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; 581 582 tun_info = skb_tunnel_info(skb); 583 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) || 584 ip_tunnel_info_af(tun_info) != AF_INET)) 585 goto err_free_skb; 586 587 key = &tun_info->key; 588 md = ip_tunnel_info_opts(tun_info); 589 if (!md) 590 goto err_free_rt; 591 592 /* ERSPAN has fixed 8 byte GRE header */ 593 version = md->version; 594 tunnel_hlen = 8 + erspan_hdr_len(version); 595 596 rt = prepare_fb_xmit(skb, dev, &fl, tunnel_hlen); 597 if (!rt) 598 return; 599 600 if (gre_handle_offloads(skb, false)) 601 goto err_free_rt; 602 603 if (skb->len > dev->mtu + dev->hard_header_len) { 604 pskb_trim(skb, dev->mtu + dev->hard_header_len); 605 truncate = true; 606 } 607 608 if (version == 1) { 609 erspan_build_header(skb, ntohl(tunnel_id_to_key32(key->tun_id)), 610 ntohl(md->u.index), truncate, true); 611 } else if (version == 2) { 612 erspan_build_header_v2(skb, 613 ntohl(tunnel_id_to_key32(key->tun_id)), 614 md->u.md2.dir, 615 get_hwid(&md->u.md2), 616 truncate, true); 617 } else { 618 goto err_free_rt; 619 } 620 621 gre_build_header(skb, 8, TUNNEL_SEQ, 622 htons(ETH_P_ERSPAN), 0, htonl(tunnel->o_seqno++)); 623 624 df = key->tun_flags & TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0; 625 626 iptunnel_xmit(skb->sk, rt, skb, fl.saddr, key->u.ipv4.dst, IPPROTO_GRE, 627 key->tos, key->ttl, df, false); 628 return; 629 630 err_free_rt: 631 ip_rt_put(rt); 632 err_free_skb: 633 kfree_skb(skb); 634 dev->stats.tx_dropped++; 635 } 636 637 static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb) 638 { 639 struct ip_tunnel_info *info = skb_tunnel_info(skb); 640 struct rtable *rt; 641 struct flowi4 fl4; 642 643 if (ip_tunnel_info_af(info) != AF_INET) 644 return -EINVAL; 645 646 rt = gre_get_rt(skb, dev, &fl4, &info->key); 647 if (IS_ERR(rt)) 648 return PTR_ERR(rt); 649 650 ip_rt_put(rt); 651 info->key.u.ipv4.src = fl4.saddr; 652 return 0; 653 } 654 655 static netdev_tx_t ipgre_xmit(struct sk_buff *skb, 656 struct net_device *dev) 657 { 658 struct ip_tunnel *tunnel = netdev_priv(dev); 659 const struct iphdr *tnl_params; 660 661 if (tunnel->collect_md) { 662 gre_fb_xmit(skb, dev, skb->protocol); 663 return NETDEV_TX_OK; 664 } 665 666 if (dev->header_ops) { 667 /* Need space for new headers */ 668 if (skb_cow_head(skb, dev->needed_headroom - 669 (tunnel->hlen + sizeof(struct iphdr)))) 670 goto free_skb; 671 672 tnl_params = (const struct iphdr *)skb->data; 673 674 /* Pull skb since ip_tunnel_xmit() needs skb->data pointing 675 * to gre header. 676 */ 677 skb_pull(skb, tunnel->hlen + sizeof(struct iphdr)); 678 skb_reset_mac_header(skb); 679 } else { 680 if (skb_cow_head(skb, dev->needed_headroom)) 681 goto free_skb; 682 683 tnl_params = &tunnel->parms.iph; 684 } 685 686 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM))) 687 goto free_skb; 688 689 __gre_xmit(skb, dev, tnl_params, skb->protocol); 690 return NETDEV_TX_OK; 691 692 free_skb: 693 kfree_skb(skb); 694 dev->stats.tx_dropped++; 695 return NETDEV_TX_OK; 696 } 697 698 static netdev_tx_t erspan_xmit(struct sk_buff *skb, 699 struct net_device *dev) 700 { 701 struct ip_tunnel *tunnel = netdev_priv(dev); 702 bool truncate = false; 703 704 if (tunnel->collect_md) { 705 erspan_fb_xmit(skb, dev, skb->protocol); 706 return NETDEV_TX_OK; 707 } 708 709 if (gre_handle_offloads(skb, false)) 710 goto free_skb; 711 712 if (skb_cow_head(skb, dev->needed_headroom)) 713 goto free_skb; 714 715 if (skb->len > dev->mtu + dev->hard_header_len) { 716 pskb_trim(skb, dev->mtu + dev->hard_header_len); 717 truncate = true; 718 } 719 720 /* Push ERSPAN header */ 721 if (tunnel->erspan_ver == 1) 722 erspan_build_header(skb, ntohl(tunnel->parms.o_key), 723 tunnel->index, 724 truncate, true); 725 else 726 erspan_build_header_v2(skb, ntohl(tunnel->parms.o_key), 727 tunnel->dir, tunnel->hwid, 728 truncate, true); 729 730 tunnel->parms.o_flags &= ~TUNNEL_KEY; 731 __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_ERSPAN)); 732 return NETDEV_TX_OK; 733 734 free_skb: 735 kfree_skb(skb); 736 dev->stats.tx_dropped++; 737 return NETDEV_TX_OK; 738 } 739 740 static netdev_tx_t gre_tap_xmit(struct sk_buff *skb, 741 struct net_device *dev) 742 { 743 struct ip_tunnel *tunnel = netdev_priv(dev); 744 745 if (tunnel->collect_md) { 746 gre_fb_xmit(skb, dev, htons(ETH_P_TEB)); 747 return NETDEV_TX_OK; 748 } 749 750 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM))) 751 goto free_skb; 752 753 if (skb_cow_head(skb, dev->needed_headroom)) 754 goto free_skb; 755 756 __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB)); 757 return NETDEV_TX_OK; 758 759 free_skb: 760 kfree_skb(skb); 761 dev->stats.tx_dropped++; 762 return NETDEV_TX_OK; 763 } 764 765 static void ipgre_link_update(struct net_device *dev, bool set_mtu) 766 { 767 struct ip_tunnel *tunnel = netdev_priv(dev); 768 int len; 769 770 len = tunnel->tun_hlen; 771 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags); 772 len = tunnel->tun_hlen - len; 773 tunnel->hlen = tunnel->hlen + len; 774 775 dev->needed_headroom = dev->needed_headroom + len; 776 if (set_mtu) 777 dev->mtu = max_t(int, dev->mtu - len, 68); 778 779 if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) { 780 if (!(tunnel->parms.o_flags & TUNNEL_CSUM) || 781 tunnel->encap.type == TUNNEL_ENCAP_NONE) { 782 dev->features |= NETIF_F_GSO_SOFTWARE; 783 dev->hw_features |= NETIF_F_GSO_SOFTWARE; 784 } 785 dev->features |= NETIF_F_LLTX; 786 } 787 } 788 789 static int ipgre_tunnel_ioctl(struct net_device *dev, 790 struct ifreq *ifr, int cmd) 791 { 792 struct ip_tunnel_parm p; 793 int err; 794 795 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 796 return -EFAULT; 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_ioctl(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); 824 825 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 826 return -EFAULT; 827 828 return 0; 829 } 830 831 /* Nice toy. Unfortunately, useless in real life :-) 832 It allows to construct virtual multiprotocol broadcast "LAN" 833 over the Internet, provided multicast routing is tuned. 834 835 836 I have no idea was this bicycle invented before me, 837 so that I had to set ARPHRD_IPGRE to a random value. 838 I have an impression, that Cisco could make something similar, 839 but this feature is apparently missing in IOS<=11.2(8). 840 841 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks 842 with broadcast 224.66.66.66. If you have access to mbone, play with me :-) 843 844 ping -t 255 224.66.66.66 845 846 If nobody answers, mbone does not work. 847 848 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255 849 ip addr add 10.66.66.<somewhat>/24 dev Universe 850 ifconfig Universe up 851 ifconfig Universe add fe80::<Your_real_addr>/10 852 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96 853 ftp 10.66.66.66 854 ... 855 ftp fec0:6666:6666::193.233.7.65 856 ... 857 */ 858 static int ipgre_header(struct sk_buff *skb, struct net_device *dev, 859 unsigned short type, 860 const void *daddr, const void *saddr, unsigned int len) 861 { 862 struct ip_tunnel *t = netdev_priv(dev); 863 struct iphdr *iph; 864 struct gre_base_hdr *greh; 865 866 iph = skb_push(skb, t->hlen + sizeof(*iph)); 867 greh = (struct gre_base_hdr *)(iph+1); 868 greh->flags = gre_tnl_flags_to_gre_flags(t->parms.o_flags); 869 greh->protocol = htons(type); 870 871 memcpy(iph, &t->parms.iph, sizeof(struct iphdr)); 872 873 /* Set the source hardware address. */ 874 if (saddr) 875 memcpy(&iph->saddr, saddr, 4); 876 if (daddr) 877 memcpy(&iph->daddr, daddr, 4); 878 if (iph->daddr) 879 return t->hlen + sizeof(*iph); 880 881 return -(t->hlen + sizeof(*iph)); 882 } 883 884 static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr) 885 { 886 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb); 887 memcpy(haddr, &iph->saddr, 4); 888 return 4; 889 } 890 891 static const struct header_ops ipgre_header_ops = { 892 .create = ipgre_header, 893 .parse = ipgre_header_parse, 894 }; 895 896 #ifdef CONFIG_NET_IPGRE_BROADCAST 897 static int ipgre_open(struct net_device *dev) 898 { 899 struct ip_tunnel *t = netdev_priv(dev); 900 901 if (ipv4_is_multicast(t->parms.iph.daddr)) { 902 struct flowi4 fl4; 903 struct rtable *rt; 904 905 rt = ip_route_output_gre(t->net, &fl4, 906 t->parms.iph.daddr, 907 t->parms.iph.saddr, 908 t->parms.o_key, 909 RT_TOS(t->parms.iph.tos), 910 t->parms.link); 911 if (IS_ERR(rt)) 912 return -EADDRNOTAVAIL; 913 dev = rt->dst.dev; 914 ip_rt_put(rt); 915 if (!__in_dev_get_rtnl(dev)) 916 return -EADDRNOTAVAIL; 917 t->mlink = dev->ifindex; 918 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr); 919 } 920 return 0; 921 } 922 923 static int ipgre_close(struct net_device *dev) 924 { 925 struct ip_tunnel *t = netdev_priv(dev); 926 927 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) { 928 struct in_device *in_dev; 929 in_dev = inetdev_by_index(t->net, t->mlink); 930 if (in_dev) 931 ip_mc_dec_group(in_dev, t->parms.iph.daddr); 932 } 933 return 0; 934 } 935 #endif 936 937 static const struct net_device_ops ipgre_netdev_ops = { 938 .ndo_init = ipgre_tunnel_init, 939 .ndo_uninit = ip_tunnel_uninit, 940 #ifdef CONFIG_NET_IPGRE_BROADCAST 941 .ndo_open = ipgre_open, 942 .ndo_stop = ipgre_close, 943 #endif 944 .ndo_start_xmit = ipgre_xmit, 945 .ndo_do_ioctl = ipgre_tunnel_ioctl, 946 .ndo_change_mtu = ip_tunnel_change_mtu, 947 .ndo_get_stats64 = ip_tunnel_get_stats64, 948 .ndo_get_iflink = ip_tunnel_get_iflink, 949 }; 950 951 #define GRE_FEATURES (NETIF_F_SG | \ 952 NETIF_F_FRAGLIST | \ 953 NETIF_F_HIGHDMA | \ 954 NETIF_F_HW_CSUM) 955 956 static void ipgre_tunnel_setup(struct net_device *dev) 957 { 958 dev->netdev_ops = &ipgre_netdev_ops; 959 dev->type = ARPHRD_IPGRE; 960 ip_tunnel_setup(dev, ipgre_net_id); 961 } 962 963 static void __gre_tunnel_init(struct net_device *dev) 964 { 965 struct ip_tunnel *tunnel; 966 int t_hlen; 967 968 tunnel = netdev_priv(dev); 969 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags); 970 tunnel->parms.iph.protocol = IPPROTO_GRE; 971 972 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen; 973 974 t_hlen = tunnel->hlen + sizeof(struct iphdr); 975 976 dev->features |= GRE_FEATURES; 977 dev->hw_features |= GRE_FEATURES; 978 979 if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) { 980 /* TCP offload with GRE SEQ is not supported, nor 981 * can we support 2 levels of outer headers requiring 982 * an update. 983 */ 984 if (!(tunnel->parms.o_flags & TUNNEL_CSUM) || 985 (tunnel->encap.type == TUNNEL_ENCAP_NONE)) { 986 dev->features |= NETIF_F_GSO_SOFTWARE; 987 dev->hw_features |= NETIF_F_GSO_SOFTWARE; 988 } 989 990 /* Can use a lockless transmit, unless we generate 991 * output sequences 992 */ 993 dev->features |= NETIF_F_LLTX; 994 } 995 } 996 997 static int ipgre_tunnel_init(struct net_device *dev) 998 { 999 struct ip_tunnel *tunnel = netdev_priv(dev); 1000 struct iphdr *iph = &tunnel->parms.iph; 1001 1002 __gre_tunnel_init(dev); 1003 1004 memcpy(dev->dev_addr, &iph->saddr, 4); 1005 memcpy(dev->broadcast, &iph->daddr, 4); 1006 1007 dev->flags = IFF_NOARP; 1008 netif_keep_dst(dev); 1009 dev->addr_len = 4; 1010 1011 if (iph->daddr && !tunnel->collect_md) { 1012 #ifdef CONFIG_NET_IPGRE_BROADCAST 1013 if (ipv4_is_multicast(iph->daddr)) { 1014 if (!iph->saddr) 1015 return -EINVAL; 1016 dev->flags = IFF_BROADCAST; 1017 dev->header_ops = &ipgre_header_ops; 1018 } 1019 #endif 1020 } else if (!tunnel->collect_md) { 1021 dev->header_ops = &ipgre_header_ops; 1022 } 1023 1024 return ip_tunnel_init(dev); 1025 } 1026 1027 static const struct gre_protocol ipgre_protocol = { 1028 .handler = gre_rcv, 1029 .err_handler = gre_err, 1030 }; 1031 1032 static int __net_init ipgre_init_net(struct net *net) 1033 { 1034 return ip_tunnel_init_net(net, ipgre_net_id, &ipgre_link_ops, NULL); 1035 } 1036 1037 static void __net_exit ipgre_exit_batch_net(struct list_head *list_net) 1038 { 1039 ip_tunnel_delete_nets(list_net, ipgre_net_id, &ipgre_link_ops); 1040 } 1041 1042 static struct pernet_operations ipgre_net_ops = { 1043 .init = ipgre_init_net, 1044 .exit_batch = ipgre_exit_batch_net, 1045 .id = &ipgre_net_id, 1046 .size = sizeof(struct ip_tunnel_net), 1047 }; 1048 1049 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[], 1050 struct netlink_ext_ack *extack) 1051 { 1052 __be16 flags; 1053 1054 if (!data) 1055 return 0; 1056 1057 flags = 0; 1058 if (data[IFLA_GRE_IFLAGS]) 1059 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); 1060 if (data[IFLA_GRE_OFLAGS]) 1061 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); 1062 if (flags & (GRE_VERSION|GRE_ROUTING)) 1063 return -EINVAL; 1064 1065 if (data[IFLA_GRE_COLLECT_METADATA] && 1066 data[IFLA_GRE_ENCAP_TYPE] && 1067 nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]) != TUNNEL_ENCAP_NONE) 1068 return -EINVAL; 1069 1070 return 0; 1071 } 1072 1073 static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[], 1074 struct netlink_ext_ack *extack) 1075 { 1076 __be32 daddr; 1077 1078 if (tb[IFLA_ADDRESS]) { 1079 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) 1080 return -EINVAL; 1081 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) 1082 return -EADDRNOTAVAIL; 1083 } 1084 1085 if (!data) 1086 goto out; 1087 1088 if (data[IFLA_GRE_REMOTE]) { 1089 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4); 1090 if (!daddr) 1091 return -EINVAL; 1092 } 1093 1094 out: 1095 return ipgre_tunnel_validate(tb, data, extack); 1096 } 1097 1098 static int erspan_validate(struct nlattr *tb[], struct nlattr *data[], 1099 struct netlink_ext_ack *extack) 1100 { 1101 __be16 flags = 0; 1102 int ret; 1103 1104 if (!data) 1105 return 0; 1106 1107 ret = ipgre_tap_validate(tb, data, extack); 1108 if (ret) 1109 return ret; 1110 1111 /* ERSPAN should only have GRE sequence and key flag */ 1112 if (data[IFLA_GRE_OFLAGS]) 1113 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); 1114 if (data[IFLA_GRE_IFLAGS]) 1115 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); 1116 if (!data[IFLA_GRE_COLLECT_METADATA] && 1117 flags != (GRE_SEQ | GRE_KEY)) 1118 return -EINVAL; 1119 1120 /* ERSPAN Session ID only has 10-bit. Since we reuse 1121 * 32-bit key field as ID, check it's range. 1122 */ 1123 if (data[IFLA_GRE_IKEY] && 1124 (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK)) 1125 return -EINVAL; 1126 1127 if (data[IFLA_GRE_OKEY] && 1128 (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK)) 1129 return -EINVAL; 1130 1131 return 0; 1132 } 1133 1134 static int ipgre_netlink_parms(struct net_device *dev, 1135 struct nlattr *data[], 1136 struct nlattr *tb[], 1137 struct ip_tunnel_parm *parms, 1138 __u32 *fwmark) 1139 { 1140 struct ip_tunnel *t = netdev_priv(dev); 1141 1142 memset(parms, 0, sizeof(*parms)); 1143 1144 parms->iph.protocol = IPPROTO_GRE; 1145 1146 if (!data) 1147 return 0; 1148 1149 if (data[IFLA_GRE_LINK]) 1150 parms->link = nla_get_u32(data[IFLA_GRE_LINK]); 1151 1152 if (data[IFLA_GRE_IFLAGS]) 1153 parms->i_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_IFLAGS])); 1154 1155 if (data[IFLA_GRE_OFLAGS]) 1156 parms->o_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_OFLAGS])); 1157 1158 if (data[IFLA_GRE_IKEY]) 1159 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]); 1160 1161 if (data[IFLA_GRE_OKEY]) 1162 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]); 1163 1164 if (data[IFLA_GRE_LOCAL]) 1165 parms->iph.saddr = nla_get_in_addr(data[IFLA_GRE_LOCAL]); 1166 1167 if (data[IFLA_GRE_REMOTE]) 1168 parms->iph.daddr = nla_get_in_addr(data[IFLA_GRE_REMOTE]); 1169 1170 if (data[IFLA_GRE_TTL]) 1171 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]); 1172 1173 if (data[IFLA_GRE_TOS]) 1174 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]); 1175 1176 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC])) { 1177 if (t->ignore_df) 1178 return -EINVAL; 1179 parms->iph.frag_off = htons(IP_DF); 1180 } 1181 1182 if (data[IFLA_GRE_COLLECT_METADATA]) { 1183 t->collect_md = true; 1184 if (dev->type == ARPHRD_IPGRE) 1185 dev->type = ARPHRD_NONE; 1186 } 1187 1188 if (data[IFLA_GRE_IGNORE_DF]) { 1189 if (nla_get_u8(data[IFLA_GRE_IGNORE_DF]) 1190 && (parms->iph.frag_off & htons(IP_DF))) 1191 return -EINVAL; 1192 t->ignore_df = !!nla_get_u8(data[IFLA_GRE_IGNORE_DF]); 1193 } 1194 1195 if (data[IFLA_GRE_FWMARK]) 1196 *fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]); 1197 1198 if (data[IFLA_GRE_ERSPAN_VER]) { 1199 t->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]); 1200 1201 if (t->erspan_ver != 1 && t->erspan_ver != 2) 1202 return -EINVAL; 1203 } 1204 1205 if (t->erspan_ver == 1) { 1206 if (data[IFLA_GRE_ERSPAN_INDEX]) { 1207 t->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]); 1208 if (t->index & ~INDEX_MASK) 1209 return -EINVAL; 1210 } 1211 } else if (t->erspan_ver == 2) { 1212 if (data[IFLA_GRE_ERSPAN_DIR]) { 1213 t->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]); 1214 if (t->dir & ~(DIR_MASK >> DIR_OFFSET)) 1215 return -EINVAL; 1216 } 1217 if (data[IFLA_GRE_ERSPAN_HWID]) { 1218 t->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]); 1219 if (t->hwid & ~(HWID_MASK >> HWID_OFFSET)) 1220 return -EINVAL; 1221 } 1222 } 1223 1224 return 0; 1225 } 1226 1227 /* This function returns true when ENCAP attributes are present in the nl msg */ 1228 static bool ipgre_netlink_encap_parms(struct nlattr *data[], 1229 struct ip_tunnel_encap *ipencap) 1230 { 1231 bool ret = false; 1232 1233 memset(ipencap, 0, sizeof(*ipencap)); 1234 1235 if (!data) 1236 return ret; 1237 1238 if (data[IFLA_GRE_ENCAP_TYPE]) { 1239 ret = true; 1240 ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]); 1241 } 1242 1243 if (data[IFLA_GRE_ENCAP_FLAGS]) { 1244 ret = true; 1245 ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]); 1246 } 1247 1248 if (data[IFLA_GRE_ENCAP_SPORT]) { 1249 ret = true; 1250 ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]); 1251 } 1252 1253 if (data[IFLA_GRE_ENCAP_DPORT]) { 1254 ret = true; 1255 ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]); 1256 } 1257 1258 return ret; 1259 } 1260 1261 static int gre_tap_init(struct net_device *dev) 1262 { 1263 __gre_tunnel_init(dev); 1264 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1265 netif_keep_dst(dev); 1266 1267 return ip_tunnel_init(dev); 1268 } 1269 1270 static const struct net_device_ops gre_tap_netdev_ops = { 1271 .ndo_init = gre_tap_init, 1272 .ndo_uninit = ip_tunnel_uninit, 1273 .ndo_start_xmit = gre_tap_xmit, 1274 .ndo_set_mac_address = eth_mac_addr, 1275 .ndo_validate_addr = eth_validate_addr, 1276 .ndo_change_mtu = ip_tunnel_change_mtu, 1277 .ndo_get_stats64 = ip_tunnel_get_stats64, 1278 .ndo_get_iflink = ip_tunnel_get_iflink, 1279 .ndo_fill_metadata_dst = gre_fill_metadata_dst, 1280 }; 1281 1282 static int erspan_tunnel_init(struct net_device *dev) 1283 { 1284 struct ip_tunnel *tunnel = netdev_priv(dev); 1285 int t_hlen; 1286 1287 tunnel->tun_hlen = 8; 1288 tunnel->parms.iph.protocol = IPPROTO_GRE; 1289 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen + 1290 erspan_hdr_len(tunnel->erspan_ver); 1291 t_hlen = tunnel->hlen + sizeof(struct iphdr); 1292 1293 dev->features |= GRE_FEATURES; 1294 dev->hw_features |= GRE_FEATURES; 1295 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1296 netif_keep_dst(dev); 1297 1298 return ip_tunnel_init(dev); 1299 } 1300 1301 static const struct net_device_ops erspan_netdev_ops = { 1302 .ndo_init = erspan_tunnel_init, 1303 .ndo_uninit = ip_tunnel_uninit, 1304 .ndo_start_xmit = erspan_xmit, 1305 .ndo_set_mac_address = eth_mac_addr, 1306 .ndo_validate_addr = eth_validate_addr, 1307 .ndo_change_mtu = ip_tunnel_change_mtu, 1308 .ndo_get_stats64 = ip_tunnel_get_stats64, 1309 .ndo_get_iflink = ip_tunnel_get_iflink, 1310 .ndo_fill_metadata_dst = gre_fill_metadata_dst, 1311 }; 1312 1313 static void ipgre_tap_setup(struct net_device *dev) 1314 { 1315 ether_setup(dev); 1316 dev->max_mtu = 0; 1317 dev->netdev_ops = &gre_tap_netdev_ops; 1318 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 1319 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1320 ip_tunnel_setup(dev, gre_tap_net_id); 1321 } 1322 1323 bool is_gretap_dev(const struct net_device *dev) 1324 { 1325 return dev->netdev_ops == &gre_tap_netdev_ops; 1326 } 1327 EXPORT_SYMBOL_GPL(is_gretap_dev); 1328 1329 static int ipgre_newlink(struct net *src_net, struct net_device *dev, 1330 struct nlattr *tb[], struct nlattr *data[], 1331 struct netlink_ext_ack *extack) 1332 { 1333 struct ip_tunnel_parm p; 1334 struct ip_tunnel_encap ipencap; 1335 __u32 fwmark = 0; 1336 int err; 1337 1338 if (ipgre_netlink_encap_parms(data, &ipencap)) { 1339 struct ip_tunnel *t = netdev_priv(dev); 1340 err = ip_tunnel_encap_setup(t, &ipencap); 1341 1342 if (err < 0) 1343 return err; 1344 } 1345 1346 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark); 1347 if (err < 0) 1348 return err; 1349 return ip_tunnel_newlink(dev, tb, &p, fwmark); 1350 } 1351 1352 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[], 1353 struct nlattr *data[], 1354 struct netlink_ext_ack *extack) 1355 { 1356 struct ip_tunnel *t = netdev_priv(dev); 1357 struct ip_tunnel_encap ipencap; 1358 __u32 fwmark = t->fwmark; 1359 struct ip_tunnel_parm p; 1360 int err; 1361 1362 if (ipgre_netlink_encap_parms(data, &ipencap)) { 1363 err = ip_tunnel_encap_setup(t, &ipencap); 1364 1365 if (err < 0) 1366 return err; 1367 } 1368 1369 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark); 1370 if (err < 0) 1371 return err; 1372 1373 err = ip_tunnel_changelink(dev, tb, &p, fwmark); 1374 if (err < 0) 1375 return err; 1376 1377 t->parms.i_flags = p.i_flags; 1378 t->parms.o_flags = p.o_flags; 1379 1380 if (strcmp(dev->rtnl_link_ops->kind, "erspan")) 1381 ipgre_link_update(dev, !tb[IFLA_MTU]); 1382 1383 return 0; 1384 } 1385 1386 static size_t ipgre_get_size(const struct net_device *dev) 1387 { 1388 return 1389 /* IFLA_GRE_LINK */ 1390 nla_total_size(4) + 1391 /* IFLA_GRE_IFLAGS */ 1392 nla_total_size(2) + 1393 /* IFLA_GRE_OFLAGS */ 1394 nla_total_size(2) + 1395 /* IFLA_GRE_IKEY */ 1396 nla_total_size(4) + 1397 /* IFLA_GRE_OKEY */ 1398 nla_total_size(4) + 1399 /* IFLA_GRE_LOCAL */ 1400 nla_total_size(4) + 1401 /* IFLA_GRE_REMOTE */ 1402 nla_total_size(4) + 1403 /* IFLA_GRE_TTL */ 1404 nla_total_size(1) + 1405 /* IFLA_GRE_TOS */ 1406 nla_total_size(1) + 1407 /* IFLA_GRE_PMTUDISC */ 1408 nla_total_size(1) + 1409 /* IFLA_GRE_ENCAP_TYPE */ 1410 nla_total_size(2) + 1411 /* IFLA_GRE_ENCAP_FLAGS */ 1412 nla_total_size(2) + 1413 /* IFLA_GRE_ENCAP_SPORT */ 1414 nla_total_size(2) + 1415 /* IFLA_GRE_ENCAP_DPORT */ 1416 nla_total_size(2) + 1417 /* IFLA_GRE_COLLECT_METADATA */ 1418 nla_total_size(0) + 1419 /* IFLA_GRE_IGNORE_DF */ 1420 nla_total_size(1) + 1421 /* IFLA_GRE_FWMARK */ 1422 nla_total_size(4) + 1423 /* IFLA_GRE_ERSPAN_INDEX */ 1424 nla_total_size(4) + 1425 /* IFLA_GRE_ERSPAN_VER */ 1426 nla_total_size(1) + 1427 /* IFLA_GRE_ERSPAN_DIR */ 1428 nla_total_size(1) + 1429 /* IFLA_GRE_ERSPAN_HWID */ 1430 nla_total_size(2) + 1431 0; 1432 } 1433 1434 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev) 1435 { 1436 struct ip_tunnel *t = netdev_priv(dev); 1437 struct ip_tunnel_parm *p = &t->parms; 1438 1439 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) || 1440 nla_put_be16(skb, IFLA_GRE_IFLAGS, 1441 gre_tnl_flags_to_gre_flags(p->i_flags)) || 1442 nla_put_be16(skb, IFLA_GRE_OFLAGS, 1443 gre_tnl_flags_to_gre_flags(p->o_flags)) || 1444 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) || 1445 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) || 1446 nla_put_in_addr(skb, IFLA_GRE_LOCAL, p->iph.saddr) || 1447 nla_put_in_addr(skb, IFLA_GRE_REMOTE, p->iph.daddr) || 1448 nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) || 1449 nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) || 1450 nla_put_u8(skb, IFLA_GRE_PMTUDISC, 1451 !!(p->iph.frag_off & htons(IP_DF))) || 1452 nla_put_u32(skb, IFLA_GRE_FWMARK, t->fwmark)) 1453 goto nla_put_failure; 1454 1455 if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE, 1456 t->encap.type) || 1457 nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT, 1458 t->encap.sport) || 1459 nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT, 1460 t->encap.dport) || 1461 nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS, 1462 t->encap.flags)) 1463 goto nla_put_failure; 1464 1465 if (nla_put_u8(skb, IFLA_GRE_IGNORE_DF, t->ignore_df)) 1466 goto nla_put_failure; 1467 1468 if (t->collect_md) { 1469 if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA)) 1470 goto nla_put_failure; 1471 } 1472 1473 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, t->erspan_ver)) 1474 goto nla_put_failure; 1475 1476 if (t->erspan_ver == 1) { 1477 if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, t->index)) 1478 goto nla_put_failure; 1479 } else if (t->erspan_ver == 2) { 1480 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, t->dir)) 1481 goto nla_put_failure; 1482 if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, t->hwid)) 1483 goto nla_put_failure; 1484 } 1485 1486 return 0; 1487 1488 nla_put_failure: 1489 return -EMSGSIZE; 1490 } 1491 1492 static void erspan_setup(struct net_device *dev) 1493 { 1494 ether_setup(dev); 1495 dev->netdev_ops = &erspan_netdev_ops; 1496 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 1497 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1498 ip_tunnel_setup(dev, erspan_net_id); 1499 } 1500 1501 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = { 1502 [IFLA_GRE_LINK] = { .type = NLA_U32 }, 1503 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 }, 1504 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 }, 1505 [IFLA_GRE_IKEY] = { .type = NLA_U32 }, 1506 [IFLA_GRE_OKEY] = { .type = NLA_U32 }, 1507 [IFLA_GRE_LOCAL] = { .len = FIELD_SIZEOF(struct iphdr, saddr) }, 1508 [IFLA_GRE_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) }, 1509 [IFLA_GRE_TTL] = { .type = NLA_U8 }, 1510 [IFLA_GRE_TOS] = { .type = NLA_U8 }, 1511 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 }, 1512 [IFLA_GRE_ENCAP_TYPE] = { .type = NLA_U16 }, 1513 [IFLA_GRE_ENCAP_FLAGS] = { .type = NLA_U16 }, 1514 [IFLA_GRE_ENCAP_SPORT] = { .type = NLA_U16 }, 1515 [IFLA_GRE_ENCAP_DPORT] = { .type = NLA_U16 }, 1516 [IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG }, 1517 [IFLA_GRE_IGNORE_DF] = { .type = NLA_U8 }, 1518 [IFLA_GRE_FWMARK] = { .type = NLA_U32 }, 1519 [IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 }, 1520 [IFLA_GRE_ERSPAN_VER] = { .type = NLA_U8 }, 1521 [IFLA_GRE_ERSPAN_DIR] = { .type = NLA_U8 }, 1522 [IFLA_GRE_ERSPAN_HWID] = { .type = NLA_U16 }, 1523 }; 1524 1525 static struct rtnl_link_ops ipgre_link_ops __read_mostly = { 1526 .kind = "gre", 1527 .maxtype = IFLA_GRE_MAX, 1528 .policy = ipgre_policy, 1529 .priv_size = sizeof(struct ip_tunnel), 1530 .setup = ipgre_tunnel_setup, 1531 .validate = ipgre_tunnel_validate, 1532 .newlink = ipgre_newlink, 1533 .changelink = ipgre_changelink, 1534 .dellink = ip_tunnel_dellink, 1535 .get_size = ipgre_get_size, 1536 .fill_info = ipgre_fill_info, 1537 .get_link_net = ip_tunnel_get_link_net, 1538 }; 1539 1540 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = { 1541 .kind = "gretap", 1542 .maxtype = IFLA_GRE_MAX, 1543 .policy = ipgre_policy, 1544 .priv_size = sizeof(struct ip_tunnel), 1545 .setup = ipgre_tap_setup, 1546 .validate = ipgre_tap_validate, 1547 .newlink = ipgre_newlink, 1548 .changelink = ipgre_changelink, 1549 .dellink = ip_tunnel_dellink, 1550 .get_size = ipgre_get_size, 1551 .fill_info = ipgre_fill_info, 1552 .get_link_net = ip_tunnel_get_link_net, 1553 }; 1554 1555 static struct rtnl_link_ops erspan_link_ops __read_mostly = { 1556 .kind = "erspan", 1557 .maxtype = IFLA_GRE_MAX, 1558 .policy = ipgre_policy, 1559 .priv_size = sizeof(struct ip_tunnel), 1560 .setup = erspan_setup, 1561 .validate = erspan_validate, 1562 .newlink = ipgre_newlink, 1563 .changelink = ipgre_changelink, 1564 .dellink = ip_tunnel_dellink, 1565 .get_size = ipgre_get_size, 1566 .fill_info = ipgre_fill_info, 1567 .get_link_net = ip_tunnel_get_link_net, 1568 }; 1569 1570 struct net_device *gretap_fb_dev_create(struct net *net, const char *name, 1571 u8 name_assign_type) 1572 { 1573 struct nlattr *tb[IFLA_MAX + 1]; 1574 struct net_device *dev; 1575 LIST_HEAD(list_kill); 1576 struct ip_tunnel *t; 1577 int err; 1578 1579 memset(&tb, 0, sizeof(tb)); 1580 1581 dev = rtnl_create_link(net, name, name_assign_type, 1582 &ipgre_tap_ops, tb); 1583 if (IS_ERR(dev)) 1584 return dev; 1585 1586 /* Configure flow based GRE device. */ 1587 t = netdev_priv(dev); 1588 t->collect_md = true; 1589 1590 err = ipgre_newlink(net, dev, tb, NULL, NULL); 1591 if (err < 0) { 1592 free_netdev(dev); 1593 return ERR_PTR(err); 1594 } 1595 1596 /* openvswitch users expect packet sizes to be unrestricted, 1597 * so set the largest MTU we can. 1598 */ 1599 err = __ip_tunnel_change_mtu(dev, IP_MAX_MTU, false); 1600 if (err) 1601 goto out; 1602 1603 err = rtnl_configure_link(dev, NULL); 1604 if (err < 0) 1605 goto out; 1606 1607 return dev; 1608 out: 1609 ip_tunnel_dellink(dev, &list_kill); 1610 unregister_netdevice_many(&list_kill); 1611 return ERR_PTR(err); 1612 } 1613 EXPORT_SYMBOL_GPL(gretap_fb_dev_create); 1614 1615 static int __net_init ipgre_tap_init_net(struct net *net) 1616 { 1617 return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, "gretap0"); 1618 } 1619 1620 static void __net_exit ipgre_tap_exit_batch_net(struct list_head *list_net) 1621 { 1622 ip_tunnel_delete_nets(list_net, gre_tap_net_id, &ipgre_tap_ops); 1623 } 1624 1625 static struct pernet_operations ipgre_tap_net_ops = { 1626 .init = ipgre_tap_init_net, 1627 .exit_batch = ipgre_tap_exit_batch_net, 1628 .id = &gre_tap_net_id, 1629 .size = sizeof(struct ip_tunnel_net), 1630 }; 1631 1632 static int __net_init erspan_init_net(struct net *net) 1633 { 1634 return ip_tunnel_init_net(net, erspan_net_id, 1635 &erspan_link_ops, "erspan0"); 1636 } 1637 1638 static void __net_exit erspan_exit_batch_net(struct list_head *net_list) 1639 { 1640 ip_tunnel_delete_nets(net_list, erspan_net_id, &erspan_link_ops); 1641 } 1642 1643 static struct pernet_operations erspan_net_ops = { 1644 .init = erspan_init_net, 1645 .exit_batch = erspan_exit_batch_net, 1646 .id = &erspan_net_id, 1647 .size = sizeof(struct ip_tunnel_net), 1648 }; 1649 1650 static int __init ipgre_init(void) 1651 { 1652 int err; 1653 1654 pr_info("GRE over IPv4 tunneling driver\n"); 1655 1656 err = register_pernet_device(&ipgre_net_ops); 1657 if (err < 0) 1658 return err; 1659 1660 err = register_pernet_device(&ipgre_tap_net_ops); 1661 if (err < 0) 1662 goto pnet_tap_failed; 1663 1664 err = register_pernet_device(&erspan_net_ops); 1665 if (err < 0) 1666 goto pnet_erspan_failed; 1667 1668 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO); 1669 if (err < 0) { 1670 pr_info("%s: can't add protocol\n", __func__); 1671 goto add_proto_failed; 1672 } 1673 1674 err = rtnl_link_register(&ipgre_link_ops); 1675 if (err < 0) 1676 goto rtnl_link_failed; 1677 1678 err = rtnl_link_register(&ipgre_tap_ops); 1679 if (err < 0) 1680 goto tap_ops_failed; 1681 1682 err = rtnl_link_register(&erspan_link_ops); 1683 if (err < 0) 1684 goto erspan_link_failed; 1685 1686 return 0; 1687 1688 erspan_link_failed: 1689 rtnl_link_unregister(&ipgre_tap_ops); 1690 tap_ops_failed: 1691 rtnl_link_unregister(&ipgre_link_ops); 1692 rtnl_link_failed: 1693 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); 1694 add_proto_failed: 1695 unregister_pernet_device(&erspan_net_ops); 1696 pnet_erspan_failed: 1697 unregister_pernet_device(&ipgre_tap_net_ops); 1698 pnet_tap_failed: 1699 unregister_pernet_device(&ipgre_net_ops); 1700 return err; 1701 } 1702 1703 static void __exit ipgre_fini(void) 1704 { 1705 rtnl_link_unregister(&ipgre_tap_ops); 1706 rtnl_link_unregister(&ipgre_link_ops); 1707 rtnl_link_unregister(&erspan_link_ops); 1708 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); 1709 unregister_pernet_device(&ipgre_tap_net_ops); 1710 unregister_pernet_device(&ipgre_net_ops); 1711 unregister_pernet_device(&erspan_net_ops); 1712 } 1713 1714 module_init(ipgre_init); 1715 module_exit(ipgre_fini); 1716 MODULE_LICENSE("GPL"); 1717 MODULE_ALIAS_RTNL_LINK("gre"); 1718 MODULE_ALIAS_RTNL_LINK("gretap"); 1719 MODULE_ALIAS_RTNL_LINK("erspan"); 1720 MODULE_ALIAS_NETDEV("gre0"); 1721 MODULE_ALIAS_NETDEV("gretap0"); 1722 MODULE_ALIAS_NETDEV("erspan0"); 1723