1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* GTP according to GSM TS 09.60 / 3GPP TS 29.060 3 * 4 * (C) 2012-2014 by sysmocom - s.f.m.c. GmbH 5 * (C) 2016 by Pablo Neira Ayuso <pablo@netfilter.org> 6 * 7 * Author: Harald Welte <hwelte@sysmocom.de> 8 * Pablo Neira Ayuso <pablo@netfilter.org> 9 * Andreas Schultz <aschultz@travelping.com> 10 */ 11 12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 13 14 #include <linux/module.h> 15 #include <linux/skbuff.h> 16 #include <linux/udp.h> 17 #include <linux/rculist.h> 18 #include <linux/jhash.h> 19 #include <linux/if_tunnel.h> 20 #include <linux/net.h> 21 #include <linux/file.h> 22 #include <linux/gtp.h> 23 24 #include <net/net_namespace.h> 25 #include <net/protocol.h> 26 #include <net/ip.h> 27 #include <net/udp.h> 28 #include <net/udp_tunnel.h> 29 #include <net/icmp.h> 30 #include <net/xfrm.h> 31 #include <net/genetlink.h> 32 #include <net/netns/generic.h> 33 #include <net/gtp.h> 34 35 /* An active session for the subscriber. */ 36 struct pdp_ctx { 37 struct hlist_node hlist_tid; 38 struct hlist_node hlist_addr; 39 40 union { 41 struct { 42 u64 tid; 43 u16 flow; 44 } v0; 45 struct { 46 u32 i_tei; 47 u32 o_tei; 48 } v1; 49 } u; 50 u8 gtp_version; 51 u16 af; 52 53 struct in_addr ms_addr_ip4; 54 struct in_addr peer_addr_ip4; 55 56 struct sock *sk; 57 struct net_device *dev; 58 59 atomic_t tx_seq; 60 struct rcu_head rcu_head; 61 }; 62 63 /* One instance of the GTP device. */ 64 struct gtp_dev { 65 struct list_head list; 66 67 struct sock *sk0; 68 struct sock *sk1u; 69 u8 sk_created; 70 71 struct net_device *dev; 72 struct net *net; 73 74 unsigned int role; 75 unsigned int hash_size; 76 struct hlist_head *tid_hash; 77 struct hlist_head *addr_hash; 78 79 u8 restart_count; 80 }; 81 82 struct echo_info { 83 struct in_addr ms_addr_ip4; 84 struct in_addr peer_addr_ip4; 85 u8 gtp_version; 86 }; 87 88 static unsigned int gtp_net_id __read_mostly; 89 90 struct gtp_net { 91 struct list_head gtp_dev_list; 92 }; 93 94 static u32 gtp_h_initval; 95 96 static struct genl_family gtp_genl_family; 97 98 enum gtp_multicast_groups { 99 GTP_GENL_MCGRP, 100 }; 101 102 static const struct genl_multicast_group gtp_genl_mcgrps[] = { 103 [GTP_GENL_MCGRP] = { .name = GTP_GENL_MCGRP_NAME }, 104 }; 105 106 static void pdp_context_delete(struct pdp_ctx *pctx); 107 108 static inline u32 gtp0_hashfn(u64 tid) 109 { 110 u32 *tid32 = (u32 *) &tid; 111 return jhash_2words(tid32[0], tid32[1], gtp_h_initval); 112 } 113 114 static inline u32 gtp1u_hashfn(u32 tid) 115 { 116 return jhash_1word(tid, gtp_h_initval); 117 } 118 119 static inline u32 ipv4_hashfn(__be32 ip) 120 { 121 return jhash_1word((__force u32)ip, gtp_h_initval); 122 } 123 124 /* Resolve a PDP context structure based on the 64bit TID. */ 125 static struct pdp_ctx *gtp0_pdp_find(struct gtp_dev *gtp, u64 tid) 126 { 127 struct hlist_head *head; 128 struct pdp_ctx *pdp; 129 130 head = >p->tid_hash[gtp0_hashfn(tid) % gtp->hash_size]; 131 132 hlist_for_each_entry_rcu(pdp, head, hlist_tid) { 133 if (pdp->gtp_version == GTP_V0 && 134 pdp->u.v0.tid == tid) 135 return pdp; 136 } 137 return NULL; 138 } 139 140 /* Resolve a PDP context structure based on the 32bit TEI. */ 141 static struct pdp_ctx *gtp1_pdp_find(struct gtp_dev *gtp, u32 tid) 142 { 143 struct hlist_head *head; 144 struct pdp_ctx *pdp; 145 146 head = >p->tid_hash[gtp1u_hashfn(tid) % gtp->hash_size]; 147 148 hlist_for_each_entry_rcu(pdp, head, hlist_tid) { 149 if (pdp->gtp_version == GTP_V1 && 150 pdp->u.v1.i_tei == tid) 151 return pdp; 152 } 153 return NULL; 154 } 155 156 /* Resolve a PDP context based on IPv4 address of MS. */ 157 static struct pdp_ctx *ipv4_pdp_find(struct gtp_dev *gtp, __be32 ms_addr) 158 { 159 struct hlist_head *head; 160 struct pdp_ctx *pdp; 161 162 head = >p->addr_hash[ipv4_hashfn(ms_addr) % gtp->hash_size]; 163 164 hlist_for_each_entry_rcu(pdp, head, hlist_addr) { 165 if (pdp->af == AF_INET && 166 pdp->ms_addr_ip4.s_addr == ms_addr) 167 return pdp; 168 } 169 170 return NULL; 171 } 172 173 static bool gtp_check_ms_ipv4(struct sk_buff *skb, struct pdp_ctx *pctx, 174 unsigned int hdrlen, unsigned int role) 175 { 176 struct iphdr *iph; 177 178 if (!pskb_may_pull(skb, hdrlen + sizeof(struct iphdr))) 179 return false; 180 181 iph = (struct iphdr *)(skb->data + hdrlen); 182 183 if (role == GTP_ROLE_SGSN) 184 return iph->daddr == pctx->ms_addr_ip4.s_addr; 185 else 186 return iph->saddr == pctx->ms_addr_ip4.s_addr; 187 } 188 189 /* Check if the inner IP address in this packet is assigned to any 190 * existing mobile subscriber. 191 */ 192 static bool gtp_check_ms(struct sk_buff *skb, struct pdp_ctx *pctx, 193 unsigned int hdrlen, unsigned int role) 194 { 195 switch (ntohs(skb->protocol)) { 196 case ETH_P_IP: 197 return gtp_check_ms_ipv4(skb, pctx, hdrlen, role); 198 } 199 return false; 200 } 201 202 static int gtp_rx(struct pdp_ctx *pctx, struct sk_buff *skb, 203 unsigned int hdrlen, unsigned int role) 204 { 205 if (!gtp_check_ms(skb, pctx, hdrlen, role)) { 206 netdev_dbg(pctx->dev, "No PDP ctx for this MS\n"); 207 return 1; 208 } 209 210 /* Get rid of the GTP + UDP headers. */ 211 if (iptunnel_pull_header(skb, hdrlen, skb->protocol, 212 !net_eq(sock_net(pctx->sk), dev_net(pctx->dev)))) { 213 pctx->dev->stats.rx_length_errors++; 214 goto err; 215 } 216 217 netdev_dbg(pctx->dev, "forwarding packet from GGSN to uplink\n"); 218 219 /* Now that the UDP and the GTP header have been removed, set up the 220 * new network header. This is required by the upper layer to 221 * calculate the transport header. 222 */ 223 skb_reset_network_header(skb); 224 skb_reset_mac_header(skb); 225 226 skb->dev = pctx->dev; 227 228 dev_sw_netstats_rx_add(pctx->dev, skb->len); 229 230 __netif_rx(skb); 231 return 0; 232 233 err: 234 pctx->dev->stats.rx_dropped++; 235 return -1; 236 } 237 238 static struct rtable *ip4_route_output_gtp(struct flowi4 *fl4, 239 const struct sock *sk, 240 __be32 daddr, __be32 saddr) 241 { 242 memset(fl4, 0, sizeof(*fl4)); 243 fl4->flowi4_oif = sk->sk_bound_dev_if; 244 fl4->daddr = daddr; 245 fl4->saddr = saddr; 246 fl4->flowi4_tos = ip_sock_rt_tos(sk); 247 fl4->flowi4_scope = ip_sock_rt_scope(sk); 248 fl4->flowi4_proto = sk->sk_protocol; 249 250 return ip_route_output_key(sock_net(sk), fl4); 251 } 252 253 /* GSM TS 09.60. 7.3 254 * In all Path Management messages: 255 * - TID: is not used and shall be set to 0. 256 * - Flow Label is not used and shall be set to 0 257 * In signalling messages: 258 * - number: this field is not yet used in signalling messages. 259 * It shall be set to 255 by the sender and shall be ignored 260 * by the receiver 261 * Returns true if the echo req was correct, false otherwise. 262 */ 263 static bool gtp0_validate_echo_hdr(struct gtp0_header *gtp0) 264 { 265 return !(gtp0->tid || (gtp0->flags ^ 0x1e) || 266 gtp0->number != 0xff || gtp0->flow); 267 } 268 269 /* msg_type has to be GTP_ECHO_REQ or GTP_ECHO_RSP */ 270 static void gtp0_build_echo_msg(struct gtp0_header *hdr, __u8 msg_type) 271 { 272 int len_pkt, len_hdr; 273 274 hdr->flags = 0x1e; /* v0, GTP-non-prime. */ 275 hdr->type = msg_type; 276 /* GSM TS 09.60. 7.3 In all Path Management Flow Label and TID 277 * are not used and shall be set to 0. 278 */ 279 hdr->flow = 0; 280 hdr->tid = 0; 281 hdr->number = 0xff; 282 hdr->spare[0] = 0xff; 283 hdr->spare[1] = 0xff; 284 hdr->spare[2] = 0xff; 285 286 len_pkt = sizeof(struct gtp0_packet); 287 len_hdr = sizeof(struct gtp0_header); 288 289 if (msg_type == GTP_ECHO_RSP) 290 hdr->length = htons(len_pkt - len_hdr); 291 else 292 hdr->length = 0; 293 } 294 295 static int gtp0_send_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb) 296 { 297 struct gtp0_packet *gtp_pkt; 298 struct gtp0_header *gtp0; 299 struct rtable *rt; 300 struct flowi4 fl4; 301 struct iphdr *iph; 302 __be16 seq; 303 304 gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr)); 305 306 if (!gtp0_validate_echo_hdr(gtp0)) 307 return -1; 308 309 seq = gtp0->seq; 310 311 /* pull GTP and UDP headers */ 312 skb_pull_data(skb, sizeof(struct gtp0_header) + sizeof(struct udphdr)); 313 314 gtp_pkt = skb_push(skb, sizeof(struct gtp0_packet)); 315 memset(gtp_pkt, 0, sizeof(struct gtp0_packet)); 316 317 gtp0_build_echo_msg(>p_pkt->gtp0_h, GTP_ECHO_RSP); 318 319 /* GSM TS 09.60. 7.3 The Sequence Number in a signalling response 320 * message shall be copied from the signalling request message 321 * that the GSN is replying to. 322 */ 323 gtp_pkt->gtp0_h.seq = seq; 324 325 gtp_pkt->ie.tag = GTPIE_RECOVERY; 326 gtp_pkt->ie.val = gtp->restart_count; 327 328 iph = ip_hdr(skb); 329 330 /* find route to the sender, 331 * src address becomes dst address and vice versa. 332 */ 333 rt = ip4_route_output_gtp(&fl4, gtp->sk0, iph->saddr, iph->daddr); 334 if (IS_ERR(rt)) { 335 netdev_dbg(gtp->dev, "no route for echo response from %pI4\n", 336 &iph->saddr); 337 return -1; 338 } 339 340 udp_tunnel_xmit_skb(rt, gtp->sk0, skb, 341 fl4.saddr, fl4.daddr, 342 iph->tos, 343 ip4_dst_hoplimit(&rt->dst), 344 0, 345 htons(GTP0_PORT), htons(GTP0_PORT), 346 !net_eq(sock_net(gtp->sk1u), 347 dev_net(gtp->dev)), 348 false); 349 return 0; 350 } 351 352 static int gtp_genl_fill_echo(struct sk_buff *skb, u32 snd_portid, u32 snd_seq, 353 int flags, u32 type, struct echo_info echo) 354 { 355 void *genlh; 356 357 genlh = genlmsg_put(skb, snd_portid, snd_seq, >p_genl_family, flags, 358 type); 359 if (!genlh) 360 goto failure; 361 362 if (nla_put_u32(skb, GTPA_VERSION, echo.gtp_version) || 363 nla_put_be32(skb, GTPA_PEER_ADDRESS, echo.peer_addr_ip4.s_addr) || 364 nla_put_be32(skb, GTPA_MS_ADDRESS, echo.ms_addr_ip4.s_addr)) 365 goto failure; 366 367 genlmsg_end(skb, genlh); 368 return 0; 369 370 failure: 371 genlmsg_cancel(skb, genlh); 372 return -EMSGSIZE; 373 } 374 375 static int gtp0_handle_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb) 376 { 377 struct gtp0_header *gtp0; 378 struct echo_info echo; 379 struct sk_buff *msg; 380 struct iphdr *iph; 381 int ret; 382 383 gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr)); 384 385 if (!gtp0_validate_echo_hdr(gtp0)) 386 return -1; 387 388 iph = ip_hdr(skb); 389 echo.ms_addr_ip4.s_addr = iph->daddr; 390 echo.peer_addr_ip4.s_addr = iph->saddr; 391 echo.gtp_version = GTP_V0; 392 393 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC); 394 if (!msg) 395 return -ENOMEM; 396 397 ret = gtp_genl_fill_echo(msg, 0, 0, 0, GTP_CMD_ECHOREQ, echo); 398 if (ret < 0) { 399 nlmsg_free(msg); 400 return ret; 401 } 402 403 return genlmsg_multicast_netns(>p_genl_family, dev_net(gtp->dev), 404 msg, 0, GTP_GENL_MCGRP, GFP_ATOMIC); 405 } 406 407 /* 1 means pass up to the stack, -1 means drop and 0 means decapsulated. */ 408 static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb) 409 { 410 unsigned int hdrlen = sizeof(struct udphdr) + 411 sizeof(struct gtp0_header); 412 struct gtp0_header *gtp0; 413 struct pdp_ctx *pctx; 414 415 if (!pskb_may_pull(skb, hdrlen)) 416 return -1; 417 418 gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr)); 419 420 if ((gtp0->flags >> 5) != GTP_V0) 421 return 1; 422 423 /* If the sockets were created in kernel, it means that 424 * there is no daemon running in userspace which would 425 * handle echo request. 426 */ 427 if (gtp0->type == GTP_ECHO_REQ && gtp->sk_created) 428 return gtp0_send_echo_resp(gtp, skb); 429 430 if (gtp0->type == GTP_ECHO_RSP && gtp->sk_created) 431 return gtp0_handle_echo_resp(gtp, skb); 432 433 if (gtp0->type != GTP_TPDU) 434 return 1; 435 436 pctx = gtp0_pdp_find(gtp, be64_to_cpu(gtp0->tid)); 437 if (!pctx) { 438 netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb); 439 return 1; 440 } 441 442 return gtp_rx(pctx, skb, hdrlen, gtp->role); 443 } 444 445 /* msg_type has to be GTP_ECHO_REQ or GTP_ECHO_RSP */ 446 static void gtp1u_build_echo_msg(struct gtp1_header_long *hdr, __u8 msg_type) 447 { 448 int len_pkt, len_hdr; 449 450 /* S flag must be set to 1 */ 451 hdr->flags = 0x32; /* v1, GTP-non-prime. */ 452 hdr->type = msg_type; 453 /* 3GPP TS 29.281 5.1 - TEID has to be set to 0 */ 454 hdr->tid = 0; 455 456 /* seq, npdu and next should be counted to the length of the GTP packet 457 * that's why szie of gtp1_header should be subtracted, 458 * not size of gtp1_header_long. 459 */ 460 461 len_hdr = sizeof(struct gtp1_header); 462 463 if (msg_type == GTP_ECHO_RSP) { 464 len_pkt = sizeof(struct gtp1u_packet); 465 hdr->length = htons(len_pkt - len_hdr); 466 } else { 467 /* GTP_ECHO_REQ does not carry GTP Information Element, 468 * the why gtp1_header_long is used here. 469 */ 470 len_pkt = sizeof(struct gtp1_header_long); 471 hdr->length = htons(len_pkt - len_hdr); 472 } 473 } 474 475 static int gtp1u_send_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb) 476 { 477 struct gtp1_header_long *gtp1u; 478 struct gtp1u_packet *gtp_pkt; 479 struct rtable *rt; 480 struct flowi4 fl4; 481 struct iphdr *iph; 482 483 gtp1u = (struct gtp1_header_long *)(skb->data + sizeof(struct udphdr)); 484 485 /* 3GPP TS 29.281 5.1 - For the Echo Request, Echo Response, 486 * Error Indication and Supported Extension Headers Notification 487 * messages, the S flag shall be set to 1 and TEID shall be set to 0. 488 */ 489 if (!(gtp1u->flags & GTP1_F_SEQ) || gtp1u->tid) 490 return -1; 491 492 /* pull GTP and UDP headers */ 493 skb_pull_data(skb, 494 sizeof(struct gtp1_header_long) + sizeof(struct udphdr)); 495 496 gtp_pkt = skb_push(skb, sizeof(struct gtp1u_packet)); 497 memset(gtp_pkt, 0, sizeof(struct gtp1u_packet)); 498 499 gtp1u_build_echo_msg(>p_pkt->gtp1u_h, GTP_ECHO_RSP); 500 501 /* 3GPP TS 29.281 7.7.2 - The Restart Counter value in the 502 * Recovery information element shall not be used, i.e. it shall 503 * be set to zero by the sender and shall be ignored by the receiver. 504 * The Recovery information element is mandatory due to backwards 505 * compatibility reasons. 506 */ 507 gtp_pkt->ie.tag = GTPIE_RECOVERY; 508 gtp_pkt->ie.val = 0; 509 510 iph = ip_hdr(skb); 511 512 /* find route to the sender, 513 * src address becomes dst address and vice versa. 514 */ 515 rt = ip4_route_output_gtp(&fl4, gtp->sk1u, iph->saddr, iph->daddr); 516 if (IS_ERR(rt)) { 517 netdev_dbg(gtp->dev, "no route for echo response from %pI4\n", 518 &iph->saddr); 519 return -1; 520 } 521 522 udp_tunnel_xmit_skb(rt, gtp->sk1u, skb, 523 fl4.saddr, fl4.daddr, 524 iph->tos, 525 ip4_dst_hoplimit(&rt->dst), 526 0, 527 htons(GTP1U_PORT), htons(GTP1U_PORT), 528 !net_eq(sock_net(gtp->sk1u), 529 dev_net(gtp->dev)), 530 false); 531 return 0; 532 } 533 534 static int gtp1u_handle_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb) 535 { 536 struct gtp1_header_long *gtp1u; 537 struct echo_info echo; 538 struct sk_buff *msg; 539 struct iphdr *iph; 540 int ret; 541 542 gtp1u = (struct gtp1_header_long *)(skb->data + sizeof(struct udphdr)); 543 544 /* 3GPP TS 29.281 5.1 - For the Echo Request, Echo Response, 545 * Error Indication and Supported Extension Headers Notification 546 * messages, the S flag shall be set to 1 and TEID shall be set to 0. 547 */ 548 if (!(gtp1u->flags & GTP1_F_SEQ) || gtp1u->tid) 549 return -1; 550 551 iph = ip_hdr(skb); 552 echo.ms_addr_ip4.s_addr = iph->daddr; 553 echo.peer_addr_ip4.s_addr = iph->saddr; 554 echo.gtp_version = GTP_V1; 555 556 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC); 557 if (!msg) 558 return -ENOMEM; 559 560 ret = gtp_genl_fill_echo(msg, 0, 0, 0, GTP_CMD_ECHOREQ, echo); 561 if (ret < 0) { 562 nlmsg_free(msg); 563 return ret; 564 } 565 566 return genlmsg_multicast_netns(>p_genl_family, dev_net(gtp->dev), 567 msg, 0, GTP_GENL_MCGRP, GFP_ATOMIC); 568 } 569 570 static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb) 571 { 572 unsigned int hdrlen = sizeof(struct udphdr) + 573 sizeof(struct gtp1_header); 574 struct gtp1_header *gtp1; 575 struct pdp_ctx *pctx; 576 577 if (!pskb_may_pull(skb, hdrlen)) 578 return -1; 579 580 gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr)); 581 582 if ((gtp1->flags >> 5) != GTP_V1) 583 return 1; 584 585 /* If the sockets were created in kernel, it means that 586 * there is no daemon running in userspace which would 587 * handle echo request. 588 */ 589 if (gtp1->type == GTP_ECHO_REQ && gtp->sk_created) 590 return gtp1u_send_echo_resp(gtp, skb); 591 592 if (gtp1->type == GTP_ECHO_RSP && gtp->sk_created) 593 return gtp1u_handle_echo_resp(gtp, skb); 594 595 if (gtp1->type != GTP_TPDU) 596 return 1; 597 598 /* From 29.060: "This field shall be present if and only if any one or 599 * more of the S, PN and E flags are set.". 600 * 601 * If any of the bit is set, then the remaining ones also have to be 602 * set. 603 */ 604 if (gtp1->flags & GTP1_F_MASK) 605 hdrlen += 4; 606 607 /* Make sure the header is larger enough, including extensions. */ 608 if (!pskb_may_pull(skb, hdrlen)) 609 return -1; 610 611 gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr)); 612 613 pctx = gtp1_pdp_find(gtp, ntohl(gtp1->tid)); 614 if (!pctx) { 615 netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb); 616 return 1; 617 } 618 619 return gtp_rx(pctx, skb, hdrlen, gtp->role); 620 } 621 622 static void __gtp_encap_destroy(struct sock *sk) 623 { 624 struct gtp_dev *gtp; 625 626 lock_sock(sk); 627 gtp = sk->sk_user_data; 628 if (gtp) { 629 if (gtp->sk0 == sk) 630 gtp->sk0 = NULL; 631 else 632 gtp->sk1u = NULL; 633 udp_sk(sk)->encap_type = 0; 634 rcu_assign_sk_user_data(sk, NULL); 635 release_sock(sk); 636 sock_put(sk); 637 return; 638 } 639 release_sock(sk); 640 } 641 642 static void gtp_encap_destroy(struct sock *sk) 643 { 644 rtnl_lock(); 645 __gtp_encap_destroy(sk); 646 rtnl_unlock(); 647 } 648 649 static void gtp_encap_disable_sock(struct sock *sk) 650 { 651 if (!sk) 652 return; 653 654 __gtp_encap_destroy(sk); 655 } 656 657 static void gtp_encap_disable(struct gtp_dev *gtp) 658 { 659 if (gtp->sk_created) { 660 udp_tunnel_sock_release(gtp->sk0->sk_socket); 661 udp_tunnel_sock_release(gtp->sk1u->sk_socket); 662 gtp->sk_created = false; 663 gtp->sk0 = NULL; 664 gtp->sk1u = NULL; 665 } else { 666 gtp_encap_disable_sock(gtp->sk0); 667 gtp_encap_disable_sock(gtp->sk1u); 668 } 669 } 670 671 /* UDP encapsulation receive handler. See net/ipv4/udp.c. 672 * Return codes: 0: success, <0: error, >0: pass up to userspace UDP socket. 673 */ 674 static int gtp_encap_recv(struct sock *sk, struct sk_buff *skb) 675 { 676 struct gtp_dev *gtp; 677 int ret = 0; 678 679 gtp = rcu_dereference_sk_user_data(sk); 680 if (!gtp) 681 return 1; 682 683 netdev_dbg(gtp->dev, "encap_recv sk=%p\n", sk); 684 685 switch (udp_sk(sk)->encap_type) { 686 case UDP_ENCAP_GTP0: 687 netdev_dbg(gtp->dev, "received GTP0 packet\n"); 688 ret = gtp0_udp_encap_recv(gtp, skb); 689 break; 690 case UDP_ENCAP_GTP1U: 691 netdev_dbg(gtp->dev, "received GTP1U packet\n"); 692 ret = gtp1u_udp_encap_recv(gtp, skb); 693 break; 694 default: 695 ret = -1; /* Shouldn't happen. */ 696 } 697 698 switch (ret) { 699 case 1: 700 netdev_dbg(gtp->dev, "pass up to the process\n"); 701 break; 702 case 0: 703 break; 704 case -1: 705 netdev_dbg(gtp->dev, "GTP packet has been dropped\n"); 706 kfree_skb(skb); 707 ret = 0; 708 break; 709 } 710 711 return ret; 712 } 713 714 static int gtp_dev_init(struct net_device *dev) 715 { 716 struct gtp_dev *gtp = netdev_priv(dev); 717 718 gtp->dev = dev; 719 720 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); 721 if (!dev->tstats) 722 return -ENOMEM; 723 724 return 0; 725 } 726 727 static void gtp_dev_uninit(struct net_device *dev) 728 { 729 struct gtp_dev *gtp = netdev_priv(dev); 730 731 gtp_encap_disable(gtp); 732 free_percpu(dev->tstats); 733 } 734 735 static inline void gtp0_push_header(struct sk_buff *skb, struct pdp_ctx *pctx) 736 { 737 int payload_len = skb->len; 738 struct gtp0_header *gtp0; 739 740 gtp0 = skb_push(skb, sizeof(*gtp0)); 741 742 gtp0->flags = 0x1e; /* v0, GTP-non-prime. */ 743 gtp0->type = GTP_TPDU; 744 gtp0->length = htons(payload_len); 745 gtp0->seq = htons((atomic_inc_return(&pctx->tx_seq) - 1) % 0xffff); 746 gtp0->flow = htons(pctx->u.v0.flow); 747 gtp0->number = 0xff; 748 gtp0->spare[0] = gtp0->spare[1] = gtp0->spare[2] = 0xff; 749 gtp0->tid = cpu_to_be64(pctx->u.v0.tid); 750 } 751 752 static inline void gtp1_push_header(struct sk_buff *skb, struct pdp_ctx *pctx) 753 { 754 int payload_len = skb->len; 755 struct gtp1_header *gtp1; 756 757 gtp1 = skb_push(skb, sizeof(*gtp1)); 758 759 /* Bits 8 7 6 5 4 3 2 1 760 * +--+--+--+--+--+--+--+--+ 761 * |version |PT| 0| E| S|PN| 762 * +--+--+--+--+--+--+--+--+ 763 * 0 0 1 1 1 0 0 0 764 */ 765 gtp1->flags = 0x30; /* v1, GTP-non-prime. */ 766 gtp1->type = GTP_TPDU; 767 gtp1->length = htons(payload_len); 768 gtp1->tid = htonl(pctx->u.v1.o_tei); 769 770 /* TODO: Support for extension header, sequence number and N-PDU. 771 * Update the length field if any of them is available. 772 */ 773 } 774 775 struct gtp_pktinfo { 776 struct sock *sk; 777 struct iphdr *iph; 778 struct flowi4 fl4; 779 struct rtable *rt; 780 struct pdp_ctx *pctx; 781 struct net_device *dev; 782 __be16 gtph_port; 783 }; 784 785 static void gtp_push_header(struct sk_buff *skb, struct gtp_pktinfo *pktinfo) 786 { 787 switch (pktinfo->pctx->gtp_version) { 788 case GTP_V0: 789 pktinfo->gtph_port = htons(GTP0_PORT); 790 gtp0_push_header(skb, pktinfo->pctx); 791 break; 792 case GTP_V1: 793 pktinfo->gtph_port = htons(GTP1U_PORT); 794 gtp1_push_header(skb, pktinfo->pctx); 795 break; 796 } 797 } 798 799 static inline void gtp_set_pktinfo_ipv4(struct gtp_pktinfo *pktinfo, 800 struct sock *sk, struct iphdr *iph, 801 struct pdp_ctx *pctx, struct rtable *rt, 802 struct flowi4 *fl4, 803 struct net_device *dev) 804 { 805 pktinfo->sk = sk; 806 pktinfo->iph = iph; 807 pktinfo->pctx = pctx; 808 pktinfo->rt = rt; 809 pktinfo->fl4 = *fl4; 810 pktinfo->dev = dev; 811 } 812 813 static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev, 814 struct gtp_pktinfo *pktinfo) 815 { 816 struct gtp_dev *gtp = netdev_priv(dev); 817 struct pdp_ctx *pctx; 818 struct rtable *rt; 819 struct flowi4 fl4; 820 struct iphdr *iph; 821 __be16 df; 822 int mtu; 823 824 /* Read the IP destination address and resolve the PDP context. 825 * Prepend PDP header with TEI/TID from PDP ctx. 826 */ 827 iph = ip_hdr(skb); 828 if (gtp->role == GTP_ROLE_SGSN) 829 pctx = ipv4_pdp_find(gtp, iph->saddr); 830 else 831 pctx = ipv4_pdp_find(gtp, iph->daddr); 832 833 if (!pctx) { 834 netdev_dbg(dev, "no PDP ctx found for %pI4, skip\n", 835 &iph->daddr); 836 return -ENOENT; 837 } 838 netdev_dbg(dev, "found PDP context %p\n", pctx); 839 840 rt = ip4_route_output_gtp(&fl4, pctx->sk, pctx->peer_addr_ip4.s_addr, 841 inet_sk(pctx->sk)->inet_saddr); 842 if (IS_ERR(rt)) { 843 netdev_dbg(dev, "no route to SSGN %pI4\n", 844 &pctx->peer_addr_ip4.s_addr); 845 dev->stats.tx_carrier_errors++; 846 goto err; 847 } 848 849 if (rt->dst.dev == dev) { 850 netdev_dbg(dev, "circular route to SSGN %pI4\n", 851 &pctx->peer_addr_ip4.s_addr); 852 dev->stats.collisions++; 853 goto err_rt; 854 } 855 856 /* This is similar to tnl_update_pmtu(). */ 857 df = iph->frag_off; 858 if (df) { 859 mtu = dst_mtu(&rt->dst) - dev->hard_header_len - 860 sizeof(struct iphdr) - sizeof(struct udphdr); 861 switch (pctx->gtp_version) { 862 case GTP_V0: 863 mtu -= sizeof(struct gtp0_header); 864 break; 865 case GTP_V1: 866 mtu -= sizeof(struct gtp1_header); 867 break; 868 } 869 } else { 870 mtu = dst_mtu(&rt->dst); 871 } 872 873 skb_dst_update_pmtu_no_confirm(skb, mtu); 874 875 if (!skb_is_gso(skb) && (iph->frag_off & htons(IP_DF)) && 876 mtu < ntohs(iph->tot_len)) { 877 netdev_dbg(dev, "packet too big, fragmentation needed\n"); 878 icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, 879 htonl(mtu)); 880 goto err_rt; 881 } 882 883 gtp_set_pktinfo_ipv4(pktinfo, pctx->sk, iph, pctx, rt, &fl4, dev); 884 gtp_push_header(skb, pktinfo); 885 886 return 0; 887 err_rt: 888 ip_rt_put(rt); 889 err: 890 return -EBADMSG; 891 } 892 893 static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev) 894 { 895 unsigned int proto = ntohs(skb->protocol); 896 struct gtp_pktinfo pktinfo; 897 int err; 898 899 /* Ensure there is sufficient headroom. */ 900 if (skb_cow_head(skb, dev->needed_headroom)) 901 goto tx_err; 902 903 skb_reset_inner_headers(skb); 904 905 /* PDP context lookups in gtp_build_skb_*() need rcu read-side lock. */ 906 rcu_read_lock(); 907 switch (proto) { 908 case ETH_P_IP: 909 err = gtp_build_skb_ip4(skb, dev, &pktinfo); 910 break; 911 default: 912 err = -EOPNOTSUPP; 913 break; 914 } 915 rcu_read_unlock(); 916 917 if (err < 0) 918 goto tx_err; 919 920 switch (proto) { 921 case ETH_P_IP: 922 netdev_dbg(pktinfo.dev, "gtp -> IP src: %pI4 dst: %pI4\n", 923 &pktinfo.iph->saddr, &pktinfo.iph->daddr); 924 udp_tunnel_xmit_skb(pktinfo.rt, pktinfo.sk, skb, 925 pktinfo.fl4.saddr, pktinfo.fl4.daddr, 926 pktinfo.iph->tos, 927 ip4_dst_hoplimit(&pktinfo.rt->dst), 928 0, 929 pktinfo.gtph_port, pktinfo.gtph_port, 930 !net_eq(sock_net(pktinfo.pctx->sk), 931 dev_net(dev)), 932 false); 933 break; 934 } 935 936 return NETDEV_TX_OK; 937 tx_err: 938 dev->stats.tx_errors++; 939 dev_kfree_skb(skb); 940 return NETDEV_TX_OK; 941 } 942 943 static const struct net_device_ops gtp_netdev_ops = { 944 .ndo_init = gtp_dev_init, 945 .ndo_uninit = gtp_dev_uninit, 946 .ndo_start_xmit = gtp_dev_xmit, 947 .ndo_get_stats64 = dev_get_tstats64, 948 }; 949 950 static const struct device_type gtp_type = { 951 .name = "gtp", 952 }; 953 954 static void gtp_link_setup(struct net_device *dev) 955 { 956 unsigned int max_gtp_header_len = sizeof(struct iphdr) + 957 sizeof(struct udphdr) + 958 sizeof(struct gtp0_header); 959 960 dev->netdev_ops = >p_netdev_ops; 961 dev->needs_free_netdev = true; 962 SET_NETDEV_DEVTYPE(dev, >p_type); 963 964 dev->hard_header_len = 0; 965 dev->addr_len = 0; 966 dev->mtu = ETH_DATA_LEN - max_gtp_header_len; 967 968 /* Zero header length. */ 969 dev->type = ARPHRD_NONE; 970 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 971 972 dev->priv_flags |= IFF_NO_QUEUE; 973 dev->features |= NETIF_F_LLTX; 974 netif_keep_dst(dev); 975 976 dev->needed_headroom = LL_MAX_HEADER + max_gtp_header_len; 977 } 978 979 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize); 980 static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]); 981 982 static void gtp_destructor(struct net_device *dev) 983 { 984 struct gtp_dev *gtp = netdev_priv(dev); 985 986 kfree(gtp->addr_hash); 987 kfree(gtp->tid_hash); 988 } 989 990 static struct sock *gtp_create_sock(int type, struct gtp_dev *gtp) 991 { 992 struct udp_tunnel_sock_cfg tuncfg = {}; 993 struct udp_port_cfg udp_conf = { 994 .local_ip.s_addr = htonl(INADDR_ANY), 995 .family = AF_INET, 996 }; 997 struct net *net = gtp->net; 998 struct socket *sock; 999 int err; 1000 1001 if (type == UDP_ENCAP_GTP0) 1002 udp_conf.local_udp_port = htons(GTP0_PORT); 1003 else if (type == UDP_ENCAP_GTP1U) 1004 udp_conf.local_udp_port = htons(GTP1U_PORT); 1005 else 1006 return ERR_PTR(-EINVAL); 1007 1008 err = udp_sock_create(net, &udp_conf, &sock); 1009 if (err) 1010 return ERR_PTR(err); 1011 1012 tuncfg.sk_user_data = gtp; 1013 tuncfg.encap_type = type; 1014 tuncfg.encap_rcv = gtp_encap_recv; 1015 tuncfg.encap_destroy = NULL; 1016 1017 setup_udp_tunnel_sock(net, sock, &tuncfg); 1018 1019 return sock->sk; 1020 } 1021 1022 static int gtp_create_sockets(struct gtp_dev *gtp, struct nlattr *data[]) 1023 { 1024 struct sock *sk1u = NULL; 1025 struct sock *sk0 = NULL; 1026 1027 sk0 = gtp_create_sock(UDP_ENCAP_GTP0, gtp); 1028 if (IS_ERR(sk0)) 1029 return PTR_ERR(sk0); 1030 1031 sk1u = gtp_create_sock(UDP_ENCAP_GTP1U, gtp); 1032 if (IS_ERR(sk1u)) { 1033 udp_tunnel_sock_release(sk0->sk_socket); 1034 return PTR_ERR(sk1u); 1035 } 1036 1037 gtp->sk_created = true; 1038 gtp->sk0 = sk0; 1039 gtp->sk1u = sk1u; 1040 1041 return 0; 1042 } 1043 1044 static int gtp_newlink(struct net *src_net, struct net_device *dev, 1045 struct nlattr *tb[], struct nlattr *data[], 1046 struct netlink_ext_ack *extack) 1047 { 1048 unsigned int role = GTP_ROLE_GGSN; 1049 struct gtp_dev *gtp; 1050 struct gtp_net *gn; 1051 int hashsize, err; 1052 1053 gtp = netdev_priv(dev); 1054 1055 if (!data[IFLA_GTP_PDP_HASHSIZE]) { 1056 hashsize = 1024; 1057 } else { 1058 hashsize = nla_get_u32(data[IFLA_GTP_PDP_HASHSIZE]); 1059 if (!hashsize) 1060 hashsize = 1024; 1061 } 1062 1063 if (data[IFLA_GTP_ROLE]) { 1064 role = nla_get_u32(data[IFLA_GTP_ROLE]); 1065 if (role > GTP_ROLE_SGSN) 1066 return -EINVAL; 1067 } 1068 gtp->role = role; 1069 1070 if (!data[IFLA_GTP_RESTART_COUNT]) 1071 gtp->restart_count = 0; 1072 else 1073 gtp->restart_count = nla_get_u8(data[IFLA_GTP_RESTART_COUNT]); 1074 1075 gtp->net = src_net; 1076 1077 err = gtp_hashtable_new(gtp, hashsize); 1078 if (err < 0) 1079 return err; 1080 1081 if (data[IFLA_GTP_CREATE_SOCKETS]) 1082 err = gtp_create_sockets(gtp, data); 1083 else 1084 err = gtp_encap_enable(gtp, data); 1085 if (err < 0) 1086 goto out_hashtable; 1087 1088 err = register_netdevice(dev); 1089 if (err < 0) { 1090 netdev_dbg(dev, "failed to register new netdev %d\n", err); 1091 goto out_encap; 1092 } 1093 1094 gn = net_generic(dev_net(dev), gtp_net_id); 1095 list_add_rcu(>p->list, &gn->gtp_dev_list); 1096 dev->priv_destructor = gtp_destructor; 1097 1098 netdev_dbg(dev, "registered new GTP interface\n"); 1099 1100 return 0; 1101 1102 out_encap: 1103 gtp_encap_disable(gtp); 1104 out_hashtable: 1105 kfree(gtp->addr_hash); 1106 kfree(gtp->tid_hash); 1107 return err; 1108 } 1109 1110 static void gtp_dellink(struct net_device *dev, struct list_head *head) 1111 { 1112 struct gtp_dev *gtp = netdev_priv(dev); 1113 struct pdp_ctx *pctx; 1114 int i; 1115 1116 for (i = 0; i < gtp->hash_size; i++) 1117 hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], hlist_tid) 1118 pdp_context_delete(pctx); 1119 1120 list_del_rcu(>p->list); 1121 unregister_netdevice_queue(dev, head); 1122 } 1123 1124 static const struct nla_policy gtp_policy[IFLA_GTP_MAX + 1] = { 1125 [IFLA_GTP_FD0] = { .type = NLA_U32 }, 1126 [IFLA_GTP_FD1] = { .type = NLA_U32 }, 1127 [IFLA_GTP_PDP_HASHSIZE] = { .type = NLA_U32 }, 1128 [IFLA_GTP_ROLE] = { .type = NLA_U32 }, 1129 [IFLA_GTP_CREATE_SOCKETS] = { .type = NLA_U8 }, 1130 [IFLA_GTP_RESTART_COUNT] = { .type = NLA_U8 }, 1131 }; 1132 1133 static int gtp_validate(struct nlattr *tb[], struct nlattr *data[], 1134 struct netlink_ext_ack *extack) 1135 { 1136 if (!data) 1137 return -EINVAL; 1138 1139 return 0; 1140 } 1141 1142 static size_t gtp_get_size(const struct net_device *dev) 1143 { 1144 return nla_total_size(sizeof(__u32)) + /* IFLA_GTP_PDP_HASHSIZE */ 1145 nla_total_size(sizeof(__u32)) + /* IFLA_GTP_ROLE */ 1146 nla_total_size(sizeof(__u8)); /* IFLA_GTP_RESTART_COUNT */ 1147 } 1148 1149 static int gtp_fill_info(struct sk_buff *skb, const struct net_device *dev) 1150 { 1151 struct gtp_dev *gtp = netdev_priv(dev); 1152 1153 if (nla_put_u32(skb, IFLA_GTP_PDP_HASHSIZE, gtp->hash_size)) 1154 goto nla_put_failure; 1155 if (nla_put_u32(skb, IFLA_GTP_ROLE, gtp->role)) 1156 goto nla_put_failure; 1157 if (nla_put_u8(skb, IFLA_GTP_RESTART_COUNT, gtp->restart_count)) 1158 goto nla_put_failure; 1159 1160 return 0; 1161 1162 nla_put_failure: 1163 return -EMSGSIZE; 1164 } 1165 1166 static struct rtnl_link_ops gtp_link_ops __read_mostly = { 1167 .kind = "gtp", 1168 .maxtype = IFLA_GTP_MAX, 1169 .policy = gtp_policy, 1170 .priv_size = sizeof(struct gtp_dev), 1171 .setup = gtp_link_setup, 1172 .validate = gtp_validate, 1173 .newlink = gtp_newlink, 1174 .dellink = gtp_dellink, 1175 .get_size = gtp_get_size, 1176 .fill_info = gtp_fill_info, 1177 }; 1178 1179 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize) 1180 { 1181 int i; 1182 1183 gtp->addr_hash = kmalloc_array(hsize, sizeof(struct hlist_head), 1184 GFP_KERNEL | __GFP_NOWARN); 1185 if (gtp->addr_hash == NULL) 1186 return -ENOMEM; 1187 1188 gtp->tid_hash = kmalloc_array(hsize, sizeof(struct hlist_head), 1189 GFP_KERNEL | __GFP_NOWARN); 1190 if (gtp->tid_hash == NULL) 1191 goto err1; 1192 1193 gtp->hash_size = hsize; 1194 1195 for (i = 0; i < hsize; i++) { 1196 INIT_HLIST_HEAD(>p->addr_hash[i]); 1197 INIT_HLIST_HEAD(>p->tid_hash[i]); 1198 } 1199 return 0; 1200 err1: 1201 kfree(gtp->addr_hash); 1202 return -ENOMEM; 1203 } 1204 1205 static struct sock *gtp_encap_enable_socket(int fd, int type, 1206 struct gtp_dev *gtp) 1207 { 1208 struct udp_tunnel_sock_cfg tuncfg = {NULL}; 1209 struct socket *sock; 1210 struct sock *sk; 1211 int err; 1212 1213 pr_debug("enable gtp on %d, %d\n", fd, type); 1214 1215 sock = sockfd_lookup(fd, &err); 1216 if (!sock) { 1217 pr_debug("gtp socket fd=%d not found\n", fd); 1218 return NULL; 1219 } 1220 1221 sk = sock->sk; 1222 if (sk->sk_protocol != IPPROTO_UDP || 1223 sk->sk_type != SOCK_DGRAM || 1224 (sk->sk_family != AF_INET && sk->sk_family != AF_INET6)) { 1225 pr_debug("socket fd=%d not UDP\n", fd); 1226 sk = ERR_PTR(-EINVAL); 1227 goto out_sock; 1228 } 1229 1230 lock_sock(sk); 1231 if (sk->sk_user_data) { 1232 sk = ERR_PTR(-EBUSY); 1233 goto out_rel_sock; 1234 } 1235 1236 sock_hold(sk); 1237 1238 tuncfg.sk_user_data = gtp; 1239 tuncfg.encap_type = type; 1240 tuncfg.encap_rcv = gtp_encap_recv; 1241 tuncfg.encap_destroy = gtp_encap_destroy; 1242 1243 setup_udp_tunnel_sock(sock_net(sock->sk), sock, &tuncfg); 1244 1245 out_rel_sock: 1246 release_sock(sock->sk); 1247 out_sock: 1248 sockfd_put(sock); 1249 return sk; 1250 } 1251 1252 static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]) 1253 { 1254 struct sock *sk1u = NULL; 1255 struct sock *sk0 = NULL; 1256 1257 if (!data[IFLA_GTP_FD0] && !data[IFLA_GTP_FD1]) 1258 return -EINVAL; 1259 1260 if (data[IFLA_GTP_FD0]) { 1261 u32 fd0 = nla_get_u32(data[IFLA_GTP_FD0]); 1262 1263 sk0 = gtp_encap_enable_socket(fd0, UDP_ENCAP_GTP0, gtp); 1264 if (IS_ERR(sk0)) 1265 return PTR_ERR(sk0); 1266 } 1267 1268 if (data[IFLA_GTP_FD1]) { 1269 u32 fd1 = nla_get_u32(data[IFLA_GTP_FD1]); 1270 1271 sk1u = gtp_encap_enable_socket(fd1, UDP_ENCAP_GTP1U, gtp); 1272 if (IS_ERR(sk1u)) { 1273 gtp_encap_disable_sock(sk0); 1274 return PTR_ERR(sk1u); 1275 } 1276 } 1277 1278 gtp->sk0 = sk0; 1279 gtp->sk1u = sk1u; 1280 1281 return 0; 1282 } 1283 1284 static struct gtp_dev *gtp_find_dev(struct net *src_net, struct nlattr *nla[]) 1285 { 1286 struct gtp_dev *gtp = NULL; 1287 struct net_device *dev; 1288 struct net *net; 1289 1290 /* Examine the link attributes and figure out which network namespace 1291 * we are talking about. 1292 */ 1293 if (nla[GTPA_NET_NS_FD]) 1294 net = get_net_ns_by_fd(nla_get_u32(nla[GTPA_NET_NS_FD])); 1295 else 1296 net = get_net(src_net); 1297 1298 if (IS_ERR(net)) 1299 return NULL; 1300 1301 /* Check if there's an existing gtpX device to configure */ 1302 dev = dev_get_by_index_rcu(net, nla_get_u32(nla[GTPA_LINK])); 1303 if (dev && dev->netdev_ops == >p_netdev_ops) 1304 gtp = netdev_priv(dev); 1305 1306 put_net(net); 1307 return gtp; 1308 } 1309 1310 static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info) 1311 { 1312 pctx->gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]); 1313 pctx->af = AF_INET; 1314 pctx->peer_addr_ip4.s_addr = 1315 nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]); 1316 pctx->ms_addr_ip4.s_addr = 1317 nla_get_be32(info->attrs[GTPA_MS_ADDRESS]); 1318 1319 switch (pctx->gtp_version) { 1320 case GTP_V0: 1321 /* According to TS 09.60, sections 7.5.1 and 7.5.2, the flow 1322 * label needs to be the same for uplink and downlink packets, 1323 * so let's annotate this. 1324 */ 1325 pctx->u.v0.tid = nla_get_u64(info->attrs[GTPA_TID]); 1326 pctx->u.v0.flow = nla_get_u16(info->attrs[GTPA_FLOW]); 1327 break; 1328 case GTP_V1: 1329 pctx->u.v1.i_tei = nla_get_u32(info->attrs[GTPA_I_TEI]); 1330 pctx->u.v1.o_tei = nla_get_u32(info->attrs[GTPA_O_TEI]); 1331 break; 1332 default: 1333 break; 1334 } 1335 } 1336 1337 static struct pdp_ctx *gtp_pdp_add(struct gtp_dev *gtp, struct sock *sk, 1338 struct genl_info *info) 1339 { 1340 struct pdp_ctx *pctx, *pctx_tid = NULL; 1341 struct net_device *dev = gtp->dev; 1342 u32 hash_ms, hash_tid = 0; 1343 unsigned int version; 1344 bool found = false; 1345 __be32 ms_addr; 1346 1347 ms_addr = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]); 1348 hash_ms = ipv4_hashfn(ms_addr) % gtp->hash_size; 1349 version = nla_get_u32(info->attrs[GTPA_VERSION]); 1350 1351 pctx = ipv4_pdp_find(gtp, ms_addr); 1352 if (pctx) 1353 found = true; 1354 if (version == GTP_V0) 1355 pctx_tid = gtp0_pdp_find(gtp, 1356 nla_get_u64(info->attrs[GTPA_TID])); 1357 else if (version == GTP_V1) 1358 pctx_tid = gtp1_pdp_find(gtp, 1359 nla_get_u32(info->attrs[GTPA_I_TEI])); 1360 if (pctx_tid) 1361 found = true; 1362 1363 if (found) { 1364 if (info->nlhdr->nlmsg_flags & NLM_F_EXCL) 1365 return ERR_PTR(-EEXIST); 1366 if (info->nlhdr->nlmsg_flags & NLM_F_REPLACE) 1367 return ERR_PTR(-EOPNOTSUPP); 1368 1369 if (pctx && pctx_tid) 1370 return ERR_PTR(-EEXIST); 1371 if (!pctx) 1372 pctx = pctx_tid; 1373 1374 ipv4_pdp_fill(pctx, info); 1375 1376 if (pctx->gtp_version == GTP_V0) 1377 netdev_dbg(dev, "GTPv0-U: update tunnel id = %llx (pdp %p)\n", 1378 pctx->u.v0.tid, pctx); 1379 else if (pctx->gtp_version == GTP_V1) 1380 netdev_dbg(dev, "GTPv1-U: update tunnel id = %x/%x (pdp %p)\n", 1381 pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx); 1382 1383 return pctx; 1384 1385 } 1386 1387 pctx = kmalloc(sizeof(*pctx), GFP_ATOMIC); 1388 if (pctx == NULL) 1389 return ERR_PTR(-ENOMEM); 1390 1391 sock_hold(sk); 1392 pctx->sk = sk; 1393 pctx->dev = gtp->dev; 1394 ipv4_pdp_fill(pctx, info); 1395 atomic_set(&pctx->tx_seq, 0); 1396 1397 switch (pctx->gtp_version) { 1398 case GTP_V0: 1399 /* TS 09.60: "The flow label identifies unambiguously a GTP 1400 * flow.". We use the tid for this instead, I cannot find a 1401 * situation in which this doesn't unambiguosly identify the 1402 * PDP context. 1403 */ 1404 hash_tid = gtp0_hashfn(pctx->u.v0.tid) % gtp->hash_size; 1405 break; 1406 case GTP_V1: 1407 hash_tid = gtp1u_hashfn(pctx->u.v1.i_tei) % gtp->hash_size; 1408 break; 1409 } 1410 1411 hlist_add_head_rcu(&pctx->hlist_addr, >p->addr_hash[hash_ms]); 1412 hlist_add_head_rcu(&pctx->hlist_tid, >p->tid_hash[hash_tid]); 1413 1414 switch (pctx->gtp_version) { 1415 case GTP_V0: 1416 netdev_dbg(dev, "GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n", 1417 pctx->u.v0.tid, &pctx->peer_addr_ip4, 1418 &pctx->ms_addr_ip4, pctx); 1419 break; 1420 case GTP_V1: 1421 netdev_dbg(dev, "GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n", 1422 pctx->u.v1.i_tei, pctx->u.v1.o_tei, 1423 &pctx->peer_addr_ip4, &pctx->ms_addr_ip4, pctx); 1424 break; 1425 } 1426 1427 return pctx; 1428 } 1429 1430 static void pdp_context_free(struct rcu_head *head) 1431 { 1432 struct pdp_ctx *pctx = container_of(head, struct pdp_ctx, rcu_head); 1433 1434 sock_put(pctx->sk); 1435 kfree(pctx); 1436 } 1437 1438 static void pdp_context_delete(struct pdp_ctx *pctx) 1439 { 1440 hlist_del_rcu(&pctx->hlist_tid); 1441 hlist_del_rcu(&pctx->hlist_addr); 1442 call_rcu(&pctx->rcu_head, pdp_context_free); 1443 } 1444 1445 static int gtp_tunnel_notify(struct pdp_ctx *pctx, u8 cmd, gfp_t allocation); 1446 1447 static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info) 1448 { 1449 unsigned int version; 1450 struct pdp_ctx *pctx; 1451 struct gtp_dev *gtp; 1452 struct sock *sk; 1453 int err; 1454 1455 if (!info->attrs[GTPA_VERSION] || 1456 !info->attrs[GTPA_LINK] || 1457 !info->attrs[GTPA_PEER_ADDRESS] || 1458 !info->attrs[GTPA_MS_ADDRESS]) 1459 return -EINVAL; 1460 1461 version = nla_get_u32(info->attrs[GTPA_VERSION]); 1462 1463 switch (version) { 1464 case GTP_V0: 1465 if (!info->attrs[GTPA_TID] || 1466 !info->attrs[GTPA_FLOW]) 1467 return -EINVAL; 1468 break; 1469 case GTP_V1: 1470 if (!info->attrs[GTPA_I_TEI] || 1471 !info->attrs[GTPA_O_TEI]) 1472 return -EINVAL; 1473 break; 1474 1475 default: 1476 return -EINVAL; 1477 } 1478 1479 rtnl_lock(); 1480 1481 gtp = gtp_find_dev(sock_net(skb->sk), info->attrs); 1482 if (!gtp) { 1483 err = -ENODEV; 1484 goto out_unlock; 1485 } 1486 1487 if (version == GTP_V0) 1488 sk = gtp->sk0; 1489 else if (version == GTP_V1) 1490 sk = gtp->sk1u; 1491 else 1492 sk = NULL; 1493 1494 if (!sk) { 1495 err = -ENODEV; 1496 goto out_unlock; 1497 } 1498 1499 pctx = gtp_pdp_add(gtp, sk, info); 1500 if (IS_ERR(pctx)) { 1501 err = PTR_ERR(pctx); 1502 } else { 1503 gtp_tunnel_notify(pctx, GTP_CMD_NEWPDP, GFP_KERNEL); 1504 err = 0; 1505 } 1506 1507 out_unlock: 1508 rtnl_unlock(); 1509 return err; 1510 } 1511 1512 static struct pdp_ctx *gtp_find_pdp_by_link(struct net *net, 1513 struct nlattr *nla[]) 1514 { 1515 struct gtp_dev *gtp; 1516 1517 gtp = gtp_find_dev(net, nla); 1518 if (!gtp) 1519 return ERR_PTR(-ENODEV); 1520 1521 if (nla[GTPA_MS_ADDRESS]) { 1522 __be32 ip = nla_get_be32(nla[GTPA_MS_ADDRESS]); 1523 1524 return ipv4_pdp_find(gtp, ip); 1525 } else if (nla[GTPA_VERSION]) { 1526 u32 gtp_version = nla_get_u32(nla[GTPA_VERSION]); 1527 1528 if (gtp_version == GTP_V0 && nla[GTPA_TID]) 1529 return gtp0_pdp_find(gtp, nla_get_u64(nla[GTPA_TID])); 1530 else if (gtp_version == GTP_V1 && nla[GTPA_I_TEI]) 1531 return gtp1_pdp_find(gtp, nla_get_u32(nla[GTPA_I_TEI])); 1532 } 1533 1534 return ERR_PTR(-EINVAL); 1535 } 1536 1537 static struct pdp_ctx *gtp_find_pdp(struct net *net, struct nlattr *nla[]) 1538 { 1539 struct pdp_ctx *pctx; 1540 1541 if (nla[GTPA_LINK]) 1542 pctx = gtp_find_pdp_by_link(net, nla); 1543 else 1544 pctx = ERR_PTR(-EINVAL); 1545 1546 if (!pctx) 1547 pctx = ERR_PTR(-ENOENT); 1548 1549 return pctx; 1550 } 1551 1552 static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info) 1553 { 1554 struct pdp_ctx *pctx; 1555 int err = 0; 1556 1557 if (!info->attrs[GTPA_VERSION]) 1558 return -EINVAL; 1559 1560 rcu_read_lock(); 1561 1562 pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs); 1563 if (IS_ERR(pctx)) { 1564 err = PTR_ERR(pctx); 1565 goto out_unlock; 1566 } 1567 1568 if (pctx->gtp_version == GTP_V0) 1569 netdev_dbg(pctx->dev, "GTPv0-U: deleting tunnel id = %llx (pdp %p)\n", 1570 pctx->u.v0.tid, pctx); 1571 else if (pctx->gtp_version == GTP_V1) 1572 netdev_dbg(pctx->dev, "GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n", 1573 pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx); 1574 1575 gtp_tunnel_notify(pctx, GTP_CMD_DELPDP, GFP_ATOMIC); 1576 pdp_context_delete(pctx); 1577 1578 out_unlock: 1579 rcu_read_unlock(); 1580 return err; 1581 } 1582 1583 static int gtp_genl_fill_info(struct sk_buff *skb, u32 snd_portid, u32 snd_seq, 1584 int flags, u32 type, struct pdp_ctx *pctx) 1585 { 1586 void *genlh; 1587 1588 genlh = genlmsg_put(skb, snd_portid, snd_seq, >p_genl_family, flags, 1589 type); 1590 if (genlh == NULL) 1591 goto nlmsg_failure; 1592 1593 if (nla_put_u32(skb, GTPA_VERSION, pctx->gtp_version) || 1594 nla_put_u32(skb, GTPA_LINK, pctx->dev->ifindex) || 1595 nla_put_be32(skb, GTPA_PEER_ADDRESS, pctx->peer_addr_ip4.s_addr) || 1596 nla_put_be32(skb, GTPA_MS_ADDRESS, pctx->ms_addr_ip4.s_addr)) 1597 goto nla_put_failure; 1598 1599 switch (pctx->gtp_version) { 1600 case GTP_V0: 1601 if (nla_put_u64_64bit(skb, GTPA_TID, pctx->u.v0.tid, GTPA_PAD) || 1602 nla_put_u16(skb, GTPA_FLOW, pctx->u.v0.flow)) 1603 goto nla_put_failure; 1604 break; 1605 case GTP_V1: 1606 if (nla_put_u32(skb, GTPA_I_TEI, pctx->u.v1.i_tei) || 1607 nla_put_u32(skb, GTPA_O_TEI, pctx->u.v1.o_tei)) 1608 goto nla_put_failure; 1609 break; 1610 } 1611 genlmsg_end(skb, genlh); 1612 return 0; 1613 1614 nlmsg_failure: 1615 nla_put_failure: 1616 genlmsg_cancel(skb, genlh); 1617 return -EMSGSIZE; 1618 } 1619 1620 static int gtp_tunnel_notify(struct pdp_ctx *pctx, u8 cmd, gfp_t allocation) 1621 { 1622 struct sk_buff *msg; 1623 int ret; 1624 1625 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, allocation); 1626 if (!msg) 1627 return -ENOMEM; 1628 1629 ret = gtp_genl_fill_info(msg, 0, 0, 0, cmd, pctx); 1630 if (ret < 0) { 1631 nlmsg_free(msg); 1632 return ret; 1633 } 1634 1635 ret = genlmsg_multicast_netns(>p_genl_family, dev_net(pctx->dev), msg, 1636 0, GTP_GENL_MCGRP, GFP_ATOMIC); 1637 return ret; 1638 } 1639 1640 static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info) 1641 { 1642 struct pdp_ctx *pctx = NULL; 1643 struct sk_buff *skb2; 1644 int err; 1645 1646 if (!info->attrs[GTPA_VERSION]) 1647 return -EINVAL; 1648 1649 rcu_read_lock(); 1650 1651 pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs); 1652 if (IS_ERR(pctx)) { 1653 err = PTR_ERR(pctx); 1654 goto err_unlock; 1655 } 1656 1657 skb2 = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC); 1658 if (skb2 == NULL) { 1659 err = -ENOMEM; 1660 goto err_unlock; 1661 } 1662 1663 err = gtp_genl_fill_info(skb2, NETLINK_CB(skb).portid, info->snd_seq, 1664 0, info->nlhdr->nlmsg_type, pctx); 1665 if (err < 0) 1666 goto err_unlock_free; 1667 1668 rcu_read_unlock(); 1669 return genlmsg_unicast(genl_info_net(info), skb2, info->snd_portid); 1670 1671 err_unlock_free: 1672 kfree_skb(skb2); 1673 err_unlock: 1674 rcu_read_unlock(); 1675 return err; 1676 } 1677 1678 static int gtp_genl_dump_pdp(struct sk_buff *skb, 1679 struct netlink_callback *cb) 1680 { 1681 struct gtp_dev *last_gtp = (struct gtp_dev *)cb->args[2], *gtp; 1682 int i, j, bucket = cb->args[0], skip = cb->args[1]; 1683 struct net *net = sock_net(skb->sk); 1684 struct pdp_ctx *pctx; 1685 struct gtp_net *gn; 1686 1687 gn = net_generic(net, gtp_net_id); 1688 1689 if (cb->args[4]) 1690 return 0; 1691 1692 rcu_read_lock(); 1693 list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) { 1694 if (last_gtp && last_gtp != gtp) 1695 continue; 1696 else 1697 last_gtp = NULL; 1698 1699 for (i = bucket; i < gtp->hash_size; i++) { 1700 j = 0; 1701 hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], 1702 hlist_tid) { 1703 if (j >= skip && 1704 gtp_genl_fill_info(skb, 1705 NETLINK_CB(cb->skb).portid, 1706 cb->nlh->nlmsg_seq, 1707 NLM_F_MULTI, 1708 cb->nlh->nlmsg_type, pctx)) { 1709 cb->args[0] = i; 1710 cb->args[1] = j; 1711 cb->args[2] = (unsigned long)gtp; 1712 goto out; 1713 } 1714 j++; 1715 } 1716 skip = 0; 1717 } 1718 bucket = 0; 1719 } 1720 cb->args[4] = 1; 1721 out: 1722 rcu_read_unlock(); 1723 return skb->len; 1724 } 1725 1726 static int gtp_genl_send_echo_req(struct sk_buff *skb, struct genl_info *info) 1727 { 1728 struct sk_buff *skb_to_send; 1729 __be32 src_ip, dst_ip; 1730 unsigned int version; 1731 struct gtp_dev *gtp; 1732 struct flowi4 fl4; 1733 struct rtable *rt; 1734 struct sock *sk; 1735 __be16 port; 1736 int len; 1737 1738 if (!info->attrs[GTPA_VERSION] || 1739 !info->attrs[GTPA_LINK] || 1740 !info->attrs[GTPA_PEER_ADDRESS] || 1741 !info->attrs[GTPA_MS_ADDRESS]) 1742 return -EINVAL; 1743 1744 version = nla_get_u32(info->attrs[GTPA_VERSION]); 1745 dst_ip = nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]); 1746 src_ip = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]); 1747 1748 gtp = gtp_find_dev(sock_net(skb->sk), info->attrs); 1749 if (!gtp) 1750 return -ENODEV; 1751 1752 if (!gtp->sk_created) 1753 return -EOPNOTSUPP; 1754 if (!(gtp->dev->flags & IFF_UP)) 1755 return -ENETDOWN; 1756 1757 if (version == GTP_V0) { 1758 struct gtp0_header *gtp0_h; 1759 1760 len = LL_RESERVED_SPACE(gtp->dev) + sizeof(struct gtp0_header) + 1761 sizeof(struct iphdr) + sizeof(struct udphdr); 1762 1763 skb_to_send = netdev_alloc_skb_ip_align(gtp->dev, len); 1764 if (!skb_to_send) 1765 return -ENOMEM; 1766 1767 sk = gtp->sk0; 1768 port = htons(GTP0_PORT); 1769 1770 gtp0_h = skb_push(skb_to_send, sizeof(struct gtp0_header)); 1771 memset(gtp0_h, 0, sizeof(struct gtp0_header)); 1772 gtp0_build_echo_msg(gtp0_h, GTP_ECHO_REQ); 1773 } else if (version == GTP_V1) { 1774 struct gtp1_header_long *gtp1u_h; 1775 1776 len = LL_RESERVED_SPACE(gtp->dev) + 1777 sizeof(struct gtp1_header_long) + 1778 sizeof(struct iphdr) + sizeof(struct udphdr); 1779 1780 skb_to_send = netdev_alloc_skb_ip_align(gtp->dev, len); 1781 if (!skb_to_send) 1782 return -ENOMEM; 1783 1784 sk = gtp->sk1u; 1785 port = htons(GTP1U_PORT); 1786 1787 gtp1u_h = skb_push(skb_to_send, 1788 sizeof(struct gtp1_header_long)); 1789 memset(gtp1u_h, 0, sizeof(struct gtp1_header_long)); 1790 gtp1u_build_echo_msg(gtp1u_h, GTP_ECHO_REQ); 1791 } else { 1792 return -ENODEV; 1793 } 1794 1795 rt = ip4_route_output_gtp(&fl4, sk, dst_ip, src_ip); 1796 if (IS_ERR(rt)) { 1797 netdev_dbg(gtp->dev, "no route for echo request to %pI4\n", 1798 &dst_ip); 1799 kfree_skb(skb_to_send); 1800 return -ENODEV; 1801 } 1802 1803 udp_tunnel_xmit_skb(rt, sk, skb_to_send, 1804 fl4.saddr, fl4.daddr, 1805 fl4.flowi4_tos, 1806 ip4_dst_hoplimit(&rt->dst), 1807 0, 1808 port, port, 1809 !net_eq(sock_net(sk), 1810 dev_net(gtp->dev)), 1811 false); 1812 return 0; 1813 } 1814 1815 static const struct nla_policy gtp_genl_policy[GTPA_MAX + 1] = { 1816 [GTPA_LINK] = { .type = NLA_U32, }, 1817 [GTPA_VERSION] = { .type = NLA_U32, }, 1818 [GTPA_TID] = { .type = NLA_U64, }, 1819 [GTPA_PEER_ADDRESS] = { .type = NLA_U32, }, 1820 [GTPA_MS_ADDRESS] = { .type = NLA_U32, }, 1821 [GTPA_FLOW] = { .type = NLA_U16, }, 1822 [GTPA_NET_NS_FD] = { .type = NLA_U32, }, 1823 [GTPA_I_TEI] = { .type = NLA_U32, }, 1824 [GTPA_O_TEI] = { .type = NLA_U32, }, 1825 }; 1826 1827 static const struct genl_small_ops gtp_genl_ops[] = { 1828 { 1829 .cmd = GTP_CMD_NEWPDP, 1830 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, 1831 .doit = gtp_genl_new_pdp, 1832 .flags = GENL_ADMIN_PERM, 1833 }, 1834 { 1835 .cmd = GTP_CMD_DELPDP, 1836 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, 1837 .doit = gtp_genl_del_pdp, 1838 .flags = GENL_ADMIN_PERM, 1839 }, 1840 { 1841 .cmd = GTP_CMD_GETPDP, 1842 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, 1843 .doit = gtp_genl_get_pdp, 1844 .dumpit = gtp_genl_dump_pdp, 1845 .flags = GENL_ADMIN_PERM, 1846 }, 1847 { 1848 .cmd = GTP_CMD_ECHOREQ, 1849 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, 1850 .doit = gtp_genl_send_echo_req, 1851 .flags = GENL_ADMIN_PERM, 1852 }, 1853 }; 1854 1855 static struct genl_family gtp_genl_family __ro_after_init = { 1856 .name = "gtp", 1857 .version = 0, 1858 .hdrsize = 0, 1859 .maxattr = GTPA_MAX, 1860 .policy = gtp_genl_policy, 1861 .netnsok = true, 1862 .module = THIS_MODULE, 1863 .small_ops = gtp_genl_ops, 1864 .n_small_ops = ARRAY_SIZE(gtp_genl_ops), 1865 .resv_start_op = GTP_CMD_ECHOREQ + 1, 1866 .mcgrps = gtp_genl_mcgrps, 1867 .n_mcgrps = ARRAY_SIZE(gtp_genl_mcgrps), 1868 }; 1869 1870 static int __net_init gtp_net_init(struct net *net) 1871 { 1872 struct gtp_net *gn = net_generic(net, gtp_net_id); 1873 1874 INIT_LIST_HEAD(&gn->gtp_dev_list); 1875 return 0; 1876 } 1877 1878 static void __net_exit gtp_net_exit(struct net *net) 1879 { 1880 struct gtp_net *gn = net_generic(net, gtp_net_id); 1881 struct gtp_dev *gtp; 1882 LIST_HEAD(list); 1883 1884 rtnl_lock(); 1885 list_for_each_entry(gtp, &gn->gtp_dev_list, list) 1886 gtp_dellink(gtp->dev, &list); 1887 1888 unregister_netdevice_many(&list); 1889 rtnl_unlock(); 1890 } 1891 1892 static struct pernet_operations gtp_net_ops = { 1893 .init = gtp_net_init, 1894 .exit = gtp_net_exit, 1895 .id = >p_net_id, 1896 .size = sizeof(struct gtp_net), 1897 }; 1898 1899 static int __init gtp_init(void) 1900 { 1901 int err; 1902 1903 get_random_bytes(>p_h_initval, sizeof(gtp_h_initval)); 1904 1905 err = rtnl_link_register(>p_link_ops); 1906 if (err < 0) 1907 goto error_out; 1908 1909 err = genl_register_family(>p_genl_family); 1910 if (err < 0) 1911 goto unreg_rtnl_link; 1912 1913 err = register_pernet_subsys(>p_net_ops); 1914 if (err < 0) 1915 goto unreg_genl_family; 1916 1917 pr_info("GTP module loaded (pdp ctx size %zd bytes)\n", 1918 sizeof(struct pdp_ctx)); 1919 return 0; 1920 1921 unreg_genl_family: 1922 genl_unregister_family(>p_genl_family); 1923 unreg_rtnl_link: 1924 rtnl_link_unregister(>p_link_ops); 1925 error_out: 1926 pr_err("error loading GTP module loaded\n"); 1927 return err; 1928 } 1929 late_initcall(gtp_init); 1930 1931 static void __exit gtp_fini(void) 1932 { 1933 genl_unregister_family(>p_genl_family); 1934 rtnl_link_unregister(>p_link_ops); 1935 unregister_pernet_subsys(>p_net_ops); 1936 1937 pr_info("GTP module unloaded\n"); 1938 } 1939 module_exit(gtp_fini); 1940 1941 MODULE_LICENSE("GPL"); 1942 MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>"); 1943 MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic"); 1944 MODULE_ALIAS_RTNL_LINK("gtp"); 1945 MODULE_ALIAS_GENL_FAMILY("gtp"); 1946