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 = &dev->stats; 394 struct netdev_queue *txq = netdev_get_tx_queue(dev, 0); 395 struct iphdr *tiph = &tunnel->parms.iph; 396 u8 tos = tunnel->parms.iph.tos; 397 __be16 df = tiph->frag_off; 398 struct rtable *rt; /* Route to the other host */ 399 struct net_device *tdev; /* Device to other host */ 400 struct iphdr *old_iph = ip_hdr(skb); 401 struct iphdr *iph; /* Our new IP header */ 402 unsigned int max_headroom; /* The extra header space needed */ 403 __be32 dst = tiph->daddr; 404 int mtu; 405 406 if (skb->protocol != htons(ETH_P_IP)) 407 goto tx_error; 408 409 if (tos&1) 410 tos = old_iph->tos; 411 412 if (!dst) { 413 /* NBMA tunnel */ 414 if ((rt = skb_rtable(skb)) == NULL) { 415 stats->tx_fifo_errors++; 416 goto tx_error; 417 } 418 if ((dst = rt->rt_gateway) == 0) 419 goto tx_error_icmp; 420 } 421 422 { 423 struct flowi fl = { .oif = tunnel->parms.link, 424 .nl_u = { .ip4_u = 425 { .daddr = dst, 426 .saddr = tiph->saddr, 427 .tos = RT_TOS(tos) } }, 428 .proto = IPPROTO_IPIP }; 429 if (ip_route_output_key(dev_net(dev), &rt, &fl)) { 430 stats->tx_carrier_errors++; 431 goto tx_error_icmp; 432 } 433 } 434 tdev = rt->u.dst.dev; 435 436 if (tdev == dev) { 437 ip_rt_put(rt); 438 stats->collisions++; 439 goto tx_error; 440 } 441 442 if (tiph->frag_off) 443 mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr); 444 else 445 mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu; 446 447 if (mtu < 68) { 448 stats->collisions++; 449 ip_rt_put(rt); 450 goto tx_error; 451 } 452 if (skb_dst(skb)) 453 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu); 454 455 df |= (old_iph->frag_off&htons(IP_DF)); 456 457 if ((old_iph->frag_off&htons(IP_DF)) && mtu < ntohs(old_iph->tot_len)) { 458 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu)); 459 ip_rt_put(rt); 460 goto tx_error; 461 } 462 463 if (tunnel->err_count > 0) { 464 if (time_before(jiffies, 465 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { 466 tunnel->err_count--; 467 dst_link_failure(skb); 468 } else 469 tunnel->err_count = 0; 470 } 471 472 /* 473 * Okay, now see if we can stuff it in the buffer as-is. 474 */ 475 max_headroom = (LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr)); 476 477 if (skb_headroom(skb) < max_headroom || skb_shared(skb) || 478 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 479 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); 480 if (!new_skb) { 481 ip_rt_put(rt); 482 txq->tx_dropped++; 483 dev_kfree_skb(skb); 484 return NETDEV_TX_OK; 485 } 486 if (skb->sk) 487 skb_set_owner_w(new_skb, skb->sk); 488 dev_kfree_skb(skb); 489 skb = new_skb; 490 old_iph = ip_hdr(skb); 491 } 492 493 skb->transport_header = skb->network_header; 494 skb_push(skb, sizeof(struct iphdr)); 495 skb_reset_network_header(skb); 496 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); 497 IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | 498 IPSKB_REROUTED); 499 skb_dst_drop(skb); 500 skb_dst_set(skb, &rt->u.dst); 501 502 /* 503 * Push down and install the IPIP header. 504 */ 505 506 iph = ip_hdr(skb); 507 iph->version = 4; 508 iph->ihl = sizeof(struct iphdr)>>2; 509 iph->frag_off = df; 510 iph->protocol = IPPROTO_IPIP; 511 iph->tos = INET_ECN_encapsulate(tos, old_iph->tos); 512 iph->daddr = rt->rt_dst; 513 iph->saddr = rt->rt_src; 514 515 if ((iph->ttl = tiph->ttl) == 0) 516 iph->ttl = old_iph->ttl; 517 518 nf_reset(skb); 519 520 IPTUNNEL_XMIT(); 521 return NETDEV_TX_OK; 522 523 tx_error_icmp: 524 dst_link_failure(skb); 525 tx_error: 526 stats->tx_errors++; 527 dev_kfree_skb(skb); 528 return NETDEV_TX_OK; 529 } 530 531 static void ipip_tunnel_bind_dev(struct net_device *dev) 532 { 533 struct net_device *tdev = NULL; 534 struct ip_tunnel *tunnel; 535 struct iphdr *iph; 536 537 tunnel = netdev_priv(dev); 538 iph = &tunnel->parms.iph; 539 540 if (iph->daddr) { 541 struct flowi fl = { .oif = tunnel->parms.link, 542 .nl_u = { .ip4_u = 543 { .daddr = iph->daddr, 544 .saddr = iph->saddr, 545 .tos = RT_TOS(iph->tos) } }, 546 .proto = IPPROTO_IPIP }; 547 struct rtable *rt; 548 if (!ip_route_output_key(dev_net(dev), &rt, &fl)) { 549 tdev = rt->u.dst.dev; 550 ip_rt_put(rt); 551 } 552 dev->flags |= IFF_POINTOPOINT; 553 } 554 555 if (!tdev && tunnel->parms.link) 556 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link); 557 558 if (tdev) { 559 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); 560 dev->mtu = tdev->mtu - sizeof(struct iphdr); 561 } 562 dev->iflink = tunnel->parms.link; 563 } 564 565 static int 566 ipip_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) 567 { 568 int err = 0; 569 struct ip_tunnel_parm p; 570 struct ip_tunnel *t; 571 struct net *net = dev_net(dev); 572 struct ipip_net *ipn = net_generic(net, ipip_net_id); 573 574 switch (cmd) { 575 case SIOCGETTUNNEL: 576 t = NULL; 577 if (dev == ipn->fb_tunnel_dev) { 578 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 579 err = -EFAULT; 580 break; 581 } 582 t = ipip_tunnel_locate(net, &p, 0); 583 } 584 if (t == NULL) 585 t = netdev_priv(dev); 586 memcpy(&p, &t->parms, sizeof(p)); 587 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 588 err = -EFAULT; 589 break; 590 591 case SIOCADDTUNNEL: 592 case SIOCCHGTUNNEL: 593 err = -EPERM; 594 if (!capable(CAP_NET_ADMIN)) 595 goto done; 596 597 err = -EFAULT; 598 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 599 goto done; 600 601 err = -EINVAL; 602 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP || 603 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) 604 goto done; 605 if (p.iph.ttl) 606 p.iph.frag_off |= htons(IP_DF); 607 608 t = ipip_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL); 609 610 if (dev != ipn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 611 if (t != NULL) { 612 if (t->dev != dev) { 613 err = -EEXIST; 614 break; 615 } 616 } else { 617 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || 618 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { 619 err = -EINVAL; 620 break; 621 } 622 t = netdev_priv(dev); 623 ipip_tunnel_unlink(ipn, t); 624 t->parms.iph.saddr = p.iph.saddr; 625 t->parms.iph.daddr = p.iph.daddr; 626 memcpy(dev->dev_addr, &p.iph.saddr, 4); 627 memcpy(dev->broadcast, &p.iph.daddr, 4); 628 ipip_tunnel_link(ipn, t); 629 netdev_state_change(dev); 630 } 631 } 632 633 if (t) { 634 err = 0; 635 if (cmd == SIOCCHGTUNNEL) { 636 t->parms.iph.ttl = p.iph.ttl; 637 t->parms.iph.tos = p.iph.tos; 638 t->parms.iph.frag_off = p.iph.frag_off; 639 if (t->parms.link != p.link) { 640 t->parms.link = p.link; 641 ipip_tunnel_bind_dev(dev); 642 netdev_state_change(dev); 643 } 644 } 645 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) 646 err = -EFAULT; 647 } else 648 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 649 break; 650 651 case SIOCDELTUNNEL: 652 err = -EPERM; 653 if (!capable(CAP_NET_ADMIN)) 654 goto done; 655 656 if (dev == ipn->fb_tunnel_dev) { 657 err = -EFAULT; 658 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 659 goto done; 660 err = -ENOENT; 661 if ((t = ipip_tunnel_locate(net, &p, 0)) == NULL) 662 goto done; 663 err = -EPERM; 664 if (t->dev == ipn->fb_tunnel_dev) 665 goto done; 666 dev = t->dev; 667 } 668 unregister_netdevice(dev); 669 err = 0; 670 break; 671 672 default: 673 err = -EINVAL; 674 } 675 676 done: 677 return err; 678 } 679 680 static int ipip_tunnel_change_mtu(struct net_device *dev, int new_mtu) 681 { 682 if (new_mtu < 68 || new_mtu > 0xFFF8 - sizeof(struct iphdr)) 683 return -EINVAL; 684 dev->mtu = new_mtu; 685 return 0; 686 } 687 688 static const struct net_device_ops ipip_netdev_ops = { 689 .ndo_uninit = ipip_tunnel_uninit, 690 .ndo_start_xmit = ipip_tunnel_xmit, 691 .ndo_do_ioctl = ipip_tunnel_ioctl, 692 .ndo_change_mtu = ipip_tunnel_change_mtu, 693 694 }; 695 696 static void ipip_tunnel_setup(struct net_device *dev) 697 { 698 dev->netdev_ops = &ipip_netdev_ops; 699 dev->destructor = free_netdev; 700 701 dev->type = ARPHRD_TUNNEL; 702 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); 703 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr); 704 dev->flags = IFF_NOARP; 705 dev->iflink = 0; 706 dev->addr_len = 4; 707 dev->features |= NETIF_F_NETNS_LOCAL; 708 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; 709 } 710 711 static void ipip_tunnel_init(struct net_device *dev) 712 { 713 struct ip_tunnel *tunnel = netdev_priv(dev); 714 715 tunnel->dev = dev; 716 strcpy(tunnel->parms.name, dev->name); 717 718 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); 719 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); 720 721 ipip_tunnel_bind_dev(dev); 722 } 723 724 static void ipip_fb_tunnel_init(struct net_device *dev) 725 { 726 struct ip_tunnel *tunnel = netdev_priv(dev); 727 struct iphdr *iph = &tunnel->parms.iph; 728 struct ipip_net *ipn = net_generic(dev_net(dev), ipip_net_id); 729 730 tunnel->dev = dev; 731 strcpy(tunnel->parms.name, dev->name); 732 733 iph->version = 4; 734 iph->protocol = IPPROTO_IPIP; 735 iph->ihl = 5; 736 737 dev_hold(dev); 738 ipn->tunnels_wc[0] = tunnel; 739 } 740 741 static struct xfrm_tunnel ipip_handler = { 742 .handler = ipip_rcv, 743 .err_handler = ipip_err, 744 .priority = 1, 745 }; 746 747 static const char banner[] __initconst = 748 KERN_INFO "IPv4 over IPv4 tunneling driver\n"; 749 750 static void ipip_destroy_tunnels(struct ipip_net *ipn) 751 { 752 int prio; 753 754 for (prio = 1; prio < 4; prio++) { 755 int h; 756 for (h = 0; h < HASH_SIZE; h++) { 757 struct ip_tunnel *t; 758 while ((t = ipn->tunnels[prio][h]) != NULL) 759 unregister_netdevice(t->dev); 760 } 761 } 762 } 763 764 static int ipip_init_net(struct net *net) 765 { 766 int err; 767 struct ipip_net *ipn; 768 769 err = -ENOMEM; 770 ipn = kzalloc(sizeof(struct ipip_net), GFP_KERNEL); 771 if (ipn == NULL) 772 goto err_alloc; 773 774 err = net_assign_generic(net, ipip_net_id, ipn); 775 if (err < 0) 776 goto err_assign; 777 778 ipn->tunnels[0] = ipn->tunnels_wc; 779 ipn->tunnels[1] = ipn->tunnels_l; 780 ipn->tunnels[2] = ipn->tunnels_r; 781 ipn->tunnels[3] = ipn->tunnels_r_l; 782 783 ipn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), 784 "tunl0", 785 ipip_tunnel_setup); 786 if (!ipn->fb_tunnel_dev) { 787 err = -ENOMEM; 788 goto err_alloc_dev; 789 } 790 dev_net_set(ipn->fb_tunnel_dev, net); 791 792 ipip_fb_tunnel_init(ipn->fb_tunnel_dev); 793 794 if ((err = register_netdev(ipn->fb_tunnel_dev))) 795 goto err_reg_dev; 796 797 return 0; 798 799 err_reg_dev: 800 free_netdev(ipn->fb_tunnel_dev); 801 err_alloc_dev: 802 /* nothing */ 803 err_assign: 804 kfree(ipn); 805 err_alloc: 806 return err; 807 } 808 809 static void ipip_exit_net(struct net *net) 810 { 811 struct ipip_net *ipn; 812 813 ipn = net_generic(net, ipip_net_id); 814 rtnl_lock(); 815 ipip_destroy_tunnels(ipn); 816 unregister_netdevice(ipn->fb_tunnel_dev); 817 rtnl_unlock(); 818 kfree(ipn); 819 } 820 821 static struct pernet_operations ipip_net_ops = { 822 .init = ipip_init_net, 823 .exit = ipip_exit_net, 824 }; 825 826 static int __init ipip_init(void) 827 { 828 int err; 829 830 printk(banner); 831 832 if (xfrm4_tunnel_register(&ipip_handler, AF_INET)) { 833 printk(KERN_INFO "ipip init: can't register tunnel\n"); 834 return -EAGAIN; 835 } 836 837 err = register_pernet_gen_device(&ipip_net_id, &ipip_net_ops); 838 if (err) 839 xfrm4_tunnel_deregister(&ipip_handler, AF_INET); 840 841 return err; 842 } 843 844 static void __exit ipip_fini(void) 845 { 846 if (xfrm4_tunnel_deregister(&ipip_handler, AF_INET)) 847 printk(KERN_INFO "ipip close: can't deregister tunnel\n"); 848 849 unregister_pernet_gen_device(ipip_net_id, &ipip_net_ops); 850 } 851 852 module_init(ipip_init); 853 module_exit(ipip_fini); 854 MODULE_LICENSE("GPL"); 855