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