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->tun_hlen); 243 244 skb_set_inner_protocol(skb, tpi.proto); 245 246 ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol); 247 } 248 249 static netdev_tx_t ipgre_xmit(struct sk_buff *skb, 250 struct net_device *dev) 251 { 252 struct ip_tunnel *tunnel = netdev_priv(dev); 253 const struct iphdr *tnl_params; 254 255 if (dev->header_ops) { 256 /* Need space for new headers */ 257 if (skb_cow_head(skb, dev->needed_headroom - 258 (tunnel->hlen + sizeof(struct iphdr)))) 259 goto free_skb; 260 261 tnl_params = (const struct iphdr *)skb->data; 262 263 /* Pull skb since ip_tunnel_xmit() needs skb->data pointing 264 * to gre header. 265 */ 266 skb_pull(skb, tunnel->hlen + sizeof(struct iphdr)); 267 skb_reset_mac_header(skb); 268 } else { 269 if (skb_cow_head(skb, dev->needed_headroom)) 270 goto free_skb; 271 272 tnl_params = &tunnel->parms.iph; 273 } 274 275 skb = gre_handle_offloads(skb, !!(tunnel->parms.o_flags&TUNNEL_CSUM)); 276 if (IS_ERR(skb)) 277 goto out; 278 279 __gre_xmit(skb, dev, tnl_params, skb->protocol); 280 281 return NETDEV_TX_OK; 282 283 free_skb: 284 kfree_skb(skb); 285 out: 286 dev->stats.tx_dropped++; 287 return NETDEV_TX_OK; 288 } 289 290 static netdev_tx_t gre_tap_xmit(struct sk_buff *skb, 291 struct net_device *dev) 292 { 293 struct ip_tunnel *tunnel = netdev_priv(dev); 294 295 skb = gre_handle_offloads(skb, !!(tunnel->parms.o_flags&TUNNEL_CSUM)); 296 if (IS_ERR(skb)) 297 goto out; 298 299 if (skb_cow_head(skb, dev->needed_headroom)) 300 goto free_skb; 301 302 __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB)); 303 304 return NETDEV_TX_OK; 305 306 free_skb: 307 kfree_skb(skb); 308 out: 309 dev->stats.tx_dropped++; 310 return NETDEV_TX_OK; 311 } 312 313 static int ipgre_tunnel_ioctl(struct net_device *dev, 314 struct ifreq *ifr, int cmd) 315 { 316 int err; 317 struct ip_tunnel_parm p; 318 319 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 320 return -EFAULT; 321 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) { 322 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE || 323 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) || 324 ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))) 325 return -EINVAL; 326 } 327 p.i_flags = gre_flags_to_tnl_flags(p.i_flags); 328 p.o_flags = gre_flags_to_tnl_flags(p.o_flags); 329 330 err = ip_tunnel_ioctl(dev, &p, cmd); 331 if (err) 332 return err; 333 334 p.i_flags = tnl_flags_to_gre_flags(p.i_flags); 335 p.o_flags = tnl_flags_to_gre_flags(p.o_flags); 336 337 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 338 return -EFAULT; 339 return 0; 340 } 341 342 /* Nice toy. Unfortunately, useless in real life :-) 343 It allows to construct virtual multiprotocol broadcast "LAN" 344 over the Internet, provided multicast routing is tuned. 345 346 347 I have no idea was this bicycle invented before me, 348 so that I had to set ARPHRD_IPGRE to a random value. 349 I have an impression, that Cisco could make something similar, 350 but this feature is apparently missing in IOS<=11.2(8). 351 352 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks 353 with broadcast 224.66.66.66. If you have access to mbone, play with me :-) 354 355 ping -t 255 224.66.66.66 356 357 If nobody answers, mbone does not work. 358 359 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255 360 ip addr add 10.66.66.<somewhat>/24 dev Universe 361 ifconfig Universe up 362 ifconfig Universe add fe80::<Your_real_addr>/10 363 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96 364 ftp 10.66.66.66 365 ... 366 ftp fec0:6666:6666::193.233.7.65 367 ... 368 */ 369 static int ipgre_header(struct sk_buff *skb, struct net_device *dev, 370 unsigned short type, 371 const void *daddr, const void *saddr, unsigned int len) 372 { 373 struct ip_tunnel *t = netdev_priv(dev); 374 struct iphdr *iph; 375 struct gre_base_hdr *greh; 376 377 iph = (struct iphdr *)skb_push(skb, t->hlen + sizeof(*iph)); 378 greh = (struct gre_base_hdr *)(iph+1); 379 greh->flags = tnl_flags_to_gre_flags(t->parms.o_flags); 380 greh->protocol = htons(type); 381 382 memcpy(iph, &t->parms.iph, sizeof(struct iphdr)); 383 384 /* Set the source hardware address. */ 385 if (saddr) 386 memcpy(&iph->saddr, saddr, 4); 387 if (daddr) 388 memcpy(&iph->daddr, daddr, 4); 389 if (iph->daddr) 390 return t->hlen + sizeof(*iph); 391 392 return -(t->hlen + sizeof(*iph)); 393 } 394 395 static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr) 396 { 397 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb); 398 memcpy(haddr, &iph->saddr, 4); 399 return 4; 400 } 401 402 static const struct header_ops ipgre_header_ops = { 403 .create = ipgre_header, 404 .parse = ipgre_header_parse, 405 }; 406 407 #ifdef CONFIG_NET_IPGRE_BROADCAST 408 static int ipgre_open(struct net_device *dev) 409 { 410 struct ip_tunnel *t = netdev_priv(dev); 411 412 if (ipv4_is_multicast(t->parms.iph.daddr)) { 413 struct flowi4 fl4; 414 struct rtable *rt; 415 416 rt = ip_route_output_gre(t->net, &fl4, 417 t->parms.iph.daddr, 418 t->parms.iph.saddr, 419 t->parms.o_key, 420 RT_TOS(t->parms.iph.tos), 421 t->parms.link); 422 if (IS_ERR(rt)) 423 return -EADDRNOTAVAIL; 424 dev = rt->dst.dev; 425 ip_rt_put(rt); 426 if (__in_dev_get_rtnl(dev) == NULL) 427 return -EADDRNOTAVAIL; 428 t->mlink = dev->ifindex; 429 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr); 430 } 431 return 0; 432 } 433 434 static int ipgre_close(struct net_device *dev) 435 { 436 struct ip_tunnel *t = netdev_priv(dev); 437 438 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) { 439 struct in_device *in_dev; 440 in_dev = inetdev_by_index(t->net, t->mlink); 441 if (in_dev) 442 ip_mc_dec_group(in_dev, t->parms.iph.daddr); 443 } 444 return 0; 445 } 446 #endif 447 448 static const struct net_device_ops ipgre_netdev_ops = { 449 .ndo_init = ipgre_tunnel_init, 450 .ndo_uninit = ip_tunnel_uninit, 451 #ifdef CONFIG_NET_IPGRE_BROADCAST 452 .ndo_open = ipgre_open, 453 .ndo_stop = ipgre_close, 454 #endif 455 .ndo_start_xmit = ipgre_xmit, 456 .ndo_do_ioctl = ipgre_tunnel_ioctl, 457 .ndo_change_mtu = ip_tunnel_change_mtu, 458 .ndo_get_stats64 = ip_tunnel_get_stats64, 459 }; 460 461 #define GRE_FEATURES (NETIF_F_SG | \ 462 NETIF_F_FRAGLIST | \ 463 NETIF_F_HIGHDMA | \ 464 NETIF_F_HW_CSUM) 465 466 static void ipgre_tunnel_setup(struct net_device *dev) 467 { 468 dev->netdev_ops = &ipgre_netdev_ops; 469 dev->type = ARPHRD_IPGRE; 470 ip_tunnel_setup(dev, ipgre_net_id); 471 } 472 473 static void __gre_tunnel_init(struct net_device *dev) 474 { 475 struct ip_tunnel *tunnel; 476 int t_hlen; 477 478 tunnel = netdev_priv(dev); 479 tunnel->tun_hlen = ip_gre_calc_hlen(tunnel->parms.o_flags); 480 tunnel->parms.iph.protocol = IPPROTO_GRE; 481 482 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen; 483 484 t_hlen = tunnel->hlen + sizeof(struct iphdr); 485 486 dev->needed_headroom = LL_MAX_HEADER + t_hlen + 4; 487 dev->mtu = ETH_DATA_LEN - t_hlen - 4; 488 489 dev->features |= GRE_FEATURES; 490 dev->hw_features |= GRE_FEATURES; 491 492 if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) { 493 /* TCP offload with GRE SEQ is not supported. */ 494 dev->features |= NETIF_F_GSO_SOFTWARE; 495 dev->hw_features |= NETIF_F_GSO_SOFTWARE; 496 /* Can use a lockless transmit, unless we generate 497 * output sequences 498 */ 499 dev->features |= NETIF_F_LLTX; 500 } 501 } 502 503 static int ipgre_tunnel_init(struct net_device *dev) 504 { 505 struct ip_tunnel *tunnel = netdev_priv(dev); 506 struct iphdr *iph = &tunnel->parms.iph; 507 508 __gre_tunnel_init(dev); 509 510 memcpy(dev->dev_addr, &iph->saddr, 4); 511 memcpy(dev->broadcast, &iph->daddr, 4); 512 513 dev->flags = IFF_NOARP; 514 netif_keep_dst(dev); 515 dev->addr_len = 4; 516 517 if (iph->daddr) { 518 #ifdef CONFIG_NET_IPGRE_BROADCAST 519 if (ipv4_is_multicast(iph->daddr)) { 520 if (!iph->saddr) 521 return -EINVAL; 522 dev->flags = IFF_BROADCAST; 523 dev->header_ops = &ipgre_header_ops; 524 } 525 #endif 526 } else 527 dev->header_ops = &ipgre_header_ops; 528 529 return ip_tunnel_init(dev); 530 } 531 532 static struct gre_cisco_protocol ipgre_protocol = { 533 .handler = ipgre_rcv, 534 .err_handler = ipgre_err, 535 .priority = 0, 536 }; 537 538 static int __net_init ipgre_init_net(struct net *net) 539 { 540 return ip_tunnel_init_net(net, ipgre_net_id, &ipgre_link_ops, NULL); 541 } 542 543 static void __net_exit ipgre_exit_net(struct net *net) 544 { 545 struct ip_tunnel_net *itn = net_generic(net, ipgre_net_id); 546 ip_tunnel_delete_net(itn, &ipgre_link_ops); 547 } 548 549 static struct pernet_operations ipgre_net_ops = { 550 .init = ipgre_init_net, 551 .exit = ipgre_exit_net, 552 .id = &ipgre_net_id, 553 .size = sizeof(struct ip_tunnel_net), 554 }; 555 556 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[]) 557 { 558 __be16 flags; 559 560 if (!data) 561 return 0; 562 563 flags = 0; 564 if (data[IFLA_GRE_IFLAGS]) 565 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); 566 if (data[IFLA_GRE_OFLAGS]) 567 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); 568 if (flags & (GRE_VERSION|GRE_ROUTING)) 569 return -EINVAL; 570 571 return 0; 572 } 573 574 static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[]) 575 { 576 __be32 daddr; 577 578 if (tb[IFLA_ADDRESS]) { 579 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) 580 return -EINVAL; 581 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) 582 return -EADDRNOTAVAIL; 583 } 584 585 if (!data) 586 goto out; 587 588 if (data[IFLA_GRE_REMOTE]) { 589 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4); 590 if (!daddr) 591 return -EINVAL; 592 } 593 594 out: 595 return ipgre_tunnel_validate(tb, data); 596 } 597 598 static void ipgre_netlink_parms(struct nlattr *data[], struct nlattr *tb[], 599 struct ip_tunnel_parm *parms) 600 { 601 memset(parms, 0, sizeof(*parms)); 602 603 parms->iph.protocol = IPPROTO_GRE; 604 605 if (!data) 606 return; 607 608 if (data[IFLA_GRE_LINK]) 609 parms->link = nla_get_u32(data[IFLA_GRE_LINK]); 610 611 if (data[IFLA_GRE_IFLAGS]) 612 parms->i_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_IFLAGS])); 613 614 if (data[IFLA_GRE_OFLAGS]) 615 parms->o_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_OFLAGS])); 616 617 if (data[IFLA_GRE_IKEY]) 618 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]); 619 620 if (data[IFLA_GRE_OKEY]) 621 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]); 622 623 if (data[IFLA_GRE_LOCAL]) 624 parms->iph.saddr = nla_get_be32(data[IFLA_GRE_LOCAL]); 625 626 if (data[IFLA_GRE_REMOTE]) 627 parms->iph.daddr = nla_get_be32(data[IFLA_GRE_REMOTE]); 628 629 if (data[IFLA_GRE_TTL]) 630 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]); 631 632 if (data[IFLA_GRE_TOS]) 633 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]); 634 635 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC])) 636 parms->iph.frag_off = htons(IP_DF); 637 } 638 639 /* This function returns true when ENCAP attributes are present in the nl msg */ 640 static bool ipgre_netlink_encap_parms(struct nlattr *data[], 641 struct ip_tunnel_encap *ipencap) 642 { 643 bool ret = false; 644 645 memset(ipencap, 0, sizeof(*ipencap)); 646 647 if (!data) 648 return ret; 649 650 if (data[IFLA_GRE_ENCAP_TYPE]) { 651 ret = true; 652 ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]); 653 } 654 655 if (data[IFLA_GRE_ENCAP_FLAGS]) { 656 ret = true; 657 ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]); 658 } 659 660 if (data[IFLA_GRE_ENCAP_SPORT]) { 661 ret = true; 662 ipencap->sport = nla_get_u16(data[IFLA_GRE_ENCAP_SPORT]); 663 } 664 665 if (data[IFLA_GRE_ENCAP_DPORT]) { 666 ret = true; 667 ipencap->dport = nla_get_u16(data[IFLA_GRE_ENCAP_DPORT]); 668 } 669 670 return ret; 671 } 672 673 static int gre_tap_init(struct net_device *dev) 674 { 675 __gre_tunnel_init(dev); 676 677 return ip_tunnel_init(dev); 678 } 679 680 static const struct net_device_ops gre_tap_netdev_ops = { 681 .ndo_init = gre_tap_init, 682 .ndo_uninit = ip_tunnel_uninit, 683 .ndo_start_xmit = gre_tap_xmit, 684 .ndo_set_mac_address = eth_mac_addr, 685 .ndo_validate_addr = eth_validate_addr, 686 .ndo_change_mtu = ip_tunnel_change_mtu, 687 .ndo_get_stats64 = ip_tunnel_get_stats64, 688 }; 689 690 static void ipgre_tap_setup(struct net_device *dev) 691 { 692 ether_setup(dev); 693 dev->netdev_ops = &gre_tap_netdev_ops; 694 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 695 ip_tunnel_setup(dev, gre_tap_net_id); 696 } 697 698 static int ipgre_newlink(struct net *src_net, struct net_device *dev, 699 struct nlattr *tb[], struct nlattr *data[]) 700 { 701 struct ip_tunnel_parm p; 702 struct ip_tunnel_encap ipencap; 703 704 if (ipgre_netlink_encap_parms(data, &ipencap)) { 705 struct ip_tunnel *t = netdev_priv(dev); 706 int err = ip_tunnel_encap_setup(t, &ipencap); 707 708 if (err < 0) 709 return err; 710 } 711 712 ipgre_netlink_parms(data, tb, &p); 713 return ip_tunnel_newlink(dev, tb, &p); 714 } 715 716 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[], 717 struct nlattr *data[]) 718 { 719 struct ip_tunnel_parm p; 720 struct ip_tunnel_encap ipencap; 721 722 if (ipgre_netlink_encap_parms(data, &ipencap)) { 723 struct ip_tunnel *t = netdev_priv(dev); 724 int err = ip_tunnel_encap_setup(t, &ipencap); 725 726 if (err < 0) 727 return err; 728 } 729 730 ipgre_netlink_parms(data, tb, &p); 731 return ip_tunnel_changelink(dev, tb, &p); 732 } 733 734 static size_t ipgre_get_size(const struct net_device *dev) 735 { 736 return 737 /* IFLA_GRE_LINK */ 738 nla_total_size(4) + 739 /* IFLA_GRE_IFLAGS */ 740 nla_total_size(2) + 741 /* IFLA_GRE_OFLAGS */ 742 nla_total_size(2) + 743 /* IFLA_GRE_IKEY */ 744 nla_total_size(4) + 745 /* IFLA_GRE_OKEY */ 746 nla_total_size(4) + 747 /* IFLA_GRE_LOCAL */ 748 nla_total_size(4) + 749 /* IFLA_GRE_REMOTE */ 750 nla_total_size(4) + 751 /* IFLA_GRE_TTL */ 752 nla_total_size(1) + 753 /* IFLA_GRE_TOS */ 754 nla_total_size(1) + 755 /* IFLA_GRE_PMTUDISC */ 756 nla_total_size(1) + 757 /* IFLA_GRE_ENCAP_TYPE */ 758 nla_total_size(2) + 759 /* IFLA_GRE_ENCAP_FLAGS */ 760 nla_total_size(2) + 761 /* IFLA_GRE_ENCAP_SPORT */ 762 nla_total_size(2) + 763 /* IFLA_GRE_ENCAP_DPORT */ 764 nla_total_size(2) + 765 0; 766 } 767 768 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev) 769 { 770 struct ip_tunnel *t = netdev_priv(dev); 771 struct ip_tunnel_parm *p = &t->parms; 772 773 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) || 774 nla_put_be16(skb, IFLA_GRE_IFLAGS, tnl_flags_to_gre_flags(p->i_flags)) || 775 nla_put_be16(skb, IFLA_GRE_OFLAGS, tnl_flags_to_gre_flags(p->o_flags)) || 776 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) || 777 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) || 778 nla_put_be32(skb, IFLA_GRE_LOCAL, p->iph.saddr) || 779 nla_put_be32(skb, IFLA_GRE_REMOTE, p->iph.daddr) || 780 nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) || 781 nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) || 782 nla_put_u8(skb, IFLA_GRE_PMTUDISC, 783 !!(p->iph.frag_off & htons(IP_DF)))) 784 goto nla_put_failure; 785 786 if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE, 787 t->encap.type) || 788 nla_put_u16(skb, IFLA_GRE_ENCAP_SPORT, 789 t->encap.sport) || 790 nla_put_u16(skb, IFLA_GRE_ENCAP_DPORT, 791 t->encap.dport) || 792 nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS, 793 t->encap.flags)) 794 goto nla_put_failure; 795 796 return 0; 797 798 nla_put_failure: 799 return -EMSGSIZE; 800 } 801 802 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = { 803 [IFLA_GRE_LINK] = { .type = NLA_U32 }, 804 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 }, 805 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 }, 806 [IFLA_GRE_IKEY] = { .type = NLA_U32 }, 807 [IFLA_GRE_OKEY] = { .type = NLA_U32 }, 808 [IFLA_GRE_LOCAL] = { .len = FIELD_SIZEOF(struct iphdr, saddr) }, 809 [IFLA_GRE_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) }, 810 [IFLA_GRE_TTL] = { .type = NLA_U8 }, 811 [IFLA_GRE_TOS] = { .type = NLA_U8 }, 812 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 }, 813 [IFLA_GRE_ENCAP_TYPE] = { .type = NLA_U16 }, 814 [IFLA_GRE_ENCAP_FLAGS] = { .type = NLA_U16 }, 815 [IFLA_GRE_ENCAP_SPORT] = { .type = NLA_U16 }, 816 [IFLA_GRE_ENCAP_DPORT] = { .type = NLA_U16 }, 817 }; 818 819 static struct rtnl_link_ops ipgre_link_ops __read_mostly = { 820 .kind = "gre", 821 .maxtype = IFLA_GRE_MAX, 822 .policy = ipgre_policy, 823 .priv_size = sizeof(struct ip_tunnel), 824 .setup = ipgre_tunnel_setup, 825 .validate = ipgre_tunnel_validate, 826 .newlink = ipgre_newlink, 827 .changelink = ipgre_changelink, 828 .dellink = ip_tunnel_dellink, 829 .get_size = ipgre_get_size, 830 .fill_info = ipgre_fill_info, 831 }; 832 833 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = { 834 .kind = "gretap", 835 .maxtype = IFLA_GRE_MAX, 836 .policy = ipgre_policy, 837 .priv_size = sizeof(struct ip_tunnel), 838 .setup = ipgre_tap_setup, 839 .validate = ipgre_tap_validate, 840 .newlink = ipgre_newlink, 841 .changelink = ipgre_changelink, 842 .dellink = ip_tunnel_dellink, 843 .get_size = ipgre_get_size, 844 .fill_info = ipgre_fill_info, 845 }; 846 847 static int __net_init ipgre_tap_init_net(struct net *net) 848 { 849 return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, NULL); 850 } 851 852 static void __net_exit ipgre_tap_exit_net(struct net *net) 853 { 854 struct ip_tunnel_net *itn = net_generic(net, gre_tap_net_id); 855 ip_tunnel_delete_net(itn, &ipgre_tap_ops); 856 } 857 858 static struct pernet_operations ipgre_tap_net_ops = { 859 .init = ipgre_tap_init_net, 860 .exit = ipgre_tap_exit_net, 861 .id = &gre_tap_net_id, 862 .size = sizeof(struct ip_tunnel_net), 863 }; 864 865 static int __init ipgre_init(void) 866 { 867 int err; 868 869 pr_info("GRE over IPv4 tunneling driver\n"); 870 871 err = register_pernet_device(&ipgre_net_ops); 872 if (err < 0) 873 return err; 874 875 err = register_pernet_device(&ipgre_tap_net_ops); 876 if (err < 0) 877 goto pnet_tap_faied; 878 879 err = gre_cisco_register(&ipgre_protocol); 880 if (err < 0) { 881 pr_info("%s: can't add protocol\n", __func__); 882 goto add_proto_failed; 883 } 884 885 err = rtnl_link_register(&ipgre_link_ops); 886 if (err < 0) 887 goto rtnl_link_failed; 888 889 err = rtnl_link_register(&ipgre_tap_ops); 890 if (err < 0) 891 goto tap_ops_failed; 892 893 return 0; 894 895 tap_ops_failed: 896 rtnl_link_unregister(&ipgre_link_ops); 897 rtnl_link_failed: 898 gre_cisco_unregister(&ipgre_protocol); 899 add_proto_failed: 900 unregister_pernet_device(&ipgre_tap_net_ops); 901 pnet_tap_faied: 902 unregister_pernet_device(&ipgre_net_ops); 903 return err; 904 } 905 906 static void __exit ipgre_fini(void) 907 { 908 rtnl_link_unregister(&ipgre_tap_ops); 909 rtnl_link_unregister(&ipgre_link_ops); 910 gre_cisco_unregister(&ipgre_protocol); 911 unregister_pernet_device(&ipgre_tap_net_ops); 912 unregister_pernet_device(&ipgre_net_ops); 913 } 914 915 module_init(ipgre_init); 916 module_exit(ipgre_fini); 917 MODULE_LICENSE("GPL"); 918 MODULE_ALIAS_RTNL_LINK("gre"); 919 MODULE_ALIAS_RTNL_LINK("gretap"); 920 MODULE_ALIAS_NETDEV("gre0"); 921 MODULE_ALIAS_NETDEV("gretap0"); 922