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/config.h> 98 #include <linux/module.h> 99 #include <linux/types.h> 100 #include <linux/sched.h> 101 #include <linux/kernel.h> 102 #include <asm/uaccess.h> 103 #include <linux/skbuff.h> 104 #include <linux/netdevice.h> 105 #include <linux/in.h> 106 #include <linux/tcp.h> 107 #include <linux/udp.h> 108 #include <linux/if_arp.h> 109 #include <linux/mroute.h> 110 #include <linux/init.h> 111 #include <linux/netfilter_ipv4.h> 112 #include <linux/if_ether.h> 113 114 #include <net/sock.h> 115 #include <net/ip.h> 116 #include <net/icmp.h> 117 #include <net/protocol.h> 118 #include <net/ipip.h> 119 #include <net/inet_ecn.h> 120 #include <net/xfrm.h> 121 122 #define HASH_SIZE 16 123 #define HASH(addr) ((addr^(addr>>4))&0xF) 124 125 static int ipip_fb_tunnel_init(struct net_device *dev); 126 static int ipip_tunnel_init(struct net_device *dev); 127 static void ipip_tunnel_setup(struct net_device *dev); 128 129 static struct net_device *ipip_fb_tunnel_dev; 130 131 static struct ip_tunnel *tunnels_r_l[HASH_SIZE]; 132 static struct ip_tunnel *tunnels_r[HASH_SIZE]; 133 static struct ip_tunnel *tunnels_l[HASH_SIZE]; 134 static struct ip_tunnel *tunnels_wc[1]; 135 static struct ip_tunnel **tunnels[4] = { tunnels_wc, tunnels_l, tunnels_r, tunnels_r_l }; 136 137 static DEFINE_RWLOCK(ipip_lock); 138 139 static struct ip_tunnel * ipip_tunnel_lookup(u32 remote, u32 local) 140 { 141 unsigned h0 = HASH(remote); 142 unsigned h1 = HASH(local); 143 struct ip_tunnel *t; 144 145 for (t = tunnels_r_l[h0^h1]; t; t = t->next) { 146 if (local == t->parms.iph.saddr && 147 remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP)) 148 return t; 149 } 150 for (t = tunnels_r[h0]; t; t = t->next) { 151 if (remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP)) 152 return t; 153 } 154 for (t = tunnels_l[h1]; t; t = t->next) { 155 if (local == t->parms.iph.saddr && (t->dev->flags&IFF_UP)) 156 return t; 157 } 158 if ((t = tunnels_wc[0]) != NULL && (t->dev->flags&IFF_UP)) 159 return t; 160 return NULL; 161 } 162 163 static struct ip_tunnel **ipip_bucket(struct ip_tunnel *t) 164 { 165 u32 remote = t->parms.iph.daddr; 166 u32 local = t->parms.iph.saddr; 167 unsigned h = 0; 168 int prio = 0; 169 170 if (remote) { 171 prio |= 2; 172 h ^= HASH(remote); 173 } 174 if (local) { 175 prio |= 1; 176 h ^= HASH(local); 177 } 178 return &tunnels[prio][h]; 179 } 180 181 182 static void ipip_tunnel_unlink(struct ip_tunnel *t) 183 { 184 struct ip_tunnel **tp; 185 186 for (tp = ipip_bucket(t); *tp; tp = &(*tp)->next) { 187 if (t == *tp) { 188 write_lock_bh(&ipip_lock); 189 *tp = t->next; 190 write_unlock_bh(&ipip_lock); 191 break; 192 } 193 } 194 } 195 196 static void ipip_tunnel_link(struct ip_tunnel *t) 197 { 198 struct ip_tunnel **tp = ipip_bucket(t); 199 200 t->next = *tp; 201 write_lock_bh(&ipip_lock); 202 *tp = t; 203 write_unlock_bh(&ipip_lock); 204 } 205 206 static struct ip_tunnel * ipip_tunnel_locate(struct ip_tunnel_parm *parms, int create) 207 { 208 u32 remote = parms->iph.daddr; 209 u32 local = parms->iph.saddr; 210 struct ip_tunnel *t, **tp, *nt; 211 struct net_device *dev; 212 unsigned h = 0; 213 int prio = 0; 214 char name[IFNAMSIZ]; 215 216 if (remote) { 217 prio |= 2; 218 h ^= HASH(remote); 219 } 220 if (local) { 221 prio |= 1; 222 h ^= HASH(local); 223 } 224 for (tp = &tunnels[prio][h]; (t = *tp) != NULL; tp = &t->next) { 225 if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr) 226 return t; 227 } 228 if (!create) 229 return NULL; 230 231 if (parms->name[0]) 232 strlcpy(name, parms->name, IFNAMSIZ); 233 else { 234 int i; 235 for (i=1; i<100; i++) { 236 sprintf(name, "tunl%d", i); 237 if (__dev_get_by_name(name) == NULL) 238 break; 239 } 240 if (i==100) 241 goto failed; 242 } 243 244 dev = alloc_netdev(sizeof(*t), name, ipip_tunnel_setup); 245 if (dev == NULL) 246 return NULL; 247 248 nt = netdev_priv(dev); 249 SET_MODULE_OWNER(dev); 250 dev->init = ipip_tunnel_init; 251 nt->parms = *parms; 252 253 if (register_netdevice(dev) < 0) { 254 free_netdev(dev); 255 goto failed; 256 } 257 258 dev_hold(dev); 259 ipip_tunnel_link(nt); 260 return nt; 261 262 failed: 263 return NULL; 264 } 265 266 static void ipip_tunnel_uninit(struct net_device *dev) 267 { 268 if (dev == ipip_fb_tunnel_dev) { 269 write_lock_bh(&ipip_lock); 270 tunnels_wc[0] = NULL; 271 write_unlock_bh(&ipip_lock); 272 } else 273 ipip_tunnel_unlink(netdev_priv(dev)); 274 dev_put(dev); 275 } 276 277 static void ipip_err(struct sk_buff *skb, u32 info) 278 { 279 #ifndef I_WISH_WORLD_WERE_PERFECT 280 281 /* It is not :-( All the routers (except for Linux) return only 282 8 bytes of packet payload. It means, that precise relaying of 283 ICMP in the real Internet is absolutely infeasible. 284 */ 285 struct iphdr *iph = (struct iphdr*)skb->data; 286 int type = skb->h.icmph->type; 287 int code = skb->h.icmph->code; 288 struct ip_tunnel *t; 289 290 switch (type) { 291 default: 292 case ICMP_PARAMETERPROB: 293 return; 294 295 case ICMP_DEST_UNREACH: 296 switch (code) { 297 case ICMP_SR_FAILED: 298 case ICMP_PORT_UNREACH: 299 /* Impossible event. */ 300 return; 301 case ICMP_FRAG_NEEDED: 302 /* Soft state for pmtu is maintained by IP core. */ 303 return; 304 default: 305 /* All others are translated to HOST_UNREACH. 306 rfc2003 contains "deep thoughts" about NET_UNREACH, 307 I believe they are just ether pollution. --ANK 308 */ 309 break; 310 } 311 break; 312 case ICMP_TIME_EXCEEDED: 313 if (code != ICMP_EXC_TTL) 314 return; 315 break; 316 } 317 318 read_lock(&ipip_lock); 319 t = ipip_tunnel_lookup(iph->daddr, iph->saddr); 320 if (t == NULL || t->parms.iph.daddr == 0) 321 goto out; 322 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 323 goto out; 324 325 if (jiffies - t->err_time < IPTUNNEL_ERR_TIMEO) 326 t->err_count++; 327 else 328 t->err_count = 1; 329 t->err_time = jiffies; 330 out: 331 read_unlock(&ipip_lock); 332 return; 333 #else 334 struct iphdr *iph = (struct iphdr*)dp; 335 int hlen = iph->ihl<<2; 336 struct iphdr *eiph; 337 int type = skb->h.icmph->type; 338 int code = skb->h.icmph->code; 339 int rel_type = 0; 340 int rel_code = 0; 341 int rel_info = 0; 342 struct sk_buff *skb2; 343 struct flowi fl; 344 struct rtable *rt; 345 346 if (len < hlen + sizeof(struct iphdr)) 347 return; 348 eiph = (struct iphdr*)(dp + hlen); 349 350 switch (type) { 351 default: 352 return; 353 case ICMP_PARAMETERPROB: 354 if (skb->h.icmph->un.gateway < hlen) 355 return; 356 357 /* So... This guy found something strange INSIDE encapsulated 358 packet. Well, he is fool, but what can we do ? 359 */ 360 rel_type = ICMP_PARAMETERPROB; 361 rel_info = skb->h.icmph->un.gateway - hlen; 362 break; 363 364 case ICMP_DEST_UNREACH: 365 switch (code) { 366 case ICMP_SR_FAILED: 367 case ICMP_PORT_UNREACH: 368 /* Impossible event. */ 369 return; 370 case ICMP_FRAG_NEEDED: 371 /* And it is the only really necessary thing :-) */ 372 rel_info = ntohs(skb->h.icmph->un.frag.mtu); 373 if (rel_info < hlen+68) 374 return; 375 rel_info -= hlen; 376 /* BSD 4.2 MORE DOES NOT EXIST IN NATURE. */ 377 if (rel_info > ntohs(eiph->tot_len)) 378 return; 379 break; 380 default: 381 /* All others are translated to HOST_UNREACH. 382 rfc2003 contains "deep thoughts" about NET_UNREACH, 383 I believe, it is just ether pollution. --ANK 384 */ 385 rel_type = ICMP_DEST_UNREACH; 386 rel_code = ICMP_HOST_UNREACH; 387 break; 388 } 389 break; 390 case ICMP_TIME_EXCEEDED: 391 if (code != ICMP_EXC_TTL) 392 return; 393 break; 394 } 395 396 /* Prepare fake skb to feed it to icmp_send */ 397 skb2 = skb_clone(skb, GFP_ATOMIC); 398 if (skb2 == NULL) 399 return; 400 dst_release(skb2->dst); 401 skb2->dst = NULL; 402 skb_pull(skb2, skb->data - (u8*)eiph); 403 skb2->nh.raw = skb2->data; 404 405 /* Try to guess incoming interface */ 406 memset(&fl, 0, sizeof(fl)); 407 fl.fl4_daddr = eiph->saddr; 408 fl.fl4_tos = RT_TOS(eiph->tos); 409 fl.proto = IPPROTO_IPIP; 410 if (ip_route_output_key(&rt, &key)) { 411 kfree_skb(skb2); 412 return; 413 } 414 skb2->dev = rt->u.dst.dev; 415 416 /* route "incoming" packet */ 417 if (rt->rt_flags&RTCF_LOCAL) { 418 ip_rt_put(rt); 419 rt = NULL; 420 fl.fl4_daddr = eiph->daddr; 421 fl.fl4_src = eiph->saddr; 422 fl.fl4_tos = eiph->tos; 423 if (ip_route_output_key(&rt, &fl) || 424 rt->u.dst.dev->type != ARPHRD_TUNNEL) { 425 ip_rt_put(rt); 426 kfree_skb(skb2); 427 return; 428 } 429 } else { 430 ip_rt_put(rt); 431 if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos, skb2->dev) || 432 skb2->dst->dev->type != ARPHRD_TUNNEL) { 433 kfree_skb(skb2); 434 return; 435 } 436 } 437 438 /* change mtu on this route */ 439 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { 440 if (rel_info > dst_mtu(skb2->dst)) { 441 kfree_skb(skb2); 442 return; 443 } 444 skb2->dst->ops->update_pmtu(skb2->dst, rel_info); 445 rel_info = htonl(rel_info); 446 } else if (type == ICMP_TIME_EXCEEDED) { 447 struct ip_tunnel *t = netdev_priv(skb2->dev); 448 if (t->parms.iph.ttl) { 449 rel_type = ICMP_DEST_UNREACH; 450 rel_code = ICMP_HOST_UNREACH; 451 } 452 } 453 454 icmp_send(skb2, rel_type, rel_code, rel_info); 455 kfree_skb(skb2); 456 return; 457 #endif 458 } 459 460 static inline void ipip_ecn_decapsulate(struct iphdr *outer_iph, struct sk_buff *skb) 461 { 462 struct iphdr *inner_iph = skb->nh.iph; 463 464 if (INET_ECN_is_ce(outer_iph->tos)) 465 IP_ECN_set_ce(inner_iph); 466 } 467 468 static int ipip_rcv(struct sk_buff *skb) 469 { 470 struct iphdr *iph; 471 struct ip_tunnel *tunnel; 472 473 if (!pskb_may_pull(skb, sizeof(struct iphdr))) 474 goto out; 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 memset(&(IPCB(skb)->opt), 0, sizeof(struct ip_options)); 491 skb->protocol = htons(ETH_P_IP); 492 skb->pkt_type = PACKET_HOST; 493 494 tunnel->stat.rx_packets++; 495 tunnel->stat.rx_bytes += skb->len; 496 skb->dev = tunnel->dev; 497 dst_release(skb->dst); 498 skb->dst = NULL; 499 nf_reset(skb); 500 ipip_ecn_decapsulate(iph, skb); 501 netif_rx(skb); 502 read_unlock(&ipip_lock); 503 return 0; 504 } 505 read_unlock(&ipip_lock); 506 507 out: 508 return -1; 509 } 510 511 /* 512 * This function assumes it is being called from dev_queue_xmit() 513 * and that skb is filled properly by that function. 514 */ 515 516 static int ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) 517 { 518 struct ip_tunnel *tunnel = netdev_priv(dev); 519 struct net_device_stats *stats = &tunnel->stat; 520 struct iphdr *tiph = &tunnel->parms.iph; 521 u8 tos = tunnel->parms.iph.tos; 522 u16 df = tiph->frag_off; 523 struct rtable *rt; /* Route to the other host */ 524 struct net_device *tdev; /* Device to other host */ 525 struct iphdr *old_iph = skb->nh.iph; 526 struct iphdr *iph; /* Our new IP header */ 527 int max_headroom; /* The extra header space needed */ 528 u32 dst = tiph->daddr; 529 int mtu; 530 531 if (tunnel->recursion++) { 532 tunnel->stat.collisions++; 533 goto tx_error; 534 } 535 536 if (skb->protocol != htons(ETH_P_IP)) 537 goto tx_error; 538 539 if (tos&1) 540 tos = old_iph->tos; 541 542 if (!dst) { 543 /* NBMA tunnel */ 544 if ((rt = (struct rtable*)skb->dst) == NULL) { 545 tunnel->stat.tx_fifo_errors++; 546 goto tx_error; 547 } 548 if ((dst = rt->rt_gateway) == 0) 549 goto tx_error_icmp; 550 } 551 552 { 553 struct flowi fl = { .oif = tunnel->parms.link, 554 .nl_u = { .ip4_u = 555 { .daddr = dst, 556 .saddr = tiph->saddr, 557 .tos = RT_TOS(tos) } }, 558 .proto = IPPROTO_IPIP }; 559 if (ip_route_output_key(&rt, &fl)) { 560 tunnel->stat.tx_carrier_errors++; 561 goto tx_error_icmp; 562 } 563 } 564 tdev = rt->u.dst.dev; 565 566 if (tdev == dev) { 567 ip_rt_put(rt); 568 tunnel->stat.collisions++; 569 goto tx_error; 570 } 571 572 if (tiph->frag_off) 573 mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr); 574 else 575 mtu = skb->dst ? dst_mtu(skb->dst) : dev->mtu; 576 577 if (mtu < 68) { 578 tunnel->stat.collisions++; 579 ip_rt_put(rt); 580 goto tx_error; 581 } 582 if (skb->dst) 583 skb->dst->ops->update_pmtu(skb->dst, mtu); 584 585 df |= (old_iph->frag_off&htons(IP_DF)); 586 587 if ((old_iph->frag_off&htons(IP_DF)) && mtu < ntohs(old_iph->tot_len)) { 588 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu)); 589 ip_rt_put(rt); 590 goto tx_error; 591 } 592 593 if (tunnel->err_count > 0) { 594 if (jiffies - tunnel->err_time < IPTUNNEL_ERR_TIMEO) { 595 tunnel->err_count--; 596 dst_link_failure(skb); 597 } else 598 tunnel->err_count = 0; 599 } 600 601 /* 602 * Okay, now see if we can stuff it in the buffer as-is. 603 */ 604 max_headroom = (LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr)); 605 606 if (skb_headroom(skb) < max_headroom || skb_cloned(skb) || skb_shared(skb)) { 607 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); 608 if (!new_skb) { 609 ip_rt_put(rt); 610 stats->tx_dropped++; 611 dev_kfree_skb(skb); 612 tunnel->recursion--; 613 return 0; 614 } 615 if (skb->sk) 616 skb_set_owner_w(new_skb, skb->sk); 617 dev_kfree_skb(skb); 618 skb = new_skb; 619 old_iph = skb->nh.iph; 620 } 621 622 skb->h.raw = skb->nh.raw; 623 skb->nh.raw = skb_push(skb, sizeof(struct iphdr)); 624 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); 625 IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | 626 IPSKB_REROUTED); 627 dst_release(skb->dst); 628 skb->dst = &rt->u.dst; 629 630 /* 631 * Push down and install the IPIP header. 632 */ 633 634 iph = skb->nh.iph; 635 iph->version = 4; 636 iph->ihl = sizeof(struct iphdr)>>2; 637 iph->frag_off = df; 638 iph->protocol = IPPROTO_IPIP; 639 iph->tos = INET_ECN_encapsulate(tos, old_iph->tos); 640 iph->daddr = rt->rt_dst; 641 iph->saddr = rt->rt_src; 642 643 if ((iph->ttl = tiph->ttl) == 0) 644 iph->ttl = old_iph->ttl; 645 646 nf_reset(skb); 647 648 IPTUNNEL_XMIT(); 649 tunnel->recursion--; 650 return 0; 651 652 tx_error_icmp: 653 dst_link_failure(skb); 654 tx_error: 655 stats->tx_errors++; 656 dev_kfree_skb(skb); 657 tunnel->recursion--; 658 return 0; 659 } 660 661 static int 662 ipip_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) 663 { 664 int err = 0; 665 struct ip_tunnel_parm p; 666 struct ip_tunnel *t; 667 668 switch (cmd) { 669 case SIOCGETTUNNEL: 670 t = NULL; 671 if (dev == ipip_fb_tunnel_dev) { 672 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 673 err = -EFAULT; 674 break; 675 } 676 t = ipip_tunnel_locate(&p, 0); 677 } 678 if (t == NULL) 679 t = netdev_priv(dev); 680 memcpy(&p, &t->parms, sizeof(p)); 681 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 682 err = -EFAULT; 683 break; 684 685 case SIOCADDTUNNEL: 686 case SIOCCHGTUNNEL: 687 err = -EPERM; 688 if (!capable(CAP_NET_ADMIN)) 689 goto done; 690 691 err = -EFAULT; 692 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 693 goto done; 694 695 err = -EINVAL; 696 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP || 697 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) 698 goto done; 699 if (p.iph.ttl) 700 p.iph.frag_off |= htons(IP_DF); 701 702 t = ipip_tunnel_locate(&p, cmd == SIOCADDTUNNEL); 703 704 if (dev != ipip_fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 705 if (t != NULL) { 706 if (t->dev != dev) { 707 err = -EEXIST; 708 break; 709 } 710 } else { 711 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || 712 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { 713 err = -EINVAL; 714 break; 715 } 716 t = netdev_priv(dev); 717 ipip_tunnel_unlink(t); 718 t->parms.iph.saddr = p.iph.saddr; 719 t->parms.iph.daddr = p.iph.daddr; 720 memcpy(dev->dev_addr, &p.iph.saddr, 4); 721 memcpy(dev->broadcast, &p.iph.daddr, 4); 722 ipip_tunnel_link(t); 723 netdev_state_change(dev); 724 } 725 } 726 727 if (t) { 728 err = 0; 729 if (cmd == SIOCCHGTUNNEL) { 730 t->parms.iph.ttl = p.iph.ttl; 731 t->parms.iph.tos = p.iph.tos; 732 t->parms.iph.frag_off = p.iph.frag_off; 733 } 734 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) 735 err = -EFAULT; 736 } else 737 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 738 break; 739 740 case SIOCDELTUNNEL: 741 err = -EPERM; 742 if (!capable(CAP_NET_ADMIN)) 743 goto done; 744 745 if (dev == ipip_fb_tunnel_dev) { 746 err = -EFAULT; 747 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 748 goto done; 749 err = -ENOENT; 750 if ((t = ipip_tunnel_locate(&p, 0)) == NULL) 751 goto done; 752 err = -EPERM; 753 if (t->dev == ipip_fb_tunnel_dev) 754 goto done; 755 dev = t->dev; 756 } 757 err = unregister_netdevice(dev); 758 break; 759 760 default: 761 err = -EINVAL; 762 } 763 764 done: 765 return err; 766 } 767 768 static struct net_device_stats *ipip_tunnel_get_stats(struct net_device *dev) 769 { 770 return &(((struct ip_tunnel*)netdev_priv(dev))->stat); 771 } 772 773 static int ipip_tunnel_change_mtu(struct net_device *dev, int new_mtu) 774 { 775 if (new_mtu < 68 || new_mtu > 0xFFF8 - sizeof(struct iphdr)) 776 return -EINVAL; 777 dev->mtu = new_mtu; 778 return 0; 779 } 780 781 static void ipip_tunnel_setup(struct net_device *dev) 782 { 783 SET_MODULE_OWNER(dev); 784 dev->uninit = ipip_tunnel_uninit; 785 dev->hard_start_xmit = ipip_tunnel_xmit; 786 dev->get_stats = ipip_tunnel_get_stats; 787 dev->do_ioctl = ipip_tunnel_ioctl; 788 dev->change_mtu = ipip_tunnel_change_mtu; 789 dev->destructor = free_netdev; 790 791 dev->type = ARPHRD_TUNNEL; 792 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); 793 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr); 794 dev->flags = IFF_NOARP; 795 dev->iflink = 0; 796 dev->addr_len = 4; 797 } 798 799 static int ipip_tunnel_init(struct net_device *dev) 800 { 801 struct net_device *tdev = NULL; 802 struct ip_tunnel *tunnel; 803 struct iphdr *iph; 804 805 tunnel = netdev_priv(dev); 806 iph = &tunnel->parms.iph; 807 808 tunnel->dev = dev; 809 strcpy(tunnel->parms.name, dev->name); 810 811 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); 812 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); 813 814 if (iph->daddr) { 815 struct flowi fl = { .oif = tunnel->parms.link, 816 .nl_u = { .ip4_u = 817 { .daddr = iph->daddr, 818 .saddr = iph->saddr, 819 .tos = RT_TOS(iph->tos) } }, 820 .proto = IPPROTO_IPIP }; 821 struct rtable *rt; 822 if (!ip_route_output_key(&rt, &fl)) { 823 tdev = rt->u.dst.dev; 824 ip_rt_put(rt); 825 } 826 dev->flags |= IFF_POINTOPOINT; 827 } 828 829 if (!tdev && tunnel->parms.link) 830 tdev = __dev_get_by_index(tunnel->parms.link); 831 832 if (tdev) { 833 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); 834 dev->mtu = tdev->mtu - sizeof(struct iphdr); 835 } 836 dev->iflink = tunnel->parms.link; 837 838 return 0; 839 } 840 841 static int __init ipip_fb_tunnel_init(struct net_device *dev) 842 { 843 struct ip_tunnel *tunnel = netdev_priv(dev); 844 struct iphdr *iph = &tunnel->parms.iph; 845 846 tunnel->dev = dev; 847 strcpy(tunnel->parms.name, dev->name); 848 849 iph->version = 4; 850 iph->protocol = IPPROTO_IPIP; 851 iph->ihl = 5; 852 853 dev_hold(dev); 854 tunnels_wc[0] = tunnel; 855 return 0; 856 } 857 858 #ifdef CONFIG_INET_TUNNEL 859 static struct xfrm_tunnel ipip_handler = { 860 .handler = ipip_rcv, 861 .err_handler = ipip_err, 862 }; 863 864 static inline int ipip_register(void) 865 { 866 return xfrm4_tunnel_register(&ipip_handler); 867 } 868 869 static inline int ipip_unregister(void) 870 { 871 return xfrm4_tunnel_deregister(&ipip_handler); 872 } 873 #else 874 static struct net_protocol ipip_protocol = { 875 .handler = ipip_rcv, 876 .err_handler = ipip_err, 877 .no_policy = 1, 878 }; 879 880 static inline int ipip_register(void) 881 { 882 return inet_add_protocol(&ipip_protocol, IPPROTO_IPIP); 883 } 884 885 static inline int ipip_unregister(void) 886 { 887 return inet_del_protocol(&ipip_protocol, IPPROTO_IPIP); 888 } 889 #endif 890 891 static char banner[] __initdata = 892 KERN_INFO "IPv4 over IPv4 tunneling driver\n"; 893 894 static int __init ipip_init(void) 895 { 896 int err; 897 898 printk(banner); 899 900 if (ipip_register() < 0) { 901 printk(KERN_INFO "ipip init: can't register tunnel\n"); 902 return -EAGAIN; 903 } 904 905 ipip_fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), 906 "tunl0", 907 ipip_tunnel_setup); 908 if (!ipip_fb_tunnel_dev) { 909 err = -ENOMEM; 910 goto err1; 911 } 912 913 ipip_fb_tunnel_dev->init = ipip_fb_tunnel_init; 914 915 if ((err = register_netdev(ipip_fb_tunnel_dev))) 916 goto err2; 917 out: 918 return err; 919 err2: 920 free_netdev(ipip_fb_tunnel_dev); 921 err1: 922 ipip_unregister(); 923 goto out; 924 } 925 926 static void __exit ipip_destroy_tunnels(void) 927 { 928 int prio; 929 930 for (prio = 1; prio < 4; prio++) { 931 int h; 932 for (h = 0; h < HASH_SIZE; h++) { 933 struct ip_tunnel *t; 934 while ((t = tunnels[prio][h]) != NULL) 935 unregister_netdevice(t->dev); 936 } 937 } 938 } 939 940 static void __exit ipip_fini(void) 941 { 942 if (ipip_unregister() < 0) 943 printk(KERN_INFO "ipip close: can't deregister tunnel\n"); 944 945 rtnl_lock(); 946 ipip_destroy_tunnels(); 947 unregister_netdevice(ipip_fb_tunnel_dev); 948 rtnl_unlock(); 949 } 950 951 module_init(ipip_init); 952 module_exit(ipip_fini); 953 MODULE_LICENSE("GPL"); 954