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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 | /* * TUN - Universal TUN/TAP device driver. * Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $ */ /* * Daniel Podlejski <underley@underley.eu.org> * Modifications for 2.3.99-pre5 kernel. */ #define TUN_VER "1.5" #include <linux/config.h> #include <linux/module.h> #include <linux/errno.h> #include <linux/kernel.h> #include <linux/major.h> #include <linux/slab.h> #include <linux/poll.h> #include <linux/fcntl.h> #include <linux/init.h> #include <linux/random.h> #include <linux/skbuff.h> #include <linux/netdevice.h> #include <linux/etherdevice.h> #include <linux/miscdevice.h> #include <linux/rtnetlink.h> #include <linux/if.h> #include <linux/if_arp.h> #include <linux/if_ether.h> #include <linux/if_tun.h> #include <asm/system.h> #include <asm/uaccess.h> #ifdef TUN_DEBUG static int debug; #endif /* Network device part of the driver */ /* Net device open. */ static int tun_net_open(struct net_device *dev) { netif_start_queue(dev); return 0; } /* Net device close. */ static int tun_net_close(struct net_device *dev) { netif_stop_queue(dev); return 0; } /* Net device start xmit */ static int tun_net_xmit(struct sk_buff *skb, struct net_device *dev) { struct tun_struct *tun = (struct tun_struct *)dev->priv; DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->name, skb->len); /* Drop packet if interface is not attached */ if (!tun->attached) goto drop; /* Queue packet */ if (!(tun->flags & TUN_ONE_QUEUE)) { /* Normal queueing mode. * Packet scheduler handles dropping. */ if (skb_queue_len(&tun->readq) >= TUN_READQ_SIZE) netif_stop_queue(dev); } else { /* Single queue mode. * Driver handles dropping itself. */ if (skb_queue_len(&tun->readq) >= dev->tx_queue_len) goto drop; } skb_queue_tail(&tun->readq, skb); /* Notify and wake up reader process */ if (tun->flags & TUN_FASYNC) kill_fasync(&tun->fasync, SIGIO, POLL_IN); wake_up_interruptible(&tun->read_wait); return 0; drop: tun->stats.tx_dropped++; kfree_skb(skb); return 0; } static void tun_net_mclist(struct net_device *dev) { /* Nothing to do for multicast filters. * We always accept all frames. */ return; } static struct net_device_stats *tun_net_stats(struct net_device *dev) { struct tun_struct *tun = (struct tun_struct *)dev->priv; return &tun->stats; } /* Initialize net device. */ int tun_net_init(struct net_device *dev) { struct tun_struct *tun = (struct tun_struct *)dev->priv; DBG(KERN_INFO "%s: tun_net_init\n", tun->name); SET_MODULE_OWNER(dev); dev->open = tun_net_open; dev->hard_start_xmit = tun_net_xmit; dev->stop = tun_net_close; dev->get_stats = tun_net_stats; switch (tun->flags & TUN_TYPE_MASK) { case TUN_TUN_DEV: /* Point-to-Point TUN Device */ dev->hard_header_len = 0; dev->addr_len = 0; dev->mtu = 1500; /* Type PPP seems most suitable */ dev->type = ARPHRD_PPP; dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; dev->tx_queue_len = 10; break; case TUN_TAP_DEV: /* Ethernet TAP Device */ dev->set_multicast_list = tun_net_mclist; /* Generate random Ethernet address. */ *(u16 *)dev->dev_addr = htons(0x00FF); get_random_bytes(dev->dev_addr + sizeof(u16), 4); ether_setup(dev); break; }; return 0; } /* Character device part */ /* Poll */ static unsigned int tun_chr_poll(struct file *file, poll_table * wait) { struct tun_struct *tun = (struct tun_struct *)file->private_data; unsigned int mask = POLLOUT | POLLWRNORM; if (!tun) return -EBADFD; DBG(KERN_INFO "%s: tun_chr_poll\n", tun->name); poll_wait(file, &tun->read_wait, wait); if (skb_queue_len(&tun->readq)) mask |= POLLIN | POLLRDNORM; return mask; } /* Get packet from user space buffer(already verified) */ static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, size_t count) { struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) }; struct sk_buff *skb; size_t len = count; if (!(tun->flags & TUN_NO_PI)) { if ((len -= sizeof(pi)) < 0) return -EINVAL; memcpy_fromiovec((void *)&pi, iv, sizeof(pi)); } if (!(skb = alloc_skb(len + 2, GFP_KERNEL))) { tun->stats.rx_dropped++; return -ENOMEM; } skb_reserve(skb, 2); memcpy_fromiovec(skb_put(skb, len), iv, len); skb->dev = &tun->dev; switch (tun->flags & TUN_TYPE_MASK) { case TUN_TUN_DEV: skb->mac.raw = skb->data; skb->protocol = pi.proto; break; case TUN_TAP_DEV: skb->protocol = eth_type_trans(skb, &tun->dev); break; }; if (tun->flags & TUN_NOCHECKSUM) skb->ip_summed = CHECKSUM_UNNECESSARY; netif_rx_ni(skb); tun->stats.rx_packets++; tun->stats.rx_bytes += len; return count; } /* Writev */ static ssize_t tun_chr_writev(struct file * file, const struct iovec *iv, unsigned long count, loff_t *pos) { struct tun_struct *tun = (struct tun_struct *)file->private_data; unsigned long i; size_t len; if (!tun) return -EBADFD; DBG(KERN_INFO "%s: tun_chr_write %d\n", tun->name, count); for (i = 0, len = 0; i < count; i++) { if (verify_area(VERIFY_READ, iv[i].iov_base, iv[i].iov_len)) return -EFAULT; len += iv[i].iov_len; } return tun_get_user(tun, (struct iovec *) iv, len); } /* Write */ static ssize_t tun_chr_write(struct file * file, const char * buf, size_t count, loff_t *pos) { struct iovec iv = { (void *) buf, count }; return tun_chr_writev(file, &iv, 1, pos); } /* Put packet to the user space buffer (already verified) */ static __inline__ ssize_t tun_put_user(struct tun_struct *tun, struct sk_buff *skb, struct iovec *iv, int len) { struct tun_pi pi = { 0, skb->protocol }; ssize_t total = 0; if (!(tun->flags & TUN_NO_PI)) { if ((len -= sizeof(pi)) < 0) return -EINVAL; if (len < skb->len) { /* Packet will be striped */ pi.flags |= TUN_PKT_STRIP; } memcpy_toiovec(iv, (void *) &pi, sizeof(pi)); total += sizeof(pi); } len = min_t(int, skb->len, len); skb_copy_datagram_iovec(skb, 0, iv, len); total += len; tun->stats.tx_packets++; tun->stats.tx_bytes += len; return total; } /* Readv */ static ssize_t tun_chr_readv(struct file *file, const struct iovec *iv, unsigned long count, loff_t *pos) { struct tun_struct *tun = (struct tun_struct *)file->private_data; DECLARE_WAITQUEUE(wait, current); struct sk_buff *skb; ssize_t len, ret = 0; unsigned long i; if (!tun) return -EBADFD; DBG(KERN_INFO "%s: tun_chr_read\n", tun->name); for (i = 0, len = 0; i < count; i++) { if (verify_area(VERIFY_WRITE, iv[i].iov_base, iv[i].iov_len)) return -EFAULT; len += iv[i].iov_len; } if (len < 0) return -EINVAL; add_wait_queue(&tun->read_wait, &wait); while (len) { current->state = TASK_INTERRUPTIBLE; /* Read frames from the queue */ if (!(skb=skb_dequeue(&tun->readq))) { if (file->f_flags & O_NONBLOCK) { ret = -EAGAIN; break; } if (signal_pending(current)) { ret = -ERESTARTSYS; break; } /* Nothing to read, let's sleep */ schedule(); continue; } netif_start_queue(&tun->dev); ret = tun_put_user(tun, skb, (struct iovec *) iv, len); kfree_skb(skb); break; } current->state = TASK_RUNNING; remove_wait_queue(&tun->read_wait, &wait); return ret; } /* Read */ static ssize_t tun_chr_read(struct file * file, char * buf, size_t count, loff_t *pos) { struct iovec iv = { buf, count }; return tun_chr_readv(file, &iv, 1, pos); } static int tun_set_iff(struct file *file, struct ifreq *ifr) { struct tun_struct *tun; struct net_device *dev; int err; dev = __dev_get_by_name(ifr->ifr_name); if (dev) { /* Device exist */ tun = dev->priv; if (dev->init != tun_net_init || tun->attached) return -EBUSY; /* Check permissions */ if (tun->owner != -1) if (current->euid != tun->owner && !capable(CAP_NET_ADMIN)) return -EPERM; } else { char *name; /* Allocate new device */ if (!(tun = kmalloc(sizeof(struct tun_struct), GFP_KERNEL)) ) return -ENOMEM; memset(tun, 0, sizeof(struct tun_struct)); skb_queue_head_init(&tun->readq); init_waitqueue_head(&tun->read_wait); tun->owner = -1; tun->dev.init = tun_net_init; tun->dev.priv = tun; err = -EINVAL; /* Set dev type */ if (ifr->ifr_flags & IFF_TUN) { /* TUN device */ tun->flags |= TUN_TUN_DEV; name = "tun%d"; } else if (ifr->ifr_flags & IFF_TAP) { /* TAP device */ tun->flags |= TUN_TAP_DEV; name = "tap%d"; } else goto failed; if (*ifr->ifr_name) name = ifr->ifr_name; if ((err = dev_alloc_name(&tun->dev, name)) < 0) goto failed; if ((err = register_netdevice(&tun->dev))) goto failed; MOD_INC_USE_COUNT; tun->name = tun->dev.name; } DBG(KERN_INFO "%s: tun_set_iff\n", tun->name); if (ifr->ifr_flags & IFF_NO_PI) tun->flags |= TUN_NO_PI; if (ifr->ifr_flags & IFF_ONE_QUEUE) tun->flags |= TUN_ONE_QUEUE; file->private_data = tun; tun->attached = 1; strcpy(ifr->ifr_name, tun->name); return 0; failed: kfree(tun); return err; } static int tun_chr_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) { struct tun_struct *tun = (struct tun_struct *)file->private_data; if (cmd == TUNSETIFF && !tun) { struct ifreq ifr; int err; if (copy_from_user(&ifr, (void *)arg, sizeof(ifr))) return -EFAULT; ifr.ifr_name[IFNAMSIZ-1] = '\0'; rtnl_lock(); err = tun_set_iff(file, &ifr); rtnl_unlock(); if (err) return err; copy_to_user((void *)arg, &ifr, sizeof(ifr)); return 0; } if (!tun) return -EBADFD; DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->name, cmd); switch (cmd) { case TUNSETNOCSUM: /* Disable/Enable checksum */ if (arg) tun->flags |= TUN_NOCHECKSUM; else tun->flags &= ~TUN_NOCHECKSUM; DBG(KERN_INFO "%s: checksum %s\n", tun->name, arg ? "disabled" : "enabled"); break; case TUNSETPERSIST: /* Disable/Enable persist mode */ if (arg) tun->flags |= TUN_PERSIST; else tun->flags &= ~TUN_PERSIST; DBG(KERN_INFO "%s: persist %s\n", tun->name, arg ? "disabled" : "enabled"); break; case TUNSETOWNER: /* Set owner of the device */ tun->owner = (uid_t) arg; DBG(KERN_INFO "%s: owner set to %d\n", tun->owner); break; #ifdef TUN_DEBUG case TUNSETDEBUG: tun->debug = arg; break; #endif default: return -EINVAL; }; return 0; } static int tun_chr_fasync(int fd, struct file *file, int on) { struct tun_struct *tun = (struct tun_struct *)file->private_data; int ret; if (!tun) return -EBADFD; DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->name, on); if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0) return ret; if (on) { ret = f_setown(file, current->pid, 0); if (ret) return ret; tun->flags |= TUN_FASYNC; } else tun->flags &= ~TUN_FASYNC; return 0; } static int tun_chr_open(struct inode *inode, struct file * file) { DBG1(KERN_INFO "tunX: tun_chr_open\n"); file->private_data = NULL; return 0; } static int tun_chr_close(struct inode *inode, struct file *file) { struct tun_struct *tun = (struct tun_struct *)file->private_data; if (!tun) return 0; DBG(KERN_INFO "%s: tun_chr_close\n", tun->name); tun_chr_fasync(-1, file, 0); rtnl_lock(); /* Detach from net device */ file->private_data = NULL; tun->attached = 0; /* Drop read queue */ skb_queue_purge(&tun->readq); if (!(tun->flags & TUN_PERSIST)) { dev_close(&tun->dev); unregister_netdevice(&tun->dev); kfree(tun); MOD_DEC_USE_COUNT; } rtnl_unlock(); return 0; } static struct file_operations tun_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .read = tun_chr_read, .readv = tun_chr_readv, .write = tun_chr_write, .writev = tun_chr_writev, .poll = tun_chr_poll, .ioctl = tun_chr_ioctl, .open = tun_chr_open, .release = tun_chr_close, .fasync = tun_chr_fasync }; static struct miscdevice tun_miscdev= { TUN_MINOR, "net/tun", &tun_fops }; int __init tun_init(void) { printk(KERN_INFO "Universal TUN/TAP device driver %s " "(C)1999-2002 Maxim Krasnyansky\n", TUN_VER); if (misc_register(&tun_miscdev)) { printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR); return -EIO; } return 0; } void tun_cleanup(void) { misc_deregister(&tun_miscdev); } module_init(tun_init); module_exit(tun_cleanup); MODULE_LICENSE("GPL"); |