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 <asm/uaccess.h> 99 #include <linux/skbuff.h> 100 #include <linux/netdevice.h> 101 #include <linux/in.h> 102 #include <linux/tcp.h> 103 #include <linux/udp.h> 104 #include <linux/if_arp.h> 105 #include <linux/mroute.h> 106 #include <linux/init.h> 107 #include <linux/netfilter_ipv4.h> 108 #include <linux/if_ether.h> 109 110 #include <net/sock.h> 111 #include <net/ip.h> 112 #include <net/icmp.h> 113 #include <net/ipip.h> 114 #include <net/inet_ecn.h> 115 #include <net/xfrm.h> 116 #include <net/net_namespace.h> 117 #include <net/netns/generic.h> 118 119 #define HASH_SIZE 16 120 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF) 121 122 static int ipip_net_id; 123 struct ipip_net { 124 struct ip_tunnel *tunnels_r_l[HASH_SIZE]; 125 struct ip_tunnel *tunnels_r[HASH_SIZE]; 126 struct ip_tunnel *tunnels_l[HASH_SIZE]; 127 struct ip_tunnel *tunnels_wc[1]; 128 struct ip_tunnel **tunnels[4]; 129 130 struct net_device *fb_tunnel_dev; 131 }; 132 133 static void ipip_fb_tunnel_init(struct net_device *dev); 134 static void ipip_tunnel_init(struct net_device *dev); 135 static void ipip_tunnel_setup(struct net_device *dev); 136 137 static DEFINE_RWLOCK(ipip_lock); 138 139 static struct ip_tunnel * ipip_tunnel_lookup(struct net *net, 140 __be32 remote, __be32 local) 141 { 142 unsigned h0 = HASH(remote); 143 unsigned h1 = HASH(local); 144 struct ip_tunnel *t; 145 struct ipip_net *ipn = net_generic(net, ipip_net_id); 146 147 for (t = ipn->tunnels_r_l[h0^h1]; t; t = t->next) { 148 if (local == t->parms.iph.saddr && 149 remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP)) 150 return t; 151 } 152 for (t = ipn->tunnels_r[h0]; t; t = t->next) { 153 if (remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP)) 154 return t; 155 } 156 for (t = ipn->tunnels_l[h1]; t; t = t->next) { 157 if (local == t->parms.iph.saddr && (t->dev->flags&IFF_UP)) 158 return t; 159 } 160 if ((t = ipn->tunnels_wc[0]) != NULL && (t->dev->flags&IFF_UP)) 161 return t; 162 return NULL; 163 } 164 165 static struct ip_tunnel **__ipip_bucket(struct ipip_net *ipn, 166 struct ip_tunnel_parm *parms) 167 { 168 __be32 remote = parms->iph.daddr; 169 __be32 local = parms->iph.saddr; 170 unsigned h = 0; 171 int prio = 0; 172 173 if (remote) { 174 prio |= 2; 175 h ^= HASH(remote); 176 } 177 if (local) { 178 prio |= 1; 179 h ^= HASH(local); 180 } 181 return &ipn->tunnels[prio][h]; 182 } 183 184 static inline struct ip_tunnel **ipip_bucket(struct ipip_net *ipn, 185 struct ip_tunnel *t) 186 { 187 return __ipip_bucket(ipn, &t->parms); 188 } 189 190 static void ipip_tunnel_unlink(struct ipip_net *ipn, struct ip_tunnel *t) 191 { 192 struct ip_tunnel **tp; 193 194 for (tp = ipip_bucket(ipn, t); *tp; tp = &(*tp)->next) { 195 if (t == *tp) { 196 write_lock_bh(&ipip_lock); 197 *tp = t->next; 198 write_unlock_bh(&ipip_lock); 199 break; 200 } 201 } 202 } 203 204 static void ipip_tunnel_link(struct ipip_net *ipn, struct ip_tunnel *t) 205 { 206 struct ip_tunnel **tp = ipip_bucket(ipn, t); 207 208 t->next = *tp; 209 write_lock_bh(&ipip_lock); 210 *tp = t; 211 write_unlock_bh(&ipip_lock); 212 } 213 214 static struct ip_tunnel * ipip_tunnel_locate(struct net *net, 215 struct ip_tunnel_parm *parms, int create) 216 { 217 __be32 remote = parms->iph.daddr; 218 __be32 local = parms->iph.saddr; 219 struct ip_tunnel *t, **tp, *nt; 220 struct net_device *dev; 221 char name[IFNAMSIZ]; 222 struct ipip_net *ipn = net_generic(net, ipip_net_id); 223 224 for (tp = __ipip_bucket(ipn, parms); (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 sprintf(name, "tunl%%d"); 235 236 dev = alloc_netdev(sizeof(*t), name, ipip_tunnel_setup); 237 if (dev == NULL) 238 return NULL; 239 240 dev_net_set(dev, net); 241 242 if (strchr(name, '%')) { 243 if (dev_alloc_name(dev, name) < 0) 244 goto failed_free; 245 } 246 247 nt = netdev_priv(dev); 248 nt->parms = *parms; 249 250 ipip_tunnel_init(dev); 251 252 if (register_netdevice(dev) < 0) 253 goto failed_free; 254 255 dev_hold(dev); 256 ipip_tunnel_link(ipn, nt); 257 return nt; 258 259 failed_free: 260 free_netdev(dev); 261 return NULL; 262 } 263 264 static void ipip_tunnel_uninit(struct net_device *dev) 265 { 266 struct net *net = dev_net(dev); 267 struct ipip_net *ipn = net_generic(net, ipip_net_id); 268 269 if (dev == ipn->fb_tunnel_dev) { 270 write_lock_bh(&ipip_lock); 271 ipn->tunnels_wc[0] = NULL; 272 write_unlock_bh(&ipip_lock); 273 } else 274 ipip_tunnel_unlink(ipn, netdev_priv(dev)); 275 dev_put(dev); 276 } 277 278 static int ipip_err(struct sk_buff *skb, u32 info) 279 { 280 281 /* 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 const int type = icmp_hdr(skb)->type; 287 const int code = icmp_hdr(skb)->code; 288 struct ip_tunnel *t; 289 int err; 290 291 switch (type) { 292 default: 293 case ICMP_PARAMETERPROB: 294 return 0; 295 296 case ICMP_DEST_UNREACH: 297 switch (code) { 298 case ICMP_SR_FAILED: 299 case ICMP_PORT_UNREACH: 300 /* Impossible event. */ 301 return 0; 302 case ICMP_FRAG_NEEDED: 303 /* Soft state for pmtu is maintained by IP core. */ 304 return 0; 305 default: 306 /* All others are translated to HOST_UNREACH. 307 rfc2003 contains "deep thoughts" about NET_UNREACH, 308 I believe they are just ether pollution. --ANK 309 */ 310 break; 311 } 312 break; 313 case ICMP_TIME_EXCEEDED: 314 if (code != ICMP_EXC_TTL) 315 return 0; 316 break; 317 } 318 319 err = -ENOENT; 320 321 read_lock(&ipip_lock); 322 t = ipip_tunnel_lookup(dev_net(skb->dev), iph->daddr, iph->saddr); 323 if (t == NULL || t->parms.iph.daddr == 0) 324 goto out; 325 326 err = 0; 327 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 328 goto out; 329 330 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) 331 t->err_count++; 332 else 333 t->err_count = 1; 334 t->err_time = jiffies; 335 out: 336 read_unlock(&ipip_lock); 337 return err; 338 } 339 340 static inline void ipip_ecn_decapsulate(const struct iphdr *outer_iph, 341 struct sk_buff *skb) 342 { 343 struct iphdr *inner_iph = ip_hdr(skb); 344 345 if (INET_ECN_is_ce(outer_iph->tos)) 346 IP_ECN_set_ce(inner_iph); 347 } 348 349 static int ipip_rcv(struct sk_buff *skb) 350 { 351 struct ip_tunnel *tunnel; 352 const struct iphdr *iph = ip_hdr(skb); 353 354 read_lock(&ipip_lock); 355 if ((tunnel = ipip_tunnel_lookup(dev_net(skb->dev), 356 iph->saddr, iph->daddr)) != NULL) { 357 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { 358 read_unlock(&ipip_lock); 359 kfree_skb(skb); 360 return 0; 361 } 362 363 secpath_reset(skb); 364 365 skb->mac_header = skb->network_header; 366 skb_reset_network_header(skb); 367 skb->protocol = htons(ETH_P_IP); 368 skb->pkt_type = PACKET_HOST; 369 370 tunnel->dev->stats.rx_packets++; 371 tunnel->dev->stats.rx_bytes += skb->len; 372 skb->dev = tunnel->dev; 373 skb_dst_drop(skb); 374 nf_reset(skb); 375 ipip_ecn_decapsulate(iph, skb); 376 netif_rx(skb); 377 read_unlock(&ipip_lock); 378 return 0; 379 } 380 read_unlock(&ipip_lock); 381 382 return -1; 383 } 384 385 /* 386 * This function assumes it is being called from dev_queue_xmit() 387 * and that skb is filled properly by that function. 388 */ 389 390 static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) 391 { 392 struct ip_tunnel *tunnel = netdev_priv(dev); 393 struct net_device_stats *stats = &tunnel->dev->stats; 394 struct iphdr *tiph = &tunnel->parms.iph; 395 u8 tos = tunnel->parms.iph.tos; 396 __be16 df = tiph->frag_off; 397 struct rtable *rt; /* Route to the other host */ 398 struct net_device *tdev; /* Device to other host */ 399 struct iphdr *old_iph = ip_hdr(skb); 400 struct iphdr *iph; /* Our new IP header */ 401 unsigned int max_headroom; /* The extra header space needed */ 402 __be32 dst = tiph->daddr; 403 int mtu; 404 405 if (tunnel->recursion++) { 406 stats->collisions++; 407 goto tx_error; 408 } 409 410 if (skb->protocol != htons(ETH_P_IP)) 411 goto tx_error; 412 413 if (tos&1) 414 tos = old_iph->tos; 415 416 if (!dst) { 417 /* NBMA tunnel */ 418 if ((rt = skb_rtable(skb)) == NULL) { 419 stats->tx_fifo_errors++; 420 goto tx_error; 421 } 422 if ((dst = rt->rt_gateway) == 0) 423 goto tx_error_icmp; 424 } 425 426 { 427 struct flowi fl = { .oif = tunnel->parms.link, 428 .nl_u = { .ip4_u = 429 { .daddr = dst, 430 .saddr = tiph->saddr, 431 .tos = RT_TOS(tos) } }, 432 .proto = IPPROTO_IPIP }; 433 if (ip_route_output_key(dev_net(dev), &rt, &fl)) { 434 stats->tx_carrier_errors++; 435 goto tx_error_icmp; 436 } 437 } 438 tdev = rt->u.dst.dev; 439 440 if (tdev == dev) { 441 ip_rt_put(rt); 442 stats->collisions++; 443 goto tx_error; 444 } 445 446 if (tiph->frag_off) 447 mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr); 448 else 449 mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu; 450 451 if (mtu < 68) { 452 stats->collisions++; 453 ip_rt_put(rt); 454 goto tx_error; 455 } 456 if (skb_dst(skb)) 457 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu); 458 459 df |= (old_iph->frag_off&htons(IP_DF)); 460 461 if ((old_iph->frag_off&htons(IP_DF)) && mtu < ntohs(old_iph->tot_len)) { 462 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu)); 463 ip_rt_put(rt); 464 goto tx_error; 465 } 466 467 if (tunnel->err_count > 0) { 468 if (time_before(jiffies, 469 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { 470 tunnel->err_count--; 471 dst_link_failure(skb); 472 } else 473 tunnel->err_count = 0; 474 } 475 476 /* 477 * Okay, now see if we can stuff it in the buffer as-is. 478 */ 479 max_headroom = (LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr)); 480 481 if (skb_headroom(skb) < max_headroom || skb_shared(skb) || 482 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 483 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); 484 if (!new_skb) { 485 ip_rt_put(rt); 486 stats->tx_dropped++; 487 dev_kfree_skb(skb); 488 tunnel->recursion--; 489 return NETDEV_TX_OK; 490 } 491 if (skb->sk) 492 skb_set_owner_w(new_skb, skb->sk); 493 dev_kfree_skb(skb); 494 skb = new_skb; 495 old_iph = ip_hdr(skb); 496 } 497 498 skb->transport_header = skb->network_header; 499 skb_push(skb, sizeof(struct iphdr)); 500 skb_reset_network_header(skb); 501 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); 502 IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | 503 IPSKB_REROUTED); 504 skb_dst_drop(skb); 505 skb_dst_set(skb, &rt->u.dst); 506 507 /* 508 * Push down and install the IPIP header. 509 */ 510 511 iph = ip_hdr(skb); 512 iph->version = 4; 513 iph->ihl = sizeof(struct iphdr)>>2; 514 iph->frag_off = df; 515 iph->protocol = IPPROTO_IPIP; 516 iph->tos = INET_ECN_encapsulate(tos, old_iph->tos); 517 iph->daddr = rt->rt_dst; 518 iph->saddr = rt->rt_src; 519 520 if ((iph->ttl = tiph->ttl) == 0) 521 iph->ttl = old_iph->ttl; 522 523 nf_reset(skb); 524 525 IPTUNNEL_XMIT(); 526 tunnel->recursion--; 527 return NETDEV_TX_OK; 528 529 tx_error_icmp: 530 dst_link_failure(skb); 531 tx_error: 532 stats->tx_errors++; 533 dev_kfree_skb(skb); 534 tunnel->recursion--; 535 return NETDEV_TX_OK; 536 } 537 538 static void ipip_tunnel_bind_dev(struct net_device *dev) 539 { 540 struct net_device *tdev = NULL; 541 struct ip_tunnel *tunnel; 542 struct iphdr *iph; 543 544 tunnel = netdev_priv(dev); 545 iph = &tunnel->parms.iph; 546 547 if (iph->daddr) { 548 struct flowi fl = { .oif = tunnel->parms.link, 549 .nl_u = { .ip4_u = 550 { .daddr = iph->daddr, 551 .saddr = iph->saddr, 552 .tos = RT_TOS(iph->tos) } }, 553 .proto = IPPROTO_IPIP }; 554 struct rtable *rt; 555 if (!ip_route_output_key(dev_net(dev), &rt, &fl)) { 556 tdev = rt->u.dst.dev; 557 ip_rt_put(rt); 558 } 559 dev->flags |= IFF_POINTOPOINT; 560 } 561 562 if (!tdev && tunnel->parms.link) 563 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link); 564 565 if (tdev) { 566 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); 567 dev->mtu = tdev->mtu - sizeof(struct iphdr); 568 } 569 dev->iflink = tunnel->parms.link; 570 } 571 572 static int 573 ipip_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) 574 { 575 int err = 0; 576 struct ip_tunnel_parm p; 577 struct ip_tunnel *t; 578 struct net *net = dev_net(dev); 579 struct ipip_net *ipn = net_generic(net, ipip_net_id); 580 581 switch (cmd) { 582 case SIOCGETTUNNEL: 583 t = NULL; 584 if (dev == ipn->fb_tunnel_dev) { 585 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 586 err = -EFAULT; 587 break; 588 } 589 t = ipip_tunnel_locate(net, &p, 0); 590 } 591 if (t == NULL) 592 t = netdev_priv(dev); 593 memcpy(&p, &t->parms, sizeof(p)); 594 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 595 err = -EFAULT; 596 break; 597 598 case SIOCADDTUNNEL: 599 case SIOCCHGTUNNEL: 600 err = -EPERM; 601 if (!capable(CAP_NET_ADMIN)) 602 goto done; 603 604 err = -EFAULT; 605 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 606 goto done; 607 608 err = -EINVAL; 609 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP || 610 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) 611 goto done; 612 if (p.iph.ttl) 613 p.iph.frag_off |= htons(IP_DF); 614 615 t = ipip_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL); 616 617 if (dev != ipn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 618 if (t != NULL) { 619 if (t->dev != dev) { 620 err = -EEXIST; 621 break; 622 } 623 } else { 624 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || 625 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { 626 err = -EINVAL; 627 break; 628 } 629 t = netdev_priv(dev); 630 ipip_tunnel_unlink(ipn, t); 631 t->parms.iph.saddr = p.iph.saddr; 632 t->parms.iph.daddr = p.iph.daddr; 633 memcpy(dev->dev_addr, &p.iph.saddr, 4); 634 memcpy(dev->broadcast, &p.iph.daddr, 4); 635 ipip_tunnel_link(ipn, t); 636 netdev_state_change(dev); 637 } 638 } 639 640 if (t) { 641 err = 0; 642 if (cmd == SIOCCHGTUNNEL) { 643 t->parms.iph.ttl = p.iph.ttl; 644 t->parms.iph.tos = p.iph.tos; 645 t->parms.iph.frag_off = p.iph.frag_off; 646 if (t->parms.link != p.link) { 647 t->parms.link = p.link; 648 ipip_tunnel_bind_dev(dev); 649 netdev_state_change(dev); 650 } 651 } 652 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) 653 err = -EFAULT; 654 } else 655 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 656 break; 657 658 case SIOCDELTUNNEL: 659 err = -EPERM; 660 if (!capable(CAP_NET_ADMIN)) 661 goto done; 662 663 if (dev == ipn->fb_tunnel_dev) { 664 err = -EFAULT; 665 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 666 goto done; 667 err = -ENOENT; 668 if ((t = ipip_tunnel_locate(net, &p, 0)) == NULL) 669 goto done; 670 err = -EPERM; 671 if (t->dev == ipn->fb_tunnel_dev) 672 goto done; 673 dev = t->dev; 674 } 675 unregister_netdevice(dev); 676 err = 0; 677 break; 678 679 default: 680 err = -EINVAL; 681 } 682 683 done: 684 return err; 685 } 686 687 static int ipip_tunnel_change_mtu(struct net_device *dev, int new_mtu) 688 { 689 if (new_mtu < 68 || new_mtu > 0xFFF8 - sizeof(struct iphdr)) 690 return -EINVAL; 691 dev->mtu = new_mtu; 692 return 0; 693 } 694 695 static const struct net_device_ops ipip_netdev_ops = { 696 .ndo_uninit = ipip_tunnel_uninit, 697 .ndo_start_xmit = ipip_tunnel_xmit, 698 .ndo_do_ioctl = ipip_tunnel_ioctl, 699 .ndo_change_mtu = ipip_tunnel_change_mtu, 700 701 }; 702 703 static void ipip_tunnel_setup(struct net_device *dev) 704 { 705 dev->netdev_ops = &ipip_netdev_ops; 706 dev->destructor = free_netdev; 707 708 dev->type = ARPHRD_TUNNEL; 709 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); 710 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr); 711 dev->flags = IFF_NOARP; 712 dev->iflink = 0; 713 dev->addr_len = 4; 714 dev->features |= NETIF_F_NETNS_LOCAL; 715 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; 716 } 717 718 static void ipip_tunnel_init(struct net_device *dev) 719 { 720 struct ip_tunnel *tunnel = netdev_priv(dev); 721 722 tunnel->dev = dev; 723 strcpy(tunnel->parms.name, dev->name); 724 725 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); 726 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); 727 728 ipip_tunnel_bind_dev(dev); 729 } 730 731 static void ipip_fb_tunnel_init(struct net_device *dev) 732 { 733 struct ip_tunnel *tunnel = netdev_priv(dev); 734 struct iphdr *iph = &tunnel->parms.iph; 735 struct ipip_net *ipn = net_generic(dev_net(dev), ipip_net_id); 736 737 tunnel->dev = dev; 738 strcpy(tunnel->parms.name, dev->name); 739 740 iph->version = 4; 741 iph->protocol = IPPROTO_IPIP; 742 iph->ihl = 5; 743 744 dev_hold(dev); 745 ipn->tunnels_wc[0] = tunnel; 746 } 747 748 static struct xfrm_tunnel ipip_handler = { 749 .handler = ipip_rcv, 750 .err_handler = ipip_err, 751 .priority = 1, 752 }; 753 754 static const char banner[] __initconst = 755 KERN_INFO "IPv4 over IPv4 tunneling driver\n"; 756 757 static void ipip_destroy_tunnels(struct ipip_net *ipn) 758 { 759 int prio; 760 761 for (prio = 1; prio < 4; prio++) { 762 int h; 763 for (h = 0; h < HASH_SIZE; h++) { 764 struct ip_tunnel *t; 765 while ((t = ipn->tunnels[prio][h]) != NULL) 766 unregister_netdevice(t->dev); 767 } 768 } 769 } 770 771 static int ipip_init_net(struct net *net) 772 { 773 int err; 774 struct ipip_net *ipn; 775 776 err = -ENOMEM; 777 ipn = kzalloc(sizeof(struct ipip_net), GFP_KERNEL); 778 if (ipn == NULL) 779 goto err_alloc; 780 781 err = net_assign_generic(net, ipip_net_id, ipn); 782 if (err < 0) 783 goto err_assign; 784 785 ipn->tunnels[0] = ipn->tunnels_wc; 786 ipn->tunnels[1] = ipn->tunnels_l; 787 ipn->tunnels[2] = ipn->tunnels_r; 788 ipn->tunnels[3] = ipn->tunnels_r_l; 789 790 ipn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), 791 "tunl0", 792 ipip_tunnel_setup); 793 if (!ipn->fb_tunnel_dev) { 794 err = -ENOMEM; 795 goto err_alloc_dev; 796 } 797 dev_net_set(ipn->fb_tunnel_dev, net); 798 799 ipip_fb_tunnel_init(ipn->fb_tunnel_dev); 800 801 if ((err = register_netdev(ipn->fb_tunnel_dev))) 802 goto err_reg_dev; 803 804 return 0; 805 806 err_reg_dev: 807 free_netdev(ipn->fb_tunnel_dev); 808 err_alloc_dev: 809 /* nothing */ 810 err_assign: 811 kfree(ipn); 812 err_alloc: 813 return err; 814 } 815 816 static void ipip_exit_net(struct net *net) 817 { 818 struct ipip_net *ipn; 819 820 ipn = net_generic(net, ipip_net_id); 821 rtnl_lock(); 822 ipip_destroy_tunnels(ipn); 823 unregister_netdevice(ipn->fb_tunnel_dev); 824 rtnl_unlock(); 825 kfree(ipn); 826 } 827 828 static struct pernet_operations ipip_net_ops = { 829 .init = ipip_init_net, 830 .exit = ipip_exit_net, 831 }; 832 833 static int __init ipip_init(void) 834 { 835 int err; 836 837 printk(banner); 838 839 if (xfrm4_tunnel_register(&ipip_handler, AF_INET)) { 840 printk(KERN_INFO "ipip init: can't register tunnel\n"); 841 return -EAGAIN; 842 } 843 844 err = register_pernet_gen_device(&ipip_net_id, &ipip_net_ops); 845 if (err) 846 xfrm4_tunnel_deregister(&ipip_handler, AF_INET); 847 848 return err; 849 } 850 851 static void __exit ipip_fini(void) 852 { 853 if (xfrm4_tunnel_deregister(&ipip_handler, AF_INET)) 854 printk(KERN_INFO "ipip close: can't deregister tunnel\n"); 855 856 unregister_pernet_gen_device(ipip_net_id, &ipip_net_ops); 857 } 858 859 module_init(ipip_init); 860 module_exit(ipip_fini); 861 MODULE_LICENSE("GPL"); 862