1 /* 2 * Linux NET3: GRE over IP protocol decoder. 3 * 4 * Authors: Alexey Kuznetsov (kuznet@ms2.inr.ac.ru) 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 * 11 */ 12 13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 14 15 #include <linux/capability.h> 16 #include <linux/module.h> 17 #include <linux/types.h> 18 #include <linux/kernel.h> 19 #include <linux/slab.h> 20 #include <asm/uaccess.h> 21 #include <linux/skbuff.h> 22 #include <linux/netdevice.h> 23 #include <linux/in.h> 24 #include <linux/tcp.h> 25 #include <linux/udp.h> 26 #include <linux/if_arp.h> 27 #include <linux/mroute.h> 28 #include <linux/init.h> 29 #include <linux/in6.h> 30 #include <linux/inetdevice.h> 31 #include <linux/igmp.h> 32 #include <linux/netfilter_ipv4.h> 33 #include <linux/etherdevice.h> 34 #include <linux/if_ether.h> 35 36 #include <net/sock.h> 37 #include <net/ip.h> 38 #include <net/icmp.h> 39 #include <net/protocol.h> 40 #include <net/ip_tunnels.h> 41 #include <net/arp.h> 42 #include <net/checksum.h> 43 #include <net/dsfield.h> 44 #include <net/inet_ecn.h> 45 #include <net/xfrm.h> 46 #include <net/net_namespace.h> 47 #include <net/netns/generic.h> 48 #include <net/rtnetlink.h> 49 #include <net/gre.h> 50 51 #if IS_ENABLED(CONFIG_IPV6) 52 #include <net/ipv6.h> 53 #include <net/ip6_fib.h> 54 #include <net/ip6_route.h> 55 #endif 56 57 /* 58 Problems & solutions 59 -------------------- 60 61 1. The most important issue is detecting local dead loops. 62 They would cause complete host lockup in transmit, which 63 would be "resolved" by stack overflow or, if queueing is enabled, 64 with infinite looping in net_bh. 65 66 We cannot track such dead loops during route installation, 67 it is infeasible task. The most general solutions would be 68 to keep skb->encapsulation counter (sort of local ttl), 69 and silently drop packet when it expires. It is a good 70 solution, but it supposes maintaining new variable in ALL 71 skb, even if no tunneling is used. 72 73 Current solution: xmit_recursion breaks dead loops. This is a percpu 74 counter, since when we enter the first ndo_xmit(), cpu migration is 75 forbidden. We force an exit if this counter reaches RECURSION_LIMIT 76 77 2. Networking dead loops would not kill routers, but would really 78 kill network. IP hop limit plays role of "t->recursion" in this case, 79 if we copy it from packet being encapsulated to upper header. 80 It is very good solution, but it introduces two problems: 81 82 - Routing protocols, using packets with ttl=1 (OSPF, RIP2), 83 do not work over tunnels. 84 - traceroute does not work. I planned to relay ICMP from tunnel, 85 so that this problem would be solved and traceroute output 86 would even more informative. This idea appeared to be wrong: 87 only Linux complies to rfc1812 now (yes, guys, Linux is the only 88 true router now :-)), all routers (at least, in neighbourhood of mine) 89 return only 8 bytes of payload. It is the end. 90 91 Hence, if we want that OSPF worked or traceroute said something reasonable, 92 we should search for another solution. 93 94 One of them is to parse packet trying to detect inner encapsulation 95 made by our node. It is difficult or even impossible, especially, 96 taking into account fragmentation. TO be short, ttl is not solution at all. 97 98 Current solution: The solution was UNEXPECTEDLY SIMPLE. 99 We force DF flag on tunnels with preconfigured hop limit, 100 that is ALL. :-) Well, it does not remove the problem completely, 101 but exponential growth of network traffic is changed to linear 102 (branches, that exceed pmtu are pruned) and tunnel mtu 103 rapidly degrades to value <68, where looping stops. 104 Yes, it is not good if there exists a router in the loop, 105 which does not force DF, even when encapsulating packets have DF set. 106 But it is not our problem! Nobody could accuse us, we made 107 all that we could make. Even if it is your gated who injected 108 fatal route to network, even if it were you who configured 109 fatal static route: you are innocent. :-) 110 111 Alexey Kuznetsov. 112 */ 113 114 static bool log_ecn_error = true; 115 module_param(log_ecn_error, bool, 0644); 116 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN"); 117 118 static struct rtnl_link_ops ipgre_link_ops __read_mostly; 119 static int ipgre_tunnel_init(struct net_device *dev); 120 121 static int ipgre_net_id __read_mostly; 122 static int gre_tap_net_id __read_mostly; 123 124 static int ipgre_err(struct sk_buff *skb, u32 info, 125 const struct tnl_ptk_info *tpi) 126 { 127 128 /* All the routers (except for Linux) return only 129 8 bytes of packet payload. It means, that precise relaying of 130 ICMP in the real Internet is absolutely infeasible. 131 132 Moreover, Cisco "wise men" put GRE key to the third word 133 in GRE header. It makes impossible maintaining even soft 134 state for keyed GRE tunnels with enabled checksum. Tell 135 them "thank you". 136 137 Well, I wonder, rfc1812 was written by Cisco employee, 138 what the hell these idiots break standards established 139 by themselves??? 140 */ 141 struct net *net = dev_net(skb->dev); 142 struct ip_tunnel_net *itn; 143 const struct iphdr *iph; 144 const int type = icmp_hdr(skb)->type; 145 const int code = icmp_hdr(skb)->code; 146 struct ip_tunnel *t; 147 148 switch (type) { 149 default: 150 case ICMP_PARAMETERPROB: 151 return PACKET_RCVD; 152 153 case ICMP_DEST_UNREACH: 154 switch (code) { 155 case ICMP_SR_FAILED: 156 case ICMP_PORT_UNREACH: 157 /* Impossible event. */ 158 return PACKET_RCVD; 159 default: 160 /* All others are translated to HOST_UNREACH. 161 rfc2003 contains "deep thoughts" about NET_UNREACH, 162 I believe they are just ether pollution. --ANK 163 */ 164 break; 165 } 166 break; 167 case ICMP_TIME_EXCEEDED: 168 if (code != ICMP_EXC_TTL) 169 return PACKET_RCVD; 170 break; 171 172 case ICMP_REDIRECT: 173 break; 174 } 175 176 if (tpi->proto == htons(ETH_P_TEB)) 177 itn = net_generic(net, gre_tap_net_id); 178 else 179 itn = net_generic(net, ipgre_net_id); 180 181 iph = (const struct iphdr *)(icmp_hdr(skb) + 1); 182 t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags, 183 iph->daddr, iph->saddr, tpi->key); 184 185 if (t == NULL) 186 return PACKET_REJECT; 187 188 if (t->parms.iph.daddr == 0 || 189 ipv4_is_multicast(t->parms.iph.daddr)) 190 return PACKET_RCVD; 191 192 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 193 return PACKET_RCVD; 194 195 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) 196 t->err_count++; 197 else 198 t->err_count = 1; 199 t->err_time = jiffies; 200 return PACKET_RCVD; 201 } 202 203 static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi) 204 { 205 struct net *net = dev_net(skb->dev); 206 struct ip_tunnel_net *itn; 207 const struct iphdr *iph; 208 struct ip_tunnel *tunnel; 209 210 if (tpi->proto == htons(ETH_P_TEB)) 211 itn = net_generic(net, gre_tap_net_id); 212 else 213 itn = net_generic(net, ipgre_net_id); 214 215 iph = ip_hdr(skb); 216 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags, 217 iph->saddr, iph->daddr, tpi->key); 218 219 if (tunnel) { 220 skb_pop_mac_header(skb); 221 ip_tunnel_rcv(tunnel, skb, tpi, log_ecn_error); 222 return PACKET_RCVD; 223 } 224 return PACKET_REJECT; 225 } 226 227 static void __gre_xmit(struct sk_buff *skb, struct net_device *dev, 228 const struct iphdr *tnl_params, 229 __be16 proto) 230 { 231 struct ip_tunnel *tunnel = netdev_priv(dev); 232 struct tnl_ptk_info tpi; 233 234 tpi.flags = tunnel->parms.o_flags; 235 tpi.proto = proto; 236 tpi.key = tunnel->parms.o_key; 237 if (tunnel->parms.o_flags & TUNNEL_SEQ) 238 tunnel->o_seqno++; 239 tpi.seq = htonl(tunnel->o_seqno); 240 241 /* Push GRE header. */ 242 gre_build_header(skb, &tpi, tunnel->hlen); 243 244 ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol); 245 } 246 247 static netdev_tx_t ipgre_xmit(struct sk_buff *skb, 248 struct net_device *dev) 249 { 250 struct ip_tunnel *tunnel = netdev_priv(dev); 251 const struct iphdr *tnl_params; 252 253 skb = gre_handle_offloads(skb, !!(tunnel->parms.o_flags&TUNNEL_CSUM)); 254 if (IS_ERR(skb)) 255 goto out; 256 257 if (dev->header_ops) { 258 /* Need space for new headers */ 259 if (skb_cow_head(skb, dev->needed_headroom - 260 (tunnel->hlen + sizeof(struct iphdr)))) 261 goto free_skb; 262 263 tnl_params = (const struct iphdr *)skb->data; 264 265 /* Pull skb since ip_tunnel_xmit() needs skb->data pointing 266 * to gre header. 267 */ 268 skb_pull(skb, tunnel->hlen + sizeof(struct iphdr)); 269 } else { 270 if (skb_cow_head(skb, dev->needed_headroom)) 271 goto free_skb; 272 273 tnl_params = &tunnel->parms.iph; 274 } 275 276 __gre_xmit(skb, dev, tnl_params, skb->protocol); 277 278 return NETDEV_TX_OK; 279 280 free_skb: 281 kfree_skb(skb); 282 out: 283 dev->stats.tx_dropped++; 284 return NETDEV_TX_OK; 285 } 286 287 static netdev_tx_t gre_tap_xmit(struct sk_buff *skb, 288 struct net_device *dev) 289 { 290 struct ip_tunnel *tunnel = netdev_priv(dev); 291 292 skb = gre_handle_offloads(skb, !!(tunnel->parms.o_flags&TUNNEL_CSUM)); 293 if (IS_ERR(skb)) 294 goto out; 295 296 if (skb_cow_head(skb, dev->needed_headroom)) 297 goto free_skb; 298 299 __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB)); 300 301 return NETDEV_TX_OK; 302 303 free_skb: 304 kfree_skb(skb); 305 out: 306 dev->stats.tx_dropped++; 307 return NETDEV_TX_OK; 308 } 309 310 static int ipgre_tunnel_ioctl(struct net_device *dev, 311 struct ifreq *ifr, int cmd) 312 { 313 int err = 0; 314 struct ip_tunnel_parm p; 315 316 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 317 return -EFAULT; 318 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) { 319 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE || 320 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) || 321 ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))) 322 return -EINVAL; 323 } 324 p.i_flags = gre_flags_to_tnl_flags(p.i_flags); 325 p.o_flags = gre_flags_to_tnl_flags(p.o_flags); 326 327 err = ip_tunnel_ioctl(dev, &p, cmd); 328 if (err) 329 return err; 330 331 p.i_flags = tnl_flags_to_gre_flags(p.i_flags); 332 p.o_flags = tnl_flags_to_gre_flags(p.o_flags); 333 334 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 335 return -EFAULT; 336 return 0; 337 } 338 339 /* Nice toy. Unfortunately, useless in real life :-) 340 It allows to construct virtual multiprotocol broadcast "LAN" 341 over the Internet, provided multicast routing is tuned. 342 343 344 I have no idea was this bicycle invented before me, 345 so that I had to set ARPHRD_IPGRE to a random value. 346 I have an impression, that Cisco could make something similar, 347 but this feature is apparently missing in IOS<=11.2(8). 348 349 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks 350 with broadcast 224.66.66.66. If you have access to mbone, play with me :-) 351 352 ping -t 255 224.66.66.66 353 354 If nobody answers, mbone does not work. 355 356 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255 357 ip addr add 10.66.66.<somewhat>/24 dev Universe 358 ifconfig Universe up 359 ifconfig Universe add fe80::<Your_real_addr>/10 360 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96 361 ftp 10.66.66.66 362 ... 363 ftp fec0:6666:6666::193.233.7.65 364 ... 365 */ 366 static int ipgre_header(struct sk_buff *skb, struct net_device *dev, 367 unsigned short type, 368 const void *daddr, const void *saddr, unsigned int len) 369 { 370 struct ip_tunnel *t = netdev_priv(dev); 371 struct iphdr *iph; 372 struct gre_base_hdr *greh; 373 374 iph = (struct iphdr *)skb_push(skb, t->hlen + sizeof(*iph)); 375 greh = (struct gre_base_hdr *)(iph+1); 376 greh->flags = tnl_flags_to_gre_flags(t->parms.o_flags); 377 greh->protocol = htons(type); 378 379 memcpy(iph, &t->parms.iph, sizeof(struct iphdr)); 380 381 /* Set the source hardware address. */ 382 if (saddr) 383 memcpy(&iph->saddr, saddr, 4); 384 if (daddr) 385 memcpy(&iph->daddr, daddr, 4); 386 if (iph->daddr) 387 return t->hlen + sizeof(*iph); 388 389 return -(t->hlen + sizeof(*iph)); 390 } 391 392 static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr) 393 { 394 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb); 395 memcpy(haddr, &iph->saddr, 4); 396 return 4; 397 } 398 399 static const struct header_ops ipgre_header_ops = { 400 .create = ipgre_header, 401 .parse = ipgre_header_parse, 402 }; 403 404 #ifdef CONFIG_NET_IPGRE_BROADCAST 405 static int ipgre_open(struct net_device *dev) 406 { 407 struct ip_tunnel *t = netdev_priv(dev); 408 409 if (ipv4_is_multicast(t->parms.iph.daddr)) { 410 struct flowi4 fl4; 411 struct rtable *rt; 412 413 rt = ip_route_output_gre(dev_net(dev), &fl4, 414 t->parms.iph.daddr, 415 t->parms.iph.saddr, 416 t->parms.o_key, 417 RT_TOS(t->parms.iph.tos), 418 t->parms.link); 419 if (IS_ERR(rt)) 420 return -EADDRNOTAVAIL; 421 dev = rt->dst.dev; 422 ip_rt_put(rt); 423 if (__in_dev_get_rtnl(dev) == NULL) 424 return -EADDRNOTAVAIL; 425 t->mlink = dev->ifindex; 426 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr); 427 } 428 return 0; 429 } 430 431 static int ipgre_close(struct net_device *dev) 432 { 433 struct ip_tunnel *t = netdev_priv(dev); 434 435 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) { 436 struct in_device *in_dev; 437 in_dev = inetdev_by_index(dev_net(dev), t->mlink); 438 if (in_dev) 439 ip_mc_dec_group(in_dev, t->parms.iph.daddr); 440 } 441 return 0; 442 } 443 #endif 444 445 static const struct net_device_ops ipgre_netdev_ops = { 446 .ndo_init = ipgre_tunnel_init, 447 .ndo_uninit = ip_tunnel_uninit, 448 #ifdef CONFIG_NET_IPGRE_BROADCAST 449 .ndo_open = ipgre_open, 450 .ndo_stop = ipgre_close, 451 #endif 452 .ndo_start_xmit = ipgre_xmit, 453 .ndo_do_ioctl = ipgre_tunnel_ioctl, 454 .ndo_change_mtu = ip_tunnel_change_mtu, 455 .ndo_get_stats64 = ip_tunnel_get_stats64, 456 }; 457 458 #define GRE_FEATURES (NETIF_F_SG | \ 459 NETIF_F_FRAGLIST | \ 460 NETIF_F_HIGHDMA | \ 461 NETIF_F_HW_CSUM) 462 463 static void ipgre_tunnel_setup(struct net_device *dev) 464 { 465 dev->netdev_ops = &ipgre_netdev_ops; 466 dev->type = ARPHRD_IPGRE; 467 ip_tunnel_setup(dev, ipgre_net_id); 468 } 469 470 static void __gre_tunnel_init(struct net_device *dev) 471 { 472 struct ip_tunnel *tunnel; 473 474 tunnel = netdev_priv(dev); 475 tunnel->hlen = ip_gre_calc_hlen(tunnel->parms.o_flags); 476 tunnel->parms.iph.protocol = IPPROTO_GRE; 477 478 dev->needed_headroom = LL_MAX_HEADER + sizeof(struct iphdr) + 4; 479 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr) - 4; 480 481 dev->features |= NETIF_F_NETNS_LOCAL | GRE_FEATURES; 482 dev->hw_features |= GRE_FEATURES; 483 484 if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) { 485 /* TCP offload with GRE SEQ is not supported. */ 486 dev->features |= NETIF_F_GSO_SOFTWARE; 487 dev->hw_features |= NETIF_F_GSO_SOFTWARE; 488 /* Can use a lockless transmit, unless we generate 489 * output sequences 490 */ 491 dev->features |= NETIF_F_LLTX; 492 } 493 } 494 495 static int ipgre_tunnel_init(struct net_device *dev) 496 { 497 struct ip_tunnel *tunnel = netdev_priv(dev); 498 struct iphdr *iph = &tunnel->parms.iph; 499 500 __gre_tunnel_init(dev); 501 502 memcpy(dev->dev_addr, &iph->saddr, 4); 503 memcpy(dev->broadcast, &iph->daddr, 4); 504 505 dev->flags = IFF_NOARP; 506 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; 507 dev->addr_len = 4; 508 509 if (iph->daddr) { 510 #ifdef CONFIG_NET_IPGRE_BROADCAST 511 if (ipv4_is_multicast(iph->daddr)) { 512 if (!iph->saddr) 513 return -EINVAL; 514 dev->flags = IFF_BROADCAST; 515 dev->header_ops = &ipgre_header_ops; 516 } 517 #endif 518 } else 519 dev->header_ops = &ipgre_header_ops; 520 521 return ip_tunnel_init(dev); 522 } 523 524 static struct gre_cisco_protocol ipgre_protocol = { 525 .handler = ipgre_rcv, 526 .err_handler = ipgre_err, 527 .priority = 0, 528 }; 529 530 static int __net_init ipgre_init_net(struct net *net) 531 { 532 return ip_tunnel_init_net(net, ipgre_net_id, &ipgre_link_ops, NULL); 533 } 534 535 static void __net_exit ipgre_exit_net(struct net *net) 536 { 537 struct ip_tunnel_net *itn = net_generic(net, ipgre_net_id); 538 ip_tunnel_delete_net(itn, &ipgre_link_ops); 539 } 540 541 static struct pernet_operations ipgre_net_ops = { 542 .init = ipgre_init_net, 543 .exit = ipgre_exit_net, 544 .id = &ipgre_net_id, 545 .size = sizeof(struct ip_tunnel_net), 546 }; 547 548 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[]) 549 { 550 __be16 flags; 551 552 if (!data) 553 return 0; 554 555 flags = 0; 556 if (data[IFLA_GRE_IFLAGS]) 557 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); 558 if (data[IFLA_GRE_OFLAGS]) 559 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); 560 if (flags & (GRE_VERSION|GRE_ROUTING)) 561 return -EINVAL; 562 563 return 0; 564 } 565 566 static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[]) 567 { 568 __be32 daddr; 569 570 if (tb[IFLA_ADDRESS]) { 571 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) 572 return -EINVAL; 573 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) 574 return -EADDRNOTAVAIL; 575 } 576 577 if (!data) 578 goto out; 579 580 if (data[IFLA_GRE_REMOTE]) { 581 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4); 582 if (!daddr) 583 return -EINVAL; 584 } 585 586 out: 587 return ipgre_tunnel_validate(tb, data); 588 } 589 590 static void ipgre_netlink_parms(struct nlattr *data[], struct nlattr *tb[], 591 struct ip_tunnel_parm *parms) 592 { 593 memset(parms, 0, sizeof(*parms)); 594 595 parms->iph.protocol = IPPROTO_GRE; 596 597 if (!data) 598 return; 599 600 if (data[IFLA_GRE_LINK]) 601 parms->link = nla_get_u32(data[IFLA_GRE_LINK]); 602 603 if (data[IFLA_GRE_IFLAGS]) 604 parms->i_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_IFLAGS])); 605 606 if (data[IFLA_GRE_OFLAGS]) 607 parms->o_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_OFLAGS])); 608 609 if (data[IFLA_GRE_IKEY]) 610 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]); 611 612 if (data[IFLA_GRE_OKEY]) 613 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]); 614 615 if (data[IFLA_GRE_LOCAL]) 616 parms->iph.saddr = nla_get_be32(data[IFLA_GRE_LOCAL]); 617 618 if (data[IFLA_GRE_REMOTE]) 619 parms->iph.daddr = nla_get_be32(data[IFLA_GRE_REMOTE]); 620 621 if (data[IFLA_GRE_TTL]) 622 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]); 623 624 if (data[IFLA_GRE_TOS]) 625 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]); 626 627 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC])) 628 parms->iph.frag_off = htons(IP_DF); 629 } 630 631 static int gre_tap_init(struct net_device *dev) 632 { 633 __gre_tunnel_init(dev); 634 635 return ip_tunnel_init(dev); 636 } 637 638 static const struct net_device_ops gre_tap_netdev_ops = { 639 .ndo_init = gre_tap_init, 640 .ndo_uninit = ip_tunnel_uninit, 641 .ndo_start_xmit = gre_tap_xmit, 642 .ndo_set_mac_address = eth_mac_addr, 643 .ndo_validate_addr = eth_validate_addr, 644 .ndo_change_mtu = ip_tunnel_change_mtu, 645 .ndo_get_stats64 = ip_tunnel_get_stats64, 646 }; 647 648 static void ipgre_tap_setup(struct net_device *dev) 649 { 650 ether_setup(dev); 651 dev->netdev_ops = &gre_tap_netdev_ops; 652 ip_tunnel_setup(dev, gre_tap_net_id); 653 } 654 655 static int ipgre_newlink(struct net *src_net, struct net_device *dev, 656 struct nlattr *tb[], struct nlattr *data[]) 657 { 658 struct ip_tunnel_parm p; 659 660 ipgre_netlink_parms(data, tb, &p); 661 return ip_tunnel_newlink(dev, tb, &p); 662 } 663 664 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[], 665 struct nlattr *data[]) 666 { 667 struct ip_tunnel_parm p; 668 669 ipgre_netlink_parms(data, tb, &p); 670 return ip_tunnel_changelink(dev, tb, &p); 671 } 672 673 static size_t ipgre_get_size(const struct net_device *dev) 674 { 675 return 676 /* IFLA_GRE_LINK */ 677 nla_total_size(4) + 678 /* IFLA_GRE_IFLAGS */ 679 nla_total_size(2) + 680 /* IFLA_GRE_OFLAGS */ 681 nla_total_size(2) + 682 /* IFLA_GRE_IKEY */ 683 nla_total_size(4) + 684 /* IFLA_GRE_OKEY */ 685 nla_total_size(4) + 686 /* IFLA_GRE_LOCAL */ 687 nla_total_size(4) + 688 /* IFLA_GRE_REMOTE */ 689 nla_total_size(4) + 690 /* IFLA_GRE_TTL */ 691 nla_total_size(1) + 692 /* IFLA_GRE_TOS */ 693 nla_total_size(1) + 694 /* IFLA_GRE_PMTUDISC */ 695 nla_total_size(1) + 696 0; 697 } 698 699 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev) 700 { 701 struct ip_tunnel *t = netdev_priv(dev); 702 struct ip_tunnel_parm *p = &t->parms; 703 704 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) || 705 nla_put_be16(skb, IFLA_GRE_IFLAGS, tnl_flags_to_gre_flags(p->i_flags)) || 706 nla_put_be16(skb, IFLA_GRE_OFLAGS, tnl_flags_to_gre_flags(p->o_flags)) || 707 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) || 708 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) || 709 nla_put_be32(skb, IFLA_GRE_LOCAL, p->iph.saddr) || 710 nla_put_be32(skb, IFLA_GRE_REMOTE, p->iph.daddr) || 711 nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) || 712 nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) || 713 nla_put_u8(skb, IFLA_GRE_PMTUDISC, 714 !!(p->iph.frag_off & htons(IP_DF)))) 715 goto nla_put_failure; 716 return 0; 717 718 nla_put_failure: 719 return -EMSGSIZE; 720 } 721 722 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = { 723 [IFLA_GRE_LINK] = { .type = NLA_U32 }, 724 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 }, 725 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 }, 726 [IFLA_GRE_IKEY] = { .type = NLA_U32 }, 727 [IFLA_GRE_OKEY] = { .type = NLA_U32 }, 728 [IFLA_GRE_LOCAL] = { .len = FIELD_SIZEOF(struct iphdr, saddr) }, 729 [IFLA_GRE_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) }, 730 [IFLA_GRE_TTL] = { .type = NLA_U8 }, 731 [IFLA_GRE_TOS] = { .type = NLA_U8 }, 732 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 }, 733 }; 734 735 static struct rtnl_link_ops ipgre_link_ops __read_mostly = { 736 .kind = "gre", 737 .maxtype = IFLA_GRE_MAX, 738 .policy = ipgre_policy, 739 .priv_size = sizeof(struct ip_tunnel), 740 .setup = ipgre_tunnel_setup, 741 .validate = ipgre_tunnel_validate, 742 .newlink = ipgre_newlink, 743 .changelink = ipgre_changelink, 744 .dellink = ip_tunnel_dellink, 745 .get_size = ipgre_get_size, 746 .fill_info = ipgre_fill_info, 747 }; 748 749 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = { 750 .kind = "gretap", 751 .maxtype = IFLA_GRE_MAX, 752 .policy = ipgre_policy, 753 .priv_size = sizeof(struct ip_tunnel), 754 .setup = ipgre_tap_setup, 755 .validate = ipgre_tap_validate, 756 .newlink = ipgre_newlink, 757 .changelink = ipgre_changelink, 758 .dellink = ip_tunnel_dellink, 759 .get_size = ipgre_get_size, 760 .fill_info = ipgre_fill_info, 761 }; 762 763 static int __net_init ipgre_tap_init_net(struct net *net) 764 { 765 return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, NULL); 766 } 767 768 static void __net_exit ipgre_tap_exit_net(struct net *net) 769 { 770 struct ip_tunnel_net *itn = net_generic(net, gre_tap_net_id); 771 ip_tunnel_delete_net(itn, &ipgre_tap_ops); 772 } 773 774 static struct pernet_operations ipgre_tap_net_ops = { 775 .init = ipgre_tap_init_net, 776 .exit = ipgre_tap_exit_net, 777 .id = &gre_tap_net_id, 778 .size = sizeof(struct ip_tunnel_net), 779 }; 780 781 static int __init ipgre_init(void) 782 { 783 int err; 784 785 pr_info("GRE over IPv4 tunneling driver\n"); 786 787 err = register_pernet_device(&ipgre_net_ops); 788 if (err < 0) 789 return err; 790 791 err = register_pernet_device(&ipgre_tap_net_ops); 792 if (err < 0) 793 goto pnet_tap_faied; 794 795 err = gre_cisco_register(&ipgre_protocol); 796 if (err < 0) { 797 pr_info("%s: can't add protocol\n", __func__); 798 goto add_proto_failed; 799 } 800 801 err = rtnl_link_register(&ipgre_link_ops); 802 if (err < 0) 803 goto rtnl_link_failed; 804 805 err = rtnl_link_register(&ipgre_tap_ops); 806 if (err < 0) 807 goto tap_ops_failed; 808 809 return 0; 810 811 tap_ops_failed: 812 rtnl_link_unregister(&ipgre_link_ops); 813 rtnl_link_failed: 814 gre_cisco_unregister(&ipgre_protocol); 815 add_proto_failed: 816 unregister_pernet_device(&ipgre_tap_net_ops); 817 pnet_tap_faied: 818 unregister_pernet_device(&ipgre_net_ops); 819 return err; 820 } 821 822 static void __exit ipgre_fini(void) 823 { 824 rtnl_link_unregister(&ipgre_tap_ops); 825 rtnl_link_unregister(&ipgre_link_ops); 826 gre_cisco_unregister(&ipgre_protocol); 827 unregister_pernet_device(&ipgre_tap_net_ops); 828 unregister_pernet_device(&ipgre_net_ops); 829 } 830 831 module_init(ipgre_init); 832 module_exit(ipgre_fini); 833 MODULE_LICENSE("GPL"); 834 MODULE_ALIAS_RTNL_LINK("gre"); 835 MODULE_ALIAS_RTNL_LINK("gretap"); 836 MODULE_ALIAS_NETDEV("gre0"); 837 MODULE_ALIAS_NETDEV("gretap0"); 838