| 1 | /* |
| 2 | * Linux NET3: IP/IP protocol decoder. |
| 3 | * |
| 4 | * Authors: |
| 5 | * Sam Lantinga (slouken@cs.ucdavis.edu) 02/01/95 |
| 6 | * |
| 7 | * Fixes: |
| 8 | * Alan Cox : Merged and made usable non modular (its so tiny its silly as |
| 9 | * a module taking up 2 pages). |
| 10 | * Alan Cox : Fixed bug with 1.3.18 and IPIP not working (now needs to set skb->h.iph) |
| 11 | * to keep ip_forward happy. |
| 12 | * Alan Cox : More fixes for 1.3.21, and firewall fix. Maybe this will work soon 8). |
| 13 | * Kai Schulte : Fixed #defines for IP_FIREWALL->FIREWALL |
| 14 | * David Woodhouse : Perform some basic ICMP handling. |
| 15 | * IPIP Routing without decapsulation. |
| 16 | * Carlos Picoto : GRE over IP support |
| 17 | * Alexey Kuznetsov: Reworked. Really, now it is truncated version of ipv4/ip_gre.c. |
| 18 | * I do not want to merge them together. |
| 19 | * |
| 20 | * This program is free software; you can redistribute it and/or |
| 21 | * modify it under the terms of the GNU General Public License |
| 22 | * as published by the Free Software Foundation; either version |
| 23 | * 2 of the License, or (at your option) any later version. |
| 24 | * |
| 25 | */ |
| 26 | |
| 27 | /* tunnel.c: an IP tunnel driver |
| 28 | |
| 29 | The purpose of this driver is to provide an IP tunnel through |
| 30 | which you can tunnel network traffic transparently across subnets. |
| 31 | |
| 32 | This was written by looking at Nick Holloway's dummy driver |
| 33 | Thanks for the great code! |
| 34 | |
| 35 | -Sam Lantinga (slouken@cs.ucdavis.edu) 02/01/95 |
| 36 | |
| 37 | Minor tweaks: |
| 38 | Cleaned up the code a little and added some pre-1.3.0 tweaks. |
| 39 | dev->hard_header/hard_header_len changed to use no headers. |
| 40 | Comments/bracketing tweaked. |
| 41 | Made the tunnels use dev->name not tunnel: when error reporting. |
| 42 | Added tx_dropped stat |
| 43 | |
| 44 | -Alan Cox (alan@lxorguk.ukuu.org.uk) 21 March 95 |
| 45 | |
| 46 | Reworked: |
| 47 | Changed to tunnel to destination gateway in addition to the |
| 48 | tunnel's pointopoint address |
| 49 | Almost completely rewritten |
| 50 | Note: There is currently no firewall or ICMP handling done. |
| 51 | |
| 52 | -Sam Lantinga (slouken@cs.ucdavis.edu) 02/13/96 |
| 53 | |
| 54 | */ |
| 55 | |
| 56 | /* Things I wish I had known when writing the tunnel driver: |
| 57 | |
| 58 | When the tunnel_xmit() function is called, the skb contains the |
| 59 | packet to be sent (plus a great deal of extra info), and dev |
| 60 | contains the tunnel device that _we_ are. |
| 61 | |
| 62 | When we are passed a packet, we are expected to fill in the |
| 63 | source address with our source IP address. |
| 64 | |
| 65 | What is the proper way to allocate, copy and free a buffer? |
| 66 | After you allocate it, it is a "0 length" chunk of memory |
| 67 | starting at zero. If you want to add headers to the buffer |
| 68 | later, you'll have to call "skb_reserve(skb, amount)" with |
| 69 | the amount of memory you want reserved. Then, you call |
| 70 | "skb_put(skb, amount)" with the amount of space you want in |
| 71 | the buffer. skb_put() returns a pointer to the top (#0) of |
| 72 | that buffer. skb->len is set to the amount of space you have |
| 73 | "allocated" with skb_put(). You can then write up to skb->len |
| 74 | bytes to that buffer. If you need more, you can call skb_put() |
| 75 | again with the additional amount of space you need. You can |
| 76 | find out how much more space you can allocate by calling |
| 77 | "skb_tailroom(skb)". |
| 78 | Now, to add header space, call "skb_push(skb, header_len)". |
| 79 | This creates space at the beginning of the buffer and returns |
| 80 | a pointer to this new space. If later you need to strip a |
| 81 | header from a buffer, call "skb_pull(skb, header_len)". |
| 82 | skb_headroom() will return how much space is left at the top |
| 83 | of the buffer (before the main data). Remember, this headroom |
| 84 | space must be reserved before the skb_put() function is called. |
| 85 | */ |
| 86 | |
| 87 | /* |
| 88 | This version of net/ipv4/ipip.c is cloned of net/ipv4/ip_gre.c |
| 89 | |
| 90 | For comments look at net/ipv4/ip_gre.c --ANK |
| 91 | */ |
| 92 | |
| 93 | |
| 94 | #include <linux/capability.h> |
| 95 | #include <linux/module.h> |
| 96 | #include <linux/types.h> |
| 97 | #include <linux/kernel.h> |
| 98 | #include <linux/slab.h> |
| 99 | #include <asm/uaccess.h> |
| 100 | #include <linux/skbuff.h> |
| 101 | #include <linux/netdevice.h> |
| 102 | #include <linux/in.h> |
| 103 | #include <linux/tcp.h> |
| 104 | #include <linux/udp.h> |
| 105 | #include <linux/if_arp.h> |
| 106 | #include <linux/mroute.h> |
| 107 | #include <linux/init.h> |
| 108 | #include <linux/netfilter_ipv4.h> |
| 109 | #include <linux/if_ether.h> |
| 110 | |
| 111 | #include <net/sock.h> |
| 112 | #include <net/ip.h> |
| 113 | #include <net/icmp.h> |
| 114 | #include <net/ipip.h> |
| 115 | #include <net/inet_ecn.h> |
| 116 | #include <net/xfrm.h> |
| 117 | #include <net/net_namespace.h> |
| 118 | #include <net/netns/generic.h> |
| 119 | |
| 120 | #define HASH_SIZE 16 |
| 121 | #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF) |
| 122 | |
| 123 | static int ipip_net_id __read_mostly; |
| 124 | struct ipip_net { |
| 125 | struct ip_tunnel __rcu *tunnels_r_l[HASH_SIZE]; |
| 126 | struct ip_tunnel __rcu *tunnels_r[HASH_SIZE]; |
| 127 | struct ip_tunnel __rcu *tunnels_l[HASH_SIZE]; |
| 128 | struct ip_tunnel __rcu *tunnels_wc[1]; |
| 129 | struct ip_tunnel __rcu **tunnels[4]; |
| 130 | |
| 131 | struct net_device *fb_tunnel_dev; |
| 132 | }; |
| 133 | |
| 134 | static int ipip_tunnel_init(struct net_device *dev); |
| 135 | static void ipip_tunnel_setup(struct net_device *dev); |
| 136 | static void ipip_dev_free(struct net_device *dev); |
| 137 | |
| 138 | /* |
| 139 | * Locking : hash tables are protected by RCU and RTNL |
| 140 | */ |
| 141 | |
| 142 | #define for_each_ip_tunnel_rcu(start) \ |
| 143 | for (t = rcu_dereference(start); t; t = rcu_dereference(t->next)) |
| 144 | |
| 145 | /* often modified stats are per cpu, other are shared (netdev->stats) */ |
| 146 | struct pcpu_tstats { |
| 147 | u64 rx_packets; |
| 148 | u64 rx_bytes; |
| 149 | u64 tx_packets; |
| 150 | u64 tx_bytes; |
| 151 | struct u64_stats_sync syncp; |
| 152 | }; |
| 153 | |
| 154 | static struct rtnl_link_stats64 *ipip_get_stats64(struct net_device *dev, |
| 155 | struct rtnl_link_stats64 *tot) |
| 156 | { |
| 157 | int i; |
| 158 | |
| 159 | for_each_possible_cpu(i) { |
| 160 | const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i); |
| 161 | u64 rx_packets, rx_bytes, tx_packets, tx_bytes; |
| 162 | unsigned int start; |
| 163 | |
| 164 | do { |
| 165 | start = u64_stats_fetch_begin_bh(&tstats->syncp); |
| 166 | rx_packets = tstats->rx_packets; |
| 167 | tx_packets = tstats->tx_packets; |
| 168 | rx_bytes = tstats->rx_bytes; |
| 169 | tx_bytes = tstats->tx_bytes; |
| 170 | } while (u64_stats_fetch_retry_bh(&tstats->syncp, start)); |
| 171 | |
| 172 | tot->rx_packets += rx_packets; |
| 173 | tot->tx_packets += tx_packets; |
| 174 | tot->rx_bytes += rx_bytes; |
| 175 | tot->tx_bytes += tx_bytes; |
| 176 | } |
| 177 | |
| 178 | tot->tx_fifo_errors = dev->stats.tx_fifo_errors; |
| 179 | tot->tx_carrier_errors = dev->stats.tx_carrier_errors; |
| 180 | tot->tx_dropped = dev->stats.tx_dropped; |
| 181 | tot->tx_aborted_errors = dev->stats.tx_aborted_errors; |
| 182 | tot->tx_errors = dev->stats.tx_errors; |
| 183 | tot->collisions = dev->stats.collisions; |
| 184 | |
| 185 | return tot; |
| 186 | } |
| 187 | |
| 188 | static struct ip_tunnel *ipip_tunnel_lookup(struct net *net, |
| 189 | __be32 remote, __be32 local) |
| 190 | { |
| 191 | unsigned int h0 = HASH(remote); |
| 192 | unsigned int h1 = HASH(local); |
| 193 | struct ip_tunnel *t; |
| 194 | struct ipip_net *ipn = net_generic(net, ipip_net_id); |
| 195 | |
| 196 | for_each_ip_tunnel_rcu(ipn->tunnels_r_l[h0 ^ h1]) |
| 197 | if (local == t->parms.iph.saddr && |
| 198 | remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP)) |
| 199 | return t; |
| 200 | |
| 201 | for_each_ip_tunnel_rcu(ipn->tunnels_r[h0]) |
| 202 | if (remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP)) |
| 203 | return t; |
| 204 | |
| 205 | for_each_ip_tunnel_rcu(ipn->tunnels_l[h1]) |
| 206 | if (local == t->parms.iph.saddr && (t->dev->flags&IFF_UP)) |
| 207 | return t; |
| 208 | |
| 209 | t = rcu_dereference(ipn->tunnels_wc[0]); |
| 210 | if (t && (t->dev->flags&IFF_UP)) |
| 211 | return t; |
| 212 | return NULL; |
| 213 | } |
| 214 | |
| 215 | static struct ip_tunnel __rcu **__ipip_bucket(struct ipip_net *ipn, |
| 216 | struct ip_tunnel_parm *parms) |
| 217 | { |
| 218 | __be32 remote = parms->iph.daddr; |
| 219 | __be32 local = parms->iph.saddr; |
| 220 | unsigned int h = 0; |
| 221 | int prio = 0; |
| 222 | |
| 223 | if (remote) { |
| 224 | prio |= 2; |
| 225 | h ^= HASH(remote); |
| 226 | } |
| 227 | if (local) { |
| 228 | prio |= 1; |
| 229 | h ^= HASH(local); |
| 230 | } |
| 231 | return &ipn->tunnels[prio][h]; |
| 232 | } |
| 233 | |
| 234 | static inline struct ip_tunnel __rcu **ipip_bucket(struct ipip_net *ipn, |
| 235 | struct ip_tunnel *t) |
| 236 | { |
| 237 | return __ipip_bucket(ipn, &t->parms); |
| 238 | } |
| 239 | |
| 240 | static void ipip_tunnel_unlink(struct ipip_net *ipn, struct ip_tunnel *t) |
| 241 | { |
| 242 | struct ip_tunnel __rcu **tp; |
| 243 | struct ip_tunnel *iter; |
| 244 | |
| 245 | for (tp = ipip_bucket(ipn, t); |
| 246 | (iter = rtnl_dereference(*tp)) != NULL; |
| 247 | tp = &iter->next) { |
| 248 | if (t == iter) { |
| 249 | rcu_assign_pointer(*tp, t->next); |
| 250 | break; |
| 251 | } |
| 252 | } |
| 253 | } |
| 254 | |
| 255 | static void ipip_tunnel_link(struct ipip_net *ipn, struct ip_tunnel *t) |
| 256 | { |
| 257 | struct ip_tunnel __rcu **tp = ipip_bucket(ipn, t); |
| 258 | |
| 259 | rcu_assign_pointer(t->next, rtnl_dereference(*tp)); |
| 260 | rcu_assign_pointer(*tp, t); |
| 261 | } |
| 262 | |
| 263 | static struct ip_tunnel *ipip_tunnel_locate(struct net *net, |
| 264 | struct ip_tunnel_parm *parms, int create) |
| 265 | { |
| 266 | __be32 remote = parms->iph.daddr; |
| 267 | __be32 local = parms->iph.saddr; |
| 268 | struct ip_tunnel *t, *nt; |
| 269 | struct ip_tunnel __rcu **tp; |
| 270 | struct net_device *dev; |
| 271 | char name[IFNAMSIZ]; |
| 272 | struct ipip_net *ipn = net_generic(net, ipip_net_id); |
| 273 | |
| 274 | for (tp = __ipip_bucket(ipn, parms); |
| 275 | (t = rtnl_dereference(*tp)) != NULL; |
| 276 | tp = &t->next) { |
| 277 | if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr) |
| 278 | return t; |
| 279 | } |
| 280 | if (!create) |
| 281 | return NULL; |
| 282 | |
| 283 | if (parms->name[0]) |
| 284 | strlcpy(name, parms->name, IFNAMSIZ); |
| 285 | else |
| 286 | strcpy(name, "tunl%d"); |
| 287 | |
| 288 | dev = alloc_netdev(sizeof(*t), name, ipip_tunnel_setup); |
| 289 | if (dev == NULL) |
| 290 | return NULL; |
| 291 | |
| 292 | dev_net_set(dev, net); |
| 293 | |
| 294 | nt = netdev_priv(dev); |
| 295 | nt->parms = *parms; |
| 296 | |
| 297 | if (ipip_tunnel_init(dev) < 0) |
| 298 | goto failed_free; |
| 299 | |
| 300 | if (register_netdevice(dev) < 0) |
| 301 | goto failed_free; |
| 302 | |
| 303 | strcpy(nt->parms.name, dev->name); |
| 304 | |
| 305 | dev_hold(dev); |
| 306 | ipip_tunnel_link(ipn, nt); |
| 307 | return nt; |
| 308 | |
| 309 | failed_free: |
| 310 | ipip_dev_free(dev); |
| 311 | return NULL; |
| 312 | } |
| 313 | |
| 314 | /* called with RTNL */ |
| 315 | static void ipip_tunnel_uninit(struct net_device *dev) |
| 316 | { |
| 317 | struct net *net = dev_net(dev); |
| 318 | struct ipip_net *ipn = net_generic(net, ipip_net_id); |
| 319 | |
| 320 | if (dev == ipn->fb_tunnel_dev) |
| 321 | RCU_INIT_POINTER(ipn->tunnels_wc[0], NULL); |
| 322 | else |
| 323 | ipip_tunnel_unlink(ipn, netdev_priv(dev)); |
| 324 | dev_put(dev); |
| 325 | } |
| 326 | |
| 327 | static int ipip_err(struct sk_buff *skb, u32 info) |
| 328 | { |
| 329 | |
| 330 | /* All the routers (except for Linux) return only |
| 331 | 8 bytes of packet payload. It means, that precise relaying of |
| 332 | ICMP in the real Internet is absolutely infeasible. |
| 333 | */ |
| 334 | const struct iphdr *iph = (const struct iphdr *)skb->data; |
| 335 | const int type = icmp_hdr(skb)->type; |
| 336 | const int code = icmp_hdr(skb)->code; |
| 337 | struct ip_tunnel *t; |
| 338 | int err; |
| 339 | |
| 340 | switch (type) { |
| 341 | default: |
| 342 | case ICMP_PARAMETERPROB: |
| 343 | return 0; |
| 344 | |
| 345 | case ICMP_DEST_UNREACH: |
| 346 | switch (code) { |
| 347 | case ICMP_SR_FAILED: |
| 348 | case ICMP_PORT_UNREACH: |
| 349 | /* Impossible event. */ |
| 350 | return 0; |
| 351 | case ICMP_FRAG_NEEDED: |
| 352 | /* Soft state for pmtu is maintained by IP core. */ |
| 353 | return 0; |
| 354 | default: |
| 355 | /* All others are translated to HOST_UNREACH. |
| 356 | rfc2003 contains "deep thoughts" about NET_UNREACH, |
| 357 | I believe they are just ether pollution. --ANK |
| 358 | */ |
| 359 | break; |
| 360 | } |
| 361 | break; |
| 362 | case ICMP_TIME_EXCEEDED: |
| 363 | if (code != ICMP_EXC_TTL) |
| 364 | return 0; |
| 365 | break; |
| 366 | } |
| 367 | |
| 368 | err = -ENOENT; |
| 369 | |
| 370 | rcu_read_lock(); |
| 371 | t = ipip_tunnel_lookup(dev_net(skb->dev), iph->daddr, iph->saddr); |
| 372 | if (t == NULL || t->parms.iph.daddr == 0) |
| 373 | goto out; |
| 374 | |
| 375 | err = 0; |
| 376 | if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) |
| 377 | goto out; |
| 378 | |
| 379 | if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) |
| 380 | t->err_count++; |
| 381 | else |
| 382 | t->err_count = 1; |
| 383 | t->err_time = jiffies; |
| 384 | out: |
| 385 | rcu_read_unlock(); |
| 386 | return err; |
| 387 | } |
| 388 | |
| 389 | static inline void ipip_ecn_decapsulate(const struct iphdr *outer_iph, |
| 390 | struct sk_buff *skb) |
| 391 | { |
| 392 | struct iphdr *inner_iph = ip_hdr(skb); |
| 393 | |
| 394 | if (INET_ECN_is_ce(outer_iph->tos)) |
| 395 | IP_ECN_set_ce(inner_iph); |
| 396 | } |
| 397 | |
| 398 | static int ipip_rcv(struct sk_buff *skb) |
| 399 | { |
| 400 | struct ip_tunnel *tunnel; |
| 401 | const struct iphdr *iph = ip_hdr(skb); |
| 402 | |
| 403 | rcu_read_lock(); |
| 404 | tunnel = ipip_tunnel_lookup(dev_net(skb->dev), iph->saddr, iph->daddr); |
| 405 | if (tunnel != NULL) { |
| 406 | struct pcpu_tstats *tstats; |
| 407 | |
| 408 | if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { |
| 409 | rcu_read_unlock(); |
| 410 | kfree_skb(skb); |
| 411 | return 0; |
| 412 | } |
| 413 | |
| 414 | secpath_reset(skb); |
| 415 | |
| 416 | skb->mac_header = skb->network_header; |
| 417 | skb_reset_network_header(skb); |
| 418 | skb->protocol = htons(ETH_P_IP); |
| 419 | skb->pkt_type = PACKET_HOST; |
| 420 | |
| 421 | tstats = this_cpu_ptr(tunnel->dev->tstats); |
| 422 | u64_stats_update_begin(&tstats->syncp); |
| 423 | tstats->rx_packets++; |
| 424 | tstats->rx_bytes += skb->len; |
| 425 | u64_stats_update_end(&tstats->syncp); |
| 426 | |
| 427 | __skb_tunnel_rx(skb, tunnel->dev); |
| 428 | |
| 429 | ipip_ecn_decapsulate(iph, skb); |
| 430 | |
| 431 | netif_rx(skb); |
| 432 | |
| 433 | rcu_read_unlock(); |
| 434 | return 0; |
| 435 | } |
| 436 | rcu_read_unlock(); |
| 437 | |
| 438 | return -1; |
| 439 | } |
| 440 | |
| 441 | /* |
| 442 | * This function assumes it is being called from dev_queue_xmit() |
| 443 | * and that skb is filled properly by that function. |
| 444 | */ |
| 445 | |
| 446 | static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) |
| 447 | { |
| 448 | struct ip_tunnel *tunnel = netdev_priv(dev); |
| 449 | struct pcpu_tstats *tstats; |
| 450 | const struct iphdr *tiph = &tunnel->parms.iph; |
| 451 | u8 tos = tunnel->parms.iph.tos; |
| 452 | __be16 df = tiph->frag_off; |
| 453 | struct rtable *rt; /* Route to the other host */ |
| 454 | struct net_device *tdev; /* Device to other host */ |
| 455 | const struct iphdr *old_iph = ip_hdr(skb); |
| 456 | struct iphdr *iph; /* Our new IP header */ |
| 457 | unsigned int max_headroom; /* The extra header space needed */ |
| 458 | __be32 dst = tiph->daddr; |
| 459 | struct flowi4 fl4; |
| 460 | int mtu; |
| 461 | |
| 462 | if (skb->protocol != htons(ETH_P_IP)) |
| 463 | goto tx_error; |
| 464 | |
| 465 | if (tos & 1) |
| 466 | tos = old_iph->tos; |
| 467 | |
| 468 | if (!dst) { |
| 469 | /* NBMA tunnel */ |
| 470 | if ((rt = skb_rtable(skb)) == NULL) { |
| 471 | dev->stats.tx_fifo_errors++; |
| 472 | goto tx_error; |
| 473 | } |
| 474 | dst = rt->rt_gateway; |
| 475 | } |
| 476 | |
| 477 | rt = ip_route_output_ports(dev_net(dev), &fl4, NULL, |
| 478 | dst, tiph->saddr, |
| 479 | 0, 0, |
| 480 | IPPROTO_IPIP, RT_TOS(tos), |
| 481 | tunnel->parms.link); |
| 482 | if (IS_ERR(rt)) { |
| 483 | dev->stats.tx_carrier_errors++; |
| 484 | goto tx_error_icmp; |
| 485 | } |
| 486 | tdev = rt->dst.dev; |
| 487 | |
| 488 | if (tdev == dev) { |
| 489 | ip_rt_put(rt); |
| 490 | dev->stats.collisions++; |
| 491 | goto tx_error; |
| 492 | } |
| 493 | |
| 494 | df |= old_iph->frag_off & htons(IP_DF); |
| 495 | |
| 496 | if (df) { |
| 497 | mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr); |
| 498 | |
| 499 | if (mtu < 68) { |
| 500 | dev->stats.collisions++; |
| 501 | ip_rt_put(rt); |
| 502 | goto tx_error; |
| 503 | } |
| 504 | |
| 505 | if (skb_dst(skb)) |
| 506 | skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu); |
| 507 | |
| 508 | if ((old_iph->frag_off & htons(IP_DF)) && |
| 509 | mtu < ntohs(old_iph->tot_len)) { |
| 510 | icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, |
| 511 | htonl(mtu)); |
| 512 | ip_rt_put(rt); |
| 513 | goto tx_error; |
| 514 | } |
| 515 | } |
| 516 | |
| 517 | if (tunnel->err_count > 0) { |
| 518 | if (time_before(jiffies, |
| 519 | tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { |
| 520 | tunnel->err_count--; |
| 521 | dst_link_failure(skb); |
| 522 | } else |
| 523 | tunnel->err_count = 0; |
| 524 | } |
| 525 | |
| 526 | /* |
| 527 | * Okay, now see if we can stuff it in the buffer as-is. |
| 528 | */ |
| 529 | max_headroom = (LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr)); |
| 530 | |
| 531 | if (skb_headroom(skb) < max_headroom || skb_shared(skb) || |
| 532 | (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { |
| 533 | struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); |
| 534 | if (!new_skb) { |
| 535 | ip_rt_put(rt); |
| 536 | dev->stats.tx_dropped++; |
| 537 | dev_kfree_skb(skb); |
| 538 | return NETDEV_TX_OK; |
| 539 | } |
| 540 | if (skb->sk) |
| 541 | skb_set_owner_w(new_skb, skb->sk); |
| 542 | dev_kfree_skb(skb); |
| 543 | skb = new_skb; |
| 544 | old_iph = ip_hdr(skb); |
| 545 | } |
| 546 | |
| 547 | skb->transport_header = skb->network_header; |
| 548 | skb_push(skb, sizeof(struct iphdr)); |
| 549 | skb_reset_network_header(skb); |
| 550 | memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); |
| 551 | IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | |
| 552 | IPSKB_REROUTED); |
| 553 | skb_dst_drop(skb); |
| 554 | skb_dst_set(skb, &rt->dst); |
| 555 | |
| 556 | /* |
| 557 | * Push down and install the IPIP header. |
| 558 | */ |
| 559 | |
| 560 | iph = ip_hdr(skb); |
| 561 | iph->version = 4; |
| 562 | iph->ihl = sizeof(struct iphdr)>>2; |
| 563 | iph->frag_off = df; |
| 564 | iph->protocol = IPPROTO_IPIP; |
| 565 | iph->tos = INET_ECN_encapsulate(tos, old_iph->tos); |
| 566 | iph->daddr = fl4.daddr; |
| 567 | iph->saddr = fl4.saddr; |
| 568 | |
| 569 | if ((iph->ttl = tiph->ttl) == 0) |
| 570 | iph->ttl = old_iph->ttl; |
| 571 | |
| 572 | nf_reset(skb); |
| 573 | tstats = this_cpu_ptr(dev->tstats); |
| 574 | __IPTUNNEL_XMIT(tstats, &dev->stats); |
| 575 | return NETDEV_TX_OK; |
| 576 | |
| 577 | tx_error_icmp: |
| 578 | dst_link_failure(skb); |
| 579 | tx_error: |
| 580 | dev->stats.tx_errors++; |
| 581 | dev_kfree_skb(skb); |
| 582 | return NETDEV_TX_OK; |
| 583 | } |
| 584 | |
| 585 | static void ipip_tunnel_bind_dev(struct net_device *dev) |
| 586 | { |
| 587 | struct net_device *tdev = NULL; |
| 588 | struct ip_tunnel *tunnel; |
| 589 | const struct iphdr *iph; |
| 590 | |
| 591 | tunnel = netdev_priv(dev); |
| 592 | iph = &tunnel->parms.iph; |
| 593 | |
| 594 | if (iph->daddr) { |
| 595 | struct rtable *rt; |
| 596 | struct flowi4 fl4; |
| 597 | |
| 598 | rt = ip_route_output_ports(dev_net(dev), &fl4, NULL, |
| 599 | iph->daddr, iph->saddr, |
| 600 | 0, 0, |
| 601 | IPPROTO_IPIP, |
| 602 | RT_TOS(iph->tos), |
| 603 | tunnel->parms.link); |
| 604 | if (!IS_ERR(rt)) { |
| 605 | tdev = rt->dst.dev; |
| 606 | ip_rt_put(rt); |
| 607 | } |
| 608 | dev->flags |= IFF_POINTOPOINT; |
| 609 | } |
| 610 | |
| 611 | if (!tdev && tunnel->parms.link) |
| 612 | tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link); |
| 613 | |
| 614 | if (tdev) { |
| 615 | dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); |
| 616 | dev->mtu = tdev->mtu - sizeof(struct iphdr); |
| 617 | } |
| 618 | dev->iflink = tunnel->parms.link; |
| 619 | } |
| 620 | |
| 621 | static int |
| 622 | ipip_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) |
| 623 | { |
| 624 | int err = 0; |
| 625 | struct ip_tunnel_parm p; |
| 626 | struct ip_tunnel *t; |
| 627 | struct net *net = dev_net(dev); |
| 628 | struct ipip_net *ipn = net_generic(net, ipip_net_id); |
| 629 | |
| 630 | switch (cmd) { |
| 631 | case SIOCGETTUNNEL: |
| 632 | t = NULL; |
| 633 | if (dev == ipn->fb_tunnel_dev) { |
| 634 | if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { |
| 635 | err = -EFAULT; |
| 636 | break; |
| 637 | } |
| 638 | t = ipip_tunnel_locate(net, &p, 0); |
| 639 | } |
| 640 | if (t == NULL) |
| 641 | t = netdev_priv(dev); |
| 642 | memcpy(&p, &t->parms, sizeof(p)); |
| 643 | if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) |
| 644 | err = -EFAULT; |
| 645 | break; |
| 646 | |
| 647 | case SIOCADDTUNNEL: |
| 648 | case SIOCCHGTUNNEL: |
| 649 | err = -EPERM; |
| 650 | if (!capable(CAP_NET_ADMIN)) |
| 651 | goto done; |
| 652 | |
| 653 | err = -EFAULT; |
| 654 | if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) |
| 655 | goto done; |
| 656 | |
| 657 | err = -EINVAL; |
| 658 | if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP || |
| 659 | p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) |
| 660 | goto done; |
| 661 | if (p.iph.ttl) |
| 662 | p.iph.frag_off |= htons(IP_DF); |
| 663 | |
| 664 | t = ipip_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL); |
| 665 | |
| 666 | if (dev != ipn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { |
| 667 | if (t != NULL) { |
| 668 | if (t->dev != dev) { |
| 669 | err = -EEXIST; |
| 670 | break; |
| 671 | } |
| 672 | } else { |
| 673 | if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || |
| 674 | (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { |
| 675 | err = -EINVAL; |
| 676 | break; |
| 677 | } |
| 678 | t = netdev_priv(dev); |
| 679 | ipip_tunnel_unlink(ipn, t); |
| 680 | synchronize_net(); |
| 681 | t->parms.iph.saddr = p.iph.saddr; |
| 682 | t->parms.iph.daddr = p.iph.daddr; |
| 683 | memcpy(dev->dev_addr, &p.iph.saddr, 4); |
| 684 | memcpy(dev->broadcast, &p.iph.daddr, 4); |
| 685 | ipip_tunnel_link(ipn, t); |
| 686 | netdev_state_change(dev); |
| 687 | } |
| 688 | } |
| 689 | |
| 690 | if (t) { |
| 691 | err = 0; |
| 692 | if (cmd == SIOCCHGTUNNEL) { |
| 693 | t->parms.iph.ttl = p.iph.ttl; |
| 694 | t->parms.iph.tos = p.iph.tos; |
| 695 | t->parms.iph.frag_off = p.iph.frag_off; |
| 696 | if (t->parms.link != p.link) { |
| 697 | t->parms.link = p.link; |
| 698 | ipip_tunnel_bind_dev(dev); |
| 699 | netdev_state_change(dev); |
| 700 | } |
| 701 | } |
| 702 | if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) |
| 703 | err = -EFAULT; |
| 704 | } else |
| 705 | err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); |
| 706 | break; |
| 707 | |
| 708 | case SIOCDELTUNNEL: |
| 709 | err = -EPERM; |
| 710 | if (!capable(CAP_NET_ADMIN)) |
| 711 | goto done; |
| 712 | |
| 713 | if (dev == ipn->fb_tunnel_dev) { |
| 714 | err = -EFAULT; |
| 715 | if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) |
| 716 | goto done; |
| 717 | err = -ENOENT; |
| 718 | if ((t = ipip_tunnel_locate(net, &p, 0)) == NULL) |
| 719 | goto done; |
| 720 | err = -EPERM; |
| 721 | if (t->dev == ipn->fb_tunnel_dev) |
| 722 | goto done; |
| 723 | dev = t->dev; |
| 724 | } |
| 725 | unregister_netdevice(dev); |
| 726 | err = 0; |
| 727 | break; |
| 728 | |
| 729 | default: |
| 730 | err = -EINVAL; |
| 731 | } |
| 732 | |
| 733 | done: |
| 734 | return err; |
| 735 | } |
| 736 | |
| 737 | static int ipip_tunnel_change_mtu(struct net_device *dev, int new_mtu) |
| 738 | { |
| 739 | if (new_mtu < 68 || new_mtu > 0xFFF8 - sizeof(struct iphdr)) |
| 740 | return -EINVAL; |
| 741 | dev->mtu = new_mtu; |
| 742 | return 0; |
| 743 | } |
| 744 | |
| 745 | static const struct net_device_ops ipip_netdev_ops = { |
| 746 | .ndo_uninit = ipip_tunnel_uninit, |
| 747 | .ndo_start_xmit = ipip_tunnel_xmit, |
| 748 | .ndo_do_ioctl = ipip_tunnel_ioctl, |
| 749 | .ndo_change_mtu = ipip_tunnel_change_mtu, |
| 750 | .ndo_get_stats64 = ipip_get_stats64, |
| 751 | }; |
| 752 | |
| 753 | static void ipip_dev_free(struct net_device *dev) |
| 754 | { |
| 755 | free_percpu(dev->tstats); |
| 756 | free_netdev(dev); |
| 757 | } |
| 758 | |
| 759 | static void ipip_tunnel_setup(struct net_device *dev) |
| 760 | { |
| 761 | dev->netdev_ops = &ipip_netdev_ops; |
| 762 | dev->destructor = ipip_dev_free; |
| 763 | |
| 764 | dev->type = ARPHRD_TUNNEL; |
| 765 | dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); |
| 766 | dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr); |
| 767 | dev->flags = IFF_NOARP; |
| 768 | dev->iflink = 0; |
| 769 | dev->addr_len = 4; |
| 770 | dev->features |= NETIF_F_NETNS_LOCAL; |
| 771 | dev->features |= NETIF_F_LLTX; |
| 772 | dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; |
| 773 | } |
| 774 | |
| 775 | static int ipip_tunnel_init(struct net_device *dev) |
| 776 | { |
| 777 | struct ip_tunnel *tunnel = netdev_priv(dev); |
| 778 | |
| 779 | tunnel->dev = dev; |
| 780 | |
| 781 | memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); |
| 782 | memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); |
| 783 | |
| 784 | ipip_tunnel_bind_dev(dev); |
| 785 | |
| 786 | dev->tstats = alloc_percpu(struct pcpu_tstats); |
| 787 | if (!dev->tstats) |
| 788 | return -ENOMEM; |
| 789 | |
| 790 | return 0; |
| 791 | } |
| 792 | |
| 793 | static int __net_init ipip_fb_tunnel_init(struct net_device *dev) |
| 794 | { |
| 795 | struct ip_tunnel *tunnel = netdev_priv(dev); |
| 796 | struct iphdr *iph = &tunnel->parms.iph; |
| 797 | struct ipip_net *ipn = net_generic(dev_net(dev), ipip_net_id); |
| 798 | |
| 799 | tunnel->dev = dev; |
| 800 | strcpy(tunnel->parms.name, dev->name); |
| 801 | |
| 802 | iph->version = 4; |
| 803 | iph->protocol = IPPROTO_IPIP; |
| 804 | iph->ihl = 5; |
| 805 | |
| 806 | dev->tstats = alloc_percpu(struct pcpu_tstats); |
| 807 | if (!dev->tstats) |
| 808 | return -ENOMEM; |
| 809 | |
| 810 | dev_hold(dev); |
| 811 | rcu_assign_pointer(ipn->tunnels_wc[0], tunnel); |
| 812 | return 0; |
| 813 | } |
| 814 | |
| 815 | static struct xfrm_tunnel ipip_handler __read_mostly = { |
| 816 | .handler = ipip_rcv, |
| 817 | .err_handler = ipip_err, |
| 818 | .priority = 1, |
| 819 | }; |
| 820 | |
| 821 | static const char banner[] __initconst = |
| 822 | KERN_INFO "IPv4 over IPv4 tunneling driver\n"; |
| 823 | |
| 824 | static void ipip_destroy_tunnels(struct ipip_net *ipn, struct list_head *head) |
| 825 | { |
| 826 | int prio; |
| 827 | |
| 828 | for (prio = 1; prio < 4; prio++) { |
| 829 | int h; |
| 830 | for (h = 0; h < HASH_SIZE; h++) { |
| 831 | struct ip_tunnel *t; |
| 832 | |
| 833 | t = rtnl_dereference(ipn->tunnels[prio][h]); |
| 834 | while (t != NULL) { |
| 835 | unregister_netdevice_queue(t->dev, head); |
| 836 | t = rtnl_dereference(t->next); |
| 837 | } |
| 838 | } |
| 839 | } |
| 840 | } |
| 841 | |
| 842 | static int __net_init ipip_init_net(struct net *net) |
| 843 | { |
| 844 | struct ipip_net *ipn = net_generic(net, ipip_net_id); |
| 845 | struct ip_tunnel *t; |
| 846 | int err; |
| 847 | |
| 848 | ipn->tunnels[0] = ipn->tunnels_wc; |
| 849 | ipn->tunnels[1] = ipn->tunnels_l; |
| 850 | ipn->tunnels[2] = ipn->tunnels_r; |
| 851 | ipn->tunnels[3] = ipn->tunnels_r_l; |
| 852 | |
| 853 | ipn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), |
| 854 | "tunl0", |
| 855 | ipip_tunnel_setup); |
| 856 | if (!ipn->fb_tunnel_dev) { |
| 857 | err = -ENOMEM; |
| 858 | goto err_alloc_dev; |
| 859 | } |
| 860 | dev_net_set(ipn->fb_tunnel_dev, net); |
| 861 | |
| 862 | err = ipip_fb_tunnel_init(ipn->fb_tunnel_dev); |
| 863 | if (err) |
| 864 | goto err_reg_dev; |
| 865 | |
| 866 | if ((err = register_netdev(ipn->fb_tunnel_dev))) |
| 867 | goto err_reg_dev; |
| 868 | |
| 869 | t = netdev_priv(ipn->fb_tunnel_dev); |
| 870 | |
| 871 | strcpy(t->parms.name, ipn->fb_tunnel_dev->name); |
| 872 | return 0; |
| 873 | |
| 874 | err_reg_dev: |
| 875 | ipip_dev_free(ipn->fb_tunnel_dev); |
| 876 | err_alloc_dev: |
| 877 | /* nothing */ |
| 878 | return err; |
| 879 | } |
| 880 | |
| 881 | static void __net_exit ipip_exit_net(struct net *net) |
| 882 | { |
| 883 | struct ipip_net *ipn = net_generic(net, ipip_net_id); |
| 884 | LIST_HEAD(list); |
| 885 | |
| 886 | rtnl_lock(); |
| 887 | ipip_destroy_tunnels(ipn, &list); |
| 888 | unregister_netdevice_queue(ipn->fb_tunnel_dev, &list); |
| 889 | unregister_netdevice_many(&list); |
| 890 | rtnl_unlock(); |
| 891 | } |
| 892 | |
| 893 | static struct pernet_operations ipip_net_ops = { |
| 894 | .init = ipip_init_net, |
| 895 | .exit = ipip_exit_net, |
| 896 | .id = &ipip_net_id, |
| 897 | .size = sizeof(struct ipip_net), |
| 898 | }; |
| 899 | |
| 900 | static int __init ipip_init(void) |
| 901 | { |
| 902 | int err; |
| 903 | |
| 904 | printk(banner); |
| 905 | |
| 906 | err = register_pernet_device(&ipip_net_ops); |
| 907 | if (err < 0) |
| 908 | return err; |
| 909 | err = xfrm4_tunnel_register(&ipip_handler, AF_INET); |
| 910 | if (err < 0) { |
| 911 | unregister_pernet_device(&ipip_net_ops); |
| 912 | pr_info("%s: can't register tunnel\n", __func__); |
| 913 | } |
| 914 | return err; |
| 915 | } |
| 916 | |
| 917 | static void __exit ipip_fini(void) |
| 918 | { |
| 919 | if (xfrm4_tunnel_deregister(&ipip_handler, AF_INET)) |
| 920 | pr_info("%s: can't deregister tunnel\n", __func__); |
| 921 | |
| 922 | unregister_pernet_device(&ipip_net_ops); |
| 923 | } |
| 924 | |
| 925 | module_init(ipip_init); |
| 926 | module_exit(ipip_fini); |
| 927 | MODULE_LICENSE("GPL"); |
| 928 | MODULE_ALIAS_NETDEV("tunl0"); |