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 __be32 id, u32 index, bool truncate); 118 119 static unsigned int ipgre_net_id __read_mostly; 120 static unsigned int gre_tap_net_id __read_mostly; 121 static unsigned int erspan_net_id __read_mostly; 122 123 static void ipgre_err(struct sk_buff *skb, u32 info, 124 const struct tnl_ptk_info *tpi) 125 { 126 127 /* All the routers (except for Linux) return only 128 8 bytes of packet payload. It means, that precise relaying of 129 ICMP in the real Internet is absolutely infeasible. 130 131 Moreover, Cisco "wise men" put GRE key to the third word 132 in GRE header. It makes impossible maintaining even soft 133 state for keyed GRE tunnels with enabled checksum. Tell 134 them "thank you". 135 136 Well, I wonder, rfc1812 was written by Cisco employee, 137 what the hell these idiots break standards established 138 by themselves??? 139 */ 140 struct net *net = dev_net(skb->dev); 141 struct ip_tunnel_net *itn; 142 const struct iphdr *iph; 143 const int type = icmp_hdr(skb)->type; 144 const int code = icmp_hdr(skb)->code; 145 unsigned int data_len = 0; 146 struct ip_tunnel *t; 147 148 switch (type) { 149 default: 150 case ICMP_PARAMETERPROB: 151 return; 152 153 case ICMP_DEST_UNREACH: 154 switch (code) { 155 case ICMP_SR_FAILED: 156 case ICMP_PORT_UNREACH: 157 /* Impossible event. */ 158 return; 159 default: 160 /* All others are translated to HOST_UNREACH. 161 rfc2003 contains "deep thoughts" about NET_UNREACH, 162 I believe they are just ether pollution. --ANK 163 */ 164 break; 165 } 166 break; 167 168 case ICMP_TIME_EXCEEDED: 169 if (code != ICMP_EXC_TTL) 170 return; 171 data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */ 172 break; 173 174 case ICMP_REDIRECT: 175 break; 176 } 177 178 if (tpi->proto == htons(ETH_P_TEB)) 179 itn = net_generic(net, gre_tap_net_id); 180 else 181 itn = net_generic(net, ipgre_net_id); 182 183 iph = (const struct iphdr *)(icmp_hdr(skb) + 1); 184 t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags, 185 iph->daddr, iph->saddr, tpi->key); 186 187 if (!t) 188 return; 189 190 #if IS_ENABLED(CONFIG_IPV6) 191 if (tpi->proto == htons(ETH_P_IPV6) && 192 !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4 + tpi->hdr_len, 193 type, data_len)) 194 return; 195 #endif 196 197 if (t->parms.iph.daddr == 0 || 198 ipv4_is_multicast(t->parms.iph.daddr)) 199 return; 200 201 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 202 return; 203 204 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) 205 t->err_count++; 206 else 207 t->err_count = 1; 208 t->err_time = jiffies; 209 } 210 211 static void gre_err(struct sk_buff *skb, u32 info) 212 { 213 /* All the routers (except for Linux) return only 214 * 8 bytes of packet payload. It means, that precise relaying of 215 * ICMP in the real Internet is absolutely infeasible. 216 * 217 * Moreover, Cisco "wise men" put GRE key to the third word 218 * in GRE header. It makes impossible maintaining even soft 219 * state for keyed 220 * GRE tunnels with enabled checksum. Tell them "thank you". 221 * 222 * Well, I wonder, rfc1812 was written by Cisco employee, 223 * what the hell these idiots break standards established 224 * by themselves??? 225 */ 226 227 const struct iphdr *iph = (struct iphdr *)skb->data; 228 const int type = icmp_hdr(skb)->type; 229 const int code = icmp_hdr(skb)->code; 230 struct tnl_ptk_info tpi; 231 bool csum_err = false; 232 233 if (gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IP), 234 iph->ihl * 4) < 0) { 235 if (!csum_err) /* ignore csum errors. */ 236 return; 237 } 238 239 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { 240 ipv4_update_pmtu(skb, dev_net(skb->dev), info, 241 skb->dev->ifindex, 0, IPPROTO_GRE, 0); 242 return; 243 } 244 if (type == ICMP_REDIRECT) { 245 ipv4_redirect(skb, dev_net(skb->dev), skb->dev->ifindex, 0, 246 IPPROTO_GRE, 0); 247 return; 248 } 249 250 ipgre_err(skb, info, &tpi); 251 } 252 253 static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi, 254 int gre_hdr_len) 255 { 256 struct net *net = dev_net(skb->dev); 257 struct metadata_dst *tun_dst = NULL; 258 struct ip_tunnel_net *itn; 259 struct ip_tunnel *tunnel; 260 struct erspanhdr *ershdr; 261 const struct iphdr *iph; 262 __be32 index; 263 int len; 264 265 itn = net_generic(net, erspan_net_id); 266 len = gre_hdr_len + sizeof(*ershdr); 267 268 if (unlikely(!pskb_may_pull(skb, len))) 269 return -ENOMEM; 270 271 iph = ip_hdr(skb); 272 ershdr = (struct erspanhdr *)(skb->data + gre_hdr_len); 273 274 /* The original GRE header does not have key field, 275 * Use ERSPAN 10-bit session ID as key. 276 */ 277 tpi->key = cpu_to_be32(ntohs(ershdr->session_id) & ID_MASK); 278 index = ershdr->md.index; 279 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, 280 tpi->flags | TUNNEL_KEY, 281 iph->saddr, iph->daddr, tpi->key); 282 283 if (tunnel) { 284 if (__iptunnel_pull_header(skb, 285 gre_hdr_len + sizeof(*ershdr), 286 htons(ETH_P_TEB), 287 false, false) < 0) 288 goto drop; 289 290 if (tunnel->collect_md) { 291 struct ip_tunnel_info *info; 292 struct erspan_metadata *md; 293 __be64 tun_id; 294 __be16 flags; 295 296 tpi->flags |= TUNNEL_KEY; 297 flags = tpi->flags; 298 tun_id = key32_to_tunnel_id(tpi->key); 299 300 tun_dst = ip_tun_rx_dst(skb, flags, 301 tun_id, sizeof(*md)); 302 if (!tun_dst) 303 return PACKET_REJECT; 304 305 md = ip_tunnel_info_opts(&tun_dst->u.tun_info); 306 if (!md) 307 return PACKET_REJECT; 308 309 md->index = index; 310 info = &tun_dst->u.tun_info; 311 info->key.tun_flags |= TUNNEL_ERSPAN_OPT; 312 info->options_len = sizeof(*md); 313 } else { 314 tunnel->index = ntohl(index); 315 } 316 317 skb_reset_mac_header(skb); 318 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error); 319 return PACKET_RCVD; 320 } 321 drop: 322 kfree_skb(skb); 323 return PACKET_RCVD; 324 } 325 326 static int __ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi, 327 struct ip_tunnel_net *itn, int hdr_len, bool raw_proto) 328 { 329 struct metadata_dst *tun_dst = NULL; 330 const struct iphdr *iph; 331 struct ip_tunnel *tunnel; 332 333 iph = ip_hdr(skb); 334 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags, 335 iph->saddr, iph->daddr, tpi->key); 336 337 if (tunnel) { 338 if (__iptunnel_pull_header(skb, hdr_len, tpi->proto, 339 raw_proto, false) < 0) 340 goto drop; 341 342 if (tunnel->dev->type != ARPHRD_NONE) 343 skb_pop_mac_header(skb); 344 else 345 skb_reset_mac_header(skb); 346 if (tunnel->collect_md) { 347 __be16 flags; 348 __be64 tun_id; 349 350 flags = tpi->flags & (TUNNEL_CSUM | TUNNEL_KEY); 351 tun_id = key32_to_tunnel_id(tpi->key); 352 tun_dst = ip_tun_rx_dst(skb, flags, tun_id, 0); 353 if (!tun_dst) 354 return PACKET_REJECT; 355 } 356 357 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error); 358 return PACKET_RCVD; 359 } 360 return PACKET_NEXT; 361 362 drop: 363 kfree_skb(skb); 364 return PACKET_RCVD; 365 } 366 367 static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi, 368 int hdr_len) 369 { 370 struct net *net = dev_net(skb->dev); 371 struct ip_tunnel_net *itn; 372 int res; 373 374 if (tpi->proto == htons(ETH_P_TEB)) 375 itn = net_generic(net, gre_tap_net_id); 376 else 377 itn = net_generic(net, ipgre_net_id); 378 379 res = __ipgre_rcv(skb, tpi, itn, hdr_len, false); 380 if (res == PACKET_NEXT && tpi->proto == htons(ETH_P_TEB)) { 381 /* ipgre tunnels in collect metadata mode should receive 382 * also ETH_P_TEB traffic. 383 */ 384 itn = net_generic(net, ipgre_net_id); 385 res = __ipgre_rcv(skb, tpi, itn, hdr_len, true); 386 } 387 return res; 388 } 389 390 static int gre_rcv(struct sk_buff *skb) 391 { 392 struct tnl_ptk_info tpi; 393 bool csum_err = false; 394 int hdr_len; 395 396 #ifdef CONFIG_NET_IPGRE_BROADCAST 397 if (ipv4_is_multicast(ip_hdr(skb)->daddr)) { 398 /* Looped back packet, drop it! */ 399 if (rt_is_output_route(skb_rtable(skb))) 400 goto drop; 401 } 402 #endif 403 404 hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IP), 0); 405 if (hdr_len < 0) 406 goto drop; 407 408 if (unlikely(tpi.proto == htons(ETH_P_ERSPAN))) { 409 if (erspan_rcv(skb, &tpi, hdr_len) == PACKET_RCVD) 410 return 0; 411 } 412 413 if (ipgre_rcv(skb, &tpi, hdr_len) == PACKET_RCVD) 414 return 0; 415 416 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 417 drop: 418 kfree_skb(skb); 419 return 0; 420 } 421 422 static void __gre_xmit(struct sk_buff *skb, struct net_device *dev, 423 const struct iphdr *tnl_params, 424 __be16 proto) 425 { 426 struct ip_tunnel *tunnel = netdev_priv(dev); 427 428 if (tunnel->parms.o_flags & TUNNEL_SEQ) 429 tunnel->o_seqno++; 430 431 /* Push GRE header. */ 432 gre_build_header(skb, tunnel->tun_hlen, 433 tunnel->parms.o_flags, proto, tunnel->parms.o_key, 434 htonl(tunnel->o_seqno)); 435 436 ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol); 437 } 438 439 static int gre_handle_offloads(struct sk_buff *skb, bool csum) 440 { 441 return iptunnel_handle_offloads(skb, csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE); 442 } 443 444 static struct rtable *gre_get_rt(struct sk_buff *skb, 445 struct net_device *dev, 446 struct flowi4 *fl, 447 const struct ip_tunnel_key *key) 448 { 449 struct net *net = dev_net(dev); 450 451 memset(fl, 0, sizeof(*fl)); 452 fl->daddr = key->u.ipv4.dst; 453 fl->saddr = key->u.ipv4.src; 454 fl->flowi4_tos = RT_TOS(key->tos); 455 fl->flowi4_mark = skb->mark; 456 fl->flowi4_proto = IPPROTO_GRE; 457 458 return ip_route_output_key(net, fl); 459 } 460 461 static struct rtable *prepare_fb_xmit(struct sk_buff *skb, 462 struct net_device *dev, 463 struct flowi4 *fl, 464 int tunnel_hlen) 465 { 466 struct ip_tunnel_info *tun_info; 467 const struct ip_tunnel_key *key; 468 struct rtable *rt = NULL; 469 int min_headroom; 470 bool use_cache; 471 int err; 472 473 tun_info = skb_tunnel_info(skb); 474 key = &tun_info->key; 475 use_cache = ip_tunnel_dst_cache_usable(skb, tun_info); 476 477 if (use_cache) 478 rt = dst_cache_get_ip4(&tun_info->dst_cache, &fl->saddr); 479 if (!rt) { 480 rt = gre_get_rt(skb, dev, fl, key); 481 if (IS_ERR(rt)) 482 goto err_free_skb; 483 if (use_cache) 484 dst_cache_set_ip4(&tun_info->dst_cache, &rt->dst, 485 fl->saddr); 486 } 487 488 min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len 489 + tunnel_hlen + sizeof(struct iphdr); 490 if (skb_headroom(skb) < min_headroom || skb_header_cloned(skb)) { 491 int head_delta = SKB_DATA_ALIGN(min_headroom - 492 skb_headroom(skb) + 493 16); 494 err = pskb_expand_head(skb, max_t(int, head_delta, 0), 495 0, GFP_ATOMIC); 496 if (unlikely(err)) 497 goto err_free_rt; 498 } 499 return rt; 500 501 err_free_rt: 502 ip_rt_put(rt); 503 err_free_skb: 504 kfree_skb(skb); 505 dev->stats.tx_dropped++; 506 return NULL; 507 } 508 509 static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev, 510 __be16 proto) 511 { 512 struct ip_tunnel_info *tun_info; 513 const struct ip_tunnel_key *key; 514 struct rtable *rt = NULL; 515 struct flowi4 fl; 516 int tunnel_hlen; 517 __be16 df, flags; 518 519 tun_info = skb_tunnel_info(skb); 520 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) || 521 ip_tunnel_info_af(tun_info) != AF_INET)) 522 goto err_free_skb; 523 524 key = &tun_info->key; 525 tunnel_hlen = gre_calc_hlen(key->tun_flags); 526 527 rt = prepare_fb_xmit(skb, dev, &fl, tunnel_hlen); 528 if (!rt) 529 return; 530 531 /* Push Tunnel header. */ 532 if (gre_handle_offloads(skb, !!(tun_info->key.tun_flags & TUNNEL_CSUM))) 533 goto err_free_rt; 534 535 flags = tun_info->key.tun_flags & (TUNNEL_CSUM | TUNNEL_KEY); 536 gre_build_header(skb, tunnel_hlen, flags, proto, 537 tunnel_id_to_key32(tun_info->key.tun_id), 0); 538 539 df = key->tun_flags & TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0; 540 541 iptunnel_xmit(skb->sk, rt, skb, fl.saddr, key->u.ipv4.dst, IPPROTO_GRE, 542 key->tos, key->ttl, df, false); 543 return; 544 545 err_free_rt: 546 ip_rt_put(rt); 547 err_free_skb: 548 kfree_skb(skb); 549 dev->stats.tx_dropped++; 550 } 551 552 static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev, 553 __be16 proto) 554 { 555 struct ip_tunnel *tunnel = netdev_priv(dev); 556 struct ip_tunnel_info *tun_info; 557 const struct ip_tunnel_key *key; 558 struct erspan_metadata *md; 559 struct rtable *rt = NULL; 560 bool truncate = false; 561 struct flowi4 fl; 562 int tunnel_hlen; 563 __be16 df; 564 565 tun_info = skb_tunnel_info(skb); 566 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) || 567 ip_tunnel_info_af(tun_info) != AF_INET)) 568 goto err_free_skb; 569 570 key = &tun_info->key; 571 572 /* ERSPAN has fixed 8 byte GRE header */ 573 tunnel_hlen = 8 + sizeof(struct erspanhdr); 574 575 rt = prepare_fb_xmit(skb, dev, &fl, tunnel_hlen); 576 if (!rt) 577 return; 578 579 if (gre_handle_offloads(skb, false)) 580 goto err_free_rt; 581 582 if (skb->len > dev->mtu) { 583 pskb_trim(skb, dev->mtu); 584 truncate = true; 585 } 586 587 md = ip_tunnel_info_opts(tun_info); 588 if (!md) 589 goto err_free_rt; 590 591 erspan_build_header(skb, tunnel_id_to_key32(key->tun_id), 592 ntohl(md->index), truncate); 593 594 gre_build_header(skb, 8, TUNNEL_SEQ, 595 htons(ETH_P_ERSPAN), 0, htonl(tunnel->o_seqno++)); 596 597 df = key->tun_flags & TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0; 598 599 iptunnel_xmit(skb->sk, rt, skb, fl.saddr, key->u.ipv4.dst, IPPROTO_GRE, 600 key->tos, key->ttl, df, false); 601 return; 602 603 err_free_rt: 604 ip_rt_put(rt); 605 err_free_skb: 606 kfree_skb(skb); 607 dev->stats.tx_dropped++; 608 } 609 610 static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb) 611 { 612 struct ip_tunnel_info *info = skb_tunnel_info(skb); 613 struct rtable *rt; 614 struct flowi4 fl4; 615 616 if (ip_tunnel_info_af(info) != AF_INET) 617 return -EINVAL; 618 619 rt = gre_get_rt(skb, dev, &fl4, &info->key); 620 if (IS_ERR(rt)) 621 return PTR_ERR(rt); 622 623 ip_rt_put(rt); 624 info->key.u.ipv4.src = fl4.saddr; 625 return 0; 626 } 627 628 static netdev_tx_t ipgre_xmit(struct sk_buff *skb, 629 struct net_device *dev) 630 { 631 struct ip_tunnel *tunnel = netdev_priv(dev); 632 const struct iphdr *tnl_params; 633 634 if (tunnel->collect_md) { 635 gre_fb_xmit(skb, dev, skb->protocol); 636 return NETDEV_TX_OK; 637 } 638 639 if (dev->header_ops) { 640 /* Need space for new headers */ 641 if (skb_cow_head(skb, dev->needed_headroom - 642 (tunnel->hlen + sizeof(struct iphdr)))) 643 goto free_skb; 644 645 tnl_params = (const struct iphdr *)skb->data; 646 647 /* Pull skb since ip_tunnel_xmit() needs skb->data pointing 648 * to gre header. 649 */ 650 skb_pull(skb, tunnel->hlen + sizeof(struct iphdr)); 651 skb_reset_mac_header(skb); 652 } else { 653 if (skb_cow_head(skb, dev->needed_headroom)) 654 goto free_skb; 655 656 tnl_params = &tunnel->parms.iph; 657 } 658 659 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM))) 660 goto free_skb; 661 662 __gre_xmit(skb, dev, tnl_params, skb->protocol); 663 return NETDEV_TX_OK; 664 665 free_skb: 666 kfree_skb(skb); 667 dev->stats.tx_dropped++; 668 return NETDEV_TX_OK; 669 } 670 671 static inline u8 tos_to_cos(u8 tos) 672 { 673 u8 dscp, cos; 674 675 dscp = tos >> 2; 676 cos = dscp >> 3; 677 return cos; 678 } 679 680 static void erspan_build_header(struct sk_buff *skb, 681 __be32 id, u32 index, bool truncate) 682 { 683 struct iphdr *iphdr = ip_hdr(skb); 684 struct ethhdr *eth = eth_hdr(skb); 685 enum erspan_encap_type enc_type; 686 struct erspanhdr *ershdr; 687 struct qtag_prefix { 688 __be16 eth_type; 689 __be16 tci; 690 } *qp; 691 u16 vlan_tci = 0; 692 693 enc_type = ERSPAN_ENCAP_NOVLAN; 694 695 /* If mirrored packet has vlan tag, extract tci and 696 * perserve vlan header in the mirrored frame. 697 */ 698 if (eth->h_proto == htons(ETH_P_8021Q)) { 699 qp = (struct qtag_prefix *)(skb->data + 2 * ETH_ALEN); 700 vlan_tci = ntohs(qp->tci); 701 enc_type = ERSPAN_ENCAP_INFRAME; 702 } 703 704 skb_push(skb, sizeof(*ershdr)); 705 ershdr = (struct erspanhdr *)skb->data; 706 memset(ershdr, 0, sizeof(*ershdr)); 707 708 ershdr->ver_vlan = htons((vlan_tci & VLAN_MASK) | 709 (ERSPAN_VERSION << VER_OFFSET)); 710 ershdr->session_id = htons((u16)(ntohl(id) & ID_MASK) | 711 ((tos_to_cos(iphdr->tos) << COS_OFFSET) & COS_MASK) | 712 (enc_type << EN_OFFSET & EN_MASK) | 713 ((truncate << T_OFFSET) & T_MASK)); 714 ershdr->md.index = htonl(index & INDEX_MASK); 715 } 716 717 static netdev_tx_t erspan_xmit(struct sk_buff *skb, 718 struct net_device *dev) 719 { 720 struct ip_tunnel *tunnel = netdev_priv(dev); 721 bool truncate = false; 722 723 if (tunnel->collect_md) { 724 erspan_fb_xmit(skb, dev, skb->protocol); 725 return NETDEV_TX_OK; 726 } 727 728 if (gre_handle_offloads(skb, false)) 729 goto free_skb; 730 731 if (skb_cow_head(skb, dev->needed_headroom)) 732 goto free_skb; 733 734 if (skb->len - dev->hard_header_len > dev->mtu) { 735 pskb_trim(skb, dev->mtu); 736 truncate = true; 737 } 738 739 /* Push ERSPAN header */ 740 erspan_build_header(skb, tunnel->parms.o_key, tunnel->index, truncate); 741 tunnel->parms.o_flags &= ~TUNNEL_KEY; 742 __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_ERSPAN)); 743 return NETDEV_TX_OK; 744 745 free_skb: 746 kfree_skb(skb); 747 dev->stats.tx_dropped++; 748 return NETDEV_TX_OK; 749 } 750 751 static netdev_tx_t gre_tap_xmit(struct sk_buff *skb, 752 struct net_device *dev) 753 { 754 struct ip_tunnel *tunnel = netdev_priv(dev); 755 756 if (tunnel->collect_md) { 757 gre_fb_xmit(skb, dev, htons(ETH_P_TEB)); 758 return NETDEV_TX_OK; 759 } 760 761 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM))) 762 goto free_skb; 763 764 if (skb_cow_head(skb, dev->needed_headroom)) 765 goto free_skb; 766 767 __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB)); 768 return NETDEV_TX_OK; 769 770 free_skb: 771 kfree_skb(skb); 772 dev->stats.tx_dropped++; 773 return NETDEV_TX_OK; 774 } 775 776 static int ipgre_tunnel_ioctl(struct net_device *dev, 777 struct ifreq *ifr, int cmd) 778 { 779 int err; 780 struct ip_tunnel_parm p; 781 782 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 783 return -EFAULT; 784 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) { 785 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE || 786 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) || 787 ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))) 788 return -EINVAL; 789 } 790 p.i_flags = gre_flags_to_tnl_flags(p.i_flags); 791 p.o_flags = gre_flags_to_tnl_flags(p.o_flags); 792 793 err = ip_tunnel_ioctl(dev, &p, cmd); 794 if (err) 795 return err; 796 797 p.i_flags = gre_tnl_flags_to_gre_flags(p.i_flags); 798 p.o_flags = gre_tnl_flags_to_gre_flags(p.o_flags); 799 800 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 801 return -EFAULT; 802 return 0; 803 } 804 805 /* Nice toy. Unfortunately, useless in real life :-) 806 It allows to construct virtual multiprotocol broadcast "LAN" 807 over the Internet, provided multicast routing is tuned. 808 809 810 I have no idea was this bicycle invented before me, 811 so that I had to set ARPHRD_IPGRE to a random value. 812 I have an impression, that Cisco could make something similar, 813 but this feature is apparently missing in IOS<=11.2(8). 814 815 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks 816 with broadcast 224.66.66.66. If you have access to mbone, play with me :-) 817 818 ping -t 255 224.66.66.66 819 820 If nobody answers, mbone does not work. 821 822 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255 823 ip addr add 10.66.66.<somewhat>/24 dev Universe 824 ifconfig Universe up 825 ifconfig Universe add fe80::<Your_real_addr>/10 826 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96 827 ftp 10.66.66.66 828 ... 829 ftp fec0:6666:6666::193.233.7.65 830 ... 831 */ 832 static int ipgre_header(struct sk_buff *skb, struct net_device *dev, 833 unsigned short type, 834 const void *daddr, const void *saddr, unsigned int len) 835 { 836 struct ip_tunnel *t = netdev_priv(dev); 837 struct iphdr *iph; 838 struct gre_base_hdr *greh; 839 840 iph = skb_push(skb, t->hlen + sizeof(*iph)); 841 greh = (struct gre_base_hdr *)(iph+1); 842 greh->flags = gre_tnl_flags_to_gre_flags(t->parms.o_flags); 843 greh->protocol = htons(type); 844 845 memcpy(iph, &t->parms.iph, sizeof(struct iphdr)); 846 847 /* Set the source hardware address. */ 848 if (saddr) 849 memcpy(&iph->saddr, saddr, 4); 850 if (daddr) 851 memcpy(&iph->daddr, daddr, 4); 852 if (iph->daddr) 853 return t->hlen + sizeof(*iph); 854 855 return -(t->hlen + sizeof(*iph)); 856 } 857 858 static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr) 859 { 860 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb); 861 memcpy(haddr, &iph->saddr, 4); 862 return 4; 863 } 864 865 static const struct header_ops ipgre_header_ops = { 866 .create = ipgre_header, 867 .parse = ipgre_header_parse, 868 }; 869 870 #ifdef CONFIG_NET_IPGRE_BROADCAST 871 static int ipgre_open(struct net_device *dev) 872 { 873 struct ip_tunnel *t = netdev_priv(dev); 874 875 if (ipv4_is_multicast(t->parms.iph.daddr)) { 876 struct flowi4 fl4; 877 struct rtable *rt; 878 879 rt = ip_route_output_gre(t->net, &fl4, 880 t->parms.iph.daddr, 881 t->parms.iph.saddr, 882 t->parms.o_key, 883 RT_TOS(t->parms.iph.tos), 884 t->parms.link); 885 if (IS_ERR(rt)) 886 return -EADDRNOTAVAIL; 887 dev = rt->dst.dev; 888 ip_rt_put(rt); 889 if (!__in_dev_get_rtnl(dev)) 890 return -EADDRNOTAVAIL; 891 t->mlink = dev->ifindex; 892 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr); 893 } 894 return 0; 895 } 896 897 static int ipgre_close(struct net_device *dev) 898 { 899 struct ip_tunnel *t = netdev_priv(dev); 900 901 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) { 902 struct in_device *in_dev; 903 in_dev = inetdev_by_index(t->net, t->mlink); 904 if (in_dev) 905 ip_mc_dec_group(in_dev, t->parms.iph.daddr); 906 } 907 return 0; 908 } 909 #endif 910 911 static const struct net_device_ops ipgre_netdev_ops = { 912 .ndo_init = ipgre_tunnel_init, 913 .ndo_uninit = ip_tunnel_uninit, 914 #ifdef CONFIG_NET_IPGRE_BROADCAST 915 .ndo_open = ipgre_open, 916 .ndo_stop = ipgre_close, 917 #endif 918 .ndo_start_xmit = ipgre_xmit, 919 .ndo_do_ioctl = ipgre_tunnel_ioctl, 920 .ndo_change_mtu = ip_tunnel_change_mtu, 921 .ndo_get_stats64 = ip_tunnel_get_stats64, 922 .ndo_get_iflink = ip_tunnel_get_iflink, 923 }; 924 925 #define GRE_FEATURES (NETIF_F_SG | \ 926 NETIF_F_FRAGLIST | \ 927 NETIF_F_HIGHDMA | \ 928 NETIF_F_HW_CSUM) 929 930 static void ipgre_tunnel_setup(struct net_device *dev) 931 { 932 dev->netdev_ops = &ipgre_netdev_ops; 933 dev->type = ARPHRD_IPGRE; 934 ip_tunnel_setup(dev, ipgre_net_id); 935 } 936 937 static void __gre_tunnel_init(struct net_device *dev) 938 { 939 struct ip_tunnel *tunnel; 940 int t_hlen; 941 942 tunnel = netdev_priv(dev); 943 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags); 944 tunnel->parms.iph.protocol = IPPROTO_GRE; 945 946 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen; 947 948 t_hlen = tunnel->hlen + sizeof(struct iphdr); 949 950 dev->needed_headroom = LL_MAX_HEADER + t_hlen + 4; 951 dev->mtu = ETH_DATA_LEN - t_hlen - 4; 952 953 dev->features |= GRE_FEATURES; 954 dev->hw_features |= GRE_FEATURES; 955 956 if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) { 957 /* TCP offload with GRE SEQ is not supported, nor 958 * can we support 2 levels of outer headers requiring 959 * an update. 960 */ 961 if (!(tunnel->parms.o_flags & TUNNEL_CSUM) || 962 (tunnel->encap.type == TUNNEL_ENCAP_NONE)) { 963 dev->features |= NETIF_F_GSO_SOFTWARE; 964 dev->hw_features |= NETIF_F_GSO_SOFTWARE; 965 } 966 967 /* Can use a lockless transmit, unless we generate 968 * output sequences 969 */ 970 dev->features |= NETIF_F_LLTX; 971 } 972 } 973 974 static int ipgre_tunnel_init(struct net_device *dev) 975 { 976 struct ip_tunnel *tunnel = netdev_priv(dev); 977 struct iphdr *iph = &tunnel->parms.iph; 978 979 __gre_tunnel_init(dev); 980 981 memcpy(dev->dev_addr, &iph->saddr, 4); 982 memcpy(dev->broadcast, &iph->daddr, 4); 983 984 dev->flags = IFF_NOARP; 985 netif_keep_dst(dev); 986 dev->addr_len = 4; 987 988 if (iph->daddr && !tunnel->collect_md) { 989 #ifdef CONFIG_NET_IPGRE_BROADCAST 990 if (ipv4_is_multicast(iph->daddr)) { 991 if (!iph->saddr) 992 return -EINVAL; 993 dev->flags = IFF_BROADCAST; 994 dev->header_ops = &ipgre_header_ops; 995 } 996 #endif 997 } else if (!tunnel->collect_md) { 998 dev->header_ops = &ipgre_header_ops; 999 } 1000 1001 return ip_tunnel_init(dev); 1002 } 1003 1004 static const struct gre_protocol ipgre_protocol = { 1005 .handler = gre_rcv, 1006 .err_handler = gre_err, 1007 }; 1008 1009 static int __net_init ipgre_init_net(struct net *net) 1010 { 1011 return ip_tunnel_init_net(net, ipgre_net_id, &ipgre_link_ops, NULL); 1012 } 1013 1014 static void __net_exit ipgre_exit_net(struct net *net) 1015 { 1016 struct ip_tunnel_net *itn = net_generic(net, ipgre_net_id); 1017 ip_tunnel_delete_net(itn, &ipgre_link_ops); 1018 } 1019 1020 static struct pernet_operations ipgre_net_ops = { 1021 .init = ipgre_init_net, 1022 .exit = ipgre_exit_net, 1023 .id = &ipgre_net_id, 1024 .size = sizeof(struct ip_tunnel_net), 1025 }; 1026 1027 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[], 1028 struct netlink_ext_ack *extack) 1029 { 1030 __be16 flags; 1031 1032 if (!data) 1033 return 0; 1034 1035 flags = 0; 1036 if (data[IFLA_GRE_IFLAGS]) 1037 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); 1038 if (data[IFLA_GRE_OFLAGS]) 1039 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); 1040 if (flags & (GRE_VERSION|GRE_ROUTING)) 1041 return -EINVAL; 1042 1043 if (data[IFLA_GRE_COLLECT_METADATA] && 1044 data[IFLA_GRE_ENCAP_TYPE] && 1045 nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]) != TUNNEL_ENCAP_NONE) 1046 return -EINVAL; 1047 1048 return 0; 1049 } 1050 1051 static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[], 1052 struct netlink_ext_ack *extack) 1053 { 1054 __be32 daddr; 1055 1056 if (tb[IFLA_ADDRESS]) { 1057 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) 1058 return -EINVAL; 1059 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) 1060 return -EADDRNOTAVAIL; 1061 } 1062 1063 if (!data) 1064 goto out; 1065 1066 if (data[IFLA_GRE_REMOTE]) { 1067 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4); 1068 if (!daddr) 1069 return -EINVAL; 1070 } 1071 1072 out: 1073 return ipgre_tunnel_validate(tb, data, extack); 1074 } 1075 1076 static int erspan_validate(struct nlattr *tb[], struct nlattr *data[], 1077 struct netlink_ext_ack *extack) 1078 { 1079 __be16 flags = 0; 1080 int ret; 1081 1082 if (!data) 1083 return 0; 1084 1085 ret = ipgre_tap_validate(tb, data, extack); 1086 if (ret) 1087 return ret; 1088 1089 /* ERSPAN should only have GRE sequence and key flag */ 1090 if (data[IFLA_GRE_OFLAGS]) 1091 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); 1092 if (data[IFLA_GRE_IFLAGS]) 1093 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); 1094 if (!data[IFLA_GRE_COLLECT_METADATA] && 1095 flags != (GRE_SEQ | GRE_KEY)) 1096 return -EINVAL; 1097 1098 /* ERSPAN Session ID only has 10-bit. Since we reuse 1099 * 32-bit key field as ID, check it's range. 1100 */ 1101 if (data[IFLA_GRE_IKEY] && 1102 (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK)) 1103 return -EINVAL; 1104 1105 if (data[IFLA_GRE_OKEY] && 1106 (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK)) 1107 return -EINVAL; 1108 1109 return 0; 1110 } 1111 1112 static int ipgre_netlink_parms(struct net_device *dev, 1113 struct nlattr *data[], 1114 struct nlattr *tb[], 1115 struct ip_tunnel_parm *parms, 1116 __u32 *fwmark) 1117 { 1118 struct ip_tunnel *t = netdev_priv(dev); 1119 1120 memset(parms, 0, sizeof(*parms)); 1121 1122 parms->iph.protocol = IPPROTO_GRE; 1123 1124 if (!data) 1125 return 0; 1126 1127 if (data[IFLA_GRE_LINK]) 1128 parms->link = nla_get_u32(data[IFLA_GRE_LINK]); 1129 1130 if (data[IFLA_GRE_IFLAGS]) 1131 parms->i_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_IFLAGS])); 1132 1133 if (data[IFLA_GRE_OFLAGS]) 1134 parms->o_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_OFLAGS])); 1135 1136 if (data[IFLA_GRE_IKEY]) 1137 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]); 1138 1139 if (data[IFLA_GRE_OKEY]) 1140 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]); 1141 1142 if (data[IFLA_GRE_LOCAL]) 1143 parms->iph.saddr = nla_get_in_addr(data[IFLA_GRE_LOCAL]); 1144 1145 if (data[IFLA_GRE_REMOTE]) 1146 parms->iph.daddr = nla_get_in_addr(data[IFLA_GRE_REMOTE]); 1147 1148 if (data[IFLA_GRE_TTL]) 1149 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]); 1150 1151 if (data[IFLA_GRE_TOS]) 1152 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]); 1153 1154 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC])) { 1155 if (t->ignore_df) 1156 return -EINVAL; 1157 parms->iph.frag_off = htons(IP_DF); 1158 } 1159 1160 if (data[IFLA_GRE_COLLECT_METADATA]) { 1161 t->collect_md = true; 1162 if (dev->type == ARPHRD_IPGRE) 1163 dev->type = ARPHRD_NONE; 1164 } 1165 1166 if (data[IFLA_GRE_IGNORE_DF]) { 1167 if (nla_get_u8(data[IFLA_GRE_IGNORE_DF]) 1168 && (parms->iph.frag_off & htons(IP_DF))) 1169 return -EINVAL; 1170 t->ignore_df = !!nla_get_u8(data[IFLA_GRE_IGNORE_DF]); 1171 } 1172 1173 if (data[IFLA_GRE_FWMARK]) 1174 *fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]); 1175 1176 if (data[IFLA_GRE_ERSPAN_INDEX]) { 1177 t->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]); 1178 1179 if (t->index & ~INDEX_MASK) 1180 return -EINVAL; 1181 } 1182 1183 return 0; 1184 } 1185 1186 /* This function returns true when ENCAP attributes are present in the nl msg */ 1187 static bool ipgre_netlink_encap_parms(struct nlattr *data[], 1188 struct ip_tunnel_encap *ipencap) 1189 { 1190 bool ret = false; 1191 1192 memset(ipencap, 0, sizeof(*ipencap)); 1193 1194 if (!data) 1195 return ret; 1196 1197 if (data[IFLA_GRE_ENCAP_TYPE]) { 1198 ret = true; 1199 ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]); 1200 } 1201 1202 if (data[IFLA_GRE_ENCAP_FLAGS]) { 1203 ret = true; 1204 ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]); 1205 } 1206 1207 if (data[IFLA_GRE_ENCAP_SPORT]) { 1208 ret = true; 1209 ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]); 1210 } 1211 1212 if (data[IFLA_GRE_ENCAP_DPORT]) { 1213 ret = true; 1214 ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]); 1215 } 1216 1217 return ret; 1218 } 1219 1220 static int gre_tap_init(struct net_device *dev) 1221 { 1222 __gre_tunnel_init(dev); 1223 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1224 netif_keep_dst(dev); 1225 1226 return ip_tunnel_init(dev); 1227 } 1228 1229 static const struct net_device_ops gre_tap_netdev_ops = { 1230 .ndo_init = gre_tap_init, 1231 .ndo_uninit = ip_tunnel_uninit, 1232 .ndo_start_xmit = gre_tap_xmit, 1233 .ndo_set_mac_address = eth_mac_addr, 1234 .ndo_validate_addr = eth_validate_addr, 1235 .ndo_change_mtu = ip_tunnel_change_mtu, 1236 .ndo_get_stats64 = ip_tunnel_get_stats64, 1237 .ndo_get_iflink = ip_tunnel_get_iflink, 1238 .ndo_fill_metadata_dst = gre_fill_metadata_dst, 1239 }; 1240 1241 static int erspan_tunnel_init(struct net_device *dev) 1242 { 1243 struct ip_tunnel *tunnel = netdev_priv(dev); 1244 int t_hlen; 1245 1246 tunnel->tun_hlen = 8; 1247 tunnel->parms.iph.protocol = IPPROTO_GRE; 1248 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen + 1249 sizeof(struct erspanhdr); 1250 t_hlen = tunnel->hlen + sizeof(struct iphdr); 1251 1252 dev->needed_headroom = LL_MAX_HEADER + t_hlen + 4; 1253 dev->mtu = ETH_DATA_LEN - t_hlen - 4; 1254 dev->features |= GRE_FEATURES; 1255 dev->hw_features |= GRE_FEATURES; 1256 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1257 netif_keep_dst(dev); 1258 1259 return ip_tunnel_init(dev); 1260 } 1261 1262 static const struct net_device_ops erspan_netdev_ops = { 1263 .ndo_init = erspan_tunnel_init, 1264 .ndo_uninit = ip_tunnel_uninit, 1265 .ndo_start_xmit = erspan_xmit, 1266 .ndo_set_mac_address = eth_mac_addr, 1267 .ndo_validate_addr = eth_validate_addr, 1268 .ndo_change_mtu = ip_tunnel_change_mtu, 1269 .ndo_get_stats64 = ip_tunnel_get_stats64, 1270 .ndo_get_iflink = ip_tunnel_get_iflink, 1271 .ndo_fill_metadata_dst = gre_fill_metadata_dst, 1272 }; 1273 1274 static void ipgre_tap_setup(struct net_device *dev) 1275 { 1276 ether_setup(dev); 1277 dev->netdev_ops = &gre_tap_netdev_ops; 1278 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 1279 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1280 ip_tunnel_setup(dev, gre_tap_net_id); 1281 } 1282 1283 static int ipgre_newlink(struct net *src_net, struct net_device *dev, 1284 struct nlattr *tb[], struct nlattr *data[], 1285 struct netlink_ext_ack *extack) 1286 { 1287 struct ip_tunnel_parm p; 1288 struct ip_tunnel_encap ipencap; 1289 __u32 fwmark = 0; 1290 int err; 1291 1292 if (ipgre_netlink_encap_parms(data, &ipencap)) { 1293 struct ip_tunnel *t = netdev_priv(dev); 1294 err = ip_tunnel_encap_setup(t, &ipencap); 1295 1296 if (err < 0) 1297 return err; 1298 } 1299 1300 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark); 1301 if (err < 0) 1302 return err; 1303 return ip_tunnel_newlink(dev, tb, &p, fwmark); 1304 } 1305 1306 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[], 1307 struct nlattr *data[], 1308 struct netlink_ext_ack *extack) 1309 { 1310 struct ip_tunnel *t = netdev_priv(dev); 1311 struct ip_tunnel_parm p; 1312 struct ip_tunnel_encap ipencap; 1313 __u32 fwmark = t->fwmark; 1314 int err; 1315 1316 if (ipgre_netlink_encap_parms(data, &ipencap)) { 1317 err = ip_tunnel_encap_setup(t, &ipencap); 1318 1319 if (err < 0) 1320 return err; 1321 } 1322 1323 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark); 1324 if (err < 0) 1325 return err; 1326 return ip_tunnel_changelink(dev, tb, &p, fwmark); 1327 } 1328 1329 static size_t ipgre_get_size(const struct net_device *dev) 1330 { 1331 return 1332 /* IFLA_GRE_LINK */ 1333 nla_total_size(4) + 1334 /* IFLA_GRE_IFLAGS */ 1335 nla_total_size(2) + 1336 /* IFLA_GRE_OFLAGS */ 1337 nla_total_size(2) + 1338 /* IFLA_GRE_IKEY */ 1339 nla_total_size(4) + 1340 /* IFLA_GRE_OKEY */ 1341 nla_total_size(4) + 1342 /* IFLA_GRE_LOCAL */ 1343 nla_total_size(4) + 1344 /* IFLA_GRE_REMOTE */ 1345 nla_total_size(4) + 1346 /* IFLA_GRE_TTL */ 1347 nla_total_size(1) + 1348 /* IFLA_GRE_TOS */ 1349 nla_total_size(1) + 1350 /* IFLA_GRE_PMTUDISC */ 1351 nla_total_size(1) + 1352 /* IFLA_GRE_ENCAP_TYPE */ 1353 nla_total_size(2) + 1354 /* IFLA_GRE_ENCAP_FLAGS */ 1355 nla_total_size(2) + 1356 /* IFLA_GRE_ENCAP_SPORT */ 1357 nla_total_size(2) + 1358 /* IFLA_GRE_ENCAP_DPORT */ 1359 nla_total_size(2) + 1360 /* IFLA_GRE_COLLECT_METADATA */ 1361 nla_total_size(0) + 1362 /* IFLA_GRE_IGNORE_DF */ 1363 nla_total_size(1) + 1364 /* IFLA_GRE_FWMARK */ 1365 nla_total_size(4) + 1366 /* IFLA_GRE_ERSPAN_INDEX */ 1367 nla_total_size(4) + 1368 0; 1369 } 1370 1371 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev) 1372 { 1373 struct ip_tunnel *t = netdev_priv(dev); 1374 struct ip_tunnel_parm *p = &t->parms; 1375 1376 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) || 1377 nla_put_be16(skb, IFLA_GRE_IFLAGS, 1378 gre_tnl_flags_to_gre_flags(p->i_flags)) || 1379 nla_put_be16(skb, IFLA_GRE_OFLAGS, 1380 gre_tnl_flags_to_gre_flags(p->o_flags)) || 1381 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) || 1382 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) || 1383 nla_put_in_addr(skb, IFLA_GRE_LOCAL, p->iph.saddr) || 1384 nla_put_in_addr(skb, IFLA_GRE_REMOTE, p->iph.daddr) || 1385 nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) || 1386 nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) || 1387 nla_put_u8(skb, IFLA_GRE_PMTUDISC, 1388 !!(p->iph.frag_off & htons(IP_DF))) || 1389 nla_put_u32(skb, IFLA_GRE_FWMARK, t->fwmark)) 1390 goto nla_put_failure; 1391 1392 if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE, 1393 t->encap.type) || 1394 nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT, 1395 t->encap.sport) || 1396 nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT, 1397 t->encap.dport) || 1398 nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS, 1399 t->encap.flags)) 1400 goto nla_put_failure; 1401 1402 if (nla_put_u8(skb, IFLA_GRE_IGNORE_DF, t->ignore_df)) 1403 goto nla_put_failure; 1404 1405 if (t->collect_md) { 1406 if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA)) 1407 goto nla_put_failure; 1408 } 1409 1410 if (t->index) 1411 if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, t->index)) 1412 goto nla_put_failure; 1413 1414 return 0; 1415 1416 nla_put_failure: 1417 return -EMSGSIZE; 1418 } 1419 1420 static void erspan_setup(struct net_device *dev) 1421 { 1422 ether_setup(dev); 1423 dev->netdev_ops = &erspan_netdev_ops; 1424 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 1425 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1426 ip_tunnel_setup(dev, erspan_net_id); 1427 } 1428 1429 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = { 1430 [IFLA_GRE_LINK] = { .type = NLA_U32 }, 1431 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 }, 1432 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 }, 1433 [IFLA_GRE_IKEY] = { .type = NLA_U32 }, 1434 [IFLA_GRE_OKEY] = { .type = NLA_U32 }, 1435 [IFLA_GRE_LOCAL] = { .len = FIELD_SIZEOF(struct iphdr, saddr) }, 1436 [IFLA_GRE_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) }, 1437 [IFLA_GRE_TTL] = { .type = NLA_U8 }, 1438 [IFLA_GRE_TOS] = { .type = NLA_U8 }, 1439 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 }, 1440 [IFLA_GRE_ENCAP_TYPE] = { .type = NLA_U16 }, 1441 [IFLA_GRE_ENCAP_FLAGS] = { .type = NLA_U16 }, 1442 [IFLA_GRE_ENCAP_SPORT] = { .type = NLA_U16 }, 1443 [IFLA_GRE_ENCAP_DPORT] = { .type = NLA_U16 }, 1444 [IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG }, 1445 [IFLA_GRE_IGNORE_DF] = { .type = NLA_U8 }, 1446 [IFLA_GRE_FWMARK] = { .type = NLA_U32 }, 1447 [IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 }, 1448 }; 1449 1450 static struct rtnl_link_ops ipgre_link_ops __read_mostly = { 1451 .kind = "gre", 1452 .maxtype = IFLA_GRE_MAX, 1453 .policy = ipgre_policy, 1454 .priv_size = sizeof(struct ip_tunnel), 1455 .setup = ipgre_tunnel_setup, 1456 .validate = ipgre_tunnel_validate, 1457 .newlink = ipgre_newlink, 1458 .changelink = ipgre_changelink, 1459 .dellink = ip_tunnel_dellink, 1460 .get_size = ipgre_get_size, 1461 .fill_info = ipgre_fill_info, 1462 .get_link_net = ip_tunnel_get_link_net, 1463 }; 1464 1465 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = { 1466 .kind = "gretap", 1467 .maxtype = IFLA_GRE_MAX, 1468 .policy = ipgre_policy, 1469 .priv_size = sizeof(struct ip_tunnel), 1470 .setup = ipgre_tap_setup, 1471 .validate = ipgre_tap_validate, 1472 .newlink = ipgre_newlink, 1473 .changelink = ipgre_changelink, 1474 .dellink = ip_tunnel_dellink, 1475 .get_size = ipgre_get_size, 1476 .fill_info = ipgre_fill_info, 1477 .get_link_net = ip_tunnel_get_link_net, 1478 }; 1479 1480 static struct rtnl_link_ops erspan_link_ops __read_mostly = { 1481 .kind = "erspan", 1482 .maxtype = IFLA_GRE_MAX, 1483 .policy = ipgre_policy, 1484 .priv_size = sizeof(struct ip_tunnel), 1485 .setup = erspan_setup, 1486 .validate = erspan_validate, 1487 .newlink = ipgre_newlink, 1488 .changelink = ipgre_changelink, 1489 .dellink = ip_tunnel_dellink, 1490 .get_size = ipgre_get_size, 1491 .fill_info = ipgre_fill_info, 1492 .get_link_net = ip_tunnel_get_link_net, 1493 }; 1494 1495 struct net_device *gretap_fb_dev_create(struct net *net, const char *name, 1496 u8 name_assign_type) 1497 { 1498 struct nlattr *tb[IFLA_MAX + 1]; 1499 struct net_device *dev; 1500 LIST_HEAD(list_kill); 1501 struct ip_tunnel *t; 1502 int err; 1503 1504 memset(&tb, 0, sizeof(tb)); 1505 1506 dev = rtnl_create_link(net, name, name_assign_type, 1507 &ipgre_tap_ops, tb); 1508 if (IS_ERR(dev)) 1509 return dev; 1510 1511 /* Configure flow based GRE device. */ 1512 t = netdev_priv(dev); 1513 t->collect_md = true; 1514 1515 err = ipgre_newlink(net, dev, tb, NULL, NULL); 1516 if (err < 0) { 1517 free_netdev(dev); 1518 return ERR_PTR(err); 1519 } 1520 1521 /* openvswitch users expect packet sizes to be unrestricted, 1522 * so set the largest MTU we can. 1523 */ 1524 err = __ip_tunnel_change_mtu(dev, IP_MAX_MTU, false); 1525 if (err) 1526 goto out; 1527 1528 err = rtnl_configure_link(dev, NULL); 1529 if (err < 0) 1530 goto out; 1531 1532 return dev; 1533 out: 1534 ip_tunnel_dellink(dev, &list_kill); 1535 unregister_netdevice_many(&list_kill); 1536 return ERR_PTR(err); 1537 } 1538 EXPORT_SYMBOL_GPL(gretap_fb_dev_create); 1539 1540 static int __net_init ipgre_tap_init_net(struct net *net) 1541 { 1542 return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, "gretap0"); 1543 } 1544 1545 static void __net_exit ipgre_tap_exit_net(struct net *net) 1546 { 1547 struct ip_tunnel_net *itn = net_generic(net, gre_tap_net_id); 1548 ip_tunnel_delete_net(itn, &ipgre_tap_ops); 1549 } 1550 1551 static struct pernet_operations ipgre_tap_net_ops = { 1552 .init = ipgre_tap_init_net, 1553 .exit = ipgre_tap_exit_net, 1554 .id = &gre_tap_net_id, 1555 .size = sizeof(struct ip_tunnel_net), 1556 }; 1557 1558 static int __net_init erspan_init_net(struct net *net) 1559 { 1560 return ip_tunnel_init_net(net, erspan_net_id, 1561 &erspan_link_ops, "erspan0"); 1562 } 1563 1564 static void __net_exit erspan_exit_net(struct net *net) 1565 { 1566 struct ip_tunnel_net *itn = net_generic(net, erspan_net_id); 1567 1568 ip_tunnel_delete_net(itn, &erspan_link_ops); 1569 } 1570 1571 static struct pernet_operations erspan_net_ops = { 1572 .init = erspan_init_net, 1573 .exit = erspan_exit_net, 1574 .id = &erspan_net_id, 1575 .size = sizeof(struct ip_tunnel_net), 1576 }; 1577 1578 static int __init ipgre_init(void) 1579 { 1580 int err; 1581 1582 pr_info("GRE over IPv4 tunneling driver\n"); 1583 1584 err = register_pernet_device(&ipgre_net_ops); 1585 if (err < 0) 1586 return err; 1587 1588 err = register_pernet_device(&ipgre_tap_net_ops); 1589 if (err < 0) 1590 goto pnet_tap_failed; 1591 1592 err = register_pernet_device(&erspan_net_ops); 1593 if (err < 0) 1594 goto pnet_erspan_failed; 1595 1596 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO); 1597 if (err < 0) { 1598 pr_info("%s: can't add protocol\n", __func__); 1599 goto add_proto_failed; 1600 } 1601 1602 err = rtnl_link_register(&ipgre_link_ops); 1603 if (err < 0) 1604 goto rtnl_link_failed; 1605 1606 err = rtnl_link_register(&ipgre_tap_ops); 1607 if (err < 0) 1608 goto tap_ops_failed; 1609 1610 err = rtnl_link_register(&erspan_link_ops); 1611 if (err < 0) 1612 goto erspan_link_failed; 1613 1614 return 0; 1615 1616 erspan_link_failed: 1617 rtnl_link_unregister(&ipgre_tap_ops); 1618 tap_ops_failed: 1619 rtnl_link_unregister(&ipgre_link_ops); 1620 rtnl_link_failed: 1621 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); 1622 add_proto_failed: 1623 unregister_pernet_device(&erspan_net_ops); 1624 pnet_erspan_failed: 1625 unregister_pernet_device(&ipgre_tap_net_ops); 1626 pnet_tap_failed: 1627 unregister_pernet_device(&ipgre_net_ops); 1628 return err; 1629 } 1630 1631 static void __exit ipgre_fini(void) 1632 { 1633 rtnl_link_unregister(&ipgre_tap_ops); 1634 rtnl_link_unregister(&ipgre_link_ops); 1635 rtnl_link_unregister(&erspan_link_ops); 1636 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); 1637 unregister_pernet_device(&ipgre_tap_net_ops); 1638 unregister_pernet_device(&ipgre_net_ops); 1639 unregister_pernet_device(&erspan_net_ops); 1640 } 1641 1642 module_init(ipgre_init); 1643 module_exit(ipgre_fini); 1644 MODULE_LICENSE("GPL"); 1645 MODULE_ALIAS_RTNL_LINK("gre"); 1646 MODULE_ALIAS_RTNL_LINK("gretap"); 1647 MODULE_ALIAS_RTNL_LINK("erspan"); 1648 MODULE_ALIAS_NETDEV("gre0"); 1649 MODULE_ALIAS_NETDEV("gretap0"); 1650 MODULE_ALIAS_NETDEV("erspan0"); 1651