Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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/config.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 | |
| 112 | #include <net/sock.h> |
| 113 | #include <net/ip.h> |
| 114 | #include <net/icmp.h> |
| 115 | #include <net/protocol.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 = dev->priv; |
| 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 | /* Do not decrement MOD_USE_COUNT here. */ |
| 259 | return nt; |
| 260 | |
| 261 | failed: |
| 262 | return NULL; |
| 263 | } |
| 264 | |
| 265 | static void ipip_tunnel_uninit(struct net_device *dev) |
| 266 | { |
| 267 | if (dev == ipip_fb_tunnel_dev) { |
| 268 | write_lock_bh(&ipip_lock); |
| 269 | tunnels_wc[0] = NULL; |
| 270 | write_unlock_bh(&ipip_lock); |
| 271 | } else |
| 272 | ipip_tunnel_unlink((struct ip_tunnel*)dev->priv); |
| 273 | dev_put(dev); |
| 274 | } |
| 275 | |
Patrick McHardy | 0303770 | 2005-07-19 14:03:34 -0700 | [diff] [blame^] | 276 | static void ipip_err(struct sk_buff *skb, u32 info) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 277 | { |
| 278 | #ifndef I_WISH_WORLD_WERE_PERFECT |
| 279 | |
| 280 | /* It is not :-( All the routers (except for Linux) return only |
| 281 | 8 bytes of packet payload. It means, that precise relaying of |
| 282 | ICMP in the real Internet is absolutely infeasible. |
| 283 | */ |
| 284 | struct iphdr *iph = (struct iphdr*)skb->data; |
| 285 | int type = skb->h.icmph->type; |
| 286 | int code = skb->h.icmph->code; |
| 287 | struct ip_tunnel *t; |
| 288 | |
| 289 | switch (type) { |
| 290 | default: |
| 291 | case ICMP_PARAMETERPROB: |
| 292 | return; |
| 293 | |
| 294 | case ICMP_DEST_UNREACH: |
| 295 | switch (code) { |
| 296 | case ICMP_SR_FAILED: |
| 297 | case ICMP_PORT_UNREACH: |
| 298 | /* Impossible event. */ |
| 299 | return; |
| 300 | case ICMP_FRAG_NEEDED: |
| 301 | /* Soft state for pmtu is maintained by IP core. */ |
| 302 | return; |
| 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; |
| 314 | break; |
| 315 | } |
| 316 | |
| 317 | read_lock(&ipip_lock); |
| 318 | t = ipip_tunnel_lookup(iph->daddr, iph->saddr); |
| 319 | if (t == NULL || t->parms.iph.daddr == 0) |
| 320 | goto out; |
| 321 | if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) |
| 322 | goto out; |
| 323 | |
| 324 | if (jiffies - t->err_time < IPTUNNEL_ERR_TIMEO) |
| 325 | t->err_count++; |
| 326 | else |
| 327 | t->err_count = 1; |
| 328 | t->err_time = jiffies; |
| 329 | out: |
| 330 | read_unlock(&ipip_lock); |
| 331 | return; |
| 332 | #else |
| 333 | struct iphdr *iph = (struct iphdr*)dp; |
| 334 | int hlen = iph->ihl<<2; |
| 335 | struct iphdr *eiph; |
| 336 | int type = skb->h.icmph->type; |
| 337 | int code = skb->h.icmph->code; |
| 338 | int rel_type = 0; |
| 339 | int rel_code = 0; |
| 340 | int rel_info = 0; |
| 341 | struct sk_buff *skb2; |
| 342 | struct flowi fl; |
| 343 | struct rtable *rt; |
| 344 | |
| 345 | if (len < hlen + sizeof(struct iphdr)) |
| 346 | return; |
| 347 | eiph = (struct iphdr*)(dp + hlen); |
| 348 | |
| 349 | switch (type) { |
| 350 | default: |
| 351 | return; |
| 352 | case ICMP_PARAMETERPROB: |
| 353 | if (skb->h.icmph->un.gateway < hlen) |
| 354 | return; |
| 355 | |
| 356 | /* So... This guy found something strange INSIDE encapsulated |
| 357 | packet. Well, he is fool, but what can we do ? |
| 358 | */ |
| 359 | rel_type = ICMP_PARAMETERPROB; |
| 360 | rel_info = skb->h.icmph->un.gateway - hlen; |
| 361 | break; |
| 362 | |
| 363 | case ICMP_DEST_UNREACH: |
| 364 | switch (code) { |
| 365 | case ICMP_SR_FAILED: |
| 366 | case ICMP_PORT_UNREACH: |
| 367 | /* Impossible event. */ |
| 368 | return; |
| 369 | case ICMP_FRAG_NEEDED: |
| 370 | /* And it is the only really necessary thing :-) */ |
| 371 | rel_info = ntohs(skb->h.icmph->un.frag.mtu); |
| 372 | if (rel_info < hlen+68) |
| 373 | return; |
| 374 | rel_info -= hlen; |
| 375 | /* BSD 4.2 MORE DOES NOT EXIST IN NATURE. */ |
| 376 | if (rel_info > ntohs(eiph->tot_len)) |
| 377 | return; |
| 378 | break; |
| 379 | default: |
| 380 | /* All others are translated to HOST_UNREACH. |
| 381 | rfc2003 contains "deep thoughts" about NET_UNREACH, |
| 382 | I believe, it is just ether pollution. --ANK |
| 383 | */ |
| 384 | rel_type = ICMP_DEST_UNREACH; |
| 385 | rel_code = ICMP_HOST_UNREACH; |
| 386 | break; |
| 387 | } |
| 388 | break; |
| 389 | case ICMP_TIME_EXCEEDED: |
| 390 | if (code != ICMP_EXC_TTL) |
| 391 | return; |
| 392 | break; |
| 393 | } |
| 394 | |
| 395 | /* Prepare fake skb to feed it to icmp_send */ |
| 396 | skb2 = skb_clone(skb, GFP_ATOMIC); |
| 397 | if (skb2 == NULL) |
| 398 | return; |
| 399 | dst_release(skb2->dst); |
| 400 | skb2->dst = NULL; |
| 401 | skb_pull(skb2, skb->data - (u8*)eiph); |
| 402 | skb2->nh.raw = skb2->data; |
| 403 | |
| 404 | /* Try to guess incoming interface */ |
| 405 | memset(&fl, 0, sizeof(fl)); |
| 406 | fl.fl4_daddr = eiph->saddr; |
| 407 | fl.fl4_tos = RT_TOS(eiph->tos); |
| 408 | fl.proto = IPPROTO_IPIP; |
| 409 | if (ip_route_output_key(&rt, &key)) { |
| 410 | kfree_skb(skb2); |
| 411 | return; |
| 412 | } |
| 413 | skb2->dev = rt->u.dst.dev; |
| 414 | |
| 415 | /* route "incoming" packet */ |
| 416 | if (rt->rt_flags&RTCF_LOCAL) { |
| 417 | ip_rt_put(rt); |
| 418 | rt = NULL; |
| 419 | fl.fl4_daddr = eiph->daddr; |
| 420 | fl.fl4_src = eiph->saddr; |
| 421 | fl.fl4_tos = eiph->tos; |
| 422 | if (ip_route_output_key(&rt, &fl) || |
| 423 | rt->u.dst.dev->type != ARPHRD_TUNNEL) { |
| 424 | ip_rt_put(rt); |
| 425 | kfree_skb(skb2); |
| 426 | return; |
| 427 | } |
| 428 | } else { |
| 429 | ip_rt_put(rt); |
| 430 | if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos, skb2->dev) || |
| 431 | skb2->dst->dev->type != ARPHRD_TUNNEL) { |
| 432 | kfree_skb(skb2); |
| 433 | return; |
| 434 | } |
| 435 | } |
| 436 | |
| 437 | /* change mtu on this route */ |
| 438 | if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { |
| 439 | if (rel_info > dst_mtu(skb2->dst)) { |
| 440 | kfree_skb(skb2); |
| 441 | return; |
| 442 | } |
| 443 | skb2->dst->ops->update_pmtu(skb2->dst, rel_info); |
| 444 | rel_info = htonl(rel_info); |
| 445 | } else if (type == ICMP_TIME_EXCEEDED) { |
| 446 | struct ip_tunnel *t = (struct ip_tunnel*)skb2->dev->priv; |
| 447 | if (t->parms.iph.ttl) { |
| 448 | rel_type = ICMP_DEST_UNREACH; |
| 449 | rel_code = ICMP_HOST_UNREACH; |
| 450 | } |
| 451 | } |
| 452 | |
| 453 | icmp_send(skb2, rel_type, rel_code, rel_info); |
| 454 | kfree_skb(skb2); |
| 455 | return; |
| 456 | #endif |
| 457 | } |
| 458 | |
| 459 | static inline void ipip_ecn_decapsulate(struct iphdr *outer_iph, struct sk_buff *skb) |
| 460 | { |
| 461 | struct iphdr *inner_iph = skb->nh.iph; |
| 462 | |
| 463 | if (INET_ECN_is_ce(outer_iph->tos)) |
| 464 | IP_ECN_set_ce(inner_iph); |
| 465 | } |
| 466 | |
| 467 | static int ipip_rcv(struct sk_buff *skb) |
| 468 | { |
| 469 | struct iphdr *iph; |
| 470 | struct ip_tunnel *tunnel; |
| 471 | |
| 472 | if (!pskb_may_pull(skb, sizeof(struct iphdr))) |
| 473 | goto out; |
| 474 | |
| 475 | iph = skb->nh.iph; |
| 476 | |
| 477 | read_lock(&ipip_lock); |
| 478 | if ((tunnel = ipip_tunnel_lookup(iph->saddr, iph->daddr)) != NULL) { |
| 479 | if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { |
| 480 | read_unlock(&ipip_lock); |
| 481 | kfree_skb(skb); |
| 482 | return 0; |
| 483 | } |
| 484 | |
| 485 | secpath_reset(skb); |
| 486 | |
| 487 | skb->mac.raw = skb->nh.raw; |
| 488 | skb->nh.raw = skb->data; |
| 489 | memset(&(IPCB(skb)->opt), 0, sizeof(struct ip_options)); |
| 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 | out: |
| 507 | return -1; |
| 508 | } |
| 509 | |
| 510 | /* |
| 511 | * This function assumes it is being called from dev_queue_xmit() |
| 512 | * and that skb is filled properly by that function. |
| 513 | */ |
| 514 | |
| 515 | static int ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) |
| 516 | { |
| 517 | struct ip_tunnel *tunnel = (struct ip_tunnel*)dev->priv; |
| 518 | struct net_device_stats *stats = &tunnel->stat; |
| 519 | struct iphdr *tiph = &tunnel->parms.iph; |
| 520 | u8 tos = tunnel->parms.iph.tos; |
| 521 | u16 df = tiph->frag_off; |
| 522 | struct rtable *rt; /* Route to the other host */ |
| 523 | struct net_device *tdev; /* Device to other host */ |
| 524 | struct iphdr *old_iph = skb->nh.iph; |
| 525 | struct iphdr *iph; /* Our new IP header */ |
| 526 | int max_headroom; /* The extra header space needed */ |
| 527 | u32 dst = tiph->daddr; |
| 528 | int mtu; |
| 529 | |
| 530 | if (tunnel->recursion++) { |
| 531 | tunnel->stat.collisions++; |
| 532 | goto tx_error; |
| 533 | } |
| 534 | |
| 535 | if (skb->protocol != htons(ETH_P_IP)) |
| 536 | goto tx_error; |
| 537 | |
| 538 | if (tos&1) |
| 539 | tos = old_iph->tos; |
| 540 | |
| 541 | if (!dst) { |
| 542 | /* NBMA tunnel */ |
| 543 | if ((rt = (struct rtable*)skb->dst) == NULL) { |
| 544 | tunnel->stat.tx_fifo_errors++; |
| 545 | goto tx_error; |
| 546 | } |
| 547 | if ((dst = rt->rt_gateway) == 0) |
| 548 | goto tx_error_icmp; |
| 549 | } |
| 550 | |
| 551 | { |
| 552 | struct flowi fl = { .oif = tunnel->parms.link, |
| 553 | .nl_u = { .ip4_u = |
| 554 | { .daddr = dst, |
| 555 | .saddr = tiph->saddr, |
| 556 | .tos = RT_TOS(tos) } }, |
| 557 | .proto = IPPROTO_IPIP }; |
| 558 | if (ip_route_output_key(&rt, &fl)) { |
| 559 | tunnel->stat.tx_carrier_errors++; |
| 560 | goto tx_error_icmp; |
| 561 | } |
| 562 | } |
| 563 | tdev = rt->u.dst.dev; |
| 564 | |
| 565 | if (tdev == dev) { |
| 566 | ip_rt_put(rt); |
| 567 | tunnel->stat.collisions++; |
| 568 | goto tx_error; |
| 569 | } |
| 570 | |
| 571 | if (tiph->frag_off) |
| 572 | mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr); |
| 573 | else |
| 574 | mtu = skb->dst ? dst_mtu(skb->dst) : dev->mtu; |
| 575 | |
| 576 | if (mtu < 68) { |
| 577 | tunnel->stat.collisions++; |
| 578 | ip_rt_put(rt); |
| 579 | goto tx_error; |
| 580 | } |
| 581 | if (skb->dst) |
| 582 | skb->dst->ops->update_pmtu(skb->dst, mtu); |
| 583 | |
| 584 | df |= (old_iph->frag_off&htons(IP_DF)); |
| 585 | |
| 586 | if ((old_iph->frag_off&htons(IP_DF)) && mtu < ntohs(old_iph->tot_len)) { |
| 587 | icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu)); |
| 588 | ip_rt_put(rt); |
| 589 | goto tx_error; |
| 590 | } |
| 591 | |
| 592 | if (tunnel->err_count > 0) { |
| 593 | if (jiffies - tunnel->err_time < IPTUNNEL_ERR_TIMEO) { |
| 594 | tunnel->err_count--; |
| 595 | dst_link_failure(skb); |
| 596 | } else |
| 597 | tunnel->err_count = 0; |
| 598 | } |
| 599 | |
| 600 | /* |
| 601 | * Okay, now see if we can stuff it in the buffer as-is. |
| 602 | */ |
| 603 | max_headroom = (LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr)); |
| 604 | |
| 605 | if (skb_headroom(skb) < max_headroom || skb_cloned(skb) || skb_shared(skb)) { |
| 606 | struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); |
| 607 | if (!new_skb) { |
| 608 | ip_rt_put(rt); |
| 609 | stats->tx_dropped++; |
| 610 | dev_kfree_skb(skb); |
| 611 | tunnel->recursion--; |
| 612 | return 0; |
| 613 | } |
| 614 | if (skb->sk) |
| 615 | skb_set_owner_w(new_skb, skb->sk); |
| 616 | dev_kfree_skb(skb); |
| 617 | skb = new_skb; |
| 618 | old_iph = skb->nh.iph; |
| 619 | } |
| 620 | |
| 621 | skb->h.raw = skb->nh.raw; |
| 622 | skb->nh.raw = skb_push(skb, sizeof(struct iphdr)); |
| 623 | memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); |
| 624 | dst_release(skb->dst); |
| 625 | skb->dst = &rt->u.dst; |
| 626 | |
| 627 | /* |
| 628 | * Push down and install the IPIP header. |
| 629 | */ |
| 630 | |
| 631 | iph = skb->nh.iph; |
| 632 | iph->version = 4; |
| 633 | iph->ihl = sizeof(struct iphdr)>>2; |
| 634 | iph->frag_off = df; |
| 635 | iph->protocol = IPPROTO_IPIP; |
| 636 | iph->tos = INET_ECN_encapsulate(tos, old_iph->tos); |
| 637 | iph->daddr = rt->rt_dst; |
| 638 | iph->saddr = rt->rt_src; |
| 639 | |
| 640 | if ((iph->ttl = tiph->ttl) == 0) |
| 641 | iph->ttl = old_iph->ttl; |
| 642 | |
| 643 | nf_reset(skb); |
| 644 | |
| 645 | IPTUNNEL_XMIT(); |
| 646 | tunnel->recursion--; |
| 647 | return 0; |
| 648 | |
| 649 | tx_error_icmp: |
| 650 | dst_link_failure(skb); |
| 651 | tx_error: |
| 652 | stats->tx_errors++; |
| 653 | dev_kfree_skb(skb); |
| 654 | tunnel->recursion--; |
| 655 | return 0; |
| 656 | } |
| 657 | |
| 658 | static int |
| 659 | ipip_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) |
| 660 | { |
| 661 | int err = 0; |
| 662 | struct ip_tunnel_parm p; |
| 663 | struct ip_tunnel *t; |
| 664 | |
| 665 | switch (cmd) { |
| 666 | case SIOCGETTUNNEL: |
| 667 | t = NULL; |
| 668 | if (dev == ipip_fb_tunnel_dev) { |
| 669 | if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { |
| 670 | err = -EFAULT; |
| 671 | break; |
| 672 | } |
| 673 | t = ipip_tunnel_locate(&p, 0); |
| 674 | } |
| 675 | if (t == NULL) |
| 676 | t = (struct ip_tunnel*)dev->priv; |
| 677 | memcpy(&p, &t->parms, sizeof(p)); |
| 678 | if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) |
| 679 | err = -EFAULT; |
| 680 | break; |
| 681 | |
| 682 | case SIOCADDTUNNEL: |
| 683 | case SIOCCHGTUNNEL: |
| 684 | err = -EPERM; |
| 685 | if (!capable(CAP_NET_ADMIN)) |
| 686 | goto done; |
| 687 | |
| 688 | err = -EFAULT; |
| 689 | if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) |
| 690 | goto done; |
| 691 | |
| 692 | err = -EINVAL; |
| 693 | if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP || |
| 694 | p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) |
| 695 | goto done; |
| 696 | if (p.iph.ttl) |
| 697 | p.iph.frag_off |= htons(IP_DF); |
| 698 | |
| 699 | t = ipip_tunnel_locate(&p, cmd == SIOCADDTUNNEL); |
| 700 | |
| 701 | if (dev != ipip_fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { |
| 702 | if (t != NULL) { |
| 703 | if (t->dev != dev) { |
| 704 | err = -EEXIST; |
| 705 | break; |
| 706 | } |
| 707 | } else { |
| 708 | if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || |
| 709 | (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { |
| 710 | err = -EINVAL; |
| 711 | break; |
| 712 | } |
| 713 | t = (struct ip_tunnel*)dev->priv; |
| 714 | ipip_tunnel_unlink(t); |
| 715 | t->parms.iph.saddr = p.iph.saddr; |
| 716 | t->parms.iph.daddr = p.iph.daddr; |
| 717 | memcpy(dev->dev_addr, &p.iph.saddr, 4); |
| 718 | memcpy(dev->broadcast, &p.iph.daddr, 4); |
| 719 | ipip_tunnel_link(t); |
| 720 | netdev_state_change(dev); |
| 721 | } |
| 722 | } |
| 723 | |
| 724 | if (t) { |
| 725 | err = 0; |
| 726 | if (cmd == SIOCCHGTUNNEL) { |
| 727 | t->parms.iph.ttl = p.iph.ttl; |
| 728 | t->parms.iph.tos = p.iph.tos; |
| 729 | t->parms.iph.frag_off = p.iph.frag_off; |
| 730 | } |
| 731 | if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) |
| 732 | err = -EFAULT; |
| 733 | } else |
| 734 | err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); |
| 735 | break; |
| 736 | |
| 737 | case SIOCDELTUNNEL: |
| 738 | err = -EPERM; |
| 739 | if (!capable(CAP_NET_ADMIN)) |
| 740 | goto done; |
| 741 | |
| 742 | if (dev == ipip_fb_tunnel_dev) { |
| 743 | err = -EFAULT; |
| 744 | if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) |
| 745 | goto done; |
| 746 | err = -ENOENT; |
| 747 | if ((t = ipip_tunnel_locate(&p, 0)) == NULL) |
| 748 | goto done; |
| 749 | err = -EPERM; |
| 750 | if (t->dev == ipip_fb_tunnel_dev) |
| 751 | goto done; |
| 752 | dev = t->dev; |
| 753 | } |
| 754 | err = unregister_netdevice(dev); |
| 755 | break; |
| 756 | |
| 757 | default: |
| 758 | err = -EINVAL; |
| 759 | } |
| 760 | |
| 761 | done: |
| 762 | return err; |
| 763 | } |
| 764 | |
| 765 | static struct net_device_stats *ipip_tunnel_get_stats(struct net_device *dev) |
| 766 | { |
| 767 | return &(((struct ip_tunnel*)dev->priv)->stat); |
| 768 | } |
| 769 | |
| 770 | static int ipip_tunnel_change_mtu(struct net_device *dev, int new_mtu) |
| 771 | { |
| 772 | if (new_mtu < 68 || new_mtu > 0xFFF8 - sizeof(struct iphdr)) |
| 773 | return -EINVAL; |
| 774 | dev->mtu = new_mtu; |
| 775 | return 0; |
| 776 | } |
| 777 | |
| 778 | static void ipip_tunnel_setup(struct net_device *dev) |
| 779 | { |
| 780 | SET_MODULE_OWNER(dev); |
| 781 | dev->uninit = ipip_tunnel_uninit; |
| 782 | dev->hard_start_xmit = ipip_tunnel_xmit; |
| 783 | dev->get_stats = ipip_tunnel_get_stats; |
| 784 | dev->do_ioctl = ipip_tunnel_ioctl; |
| 785 | dev->change_mtu = ipip_tunnel_change_mtu; |
| 786 | dev->destructor = free_netdev; |
| 787 | |
| 788 | dev->type = ARPHRD_TUNNEL; |
| 789 | dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); |
| 790 | dev->mtu = 1500 - sizeof(struct iphdr); |
| 791 | dev->flags = IFF_NOARP; |
| 792 | dev->iflink = 0; |
| 793 | dev->addr_len = 4; |
| 794 | } |
| 795 | |
| 796 | static int ipip_tunnel_init(struct net_device *dev) |
| 797 | { |
| 798 | struct net_device *tdev = NULL; |
| 799 | struct ip_tunnel *tunnel; |
| 800 | struct iphdr *iph; |
| 801 | |
| 802 | tunnel = (struct ip_tunnel*)dev->priv; |
| 803 | iph = &tunnel->parms.iph; |
| 804 | |
| 805 | tunnel->dev = dev; |
| 806 | strcpy(tunnel->parms.name, dev->name); |
| 807 | |
| 808 | memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); |
| 809 | memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); |
| 810 | |
| 811 | if (iph->daddr) { |
| 812 | struct flowi fl = { .oif = tunnel->parms.link, |
| 813 | .nl_u = { .ip4_u = |
| 814 | { .daddr = iph->daddr, |
| 815 | .saddr = iph->saddr, |
| 816 | .tos = RT_TOS(iph->tos) } }, |
| 817 | .proto = IPPROTO_IPIP }; |
| 818 | struct rtable *rt; |
| 819 | if (!ip_route_output_key(&rt, &fl)) { |
| 820 | tdev = rt->u.dst.dev; |
| 821 | ip_rt_put(rt); |
| 822 | } |
| 823 | dev->flags |= IFF_POINTOPOINT; |
| 824 | } |
| 825 | |
| 826 | if (!tdev && tunnel->parms.link) |
| 827 | tdev = __dev_get_by_index(tunnel->parms.link); |
| 828 | |
| 829 | if (tdev) { |
| 830 | dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); |
| 831 | dev->mtu = tdev->mtu - sizeof(struct iphdr); |
| 832 | } |
| 833 | dev->iflink = tunnel->parms.link; |
| 834 | |
| 835 | return 0; |
| 836 | } |
| 837 | |
| 838 | static int __init ipip_fb_tunnel_init(struct net_device *dev) |
| 839 | { |
| 840 | struct ip_tunnel *tunnel = dev->priv; |
| 841 | struct iphdr *iph = &tunnel->parms.iph; |
| 842 | |
| 843 | tunnel->dev = dev; |
| 844 | strcpy(tunnel->parms.name, dev->name); |
| 845 | |
| 846 | iph->version = 4; |
| 847 | iph->protocol = IPPROTO_IPIP; |
| 848 | iph->ihl = 5; |
| 849 | |
| 850 | dev_hold(dev); |
| 851 | tunnels_wc[0] = tunnel; |
| 852 | return 0; |
| 853 | } |
| 854 | |
Patrick McHardy | 0303770 | 2005-07-19 14:03:34 -0700 | [diff] [blame^] | 855 | #ifdef CONFIG_INET_TUNNEL |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 856 | static struct xfrm_tunnel ipip_handler = { |
| 857 | .handler = ipip_rcv, |
| 858 | .err_handler = ipip_err, |
| 859 | }; |
| 860 | |
Patrick McHardy | 0303770 | 2005-07-19 14:03:34 -0700 | [diff] [blame^] | 861 | static inline int ipip_register(void) |
| 862 | { |
| 863 | return xfrm4_tunnel_register(&ipip_handler); |
| 864 | } |
| 865 | |
| 866 | static inline int ipip_unregister(void) |
| 867 | { |
| 868 | return xfrm4_tunnel_deregister(&ipip_handler); |
| 869 | } |
| 870 | #else |
| 871 | static struct net_protocol ipip_protocol = { |
| 872 | .handler = ipip_rcv, |
| 873 | .err_handler = ipip_err, |
| 874 | .no_policy = 1, |
| 875 | }; |
| 876 | |
| 877 | static inline int ipip_register(void) |
| 878 | { |
| 879 | return inet_add_protocol(&ipip_protocol, IPPROTO_IPIP); |
| 880 | } |
| 881 | |
| 882 | static inline int ipip_unregister(void) |
| 883 | { |
| 884 | return inet_del_protocol(&ipip_protocol, IPPROTO_IPIP); |
| 885 | } |
| 886 | #endif |
| 887 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 888 | static char banner[] __initdata = |
| 889 | KERN_INFO "IPv4 over IPv4 tunneling driver\n"; |
| 890 | |
| 891 | static int __init ipip_init(void) |
| 892 | { |
| 893 | int err; |
| 894 | |
| 895 | printk(banner); |
| 896 | |
Patrick McHardy | 0303770 | 2005-07-19 14:03:34 -0700 | [diff] [blame^] | 897 | if (ipip_register() < 0) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 898 | printk(KERN_INFO "ipip init: can't register tunnel\n"); |
| 899 | return -EAGAIN; |
| 900 | } |
| 901 | |
| 902 | ipip_fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), |
| 903 | "tunl0", |
| 904 | ipip_tunnel_setup); |
| 905 | if (!ipip_fb_tunnel_dev) { |
| 906 | err = -ENOMEM; |
| 907 | goto err1; |
| 908 | } |
| 909 | |
| 910 | ipip_fb_tunnel_dev->init = ipip_fb_tunnel_init; |
| 911 | |
| 912 | if ((err = register_netdev(ipip_fb_tunnel_dev))) |
| 913 | goto err2; |
| 914 | out: |
| 915 | return err; |
| 916 | err2: |
| 917 | free_netdev(ipip_fb_tunnel_dev); |
| 918 | err1: |
Patrick McHardy | 0303770 | 2005-07-19 14:03:34 -0700 | [diff] [blame^] | 919 | ipip_unregister(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 920 | goto out; |
| 921 | } |
| 922 | |
| 923 | static void __exit ipip_fini(void) |
| 924 | { |
Patrick McHardy | 0303770 | 2005-07-19 14:03:34 -0700 | [diff] [blame^] | 925 | if (ipip_unregister() < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 926 | printk(KERN_INFO "ipip close: can't deregister tunnel\n"); |
| 927 | |
| 928 | unregister_netdev(ipip_fb_tunnel_dev); |
| 929 | } |
| 930 | |
| 931 | module_init(ipip_init); |
| 932 | module_exit(ipip_fini); |
| 933 | MODULE_LICENSE("GPL"); |