1 /* 2 * Linux NET3: GRE over IP protocol decoder. 3 * 4 * Authors: Alexey Kuznetsov (kuznet@ms2.inr.ac.ru) 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 * 11 */ 12 13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 14 15 #include <linux/capability.h> 16 #include <linux/module.h> 17 #include <linux/types.h> 18 #include <linux/kernel.h> 19 #include <linux/slab.h> 20 #include <linux/uaccess.h> 21 #include <linux/skbuff.h> 22 #include <linux/netdevice.h> 23 #include <linux/in.h> 24 #include <linux/tcp.h> 25 #include <linux/udp.h> 26 #include <linux/if_arp.h> 27 #include <linux/if_vlan.h> 28 #include <linux/init.h> 29 #include <linux/in6.h> 30 #include <linux/inetdevice.h> 31 #include <linux/igmp.h> 32 #include <linux/netfilter_ipv4.h> 33 #include <linux/etherdevice.h> 34 #include <linux/if_ether.h> 35 36 #include <net/sock.h> 37 #include <net/ip.h> 38 #include <net/icmp.h> 39 #include <net/protocol.h> 40 #include <net/ip_tunnels.h> 41 #include <net/arp.h> 42 #include <net/checksum.h> 43 #include <net/dsfield.h> 44 #include <net/inet_ecn.h> 45 #include <net/xfrm.h> 46 #include <net/net_namespace.h> 47 #include <net/netns/generic.h> 48 #include <net/rtnetlink.h> 49 #include <net/gre.h> 50 #include <net/dst_metadata.h> 51 #include <net/erspan.h> 52 53 /* 54 Problems & solutions 55 -------------------- 56 57 1. The most important issue is detecting local dead loops. 58 They would cause complete host lockup in transmit, which 59 would be "resolved" by stack overflow or, if queueing is enabled, 60 with infinite looping in net_bh. 61 62 We cannot track such dead loops during route installation, 63 it is infeasible task. The most general solutions would be 64 to keep skb->encapsulation counter (sort of local ttl), 65 and silently drop packet when it expires. It is a good 66 solution, but it supposes maintaining new variable in ALL 67 skb, even if no tunneling is used. 68 69 Current solution: xmit_recursion breaks dead loops. This is a percpu 70 counter, since when we enter the first ndo_xmit(), cpu migration is 71 forbidden. We force an exit if this counter reaches RECURSION_LIMIT 72 73 2. Networking dead loops would not kill routers, but would really 74 kill network. IP hop limit plays role of "t->recursion" in this case, 75 if we copy it from packet being encapsulated to upper header. 76 It is very good solution, but it introduces two problems: 77 78 - Routing protocols, using packets with ttl=1 (OSPF, RIP2), 79 do not work over tunnels. 80 - traceroute does not work. I planned to relay ICMP from tunnel, 81 so that this problem would be solved and traceroute output 82 would even more informative. This idea appeared to be wrong: 83 only Linux complies to rfc1812 now (yes, guys, Linux is the only 84 true router now :-)), all routers (at least, in neighbourhood of mine) 85 return only 8 bytes of payload. It is the end. 86 87 Hence, if we want that OSPF worked or traceroute said something reasonable, 88 we should search for another solution. 89 90 One of them is to parse packet trying to detect inner encapsulation 91 made by our node. It is difficult or even impossible, especially, 92 taking into account fragmentation. TO be short, ttl is not solution at all. 93 94 Current solution: The solution was UNEXPECTEDLY SIMPLE. 95 We force DF flag on tunnels with preconfigured hop limit, 96 that is ALL. :-) Well, it does not remove the problem completely, 97 but exponential growth of network traffic is changed to linear 98 (branches, that exceed pmtu are pruned) and tunnel mtu 99 rapidly degrades to value <68, where looping stops. 100 Yes, it is not good if there exists a router in the loop, 101 which does not force DF, even when encapsulating packets have DF set. 102 But it is not our problem! Nobody could accuse us, we made 103 all that we could make. Even if it is your gated who injected 104 fatal route to network, even if it were you who configured 105 fatal static route: you are innocent. :-) 106 107 Alexey Kuznetsov. 108 */ 109 110 static bool log_ecn_error = true; 111 module_param(log_ecn_error, bool, 0644); 112 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN"); 113 114 static struct rtnl_link_ops ipgre_link_ops __read_mostly; 115 static int ipgre_tunnel_init(struct net_device *dev); 116 static void erspan_build_header(struct sk_buff *skb, 117 u32 id, u32 index, 118 bool truncate, bool is_ipv4); 119 120 static unsigned int ipgre_net_id __read_mostly; 121 static unsigned int gre_tap_net_id __read_mostly; 122 static unsigned int erspan_net_id __read_mostly; 123 124 static void ipgre_err(struct sk_buff *skb, u32 info, 125 const struct tnl_ptk_info *tpi) 126 { 127 128 /* All the routers (except for Linux) return only 129 8 bytes of packet payload. It means, that precise relaying of 130 ICMP in the real Internet is absolutely infeasible. 131 132 Moreover, Cisco "wise men" put GRE key to the third word 133 in GRE header. It makes impossible maintaining even soft 134 state for keyed GRE tunnels with enabled checksum. Tell 135 them "thank you". 136 137 Well, I wonder, rfc1812 was written by Cisco employee, 138 what the hell these idiots break standards established 139 by themselves??? 140 */ 141 struct net *net = dev_net(skb->dev); 142 struct ip_tunnel_net *itn; 143 const struct iphdr *iph; 144 const int type = icmp_hdr(skb)->type; 145 const int code = icmp_hdr(skb)->code; 146 unsigned int data_len = 0; 147 struct ip_tunnel *t; 148 149 switch (type) { 150 default: 151 case ICMP_PARAMETERPROB: 152 return; 153 154 case ICMP_DEST_UNREACH: 155 switch (code) { 156 case ICMP_SR_FAILED: 157 case ICMP_PORT_UNREACH: 158 /* Impossible event. */ 159 return; 160 default: 161 /* All others are translated to HOST_UNREACH. 162 rfc2003 contains "deep thoughts" about NET_UNREACH, 163 I believe they are just ether pollution. --ANK 164 */ 165 break; 166 } 167 break; 168 169 case ICMP_TIME_EXCEEDED: 170 if (code != ICMP_EXC_TTL) 171 return; 172 data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */ 173 break; 174 175 case ICMP_REDIRECT: 176 break; 177 } 178 179 if (tpi->proto == htons(ETH_P_TEB)) 180 itn = net_generic(net, gre_tap_net_id); 181 else 182 itn = net_generic(net, ipgre_net_id); 183 184 iph = (const struct iphdr *)(icmp_hdr(skb) + 1); 185 t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags, 186 iph->daddr, iph->saddr, tpi->key); 187 188 if (!t) 189 return; 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; 196 #endif 197 198 if (t->parms.iph.daddr == 0 || 199 ipv4_is_multicast(t->parms.iph.daddr)) 200 return; 201 202 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 203 return; 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 } 211 212 static void gre_err(struct sk_buff *skb, u32 info) 213 { 214 /* All the routers (except for Linux) return only 215 * 8 bytes of packet payload. It means, that precise relaying of 216 * ICMP in the real Internet is absolutely infeasible. 217 * 218 * Moreover, Cisco "wise men" put GRE key to the third word 219 * in GRE header. It makes impossible maintaining even soft 220 * state for keyed 221 * GRE tunnels with enabled checksum. Tell them "thank you". 222 * 223 * Well, I wonder, rfc1812 was written by Cisco employee, 224 * what the hell these idiots break standards established 225 * by themselves??? 226 */ 227 228 const struct iphdr *iph = (struct iphdr *)skb->data; 229 const int type = icmp_hdr(skb)->type; 230 const int code = icmp_hdr(skb)->code; 231 struct tnl_ptk_info tpi; 232 bool csum_err = false; 233 234 if (gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IP), 235 iph->ihl * 4) < 0) { 236 if (!csum_err) /* ignore csum errors. */ 237 return; 238 } 239 240 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { 241 ipv4_update_pmtu(skb, dev_net(skb->dev), info, 242 skb->dev->ifindex, 0, IPPROTO_GRE, 0); 243 return; 244 } 245 if (type == ICMP_REDIRECT) { 246 ipv4_redirect(skb, dev_net(skb->dev), skb->dev->ifindex, 0, 247 IPPROTO_GRE, 0); 248 return; 249 } 250 251 ipgre_err(skb, info, &tpi); 252 } 253 254 static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi, 255 int gre_hdr_len) 256 { 257 struct net *net = dev_net(skb->dev); 258 struct metadata_dst *tun_dst = NULL; 259 struct erspan_base_hdr *ershdr; 260 struct erspan_metadata *pkt_md; 261 struct ip_tunnel_net *itn; 262 struct ip_tunnel *tunnel; 263 const struct iphdr *iph; 264 struct erspan_md2 *md2; 265 int ver; 266 int len; 267 268 itn = net_generic(net, erspan_net_id); 269 len = gre_hdr_len + sizeof(*ershdr); 270 271 /* Check based hdr len */ 272 if (unlikely(!pskb_may_pull(skb, len))) 273 return PACKET_REJECT; 274 275 iph = ip_hdr(skb); 276 ershdr = (struct erspan_base_hdr *)(skb->data + gre_hdr_len); 277 ver = ershdr->ver; 278 279 /* The original GRE header does not have key field, 280 * Use ERSPAN 10-bit session ID as key. 281 */ 282 tpi->key = cpu_to_be32(get_session_id(ershdr)); 283 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, 284 tpi->flags | TUNNEL_KEY, 285 iph->saddr, iph->daddr, tpi->key); 286 287 if (tunnel) { 288 len = gre_hdr_len + erspan_hdr_len(ver); 289 if (unlikely(!pskb_may_pull(skb, len))) 290 return PACKET_REJECT; 291 292 ershdr = (struct erspan_base_hdr *)(skb->data + gre_hdr_len); 293 pkt_md = (struct erspan_metadata *)(ershdr + 1); 294 295 if (__iptunnel_pull_header(skb, 296 len, 297 htons(ETH_P_TEB), 298 false, false) < 0) 299 goto drop; 300 301 if (tunnel->collect_md) { 302 struct ip_tunnel_info *info; 303 struct erspan_metadata *md; 304 __be64 tun_id; 305 __be16 flags; 306 307 tpi->flags |= TUNNEL_KEY; 308 flags = tpi->flags; 309 tun_id = key32_to_tunnel_id(tpi->key); 310 311 tun_dst = ip_tun_rx_dst(skb, flags, 312 tun_id, sizeof(*md)); 313 if (!tun_dst) 314 return PACKET_REJECT; 315 316 md = ip_tunnel_info_opts(&tun_dst->u.tun_info); 317 md->version = ver; 318 md2 = &md->u.md2; 319 memcpy(md2, pkt_md, ver == 1 ? ERSPAN_V1_MDSIZE : 320 ERSPAN_V2_MDSIZE); 321 322 info = &tun_dst->u.tun_info; 323 info->key.tun_flags |= TUNNEL_ERSPAN_OPT; 324 info->options_len = sizeof(*md); 325 } 326 327 skb_reset_mac_header(skb); 328 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error); 329 return PACKET_RCVD; 330 } 331 drop: 332 kfree_skb(skb); 333 return PACKET_RCVD; 334 } 335 336 static int __ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi, 337 struct ip_tunnel_net *itn, int hdr_len, bool raw_proto) 338 { 339 struct metadata_dst *tun_dst = NULL; 340 const struct iphdr *iph; 341 struct ip_tunnel *tunnel; 342 343 iph = ip_hdr(skb); 344 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags, 345 iph->saddr, iph->daddr, tpi->key); 346 347 if (tunnel) { 348 if (__iptunnel_pull_header(skb, hdr_len, tpi->proto, 349 raw_proto, false) < 0) 350 goto drop; 351 352 if (tunnel->dev->type != ARPHRD_NONE) 353 skb_pop_mac_header(skb); 354 else 355 skb_reset_mac_header(skb); 356 if (tunnel->collect_md) { 357 __be16 flags; 358 __be64 tun_id; 359 360 flags = tpi->flags & (TUNNEL_CSUM | TUNNEL_KEY); 361 tun_id = key32_to_tunnel_id(tpi->key); 362 tun_dst = ip_tun_rx_dst(skb, flags, tun_id, 0); 363 if (!tun_dst) 364 return PACKET_REJECT; 365 } 366 367 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error); 368 return PACKET_RCVD; 369 } 370 return PACKET_NEXT; 371 372 drop: 373 kfree_skb(skb); 374 return PACKET_RCVD; 375 } 376 377 static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi, 378 int hdr_len) 379 { 380 struct net *net = dev_net(skb->dev); 381 struct ip_tunnel_net *itn; 382 int res; 383 384 if (tpi->proto == htons(ETH_P_TEB)) 385 itn = net_generic(net, gre_tap_net_id); 386 else 387 itn = net_generic(net, ipgre_net_id); 388 389 res = __ipgre_rcv(skb, tpi, itn, hdr_len, false); 390 if (res == PACKET_NEXT && tpi->proto == htons(ETH_P_TEB)) { 391 /* ipgre tunnels in collect metadata mode should receive 392 * also ETH_P_TEB traffic. 393 */ 394 itn = net_generic(net, ipgre_net_id); 395 res = __ipgre_rcv(skb, tpi, itn, hdr_len, true); 396 } 397 return res; 398 } 399 400 static int gre_rcv(struct sk_buff *skb) 401 { 402 struct tnl_ptk_info tpi; 403 bool csum_err = false; 404 int hdr_len; 405 406 #ifdef CONFIG_NET_IPGRE_BROADCAST 407 if (ipv4_is_multicast(ip_hdr(skb)->daddr)) { 408 /* Looped back packet, drop it! */ 409 if (rt_is_output_route(skb_rtable(skb))) 410 goto drop; 411 } 412 #endif 413 414 hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IP), 0); 415 if (hdr_len < 0) 416 goto drop; 417 418 if (unlikely(tpi.proto == htons(ETH_P_ERSPAN) || 419 tpi.proto == htons(ETH_P_ERSPAN2))) { 420 if (erspan_rcv(skb, &tpi, hdr_len) == PACKET_RCVD) 421 return 0; 422 goto out; 423 } 424 425 if (ipgre_rcv(skb, &tpi, hdr_len) == PACKET_RCVD) 426 return 0; 427 428 out: 429 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 430 drop: 431 kfree_skb(skb); 432 return 0; 433 } 434 435 static void __gre_xmit(struct sk_buff *skb, struct net_device *dev, 436 const struct iphdr *tnl_params, 437 __be16 proto) 438 { 439 struct ip_tunnel *tunnel = netdev_priv(dev); 440 441 if (tunnel->parms.o_flags & TUNNEL_SEQ) 442 tunnel->o_seqno++; 443 444 /* Push GRE header. */ 445 gre_build_header(skb, tunnel->tun_hlen, 446 tunnel->parms.o_flags, proto, tunnel->parms.o_key, 447 htonl(tunnel->o_seqno)); 448 449 ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol); 450 } 451 452 static int gre_handle_offloads(struct sk_buff *skb, bool csum) 453 { 454 return iptunnel_handle_offloads(skb, csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE); 455 } 456 457 static struct rtable *gre_get_rt(struct sk_buff *skb, 458 struct net_device *dev, 459 struct flowi4 *fl, 460 const struct ip_tunnel_key *key) 461 { 462 struct net *net = dev_net(dev); 463 464 memset(fl, 0, sizeof(*fl)); 465 fl->daddr = key->u.ipv4.dst; 466 fl->saddr = key->u.ipv4.src; 467 fl->flowi4_tos = RT_TOS(key->tos); 468 fl->flowi4_mark = skb->mark; 469 fl->flowi4_proto = IPPROTO_GRE; 470 471 return ip_route_output_key(net, fl); 472 } 473 474 static struct rtable *prepare_fb_xmit(struct sk_buff *skb, 475 struct net_device *dev, 476 struct flowi4 *fl, 477 int tunnel_hlen) 478 { 479 struct ip_tunnel_info *tun_info; 480 const struct ip_tunnel_key *key; 481 struct rtable *rt = NULL; 482 int min_headroom; 483 bool use_cache; 484 int err; 485 486 tun_info = skb_tunnel_info(skb); 487 key = &tun_info->key; 488 use_cache = ip_tunnel_dst_cache_usable(skb, tun_info); 489 490 if (use_cache) 491 rt = dst_cache_get_ip4(&tun_info->dst_cache, &fl->saddr); 492 if (!rt) { 493 rt = gre_get_rt(skb, dev, fl, key); 494 if (IS_ERR(rt)) 495 goto err_free_skb; 496 if (use_cache) 497 dst_cache_set_ip4(&tun_info->dst_cache, &rt->dst, 498 fl->saddr); 499 } 500 501 min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len 502 + tunnel_hlen + sizeof(struct iphdr); 503 if (skb_headroom(skb) < min_headroom || skb_header_cloned(skb)) { 504 int head_delta = SKB_DATA_ALIGN(min_headroom - 505 skb_headroom(skb) + 506 16); 507 err = pskb_expand_head(skb, max_t(int, head_delta, 0), 508 0, GFP_ATOMIC); 509 if (unlikely(err)) 510 goto err_free_rt; 511 } 512 return rt; 513 514 err_free_rt: 515 ip_rt_put(rt); 516 err_free_skb: 517 kfree_skb(skb); 518 dev->stats.tx_dropped++; 519 return NULL; 520 } 521 522 static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev, 523 __be16 proto) 524 { 525 struct ip_tunnel *tunnel = netdev_priv(dev); 526 struct ip_tunnel_info *tun_info; 527 const struct ip_tunnel_key *key; 528 struct rtable *rt = NULL; 529 struct flowi4 fl; 530 int tunnel_hlen; 531 __be16 df, flags; 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 tunnel_hlen = gre_calc_hlen(key->tun_flags); 540 541 rt = prepare_fb_xmit(skb, dev, &fl, tunnel_hlen); 542 if (!rt) 543 return; 544 545 /* Push Tunnel header. */ 546 if (gre_handle_offloads(skb, !!(tun_info->key.tun_flags & TUNNEL_CSUM))) 547 goto err_free_rt; 548 549 flags = tun_info->key.tun_flags & 550 (TUNNEL_CSUM | TUNNEL_KEY | TUNNEL_SEQ); 551 gre_build_header(skb, tunnel_hlen, flags, proto, 552 tunnel_id_to_key32(tun_info->key.tun_id), 553 (flags & TUNNEL_SEQ) ? htonl(tunnel->o_seqno++) : 0); 554 555 df = key->tun_flags & TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0; 556 557 iptunnel_xmit(skb->sk, rt, skb, fl.saddr, key->u.ipv4.dst, IPPROTO_GRE, 558 key->tos, key->ttl, df, false); 559 return; 560 561 err_free_rt: 562 ip_rt_put(rt); 563 err_free_skb: 564 kfree_skb(skb); 565 dev->stats.tx_dropped++; 566 } 567 568 static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev, 569 __be16 proto) 570 { 571 struct ip_tunnel *tunnel = netdev_priv(dev); 572 struct ip_tunnel_info *tun_info; 573 const struct ip_tunnel_key *key; 574 struct erspan_metadata *md; 575 struct rtable *rt = NULL; 576 bool truncate = false; 577 struct flowi4 fl; 578 int tunnel_hlen; 579 int version; 580 __be16 df; 581 int nhoff; 582 int thoff; 583 584 tun_info = skb_tunnel_info(skb); 585 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) || 586 ip_tunnel_info_af(tun_info) != AF_INET)) 587 goto err_free_skb; 588 589 key = &tun_info->key; 590 md = ip_tunnel_info_opts(tun_info); 591 if (!md) 592 goto err_free_rt; 593 594 /* ERSPAN has fixed 8 byte GRE header */ 595 version = md->version; 596 tunnel_hlen = 8 + erspan_hdr_len(version); 597 598 rt = prepare_fb_xmit(skb, dev, &fl, tunnel_hlen); 599 if (!rt) 600 return; 601 602 if (gre_handle_offloads(skb, false)) 603 goto err_free_rt; 604 605 if (skb->len > dev->mtu + dev->hard_header_len) { 606 pskb_trim(skb, dev->mtu + dev->hard_header_len); 607 truncate = true; 608 } 609 610 nhoff = skb_network_header(skb) - skb_mac_header(skb); 611 if (skb->protocol == htons(ETH_P_IP) && 612 (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff)) 613 truncate = true; 614 615 thoff = skb_transport_header(skb) - skb_mac_header(skb); 616 if (skb->protocol == htons(ETH_P_IPV6) && 617 (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff)) 618 truncate = true; 619 620 if (version == 1) { 621 erspan_build_header(skb, ntohl(tunnel_id_to_key32(key->tun_id)), 622 ntohl(md->u.index), truncate, true); 623 } else if (version == 2) { 624 erspan_build_header_v2(skb, 625 ntohl(tunnel_id_to_key32(key->tun_id)), 626 md->u.md2.dir, 627 get_hwid(&md->u.md2), 628 truncate, true); 629 } else { 630 goto err_free_rt; 631 } 632 633 gre_build_header(skb, 8, TUNNEL_SEQ, 634 htons(ETH_P_ERSPAN), 0, htonl(tunnel->o_seqno++)); 635 636 df = key->tun_flags & TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0; 637 638 iptunnel_xmit(skb->sk, rt, skb, fl.saddr, key->u.ipv4.dst, IPPROTO_GRE, 639 key->tos, key->ttl, df, false); 640 return; 641 642 err_free_rt: 643 ip_rt_put(rt); 644 err_free_skb: 645 kfree_skb(skb); 646 dev->stats.tx_dropped++; 647 } 648 649 static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb) 650 { 651 struct ip_tunnel_info *info = skb_tunnel_info(skb); 652 struct rtable *rt; 653 struct flowi4 fl4; 654 655 if (ip_tunnel_info_af(info) != AF_INET) 656 return -EINVAL; 657 658 rt = gre_get_rt(skb, dev, &fl4, &info->key); 659 if (IS_ERR(rt)) 660 return PTR_ERR(rt); 661 662 ip_rt_put(rt); 663 info->key.u.ipv4.src = fl4.saddr; 664 return 0; 665 } 666 667 static netdev_tx_t ipgre_xmit(struct sk_buff *skb, 668 struct net_device *dev) 669 { 670 struct ip_tunnel *tunnel = netdev_priv(dev); 671 const struct iphdr *tnl_params; 672 673 if (tunnel->collect_md) { 674 gre_fb_xmit(skb, dev, skb->protocol); 675 return NETDEV_TX_OK; 676 } 677 678 if (dev->header_ops) { 679 /* Need space for new headers */ 680 if (skb_cow_head(skb, dev->needed_headroom - 681 (tunnel->hlen + sizeof(struct iphdr)))) 682 goto free_skb; 683 684 tnl_params = (const struct iphdr *)skb->data; 685 686 /* Pull skb since ip_tunnel_xmit() needs skb->data pointing 687 * to gre header. 688 */ 689 skb_pull(skb, tunnel->hlen + sizeof(struct iphdr)); 690 skb_reset_mac_header(skb); 691 } else { 692 if (skb_cow_head(skb, dev->needed_headroom)) 693 goto free_skb; 694 695 tnl_params = &tunnel->parms.iph; 696 } 697 698 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM))) 699 goto free_skb; 700 701 __gre_xmit(skb, dev, tnl_params, skb->protocol); 702 return NETDEV_TX_OK; 703 704 free_skb: 705 kfree_skb(skb); 706 dev->stats.tx_dropped++; 707 return NETDEV_TX_OK; 708 } 709 710 static netdev_tx_t erspan_xmit(struct sk_buff *skb, 711 struct net_device *dev) 712 { 713 struct ip_tunnel *tunnel = netdev_priv(dev); 714 bool truncate = false; 715 716 if (tunnel->collect_md) { 717 erspan_fb_xmit(skb, dev, skb->protocol); 718 return NETDEV_TX_OK; 719 } 720 721 if (gre_handle_offloads(skb, false)) 722 goto free_skb; 723 724 if (skb_cow_head(skb, dev->needed_headroom)) 725 goto free_skb; 726 727 if (skb->len > dev->mtu + dev->hard_header_len) { 728 pskb_trim(skb, dev->mtu + dev->hard_header_len); 729 truncate = true; 730 } 731 732 /* Push ERSPAN header */ 733 if (tunnel->erspan_ver == 1) 734 erspan_build_header(skb, ntohl(tunnel->parms.o_key), 735 tunnel->index, 736 truncate, true); 737 else 738 erspan_build_header_v2(skb, ntohl(tunnel->parms.o_key), 739 tunnel->dir, tunnel->hwid, 740 truncate, true); 741 742 tunnel->parms.o_flags &= ~TUNNEL_KEY; 743 __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_ERSPAN)); 744 return NETDEV_TX_OK; 745 746 free_skb: 747 kfree_skb(skb); 748 dev->stats.tx_dropped++; 749 return NETDEV_TX_OK; 750 } 751 752 static netdev_tx_t gre_tap_xmit(struct sk_buff *skb, 753 struct net_device *dev) 754 { 755 struct ip_tunnel *tunnel = netdev_priv(dev); 756 757 if (tunnel->collect_md) { 758 gre_fb_xmit(skb, dev, htons(ETH_P_TEB)); 759 return NETDEV_TX_OK; 760 } 761 762 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM))) 763 goto free_skb; 764 765 if (skb_cow_head(skb, dev->needed_headroom)) 766 goto free_skb; 767 768 __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB)); 769 return NETDEV_TX_OK; 770 771 free_skb: 772 kfree_skb(skb); 773 dev->stats.tx_dropped++; 774 return NETDEV_TX_OK; 775 } 776 777 static void ipgre_link_update(struct net_device *dev, bool set_mtu) 778 { 779 struct ip_tunnel *tunnel = netdev_priv(dev); 780 int len; 781 782 len = tunnel->tun_hlen; 783 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags); 784 len = tunnel->tun_hlen - len; 785 tunnel->hlen = tunnel->hlen + len; 786 787 dev->needed_headroom = dev->needed_headroom + len; 788 if (set_mtu) 789 dev->mtu = max_t(int, dev->mtu - len, 68); 790 791 if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) { 792 if (!(tunnel->parms.o_flags & TUNNEL_CSUM) || 793 tunnel->encap.type == TUNNEL_ENCAP_NONE) { 794 dev->features |= NETIF_F_GSO_SOFTWARE; 795 dev->hw_features |= NETIF_F_GSO_SOFTWARE; 796 } else { 797 dev->features &= ~NETIF_F_GSO_SOFTWARE; 798 dev->hw_features &= ~NETIF_F_GSO_SOFTWARE; 799 } 800 dev->features |= NETIF_F_LLTX; 801 } else { 802 dev->hw_features &= ~NETIF_F_GSO_SOFTWARE; 803 dev->features &= ~(NETIF_F_LLTX | NETIF_F_GSO_SOFTWARE); 804 } 805 } 806 807 static int ipgre_tunnel_ioctl(struct net_device *dev, 808 struct ifreq *ifr, int cmd) 809 { 810 struct ip_tunnel_parm p; 811 int err; 812 813 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 814 return -EFAULT; 815 816 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) { 817 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE || 818 p.iph.ihl != 5 || (p.iph.frag_off & htons(~IP_DF)) || 819 ((p.i_flags | p.o_flags) & (GRE_VERSION | GRE_ROUTING))) 820 return -EINVAL; 821 } 822 823 p.i_flags = gre_flags_to_tnl_flags(p.i_flags); 824 p.o_flags = gre_flags_to_tnl_flags(p.o_flags); 825 826 err = ip_tunnel_ioctl(dev, &p, cmd); 827 if (err) 828 return err; 829 830 if (cmd == SIOCCHGTUNNEL) { 831 struct ip_tunnel *t = netdev_priv(dev); 832 833 t->parms.i_flags = p.i_flags; 834 t->parms.o_flags = p.o_flags; 835 836 if (strcmp(dev->rtnl_link_ops->kind, "erspan")) 837 ipgre_link_update(dev, true); 838 } 839 840 p.i_flags = gre_tnl_flags_to_gre_flags(p.i_flags); 841 p.o_flags = gre_tnl_flags_to_gre_flags(p.o_flags); 842 843 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 844 return -EFAULT; 845 846 return 0; 847 } 848 849 /* Nice toy. Unfortunately, useless in real life :-) 850 It allows to construct virtual multiprotocol broadcast "LAN" 851 over the Internet, provided multicast routing is tuned. 852 853 854 I have no idea was this bicycle invented before me, 855 so that I had to set ARPHRD_IPGRE to a random value. 856 I have an impression, that Cisco could make something similar, 857 but this feature is apparently missing in IOS<=11.2(8). 858 859 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks 860 with broadcast 224.66.66.66. If you have access to mbone, play with me :-) 861 862 ping -t 255 224.66.66.66 863 864 If nobody answers, mbone does not work. 865 866 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255 867 ip addr add 10.66.66.<somewhat>/24 dev Universe 868 ifconfig Universe up 869 ifconfig Universe add fe80::<Your_real_addr>/10 870 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96 871 ftp 10.66.66.66 872 ... 873 ftp fec0:6666:6666::193.233.7.65 874 ... 875 */ 876 static int ipgre_header(struct sk_buff *skb, struct net_device *dev, 877 unsigned short type, 878 const void *daddr, const void *saddr, unsigned int len) 879 { 880 struct ip_tunnel *t = netdev_priv(dev); 881 struct iphdr *iph; 882 struct gre_base_hdr *greh; 883 884 iph = skb_push(skb, t->hlen + sizeof(*iph)); 885 greh = (struct gre_base_hdr *)(iph+1); 886 greh->flags = gre_tnl_flags_to_gre_flags(t->parms.o_flags); 887 greh->protocol = htons(type); 888 889 memcpy(iph, &t->parms.iph, sizeof(struct iphdr)); 890 891 /* Set the source hardware address. */ 892 if (saddr) 893 memcpy(&iph->saddr, saddr, 4); 894 if (daddr) 895 memcpy(&iph->daddr, daddr, 4); 896 if (iph->daddr) 897 return t->hlen + sizeof(*iph); 898 899 return -(t->hlen + sizeof(*iph)); 900 } 901 902 static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr) 903 { 904 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb); 905 memcpy(haddr, &iph->saddr, 4); 906 return 4; 907 } 908 909 static const struct header_ops ipgre_header_ops = { 910 .create = ipgre_header, 911 .parse = ipgre_header_parse, 912 }; 913 914 #ifdef CONFIG_NET_IPGRE_BROADCAST 915 static int ipgre_open(struct net_device *dev) 916 { 917 struct ip_tunnel *t = netdev_priv(dev); 918 919 if (ipv4_is_multicast(t->parms.iph.daddr)) { 920 struct flowi4 fl4; 921 struct rtable *rt; 922 923 rt = ip_route_output_gre(t->net, &fl4, 924 t->parms.iph.daddr, 925 t->parms.iph.saddr, 926 t->parms.o_key, 927 RT_TOS(t->parms.iph.tos), 928 t->parms.link); 929 if (IS_ERR(rt)) 930 return -EADDRNOTAVAIL; 931 dev = rt->dst.dev; 932 ip_rt_put(rt); 933 if (!__in_dev_get_rtnl(dev)) 934 return -EADDRNOTAVAIL; 935 t->mlink = dev->ifindex; 936 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr); 937 } 938 return 0; 939 } 940 941 static int ipgre_close(struct net_device *dev) 942 { 943 struct ip_tunnel *t = netdev_priv(dev); 944 945 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) { 946 struct in_device *in_dev; 947 in_dev = inetdev_by_index(t->net, t->mlink); 948 if (in_dev) 949 ip_mc_dec_group(in_dev, t->parms.iph.daddr); 950 } 951 return 0; 952 } 953 #endif 954 955 static const struct net_device_ops ipgre_netdev_ops = { 956 .ndo_init = ipgre_tunnel_init, 957 .ndo_uninit = ip_tunnel_uninit, 958 #ifdef CONFIG_NET_IPGRE_BROADCAST 959 .ndo_open = ipgre_open, 960 .ndo_stop = ipgre_close, 961 #endif 962 .ndo_start_xmit = ipgre_xmit, 963 .ndo_do_ioctl = ipgre_tunnel_ioctl, 964 .ndo_change_mtu = ip_tunnel_change_mtu, 965 .ndo_get_stats64 = ip_tunnel_get_stats64, 966 .ndo_get_iflink = ip_tunnel_get_iflink, 967 }; 968 969 #define GRE_FEATURES (NETIF_F_SG | \ 970 NETIF_F_FRAGLIST | \ 971 NETIF_F_HIGHDMA | \ 972 NETIF_F_HW_CSUM) 973 974 static void ipgre_tunnel_setup(struct net_device *dev) 975 { 976 dev->netdev_ops = &ipgre_netdev_ops; 977 dev->type = ARPHRD_IPGRE; 978 ip_tunnel_setup(dev, ipgre_net_id); 979 } 980 981 static void __gre_tunnel_init(struct net_device *dev) 982 { 983 struct ip_tunnel *tunnel; 984 int t_hlen; 985 986 tunnel = netdev_priv(dev); 987 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags); 988 tunnel->parms.iph.protocol = IPPROTO_GRE; 989 990 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen; 991 992 t_hlen = tunnel->hlen + sizeof(struct iphdr); 993 994 dev->features |= GRE_FEATURES; 995 dev->hw_features |= GRE_FEATURES; 996 997 if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) { 998 /* TCP offload with GRE SEQ is not supported, nor 999 * can we support 2 levels of outer headers requiring 1000 * an update. 1001 */ 1002 if (!(tunnel->parms.o_flags & TUNNEL_CSUM) || 1003 (tunnel->encap.type == TUNNEL_ENCAP_NONE)) { 1004 dev->features |= NETIF_F_GSO_SOFTWARE; 1005 dev->hw_features |= NETIF_F_GSO_SOFTWARE; 1006 } 1007 1008 /* Can use a lockless transmit, unless we generate 1009 * output sequences 1010 */ 1011 dev->features |= NETIF_F_LLTX; 1012 } 1013 } 1014 1015 static int ipgre_tunnel_init(struct net_device *dev) 1016 { 1017 struct ip_tunnel *tunnel = netdev_priv(dev); 1018 struct iphdr *iph = &tunnel->parms.iph; 1019 1020 __gre_tunnel_init(dev); 1021 1022 memcpy(dev->dev_addr, &iph->saddr, 4); 1023 memcpy(dev->broadcast, &iph->daddr, 4); 1024 1025 dev->flags = IFF_NOARP; 1026 netif_keep_dst(dev); 1027 dev->addr_len = 4; 1028 1029 if (iph->daddr && !tunnel->collect_md) { 1030 #ifdef CONFIG_NET_IPGRE_BROADCAST 1031 if (ipv4_is_multicast(iph->daddr)) { 1032 if (!iph->saddr) 1033 return -EINVAL; 1034 dev->flags = IFF_BROADCAST; 1035 dev->header_ops = &ipgre_header_ops; 1036 } 1037 #endif 1038 } else if (!tunnel->collect_md) { 1039 dev->header_ops = &ipgre_header_ops; 1040 } 1041 1042 return ip_tunnel_init(dev); 1043 } 1044 1045 static const struct gre_protocol ipgre_protocol = { 1046 .handler = gre_rcv, 1047 .err_handler = gre_err, 1048 }; 1049 1050 static int __net_init ipgre_init_net(struct net *net) 1051 { 1052 return ip_tunnel_init_net(net, ipgre_net_id, &ipgre_link_ops, NULL); 1053 } 1054 1055 static void __net_exit ipgre_exit_batch_net(struct list_head *list_net) 1056 { 1057 ip_tunnel_delete_nets(list_net, ipgre_net_id, &ipgre_link_ops); 1058 } 1059 1060 static struct pernet_operations ipgre_net_ops = { 1061 .init = ipgre_init_net, 1062 .exit_batch = ipgre_exit_batch_net, 1063 .id = &ipgre_net_id, 1064 .size = sizeof(struct ip_tunnel_net), 1065 }; 1066 1067 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[], 1068 struct netlink_ext_ack *extack) 1069 { 1070 __be16 flags; 1071 1072 if (!data) 1073 return 0; 1074 1075 flags = 0; 1076 if (data[IFLA_GRE_IFLAGS]) 1077 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); 1078 if (data[IFLA_GRE_OFLAGS]) 1079 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); 1080 if (flags & (GRE_VERSION|GRE_ROUTING)) 1081 return -EINVAL; 1082 1083 if (data[IFLA_GRE_COLLECT_METADATA] && 1084 data[IFLA_GRE_ENCAP_TYPE] && 1085 nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]) != TUNNEL_ENCAP_NONE) 1086 return -EINVAL; 1087 1088 return 0; 1089 } 1090 1091 static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[], 1092 struct netlink_ext_ack *extack) 1093 { 1094 __be32 daddr; 1095 1096 if (tb[IFLA_ADDRESS]) { 1097 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) 1098 return -EINVAL; 1099 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) 1100 return -EADDRNOTAVAIL; 1101 } 1102 1103 if (!data) 1104 goto out; 1105 1106 if (data[IFLA_GRE_REMOTE]) { 1107 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4); 1108 if (!daddr) 1109 return -EINVAL; 1110 } 1111 1112 out: 1113 return ipgre_tunnel_validate(tb, data, extack); 1114 } 1115 1116 static int erspan_validate(struct nlattr *tb[], struct nlattr *data[], 1117 struct netlink_ext_ack *extack) 1118 { 1119 __be16 flags = 0; 1120 int ret; 1121 1122 if (!data) 1123 return 0; 1124 1125 ret = ipgre_tap_validate(tb, data, extack); 1126 if (ret) 1127 return ret; 1128 1129 /* ERSPAN should only have GRE sequence and key flag */ 1130 if (data[IFLA_GRE_OFLAGS]) 1131 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); 1132 if (data[IFLA_GRE_IFLAGS]) 1133 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); 1134 if (!data[IFLA_GRE_COLLECT_METADATA] && 1135 flags != (GRE_SEQ | GRE_KEY)) 1136 return -EINVAL; 1137 1138 /* ERSPAN Session ID only has 10-bit. Since we reuse 1139 * 32-bit key field as ID, check it's range. 1140 */ 1141 if (data[IFLA_GRE_IKEY] && 1142 (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK)) 1143 return -EINVAL; 1144 1145 if (data[IFLA_GRE_OKEY] && 1146 (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK)) 1147 return -EINVAL; 1148 1149 return 0; 1150 } 1151 1152 static int ipgre_netlink_parms(struct net_device *dev, 1153 struct nlattr *data[], 1154 struct nlattr *tb[], 1155 struct ip_tunnel_parm *parms, 1156 __u32 *fwmark) 1157 { 1158 struct ip_tunnel *t = netdev_priv(dev); 1159 1160 memset(parms, 0, sizeof(*parms)); 1161 1162 parms->iph.protocol = IPPROTO_GRE; 1163 1164 if (!data) 1165 return 0; 1166 1167 if (data[IFLA_GRE_LINK]) 1168 parms->link = nla_get_u32(data[IFLA_GRE_LINK]); 1169 1170 if (data[IFLA_GRE_IFLAGS]) 1171 parms->i_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_IFLAGS])); 1172 1173 if (data[IFLA_GRE_OFLAGS]) 1174 parms->o_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_OFLAGS])); 1175 1176 if (data[IFLA_GRE_IKEY]) 1177 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]); 1178 1179 if (data[IFLA_GRE_OKEY]) 1180 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]); 1181 1182 if (data[IFLA_GRE_LOCAL]) 1183 parms->iph.saddr = nla_get_in_addr(data[IFLA_GRE_LOCAL]); 1184 1185 if (data[IFLA_GRE_REMOTE]) 1186 parms->iph.daddr = nla_get_in_addr(data[IFLA_GRE_REMOTE]); 1187 1188 if (data[IFLA_GRE_TTL]) 1189 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]); 1190 1191 if (data[IFLA_GRE_TOS]) 1192 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]); 1193 1194 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC])) { 1195 if (t->ignore_df) 1196 return -EINVAL; 1197 parms->iph.frag_off = htons(IP_DF); 1198 } 1199 1200 if (data[IFLA_GRE_COLLECT_METADATA]) { 1201 t->collect_md = true; 1202 if (dev->type == ARPHRD_IPGRE) 1203 dev->type = ARPHRD_NONE; 1204 } 1205 1206 if (data[IFLA_GRE_IGNORE_DF]) { 1207 if (nla_get_u8(data[IFLA_GRE_IGNORE_DF]) 1208 && (parms->iph.frag_off & htons(IP_DF))) 1209 return -EINVAL; 1210 t->ignore_df = !!nla_get_u8(data[IFLA_GRE_IGNORE_DF]); 1211 } 1212 1213 if (data[IFLA_GRE_FWMARK]) 1214 *fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]); 1215 1216 if (data[IFLA_GRE_ERSPAN_VER]) { 1217 t->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]); 1218 1219 if (t->erspan_ver != 1 && t->erspan_ver != 2) 1220 return -EINVAL; 1221 } 1222 1223 if (t->erspan_ver == 1) { 1224 if (data[IFLA_GRE_ERSPAN_INDEX]) { 1225 t->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]); 1226 if (t->index & ~INDEX_MASK) 1227 return -EINVAL; 1228 } 1229 } else if (t->erspan_ver == 2) { 1230 if (data[IFLA_GRE_ERSPAN_DIR]) { 1231 t->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]); 1232 if (t->dir & ~(DIR_MASK >> DIR_OFFSET)) 1233 return -EINVAL; 1234 } 1235 if (data[IFLA_GRE_ERSPAN_HWID]) { 1236 t->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]); 1237 if (t->hwid & ~(HWID_MASK >> HWID_OFFSET)) 1238 return -EINVAL; 1239 } 1240 } 1241 1242 return 0; 1243 } 1244 1245 /* This function returns true when ENCAP attributes are present in the nl msg */ 1246 static bool ipgre_netlink_encap_parms(struct nlattr *data[], 1247 struct ip_tunnel_encap *ipencap) 1248 { 1249 bool ret = false; 1250 1251 memset(ipencap, 0, sizeof(*ipencap)); 1252 1253 if (!data) 1254 return ret; 1255 1256 if (data[IFLA_GRE_ENCAP_TYPE]) { 1257 ret = true; 1258 ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]); 1259 } 1260 1261 if (data[IFLA_GRE_ENCAP_FLAGS]) { 1262 ret = true; 1263 ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]); 1264 } 1265 1266 if (data[IFLA_GRE_ENCAP_SPORT]) { 1267 ret = true; 1268 ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]); 1269 } 1270 1271 if (data[IFLA_GRE_ENCAP_DPORT]) { 1272 ret = true; 1273 ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]); 1274 } 1275 1276 return ret; 1277 } 1278 1279 static int gre_tap_init(struct net_device *dev) 1280 { 1281 __gre_tunnel_init(dev); 1282 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1283 netif_keep_dst(dev); 1284 1285 return ip_tunnel_init(dev); 1286 } 1287 1288 static const struct net_device_ops gre_tap_netdev_ops = { 1289 .ndo_init = gre_tap_init, 1290 .ndo_uninit = ip_tunnel_uninit, 1291 .ndo_start_xmit = gre_tap_xmit, 1292 .ndo_set_mac_address = eth_mac_addr, 1293 .ndo_validate_addr = eth_validate_addr, 1294 .ndo_change_mtu = ip_tunnel_change_mtu, 1295 .ndo_get_stats64 = ip_tunnel_get_stats64, 1296 .ndo_get_iflink = ip_tunnel_get_iflink, 1297 .ndo_fill_metadata_dst = gre_fill_metadata_dst, 1298 }; 1299 1300 static int erspan_tunnel_init(struct net_device *dev) 1301 { 1302 struct ip_tunnel *tunnel = netdev_priv(dev); 1303 int t_hlen; 1304 1305 tunnel->tun_hlen = 8; 1306 tunnel->parms.iph.protocol = IPPROTO_GRE; 1307 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen + 1308 erspan_hdr_len(tunnel->erspan_ver); 1309 t_hlen = tunnel->hlen + sizeof(struct iphdr); 1310 1311 dev->features |= GRE_FEATURES; 1312 dev->hw_features |= GRE_FEATURES; 1313 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1314 netif_keep_dst(dev); 1315 1316 return ip_tunnel_init(dev); 1317 } 1318 1319 static const struct net_device_ops erspan_netdev_ops = { 1320 .ndo_init = erspan_tunnel_init, 1321 .ndo_uninit = ip_tunnel_uninit, 1322 .ndo_start_xmit = erspan_xmit, 1323 .ndo_set_mac_address = eth_mac_addr, 1324 .ndo_validate_addr = eth_validate_addr, 1325 .ndo_change_mtu = ip_tunnel_change_mtu, 1326 .ndo_get_stats64 = ip_tunnel_get_stats64, 1327 .ndo_get_iflink = ip_tunnel_get_iflink, 1328 .ndo_fill_metadata_dst = gre_fill_metadata_dst, 1329 }; 1330 1331 static void ipgre_tap_setup(struct net_device *dev) 1332 { 1333 ether_setup(dev); 1334 dev->max_mtu = 0; 1335 dev->netdev_ops = &gre_tap_netdev_ops; 1336 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 1337 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1338 ip_tunnel_setup(dev, gre_tap_net_id); 1339 } 1340 1341 bool is_gretap_dev(const struct net_device *dev) 1342 { 1343 return dev->netdev_ops == &gre_tap_netdev_ops; 1344 } 1345 EXPORT_SYMBOL_GPL(is_gretap_dev); 1346 1347 static int ipgre_newlink(struct net *src_net, struct net_device *dev, 1348 struct nlattr *tb[], struct nlattr *data[], 1349 struct netlink_ext_ack *extack) 1350 { 1351 struct ip_tunnel_parm p; 1352 struct ip_tunnel_encap ipencap; 1353 __u32 fwmark = 0; 1354 int err; 1355 1356 if (ipgre_netlink_encap_parms(data, &ipencap)) { 1357 struct ip_tunnel *t = netdev_priv(dev); 1358 err = ip_tunnel_encap_setup(t, &ipencap); 1359 1360 if (err < 0) 1361 return err; 1362 } 1363 1364 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark); 1365 if (err < 0) 1366 return err; 1367 return ip_tunnel_newlink(dev, tb, &p, fwmark); 1368 } 1369 1370 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[], 1371 struct nlattr *data[], 1372 struct netlink_ext_ack *extack) 1373 { 1374 struct ip_tunnel *t = netdev_priv(dev); 1375 struct ip_tunnel_encap ipencap; 1376 __u32 fwmark = t->fwmark; 1377 struct ip_tunnel_parm p; 1378 int err; 1379 1380 if (ipgre_netlink_encap_parms(data, &ipencap)) { 1381 err = ip_tunnel_encap_setup(t, &ipencap); 1382 1383 if (err < 0) 1384 return err; 1385 } 1386 1387 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark); 1388 if (err < 0) 1389 return err; 1390 1391 err = ip_tunnel_changelink(dev, tb, &p, fwmark); 1392 if (err < 0) 1393 return err; 1394 1395 t->parms.i_flags = p.i_flags; 1396 t->parms.o_flags = p.o_flags; 1397 1398 if (strcmp(dev->rtnl_link_ops->kind, "erspan")) 1399 ipgre_link_update(dev, !tb[IFLA_MTU]); 1400 1401 return 0; 1402 } 1403 1404 static size_t ipgre_get_size(const struct net_device *dev) 1405 { 1406 return 1407 /* IFLA_GRE_LINK */ 1408 nla_total_size(4) + 1409 /* IFLA_GRE_IFLAGS */ 1410 nla_total_size(2) + 1411 /* IFLA_GRE_OFLAGS */ 1412 nla_total_size(2) + 1413 /* IFLA_GRE_IKEY */ 1414 nla_total_size(4) + 1415 /* IFLA_GRE_OKEY */ 1416 nla_total_size(4) + 1417 /* IFLA_GRE_LOCAL */ 1418 nla_total_size(4) + 1419 /* IFLA_GRE_REMOTE */ 1420 nla_total_size(4) + 1421 /* IFLA_GRE_TTL */ 1422 nla_total_size(1) + 1423 /* IFLA_GRE_TOS */ 1424 nla_total_size(1) + 1425 /* IFLA_GRE_PMTUDISC */ 1426 nla_total_size(1) + 1427 /* IFLA_GRE_ENCAP_TYPE */ 1428 nla_total_size(2) + 1429 /* IFLA_GRE_ENCAP_FLAGS */ 1430 nla_total_size(2) + 1431 /* IFLA_GRE_ENCAP_SPORT */ 1432 nla_total_size(2) + 1433 /* IFLA_GRE_ENCAP_DPORT */ 1434 nla_total_size(2) + 1435 /* IFLA_GRE_COLLECT_METADATA */ 1436 nla_total_size(0) + 1437 /* IFLA_GRE_IGNORE_DF */ 1438 nla_total_size(1) + 1439 /* IFLA_GRE_FWMARK */ 1440 nla_total_size(4) + 1441 /* IFLA_GRE_ERSPAN_INDEX */ 1442 nla_total_size(4) + 1443 /* IFLA_GRE_ERSPAN_VER */ 1444 nla_total_size(1) + 1445 /* IFLA_GRE_ERSPAN_DIR */ 1446 nla_total_size(1) + 1447 /* IFLA_GRE_ERSPAN_HWID */ 1448 nla_total_size(2) + 1449 0; 1450 } 1451 1452 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev) 1453 { 1454 struct ip_tunnel *t = netdev_priv(dev); 1455 struct ip_tunnel_parm *p = &t->parms; 1456 1457 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) || 1458 nla_put_be16(skb, IFLA_GRE_IFLAGS, 1459 gre_tnl_flags_to_gre_flags(p->i_flags)) || 1460 nla_put_be16(skb, IFLA_GRE_OFLAGS, 1461 gre_tnl_flags_to_gre_flags(p->o_flags)) || 1462 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) || 1463 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) || 1464 nla_put_in_addr(skb, IFLA_GRE_LOCAL, p->iph.saddr) || 1465 nla_put_in_addr(skb, IFLA_GRE_REMOTE, p->iph.daddr) || 1466 nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) || 1467 nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) || 1468 nla_put_u8(skb, IFLA_GRE_PMTUDISC, 1469 !!(p->iph.frag_off & htons(IP_DF))) || 1470 nla_put_u32(skb, IFLA_GRE_FWMARK, t->fwmark)) 1471 goto nla_put_failure; 1472 1473 if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE, 1474 t->encap.type) || 1475 nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT, 1476 t->encap.sport) || 1477 nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT, 1478 t->encap.dport) || 1479 nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS, 1480 t->encap.flags)) 1481 goto nla_put_failure; 1482 1483 if (nla_put_u8(skb, IFLA_GRE_IGNORE_DF, t->ignore_df)) 1484 goto nla_put_failure; 1485 1486 if (t->collect_md) { 1487 if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA)) 1488 goto nla_put_failure; 1489 } 1490 1491 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, t->erspan_ver)) 1492 goto nla_put_failure; 1493 1494 if (t->erspan_ver == 1) { 1495 if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, t->index)) 1496 goto nla_put_failure; 1497 } else if (t->erspan_ver == 2) { 1498 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, t->dir)) 1499 goto nla_put_failure; 1500 if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, t->hwid)) 1501 goto nla_put_failure; 1502 } 1503 1504 return 0; 1505 1506 nla_put_failure: 1507 return -EMSGSIZE; 1508 } 1509 1510 static void erspan_setup(struct net_device *dev) 1511 { 1512 ether_setup(dev); 1513 dev->netdev_ops = &erspan_netdev_ops; 1514 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 1515 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1516 ip_tunnel_setup(dev, erspan_net_id); 1517 } 1518 1519 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = { 1520 [IFLA_GRE_LINK] = { .type = NLA_U32 }, 1521 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 }, 1522 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 }, 1523 [IFLA_GRE_IKEY] = { .type = NLA_U32 }, 1524 [IFLA_GRE_OKEY] = { .type = NLA_U32 }, 1525 [IFLA_GRE_LOCAL] = { .len = FIELD_SIZEOF(struct iphdr, saddr) }, 1526 [IFLA_GRE_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) }, 1527 [IFLA_GRE_TTL] = { .type = NLA_U8 }, 1528 [IFLA_GRE_TOS] = { .type = NLA_U8 }, 1529 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 }, 1530 [IFLA_GRE_ENCAP_TYPE] = { .type = NLA_U16 }, 1531 [IFLA_GRE_ENCAP_FLAGS] = { .type = NLA_U16 }, 1532 [IFLA_GRE_ENCAP_SPORT] = { .type = NLA_U16 }, 1533 [IFLA_GRE_ENCAP_DPORT] = { .type = NLA_U16 }, 1534 [IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG }, 1535 [IFLA_GRE_IGNORE_DF] = { .type = NLA_U8 }, 1536 [IFLA_GRE_FWMARK] = { .type = NLA_U32 }, 1537 [IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 }, 1538 [IFLA_GRE_ERSPAN_VER] = { .type = NLA_U8 }, 1539 [IFLA_GRE_ERSPAN_DIR] = { .type = NLA_U8 }, 1540 [IFLA_GRE_ERSPAN_HWID] = { .type = NLA_U16 }, 1541 }; 1542 1543 static struct rtnl_link_ops ipgre_link_ops __read_mostly = { 1544 .kind = "gre", 1545 .maxtype = IFLA_GRE_MAX, 1546 .policy = ipgre_policy, 1547 .priv_size = sizeof(struct ip_tunnel), 1548 .setup = ipgre_tunnel_setup, 1549 .validate = ipgre_tunnel_validate, 1550 .newlink = ipgre_newlink, 1551 .changelink = ipgre_changelink, 1552 .dellink = ip_tunnel_dellink, 1553 .get_size = ipgre_get_size, 1554 .fill_info = ipgre_fill_info, 1555 .get_link_net = ip_tunnel_get_link_net, 1556 }; 1557 1558 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = { 1559 .kind = "gretap", 1560 .maxtype = IFLA_GRE_MAX, 1561 .policy = ipgre_policy, 1562 .priv_size = sizeof(struct ip_tunnel), 1563 .setup = ipgre_tap_setup, 1564 .validate = ipgre_tap_validate, 1565 .newlink = ipgre_newlink, 1566 .changelink = ipgre_changelink, 1567 .dellink = ip_tunnel_dellink, 1568 .get_size = ipgre_get_size, 1569 .fill_info = ipgre_fill_info, 1570 .get_link_net = ip_tunnel_get_link_net, 1571 }; 1572 1573 static struct rtnl_link_ops erspan_link_ops __read_mostly = { 1574 .kind = "erspan", 1575 .maxtype = IFLA_GRE_MAX, 1576 .policy = ipgre_policy, 1577 .priv_size = sizeof(struct ip_tunnel), 1578 .setup = erspan_setup, 1579 .validate = erspan_validate, 1580 .newlink = ipgre_newlink, 1581 .changelink = ipgre_changelink, 1582 .dellink = ip_tunnel_dellink, 1583 .get_size = ipgre_get_size, 1584 .fill_info = ipgre_fill_info, 1585 .get_link_net = ip_tunnel_get_link_net, 1586 }; 1587 1588 struct net_device *gretap_fb_dev_create(struct net *net, const char *name, 1589 u8 name_assign_type) 1590 { 1591 struct nlattr *tb[IFLA_MAX + 1]; 1592 struct net_device *dev; 1593 LIST_HEAD(list_kill); 1594 struct ip_tunnel *t; 1595 int err; 1596 1597 memset(&tb, 0, sizeof(tb)); 1598 1599 dev = rtnl_create_link(net, name, name_assign_type, 1600 &ipgre_tap_ops, tb); 1601 if (IS_ERR(dev)) 1602 return dev; 1603 1604 /* Configure flow based GRE device. */ 1605 t = netdev_priv(dev); 1606 t->collect_md = true; 1607 1608 err = ipgre_newlink(net, dev, tb, NULL, NULL); 1609 if (err < 0) { 1610 free_netdev(dev); 1611 return ERR_PTR(err); 1612 } 1613 1614 /* openvswitch users expect packet sizes to be unrestricted, 1615 * so set the largest MTU we can. 1616 */ 1617 err = __ip_tunnel_change_mtu(dev, IP_MAX_MTU, false); 1618 if (err) 1619 goto out; 1620 1621 err = rtnl_configure_link(dev, NULL); 1622 if (err < 0) 1623 goto out; 1624 1625 return dev; 1626 out: 1627 ip_tunnel_dellink(dev, &list_kill); 1628 unregister_netdevice_many(&list_kill); 1629 return ERR_PTR(err); 1630 } 1631 EXPORT_SYMBOL_GPL(gretap_fb_dev_create); 1632 1633 static int __net_init ipgre_tap_init_net(struct net *net) 1634 { 1635 return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, "gretap0"); 1636 } 1637 1638 static void __net_exit ipgre_tap_exit_batch_net(struct list_head *list_net) 1639 { 1640 ip_tunnel_delete_nets(list_net, gre_tap_net_id, &ipgre_tap_ops); 1641 } 1642 1643 static struct pernet_operations ipgre_tap_net_ops = { 1644 .init = ipgre_tap_init_net, 1645 .exit_batch = ipgre_tap_exit_batch_net, 1646 .id = &gre_tap_net_id, 1647 .size = sizeof(struct ip_tunnel_net), 1648 }; 1649 1650 static int __net_init erspan_init_net(struct net *net) 1651 { 1652 return ip_tunnel_init_net(net, erspan_net_id, 1653 &erspan_link_ops, "erspan0"); 1654 } 1655 1656 static void __net_exit erspan_exit_batch_net(struct list_head *net_list) 1657 { 1658 ip_tunnel_delete_nets(net_list, erspan_net_id, &erspan_link_ops); 1659 } 1660 1661 static struct pernet_operations erspan_net_ops = { 1662 .init = erspan_init_net, 1663 .exit_batch = erspan_exit_batch_net, 1664 .id = &erspan_net_id, 1665 .size = sizeof(struct ip_tunnel_net), 1666 }; 1667 1668 static int __init ipgre_init(void) 1669 { 1670 int err; 1671 1672 pr_info("GRE over IPv4 tunneling driver\n"); 1673 1674 err = register_pernet_device(&ipgre_net_ops); 1675 if (err < 0) 1676 return err; 1677 1678 err = register_pernet_device(&ipgre_tap_net_ops); 1679 if (err < 0) 1680 goto pnet_tap_failed; 1681 1682 err = register_pernet_device(&erspan_net_ops); 1683 if (err < 0) 1684 goto pnet_erspan_failed; 1685 1686 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO); 1687 if (err < 0) { 1688 pr_info("%s: can't add protocol\n", __func__); 1689 goto add_proto_failed; 1690 } 1691 1692 err = rtnl_link_register(&ipgre_link_ops); 1693 if (err < 0) 1694 goto rtnl_link_failed; 1695 1696 err = rtnl_link_register(&ipgre_tap_ops); 1697 if (err < 0) 1698 goto tap_ops_failed; 1699 1700 err = rtnl_link_register(&erspan_link_ops); 1701 if (err < 0) 1702 goto erspan_link_failed; 1703 1704 return 0; 1705 1706 erspan_link_failed: 1707 rtnl_link_unregister(&ipgre_tap_ops); 1708 tap_ops_failed: 1709 rtnl_link_unregister(&ipgre_link_ops); 1710 rtnl_link_failed: 1711 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); 1712 add_proto_failed: 1713 unregister_pernet_device(&erspan_net_ops); 1714 pnet_erspan_failed: 1715 unregister_pernet_device(&ipgre_tap_net_ops); 1716 pnet_tap_failed: 1717 unregister_pernet_device(&ipgre_net_ops); 1718 return err; 1719 } 1720 1721 static void __exit ipgre_fini(void) 1722 { 1723 rtnl_link_unregister(&ipgre_tap_ops); 1724 rtnl_link_unregister(&ipgre_link_ops); 1725 rtnl_link_unregister(&erspan_link_ops); 1726 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); 1727 unregister_pernet_device(&ipgre_tap_net_ops); 1728 unregister_pernet_device(&ipgre_net_ops); 1729 unregister_pernet_device(&erspan_net_ops); 1730 } 1731 1732 module_init(ipgre_init); 1733 module_exit(ipgre_fini); 1734 MODULE_LICENSE("GPL"); 1735 MODULE_ALIAS_RTNL_LINK("gre"); 1736 MODULE_ALIAS_RTNL_LINK("gretap"); 1737 MODULE_ALIAS_RTNL_LINK("erspan"); 1738 MODULE_ALIAS_NETDEV("gre0"); 1739 MODULE_ALIAS_NETDEV("gretap0"); 1740 MODULE_ALIAS_NETDEV("erspan0"); 1741