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/sock.h> 32#include <net/ip.h> 33#include <net/icmp.h> 34#include <net/protocol.h> 35#include <net/ip_tunnels.h> 36#include <net/arp.h> 37#include <net/checksum.h> 38#include <net/dsfield.h> 39#include <net/inet_ecn.h> 40#include <net/xfrm.h> 41#include <net/net_namespace.h> 42#include <net/netns/generic.h> 43#include <net/rtnetlink.h> 44#include <net/gre.h> 45#include <net/dst_metadata.h> 46#include <net/erspan.h> 47 48/* 49 Problems & solutions 50 -------------------- 51 52 1. The most important issue is detecting local dead loops. 53 They would cause complete host lockup in transmit, which 54 would be "resolved" by stack overflow or, if queueing is enabled, 55 with infinite looping in net_bh. 56 57 We cannot track such dead loops during route installation, 58 it is infeasible task. The most general solutions would be 59 to keep skb->encapsulation counter (sort of local ttl), 60 and silently drop packet when it expires. It is a good 61 solution, but it supposes maintaining new variable in ALL 62 skb, even if no tunneling is used. 63 64 Current solution: xmit_recursion breaks dead loops. This is a percpu 65 counter, since when we enter the first ndo_xmit(), cpu migration is 66 forbidden. We force an exit if this counter reaches RECURSION_LIMIT 67 68 2. Networking dead loops would not kill routers, but would really 69 kill network. IP hop limit plays role of "t->recursion" in this case, 70 if we copy it from packet being encapsulated to upper header. 71 It is very good solution, but it introduces two problems: 72 73 - Routing protocols, using packets with ttl=1 (OSPF, RIP2), 74 do not work over tunnels. 75 - traceroute does not work. I planned to relay ICMP from tunnel, 76 so that this problem would be solved and traceroute output 77 would even more informative. This idea appeared to be wrong: 78 only Linux complies to rfc1812 now (yes, guys, Linux is the only 79 true router now :-)), all routers (at least, in neighbourhood of mine) 80 return only 8 bytes of payload. It is the end. 81 82 Hence, if we want that OSPF worked or traceroute said something reasonable, 83 we should search for another solution. 84 85 One of them is to parse packet trying to detect inner encapsulation 86 made by our node. It is difficult or even impossible, especially, 87 taking into account fragmentation. TO be short, ttl is not solution at all. 88 89 Current solution: The solution was UNEXPECTEDLY SIMPLE. 90 We force DF flag on tunnels with preconfigured hop limit, 91 that is ALL. :-) Well, it does not remove the problem completely, 92 but exponential growth of network traffic is changed to linear 93 (branches, that exceed pmtu are pruned) and tunnel mtu 94 rapidly degrades to value <68, where looping stops. 95 Yes, it is not good if there exists a router in the loop, 96 which does not force DF, even when encapsulating packets have DF set. 97 But it is not our problem! Nobody could accuse us, we made 98 all that we could make. Even if it is your gated who injected 99 fatal route to network, even if it were you who configured 100 fatal static route: you are innocent. :-) 101 102 Alexey Kuznetsov. 103 */ 104 105static bool log_ecn_error = true; 106module_param(log_ecn_error, bool, 0644); 107MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN"); 108 109static struct rtnl_link_ops ipgre_link_ops __read_mostly; 110static int ipgre_tunnel_init(struct net_device *dev); 111static void erspan_build_header(struct sk_buff *skb, 112 u32 id, u32 index, 113 bool truncate, bool is_ipv4); 114 115static unsigned int ipgre_net_id __read_mostly; 116static unsigned int gre_tap_net_id __read_mostly; 117static unsigned int erspan_net_id __read_mostly; 118 119static int ipgre_err(struct sk_buff *skb, u32 info, 120 const struct tnl_ptk_info *tpi) 121{ 122 123 /* All the routers (except for Linux) return only 124 8 bytes of packet payload. It means, that precise relaying of 125 ICMP in the real Internet is absolutely infeasible. 126 127 Moreover, Cisco "wise men" put GRE key to the third word 128 in GRE header. It makes impossible maintaining even soft 129 state for keyed GRE tunnels with enabled checksum. Tell 130 them "thank you". 131 132 Well, I wonder, rfc1812 was written by Cisco employee, 133 what the hell these idiots break standards established 134 by themselves??? 135 */ 136 struct net *net = dev_net(skb->dev); 137 struct ip_tunnel_net *itn; 138 const struct iphdr *iph; 139 const int type = icmp_hdr(skb)->type; 140 const int code = icmp_hdr(skb)->code; 141 unsigned int data_len = 0; 142 struct ip_tunnel *t; 143 144 if (tpi->proto == htons(ETH_P_TEB)) 145 itn = net_generic(net, gre_tap_net_id); 146 else if (tpi->proto == htons(ETH_P_ERSPAN) || 147 tpi->proto == htons(ETH_P_ERSPAN2)) 148 itn = net_generic(net, erspan_net_id); 149 else 150 itn = net_generic(net, ipgre_net_id); 151 152 iph = (const struct iphdr *)(icmp_hdr(skb) + 1); 153 t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags, 154 iph->daddr, iph->saddr, tpi->key); 155 156 if (!t) 157 return -ENOENT; 158 159 switch (type) { 160 default: 161 case ICMP_PARAMETERPROB: 162 return 0; 163 164 case ICMP_DEST_UNREACH: 165 switch (code) { 166 case ICMP_SR_FAILED: 167 case ICMP_PORT_UNREACH: 168 /* Impossible event. */ 169 return 0; 170 default: 171 /* All others are translated to HOST_UNREACH. 172 rfc2003 contains "deep thoughts" about NET_UNREACH, 173 I believe they are just ether pollution. --ANK 174 */ 175 break; 176 } 177 break; 178 179 case ICMP_TIME_EXCEEDED: 180 if (code != ICMP_EXC_TTL) 181 return 0; 182 data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */ 183 break; 184 185 case ICMP_REDIRECT: 186 break; 187 } 188 189#if IS_ENABLED(CONFIG_IPV6) 190 if (tpi->proto == htons(ETH_P_IPV6) && 191 !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4 + tpi->hdr_len, 192 type, data_len)) 193 return 0; 194#endif 195 196 if (t->parms.iph.daddr == 0 || 197 ipv4_is_multicast(t->parms.iph.daddr)) 198 return 0; 199 200 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 201 return 0; 202 203 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) 204 t->err_count++; 205 else 206 t->err_count = 1; 207 t->err_time = jiffies; 208 209 return 0; 210} 211 212static void gre_err(struct sk_buff *skb, u32 info) 213{ 214 /* All the routers (except for Linux) return only 215 * 8 bytes of packet payload. It means, that precise relaying of 216 * ICMP in the real Internet is absolutely infeasible. 217 * 218 * Moreover, Cisco "wise men" put GRE key to the third word 219 * in GRE header. It makes impossible maintaining even soft 220 * state for keyed 221 * GRE tunnels with enabled checksum. Tell them "thank you". 222 * 223 * Well, I wonder, rfc1812 was written by Cisco employee, 224 * what the hell these idiots break standards established 225 * by themselves??? 226 */ 227 228 const struct iphdr *iph = (struct iphdr *)skb->data; 229 const int type = icmp_hdr(skb)->type; 230 const int code = icmp_hdr(skb)->code; 231 struct tnl_ptk_info tpi; 232 233 if (gre_parse_header(skb, &tpi, NULL, htons(ETH_P_IP), 234 iph->ihl * 4) < 0) 235 return; 236 237 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { 238 ipv4_update_pmtu(skb, dev_net(skb->dev), info, 239 skb->dev->ifindex, IPPROTO_GRE); 240 return; 241 } 242 if (type == ICMP_REDIRECT) { 243 ipv4_redirect(skb, dev_net(skb->dev), skb->dev->ifindex, 244 IPPROTO_GRE); 245 return; 246 } 247 248 ipgre_err(skb, info, &tpi); 249} 250 251static bool is_erspan_type1(int gre_hdr_len) 252{ 253 /* Both ERSPAN type I (version 0) and type II (version 1) use 254 * protocol 0x88BE, but the type I has only 4-byte GRE header, 255 * while type II has 8-byte. 256 */ 257 return gre_hdr_len == 4; 258} 259 260static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi, 261 int gre_hdr_len) 262{ 263 struct net *net = dev_net(skb->dev); 264 struct metadata_dst *tun_dst = NULL; 265 struct erspan_base_hdr *ershdr; 266 struct ip_tunnel_net *itn; 267 struct ip_tunnel *tunnel; 268 const struct iphdr *iph; 269 struct erspan_md2 *md2; 270 int ver; 271 int len; 272 273 itn = net_generic(net, erspan_net_id); 274 iph = ip_hdr(skb); 275 if (is_erspan_type1(gre_hdr_len)) { 276 ver = 0; 277 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, 278 tpi->flags | TUNNEL_NO_KEY, 279 iph->saddr, iph->daddr, 0); 280 } else { 281 ershdr = (struct erspan_base_hdr *)(skb->data + gre_hdr_len); 282 ver = ershdr->ver; 283 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, 284 tpi->flags | TUNNEL_KEY, 285 iph->saddr, iph->daddr, tpi->key); 286 } 287 288 if (tunnel) { 289 if (is_erspan_type1(gre_hdr_len)) 290 len = gre_hdr_len; 291 else 292 len = gre_hdr_len + erspan_hdr_len(ver); 293 294 if (unlikely(!pskb_may_pull(skb, len))) 295 return PACKET_REJECT; 296 297 if (__iptunnel_pull_header(skb, 298 len, 299 htons(ETH_P_TEB), 300 false, false) < 0) 301 goto drop; 302 303 if (tunnel->collect_md) { 304 struct erspan_metadata *pkt_md, *md; 305 struct ip_tunnel_info *info; 306 unsigned char *gh; 307 __be64 tun_id; 308 __be16 flags; 309 310 tpi->flags |= TUNNEL_KEY; 311 flags = tpi->flags; 312 tun_id = key32_to_tunnel_id(tpi->key); 313 314 tun_dst = ip_tun_rx_dst(skb, flags, 315 tun_id, sizeof(*md)); 316 if (!tun_dst) 317 return PACKET_REJECT; 318 319 /* skb can be uncloned in __iptunnel_pull_header, so 320 * old pkt_md is no longer valid and we need to reset 321 * it 322 */ 323 gh = skb_network_header(skb) + 324 skb_network_header_len(skb); 325 pkt_md = (struct erspan_metadata *)(gh + gre_hdr_len + 326 sizeof(*ershdr)); 327 md = ip_tunnel_info_opts(&tun_dst->u.tun_info); 328 md->version = ver; 329 md2 = &md->u.md2; 330 memcpy(md2, pkt_md, ver == 1 ? ERSPAN_V1_MDSIZE : 331 ERSPAN_V2_MDSIZE); 332 333 info = &tun_dst->u.tun_info; 334 info->key.tun_flags |= TUNNEL_ERSPAN_OPT; 335 info->options_len = sizeof(*md); 336 } 337 338 skb_reset_mac_header(skb); 339 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error); 340 return PACKET_RCVD; 341 } 342 return PACKET_REJECT; 343 344drop: 345 kfree_skb(skb); 346 return PACKET_RCVD; 347} 348 349static int __ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi, 350 struct ip_tunnel_net *itn, int hdr_len, bool raw_proto) 351{ 352 struct metadata_dst *tun_dst = NULL; 353 const struct iphdr *iph; 354 struct ip_tunnel *tunnel; 355 356 iph = ip_hdr(skb); 357 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags, 358 iph->saddr, iph->daddr, tpi->key); 359 360 if (tunnel) { 361 const struct iphdr *tnl_params; 362 363 if (__iptunnel_pull_header(skb, hdr_len, tpi->proto, 364 raw_proto, false) < 0) 365 goto drop; 366 367 if (tunnel->dev->type != ARPHRD_NONE) 368 skb_pop_mac_header(skb); 369 else 370 skb_reset_mac_header(skb); 371 372 tnl_params = &tunnel->parms.iph; 373 if (tunnel->collect_md || tnl_params->daddr == 0) { 374 __be16 flags; 375 __be64 tun_id; 376 377 flags = tpi->flags & (TUNNEL_CSUM | TUNNEL_KEY); 378 tun_id = key32_to_tunnel_id(tpi->key); 379 tun_dst = ip_tun_rx_dst(skb, flags, tun_id, 0); 380 if (!tun_dst) 381 return PACKET_REJECT; 382 } 383 384 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error); 385 return PACKET_RCVD; 386 } 387 return PACKET_NEXT; 388 389drop: 390 kfree_skb(skb); 391 return PACKET_RCVD; 392} 393 394static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi, 395 int hdr_len) 396{ 397 struct net *net = dev_net(skb->dev); 398 struct ip_tunnel_net *itn; 399 int res; 400 401 if (tpi->proto == htons(ETH_P_TEB)) 402 itn = net_generic(net, gre_tap_net_id); 403 else 404 itn = net_generic(net, ipgre_net_id); 405 406 res = __ipgre_rcv(skb, tpi, itn, hdr_len, false); 407 if (res == PACKET_NEXT && tpi->proto == htons(ETH_P_TEB)) { 408 /* ipgre tunnels in collect metadata mode should receive 409 * also ETH_P_TEB traffic. 410 */ 411 itn = net_generic(net, ipgre_net_id); 412 res = __ipgre_rcv(skb, tpi, itn, hdr_len, true); 413 } 414 return res; 415} 416 417static int gre_rcv(struct sk_buff *skb) 418{ 419 struct tnl_ptk_info tpi; 420 bool csum_err = false; 421 int hdr_len; 422 423#ifdef CONFIG_NET_IPGRE_BROADCAST 424 if (ipv4_is_multicast(ip_hdr(skb)->daddr)) { 425 /* Looped back packet, drop it! */ 426 if (rt_is_output_route(skb_rtable(skb))) 427 goto drop; 428 } 429#endif 430 431 hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IP), 0); 432 if (hdr_len < 0) 433 goto drop; 434 435 if (unlikely(tpi.proto == htons(ETH_P_ERSPAN) || 436 tpi.proto == htons(ETH_P_ERSPAN2))) { 437 if (erspan_rcv(skb, &tpi, hdr_len) == PACKET_RCVD) 438 return 0; 439 goto out; 440 } 441 442 if (ipgre_rcv(skb, &tpi, hdr_len) == PACKET_RCVD) 443 return 0; 444 445out: 446 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 447drop: 448 kfree_skb(skb); 449 return 0; 450} 451 452static void __gre_xmit(struct sk_buff *skb, struct net_device *dev, 453 const struct iphdr *tnl_params, 454 __be16 proto) 455{ 456 struct ip_tunnel *tunnel = netdev_priv(dev); 457 __be16 flags = tunnel->parms.o_flags; 458 459 /* Push GRE header. */ 460 gre_build_header(skb, tunnel->tun_hlen, 461 flags, proto, tunnel->parms.o_key, 462 (flags & TUNNEL_SEQ) ? htonl(atomic_fetch_inc(&tunnel->o_seqno)) : 0); 463 464 ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol); 465} 466 467static int gre_handle_offloads(struct sk_buff *skb, bool csum) 468{ 469 return iptunnel_handle_offloads(skb, csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE); 470} 471 472static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev, 473 __be16 proto) 474{ 475 struct ip_tunnel *tunnel = netdev_priv(dev); 476 struct ip_tunnel_info *tun_info; 477 const struct ip_tunnel_key *key; 478 int tunnel_hlen; 479 __be16 flags; 480 481 tun_info = skb_tunnel_info(skb); 482 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) || 483 ip_tunnel_info_af(tun_info) != AF_INET)) 484 goto err_free_skb; 485 486 key = &tun_info->key; 487 tunnel_hlen = gre_calc_hlen(key->tun_flags); 488 489 if (skb_cow_head(skb, dev->needed_headroom)) 490 goto err_free_skb; 491 492 /* Push Tunnel header. */ 493 if (gre_handle_offloads(skb, !!(tun_info->key.tun_flags & TUNNEL_CSUM))) 494 goto err_free_skb; 495 496 flags = tun_info->key.tun_flags & 497 (TUNNEL_CSUM | TUNNEL_KEY | TUNNEL_SEQ); 498 gre_build_header(skb, tunnel_hlen, flags, proto, 499 tunnel_id_to_key32(tun_info->key.tun_id), 500 (flags & TUNNEL_SEQ) ? htonl(atomic_fetch_inc(&tunnel->o_seqno)) : 0); 501 502 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen); 503 504 return; 505 506err_free_skb: 507 kfree_skb(skb); 508 dev->stats.tx_dropped++; 509} 510 511static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev) 512{ 513 struct ip_tunnel *tunnel = netdev_priv(dev); 514 struct ip_tunnel_info *tun_info; 515 const struct ip_tunnel_key *key; 516 struct erspan_metadata *md; 517 bool truncate = false; 518 __be16 proto; 519 int tunnel_hlen; 520 int version; 521 int nhoff; 522 523 tun_info = skb_tunnel_info(skb); 524 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) || 525 ip_tunnel_info_af(tun_info) != AF_INET)) 526 goto err_free_skb; 527 528 key = &tun_info->key; 529 if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT)) 530 goto err_free_skb; 531 if (tun_info->options_len < sizeof(*md)) 532 goto err_free_skb; 533 md = ip_tunnel_info_opts(tun_info); 534 535 /* ERSPAN has fixed 8 byte GRE header */ 536 version = md->version; 537 tunnel_hlen = 8 + erspan_hdr_len(version); 538 539 if (skb_cow_head(skb, dev->needed_headroom)) 540 goto err_free_skb; 541 542 if (gre_handle_offloads(skb, false)) 543 goto err_free_skb; 544 545 if (skb->len > dev->mtu + dev->hard_header_len) { 546 pskb_trim(skb, dev->mtu + dev->hard_header_len); 547 truncate = true; 548 } 549 550 nhoff = skb_network_offset(skb); 551 if (skb->protocol == htons(ETH_P_IP) && 552 (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff)) 553 truncate = true; 554 555 if (skb->protocol == htons(ETH_P_IPV6)) { 556 int thoff; 557 558 if (skb_transport_header_was_set(skb)) 559 thoff = skb_transport_offset(skb); 560 else 561 thoff = nhoff + sizeof(struct ipv6hdr); 562 if (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff) 563 truncate = true; 564 } 565 566 if (version == 1) { 567 erspan_build_header(skb, ntohl(tunnel_id_to_key32(key->tun_id)), 568 ntohl(md->u.index), truncate, true); 569 proto = htons(ETH_P_ERSPAN); 570 } else if (version == 2) { 571 erspan_build_header_v2(skb, 572 ntohl(tunnel_id_to_key32(key->tun_id)), 573 md->u.md2.dir, 574 get_hwid(&md->u.md2), 575 truncate, true); 576 proto = htons(ETH_P_ERSPAN2); 577 } else { 578 goto err_free_skb; 579 } 580 581 gre_build_header(skb, 8, TUNNEL_SEQ, 582 proto, 0, htonl(atomic_fetch_inc(&tunnel->o_seqno))); 583 584 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen); 585 586 return; 587 588err_free_skb: 589 kfree_skb(skb); 590 dev->stats.tx_dropped++; 591} 592 593static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb) 594{ 595 struct ip_tunnel_info *info = skb_tunnel_info(skb); 596 const struct ip_tunnel_key *key; 597 struct rtable *rt; 598 struct flowi4 fl4; 599 600 if (ip_tunnel_info_af(info) != AF_INET) 601 return -EINVAL; 602 603 key = &info->key; 604 ip_tunnel_init_flow(&fl4, IPPROTO_GRE, key->u.ipv4.dst, key->u.ipv4.src, 605 tunnel_id_to_key32(key->tun_id), 606 key->tos & ~INET_ECN_MASK, 0, skb->mark, 607 skb_get_hash(skb)); 608 rt = ip_route_output_key(dev_net(dev), &fl4); 609 if (IS_ERR(rt)) 610 return PTR_ERR(rt); 611 612 ip_rt_put(rt); 613 info->key.u.ipv4.src = fl4.saddr; 614 return 0; 615} 616 617static netdev_tx_t ipgre_xmit(struct sk_buff *skb, 618 struct net_device *dev) 619{ 620 struct ip_tunnel *tunnel = netdev_priv(dev); 621 const struct iphdr *tnl_params; 622 623 if (!pskb_inet_may_pull(skb)) 624 goto free_skb; 625 626 if (tunnel->collect_md) { 627 gre_fb_xmit(skb, dev, skb->protocol); 628 return NETDEV_TX_OK; 629 } 630 631 if (dev->header_ops) { 632 int pull_len = tunnel->hlen + sizeof(struct iphdr); 633 634 if (skb_cow_head(skb, 0)) 635 goto free_skb; 636 637 tnl_params = (const struct iphdr *)skb->data; 638 639 if (!pskb_network_may_pull(skb, pull_len)) 640 goto free_skb; 641 642 /* ip_tunnel_xmit() needs skb->data pointing to gre header. */ 643 skb_pull(skb, pull_len); 644 skb_reset_mac_header(skb); 645 646 if (skb->ip_summed == CHECKSUM_PARTIAL && 647 skb_checksum_start(skb) < skb->data) 648 goto free_skb; 649 } else { 650 if (skb_cow_head(skb, dev->needed_headroom)) 651 goto free_skb; 652 653 tnl_params = &tunnel->parms.iph; 654 } 655 656 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM))) 657 goto free_skb; 658 659 __gre_xmit(skb, dev, tnl_params, skb->protocol); 660 return NETDEV_TX_OK; 661 662free_skb: 663 kfree_skb(skb); 664 dev->stats.tx_dropped++; 665 return NETDEV_TX_OK; 666} 667 668static netdev_tx_t erspan_xmit(struct sk_buff *skb, 669 struct net_device *dev) 670{ 671 struct ip_tunnel *tunnel = netdev_priv(dev); 672 bool truncate = false; 673 __be16 proto; 674 675 if (!pskb_inet_may_pull(skb)) 676 goto free_skb; 677 678 if (tunnel->collect_md) { 679 erspan_fb_xmit(skb, dev); 680 return NETDEV_TX_OK; 681 } 682 683 if (gre_handle_offloads(skb, false)) 684 goto free_skb; 685 686 if (skb_cow_head(skb, dev->needed_headroom)) 687 goto free_skb; 688 689 if (skb->len > dev->mtu + dev->hard_header_len) { 690 pskb_trim(skb, dev->mtu + dev->hard_header_len); 691 truncate = true; 692 } 693 694 /* Push ERSPAN header */ 695 if (tunnel->erspan_ver == 0) { 696 proto = htons(ETH_P_ERSPAN); 697 tunnel->parms.o_flags &= ~TUNNEL_SEQ; 698 } else if (tunnel->erspan_ver == 1) { 699 erspan_build_header(skb, ntohl(tunnel->parms.o_key), 700 tunnel->index, 701 truncate, true); 702 proto = htons(ETH_P_ERSPAN); 703 } else if (tunnel->erspan_ver == 2) { 704 erspan_build_header_v2(skb, ntohl(tunnel->parms.o_key), 705 tunnel->dir, tunnel->hwid, 706 truncate, true); 707 proto = htons(ETH_P_ERSPAN2); 708 } else { 709 goto free_skb; 710 } 711 712 tunnel->parms.o_flags &= ~TUNNEL_KEY; 713 __gre_xmit(skb, dev, &tunnel->parms.iph, proto); 714 return NETDEV_TX_OK; 715 716free_skb: 717 kfree_skb(skb); 718 dev->stats.tx_dropped++; 719 return NETDEV_TX_OK; 720} 721 722static netdev_tx_t gre_tap_xmit(struct sk_buff *skb, 723 struct net_device *dev) 724{ 725 struct ip_tunnel *tunnel = netdev_priv(dev); 726 727 if (!pskb_inet_may_pull(skb)) 728 goto free_skb; 729 730 if (tunnel->collect_md) { 731 gre_fb_xmit(skb, dev, htons(ETH_P_TEB)); 732 return NETDEV_TX_OK; 733 } 734 735 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM))) 736 goto free_skb; 737 738 if (skb_cow_head(skb, dev->needed_headroom)) 739 goto free_skb; 740 741 __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB)); 742 return NETDEV_TX_OK; 743 744free_skb: 745 kfree_skb(skb); 746 dev->stats.tx_dropped++; 747 return NETDEV_TX_OK; 748} 749 750static void ipgre_link_update(struct net_device *dev, bool set_mtu) 751{ 752 struct ip_tunnel *tunnel = netdev_priv(dev); 753 int len; 754 755 len = tunnel->tun_hlen; 756 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags); 757 len = tunnel->tun_hlen - len; 758 tunnel->hlen = tunnel->hlen + len; 759 760 if (dev->header_ops) 761 dev->hard_header_len += len; 762 else 763 dev->needed_headroom += len; 764 765 if (set_mtu) 766 dev->mtu = max_t(int, dev->mtu - len, 68); 767 768 if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) { 769 if (!(tunnel->parms.o_flags & TUNNEL_CSUM) || 770 tunnel->encap.type == TUNNEL_ENCAP_NONE) { 771 dev->features |= NETIF_F_GSO_SOFTWARE; 772 dev->hw_features |= NETIF_F_GSO_SOFTWARE; 773 } else { 774 dev->features &= ~NETIF_F_GSO_SOFTWARE; 775 dev->hw_features &= ~NETIF_F_GSO_SOFTWARE; 776 } 777 dev->features |= NETIF_F_LLTX; 778 } else { 779 dev->hw_features &= ~NETIF_F_GSO_SOFTWARE; 780 dev->features &= ~(NETIF_F_LLTX | NETIF_F_GSO_SOFTWARE); 781 } 782} 783 784static int ipgre_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, 785 int cmd) 786{ 787 int err; 788 789 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) { 790 if (p->iph.version != 4 || p->iph.protocol != IPPROTO_GRE || 791 p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)) || 792 ((p->i_flags | p->o_flags) & (GRE_VERSION | GRE_ROUTING))) 793 return -EINVAL; 794 } 795 796 p->i_flags = gre_flags_to_tnl_flags(p->i_flags); 797 p->o_flags = gre_flags_to_tnl_flags(p->o_flags); 798 799 err = ip_tunnel_ctl(dev, p, cmd); 800 if (err) 801 return err; 802 803 if (cmd == SIOCCHGTUNNEL) { 804 struct ip_tunnel *t = netdev_priv(dev); 805 806 t->parms.i_flags = p->i_flags; 807 t->parms.o_flags = p->o_flags; 808 809 if (strcmp(dev->rtnl_link_ops->kind, "erspan")) 810 ipgre_link_update(dev, true); 811 } 812 813 p->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags); 814 p->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags); 815 return 0; 816} 817 818/* Nice toy. Unfortunately, useless in real life :-) 819 It allows to construct virtual multiprotocol broadcast "LAN" 820 over the Internet, provided multicast routing is tuned. 821 822 823 I have no idea was this bicycle invented before me, 824 so that I had to set ARPHRD_IPGRE to a random value. 825 I have an impression, that Cisco could make something similar, 826 but this feature is apparently missing in IOS<=11.2(8). 827 828 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks 829 with broadcast 224.66.66.66. If you have access to mbone, play with me :-) 830 831 ping -t 255 224.66.66.66 832 833 If nobody answers, mbone does not work. 834 835 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255 836 ip addr add 10.66.66.<somewhat>/24 dev Universe 837 ifconfig Universe up 838 ifconfig Universe add fe80::<Your_real_addr>/10 839 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96 840 ftp 10.66.66.66 841 ... 842 ftp fec0:6666:6666::193.233.7.65 843 ... 844 */ 845static int ipgre_header(struct sk_buff *skb, struct net_device *dev, 846 unsigned short type, 847 const void *daddr, const void *saddr, unsigned int len) 848{ 849 struct ip_tunnel *t = netdev_priv(dev); 850 struct iphdr *iph; 851 struct gre_base_hdr *greh; 852 853 iph = skb_push(skb, t->hlen + sizeof(*iph)); 854 greh = (struct gre_base_hdr *)(iph+1); 855 greh->flags = gre_tnl_flags_to_gre_flags(t->parms.o_flags); 856 greh->protocol = htons(type); 857 858 memcpy(iph, &t->parms.iph, sizeof(struct iphdr)); 859 860 /* Set the source hardware address. */ 861 if (saddr) 862 memcpy(&iph->saddr, saddr, 4); 863 if (daddr) 864 memcpy(&iph->daddr, daddr, 4); 865 if (iph->daddr) 866 return t->hlen + sizeof(*iph); 867 868 return -(t->hlen + sizeof(*iph)); 869} 870 871static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr) 872{ 873 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb); 874 memcpy(haddr, &iph->saddr, 4); 875 return 4; 876} 877 878static const struct header_ops ipgre_header_ops = { 879 .create = ipgre_header, 880 .parse = ipgre_header_parse, 881}; 882 883#ifdef CONFIG_NET_IPGRE_BROADCAST 884static int ipgre_open(struct net_device *dev) 885{ 886 struct ip_tunnel *t = netdev_priv(dev); 887 888 if (ipv4_is_multicast(t->parms.iph.daddr)) { 889 struct flowi4 fl4; 890 struct rtable *rt; 891 892 rt = ip_route_output_gre(t->net, &fl4, 893 t->parms.iph.daddr, 894 t->parms.iph.saddr, 895 t->parms.o_key, 896 RT_TOS(t->parms.iph.tos), 897 t->parms.link); 898 if (IS_ERR(rt)) 899 return -EADDRNOTAVAIL; 900 dev = rt->dst.dev; 901 ip_rt_put(rt); 902 if (!__in_dev_get_rtnl(dev)) 903 return -EADDRNOTAVAIL; 904 t->mlink = dev->ifindex; 905 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr); 906 } 907 return 0; 908} 909 910static int ipgre_close(struct net_device *dev) 911{ 912 struct ip_tunnel *t = netdev_priv(dev); 913 914 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) { 915 struct in_device *in_dev; 916 in_dev = inetdev_by_index(t->net, t->mlink); 917 if (in_dev) 918 ip_mc_dec_group(in_dev, t->parms.iph.daddr); 919 } 920 return 0; 921} 922#endif 923 924static const struct net_device_ops ipgre_netdev_ops = { 925 .ndo_init = ipgre_tunnel_init, 926 .ndo_uninit = ip_tunnel_uninit, 927#ifdef CONFIG_NET_IPGRE_BROADCAST 928 .ndo_open = ipgre_open, 929 .ndo_stop = ipgre_close, 930#endif 931 .ndo_start_xmit = ipgre_xmit, 932 .ndo_do_ioctl = ip_tunnel_ioctl, 933 .ndo_change_mtu = ip_tunnel_change_mtu, 934 .ndo_get_stats64 = ip_tunnel_get_stats64, 935 .ndo_get_iflink = ip_tunnel_get_iflink, 936 .ndo_tunnel_ctl = ipgre_tunnel_ctl, 937}; 938 939#define GRE_FEATURES (NETIF_F_SG | \ 940 NETIF_F_FRAGLIST | \ 941 NETIF_F_HIGHDMA | \ 942 NETIF_F_HW_CSUM) 943 944static void ipgre_tunnel_setup(struct net_device *dev) 945{ 946 dev->netdev_ops = &ipgre_netdev_ops; 947 dev->type = ARPHRD_IPGRE; 948 ip_tunnel_setup(dev, ipgre_net_id); 949} 950 951static void __gre_tunnel_init(struct net_device *dev) 952{ 953 struct ip_tunnel *tunnel; 954 955 tunnel = netdev_priv(dev); 956 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags); 957 tunnel->parms.iph.protocol = IPPROTO_GRE; 958 959 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen; 960 dev->needed_headroom = tunnel->hlen + sizeof(tunnel->parms.iph); 961 962 dev->features |= GRE_FEATURES; 963 dev->hw_features |= GRE_FEATURES; 964 965 if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) { 966 /* TCP offload with GRE SEQ is not supported, nor 967 * can we support 2 levels of outer headers requiring 968 * an update. 969 */ 970 if (!(tunnel->parms.o_flags & TUNNEL_CSUM) || 971 (tunnel->encap.type == TUNNEL_ENCAP_NONE)) { 972 dev->features |= NETIF_F_GSO_SOFTWARE; 973 dev->hw_features |= NETIF_F_GSO_SOFTWARE; 974 } 975 976 /* Can use a lockless transmit, unless we generate 977 * output sequences 978 */ 979 dev->features |= NETIF_F_LLTX; 980 } 981} 982 983static int ipgre_tunnel_init(struct net_device *dev) 984{ 985 struct ip_tunnel *tunnel = netdev_priv(dev); 986 struct iphdr *iph = &tunnel->parms.iph; 987 988 __gre_tunnel_init(dev); 989 990 memcpy(dev->dev_addr, &iph->saddr, 4); 991 memcpy(dev->broadcast, &iph->daddr, 4); 992 993 dev->flags = IFF_NOARP; 994 netif_keep_dst(dev); 995 dev->addr_len = 4; 996 997 if (iph->daddr && !tunnel->collect_md) { 998#ifdef CONFIG_NET_IPGRE_BROADCAST 999 if (ipv4_is_multicast(iph->daddr)) { 1000 if (!iph->saddr) 1001 return -EINVAL; 1002 dev->flags = IFF_BROADCAST; 1003 dev->header_ops = &ipgre_header_ops; 1004 dev->hard_header_len = tunnel->hlen + sizeof(*iph); 1005 dev->needed_headroom = 0; 1006 } 1007#endif 1008 } else if (!tunnel->collect_md) { 1009 dev->header_ops = &ipgre_header_ops; 1010 dev->hard_header_len = tunnel->hlen + sizeof(*iph); 1011 dev->needed_headroom = 0; 1012 } 1013 1014 return ip_tunnel_init(dev); 1015} 1016 1017static const struct gre_protocol ipgre_protocol = { 1018 .handler = gre_rcv, 1019 .err_handler = gre_err, 1020}; 1021 1022static int __net_init ipgre_init_net(struct net *net) 1023{ 1024 return ip_tunnel_init_net(net, ipgre_net_id, &ipgre_link_ops, NULL); 1025} 1026 1027static void __net_exit ipgre_exit_batch_net(struct list_head *list_net) 1028{ 1029 ip_tunnel_delete_nets(list_net, ipgre_net_id, &ipgre_link_ops); 1030} 1031 1032static struct pernet_operations ipgre_net_ops = { 1033 .init = ipgre_init_net, 1034 .exit_batch = ipgre_exit_batch_net, 1035 .id = &ipgre_net_id, 1036 .size = sizeof(struct ip_tunnel_net), 1037}; 1038 1039static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[], 1040 struct netlink_ext_ack *extack) 1041{ 1042 __be16 flags; 1043 1044 if (!data) 1045 return 0; 1046 1047 flags = 0; 1048 if (data[IFLA_GRE_IFLAGS]) 1049 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); 1050 if (data[IFLA_GRE_OFLAGS]) 1051 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); 1052 if (flags & (GRE_VERSION|GRE_ROUTING)) 1053 return -EINVAL; 1054 1055 if (data[IFLA_GRE_COLLECT_METADATA] && 1056 data[IFLA_GRE_ENCAP_TYPE] && 1057 nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]) != TUNNEL_ENCAP_NONE) 1058 return -EINVAL; 1059 1060 return 0; 1061} 1062 1063static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[], 1064 struct netlink_ext_ack *extack) 1065{ 1066 __be32 daddr; 1067 1068 if (tb[IFLA_ADDRESS]) { 1069 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) 1070 return -EINVAL; 1071 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) 1072 return -EADDRNOTAVAIL; 1073 } 1074 1075 if (!data) 1076 goto out; 1077 1078 if (data[IFLA_GRE_REMOTE]) { 1079 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4); 1080 if (!daddr) 1081 return -EINVAL; 1082 } 1083 1084out: 1085 return ipgre_tunnel_validate(tb, data, extack); 1086} 1087 1088static int erspan_validate(struct nlattr *tb[], struct nlattr *data[], 1089 struct netlink_ext_ack *extack) 1090{ 1091 __be16 flags = 0; 1092 int ret; 1093 1094 if (!data) 1095 return 0; 1096 1097 ret = ipgre_tap_validate(tb, data, extack); 1098 if (ret) 1099 return ret; 1100 1101 if (data[IFLA_GRE_ERSPAN_VER] && 1102 nla_get_u8(data[IFLA_GRE_ERSPAN_VER]) == 0) 1103 return 0; 1104 1105 /* ERSPAN type II/III should only have GRE sequence and key flag */ 1106 if (data[IFLA_GRE_OFLAGS]) 1107 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); 1108 if (data[IFLA_GRE_IFLAGS]) 1109 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); 1110 if (!data[IFLA_GRE_COLLECT_METADATA] && 1111 flags != (GRE_SEQ | GRE_KEY)) 1112 return -EINVAL; 1113 1114 /* ERSPAN Session ID only has 10-bit. Since we reuse 1115 * 32-bit key field as ID, check it's range. 1116 */ 1117 if (data[IFLA_GRE_IKEY] && 1118 (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK)) 1119 return -EINVAL; 1120 1121 if (data[IFLA_GRE_OKEY] && 1122 (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK)) 1123 return -EINVAL; 1124 1125 return 0; 1126} 1127 1128static int ipgre_netlink_parms(struct net_device *dev, 1129 struct nlattr *data[], 1130 struct nlattr *tb[], 1131 struct ip_tunnel_parm *parms, 1132 __u32 *fwmark) 1133{ 1134 struct ip_tunnel *t = netdev_priv(dev); 1135 1136 memset(parms, 0, sizeof(*parms)); 1137 1138 parms->iph.protocol = IPPROTO_GRE; 1139 1140 if (!data) 1141 return 0; 1142 1143 if (data[IFLA_GRE_LINK]) 1144 parms->link = nla_get_u32(data[IFLA_GRE_LINK]); 1145 1146 if (data[IFLA_GRE_IFLAGS]) 1147 parms->i_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_IFLAGS])); 1148 1149 if (data[IFLA_GRE_OFLAGS]) 1150 parms->o_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_OFLAGS])); 1151 1152 if (data[IFLA_GRE_IKEY]) 1153 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]); 1154 1155 if (data[IFLA_GRE_OKEY]) 1156 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]); 1157 1158 if (data[IFLA_GRE_LOCAL]) 1159 parms->iph.saddr = nla_get_in_addr(data[IFLA_GRE_LOCAL]); 1160 1161 if (data[IFLA_GRE_REMOTE]) 1162 parms->iph.daddr = nla_get_in_addr(data[IFLA_GRE_REMOTE]); 1163 1164 if (data[IFLA_GRE_TTL]) 1165 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]); 1166 1167 if (data[IFLA_GRE_TOS]) 1168 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]); 1169 1170 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC])) { 1171 if (t->ignore_df) 1172 return -EINVAL; 1173 parms->iph.frag_off = htons(IP_DF); 1174 } 1175 1176 if (data[IFLA_GRE_COLLECT_METADATA]) { 1177 t->collect_md = true; 1178 if (dev->type == ARPHRD_IPGRE) 1179 dev->type = ARPHRD_NONE; 1180 } 1181 1182 if (data[IFLA_GRE_IGNORE_DF]) { 1183 if (nla_get_u8(data[IFLA_GRE_IGNORE_DF]) 1184 && (parms->iph.frag_off & htons(IP_DF))) 1185 return -EINVAL; 1186 t->ignore_df = !!nla_get_u8(data[IFLA_GRE_IGNORE_DF]); 1187 } 1188 1189 if (data[IFLA_GRE_FWMARK]) 1190 *fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]); 1191 1192 return 0; 1193} 1194 1195static int erspan_netlink_parms(struct net_device *dev, 1196 struct nlattr *data[], 1197 struct nlattr *tb[], 1198 struct ip_tunnel_parm *parms, 1199 __u32 *fwmark) 1200{ 1201 struct ip_tunnel *t = netdev_priv(dev); 1202 int err; 1203 1204 err = ipgre_netlink_parms(dev, data, tb, parms, fwmark); 1205 if (err) 1206 return err; 1207 if (!data) 1208 return 0; 1209 1210 if (data[IFLA_GRE_ERSPAN_VER]) { 1211 t->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]); 1212 1213 if (t->erspan_ver > 2) 1214 return -EINVAL; 1215 } 1216 1217 if (t->erspan_ver == 1) { 1218 if (data[IFLA_GRE_ERSPAN_INDEX]) { 1219 t->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]); 1220 if (t->index & ~INDEX_MASK) 1221 return -EINVAL; 1222 } 1223 } else if (t->erspan_ver == 2) { 1224 if (data[IFLA_GRE_ERSPAN_DIR]) { 1225 t->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]); 1226 if (t->dir & ~(DIR_MASK >> DIR_OFFSET)) 1227 return -EINVAL; 1228 } 1229 if (data[IFLA_GRE_ERSPAN_HWID]) { 1230 t->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]); 1231 if (t->hwid & ~(HWID_MASK >> HWID_OFFSET)) 1232 return -EINVAL; 1233 } 1234 } 1235 1236 return 0; 1237} 1238 1239/* This function returns true when ENCAP attributes are present in the nl msg */ 1240static bool ipgre_netlink_encap_parms(struct nlattr *data[], 1241 struct ip_tunnel_encap *ipencap) 1242{ 1243 bool ret = false; 1244 1245 memset(ipencap, 0, sizeof(*ipencap)); 1246 1247 if (!data) 1248 return ret; 1249 1250 if (data[IFLA_GRE_ENCAP_TYPE]) { 1251 ret = true; 1252 ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]); 1253 } 1254 1255 if (data[IFLA_GRE_ENCAP_FLAGS]) { 1256 ret = true; 1257 ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]); 1258 } 1259 1260 if (data[IFLA_GRE_ENCAP_SPORT]) { 1261 ret = true; 1262 ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]); 1263 } 1264 1265 if (data[IFLA_GRE_ENCAP_DPORT]) { 1266 ret = true; 1267 ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]); 1268 } 1269 1270 return ret; 1271} 1272 1273static int gre_tap_init(struct net_device *dev) 1274{ 1275 __gre_tunnel_init(dev); 1276 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1277 netif_keep_dst(dev); 1278 1279 return ip_tunnel_init(dev); 1280} 1281 1282static const struct net_device_ops gre_tap_netdev_ops = { 1283 .ndo_init = gre_tap_init, 1284 .ndo_uninit = ip_tunnel_uninit, 1285 .ndo_start_xmit = gre_tap_xmit, 1286 .ndo_set_mac_address = eth_mac_addr, 1287 .ndo_validate_addr = eth_validate_addr, 1288 .ndo_change_mtu = ip_tunnel_change_mtu, 1289 .ndo_get_stats64 = ip_tunnel_get_stats64, 1290 .ndo_get_iflink = ip_tunnel_get_iflink, 1291 .ndo_fill_metadata_dst = gre_fill_metadata_dst, 1292}; 1293 1294static int erspan_tunnel_init(struct net_device *dev) 1295{ 1296 struct ip_tunnel *tunnel = netdev_priv(dev); 1297 1298 if (tunnel->erspan_ver == 0) 1299 tunnel->tun_hlen = 4; /* 4-byte GRE hdr. */ 1300 else 1301 tunnel->tun_hlen = 8; /* 8-byte GRE hdr. */ 1302 1303 tunnel->parms.iph.protocol = IPPROTO_GRE; 1304 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen + 1305 erspan_hdr_len(tunnel->erspan_ver); 1306 1307 dev->features |= GRE_FEATURES; 1308 dev->hw_features |= GRE_FEATURES; 1309 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1310 netif_keep_dst(dev); 1311 1312 return ip_tunnel_init(dev); 1313} 1314 1315static const struct net_device_ops erspan_netdev_ops = { 1316 .ndo_init = erspan_tunnel_init, 1317 .ndo_uninit = ip_tunnel_uninit, 1318 .ndo_start_xmit = erspan_xmit, 1319 .ndo_set_mac_address = eth_mac_addr, 1320 .ndo_validate_addr = eth_validate_addr, 1321 .ndo_change_mtu = ip_tunnel_change_mtu, 1322 .ndo_get_stats64 = ip_tunnel_get_stats64, 1323 .ndo_get_iflink = ip_tunnel_get_iflink, 1324 .ndo_fill_metadata_dst = gre_fill_metadata_dst, 1325}; 1326 1327static void ipgre_tap_setup(struct net_device *dev) 1328{ 1329 ether_setup(dev); 1330 dev->max_mtu = 0; 1331 dev->netdev_ops = &gre_tap_netdev_ops; 1332 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 1333 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1334 ip_tunnel_setup(dev, gre_tap_net_id); 1335} 1336 1337static int 1338ipgre_newlink_encap_setup(struct net_device *dev, struct nlattr *data[]) 1339{ 1340 struct ip_tunnel_encap ipencap; 1341 1342 if (ipgre_netlink_encap_parms(data, &ipencap)) { 1343 struct ip_tunnel *t = netdev_priv(dev); 1344 int err = ip_tunnel_encap_setup(t, &ipencap); 1345 1346 if (err < 0) 1347 return err; 1348 } 1349 1350 return 0; 1351} 1352 1353static int ipgre_newlink(struct net *src_net, struct net_device *dev, 1354 struct nlattr *tb[], struct nlattr *data[], 1355 struct netlink_ext_ack *extack) 1356{ 1357 struct ip_tunnel_parm p; 1358 __u32 fwmark = 0; 1359 int err; 1360 1361 err = ipgre_newlink_encap_setup(dev, data); 1362 if (err) 1363 return err; 1364 1365 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark); 1366 if (err < 0) 1367 return err; 1368 return ip_tunnel_newlink(dev, tb, &p, fwmark); 1369} 1370 1371static int erspan_newlink(struct net *src_net, struct net_device *dev, 1372 struct nlattr *tb[], struct nlattr *data[], 1373 struct netlink_ext_ack *extack) 1374{ 1375 struct ip_tunnel_parm p; 1376 __u32 fwmark = 0; 1377 int err; 1378 1379 err = ipgre_newlink_encap_setup(dev, data); 1380 if (err) 1381 return err; 1382 1383 err = erspan_netlink_parms(dev, data, tb, &p, &fwmark); 1384 if (err) 1385 return err; 1386 return ip_tunnel_newlink(dev, tb, &p, fwmark); 1387} 1388 1389static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[], 1390 struct nlattr *data[], 1391 struct netlink_ext_ack *extack) 1392{ 1393 struct ip_tunnel *t = netdev_priv(dev); 1394 __u32 fwmark = t->fwmark; 1395 struct ip_tunnel_parm p; 1396 int err; 1397 1398 err = ipgre_newlink_encap_setup(dev, data); 1399 if (err) 1400 return err; 1401 1402 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark); 1403 if (err < 0) 1404 return err; 1405 1406 err = ip_tunnel_changelink(dev, tb, &p, fwmark); 1407 if (err < 0) 1408 return err; 1409 1410 t->parms.i_flags = p.i_flags; 1411 t->parms.o_flags = p.o_flags; 1412 1413 ipgre_link_update(dev, !tb[IFLA_MTU]); 1414 1415 return 0; 1416} 1417 1418static int erspan_changelink(struct net_device *dev, struct nlattr *tb[], 1419 struct nlattr *data[], 1420 struct netlink_ext_ack *extack) 1421{ 1422 struct ip_tunnel *t = netdev_priv(dev); 1423 __u32 fwmark = t->fwmark; 1424 struct ip_tunnel_parm p; 1425 int err; 1426 1427 err = ipgre_newlink_encap_setup(dev, data); 1428 if (err) 1429 return err; 1430 1431 err = erspan_netlink_parms(dev, data, tb, &p, &fwmark); 1432 if (err < 0) 1433 return err; 1434 1435 err = ip_tunnel_changelink(dev, tb, &p, fwmark); 1436 if (err < 0) 1437 return err; 1438 1439 t->parms.i_flags = p.i_flags; 1440 t->parms.o_flags = p.o_flags; 1441 1442 return 0; 1443} 1444 1445static size_t ipgre_get_size(const struct net_device *dev) 1446{ 1447 return 1448 /* IFLA_GRE_LINK */ 1449 nla_total_size(4) + 1450 /* IFLA_GRE_IFLAGS */ 1451 nla_total_size(2) + 1452 /* IFLA_GRE_OFLAGS */ 1453 nla_total_size(2) + 1454 /* IFLA_GRE_IKEY */ 1455 nla_total_size(4) + 1456 /* IFLA_GRE_OKEY */ 1457 nla_total_size(4) + 1458 /* IFLA_GRE_LOCAL */ 1459 nla_total_size(4) + 1460 /* IFLA_GRE_REMOTE */ 1461 nla_total_size(4) + 1462 /* IFLA_GRE_TTL */ 1463 nla_total_size(1) + 1464 /* IFLA_GRE_TOS */ 1465 nla_total_size(1) + 1466 /* IFLA_GRE_PMTUDISC */ 1467 nla_total_size(1) + 1468 /* IFLA_GRE_ENCAP_TYPE */ 1469 nla_total_size(2) + 1470 /* IFLA_GRE_ENCAP_FLAGS */ 1471 nla_total_size(2) + 1472 /* IFLA_GRE_ENCAP_SPORT */ 1473 nla_total_size(2) + 1474 /* IFLA_GRE_ENCAP_DPORT */ 1475 nla_total_size(2) + 1476 /* IFLA_GRE_COLLECT_METADATA */ 1477 nla_total_size(0) + 1478 /* IFLA_GRE_IGNORE_DF */ 1479 nla_total_size(1) + 1480 /* IFLA_GRE_FWMARK */ 1481 nla_total_size(4) + 1482 /* IFLA_GRE_ERSPAN_INDEX */ 1483 nla_total_size(4) + 1484 /* IFLA_GRE_ERSPAN_VER */ 1485 nla_total_size(1) + 1486 /* IFLA_GRE_ERSPAN_DIR */ 1487 nla_total_size(1) + 1488 /* IFLA_GRE_ERSPAN_HWID */ 1489 nla_total_size(2) + 1490 0; 1491} 1492 1493static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev) 1494{ 1495 struct ip_tunnel *t = netdev_priv(dev); 1496 struct ip_tunnel_parm *p = &t->parms; 1497 __be16 o_flags = p->o_flags; 1498 1499 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) || 1500 nla_put_be16(skb, IFLA_GRE_IFLAGS, 1501 gre_tnl_flags_to_gre_flags(p->i_flags)) || 1502 nla_put_be16(skb, IFLA_GRE_OFLAGS, 1503 gre_tnl_flags_to_gre_flags(o_flags)) || 1504 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) || 1505 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) || 1506 nla_put_in_addr(skb, IFLA_GRE_LOCAL, p->iph.saddr) || 1507 nla_put_in_addr(skb, IFLA_GRE_REMOTE, p->iph.daddr) || 1508 nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) || 1509 nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) || 1510 nla_put_u8(skb, IFLA_GRE_PMTUDISC, 1511 !!(p->iph.frag_off & htons(IP_DF))) || 1512 nla_put_u32(skb, IFLA_GRE_FWMARK, t->fwmark)) 1513 goto nla_put_failure; 1514 1515 if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE, 1516 t->encap.type) || 1517 nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT, 1518 t->encap.sport) || 1519 nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT, 1520 t->encap.dport) || 1521 nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS, 1522 t->encap.flags)) 1523 goto nla_put_failure; 1524 1525 if (nla_put_u8(skb, IFLA_GRE_IGNORE_DF, t->ignore_df)) 1526 goto nla_put_failure; 1527 1528 if (t->collect_md) { 1529 if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA)) 1530 goto nla_put_failure; 1531 } 1532 1533 return 0; 1534 1535nla_put_failure: 1536 return -EMSGSIZE; 1537} 1538 1539static int erspan_fill_info(struct sk_buff *skb, const struct net_device *dev) 1540{ 1541 struct ip_tunnel *t = netdev_priv(dev); 1542 1543 if (t->erspan_ver <= 2) { 1544 if (t->erspan_ver != 0 && !t->collect_md) 1545 t->parms.o_flags |= TUNNEL_KEY; 1546 1547 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, t->erspan_ver)) 1548 goto nla_put_failure; 1549 1550 if (t->erspan_ver == 1) { 1551 if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, t->index)) 1552 goto nla_put_failure; 1553 } else if (t->erspan_ver == 2) { 1554 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, t->dir)) 1555 goto nla_put_failure; 1556 if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, t->hwid)) 1557 goto nla_put_failure; 1558 } 1559 } 1560 1561 return ipgre_fill_info(skb, dev); 1562 1563nla_put_failure: 1564 return -EMSGSIZE; 1565} 1566 1567static void erspan_setup(struct net_device *dev) 1568{ 1569 struct ip_tunnel *t = netdev_priv(dev); 1570 1571 ether_setup(dev); 1572 dev->max_mtu = 0; 1573 dev->netdev_ops = &erspan_netdev_ops; 1574 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 1575 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1576 ip_tunnel_setup(dev, erspan_net_id); 1577 t->erspan_ver = 1; 1578} 1579 1580static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = { 1581 [IFLA_GRE_LINK] = { .type = NLA_U32 }, 1582 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 }, 1583 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 }, 1584 [IFLA_GRE_IKEY] = { .type = NLA_U32 }, 1585 [IFLA_GRE_OKEY] = { .type = NLA_U32 }, 1586 [IFLA_GRE_LOCAL] = { .len = sizeof_field(struct iphdr, saddr) }, 1587 [IFLA_GRE_REMOTE] = { .len = sizeof_field(struct iphdr, daddr) }, 1588 [IFLA_GRE_TTL] = { .type = NLA_U8 }, 1589 [IFLA_GRE_TOS] = { .type = NLA_U8 }, 1590 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 }, 1591 [IFLA_GRE_ENCAP_TYPE] = { .type = NLA_U16 }, 1592 [IFLA_GRE_ENCAP_FLAGS] = { .type = NLA_U16 }, 1593 [IFLA_GRE_ENCAP_SPORT] = { .type = NLA_U16 }, 1594 [IFLA_GRE_ENCAP_DPORT] = { .type = NLA_U16 }, 1595 [IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG }, 1596 [IFLA_GRE_IGNORE_DF] = { .type = NLA_U8 }, 1597 [IFLA_GRE_FWMARK] = { .type = NLA_U32 }, 1598 [IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 }, 1599 [IFLA_GRE_ERSPAN_VER] = { .type = NLA_U8 }, 1600 [IFLA_GRE_ERSPAN_DIR] = { .type = NLA_U8 }, 1601 [IFLA_GRE_ERSPAN_HWID] = { .type = NLA_U16 }, 1602}; 1603 1604static struct rtnl_link_ops ipgre_link_ops __read_mostly = { 1605 .kind = "gre", 1606 .maxtype = IFLA_GRE_MAX, 1607 .policy = ipgre_policy, 1608 .priv_size = sizeof(struct ip_tunnel), 1609 .setup = ipgre_tunnel_setup, 1610 .validate = ipgre_tunnel_validate, 1611 .newlink = ipgre_newlink, 1612 .changelink = ipgre_changelink, 1613 .dellink = ip_tunnel_dellink, 1614 .get_size = ipgre_get_size, 1615 .fill_info = ipgre_fill_info, 1616 .get_link_net = ip_tunnel_get_link_net, 1617}; 1618 1619static struct rtnl_link_ops ipgre_tap_ops __read_mostly = { 1620 .kind = "gretap", 1621 .maxtype = IFLA_GRE_MAX, 1622 .policy = ipgre_policy, 1623 .priv_size = sizeof(struct ip_tunnel), 1624 .setup = ipgre_tap_setup, 1625 .validate = ipgre_tap_validate, 1626 .newlink = ipgre_newlink, 1627 .changelink = ipgre_changelink, 1628 .dellink = ip_tunnel_dellink, 1629 .get_size = ipgre_get_size, 1630 .fill_info = ipgre_fill_info, 1631 .get_link_net = ip_tunnel_get_link_net, 1632}; 1633 1634static struct rtnl_link_ops erspan_link_ops __read_mostly = { 1635 .kind = "erspan", 1636 .maxtype = IFLA_GRE_MAX, 1637 .policy = ipgre_policy, 1638 .priv_size = sizeof(struct ip_tunnel), 1639 .setup = erspan_setup, 1640 .validate = erspan_validate, 1641 .newlink = erspan_newlink, 1642 .changelink = erspan_changelink, 1643 .dellink = ip_tunnel_dellink, 1644 .get_size = ipgre_get_size, 1645 .fill_info = erspan_fill_info, 1646 .get_link_net = ip_tunnel_get_link_net, 1647}; 1648 1649struct net_device *gretap_fb_dev_create(struct net *net, const char *name, 1650 u8 name_assign_type) 1651{ 1652 struct nlattr *tb[IFLA_MAX + 1]; 1653 struct net_device *dev; 1654 LIST_HEAD(list_kill); 1655 struct ip_tunnel *t; 1656 int err; 1657 1658 memset(&tb, 0, sizeof(tb)); 1659 1660 dev = rtnl_create_link(net, name, name_assign_type, 1661 &ipgre_tap_ops, tb, NULL); 1662 if (IS_ERR(dev)) 1663 return dev; 1664 1665 /* Configure flow based GRE device. */ 1666 t = netdev_priv(dev); 1667 t->collect_md = true; 1668 1669 err = ipgre_newlink(net, dev, tb, NULL, NULL); 1670 if (err < 0) { 1671 free_netdev(dev); 1672 return ERR_PTR(err); 1673 } 1674 1675 /* openvswitch users expect packet sizes to be unrestricted, 1676 * so set the largest MTU we can. 1677 */ 1678 err = __ip_tunnel_change_mtu(dev, IP_MAX_MTU, false); 1679 if (err) 1680 goto out; 1681 1682 err = rtnl_configure_link(dev, NULL); 1683 if (err < 0) 1684 goto out; 1685 1686 return dev; 1687out: 1688 ip_tunnel_dellink(dev, &list_kill); 1689 unregister_netdevice_many(&list_kill); 1690 return ERR_PTR(err); 1691} 1692EXPORT_SYMBOL_GPL(gretap_fb_dev_create); 1693 1694static int __net_init ipgre_tap_init_net(struct net *net) 1695{ 1696 return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, "gretap0"); 1697} 1698 1699static void __net_exit ipgre_tap_exit_batch_net(struct list_head *list_net) 1700{ 1701 ip_tunnel_delete_nets(list_net, gre_tap_net_id, &ipgre_tap_ops); 1702} 1703 1704static struct pernet_operations ipgre_tap_net_ops = { 1705 .init = ipgre_tap_init_net, 1706 .exit_batch = ipgre_tap_exit_batch_net, 1707 .id = &gre_tap_net_id, 1708 .size = sizeof(struct ip_tunnel_net), 1709}; 1710 1711static int __net_init erspan_init_net(struct net *net) 1712{ 1713 return ip_tunnel_init_net(net, erspan_net_id, 1714 &erspan_link_ops, "erspan0"); 1715} 1716 1717static void __net_exit erspan_exit_batch_net(struct list_head *net_list) 1718{ 1719 ip_tunnel_delete_nets(net_list, erspan_net_id, &erspan_link_ops); 1720} 1721 1722static struct pernet_operations erspan_net_ops = { 1723 .init = erspan_init_net, 1724 .exit_batch = erspan_exit_batch_net, 1725 .id = &erspan_net_id, 1726 .size = sizeof(struct ip_tunnel_net), 1727}; 1728 1729static int __init ipgre_init(void) 1730{ 1731 int err; 1732 1733 pr_info("GRE over IPv4 tunneling driver\n"); 1734 1735 err = register_pernet_device(&ipgre_net_ops); 1736 if (err < 0) 1737 return err; 1738 1739 err = register_pernet_device(&ipgre_tap_net_ops); 1740 if (err < 0) 1741 goto pnet_tap_failed; 1742 1743 err = register_pernet_device(&erspan_net_ops); 1744 if (err < 0) 1745 goto pnet_erspan_failed; 1746 1747 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO); 1748 if (err < 0) { 1749 pr_info("%s: can't add protocol\n", __func__); 1750 goto add_proto_failed; 1751 } 1752 1753 err = rtnl_link_register(&ipgre_link_ops); 1754 if (err < 0) 1755 goto rtnl_link_failed; 1756 1757 err = rtnl_link_register(&ipgre_tap_ops); 1758 if (err < 0) 1759 goto tap_ops_failed; 1760 1761 err = rtnl_link_register(&erspan_link_ops); 1762 if (err < 0) 1763 goto erspan_link_failed; 1764 1765 return 0; 1766 1767erspan_link_failed: 1768 rtnl_link_unregister(&ipgre_tap_ops); 1769tap_ops_failed: 1770 rtnl_link_unregister(&ipgre_link_ops); 1771rtnl_link_failed: 1772 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); 1773add_proto_failed: 1774 unregister_pernet_device(&erspan_net_ops); 1775pnet_erspan_failed: 1776 unregister_pernet_device(&ipgre_tap_net_ops); 1777pnet_tap_failed: 1778 unregister_pernet_device(&ipgre_net_ops); 1779 return err; 1780} 1781 1782static void __exit ipgre_fini(void) 1783{ 1784 rtnl_link_unregister(&ipgre_tap_ops); 1785 rtnl_link_unregister(&ipgre_link_ops); 1786 rtnl_link_unregister(&erspan_link_ops); 1787 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); 1788 unregister_pernet_device(&ipgre_tap_net_ops); 1789 unregister_pernet_device(&ipgre_net_ops); 1790 unregister_pernet_device(&erspan_net_ops); 1791} 1792 1793module_init(ipgre_init); 1794module_exit(ipgre_fini); 1795MODULE_LICENSE("GPL"); 1796MODULE_ALIAS_RTNL_LINK("gre"); 1797MODULE_ALIAS_RTNL_LINK("gretap"); 1798MODULE_ALIAS_RTNL_LINK("erspan"); 1799MODULE_ALIAS_NETDEV("gre0"); 1800MODULE_ALIAS_NETDEV("gretap0"); 1801MODULE_ALIAS_NETDEV("erspan0"); 1802