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 */ 105 106 static bool log_ecn_error = true; 107 module_param(log_ecn_error, bool, 0644); 108 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN"); 109 110 static struct rtnl_link_ops ipgre_link_ops __read_mostly; 111 static const struct header_ops ipgre_header_ops; 112 113 static int ipgre_tunnel_init(struct net_device *dev); 114 static void erspan_build_header(struct sk_buff *skb, 115 u32 id, u32 index, 116 bool truncate, bool is_ipv4); 117 118 static unsigned int ipgre_net_id __read_mostly; 119 static unsigned int gre_tap_net_id __read_mostly; 120 static unsigned int erspan_net_id __read_mostly; 121 122 static 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, READ_ONCE(t->err_time) + IPTUNNEL_ERR_TIMEO)) 211 WRITE_ONCE(t->err_count, READ_ONCE(t->err_count) + 1); 212 else 213 WRITE_ONCE(t->err_count, 1); 214 WRITE_ONCE(t->err_time, jiffies); 215 216 return 0; 217 } 218 219 static 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 } 257 258 static 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 } 266 267 static 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)) 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; 360 361 drop: 362 kfree_skb(skb); 363 return PACKET_RCVD; 364 } 365 366 static 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)) 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; 411 412 drop: 413 kfree_skb(skb); 414 return PACKET_RCVD; 415 } 416 417 static 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 } 439 440 static 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; 467 468 out: 469 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 470 drop: 471 dev_core_stats_rx_dropped_inc(skb->dev); 472 kfree_skb(skb); 473 return 0; 474 } 475 476 static void __gre_xmit(struct sk_buff *skb, struct net_device *dev, 477 const struct iphdr *tnl_params, 478 __be16 proto, const unsigned long *flags) 479 { 480 struct ip_tunnel *tunnel = netdev_priv(dev); 481 482 /* Push GRE header. */ 483 gre_build_header(skb, tunnel->tun_hlen, 484 flags, proto, tunnel->parms.o_key, 485 test_bit(IP_TUNNEL_SEQ_BIT, flags) ? 486 htonl(atomic_fetch_inc(&tunnel->o_seqno)) : 0); 487 488 ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol); 489 } 490 491 static int gre_handle_offloads(struct sk_buff *skb, bool csum) 492 { 493 return iptunnel_handle_offloads(skb, csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE); 494 } 495 496 static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev, 497 __be16 proto) 498 { 499 struct ip_tunnel *tunnel = netdev_priv(dev); 500 IP_TUNNEL_DECLARE_FLAGS(flags) = { }; 501 struct ip_tunnel_info *tun_info; 502 const struct ip_tunnel_key *key; 503 int tunnel_hlen; 504 505 tun_info = skb_tunnel_info(skb); 506 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) || 507 ip_tunnel_info_af(tun_info) != AF_INET)) 508 goto err_free_skb; 509 510 key = &tun_info->key; 511 tunnel_hlen = gre_calc_hlen(key->tun_flags); 512 513 if (skb_cow_head(skb, dev->needed_headroom)) 514 goto err_free_skb; 515 516 /* Push Tunnel header. */ 517 if (gre_handle_offloads(skb, test_bit(IP_TUNNEL_CSUM_BIT, 518 tunnel->parms.o_flags))) 519 goto err_free_skb; 520 521 __set_bit(IP_TUNNEL_CSUM_BIT, flags); 522 __set_bit(IP_TUNNEL_KEY_BIT, flags); 523 __set_bit(IP_TUNNEL_SEQ_BIT, flags); 524 ip_tunnel_flags_and(flags, tun_info->key.tun_flags, flags); 525 526 gre_build_header(skb, tunnel_hlen, flags, proto, 527 tunnel_id_to_key32(tun_info->key.tun_id), 528 test_bit(IP_TUNNEL_SEQ_BIT, flags) ? 529 htonl(atomic_fetch_inc(&tunnel->o_seqno)) : 0); 530 531 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen); 532 533 return; 534 535 err_free_skb: 536 kfree_skb(skb); 537 DEV_STATS_INC(dev, tx_dropped); 538 } 539 540 static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev) 541 { 542 struct ip_tunnel *tunnel = netdev_priv(dev); 543 IP_TUNNEL_DECLARE_FLAGS(flags) = { }; 544 struct ip_tunnel_info *tun_info; 545 const struct ip_tunnel_key *key; 546 struct erspan_metadata *md; 547 bool truncate = false; 548 __be16 proto; 549 int tunnel_hlen; 550 int version; 551 int nhoff; 552 553 tun_info = skb_tunnel_info(skb); 554 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) || 555 ip_tunnel_info_af(tun_info) != AF_INET)) 556 goto err_free_skb; 557 558 key = &tun_info->key; 559 if (!test_bit(IP_TUNNEL_ERSPAN_OPT_BIT, tun_info->key.tun_flags)) 560 goto err_free_skb; 561 if (tun_info->options_len < sizeof(*md)) 562 goto err_free_skb; 563 md = ip_tunnel_info_opts(tun_info); 564 565 /* ERSPAN has fixed 8 byte GRE header */ 566 version = md->version; 567 tunnel_hlen = 8 + erspan_hdr_len(version); 568 569 if (skb_cow_head(skb, dev->needed_headroom)) 570 goto err_free_skb; 571 572 if (gre_handle_offloads(skb, false)) 573 goto err_free_skb; 574 575 if (skb->len > dev->mtu + dev->hard_header_len) { 576 if (pskb_trim(skb, dev->mtu + dev->hard_header_len)) 577 goto err_free_skb; 578 truncate = true; 579 } 580 581 nhoff = skb_network_offset(skb); 582 if (skb->protocol == htons(ETH_P_IP) && 583 (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff)) 584 truncate = true; 585 586 if (skb->protocol == htons(ETH_P_IPV6)) { 587 int thoff; 588 589 if (skb_transport_header_was_set(skb)) 590 thoff = skb_transport_offset(skb); 591 else 592 thoff = nhoff + sizeof(struct ipv6hdr); 593 if (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff) 594 truncate = true; 595 } 596 597 if (version == 1) { 598 erspan_build_header(skb, ntohl(tunnel_id_to_key32(key->tun_id)), 599 ntohl(md->u.index), truncate, true); 600 proto = htons(ETH_P_ERSPAN); 601 } else if (version == 2) { 602 erspan_build_header_v2(skb, 603 ntohl(tunnel_id_to_key32(key->tun_id)), 604 md->u.md2.dir, 605 get_hwid(&md->u.md2), 606 truncate, true); 607 proto = htons(ETH_P_ERSPAN2); 608 } else { 609 goto err_free_skb; 610 } 611 612 __set_bit(IP_TUNNEL_SEQ_BIT, flags); 613 gre_build_header(skb, 8, flags, proto, 0, 614 htonl(atomic_fetch_inc(&tunnel->o_seqno))); 615 616 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen); 617 618 return; 619 620 err_free_skb: 621 kfree_skb(skb); 622 DEV_STATS_INC(dev, tx_dropped); 623 } 624 625 static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb) 626 { 627 struct ip_tunnel_info *info = skb_tunnel_info(skb); 628 const struct ip_tunnel_key *key; 629 struct rtable *rt; 630 struct flowi4 fl4; 631 632 if (ip_tunnel_info_af(info) != AF_INET) 633 return -EINVAL; 634 635 key = &info->key; 636 ip_tunnel_init_flow(&fl4, IPPROTO_GRE, key->u.ipv4.dst, key->u.ipv4.src, 637 tunnel_id_to_key32(key->tun_id), 638 key->tos & ~INET_ECN_MASK, dev_net(dev), 0, 639 skb->mark, skb_get_hash(skb), key->flow_flags); 640 rt = ip_route_output_key(dev_net(dev), &fl4); 641 if (IS_ERR(rt)) 642 return PTR_ERR(rt); 643 644 ip_rt_put(rt); 645 info->key.u.ipv4.src = fl4.saddr; 646 return 0; 647 } 648 649 static netdev_tx_t ipgre_xmit(struct sk_buff *skb, 650 struct net_device *dev) 651 { 652 struct ip_tunnel *tunnel = netdev_priv(dev); 653 IP_TUNNEL_DECLARE_FLAGS(flags); 654 const struct iphdr *tnl_params; 655 656 if (!pskb_inet_may_pull(skb)) 657 goto free_skb; 658 659 if (tunnel->collect_md) { 660 gre_fb_xmit(skb, dev, skb->protocol); 661 return NETDEV_TX_OK; 662 } 663 664 if (dev->header_ops) { 665 int pull_len = tunnel->hlen + sizeof(struct iphdr); 666 667 if (skb_cow_head(skb, 0)) 668 goto free_skb; 669 670 if (!pskb_may_pull(skb, pull_len)) 671 goto free_skb; 672 673 tnl_params = (const struct iphdr *)skb->data; 674 675 /* ip_tunnel_xmit() needs skb->data pointing to gre header. */ 676 skb_pull(skb, pull_len); 677 skb_reset_mac_header(skb); 678 679 if (skb->ip_summed == CHECKSUM_PARTIAL && 680 skb_checksum_start(skb) < skb->data) 681 goto free_skb; 682 } else { 683 if (skb_cow_head(skb, dev->needed_headroom)) 684 goto free_skb; 685 686 tnl_params = &tunnel->parms.iph; 687 } 688 689 ip_tunnel_flags_copy(flags, tunnel->parms.o_flags); 690 691 if (gre_handle_offloads(skb, test_bit(IP_TUNNEL_CSUM_BIT, flags))) 692 goto free_skb; 693 694 __gre_xmit(skb, dev, tnl_params, skb->protocol, flags); 695 return NETDEV_TX_OK; 696 697 free_skb: 698 kfree_skb(skb); 699 DEV_STATS_INC(dev, tx_dropped); 700 return NETDEV_TX_OK; 701 } 702 703 static netdev_tx_t erspan_xmit(struct sk_buff *skb, 704 struct net_device *dev) 705 { 706 struct ip_tunnel *tunnel = netdev_priv(dev); 707 IP_TUNNEL_DECLARE_FLAGS(flags); 708 bool truncate = false; 709 __be16 proto; 710 711 if (!pskb_inet_may_pull(skb)) 712 goto free_skb; 713 714 if (tunnel->collect_md) { 715 erspan_fb_xmit(skb, dev); 716 return NETDEV_TX_OK; 717 } 718 719 if (gre_handle_offloads(skb, false)) 720 goto free_skb; 721 722 if (skb_cow_head(skb, dev->needed_headroom)) 723 goto free_skb; 724 725 if (skb->len > dev->mtu + dev->hard_header_len) { 726 if (pskb_trim(skb, dev->mtu + dev->hard_header_len)) 727 goto free_skb; 728 truncate = true; 729 } 730 731 ip_tunnel_flags_copy(flags, tunnel->parms.o_flags); 732 733 /* Push ERSPAN header */ 734 if (tunnel->erspan_ver == 0) { 735 proto = htons(ETH_P_ERSPAN); 736 __clear_bit(IP_TUNNEL_SEQ_BIT, flags); 737 } else if (tunnel->erspan_ver == 1) { 738 erspan_build_header(skb, ntohl(tunnel->parms.o_key), 739 tunnel->index, 740 truncate, true); 741 proto = htons(ETH_P_ERSPAN); 742 } else if (tunnel->erspan_ver == 2) { 743 erspan_build_header_v2(skb, ntohl(tunnel->parms.o_key), 744 tunnel->dir, tunnel->hwid, 745 truncate, true); 746 proto = htons(ETH_P_ERSPAN2); 747 } else { 748 goto free_skb; 749 } 750 751 __clear_bit(IP_TUNNEL_KEY_BIT, flags); 752 __gre_xmit(skb, dev, &tunnel->parms.iph, proto, flags); 753 return NETDEV_TX_OK; 754 755 free_skb: 756 kfree_skb(skb); 757 DEV_STATS_INC(dev, tx_dropped); 758 return NETDEV_TX_OK; 759 } 760 761 static netdev_tx_t gre_tap_xmit(struct sk_buff *skb, 762 struct net_device *dev) 763 { 764 struct ip_tunnel *tunnel = netdev_priv(dev); 765 IP_TUNNEL_DECLARE_FLAGS(flags); 766 767 if (!pskb_inet_may_pull(skb)) 768 goto free_skb; 769 770 if (tunnel->collect_md) { 771 gre_fb_xmit(skb, dev, htons(ETH_P_TEB)); 772 return NETDEV_TX_OK; 773 } 774 775 ip_tunnel_flags_copy(flags, tunnel->parms.o_flags); 776 777 if (gre_handle_offloads(skb, test_bit(IP_TUNNEL_CSUM_BIT, flags))) 778 goto free_skb; 779 780 if (skb_cow_head(skb, dev->needed_headroom)) 781 goto free_skb; 782 783 __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB), flags); 784 return NETDEV_TX_OK; 785 786 free_skb: 787 kfree_skb(skb); 788 DEV_STATS_INC(dev, tx_dropped); 789 return NETDEV_TX_OK; 790 } 791 792 static void ipgre_link_update(struct net_device *dev, bool set_mtu) 793 { 794 struct ip_tunnel *tunnel = netdev_priv(dev); 795 int len; 796 797 len = tunnel->tun_hlen; 798 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags); 799 len = tunnel->tun_hlen - len; 800 tunnel->hlen = tunnel->hlen + len; 801 802 if (dev->header_ops) 803 dev->hard_header_len += len; 804 else 805 dev->needed_headroom += len; 806 807 if (set_mtu) 808 WRITE_ONCE(dev->mtu, max_t(int, dev->mtu - len, 68)); 809 810 if (test_bit(IP_TUNNEL_SEQ_BIT, tunnel->parms.o_flags) || 811 (test_bit(IP_TUNNEL_CSUM_BIT, tunnel->parms.o_flags) && 812 tunnel->encap.type != TUNNEL_ENCAP_NONE)) { 813 dev->features &= ~NETIF_F_GSO_SOFTWARE; 814 dev->hw_features &= ~NETIF_F_GSO_SOFTWARE; 815 } else { 816 dev->features |= NETIF_F_GSO_SOFTWARE; 817 dev->hw_features |= NETIF_F_GSO_SOFTWARE; 818 } 819 } 820 821 static int ipgre_tunnel_ctl(struct net_device *dev, 822 struct ip_tunnel_parm_kern *p, 823 int cmd) 824 { 825 __be16 i_flags, o_flags; 826 int err; 827 828 if (!ip_tunnel_flags_is_be16_compat(p->i_flags) || 829 !ip_tunnel_flags_is_be16_compat(p->o_flags)) 830 return -EOVERFLOW; 831 832 i_flags = ip_tunnel_flags_to_be16(p->i_flags); 833 o_flags = ip_tunnel_flags_to_be16(p->o_flags); 834 835 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) { 836 if (p->iph.version != 4 || p->iph.protocol != IPPROTO_GRE || 837 p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)) || 838 ((i_flags | o_flags) & (GRE_VERSION | GRE_ROUTING))) 839 return -EINVAL; 840 } 841 842 gre_flags_to_tnl_flags(p->i_flags, i_flags); 843 gre_flags_to_tnl_flags(p->o_flags, o_flags); 844 845 err = ip_tunnel_ctl(dev, p, cmd); 846 if (err) 847 return err; 848 849 if (cmd == SIOCCHGTUNNEL) { 850 struct ip_tunnel *t = netdev_priv(dev); 851 852 ip_tunnel_flags_copy(t->parms.i_flags, p->i_flags); 853 ip_tunnel_flags_copy(t->parms.o_flags, p->o_flags); 854 855 if (strcmp(dev->rtnl_link_ops->kind, "erspan")) 856 ipgre_link_update(dev, true); 857 } 858 859 i_flags = gre_tnl_flags_to_gre_flags(p->i_flags); 860 ip_tunnel_flags_from_be16(p->i_flags, i_flags); 861 o_flags = gre_tnl_flags_to_gre_flags(p->o_flags); 862 ip_tunnel_flags_from_be16(p->o_flags, o_flags); 863 864 return 0; 865 } 866 867 /* Nice toy. Unfortunately, useless in real life :-) 868 It allows to construct virtual multiprotocol broadcast "LAN" 869 over the Internet, provided multicast routing is tuned. 870 871 872 I have no idea was this bicycle invented before me, 873 so that I had to set ARPHRD_IPGRE to a random value. 874 I have an impression, that Cisco could make something similar, 875 but this feature is apparently missing in IOS<=11.2(8). 876 877 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks 878 with broadcast 224.66.66.66. If you have access to mbone, play with me :-) 879 880 ping -t 255 224.66.66.66 881 882 If nobody answers, mbone does not work. 883 884 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255 885 ip addr add 10.66.66.<somewhat>/24 dev Universe 886 ifconfig Universe up 887 ifconfig Universe add fe80::<Your_real_addr>/10 888 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96 889 ftp 10.66.66.66 890 ... 891 ftp fec0:6666:6666::193.233.7.65 892 ... 893 */ 894 static int ipgre_header(struct sk_buff *skb, struct net_device *dev, 895 unsigned short type, 896 const void *daddr, const void *saddr, unsigned int len) 897 { 898 struct ip_tunnel *t = netdev_priv(dev); 899 struct gre_base_hdr *greh; 900 struct iphdr *iph; 901 int needed; 902 903 needed = t->hlen + sizeof(*iph); 904 if (skb_headroom(skb) < needed && 905 pskb_expand_head(skb, HH_DATA_ALIGN(needed - skb_headroom(skb)), 906 0, GFP_ATOMIC)) 907 return -needed; 908 909 iph = skb_push(skb, needed); 910 greh = (struct gre_base_hdr *)(iph+1); 911 greh->flags = gre_tnl_flags_to_gre_flags(t->parms.o_flags); 912 greh->protocol = htons(type); 913 914 memcpy(iph, &t->parms.iph, sizeof(struct iphdr)); 915 916 /* Set the source hardware address. */ 917 if (saddr) 918 memcpy(&iph->saddr, saddr, 4); 919 if (daddr) 920 memcpy(&iph->daddr, daddr, 4); 921 if (iph->daddr) 922 return t->hlen + sizeof(*iph); 923 924 return -(t->hlen + sizeof(*iph)); 925 } 926 927 static int ipgre_header_parse(const struct sk_buff *skb, const struct net_device *dev, 928 unsigned char *haddr) 929 { 930 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb); 931 memcpy(haddr, &iph->saddr, 4); 932 return 4; 933 } 934 935 static const struct header_ops ipgre_header_ops = { 936 .create = ipgre_header, 937 .parse = ipgre_header_parse, 938 }; 939 940 #ifdef CONFIG_NET_IPGRE_BROADCAST 941 static int ipgre_open(struct net_device *dev) 942 { 943 struct ip_tunnel *t = netdev_priv(dev); 944 945 if (ipv4_is_multicast(t->parms.iph.daddr)) { 946 struct flowi4 fl4 = { 947 .flowi4_oif = t->parms.link, 948 .flowi4_dscp = ip4h_dscp(&t->parms.iph), 949 .flowi4_scope = RT_SCOPE_UNIVERSE, 950 .flowi4_proto = IPPROTO_GRE, 951 .saddr = t->parms.iph.saddr, 952 .daddr = t->parms.iph.daddr, 953 .fl4_gre_key = t->parms.o_key, 954 }; 955 struct rtable *rt; 956 957 rt = ip_route_output_key(t->net, &fl4); 958 if (IS_ERR(rt)) 959 return -EADDRNOTAVAIL; 960 dev = rt->dst.dev; 961 ip_rt_put(rt); 962 if (!__in_dev_get_rtnl(dev)) 963 return -EADDRNOTAVAIL; 964 t->mlink = dev->ifindex; 965 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr); 966 } 967 return 0; 968 } 969 970 static int ipgre_close(struct net_device *dev) 971 { 972 struct ip_tunnel *t = netdev_priv(dev); 973 974 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) { 975 struct in_device *in_dev; 976 in_dev = inetdev_by_index(t->net, t->mlink); 977 if (in_dev) 978 ip_mc_dec_group(in_dev, t->parms.iph.daddr); 979 } 980 return 0; 981 } 982 #endif 983 984 static const struct net_device_ops ipgre_netdev_ops = { 985 .ndo_init = ipgre_tunnel_init, 986 .ndo_uninit = ip_tunnel_uninit, 987 #ifdef CONFIG_NET_IPGRE_BROADCAST 988 .ndo_open = ipgre_open, 989 .ndo_stop = ipgre_close, 990 #endif 991 .ndo_start_xmit = ipgre_xmit, 992 .ndo_siocdevprivate = ip_tunnel_siocdevprivate, 993 .ndo_change_mtu = ip_tunnel_change_mtu, 994 .ndo_get_stats64 = dev_get_tstats64, 995 .ndo_get_iflink = ip_tunnel_get_iflink, 996 .ndo_tunnel_ctl = ipgre_tunnel_ctl, 997 }; 998 999 #define GRE_FEATURES (NETIF_F_SG | \ 1000 NETIF_F_FRAGLIST | \ 1001 NETIF_F_HIGHDMA | \ 1002 NETIF_F_HW_CSUM) 1003 1004 static void ipgre_tunnel_setup(struct net_device *dev) 1005 { 1006 dev->netdev_ops = &ipgre_netdev_ops; 1007 dev->type = ARPHRD_IPGRE; 1008 ip_tunnel_setup(dev, ipgre_net_id); 1009 } 1010 1011 static void __gre_tunnel_init(struct net_device *dev) 1012 { 1013 struct ip_tunnel *tunnel; 1014 1015 tunnel = netdev_priv(dev); 1016 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags); 1017 tunnel->parms.iph.protocol = IPPROTO_GRE; 1018 1019 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen; 1020 dev->needed_headroom = tunnel->hlen + sizeof(tunnel->parms.iph); 1021 1022 dev->features |= GRE_FEATURES; 1023 dev->hw_features |= GRE_FEATURES; 1024 1025 dev->lltx = true; 1026 1027 /* TCP offload with GRE SEQ is not supported, nor can we support 2 1028 * levels of outer headers requiring an update. 1029 */ 1030 if (test_bit(IP_TUNNEL_SEQ_BIT, tunnel->parms.o_flags)) 1031 return; 1032 if (test_bit(IP_TUNNEL_CSUM_BIT, tunnel->parms.o_flags) && 1033 tunnel->encap.type != TUNNEL_ENCAP_NONE) 1034 return; 1035 1036 dev->features |= NETIF_F_GSO_SOFTWARE; 1037 dev->hw_features |= NETIF_F_GSO_SOFTWARE; 1038 } 1039 1040 static int ipgre_tunnel_init(struct net_device *dev) 1041 { 1042 struct ip_tunnel *tunnel = netdev_priv(dev); 1043 struct iphdr *iph = &tunnel->parms.iph; 1044 1045 __gre_tunnel_init(dev); 1046 1047 __dev_addr_set(dev, &iph->saddr, 4); 1048 memcpy(dev->broadcast, &iph->daddr, 4); 1049 1050 dev->flags = IFF_NOARP; 1051 netif_keep_dst(dev); 1052 dev->addr_len = 4; 1053 1054 if (iph->daddr && !tunnel->collect_md) { 1055 #ifdef CONFIG_NET_IPGRE_BROADCAST 1056 if (ipv4_is_multicast(iph->daddr)) { 1057 if (!iph->saddr) 1058 return -EINVAL; 1059 dev->flags = IFF_BROADCAST; 1060 dev->header_ops = &ipgre_header_ops; 1061 dev->hard_header_len = tunnel->hlen + sizeof(*iph); 1062 dev->needed_headroom = 0; 1063 } 1064 #endif 1065 } else if (!tunnel->collect_md) { 1066 dev->header_ops = &ipgre_header_ops; 1067 dev->hard_header_len = tunnel->hlen + sizeof(*iph); 1068 dev->needed_headroom = 0; 1069 } 1070 1071 return ip_tunnel_init(dev); 1072 } 1073 1074 static const struct gre_protocol ipgre_protocol = { 1075 .handler = gre_rcv, 1076 .err_handler = gre_err, 1077 }; 1078 1079 static int __net_init ipgre_init_net(struct net *net) 1080 { 1081 return ip_tunnel_init_net(net, ipgre_net_id, &ipgre_link_ops, NULL); 1082 } 1083 1084 static void __net_exit ipgre_exit_rtnl(struct net *net, 1085 struct list_head *dev_to_kill) 1086 { 1087 ip_tunnel_delete_net(net, ipgre_net_id, dev_to_kill); 1088 } 1089 1090 static struct pernet_operations ipgre_net_ops = { 1091 .init = ipgre_init_net, 1092 .exit_rtnl = ipgre_exit_rtnl, 1093 .id = &ipgre_net_id, 1094 .size = sizeof(struct ip_tunnel_net), 1095 }; 1096 1097 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[], 1098 struct netlink_ext_ack *extack) 1099 { 1100 __be16 flags; 1101 1102 if (!data) 1103 return 0; 1104 1105 flags = 0; 1106 if (data[IFLA_GRE_IFLAGS]) 1107 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); 1108 if (data[IFLA_GRE_OFLAGS]) 1109 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); 1110 if (flags & (GRE_VERSION|GRE_ROUTING)) 1111 return -EINVAL; 1112 1113 if (data[IFLA_GRE_COLLECT_METADATA] && 1114 data[IFLA_GRE_ENCAP_TYPE] && 1115 nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]) != TUNNEL_ENCAP_NONE) 1116 return -EINVAL; 1117 1118 return 0; 1119 } 1120 1121 static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[], 1122 struct netlink_ext_ack *extack) 1123 { 1124 __be32 daddr; 1125 1126 if (tb[IFLA_ADDRESS]) { 1127 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) 1128 return -EINVAL; 1129 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) 1130 return -EADDRNOTAVAIL; 1131 } 1132 1133 if (!data) 1134 goto out; 1135 1136 if (data[IFLA_GRE_REMOTE]) { 1137 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4); 1138 if (!daddr) 1139 return -EINVAL; 1140 } 1141 1142 out: 1143 return ipgre_tunnel_validate(tb, data, extack); 1144 } 1145 1146 static int erspan_validate(struct nlattr *tb[], struct nlattr *data[], 1147 struct netlink_ext_ack *extack) 1148 { 1149 __be16 flags = 0; 1150 int ret; 1151 1152 if (!data) 1153 return 0; 1154 1155 ret = ipgre_tap_validate(tb, data, extack); 1156 if (ret) 1157 return ret; 1158 1159 if (data[IFLA_GRE_ERSPAN_VER] && 1160 nla_get_u8(data[IFLA_GRE_ERSPAN_VER]) == 0) 1161 return 0; 1162 1163 /* ERSPAN type II/III should only have GRE sequence and key flag */ 1164 if (data[IFLA_GRE_OFLAGS]) 1165 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); 1166 if (data[IFLA_GRE_IFLAGS]) 1167 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); 1168 if (!data[IFLA_GRE_COLLECT_METADATA] && 1169 flags != (GRE_SEQ | GRE_KEY)) 1170 return -EINVAL; 1171 1172 /* ERSPAN Session ID only has 10-bit. Since we reuse 1173 * 32-bit key field as ID, check it's range. 1174 */ 1175 if (data[IFLA_GRE_IKEY] && 1176 (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK)) 1177 return -EINVAL; 1178 1179 if (data[IFLA_GRE_OKEY] && 1180 (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK)) 1181 return -EINVAL; 1182 1183 return 0; 1184 } 1185 1186 static int ipgre_netlink_parms(struct net_device *dev, 1187 struct nlattr *data[], 1188 struct nlattr *tb[], 1189 struct ip_tunnel_parm_kern *parms, 1190 __u32 *fwmark) 1191 { 1192 struct ip_tunnel *t = netdev_priv(dev); 1193 1194 memset(parms, 0, sizeof(*parms)); 1195 1196 parms->iph.protocol = IPPROTO_GRE; 1197 1198 if (!data) 1199 return 0; 1200 1201 if (data[IFLA_GRE_LINK]) 1202 parms->link = nla_get_u32(data[IFLA_GRE_LINK]); 1203 1204 if (data[IFLA_GRE_IFLAGS]) 1205 gre_flags_to_tnl_flags(parms->i_flags, 1206 nla_get_be16(data[IFLA_GRE_IFLAGS])); 1207 1208 if (data[IFLA_GRE_OFLAGS]) 1209 gre_flags_to_tnl_flags(parms->o_flags, 1210 nla_get_be16(data[IFLA_GRE_OFLAGS])); 1211 1212 if (data[IFLA_GRE_IKEY]) 1213 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]); 1214 1215 if (data[IFLA_GRE_OKEY]) 1216 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]); 1217 1218 if (data[IFLA_GRE_LOCAL]) 1219 parms->iph.saddr = nla_get_in_addr(data[IFLA_GRE_LOCAL]); 1220 1221 if (data[IFLA_GRE_REMOTE]) 1222 parms->iph.daddr = nla_get_in_addr(data[IFLA_GRE_REMOTE]); 1223 1224 if (data[IFLA_GRE_TTL]) 1225 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]); 1226 1227 if (data[IFLA_GRE_TOS]) 1228 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]); 1229 1230 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC])) { 1231 if (t->ignore_df) 1232 return -EINVAL; 1233 parms->iph.frag_off = htons(IP_DF); 1234 } 1235 1236 if (data[IFLA_GRE_COLLECT_METADATA]) { 1237 t->collect_md = true; 1238 if (dev->type == ARPHRD_IPGRE) 1239 dev->type = ARPHRD_NONE; 1240 } 1241 1242 if (data[IFLA_GRE_IGNORE_DF]) { 1243 if (nla_get_u8(data[IFLA_GRE_IGNORE_DF]) 1244 && (parms->iph.frag_off & htons(IP_DF))) 1245 return -EINVAL; 1246 t->ignore_df = !!nla_get_u8(data[IFLA_GRE_IGNORE_DF]); 1247 } 1248 1249 if (data[IFLA_GRE_FWMARK]) 1250 *fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]); 1251 1252 return 0; 1253 } 1254 1255 static int erspan_netlink_parms(struct net_device *dev, 1256 struct nlattr *data[], 1257 struct nlattr *tb[], 1258 struct ip_tunnel_parm_kern *parms, 1259 __u32 *fwmark) 1260 { 1261 struct ip_tunnel *t = netdev_priv(dev); 1262 int err; 1263 1264 err = ipgre_netlink_parms(dev, data, tb, parms, fwmark); 1265 if (err) 1266 return err; 1267 if (!data) 1268 return 0; 1269 1270 if (data[IFLA_GRE_ERSPAN_VER]) { 1271 t->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]); 1272 1273 if (t->erspan_ver > 2) 1274 return -EINVAL; 1275 } 1276 1277 if (t->erspan_ver == 1) { 1278 if (data[IFLA_GRE_ERSPAN_INDEX]) { 1279 t->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]); 1280 if (t->index & ~INDEX_MASK) 1281 return -EINVAL; 1282 } 1283 } else if (t->erspan_ver == 2) { 1284 if (data[IFLA_GRE_ERSPAN_DIR]) { 1285 t->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]); 1286 if (t->dir & ~(DIR_MASK >> DIR_OFFSET)) 1287 return -EINVAL; 1288 } 1289 if (data[IFLA_GRE_ERSPAN_HWID]) { 1290 t->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]); 1291 if (t->hwid & ~(HWID_MASK >> HWID_OFFSET)) 1292 return -EINVAL; 1293 } 1294 } 1295 1296 return 0; 1297 } 1298 1299 /* This function returns true when ENCAP attributes are present in the nl msg */ 1300 static bool ipgre_netlink_encap_parms(struct nlattr *data[], 1301 struct ip_tunnel_encap *ipencap) 1302 { 1303 bool ret = false; 1304 1305 memset(ipencap, 0, sizeof(*ipencap)); 1306 1307 if (!data) 1308 return ret; 1309 1310 if (data[IFLA_GRE_ENCAP_TYPE]) { 1311 ret = true; 1312 ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]); 1313 } 1314 1315 if (data[IFLA_GRE_ENCAP_FLAGS]) { 1316 ret = true; 1317 ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]); 1318 } 1319 1320 if (data[IFLA_GRE_ENCAP_SPORT]) { 1321 ret = true; 1322 ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]); 1323 } 1324 1325 if (data[IFLA_GRE_ENCAP_DPORT]) { 1326 ret = true; 1327 ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]); 1328 } 1329 1330 return ret; 1331 } 1332 1333 static int gre_tap_init(struct net_device *dev) 1334 { 1335 __gre_tunnel_init(dev); 1336 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1337 netif_keep_dst(dev); 1338 1339 return ip_tunnel_init(dev); 1340 } 1341 1342 static const struct net_device_ops gre_tap_netdev_ops = { 1343 .ndo_init = gre_tap_init, 1344 .ndo_uninit = ip_tunnel_uninit, 1345 .ndo_start_xmit = gre_tap_xmit, 1346 .ndo_set_mac_address = eth_mac_addr, 1347 .ndo_validate_addr = eth_validate_addr, 1348 .ndo_change_mtu = ip_tunnel_change_mtu, 1349 .ndo_get_stats64 = dev_get_tstats64, 1350 .ndo_get_iflink = ip_tunnel_get_iflink, 1351 .ndo_fill_metadata_dst = gre_fill_metadata_dst, 1352 }; 1353 1354 static int erspan_tunnel_init(struct net_device *dev) 1355 { 1356 struct ip_tunnel *tunnel = netdev_priv(dev); 1357 1358 if (tunnel->erspan_ver == 0) 1359 tunnel->tun_hlen = 4; /* 4-byte GRE hdr. */ 1360 else 1361 tunnel->tun_hlen = 8; /* 8-byte GRE hdr. */ 1362 1363 tunnel->parms.iph.protocol = IPPROTO_GRE; 1364 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen + 1365 erspan_hdr_len(tunnel->erspan_ver); 1366 1367 dev->features |= GRE_FEATURES; 1368 dev->hw_features |= GRE_FEATURES; 1369 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1370 dev->lltx = true; 1371 netif_keep_dst(dev); 1372 1373 return ip_tunnel_init(dev); 1374 } 1375 1376 static const struct net_device_ops erspan_netdev_ops = { 1377 .ndo_init = erspan_tunnel_init, 1378 .ndo_uninit = ip_tunnel_uninit, 1379 .ndo_start_xmit = erspan_xmit, 1380 .ndo_set_mac_address = eth_mac_addr, 1381 .ndo_validate_addr = eth_validate_addr, 1382 .ndo_change_mtu = ip_tunnel_change_mtu, 1383 .ndo_get_stats64 = dev_get_tstats64, 1384 .ndo_get_iflink = ip_tunnel_get_iflink, 1385 .ndo_fill_metadata_dst = gre_fill_metadata_dst, 1386 }; 1387 1388 static void ipgre_tap_setup(struct net_device *dev) 1389 { 1390 ether_setup(dev); 1391 dev->max_mtu = 0; 1392 dev->netdev_ops = &gre_tap_netdev_ops; 1393 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 1394 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1395 ip_tunnel_setup(dev, gre_tap_net_id); 1396 } 1397 1398 static int 1399 ipgre_newlink_encap_setup(struct net_device *dev, struct nlattr *data[]) 1400 { 1401 struct ip_tunnel_encap ipencap; 1402 1403 if (ipgre_netlink_encap_parms(data, &ipencap)) { 1404 struct ip_tunnel *t = netdev_priv(dev); 1405 int err = ip_tunnel_encap_setup(t, &ipencap); 1406 1407 if (err < 0) 1408 return err; 1409 } 1410 1411 return 0; 1412 } 1413 1414 static int ipgre_newlink(struct net_device *dev, 1415 struct rtnl_newlink_params *params, 1416 struct netlink_ext_ack *extack) 1417 { 1418 struct nlattr **data = params->data; 1419 struct nlattr **tb = params->tb; 1420 struct ip_tunnel_parm_kern p; 1421 __u32 fwmark = 0; 1422 int err; 1423 1424 err = ipgre_newlink_encap_setup(dev, data); 1425 if (err) 1426 return err; 1427 1428 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark); 1429 if (err < 0) 1430 return err; 1431 return ip_tunnel_newlink(params->link_net ? : dev_net(dev), dev, tb, &p, 1432 fwmark); 1433 } 1434 1435 static int erspan_newlink(struct net_device *dev, 1436 struct rtnl_newlink_params *params, 1437 struct netlink_ext_ack *extack) 1438 { 1439 struct nlattr **data = params->data; 1440 struct nlattr **tb = params->tb; 1441 struct ip_tunnel_parm_kern p; 1442 __u32 fwmark = 0; 1443 int err; 1444 1445 err = ipgre_newlink_encap_setup(dev, data); 1446 if (err) 1447 return err; 1448 1449 err = erspan_netlink_parms(dev, data, tb, &p, &fwmark); 1450 if (err) 1451 return err; 1452 return ip_tunnel_newlink(params->link_net ? : dev_net(dev), dev, tb, &p, 1453 fwmark); 1454 } 1455 1456 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[], 1457 struct nlattr *data[], 1458 struct netlink_ext_ack *extack) 1459 { 1460 struct ip_tunnel *t = netdev_priv(dev); 1461 struct ip_tunnel_parm_kern p; 1462 __u32 fwmark = t->fwmark; 1463 int err; 1464 1465 if (!rtnl_dev_link_net_capable(dev, t->net)) 1466 return -EPERM; 1467 1468 if (data && data[IFLA_GRE_COLLECT_METADATA] && !t->collect_md) { 1469 NL_SET_ERR_MSG(extack, 1470 "Enabling collect_md on an existing device is not supported"); 1471 return -EOPNOTSUPP; 1472 } 1473 1474 err = ipgre_newlink_encap_setup(dev, data); 1475 if (err) 1476 return err; 1477 1478 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark); 1479 if (err < 0) 1480 return err; 1481 1482 err = ip_tunnel_changelink(dev, tb, &p, fwmark); 1483 if (err < 0) 1484 return err; 1485 1486 ip_tunnel_flags_copy(t->parms.i_flags, p.i_flags); 1487 ip_tunnel_flags_copy(t->parms.o_flags, p.o_flags); 1488 1489 ipgre_link_update(dev, !tb[IFLA_MTU]); 1490 1491 return 0; 1492 } 1493 1494 static int erspan_changelink(struct net_device *dev, struct nlattr *tb[], 1495 struct nlattr *data[], 1496 struct netlink_ext_ack *extack) 1497 { 1498 struct ip_tunnel *t = netdev_priv(dev); 1499 struct ip_tunnel_parm_kern p; 1500 __u32 fwmark = t->fwmark; 1501 int err; 1502 1503 if (!rtnl_dev_link_net_capable(dev, t->net)) 1504 return -EPERM; 1505 1506 if (data && data[IFLA_GRE_COLLECT_METADATA] && !t->collect_md) { 1507 NL_SET_ERR_MSG(extack, 1508 "Enabling collect_md on an existing device is not supported"); 1509 return -EOPNOTSUPP; 1510 } 1511 1512 err = ipgre_newlink_encap_setup(dev, data); 1513 if (err) 1514 return err; 1515 1516 err = erspan_netlink_parms(dev, data, tb, &p, &fwmark); 1517 if (err < 0) 1518 return err; 1519 1520 err = ip_tunnel_changelink(dev, tb, &p, fwmark); 1521 if (err < 0) 1522 return err; 1523 1524 ip_tunnel_flags_copy(t->parms.i_flags, p.i_flags); 1525 ip_tunnel_flags_copy(t->parms.o_flags, p.o_flags); 1526 1527 return 0; 1528 } 1529 1530 static size_t ipgre_get_size(const struct net_device *dev) 1531 { 1532 return 1533 /* IFLA_GRE_LINK */ 1534 nla_total_size(4) + 1535 /* IFLA_GRE_IFLAGS */ 1536 nla_total_size(2) + 1537 /* IFLA_GRE_OFLAGS */ 1538 nla_total_size(2) + 1539 /* IFLA_GRE_IKEY */ 1540 nla_total_size(4) + 1541 /* IFLA_GRE_OKEY */ 1542 nla_total_size(4) + 1543 /* IFLA_GRE_LOCAL */ 1544 nla_total_size(4) + 1545 /* IFLA_GRE_REMOTE */ 1546 nla_total_size(4) + 1547 /* IFLA_GRE_TTL */ 1548 nla_total_size(1) + 1549 /* IFLA_GRE_TOS */ 1550 nla_total_size(1) + 1551 /* IFLA_GRE_PMTUDISC */ 1552 nla_total_size(1) + 1553 /* IFLA_GRE_ENCAP_TYPE */ 1554 nla_total_size(2) + 1555 /* IFLA_GRE_ENCAP_FLAGS */ 1556 nla_total_size(2) + 1557 /* IFLA_GRE_ENCAP_SPORT */ 1558 nla_total_size(2) + 1559 /* IFLA_GRE_ENCAP_DPORT */ 1560 nla_total_size(2) + 1561 /* IFLA_GRE_COLLECT_METADATA */ 1562 nla_total_size(0) + 1563 /* IFLA_GRE_IGNORE_DF */ 1564 nla_total_size(1) + 1565 /* IFLA_GRE_FWMARK */ 1566 nla_total_size(4) + 1567 /* IFLA_GRE_ERSPAN_INDEX */ 1568 nla_total_size(4) + 1569 /* IFLA_GRE_ERSPAN_VER */ 1570 nla_total_size(1) + 1571 /* IFLA_GRE_ERSPAN_DIR */ 1572 nla_total_size(1) + 1573 /* IFLA_GRE_ERSPAN_HWID */ 1574 nla_total_size(2) + 1575 0; 1576 } 1577 1578 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev) 1579 { 1580 const struct ip_tunnel *t = netdev_priv(dev); 1581 const struct ip_tunnel_parm_kern *p = &t->parms; 1582 IP_TUNNEL_DECLARE_FLAGS(o_flags); 1583 1584 ip_tunnel_flags_copy(o_flags, p->o_flags); 1585 1586 if (t->erspan_ver != 0 && !t->collect_md) 1587 __set_bit(IP_TUNNEL_KEY_BIT, o_flags); 1588 1589 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) || 1590 nla_put_be16(skb, IFLA_GRE_IFLAGS, 1591 gre_tnl_flags_to_gre_flags(p->i_flags)) || 1592 nla_put_be16(skb, IFLA_GRE_OFLAGS, 1593 gre_tnl_flags_to_gre_flags(o_flags)) || 1594 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) || 1595 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) || 1596 nla_put_in_addr(skb, IFLA_GRE_LOCAL, p->iph.saddr) || 1597 nla_put_in_addr(skb, IFLA_GRE_REMOTE, p->iph.daddr) || 1598 nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) || 1599 nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) || 1600 nla_put_u8(skb, IFLA_GRE_PMTUDISC, 1601 !!(p->iph.frag_off & htons(IP_DF))) || 1602 nla_put_u32(skb, IFLA_GRE_FWMARK, t->fwmark)) 1603 goto nla_put_failure; 1604 1605 if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE, 1606 t->encap.type) || 1607 nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT, 1608 t->encap.sport) || 1609 nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT, 1610 t->encap.dport) || 1611 nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS, 1612 t->encap.flags)) 1613 goto nla_put_failure; 1614 1615 if (nla_put_u8(skb, IFLA_GRE_IGNORE_DF, t->ignore_df)) 1616 goto nla_put_failure; 1617 1618 if (t->collect_md) { 1619 if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA)) 1620 goto nla_put_failure; 1621 } 1622 1623 return 0; 1624 1625 nla_put_failure: 1626 return -EMSGSIZE; 1627 } 1628 1629 static int erspan_fill_info(struct sk_buff *skb, const struct net_device *dev) 1630 { 1631 const struct ip_tunnel *t = netdev_priv(dev); 1632 1633 if (t->erspan_ver <= 2) { 1634 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, t->erspan_ver)) 1635 goto nla_put_failure; 1636 1637 if (t->erspan_ver == 1) { 1638 if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, t->index)) 1639 goto nla_put_failure; 1640 } else if (t->erspan_ver == 2) { 1641 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, t->dir)) 1642 goto nla_put_failure; 1643 if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, t->hwid)) 1644 goto nla_put_failure; 1645 } 1646 } 1647 1648 return ipgre_fill_info(skb, dev); 1649 1650 nla_put_failure: 1651 return -EMSGSIZE; 1652 } 1653 1654 static void erspan_setup(struct net_device *dev) 1655 { 1656 struct ip_tunnel *t = netdev_priv(dev); 1657 1658 ether_setup(dev); 1659 dev->max_mtu = 0; 1660 dev->netdev_ops = &erspan_netdev_ops; 1661 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 1662 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1663 ip_tunnel_setup(dev, erspan_net_id); 1664 t->erspan_ver = 1; 1665 } 1666 1667 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = { 1668 [IFLA_GRE_LINK] = { .type = NLA_U32 }, 1669 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 }, 1670 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 }, 1671 [IFLA_GRE_IKEY] = { .type = NLA_U32 }, 1672 [IFLA_GRE_OKEY] = { .type = NLA_U32 }, 1673 [IFLA_GRE_LOCAL] = { .len = sizeof_field(struct iphdr, saddr) }, 1674 [IFLA_GRE_REMOTE] = { .len = sizeof_field(struct iphdr, daddr) }, 1675 [IFLA_GRE_TTL] = { .type = NLA_U8 }, 1676 [IFLA_GRE_TOS] = { .type = NLA_U8 }, 1677 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 }, 1678 [IFLA_GRE_ENCAP_TYPE] = { .type = NLA_U16 }, 1679 [IFLA_GRE_ENCAP_FLAGS] = { .type = NLA_U16 }, 1680 [IFLA_GRE_ENCAP_SPORT] = { .type = NLA_U16 }, 1681 [IFLA_GRE_ENCAP_DPORT] = { .type = NLA_U16 }, 1682 [IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG }, 1683 [IFLA_GRE_IGNORE_DF] = { .type = NLA_U8 }, 1684 [IFLA_GRE_FWMARK] = { .type = NLA_U32 }, 1685 [IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 }, 1686 [IFLA_GRE_ERSPAN_VER] = { .type = NLA_U8 }, 1687 [IFLA_GRE_ERSPAN_DIR] = { .type = NLA_U8 }, 1688 [IFLA_GRE_ERSPAN_HWID] = { .type = NLA_U16 }, 1689 }; 1690 1691 static struct rtnl_link_ops ipgre_link_ops __read_mostly = { 1692 .kind = "gre", 1693 .maxtype = IFLA_GRE_MAX, 1694 .policy = ipgre_policy, 1695 .priv_size = sizeof(struct ip_tunnel), 1696 .setup = ipgre_tunnel_setup, 1697 .validate = ipgre_tunnel_validate, 1698 .newlink = ipgre_newlink, 1699 .changelink = ipgre_changelink, 1700 .dellink = ip_tunnel_dellink, 1701 .get_size = ipgre_get_size, 1702 .fill_info = ipgre_fill_info, 1703 .get_link_net = ip_tunnel_get_link_net, 1704 }; 1705 1706 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = { 1707 .kind = "gretap", 1708 .maxtype = IFLA_GRE_MAX, 1709 .policy = ipgre_policy, 1710 .priv_size = sizeof(struct ip_tunnel), 1711 .setup = ipgre_tap_setup, 1712 .validate = ipgre_tap_validate, 1713 .newlink = ipgre_newlink, 1714 .changelink = ipgre_changelink, 1715 .dellink = ip_tunnel_dellink, 1716 .get_size = ipgre_get_size, 1717 .fill_info = ipgre_fill_info, 1718 .get_link_net = ip_tunnel_get_link_net, 1719 }; 1720 1721 static struct rtnl_link_ops erspan_link_ops __read_mostly = { 1722 .kind = "erspan", 1723 .maxtype = IFLA_GRE_MAX, 1724 .policy = ipgre_policy, 1725 .priv_size = sizeof(struct ip_tunnel), 1726 .setup = erspan_setup, 1727 .validate = erspan_validate, 1728 .newlink = erspan_newlink, 1729 .changelink = erspan_changelink, 1730 .dellink = ip_tunnel_dellink, 1731 .get_size = ipgre_get_size, 1732 .fill_info = erspan_fill_info, 1733 .get_link_net = ip_tunnel_get_link_net, 1734 }; 1735 1736 static int __net_init ipgre_tap_init_net(struct net *net) 1737 { 1738 return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, "gretap0"); 1739 } 1740 1741 static void __net_exit ipgre_tap_exit_rtnl(struct net *net, 1742 struct list_head *dev_to_kill) 1743 { 1744 ip_tunnel_delete_net(net, gre_tap_net_id, dev_to_kill); 1745 } 1746 1747 static struct pernet_operations ipgre_tap_net_ops = { 1748 .init = ipgre_tap_init_net, 1749 .exit_rtnl = ipgre_tap_exit_rtnl, 1750 .id = &gre_tap_net_id, 1751 .size = sizeof(struct ip_tunnel_net), 1752 }; 1753 1754 static int __net_init erspan_init_net(struct net *net) 1755 { 1756 return ip_tunnel_init_net(net, erspan_net_id, 1757 &erspan_link_ops, "erspan0"); 1758 } 1759 1760 static void __net_exit erspan_exit_rtnl(struct net *net, 1761 struct list_head *dev_to_kill) 1762 { 1763 ip_tunnel_delete_net(net, erspan_net_id, dev_to_kill); 1764 } 1765 1766 static struct pernet_operations erspan_net_ops = { 1767 .init = erspan_init_net, 1768 .exit_rtnl = erspan_exit_rtnl, 1769 .id = &erspan_net_id, 1770 .size = sizeof(struct ip_tunnel_net), 1771 }; 1772 1773 static int __init ipgre_init(void) 1774 { 1775 int err; 1776 1777 pr_info("GRE over IPv4 tunneling driver\n"); 1778 1779 err = register_pernet_device(&ipgre_net_ops); 1780 if (err < 0) 1781 return err; 1782 1783 err = register_pernet_device(&ipgre_tap_net_ops); 1784 if (err < 0) 1785 goto pnet_tap_failed; 1786 1787 err = register_pernet_device(&erspan_net_ops); 1788 if (err < 0) 1789 goto pnet_erspan_failed; 1790 1791 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO); 1792 if (err < 0) { 1793 pr_info("%s: can't add protocol\n", __func__); 1794 goto add_proto_failed; 1795 } 1796 1797 err = rtnl_link_register(&ipgre_link_ops); 1798 if (err < 0) 1799 goto rtnl_link_failed; 1800 1801 err = rtnl_link_register(&ipgre_tap_ops); 1802 if (err < 0) 1803 goto tap_ops_failed; 1804 1805 err = rtnl_link_register(&erspan_link_ops); 1806 if (err < 0) 1807 goto erspan_link_failed; 1808 1809 return 0; 1810 1811 erspan_link_failed: 1812 rtnl_link_unregister(&ipgre_tap_ops); 1813 tap_ops_failed: 1814 rtnl_link_unregister(&ipgre_link_ops); 1815 rtnl_link_failed: 1816 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); 1817 add_proto_failed: 1818 unregister_pernet_device(&erspan_net_ops); 1819 pnet_erspan_failed: 1820 unregister_pernet_device(&ipgre_tap_net_ops); 1821 pnet_tap_failed: 1822 unregister_pernet_device(&ipgre_net_ops); 1823 return err; 1824 } 1825 1826 static void __exit ipgre_fini(void) 1827 { 1828 rtnl_link_unregister(&ipgre_tap_ops); 1829 rtnl_link_unregister(&ipgre_link_ops); 1830 rtnl_link_unregister(&erspan_link_ops); 1831 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); 1832 unregister_pernet_device(&ipgre_tap_net_ops); 1833 unregister_pernet_device(&ipgre_net_ops); 1834 unregister_pernet_device(&erspan_net_ops); 1835 } 1836 1837 module_init(ipgre_init); 1838 module_exit(ipgre_fini); 1839 MODULE_DESCRIPTION("IPv4 GRE tunnels over IP library"); 1840 MODULE_LICENSE("GPL"); 1841 MODULE_ALIAS_RTNL_LINK("gre"); 1842 MODULE_ALIAS_RTNL_LINK("gretap"); 1843 MODULE_ALIAS_RTNL_LINK("erspan"); 1844 MODULE_ALIAS_NETDEV("gre0"); 1845 MODULE_ALIAS_NETDEV("gretap0"); 1846 MODULE_ALIAS_NETDEV("erspan0"); 1847