1 /* 2 * Linux NET3: IP/IP protocol decoder. 3 * 4 * Version: $Id: ipip.c,v 1.50 2001/10/02 02:22:36 davem Exp $ 5 * 6 * Authors: 7 * Sam Lantinga (slouken@cs.ucdavis.edu) 02/01/95 8 * 9 * Fixes: 10 * Alan Cox : Merged and made usable non modular (its so tiny its silly as 11 * a module taking up 2 pages). 12 * Alan Cox : Fixed bug with 1.3.18 and IPIP not working (now needs to set skb->h.iph) 13 * to keep ip_forward happy. 14 * Alan Cox : More fixes for 1.3.21, and firewall fix. Maybe this will work soon 8). 15 * Kai Schulte : Fixed #defines for IP_FIREWALL->FIREWALL 16 * David Woodhouse : Perform some basic ICMP handling. 17 * IPIP Routing without decapsulation. 18 * Carlos Picoto : GRE over IP support 19 * Alexey Kuznetsov: Reworked. Really, now it is truncated version of ipv4/ip_gre.c. 20 * I do not want to merge them together. 21 * 22 * This program is free software; you can redistribute it and/or 23 * modify it under the terms of the GNU General Public License 24 * as published by the Free Software Foundation; either version 25 * 2 of the License, or (at your option) any later version. 26 * 27 */ 28 29 /* tunnel.c: an IP tunnel driver 30 31 The purpose of this driver is to provide an IP tunnel through 32 which you can tunnel network traffic transparently across subnets. 33 34 This was written by looking at Nick Holloway's dummy driver 35 Thanks for the great code! 36 37 -Sam Lantinga (slouken@cs.ucdavis.edu) 02/01/95 38 39 Minor tweaks: 40 Cleaned up the code a little and added some pre-1.3.0 tweaks. 41 dev->hard_header/hard_header_len changed to use no headers. 42 Comments/bracketing tweaked. 43 Made the tunnels use dev->name not tunnel: when error reporting. 44 Added tx_dropped stat 45 46 -Alan Cox (Alan.Cox@linux.org) 21 March 95 47 48 Reworked: 49 Changed to tunnel to destination gateway in addition to the 50 tunnel's pointopoint address 51 Almost completely rewritten 52 Note: There is currently no firewall or ICMP handling done. 53 54 -Sam Lantinga (slouken@cs.ucdavis.edu) 02/13/96 55 56 */ 57 58 /* Things I wish I had known when writing the tunnel driver: 59 60 When the tunnel_xmit() function is called, the skb contains the 61 packet to be sent (plus a great deal of extra info), and dev 62 contains the tunnel device that _we_ are. 63 64 When we are passed a packet, we are expected to fill in the 65 source address with our source IP address. 66 67 What is the proper way to allocate, copy and free a buffer? 68 After you allocate it, it is a "0 length" chunk of memory 69 starting at zero. If you want to add headers to the buffer 70 later, you'll have to call "skb_reserve(skb, amount)" with 71 the amount of memory you want reserved. Then, you call 72 "skb_put(skb, amount)" with the amount of space you want in 73 the buffer. skb_put() returns a pointer to the top (#0) of 74 that buffer. skb->len is set to the amount of space you have 75 "allocated" with skb_put(). You can then write up to skb->len 76 bytes to that buffer. If you need more, you can call skb_put() 77 again with the additional amount of space you need. You can 78 find out how much more space you can allocate by calling 79 "skb_tailroom(skb)". 80 Now, to add header space, call "skb_push(skb, header_len)". 81 This creates space at the beginning of the buffer and returns 82 a pointer to this new space. If later you need to strip a 83 header from a buffer, call "skb_pull(skb, header_len)". 84 skb_headroom() will return how much space is left at the top 85 of the buffer (before the main data). Remember, this headroom 86 space must be reserved before the skb_put() function is called. 87 */ 88 89 /* 90 This version of net/ipv4/ipip.c is cloned of net/ipv4/ip_gre.c 91 92 For comments look at net/ipv4/ip_gre.c --ANK 93 */ 94 95 96 #include <linux/capability.h> 97 #include <linux/module.h> 98 #include <linux/types.h> 99 #include <linux/sched.h> 100 #include <linux/kernel.h> 101 #include <asm/uaccess.h> 102 #include <linux/skbuff.h> 103 #include <linux/netdevice.h> 104 #include <linux/in.h> 105 #include <linux/tcp.h> 106 #include <linux/udp.h> 107 #include <linux/if_arp.h> 108 #include <linux/mroute.h> 109 #include <linux/init.h> 110 #include <linux/netfilter_ipv4.h> 111 #include <linux/if_ether.h> 112 113 #include <net/sock.h> 114 #include <net/ip.h> 115 #include <net/icmp.h> 116 #include <net/ipip.h> 117 #include <net/inet_ecn.h> 118 #include <net/xfrm.h> 119 120 #define HASH_SIZE 16 121 #define HASH(addr) ((addr^(addr>>4))&0xF) 122 123 static int ipip_fb_tunnel_init(struct net_device *dev); 124 static int ipip_tunnel_init(struct net_device *dev); 125 static void ipip_tunnel_setup(struct net_device *dev); 126 127 static struct net_device *ipip_fb_tunnel_dev; 128 129 static struct ip_tunnel *tunnels_r_l[HASH_SIZE]; 130 static struct ip_tunnel *tunnels_r[HASH_SIZE]; 131 static struct ip_tunnel *tunnels_l[HASH_SIZE]; 132 static struct ip_tunnel *tunnels_wc[1]; 133 static struct ip_tunnel **tunnels[4] = { tunnels_wc, tunnels_l, tunnels_r, tunnels_r_l }; 134 135 static DEFINE_RWLOCK(ipip_lock); 136 137 static struct ip_tunnel * ipip_tunnel_lookup(u32 remote, u32 local) 138 { 139 unsigned h0 = HASH(remote); 140 unsigned h1 = HASH(local); 141 struct ip_tunnel *t; 142 143 for (t = tunnels_r_l[h0^h1]; t; t = t->next) { 144 if (local == t->parms.iph.saddr && 145 remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP)) 146 return t; 147 } 148 for (t = tunnels_r[h0]; t; t = t->next) { 149 if (remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP)) 150 return t; 151 } 152 for (t = tunnels_l[h1]; t; t = t->next) { 153 if (local == t->parms.iph.saddr && (t->dev->flags&IFF_UP)) 154 return t; 155 } 156 if ((t = tunnels_wc[0]) != NULL && (t->dev->flags&IFF_UP)) 157 return t; 158 return NULL; 159 } 160 161 static struct ip_tunnel **ipip_bucket(struct ip_tunnel *t) 162 { 163 u32 remote = t->parms.iph.daddr; 164 u32 local = t->parms.iph.saddr; 165 unsigned h = 0; 166 int prio = 0; 167 168 if (remote) { 169 prio |= 2; 170 h ^= HASH(remote); 171 } 172 if (local) { 173 prio |= 1; 174 h ^= HASH(local); 175 } 176 return &tunnels[prio][h]; 177 } 178 179 180 static void ipip_tunnel_unlink(struct ip_tunnel *t) 181 { 182 struct ip_tunnel **tp; 183 184 for (tp = ipip_bucket(t); *tp; tp = &(*tp)->next) { 185 if (t == *tp) { 186 write_lock_bh(&ipip_lock); 187 *tp = t->next; 188 write_unlock_bh(&ipip_lock); 189 break; 190 } 191 } 192 } 193 194 static void ipip_tunnel_link(struct ip_tunnel *t) 195 { 196 struct ip_tunnel **tp = ipip_bucket(t); 197 198 t->next = *tp; 199 write_lock_bh(&ipip_lock); 200 *tp = t; 201 write_unlock_bh(&ipip_lock); 202 } 203 204 static struct ip_tunnel * ipip_tunnel_locate(struct ip_tunnel_parm *parms, int create) 205 { 206 u32 remote = parms->iph.daddr; 207 u32 local = parms->iph.saddr; 208 struct ip_tunnel *t, **tp, *nt; 209 struct net_device *dev; 210 unsigned h = 0; 211 int prio = 0; 212 char name[IFNAMSIZ]; 213 214 if (remote) { 215 prio |= 2; 216 h ^= HASH(remote); 217 } 218 if (local) { 219 prio |= 1; 220 h ^= HASH(local); 221 } 222 for (tp = &tunnels[prio][h]; (t = *tp) != NULL; tp = &t->next) { 223 if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr) 224 return t; 225 } 226 if (!create) 227 return NULL; 228 229 if (parms->name[0]) 230 strlcpy(name, parms->name, IFNAMSIZ); 231 else { 232 int i; 233 for (i=1; i<100; i++) { 234 sprintf(name, "tunl%d", i); 235 if (__dev_get_by_name(name) == NULL) 236 break; 237 } 238 if (i==100) 239 goto failed; 240 } 241 242 dev = alloc_netdev(sizeof(*t), name, ipip_tunnel_setup); 243 if (dev == NULL) 244 return NULL; 245 246 nt = netdev_priv(dev); 247 SET_MODULE_OWNER(dev); 248 dev->init = ipip_tunnel_init; 249 nt->parms = *parms; 250 251 if (register_netdevice(dev) < 0) { 252 free_netdev(dev); 253 goto failed; 254 } 255 256 dev_hold(dev); 257 ipip_tunnel_link(nt); 258 return nt; 259 260 failed: 261 return NULL; 262 } 263 264 static void ipip_tunnel_uninit(struct net_device *dev) 265 { 266 if (dev == ipip_fb_tunnel_dev) { 267 write_lock_bh(&ipip_lock); 268 tunnels_wc[0] = NULL; 269 write_unlock_bh(&ipip_lock); 270 } else 271 ipip_tunnel_unlink(netdev_priv(dev)); 272 dev_put(dev); 273 } 274 275 static int ipip_err(struct sk_buff *skb, u32 info) 276 { 277 #ifndef I_WISH_WORLD_WERE_PERFECT 278 279 /* It is not :-( All the routers (except for Linux) return only 280 8 bytes of packet payload. It means, that precise relaying of 281 ICMP in the real Internet is absolutely infeasible. 282 */ 283 struct iphdr *iph = (struct iphdr*)skb->data; 284 int type = skb->h.icmph->type; 285 int code = skb->h.icmph->code; 286 struct ip_tunnel *t; 287 int err; 288 289 switch (type) { 290 default: 291 case ICMP_PARAMETERPROB: 292 return 0; 293 294 case ICMP_DEST_UNREACH: 295 switch (code) { 296 case ICMP_SR_FAILED: 297 case ICMP_PORT_UNREACH: 298 /* Impossible event. */ 299 return 0; 300 case ICMP_FRAG_NEEDED: 301 /* Soft state for pmtu is maintained by IP core. */ 302 return 0; 303 default: 304 /* All others are translated to HOST_UNREACH. 305 rfc2003 contains "deep thoughts" about NET_UNREACH, 306 I believe they are just ether pollution. --ANK 307 */ 308 break; 309 } 310 break; 311 case ICMP_TIME_EXCEEDED: 312 if (code != ICMP_EXC_TTL) 313 return 0; 314 break; 315 } 316 317 err = -ENOENT; 318 319 read_lock(&ipip_lock); 320 t = ipip_tunnel_lookup(iph->daddr, iph->saddr); 321 if (t == NULL || t->parms.iph.daddr == 0) 322 goto out; 323 324 err = 0; 325 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 326 goto out; 327 328 if (jiffies - t->err_time < IPTUNNEL_ERR_TIMEO) 329 t->err_count++; 330 else 331 t->err_count = 1; 332 t->err_time = jiffies; 333 out: 334 read_unlock(&ipip_lock); 335 return err; 336 #else 337 struct iphdr *iph = (struct iphdr*)dp; 338 int hlen = iph->ihl<<2; 339 struct iphdr *eiph; 340 int type = skb->h.icmph->type; 341 int code = skb->h.icmph->code; 342 int rel_type = 0; 343 int rel_code = 0; 344 int rel_info = 0; 345 struct sk_buff *skb2; 346 struct flowi fl; 347 struct rtable *rt; 348 349 if (len < hlen + sizeof(struct iphdr)) 350 return 0; 351 eiph = (struct iphdr*)(dp + hlen); 352 353 switch (type) { 354 default: 355 return 0; 356 case ICMP_PARAMETERPROB: 357 if (skb->h.icmph->un.gateway < hlen) 358 return 0; 359 360 /* So... This guy found something strange INSIDE encapsulated 361 packet. Well, he is fool, but what can we do ? 362 */ 363 rel_type = ICMP_PARAMETERPROB; 364 rel_info = skb->h.icmph->un.gateway - hlen; 365 break; 366 367 case ICMP_DEST_UNREACH: 368 switch (code) { 369 case ICMP_SR_FAILED: 370 case ICMP_PORT_UNREACH: 371 /* Impossible event. */ 372 return 0; 373 case ICMP_FRAG_NEEDED: 374 /* And it is the only really necessary thing :-) */ 375 rel_info = ntohs(skb->h.icmph->un.frag.mtu); 376 if (rel_info < hlen+68) 377 return 0; 378 rel_info -= hlen; 379 /* BSD 4.2 MORE DOES NOT EXIST IN NATURE. */ 380 if (rel_info > ntohs(eiph->tot_len)) 381 return 0; 382 break; 383 default: 384 /* All others are translated to HOST_UNREACH. 385 rfc2003 contains "deep thoughts" about NET_UNREACH, 386 I believe, it is just ether pollution. --ANK 387 */ 388 rel_type = ICMP_DEST_UNREACH; 389 rel_code = ICMP_HOST_UNREACH; 390 break; 391 } 392 break; 393 case ICMP_TIME_EXCEEDED: 394 if (code != ICMP_EXC_TTL) 395 return 0; 396 break; 397 } 398 399 /* Prepare fake skb to feed it to icmp_send */ 400 skb2 = skb_clone(skb, GFP_ATOMIC); 401 if (skb2 == NULL) 402 return 0; 403 dst_release(skb2->dst); 404 skb2->dst = NULL; 405 skb_pull(skb2, skb->data - (u8*)eiph); 406 skb2->nh.raw = skb2->data; 407 408 /* Try to guess incoming interface */ 409 memset(&fl, 0, sizeof(fl)); 410 fl.fl4_daddr = eiph->saddr; 411 fl.fl4_tos = RT_TOS(eiph->tos); 412 fl.proto = IPPROTO_IPIP; 413 if (ip_route_output_key(&rt, &key)) { 414 kfree_skb(skb2); 415 return 0; 416 } 417 skb2->dev = rt->u.dst.dev; 418 419 /* route "incoming" packet */ 420 if (rt->rt_flags&RTCF_LOCAL) { 421 ip_rt_put(rt); 422 rt = NULL; 423 fl.fl4_daddr = eiph->daddr; 424 fl.fl4_src = eiph->saddr; 425 fl.fl4_tos = eiph->tos; 426 if (ip_route_output_key(&rt, &fl) || 427 rt->u.dst.dev->type != ARPHRD_TUNNEL) { 428 ip_rt_put(rt); 429 kfree_skb(skb2); 430 return 0; 431 } 432 } else { 433 ip_rt_put(rt); 434 if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos, skb2->dev) || 435 skb2->dst->dev->type != ARPHRD_TUNNEL) { 436 kfree_skb(skb2); 437 return 0; 438 } 439 } 440 441 /* change mtu on this route */ 442 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { 443 if (rel_info > dst_mtu(skb2->dst)) { 444 kfree_skb(skb2); 445 return 0; 446 } 447 skb2->dst->ops->update_pmtu(skb2->dst, rel_info); 448 rel_info = htonl(rel_info); 449 } else if (type == ICMP_TIME_EXCEEDED) { 450 struct ip_tunnel *t = netdev_priv(skb2->dev); 451 if (t->parms.iph.ttl) { 452 rel_type = ICMP_DEST_UNREACH; 453 rel_code = ICMP_HOST_UNREACH; 454 } 455 } 456 457 icmp_send(skb2, rel_type, rel_code, rel_info); 458 kfree_skb(skb2); 459 return 0; 460 #endif 461 } 462 463 static inline void ipip_ecn_decapsulate(struct iphdr *outer_iph, struct sk_buff *skb) 464 { 465 struct iphdr *inner_iph = skb->nh.iph; 466 467 if (INET_ECN_is_ce(outer_iph->tos)) 468 IP_ECN_set_ce(inner_iph); 469 } 470 471 static int ipip_rcv(struct sk_buff *skb) 472 { 473 struct iphdr *iph; 474 struct ip_tunnel *tunnel; 475 476 iph = skb->nh.iph; 477 478 read_lock(&ipip_lock); 479 if ((tunnel = ipip_tunnel_lookup(iph->saddr, iph->daddr)) != NULL) { 480 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { 481 read_unlock(&ipip_lock); 482 kfree_skb(skb); 483 return 0; 484 } 485 486 secpath_reset(skb); 487 488 skb->mac.raw = skb->nh.raw; 489 skb->nh.raw = skb->data; 490 skb->protocol = htons(ETH_P_IP); 491 skb->pkt_type = PACKET_HOST; 492 493 tunnel->stat.rx_packets++; 494 tunnel->stat.rx_bytes += skb->len; 495 skb->dev = tunnel->dev; 496 dst_release(skb->dst); 497 skb->dst = NULL; 498 nf_reset(skb); 499 ipip_ecn_decapsulate(iph, skb); 500 netif_rx(skb); 501 read_unlock(&ipip_lock); 502 return 0; 503 } 504 read_unlock(&ipip_lock); 505 506 return -1; 507 } 508 509 /* 510 * This function assumes it is being called from dev_queue_xmit() 511 * and that skb is filled properly by that function. 512 */ 513 514 static int ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) 515 { 516 struct ip_tunnel *tunnel = netdev_priv(dev); 517 struct net_device_stats *stats = &tunnel->stat; 518 struct iphdr *tiph = &tunnel->parms.iph; 519 u8 tos = tunnel->parms.iph.tos; 520 u16 df = tiph->frag_off; 521 struct rtable *rt; /* Route to the other host */ 522 struct net_device *tdev; /* Device to other host */ 523 struct iphdr *old_iph = skb->nh.iph; 524 struct iphdr *iph; /* Our new IP header */ 525 int max_headroom; /* The extra header space needed */ 526 u32 dst = tiph->daddr; 527 int mtu; 528 529 if (tunnel->recursion++) { 530 tunnel->stat.collisions++; 531 goto tx_error; 532 } 533 534 if (skb->protocol != htons(ETH_P_IP)) 535 goto tx_error; 536 537 if (tos&1) 538 tos = old_iph->tos; 539 540 if (!dst) { 541 /* NBMA tunnel */ 542 if ((rt = (struct rtable*)skb->dst) == NULL) { 543 tunnel->stat.tx_fifo_errors++; 544 goto tx_error; 545 } 546 if ((dst = rt->rt_gateway) == 0) 547 goto tx_error_icmp; 548 } 549 550 { 551 struct flowi fl = { .oif = tunnel->parms.link, 552 .nl_u = { .ip4_u = 553 { .daddr = dst, 554 .saddr = tiph->saddr, 555 .tos = RT_TOS(tos) } }, 556 .proto = IPPROTO_IPIP }; 557 if (ip_route_output_key(&rt, &fl)) { 558 tunnel->stat.tx_carrier_errors++; 559 goto tx_error_icmp; 560 } 561 } 562 tdev = rt->u.dst.dev; 563 564 if (tdev == dev) { 565 ip_rt_put(rt); 566 tunnel->stat.collisions++; 567 goto tx_error; 568 } 569 570 if (tiph->frag_off) 571 mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr); 572 else 573 mtu = skb->dst ? dst_mtu(skb->dst) : dev->mtu; 574 575 if (mtu < 68) { 576 tunnel->stat.collisions++; 577 ip_rt_put(rt); 578 goto tx_error; 579 } 580 if (skb->dst) 581 skb->dst->ops->update_pmtu(skb->dst, mtu); 582 583 df |= (old_iph->frag_off&htons(IP_DF)); 584 585 if ((old_iph->frag_off&htons(IP_DF)) && mtu < ntohs(old_iph->tot_len)) { 586 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu)); 587 ip_rt_put(rt); 588 goto tx_error; 589 } 590 591 if (tunnel->err_count > 0) { 592 if (jiffies - tunnel->err_time < IPTUNNEL_ERR_TIMEO) { 593 tunnel->err_count--; 594 dst_link_failure(skb); 595 } else 596 tunnel->err_count = 0; 597 } 598 599 /* 600 * Okay, now see if we can stuff it in the buffer as-is. 601 */ 602 max_headroom = (LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr)); 603 604 if (skb_headroom(skb) < max_headroom || skb_cloned(skb) || skb_shared(skb)) { 605 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); 606 if (!new_skb) { 607 ip_rt_put(rt); 608 stats->tx_dropped++; 609 dev_kfree_skb(skb); 610 tunnel->recursion--; 611 return 0; 612 } 613 if (skb->sk) 614 skb_set_owner_w(new_skb, skb->sk); 615 dev_kfree_skb(skb); 616 skb = new_skb; 617 old_iph = skb->nh.iph; 618 } 619 620 skb->h.raw = skb->nh.raw; 621 skb->nh.raw = skb_push(skb, sizeof(struct iphdr)); 622 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); 623 IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | 624 IPSKB_REROUTED); 625 dst_release(skb->dst); 626 skb->dst = &rt->u.dst; 627 628 /* 629 * Push down and install the IPIP header. 630 */ 631 632 iph = skb->nh.iph; 633 iph->version = 4; 634 iph->ihl = sizeof(struct iphdr)>>2; 635 iph->frag_off = df; 636 iph->protocol = IPPROTO_IPIP; 637 iph->tos = INET_ECN_encapsulate(tos, old_iph->tos); 638 iph->daddr = rt->rt_dst; 639 iph->saddr = rt->rt_src; 640 641 if ((iph->ttl = tiph->ttl) == 0) 642 iph->ttl = old_iph->ttl; 643 644 nf_reset(skb); 645 646 IPTUNNEL_XMIT(); 647 tunnel->recursion--; 648 return 0; 649 650 tx_error_icmp: 651 dst_link_failure(skb); 652 tx_error: 653 stats->tx_errors++; 654 dev_kfree_skb(skb); 655 tunnel->recursion--; 656 return 0; 657 } 658 659 static int 660 ipip_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) 661 { 662 int err = 0; 663 struct ip_tunnel_parm p; 664 struct ip_tunnel *t; 665 666 switch (cmd) { 667 case SIOCGETTUNNEL: 668 t = NULL; 669 if (dev == ipip_fb_tunnel_dev) { 670 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 671 err = -EFAULT; 672 break; 673 } 674 t = ipip_tunnel_locate(&p, 0); 675 } 676 if (t == NULL) 677 t = netdev_priv(dev); 678 memcpy(&p, &t->parms, sizeof(p)); 679 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 680 err = -EFAULT; 681 break; 682 683 case SIOCADDTUNNEL: 684 case SIOCCHGTUNNEL: 685 err = -EPERM; 686 if (!capable(CAP_NET_ADMIN)) 687 goto done; 688 689 err = -EFAULT; 690 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 691 goto done; 692 693 err = -EINVAL; 694 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP || 695 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) 696 goto done; 697 if (p.iph.ttl) 698 p.iph.frag_off |= htons(IP_DF); 699 700 t = ipip_tunnel_locate(&p, cmd == SIOCADDTUNNEL); 701 702 if (dev != ipip_fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 703 if (t != NULL) { 704 if (t->dev != dev) { 705 err = -EEXIST; 706 break; 707 } 708 } else { 709 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || 710 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { 711 err = -EINVAL; 712 break; 713 } 714 t = netdev_priv(dev); 715 ipip_tunnel_unlink(t); 716 t->parms.iph.saddr = p.iph.saddr; 717 t->parms.iph.daddr = p.iph.daddr; 718 memcpy(dev->dev_addr, &p.iph.saddr, 4); 719 memcpy(dev->broadcast, &p.iph.daddr, 4); 720 ipip_tunnel_link(t); 721 netdev_state_change(dev); 722 } 723 } 724 725 if (t) { 726 err = 0; 727 if (cmd == SIOCCHGTUNNEL) { 728 t->parms.iph.ttl = p.iph.ttl; 729 t->parms.iph.tos = p.iph.tos; 730 t->parms.iph.frag_off = p.iph.frag_off; 731 } 732 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) 733 err = -EFAULT; 734 } else 735 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 736 break; 737 738 case SIOCDELTUNNEL: 739 err = -EPERM; 740 if (!capable(CAP_NET_ADMIN)) 741 goto done; 742 743 if (dev == ipip_fb_tunnel_dev) { 744 err = -EFAULT; 745 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 746 goto done; 747 err = -ENOENT; 748 if ((t = ipip_tunnel_locate(&p, 0)) == NULL) 749 goto done; 750 err = -EPERM; 751 if (t->dev == ipip_fb_tunnel_dev) 752 goto done; 753 dev = t->dev; 754 } 755 err = unregister_netdevice(dev); 756 break; 757 758 default: 759 err = -EINVAL; 760 } 761 762 done: 763 return err; 764 } 765 766 static struct net_device_stats *ipip_tunnel_get_stats(struct net_device *dev) 767 { 768 return &(((struct ip_tunnel*)netdev_priv(dev))->stat); 769 } 770 771 static int ipip_tunnel_change_mtu(struct net_device *dev, int new_mtu) 772 { 773 if (new_mtu < 68 || new_mtu > 0xFFF8 - sizeof(struct iphdr)) 774 return -EINVAL; 775 dev->mtu = new_mtu; 776 return 0; 777 } 778 779 static void ipip_tunnel_setup(struct net_device *dev) 780 { 781 SET_MODULE_OWNER(dev); 782 dev->uninit = ipip_tunnel_uninit; 783 dev->hard_start_xmit = ipip_tunnel_xmit; 784 dev->get_stats = ipip_tunnel_get_stats; 785 dev->do_ioctl = ipip_tunnel_ioctl; 786 dev->change_mtu = ipip_tunnel_change_mtu; 787 dev->destructor = free_netdev; 788 789 dev->type = ARPHRD_TUNNEL; 790 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); 791 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr); 792 dev->flags = IFF_NOARP; 793 dev->iflink = 0; 794 dev->addr_len = 4; 795 } 796 797 static int ipip_tunnel_init(struct net_device *dev) 798 { 799 struct net_device *tdev = NULL; 800 struct ip_tunnel *tunnel; 801 struct iphdr *iph; 802 803 tunnel = netdev_priv(dev); 804 iph = &tunnel->parms.iph; 805 806 tunnel->dev = dev; 807 strcpy(tunnel->parms.name, dev->name); 808 809 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); 810 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); 811 812 if (iph->daddr) { 813 struct flowi fl = { .oif = tunnel->parms.link, 814 .nl_u = { .ip4_u = 815 { .daddr = iph->daddr, 816 .saddr = iph->saddr, 817 .tos = RT_TOS(iph->tos) } }, 818 .proto = IPPROTO_IPIP }; 819 struct rtable *rt; 820 if (!ip_route_output_key(&rt, &fl)) { 821 tdev = rt->u.dst.dev; 822 ip_rt_put(rt); 823 } 824 dev->flags |= IFF_POINTOPOINT; 825 } 826 827 if (!tdev && tunnel->parms.link) 828 tdev = __dev_get_by_index(tunnel->parms.link); 829 830 if (tdev) { 831 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); 832 dev->mtu = tdev->mtu - sizeof(struct iphdr); 833 } 834 dev->iflink = tunnel->parms.link; 835 836 return 0; 837 } 838 839 static int __init ipip_fb_tunnel_init(struct net_device *dev) 840 { 841 struct ip_tunnel *tunnel = netdev_priv(dev); 842 struct iphdr *iph = &tunnel->parms.iph; 843 844 tunnel->dev = dev; 845 strcpy(tunnel->parms.name, dev->name); 846 847 iph->version = 4; 848 iph->protocol = IPPROTO_IPIP; 849 iph->ihl = 5; 850 851 dev_hold(dev); 852 tunnels_wc[0] = tunnel; 853 return 0; 854 } 855 856 static struct xfrm_tunnel ipip_handler = { 857 .handler = ipip_rcv, 858 .err_handler = ipip_err, 859 .priority = 1, 860 }; 861 862 static char banner[] __initdata = 863 KERN_INFO "IPv4 over IPv4 tunneling driver\n"; 864 865 static int __init ipip_init(void) 866 { 867 int err; 868 869 printk(banner); 870 871 if (xfrm4_tunnel_register(&ipip_handler)) { 872 printk(KERN_INFO "ipip init: can't register tunnel\n"); 873 return -EAGAIN; 874 } 875 876 ipip_fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), 877 "tunl0", 878 ipip_tunnel_setup); 879 if (!ipip_fb_tunnel_dev) { 880 err = -ENOMEM; 881 goto err1; 882 } 883 884 ipip_fb_tunnel_dev->init = ipip_fb_tunnel_init; 885 886 if ((err = register_netdev(ipip_fb_tunnel_dev))) 887 goto err2; 888 out: 889 return err; 890 err2: 891 free_netdev(ipip_fb_tunnel_dev); 892 err1: 893 xfrm4_tunnel_deregister(&ipip_handler); 894 goto out; 895 } 896 897 static void __exit ipip_destroy_tunnels(void) 898 { 899 int prio; 900 901 for (prio = 1; prio < 4; prio++) { 902 int h; 903 for (h = 0; h < HASH_SIZE; h++) { 904 struct ip_tunnel *t; 905 while ((t = tunnels[prio][h]) != NULL) 906 unregister_netdevice(t->dev); 907 } 908 } 909 } 910 911 static void __exit ipip_fini(void) 912 { 913 if (xfrm4_tunnel_deregister(&ipip_handler)) 914 printk(KERN_INFO "ipip close: can't deregister tunnel\n"); 915 916 rtnl_lock(); 917 ipip_destroy_tunnels(); 918 unregister_netdevice(ipip_fb_tunnel_dev); 919 rtnl_unlock(); 920 } 921 922 module_init(ipip_init); 923 module_exit(ipip_fini); 924 MODULE_LICENSE("GPL"); 925