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); 462 463 if (tunnel->parms.o_flags & TUNNEL_SEQ) 464 tunnel->o_seqno++; 465 466 /* Push GRE header. */ 467 gre_build_header(skb, tunnel->tun_hlen, 468 tunnel->parms.o_flags, proto, tunnel->parms.o_key, 469 htonl(tunnel->o_seqno)); 470 471 ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol); 472 } 473 474 static int gre_handle_offloads(struct sk_buff *skb, bool csum) 475 { 476 if (csum && skb_checksum_start(skb) < skb->data) 477 return -EINVAL; 478 return iptunnel_handle_offloads(skb, csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE); 479 } 480 481 static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev, 482 __be16 proto) 483 { 484 struct ip_tunnel *tunnel = netdev_priv(dev); 485 struct ip_tunnel_info *tun_info; 486 const struct ip_tunnel_key *key; 487 int tunnel_hlen; 488 __be16 flags; 489 490 tun_info = skb_tunnel_info(skb); 491 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) || 492 ip_tunnel_info_af(tun_info) != AF_INET)) 493 goto err_free_skb; 494 495 key = &tun_info->key; 496 tunnel_hlen = gre_calc_hlen(key->tun_flags); 497 498 if (skb_cow_head(skb, dev->needed_headroom)) 499 goto err_free_skb; 500 501 /* Push Tunnel header. */ 502 if (gre_handle_offloads(skb, !!(tun_info->key.tun_flags & TUNNEL_CSUM))) 503 goto err_free_skb; 504 505 flags = tun_info->key.tun_flags & 506 (TUNNEL_CSUM | TUNNEL_KEY | TUNNEL_SEQ); 507 gre_build_header(skb, tunnel_hlen, flags, proto, 508 tunnel_id_to_key32(tun_info->key.tun_id), 509 (flags & TUNNEL_SEQ) ? htonl(tunnel->o_seqno++) : 0); 510 511 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen); 512 513 return; 514 515 err_free_skb: 516 kfree_skb(skb); 517 dev->stats.tx_dropped++; 518 } 519 520 static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev) 521 { 522 struct ip_tunnel *tunnel = netdev_priv(dev); 523 struct ip_tunnel_info *tun_info; 524 const struct ip_tunnel_key *key; 525 struct erspan_metadata *md; 526 bool truncate = false; 527 __be16 proto; 528 int tunnel_hlen; 529 int version; 530 int nhoff; 531 int thoff; 532 533 tun_info = skb_tunnel_info(skb); 534 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) || 535 ip_tunnel_info_af(tun_info) != AF_INET)) 536 goto err_free_skb; 537 538 key = &tun_info->key; 539 if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT)) 540 goto err_free_skb; 541 if (tun_info->options_len < sizeof(*md)) 542 goto err_free_skb; 543 md = ip_tunnel_info_opts(tun_info); 544 545 /* ERSPAN has fixed 8 byte GRE header */ 546 version = md->version; 547 tunnel_hlen = 8 + erspan_hdr_len(version); 548 549 if (skb_cow_head(skb, dev->needed_headroom)) 550 goto err_free_skb; 551 552 if (gre_handle_offloads(skb, false)) 553 goto err_free_skb; 554 555 if (skb->len > dev->mtu + dev->hard_header_len) { 556 pskb_trim(skb, dev->mtu + dev->hard_header_len); 557 truncate = true; 558 } 559 560 nhoff = skb_network_header(skb) - skb_mac_header(skb); 561 if (skb->protocol == htons(ETH_P_IP) && 562 (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff)) 563 truncate = true; 564 565 thoff = skb_transport_header(skb) - skb_mac_header(skb); 566 if (skb->protocol == htons(ETH_P_IPV6) && 567 (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff)) 568 truncate = true; 569 570 if (version == 1) { 571 erspan_build_header(skb, ntohl(tunnel_id_to_key32(key->tun_id)), 572 ntohl(md->u.index), truncate, true); 573 proto = htons(ETH_P_ERSPAN); 574 } else if (version == 2) { 575 erspan_build_header_v2(skb, 576 ntohl(tunnel_id_to_key32(key->tun_id)), 577 md->u.md2.dir, 578 get_hwid(&md->u.md2), 579 truncate, true); 580 proto = htons(ETH_P_ERSPAN2); 581 } else { 582 goto err_free_skb; 583 } 584 585 gre_build_header(skb, 8, TUNNEL_SEQ, 586 proto, 0, htonl(tunnel->o_seqno++)); 587 588 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen); 589 590 return; 591 592 err_free_skb: 593 kfree_skb(skb); 594 dev->stats.tx_dropped++; 595 } 596 597 static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb) 598 { 599 struct ip_tunnel_info *info = skb_tunnel_info(skb); 600 const struct ip_tunnel_key *key; 601 struct rtable *rt; 602 struct flowi4 fl4; 603 604 if (ip_tunnel_info_af(info) != AF_INET) 605 return -EINVAL; 606 607 key = &info->key; 608 ip_tunnel_init_flow(&fl4, IPPROTO_GRE, key->u.ipv4.dst, key->u.ipv4.src, 609 tunnel_id_to_key32(key->tun_id), key->tos, 0, 610 skb->mark, skb_get_hash(skb)); 611 rt = ip_route_output_key(dev_net(dev), &fl4); 612 if (IS_ERR(rt)) 613 return PTR_ERR(rt); 614 615 ip_rt_put(rt); 616 info->key.u.ipv4.src = fl4.saddr; 617 return 0; 618 } 619 620 static netdev_tx_t ipgre_xmit(struct sk_buff *skb, 621 struct net_device *dev) 622 { 623 struct ip_tunnel *tunnel = netdev_priv(dev); 624 const struct iphdr *tnl_params; 625 626 if (!pskb_inet_may_pull(skb)) 627 goto free_skb; 628 629 if (tunnel->collect_md) { 630 gre_fb_xmit(skb, dev, skb->protocol); 631 return NETDEV_TX_OK; 632 } 633 634 if (dev->header_ops) { 635 if (skb_cow_head(skb, 0)) 636 goto free_skb; 637 638 tnl_params = (const struct iphdr *)skb->data; 639 640 /* Pull skb since ip_tunnel_xmit() needs skb->data pointing 641 * to gre header. 642 */ 643 skb_pull(skb, tunnel->hlen + sizeof(struct iphdr)); 644 skb_reset_mac_header(skb); 645 } else { 646 if (skb_cow_head(skb, dev->needed_headroom)) 647 goto free_skb; 648 649 tnl_params = &tunnel->parms.iph; 650 } 651 652 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM))) 653 goto free_skb; 654 655 __gre_xmit(skb, dev, tnl_params, skb->protocol); 656 return NETDEV_TX_OK; 657 658 free_skb: 659 kfree_skb(skb); 660 dev->stats.tx_dropped++; 661 return NETDEV_TX_OK; 662 } 663 664 static netdev_tx_t erspan_xmit(struct sk_buff *skb, 665 struct net_device *dev) 666 { 667 struct ip_tunnel *tunnel = netdev_priv(dev); 668 bool truncate = false; 669 __be16 proto; 670 671 if (!pskb_inet_may_pull(skb)) 672 goto free_skb; 673 674 if (tunnel->collect_md) { 675 erspan_fb_xmit(skb, dev); 676 return NETDEV_TX_OK; 677 } 678 679 if (gre_handle_offloads(skb, false)) 680 goto free_skb; 681 682 if (skb_cow_head(skb, dev->needed_headroom)) 683 goto free_skb; 684 685 if (skb->len > dev->mtu + dev->hard_header_len) { 686 pskb_trim(skb, dev->mtu + dev->hard_header_len); 687 truncate = true; 688 } 689 690 /* Push ERSPAN header */ 691 if (tunnel->erspan_ver == 0) { 692 proto = htons(ETH_P_ERSPAN); 693 tunnel->parms.o_flags &= ~TUNNEL_SEQ; 694 } else if (tunnel->erspan_ver == 1) { 695 erspan_build_header(skb, ntohl(tunnel->parms.o_key), 696 tunnel->index, 697 truncate, true); 698 proto = htons(ETH_P_ERSPAN); 699 } else if (tunnel->erspan_ver == 2) { 700 erspan_build_header_v2(skb, ntohl(tunnel->parms.o_key), 701 tunnel->dir, tunnel->hwid, 702 truncate, true); 703 proto = htons(ETH_P_ERSPAN2); 704 } else { 705 goto free_skb; 706 } 707 708 tunnel->parms.o_flags &= ~TUNNEL_KEY; 709 __gre_xmit(skb, dev, &tunnel->parms.iph, proto); 710 return NETDEV_TX_OK; 711 712 free_skb: 713 kfree_skb(skb); 714 dev->stats.tx_dropped++; 715 return NETDEV_TX_OK; 716 } 717 718 static netdev_tx_t gre_tap_xmit(struct sk_buff *skb, 719 struct net_device *dev) 720 { 721 struct ip_tunnel *tunnel = netdev_priv(dev); 722 723 if (!pskb_inet_may_pull(skb)) 724 goto free_skb; 725 726 if (tunnel->collect_md) { 727 gre_fb_xmit(skb, dev, htons(ETH_P_TEB)); 728 return NETDEV_TX_OK; 729 } 730 731 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM))) 732 goto free_skb; 733 734 if (skb_cow_head(skb, dev->needed_headroom)) 735 goto free_skb; 736 737 __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB)); 738 return NETDEV_TX_OK; 739 740 free_skb: 741 kfree_skb(skb); 742 dev->stats.tx_dropped++; 743 return NETDEV_TX_OK; 744 } 745 746 static void ipgre_link_update(struct net_device *dev, bool set_mtu) 747 { 748 struct ip_tunnel *tunnel = netdev_priv(dev); 749 int len; 750 751 len = tunnel->tun_hlen; 752 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags); 753 len = tunnel->tun_hlen - len; 754 tunnel->hlen = tunnel->hlen + len; 755 756 if (dev->header_ops) 757 dev->hard_header_len += len; 758 else 759 dev->needed_headroom += len; 760 761 if (set_mtu) 762 dev->mtu = max_t(int, dev->mtu - len, 68); 763 764 if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) { 765 if (!(tunnel->parms.o_flags & TUNNEL_CSUM) || 766 tunnel->encap.type == TUNNEL_ENCAP_NONE) { 767 dev->features |= NETIF_F_GSO_SOFTWARE; 768 dev->hw_features |= NETIF_F_GSO_SOFTWARE; 769 } else { 770 dev->features &= ~NETIF_F_GSO_SOFTWARE; 771 dev->hw_features &= ~NETIF_F_GSO_SOFTWARE; 772 } 773 dev->features |= NETIF_F_LLTX; 774 } else { 775 dev->hw_features &= ~NETIF_F_GSO_SOFTWARE; 776 dev->features &= ~(NETIF_F_LLTX | NETIF_F_GSO_SOFTWARE); 777 } 778 } 779 780 static int ipgre_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, 781 int cmd) 782 { 783 int err; 784 785 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) { 786 if (p->iph.version != 4 || p->iph.protocol != IPPROTO_GRE || 787 p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)) || 788 ((p->i_flags | p->o_flags) & (GRE_VERSION | GRE_ROUTING))) 789 return -EINVAL; 790 } 791 792 p->i_flags = gre_flags_to_tnl_flags(p->i_flags); 793 p->o_flags = gre_flags_to_tnl_flags(p->o_flags); 794 795 err = ip_tunnel_ctl(dev, p, cmd); 796 if (err) 797 return err; 798 799 if (cmd == SIOCCHGTUNNEL) { 800 struct ip_tunnel *t = netdev_priv(dev); 801 802 t->parms.i_flags = p->i_flags; 803 t->parms.o_flags = p->o_flags; 804 805 if (strcmp(dev->rtnl_link_ops->kind, "erspan")) 806 ipgre_link_update(dev, true); 807 } 808 809 p->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags); 810 p->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags); 811 return 0; 812 } 813 814 /* Nice toy. Unfortunately, useless in real life :-) 815 It allows to construct virtual multiprotocol broadcast "LAN" 816 over the Internet, provided multicast routing is tuned. 817 818 819 I have no idea was this bicycle invented before me, 820 so that I had to set ARPHRD_IPGRE to a random value. 821 I have an impression, that Cisco could make something similar, 822 but this feature is apparently missing in IOS<=11.2(8). 823 824 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks 825 with broadcast 224.66.66.66. If you have access to mbone, play with me :-) 826 827 ping -t 255 224.66.66.66 828 829 If nobody answers, mbone does not work. 830 831 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255 832 ip addr add 10.66.66.<somewhat>/24 dev Universe 833 ifconfig Universe up 834 ifconfig Universe add fe80::<Your_real_addr>/10 835 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96 836 ftp 10.66.66.66 837 ... 838 ftp fec0:6666:6666::193.233.7.65 839 ... 840 */ 841 static int ipgre_header(struct sk_buff *skb, struct net_device *dev, 842 unsigned short type, 843 const void *daddr, const void *saddr, unsigned int len) 844 { 845 struct ip_tunnel *t = netdev_priv(dev); 846 struct iphdr *iph; 847 struct gre_base_hdr *greh; 848 849 iph = skb_push(skb, t->hlen + sizeof(*iph)); 850 greh = (struct gre_base_hdr *)(iph+1); 851 greh->flags = gre_tnl_flags_to_gre_flags(t->parms.o_flags); 852 greh->protocol = htons(type); 853 854 memcpy(iph, &t->parms.iph, sizeof(struct iphdr)); 855 856 /* Set the source hardware address. */ 857 if (saddr) 858 memcpy(&iph->saddr, saddr, 4); 859 if (daddr) 860 memcpy(&iph->daddr, daddr, 4); 861 if (iph->daddr) 862 return t->hlen + sizeof(*iph); 863 864 return -(t->hlen + sizeof(*iph)); 865 } 866 867 static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr) 868 { 869 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb); 870 memcpy(haddr, &iph->saddr, 4); 871 return 4; 872 } 873 874 static const struct header_ops ipgre_header_ops = { 875 .create = ipgre_header, 876 .parse = ipgre_header_parse, 877 }; 878 879 #ifdef CONFIG_NET_IPGRE_BROADCAST 880 static int ipgre_open(struct net_device *dev) 881 { 882 struct ip_tunnel *t = netdev_priv(dev); 883 884 if (ipv4_is_multicast(t->parms.iph.daddr)) { 885 struct flowi4 fl4; 886 struct rtable *rt; 887 888 rt = ip_route_output_gre(t->net, &fl4, 889 t->parms.iph.daddr, 890 t->parms.iph.saddr, 891 t->parms.o_key, 892 RT_TOS(t->parms.iph.tos), 893 t->parms.link); 894 if (IS_ERR(rt)) 895 return -EADDRNOTAVAIL; 896 dev = rt->dst.dev; 897 ip_rt_put(rt); 898 if (!__in_dev_get_rtnl(dev)) 899 return -EADDRNOTAVAIL; 900 t->mlink = dev->ifindex; 901 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr); 902 } 903 return 0; 904 } 905 906 static int ipgre_close(struct net_device *dev) 907 { 908 struct ip_tunnel *t = netdev_priv(dev); 909 910 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) { 911 struct in_device *in_dev; 912 in_dev = inetdev_by_index(t->net, t->mlink); 913 if (in_dev) 914 ip_mc_dec_group(in_dev, t->parms.iph.daddr); 915 } 916 return 0; 917 } 918 #endif 919 920 static const struct net_device_ops ipgre_netdev_ops = { 921 .ndo_init = ipgre_tunnel_init, 922 .ndo_uninit = ip_tunnel_uninit, 923 #ifdef CONFIG_NET_IPGRE_BROADCAST 924 .ndo_open = ipgre_open, 925 .ndo_stop = ipgre_close, 926 #endif 927 .ndo_start_xmit = ipgre_xmit, 928 .ndo_do_ioctl = ip_tunnel_ioctl, 929 .ndo_change_mtu = ip_tunnel_change_mtu, 930 .ndo_get_stats64 = dev_get_tstats64, 931 .ndo_get_iflink = ip_tunnel_get_iflink, 932 .ndo_tunnel_ctl = ipgre_tunnel_ctl, 933 }; 934 935 #define GRE_FEATURES (NETIF_F_SG | \ 936 NETIF_F_FRAGLIST | \ 937 NETIF_F_HIGHDMA | \ 938 NETIF_F_HW_CSUM) 939 940 static void ipgre_tunnel_setup(struct net_device *dev) 941 { 942 dev->netdev_ops = &ipgre_netdev_ops; 943 dev->type = ARPHRD_IPGRE; 944 ip_tunnel_setup(dev, ipgre_net_id); 945 } 946 947 static void __gre_tunnel_init(struct net_device *dev) 948 { 949 struct ip_tunnel *tunnel; 950 951 tunnel = netdev_priv(dev); 952 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags); 953 tunnel->parms.iph.protocol = IPPROTO_GRE; 954 955 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen; 956 dev->needed_headroom = tunnel->hlen + sizeof(tunnel->parms.iph); 957 958 dev->features |= GRE_FEATURES; 959 dev->hw_features |= GRE_FEATURES; 960 961 if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) { 962 /* TCP offload with GRE SEQ is not supported, nor 963 * can we support 2 levels of outer headers requiring 964 * an update. 965 */ 966 if (!(tunnel->parms.o_flags & TUNNEL_CSUM) || 967 (tunnel->encap.type == TUNNEL_ENCAP_NONE)) { 968 dev->features |= NETIF_F_GSO_SOFTWARE; 969 dev->hw_features |= NETIF_F_GSO_SOFTWARE; 970 } 971 972 /* Can use a lockless transmit, unless we generate 973 * output sequences 974 */ 975 dev->features |= NETIF_F_LLTX; 976 } 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 memcpy(dev->dev_addr, &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 (t->erspan_ver <= 2) { 1496 if (t->erspan_ver != 0 && !t->collect_md) 1497 o_flags |= TUNNEL_KEY; 1498 1499 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, t->erspan_ver)) 1500 goto nla_put_failure; 1501 1502 if (t->erspan_ver == 1) { 1503 if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, t->index)) 1504 goto nla_put_failure; 1505 } else if (t->erspan_ver == 2) { 1506 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, t->dir)) 1507 goto nla_put_failure; 1508 if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, t->hwid)) 1509 goto nla_put_failure; 1510 } 1511 } 1512 1513 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) || 1514 nla_put_be16(skb, IFLA_GRE_IFLAGS, 1515 gre_tnl_flags_to_gre_flags(p->i_flags)) || 1516 nla_put_be16(skb, IFLA_GRE_OFLAGS, 1517 gre_tnl_flags_to_gre_flags(o_flags)) || 1518 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) || 1519 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) || 1520 nla_put_in_addr(skb, IFLA_GRE_LOCAL, p->iph.saddr) || 1521 nla_put_in_addr(skb, IFLA_GRE_REMOTE, p->iph.daddr) || 1522 nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) || 1523 nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) || 1524 nla_put_u8(skb, IFLA_GRE_PMTUDISC, 1525 !!(p->iph.frag_off & htons(IP_DF))) || 1526 nla_put_u32(skb, IFLA_GRE_FWMARK, t->fwmark)) 1527 goto nla_put_failure; 1528 1529 if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE, 1530 t->encap.type) || 1531 nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT, 1532 t->encap.sport) || 1533 nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT, 1534 t->encap.dport) || 1535 nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS, 1536 t->encap.flags)) 1537 goto nla_put_failure; 1538 1539 if (nla_put_u8(skb, IFLA_GRE_IGNORE_DF, t->ignore_df)) 1540 goto nla_put_failure; 1541 1542 if (t->collect_md) { 1543 if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA)) 1544 goto nla_put_failure; 1545 } 1546 1547 return 0; 1548 1549 nla_put_failure: 1550 return -EMSGSIZE; 1551 } 1552 1553 static void erspan_setup(struct net_device *dev) 1554 { 1555 struct ip_tunnel *t = netdev_priv(dev); 1556 1557 ether_setup(dev); 1558 dev->max_mtu = 0; 1559 dev->netdev_ops = &erspan_netdev_ops; 1560 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 1561 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1562 ip_tunnel_setup(dev, erspan_net_id); 1563 t->erspan_ver = 1; 1564 } 1565 1566 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = { 1567 [IFLA_GRE_LINK] = { .type = NLA_U32 }, 1568 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 }, 1569 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 }, 1570 [IFLA_GRE_IKEY] = { .type = NLA_U32 }, 1571 [IFLA_GRE_OKEY] = { .type = NLA_U32 }, 1572 [IFLA_GRE_LOCAL] = { .len = sizeof_field(struct iphdr, saddr) }, 1573 [IFLA_GRE_REMOTE] = { .len = sizeof_field(struct iphdr, daddr) }, 1574 [IFLA_GRE_TTL] = { .type = NLA_U8 }, 1575 [IFLA_GRE_TOS] = { .type = NLA_U8 }, 1576 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 }, 1577 [IFLA_GRE_ENCAP_TYPE] = { .type = NLA_U16 }, 1578 [IFLA_GRE_ENCAP_FLAGS] = { .type = NLA_U16 }, 1579 [IFLA_GRE_ENCAP_SPORT] = { .type = NLA_U16 }, 1580 [IFLA_GRE_ENCAP_DPORT] = { .type = NLA_U16 }, 1581 [IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG }, 1582 [IFLA_GRE_IGNORE_DF] = { .type = NLA_U8 }, 1583 [IFLA_GRE_FWMARK] = { .type = NLA_U32 }, 1584 [IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 }, 1585 [IFLA_GRE_ERSPAN_VER] = { .type = NLA_U8 }, 1586 [IFLA_GRE_ERSPAN_DIR] = { .type = NLA_U8 }, 1587 [IFLA_GRE_ERSPAN_HWID] = { .type = NLA_U16 }, 1588 }; 1589 1590 static struct rtnl_link_ops ipgre_link_ops __read_mostly = { 1591 .kind = "gre", 1592 .maxtype = IFLA_GRE_MAX, 1593 .policy = ipgre_policy, 1594 .priv_size = sizeof(struct ip_tunnel), 1595 .setup = ipgre_tunnel_setup, 1596 .validate = ipgre_tunnel_validate, 1597 .newlink = ipgre_newlink, 1598 .changelink = ipgre_changelink, 1599 .dellink = ip_tunnel_dellink, 1600 .get_size = ipgre_get_size, 1601 .fill_info = ipgre_fill_info, 1602 .get_link_net = ip_tunnel_get_link_net, 1603 }; 1604 1605 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = { 1606 .kind = "gretap", 1607 .maxtype = IFLA_GRE_MAX, 1608 .policy = ipgre_policy, 1609 .priv_size = sizeof(struct ip_tunnel), 1610 .setup = ipgre_tap_setup, 1611 .validate = ipgre_tap_validate, 1612 .newlink = ipgre_newlink, 1613 .changelink = ipgre_changelink, 1614 .dellink = ip_tunnel_dellink, 1615 .get_size = ipgre_get_size, 1616 .fill_info = ipgre_fill_info, 1617 .get_link_net = ip_tunnel_get_link_net, 1618 }; 1619 1620 static struct rtnl_link_ops erspan_link_ops __read_mostly = { 1621 .kind = "erspan", 1622 .maxtype = IFLA_GRE_MAX, 1623 .policy = ipgre_policy, 1624 .priv_size = sizeof(struct ip_tunnel), 1625 .setup = erspan_setup, 1626 .validate = erspan_validate, 1627 .newlink = erspan_newlink, 1628 .changelink = erspan_changelink, 1629 .dellink = ip_tunnel_dellink, 1630 .get_size = ipgre_get_size, 1631 .fill_info = ipgre_fill_info, 1632 .get_link_net = ip_tunnel_get_link_net, 1633 }; 1634 1635 struct net_device *gretap_fb_dev_create(struct net *net, const char *name, 1636 u8 name_assign_type) 1637 { 1638 struct nlattr *tb[IFLA_MAX + 1]; 1639 struct net_device *dev; 1640 LIST_HEAD(list_kill); 1641 struct ip_tunnel *t; 1642 int err; 1643 1644 memset(&tb, 0, sizeof(tb)); 1645 1646 dev = rtnl_create_link(net, name, name_assign_type, 1647 &ipgre_tap_ops, tb, NULL); 1648 if (IS_ERR(dev)) 1649 return dev; 1650 1651 /* Configure flow based GRE device. */ 1652 t = netdev_priv(dev); 1653 t->collect_md = true; 1654 1655 err = ipgre_newlink(net, dev, tb, NULL, NULL); 1656 if (err < 0) { 1657 free_netdev(dev); 1658 return ERR_PTR(err); 1659 } 1660 1661 /* openvswitch users expect packet sizes to be unrestricted, 1662 * so set the largest MTU we can. 1663 */ 1664 err = __ip_tunnel_change_mtu(dev, IP_MAX_MTU, false); 1665 if (err) 1666 goto out; 1667 1668 err = rtnl_configure_link(dev, NULL); 1669 if (err < 0) 1670 goto out; 1671 1672 return dev; 1673 out: 1674 ip_tunnel_dellink(dev, &list_kill); 1675 unregister_netdevice_many(&list_kill); 1676 return ERR_PTR(err); 1677 } 1678 EXPORT_SYMBOL_GPL(gretap_fb_dev_create); 1679 1680 static int __net_init ipgre_tap_init_net(struct net *net) 1681 { 1682 return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, "gretap0"); 1683 } 1684 1685 static void __net_exit ipgre_tap_exit_batch_net(struct list_head *list_net) 1686 { 1687 ip_tunnel_delete_nets(list_net, gre_tap_net_id, &ipgre_tap_ops); 1688 } 1689 1690 static struct pernet_operations ipgre_tap_net_ops = { 1691 .init = ipgre_tap_init_net, 1692 .exit_batch = ipgre_tap_exit_batch_net, 1693 .id = &gre_tap_net_id, 1694 .size = sizeof(struct ip_tunnel_net), 1695 }; 1696 1697 static int __net_init erspan_init_net(struct net *net) 1698 { 1699 return ip_tunnel_init_net(net, erspan_net_id, 1700 &erspan_link_ops, "erspan0"); 1701 } 1702 1703 static void __net_exit erspan_exit_batch_net(struct list_head *net_list) 1704 { 1705 ip_tunnel_delete_nets(net_list, erspan_net_id, &erspan_link_ops); 1706 } 1707 1708 static struct pernet_operations erspan_net_ops = { 1709 .init = erspan_init_net, 1710 .exit_batch = erspan_exit_batch_net, 1711 .id = &erspan_net_id, 1712 .size = sizeof(struct ip_tunnel_net), 1713 }; 1714 1715 static int __init ipgre_init(void) 1716 { 1717 int err; 1718 1719 pr_info("GRE over IPv4 tunneling driver\n"); 1720 1721 err = register_pernet_device(&ipgre_net_ops); 1722 if (err < 0) 1723 return err; 1724 1725 err = register_pernet_device(&ipgre_tap_net_ops); 1726 if (err < 0) 1727 goto pnet_tap_failed; 1728 1729 err = register_pernet_device(&erspan_net_ops); 1730 if (err < 0) 1731 goto pnet_erspan_failed; 1732 1733 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO); 1734 if (err < 0) { 1735 pr_info("%s: can't add protocol\n", __func__); 1736 goto add_proto_failed; 1737 } 1738 1739 err = rtnl_link_register(&ipgre_link_ops); 1740 if (err < 0) 1741 goto rtnl_link_failed; 1742 1743 err = rtnl_link_register(&ipgre_tap_ops); 1744 if (err < 0) 1745 goto tap_ops_failed; 1746 1747 err = rtnl_link_register(&erspan_link_ops); 1748 if (err < 0) 1749 goto erspan_link_failed; 1750 1751 return 0; 1752 1753 erspan_link_failed: 1754 rtnl_link_unregister(&ipgre_tap_ops); 1755 tap_ops_failed: 1756 rtnl_link_unregister(&ipgre_link_ops); 1757 rtnl_link_failed: 1758 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); 1759 add_proto_failed: 1760 unregister_pernet_device(&erspan_net_ops); 1761 pnet_erspan_failed: 1762 unregister_pernet_device(&ipgre_tap_net_ops); 1763 pnet_tap_failed: 1764 unregister_pernet_device(&ipgre_net_ops); 1765 return err; 1766 } 1767 1768 static void __exit ipgre_fini(void) 1769 { 1770 rtnl_link_unregister(&ipgre_tap_ops); 1771 rtnl_link_unregister(&ipgre_link_ops); 1772 rtnl_link_unregister(&erspan_link_ops); 1773 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); 1774 unregister_pernet_device(&ipgre_tap_net_ops); 1775 unregister_pernet_device(&ipgre_net_ops); 1776 unregister_pernet_device(&erspan_net_ops); 1777 } 1778 1779 module_init(ipgre_init); 1780 module_exit(ipgre_fini); 1781 MODULE_LICENSE("GPL"); 1782 MODULE_ALIAS_RTNL_LINK("gre"); 1783 MODULE_ALIAS_RTNL_LINK("gretap"); 1784 MODULE_ALIAS_RTNL_LINK("erspan"); 1785 MODULE_ALIAS_NETDEV("gre0"); 1786 MODULE_ALIAS_NETDEV("gretap0"); 1787 MODULE_ALIAS_NETDEV("erspan0"); 1788