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ip_gre.c
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linux-6.19.14/net/ipv4/ip_gre.c
1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * Linux NET3: GRE over IP protocol decoder. 4 * 5 * Authors: Alexey Kuznetsov (kuznet@ms2.inr.ac.ru) 6 */ 7 8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 9 10#include <linux/capability.h> 11#include <linux/module.h> 12#include <linux/types.h> 13#include <linux/kernel.h> 14#include <linux/slab.h> 15#include <linux/uaccess.h> 16#include <linux/skbuff.h> 17#include <linux/netdevice.h> 18#include <linux/in.h> 19#include <linux/tcp.h> 20#include <linux/udp.h> 21#include <linux/if_arp.h> 22#include <linux/if_vlan.h> 23#include <linux/init.h> 24#include <linux/in6.h> 25#include <linux/inetdevice.h> 26#include <linux/igmp.h> 27#include <linux/netfilter_ipv4.h> 28#include <linux/etherdevice.h> 29#include <linux/if_ether.h> 30 31#include <net/flow.h> 32#include <net/sock.h> 33#include <net/ip.h> 34#include <net/icmp.h> 35#include <net/protocol.h> 36#include <net/ip_tunnels.h> 37#include <net/arp.h> 38#include <net/checksum.h> 39#include <net/dsfield.h> 40#include <net/inet_ecn.h> 41#include <net/xfrm.h> 42#include <net/net_namespace.h> 43#include <net/netns/generic.h> 44#include <net/rtnetlink.h> 45#include <net/gre.h> 46#include <net/dst_metadata.h> 47#include <net/erspan.h> 48 49/* 50 Problems & solutions 51 -------------------- 52 53 1. The most important issue is detecting local dead loops. 54 They would cause complete host lockup in transmit, which 55 would be "resolved" by stack overflow or, if queueing is enabled, 56 with infinite looping in net_bh. 57 58 We cannot track such dead loops during route installation, 59 it is infeasible task. The most general solutions would be 60 to keep skb->encapsulation counter (sort of local ttl), 61 and silently drop packet when it expires. It is a good 62 solution, but it supposes maintaining new variable in ALL 63 skb, even if no tunneling is used. 64 65 Current solution: xmit_recursion breaks dead loops. This is a percpu 66 counter, since when we enter the first ndo_xmit(), cpu migration is 67 forbidden. We force an exit if this counter reaches RECURSION_LIMIT 68 69 2. Networking dead loops would not kill routers, but would really 70 kill network. IP hop limit plays role of "t->recursion" in this case, 71 if we copy it from packet being encapsulated to upper header. 72 It is very good solution, but it introduces two problems: 73 74 - Routing protocols, using packets with ttl=1 (OSPF, RIP2), 75 do not work over tunnels. 76 - traceroute does not work. I planned to relay ICMP from tunnel, 77 so that this problem would be solved and traceroute output 78 would even more informative. This idea appeared to be wrong: 79 only Linux complies to rfc1812 now (yes, guys, Linux is the only 80 true router now :-)), all routers (at least, in neighbourhood of mine) 81 return only 8 bytes of payload. It is the end. 82 83 Hence, if we want that OSPF worked or traceroute said something reasonable, 84 we should search for another solution. 85 86 One of them is to parse packet trying to detect inner encapsulation 87 made by our node. It is difficult or even impossible, especially, 88 taking into account fragmentation. TO be short, ttl is not solution at all. 89 90 Current solution: The solution was UNEXPECTEDLY SIMPLE. 91 We force DF flag on tunnels with preconfigured hop limit, 92 that is ALL. :-) Well, it does not remove the problem completely, 93 but exponential growth of network traffic is changed to linear 94 (branches, that exceed pmtu are pruned) and tunnel mtu 95 rapidly degrades to value <68, where looping stops. 96 Yes, it is not good if there exists a router in the loop, 97 which does not force DF, even when encapsulating packets have DF set. 98 But it is not our problem! Nobody could accuse us, we made 99 all that we could make. Even if it is your gated who injected 100 fatal route to network, even if it were you who configured 101 fatal static route: you are innocent. :-) 102 103 Alexey Kuznetsov. 104 */ 105 106static bool log_ecn_error = true; 107module_param(log_ecn_error, bool, 0644); 108MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN"); 109 110static struct rtnl_link_ops ipgre_link_ops __read_mostly; 111static const struct header_ops ipgre_header_ops; 112 113static int ipgre_tunnel_init(struct net_device *dev); 114static void erspan_build_header(struct sk_buff *skb, 115 u32 id, u32 index, 116 bool truncate, bool is_ipv4); 117 118static unsigned int ipgre_net_id __read_mostly; 119static unsigned int gre_tap_net_id __read_mostly; 120static unsigned int erspan_net_id __read_mostly; 121 122static int ipgre_err(struct sk_buff *skb, u32 info, 123 const struct tnl_ptk_info *tpi) 124{ 125 126 /* All the routers (except for Linux) return only 127 8 bytes of packet payload. It means, that precise relaying of 128 ICMP in the real Internet is absolutely infeasible. 129 130 Moreover, Cisco "wise men" put GRE key to the third word 131 in GRE header. It makes impossible maintaining even soft 132 state for keyed GRE tunnels with enabled checksum. Tell 133 them "thank you". 134 135 Well, I wonder, rfc1812 was written by Cisco employee, 136 what the hell these idiots break standards established 137 by themselves??? 138 */ 139 struct net *net = dev_net(skb->dev); 140 struct ip_tunnel_net *itn; 141 const struct iphdr *iph; 142 const int type = icmp_hdr(skb)->type; 143 const int code = icmp_hdr(skb)->code; 144 struct ip_tunnel *t; 145 146 if (tpi->proto == htons(ETH_P_TEB)) 147 itn = net_generic(net, gre_tap_net_id); 148 else if (tpi->proto == htons(ETH_P_ERSPAN) || 149 tpi->proto == htons(ETH_P_ERSPAN2)) 150 itn = net_generic(net, erspan_net_id); 151 else 152 itn = net_generic(net, ipgre_net_id); 153 154 iph = (const struct iphdr *)(icmp_hdr(skb) + 1); 155 t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags, 156 iph->daddr, iph->saddr, tpi->key); 157 158 if (!t) 159 return -ENOENT; 160 161 switch (type) { 162 default: 163 case ICMP_PARAMETERPROB: 164 return 0; 165 166 case ICMP_DEST_UNREACH: 167 switch (code) { 168 case ICMP_SR_FAILED: 169 case ICMP_PORT_UNREACH: 170 /* Impossible event. */ 171 return 0; 172 default: 173 /* All others are translated to HOST_UNREACH. 174 rfc2003 contains "deep thoughts" about NET_UNREACH, 175 I believe they are just ether pollution. --ANK 176 */ 177 break; 178 } 179 break; 180 181 case ICMP_TIME_EXCEEDED: 182 if (code != ICMP_EXC_TTL) 183 return 0; 184 break; 185 186 case ICMP_REDIRECT: 187 break; 188 } 189 190#if IS_ENABLED(CONFIG_IPV6) 191 if (tpi->proto == htons(ETH_P_IPV6)) { 192 unsigned int data_len = 0; 193 194 if (type == ICMP_TIME_EXCEEDED) 195 data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */ 196 197 if (!ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4 + tpi->hdr_len, 198 type, data_len)) 199 return 0; 200 } 201#endif 202 203 if (t->parms.iph.daddr == 0 || 204 ipv4_is_multicast(t->parms.iph.daddr)) 205 return 0; 206 207 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 208 return 0; 209 210 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) 211 t->err_count++; 212 else 213 t->err_count = 1; 214 t->err_time = jiffies; 215 216 return 0; 217} 218 219static void gre_err(struct sk_buff *skb, u32 info) 220{ 221 /* All the routers (except for Linux) return only 222 * 8 bytes of packet payload. It means, that precise relaying of 223 * ICMP in the real Internet is absolutely infeasible. 224 * 225 * Moreover, Cisco "wise men" put GRE key to the third word 226 * in GRE header. It makes impossible maintaining even soft 227 * state for keyed 228 * GRE tunnels with enabled checksum. Tell them "thank you". 229 * 230 * Well, I wonder, rfc1812 was written by Cisco employee, 231 * what the hell these idiots break standards established 232 * by themselves??? 233 */ 234 235 const struct iphdr *iph = (struct iphdr *)skb->data; 236 const int type = icmp_hdr(skb)->type; 237 const int code = icmp_hdr(skb)->code; 238 struct tnl_ptk_info tpi; 239 240 if (gre_parse_header(skb, &tpi, NULL, htons(ETH_P_IP), 241 iph->ihl * 4) < 0) 242 return; 243 244 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { 245 ipv4_update_pmtu(skb, dev_net(skb->dev), info, 246 skb->dev->ifindex, IPPROTO_GRE); 247 return; 248 } 249 if (type == ICMP_REDIRECT) { 250 ipv4_redirect(skb, dev_net(skb->dev), skb->dev->ifindex, 251 IPPROTO_GRE); 252 return; 253 } 254 255 ipgre_err(skb, info, &tpi); 256} 257 258static bool is_erspan_type1(int gre_hdr_len) 259{ 260 /* Both ERSPAN type I (version 0) and type II (version 1) use 261 * protocol 0x88BE, but the type I has only 4-byte GRE header, 262 * while type II has 8-byte. 263 */ 264 return gre_hdr_len == 4; 265} 266 267static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi, 268 int gre_hdr_len) 269{ 270 struct net *net = dev_net(skb->dev); 271 struct metadata_dst *tun_dst = NULL; 272 struct erspan_base_hdr *ershdr; 273 IP_TUNNEL_DECLARE_FLAGS(flags); 274 struct ip_tunnel_net *itn; 275 struct ip_tunnel *tunnel; 276 const struct iphdr *iph; 277 struct erspan_md2 *md2; 278 int ver; 279 int len; 280 281 ip_tunnel_flags_copy(flags, tpi->flags); 282 283 itn = net_generic(net, erspan_net_id); 284 iph = ip_hdr(skb); 285 if (is_erspan_type1(gre_hdr_len)) { 286 ver = 0; 287 __set_bit(IP_TUNNEL_NO_KEY_BIT, flags); 288 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, flags, 289 iph->saddr, iph->daddr, 0); 290 } else { 291 if (unlikely(!pskb_may_pull(skb, 292 gre_hdr_len + sizeof(*ershdr)))) 293 return PACKET_REJECT; 294 295 ershdr = (struct erspan_base_hdr *)(skb->data + gre_hdr_len); 296 ver = ershdr->ver; 297 iph = ip_hdr(skb); 298 __set_bit(IP_TUNNEL_KEY_BIT, flags); 299 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, flags, 300 iph->saddr, iph->daddr, tpi->key); 301 } 302 303 if (tunnel) { 304 if (is_erspan_type1(gre_hdr_len)) 305 len = gre_hdr_len; 306 else 307 len = gre_hdr_len + erspan_hdr_len(ver); 308 309 if (unlikely(!pskb_may_pull(skb, len))) 310 return PACKET_REJECT; 311 312 if (__iptunnel_pull_header(skb, 313 len, 314 htons(ETH_P_TEB), 315 false, false) < 0) 316 goto drop; 317 318 if (tunnel->collect_md) { 319 struct erspan_metadata *pkt_md, *md; 320 struct ip_tunnel_info *info; 321 unsigned char *gh; 322 __be64 tun_id; 323 324 __set_bit(IP_TUNNEL_KEY_BIT, tpi->flags); 325 ip_tunnel_flags_copy(flags, tpi->flags); 326 tun_id = key32_to_tunnel_id(tpi->key); 327 328 tun_dst = ip_tun_rx_dst(skb, flags, 329 tun_id, sizeof(*md)); 330 if (!tun_dst) 331 return PACKET_REJECT; 332 333 /* MUST set options_len before referencing options */ 334 info = &tun_dst->u.tun_info; 335 info->options_len = sizeof(*md); 336 337 /* skb can be uncloned in __iptunnel_pull_header, so 338 * old pkt_md is no longer valid and we need to reset 339 * it 340 */ 341 gh = skb_network_header(skb) + 342 skb_network_header_len(skb); 343 pkt_md = (struct erspan_metadata *)(gh + gre_hdr_len + 344 sizeof(*ershdr)); 345 md = ip_tunnel_info_opts(&tun_dst->u.tun_info); 346 md->version = ver; 347 md2 = &md->u.md2; 348 memcpy(md2, pkt_md, ver == 1 ? ERSPAN_V1_MDSIZE : 349 ERSPAN_V2_MDSIZE); 350 351 __set_bit(IP_TUNNEL_ERSPAN_OPT_BIT, 352 info->key.tun_flags); 353 } 354 355 skb_reset_mac_header(skb); 356 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error); 357 return PACKET_RCVD; 358 } 359 return PACKET_REJECT; 360 361drop: 362 kfree_skb(skb); 363 return PACKET_RCVD; 364} 365 366static int __ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi, 367 struct ip_tunnel_net *itn, int hdr_len, bool raw_proto) 368{ 369 struct metadata_dst *tun_dst = NULL; 370 const struct iphdr *iph; 371 struct ip_tunnel *tunnel; 372 373 iph = ip_hdr(skb); 374 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags, 375 iph->saddr, iph->daddr, tpi->key); 376 377 if (tunnel) { 378 const struct iphdr *tnl_params; 379 380 if (__iptunnel_pull_header(skb, hdr_len, tpi->proto, 381 raw_proto, false) < 0) 382 goto drop; 383 384 /* Special case for ipgre_header_parse(), which expects the 385 * mac_header to point to the outer IP header. 386 */ 387 if (tunnel->dev->header_ops == &ipgre_header_ops) 388 skb_pop_mac_header(skb); 389 else 390 skb_reset_mac_header(skb); 391 392 tnl_params = &tunnel->parms.iph; 393 if (tunnel->collect_md || tnl_params->daddr == 0) { 394 IP_TUNNEL_DECLARE_FLAGS(flags) = { }; 395 __be64 tun_id; 396 397 __set_bit(IP_TUNNEL_CSUM_BIT, flags); 398 __set_bit(IP_TUNNEL_KEY_BIT, flags); 399 ip_tunnel_flags_and(flags, tpi->flags, flags); 400 401 tun_id = key32_to_tunnel_id(tpi->key); 402 tun_dst = ip_tun_rx_dst(skb, flags, tun_id, 0); 403 if (!tun_dst) 404 return PACKET_REJECT; 405 } 406 407 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error); 408 return PACKET_RCVD; 409 } 410 return PACKET_NEXT; 411 412drop: 413 kfree_skb(skb); 414 return PACKET_RCVD; 415} 416 417static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi, 418 int hdr_len) 419{ 420 struct net *net = dev_net(skb->dev); 421 struct ip_tunnel_net *itn; 422 int res; 423 424 if (tpi->proto == htons(ETH_P_TEB)) 425 itn = net_generic(net, gre_tap_net_id); 426 else 427 itn = net_generic(net, ipgre_net_id); 428 429 res = __ipgre_rcv(skb, tpi, itn, hdr_len, false); 430 if (res == PACKET_NEXT && tpi->proto == htons(ETH_P_TEB)) { 431 /* ipgre tunnels in collect metadata mode should receive 432 * also ETH_P_TEB traffic. 433 */ 434 itn = net_generic(net, ipgre_net_id); 435 res = __ipgre_rcv(skb, tpi, itn, hdr_len, true); 436 } 437 return res; 438} 439 440static int gre_rcv(struct sk_buff *skb) 441{ 442 struct tnl_ptk_info tpi; 443 bool csum_err = false; 444 int hdr_len; 445 446#ifdef CONFIG_NET_IPGRE_BROADCAST 447 if (ipv4_is_multicast(ip_hdr(skb)->daddr)) { 448 /* Looped back packet, drop it! */ 449 if (rt_is_output_route(skb_rtable(skb))) 450 goto drop; 451 } 452#endif 453 454 hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IP), 0); 455 if (hdr_len < 0) 456 goto drop; 457 458 if (unlikely(tpi.proto == htons(ETH_P_ERSPAN) || 459 tpi.proto == htons(ETH_P_ERSPAN2))) { 460 if (erspan_rcv(skb, &tpi, hdr_len) == PACKET_RCVD) 461 return 0; 462 goto out; 463 } 464 465 if (ipgre_rcv(skb, &tpi, hdr_len) == PACKET_RCVD) 466 return 0; 467 468out: 469 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 470drop: 471 kfree_skb(skb); 472 return 0; 473} 474 475static void __gre_xmit(struct sk_buff *skb, struct net_device *dev, 476 const struct iphdr *tnl_params, 477 __be16 proto) 478{ 479 struct ip_tunnel *tunnel = netdev_priv(dev); 480 IP_TUNNEL_DECLARE_FLAGS(flags); 481 482 ip_tunnel_flags_copy(flags, tunnel->parms.o_flags); 483 484 /* Push GRE header. */ 485 gre_build_header(skb, tunnel->tun_hlen, 486 flags, proto, tunnel->parms.o_key, 487 test_bit(IP_TUNNEL_SEQ_BIT, flags) ? 488 htonl(atomic_fetch_inc(&tunnel->o_seqno)) : 0); 489 490 ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol); 491} 492 493static int gre_handle_offloads(struct sk_buff *skb, bool csum) 494{ 495 return iptunnel_handle_offloads(skb, csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE); 496} 497 498static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev, 499 __be16 proto) 500{ 501 struct ip_tunnel *tunnel = netdev_priv(dev); 502 IP_TUNNEL_DECLARE_FLAGS(flags) = { }; 503 struct ip_tunnel_info *tun_info; 504 const struct ip_tunnel_key *key; 505 int tunnel_hlen; 506 507 tun_info = skb_tunnel_info(skb); 508 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) || 509 ip_tunnel_info_af(tun_info) != AF_INET)) 510 goto err_free_skb; 511 512 key = &tun_info->key; 513 tunnel_hlen = gre_calc_hlen(key->tun_flags); 514 515 if (skb_cow_head(skb, dev->needed_headroom)) 516 goto err_free_skb; 517 518 /* Push Tunnel header. */ 519 if (gre_handle_offloads(skb, test_bit(IP_TUNNEL_CSUM_BIT, 520 tunnel->parms.o_flags))) 521 goto err_free_skb; 522 523 __set_bit(IP_TUNNEL_CSUM_BIT, flags); 524 __set_bit(IP_TUNNEL_KEY_BIT, flags); 525 __set_bit(IP_TUNNEL_SEQ_BIT, flags); 526 ip_tunnel_flags_and(flags, tun_info->key.tun_flags, flags); 527 528 gre_build_header(skb, tunnel_hlen, flags, proto, 529 tunnel_id_to_key32(tun_info->key.tun_id), 530 test_bit(IP_TUNNEL_SEQ_BIT, flags) ? 531 htonl(atomic_fetch_inc(&tunnel->o_seqno)) : 0); 532 533 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen); 534 535 return; 536 537err_free_skb: 538 kfree_skb(skb); 539 DEV_STATS_INC(dev, tx_dropped); 540} 541 542static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev) 543{ 544 struct ip_tunnel *tunnel = netdev_priv(dev); 545 IP_TUNNEL_DECLARE_FLAGS(flags) = { }; 546 struct ip_tunnel_info *tun_info; 547 const struct ip_tunnel_key *key; 548 struct erspan_metadata *md; 549 bool truncate = false; 550 __be16 proto; 551 int tunnel_hlen; 552 int version; 553 int nhoff; 554 555 tun_info = skb_tunnel_info(skb); 556 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) || 557 ip_tunnel_info_af(tun_info) != AF_INET)) 558 goto err_free_skb; 559 560 key = &tun_info->key; 561 if (!test_bit(IP_TUNNEL_ERSPAN_OPT_BIT, tun_info->key.tun_flags)) 562 goto err_free_skb; 563 if (tun_info->options_len < sizeof(*md)) 564 goto err_free_skb; 565 md = ip_tunnel_info_opts(tun_info); 566 567 /* ERSPAN has fixed 8 byte GRE header */ 568 version = md->version; 569 tunnel_hlen = 8 + erspan_hdr_len(version); 570 571 if (skb_cow_head(skb, dev->needed_headroom)) 572 goto err_free_skb; 573 574 if (gre_handle_offloads(skb, false)) 575 goto err_free_skb; 576 577 if (skb->len > dev->mtu + dev->hard_header_len) { 578 if (pskb_trim(skb, dev->mtu + dev->hard_header_len)) 579 goto err_free_skb; 580 truncate = true; 581 } 582 583 nhoff = skb_network_offset(skb); 584 if (skb->protocol == htons(ETH_P_IP) && 585 (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff)) 586 truncate = true; 587 588 if (skb->protocol == htons(ETH_P_IPV6)) { 589 int thoff; 590 591 if (skb_transport_header_was_set(skb)) 592 thoff = skb_transport_offset(skb); 593 else 594 thoff = nhoff + sizeof(struct ipv6hdr); 595 if (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff) 596 truncate = true; 597 } 598 599 if (version == 1) { 600 erspan_build_header(skb, ntohl(tunnel_id_to_key32(key->tun_id)), 601 ntohl(md->u.index), truncate, true); 602 proto = htons(ETH_P_ERSPAN); 603 } else if (version == 2) { 604 erspan_build_header_v2(skb, 605 ntohl(tunnel_id_to_key32(key->tun_id)), 606 md->u.md2.dir, 607 get_hwid(&md->u.md2), 608 truncate, true); 609 proto = htons(ETH_P_ERSPAN2); 610 } else { 611 goto err_free_skb; 612 } 613 614 __set_bit(IP_TUNNEL_SEQ_BIT, flags); 615 gre_build_header(skb, 8, flags, proto, 0, 616 htonl(atomic_fetch_inc(&tunnel->o_seqno))); 617 618 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen); 619 620 return; 621 622err_free_skb: 623 kfree_skb(skb); 624 DEV_STATS_INC(dev, tx_dropped); 625} 626 627static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb) 628{ 629 struct ip_tunnel_info *info = skb_tunnel_info(skb); 630 const struct ip_tunnel_key *key; 631 struct rtable *rt; 632 struct flowi4 fl4; 633 634 if (ip_tunnel_info_af(info) != AF_INET) 635 return -EINVAL; 636 637 key = &info->key; 638 ip_tunnel_init_flow(&fl4, IPPROTO_GRE, key->u.ipv4.dst, key->u.ipv4.src, 639 tunnel_id_to_key32(key->tun_id), 640 key->tos & ~INET_ECN_MASK, dev_net(dev), 0, 641 skb->mark, skb_get_hash(skb), key->flow_flags); 642 rt = ip_route_output_key(dev_net(dev), &fl4); 643 if (IS_ERR(rt)) 644 return PTR_ERR(rt); 645 646 ip_rt_put(rt); 647 info->key.u.ipv4.src = fl4.saddr; 648 return 0; 649} 650 651static netdev_tx_t ipgre_xmit(struct sk_buff *skb, 652 struct net_device *dev) 653{ 654 struct ip_tunnel *tunnel = netdev_priv(dev); 655 const struct iphdr *tnl_params; 656 657 if (!pskb_inet_may_pull(skb)) 658 goto free_skb; 659 660 if (tunnel->collect_md) { 661 gre_fb_xmit(skb, dev, skb->protocol); 662 return NETDEV_TX_OK; 663 } 664 665 if (dev->header_ops) { 666 int pull_len = tunnel->hlen + sizeof(struct iphdr); 667 668 if (skb_cow_head(skb, 0)) 669 goto free_skb; 670 671 if (!pskb_may_pull(skb, pull_len)) 672 goto free_skb; 673 674 tnl_params = (const struct iphdr *)skb->data; 675 676 /* ip_tunnel_xmit() needs skb->data pointing to gre header. */ 677 skb_pull(skb, pull_len); 678 skb_reset_mac_header(skb); 679 680 if (skb->ip_summed == CHECKSUM_PARTIAL && 681 skb_checksum_start(skb) < skb->data) 682 goto free_skb; 683 } else { 684 if (skb_cow_head(skb, dev->needed_headroom)) 685 goto free_skb; 686 687 tnl_params = &tunnel->parms.iph; 688 } 689 690 if (gre_handle_offloads(skb, test_bit(IP_TUNNEL_CSUM_BIT, 691 tunnel->parms.o_flags))) 692 goto free_skb; 693 694 __gre_xmit(skb, dev, tnl_params, skb->protocol); 695 return NETDEV_TX_OK; 696 697free_skb: 698 kfree_skb(skb); 699 DEV_STATS_INC(dev, tx_dropped); 700 return NETDEV_TX_OK; 701} 702 703static netdev_tx_t erspan_xmit(struct sk_buff *skb, 704 struct net_device *dev) 705{ 706 struct ip_tunnel *tunnel = netdev_priv(dev); 707 bool truncate = false; 708 __be16 proto; 709 710 if (!pskb_inet_may_pull(skb)) 711 goto free_skb; 712 713 if (tunnel->collect_md) { 714 erspan_fb_xmit(skb, dev); 715 return NETDEV_TX_OK; 716 } 717 718 if (gre_handle_offloads(skb, false)) 719 goto free_skb; 720 721 if (skb_cow_head(skb, dev->needed_headroom)) 722 goto free_skb; 723 724 if (skb->len > dev->mtu + dev->hard_header_len) { 725 if (pskb_trim(skb, dev->mtu + dev->hard_header_len)) 726 goto free_skb; 727 truncate = true; 728 } 729 730 /* Push ERSPAN header */ 731 if (tunnel->erspan_ver == 0) { 732 proto = htons(ETH_P_ERSPAN); 733 __clear_bit(IP_TUNNEL_SEQ_BIT, tunnel->parms.o_flags); 734 } else if (tunnel->erspan_ver == 1) { 735 erspan_build_header(skb, ntohl(tunnel->parms.o_key), 736 tunnel->index, 737 truncate, true); 738 proto = htons(ETH_P_ERSPAN); 739 } else if (tunnel->erspan_ver == 2) { 740 erspan_build_header_v2(skb, ntohl(tunnel->parms.o_key), 741 tunnel->dir, tunnel->hwid, 742 truncate, true); 743 proto = htons(ETH_P_ERSPAN2); 744 } else { 745 goto free_skb; 746 } 747 748 __clear_bit(IP_TUNNEL_KEY_BIT, tunnel->parms.o_flags); 749 __gre_xmit(skb, dev, &tunnel->parms.iph, proto); 750 return NETDEV_TX_OK; 751 752free_skb: 753 kfree_skb(skb); 754 DEV_STATS_INC(dev, tx_dropped); 755 return NETDEV_TX_OK; 756} 757 758static netdev_tx_t gre_tap_xmit(struct sk_buff *skb, 759 struct net_device *dev) 760{ 761 struct ip_tunnel *tunnel = netdev_priv(dev); 762 763 if (!pskb_inet_may_pull(skb)) 764 goto free_skb; 765 766 if (tunnel->collect_md) { 767 gre_fb_xmit(skb, dev, htons(ETH_P_TEB)); 768 return NETDEV_TX_OK; 769 } 770 771 if (gre_handle_offloads(skb, test_bit(IP_TUNNEL_CSUM_BIT, 772 tunnel->parms.o_flags))) 773 goto free_skb; 774 775 if (skb_cow_head(skb, dev->needed_headroom)) 776 goto free_skb; 777 778 __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB)); 779 return NETDEV_TX_OK; 780 781free_skb: 782 kfree_skb(skb); 783 DEV_STATS_INC(dev, tx_dropped); 784 return NETDEV_TX_OK; 785} 786 787static void ipgre_link_update(struct net_device *dev, bool set_mtu) 788{ 789 struct ip_tunnel *tunnel = netdev_priv(dev); 790 int len; 791 792 len = tunnel->tun_hlen; 793 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags); 794 len = tunnel->tun_hlen - len; 795 tunnel->hlen = tunnel->hlen + len; 796 797 if (dev->header_ops) 798 dev->hard_header_len += len; 799 else 800 dev->needed_headroom += len; 801 802 if (set_mtu) 803 WRITE_ONCE(dev->mtu, max_t(int, dev->mtu - len, 68)); 804 805 if (test_bit(IP_TUNNEL_SEQ_BIT, tunnel->parms.o_flags) || 806 (test_bit(IP_TUNNEL_CSUM_BIT, tunnel->parms.o_flags) && 807 tunnel->encap.type != TUNNEL_ENCAP_NONE)) { 808 dev->features &= ~NETIF_F_GSO_SOFTWARE; 809 dev->hw_features &= ~NETIF_F_GSO_SOFTWARE; 810 } else { 811 dev->features |= NETIF_F_GSO_SOFTWARE; 812 dev->hw_features |= NETIF_F_GSO_SOFTWARE; 813 } 814} 815 816static int ipgre_tunnel_ctl(struct net_device *dev, 817 struct ip_tunnel_parm_kern *p, 818 int cmd) 819{ 820 __be16 i_flags, o_flags; 821 int err; 822 823 if (!ip_tunnel_flags_is_be16_compat(p->i_flags) || 824 !ip_tunnel_flags_is_be16_compat(p->o_flags)) 825 return -EOVERFLOW; 826 827 i_flags = ip_tunnel_flags_to_be16(p->i_flags); 828 o_flags = ip_tunnel_flags_to_be16(p->o_flags); 829 830 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) { 831 if (p->iph.version != 4 || p->iph.protocol != IPPROTO_GRE || 832 p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)) || 833 ((i_flags | o_flags) & (GRE_VERSION | GRE_ROUTING))) 834 return -EINVAL; 835 } 836 837 gre_flags_to_tnl_flags(p->i_flags, i_flags); 838 gre_flags_to_tnl_flags(p->o_flags, o_flags); 839 840 err = ip_tunnel_ctl(dev, p, cmd); 841 if (err) 842 return err; 843 844 if (cmd == SIOCCHGTUNNEL) { 845 struct ip_tunnel *t = netdev_priv(dev); 846 847 ip_tunnel_flags_copy(t->parms.i_flags, p->i_flags); 848 ip_tunnel_flags_copy(t->parms.o_flags, p->o_flags); 849 850 if (strcmp(dev->rtnl_link_ops->kind, "erspan")) 851 ipgre_link_update(dev, true); 852 } 853 854 i_flags = gre_tnl_flags_to_gre_flags(p->i_flags); 855 ip_tunnel_flags_from_be16(p->i_flags, i_flags); 856 o_flags = gre_tnl_flags_to_gre_flags(p->o_flags); 857 ip_tunnel_flags_from_be16(p->o_flags, o_flags); 858 859 return 0; 860} 861 862/* Nice toy. Unfortunately, useless in real life :-) 863 It allows to construct virtual multiprotocol broadcast "LAN" 864 over the Internet, provided multicast routing is tuned. 865 866 867 I have no idea was this bicycle invented before me, 868 so that I had to set ARPHRD_IPGRE to a random value. 869 I have an impression, that Cisco could make something similar, 870 but this feature is apparently missing in IOS<=11.2(8). 871 872 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks 873 with broadcast 224.66.66.66. If you have access to mbone, play with me :-) 874 875 ping -t 255 224.66.66.66 876 877 If nobody answers, mbone does not work. 878 879 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255 880 ip addr add 10.66.66.<somewhat>/24 dev Universe 881 ifconfig Universe up 882 ifconfig Universe add fe80::<Your_real_addr>/10 883 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96 884 ftp 10.66.66.66 885 ... 886 ftp fec0:6666:6666::193.233.7.65 887 ... 888 */ 889static int ipgre_header(struct sk_buff *skb, struct net_device *dev, 890 unsigned short type, 891 const void *daddr, const void *saddr, unsigned int len) 892{ 893 struct ip_tunnel *t = netdev_priv(dev); 894 struct gre_base_hdr *greh; 895 struct iphdr *iph; 896 int needed; 897 898 needed = t->hlen + sizeof(*iph); 899 if (skb_headroom(skb) < needed && 900 pskb_expand_head(skb, HH_DATA_ALIGN(needed - skb_headroom(skb)), 901 0, GFP_ATOMIC)) 902 return -needed; 903 904 iph = skb_push(skb, needed); 905 greh = (struct gre_base_hdr *)(iph+1); 906 greh->flags = gre_tnl_flags_to_gre_flags(t->parms.o_flags); 907 greh->protocol = htons(type); 908 909 memcpy(iph, &t->parms.iph, sizeof(struct iphdr)); 910 911 /* Set the source hardware address. */ 912 if (saddr) 913 memcpy(&iph->saddr, saddr, 4); 914 if (daddr) 915 memcpy(&iph->daddr, daddr, 4); 916 if (iph->daddr) 917 return t->hlen + sizeof(*iph); 918 919 return -(t->hlen + sizeof(*iph)); 920} 921 922static int ipgre_header_parse(const struct sk_buff *skb, const struct net_device *dev, 923 unsigned char *haddr) 924{ 925 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb); 926 memcpy(haddr, &iph->saddr, 4); 927 return 4; 928} 929 930static const struct header_ops ipgre_header_ops = { 931 .create = ipgre_header, 932 .parse = ipgre_header_parse, 933}; 934 935#ifdef CONFIG_NET_IPGRE_BROADCAST 936static int ipgre_open(struct net_device *dev) 937{ 938 struct ip_tunnel *t = netdev_priv(dev); 939 940 if (ipv4_is_multicast(t->parms.iph.daddr)) { 941 struct flowi4 fl4 = { 942 .flowi4_oif = t->parms.link, 943 .flowi4_dscp = ip4h_dscp(&t->parms.iph), 944 .flowi4_scope = RT_SCOPE_UNIVERSE, 945 .flowi4_proto = IPPROTO_GRE, 946 .saddr = t->parms.iph.saddr, 947 .daddr = t->parms.iph.daddr, 948 .fl4_gre_key = t->parms.o_key, 949 }; 950 struct rtable *rt; 951 952 rt = ip_route_output_key(t->net, &fl4); 953 if (IS_ERR(rt)) 954 return -EADDRNOTAVAIL; 955 dev = rt->dst.dev; 956 ip_rt_put(rt); 957 if (!__in_dev_get_rtnl(dev)) 958 return -EADDRNOTAVAIL; 959 t->mlink = dev->ifindex; 960 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr); 961 } 962 return 0; 963} 964 965static int ipgre_close(struct net_device *dev) 966{ 967 struct ip_tunnel *t = netdev_priv(dev); 968 969 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) { 970 struct in_device *in_dev; 971 in_dev = inetdev_by_index(t->net, t->mlink); 972 if (in_dev) 973 ip_mc_dec_group(in_dev, t->parms.iph.daddr); 974 } 975 return 0; 976} 977#endif 978 979static const struct net_device_ops ipgre_netdev_ops = { 980 .ndo_init = ipgre_tunnel_init, 981 .ndo_uninit = ip_tunnel_uninit, 982#ifdef CONFIG_NET_IPGRE_BROADCAST 983 .ndo_open = ipgre_open, 984 .ndo_stop = ipgre_close, 985#endif 986 .ndo_start_xmit = ipgre_xmit, 987 .ndo_siocdevprivate = ip_tunnel_siocdevprivate, 988 .ndo_change_mtu = ip_tunnel_change_mtu, 989 .ndo_get_stats64 = dev_get_tstats64, 990 .ndo_get_iflink = ip_tunnel_get_iflink, 991 .ndo_tunnel_ctl = ipgre_tunnel_ctl, 992}; 993 994#define GRE_FEATURES (NETIF_F_SG | \ 995 NETIF_F_FRAGLIST | \ 996 NETIF_F_HIGHDMA | \ 997 NETIF_F_HW_CSUM) 998 999static void ipgre_tunnel_setup(struct net_device *dev) 1000{ 1001 dev->netdev_ops = &ipgre_netdev_ops; 1002 dev->type = ARPHRD_IPGRE; 1003 ip_tunnel_setup(dev, ipgre_net_id); 1004} 1005 1006static void __gre_tunnel_init(struct net_device *dev) 1007{ 1008 struct ip_tunnel *tunnel; 1009 1010 tunnel = netdev_priv(dev); 1011 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags); 1012 tunnel->parms.iph.protocol = IPPROTO_GRE; 1013 1014 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen; 1015 dev->needed_headroom = tunnel->hlen + sizeof(tunnel->parms.iph); 1016 1017 dev->features |= GRE_FEATURES; 1018 dev->hw_features |= GRE_FEATURES; 1019 1020 /* TCP offload with GRE SEQ is not supported, nor can we support 2 1021 * levels of outer headers requiring an update. 1022 */ 1023 if (test_bit(IP_TUNNEL_SEQ_BIT, tunnel->parms.o_flags)) 1024 return; 1025 if (test_bit(IP_TUNNEL_CSUM_BIT, tunnel->parms.o_flags) && 1026 tunnel->encap.type != TUNNEL_ENCAP_NONE) 1027 return; 1028 1029 dev->features |= NETIF_F_GSO_SOFTWARE; 1030 dev->hw_features |= NETIF_F_GSO_SOFTWARE; 1031 1032 dev->lltx = true; 1033} 1034 1035static int ipgre_tunnel_init(struct net_device *dev) 1036{ 1037 struct ip_tunnel *tunnel = netdev_priv(dev); 1038 struct iphdr *iph = &tunnel->parms.iph; 1039 1040 __gre_tunnel_init(dev); 1041 1042 __dev_addr_set(dev, &iph->saddr, 4); 1043 memcpy(dev->broadcast, &iph->daddr, 4); 1044 1045 dev->flags = IFF_NOARP; 1046 netif_keep_dst(dev); 1047 dev->addr_len = 4; 1048 1049 if (iph->daddr && !tunnel->collect_md) { 1050#ifdef CONFIG_NET_IPGRE_BROADCAST 1051 if (ipv4_is_multicast(iph->daddr)) { 1052 if (!iph->saddr) 1053 return -EINVAL; 1054 dev->flags = IFF_BROADCAST; 1055 dev->header_ops = &ipgre_header_ops; 1056 dev->hard_header_len = tunnel->hlen + sizeof(*iph); 1057 dev->needed_headroom = 0; 1058 } 1059#endif 1060 } else if (!tunnel->collect_md) { 1061 dev->header_ops = &ipgre_header_ops; 1062 dev->hard_header_len = tunnel->hlen + sizeof(*iph); 1063 dev->needed_headroom = 0; 1064 } 1065 1066 return ip_tunnel_init(dev); 1067} 1068 1069static const struct gre_protocol ipgre_protocol = { 1070 .handler = gre_rcv, 1071 .err_handler = gre_err, 1072}; 1073 1074static int __net_init ipgre_init_net(struct net *net) 1075{ 1076 return ip_tunnel_init_net(net, ipgre_net_id, &ipgre_link_ops, NULL); 1077} 1078 1079static void __net_exit ipgre_exit_rtnl(struct net *net, 1080 struct list_head *dev_to_kill) 1081{ 1082 ip_tunnel_delete_net(net, ipgre_net_id, &ipgre_link_ops, dev_to_kill); 1083} 1084 1085static struct pernet_operations ipgre_net_ops = { 1086 .init = ipgre_init_net, 1087 .exit_rtnl = ipgre_exit_rtnl, 1088 .id = &ipgre_net_id, 1089 .size = sizeof(struct ip_tunnel_net), 1090}; 1091 1092static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[], 1093 struct netlink_ext_ack *extack) 1094{ 1095 __be16 flags; 1096 1097 if (!data) 1098 return 0; 1099 1100 flags = 0; 1101 if (data[IFLA_GRE_IFLAGS]) 1102 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); 1103 if (data[IFLA_GRE_OFLAGS]) 1104 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); 1105 if (flags & (GRE_VERSION|GRE_ROUTING)) 1106 return -EINVAL; 1107 1108 if (data[IFLA_GRE_COLLECT_METADATA] && 1109 data[IFLA_GRE_ENCAP_TYPE] && 1110 nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]) != TUNNEL_ENCAP_NONE) 1111 return -EINVAL; 1112 1113 return 0; 1114} 1115 1116static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[], 1117 struct netlink_ext_ack *extack) 1118{ 1119 __be32 daddr; 1120 1121 if (tb[IFLA_ADDRESS]) { 1122 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) 1123 return -EINVAL; 1124 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) 1125 return -EADDRNOTAVAIL; 1126 } 1127 1128 if (!data) 1129 goto out; 1130 1131 if (data[IFLA_GRE_REMOTE]) { 1132 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4); 1133 if (!daddr) 1134 return -EINVAL; 1135 } 1136 1137out: 1138 return ipgre_tunnel_validate(tb, data, extack); 1139} 1140 1141static int erspan_validate(struct nlattr *tb[], struct nlattr *data[], 1142 struct netlink_ext_ack *extack) 1143{ 1144 __be16 flags = 0; 1145 int ret; 1146 1147 if (!data) 1148 return 0; 1149 1150 ret = ipgre_tap_validate(tb, data, extack); 1151 if (ret) 1152 return ret; 1153 1154 if (data[IFLA_GRE_ERSPAN_VER] && 1155 nla_get_u8(data[IFLA_GRE_ERSPAN_VER]) == 0) 1156 return 0; 1157 1158 /* ERSPAN type II/III should only have GRE sequence and key flag */ 1159 if (data[IFLA_GRE_OFLAGS]) 1160 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); 1161 if (data[IFLA_GRE_IFLAGS]) 1162 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); 1163 if (!data[IFLA_GRE_COLLECT_METADATA] && 1164 flags != (GRE_SEQ | GRE_KEY)) 1165 return -EINVAL; 1166 1167 /* ERSPAN Session ID only has 10-bit. Since we reuse 1168 * 32-bit key field as ID, check it's range. 1169 */ 1170 if (data[IFLA_GRE_IKEY] && 1171 (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK)) 1172 return -EINVAL; 1173 1174 if (data[IFLA_GRE_OKEY] && 1175 (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK)) 1176 return -EINVAL; 1177 1178 return 0; 1179} 1180 1181static int ipgre_netlink_parms(struct net_device *dev, 1182 struct nlattr *data[], 1183 struct nlattr *tb[], 1184 struct ip_tunnel_parm_kern *parms, 1185 __u32 *fwmark) 1186{ 1187 struct ip_tunnel *t = netdev_priv(dev); 1188 1189 memset(parms, 0, sizeof(*parms)); 1190 1191 parms->iph.protocol = IPPROTO_GRE; 1192 1193 if (!data) 1194 return 0; 1195 1196 if (data[IFLA_GRE_LINK]) 1197 parms->link = nla_get_u32(data[IFLA_GRE_LINK]); 1198 1199 if (data[IFLA_GRE_IFLAGS]) 1200 gre_flags_to_tnl_flags(parms->i_flags, 1201 nla_get_be16(data[IFLA_GRE_IFLAGS])); 1202 1203 if (data[IFLA_GRE_OFLAGS]) 1204 gre_flags_to_tnl_flags(parms->o_flags, 1205 nla_get_be16(data[IFLA_GRE_OFLAGS])); 1206 1207 if (data[IFLA_GRE_IKEY]) 1208 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]); 1209 1210 if (data[IFLA_GRE_OKEY]) 1211 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]); 1212 1213 if (data[IFLA_GRE_LOCAL]) 1214 parms->iph.saddr = nla_get_in_addr(data[IFLA_GRE_LOCAL]); 1215 1216 if (data[IFLA_GRE_REMOTE]) 1217 parms->iph.daddr = nla_get_in_addr(data[IFLA_GRE_REMOTE]); 1218 1219 if (data[IFLA_GRE_TTL]) 1220 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]); 1221 1222 if (data[IFLA_GRE_TOS]) 1223 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]); 1224 1225 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC])) { 1226 if (t->ignore_df) 1227 return -EINVAL; 1228 parms->iph.frag_off = htons(IP_DF); 1229 } 1230 1231 if (data[IFLA_GRE_COLLECT_METADATA]) { 1232 t->collect_md = true; 1233 if (dev->type == ARPHRD_IPGRE) 1234 dev->type = ARPHRD_NONE; 1235 } 1236 1237 if (data[IFLA_GRE_IGNORE_DF]) { 1238 if (nla_get_u8(data[IFLA_GRE_IGNORE_DF]) 1239 && (parms->iph.frag_off & htons(IP_DF))) 1240 return -EINVAL; 1241 t->ignore_df = !!nla_get_u8(data[IFLA_GRE_IGNORE_DF]); 1242 } 1243 1244 if (data[IFLA_GRE_FWMARK]) 1245 *fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]); 1246 1247 return 0; 1248} 1249 1250static int erspan_netlink_parms(struct net_device *dev, 1251 struct nlattr *data[], 1252 struct nlattr *tb[], 1253 struct ip_tunnel_parm_kern *parms, 1254 __u32 *fwmark) 1255{ 1256 struct ip_tunnel *t = netdev_priv(dev); 1257 int err; 1258 1259 err = ipgre_netlink_parms(dev, data, tb, parms, fwmark); 1260 if (err) 1261 return err; 1262 if (!data) 1263 return 0; 1264 1265 if (data[IFLA_GRE_ERSPAN_VER]) { 1266 t->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]); 1267 1268 if (t->erspan_ver > 2) 1269 return -EINVAL; 1270 } 1271 1272 if (t->erspan_ver == 1) { 1273 if (data[IFLA_GRE_ERSPAN_INDEX]) { 1274 t->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]); 1275 if (t->index & ~INDEX_MASK) 1276 return -EINVAL; 1277 } 1278 } else if (t->erspan_ver == 2) { 1279 if (data[IFLA_GRE_ERSPAN_DIR]) { 1280 t->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]); 1281 if (t->dir & ~(DIR_MASK >> DIR_OFFSET)) 1282 return -EINVAL; 1283 } 1284 if (data[IFLA_GRE_ERSPAN_HWID]) { 1285 t->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]); 1286 if (t->hwid & ~(HWID_MASK >> HWID_OFFSET)) 1287 return -EINVAL; 1288 } 1289 } 1290 1291 return 0; 1292} 1293 1294/* This function returns true when ENCAP attributes are present in the nl msg */ 1295static bool ipgre_netlink_encap_parms(struct nlattr *data[], 1296 struct ip_tunnel_encap *ipencap) 1297{ 1298 bool ret = false; 1299 1300 memset(ipencap, 0, sizeof(*ipencap)); 1301 1302 if (!data) 1303 return ret; 1304 1305 if (data[IFLA_GRE_ENCAP_TYPE]) { 1306 ret = true; 1307 ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]); 1308 } 1309 1310 if (data[IFLA_GRE_ENCAP_FLAGS]) { 1311 ret = true; 1312 ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]); 1313 } 1314 1315 if (data[IFLA_GRE_ENCAP_SPORT]) { 1316 ret = true; 1317 ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]); 1318 } 1319 1320 if (data[IFLA_GRE_ENCAP_DPORT]) { 1321 ret = true; 1322 ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]); 1323 } 1324 1325 return ret; 1326} 1327 1328static int gre_tap_init(struct net_device *dev) 1329{ 1330 __gre_tunnel_init(dev); 1331 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1332 netif_keep_dst(dev); 1333 1334 return ip_tunnel_init(dev); 1335} 1336 1337static const struct net_device_ops gre_tap_netdev_ops = { 1338 .ndo_init = gre_tap_init, 1339 .ndo_uninit = ip_tunnel_uninit, 1340 .ndo_start_xmit = gre_tap_xmit, 1341 .ndo_set_mac_address = eth_mac_addr, 1342 .ndo_validate_addr = eth_validate_addr, 1343 .ndo_change_mtu = ip_tunnel_change_mtu, 1344 .ndo_get_stats64 = dev_get_tstats64, 1345 .ndo_get_iflink = ip_tunnel_get_iflink, 1346 .ndo_fill_metadata_dst = gre_fill_metadata_dst, 1347}; 1348 1349static int erspan_tunnel_init(struct net_device *dev) 1350{ 1351 struct ip_tunnel *tunnel = netdev_priv(dev); 1352 1353 if (tunnel->erspan_ver == 0) 1354 tunnel->tun_hlen = 4; /* 4-byte GRE hdr. */ 1355 else 1356 tunnel->tun_hlen = 8; /* 8-byte GRE hdr. */ 1357 1358 tunnel->parms.iph.protocol = IPPROTO_GRE; 1359 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen + 1360 erspan_hdr_len(tunnel->erspan_ver); 1361 1362 dev->features |= GRE_FEATURES; 1363 dev->hw_features |= GRE_FEATURES; 1364 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1365 netif_keep_dst(dev); 1366 1367 return ip_tunnel_init(dev); 1368} 1369 1370static const struct net_device_ops erspan_netdev_ops = { 1371 .ndo_init = erspan_tunnel_init, 1372 .ndo_uninit = ip_tunnel_uninit, 1373 .ndo_start_xmit = erspan_xmit, 1374 .ndo_set_mac_address = eth_mac_addr, 1375 .ndo_validate_addr = eth_validate_addr, 1376 .ndo_change_mtu = ip_tunnel_change_mtu, 1377 .ndo_get_stats64 = dev_get_tstats64, 1378 .ndo_get_iflink = ip_tunnel_get_iflink, 1379 .ndo_fill_metadata_dst = gre_fill_metadata_dst, 1380}; 1381 1382static void ipgre_tap_setup(struct net_device *dev) 1383{ 1384 ether_setup(dev); 1385 dev->max_mtu = 0; 1386 dev->netdev_ops = &gre_tap_netdev_ops; 1387 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 1388 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1389 ip_tunnel_setup(dev, gre_tap_net_id); 1390} 1391 1392static int 1393ipgre_newlink_encap_setup(struct net_device *dev, struct nlattr *data[]) 1394{ 1395 struct ip_tunnel_encap ipencap; 1396 1397 if (ipgre_netlink_encap_parms(data, &ipencap)) { 1398 struct ip_tunnel *t = netdev_priv(dev); 1399 int err = ip_tunnel_encap_setup(t, &ipencap); 1400 1401 if (err < 0) 1402 return err; 1403 } 1404 1405 return 0; 1406} 1407 1408static int ipgre_newlink(struct net_device *dev, 1409 struct rtnl_newlink_params *params, 1410 struct netlink_ext_ack *extack) 1411{ 1412 struct nlattr **data = params->data; 1413 struct nlattr **tb = params->tb; 1414 struct ip_tunnel_parm_kern p; 1415 __u32 fwmark = 0; 1416 int err; 1417 1418 err = ipgre_newlink_encap_setup(dev, data); 1419 if (err) 1420 return err; 1421 1422 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark); 1423 if (err < 0) 1424 return err; 1425 return ip_tunnel_newlink(params->link_net ? : dev_net(dev), dev, tb, &p, 1426 fwmark); 1427} 1428 1429static int erspan_newlink(struct net_device *dev, 1430 struct rtnl_newlink_params *params, 1431 struct netlink_ext_ack *extack) 1432{ 1433 struct nlattr **data = params->data; 1434 struct nlattr **tb = params->tb; 1435 struct ip_tunnel_parm_kern p; 1436 __u32 fwmark = 0; 1437 int err; 1438 1439 err = ipgre_newlink_encap_setup(dev, data); 1440 if (err) 1441 return err; 1442 1443 err = erspan_netlink_parms(dev, data, tb, &p, &fwmark); 1444 if (err) 1445 return err; 1446 return ip_tunnel_newlink(params->link_net ? : dev_net(dev), dev, tb, &p, 1447 fwmark); 1448} 1449 1450static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[], 1451 struct nlattr *data[], 1452 struct netlink_ext_ack *extack) 1453{ 1454 struct ip_tunnel *t = netdev_priv(dev); 1455 struct ip_tunnel_parm_kern p; 1456 __u32 fwmark = t->fwmark; 1457 int err; 1458 1459 err = ipgre_newlink_encap_setup(dev, data); 1460 if (err) 1461 return err; 1462 1463 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark); 1464 if (err < 0) 1465 return err; 1466 1467 err = ip_tunnel_changelink(dev, tb, &p, fwmark); 1468 if (err < 0) 1469 return err; 1470 1471 ip_tunnel_flags_copy(t->parms.i_flags, p.i_flags); 1472 ip_tunnel_flags_copy(t->parms.o_flags, p.o_flags); 1473 1474 ipgre_link_update(dev, !tb[IFLA_MTU]); 1475 1476 return 0; 1477} 1478 1479static int erspan_changelink(struct net_device *dev, struct nlattr *tb[], 1480 struct nlattr *data[], 1481 struct netlink_ext_ack *extack) 1482{ 1483 struct ip_tunnel *t = netdev_priv(dev); 1484 struct ip_tunnel_parm_kern p; 1485 __u32 fwmark = t->fwmark; 1486 int err; 1487 1488 err = ipgre_newlink_encap_setup(dev, data); 1489 if (err) 1490 return err; 1491 1492 err = erspan_netlink_parms(dev, data, tb, &p, &fwmark); 1493 if (err < 0) 1494 return err; 1495 1496 err = ip_tunnel_changelink(dev, tb, &p, fwmark); 1497 if (err < 0) 1498 return err; 1499 1500 ip_tunnel_flags_copy(t->parms.i_flags, p.i_flags); 1501 ip_tunnel_flags_copy(t->parms.o_flags, p.o_flags); 1502 1503 return 0; 1504} 1505 1506static size_t ipgre_get_size(const struct net_device *dev) 1507{ 1508 return 1509 /* IFLA_GRE_LINK */ 1510 nla_total_size(4) + 1511 /* IFLA_GRE_IFLAGS */ 1512 nla_total_size(2) + 1513 /* IFLA_GRE_OFLAGS */ 1514 nla_total_size(2) + 1515 /* IFLA_GRE_IKEY */ 1516 nla_total_size(4) + 1517 /* IFLA_GRE_OKEY */ 1518 nla_total_size(4) + 1519 /* IFLA_GRE_LOCAL */ 1520 nla_total_size(4) + 1521 /* IFLA_GRE_REMOTE */ 1522 nla_total_size(4) + 1523 /* IFLA_GRE_TTL */ 1524 nla_total_size(1) + 1525 /* IFLA_GRE_TOS */ 1526 nla_total_size(1) + 1527 /* IFLA_GRE_PMTUDISC */ 1528 nla_total_size(1) + 1529 /* IFLA_GRE_ENCAP_TYPE */ 1530 nla_total_size(2) + 1531 /* IFLA_GRE_ENCAP_FLAGS */ 1532 nla_total_size(2) + 1533 /* IFLA_GRE_ENCAP_SPORT */ 1534 nla_total_size(2) + 1535 /* IFLA_GRE_ENCAP_DPORT */ 1536 nla_total_size(2) + 1537 /* IFLA_GRE_COLLECT_METADATA */ 1538 nla_total_size(0) + 1539 /* IFLA_GRE_IGNORE_DF */ 1540 nla_total_size(1) + 1541 /* IFLA_GRE_FWMARK */ 1542 nla_total_size(4) + 1543 /* IFLA_GRE_ERSPAN_INDEX */ 1544 nla_total_size(4) + 1545 /* IFLA_GRE_ERSPAN_VER */ 1546 nla_total_size(1) + 1547 /* IFLA_GRE_ERSPAN_DIR */ 1548 nla_total_size(1) + 1549 /* IFLA_GRE_ERSPAN_HWID */ 1550 nla_total_size(2) + 1551 0; 1552} 1553 1554static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev) 1555{ 1556 struct ip_tunnel *t = netdev_priv(dev); 1557 struct ip_tunnel_parm_kern *p = &t->parms; 1558 IP_TUNNEL_DECLARE_FLAGS(o_flags); 1559 1560 ip_tunnel_flags_copy(o_flags, p->o_flags); 1561 1562 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) || 1563 nla_put_be16(skb, IFLA_GRE_IFLAGS, 1564 gre_tnl_flags_to_gre_flags(p->i_flags)) || 1565 nla_put_be16(skb, IFLA_GRE_OFLAGS, 1566 gre_tnl_flags_to_gre_flags(o_flags)) || 1567 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) || 1568 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) || 1569 nla_put_in_addr(skb, IFLA_GRE_LOCAL, p->iph.saddr) || 1570 nla_put_in_addr(skb, IFLA_GRE_REMOTE, p->iph.daddr) || 1571 nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) || 1572 nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) || 1573 nla_put_u8(skb, IFLA_GRE_PMTUDISC, 1574 !!(p->iph.frag_off & htons(IP_DF))) || 1575 nla_put_u32(skb, IFLA_GRE_FWMARK, t->fwmark)) 1576 goto nla_put_failure; 1577 1578 if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE, 1579 t->encap.type) || 1580 nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT, 1581 t->encap.sport) || 1582 nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT, 1583 t->encap.dport) || 1584 nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS, 1585 t->encap.flags)) 1586 goto nla_put_failure; 1587 1588 if (nla_put_u8(skb, IFLA_GRE_IGNORE_DF, t->ignore_df)) 1589 goto nla_put_failure; 1590 1591 if (t->collect_md) { 1592 if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA)) 1593 goto nla_put_failure; 1594 } 1595 1596 return 0; 1597 1598nla_put_failure: 1599 return -EMSGSIZE; 1600} 1601 1602static int erspan_fill_info(struct sk_buff *skb, const struct net_device *dev) 1603{ 1604 struct ip_tunnel *t = netdev_priv(dev); 1605 1606 if (t->erspan_ver <= 2) { 1607 if (t->erspan_ver != 0 && !t->collect_md) 1608 __set_bit(IP_TUNNEL_KEY_BIT, t->parms.o_flags); 1609 1610 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, t->erspan_ver)) 1611 goto nla_put_failure; 1612 1613 if (t->erspan_ver == 1) { 1614 if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, t->index)) 1615 goto nla_put_failure; 1616 } else if (t->erspan_ver == 2) { 1617 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, t->dir)) 1618 goto nla_put_failure; 1619 if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, t->hwid)) 1620 goto nla_put_failure; 1621 } 1622 } 1623 1624 return ipgre_fill_info(skb, dev); 1625 1626nla_put_failure: 1627 return -EMSGSIZE; 1628} 1629 1630static void erspan_setup(struct net_device *dev) 1631{ 1632 struct ip_tunnel *t = netdev_priv(dev); 1633 1634 ether_setup(dev); 1635 dev->max_mtu = 0; 1636 dev->netdev_ops = &erspan_netdev_ops; 1637 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 1638 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1639 ip_tunnel_setup(dev, erspan_net_id); 1640 t->erspan_ver = 1; 1641} 1642 1643static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = { 1644 [IFLA_GRE_LINK] = { .type = NLA_U32 }, 1645 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 }, 1646 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 }, 1647 [IFLA_GRE_IKEY] = { .type = NLA_U32 }, 1648 [IFLA_GRE_OKEY] = { .type = NLA_U32 }, 1649 [IFLA_GRE_LOCAL] = { .len = sizeof_field(struct iphdr, saddr) }, 1650 [IFLA_GRE_REMOTE] = { .len = sizeof_field(struct iphdr, daddr) }, 1651 [IFLA_GRE_TTL] = { .type = NLA_U8 }, 1652 [IFLA_GRE_TOS] = { .type = NLA_U8 }, 1653 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 }, 1654 [IFLA_GRE_ENCAP_TYPE] = { .type = NLA_U16 }, 1655 [IFLA_GRE_ENCAP_FLAGS] = { .type = NLA_U16 }, 1656 [IFLA_GRE_ENCAP_SPORT] = { .type = NLA_U16 }, 1657 [IFLA_GRE_ENCAP_DPORT] = { .type = NLA_U16 }, 1658 [IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG }, 1659 [IFLA_GRE_IGNORE_DF] = { .type = NLA_U8 }, 1660 [IFLA_GRE_FWMARK] = { .type = NLA_U32 }, 1661 [IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 }, 1662 [IFLA_GRE_ERSPAN_VER] = { .type = NLA_U8 }, 1663 [IFLA_GRE_ERSPAN_DIR] = { .type = NLA_U8 }, 1664 [IFLA_GRE_ERSPAN_HWID] = { .type = NLA_U16 }, 1665}; 1666 1667static struct rtnl_link_ops ipgre_link_ops __read_mostly = { 1668 .kind = "gre", 1669 .maxtype = IFLA_GRE_MAX, 1670 .policy = ipgre_policy, 1671 .priv_size = sizeof(struct ip_tunnel), 1672 .setup = ipgre_tunnel_setup, 1673 .validate = ipgre_tunnel_validate, 1674 .newlink = ipgre_newlink, 1675 .changelink = ipgre_changelink, 1676 .dellink = ip_tunnel_dellink, 1677 .get_size = ipgre_get_size, 1678 .fill_info = ipgre_fill_info, 1679 .get_link_net = ip_tunnel_get_link_net, 1680}; 1681 1682static struct rtnl_link_ops ipgre_tap_ops __read_mostly = { 1683 .kind = "gretap", 1684 .maxtype = IFLA_GRE_MAX, 1685 .policy = ipgre_policy, 1686 .priv_size = sizeof(struct ip_tunnel), 1687 .setup = ipgre_tap_setup, 1688 .validate = ipgre_tap_validate, 1689 .newlink = ipgre_newlink, 1690 .changelink = ipgre_changelink, 1691 .dellink = ip_tunnel_dellink, 1692 .get_size = ipgre_get_size, 1693 .fill_info = ipgre_fill_info, 1694 .get_link_net = ip_tunnel_get_link_net, 1695}; 1696 1697static struct rtnl_link_ops erspan_link_ops __read_mostly = { 1698 .kind = "erspan", 1699 .maxtype = IFLA_GRE_MAX, 1700 .policy = ipgre_policy, 1701 .priv_size = sizeof(struct ip_tunnel), 1702 .setup = erspan_setup, 1703 .validate = erspan_validate, 1704 .newlink = erspan_newlink, 1705 .changelink = erspan_changelink, 1706 .dellink = ip_tunnel_dellink, 1707 .get_size = ipgre_get_size, 1708 .fill_info = erspan_fill_info, 1709 .get_link_net = ip_tunnel_get_link_net, 1710}; 1711 1712struct net_device *gretap_fb_dev_create(struct net *net, const char *name, 1713 u8 name_assign_type) 1714{ 1715 struct rtnl_newlink_params params = { .src_net = net }; 1716 struct nlattr *tb[IFLA_MAX + 1]; 1717 struct net_device *dev; 1718 LIST_HEAD(list_kill); 1719 struct ip_tunnel *t; 1720 int err; 1721 1722 memset(&tb, 0, sizeof(tb)); 1723 params.tb = tb; 1724 1725 dev = rtnl_create_link(net, name, name_assign_type, 1726 &ipgre_tap_ops, tb, NULL); 1727 if (IS_ERR(dev)) 1728 return dev; 1729 1730 /* Configure flow based GRE device. */ 1731 t = netdev_priv(dev); 1732 t->collect_md = true; 1733 1734 err = ipgre_newlink(dev, ¶ms, NULL); 1735 if (err < 0) { 1736 free_netdev(dev); 1737 return ERR_PTR(err); 1738 } 1739 1740 /* openvswitch users expect packet sizes to be unrestricted, 1741 * so set the largest MTU we can. 1742 */ 1743 err = __ip_tunnel_change_mtu(dev, IP_MAX_MTU, false); 1744 if (err) 1745 goto out; 1746 1747 err = rtnl_configure_link(dev, NULL, 0, NULL); 1748 if (err < 0) 1749 goto out; 1750 1751 return dev; 1752out: 1753 ip_tunnel_dellink(dev, &list_kill); 1754 unregister_netdevice_many(&list_kill); 1755 return ERR_PTR(err); 1756} 1757EXPORT_SYMBOL_GPL(gretap_fb_dev_create); 1758 1759static int __net_init ipgre_tap_init_net(struct net *net) 1760{ 1761 return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, "gretap0"); 1762} 1763 1764static void __net_exit ipgre_tap_exit_rtnl(struct net *net, 1765 struct list_head *dev_to_kill) 1766{ 1767 ip_tunnel_delete_net(net, gre_tap_net_id, &ipgre_tap_ops, dev_to_kill); 1768} 1769 1770static struct pernet_operations ipgre_tap_net_ops = { 1771 .init = ipgre_tap_init_net, 1772 .exit_rtnl = ipgre_tap_exit_rtnl, 1773 .id = &gre_tap_net_id, 1774 .size = sizeof(struct ip_tunnel_net), 1775}; 1776 1777static int __net_init erspan_init_net(struct net *net) 1778{ 1779 return ip_tunnel_init_net(net, erspan_net_id, 1780 &erspan_link_ops, "erspan0"); 1781} 1782 1783static void __net_exit erspan_exit_rtnl(struct net *net, 1784 struct list_head *dev_to_kill) 1785{ 1786 ip_tunnel_delete_net(net, erspan_net_id, &erspan_link_ops, dev_to_kill); 1787} 1788 1789static struct pernet_operations erspan_net_ops = { 1790 .init = erspan_init_net, 1791 .exit_rtnl = erspan_exit_rtnl, 1792 .id = &erspan_net_id, 1793 .size = sizeof(struct ip_tunnel_net), 1794}; 1795 1796static int __init ipgre_init(void) 1797{ 1798 int err; 1799 1800 pr_info("GRE over IPv4 tunneling driver\n"); 1801 1802 err = register_pernet_device(&ipgre_net_ops); 1803 if (err < 0) 1804 return err; 1805 1806 err = register_pernet_device(&ipgre_tap_net_ops); 1807 if (err < 0) 1808 goto pnet_tap_failed; 1809 1810 err = register_pernet_device(&erspan_net_ops); 1811 if (err < 0) 1812 goto pnet_erspan_failed; 1813 1814 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO); 1815 if (err < 0) { 1816 pr_info("%s: can't add protocol\n", __func__); 1817 goto add_proto_failed; 1818 } 1819 1820 err = rtnl_link_register(&ipgre_link_ops); 1821 if (err < 0) 1822 goto rtnl_link_failed; 1823 1824 err = rtnl_link_register(&ipgre_tap_ops); 1825 if (err < 0) 1826 goto tap_ops_failed; 1827 1828 err = rtnl_link_register(&erspan_link_ops); 1829 if (err < 0) 1830 goto erspan_link_failed; 1831 1832 return 0; 1833 1834erspan_link_failed: 1835 rtnl_link_unregister(&ipgre_tap_ops); 1836tap_ops_failed: 1837 rtnl_link_unregister(&ipgre_link_ops); 1838rtnl_link_failed: 1839 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); 1840add_proto_failed: 1841 unregister_pernet_device(&erspan_net_ops); 1842pnet_erspan_failed: 1843 unregister_pernet_device(&ipgre_tap_net_ops); 1844pnet_tap_failed: 1845 unregister_pernet_device(&ipgre_net_ops); 1846 return err; 1847} 1848 1849static void __exit ipgre_fini(void) 1850{ 1851 rtnl_link_unregister(&ipgre_tap_ops); 1852 rtnl_link_unregister(&ipgre_link_ops); 1853 rtnl_link_unregister(&erspan_link_ops); 1854 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); 1855 unregister_pernet_device(&ipgre_tap_net_ops); 1856 unregister_pernet_device(&ipgre_net_ops); 1857 unregister_pernet_device(&erspan_net_ops); 1858} 1859 1860module_init(ipgre_init); 1861module_exit(ipgre_fini); 1862MODULE_DESCRIPTION("IPv4 GRE tunnels over IP library"); 1863MODULE_LICENSE("GPL"); 1864MODULE_ALIAS_RTNL_LINK("gre"); 1865MODULE_ALIAS_RTNL_LINK("gretap"); 1866MODULE_ALIAS_RTNL_LINK("erspan"); 1867MODULE_ALIAS_NETDEV("gre0"); 1868MODULE_ALIAS_NETDEV("gretap0"); 1869MODULE_ALIAS_NETDEV("erspan0");
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