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