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 return iptunnel_handle_offloads(skb, csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE); 477 } 478 479 static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev, 480 __be16 proto) 481 { 482 struct ip_tunnel *tunnel = netdev_priv(dev); 483 struct ip_tunnel_info *tun_info; 484 const struct ip_tunnel_key *key; 485 int tunnel_hlen; 486 __be16 flags; 487 488 tun_info = skb_tunnel_info(skb); 489 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) || 490 ip_tunnel_info_af(tun_info) != AF_INET)) 491 goto err_free_skb; 492 493 key = &tun_info->key; 494 tunnel_hlen = gre_calc_hlen(key->tun_flags); 495 496 if (skb_cow_head(skb, dev->needed_headroom)) 497 goto err_free_skb; 498 499 /* Push Tunnel header. */ 500 if (gre_handle_offloads(skb, !!(tun_info->key.tun_flags & TUNNEL_CSUM))) 501 goto err_free_skb; 502 503 flags = tun_info->key.tun_flags & 504 (TUNNEL_CSUM | TUNNEL_KEY | TUNNEL_SEQ); 505 gre_build_header(skb, tunnel_hlen, flags, proto, 506 tunnel_id_to_key32(tun_info->key.tun_id), 507 (flags & TUNNEL_SEQ) ? htonl(tunnel->o_seqno++) : 0); 508 509 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen); 510 511 return; 512 513 err_free_skb: 514 kfree_skb(skb); 515 dev->stats.tx_dropped++; 516 } 517 518 static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev) 519 { 520 struct ip_tunnel *tunnel = netdev_priv(dev); 521 struct ip_tunnel_info *tun_info; 522 const struct ip_tunnel_key *key; 523 struct erspan_metadata *md; 524 bool truncate = false; 525 __be16 proto; 526 int tunnel_hlen; 527 int version; 528 int nhoff; 529 int thoff; 530 531 tun_info = skb_tunnel_info(skb); 532 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) || 533 ip_tunnel_info_af(tun_info) != AF_INET)) 534 goto err_free_skb; 535 536 key = &tun_info->key; 537 if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT)) 538 goto err_free_skb; 539 if (tun_info->options_len < sizeof(*md)) 540 goto err_free_skb; 541 md = ip_tunnel_info_opts(tun_info); 542 543 /* ERSPAN has fixed 8 byte GRE header */ 544 version = md->version; 545 tunnel_hlen = 8 + erspan_hdr_len(version); 546 547 if (skb_cow_head(skb, dev->needed_headroom)) 548 goto err_free_skb; 549 550 if (gre_handle_offloads(skb, false)) 551 goto err_free_skb; 552 553 if (skb->len > dev->mtu + dev->hard_header_len) { 554 pskb_trim(skb, dev->mtu + dev->hard_header_len); 555 truncate = true; 556 } 557 558 nhoff = skb_network_header(skb) - skb_mac_header(skb); 559 if (skb->protocol == htons(ETH_P_IP) && 560 (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff)) 561 truncate = true; 562 563 thoff = skb_transport_header(skb) - skb_mac_header(skb); 564 if (skb->protocol == htons(ETH_P_IPV6) && 565 (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff)) 566 truncate = true; 567 568 if (version == 1) { 569 erspan_build_header(skb, ntohl(tunnel_id_to_key32(key->tun_id)), 570 ntohl(md->u.index), truncate, true); 571 proto = htons(ETH_P_ERSPAN); 572 } else if (version == 2) { 573 erspan_build_header_v2(skb, 574 ntohl(tunnel_id_to_key32(key->tun_id)), 575 md->u.md2.dir, 576 get_hwid(&md->u.md2), 577 truncate, true); 578 proto = htons(ETH_P_ERSPAN2); 579 } else { 580 goto err_free_skb; 581 } 582 583 gre_build_header(skb, 8, TUNNEL_SEQ, 584 proto, 0, htonl(tunnel->o_seqno++)); 585 586 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen); 587 588 return; 589 590 err_free_skb: 591 kfree_skb(skb); 592 dev->stats.tx_dropped++; 593 } 594 595 static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb) 596 { 597 struct ip_tunnel_info *info = skb_tunnel_info(skb); 598 const struct ip_tunnel_key *key; 599 struct rtable *rt; 600 struct flowi4 fl4; 601 602 if (ip_tunnel_info_af(info) != AF_INET) 603 return -EINVAL; 604 605 key = &info->key; 606 ip_tunnel_init_flow(&fl4, IPPROTO_GRE, key->u.ipv4.dst, key->u.ipv4.src, 607 tunnel_id_to_key32(key->tun_id), 608 key->tos & ~INET_ECN_MASK, 0, skb->mark, 609 skb_get_hash(skb)); 610 rt = ip_route_output_key(dev_net(dev), &fl4); 611 if (IS_ERR(rt)) 612 return PTR_ERR(rt); 613 614 ip_rt_put(rt); 615 info->key.u.ipv4.src = fl4.saddr; 616 return 0; 617 } 618 619 static netdev_tx_t ipgre_xmit(struct sk_buff *skb, 620 struct net_device *dev) 621 { 622 struct ip_tunnel *tunnel = netdev_priv(dev); 623 const struct iphdr *tnl_params; 624 625 if (!pskb_inet_may_pull(skb)) 626 goto free_skb; 627 628 if (tunnel->collect_md) { 629 gre_fb_xmit(skb, dev, skb->protocol); 630 return NETDEV_TX_OK; 631 } 632 633 if (dev->header_ops) { 634 const int pull_len = tunnel->hlen + sizeof(struct iphdr); 635 636 if (skb_cow_head(skb, 0)) 637 goto free_skb; 638 639 tnl_params = (const struct iphdr *)skb->data; 640 641 if (pull_len > skb_transport_offset(skb)) 642 goto free_skb; 643 644 /* Pull skb since ip_tunnel_xmit() needs skb->data pointing 645 * to gre header. 646 */ 647 skb_pull(skb, pull_len); 648 skb_reset_mac_header(skb); 649 } else { 650 if (skb_cow_head(skb, dev->needed_headroom)) 651 goto free_skb; 652 653 tnl_params = &tunnel->parms.iph; 654 } 655 656 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM))) 657 goto free_skb; 658 659 __gre_xmit(skb, dev, tnl_params, skb->protocol); 660 return NETDEV_TX_OK; 661 662 free_skb: 663 kfree_skb(skb); 664 dev->stats.tx_dropped++; 665 return NETDEV_TX_OK; 666 } 667 668 static netdev_tx_t erspan_xmit(struct sk_buff *skb, 669 struct net_device *dev) 670 { 671 struct ip_tunnel *tunnel = netdev_priv(dev); 672 bool truncate = false; 673 __be16 proto; 674 675 if (!pskb_inet_may_pull(skb)) 676 goto free_skb; 677 678 if (tunnel->collect_md) { 679 erspan_fb_xmit(skb, dev); 680 return NETDEV_TX_OK; 681 } 682 683 if (gre_handle_offloads(skb, false)) 684 goto free_skb; 685 686 if (skb_cow_head(skb, dev->needed_headroom)) 687 goto free_skb; 688 689 if (skb->len > dev->mtu + dev->hard_header_len) { 690 pskb_trim(skb, dev->mtu + dev->hard_header_len); 691 truncate = true; 692 } 693 694 /* Push ERSPAN header */ 695 if (tunnel->erspan_ver == 0) { 696 proto = htons(ETH_P_ERSPAN); 697 tunnel->parms.o_flags &= ~TUNNEL_SEQ; 698 } else if (tunnel->erspan_ver == 1) { 699 erspan_build_header(skb, ntohl(tunnel->parms.o_key), 700 tunnel->index, 701 truncate, true); 702 proto = htons(ETH_P_ERSPAN); 703 } else if (tunnel->erspan_ver == 2) { 704 erspan_build_header_v2(skb, ntohl(tunnel->parms.o_key), 705 tunnel->dir, tunnel->hwid, 706 truncate, true); 707 proto = htons(ETH_P_ERSPAN2); 708 } else { 709 goto free_skb; 710 } 711 712 tunnel->parms.o_flags &= ~TUNNEL_KEY; 713 __gre_xmit(skb, dev, &tunnel->parms.iph, proto); 714 return NETDEV_TX_OK; 715 716 free_skb: 717 kfree_skb(skb); 718 dev->stats.tx_dropped++; 719 return NETDEV_TX_OK; 720 } 721 722 static netdev_tx_t gre_tap_xmit(struct sk_buff *skb, 723 struct net_device *dev) 724 { 725 struct ip_tunnel *tunnel = netdev_priv(dev); 726 727 if (!pskb_inet_may_pull(skb)) 728 goto free_skb; 729 730 if (tunnel->collect_md) { 731 gre_fb_xmit(skb, dev, htons(ETH_P_TEB)); 732 return NETDEV_TX_OK; 733 } 734 735 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM))) 736 goto free_skb; 737 738 if (skb_cow_head(skb, dev->needed_headroom)) 739 goto free_skb; 740 741 __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB)); 742 return NETDEV_TX_OK; 743 744 free_skb: 745 kfree_skb(skb); 746 dev->stats.tx_dropped++; 747 return NETDEV_TX_OK; 748 } 749 750 static void ipgre_link_update(struct net_device *dev, bool set_mtu) 751 { 752 struct ip_tunnel *tunnel = netdev_priv(dev); 753 int len; 754 755 len = tunnel->tun_hlen; 756 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags); 757 len = tunnel->tun_hlen - len; 758 tunnel->hlen = tunnel->hlen + len; 759 760 if (dev->header_ops) 761 dev->hard_header_len += len; 762 else 763 dev->needed_headroom += len; 764 765 if (set_mtu) 766 dev->mtu = max_t(int, dev->mtu - len, 68); 767 768 if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) { 769 if (!(tunnel->parms.o_flags & TUNNEL_CSUM) || 770 tunnel->encap.type == TUNNEL_ENCAP_NONE) { 771 dev->features |= NETIF_F_GSO_SOFTWARE; 772 dev->hw_features |= NETIF_F_GSO_SOFTWARE; 773 } else { 774 dev->features &= ~NETIF_F_GSO_SOFTWARE; 775 dev->hw_features &= ~NETIF_F_GSO_SOFTWARE; 776 } 777 dev->features |= NETIF_F_LLTX; 778 } else { 779 dev->hw_features &= ~NETIF_F_GSO_SOFTWARE; 780 dev->features &= ~(NETIF_F_LLTX | NETIF_F_GSO_SOFTWARE); 781 } 782 } 783 784 static int ipgre_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, 785 int cmd) 786 { 787 int err; 788 789 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) { 790 if (p->iph.version != 4 || p->iph.protocol != IPPROTO_GRE || 791 p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)) || 792 ((p->i_flags | p->o_flags) & (GRE_VERSION | GRE_ROUTING))) 793 return -EINVAL; 794 } 795 796 p->i_flags = gre_flags_to_tnl_flags(p->i_flags); 797 p->o_flags = gre_flags_to_tnl_flags(p->o_flags); 798 799 err = ip_tunnel_ctl(dev, p, cmd); 800 if (err) 801 return err; 802 803 if (cmd == SIOCCHGTUNNEL) { 804 struct ip_tunnel *t = netdev_priv(dev); 805 806 t->parms.i_flags = p->i_flags; 807 t->parms.o_flags = p->o_flags; 808 809 if (strcmp(dev->rtnl_link_ops->kind, "erspan")) 810 ipgre_link_update(dev, true); 811 } 812 813 p->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags); 814 p->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags); 815 return 0; 816 } 817 818 /* Nice toy. Unfortunately, useless in real life :-) 819 It allows to construct virtual multiprotocol broadcast "LAN" 820 over the Internet, provided multicast routing is tuned. 821 822 823 I have no idea was this bicycle invented before me, 824 so that I had to set ARPHRD_IPGRE to a random value. 825 I have an impression, that Cisco could make something similar, 826 but this feature is apparently missing in IOS<=11.2(8). 827 828 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks 829 with broadcast 224.66.66.66. If you have access to mbone, play with me :-) 830 831 ping -t 255 224.66.66.66 832 833 If nobody answers, mbone does not work. 834 835 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255 836 ip addr add 10.66.66.<somewhat>/24 dev Universe 837 ifconfig Universe up 838 ifconfig Universe add fe80::<Your_real_addr>/10 839 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96 840 ftp 10.66.66.66 841 ... 842 ftp fec0:6666:6666::193.233.7.65 843 ... 844 */ 845 static int ipgre_header(struct sk_buff *skb, struct net_device *dev, 846 unsigned short type, 847 const void *daddr, const void *saddr, unsigned int len) 848 { 849 struct ip_tunnel *t = netdev_priv(dev); 850 struct iphdr *iph; 851 struct gre_base_hdr *greh; 852 853 iph = skb_push(skb, t->hlen + sizeof(*iph)); 854 greh = (struct gre_base_hdr *)(iph+1); 855 greh->flags = gre_tnl_flags_to_gre_flags(t->parms.o_flags); 856 greh->protocol = htons(type); 857 858 memcpy(iph, &t->parms.iph, sizeof(struct iphdr)); 859 860 /* Set the source hardware address. */ 861 if (saddr) 862 memcpy(&iph->saddr, saddr, 4); 863 if (daddr) 864 memcpy(&iph->daddr, daddr, 4); 865 if (iph->daddr) 866 return t->hlen + sizeof(*iph); 867 868 return -(t->hlen + sizeof(*iph)); 869 } 870 871 static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr) 872 { 873 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb); 874 memcpy(haddr, &iph->saddr, 4); 875 return 4; 876 } 877 878 static const struct header_ops ipgre_header_ops = { 879 .create = ipgre_header, 880 .parse = ipgre_header_parse, 881 }; 882 883 #ifdef CONFIG_NET_IPGRE_BROADCAST 884 static int ipgre_open(struct net_device *dev) 885 { 886 struct ip_tunnel *t = netdev_priv(dev); 887 888 if (ipv4_is_multicast(t->parms.iph.daddr)) { 889 struct flowi4 fl4; 890 struct rtable *rt; 891 892 rt = ip_route_output_gre(t->net, &fl4, 893 t->parms.iph.daddr, 894 t->parms.iph.saddr, 895 t->parms.o_key, 896 RT_TOS(t->parms.iph.tos), 897 t->parms.link); 898 if (IS_ERR(rt)) 899 return -EADDRNOTAVAIL; 900 dev = rt->dst.dev; 901 ip_rt_put(rt); 902 if (!__in_dev_get_rtnl(dev)) 903 return -EADDRNOTAVAIL; 904 t->mlink = dev->ifindex; 905 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr); 906 } 907 return 0; 908 } 909 910 static int ipgre_close(struct net_device *dev) 911 { 912 struct ip_tunnel *t = netdev_priv(dev); 913 914 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) { 915 struct in_device *in_dev; 916 in_dev = inetdev_by_index(t->net, t->mlink); 917 if (in_dev) 918 ip_mc_dec_group(in_dev, t->parms.iph.daddr); 919 } 920 return 0; 921 } 922 #endif 923 924 static const struct net_device_ops ipgre_netdev_ops = { 925 .ndo_init = ipgre_tunnel_init, 926 .ndo_uninit = ip_tunnel_uninit, 927 #ifdef CONFIG_NET_IPGRE_BROADCAST 928 .ndo_open = ipgre_open, 929 .ndo_stop = ipgre_close, 930 #endif 931 .ndo_start_xmit = ipgre_xmit, 932 .ndo_siocdevprivate = ip_tunnel_siocdevprivate, 933 .ndo_change_mtu = ip_tunnel_change_mtu, 934 .ndo_get_stats64 = dev_get_tstats64, 935 .ndo_get_iflink = ip_tunnel_get_iflink, 936 .ndo_tunnel_ctl = ipgre_tunnel_ctl, 937 }; 938 939 #define GRE_FEATURES (NETIF_F_SG | \ 940 NETIF_F_FRAGLIST | \ 941 NETIF_F_HIGHDMA | \ 942 NETIF_F_HW_CSUM) 943 944 static void ipgre_tunnel_setup(struct net_device *dev) 945 { 946 dev->netdev_ops = &ipgre_netdev_ops; 947 dev->type = ARPHRD_IPGRE; 948 ip_tunnel_setup(dev, ipgre_net_id); 949 } 950 951 static void __gre_tunnel_init(struct net_device *dev) 952 { 953 struct ip_tunnel *tunnel; 954 955 tunnel = netdev_priv(dev); 956 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags); 957 tunnel->parms.iph.protocol = IPPROTO_GRE; 958 959 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen; 960 dev->needed_headroom = tunnel->hlen + sizeof(tunnel->parms.iph); 961 962 dev->features |= GRE_FEATURES; 963 dev->hw_features |= GRE_FEATURES; 964 965 if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) { 966 /* TCP offload with GRE SEQ is not supported, nor 967 * can we support 2 levels of outer headers requiring 968 * an update. 969 */ 970 if (!(tunnel->parms.o_flags & TUNNEL_CSUM) || 971 (tunnel->encap.type == TUNNEL_ENCAP_NONE)) { 972 dev->features |= NETIF_F_GSO_SOFTWARE; 973 dev->hw_features |= NETIF_F_GSO_SOFTWARE; 974 } 975 976 /* Can use a lockless transmit, unless we generate 977 * output sequences 978 */ 979 dev->features |= NETIF_F_LLTX; 980 } 981 } 982 983 static int ipgre_tunnel_init(struct net_device *dev) 984 { 985 struct ip_tunnel *tunnel = netdev_priv(dev); 986 struct iphdr *iph = &tunnel->parms.iph; 987 988 __gre_tunnel_init(dev); 989 990 __dev_addr_set(dev, &iph->saddr, 4); 991 memcpy(dev->broadcast, &iph->daddr, 4); 992 993 dev->flags = IFF_NOARP; 994 netif_keep_dst(dev); 995 dev->addr_len = 4; 996 997 if (iph->daddr && !tunnel->collect_md) { 998 #ifdef CONFIG_NET_IPGRE_BROADCAST 999 if (ipv4_is_multicast(iph->daddr)) { 1000 if (!iph->saddr) 1001 return -EINVAL; 1002 dev->flags = IFF_BROADCAST; 1003 dev->header_ops = &ipgre_header_ops; 1004 dev->hard_header_len = tunnel->hlen + sizeof(*iph); 1005 dev->needed_headroom = 0; 1006 } 1007 #endif 1008 } else if (!tunnel->collect_md) { 1009 dev->header_ops = &ipgre_header_ops; 1010 dev->hard_header_len = tunnel->hlen + sizeof(*iph); 1011 dev->needed_headroom = 0; 1012 } 1013 1014 return ip_tunnel_init(dev); 1015 } 1016 1017 static const struct gre_protocol ipgre_protocol = { 1018 .handler = gre_rcv, 1019 .err_handler = gre_err, 1020 }; 1021 1022 static int __net_init ipgre_init_net(struct net *net) 1023 { 1024 return ip_tunnel_init_net(net, ipgre_net_id, &ipgre_link_ops, NULL); 1025 } 1026 1027 static void __net_exit ipgre_exit_batch_net(struct list_head *list_net) 1028 { 1029 ip_tunnel_delete_nets(list_net, ipgre_net_id, &ipgre_link_ops); 1030 } 1031 1032 static struct pernet_operations ipgre_net_ops = { 1033 .init = ipgre_init_net, 1034 .exit_batch = ipgre_exit_batch_net, 1035 .id = &ipgre_net_id, 1036 .size = sizeof(struct ip_tunnel_net), 1037 }; 1038 1039 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[], 1040 struct netlink_ext_ack *extack) 1041 { 1042 __be16 flags; 1043 1044 if (!data) 1045 return 0; 1046 1047 flags = 0; 1048 if (data[IFLA_GRE_IFLAGS]) 1049 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); 1050 if (data[IFLA_GRE_OFLAGS]) 1051 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); 1052 if (flags & (GRE_VERSION|GRE_ROUTING)) 1053 return -EINVAL; 1054 1055 if (data[IFLA_GRE_COLLECT_METADATA] && 1056 data[IFLA_GRE_ENCAP_TYPE] && 1057 nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]) != TUNNEL_ENCAP_NONE) 1058 return -EINVAL; 1059 1060 return 0; 1061 } 1062 1063 static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[], 1064 struct netlink_ext_ack *extack) 1065 { 1066 __be32 daddr; 1067 1068 if (tb[IFLA_ADDRESS]) { 1069 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) 1070 return -EINVAL; 1071 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) 1072 return -EADDRNOTAVAIL; 1073 } 1074 1075 if (!data) 1076 goto out; 1077 1078 if (data[IFLA_GRE_REMOTE]) { 1079 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4); 1080 if (!daddr) 1081 return -EINVAL; 1082 } 1083 1084 out: 1085 return ipgre_tunnel_validate(tb, data, extack); 1086 } 1087 1088 static int erspan_validate(struct nlattr *tb[], struct nlattr *data[], 1089 struct netlink_ext_ack *extack) 1090 { 1091 __be16 flags = 0; 1092 int ret; 1093 1094 if (!data) 1095 return 0; 1096 1097 ret = ipgre_tap_validate(tb, data, extack); 1098 if (ret) 1099 return ret; 1100 1101 if (data[IFLA_GRE_ERSPAN_VER] && 1102 nla_get_u8(data[IFLA_GRE_ERSPAN_VER]) == 0) 1103 return 0; 1104 1105 /* ERSPAN type II/III should only have GRE sequence and key flag */ 1106 if (data[IFLA_GRE_OFLAGS]) 1107 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); 1108 if (data[IFLA_GRE_IFLAGS]) 1109 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); 1110 if (!data[IFLA_GRE_COLLECT_METADATA] && 1111 flags != (GRE_SEQ | GRE_KEY)) 1112 return -EINVAL; 1113 1114 /* ERSPAN Session ID only has 10-bit. Since we reuse 1115 * 32-bit key field as ID, check it's range. 1116 */ 1117 if (data[IFLA_GRE_IKEY] && 1118 (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK)) 1119 return -EINVAL; 1120 1121 if (data[IFLA_GRE_OKEY] && 1122 (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK)) 1123 return -EINVAL; 1124 1125 return 0; 1126 } 1127 1128 static int ipgre_netlink_parms(struct net_device *dev, 1129 struct nlattr *data[], 1130 struct nlattr *tb[], 1131 struct ip_tunnel_parm *parms, 1132 __u32 *fwmark) 1133 { 1134 struct ip_tunnel *t = netdev_priv(dev); 1135 1136 memset(parms, 0, sizeof(*parms)); 1137 1138 parms->iph.protocol = IPPROTO_GRE; 1139 1140 if (!data) 1141 return 0; 1142 1143 if (data[IFLA_GRE_LINK]) 1144 parms->link = nla_get_u32(data[IFLA_GRE_LINK]); 1145 1146 if (data[IFLA_GRE_IFLAGS]) 1147 parms->i_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_IFLAGS])); 1148 1149 if (data[IFLA_GRE_OFLAGS]) 1150 parms->o_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_OFLAGS])); 1151 1152 if (data[IFLA_GRE_IKEY]) 1153 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]); 1154 1155 if (data[IFLA_GRE_OKEY]) 1156 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]); 1157 1158 if (data[IFLA_GRE_LOCAL]) 1159 parms->iph.saddr = nla_get_in_addr(data[IFLA_GRE_LOCAL]); 1160 1161 if (data[IFLA_GRE_REMOTE]) 1162 parms->iph.daddr = nla_get_in_addr(data[IFLA_GRE_REMOTE]); 1163 1164 if (data[IFLA_GRE_TTL]) 1165 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]); 1166 1167 if (data[IFLA_GRE_TOS]) 1168 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]); 1169 1170 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC])) { 1171 if (t->ignore_df) 1172 return -EINVAL; 1173 parms->iph.frag_off = htons(IP_DF); 1174 } 1175 1176 if (data[IFLA_GRE_COLLECT_METADATA]) { 1177 t->collect_md = true; 1178 if (dev->type == ARPHRD_IPGRE) 1179 dev->type = ARPHRD_NONE; 1180 } 1181 1182 if (data[IFLA_GRE_IGNORE_DF]) { 1183 if (nla_get_u8(data[IFLA_GRE_IGNORE_DF]) 1184 && (parms->iph.frag_off & htons(IP_DF))) 1185 return -EINVAL; 1186 t->ignore_df = !!nla_get_u8(data[IFLA_GRE_IGNORE_DF]); 1187 } 1188 1189 if (data[IFLA_GRE_FWMARK]) 1190 *fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]); 1191 1192 return 0; 1193 } 1194 1195 static int erspan_netlink_parms(struct net_device *dev, 1196 struct nlattr *data[], 1197 struct nlattr *tb[], 1198 struct ip_tunnel_parm *parms, 1199 __u32 *fwmark) 1200 { 1201 struct ip_tunnel *t = netdev_priv(dev); 1202 int err; 1203 1204 err = ipgre_netlink_parms(dev, data, tb, parms, fwmark); 1205 if (err) 1206 return err; 1207 if (!data) 1208 return 0; 1209 1210 if (data[IFLA_GRE_ERSPAN_VER]) { 1211 t->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]); 1212 1213 if (t->erspan_ver > 2) 1214 return -EINVAL; 1215 } 1216 1217 if (t->erspan_ver == 1) { 1218 if (data[IFLA_GRE_ERSPAN_INDEX]) { 1219 t->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]); 1220 if (t->index & ~INDEX_MASK) 1221 return -EINVAL; 1222 } 1223 } else if (t->erspan_ver == 2) { 1224 if (data[IFLA_GRE_ERSPAN_DIR]) { 1225 t->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]); 1226 if (t->dir & ~(DIR_MASK >> DIR_OFFSET)) 1227 return -EINVAL; 1228 } 1229 if (data[IFLA_GRE_ERSPAN_HWID]) { 1230 t->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]); 1231 if (t->hwid & ~(HWID_MASK >> HWID_OFFSET)) 1232 return -EINVAL; 1233 } 1234 } 1235 1236 return 0; 1237 } 1238 1239 /* This function returns true when ENCAP attributes are present in the nl msg */ 1240 static bool ipgre_netlink_encap_parms(struct nlattr *data[], 1241 struct ip_tunnel_encap *ipencap) 1242 { 1243 bool ret = false; 1244 1245 memset(ipencap, 0, sizeof(*ipencap)); 1246 1247 if (!data) 1248 return ret; 1249 1250 if (data[IFLA_GRE_ENCAP_TYPE]) { 1251 ret = true; 1252 ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]); 1253 } 1254 1255 if (data[IFLA_GRE_ENCAP_FLAGS]) { 1256 ret = true; 1257 ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]); 1258 } 1259 1260 if (data[IFLA_GRE_ENCAP_SPORT]) { 1261 ret = true; 1262 ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]); 1263 } 1264 1265 if (data[IFLA_GRE_ENCAP_DPORT]) { 1266 ret = true; 1267 ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]); 1268 } 1269 1270 return ret; 1271 } 1272 1273 static int gre_tap_init(struct net_device *dev) 1274 { 1275 __gre_tunnel_init(dev); 1276 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1277 netif_keep_dst(dev); 1278 1279 return ip_tunnel_init(dev); 1280 } 1281 1282 static const struct net_device_ops gre_tap_netdev_ops = { 1283 .ndo_init = gre_tap_init, 1284 .ndo_uninit = ip_tunnel_uninit, 1285 .ndo_start_xmit = gre_tap_xmit, 1286 .ndo_set_mac_address = eth_mac_addr, 1287 .ndo_validate_addr = eth_validate_addr, 1288 .ndo_change_mtu = ip_tunnel_change_mtu, 1289 .ndo_get_stats64 = dev_get_tstats64, 1290 .ndo_get_iflink = ip_tunnel_get_iflink, 1291 .ndo_fill_metadata_dst = gre_fill_metadata_dst, 1292 }; 1293 1294 static int erspan_tunnel_init(struct net_device *dev) 1295 { 1296 struct ip_tunnel *tunnel = netdev_priv(dev); 1297 1298 if (tunnel->erspan_ver == 0) 1299 tunnel->tun_hlen = 4; /* 4-byte GRE hdr. */ 1300 else 1301 tunnel->tun_hlen = 8; /* 8-byte GRE hdr. */ 1302 1303 tunnel->parms.iph.protocol = IPPROTO_GRE; 1304 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen + 1305 erspan_hdr_len(tunnel->erspan_ver); 1306 1307 dev->features |= GRE_FEATURES; 1308 dev->hw_features |= GRE_FEATURES; 1309 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1310 netif_keep_dst(dev); 1311 1312 return ip_tunnel_init(dev); 1313 } 1314 1315 static const struct net_device_ops erspan_netdev_ops = { 1316 .ndo_init = erspan_tunnel_init, 1317 .ndo_uninit = ip_tunnel_uninit, 1318 .ndo_start_xmit = erspan_xmit, 1319 .ndo_set_mac_address = eth_mac_addr, 1320 .ndo_validate_addr = eth_validate_addr, 1321 .ndo_change_mtu = ip_tunnel_change_mtu, 1322 .ndo_get_stats64 = dev_get_tstats64, 1323 .ndo_get_iflink = ip_tunnel_get_iflink, 1324 .ndo_fill_metadata_dst = gre_fill_metadata_dst, 1325 }; 1326 1327 static void ipgre_tap_setup(struct net_device *dev) 1328 { 1329 ether_setup(dev); 1330 dev->max_mtu = 0; 1331 dev->netdev_ops = &gre_tap_netdev_ops; 1332 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 1333 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1334 ip_tunnel_setup(dev, gre_tap_net_id); 1335 } 1336 1337 static int 1338 ipgre_newlink_encap_setup(struct net_device *dev, struct nlattr *data[]) 1339 { 1340 struct ip_tunnel_encap ipencap; 1341 1342 if (ipgre_netlink_encap_parms(data, &ipencap)) { 1343 struct ip_tunnel *t = netdev_priv(dev); 1344 int err = ip_tunnel_encap_setup(t, &ipencap); 1345 1346 if (err < 0) 1347 return err; 1348 } 1349 1350 return 0; 1351 } 1352 1353 static int ipgre_newlink(struct net *src_net, struct net_device *dev, 1354 struct nlattr *tb[], struct nlattr *data[], 1355 struct netlink_ext_ack *extack) 1356 { 1357 struct ip_tunnel_parm p; 1358 __u32 fwmark = 0; 1359 int err; 1360 1361 err = ipgre_newlink_encap_setup(dev, data); 1362 if (err) 1363 return err; 1364 1365 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark); 1366 if (err < 0) 1367 return err; 1368 return ip_tunnel_newlink(dev, tb, &p, fwmark); 1369 } 1370 1371 static int erspan_newlink(struct net *src_net, struct net_device *dev, 1372 struct nlattr *tb[], struct nlattr *data[], 1373 struct netlink_ext_ack *extack) 1374 { 1375 struct ip_tunnel_parm p; 1376 __u32 fwmark = 0; 1377 int err; 1378 1379 err = ipgre_newlink_encap_setup(dev, data); 1380 if (err) 1381 return err; 1382 1383 err = erspan_netlink_parms(dev, data, tb, &p, &fwmark); 1384 if (err) 1385 return err; 1386 return ip_tunnel_newlink(dev, tb, &p, fwmark); 1387 } 1388 1389 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[], 1390 struct nlattr *data[], 1391 struct netlink_ext_ack *extack) 1392 { 1393 struct ip_tunnel *t = netdev_priv(dev); 1394 __u32 fwmark = t->fwmark; 1395 struct ip_tunnel_parm p; 1396 int err; 1397 1398 err = ipgre_newlink_encap_setup(dev, data); 1399 if (err) 1400 return err; 1401 1402 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark); 1403 if (err < 0) 1404 return err; 1405 1406 err = ip_tunnel_changelink(dev, tb, &p, fwmark); 1407 if (err < 0) 1408 return err; 1409 1410 t->parms.i_flags = p.i_flags; 1411 t->parms.o_flags = p.o_flags; 1412 1413 ipgre_link_update(dev, !tb[IFLA_MTU]); 1414 1415 return 0; 1416 } 1417 1418 static int erspan_changelink(struct net_device *dev, struct nlattr *tb[], 1419 struct nlattr *data[], 1420 struct netlink_ext_ack *extack) 1421 { 1422 struct ip_tunnel *t = netdev_priv(dev); 1423 __u32 fwmark = t->fwmark; 1424 struct ip_tunnel_parm p; 1425 int err; 1426 1427 err = ipgre_newlink_encap_setup(dev, data); 1428 if (err) 1429 return err; 1430 1431 err = erspan_netlink_parms(dev, data, tb, &p, &fwmark); 1432 if (err < 0) 1433 return err; 1434 1435 err = ip_tunnel_changelink(dev, tb, &p, fwmark); 1436 if (err < 0) 1437 return err; 1438 1439 t->parms.i_flags = p.i_flags; 1440 t->parms.o_flags = p.o_flags; 1441 1442 return 0; 1443 } 1444 1445 static size_t ipgre_get_size(const struct net_device *dev) 1446 { 1447 return 1448 /* IFLA_GRE_LINK */ 1449 nla_total_size(4) + 1450 /* IFLA_GRE_IFLAGS */ 1451 nla_total_size(2) + 1452 /* IFLA_GRE_OFLAGS */ 1453 nla_total_size(2) + 1454 /* IFLA_GRE_IKEY */ 1455 nla_total_size(4) + 1456 /* IFLA_GRE_OKEY */ 1457 nla_total_size(4) + 1458 /* IFLA_GRE_LOCAL */ 1459 nla_total_size(4) + 1460 /* IFLA_GRE_REMOTE */ 1461 nla_total_size(4) + 1462 /* IFLA_GRE_TTL */ 1463 nla_total_size(1) + 1464 /* IFLA_GRE_TOS */ 1465 nla_total_size(1) + 1466 /* IFLA_GRE_PMTUDISC */ 1467 nla_total_size(1) + 1468 /* IFLA_GRE_ENCAP_TYPE */ 1469 nla_total_size(2) + 1470 /* IFLA_GRE_ENCAP_FLAGS */ 1471 nla_total_size(2) + 1472 /* IFLA_GRE_ENCAP_SPORT */ 1473 nla_total_size(2) + 1474 /* IFLA_GRE_ENCAP_DPORT */ 1475 nla_total_size(2) + 1476 /* IFLA_GRE_COLLECT_METADATA */ 1477 nla_total_size(0) + 1478 /* IFLA_GRE_IGNORE_DF */ 1479 nla_total_size(1) + 1480 /* IFLA_GRE_FWMARK */ 1481 nla_total_size(4) + 1482 /* IFLA_GRE_ERSPAN_INDEX */ 1483 nla_total_size(4) + 1484 /* IFLA_GRE_ERSPAN_VER */ 1485 nla_total_size(1) + 1486 /* IFLA_GRE_ERSPAN_DIR */ 1487 nla_total_size(1) + 1488 /* IFLA_GRE_ERSPAN_HWID */ 1489 nla_total_size(2) + 1490 0; 1491 } 1492 1493 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev) 1494 { 1495 struct ip_tunnel *t = netdev_priv(dev); 1496 struct ip_tunnel_parm *p = &t->parms; 1497 __be16 o_flags = p->o_flags; 1498 1499 if (t->erspan_ver <= 2) { 1500 if (t->erspan_ver != 0 && !t->collect_md) 1501 o_flags |= TUNNEL_KEY; 1502 1503 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, t->erspan_ver)) 1504 goto nla_put_failure; 1505 1506 if (t->erspan_ver == 1) { 1507 if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, t->index)) 1508 goto nla_put_failure; 1509 } else if (t->erspan_ver == 2) { 1510 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, t->dir)) 1511 goto nla_put_failure; 1512 if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, t->hwid)) 1513 goto nla_put_failure; 1514 } 1515 } 1516 1517 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) || 1518 nla_put_be16(skb, IFLA_GRE_IFLAGS, 1519 gre_tnl_flags_to_gre_flags(p->i_flags)) || 1520 nla_put_be16(skb, IFLA_GRE_OFLAGS, 1521 gre_tnl_flags_to_gre_flags(o_flags)) || 1522 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) || 1523 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) || 1524 nla_put_in_addr(skb, IFLA_GRE_LOCAL, p->iph.saddr) || 1525 nla_put_in_addr(skb, IFLA_GRE_REMOTE, p->iph.daddr) || 1526 nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) || 1527 nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) || 1528 nla_put_u8(skb, IFLA_GRE_PMTUDISC, 1529 !!(p->iph.frag_off & htons(IP_DF))) || 1530 nla_put_u32(skb, IFLA_GRE_FWMARK, t->fwmark)) 1531 goto nla_put_failure; 1532 1533 if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE, 1534 t->encap.type) || 1535 nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT, 1536 t->encap.sport) || 1537 nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT, 1538 t->encap.dport) || 1539 nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS, 1540 t->encap.flags)) 1541 goto nla_put_failure; 1542 1543 if (nla_put_u8(skb, IFLA_GRE_IGNORE_DF, t->ignore_df)) 1544 goto nla_put_failure; 1545 1546 if (t->collect_md) { 1547 if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA)) 1548 goto nla_put_failure; 1549 } 1550 1551 return 0; 1552 1553 nla_put_failure: 1554 return -EMSGSIZE; 1555 } 1556 1557 static void erspan_setup(struct net_device *dev) 1558 { 1559 struct ip_tunnel *t = netdev_priv(dev); 1560 1561 ether_setup(dev); 1562 dev->max_mtu = 0; 1563 dev->netdev_ops = &erspan_netdev_ops; 1564 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 1565 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1566 ip_tunnel_setup(dev, erspan_net_id); 1567 t->erspan_ver = 1; 1568 } 1569 1570 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = { 1571 [IFLA_GRE_LINK] = { .type = NLA_U32 }, 1572 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 }, 1573 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 }, 1574 [IFLA_GRE_IKEY] = { .type = NLA_U32 }, 1575 [IFLA_GRE_OKEY] = { .type = NLA_U32 }, 1576 [IFLA_GRE_LOCAL] = { .len = sizeof_field(struct iphdr, saddr) }, 1577 [IFLA_GRE_REMOTE] = { .len = sizeof_field(struct iphdr, daddr) }, 1578 [IFLA_GRE_TTL] = { .type = NLA_U8 }, 1579 [IFLA_GRE_TOS] = { .type = NLA_U8 }, 1580 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 }, 1581 [IFLA_GRE_ENCAP_TYPE] = { .type = NLA_U16 }, 1582 [IFLA_GRE_ENCAP_FLAGS] = { .type = NLA_U16 }, 1583 [IFLA_GRE_ENCAP_SPORT] = { .type = NLA_U16 }, 1584 [IFLA_GRE_ENCAP_DPORT] = { .type = NLA_U16 }, 1585 [IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG }, 1586 [IFLA_GRE_IGNORE_DF] = { .type = NLA_U8 }, 1587 [IFLA_GRE_FWMARK] = { .type = NLA_U32 }, 1588 [IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 }, 1589 [IFLA_GRE_ERSPAN_VER] = { .type = NLA_U8 }, 1590 [IFLA_GRE_ERSPAN_DIR] = { .type = NLA_U8 }, 1591 [IFLA_GRE_ERSPAN_HWID] = { .type = NLA_U16 }, 1592 }; 1593 1594 static struct rtnl_link_ops ipgre_link_ops __read_mostly = { 1595 .kind = "gre", 1596 .maxtype = IFLA_GRE_MAX, 1597 .policy = ipgre_policy, 1598 .priv_size = sizeof(struct ip_tunnel), 1599 .setup = ipgre_tunnel_setup, 1600 .validate = ipgre_tunnel_validate, 1601 .newlink = ipgre_newlink, 1602 .changelink = ipgre_changelink, 1603 .dellink = ip_tunnel_dellink, 1604 .get_size = ipgre_get_size, 1605 .fill_info = ipgre_fill_info, 1606 .get_link_net = ip_tunnel_get_link_net, 1607 }; 1608 1609 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = { 1610 .kind = "gretap", 1611 .maxtype = IFLA_GRE_MAX, 1612 .policy = ipgre_policy, 1613 .priv_size = sizeof(struct ip_tunnel), 1614 .setup = ipgre_tap_setup, 1615 .validate = ipgre_tap_validate, 1616 .newlink = ipgre_newlink, 1617 .changelink = ipgre_changelink, 1618 .dellink = ip_tunnel_dellink, 1619 .get_size = ipgre_get_size, 1620 .fill_info = ipgre_fill_info, 1621 .get_link_net = ip_tunnel_get_link_net, 1622 }; 1623 1624 static struct rtnl_link_ops erspan_link_ops __read_mostly = { 1625 .kind = "erspan", 1626 .maxtype = IFLA_GRE_MAX, 1627 .policy = ipgre_policy, 1628 .priv_size = sizeof(struct ip_tunnel), 1629 .setup = erspan_setup, 1630 .validate = erspan_validate, 1631 .newlink = erspan_newlink, 1632 .changelink = erspan_changelink, 1633 .dellink = ip_tunnel_dellink, 1634 .get_size = ipgre_get_size, 1635 .fill_info = ipgre_fill_info, 1636 .get_link_net = ip_tunnel_get_link_net, 1637 }; 1638 1639 struct net_device *gretap_fb_dev_create(struct net *net, const char *name, 1640 u8 name_assign_type) 1641 { 1642 struct nlattr *tb[IFLA_MAX + 1]; 1643 struct net_device *dev; 1644 LIST_HEAD(list_kill); 1645 struct ip_tunnel *t; 1646 int err; 1647 1648 memset(&tb, 0, sizeof(tb)); 1649 1650 dev = rtnl_create_link(net, name, name_assign_type, 1651 &ipgre_tap_ops, tb, NULL); 1652 if (IS_ERR(dev)) 1653 return dev; 1654 1655 /* Configure flow based GRE device. */ 1656 t = netdev_priv(dev); 1657 t->collect_md = true; 1658 1659 err = ipgre_newlink(net, dev, tb, NULL, NULL); 1660 if (err < 0) { 1661 free_netdev(dev); 1662 return ERR_PTR(err); 1663 } 1664 1665 /* openvswitch users expect packet sizes to be unrestricted, 1666 * so set the largest MTU we can. 1667 */ 1668 err = __ip_tunnel_change_mtu(dev, IP_MAX_MTU, false); 1669 if (err) 1670 goto out; 1671 1672 err = rtnl_configure_link(dev, NULL); 1673 if (err < 0) 1674 goto out; 1675 1676 return dev; 1677 out: 1678 ip_tunnel_dellink(dev, &list_kill); 1679 unregister_netdevice_many(&list_kill); 1680 return ERR_PTR(err); 1681 } 1682 EXPORT_SYMBOL_GPL(gretap_fb_dev_create); 1683 1684 static int __net_init ipgre_tap_init_net(struct net *net) 1685 { 1686 return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, "gretap0"); 1687 } 1688 1689 static void __net_exit ipgre_tap_exit_batch_net(struct list_head *list_net) 1690 { 1691 ip_tunnel_delete_nets(list_net, gre_tap_net_id, &ipgre_tap_ops); 1692 } 1693 1694 static struct pernet_operations ipgre_tap_net_ops = { 1695 .init = ipgre_tap_init_net, 1696 .exit_batch = ipgre_tap_exit_batch_net, 1697 .id = &gre_tap_net_id, 1698 .size = sizeof(struct ip_tunnel_net), 1699 }; 1700 1701 static int __net_init erspan_init_net(struct net *net) 1702 { 1703 return ip_tunnel_init_net(net, erspan_net_id, 1704 &erspan_link_ops, "erspan0"); 1705 } 1706 1707 static void __net_exit erspan_exit_batch_net(struct list_head *net_list) 1708 { 1709 ip_tunnel_delete_nets(net_list, erspan_net_id, &erspan_link_ops); 1710 } 1711 1712 static struct pernet_operations erspan_net_ops = { 1713 .init = erspan_init_net, 1714 .exit_batch = erspan_exit_batch_net, 1715 .id = &erspan_net_id, 1716 .size = sizeof(struct ip_tunnel_net), 1717 }; 1718 1719 static int __init ipgre_init(void) 1720 { 1721 int err; 1722 1723 pr_info("GRE over IPv4 tunneling driver\n"); 1724 1725 err = register_pernet_device(&ipgre_net_ops); 1726 if (err < 0) 1727 return err; 1728 1729 err = register_pernet_device(&ipgre_tap_net_ops); 1730 if (err < 0) 1731 goto pnet_tap_failed; 1732 1733 err = register_pernet_device(&erspan_net_ops); 1734 if (err < 0) 1735 goto pnet_erspan_failed; 1736 1737 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO); 1738 if (err < 0) { 1739 pr_info("%s: can't add protocol\n", __func__); 1740 goto add_proto_failed; 1741 } 1742 1743 err = rtnl_link_register(&ipgre_link_ops); 1744 if (err < 0) 1745 goto rtnl_link_failed; 1746 1747 err = rtnl_link_register(&ipgre_tap_ops); 1748 if (err < 0) 1749 goto tap_ops_failed; 1750 1751 err = rtnl_link_register(&erspan_link_ops); 1752 if (err < 0) 1753 goto erspan_link_failed; 1754 1755 return 0; 1756 1757 erspan_link_failed: 1758 rtnl_link_unregister(&ipgre_tap_ops); 1759 tap_ops_failed: 1760 rtnl_link_unregister(&ipgre_link_ops); 1761 rtnl_link_failed: 1762 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); 1763 add_proto_failed: 1764 unregister_pernet_device(&erspan_net_ops); 1765 pnet_erspan_failed: 1766 unregister_pernet_device(&ipgre_tap_net_ops); 1767 pnet_tap_failed: 1768 unregister_pernet_device(&ipgre_net_ops); 1769 return err; 1770 } 1771 1772 static void __exit ipgre_fini(void) 1773 { 1774 rtnl_link_unregister(&ipgre_tap_ops); 1775 rtnl_link_unregister(&ipgre_link_ops); 1776 rtnl_link_unregister(&erspan_link_ops); 1777 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); 1778 unregister_pernet_device(&ipgre_tap_net_ops); 1779 unregister_pernet_device(&ipgre_net_ops); 1780 unregister_pernet_device(&erspan_net_ops); 1781 } 1782 1783 module_init(ipgre_init); 1784 module_exit(ipgre_fini); 1785 MODULE_LICENSE("GPL"); 1786 MODULE_ALIAS_RTNL_LINK("gre"); 1787 MODULE_ALIAS_RTNL_LINK("gretap"); 1788 MODULE_ALIAS_RTNL_LINK("erspan"); 1789 MODULE_ALIAS_NETDEV("gre0"); 1790 MODULE_ALIAS_NETDEV("gretap0"); 1791 MODULE_ALIAS_NETDEV("erspan0"); 1792