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 bool log_ecn_error = true; 124 module_param(log_ecn_error, bool, 0644); 125 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN"); 126 127 static int ipip_net_id __read_mostly; 128 struct ipip_net { 129 struct ip_tunnel __rcu *tunnels_r_l[HASH_SIZE]; 130 struct ip_tunnel __rcu *tunnels_r[HASH_SIZE]; 131 struct ip_tunnel __rcu *tunnels_l[HASH_SIZE]; 132 struct ip_tunnel __rcu *tunnels_wc[1]; 133 struct ip_tunnel __rcu **tunnels[4]; 134 135 struct net_device *fb_tunnel_dev; 136 }; 137 138 static int ipip_tunnel_init(struct net_device *dev); 139 static void ipip_tunnel_setup(struct net_device *dev); 140 static void ipip_dev_free(struct net_device *dev); 141 142 /* 143 * Locking : hash tables are protected by RCU and RTNL 144 */ 145 146 #define for_each_ip_tunnel_rcu(start) \ 147 for (t = rcu_dereference(start); t; t = rcu_dereference(t->next)) 148 149 /* often modified stats are per cpu, other are shared (netdev->stats) */ 150 struct pcpu_tstats { 151 u64 rx_packets; 152 u64 rx_bytes; 153 u64 tx_packets; 154 u64 tx_bytes; 155 struct u64_stats_sync syncp; 156 }; 157 158 static struct rtnl_link_stats64 *ipip_get_stats64(struct net_device *dev, 159 struct rtnl_link_stats64 *tot) 160 { 161 int i; 162 163 for_each_possible_cpu(i) { 164 const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i); 165 u64 rx_packets, rx_bytes, tx_packets, tx_bytes; 166 unsigned int start; 167 168 do { 169 start = u64_stats_fetch_begin_bh(&tstats->syncp); 170 rx_packets = tstats->rx_packets; 171 tx_packets = tstats->tx_packets; 172 rx_bytes = tstats->rx_bytes; 173 tx_bytes = tstats->tx_bytes; 174 } while (u64_stats_fetch_retry_bh(&tstats->syncp, start)); 175 176 tot->rx_packets += rx_packets; 177 tot->tx_packets += tx_packets; 178 tot->rx_bytes += rx_bytes; 179 tot->tx_bytes += tx_bytes; 180 } 181 182 tot->tx_fifo_errors = dev->stats.tx_fifo_errors; 183 tot->tx_carrier_errors = dev->stats.tx_carrier_errors; 184 tot->tx_dropped = dev->stats.tx_dropped; 185 tot->tx_aborted_errors = dev->stats.tx_aborted_errors; 186 tot->tx_errors = dev->stats.tx_errors; 187 tot->collisions = dev->stats.collisions; 188 189 return tot; 190 } 191 192 static struct ip_tunnel *ipip_tunnel_lookup(struct net *net, 193 __be32 remote, __be32 local) 194 { 195 unsigned int h0 = HASH(remote); 196 unsigned int h1 = HASH(local); 197 struct ip_tunnel *t; 198 struct ipip_net *ipn = net_generic(net, ipip_net_id); 199 200 for_each_ip_tunnel_rcu(ipn->tunnels_r_l[h0 ^ h1]) 201 if (local == t->parms.iph.saddr && 202 remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP)) 203 return t; 204 205 for_each_ip_tunnel_rcu(ipn->tunnels_r[h0]) 206 if (remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP)) 207 return t; 208 209 for_each_ip_tunnel_rcu(ipn->tunnels_l[h1]) 210 if (local == t->parms.iph.saddr && (t->dev->flags&IFF_UP)) 211 return t; 212 213 t = rcu_dereference(ipn->tunnels_wc[0]); 214 if (t && (t->dev->flags&IFF_UP)) 215 return t; 216 return NULL; 217 } 218 219 static struct ip_tunnel __rcu **__ipip_bucket(struct ipip_net *ipn, 220 struct ip_tunnel_parm *parms) 221 { 222 __be32 remote = parms->iph.daddr; 223 __be32 local = parms->iph.saddr; 224 unsigned int h = 0; 225 int prio = 0; 226 227 if (remote) { 228 prio |= 2; 229 h ^= HASH(remote); 230 } 231 if (local) { 232 prio |= 1; 233 h ^= HASH(local); 234 } 235 return &ipn->tunnels[prio][h]; 236 } 237 238 static inline struct ip_tunnel __rcu **ipip_bucket(struct ipip_net *ipn, 239 struct ip_tunnel *t) 240 { 241 return __ipip_bucket(ipn, &t->parms); 242 } 243 244 static void ipip_tunnel_unlink(struct ipip_net *ipn, struct ip_tunnel *t) 245 { 246 struct ip_tunnel __rcu **tp; 247 struct ip_tunnel *iter; 248 249 for (tp = ipip_bucket(ipn, t); 250 (iter = rtnl_dereference(*tp)) != NULL; 251 tp = &iter->next) { 252 if (t == iter) { 253 rcu_assign_pointer(*tp, t->next); 254 break; 255 } 256 } 257 } 258 259 static void ipip_tunnel_link(struct ipip_net *ipn, struct ip_tunnel *t) 260 { 261 struct ip_tunnel __rcu **tp = ipip_bucket(ipn, t); 262 263 rcu_assign_pointer(t->next, rtnl_dereference(*tp)); 264 rcu_assign_pointer(*tp, t); 265 } 266 267 static struct ip_tunnel *ipip_tunnel_locate(struct net *net, 268 struct ip_tunnel_parm *parms, int create) 269 { 270 __be32 remote = parms->iph.daddr; 271 __be32 local = parms->iph.saddr; 272 struct ip_tunnel *t, *nt; 273 struct ip_tunnel __rcu **tp; 274 struct net_device *dev; 275 char name[IFNAMSIZ]; 276 struct ipip_net *ipn = net_generic(net, ipip_net_id); 277 278 for (tp = __ipip_bucket(ipn, parms); 279 (t = rtnl_dereference(*tp)) != NULL; 280 tp = &t->next) { 281 if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr) 282 return t; 283 } 284 if (!create) 285 return NULL; 286 287 if (parms->name[0]) 288 strlcpy(name, parms->name, IFNAMSIZ); 289 else 290 strcpy(name, "tunl%d"); 291 292 dev = alloc_netdev(sizeof(*t), name, ipip_tunnel_setup); 293 if (dev == NULL) 294 return NULL; 295 296 dev_net_set(dev, net); 297 298 nt = netdev_priv(dev); 299 nt->parms = *parms; 300 301 if (ipip_tunnel_init(dev) < 0) 302 goto failed_free; 303 304 if (register_netdevice(dev) < 0) 305 goto failed_free; 306 307 strcpy(nt->parms.name, dev->name); 308 309 dev_hold(dev); 310 ipip_tunnel_link(ipn, nt); 311 return nt; 312 313 failed_free: 314 ipip_dev_free(dev); 315 return NULL; 316 } 317 318 /* called with RTNL */ 319 static void ipip_tunnel_uninit(struct net_device *dev) 320 { 321 struct net *net = dev_net(dev); 322 struct ipip_net *ipn = net_generic(net, ipip_net_id); 323 324 if (dev == ipn->fb_tunnel_dev) 325 RCU_INIT_POINTER(ipn->tunnels_wc[0], NULL); 326 else 327 ipip_tunnel_unlink(ipn, netdev_priv(dev)); 328 dev_put(dev); 329 } 330 331 static int ipip_err(struct sk_buff *skb, u32 info) 332 { 333 334 /* All the routers (except for Linux) return only 335 8 bytes of packet payload. It means, that precise relaying of 336 ICMP in the real Internet is absolutely infeasible. 337 */ 338 const struct iphdr *iph = (const struct iphdr *)skb->data; 339 const int type = icmp_hdr(skb)->type; 340 const int code = icmp_hdr(skb)->code; 341 struct ip_tunnel *t; 342 int err; 343 344 switch (type) { 345 default: 346 case ICMP_PARAMETERPROB: 347 return 0; 348 349 case ICMP_DEST_UNREACH: 350 switch (code) { 351 case ICMP_SR_FAILED: 352 case ICMP_PORT_UNREACH: 353 /* Impossible event. */ 354 return 0; 355 default: 356 /* All others are translated to HOST_UNREACH. 357 rfc2003 contains "deep thoughts" about NET_UNREACH, 358 I believe they are just ether pollution. --ANK 359 */ 360 break; 361 } 362 break; 363 case ICMP_TIME_EXCEEDED: 364 if (code != ICMP_EXC_TTL) 365 return 0; 366 break; 367 case ICMP_REDIRECT: 368 break; 369 } 370 371 err = -ENOENT; 372 t = ipip_tunnel_lookup(dev_net(skb->dev), iph->daddr, iph->saddr); 373 if (t == NULL) 374 goto out; 375 376 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { 377 ipv4_update_pmtu(skb, dev_net(skb->dev), info, 378 t->dev->ifindex, 0, IPPROTO_IPIP, 0); 379 err = 0; 380 goto out; 381 } 382 383 if (type == ICMP_REDIRECT) { 384 ipv4_redirect(skb, dev_net(skb->dev), t->dev->ifindex, 0, 385 IPPROTO_IPIP, 0); 386 err = 0; 387 goto out; 388 } 389 390 if (t->parms.iph.daddr == 0) 391 goto out; 392 393 err = 0; 394 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 395 goto out; 396 397 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) 398 t->err_count++; 399 else 400 t->err_count = 1; 401 t->err_time = jiffies; 402 out: 403 404 return err; 405 } 406 407 static int ipip_rcv(struct sk_buff *skb) 408 { 409 struct ip_tunnel *tunnel; 410 const struct iphdr *iph = ip_hdr(skb); 411 int err; 412 413 tunnel = ipip_tunnel_lookup(dev_net(skb->dev), iph->saddr, iph->daddr); 414 if (tunnel != NULL) { 415 struct pcpu_tstats *tstats; 416 417 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) 418 goto drop; 419 420 secpath_reset(skb); 421 422 skb->mac_header = skb->network_header; 423 skb_reset_network_header(skb); 424 skb->protocol = htons(ETH_P_IP); 425 skb->pkt_type = PACKET_HOST; 426 427 __skb_tunnel_rx(skb, tunnel->dev); 428 429 err = IP_ECN_decapsulate(iph, skb); 430 if (unlikely(err)) { 431 if (log_ecn_error) 432 net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n", 433 &iph->saddr, iph->tos); 434 if (err > 1) { 435 ++tunnel->dev->stats.rx_frame_errors; 436 ++tunnel->dev->stats.rx_errors; 437 goto drop; 438 } 439 } 440 441 tstats = this_cpu_ptr(tunnel->dev->tstats); 442 u64_stats_update_begin(&tstats->syncp); 443 tstats->rx_packets++; 444 tstats->rx_bytes += skb->len; 445 u64_stats_update_end(&tstats->syncp); 446 447 netif_rx(skb); 448 return 0; 449 } 450 451 return -1; 452 453 drop: 454 kfree_skb(skb); 455 return 0; 456 } 457 458 /* 459 * This function assumes it is being called from dev_queue_xmit() 460 * and that skb is filled properly by that function. 461 */ 462 463 static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) 464 { 465 struct ip_tunnel *tunnel = netdev_priv(dev); 466 struct pcpu_tstats *tstats; 467 const struct iphdr *tiph = &tunnel->parms.iph; 468 u8 tos = tunnel->parms.iph.tos; 469 __be16 df = tiph->frag_off; 470 struct rtable *rt; /* Route to the other host */ 471 struct net_device *tdev; /* Device to other host */ 472 const struct iphdr *old_iph = ip_hdr(skb); 473 struct iphdr *iph; /* Our new IP header */ 474 unsigned int max_headroom; /* The extra header space needed */ 475 __be32 dst = tiph->daddr; 476 struct flowi4 fl4; 477 int mtu; 478 479 if (skb->protocol != htons(ETH_P_IP)) 480 goto tx_error; 481 482 if (tos & 1) 483 tos = old_iph->tos; 484 485 if (!dst) { 486 /* NBMA tunnel */ 487 if ((rt = skb_rtable(skb)) == NULL) { 488 dev->stats.tx_fifo_errors++; 489 goto tx_error; 490 } 491 dst = rt_nexthop(rt, old_iph->daddr); 492 } 493 494 rt = ip_route_output_ports(dev_net(dev), &fl4, NULL, 495 dst, tiph->saddr, 496 0, 0, 497 IPPROTO_IPIP, RT_TOS(tos), 498 tunnel->parms.link); 499 if (IS_ERR(rt)) { 500 dev->stats.tx_carrier_errors++; 501 goto tx_error_icmp; 502 } 503 tdev = rt->dst.dev; 504 505 if (tdev == dev) { 506 ip_rt_put(rt); 507 dev->stats.collisions++; 508 goto tx_error; 509 } 510 511 df |= old_iph->frag_off & htons(IP_DF); 512 513 if (df) { 514 mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr); 515 516 if (mtu < 68) { 517 dev->stats.collisions++; 518 ip_rt_put(rt); 519 goto tx_error; 520 } 521 522 if (skb_dst(skb)) 523 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu); 524 525 if ((old_iph->frag_off & htons(IP_DF)) && 526 mtu < ntohs(old_iph->tot_len)) { 527 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, 528 htonl(mtu)); 529 ip_rt_put(rt); 530 goto tx_error; 531 } 532 } 533 534 if (tunnel->err_count > 0) { 535 if (time_before(jiffies, 536 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { 537 tunnel->err_count--; 538 dst_link_failure(skb); 539 } else 540 tunnel->err_count = 0; 541 } 542 543 /* 544 * Okay, now see if we can stuff it in the buffer as-is. 545 */ 546 max_headroom = (LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr)); 547 548 if (skb_headroom(skb) < max_headroom || skb_shared(skb) || 549 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 550 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); 551 if (!new_skb) { 552 ip_rt_put(rt); 553 dev->stats.tx_dropped++; 554 dev_kfree_skb(skb); 555 return NETDEV_TX_OK; 556 } 557 if (skb->sk) 558 skb_set_owner_w(new_skb, skb->sk); 559 dev_kfree_skb(skb); 560 skb = new_skb; 561 old_iph = ip_hdr(skb); 562 } 563 564 skb->transport_header = skb->network_header; 565 skb_push(skb, sizeof(struct iphdr)); 566 skb_reset_network_header(skb); 567 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); 568 IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | 569 IPSKB_REROUTED); 570 skb_dst_drop(skb); 571 skb_dst_set(skb, &rt->dst); 572 573 /* 574 * Push down and install the IPIP header. 575 */ 576 577 iph = ip_hdr(skb); 578 iph->version = 4; 579 iph->ihl = sizeof(struct iphdr)>>2; 580 iph->frag_off = df; 581 iph->protocol = IPPROTO_IPIP; 582 iph->tos = INET_ECN_encapsulate(tos, old_iph->tos); 583 iph->daddr = fl4.daddr; 584 iph->saddr = fl4.saddr; 585 586 if ((iph->ttl = tiph->ttl) == 0) 587 iph->ttl = old_iph->ttl; 588 589 nf_reset(skb); 590 tstats = this_cpu_ptr(dev->tstats); 591 __IPTUNNEL_XMIT(tstats, &dev->stats); 592 return NETDEV_TX_OK; 593 594 tx_error_icmp: 595 dst_link_failure(skb); 596 tx_error: 597 dev->stats.tx_errors++; 598 dev_kfree_skb(skb); 599 return NETDEV_TX_OK; 600 } 601 602 static void ipip_tunnel_bind_dev(struct net_device *dev) 603 { 604 struct net_device *tdev = NULL; 605 struct ip_tunnel *tunnel; 606 const struct iphdr *iph; 607 608 tunnel = netdev_priv(dev); 609 iph = &tunnel->parms.iph; 610 611 if (iph->daddr) { 612 struct rtable *rt; 613 struct flowi4 fl4; 614 615 rt = ip_route_output_ports(dev_net(dev), &fl4, NULL, 616 iph->daddr, iph->saddr, 617 0, 0, 618 IPPROTO_IPIP, 619 RT_TOS(iph->tos), 620 tunnel->parms.link); 621 if (!IS_ERR(rt)) { 622 tdev = rt->dst.dev; 623 ip_rt_put(rt); 624 } 625 dev->flags |= IFF_POINTOPOINT; 626 } 627 628 if (!tdev && tunnel->parms.link) 629 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link); 630 631 if (tdev) { 632 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); 633 dev->mtu = tdev->mtu - sizeof(struct iphdr); 634 } 635 dev->iflink = tunnel->parms.link; 636 } 637 638 static int 639 ipip_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) 640 { 641 int err = 0; 642 struct ip_tunnel_parm p; 643 struct ip_tunnel *t; 644 struct net *net = dev_net(dev); 645 struct ipip_net *ipn = net_generic(net, ipip_net_id); 646 647 switch (cmd) { 648 case SIOCGETTUNNEL: 649 t = NULL; 650 if (dev == ipn->fb_tunnel_dev) { 651 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 652 err = -EFAULT; 653 break; 654 } 655 t = ipip_tunnel_locate(net, &p, 0); 656 } 657 if (t == NULL) 658 t = netdev_priv(dev); 659 memcpy(&p, &t->parms, sizeof(p)); 660 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 661 err = -EFAULT; 662 break; 663 664 case SIOCADDTUNNEL: 665 case SIOCCHGTUNNEL: 666 err = -EPERM; 667 if (!capable(CAP_NET_ADMIN)) 668 goto done; 669 670 err = -EFAULT; 671 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 672 goto done; 673 674 err = -EINVAL; 675 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP || 676 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) 677 goto done; 678 if (p.iph.ttl) 679 p.iph.frag_off |= htons(IP_DF); 680 681 t = ipip_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL); 682 683 if (dev != ipn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 684 if (t != NULL) { 685 if (t->dev != dev) { 686 err = -EEXIST; 687 break; 688 } 689 } else { 690 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || 691 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { 692 err = -EINVAL; 693 break; 694 } 695 t = netdev_priv(dev); 696 ipip_tunnel_unlink(ipn, t); 697 synchronize_net(); 698 t->parms.iph.saddr = p.iph.saddr; 699 t->parms.iph.daddr = p.iph.daddr; 700 memcpy(dev->dev_addr, &p.iph.saddr, 4); 701 memcpy(dev->broadcast, &p.iph.daddr, 4); 702 ipip_tunnel_link(ipn, t); 703 netdev_state_change(dev); 704 } 705 } 706 707 if (t) { 708 err = 0; 709 if (cmd == SIOCCHGTUNNEL) { 710 t->parms.iph.ttl = p.iph.ttl; 711 t->parms.iph.tos = p.iph.tos; 712 t->parms.iph.frag_off = p.iph.frag_off; 713 if (t->parms.link != p.link) { 714 t->parms.link = p.link; 715 ipip_tunnel_bind_dev(dev); 716 netdev_state_change(dev); 717 } 718 } 719 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) 720 err = -EFAULT; 721 } else 722 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 723 break; 724 725 case SIOCDELTUNNEL: 726 err = -EPERM; 727 if (!capable(CAP_NET_ADMIN)) 728 goto done; 729 730 if (dev == ipn->fb_tunnel_dev) { 731 err = -EFAULT; 732 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 733 goto done; 734 err = -ENOENT; 735 if ((t = ipip_tunnel_locate(net, &p, 0)) == NULL) 736 goto done; 737 err = -EPERM; 738 if (t->dev == ipn->fb_tunnel_dev) 739 goto done; 740 dev = t->dev; 741 } 742 unregister_netdevice(dev); 743 err = 0; 744 break; 745 746 default: 747 err = -EINVAL; 748 } 749 750 done: 751 return err; 752 } 753 754 static int ipip_tunnel_change_mtu(struct net_device *dev, int new_mtu) 755 { 756 if (new_mtu < 68 || new_mtu > 0xFFF8 - sizeof(struct iphdr)) 757 return -EINVAL; 758 dev->mtu = new_mtu; 759 return 0; 760 } 761 762 static const struct net_device_ops ipip_netdev_ops = { 763 .ndo_uninit = ipip_tunnel_uninit, 764 .ndo_start_xmit = ipip_tunnel_xmit, 765 .ndo_do_ioctl = ipip_tunnel_ioctl, 766 .ndo_change_mtu = ipip_tunnel_change_mtu, 767 .ndo_get_stats64 = ipip_get_stats64, 768 }; 769 770 static void ipip_dev_free(struct net_device *dev) 771 { 772 free_percpu(dev->tstats); 773 free_netdev(dev); 774 } 775 776 static void ipip_tunnel_setup(struct net_device *dev) 777 { 778 dev->netdev_ops = &ipip_netdev_ops; 779 dev->destructor = ipip_dev_free; 780 781 dev->type = ARPHRD_TUNNEL; 782 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); 783 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr); 784 dev->flags = IFF_NOARP; 785 dev->iflink = 0; 786 dev->addr_len = 4; 787 dev->features |= NETIF_F_NETNS_LOCAL; 788 dev->features |= NETIF_F_LLTX; 789 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; 790 } 791 792 static int ipip_tunnel_init(struct net_device *dev) 793 { 794 struct ip_tunnel *tunnel = netdev_priv(dev); 795 796 tunnel->dev = dev; 797 798 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); 799 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); 800 801 ipip_tunnel_bind_dev(dev); 802 803 dev->tstats = alloc_percpu(struct pcpu_tstats); 804 if (!dev->tstats) 805 return -ENOMEM; 806 807 return 0; 808 } 809 810 static int __net_init ipip_fb_tunnel_init(struct net_device *dev) 811 { 812 struct ip_tunnel *tunnel = netdev_priv(dev); 813 struct iphdr *iph = &tunnel->parms.iph; 814 struct ipip_net *ipn = net_generic(dev_net(dev), ipip_net_id); 815 816 tunnel->dev = dev; 817 strcpy(tunnel->parms.name, dev->name); 818 819 iph->version = 4; 820 iph->protocol = IPPROTO_IPIP; 821 iph->ihl = 5; 822 823 dev->tstats = alloc_percpu(struct pcpu_tstats); 824 if (!dev->tstats) 825 return -ENOMEM; 826 827 dev_hold(dev); 828 rcu_assign_pointer(ipn->tunnels_wc[0], tunnel); 829 return 0; 830 } 831 832 static struct xfrm_tunnel ipip_handler __read_mostly = { 833 .handler = ipip_rcv, 834 .err_handler = ipip_err, 835 .priority = 1, 836 }; 837 838 static const char banner[] __initconst = 839 KERN_INFO "IPv4 over IPv4 tunneling driver\n"; 840 841 static void ipip_destroy_tunnels(struct ipip_net *ipn, struct list_head *head) 842 { 843 int prio; 844 845 for (prio = 1; prio < 4; prio++) { 846 int h; 847 for (h = 0; h < HASH_SIZE; h++) { 848 struct ip_tunnel *t; 849 850 t = rtnl_dereference(ipn->tunnels[prio][h]); 851 while (t != NULL) { 852 unregister_netdevice_queue(t->dev, head); 853 t = rtnl_dereference(t->next); 854 } 855 } 856 } 857 } 858 859 static int __net_init ipip_init_net(struct net *net) 860 { 861 struct ipip_net *ipn = net_generic(net, ipip_net_id); 862 struct ip_tunnel *t; 863 int err; 864 865 ipn->tunnels[0] = ipn->tunnels_wc; 866 ipn->tunnels[1] = ipn->tunnels_l; 867 ipn->tunnels[2] = ipn->tunnels_r; 868 ipn->tunnels[3] = ipn->tunnels_r_l; 869 870 ipn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), 871 "tunl0", 872 ipip_tunnel_setup); 873 if (!ipn->fb_tunnel_dev) { 874 err = -ENOMEM; 875 goto err_alloc_dev; 876 } 877 dev_net_set(ipn->fb_tunnel_dev, net); 878 879 err = ipip_fb_tunnel_init(ipn->fb_tunnel_dev); 880 if (err) 881 goto err_reg_dev; 882 883 if ((err = register_netdev(ipn->fb_tunnel_dev))) 884 goto err_reg_dev; 885 886 t = netdev_priv(ipn->fb_tunnel_dev); 887 888 strcpy(t->parms.name, ipn->fb_tunnel_dev->name); 889 return 0; 890 891 err_reg_dev: 892 ipip_dev_free(ipn->fb_tunnel_dev); 893 err_alloc_dev: 894 /* nothing */ 895 return err; 896 } 897 898 static void __net_exit ipip_exit_net(struct net *net) 899 { 900 struct ipip_net *ipn = net_generic(net, ipip_net_id); 901 LIST_HEAD(list); 902 903 rtnl_lock(); 904 ipip_destroy_tunnels(ipn, &list); 905 unregister_netdevice_queue(ipn->fb_tunnel_dev, &list); 906 unregister_netdevice_many(&list); 907 rtnl_unlock(); 908 } 909 910 static struct pernet_operations ipip_net_ops = { 911 .init = ipip_init_net, 912 .exit = ipip_exit_net, 913 .id = &ipip_net_id, 914 .size = sizeof(struct ipip_net), 915 }; 916 917 static int __init ipip_init(void) 918 { 919 int err; 920 921 printk(banner); 922 923 err = register_pernet_device(&ipip_net_ops); 924 if (err < 0) 925 return err; 926 err = xfrm4_tunnel_register(&ipip_handler, AF_INET); 927 if (err < 0) { 928 unregister_pernet_device(&ipip_net_ops); 929 pr_info("%s: can't register tunnel\n", __func__); 930 } 931 return err; 932 } 933 934 static void __exit ipip_fini(void) 935 { 936 if (xfrm4_tunnel_deregister(&ipip_handler, AF_INET)) 937 pr_info("%s: can't deregister tunnel\n", __func__); 938 939 unregister_pernet_device(&ipip_net_ops); 940 } 941 942 module_init(ipip_init); 943 module_exit(ipip_fini); 944 MODULE_LICENSE("GPL"); 945 MODULE_ALIAS_NETDEV("tunl0"); 946