1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Linux NET3: GRE over IP protocol decoder. 4 * 5 * Authors: Alexey Kuznetsov (kuznet@ms2.inr.ac.ru) 6 */ 7 8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 9 10 #include <linux/capability.h> 11 #include <linux/module.h> 12 #include <linux/types.h> 13 #include <linux/kernel.h> 14 #include <linux/slab.h> 15 #include <linux/uaccess.h> 16 #include <linux/skbuff.h> 17 #include <linux/netdevice.h> 18 #include <linux/in.h> 19 #include <linux/tcp.h> 20 #include <linux/udp.h> 21 #include <linux/if_arp.h> 22 #include <linux/if_vlan.h> 23 #include <linux/init.h> 24 #include <linux/in6.h> 25 #include <linux/inetdevice.h> 26 #include <linux/igmp.h> 27 #include <linux/netfilter_ipv4.h> 28 #include <linux/etherdevice.h> 29 #include <linux/if_ether.h> 30 31 #include <net/sock.h> 32 #include <net/ip.h> 33 #include <net/icmp.h> 34 #include <net/protocol.h> 35 #include <net/ip_tunnels.h> 36 #include <net/arp.h> 37 #include <net/checksum.h> 38 #include <net/dsfield.h> 39 #include <net/inet_ecn.h> 40 #include <net/xfrm.h> 41 #include <net/net_namespace.h> 42 #include <net/netns/generic.h> 43 #include <net/rtnetlink.h> 44 #include <net/gre.h> 45 #include <net/dst_metadata.h> 46 #include <net/erspan.h> 47 48 /* 49 Problems & solutions 50 -------------------- 51 52 1. The most important issue is detecting local dead loops. 53 They would cause complete host lockup in transmit, which 54 would be "resolved" by stack overflow or, if queueing is enabled, 55 with infinite looping in net_bh. 56 57 We cannot track such dead loops during route installation, 58 it is infeasible task. The most general solutions would be 59 to keep skb->encapsulation counter (sort of local ttl), 60 and silently drop packet when it expires. It is a good 61 solution, but it supposes maintaining new variable in ALL 62 skb, even if no tunneling is used. 63 64 Current solution: xmit_recursion breaks dead loops. This is a percpu 65 counter, since when we enter the first ndo_xmit(), cpu migration is 66 forbidden. We force an exit if this counter reaches RECURSION_LIMIT 67 68 2. Networking dead loops would not kill routers, but would really 69 kill network. IP hop limit plays role of "t->recursion" in this case, 70 if we copy it from packet being encapsulated to upper header. 71 It is very good solution, but it introduces two problems: 72 73 - Routing protocols, using packets with ttl=1 (OSPF, RIP2), 74 do not work over tunnels. 75 - traceroute does not work. I planned to relay ICMP from tunnel, 76 so that this problem would be solved and traceroute output 77 would even more informative. This idea appeared to be wrong: 78 only Linux complies to rfc1812 now (yes, guys, Linux is the only 79 true router now :-)), all routers (at least, in neighbourhood of mine) 80 return only 8 bytes of payload. It is the end. 81 82 Hence, if we want that OSPF worked or traceroute said something reasonable, 83 we should search for another solution. 84 85 One of them is to parse packet trying to detect inner encapsulation 86 made by our node. It is difficult or even impossible, especially, 87 taking into account fragmentation. TO be short, ttl is not solution at all. 88 89 Current solution: The solution was UNEXPECTEDLY SIMPLE. 90 We force DF flag on tunnels with preconfigured hop limit, 91 that is ALL. :-) Well, it does not remove the problem completely, 92 but exponential growth of network traffic is changed to linear 93 (branches, that exceed pmtu are pruned) and tunnel mtu 94 rapidly degrades to value <68, where looping stops. 95 Yes, it is not good if there exists a router in the loop, 96 which does not force DF, even when encapsulating packets have DF set. 97 But it is not our problem! Nobody could accuse us, we made 98 all that we could make. Even if it is your gated who injected 99 fatal route to network, even if it were you who configured 100 fatal static route: you are innocent. :-) 101 102 Alexey Kuznetsov. 103 */ 104 105 static bool log_ecn_error = true; 106 module_param(log_ecn_error, bool, 0644); 107 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN"); 108 109 static struct rtnl_link_ops ipgre_link_ops __read_mostly; 110 static int ipgre_tunnel_init(struct net_device *dev); 111 static void erspan_build_header(struct sk_buff *skb, 112 u32 id, u32 index, 113 bool truncate, bool is_ipv4); 114 115 static unsigned int ipgre_net_id __read_mostly; 116 static unsigned int gre_tap_net_id __read_mostly; 117 static unsigned int erspan_net_id __read_mostly; 118 119 static int ipgre_err(struct sk_buff *skb, u32 info, 120 const struct tnl_ptk_info *tpi) 121 { 122 123 /* All the routers (except for Linux) return only 124 8 bytes of packet payload. It means, that precise relaying of 125 ICMP in the real Internet is absolutely infeasible. 126 127 Moreover, Cisco "wise men" put GRE key to the third word 128 in GRE header. It makes impossible maintaining even soft 129 state for keyed GRE tunnels with enabled checksum. Tell 130 them "thank you". 131 132 Well, I wonder, rfc1812 was written by Cisco employee, 133 what the hell these idiots break standards established 134 by themselves??? 135 */ 136 struct net *net = dev_net(skb->dev); 137 struct ip_tunnel_net *itn; 138 const struct iphdr *iph; 139 const int type = icmp_hdr(skb)->type; 140 const int code = icmp_hdr(skb)->code; 141 unsigned int data_len = 0; 142 struct ip_tunnel *t; 143 144 if (tpi->proto == htons(ETH_P_TEB)) 145 itn = net_generic(net, gre_tap_net_id); 146 else if (tpi->proto == htons(ETH_P_ERSPAN) || 147 tpi->proto == htons(ETH_P_ERSPAN2)) 148 itn = net_generic(net, erspan_net_id); 149 else 150 itn = net_generic(net, ipgre_net_id); 151 152 iph = (const struct iphdr *)(icmp_hdr(skb) + 1); 153 t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags, 154 iph->daddr, iph->saddr, tpi->key); 155 156 if (!t) 157 return -ENOENT; 158 159 switch (type) { 160 default: 161 case ICMP_PARAMETERPROB: 162 return 0; 163 164 case ICMP_DEST_UNREACH: 165 switch (code) { 166 case ICMP_SR_FAILED: 167 case ICMP_PORT_UNREACH: 168 /* Impossible event. */ 169 return 0; 170 default: 171 /* All others are translated to HOST_UNREACH. 172 rfc2003 contains "deep thoughts" about NET_UNREACH, 173 I believe they are just ether pollution. --ANK 174 */ 175 break; 176 } 177 break; 178 179 case ICMP_TIME_EXCEEDED: 180 if (code != ICMP_EXC_TTL) 181 return 0; 182 data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */ 183 break; 184 185 case ICMP_REDIRECT: 186 break; 187 } 188 189 #if IS_ENABLED(CONFIG_IPV6) 190 if (tpi->proto == htons(ETH_P_IPV6) && 191 !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4 + tpi->hdr_len, 192 type, data_len)) 193 return 0; 194 #endif 195 196 if (t->parms.iph.daddr == 0 || 197 ipv4_is_multicast(t->parms.iph.daddr)) 198 return 0; 199 200 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 201 return 0; 202 203 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) 204 t->err_count++; 205 else 206 t->err_count = 1; 207 t->err_time = jiffies; 208 209 return 0; 210 } 211 212 static void gre_err(struct sk_buff *skb, u32 info) 213 { 214 /* All the routers (except for Linux) return only 215 * 8 bytes of packet payload. It means, that precise relaying of 216 * ICMP in the real Internet is absolutely infeasible. 217 * 218 * Moreover, Cisco "wise men" put GRE key to the third word 219 * in GRE header. It makes impossible maintaining even soft 220 * state for keyed 221 * GRE tunnels with enabled checksum. Tell them "thank you". 222 * 223 * Well, I wonder, rfc1812 was written by Cisco employee, 224 * what the hell these idiots break standards established 225 * by themselves??? 226 */ 227 228 const struct iphdr *iph = (struct iphdr *)skb->data; 229 const int type = icmp_hdr(skb)->type; 230 const int code = icmp_hdr(skb)->code; 231 struct tnl_ptk_info tpi; 232 233 if (gre_parse_header(skb, &tpi, NULL, htons(ETH_P_IP), 234 iph->ihl * 4) < 0) 235 return; 236 237 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { 238 ipv4_update_pmtu(skb, dev_net(skb->dev), info, 239 skb->dev->ifindex, IPPROTO_GRE); 240 return; 241 } 242 if (type == ICMP_REDIRECT) { 243 ipv4_redirect(skb, dev_net(skb->dev), skb->dev->ifindex, 244 IPPROTO_GRE); 245 return; 246 } 247 248 ipgre_err(skb, info, &tpi); 249 } 250 251 static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi, 252 int gre_hdr_len) 253 { 254 struct net *net = dev_net(skb->dev); 255 struct metadata_dst *tun_dst = NULL; 256 struct erspan_base_hdr *ershdr; 257 struct ip_tunnel_net *itn; 258 struct ip_tunnel *tunnel; 259 const struct iphdr *iph; 260 struct erspan_md2 *md2; 261 int ver; 262 int len; 263 264 itn = net_generic(net, erspan_net_id); 265 266 iph = ip_hdr(skb); 267 ershdr = (struct erspan_base_hdr *)(skb->data + gre_hdr_len); 268 ver = ershdr->ver; 269 270 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, 271 tpi->flags | TUNNEL_KEY, 272 iph->saddr, iph->daddr, tpi->key); 273 274 if (tunnel) { 275 len = gre_hdr_len + erspan_hdr_len(ver); 276 if (unlikely(!pskb_may_pull(skb, len))) 277 return PACKET_REJECT; 278 279 if (__iptunnel_pull_header(skb, 280 len, 281 htons(ETH_P_TEB), 282 false, false) < 0) 283 goto drop; 284 285 if (tunnel->collect_md) { 286 struct erspan_metadata *pkt_md, *md; 287 struct ip_tunnel_info *info; 288 unsigned char *gh; 289 __be64 tun_id; 290 __be16 flags; 291 292 tpi->flags |= TUNNEL_KEY; 293 flags = tpi->flags; 294 tun_id = key32_to_tunnel_id(tpi->key); 295 296 tun_dst = ip_tun_rx_dst(skb, flags, 297 tun_id, sizeof(*md)); 298 if (!tun_dst) 299 return PACKET_REJECT; 300 301 /* skb can be uncloned in __iptunnel_pull_header, so 302 * old pkt_md is no longer valid and we need to reset 303 * it 304 */ 305 gh = skb_network_header(skb) + 306 skb_network_header_len(skb); 307 pkt_md = (struct erspan_metadata *)(gh + gre_hdr_len + 308 sizeof(*ershdr)); 309 md = ip_tunnel_info_opts(&tun_dst->u.tun_info); 310 md->version = ver; 311 md2 = &md->u.md2; 312 memcpy(md2, pkt_md, ver == 1 ? ERSPAN_V1_MDSIZE : 313 ERSPAN_V2_MDSIZE); 314 315 info = &tun_dst->u.tun_info; 316 info->key.tun_flags |= TUNNEL_ERSPAN_OPT; 317 info->options_len = sizeof(*md); 318 } 319 320 skb_reset_mac_header(skb); 321 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error); 322 return PACKET_RCVD; 323 } 324 return PACKET_REJECT; 325 326 drop: 327 kfree_skb(skb); 328 return PACKET_RCVD; 329 } 330 331 static int __ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi, 332 struct ip_tunnel_net *itn, int hdr_len, bool raw_proto) 333 { 334 struct metadata_dst *tun_dst = NULL; 335 const struct iphdr *iph; 336 struct ip_tunnel *tunnel; 337 338 iph = ip_hdr(skb); 339 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags, 340 iph->saddr, iph->daddr, tpi->key); 341 342 if (tunnel) { 343 const struct iphdr *tnl_params; 344 345 if (__iptunnel_pull_header(skb, hdr_len, tpi->proto, 346 raw_proto, false) < 0) 347 goto drop; 348 349 if (tunnel->dev->type != ARPHRD_NONE) 350 skb_pop_mac_header(skb); 351 else 352 skb_reset_mac_header(skb); 353 354 tnl_params = &tunnel->parms.iph; 355 if (tunnel->collect_md || tnl_params->daddr == 0) { 356 __be16 flags; 357 __be64 tun_id; 358 359 flags = tpi->flags & (TUNNEL_CSUM | TUNNEL_KEY); 360 tun_id = key32_to_tunnel_id(tpi->key); 361 tun_dst = ip_tun_rx_dst(skb, flags, tun_id, 0); 362 if (!tun_dst) 363 return PACKET_REJECT; 364 } 365 366 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error); 367 return PACKET_RCVD; 368 } 369 return PACKET_NEXT; 370 371 drop: 372 kfree_skb(skb); 373 return PACKET_RCVD; 374 } 375 376 static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi, 377 int hdr_len) 378 { 379 struct net *net = dev_net(skb->dev); 380 struct ip_tunnel_net *itn; 381 int res; 382 383 if (tpi->proto == htons(ETH_P_TEB)) 384 itn = net_generic(net, gre_tap_net_id); 385 else 386 itn = net_generic(net, ipgre_net_id); 387 388 res = __ipgre_rcv(skb, tpi, itn, hdr_len, false); 389 if (res == PACKET_NEXT && tpi->proto == htons(ETH_P_TEB)) { 390 /* ipgre tunnels in collect metadata mode should receive 391 * also ETH_P_TEB traffic. 392 */ 393 itn = net_generic(net, ipgre_net_id); 394 res = __ipgre_rcv(skb, tpi, itn, hdr_len, true); 395 } 396 return res; 397 } 398 399 static int gre_rcv(struct sk_buff *skb) 400 { 401 struct tnl_ptk_info tpi; 402 bool csum_err = false; 403 int hdr_len; 404 405 #ifdef CONFIG_NET_IPGRE_BROADCAST 406 if (ipv4_is_multicast(ip_hdr(skb)->daddr)) { 407 /* Looped back packet, drop it! */ 408 if (rt_is_output_route(skb_rtable(skb))) 409 goto drop; 410 } 411 #endif 412 413 hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IP), 0); 414 if (hdr_len < 0) 415 goto drop; 416 417 if (unlikely(tpi.proto == htons(ETH_P_ERSPAN) || 418 tpi.proto == htons(ETH_P_ERSPAN2))) { 419 if (erspan_rcv(skb, &tpi, hdr_len) == PACKET_RCVD) 420 return 0; 421 goto out; 422 } 423 424 if (ipgre_rcv(skb, &tpi, hdr_len) == PACKET_RCVD) 425 return 0; 426 427 out: 428 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 429 drop: 430 kfree_skb(skb); 431 return 0; 432 } 433 434 static void __gre_xmit(struct sk_buff *skb, struct net_device *dev, 435 const struct iphdr *tnl_params, 436 __be16 proto) 437 { 438 struct ip_tunnel *tunnel = netdev_priv(dev); 439 440 if (tunnel->parms.o_flags & TUNNEL_SEQ) 441 tunnel->o_seqno++; 442 443 /* Push GRE header. */ 444 gre_build_header(skb, tunnel->tun_hlen, 445 tunnel->parms.o_flags, proto, tunnel->parms.o_key, 446 htonl(tunnel->o_seqno)); 447 448 ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol); 449 } 450 451 static int gre_handle_offloads(struct sk_buff *skb, bool csum) 452 { 453 return iptunnel_handle_offloads(skb, csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE); 454 } 455 456 static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev, 457 __be16 proto) 458 { 459 struct ip_tunnel *tunnel = netdev_priv(dev); 460 struct ip_tunnel_info *tun_info; 461 const struct ip_tunnel_key *key; 462 int tunnel_hlen; 463 __be16 flags; 464 465 tun_info = skb_tunnel_info(skb); 466 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) || 467 ip_tunnel_info_af(tun_info) != AF_INET)) 468 goto err_free_skb; 469 470 key = &tun_info->key; 471 tunnel_hlen = gre_calc_hlen(key->tun_flags); 472 473 if (skb_cow_head(skb, dev->needed_headroom)) 474 goto err_free_skb; 475 476 /* Push Tunnel header. */ 477 if (gre_handle_offloads(skb, !!(tun_info->key.tun_flags & TUNNEL_CSUM))) 478 goto err_free_skb; 479 480 flags = tun_info->key.tun_flags & 481 (TUNNEL_CSUM | TUNNEL_KEY | TUNNEL_SEQ); 482 gre_build_header(skb, tunnel_hlen, flags, proto, 483 tunnel_id_to_key32(tun_info->key.tun_id), 484 (flags & TUNNEL_SEQ) ? htonl(tunnel->o_seqno++) : 0); 485 486 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen); 487 488 return; 489 490 err_free_skb: 491 kfree_skb(skb); 492 dev->stats.tx_dropped++; 493 } 494 495 static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev) 496 { 497 struct ip_tunnel *tunnel = netdev_priv(dev); 498 struct ip_tunnel_info *tun_info; 499 const struct ip_tunnel_key *key; 500 struct erspan_metadata *md; 501 bool truncate = false; 502 __be16 proto; 503 int tunnel_hlen; 504 int version; 505 int nhoff; 506 int thoff; 507 508 tun_info = skb_tunnel_info(skb); 509 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) || 510 ip_tunnel_info_af(tun_info) != AF_INET)) 511 goto err_free_skb; 512 513 key = &tun_info->key; 514 if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT)) 515 goto err_free_skb; 516 if (tun_info->options_len < sizeof(*md)) 517 goto err_free_skb; 518 md = ip_tunnel_info_opts(tun_info); 519 520 /* ERSPAN has fixed 8 byte GRE header */ 521 version = md->version; 522 tunnel_hlen = 8 + erspan_hdr_len(version); 523 524 if (skb_cow_head(skb, dev->needed_headroom)) 525 goto err_free_skb; 526 527 if (gre_handle_offloads(skb, false)) 528 goto err_free_skb; 529 530 if (skb->len > dev->mtu + dev->hard_header_len) { 531 pskb_trim(skb, dev->mtu + dev->hard_header_len); 532 truncate = true; 533 } 534 535 nhoff = skb_network_header(skb) - skb_mac_header(skb); 536 if (skb->protocol == htons(ETH_P_IP) && 537 (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff)) 538 truncate = true; 539 540 thoff = skb_transport_header(skb) - skb_mac_header(skb); 541 if (skb->protocol == htons(ETH_P_IPV6) && 542 (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff)) 543 truncate = true; 544 545 if (version == 1) { 546 erspan_build_header(skb, ntohl(tunnel_id_to_key32(key->tun_id)), 547 ntohl(md->u.index), truncate, true); 548 proto = htons(ETH_P_ERSPAN); 549 } else if (version == 2) { 550 erspan_build_header_v2(skb, 551 ntohl(tunnel_id_to_key32(key->tun_id)), 552 md->u.md2.dir, 553 get_hwid(&md->u.md2), 554 truncate, true); 555 proto = htons(ETH_P_ERSPAN2); 556 } else { 557 goto err_free_skb; 558 } 559 560 gre_build_header(skb, 8, TUNNEL_SEQ, 561 proto, 0, htonl(tunnel->o_seqno++)); 562 563 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen); 564 565 return; 566 567 err_free_skb: 568 kfree_skb(skb); 569 dev->stats.tx_dropped++; 570 } 571 572 static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb) 573 { 574 struct ip_tunnel_info *info = skb_tunnel_info(skb); 575 const struct ip_tunnel_key *key; 576 struct rtable *rt; 577 struct flowi4 fl4; 578 579 if (ip_tunnel_info_af(info) != AF_INET) 580 return -EINVAL; 581 582 key = &info->key; 583 ip_tunnel_init_flow(&fl4, IPPROTO_GRE, key->u.ipv4.dst, key->u.ipv4.src, 584 tunnel_id_to_key32(key->tun_id), key->tos, 0, 585 skb->mark, skb_get_hash(skb)); 586 rt = ip_route_output_key(dev_net(dev), &fl4); 587 if (IS_ERR(rt)) 588 return PTR_ERR(rt); 589 590 ip_rt_put(rt); 591 info->key.u.ipv4.src = fl4.saddr; 592 return 0; 593 } 594 595 static netdev_tx_t ipgre_xmit(struct sk_buff *skb, 596 struct net_device *dev) 597 { 598 struct ip_tunnel *tunnel = netdev_priv(dev); 599 const struct iphdr *tnl_params; 600 601 if (!pskb_inet_may_pull(skb)) 602 goto free_skb; 603 604 if (tunnel->collect_md) { 605 gre_fb_xmit(skb, dev, skb->protocol); 606 return NETDEV_TX_OK; 607 } 608 609 if (dev->header_ops) { 610 /* Need space for new headers */ 611 if (skb_cow_head(skb, dev->needed_headroom - 612 (tunnel->hlen + sizeof(struct iphdr)))) 613 goto free_skb; 614 615 tnl_params = (const struct iphdr *)skb->data; 616 617 /* Pull skb since ip_tunnel_xmit() needs skb->data pointing 618 * to gre header. 619 */ 620 skb_pull(skb, tunnel->hlen + sizeof(struct iphdr)); 621 skb_reset_mac_header(skb); 622 } else { 623 if (skb_cow_head(skb, dev->needed_headroom)) 624 goto free_skb; 625 626 tnl_params = &tunnel->parms.iph; 627 } 628 629 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM))) 630 goto free_skb; 631 632 __gre_xmit(skb, dev, tnl_params, skb->protocol); 633 return NETDEV_TX_OK; 634 635 free_skb: 636 kfree_skb(skb); 637 dev->stats.tx_dropped++; 638 return NETDEV_TX_OK; 639 } 640 641 static netdev_tx_t erspan_xmit(struct sk_buff *skb, 642 struct net_device *dev) 643 { 644 struct ip_tunnel *tunnel = netdev_priv(dev); 645 bool truncate = false; 646 __be16 proto; 647 648 if (!pskb_inet_may_pull(skb)) 649 goto free_skb; 650 651 if (tunnel->collect_md) { 652 erspan_fb_xmit(skb, dev); 653 return NETDEV_TX_OK; 654 } 655 656 if (gre_handle_offloads(skb, false)) 657 goto free_skb; 658 659 if (skb_cow_head(skb, dev->needed_headroom)) 660 goto free_skb; 661 662 if (skb->len > dev->mtu + dev->hard_header_len) { 663 pskb_trim(skb, dev->mtu + dev->hard_header_len); 664 truncate = true; 665 } 666 667 /* Push ERSPAN header */ 668 if (tunnel->erspan_ver == 1) { 669 erspan_build_header(skb, ntohl(tunnel->parms.o_key), 670 tunnel->index, 671 truncate, true); 672 proto = htons(ETH_P_ERSPAN); 673 } else if (tunnel->erspan_ver == 2) { 674 erspan_build_header_v2(skb, ntohl(tunnel->parms.o_key), 675 tunnel->dir, tunnel->hwid, 676 truncate, true); 677 proto = htons(ETH_P_ERSPAN2); 678 } else { 679 goto free_skb; 680 } 681 682 tunnel->parms.o_flags &= ~TUNNEL_KEY; 683 __gre_xmit(skb, dev, &tunnel->parms.iph, proto); 684 return NETDEV_TX_OK; 685 686 free_skb: 687 kfree_skb(skb); 688 dev->stats.tx_dropped++; 689 return NETDEV_TX_OK; 690 } 691 692 static netdev_tx_t gre_tap_xmit(struct sk_buff *skb, 693 struct net_device *dev) 694 { 695 struct ip_tunnel *tunnel = netdev_priv(dev); 696 697 if (!pskb_inet_may_pull(skb)) 698 goto free_skb; 699 700 if (tunnel->collect_md) { 701 gre_fb_xmit(skb, dev, htons(ETH_P_TEB)); 702 return NETDEV_TX_OK; 703 } 704 705 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM))) 706 goto free_skb; 707 708 if (skb_cow_head(skb, dev->needed_headroom)) 709 goto free_skb; 710 711 __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB)); 712 return NETDEV_TX_OK; 713 714 free_skb: 715 kfree_skb(skb); 716 dev->stats.tx_dropped++; 717 return NETDEV_TX_OK; 718 } 719 720 static void ipgre_link_update(struct net_device *dev, bool set_mtu) 721 { 722 struct ip_tunnel *tunnel = netdev_priv(dev); 723 int len; 724 725 len = tunnel->tun_hlen; 726 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags); 727 len = tunnel->tun_hlen - len; 728 tunnel->hlen = tunnel->hlen + len; 729 730 dev->needed_headroom = dev->needed_headroom + len; 731 if (set_mtu) 732 dev->mtu = max_t(int, dev->mtu - len, 68); 733 734 if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) { 735 if (!(tunnel->parms.o_flags & TUNNEL_CSUM) || 736 tunnel->encap.type == TUNNEL_ENCAP_NONE) { 737 dev->features |= NETIF_F_GSO_SOFTWARE; 738 dev->hw_features |= NETIF_F_GSO_SOFTWARE; 739 } else { 740 dev->features &= ~NETIF_F_GSO_SOFTWARE; 741 dev->hw_features &= ~NETIF_F_GSO_SOFTWARE; 742 } 743 dev->features |= NETIF_F_LLTX; 744 } else { 745 dev->hw_features &= ~NETIF_F_GSO_SOFTWARE; 746 dev->features &= ~(NETIF_F_LLTX | NETIF_F_GSO_SOFTWARE); 747 } 748 } 749 750 static int ipgre_tunnel_ioctl(struct net_device *dev, 751 struct ifreq *ifr, int cmd) 752 { 753 struct ip_tunnel_parm p; 754 int err; 755 756 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 757 return -EFAULT; 758 759 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) { 760 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE || 761 p.iph.ihl != 5 || (p.iph.frag_off & htons(~IP_DF)) || 762 ((p.i_flags | p.o_flags) & (GRE_VERSION | GRE_ROUTING))) 763 return -EINVAL; 764 } 765 766 p.i_flags = gre_flags_to_tnl_flags(p.i_flags); 767 p.o_flags = gre_flags_to_tnl_flags(p.o_flags); 768 769 err = ip_tunnel_ioctl(dev, &p, cmd); 770 if (err) 771 return err; 772 773 if (cmd == SIOCCHGTUNNEL) { 774 struct ip_tunnel *t = netdev_priv(dev); 775 776 t->parms.i_flags = p.i_flags; 777 t->parms.o_flags = p.o_flags; 778 779 if (strcmp(dev->rtnl_link_ops->kind, "erspan")) 780 ipgre_link_update(dev, true); 781 } 782 783 p.i_flags = gre_tnl_flags_to_gre_flags(p.i_flags); 784 p.o_flags = gre_tnl_flags_to_gre_flags(p.o_flags); 785 786 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 787 return -EFAULT; 788 789 return 0; 790 } 791 792 /* Nice toy. Unfortunately, useless in real life :-) 793 It allows to construct virtual multiprotocol broadcast "LAN" 794 over the Internet, provided multicast routing is tuned. 795 796 797 I have no idea was this bicycle invented before me, 798 so that I had to set ARPHRD_IPGRE to a random value. 799 I have an impression, that Cisco could make something similar, 800 but this feature is apparently missing in IOS<=11.2(8). 801 802 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks 803 with broadcast 224.66.66.66. If you have access to mbone, play with me :-) 804 805 ping -t 255 224.66.66.66 806 807 If nobody answers, mbone does not work. 808 809 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255 810 ip addr add 10.66.66.<somewhat>/24 dev Universe 811 ifconfig Universe up 812 ifconfig Universe add fe80::<Your_real_addr>/10 813 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96 814 ftp 10.66.66.66 815 ... 816 ftp fec0:6666:6666::193.233.7.65 817 ... 818 */ 819 static int ipgre_header(struct sk_buff *skb, struct net_device *dev, 820 unsigned short type, 821 const void *daddr, const void *saddr, unsigned int len) 822 { 823 struct ip_tunnel *t = netdev_priv(dev); 824 struct iphdr *iph; 825 struct gre_base_hdr *greh; 826 827 iph = skb_push(skb, t->hlen + sizeof(*iph)); 828 greh = (struct gre_base_hdr *)(iph+1); 829 greh->flags = gre_tnl_flags_to_gre_flags(t->parms.o_flags); 830 greh->protocol = htons(type); 831 832 memcpy(iph, &t->parms.iph, sizeof(struct iphdr)); 833 834 /* Set the source hardware address. */ 835 if (saddr) 836 memcpy(&iph->saddr, saddr, 4); 837 if (daddr) 838 memcpy(&iph->daddr, daddr, 4); 839 if (iph->daddr) 840 return t->hlen + sizeof(*iph); 841 842 return -(t->hlen + sizeof(*iph)); 843 } 844 845 static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr) 846 { 847 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb); 848 memcpy(haddr, &iph->saddr, 4); 849 return 4; 850 } 851 852 static const struct header_ops ipgre_header_ops = { 853 .create = ipgre_header, 854 .parse = ipgre_header_parse, 855 }; 856 857 #ifdef CONFIG_NET_IPGRE_BROADCAST 858 static int ipgre_open(struct net_device *dev) 859 { 860 struct ip_tunnel *t = netdev_priv(dev); 861 862 if (ipv4_is_multicast(t->parms.iph.daddr)) { 863 struct flowi4 fl4; 864 struct rtable *rt; 865 866 rt = ip_route_output_gre(t->net, &fl4, 867 t->parms.iph.daddr, 868 t->parms.iph.saddr, 869 t->parms.o_key, 870 RT_TOS(t->parms.iph.tos), 871 t->parms.link); 872 if (IS_ERR(rt)) 873 return -EADDRNOTAVAIL; 874 dev = rt->dst.dev; 875 ip_rt_put(rt); 876 if (!__in_dev_get_rtnl(dev)) 877 return -EADDRNOTAVAIL; 878 t->mlink = dev->ifindex; 879 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr); 880 } 881 return 0; 882 } 883 884 static int ipgre_close(struct net_device *dev) 885 { 886 struct ip_tunnel *t = netdev_priv(dev); 887 888 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) { 889 struct in_device *in_dev; 890 in_dev = inetdev_by_index(t->net, t->mlink); 891 if (in_dev) 892 ip_mc_dec_group(in_dev, t->parms.iph.daddr); 893 } 894 return 0; 895 } 896 #endif 897 898 static const struct net_device_ops ipgre_netdev_ops = { 899 .ndo_init = ipgre_tunnel_init, 900 .ndo_uninit = ip_tunnel_uninit, 901 #ifdef CONFIG_NET_IPGRE_BROADCAST 902 .ndo_open = ipgre_open, 903 .ndo_stop = ipgre_close, 904 #endif 905 .ndo_start_xmit = ipgre_xmit, 906 .ndo_do_ioctl = ipgre_tunnel_ioctl, 907 .ndo_change_mtu = ip_tunnel_change_mtu, 908 .ndo_get_stats64 = ip_tunnel_get_stats64, 909 .ndo_get_iflink = ip_tunnel_get_iflink, 910 }; 911 912 #define GRE_FEATURES (NETIF_F_SG | \ 913 NETIF_F_FRAGLIST | \ 914 NETIF_F_HIGHDMA | \ 915 NETIF_F_HW_CSUM) 916 917 static void ipgre_tunnel_setup(struct net_device *dev) 918 { 919 dev->netdev_ops = &ipgre_netdev_ops; 920 dev->type = ARPHRD_IPGRE; 921 ip_tunnel_setup(dev, ipgre_net_id); 922 } 923 924 static void __gre_tunnel_init(struct net_device *dev) 925 { 926 struct ip_tunnel *tunnel; 927 928 tunnel = netdev_priv(dev); 929 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags); 930 tunnel->parms.iph.protocol = IPPROTO_GRE; 931 932 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen; 933 934 dev->features |= GRE_FEATURES; 935 dev->hw_features |= GRE_FEATURES; 936 937 if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) { 938 /* TCP offload with GRE SEQ is not supported, nor 939 * can we support 2 levels of outer headers requiring 940 * an update. 941 */ 942 if (!(tunnel->parms.o_flags & TUNNEL_CSUM) || 943 (tunnel->encap.type == TUNNEL_ENCAP_NONE)) { 944 dev->features |= NETIF_F_GSO_SOFTWARE; 945 dev->hw_features |= NETIF_F_GSO_SOFTWARE; 946 } 947 948 /* Can use a lockless transmit, unless we generate 949 * output sequences 950 */ 951 dev->features |= NETIF_F_LLTX; 952 } 953 } 954 955 static int ipgre_tunnel_init(struct net_device *dev) 956 { 957 struct ip_tunnel *tunnel = netdev_priv(dev); 958 struct iphdr *iph = &tunnel->parms.iph; 959 960 __gre_tunnel_init(dev); 961 962 memcpy(dev->dev_addr, &iph->saddr, 4); 963 memcpy(dev->broadcast, &iph->daddr, 4); 964 965 dev->flags = IFF_NOARP; 966 netif_keep_dst(dev); 967 dev->addr_len = 4; 968 969 if (iph->daddr && !tunnel->collect_md) { 970 #ifdef CONFIG_NET_IPGRE_BROADCAST 971 if (ipv4_is_multicast(iph->daddr)) { 972 if (!iph->saddr) 973 return -EINVAL; 974 dev->flags = IFF_BROADCAST; 975 dev->header_ops = &ipgre_header_ops; 976 } 977 #endif 978 } else if (!tunnel->collect_md) { 979 dev->header_ops = &ipgre_header_ops; 980 } 981 982 return ip_tunnel_init(dev); 983 } 984 985 static const struct gre_protocol ipgre_protocol = { 986 .handler = gre_rcv, 987 .err_handler = gre_err, 988 }; 989 990 static int __net_init ipgre_init_net(struct net *net) 991 { 992 return ip_tunnel_init_net(net, ipgre_net_id, &ipgre_link_ops, NULL); 993 } 994 995 static void __net_exit ipgre_exit_batch_net(struct list_head *list_net) 996 { 997 ip_tunnel_delete_nets(list_net, ipgre_net_id, &ipgre_link_ops); 998 } 999 1000 static struct pernet_operations ipgre_net_ops = { 1001 .init = ipgre_init_net, 1002 .exit_batch = ipgre_exit_batch_net, 1003 .id = &ipgre_net_id, 1004 .size = sizeof(struct ip_tunnel_net), 1005 }; 1006 1007 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[], 1008 struct netlink_ext_ack *extack) 1009 { 1010 __be16 flags; 1011 1012 if (!data) 1013 return 0; 1014 1015 flags = 0; 1016 if (data[IFLA_GRE_IFLAGS]) 1017 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); 1018 if (data[IFLA_GRE_OFLAGS]) 1019 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); 1020 if (flags & (GRE_VERSION|GRE_ROUTING)) 1021 return -EINVAL; 1022 1023 if (data[IFLA_GRE_COLLECT_METADATA] && 1024 data[IFLA_GRE_ENCAP_TYPE] && 1025 nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]) != TUNNEL_ENCAP_NONE) 1026 return -EINVAL; 1027 1028 return 0; 1029 } 1030 1031 static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[], 1032 struct netlink_ext_ack *extack) 1033 { 1034 __be32 daddr; 1035 1036 if (tb[IFLA_ADDRESS]) { 1037 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) 1038 return -EINVAL; 1039 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) 1040 return -EADDRNOTAVAIL; 1041 } 1042 1043 if (!data) 1044 goto out; 1045 1046 if (data[IFLA_GRE_REMOTE]) { 1047 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4); 1048 if (!daddr) 1049 return -EINVAL; 1050 } 1051 1052 out: 1053 return ipgre_tunnel_validate(tb, data, extack); 1054 } 1055 1056 static int erspan_validate(struct nlattr *tb[], struct nlattr *data[], 1057 struct netlink_ext_ack *extack) 1058 { 1059 __be16 flags = 0; 1060 int ret; 1061 1062 if (!data) 1063 return 0; 1064 1065 ret = ipgre_tap_validate(tb, data, extack); 1066 if (ret) 1067 return ret; 1068 1069 /* ERSPAN should only have GRE sequence and key flag */ 1070 if (data[IFLA_GRE_OFLAGS]) 1071 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); 1072 if (data[IFLA_GRE_IFLAGS]) 1073 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); 1074 if (!data[IFLA_GRE_COLLECT_METADATA] && 1075 flags != (GRE_SEQ | GRE_KEY)) 1076 return -EINVAL; 1077 1078 /* ERSPAN Session ID only has 10-bit. Since we reuse 1079 * 32-bit key field as ID, check it's range. 1080 */ 1081 if (data[IFLA_GRE_IKEY] && 1082 (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK)) 1083 return -EINVAL; 1084 1085 if (data[IFLA_GRE_OKEY] && 1086 (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK)) 1087 return -EINVAL; 1088 1089 return 0; 1090 } 1091 1092 static int ipgre_netlink_parms(struct net_device *dev, 1093 struct nlattr *data[], 1094 struct nlattr *tb[], 1095 struct ip_tunnel_parm *parms, 1096 __u32 *fwmark) 1097 { 1098 struct ip_tunnel *t = netdev_priv(dev); 1099 1100 memset(parms, 0, sizeof(*parms)); 1101 1102 parms->iph.protocol = IPPROTO_GRE; 1103 1104 if (!data) 1105 return 0; 1106 1107 if (data[IFLA_GRE_LINK]) 1108 parms->link = nla_get_u32(data[IFLA_GRE_LINK]); 1109 1110 if (data[IFLA_GRE_IFLAGS]) 1111 parms->i_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_IFLAGS])); 1112 1113 if (data[IFLA_GRE_OFLAGS]) 1114 parms->o_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_OFLAGS])); 1115 1116 if (data[IFLA_GRE_IKEY]) 1117 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]); 1118 1119 if (data[IFLA_GRE_OKEY]) 1120 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]); 1121 1122 if (data[IFLA_GRE_LOCAL]) 1123 parms->iph.saddr = nla_get_in_addr(data[IFLA_GRE_LOCAL]); 1124 1125 if (data[IFLA_GRE_REMOTE]) 1126 parms->iph.daddr = nla_get_in_addr(data[IFLA_GRE_REMOTE]); 1127 1128 if (data[IFLA_GRE_TTL]) 1129 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]); 1130 1131 if (data[IFLA_GRE_TOS]) 1132 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]); 1133 1134 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC])) { 1135 if (t->ignore_df) 1136 return -EINVAL; 1137 parms->iph.frag_off = htons(IP_DF); 1138 } 1139 1140 if (data[IFLA_GRE_COLLECT_METADATA]) { 1141 t->collect_md = true; 1142 if (dev->type == ARPHRD_IPGRE) 1143 dev->type = ARPHRD_NONE; 1144 } 1145 1146 if (data[IFLA_GRE_IGNORE_DF]) { 1147 if (nla_get_u8(data[IFLA_GRE_IGNORE_DF]) 1148 && (parms->iph.frag_off & htons(IP_DF))) 1149 return -EINVAL; 1150 t->ignore_df = !!nla_get_u8(data[IFLA_GRE_IGNORE_DF]); 1151 } 1152 1153 if (data[IFLA_GRE_FWMARK]) 1154 *fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]); 1155 1156 if (data[IFLA_GRE_ERSPAN_VER]) { 1157 t->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]); 1158 1159 if (t->erspan_ver != 1 && t->erspan_ver != 2) 1160 return -EINVAL; 1161 } 1162 1163 if (t->erspan_ver == 1) { 1164 if (data[IFLA_GRE_ERSPAN_INDEX]) { 1165 t->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]); 1166 if (t->index & ~INDEX_MASK) 1167 return -EINVAL; 1168 } 1169 } else if (t->erspan_ver == 2) { 1170 if (data[IFLA_GRE_ERSPAN_DIR]) { 1171 t->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]); 1172 if (t->dir & ~(DIR_MASK >> DIR_OFFSET)) 1173 return -EINVAL; 1174 } 1175 if (data[IFLA_GRE_ERSPAN_HWID]) { 1176 t->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]); 1177 if (t->hwid & ~(HWID_MASK >> HWID_OFFSET)) 1178 return -EINVAL; 1179 } 1180 } 1181 1182 return 0; 1183 } 1184 1185 /* This function returns true when ENCAP attributes are present in the nl msg */ 1186 static bool ipgre_netlink_encap_parms(struct nlattr *data[], 1187 struct ip_tunnel_encap *ipencap) 1188 { 1189 bool ret = false; 1190 1191 memset(ipencap, 0, sizeof(*ipencap)); 1192 1193 if (!data) 1194 return ret; 1195 1196 if (data[IFLA_GRE_ENCAP_TYPE]) { 1197 ret = true; 1198 ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]); 1199 } 1200 1201 if (data[IFLA_GRE_ENCAP_FLAGS]) { 1202 ret = true; 1203 ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]); 1204 } 1205 1206 if (data[IFLA_GRE_ENCAP_SPORT]) { 1207 ret = true; 1208 ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]); 1209 } 1210 1211 if (data[IFLA_GRE_ENCAP_DPORT]) { 1212 ret = true; 1213 ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]); 1214 } 1215 1216 return ret; 1217 } 1218 1219 static int gre_tap_init(struct net_device *dev) 1220 { 1221 __gre_tunnel_init(dev); 1222 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1223 netif_keep_dst(dev); 1224 1225 return ip_tunnel_init(dev); 1226 } 1227 1228 static const struct net_device_ops gre_tap_netdev_ops = { 1229 .ndo_init = gre_tap_init, 1230 .ndo_uninit = ip_tunnel_uninit, 1231 .ndo_start_xmit = gre_tap_xmit, 1232 .ndo_set_mac_address = eth_mac_addr, 1233 .ndo_validate_addr = eth_validate_addr, 1234 .ndo_change_mtu = ip_tunnel_change_mtu, 1235 .ndo_get_stats64 = ip_tunnel_get_stats64, 1236 .ndo_get_iflink = ip_tunnel_get_iflink, 1237 .ndo_fill_metadata_dst = gre_fill_metadata_dst, 1238 }; 1239 1240 static int erspan_tunnel_init(struct net_device *dev) 1241 { 1242 struct ip_tunnel *tunnel = netdev_priv(dev); 1243 1244 tunnel->tun_hlen = 8; 1245 tunnel->parms.iph.protocol = IPPROTO_GRE; 1246 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen + 1247 erspan_hdr_len(tunnel->erspan_ver); 1248 1249 dev->features |= GRE_FEATURES; 1250 dev->hw_features |= GRE_FEATURES; 1251 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1252 netif_keep_dst(dev); 1253 1254 return ip_tunnel_init(dev); 1255 } 1256 1257 static const struct net_device_ops erspan_netdev_ops = { 1258 .ndo_init = erspan_tunnel_init, 1259 .ndo_uninit = ip_tunnel_uninit, 1260 .ndo_start_xmit = erspan_xmit, 1261 .ndo_set_mac_address = eth_mac_addr, 1262 .ndo_validate_addr = eth_validate_addr, 1263 .ndo_change_mtu = ip_tunnel_change_mtu, 1264 .ndo_get_stats64 = ip_tunnel_get_stats64, 1265 .ndo_get_iflink = ip_tunnel_get_iflink, 1266 .ndo_fill_metadata_dst = gre_fill_metadata_dst, 1267 }; 1268 1269 static void ipgre_tap_setup(struct net_device *dev) 1270 { 1271 ether_setup(dev); 1272 dev->max_mtu = 0; 1273 dev->netdev_ops = &gre_tap_netdev_ops; 1274 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 1275 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1276 ip_tunnel_setup(dev, gre_tap_net_id); 1277 } 1278 1279 static int ipgre_newlink(struct net *src_net, struct net_device *dev, 1280 struct nlattr *tb[], struct nlattr *data[], 1281 struct netlink_ext_ack *extack) 1282 { 1283 struct ip_tunnel_parm p; 1284 struct ip_tunnel_encap ipencap; 1285 __u32 fwmark = 0; 1286 int err; 1287 1288 if (ipgre_netlink_encap_parms(data, &ipencap)) { 1289 struct ip_tunnel *t = netdev_priv(dev); 1290 err = ip_tunnel_encap_setup(t, &ipencap); 1291 1292 if (err < 0) 1293 return err; 1294 } 1295 1296 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark); 1297 if (err < 0) 1298 return err; 1299 return ip_tunnel_newlink(dev, tb, &p, fwmark); 1300 } 1301 1302 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[], 1303 struct nlattr *data[], 1304 struct netlink_ext_ack *extack) 1305 { 1306 struct ip_tunnel *t = netdev_priv(dev); 1307 struct ip_tunnel_encap ipencap; 1308 __u32 fwmark = t->fwmark; 1309 struct ip_tunnel_parm p; 1310 int err; 1311 1312 if (ipgre_netlink_encap_parms(data, &ipencap)) { 1313 err = ip_tunnel_encap_setup(t, &ipencap); 1314 1315 if (err < 0) 1316 return err; 1317 } 1318 1319 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark); 1320 if (err < 0) 1321 return err; 1322 1323 err = ip_tunnel_changelink(dev, tb, &p, fwmark); 1324 if (err < 0) 1325 return err; 1326 1327 t->parms.i_flags = p.i_flags; 1328 t->parms.o_flags = p.o_flags; 1329 1330 if (strcmp(dev->rtnl_link_ops->kind, "erspan")) 1331 ipgre_link_update(dev, !tb[IFLA_MTU]); 1332 1333 return 0; 1334 } 1335 1336 static size_t ipgre_get_size(const struct net_device *dev) 1337 { 1338 return 1339 /* IFLA_GRE_LINK */ 1340 nla_total_size(4) + 1341 /* IFLA_GRE_IFLAGS */ 1342 nla_total_size(2) + 1343 /* IFLA_GRE_OFLAGS */ 1344 nla_total_size(2) + 1345 /* IFLA_GRE_IKEY */ 1346 nla_total_size(4) + 1347 /* IFLA_GRE_OKEY */ 1348 nla_total_size(4) + 1349 /* IFLA_GRE_LOCAL */ 1350 nla_total_size(4) + 1351 /* IFLA_GRE_REMOTE */ 1352 nla_total_size(4) + 1353 /* IFLA_GRE_TTL */ 1354 nla_total_size(1) + 1355 /* IFLA_GRE_TOS */ 1356 nla_total_size(1) + 1357 /* IFLA_GRE_PMTUDISC */ 1358 nla_total_size(1) + 1359 /* IFLA_GRE_ENCAP_TYPE */ 1360 nla_total_size(2) + 1361 /* IFLA_GRE_ENCAP_FLAGS */ 1362 nla_total_size(2) + 1363 /* IFLA_GRE_ENCAP_SPORT */ 1364 nla_total_size(2) + 1365 /* IFLA_GRE_ENCAP_DPORT */ 1366 nla_total_size(2) + 1367 /* IFLA_GRE_COLLECT_METADATA */ 1368 nla_total_size(0) + 1369 /* IFLA_GRE_IGNORE_DF */ 1370 nla_total_size(1) + 1371 /* IFLA_GRE_FWMARK */ 1372 nla_total_size(4) + 1373 /* IFLA_GRE_ERSPAN_INDEX */ 1374 nla_total_size(4) + 1375 /* IFLA_GRE_ERSPAN_VER */ 1376 nla_total_size(1) + 1377 /* IFLA_GRE_ERSPAN_DIR */ 1378 nla_total_size(1) + 1379 /* IFLA_GRE_ERSPAN_HWID */ 1380 nla_total_size(2) + 1381 0; 1382 } 1383 1384 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev) 1385 { 1386 struct ip_tunnel *t = netdev_priv(dev); 1387 struct ip_tunnel_parm *p = &t->parms; 1388 __be16 o_flags = p->o_flags; 1389 1390 if (t->erspan_ver == 1 || t->erspan_ver == 2) { 1391 if (!t->collect_md) 1392 o_flags |= TUNNEL_KEY; 1393 1394 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, t->erspan_ver)) 1395 goto nla_put_failure; 1396 1397 if (t->erspan_ver == 1) { 1398 if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, t->index)) 1399 goto nla_put_failure; 1400 } else { 1401 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, t->dir)) 1402 goto nla_put_failure; 1403 if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, t->hwid)) 1404 goto nla_put_failure; 1405 } 1406 } 1407 1408 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) || 1409 nla_put_be16(skb, IFLA_GRE_IFLAGS, 1410 gre_tnl_flags_to_gre_flags(p->i_flags)) || 1411 nla_put_be16(skb, IFLA_GRE_OFLAGS, 1412 gre_tnl_flags_to_gre_flags(o_flags)) || 1413 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) || 1414 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) || 1415 nla_put_in_addr(skb, IFLA_GRE_LOCAL, p->iph.saddr) || 1416 nla_put_in_addr(skb, IFLA_GRE_REMOTE, p->iph.daddr) || 1417 nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) || 1418 nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) || 1419 nla_put_u8(skb, IFLA_GRE_PMTUDISC, 1420 !!(p->iph.frag_off & htons(IP_DF))) || 1421 nla_put_u32(skb, IFLA_GRE_FWMARK, t->fwmark)) 1422 goto nla_put_failure; 1423 1424 if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE, 1425 t->encap.type) || 1426 nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT, 1427 t->encap.sport) || 1428 nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT, 1429 t->encap.dport) || 1430 nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS, 1431 t->encap.flags)) 1432 goto nla_put_failure; 1433 1434 if (nla_put_u8(skb, IFLA_GRE_IGNORE_DF, t->ignore_df)) 1435 goto nla_put_failure; 1436 1437 if (t->collect_md) { 1438 if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA)) 1439 goto nla_put_failure; 1440 } 1441 1442 return 0; 1443 1444 nla_put_failure: 1445 return -EMSGSIZE; 1446 } 1447 1448 static void erspan_setup(struct net_device *dev) 1449 { 1450 struct ip_tunnel *t = netdev_priv(dev); 1451 1452 ether_setup(dev); 1453 dev->max_mtu = 0; 1454 dev->netdev_ops = &erspan_netdev_ops; 1455 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 1456 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1457 ip_tunnel_setup(dev, erspan_net_id); 1458 t->erspan_ver = 1; 1459 } 1460 1461 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = { 1462 [IFLA_GRE_LINK] = { .type = NLA_U32 }, 1463 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 }, 1464 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 }, 1465 [IFLA_GRE_IKEY] = { .type = NLA_U32 }, 1466 [IFLA_GRE_OKEY] = { .type = NLA_U32 }, 1467 [IFLA_GRE_LOCAL] = { .len = sizeof_field(struct iphdr, saddr) }, 1468 [IFLA_GRE_REMOTE] = { .len = sizeof_field(struct iphdr, daddr) }, 1469 [IFLA_GRE_TTL] = { .type = NLA_U8 }, 1470 [IFLA_GRE_TOS] = { .type = NLA_U8 }, 1471 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 }, 1472 [IFLA_GRE_ENCAP_TYPE] = { .type = NLA_U16 }, 1473 [IFLA_GRE_ENCAP_FLAGS] = { .type = NLA_U16 }, 1474 [IFLA_GRE_ENCAP_SPORT] = { .type = NLA_U16 }, 1475 [IFLA_GRE_ENCAP_DPORT] = { .type = NLA_U16 }, 1476 [IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG }, 1477 [IFLA_GRE_IGNORE_DF] = { .type = NLA_U8 }, 1478 [IFLA_GRE_FWMARK] = { .type = NLA_U32 }, 1479 [IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 }, 1480 [IFLA_GRE_ERSPAN_VER] = { .type = NLA_U8 }, 1481 [IFLA_GRE_ERSPAN_DIR] = { .type = NLA_U8 }, 1482 [IFLA_GRE_ERSPAN_HWID] = { .type = NLA_U16 }, 1483 }; 1484 1485 static struct rtnl_link_ops ipgre_link_ops __read_mostly = { 1486 .kind = "gre", 1487 .maxtype = IFLA_GRE_MAX, 1488 .policy = ipgre_policy, 1489 .priv_size = sizeof(struct ip_tunnel), 1490 .setup = ipgre_tunnel_setup, 1491 .validate = ipgre_tunnel_validate, 1492 .newlink = ipgre_newlink, 1493 .changelink = ipgre_changelink, 1494 .dellink = ip_tunnel_dellink, 1495 .get_size = ipgre_get_size, 1496 .fill_info = ipgre_fill_info, 1497 .get_link_net = ip_tunnel_get_link_net, 1498 }; 1499 1500 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = { 1501 .kind = "gretap", 1502 .maxtype = IFLA_GRE_MAX, 1503 .policy = ipgre_policy, 1504 .priv_size = sizeof(struct ip_tunnel), 1505 .setup = ipgre_tap_setup, 1506 .validate = ipgre_tap_validate, 1507 .newlink = ipgre_newlink, 1508 .changelink = ipgre_changelink, 1509 .dellink = ip_tunnel_dellink, 1510 .get_size = ipgre_get_size, 1511 .fill_info = ipgre_fill_info, 1512 .get_link_net = ip_tunnel_get_link_net, 1513 }; 1514 1515 static struct rtnl_link_ops erspan_link_ops __read_mostly = { 1516 .kind = "erspan", 1517 .maxtype = IFLA_GRE_MAX, 1518 .policy = ipgre_policy, 1519 .priv_size = sizeof(struct ip_tunnel), 1520 .setup = erspan_setup, 1521 .validate = erspan_validate, 1522 .newlink = ipgre_newlink, 1523 .changelink = ipgre_changelink, 1524 .dellink = ip_tunnel_dellink, 1525 .get_size = ipgre_get_size, 1526 .fill_info = ipgre_fill_info, 1527 .get_link_net = ip_tunnel_get_link_net, 1528 }; 1529 1530 struct net_device *gretap_fb_dev_create(struct net *net, const char *name, 1531 u8 name_assign_type) 1532 { 1533 struct nlattr *tb[IFLA_MAX + 1]; 1534 struct net_device *dev; 1535 LIST_HEAD(list_kill); 1536 struct ip_tunnel *t; 1537 int err; 1538 1539 memset(&tb, 0, sizeof(tb)); 1540 1541 dev = rtnl_create_link(net, name, name_assign_type, 1542 &ipgre_tap_ops, tb, NULL); 1543 if (IS_ERR(dev)) 1544 return dev; 1545 1546 /* Configure flow based GRE device. */ 1547 t = netdev_priv(dev); 1548 t->collect_md = true; 1549 1550 err = ipgre_newlink(net, dev, tb, NULL, NULL); 1551 if (err < 0) { 1552 free_netdev(dev); 1553 return ERR_PTR(err); 1554 } 1555 1556 /* openvswitch users expect packet sizes to be unrestricted, 1557 * so set the largest MTU we can. 1558 */ 1559 err = __ip_tunnel_change_mtu(dev, IP_MAX_MTU, false); 1560 if (err) 1561 goto out; 1562 1563 err = rtnl_configure_link(dev, NULL); 1564 if (err < 0) 1565 goto out; 1566 1567 return dev; 1568 out: 1569 ip_tunnel_dellink(dev, &list_kill); 1570 unregister_netdevice_many(&list_kill); 1571 return ERR_PTR(err); 1572 } 1573 EXPORT_SYMBOL_GPL(gretap_fb_dev_create); 1574 1575 static int __net_init ipgre_tap_init_net(struct net *net) 1576 { 1577 return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, "gretap0"); 1578 } 1579 1580 static void __net_exit ipgre_tap_exit_batch_net(struct list_head *list_net) 1581 { 1582 ip_tunnel_delete_nets(list_net, gre_tap_net_id, &ipgre_tap_ops); 1583 } 1584 1585 static struct pernet_operations ipgre_tap_net_ops = { 1586 .init = ipgre_tap_init_net, 1587 .exit_batch = ipgre_tap_exit_batch_net, 1588 .id = &gre_tap_net_id, 1589 .size = sizeof(struct ip_tunnel_net), 1590 }; 1591 1592 static int __net_init erspan_init_net(struct net *net) 1593 { 1594 return ip_tunnel_init_net(net, erspan_net_id, 1595 &erspan_link_ops, "erspan0"); 1596 } 1597 1598 static void __net_exit erspan_exit_batch_net(struct list_head *net_list) 1599 { 1600 ip_tunnel_delete_nets(net_list, erspan_net_id, &erspan_link_ops); 1601 } 1602 1603 static struct pernet_operations erspan_net_ops = { 1604 .init = erspan_init_net, 1605 .exit_batch = erspan_exit_batch_net, 1606 .id = &erspan_net_id, 1607 .size = sizeof(struct ip_tunnel_net), 1608 }; 1609 1610 static int __init ipgre_init(void) 1611 { 1612 int err; 1613 1614 pr_info("GRE over IPv4 tunneling driver\n"); 1615 1616 err = register_pernet_device(&ipgre_net_ops); 1617 if (err < 0) 1618 return err; 1619 1620 err = register_pernet_device(&ipgre_tap_net_ops); 1621 if (err < 0) 1622 goto pnet_tap_failed; 1623 1624 err = register_pernet_device(&erspan_net_ops); 1625 if (err < 0) 1626 goto pnet_erspan_failed; 1627 1628 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO); 1629 if (err < 0) { 1630 pr_info("%s: can't add protocol\n", __func__); 1631 goto add_proto_failed; 1632 } 1633 1634 err = rtnl_link_register(&ipgre_link_ops); 1635 if (err < 0) 1636 goto rtnl_link_failed; 1637 1638 err = rtnl_link_register(&ipgre_tap_ops); 1639 if (err < 0) 1640 goto tap_ops_failed; 1641 1642 err = rtnl_link_register(&erspan_link_ops); 1643 if (err < 0) 1644 goto erspan_link_failed; 1645 1646 return 0; 1647 1648 erspan_link_failed: 1649 rtnl_link_unregister(&ipgre_tap_ops); 1650 tap_ops_failed: 1651 rtnl_link_unregister(&ipgre_link_ops); 1652 rtnl_link_failed: 1653 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); 1654 add_proto_failed: 1655 unregister_pernet_device(&erspan_net_ops); 1656 pnet_erspan_failed: 1657 unregister_pernet_device(&ipgre_tap_net_ops); 1658 pnet_tap_failed: 1659 unregister_pernet_device(&ipgre_net_ops); 1660 return err; 1661 } 1662 1663 static void __exit ipgre_fini(void) 1664 { 1665 rtnl_link_unregister(&ipgre_tap_ops); 1666 rtnl_link_unregister(&ipgre_link_ops); 1667 rtnl_link_unregister(&erspan_link_ops); 1668 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); 1669 unregister_pernet_device(&ipgre_tap_net_ops); 1670 unregister_pernet_device(&ipgre_net_ops); 1671 unregister_pernet_device(&erspan_net_ops); 1672 } 1673 1674 module_init(ipgre_init); 1675 module_exit(ipgre_fini); 1676 MODULE_LICENSE("GPL"); 1677 MODULE_ALIAS_RTNL_LINK("gre"); 1678 MODULE_ALIAS_RTNL_LINK("gretap"); 1679 MODULE_ALIAS_RTNL_LINK("erspan"); 1680 MODULE_ALIAS_NETDEV("gre0"); 1681 MODULE_ALIAS_NETDEV("gretap0"); 1682 MODULE_ALIAS_NETDEV("erspan0"); 1683