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/dst_metadata.h> 25 #include <net/net_namespace.h> 26 #include <net/protocol.h> 27 #include <net/ip.h> 28 #include <net/udp.h> 29 #include <net/udp_tunnel.h> 30 #include <net/icmp.h> 31 #include <net/xfrm.h> 32 #include <net/genetlink.h> 33 #include <net/netns/generic.h> 34 #include <net/gtp.h> 35 36 /* An active session for the subscriber. */ 37 struct pdp_ctx { 38 struct hlist_node hlist_tid; 39 struct hlist_node hlist_addr; 40 41 union { 42 struct { 43 u64 tid; 44 u16 flow; 45 } v0; 46 struct { 47 u32 i_tei; 48 u32 o_tei; 49 } v1; 50 } u; 51 u8 gtp_version; 52 u16 af; 53 54 struct in_addr ms_addr_ip4; 55 struct in_addr peer_addr_ip4; 56 57 struct sock *sk; 58 struct net_device *dev; 59 60 atomic_t tx_seq; 61 struct rcu_head rcu_head; 62 }; 63 64 /* One instance of the GTP device. */ 65 struct gtp_dev { 66 struct list_head list; 67 68 struct sock *sk0; 69 struct sock *sk1u; 70 71 struct net_device *dev; 72 73 unsigned int role; 74 unsigned int hash_size; 75 struct hlist_head *tid_hash; 76 struct hlist_head *addr_hash; 77 /* Used by LWT tunnel. */ 78 bool collect_md; 79 struct socket *collect_md_sock; 80 }; 81 82 static unsigned int gtp_net_id __read_mostly; 83 84 struct gtp_net { 85 struct list_head gtp_dev_list; 86 }; 87 88 static u32 gtp_h_initval; 89 90 static void pdp_context_delete(struct pdp_ctx *pctx); 91 92 static inline u32 gtp0_hashfn(u64 tid) 93 { 94 u32 *tid32 = (u32 *) &tid; 95 return jhash_2words(tid32[0], tid32[1], gtp_h_initval); 96 } 97 98 static inline u32 gtp1u_hashfn(u32 tid) 99 { 100 return jhash_1word(tid, gtp_h_initval); 101 } 102 103 static inline u32 ipv4_hashfn(__be32 ip) 104 { 105 return jhash_1word((__force u32)ip, gtp_h_initval); 106 } 107 108 /* Resolve a PDP context structure based on the 64bit TID. */ 109 static struct pdp_ctx *gtp0_pdp_find(struct gtp_dev *gtp, u64 tid) 110 { 111 struct hlist_head *head; 112 struct pdp_ctx *pdp; 113 114 head = >p->tid_hash[gtp0_hashfn(tid) % gtp->hash_size]; 115 116 hlist_for_each_entry_rcu(pdp, head, hlist_tid) { 117 if (pdp->gtp_version == GTP_V0 && 118 pdp->u.v0.tid == tid) 119 return pdp; 120 } 121 return NULL; 122 } 123 124 /* Resolve a PDP context structure based on the 32bit TEI. */ 125 static struct pdp_ctx *gtp1_pdp_find(struct gtp_dev *gtp, u32 tid) 126 { 127 struct hlist_head *head; 128 struct pdp_ctx *pdp; 129 130 head = >p->tid_hash[gtp1u_hashfn(tid) % gtp->hash_size]; 131 132 hlist_for_each_entry_rcu(pdp, head, hlist_tid) { 133 if (pdp->gtp_version == GTP_V1 && 134 pdp->u.v1.i_tei == tid) 135 return pdp; 136 } 137 return NULL; 138 } 139 140 /* Resolve a PDP context based on IPv4 address of MS. */ 141 static struct pdp_ctx *ipv4_pdp_find(struct gtp_dev *gtp, __be32 ms_addr) 142 { 143 struct hlist_head *head; 144 struct pdp_ctx *pdp; 145 146 head = >p->addr_hash[ipv4_hashfn(ms_addr) % gtp->hash_size]; 147 148 hlist_for_each_entry_rcu(pdp, head, hlist_addr) { 149 if (pdp->af == AF_INET && 150 pdp->ms_addr_ip4.s_addr == ms_addr) 151 return pdp; 152 } 153 154 return NULL; 155 } 156 157 static bool gtp_check_ms_ipv4(struct sk_buff *skb, struct pdp_ctx *pctx, 158 unsigned int hdrlen, unsigned int role) 159 { 160 struct iphdr *iph; 161 162 if (!pskb_may_pull(skb, hdrlen + sizeof(struct iphdr))) 163 return false; 164 165 iph = (struct iphdr *)(skb->data + hdrlen); 166 167 if (role == GTP_ROLE_SGSN) 168 return iph->daddr == pctx->ms_addr_ip4.s_addr; 169 else 170 return iph->saddr == pctx->ms_addr_ip4.s_addr; 171 } 172 173 /* Check if the inner IP address in this packet is assigned to any 174 * existing mobile subscriber. 175 */ 176 static bool gtp_check_ms(struct sk_buff *skb, struct pdp_ctx *pctx, 177 unsigned int hdrlen, unsigned int role) 178 { 179 switch (ntohs(skb->protocol)) { 180 case ETH_P_IP: 181 return gtp_check_ms_ipv4(skb, pctx, hdrlen, role); 182 } 183 return false; 184 } 185 186 static int gtp_set_tun_dst(struct gtp_dev *gtp, struct sk_buff *skb, 187 unsigned int hdrlen, u8 gtp_version, 188 __be64 tid, u8 flags) 189 { 190 struct metadata_dst *tun_dst; 191 int opts_len = 0; 192 193 if (unlikely(flags & GTP1_F_MASK)) 194 opts_len = sizeof(struct gtpu_metadata); 195 196 tun_dst = udp_tun_rx_dst(skb, gtp->sk1u->sk_family, TUNNEL_KEY, tid, opts_len); 197 if (!tun_dst) { 198 netdev_dbg(gtp->dev, "Failed to allocate tun_dst"); 199 goto err; 200 } 201 202 netdev_dbg(gtp->dev, "attaching metadata_dst to skb, gtp ver %d hdrlen %d\n", 203 gtp_version, hdrlen); 204 if (unlikely(opts_len)) { 205 struct gtpu_metadata *opts; 206 struct gtp1_header *gtp1; 207 208 opts = ip_tunnel_info_opts(&tun_dst->u.tun_info); 209 gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr)); 210 opts->ver = GTP_METADATA_V1; 211 opts->flags = gtp1->flags; 212 opts->type = gtp1->type; 213 netdev_dbg(gtp->dev, "recved control pkt: flag %x type: %d\n", 214 opts->flags, opts->type); 215 tun_dst->u.tun_info.key.tun_flags |= TUNNEL_GTPU_OPT; 216 tun_dst->u.tun_info.options_len = opts_len; 217 skb->protocol = htons(0xffff); /* Unknown */ 218 } 219 /* Get rid of the GTP + UDP headers. */ 220 if (iptunnel_pull_header(skb, hdrlen, skb->protocol, 221 !net_eq(sock_net(gtp->sk1u), dev_net(gtp->dev)))) { 222 gtp->dev->stats.rx_length_errors++; 223 goto err; 224 } 225 226 skb_dst_set(skb, &tun_dst->dst); 227 return 0; 228 err: 229 return -1; 230 } 231 232 static int gtp_rx(struct gtp_dev *gtp, struct sk_buff *skb, 233 unsigned int hdrlen, u8 gtp_version, unsigned int role, 234 __be64 tid, u8 flags, u8 type) 235 { 236 if (ip_tunnel_collect_metadata() || gtp->collect_md) { 237 int err; 238 239 err = gtp_set_tun_dst(gtp, skb, hdrlen, gtp_version, tid, flags); 240 if (err) 241 goto err; 242 } else { 243 struct pdp_ctx *pctx; 244 245 if (flags & GTP1_F_MASK) 246 hdrlen += 4; 247 248 if (type != GTP_TPDU) 249 return 1; 250 251 if (gtp_version == GTP_V0) 252 pctx = gtp0_pdp_find(gtp, be64_to_cpu(tid)); 253 else 254 pctx = gtp1_pdp_find(gtp, be64_to_cpu(tid)); 255 if (!pctx) { 256 netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb); 257 return 1; 258 } 259 260 if (!gtp_check_ms(skb, pctx, hdrlen, role)) { 261 netdev_dbg(pctx->dev, "No PDP ctx for this MS\n"); 262 return 1; 263 } 264 /* Get rid of the GTP + UDP headers. */ 265 if (iptunnel_pull_header(skb, hdrlen, skb->protocol, 266 !net_eq(sock_net(pctx->sk), dev_net(gtp->dev)))) { 267 gtp->dev->stats.rx_length_errors++; 268 goto err; 269 } 270 } 271 netdev_dbg(gtp->dev, "forwarding packet from GGSN to uplink\n"); 272 273 /* Now that the UDP and the GTP header have been removed, set up the 274 * new network header. This is required by the upper layer to 275 * calculate the transport header. 276 */ 277 skb_reset_network_header(skb); 278 if (pskb_may_pull(skb, sizeof(struct iphdr))) { 279 struct iphdr *iph; 280 281 iph = ip_hdr(skb); 282 if (iph->version == 4) { 283 netdev_dbg(gtp->dev, "inner pkt: ipv4"); 284 skb->protocol = htons(ETH_P_IP); 285 } else if (iph->version == 6) { 286 netdev_dbg(gtp->dev, "inner pkt: ipv6"); 287 skb->protocol = htons(ETH_P_IPV6); 288 } else { 289 netdev_dbg(gtp->dev, "inner pkt error: Unknown type"); 290 } 291 } 292 293 skb->dev = gtp->dev; 294 dev_sw_netstats_rx_add(gtp->dev, skb->len); 295 netif_rx(skb); 296 return 0; 297 298 err: 299 gtp->dev->stats.rx_dropped++; 300 return -1; 301 } 302 303 /* 1 means pass up to the stack, -1 means drop and 0 means decapsulated. */ 304 static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb) 305 { 306 unsigned int hdrlen = sizeof(struct udphdr) + 307 sizeof(struct gtp0_header); 308 struct gtp0_header *gtp0; 309 310 if (!pskb_may_pull(skb, hdrlen)) 311 return -1; 312 313 gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr)); 314 315 if ((gtp0->flags >> 5) != GTP_V0) 316 return 1; 317 318 return gtp_rx(gtp, skb, hdrlen, GTP_V0, gtp->role, gtp0->tid, gtp0->flags, gtp0->type); 319 } 320 321 static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb) 322 { 323 unsigned int hdrlen = sizeof(struct udphdr) + 324 sizeof(struct gtp1_header); 325 struct gtp1_header *gtp1; 326 327 if (!pskb_may_pull(skb, hdrlen)) 328 return -1; 329 330 gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr)); 331 332 netdev_dbg(gtp->dev, "GTPv1 recv: flags %x\n", gtp1->flags); 333 if ((gtp1->flags >> 5) != GTP_V1) 334 return 1; 335 336 /* From 29.060: "This field shall be present if and only if any one or 337 * more of the S, PN and E flags are set.". 338 * 339 * If any of the bit is set, then the remaining ones also have to be 340 * set. 341 */ 342 /* Make sure the header is larger enough, including extensions. */ 343 if (!pskb_may_pull(skb, hdrlen)) 344 return -1; 345 346 gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr)); 347 348 return gtp_rx(gtp, skb, hdrlen, GTP_V1, gtp->role, 349 key32_to_tunnel_id(gtp1->tid), gtp1->flags, gtp1->type); 350 } 351 352 static void __gtp_encap_destroy(struct sock *sk) 353 { 354 struct gtp_dev *gtp; 355 356 lock_sock(sk); 357 gtp = sk->sk_user_data; 358 if (gtp) { 359 if (gtp->sk0 == sk) 360 gtp->sk0 = NULL; 361 else 362 gtp->sk1u = NULL; 363 udp_sk(sk)->encap_type = 0; 364 rcu_assign_sk_user_data(sk, NULL); 365 sock_put(sk); 366 } 367 release_sock(sk); 368 } 369 370 static void gtp_encap_destroy(struct sock *sk) 371 { 372 rtnl_lock(); 373 __gtp_encap_destroy(sk); 374 rtnl_unlock(); 375 } 376 377 static void gtp_encap_disable_sock(struct sock *sk) 378 { 379 if (!sk) 380 return; 381 382 __gtp_encap_destroy(sk); 383 } 384 385 static void gtp_encap_disable(struct gtp_dev *gtp) 386 { 387 gtp_encap_disable_sock(gtp->sk0); 388 gtp_encap_disable_sock(gtp->sk1u); 389 if (gtp->collect_md_sock) { 390 udp_tunnel_sock_release(gtp->collect_md_sock); 391 gtp->collect_md_sock = NULL; 392 netdev_dbg(gtp->dev, "GTP socket released.\n"); 393 } 394 } 395 396 /* UDP encapsulation receive handler. See net/ipv4/udp.c. 397 * Return codes: 0: success, <0: error, >0: pass up to userspace UDP socket. 398 */ 399 static int gtp_encap_recv(struct sock *sk, struct sk_buff *skb) 400 { 401 struct gtp_dev *gtp; 402 int ret = 0; 403 404 gtp = rcu_dereference_sk_user_data(sk); 405 if (!gtp) 406 return 1; 407 408 netdev_dbg(gtp->dev, "encap_recv sk=%p type %d\n", 409 sk, udp_sk(sk)->encap_type); 410 411 switch (udp_sk(sk)->encap_type) { 412 case UDP_ENCAP_GTP0: 413 netdev_dbg(gtp->dev, "received GTP0 packet\n"); 414 ret = gtp0_udp_encap_recv(gtp, skb); 415 break; 416 case UDP_ENCAP_GTP1U: 417 netdev_dbg(gtp->dev, "received GTP1U packet\n"); 418 ret = gtp1u_udp_encap_recv(gtp, skb); 419 break; 420 default: 421 ret = -1; /* Shouldn't happen. */ 422 } 423 424 switch (ret) { 425 case 1: 426 netdev_dbg(gtp->dev, "pass up to the process\n"); 427 break; 428 case 0: 429 break; 430 case -1: 431 netdev_dbg(gtp->dev, "GTP packet has been dropped\n"); 432 kfree_skb(skb); 433 ret = 0; 434 break; 435 } 436 437 return ret; 438 } 439 440 static int gtp_dev_init(struct net_device *dev) 441 { 442 struct gtp_dev *gtp = netdev_priv(dev); 443 444 gtp->dev = dev; 445 446 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); 447 if (!dev->tstats) 448 return -ENOMEM; 449 450 return 0; 451 } 452 453 static void gtp_dev_uninit(struct net_device *dev) 454 { 455 struct gtp_dev *gtp = netdev_priv(dev); 456 457 gtp_encap_disable(gtp); 458 free_percpu(dev->tstats); 459 } 460 461 static struct rtable *ip4_route_output_gtp(struct flowi4 *fl4, 462 const struct sock *sk, 463 __be32 daddr, 464 __be32 saddr) 465 { 466 memset(fl4, 0, sizeof(*fl4)); 467 fl4->flowi4_oif = sk->sk_bound_dev_if; 468 fl4->daddr = daddr; 469 fl4->saddr = saddr; 470 fl4->flowi4_tos = RT_CONN_FLAGS(sk); 471 fl4->flowi4_proto = sk->sk_protocol; 472 473 return ip_route_output_key(sock_net(sk), fl4); 474 } 475 476 static inline void gtp0_push_header(struct sk_buff *skb, struct pdp_ctx *pctx) 477 { 478 int payload_len = skb->len; 479 struct gtp0_header *gtp0; 480 481 gtp0 = skb_push(skb, sizeof(*gtp0)); 482 483 gtp0->flags = 0x1e; /* v0, GTP-non-prime. */ 484 gtp0->type = GTP_TPDU; 485 gtp0->length = htons(payload_len); 486 gtp0->seq = htons((atomic_inc_return(&pctx->tx_seq) - 1) % 0xffff); 487 gtp0->flow = htons(pctx->u.v0.flow); 488 gtp0->number = 0xff; 489 gtp0->spare[0] = gtp0->spare[1] = gtp0->spare[2] = 0xff; 490 gtp0->tid = cpu_to_be64(pctx->u.v0.tid); 491 } 492 493 static inline void gtp1_push_header(struct sk_buff *skb, __be32 tid) 494 { 495 int payload_len = skb->len; 496 struct gtp1_header *gtp1; 497 498 gtp1 = skb_push(skb, sizeof(*gtp1)); 499 500 /* Bits 8 7 6 5 4 3 2 1 501 * +--+--+--+--+--+--+--+--+ 502 * |version |PT| 0| E| S|PN| 503 * +--+--+--+--+--+--+--+--+ 504 * 0 0 1 1 1 0 0 0 505 */ 506 gtp1->flags = 0x30; /* v1, GTP-non-prime. */ 507 gtp1->type = GTP_TPDU; 508 gtp1->length = htons(payload_len); 509 gtp1->tid = tid; 510 511 /* TODO: Suppport for extension header, sequence number and N-PDU. 512 * Update the length field if any of them is available. 513 */ 514 } 515 516 static inline int gtp1_push_control_header(struct sk_buff *skb, 517 __be32 tid, 518 struct gtpu_metadata *opts, 519 struct net_device *dev) 520 { 521 struct gtp1_header *gtp1c; 522 int payload_len; 523 524 if (opts->ver != GTP_METADATA_V1) 525 return -ENOENT; 526 527 if (opts->type == 0xFE) { 528 /* for end marker ignore skb data. */ 529 netdev_dbg(dev, "xmit pkt with null data"); 530 pskb_trim(skb, 0); 531 } 532 if (skb_cow_head(skb, sizeof(*gtp1c)) < 0) 533 return -ENOMEM; 534 535 payload_len = skb->len; 536 537 gtp1c = skb_push(skb, sizeof(*gtp1c)); 538 539 gtp1c->flags = opts->flags; 540 gtp1c->type = opts->type; 541 gtp1c->length = htons(payload_len); 542 gtp1c->tid = tid; 543 netdev_dbg(dev, "xmit control pkt: ver %d flags %x type %x pkt len %d tid %x", 544 opts->ver, opts->flags, opts->type, skb->len, tid); 545 return 0; 546 } 547 548 struct gtp_pktinfo { 549 struct sock *sk; 550 __u8 tos; 551 struct flowi4 fl4; 552 struct rtable *rt; 553 struct net_device *dev; 554 __be16 gtph_port; 555 }; 556 557 static inline void gtp_set_pktinfo_ipv4(struct gtp_pktinfo *pktinfo, 558 struct sock *sk, 559 __u8 tos, 560 struct rtable *rt, 561 struct flowi4 *fl4, 562 struct net_device *dev) 563 { 564 pktinfo->sk = sk; 565 pktinfo->tos = tos; 566 pktinfo->rt = rt; 567 pktinfo->fl4 = *fl4; 568 pktinfo->dev = dev; 569 } 570 571 static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev, 572 struct gtp_pktinfo *pktinfo) 573 { 574 struct gtp_dev *gtp = netdev_priv(dev); 575 struct gtpu_metadata *opts = NULL; 576 struct sock *sk = NULL; 577 struct pdp_ctx *pctx; 578 struct rtable *rt; 579 struct flowi4 fl4; 580 u8 gtp_version; 581 __be16 df = 0; 582 __be32 tun_id; 583 __be32 daddr; 584 __be32 saddr; 585 __u8 tos; 586 int mtu; 587 588 if (gtp->collect_md) { 589 /* LWT GTP1U encap */ 590 struct ip_tunnel_info *info = NULL; 591 592 info = skb_tunnel_info(skb); 593 if (!info) { 594 netdev_dbg(dev, "missing tunnel info"); 595 return -ENOENT; 596 } 597 if (info->key.tp_dst && ntohs(info->key.tp_dst) != GTP1U_PORT) { 598 netdev_dbg(dev, "unexpected GTP dst port: %d", ntohs(info->key.tp_dst)); 599 return -EOPNOTSUPP; 600 } 601 pctx = NULL; 602 gtp_version = GTP_V1; 603 tun_id = tunnel_id_to_key32(info->key.tun_id); 604 daddr = info->key.u.ipv4.dst; 605 saddr = info->key.u.ipv4.src; 606 sk = gtp->sk1u; 607 if (!sk) { 608 netdev_dbg(dev, "missing tunnel sock"); 609 return -EOPNOTSUPP; 610 } 611 tos = info->key.tos; 612 if (info->key.tun_flags & TUNNEL_DONT_FRAGMENT) 613 df = htons(IP_DF); 614 615 if (info->options_len != 0) { 616 if (info->key.tun_flags & TUNNEL_GTPU_OPT) { 617 opts = ip_tunnel_info_opts(info); 618 } else { 619 netdev_dbg(dev, "missing tunnel metadata for control pkt"); 620 return -EOPNOTSUPP; 621 } 622 } 623 netdev_dbg(dev, "flow-based GTP1U encap: tunnel id %d\n", 624 be32_to_cpu(tun_id)); 625 } else { 626 struct iphdr *iph; 627 628 if (ntohs(skb->protocol) != ETH_P_IP) 629 return -EOPNOTSUPP; 630 631 iph = ip_hdr(skb); 632 633 /* Read the IP destination address and resolve the PDP context. 634 * Prepend PDP header with TEI/TID from PDP ctx. 635 */ 636 if (gtp->role == GTP_ROLE_SGSN) 637 pctx = ipv4_pdp_find(gtp, iph->saddr); 638 else 639 pctx = ipv4_pdp_find(gtp, iph->daddr); 640 641 if (!pctx) { 642 netdev_dbg(dev, "no PDP ctx found for %pI4, skip\n", 643 &iph->daddr); 644 return -ENOENT; 645 } 646 sk = pctx->sk; 647 netdev_dbg(dev, "found PDP context %p\n", pctx); 648 649 gtp_version = pctx->gtp_version; 650 tun_id = htonl(pctx->u.v1.o_tei); 651 daddr = pctx->peer_addr_ip4.s_addr; 652 saddr = inet_sk(sk)->inet_saddr; 653 tos = iph->tos; 654 df = iph->frag_off; 655 netdev_dbg(dev, "gtp -> IP src: %pI4 dst: %pI4\n", 656 &iph->saddr, &iph->daddr); 657 } 658 659 rt = ip4_route_output_gtp(&fl4, sk, daddr, saddr); 660 if (IS_ERR(rt)) { 661 netdev_dbg(dev, "no route to SSGN %pI4\n", &daddr); 662 dev->stats.tx_carrier_errors++; 663 goto err; 664 } 665 666 if (rt->dst.dev == dev) { 667 netdev_dbg(dev, "circular route to SSGN %pI4\n", &daddr); 668 dev->stats.collisions++; 669 goto err_rt; 670 } 671 672 skb_dst_drop(skb); 673 674 /* This is similar to tnl_update_pmtu(). */ 675 if (df) { 676 mtu = dst_mtu(&rt->dst) - dev->hard_header_len - 677 sizeof(struct iphdr) - sizeof(struct udphdr); 678 switch (gtp_version) { 679 case GTP_V0: 680 mtu -= sizeof(struct gtp0_header); 681 break; 682 case GTP_V1: 683 mtu -= sizeof(struct gtp1_header); 684 break; 685 } 686 } else { 687 mtu = dst_mtu(&rt->dst); 688 } 689 690 rt->dst.ops->update_pmtu(&rt->dst, NULL, skb, mtu, false); 691 692 if (!skb_is_gso(skb) && (df & htons(IP_DF)) && mtu < skb->len) { 693 netdev_dbg(dev, "packet too big, fragmentation needed"); 694 memset(IPCB(skb), 0, sizeof(*IPCB(skb))); 695 icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, 696 htonl(mtu)); 697 goto err_rt; 698 } 699 700 gtp_set_pktinfo_ipv4(pktinfo, sk, tos, rt, &fl4, dev); 701 702 if (unlikely(opts)) { 703 int err; 704 705 pktinfo->gtph_port = htons(GTP1U_PORT); 706 err = gtp1_push_control_header(skb, tun_id, opts, dev); 707 if (err) { 708 netdev_info(dev, "cntr pkt error %d", err); 709 goto err_rt; 710 } 711 return 0; 712 } 713 714 switch (gtp_version) { 715 case GTP_V0: 716 pktinfo->gtph_port = htons(GTP0_PORT); 717 gtp0_push_header(skb, pctx); 718 break; 719 case GTP_V1: 720 pktinfo->gtph_port = htons(GTP1U_PORT); 721 gtp1_push_header(skb, tun_id); 722 break; 723 } 724 725 return 0; 726 err_rt: 727 ip_rt_put(rt); 728 err: 729 return -EBADMSG; 730 } 731 732 static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev) 733 { 734 struct gtp_pktinfo pktinfo; 735 int err; 736 737 /* Ensure there is sufficient headroom. */ 738 if (skb_cow_head(skb, dev->needed_headroom)) 739 goto tx_err; 740 741 skb_reset_inner_headers(skb); 742 743 /* PDP context lookups in gtp_build_skb_*() need rcu read-side lock. */ 744 rcu_read_lock(); 745 err = gtp_build_skb_ip4(skb, dev, &pktinfo); 746 rcu_read_unlock(); 747 748 if (err < 0) 749 goto tx_err; 750 751 udp_tunnel_xmit_skb(pktinfo.rt, pktinfo.sk, skb, 752 pktinfo.fl4.saddr, 753 pktinfo.fl4.daddr, 754 pktinfo.tos, 755 ip4_dst_hoplimit(&pktinfo.rt->dst), 756 0, 757 pktinfo.gtph_port, 758 pktinfo.gtph_port, 759 true, 760 false); 761 762 return NETDEV_TX_OK; 763 tx_err: 764 dev->stats.tx_errors++; 765 dev_kfree_skb(skb); 766 return NETDEV_TX_OK; 767 } 768 769 static const struct net_device_ops gtp_netdev_ops = { 770 .ndo_init = gtp_dev_init, 771 .ndo_uninit = gtp_dev_uninit, 772 .ndo_start_xmit = gtp_dev_xmit, 773 .ndo_get_stats64 = dev_get_tstats64, 774 }; 775 776 static struct gtp_dev *gtp_find_flow_based_dev(struct net *net) 777 { 778 struct gtp_net *gn = net_generic(net, gtp_net_id); 779 struct gtp_dev *gtp; 780 781 list_for_each_entry(gtp, &gn->gtp_dev_list, list) { 782 if (gtp->collect_md) 783 return gtp; 784 } 785 786 return NULL; 787 } 788 789 static void gtp_link_setup(struct net_device *dev) 790 { 791 dev->netdev_ops = >p_netdev_ops; 792 dev->needs_free_netdev = true; 793 794 dev->hard_header_len = 0; 795 dev->addr_len = 0; 796 797 /* Zero header length. */ 798 dev->type = ARPHRD_NONE; 799 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 800 801 dev->priv_flags |= IFF_NO_QUEUE; 802 dev->features |= NETIF_F_LLTX; 803 netif_keep_dst(dev); 804 805 /* Assume largest header, ie. GTPv0. */ 806 dev->needed_headroom = LL_MAX_HEADER + 807 sizeof(struct iphdr) + 808 sizeof(struct udphdr) + 809 sizeof(struct gtp0_header); 810 } 811 812 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize); 813 static int gtp_encap_enable(struct gtp_dev *gtp, struct net_device *dev, struct nlattr *data[]); 814 815 static void gtp_destructor(struct net_device *dev) 816 { 817 struct gtp_dev *gtp = netdev_priv(dev); 818 819 kfree(gtp->addr_hash); 820 kfree(gtp->tid_hash); 821 } 822 823 static int gtp_newlink(struct net *src_net, struct net_device *dev, 824 struct nlattr *tb[], struct nlattr *data[], 825 struct netlink_ext_ack *extack) 826 { 827 struct gtp_dev *gtp; 828 struct gtp_net *gn; 829 int hashsize, err; 830 831 if (!data[IFLA_GTP_FD0] && !data[IFLA_GTP_FD1] && 832 !data[IFLA_GTP_COLLECT_METADATA]) 833 return -EINVAL; 834 835 gtp = netdev_priv(dev); 836 837 if (data[IFLA_GTP_COLLECT_METADATA]) { 838 if (data[IFLA_GTP_FD0]) { 839 netdev_dbg(dev, "LWT device does not support setting v0 socket"); 840 return -EINVAL; 841 } 842 if (gtp_find_flow_based_dev(src_net)) { 843 netdev_dbg(dev, "LWT device already exist"); 844 return -EBUSY; 845 } 846 gtp->collect_md = true; 847 } 848 849 if (!data[IFLA_GTP_PDP_HASHSIZE]) { 850 hashsize = 1024; 851 } else { 852 hashsize = nla_get_u32(data[IFLA_GTP_PDP_HASHSIZE]); 853 if (!hashsize) 854 hashsize = 1024; 855 } 856 857 err = gtp_hashtable_new(gtp, hashsize); 858 if (err < 0) 859 return err; 860 861 err = gtp_encap_enable(gtp, dev, data); 862 if (err < 0) 863 goto out_hashtable; 864 865 err = register_netdevice(dev); 866 if (err < 0) { 867 netdev_dbg(dev, "failed to register new netdev %d\n", err); 868 goto out_encap; 869 } 870 871 gn = net_generic(dev_net(dev), gtp_net_id); 872 list_add_rcu(>p->list, &gn->gtp_dev_list); 873 dev->priv_destructor = gtp_destructor; 874 875 netdev_dbg(dev, "registered new GTP interface %s\n", dev->name); 876 877 return 0; 878 879 out_encap: 880 gtp_encap_disable(gtp); 881 out_hashtable: 882 kfree(gtp->addr_hash); 883 kfree(gtp->tid_hash); 884 return err; 885 } 886 887 static void gtp_dellink(struct net_device *dev, struct list_head *head) 888 { 889 struct gtp_dev *gtp = netdev_priv(dev); 890 struct pdp_ctx *pctx; 891 int i; 892 893 for (i = 0; i < gtp->hash_size; i++) 894 hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], hlist_tid) 895 pdp_context_delete(pctx); 896 897 list_del_rcu(>p->list); 898 unregister_netdevice_queue(dev, head); 899 } 900 901 static const struct nla_policy gtp_policy[IFLA_GTP_MAX + 1] = { 902 [IFLA_GTP_FD0] = { .type = NLA_U32 }, 903 [IFLA_GTP_FD1] = { .type = NLA_U32 }, 904 [IFLA_GTP_PDP_HASHSIZE] = { .type = NLA_U32 }, 905 [IFLA_GTP_ROLE] = { .type = NLA_U32 }, 906 [IFLA_GTP_COLLECT_METADATA] = { .type = NLA_FLAG }, 907 }; 908 909 static int gtp_validate(struct nlattr *tb[], struct nlattr *data[], 910 struct netlink_ext_ack *extack) 911 { 912 if (!data) 913 return -EINVAL; 914 915 return 0; 916 } 917 918 static size_t gtp_get_size(const struct net_device *dev) 919 { 920 return nla_total_size(sizeof(__u32)); /* IFLA_GTP_PDP_HASHSIZE */ 921 } 922 923 static int gtp_fill_info(struct sk_buff *skb, const struct net_device *dev) 924 { 925 struct gtp_dev *gtp = netdev_priv(dev); 926 927 if (nla_put_u32(skb, IFLA_GTP_PDP_HASHSIZE, gtp->hash_size)) 928 goto nla_put_failure; 929 930 if (gtp->collect_md && nla_put_flag(skb, IFLA_GTP_COLLECT_METADATA)) 931 goto nla_put_failure; 932 933 return 0; 934 935 nla_put_failure: 936 return -EMSGSIZE; 937 } 938 939 static struct rtnl_link_ops gtp_link_ops __read_mostly = { 940 .kind = "gtp", 941 .maxtype = IFLA_GTP_MAX, 942 .policy = gtp_policy, 943 .priv_size = sizeof(struct gtp_dev), 944 .setup = gtp_link_setup, 945 .validate = gtp_validate, 946 .newlink = gtp_newlink, 947 .dellink = gtp_dellink, 948 .get_size = gtp_get_size, 949 .fill_info = gtp_fill_info, 950 }; 951 952 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize) 953 { 954 int i; 955 956 gtp->addr_hash = kmalloc_array(hsize, sizeof(struct hlist_head), 957 GFP_KERNEL | __GFP_NOWARN); 958 if (gtp->addr_hash == NULL) 959 return -ENOMEM; 960 961 gtp->tid_hash = kmalloc_array(hsize, sizeof(struct hlist_head), 962 GFP_KERNEL | __GFP_NOWARN); 963 if (gtp->tid_hash == NULL) 964 goto err1; 965 966 gtp->hash_size = hsize; 967 968 for (i = 0; i < hsize; i++) { 969 INIT_HLIST_HEAD(>p->addr_hash[i]); 970 INIT_HLIST_HEAD(>p->tid_hash[i]); 971 } 972 return 0; 973 err1: 974 kfree(gtp->addr_hash); 975 return -ENOMEM; 976 } 977 978 static int __gtp_encap_enable_socket(struct socket *sock, int type, 979 struct gtp_dev *gtp) 980 { 981 struct udp_tunnel_sock_cfg tuncfg = {NULL}; 982 struct sock *sk; 983 984 sk = sock->sk; 985 if (sk->sk_protocol != IPPROTO_UDP || 986 sk->sk_type != SOCK_DGRAM || 987 (sk->sk_family != AF_INET && sk->sk_family != AF_INET6)) { 988 pr_debug("socket not UDP\n"); 989 return -EINVAL; 990 } 991 992 lock_sock(sk); 993 if (sk->sk_user_data) { 994 release_sock(sock->sk); 995 return -EBUSY; 996 } 997 998 sock_hold(sk); 999 1000 tuncfg.sk_user_data = gtp; 1001 tuncfg.encap_type = type; 1002 tuncfg.encap_rcv = gtp_encap_recv; 1003 tuncfg.encap_destroy = gtp_encap_destroy; 1004 1005 setup_udp_tunnel_sock(sock_net(sock->sk), sock, &tuncfg); 1006 release_sock(sock->sk); 1007 return 0; 1008 } 1009 1010 static struct sock *gtp_encap_enable_socket(int fd, int type, 1011 struct gtp_dev *gtp) 1012 { 1013 struct socket *sock; 1014 int err; 1015 1016 pr_debug("enable gtp on %d, %d\n", fd, type); 1017 1018 sock = sockfd_lookup(fd, &err); 1019 if (!sock) { 1020 pr_debug("gtp socket fd=%d not found\n", fd); 1021 return NULL; 1022 } 1023 err = __gtp_encap_enable_socket(sock, type, gtp); 1024 sockfd_put(sock); 1025 if (err) 1026 return ERR_PTR(err); 1027 1028 return sock->sk; 1029 } 1030 1031 static struct socket *gtp_create_gtp_socket(struct gtp_dev *gtp, struct net_device *dev) 1032 { 1033 struct udp_port_cfg udp_conf; 1034 struct socket *sock; 1035 int err; 1036 1037 memset(&udp_conf, 0, sizeof(udp_conf)); 1038 udp_conf.family = AF_INET; 1039 udp_conf.local_ip.s_addr = htonl(INADDR_ANY); 1040 udp_conf.local_udp_port = htons(GTP1U_PORT); 1041 1042 err = udp_sock_create(dev_net(dev), &udp_conf, &sock); 1043 if (err < 0) { 1044 pr_debug("create gtp sock failed: %d\n", err); 1045 return ERR_PTR(err); 1046 } 1047 err = __gtp_encap_enable_socket(sock, UDP_ENCAP_GTP1U, gtp); 1048 if (err) { 1049 pr_debug("enable gtp sock encap failed: %d\n", err); 1050 udp_tunnel_sock_release(sock); 1051 return ERR_PTR(err); 1052 } 1053 pr_debug("create gtp sock done\n"); 1054 return sock; 1055 } 1056 1057 static int gtp_encap_enable(struct gtp_dev *gtp, struct net_device *dev, struct nlattr *data[]) 1058 { 1059 struct sock *sk1u = NULL; 1060 struct sock *sk0 = NULL; 1061 unsigned int role = GTP_ROLE_GGSN; 1062 1063 if (data[IFLA_GTP_FD0]) { 1064 u32 fd0 = nla_get_u32(data[IFLA_GTP_FD0]); 1065 1066 sk0 = gtp_encap_enable_socket(fd0, UDP_ENCAP_GTP0, gtp); 1067 if (IS_ERR(sk0)) 1068 return PTR_ERR(sk0); 1069 } 1070 1071 if (data[IFLA_GTP_FD1]) { 1072 u32 fd1 = nla_get_u32(data[IFLA_GTP_FD1]); 1073 1074 sk1u = gtp_encap_enable_socket(fd1, UDP_ENCAP_GTP1U, gtp); 1075 if (IS_ERR(sk1u)) { 1076 gtp_encap_disable_sock(sk0); 1077 return PTR_ERR(sk1u); 1078 } 1079 } 1080 1081 if (data[IFLA_GTP_COLLECT_METADATA]) { 1082 struct socket *sock; 1083 1084 if (!sk1u) { 1085 sock = gtp_create_gtp_socket(gtp, dev); 1086 if (IS_ERR(sock)) 1087 return PTR_ERR(sock); 1088 1089 gtp->collect_md_sock = sock; 1090 sk1u = sock->sk; 1091 } else { 1092 gtp->collect_md_sock = NULL; 1093 } 1094 } 1095 1096 if (data[IFLA_GTP_ROLE]) { 1097 role = nla_get_u32(data[IFLA_GTP_ROLE]); 1098 if (role > GTP_ROLE_SGSN) { 1099 gtp_encap_disable(gtp); 1100 return -EINVAL; 1101 } 1102 } 1103 1104 gtp->sk0 = sk0; 1105 gtp->sk1u = sk1u; 1106 gtp->role = role; 1107 1108 return 0; 1109 } 1110 1111 static struct gtp_dev *gtp_find_dev(struct net *src_net, struct nlattr *nla[]) 1112 { 1113 struct gtp_dev *gtp = NULL; 1114 struct net_device *dev; 1115 struct net *net; 1116 1117 /* Examine the link attributes and figure out which network namespace 1118 * we are talking about. 1119 */ 1120 if (nla[GTPA_NET_NS_FD]) 1121 net = get_net_ns_by_fd(nla_get_u32(nla[GTPA_NET_NS_FD])); 1122 else 1123 net = get_net(src_net); 1124 1125 if (IS_ERR(net)) 1126 return NULL; 1127 1128 /* Check if there's an existing gtpX device to configure */ 1129 dev = dev_get_by_index_rcu(net, nla_get_u32(nla[GTPA_LINK])); 1130 if (dev && dev->netdev_ops == >p_netdev_ops) 1131 gtp = netdev_priv(dev); 1132 1133 put_net(net); 1134 return gtp; 1135 } 1136 1137 static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info) 1138 { 1139 pctx->gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]); 1140 pctx->af = AF_INET; 1141 pctx->peer_addr_ip4.s_addr = 1142 nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]); 1143 pctx->ms_addr_ip4.s_addr = 1144 nla_get_be32(info->attrs[GTPA_MS_ADDRESS]); 1145 1146 switch (pctx->gtp_version) { 1147 case GTP_V0: 1148 /* According to TS 09.60, sections 7.5.1 and 7.5.2, the flow 1149 * label needs to be the same for uplink and downlink packets, 1150 * so let's annotate this. 1151 */ 1152 pctx->u.v0.tid = nla_get_u64(info->attrs[GTPA_TID]); 1153 pctx->u.v0.flow = nla_get_u16(info->attrs[GTPA_FLOW]); 1154 break; 1155 case GTP_V1: 1156 pctx->u.v1.i_tei = nla_get_u32(info->attrs[GTPA_I_TEI]); 1157 pctx->u.v1.o_tei = nla_get_u32(info->attrs[GTPA_O_TEI]); 1158 break; 1159 default: 1160 break; 1161 } 1162 } 1163 1164 static struct pdp_ctx *gtp_pdp_add(struct gtp_dev *gtp, struct sock *sk, 1165 struct genl_info *info) 1166 { 1167 struct pdp_ctx *pctx, *pctx_tid = NULL; 1168 struct net_device *dev = gtp->dev; 1169 u32 hash_ms, hash_tid = 0; 1170 unsigned int version; 1171 bool found = false; 1172 __be32 ms_addr; 1173 1174 ms_addr = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]); 1175 hash_ms = ipv4_hashfn(ms_addr) % gtp->hash_size; 1176 version = nla_get_u32(info->attrs[GTPA_VERSION]); 1177 1178 pctx = ipv4_pdp_find(gtp, ms_addr); 1179 if (pctx) 1180 found = true; 1181 if (version == GTP_V0) 1182 pctx_tid = gtp0_pdp_find(gtp, 1183 nla_get_u64(info->attrs[GTPA_TID])); 1184 else if (version == GTP_V1) 1185 pctx_tid = gtp1_pdp_find(gtp, 1186 nla_get_u32(info->attrs[GTPA_I_TEI])); 1187 if (pctx_tid) 1188 found = true; 1189 1190 if (found) { 1191 if (info->nlhdr->nlmsg_flags & NLM_F_EXCL) 1192 return ERR_PTR(-EEXIST); 1193 if (info->nlhdr->nlmsg_flags & NLM_F_REPLACE) 1194 return ERR_PTR(-EOPNOTSUPP); 1195 1196 if (pctx && pctx_tid) 1197 return ERR_PTR(-EEXIST); 1198 if (!pctx) 1199 pctx = pctx_tid; 1200 1201 ipv4_pdp_fill(pctx, info); 1202 1203 if (pctx->gtp_version == GTP_V0) 1204 netdev_dbg(dev, "GTPv0-U: update tunnel id = %llx (pdp %p)\n", 1205 pctx->u.v0.tid, pctx); 1206 else if (pctx->gtp_version == GTP_V1) 1207 netdev_dbg(dev, "GTPv1-U: update tunnel id = %x/%x (pdp %p)\n", 1208 pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx); 1209 1210 return pctx; 1211 1212 } 1213 1214 pctx = kmalloc(sizeof(*pctx), GFP_ATOMIC); 1215 if (pctx == NULL) 1216 return ERR_PTR(-ENOMEM); 1217 1218 sock_hold(sk); 1219 pctx->sk = sk; 1220 pctx->dev = gtp->dev; 1221 ipv4_pdp_fill(pctx, info); 1222 atomic_set(&pctx->tx_seq, 0); 1223 1224 switch (pctx->gtp_version) { 1225 case GTP_V0: 1226 /* TS 09.60: "The flow label identifies unambiguously a GTP 1227 * flow.". We use the tid for this instead, I cannot find a 1228 * situation in which this doesn't unambiguosly identify the 1229 * PDP context. 1230 */ 1231 hash_tid = gtp0_hashfn(pctx->u.v0.tid) % gtp->hash_size; 1232 break; 1233 case GTP_V1: 1234 hash_tid = gtp1u_hashfn(pctx->u.v1.i_tei) % gtp->hash_size; 1235 break; 1236 } 1237 1238 hlist_add_head_rcu(&pctx->hlist_addr, >p->addr_hash[hash_ms]); 1239 hlist_add_head_rcu(&pctx->hlist_tid, >p->tid_hash[hash_tid]); 1240 1241 switch (pctx->gtp_version) { 1242 case GTP_V0: 1243 netdev_dbg(dev, "GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n", 1244 pctx->u.v0.tid, &pctx->peer_addr_ip4, 1245 &pctx->ms_addr_ip4, pctx); 1246 break; 1247 case GTP_V1: 1248 netdev_dbg(dev, "GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n", 1249 pctx->u.v1.i_tei, pctx->u.v1.o_tei, 1250 &pctx->peer_addr_ip4, &pctx->ms_addr_ip4, pctx); 1251 break; 1252 } 1253 1254 return pctx; 1255 } 1256 1257 static void pdp_context_free(struct rcu_head *head) 1258 { 1259 struct pdp_ctx *pctx = container_of(head, struct pdp_ctx, rcu_head); 1260 1261 sock_put(pctx->sk); 1262 kfree(pctx); 1263 } 1264 1265 static void pdp_context_delete(struct pdp_ctx *pctx) 1266 { 1267 hlist_del_rcu(&pctx->hlist_tid); 1268 hlist_del_rcu(&pctx->hlist_addr); 1269 call_rcu(&pctx->rcu_head, pdp_context_free); 1270 } 1271 1272 static int gtp_tunnel_notify(struct pdp_ctx *pctx, u8 cmd, gfp_t allocation); 1273 1274 static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info) 1275 { 1276 unsigned int version; 1277 struct pdp_ctx *pctx; 1278 struct gtp_dev *gtp; 1279 struct sock *sk; 1280 int err; 1281 1282 if (!info->attrs[GTPA_VERSION] || 1283 !info->attrs[GTPA_LINK] || 1284 !info->attrs[GTPA_PEER_ADDRESS] || 1285 !info->attrs[GTPA_MS_ADDRESS]) 1286 return -EINVAL; 1287 1288 version = nla_get_u32(info->attrs[GTPA_VERSION]); 1289 1290 switch (version) { 1291 case GTP_V0: 1292 if (!info->attrs[GTPA_TID] || 1293 !info->attrs[GTPA_FLOW]) 1294 return -EINVAL; 1295 break; 1296 case GTP_V1: 1297 if (!info->attrs[GTPA_I_TEI] || 1298 !info->attrs[GTPA_O_TEI]) 1299 return -EINVAL; 1300 break; 1301 1302 default: 1303 return -EINVAL; 1304 } 1305 1306 rtnl_lock(); 1307 1308 gtp = gtp_find_dev(sock_net(skb->sk), info->attrs); 1309 if (!gtp) { 1310 err = -ENODEV; 1311 goto out_unlock; 1312 } 1313 1314 if (version == GTP_V0) 1315 sk = gtp->sk0; 1316 else if (version == GTP_V1) 1317 sk = gtp->sk1u; 1318 else 1319 sk = NULL; 1320 1321 if (!sk) { 1322 err = -ENODEV; 1323 goto out_unlock; 1324 } 1325 1326 pctx = gtp_pdp_add(gtp, sk, info); 1327 if (IS_ERR(pctx)) { 1328 err = PTR_ERR(pctx); 1329 } else { 1330 gtp_tunnel_notify(pctx, GTP_CMD_NEWPDP, GFP_KERNEL); 1331 err = 0; 1332 } 1333 1334 out_unlock: 1335 rtnl_unlock(); 1336 return err; 1337 } 1338 1339 static struct pdp_ctx *gtp_find_pdp_by_link(struct net *net, 1340 struct nlattr *nla[]) 1341 { 1342 struct gtp_dev *gtp; 1343 1344 gtp = gtp_find_dev(net, nla); 1345 if (!gtp) 1346 return ERR_PTR(-ENODEV); 1347 1348 if (nla[GTPA_MS_ADDRESS]) { 1349 __be32 ip = nla_get_be32(nla[GTPA_MS_ADDRESS]); 1350 1351 return ipv4_pdp_find(gtp, ip); 1352 } else if (nla[GTPA_VERSION]) { 1353 u32 gtp_version = nla_get_u32(nla[GTPA_VERSION]); 1354 1355 if (gtp_version == GTP_V0 && nla[GTPA_TID]) 1356 return gtp0_pdp_find(gtp, nla_get_u64(nla[GTPA_TID])); 1357 else if (gtp_version == GTP_V1 && nla[GTPA_I_TEI]) 1358 return gtp1_pdp_find(gtp, nla_get_u32(nla[GTPA_I_TEI])); 1359 } 1360 1361 return ERR_PTR(-EINVAL); 1362 } 1363 1364 static struct pdp_ctx *gtp_find_pdp(struct net *net, struct nlattr *nla[]) 1365 { 1366 struct pdp_ctx *pctx; 1367 1368 if (nla[GTPA_LINK]) 1369 pctx = gtp_find_pdp_by_link(net, nla); 1370 else 1371 pctx = ERR_PTR(-EINVAL); 1372 1373 if (!pctx) 1374 pctx = ERR_PTR(-ENOENT); 1375 1376 return pctx; 1377 } 1378 1379 static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info) 1380 { 1381 struct pdp_ctx *pctx; 1382 int err = 0; 1383 1384 if (!info->attrs[GTPA_VERSION]) 1385 return -EINVAL; 1386 1387 rcu_read_lock(); 1388 1389 pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs); 1390 if (IS_ERR(pctx)) { 1391 err = PTR_ERR(pctx); 1392 goto out_unlock; 1393 } 1394 1395 if (pctx->gtp_version == GTP_V0) 1396 netdev_dbg(pctx->dev, "GTPv0-U: deleting tunnel id = %llx (pdp %p)\n", 1397 pctx->u.v0.tid, pctx); 1398 else if (pctx->gtp_version == GTP_V1) 1399 netdev_dbg(pctx->dev, "GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n", 1400 pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx); 1401 1402 gtp_tunnel_notify(pctx, GTP_CMD_DELPDP, GFP_ATOMIC); 1403 pdp_context_delete(pctx); 1404 1405 out_unlock: 1406 rcu_read_unlock(); 1407 return err; 1408 } 1409 1410 static struct genl_family gtp_genl_family; 1411 1412 enum gtp_multicast_groups { 1413 GTP_GENL_MCGRP, 1414 }; 1415 1416 static const struct genl_multicast_group gtp_genl_mcgrps[] = { 1417 [GTP_GENL_MCGRP] = { .name = GTP_GENL_MCGRP_NAME }, 1418 }; 1419 1420 static int gtp_genl_fill_info(struct sk_buff *skb, u32 snd_portid, u32 snd_seq, 1421 int flags, u32 type, struct pdp_ctx *pctx) 1422 { 1423 void *genlh; 1424 1425 genlh = genlmsg_put(skb, snd_portid, snd_seq, >p_genl_family, flags, 1426 type); 1427 if (genlh == NULL) 1428 goto nlmsg_failure; 1429 1430 if (nla_put_u32(skb, GTPA_VERSION, pctx->gtp_version) || 1431 nla_put_u32(skb, GTPA_LINK, pctx->dev->ifindex) || 1432 nla_put_be32(skb, GTPA_PEER_ADDRESS, pctx->peer_addr_ip4.s_addr) || 1433 nla_put_be32(skb, GTPA_MS_ADDRESS, pctx->ms_addr_ip4.s_addr)) 1434 goto nla_put_failure; 1435 1436 switch (pctx->gtp_version) { 1437 case GTP_V0: 1438 if (nla_put_u64_64bit(skb, GTPA_TID, pctx->u.v0.tid, GTPA_PAD) || 1439 nla_put_u16(skb, GTPA_FLOW, pctx->u.v0.flow)) 1440 goto nla_put_failure; 1441 break; 1442 case GTP_V1: 1443 if (nla_put_u32(skb, GTPA_I_TEI, pctx->u.v1.i_tei) || 1444 nla_put_u32(skb, GTPA_O_TEI, pctx->u.v1.o_tei)) 1445 goto nla_put_failure; 1446 break; 1447 } 1448 genlmsg_end(skb, genlh); 1449 return 0; 1450 1451 nlmsg_failure: 1452 nla_put_failure: 1453 genlmsg_cancel(skb, genlh); 1454 return -EMSGSIZE; 1455 } 1456 1457 static int gtp_tunnel_notify(struct pdp_ctx *pctx, u8 cmd, gfp_t allocation) 1458 { 1459 struct sk_buff *msg; 1460 int ret; 1461 1462 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, allocation); 1463 if (!msg) 1464 return -ENOMEM; 1465 1466 ret = gtp_genl_fill_info(msg, 0, 0, 0, cmd, pctx); 1467 if (ret < 0) { 1468 nlmsg_free(msg); 1469 return ret; 1470 } 1471 1472 ret = genlmsg_multicast_netns(>p_genl_family, dev_net(pctx->dev), msg, 1473 0, GTP_GENL_MCGRP, GFP_ATOMIC); 1474 return ret; 1475 } 1476 1477 static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info) 1478 { 1479 struct pdp_ctx *pctx = NULL; 1480 struct sk_buff *skb2; 1481 int err; 1482 1483 if (!info->attrs[GTPA_VERSION]) 1484 return -EINVAL; 1485 1486 rcu_read_lock(); 1487 1488 pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs); 1489 if (IS_ERR(pctx)) { 1490 err = PTR_ERR(pctx); 1491 goto err_unlock; 1492 } 1493 1494 skb2 = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC); 1495 if (skb2 == NULL) { 1496 err = -ENOMEM; 1497 goto err_unlock; 1498 } 1499 1500 err = gtp_genl_fill_info(skb2, NETLINK_CB(skb).portid, info->snd_seq, 1501 0, info->nlhdr->nlmsg_type, pctx); 1502 if (err < 0) 1503 goto err_unlock_free; 1504 1505 rcu_read_unlock(); 1506 return genlmsg_unicast(genl_info_net(info), skb2, info->snd_portid); 1507 1508 err_unlock_free: 1509 kfree_skb(skb2); 1510 err_unlock: 1511 rcu_read_unlock(); 1512 return err; 1513 } 1514 1515 static int gtp_genl_dump_pdp(struct sk_buff *skb, 1516 struct netlink_callback *cb) 1517 { 1518 struct gtp_dev *last_gtp = (struct gtp_dev *)cb->args[2], *gtp; 1519 int i, j, bucket = cb->args[0], skip = cb->args[1]; 1520 struct net *net = sock_net(skb->sk); 1521 struct pdp_ctx *pctx; 1522 struct gtp_net *gn; 1523 1524 gn = net_generic(net, gtp_net_id); 1525 1526 if (cb->args[4]) 1527 return 0; 1528 1529 rcu_read_lock(); 1530 list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) { 1531 if (last_gtp && last_gtp != gtp) 1532 continue; 1533 else 1534 last_gtp = NULL; 1535 1536 for (i = bucket; i < gtp->hash_size; i++) { 1537 j = 0; 1538 hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], 1539 hlist_tid) { 1540 if (j >= skip && 1541 gtp_genl_fill_info(skb, 1542 NETLINK_CB(cb->skb).portid, 1543 cb->nlh->nlmsg_seq, 1544 NLM_F_MULTI, 1545 cb->nlh->nlmsg_type, pctx)) { 1546 cb->args[0] = i; 1547 cb->args[1] = j; 1548 cb->args[2] = (unsigned long)gtp; 1549 goto out; 1550 } 1551 j++; 1552 } 1553 skip = 0; 1554 } 1555 bucket = 0; 1556 } 1557 cb->args[4] = 1; 1558 out: 1559 rcu_read_unlock(); 1560 return skb->len; 1561 } 1562 1563 static const struct nla_policy gtp_genl_policy[GTPA_MAX + 1] = { 1564 [GTPA_LINK] = { .type = NLA_U32, }, 1565 [GTPA_VERSION] = { .type = NLA_U32, }, 1566 [GTPA_TID] = { .type = NLA_U64, }, 1567 [GTPA_PEER_ADDRESS] = { .type = NLA_U32, }, 1568 [GTPA_MS_ADDRESS] = { .type = NLA_U32, }, 1569 [GTPA_FLOW] = { .type = NLA_U16, }, 1570 [GTPA_NET_NS_FD] = { .type = NLA_U32, }, 1571 [GTPA_I_TEI] = { .type = NLA_U32, }, 1572 [GTPA_O_TEI] = { .type = NLA_U32, }, 1573 }; 1574 1575 static const struct genl_small_ops gtp_genl_ops[] = { 1576 { 1577 .cmd = GTP_CMD_NEWPDP, 1578 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, 1579 .doit = gtp_genl_new_pdp, 1580 .flags = GENL_ADMIN_PERM, 1581 }, 1582 { 1583 .cmd = GTP_CMD_DELPDP, 1584 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, 1585 .doit = gtp_genl_del_pdp, 1586 .flags = GENL_ADMIN_PERM, 1587 }, 1588 { 1589 .cmd = GTP_CMD_GETPDP, 1590 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, 1591 .doit = gtp_genl_get_pdp, 1592 .dumpit = gtp_genl_dump_pdp, 1593 .flags = GENL_ADMIN_PERM, 1594 }, 1595 }; 1596 1597 static struct genl_family gtp_genl_family __ro_after_init = { 1598 .name = "gtp", 1599 .version = 0, 1600 .hdrsize = 0, 1601 .maxattr = GTPA_MAX, 1602 .policy = gtp_genl_policy, 1603 .netnsok = true, 1604 .module = THIS_MODULE, 1605 .small_ops = gtp_genl_ops, 1606 .n_small_ops = ARRAY_SIZE(gtp_genl_ops), 1607 .mcgrps = gtp_genl_mcgrps, 1608 .n_mcgrps = ARRAY_SIZE(gtp_genl_mcgrps), 1609 }; 1610 1611 static int __net_init gtp_net_init(struct net *net) 1612 { 1613 struct gtp_net *gn = net_generic(net, gtp_net_id); 1614 1615 INIT_LIST_HEAD(&gn->gtp_dev_list); 1616 return 0; 1617 } 1618 1619 static void __net_exit gtp_net_exit(struct net *net) 1620 { 1621 struct gtp_net *gn = net_generic(net, gtp_net_id); 1622 struct gtp_dev *gtp; 1623 LIST_HEAD(list); 1624 1625 rtnl_lock(); 1626 list_for_each_entry(gtp, &gn->gtp_dev_list, list) 1627 gtp_dellink(gtp->dev, &list); 1628 1629 unregister_netdevice_many(&list); 1630 rtnl_unlock(); 1631 } 1632 1633 static struct pernet_operations gtp_net_ops = { 1634 .init = gtp_net_init, 1635 .exit = gtp_net_exit, 1636 .id = >p_net_id, 1637 .size = sizeof(struct gtp_net), 1638 }; 1639 1640 static int __init gtp_init(void) 1641 { 1642 int err; 1643 1644 get_random_bytes(>p_h_initval, sizeof(gtp_h_initval)); 1645 1646 err = rtnl_link_register(>p_link_ops); 1647 if (err < 0) 1648 goto error_out; 1649 1650 err = genl_register_family(>p_genl_family); 1651 if (err < 0) 1652 goto unreg_rtnl_link; 1653 1654 err = register_pernet_subsys(>p_net_ops); 1655 if (err < 0) 1656 goto unreg_genl_family; 1657 1658 pr_info("GTP module loaded (pdp ctx size %zd bytes) with tnl-md support\n", 1659 sizeof(struct pdp_ctx)); 1660 return 0; 1661 1662 unreg_genl_family: 1663 genl_unregister_family(>p_genl_family); 1664 unreg_rtnl_link: 1665 rtnl_link_unregister(>p_link_ops); 1666 error_out: 1667 pr_err("error loading GTP module loaded\n"); 1668 return err; 1669 } 1670 late_initcall(gtp_init); 1671 1672 static void __exit gtp_fini(void) 1673 { 1674 genl_unregister_family(>p_genl_family); 1675 rtnl_link_unregister(>p_link_ops); 1676 unregister_pernet_subsys(>p_net_ops); 1677 1678 pr_info("GTP module unloaded\n"); 1679 } 1680 module_exit(gtp_fini); 1681 1682 MODULE_LICENSE("GPL"); 1683 MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>"); 1684 MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic"); 1685 MODULE_ALIAS_RTNL_LINK("gtp"); 1686 MODULE_ALIAS_GENL_FAMILY("gtp"); 1687