); 1010 unregister_pernet_gen_device(tun_net_id, &tun_net_ops); 1011 } 1012 1013 module_init(tun_init); 1014 module_exit(tun_cleanup); 1015 MODULE_DESCRIPTION(DRV_DESCRIPTION); 1016 MODULE_AUTHOR(DRV_COPYRIGHT); 1017 MODULE_LICENSE("GPL"); 1018 MODULE_ALIAS_MISCDEV(TUN_MINOR); 1019