1// SPDX-License-Identifier: GPL-2.0-or-later
   2/* SCTP kernel implementation
   3 * (C) Copyright IBM Corp. 2001, 2004
   4 * Copyright (c) 1999-2000 Cisco, Inc.
   5 * Copyright (c) 1999-2001 Motorola, Inc.
   6 * Copyright (c) 2001 Intel Corp.
   7 * Copyright (c) 2001 Nokia, Inc.
   8 * Copyright (c) 2001 La Monte H.P. Yarroll
   9 *
  10 * This file is part of the SCTP kernel implementation
  11 *
  12 * Initialization/cleanup for SCTP protocol support.
  13 *
  14 * Please send any bug reports or fixes you make to the
  15 * email address(es):
  16 *    lksctp developers <linux-sctp@vger.kernel.org>
  17 *
  18 * Written or modified by:
  19 *    La Monte H.P. Yarroll <piggy@acm.org>
  20 *    Karl Knutson <karl@athena.chicago.il.us>
  21 *    Jon Grimm <jgrimm@us.ibm.com>
  22 *    Sridhar Samudrala <sri@us.ibm.com>
  23 *    Daisy Chang <daisyc@us.ibm.com>
  24 *    Ardelle Fan <ardelle.fan@intel.com>
  25 */
  26
  27#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  28
  29#include <linux/module.h>
  30#include <linux/init.h>
  31#include <linux/netdevice.h>
  32#include <linux/inetdevice.h>
  33#include <linux/seq_file.h>
  34#include <linux/memblock.h>
  35#include <linux/highmem.h>
 
  36#include <linux/slab.h>
  37#include <net/net_namespace.h>
  38#include <net/protocol.h>
  39#include <net/ip.h>
  40#include <net/ipv6.h>
  41#include <net/route.h>
  42#include <net/sctp/sctp.h>
  43#include <net/addrconf.h>
  44#include <net/inet_common.h>
  45#include <net/inet_ecn.h>
  46#include <net/udp_tunnel.h>
  47#include <net/inet_dscp.h>
  48
  49#define MAX_SCTP_PORT_HASH_ENTRIES (64 * 1024)
  50
  51/* Global data structures. */
  52struct sctp_globals sctp_globals __read_mostly;
  53
  54struct idr sctp_assocs_id;
  55DEFINE_SPINLOCK(sctp_assocs_id_lock);
  56
  57static struct sctp_pf *sctp_pf_inet6_specific;
  58static struct sctp_pf *sctp_pf_inet_specific;
  59static struct sctp_af *sctp_af_v4_specific;
  60static struct sctp_af *sctp_af_v6_specific;
  61
  62struct kmem_cache *sctp_chunk_cachep __read_mostly;
  63struct kmem_cache *sctp_bucket_cachep __read_mostly;
  64
  65long sysctl_sctp_mem[3];
  66int sysctl_sctp_rmem[3];
  67int sysctl_sctp_wmem[3];
  68
  69/* Private helper to extract ipv4 address and stash them in
  70 * the protocol structure.
  71 */
  72static void sctp_v4_copy_addrlist(struct list_head *addrlist,
  73				  struct net_device *dev)
  74{
  75	struct in_device *in_dev;
  76	struct in_ifaddr *ifa;
  77	struct sctp_sockaddr_entry *addr;
  78
  79	rcu_read_lock();
  80	if ((in_dev = __in_dev_get_rcu(dev)) == NULL) {
  81		rcu_read_unlock();
  82		return;
  83	}
  84
  85	in_dev_for_each_ifa_rcu(ifa, in_dev) {
  86		/* Add the address to the local list.  */
  87		addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
  88		if (addr) {
  89			addr->a.v4.sin_family = AF_INET;
  90			addr->a.v4.sin_addr.s_addr = ifa->ifa_local;
  91			addr->valid = 1;
  92			INIT_LIST_HEAD(&addr->list);
  93			list_add_tail(&addr->list, addrlist);
  94		}
  95	}
  96
  97	rcu_read_unlock();
  98}
  99
 100/* Extract our IP addresses from the system and stash them in the
 101 * protocol structure.
 102 */
 103static void sctp_get_local_addr_list(struct net *net)
 104{
 105	struct net_device *dev;
 106	struct list_head *pos;
 107	struct sctp_af *af;
 108
 109	rcu_read_lock();
 110	for_each_netdev_rcu(net, dev) {
 111		list_for_each(pos, &sctp_address_families) {
 112			af = list_entry(pos, struct sctp_af, list);
 113			af->copy_addrlist(&net->sctp.local_addr_list, dev);
 114		}
 115	}
 116	rcu_read_unlock();
 117}
 118
 119/* Free the existing local addresses.  */
 120static void sctp_free_local_addr_list(struct net *net)
 121{
 122	struct sctp_sockaddr_entry *addr;
 123	struct list_head *pos, *temp;
 124
 125	list_for_each_safe(pos, temp, &net->sctp.local_addr_list) {
 126		addr = list_entry(pos, struct sctp_sockaddr_entry, list);
 127		list_del(pos);
 128		kfree(addr);
 129	}
 130}
 131
 132/* Copy the local addresses which are valid for 'scope' into 'bp'.  */
 133int sctp_copy_local_addr_list(struct net *net, struct sctp_bind_addr *bp,
 134			      enum sctp_scope scope, gfp_t gfp, int copy_flags)
 135{
 136	struct sctp_sockaddr_entry *addr;
 137	union sctp_addr laddr;
 138	int error = 0;
 139
 140	rcu_read_lock();
 141	list_for_each_entry_rcu(addr, &net->sctp.local_addr_list, list) {
 142		if (!addr->valid)
 143			continue;
 144		if (!sctp_in_scope(net, &addr->a, scope))
 145			continue;
 146
 147		/* Now that the address is in scope, check to see if
 148		 * the address type is really supported by the local
 149		 * sock as well as the remote peer.
 150		 */
 151		if (addr->a.sa.sa_family == AF_INET &&
 152		    (!(copy_flags & SCTP_ADDR4_ALLOWED) ||
 153		     !(copy_flags & SCTP_ADDR4_PEERSUPP)))
 154			continue;
 155		if (addr->a.sa.sa_family == AF_INET6 &&
 156		    (!(copy_flags & SCTP_ADDR6_ALLOWED) ||
 157		     !(copy_flags & SCTP_ADDR6_PEERSUPP)))
 158			continue;
 159
 160		laddr = addr->a;
 161		/* also works for setting ipv6 address port */
 162		laddr.v4.sin_port = htons(bp->port);
 163		if (sctp_bind_addr_state(bp, &laddr) != -1)
 164			continue;
 165
 166		error = sctp_add_bind_addr(bp, &addr->a, sizeof(addr->a),
 167					   SCTP_ADDR_SRC, GFP_ATOMIC);
 168		if (error)
 169			break;
 170	}
 171
 172	rcu_read_unlock();
 173	return error;
 174}
 175
 176/* Copy over any ip options */
 177static void sctp_v4_copy_ip_options(struct sock *sk, struct sock *newsk)
 178{
 179	struct inet_sock *newinet, *inet = inet_sk(sk);
 180	struct ip_options_rcu *inet_opt, *newopt = NULL;
 181
 182	newinet = inet_sk(newsk);
 183
 184	rcu_read_lock();
 185	inet_opt = rcu_dereference(inet->inet_opt);
 186	if (inet_opt) {
 187		newopt = sock_kmalloc(newsk, sizeof(*inet_opt) +
 188				      inet_opt->opt.optlen, GFP_ATOMIC);
 189		if (newopt)
 190			memcpy(newopt, inet_opt, sizeof(*inet_opt) +
 191			       inet_opt->opt.optlen);
 192		else
 193			pr_err("%s: Failed to copy ip options\n", __func__);
 194	}
 195	RCU_INIT_POINTER(newinet->inet_opt, newopt);
 196	rcu_read_unlock();
 197}
 198
 199/* Account for the IP options */
 200static int sctp_v4_ip_options_len(struct sock *sk)
 201{
 202	struct inet_sock *inet = inet_sk(sk);
 203	struct ip_options_rcu *inet_opt;
 204	int len = 0;
 205
 206	rcu_read_lock();
 207	inet_opt = rcu_dereference(inet->inet_opt);
 208	if (inet_opt)
 209		len = inet_opt->opt.optlen;
 210
 211	rcu_read_unlock();
 212	return len;
 213}
 214
 215/* Initialize a sctp_addr from in incoming skb.  */
 216static void sctp_v4_from_skb(union sctp_addr *addr, struct sk_buff *skb,
 217			     int is_saddr)
 218{
 219	/* Always called on head skb, so this is safe */
 220	struct sctphdr *sh = sctp_hdr(skb);
 221	struct sockaddr_in *sa = &addr->v4;
 222
 223	addr->v4.sin_family = AF_INET;
 224
 225	if (is_saddr) {
 226		sa->sin_port = sh->source;
 227		sa->sin_addr.s_addr = ip_hdr(skb)->saddr;
 228	} else {
 229		sa->sin_port = sh->dest;
 230		sa->sin_addr.s_addr = ip_hdr(skb)->daddr;
 231	}
 232	memset(sa->sin_zero, 0, sizeof(sa->sin_zero));
 233}
 234
 235/* Initialize an sctp_addr from a socket. */
 236static void sctp_v4_from_sk(union sctp_addr *addr, struct sock *sk)
 237{
 238	addr->v4.sin_family = AF_INET;
 239	addr->v4.sin_port = 0;
 240	addr->v4.sin_addr.s_addr = inet_sk(sk)->inet_rcv_saddr;
 241	memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
 242}
 243
 244/* Initialize sk->sk_rcv_saddr from sctp_addr. */
 245static void sctp_v4_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 246{
 247	inet_sk(sk)->inet_rcv_saddr = addr->v4.sin_addr.s_addr;
 248}
 249
 250/* Initialize sk->sk_daddr from sctp_addr. */
 251static void sctp_v4_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 252{
 253	inet_sk(sk)->inet_daddr = addr->v4.sin_addr.s_addr;
 254}
 255
 256/* Initialize a sctp_addr from an address parameter. */
 257static bool sctp_v4_from_addr_param(union sctp_addr *addr,
 258				    union sctp_addr_param *param,
 259				    __be16 port, int iif)
 260{
 261	if (ntohs(param->v4.param_hdr.length) < sizeof(struct sctp_ipv4addr_param))
 262		return false;
 263
 264	addr->v4.sin_family = AF_INET;
 265	addr->v4.sin_port = port;
 266	addr->v4.sin_addr.s_addr = param->v4.addr.s_addr;
 267	memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
 268
 269	return true;
 270}
 271
 272/* Initialize an address parameter from a sctp_addr and return the length
 273 * of the address parameter.
 274 */
 275static int sctp_v4_to_addr_param(const union sctp_addr *addr,
 276				 union sctp_addr_param *param)
 277{
 278	int length = sizeof(struct sctp_ipv4addr_param);
 279
 280	param->v4.param_hdr.type = SCTP_PARAM_IPV4_ADDRESS;
 281	param->v4.param_hdr.length = htons(length);
 282	param->v4.addr.s_addr = addr->v4.sin_addr.s_addr;
 283
 284	return length;
 285}
 286
 287/* Initialize a sctp_addr from a dst_entry. */
 288static void sctp_v4_dst_saddr(union sctp_addr *saddr, struct flowi4 *fl4,
 289			      __be16 port)
 290{
 291	saddr->v4.sin_family = AF_INET;
 292	saddr->v4.sin_port = port;
 293	saddr->v4.sin_addr.s_addr = fl4->saddr;
 294	memset(saddr->v4.sin_zero, 0, sizeof(saddr->v4.sin_zero));
 295}
 296
 297/* Compare two addresses exactly. */
 298static int sctp_v4_cmp_addr(const union sctp_addr *addr1,
 299			    const union sctp_addr *addr2)
 300{
 301	if (addr1->sa.sa_family != addr2->sa.sa_family)
 302		return 0;
 303	if (addr1->v4.sin_port != addr2->v4.sin_port)
 304		return 0;
 305	if (addr1->v4.sin_addr.s_addr != addr2->v4.sin_addr.s_addr)
 306		return 0;
 307
 308	return 1;
 309}
 310
 311/* Initialize addr struct to INADDR_ANY. */
 312static void sctp_v4_inaddr_any(union sctp_addr *addr, __be16 port)
 313{
 314	addr->v4.sin_family = AF_INET;
 315	addr->v4.sin_addr.s_addr = htonl(INADDR_ANY);
 316	addr->v4.sin_port = port;
 317	memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
 318}
 319
 320/* Is this a wildcard address? */
 321static int sctp_v4_is_any(const union sctp_addr *addr)
 322{
 323	return htonl(INADDR_ANY) == addr->v4.sin_addr.s_addr;
 324}
 325
 326/* This function checks if the address is a valid address to be used for
 327 * SCTP binding.
 328 *
 329 * Output:
 330 * Return 0 - If the address is a non-unicast or an illegal address.
 331 * Return 1 - If the address is a unicast.
 332 */
 333static int sctp_v4_addr_valid(union sctp_addr *addr,
 334			      struct sctp_sock *sp,
 335			      const struct sk_buff *skb)
 336{
 337	/* IPv4 addresses not allowed */
 338	if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 339		return 0;
 340
 341	/* Is this a non-unicast address or a unusable SCTP address? */
 342	if (IS_IPV4_UNUSABLE_ADDRESS(addr->v4.sin_addr.s_addr))
 343		return 0;
 344
 345	/* Is this a broadcast address? */
 346	if (skb && skb_rtable(skb)->rt_flags & RTCF_BROADCAST)
 347		return 0;
 348
 349	return 1;
 350}
 351
 352/* Should this be available for binding?   */
 353static int sctp_v4_available(union sctp_addr *addr, struct sctp_sock *sp)
 354{
 355	struct sock *sk = &sp->inet.sk;
 356	struct net *net = sock_net(sk);
 357	int tb_id = RT_TABLE_LOCAL;
 358	int ret;
 359
 360	tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ?: tb_id;
 361	ret = inet_addr_type_table(net, addr->v4.sin_addr.s_addr, tb_id);
 362	if (addr->v4.sin_addr.s_addr != htonl(INADDR_ANY) &&
 363	   ret != RTN_LOCAL &&
 364	   !inet_test_bit(FREEBIND, sk) &&
 365	    !READ_ONCE(net->ipv4.sysctl_ip_nonlocal_bind))
 366		return 0;
 367
 368	if (ipv6_only_sock(sctp_opt2sk(sp)))
 369		return 0;
 370
 371	return 1;
 372}
 373
 374/* Checking the loopback, private and other address scopes as defined in
 375 * RFC 1918.   The IPv4 scoping is based on the draft for SCTP IPv4
 376 * scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>.
 377 *
 378 * Level 0 - unusable SCTP addresses
 379 * Level 1 - loopback address
 380 * Level 2 - link-local addresses
 381 * Level 3 - private addresses.
 382 * Level 4 - global addresses
 383 * For INIT and INIT-ACK address list, let L be the level of
 384 * requested destination address, sender and receiver
 385 * SHOULD include all of its addresses with level greater
 386 * than or equal to L.
 387 *
 388 * IPv4 scoping can be controlled through sysctl option
 389 * net.sctp.addr_scope_policy
 390 */
 391static enum sctp_scope sctp_v4_scope(union sctp_addr *addr)
 392{
 393	enum sctp_scope retval;
 394
 395	/* Check for unusable SCTP addresses. */
 396	if (IS_IPV4_UNUSABLE_ADDRESS(addr->v4.sin_addr.s_addr)) {
 397		retval =  SCTP_SCOPE_UNUSABLE;
 398	} else if (ipv4_is_loopback(addr->v4.sin_addr.s_addr)) {
 399		retval = SCTP_SCOPE_LOOPBACK;
 400	} else if (ipv4_is_linklocal_169(addr->v4.sin_addr.s_addr)) {
 401		retval = SCTP_SCOPE_LINK;
 402	} else if (ipv4_is_private_10(addr->v4.sin_addr.s_addr) ||
 403		   ipv4_is_private_172(addr->v4.sin_addr.s_addr) ||
 404		   ipv4_is_private_192(addr->v4.sin_addr.s_addr) ||
 405		   ipv4_is_test_198(addr->v4.sin_addr.s_addr)) {
 406		retval = SCTP_SCOPE_PRIVATE;
 407	} else {
 408		retval = SCTP_SCOPE_GLOBAL;
 409	}
 410
 411	return retval;
 412}
 413
 414/* Returns a valid dst cache entry for the given source and destination ip
 415 * addresses. If an association is passed, trys to get a dst entry with a
 416 * source address that matches an address in the bind address list.
 417 */
 418static void sctp_v4_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
 419				struct flowi *fl, struct sock *sk)
 420{
 421	struct sctp_association *asoc = t->asoc;
 422	struct rtable *rt;
 423	struct flowi _fl;
 424	struct flowi4 *fl4 = &_fl.u.ip4;
 425	struct sctp_bind_addr *bp;
 426	struct sctp_sockaddr_entry *laddr;
 427	struct dst_entry *dst = NULL;
 428	union sctp_addr *daddr = &t->ipaddr;
 429	union sctp_addr dst_saddr;
 430	u8 tos = READ_ONCE(inet_sk(sk)->tos);
 431
 432	if (t->dscp & SCTP_DSCP_SET_MASK)
 433		tos = t->dscp & SCTP_DSCP_VAL_MASK;
 434	memset(&_fl, 0x0, sizeof(_fl));
 435	fl4->daddr  = daddr->v4.sin_addr.s_addr;
 436	fl4->fl4_dport = daddr->v4.sin_port;
 437	fl4->flowi4_proto = IPPROTO_SCTP;
 438	if (asoc) {
 439		fl4->flowi4_tos = tos & INET_DSCP_MASK;
 440		fl4->flowi4_scope = ip_sock_rt_scope(asoc->base.sk);
 441		fl4->flowi4_oif = asoc->base.sk->sk_bound_dev_if;
 442		fl4->fl4_sport = htons(asoc->base.bind_addr.port);
 443	}
 444	if (saddr) {
 445		fl4->saddr = saddr->v4.sin_addr.s_addr;
 446		if (!fl4->fl4_sport)
 447			fl4->fl4_sport = saddr->v4.sin_port;
 448	}
 449
 450	pr_debug("%s: dst:%pI4, src:%pI4 - ", __func__, &fl4->daddr,
 451		 &fl4->saddr);
 452
 453	rt = ip_route_output_key(sock_net(sk), fl4);
 454	if (!IS_ERR(rt)) {
 455		dst = &rt->dst;
 456		t->dst = dst;
 457		memcpy(fl, &_fl, sizeof(_fl));
 458	}
 459
 460	/* If there is no association or if a source address is passed, no
 461	 * more validation is required.
 462	 */
 463	if (!asoc || saddr)
 464		goto out;
 465
 466	bp = &asoc->base.bind_addr;
 467
 468	if (dst) {
 469		/* Walk through the bind address list and look for a bind
 470		 * address that matches the source address of the returned dst.
 471		 */
 472		sctp_v4_dst_saddr(&dst_saddr, fl4, htons(bp->port));
 473		rcu_read_lock();
 474		list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 475			if (!laddr->valid || (laddr->state == SCTP_ADDR_DEL) ||
 476			    (laddr->state != SCTP_ADDR_SRC &&
 477			    !asoc->src_out_of_asoc_ok))
 478				continue;
 479			if (sctp_v4_cmp_addr(&dst_saddr, &laddr->a))
 480				goto out_unlock;
 481		}
 482		rcu_read_unlock();
 483
 484		/* None of the bound addresses match the source address of the
 485		 * dst. So release it.
 486		 */
 487		dst_release(dst);
 488		dst = NULL;
 489	}
 490
 491	/* Walk through the bind address list and try to get a dst that
 492	 * matches a bind address as the source address.
 493	 */
 494	rcu_read_lock();
 495	list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 496		struct net_device *odev;
 497
 498		if (!laddr->valid)
 499			continue;
 500		if (laddr->state != SCTP_ADDR_SRC ||
 501		    AF_INET != laddr->a.sa.sa_family)
 502			continue;
 503
 504		fl4->fl4_sport = laddr->a.v4.sin_port;
 505		flowi4_update_output(fl4, asoc->base.sk->sk_bound_dev_if,
 
 
 506				     daddr->v4.sin_addr.s_addr,
 507				     laddr->a.v4.sin_addr.s_addr);
 508
 509		rt = ip_route_output_key(sock_net(sk), fl4);
 510		if (IS_ERR(rt))
 511			continue;
 512
 513		/* Ensure the src address belongs to the output
 514		 * interface.
 515		 */
 516		odev = __ip_dev_find(sock_net(sk), laddr->a.v4.sin_addr.s_addr,
 517				     false);
 518		if (!odev || odev->ifindex != fl4->flowi4_oif) {
 519			if (!dst) {
 520				dst = &rt->dst;
 521				t->dst = dst;
 522				memcpy(fl, &_fl, sizeof(_fl));
 523			} else {
 524				dst_release(&rt->dst);
 525			}
 526			continue;
 527		}
 528
 529		dst_release(dst);
 530		dst = &rt->dst;
 531		t->dst = dst;
 532		memcpy(fl, &_fl, sizeof(_fl));
 533		break;
 534	}
 535
 536out_unlock:
 537	rcu_read_unlock();
 538out:
 539	if (dst) {
 540		pr_debug("rt_dst:%pI4, rt_src:%pI4\n",
 541			 &fl->u.ip4.daddr, &fl->u.ip4.saddr);
 542	} else {
 543		t->dst = NULL;
 544		pr_debug("no route\n");
 545	}
 546}
 547
 548/* For v4, the source address is cached in the route entry(dst). So no need
 549 * to cache it separately and hence this is an empty routine.
 550 */
 551static void sctp_v4_get_saddr(struct sctp_sock *sk,
 552			      struct sctp_transport *t,
 553			      struct flowi *fl)
 554{
 555	union sctp_addr *saddr = &t->saddr;
 556	struct rtable *rt = dst_rtable(t->dst);
 557
 558	if (rt) {
 559		saddr->v4.sin_family = AF_INET;
 560		saddr->v4.sin_addr.s_addr = fl->u.ip4.saddr;
 561	}
 562}
 563
 564/* What interface did this skb arrive on? */
 565static int sctp_v4_skb_iif(const struct sk_buff *skb)
 566{
 567	return inet_iif(skb);
 568}
 569
 570static int sctp_v4_skb_sdif(const struct sk_buff *skb)
 571{
 572	return inet_sdif(skb);
 573}
 574
 575/* Was this packet marked by Explicit Congestion Notification? */
 576static int sctp_v4_is_ce(const struct sk_buff *skb)
 577{
 578	return INET_ECN_is_ce(ip_hdr(skb)->tos);
 579}
 580
 581/* Create and initialize a new sk for the socket returned by accept(). */
 582static struct sock *sctp_v4_create_accept_sk(struct sock *sk,
 583					     struct sctp_association *asoc,
 584					     bool kern)
 585{
 586	struct sock *newsk = sk_alloc(sock_net(sk), PF_INET, GFP_KERNEL,
 587			sk->sk_prot, kern);
 588	struct inet_sock *newinet;
 589
 590	if (!newsk)
 591		goto out;
 592
 593	sock_init_data(NULL, newsk);
 594
 595	sctp_copy_sock(newsk, sk, asoc);
 596	sock_reset_flag(newsk, SOCK_ZAPPED);
 597
 598	sctp_v4_copy_ip_options(sk, newsk);
 599
 600	newinet = inet_sk(newsk);
 601
 602	newinet->inet_daddr = asoc->peer.primary_addr.v4.sin_addr.s_addr;
 603
 
 
 604	if (newsk->sk_prot->init(newsk)) {
 605		sk_common_release(newsk);
 606		newsk = NULL;
 607	}
 608
 609out:
 610	return newsk;
 611}
 612
 613static int sctp_v4_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
 614{
 615	/* No address mapping for V4 sockets */
 616	memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
 617	return sizeof(struct sockaddr_in);
 618}
 619
 620/* Dump the v4 addr to the seq file. */
 621static void sctp_v4_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 622{
 623	seq_printf(seq, "%pI4 ", &addr->v4.sin_addr);
 624}
 625
 626static void sctp_v4_ecn_capable(struct sock *sk)
 627{
 628	INET_ECN_xmit(sk);
 629}
 630
 631static void sctp_addr_wq_timeout_handler(struct timer_list *t)
 632{
 633	struct net *net = from_timer(net, t, sctp.addr_wq_timer);
 634	struct sctp_sockaddr_entry *addrw, *temp;
 635	struct sctp_sock *sp;
 636
 637	spin_lock_bh(&net->sctp.addr_wq_lock);
 638
 639	list_for_each_entry_safe(addrw, temp, &net->sctp.addr_waitq, list) {
 640		pr_debug("%s: the first ent in wq:%p is addr:%pISc for cmd:%d at "
 641			 "entry:%p\n", __func__, &net->sctp.addr_waitq, &addrw->a.sa,
 642			 addrw->state, addrw);
 643
 644#if IS_ENABLED(CONFIG_IPV6)
 645		/* Now we send an ASCONF for each association */
 646		/* Note. we currently don't handle link local IPv6 addressees */
 647		if (addrw->a.sa.sa_family == AF_INET6) {
 648			struct in6_addr *in6;
 649
 650			if (ipv6_addr_type(&addrw->a.v6.sin6_addr) &
 651			    IPV6_ADDR_LINKLOCAL)
 652				goto free_next;
 653
 654			in6 = (struct in6_addr *)&addrw->a.v6.sin6_addr;
 655			if (ipv6_chk_addr(net, in6, NULL, 0) == 0 &&
 656			    addrw->state == SCTP_ADDR_NEW) {
 657				unsigned long timeo_val;
 658
 659				pr_debug("%s: this is on DAD, trying %d sec "
 660					 "later\n", __func__,
 661					 SCTP_ADDRESS_TICK_DELAY);
 662
 663				timeo_val = jiffies;
 664				timeo_val += msecs_to_jiffies(SCTP_ADDRESS_TICK_DELAY);
 665				mod_timer(&net->sctp.addr_wq_timer, timeo_val);
 666				break;
 667			}
 668		}
 669#endif
 670		list_for_each_entry(sp, &net->sctp.auto_asconf_splist, auto_asconf_list) {
 671			struct sock *sk;
 672
 673			sk = sctp_opt2sk(sp);
 674			/* ignore bound-specific endpoints */
 675			if (!sctp_is_ep_boundall(sk))
 676				continue;
 677			bh_lock_sock(sk);
 678			if (sctp_asconf_mgmt(sp, addrw) < 0)
 679				pr_debug("%s: sctp_asconf_mgmt failed\n", __func__);
 680			bh_unlock_sock(sk);
 681		}
 682#if IS_ENABLED(CONFIG_IPV6)
 683free_next:
 684#endif
 685		list_del(&addrw->list);
 686		kfree(addrw);
 687	}
 688	spin_unlock_bh(&net->sctp.addr_wq_lock);
 689}
 690
 691static void sctp_free_addr_wq(struct net *net)
 692{
 693	struct sctp_sockaddr_entry *addrw;
 694	struct sctp_sockaddr_entry *temp;
 695
 696	spin_lock_bh(&net->sctp.addr_wq_lock);
 697	del_timer(&net->sctp.addr_wq_timer);
 698	list_for_each_entry_safe(addrw, temp, &net->sctp.addr_waitq, list) {
 699		list_del(&addrw->list);
 700		kfree(addrw);
 701	}
 702	spin_unlock_bh(&net->sctp.addr_wq_lock);
 703}
 704
 705/* lookup the entry for the same address in the addr_waitq
 706 * sctp_addr_wq MUST be locked
 707 */
 708static struct sctp_sockaddr_entry *sctp_addr_wq_lookup(struct net *net,
 709					struct sctp_sockaddr_entry *addr)
 710{
 711	struct sctp_sockaddr_entry *addrw;
 712
 713	list_for_each_entry(addrw, &net->sctp.addr_waitq, list) {
 714		if (addrw->a.sa.sa_family != addr->a.sa.sa_family)
 715			continue;
 716		if (addrw->a.sa.sa_family == AF_INET) {
 717			if (addrw->a.v4.sin_addr.s_addr ==
 718			    addr->a.v4.sin_addr.s_addr)
 719				return addrw;
 720		} else if (addrw->a.sa.sa_family == AF_INET6) {
 721			if (ipv6_addr_equal(&addrw->a.v6.sin6_addr,
 722			    &addr->a.v6.sin6_addr))
 723				return addrw;
 724		}
 725	}
 726	return NULL;
 727}
 728
 729void sctp_addr_wq_mgmt(struct net *net, struct sctp_sockaddr_entry *addr, int cmd)
 730{
 731	struct sctp_sockaddr_entry *addrw;
 732	unsigned long timeo_val;
 733
 734	/* first, we check if an opposite message already exist in the queue.
 735	 * If we found such message, it is removed.
 736	 * This operation is a bit stupid, but the DHCP client attaches the
 737	 * new address after a couple of addition and deletion of that address
 738	 */
 739
 740	spin_lock_bh(&net->sctp.addr_wq_lock);
 741
 742	/* Avoid searching the queue or modifying it if there are no consumers,
 743	 * as it can lead to performance degradation if addresses are modified
 744	 * en-masse.
 745	 *
 746	 * If the queue already contains some events, update it anyway to avoid
 747	 * ugly races between new sessions and new address events.
 748	 */
 749	if (list_empty(&net->sctp.auto_asconf_splist) &&
 750	    list_empty(&net->sctp.addr_waitq)) {
 751		spin_unlock_bh(&net->sctp.addr_wq_lock);
 752		return;
 753	}
 754
 755	/* Offsets existing events in addr_wq */
 756	addrw = sctp_addr_wq_lookup(net, addr);
 757	if (addrw) {
 758		if (addrw->state != cmd) {
 759			pr_debug("%s: offsets existing entry for %d, addr:%pISc "
 760				 "in wq:%p\n", __func__, addrw->state, &addrw->a.sa,
 761				 &net->sctp.addr_waitq);
 762
 763			list_del(&addrw->list);
 764			kfree(addrw);
 765		}
 766		spin_unlock_bh(&net->sctp.addr_wq_lock);
 767		return;
 768	}
 769
 770	/* OK, we have to add the new address to the wait queue */
 771	addrw = kmemdup(addr, sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
 772	if (addrw == NULL) {
 773		spin_unlock_bh(&net->sctp.addr_wq_lock);
 774		return;
 775	}
 776	addrw->state = cmd;
 777	list_add_tail(&addrw->list, &net->sctp.addr_waitq);
 778
 779	pr_debug("%s: add new entry for cmd:%d, addr:%pISc in wq:%p\n",
 780		 __func__, addrw->state, &addrw->a.sa, &net->sctp.addr_waitq);
 781
 782	if (!timer_pending(&net->sctp.addr_wq_timer)) {
 783		timeo_val = jiffies;
 784		timeo_val += msecs_to_jiffies(SCTP_ADDRESS_TICK_DELAY);
 785		mod_timer(&net->sctp.addr_wq_timer, timeo_val);
 786	}
 787	spin_unlock_bh(&net->sctp.addr_wq_lock);
 788}
 789
 790/* Event handler for inet address addition/deletion events.
 791 * The sctp_local_addr_list needs to be protocted by a spin lock since
 792 * multiple notifiers (say IPv4 and IPv6) may be running at the same
 793 * time and thus corrupt the list.
 794 * The reader side is protected with RCU.
 795 */
 796static int sctp_inetaddr_event(struct notifier_block *this, unsigned long ev,
 797			       void *ptr)
 798{
 799	struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
 800	struct sctp_sockaddr_entry *addr = NULL;
 801	struct sctp_sockaddr_entry *temp;
 802	struct net *net = dev_net(ifa->ifa_dev->dev);
 803	int found = 0;
 804
 805	switch (ev) {
 806	case NETDEV_UP:
 807		addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
 808		if (addr) {
 809			addr->a.v4.sin_family = AF_INET;
 810			addr->a.v4.sin_addr.s_addr = ifa->ifa_local;
 811			addr->valid = 1;
 812			spin_lock_bh(&net->sctp.local_addr_lock);
 813			list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
 814			sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
 815			spin_unlock_bh(&net->sctp.local_addr_lock);
 816		}
 817		break;
 818	case NETDEV_DOWN:
 819		spin_lock_bh(&net->sctp.local_addr_lock);
 820		list_for_each_entry_safe(addr, temp,
 821					&net->sctp.local_addr_list, list) {
 822			if (addr->a.sa.sa_family == AF_INET &&
 823					addr->a.v4.sin_addr.s_addr ==
 824					ifa->ifa_local) {
 
 825				found = 1;
 826				addr->valid = 0;
 827				list_del_rcu(&addr->list);
 828				sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
 829				break;
 830			}
 831		}
 832		spin_unlock_bh(&net->sctp.local_addr_lock);
 833		if (found)
 834			kfree_rcu(addr, rcu);
 835		break;
 836	}
 837
 838	return NOTIFY_DONE;
 839}
 840
 841/*
 842 * Initialize the control inode/socket with a control endpoint data
 843 * structure.  This endpoint is reserved exclusively for the OOTB processing.
 844 */
 845static int sctp_ctl_sock_init(struct net *net)
 846{
 847	int err;
 848	sa_family_t family = PF_INET;
 849
 850	if (sctp_get_pf_specific(PF_INET6))
 851		family = PF_INET6;
 852
 853	err = inet_ctl_sock_create(&net->sctp.ctl_sock, family,
 854				   SOCK_SEQPACKET, IPPROTO_SCTP, net);
 855
 856	/* If IPv6 socket could not be created, try the IPv4 socket */
 857	if (err < 0 && family == PF_INET6)
 858		err = inet_ctl_sock_create(&net->sctp.ctl_sock, AF_INET,
 859					   SOCK_SEQPACKET, IPPROTO_SCTP,
 860					   net);
 861
 862	if (err < 0) {
 863		pr_err("Failed to create the SCTP control socket\n");
 864		return err;
 865	}
 866	return 0;
 867}
 868
 869static int sctp_udp_rcv(struct sock *sk, struct sk_buff *skb)
 870{
 871	SCTP_INPUT_CB(skb)->encap_port = udp_hdr(skb)->source;
 872
 873	skb_set_transport_header(skb, sizeof(struct udphdr));
 874	sctp_rcv(skb);
 875	return 0;
 876}
 877
 878int sctp_udp_sock_start(struct net *net)
 879{
 880	struct udp_tunnel_sock_cfg tuncfg = {NULL};
 881	struct udp_port_cfg udp_conf = {0};
 882	struct socket *sock;
 883	int err;
 884
 885	udp_conf.family = AF_INET;
 886	udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
 887	udp_conf.local_udp_port = htons(net->sctp.udp_port);
 888	err = udp_sock_create(net, &udp_conf, &sock);
 889	if (err) {
 890		pr_err("Failed to create the SCTP UDP tunneling v4 sock\n");
 891		return err;
 892	}
 893
 894	tuncfg.encap_type = 1;
 895	tuncfg.encap_rcv = sctp_udp_rcv;
 896	tuncfg.encap_err_lookup = sctp_udp_v4_err;
 897	setup_udp_tunnel_sock(net, sock, &tuncfg);
 898	net->sctp.udp4_sock = sock->sk;
 899
 900#if IS_ENABLED(CONFIG_IPV6)
 901	memset(&udp_conf, 0, sizeof(udp_conf));
 902
 903	udp_conf.family = AF_INET6;
 904	udp_conf.local_ip6 = in6addr_any;
 905	udp_conf.local_udp_port = htons(net->sctp.udp_port);
 906	udp_conf.use_udp6_rx_checksums = true;
 907	udp_conf.ipv6_v6only = true;
 908	err = udp_sock_create(net, &udp_conf, &sock);
 909	if (err) {
 910		pr_err("Failed to create the SCTP UDP tunneling v6 sock\n");
 911		udp_tunnel_sock_release(net->sctp.udp4_sock->sk_socket);
 912		net->sctp.udp4_sock = NULL;
 913		return err;
 914	}
 915
 916	tuncfg.encap_type = 1;
 917	tuncfg.encap_rcv = sctp_udp_rcv;
 918	tuncfg.encap_err_lookup = sctp_udp_v6_err;
 919	setup_udp_tunnel_sock(net, sock, &tuncfg);
 920	net->sctp.udp6_sock = sock->sk;
 921#endif
 922
 923	return 0;
 924}
 925
 926void sctp_udp_sock_stop(struct net *net)
 927{
 928	if (net->sctp.udp4_sock) {
 929		udp_tunnel_sock_release(net->sctp.udp4_sock->sk_socket);
 930		net->sctp.udp4_sock = NULL;
 931	}
 932	if (net->sctp.udp6_sock) {
 933		udp_tunnel_sock_release(net->sctp.udp6_sock->sk_socket);
 934		net->sctp.udp6_sock = NULL;
 935	}
 936}
 937
 938/* Register address family specific functions. */
 939int sctp_register_af(struct sctp_af *af)
 940{
 941	switch (af->sa_family) {
 942	case AF_INET:
 943		if (sctp_af_v4_specific)
 944			return 0;
 945		sctp_af_v4_specific = af;
 946		break;
 947	case AF_INET6:
 948		if (sctp_af_v6_specific)
 949			return 0;
 950		sctp_af_v6_specific = af;
 951		break;
 952	default:
 953		return 0;
 954	}
 955
 956	INIT_LIST_HEAD(&af->list);
 957	list_add_tail(&af->list, &sctp_address_families);
 958	return 1;
 959}
 960
 961/* Get the table of functions for manipulating a particular address
 962 * family.
 963 */
 964struct sctp_af *sctp_get_af_specific(sa_family_t family)
 965{
 966	switch (family) {
 967	case AF_INET:
 968		return sctp_af_v4_specific;
 969	case AF_INET6:
 970		return sctp_af_v6_specific;
 971	default:
 972		return NULL;
 973	}
 974}
 975
 976/* Common code to initialize a AF_INET msg_name. */
 977static void sctp_inet_msgname(char *msgname, int *addr_len)
 978{
 979	struct sockaddr_in *sin;
 980
 981	sin = (struct sockaddr_in *)msgname;
 982	*addr_len = sizeof(struct sockaddr_in);
 983	sin->sin_family = AF_INET;
 984	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
 985}
 986
 987/* Copy the primary address of the peer primary address as the msg_name. */
 988static void sctp_inet_event_msgname(struct sctp_ulpevent *event, char *msgname,
 989				    int *addr_len)
 990{
 991	struct sockaddr_in *sin, *sinfrom;
 992
 993	if (msgname) {
 994		struct sctp_association *asoc;
 995
 996		asoc = event->asoc;
 997		sctp_inet_msgname(msgname, addr_len);
 998		sin = (struct sockaddr_in *)msgname;
 999		sinfrom = &asoc->peer.primary_addr.v4;
1000		sin->sin_port = htons(asoc->peer.port);
1001		sin->sin_addr.s_addr = sinfrom->sin_addr.s_addr;
1002	}
1003}
1004
1005/* Initialize and copy out a msgname from an inbound skb. */
1006static void sctp_inet_skb_msgname(struct sk_buff *skb, char *msgname, int *len)
1007{
1008	if (msgname) {
1009		struct sctphdr *sh = sctp_hdr(skb);
1010		struct sockaddr_in *sin = (struct sockaddr_in *)msgname;
1011
1012		sctp_inet_msgname(msgname, len);
1013		sin->sin_port = sh->source;
1014		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
1015	}
1016}
1017
1018/* Do we support this AF? */
1019static int sctp_inet_af_supported(sa_family_t family, struct sctp_sock *sp)
1020{
1021	/* PF_INET only supports AF_INET addresses. */
1022	return AF_INET == family;
1023}
1024
1025/* Address matching with wildcards allowed. */
1026static int sctp_inet_cmp_addr(const union sctp_addr *addr1,
1027			      const union sctp_addr *addr2,
1028			      struct sctp_sock *opt)
1029{
1030	/* PF_INET only supports AF_INET addresses. */
1031	if (addr1->sa.sa_family != addr2->sa.sa_family)
1032		return 0;
1033	if (htonl(INADDR_ANY) == addr1->v4.sin_addr.s_addr ||
1034	    htonl(INADDR_ANY) == addr2->v4.sin_addr.s_addr)
1035		return 1;
1036	if (addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr)
1037		return 1;
1038
1039	return 0;
1040}
1041
1042/* Verify that provided sockaddr looks bindable.  Common verification has
1043 * already been taken care of.
1044 */
1045static int sctp_inet_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
1046{
1047	return sctp_v4_available(addr, opt);
1048}
1049
1050/* Verify that sockaddr looks sendable.  Common verification has already
1051 * been taken care of.
1052 */
1053static int sctp_inet_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
1054{
1055	return 1;
1056}
1057
1058/* Fill in Supported Address Type information for INIT and INIT-ACK
1059 * chunks.  Returns number of addresses supported.
1060 */
1061static int sctp_inet_supported_addrs(const struct sctp_sock *opt,
1062				     __be16 *types)
1063{
1064	types[0] = SCTP_PARAM_IPV4_ADDRESS;
1065	return 1;
1066}
1067
1068/* Wrapper routine that calls the ip transmit routine. */
1069static inline int sctp_v4_xmit(struct sk_buff *skb, struct sctp_transport *t)
 
1070{
1071	struct dst_entry *dst = dst_clone(t->dst);
1072	struct flowi4 *fl4 = &t->fl.u.ip4;
1073	struct sock *sk = skb->sk;
1074	struct inet_sock *inet = inet_sk(sk);
1075	__u8 dscp = READ_ONCE(inet->tos);
1076	__be16 df = 0;
1077
1078	pr_debug("%s: skb:%p, len:%d, src:%pI4, dst:%pI4\n", __func__, skb,
1079		 skb->len, &fl4->saddr, &fl4->daddr);
 
1080
1081	if (t->dscp & SCTP_DSCP_SET_MASK)
1082		dscp = t->dscp & SCTP_DSCP_VAL_MASK;
1083
1084	inet->pmtudisc = t->param_flags & SPP_PMTUD_ENABLE ? IP_PMTUDISC_DO
1085							   : IP_PMTUDISC_DONT;
1086	SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS);
1087
1088	if (!t->encap_port || !sctp_sk(sk)->udp_port) {
1089		skb_dst_set(skb, dst);
1090		return __ip_queue_xmit(sk, skb, &t->fl, dscp);
1091	}
1092
1093	if (skb_is_gso(skb))
1094		skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL_CSUM;
1095
1096	if (ip_dont_fragment(sk, dst) && !skb->ignore_df)
1097		df = htons(IP_DF);
1098
1099	skb->encapsulation = 1;
1100	skb_reset_inner_mac_header(skb);
1101	skb_reset_inner_transport_header(skb);
1102	skb_set_inner_ipproto(skb, IPPROTO_SCTP);
1103	udp_tunnel_xmit_skb(dst_rtable(dst), sk, skb, fl4->saddr,
1104			    fl4->daddr, dscp, ip4_dst_hoplimit(dst), df,
1105			    sctp_sk(sk)->udp_port, t->encap_port, false, false);
1106	return 0;
1107}
1108
1109static struct sctp_af sctp_af_inet;
1110
1111static struct sctp_pf sctp_pf_inet = {
1112	.event_msgname = sctp_inet_event_msgname,
1113	.skb_msgname   = sctp_inet_skb_msgname,
1114	.af_supported  = sctp_inet_af_supported,
1115	.cmp_addr      = sctp_inet_cmp_addr,
1116	.bind_verify   = sctp_inet_bind_verify,
1117	.send_verify   = sctp_inet_send_verify,
1118	.supported_addrs = sctp_inet_supported_addrs,
1119	.create_accept_sk = sctp_v4_create_accept_sk,
1120	.addr_to_user  = sctp_v4_addr_to_user,
1121	.to_sk_saddr   = sctp_v4_to_sk_saddr,
1122	.to_sk_daddr   = sctp_v4_to_sk_daddr,
1123	.copy_ip_options = sctp_v4_copy_ip_options,
1124	.af            = &sctp_af_inet
1125};
1126
1127/* Notifier for inetaddr addition/deletion events.  */
1128static struct notifier_block sctp_inetaddr_notifier = {
1129	.notifier_call = sctp_inetaddr_event,
1130};
1131
1132/* Socket operations.  */
1133static const struct proto_ops inet_seqpacket_ops = {
1134	.family		   = PF_INET,
1135	.owner		   = THIS_MODULE,
1136	.release	   = inet_release,	/* Needs to be wrapped... */
1137	.bind		   = inet_bind,
1138	.connect	   = sctp_inet_connect,
1139	.socketpair	   = sock_no_socketpair,
1140	.accept		   = inet_accept,
1141	.getname	   = inet_getname,	/* Semantics are different.  */
1142	.poll		   = sctp_poll,
1143	.ioctl		   = inet_ioctl,
1144	.gettstamp	   = sock_gettstamp,
1145	.listen		   = sctp_inet_listen,
1146	.shutdown	   = inet_shutdown,	/* Looks harmless.  */
1147	.setsockopt	   = sock_common_setsockopt, /* IP_SOL IP_OPTION is a problem */
1148	.getsockopt	   = sock_common_getsockopt,
1149	.sendmsg	   = inet_sendmsg,
1150	.recvmsg	   = inet_recvmsg,
1151	.mmap		   = sock_no_mmap,
 
1152};
1153
1154/* Registration with AF_INET family.  */
1155static struct inet_protosw sctp_seqpacket_protosw = {
1156	.type       = SOCK_SEQPACKET,
1157	.protocol   = IPPROTO_SCTP,
1158	.prot       = &sctp_prot,
1159	.ops        = &inet_seqpacket_ops,
1160	.flags      = SCTP_PROTOSW_FLAG
1161};
1162static struct inet_protosw sctp_stream_protosw = {
1163	.type       = SOCK_STREAM,
1164	.protocol   = IPPROTO_SCTP,
1165	.prot       = &sctp_prot,
1166	.ops        = &inet_seqpacket_ops,
1167	.flags      = SCTP_PROTOSW_FLAG
1168};
1169
1170static int sctp4_rcv(struct sk_buff *skb)
1171{
1172	SCTP_INPUT_CB(skb)->encap_port = 0;
1173	return sctp_rcv(skb);
1174}
1175
1176/* Register with IP layer.  */
1177static const struct net_protocol sctp_protocol = {
1178	.handler     = sctp4_rcv,
1179	.err_handler = sctp_v4_err,
1180	.no_policy   = 1,
 
1181	.icmp_strict_tag_validation = 1,
1182};
1183
1184/* IPv4 address related functions.  */
1185static struct sctp_af sctp_af_inet = {
1186	.sa_family	   = AF_INET,
1187	.sctp_xmit	   = sctp_v4_xmit,
1188	.setsockopt	   = ip_setsockopt,
1189	.getsockopt	   = ip_getsockopt,
1190	.get_dst	   = sctp_v4_get_dst,
1191	.get_saddr	   = sctp_v4_get_saddr,
1192	.copy_addrlist	   = sctp_v4_copy_addrlist,
1193	.from_skb	   = sctp_v4_from_skb,
1194	.from_sk	   = sctp_v4_from_sk,
1195	.from_addr_param   = sctp_v4_from_addr_param,
1196	.to_addr_param	   = sctp_v4_to_addr_param,
1197	.cmp_addr	   = sctp_v4_cmp_addr,
1198	.addr_valid	   = sctp_v4_addr_valid,
1199	.inaddr_any	   = sctp_v4_inaddr_any,
1200	.is_any		   = sctp_v4_is_any,
1201	.available	   = sctp_v4_available,
1202	.scope		   = sctp_v4_scope,
1203	.skb_iif	   = sctp_v4_skb_iif,
1204	.skb_sdif	   = sctp_v4_skb_sdif,
1205	.is_ce		   = sctp_v4_is_ce,
1206	.seq_dump_addr	   = sctp_v4_seq_dump_addr,
1207	.ecn_capable	   = sctp_v4_ecn_capable,
1208	.net_header_len	   = sizeof(struct iphdr),
1209	.sockaddr_len	   = sizeof(struct sockaddr_in),
1210	.ip_options_len	   = sctp_v4_ip_options_len,
1211};
1212
1213struct sctp_pf *sctp_get_pf_specific(sa_family_t family)
1214{
1215	switch (family) {
1216	case PF_INET:
1217		return sctp_pf_inet_specific;
1218	case PF_INET6:
1219		return sctp_pf_inet6_specific;
1220	default:
1221		return NULL;
1222	}
1223}
1224
1225/* Register the PF specific function table.  */
1226int sctp_register_pf(struct sctp_pf *pf, sa_family_t family)
1227{
1228	switch (family) {
1229	case PF_INET:
1230		if (sctp_pf_inet_specific)
1231			return 0;
1232		sctp_pf_inet_specific = pf;
1233		break;
1234	case PF_INET6:
1235		if (sctp_pf_inet6_specific)
1236			return 0;
1237		sctp_pf_inet6_specific = pf;
1238		break;
1239	default:
1240		return 0;
1241	}
1242	return 1;
1243}
1244
1245static inline int init_sctp_mibs(struct net *net)
1246{
1247	net->sctp.sctp_statistics = alloc_percpu(struct sctp_mib);
1248	if (!net->sctp.sctp_statistics)
1249		return -ENOMEM;
1250	return 0;
1251}
1252
1253static inline void cleanup_sctp_mibs(struct net *net)
1254{
1255	free_percpu(net->sctp.sctp_statistics);
1256}
1257
1258static void sctp_v4_pf_init(void)
1259{
1260	/* Initialize the SCTP specific PF functions. */
1261	sctp_register_pf(&sctp_pf_inet, PF_INET);
1262	sctp_register_af(&sctp_af_inet);
1263}
1264
1265static void sctp_v4_pf_exit(void)
1266{
1267	list_del(&sctp_af_inet.list);
1268}
1269
1270static int sctp_v4_protosw_init(void)
1271{
1272	int rc;
1273
1274	rc = proto_register(&sctp_prot, 1);
1275	if (rc)
1276		return rc;
1277
1278	/* Register SCTP(UDP and TCP style) with socket layer.  */
1279	inet_register_protosw(&sctp_seqpacket_protosw);
1280	inet_register_protosw(&sctp_stream_protosw);
1281
1282	return 0;
1283}
1284
1285static void sctp_v4_protosw_exit(void)
1286{
1287	inet_unregister_protosw(&sctp_stream_protosw);
1288	inet_unregister_protosw(&sctp_seqpacket_protosw);
1289	proto_unregister(&sctp_prot);
1290}
1291
1292static int sctp_v4_add_protocol(void)
1293{
1294	/* Register notifier for inet address additions/deletions. */
1295	register_inetaddr_notifier(&sctp_inetaddr_notifier);
1296
1297	/* Register SCTP with inet layer.  */
1298	if (inet_add_protocol(&sctp_protocol, IPPROTO_SCTP) < 0)
1299		return -EAGAIN;
1300
1301	return 0;
1302}
1303
1304static void sctp_v4_del_protocol(void)
1305{
1306	inet_del_protocol(&sctp_protocol, IPPROTO_SCTP);
1307	unregister_inetaddr_notifier(&sctp_inetaddr_notifier);
1308}
1309
1310static int __net_init sctp_defaults_init(struct net *net)
1311{
1312	int status;
1313
1314	/*
1315	 * 14. Suggested SCTP Protocol Parameter Values
1316	 */
1317	/* The following protocol parameters are RECOMMENDED:  */
1318	/* RTO.Initial              - 3  seconds */
1319	net->sctp.rto_initial			= SCTP_RTO_INITIAL;
1320	/* RTO.Min                  - 1  second */
1321	net->sctp.rto_min	 		= SCTP_RTO_MIN;
1322	/* RTO.Max                 -  60 seconds */
1323	net->sctp.rto_max 			= SCTP_RTO_MAX;
1324	/* RTO.Alpha                - 1/8 */
1325	net->sctp.rto_alpha			= SCTP_RTO_ALPHA;
1326	/* RTO.Beta                 - 1/4 */
1327	net->sctp.rto_beta			= SCTP_RTO_BETA;
1328
1329	/* Valid.Cookie.Life        - 60  seconds */
1330	net->sctp.valid_cookie_life		= SCTP_DEFAULT_COOKIE_LIFE;
1331
1332	/* Whether Cookie Preservative is enabled(1) or not(0) */
1333	net->sctp.cookie_preserve_enable 	= 1;
1334
1335	/* Default sctp sockets to use md5 as their hmac alg */
1336#if defined (CONFIG_SCTP_DEFAULT_COOKIE_HMAC_MD5)
1337	net->sctp.sctp_hmac_alg			= "md5";
1338#elif defined (CONFIG_SCTP_DEFAULT_COOKIE_HMAC_SHA1)
1339	net->sctp.sctp_hmac_alg			= "sha1";
1340#else
1341	net->sctp.sctp_hmac_alg			= NULL;
1342#endif
1343
1344	/* Max.Burst		    - 4 */
1345	net->sctp.max_burst			= SCTP_DEFAULT_MAX_BURST;
1346
1347	/* Disable of Primary Path Switchover by default */
1348	net->sctp.ps_retrans = SCTP_PS_RETRANS_MAX;
1349
1350	/* Enable pf state by default */
1351	net->sctp.pf_enable = 1;
1352
1353	/* Ignore pf exposure feature by default */
1354	net->sctp.pf_expose = SCTP_PF_EXPOSE_UNSET;
1355
1356	/* Association.Max.Retrans  - 10 attempts
1357	 * Path.Max.Retrans         - 5  attempts (per destination address)
1358	 * Max.Init.Retransmits     - 8  attempts
1359	 */
1360	net->sctp.max_retrans_association	= 10;
1361	net->sctp.max_retrans_path		= 5;
1362	net->sctp.max_retrans_init		= 8;
1363
1364	/* Sendbuffer growth	    - do per-socket accounting */
1365	net->sctp.sndbuf_policy			= 0;
1366
1367	/* Rcvbuffer growth	    - do per-socket accounting */
1368	net->sctp.rcvbuf_policy			= 0;
1369
1370	/* HB.interval              - 30 seconds */
1371	net->sctp.hb_interval			= SCTP_DEFAULT_TIMEOUT_HEARTBEAT;
1372
1373	/* delayed SACK timeout */
1374	net->sctp.sack_timeout			= SCTP_DEFAULT_TIMEOUT_SACK;
1375
1376	/* Disable ADDIP by default. */
1377	net->sctp.addip_enable = 0;
1378	net->sctp.addip_noauth = 0;
1379	net->sctp.default_auto_asconf = 0;
1380
1381	/* Enable PR-SCTP by default. */
1382	net->sctp.prsctp_enable = 1;
1383
1384	/* Disable RECONF by default. */
1385	net->sctp.reconf_enable = 0;
1386
1387	/* Disable AUTH by default. */
1388	net->sctp.auth_enable = 0;
1389
1390	/* Enable ECN by default. */
1391	net->sctp.ecn_enable = 1;
1392
1393	/* Set UDP tunneling listening port to 0 by default */
1394	net->sctp.udp_port = 0;
1395
1396	/* Set remote encap port to 0 by default */
1397	net->sctp.encap_port = 0;
1398
1399	/* Set SCOPE policy to enabled */
1400	net->sctp.scope_policy = SCTP_SCOPE_POLICY_ENABLE;
1401
1402	/* Set the default rwnd update threshold */
1403	net->sctp.rwnd_upd_shift = SCTP_DEFAULT_RWND_SHIFT;
1404
1405	/* Initialize maximum autoclose timeout. */
1406	net->sctp.max_autoclose		= INT_MAX / HZ;
1407
1408#ifdef CONFIG_NET_L3_MASTER_DEV
1409	net->sctp.l3mdev_accept = 1;
1410#endif
1411
1412	status = sctp_sysctl_net_register(net);
1413	if (status)
1414		goto err_sysctl_register;
1415
1416	/* Allocate and initialise sctp mibs.  */
1417	status = init_sctp_mibs(net);
1418	if (status)
1419		goto err_init_mibs;
1420
1421#ifdef CONFIG_PROC_FS
1422	/* Initialize proc fs directory.  */
1423	status = sctp_proc_init(net);
1424	if (status)
1425		goto err_init_proc;
1426#endif
1427
1428	sctp_dbg_objcnt_init(net);
1429
1430	/* Initialize the local address list. */
1431	INIT_LIST_HEAD(&net->sctp.local_addr_list);
1432	spin_lock_init(&net->sctp.local_addr_lock);
1433	sctp_get_local_addr_list(net);
1434
1435	/* Initialize the address event list */
1436	INIT_LIST_HEAD(&net->sctp.addr_waitq);
1437	INIT_LIST_HEAD(&net->sctp.auto_asconf_splist);
1438	spin_lock_init(&net->sctp.addr_wq_lock);
1439	net->sctp.addr_wq_timer.expires = 0;
1440	timer_setup(&net->sctp.addr_wq_timer, sctp_addr_wq_timeout_handler, 0);
1441
1442	return 0;
1443
1444#ifdef CONFIG_PROC_FS
1445err_init_proc:
1446	cleanup_sctp_mibs(net);
1447#endif
1448err_init_mibs:
1449	sctp_sysctl_net_unregister(net);
1450err_sysctl_register:
1451	return status;
1452}
1453
1454static void __net_exit sctp_defaults_exit(struct net *net)
1455{
1456	/* Free the local address list */
1457	sctp_free_addr_wq(net);
1458	sctp_free_local_addr_list(net);
1459
1460#ifdef CONFIG_PROC_FS
1461	remove_proc_subtree("sctp", net->proc_net);
1462	net->sctp.proc_net_sctp = NULL;
1463#endif
1464	cleanup_sctp_mibs(net);
1465	sctp_sysctl_net_unregister(net);
1466}
1467
1468static struct pernet_operations sctp_defaults_ops = {
1469	.init = sctp_defaults_init,
1470	.exit = sctp_defaults_exit,
1471};
1472
1473static int __net_init sctp_ctrlsock_init(struct net *net)
1474{
1475	int status;
1476
1477	/* Initialize the control inode/socket for handling OOTB packets.  */
1478	status = sctp_ctl_sock_init(net);
1479	if (status)
1480		pr_err("Failed to initialize the SCTP control sock\n");
1481
1482	return status;
1483}
1484
1485static void __net_exit sctp_ctrlsock_exit(struct net *net)
1486{
1487	/* Free the control endpoint.  */
1488	inet_ctl_sock_destroy(net->sctp.ctl_sock);
1489}
1490
1491static struct pernet_operations sctp_ctrlsock_ops = {
1492	.init = sctp_ctrlsock_init,
1493	.exit = sctp_ctrlsock_exit,
1494};
1495
1496/* Initialize the universe into something sensible.  */
1497static __init int sctp_init(void)
1498{
1499	unsigned long nr_pages = totalram_pages();
1500	unsigned long limit;
1501	unsigned long goal;
1502	int max_entry_order;
1503	int num_entries;
1504	int max_share;
1505	int status;
1506	int order;
1507	int i;
1508
1509	sock_skb_cb_check_size(sizeof(struct sctp_ulpevent));
1510
1511	/* Allocate bind_bucket and chunk caches. */
1512	status = -ENOBUFS;
1513	sctp_bucket_cachep = KMEM_CACHE(sctp_bind_bucket, SLAB_HWCACHE_ALIGN);
 
 
 
1514	if (!sctp_bucket_cachep)
1515		goto out;
1516
1517	sctp_chunk_cachep = KMEM_CACHE(sctp_chunk, SLAB_HWCACHE_ALIGN);
 
 
 
1518	if (!sctp_chunk_cachep)
1519		goto err_chunk_cachep;
1520
1521	status = percpu_counter_init(&sctp_sockets_allocated, 0, GFP_KERNEL);
1522	if (status)
1523		goto err_percpu_counter_init;
1524
1525	/* Implementation specific variables. */
1526
1527	/* Initialize default stream count setup information. */
1528	sctp_max_instreams    		= SCTP_DEFAULT_INSTREAMS;
1529	sctp_max_outstreams   		= SCTP_DEFAULT_OUTSTREAMS;
1530
1531	/* Initialize handle used for association ids. */
1532	idr_init(&sctp_assocs_id);
1533
1534	limit = nr_free_buffer_pages() / 8;
1535	limit = max(limit, 128UL);
1536	sysctl_sctp_mem[0] = limit / 4 * 3;
1537	sysctl_sctp_mem[1] = limit;
1538	sysctl_sctp_mem[2] = sysctl_sctp_mem[0] * 2;
1539
1540	/* Set per-socket limits to no more than 1/128 the pressure threshold*/
1541	limit = (sysctl_sctp_mem[1]) << (PAGE_SHIFT - 7);
1542	max_share = min(4UL*1024*1024, limit);
1543
1544	sysctl_sctp_rmem[0] = PAGE_SIZE; /* give each asoc 1 page min */
1545	sysctl_sctp_rmem[1] = 1500 * SKB_TRUESIZE(1);
1546	sysctl_sctp_rmem[2] = max(sysctl_sctp_rmem[1], max_share);
1547
1548	sysctl_sctp_wmem[0] = PAGE_SIZE;
1549	sysctl_sctp_wmem[1] = 16*1024;
1550	sysctl_sctp_wmem[2] = max(64*1024, max_share);
1551
1552	/* Size and allocate the association hash table.
1553	 * The methodology is similar to that of the tcp hash tables.
1554	 * Though not identical.  Start by getting a goal size
1555	 */
1556	if (nr_pages >= (128 * 1024))
1557		goal = nr_pages >> (22 - PAGE_SHIFT);
1558	else
1559		goal = nr_pages >> (24 - PAGE_SHIFT);
1560
1561	/* Then compute the page order for said goal */
1562	order = get_order(goal);
1563
1564	/* Now compute the required page order for the maximum sized table we
1565	 * want to create
1566	 */
1567	max_entry_order = get_order(MAX_SCTP_PORT_HASH_ENTRIES *
1568				    sizeof(struct sctp_bind_hashbucket));
1569
1570	/* Limit the page order by that maximum hash table size */
1571	order = min(order, max_entry_order);
1572
1573	/* Allocate and initialize the endpoint hash table.  */
1574	sctp_ep_hashsize = 64;
1575	sctp_ep_hashtable =
1576		kmalloc_array(64, sizeof(struct sctp_hashbucket), GFP_KERNEL);
1577	if (!sctp_ep_hashtable) {
1578		pr_err("Failed endpoint_hash alloc\n");
1579		status = -ENOMEM;
1580		goto err_ehash_alloc;
1581	}
1582	for (i = 0; i < sctp_ep_hashsize; i++) {
1583		rwlock_init(&sctp_ep_hashtable[i].lock);
1584		INIT_HLIST_HEAD(&sctp_ep_hashtable[i].chain);
1585	}
1586
1587	/* Allocate and initialize the SCTP port hash table.
1588	 * Note that order is initalized to start at the max sized
1589	 * table we want to support.  If we can't get that many pages
1590	 * reduce the order and try again
1591	 */
1592	do {
1593		sctp_port_hashtable = (struct sctp_bind_hashbucket *)
1594			__get_free_pages(GFP_KERNEL | __GFP_NOWARN, order);
1595	} while (!sctp_port_hashtable && --order > 0);
1596
1597	if (!sctp_port_hashtable) {
1598		pr_err("Failed bind hash alloc\n");
1599		status = -ENOMEM;
1600		goto err_bhash_alloc;
1601	}
1602
1603	/* Now compute the number of entries that will fit in the
1604	 * port hash space we allocated
1605	 */
1606	num_entries = (1UL << order) * PAGE_SIZE /
1607		      sizeof(struct sctp_bind_hashbucket);
1608
1609	/* And finish by rounding it down to the nearest power of two.
1610	 * This wastes some memory of course, but it's needed because
1611	 * the hash function operates based on the assumption that
1612	 * the number of entries is a power of two.
1613	 */
1614	sctp_port_hashsize = rounddown_pow_of_two(num_entries);
1615
1616	for (i = 0; i < sctp_port_hashsize; i++) {
1617		spin_lock_init(&sctp_port_hashtable[i].lock);
1618		INIT_HLIST_HEAD(&sctp_port_hashtable[i].chain);
1619	}
1620
1621	status = sctp_transport_hashtable_init();
1622	if (status)
1623		goto err_thash_alloc;
1624
1625	pr_info("Hash tables configured (bind %d/%d)\n", sctp_port_hashsize,
1626		num_entries);
1627
1628	sctp_sysctl_register();
1629
1630	INIT_LIST_HEAD(&sctp_address_families);
1631	sctp_v4_pf_init();
1632	sctp_v6_pf_init();
1633	sctp_sched_ops_init();
1634
1635	status = register_pernet_subsys(&sctp_defaults_ops);
1636	if (status)
1637		goto err_register_defaults;
1638
1639	status = sctp_v4_protosw_init();
1640	if (status)
1641		goto err_protosw_init;
1642
1643	status = sctp_v6_protosw_init();
1644	if (status)
1645		goto err_v6_protosw_init;
1646
1647	status = register_pernet_subsys(&sctp_ctrlsock_ops);
1648	if (status)
1649		goto err_register_ctrlsock;
1650
1651	status = sctp_v4_add_protocol();
1652	if (status)
1653		goto err_add_protocol;
1654
1655	/* Register SCTP with inet6 layer.  */
1656	status = sctp_v6_add_protocol();
1657	if (status)
1658		goto err_v6_add_protocol;
1659
1660	if (sctp_offload_init() < 0)
1661		pr_crit("%s: Cannot add SCTP protocol offload\n", __func__);
1662
1663out:
1664	return status;
1665err_v6_add_protocol:
1666	sctp_v4_del_protocol();
1667err_add_protocol:
1668	unregister_pernet_subsys(&sctp_ctrlsock_ops);
1669err_register_ctrlsock:
1670	sctp_v6_protosw_exit();
1671err_v6_protosw_init:
1672	sctp_v4_protosw_exit();
1673err_protosw_init:
1674	unregister_pernet_subsys(&sctp_defaults_ops);
1675err_register_defaults:
1676	sctp_v4_pf_exit();
1677	sctp_v6_pf_exit();
1678	sctp_sysctl_unregister();
1679	free_pages((unsigned long)sctp_port_hashtable,
1680		   get_order(sctp_port_hashsize *
1681			     sizeof(struct sctp_bind_hashbucket)));
1682err_bhash_alloc:
1683	sctp_transport_hashtable_destroy();
1684err_thash_alloc:
1685	kfree(sctp_ep_hashtable);
1686err_ehash_alloc:
1687	percpu_counter_destroy(&sctp_sockets_allocated);
1688err_percpu_counter_init:
1689	kmem_cache_destroy(sctp_chunk_cachep);
1690err_chunk_cachep:
1691	kmem_cache_destroy(sctp_bucket_cachep);
1692	goto out;
1693}
1694
1695/* Exit handler for the SCTP protocol.  */
1696static __exit void sctp_exit(void)
1697{
1698	/* BUG.  This should probably do something useful like clean
1699	 * up all the remaining associations and all that memory.
1700	 */
1701
1702	/* Unregister with inet6/inet layers. */
1703	sctp_v6_del_protocol();
1704	sctp_v4_del_protocol();
1705
1706	unregister_pernet_subsys(&sctp_ctrlsock_ops);
1707
1708	/* Free protosw registrations */
1709	sctp_v6_protosw_exit();
1710	sctp_v4_protosw_exit();
1711
1712	unregister_pernet_subsys(&sctp_defaults_ops);
1713
1714	/* Unregister with socket layer. */
1715	sctp_v6_pf_exit();
1716	sctp_v4_pf_exit();
1717
1718	sctp_sysctl_unregister();
1719
1720	free_pages((unsigned long)sctp_port_hashtable,
1721		   get_order(sctp_port_hashsize *
1722			     sizeof(struct sctp_bind_hashbucket)));
1723	kfree(sctp_ep_hashtable);
1724	sctp_transport_hashtable_destroy();
1725
1726	percpu_counter_destroy(&sctp_sockets_allocated);
1727
1728	rcu_barrier(); /* Wait for completion of call_rcu()'s */
1729
1730	kmem_cache_destroy(sctp_chunk_cachep);
1731	kmem_cache_destroy(sctp_bucket_cachep);
1732}
1733
1734module_init(sctp_init);
1735module_exit(sctp_exit);
1736
1737/*
1738 * __stringify doesn't likes enums, so use IPPROTO_SCTP value (132) directly.
1739 */
1740MODULE_ALIAS("net-pf-" __stringify(PF_INET) "-proto-132");
1741MODULE_ALIAS("net-pf-" __stringify(PF_INET6) "-proto-132");
1742MODULE_AUTHOR("Linux Kernel SCTP developers <linux-sctp@vger.kernel.org>");
1743MODULE_DESCRIPTION("Support for the SCTP protocol (RFC2960)");
1744module_param_named(no_checksums, sctp_checksum_disable, bool, 0644);
1745MODULE_PARM_DESC(no_checksums, "Disable checksums computing and verification");
1746MODULE_LICENSE("GPL");