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/ipv6.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. */
  37struct 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	union {
  55		struct in_addr	addr;
  56		struct in6_addr	addr6;
  57	} ms;
  58	union {
  59		struct in_addr	addr;
  60		struct in6_addr	addr6;
  61	} peer;
  62
  63	struct sock		*sk;
  64	struct net_device       *dev;
  65
  66	atomic_t		tx_seq;
  67	struct rcu_head		rcu_head;
  68};
  69
  70/* One instance of the GTP device. */
  71struct gtp_dev {
  72	struct list_head	list;
  73
  74	struct sock		*sk0;
  75	struct sock		*sk1u;
  76	u8			sk_created;
  77
  78	struct net_device	*dev;
  79	struct net		*net;
  80
  81	unsigned int		role;
  82	unsigned int		hash_size;
  83	struct hlist_head	*tid_hash;
  84	struct hlist_head	*addr_hash;
  85
  86	u8			restart_count;
  87};
  88
  89struct echo_info {
  90	u16			af;
  91	u8			gtp_version;
  92
  93	union {
  94		struct in_addr	addr;
  95	} ms;
  96	union {
  97		struct in_addr	addr;
  98	} peer;
  99};
 100
 101static unsigned int gtp_net_id __read_mostly;
 102
 103struct gtp_net {
 104	struct list_head gtp_dev_list;
 105};
 106
 107static u32 gtp_h_initval;
 108
 109static struct genl_family gtp_genl_family;
 110
 111enum gtp_multicast_groups {
 112	GTP_GENL_MCGRP,
 113};
 114
 115static const struct genl_multicast_group gtp_genl_mcgrps[] = {
 116	[GTP_GENL_MCGRP] = { .name = GTP_GENL_MCGRP_NAME },
 117};
 118
 119static void pdp_context_delete(struct pdp_ctx *pctx);
 120
 121static inline u32 gtp0_hashfn(u64 tid)
 122{
 123	u32 *tid32 = (u32 *) &tid;
 124	return jhash_2words(tid32[0], tid32[1], gtp_h_initval);
 125}
 126
 127static inline u32 gtp1u_hashfn(u32 tid)
 128{
 129	return jhash_1word(tid, gtp_h_initval);
 130}
 131
 132static inline u32 ipv4_hashfn(__be32 ip)
 133{
 134	return jhash_1word((__force u32)ip, gtp_h_initval);
 135}
 136
 137static u32 ipv6_hashfn(const struct in6_addr *ip6)
 138{
 139	return jhash_2words((__force u32)ip6->s6_addr32[0],
 140			    (__force u32)ip6->s6_addr32[1], gtp_h_initval);
 141}
 142
 143/* Resolve a PDP context structure based on the 64bit TID. */
 144static struct pdp_ctx *gtp0_pdp_find(struct gtp_dev *gtp, u64 tid, u16 family)
 145{
 146	struct hlist_head *head;
 147	struct pdp_ctx *pdp;
 148
 149	head = &gtp->tid_hash[gtp0_hashfn(tid) % gtp->hash_size];
 150
 151	hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
 152		if (pdp->af == family &&
 153		    pdp->gtp_version == GTP_V0 &&
 154		    pdp->u.v0.tid == tid)
 155			return pdp;
 156	}
 157	return NULL;
 158}
 159
 160/* Resolve a PDP context structure based on the 32bit TEI. */
 161static struct pdp_ctx *gtp1_pdp_find(struct gtp_dev *gtp, u32 tid, u16 family)
 162{
 163	struct hlist_head *head;
 164	struct pdp_ctx *pdp;
 165
 166	head = &gtp->tid_hash[gtp1u_hashfn(tid) % gtp->hash_size];
 167
 168	hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
 169		if (pdp->af == family &&
 170		    pdp->gtp_version == GTP_V1 &&
 171		    pdp->u.v1.i_tei == tid)
 172			return pdp;
 173	}
 174	return NULL;
 175}
 176
 177/* Resolve a PDP context based on IPv4 address of MS. */
 178static struct pdp_ctx *ipv4_pdp_find(struct gtp_dev *gtp, __be32 ms_addr)
 179{
 180	struct hlist_head *head;
 181	struct pdp_ctx *pdp;
 182
 183	head = &gtp->addr_hash[ipv4_hashfn(ms_addr) % gtp->hash_size];
 184
 185	hlist_for_each_entry_rcu(pdp, head, hlist_addr) {
 186		if (pdp->af == AF_INET &&
 187		    pdp->ms.addr.s_addr == ms_addr)
 188			return pdp;
 189	}
 190
 191	return NULL;
 192}
 193
 194/* 3GPP TS 29.060: PDN Connection: the association between a MS represented by
 195 * [...] one IPv6 *prefix* and a PDN represented by an APN.
 196 *
 197 * Then, 3GPP TS 29.061, Section 11.2.1.3 says: The size of the prefix shall be
 198 * according to the maximum prefix length for a global IPv6 address as
 199 * specified in the IPv6 Addressing Architecture, see RFC 4291.
 200 *
 201 * Finally, RFC 4291 section 2.5.4 states: All Global Unicast addresses other
 202 * than those that start with binary 000 have a 64-bit interface ID field
 203 * (i.e., n + m = 64).
 204 */
 205static bool ipv6_pdp_addr_equal(const struct in6_addr *a,
 206				const struct in6_addr *b)
 207{
 208	return a->s6_addr32[0] == b->s6_addr32[0] &&
 209	       a->s6_addr32[1] == b->s6_addr32[1];
 210}
 211
 212static struct pdp_ctx *ipv6_pdp_find(struct gtp_dev *gtp,
 213				     const struct in6_addr *ms_addr)
 214{
 215	struct hlist_head *head;
 216	struct pdp_ctx *pdp;
 217
 218	head = &gtp->addr_hash[ipv6_hashfn(ms_addr) % gtp->hash_size];
 219
 220	hlist_for_each_entry_rcu(pdp, head, hlist_addr) {
 221		if (pdp->af == AF_INET6 &&
 222		    ipv6_pdp_addr_equal(&pdp->ms.addr6, ms_addr))
 223			return pdp;
 224	}
 225
 226	return NULL;
 227}
 228
 229static bool gtp_check_ms_ipv4(struct sk_buff *skb, struct pdp_ctx *pctx,
 230				  unsigned int hdrlen, unsigned int role)
 231{
 232	struct iphdr *iph;
 233
 234	if (!pskb_may_pull(skb, hdrlen + sizeof(struct iphdr)))
 235		return false;
 236
 237	iph = (struct iphdr *)(skb->data + hdrlen);
 238
 239	if (role == GTP_ROLE_SGSN)
 240		return iph->daddr == pctx->ms.addr.s_addr;
 241	else
 242		return iph->saddr == pctx->ms.addr.s_addr;
 243}
 244
 245static bool gtp_check_ms_ipv6(struct sk_buff *skb, struct pdp_ctx *pctx,
 246			      unsigned int hdrlen, unsigned int role)
 247{
 248	struct ipv6hdr *ip6h;
 249	int ret;
 250
 251	if (!pskb_may_pull(skb, hdrlen + sizeof(struct ipv6hdr)))
 252		return false;
 253
 254	ip6h = (struct ipv6hdr *)(skb->data + hdrlen);
 255
 256	if ((ipv6_addr_type(&ip6h->saddr) & IPV6_ADDR_LINKLOCAL) ||
 257	    (ipv6_addr_type(&ip6h->daddr) & IPV6_ADDR_LINKLOCAL))
 258		return false;
 259
 260	if (role == GTP_ROLE_SGSN) {
 261		ret = ipv6_pdp_addr_equal(&ip6h->daddr, &pctx->ms.addr6);
 262	} else {
 263		ret = ipv6_pdp_addr_equal(&ip6h->saddr, &pctx->ms.addr6);
 264	}
 265
 266	return ret;
 267}
 268
 269/* Check if the inner IP address in this packet is assigned to any
 270 * existing mobile subscriber.
 271 */
 272static bool gtp_check_ms(struct sk_buff *skb, struct pdp_ctx *pctx,
 273			 unsigned int hdrlen, unsigned int role,
 274			 __u16 inner_proto)
 275{
 276	switch (inner_proto) {
 277	case ETH_P_IP:
 278		return gtp_check_ms_ipv4(skb, pctx, hdrlen, role);
 279	case ETH_P_IPV6:
 280		return gtp_check_ms_ipv6(skb, pctx, hdrlen, role);
 281	}
 282	return false;
 283}
 284
 285static int gtp_inner_proto(struct sk_buff *skb, unsigned int hdrlen,
 286			   __u16 *inner_proto)
 287{
 288	__u8 *ip_version, _ip_version;
 289
 290	ip_version = skb_header_pointer(skb, hdrlen, sizeof(*ip_version),
 291					&_ip_version);
 292	if (!ip_version)
 293		return -1;
 294
 295	switch (*ip_version & 0xf0) {
 296	case 0x40:
 297		*inner_proto = ETH_P_IP;
 298		break;
 299	case 0x60:
 300		*inner_proto = ETH_P_IPV6;
 301		break;
 302	default:
 303		return -1;
 304	}
 305
 306	return 0;
 307}
 308
 309static int gtp_rx(struct pdp_ctx *pctx, struct sk_buff *skb,
 310		  unsigned int hdrlen, unsigned int role, __u16 inner_proto)
 311{
 312	if (!gtp_check_ms(skb, pctx, hdrlen, role, inner_proto)) {
 
 
 313		netdev_dbg(pctx->dev, "No PDP ctx for this MS\n");
 314		return 1;
 315	}
 316
 317	/* Get rid of the GTP + UDP headers. */
 318	if (iptunnel_pull_header(skb, hdrlen, htons(inner_proto),
 319			 !net_eq(sock_net(pctx->sk), dev_net(pctx->dev)))) {
 320		pctx->dev->stats.rx_length_errors++;
 321		goto err;
 322	}
 323
 324	netdev_dbg(pctx->dev, "forwarding packet from GGSN to uplink\n");
 325
 326	/* Now that the UDP and the GTP header have been removed, set up the
 327	 * new network header. This is required by the upper layer to
 328	 * calculate the transport header.
 329	 */
 330	skb_reset_network_header(skb);
 331	skb_reset_mac_header(skb);
 332
 333	skb->dev = pctx->dev;
 334
 335	dev_sw_netstats_rx_add(pctx->dev, skb->len);
 336
 337	__netif_rx(skb);
 338	return 0;
 339
 340err:
 341	pctx->dev->stats.rx_dropped++;
 342	return -1;
 343}
 344
 345static struct rtable *ip4_route_output_gtp(struct flowi4 *fl4,
 346					   const struct sock *sk,
 347					   __be32 daddr, __be32 saddr)
 348{
 349	memset(fl4, 0, sizeof(*fl4));
 350	fl4->flowi4_oif		= sk->sk_bound_dev_if;
 351	fl4->daddr		= daddr;
 352	fl4->saddr		= saddr;
 353	fl4->flowi4_tos		= ip_sock_rt_tos(sk);
 354	fl4->flowi4_scope	= ip_sock_rt_scope(sk);
 355	fl4->flowi4_proto	= sk->sk_protocol;
 356
 357	return ip_route_output_key(sock_net(sk), fl4);
 358}
 359
 360static struct rt6_info *ip6_route_output_gtp(struct net *net,
 361					     struct flowi6 *fl6,
 362					     const struct sock *sk,
 363					     const struct in6_addr *daddr,
 364					     struct in6_addr *saddr)
 365{
 366	struct dst_entry *dst;
 367
 368	memset(fl6, 0, sizeof(*fl6));
 369	fl6->flowi6_oif		= sk->sk_bound_dev_if;
 370	fl6->daddr		= *daddr;
 371	fl6->saddr		= *saddr;
 372	fl6->flowi6_proto	= sk->sk_protocol;
 373
 374	dst = ipv6_stub->ipv6_dst_lookup_flow(net, sk, fl6, NULL);
 375	if (IS_ERR(dst))
 376		return ERR_PTR(-ENETUNREACH);
 377
 378	return (struct rt6_info *)dst;
 379}
 380
 381/* GSM TS 09.60. 7.3
 382 * In all Path Management messages:
 383 * - TID: is not used and shall be set to 0.
 384 * - Flow Label is not used and shall be set to 0
 385 * In signalling messages:
 386 * - number: this field is not yet used in signalling messages.
 387 *   It shall be set to 255 by the sender and shall be ignored
 388 *   by the receiver
 389 * Returns true if the echo req was correct, false otherwise.
 390 */
 391static bool gtp0_validate_echo_hdr(struct gtp0_header *gtp0)
 392{
 393	return !(gtp0->tid || (gtp0->flags ^ 0x1e) ||
 394		gtp0->number != 0xff || gtp0->flow);
 395}
 396
 397/* msg_type has to be GTP_ECHO_REQ or GTP_ECHO_RSP */
 398static void gtp0_build_echo_msg(struct gtp0_header *hdr, __u8 msg_type)
 399{
 400	int len_pkt, len_hdr;
 401
 402	hdr->flags = 0x1e; /* v0, GTP-non-prime. */
 403	hdr->type = msg_type;
 404	/* GSM TS 09.60. 7.3 In all Path Management Flow Label and TID
 405	 * are not used and shall be set to 0.
 406	 */
 407	hdr->flow = 0;
 408	hdr->tid = 0;
 409	hdr->number = 0xff;
 410	hdr->spare[0] = 0xff;
 411	hdr->spare[1] = 0xff;
 412	hdr->spare[2] = 0xff;
 413
 414	len_pkt = sizeof(struct gtp0_packet);
 415	len_hdr = sizeof(struct gtp0_header);
 416
 417	if (msg_type == GTP_ECHO_RSP)
 418		hdr->length = htons(len_pkt - len_hdr);
 419	else
 420		hdr->length = 0;
 421}
 422
 423static int gtp0_send_echo_resp_ip(struct gtp_dev *gtp, struct sk_buff *skb)
 424{
 425	struct iphdr *iph = ip_hdr(skb);
 426	struct flowi4 fl4;
 427	struct rtable *rt;
 428
 429	/* find route to the sender,
 430	 * src address becomes dst address and vice versa.
 431	 */
 432	rt = ip4_route_output_gtp(&fl4, gtp->sk0, iph->saddr, iph->daddr);
 433	if (IS_ERR(rt)) {
 434		netdev_dbg(gtp->dev, "no route for echo response from %pI4\n",
 435			   &iph->saddr);
 436		return -1;
 437	}
 438
 439	udp_tunnel_xmit_skb(rt, gtp->sk0, skb,
 440			    fl4.saddr, fl4.daddr,
 441			    iph->tos,
 442			    ip4_dst_hoplimit(&rt->dst),
 443			    0,
 444			    htons(GTP0_PORT), htons(GTP0_PORT),
 445			    !net_eq(sock_net(gtp->sk1u),
 446				    dev_net(gtp->dev)),
 447			    false);
 448
 
 449	return 0;
 450}
 451
 452static int gtp0_send_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb)
 453{
 454	struct gtp0_packet *gtp_pkt;
 455	struct gtp0_header *gtp0;
 456	__be16 seq;
 457
 458	gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr));
 459
 460	if (!gtp0_validate_echo_hdr(gtp0))
 461		return -1;
 462
 463	seq = gtp0->seq;
 464
 465	/* pull GTP and UDP headers */
 466	skb_pull_data(skb, sizeof(struct gtp0_header) + sizeof(struct udphdr));
 467
 468	gtp_pkt = skb_push(skb, sizeof(struct gtp0_packet));
 469	memset(gtp_pkt, 0, sizeof(struct gtp0_packet));
 470
 471	gtp0_build_echo_msg(&gtp_pkt->gtp0_h, GTP_ECHO_RSP);
 472
 473	/* GSM TS 09.60. 7.3 The Sequence Number in a signalling response
 474	 * message shall be copied from the signalling request message
 475	 * that the GSN is replying to.
 476	 */
 477	gtp_pkt->gtp0_h.seq = seq;
 478
 479	gtp_pkt->ie.tag = GTPIE_RECOVERY;
 480	gtp_pkt->ie.val = gtp->restart_count;
 481
 482	switch (gtp->sk0->sk_family) {
 483	case AF_INET:
 484		if (gtp0_send_echo_resp_ip(gtp, skb) < 0)
 485			return -1;
 486		break;
 487	case AF_INET6:
 488		return -1;
 489	}
 490
 491	return 0;
 492}
 493
 494static int gtp_genl_fill_echo(struct sk_buff *skb, u32 snd_portid, u32 snd_seq,
 495			      int flags, u32 type, struct echo_info echo)
 496{
 497	void *genlh;
 498
 499	genlh = genlmsg_put(skb, snd_portid, snd_seq, &gtp_genl_family, flags,
 500			    type);
 501	if (!genlh)
 502		goto failure;
 503
 504	if (nla_put_u32(skb, GTPA_VERSION, echo.gtp_version) ||
 505	    nla_put_be32(skb, GTPA_PEER_ADDRESS, echo.peer.addr.s_addr) ||
 506	    nla_put_be32(skb, GTPA_MS_ADDRESS, echo.ms.addr.s_addr))
 507		goto failure;
 508
 509	genlmsg_end(skb, genlh);
 510	return 0;
 511
 512failure:
 513	genlmsg_cancel(skb, genlh);
 514	return -EMSGSIZE;
 515}
 516
 517static void gtp0_handle_echo_resp_ip(struct sk_buff *skb, struct echo_info *echo)
 518{
 519	struct iphdr *iph = ip_hdr(skb);
 520
 521	echo->ms.addr.s_addr = iph->daddr;
 522	echo->peer.addr.s_addr = iph->saddr;
 523	echo->gtp_version = GTP_V0;
 524}
 525
 526static int gtp0_handle_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb)
 527{
 528	struct gtp0_header *gtp0;
 529	struct echo_info echo;
 530	struct sk_buff *msg;
 531	int ret;
 532
 533	gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr));
 534
 535	if (!gtp0_validate_echo_hdr(gtp0))
 536		return -1;
 537
 538	switch (gtp->sk0->sk_family) {
 539	case AF_INET:
 540		gtp0_handle_echo_resp_ip(skb, &echo);
 541		break;
 542	case AF_INET6:
 543		return -1;
 544	}
 545
 546	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
 547	if (!msg)
 548		return -ENOMEM;
 549
 550	ret = gtp_genl_fill_echo(msg, 0, 0, 0, GTP_CMD_ECHOREQ, echo);
 551	if (ret < 0) {
 552		nlmsg_free(msg);
 553		return ret;
 554	}
 555
 556	return genlmsg_multicast_netns(&gtp_genl_family, dev_net(gtp->dev),
 557				       msg, 0, GTP_GENL_MCGRP, GFP_ATOMIC);
 558}
 559
 560static int gtp_proto_to_family(__u16 proto)
 561{
 562	switch (proto) {
 563	case ETH_P_IP:
 564		return AF_INET;
 565	case ETH_P_IPV6:
 566		return AF_INET6;
 567	default:
 568		WARN_ON_ONCE(1);
 569		break;
 570	}
 571
 572	return AF_UNSPEC;
 573}
 574
 575/* 1 means pass up to the stack, -1 means drop and 0 means decapsulated. */
 576static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb)
 577{
 578	unsigned int hdrlen = sizeof(struct udphdr) +
 579			      sizeof(struct gtp0_header);
 580	struct gtp0_header *gtp0;
 581	struct pdp_ctx *pctx;
 582	__u16 inner_proto;
 583
 584	if (!pskb_may_pull(skb, hdrlen))
 585		return -1;
 586
 587	gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr));
 588
 589	if ((gtp0->flags >> 5) != GTP_V0)
 590		return 1;
 591
 592	/* If the sockets were created in kernel, it means that
 593	 * there is no daemon running in userspace which would
 594	 * handle echo request.
 595	 */
 596	if (gtp0->type == GTP_ECHO_REQ && gtp->sk_created)
 597		return gtp0_send_echo_resp(gtp, skb);
 598
 599	if (gtp0->type == GTP_ECHO_RSP && gtp->sk_created)
 600		return gtp0_handle_echo_resp(gtp, skb);
 601
 602	if (gtp0->type != GTP_TPDU)
 603		return 1;
 604
 605	if (gtp_inner_proto(skb, hdrlen, &inner_proto) < 0) {
 606		netdev_dbg(gtp->dev, "GTP packet does not encapsulate an IP packet\n");
 607		return -1;
 608	}
 609
 610	pctx = gtp0_pdp_find(gtp, be64_to_cpu(gtp0->tid),
 611			     gtp_proto_to_family(inner_proto));
 612	if (!pctx) {
 613		netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
 614		return 1;
 615	}
 616
 617	return gtp_rx(pctx, skb, hdrlen, gtp->role, inner_proto);
 618}
 619
 620/* msg_type has to be GTP_ECHO_REQ or GTP_ECHO_RSP */
 621static void gtp1u_build_echo_msg(struct gtp1_header_long *hdr, __u8 msg_type)
 622{
 623	int len_pkt, len_hdr;
 624
 625	/* S flag must be set to 1 */
 626	hdr->flags = 0x32; /* v1, GTP-non-prime. */
 627	hdr->type = msg_type;
 628	/* 3GPP TS 29.281 5.1 - TEID has to be set to 0 */
 629	hdr->tid = 0;
 630
 631	/* seq, npdu and next should be counted to the length of the GTP packet
 632	 * that's why szie of gtp1_header should be subtracted,
 633	 * not size of gtp1_header_long.
 634	 */
 635
 636	len_hdr = sizeof(struct gtp1_header);
 637
 638	if (msg_type == GTP_ECHO_RSP) {
 639		len_pkt = sizeof(struct gtp1u_packet);
 640		hdr->length = htons(len_pkt - len_hdr);
 641	} else {
 642		/* GTP_ECHO_REQ does not carry GTP Information Element,
 643		 * the why gtp1_header_long is used here.
 644		 */
 645		len_pkt = sizeof(struct gtp1_header_long);
 646		hdr->length = htons(len_pkt - len_hdr);
 647	}
 648}
 649
 650static int gtp1u_send_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb)
 651{
 652	struct gtp1_header_long *gtp1u;
 653	struct gtp1u_packet *gtp_pkt;
 654	struct rtable *rt;
 655	struct flowi4 fl4;
 656	struct iphdr *iph;
 657
 658	gtp1u = (struct gtp1_header_long *)(skb->data + sizeof(struct udphdr));
 659
 660	/* 3GPP TS 29.281 5.1 - For the Echo Request, Echo Response,
 661	 * Error Indication and Supported Extension Headers Notification
 662	 * messages, the S flag shall be set to 1 and TEID shall be set to 0.
 663	 */
 664	if (!(gtp1u->flags & GTP1_F_SEQ) || gtp1u->tid)
 665		return -1;
 666
 667	/* pull GTP and UDP headers */
 668	skb_pull_data(skb,
 669		      sizeof(struct gtp1_header_long) + sizeof(struct udphdr));
 670
 671	gtp_pkt = skb_push(skb, sizeof(struct gtp1u_packet));
 672	memset(gtp_pkt, 0, sizeof(struct gtp1u_packet));
 673
 674	gtp1u_build_echo_msg(&gtp_pkt->gtp1u_h, GTP_ECHO_RSP);
 675
 676	/* 3GPP TS 29.281 7.7.2 - The Restart Counter value in the
 677	 * Recovery information element shall not be used, i.e. it shall
 678	 * be set to zero by the sender and shall be ignored by the receiver.
 679	 * The Recovery information element is mandatory due to backwards
 680	 * compatibility reasons.
 681	 */
 682	gtp_pkt->ie.tag = GTPIE_RECOVERY;
 683	gtp_pkt->ie.val = 0;
 684
 685	iph = ip_hdr(skb);
 686
 687	/* find route to the sender,
 688	 * src address becomes dst address and vice versa.
 689	 */
 690	rt = ip4_route_output_gtp(&fl4, gtp->sk1u, iph->saddr, iph->daddr);
 691	if (IS_ERR(rt)) {
 692		netdev_dbg(gtp->dev, "no route for echo response from %pI4\n",
 693			   &iph->saddr);
 694		return -1;
 695	}
 696
 697	udp_tunnel_xmit_skb(rt, gtp->sk1u, skb,
 698			    fl4.saddr, fl4.daddr,
 699			    iph->tos,
 700			    ip4_dst_hoplimit(&rt->dst),
 701			    0,
 702			    htons(GTP1U_PORT), htons(GTP1U_PORT),
 703			    !net_eq(sock_net(gtp->sk1u),
 704				    dev_net(gtp->dev)),
 705			    false);
 706	return 0;
 707}
 708
 709static int gtp1u_handle_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb)
 710{
 711	struct gtp1_header_long *gtp1u;
 712	struct echo_info echo;
 713	struct sk_buff *msg;
 714	struct iphdr *iph;
 715	int ret;
 716
 717	gtp1u = (struct gtp1_header_long *)(skb->data + sizeof(struct udphdr));
 718
 719	/* 3GPP TS 29.281 5.1 - For the Echo Request, Echo Response,
 720	 * Error Indication and Supported Extension Headers Notification
 721	 * messages, the S flag shall be set to 1 and TEID shall be set to 0.
 722	 */
 723	if (!(gtp1u->flags & GTP1_F_SEQ) || gtp1u->tid)
 724		return -1;
 725
 726	iph = ip_hdr(skb);
 727	echo.ms.addr.s_addr = iph->daddr;
 728	echo.peer.addr.s_addr = iph->saddr;
 729	echo.gtp_version = GTP_V1;
 730
 731	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
 732	if (!msg)
 733		return -ENOMEM;
 734
 735	ret = gtp_genl_fill_echo(msg, 0, 0, 0, GTP_CMD_ECHOREQ, echo);
 736	if (ret < 0) {
 737		nlmsg_free(msg);
 738		return ret;
 739	}
 740
 741	return genlmsg_multicast_netns(&gtp_genl_family, dev_net(gtp->dev),
 742				       msg, 0, GTP_GENL_MCGRP, GFP_ATOMIC);
 743}
 744
 745static int gtp_parse_exthdrs(struct sk_buff *skb, unsigned int *hdrlen)
 746{
 747	struct gtp_ext_hdr *gtp_exthdr, _gtp_exthdr;
 748	unsigned int offset = *hdrlen;
 749	__u8 *next_type, _next_type;
 750
 751	/* From 29.060: "The Extension Header Length field specifies the length
 752	 * of the particular Extension header in 4 octets units."
 753	 *
 754	 * This length field includes length field size itself (1 byte),
 755	 * payload (variable length) and next type (1 byte). The extension
 756	 * header is aligned to to 4 bytes.
 757	 */
 758
 759	do {
 760		gtp_exthdr = skb_header_pointer(skb, offset, sizeof(*gtp_exthdr),
 761						&_gtp_exthdr);
 762		if (!gtp_exthdr || !gtp_exthdr->len)
 763			return -1;
 764
 765		offset += gtp_exthdr->len * 4;
 766
 767		/* From 29.060: "If no such Header follows, then the value of
 768		 * the Next Extension Header Type shall be 0."
 769		 */
 770		next_type = skb_header_pointer(skb, offset - 1,
 771					       sizeof(_next_type), &_next_type);
 772		if (!next_type)
 773			return -1;
 774
 775	} while (*next_type != 0);
 776
 777	*hdrlen = offset;
 778
 779	return 0;
 780}
 781
 782static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb)
 783{
 784	unsigned int hdrlen = sizeof(struct udphdr) +
 785			      sizeof(struct gtp1_header);
 786	struct gtp1_header *gtp1;
 787	struct pdp_ctx *pctx;
 788	__u16 inner_proto;
 789
 790	if (!pskb_may_pull(skb, hdrlen))
 791		return -1;
 792
 793	gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
 794
 795	if ((gtp1->flags >> 5) != GTP_V1)
 796		return 1;
 797
 798	/* If the sockets were created in kernel, it means that
 799	 * there is no daemon running in userspace which would
 800	 * handle echo request.
 801	 */
 802	if (gtp1->type == GTP_ECHO_REQ && gtp->sk_created)
 803		return gtp1u_send_echo_resp(gtp, skb);
 804
 805	if (gtp1->type == GTP_ECHO_RSP && gtp->sk_created)
 806		return gtp1u_handle_echo_resp(gtp, skb);
 807
 808	if (gtp1->type != GTP_TPDU)
 809		return 1;
 810
 811	/* From 29.060: "This field shall be present if and only if any one or
 812	 * more of the S, PN and E flags are set.".
 813	 *
 814	 * If any of the bit is set, then the remaining ones also have to be
 815	 * set.
 816	 */
 817	if (gtp1->flags & GTP1_F_MASK)
 818		hdrlen += 4;
 819
 820	/* Make sure the header is larger enough, including extensions. */
 821	if (!pskb_may_pull(skb, hdrlen))
 822		return -1;
 823
 824	if (gtp_inner_proto(skb, hdrlen, &inner_proto) < 0) {
 825		netdev_dbg(gtp->dev, "GTP packet does not encapsulate an IP packet\n");
 826		return -1;
 827	}
 828
 829	gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
 830
 831	pctx = gtp1_pdp_find(gtp, ntohl(gtp1->tid),
 832			     gtp_proto_to_family(inner_proto));
 833	if (!pctx) {
 834		netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
 835		return 1;
 836	}
 837
 838	if (gtp1->flags & GTP1_F_EXTHDR &&
 839	    gtp_parse_exthdrs(skb, &hdrlen) < 0)
 840		return -1;
 841
 842	return gtp_rx(pctx, skb, hdrlen, gtp->role, inner_proto);
 843}
 844
 845static void __gtp_encap_destroy(struct sock *sk)
 846{
 847	struct gtp_dev *gtp;
 848
 849	lock_sock(sk);
 850	gtp = sk->sk_user_data;
 851	if (gtp) {
 852		if (gtp->sk0 == sk)
 853			gtp->sk0 = NULL;
 854		else
 855			gtp->sk1u = NULL;
 856		WRITE_ONCE(udp_sk(sk)->encap_type, 0);
 857		rcu_assign_sk_user_data(sk, NULL);
 858		release_sock(sk);
 859		sock_put(sk);
 860		return;
 861	}
 862	release_sock(sk);
 863}
 864
 865static void gtp_encap_destroy(struct sock *sk)
 866{
 867	rtnl_lock();
 868	__gtp_encap_destroy(sk);
 869	rtnl_unlock();
 870}
 871
 872static void gtp_encap_disable_sock(struct sock *sk)
 873{
 874	if (!sk)
 875		return;
 876
 877	__gtp_encap_destroy(sk);
 878}
 879
 880static void gtp_encap_disable(struct gtp_dev *gtp)
 881{
 882	if (gtp->sk_created) {
 883		udp_tunnel_sock_release(gtp->sk0->sk_socket);
 884		udp_tunnel_sock_release(gtp->sk1u->sk_socket);
 885		gtp->sk_created = false;
 886		gtp->sk0 = NULL;
 887		gtp->sk1u = NULL;
 888	} else {
 889		gtp_encap_disable_sock(gtp->sk0);
 890		gtp_encap_disable_sock(gtp->sk1u);
 891	}
 892}
 893
 894/* UDP encapsulation receive handler. See net/ipv4/udp.c.
 895 * Return codes: 0: success, <0: error, >0: pass up to userspace UDP socket.
 896 */
 897static int gtp_encap_recv(struct sock *sk, struct sk_buff *skb)
 898{
 899	struct gtp_dev *gtp;
 900	int ret = 0;
 901
 902	gtp = rcu_dereference_sk_user_data(sk);
 903	if (!gtp)
 904		return 1;
 905
 906	netdev_dbg(gtp->dev, "encap_recv sk=%p\n", sk);
 907
 908	switch (READ_ONCE(udp_sk(sk)->encap_type)) {
 909	case UDP_ENCAP_GTP0:
 910		netdev_dbg(gtp->dev, "received GTP0 packet\n");
 911		ret = gtp0_udp_encap_recv(gtp, skb);
 912		break;
 913	case UDP_ENCAP_GTP1U:
 914		netdev_dbg(gtp->dev, "received GTP1U packet\n");
 915		ret = gtp1u_udp_encap_recv(gtp, skb);
 916		break;
 917	default:
 918		ret = -1; /* Shouldn't happen. */
 919	}
 920
 921	switch (ret) {
 922	case 1:
 923		netdev_dbg(gtp->dev, "pass up to the process\n");
 924		break;
 925	case 0:
 926		break;
 927	case -1:
 928		netdev_dbg(gtp->dev, "GTP packet has been dropped\n");
 929		kfree_skb(skb);
 930		ret = 0;
 931		break;
 932	}
 933
 934	return ret;
 935}
 936
 
 
 
 
 
 
 
 
 
 
 
 
 
 937static void gtp_dev_uninit(struct net_device *dev)
 938{
 939	struct gtp_dev *gtp = netdev_priv(dev);
 940
 941	gtp_encap_disable(gtp);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 942}
 943
 944static inline void gtp0_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
 945{
 946	int payload_len = skb->len;
 947	struct gtp0_header *gtp0;
 948
 949	gtp0 = skb_push(skb, sizeof(*gtp0));
 950
 951	gtp0->flags	= 0x1e; /* v0, GTP-non-prime. */
 952	gtp0->type	= GTP_TPDU;
 953	gtp0->length	= htons(payload_len);
 954	gtp0->seq	= htons((atomic_inc_return(&pctx->tx_seq) - 1) % 0xffff);
 955	gtp0->flow	= htons(pctx->u.v0.flow);
 956	gtp0->number	= 0xff;
 957	gtp0->spare[0]	= gtp0->spare[1] = gtp0->spare[2] = 0xff;
 958	gtp0->tid	= cpu_to_be64(pctx->u.v0.tid);
 959}
 960
 961static inline void gtp1_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
 962{
 963	int payload_len = skb->len;
 964	struct gtp1_header *gtp1;
 965
 966	gtp1 = skb_push(skb, sizeof(*gtp1));
 967
 968	/* Bits    8  7  6  5  4  3  2	1
 969	 *	  +--+--+--+--+--+--+--+--+
 970	 *	  |version |PT| 0| E| S|PN|
 971	 *	  +--+--+--+--+--+--+--+--+
 972	 *	    0  0  1  1	1  0  0  0
 973	 */
 974	gtp1->flags	= 0x30; /* v1, GTP-non-prime. */
 975	gtp1->type	= GTP_TPDU;
 976	gtp1->length	= htons(payload_len);
 977	gtp1->tid	= htonl(pctx->u.v1.o_tei);
 978
 979	/* TODO: Support for extension header, sequence number and N-PDU.
 980	 *	 Update the length field if any of them is available.
 981	 */
 982}
 983
 984struct gtp_pktinfo {
 985	struct sock		*sk;
 986	union {
 987		struct flowi4	fl4;
 988		struct flowi6	fl6;
 989	};
 990	union {
 991		struct rtable	*rt;
 992		struct rt6_info	*rt6;
 993	};
 994	struct pdp_ctx		*pctx;
 995	struct net_device	*dev;
 996	__u8			tos;
 997	__be16			gtph_port;
 998};
 999
1000static void gtp_push_header(struct sk_buff *skb, struct gtp_pktinfo *pktinfo)
1001{
1002	switch (pktinfo->pctx->gtp_version) {
1003	case GTP_V0:
1004		pktinfo->gtph_port = htons(GTP0_PORT);
1005		gtp0_push_header(skb, pktinfo->pctx);
1006		break;
1007	case GTP_V1:
1008		pktinfo->gtph_port = htons(GTP1U_PORT);
1009		gtp1_push_header(skb, pktinfo->pctx);
1010		break;
1011	}
1012}
1013
1014static inline void gtp_set_pktinfo_ipv4(struct gtp_pktinfo *pktinfo,
1015					struct sock *sk, __u8 tos,
1016					struct pdp_ctx *pctx, struct rtable *rt,
1017					struct flowi4 *fl4,
1018					struct net_device *dev)
1019{
1020	pktinfo->sk	= sk;
1021	pktinfo->tos	= tos;
1022	pktinfo->pctx	= pctx;
1023	pktinfo->rt	= rt;
1024	pktinfo->fl4	= *fl4;
1025	pktinfo->dev	= dev;
1026}
1027
1028static void gtp_set_pktinfo_ipv6(struct gtp_pktinfo *pktinfo,
1029				 struct sock *sk, __u8 tos,
1030				 struct pdp_ctx *pctx, struct rt6_info *rt6,
1031				 struct flowi6 *fl6,
1032				 struct net_device *dev)
1033{
1034	pktinfo->sk	= sk;
1035	pktinfo->tos	= tos;
1036	pktinfo->pctx	= pctx;
1037	pktinfo->rt6	= rt6;
1038	pktinfo->fl6	= *fl6;
1039	pktinfo->dev	= dev;
1040}
1041
1042static int gtp_build_skb_outer_ip4(struct sk_buff *skb, struct net_device *dev,
1043				   struct gtp_pktinfo *pktinfo,
1044				   struct pdp_ctx *pctx, __u8 tos,
1045				   __be16 frag_off)
1046{
 
 
1047	struct rtable *rt;
1048	struct flowi4 fl4;
 
1049	__be16 df;
1050	int mtu;
1051
1052	rt = ip4_route_output_gtp(&fl4, pctx->sk, pctx->peer.addr.s_addr,
1053				  inet_sk(pctx->sk)->inet_saddr);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1054	if (IS_ERR(rt)) {
1055		netdev_dbg(dev, "no route to SSGN %pI4\n",
1056			   &pctx->peer.addr.s_addr);
1057		dev->stats.tx_carrier_errors++;
1058		goto err;
1059	}
1060
1061	if (rt->dst.dev == dev) {
1062		netdev_dbg(dev, "circular route to SSGN %pI4\n",
1063			   &pctx->peer.addr.s_addr);
1064		dev->stats.collisions++;
1065		goto err_rt;
1066	}
1067
 
 
1068	/* This is similar to tnl_update_pmtu(). */
1069	df = frag_off;
1070	if (df) {
1071		mtu = dst_mtu(&rt->dst) - dev->hard_header_len -
1072			sizeof(struct iphdr) - sizeof(struct udphdr);
1073		switch (pctx->gtp_version) {
1074		case GTP_V0:
1075			mtu -= sizeof(struct gtp0_header);
1076			break;
1077		case GTP_V1:
1078			mtu -= sizeof(struct gtp1_header);
1079			break;
1080		}
1081	} else {
1082		mtu = dst_mtu(&rt->dst);
1083	}
1084
1085	skb_dst_update_pmtu_no_confirm(skb, mtu);
1086
1087	if (frag_off & htons(IP_DF) &&
1088	    ((!skb_is_gso(skb) && skb->len > mtu) ||
1089	     (skb_is_gso(skb) && !skb_gso_validate_network_len(skb, mtu)))) {
1090		netdev_dbg(dev, "packet too big, fragmentation needed\n");
 
1091		icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
1092			      htonl(mtu));
1093		goto err_rt;
1094	}
1095
1096	gtp_set_pktinfo_ipv4(pktinfo, pctx->sk, tos, pctx, rt, &fl4, dev);
1097	gtp_push_header(skb, pktinfo);
1098
1099	return 0;
1100err_rt:
1101	ip_rt_put(rt);
1102err:
1103	return -EBADMSG;
1104}
1105
1106static int gtp_build_skb_outer_ip6(struct net *net, struct sk_buff *skb,
1107				   struct net_device *dev,
1108				   struct gtp_pktinfo *pktinfo,
1109				   struct pdp_ctx *pctx, __u8 tos)
1110{
1111	struct dst_entry *dst;
1112	struct rt6_info *rt;
1113	struct flowi6 fl6;
1114	int mtu;
1115
1116	rt = ip6_route_output_gtp(net, &fl6, pctx->sk, &pctx->peer.addr6,
1117				  &inet6_sk(pctx->sk)->saddr);
1118	if (IS_ERR(rt)) {
1119		netdev_dbg(dev, "no route to SSGN %pI6\n",
1120			   &pctx->peer.addr6);
1121		dev->stats.tx_carrier_errors++;
1122		goto err;
1123	}
1124	dst = &rt->dst;
1125
1126	if (rt->dst.dev == dev) {
1127		netdev_dbg(dev, "circular route to SSGN %pI6\n",
1128			   &pctx->peer.addr6);
1129		dev->stats.collisions++;
1130		goto err_rt;
1131	}
1132
1133	mtu = dst_mtu(&rt->dst) - dev->hard_header_len -
1134		sizeof(struct ipv6hdr) - sizeof(struct udphdr);
1135	switch (pctx->gtp_version) {
1136	case GTP_V0:
1137		mtu -= sizeof(struct gtp0_header);
1138		break;
1139	case GTP_V1:
1140		mtu -= sizeof(struct gtp1_header);
1141		break;
1142	}
1143
1144	skb_dst_update_pmtu_no_confirm(skb, mtu);
1145
1146	if ((!skb_is_gso(skb) && skb->len > mtu) ||
1147	    (skb_is_gso(skb) && !skb_gso_validate_network_len(skb, mtu))) {
1148		netdev_dbg(dev, "packet too big, fragmentation needed\n");
1149		icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1150		goto err_rt;
1151	}
1152
1153	gtp_set_pktinfo_ipv6(pktinfo, pctx->sk, tos, pctx, rt, &fl6, dev);
1154	gtp_push_header(skb, pktinfo);
1155
1156	return 0;
1157err_rt:
1158	dst_release(dst);
1159err:
1160	return -EBADMSG;
1161}
1162
1163static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev,
1164			     struct gtp_pktinfo *pktinfo)
1165{
1166	struct gtp_dev *gtp = netdev_priv(dev);
1167	struct net *net = gtp->net;
1168	struct pdp_ctx *pctx;
1169	struct iphdr *iph;
1170	int ret;
1171
1172	/* Read the IP destination address and resolve the PDP context.
1173	 * Prepend PDP header with TEI/TID from PDP ctx.
1174	 */
1175	iph = ip_hdr(skb);
1176	if (gtp->role == GTP_ROLE_SGSN)
1177		pctx = ipv4_pdp_find(gtp, iph->saddr);
1178	else
1179		pctx = ipv4_pdp_find(gtp, iph->daddr);
1180
1181	if (!pctx) {
1182		netdev_dbg(dev, "no PDP ctx found for %pI4, skip\n",
1183			   &iph->daddr);
1184		return -ENOENT;
1185	}
1186	netdev_dbg(dev, "found PDP context %p\n", pctx);
1187
1188	switch (pctx->sk->sk_family) {
1189	case AF_INET:
1190		ret = gtp_build_skb_outer_ip4(skb, dev, pktinfo, pctx,
1191					      iph->tos, iph->frag_off);
1192		break;
1193	case AF_INET6:
1194		ret = gtp_build_skb_outer_ip6(net, skb, dev, pktinfo, pctx,
1195					      iph->tos);
1196		break;
1197	default:
1198		ret = -1;
1199		WARN_ON_ONCE(1);
1200		break;
1201	}
1202
1203	if (ret < 0)
1204		return ret;
1205
1206	netdev_dbg(dev, "gtp -> IP src: %pI4 dst: %pI4\n",
1207		   &iph->saddr, &iph->daddr);
1208
1209	return 0;
1210}
1211
1212static int gtp_build_skb_ip6(struct sk_buff *skb, struct net_device *dev,
1213			     struct gtp_pktinfo *pktinfo)
1214{
1215	struct gtp_dev *gtp = netdev_priv(dev);
1216	struct net *net = gtp->net;
1217	struct pdp_ctx *pctx;
1218	struct ipv6hdr *ip6h;
1219	__u8 tos;
1220	int ret;
1221
1222	/* Read the IP destination address and resolve the PDP context.
1223	 * Prepend PDP header with TEI/TID from PDP ctx.
1224	 */
1225	ip6h = ipv6_hdr(skb);
1226	if (gtp->role == GTP_ROLE_SGSN)
1227		pctx = ipv6_pdp_find(gtp, &ip6h->saddr);
1228	else
1229		pctx = ipv6_pdp_find(gtp, &ip6h->daddr);
1230
1231	if (!pctx) {
1232		netdev_dbg(dev, "no PDP ctx found for %pI6, skip\n",
1233			   &ip6h->daddr);
1234		return -ENOENT;
1235	}
1236	netdev_dbg(dev, "found PDP context %p\n", pctx);
1237
1238	tos = ipv6_get_dsfield(ip6h);
1239
1240	switch (pctx->sk->sk_family) {
1241	case AF_INET:
1242		ret = gtp_build_skb_outer_ip4(skb, dev, pktinfo, pctx, tos, 0);
1243		break;
1244	case AF_INET6:
1245		ret = gtp_build_skb_outer_ip6(net, skb, dev, pktinfo, pctx, tos);
1246		break;
1247	default:
1248		ret = -1;
1249		WARN_ON_ONCE(1);
1250		break;
1251	}
1252
1253	if (ret < 0)
1254		return ret;
1255
1256	netdev_dbg(dev, "gtp -> IP src: %pI6 dst: %pI6\n",
1257		   &ip6h->saddr, &ip6h->daddr);
1258
1259	return 0;
1260}
1261
1262static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev)
1263{
1264	unsigned int proto = ntohs(skb->protocol);
1265	struct gtp_pktinfo pktinfo;
1266	int err;
1267
1268	/* Ensure there is sufficient headroom. */
1269	if (skb_cow_head(skb, dev->needed_headroom))
1270		goto tx_err;
1271
1272	if (!pskb_inet_may_pull(skb))
1273		goto tx_err;
1274
1275	skb_reset_inner_headers(skb);
1276
1277	/* PDP context lookups in gtp_build_skb_*() need rcu read-side lock. */
1278	rcu_read_lock();
1279	switch (proto) {
1280	case ETH_P_IP:
1281		err = gtp_build_skb_ip4(skb, dev, &pktinfo);
1282		break;
1283	case ETH_P_IPV6:
1284		err = gtp_build_skb_ip6(skb, dev, &pktinfo);
1285		break;
1286	default:
1287		err = -EOPNOTSUPP;
1288		break;
1289	}
1290	rcu_read_unlock();
1291
1292	if (err < 0)
1293		goto tx_err;
1294
1295	switch (pktinfo.pctx->sk->sk_family) {
1296	case AF_INET:
 
 
1297		udp_tunnel_xmit_skb(pktinfo.rt, pktinfo.sk, skb,
1298				    pktinfo.fl4.saddr, pktinfo.fl4.daddr,
1299				    pktinfo.tos,
1300				    ip4_dst_hoplimit(&pktinfo.rt->dst),
1301				    0,
1302				    pktinfo.gtph_port, pktinfo.gtph_port,
1303				    !net_eq(sock_net(pktinfo.pctx->sk),
1304					    dev_net(dev)),
1305				    false);
1306		break;
1307	case AF_INET6:
1308#if IS_ENABLED(CONFIG_IPV6)
1309		udp_tunnel6_xmit_skb(&pktinfo.rt6->dst, pktinfo.sk, skb, dev,
1310				     &pktinfo.fl6.saddr, &pktinfo.fl6.daddr,
1311				     pktinfo.tos,
1312				     ip6_dst_hoplimit(&pktinfo.rt->dst),
1313				     0,
1314				     pktinfo.gtph_port, pktinfo.gtph_port,
1315				     false);
1316#else
1317		goto tx_err;
1318#endif
1319		break;
1320	}
1321
1322	return NETDEV_TX_OK;
1323tx_err:
1324	dev->stats.tx_errors++;
1325	dev_kfree_skb(skb);
1326	return NETDEV_TX_OK;
1327}
1328
1329static const struct net_device_ops gtp_netdev_ops = {
 
1330	.ndo_uninit		= gtp_dev_uninit,
1331	.ndo_start_xmit		= gtp_dev_xmit,
 
1332};
1333
1334static const struct device_type gtp_type = {
1335	.name = "gtp",
1336};
1337
1338#define GTP_TH_MAXLEN	(sizeof(struct udphdr) + sizeof(struct gtp0_header))
1339#define GTP_IPV4_MAXLEN	(sizeof(struct iphdr) + GTP_TH_MAXLEN)
1340
1341static void gtp_link_setup(struct net_device *dev)
1342{
1343	struct gtp_dev *gtp = netdev_priv(dev);
1344
1345	dev->netdev_ops		= &gtp_netdev_ops;
1346	dev->needs_free_netdev	= true;
1347	SET_NETDEV_DEVTYPE(dev, &gtp_type);
1348
1349	dev->hard_header_len = 0;
1350	dev->addr_len = 0;
1351	dev->mtu = ETH_DATA_LEN - GTP_IPV4_MAXLEN;
1352
1353	/* Zero header length. */
1354	dev->type = ARPHRD_NONE;
1355	dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1356
1357	dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
1358	dev->priv_flags	|= IFF_NO_QUEUE;
1359	dev->lltx = true;
1360	netif_keep_dst(dev);
1361
1362	dev->needed_headroom	= LL_MAX_HEADER + GTP_IPV4_MAXLEN;
1363	gtp->dev = dev;
 
 
 
1364}
1365
1366static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize);
1367static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]);
1368
1369static void gtp_destructor(struct net_device *dev)
1370{
1371	struct gtp_dev *gtp = netdev_priv(dev);
1372
1373	kfree(gtp->addr_hash);
1374	kfree(gtp->tid_hash);
1375}
1376
1377static int gtp_sock_udp_config(struct udp_port_cfg *udp_conf,
1378			       const struct nlattr *nla, int family)
1379{
1380	udp_conf->family = family;
1381
1382	switch (udp_conf->family) {
1383	case AF_INET:
1384		udp_conf->local_ip.s_addr = nla_get_be32(nla);
1385		break;
1386#if IS_ENABLED(CONFIG_IPV6)
1387	case AF_INET6:
1388		udp_conf->local_ip6 = nla_get_in6_addr(nla);
1389		break;
1390#endif
1391	default:
1392		return -EOPNOTSUPP;
1393	}
1394
1395	return 0;
1396}
1397
1398static struct sock *gtp_create_sock(int type, struct gtp_dev *gtp,
1399				    const struct nlattr *nla, int family)
1400{
1401	struct udp_tunnel_sock_cfg tuncfg = {};
1402	struct udp_port_cfg udp_conf = {};
1403	struct net *net = gtp->net;
1404	struct socket *sock;
1405	int err;
1406
1407	if (nla) {
1408		err = gtp_sock_udp_config(&udp_conf, nla, family);
1409		if (err < 0)
1410			return ERR_PTR(err);
1411	} else {
1412		udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
1413		udp_conf.family = AF_INET;
1414	}
1415
1416	if (type == UDP_ENCAP_GTP0)
1417		udp_conf.local_udp_port = htons(GTP0_PORT);
1418	else if (type == UDP_ENCAP_GTP1U)
1419		udp_conf.local_udp_port = htons(GTP1U_PORT);
1420	else
1421		return ERR_PTR(-EINVAL);
1422
1423	err = udp_sock_create(net, &udp_conf, &sock);
1424	if (err)
1425		return ERR_PTR(err);
1426
1427	tuncfg.sk_user_data = gtp;
1428	tuncfg.encap_type = type;
1429	tuncfg.encap_rcv = gtp_encap_recv;
1430	tuncfg.encap_destroy = NULL;
1431
1432	setup_udp_tunnel_sock(net, sock, &tuncfg);
1433
1434	return sock->sk;
1435}
1436
1437static int gtp_create_sockets(struct gtp_dev *gtp, const struct nlattr *nla,
1438			      int family)
1439{
1440	struct sock *sk1u;
1441	struct sock *sk0;
1442
1443	sk0 = gtp_create_sock(UDP_ENCAP_GTP0, gtp, nla, family);
1444	if (IS_ERR(sk0))
1445		return PTR_ERR(sk0);
1446
1447	sk1u = gtp_create_sock(UDP_ENCAP_GTP1U, gtp, nla, family);
1448	if (IS_ERR(sk1u)) {
1449		udp_tunnel_sock_release(sk0->sk_socket);
1450		return PTR_ERR(sk1u);
1451	}
1452
1453	gtp->sk_created = true;
1454	gtp->sk0 = sk0;
1455	gtp->sk1u = sk1u;
1456
1457	return 0;
1458}
1459
1460#define GTP_TH_MAXLEN	(sizeof(struct udphdr) + sizeof(struct gtp0_header))
1461#define GTP_IPV6_MAXLEN	(sizeof(struct ipv6hdr) + GTP_TH_MAXLEN)
1462
1463static int gtp_newlink(struct net *src_net, struct net_device *dev,
1464		       struct nlattr *tb[], struct nlattr *data[],
1465		       struct netlink_ext_ack *extack)
1466{
1467	unsigned int role = GTP_ROLE_GGSN;
1468	struct gtp_dev *gtp;
1469	struct gtp_net *gn;
1470	int hashsize, err;
1471
1472#if !IS_ENABLED(CONFIG_IPV6)
1473	if (data[IFLA_GTP_LOCAL6])
1474		return -EAFNOSUPPORT;
1475#endif
1476
1477	gtp = netdev_priv(dev);
1478
 
 
 
 
1479	if (!data[IFLA_GTP_PDP_HASHSIZE]) {
1480		hashsize = 1024;
1481	} else {
1482		hashsize = nla_get_u32(data[IFLA_GTP_PDP_HASHSIZE]);
1483		if (!hashsize)
1484			hashsize = 1024;
1485	}
1486
1487	if (data[IFLA_GTP_ROLE]) {
1488		role = nla_get_u32(data[IFLA_GTP_ROLE]);
1489		if (role > GTP_ROLE_SGSN)
1490			return -EINVAL;
1491	}
1492	gtp->role = role;
1493
1494	gtp->restart_count = nla_get_u8_default(data[IFLA_GTP_RESTART_COUNT],
1495						0);
1496
1497	gtp->net = src_net;
1498
1499	err = gtp_hashtable_new(gtp, hashsize);
1500	if (err < 0)
1501		return err;
1502
1503	if (data[IFLA_GTP_CREATE_SOCKETS]) {
1504		if (data[IFLA_GTP_LOCAL6])
1505			err = gtp_create_sockets(gtp, data[IFLA_GTP_LOCAL6], AF_INET6);
1506		else
1507			err = gtp_create_sockets(gtp, data[IFLA_GTP_LOCAL], AF_INET);
1508	} else {
1509		err = gtp_encap_enable(gtp, data);
1510	}
1511
1512	if (err < 0)
1513		goto out_hashtable;
1514
1515	if ((gtp->sk0 && gtp->sk0->sk_family == AF_INET6) ||
1516	    (gtp->sk1u && gtp->sk1u->sk_family == AF_INET6)) {
1517		dev->mtu = ETH_DATA_LEN - GTP_IPV6_MAXLEN;
1518		dev->needed_headroom = LL_MAX_HEADER + GTP_IPV6_MAXLEN;
1519	}
1520
1521	err = register_netdevice(dev);
1522	if (err < 0) {
1523		netdev_dbg(dev, "failed to register new netdev %d\n", err);
1524		goto out_encap;
1525	}
1526
1527	gn = net_generic(src_net, gtp_net_id);
1528	list_add(&gtp->list, &gn->gtp_dev_list);
1529	dev->priv_destructor = gtp_destructor;
1530
1531	netdev_dbg(dev, "registered new GTP interface\n");
1532
1533	return 0;
1534
1535out_encap:
1536	gtp_encap_disable(gtp);
1537out_hashtable:
1538	kfree(gtp->addr_hash);
1539	kfree(gtp->tid_hash);
 
 
1540	return err;
1541}
1542
1543static void gtp_dellink(struct net_device *dev, struct list_head *head)
1544{
1545	struct gtp_dev *gtp = netdev_priv(dev);
1546	struct hlist_node *next;
1547	struct pdp_ctx *pctx;
1548	int i;
1549
1550	for (i = 0; i < gtp->hash_size; i++)
1551		hlist_for_each_entry_safe(pctx, next, &gtp->tid_hash[i], hlist_tid)
1552			pdp_context_delete(pctx);
1553
1554	list_del(&gtp->list);
1555	unregister_netdevice_queue(dev, head);
1556}
1557
1558static const struct nla_policy gtp_policy[IFLA_GTP_MAX + 1] = {
1559	[IFLA_GTP_FD0]			= { .type = NLA_U32 },
1560	[IFLA_GTP_FD1]			= { .type = NLA_U32 },
1561	[IFLA_GTP_PDP_HASHSIZE]		= { .type = NLA_U32 },
1562	[IFLA_GTP_ROLE]			= { .type = NLA_U32 },
1563	[IFLA_GTP_CREATE_SOCKETS]	= { .type = NLA_U8 },
1564	[IFLA_GTP_RESTART_COUNT]	= { .type = NLA_U8 },
1565	[IFLA_GTP_LOCAL]		= { .type = NLA_U32 },
1566	[IFLA_GTP_LOCAL6]		= { .len = sizeof(struct in6_addr) },
1567};
1568
1569static int gtp_validate(struct nlattr *tb[], struct nlattr *data[],
1570			struct netlink_ext_ack *extack)
1571{
1572	if (!data)
1573		return -EINVAL;
1574
1575	return 0;
1576}
1577
1578static size_t gtp_get_size(const struct net_device *dev)
1579{
1580	return nla_total_size(sizeof(__u32)) + /* IFLA_GTP_PDP_HASHSIZE */
1581		nla_total_size(sizeof(__u32)) + /* IFLA_GTP_ROLE */
1582		nla_total_size(sizeof(__u8)); /* IFLA_GTP_RESTART_COUNT */
1583}
1584
1585static int gtp_fill_info(struct sk_buff *skb, const struct net_device *dev)
1586{
1587	struct gtp_dev *gtp = netdev_priv(dev);
1588
1589	if (nla_put_u32(skb, IFLA_GTP_PDP_HASHSIZE, gtp->hash_size))
1590		goto nla_put_failure;
1591	if (nla_put_u32(skb, IFLA_GTP_ROLE, gtp->role))
1592		goto nla_put_failure;
1593	if (nla_put_u8(skb, IFLA_GTP_RESTART_COUNT, gtp->restart_count))
1594		goto nla_put_failure;
1595
1596	return 0;
1597
1598nla_put_failure:
1599	return -EMSGSIZE;
1600}
1601
1602static struct rtnl_link_ops gtp_link_ops __read_mostly = {
1603	.kind		= "gtp",
1604	.maxtype	= IFLA_GTP_MAX,
1605	.policy		= gtp_policy,
1606	.priv_size	= sizeof(struct gtp_dev),
1607	.setup		= gtp_link_setup,
1608	.validate	= gtp_validate,
1609	.newlink	= gtp_newlink,
1610	.dellink	= gtp_dellink,
1611	.get_size	= gtp_get_size,
1612	.fill_info	= gtp_fill_info,
1613};
1614
1615static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize)
1616{
1617	int i;
1618
1619	gtp->addr_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
1620				       GFP_KERNEL | __GFP_NOWARN);
1621	if (gtp->addr_hash == NULL)
1622		return -ENOMEM;
1623
1624	gtp->tid_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
1625				      GFP_KERNEL | __GFP_NOWARN);
1626	if (gtp->tid_hash == NULL)
1627		goto err1;
1628
1629	gtp->hash_size = hsize;
1630
1631	for (i = 0; i < hsize; i++) {
1632		INIT_HLIST_HEAD(&gtp->addr_hash[i]);
1633		INIT_HLIST_HEAD(&gtp->tid_hash[i]);
1634	}
1635	return 0;
1636err1:
1637	kfree(gtp->addr_hash);
1638	return -ENOMEM;
1639}
1640
1641static struct sock *gtp_encap_enable_socket(int fd, int type,
1642					    struct gtp_dev *gtp)
1643{
1644	struct udp_tunnel_sock_cfg tuncfg = {NULL};
1645	struct socket *sock;
1646	struct sock *sk;
1647	int err;
1648
1649	pr_debug("enable gtp on %d, %d\n", fd, type);
1650
1651	sock = sockfd_lookup(fd, &err);
1652	if (!sock) {
1653		pr_debug("gtp socket fd=%d not found\n", fd);
1654		return ERR_PTR(err);
1655	}
1656
1657	sk = sock->sk;
1658	if (sk->sk_protocol != IPPROTO_UDP ||
1659	    sk->sk_type != SOCK_DGRAM ||
1660	    (sk->sk_family != AF_INET && sk->sk_family != AF_INET6)) {
1661		pr_debug("socket fd=%d not UDP\n", fd);
1662		sk = ERR_PTR(-EINVAL);
1663		goto out_sock;
1664	}
1665
1666	if (sk->sk_family == AF_INET6 &&
1667	    !sk->sk_ipv6only) {
1668		sk = ERR_PTR(-EADDRNOTAVAIL);
1669		goto out_sock;
1670	}
1671
1672	lock_sock(sk);
1673	if (sk->sk_user_data) {
1674		sk = ERR_PTR(-EBUSY);
1675		goto out_rel_sock;
1676	}
1677
1678	sock_hold(sk);
1679
1680	tuncfg.sk_user_data = gtp;
1681	tuncfg.encap_type = type;
1682	tuncfg.encap_rcv = gtp_encap_recv;
1683	tuncfg.encap_destroy = gtp_encap_destroy;
1684
1685	setup_udp_tunnel_sock(sock_net(sock->sk), sock, &tuncfg);
1686
1687out_rel_sock:
1688	release_sock(sock->sk);
1689out_sock:
1690	sockfd_put(sock);
1691	return sk;
1692}
1693
1694static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[])
1695{
1696	struct sock *sk1u = NULL;
1697	struct sock *sk0 = NULL;
1698
1699	if (!data[IFLA_GTP_FD0] && !data[IFLA_GTP_FD1])
1700		return -EINVAL;
1701
1702	if (data[IFLA_GTP_FD0]) {
1703		int fd0 = nla_get_u32(data[IFLA_GTP_FD0]);
1704
1705		if (fd0 >= 0) {
1706			sk0 = gtp_encap_enable_socket(fd0, UDP_ENCAP_GTP0, gtp);
1707			if (IS_ERR(sk0))
1708				return PTR_ERR(sk0);
1709		}
1710	}
1711
1712	if (data[IFLA_GTP_FD1]) {
1713		int fd1 = nla_get_u32(data[IFLA_GTP_FD1]);
1714
1715		if (fd1 >= 0) {
1716			sk1u = gtp_encap_enable_socket(fd1, UDP_ENCAP_GTP1U, gtp);
1717			if (IS_ERR(sk1u)) {
1718				gtp_encap_disable_sock(sk0);
1719				return PTR_ERR(sk1u);
1720			}
 
 
 
 
 
 
 
1721		}
1722	}
1723
1724	gtp->sk0 = sk0;
1725	gtp->sk1u = sk1u;
1726
1727	if (sk0 && sk1u &&
1728	    sk0->sk_family != sk1u->sk_family) {
1729		gtp_encap_disable_sock(sk0);
1730		gtp_encap_disable_sock(sk1u);
1731		return -EINVAL;
1732	}
1733
1734	return 0;
1735}
1736
1737static struct gtp_dev *gtp_find_dev(struct net *src_net, struct nlattr *nla[])
1738{
1739	struct gtp_dev *gtp = NULL;
1740	struct net_device *dev;
1741	struct net *net;
1742
1743	/* Examine the link attributes and figure out which network namespace
1744	 * we are talking about.
1745	 */
1746	if (nla[GTPA_NET_NS_FD])
1747		net = get_net_ns_by_fd(nla_get_u32(nla[GTPA_NET_NS_FD]));
1748	else
1749		net = get_net(src_net);
1750
1751	if (IS_ERR(net))
1752		return NULL;
1753
1754	/* Check if there's an existing gtpX device to configure */
1755	dev = dev_get_by_index_rcu(net, nla_get_u32(nla[GTPA_LINK]));
1756	if (dev && dev->netdev_ops == &gtp_netdev_ops)
1757		gtp = netdev_priv(dev);
1758
1759	put_net(net);
1760	return gtp;
1761}
1762
1763static void gtp_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info)
1764{
1765	pctx->gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]);
 
 
 
 
 
1766
1767	switch (pctx->gtp_version) {
1768	case GTP_V0:
1769		/* According to TS 09.60, sections 7.5.1 and 7.5.2, the flow
1770		 * label needs to be the same for uplink and downlink packets,
1771		 * so let's annotate this.
1772		 */
1773		pctx->u.v0.tid = nla_get_u64(info->attrs[GTPA_TID]);
1774		pctx->u.v0.flow = nla_get_u16(info->attrs[GTPA_FLOW]);
1775		break;
1776	case GTP_V1:
1777		pctx->u.v1.i_tei = nla_get_u32(info->attrs[GTPA_I_TEI]);
1778		pctx->u.v1.o_tei = nla_get_u32(info->attrs[GTPA_O_TEI]);
1779		break;
1780	default:
1781		break;
1782	}
1783}
1784
1785static void ip_pdp_peer_fill(struct pdp_ctx *pctx, struct genl_info *info)
1786{
1787	if (info->attrs[GTPA_PEER_ADDRESS]) {
1788		pctx->peer.addr.s_addr =
1789			nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]);
1790	} else if (info->attrs[GTPA_PEER_ADDR6]) {
1791		pctx->peer.addr6 = nla_get_in6_addr(info->attrs[GTPA_PEER_ADDR6]);
1792	}
1793}
1794
1795static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info)
1796{
1797	ip_pdp_peer_fill(pctx, info);
1798	pctx->ms.addr.s_addr =
1799		nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
1800	gtp_pdp_fill(pctx, info);
1801}
1802
1803static bool ipv6_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info)
1804{
1805	ip_pdp_peer_fill(pctx, info);
1806	pctx->ms.addr6 = nla_get_in6_addr(info->attrs[GTPA_MS_ADDR6]);
1807	if (pctx->ms.addr6.s6_addr32[2] ||
1808	    pctx->ms.addr6.s6_addr32[3])
1809		return false;
1810
1811	gtp_pdp_fill(pctx, info);
1812
1813	return true;
1814}
1815
1816static struct pdp_ctx *gtp_pdp_add(struct gtp_dev *gtp, struct sock *sk,
1817				   struct genl_info *info)
1818{
1819	struct pdp_ctx *pctx, *pctx_tid = NULL;
1820	struct net_device *dev = gtp->dev;
1821	u32 hash_ms, hash_tid = 0;
1822	struct in6_addr ms_addr6;
1823	unsigned int version;
1824	bool found = false;
1825	__be32 ms_addr;
1826	int family;
1827
 
 
1828	version = nla_get_u32(info->attrs[GTPA_VERSION]);
1829
1830	family = nla_get_u8_default(info->attrs[GTPA_FAMILY], AF_INET);
1831
1832#if !IS_ENABLED(CONFIG_IPV6)
1833	if (family == AF_INET6)
1834		return ERR_PTR(-EAFNOSUPPORT);
1835#endif
1836	if (!info->attrs[GTPA_PEER_ADDRESS] &&
1837	    !info->attrs[GTPA_PEER_ADDR6])
1838		return ERR_PTR(-EINVAL);
1839
1840	if ((info->attrs[GTPA_PEER_ADDRESS] &&
1841	     sk->sk_family == AF_INET6) ||
1842	    (info->attrs[GTPA_PEER_ADDR6] &&
1843	     sk->sk_family == AF_INET))
1844		return ERR_PTR(-EAFNOSUPPORT);
1845
1846	switch (family) {
1847	case AF_INET:
1848		if (!info->attrs[GTPA_MS_ADDRESS] ||
1849		    info->attrs[GTPA_MS_ADDR6])
1850			return ERR_PTR(-EINVAL);
1851
1852		ms_addr = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
1853		hash_ms = ipv4_hashfn(ms_addr) % gtp->hash_size;
1854		pctx = ipv4_pdp_find(gtp, ms_addr);
1855		break;
1856	case AF_INET6:
1857		if (!info->attrs[GTPA_MS_ADDR6] ||
1858		    info->attrs[GTPA_MS_ADDRESS])
1859			return ERR_PTR(-EINVAL);
1860
1861		ms_addr6 = nla_get_in6_addr(info->attrs[GTPA_MS_ADDR6]);
1862		hash_ms = ipv6_hashfn(&ms_addr6) % gtp->hash_size;
1863		pctx = ipv6_pdp_find(gtp, &ms_addr6);
1864		break;
1865	default:
1866		return ERR_PTR(-EAFNOSUPPORT);
1867	}
1868	if (pctx)
1869		found = true;
1870	if (version == GTP_V0)
1871		pctx_tid = gtp0_pdp_find(gtp,
1872					 nla_get_u64(info->attrs[GTPA_TID]),
1873					 family);
1874	else if (version == GTP_V1)
1875		pctx_tid = gtp1_pdp_find(gtp,
1876					 nla_get_u32(info->attrs[GTPA_I_TEI]),
1877					 family);
1878	if (pctx_tid)
1879		found = true;
1880
1881	if (found) {
1882		if (info->nlhdr->nlmsg_flags & NLM_F_EXCL)
1883			return ERR_PTR(-EEXIST);
1884		if (info->nlhdr->nlmsg_flags & NLM_F_REPLACE)
1885			return ERR_PTR(-EOPNOTSUPP);
1886
1887		if (pctx && pctx_tid)
1888			return ERR_PTR(-EEXIST);
1889		if (!pctx)
1890			pctx = pctx_tid;
1891
1892		switch (pctx->af) {
1893		case AF_INET:
1894			ipv4_pdp_fill(pctx, info);
1895			break;
1896		case AF_INET6:
1897			if (!ipv6_pdp_fill(pctx, info))
1898				return ERR_PTR(-EADDRNOTAVAIL);
1899			break;
1900		}
1901
1902		if (pctx->gtp_version == GTP_V0)
1903			netdev_dbg(dev, "GTPv0-U: update tunnel id = %llx (pdp %p)\n",
1904				   pctx->u.v0.tid, pctx);
1905		else if (pctx->gtp_version == GTP_V1)
1906			netdev_dbg(dev, "GTPv1-U: update tunnel id = %x/%x (pdp %p)\n",
1907				   pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
1908
1909		return pctx;
1910
1911	}
1912
1913	pctx = kmalloc(sizeof(*pctx), GFP_ATOMIC);
1914	if (pctx == NULL)
1915		return ERR_PTR(-ENOMEM);
1916
1917	sock_hold(sk);
1918	pctx->sk = sk;
1919	pctx->dev = gtp->dev;
1920	pctx->af = family;
1921
1922	switch (pctx->af) {
1923	case AF_INET:
1924		if (!info->attrs[GTPA_MS_ADDRESS]) {
1925			sock_put(sk);
1926			kfree(pctx);
1927			return ERR_PTR(-EINVAL);
1928		}
1929
1930		ipv4_pdp_fill(pctx, info);
1931		break;
1932	case AF_INET6:
1933		if (!info->attrs[GTPA_MS_ADDR6]) {
1934			sock_put(sk);
1935			kfree(pctx);
1936			return ERR_PTR(-EINVAL);
1937		}
1938
1939		if (!ipv6_pdp_fill(pctx, info)) {
1940			sock_put(sk);
1941			kfree(pctx);
1942			return ERR_PTR(-EADDRNOTAVAIL);
1943		}
1944		break;
1945	}
1946	atomic_set(&pctx->tx_seq, 0);
1947
1948	switch (pctx->gtp_version) {
1949	case GTP_V0:
1950		/* TS 09.60: "The flow label identifies unambiguously a GTP
1951		 * flow.". We use the tid for this instead, I cannot find a
1952		 * situation in which this doesn't unambiguosly identify the
1953		 * PDP context.
1954		 */
1955		hash_tid = gtp0_hashfn(pctx->u.v0.tid) % gtp->hash_size;
1956		break;
1957	case GTP_V1:
1958		hash_tid = gtp1u_hashfn(pctx->u.v1.i_tei) % gtp->hash_size;
1959		break;
1960	}
1961
1962	hlist_add_head_rcu(&pctx->hlist_addr, &gtp->addr_hash[hash_ms]);
1963	hlist_add_head_rcu(&pctx->hlist_tid, &gtp->tid_hash[hash_tid]);
1964
1965	switch (pctx->gtp_version) {
1966	case GTP_V0:
1967		netdev_dbg(dev, "GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
1968			   pctx->u.v0.tid, &pctx->peer.addr,
1969			   &pctx->ms.addr, pctx);
1970		break;
1971	case GTP_V1:
1972		netdev_dbg(dev, "GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
1973			   pctx->u.v1.i_tei, pctx->u.v1.o_tei,
1974			   &pctx->peer.addr, &pctx->ms.addr, pctx);
1975		break;
1976	}
1977
1978	return pctx;
1979}
1980
1981static void pdp_context_free(struct rcu_head *head)
1982{
1983	struct pdp_ctx *pctx = container_of(head, struct pdp_ctx, rcu_head);
1984
1985	sock_put(pctx->sk);
1986	kfree(pctx);
1987}
1988
1989static void pdp_context_delete(struct pdp_ctx *pctx)
1990{
1991	hlist_del_rcu(&pctx->hlist_tid);
1992	hlist_del_rcu(&pctx->hlist_addr);
1993	call_rcu(&pctx->rcu_head, pdp_context_free);
1994}
1995
1996static int gtp_tunnel_notify(struct pdp_ctx *pctx, u8 cmd, gfp_t allocation);
1997
1998static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info)
1999{
2000	unsigned int version;
2001	struct pdp_ctx *pctx;
2002	struct gtp_dev *gtp;
2003	struct sock *sk;
2004	int err;
2005
2006	if (!info->attrs[GTPA_VERSION] ||
2007	    !info->attrs[GTPA_LINK])
 
 
2008		return -EINVAL;
2009
2010	version = nla_get_u32(info->attrs[GTPA_VERSION]);
2011
2012	switch (version) {
2013	case GTP_V0:
2014		if (!info->attrs[GTPA_TID] ||
2015		    !info->attrs[GTPA_FLOW])
2016			return -EINVAL;
2017		break;
2018	case GTP_V1:
2019		if (!info->attrs[GTPA_I_TEI] ||
2020		    !info->attrs[GTPA_O_TEI])
2021			return -EINVAL;
2022		break;
2023
2024	default:
2025		return -EINVAL;
2026	}
2027
2028	rtnl_lock();
 
2029
2030	gtp = gtp_find_dev(sock_net(skb->sk), info->attrs);
2031	if (!gtp) {
2032		err = -ENODEV;
2033		goto out_unlock;
2034	}
2035
2036	if (version == GTP_V0)
2037		sk = gtp->sk0;
2038	else if (version == GTP_V1)
2039		sk = gtp->sk1u;
2040	else
2041		sk = NULL;
2042
2043	if (!sk) {
2044		err = -ENODEV;
2045		goto out_unlock;
2046	}
2047
2048	pctx = gtp_pdp_add(gtp, sk, info);
2049	if (IS_ERR(pctx)) {
2050		err = PTR_ERR(pctx);
2051	} else {
2052		gtp_tunnel_notify(pctx, GTP_CMD_NEWPDP, GFP_KERNEL);
2053		err = 0;
2054	}
2055
2056out_unlock:
 
2057	rtnl_unlock();
2058	return err;
2059}
2060
2061static struct pdp_ctx *gtp_find_pdp_by_link(struct net *net,
2062					    struct nlattr *nla[])
2063{
2064	struct gtp_dev *gtp;
2065	int family;
2066
2067	family = nla_get_u8_default(nla[GTPA_FAMILY], AF_INET);
2068
2069	gtp = gtp_find_dev(net, nla);
2070	if (!gtp)
2071		return ERR_PTR(-ENODEV);
2072
2073	if (nla[GTPA_MS_ADDRESS]) {
2074		__be32 ip = nla_get_be32(nla[GTPA_MS_ADDRESS]);
2075
2076		if (family != AF_INET)
2077			return ERR_PTR(-EINVAL);
2078
2079		return ipv4_pdp_find(gtp, ip);
2080	} else if (nla[GTPA_MS_ADDR6]) {
2081		struct in6_addr addr = nla_get_in6_addr(nla[GTPA_MS_ADDR6]);
2082
2083		if (family != AF_INET6)
2084			return ERR_PTR(-EINVAL);
2085
2086		if (addr.s6_addr32[2] ||
2087		    addr.s6_addr32[3])
2088			return ERR_PTR(-EADDRNOTAVAIL);
2089
2090		return ipv6_pdp_find(gtp, &addr);
2091	} else if (nla[GTPA_VERSION]) {
2092		u32 gtp_version = nla_get_u32(nla[GTPA_VERSION]);
2093
2094		if (gtp_version == GTP_V0 && nla[GTPA_TID]) {
2095			return gtp0_pdp_find(gtp, nla_get_u64(nla[GTPA_TID]),
2096					     family);
2097		} else if (gtp_version == GTP_V1 && nla[GTPA_I_TEI]) {
2098			return gtp1_pdp_find(gtp, nla_get_u32(nla[GTPA_I_TEI]),
2099					     family);
2100		}
2101	}
2102
2103	return ERR_PTR(-EINVAL);
2104}
2105
2106static struct pdp_ctx *gtp_find_pdp(struct net *net, struct nlattr *nla[])
2107{
2108	struct pdp_ctx *pctx;
2109
2110	if (nla[GTPA_LINK])
2111		pctx = gtp_find_pdp_by_link(net, nla);
2112	else
2113		pctx = ERR_PTR(-EINVAL);
2114
2115	if (!pctx)
2116		pctx = ERR_PTR(-ENOENT);
2117
2118	return pctx;
2119}
2120
2121static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info)
2122{
2123	struct pdp_ctx *pctx;
2124	int err = 0;
2125
2126	if (!info->attrs[GTPA_VERSION])
2127		return -EINVAL;
2128
2129	rcu_read_lock();
2130
2131	pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
2132	if (IS_ERR(pctx)) {
2133		err = PTR_ERR(pctx);
2134		goto out_unlock;
2135	}
2136
2137	if (pctx->gtp_version == GTP_V0)
2138		netdev_dbg(pctx->dev, "GTPv0-U: deleting tunnel id = %llx (pdp %p)\n",
2139			   pctx->u.v0.tid, pctx);
2140	else if (pctx->gtp_version == GTP_V1)
2141		netdev_dbg(pctx->dev, "GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n",
2142			   pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
2143
2144	gtp_tunnel_notify(pctx, GTP_CMD_DELPDP, GFP_ATOMIC);
2145	pdp_context_delete(pctx);
2146
2147out_unlock:
2148	rcu_read_unlock();
2149	return err;
2150}
2151
 
 
2152static int gtp_genl_fill_info(struct sk_buff *skb, u32 snd_portid, u32 snd_seq,
2153			      int flags, u32 type, struct pdp_ctx *pctx)
2154{
2155	void *genlh;
2156
2157	genlh = genlmsg_put(skb, snd_portid, snd_seq, &gtp_genl_family, flags,
2158			    type);
2159	if (genlh == NULL)
2160		goto nlmsg_failure;
2161
2162	if (nla_put_u32(skb, GTPA_VERSION, pctx->gtp_version) ||
2163	    nla_put_u32(skb, GTPA_LINK, pctx->dev->ifindex) ||
2164	    nla_put_u8(skb, GTPA_FAMILY, pctx->af))
 
2165		goto nla_put_failure;
2166
2167	switch (pctx->af) {
2168	case AF_INET:
2169		if (nla_put_be32(skb, GTPA_MS_ADDRESS, pctx->ms.addr.s_addr))
2170			goto nla_put_failure;
2171		break;
2172	case AF_INET6:
2173		if (nla_put_in6_addr(skb, GTPA_MS_ADDR6, &pctx->ms.addr6))
2174			goto nla_put_failure;
2175		break;
2176	}
2177
2178	switch (pctx->sk->sk_family) {
2179	case AF_INET:
2180		if (nla_put_be32(skb, GTPA_PEER_ADDRESS, pctx->peer.addr.s_addr))
2181			goto nla_put_failure;
2182		break;
2183	case AF_INET6:
2184		if (nla_put_in6_addr(skb, GTPA_PEER_ADDR6, &pctx->peer.addr6))
2185			goto nla_put_failure;
2186		break;
2187	}
2188
2189	switch (pctx->gtp_version) {
2190	case GTP_V0:
2191		if (nla_put_u64_64bit(skb, GTPA_TID, pctx->u.v0.tid, GTPA_PAD) ||
2192		    nla_put_u16(skb, GTPA_FLOW, pctx->u.v0.flow))
2193			goto nla_put_failure;
2194		break;
2195	case GTP_V1:
2196		if (nla_put_u32(skb, GTPA_I_TEI, pctx->u.v1.i_tei) ||
2197		    nla_put_u32(skb, GTPA_O_TEI, pctx->u.v1.o_tei))
2198			goto nla_put_failure;
2199		break;
2200	}
2201	genlmsg_end(skb, genlh);
2202	return 0;
2203
2204nlmsg_failure:
2205nla_put_failure:
2206	genlmsg_cancel(skb, genlh);
2207	return -EMSGSIZE;
2208}
2209
2210static int gtp_tunnel_notify(struct pdp_ctx *pctx, u8 cmd, gfp_t allocation)
2211{
2212	struct sk_buff *msg;
2213	int ret;
2214
2215	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, allocation);
2216	if (!msg)
2217		return -ENOMEM;
2218
2219	ret = gtp_genl_fill_info(msg, 0, 0, 0, cmd, pctx);
2220	if (ret < 0) {
2221		nlmsg_free(msg);
2222		return ret;
2223	}
2224
2225	ret = genlmsg_multicast_netns(&gtp_genl_family, dev_net(pctx->dev), msg,
2226				      0, GTP_GENL_MCGRP, GFP_ATOMIC);
2227	return ret;
2228}
2229
2230static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info)
2231{
2232	struct pdp_ctx *pctx = NULL;
2233	struct sk_buff *skb2;
2234	int err;
2235
2236	if (!info->attrs[GTPA_VERSION])
2237		return -EINVAL;
2238
2239	rcu_read_lock();
2240
2241	pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
2242	if (IS_ERR(pctx)) {
2243		err = PTR_ERR(pctx);
2244		goto err_unlock;
2245	}
2246
2247	skb2 = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
2248	if (skb2 == NULL) {
2249		err = -ENOMEM;
2250		goto err_unlock;
2251	}
2252
2253	err = gtp_genl_fill_info(skb2, NETLINK_CB(skb).portid, info->snd_seq,
2254				 0, info->nlhdr->nlmsg_type, pctx);
2255	if (err < 0)
2256		goto err_unlock_free;
2257
2258	rcu_read_unlock();
2259	return genlmsg_unicast(genl_info_net(info), skb2, info->snd_portid);
2260
2261err_unlock_free:
2262	kfree_skb(skb2);
2263err_unlock:
2264	rcu_read_unlock();
2265	return err;
2266}
2267
2268static int gtp_genl_dump_pdp(struct sk_buff *skb,
2269				struct netlink_callback *cb)
2270{
2271	struct gtp_dev *last_gtp = (struct gtp_dev *)cb->args[2], *gtp;
2272	int i, j, bucket = cb->args[0], skip = cb->args[1];
2273	struct net *net = sock_net(skb->sk);
2274	struct net_device *dev;
2275	struct pdp_ctx *pctx;
 
 
 
2276
2277	if (cb->args[4])
2278		return 0;
2279
2280	rcu_read_lock();
2281	for_each_netdev_rcu(net, dev) {
2282		if (dev->rtnl_link_ops != &gtp_link_ops)
2283			continue;
2284
2285		gtp = netdev_priv(dev);
2286
2287		if (last_gtp && last_gtp != gtp)
2288			continue;
2289		else
2290			last_gtp = NULL;
2291
2292		for (i = bucket; i < gtp->hash_size; i++) {
2293			j = 0;
2294			hlist_for_each_entry_rcu(pctx, &gtp->tid_hash[i],
2295						 hlist_tid) {
2296				if (j >= skip &&
2297				    gtp_genl_fill_info(skb,
2298					    NETLINK_CB(cb->skb).portid,
2299					    cb->nlh->nlmsg_seq,
2300					    NLM_F_MULTI,
2301					    cb->nlh->nlmsg_type, pctx)) {
2302					cb->args[0] = i;
2303					cb->args[1] = j;
2304					cb->args[2] = (unsigned long)gtp;
2305					goto out;
2306				}
2307				j++;
2308			}
2309			skip = 0;
2310		}
2311		bucket = 0;
2312	}
2313	cb->args[4] = 1;
2314out:
2315	rcu_read_unlock();
2316	return skb->len;
2317}
2318
2319static int gtp_genl_send_echo_req(struct sk_buff *skb, struct genl_info *info)
2320{
2321	struct sk_buff *skb_to_send;
2322	__be32 src_ip, dst_ip;
2323	unsigned int version;
2324	struct gtp_dev *gtp;
2325	struct flowi4 fl4;
2326	struct rtable *rt;
2327	struct sock *sk;
2328	__be16 port;
2329	int len;
2330
2331	if (!info->attrs[GTPA_VERSION] ||
2332	    !info->attrs[GTPA_LINK] ||
2333	    !info->attrs[GTPA_PEER_ADDRESS] ||
2334	    !info->attrs[GTPA_MS_ADDRESS])
2335		return -EINVAL;
2336
2337	version = nla_get_u32(info->attrs[GTPA_VERSION]);
2338	dst_ip = nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]);
2339	src_ip = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
2340
2341	gtp = gtp_find_dev(sock_net(skb->sk), info->attrs);
2342	if (!gtp)
2343		return -ENODEV;
2344
2345	if (!gtp->sk_created)
2346		return -EOPNOTSUPP;
2347	if (!(gtp->dev->flags & IFF_UP))
2348		return -ENETDOWN;
2349
2350	if (version == GTP_V0) {
2351		struct gtp0_header *gtp0_h;
2352
2353		len = LL_RESERVED_SPACE(gtp->dev) + sizeof(struct gtp0_header) +
2354			sizeof(struct iphdr) + sizeof(struct udphdr);
2355
2356		skb_to_send = netdev_alloc_skb_ip_align(gtp->dev, len);
2357		if (!skb_to_send)
2358			return -ENOMEM;
2359
2360		sk = gtp->sk0;
2361		port = htons(GTP0_PORT);
2362
2363		gtp0_h = skb_push(skb_to_send, sizeof(struct gtp0_header));
2364		memset(gtp0_h, 0, sizeof(struct gtp0_header));
2365		gtp0_build_echo_msg(gtp0_h, GTP_ECHO_REQ);
2366	} else if (version == GTP_V1) {
2367		struct gtp1_header_long *gtp1u_h;
2368
2369		len = LL_RESERVED_SPACE(gtp->dev) +
2370			sizeof(struct gtp1_header_long) +
2371			sizeof(struct iphdr) + sizeof(struct udphdr);
2372
2373		skb_to_send = netdev_alloc_skb_ip_align(gtp->dev, len);
2374		if (!skb_to_send)
2375			return -ENOMEM;
2376
2377		sk = gtp->sk1u;
2378		port = htons(GTP1U_PORT);
2379
2380		gtp1u_h = skb_push(skb_to_send,
2381				   sizeof(struct gtp1_header_long));
2382		memset(gtp1u_h, 0, sizeof(struct gtp1_header_long));
2383		gtp1u_build_echo_msg(gtp1u_h, GTP_ECHO_REQ);
2384	} else {
2385		return -ENODEV;
2386	}
2387
2388	rt = ip4_route_output_gtp(&fl4, sk, dst_ip, src_ip);
2389	if (IS_ERR(rt)) {
2390		netdev_dbg(gtp->dev, "no route for echo request to %pI4\n",
2391			   &dst_ip);
2392		kfree_skb(skb_to_send);
2393		return -ENODEV;
2394	}
2395
2396	udp_tunnel_xmit_skb(rt, sk, skb_to_send,
2397			    fl4.saddr, fl4.daddr,
2398			    fl4.flowi4_tos,
2399			    ip4_dst_hoplimit(&rt->dst),
2400			    0,
2401			    port, port,
2402			    !net_eq(sock_net(sk),
2403				    dev_net(gtp->dev)),
2404			    false);
2405	return 0;
2406}
2407
2408static const struct nla_policy gtp_genl_policy[GTPA_MAX + 1] = {
2409	[GTPA_LINK]		= { .type = NLA_U32, },
2410	[GTPA_VERSION]		= { .type = NLA_U32, },
2411	[GTPA_TID]		= { .type = NLA_U64, },
2412	[GTPA_PEER_ADDRESS]	= { .type = NLA_U32, },
2413	[GTPA_MS_ADDRESS]	= { .type = NLA_U32, },
2414	[GTPA_FLOW]		= { .type = NLA_U16, },
2415	[GTPA_NET_NS_FD]	= { .type = NLA_U32, },
2416	[GTPA_I_TEI]		= { .type = NLA_U32, },
2417	[GTPA_O_TEI]		= { .type = NLA_U32, },
2418	[GTPA_PEER_ADDR6]	= { .len = sizeof(struct in6_addr), },
2419	[GTPA_MS_ADDR6]		= { .len = sizeof(struct in6_addr), },
2420	[GTPA_FAMILY]		= { .type = NLA_U8, },
2421};
2422
2423static const struct genl_small_ops gtp_genl_ops[] = {
2424	{
2425		.cmd = GTP_CMD_NEWPDP,
2426		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2427		.doit = gtp_genl_new_pdp,
2428		.flags = GENL_ADMIN_PERM,
2429	},
2430	{
2431		.cmd = GTP_CMD_DELPDP,
2432		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2433		.doit = gtp_genl_del_pdp,
2434		.flags = GENL_ADMIN_PERM,
2435	},
2436	{
2437		.cmd = GTP_CMD_GETPDP,
2438		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2439		.doit = gtp_genl_get_pdp,
2440		.dumpit = gtp_genl_dump_pdp,
2441		.flags = GENL_ADMIN_PERM,
2442	},
2443	{
2444		.cmd = GTP_CMD_ECHOREQ,
2445		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2446		.doit = gtp_genl_send_echo_req,
2447		.flags = GENL_ADMIN_PERM,
2448	},
2449};
2450
2451static struct genl_family gtp_genl_family __ro_after_init = {
2452	.name		= "gtp",
2453	.version	= 0,
2454	.hdrsize	= 0,
2455	.maxattr	= GTPA_MAX,
2456	.policy = gtp_genl_policy,
2457	.netnsok	= true,
2458	.module		= THIS_MODULE,
2459	.small_ops	= gtp_genl_ops,
2460	.n_small_ops	= ARRAY_SIZE(gtp_genl_ops),
2461	.resv_start_op	= GTP_CMD_ECHOREQ + 1,
2462	.mcgrps		= gtp_genl_mcgrps,
2463	.n_mcgrps	= ARRAY_SIZE(gtp_genl_mcgrps),
2464};
2465
2466static int __net_init gtp_net_init(struct net *net)
2467{
2468	struct gtp_net *gn = net_generic(net, gtp_net_id);
2469
2470	INIT_LIST_HEAD(&gn->gtp_dev_list);
2471	return 0;
2472}
2473
2474static void __net_exit gtp_net_exit_batch_rtnl(struct list_head *net_list,
2475					       struct list_head *dev_to_kill)
2476{
2477	struct net *net;
 
 
2478
2479	list_for_each_entry(net, net_list, exit_list) {
2480		struct gtp_net *gn = net_generic(net, gtp_net_id);
2481		struct gtp_dev *gtp, *gtp_next;
2482
2483		list_for_each_entry_safe(gtp, gtp_next, &gn->gtp_dev_list, list)
2484			gtp_dellink(gtp->dev, dev_to_kill);
2485	}
2486}
2487
2488static struct pernet_operations gtp_net_ops = {
2489	.init	= gtp_net_init,
2490	.exit_batch_rtnl = gtp_net_exit_batch_rtnl,
2491	.id	= &gtp_net_id,
2492	.size	= sizeof(struct gtp_net),
2493};
2494
2495static int __init gtp_init(void)
2496{
2497	int err;
2498
2499	get_random_bytes(&gtp_h_initval, sizeof(gtp_h_initval));
2500
2501	err = register_pernet_subsys(&gtp_net_ops);
2502	if (err < 0)
2503		goto error_out;
2504
2505	err = rtnl_link_register(&gtp_link_ops);
2506	if (err < 0)
2507		goto unreg_pernet_subsys;
2508
2509	err = genl_register_family(&gtp_genl_family);
2510	if (err < 0)
2511		goto unreg_rtnl_link;
2512
 
 
 
 
2513	pr_info("GTP module loaded (pdp ctx size %zd bytes)\n",
2514		sizeof(struct pdp_ctx));
2515	return 0;
2516
 
 
2517unreg_rtnl_link:
2518	rtnl_link_unregister(&gtp_link_ops);
2519unreg_pernet_subsys:
2520	unregister_pernet_subsys(&gtp_net_ops);
2521error_out:
2522	pr_err("error loading GTP module loaded\n");
2523	return err;
2524}
2525late_initcall(gtp_init);
2526
2527static void __exit gtp_fini(void)
2528{
2529	genl_unregister_family(&gtp_genl_family);
2530	rtnl_link_unregister(&gtp_link_ops);
2531	unregister_pernet_subsys(&gtp_net_ops);
2532
2533	pr_info("GTP module unloaded\n");
2534}
2535module_exit(gtp_fini);
2536
2537MODULE_LICENSE("GPL");
2538MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>");
2539MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic");
2540MODULE_ALIAS_RTNL_LINK("gtp");
2541MODULE_ALIAS_GENL_FAMILY("gtp");