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 } __attribute__((aligned(4*sizeof(unsigned long)))); 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 nt = netdev_priv(dev); 280 nt->parms = *parms; 281 282 if (ipip_tunnel_init(dev) < 0) 283 goto failed_free; 284 285 if (register_netdevice(dev) < 0) 286 goto failed_free; 287 288 strcpy(nt->parms.name, dev->name); 289 290 dev_hold(dev); 291 ipip_tunnel_link(ipn, nt); 292 return nt; 293 294 failed_free: 295 ipip_dev_free(dev); 296 return NULL; 297 } 298 299 /* called with RTNL */ 300 static void ipip_tunnel_uninit(struct net_device *dev) 301 { 302 struct net *net = dev_net(dev); 303 struct ipip_net *ipn = net_generic(net, ipip_net_id); 304 305 if (dev == ipn->fb_tunnel_dev) 306 RCU_INIT_POINTER(ipn->tunnels_wc[0], NULL); 307 else 308 ipip_tunnel_unlink(ipn, netdev_priv(dev)); 309 dev_put(dev); 310 } 311 312 static int ipip_err(struct sk_buff *skb, u32 info) 313 { 314 315 /* All the routers (except for Linux) return only 316 8 bytes of packet payload. It means, that precise relaying of 317 ICMP in the real Internet is absolutely infeasible. 318 */ 319 const struct iphdr *iph = (const struct iphdr *)skb->data; 320 const int type = icmp_hdr(skb)->type; 321 const int code = icmp_hdr(skb)->code; 322 struct ip_tunnel *t; 323 int err; 324 325 switch (type) { 326 default: 327 case ICMP_PARAMETERPROB: 328 return 0; 329 330 case ICMP_DEST_UNREACH: 331 switch (code) { 332 case ICMP_SR_FAILED: 333 case ICMP_PORT_UNREACH: 334 /* Impossible event. */ 335 return 0; 336 case ICMP_FRAG_NEEDED: 337 /* Soft state for pmtu is maintained by IP core. */ 338 return 0; 339 default: 340 /* All others are translated to HOST_UNREACH. 341 rfc2003 contains "deep thoughts" about NET_UNREACH, 342 I believe they are just ether pollution. --ANK 343 */ 344 break; 345 } 346 break; 347 case ICMP_TIME_EXCEEDED: 348 if (code != ICMP_EXC_TTL) 349 return 0; 350 break; 351 } 352 353 err = -ENOENT; 354 355 rcu_read_lock(); 356 t = ipip_tunnel_lookup(dev_net(skb->dev), iph->daddr, iph->saddr); 357 if (t == NULL || t->parms.iph.daddr == 0) 358 goto out; 359 360 err = 0; 361 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 362 goto out; 363 364 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) 365 t->err_count++; 366 else 367 t->err_count = 1; 368 t->err_time = jiffies; 369 out: 370 rcu_read_unlock(); 371 return err; 372 } 373 374 static inline void ipip_ecn_decapsulate(const struct iphdr *outer_iph, 375 struct sk_buff *skb) 376 { 377 struct iphdr *inner_iph = ip_hdr(skb); 378 379 if (INET_ECN_is_ce(outer_iph->tos)) 380 IP_ECN_set_ce(inner_iph); 381 } 382 383 static int ipip_rcv(struct sk_buff *skb) 384 { 385 struct ip_tunnel *tunnel; 386 const struct iphdr *iph = ip_hdr(skb); 387 388 rcu_read_lock(); 389 tunnel = ipip_tunnel_lookup(dev_net(skb->dev), iph->saddr, iph->daddr); 390 if (tunnel != NULL) { 391 struct pcpu_tstats *tstats; 392 393 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { 394 rcu_read_unlock(); 395 kfree_skb(skb); 396 return 0; 397 } 398 399 secpath_reset(skb); 400 401 skb->mac_header = skb->network_header; 402 skb_reset_network_header(skb); 403 skb->protocol = htons(ETH_P_IP); 404 skb->pkt_type = PACKET_HOST; 405 406 tstats = this_cpu_ptr(tunnel->dev->tstats); 407 tstats->rx_packets++; 408 tstats->rx_bytes += skb->len; 409 410 __skb_tunnel_rx(skb, tunnel->dev); 411 412 ipip_ecn_decapsulate(iph, skb); 413 414 netif_rx(skb); 415 416 rcu_read_unlock(); 417 return 0; 418 } 419 rcu_read_unlock(); 420 421 return -1; 422 } 423 424 /* 425 * This function assumes it is being called from dev_queue_xmit() 426 * and that skb is filled properly by that function. 427 */ 428 429 static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) 430 { 431 struct ip_tunnel *tunnel = netdev_priv(dev); 432 struct pcpu_tstats *tstats; 433 const struct iphdr *tiph = &tunnel->parms.iph; 434 u8 tos = tunnel->parms.iph.tos; 435 __be16 df = tiph->frag_off; 436 struct rtable *rt; /* Route to the other host */ 437 struct net_device *tdev; /* Device to other host */ 438 const struct iphdr *old_iph = ip_hdr(skb); 439 struct iphdr *iph; /* Our new IP header */ 440 unsigned int max_headroom; /* The extra header space needed */ 441 __be32 dst = tiph->daddr; 442 struct flowi4 fl4; 443 int mtu; 444 445 if (skb->protocol != htons(ETH_P_IP)) 446 goto tx_error; 447 448 if (tos & 1) 449 tos = old_iph->tos; 450 451 if (!dst) { 452 /* NBMA tunnel */ 453 if ((rt = skb_rtable(skb)) == NULL) { 454 dev->stats.tx_fifo_errors++; 455 goto tx_error; 456 } 457 if ((dst = rt->rt_gateway) == 0) 458 goto tx_error_icmp; 459 } 460 461 rt = ip_route_output_ports(dev_net(dev), &fl4, NULL, 462 dst, tiph->saddr, 463 0, 0, 464 IPPROTO_IPIP, RT_TOS(tos), 465 tunnel->parms.link); 466 if (IS_ERR(rt)) { 467 dev->stats.tx_carrier_errors++; 468 goto tx_error_icmp; 469 } 470 tdev = rt->dst.dev; 471 472 if (tdev == dev) { 473 ip_rt_put(rt); 474 dev->stats.collisions++; 475 goto tx_error; 476 } 477 478 df |= old_iph->frag_off & htons(IP_DF); 479 480 if (df) { 481 mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr); 482 483 if (mtu < 68) { 484 dev->stats.collisions++; 485 ip_rt_put(rt); 486 goto tx_error; 487 } 488 489 if (skb_dst(skb)) 490 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu); 491 492 if ((old_iph->frag_off & htons(IP_DF)) && 493 mtu < ntohs(old_iph->tot_len)) { 494 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, 495 htonl(mtu)); 496 ip_rt_put(rt); 497 goto tx_error; 498 } 499 } 500 501 if (tunnel->err_count > 0) { 502 if (time_before(jiffies, 503 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { 504 tunnel->err_count--; 505 dst_link_failure(skb); 506 } else 507 tunnel->err_count = 0; 508 } 509 510 /* 511 * Okay, now see if we can stuff it in the buffer as-is. 512 */ 513 max_headroom = (LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr)); 514 515 if (skb_headroom(skb) < max_headroom || skb_shared(skb) || 516 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 517 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); 518 if (!new_skb) { 519 ip_rt_put(rt); 520 dev->stats.tx_dropped++; 521 dev_kfree_skb(skb); 522 return NETDEV_TX_OK; 523 } 524 if (skb->sk) 525 skb_set_owner_w(new_skb, skb->sk); 526 dev_kfree_skb(skb); 527 skb = new_skb; 528 old_iph = ip_hdr(skb); 529 } 530 531 skb->transport_header = skb->network_header; 532 skb_push(skb, sizeof(struct iphdr)); 533 skb_reset_network_header(skb); 534 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); 535 IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | 536 IPSKB_REROUTED); 537 skb_dst_drop(skb); 538 skb_dst_set(skb, &rt->dst); 539 540 /* 541 * Push down and install the IPIP header. 542 */ 543 544 iph = ip_hdr(skb); 545 iph->version = 4; 546 iph->ihl = sizeof(struct iphdr)>>2; 547 iph->frag_off = df; 548 iph->protocol = IPPROTO_IPIP; 549 iph->tos = INET_ECN_encapsulate(tos, old_iph->tos); 550 iph->daddr = fl4.daddr; 551 iph->saddr = fl4.saddr; 552 553 if ((iph->ttl = tiph->ttl) == 0) 554 iph->ttl = old_iph->ttl; 555 556 nf_reset(skb); 557 tstats = this_cpu_ptr(dev->tstats); 558 __IPTUNNEL_XMIT(tstats, &dev->stats); 559 return NETDEV_TX_OK; 560 561 tx_error_icmp: 562 dst_link_failure(skb); 563 tx_error: 564 dev->stats.tx_errors++; 565 dev_kfree_skb(skb); 566 return NETDEV_TX_OK; 567 } 568 569 static void ipip_tunnel_bind_dev(struct net_device *dev) 570 { 571 struct net_device *tdev = NULL; 572 struct ip_tunnel *tunnel; 573 const struct iphdr *iph; 574 575 tunnel = netdev_priv(dev); 576 iph = &tunnel->parms.iph; 577 578 if (iph->daddr) { 579 struct rtable *rt; 580 struct flowi4 fl4; 581 582 rt = ip_route_output_ports(dev_net(dev), &fl4, NULL, 583 iph->daddr, iph->saddr, 584 0, 0, 585 IPPROTO_IPIP, 586 RT_TOS(iph->tos), 587 tunnel->parms.link); 588 if (!IS_ERR(rt)) { 589 tdev = rt->dst.dev; 590 ip_rt_put(rt); 591 } 592 dev->flags |= IFF_POINTOPOINT; 593 } 594 595 if (!tdev && tunnel->parms.link) 596 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link); 597 598 if (tdev) { 599 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); 600 dev->mtu = tdev->mtu - sizeof(struct iphdr); 601 } 602 dev->iflink = tunnel->parms.link; 603 } 604 605 static int 606 ipip_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) 607 { 608 int err = 0; 609 struct ip_tunnel_parm p; 610 struct ip_tunnel *t; 611 struct net *net = dev_net(dev); 612 struct ipip_net *ipn = net_generic(net, ipip_net_id); 613 614 switch (cmd) { 615 case SIOCGETTUNNEL: 616 t = NULL; 617 if (dev == ipn->fb_tunnel_dev) { 618 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 619 err = -EFAULT; 620 break; 621 } 622 t = ipip_tunnel_locate(net, &p, 0); 623 } 624 if (t == NULL) 625 t = netdev_priv(dev); 626 memcpy(&p, &t->parms, sizeof(p)); 627 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 628 err = -EFAULT; 629 break; 630 631 case SIOCADDTUNNEL: 632 case SIOCCHGTUNNEL: 633 err = -EPERM; 634 if (!capable(CAP_NET_ADMIN)) 635 goto done; 636 637 err = -EFAULT; 638 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 639 goto done; 640 641 err = -EINVAL; 642 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP || 643 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) 644 goto done; 645 if (p.iph.ttl) 646 p.iph.frag_off |= htons(IP_DF); 647 648 t = ipip_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL); 649 650 if (dev != ipn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 651 if (t != NULL) { 652 if (t->dev != dev) { 653 err = -EEXIST; 654 break; 655 } 656 } else { 657 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || 658 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { 659 err = -EINVAL; 660 break; 661 } 662 t = netdev_priv(dev); 663 ipip_tunnel_unlink(ipn, t); 664 synchronize_net(); 665 t->parms.iph.saddr = p.iph.saddr; 666 t->parms.iph.daddr = p.iph.daddr; 667 memcpy(dev->dev_addr, &p.iph.saddr, 4); 668 memcpy(dev->broadcast, &p.iph.daddr, 4); 669 ipip_tunnel_link(ipn, t); 670 netdev_state_change(dev); 671 } 672 } 673 674 if (t) { 675 err = 0; 676 if (cmd == SIOCCHGTUNNEL) { 677 t->parms.iph.ttl = p.iph.ttl; 678 t->parms.iph.tos = p.iph.tos; 679 t->parms.iph.frag_off = p.iph.frag_off; 680 if (t->parms.link != p.link) { 681 t->parms.link = p.link; 682 ipip_tunnel_bind_dev(dev); 683 netdev_state_change(dev); 684 } 685 } 686 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) 687 err = -EFAULT; 688 } else 689 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 690 break; 691 692 case SIOCDELTUNNEL: 693 err = -EPERM; 694 if (!capable(CAP_NET_ADMIN)) 695 goto done; 696 697 if (dev == ipn->fb_tunnel_dev) { 698 err = -EFAULT; 699 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 700 goto done; 701 err = -ENOENT; 702 if ((t = ipip_tunnel_locate(net, &p, 0)) == NULL) 703 goto done; 704 err = -EPERM; 705 if (t->dev == ipn->fb_tunnel_dev) 706 goto done; 707 dev = t->dev; 708 } 709 unregister_netdevice(dev); 710 err = 0; 711 break; 712 713 default: 714 err = -EINVAL; 715 } 716 717 done: 718 return err; 719 } 720 721 static int ipip_tunnel_change_mtu(struct net_device *dev, int new_mtu) 722 { 723 if (new_mtu < 68 || new_mtu > 0xFFF8 - sizeof(struct iphdr)) 724 return -EINVAL; 725 dev->mtu = new_mtu; 726 return 0; 727 } 728 729 static const struct net_device_ops ipip_netdev_ops = { 730 .ndo_uninit = ipip_tunnel_uninit, 731 .ndo_start_xmit = ipip_tunnel_xmit, 732 .ndo_do_ioctl = ipip_tunnel_ioctl, 733 .ndo_change_mtu = ipip_tunnel_change_mtu, 734 .ndo_get_stats = ipip_get_stats, 735 }; 736 737 static void ipip_dev_free(struct net_device *dev) 738 { 739 free_percpu(dev->tstats); 740 free_netdev(dev); 741 } 742 743 static void ipip_tunnel_setup(struct net_device *dev) 744 { 745 dev->netdev_ops = &ipip_netdev_ops; 746 dev->destructor = ipip_dev_free; 747 748 dev->type = ARPHRD_TUNNEL; 749 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); 750 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr); 751 dev->flags = IFF_NOARP; 752 dev->iflink = 0; 753 dev->addr_len = 4; 754 dev->features |= NETIF_F_NETNS_LOCAL; 755 dev->features |= NETIF_F_LLTX; 756 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; 757 } 758 759 static int ipip_tunnel_init(struct net_device *dev) 760 { 761 struct ip_tunnel *tunnel = netdev_priv(dev); 762 763 tunnel->dev = dev; 764 765 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); 766 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); 767 768 ipip_tunnel_bind_dev(dev); 769 770 dev->tstats = alloc_percpu(struct pcpu_tstats); 771 if (!dev->tstats) 772 return -ENOMEM; 773 774 return 0; 775 } 776 777 static int __net_init ipip_fb_tunnel_init(struct net_device *dev) 778 { 779 struct ip_tunnel *tunnel = netdev_priv(dev); 780 struct iphdr *iph = &tunnel->parms.iph; 781 struct ipip_net *ipn = net_generic(dev_net(dev), ipip_net_id); 782 783 tunnel->dev = dev; 784 strcpy(tunnel->parms.name, dev->name); 785 786 iph->version = 4; 787 iph->protocol = IPPROTO_IPIP; 788 iph->ihl = 5; 789 790 dev->tstats = alloc_percpu(struct pcpu_tstats); 791 if (!dev->tstats) 792 return -ENOMEM; 793 794 dev_hold(dev); 795 rcu_assign_pointer(ipn->tunnels_wc[0], tunnel); 796 return 0; 797 } 798 799 static struct xfrm_tunnel ipip_handler __read_mostly = { 800 .handler = ipip_rcv, 801 .err_handler = ipip_err, 802 .priority = 1, 803 }; 804 805 static const char banner[] __initconst = 806 KERN_INFO "IPv4 over IPv4 tunneling driver\n"; 807 808 static void ipip_destroy_tunnels(struct ipip_net *ipn, struct list_head *head) 809 { 810 int prio; 811 812 for (prio = 1; prio < 4; prio++) { 813 int h; 814 for (h = 0; h < HASH_SIZE; h++) { 815 struct ip_tunnel *t; 816 817 t = rtnl_dereference(ipn->tunnels[prio][h]); 818 while (t != NULL) { 819 unregister_netdevice_queue(t->dev, head); 820 t = rtnl_dereference(t->next); 821 } 822 } 823 } 824 } 825 826 static int __net_init ipip_init_net(struct net *net) 827 { 828 struct ipip_net *ipn = net_generic(net, ipip_net_id); 829 struct ip_tunnel *t; 830 int err; 831 832 ipn->tunnels[0] = ipn->tunnels_wc; 833 ipn->tunnels[1] = ipn->tunnels_l; 834 ipn->tunnels[2] = ipn->tunnels_r; 835 ipn->tunnels[3] = ipn->tunnels_r_l; 836 837 ipn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), 838 "tunl0", 839 ipip_tunnel_setup); 840 if (!ipn->fb_tunnel_dev) { 841 err = -ENOMEM; 842 goto err_alloc_dev; 843 } 844 dev_net_set(ipn->fb_tunnel_dev, net); 845 846 err = ipip_fb_tunnel_init(ipn->fb_tunnel_dev); 847 if (err) 848 goto err_reg_dev; 849 850 if ((err = register_netdev(ipn->fb_tunnel_dev))) 851 goto err_reg_dev; 852 853 t = netdev_priv(ipn->fb_tunnel_dev); 854 855 strcpy(t->parms.name, ipn->fb_tunnel_dev->name); 856 return 0; 857 858 err_reg_dev: 859 ipip_dev_free(ipn->fb_tunnel_dev); 860 err_alloc_dev: 861 /* nothing */ 862 return err; 863 } 864 865 static void __net_exit ipip_exit_net(struct net *net) 866 { 867 struct ipip_net *ipn = net_generic(net, ipip_net_id); 868 LIST_HEAD(list); 869 870 rtnl_lock(); 871 ipip_destroy_tunnels(ipn, &list); 872 unregister_netdevice_queue(ipn->fb_tunnel_dev, &list); 873 unregister_netdevice_many(&list); 874 rtnl_unlock(); 875 } 876 877 static struct pernet_operations ipip_net_ops = { 878 .init = ipip_init_net, 879 .exit = ipip_exit_net, 880 .id = &ipip_net_id, 881 .size = sizeof(struct ipip_net), 882 }; 883 884 static int __init ipip_init(void) 885 { 886 int err; 887 888 printk(banner); 889 890 err = register_pernet_device(&ipip_net_ops); 891 if (err < 0) 892 return err; 893 err = xfrm4_tunnel_register(&ipip_handler, AF_INET); 894 if (err < 0) { 895 unregister_pernet_device(&ipip_net_ops); 896 printk(KERN_INFO "ipip init: can't register tunnel\n"); 897 } 898 return err; 899 } 900 901 static void __exit ipip_fini(void) 902 { 903 if (xfrm4_tunnel_deregister(&ipip_handler, AF_INET)) 904 printk(KERN_INFO "ipip close: can't deregister tunnel\n"); 905 906 unregister_pernet_device(&ipip_net_ops); 907 } 908 909 module_init(ipip_init); 910 module_exit(ipip_fini); 911 MODULE_LICENSE("GPL"); 912 MODULE_ALIAS_NETDEV("tunl0"); 913