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 WRITE_ONCE(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 (READ_ONCE(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 void gtp_dev_uninit(struct net_device *dev) 715 { 716 struct gtp_dev *gtp = netdev_priv(dev); 717 718 gtp_encap_disable(gtp); 719 } 720 721 static inline void gtp0_push_header(struct sk_buff *skb, struct pdp_ctx *pctx) 722 { 723 int payload_len = skb->len; 724 struct gtp0_header *gtp0; 725 726 gtp0 = skb_push(skb, sizeof(*gtp0)); 727 728 gtp0->flags = 0x1e; /* v0, GTP-non-prime. */ 729 gtp0->type = GTP_TPDU; 730 gtp0->length = htons(payload_len); 731 gtp0->seq = htons((atomic_inc_return(&pctx->tx_seq) - 1) % 0xffff); 732 gtp0->flow = htons(pctx->u.v0.flow); 733 gtp0->number = 0xff; 734 gtp0->spare[0] = gtp0->spare[1] = gtp0->spare[2] = 0xff; 735 gtp0->tid = cpu_to_be64(pctx->u.v0.tid); 736 } 737 738 static inline void gtp1_push_header(struct sk_buff *skb, struct pdp_ctx *pctx) 739 { 740 int payload_len = skb->len; 741 struct gtp1_header *gtp1; 742 743 gtp1 = skb_push(skb, sizeof(*gtp1)); 744 745 /* Bits 8 7 6 5 4 3 2 1 746 * +--+--+--+--+--+--+--+--+ 747 * |version |PT| 0| E| S|PN| 748 * +--+--+--+--+--+--+--+--+ 749 * 0 0 1 1 1 0 0 0 750 */ 751 gtp1->flags = 0x30; /* v1, GTP-non-prime. */ 752 gtp1->type = GTP_TPDU; 753 gtp1->length = htons(payload_len); 754 gtp1->tid = htonl(pctx->u.v1.o_tei); 755 756 /* TODO: Support for extension header, sequence number and N-PDU. 757 * Update the length field if any of them is available. 758 */ 759 } 760 761 struct gtp_pktinfo { 762 struct sock *sk; 763 struct iphdr *iph; 764 struct flowi4 fl4; 765 struct rtable *rt; 766 struct pdp_ctx *pctx; 767 struct net_device *dev; 768 __be16 gtph_port; 769 }; 770 771 static void gtp_push_header(struct sk_buff *skb, struct gtp_pktinfo *pktinfo) 772 { 773 switch (pktinfo->pctx->gtp_version) { 774 case GTP_V0: 775 pktinfo->gtph_port = htons(GTP0_PORT); 776 gtp0_push_header(skb, pktinfo->pctx); 777 break; 778 case GTP_V1: 779 pktinfo->gtph_port = htons(GTP1U_PORT); 780 gtp1_push_header(skb, pktinfo->pctx); 781 break; 782 } 783 } 784 785 static inline void gtp_set_pktinfo_ipv4(struct gtp_pktinfo *pktinfo, 786 struct sock *sk, struct iphdr *iph, 787 struct pdp_ctx *pctx, struct rtable *rt, 788 struct flowi4 *fl4, 789 struct net_device *dev) 790 { 791 pktinfo->sk = sk; 792 pktinfo->iph = iph; 793 pktinfo->pctx = pctx; 794 pktinfo->rt = rt; 795 pktinfo->fl4 = *fl4; 796 pktinfo->dev = dev; 797 } 798 799 static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev, 800 struct gtp_pktinfo *pktinfo) 801 { 802 struct gtp_dev *gtp = netdev_priv(dev); 803 struct pdp_ctx *pctx; 804 struct rtable *rt; 805 struct flowi4 fl4; 806 struct iphdr *iph; 807 __be16 df; 808 int mtu; 809 810 /* Read the IP destination address and resolve the PDP context. 811 * Prepend PDP header with TEI/TID from PDP ctx. 812 */ 813 iph = ip_hdr(skb); 814 if (gtp->role == GTP_ROLE_SGSN) 815 pctx = ipv4_pdp_find(gtp, iph->saddr); 816 else 817 pctx = ipv4_pdp_find(gtp, iph->daddr); 818 819 if (!pctx) { 820 netdev_dbg(dev, "no PDP ctx found for %pI4, skip\n", 821 &iph->daddr); 822 return -ENOENT; 823 } 824 netdev_dbg(dev, "found PDP context %p\n", pctx); 825 826 rt = ip4_route_output_gtp(&fl4, pctx->sk, pctx->peer_addr_ip4.s_addr, 827 inet_sk(pctx->sk)->inet_saddr); 828 if (IS_ERR(rt)) { 829 netdev_dbg(dev, "no route to SSGN %pI4\n", 830 &pctx->peer_addr_ip4.s_addr); 831 dev->stats.tx_carrier_errors++; 832 goto err; 833 } 834 835 if (rt->dst.dev == dev) { 836 netdev_dbg(dev, "circular route to SSGN %pI4\n", 837 &pctx->peer_addr_ip4.s_addr); 838 dev->stats.collisions++; 839 goto err_rt; 840 } 841 842 /* This is similar to tnl_update_pmtu(). */ 843 df = iph->frag_off; 844 if (df) { 845 mtu = dst_mtu(&rt->dst) - dev->hard_header_len - 846 sizeof(struct iphdr) - sizeof(struct udphdr); 847 switch (pctx->gtp_version) { 848 case GTP_V0: 849 mtu -= sizeof(struct gtp0_header); 850 break; 851 case GTP_V1: 852 mtu -= sizeof(struct gtp1_header); 853 break; 854 } 855 } else { 856 mtu = dst_mtu(&rt->dst); 857 } 858 859 skb_dst_update_pmtu_no_confirm(skb, mtu); 860 861 if (iph->frag_off & htons(IP_DF) && 862 ((!skb_is_gso(skb) && skb->len > mtu) || 863 (skb_is_gso(skb) && !skb_gso_validate_network_len(skb, mtu)))) { 864 netdev_dbg(dev, "packet too big, fragmentation needed\n"); 865 icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, 866 htonl(mtu)); 867 goto err_rt; 868 } 869 870 gtp_set_pktinfo_ipv4(pktinfo, pctx->sk, iph, pctx, rt, &fl4, dev); 871 gtp_push_header(skb, pktinfo); 872 873 return 0; 874 err_rt: 875 ip_rt_put(rt); 876 err: 877 return -EBADMSG; 878 } 879 880 static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev) 881 { 882 unsigned int proto = ntohs(skb->protocol); 883 struct gtp_pktinfo pktinfo; 884 int err; 885 886 /* Ensure there is sufficient headroom. */ 887 if (skb_cow_head(skb, dev->needed_headroom)) 888 goto tx_err; 889 890 skb_reset_inner_headers(skb); 891 892 /* PDP context lookups in gtp_build_skb_*() need rcu read-side lock. */ 893 rcu_read_lock(); 894 switch (proto) { 895 case ETH_P_IP: 896 err = gtp_build_skb_ip4(skb, dev, &pktinfo); 897 break; 898 default: 899 err = -EOPNOTSUPP; 900 break; 901 } 902 rcu_read_unlock(); 903 904 if (err < 0) 905 goto tx_err; 906 907 switch (proto) { 908 case ETH_P_IP: 909 netdev_dbg(pktinfo.dev, "gtp -> IP src: %pI4 dst: %pI4\n", 910 &pktinfo.iph->saddr, &pktinfo.iph->daddr); 911 udp_tunnel_xmit_skb(pktinfo.rt, pktinfo.sk, skb, 912 pktinfo.fl4.saddr, pktinfo.fl4.daddr, 913 pktinfo.iph->tos, 914 ip4_dst_hoplimit(&pktinfo.rt->dst), 915 0, 916 pktinfo.gtph_port, pktinfo.gtph_port, 917 !net_eq(sock_net(pktinfo.pctx->sk), 918 dev_net(dev)), 919 false); 920 break; 921 } 922 923 return NETDEV_TX_OK; 924 tx_err: 925 dev->stats.tx_errors++; 926 dev_kfree_skb(skb); 927 return NETDEV_TX_OK; 928 } 929 930 static const struct net_device_ops gtp_netdev_ops = { 931 .ndo_uninit = gtp_dev_uninit, 932 .ndo_start_xmit = gtp_dev_xmit, 933 }; 934 935 static const struct device_type gtp_type = { 936 .name = "gtp", 937 }; 938 939 static void gtp_link_setup(struct net_device *dev) 940 { 941 unsigned int max_gtp_header_len = sizeof(struct iphdr) + 942 sizeof(struct udphdr) + 943 sizeof(struct gtp0_header); 944 struct gtp_dev *gtp = netdev_priv(dev); 945 946 dev->netdev_ops = >p_netdev_ops; 947 dev->needs_free_netdev = true; 948 SET_NETDEV_DEVTYPE(dev, >p_type); 949 950 dev->hard_header_len = 0; 951 dev->addr_len = 0; 952 dev->mtu = ETH_DATA_LEN - max_gtp_header_len; 953 954 /* Zero header length. */ 955 dev->type = ARPHRD_NONE; 956 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 957 958 dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS; 959 dev->priv_flags |= IFF_NO_QUEUE; 960 dev->features |= NETIF_F_LLTX; 961 netif_keep_dst(dev); 962 963 dev->needed_headroom = LL_MAX_HEADER + max_gtp_header_len; 964 gtp->dev = dev; 965 } 966 967 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize); 968 static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]); 969 970 static void gtp_destructor(struct net_device *dev) 971 { 972 struct gtp_dev *gtp = netdev_priv(dev); 973 974 kfree(gtp->addr_hash); 975 kfree(gtp->tid_hash); 976 } 977 978 static struct sock *gtp_create_sock(int type, struct gtp_dev *gtp) 979 { 980 struct udp_tunnel_sock_cfg tuncfg = {}; 981 struct udp_port_cfg udp_conf = { 982 .local_ip.s_addr = htonl(INADDR_ANY), 983 .family = AF_INET, 984 }; 985 struct net *net = gtp->net; 986 struct socket *sock; 987 int err; 988 989 if (type == UDP_ENCAP_GTP0) 990 udp_conf.local_udp_port = htons(GTP0_PORT); 991 else if (type == UDP_ENCAP_GTP1U) 992 udp_conf.local_udp_port = htons(GTP1U_PORT); 993 else 994 return ERR_PTR(-EINVAL); 995 996 err = udp_sock_create(net, &udp_conf, &sock); 997 if (err) 998 return ERR_PTR(err); 999 1000 tuncfg.sk_user_data = gtp; 1001 tuncfg.encap_type = type; 1002 tuncfg.encap_rcv = gtp_encap_recv; 1003 tuncfg.encap_destroy = NULL; 1004 1005 setup_udp_tunnel_sock(net, sock, &tuncfg); 1006 1007 return sock->sk; 1008 } 1009 1010 static int gtp_create_sockets(struct gtp_dev *gtp, struct nlattr *data[]) 1011 { 1012 struct sock *sk1u = NULL; 1013 struct sock *sk0 = NULL; 1014 1015 sk0 = gtp_create_sock(UDP_ENCAP_GTP0, gtp); 1016 if (IS_ERR(sk0)) 1017 return PTR_ERR(sk0); 1018 1019 sk1u = gtp_create_sock(UDP_ENCAP_GTP1U, gtp); 1020 if (IS_ERR(sk1u)) { 1021 udp_tunnel_sock_release(sk0->sk_socket); 1022 return PTR_ERR(sk1u); 1023 } 1024 1025 gtp->sk_created = true; 1026 gtp->sk0 = sk0; 1027 gtp->sk1u = sk1u; 1028 1029 return 0; 1030 } 1031 1032 static int gtp_newlink(struct net *src_net, struct net_device *dev, 1033 struct nlattr *tb[], struct nlattr *data[], 1034 struct netlink_ext_ack *extack) 1035 { 1036 unsigned int role = GTP_ROLE_GGSN; 1037 struct gtp_dev *gtp; 1038 struct gtp_net *gn; 1039 int hashsize, err; 1040 1041 gtp = netdev_priv(dev); 1042 1043 if (!data[IFLA_GTP_PDP_HASHSIZE]) { 1044 hashsize = 1024; 1045 } else { 1046 hashsize = nla_get_u32(data[IFLA_GTP_PDP_HASHSIZE]); 1047 if (!hashsize) 1048 hashsize = 1024; 1049 } 1050 1051 if (data[IFLA_GTP_ROLE]) { 1052 role = nla_get_u32(data[IFLA_GTP_ROLE]); 1053 if (role > GTP_ROLE_SGSN) 1054 return -EINVAL; 1055 } 1056 gtp->role = role; 1057 1058 if (!data[IFLA_GTP_RESTART_COUNT]) 1059 gtp->restart_count = 0; 1060 else 1061 gtp->restart_count = nla_get_u8(data[IFLA_GTP_RESTART_COUNT]); 1062 1063 gtp->net = src_net; 1064 1065 err = gtp_hashtable_new(gtp, hashsize); 1066 if (err < 0) 1067 return err; 1068 1069 if (data[IFLA_GTP_CREATE_SOCKETS]) 1070 err = gtp_create_sockets(gtp, data); 1071 else 1072 err = gtp_encap_enable(gtp, data); 1073 if (err < 0) 1074 goto out_hashtable; 1075 1076 err = register_netdevice(dev); 1077 if (err < 0) { 1078 netdev_dbg(dev, "failed to register new netdev %d\n", err); 1079 goto out_encap; 1080 } 1081 1082 gn = net_generic(dev_net(dev), gtp_net_id); 1083 list_add_rcu(>p->list, &gn->gtp_dev_list); 1084 dev->priv_destructor = gtp_destructor; 1085 1086 netdev_dbg(dev, "registered new GTP interface\n"); 1087 1088 return 0; 1089 1090 out_encap: 1091 gtp_encap_disable(gtp); 1092 out_hashtable: 1093 kfree(gtp->addr_hash); 1094 kfree(gtp->tid_hash); 1095 return err; 1096 } 1097 1098 static void gtp_dellink(struct net_device *dev, struct list_head *head) 1099 { 1100 struct gtp_dev *gtp = netdev_priv(dev); 1101 struct pdp_ctx *pctx; 1102 int i; 1103 1104 for (i = 0; i < gtp->hash_size; i++) 1105 hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], hlist_tid) 1106 pdp_context_delete(pctx); 1107 1108 list_del_rcu(>p->list); 1109 unregister_netdevice_queue(dev, head); 1110 } 1111 1112 static const struct nla_policy gtp_policy[IFLA_GTP_MAX + 1] = { 1113 [IFLA_GTP_FD0] = { .type = NLA_U32 }, 1114 [IFLA_GTP_FD1] = { .type = NLA_U32 }, 1115 [IFLA_GTP_PDP_HASHSIZE] = { .type = NLA_U32 }, 1116 [IFLA_GTP_ROLE] = { .type = NLA_U32 }, 1117 [IFLA_GTP_CREATE_SOCKETS] = { .type = NLA_U8 }, 1118 [IFLA_GTP_RESTART_COUNT] = { .type = NLA_U8 }, 1119 }; 1120 1121 static int gtp_validate(struct nlattr *tb[], struct nlattr *data[], 1122 struct netlink_ext_ack *extack) 1123 { 1124 if (!data) 1125 return -EINVAL; 1126 1127 return 0; 1128 } 1129 1130 static size_t gtp_get_size(const struct net_device *dev) 1131 { 1132 return nla_total_size(sizeof(__u32)) + /* IFLA_GTP_PDP_HASHSIZE */ 1133 nla_total_size(sizeof(__u32)) + /* IFLA_GTP_ROLE */ 1134 nla_total_size(sizeof(__u8)); /* IFLA_GTP_RESTART_COUNT */ 1135 } 1136 1137 static int gtp_fill_info(struct sk_buff *skb, const struct net_device *dev) 1138 { 1139 struct gtp_dev *gtp = netdev_priv(dev); 1140 1141 if (nla_put_u32(skb, IFLA_GTP_PDP_HASHSIZE, gtp->hash_size)) 1142 goto nla_put_failure; 1143 if (nla_put_u32(skb, IFLA_GTP_ROLE, gtp->role)) 1144 goto nla_put_failure; 1145 if (nla_put_u8(skb, IFLA_GTP_RESTART_COUNT, gtp->restart_count)) 1146 goto nla_put_failure; 1147 1148 return 0; 1149 1150 nla_put_failure: 1151 return -EMSGSIZE; 1152 } 1153 1154 static struct rtnl_link_ops gtp_link_ops __read_mostly = { 1155 .kind = "gtp", 1156 .maxtype = IFLA_GTP_MAX, 1157 .policy = gtp_policy, 1158 .priv_size = sizeof(struct gtp_dev), 1159 .setup = gtp_link_setup, 1160 .validate = gtp_validate, 1161 .newlink = gtp_newlink, 1162 .dellink = gtp_dellink, 1163 .get_size = gtp_get_size, 1164 .fill_info = gtp_fill_info, 1165 }; 1166 1167 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize) 1168 { 1169 int i; 1170 1171 gtp->addr_hash = kmalloc_array(hsize, sizeof(struct hlist_head), 1172 GFP_KERNEL | __GFP_NOWARN); 1173 if (gtp->addr_hash == NULL) 1174 return -ENOMEM; 1175 1176 gtp->tid_hash = kmalloc_array(hsize, sizeof(struct hlist_head), 1177 GFP_KERNEL | __GFP_NOWARN); 1178 if (gtp->tid_hash == NULL) 1179 goto err1; 1180 1181 gtp->hash_size = hsize; 1182 1183 for (i = 0; i < hsize; i++) { 1184 INIT_HLIST_HEAD(>p->addr_hash[i]); 1185 INIT_HLIST_HEAD(>p->tid_hash[i]); 1186 } 1187 return 0; 1188 err1: 1189 kfree(gtp->addr_hash); 1190 return -ENOMEM; 1191 } 1192 1193 static struct sock *gtp_encap_enable_socket(int fd, int type, 1194 struct gtp_dev *gtp) 1195 { 1196 struct udp_tunnel_sock_cfg tuncfg = {NULL}; 1197 struct socket *sock; 1198 struct sock *sk; 1199 int err; 1200 1201 pr_debug("enable gtp on %d, %d\n", fd, type); 1202 1203 sock = sockfd_lookup(fd, &err); 1204 if (!sock) { 1205 pr_debug("gtp socket fd=%d not found\n", fd); 1206 return NULL; 1207 } 1208 1209 sk = sock->sk; 1210 if (sk->sk_protocol != IPPROTO_UDP || 1211 sk->sk_type != SOCK_DGRAM || 1212 (sk->sk_family != AF_INET && sk->sk_family != AF_INET6)) { 1213 pr_debug("socket fd=%d not UDP\n", fd); 1214 sk = ERR_PTR(-EINVAL); 1215 goto out_sock; 1216 } 1217 1218 lock_sock(sk); 1219 if (sk->sk_user_data) { 1220 sk = ERR_PTR(-EBUSY); 1221 goto out_rel_sock; 1222 } 1223 1224 sock_hold(sk); 1225 1226 tuncfg.sk_user_data = gtp; 1227 tuncfg.encap_type = type; 1228 tuncfg.encap_rcv = gtp_encap_recv; 1229 tuncfg.encap_destroy = gtp_encap_destroy; 1230 1231 setup_udp_tunnel_sock(sock_net(sock->sk), sock, &tuncfg); 1232 1233 out_rel_sock: 1234 release_sock(sock->sk); 1235 out_sock: 1236 sockfd_put(sock); 1237 return sk; 1238 } 1239 1240 static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]) 1241 { 1242 struct sock *sk1u = NULL; 1243 struct sock *sk0 = NULL; 1244 1245 if (!data[IFLA_GTP_FD0] && !data[IFLA_GTP_FD1]) 1246 return -EINVAL; 1247 1248 if (data[IFLA_GTP_FD0]) { 1249 u32 fd0 = nla_get_u32(data[IFLA_GTP_FD0]); 1250 1251 sk0 = gtp_encap_enable_socket(fd0, UDP_ENCAP_GTP0, gtp); 1252 if (IS_ERR(sk0)) 1253 return PTR_ERR(sk0); 1254 } 1255 1256 if (data[IFLA_GTP_FD1]) { 1257 u32 fd1 = nla_get_u32(data[IFLA_GTP_FD1]); 1258 1259 sk1u = gtp_encap_enable_socket(fd1, UDP_ENCAP_GTP1U, gtp); 1260 if (IS_ERR(sk1u)) { 1261 gtp_encap_disable_sock(sk0); 1262 return PTR_ERR(sk1u); 1263 } 1264 } 1265 1266 gtp->sk0 = sk0; 1267 gtp->sk1u = sk1u; 1268 1269 return 0; 1270 } 1271 1272 static struct gtp_dev *gtp_find_dev(struct net *src_net, struct nlattr *nla[]) 1273 { 1274 struct gtp_dev *gtp = NULL; 1275 struct net_device *dev; 1276 struct net *net; 1277 1278 /* Examine the link attributes and figure out which network namespace 1279 * we are talking about. 1280 */ 1281 if (nla[GTPA_NET_NS_FD]) 1282 net = get_net_ns_by_fd(nla_get_u32(nla[GTPA_NET_NS_FD])); 1283 else 1284 net = get_net(src_net); 1285 1286 if (IS_ERR(net)) 1287 return NULL; 1288 1289 /* Check if there's an existing gtpX device to configure */ 1290 dev = dev_get_by_index_rcu(net, nla_get_u32(nla[GTPA_LINK])); 1291 if (dev && dev->netdev_ops == >p_netdev_ops) 1292 gtp = netdev_priv(dev); 1293 1294 put_net(net); 1295 return gtp; 1296 } 1297 1298 static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info) 1299 { 1300 pctx->gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]); 1301 pctx->af = AF_INET; 1302 pctx->peer_addr_ip4.s_addr = 1303 nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]); 1304 pctx->ms_addr_ip4.s_addr = 1305 nla_get_be32(info->attrs[GTPA_MS_ADDRESS]); 1306 1307 switch (pctx->gtp_version) { 1308 case GTP_V0: 1309 /* According to TS 09.60, sections 7.5.1 and 7.5.2, the flow 1310 * label needs to be the same for uplink and downlink packets, 1311 * so let's annotate this. 1312 */ 1313 pctx->u.v0.tid = nla_get_u64(info->attrs[GTPA_TID]); 1314 pctx->u.v0.flow = nla_get_u16(info->attrs[GTPA_FLOW]); 1315 break; 1316 case GTP_V1: 1317 pctx->u.v1.i_tei = nla_get_u32(info->attrs[GTPA_I_TEI]); 1318 pctx->u.v1.o_tei = nla_get_u32(info->attrs[GTPA_O_TEI]); 1319 break; 1320 default: 1321 break; 1322 } 1323 } 1324 1325 static struct pdp_ctx *gtp_pdp_add(struct gtp_dev *gtp, struct sock *sk, 1326 struct genl_info *info) 1327 { 1328 struct pdp_ctx *pctx, *pctx_tid = NULL; 1329 struct net_device *dev = gtp->dev; 1330 u32 hash_ms, hash_tid = 0; 1331 unsigned int version; 1332 bool found = false; 1333 __be32 ms_addr; 1334 1335 ms_addr = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]); 1336 hash_ms = ipv4_hashfn(ms_addr) % gtp->hash_size; 1337 version = nla_get_u32(info->attrs[GTPA_VERSION]); 1338 1339 pctx = ipv4_pdp_find(gtp, ms_addr); 1340 if (pctx) 1341 found = true; 1342 if (version == GTP_V0) 1343 pctx_tid = gtp0_pdp_find(gtp, 1344 nla_get_u64(info->attrs[GTPA_TID])); 1345 else if (version == GTP_V1) 1346 pctx_tid = gtp1_pdp_find(gtp, 1347 nla_get_u32(info->attrs[GTPA_I_TEI])); 1348 if (pctx_tid) 1349 found = true; 1350 1351 if (found) { 1352 if (info->nlhdr->nlmsg_flags & NLM_F_EXCL) 1353 return ERR_PTR(-EEXIST); 1354 if (info->nlhdr->nlmsg_flags & NLM_F_REPLACE) 1355 return ERR_PTR(-EOPNOTSUPP); 1356 1357 if (pctx && pctx_tid) 1358 return ERR_PTR(-EEXIST); 1359 if (!pctx) 1360 pctx = pctx_tid; 1361 1362 ipv4_pdp_fill(pctx, info); 1363 1364 if (pctx->gtp_version == GTP_V0) 1365 netdev_dbg(dev, "GTPv0-U: update tunnel id = %llx (pdp %p)\n", 1366 pctx->u.v0.tid, pctx); 1367 else if (pctx->gtp_version == GTP_V1) 1368 netdev_dbg(dev, "GTPv1-U: update tunnel id = %x/%x (pdp %p)\n", 1369 pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx); 1370 1371 return pctx; 1372 1373 } 1374 1375 pctx = kmalloc(sizeof(*pctx), GFP_ATOMIC); 1376 if (pctx == NULL) 1377 return ERR_PTR(-ENOMEM); 1378 1379 sock_hold(sk); 1380 pctx->sk = sk; 1381 pctx->dev = gtp->dev; 1382 ipv4_pdp_fill(pctx, info); 1383 atomic_set(&pctx->tx_seq, 0); 1384 1385 switch (pctx->gtp_version) { 1386 case GTP_V0: 1387 /* TS 09.60: "The flow label identifies unambiguously a GTP 1388 * flow.". We use the tid for this instead, I cannot find a 1389 * situation in which this doesn't unambiguosly identify the 1390 * PDP context. 1391 */ 1392 hash_tid = gtp0_hashfn(pctx->u.v0.tid) % gtp->hash_size; 1393 break; 1394 case GTP_V1: 1395 hash_tid = gtp1u_hashfn(pctx->u.v1.i_tei) % gtp->hash_size; 1396 break; 1397 } 1398 1399 hlist_add_head_rcu(&pctx->hlist_addr, >p->addr_hash[hash_ms]); 1400 hlist_add_head_rcu(&pctx->hlist_tid, >p->tid_hash[hash_tid]); 1401 1402 switch (pctx->gtp_version) { 1403 case GTP_V0: 1404 netdev_dbg(dev, "GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n", 1405 pctx->u.v0.tid, &pctx->peer_addr_ip4, 1406 &pctx->ms_addr_ip4, pctx); 1407 break; 1408 case GTP_V1: 1409 netdev_dbg(dev, "GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n", 1410 pctx->u.v1.i_tei, pctx->u.v1.o_tei, 1411 &pctx->peer_addr_ip4, &pctx->ms_addr_ip4, pctx); 1412 break; 1413 } 1414 1415 return pctx; 1416 } 1417 1418 static void pdp_context_free(struct rcu_head *head) 1419 { 1420 struct pdp_ctx *pctx = container_of(head, struct pdp_ctx, rcu_head); 1421 1422 sock_put(pctx->sk); 1423 kfree(pctx); 1424 } 1425 1426 static void pdp_context_delete(struct pdp_ctx *pctx) 1427 { 1428 hlist_del_rcu(&pctx->hlist_tid); 1429 hlist_del_rcu(&pctx->hlist_addr); 1430 call_rcu(&pctx->rcu_head, pdp_context_free); 1431 } 1432 1433 static int gtp_tunnel_notify(struct pdp_ctx *pctx, u8 cmd, gfp_t allocation); 1434 1435 static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info) 1436 { 1437 unsigned int version; 1438 struct pdp_ctx *pctx; 1439 struct gtp_dev *gtp; 1440 struct sock *sk; 1441 int err; 1442 1443 if (!info->attrs[GTPA_VERSION] || 1444 !info->attrs[GTPA_LINK] || 1445 !info->attrs[GTPA_PEER_ADDRESS] || 1446 !info->attrs[GTPA_MS_ADDRESS]) 1447 return -EINVAL; 1448 1449 version = nla_get_u32(info->attrs[GTPA_VERSION]); 1450 1451 switch (version) { 1452 case GTP_V0: 1453 if (!info->attrs[GTPA_TID] || 1454 !info->attrs[GTPA_FLOW]) 1455 return -EINVAL; 1456 break; 1457 case GTP_V1: 1458 if (!info->attrs[GTPA_I_TEI] || 1459 !info->attrs[GTPA_O_TEI]) 1460 return -EINVAL; 1461 break; 1462 1463 default: 1464 return -EINVAL; 1465 } 1466 1467 rtnl_lock(); 1468 1469 gtp = gtp_find_dev(sock_net(skb->sk), info->attrs); 1470 if (!gtp) { 1471 err = -ENODEV; 1472 goto out_unlock; 1473 } 1474 1475 if (version == GTP_V0) 1476 sk = gtp->sk0; 1477 else if (version == GTP_V1) 1478 sk = gtp->sk1u; 1479 else 1480 sk = NULL; 1481 1482 if (!sk) { 1483 err = -ENODEV; 1484 goto out_unlock; 1485 } 1486 1487 pctx = gtp_pdp_add(gtp, sk, info); 1488 if (IS_ERR(pctx)) { 1489 err = PTR_ERR(pctx); 1490 } else { 1491 gtp_tunnel_notify(pctx, GTP_CMD_NEWPDP, GFP_KERNEL); 1492 err = 0; 1493 } 1494 1495 out_unlock: 1496 rtnl_unlock(); 1497 return err; 1498 } 1499 1500 static struct pdp_ctx *gtp_find_pdp_by_link(struct net *net, 1501 struct nlattr *nla[]) 1502 { 1503 struct gtp_dev *gtp; 1504 1505 gtp = gtp_find_dev(net, nla); 1506 if (!gtp) 1507 return ERR_PTR(-ENODEV); 1508 1509 if (nla[GTPA_MS_ADDRESS]) { 1510 __be32 ip = nla_get_be32(nla[GTPA_MS_ADDRESS]); 1511 1512 return ipv4_pdp_find(gtp, ip); 1513 } else if (nla[GTPA_VERSION]) { 1514 u32 gtp_version = nla_get_u32(nla[GTPA_VERSION]); 1515 1516 if (gtp_version == GTP_V0 && nla[GTPA_TID]) 1517 return gtp0_pdp_find(gtp, nla_get_u64(nla[GTPA_TID])); 1518 else if (gtp_version == GTP_V1 && nla[GTPA_I_TEI]) 1519 return gtp1_pdp_find(gtp, nla_get_u32(nla[GTPA_I_TEI])); 1520 } 1521 1522 return ERR_PTR(-EINVAL); 1523 } 1524 1525 static struct pdp_ctx *gtp_find_pdp(struct net *net, struct nlattr *nla[]) 1526 { 1527 struct pdp_ctx *pctx; 1528 1529 if (nla[GTPA_LINK]) 1530 pctx = gtp_find_pdp_by_link(net, nla); 1531 else 1532 pctx = ERR_PTR(-EINVAL); 1533 1534 if (!pctx) 1535 pctx = ERR_PTR(-ENOENT); 1536 1537 return pctx; 1538 } 1539 1540 static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info) 1541 { 1542 struct pdp_ctx *pctx; 1543 int err = 0; 1544 1545 if (!info->attrs[GTPA_VERSION]) 1546 return -EINVAL; 1547 1548 rcu_read_lock(); 1549 1550 pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs); 1551 if (IS_ERR(pctx)) { 1552 err = PTR_ERR(pctx); 1553 goto out_unlock; 1554 } 1555 1556 if (pctx->gtp_version == GTP_V0) 1557 netdev_dbg(pctx->dev, "GTPv0-U: deleting tunnel id = %llx (pdp %p)\n", 1558 pctx->u.v0.tid, pctx); 1559 else if (pctx->gtp_version == GTP_V1) 1560 netdev_dbg(pctx->dev, "GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n", 1561 pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx); 1562 1563 gtp_tunnel_notify(pctx, GTP_CMD_DELPDP, GFP_ATOMIC); 1564 pdp_context_delete(pctx); 1565 1566 out_unlock: 1567 rcu_read_unlock(); 1568 return err; 1569 } 1570 1571 static int gtp_genl_fill_info(struct sk_buff *skb, u32 snd_portid, u32 snd_seq, 1572 int flags, u32 type, struct pdp_ctx *pctx) 1573 { 1574 void *genlh; 1575 1576 genlh = genlmsg_put(skb, snd_portid, snd_seq, >p_genl_family, flags, 1577 type); 1578 if (genlh == NULL) 1579 goto nlmsg_failure; 1580 1581 if (nla_put_u32(skb, GTPA_VERSION, pctx->gtp_version) || 1582 nla_put_u32(skb, GTPA_LINK, pctx->dev->ifindex) || 1583 nla_put_be32(skb, GTPA_PEER_ADDRESS, pctx->peer_addr_ip4.s_addr) || 1584 nla_put_be32(skb, GTPA_MS_ADDRESS, pctx->ms_addr_ip4.s_addr)) 1585 goto nla_put_failure; 1586 1587 switch (pctx->gtp_version) { 1588 case GTP_V0: 1589 if (nla_put_u64_64bit(skb, GTPA_TID, pctx->u.v0.tid, GTPA_PAD) || 1590 nla_put_u16(skb, GTPA_FLOW, pctx->u.v0.flow)) 1591 goto nla_put_failure; 1592 break; 1593 case GTP_V1: 1594 if (nla_put_u32(skb, GTPA_I_TEI, pctx->u.v1.i_tei) || 1595 nla_put_u32(skb, GTPA_O_TEI, pctx->u.v1.o_tei)) 1596 goto nla_put_failure; 1597 break; 1598 } 1599 genlmsg_end(skb, genlh); 1600 return 0; 1601 1602 nlmsg_failure: 1603 nla_put_failure: 1604 genlmsg_cancel(skb, genlh); 1605 return -EMSGSIZE; 1606 } 1607 1608 static int gtp_tunnel_notify(struct pdp_ctx *pctx, u8 cmd, gfp_t allocation) 1609 { 1610 struct sk_buff *msg; 1611 int ret; 1612 1613 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, allocation); 1614 if (!msg) 1615 return -ENOMEM; 1616 1617 ret = gtp_genl_fill_info(msg, 0, 0, 0, cmd, pctx); 1618 if (ret < 0) { 1619 nlmsg_free(msg); 1620 return ret; 1621 } 1622 1623 ret = genlmsg_multicast_netns(>p_genl_family, dev_net(pctx->dev), msg, 1624 0, GTP_GENL_MCGRP, GFP_ATOMIC); 1625 return ret; 1626 } 1627 1628 static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info) 1629 { 1630 struct pdp_ctx *pctx = NULL; 1631 struct sk_buff *skb2; 1632 int err; 1633 1634 if (!info->attrs[GTPA_VERSION]) 1635 return -EINVAL; 1636 1637 rcu_read_lock(); 1638 1639 pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs); 1640 if (IS_ERR(pctx)) { 1641 err = PTR_ERR(pctx); 1642 goto err_unlock; 1643 } 1644 1645 skb2 = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC); 1646 if (skb2 == NULL) { 1647 err = -ENOMEM; 1648 goto err_unlock; 1649 } 1650 1651 err = gtp_genl_fill_info(skb2, NETLINK_CB(skb).portid, info->snd_seq, 1652 0, info->nlhdr->nlmsg_type, pctx); 1653 if (err < 0) 1654 goto err_unlock_free; 1655 1656 rcu_read_unlock(); 1657 return genlmsg_unicast(genl_info_net(info), skb2, info->snd_portid); 1658 1659 err_unlock_free: 1660 kfree_skb(skb2); 1661 err_unlock: 1662 rcu_read_unlock(); 1663 return err; 1664 } 1665 1666 static int gtp_genl_dump_pdp(struct sk_buff *skb, 1667 struct netlink_callback *cb) 1668 { 1669 struct gtp_dev *last_gtp = (struct gtp_dev *)cb->args[2], *gtp; 1670 int i, j, bucket = cb->args[0], skip = cb->args[1]; 1671 struct net *net = sock_net(skb->sk); 1672 struct pdp_ctx *pctx; 1673 struct gtp_net *gn; 1674 1675 gn = net_generic(net, gtp_net_id); 1676 1677 if (cb->args[4]) 1678 return 0; 1679 1680 rcu_read_lock(); 1681 list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) { 1682 if (last_gtp && last_gtp != gtp) 1683 continue; 1684 else 1685 last_gtp = NULL; 1686 1687 for (i = bucket; i < gtp->hash_size; i++) { 1688 j = 0; 1689 hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], 1690 hlist_tid) { 1691 if (j >= skip && 1692 gtp_genl_fill_info(skb, 1693 NETLINK_CB(cb->skb).portid, 1694 cb->nlh->nlmsg_seq, 1695 NLM_F_MULTI, 1696 cb->nlh->nlmsg_type, pctx)) { 1697 cb->args[0] = i; 1698 cb->args[1] = j; 1699 cb->args[2] = (unsigned long)gtp; 1700 goto out; 1701 } 1702 j++; 1703 } 1704 skip = 0; 1705 } 1706 bucket = 0; 1707 } 1708 cb->args[4] = 1; 1709 out: 1710 rcu_read_unlock(); 1711 return skb->len; 1712 } 1713 1714 static int gtp_genl_send_echo_req(struct sk_buff *skb, struct genl_info *info) 1715 { 1716 struct sk_buff *skb_to_send; 1717 __be32 src_ip, dst_ip; 1718 unsigned int version; 1719 struct gtp_dev *gtp; 1720 struct flowi4 fl4; 1721 struct rtable *rt; 1722 struct sock *sk; 1723 __be16 port; 1724 int len; 1725 1726 if (!info->attrs[GTPA_VERSION] || 1727 !info->attrs[GTPA_LINK] || 1728 !info->attrs[GTPA_PEER_ADDRESS] || 1729 !info->attrs[GTPA_MS_ADDRESS]) 1730 return -EINVAL; 1731 1732 version = nla_get_u32(info->attrs[GTPA_VERSION]); 1733 dst_ip = nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]); 1734 src_ip = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]); 1735 1736 gtp = gtp_find_dev(sock_net(skb->sk), info->attrs); 1737 if (!gtp) 1738 return -ENODEV; 1739 1740 if (!gtp->sk_created) 1741 return -EOPNOTSUPP; 1742 if (!(gtp->dev->flags & IFF_UP)) 1743 return -ENETDOWN; 1744 1745 if (version == GTP_V0) { 1746 struct gtp0_header *gtp0_h; 1747 1748 len = LL_RESERVED_SPACE(gtp->dev) + sizeof(struct gtp0_header) + 1749 sizeof(struct iphdr) + sizeof(struct udphdr); 1750 1751 skb_to_send = netdev_alloc_skb_ip_align(gtp->dev, len); 1752 if (!skb_to_send) 1753 return -ENOMEM; 1754 1755 sk = gtp->sk0; 1756 port = htons(GTP0_PORT); 1757 1758 gtp0_h = skb_push(skb_to_send, sizeof(struct gtp0_header)); 1759 memset(gtp0_h, 0, sizeof(struct gtp0_header)); 1760 gtp0_build_echo_msg(gtp0_h, GTP_ECHO_REQ); 1761 } else if (version == GTP_V1) { 1762 struct gtp1_header_long *gtp1u_h; 1763 1764 len = LL_RESERVED_SPACE(gtp->dev) + 1765 sizeof(struct gtp1_header_long) + 1766 sizeof(struct iphdr) + sizeof(struct udphdr); 1767 1768 skb_to_send = netdev_alloc_skb_ip_align(gtp->dev, len); 1769 if (!skb_to_send) 1770 return -ENOMEM; 1771 1772 sk = gtp->sk1u; 1773 port = htons(GTP1U_PORT); 1774 1775 gtp1u_h = skb_push(skb_to_send, 1776 sizeof(struct gtp1_header_long)); 1777 memset(gtp1u_h, 0, sizeof(struct gtp1_header_long)); 1778 gtp1u_build_echo_msg(gtp1u_h, GTP_ECHO_REQ); 1779 } else { 1780 return -ENODEV; 1781 } 1782 1783 rt = ip4_route_output_gtp(&fl4, sk, dst_ip, src_ip); 1784 if (IS_ERR(rt)) { 1785 netdev_dbg(gtp->dev, "no route for echo request to %pI4\n", 1786 &dst_ip); 1787 kfree_skb(skb_to_send); 1788 return -ENODEV; 1789 } 1790 1791 udp_tunnel_xmit_skb(rt, sk, skb_to_send, 1792 fl4.saddr, fl4.daddr, 1793 fl4.flowi4_tos, 1794 ip4_dst_hoplimit(&rt->dst), 1795 0, 1796 port, port, 1797 !net_eq(sock_net(sk), 1798 dev_net(gtp->dev)), 1799 false); 1800 return 0; 1801 } 1802 1803 static const struct nla_policy gtp_genl_policy[GTPA_MAX + 1] = { 1804 [GTPA_LINK] = { .type = NLA_U32, }, 1805 [GTPA_VERSION] = { .type = NLA_U32, }, 1806 [GTPA_TID] = { .type = NLA_U64, }, 1807 [GTPA_PEER_ADDRESS] = { .type = NLA_U32, }, 1808 [GTPA_MS_ADDRESS] = { .type = NLA_U32, }, 1809 [GTPA_FLOW] = { .type = NLA_U16, }, 1810 [GTPA_NET_NS_FD] = { .type = NLA_U32, }, 1811 [GTPA_I_TEI] = { .type = NLA_U32, }, 1812 [GTPA_O_TEI] = { .type = NLA_U32, }, 1813 }; 1814 1815 static const struct genl_small_ops gtp_genl_ops[] = { 1816 { 1817 .cmd = GTP_CMD_NEWPDP, 1818 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, 1819 .doit = gtp_genl_new_pdp, 1820 .flags = GENL_ADMIN_PERM, 1821 }, 1822 { 1823 .cmd = GTP_CMD_DELPDP, 1824 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, 1825 .doit = gtp_genl_del_pdp, 1826 .flags = GENL_ADMIN_PERM, 1827 }, 1828 { 1829 .cmd = GTP_CMD_GETPDP, 1830 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, 1831 .doit = gtp_genl_get_pdp, 1832 .dumpit = gtp_genl_dump_pdp, 1833 .flags = GENL_ADMIN_PERM, 1834 }, 1835 { 1836 .cmd = GTP_CMD_ECHOREQ, 1837 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, 1838 .doit = gtp_genl_send_echo_req, 1839 .flags = GENL_ADMIN_PERM, 1840 }, 1841 }; 1842 1843 static struct genl_family gtp_genl_family __ro_after_init = { 1844 .name = "gtp", 1845 .version = 0, 1846 .hdrsize = 0, 1847 .maxattr = GTPA_MAX, 1848 .policy = gtp_genl_policy, 1849 .netnsok = true, 1850 .module = THIS_MODULE, 1851 .small_ops = gtp_genl_ops, 1852 .n_small_ops = ARRAY_SIZE(gtp_genl_ops), 1853 .resv_start_op = GTP_CMD_ECHOREQ + 1, 1854 .mcgrps = gtp_genl_mcgrps, 1855 .n_mcgrps = ARRAY_SIZE(gtp_genl_mcgrps), 1856 }; 1857 1858 static int __net_init gtp_net_init(struct net *net) 1859 { 1860 struct gtp_net *gn = net_generic(net, gtp_net_id); 1861 1862 INIT_LIST_HEAD(&gn->gtp_dev_list); 1863 return 0; 1864 } 1865 1866 static void __net_exit gtp_net_exit_batch_rtnl(struct list_head *net_list, 1867 struct list_head *dev_to_kill) 1868 { 1869 struct net *net; 1870 1871 list_for_each_entry(net, net_list, exit_list) { 1872 struct gtp_net *gn = net_generic(net, gtp_net_id); 1873 struct gtp_dev *gtp; 1874 1875 list_for_each_entry(gtp, &gn->gtp_dev_list, list) 1876 gtp_dellink(gtp->dev, dev_to_kill); 1877 } 1878 } 1879 1880 static struct pernet_operations gtp_net_ops = { 1881 .init = gtp_net_init, 1882 .exit_batch_rtnl = gtp_net_exit_batch_rtnl, 1883 .id = >p_net_id, 1884 .size = sizeof(struct gtp_net), 1885 }; 1886 1887 static int __init gtp_init(void) 1888 { 1889 int err; 1890 1891 get_random_bytes(>p_h_initval, sizeof(gtp_h_initval)); 1892 1893 err = register_pernet_subsys(>p_net_ops); 1894 if (err < 0) 1895 goto error_out; 1896 1897 err = rtnl_link_register(>p_link_ops); 1898 if (err < 0) 1899 goto unreg_pernet_subsys; 1900 1901 err = genl_register_family(>p_genl_family); 1902 if (err < 0) 1903 goto unreg_rtnl_link; 1904 1905 pr_info("GTP module loaded (pdp ctx size %zd bytes)\n", 1906 sizeof(struct pdp_ctx)); 1907 return 0; 1908 1909 unreg_rtnl_link: 1910 rtnl_link_unregister(>p_link_ops); 1911 unreg_pernet_subsys: 1912 unregister_pernet_subsys(>p_net_ops); 1913 error_out: 1914 pr_err("error loading GTP module loaded\n"); 1915 return err; 1916 } 1917 late_initcall(gtp_init); 1918 1919 static void __exit gtp_fini(void) 1920 { 1921 genl_unregister_family(>p_genl_family); 1922 rtnl_link_unregister(>p_link_ops); 1923 unregister_pernet_subsys(>p_net_ops); 1924 1925 pr_info("GTP module unloaded\n"); 1926 } 1927 module_exit(gtp_fini); 1928 1929 MODULE_LICENSE("GPL"); 1930 MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>"); 1931 MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic"); 1932 MODULE_ALIAS_RTNL_LINK("gtp"); 1933 MODULE_ALIAS_GENL_FAMILY("gtp"); 1934