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 if (unlikely(!pskb_may_pull(skb, 284 gre_hdr_len + sizeof(*ershdr)))) 285 return PACKET_REJECT; 286 287 ershdr = (struct erspan_base_hdr *)(skb->data + gre_hdr_len); 288 ver = ershdr->ver; 289 iph = ip_hdr(skb); 290 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, 291 tpi->flags | TUNNEL_KEY, 292 iph->saddr, iph->daddr, tpi->key); 293 } 294 295 if (tunnel) { 296 if (is_erspan_type1(gre_hdr_len)) 297 len = gre_hdr_len; 298 else 299 len = gre_hdr_len + erspan_hdr_len(ver); 300 301 if (unlikely(!pskb_may_pull(skb, len))) 302 return PACKET_REJECT; 303 304 if (__iptunnel_pull_header(skb, 305 len, 306 htons(ETH_P_TEB), 307 false, false) < 0) 308 goto drop; 309 310 if (tunnel->collect_md) { 311 struct erspan_metadata *pkt_md, *md; 312 struct ip_tunnel_info *info; 313 unsigned char *gh; 314 __be64 tun_id; 315 __be16 flags; 316 317 tpi->flags |= TUNNEL_KEY; 318 flags = tpi->flags; 319 tun_id = key32_to_tunnel_id(tpi->key); 320 321 tun_dst = ip_tun_rx_dst(skb, flags, 322 tun_id, sizeof(*md)); 323 if (!tun_dst) 324 return PACKET_REJECT; 325 326 /* skb can be uncloned in __iptunnel_pull_header, so 327 * old pkt_md is no longer valid and we need to reset 328 * it 329 */ 330 gh = skb_network_header(skb) + 331 skb_network_header_len(skb); 332 pkt_md = (struct erspan_metadata *)(gh + gre_hdr_len + 333 sizeof(*ershdr)); 334 md = ip_tunnel_info_opts(&tun_dst->u.tun_info); 335 md->version = ver; 336 md2 = &md->u.md2; 337 memcpy(md2, pkt_md, ver == 1 ? ERSPAN_V1_MDSIZE : 338 ERSPAN_V2_MDSIZE); 339 340 info = &tun_dst->u.tun_info; 341 info->key.tun_flags |= TUNNEL_ERSPAN_OPT; 342 info->options_len = sizeof(*md); 343 } 344 345 skb_reset_mac_header(skb); 346 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error); 347 return PACKET_RCVD; 348 } 349 return PACKET_REJECT; 350 351drop: 352 kfree_skb(skb); 353 return PACKET_RCVD; 354} 355 356static int __ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi, 357 struct ip_tunnel_net *itn, int hdr_len, bool raw_proto) 358{ 359 struct metadata_dst *tun_dst = NULL; 360 const struct iphdr *iph; 361 struct ip_tunnel *tunnel; 362 363 iph = ip_hdr(skb); 364 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags, 365 iph->saddr, iph->daddr, tpi->key); 366 367 if (tunnel) { 368 const struct iphdr *tnl_params; 369 370 if (__iptunnel_pull_header(skb, hdr_len, tpi->proto, 371 raw_proto, false) < 0) 372 goto drop; 373 374 /* Special case for ipgre_header_parse(), which expects the 375 * mac_header to point to the outer IP header. 376 */ 377 if (tunnel->dev->header_ops == &ipgre_header_ops) 378 skb_pop_mac_header(skb); 379 else 380 skb_reset_mac_header(skb); 381 382 tnl_params = &tunnel->parms.iph; 383 if (tunnel->collect_md || tnl_params->daddr == 0) { 384 __be16 flags; 385 __be64 tun_id; 386 387 flags = tpi->flags & (TUNNEL_CSUM | TUNNEL_KEY); 388 tun_id = key32_to_tunnel_id(tpi->key); 389 tun_dst = ip_tun_rx_dst(skb, flags, tun_id, 0); 390 if (!tun_dst) 391 return PACKET_REJECT; 392 } 393 394 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error); 395 return PACKET_RCVD; 396 } 397 return PACKET_NEXT; 398 399drop: 400 kfree_skb(skb); 401 return PACKET_RCVD; 402} 403 404static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi, 405 int hdr_len) 406{ 407 struct net *net = dev_net(skb->dev); 408 struct ip_tunnel_net *itn; 409 int res; 410 411 if (tpi->proto == htons(ETH_P_TEB)) 412 itn = net_generic(net, gre_tap_net_id); 413 else 414 itn = net_generic(net, ipgre_net_id); 415 416 res = __ipgre_rcv(skb, tpi, itn, hdr_len, false); 417 if (res == PACKET_NEXT && tpi->proto == htons(ETH_P_TEB)) { 418 /* ipgre tunnels in collect metadata mode should receive 419 * also ETH_P_TEB traffic. 420 */ 421 itn = net_generic(net, ipgre_net_id); 422 res = __ipgre_rcv(skb, tpi, itn, hdr_len, true); 423 } 424 return res; 425} 426 427static int gre_rcv(struct sk_buff *skb) 428{ 429 struct tnl_ptk_info tpi; 430 bool csum_err = false; 431 int hdr_len; 432 433#ifdef CONFIG_NET_IPGRE_BROADCAST 434 if (ipv4_is_multicast(ip_hdr(skb)->daddr)) { 435 /* Looped back packet, drop it! */ 436 if (rt_is_output_route(skb_rtable(skb))) 437 goto drop; 438 } 439#endif 440 441 hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IP), 0); 442 if (hdr_len < 0) 443 goto drop; 444 445 if (unlikely(tpi.proto == htons(ETH_P_ERSPAN) || 446 tpi.proto == htons(ETH_P_ERSPAN2))) { 447 if (erspan_rcv(skb, &tpi, hdr_len) == PACKET_RCVD) 448 return 0; 449 goto out; 450 } 451 452 if (ipgre_rcv(skb, &tpi, hdr_len) == PACKET_RCVD) 453 return 0; 454 455out: 456 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 457drop: 458 kfree_skb(skb); 459 return 0; 460} 461 462static void __gre_xmit(struct sk_buff *skb, struct net_device *dev, 463 const struct iphdr *tnl_params, 464 __be16 proto) 465{ 466 struct ip_tunnel *tunnel = netdev_priv(dev); 467 __be16 flags = tunnel->parms.o_flags; 468 469 /* Push GRE header. */ 470 gre_build_header(skb, tunnel->tun_hlen, 471 flags, proto, tunnel->parms.o_key, 472 (flags & TUNNEL_SEQ) ? htonl(atomic_fetch_inc(&tunnel->o_seqno)) : 0); 473 474 ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol); 475} 476 477static int gre_handle_offloads(struct sk_buff *skb, bool csum) 478{ 479 return iptunnel_handle_offloads(skb, csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE); 480} 481 482static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev, 483 __be16 proto) 484{ 485 struct ip_tunnel *tunnel = netdev_priv(dev); 486 struct ip_tunnel_info *tun_info; 487 const struct ip_tunnel_key *key; 488 int tunnel_hlen; 489 __be16 flags; 490 491 tun_info = skb_tunnel_info(skb); 492 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) || 493 ip_tunnel_info_af(tun_info) != AF_INET)) 494 goto err_free_skb; 495 496 key = &tun_info->key; 497 tunnel_hlen = gre_calc_hlen(key->tun_flags); 498 499 if (skb_cow_head(skb, dev->needed_headroom)) 500 goto err_free_skb; 501 502 /* Push Tunnel header. */ 503 if (gre_handle_offloads(skb, !!(tun_info->key.tun_flags & TUNNEL_CSUM))) 504 goto err_free_skb; 505 506 flags = tun_info->key.tun_flags & 507 (TUNNEL_CSUM | TUNNEL_KEY | TUNNEL_SEQ); 508 gre_build_header(skb, tunnel_hlen, flags, proto, 509 tunnel_id_to_key32(tun_info->key.tun_id), 510 (flags & TUNNEL_SEQ) ? htonl(atomic_fetch_inc(&tunnel->o_seqno)) : 0); 511 512 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen); 513 514 return; 515 516err_free_skb: 517 kfree_skb(skb); 518 DEV_STATS_INC(dev, tx_dropped); 519} 520 521static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev) 522{ 523 struct ip_tunnel *tunnel = netdev_priv(dev); 524 struct ip_tunnel_info *tun_info; 525 const struct ip_tunnel_key *key; 526 struct erspan_metadata *md; 527 bool truncate = false; 528 __be16 proto; 529 int tunnel_hlen; 530 int version; 531 int nhoff; 532 533 tun_info = skb_tunnel_info(skb); 534 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) || 535 ip_tunnel_info_af(tun_info) != AF_INET)) 536 goto err_free_skb; 537 538 key = &tun_info->key; 539 if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT)) 540 goto err_free_skb; 541 if (tun_info->options_len < sizeof(*md)) 542 goto err_free_skb; 543 md = ip_tunnel_info_opts(tun_info); 544 545 /* ERSPAN has fixed 8 byte GRE header */ 546 version = md->version; 547 tunnel_hlen = 8 + erspan_hdr_len(version); 548 549 if (skb_cow_head(skb, dev->needed_headroom)) 550 goto err_free_skb; 551 552 if (gre_handle_offloads(skb, false)) 553 goto err_free_skb; 554 555 if (skb->len > dev->mtu + dev->hard_header_len) { 556 if (pskb_trim(skb, dev->mtu + dev->hard_header_len)) 557 goto err_free_skb; 558 truncate = true; 559 } 560 561 nhoff = skb_network_offset(skb); 562 if (skb->protocol == htons(ETH_P_IP) && 563 (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff)) 564 truncate = true; 565 566 if (skb->protocol == htons(ETH_P_IPV6)) { 567 int thoff; 568 569 if (skb_transport_header_was_set(skb)) 570 thoff = skb_transport_offset(skb); 571 else 572 thoff = nhoff + sizeof(struct ipv6hdr); 573 if (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff) 574 truncate = true; 575 } 576 577 if (version == 1) { 578 erspan_build_header(skb, ntohl(tunnel_id_to_key32(key->tun_id)), 579 ntohl(md->u.index), truncate, true); 580 proto = htons(ETH_P_ERSPAN); 581 } else if (version == 2) { 582 erspan_build_header_v2(skb, 583 ntohl(tunnel_id_to_key32(key->tun_id)), 584 md->u.md2.dir, 585 get_hwid(&md->u.md2), 586 truncate, true); 587 proto = htons(ETH_P_ERSPAN2); 588 } else { 589 goto err_free_skb; 590 } 591 592 gre_build_header(skb, 8, TUNNEL_SEQ, 593 proto, 0, htonl(atomic_fetch_inc(&tunnel->o_seqno))); 594 595 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen); 596 597 return; 598 599err_free_skb: 600 kfree_skb(skb); 601 DEV_STATS_INC(dev, tx_dropped); 602} 603 604static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb) 605{ 606 struct ip_tunnel_info *info = skb_tunnel_info(skb); 607 const struct ip_tunnel_key *key; 608 struct rtable *rt; 609 struct flowi4 fl4; 610 611 if (ip_tunnel_info_af(info) != AF_INET) 612 return -EINVAL; 613 614 key = &info->key; 615 ip_tunnel_init_flow(&fl4, IPPROTO_GRE, key->u.ipv4.dst, key->u.ipv4.src, 616 tunnel_id_to_key32(key->tun_id), 617 key->tos & ~INET_ECN_MASK, dev_net(dev), 0, 618 skb->mark, skb_get_hash(skb), key->flow_flags); 619 rt = ip_route_output_key(dev_net(dev), &fl4); 620 if (IS_ERR(rt)) 621 return PTR_ERR(rt); 622 623 ip_rt_put(rt); 624 info->key.u.ipv4.src = fl4.saddr; 625 return 0; 626} 627 628static netdev_tx_t ipgre_xmit(struct sk_buff *skb, 629 struct net_device *dev) 630{ 631 struct ip_tunnel *tunnel = netdev_priv(dev); 632 const struct iphdr *tnl_params; 633 634 if (!pskb_inet_may_pull(skb)) 635 goto free_skb; 636 637 if (tunnel->collect_md) { 638 gre_fb_xmit(skb, dev, skb->protocol); 639 return NETDEV_TX_OK; 640 } 641 642 if (dev->header_ops) { 643 int pull_len = tunnel->hlen + sizeof(struct iphdr); 644 645 if (skb_cow_head(skb, 0)) 646 goto free_skb; 647 648 tnl_params = (const struct iphdr *)skb->data; 649 650 if (!pskb_network_may_pull(skb, pull_len)) 651 goto free_skb; 652 653 /* ip_tunnel_xmit() needs skb->data pointing to gre header. */ 654 skb_pull(skb, pull_len); 655 skb_reset_mac_header(skb); 656 657 if (skb->ip_summed == CHECKSUM_PARTIAL && 658 skb_checksum_start(skb) < skb->data) 659 goto free_skb; 660 } else { 661 if (skb_cow_head(skb, dev->needed_headroom)) 662 goto free_skb; 663 664 tnl_params = &tunnel->parms.iph; 665 } 666 667 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM))) 668 goto free_skb; 669 670 __gre_xmit(skb, dev, tnl_params, skb->protocol); 671 return NETDEV_TX_OK; 672 673free_skb: 674 kfree_skb(skb); 675 DEV_STATS_INC(dev, tx_dropped); 676 return NETDEV_TX_OK; 677} 678 679static netdev_tx_t erspan_xmit(struct sk_buff *skb, 680 struct net_device *dev) 681{ 682 struct ip_tunnel *tunnel = netdev_priv(dev); 683 bool truncate = false; 684 __be16 proto; 685 686 if (!pskb_inet_may_pull(skb)) 687 goto free_skb; 688 689 if (tunnel->collect_md) { 690 erspan_fb_xmit(skb, dev); 691 return NETDEV_TX_OK; 692 } 693 694 if (gre_handle_offloads(skb, false)) 695 goto free_skb; 696 697 if (skb_cow_head(skb, dev->needed_headroom)) 698 goto free_skb; 699 700 if (skb->len > dev->mtu + dev->hard_header_len) { 701 if (pskb_trim(skb, dev->mtu + dev->hard_header_len)) 702 goto free_skb; 703 truncate = true; 704 } 705 706 /* Push ERSPAN header */ 707 if (tunnel->erspan_ver == 0) { 708 proto = htons(ETH_P_ERSPAN); 709 tunnel->parms.o_flags &= ~TUNNEL_SEQ; 710 } else if (tunnel->erspan_ver == 1) { 711 erspan_build_header(skb, ntohl(tunnel->parms.o_key), 712 tunnel->index, 713 truncate, true); 714 proto = htons(ETH_P_ERSPAN); 715 } else if (tunnel->erspan_ver == 2) { 716 erspan_build_header_v2(skb, ntohl(tunnel->parms.o_key), 717 tunnel->dir, tunnel->hwid, 718 truncate, true); 719 proto = htons(ETH_P_ERSPAN2); 720 } else { 721 goto free_skb; 722 } 723 724 tunnel->parms.o_flags &= ~TUNNEL_KEY; 725 __gre_xmit(skb, dev, &tunnel->parms.iph, proto); 726 return NETDEV_TX_OK; 727 728free_skb: 729 kfree_skb(skb); 730 DEV_STATS_INC(dev, tx_dropped); 731 return NETDEV_TX_OK; 732} 733 734static netdev_tx_t gre_tap_xmit(struct sk_buff *skb, 735 struct net_device *dev) 736{ 737 struct ip_tunnel *tunnel = netdev_priv(dev); 738 739 if (!pskb_inet_may_pull(skb)) 740 goto free_skb; 741 742 if (tunnel->collect_md) { 743 gre_fb_xmit(skb, dev, htons(ETH_P_TEB)); 744 return NETDEV_TX_OK; 745 } 746 747 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM))) 748 goto free_skb; 749 750 if (skb_cow_head(skb, dev->needed_headroom)) 751 goto free_skb; 752 753 __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB)); 754 return NETDEV_TX_OK; 755 756free_skb: 757 kfree_skb(skb); 758 DEV_STATS_INC(dev, tx_dropped); 759 return NETDEV_TX_OK; 760} 761 762static void ipgre_link_update(struct net_device *dev, bool set_mtu) 763{ 764 struct ip_tunnel *tunnel = netdev_priv(dev); 765 __be16 flags; 766 int len; 767 768 len = tunnel->tun_hlen; 769 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags); 770 len = tunnel->tun_hlen - len; 771 tunnel->hlen = tunnel->hlen + len; 772 773 if (dev->header_ops) 774 dev->hard_header_len += len; 775 else 776 dev->needed_headroom += len; 777 778 if (set_mtu) 779 dev->mtu = max_t(int, dev->mtu - len, 68); 780 781 flags = tunnel->parms.o_flags; 782 783 if (flags & TUNNEL_SEQ || 784 (flags & TUNNEL_CSUM && tunnel->encap.type != TUNNEL_ENCAP_NONE)) { 785 dev->features &= ~NETIF_F_GSO_SOFTWARE; 786 dev->hw_features &= ~NETIF_F_GSO_SOFTWARE; 787 } else { 788 dev->features |= NETIF_F_GSO_SOFTWARE; 789 dev->hw_features |= NETIF_F_GSO_SOFTWARE; 790 } 791} 792 793static int ipgre_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, 794 int cmd) 795{ 796 int err; 797 798 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) { 799 if (p->iph.version != 4 || p->iph.protocol != IPPROTO_GRE || 800 p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)) || 801 ((p->i_flags | p->o_flags) & (GRE_VERSION | GRE_ROUTING))) 802 return -EINVAL; 803 } 804 805 p->i_flags = gre_flags_to_tnl_flags(p->i_flags); 806 p->o_flags = gre_flags_to_tnl_flags(p->o_flags); 807 808 err = ip_tunnel_ctl(dev, p, cmd); 809 if (err) 810 return err; 811 812 if (cmd == SIOCCHGTUNNEL) { 813 struct ip_tunnel *t = netdev_priv(dev); 814 815 t->parms.i_flags = p->i_flags; 816 t->parms.o_flags = p->o_flags; 817 818 if (strcmp(dev->rtnl_link_ops->kind, "erspan")) 819 ipgre_link_update(dev, true); 820 } 821 822 p->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags); 823 p->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags); 824 return 0; 825} 826 827/* Nice toy. Unfortunately, useless in real life :-) 828 It allows to construct virtual multiprotocol broadcast "LAN" 829 over the Internet, provided multicast routing is tuned. 830 831 832 I have no idea was this bicycle invented before me, 833 so that I had to set ARPHRD_IPGRE to a random value. 834 I have an impression, that Cisco could make something similar, 835 but this feature is apparently missing in IOS<=11.2(8). 836 837 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks 838 with broadcast 224.66.66.66. If you have access to mbone, play with me :-) 839 840 ping -t 255 224.66.66.66 841 842 If nobody answers, mbone does not work. 843 844 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255 845 ip addr add 10.66.66.<somewhat>/24 dev Universe 846 ifconfig Universe up 847 ifconfig Universe add fe80::<Your_real_addr>/10 848 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96 849 ftp 10.66.66.66 850 ... 851 ftp fec0:6666:6666::193.233.7.65 852 ... 853 */ 854static int ipgre_header(struct sk_buff *skb, struct net_device *dev, 855 unsigned short type, 856 const void *daddr, const void *saddr, unsigned int len) 857{ 858 struct ip_tunnel *t = netdev_priv(dev); 859 struct iphdr *iph; 860 struct gre_base_hdr *greh; 861 862 iph = skb_push(skb, t->hlen + sizeof(*iph)); 863 greh = (struct gre_base_hdr *)(iph+1); 864 greh->flags = gre_tnl_flags_to_gre_flags(t->parms.o_flags); 865 greh->protocol = htons(type); 866 867 memcpy(iph, &t->parms.iph, sizeof(struct iphdr)); 868 869 /* Set the source hardware address. */ 870 if (saddr) 871 memcpy(&iph->saddr, saddr, 4); 872 if (daddr) 873 memcpy(&iph->daddr, daddr, 4); 874 if (iph->daddr) 875 return t->hlen + sizeof(*iph); 876 877 return -(t->hlen + sizeof(*iph)); 878} 879 880static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr) 881{ 882 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb); 883 memcpy(haddr, &iph->saddr, 4); 884 return 4; 885} 886 887static const struct header_ops ipgre_header_ops = { 888 .create = ipgre_header, 889 .parse = ipgre_header_parse, 890}; 891 892#ifdef CONFIG_NET_IPGRE_BROADCAST 893static int ipgre_open(struct net_device *dev) 894{ 895 struct ip_tunnel *t = netdev_priv(dev); 896 897 if (ipv4_is_multicast(t->parms.iph.daddr)) { 898 struct flowi4 fl4; 899 struct rtable *rt; 900 901 rt = ip_route_output_gre(t->net, &fl4, 902 t->parms.iph.daddr, 903 t->parms.iph.saddr, 904 t->parms.o_key, 905 RT_TOS(t->parms.iph.tos), 906 t->parms.link); 907 if (IS_ERR(rt)) 908 return -EADDRNOTAVAIL; 909 dev = rt->dst.dev; 910 ip_rt_put(rt); 911 if (!__in_dev_get_rtnl(dev)) 912 return -EADDRNOTAVAIL; 913 t->mlink = dev->ifindex; 914 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr); 915 } 916 return 0; 917} 918 919static int ipgre_close(struct net_device *dev) 920{ 921 struct ip_tunnel *t = netdev_priv(dev); 922 923 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) { 924 struct in_device *in_dev; 925 in_dev = inetdev_by_index(t->net, t->mlink); 926 if (in_dev) 927 ip_mc_dec_group(in_dev, t->parms.iph.daddr); 928 } 929 return 0; 930} 931#endif 932 933static const struct net_device_ops ipgre_netdev_ops = { 934 .ndo_init = ipgre_tunnel_init, 935 .ndo_uninit = ip_tunnel_uninit, 936#ifdef CONFIG_NET_IPGRE_BROADCAST 937 .ndo_open = ipgre_open, 938 .ndo_stop = ipgre_close, 939#endif 940 .ndo_start_xmit = ipgre_xmit, 941 .ndo_siocdevprivate = ip_tunnel_siocdevprivate, 942 .ndo_change_mtu = ip_tunnel_change_mtu, 943 .ndo_get_stats64 = dev_get_tstats64, 944 .ndo_get_iflink = ip_tunnel_get_iflink, 945 .ndo_tunnel_ctl = ipgre_tunnel_ctl, 946}; 947 948#define GRE_FEATURES (NETIF_F_SG | \ 949 NETIF_F_FRAGLIST | \ 950 NETIF_F_HIGHDMA | \ 951 NETIF_F_HW_CSUM) 952 953static void ipgre_tunnel_setup(struct net_device *dev) 954{ 955 dev->netdev_ops = &ipgre_netdev_ops; 956 dev->type = ARPHRD_IPGRE; 957 ip_tunnel_setup(dev, ipgre_net_id); 958} 959 960static void __gre_tunnel_init(struct net_device *dev) 961{ 962 struct ip_tunnel *tunnel; 963 __be16 flags; 964 965 tunnel = netdev_priv(dev); 966 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags); 967 tunnel->parms.iph.protocol = IPPROTO_GRE; 968 969 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen; 970 dev->needed_headroom = tunnel->hlen + sizeof(tunnel->parms.iph); 971 972 dev->features |= GRE_FEATURES | NETIF_F_LLTX; 973 dev->hw_features |= GRE_FEATURES; 974 975 flags = tunnel->parms.o_flags; 976 977 /* TCP offload with GRE SEQ is not supported, nor can we support 2 978 * levels of outer headers requiring an update. 979 */ 980 if (flags & TUNNEL_SEQ) 981 return; 982 if (flags & TUNNEL_CSUM && tunnel->encap.type != TUNNEL_ENCAP_NONE) 983 return; 984 985 dev->features |= NETIF_F_GSO_SOFTWARE; 986 dev->hw_features |= NETIF_F_GSO_SOFTWARE; 987} 988 989static int ipgre_tunnel_init(struct net_device *dev) 990{ 991 struct ip_tunnel *tunnel = netdev_priv(dev); 992 struct iphdr *iph = &tunnel->parms.iph; 993 994 __gre_tunnel_init(dev); 995 996 __dev_addr_set(dev, &iph->saddr, 4); 997 memcpy(dev->broadcast, &iph->daddr, 4); 998 999 dev->flags = IFF_NOARP; 1000 netif_keep_dst(dev); 1001 dev->addr_len = 4; 1002 1003 if (iph->daddr && !tunnel->collect_md) { 1004#ifdef CONFIG_NET_IPGRE_BROADCAST 1005 if (ipv4_is_multicast(iph->daddr)) { 1006 if (!iph->saddr) 1007 return -EINVAL; 1008 dev->flags = IFF_BROADCAST; 1009 dev->header_ops = &ipgre_header_ops; 1010 dev->hard_header_len = tunnel->hlen + sizeof(*iph); 1011 dev->needed_headroom = 0; 1012 } 1013#endif 1014 } else if (!tunnel->collect_md) { 1015 dev->header_ops = &ipgre_header_ops; 1016 dev->hard_header_len = tunnel->hlen + sizeof(*iph); 1017 dev->needed_headroom = 0; 1018 } 1019 1020 return ip_tunnel_init(dev); 1021} 1022 1023static const struct gre_protocol ipgre_protocol = { 1024 .handler = gre_rcv, 1025 .err_handler = gre_err, 1026}; 1027 1028static int __net_init ipgre_init_net(struct net *net) 1029{ 1030 return ip_tunnel_init_net(net, ipgre_net_id, &ipgre_link_ops, NULL); 1031} 1032 1033static void __net_exit ipgre_exit_batch_rtnl(struct list_head *list_net, 1034 struct list_head *dev_to_kill) 1035{ 1036 ip_tunnel_delete_nets(list_net, ipgre_net_id, &ipgre_link_ops, 1037 dev_to_kill); 1038} 1039 1040static struct pernet_operations ipgre_net_ops = { 1041 .init = ipgre_init_net, 1042 .exit_batch_rtnl = ipgre_exit_batch_rtnl, 1043 .id = &ipgre_net_id, 1044 .size = sizeof(struct ip_tunnel_net), 1045}; 1046 1047static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[], 1048 struct netlink_ext_ack *extack) 1049{ 1050 __be16 flags; 1051 1052 if (!data) 1053 return 0; 1054 1055 flags = 0; 1056 if (data[IFLA_GRE_IFLAGS]) 1057 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); 1058 if (data[IFLA_GRE_OFLAGS]) 1059 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); 1060 if (flags & (GRE_VERSION|GRE_ROUTING)) 1061 return -EINVAL; 1062 1063 if (data[IFLA_GRE_COLLECT_METADATA] && 1064 data[IFLA_GRE_ENCAP_TYPE] && 1065 nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]) != TUNNEL_ENCAP_NONE) 1066 return -EINVAL; 1067 1068 return 0; 1069} 1070 1071static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[], 1072 struct netlink_ext_ack *extack) 1073{ 1074 __be32 daddr; 1075 1076 if (tb[IFLA_ADDRESS]) { 1077 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) 1078 return -EINVAL; 1079 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) 1080 return -EADDRNOTAVAIL; 1081 } 1082 1083 if (!data) 1084 goto out; 1085 1086 if (data[IFLA_GRE_REMOTE]) { 1087 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4); 1088 if (!daddr) 1089 return -EINVAL; 1090 } 1091 1092out: 1093 return ipgre_tunnel_validate(tb, data, extack); 1094} 1095 1096static int erspan_validate(struct nlattr *tb[], struct nlattr *data[], 1097 struct netlink_ext_ack *extack) 1098{ 1099 __be16 flags = 0; 1100 int ret; 1101 1102 if (!data) 1103 return 0; 1104 1105 ret = ipgre_tap_validate(tb, data, extack); 1106 if (ret) 1107 return ret; 1108 1109 if (data[IFLA_GRE_ERSPAN_VER] && 1110 nla_get_u8(data[IFLA_GRE_ERSPAN_VER]) == 0) 1111 return 0; 1112 1113 /* ERSPAN type II/III should only have GRE sequence and key flag */ 1114 if (data[IFLA_GRE_OFLAGS]) 1115 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); 1116 if (data[IFLA_GRE_IFLAGS]) 1117 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); 1118 if (!data[IFLA_GRE_COLLECT_METADATA] && 1119 flags != (GRE_SEQ | GRE_KEY)) 1120 return -EINVAL; 1121 1122 /* ERSPAN Session ID only has 10-bit. Since we reuse 1123 * 32-bit key field as ID, check it's range. 1124 */ 1125 if (data[IFLA_GRE_IKEY] && 1126 (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK)) 1127 return -EINVAL; 1128 1129 if (data[IFLA_GRE_OKEY] && 1130 (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK)) 1131 return -EINVAL; 1132 1133 return 0; 1134} 1135 1136static int ipgre_netlink_parms(struct net_device *dev, 1137 struct nlattr *data[], 1138 struct nlattr *tb[], 1139 struct ip_tunnel_parm *parms, 1140 __u32 *fwmark) 1141{ 1142 struct ip_tunnel *t = netdev_priv(dev); 1143 1144 memset(parms, 0, sizeof(*parms)); 1145 1146 parms->iph.protocol = IPPROTO_GRE; 1147 1148 if (!data) 1149 return 0; 1150 1151 if (data[IFLA_GRE_LINK]) 1152 parms->link = nla_get_u32(data[IFLA_GRE_LINK]); 1153 1154 if (data[IFLA_GRE_IFLAGS]) 1155 parms->i_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_IFLAGS])); 1156 1157 if (data[IFLA_GRE_OFLAGS]) 1158 parms->o_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_OFLAGS])); 1159 1160 if (data[IFLA_GRE_IKEY]) 1161 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]); 1162 1163 if (data[IFLA_GRE_OKEY]) 1164 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]); 1165 1166 if (data[IFLA_GRE_LOCAL]) 1167 parms->iph.saddr = nla_get_in_addr(data[IFLA_GRE_LOCAL]); 1168 1169 if (data[IFLA_GRE_REMOTE]) 1170 parms->iph.daddr = nla_get_in_addr(data[IFLA_GRE_REMOTE]); 1171 1172 if (data[IFLA_GRE_TTL]) 1173 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]); 1174 1175 if (data[IFLA_GRE_TOS]) 1176 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]); 1177 1178 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC])) { 1179 if (t->ignore_df) 1180 return -EINVAL; 1181 parms->iph.frag_off = htons(IP_DF); 1182 } 1183 1184 if (data[IFLA_GRE_COLLECT_METADATA]) { 1185 t->collect_md = true; 1186 if (dev->type == ARPHRD_IPGRE) 1187 dev->type = ARPHRD_NONE; 1188 } 1189 1190 if (data[IFLA_GRE_IGNORE_DF]) { 1191 if (nla_get_u8(data[IFLA_GRE_IGNORE_DF]) 1192 && (parms->iph.frag_off & htons(IP_DF))) 1193 return -EINVAL; 1194 t->ignore_df = !!nla_get_u8(data[IFLA_GRE_IGNORE_DF]); 1195 } 1196 1197 if (data[IFLA_GRE_FWMARK]) 1198 *fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]); 1199 1200 return 0; 1201} 1202 1203static int erspan_netlink_parms(struct net_device *dev, 1204 struct nlattr *data[], 1205 struct nlattr *tb[], 1206 struct ip_tunnel_parm *parms, 1207 __u32 *fwmark) 1208{ 1209 struct ip_tunnel *t = netdev_priv(dev); 1210 int err; 1211 1212 err = ipgre_netlink_parms(dev, data, tb, parms, fwmark); 1213 if (err) 1214 return err; 1215 if (!data) 1216 return 0; 1217 1218 if (data[IFLA_GRE_ERSPAN_VER]) { 1219 t->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]); 1220 1221 if (t->erspan_ver > 2) 1222 return -EINVAL; 1223 } 1224 1225 if (t->erspan_ver == 1) { 1226 if (data[IFLA_GRE_ERSPAN_INDEX]) { 1227 t->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]); 1228 if (t->index & ~INDEX_MASK) 1229 return -EINVAL; 1230 } 1231 } else if (t->erspan_ver == 2) { 1232 if (data[IFLA_GRE_ERSPAN_DIR]) { 1233 t->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]); 1234 if (t->dir & ~(DIR_MASK >> DIR_OFFSET)) 1235 return -EINVAL; 1236 } 1237 if (data[IFLA_GRE_ERSPAN_HWID]) { 1238 t->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]); 1239 if (t->hwid & ~(HWID_MASK >> HWID_OFFSET)) 1240 return -EINVAL; 1241 } 1242 } 1243 1244 return 0; 1245} 1246 1247/* This function returns true when ENCAP attributes are present in the nl msg */ 1248static bool ipgre_netlink_encap_parms(struct nlattr *data[], 1249 struct ip_tunnel_encap *ipencap) 1250{ 1251 bool ret = false; 1252 1253 memset(ipencap, 0, sizeof(*ipencap)); 1254 1255 if (!data) 1256 return ret; 1257 1258 if (data[IFLA_GRE_ENCAP_TYPE]) { 1259 ret = true; 1260 ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]); 1261 } 1262 1263 if (data[IFLA_GRE_ENCAP_FLAGS]) { 1264 ret = true; 1265 ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]); 1266 } 1267 1268 if (data[IFLA_GRE_ENCAP_SPORT]) { 1269 ret = true; 1270 ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]); 1271 } 1272 1273 if (data[IFLA_GRE_ENCAP_DPORT]) { 1274 ret = true; 1275 ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]); 1276 } 1277 1278 return ret; 1279} 1280 1281static int gre_tap_init(struct net_device *dev) 1282{ 1283 __gre_tunnel_init(dev); 1284 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1285 netif_keep_dst(dev); 1286 1287 return ip_tunnel_init(dev); 1288} 1289 1290static const struct net_device_ops gre_tap_netdev_ops = { 1291 .ndo_init = gre_tap_init, 1292 .ndo_uninit = ip_tunnel_uninit, 1293 .ndo_start_xmit = gre_tap_xmit, 1294 .ndo_set_mac_address = eth_mac_addr, 1295 .ndo_validate_addr = eth_validate_addr, 1296 .ndo_change_mtu = ip_tunnel_change_mtu, 1297 .ndo_get_stats64 = dev_get_tstats64, 1298 .ndo_get_iflink = ip_tunnel_get_iflink, 1299 .ndo_fill_metadata_dst = gre_fill_metadata_dst, 1300}; 1301 1302static int erspan_tunnel_init(struct net_device *dev) 1303{ 1304 struct ip_tunnel *tunnel = netdev_priv(dev); 1305 1306 if (tunnel->erspan_ver == 0) 1307 tunnel->tun_hlen = 4; /* 4-byte GRE hdr. */ 1308 else 1309 tunnel->tun_hlen = 8; /* 8-byte GRE hdr. */ 1310 1311 tunnel->parms.iph.protocol = IPPROTO_GRE; 1312 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen + 1313 erspan_hdr_len(tunnel->erspan_ver); 1314 1315 dev->features |= GRE_FEATURES; 1316 dev->hw_features |= GRE_FEATURES; 1317 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1318 netif_keep_dst(dev); 1319 1320 return ip_tunnel_init(dev); 1321} 1322 1323static const struct net_device_ops erspan_netdev_ops = { 1324 .ndo_init = erspan_tunnel_init, 1325 .ndo_uninit = ip_tunnel_uninit, 1326 .ndo_start_xmit = erspan_xmit, 1327 .ndo_set_mac_address = eth_mac_addr, 1328 .ndo_validate_addr = eth_validate_addr, 1329 .ndo_change_mtu = ip_tunnel_change_mtu, 1330 .ndo_get_stats64 = dev_get_tstats64, 1331 .ndo_get_iflink = ip_tunnel_get_iflink, 1332 .ndo_fill_metadata_dst = gre_fill_metadata_dst, 1333}; 1334 1335static void ipgre_tap_setup(struct net_device *dev) 1336{ 1337 ether_setup(dev); 1338 dev->max_mtu = 0; 1339 dev->netdev_ops = &gre_tap_netdev_ops; 1340 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 1341 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1342 ip_tunnel_setup(dev, gre_tap_net_id); 1343} 1344 1345static int 1346ipgre_newlink_encap_setup(struct net_device *dev, struct nlattr *data[]) 1347{ 1348 struct ip_tunnel_encap ipencap; 1349 1350 if (ipgre_netlink_encap_parms(data, &ipencap)) { 1351 struct ip_tunnel *t = netdev_priv(dev); 1352 int err = ip_tunnel_encap_setup(t, &ipencap); 1353 1354 if (err < 0) 1355 return err; 1356 } 1357 1358 return 0; 1359} 1360 1361static int ipgre_newlink(struct net *src_net, struct net_device *dev, 1362 struct nlattr *tb[], struct nlattr *data[], 1363 struct netlink_ext_ack *extack) 1364{ 1365 struct ip_tunnel_parm p; 1366 __u32 fwmark = 0; 1367 int err; 1368 1369 err = ipgre_newlink_encap_setup(dev, data); 1370 if (err) 1371 return err; 1372 1373 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark); 1374 if (err < 0) 1375 return err; 1376 return ip_tunnel_newlink(dev, tb, &p, fwmark); 1377} 1378 1379static int erspan_newlink(struct net *src_net, struct net_device *dev, 1380 struct nlattr *tb[], struct nlattr *data[], 1381 struct netlink_ext_ack *extack) 1382{ 1383 struct ip_tunnel_parm p; 1384 __u32 fwmark = 0; 1385 int err; 1386 1387 err = ipgre_newlink_encap_setup(dev, data); 1388 if (err) 1389 return err; 1390 1391 err = erspan_netlink_parms(dev, data, tb, &p, &fwmark); 1392 if (err) 1393 return err; 1394 return ip_tunnel_newlink(dev, tb, &p, fwmark); 1395} 1396 1397static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[], 1398 struct nlattr *data[], 1399 struct netlink_ext_ack *extack) 1400{ 1401 struct ip_tunnel *t = netdev_priv(dev); 1402 __u32 fwmark = t->fwmark; 1403 struct ip_tunnel_parm p; 1404 int err; 1405 1406 err = ipgre_newlink_encap_setup(dev, data); 1407 if (err) 1408 return err; 1409 1410 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark); 1411 if (err < 0) 1412 return err; 1413 1414 err = ip_tunnel_changelink(dev, tb, &p, fwmark); 1415 if (err < 0) 1416 return err; 1417 1418 t->parms.i_flags = p.i_flags; 1419 t->parms.o_flags = p.o_flags; 1420 1421 ipgre_link_update(dev, !tb[IFLA_MTU]); 1422 1423 return 0; 1424} 1425 1426static int erspan_changelink(struct net_device *dev, struct nlattr *tb[], 1427 struct nlattr *data[], 1428 struct netlink_ext_ack *extack) 1429{ 1430 struct ip_tunnel *t = netdev_priv(dev); 1431 __u32 fwmark = t->fwmark; 1432 struct ip_tunnel_parm p; 1433 int err; 1434 1435 err = ipgre_newlink_encap_setup(dev, data); 1436 if (err) 1437 return err; 1438 1439 err = erspan_netlink_parms(dev, data, tb, &p, &fwmark); 1440 if (err < 0) 1441 return err; 1442 1443 err = ip_tunnel_changelink(dev, tb, &p, fwmark); 1444 if (err < 0) 1445 return err; 1446 1447 t->parms.i_flags = p.i_flags; 1448 t->parms.o_flags = p.o_flags; 1449 1450 return 0; 1451} 1452 1453static size_t ipgre_get_size(const struct net_device *dev) 1454{ 1455 return 1456 /* IFLA_GRE_LINK */ 1457 nla_total_size(4) + 1458 /* IFLA_GRE_IFLAGS */ 1459 nla_total_size(2) + 1460 /* IFLA_GRE_OFLAGS */ 1461 nla_total_size(2) + 1462 /* IFLA_GRE_IKEY */ 1463 nla_total_size(4) + 1464 /* IFLA_GRE_OKEY */ 1465 nla_total_size(4) + 1466 /* IFLA_GRE_LOCAL */ 1467 nla_total_size(4) + 1468 /* IFLA_GRE_REMOTE */ 1469 nla_total_size(4) + 1470 /* IFLA_GRE_TTL */ 1471 nla_total_size(1) + 1472 /* IFLA_GRE_TOS */ 1473 nla_total_size(1) + 1474 /* IFLA_GRE_PMTUDISC */ 1475 nla_total_size(1) + 1476 /* IFLA_GRE_ENCAP_TYPE */ 1477 nla_total_size(2) + 1478 /* IFLA_GRE_ENCAP_FLAGS */ 1479 nla_total_size(2) + 1480 /* IFLA_GRE_ENCAP_SPORT */ 1481 nla_total_size(2) + 1482 /* IFLA_GRE_ENCAP_DPORT */ 1483 nla_total_size(2) + 1484 /* IFLA_GRE_COLLECT_METADATA */ 1485 nla_total_size(0) + 1486 /* IFLA_GRE_IGNORE_DF */ 1487 nla_total_size(1) + 1488 /* IFLA_GRE_FWMARK */ 1489 nla_total_size(4) + 1490 /* IFLA_GRE_ERSPAN_INDEX */ 1491 nla_total_size(4) + 1492 /* IFLA_GRE_ERSPAN_VER */ 1493 nla_total_size(1) + 1494 /* IFLA_GRE_ERSPAN_DIR */ 1495 nla_total_size(1) + 1496 /* IFLA_GRE_ERSPAN_HWID */ 1497 nla_total_size(2) + 1498 0; 1499} 1500 1501static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev) 1502{ 1503 struct ip_tunnel *t = netdev_priv(dev); 1504 struct ip_tunnel_parm *p = &t->parms; 1505 __be16 o_flags = p->o_flags; 1506 1507 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) || 1508 nla_put_be16(skb, IFLA_GRE_IFLAGS, 1509 gre_tnl_flags_to_gre_flags(p->i_flags)) || 1510 nla_put_be16(skb, IFLA_GRE_OFLAGS, 1511 gre_tnl_flags_to_gre_flags(o_flags)) || 1512 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) || 1513 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) || 1514 nla_put_in_addr(skb, IFLA_GRE_LOCAL, p->iph.saddr) || 1515 nla_put_in_addr(skb, IFLA_GRE_REMOTE, p->iph.daddr) || 1516 nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) || 1517 nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) || 1518 nla_put_u8(skb, IFLA_GRE_PMTUDISC, 1519 !!(p->iph.frag_off & htons(IP_DF))) || 1520 nla_put_u32(skb, IFLA_GRE_FWMARK, t->fwmark)) 1521 goto nla_put_failure; 1522 1523 if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE, 1524 t->encap.type) || 1525 nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT, 1526 t->encap.sport) || 1527 nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT, 1528 t->encap.dport) || 1529 nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS, 1530 t->encap.flags)) 1531 goto nla_put_failure; 1532 1533 if (nla_put_u8(skb, IFLA_GRE_IGNORE_DF, t->ignore_df)) 1534 goto nla_put_failure; 1535 1536 if (t->collect_md) { 1537 if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA)) 1538 goto nla_put_failure; 1539 } 1540 1541 return 0; 1542 1543nla_put_failure: 1544 return -EMSGSIZE; 1545} 1546 1547static int erspan_fill_info(struct sk_buff *skb, const struct net_device *dev) 1548{ 1549 struct ip_tunnel *t = netdev_priv(dev); 1550 1551 if (t->erspan_ver <= 2) { 1552 if (t->erspan_ver != 0 && !t->collect_md) 1553 t->parms.o_flags |= TUNNEL_KEY; 1554 1555 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, t->erspan_ver)) 1556 goto nla_put_failure; 1557 1558 if (t->erspan_ver == 1) { 1559 if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, t->index)) 1560 goto nla_put_failure; 1561 } else if (t->erspan_ver == 2) { 1562 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, t->dir)) 1563 goto nla_put_failure; 1564 if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, t->hwid)) 1565 goto nla_put_failure; 1566 } 1567 } 1568 1569 return ipgre_fill_info(skb, dev); 1570 1571nla_put_failure: 1572 return -EMSGSIZE; 1573} 1574 1575static void erspan_setup(struct net_device *dev) 1576{ 1577 struct ip_tunnel *t = netdev_priv(dev); 1578 1579 ether_setup(dev); 1580 dev->max_mtu = 0; 1581 dev->netdev_ops = &erspan_netdev_ops; 1582 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 1583 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1584 ip_tunnel_setup(dev, erspan_net_id); 1585 t->erspan_ver = 1; 1586} 1587 1588static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = { 1589 [IFLA_GRE_LINK] = { .type = NLA_U32 }, 1590 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 }, 1591 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 }, 1592 [IFLA_GRE_IKEY] = { .type = NLA_U32 }, 1593 [IFLA_GRE_OKEY] = { .type = NLA_U32 }, 1594 [IFLA_GRE_LOCAL] = { .len = sizeof_field(struct iphdr, saddr) }, 1595 [IFLA_GRE_REMOTE] = { .len = sizeof_field(struct iphdr, daddr) }, 1596 [IFLA_GRE_TTL] = { .type = NLA_U8 }, 1597 [IFLA_GRE_TOS] = { .type = NLA_U8 }, 1598 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 }, 1599 [IFLA_GRE_ENCAP_TYPE] = { .type = NLA_U16 }, 1600 [IFLA_GRE_ENCAP_FLAGS] = { .type = NLA_U16 }, 1601 [IFLA_GRE_ENCAP_SPORT] = { .type = NLA_U16 }, 1602 [IFLA_GRE_ENCAP_DPORT] = { .type = NLA_U16 }, 1603 [IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG }, 1604 [IFLA_GRE_IGNORE_DF] = { .type = NLA_U8 }, 1605 [IFLA_GRE_FWMARK] = { .type = NLA_U32 }, 1606 [IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 }, 1607 [IFLA_GRE_ERSPAN_VER] = { .type = NLA_U8 }, 1608 [IFLA_GRE_ERSPAN_DIR] = { .type = NLA_U8 }, 1609 [IFLA_GRE_ERSPAN_HWID] = { .type = NLA_U16 }, 1610}; 1611 1612static struct rtnl_link_ops ipgre_link_ops __read_mostly = { 1613 .kind = "gre", 1614 .maxtype = IFLA_GRE_MAX, 1615 .policy = ipgre_policy, 1616 .priv_size = sizeof(struct ip_tunnel), 1617 .setup = ipgre_tunnel_setup, 1618 .validate = ipgre_tunnel_validate, 1619 .newlink = ipgre_newlink, 1620 .changelink = ipgre_changelink, 1621 .dellink = ip_tunnel_dellink, 1622 .get_size = ipgre_get_size, 1623 .fill_info = ipgre_fill_info, 1624 .get_link_net = ip_tunnel_get_link_net, 1625}; 1626 1627static struct rtnl_link_ops ipgre_tap_ops __read_mostly = { 1628 .kind = "gretap", 1629 .maxtype = IFLA_GRE_MAX, 1630 .policy = ipgre_policy, 1631 .priv_size = sizeof(struct ip_tunnel), 1632 .setup = ipgre_tap_setup, 1633 .validate = ipgre_tap_validate, 1634 .newlink = ipgre_newlink, 1635 .changelink = ipgre_changelink, 1636 .dellink = ip_tunnel_dellink, 1637 .get_size = ipgre_get_size, 1638 .fill_info = ipgre_fill_info, 1639 .get_link_net = ip_tunnel_get_link_net, 1640}; 1641 1642static struct rtnl_link_ops erspan_link_ops __read_mostly = { 1643 .kind = "erspan", 1644 .maxtype = IFLA_GRE_MAX, 1645 .policy = ipgre_policy, 1646 .priv_size = sizeof(struct ip_tunnel), 1647 .setup = erspan_setup, 1648 .validate = erspan_validate, 1649 .newlink = erspan_newlink, 1650 .changelink = erspan_changelink, 1651 .dellink = ip_tunnel_dellink, 1652 .get_size = ipgre_get_size, 1653 .fill_info = erspan_fill_info, 1654 .get_link_net = ip_tunnel_get_link_net, 1655}; 1656 1657struct net_device *gretap_fb_dev_create(struct net *net, const char *name, 1658 u8 name_assign_type) 1659{ 1660 struct nlattr *tb[IFLA_MAX + 1]; 1661 struct net_device *dev; 1662 LIST_HEAD(list_kill); 1663 struct ip_tunnel *t; 1664 int err; 1665 1666 memset(&tb, 0, sizeof(tb)); 1667 1668 dev = rtnl_create_link(net, name, name_assign_type, 1669 &ipgre_tap_ops, tb, NULL); 1670 if (IS_ERR(dev)) 1671 return dev; 1672 1673 /* Configure flow based GRE device. */ 1674 t = netdev_priv(dev); 1675 t->collect_md = true; 1676 1677 err = ipgre_newlink(net, dev, tb, NULL, NULL); 1678 if (err < 0) { 1679 free_netdev(dev); 1680 return ERR_PTR(err); 1681 } 1682 1683 /* openvswitch users expect packet sizes to be unrestricted, 1684 * so set the largest MTU we can. 1685 */ 1686 err = __ip_tunnel_change_mtu(dev, IP_MAX_MTU, false); 1687 if (err) 1688 goto out; 1689 1690 err = rtnl_configure_link(dev, NULL, 0, NULL); 1691 if (err < 0) 1692 goto out; 1693 1694 return dev; 1695out: 1696 ip_tunnel_dellink(dev, &list_kill); 1697 unregister_netdevice_many(&list_kill); 1698 return ERR_PTR(err); 1699} 1700EXPORT_SYMBOL_GPL(gretap_fb_dev_create); 1701 1702static int __net_init ipgre_tap_init_net(struct net *net) 1703{ 1704 return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, "gretap0"); 1705} 1706 1707static void __net_exit ipgre_tap_exit_batch_rtnl(struct list_head *list_net, 1708 struct list_head *dev_to_kill) 1709{ 1710 ip_tunnel_delete_nets(list_net, gre_tap_net_id, &ipgre_tap_ops, 1711 dev_to_kill); 1712} 1713 1714static struct pernet_operations ipgre_tap_net_ops = { 1715 .init = ipgre_tap_init_net, 1716 .exit_batch_rtnl = ipgre_tap_exit_batch_rtnl, 1717 .id = &gre_tap_net_id, 1718 .size = sizeof(struct ip_tunnel_net), 1719}; 1720 1721static int __net_init erspan_init_net(struct net *net) 1722{ 1723 return ip_tunnel_init_net(net, erspan_net_id, 1724 &erspan_link_ops, "erspan0"); 1725} 1726 1727static void __net_exit erspan_exit_batch_rtnl(struct list_head *net_list, 1728 struct list_head *dev_to_kill) 1729{ 1730 ip_tunnel_delete_nets(net_list, erspan_net_id, &erspan_link_ops, 1731 dev_to_kill); 1732} 1733 1734static struct pernet_operations erspan_net_ops = { 1735 .init = erspan_init_net, 1736 .exit_batch_rtnl = erspan_exit_batch_rtnl, 1737 .id = &erspan_net_id, 1738 .size = sizeof(struct ip_tunnel_net), 1739}; 1740 1741static int __init ipgre_init(void) 1742{ 1743 int err; 1744 1745 pr_info("GRE over IPv4 tunneling driver\n"); 1746 1747 err = register_pernet_device(&ipgre_net_ops); 1748 if (err < 0) 1749 return err; 1750 1751 err = register_pernet_device(&ipgre_tap_net_ops); 1752 if (err < 0) 1753 goto pnet_tap_failed; 1754 1755 err = register_pernet_device(&erspan_net_ops); 1756 if (err < 0) 1757 goto pnet_erspan_failed; 1758 1759 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO); 1760 if (err < 0) { 1761 pr_info("%s: can't add protocol\n", __func__); 1762 goto add_proto_failed; 1763 } 1764 1765 err = rtnl_link_register(&ipgre_link_ops); 1766 if (err < 0) 1767 goto rtnl_link_failed; 1768 1769 err = rtnl_link_register(&ipgre_tap_ops); 1770 if (err < 0) 1771 goto tap_ops_failed; 1772 1773 err = rtnl_link_register(&erspan_link_ops); 1774 if (err < 0) 1775 goto erspan_link_failed; 1776 1777 return 0; 1778 1779erspan_link_failed: 1780 rtnl_link_unregister(&ipgre_tap_ops); 1781tap_ops_failed: 1782 rtnl_link_unregister(&ipgre_link_ops); 1783rtnl_link_failed: 1784 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); 1785add_proto_failed: 1786 unregister_pernet_device(&erspan_net_ops); 1787pnet_erspan_failed: 1788 unregister_pernet_device(&ipgre_tap_net_ops); 1789pnet_tap_failed: 1790 unregister_pernet_device(&ipgre_net_ops); 1791 return err; 1792} 1793 1794static void __exit ipgre_fini(void) 1795{ 1796 rtnl_link_unregister(&ipgre_tap_ops); 1797 rtnl_link_unregister(&ipgre_link_ops); 1798 rtnl_link_unregister(&erspan_link_ops); 1799 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); 1800 unregister_pernet_device(&ipgre_tap_net_ops); 1801 unregister_pernet_device(&ipgre_net_ops); 1802 unregister_pernet_device(&erspan_net_ops); 1803} 1804 1805module_init(ipgre_init); 1806module_exit(ipgre_fini); 1807MODULE_DESCRIPTION("IPv4 GRE tunnels over IP library"); 1808MODULE_LICENSE("GPL"); 1809MODULE_ALIAS_RTNL_LINK("gre"); 1810MODULE_ALIAS_RTNL_LINK("gretap"); 1811MODULE_ALIAS_RTNL_LINK("erspan"); 1812MODULE_ALIAS_NETDEV("gre0"); 1813MODULE_ALIAS_NETDEV("gretap0"); 1814MODULE_ALIAS_NETDEV("erspan0"); 1815