1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Linux NET3: GRE over IP protocol decoder. 4 * 5 * Authors: Alexey Kuznetsov (kuznet@ms2.inr.ac.ru) 6 */ 7 8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 9 10 #include <linux/capability.h> 11 #include <linux/module.h> 12 #include <linux/types.h> 13 #include <linux/kernel.h> 14 #include <linux/slab.h> 15 #include <linux/uaccess.h> 16 #include <linux/skbuff.h> 17 #include <linux/netdevice.h> 18 #include <linux/in.h> 19 #include <linux/tcp.h> 20 #include <linux/udp.h> 21 #include <linux/if_arp.h> 22 #include <linux/if_vlan.h> 23 #include <linux/init.h> 24 #include <linux/in6.h> 25 #include <linux/inetdevice.h> 26 #include <linux/igmp.h> 27 #include <linux/netfilter_ipv4.h> 28 #include <linux/etherdevice.h> 29 #include <linux/if_ether.h> 30 31 #include <net/sock.h> 32 #include <net/ip.h> 33 #include <net/icmp.h> 34 #include <net/protocol.h> 35 #include <net/ip_tunnels.h> 36 #include <net/arp.h> 37 #include <net/checksum.h> 38 #include <net/dsfield.h> 39 #include <net/inet_ecn.h> 40 #include <net/xfrm.h> 41 #include <net/net_namespace.h> 42 #include <net/netns/generic.h> 43 #include <net/rtnetlink.h> 44 #include <net/gre.h> 45 #include <net/dst_metadata.h> 46 #include <net/erspan.h> 47 48 /* 49 Problems & solutions 50 -------------------- 51 52 1. The most important issue is detecting local dead loops. 53 They would cause complete host lockup in transmit, which 54 would be "resolved" by stack overflow or, if queueing is enabled, 55 with infinite looping in net_bh. 56 57 We cannot track such dead loops during route installation, 58 it is infeasible task. The most general solutions would be 59 to keep skb->encapsulation counter (sort of local ttl), 60 and silently drop packet when it expires. It is a good 61 solution, but it supposes maintaining new variable in ALL 62 skb, even if no tunneling is used. 63 64 Current solution: xmit_recursion breaks dead loops. This is a percpu 65 counter, since when we enter the first ndo_xmit(), cpu migration is 66 forbidden. We force an exit if this counter reaches RECURSION_LIMIT 67 68 2. Networking dead loops would not kill routers, but would really 69 kill network. IP hop limit plays role of "t->recursion" in this case, 70 if we copy it from packet being encapsulated to upper header. 71 It is very good solution, but it introduces two problems: 72 73 - Routing protocols, using packets with ttl=1 (OSPF, RIP2), 74 do not work over tunnels. 75 - traceroute does not work. I planned to relay ICMP from tunnel, 76 so that this problem would be solved and traceroute output 77 would even more informative. This idea appeared to be wrong: 78 only Linux complies to rfc1812 now (yes, guys, Linux is the only 79 true router now :-)), all routers (at least, in neighbourhood of mine) 80 return only 8 bytes of payload. It is the end. 81 82 Hence, if we want that OSPF worked or traceroute said something reasonable, 83 we should search for another solution. 84 85 One of them is to parse packet trying to detect inner encapsulation 86 made by our node. It is difficult or even impossible, especially, 87 taking into account fragmentation. TO be short, ttl is not solution at all. 88 89 Current solution: The solution was UNEXPECTEDLY SIMPLE. 90 We force DF flag on tunnels with preconfigured hop limit, 91 that is ALL. :-) Well, it does not remove the problem completely, 92 but exponential growth of network traffic is changed to linear 93 (branches, that exceed pmtu are pruned) and tunnel mtu 94 rapidly degrades to value <68, where looping stops. 95 Yes, it is not good if there exists a router in the loop, 96 which does not force DF, even when encapsulating packets have DF set. 97 But it is not our problem! Nobody could accuse us, we made 98 all that we could make. Even if it is your gated who injected 99 fatal route to network, even if it were you who configured 100 fatal static route: you are innocent. :-) 101 102 Alexey Kuznetsov. 103 */ 104 105 static bool log_ecn_error = true; 106 module_param(log_ecn_error, bool, 0644); 107 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN"); 108 109 static struct rtnl_link_ops ipgre_link_ops __read_mostly; 110 static const struct header_ops ipgre_header_ops; 111 112 static int ipgre_tunnel_init(struct net_device *dev); 113 static void erspan_build_header(struct sk_buff *skb, 114 u32 id, u32 index, 115 bool truncate, bool is_ipv4); 116 117 static unsigned int ipgre_net_id __read_mostly; 118 static unsigned int gre_tap_net_id __read_mostly; 119 static unsigned int erspan_net_id __read_mostly; 120 121 static int ipgre_err(struct sk_buff *skb, u32 info, 122 const struct tnl_ptk_info *tpi) 123 { 124 125 /* All the routers (except for Linux) return only 126 8 bytes of packet payload. It means, that precise relaying of 127 ICMP in the real Internet is absolutely infeasible. 128 129 Moreover, Cisco "wise men" put GRE key to the third word 130 in GRE header. It makes impossible maintaining even soft 131 state for keyed GRE tunnels with enabled checksum. Tell 132 them "thank you". 133 134 Well, I wonder, rfc1812 was written by Cisco employee, 135 what the hell these idiots break standards established 136 by themselves??? 137 */ 138 struct net *net = dev_net(skb->dev); 139 struct ip_tunnel_net *itn; 140 const struct iphdr *iph; 141 const int type = icmp_hdr(skb)->type; 142 const int code = icmp_hdr(skb)->code; 143 unsigned int data_len = 0; 144 struct ip_tunnel *t; 145 146 if (tpi->proto == htons(ETH_P_TEB)) 147 itn = net_generic(net, gre_tap_net_id); 148 else if (tpi->proto == htons(ETH_P_ERSPAN) || 149 tpi->proto == htons(ETH_P_ERSPAN2)) 150 itn = net_generic(net, erspan_net_id); 151 else 152 itn = net_generic(net, ipgre_net_id); 153 154 iph = (const struct iphdr *)(icmp_hdr(skb) + 1); 155 t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags, 156 iph->daddr, iph->saddr, tpi->key); 157 158 if (!t) 159 return -ENOENT; 160 161 switch (type) { 162 default: 163 case ICMP_PARAMETERPROB: 164 return 0; 165 166 case ICMP_DEST_UNREACH: 167 switch (code) { 168 case ICMP_SR_FAILED: 169 case ICMP_PORT_UNREACH: 170 /* Impossible event. */ 171 return 0; 172 default: 173 /* All others are translated to HOST_UNREACH. 174 rfc2003 contains "deep thoughts" about NET_UNREACH, 175 I believe they are just ether pollution. --ANK 176 */ 177 break; 178 } 179 break; 180 181 case ICMP_TIME_EXCEEDED: 182 if (code != ICMP_EXC_TTL) 183 return 0; 184 data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */ 185 break; 186 187 case ICMP_REDIRECT: 188 break; 189 } 190 191 #if IS_ENABLED(CONFIG_IPV6) 192 if (tpi->proto == htons(ETH_P_IPV6) && 193 !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4 + tpi->hdr_len, 194 type, data_len)) 195 return 0; 196 #endif 197 198 if (t->parms.iph.daddr == 0 || 199 ipv4_is_multicast(t->parms.iph.daddr)) 200 return 0; 201 202 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 203 return 0; 204 205 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) 206 t->err_count++; 207 else 208 t->err_count = 1; 209 t->err_time = jiffies; 210 211 return 0; 212 } 213 214 static void gre_err(struct sk_buff *skb, u32 info) 215 { 216 /* All the routers (except for Linux) return only 217 * 8 bytes of packet payload. It means, that precise relaying of 218 * ICMP in the real Internet is absolutely infeasible. 219 * 220 * Moreover, Cisco "wise men" put GRE key to the third word 221 * in GRE header. It makes impossible maintaining even soft 222 * state for keyed 223 * GRE tunnels with enabled checksum. Tell them "thank you". 224 * 225 * Well, I wonder, rfc1812 was written by Cisco employee, 226 * what the hell these idiots break standards established 227 * by themselves??? 228 */ 229 230 const struct iphdr *iph = (struct iphdr *)skb->data; 231 const int type = icmp_hdr(skb)->type; 232 const int code = icmp_hdr(skb)->code; 233 struct tnl_ptk_info tpi; 234 235 if (gre_parse_header(skb, &tpi, NULL, htons(ETH_P_IP), 236 iph->ihl * 4) < 0) 237 return; 238 239 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { 240 ipv4_update_pmtu(skb, dev_net(skb->dev), info, 241 skb->dev->ifindex, IPPROTO_GRE); 242 return; 243 } 244 if (type == ICMP_REDIRECT) { 245 ipv4_redirect(skb, dev_net(skb->dev), skb->dev->ifindex, 246 IPPROTO_GRE); 247 return; 248 } 249 250 ipgre_err(skb, info, &tpi); 251 } 252 253 static bool is_erspan_type1(int gre_hdr_len) 254 { 255 /* Both ERSPAN type I (version 0) and type II (version 1) use 256 * protocol 0x88BE, but the type I has only 4-byte GRE header, 257 * while type II has 8-byte. 258 */ 259 return gre_hdr_len == 4; 260 } 261 262 static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi, 263 int gre_hdr_len) 264 { 265 struct net *net = dev_net(skb->dev); 266 struct metadata_dst *tun_dst = NULL; 267 struct erspan_base_hdr *ershdr; 268 struct ip_tunnel_net *itn; 269 struct ip_tunnel *tunnel; 270 const struct iphdr *iph; 271 struct erspan_md2 *md2; 272 int ver; 273 int len; 274 275 itn = net_generic(net, erspan_net_id); 276 iph = ip_hdr(skb); 277 if (is_erspan_type1(gre_hdr_len)) { 278 ver = 0; 279 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, 280 tpi->flags | TUNNEL_NO_KEY, 281 iph->saddr, iph->daddr, 0); 282 } else { 283 ershdr = (struct erspan_base_hdr *)(skb->data + gre_hdr_len); 284 ver = ershdr->ver; 285 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, 286 tpi->flags | TUNNEL_KEY, 287 iph->saddr, iph->daddr, tpi->key); 288 } 289 290 if (tunnel) { 291 if (is_erspan_type1(gre_hdr_len)) 292 len = gre_hdr_len; 293 else 294 len = gre_hdr_len + erspan_hdr_len(ver); 295 296 if (unlikely(!pskb_may_pull(skb, len))) 297 return PACKET_REJECT; 298 299 if (__iptunnel_pull_header(skb, 300 len, 301 htons(ETH_P_TEB), 302 false, false) < 0) 303 goto drop; 304 305 if (tunnel->collect_md) { 306 struct erspan_metadata *pkt_md, *md; 307 struct ip_tunnel_info *info; 308 unsigned char *gh; 309 __be64 tun_id; 310 __be16 flags; 311 312 tpi->flags |= TUNNEL_KEY; 313 flags = tpi->flags; 314 tun_id = key32_to_tunnel_id(tpi->key); 315 316 tun_dst = ip_tun_rx_dst(skb, flags, 317 tun_id, sizeof(*md)); 318 if (!tun_dst) 319 return PACKET_REJECT; 320 321 /* skb can be uncloned in __iptunnel_pull_header, so 322 * old pkt_md is no longer valid and we need to reset 323 * it 324 */ 325 gh = skb_network_header(skb) + 326 skb_network_header_len(skb); 327 pkt_md = (struct erspan_metadata *)(gh + gre_hdr_len + 328 sizeof(*ershdr)); 329 md = ip_tunnel_info_opts(&tun_dst->u.tun_info); 330 md->version = ver; 331 md2 = &md->u.md2; 332 memcpy(md2, pkt_md, ver == 1 ? ERSPAN_V1_MDSIZE : 333 ERSPAN_V2_MDSIZE); 334 335 info = &tun_dst->u.tun_info; 336 info->key.tun_flags |= TUNNEL_ERSPAN_OPT; 337 info->options_len = sizeof(*md); 338 } 339 340 skb_reset_mac_header(skb); 341 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error); 342 return PACKET_RCVD; 343 } 344 return PACKET_REJECT; 345 346 drop: 347 kfree_skb(skb); 348 return PACKET_RCVD; 349 } 350 351 static int __ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi, 352 struct ip_tunnel_net *itn, int hdr_len, bool raw_proto) 353 { 354 struct metadata_dst *tun_dst = NULL; 355 const struct iphdr *iph; 356 struct ip_tunnel *tunnel; 357 358 iph = ip_hdr(skb); 359 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags, 360 iph->saddr, iph->daddr, tpi->key); 361 362 if (tunnel) { 363 const struct iphdr *tnl_params; 364 365 if (__iptunnel_pull_header(skb, hdr_len, tpi->proto, 366 raw_proto, false) < 0) 367 goto drop; 368 369 /* Special case for ipgre_header_parse(), which expects the 370 * mac_header to point to the outer IP header. 371 */ 372 if (tunnel->dev->header_ops == &ipgre_header_ops) 373 skb_pop_mac_header(skb); 374 else 375 skb_reset_mac_header(skb); 376 377 tnl_params = &tunnel->parms.iph; 378 if (tunnel->collect_md || tnl_params->daddr == 0) { 379 __be16 flags; 380 __be64 tun_id; 381 382 flags = tpi->flags & (TUNNEL_CSUM | TUNNEL_KEY); 383 tun_id = key32_to_tunnel_id(tpi->key); 384 tun_dst = ip_tun_rx_dst(skb, flags, tun_id, 0); 385 if (!tun_dst) 386 return PACKET_REJECT; 387 } 388 389 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error); 390 return PACKET_RCVD; 391 } 392 return PACKET_NEXT; 393 394 drop: 395 kfree_skb(skb); 396 return PACKET_RCVD; 397 } 398 399 static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi, 400 int hdr_len) 401 { 402 struct net *net = dev_net(skb->dev); 403 struct ip_tunnel_net *itn; 404 int res; 405 406 if (tpi->proto == htons(ETH_P_TEB)) 407 itn = net_generic(net, gre_tap_net_id); 408 else 409 itn = net_generic(net, ipgre_net_id); 410 411 res = __ipgre_rcv(skb, tpi, itn, hdr_len, false); 412 if (res == PACKET_NEXT && tpi->proto == htons(ETH_P_TEB)) { 413 /* ipgre tunnels in collect metadata mode should receive 414 * also ETH_P_TEB traffic. 415 */ 416 itn = net_generic(net, ipgre_net_id); 417 res = __ipgre_rcv(skb, tpi, itn, hdr_len, true); 418 } 419 return res; 420 } 421 422 static int gre_rcv(struct sk_buff *skb) 423 { 424 struct tnl_ptk_info tpi; 425 bool csum_err = false; 426 int hdr_len; 427 428 #ifdef CONFIG_NET_IPGRE_BROADCAST 429 if (ipv4_is_multicast(ip_hdr(skb)->daddr)) { 430 /* Looped back packet, drop it! */ 431 if (rt_is_output_route(skb_rtable(skb))) 432 goto drop; 433 } 434 #endif 435 436 hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IP), 0); 437 if (hdr_len < 0) 438 goto drop; 439 440 if (unlikely(tpi.proto == htons(ETH_P_ERSPAN) || 441 tpi.proto == htons(ETH_P_ERSPAN2))) { 442 if (erspan_rcv(skb, &tpi, hdr_len) == PACKET_RCVD) 443 return 0; 444 goto out; 445 } 446 447 if (ipgre_rcv(skb, &tpi, hdr_len) == PACKET_RCVD) 448 return 0; 449 450 out: 451 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 452 drop: 453 kfree_skb(skb); 454 return 0; 455 } 456 457 static void __gre_xmit(struct sk_buff *skb, struct net_device *dev, 458 const struct iphdr *tnl_params, 459 __be16 proto) 460 { 461 struct ip_tunnel *tunnel = netdev_priv(dev); 462 __be16 flags = tunnel->parms.o_flags; 463 464 /* Push GRE header. */ 465 gre_build_header(skb, tunnel->tun_hlen, 466 flags, proto, tunnel->parms.o_key, 467 (flags & TUNNEL_SEQ) ? htonl(atomic_fetch_inc(&tunnel->o_seqno)) : 0); 468 469 ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol); 470 } 471 472 static int gre_handle_offloads(struct sk_buff *skb, bool csum) 473 { 474 return iptunnel_handle_offloads(skb, csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE); 475 } 476 477 static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev, 478 __be16 proto) 479 { 480 struct ip_tunnel *tunnel = netdev_priv(dev); 481 struct ip_tunnel_info *tun_info; 482 const struct ip_tunnel_key *key; 483 int tunnel_hlen; 484 __be16 flags; 485 486 tun_info = skb_tunnel_info(skb); 487 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) || 488 ip_tunnel_info_af(tun_info) != AF_INET)) 489 goto err_free_skb; 490 491 key = &tun_info->key; 492 tunnel_hlen = gre_calc_hlen(key->tun_flags); 493 494 if (skb_cow_head(skb, dev->needed_headroom)) 495 goto err_free_skb; 496 497 /* Push Tunnel header. */ 498 if (gre_handle_offloads(skb, !!(tun_info->key.tun_flags & TUNNEL_CSUM))) 499 goto err_free_skb; 500 501 flags = tun_info->key.tun_flags & 502 (TUNNEL_CSUM | TUNNEL_KEY | TUNNEL_SEQ); 503 gre_build_header(skb, tunnel_hlen, flags, proto, 504 tunnel_id_to_key32(tun_info->key.tun_id), 505 (flags & TUNNEL_SEQ) ? htonl(atomic_fetch_inc(&tunnel->o_seqno)) : 0); 506 507 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen); 508 509 return; 510 511 err_free_skb: 512 kfree_skb(skb); 513 dev->stats.tx_dropped++; 514 } 515 516 static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev) 517 { 518 struct ip_tunnel *tunnel = netdev_priv(dev); 519 struct ip_tunnel_info *tun_info; 520 const struct ip_tunnel_key *key; 521 struct erspan_metadata *md; 522 bool truncate = false; 523 __be16 proto; 524 int tunnel_hlen; 525 int version; 526 int nhoff; 527 int thoff; 528 529 tun_info = skb_tunnel_info(skb); 530 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) || 531 ip_tunnel_info_af(tun_info) != AF_INET)) 532 goto err_free_skb; 533 534 key = &tun_info->key; 535 if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT)) 536 goto err_free_skb; 537 if (tun_info->options_len < sizeof(*md)) 538 goto err_free_skb; 539 md = ip_tunnel_info_opts(tun_info); 540 541 /* ERSPAN has fixed 8 byte GRE header */ 542 version = md->version; 543 tunnel_hlen = 8 + erspan_hdr_len(version); 544 545 if (skb_cow_head(skb, dev->needed_headroom)) 546 goto err_free_skb; 547 548 if (gre_handle_offloads(skb, false)) 549 goto err_free_skb; 550 551 if (skb->len > dev->mtu + dev->hard_header_len) { 552 pskb_trim(skb, dev->mtu + dev->hard_header_len); 553 truncate = true; 554 } 555 556 nhoff = skb_network_header(skb) - skb_mac_header(skb); 557 if (skb->protocol == htons(ETH_P_IP) && 558 (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff)) 559 truncate = true; 560 561 thoff = skb_transport_header(skb) - skb_mac_header(skb); 562 if (skb->protocol == htons(ETH_P_IPV6) && 563 (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff)) 564 truncate = true; 565 566 if (version == 1) { 567 erspan_build_header(skb, ntohl(tunnel_id_to_key32(key->tun_id)), 568 ntohl(md->u.index), truncate, true); 569 proto = htons(ETH_P_ERSPAN); 570 } else if (version == 2) { 571 erspan_build_header_v2(skb, 572 ntohl(tunnel_id_to_key32(key->tun_id)), 573 md->u.md2.dir, 574 get_hwid(&md->u.md2), 575 truncate, true); 576 proto = htons(ETH_P_ERSPAN2); 577 } else { 578 goto err_free_skb; 579 } 580 581 gre_build_header(skb, 8, TUNNEL_SEQ, 582 proto, 0, htonl(atomic_fetch_inc(&tunnel->o_seqno))); 583 584 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen); 585 586 return; 587 588 err_free_skb: 589 kfree_skb(skb); 590 dev->stats.tx_dropped++; 591 } 592 593 static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb) 594 { 595 struct ip_tunnel_info *info = skb_tunnel_info(skb); 596 const struct ip_tunnel_key *key; 597 struct rtable *rt; 598 struct flowi4 fl4; 599 600 if (ip_tunnel_info_af(info) != AF_INET) 601 return -EINVAL; 602 603 key = &info->key; 604 ip_tunnel_init_flow(&fl4, IPPROTO_GRE, key->u.ipv4.dst, key->u.ipv4.src, 605 tunnel_id_to_key32(key->tun_id), 606 key->tos & ~INET_ECN_MASK, dev_net(dev), 0, 607 skb->mark, skb_get_hash(skb)); 608 rt = ip_route_output_key(dev_net(dev), &fl4); 609 if (IS_ERR(rt)) 610 return PTR_ERR(rt); 611 612 ip_rt_put(rt); 613 info->key.u.ipv4.src = fl4.saddr; 614 return 0; 615 } 616 617 static netdev_tx_t ipgre_xmit(struct sk_buff *skb, 618 struct net_device *dev) 619 { 620 struct ip_tunnel *tunnel = netdev_priv(dev); 621 const struct iphdr *tnl_params; 622 623 if (!pskb_inet_may_pull(skb)) 624 goto free_skb; 625 626 if (tunnel->collect_md) { 627 gre_fb_xmit(skb, dev, skb->protocol); 628 return NETDEV_TX_OK; 629 } 630 631 if (dev->header_ops) { 632 const int pull_len = tunnel->hlen + sizeof(struct iphdr); 633 634 if (skb_cow_head(skb, 0)) 635 goto free_skb; 636 637 tnl_params = (const struct iphdr *)skb->data; 638 639 if (pull_len > skb_transport_offset(skb)) 640 goto free_skb; 641 642 /* Pull skb since ip_tunnel_xmit() needs skb->data pointing 643 * to gre header. 644 */ 645 skb_pull(skb, pull_len); 646 skb_reset_mac_header(skb); 647 } else { 648 if (skb_cow_head(skb, dev->needed_headroom)) 649 goto free_skb; 650 651 tnl_params = &tunnel->parms.iph; 652 } 653 654 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM))) 655 goto free_skb; 656 657 __gre_xmit(skb, dev, tnl_params, skb->protocol); 658 return NETDEV_TX_OK; 659 660 free_skb: 661 kfree_skb(skb); 662 dev->stats.tx_dropped++; 663 return NETDEV_TX_OK; 664 } 665 666 static netdev_tx_t erspan_xmit(struct sk_buff *skb, 667 struct net_device *dev) 668 { 669 struct ip_tunnel *tunnel = netdev_priv(dev); 670 bool truncate = false; 671 __be16 proto; 672 673 if (!pskb_inet_may_pull(skb)) 674 goto free_skb; 675 676 if (tunnel->collect_md) { 677 erspan_fb_xmit(skb, dev); 678 return NETDEV_TX_OK; 679 } 680 681 if (gre_handle_offloads(skb, false)) 682 goto free_skb; 683 684 if (skb_cow_head(skb, dev->needed_headroom)) 685 goto free_skb; 686 687 if (skb->len > dev->mtu + dev->hard_header_len) { 688 pskb_trim(skb, dev->mtu + dev->hard_header_len); 689 truncate = true; 690 } 691 692 /* Push ERSPAN header */ 693 if (tunnel->erspan_ver == 0) { 694 proto = htons(ETH_P_ERSPAN); 695 tunnel->parms.o_flags &= ~TUNNEL_SEQ; 696 } else if (tunnel->erspan_ver == 1) { 697 erspan_build_header(skb, ntohl(tunnel->parms.o_key), 698 tunnel->index, 699 truncate, true); 700 proto = htons(ETH_P_ERSPAN); 701 } else if (tunnel->erspan_ver == 2) { 702 erspan_build_header_v2(skb, ntohl(tunnel->parms.o_key), 703 tunnel->dir, tunnel->hwid, 704 truncate, true); 705 proto = htons(ETH_P_ERSPAN2); 706 } else { 707 goto free_skb; 708 } 709 710 tunnel->parms.o_flags &= ~TUNNEL_KEY; 711 __gre_xmit(skb, dev, &tunnel->parms.iph, proto); 712 return NETDEV_TX_OK; 713 714 free_skb: 715 kfree_skb(skb); 716 dev->stats.tx_dropped++; 717 return NETDEV_TX_OK; 718 } 719 720 static netdev_tx_t gre_tap_xmit(struct sk_buff *skb, 721 struct net_device *dev) 722 { 723 struct ip_tunnel *tunnel = netdev_priv(dev); 724 725 if (!pskb_inet_may_pull(skb)) 726 goto free_skb; 727 728 if (tunnel->collect_md) { 729 gre_fb_xmit(skb, dev, htons(ETH_P_TEB)); 730 return NETDEV_TX_OK; 731 } 732 733 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM))) 734 goto free_skb; 735 736 if (skb_cow_head(skb, dev->needed_headroom)) 737 goto free_skb; 738 739 __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB)); 740 return NETDEV_TX_OK; 741 742 free_skb: 743 kfree_skb(skb); 744 dev->stats.tx_dropped++; 745 return NETDEV_TX_OK; 746 } 747 748 static void ipgre_link_update(struct net_device *dev, bool set_mtu) 749 { 750 struct ip_tunnel *tunnel = netdev_priv(dev); 751 int len; 752 753 len = tunnel->tun_hlen; 754 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags); 755 len = tunnel->tun_hlen - len; 756 tunnel->hlen = tunnel->hlen + len; 757 758 if (dev->header_ops) 759 dev->hard_header_len += len; 760 else 761 dev->needed_headroom += len; 762 763 if (set_mtu) 764 dev->mtu = max_t(int, dev->mtu - len, 68); 765 766 if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) { 767 if (!(tunnel->parms.o_flags & TUNNEL_CSUM) || 768 tunnel->encap.type == TUNNEL_ENCAP_NONE) { 769 dev->features |= NETIF_F_GSO_SOFTWARE; 770 dev->hw_features |= NETIF_F_GSO_SOFTWARE; 771 } else { 772 dev->features &= ~NETIF_F_GSO_SOFTWARE; 773 dev->hw_features &= ~NETIF_F_GSO_SOFTWARE; 774 } 775 dev->features |= NETIF_F_LLTX; 776 } else { 777 dev->hw_features &= ~NETIF_F_GSO_SOFTWARE; 778 dev->features &= ~(NETIF_F_LLTX | NETIF_F_GSO_SOFTWARE); 779 } 780 } 781 782 static int ipgre_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, 783 int cmd) 784 { 785 int err; 786 787 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) { 788 if (p->iph.version != 4 || p->iph.protocol != IPPROTO_GRE || 789 p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)) || 790 ((p->i_flags | p->o_flags) & (GRE_VERSION | GRE_ROUTING))) 791 return -EINVAL; 792 } 793 794 p->i_flags = gre_flags_to_tnl_flags(p->i_flags); 795 p->o_flags = gre_flags_to_tnl_flags(p->o_flags); 796 797 err = ip_tunnel_ctl(dev, p, cmd); 798 if (err) 799 return err; 800 801 if (cmd == SIOCCHGTUNNEL) { 802 struct ip_tunnel *t = netdev_priv(dev); 803 804 t->parms.i_flags = p->i_flags; 805 t->parms.o_flags = p->o_flags; 806 807 if (strcmp(dev->rtnl_link_ops->kind, "erspan")) 808 ipgre_link_update(dev, true); 809 } 810 811 p->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags); 812 p->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags); 813 return 0; 814 } 815 816 /* Nice toy. Unfortunately, useless in real life :-) 817 It allows to construct virtual multiprotocol broadcast "LAN" 818 over the Internet, provided multicast routing is tuned. 819 820 821 I have no idea was this bicycle invented before me, 822 so that I had to set ARPHRD_IPGRE to a random value. 823 I have an impression, that Cisco could make something similar, 824 but this feature is apparently missing in IOS<=11.2(8). 825 826 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks 827 with broadcast 224.66.66.66. If you have access to mbone, play with me :-) 828 829 ping -t 255 224.66.66.66 830 831 If nobody answers, mbone does not work. 832 833 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255 834 ip addr add 10.66.66.<somewhat>/24 dev Universe 835 ifconfig Universe up 836 ifconfig Universe add fe80::<Your_real_addr>/10 837 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96 838 ftp 10.66.66.66 839 ... 840 ftp fec0:6666:6666::193.233.7.65 841 ... 842 */ 843 static int ipgre_header(struct sk_buff *skb, struct net_device *dev, 844 unsigned short type, 845 const void *daddr, const void *saddr, unsigned int len) 846 { 847 struct ip_tunnel *t = netdev_priv(dev); 848 struct iphdr *iph; 849 struct gre_base_hdr *greh; 850 851 iph = skb_push(skb, t->hlen + sizeof(*iph)); 852 greh = (struct gre_base_hdr *)(iph+1); 853 greh->flags = gre_tnl_flags_to_gre_flags(t->parms.o_flags); 854 greh->protocol = htons(type); 855 856 memcpy(iph, &t->parms.iph, sizeof(struct iphdr)); 857 858 /* Set the source hardware address. */ 859 if (saddr) 860 memcpy(&iph->saddr, saddr, 4); 861 if (daddr) 862 memcpy(&iph->daddr, daddr, 4); 863 if (iph->daddr) 864 return t->hlen + sizeof(*iph); 865 866 return -(t->hlen + sizeof(*iph)); 867 } 868 869 static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr) 870 { 871 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb); 872 memcpy(haddr, &iph->saddr, 4); 873 return 4; 874 } 875 876 static const struct header_ops ipgre_header_ops = { 877 .create = ipgre_header, 878 .parse = ipgre_header_parse, 879 }; 880 881 #ifdef CONFIG_NET_IPGRE_BROADCAST 882 static int ipgre_open(struct net_device *dev) 883 { 884 struct ip_tunnel *t = netdev_priv(dev); 885 886 if (ipv4_is_multicast(t->parms.iph.daddr)) { 887 struct flowi4 fl4; 888 struct rtable *rt; 889 890 rt = ip_route_output_gre(t->net, &fl4, 891 t->parms.iph.daddr, 892 t->parms.iph.saddr, 893 t->parms.o_key, 894 RT_TOS(t->parms.iph.tos), 895 t->parms.link); 896 if (IS_ERR(rt)) 897 return -EADDRNOTAVAIL; 898 dev = rt->dst.dev; 899 ip_rt_put(rt); 900 if (!__in_dev_get_rtnl(dev)) 901 return -EADDRNOTAVAIL; 902 t->mlink = dev->ifindex; 903 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr); 904 } 905 return 0; 906 } 907 908 static int ipgre_close(struct net_device *dev) 909 { 910 struct ip_tunnel *t = netdev_priv(dev); 911 912 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) { 913 struct in_device *in_dev; 914 in_dev = inetdev_by_index(t->net, t->mlink); 915 if (in_dev) 916 ip_mc_dec_group(in_dev, t->parms.iph.daddr); 917 } 918 return 0; 919 } 920 #endif 921 922 static const struct net_device_ops ipgre_netdev_ops = { 923 .ndo_init = ipgre_tunnel_init, 924 .ndo_uninit = ip_tunnel_uninit, 925 #ifdef CONFIG_NET_IPGRE_BROADCAST 926 .ndo_open = ipgre_open, 927 .ndo_stop = ipgre_close, 928 #endif 929 .ndo_start_xmit = ipgre_xmit, 930 .ndo_siocdevprivate = ip_tunnel_siocdevprivate, 931 .ndo_change_mtu = ip_tunnel_change_mtu, 932 .ndo_get_stats64 = dev_get_tstats64, 933 .ndo_get_iflink = ip_tunnel_get_iflink, 934 .ndo_tunnel_ctl = ipgre_tunnel_ctl, 935 }; 936 937 #define GRE_FEATURES (NETIF_F_SG | \ 938 NETIF_F_FRAGLIST | \ 939 NETIF_F_HIGHDMA | \ 940 NETIF_F_HW_CSUM) 941 942 static void ipgre_tunnel_setup(struct net_device *dev) 943 { 944 dev->netdev_ops = &ipgre_netdev_ops; 945 dev->type = ARPHRD_IPGRE; 946 ip_tunnel_setup(dev, ipgre_net_id); 947 } 948 949 static void __gre_tunnel_init(struct net_device *dev) 950 { 951 struct ip_tunnel *tunnel; 952 953 tunnel = netdev_priv(dev); 954 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags); 955 tunnel->parms.iph.protocol = IPPROTO_GRE; 956 957 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen; 958 dev->needed_headroom = tunnel->hlen + sizeof(tunnel->parms.iph); 959 960 dev->features |= GRE_FEATURES; 961 dev->hw_features |= GRE_FEATURES; 962 963 if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) { 964 /* TCP offload with GRE SEQ is not supported, nor 965 * can we support 2 levels of outer headers requiring 966 * an update. 967 */ 968 if (!(tunnel->parms.o_flags & TUNNEL_CSUM) || 969 (tunnel->encap.type == TUNNEL_ENCAP_NONE)) { 970 dev->features |= NETIF_F_GSO_SOFTWARE; 971 dev->hw_features |= NETIF_F_GSO_SOFTWARE; 972 } 973 974 /* Can use a lockless transmit, unless we generate 975 * output sequences 976 */ 977 dev->features |= NETIF_F_LLTX; 978 } 979 } 980 981 static int ipgre_tunnel_init(struct net_device *dev) 982 { 983 struct ip_tunnel *tunnel = netdev_priv(dev); 984 struct iphdr *iph = &tunnel->parms.iph; 985 986 __gre_tunnel_init(dev); 987 988 __dev_addr_set(dev, &iph->saddr, 4); 989 memcpy(dev->broadcast, &iph->daddr, 4); 990 991 dev->flags = IFF_NOARP; 992 netif_keep_dst(dev); 993 dev->addr_len = 4; 994 995 if (iph->daddr && !tunnel->collect_md) { 996 #ifdef CONFIG_NET_IPGRE_BROADCAST 997 if (ipv4_is_multicast(iph->daddr)) { 998 if (!iph->saddr) 999 return -EINVAL; 1000 dev->flags = IFF_BROADCAST; 1001 dev->header_ops = &ipgre_header_ops; 1002 dev->hard_header_len = tunnel->hlen + sizeof(*iph); 1003 dev->needed_headroom = 0; 1004 } 1005 #endif 1006 } else if (!tunnel->collect_md) { 1007 dev->header_ops = &ipgre_header_ops; 1008 dev->hard_header_len = tunnel->hlen + sizeof(*iph); 1009 dev->needed_headroom = 0; 1010 } 1011 1012 return ip_tunnel_init(dev); 1013 } 1014 1015 static const struct gre_protocol ipgre_protocol = { 1016 .handler = gre_rcv, 1017 .err_handler = gre_err, 1018 }; 1019 1020 static int __net_init ipgre_init_net(struct net *net) 1021 { 1022 return ip_tunnel_init_net(net, ipgre_net_id, &ipgre_link_ops, NULL); 1023 } 1024 1025 static void __net_exit ipgre_exit_batch_net(struct list_head *list_net) 1026 { 1027 ip_tunnel_delete_nets(list_net, ipgre_net_id, &ipgre_link_ops); 1028 } 1029 1030 static struct pernet_operations ipgre_net_ops = { 1031 .init = ipgre_init_net, 1032 .exit_batch = ipgre_exit_batch_net, 1033 .id = &ipgre_net_id, 1034 .size = sizeof(struct ip_tunnel_net), 1035 }; 1036 1037 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[], 1038 struct netlink_ext_ack *extack) 1039 { 1040 __be16 flags; 1041 1042 if (!data) 1043 return 0; 1044 1045 flags = 0; 1046 if (data[IFLA_GRE_IFLAGS]) 1047 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); 1048 if (data[IFLA_GRE_OFLAGS]) 1049 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); 1050 if (flags & (GRE_VERSION|GRE_ROUTING)) 1051 return -EINVAL; 1052 1053 if (data[IFLA_GRE_COLLECT_METADATA] && 1054 data[IFLA_GRE_ENCAP_TYPE] && 1055 nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]) != TUNNEL_ENCAP_NONE) 1056 return -EINVAL; 1057 1058 return 0; 1059 } 1060 1061 static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[], 1062 struct netlink_ext_ack *extack) 1063 { 1064 __be32 daddr; 1065 1066 if (tb[IFLA_ADDRESS]) { 1067 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) 1068 return -EINVAL; 1069 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) 1070 return -EADDRNOTAVAIL; 1071 } 1072 1073 if (!data) 1074 goto out; 1075 1076 if (data[IFLA_GRE_REMOTE]) { 1077 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4); 1078 if (!daddr) 1079 return -EINVAL; 1080 } 1081 1082 out: 1083 return ipgre_tunnel_validate(tb, data, extack); 1084 } 1085 1086 static int erspan_validate(struct nlattr *tb[], struct nlattr *data[], 1087 struct netlink_ext_ack *extack) 1088 { 1089 __be16 flags = 0; 1090 int ret; 1091 1092 if (!data) 1093 return 0; 1094 1095 ret = ipgre_tap_validate(tb, data, extack); 1096 if (ret) 1097 return ret; 1098 1099 if (data[IFLA_GRE_ERSPAN_VER] && 1100 nla_get_u8(data[IFLA_GRE_ERSPAN_VER]) == 0) 1101 return 0; 1102 1103 /* ERSPAN type II/III should only have GRE sequence and key flag */ 1104 if (data[IFLA_GRE_OFLAGS]) 1105 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); 1106 if (data[IFLA_GRE_IFLAGS]) 1107 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); 1108 if (!data[IFLA_GRE_COLLECT_METADATA] && 1109 flags != (GRE_SEQ | GRE_KEY)) 1110 return -EINVAL; 1111 1112 /* ERSPAN Session ID only has 10-bit. Since we reuse 1113 * 32-bit key field as ID, check it's range. 1114 */ 1115 if (data[IFLA_GRE_IKEY] && 1116 (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK)) 1117 return -EINVAL; 1118 1119 if (data[IFLA_GRE_OKEY] && 1120 (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK)) 1121 return -EINVAL; 1122 1123 return 0; 1124 } 1125 1126 static int ipgre_netlink_parms(struct net_device *dev, 1127 struct nlattr *data[], 1128 struct nlattr *tb[], 1129 struct ip_tunnel_parm *parms, 1130 __u32 *fwmark) 1131 { 1132 struct ip_tunnel *t = netdev_priv(dev); 1133 1134 memset(parms, 0, sizeof(*parms)); 1135 1136 parms->iph.protocol = IPPROTO_GRE; 1137 1138 if (!data) 1139 return 0; 1140 1141 if (data[IFLA_GRE_LINK]) 1142 parms->link = nla_get_u32(data[IFLA_GRE_LINK]); 1143 1144 if (data[IFLA_GRE_IFLAGS]) 1145 parms->i_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_IFLAGS])); 1146 1147 if (data[IFLA_GRE_OFLAGS]) 1148 parms->o_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_OFLAGS])); 1149 1150 if (data[IFLA_GRE_IKEY]) 1151 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]); 1152 1153 if (data[IFLA_GRE_OKEY]) 1154 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]); 1155 1156 if (data[IFLA_GRE_LOCAL]) 1157 parms->iph.saddr = nla_get_in_addr(data[IFLA_GRE_LOCAL]); 1158 1159 if (data[IFLA_GRE_REMOTE]) 1160 parms->iph.daddr = nla_get_in_addr(data[IFLA_GRE_REMOTE]); 1161 1162 if (data[IFLA_GRE_TTL]) 1163 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]); 1164 1165 if (data[IFLA_GRE_TOS]) 1166 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]); 1167 1168 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC])) { 1169 if (t->ignore_df) 1170 return -EINVAL; 1171 parms->iph.frag_off = htons(IP_DF); 1172 } 1173 1174 if (data[IFLA_GRE_COLLECT_METADATA]) { 1175 t->collect_md = true; 1176 if (dev->type == ARPHRD_IPGRE) 1177 dev->type = ARPHRD_NONE; 1178 } 1179 1180 if (data[IFLA_GRE_IGNORE_DF]) { 1181 if (nla_get_u8(data[IFLA_GRE_IGNORE_DF]) 1182 && (parms->iph.frag_off & htons(IP_DF))) 1183 return -EINVAL; 1184 t->ignore_df = !!nla_get_u8(data[IFLA_GRE_IGNORE_DF]); 1185 } 1186 1187 if (data[IFLA_GRE_FWMARK]) 1188 *fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]); 1189 1190 return 0; 1191 } 1192 1193 static int erspan_netlink_parms(struct net_device *dev, 1194 struct nlattr *data[], 1195 struct nlattr *tb[], 1196 struct ip_tunnel_parm *parms, 1197 __u32 *fwmark) 1198 { 1199 struct ip_tunnel *t = netdev_priv(dev); 1200 int err; 1201 1202 err = ipgre_netlink_parms(dev, data, tb, parms, fwmark); 1203 if (err) 1204 return err; 1205 if (!data) 1206 return 0; 1207 1208 if (data[IFLA_GRE_ERSPAN_VER]) { 1209 t->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]); 1210 1211 if (t->erspan_ver > 2) 1212 return -EINVAL; 1213 } 1214 1215 if (t->erspan_ver == 1) { 1216 if (data[IFLA_GRE_ERSPAN_INDEX]) { 1217 t->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]); 1218 if (t->index & ~INDEX_MASK) 1219 return -EINVAL; 1220 } 1221 } else if (t->erspan_ver == 2) { 1222 if (data[IFLA_GRE_ERSPAN_DIR]) { 1223 t->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]); 1224 if (t->dir & ~(DIR_MASK >> DIR_OFFSET)) 1225 return -EINVAL; 1226 } 1227 if (data[IFLA_GRE_ERSPAN_HWID]) { 1228 t->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]); 1229 if (t->hwid & ~(HWID_MASK >> HWID_OFFSET)) 1230 return -EINVAL; 1231 } 1232 } 1233 1234 return 0; 1235 } 1236 1237 /* This function returns true when ENCAP attributes are present in the nl msg */ 1238 static bool ipgre_netlink_encap_parms(struct nlattr *data[], 1239 struct ip_tunnel_encap *ipencap) 1240 { 1241 bool ret = false; 1242 1243 memset(ipencap, 0, sizeof(*ipencap)); 1244 1245 if (!data) 1246 return ret; 1247 1248 if (data[IFLA_GRE_ENCAP_TYPE]) { 1249 ret = true; 1250 ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]); 1251 } 1252 1253 if (data[IFLA_GRE_ENCAP_FLAGS]) { 1254 ret = true; 1255 ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]); 1256 } 1257 1258 if (data[IFLA_GRE_ENCAP_SPORT]) { 1259 ret = true; 1260 ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]); 1261 } 1262 1263 if (data[IFLA_GRE_ENCAP_DPORT]) { 1264 ret = true; 1265 ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]); 1266 } 1267 1268 return ret; 1269 } 1270 1271 static int gre_tap_init(struct net_device *dev) 1272 { 1273 __gre_tunnel_init(dev); 1274 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1275 netif_keep_dst(dev); 1276 1277 return ip_tunnel_init(dev); 1278 } 1279 1280 static const struct net_device_ops gre_tap_netdev_ops = { 1281 .ndo_init = gre_tap_init, 1282 .ndo_uninit = ip_tunnel_uninit, 1283 .ndo_start_xmit = gre_tap_xmit, 1284 .ndo_set_mac_address = eth_mac_addr, 1285 .ndo_validate_addr = eth_validate_addr, 1286 .ndo_change_mtu = ip_tunnel_change_mtu, 1287 .ndo_get_stats64 = dev_get_tstats64, 1288 .ndo_get_iflink = ip_tunnel_get_iflink, 1289 .ndo_fill_metadata_dst = gre_fill_metadata_dst, 1290 }; 1291 1292 static int erspan_tunnel_init(struct net_device *dev) 1293 { 1294 struct ip_tunnel *tunnel = netdev_priv(dev); 1295 1296 if (tunnel->erspan_ver == 0) 1297 tunnel->tun_hlen = 4; /* 4-byte GRE hdr. */ 1298 else 1299 tunnel->tun_hlen = 8; /* 8-byte GRE hdr. */ 1300 1301 tunnel->parms.iph.protocol = IPPROTO_GRE; 1302 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen + 1303 erspan_hdr_len(tunnel->erspan_ver); 1304 1305 dev->features |= GRE_FEATURES; 1306 dev->hw_features |= GRE_FEATURES; 1307 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1308 netif_keep_dst(dev); 1309 1310 return ip_tunnel_init(dev); 1311 } 1312 1313 static const struct net_device_ops erspan_netdev_ops = { 1314 .ndo_init = erspan_tunnel_init, 1315 .ndo_uninit = ip_tunnel_uninit, 1316 .ndo_start_xmit = erspan_xmit, 1317 .ndo_set_mac_address = eth_mac_addr, 1318 .ndo_validate_addr = eth_validate_addr, 1319 .ndo_change_mtu = ip_tunnel_change_mtu, 1320 .ndo_get_stats64 = dev_get_tstats64, 1321 .ndo_get_iflink = ip_tunnel_get_iflink, 1322 .ndo_fill_metadata_dst = gre_fill_metadata_dst, 1323 }; 1324 1325 static void ipgre_tap_setup(struct net_device *dev) 1326 { 1327 ether_setup(dev); 1328 dev->max_mtu = 0; 1329 dev->netdev_ops = &gre_tap_netdev_ops; 1330 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 1331 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1332 ip_tunnel_setup(dev, gre_tap_net_id); 1333 } 1334 1335 static int 1336 ipgre_newlink_encap_setup(struct net_device *dev, struct nlattr *data[]) 1337 { 1338 struct ip_tunnel_encap ipencap; 1339 1340 if (ipgre_netlink_encap_parms(data, &ipencap)) { 1341 struct ip_tunnel *t = netdev_priv(dev); 1342 int err = ip_tunnel_encap_setup(t, &ipencap); 1343 1344 if (err < 0) 1345 return err; 1346 } 1347 1348 return 0; 1349 } 1350 1351 static int ipgre_newlink(struct net *src_net, struct net_device *dev, 1352 struct nlattr *tb[], struct nlattr *data[], 1353 struct netlink_ext_ack *extack) 1354 { 1355 struct ip_tunnel_parm p; 1356 __u32 fwmark = 0; 1357 int err; 1358 1359 err = ipgre_newlink_encap_setup(dev, data); 1360 if (err) 1361 return err; 1362 1363 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark); 1364 if (err < 0) 1365 return err; 1366 return ip_tunnel_newlink(dev, tb, &p, fwmark); 1367 } 1368 1369 static int erspan_newlink(struct net *src_net, struct net_device *dev, 1370 struct nlattr *tb[], struct nlattr *data[], 1371 struct netlink_ext_ack *extack) 1372 { 1373 struct ip_tunnel_parm p; 1374 __u32 fwmark = 0; 1375 int err; 1376 1377 err = ipgre_newlink_encap_setup(dev, data); 1378 if (err) 1379 return err; 1380 1381 err = erspan_netlink_parms(dev, data, tb, &p, &fwmark); 1382 if (err) 1383 return err; 1384 return ip_tunnel_newlink(dev, tb, &p, fwmark); 1385 } 1386 1387 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[], 1388 struct nlattr *data[], 1389 struct netlink_ext_ack *extack) 1390 { 1391 struct ip_tunnel *t = netdev_priv(dev); 1392 __u32 fwmark = t->fwmark; 1393 struct ip_tunnel_parm p; 1394 int err; 1395 1396 err = ipgre_newlink_encap_setup(dev, data); 1397 if (err) 1398 return err; 1399 1400 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark); 1401 if (err < 0) 1402 return err; 1403 1404 err = ip_tunnel_changelink(dev, tb, &p, fwmark); 1405 if (err < 0) 1406 return err; 1407 1408 t->parms.i_flags = p.i_flags; 1409 t->parms.o_flags = p.o_flags; 1410 1411 ipgre_link_update(dev, !tb[IFLA_MTU]); 1412 1413 return 0; 1414 } 1415 1416 static int erspan_changelink(struct net_device *dev, struct nlattr *tb[], 1417 struct nlattr *data[], 1418 struct netlink_ext_ack *extack) 1419 { 1420 struct ip_tunnel *t = netdev_priv(dev); 1421 __u32 fwmark = t->fwmark; 1422 struct ip_tunnel_parm p; 1423 int err; 1424 1425 err = ipgre_newlink_encap_setup(dev, data); 1426 if (err) 1427 return err; 1428 1429 err = erspan_netlink_parms(dev, data, tb, &p, &fwmark); 1430 if (err < 0) 1431 return err; 1432 1433 err = ip_tunnel_changelink(dev, tb, &p, fwmark); 1434 if (err < 0) 1435 return err; 1436 1437 t->parms.i_flags = p.i_flags; 1438 t->parms.o_flags = p.o_flags; 1439 1440 return 0; 1441 } 1442 1443 static size_t ipgre_get_size(const struct net_device *dev) 1444 { 1445 return 1446 /* IFLA_GRE_LINK */ 1447 nla_total_size(4) + 1448 /* IFLA_GRE_IFLAGS */ 1449 nla_total_size(2) + 1450 /* IFLA_GRE_OFLAGS */ 1451 nla_total_size(2) + 1452 /* IFLA_GRE_IKEY */ 1453 nla_total_size(4) + 1454 /* IFLA_GRE_OKEY */ 1455 nla_total_size(4) + 1456 /* IFLA_GRE_LOCAL */ 1457 nla_total_size(4) + 1458 /* IFLA_GRE_REMOTE */ 1459 nla_total_size(4) + 1460 /* IFLA_GRE_TTL */ 1461 nla_total_size(1) + 1462 /* IFLA_GRE_TOS */ 1463 nla_total_size(1) + 1464 /* IFLA_GRE_PMTUDISC */ 1465 nla_total_size(1) + 1466 /* IFLA_GRE_ENCAP_TYPE */ 1467 nla_total_size(2) + 1468 /* IFLA_GRE_ENCAP_FLAGS */ 1469 nla_total_size(2) + 1470 /* IFLA_GRE_ENCAP_SPORT */ 1471 nla_total_size(2) + 1472 /* IFLA_GRE_ENCAP_DPORT */ 1473 nla_total_size(2) + 1474 /* IFLA_GRE_COLLECT_METADATA */ 1475 nla_total_size(0) + 1476 /* IFLA_GRE_IGNORE_DF */ 1477 nla_total_size(1) + 1478 /* IFLA_GRE_FWMARK */ 1479 nla_total_size(4) + 1480 /* IFLA_GRE_ERSPAN_INDEX */ 1481 nla_total_size(4) + 1482 /* IFLA_GRE_ERSPAN_VER */ 1483 nla_total_size(1) + 1484 /* IFLA_GRE_ERSPAN_DIR */ 1485 nla_total_size(1) + 1486 /* IFLA_GRE_ERSPAN_HWID */ 1487 nla_total_size(2) + 1488 0; 1489 } 1490 1491 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev) 1492 { 1493 struct ip_tunnel *t = netdev_priv(dev); 1494 struct ip_tunnel_parm *p = &t->parms; 1495 __be16 o_flags = p->o_flags; 1496 1497 if (t->erspan_ver <= 2) { 1498 if (t->erspan_ver != 0 && !t->collect_md) 1499 o_flags |= TUNNEL_KEY; 1500 1501 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, t->erspan_ver)) 1502 goto nla_put_failure; 1503 1504 if (t->erspan_ver == 1) { 1505 if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, t->index)) 1506 goto nla_put_failure; 1507 } else if (t->erspan_ver == 2) { 1508 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, t->dir)) 1509 goto nla_put_failure; 1510 if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, t->hwid)) 1511 goto nla_put_failure; 1512 } 1513 } 1514 1515 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) || 1516 nla_put_be16(skb, IFLA_GRE_IFLAGS, 1517 gre_tnl_flags_to_gre_flags(p->i_flags)) || 1518 nla_put_be16(skb, IFLA_GRE_OFLAGS, 1519 gre_tnl_flags_to_gre_flags(o_flags)) || 1520 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) || 1521 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) || 1522 nla_put_in_addr(skb, IFLA_GRE_LOCAL, p->iph.saddr) || 1523 nla_put_in_addr(skb, IFLA_GRE_REMOTE, p->iph.daddr) || 1524 nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) || 1525 nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) || 1526 nla_put_u8(skb, IFLA_GRE_PMTUDISC, 1527 !!(p->iph.frag_off & htons(IP_DF))) || 1528 nla_put_u32(skb, IFLA_GRE_FWMARK, t->fwmark)) 1529 goto nla_put_failure; 1530 1531 if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE, 1532 t->encap.type) || 1533 nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT, 1534 t->encap.sport) || 1535 nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT, 1536 t->encap.dport) || 1537 nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS, 1538 t->encap.flags)) 1539 goto nla_put_failure; 1540 1541 if (nla_put_u8(skb, IFLA_GRE_IGNORE_DF, t->ignore_df)) 1542 goto nla_put_failure; 1543 1544 if (t->collect_md) { 1545 if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA)) 1546 goto nla_put_failure; 1547 } 1548 1549 return 0; 1550 1551 nla_put_failure: 1552 return -EMSGSIZE; 1553 } 1554 1555 static void erspan_setup(struct net_device *dev) 1556 { 1557 struct ip_tunnel *t = netdev_priv(dev); 1558 1559 ether_setup(dev); 1560 dev->max_mtu = 0; 1561 dev->netdev_ops = &erspan_netdev_ops; 1562 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 1563 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1564 ip_tunnel_setup(dev, erspan_net_id); 1565 t->erspan_ver = 1; 1566 } 1567 1568 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = { 1569 [IFLA_GRE_LINK] = { .type = NLA_U32 }, 1570 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 }, 1571 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 }, 1572 [IFLA_GRE_IKEY] = { .type = NLA_U32 }, 1573 [IFLA_GRE_OKEY] = { .type = NLA_U32 }, 1574 [IFLA_GRE_LOCAL] = { .len = sizeof_field(struct iphdr, saddr) }, 1575 [IFLA_GRE_REMOTE] = { .len = sizeof_field(struct iphdr, daddr) }, 1576 [IFLA_GRE_TTL] = { .type = NLA_U8 }, 1577 [IFLA_GRE_TOS] = { .type = NLA_U8 }, 1578 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 }, 1579 [IFLA_GRE_ENCAP_TYPE] = { .type = NLA_U16 }, 1580 [IFLA_GRE_ENCAP_FLAGS] = { .type = NLA_U16 }, 1581 [IFLA_GRE_ENCAP_SPORT] = { .type = NLA_U16 }, 1582 [IFLA_GRE_ENCAP_DPORT] = { .type = NLA_U16 }, 1583 [IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG }, 1584 [IFLA_GRE_IGNORE_DF] = { .type = NLA_U8 }, 1585 [IFLA_GRE_FWMARK] = { .type = NLA_U32 }, 1586 [IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 }, 1587 [IFLA_GRE_ERSPAN_VER] = { .type = NLA_U8 }, 1588 [IFLA_GRE_ERSPAN_DIR] = { .type = NLA_U8 }, 1589 [IFLA_GRE_ERSPAN_HWID] = { .type = NLA_U16 }, 1590 }; 1591 1592 static struct rtnl_link_ops ipgre_link_ops __read_mostly = { 1593 .kind = "gre", 1594 .maxtype = IFLA_GRE_MAX, 1595 .policy = ipgre_policy, 1596 .priv_size = sizeof(struct ip_tunnel), 1597 .setup = ipgre_tunnel_setup, 1598 .validate = ipgre_tunnel_validate, 1599 .newlink = ipgre_newlink, 1600 .changelink = ipgre_changelink, 1601 .dellink = ip_tunnel_dellink, 1602 .get_size = ipgre_get_size, 1603 .fill_info = ipgre_fill_info, 1604 .get_link_net = ip_tunnel_get_link_net, 1605 }; 1606 1607 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = { 1608 .kind = "gretap", 1609 .maxtype = IFLA_GRE_MAX, 1610 .policy = ipgre_policy, 1611 .priv_size = sizeof(struct ip_tunnel), 1612 .setup = ipgre_tap_setup, 1613 .validate = ipgre_tap_validate, 1614 .newlink = ipgre_newlink, 1615 .changelink = ipgre_changelink, 1616 .dellink = ip_tunnel_dellink, 1617 .get_size = ipgre_get_size, 1618 .fill_info = ipgre_fill_info, 1619 .get_link_net = ip_tunnel_get_link_net, 1620 }; 1621 1622 static struct rtnl_link_ops erspan_link_ops __read_mostly = { 1623 .kind = "erspan", 1624 .maxtype = IFLA_GRE_MAX, 1625 .policy = ipgre_policy, 1626 .priv_size = sizeof(struct ip_tunnel), 1627 .setup = erspan_setup, 1628 .validate = erspan_validate, 1629 .newlink = erspan_newlink, 1630 .changelink = erspan_changelink, 1631 .dellink = ip_tunnel_dellink, 1632 .get_size = ipgre_get_size, 1633 .fill_info = ipgre_fill_info, 1634 .get_link_net = ip_tunnel_get_link_net, 1635 }; 1636 1637 struct net_device *gretap_fb_dev_create(struct net *net, const char *name, 1638 u8 name_assign_type) 1639 { 1640 struct nlattr *tb[IFLA_MAX + 1]; 1641 struct net_device *dev; 1642 LIST_HEAD(list_kill); 1643 struct ip_tunnel *t; 1644 int err; 1645 1646 memset(&tb, 0, sizeof(tb)); 1647 1648 dev = rtnl_create_link(net, name, name_assign_type, 1649 &ipgre_tap_ops, tb, NULL); 1650 if (IS_ERR(dev)) 1651 return dev; 1652 1653 /* Configure flow based GRE device. */ 1654 t = netdev_priv(dev); 1655 t->collect_md = true; 1656 1657 err = ipgre_newlink(net, dev, tb, NULL, NULL); 1658 if (err < 0) { 1659 free_netdev(dev); 1660 return ERR_PTR(err); 1661 } 1662 1663 /* openvswitch users expect packet sizes to be unrestricted, 1664 * so set the largest MTU we can. 1665 */ 1666 err = __ip_tunnel_change_mtu(dev, IP_MAX_MTU, false); 1667 if (err) 1668 goto out; 1669 1670 err = rtnl_configure_link(dev, NULL); 1671 if (err < 0) 1672 goto out; 1673 1674 return dev; 1675 out: 1676 ip_tunnel_dellink(dev, &list_kill); 1677 unregister_netdevice_many(&list_kill); 1678 return ERR_PTR(err); 1679 } 1680 EXPORT_SYMBOL_GPL(gretap_fb_dev_create); 1681 1682 static int __net_init ipgre_tap_init_net(struct net *net) 1683 { 1684 return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, "gretap0"); 1685 } 1686 1687 static void __net_exit ipgre_tap_exit_batch_net(struct list_head *list_net) 1688 { 1689 ip_tunnel_delete_nets(list_net, gre_tap_net_id, &ipgre_tap_ops); 1690 } 1691 1692 static struct pernet_operations ipgre_tap_net_ops = { 1693 .init = ipgre_tap_init_net, 1694 .exit_batch = ipgre_tap_exit_batch_net, 1695 .id = &gre_tap_net_id, 1696 .size = sizeof(struct ip_tunnel_net), 1697 }; 1698 1699 static int __net_init erspan_init_net(struct net *net) 1700 { 1701 return ip_tunnel_init_net(net, erspan_net_id, 1702 &erspan_link_ops, "erspan0"); 1703 } 1704 1705 static void __net_exit erspan_exit_batch_net(struct list_head *net_list) 1706 { 1707 ip_tunnel_delete_nets(net_list, erspan_net_id, &erspan_link_ops); 1708 } 1709 1710 static struct pernet_operations erspan_net_ops = { 1711 .init = erspan_init_net, 1712 .exit_batch = erspan_exit_batch_net, 1713 .id = &erspan_net_id, 1714 .size = sizeof(struct ip_tunnel_net), 1715 }; 1716 1717 static int __init ipgre_init(void) 1718 { 1719 int err; 1720 1721 pr_info("GRE over IPv4 tunneling driver\n"); 1722 1723 err = register_pernet_device(&ipgre_net_ops); 1724 if (err < 0) 1725 return err; 1726 1727 err = register_pernet_device(&ipgre_tap_net_ops); 1728 if (err < 0) 1729 goto pnet_tap_failed; 1730 1731 err = register_pernet_device(&erspan_net_ops); 1732 if (err < 0) 1733 goto pnet_erspan_failed; 1734 1735 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO); 1736 if (err < 0) { 1737 pr_info("%s: can't add protocol\n", __func__); 1738 goto add_proto_failed; 1739 } 1740 1741 err = rtnl_link_register(&ipgre_link_ops); 1742 if (err < 0) 1743 goto rtnl_link_failed; 1744 1745 err = rtnl_link_register(&ipgre_tap_ops); 1746 if (err < 0) 1747 goto tap_ops_failed; 1748 1749 err = rtnl_link_register(&erspan_link_ops); 1750 if (err < 0) 1751 goto erspan_link_failed; 1752 1753 return 0; 1754 1755 erspan_link_failed: 1756 rtnl_link_unregister(&ipgre_tap_ops); 1757 tap_ops_failed: 1758 rtnl_link_unregister(&ipgre_link_ops); 1759 rtnl_link_failed: 1760 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); 1761 add_proto_failed: 1762 unregister_pernet_device(&erspan_net_ops); 1763 pnet_erspan_failed: 1764 unregister_pernet_device(&ipgre_tap_net_ops); 1765 pnet_tap_failed: 1766 unregister_pernet_device(&ipgre_net_ops); 1767 return err; 1768 } 1769 1770 static void __exit ipgre_fini(void) 1771 { 1772 rtnl_link_unregister(&ipgre_tap_ops); 1773 rtnl_link_unregister(&ipgre_link_ops); 1774 rtnl_link_unregister(&erspan_link_ops); 1775 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); 1776 unregister_pernet_device(&ipgre_tap_net_ops); 1777 unregister_pernet_device(&ipgre_net_ops); 1778 unregister_pernet_device(&erspan_net_ops); 1779 } 1780 1781 module_init(ipgre_init); 1782 module_exit(ipgre_fini); 1783 MODULE_LICENSE("GPL"); 1784 MODULE_ALIAS_RTNL_LINK("gre"); 1785 MODULE_ALIAS_RTNL_LINK("gretap"); 1786 MODULE_ALIAS_RTNL_LINK("erspan"); 1787 MODULE_ALIAS_NETDEV("gre0"); 1788 MODULE_ALIAS_NETDEV("gretap0"); 1789 MODULE_ALIAS_NETDEV("erspan0"); 1790