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 unsigned long rx_packets; 148 unsigned long rx_bytes; 149 unsigned long tx_packets; 150 unsigned long tx_bytes; 151 }; 152 153 static struct net_device_stats *ipip_get_stats(struct net_device *dev) 154 { 155 struct pcpu_tstats sum = { 0 }; 156 int i; 157 158 for_each_possible_cpu(i) { 159 const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i); 160 161 sum.rx_packets += tstats->rx_packets; 162 sum.rx_bytes += tstats->rx_bytes; 163 sum.tx_packets += tstats->tx_packets; 164 sum.tx_bytes += tstats->tx_bytes; 165 } 166 dev->stats.rx_packets = sum.rx_packets; 167 dev->stats.rx_bytes = sum.rx_bytes; 168 dev->stats.tx_packets = sum.tx_packets; 169 dev->stats.tx_bytes = sum.tx_bytes; 170 return &dev->stats; 171 } 172 173 static struct ip_tunnel * ipip_tunnel_lookup(struct net *net, 174 __be32 remote, __be32 local) 175 { 176 unsigned int h0 = HASH(remote); 177 unsigned int h1 = HASH(local); 178 struct ip_tunnel *t; 179 struct ipip_net *ipn = net_generic(net, ipip_net_id); 180 181 for_each_ip_tunnel_rcu(ipn->tunnels_r_l[h0 ^ h1]) 182 if (local == t->parms.iph.saddr && 183 remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP)) 184 return t; 185 186 for_each_ip_tunnel_rcu(ipn->tunnels_r[h0]) 187 if (remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP)) 188 return t; 189 190 for_each_ip_tunnel_rcu(ipn->tunnels_l[h1]) 191 if (local == t->parms.iph.saddr && (t->dev->flags&IFF_UP)) 192 return t; 193 194 t = rcu_dereference(ipn->tunnels_wc[0]); 195 if (t && (t->dev->flags&IFF_UP)) 196 return t; 197 return NULL; 198 } 199 200 static struct ip_tunnel __rcu **__ipip_bucket(struct ipip_net *ipn, 201 struct ip_tunnel_parm *parms) 202 { 203 __be32 remote = parms->iph.daddr; 204 __be32 local = parms->iph.saddr; 205 unsigned int h = 0; 206 int prio = 0; 207 208 if (remote) { 209 prio |= 2; 210 h ^= HASH(remote); 211 } 212 if (local) { 213 prio |= 1; 214 h ^= HASH(local); 215 } 216 return &ipn->tunnels[prio][h]; 217 } 218 219 static inline struct ip_tunnel __rcu **ipip_bucket(struct ipip_net *ipn, 220 struct ip_tunnel *t) 221 { 222 return __ipip_bucket(ipn, &t->parms); 223 } 224 225 static void ipip_tunnel_unlink(struct ipip_net *ipn, struct ip_tunnel *t) 226 { 227 struct ip_tunnel __rcu **tp; 228 struct ip_tunnel *iter; 229 230 for (tp = ipip_bucket(ipn, t); 231 (iter = rtnl_dereference(*tp)) != NULL; 232 tp = &iter->next) { 233 if (t == iter) { 234 rcu_assign_pointer(*tp, t->next); 235 break; 236 } 237 } 238 } 239 240 static void ipip_tunnel_link(struct ipip_net *ipn, struct ip_tunnel *t) 241 { 242 struct ip_tunnel __rcu **tp = ipip_bucket(ipn, t); 243 244 rcu_assign_pointer(t->next, rtnl_dereference(*tp)); 245 rcu_assign_pointer(*tp, t); 246 } 247 248 static struct ip_tunnel * ipip_tunnel_locate(struct net *net, 249 struct ip_tunnel_parm *parms, int create) 250 { 251 __be32 remote = parms->iph.daddr; 252 __be32 local = parms->iph.saddr; 253 struct ip_tunnel *t, *nt; 254 struct ip_tunnel __rcu **tp; 255 struct net_device *dev; 256 char name[IFNAMSIZ]; 257 struct ipip_net *ipn = net_generic(net, ipip_net_id); 258 259 for (tp = __ipip_bucket(ipn, parms); 260 (t = rtnl_dereference(*tp)) != NULL; 261 tp = &t->next) { 262 if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr) 263 return t; 264 } 265 if (!create) 266 return NULL; 267 268 if (parms->name[0]) 269 strlcpy(name, parms->name, IFNAMSIZ); 270 else 271 strcpy(name, "tunl%d"); 272 273 dev = alloc_netdev(sizeof(*t), name, ipip_tunnel_setup); 274 if (dev == NULL) 275 return NULL; 276 277 dev_net_set(dev, net); 278 279 if (strchr(name, '%')) { 280 if (dev_alloc_name(dev, name) < 0) 281 goto failed_free; 282 } 283 284 nt = netdev_priv(dev); 285 nt->parms = *parms; 286 287 if (ipip_tunnel_init(dev) < 0) 288 goto failed_free; 289 290 if (register_netdevice(dev) < 0) 291 goto failed_free; 292 293 dev_hold(dev); 294 ipip_tunnel_link(ipn, nt); 295 return nt; 296 297 failed_free: 298 ipip_dev_free(dev); 299 return NULL; 300 } 301 302 /* called with RTNL */ 303 static void ipip_tunnel_uninit(struct net_device *dev) 304 { 305 struct net *net = dev_net(dev); 306 struct ipip_net *ipn = net_generic(net, ipip_net_id); 307 308 if (dev == ipn->fb_tunnel_dev) 309 rcu_assign_pointer(ipn->tunnels_wc[0], NULL); 310 else 311 ipip_tunnel_unlink(ipn, netdev_priv(dev)); 312 dev_put(dev); 313 } 314 315 static int ipip_err(struct sk_buff *skb, u32 info) 316 { 317 318 /* All the routers (except for Linux) return only 319 8 bytes of packet payload. It means, that precise relaying of 320 ICMP in the real Internet is absolutely infeasible. 321 */ 322 struct iphdr *iph = (struct iphdr *)skb->data; 323 const int type = icmp_hdr(skb)->type; 324 const int code = icmp_hdr(skb)->code; 325 struct ip_tunnel *t; 326 int err; 327 328 switch (type) { 329 default: 330 case ICMP_PARAMETERPROB: 331 return 0; 332 333 case ICMP_DEST_UNREACH: 334 switch (code) { 335 case ICMP_SR_FAILED: 336 case ICMP_PORT_UNREACH: 337 /* Impossible event. */ 338 return 0; 339 case ICMP_FRAG_NEEDED: 340 /* Soft state for pmtu is maintained by IP core. */ 341 return 0; 342 default: 343 /* All others are translated to HOST_UNREACH. 344 rfc2003 contains "deep thoughts" about NET_UNREACH, 345 I believe they are just ether pollution. --ANK 346 */ 347 break; 348 } 349 break; 350 case ICMP_TIME_EXCEEDED: 351 if (code != ICMP_EXC_TTL) 352 return 0; 353 break; 354 } 355 356 err = -ENOENT; 357 358 rcu_read_lock(); 359 t = ipip_tunnel_lookup(dev_net(skb->dev), iph->daddr, iph->saddr); 360 if (t == NULL || t->parms.iph.daddr == 0) 361 goto out; 362 363 err = 0; 364 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 365 goto out; 366 367 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) 368 t->err_count++; 369 else 370 t->err_count = 1; 371 t->err_time = jiffies; 372 out: 373 rcu_read_unlock(); 374 return err; 375 } 376 377 static inline void ipip_ecn_decapsulate(const struct iphdr *outer_iph, 378 struct sk_buff *skb) 379 { 380 struct iphdr *inner_iph = ip_hdr(skb); 381 382 if (INET_ECN_is_ce(outer_iph->tos)) 383 IP_ECN_set_ce(inner_iph); 384 } 385 386 static int ipip_rcv(struct sk_buff *skb) 387 { 388 struct ip_tunnel *tunnel; 389 const struct iphdr *iph = ip_hdr(skb); 390 391 rcu_read_lock(); 392 tunnel = ipip_tunnel_lookup(dev_net(skb->dev), iph->saddr, iph->daddr); 393 if (tunnel != NULL) { 394 struct pcpu_tstats *tstats; 395 396 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { 397 rcu_read_unlock(); 398 kfree_skb(skb); 399 return 0; 400 } 401 402 secpath_reset(skb); 403 404 skb->mac_header = skb->network_header; 405 skb_reset_network_header(skb); 406 skb->protocol = htons(ETH_P_IP); 407 skb->pkt_type = PACKET_HOST; 408 409 tstats = this_cpu_ptr(tunnel->dev->tstats); 410 tstats->rx_packets++; 411 tstats->rx_bytes += skb->len; 412 413 __skb_tunnel_rx(skb, tunnel->dev); 414 415 ipip_ecn_decapsulate(iph, skb); 416 417 netif_rx(skb); 418 419 rcu_read_unlock(); 420 return 0; 421 } 422 rcu_read_unlock(); 423 424 return -1; 425 } 426 427 /* 428 * This function assumes it is being called from dev_queue_xmit() 429 * and that skb is filled properly by that function. 430 */ 431 432 static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) 433 { 434 struct ip_tunnel *tunnel = netdev_priv(dev); 435 struct pcpu_tstats *tstats; 436 struct iphdr *tiph = &tunnel->parms.iph; 437 u8 tos = tunnel->parms.iph.tos; 438 __be16 df = tiph->frag_off; 439 struct rtable *rt; /* Route to the other host */ 440 struct net_device *tdev; /* Device to other host */ 441 struct iphdr *old_iph = ip_hdr(skb); 442 struct iphdr *iph; /* Our new IP header */ 443 unsigned int max_headroom; /* The extra header space needed */ 444 __be32 dst = tiph->daddr; 445 int mtu; 446 447 if (skb->protocol != htons(ETH_P_IP)) 448 goto tx_error; 449 450 if (tos & 1) 451 tos = old_iph->tos; 452 453 if (!dst) { 454 /* NBMA tunnel */ 455 if ((rt = skb_rtable(skb)) == NULL) { 456 dev->stats.tx_fifo_errors++; 457 goto tx_error; 458 } 459 if ((dst = rt->rt_gateway) == 0) 460 goto tx_error_icmp; 461 } 462 463 { 464 struct flowi fl = { 465 .oif = tunnel->parms.link, 466 .fl4_dst = dst, 467 .fl4_src= tiph->saddr, 468 .fl4_tos = RT_TOS(tos), 469 .proto = IPPROTO_IPIP 470 }; 471 472 if (ip_route_output_key(dev_net(dev), &rt, &fl)) { 473 dev->stats.tx_carrier_errors++; 474 goto tx_error_icmp; 475 } 476 } 477 tdev = rt->dst.dev; 478 479 if (tdev == dev) { 480 ip_rt_put(rt); 481 dev->stats.collisions++; 482 goto tx_error; 483 } 484 485 df |= old_iph->frag_off & htons(IP_DF); 486 487 if (df) { 488 mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr); 489 490 if (mtu < 68) { 491 dev->stats.collisions++; 492 ip_rt_put(rt); 493 goto tx_error; 494 } 495 496 if (skb_dst(skb)) 497 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu); 498 499 if ((old_iph->frag_off & htons(IP_DF)) && 500 mtu < ntohs(old_iph->tot_len)) { 501 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, 502 htonl(mtu)); 503 ip_rt_put(rt); 504 goto tx_error; 505 } 506 } 507 508 if (tunnel->err_count > 0) { 509 if (time_before(jiffies, 510 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { 511 tunnel->err_count--; 512 dst_link_failure(skb); 513 } else 514 tunnel->err_count = 0; 515 } 516 517 /* 518 * Okay, now see if we can stuff it in the buffer as-is. 519 */ 520 max_headroom = (LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr)); 521 522 if (skb_headroom(skb) < max_headroom || skb_shared(skb) || 523 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 524 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); 525 if (!new_skb) { 526 ip_rt_put(rt); 527 dev->stats.tx_dropped++; 528 dev_kfree_skb(skb); 529 return NETDEV_TX_OK; 530 } 531 if (skb->sk) 532 skb_set_owner_w(new_skb, skb->sk); 533 dev_kfree_skb(skb); 534 skb = new_skb; 535 old_iph = ip_hdr(skb); 536 } 537 538 skb->transport_header = skb->network_header; 539 skb_push(skb, sizeof(struct iphdr)); 540 skb_reset_network_header(skb); 541 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); 542 IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | 543 IPSKB_REROUTED); 544 skb_dst_drop(skb); 545 skb_dst_set(skb, &rt->dst); 546 547 /* 548 * Push down and install the IPIP header. 549 */ 550 551 iph = ip_hdr(skb); 552 iph->version = 4; 553 iph->ihl = sizeof(struct iphdr)>>2; 554 iph->frag_off = df; 555 iph->protocol = IPPROTO_IPIP; 556 iph->tos = INET_ECN_encapsulate(tos, old_iph->tos); 557 iph->daddr = rt->rt_dst; 558 iph->saddr = rt->rt_src; 559 560 if ((iph->ttl = tiph->ttl) == 0) 561 iph->ttl = old_iph->ttl; 562 563 nf_reset(skb); 564 tstats = this_cpu_ptr(dev->tstats); 565 __IPTUNNEL_XMIT(tstats, &dev->stats); 566 return NETDEV_TX_OK; 567 568 tx_error_icmp: 569 dst_link_failure(skb); 570 tx_error: 571 dev->stats.tx_errors++; 572 dev_kfree_skb(skb); 573 return NETDEV_TX_OK; 574 } 575 576 static void ipip_tunnel_bind_dev(struct net_device *dev) 577 { 578 struct net_device *tdev = NULL; 579 struct ip_tunnel *tunnel; 580 struct iphdr *iph; 581 582 tunnel = netdev_priv(dev); 583 iph = &tunnel->parms.iph; 584 585 if (iph->daddr) { 586 struct flowi fl = { 587 .oif = tunnel->parms.link, 588 .fl4_dst = iph->daddr, 589 .fl4_src = iph->saddr, 590 .fl4_tos = RT_TOS(iph->tos), 591 .proto = IPPROTO_IPIP 592 }; 593 struct rtable *rt; 594 595 if (!ip_route_output_key(dev_net(dev), &rt, &fl)) { 596 tdev = rt->dst.dev; 597 ip_rt_put(rt); 598 } 599 dev->flags |= IFF_POINTOPOINT; 600 } 601 602 if (!tdev && tunnel->parms.link) 603 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link); 604 605 if (tdev) { 606 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); 607 dev->mtu = tdev->mtu - sizeof(struct iphdr); 608 } 609 dev->iflink = tunnel->parms.link; 610 } 611 612 static int 613 ipip_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) 614 { 615 int err = 0; 616 struct ip_tunnel_parm p; 617 struct ip_tunnel *t; 618 struct net *net = dev_net(dev); 619 struct ipip_net *ipn = net_generic(net, ipip_net_id); 620 621 switch (cmd) { 622 case SIOCGETTUNNEL: 623 t = NULL; 624 if (dev == ipn->fb_tunnel_dev) { 625 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 626 err = -EFAULT; 627 break; 628 } 629 t = ipip_tunnel_locate(net, &p, 0); 630 } 631 if (t == NULL) 632 t = netdev_priv(dev); 633 memcpy(&p, &t->parms, sizeof(p)); 634 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 635 err = -EFAULT; 636 break; 637 638 case SIOCADDTUNNEL: 639 case SIOCCHGTUNNEL: 640 err = -EPERM; 641 if (!capable(CAP_NET_ADMIN)) 642 goto done; 643 644 err = -EFAULT; 645 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 646 goto done; 647 648 err = -EINVAL; 649 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP || 650 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) 651 goto done; 652 if (p.iph.ttl) 653 p.iph.frag_off |= htons(IP_DF); 654 655 t = ipip_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL); 656 657 if (dev != ipn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 658 if (t != NULL) { 659 if (t->dev != dev) { 660 err = -EEXIST; 661 break; 662 } 663 } else { 664 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || 665 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { 666 err = -EINVAL; 667 break; 668 } 669 t = netdev_priv(dev); 670 ipip_tunnel_unlink(ipn, t); 671 synchronize_net(); 672 t->parms.iph.saddr = p.iph.saddr; 673 t->parms.iph.daddr = p.iph.daddr; 674 memcpy(dev->dev_addr, &p.iph.saddr, 4); 675 memcpy(dev->broadcast, &p.iph.daddr, 4); 676 ipip_tunnel_link(ipn, t); 677 netdev_state_change(dev); 678 } 679 } 680 681 if (t) { 682 err = 0; 683 if (cmd == SIOCCHGTUNNEL) { 684 t->parms.iph.ttl = p.iph.ttl; 685 t->parms.iph.tos = p.iph.tos; 686 t->parms.iph.frag_off = p.iph.frag_off; 687 if (t->parms.link != p.link) { 688 t->parms.link = p.link; 689 ipip_tunnel_bind_dev(dev); 690 netdev_state_change(dev); 691 } 692 } 693 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) 694 err = -EFAULT; 695 } else 696 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 697 break; 698 699 case SIOCDELTUNNEL: 700 err = -EPERM; 701 if (!capable(CAP_NET_ADMIN)) 702 goto done; 703 704 if (dev == ipn->fb_tunnel_dev) { 705 err = -EFAULT; 706 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 707 goto done; 708 err = -ENOENT; 709 if ((t = ipip_tunnel_locate(net, &p, 0)) == NULL) 710 goto done; 711 err = -EPERM; 712 if (t->dev == ipn->fb_tunnel_dev) 713 goto done; 714 dev = t->dev; 715 } 716 unregister_netdevice(dev); 717 err = 0; 718 break; 719 720 default: 721 err = -EINVAL; 722 } 723 724 done: 725 return err; 726 } 727 728 static int ipip_tunnel_change_mtu(struct net_device *dev, int new_mtu) 729 { 730 if (new_mtu < 68 || new_mtu > 0xFFF8 - sizeof(struct iphdr)) 731 return -EINVAL; 732 dev->mtu = new_mtu; 733 return 0; 734 } 735 736 static const struct net_device_ops ipip_netdev_ops = { 737 .ndo_uninit = ipip_tunnel_uninit, 738 .ndo_start_xmit = ipip_tunnel_xmit, 739 .ndo_do_ioctl = ipip_tunnel_ioctl, 740 .ndo_change_mtu = ipip_tunnel_change_mtu, 741 .ndo_get_stats = ipip_get_stats, 742 }; 743 744 static void ipip_dev_free(struct net_device *dev) 745 { 746 free_percpu(dev->tstats); 747 free_netdev(dev); 748 } 749 750 static void ipip_tunnel_setup(struct net_device *dev) 751 { 752 dev->netdev_ops = &ipip_netdev_ops; 753 dev->destructor = ipip_dev_free; 754 755 dev->type = ARPHRD_TUNNEL; 756 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); 757 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr); 758 dev->flags = IFF_NOARP; 759 dev->iflink = 0; 760 dev->addr_len = 4; 761 dev->features |= NETIF_F_NETNS_LOCAL; 762 dev->features |= NETIF_F_LLTX; 763 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; 764 } 765 766 static int ipip_tunnel_init(struct net_device *dev) 767 { 768 struct ip_tunnel *tunnel = netdev_priv(dev); 769 770 tunnel->dev = dev; 771 strcpy(tunnel->parms.name, dev->name); 772 773 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); 774 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); 775 776 ipip_tunnel_bind_dev(dev); 777 778 dev->tstats = alloc_percpu(struct pcpu_tstats); 779 if (!dev->tstats) 780 return -ENOMEM; 781 782 return 0; 783 } 784 785 static int __net_init ipip_fb_tunnel_init(struct net_device *dev) 786 { 787 struct ip_tunnel *tunnel = netdev_priv(dev); 788 struct iphdr *iph = &tunnel->parms.iph; 789 struct ipip_net *ipn = net_generic(dev_net(dev), ipip_net_id); 790 791 tunnel->dev = dev; 792 strcpy(tunnel->parms.name, dev->name); 793 794 iph->version = 4; 795 iph->protocol = IPPROTO_IPIP; 796 iph->ihl = 5; 797 798 dev->tstats = alloc_percpu(struct pcpu_tstats); 799 if (!dev->tstats) 800 return -ENOMEM; 801 802 dev_hold(dev); 803 rcu_assign_pointer(ipn->tunnels_wc[0], tunnel); 804 return 0; 805 } 806 807 static struct xfrm_tunnel ipip_handler __read_mostly = { 808 .handler = ipip_rcv, 809 .err_handler = ipip_err, 810 .priority = 1, 811 }; 812 813 static const char banner[] __initconst = 814 KERN_INFO "IPv4 over IPv4 tunneling driver\n"; 815 816 static void ipip_destroy_tunnels(struct ipip_net *ipn, struct list_head *head) 817 { 818 int prio; 819 820 for (prio = 1; prio < 4; prio++) { 821 int h; 822 for (h = 0; h < HASH_SIZE; h++) { 823 struct ip_tunnel *t; 824 825 t = rtnl_dereference(ipn->tunnels[prio][h]); 826 while (t != NULL) { 827 unregister_netdevice_queue(t->dev, head); 828 t = rtnl_dereference(t->next); 829 } 830 } 831 } 832 } 833 834 static int __net_init ipip_init_net(struct net *net) 835 { 836 struct ipip_net *ipn = net_generic(net, ipip_net_id); 837 int err; 838 839 ipn->tunnels[0] = ipn->tunnels_wc; 840 ipn->tunnels[1] = ipn->tunnels_l; 841 ipn->tunnels[2] = ipn->tunnels_r; 842 ipn->tunnels[3] = ipn->tunnels_r_l; 843 844 ipn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), 845 "tunl0", 846 ipip_tunnel_setup); 847 if (!ipn->fb_tunnel_dev) { 848 err = -ENOMEM; 849 goto err_alloc_dev; 850 } 851 dev_net_set(ipn->fb_tunnel_dev, net); 852 853 err = ipip_fb_tunnel_init(ipn->fb_tunnel_dev); 854 if (err) 855 goto err_reg_dev; 856 857 if ((err = register_netdev(ipn->fb_tunnel_dev))) 858 goto err_reg_dev; 859 860 return 0; 861 862 err_reg_dev: 863 ipip_dev_free(ipn->fb_tunnel_dev); 864 err_alloc_dev: 865 /* nothing */ 866 return err; 867 } 868 869 static void __net_exit ipip_exit_net(struct net *net) 870 { 871 struct ipip_net *ipn = net_generic(net, ipip_net_id); 872 LIST_HEAD(list); 873 874 rtnl_lock(); 875 ipip_destroy_tunnels(ipn, &list); 876 unregister_netdevice_queue(ipn->fb_tunnel_dev, &list); 877 unregister_netdevice_many(&list); 878 rtnl_unlock(); 879 } 880 881 static struct pernet_operations ipip_net_ops = { 882 .init = ipip_init_net, 883 .exit = ipip_exit_net, 884 .id = &ipip_net_id, 885 .size = sizeof(struct ipip_net), 886 }; 887 888 static int __init ipip_init(void) 889 { 890 int err; 891 892 printk(banner); 893 894 err = register_pernet_device(&ipip_net_ops); 895 if (err < 0) 896 return err; 897 err = xfrm4_tunnel_register(&ipip_handler, AF_INET); 898 if (err < 0) { 899 unregister_pernet_device(&ipip_net_ops); 900 printk(KERN_INFO "ipip init: can't register tunnel\n"); 901 } 902 return err; 903 } 904 905 static void __exit ipip_fini(void) 906 { 907 if (xfrm4_tunnel_deregister(&ipip_handler, AF_INET)) 908 printk(KERN_INFO "ipip close: can't deregister tunnel\n"); 909 910 unregister_pernet_device(&ipip_net_ops); 911 } 912 913 module_init(ipip_init); 914 module_exit(ipip_fini); 915 MODULE_LICENSE("GPL"); 916 MODULE_ALIAS("tunl0"); 917