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 if (pskb_trim(skb, dev->mtu + dev->hard_header_len)) 552 goto err_free_skb; 553 truncate = true; 554 } 555 556 nhoff = skb_network_offset(skb); 557 if (skb->protocol == htons(ETH_P_IP) && 558 (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff)) 559 truncate = true; 560 561 if (skb->protocol == htons(ETH_P_IPV6)) { 562 int thoff; 563 564 if (skb_transport_header_was_set(skb)) 565 thoff = skb_transport_offset(skb); 566 else 567 thoff = nhoff + sizeof(struct ipv6hdr); 568 if (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff) 569 truncate = true; 570 } 571 572 if (version == 1) { 573 erspan_build_header(skb, ntohl(tunnel_id_to_key32(key->tun_id)), 574 ntohl(md->u.index), truncate, true); 575 proto = htons(ETH_P_ERSPAN); 576 } else if (version == 2) { 577 erspan_build_header_v2(skb, 578 ntohl(tunnel_id_to_key32(key->tun_id)), 579 md->u.md2.dir, 580 get_hwid(&md->u.md2), 581 truncate, true); 582 proto = htons(ETH_P_ERSPAN2); 583 } else { 584 goto err_free_skb; 585 } 586 587 gre_build_header(skb, 8, TUNNEL_SEQ, 588 proto, 0, htonl(atomic_fetch_inc(&tunnel->o_seqno))); 589 590 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen); 591 592 return; 593 594 err_free_skb: 595 kfree_skb(skb); 596 DEV_STATS_INC(dev, tx_dropped); 597 } 598 599 static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb) 600 { 601 struct ip_tunnel_info *info = skb_tunnel_info(skb); 602 const struct ip_tunnel_key *key; 603 struct rtable *rt; 604 struct flowi4 fl4; 605 606 if (ip_tunnel_info_af(info) != AF_INET) 607 return -EINVAL; 608 609 key = &info->key; 610 ip_tunnel_init_flow(&fl4, IPPROTO_GRE, key->u.ipv4.dst, key->u.ipv4.src, 611 tunnel_id_to_key32(key->tun_id), 612 key->tos & ~INET_ECN_MASK, dev_net(dev), 0, 613 skb->mark, skb_get_hash(skb), key->flow_flags); 614 rt = ip_route_output_key(dev_net(dev), &fl4); 615 if (IS_ERR(rt)) 616 return PTR_ERR(rt); 617 618 ip_rt_put(rt); 619 info->key.u.ipv4.src = fl4.saddr; 620 return 0; 621 } 622 623 static netdev_tx_t ipgre_xmit(struct sk_buff *skb, 624 struct net_device *dev) 625 { 626 struct ip_tunnel *tunnel = netdev_priv(dev); 627 const struct iphdr *tnl_params; 628 629 if (!pskb_inet_may_pull(skb)) 630 goto free_skb; 631 632 if (tunnel->collect_md) { 633 gre_fb_xmit(skb, dev, skb->protocol); 634 return NETDEV_TX_OK; 635 } 636 637 if (dev->header_ops) { 638 if (skb_cow_head(skb, 0)) 639 goto free_skb; 640 641 tnl_params = (const struct iphdr *)skb->data; 642 643 /* Pull skb since ip_tunnel_xmit() needs skb->data pointing 644 * to gre header. 645 */ 646 skb_pull(skb, tunnel->hlen + sizeof(struct iphdr)); 647 skb_reset_mac_header(skb); 648 649 if (skb->ip_summed == CHECKSUM_PARTIAL && 650 skb_checksum_start(skb) < skb->data) 651 goto free_skb; 652 } else { 653 if (skb_cow_head(skb, dev->needed_headroom)) 654 goto free_skb; 655 656 tnl_params = &tunnel->parms.iph; 657 } 658 659 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM))) 660 goto free_skb; 661 662 __gre_xmit(skb, dev, tnl_params, skb->protocol); 663 return NETDEV_TX_OK; 664 665 free_skb: 666 kfree_skb(skb); 667 DEV_STATS_INC(dev, tx_dropped); 668 return NETDEV_TX_OK; 669 } 670 671 static netdev_tx_t erspan_xmit(struct sk_buff *skb, 672 struct net_device *dev) 673 { 674 struct ip_tunnel *tunnel = netdev_priv(dev); 675 bool truncate = false; 676 __be16 proto; 677 678 if (!pskb_inet_may_pull(skb)) 679 goto free_skb; 680 681 if (tunnel->collect_md) { 682 erspan_fb_xmit(skb, dev); 683 return NETDEV_TX_OK; 684 } 685 686 if (gre_handle_offloads(skb, false)) 687 goto free_skb; 688 689 if (skb_cow_head(skb, dev->needed_headroom)) 690 goto free_skb; 691 692 if (skb->len > dev->mtu + dev->hard_header_len) { 693 if (pskb_trim(skb, dev->mtu + dev->hard_header_len)) 694 goto free_skb; 695 truncate = true; 696 } 697 698 /* Push ERSPAN header */ 699 if (tunnel->erspan_ver == 0) { 700 proto = htons(ETH_P_ERSPAN); 701 tunnel->parms.o_flags &= ~TUNNEL_SEQ; 702 } else if (tunnel->erspan_ver == 1) { 703 erspan_build_header(skb, ntohl(tunnel->parms.o_key), 704 tunnel->index, 705 truncate, true); 706 proto = htons(ETH_P_ERSPAN); 707 } else if (tunnel->erspan_ver == 2) { 708 erspan_build_header_v2(skb, ntohl(tunnel->parms.o_key), 709 tunnel->dir, tunnel->hwid, 710 truncate, true); 711 proto = htons(ETH_P_ERSPAN2); 712 } else { 713 goto free_skb; 714 } 715 716 tunnel->parms.o_flags &= ~TUNNEL_KEY; 717 __gre_xmit(skb, dev, &tunnel->parms.iph, proto); 718 return NETDEV_TX_OK; 719 720 free_skb: 721 kfree_skb(skb); 722 DEV_STATS_INC(dev, tx_dropped); 723 return NETDEV_TX_OK; 724 } 725 726 static netdev_tx_t gre_tap_xmit(struct sk_buff *skb, 727 struct net_device *dev) 728 { 729 struct ip_tunnel *tunnel = netdev_priv(dev); 730 731 if (!pskb_inet_may_pull(skb)) 732 goto free_skb; 733 734 if (tunnel->collect_md) { 735 gre_fb_xmit(skb, dev, htons(ETH_P_TEB)); 736 return NETDEV_TX_OK; 737 } 738 739 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM))) 740 goto free_skb; 741 742 if (skb_cow_head(skb, dev->needed_headroom)) 743 goto free_skb; 744 745 __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB)); 746 return NETDEV_TX_OK; 747 748 free_skb: 749 kfree_skb(skb); 750 DEV_STATS_INC(dev, tx_dropped); 751 return NETDEV_TX_OK; 752 } 753 754 static void ipgre_link_update(struct net_device *dev, bool set_mtu) 755 { 756 struct ip_tunnel *tunnel = netdev_priv(dev); 757 __be16 flags; 758 int len; 759 760 len = tunnel->tun_hlen; 761 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags); 762 len = tunnel->tun_hlen - len; 763 tunnel->hlen = tunnel->hlen + len; 764 765 if (dev->header_ops) 766 dev->hard_header_len += len; 767 else 768 dev->needed_headroom += len; 769 770 if (set_mtu) 771 dev->mtu = max_t(int, dev->mtu - len, 68); 772 773 flags = tunnel->parms.o_flags; 774 775 if (flags & TUNNEL_SEQ || 776 (flags & TUNNEL_CSUM && tunnel->encap.type != TUNNEL_ENCAP_NONE)) { 777 dev->features &= ~NETIF_F_GSO_SOFTWARE; 778 dev->hw_features &= ~NETIF_F_GSO_SOFTWARE; 779 } else { 780 dev->features |= NETIF_F_GSO_SOFTWARE; 781 dev->hw_features |= NETIF_F_GSO_SOFTWARE; 782 } 783 } 784 785 static int ipgre_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, 786 int cmd) 787 { 788 int err; 789 790 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) { 791 if (p->iph.version != 4 || p->iph.protocol != IPPROTO_GRE || 792 p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)) || 793 ((p->i_flags | p->o_flags) & (GRE_VERSION | GRE_ROUTING))) 794 return -EINVAL; 795 } 796 797 p->i_flags = gre_flags_to_tnl_flags(p->i_flags); 798 p->o_flags = gre_flags_to_tnl_flags(p->o_flags); 799 800 err = ip_tunnel_ctl(dev, p, cmd); 801 if (err) 802 return err; 803 804 if (cmd == SIOCCHGTUNNEL) { 805 struct ip_tunnel *t = netdev_priv(dev); 806 807 t->parms.i_flags = p->i_flags; 808 t->parms.o_flags = p->o_flags; 809 810 if (strcmp(dev->rtnl_link_ops->kind, "erspan")) 811 ipgre_link_update(dev, true); 812 } 813 814 p->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags); 815 p->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags); 816 return 0; 817 } 818 819 /* Nice toy. Unfortunately, useless in real life :-) 820 It allows to construct virtual multiprotocol broadcast "LAN" 821 over the Internet, provided multicast routing is tuned. 822 823 824 I have no idea was this bicycle invented before me, 825 so that I had to set ARPHRD_IPGRE to a random value. 826 I have an impression, that Cisco could make something similar, 827 but this feature is apparently missing in IOS<=11.2(8). 828 829 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks 830 with broadcast 224.66.66.66. If you have access to mbone, play with me :-) 831 832 ping -t 255 224.66.66.66 833 834 If nobody answers, mbone does not work. 835 836 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255 837 ip addr add 10.66.66.<somewhat>/24 dev Universe 838 ifconfig Universe up 839 ifconfig Universe add fe80::<Your_real_addr>/10 840 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96 841 ftp 10.66.66.66 842 ... 843 ftp fec0:6666:6666::193.233.7.65 844 ... 845 */ 846 static int ipgre_header(struct sk_buff *skb, struct net_device *dev, 847 unsigned short type, 848 const void *daddr, const void *saddr, unsigned int len) 849 { 850 struct ip_tunnel *t = netdev_priv(dev); 851 struct iphdr *iph; 852 struct gre_base_hdr *greh; 853 854 iph = skb_push(skb, t->hlen + sizeof(*iph)); 855 greh = (struct gre_base_hdr *)(iph+1); 856 greh->flags = gre_tnl_flags_to_gre_flags(t->parms.o_flags); 857 greh->protocol = htons(type); 858 859 memcpy(iph, &t->parms.iph, sizeof(struct iphdr)); 860 861 /* Set the source hardware address. */ 862 if (saddr) 863 memcpy(&iph->saddr, saddr, 4); 864 if (daddr) 865 memcpy(&iph->daddr, daddr, 4); 866 if (iph->daddr) 867 return t->hlen + sizeof(*iph); 868 869 return -(t->hlen + sizeof(*iph)); 870 } 871 872 static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr) 873 { 874 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb); 875 memcpy(haddr, &iph->saddr, 4); 876 return 4; 877 } 878 879 static const struct header_ops ipgre_header_ops = { 880 .create = ipgre_header, 881 .parse = ipgre_header_parse, 882 }; 883 884 #ifdef CONFIG_NET_IPGRE_BROADCAST 885 static int ipgre_open(struct net_device *dev) 886 { 887 struct ip_tunnel *t = netdev_priv(dev); 888 889 if (ipv4_is_multicast(t->parms.iph.daddr)) { 890 struct flowi4 fl4; 891 struct rtable *rt; 892 893 rt = ip_route_output_gre(t->net, &fl4, 894 t->parms.iph.daddr, 895 t->parms.iph.saddr, 896 t->parms.o_key, 897 RT_TOS(t->parms.iph.tos), 898 t->parms.link); 899 if (IS_ERR(rt)) 900 return -EADDRNOTAVAIL; 901 dev = rt->dst.dev; 902 ip_rt_put(rt); 903 if (!__in_dev_get_rtnl(dev)) 904 return -EADDRNOTAVAIL; 905 t->mlink = dev->ifindex; 906 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr); 907 } 908 return 0; 909 } 910 911 static int ipgre_close(struct net_device *dev) 912 { 913 struct ip_tunnel *t = netdev_priv(dev); 914 915 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) { 916 struct in_device *in_dev; 917 in_dev = inetdev_by_index(t->net, t->mlink); 918 if (in_dev) 919 ip_mc_dec_group(in_dev, t->parms.iph.daddr); 920 } 921 return 0; 922 } 923 #endif 924 925 static const struct net_device_ops ipgre_netdev_ops = { 926 .ndo_init = ipgre_tunnel_init, 927 .ndo_uninit = ip_tunnel_uninit, 928 #ifdef CONFIG_NET_IPGRE_BROADCAST 929 .ndo_open = ipgre_open, 930 .ndo_stop = ipgre_close, 931 #endif 932 .ndo_start_xmit = ipgre_xmit, 933 .ndo_siocdevprivate = ip_tunnel_siocdevprivate, 934 .ndo_change_mtu = ip_tunnel_change_mtu, 935 .ndo_get_stats64 = dev_get_tstats64, 936 .ndo_get_iflink = ip_tunnel_get_iflink, 937 .ndo_tunnel_ctl = ipgre_tunnel_ctl, 938 }; 939 940 #define GRE_FEATURES (NETIF_F_SG | \ 941 NETIF_F_FRAGLIST | \ 942 NETIF_F_HIGHDMA | \ 943 NETIF_F_HW_CSUM) 944 945 static void ipgre_tunnel_setup(struct net_device *dev) 946 { 947 dev->netdev_ops = &ipgre_netdev_ops; 948 dev->type = ARPHRD_IPGRE; 949 ip_tunnel_setup(dev, ipgre_net_id); 950 } 951 952 static void __gre_tunnel_init(struct net_device *dev) 953 { 954 struct ip_tunnel *tunnel; 955 __be16 flags; 956 957 tunnel = netdev_priv(dev); 958 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags); 959 tunnel->parms.iph.protocol = IPPROTO_GRE; 960 961 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen; 962 dev->needed_headroom = tunnel->hlen + sizeof(tunnel->parms.iph); 963 964 dev->features |= GRE_FEATURES | NETIF_F_LLTX; 965 dev->hw_features |= GRE_FEATURES; 966 967 flags = tunnel->parms.o_flags; 968 969 /* TCP offload with GRE SEQ is not supported, nor can we support 2 970 * levels of outer headers requiring an update. 971 */ 972 if (flags & TUNNEL_SEQ) 973 return; 974 if (flags & TUNNEL_CSUM && tunnel->encap.type != TUNNEL_ENCAP_NONE) 975 return; 976 977 dev->features |= NETIF_F_GSO_SOFTWARE; 978 dev->hw_features |= NETIF_F_GSO_SOFTWARE; 979 } 980 981 static int ipgre_tunnel_init(struct net_device *dev) 982 { 983 struct ip_tunnel *tunnel = netdev_priv(dev); 984 struct iphdr *iph = &tunnel->parms.iph; 985 986 __gre_tunnel_init(dev); 987 988 __dev_addr_set(dev, &iph->saddr, 4); 989 memcpy(dev->broadcast, &iph->daddr, 4); 990 991 dev->flags = IFF_NOARP; 992 netif_keep_dst(dev); 993 dev->addr_len = 4; 994 995 if (iph->daddr && !tunnel->collect_md) { 996 #ifdef CONFIG_NET_IPGRE_BROADCAST 997 if (ipv4_is_multicast(iph->daddr)) { 998 if (!iph->saddr) 999 return -EINVAL; 1000 dev->flags = IFF_BROADCAST; 1001 dev->header_ops = &ipgre_header_ops; 1002 dev->hard_header_len = tunnel->hlen + sizeof(*iph); 1003 dev->needed_headroom = 0; 1004 } 1005 #endif 1006 } else if (!tunnel->collect_md) { 1007 dev->header_ops = &ipgre_header_ops; 1008 dev->hard_header_len = tunnel->hlen + sizeof(*iph); 1009 dev->needed_headroom = 0; 1010 } 1011 1012 return ip_tunnel_init(dev); 1013 } 1014 1015 static const struct gre_protocol ipgre_protocol = { 1016 .handler = gre_rcv, 1017 .err_handler = gre_err, 1018 }; 1019 1020 static int __net_init ipgre_init_net(struct net *net) 1021 { 1022 return ip_tunnel_init_net(net, ipgre_net_id, &ipgre_link_ops, NULL); 1023 } 1024 1025 static void __net_exit ipgre_exit_batch_net(struct list_head *list_net) 1026 { 1027 ip_tunnel_delete_nets(list_net, ipgre_net_id, &ipgre_link_ops); 1028 } 1029 1030 static struct pernet_operations ipgre_net_ops = { 1031 .init = ipgre_init_net, 1032 .exit_batch = ipgre_exit_batch_net, 1033 .id = &ipgre_net_id, 1034 .size = sizeof(struct ip_tunnel_net), 1035 }; 1036 1037 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[], 1038 struct netlink_ext_ack *extack) 1039 { 1040 __be16 flags; 1041 1042 if (!data) 1043 return 0; 1044 1045 flags = 0; 1046 if (data[IFLA_GRE_IFLAGS]) 1047 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); 1048 if (data[IFLA_GRE_OFLAGS]) 1049 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); 1050 if (flags & (GRE_VERSION|GRE_ROUTING)) 1051 return -EINVAL; 1052 1053 if (data[IFLA_GRE_COLLECT_METADATA] && 1054 data[IFLA_GRE_ENCAP_TYPE] && 1055 nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]) != TUNNEL_ENCAP_NONE) 1056 return -EINVAL; 1057 1058 return 0; 1059 } 1060 1061 static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[], 1062 struct netlink_ext_ack *extack) 1063 { 1064 __be32 daddr; 1065 1066 if (tb[IFLA_ADDRESS]) { 1067 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) 1068 return -EINVAL; 1069 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) 1070 return -EADDRNOTAVAIL; 1071 } 1072 1073 if (!data) 1074 goto out; 1075 1076 if (data[IFLA_GRE_REMOTE]) { 1077 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4); 1078 if (!daddr) 1079 return -EINVAL; 1080 } 1081 1082 out: 1083 return ipgre_tunnel_validate(tb, data, extack); 1084 } 1085 1086 static int erspan_validate(struct nlattr *tb[], struct nlattr *data[], 1087 struct netlink_ext_ack *extack) 1088 { 1089 __be16 flags = 0; 1090 int ret; 1091 1092 if (!data) 1093 return 0; 1094 1095 ret = ipgre_tap_validate(tb, data, extack); 1096 if (ret) 1097 return ret; 1098 1099 if (data[IFLA_GRE_ERSPAN_VER] && 1100 nla_get_u8(data[IFLA_GRE_ERSPAN_VER]) == 0) 1101 return 0; 1102 1103 /* ERSPAN type II/III should only have GRE sequence and key flag */ 1104 if (data[IFLA_GRE_OFLAGS]) 1105 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); 1106 if (data[IFLA_GRE_IFLAGS]) 1107 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); 1108 if (!data[IFLA_GRE_COLLECT_METADATA] && 1109 flags != (GRE_SEQ | GRE_KEY)) 1110 return -EINVAL; 1111 1112 /* ERSPAN Session ID only has 10-bit. Since we reuse 1113 * 32-bit key field as ID, check it's range. 1114 */ 1115 if (data[IFLA_GRE_IKEY] && 1116 (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK)) 1117 return -EINVAL; 1118 1119 if (data[IFLA_GRE_OKEY] && 1120 (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK)) 1121 return -EINVAL; 1122 1123 return 0; 1124 } 1125 1126 static int ipgre_netlink_parms(struct net_device *dev, 1127 struct nlattr *data[], 1128 struct nlattr *tb[], 1129 struct ip_tunnel_parm *parms, 1130 __u32 *fwmark) 1131 { 1132 struct ip_tunnel *t = netdev_priv(dev); 1133 1134 memset(parms, 0, sizeof(*parms)); 1135 1136 parms->iph.protocol = IPPROTO_GRE; 1137 1138 if (!data) 1139 return 0; 1140 1141 if (data[IFLA_GRE_LINK]) 1142 parms->link = nla_get_u32(data[IFLA_GRE_LINK]); 1143 1144 if (data[IFLA_GRE_IFLAGS]) 1145 parms->i_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_IFLAGS])); 1146 1147 if (data[IFLA_GRE_OFLAGS]) 1148 parms->o_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_OFLAGS])); 1149 1150 if (data[IFLA_GRE_IKEY]) 1151 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]); 1152 1153 if (data[IFLA_GRE_OKEY]) 1154 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]); 1155 1156 if (data[IFLA_GRE_LOCAL]) 1157 parms->iph.saddr = nla_get_in_addr(data[IFLA_GRE_LOCAL]); 1158 1159 if (data[IFLA_GRE_REMOTE]) 1160 parms->iph.daddr = nla_get_in_addr(data[IFLA_GRE_REMOTE]); 1161 1162 if (data[IFLA_GRE_TTL]) 1163 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]); 1164 1165 if (data[IFLA_GRE_TOS]) 1166 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]); 1167 1168 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC])) { 1169 if (t->ignore_df) 1170 return -EINVAL; 1171 parms->iph.frag_off = htons(IP_DF); 1172 } 1173 1174 if (data[IFLA_GRE_COLLECT_METADATA]) { 1175 t->collect_md = true; 1176 if (dev->type == ARPHRD_IPGRE) 1177 dev->type = ARPHRD_NONE; 1178 } 1179 1180 if (data[IFLA_GRE_IGNORE_DF]) { 1181 if (nla_get_u8(data[IFLA_GRE_IGNORE_DF]) 1182 && (parms->iph.frag_off & htons(IP_DF))) 1183 return -EINVAL; 1184 t->ignore_df = !!nla_get_u8(data[IFLA_GRE_IGNORE_DF]); 1185 } 1186 1187 if (data[IFLA_GRE_FWMARK]) 1188 *fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]); 1189 1190 return 0; 1191 } 1192 1193 static int erspan_netlink_parms(struct net_device *dev, 1194 struct nlattr *data[], 1195 struct nlattr *tb[], 1196 struct ip_tunnel_parm *parms, 1197 __u32 *fwmark) 1198 { 1199 struct ip_tunnel *t = netdev_priv(dev); 1200 int err; 1201 1202 err = ipgre_netlink_parms(dev, data, tb, parms, fwmark); 1203 if (err) 1204 return err; 1205 if (!data) 1206 return 0; 1207 1208 if (data[IFLA_GRE_ERSPAN_VER]) { 1209 t->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]); 1210 1211 if (t->erspan_ver > 2) 1212 return -EINVAL; 1213 } 1214 1215 if (t->erspan_ver == 1) { 1216 if (data[IFLA_GRE_ERSPAN_INDEX]) { 1217 t->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]); 1218 if (t->index & ~INDEX_MASK) 1219 return -EINVAL; 1220 } 1221 } else if (t->erspan_ver == 2) { 1222 if (data[IFLA_GRE_ERSPAN_DIR]) { 1223 t->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]); 1224 if (t->dir & ~(DIR_MASK >> DIR_OFFSET)) 1225 return -EINVAL; 1226 } 1227 if (data[IFLA_GRE_ERSPAN_HWID]) { 1228 t->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]); 1229 if (t->hwid & ~(HWID_MASK >> HWID_OFFSET)) 1230 return -EINVAL; 1231 } 1232 } 1233 1234 return 0; 1235 } 1236 1237 /* This function returns true when ENCAP attributes are present in the nl msg */ 1238 static bool ipgre_netlink_encap_parms(struct nlattr *data[], 1239 struct ip_tunnel_encap *ipencap) 1240 { 1241 bool ret = false; 1242 1243 memset(ipencap, 0, sizeof(*ipencap)); 1244 1245 if (!data) 1246 return ret; 1247 1248 if (data[IFLA_GRE_ENCAP_TYPE]) { 1249 ret = true; 1250 ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]); 1251 } 1252 1253 if (data[IFLA_GRE_ENCAP_FLAGS]) { 1254 ret = true; 1255 ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]); 1256 } 1257 1258 if (data[IFLA_GRE_ENCAP_SPORT]) { 1259 ret = true; 1260 ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]); 1261 } 1262 1263 if (data[IFLA_GRE_ENCAP_DPORT]) { 1264 ret = true; 1265 ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]); 1266 } 1267 1268 return ret; 1269 } 1270 1271 static int gre_tap_init(struct net_device *dev) 1272 { 1273 __gre_tunnel_init(dev); 1274 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1275 netif_keep_dst(dev); 1276 1277 return ip_tunnel_init(dev); 1278 } 1279 1280 static const struct net_device_ops gre_tap_netdev_ops = { 1281 .ndo_init = gre_tap_init, 1282 .ndo_uninit = ip_tunnel_uninit, 1283 .ndo_start_xmit = gre_tap_xmit, 1284 .ndo_set_mac_address = eth_mac_addr, 1285 .ndo_validate_addr = eth_validate_addr, 1286 .ndo_change_mtu = ip_tunnel_change_mtu, 1287 .ndo_get_stats64 = dev_get_tstats64, 1288 .ndo_get_iflink = ip_tunnel_get_iflink, 1289 .ndo_fill_metadata_dst = gre_fill_metadata_dst, 1290 }; 1291 1292 static int erspan_tunnel_init(struct net_device *dev) 1293 { 1294 struct ip_tunnel *tunnel = netdev_priv(dev); 1295 1296 if (tunnel->erspan_ver == 0) 1297 tunnel->tun_hlen = 4; /* 4-byte GRE hdr. */ 1298 else 1299 tunnel->tun_hlen = 8; /* 8-byte GRE hdr. */ 1300 1301 tunnel->parms.iph.protocol = IPPROTO_GRE; 1302 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen + 1303 erspan_hdr_len(tunnel->erspan_ver); 1304 1305 dev->features |= GRE_FEATURES; 1306 dev->hw_features |= GRE_FEATURES; 1307 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1308 netif_keep_dst(dev); 1309 1310 return ip_tunnel_init(dev); 1311 } 1312 1313 static const struct net_device_ops erspan_netdev_ops = { 1314 .ndo_init = erspan_tunnel_init, 1315 .ndo_uninit = ip_tunnel_uninit, 1316 .ndo_start_xmit = erspan_xmit, 1317 .ndo_set_mac_address = eth_mac_addr, 1318 .ndo_validate_addr = eth_validate_addr, 1319 .ndo_change_mtu = ip_tunnel_change_mtu, 1320 .ndo_get_stats64 = dev_get_tstats64, 1321 .ndo_get_iflink = ip_tunnel_get_iflink, 1322 .ndo_fill_metadata_dst = gre_fill_metadata_dst, 1323 }; 1324 1325 static void ipgre_tap_setup(struct net_device *dev) 1326 { 1327 ether_setup(dev); 1328 dev->max_mtu = 0; 1329 dev->netdev_ops = &gre_tap_netdev_ops; 1330 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 1331 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1332 ip_tunnel_setup(dev, gre_tap_net_id); 1333 } 1334 1335 static int 1336 ipgre_newlink_encap_setup(struct net_device *dev, struct nlattr *data[]) 1337 { 1338 struct ip_tunnel_encap ipencap; 1339 1340 if (ipgre_netlink_encap_parms(data, &ipencap)) { 1341 struct ip_tunnel *t = netdev_priv(dev); 1342 int err = ip_tunnel_encap_setup(t, &ipencap); 1343 1344 if (err < 0) 1345 return err; 1346 } 1347 1348 return 0; 1349 } 1350 1351 static int ipgre_newlink(struct net *src_net, struct net_device *dev, 1352 struct nlattr *tb[], struct nlattr *data[], 1353 struct netlink_ext_ack *extack) 1354 { 1355 struct ip_tunnel_parm p; 1356 __u32 fwmark = 0; 1357 int err; 1358 1359 err = ipgre_newlink_encap_setup(dev, data); 1360 if (err) 1361 return err; 1362 1363 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark); 1364 if (err < 0) 1365 return err; 1366 return ip_tunnel_newlink(dev, tb, &p, fwmark); 1367 } 1368 1369 static int erspan_newlink(struct net *src_net, struct net_device *dev, 1370 struct nlattr *tb[], struct nlattr *data[], 1371 struct netlink_ext_ack *extack) 1372 { 1373 struct ip_tunnel_parm p; 1374 __u32 fwmark = 0; 1375 int err; 1376 1377 err = ipgre_newlink_encap_setup(dev, data); 1378 if (err) 1379 return err; 1380 1381 err = erspan_netlink_parms(dev, data, tb, &p, &fwmark); 1382 if (err) 1383 return err; 1384 return ip_tunnel_newlink(dev, tb, &p, fwmark); 1385 } 1386 1387 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[], 1388 struct nlattr *data[], 1389 struct netlink_ext_ack *extack) 1390 { 1391 struct ip_tunnel *t = netdev_priv(dev); 1392 __u32 fwmark = t->fwmark; 1393 struct ip_tunnel_parm p; 1394 int err; 1395 1396 err = ipgre_newlink_encap_setup(dev, data); 1397 if (err) 1398 return err; 1399 1400 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark); 1401 if (err < 0) 1402 return err; 1403 1404 err = ip_tunnel_changelink(dev, tb, &p, fwmark); 1405 if (err < 0) 1406 return err; 1407 1408 t->parms.i_flags = p.i_flags; 1409 t->parms.o_flags = p.o_flags; 1410 1411 ipgre_link_update(dev, !tb[IFLA_MTU]); 1412 1413 return 0; 1414 } 1415 1416 static int erspan_changelink(struct net_device *dev, struct nlattr *tb[], 1417 struct nlattr *data[], 1418 struct netlink_ext_ack *extack) 1419 { 1420 struct ip_tunnel *t = netdev_priv(dev); 1421 __u32 fwmark = t->fwmark; 1422 struct ip_tunnel_parm p; 1423 int err; 1424 1425 err = ipgre_newlink_encap_setup(dev, data); 1426 if (err) 1427 return err; 1428 1429 err = erspan_netlink_parms(dev, data, tb, &p, &fwmark); 1430 if (err < 0) 1431 return err; 1432 1433 err = ip_tunnel_changelink(dev, tb, &p, fwmark); 1434 if (err < 0) 1435 return err; 1436 1437 t->parms.i_flags = p.i_flags; 1438 t->parms.o_flags = p.o_flags; 1439 1440 return 0; 1441 } 1442 1443 static size_t ipgre_get_size(const struct net_device *dev) 1444 { 1445 return 1446 /* IFLA_GRE_LINK */ 1447 nla_total_size(4) + 1448 /* IFLA_GRE_IFLAGS */ 1449 nla_total_size(2) + 1450 /* IFLA_GRE_OFLAGS */ 1451 nla_total_size(2) + 1452 /* IFLA_GRE_IKEY */ 1453 nla_total_size(4) + 1454 /* IFLA_GRE_OKEY */ 1455 nla_total_size(4) + 1456 /* IFLA_GRE_LOCAL */ 1457 nla_total_size(4) + 1458 /* IFLA_GRE_REMOTE */ 1459 nla_total_size(4) + 1460 /* IFLA_GRE_TTL */ 1461 nla_total_size(1) + 1462 /* IFLA_GRE_TOS */ 1463 nla_total_size(1) + 1464 /* IFLA_GRE_PMTUDISC */ 1465 nla_total_size(1) + 1466 /* IFLA_GRE_ENCAP_TYPE */ 1467 nla_total_size(2) + 1468 /* IFLA_GRE_ENCAP_FLAGS */ 1469 nla_total_size(2) + 1470 /* IFLA_GRE_ENCAP_SPORT */ 1471 nla_total_size(2) + 1472 /* IFLA_GRE_ENCAP_DPORT */ 1473 nla_total_size(2) + 1474 /* IFLA_GRE_COLLECT_METADATA */ 1475 nla_total_size(0) + 1476 /* IFLA_GRE_IGNORE_DF */ 1477 nla_total_size(1) + 1478 /* IFLA_GRE_FWMARK */ 1479 nla_total_size(4) + 1480 /* IFLA_GRE_ERSPAN_INDEX */ 1481 nla_total_size(4) + 1482 /* IFLA_GRE_ERSPAN_VER */ 1483 nla_total_size(1) + 1484 /* IFLA_GRE_ERSPAN_DIR */ 1485 nla_total_size(1) + 1486 /* IFLA_GRE_ERSPAN_HWID */ 1487 nla_total_size(2) + 1488 0; 1489 } 1490 1491 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev) 1492 { 1493 struct ip_tunnel *t = netdev_priv(dev); 1494 struct ip_tunnel_parm *p = &t->parms; 1495 __be16 o_flags = p->o_flags; 1496 1497 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) || 1498 nla_put_be16(skb, IFLA_GRE_IFLAGS, 1499 gre_tnl_flags_to_gre_flags(p->i_flags)) || 1500 nla_put_be16(skb, IFLA_GRE_OFLAGS, 1501 gre_tnl_flags_to_gre_flags(o_flags)) || 1502 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) || 1503 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) || 1504 nla_put_in_addr(skb, IFLA_GRE_LOCAL, p->iph.saddr) || 1505 nla_put_in_addr(skb, IFLA_GRE_REMOTE, p->iph.daddr) || 1506 nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) || 1507 nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) || 1508 nla_put_u8(skb, IFLA_GRE_PMTUDISC, 1509 !!(p->iph.frag_off & htons(IP_DF))) || 1510 nla_put_u32(skb, IFLA_GRE_FWMARK, t->fwmark)) 1511 goto nla_put_failure; 1512 1513 if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE, 1514 t->encap.type) || 1515 nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT, 1516 t->encap.sport) || 1517 nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT, 1518 t->encap.dport) || 1519 nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS, 1520 t->encap.flags)) 1521 goto nla_put_failure; 1522 1523 if (nla_put_u8(skb, IFLA_GRE_IGNORE_DF, t->ignore_df)) 1524 goto nla_put_failure; 1525 1526 if (t->collect_md) { 1527 if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA)) 1528 goto nla_put_failure; 1529 } 1530 1531 return 0; 1532 1533 nla_put_failure: 1534 return -EMSGSIZE; 1535 } 1536 1537 static int erspan_fill_info(struct sk_buff *skb, const struct net_device *dev) 1538 { 1539 struct ip_tunnel *t = netdev_priv(dev); 1540 1541 if (t->erspan_ver <= 2) { 1542 if (t->erspan_ver != 0 && !t->collect_md) 1543 t->parms.o_flags |= TUNNEL_KEY; 1544 1545 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, t->erspan_ver)) 1546 goto nla_put_failure; 1547 1548 if (t->erspan_ver == 1) { 1549 if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, t->index)) 1550 goto nla_put_failure; 1551 } else if (t->erspan_ver == 2) { 1552 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, t->dir)) 1553 goto nla_put_failure; 1554 if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, t->hwid)) 1555 goto nla_put_failure; 1556 } 1557 } 1558 1559 return ipgre_fill_info(skb, dev); 1560 1561 nla_put_failure: 1562 return -EMSGSIZE; 1563 } 1564 1565 static void erspan_setup(struct net_device *dev) 1566 { 1567 struct ip_tunnel *t = netdev_priv(dev); 1568 1569 ether_setup(dev); 1570 dev->max_mtu = 0; 1571 dev->netdev_ops = &erspan_netdev_ops; 1572 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 1573 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1574 ip_tunnel_setup(dev, erspan_net_id); 1575 t->erspan_ver = 1; 1576 } 1577 1578 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = { 1579 [IFLA_GRE_LINK] = { .type = NLA_U32 }, 1580 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 }, 1581 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 }, 1582 [IFLA_GRE_IKEY] = { .type = NLA_U32 }, 1583 [IFLA_GRE_OKEY] = { .type = NLA_U32 }, 1584 [IFLA_GRE_LOCAL] = { .len = sizeof_field(struct iphdr, saddr) }, 1585 [IFLA_GRE_REMOTE] = { .len = sizeof_field(struct iphdr, daddr) }, 1586 [IFLA_GRE_TTL] = { .type = NLA_U8 }, 1587 [IFLA_GRE_TOS] = { .type = NLA_U8 }, 1588 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 }, 1589 [IFLA_GRE_ENCAP_TYPE] = { .type = NLA_U16 }, 1590 [IFLA_GRE_ENCAP_FLAGS] = { .type = NLA_U16 }, 1591 [IFLA_GRE_ENCAP_SPORT] = { .type = NLA_U16 }, 1592 [IFLA_GRE_ENCAP_DPORT] = { .type = NLA_U16 }, 1593 [IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG }, 1594 [IFLA_GRE_IGNORE_DF] = { .type = NLA_U8 }, 1595 [IFLA_GRE_FWMARK] = { .type = NLA_U32 }, 1596 [IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 }, 1597 [IFLA_GRE_ERSPAN_VER] = { .type = NLA_U8 }, 1598 [IFLA_GRE_ERSPAN_DIR] = { .type = NLA_U8 }, 1599 [IFLA_GRE_ERSPAN_HWID] = { .type = NLA_U16 }, 1600 }; 1601 1602 static struct rtnl_link_ops ipgre_link_ops __read_mostly = { 1603 .kind = "gre", 1604 .maxtype = IFLA_GRE_MAX, 1605 .policy = ipgre_policy, 1606 .priv_size = sizeof(struct ip_tunnel), 1607 .setup = ipgre_tunnel_setup, 1608 .validate = ipgre_tunnel_validate, 1609 .newlink = ipgre_newlink, 1610 .changelink = ipgre_changelink, 1611 .dellink = ip_tunnel_dellink, 1612 .get_size = ipgre_get_size, 1613 .fill_info = ipgre_fill_info, 1614 .get_link_net = ip_tunnel_get_link_net, 1615 }; 1616 1617 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = { 1618 .kind = "gretap", 1619 .maxtype = IFLA_GRE_MAX, 1620 .policy = ipgre_policy, 1621 .priv_size = sizeof(struct ip_tunnel), 1622 .setup = ipgre_tap_setup, 1623 .validate = ipgre_tap_validate, 1624 .newlink = ipgre_newlink, 1625 .changelink = ipgre_changelink, 1626 .dellink = ip_tunnel_dellink, 1627 .get_size = ipgre_get_size, 1628 .fill_info = ipgre_fill_info, 1629 .get_link_net = ip_tunnel_get_link_net, 1630 }; 1631 1632 static struct rtnl_link_ops erspan_link_ops __read_mostly = { 1633 .kind = "erspan", 1634 .maxtype = IFLA_GRE_MAX, 1635 .policy = ipgre_policy, 1636 .priv_size = sizeof(struct ip_tunnel), 1637 .setup = erspan_setup, 1638 .validate = erspan_validate, 1639 .newlink = erspan_newlink, 1640 .changelink = erspan_changelink, 1641 .dellink = ip_tunnel_dellink, 1642 .get_size = ipgre_get_size, 1643 .fill_info = erspan_fill_info, 1644 .get_link_net = ip_tunnel_get_link_net, 1645 }; 1646 1647 struct net_device *gretap_fb_dev_create(struct net *net, const char *name, 1648 u8 name_assign_type) 1649 { 1650 struct nlattr *tb[IFLA_MAX + 1]; 1651 struct net_device *dev; 1652 LIST_HEAD(list_kill); 1653 struct ip_tunnel *t; 1654 int err; 1655 1656 memset(&tb, 0, sizeof(tb)); 1657 1658 dev = rtnl_create_link(net, name, name_assign_type, 1659 &ipgre_tap_ops, tb, NULL); 1660 if (IS_ERR(dev)) 1661 return dev; 1662 1663 /* Configure flow based GRE device. */ 1664 t = netdev_priv(dev); 1665 t->collect_md = true; 1666 1667 err = ipgre_newlink(net, dev, tb, NULL, NULL); 1668 if (err < 0) { 1669 free_netdev(dev); 1670 return ERR_PTR(err); 1671 } 1672 1673 /* openvswitch users expect packet sizes to be unrestricted, 1674 * so set the largest MTU we can. 1675 */ 1676 err = __ip_tunnel_change_mtu(dev, IP_MAX_MTU, false); 1677 if (err) 1678 goto out; 1679 1680 err = rtnl_configure_link(dev, NULL, 0, NULL); 1681 if (err < 0) 1682 goto out; 1683 1684 return dev; 1685 out: 1686 ip_tunnel_dellink(dev, &list_kill); 1687 unregister_netdevice_many(&list_kill); 1688 return ERR_PTR(err); 1689 } 1690 EXPORT_SYMBOL_GPL(gretap_fb_dev_create); 1691 1692 static int __net_init ipgre_tap_init_net(struct net *net) 1693 { 1694 return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, "gretap0"); 1695 } 1696 1697 static void __net_exit ipgre_tap_exit_batch_net(struct list_head *list_net) 1698 { 1699 ip_tunnel_delete_nets(list_net, gre_tap_net_id, &ipgre_tap_ops); 1700 } 1701 1702 static struct pernet_operations ipgre_tap_net_ops = { 1703 .init = ipgre_tap_init_net, 1704 .exit_batch = ipgre_tap_exit_batch_net, 1705 .id = &gre_tap_net_id, 1706 .size = sizeof(struct ip_tunnel_net), 1707 }; 1708 1709 static int __net_init erspan_init_net(struct net *net) 1710 { 1711 return ip_tunnel_init_net(net, erspan_net_id, 1712 &erspan_link_ops, "erspan0"); 1713 } 1714 1715 static void __net_exit erspan_exit_batch_net(struct list_head *net_list) 1716 { 1717 ip_tunnel_delete_nets(net_list, erspan_net_id, &erspan_link_ops); 1718 } 1719 1720 static struct pernet_operations erspan_net_ops = { 1721 .init = erspan_init_net, 1722 .exit_batch = erspan_exit_batch_net, 1723 .id = &erspan_net_id, 1724 .size = sizeof(struct ip_tunnel_net), 1725 }; 1726 1727 static int __init ipgre_init(void) 1728 { 1729 int err; 1730 1731 pr_info("GRE over IPv4 tunneling driver\n"); 1732 1733 err = register_pernet_device(&ipgre_net_ops); 1734 if (err < 0) 1735 return err; 1736 1737 err = register_pernet_device(&ipgre_tap_net_ops); 1738 if (err < 0) 1739 goto pnet_tap_failed; 1740 1741 err = register_pernet_device(&erspan_net_ops); 1742 if (err < 0) 1743 goto pnet_erspan_failed; 1744 1745 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO); 1746 if (err < 0) { 1747 pr_info("%s: can't add protocol\n", __func__); 1748 goto add_proto_failed; 1749 } 1750 1751 err = rtnl_link_register(&ipgre_link_ops); 1752 if (err < 0) 1753 goto rtnl_link_failed; 1754 1755 err = rtnl_link_register(&ipgre_tap_ops); 1756 if (err < 0) 1757 goto tap_ops_failed; 1758 1759 err = rtnl_link_register(&erspan_link_ops); 1760 if (err < 0) 1761 goto erspan_link_failed; 1762 1763 return 0; 1764 1765 erspan_link_failed: 1766 rtnl_link_unregister(&ipgre_tap_ops); 1767 tap_ops_failed: 1768 rtnl_link_unregister(&ipgre_link_ops); 1769 rtnl_link_failed: 1770 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); 1771 add_proto_failed: 1772 unregister_pernet_device(&erspan_net_ops); 1773 pnet_erspan_failed: 1774 unregister_pernet_device(&ipgre_tap_net_ops); 1775 pnet_tap_failed: 1776 unregister_pernet_device(&ipgre_net_ops); 1777 return err; 1778 } 1779 1780 static void __exit ipgre_fini(void) 1781 { 1782 rtnl_link_unregister(&ipgre_tap_ops); 1783 rtnl_link_unregister(&ipgre_link_ops); 1784 rtnl_link_unregister(&erspan_link_ops); 1785 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); 1786 unregister_pernet_device(&ipgre_tap_net_ops); 1787 unregister_pernet_device(&ipgre_net_ops); 1788 unregister_pernet_device(&erspan_net_ops); 1789 } 1790 1791 module_init(ipgre_init); 1792 module_exit(ipgre_fini); 1793 MODULE_LICENSE("GPL"); 1794 MODULE_ALIAS_RTNL_LINK("gre"); 1795 MODULE_ALIAS_RTNL_LINK("gretap"); 1796 MODULE_ALIAS_RTNL_LINK("erspan"); 1797 MODULE_ALIAS_NETDEV("gre0"); 1798 MODULE_ALIAS_NETDEV("gretap0"); 1799 MODULE_ALIAS_NETDEV("erspan0"); 1800