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