1 /* 2 * Linux NET3: GRE over IP protocol decoder. 3 * 4 * Authors: Alexey Kuznetsov (kuznet@ms2.inr.ac.ru) 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 * 11 */ 12 13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 14 15 #include <linux/capability.h> 16 #include <linux/module.h> 17 #include <linux/types.h> 18 #include <linux/kernel.h> 19 #include <linux/slab.h> 20 #include <asm/uaccess.h> 21 #include <linux/skbuff.h> 22 #include <linux/netdevice.h> 23 #include <linux/in.h> 24 #include <linux/tcp.h> 25 #include <linux/udp.h> 26 #include <linux/if_arp.h> 27 #include <linux/if_vlan.h> 28 #include <linux/init.h> 29 #include <linux/in6.h> 30 #include <linux/inetdevice.h> 31 #include <linux/igmp.h> 32 #include <linux/netfilter_ipv4.h> 33 #include <linux/etherdevice.h> 34 #include <linux/if_ether.h> 35 36 #include <net/sock.h> 37 #include <net/ip.h> 38 #include <net/icmp.h> 39 #include <net/protocol.h> 40 #include <net/ip_tunnels.h> 41 #include <net/arp.h> 42 #include <net/checksum.h> 43 #include <net/dsfield.h> 44 #include <net/inet_ecn.h> 45 #include <net/xfrm.h> 46 #include <net/net_namespace.h> 47 #include <net/netns/generic.h> 48 #include <net/rtnetlink.h> 49 #include <net/gre.h> 50 #include <net/dst_metadata.h> 51 52 #if IS_ENABLED(CONFIG_IPV6) 53 #include <net/ipv6.h> 54 #include <net/ip6_fib.h> 55 #include <net/ip6_route.h> 56 #endif 57 58 /* 59 Problems & solutions 60 -------------------- 61 62 1. The most important issue is detecting local dead loops. 63 They would cause complete host lockup in transmit, which 64 would be "resolved" by stack overflow or, if queueing is enabled, 65 with infinite looping in net_bh. 66 67 We cannot track such dead loops during route installation, 68 it is infeasible task. The most general solutions would be 69 to keep skb->encapsulation counter (sort of local ttl), 70 and silently drop packet when it expires. It is a good 71 solution, but it supposes maintaining new variable in ALL 72 skb, even if no tunneling is used. 73 74 Current solution: xmit_recursion breaks dead loops. This is a percpu 75 counter, since when we enter the first ndo_xmit(), cpu migration is 76 forbidden. We force an exit if this counter reaches RECURSION_LIMIT 77 78 2. Networking dead loops would not kill routers, but would really 79 kill network. IP hop limit plays role of "t->recursion" in this case, 80 if we copy it from packet being encapsulated to upper header. 81 It is very good solution, but it introduces two problems: 82 83 - Routing protocols, using packets with ttl=1 (OSPF, RIP2), 84 do not work over tunnels. 85 - traceroute does not work. I planned to relay ICMP from tunnel, 86 so that this problem would be solved and traceroute output 87 would even more informative. This idea appeared to be wrong: 88 only Linux complies to rfc1812 now (yes, guys, Linux is the only 89 true router now :-)), all routers (at least, in neighbourhood of mine) 90 return only 8 bytes of payload. It is the end. 91 92 Hence, if we want that OSPF worked or traceroute said something reasonable, 93 we should search for another solution. 94 95 One of them is to parse packet trying to detect inner encapsulation 96 made by our node. It is difficult or even impossible, especially, 97 taking into account fragmentation. TO be short, ttl is not solution at all. 98 99 Current solution: The solution was UNEXPECTEDLY SIMPLE. 100 We force DF flag on tunnels with preconfigured hop limit, 101 that is ALL. :-) Well, it does not remove the problem completely, 102 but exponential growth of network traffic is changed to linear 103 (branches, that exceed pmtu are pruned) and tunnel mtu 104 rapidly degrades to value <68, where looping stops. 105 Yes, it is not good if there exists a router in the loop, 106 which does not force DF, even when encapsulating packets have DF set. 107 But it is not our problem! Nobody could accuse us, we made 108 all that we could make. Even if it is your gated who injected 109 fatal route to network, even if it were you who configured 110 fatal static route: you are innocent. :-) 111 112 Alexey Kuznetsov. 113 */ 114 115 static bool log_ecn_error = true; 116 module_param(log_ecn_error, bool, 0644); 117 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN"); 118 119 static struct rtnl_link_ops ipgre_link_ops __read_mostly; 120 static int ipgre_tunnel_init(struct net_device *dev); 121 122 static int ipgre_net_id __read_mostly; 123 static int gre_tap_net_id __read_mostly; 124 125 static int ip_gre_calc_hlen(__be16 o_flags) 126 { 127 int addend = 4; 128 129 if (o_flags & TUNNEL_CSUM) 130 addend += 4; 131 if (o_flags & TUNNEL_KEY) 132 addend += 4; 133 if (o_flags & TUNNEL_SEQ) 134 addend += 4; 135 return addend; 136 } 137 138 static __be16 gre_flags_to_tnl_flags(__be16 flags) 139 { 140 __be16 tflags = 0; 141 142 if (flags & GRE_CSUM) 143 tflags |= TUNNEL_CSUM; 144 if (flags & GRE_ROUTING) 145 tflags |= TUNNEL_ROUTING; 146 if (flags & GRE_KEY) 147 tflags |= TUNNEL_KEY; 148 if (flags & GRE_SEQ) 149 tflags |= TUNNEL_SEQ; 150 if (flags & GRE_STRICT) 151 tflags |= TUNNEL_STRICT; 152 if (flags & GRE_REC) 153 tflags |= TUNNEL_REC; 154 if (flags & GRE_VERSION) 155 tflags |= TUNNEL_VERSION; 156 157 return tflags; 158 } 159 160 static __be16 tnl_flags_to_gre_flags(__be16 tflags) 161 { 162 __be16 flags = 0; 163 164 if (tflags & TUNNEL_CSUM) 165 flags |= GRE_CSUM; 166 if (tflags & TUNNEL_ROUTING) 167 flags |= GRE_ROUTING; 168 if (tflags & TUNNEL_KEY) 169 flags |= GRE_KEY; 170 if (tflags & TUNNEL_SEQ) 171 flags |= GRE_SEQ; 172 if (tflags & TUNNEL_STRICT) 173 flags |= GRE_STRICT; 174 if (tflags & TUNNEL_REC) 175 flags |= GRE_REC; 176 if (tflags & TUNNEL_VERSION) 177 flags |= GRE_VERSION; 178 179 return flags; 180 } 181 182 static int parse_gre_header(struct sk_buff *skb, struct tnl_ptk_info *tpi, 183 bool *csum_err) 184 { 185 const struct gre_base_hdr *greh; 186 __be32 *options; 187 int hdr_len; 188 189 if (unlikely(!pskb_may_pull(skb, sizeof(struct gre_base_hdr)))) 190 return -EINVAL; 191 192 greh = (struct gre_base_hdr *)skb_transport_header(skb); 193 if (unlikely(greh->flags & (GRE_VERSION | GRE_ROUTING))) 194 return -EINVAL; 195 196 tpi->flags = gre_flags_to_tnl_flags(greh->flags); 197 hdr_len = ip_gre_calc_hlen(tpi->flags); 198 199 if (!pskb_may_pull(skb, hdr_len)) 200 return -EINVAL; 201 202 greh = (struct gre_base_hdr *)skb_transport_header(skb); 203 tpi->proto = greh->protocol; 204 205 options = (__be32 *)(greh + 1); 206 if (greh->flags & GRE_CSUM) { 207 if (skb_checksum_simple_validate(skb)) { 208 *csum_err = true; 209 return -EINVAL; 210 } 211 212 skb_checksum_try_convert(skb, IPPROTO_GRE, 0, 213 null_compute_pseudo); 214 options++; 215 } 216 217 if (greh->flags & GRE_KEY) { 218 tpi->key = *options; 219 options++; 220 } else { 221 tpi->key = 0; 222 } 223 if (unlikely(greh->flags & GRE_SEQ)) { 224 tpi->seq = *options; 225 options++; 226 } else { 227 tpi->seq = 0; 228 } 229 /* WCCP version 1 and 2 protocol decoding. 230 * - Change protocol to IP 231 * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header 232 */ 233 if (greh->flags == 0 && tpi->proto == htons(ETH_P_WCCP)) { 234 tpi->proto = htons(ETH_P_IP); 235 if ((*(u8 *)options & 0xF0) != 0x40) { 236 hdr_len += 4; 237 if (!pskb_may_pull(skb, hdr_len)) 238 return -EINVAL; 239 } 240 } 241 return iptunnel_pull_header(skb, hdr_len, tpi->proto); 242 } 243 244 static void ipgre_err(struct sk_buff *skb, u32 info, 245 const struct tnl_ptk_info *tpi) 246 { 247 248 /* All the routers (except for Linux) return only 249 8 bytes of packet payload. It means, that precise relaying of 250 ICMP in the real Internet is absolutely infeasible. 251 252 Moreover, Cisco "wise men" put GRE key to the third word 253 in GRE header. It makes impossible maintaining even soft 254 state for keyed GRE tunnels with enabled checksum. Tell 255 them "thank you". 256 257 Well, I wonder, rfc1812 was written by Cisco employee, 258 what the hell these idiots break standards established 259 by themselves??? 260 */ 261 struct net *net = dev_net(skb->dev); 262 struct ip_tunnel_net *itn; 263 const struct iphdr *iph; 264 const int type = icmp_hdr(skb)->type; 265 const int code = icmp_hdr(skb)->code; 266 struct ip_tunnel *t; 267 268 switch (type) { 269 default: 270 case ICMP_PARAMETERPROB: 271 return; 272 273 case ICMP_DEST_UNREACH: 274 switch (code) { 275 case ICMP_SR_FAILED: 276 case ICMP_PORT_UNREACH: 277 /* Impossible event. */ 278 return; 279 default: 280 /* All others are translated to HOST_UNREACH. 281 rfc2003 contains "deep thoughts" about NET_UNREACH, 282 I believe they are just ether pollution. --ANK 283 */ 284 break; 285 } 286 break; 287 288 case ICMP_TIME_EXCEEDED: 289 if (code != ICMP_EXC_TTL) 290 return; 291 break; 292 293 case ICMP_REDIRECT: 294 break; 295 } 296 297 if (tpi->proto == htons(ETH_P_TEB)) 298 itn = net_generic(net, gre_tap_net_id); 299 else 300 itn = net_generic(net, ipgre_net_id); 301 302 iph = (const struct iphdr *)(icmp_hdr(skb) + 1); 303 t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags, 304 iph->daddr, iph->saddr, tpi->key); 305 306 if (!t) 307 return; 308 309 if (t->parms.iph.daddr == 0 || 310 ipv4_is_multicast(t->parms.iph.daddr)) 311 return; 312 313 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 314 return; 315 316 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) 317 t->err_count++; 318 else 319 t->err_count = 1; 320 t->err_time = jiffies; 321 } 322 323 static void gre_err(struct sk_buff *skb, u32 info) 324 { 325 /* All the routers (except for Linux) return only 326 * 8 bytes of packet payload. It means, that precise relaying of 327 * ICMP in the real Internet is absolutely infeasible. 328 * 329 * Moreover, Cisco "wise men" put GRE key to the third word 330 * in GRE header. It makes impossible maintaining even soft 331 * state for keyed 332 * GRE tunnels with enabled checksum. Tell them "thank you". 333 * 334 * Well, I wonder, rfc1812 was written by Cisco employee, 335 * what the hell these idiots break standards established 336 * by themselves??? 337 */ 338 339 const int type = icmp_hdr(skb)->type; 340 const int code = icmp_hdr(skb)->code; 341 struct tnl_ptk_info tpi; 342 bool csum_err = false; 343 344 if (parse_gre_header(skb, &tpi, &csum_err)) { 345 if (!csum_err) /* ignore csum errors. */ 346 return; 347 } 348 349 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { 350 ipv4_update_pmtu(skb, dev_net(skb->dev), info, 351 skb->dev->ifindex, 0, IPPROTO_GRE, 0); 352 return; 353 } 354 if (type == ICMP_REDIRECT) { 355 ipv4_redirect(skb, dev_net(skb->dev), skb->dev->ifindex, 0, 356 IPPROTO_GRE, 0); 357 return; 358 } 359 360 ipgre_err(skb, info, &tpi); 361 } 362 363 static __be64 key_to_tunnel_id(__be32 key) 364 { 365 #ifdef __BIG_ENDIAN 366 return (__force __be64)((__force u32)key); 367 #else 368 return (__force __be64)((__force u64)key << 32); 369 #endif 370 } 371 372 /* Returns the least-significant 32 bits of a __be64. */ 373 static __be32 tunnel_id_to_key(__be64 x) 374 { 375 #ifdef __BIG_ENDIAN 376 return (__force __be32)x; 377 #else 378 return (__force __be32)((__force u64)x >> 32); 379 #endif 380 } 381 382 static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi) 383 { 384 struct net *net = dev_net(skb->dev); 385 struct metadata_dst *tun_dst = NULL; 386 struct ip_tunnel_net *itn; 387 const struct iphdr *iph; 388 struct ip_tunnel *tunnel; 389 390 if (tpi->proto == htons(ETH_P_TEB)) 391 itn = net_generic(net, gre_tap_net_id); 392 else 393 itn = net_generic(net, ipgre_net_id); 394 395 iph = ip_hdr(skb); 396 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags, 397 iph->saddr, iph->daddr, tpi->key); 398 399 if (tunnel) { 400 skb_pop_mac_header(skb); 401 if (tunnel->collect_md) { 402 __be16 flags; 403 __be64 tun_id; 404 405 flags = tpi->flags & (TUNNEL_CSUM | TUNNEL_KEY); 406 tun_id = key_to_tunnel_id(tpi->key); 407 tun_dst = ip_tun_rx_dst(skb, flags, tun_id, 0); 408 if (!tun_dst) 409 return PACKET_REJECT; 410 } 411 412 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error); 413 return PACKET_RCVD; 414 } 415 return PACKET_REJECT; 416 } 417 418 static int gre_rcv(struct sk_buff *skb) 419 { 420 struct tnl_ptk_info tpi; 421 bool csum_err = false; 422 423 #ifdef CONFIG_NET_IPGRE_BROADCAST 424 if (ipv4_is_multicast(ip_hdr(skb)->daddr)) { 425 /* Looped back packet, drop it! */ 426 if (rt_is_output_route(skb_rtable(skb))) 427 goto drop; 428 } 429 #endif 430 431 if (parse_gre_header(skb, &tpi, &csum_err) < 0) 432 goto drop; 433 434 if (ipgre_rcv(skb, &tpi) == PACKET_RCVD) 435 return 0; 436 437 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 438 drop: 439 kfree_skb(skb); 440 return 0; 441 } 442 443 static void build_header(struct sk_buff *skb, int hdr_len, __be16 flags, 444 __be16 proto, __be32 key, __be32 seq) 445 { 446 struct gre_base_hdr *greh; 447 448 skb_push(skb, hdr_len); 449 450 skb_reset_transport_header(skb); 451 greh = (struct gre_base_hdr *)skb->data; 452 greh->flags = tnl_flags_to_gre_flags(flags); 453 greh->protocol = proto; 454 455 if (flags & (TUNNEL_KEY | TUNNEL_CSUM | TUNNEL_SEQ)) { 456 __be32 *ptr = (__be32 *)(((u8 *)greh) + hdr_len - 4); 457 458 if (flags & TUNNEL_SEQ) { 459 *ptr = seq; 460 ptr--; 461 } 462 if (flags & TUNNEL_KEY) { 463 *ptr = key; 464 ptr--; 465 } 466 if (flags & TUNNEL_CSUM && 467 !(skb_shinfo(skb)->gso_type & 468 (SKB_GSO_GRE | SKB_GSO_GRE_CSUM))) { 469 *ptr = 0; 470 *(__sum16 *)ptr = csum_fold(skb_checksum(skb, 0, 471 skb->len, 0)); 472 } 473 } 474 } 475 476 static void __gre_xmit(struct sk_buff *skb, struct net_device *dev, 477 const struct iphdr *tnl_params, 478 __be16 proto) 479 { 480 struct ip_tunnel *tunnel = netdev_priv(dev); 481 482 if (tunnel->parms.o_flags & TUNNEL_SEQ) 483 tunnel->o_seqno++; 484 485 /* Push GRE header. */ 486 build_header(skb, tunnel->tun_hlen, tunnel->parms.o_flags, 487 proto, tunnel->parms.o_key, htonl(tunnel->o_seqno)); 488 489 skb_set_inner_protocol(skb, proto); 490 ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol); 491 } 492 493 static struct sk_buff *gre_handle_offloads(struct sk_buff *skb, 494 bool csum) 495 { 496 return iptunnel_handle_offloads(skb, csum, 497 csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE); 498 } 499 500 static struct rtable *gre_get_rt(struct sk_buff *skb, 501 struct net_device *dev, 502 struct flowi4 *fl, 503 const struct ip_tunnel_key *key) 504 { 505 struct net *net = dev_net(dev); 506 507 memset(fl, 0, sizeof(*fl)); 508 fl->daddr = key->u.ipv4.dst; 509 fl->saddr = key->u.ipv4.src; 510 fl->flowi4_tos = RT_TOS(key->tos); 511 fl->flowi4_mark = skb->mark; 512 fl->flowi4_proto = IPPROTO_GRE; 513 514 return ip_route_output_key(net, fl); 515 } 516 517 static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev) 518 { 519 struct ip_tunnel_info *tun_info; 520 const struct ip_tunnel_key *key; 521 struct flowi4 fl; 522 struct rtable *rt; 523 int min_headroom; 524 int tunnel_hlen; 525 __be16 df, flags; 526 int err; 527 528 tun_info = skb_tunnel_info(skb); 529 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) || 530 ip_tunnel_info_af(tun_info) != AF_INET)) 531 goto err_free_skb; 532 533 key = &tun_info->key; 534 rt = gre_get_rt(skb, dev, &fl, key); 535 if (IS_ERR(rt)) 536 goto err_free_skb; 537 538 tunnel_hlen = ip_gre_calc_hlen(key->tun_flags); 539 540 min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len 541 + tunnel_hlen + sizeof(struct iphdr); 542 if (skb_headroom(skb) < min_headroom || skb_header_cloned(skb)) { 543 int head_delta = SKB_DATA_ALIGN(min_headroom - 544 skb_headroom(skb) + 545 16); 546 err = pskb_expand_head(skb, max_t(int, head_delta, 0), 547 0, GFP_ATOMIC); 548 if (unlikely(err)) 549 goto err_free_rt; 550 } 551 552 /* Push Tunnel header. */ 553 skb = gre_handle_offloads(skb, !!(tun_info->key.tun_flags & TUNNEL_CSUM)); 554 if (IS_ERR(skb)) { 555 skb = NULL; 556 goto err_free_rt; 557 } 558 559 flags = tun_info->key.tun_flags & (TUNNEL_CSUM | TUNNEL_KEY); 560 build_header(skb, tunnel_hlen, flags, htons(ETH_P_TEB), 561 tunnel_id_to_key(tun_info->key.tun_id), 0); 562 563 df = key->tun_flags & TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0; 564 565 iptunnel_xmit(skb->sk, rt, skb, fl.saddr, key->u.ipv4.dst, IPPROTO_GRE, 566 key->tos, key->ttl, df, false); 567 return; 568 569 err_free_rt: 570 ip_rt_put(rt); 571 err_free_skb: 572 kfree_skb(skb); 573 dev->stats.tx_dropped++; 574 } 575 576 static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb) 577 { 578 struct ip_tunnel_info *info = skb_tunnel_info(skb); 579 struct rtable *rt; 580 struct flowi4 fl4; 581 582 if (ip_tunnel_info_af(info) != AF_INET) 583 return -EINVAL; 584 585 rt = gre_get_rt(skb, dev, &fl4, &info->key); 586 if (IS_ERR(rt)) 587 return PTR_ERR(rt); 588 589 ip_rt_put(rt); 590 info->key.u.ipv4.src = fl4.saddr; 591 return 0; 592 } 593 594 static netdev_tx_t ipgre_xmit(struct sk_buff *skb, 595 struct net_device *dev) 596 { 597 struct ip_tunnel *tunnel = netdev_priv(dev); 598 const struct iphdr *tnl_params; 599 600 if (tunnel->collect_md) { 601 gre_fb_xmit(skb, dev); 602 return NETDEV_TX_OK; 603 } 604 605 if (dev->header_ops) { 606 /* Need space for new headers */ 607 if (skb_cow_head(skb, dev->needed_headroom - 608 (tunnel->hlen + sizeof(struct iphdr)))) 609 goto free_skb; 610 611 tnl_params = (const struct iphdr *)skb->data; 612 613 /* Pull skb since ip_tunnel_xmit() needs skb->data pointing 614 * to gre header. 615 */ 616 skb_pull(skb, tunnel->hlen + sizeof(struct iphdr)); 617 skb_reset_mac_header(skb); 618 } else { 619 if (skb_cow_head(skb, dev->needed_headroom)) 620 goto free_skb; 621 622 tnl_params = &tunnel->parms.iph; 623 } 624 625 skb = gre_handle_offloads(skb, !!(tunnel->parms.o_flags&TUNNEL_CSUM)); 626 if (IS_ERR(skb)) 627 goto out; 628 629 __gre_xmit(skb, dev, tnl_params, skb->protocol); 630 return NETDEV_TX_OK; 631 632 free_skb: 633 kfree_skb(skb); 634 out: 635 dev->stats.tx_dropped++; 636 return NETDEV_TX_OK; 637 } 638 639 static netdev_tx_t gre_tap_xmit(struct sk_buff *skb, 640 struct net_device *dev) 641 { 642 struct ip_tunnel *tunnel = netdev_priv(dev); 643 644 if (tunnel->collect_md) { 645 gre_fb_xmit(skb, dev); 646 return NETDEV_TX_OK; 647 } 648 649 skb = gre_handle_offloads(skb, !!(tunnel->parms.o_flags&TUNNEL_CSUM)); 650 if (IS_ERR(skb)) 651 goto out; 652 653 if (skb_cow_head(skb, dev->needed_headroom)) 654 goto free_skb; 655 656 __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB)); 657 return NETDEV_TX_OK; 658 659 free_skb: 660 kfree_skb(skb); 661 out: 662 dev->stats.tx_dropped++; 663 return NETDEV_TX_OK; 664 } 665 666 static int ipgre_tunnel_ioctl(struct net_device *dev, 667 struct ifreq *ifr, int cmd) 668 { 669 int err; 670 struct ip_tunnel_parm p; 671 672 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 673 return -EFAULT; 674 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) { 675 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE || 676 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) || 677 ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))) 678 return -EINVAL; 679 } 680 p.i_flags = gre_flags_to_tnl_flags(p.i_flags); 681 p.o_flags = gre_flags_to_tnl_flags(p.o_flags); 682 683 err = ip_tunnel_ioctl(dev, &p, cmd); 684 if (err) 685 return err; 686 687 p.i_flags = tnl_flags_to_gre_flags(p.i_flags); 688 p.o_flags = tnl_flags_to_gre_flags(p.o_flags); 689 690 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 691 return -EFAULT; 692 return 0; 693 } 694 695 /* Nice toy. Unfortunately, useless in real life :-) 696 It allows to construct virtual multiprotocol broadcast "LAN" 697 over the Internet, provided multicast routing is tuned. 698 699 700 I have no idea was this bicycle invented before me, 701 so that I had to set ARPHRD_IPGRE to a random value. 702 I have an impression, that Cisco could make something similar, 703 but this feature is apparently missing in IOS<=11.2(8). 704 705 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks 706 with broadcast 224.66.66.66. If you have access to mbone, play with me :-) 707 708 ping -t 255 224.66.66.66 709 710 If nobody answers, mbone does not work. 711 712 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255 713 ip addr add 10.66.66.<somewhat>/24 dev Universe 714 ifconfig Universe up 715 ifconfig Universe add fe80::<Your_real_addr>/10 716 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96 717 ftp 10.66.66.66 718 ... 719 ftp fec0:6666:6666::193.233.7.65 720 ... 721 */ 722 static int ipgre_header(struct sk_buff *skb, struct net_device *dev, 723 unsigned short type, 724 const void *daddr, const void *saddr, unsigned int len) 725 { 726 struct ip_tunnel *t = netdev_priv(dev); 727 struct iphdr *iph; 728 struct gre_base_hdr *greh; 729 730 iph = (struct iphdr *)skb_push(skb, t->hlen + sizeof(*iph)); 731 greh = (struct gre_base_hdr *)(iph+1); 732 greh->flags = tnl_flags_to_gre_flags(t->parms.o_flags); 733 greh->protocol = htons(type); 734 735 memcpy(iph, &t->parms.iph, sizeof(struct iphdr)); 736 737 /* Set the source hardware address. */ 738 if (saddr) 739 memcpy(&iph->saddr, saddr, 4); 740 if (daddr) 741 memcpy(&iph->daddr, daddr, 4); 742 if (iph->daddr) 743 return t->hlen + sizeof(*iph); 744 745 return -(t->hlen + sizeof(*iph)); 746 } 747 748 static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr) 749 { 750 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb); 751 memcpy(haddr, &iph->saddr, 4); 752 return 4; 753 } 754 755 static const struct header_ops ipgre_header_ops = { 756 .create = ipgre_header, 757 .parse = ipgre_header_parse, 758 }; 759 760 #ifdef CONFIG_NET_IPGRE_BROADCAST 761 static int ipgre_open(struct net_device *dev) 762 { 763 struct ip_tunnel *t = netdev_priv(dev); 764 765 if (ipv4_is_multicast(t->parms.iph.daddr)) { 766 struct flowi4 fl4; 767 struct rtable *rt; 768 769 rt = ip_route_output_gre(t->net, &fl4, 770 t->parms.iph.daddr, 771 t->parms.iph.saddr, 772 t->parms.o_key, 773 RT_TOS(t->parms.iph.tos), 774 t->parms.link); 775 if (IS_ERR(rt)) 776 return -EADDRNOTAVAIL; 777 dev = rt->dst.dev; 778 ip_rt_put(rt); 779 if (!__in_dev_get_rtnl(dev)) 780 return -EADDRNOTAVAIL; 781 t->mlink = dev->ifindex; 782 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr); 783 } 784 return 0; 785 } 786 787 static int ipgre_close(struct net_device *dev) 788 { 789 struct ip_tunnel *t = netdev_priv(dev); 790 791 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) { 792 struct in_device *in_dev; 793 in_dev = inetdev_by_index(t->net, t->mlink); 794 if (in_dev) 795 ip_mc_dec_group(in_dev, t->parms.iph.daddr); 796 } 797 return 0; 798 } 799 #endif 800 801 static const struct net_device_ops ipgre_netdev_ops = { 802 .ndo_init = ipgre_tunnel_init, 803 .ndo_uninit = ip_tunnel_uninit, 804 #ifdef CONFIG_NET_IPGRE_BROADCAST 805 .ndo_open = ipgre_open, 806 .ndo_stop = ipgre_close, 807 #endif 808 .ndo_start_xmit = ipgre_xmit, 809 .ndo_do_ioctl = ipgre_tunnel_ioctl, 810 .ndo_change_mtu = ip_tunnel_change_mtu, 811 .ndo_get_stats64 = ip_tunnel_get_stats64, 812 .ndo_get_iflink = ip_tunnel_get_iflink, 813 }; 814 815 #define GRE_FEATURES (NETIF_F_SG | \ 816 NETIF_F_FRAGLIST | \ 817 NETIF_F_HIGHDMA | \ 818 NETIF_F_HW_CSUM) 819 820 static void ipgre_tunnel_setup(struct net_device *dev) 821 { 822 dev->netdev_ops = &ipgre_netdev_ops; 823 dev->type = ARPHRD_IPGRE; 824 ip_tunnel_setup(dev, ipgre_net_id); 825 } 826 827 static void __gre_tunnel_init(struct net_device *dev) 828 { 829 struct ip_tunnel *tunnel; 830 int t_hlen; 831 832 tunnel = netdev_priv(dev); 833 tunnel->tun_hlen = ip_gre_calc_hlen(tunnel->parms.o_flags); 834 tunnel->parms.iph.protocol = IPPROTO_GRE; 835 836 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen; 837 838 t_hlen = tunnel->hlen + sizeof(struct iphdr); 839 840 dev->needed_headroom = LL_MAX_HEADER + t_hlen + 4; 841 dev->mtu = ETH_DATA_LEN - t_hlen - 4; 842 843 dev->features |= GRE_FEATURES; 844 dev->hw_features |= GRE_FEATURES; 845 846 if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) { 847 /* TCP offload with GRE SEQ is not supported. */ 848 dev->features |= NETIF_F_GSO_SOFTWARE; 849 dev->hw_features |= NETIF_F_GSO_SOFTWARE; 850 /* Can use a lockless transmit, unless we generate 851 * output sequences 852 */ 853 dev->features |= NETIF_F_LLTX; 854 } 855 } 856 857 static int ipgre_tunnel_init(struct net_device *dev) 858 { 859 struct ip_tunnel *tunnel = netdev_priv(dev); 860 struct iphdr *iph = &tunnel->parms.iph; 861 862 __gre_tunnel_init(dev); 863 864 memcpy(dev->dev_addr, &iph->saddr, 4); 865 memcpy(dev->broadcast, &iph->daddr, 4); 866 867 dev->flags = IFF_NOARP; 868 netif_keep_dst(dev); 869 dev->addr_len = 4; 870 871 if (iph->daddr) { 872 #ifdef CONFIG_NET_IPGRE_BROADCAST 873 if (ipv4_is_multicast(iph->daddr)) { 874 if (!iph->saddr) 875 return -EINVAL; 876 dev->flags = IFF_BROADCAST; 877 dev->header_ops = &ipgre_header_ops; 878 } 879 #endif 880 } else 881 dev->header_ops = &ipgre_header_ops; 882 883 return ip_tunnel_init(dev); 884 } 885 886 static const struct gre_protocol ipgre_protocol = { 887 .handler = gre_rcv, 888 .err_handler = gre_err, 889 }; 890 891 static int __net_init ipgre_init_net(struct net *net) 892 { 893 return ip_tunnel_init_net(net, ipgre_net_id, &ipgre_link_ops, NULL); 894 } 895 896 static void __net_exit ipgre_exit_net(struct net *net) 897 { 898 struct ip_tunnel_net *itn = net_generic(net, ipgre_net_id); 899 ip_tunnel_delete_net(itn, &ipgre_link_ops); 900 } 901 902 static struct pernet_operations ipgre_net_ops = { 903 .init = ipgre_init_net, 904 .exit = ipgre_exit_net, 905 .id = &ipgre_net_id, 906 .size = sizeof(struct ip_tunnel_net), 907 }; 908 909 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[]) 910 { 911 __be16 flags; 912 913 if (!data) 914 return 0; 915 916 flags = 0; 917 if (data[IFLA_GRE_IFLAGS]) 918 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); 919 if (data[IFLA_GRE_OFLAGS]) 920 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); 921 if (flags & (GRE_VERSION|GRE_ROUTING)) 922 return -EINVAL; 923 924 return 0; 925 } 926 927 static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[]) 928 { 929 __be32 daddr; 930 931 if (tb[IFLA_ADDRESS]) { 932 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) 933 return -EINVAL; 934 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) 935 return -EADDRNOTAVAIL; 936 } 937 938 if (!data) 939 goto out; 940 941 if (data[IFLA_GRE_REMOTE]) { 942 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4); 943 if (!daddr) 944 return -EINVAL; 945 } 946 947 out: 948 return ipgre_tunnel_validate(tb, data); 949 } 950 951 static void ipgre_netlink_parms(struct net_device *dev, 952 struct nlattr *data[], 953 struct nlattr *tb[], 954 struct ip_tunnel_parm *parms) 955 { 956 memset(parms, 0, sizeof(*parms)); 957 958 parms->iph.protocol = IPPROTO_GRE; 959 960 if (!data) 961 return; 962 963 if (data[IFLA_GRE_LINK]) 964 parms->link = nla_get_u32(data[IFLA_GRE_LINK]); 965 966 if (data[IFLA_GRE_IFLAGS]) 967 parms->i_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_IFLAGS])); 968 969 if (data[IFLA_GRE_OFLAGS]) 970 parms->o_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_OFLAGS])); 971 972 if (data[IFLA_GRE_IKEY]) 973 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]); 974 975 if (data[IFLA_GRE_OKEY]) 976 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]); 977 978 if (data[IFLA_GRE_LOCAL]) 979 parms->iph.saddr = nla_get_in_addr(data[IFLA_GRE_LOCAL]); 980 981 if (data[IFLA_GRE_REMOTE]) 982 parms->iph.daddr = nla_get_in_addr(data[IFLA_GRE_REMOTE]); 983 984 if (data[IFLA_GRE_TTL]) 985 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]); 986 987 if (data[IFLA_GRE_TOS]) 988 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]); 989 990 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC])) 991 parms->iph.frag_off = htons(IP_DF); 992 993 if (data[IFLA_GRE_COLLECT_METADATA]) { 994 struct ip_tunnel *t = netdev_priv(dev); 995 996 t->collect_md = true; 997 } 998 } 999 1000 /* This function returns true when ENCAP attributes are present in the nl msg */ 1001 static bool ipgre_netlink_encap_parms(struct nlattr *data[], 1002 struct ip_tunnel_encap *ipencap) 1003 { 1004 bool ret = false; 1005 1006 memset(ipencap, 0, sizeof(*ipencap)); 1007 1008 if (!data) 1009 return ret; 1010 1011 if (data[IFLA_GRE_ENCAP_TYPE]) { 1012 ret = true; 1013 ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]); 1014 } 1015 1016 if (data[IFLA_GRE_ENCAP_FLAGS]) { 1017 ret = true; 1018 ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]); 1019 } 1020 1021 if (data[IFLA_GRE_ENCAP_SPORT]) { 1022 ret = true; 1023 ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]); 1024 } 1025 1026 if (data[IFLA_GRE_ENCAP_DPORT]) { 1027 ret = true; 1028 ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]); 1029 } 1030 1031 return ret; 1032 } 1033 1034 static int gre_tap_init(struct net_device *dev) 1035 { 1036 __gre_tunnel_init(dev); 1037 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1038 1039 return ip_tunnel_init(dev); 1040 } 1041 1042 static const struct net_device_ops gre_tap_netdev_ops = { 1043 .ndo_init = gre_tap_init, 1044 .ndo_uninit = ip_tunnel_uninit, 1045 .ndo_start_xmit = gre_tap_xmit, 1046 .ndo_set_mac_address = eth_mac_addr, 1047 .ndo_validate_addr = eth_validate_addr, 1048 .ndo_change_mtu = ip_tunnel_change_mtu, 1049 .ndo_get_stats64 = ip_tunnel_get_stats64, 1050 .ndo_get_iflink = ip_tunnel_get_iflink, 1051 .ndo_fill_metadata_dst = gre_fill_metadata_dst, 1052 }; 1053 1054 static void ipgre_tap_setup(struct net_device *dev) 1055 { 1056 ether_setup(dev); 1057 dev->netdev_ops = &gre_tap_netdev_ops; 1058 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1059 ip_tunnel_setup(dev, gre_tap_net_id); 1060 } 1061 1062 static int ipgre_newlink(struct net *src_net, struct net_device *dev, 1063 struct nlattr *tb[], struct nlattr *data[]) 1064 { 1065 struct ip_tunnel_parm p; 1066 struct ip_tunnel_encap ipencap; 1067 1068 if (ipgre_netlink_encap_parms(data, &ipencap)) { 1069 struct ip_tunnel *t = netdev_priv(dev); 1070 int err = ip_tunnel_encap_setup(t, &ipencap); 1071 1072 if (err < 0) 1073 return err; 1074 } 1075 1076 ipgre_netlink_parms(dev, data, tb, &p); 1077 return ip_tunnel_newlink(dev, tb, &p); 1078 } 1079 1080 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[], 1081 struct nlattr *data[]) 1082 { 1083 struct ip_tunnel_parm p; 1084 struct ip_tunnel_encap ipencap; 1085 1086 if (ipgre_netlink_encap_parms(data, &ipencap)) { 1087 struct ip_tunnel *t = netdev_priv(dev); 1088 int err = ip_tunnel_encap_setup(t, &ipencap); 1089 1090 if (err < 0) 1091 return err; 1092 } 1093 1094 ipgre_netlink_parms(dev, data, tb, &p); 1095 return ip_tunnel_changelink(dev, tb, &p); 1096 } 1097 1098 static size_t ipgre_get_size(const struct net_device *dev) 1099 { 1100 return 1101 /* IFLA_GRE_LINK */ 1102 nla_total_size(4) + 1103 /* IFLA_GRE_IFLAGS */ 1104 nla_total_size(2) + 1105 /* IFLA_GRE_OFLAGS */ 1106 nla_total_size(2) + 1107 /* IFLA_GRE_IKEY */ 1108 nla_total_size(4) + 1109 /* IFLA_GRE_OKEY */ 1110 nla_total_size(4) + 1111 /* IFLA_GRE_LOCAL */ 1112 nla_total_size(4) + 1113 /* IFLA_GRE_REMOTE */ 1114 nla_total_size(4) + 1115 /* IFLA_GRE_TTL */ 1116 nla_total_size(1) + 1117 /* IFLA_GRE_TOS */ 1118 nla_total_size(1) + 1119 /* IFLA_GRE_PMTUDISC */ 1120 nla_total_size(1) + 1121 /* IFLA_GRE_ENCAP_TYPE */ 1122 nla_total_size(2) + 1123 /* IFLA_GRE_ENCAP_FLAGS */ 1124 nla_total_size(2) + 1125 /* IFLA_GRE_ENCAP_SPORT */ 1126 nla_total_size(2) + 1127 /* IFLA_GRE_ENCAP_DPORT */ 1128 nla_total_size(2) + 1129 /* IFLA_GRE_COLLECT_METADATA */ 1130 nla_total_size(0) + 1131 0; 1132 } 1133 1134 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev) 1135 { 1136 struct ip_tunnel *t = netdev_priv(dev); 1137 struct ip_tunnel_parm *p = &t->parms; 1138 1139 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) || 1140 nla_put_be16(skb, IFLA_GRE_IFLAGS, tnl_flags_to_gre_flags(p->i_flags)) || 1141 nla_put_be16(skb, IFLA_GRE_OFLAGS, tnl_flags_to_gre_flags(p->o_flags)) || 1142 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) || 1143 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) || 1144 nla_put_in_addr(skb, IFLA_GRE_LOCAL, p->iph.saddr) || 1145 nla_put_in_addr(skb, IFLA_GRE_REMOTE, p->iph.daddr) || 1146 nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) || 1147 nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) || 1148 nla_put_u8(skb, IFLA_GRE_PMTUDISC, 1149 !!(p->iph.frag_off & htons(IP_DF)))) 1150 goto nla_put_failure; 1151 1152 if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE, 1153 t->encap.type) || 1154 nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT, 1155 t->encap.sport) || 1156 nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT, 1157 t->encap.dport) || 1158 nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS, 1159 t->encap.flags)) 1160 goto nla_put_failure; 1161 1162 if (t->collect_md) { 1163 if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA)) 1164 goto nla_put_failure; 1165 } 1166 1167 return 0; 1168 1169 nla_put_failure: 1170 return -EMSGSIZE; 1171 } 1172 1173 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = { 1174 [IFLA_GRE_LINK] = { .type = NLA_U32 }, 1175 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 }, 1176 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 }, 1177 [IFLA_GRE_IKEY] = { .type = NLA_U32 }, 1178 [IFLA_GRE_OKEY] = { .type = NLA_U32 }, 1179 [IFLA_GRE_LOCAL] = { .len = FIELD_SIZEOF(struct iphdr, saddr) }, 1180 [IFLA_GRE_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) }, 1181 [IFLA_GRE_TTL] = { .type = NLA_U8 }, 1182 [IFLA_GRE_TOS] = { .type = NLA_U8 }, 1183 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 }, 1184 [IFLA_GRE_ENCAP_TYPE] = { .type = NLA_U16 }, 1185 [IFLA_GRE_ENCAP_FLAGS] = { .type = NLA_U16 }, 1186 [IFLA_GRE_ENCAP_SPORT] = { .type = NLA_U16 }, 1187 [IFLA_GRE_ENCAP_DPORT] = { .type = NLA_U16 }, 1188 [IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG }, 1189 }; 1190 1191 static struct rtnl_link_ops ipgre_link_ops __read_mostly = { 1192 .kind = "gre", 1193 .maxtype = IFLA_GRE_MAX, 1194 .policy = ipgre_policy, 1195 .priv_size = sizeof(struct ip_tunnel), 1196 .setup = ipgre_tunnel_setup, 1197 .validate = ipgre_tunnel_validate, 1198 .newlink = ipgre_newlink, 1199 .changelink = ipgre_changelink, 1200 .dellink = ip_tunnel_dellink, 1201 .get_size = ipgre_get_size, 1202 .fill_info = ipgre_fill_info, 1203 .get_link_net = ip_tunnel_get_link_net, 1204 }; 1205 1206 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = { 1207 .kind = "gretap", 1208 .maxtype = IFLA_GRE_MAX, 1209 .policy = ipgre_policy, 1210 .priv_size = sizeof(struct ip_tunnel), 1211 .setup = ipgre_tap_setup, 1212 .validate = ipgre_tap_validate, 1213 .newlink = ipgre_newlink, 1214 .changelink = ipgre_changelink, 1215 .dellink = ip_tunnel_dellink, 1216 .get_size = ipgre_get_size, 1217 .fill_info = ipgre_fill_info, 1218 .get_link_net = ip_tunnel_get_link_net, 1219 }; 1220 1221 struct net_device *gretap_fb_dev_create(struct net *net, const char *name, 1222 u8 name_assign_type) 1223 { 1224 struct nlattr *tb[IFLA_MAX + 1]; 1225 struct net_device *dev; 1226 struct ip_tunnel *t; 1227 int err; 1228 1229 memset(&tb, 0, sizeof(tb)); 1230 1231 dev = rtnl_create_link(net, name, name_assign_type, 1232 &ipgre_tap_ops, tb); 1233 if (IS_ERR(dev)) 1234 return dev; 1235 1236 /* Configure flow based GRE device. */ 1237 t = netdev_priv(dev); 1238 t->collect_md = true; 1239 1240 err = ipgre_newlink(net, dev, tb, NULL); 1241 if (err < 0) 1242 goto out; 1243 return dev; 1244 out: 1245 free_netdev(dev); 1246 return ERR_PTR(err); 1247 } 1248 EXPORT_SYMBOL_GPL(gretap_fb_dev_create); 1249 1250 static int __net_init ipgre_tap_init_net(struct net *net) 1251 { 1252 return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, "gretap0"); 1253 } 1254 1255 static void __net_exit ipgre_tap_exit_net(struct net *net) 1256 { 1257 struct ip_tunnel_net *itn = net_generic(net, gre_tap_net_id); 1258 ip_tunnel_delete_net(itn, &ipgre_tap_ops); 1259 } 1260 1261 static struct pernet_operations ipgre_tap_net_ops = { 1262 .init = ipgre_tap_init_net, 1263 .exit = ipgre_tap_exit_net, 1264 .id = &gre_tap_net_id, 1265 .size = sizeof(struct ip_tunnel_net), 1266 }; 1267 1268 static int __init ipgre_init(void) 1269 { 1270 int err; 1271 1272 pr_info("GRE over IPv4 tunneling driver\n"); 1273 1274 err = register_pernet_device(&ipgre_net_ops); 1275 if (err < 0) 1276 return err; 1277 1278 err = register_pernet_device(&ipgre_tap_net_ops); 1279 if (err < 0) 1280 goto pnet_tap_faied; 1281 1282 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO); 1283 if (err < 0) { 1284 pr_info("%s: can't add protocol\n", __func__); 1285 goto add_proto_failed; 1286 } 1287 1288 err = rtnl_link_register(&ipgre_link_ops); 1289 if (err < 0) 1290 goto rtnl_link_failed; 1291 1292 err = rtnl_link_register(&ipgre_tap_ops); 1293 if (err < 0) 1294 goto tap_ops_failed; 1295 1296 return 0; 1297 1298 tap_ops_failed: 1299 rtnl_link_unregister(&ipgre_link_ops); 1300 rtnl_link_failed: 1301 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); 1302 add_proto_failed: 1303 unregister_pernet_device(&ipgre_tap_net_ops); 1304 pnet_tap_faied: 1305 unregister_pernet_device(&ipgre_net_ops); 1306 return err; 1307 } 1308 1309 static void __exit ipgre_fini(void) 1310 { 1311 rtnl_link_unregister(&ipgre_tap_ops); 1312 rtnl_link_unregister(&ipgre_link_ops); 1313 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); 1314 unregister_pernet_device(&ipgre_tap_net_ops); 1315 unregister_pernet_device(&ipgre_net_ops); 1316 } 1317 1318 module_init(ipgre_init); 1319 module_exit(ipgre_fini); 1320 MODULE_LICENSE("GPL"); 1321 MODULE_ALIAS_RTNL_LINK("gre"); 1322 MODULE_ALIAS_RTNL_LINK("gretap"); 1323 MODULE_ALIAS_NETDEV("gre0"); 1324 MODULE_ALIAS_NETDEV("gretap0"); 1325