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