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 int ipgre_tunnel_init(struct net_device *dev); 111 static void erspan_build_header(struct sk_buff *skb, 112 u32 id, u32 index, 113 bool truncate, bool is_ipv4); 114 115 static unsigned int ipgre_net_id __read_mostly; 116 static unsigned int gre_tap_net_id __read_mostly; 117 static unsigned int erspan_net_id __read_mostly; 118 119 static int ipgre_err(struct sk_buff *skb, u32 info, 120 const struct tnl_ptk_info *tpi) 121 { 122 123 /* All the routers (except for Linux) return only 124 8 bytes of packet payload. It means, that precise relaying of 125 ICMP in the real Internet is absolutely infeasible. 126 127 Moreover, Cisco "wise men" put GRE key to the third word 128 in GRE header. It makes impossible maintaining even soft 129 state for keyed GRE tunnels with enabled checksum. Tell 130 them "thank you". 131 132 Well, I wonder, rfc1812 was written by Cisco employee, 133 what the hell these idiots break standards established 134 by themselves??? 135 */ 136 struct net *net = dev_net(skb->dev); 137 struct ip_tunnel_net *itn; 138 const struct iphdr *iph; 139 const int type = icmp_hdr(skb)->type; 140 const int code = icmp_hdr(skb)->code; 141 unsigned int data_len = 0; 142 struct ip_tunnel *t; 143 144 if (tpi->proto == htons(ETH_P_TEB)) 145 itn = net_generic(net, gre_tap_net_id); 146 else if (tpi->proto == htons(ETH_P_ERSPAN) || 147 tpi->proto == htons(ETH_P_ERSPAN2)) 148 itn = net_generic(net, erspan_net_id); 149 else 150 itn = net_generic(net, ipgre_net_id); 151 152 iph = (const struct iphdr *)(icmp_hdr(skb) + 1); 153 t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags, 154 iph->daddr, iph->saddr, tpi->key); 155 156 if (!t) 157 return -ENOENT; 158 159 switch (type) { 160 default: 161 case ICMP_PARAMETERPROB: 162 return 0; 163 164 case ICMP_DEST_UNREACH: 165 switch (code) { 166 case ICMP_SR_FAILED: 167 case ICMP_PORT_UNREACH: 168 /* Impossible event. */ 169 return 0; 170 default: 171 /* All others are translated to HOST_UNREACH. 172 rfc2003 contains "deep thoughts" about NET_UNREACH, 173 I believe they are just ether pollution. --ANK 174 */ 175 break; 176 } 177 break; 178 179 case ICMP_TIME_EXCEEDED: 180 if (code != ICMP_EXC_TTL) 181 return 0; 182 data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */ 183 break; 184 185 case ICMP_REDIRECT: 186 break; 187 } 188 189 #if IS_ENABLED(CONFIG_IPV6) 190 if (tpi->proto == htons(ETH_P_IPV6) && 191 !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4 + tpi->hdr_len, 192 type, data_len)) 193 return 0; 194 #endif 195 196 if (t->parms.iph.daddr == 0 || 197 ipv4_is_multicast(t->parms.iph.daddr)) 198 return 0; 199 200 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 201 return 0; 202 203 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) 204 t->err_count++; 205 else 206 t->err_count = 1; 207 t->err_time = jiffies; 208 209 return 0; 210 } 211 212 static void gre_err(struct sk_buff *skb, u32 info) 213 { 214 /* All the routers (except for Linux) return only 215 * 8 bytes of packet payload. It means, that precise relaying of 216 * ICMP in the real Internet is absolutely infeasible. 217 * 218 * Moreover, Cisco "wise men" put GRE key to the third word 219 * in GRE header. It makes impossible maintaining even soft 220 * state for keyed 221 * GRE tunnels with enabled checksum. Tell them "thank you". 222 * 223 * Well, I wonder, rfc1812 was written by Cisco employee, 224 * what the hell these idiots break standards established 225 * by themselves??? 226 */ 227 228 const struct iphdr *iph = (struct iphdr *)skb->data; 229 const int type = icmp_hdr(skb)->type; 230 const int code = icmp_hdr(skb)->code; 231 struct tnl_ptk_info tpi; 232 233 if (gre_parse_header(skb, &tpi, NULL, htons(ETH_P_IP), 234 iph->ihl * 4) < 0) 235 return; 236 237 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { 238 ipv4_update_pmtu(skb, dev_net(skb->dev), info, 239 skb->dev->ifindex, IPPROTO_GRE); 240 return; 241 } 242 if (type == ICMP_REDIRECT) { 243 ipv4_redirect(skb, dev_net(skb->dev), skb->dev->ifindex, 244 IPPROTO_GRE); 245 return; 246 } 247 248 ipgre_err(skb, info, &tpi); 249 } 250 251 static bool is_erspan_type1(int gre_hdr_len) 252 { 253 /* Both ERSPAN type I (version 0) and type II (version 1) use 254 * protocol 0x88BE, but the type I has only 4-byte GRE header, 255 * while type II has 8-byte. 256 */ 257 return gre_hdr_len == 4; 258 } 259 260 static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi, 261 int gre_hdr_len) 262 { 263 struct net *net = dev_net(skb->dev); 264 struct metadata_dst *tun_dst = NULL; 265 struct erspan_base_hdr *ershdr; 266 struct ip_tunnel_net *itn; 267 struct ip_tunnel *tunnel; 268 const struct iphdr *iph; 269 struct erspan_md2 *md2; 270 int ver; 271 int len; 272 273 itn = net_generic(net, erspan_net_id); 274 iph = ip_hdr(skb); 275 if (is_erspan_type1(gre_hdr_len)) { 276 ver = 0; 277 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, 278 tpi->flags | TUNNEL_NO_KEY, 279 iph->saddr, iph->daddr, 0); 280 } else { 281 ershdr = (struct erspan_base_hdr *)(skb->data + gre_hdr_len); 282 ver = ershdr->ver; 283 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, 284 tpi->flags | TUNNEL_KEY, 285 iph->saddr, iph->daddr, tpi->key); 286 } 287 288 if (tunnel) { 289 if (is_erspan_type1(gre_hdr_len)) 290 len = gre_hdr_len; 291 else 292 len = gre_hdr_len + erspan_hdr_len(ver); 293 294 if (unlikely(!pskb_may_pull(skb, len))) 295 return PACKET_REJECT; 296 297 if (__iptunnel_pull_header(skb, 298 len, 299 htons(ETH_P_TEB), 300 false, false) < 0) 301 goto drop; 302 303 if (tunnel->collect_md) { 304 struct erspan_metadata *pkt_md, *md; 305 struct ip_tunnel_info *info; 306 unsigned char *gh; 307 __be64 tun_id; 308 __be16 flags; 309 310 tpi->flags |= TUNNEL_KEY; 311 flags = tpi->flags; 312 tun_id = key32_to_tunnel_id(tpi->key); 313 314 tun_dst = ip_tun_rx_dst(skb, flags, 315 tun_id, sizeof(*md)); 316 if (!tun_dst) 317 return PACKET_REJECT; 318 319 /* skb can be uncloned in __iptunnel_pull_header, so 320 * old pkt_md is no longer valid and we need to reset 321 * it 322 */ 323 gh = skb_network_header(skb) + 324 skb_network_header_len(skb); 325 pkt_md = (struct erspan_metadata *)(gh + gre_hdr_len + 326 sizeof(*ershdr)); 327 md = ip_tunnel_info_opts(&tun_dst->u.tun_info); 328 md->version = ver; 329 md2 = &md->u.md2; 330 memcpy(md2, pkt_md, ver == 1 ? ERSPAN_V1_MDSIZE : 331 ERSPAN_V2_MDSIZE); 332 333 info = &tun_dst->u.tun_info; 334 info->key.tun_flags |= TUNNEL_ERSPAN_OPT; 335 info->options_len = sizeof(*md); 336 } 337 338 skb_reset_mac_header(skb); 339 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error); 340 return PACKET_RCVD; 341 } 342 return PACKET_REJECT; 343 344 drop: 345 kfree_skb(skb); 346 return PACKET_RCVD; 347 } 348 349 static int __ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi, 350 struct ip_tunnel_net *itn, int hdr_len, bool raw_proto) 351 { 352 struct metadata_dst *tun_dst = NULL; 353 const struct iphdr *iph; 354 struct ip_tunnel *tunnel; 355 356 iph = ip_hdr(skb); 357 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags, 358 iph->saddr, iph->daddr, tpi->key); 359 360 if (tunnel) { 361 const struct iphdr *tnl_params; 362 363 if (__iptunnel_pull_header(skb, hdr_len, tpi->proto, 364 raw_proto, false) < 0) 365 goto drop; 366 367 if (tunnel->dev->type != ARPHRD_NONE) 368 skb_pop_mac_header(skb); 369 else 370 skb_reset_mac_header(skb); 371 372 tnl_params = &tunnel->parms.iph; 373 if (tunnel->collect_md || tnl_params->daddr == 0) { 374 __be16 flags; 375 __be64 tun_id; 376 377 flags = tpi->flags & (TUNNEL_CSUM | TUNNEL_KEY); 378 tun_id = key32_to_tunnel_id(tpi->key); 379 tun_dst = ip_tun_rx_dst(skb, flags, tun_id, 0); 380 if (!tun_dst) 381 return PACKET_REJECT; 382 } 383 384 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error); 385 return PACKET_RCVD; 386 } 387 return PACKET_NEXT; 388 389 drop: 390 kfree_skb(skb); 391 return PACKET_RCVD; 392 } 393 394 static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi, 395 int hdr_len) 396 { 397 struct net *net = dev_net(skb->dev); 398 struct ip_tunnel_net *itn; 399 int res; 400 401 if (tpi->proto == htons(ETH_P_TEB)) 402 itn = net_generic(net, gre_tap_net_id); 403 else 404 itn = net_generic(net, ipgre_net_id); 405 406 res = __ipgre_rcv(skb, tpi, itn, hdr_len, false); 407 if (res == PACKET_NEXT && tpi->proto == htons(ETH_P_TEB)) { 408 /* ipgre tunnels in collect metadata mode should receive 409 * also ETH_P_TEB traffic. 410 */ 411 itn = net_generic(net, ipgre_net_id); 412 res = __ipgre_rcv(skb, tpi, itn, hdr_len, true); 413 } 414 return res; 415 } 416 417 static int gre_rcv(struct sk_buff *skb) 418 { 419 struct tnl_ptk_info tpi; 420 bool csum_err = false; 421 int hdr_len; 422 423 #ifdef CONFIG_NET_IPGRE_BROADCAST 424 if (ipv4_is_multicast(ip_hdr(skb)->daddr)) { 425 /* Looped back packet, drop it! */ 426 if (rt_is_output_route(skb_rtable(skb))) 427 goto drop; 428 } 429 #endif 430 431 hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IP), 0); 432 if (hdr_len < 0) 433 goto drop; 434 435 if (unlikely(tpi.proto == htons(ETH_P_ERSPAN) || 436 tpi.proto == htons(ETH_P_ERSPAN2))) { 437 if (erspan_rcv(skb, &tpi, hdr_len) == PACKET_RCVD) 438 return 0; 439 goto out; 440 } 441 442 if (ipgre_rcv(skb, &tpi, hdr_len) == PACKET_RCVD) 443 return 0; 444 445 out: 446 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 447 drop: 448 kfree_skb(skb); 449 return 0; 450 } 451 452 static void __gre_xmit(struct sk_buff *skb, struct net_device *dev, 453 const struct iphdr *tnl_params, 454 __be16 proto) 455 { 456 struct ip_tunnel *tunnel = netdev_priv(dev); 457 458 if (tunnel->parms.o_flags & TUNNEL_SEQ) 459 tunnel->o_seqno++; 460 461 /* Push GRE header. */ 462 gre_build_header(skb, tunnel->tun_hlen, 463 tunnel->parms.o_flags, proto, tunnel->parms.o_key, 464 htonl(tunnel->o_seqno)); 465 466 ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol); 467 } 468 469 static int gre_handle_offloads(struct sk_buff *skb, bool csum) 470 { 471 return iptunnel_handle_offloads(skb, csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE); 472 } 473 474 static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev, 475 __be16 proto) 476 { 477 struct ip_tunnel *tunnel = netdev_priv(dev); 478 struct ip_tunnel_info *tun_info; 479 const struct ip_tunnel_key *key; 480 int tunnel_hlen; 481 __be16 flags; 482 483 tun_info = skb_tunnel_info(skb); 484 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) || 485 ip_tunnel_info_af(tun_info) != AF_INET)) 486 goto err_free_skb; 487 488 key = &tun_info->key; 489 tunnel_hlen = gre_calc_hlen(key->tun_flags); 490 491 if (skb_cow_head(skb, dev->needed_headroom)) 492 goto err_free_skb; 493 494 /* Push Tunnel header. */ 495 if (gre_handle_offloads(skb, !!(tun_info->key.tun_flags & TUNNEL_CSUM))) 496 goto err_free_skb; 497 498 flags = tun_info->key.tun_flags & 499 (TUNNEL_CSUM | TUNNEL_KEY | TUNNEL_SEQ); 500 gre_build_header(skb, tunnel_hlen, flags, proto, 501 tunnel_id_to_key32(tun_info->key.tun_id), 502 (flags & TUNNEL_SEQ) ? htonl(tunnel->o_seqno++) : 0); 503 504 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen); 505 506 return; 507 508 err_free_skb: 509 kfree_skb(skb); 510 dev->stats.tx_dropped++; 511 } 512 513 static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev) 514 { 515 struct ip_tunnel *tunnel = netdev_priv(dev); 516 struct ip_tunnel_info *tun_info; 517 const struct ip_tunnel_key *key; 518 struct erspan_metadata *md; 519 bool truncate = false; 520 __be16 proto; 521 int tunnel_hlen; 522 int version; 523 int nhoff; 524 int thoff; 525 526 tun_info = skb_tunnel_info(skb); 527 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) || 528 ip_tunnel_info_af(tun_info) != AF_INET)) 529 goto err_free_skb; 530 531 key = &tun_info->key; 532 if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT)) 533 goto err_free_skb; 534 if (tun_info->options_len < sizeof(*md)) 535 goto err_free_skb; 536 md = ip_tunnel_info_opts(tun_info); 537 538 /* ERSPAN has fixed 8 byte GRE header */ 539 version = md->version; 540 tunnel_hlen = 8 + erspan_hdr_len(version); 541 542 if (skb_cow_head(skb, dev->needed_headroom)) 543 goto err_free_skb; 544 545 if (gre_handle_offloads(skb, false)) 546 goto err_free_skb; 547 548 if (skb->len > dev->mtu + dev->hard_header_len) { 549 pskb_trim(skb, dev->mtu + dev->hard_header_len); 550 truncate = true; 551 } 552 553 nhoff = skb_network_header(skb) - skb_mac_header(skb); 554 if (skb->protocol == htons(ETH_P_IP) && 555 (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff)) 556 truncate = true; 557 558 thoff = skb_transport_header(skb) - skb_mac_header(skb); 559 if (skb->protocol == htons(ETH_P_IPV6) && 560 (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff)) 561 truncate = true; 562 563 if (version == 1) { 564 erspan_build_header(skb, ntohl(tunnel_id_to_key32(key->tun_id)), 565 ntohl(md->u.index), truncate, true); 566 proto = htons(ETH_P_ERSPAN); 567 } else if (version == 2) { 568 erspan_build_header_v2(skb, 569 ntohl(tunnel_id_to_key32(key->tun_id)), 570 md->u.md2.dir, 571 get_hwid(&md->u.md2), 572 truncate, true); 573 proto = htons(ETH_P_ERSPAN2); 574 } else { 575 goto err_free_skb; 576 } 577 578 gre_build_header(skb, 8, TUNNEL_SEQ, 579 proto, 0, htonl(tunnel->o_seqno++)); 580 581 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen); 582 583 return; 584 585 err_free_skb: 586 kfree_skb(skb); 587 dev->stats.tx_dropped++; 588 } 589 590 static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb) 591 { 592 struct ip_tunnel_info *info = skb_tunnel_info(skb); 593 const struct ip_tunnel_key *key; 594 struct rtable *rt; 595 struct flowi4 fl4; 596 597 if (ip_tunnel_info_af(info) != AF_INET) 598 return -EINVAL; 599 600 key = &info->key; 601 ip_tunnel_init_flow(&fl4, IPPROTO_GRE, key->u.ipv4.dst, key->u.ipv4.src, 602 tunnel_id_to_key32(key->tun_id), key->tos, 0, 603 skb->mark, skb_get_hash(skb)); 604 rt = ip_route_output_key(dev_net(dev), &fl4); 605 if (IS_ERR(rt)) 606 return PTR_ERR(rt); 607 608 ip_rt_put(rt); 609 info->key.u.ipv4.src = fl4.saddr; 610 return 0; 611 } 612 613 static netdev_tx_t ipgre_xmit(struct sk_buff *skb, 614 struct net_device *dev) 615 { 616 struct ip_tunnel *tunnel = netdev_priv(dev); 617 const struct iphdr *tnl_params; 618 619 if (!pskb_inet_may_pull(skb)) 620 goto free_skb; 621 622 if (tunnel->collect_md) { 623 gre_fb_xmit(skb, dev, skb->protocol); 624 return NETDEV_TX_OK; 625 } 626 627 if (dev->header_ops) { 628 /* Need space for new headers */ 629 if (skb_cow_head(skb, dev->needed_headroom - 630 (tunnel->hlen + sizeof(struct iphdr)))) 631 goto free_skb; 632 633 tnl_params = (const struct iphdr *)skb->data; 634 635 /* Pull skb since ip_tunnel_xmit() needs skb->data pointing 636 * to gre header. 637 */ 638 skb_pull(skb, tunnel->hlen + sizeof(struct iphdr)); 639 skb_reset_mac_header(skb); 640 } else { 641 if (skb_cow_head(skb, dev->needed_headroom)) 642 goto free_skb; 643 644 tnl_params = &tunnel->parms.iph; 645 } 646 647 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM))) 648 goto free_skb; 649 650 __gre_xmit(skb, dev, tnl_params, skb->protocol); 651 return NETDEV_TX_OK; 652 653 free_skb: 654 kfree_skb(skb); 655 dev->stats.tx_dropped++; 656 return NETDEV_TX_OK; 657 } 658 659 static netdev_tx_t erspan_xmit(struct sk_buff *skb, 660 struct net_device *dev) 661 { 662 struct ip_tunnel *tunnel = netdev_priv(dev); 663 bool truncate = false; 664 __be16 proto; 665 666 if (!pskb_inet_may_pull(skb)) 667 goto free_skb; 668 669 if (tunnel->collect_md) { 670 erspan_fb_xmit(skb, dev); 671 return NETDEV_TX_OK; 672 } 673 674 if (gre_handle_offloads(skb, false)) 675 goto free_skb; 676 677 if (skb_cow_head(skb, dev->needed_headroom)) 678 goto free_skb; 679 680 if (skb->len > dev->mtu + dev->hard_header_len) { 681 pskb_trim(skb, dev->mtu + dev->hard_header_len); 682 truncate = true; 683 } 684 685 /* Push ERSPAN header */ 686 if (tunnel->erspan_ver == 0) { 687 proto = htons(ETH_P_ERSPAN); 688 tunnel->parms.o_flags &= ~TUNNEL_SEQ; 689 } else if (tunnel->erspan_ver == 1) { 690 erspan_build_header(skb, ntohl(tunnel->parms.o_key), 691 tunnel->index, 692 truncate, true); 693 proto = htons(ETH_P_ERSPAN); 694 } else if (tunnel->erspan_ver == 2) { 695 erspan_build_header_v2(skb, ntohl(tunnel->parms.o_key), 696 tunnel->dir, tunnel->hwid, 697 truncate, true); 698 proto = htons(ETH_P_ERSPAN2); 699 } else { 700 goto free_skb; 701 } 702 703 tunnel->parms.o_flags &= ~TUNNEL_KEY; 704 __gre_xmit(skb, dev, &tunnel->parms.iph, proto); 705 return NETDEV_TX_OK; 706 707 free_skb: 708 kfree_skb(skb); 709 dev->stats.tx_dropped++; 710 return NETDEV_TX_OK; 711 } 712 713 static netdev_tx_t gre_tap_xmit(struct sk_buff *skb, 714 struct net_device *dev) 715 { 716 struct ip_tunnel *tunnel = netdev_priv(dev); 717 718 if (!pskb_inet_may_pull(skb)) 719 goto free_skb; 720 721 if (tunnel->collect_md) { 722 gre_fb_xmit(skb, dev, htons(ETH_P_TEB)); 723 return NETDEV_TX_OK; 724 } 725 726 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM))) 727 goto free_skb; 728 729 if (skb_cow_head(skb, dev->needed_headroom)) 730 goto free_skb; 731 732 __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB)); 733 return NETDEV_TX_OK; 734 735 free_skb: 736 kfree_skb(skb); 737 dev->stats.tx_dropped++; 738 return NETDEV_TX_OK; 739 } 740 741 static void ipgre_link_update(struct net_device *dev, bool set_mtu) 742 { 743 struct ip_tunnel *tunnel = netdev_priv(dev); 744 int len; 745 746 len = tunnel->tun_hlen; 747 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags); 748 len = tunnel->tun_hlen - len; 749 tunnel->hlen = tunnel->hlen + len; 750 751 dev->needed_headroom = dev->needed_headroom + len; 752 if (set_mtu) 753 dev->mtu = max_t(int, dev->mtu - len, 68); 754 755 if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) { 756 if (!(tunnel->parms.o_flags & TUNNEL_CSUM) || 757 tunnel->encap.type == TUNNEL_ENCAP_NONE) { 758 dev->features |= NETIF_F_GSO_SOFTWARE; 759 dev->hw_features |= NETIF_F_GSO_SOFTWARE; 760 } else { 761 dev->features &= ~NETIF_F_GSO_SOFTWARE; 762 dev->hw_features &= ~NETIF_F_GSO_SOFTWARE; 763 } 764 dev->features |= NETIF_F_LLTX; 765 } else { 766 dev->hw_features &= ~NETIF_F_GSO_SOFTWARE; 767 dev->features &= ~(NETIF_F_LLTX | NETIF_F_GSO_SOFTWARE); 768 } 769 } 770 771 static int ipgre_tunnel_ioctl(struct net_device *dev, 772 struct ifreq *ifr, int cmd) 773 { 774 struct ip_tunnel_parm p; 775 int err; 776 777 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 778 return -EFAULT; 779 780 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) { 781 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE || 782 p.iph.ihl != 5 || (p.iph.frag_off & htons(~IP_DF)) || 783 ((p.i_flags | p.o_flags) & (GRE_VERSION | GRE_ROUTING))) 784 return -EINVAL; 785 } 786 787 p.i_flags = gre_flags_to_tnl_flags(p.i_flags); 788 p.o_flags = gre_flags_to_tnl_flags(p.o_flags); 789 790 err = ip_tunnel_ioctl(dev, &p, cmd); 791 if (err) 792 return err; 793 794 if (cmd == SIOCCHGTUNNEL) { 795 struct ip_tunnel *t = netdev_priv(dev); 796 797 t->parms.i_flags = p.i_flags; 798 t->parms.o_flags = p.o_flags; 799 800 if (strcmp(dev->rtnl_link_ops->kind, "erspan")) 801 ipgre_link_update(dev, true); 802 } 803 804 p.i_flags = gre_tnl_flags_to_gre_flags(p.i_flags); 805 p.o_flags = gre_tnl_flags_to_gre_flags(p.o_flags); 806 807 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 808 return -EFAULT; 809 810 return 0; 811 } 812 813 /* Nice toy. Unfortunately, useless in real life :-) 814 It allows to construct virtual multiprotocol broadcast "LAN" 815 over the Internet, provided multicast routing is tuned. 816 817 818 I have no idea was this bicycle invented before me, 819 so that I had to set ARPHRD_IPGRE to a random value. 820 I have an impression, that Cisco could make something similar, 821 but this feature is apparently missing in IOS<=11.2(8). 822 823 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks 824 with broadcast 224.66.66.66. If you have access to mbone, play with me :-) 825 826 ping -t 255 224.66.66.66 827 828 If nobody answers, mbone does not work. 829 830 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255 831 ip addr add 10.66.66.<somewhat>/24 dev Universe 832 ifconfig Universe up 833 ifconfig Universe add fe80::<Your_real_addr>/10 834 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96 835 ftp 10.66.66.66 836 ... 837 ftp fec0:6666:6666::193.233.7.65 838 ... 839 */ 840 static int ipgre_header(struct sk_buff *skb, struct net_device *dev, 841 unsigned short type, 842 const void *daddr, const void *saddr, unsigned int len) 843 { 844 struct ip_tunnel *t = netdev_priv(dev); 845 struct iphdr *iph; 846 struct gre_base_hdr *greh; 847 848 iph = skb_push(skb, t->hlen + sizeof(*iph)); 849 greh = (struct gre_base_hdr *)(iph+1); 850 greh->flags = gre_tnl_flags_to_gre_flags(t->parms.o_flags); 851 greh->protocol = htons(type); 852 853 memcpy(iph, &t->parms.iph, sizeof(struct iphdr)); 854 855 /* Set the source hardware address. */ 856 if (saddr) 857 memcpy(&iph->saddr, saddr, 4); 858 if (daddr) 859 memcpy(&iph->daddr, daddr, 4); 860 if (iph->daddr) 861 return t->hlen + sizeof(*iph); 862 863 return -(t->hlen + sizeof(*iph)); 864 } 865 866 static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr) 867 { 868 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb); 869 memcpy(haddr, &iph->saddr, 4); 870 return 4; 871 } 872 873 static const struct header_ops ipgre_header_ops = { 874 .create = ipgre_header, 875 .parse = ipgre_header_parse, 876 }; 877 878 #ifdef CONFIG_NET_IPGRE_BROADCAST 879 static int ipgre_open(struct net_device *dev) 880 { 881 struct ip_tunnel *t = netdev_priv(dev); 882 883 if (ipv4_is_multicast(t->parms.iph.daddr)) { 884 struct flowi4 fl4; 885 struct rtable *rt; 886 887 rt = ip_route_output_gre(t->net, &fl4, 888 t->parms.iph.daddr, 889 t->parms.iph.saddr, 890 t->parms.o_key, 891 RT_TOS(t->parms.iph.tos), 892 t->parms.link); 893 if (IS_ERR(rt)) 894 return -EADDRNOTAVAIL; 895 dev = rt->dst.dev; 896 ip_rt_put(rt); 897 if (!__in_dev_get_rtnl(dev)) 898 return -EADDRNOTAVAIL; 899 t->mlink = dev->ifindex; 900 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr); 901 } 902 return 0; 903 } 904 905 static int ipgre_close(struct net_device *dev) 906 { 907 struct ip_tunnel *t = netdev_priv(dev); 908 909 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) { 910 struct in_device *in_dev; 911 in_dev = inetdev_by_index(t->net, t->mlink); 912 if (in_dev) 913 ip_mc_dec_group(in_dev, t->parms.iph.daddr); 914 } 915 return 0; 916 } 917 #endif 918 919 static const struct net_device_ops ipgre_netdev_ops = { 920 .ndo_init = ipgre_tunnel_init, 921 .ndo_uninit = ip_tunnel_uninit, 922 #ifdef CONFIG_NET_IPGRE_BROADCAST 923 .ndo_open = ipgre_open, 924 .ndo_stop = ipgre_close, 925 #endif 926 .ndo_start_xmit = ipgre_xmit, 927 .ndo_do_ioctl = ipgre_tunnel_ioctl, 928 .ndo_change_mtu = ip_tunnel_change_mtu, 929 .ndo_get_stats64 = ip_tunnel_get_stats64, 930 .ndo_get_iflink = ip_tunnel_get_iflink, 931 }; 932 933 #define GRE_FEATURES (NETIF_F_SG | \ 934 NETIF_F_FRAGLIST | \ 935 NETIF_F_HIGHDMA | \ 936 NETIF_F_HW_CSUM) 937 938 static void ipgre_tunnel_setup(struct net_device *dev) 939 { 940 dev->netdev_ops = &ipgre_netdev_ops; 941 dev->type = ARPHRD_IPGRE; 942 ip_tunnel_setup(dev, ipgre_net_id); 943 } 944 945 static void __gre_tunnel_init(struct net_device *dev) 946 { 947 struct ip_tunnel *tunnel; 948 949 tunnel = netdev_priv(dev); 950 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags); 951 tunnel->parms.iph.protocol = IPPROTO_GRE; 952 953 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen; 954 955 dev->features |= GRE_FEATURES; 956 dev->hw_features |= GRE_FEATURES; 957 958 if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) { 959 /* TCP offload with GRE SEQ is not supported, nor 960 * can we support 2 levels of outer headers requiring 961 * an update. 962 */ 963 if (!(tunnel->parms.o_flags & TUNNEL_CSUM) || 964 (tunnel->encap.type == TUNNEL_ENCAP_NONE)) { 965 dev->features |= NETIF_F_GSO_SOFTWARE; 966 dev->hw_features |= NETIF_F_GSO_SOFTWARE; 967 } 968 969 /* Can use a lockless transmit, unless we generate 970 * output sequences 971 */ 972 dev->features |= NETIF_F_LLTX; 973 } 974 } 975 976 static int ipgre_tunnel_init(struct net_device *dev) 977 { 978 struct ip_tunnel *tunnel = netdev_priv(dev); 979 struct iphdr *iph = &tunnel->parms.iph; 980 981 __gre_tunnel_init(dev); 982 983 memcpy(dev->dev_addr, &iph->saddr, 4); 984 memcpy(dev->broadcast, &iph->daddr, 4); 985 986 dev->flags = IFF_NOARP; 987 netif_keep_dst(dev); 988 dev->addr_len = 4; 989 990 if (iph->daddr && !tunnel->collect_md) { 991 #ifdef CONFIG_NET_IPGRE_BROADCAST 992 if (ipv4_is_multicast(iph->daddr)) { 993 if (!iph->saddr) 994 return -EINVAL; 995 dev->flags = IFF_BROADCAST; 996 dev->header_ops = &ipgre_header_ops; 997 } 998 #endif 999 } else if (!tunnel->collect_md) { 1000 dev->header_ops = &ipgre_header_ops; 1001 } 1002 1003 return ip_tunnel_init(dev); 1004 } 1005 1006 static const struct gre_protocol ipgre_protocol = { 1007 .handler = gre_rcv, 1008 .err_handler = gre_err, 1009 }; 1010 1011 static int __net_init ipgre_init_net(struct net *net) 1012 { 1013 return ip_tunnel_init_net(net, ipgre_net_id, &ipgre_link_ops, NULL); 1014 } 1015 1016 static void __net_exit ipgre_exit_batch_net(struct list_head *list_net) 1017 { 1018 ip_tunnel_delete_nets(list_net, ipgre_net_id, &ipgre_link_ops); 1019 } 1020 1021 static struct pernet_operations ipgre_net_ops = { 1022 .init = ipgre_init_net, 1023 .exit_batch = ipgre_exit_batch_net, 1024 .id = &ipgre_net_id, 1025 .size = sizeof(struct ip_tunnel_net), 1026 }; 1027 1028 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[], 1029 struct netlink_ext_ack *extack) 1030 { 1031 __be16 flags; 1032 1033 if (!data) 1034 return 0; 1035 1036 flags = 0; 1037 if (data[IFLA_GRE_IFLAGS]) 1038 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); 1039 if (data[IFLA_GRE_OFLAGS]) 1040 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); 1041 if (flags & (GRE_VERSION|GRE_ROUTING)) 1042 return -EINVAL; 1043 1044 if (data[IFLA_GRE_COLLECT_METADATA] && 1045 data[IFLA_GRE_ENCAP_TYPE] && 1046 nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]) != TUNNEL_ENCAP_NONE) 1047 return -EINVAL; 1048 1049 return 0; 1050 } 1051 1052 static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[], 1053 struct netlink_ext_ack *extack) 1054 { 1055 __be32 daddr; 1056 1057 if (tb[IFLA_ADDRESS]) { 1058 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) 1059 return -EINVAL; 1060 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) 1061 return -EADDRNOTAVAIL; 1062 } 1063 1064 if (!data) 1065 goto out; 1066 1067 if (data[IFLA_GRE_REMOTE]) { 1068 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4); 1069 if (!daddr) 1070 return -EINVAL; 1071 } 1072 1073 out: 1074 return ipgre_tunnel_validate(tb, data, extack); 1075 } 1076 1077 static int erspan_validate(struct nlattr *tb[], struct nlattr *data[], 1078 struct netlink_ext_ack *extack) 1079 { 1080 __be16 flags = 0; 1081 int ret; 1082 1083 if (!data) 1084 return 0; 1085 1086 ret = ipgre_tap_validate(tb, data, extack); 1087 if (ret) 1088 return ret; 1089 1090 if (nla_get_u8(data[IFLA_GRE_ERSPAN_VER]) == 0) 1091 return 0; 1092 1093 /* ERSPAN type II/III should only have GRE sequence and key flag */ 1094 if (data[IFLA_GRE_OFLAGS]) 1095 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); 1096 if (data[IFLA_GRE_IFLAGS]) 1097 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); 1098 if (!data[IFLA_GRE_COLLECT_METADATA] && 1099 flags != (GRE_SEQ | GRE_KEY)) 1100 return -EINVAL; 1101 1102 /* ERSPAN Session ID only has 10-bit. Since we reuse 1103 * 32-bit key field as ID, check it's range. 1104 */ 1105 if (data[IFLA_GRE_IKEY] && 1106 (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK)) 1107 return -EINVAL; 1108 1109 if (data[IFLA_GRE_OKEY] && 1110 (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK)) 1111 return -EINVAL; 1112 1113 return 0; 1114 } 1115 1116 static int ipgre_netlink_parms(struct net_device *dev, 1117 struct nlattr *data[], 1118 struct nlattr *tb[], 1119 struct ip_tunnel_parm *parms, 1120 __u32 *fwmark) 1121 { 1122 struct ip_tunnel *t = netdev_priv(dev); 1123 1124 memset(parms, 0, sizeof(*parms)); 1125 1126 parms->iph.protocol = IPPROTO_GRE; 1127 1128 if (!data) 1129 return 0; 1130 1131 if (data[IFLA_GRE_LINK]) 1132 parms->link = nla_get_u32(data[IFLA_GRE_LINK]); 1133 1134 if (data[IFLA_GRE_IFLAGS]) 1135 parms->i_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_IFLAGS])); 1136 1137 if (data[IFLA_GRE_OFLAGS]) 1138 parms->o_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_OFLAGS])); 1139 1140 if (data[IFLA_GRE_IKEY]) 1141 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]); 1142 1143 if (data[IFLA_GRE_OKEY]) 1144 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]); 1145 1146 if (data[IFLA_GRE_LOCAL]) 1147 parms->iph.saddr = nla_get_in_addr(data[IFLA_GRE_LOCAL]); 1148 1149 if (data[IFLA_GRE_REMOTE]) 1150 parms->iph.daddr = nla_get_in_addr(data[IFLA_GRE_REMOTE]); 1151 1152 if (data[IFLA_GRE_TTL]) 1153 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]); 1154 1155 if (data[IFLA_GRE_TOS]) 1156 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]); 1157 1158 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC])) { 1159 if (t->ignore_df) 1160 return -EINVAL; 1161 parms->iph.frag_off = htons(IP_DF); 1162 } 1163 1164 if (data[IFLA_GRE_COLLECT_METADATA]) { 1165 t->collect_md = true; 1166 if (dev->type == ARPHRD_IPGRE) 1167 dev->type = ARPHRD_NONE; 1168 } 1169 1170 if (data[IFLA_GRE_IGNORE_DF]) { 1171 if (nla_get_u8(data[IFLA_GRE_IGNORE_DF]) 1172 && (parms->iph.frag_off & htons(IP_DF))) 1173 return -EINVAL; 1174 t->ignore_df = !!nla_get_u8(data[IFLA_GRE_IGNORE_DF]); 1175 } 1176 1177 if (data[IFLA_GRE_FWMARK]) 1178 *fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]); 1179 1180 return 0; 1181 } 1182 1183 static int erspan_netlink_parms(struct net_device *dev, 1184 struct nlattr *data[], 1185 struct nlattr *tb[], 1186 struct ip_tunnel_parm *parms, 1187 __u32 *fwmark) 1188 { 1189 struct ip_tunnel *t = netdev_priv(dev); 1190 int err; 1191 1192 err = ipgre_netlink_parms(dev, data, tb, parms, fwmark); 1193 if (err) 1194 return err; 1195 if (!data) 1196 return 0; 1197 1198 if (data[IFLA_GRE_ERSPAN_VER]) { 1199 t->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]); 1200 1201 if (t->erspan_ver > 2) 1202 return -EINVAL; 1203 } 1204 1205 if (t->erspan_ver == 1) { 1206 if (data[IFLA_GRE_ERSPAN_INDEX]) { 1207 t->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]); 1208 if (t->index & ~INDEX_MASK) 1209 return -EINVAL; 1210 } 1211 } else if (t->erspan_ver == 2) { 1212 if (data[IFLA_GRE_ERSPAN_DIR]) { 1213 t->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]); 1214 if (t->dir & ~(DIR_MASK >> DIR_OFFSET)) 1215 return -EINVAL; 1216 } 1217 if (data[IFLA_GRE_ERSPAN_HWID]) { 1218 t->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]); 1219 if (t->hwid & ~(HWID_MASK >> HWID_OFFSET)) 1220 return -EINVAL; 1221 } 1222 } 1223 1224 return 0; 1225 } 1226 1227 /* This function returns true when ENCAP attributes are present in the nl msg */ 1228 static bool ipgre_netlink_encap_parms(struct nlattr *data[], 1229 struct ip_tunnel_encap *ipencap) 1230 { 1231 bool ret = false; 1232 1233 memset(ipencap, 0, sizeof(*ipencap)); 1234 1235 if (!data) 1236 return ret; 1237 1238 if (data[IFLA_GRE_ENCAP_TYPE]) { 1239 ret = true; 1240 ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]); 1241 } 1242 1243 if (data[IFLA_GRE_ENCAP_FLAGS]) { 1244 ret = true; 1245 ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]); 1246 } 1247 1248 if (data[IFLA_GRE_ENCAP_SPORT]) { 1249 ret = true; 1250 ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]); 1251 } 1252 1253 if (data[IFLA_GRE_ENCAP_DPORT]) { 1254 ret = true; 1255 ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]); 1256 } 1257 1258 return ret; 1259 } 1260 1261 static int gre_tap_init(struct net_device *dev) 1262 { 1263 __gre_tunnel_init(dev); 1264 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1265 netif_keep_dst(dev); 1266 1267 return ip_tunnel_init(dev); 1268 } 1269 1270 static const struct net_device_ops gre_tap_netdev_ops = { 1271 .ndo_init = gre_tap_init, 1272 .ndo_uninit = ip_tunnel_uninit, 1273 .ndo_start_xmit = gre_tap_xmit, 1274 .ndo_set_mac_address = eth_mac_addr, 1275 .ndo_validate_addr = eth_validate_addr, 1276 .ndo_change_mtu = ip_tunnel_change_mtu, 1277 .ndo_get_stats64 = ip_tunnel_get_stats64, 1278 .ndo_get_iflink = ip_tunnel_get_iflink, 1279 .ndo_fill_metadata_dst = gre_fill_metadata_dst, 1280 }; 1281 1282 static int erspan_tunnel_init(struct net_device *dev) 1283 { 1284 struct ip_tunnel *tunnel = netdev_priv(dev); 1285 1286 if (tunnel->erspan_ver == 0) 1287 tunnel->tun_hlen = 4; /* 4-byte GRE hdr. */ 1288 else 1289 tunnel->tun_hlen = 8; /* 8-byte GRE hdr. */ 1290 1291 tunnel->parms.iph.protocol = IPPROTO_GRE; 1292 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen + 1293 erspan_hdr_len(tunnel->erspan_ver); 1294 1295 dev->features |= GRE_FEATURES; 1296 dev->hw_features |= GRE_FEATURES; 1297 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1298 netif_keep_dst(dev); 1299 1300 return ip_tunnel_init(dev); 1301 } 1302 1303 static const struct net_device_ops erspan_netdev_ops = { 1304 .ndo_init = erspan_tunnel_init, 1305 .ndo_uninit = ip_tunnel_uninit, 1306 .ndo_start_xmit = erspan_xmit, 1307 .ndo_set_mac_address = eth_mac_addr, 1308 .ndo_validate_addr = eth_validate_addr, 1309 .ndo_change_mtu = ip_tunnel_change_mtu, 1310 .ndo_get_stats64 = ip_tunnel_get_stats64, 1311 .ndo_get_iflink = ip_tunnel_get_iflink, 1312 .ndo_fill_metadata_dst = gre_fill_metadata_dst, 1313 }; 1314 1315 static void ipgre_tap_setup(struct net_device *dev) 1316 { 1317 ether_setup(dev); 1318 dev->max_mtu = 0; 1319 dev->netdev_ops = &gre_tap_netdev_ops; 1320 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 1321 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1322 ip_tunnel_setup(dev, gre_tap_net_id); 1323 } 1324 1325 static int 1326 ipgre_newlink_encap_setup(struct net_device *dev, struct nlattr *data[]) 1327 { 1328 struct ip_tunnel_encap ipencap; 1329 1330 if (ipgre_netlink_encap_parms(data, &ipencap)) { 1331 struct ip_tunnel *t = netdev_priv(dev); 1332 int err = ip_tunnel_encap_setup(t, &ipencap); 1333 1334 if (err < 0) 1335 return err; 1336 } 1337 1338 return 0; 1339 } 1340 1341 static int ipgre_newlink(struct net *src_net, struct net_device *dev, 1342 struct nlattr *tb[], struct nlattr *data[], 1343 struct netlink_ext_ack *extack) 1344 { 1345 struct ip_tunnel_parm p; 1346 __u32 fwmark = 0; 1347 int err; 1348 1349 err = ipgre_newlink_encap_setup(dev, data); 1350 if (err) 1351 return err; 1352 1353 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark); 1354 if (err < 0) 1355 return err; 1356 return ip_tunnel_newlink(dev, tb, &p, fwmark); 1357 } 1358 1359 static int erspan_newlink(struct net *src_net, struct net_device *dev, 1360 struct nlattr *tb[], struct nlattr *data[], 1361 struct netlink_ext_ack *extack) 1362 { 1363 struct ip_tunnel_parm p; 1364 __u32 fwmark = 0; 1365 int err; 1366 1367 err = ipgre_newlink_encap_setup(dev, data); 1368 if (err) 1369 return err; 1370 1371 err = erspan_netlink_parms(dev, data, tb, &p, &fwmark); 1372 if (err) 1373 return err; 1374 return ip_tunnel_newlink(dev, tb, &p, fwmark); 1375 } 1376 1377 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[], 1378 struct nlattr *data[], 1379 struct netlink_ext_ack *extack) 1380 { 1381 struct ip_tunnel *t = netdev_priv(dev); 1382 __u32 fwmark = t->fwmark; 1383 struct ip_tunnel_parm p; 1384 int err; 1385 1386 err = ipgre_newlink_encap_setup(dev, data); 1387 if (err) 1388 return err; 1389 1390 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark); 1391 if (err < 0) 1392 return err; 1393 1394 err = ip_tunnel_changelink(dev, tb, &p, fwmark); 1395 if (err < 0) 1396 return err; 1397 1398 t->parms.i_flags = p.i_flags; 1399 t->parms.o_flags = p.o_flags; 1400 1401 ipgre_link_update(dev, !tb[IFLA_MTU]); 1402 1403 return 0; 1404 } 1405 1406 static int erspan_changelink(struct net_device *dev, struct nlattr *tb[], 1407 struct nlattr *data[], 1408 struct netlink_ext_ack *extack) 1409 { 1410 struct ip_tunnel *t = netdev_priv(dev); 1411 __u32 fwmark = t->fwmark; 1412 struct ip_tunnel_parm p; 1413 int err; 1414 1415 err = ipgre_newlink_encap_setup(dev, data); 1416 if (err) 1417 return err; 1418 1419 err = erspan_netlink_parms(dev, data, tb, &p, &fwmark); 1420 if (err < 0) 1421 return err; 1422 1423 err = ip_tunnel_changelink(dev, tb, &p, fwmark); 1424 if (err < 0) 1425 return err; 1426 1427 t->parms.i_flags = p.i_flags; 1428 t->parms.o_flags = p.o_flags; 1429 1430 return 0; 1431 } 1432 1433 static size_t ipgre_get_size(const struct net_device *dev) 1434 { 1435 return 1436 /* IFLA_GRE_LINK */ 1437 nla_total_size(4) + 1438 /* IFLA_GRE_IFLAGS */ 1439 nla_total_size(2) + 1440 /* IFLA_GRE_OFLAGS */ 1441 nla_total_size(2) + 1442 /* IFLA_GRE_IKEY */ 1443 nla_total_size(4) + 1444 /* IFLA_GRE_OKEY */ 1445 nla_total_size(4) + 1446 /* IFLA_GRE_LOCAL */ 1447 nla_total_size(4) + 1448 /* IFLA_GRE_REMOTE */ 1449 nla_total_size(4) + 1450 /* IFLA_GRE_TTL */ 1451 nla_total_size(1) + 1452 /* IFLA_GRE_TOS */ 1453 nla_total_size(1) + 1454 /* IFLA_GRE_PMTUDISC */ 1455 nla_total_size(1) + 1456 /* IFLA_GRE_ENCAP_TYPE */ 1457 nla_total_size(2) + 1458 /* IFLA_GRE_ENCAP_FLAGS */ 1459 nla_total_size(2) + 1460 /* IFLA_GRE_ENCAP_SPORT */ 1461 nla_total_size(2) + 1462 /* IFLA_GRE_ENCAP_DPORT */ 1463 nla_total_size(2) + 1464 /* IFLA_GRE_COLLECT_METADATA */ 1465 nla_total_size(0) + 1466 /* IFLA_GRE_IGNORE_DF */ 1467 nla_total_size(1) + 1468 /* IFLA_GRE_FWMARK */ 1469 nla_total_size(4) + 1470 /* IFLA_GRE_ERSPAN_INDEX */ 1471 nla_total_size(4) + 1472 /* IFLA_GRE_ERSPAN_VER */ 1473 nla_total_size(1) + 1474 /* IFLA_GRE_ERSPAN_DIR */ 1475 nla_total_size(1) + 1476 /* IFLA_GRE_ERSPAN_HWID */ 1477 nla_total_size(2) + 1478 0; 1479 } 1480 1481 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev) 1482 { 1483 struct ip_tunnel *t = netdev_priv(dev); 1484 struct ip_tunnel_parm *p = &t->parms; 1485 __be16 o_flags = p->o_flags; 1486 1487 if (t->erspan_ver <= 2) { 1488 if (t->erspan_ver != 0 && !t->collect_md) 1489 o_flags |= TUNNEL_KEY; 1490 1491 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, t->erspan_ver)) 1492 goto nla_put_failure; 1493 1494 if (t->erspan_ver == 1) { 1495 if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, t->index)) 1496 goto nla_put_failure; 1497 } else if (t->erspan_ver == 2) { 1498 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, t->dir)) 1499 goto nla_put_failure; 1500 if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, t->hwid)) 1501 goto nla_put_failure; 1502 } 1503 } 1504 1505 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) || 1506 nla_put_be16(skb, IFLA_GRE_IFLAGS, 1507 gre_tnl_flags_to_gre_flags(p->i_flags)) || 1508 nla_put_be16(skb, IFLA_GRE_OFLAGS, 1509 gre_tnl_flags_to_gre_flags(o_flags)) || 1510 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) || 1511 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) || 1512 nla_put_in_addr(skb, IFLA_GRE_LOCAL, p->iph.saddr) || 1513 nla_put_in_addr(skb, IFLA_GRE_REMOTE, p->iph.daddr) || 1514 nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) || 1515 nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) || 1516 nla_put_u8(skb, IFLA_GRE_PMTUDISC, 1517 !!(p->iph.frag_off & htons(IP_DF))) || 1518 nla_put_u32(skb, IFLA_GRE_FWMARK, t->fwmark)) 1519 goto nla_put_failure; 1520 1521 if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE, 1522 t->encap.type) || 1523 nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT, 1524 t->encap.sport) || 1525 nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT, 1526 t->encap.dport) || 1527 nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS, 1528 t->encap.flags)) 1529 goto nla_put_failure; 1530 1531 if (nla_put_u8(skb, IFLA_GRE_IGNORE_DF, t->ignore_df)) 1532 goto nla_put_failure; 1533 1534 if (t->collect_md) { 1535 if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA)) 1536 goto nla_put_failure; 1537 } 1538 1539 return 0; 1540 1541 nla_put_failure: 1542 return -EMSGSIZE; 1543 } 1544 1545 static void erspan_setup(struct net_device *dev) 1546 { 1547 struct ip_tunnel *t = netdev_priv(dev); 1548 1549 ether_setup(dev); 1550 dev->max_mtu = 0; 1551 dev->netdev_ops = &erspan_netdev_ops; 1552 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 1553 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1554 ip_tunnel_setup(dev, erspan_net_id); 1555 t->erspan_ver = 1; 1556 } 1557 1558 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = { 1559 [IFLA_GRE_LINK] = { .type = NLA_U32 }, 1560 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 }, 1561 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 }, 1562 [IFLA_GRE_IKEY] = { .type = NLA_U32 }, 1563 [IFLA_GRE_OKEY] = { .type = NLA_U32 }, 1564 [IFLA_GRE_LOCAL] = { .len = sizeof_field(struct iphdr, saddr) }, 1565 [IFLA_GRE_REMOTE] = { .len = sizeof_field(struct iphdr, daddr) }, 1566 [IFLA_GRE_TTL] = { .type = NLA_U8 }, 1567 [IFLA_GRE_TOS] = { .type = NLA_U8 }, 1568 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 }, 1569 [IFLA_GRE_ENCAP_TYPE] = { .type = NLA_U16 }, 1570 [IFLA_GRE_ENCAP_FLAGS] = { .type = NLA_U16 }, 1571 [IFLA_GRE_ENCAP_SPORT] = { .type = NLA_U16 }, 1572 [IFLA_GRE_ENCAP_DPORT] = { .type = NLA_U16 }, 1573 [IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG }, 1574 [IFLA_GRE_IGNORE_DF] = { .type = NLA_U8 }, 1575 [IFLA_GRE_FWMARK] = { .type = NLA_U32 }, 1576 [IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 }, 1577 [IFLA_GRE_ERSPAN_VER] = { .type = NLA_U8 }, 1578 [IFLA_GRE_ERSPAN_DIR] = { .type = NLA_U8 }, 1579 [IFLA_GRE_ERSPAN_HWID] = { .type = NLA_U16 }, 1580 }; 1581 1582 static struct rtnl_link_ops ipgre_link_ops __read_mostly = { 1583 .kind = "gre", 1584 .maxtype = IFLA_GRE_MAX, 1585 .policy = ipgre_policy, 1586 .priv_size = sizeof(struct ip_tunnel), 1587 .setup = ipgre_tunnel_setup, 1588 .validate = ipgre_tunnel_validate, 1589 .newlink = ipgre_newlink, 1590 .changelink = ipgre_changelink, 1591 .dellink = ip_tunnel_dellink, 1592 .get_size = ipgre_get_size, 1593 .fill_info = ipgre_fill_info, 1594 .get_link_net = ip_tunnel_get_link_net, 1595 }; 1596 1597 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = { 1598 .kind = "gretap", 1599 .maxtype = IFLA_GRE_MAX, 1600 .policy = ipgre_policy, 1601 .priv_size = sizeof(struct ip_tunnel), 1602 .setup = ipgre_tap_setup, 1603 .validate = ipgre_tap_validate, 1604 .newlink = ipgre_newlink, 1605 .changelink = ipgre_changelink, 1606 .dellink = ip_tunnel_dellink, 1607 .get_size = ipgre_get_size, 1608 .fill_info = ipgre_fill_info, 1609 .get_link_net = ip_tunnel_get_link_net, 1610 }; 1611 1612 static struct rtnl_link_ops erspan_link_ops __read_mostly = { 1613 .kind = "erspan", 1614 .maxtype = IFLA_GRE_MAX, 1615 .policy = ipgre_policy, 1616 .priv_size = sizeof(struct ip_tunnel), 1617 .setup = erspan_setup, 1618 .validate = erspan_validate, 1619 .newlink = erspan_newlink, 1620 .changelink = erspan_changelink, 1621 .dellink = ip_tunnel_dellink, 1622 .get_size = ipgre_get_size, 1623 .fill_info = ipgre_fill_info, 1624 .get_link_net = ip_tunnel_get_link_net, 1625 }; 1626 1627 struct net_device *gretap_fb_dev_create(struct net *net, const char *name, 1628 u8 name_assign_type) 1629 { 1630 struct nlattr *tb[IFLA_MAX + 1]; 1631 struct net_device *dev; 1632 LIST_HEAD(list_kill); 1633 struct ip_tunnel *t; 1634 int err; 1635 1636 memset(&tb, 0, sizeof(tb)); 1637 1638 dev = rtnl_create_link(net, name, name_assign_type, 1639 &ipgre_tap_ops, tb, NULL); 1640 if (IS_ERR(dev)) 1641 return dev; 1642 1643 /* Configure flow based GRE device. */ 1644 t = netdev_priv(dev); 1645 t->collect_md = true; 1646 1647 err = ipgre_newlink(net, dev, tb, NULL, NULL); 1648 if (err < 0) { 1649 free_netdev(dev); 1650 return ERR_PTR(err); 1651 } 1652 1653 /* openvswitch users expect packet sizes to be unrestricted, 1654 * so set the largest MTU we can. 1655 */ 1656 err = __ip_tunnel_change_mtu(dev, IP_MAX_MTU, false); 1657 if (err) 1658 goto out; 1659 1660 err = rtnl_configure_link(dev, NULL); 1661 if (err < 0) 1662 goto out; 1663 1664 return dev; 1665 out: 1666 ip_tunnel_dellink(dev, &list_kill); 1667 unregister_netdevice_many(&list_kill); 1668 return ERR_PTR(err); 1669 } 1670 EXPORT_SYMBOL_GPL(gretap_fb_dev_create); 1671 1672 static int __net_init ipgre_tap_init_net(struct net *net) 1673 { 1674 return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, "gretap0"); 1675 } 1676 1677 static void __net_exit ipgre_tap_exit_batch_net(struct list_head *list_net) 1678 { 1679 ip_tunnel_delete_nets(list_net, gre_tap_net_id, &ipgre_tap_ops); 1680 } 1681 1682 static struct pernet_operations ipgre_tap_net_ops = { 1683 .init = ipgre_tap_init_net, 1684 .exit_batch = ipgre_tap_exit_batch_net, 1685 .id = &gre_tap_net_id, 1686 .size = sizeof(struct ip_tunnel_net), 1687 }; 1688 1689 static int __net_init erspan_init_net(struct net *net) 1690 { 1691 return ip_tunnel_init_net(net, erspan_net_id, 1692 &erspan_link_ops, "erspan0"); 1693 } 1694 1695 static void __net_exit erspan_exit_batch_net(struct list_head *net_list) 1696 { 1697 ip_tunnel_delete_nets(net_list, erspan_net_id, &erspan_link_ops); 1698 } 1699 1700 static struct pernet_operations erspan_net_ops = { 1701 .init = erspan_init_net, 1702 .exit_batch = erspan_exit_batch_net, 1703 .id = &erspan_net_id, 1704 .size = sizeof(struct ip_tunnel_net), 1705 }; 1706 1707 static int __init ipgre_init(void) 1708 { 1709 int err; 1710 1711 pr_info("GRE over IPv4 tunneling driver\n"); 1712 1713 err = register_pernet_device(&ipgre_net_ops); 1714 if (err < 0) 1715 return err; 1716 1717 err = register_pernet_device(&ipgre_tap_net_ops); 1718 if (err < 0) 1719 goto pnet_tap_failed; 1720 1721 err = register_pernet_device(&erspan_net_ops); 1722 if (err < 0) 1723 goto pnet_erspan_failed; 1724 1725 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO); 1726 if (err < 0) { 1727 pr_info("%s: can't add protocol\n", __func__); 1728 goto add_proto_failed; 1729 } 1730 1731 err = rtnl_link_register(&ipgre_link_ops); 1732 if (err < 0) 1733 goto rtnl_link_failed; 1734 1735 err = rtnl_link_register(&ipgre_tap_ops); 1736 if (err < 0) 1737 goto tap_ops_failed; 1738 1739 err = rtnl_link_register(&erspan_link_ops); 1740 if (err < 0) 1741 goto erspan_link_failed; 1742 1743 return 0; 1744 1745 erspan_link_failed: 1746 rtnl_link_unregister(&ipgre_tap_ops); 1747 tap_ops_failed: 1748 rtnl_link_unregister(&ipgre_link_ops); 1749 rtnl_link_failed: 1750 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); 1751 add_proto_failed: 1752 unregister_pernet_device(&erspan_net_ops); 1753 pnet_erspan_failed: 1754 unregister_pernet_device(&ipgre_tap_net_ops); 1755 pnet_tap_failed: 1756 unregister_pernet_device(&ipgre_net_ops); 1757 return err; 1758 } 1759 1760 static void __exit ipgre_fini(void) 1761 { 1762 rtnl_link_unregister(&ipgre_tap_ops); 1763 rtnl_link_unregister(&ipgre_link_ops); 1764 rtnl_link_unregister(&erspan_link_ops); 1765 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); 1766 unregister_pernet_device(&ipgre_tap_net_ops); 1767 unregister_pernet_device(&ipgre_net_ops); 1768 unregister_pernet_device(&erspan_net_ops); 1769 } 1770 1771 module_init(ipgre_init); 1772 module_exit(ipgre_fini); 1773 MODULE_LICENSE("GPL"); 1774 MODULE_ALIAS_RTNL_LINK("gre"); 1775 MODULE_ALIAS_RTNL_LINK("gretap"); 1776 MODULE_ALIAS_RTNL_LINK("erspan"); 1777 MODULE_ALIAS_NETDEV("gre0"); 1778 MODULE_ALIAS_NETDEV("gretap0"); 1779 MODULE_ALIAS_NETDEV("erspan0"); 1780