1 /* GTP according to GSM TS 09.60 / 3GPP TS 29.060 2 * 3 * (C) 2012-2014 by sysmocom - s.f.m.c. GmbH 4 * (C) 2016 by Pablo Neira Ayuso <pablo@netfilter.org> 5 * 6 * Author: Harald Welte <hwelte@sysmocom.de> 7 * Pablo Neira Ayuso <pablo@netfilter.org> 8 * Andreas Schultz <aschultz@travelping.com> 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License 12 * as published by the Free Software Foundation; either version 13 * 2 of the License, or (at your option) any later version. 14 */ 15 16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 17 18 #include <linux/module.h> 19 #include <linux/skbuff.h> 20 #include <linux/udp.h> 21 #include <linux/rculist.h> 22 #include <linux/jhash.h> 23 #include <linux/if_tunnel.h> 24 #include <linux/net.h> 25 #include <linux/file.h> 26 #include <linux/gtp.h> 27 28 #include <net/net_namespace.h> 29 #include <net/protocol.h> 30 #include <net/ip.h> 31 #include <net/udp.h> 32 #include <net/udp_tunnel.h> 33 #include <net/icmp.h> 34 #include <net/xfrm.h> 35 #include <net/genetlink.h> 36 #include <net/netns/generic.h> 37 #include <net/gtp.h> 38 39 /* An active session for the subscriber. */ 40 struct pdp_ctx { 41 struct hlist_node hlist_tid; 42 struct hlist_node hlist_addr; 43 44 union { 45 u64 tid; 46 struct { 47 u64 tid; 48 u16 flow; 49 } v0; 50 struct { 51 u32 i_tei; 52 u32 o_tei; 53 } v1; 54 } u; 55 u8 gtp_version; 56 u16 af; 57 58 struct in_addr ms_addr_ip4; 59 struct in_addr peer_addr_ip4; 60 61 struct sock *sk; 62 struct net_device *dev; 63 64 atomic_t tx_seq; 65 struct rcu_head rcu_head; 66 }; 67 68 /* One instance of the GTP device. */ 69 struct gtp_dev { 70 struct list_head list; 71 72 struct sock *sk0; 73 struct sock *sk1u; 74 75 struct net_device *dev; 76 77 unsigned int role; 78 unsigned int hash_size; 79 struct hlist_head *tid_hash; 80 struct hlist_head *addr_hash; 81 }; 82 83 static unsigned int gtp_net_id __read_mostly; 84 85 struct gtp_net { 86 struct list_head gtp_dev_list; 87 }; 88 89 static u32 gtp_h_initval; 90 91 static void pdp_context_delete(struct pdp_ctx *pctx); 92 93 static inline u32 gtp0_hashfn(u64 tid) 94 { 95 u32 *tid32 = (u32 *) &tid; 96 return jhash_2words(tid32[0], tid32[1], gtp_h_initval); 97 } 98 99 static inline u32 gtp1u_hashfn(u32 tid) 100 { 101 return jhash_1word(tid, gtp_h_initval); 102 } 103 104 static inline u32 ipv4_hashfn(__be32 ip) 105 { 106 return jhash_1word((__force u32)ip, gtp_h_initval); 107 } 108 109 /* Resolve a PDP context structure based on the 64bit TID. */ 110 static struct pdp_ctx *gtp0_pdp_find(struct gtp_dev *gtp, u64 tid) 111 { 112 struct hlist_head *head; 113 struct pdp_ctx *pdp; 114 115 head = >p->tid_hash[gtp0_hashfn(tid) % gtp->hash_size]; 116 117 hlist_for_each_entry_rcu(pdp, head, hlist_tid) { 118 if (pdp->gtp_version == GTP_V0 && 119 pdp->u.v0.tid == tid) 120 return pdp; 121 } 122 return NULL; 123 } 124 125 /* Resolve a PDP context structure based on the 32bit TEI. */ 126 static struct pdp_ctx *gtp1_pdp_find(struct gtp_dev *gtp, u32 tid) 127 { 128 struct hlist_head *head; 129 struct pdp_ctx *pdp; 130 131 head = >p->tid_hash[gtp1u_hashfn(tid) % gtp->hash_size]; 132 133 hlist_for_each_entry_rcu(pdp, head, hlist_tid) { 134 if (pdp->gtp_version == GTP_V1 && 135 pdp->u.v1.i_tei == tid) 136 return pdp; 137 } 138 return NULL; 139 } 140 141 /* Resolve a PDP context based on IPv4 address of MS. */ 142 static struct pdp_ctx *ipv4_pdp_find(struct gtp_dev *gtp, __be32 ms_addr) 143 { 144 struct hlist_head *head; 145 struct pdp_ctx *pdp; 146 147 head = >p->addr_hash[ipv4_hashfn(ms_addr) % gtp->hash_size]; 148 149 hlist_for_each_entry_rcu(pdp, head, hlist_addr) { 150 if (pdp->af == AF_INET && 151 pdp->ms_addr_ip4.s_addr == ms_addr) 152 return pdp; 153 } 154 155 return NULL; 156 } 157 158 static bool gtp_check_ms_ipv4(struct sk_buff *skb, struct pdp_ctx *pctx, 159 unsigned int hdrlen, unsigned int role) 160 { 161 struct iphdr *iph; 162 163 if (!pskb_may_pull(skb, hdrlen + sizeof(struct iphdr))) 164 return false; 165 166 iph = (struct iphdr *)(skb->data + hdrlen); 167 168 if (role == GTP_ROLE_SGSN) 169 return iph->daddr == pctx->ms_addr_ip4.s_addr; 170 else 171 return iph->saddr == pctx->ms_addr_ip4.s_addr; 172 } 173 174 /* Check if the inner IP address in this packet is assigned to any 175 * existing mobile subscriber. 176 */ 177 static bool gtp_check_ms(struct sk_buff *skb, struct pdp_ctx *pctx, 178 unsigned int hdrlen, unsigned int role) 179 { 180 switch (ntohs(skb->protocol)) { 181 case ETH_P_IP: 182 return gtp_check_ms_ipv4(skb, pctx, hdrlen, role); 183 } 184 return false; 185 } 186 187 static int gtp_rx(struct pdp_ctx *pctx, struct sk_buff *skb, 188 unsigned int hdrlen, unsigned int role) 189 { 190 struct pcpu_sw_netstats *stats; 191 192 if (!gtp_check_ms(skb, pctx, hdrlen, role)) { 193 netdev_dbg(pctx->dev, "No PDP ctx for this MS\n"); 194 return 1; 195 } 196 197 /* Get rid of the GTP + UDP headers. */ 198 if (iptunnel_pull_header(skb, hdrlen, skb->protocol, 199 !net_eq(sock_net(pctx->sk), dev_net(pctx->dev)))) 200 return -1; 201 202 netdev_dbg(pctx->dev, "forwarding packet from GGSN to uplink\n"); 203 204 /* Now that the UDP and the GTP header have been removed, set up the 205 * new network header. This is required by the upper layer to 206 * calculate the transport header. 207 */ 208 skb_reset_network_header(skb); 209 210 skb->dev = pctx->dev; 211 212 stats = this_cpu_ptr(pctx->dev->tstats); 213 u64_stats_update_begin(&stats->syncp); 214 stats->rx_packets++; 215 stats->rx_bytes += skb->len; 216 u64_stats_update_end(&stats->syncp); 217 218 netif_rx(skb); 219 return 0; 220 } 221 222 /* 1 means pass up to the stack, -1 means drop and 0 means decapsulated. */ 223 static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb) 224 { 225 unsigned int hdrlen = sizeof(struct udphdr) + 226 sizeof(struct gtp0_header); 227 struct gtp0_header *gtp0; 228 struct pdp_ctx *pctx; 229 230 if (!pskb_may_pull(skb, hdrlen)) 231 return -1; 232 233 gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr)); 234 235 if ((gtp0->flags >> 5) != GTP_V0) 236 return 1; 237 238 if (gtp0->type != GTP_TPDU) 239 return 1; 240 241 pctx = gtp0_pdp_find(gtp, be64_to_cpu(gtp0->tid)); 242 if (!pctx) { 243 netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb); 244 return 1; 245 } 246 247 return gtp_rx(pctx, skb, hdrlen, gtp->role); 248 } 249 250 static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb) 251 { 252 unsigned int hdrlen = sizeof(struct udphdr) + 253 sizeof(struct gtp1_header); 254 struct gtp1_header *gtp1; 255 struct pdp_ctx *pctx; 256 257 if (!pskb_may_pull(skb, hdrlen)) 258 return -1; 259 260 gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr)); 261 262 if ((gtp1->flags >> 5) != GTP_V1) 263 return 1; 264 265 if (gtp1->type != GTP_TPDU) 266 return 1; 267 268 /* From 29.060: "This field shall be present if and only if any one or 269 * more of the S, PN and E flags are set.". 270 * 271 * If any of the bit is set, then the remaining ones also have to be 272 * set. 273 */ 274 if (gtp1->flags & GTP1_F_MASK) 275 hdrlen += 4; 276 277 /* Make sure the header is larger enough, including extensions. */ 278 if (!pskb_may_pull(skb, hdrlen)) 279 return -1; 280 281 gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr)); 282 283 pctx = gtp1_pdp_find(gtp, ntohl(gtp1->tid)); 284 if (!pctx) { 285 netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb); 286 return 1; 287 } 288 289 return gtp_rx(pctx, skb, hdrlen, gtp->role); 290 } 291 292 static void gtp_encap_destroy(struct sock *sk) 293 { 294 struct gtp_dev *gtp; 295 296 gtp = rcu_dereference_sk_user_data(sk); 297 if (gtp) { 298 udp_sk(sk)->encap_type = 0; 299 rcu_assign_sk_user_data(sk, NULL); 300 sock_put(sk); 301 } 302 } 303 304 static void gtp_encap_disable_sock(struct sock *sk) 305 { 306 if (!sk) 307 return; 308 309 gtp_encap_destroy(sk); 310 } 311 312 static void gtp_encap_disable(struct gtp_dev *gtp) 313 { 314 gtp_encap_disable_sock(gtp->sk0); 315 gtp_encap_disable_sock(gtp->sk1u); 316 } 317 318 /* UDP encapsulation receive handler. See net/ipv4/udp.c. 319 * Return codes: 0: success, <0: error, >0: pass up to userspace UDP socket. 320 */ 321 static int gtp_encap_recv(struct sock *sk, struct sk_buff *skb) 322 { 323 struct gtp_dev *gtp; 324 int ret = 0; 325 326 gtp = rcu_dereference_sk_user_data(sk); 327 if (!gtp) 328 return 1; 329 330 netdev_dbg(gtp->dev, "encap_recv sk=%p\n", sk); 331 332 switch (udp_sk(sk)->encap_type) { 333 case UDP_ENCAP_GTP0: 334 netdev_dbg(gtp->dev, "received GTP0 packet\n"); 335 ret = gtp0_udp_encap_recv(gtp, skb); 336 break; 337 case UDP_ENCAP_GTP1U: 338 netdev_dbg(gtp->dev, "received GTP1U packet\n"); 339 ret = gtp1u_udp_encap_recv(gtp, skb); 340 break; 341 default: 342 ret = -1; /* Shouldn't happen. */ 343 } 344 345 switch (ret) { 346 case 1: 347 netdev_dbg(gtp->dev, "pass up to the process\n"); 348 break; 349 case 0: 350 break; 351 case -1: 352 netdev_dbg(gtp->dev, "GTP packet has been dropped\n"); 353 kfree_skb(skb); 354 ret = 0; 355 break; 356 } 357 358 return ret; 359 } 360 361 static int gtp_dev_init(struct net_device *dev) 362 { 363 struct gtp_dev *gtp = netdev_priv(dev); 364 365 gtp->dev = dev; 366 367 dev->tstats = alloc_percpu(struct pcpu_sw_netstats); 368 if (!dev->tstats) 369 return -ENOMEM; 370 371 return 0; 372 } 373 374 static void gtp_dev_uninit(struct net_device *dev) 375 { 376 struct gtp_dev *gtp = netdev_priv(dev); 377 378 gtp_encap_disable(gtp); 379 free_percpu(dev->tstats); 380 } 381 382 static struct rtable *ip4_route_output_gtp(struct flowi4 *fl4, 383 const struct sock *sk, 384 __be32 daddr) 385 { 386 memset(fl4, 0, sizeof(*fl4)); 387 fl4->flowi4_oif = sk->sk_bound_dev_if; 388 fl4->daddr = daddr; 389 fl4->saddr = inet_sk(sk)->inet_saddr; 390 fl4->flowi4_tos = RT_CONN_FLAGS(sk); 391 fl4->flowi4_proto = sk->sk_protocol; 392 393 return ip_route_output_key(sock_net(sk), fl4); 394 } 395 396 static inline void gtp0_push_header(struct sk_buff *skb, struct pdp_ctx *pctx) 397 { 398 int payload_len = skb->len; 399 struct gtp0_header *gtp0; 400 401 gtp0 = skb_push(skb, sizeof(*gtp0)); 402 403 gtp0->flags = 0x1e; /* v0, GTP-non-prime. */ 404 gtp0->type = GTP_TPDU; 405 gtp0->length = htons(payload_len); 406 gtp0->seq = htons((atomic_inc_return(&pctx->tx_seq) - 1) % 0xffff); 407 gtp0->flow = htons(pctx->u.v0.flow); 408 gtp0->number = 0xff; 409 gtp0->spare[0] = gtp0->spare[1] = gtp0->spare[2] = 0xff; 410 gtp0->tid = cpu_to_be64(pctx->u.v0.tid); 411 } 412 413 static inline void gtp1_push_header(struct sk_buff *skb, struct pdp_ctx *pctx) 414 { 415 int payload_len = skb->len; 416 struct gtp1_header *gtp1; 417 418 gtp1 = skb_push(skb, sizeof(*gtp1)); 419 420 /* Bits 8 7 6 5 4 3 2 1 421 * +--+--+--+--+--+--+--+--+ 422 * |version |PT| 0| E| S|PN| 423 * +--+--+--+--+--+--+--+--+ 424 * 0 0 1 1 1 0 0 0 425 */ 426 gtp1->flags = 0x30; /* v1, GTP-non-prime. */ 427 gtp1->type = GTP_TPDU; 428 gtp1->length = htons(payload_len); 429 gtp1->tid = htonl(pctx->u.v1.o_tei); 430 431 /* TODO: Suppport for extension header, sequence number and N-PDU. 432 * Update the length field if any of them is available. 433 */ 434 } 435 436 struct gtp_pktinfo { 437 struct sock *sk; 438 struct iphdr *iph; 439 struct flowi4 fl4; 440 struct rtable *rt; 441 struct pdp_ctx *pctx; 442 struct net_device *dev; 443 __be16 gtph_port; 444 }; 445 446 static void gtp_push_header(struct sk_buff *skb, struct gtp_pktinfo *pktinfo) 447 { 448 switch (pktinfo->pctx->gtp_version) { 449 case GTP_V0: 450 pktinfo->gtph_port = htons(GTP0_PORT); 451 gtp0_push_header(skb, pktinfo->pctx); 452 break; 453 case GTP_V1: 454 pktinfo->gtph_port = htons(GTP1U_PORT); 455 gtp1_push_header(skb, pktinfo->pctx); 456 break; 457 } 458 } 459 460 static inline void gtp_set_pktinfo_ipv4(struct gtp_pktinfo *pktinfo, 461 struct sock *sk, struct iphdr *iph, 462 struct pdp_ctx *pctx, struct rtable *rt, 463 struct flowi4 *fl4, 464 struct net_device *dev) 465 { 466 pktinfo->sk = sk; 467 pktinfo->iph = iph; 468 pktinfo->pctx = pctx; 469 pktinfo->rt = rt; 470 pktinfo->fl4 = *fl4; 471 pktinfo->dev = dev; 472 } 473 474 static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev, 475 struct gtp_pktinfo *pktinfo) 476 { 477 struct gtp_dev *gtp = netdev_priv(dev); 478 struct pdp_ctx *pctx; 479 struct rtable *rt; 480 struct flowi4 fl4; 481 struct iphdr *iph; 482 __be16 df; 483 int mtu; 484 485 /* Read the IP destination address and resolve the PDP context. 486 * Prepend PDP header with TEI/TID from PDP ctx. 487 */ 488 iph = ip_hdr(skb); 489 if (gtp->role == GTP_ROLE_SGSN) 490 pctx = ipv4_pdp_find(gtp, iph->saddr); 491 else 492 pctx = ipv4_pdp_find(gtp, iph->daddr); 493 494 if (!pctx) { 495 netdev_dbg(dev, "no PDP ctx found for %pI4, skip\n", 496 &iph->daddr); 497 return -ENOENT; 498 } 499 netdev_dbg(dev, "found PDP context %p\n", pctx); 500 501 rt = ip4_route_output_gtp(&fl4, pctx->sk, pctx->peer_addr_ip4.s_addr); 502 if (IS_ERR(rt)) { 503 netdev_dbg(dev, "no route to SSGN %pI4\n", 504 &pctx->peer_addr_ip4.s_addr); 505 dev->stats.tx_carrier_errors++; 506 goto err; 507 } 508 509 if (rt->dst.dev == dev) { 510 netdev_dbg(dev, "circular route to SSGN %pI4\n", 511 &pctx->peer_addr_ip4.s_addr); 512 dev->stats.collisions++; 513 goto err_rt; 514 } 515 516 skb_dst_drop(skb); 517 518 /* This is similar to tnl_update_pmtu(). */ 519 df = iph->frag_off; 520 if (df) { 521 mtu = dst_mtu(&rt->dst) - dev->hard_header_len - 522 sizeof(struct iphdr) - sizeof(struct udphdr); 523 switch (pctx->gtp_version) { 524 case GTP_V0: 525 mtu -= sizeof(struct gtp0_header); 526 break; 527 case GTP_V1: 528 mtu -= sizeof(struct gtp1_header); 529 break; 530 } 531 } else { 532 mtu = dst_mtu(&rt->dst); 533 } 534 535 rt->dst.ops->update_pmtu(&rt->dst, NULL, skb, mtu); 536 537 if (!skb_is_gso(skb) && (iph->frag_off & htons(IP_DF)) && 538 mtu < ntohs(iph->tot_len)) { 539 netdev_dbg(dev, "packet too big, fragmentation needed\n"); 540 memset(IPCB(skb), 0, sizeof(*IPCB(skb))); 541 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, 542 htonl(mtu)); 543 goto err_rt; 544 } 545 546 gtp_set_pktinfo_ipv4(pktinfo, pctx->sk, iph, pctx, rt, &fl4, dev); 547 gtp_push_header(skb, pktinfo); 548 549 return 0; 550 err_rt: 551 ip_rt_put(rt); 552 err: 553 return -EBADMSG; 554 } 555 556 static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev) 557 { 558 unsigned int proto = ntohs(skb->protocol); 559 struct gtp_pktinfo pktinfo; 560 int err; 561 562 /* Ensure there is sufficient headroom. */ 563 if (skb_cow_head(skb, dev->needed_headroom)) 564 goto tx_err; 565 566 skb_reset_inner_headers(skb); 567 568 /* PDP context lookups in gtp_build_skb_*() need rcu read-side lock. */ 569 rcu_read_lock(); 570 switch (proto) { 571 case ETH_P_IP: 572 err = gtp_build_skb_ip4(skb, dev, &pktinfo); 573 break; 574 default: 575 err = -EOPNOTSUPP; 576 break; 577 } 578 rcu_read_unlock(); 579 580 if (err < 0) 581 goto tx_err; 582 583 switch (proto) { 584 case ETH_P_IP: 585 netdev_dbg(pktinfo.dev, "gtp -> IP src: %pI4 dst: %pI4\n", 586 &pktinfo.iph->saddr, &pktinfo.iph->daddr); 587 udp_tunnel_xmit_skb(pktinfo.rt, pktinfo.sk, skb, 588 pktinfo.fl4.saddr, pktinfo.fl4.daddr, 589 pktinfo.iph->tos, 590 ip4_dst_hoplimit(&pktinfo.rt->dst), 591 0, 592 pktinfo.gtph_port, pktinfo.gtph_port, 593 true, false); 594 break; 595 } 596 597 return NETDEV_TX_OK; 598 tx_err: 599 dev->stats.tx_errors++; 600 dev_kfree_skb(skb); 601 return NETDEV_TX_OK; 602 } 603 604 static const struct net_device_ops gtp_netdev_ops = { 605 .ndo_init = gtp_dev_init, 606 .ndo_uninit = gtp_dev_uninit, 607 .ndo_start_xmit = gtp_dev_xmit, 608 .ndo_get_stats64 = ip_tunnel_get_stats64, 609 }; 610 611 static void gtp_link_setup(struct net_device *dev) 612 { 613 dev->netdev_ops = >p_netdev_ops; 614 dev->needs_free_netdev = true; 615 616 dev->hard_header_len = 0; 617 dev->addr_len = 0; 618 619 /* Zero header length. */ 620 dev->type = ARPHRD_NONE; 621 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 622 623 dev->priv_flags |= IFF_NO_QUEUE; 624 dev->features |= NETIF_F_LLTX; 625 netif_keep_dst(dev); 626 627 /* Assume largest header, ie. GTPv0. */ 628 dev->needed_headroom = LL_MAX_HEADER + 629 sizeof(struct iphdr) + 630 sizeof(struct udphdr) + 631 sizeof(struct gtp0_header); 632 } 633 634 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize); 635 static void gtp_hashtable_free(struct gtp_dev *gtp); 636 static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]); 637 638 static int gtp_newlink(struct net *src_net, struct net_device *dev, 639 struct nlattr *tb[], struct nlattr *data[], 640 struct netlink_ext_ack *extack) 641 { 642 struct gtp_dev *gtp; 643 struct gtp_net *gn; 644 int hashsize, err; 645 646 if (!data[IFLA_GTP_FD0] && !data[IFLA_GTP_FD1]) 647 return -EINVAL; 648 649 gtp = netdev_priv(dev); 650 651 err = gtp_encap_enable(gtp, data); 652 if (err < 0) 653 return err; 654 655 if (!data[IFLA_GTP_PDP_HASHSIZE]) 656 hashsize = 1024; 657 else 658 hashsize = nla_get_u32(data[IFLA_GTP_PDP_HASHSIZE]); 659 660 err = gtp_hashtable_new(gtp, hashsize); 661 if (err < 0) 662 goto out_encap; 663 664 err = register_netdevice(dev); 665 if (err < 0) { 666 netdev_dbg(dev, "failed to register new netdev %d\n", err); 667 goto out_hashtable; 668 } 669 670 gn = net_generic(dev_net(dev), gtp_net_id); 671 list_add_rcu(>p->list, &gn->gtp_dev_list); 672 673 netdev_dbg(dev, "registered new GTP interface\n"); 674 675 return 0; 676 677 out_hashtable: 678 gtp_hashtable_free(gtp); 679 out_encap: 680 gtp_encap_disable(gtp); 681 return err; 682 } 683 684 static void gtp_dellink(struct net_device *dev, struct list_head *head) 685 { 686 struct gtp_dev *gtp = netdev_priv(dev); 687 688 gtp_encap_disable(gtp); 689 gtp_hashtable_free(gtp); 690 list_del_rcu(>p->list); 691 unregister_netdevice_queue(dev, head); 692 } 693 694 static const struct nla_policy gtp_policy[IFLA_GTP_MAX + 1] = { 695 [IFLA_GTP_FD0] = { .type = NLA_U32 }, 696 [IFLA_GTP_FD1] = { .type = NLA_U32 }, 697 [IFLA_GTP_PDP_HASHSIZE] = { .type = NLA_U32 }, 698 [IFLA_GTP_ROLE] = { .type = NLA_U32 }, 699 }; 700 701 static int gtp_validate(struct nlattr *tb[], struct nlattr *data[], 702 struct netlink_ext_ack *extack) 703 { 704 if (!data) 705 return -EINVAL; 706 707 return 0; 708 } 709 710 static size_t gtp_get_size(const struct net_device *dev) 711 { 712 return nla_total_size(sizeof(__u32)); /* IFLA_GTP_PDP_HASHSIZE */ 713 } 714 715 static int gtp_fill_info(struct sk_buff *skb, const struct net_device *dev) 716 { 717 struct gtp_dev *gtp = netdev_priv(dev); 718 719 if (nla_put_u32(skb, IFLA_GTP_PDP_HASHSIZE, gtp->hash_size)) 720 goto nla_put_failure; 721 722 return 0; 723 724 nla_put_failure: 725 return -EMSGSIZE; 726 } 727 728 static struct rtnl_link_ops gtp_link_ops __read_mostly = { 729 .kind = "gtp", 730 .maxtype = IFLA_GTP_MAX, 731 .policy = gtp_policy, 732 .priv_size = sizeof(struct gtp_dev), 733 .setup = gtp_link_setup, 734 .validate = gtp_validate, 735 .newlink = gtp_newlink, 736 .dellink = gtp_dellink, 737 .get_size = gtp_get_size, 738 .fill_info = gtp_fill_info, 739 }; 740 741 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize) 742 { 743 int i; 744 745 gtp->addr_hash = kmalloc(sizeof(struct hlist_head) * hsize, GFP_KERNEL); 746 if (gtp->addr_hash == NULL) 747 return -ENOMEM; 748 749 gtp->tid_hash = kmalloc(sizeof(struct hlist_head) * hsize, GFP_KERNEL); 750 if (gtp->tid_hash == NULL) 751 goto err1; 752 753 gtp->hash_size = hsize; 754 755 for (i = 0; i < hsize; i++) { 756 INIT_HLIST_HEAD(>p->addr_hash[i]); 757 INIT_HLIST_HEAD(>p->tid_hash[i]); 758 } 759 return 0; 760 err1: 761 kfree(gtp->addr_hash); 762 return -ENOMEM; 763 } 764 765 static void gtp_hashtable_free(struct gtp_dev *gtp) 766 { 767 struct pdp_ctx *pctx; 768 int i; 769 770 for (i = 0; i < gtp->hash_size; i++) 771 hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], hlist_tid) 772 pdp_context_delete(pctx); 773 774 synchronize_rcu(); 775 kfree(gtp->addr_hash); 776 kfree(gtp->tid_hash); 777 } 778 779 static struct sock *gtp_encap_enable_socket(int fd, int type, 780 struct gtp_dev *gtp) 781 { 782 struct udp_tunnel_sock_cfg tuncfg = {NULL}; 783 struct socket *sock; 784 struct sock *sk; 785 int err; 786 787 pr_debug("enable gtp on %d, %d\n", fd, type); 788 789 sock = sockfd_lookup(fd, &err); 790 if (!sock) { 791 pr_debug("gtp socket fd=%d not found\n", fd); 792 return NULL; 793 } 794 795 if (sock->sk->sk_protocol != IPPROTO_UDP) { 796 pr_debug("socket fd=%d not UDP\n", fd); 797 sk = ERR_PTR(-EINVAL); 798 goto out_sock; 799 } 800 801 if (rcu_dereference_sk_user_data(sock->sk)) { 802 sk = ERR_PTR(-EBUSY); 803 goto out_sock; 804 } 805 806 sk = sock->sk; 807 sock_hold(sk); 808 809 tuncfg.sk_user_data = gtp; 810 tuncfg.encap_type = type; 811 tuncfg.encap_rcv = gtp_encap_recv; 812 tuncfg.encap_destroy = gtp_encap_destroy; 813 814 setup_udp_tunnel_sock(sock_net(sock->sk), sock, &tuncfg); 815 816 out_sock: 817 sockfd_put(sock); 818 return sk; 819 } 820 821 static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]) 822 { 823 struct sock *sk1u = NULL; 824 struct sock *sk0 = NULL; 825 unsigned int role = GTP_ROLE_GGSN; 826 827 if (data[IFLA_GTP_FD0]) { 828 u32 fd0 = nla_get_u32(data[IFLA_GTP_FD0]); 829 830 sk0 = gtp_encap_enable_socket(fd0, UDP_ENCAP_GTP0, gtp); 831 if (IS_ERR(sk0)) 832 return PTR_ERR(sk0); 833 } 834 835 if (data[IFLA_GTP_FD1]) { 836 u32 fd1 = nla_get_u32(data[IFLA_GTP_FD1]); 837 838 sk1u = gtp_encap_enable_socket(fd1, UDP_ENCAP_GTP1U, gtp); 839 if (IS_ERR(sk1u)) { 840 if (sk0) 841 gtp_encap_disable_sock(sk0); 842 return PTR_ERR(sk1u); 843 } 844 } 845 846 if (data[IFLA_GTP_ROLE]) { 847 role = nla_get_u32(data[IFLA_GTP_ROLE]); 848 if (role > GTP_ROLE_SGSN) 849 return -EINVAL; 850 } 851 852 gtp->sk0 = sk0; 853 gtp->sk1u = sk1u; 854 gtp->role = role; 855 856 return 0; 857 } 858 859 static struct gtp_dev *gtp_find_dev(struct net *src_net, struct nlattr *nla[]) 860 { 861 struct gtp_dev *gtp = NULL; 862 struct net_device *dev; 863 struct net *net; 864 865 /* Examine the link attributes and figure out which network namespace 866 * we are talking about. 867 */ 868 if (nla[GTPA_NET_NS_FD]) 869 net = get_net_ns_by_fd(nla_get_u32(nla[GTPA_NET_NS_FD])); 870 else 871 net = get_net(src_net); 872 873 if (IS_ERR(net)) 874 return NULL; 875 876 /* Check if there's an existing gtpX device to configure */ 877 dev = dev_get_by_index_rcu(net, nla_get_u32(nla[GTPA_LINK])); 878 if (dev && dev->netdev_ops == >p_netdev_ops) 879 gtp = netdev_priv(dev); 880 881 put_net(net); 882 return gtp; 883 } 884 885 static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info) 886 { 887 pctx->gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]); 888 pctx->af = AF_INET; 889 pctx->peer_addr_ip4.s_addr = 890 nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]); 891 pctx->ms_addr_ip4.s_addr = 892 nla_get_be32(info->attrs[GTPA_MS_ADDRESS]); 893 894 switch (pctx->gtp_version) { 895 case GTP_V0: 896 /* According to TS 09.60, sections 7.5.1 and 7.5.2, the flow 897 * label needs to be the same for uplink and downlink packets, 898 * so let's annotate this. 899 */ 900 pctx->u.v0.tid = nla_get_u64(info->attrs[GTPA_TID]); 901 pctx->u.v0.flow = nla_get_u16(info->attrs[GTPA_FLOW]); 902 break; 903 case GTP_V1: 904 pctx->u.v1.i_tei = nla_get_u32(info->attrs[GTPA_I_TEI]); 905 pctx->u.v1.o_tei = nla_get_u32(info->attrs[GTPA_O_TEI]); 906 break; 907 default: 908 break; 909 } 910 } 911 912 static int ipv4_pdp_add(struct gtp_dev *gtp, struct sock *sk, 913 struct genl_info *info) 914 { 915 struct net_device *dev = gtp->dev; 916 u32 hash_ms, hash_tid = 0; 917 struct pdp_ctx *pctx; 918 bool found = false; 919 __be32 ms_addr; 920 921 ms_addr = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]); 922 hash_ms = ipv4_hashfn(ms_addr) % gtp->hash_size; 923 924 hlist_for_each_entry_rcu(pctx, >p->addr_hash[hash_ms], hlist_addr) { 925 if (pctx->ms_addr_ip4.s_addr == ms_addr) { 926 found = true; 927 break; 928 } 929 } 930 931 if (found) { 932 if (info->nlhdr->nlmsg_flags & NLM_F_EXCL) 933 return -EEXIST; 934 if (info->nlhdr->nlmsg_flags & NLM_F_REPLACE) 935 return -EOPNOTSUPP; 936 937 ipv4_pdp_fill(pctx, info); 938 939 if (pctx->gtp_version == GTP_V0) 940 netdev_dbg(dev, "GTPv0-U: update tunnel id = %llx (pdp %p)\n", 941 pctx->u.v0.tid, pctx); 942 else if (pctx->gtp_version == GTP_V1) 943 netdev_dbg(dev, "GTPv1-U: update tunnel id = %x/%x (pdp %p)\n", 944 pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx); 945 946 return 0; 947 948 } 949 950 pctx = kmalloc(sizeof(struct pdp_ctx), GFP_KERNEL); 951 if (pctx == NULL) 952 return -ENOMEM; 953 954 sock_hold(sk); 955 pctx->sk = sk; 956 pctx->dev = gtp->dev; 957 ipv4_pdp_fill(pctx, info); 958 atomic_set(&pctx->tx_seq, 0); 959 960 switch (pctx->gtp_version) { 961 case GTP_V0: 962 /* TS 09.60: "The flow label identifies unambiguously a GTP 963 * flow.". We use the tid for this instead, I cannot find a 964 * situation in which this doesn't unambiguosly identify the 965 * PDP context. 966 */ 967 hash_tid = gtp0_hashfn(pctx->u.v0.tid) % gtp->hash_size; 968 break; 969 case GTP_V1: 970 hash_tid = gtp1u_hashfn(pctx->u.v1.i_tei) % gtp->hash_size; 971 break; 972 } 973 974 hlist_add_head_rcu(&pctx->hlist_addr, >p->addr_hash[hash_ms]); 975 hlist_add_head_rcu(&pctx->hlist_tid, >p->tid_hash[hash_tid]); 976 977 switch (pctx->gtp_version) { 978 case GTP_V0: 979 netdev_dbg(dev, "GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n", 980 pctx->u.v0.tid, &pctx->peer_addr_ip4, 981 &pctx->ms_addr_ip4, pctx); 982 break; 983 case GTP_V1: 984 netdev_dbg(dev, "GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n", 985 pctx->u.v1.i_tei, pctx->u.v1.o_tei, 986 &pctx->peer_addr_ip4, &pctx->ms_addr_ip4, pctx); 987 break; 988 } 989 990 return 0; 991 } 992 993 static void pdp_context_free(struct rcu_head *head) 994 { 995 struct pdp_ctx *pctx = container_of(head, struct pdp_ctx, rcu_head); 996 997 sock_put(pctx->sk); 998 kfree(pctx); 999 } 1000 1001 static void pdp_context_delete(struct pdp_ctx *pctx) 1002 { 1003 hlist_del_rcu(&pctx->hlist_tid); 1004 hlist_del_rcu(&pctx->hlist_addr); 1005 call_rcu(&pctx->rcu_head, pdp_context_free); 1006 } 1007 1008 static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info) 1009 { 1010 unsigned int version; 1011 struct gtp_dev *gtp; 1012 struct sock *sk; 1013 int err; 1014 1015 if (!info->attrs[GTPA_VERSION] || 1016 !info->attrs[GTPA_LINK] || 1017 !info->attrs[GTPA_PEER_ADDRESS] || 1018 !info->attrs[GTPA_MS_ADDRESS]) 1019 return -EINVAL; 1020 1021 version = nla_get_u32(info->attrs[GTPA_VERSION]); 1022 1023 switch (version) { 1024 case GTP_V0: 1025 if (!info->attrs[GTPA_TID] || 1026 !info->attrs[GTPA_FLOW]) 1027 return -EINVAL; 1028 break; 1029 case GTP_V1: 1030 if (!info->attrs[GTPA_I_TEI] || 1031 !info->attrs[GTPA_O_TEI]) 1032 return -EINVAL; 1033 break; 1034 1035 default: 1036 return -EINVAL; 1037 } 1038 1039 rcu_read_lock(); 1040 1041 gtp = gtp_find_dev(sock_net(skb->sk), info->attrs); 1042 if (!gtp) { 1043 err = -ENODEV; 1044 goto out_unlock; 1045 } 1046 1047 if (version == GTP_V0) 1048 sk = gtp->sk0; 1049 else if (version == GTP_V1) 1050 sk = gtp->sk1u; 1051 else 1052 sk = NULL; 1053 1054 if (!sk) { 1055 err = -ENODEV; 1056 goto out_unlock; 1057 } 1058 1059 err = ipv4_pdp_add(gtp, sk, info); 1060 1061 out_unlock: 1062 rcu_read_unlock(); 1063 return err; 1064 } 1065 1066 static struct pdp_ctx *gtp_find_pdp_by_link(struct net *net, 1067 struct nlattr *nla[]) 1068 { 1069 struct gtp_dev *gtp; 1070 1071 gtp = gtp_find_dev(net, nla); 1072 if (!gtp) 1073 return ERR_PTR(-ENODEV); 1074 1075 if (nla[GTPA_MS_ADDRESS]) { 1076 __be32 ip = nla_get_be32(nla[GTPA_MS_ADDRESS]); 1077 1078 return ipv4_pdp_find(gtp, ip); 1079 } else if (nla[GTPA_VERSION]) { 1080 u32 gtp_version = nla_get_u32(nla[GTPA_VERSION]); 1081 1082 if (gtp_version == GTP_V0 && nla[GTPA_TID]) 1083 return gtp0_pdp_find(gtp, nla_get_u64(nla[GTPA_TID])); 1084 else if (gtp_version == GTP_V1 && nla[GTPA_I_TEI]) 1085 return gtp1_pdp_find(gtp, nla_get_u32(nla[GTPA_I_TEI])); 1086 } 1087 1088 return ERR_PTR(-EINVAL); 1089 } 1090 1091 static struct pdp_ctx *gtp_find_pdp(struct net *net, struct nlattr *nla[]) 1092 { 1093 struct pdp_ctx *pctx; 1094 1095 if (nla[GTPA_LINK]) 1096 pctx = gtp_find_pdp_by_link(net, nla); 1097 else 1098 pctx = ERR_PTR(-EINVAL); 1099 1100 if (!pctx) 1101 pctx = ERR_PTR(-ENOENT); 1102 1103 return pctx; 1104 } 1105 1106 static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info) 1107 { 1108 struct pdp_ctx *pctx; 1109 int err = 0; 1110 1111 if (!info->attrs[GTPA_VERSION]) 1112 return -EINVAL; 1113 1114 rcu_read_lock(); 1115 1116 pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs); 1117 if (IS_ERR(pctx)) { 1118 err = PTR_ERR(pctx); 1119 goto out_unlock; 1120 } 1121 1122 if (pctx->gtp_version == GTP_V0) 1123 netdev_dbg(pctx->dev, "GTPv0-U: deleting tunnel id = %llx (pdp %p)\n", 1124 pctx->u.v0.tid, pctx); 1125 else if (pctx->gtp_version == GTP_V1) 1126 netdev_dbg(pctx->dev, "GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n", 1127 pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx); 1128 1129 pdp_context_delete(pctx); 1130 1131 out_unlock: 1132 rcu_read_unlock(); 1133 return err; 1134 } 1135 1136 static struct genl_family gtp_genl_family; 1137 1138 static int gtp_genl_fill_info(struct sk_buff *skb, u32 snd_portid, u32 snd_seq, 1139 u32 type, struct pdp_ctx *pctx) 1140 { 1141 void *genlh; 1142 1143 genlh = genlmsg_put(skb, snd_portid, snd_seq, >p_genl_family, 0, 1144 type); 1145 if (genlh == NULL) 1146 goto nlmsg_failure; 1147 1148 if (nla_put_u32(skb, GTPA_VERSION, pctx->gtp_version) || 1149 nla_put_be32(skb, GTPA_PEER_ADDRESS, pctx->peer_addr_ip4.s_addr) || 1150 nla_put_be32(skb, GTPA_MS_ADDRESS, pctx->ms_addr_ip4.s_addr)) 1151 goto nla_put_failure; 1152 1153 switch (pctx->gtp_version) { 1154 case GTP_V0: 1155 if (nla_put_u64_64bit(skb, GTPA_TID, pctx->u.v0.tid, GTPA_PAD) || 1156 nla_put_u16(skb, GTPA_FLOW, pctx->u.v0.flow)) 1157 goto nla_put_failure; 1158 break; 1159 case GTP_V1: 1160 if (nla_put_u32(skb, GTPA_I_TEI, pctx->u.v1.i_tei) || 1161 nla_put_u32(skb, GTPA_O_TEI, pctx->u.v1.o_tei)) 1162 goto nla_put_failure; 1163 break; 1164 } 1165 genlmsg_end(skb, genlh); 1166 return 0; 1167 1168 nlmsg_failure: 1169 nla_put_failure: 1170 genlmsg_cancel(skb, genlh); 1171 return -EMSGSIZE; 1172 } 1173 1174 static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info) 1175 { 1176 struct pdp_ctx *pctx = NULL; 1177 struct sk_buff *skb2; 1178 int err; 1179 1180 if (!info->attrs[GTPA_VERSION]) 1181 return -EINVAL; 1182 1183 rcu_read_lock(); 1184 1185 pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs); 1186 if (IS_ERR(pctx)) { 1187 err = PTR_ERR(pctx); 1188 goto err_unlock; 1189 } 1190 1191 skb2 = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC); 1192 if (skb2 == NULL) { 1193 err = -ENOMEM; 1194 goto err_unlock; 1195 } 1196 1197 err = gtp_genl_fill_info(skb2, NETLINK_CB(skb).portid, 1198 info->snd_seq, info->nlhdr->nlmsg_type, pctx); 1199 if (err < 0) 1200 goto err_unlock_free; 1201 1202 rcu_read_unlock(); 1203 return genlmsg_unicast(genl_info_net(info), skb2, info->snd_portid); 1204 1205 err_unlock_free: 1206 kfree_skb(skb2); 1207 err_unlock: 1208 rcu_read_unlock(); 1209 return err; 1210 } 1211 1212 static int gtp_genl_dump_pdp(struct sk_buff *skb, 1213 struct netlink_callback *cb) 1214 { 1215 struct gtp_dev *last_gtp = (struct gtp_dev *)cb->args[2], *gtp; 1216 struct net *net = sock_net(skb->sk); 1217 struct gtp_net *gn = net_generic(net, gtp_net_id); 1218 unsigned long tid = cb->args[1]; 1219 int i, k = cb->args[0], ret; 1220 struct pdp_ctx *pctx; 1221 1222 if (cb->args[4]) 1223 return 0; 1224 1225 list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) { 1226 if (last_gtp && last_gtp != gtp) 1227 continue; 1228 else 1229 last_gtp = NULL; 1230 1231 for (i = k; i < gtp->hash_size; i++) { 1232 hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], hlist_tid) { 1233 if (tid && tid != pctx->u.tid) 1234 continue; 1235 else 1236 tid = 0; 1237 1238 ret = gtp_genl_fill_info(skb, 1239 NETLINK_CB(cb->skb).portid, 1240 cb->nlh->nlmsg_seq, 1241 cb->nlh->nlmsg_type, pctx); 1242 if (ret < 0) { 1243 cb->args[0] = i; 1244 cb->args[1] = pctx->u.tid; 1245 cb->args[2] = (unsigned long)gtp; 1246 goto out; 1247 } 1248 } 1249 } 1250 } 1251 cb->args[4] = 1; 1252 out: 1253 return skb->len; 1254 } 1255 1256 static struct nla_policy gtp_genl_policy[GTPA_MAX + 1] = { 1257 [GTPA_LINK] = { .type = NLA_U32, }, 1258 [GTPA_VERSION] = { .type = NLA_U32, }, 1259 [GTPA_TID] = { .type = NLA_U64, }, 1260 [GTPA_PEER_ADDRESS] = { .type = NLA_U32, }, 1261 [GTPA_MS_ADDRESS] = { .type = NLA_U32, }, 1262 [GTPA_FLOW] = { .type = NLA_U16, }, 1263 [GTPA_NET_NS_FD] = { .type = NLA_U32, }, 1264 [GTPA_I_TEI] = { .type = NLA_U32, }, 1265 [GTPA_O_TEI] = { .type = NLA_U32, }, 1266 }; 1267 1268 static const struct genl_ops gtp_genl_ops[] = { 1269 { 1270 .cmd = GTP_CMD_NEWPDP, 1271 .doit = gtp_genl_new_pdp, 1272 .policy = gtp_genl_policy, 1273 .flags = GENL_ADMIN_PERM, 1274 }, 1275 { 1276 .cmd = GTP_CMD_DELPDP, 1277 .doit = gtp_genl_del_pdp, 1278 .policy = gtp_genl_policy, 1279 .flags = GENL_ADMIN_PERM, 1280 }, 1281 { 1282 .cmd = GTP_CMD_GETPDP, 1283 .doit = gtp_genl_get_pdp, 1284 .dumpit = gtp_genl_dump_pdp, 1285 .policy = gtp_genl_policy, 1286 .flags = GENL_ADMIN_PERM, 1287 }, 1288 }; 1289 1290 static struct genl_family gtp_genl_family __ro_after_init = { 1291 .name = "gtp", 1292 .version = 0, 1293 .hdrsize = 0, 1294 .maxattr = GTPA_MAX, 1295 .netnsok = true, 1296 .module = THIS_MODULE, 1297 .ops = gtp_genl_ops, 1298 .n_ops = ARRAY_SIZE(gtp_genl_ops), 1299 }; 1300 1301 static int __net_init gtp_net_init(struct net *net) 1302 { 1303 struct gtp_net *gn = net_generic(net, gtp_net_id); 1304 1305 INIT_LIST_HEAD(&gn->gtp_dev_list); 1306 return 0; 1307 } 1308 1309 static void __net_exit gtp_net_exit(struct net *net) 1310 { 1311 struct gtp_net *gn = net_generic(net, gtp_net_id); 1312 struct gtp_dev *gtp; 1313 LIST_HEAD(list); 1314 1315 rtnl_lock(); 1316 list_for_each_entry(gtp, &gn->gtp_dev_list, list) 1317 gtp_dellink(gtp->dev, &list); 1318 1319 unregister_netdevice_many(&list); 1320 rtnl_unlock(); 1321 } 1322 1323 static struct pernet_operations gtp_net_ops = { 1324 .init = gtp_net_init, 1325 .exit = gtp_net_exit, 1326 .id = >p_net_id, 1327 .size = sizeof(struct gtp_net), 1328 }; 1329 1330 static int __init gtp_init(void) 1331 { 1332 int err; 1333 1334 get_random_bytes(>p_h_initval, sizeof(gtp_h_initval)); 1335 1336 err = rtnl_link_register(>p_link_ops); 1337 if (err < 0) 1338 goto error_out; 1339 1340 err = genl_register_family(>p_genl_family); 1341 if (err < 0) 1342 goto unreg_rtnl_link; 1343 1344 err = register_pernet_subsys(>p_net_ops); 1345 if (err < 0) 1346 goto unreg_genl_family; 1347 1348 pr_info("GTP module loaded (pdp ctx size %zd bytes)\n", 1349 sizeof(struct pdp_ctx)); 1350 return 0; 1351 1352 unreg_genl_family: 1353 genl_unregister_family(>p_genl_family); 1354 unreg_rtnl_link: 1355 rtnl_link_unregister(>p_link_ops); 1356 error_out: 1357 pr_err("error loading GTP module loaded\n"); 1358 return err; 1359 } 1360 late_initcall(gtp_init); 1361 1362 static void __exit gtp_fini(void) 1363 { 1364 unregister_pernet_subsys(>p_net_ops); 1365 genl_unregister_family(>p_genl_family); 1366 rtnl_link_unregister(>p_link_ops); 1367 1368 pr_info("GTP module unloaded\n"); 1369 } 1370 module_exit(gtp_fini); 1371 1372 MODULE_LICENSE("GPL"); 1373 MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>"); 1374 MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic"); 1375 MODULE_ALIAS_RTNL_LINK("gtp"); 1376 MODULE_ALIAS_GENL_FAMILY("gtp"); 1377