xref: /linux/net/sctp/protocol.c (revision 56d06fa29edd58c448766014afd833b7ff51247b)
1 /* SCTP kernel implementation
2  * (C) Copyright IBM Corp. 2001, 2004
3  * Copyright (c) 1999-2000 Cisco, Inc.
4  * Copyright (c) 1999-2001 Motorola, Inc.
5  * Copyright (c) 2001 Intel Corp.
6  * Copyright (c) 2001 Nokia, Inc.
7  * Copyright (c) 2001 La Monte H.P. Yarroll
8  *
9  * This file is part of the SCTP kernel implementation
10  *
11  * Initialization/cleanup for SCTP protocol support.
12  *
13  * This SCTP implementation is free software;
14  * you can redistribute it and/or modify it under the terms of
15  * the GNU General Public License as published by
16  * the Free Software Foundation; either version 2, or (at your option)
17  * any later version.
18  *
19  * This SCTP implementation is distributed in the hope that it
20  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
21  *                 ************************
22  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
23  * See the GNU General Public License for more details.
24  *
25  * You should have received a copy of the GNU General Public License
26  * along with GNU CC; see the file COPYING.  If not, see
27  * <http://www.gnu.org/licenses/>.
28  *
29  * Please send any bug reports or fixes you make to the
30  * email address(es):
31  *    lksctp developers <linux-sctp@vger.kernel.org>
32  *
33  * Written or modified by:
34  *    La Monte H.P. Yarroll <piggy@acm.org>
35  *    Karl Knutson <karl@athena.chicago.il.us>
36  *    Jon Grimm <jgrimm@us.ibm.com>
37  *    Sridhar Samudrala <sri@us.ibm.com>
38  *    Daisy Chang <daisyc@us.ibm.com>
39  *    Ardelle Fan <ardelle.fan@intel.com>
40  */
41 
42 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
43 
44 #include <linux/module.h>
45 #include <linux/init.h>
46 #include <linux/netdevice.h>
47 #include <linux/inetdevice.h>
48 #include <linux/seq_file.h>
49 #include <linux/bootmem.h>
50 #include <linux/highmem.h>
51 #include <linux/swap.h>
52 #include <linux/slab.h>
53 #include <net/net_namespace.h>
54 #include <net/protocol.h>
55 #include <net/ip.h>
56 #include <net/ipv6.h>
57 #include <net/route.h>
58 #include <net/sctp/sctp.h>
59 #include <net/addrconf.h>
60 #include <net/inet_common.h>
61 #include <net/inet_ecn.h>
62 
63 #define MAX_SCTP_PORT_HASH_ENTRIES (64 * 1024)
64 
65 /* Global data structures. */
66 struct sctp_globals sctp_globals __read_mostly;
67 
68 struct idr sctp_assocs_id;
69 DEFINE_SPINLOCK(sctp_assocs_id_lock);
70 
71 static struct sctp_pf *sctp_pf_inet6_specific;
72 static struct sctp_pf *sctp_pf_inet_specific;
73 static struct sctp_af *sctp_af_v4_specific;
74 static struct sctp_af *sctp_af_v6_specific;
75 
76 struct kmem_cache *sctp_chunk_cachep __read_mostly;
77 struct kmem_cache *sctp_bucket_cachep __read_mostly;
78 
79 long sysctl_sctp_mem[3];
80 int sysctl_sctp_rmem[3];
81 int sysctl_sctp_wmem[3];
82 
83 /* Set up the proc fs entry for the SCTP protocol. */
84 static int __net_init sctp_proc_init(struct net *net)
85 {
86 #ifdef CONFIG_PROC_FS
87 	net->sctp.proc_net_sctp = proc_net_mkdir(net, "sctp", net->proc_net);
88 	if (!net->sctp.proc_net_sctp)
89 		goto out_proc_net_sctp;
90 	if (sctp_snmp_proc_init(net))
91 		goto out_snmp_proc_init;
92 	if (sctp_eps_proc_init(net))
93 		goto out_eps_proc_init;
94 	if (sctp_assocs_proc_init(net))
95 		goto out_assocs_proc_init;
96 	if (sctp_remaddr_proc_init(net))
97 		goto out_remaddr_proc_init;
98 
99 	return 0;
100 
101 out_remaddr_proc_init:
102 	sctp_assocs_proc_exit(net);
103 out_assocs_proc_init:
104 	sctp_eps_proc_exit(net);
105 out_eps_proc_init:
106 	sctp_snmp_proc_exit(net);
107 out_snmp_proc_init:
108 	remove_proc_entry("sctp", net->proc_net);
109 	net->sctp.proc_net_sctp = NULL;
110 out_proc_net_sctp:
111 	return -ENOMEM;
112 #endif /* CONFIG_PROC_FS */
113 	return 0;
114 }
115 
116 /* Clean up the proc fs entry for the SCTP protocol.
117  * Note: Do not make this __exit as it is used in the init error
118  * path.
119  */
120 static void sctp_proc_exit(struct net *net)
121 {
122 #ifdef CONFIG_PROC_FS
123 	sctp_snmp_proc_exit(net);
124 	sctp_eps_proc_exit(net);
125 	sctp_assocs_proc_exit(net);
126 	sctp_remaddr_proc_exit(net);
127 
128 	remove_proc_entry("sctp", net->proc_net);
129 	net->sctp.proc_net_sctp = NULL;
130 #endif
131 }
132 
133 /* Private helper to extract ipv4 address and stash them in
134  * the protocol structure.
135  */
136 static void sctp_v4_copy_addrlist(struct list_head *addrlist,
137 				  struct net_device *dev)
138 {
139 	struct in_device *in_dev;
140 	struct in_ifaddr *ifa;
141 	struct sctp_sockaddr_entry *addr;
142 
143 	rcu_read_lock();
144 	if ((in_dev = __in_dev_get_rcu(dev)) == NULL) {
145 		rcu_read_unlock();
146 		return;
147 	}
148 
149 	for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) {
150 		/* Add the address to the local list.  */
151 		addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
152 		if (addr) {
153 			addr->a.v4.sin_family = AF_INET;
154 			addr->a.v4.sin_port = 0;
155 			addr->a.v4.sin_addr.s_addr = ifa->ifa_local;
156 			addr->valid = 1;
157 			INIT_LIST_HEAD(&addr->list);
158 			list_add_tail(&addr->list, addrlist);
159 		}
160 	}
161 
162 	rcu_read_unlock();
163 }
164 
165 /* Extract our IP addresses from the system and stash them in the
166  * protocol structure.
167  */
168 static void sctp_get_local_addr_list(struct net *net)
169 {
170 	struct net_device *dev;
171 	struct list_head *pos;
172 	struct sctp_af *af;
173 
174 	rcu_read_lock();
175 	for_each_netdev_rcu(net, dev) {
176 		list_for_each(pos, &sctp_address_families) {
177 			af = list_entry(pos, struct sctp_af, list);
178 			af->copy_addrlist(&net->sctp.local_addr_list, dev);
179 		}
180 	}
181 	rcu_read_unlock();
182 }
183 
184 /* Free the existing local addresses.  */
185 static void sctp_free_local_addr_list(struct net *net)
186 {
187 	struct sctp_sockaddr_entry *addr;
188 	struct list_head *pos, *temp;
189 
190 	list_for_each_safe(pos, temp, &net->sctp.local_addr_list) {
191 		addr = list_entry(pos, struct sctp_sockaddr_entry, list);
192 		list_del(pos);
193 		kfree(addr);
194 	}
195 }
196 
197 /* Copy the local addresses which are valid for 'scope' into 'bp'.  */
198 int sctp_copy_local_addr_list(struct net *net, struct sctp_bind_addr *bp,
199 			      sctp_scope_t scope, gfp_t gfp, int copy_flags)
200 {
201 	struct sctp_sockaddr_entry *addr;
202 	int error = 0;
203 
204 	rcu_read_lock();
205 	list_for_each_entry_rcu(addr, &net->sctp.local_addr_list, list) {
206 		if (!addr->valid)
207 			continue;
208 		if (sctp_in_scope(net, &addr->a, scope)) {
209 			/* Now that the address is in scope, check to see if
210 			 * the address type is really supported by the local
211 			 * sock as well as the remote peer.
212 			 */
213 			if ((((AF_INET == addr->a.sa.sa_family) &&
214 			      (copy_flags & SCTP_ADDR4_PEERSUPP))) ||
215 			    (((AF_INET6 == addr->a.sa.sa_family) &&
216 			      (copy_flags & SCTP_ADDR6_ALLOWED) &&
217 			      (copy_flags & SCTP_ADDR6_PEERSUPP)))) {
218 				error = sctp_add_bind_addr(bp, &addr->a,
219 						    sizeof(addr->a),
220 						    SCTP_ADDR_SRC, GFP_ATOMIC);
221 				if (error)
222 					goto end_copy;
223 			}
224 		}
225 	}
226 
227 end_copy:
228 	rcu_read_unlock();
229 	return error;
230 }
231 
232 /* Initialize a sctp_addr from in incoming skb.  */
233 static void sctp_v4_from_skb(union sctp_addr *addr, struct sk_buff *skb,
234 			     int is_saddr)
235 {
236 	void *from;
237 	__be16 *port;
238 	struct sctphdr *sh;
239 
240 	port = &addr->v4.sin_port;
241 	addr->v4.sin_family = AF_INET;
242 
243 	sh = sctp_hdr(skb);
244 	if (is_saddr) {
245 		*port  = sh->source;
246 		from = &ip_hdr(skb)->saddr;
247 	} else {
248 		*port = sh->dest;
249 		from = &ip_hdr(skb)->daddr;
250 	}
251 	memcpy(&addr->v4.sin_addr.s_addr, from, sizeof(struct in_addr));
252 }
253 
254 /* Initialize an sctp_addr from a socket. */
255 static void sctp_v4_from_sk(union sctp_addr *addr, struct sock *sk)
256 {
257 	addr->v4.sin_family = AF_INET;
258 	addr->v4.sin_port = 0;
259 	addr->v4.sin_addr.s_addr = inet_sk(sk)->inet_rcv_saddr;
260 }
261 
262 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
263 static void sctp_v4_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
264 {
265 	inet_sk(sk)->inet_rcv_saddr = addr->v4.sin_addr.s_addr;
266 }
267 
268 /* Initialize sk->sk_daddr from sctp_addr. */
269 static void sctp_v4_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
270 {
271 	inet_sk(sk)->inet_daddr = addr->v4.sin_addr.s_addr;
272 }
273 
274 /* Initialize a sctp_addr from an address parameter. */
275 static void sctp_v4_from_addr_param(union sctp_addr *addr,
276 				    union sctp_addr_param *param,
277 				    __be16 port, int iif)
278 {
279 	addr->v4.sin_family = AF_INET;
280 	addr->v4.sin_port = port;
281 	addr->v4.sin_addr.s_addr = param->v4.addr.s_addr;
282 }
283 
284 /* Initialize an address parameter from a sctp_addr and return the length
285  * of the address parameter.
286  */
287 static int sctp_v4_to_addr_param(const union sctp_addr *addr,
288 				 union sctp_addr_param *param)
289 {
290 	int length = sizeof(sctp_ipv4addr_param_t);
291 
292 	param->v4.param_hdr.type = SCTP_PARAM_IPV4_ADDRESS;
293 	param->v4.param_hdr.length = htons(length);
294 	param->v4.addr.s_addr = addr->v4.sin_addr.s_addr;
295 
296 	return length;
297 }
298 
299 /* Initialize a sctp_addr from a dst_entry. */
300 static void sctp_v4_dst_saddr(union sctp_addr *saddr, struct flowi4 *fl4,
301 			      __be16 port)
302 {
303 	saddr->v4.sin_family = AF_INET;
304 	saddr->v4.sin_port = port;
305 	saddr->v4.sin_addr.s_addr = fl4->saddr;
306 }
307 
308 /* Compare two addresses exactly. */
309 static int sctp_v4_cmp_addr(const union sctp_addr *addr1,
310 			    const union sctp_addr *addr2)
311 {
312 	if (addr1->sa.sa_family != addr2->sa.sa_family)
313 		return 0;
314 	if (addr1->v4.sin_port != addr2->v4.sin_port)
315 		return 0;
316 	if (addr1->v4.sin_addr.s_addr != addr2->v4.sin_addr.s_addr)
317 		return 0;
318 
319 	return 1;
320 }
321 
322 /* Initialize addr struct to INADDR_ANY. */
323 static void sctp_v4_inaddr_any(union sctp_addr *addr, __be16 port)
324 {
325 	addr->v4.sin_family = AF_INET;
326 	addr->v4.sin_addr.s_addr = htonl(INADDR_ANY);
327 	addr->v4.sin_port = port;
328 }
329 
330 /* Is this a wildcard address? */
331 static int sctp_v4_is_any(const union sctp_addr *addr)
332 {
333 	return htonl(INADDR_ANY) == addr->v4.sin_addr.s_addr;
334 }
335 
336 /* This function checks if the address is a valid address to be used for
337  * SCTP binding.
338  *
339  * Output:
340  * Return 0 - If the address is a non-unicast or an illegal address.
341  * Return 1 - If the address is a unicast.
342  */
343 static int sctp_v4_addr_valid(union sctp_addr *addr,
344 			      struct sctp_sock *sp,
345 			      const struct sk_buff *skb)
346 {
347 	/* IPv4 addresses not allowed */
348 	if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
349 		return 0;
350 
351 	/* Is this a non-unicast address or a unusable SCTP address? */
352 	if (IS_IPV4_UNUSABLE_ADDRESS(addr->v4.sin_addr.s_addr))
353 		return 0;
354 
355 	/* Is this a broadcast address? */
356 	if (skb && skb_rtable(skb)->rt_flags & RTCF_BROADCAST)
357 		return 0;
358 
359 	return 1;
360 }
361 
362 /* Should this be available for binding?   */
363 static int sctp_v4_available(union sctp_addr *addr, struct sctp_sock *sp)
364 {
365 	struct net *net = sock_net(&sp->inet.sk);
366 	int ret = inet_addr_type(net, addr->v4.sin_addr.s_addr);
367 
368 
369 	if (addr->v4.sin_addr.s_addr != htonl(INADDR_ANY) &&
370 	   ret != RTN_LOCAL &&
371 	   !sp->inet.freebind &&
372 	   !net->ipv4.sysctl_ip_nonlocal_bind)
373 		return 0;
374 
375 	if (ipv6_only_sock(sctp_opt2sk(sp)))
376 		return 0;
377 
378 	return 1;
379 }
380 
381 /* Checking the loopback, private and other address scopes as defined in
382  * RFC 1918.   The IPv4 scoping is based on the draft for SCTP IPv4
383  * scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>.
384  *
385  * Level 0 - unusable SCTP addresses
386  * Level 1 - loopback address
387  * Level 2 - link-local addresses
388  * Level 3 - private addresses.
389  * Level 4 - global addresses
390  * For INIT and INIT-ACK address list, let L be the level of
391  * of requested destination address, sender and receiver
392  * SHOULD include all of its addresses with level greater
393  * than or equal to L.
394  *
395  * IPv4 scoping can be controlled through sysctl option
396  * net.sctp.addr_scope_policy
397  */
398 static sctp_scope_t sctp_v4_scope(union sctp_addr *addr)
399 {
400 	sctp_scope_t retval;
401 
402 	/* Check for unusable SCTP addresses. */
403 	if (IS_IPV4_UNUSABLE_ADDRESS(addr->v4.sin_addr.s_addr)) {
404 		retval =  SCTP_SCOPE_UNUSABLE;
405 	} else if (ipv4_is_loopback(addr->v4.sin_addr.s_addr)) {
406 		retval = SCTP_SCOPE_LOOPBACK;
407 	} else if (ipv4_is_linklocal_169(addr->v4.sin_addr.s_addr)) {
408 		retval = SCTP_SCOPE_LINK;
409 	} else if (ipv4_is_private_10(addr->v4.sin_addr.s_addr) ||
410 		   ipv4_is_private_172(addr->v4.sin_addr.s_addr) ||
411 		   ipv4_is_private_192(addr->v4.sin_addr.s_addr)) {
412 		retval = SCTP_SCOPE_PRIVATE;
413 	} else {
414 		retval = SCTP_SCOPE_GLOBAL;
415 	}
416 
417 	return retval;
418 }
419 
420 /* Returns a valid dst cache entry for the given source and destination ip
421  * addresses. If an association is passed, trys to get a dst entry with a
422  * source address that matches an address in the bind address list.
423  */
424 static void sctp_v4_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
425 				struct flowi *fl, struct sock *sk)
426 {
427 	struct sctp_association *asoc = t->asoc;
428 	struct rtable *rt;
429 	struct flowi4 *fl4 = &fl->u.ip4;
430 	struct sctp_bind_addr *bp;
431 	struct sctp_sockaddr_entry *laddr;
432 	struct dst_entry *dst = NULL;
433 	union sctp_addr *daddr = &t->ipaddr;
434 	union sctp_addr dst_saddr;
435 
436 	memset(fl4, 0x0, sizeof(struct flowi4));
437 	fl4->daddr  = daddr->v4.sin_addr.s_addr;
438 	fl4->fl4_dport = daddr->v4.sin_port;
439 	fl4->flowi4_proto = IPPROTO_SCTP;
440 	if (asoc) {
441 		fl4->flowi4_tos = RT_CONN_FLAGS(asoc->base.sk);
442 		fl4->flowi4_oif = asoc->base.sk->sk_bound_dev_if;
443 		fl4->fl4_sport = htons(asoc->base.bind_addr.port);
444 	}
445 	if (saddr) {
446 		fl4->saddr = saddr->v4.sin_addr.s_addr;
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 
457 	/* If there is no association or if a source address is passed, no
458 	 * more validation is required.
459 	 */
460 	if (!asoc || saddr)
461 		goto out;
462 
463 	bp = &asoc->base.bind_addr;
464 
465 	if (dst) {
466 		/* Walk through the bind address list and look for a bind
467 		 * address that matches the source address of the returned dst.
468 		 */
469 		sctp_v4_dst_saddr(&dst_saddr, fl4, htons(bp->port));
470 		rcu_read_lock();
471 		list_for_each_entry_rcu(laddr, &bp->address_list, list) {
472 			if (!laddr->valid || (laddr->state == SCTP_ADDR_DEL) ||
473 			    (laddr->state != SCTP_ADDR_SRC &&
474 			    !asoc->src_out_of_asoc_ok))
475 				continue;
476 			if (sctp_v4_cmp_addr(&dst_saddr, &laddr->a))
477 				goto out_unlock;
478 		}
479 		rcu_read_unlock();
480 
481 		/* None of the bound addresses match the source address of the
482 		 * dst. So release it.
483 		 */
484 		dst_release(dst);
485 		dst = NULL;
486 	}
487 
488 	/* Walk through the bind address list and try to get a dst that
489 	 * matches a bind address as the source address.
490 	 */
491 	rcu_read_lock();
492 	list_for_each_entry_rcu(laddr, &bp->address_list, list) {
493 		struct net_device *odev;
494 
495 		if (!laddr->valid)
496 			continue;
497 		if (laddr->state != SCTP_ADDR_SRC ||
498 		    AF_INET != laddr->a.sa.sa_family)
499 			continue;
500 
501 		fl4->fl4_sport = laddr->a.v4.sin_port;
502 		flowi4_update_output(fl4,
503 				     asoc->base.sk->sk_bound_dev_if,
504 				     RT_CONN_FLAGS(asoc->base.sk),
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 		if (!dst)
513 			dst = &rt->dst;
514 
515 		/* Ensure the src address belongs to the output
516 		 * interface.
517 		 */
518 		odev = __ip_dev_find(sock_net(sk), laddr->a.v4.sin_addr.s_addr,
519 				     false);
520 		if (!odev || odev->ifindex != fl4->flowi4_oif) {
521 			if (&rt->dst != dst)
522 				dst_release(&rt->dst);
523 			continue;
524 		}
525 
526 		if (dst != &rt->dst)
527 			dst_release(dst);
528 		dst = &rt->dst;
529 		break;
530 	}
531 
532 out_unlock:
533 	rcu_read_unlock();
534 out:
535 	t->dst = dst;
536 	if (dst)
537 		pr_debug("rt_dst:%pI4, rt_src:%pI4\n",
538 			 &fl4->daddr, &fl4->saddr);
539 	else
540 		pr_debug("no route\n");
541 }
542 
543 /* For v4, the source address is cached in the route entry(dst). So no need
544  * to cache it separately and hence this is an empty routine.
545  */
546 static void sctp_v4_get_saddr(struct sctp_sock *sk,
547 			      struct sctp_transport *t,
548 			      struct flowi *fl)
549 {
550 	union sctp_addr *saddr = &t->saddr;
551 	struct rtable *rt = (struct rtable *)t->dst;
552 
553 	if (rt) {
554 		saddr->v4.sin_family = AF_INET;
555 		saddr->v4.sin_addr.s_addr = fl->u.ip4.saddr;
556 	}
557 }
558 
559 /* What interface did this skb arrive on? */
560 static int sctp_v4_skb_iif(const struct sk_buff *skb)
561 {
562 	return inet_iif(skb);
563 }
564 
565 /* Was this packet marked by Explicit Congestion Notification? */
566 static int sctp_v4_is_ce(const struct sk_buff *skb)
567 {
568 	return INET_ECN_is_ce(ip_hdr(skb)->tos);
569 }
570 
571 /* Create and initialize a new sk for the socket returned by accept(). */
572 static struct sock *sctp_v4_create_accept_sk(struct sock *sk,
573 					     struct sctp_association *asoc)
574 {
575 	struct sock *newsk = sk_alloc(sock_net(sk), PF_INET, GFP_KERNEL,
576 			sk->sk_prot, 0);
577 	struct inet_sock *newinet;
578 
579 	if (!newsk)
580 		goto out;
581 
582 	sock_init_data(NULL, newsk);
583 
584 	sctp_copy_sock(newsk, sk, asoc);
585 	sock_reset_flag(newsk, SOCK_ZAPPED);
586 
587 	newinet = inet_sk(newsk);
588 
589 	newinet->inet_daddr = asoc->peer.primary_addr.v4.sin_addr.s_addr;
590 
591 	sk_refcnt_debug_inc(newsk);
592 
593 	if (newsk->sk_prot->init(newsk)) {
594 		sk_common_release(newsk);
595 		newsk = NULL;
596 	}
597 
598 out:
599 	return newsk;
600 }
601 
602 static int sctp_v4_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
603 {
604 	/* No address mapping for V4 sockets */
605 	return sizeof(struct sockaddr_in);
606 }
607 
608 /* Dump the v4 addr to the seq file. */
609 static void sctp_v4_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
610 {
611 	seq_printf(seq, "%pI4 ", &addr->v4.sin_addr);
612 }
613 
614 static void sctp_v4_ecn_capable(struct sock *sk)
615 {
616 	INET_ECN_xmit(sk);
617 }
618 
619 static void sctp_addr_wq_timeout_handler(unsigned long arg)
620 {
621 	struct net *net = (struct net *)arg;
622 	struct sctp_sockaddr_entry *addrw, *temp;
623 	struct sctp_sock *sp;
624 
625 	spin_lock_bh(&net->sctp.addr_wq_lock);
626 
627 	list_for_each_entry_safe(addrw, temp, &net->sctp.addr_waitq, list) {
628 		pr_debug("%s: the first ent in wq:%p is addr:%pISc for cmd:%d at "
629 			 "entry:%p\n", __func__, &net->sctp.addr_waitq, &addrw->a.sa,
630 			 addrw->state, addrw);
631 
632 #if IS_ENABLED(CONFIG_IPV6)
633 		/* Now we send an ASCONF for each association */
634 		/* Note. we currently don't handle link local IPv6 addressees */
635 		if (addrw->a.sa.sa_family == AF_INET6) {
636 			struct in6_addr *in6;
637 
638 			if (ipv6_addr_type(&addrw->a.v6.sin6_addr) &
639 			    IPV6_ADDR_LINKLOCAL)
640 				goto free_next;
641 
642 			in6 = (struct in6_addr *)&addrw->a.v6.sin6_addr;
643 			if (ipv6_chk_addr(net, in6, NULL, 0) == 0 &&
644 			    addrw->state == SCTP_ADDR_NEW) {
645 				unsigned long timeo_val;
646 
647 				pr_debug("%s: this is on DAD, trying %d sec "
648 					 "later\n", __func__,
649 					 SCTP_ADDRESS_TICK_DELAY);
650 
651 				timeo_val = jiffies;
652 				timeo_val += msecs_to_jiffies(SCTP_ADDRESS_TICK_DELAY);
653 				mod_timer(&net->sctp.addr_wq_timer, timeo_val);
654 				break;
655 			}
656 		}
657 #endif
658 		list_for_each_entry(sp, &net->sctp.auto_asconf_splist, auto_asconf_list) {
659 			struct sock *sk;
660 
661 			sk = sctp_opt2sk(sp);
662 			/* ignore bound-specific endpoints */
663 			if (!sctp_is_ep_boundall(sk))
664 				continue;
665 			bh_lock_sock(sk);
666 			if (sctp_asconf_mgmt(sp, addrw) < 0)
667 				pr_debug("%s: sctp_asconf_mgmt failed\n", __func__);
668 			bh_unlock_sock(sk);
669 		}
670 #if IS_ENABLED(CONFIG_IPV6)
671 free_next:
672 #endif
673 		list_del(&addrw->list);
674 		kfree(addrw);
675 	}
676 	spin_unlock_bh(&net->sctp.addr_wq_lock);
677 }
678 
679 static void sctp_free_addr_wq(struct net *net)
680 {
681 	struct sctp_sockaddr_entry *addrw;
682 	struct sctp_sockaddr_entry *temp;
683 
684 	spin_lock_bh(&net->sctp.addr_wq_lock);
685 	del_timer(&net->sctp.addr_wq_timer);
686 	list_for_each_entry_safe(addrw, temp, &net->sctp.addr_waitq, list) {
687 		list_del(&addrw->list);
688 		kfree(addrw);
689 	}
690 	spin_unlock_bh(&net->sctp.addr_wq_lock);
691 }
692 
693 /* lookup the entry for the same address in the addr_waitq
694  * sctp_addr_wq MUST be locked
695  */
696 static struct sctp_sockaddr_entry *sctp_addr_wq_lookup(struct net *net,
697 					struct sctp_sockaddr_entry *addr)
698 {
699 	struct sctp_sockaddr_entry *addrw;
700 
701 	list_for_each_entry(addrw, &net->sctp.addr_waitq, list) {
702 		if (addrw->a.sa.sa_family != addr->a.sa.sa_family)
703 			continue;
704 		if (addrw->a.sa.sa_family == AF_INET) {
705 			if (addrw->a.v4.sin_addr.s_addr ==
706 			    addr->a.v4.sin_addr.s_addr)
707 				return addrw;
708 		} else if (addrw->a.sa.sa_family == AF_INET6) {
709 			if (ipv6_addr_equal(&addrw->a.v6.sin6_addr,
710 			    &addr->a.v6.sin6_addr))
711 				return addrw;
712 		}
713 	}
714 	return NULL;
715 }
716 
717 void sctp_addr_wq_mgmt(struct net *net, struct sctp_sockaddr_entry *addr, int cmd)
718 {
719 	struct sctp_sockaddr_entry *addrw;
720 	unsigned long timeo_val;
721 
722 	/* first, we check if an opposite message already exist in the queue.
723 	 * If we found such message, it is removed.
724 	 * This operation is a bit stupid, but the DHCP client attaches the
725 	 * new address after a couple of addition and deletion of that address
726 	 */
727 
728 	spin_lock_bh(&net->sctp.addr_wq_lock);
729 	/* Offsets existing events in addr_wq */
730 	addrw = sctp_addr_wq_lookup(net, addr);
731 	if (addrw) {
732 		if (addrw->state != cmd) {
733 			pr_debug("%s: offsets existing entry for %d, addr:%pISc "
734 				 "in wq:%p\n", __func__, addrw->state, &addrw->a.sa,
735 				 &net->sctp.addr_waitq);
736 
737 			list_del(&addrw->list);
738 			kfree(addrw);
739 		}
740 		spin_unlock_bh(&net->sctp.addr_wq_lock);
741 		return;
742 	}
743 
744 	/* OK, we have to add the new address to the wait queue */
745 	addrw = kmemdup(addr, sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
746 	if (addrw == NULL) {
747 		spin_unlock_bh(&net->sctp.addr_wq_lock);
748 		return;
749 	}
750 	addrw->state = cmd;
751 	list_add_tail(&addrw->list, &net->sctp.addr_waitq);
752 
753 	pr_debug("%s: add new entry for cmd:%d, addr:%pISc in wq:%p\n",
754 		 __func__, addrw->state, &addrw->a.sa, &net->sctp.addr_waitq);
755 
756 	if (!timer_pending(&net->sctp.addr_wq_timer)) {
757 		timeo_val = jiffies;
758 		timeo_val += msecs_to_jiffies(SCTP_ADDRESS_TICK_DELAY);
759 		mod_timer(&net->sctp.addr_wq_timer, timeo_val);
760 	}
761 	spin_unlock_bh(&net->sctp.addr_wq_lock);
762 }
763 
764 /* Event handler for inet address addition/deletion events.
765  * The sctp_local_addr_list needs to be protocted by a spin lock since
766  * multiple notifiers (say IPv4 and IPv6) may be running at the same
767  * time and thus corrupt the list.
768  * The reader side is protected with RCU.
769  */
770 static int sctp_inetaddr_event(struct notifier_block *this, unsigned long ev,
771 			       void *ptr)
772 {
773 	struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
774 	struct sctp_sockaddr_entry *addr = NULL;
775 	struct sctp_sockaddr_entry *temp;
776 	struct net *net = dev_net(ifa->ifa_dev->dev);
777 	int found = 0;
778 
779 	switch (ev) {
780 	case NETDEV_UP:
781 		addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
782 		if (addr) {
783 			addr->a.v4.sin_family = AF_INET;
784 			addr->a.v4.sin_port = 0;
785 			addr->a.v4.sin_addr.s_addr = ifa->ifa_local;
786 			addr->valid = 1;
787 			spin_lock_bh(&net->sctp.local_addr_lock);
788 			list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
789 			sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
790 			spin_unlock_bh(&net->sctp.local_addr_lock);
791 		}
792 		break;
793 	case NETDEV_DOWN:
794 		spin_lock_bh(&net->sctp.local_addr_lock);
795 		list_for_each_entry_safe(addr, temp,
796 					&net->sctp.local_addr_list, list) {
797 			if (addr->a.sa.sa_family == AF_INET &&
798 					addr->a.v4.sin_addr.s_addr ==
799 					ifa->ifa_local) {
800 				sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
801 				found = 1;
802 				addr->valid = 0;
803 				list_del_rcu(&addr->list);
804 				break;
805 			}
806 		}
807 		spin_unlock_bh(&net->sctp.local_addr_lock);
808 		if (found)
809 			kfree_rcu(addr, rcu);
810 		break;
811 	}
812 
813 	return NOTIFY_DONE;
814 }
815 
816 /*
817  * Initialize the control inode/socket with a control endpoint data
818  * structure.  This endpoint is reserved exclusively for the OOTB processing.
819  */
820 static int sctp_ctl_sock_init(struct net *net)
821 {
822 	int err;
823 	sa_family_t family = PF_INET;
824 
825 	if (sctp_get_pf_specific(PF_INET6))
826 		family = PF_INET6;
827 
828 	err = inet_ctl_sock_create(&net->sctp.ctl_sock, family,
829 				   SOCK_SEQPACKET, IPPROTO_SCTP, net);
830 
831 	/* If IPv6 socket could not be created, try the IPv4 socket */
832 	if (err < 0 && family == PF_INET6)
833 		err = inet_ctl_sock_create(&net->sctp.ctl_sock, AF_INET,
834 					   SOCK_SEQPACKET, IPPROTO_SCTP,
835 					   net);
836 
837 	if (err < 0) {
838 		pr_err("Failed to create the SCTP control socket\n");
839 		return err;
840 	}
841 	return 0;
842 }
843 
844 /* Register address family specific functions. */
845 int sctp_register_af(struct sctp_af *af)
846 {
847 	switch (af->sa_family) {
848 	case AF_INET:
849 		if (sctp_af_v4_specific)
850 			return 0;
851 		sctp_af_v4_specific = af;
852 		break;
853 	case AF_INET6:
854 		if (sctp_af_v6_specific)
855 			return 0;
856 		sctp_af_v6_specific = af;
857 		break;
858 	default:
859 		return 0;
860 	}
861 
862 	INIT_LIST_HEAD(&af->list);
863 	list_add_tail(&af->list, &sctp_address_families);
864 	return 1;
865 }
866 
867 /* Get the table of functions for manipulating a particular address
868  * family.
869  */
870 struct sctp_af *sctp_get_af_specific(sa_family_t family)
871 {
872 	switch (family) {
873 	case AF_INET:
874 		return sctp_af_v4_specific;
875 	case AF_INET6:
876 		return sctp_af_v6_specific;
877 	default:
878 		return NULL;
879 	}
880 }
881 
882 /* Common code to initialize a AF_INET msg_name. */
883 static void sctp_inet_msgname(char *msgname, int *addr_len)
884 {
885 	struct sockaddr_in *sin;
886 
887 	sin = (struct sockaddr_in *)msgname;
888 	*addr_len = sizeof(struct sockaddr_in);
889 	sin->sin_family = AF_INET;
890 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
891 }
892 
893 /* Copy the primary address of the peer primary address as the msg_name. */
894 static void sctp_inet_event_msgname(struct sctp_ulpevent *event, char *msgname,
895 				    int *addr_len)
896 {
897 	struct sockaddr_in *sin, *sinfrom;
898 
899 	if (msgname) {
900 		struct sctp_association *asoc;
901 
902 		asoc = event->asoc;
903 		sctp_inet_msgname(msgname, addr_len);
904 		sin = (struct sockaddr_in *)msgname;
905 		sinfrom = &asoc->peer.primary_addr.v4;
906 		sin->sin_port = htons(asoc->peer.port);
907 		sin->sin_addr.s_addr = sinfrom->sin_addr.s_addr;
908 	}
909 }
910 
911 /* Initialize and copy out a msgname from an inbound skb. */
912 static void sctp_inet_skb_msgname(struct sk_buff *skb, char *msgname, int *len)
913 {
914 	if (msgname) {
915 		struct sctphdr *sh = sctp_hdr(skb);
916 		struct sockaddr_in *sin = (struct sockaddr_in *)msgname;
917 
918 		sctp_inet_msgname(msgname, len);
919 		sin->sin_port = sh->source;
920 		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
921 	}
922 }
923 
924 /* Do we support this AF? */
925 static int sctp_inet_af_supported(sa_family_t family, struct sctp_sock *sp)
926 {
927 	/* PF_INET only supports AF_INET addresses. */
928 	return AF_INET == family;
929 }
930 
931 /* Address matching with wildcards allowed. */
932 static int sctp_inet_cmp_addr(const union sctp_addr *addr1,
933 			      const union sctp_addr *addr2,
934 			      struct sctp_sock *opt)
935 {
936 	/* PF_INET only supports AF_INET addresses. */
937 	if (addr1->sa.sa_family != addr2->sa.sa_family)
938 		return 0;
939 	if (htonl(INADDR_ANY) == addr1->v4.sin_addr.s_addr ||
940 	    htonl(INADDR_ANY) == addr2->v4.sin_addr.s_addr)
941 		return 1;
942 	if (addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr)
943 		return 1;
944 
945 	return 0;
946 }
947 
948 /* Verify that provided sockaddr looks bindable.  Common verification has
949  * already been taken care of.
950  */
951 static int sctp_inet_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
952 {
953 	return sctp_v4_available(addr, opt);
954 }
955 
956 /* Verify that sockaddr looks sendable.  Common verification has already
957  * been taken care of.
958  */
959 static int sctp_inet_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
960 {
961 	return 1;
962 }
963 
964 /* Fill in Supported Address Type information for INIT and INIT-ACK
965  * chunks.  Returns number of addresses supported.
966  */
967 static int sctp_inet_supported_addrs(const struct sctp_sock *opt,
968 				     __be16 *types)
969 {
970 	types[0] = SCTP_PARAM_IPV4_ADDRESS;
971 	return 1;
972 }
973 
974 /* Wrapper routine that calls the ip transmit routine. */
975 static inline int sctp_v4_xmit(struct sk_buff *skb,
976 			       struct sctp_transport *transport)
977 {
978 	struct inet_sock *inet = inet_sk(skb->sk);
979 
980 	pr_debug("%s: skb:%p, len:%d, src:%pI4, dst:%pI4\n", __func__, skb,
981 		 skb->len, &transport->fl.u.ip4.saddr, &transport->fl.u.ip4.daddr);
982 
983 	inet->pmtudisc = transport->param_flags & SPP_PMTUD_ENABLE ?
984 			 IP_PMTUDISC_DO : IP_PMTUDISC_DONT;
985 
986 	SCTP_INC_STATS(sock_net(&inet->sk), SCTP_MIB_OUTSCTPPACKS);
987 
988 	return ip_queue_xmit(&inet->sk, skb, &transport->fl);
989 }
990 
991 static struct sctp_af sctp_af_inet;
992 
993 static struct sctp_pf sctp_pf_inet = {
994 	.event_msgname = sctp_inet_event_msgname,
995 	.skb_msgname   = sctp_inet_skb_msgname,
996 	.af_supported  = sctp_inet_af_supported,
997 	.cmp_addr      = sctp_inet_cmp_addr,
998 	.bind_verify   = sctp_inet_bind_verify,
999 	.send_verify   = sctp_inet_send_verify,
1000 	.supported_addrs = sctp_inet_supported_addrs,
1001 	.create_accept_sk = sctp_v4_create_accept_sk,
1002 	.addr_to_user  = sctp_v4_addr_to_user,
1003 	.to_sk_saddr   = sctp_v4_to_sk_saddr,
1004 	.to_sk_daddr   = sctp_v4_to_sk_daddr,
1005 	.af            = &sctp_af_inet
1006 };
1007 
1008 /* Notifier for inetaddr addition/deletion events.  */
1009 static struct notifier_block sctp_inetaddr_notifier = {
1010 	.notifier_call = sctp_inetaddr_event,
1011 };
1012 
1013 /* Socket operations.  */
1014 static const struct proto_ops inet_seqpacket_ops = {
1015 	.family		   = PF_INET,
1016 	.owner		   = THIS_MODULE,
1017 	.release	   = inet_release,	/* Needs to be wrapped... */
1018 	.bind		   = inet_bind,
1019 	.connect	   = inet_dgram_connect,
1020 	.socketpair	   = sock_no_socketpair,
1021 	.accept		   = inet_accept,
1022 	.getname	   = inet_getname,	/* Semantics are different.  */
1023 	.poll		   = sctp_poll,
1024 	.ioctl		   = inet_ioctl,
1025 	.listen		   = sctp_inet_listen,
1026 	.shutdown	   = inet_shutdown,	/* Looks harmless.  */
1027 	.setsockopt	   = sock_common_setsockopt, /* IP_SOL IP_OPTION is a problem */
1028 	.getsockopt	   = sock_common_getsockopt,
1029 	.sendmsg	   = inet_sendmsg,
1030 	.recvmsg	   = sock_common_recvmsg,
1031 	.mmap		   = sock_no_mmap,
1032 	.sendpage	   = sock_no_sendpage,
1033 #ifdef CONFIG_COMPAT
1034 	.compat_setsockopt = compat_sock_common_setsockopt,
1035 	.compat_getsockopt = compat_sock_common_getsockopt,
1036 #endif
1037 };
1038 
1039 /* Registration with AF_INET family.  */
1040 static struct inet_protosw sctp_seqpacket_protosw = {
1041 	.type       = SOCK_SEQPACKET,
1042 	.protocol   = IPPROTO_SCTP,
1043 	.prot       = &sctp_prot,
1044 	.ops        = &inet_seqpacket_ops,
1045 	.flags      = SCTP_PROTOSW_FLAG
1046 };
1047 static struct inet_protosw sctp_stream_protosw = {
1048 	.type       = SOCK_STREAM,
1049 	.protocol   = IPPROTO_SCTP,
1050 	.prot       = &sctp_prot,
1051 	.ops        = &inet_seqpacket_ops,
1052 	.flags      = SCTP_PROTOSW_FLAG
1053 };
1054 
1055 /* Register with IP layer.  */
1056 static const struct net_protocol sctp_protocol = {
1057 	.handler     = sctp_rcv,
1058 	.err_handler = sctp_v4_err,
1059 	.no_policy   = 1,
1060 	.netns_ok    = 1,
1061 	.icmp_strict_tag_validation = 1,
1062 };
1063 
1064 /* IPv4 address related functions.  */
1065 static struct sctp_af sctp_af_inet = {
1066 	.sa_family	   = AF_INET,
1067 	.sctp_xmit	   = sctp_v4_xmit,
1068 	.setsockopt	   = ip_setsockopt,
1069 	.getsockopt	   = ip_getsockopt,
1070 	.get_dst	   = sctp_v4_get_dst,
1071 	.get_saddr	   = sctp_v4_get_saddr,
1072 	.copy_addrlist	   = sctp_v4_copy_addrlist,
1073 	.from_skb	   = sctp_v4_from_skb,
1074 	.from_sk	   = sctp_v4_from_sk,
1075 	.from_addr_param   = sctp_v4_from_addr_param,
1076 	.to_addr_param	   = sctp_v4_to_addr_param,
1077 	.cmp_addr	   = sctp_v4_cmp_addr,
1078 	.addr_valid	   = sctp_v4_addr_valid,
1079 	.inaddr_any	   = sctp_v4_inaddr_any,
1080 	.is_any		   = sctp_v4_is_any,
1081 	.available	   = sctp_v4_available,
1082 	.scope		   = sctp_v4_scope,
1083 	.skb_iif	   = sctp_v4_skb_iif,
1084 	.is_ce		   = sctp_v4_is_ce,
1085 	.seq_dump_addr	   = sctp_v4_seq_dump_addr,
1086 	.ecn_capable	   = sctp_v4_ecn_capable,
1087 	.net_header_len	   = sizeof(struct iphdr),
1088 	.sockaddr_len	   = sizeof(struct sockaddr_in),
1089 #ifdef CONFIG_COMPAT
1090 	.compat_setsockopt = compat_ip_setsockopt,
1091 	.compat_getsockopt = compat_ip_getsockopt,
1092 #endif
1093 };
1094 
1095 struct sctp_pf *sctp_get_pf_specific(sa_family_t family)
1096 {
1097 	switch (family) {
1098 	case PF_INET:
1099 		return sctp_pf_inet_specific;
1100 	case PF_INET6:
1101 		return sctp_pf_inet6_specific;
1102 	default:
1103 		return NULL;
1104 	}
1105 }
1106 
1107 /* Register the PF specific function table.  */
1108 int sctp_register_pf(struct sctp_pf *pf, sa_family_t family)
1109 {
1110 	switch (family) {
1111 	case PF_INET:
1112 		if (sctp_pf_inet_specific)
1113 			return 0;
1114 		sctp_pf_inet_specific = pf;
1115 		break;
1116 	case PF_INET6:
1117 		if (sctp_pf_inet6_specific)
1118 			return 0;
1119 		sctp_pf_inet6_specific = pf;
1120 		break;
1121 	default:
1122 		return 0;
1123 	}
1124 	return 1;
1125 }
1126 
1127 static inline int init_sctp_mibs(struct net *net)
1128 {
1129 	net->sctp.sctp_statistics = alloc_percpu(struct sctp_mib);
1130 	if (!net->sctp.sctp_statistics)
1131 		return -ENOMEM;
1132 	return 0;
1133 }
1134 
1135 static inline void cleanup_sctp_mibs(struct net *net)
1136 {
1137 	free_percpu(net->sctp.sctp_statistics);
1138 }
1139 
1140 static void sctp_v4_pf_init(void)
1141 {
1142 	/* Initialize the SCTP specific PF functions. */
1143 	sctp_register_pf(&sctp_pf_inet, PF_INET);
1144 	sctp_register_af(&sctp_af_inet);
1145 }
1146 
1147 static void sctp_v4_pf_exit(void)
1148 {
1149 	list_del(&sctp_af_inet.list);
1150 }
1151 
1152 static int sctp_v4_protosw_init(void)
1153 {
1154 	int rc;
1155 
1156 	rc = proto_register(&sctp_prot, 1);
1157 	if (rc)
1158 		return rc;
1159 
1160 	/* Register SCTP(UDP and TCP style) with socket layer.  */
1161 	inet_register_protosw(&sctp_seqpacket_protosw);
1162 	inet_register_protosw(&sctp_stream_protosw);
1163 
1164 	return 0;
1165 }
1166 
1167 static void sctp_v4_protosw_exit(void)
1168 {
1169 	inet_unregister_protosw(&sctp_stream_protosw);
1170 	inet_unregister_protosw(&sctp_seqpacket_protosw);
1171 	proto_unregister(&sctp_prot);
1172 }
1173 
1174 static int sctp_v4_add_protocol(void)
1175 {
1176 	/* Register notifier for inet address additions/deletions. */
1177 	register_inetaddr_notifier(&sctp_inetaddr_notifier);
1178 
1179 	/* Register SCTP with inet layer.  */
1180 	if (inet_add_protocol(&sctp_protocol, IPPROTO_SCTP) < 0)
1181 		return -EAGAIN;
1182 
1183 	return 0;
1184 }
1185 
1186 static void sctp_v4_del_protocol(void)
1187 {
1188 	inet_del_protocol(&sctp_protocol, IPPROTO_SCTP);
1189 	unregister_inetaddr_notifier(&sctp_inetaddr_notifier);
1190 }
1191 
1192 static int __net_init sctp_defaults_init(struct net *net)
1193 {
1194 	int status;
1195 
1196 	/*
1197 	 * 14. Suggested SCTP Protocol Parameter Values
1198 	 */
1199 	/* The following protocol parameters are RECOMMENDED:  */
1200 	/* RTO.Initial              - 3  seconds */
1201 	net->sctp.rto_initial			= SCTP_RTO_INITIAL;
1202 	/* RTO.Min                  - 1  second */
1203 	net->sctp.rto_min	 		= SCTP_RTO_MIN;
1204 	/* RTO.Max                 -  60 seconds */
1205 	net->sctp.rto_max 			= SCTP_RTO_MAX;
1206 	/* RTO.Alpha                - 1/8 */
1207 	net->sctp.rto_alpha			= SCTP_RTO_ALPHA;
1208 	/* RTO.Beta                 - 1/4 */
1209 	net->sctp.rto_beta			= SCTP_RTO_BETA;
1210 
1211 	/* Valid.Cookie.Life        - 60  seconds */
1212 	net->sctp.valid_cookie_life		= SCTP_DEFAULT_COOKIE_LIFE;
1213 
1214 	/* Whether Cookie Preservative is enabled(1) or not(0) */
1215 	net->sctp.cookie_preserve_enable 	= 1;
1216 
1217 	/* Default sctp sockets to use md5 as their hmac alg */
1218 #if defined (CONFIG_SCTP_DEFAULT_COOKIE_HMAC_MD5)
1219 	net->sctp.sctp_hmac_alg			= "md5";
1220 #elif defined (CONFIG_SCTP_DEFAULT_COOKIE_HMAC_SHA1)
1221 	net->sctp.sctp_hmac_alg			= "sha1";
1222 #else
1223 	net->sctp.sctp_hmac_alg			= NULL;
1224 #endif
1225 
1226 	/* Max.Burst		    - 4 */
1227 	net->sctp.max_burst			= SCTP_DEFAULT_MAX_BURST;
1228 
1229 	/* Enable pf state by default */
1230 	net->sctp.pf_enable = 1;
1231 
1232 	/* Association.Max.Retrans  - 10 attempts
1233 	 * Path.Max.Retrans         - 5  attempts (per destination address)
1234 	 * Max.Init.Retransmits     - 8  attempts
1235 	 */
1236 	net->sctp.max_retrans_association	= 10;
1237 	net->sctp.max_retrans_path		= 5;
1238 	net->sctp.max_retrans_init		= 8;
1239 
1240 	/* Sendbuffer growth	    - do per-socket accounting */
1241 	net->sctp.sndbuf_policy			= 0;
1242 
1243 	/* Rcvbuffer growth	    - do per-socket accounting */
1244 	net->sctp.rcvbuf_policy			= 0;
1245 
1246 	/* HB.interval              - 30 seconds */
1247 	net->sctp.hb_interval			= SCTP_DEFAULT_TIMEOUT_HEARTBEAT;
1248 
1249 	/* delayed SACK timeout */
1250 	net->sctp.sack_timeout			= SCTP_DEFAULT_TIMEOUT_SACK;
1251 
1252 	/* Disable ADDIP by default. */
1253 	net->sctp.addip_enable = 0;
1254 	net->sctp.addip_noauth = 0;
1255 	net->sctp.default_auto_asconf = 0;
1256 
1257 	/* Enable PR-SCTP by default. */
1258 	net->sctp.prsctp_enable = 1;
1259 
1260 	/* Disable AUTH by default. */
1261 	net->sctp.auth_enable = 0;
1262 
1263 	/* Set SCOPE policy to enabled */
1264 	net->sctp.scope_policy = SCTP_SCOPE_POLICY_ENABLE;
1265 
1266 	/* Set the default rwnd update threshold */
1267 	net->sctp.rwnd_upd_shift = SCTP_DEFAULT_RWND_SHIFT;
1268 
1269 	/* Initialize maximum autoclose timeout. */
1270 	net->sctp.max_autoclose		= INT_MAX / HZ;
1271 
1272 	status = sctp_sysctl_net_register(net);
1273 	if (status)
1274 		goto err_sysctl_register;
1275 
1276 	/* Allocate and initialise sctp mibs.  */
1277 	status = init_sctp_mibs(net);
1278 	if (status)
1279 		goto err_init_mibs;
1280 
1281 	/* Initialize proc fs directory.  */
1282 	status = sctp_proc_init(net);
1283 	if (status)
1284 		goto err_init_proc;
1285 
1286 	sctp_dbg_objcnt_init(net);
1287 
1288 	/* Initialize the local address list. */
1289 	INIT_LIST_HEAD(&net->sctp.local_addr_list);
1290 	spin_lock_init(&net->sctp.local_addr_lock);
1291 	sctp_get_local_addr_list(net);
1292 
1293 	/* Initialize the address event list */
1294 	INIT_LIST_HEAD(&net->sctp.addr_waitq);
1295 	INIT_LIST_HEAD(&net->sctp.auto_asconf_splist);
1296 	spin_lock_init(&net->sctp.addr_wq_lock);
1297 	net->sctp.addr_wq_timer.expires = 0;
1298 	setup_timer(&net->sctp.addr_wq_timer, sctp_addr_wq_timeout_handler,
1299 		    (unsigned long)net);
1300 
1301 	return 0;
1302 
1303 err_init_proc:
1304 	cleanup_sctp_mibs(net);
1305 err_init_mibs:
1306 	sctp_sysctl_net_unregister(net);
1307 err_sysctl_register:
1308 	return status;
1309 }
1310 
1311 static void __net_exit sctp_defaults_exit(struct net *net)
1312 {
1313 	/* Free the local address list */
1314 	sctp_free_addr_wq(net);
1315 	sctp_free_local_addr_list(net);
1316 
1317 	sctp_dbg_objcnt_exit(net);
1318 
1319 	sctp_proc_exit(net);
1320 	cleanup_sctp_mibs(net);
1321 	sctp_sysctl_net_unregister(net);
1322 }
1323 
1324 static struct pernet_operations sctp_defaults_ops = {
1325 	.init = sctp_defaults_init,
1326 	.exit = sctp_defaults_exit,
1327 };
1328 
1329 static int __net_init sctp_ctrlsock_init(struct net *net)
1330 {
1331 	int status;
1332 
1333 	/* Initialize the control inode/socket for handling OOTB packets.  */
1334 	status = sctp_ctl_sock_init(net);
1335 	if (status)
1336 		pr_err("Failed to initialize the SCTP control sock\n");
1337 
1338 	return status;
1339 }
1340 
1341 static void __net_init sctp_ctrlsock_exit(struct net *net)
1342 {
1343 	/* Free the control endpoint.  */
1344 	inet_ctl_sock_destroy(net->sctp.ctl_sock);
1345 }
1346 
1347 static struct pernet_operations sctp_ctrlsock_ops = {
1348 	.init = sctp_ctrlsock_init,
1349 	.exit = sctp_ctrlsock_exit,
1350 };
1351 
1352 /* Initialize the universe into something sensible.  */
1353 static __init int sctp_init(void)
1354 {
1355 	int i;
1356 	int status = -EINVAL;
1357 	unsigned long goal;
1358 	unsigned long limit;
1359 	int max_share;
1360 	int order;
1361 	int num_entries;
1362 	int max_entry_order;
1363 
1364 	sock_skb_cb_check_size(sizeof(struct sctp_ulpevent));
1365 
1366 	/* Allocate bind_bucket and chunk caches. */
1367 	status = -ENOBUFS;
1368 	sctp_bucket_cachep = kmem_cache_create("sctp_bind_bucket",
1369 					       sizeof(struct sctp_bind_bucket),
1370 					       0, SLAB_HWCACHE_ALIGN,
1371 					       NULL);
1372 	if (!sctp_bucket_cachep)
1373 		goto out;
1374 
1375 	sctp_chunk_cachep = kmem_cache_create("sctp_chunk",
1376 					       sizeof(struct sctp_chunk),
1377 					       0, SLAB_HWCACHE_ALIGN,
1378 					       NULL);
1379 	if (!sctp_chunk_cachep)
1380 		goto err_chunk_cachep;
1381 
1382 	status = percpu_counter_init(&sctp_sockets_allocated, 0, GFP_KERNEL);
1383 	if (status)
1384 		goto err_percpu_counter_init;
1385 
1386 	/* Implementation specific variables. */
1387 
1388 	/* Initialize default stream count setup information. */
1389 	sctp_max_instreams    		= SCTP_DEFAULT_INSTREAMS;
1390 	sctp_max_outstreams   		= SCTP_DEFAULT_OUTSTREAMS;
1391 
1392 	/* Initialize handle used for association ids. */
1393 	idr_init(&sctp_assocs_id);
1394 
1395 	limit = nr_free_buffer_pages() / 8;
1396 	limit = max(limit, 128UL);
1397 	sysctl_sctp_mem[0] = limit / 4 * 3;
1398 	sysctl_sctp_mem[1] = limit;
1399 	sysctl_sctp_mem[2] = sysctl_sctp_mem[0] * 2;
1400 
1401 	/* Set per-socket limits to no more than 1/128 the pressure threshold*/
1402 	limit = (sysctl_sctp_mem[1]) << (PAGE_SHIFT - 7);
1403 	max_share = min(4UL*1024*1024, limit);
1404 
1405 	sysctl_sctp_rmem[0] = SK_MEM_QUANTUM; /* give each asoc 1 page min */
1406 	sysctl_sctp_rmem[1] = 1500 * SKB_TRUESIZE(1);
1407 	sysctl_sctp_rmem[2] = max(sysctl_sctp_rmem[1], max_share);
1408 
1409 	sysctl_sctp_wmem[0] = SK_MEM_QUANTUM;
1410 	sysctl_sctp_wmem[1] = 16*1024;
1411 	sysctl_sctp_wmem[2] = max(64*1024, max_share);
1412 
1413 	/* Size and allocate the association hash table.
1414 	 * The methodology is similar to that of the tcp hash tables.
1415 	 * Though not identical.  Start by getting a goal size
1416 	 */
1417 	if (totalram_pages >= (128 * 1024))
1418 		goal = totalram_pages >> (22 - PAGE_SHIFT);
1419 	else
1420 		goal = totalram_pages >> (24 - PAGE_SHIFT);
1421 
1422 	/* Then compute the page order for said goal */
1423 	order = get_order(goal);
1424 
1425 	/* Now compute the required page order for the maximum sized table we
1426 	 * want to create
1427 	 */
1428 	max_entry_order = get_order(MAX_SCTP_PORT_HASH_ENTRIES *
1429 				    sizeof(struct sctp_bind_hashbucket));
1430 
1431 	/* Limit the page order by that maximum hash table size */
1432 	order = min(order, max_entry_order);
1433 
1434 	/* Allocate and initialize the endpoint hash table.  */
1435 	sctp_ep_hashsize = 64;
1436 	sctp_ep_hashtable =
1437 		kmalloc(64 * sizeof(struct sctp_hashbucket), GFP_KERNEL);
1438 	if (!sctp_ep_hashtable) {
1439 		pr_err("Failed endpoint_hash alloc\n");
1440 		status = -ENOMEM;
1441 		goto err_ehash_alloc;
1442 	}
1443 	for (i = 0; i < sctp_ep_hashsize; i++) {
1444 		rwlock_init(&sctp_ep_hashtable[i].lock);
1445 		INIT_HLIST_HEAD(&sctp_ep_hashtable[i].chain);
1446 	}
1447 
1448 	/* Allocate and initialize the SCTP port hash table.
1449 	 * Note that order is initalized to start at the max sized
1450 	 * table we want to support.  If we can't get that many pages
1451 	 * reduce the order and try again
1452 	 */
1453 	do {
1454 		sctp_port_hashtable = (struct sctp_bind_hashbucket *)
1455 			__get_free_pages(GFP_KERNEL | __GFP_NOWARN, order);
1456 	} while (!sctp_port_hashtable && --order > 0);
1457 
1458 	if (!sctp_port_hashtable) {
1459 		pr_err("Failed bind hash alloc\n");
1460 		status = -ENOMEM;
1461 		goto err_bhash_alloc;
1462 	}
1463 
1464 	/* Now compute the number of entries that will fit in the
1465 	 * port hash space we allocated
1466 	 */
1467 	num_entries = (1UL << order) * PAGE_SIZE /
1468 		      sizeof(struct sctp_bind_hashbucket);
1469 
1470 	/* And finish by rounding it down to the nearest power of two
1471 	 * this wastes some memory of course, but its needed because
1472 	 * the hash function operates based on the assumption that
1473 	 * that the number of entries is a power of two
1474 	 */
1475 	sctp_port_hashsize = rounddown_pow_of_two(num_entries);
1476 
1477 	for (i = 0; i < sctp_port_hashsize; i++) {
1478 		spin_lock_init(&sctp_port_hashtable[i].lock);
1479 		INIT_HLIST_HEAD(&sctp_port_hashtable[i].chain);
1480 	}
1481 
1482 	if (sctp_transport_hashtable_init())
1483 		goto err_thash_alloc;
1484 
1485 	pr_info("Hash tables configured (bind %d/%d)\n", sctp_port_hashsize,
1486 		num_entries);
1487 
1488 	sctp_sysctl_register();
1489 
1490 	INIT_LIST_HEAD(&sctp_address_families);
1491 	sctp_v4_pf_init();
1492 	sctp_v6_pf_init();
1493 
1494 	status = register_pernet_subsys(&sctp_defaults_ops);
1495 	if (status)
1496 		goto err_register_defaults;
1497 
1498 	status = sctp_v4_protosw_init();
1499 	if (status)
1500 		goto err_protosw_init;
1501 
1502 	status = sctp_v6_protosw_init();
1503 	if (status)
1504 		goto err_v6_protosw_init;
1505 
1506 	status = register_pernet_subsys(&sctp_ctrlsock_ops);
1507 	if (status)
1508 		goto err_register_ctrlsock;
1509 
1510 	status = sctp_v4_add_protocol();
1511 	if (status)
1512 		goto err_add_protocol;
1513 
1514 	/* Register SCTP with inet6 layer.  */
1515 	status = sctp_v6_add_protocol();
1516 	if (status)
1517 		goto err_v6_add_protocol;
1518 
1519 out:
1520 	return status;
1521 err_v6_add_protocol:
1522 	sctp_v4_del_protocol();
1523 err_add_protocol:
1524 	unregister_pernet_subsys(&sctp_ctrlsock_ops);
1525 err_register_ctrlsock:
1526 	sctp_v6_protosw_exit();
1527 err_v6_protosw_init:
1528 	sctp_v4_protosw_exit();
1529 err_protosw_init:
1530 	unregister_pernet_subsys(&sctp_defaults_ops);
1531 err_register_defaults:
1532 	sctp_v4_pf_exit();
1533 	sctp_v6_pf_exit();
1534 	sctp_sysctl_unregister();
1535 	free_pages((unsigned long)sctp_port_hashtable,
1536 		   get_order(sctp_port_hashsize *
1537 			     sizeof(struct sctp_bind_hashbucket)));
1538 err_bhash_alloc:
1539 	sctp_transport_hashtable_destroy();
1540 err_thash_alloc:
1541 	kfree(sctp_ep_hashtable);
1542 err_ehash_alloc:
1543 	percpu_counter_destroy(&sctp_sockets_allocated);
1544 err_percpu_counter_init:
1545 	kmem_cache_destroy(sctp_chunk_cachep);
1546 err_chunk_cachep:
1547 	kmem_cache_destroy(sctp_bucket_cachep);
1548 	goto out;
1549 }
1550 
1551 /* Exit handler for the SCTP protocol.  */
1552 static __exit void sctp_exit(void)
1553 {
1554 	/* BUG.  This should probably do something useful like clean
1555 	 * up all the remaining associations and all that memory.
1556 	 */
1557 
1558 	/* Unregister with inet6/inet layers. */
1559 	sctp_v6_del_protocol();
1560 	sctp_v4_del_protocol();
1561 
1562 	unregister_pernet_subsys(&sctp_ctrlsock_ops);
1563 
1564 	/* Free protosw registrations */
1565 	sctp_v6_protosw_exit();
1566 	sctp_v4_protosw_exit();
1567 
1568 	unregister_pernet_subsys(&sctp_defaults_ops);
1569 
1570 	/* Unregister with socket layer. */
1571 	sctp_v6_pf_exit();
1572 	sctp_v4_pf_exit();
1573 
1574 	sctp_sysctl_unregister();
1575 
1576 	free_pages((unsigned long)sctp_port_hashtable,
1577 		   get_order(sctp_port_hashsize *
1578 			     sizeof(struct sctp_bind_hashbucket)));
1579 	kfree(sctp_ep_hashtable);
1580 	sctp_transport_hashtable_destroy();
1581 
1582 	percpu_counter_destroy(&sctp_sockets_allocated);
1583 
1584 	rcu_barrier(); /* Wait for completion of call_rcu()'s */
1585 
1586 	kmem_cache_destroy(sctp_chunk_cachep);
1587 	kmem_cache_destroy(sctp_bucket_cachep);
1588 }
1589 
1590 module_init(sctp_init);
1591 module_exit(sctp_exit);
1592 
1593 /*
1594  * __stringify doesn't likes enums, so use IPPROTO_SCTP value (132) directly.
1595  */
1596 MODULE_ALIAS("net-pf-" __stringify(PF_INET) "-proto-132");
1597 MODULE_ALIAS("net-pf-" __stringify(PF_INET6) "-proto-132");
1598 MODULE_AUTHOR("Linux Kernel SCTP developers <linux-sctp@vger.kernel.org>");
1599 MODULE_DESCRIPTION("Support for the SCTP protocol (RFC2960)");
1600 module_param_named(no_checksums, sctp_checksum_disable, bool, 0644);
1601 MODULE_PARM_DESC(no_checksums, "Disable checksums computing and verification");
1602 MODULE_LICENSE("GPL");
1603