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_INC(dev, 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; 527 528 tun_info = skb_tunnel_info(skb); 529 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) || 530 ip_tunnel_info_af(tun_info) != AF_INET)) 531 goto err_free_skb; 532 533 key = &tun_info->key; 534 if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT)) 535 goto err_free_skb; 536 if (tun_info->options_len < sizeof(*md)) 537 goto err_free_skb; 538 md = ip_tunnel_info_opts(tun_info); 539 540 /* ERSPAN has fixed 8 byte GRE header */ 541 version = md->version; 542 tunnel_hlen = 8 + erspan_hdr_len(version); 543 544 if (skb_cow_head(skb, dev->needed_headroom)) 545 goto err_free_skb; 546 547 if (gre_handle_offloads(skb, false)) 548 goto err_free_skb; 549 550 if (skb->len > dev->mtu + dev->hard_header_len) { 551 pskb_trim(skb, dev->mtu + dev->hard_header_len); 552 truncate = true; 553 } 554 555 nhoff = skb_network_header(skb) - skb_mac_header(skb); 556 if (skb->protocol == htons(ETH_P_IP) && 557 (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff)) 558 truncate = true; 559 560 if (skb->protocol == htons(ETH_P_IPV6)) { 561 int thoff; 562 563 if (skb_transport_header_was_set(skb)) 564 thoff = skb_transport_header(skb) - skb_mac_header(skb); 565 else 566 thoff = nhoff + sizeof(struct ipv6hdr); 567 if (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff) 568 truncate = true; 569 } 570 571 if (version == 1) { 572 erspan_build_header(skb, ntohl(tunnel_id_to_key32(key->tun_id)), 573 ntohl(md->u.index), truncate, true); 574 proto = htons(ETH_P_ERSPAN); 575 } else if (version == 2) { 576 erspan_build_header_v2(skb, 577 ntohl(tunnel_id_to_key32(key->tun_id)), 578 md->u.md2.dir, 579 get_hwid(&md->u.md2), 580 truncate, true); 581 proto = htons(ETH_P_ERSPAN2); 582 } else { 583 goto err_free_skb; 584 } 585 586 gre_build_header(skb, 8, TUNNEL_SEQ, 587 proto, 0, htonl(atomic_fetch_inc(&tunnel->o_seqno))); 588 589 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen); 590 591 return; 592 593 err_free_skb: 594 kfree_skb(skb); 595 DEV_STATS_INC(dev, tx_dropped); 596 } 597 598 static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb) 599 { 600 struct ip_tunnel_info *info = skb_tunnel_info(skb); 601 const struct ip_tunnel_key *key; 602 struct rtable *rt; 603 struct flowi4 fl4; 604 605 if (ip_tunnel_info_af(info) != AF_INET) 606 return -EINVAL; 607 608 key = &info->key; 609 ip_tunnel_init_flow(&fl4, IPPROTO_GRE, key->u.ipv4.dst, key->u.ipv4.src, 610 tunnel_id_to_key32(key->tun_id), 611 key->tos & ~INET_ECN_MASK, dev_net(dev), 0, 612 skb->mark, skb_get_hash(skb), key->flow_flags); 613 rt = ip_route_output_key(dev_net(dev), &fl4); 614 if (IS_ERR(rt)) 615 return PTR_ERR(rt); 616 617 ip_rt_put(rt); 618 info->key.u.ipv4.src = fl4.saddr; 619 return 0; 620 } 621 622 static netdev_tx_t ipgre_xmit(struct sk_buff *skb, 623 struct net_device *dev) 624 { 625 struct ip_tunnel *tunnel = netdev_priv(dev); 626 const struct iphdr *tnl_params; 627 628 if (!pskb_inet_may_pull(skb)) 629 goto free_skb; 630 631 if (tunnel->collect_md) { 632 gre_fb_xmit(skb, dev, skb->protocol); 633 return NETDEV_TX_OK; 634 } 635 636 if (dev->header_ops) { 637 if (skb_cow_head(skb, 0)) 638 goto free_skb; 639 640 tnl_params = (const struct iphdr *)skb->data; 641 642 /* Pull skb since ip_tunnel_xmit() needs skb->data pointing 643 * to gre header. 644 */ 645 skb_pull(skb, tunnel->hlen + sizeof(struct iphdr)); 646 skb_reset_mac_header(skb); 647 648 if (skb->ip_summed == CHECKSUM_PARTIAL && 649 skb_checksum_start(skb) < skb->data) 650 goto free_skb; 651 } else { 652 if (skb_cow_head(skb, dev->needed_headroom)) 653 goto free_skb; 654 655 tnl_params = &tunnel->parms.iph; 656 } 657 658 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM))) 659 goto free_skb; 660 661 __gre_xmit(skb, dev, tnl_params, skb->protocol); 662 return NETDEV_TX_OK; 663 664 free_skb: 665 kfree_skb(skb); 666 DEV_STATS_INC(dev, tx_dropped); 667 return NETDEV_TX_OK; 668 } 669 670 static netdev_tx_t erspan_xmit(struct sk_buff *skb, 671 struct net_device *dev) 672 { 673 struct ip_tunnel *tunnel = netdev_priv(dev); 674 bool truncate = false; 675 __be16 proto; 676 677 if (!pskb_inet_may_pull(skb)) 678 goto free_skb; 679 680 if (tunnel->collect_md) { 681 erspan_fb_xmit(skb, dev); 682 return NETDEV_TX_OK; 683 } 684 685 if (gre_handle_offloads(skb, false)) 686 goto free_skb; 687 688 if (skb_cow_head(skb, dev->needed_headroom)) 689 goto free_skb; 690 691 if (skb->len > dev->mtu + dev->hard_header_len) { 692 pskb_trim(skb, dev->mtu + dev->hard_header_len); 693 truncate = true; 694 } 695 696 /* Push ERSPAN header */ 697 if (tunnel->erspan_ver == 0) { 698 proto = htons(ETH_P_ERSPAN); 699 tunnel->parms.o_flags &= ~TUNNEL_SEQ; 700 } else if (tunnel->erspan_ver == 1) { 701 erspan_build_header(skb, ntohl(tunnel->parms.o_key), 702 tunnel->index, 703 truncate, true); 704 proto = htons(ETH_P_ERSPAN); 705 } else if (tunnel->erspan_ver == 2) { 706 erspan_build_header_v2(skb, ntohl(tunnel->parms.o_key), 707 tunnel->dir, tunnel->hwid, 708 truncate, true); 709 proto = htons(ETH_P_ERSPAN2); 710 } else { 711 goto free_skb; 712 } 713 714 tunnel->parms.o_flags &= ~TUNNEL_KEY; 715 __gre_xmit(skb, dev, &tunnel->parms.iph, proto); 716 return NETDEV_TX_OK; 717 718 free_skb: 719 kfree_skb(skb); 720 DEV_STATS_INC(dev, tx_dropped); 721 return NETDEV_TX_OK; 722 } 723 724 static netdev_tx_t gre_tap_xmit(struct sk_buff *skb, 725 struct net_device *dev) 726 { 727 struct ip_tunnel *tunnel = netdev_priv(dev); 728 729 if (!pskb_inet_may_pull(skb)) 730 goto free_skb; 731 732 if (tunnel->collect_md) { 733 gre_fb_xmit(skb, dev, htons(ETH_P_TEB)); 734 return NETDEV_TX_OK; 735 } 736 737 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM))) 738 goto free_skb; 739 740 if (skb_cow_head(skb, dev->needed_headroom)) 741 goto free_skb; 742 743 __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB)); 744 return NETDEV_TX_OK; 745 746 free_skb: 747 kfree_skb(skb); 748 DEV_STATS_INC(dev, tx_dropped); 749 return NETDEV_TX_OK; 750 } 751 752 static void ipgre_link_update(struct net_device *dev, bool set_mtu) 753 { 754 struct ip_tunnel *tunnel = netdev_priv(dev); 755 __be16 flags; 756 int len; 757 758 len = tunnel->tun_hlen; 759 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags); 760 len = tunnel->tun_hlen - len; 761 tunnel->hlen = tunnel->hlen + len; 762 763 if (dev->header_ops) 764 dev->hard_header_len += len; 765 else 766 dev->needed_headroom += len; 767 768 if (set_mtu) 769 dev->mtu = max_t(int, dev->mtu - len, 68); 770 771 flags = tunnel->parms.o_flags; 772 773 if (flags & TUNNEL_SEQ || 774 (flags & TUNNEL_CSUM && tunnel->encap.type != TUNNEL_ENCAP_NONE)) { 775 dev->features &= ~NETIF_F_GSO_SOFTWARE; 776 dev->hw_features &= ~NETIF_F_GSO_SOFTWARE; 777 } else { 778 dev->features |= NETIF_F_GSO_SOFTWARE; 779 dev->hw_features |= NETIF_F_GSO_SOFTWARE; 780 } 781 } 782 783 static int ipgre_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, 784 int cmd) 785 { 786 int err; 787 788 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) { 789 if (p->iph.version != 4 || p->iph.protocol != IPPROTO_GRE || 790 p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)) || 791 ((p->i_flags | p->o_flags) & (GRE_VERSION | GRE_ROUTING))) 792 return -EINVAL; 793 } 794 795 p->i_flags = gre_flags_to_tnl_flags(p->i_flags); 796 p->o_flags = gre_flags_to_tnl_flags(p->o_flags); 797 798 err = ip_tunnel_ctl(dev, p, cmd); 799 if (err) 800 return err; 801 802 if (cmd == SIOCCHGTUNNEL) { 803 struct ip_tunnel *t = netdev_priv(dev); 804 805 t->parms.i_flags = p->i_flags; 806 t->parms.o_flags = p->o_flags; 807 808 if (strcmp(dev->rtnl_link_ops->kind, "erspan")) 809 ipgre_link_update(dev, true); 810 } 811 812 p->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags); 813 p->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags); 814 return 0; 815 } 816 817 /* Nice toy. Unfortunately, useless in real life :-) 818 It allows to construct virtual multiprotocol broadcast "LAN" 819 over the Internet, provided multicast routing is tuned. 820 821 822 I have no idea was this bicycle invented before me, 823 so that I had to set ARPHRD_IPGRE to a random value. 824 I have an impression, that Cisco could make something similar, 825 but this feature is apparently missing in IOS<=11.2(8). 826 827 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks 828 with broadcast 224.66.66.66. If you have access to mbone, play with me :-) 829 830 ping -t 255 224.66.66.66 831 832 If nobody answers, mbone does not work. 833 834 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255 835 ip addr add 10.66.66.<somewhat>/24 dev Universe 836 ifconfig Universe up 837 ifconfig Universe add fe80::<Your_real_addr>/10 838 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96 839 ftp 10.66.66.66 840 ... 841 ftp fec0:6666:6666::193.233.7.65 842 ... 843 */ 844 static int ipgre_header(struct sk_buff *skb, struct net_device *dev, 845 unsigned short type, 846 const void *daddr, const void *saddr, unsigned int len) 847 { 848 struct ip_tunnel *t = netdev_priv(dev); 849 struct iphdr *iph; 850 struct gre_base_hdr *greh; 851 852 iph = skb_push(skb, t->hlen + sizeof(*iph)); 853 greh = (struct gre_base_hdr *)(iph+1); 854 greh->flags = gre_tnl_flags_to_gre_flags(t->parms.o_flags); 855 greh->protocol = htons(type); 856 857 memcpy(iph, &t->parms.iph, sizeof(struct iphdr)); 858 859 /* Set the source hardware address. */ 860 if (saddr) 861 memcpy(&iph->saddr, saddr, 4); 862 if (daddr) 863 memcpy(&iph->daddr, daddr, 4); 864 if (iph->daddr) 865 return t->hlen + sizeof(*iph); 866 867 return -(t->hlen + sizeof(*iph)); 868 } 869 870 static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr) 871 { 872 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb); 873 memcpy(haddr, &iph->saddr, 4); 874 return 4; 875 } 876 877 static const struct header_ops ipgre_header_ops = { 878 .create = ipgre_header, 879 .parse = ipgre_header_parse, 880 }; 881 882 #ifdef CONFIG_NET_IPGRE_BROADCAST 883 static int ipgre_open(struct net_device *dev) 884 { 885 struct ip_tunnel *t = netdev_priv(dev); 886 887 if (ipv4_is_multicast(t->parms.iph.daddr)) { 888 struct flowi4 fl4; 889 struct rtable *rt; 890 891 rt = ip_route_output_gre(t->net, &fl4, 892 t->parms.iph.daddr, 893 t->parms.iph.saddr, 894 t->parms.o_key, 895 RT_TOS(t->parms.iph.tos), 896 t->parms.link); 897 if (IS_ERR(rt)) 898 return -EADDRNOTAVAIL; 899 dev = rt->dst.dev; 900 ip_rt_put(rt); 901 if (!__in_dev_get_rtnl(dev)) 902 return -EADDRNOTAVAIL; 903 t->mlink = dev->ifindex; 904 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr); 905 } 906 return 0; 907 } 908 909 static int ipgre_close(struct net_device *dev) 910 { 911 struct ip_tunnel *t = netdev_priv(dev); 912 913 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) { 914 struct in_device *in_dev; 915 in_dev = inetdev_by_index(t->net, t->mlink); 916 if (in_dev) 917 ip_mc_dec_group(in_dev, t->parms.iph.daddr); 918 } 919 return 0; 920 } 921 #endif 922 923 static const struct net_device_ops ipgre_netdev_ops = { 924 .ndo_init = ipgre_tunnel_init, 925 .ndo_uninit = ip_tunnel_uninit, 926 #ifdef CONFIG_NET_IPGRE_BROADCAST 927 .ndo_open = ipgre_open, 928 .ndo_stop = ipgre_close, 929 #endif 930 .ndo_start_xmit = ipgre_xmit, 931 .ndo_siocdevprivate = ip_tunnel_siocdevprivate, 932 .ndo_change_mtu = ip_tunnel_change_mtu, 933 .ndo_get_stats64 = dev_get_tstats64, 934 .ndo_get_iflink = ip_tunnel_get_iflink, 935 .ndo_tunnel_ctl = ipgre_tunnel_ctl, 936 }; 937 938 #define GRE_FEATURES (NETIF_F_SG | \ 939 NETIF_F_FRAGLIST | \ 940 NETIF_F_HIGHDMA | \ 941 NETIF_F_HW_CSUM) 942 943 static void ipgre_tunnel_setup(struct net_device *dev) 944 { 945 dev->netdev_ops = &ipgre_netdev_ops; 946 dev->type = ARPHRD_IPGRE; 947 ip_tunnel_setup(dev, ipgre_net_id); 948 } 949 950 static void __gre_tunnel_init(struct net_device *dev) 951 { 952 struct ip_tunnel *tunnel; 953 __be16 flags; 954 955 tunnel = netdev_priv(dev); 956 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags); 957 tunnel->parms.iph.protocol = IPPROTO_GRE; 958 959 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen; 960 dev->needed_headroom = tunnel->hlen + sizeof(tunnel->parms.iph); 961 962 dev->features |= GRE_FEATURES | NETIF_F_LLTX; 963 dev->hw_features |= GRE_FEATURES; 964 965 flags = tunnel->parms.o_flags; 966 967 /* TCP offload with GRE SEQ is not supported, nor can we support 2 968 * levels of outer headers requiring an update. 969 */ 970 if (flags & TUNNEL_SEQ) 971 return; 972 if (flags & TUNNEL_CSUM && tunnel->encap.type != TUNNEL_ENCAP_NONE) 973 return; 974 975 dev->features |= NETIF_F_GSO_SOFTWARE; 976 dev->hw_features |= NETIF_F_GSO_SOFTWARE; 977 } 978 979 static int ipgre_tunnel_init(struct net_device *dev) 980 { 981 struct ip_tunnel *tunnel = netdev_priv(dev); 982 struct iphdr *iph = &tunnel->parms.iph; 983 984 __gre_tunnel_init(dev); 985 986 __dev_addr_set(dev, &iph->saddr, 4); 987 memcpy(dev->broadcast, &iph->daddr, 4); 988 989 dev->flags = IFF_NOARP; 990 netif_keep_dst(dev); 991 dev->addr_len = 4; 992 993 if (iph->daddr && !tunnel->collect_md) { 994 #ifdef CONFIG_NET_IPGRE_BROADCAST 995 if (ipv4_is_multicast(iph->daddr)) { 996 if (!iph->saddr) 997 return -EINVAL; 998 dev->flags = IFF_BROADCAST; 999 dev->header_ops = &ipgre_header_ops; 1000 dev->hard_header_len = tunnel->hlen + sizeof(*iph); 1001 dev->needed_headroom = 0; 1002 } 1003 #endif 1004 } else if (!tunnel->collect_md) { 1005 dev->header_ops = &ipgre_header_ops; 1006 dev->hard_header_len = tunnel->hlen + sizeof(*iph); 1007 dev->needed_headroom = 0; 1008 } 1009 1010 return ip_tunnel_init(dev); 1011 } 1012 1013 static const struct gre_protocol ipgre_protocol = { 1014 .handler = gre_rcv, 1015 .err_handler = gre_err, 1016 }; 1017 1018 static int __net_init ipgre_init_net(struct net *net) 1019 { 1020 return ip_tunnel_init_net(net, ipgre_net_id, &ipgre_link_ops, NULL); 1021 } 1022 1023 static void __net_exit ipgre_exit_batch_net(struct list_head *list_net) 1024 { 1025 ip_tunnel_delete_nets(list_net, ipgre_net_id, &ipgre_link_ops); 1026 } 1027 1028 static struct pernet_operations ipgre_net_ops = { 1029 .init = ipgre_init_net, 1030 .exit_batch = ipgre_exit_batch_net, 1031 .id = &ipgre_net_id, 1032 .size = sizeof(struct ip_tunnel_net), 1033 }; 1034 1035 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[], 1036 struct netlink_ext_ack *extack) 1037 { 1038 __be16 flags; 1039 1040 if (!data) 1041 return 0; 1042 1043 flags = 0; 1044 if (data[IFLA_GRE_IFLAGS]) 1045 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); 1046 if (data[IFLA_GRE_OFLAGS]) 1047 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); 1048 if (flags & (GRE_VERSION|GRE_ROUTING)) 1049 return -EINVAL; 1050 1051 if (data[IFLA_GRE_COLLECT_METADATA] && 1052 data[IFLA_GRE_ENCAP_TYPE] && 1053 nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]) != TUNNEL_ENCAP_NONE) 1054 return -EINVAL; 1055 1056 return 0; 1057 } 1058 1059 static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[], 1060 struct netlink_ext_ack *extack) 1061 { 1062 __be32 daddr; 1063 1064 if (tb[IFLA_ADDRESS]) { 1065 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) 1066 return -EINVAL; 1067 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) 1068 return -EADDRNOTAVAIL; 1069 } 1070 1071 if (!data) 1072 goto out; 1073 1074 if (data[IFLA_GRE_REMOTE]) { 1075 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4); 1076 if (!daddr) 1077 return -EINVAL; 1078 } 1079 1080 out: 1081 return ipgre_tunnel_validate(tb, data, extack); 1082 } 1083 1084 static int erspan_validate(struct nlattr *tb[], struct nlattr *data[], 1085 struct netlink_ext_ack *extack) 1086 { 1087 __be16 flags = 0; 1088 int ret; 1089 1090 if (!data) 1091 return 0; 1092 1093 ret = ipgre_tap_validate(tb, data, extack); 1094 if (ret) 1095 return ret; 1096 1097 if (data[IFLA_GRE_ERSPAN_VER] && 1098 nla_get_u8(data[IFLA_GRE_ERSPAN_VER]) == 0) 1099 return 0; 1100 1101 /* ERSPAN type II/III should only have GRE sequence and key flag */ 1102 if (data[IFLA_GRE_OFLAGS]) 1103 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); 1104 if (data[IFLA_GRE_IFLAGS]) 1105 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); 1106 if (!data[IFLA_GRE_COLLECT_METADATA] && 1107 flags != (GRE_SEQ | GRE_KEY)) 1108 return -EINVAL; 1109 1110 /* ERSPAN Session ID only has 10-bit. Since we reuse 1111 * 32-bit key field as ID, check it's range. 1112 */ 1113 if (data[IFLA_GRE_IKEY] && 1114 (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK)) 1115 return -EINVAL; 1116 1117 if (data[IFLA_GRE_OKEY] && 1118 (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK)) 1119 return -EINVAL; 1120 1121 return 0; 1122 } 1123 1124 static int ipgre_netlink_parms(struct net_device *dev, 1125 struct nlattr *data[], 1126 struct nlattr *tb[], 1127 struct ip_tunnel_parm *parms, 1128 __u32 *fwmark) 1129 { 1130 struct ip_tunnel *t = netdev_priv(dev); 1131 1132 memset(parms, 0, sizeof(*parms)); 1133 1134 parms->iph.protocol = IPPROTO_GRE; 1135 1136 if (!data) 1137 return 0; 1138 1139 if (data[IFLA_GRE_LINK]) 1140 parms->link = nla_get_u32(data[IFLA_GRE_LINK]); 1141 1142 if (data[IFLA_GRE_IFLAGS]) 1143 parms->i_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_IFLAGS])); 1144 1145 if (data[IFLA_GRE_OFLAGS]) 1146 parms->o_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_OFLAGS])); 1147 1148 if (data[IFLA_GRE_IKEY]) 1149 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]); 1150 1151 if (data[IFLA_GRE_OKEY]) 1152 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]); 1153 1154 if (data[IFLA_GRE_LOCAL]) 1155 parms->iph.saddr = nla_get_in_addr(data[IFLA_GRE_LOCAL]); 1156 1157 if (data[IFLA_GRE_REMOTE]) 1158 parms->iph.daddr = nla_get_in_addr(data[IFLA_GRE_REMOTE]); 1159 1160 if (data[IFLA_GRE_TTL]) 1161 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]); 1162 1163 if (data[IFLA_GRE_TOS]) 1164 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]); 1165 1166 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC])) { 1167 if (t->ignore_df) 1168 return -EINVAL; 1169 parms->iph.frag_off = htons(IP_DF); 1170 } 1171 1172 if (data[IFLA_GRE_COLLECT_METADATA]) { 1173 t->collect_md = true; 1174 if (dev->type == ARPHRD_IPGRE) 1175 dev->type = ARPHRD_NONE; 1176 } 1177 1178 if (data[IFLA_GRE_IGNORE_DF]) { 1179 if (nla_get_u8(data[IFLA_GRE_IGNORE_DF]) 1180 && (parms->iph.frag_off & htons(IP_DF))) 1181 return -EINVAL; 1182 t->ignore_df = !!nla_get_u8(data[IFLA_GRE_IGNORE_DF]); 1183 } 1184 1185 if (data[IFLA_GRE_FWMARK]) 1186 *fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]); 1187 1188 return 0; 1189 } 1190 1191 static int erspan_netlink_parms(struct net_device *dev, 1192 struct nlattr *data[], 1193 struct nlattr *tb[], 1194 struct ip_tunnel_parm *parms, 1195 __u32 *fwmark) 1196 { 1197 struct ip_tunnel *t = netdev_priv(dev); 1198 int err; 1199 1200 err = ipgre_netlink_parms(dev, data, tb, parms, fwmark); 1201 if (err) 1202 return err; 1203 if (!data) 1204 return 0; 1205 1206 if (data[IFLA_GRE_ERSPAN_VER]) { 1207 t->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]); 1208 1209 if (t->erspan_ver > 2) 1210 return -EINVAL; 1211 } 1212 1213 if (t->erspan_ver == 1) { 1214 if (data[IFLA_GRE_ERSPAN_INDEX]) { 1215 t->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]); 1216 if (t->index & ~INDEX_MASK) 1217 return -EINVAL; 1218 } 1219 } else if (t->erspan_ver == 2) { 1220 if (data[IFLA_GRE_ERSPAN_DIR]) { 1221 t->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]); 1222 if (t->dir & ~(DIR_MASK >> DIR_OFFSET)) 1223 return -EINVAL; 1224 } 1225 if (data[IFLA_GRE_ERSPAN_HWID]) { 1226 t->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]); 1227 if (t->hwid & ~(HWID_MASK >> HWID_OFFSET)) 1228 return -EINVAL; 1229 } 1230 } 1231 1232 return 0; 1233 } 1234 1235 /* This function returns true when ENCAP attributes are present in the nl msg */ 1236 static bool ipgre_netlink_encap_parms(struct nlattr *data[], 1237 struct ip_tunnel_encap *ipencap) 1238 { 1239 bool ret = false; 1240 1241 memset(ipencap, 0, sizeof(*ipencap)); 1242 1243 if (!data) 1244 return ret; 1245 1246 if (data[IFLA_GRE_ENCAP_TYPE]) { 1247 ret = true; 1248 ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]); 1249 } 1250 1251 if (data[IFLA_GRE_ENCAP_FLAGS]) { 1252 ret = true; 1253 ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]); 1254 } 1255 1256 if (data[IFLA_GRE_ENCAP_SPORT]) { 1257 ret = true; 1258 ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]); 1259 } 1260 1261 if (data[IFLA_GRE_ENCAP_DPORT]) { 1262 ret = true; 1263 ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]); 1264 } 1265 1266 return ret; 1267 } 1268 1269 static int gre_tap_init(struct net_device *dev) 1270 { 1271 __gre_tunnel_init(dev); 1272 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1273 netif_keep_dst(dev); 1274 1275 return ip_tunnel_init(dev); 1276 } 1277 1278 static const struct net_device_ops gre_tap_netdev_ops = { 1279 .ndo_init = gre_tap_init, 1280 .ndo_uninit = ip_tunnel_uninit, 1281 .ndo_start_xmit = gre_tap_xmit, 1282 .ndo_set_mac_address = eth_mac_addr, 1283 .ndo_validate_addr = eth_validate_addr, 1284 .ndo_change_mtu = ip_tunnel_change_mtu, 1285 .ndo_get_stats64 = dev_get_tstats64, 1286 .ndo_get_iflink = ip_tunnel_get_iflink, 1287 .ndo_fill_metadata_dst = gre_fill_metadata_dst, 1288 }; 1289 1290 static int erspan_tunnel_init(struct net_device *dev) 1291 { 1292 struct ip_tunnel *tunnel = netdev_priv(dev); 1293 1294 if (tunnel->erspan_ver == 0) 1295 tunnel->tun_hlen = 4; /* 4-byte GRE hdr. */ 1296 else 1297 tunnel->tun_hlen = 8; /* 8-byte GRE hdr. */ 1298 1299 tunnel->parms.iph.protocol = IPPROTO_GRE; 1300 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen + 1301 erspan_hdr_len(tunnel->erspan_ver); 1302 1303 dev->features |= GRE_FEATURES; 1304 dev->hw_features |= GRE_FEATURES; 1305 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1306 netif_keep_dst(dev); 1307 1308 return ip_tunnel_init(dev); 1309 } 1310 1311 static const struct net_device_ops erspan_netdev_ops = { 1312 .ndo_init = erspan_tunnel_init, 1313 .ndo_uninit = ip_tunnel_uninit, 1314 .ndo_start_xmit = erspan_xmit, 1315 .ndo_set_mac_address = eth_mac_addr, 1316 .ndo_validate_addr = eth_validate_addr, 1317 .ndo_change_mtu = ip_tunnel_change_mtu, 1318 .ndo_get_stats64 = dev_get_tstats64, 1319 .ndo_get_iflink = ip_tunnel_get_iflink, 1320 .ndo_fill_metadata_dst = gre_fill_metadata_dst, 1321 }; 1322 1323 static void ipgre_tap_setup(struct net_device *dev) 1324 { 1325 ether_setup(dev); 1326 dev->max_mtu = 0; 1327 dev->netdev_ops = &gre_tap_netdev_ops; 1328 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 1329 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1330 ip_tunnel_setup(dev, gre_tap_net_id); 1331 } 1332 1333 static int 1334 ipgre_newlink_encap_setup(struct net_device *dev, struct nlattr *data[]) 1335 { 1336 struct ip_tunnel_encap ipencap; 1337 1338 if (ipgre_netlink_encap_parms(data, &ipencap)) { 1339 struct ip_tunnel *t = netdev_priv(dev); 1340 int err = ip_tunnel_encap_setup(t, &ipencap); 1341 1342 if (err < 0) 1343 return err; 1344 } 1345 1346 return 0; 1347 } 1348 1349 static int ipgre_newlink(struct net *src_net, struct net_device *dev, 1350 struct nlattr *tb[], struct nlattr *data[], 1351 struct netlink_ext_ack *extack) 1352 { 1353 struct ip_tunnel_parm p; 1354 __u32 fwmark = 0; 1355 int err; 1356 1357 err = ipgre_newlink_encap_setup(dev, data); 1358 if (err) 1359 return err; 1360 1361 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark); 1362 if (err < 0) 1363 return err; 1364 return ip_tunnel_newlink(dev, tb, &p, fwmark); 1365 } 1366 1367 static int erspan_newlink(struct net *src_net, struct net_device *dev, 1368 struct nlattr *tb[], struct nlattr *data[], 1369 struct netlink_ext_ack *extack) 1370 { 1371 struct ip_tunnel_parm p; 1372 __u32 fwmark = 0; 1373 int err; 1374 1375 err = ipgre_newlink_encap_setup(dev, data); 1376 if (err) 1377 return err; 1378 1379 err = erspan_netlink_parms(dev, data, tb, &p, &fwmark); 1380 if (err) 1381 return err; 1382 return ip_tunnel_newlink(dev, tb, &p, fwmark); 1383 } 1384 1385 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[], 1386 struct nlattr *data[], 1387 struct netlink_ext_ack *extack) 1388 { 1389 struct ip_tunnel *t = netdev_priv(dev); 1390 __u32 fwmark = t->fwmark; 1391 struct ip_tunnel_parm p; 1392 int err; 1393 1394 err = ipgre_newlink_encap_setup(dev, data); 1395 if (err) 1396 return err; 1397 1398 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark); 1399 if (err < 0) 1400 return err; 1401 1402 err = ip_tunnel_changelink(dev, tb, &p, fwmark); 1403 if (err < 0) 1404 return err; 1405 1406 t->parms.i_flags = p.i_flags; 1407 t->parms.o_flags = p.o_flags; 1408 1409 ipgre_link_update(dev, !tb[IFLA_MTU]); 1410 1411 return 0; 1412 } 1413 1414 static int erspan_changelink(struct net_device *dev, struct nlattr *tb[], 1415 struct nlattr *data[], 1416 struct netlink_ext_ack *extack) 1417 { 1418 struct ip_tunnel *t = netdev_priv(dev); 1419 __u32 fwmark = t->fwmark; 1420 struct ip_tunnel_parm p; 1421 int err; 1422 1423 err = ipgre_newlink_encap_setup(dev, data); 1424 if (err) 1425 return err; 1426 1427 err = erspan_netlink_parms(dev, data, tb, &p, &fwmark); 1428 if (err < 0) 1429 return err; 1430 1431 err = ip_tunnel_changelink(dev, tb, &p, fwmark); 1432 if (err < 0) 1433 return err; 1434 1435 t->parms.i_flags = p.i_flags; 1436 t->parms.o_flags = p.o_flags; 1437 1438 return 0; 1439 } 1440 1441 static size_t ipgre_get_size(const struct net_device *dev) 1442 { 1443 return 1444 /* IFLA_GRE_LINK */ 1445 nla_total_size(4) + 1446 /* IFLA_GRE_IFLAGS */ 1447 nla_total_size(2) + 1448 /* IFLA_GRE_OFLAGS */ 1449 nla_total_size(2) + 1450 /* IFLA_GRE_IKEY */ 1451 nla_total_size(4) + 1452 /* IFLA_GRE_OKEY */ 1453 nla_total_size(4) + 1454 /* IFLA_GRE_LOCAL */ 1455 nla_total_size(4) + 1456 /* IFLA_GRE_REMOTE */ 1457 nla_total_size(4) + 1458 /* IFLA_GRE_TTL */ 1459 nla_total_size(1) + 1460 /* IFLA_GRE_TOS */ 1461 nla_total_size(1) + 1462 /* IFLA_GRE_PMTUDISC */ 1463 nla_total_size(1) + 1464 /* IFLA_GRE_ENCAP_TYPE */ 1465 nla_total_size(2) + 1466 /* IFLA_GRE_ENCAP_FLAGS */ 1467 nla_total_size(2) + 1468 /* IFLA_GRE_ENCAP_SPORT */ 1469 nla_total_size(2) + 1470 /* IFLA_GRE_ENCAP_DPORT */ 1471 nla_total_size(2) + 1472 /* IFLA_GRE_COLLECT_METADATA */ 1473 nla_total_size(0) + 1474 /* IFLA_GRE_IGNORE_DF */ 1475 nla_total_size(1) + 1476 /* IFLA_GRE_FWMARK */ 1477 nla_total_size(4) + 1478 /* IFLA_GRE_ERSPAN_INDEX */ 1479 nla_total_size(4) + 1480 /* IFLA_GRE_ERSPAN_VER */ 1481 nla_total_size(1) + 1482 /* IFLA_GRE_ERSPAN_DIR */ 1483 nla_total_size(1) + 1484 /* IFLA_GRE_ERSPAN_HWID */ 1485 nla_total_size(2) + 1486 0; 1487 } 1488 1489 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev) 1490 { 1491 struct ip_tunnel *t = netdev_priv(dev); 1492 struct ip_tunnel_parm *p = &t->parms; 1493 __be16 o_flags = p->o_flags; 1494 1495 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) || 1496 nla_put_be16(skb, IFLA_GRE_IFLAGS, 1497 gre_tnl_flags_to_gre_flags(p->i_flags)) || 1498 nla_put_be16(skb, IFLA_GRE_OFLAGS, 1499 gre_tnl_flags_to_gre_flags(o_flags)) || 1500 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) || 1501 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) || 1502 nla_put_in_addr(skb, IFLA_GRE_LOCAL, p->iph.saddr) || 1503 nla_put_in_addr(skb, IFLA_GRE_REMOTE, p->iph.daddr) || 1504 nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) || 1505 nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) || 1506 nla_put_u8(skb, IFLA_GRE_PMTUDISC, 1507 !!(p->iph.frag_off & htons(IP_DF))) || 1508 nla_put_u32(skb, IFLA_GRE_FWMARK, t->fwmark)) 1509 goto nla_put_failure; 1510 1511 if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE, 1512 t->encap.type) || 1513 nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT, 1514 t->encap.sport) || 1515 nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT, 1516 t->encap.dport) || 1517 nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS, 1518 t->encap.flags)) 1519 goto nla_put_failure; 1520 1521 if (nla_put_u8(skb, IFLA_GRE_IGNORE_DF, t->ignore_df)) 1522 goto nla_put_failure; 1523 1524 if (t->collect_md) { 1525 if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA)) 1526 goto nla_put_failure; 1527 } 1528 1529 return 0; 1530 1531 nla_put_failure: 1532 return -EMSGSIZE; 1533 } 1534 1535 static int erspan_fill_info(struct sk_buff *skb, const struct net_device *dev) 1536 { 1537 struct ip_tunnel *t = netdev_priv(dev); 1538 1539 if (t->erspan_ver <= 2) { 1540 if (t->erspan_ver != 0 && !t->collect_md) 1541 t->parms.o_flags |= TUNNEL_KEY; 1542 1543 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, t->erspan_ver)) 1544 goto nla_put_failure; 1545 1546 if (t->erspan_ver == 1) { 1547 if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, t->index)) 1548 goto nla_put_failure; 1549 } else if (t->erspan_ver == 2) { 1550 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, t->dir)) 1551 goto nla_put_failure; 1552 if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, t->hwid)) 1553 goto nla_put_failure; 1554 } 1555 } 1556 1557 return ipgre_fill_info(skb, dev); 1558 1559 nla_put_failure: 1560 return -EMSGSIZE; 1561 } 1562 1563 static void erspan_setup(struct net_device *dev) 1564 { 1565 struct ip_tunnel *t = netdev_priv(dev); 1566 1567 ether_setup(dev); 1568 dev->max_mtu = 0; 1569 dev->netdev_ops = &erspan_netdev_ops; 1570 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 1571 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1572 ip_tunnel_setup(dev, erspan_net_id); 1573 t->erspan_ver = 1; 1574 } 1575 1576 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = { 1577 [IFLA_GRE_LINK] = { .type = NLA_U32 }, 1578 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 }, 1579 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 }, 1580 [IFLA_GRE_IKEY] = { .type = NLA_U32 }, 1581 [IFLA_GRE_OKEY] = { .type = NLA_U32 }, 1582 [IFLA_GRE_LOCAL] = { .len = sizeof_field(struct iphdr, saddr) }, 1583 [IFLA_GRE_REMOTE] = { .len = sizeof_field(struct iphdr, daddr) }, 1584 [IFLA_GRE_TTL] = { .type = NLA_U8 }, 1585 [IFLA_GRE_TOS] = { .type = NLA_U8 }, 1586 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 }, 1587 [IFLA_GRE_ENCAP_TYPE] = { .type = NLA_U16 }, 1588 [IFLA_GRE_ENCAP_FLAGS] = { .type = NLA_U16 }, 1589 [IFLA_GRE_ENCAP_SPORT] = { .type = NLA_U16 }, 1590 [IFLA_GRE_ENCAP_DPORT] = { .type = NLA_U16 }, 1591 [IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG }, 1592 [IFLA_GRE_IGNORE_DF] = { .type = NLA_U8 }, 1593 [IFLA_GRE_FWMARK] = { .type = NLA_U32 }, 1594 [IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 }, 1595 [IFLA_GRE_ERSPAN_VER] = { .type = NLA_U8 }, 1596 [IFLA_GRE_ERSPAN_DIR] = { .type = NLA_U8 }, 1597 [IFLA_GRE_ERSPAN_HWID] = { .type = NLA_U16 }, 1598 }; 1599 1600 static struct rtnl_link_ops ipgre_link_ops __read_mostly = { 1601 .kind = "gre", 1602 .maxtype = IFLA_GRE_MAX, 1603 .policy = ipgre_policy, 1604 .priv_size = sizeof(struct ip_tunnel), 1605 .setup = ipgre_tunnel_setup, 1606 .validate = ipgre_tunnel_validate, 1607 .newlink = ipgre_newlink, 1608 .changelink = ipgre_changelink, 1609 .dellink = ip_tunnel_dellink, 1610 .get_size = ipgre_get_size, 1611 .fill_info = ipgre_fill_info, 1612 .get_link_net = ip_tunnel_get_link_net, 1613 }; 1614 1615 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = { 1616 .kind = "gretap", 1617 .maxtype = IFLA_GRE_MAX, 1618 .policy = ipgre_policy, 1619 .priv_size = sizeof(struct ip_tunnel), 1620 .setup = ipgre_tap_setup, 1621 .validate = ipgre_tap_validate, 1622 .newlink = ipgre_newlink, 1623 .changelink = ipgre_changelink, 1624 .dellink = ip_tunnel_dellink, 1625 .get_size = ipgre_get_size, 1626 .fill_info = ipgre_fill_info, 1627 .get_link_net = ip_tunnel_get_link_net, 1628 }; 1629 1630 static struct rtnl_link_ops erspan_link_ops __read_mostly = { 1631 .kind = "erspan", 1632 .maxtype = IFLA_GRE_MAX, 1633 .policy = ipgre_policy, 1634 .priv_size = sizeof(struct ip_tunnel), 1635 .setup = erspan_setup, 1636 .validate = erspan_validate, 1637 .newlink = erspan_newlink, 1638 .changelink = erspan_changelink, 1639 .dellink = ip_tunnel_dellink, 1640 .get_size = ipgre_get_size, 1641 .fill_info = erspan_fill_info, 1642 .get_link_net = ip_tunnel_get_link_net, 1643 }; 1644 1645 struct net_device *gretap_fb_dev_create(struct net *net, const char *name, 1646 u8 name_assign_type) 1647 { 1648 struct nlattr *tb[IFLA_MAX + 1]; 1649 struct net_device *dev; 1650 LIST_HEAD(list_kill); 1651 struct ip_tunnel *t; 1652 int err; 1653 1654 memset(&tb, 0, sizeof(tb)); 1655 1656 dev = rtnl_create_link(net, name, name_assign_type, 1657 &ipgre_tap_ops, tb, NULL); 1658 if (IS_ERR(dev)) 1659 return dev; 1660 1661 /* Configure flow based GRE device. */ 1662 t = netdev_priv(dev); 1663 t->collect_md = true; 1664 1665 err = ipgre_newlink(net, dev, tb, NULL, NULL); 1666 if (err < 0) { 1667 free_netdev(dev); 1668 return ERR_PTR(err); 1669 } 1670 1671 /* openvswitch users expect packet sizes to be unrestricted, 1672 * so set the largest MTU we can. 1673 */ 1674 err = __ip_tunnel_change_mtu(dev, IP_MAX_MTU, false); 1675 if (err) 1676 goto out; 1677 1678 err = rtnl_configure_link(dev, NULL, 0, NULL); 1679 if (err < 0) 1680 goto out; 1681 1682 return dev; 1683 out: 1684 ip_tunnel_dellink(dev, &list_kill); 1685 unregister_netdevice_many(&list_kill); 1686 return ERR_PTR(err); 1687 } 1688 EXPORT_SYMBOL_GPL(gretap_fb_dev_create); 1689 1690 static int __net_init ipgre_tap_init_net(struct net *net) 1691 { 1692 return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, "gretap0"); 1693 } 1694 1695 static void __net_exit ipgre_tap_exit_batch_net(struct list_head *list_net) 1696 { 1697 ip_tunnel_delete_nets(list_net, gre_tap_net_id, &ipgre_tap_ops); 1698 } 1699 1700 static struct pernet_operations ipgre_tap_net_ops = { 1701 .init = ipgre_tap_init_net, 1702 .exit_batch = ipgre_tap_exit_batch_net, 1703 .id = &gre_tap_net_id, 1704 .size = sizeof(struct ip_tunnel_net), 1705 }; 1706 1707 static int __net_init erspan_init_net(struct net *net) 1708 { 1709 return ip_tunnel_init_net(net, erspan_net_id, 1710 &erspan_link_ops, "erspan0"); 1711 } 1712 1713 static void __net_exit erspan_exit_batch_net(struct list_head *net_list) 1714 { 1715 ip_tunnel_delete_nets(net_list, erspan_net_id, &erspan_link_ops); 1716 } 1717 1718 static struct pernet_operations erspan_net_ops = { 1719 .init = erspan_init_net, 1720 .exit_batch = erspan_exit_batch_net, 1721 .id = &erspan_net_id, 1722 .size = sizeof(struct ip_tunnel_net), 1723 }; 1724 1725 static int __init ipgre_init(void) 1726 { 1727 int err; 1728 1729 pr_info("GRE over IPv4 tunneling driver\n"); 1730 1731 err = register_pernet_device(&ipgre_net_ops); 1732 if (err < 0) 1733 return err; 1734 1735 err = register_pernet_device(&ipgre_tap_net_ops); 1736 if (err < 0) 1737 goto pnet_tap_failed; 1738 1739 err = register_pernet_device(&erspan_net_ops); 1740 if (err < 0) 1741 goto pnet_erspan_failed; 1742 1743 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO); 1744 if (err < 0) { 1745 pr_info("%s: can't add protocol\n", __func__); 1746 goto add_proto_failed; 1747 } 1748 1749 err = rtnl_link_register(&ipgre_link_ops); 1750 if (err < 0) 1751 goto rtnl_link_failed; 1752 1753 err = rtnl_link_register(&ipgre_tap_ops); 1754 if (err < 0) 1755 goto tap_ops_failed; 1756 1757 err = rtnl_link_register(&erspan_link_ops); 1758 if (err < 0) 1759 goto erspan_link_failed; 1760 1761 return 0; 1762 1763 erspan_link_failed: 1764 rtnl_link_unregister(&ipgre_tap_ops); 1765 tap_ops_failed: 1766 rtnl_link_unregister(&ipgre_link_ops); 1767 rtnl_link_failed: 1768 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); 1769 add_proto_failed: 1770 unregister_pernet_device(&erspan_net_ops); 1771 pnet_erspan_failed: 1772 unregister_pernet_device(&ipgre_tap_net_ops); 1773 pnet_tap_failed: 1774 unregister_pernet_device(&ipgre_net_ops); 1775 return err; 1776 } 1777 1778 static void __exit ipgre_fini(void) 1779 { 1780 rtnl_link_unregister(&ipgre_tap_ops); 1781 rtnl_link_unregister(&ipgre_link_ops); 1782 rtnl_link_unregister(&erspan_link_ops); 1783 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); 1784 unregister_pernet_device(&ipgre_tap_net_ops); 1785 unregister_pernet_device(&ipgre_net_ops); 1786 unregister_pernet_device(&erspan_net_ops); 1787 } 1788 1789 module_init(ipgre_init); 1790 module_exit(ipgre_fini); 1791 MODULE_LICENSE("GPL"); 1792 MODULE_ALIAS_RTNL_LINK("gre"); 1793 MODULE_ALIAS_RTNL_LINK("gretap"); 1794 MODULE_ALIAS_RTNL_LINK("erspan"); 1795 MODULE_ALIAS_NETDEV("gre0"); 1796 MODULE_ALIAS_NETDEV("gretap0"); 1797 MODULE_ALIAS_NETDEV("erspan0"); 1798