xref: /linux/net/sctp/protocol.c (revision ecd740c6f2f092b90b95fa35f757973589eaaca2)
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 /* Global data structures. */
64 struct sctp_globals sctp_globals __read_mostly;
65 
66 struct idr sctp_assocs_id;
67 DEFINE_SPINLOCK(sctp_assocs_id_lock);
68 
69 static struct sctp_pf *sctp_pf_inet6_specific;
70 static struct sctp_pf *sctp_pf_inet_specific;
71 static struct sctp_af *sctp_af_v4_specific;
72 static struct sctp_af *sctp_af_v6_specific;
73 
74 struct kmem_cache *sctp_chunk_cachep __read_mostly;
75 struct kmem_cache *sctp_bucket_cachep __read_mostly;
76 
77 long sysctl_sctp_mem[3];
78 int sysctl_sctp_rmem[3];
79 int sysctl_sctp_wmem[3];
80 
81 /* Set up the proc fs entry for the SCTP protocol. */
82 static int __net_init sctp_proc_init(struct net *net)
83 {
84 #ifdef CONFIG_PROC_FS
85 	net->sctp.proc_net_sctp = proc_net_mkdir(net, "sctp", net->proc_net);
86 	if (!net->sctp.proc_net_sctp)
87 		goto out_proc_net_sctp;
88 	if (sctp_snmp_proc_init(net))
89 		goto out_snmp_proc_init;
90 	if (sctp_eps_proc_init(net))
91 		goto out_eps_proc_init;
92 	if (sctp_assocs_proc_init(net))
93 		goto out_assocs_proc_init;
94 	if (sctp_remaddr_proc_init(net))
95 		goto out_remaddr_proc_init;
96 
97 	return 0;
98 
99 out_remaddr_proc_init:
100 	sctp_assocs_proc_exit(net);
101 out_assocs_proc_init:
102 	sctp_eps_proc_exit(net);
103 out_eps_proc_init:
104 	sctp_snmp_proc_exit(net);
105 out_snmp_proc_init:
106 	remove_proc_entry("sctp", net->proc_net);
107 	net->sctp.proc_net_sctp = NULL;
108 out_proc_net_sctp:
109 	return -ENOMEM;
110 #endif /* CONFIG_PROC_FS */
111 	return 0;
112 }
113 
114 /* Clean up the proc fs entry for the SCTP protocol.
115  * Note: Do not make this __exit as it is used in the init error
116  * path.
117  */
118 static void sctp_proc_exit(struct net *net)
119 {
120 #ifdef CONFIG_PROC_FS
121 	sctp_snmp_proc_exit(net);
122 	sctp_eps_proc_exit(net);
123 	sctp_assocs_proc_exit(net);
124 	sctp_remaddr_proc_exit(net);
125 
126 	remove_proc_entry("sctp", net->proc_net);
127 	net->sctp.proc_net_sctp = NULL;
128 #endif
129 }
130 
131 /* Private helper to extract ipv4 address and stash them in
132  * the protocol structure.
133  */
134 static void sctp_v4_copy_addrlist(struct list_head *addrlist,
135 				  struct net_device *dev)
136 {
137 	struct in_device *in_dev;
138 	struct in_ifaddr *ifa;
139 	struct sctp_sockaddr_entry *addr;
140 
141 	rcu_read_lock();
142 	if ((in_dev = __in_dev_get_rcu(dev)) == NULL) {
143 		rcu_read_unlock();
144 		return;
145 	}
146 
147 	for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) {
148 		/* Add the address to the local list.  */
149 		addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
150 		if (addr) {
151 			addr->a.v4.sin_family = AF_INET;
152 			addr->a.v4.sin_port = 0;
153 			addr->a.v4.sin_addr.s_addr = ifa->ifa_local;
154 			addr->valid = 1;
155 			INIT_LIST_HEAD(&addr->list);
156 			list_add_tail(&addr->list, addrlist);
157 		}
158 	}
159 
160 	rcu_read_unlock();
161 }
162 
163 /* Extract our IP addresses from the system and stash them in the
164  * protocol structure.
165  */
166 static void sctp_get_local_addr_list(struct net *net)
167 {
168 	struct net_device *dev;
169 	struct list_head *pos;
170 	struct sctp_af *af;
171 
172 	rcu_read_lock();
173 	for_each_netdev_rcu(net, dev) {
174 		list_for_each(pos, &sctp_address_families) {
175 			af = list_entry(pos, struct sctp_af, list);
176 			af->copy_addrlist(&net->sctp.local_addr_list, dev);
177 		}
178 	}
179 	rcu_read_unlock();
180 }
181 
182 /* Free the existing local addresses.  */
183 static void sctp_free_local_addr_list(struct net *net)
184 {
185 	struct sctp_sockaddr_entry *addr;
186 	struct list_head *pos, *temp;
187 
188 	list_for_each_safe(pos, temp, &net->sctp.local_addr_list) {
189 		addr = list_entry(pos, struct sctp_sockaddr_entry, list);
190 		list_del(pos);
191 		kfree(addr);
192 	}
193 }
194 
195 /* Copy the local addresses which are valid for 'scope' into 'bp'.  */
196 int sctp_copy_local_addr_list(struct net *net, struct sctp_bind_addr *bp,
197 			      sctp_scope_t scope, gfp_t gfp, int copy_flags)
198 {
199 	struct sctp_sockaddr_entry *addr;
200 	int error = 0;
201 
202 	rcu_read_lock();
203 	list_for_each_entry_rcu(addr, &net->sctp.local_addr_list, list) {
204 		if (!addr->valid)
205 			continue;
206 		if (sctp_in_scope(net, &addr->a, scope)) {
207 			/* Now that the address is in scope, check to see if
208 			 * the address type is really supported by the local
209 			 * sock as well as the remote peer.
210 			 */
211 			if ((((AF_INET == addr->a.sa.sa_family) &&
212 			      (copy_flags & SCTP_ADDR4_PEERSUPP))) ||
213 			    (((AF_INET6 == addr->a.sa.sa_family) &&
214 			      (copy_flags & SCTP_ADDR6_ALLOWED) &&
215 			      (copy_flags & SCTP_ADDR6_PEERSUPP)))) {
216 				error = sctp_add_bind_addr(bp, &addr->a,
217 						    SCTP_ADDR_SRC, GFP_ATOMIC);
218 				if (error)
219 					goto end_copy;
220 			}
221 		}
222 	}
223 
224 end_copy:
225 	rcu_read_unlock();
226 	return error;
227 }
228 
229 /* Initialize a sctp_addr from in incoming skb.  */
230 static void sctp_v4_from_skb(union sctp_addr *addr, struct sk_buff *skb,
231 			     int is_saddr)
232 {
233 	void *from;
234 	__be16 *port;
235 	struct sctphdr *sh;
236 
237 	port = &addr->v4.sin_port;
238 	addr->v4.sin_family = AF_INET;
239 
240 	sh = sctp_hdr(skb);
241 	if (is_saddr) {
242 		*port  = sh->source;
243 		from = &ip_hdr(skb)->saddr;
244 	} else {
245 		*port = sh->dest;
246 		from = &ip_hdr(skb)->daddr;
247 	}
248 	memcpy(&addr->v4.sin_addr.s_addr, from, sizeof(struct in_addr));
249 }
250 
251 /* Initialize an sctp_addr from a socket. */
252 static void sctp_v4_from_sk(union sctp_addr *addr, struct sock *sk)
253 {
254 	addr->v4.sin_family = AF_INET;
255 	addr->v4.sin_port = 0;
256 	addr->v4.sin_addr.s_addr = inet_sk(sk)->inet_rcv_saddr;
257 }
258 
259 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
260 static void sctp_v4_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
261 {
262 	inet_sk(sk)->inet_rcv_saddr = addr->v4.sin_addr.s_addr;
263 }
264 
265 /* Initialize sk->sk_daddr from sctp_addr. */
266 static void sctp_v4_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
267 {
268 	inet_sk(sk)->inet_daddr = addr->v4.sin_addr.s_addr;
269 }
270 
271 /* Initialize a sctp_addr from an address parameter. */
272 static void sctp_v4_from_addr_param(union sctp_addr *addr,
273 				    union sctp_addr_param *param,
274 				    __be16 port, int iif)
275 {
276 	addr->v4.sin_family = AF_INET;
277 	addr->v4.sin_port = port;
278 	addr->v4.sin_addr.s_addr = param->v4.addr.s_addr;
279 }
280 
281 /* Initialize an address parameter from a sctp_addr and return the length
282  * of the address parameter.
283  */
284 static int sctp_v4_to_addr_param(const union sctp_addr *addr,
285 				 union sctp_addr_param *param)
286 {
287 	int length = sizeof(sctp_ipv4addr_param_t);
288 
289 	param->v4.param_hdr.type = SCTP_PARAM_IPV4_ADDRESS;
290 	param->v4.param_hdr.length = htons(length);
291 	param->v4.addr.s_addr = addr->v4.sin_addr.s_addr;
292 
293 	return length;
294 }
295 
296 /* Initialize a sctp_addr from a dst_entry. */
297 static void sctp_v4_dst_saddr(union sctp_addr *saddr, struct flowi4 *fl4,
298 			      __be16 port)
299 {
300 	saddr->v4.sin_family = AF_INET;
301 	saddr->v4.sin_port = port;
302 	saddr->v4.sin_addr.s_addr = fl4->saddr;
303 }
304 
305 /* Compare two addresses exactly. */
306 static int sctp_v4_cmp_addr(const union sctp_addr *addr1,
307 			    const union sctp_addr *addr2)
308 {
309 	if (addr1->sa.sa_family != addr2->sa.sa_family)
310 		return 0;
311 	if (addr1->v4.sin_port != addr2->v4.sin_port)
312 		return 0;
313 	if (addr1->v4.sin_addr.s_addr != addr2->v4.sin_addr.s_addr)
314 		return 0;
315 
316 	return 1;
317 }
318 
319 /* Initialize addr struct to INADDR_ANY. */
320 static void sctp_v4_inaddr_any(union sctp_addr *addr, __be16 port)
321 {
322 	addr->v4.sin_family = AF_INET;
323 	addr->v4.sin_addr.s_addr = htonl(INADDR_ANY);
324 	addr->v4.sin_port = port;
325 }
326 
327 /* Is this a wildcard address? */
328 static int sctp_v4_is_any(const union sctp_addr *addr)
329 {
330 	return htonl(INADDR_ANY) == addr->v4.sin_addr.s_addr;
331 }
332 
333 /* This function checks if the address is a valid address to be used for
334  * SCTP binding.
335  *
336  * Output:
337  * Return 0 - If the address is a non-unicast or an illegal address.
338  * Return 1 - If the address is a unicast.
339  */
340 static int sctp_v4_addr_valid(union sctp_addr *addr,
341 			      struct sctp_sock *sp,
342 			      const struct sk_buff *skb)
343 {
344 	/* IPv4 addresses not allowed */
345 	if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
346 		return 0;
347 
348 	/* Is this a non-unicast address or a unusable SCTP address? */
349 	if (IS_IPV4_UNUSABLE_ADDRESS(addr->v4.sin_addr.s_addr))
350 		return 0;
351 
352 	/* Is this a broadcast address? */
353 	if (skb && skb_rtable(skb)->rt_flags & RTCF_BROADCAST)
354 		return 0;
355 
356 	return 1;
357 }
358 
359 /* Should this be available for binding?   */
360 static int sctp_v4_available(union sctp_addr *addr, struct sctp_sock *sp)
361 {
362 	struct net *net = sock_net(&sp->inet.sk);
363 	int ret = inet_addr_type(net, addr->v4.sin_addr.s_addr);
364 
365 
366 	if (addr->v4.sin_addr.s_addr != htonl(INADDR_ANY) &&
367 	   ret != RTN_LOCAL &&
368 	   !sp->inet.freebind &&
369 	   !sysctl_ip_nonlocal_bind)
370 		return 0;
371 
372 	if (ipv6_only_sock(sctp_opt2sk(sp)))
373 		return 0;
374 
375 	return 1;
376 }
377 
378 /* Checking the loopback, private and other address scopes as defined in
379  * RFC 1918.   The IPv4 scoping is based on the draft for SCTP IPv4
380  * scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>.
381  *
382  * Level 0 - unusable SCTP addresses
383  * Level 1 - loopback address
384  * Level 2 - link-local addresses
385  * Level 3 - private addresses.
386  * Level 4 - global addresses
387  * For INIT and INIT-ACK address list, let L be the level of
388  * of requested destination address, sender and receiver
389  * SHOULD include all of its addresses with level greater
390  * than or equal to L.
391  *
392  * IPv4 scoping can be controlled through sysctl option
393  * net.sctp.addr_scope_policy
394  */
395 static sctp_scope_t sctp_v4_scope(union sctp_addr *addr)
396 {
397 	sctp_scope_t retval;
398 
399 	/* Check for unusable SCTP addresses. */
400 	if (IS_IPV4_UNUSABLE_ADDRESS(addr->v4.sin_addr.s_addr)) {
401 		retval =  SCTP_SCOPE_UNUSABLE;
402 	} else if (ipv4_is_loopback(addr->v4.sin_addr.s_addr)) {
403 		retval = SCTP_SCOPE_LOOPBACK;
404 	} else if (ipv4_is_linklocal_169(addr->v4.sin_addr.s_addr)) {
405 		retval = SCTP_SCOPE_LINK;
406 	} else if (ipv4_is_private_10(addr->v4.sin_addr.s_addr) ||
407 		   ipv4_is_private_172(addr->v4.sin_addr.s_addr) ||
408 		   ipv4_is_private_192(addr->v4.sin_addr.s_addr)) {
409 		retval = SCTP_SCOPE_PRIVATE;
410 	} else {
411 		retval = SCTP_SCOPE_GLOBAL;
412 	}
413 
414 	return retval;
415 }
416 
417 /* Returns a valid dst cache entry for the given source and destination ip
418  * addresses. If an association is passed, trys to get a dst entry with a
419  * source address that matches an address in the bind address list.
420  */
421 static void sctp_v4_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
422 				struct flowi *fl, struct sock *sk)
423 {
424 	struct sctp_association *asoc = t->asoc;
425 	struct rtable *rt;
426 	struct flowi4 *fl4 = &fl->u.ip4;
427 	struct sctp_bind_addr *bp;
428 	struct sctp_sockaddr_entry *laddr;
429 	struct dst_entry *dst = NULL;
430 	union sctp_addr *daddr = &t->ipaddr;
431 	union sctp_addr dst_saddr;
432 
433 	memset(fl4, 0x0, sizeof(struct flowi4));
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_CONN_FLAGS(asoc->base.sk);
439 		fl4->flowi4_oif = asoc->base.sk->sk_bound_dev_if;
440 		fl4->fl4_sport = htons(asoc->base.bind_addr.port);
441 	}
442 	if (saddr) {
443 		fl4->saddr = saddr->v4.sin_addr.s_addr;
444 		fl4->fl4_sport = saddr->v4.sin_port;
445 	}
446 
447 	pr_debug("%s: dst:%pI4, src:%pI4 - ", __func__, &fl4->daddr,
448 		 &fl4->saddr);
449 
450 	rt = ip_route_output_key(sock_net(sk), fl4);
451 	if (!IS_ERR(rt))
452 		dst = &rt->dst;
453 
454 	/* If there is no association or if a source address is passed, no
455 	 * more validation is required.
456 	 */
457 	if (!asoc || saddr)
458 		goto out;
459 
460 	bp = &asoc->base.bind_addr;
461 
462 	if (dst) {
463 		/* Walk through the bind address list and look for a bind
464 		 * address that matches the source address of the returned dst.
465 		 */
466 		sctp_v4_dst_saddr(&dst_saddr, fl4, htons(bp->port));
467 		rcu_read_lock();
468 		list_for_each_entry_rcu(laddr, &bp->address_list, list) {
469 			if (!laddr->valid || (laddr->state == SCTP_ADDR_DEL) ||
470 			    (laddr->state != SCTP_ADDR_SRC &&
471 			    !asoc->src_out_of_asoc_ok))
472 				continue;
473 			if (sctp_v4_cmp_addr(&dst_saddr, &laddr->a))
474 				goto out_unlock;
475 		}
476 		rcu_read_unlock();
477 
478 		/* None of the bound addresses match the source address of the
479 		 * dst. So release it.
480 		 */
481 		dst_release(dst);
482 		dst = NULL;
483 	}
484 
485 	/* Walk through the bind address list and try to get a dst that
486 	 * matches a bind address as the source address.
487 	 */
488 	rcu_read_lock();
489 	list_for_each_entry_rcu(laddr, &bp->address_list, list) {
490 		if (!laddr->valid)
491 			continue;
492 		if ((laddr->state == SCTP_ADDR_SRC) &&
493 		    (AF_INET == laddr->a.sa.sa_family)) {
494 			fl4->saddr = laddr->a.v4.sin_addr.s_addr;
495 			fl4->fl4_sport = laddr->a.v4.sin_port;
496 			rt = ip_route_output_key(sock_net(sk), fl4);
497 			if (!IS_ERR(rt)) {
498 				dst = &rt->dst;
499 				goto out_unlock;
500 			}
501 		}
502 	}
503 
504 out_unlock:
505 	rcu_read_unlock();
506 out:
507 	t->dst = dst;
508 	if (dst)
509 		pr_debug("rt_dst:%pI4, rt_src:%pI4\n",
510 			 &fl4->daddr, &fl4->saddr);
511 	else
512 		pr_debug("no route\n");
513 }
514 
515 /* For v4, the source address is cached in the route entry(dst). So no need
516  * to cache it separately and hence this is an empty routine.
517  */
518 static void sctp_v4_get_saddr(struct sctp_sock *sk,
519 			      struct sctp_transport *t,
520 			      struct flowi *fl)
521 {
522 	union sctp_addr *saddr = &t->saddr;
523 	struct rtable *rt = (struct rtable *)t->dst;
524 
525 	if (rt) {
526 		saddr->v4.sin_family = AF_INET;
527 		saddr->v4.sin_addr.s_addr = fl->u.ip4.saddr;
528 	}
529 }
530 
531 /* What interface did this skb arrive on? */
532 static int sctp_v4_skb_iif(const struct sk_buff *skb)
533 {
534 	return inet_iif(skb);
535 }
536 
537 /* Was this packet marked by Explicit Congestion Notification? */
538 static int sctp_v4_is_ce(const struct sk_buff *skb)
539 {
540 	return INET_ECN_is_ce(ip_hdr(skb)->tos);
541 }
542 
543 /* Create and initialize a new sk for the socket returned by accept(). */
544 static struct sock *sctp_v4_create_accept_sk(struct sock *sk,
545 					     struct sctp_association *asoc)
546 {
547 	struct sock *newsk = sk_alloc(sock_net(sk), PF_INET, GFP_KERNEL,
548 			sk->sk_prot);
549 	struct inet_sock *newinet;
550 
551 	if (!newsk)
552 		goto out;
553 
554 	sock_init_data(NULL, newsk);
555 
556 	sctp_copy_sock(newsk, sk, asoc);
557 	sock_reset_flag(newsk, SOCK_ZAPPED);
558 
559 	newinet = inet_sk(newsk);
560 
561 	newinet->inet_daddr = asoc->peer.primary_addr.v4.sin_addr.s_addr;
562 
563 	sk_refcnt_debug_inc(newsk);
564 
565 	if (newsk->sk_prot->init(newsk)) {
566 		sk_common_release(newsk);
567 		newsk = NULL;
568 	}
569 
570 out:
571 	return newsk;
572 }
573 
574 /* Map address, empty for v4 family */
575 static void sctp_v4_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
576 {
577 	/* Empty */
578 }
579 
580 /* Dump the v4 addr to the seq file. */
581 static void sctp_v4_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
582 {
583 	seq_printf(seq, "%pI4 ", &addr->v4.sin_addr);
584 }
585 
586 static void sctp_v4_ecn_capable(struct sock *sk)
587 {
588 	INET_ECN_xmit(sk);
589 }
590 
591 static void sctp_addr_wq_timeout_handler(unsigned long arg)
592 {
593 	struct net *net = (struct net *)arg;
594 	struct sctp_sockaddr_entry *addrw, *temp;
595 	struct sctp_sock *sp;
596 
597 	spin_lock_bh(&net->sctp.addr_wq_lock);
598 
599 	list_for_each_entry_safe(addrw, temp, &net->sctp.addr_waitq, list) {
600 		pr_debug("%s: the first ent in wq:%p is addr:%pISc for cmd:%d at "
601 			 "entry:%p\n", __func__, &net->sctp.addr_waitq, &addrw->a.sa,
602 			 addrw->state, addrw);
603 
604 #if IS_ENABLED(CONFIG_IPV6)
605 		/* Now we send an ASCONF for each association */
606 		/* Note. we currently don't handle link local IPv6 addressees */
607 		if (addrw->a.sa.sa_family == AF_INET6) {
608 			struct in6_addr *in6;
609 
610 			if (ipv6_addr_type(&addrw->a.v6.sin6_addr) &
611 			    IPV6_ADDR_LINKLOCAL)
612 				goto free_next;
613 
614 			in6 = (struct in6_addr *)&addrw->a.v6.sin6_addr;
615 			if (ipv6_chk_addr(net, in6, NULL, 0) == 0 &&
616 			    addrw->state == SCTP_ADDR_NEW) {
617 				unsigned long timeo_val;
618 
619 				pr_debug("%s: this is on DAD, trying %d sec "
620 					 "later\n", __func__,
621 					 SCTP_ADDRESS_TICK_DELAY);
622 
623 				timeo_val = jiffies;
624 				timeo_val += msecs_to_jiffies(SCTP_ADDRESS_TICK_DELAY);
625 				mod_timer(&net->sctp.addr_wq_timer, timeo_val);
626 				break;
627 			}
628 		}
629 #endif
630 		list_for_each_entry(sp, &net->sctp.auto_asconf_splist, auto_asconf_list) {
631 			struct sock *sk;
632 
633 			sk = sctp_opt2sk(sp);
634 			/* ignore bound-specific endpoints */
635 			if (!sctp_is_ep_boundall(sk))
636 				continue;
637 			bh_lock_sock(sk);
638 			if (sctp_asconf_mgmt(sp, addrw) < 0)
639 				pr_debug("%s: sctp_asconf_mgmt failed\n", __func__);
640 			bh_unlock_sock(sk);
641 		}
642 #if IS_ENABLED(CONFIG_IPV6)
643 free_next:
644 #endif
645 		list_del(&addrw->list);
646 		kfree(addrw);
647 	}
648 	spin_unlock_bh(&net->sctp.addr_wq_lock);
649 }
650 
651 static void sctp_free_addr_wq(struct net *net)
652 {
653 	struct sctp_sockaddr_entry *addrw;
654 	struct sctp_sockaddr_entry *temp;
655 
656 	spin_lock_bh(&net->sctp.addr_wq_lock);
657 	del_timer(&net->sctp.addr_wq_timer);
658 	list_for_each_entry_safe(addrw, temp, &net->sctp.addr_waitq, list) {
659 		list_del(&addrw->list);
660 		kfree(addrw);
661 	}
662 	spin_unlock_bh(&net->sctp.addr_wq_lock);
663 }
664 
665 /* lookup the entry for the same address in the addr_waitq
666  * sctp_addr_wq MUST be locked
667  */
668 static struct sctp_sockaddr_entry *sctp_addr_wq_lookup(struct net *net,
669 					struct sctp_sockaddr_entry *addr)
670 {
671 	struct sctp_sockaddr_entry *addrw;
672 
673 	list_for_each_entry(addrw, &net->sctp.addr_waitq, list) {
674 		if (addrw->a.sa.sa_family != addr->a.sa.sa_family)
675 			continue;
676 		if (addrw->a.sa.sa_family == AF_INET) {
677 			if (addrw->a.v4.sin_addr.s_addr ==
678 			    addr->a.v4.sin_addr.s_addr)
679 				return addrw;
680 		} else if (addrw->a.sa.sa_family == AF_INET6) {
681 			if (ipv6_addr_equal(&addrw->a.v6.sin6_addr,
682 			    &addr->a.v6.sin6_addr))
683 				return addrw;
684 		}
685 	}
686 	return NULL;
687 }
688 
689 void sctp_addr_wq_mgmt(struct net *net, struct sctp_sockaddr_entry *addr, int cmd)
690 {
691 	struct sctp_sockaddr_entry *addrw;
692 	unsigned long timeo_val;
693 
694 	/* first, we check if an opposite message already exist in the queue.
695 	 * If we found such message, it is removed.
696 	 * This operation is a bit stupid, but the DHCP client attaches the
697 	 * new address after a couple of addition and deletion of that address
698 	 */
699 
700 	spin_lock_bh(&net->sctp.addr_wq_lock);
701 	/* Offsets existing events in addr_wq */
702 	addrw = sctp_addr_wq_lookup(net, addr);
703 	if (addrw) {
704 		if (addrw->state != cmd) {
705 			pr_debug("%s: offsets existing entry for %d, addr:%pISc "
706 				 "in wq:%p\n", __func__, addrw->state, &addrw->a.sa,
707 				 &net->sctp.addr_waitq);
708 
709 			list_del(&addrw->list);
710 			kfree(addrw);
711 		}
712 		spin_unlock_bh(&net->sctp.addr_wq_lock);
713 		return;
714 	}
715 
716 	/* OK, we have to add the new address to the wait queue */
717 	addrw = kmemdup(addr, sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
718 	if (addrw == NULL) {
719 		spin_unlock_bh(&net->sctp.addr_wq_lock);
720 		return;
721 	}
722 	addrw->state = cmd;
723 	list_add_tail(&addrw->list, &net->sctp.addr_waitq);
724 
725 	pr_debug("%s: add new entry for cmd:%d, addr:%pISc in wq:%p\n",
726 		 __func__, addrw->state, &addrw->a.sa, &net->sctp.addr_waitq);
727 
728 	if (!timer_pending(&net->sctp.addr_wq_timer)) {
729 		timeo_val = jiffies;
730 		timeo_val += msecs_to_jiffies(SCTP_ADDRESS_TICK_DELAY);
731 		mod_timer(&net->sctp.addr_wq_timer, timeo_val);
732 	}
733 	spin_unlock_bh(&net->sctp.addr_wq_lock);
734 }
735 
736 /* Event handler for inet address addition/deletion events.
737  * The sctp_local_addr_list needs to be protocted by a spin lock since
738  * multiple notifiers (say IPv4 and IPv6) may be running at the same
739  * time and thus corrupt the list.
740  * The reader side is protected with RCU.
741  */
742 static int sctp_inetaddr_event(struct notifier_block *this, unsigned long ev,
743 			       void *ptr)
744 {
745 	struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
746 	struct sctp_sockaddr_entry *addr = NULL;
747 	struct sctp_sockaddr_entry *temp;
748 	struct net *net = dev_net(ifa->ifa_dev->dev);
749 	int found = 0;
750 
751 	switch (ev) {
752 	case NETDEV_UP:
753 		addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
754 		if (addr) {
755 			addr->a.v4.sin_family = AF_INET;
756 			addr->a.v4.sin_port = 0;
757 			addr->a.v4.sin_addr.s_addr = ifa->ifa_local;
758 			addr->valid = 1;
759 			spin_lock_bh(&net->sctp.local_addr_lock);
760 			list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
761 			sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
762 			spin_unlock_bh(&net->sctp.local_addr_lock);
763 		}
764 		break;
765 	case NETDEV_DOWN:
766 		spin_lock_bh(&net->sctp.local_addr_lock);
767 		list_for_each_entry_safe(addr, temp,
768 					&net->sctp.local_addr_list, list) {
769 			if (addr->a.sa.sa_family == AF_INET &&
770 					addr->a.v4.sin_addr.s_addr ==
771 					ifa->ifa_local) {
772 				sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
773 				found = 1;
774 				addr->valid = 0;
775 				list_del_rcu(&addr->list);
776 				break;
777 			}
778 		}
779 		spin_unlock_bh(&net->sctp.local_addr_lock);
780 		if (found)
781 			kfree_rcu(addr, rcu);
782 		break;
783 	}
784 
785 	return NOTIFY_DONE;
786 }
787 
788 /*
789  * Initialize the control inode/socket with a control endpoint data
790  * structure.  This endpoint is reserved exclusively for the OOTB processing.
791  */
792 static int sctp_ctl_sock_init(struct net *net)
793 {
794 	int err;
795 	sa_family_t family = PF_INET;
796 
797 	if (sctp_get_pf_specific(PF_INET6))
798 		family = PF_INET6;
799 
800 	err = inet_ctl_sock_create(&net->sctp.ctl_sock, family,
801 				   SOCK_SEQPACKET, IPPROTO_SCTP, net);
802 
803 	/* If IPv6 socket could not be created, try the IPv4 socket */
804 	if (err < 0 && family == PF_INET6)
805 		err = inet_ctl_sock_create(&net->sctp.ctl_sock, AF_INET,
806 					   SOCK_SEQPACKET, IPPROTO_SCTP,
807 					   net);
808 
809 	if (err < 0) {
810 		pr_err("Failed to create the SCTP control socket\n");
811 		return err;
812 	}
813 	return 0;
814 }
815 
816 /* Register address family specific functions. */
817 int sctp_register_af(struct sctp_af *af)
818 {
819 	switch (af->sa_family) {
820 	case AF_INET:
821 		if (sctp_af_v4_specific)
822 			return 0;
823 		sctp_af_v4_specific = af;
824 		break;
825 	case AF_INET6:
826 		if (sctp_af_v6_specific)
827 			return 0;
828 		sctp_af_v6_specific = af;
829 		break;
830 	default:
831 		return 0;
832 	}
833 
834 	INIT_LIST_HEAD(&af->list);
835 	list_add_tail(&af->list, &sctp_address_families);
836 	return 1;
837 }
838 
839 /* Get the table of functions for manipulating a particular address
840  * family.
841  */
842 struct sctp_af *sctp_get_af_specific(sa_family_t family)
843 {
844 	switch (family) {
845 	case AF_INET:
846 		return sctp_af_v4_specific;
847 	case AF_INET6:
848 		return sctp_af_v6_specific;
849 	default:
850 		return NULL;
851 	}
852 }
853 
854 /* Common code to initialize a AF_INET msg_name. */
855 static void sctp_inet_msgname(char *msgname, int *addr_len)
856 {
857 	struct sockaddr_in *sin;
858 
859 	sin = (struct sockaddr_in *)msgname;
860 	*addr_len = sizeof(struct sockaddr_in);
861 	sin->sin_family = AF_INET;
862 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
863 }
864 
865 /* Copy the primary address of the peer primary address as the msg_name. */
866 static void sctp_inet_event_msgname(struct sctp_ulpevent *event, char *msgname,
867 				    int *addr_len)
868 {
869 	struct sockaddr_in *sin, *sinfrom;
870 
871 	if (msgname) {
872 		struct sctp_association *asoc;
873 
874 		asoc = event->asoc;
875 		sctp_inet_msgname(msgname, addr_len);
876 		sin = (struct sockaddr_in *)msgname;
877 		sinfrom = &asoc->peer.primary_addr.v4;
878 		sin->sin_port = htons(asoc->peer.port);
879 		sin->sin_addr.s_addr = sinfrom->sin_addr.s_addr;
880 	}
881 }
882 
883 /* Initialize and copy out a msgname from an inbound skb. */
884 static void sctp_inet_skb_msgname(struct sk_buff *skb, char *msgname, int *len)
885 {
886 	if (msgname) {
887 		struct sctphdr *sh = sctp_hdr(skb);
888 		struct sockaddr_in *sin = (struct sockaddr_in *)msgname;
889 
890 		sctp_inet_msgname(msgname, len);
891 		sin->sin_port = sh->source;
892 		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
893 	}
894 }
895 
896 /* Do we support this AF? */
897 static int sctp_inet_af_supported(sa_family_t family, struct sctp_sock *sp)
898 {
899 	/* PF_INET only supports AF_INET addresses. */
900 	return AF_INET == family;
901 }
902 
903 /* Address matching with wildcards allowed. */
904 static int sctp_inet_cmp_addr(const union sctp_addr *addr1,
905 			      const union sctp_addr *addr2,
906 			      struct sctp_sock *opt)
907 {
908 	/* PF_INET only supports AF_INET addresses. */
909 	if (addr1->sa.sa_family != addr2->sa.sa_family)
910 		return 0;
911 	if (htonl(INADDR_ANY) == addr1->v4.sin_addr.s_addr ||
912 	    htonl(INADDR_ANY) == addr2->v4.sin_addr.s_addr)
913 		return 1;
914 	if (addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr)
915 		return 1;
916 
917 	return 0;
918 }
919 
920 /* Verify that provided sockaddr looks bindable.  Common verification has
921  * already been taken care of.
922  */
923 static int sctp_inet_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
924 {
925 	return sctp_v4_available(addr, opt);
926 }
927 
928 /* Verify that sockaddr looks sendable.  Common verification has already
929  * been taken care of.
930  */
931 static int sctp_inet_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
932 {
933 	return 1;
934 }
935 
936 /* Fill in Supported Address Type information for INIT and INIT-ACK
937  * chunks.  Returns number of addresses supported.
938  */
939 static int sctp_inet_supported_addrs(const struct sctp_sock *opt,
940 				     __be16 *types)
941 {
942 	types[0] = SCTP_PARAM_IPV4_ADDRESS;
943 	return 1;
944 }
945 
946 /* Wrapper routine that calls the ip transmit routine. */
947 static inline int sctp_v4_xmit(struct sk_buff *skb,
948 			       struct sctp_transport *transport)
949 {
950 	struct inet_sock *inet = inet_sk(skb->sk);
951 
952 	pr_debug("%s: skb:%p, len:%d, src:%pI4, dst:%pI4\n", __func__, skb,
953 		 skb->len, &transport->fl.u.ip4.saddr, &transport->fl.u.ip4.daddr);
954 
955 	inet->pmtudisc = transport->param_flags & SPP_PMTUD_ENABLE ?
956 			 IP_PMTUDISC_DO : IP_PMTUDISC_DONT;
957 
958 	SCTP_INC_STATS(sock_net(&inet->sk), SCTP_MIB_OUTSCTPPACKS);
959 
960 	return ip_queue_xmit(skb, &transport->fl);
961 }
962 
963 static struct sctp_af sctp_af_inet;
964 
965 static struct sctp_pf sctp_pf_inet = {
966 	.event_msgname = sctp_inet_event_msgname,
967 	.skb_msgname   = sctp_inet_skb_msgname,
968 	.af_supported  = sctp_inet_af_supported,
969 	.cmp_addr      = sctp_inet_cmp_addr,
970 	.bind_verify   = sctp_inet_bind_verify,
971 	.send_verify   = sctp_inet_send_verify,
972 	.supported_addrs = sctp_inet_supported_addrs,
973 	.create_accept_sk = sctp_v4_create_accept_sk,
974 	.addr_v4map	= sctp_v4_addr_v4map,
975 	.af            = &sctp_af_inet
976 };
977 
978 /* Notifier for inetaddr addition/deletion events.  */
979 static struct notifier_block sctp_inetaddr_notifier = {
980 	.notifier_call = sctp_inetaddr_event,
981 };
982 
983 /* Socket operations.  */
984 static const struct proto_ops inet_seqpacket_ops = {
985 	.family		   = PF_INET,
986 	.owner		   = THIS_MODULE,
987 	.release	   = inet_release,	/* Needs to be wrapped... */
988 	.bind		   = inet_bind,
989 	.connect	   = inet_dgram_connect,
990 	.socketpair	   = sock_no_socketpair,
991 	.accept		   = inet_accept,
992 	.getname	   = inet_getname,	/* Semantics are different.  */
993 	.poll		   = sctp_poll,
994 	.ioctl		   = inet_ioctl,
995 	.listen		   = sctp_inet_listen,
996 	.shutdown	   = inet_shutdown,	/* Looks harmless.  */
997 	.setsockopt	   = sock_common_setsockopt, /* IP_SOL IP_OPTION is a problem */
998 	.getsockopt	   = sock_common_getsockopt,
999 	.sendmsg	   = inet_sendmsg,
1000 	.recvmsg	   = sock_common_recvmsg,
1001 	.mmap		   = sock_no_mmap,
1002 	.sendpage	   = sock_no_sendpage,
1003 #ifdef CONFIG_COMPAT
1004 	.compat_setsockopt = compat_sock_common_setsockopt,
1005 	.compat_getsockopt = compat_sock_common_getsockopt,
1006 #endif
1007 };
1008 
1009 /* Registration with AF_INET family.  */
1010 static struct inet_protosw sctp_seqpacket_protosw = {
1011 	.type       = SOCK_SEQPACKET,
1012 	.protocol   = IPPROTO_SCTP,
1013 	.prot       = &sctp_prot,
1014 	.ops        = &inet_seqpacket_ops,
1015 	.no_check   = 0,
1016 	.flags      = SCTP_PROTOSW_FLAG
1017 };
1018 static struct inet_protosw sctp_stream_protosw = {
1019 	.type       = SOCK_STREAM,
1020 	.protocol   = IPPROTO_SCTP,
1021 	.prot       = &sctp_prot,
1022 	.ops        = &inet_seqpacket_ops,
1023 	.no_check   = 0,
1024 	.flags      = SCTP_PROTOSW_FLAG
1025 };
1026 
1027 /* Register with IP layer.  */
1028 static const struct net_protocol sctp_protocol = {
1029 	.handler     = sctp_rcv,
1030 	.err_handler = sctp_v4_err,
1031 	.no_policy   = 1,
1032 	.netns_ok    = 1,
1033 	.icmp_strict_tag_validation = 1,
1034 };
1035 
1036 /* IPv4 address related functions.  */
1037 static struct sctp_af sctp_af_inet = {
1038 	.sa_family	   = AF_INET,
1039 	.sctp_xmit	   = sctp_v4_xmit,
1040 	.setsockopt	   = ip_setsockopt,
1041 	.getsockopt	   = ip_getsockopt,
1042 	.get_dst	   = sctp_v4_get_dst,
1043 	.get_saddr	   = sctp_v4_get_saddr,
1044 	.copy_addrlist	   = sctp_v4_copy_addrlist,
1045 	.from_skb	   = sctp_v4_from_skb,
1046 	.from_sk	   = sctp_v4_from_sk,
1047 	.to_sk_saddr	   = sctp_v4_to_sk_saddr,
1048 	.to_sk_daddr	   = sctp_v4_to_sk_daddr,
1049 	.from_addr_param   = sctp_v4_from_addr_param,
1050 	.to_addr_param	   = sctp_v4_to_addr_param,
1051 	.cmp_addr	   = sctp_v4_cmp_addr,
1052 	.addr_valid	   = sctp_v4_addr_valid,
1053 	.inaddr_any	   = sctp_v4_inaddr_any,
1054 	.is_any		   = sctp_v4_is_any,
1055 	.available	   = sctp_v4_available,
1056 	.scope		   = sctp_v4_scope,
1057 	.skb_iif	   = sctp_v4_skb_iif,
1058 	.is_ce		   = sctp_v4_is_ce,
1059 	.seq_dump_addr	   = sctp_v4_seq_dump_addr,
1060 	.ecn_capable	   = sctp_v4_ecn_capable,
1061 	.net_header_len	   = sizeof(struct iphdr),
1062 	.sockaddr_len	   = sizeof(struct sockaddr_in),
1063 #ifdef CONFIG_COMPAT
1064 	.compat_setsockopt = compat_ip_setsockopt,
1065 	.compat_getsockopt = compat_ip_getsockopt,
1066 #endif
1067 };
1068 
1069 struct sctp_pf *sctp_get_pf_specific(sa_family_t family)
1070 {
1071 	switch (family) {
1072 	case PF_INET:
1073 		return sctp_pf_inet_specific;
1074 	case PF_INET6:
1075 		return sctp_pf_inet6_specific;
1076 	default:
1077 		return NULL;
1078 	}
1079 }
1080 
1081 /* Register the PF specific function table.  */
1082 int sctp_register_pf(struct sctp_pf *pf, sa_family_t family)
1083 {
1084 	switch (family) {
1085 	case PF_INET:
1086 		if (sctp_pf_inet_specific)
1087 			return 0;
1088 		sctp_pf_inet_specific = pf;
1089 		break;
1090 	case PF_INET6:
1091 		if (sctp_pf_inet6_specific)
1092 			return 0;
1093 		sctp_pf_inet6_specific = pf;
1094 		break;
1095 	default:
1096 		return 0;
1097 	}
1098 	return 1;
1099 }
1100 
1101 static inline int init_sctp_mibs(struct net *net)
1102 {
1103 	return snmp_mib_init((void __percpu **)net->sctp.sctp_statistics,
1104 			     sizeof(struct sctp_mib),
1105 			     __alignof__(struct sctp_mib));
1106 }
1107 
1108 static inline void cleanup_sctp_mibs(struct net *net)
1109 {
1110 	snmp_mib_free((void __percpu **)net->sctp.sctp_statistics);
1111 }
1112 
1113 static void sctp_v4_pf_init(void)
1114 {
1115 	/* Initialize the SCTP specific PF functions. */
1116 	sctp_register_pf(&sctp_pf_inet, PF_INET);
1117 	sctp_register_af(&sctp_af_inet);
1118 }
1119 
1120 static void sctp_v4_pf_exit(void)
1121 {
1122 	list_del(&sctp_af_inet.list);
1123 }
1124 
1125 static int sctp_v4_protosw_init(void)
1126 {
1127 	int rc;
1128 
1129 	rc = proto_register(&sctp_prot, 1);
1130 	if (rc)
1131 		return rc;
1132 
1133 	/* Register SCTP(UDP and TCP style) with socket layer.  */
1134 	inet_register_protosw(&sctp_seqpacket_protosw);
1135 	inet_register_protosw(&sctp_stream_protosw);
1136 
1137 	return 0;
1138 }
1139 
1140 static void sctp_v4_protosw_exit(void)
1141 {
1142 	inet_unregister_protosw(&sctp_stream_protosw);
1143 	inet_unregister_protosw(&sctp_seqpacket_protosw);
1144 	proto_unregister(&sctp_prot);
1145 }
1146 
1147 static int sctp_v4_add_protocol(void)
1148 {
1149 	/* Register notifier for inet address additions/deletions. */
1150 	register_inetaddr_notifier(&sctp_inetaddr_notifier);
1151 
1152 	/* Register SCTP with inet layer.  */
1153 	if (inet_add_protocol(&sctp_protocol, IPPROTO_SCTP) < 0)
1154 		return -EAGAIN;
1155 
1156 	return 0;
1157 }
1158 
1159 static void sctp_v4_del_protocol(void)
1160 {
1161 	inet_del_protocol(&sctp_protocol, IPPROTO_SCTP);
1162 	unregister_inetaddr_notifier(&sctp_inetaddr_notifier);
1163 }
1164 
1165 static int __net_init sctp_net_init(struct net *net)
1166 {
1167 	int status;
1168 
1169 	/*
1170 	 * 14. Suggested SCTP Protocol Parameter Values
1171 	 */
1172 	/* The following protocol parameters are RECOMMENDED:  */
1173 	/* RTO.Initial              - 3  seconds */
1174 	net->sctp.rto_initial			= SCTP_RTO_INITIAL;
1175 	/* RTO.Min                  - 1  second */
1176 	net->sctp.rto_min	 		= SCTP_RTO_MIN;
1177 	/* RTO.Max                 -  60 seconds */
1178 	net->sctp.rto_max 			= SCTP_RTO_MAX;
1179 	/* RTO.Alpha                - 1/8 */
1180 	net->sctp.rto_alpha			= SCTP_RTO_ALPHA;
1181 	/* RTO.Beta                 - 1/4 */
1182 	net->sctp.rto_beta			= SCTP_RTO_BETA;
1183 
1184 	/* Valid.Cookie.Life        - 60  seconds */
1185 	net->sctp.valid_cookie_life		= SCTP_DEFAULT_COOKIE_LIFE;
1186 
1187 	/* Whether Cookie Preservative is enabled(1) or not(0) */
1188 	net->sctp.cookie_preserve_enable 	= 1;
1189 
1190 	/* Default sctp sockets to use md5 as their hmac alg */
1191 #if defined (CONFIG_SCTP_DEFAULT_COOKIE_HMAC_MD5)
1192 	net->sctp.sctp_hmac_alg			= "md5";
1193 #elif defined (CONFIG_SCTP_DEFAULT_COOKIE_HMAC_SHA1)
1194 	net->sctp.sctp_hmac_alg			= "sha1";
1195 #else
1196 	net->sctp.sctp_hmac_alg			= NULL;
1197 #endif
1198 
1199 	/* Max.Burst		    - 4 */
1200 	net->sctp.max_burst			= SCTP_DEFAULT_MAX_BURST;
1201 
1202 	/* Association.Max.Retrans  - 10 attempts
1203 	 * Path.Max.Retrans         - 5  attempts (per destination address)
1204 	 * Max.Init.Retransmits     - 8  attempts
1205 	 */
1206 	net->sctp.max_retrans_association	= 10;
1207 	net->sctp.max_retrans_path		= 5;
1208 	net->sctp.max_retrans_init		= 8;
1209 
1210 	/* Sendbuffer growth	    - do per-socket accounting */
1211 	net->sctp.sndbuf_policy			= 0;
1212 
1213 	/* Rcvbuffer growth	    - do per-socket accounting */
1214 	net->sctp.rcvbuf_policy			= 0;
1215 
1216 	/* HB.interval              - 30 seconds */
1217 	net->sctp.hb_interval			= SCTP_DEFAULT_TIMEOUT_HEARTBEAT;
1218 
1219 	/* delayed SACK timeout */
1220 	net->sctp.sack_timeout			= SCTP_DEFAULT_TIMEOUT_SACK;
1221 
1222 	/* Disable ADDIP by default. */
1223 	net->sctp.addip_enable = 0;
1224 	net->sctp.addip_noauth = 0;
1225 	net->sctp.default_auto_asconf = 0;
1226 
1227 	/* Enable PR-SCTP by default. */
1228 	net->sctp.prsctp_enable = 1;
1229 
1230 	/* Disable AUTH by default. */
1231 	net->sctp.auth_enable = 0;
1232 
1233 	/* Set SCOPE policy to enabled */
1234 	net->sctp.scope_policy = SCTP_SCOPE_POLICY_ENABLE;
1235 
1236 	/* Set the default rwnd update threshold */
1237 	net->sctp.rwnd_upd_shift = SCTP_DEFAULT_RWND_SHIFT;
1238 
1239 	/* Initialize maximum autoclose timeout. */
1240 	net->sctp.max_autoclose		= INT_MAX / HZ;
1241 
1242 	status = sctp_sysctl_net_register(net);
1243 	if (status)
1244 		goto err_sysctl_register;
1245 
1246 	/* Allocate and initialise sctp mibs.  */
1247 	status = init_sctp_mibs(net);
1248 	if (status)
1249 		goto err_init_mibs;
1250 
1251 	/* Initialize proc fs directory.  */
1252 	status = sctp_proc_init(net);
1253 	if (status)
1254 		goto err_init_proc;
1255 
1256 	sctp_dbg_objcnt_init(net);
1257 
1258 	/* Initialize the control inode/socket for handling OOTB packets.  */
1259 	if ((status = sctp_ctl_sock_init(net))) {
1260 		pr_err("Failed to initialize the SCTP control sock\n");
1261 		goto err_ctl_sock_init;
1262 	}
1263 
1264 	/* Initialize the local address list. */
1265 	INIT_LIST_HEAD(&net->sctp.local_addr_list);
1266 	spin_lock_init(&net->sctp.local_addr_lock);
1267 	sctp_get_local_addr_list(net);
1268 
1269 	/* Initialize the address event list */
1270 	INIT_LIST_HEAD(&net->sctp.addr_waitq);
1271 	INIT_LIST_HEAD(&net->sctp.auto_asconf_splist);
1272 	spin_lock_init(&net->sctp.addr_wq_lock);
1273 	net->sctp.addr_wq_timer.expires = 0;
1274 	setup_timer(&net->sctp.addr_wq_timer, sctp_addr_wq_timeout_handler,
1275 		    (unsigned long)net);
1276 
1277 	return 0;
1278 
1279 err_ctl_sock_init:
1280 	sctp_dbg_objcnt_exit(net);
1281 	sctp_proc_exit(net);
1282 err_init_proc:
1283 	cleanup_sctp_mibs(net);
1284 err_init_mibs:
1285 	sctp_sysctl_net_unregister(net);
1286 err_sysctl_register:
1287 	return status;
1288 }
1289 
1290 static void __net_exit sctp_net_exit(struct net *net)
1291 {
1292 	/* Free the local address list */
1293 	sctp_free_addr_wq(net);
1294 	sctp_free_local_addr_list(net);
1295 
1296 	/* Free the control endpoint.  */
1297 	inet_ctl_sock_destroy(net->sctp.ctl_sock);
1298 
1299 	sctp_dbg_objcnt_exit(net);
1300 
1301 	sctp_proc_exit(net);
1302 	cleanup_sctp_mibs(net);
1303 	sctp_sysctl_net_unregister(net);
1304 }
1305 
1306 static struct pernet_operations sctp_net_ops = {
1307 	.init = sctp_net_init,
1308 	.exit = sctp_net_exit,
1309 };
1310 
1311 /* Initialize the universe into something sensible.  */
1312 static __init int sctp_init(void)
1313 {
1314 	int i;
1315 	int status = -EINVAL;
1316 	unsigned long goal;
1317 	unsigned long limit;
1318 	int max_share;
1319 	int order;
1320 
1321 	BUILD_BUG_ON(sizeof(struct sctp_ulpevent) >
1322 		     sizeof(((struct sk_buff *) 0)->cb));
1323 
1324 	/* Allocate bind_bucket and chunk caches. */
1325 	status = -ENOBUFS;
1326 	sctp_bucket_cachep = kmem_cache_create("sctp_bind_bucket",
1327 					       sizeof(struct sctp_bind_bucket),
1328 					       0, SLAB_HWCACHE_ALIGN,
1329 					       NULL);
1330 	if (!sctp_bucket_cachep)
1331 		goto out;
1332 
1333 	sctp_chunk_cachep = kmem_cache_create("sctp_chunk",
1334 					       sizeof(struct sctp_chunk),
1335 					       0, SLAB_HWCACHE_ALIGN,
1336 					       NULL);
1337 	if (!sctp_chunk_cachep)
1338 		goto err_chunk_cachep;
1339 
1340 	status = percpu_counter_init(&sctp_sockets_allocated, 0);
1341 	if (status)
1342 		goto err_percpu_counter_init;
1343 
1344 	/* Implementation specific variables. */
1345 
1346 	/* Initialize default stream count setup information. */
1347 	sctp_max_instreams    		= SCTP_DEFAULT_INSTREAMS;
1348 	sctp_max_outstreams   		= SCTP_DEFAULT_OUTSTREAMS;
1349 
1350 	/* Initialize handle used for association ids. */
1351 	idr_init(&sctp_assocs_id);
1352 
1353 	limit = nr_free_buffer_pages() / 8;
1354 	limit = max(limit, 128UL);
1355 	sysctl_sctp_mem[0] = limit / 4 * 3;
1356 	sysctl_sctp_mem[1] = limit;
1357 	sysctl_sctp_mem[2] = sysctl_sctp_mem[0] * 2;
1358 
1359 	/* Set per-socket limits to no more than 1/128 the pressure threshold*/
1360 	limit = (sysctl_sctp_mem[1]) << (PAGE_SHIFT - 7);
1361 	max_share = min(4UL*1024*1024, limit);
1362 
1363 	sysctl_sctp_rmem[0] = SK_MEM_QUANTUM; /* give each asoc 1 page min */
1364 	sysctl_sctp_rmem[1] = 1500 * SKB_TRUESIZE(1);
1365 	sysctl_sctp_rmem[2] = max(sysctl_sctp_rmem[1], max_share);
1366 
1367 	sysctl_sctp_wmem[0] = SK_MEM_QUANTUM;
1368 	sysctl_sctp_wmem[1] = 16*1024;
1369 	sysctl_sctp_wmem[2] = max(64*1024, max_share);
1370 
1371 	/* Size and allocate the association hash table.
1372 	 * The methodology is similar to that of the tcp hash tables.
1373 	 */
1374 	if (totalram_pages >= (128 * 1024))
1375 		goal = totalram_pages >> (22 - PAGE_SHIFT);
1376 	else
1377 		goal = totalram_pages >> (24 - PAGE_SHIFT);
1378 
1379 	for (order = 0; (1UL << order) < goal; order++)
1380 		;
1381 
1382 	do {
1383 		sctp_assoc_hashsize = (1UL << order) * PAGE_SIZE /
1384 					sizeof(struct sctp_hashbucket);
1385 		if ((sctp_assoc_hashsize > (64 * 1024)) && order > 0)
1386 			continue;
1387 		sctp_assoc_hashtable = (struct sctp_hashbucket *)
1388 			__get_free_pages(GFP_ATOMIC|__GFP_NOWARN, order);
1389 	} while (!sctp_assoc_hashtable && --order > 0);
1390 	if (!sctp_assoc_hashtable) {
1391 		pr_err("Failed association hash alloc\n");
1392 		status = -ENOMEM;
1393 		goto err_ahash_alloc;
1394 	}
1395 	for (i = 0; i < sctp_assoc_hashsize; i++) {
1396 		rwlock_init(&sctp_assoc_hashtable[i].lock);
1397 		INIT_HLIST_HEAD(&sctp_assoc_hashtable[i].chain);
1398 	}
1399 
1400 	/* Allocate and initialize the endpoint hash table.  */
1401 	sctp_ep_hashsize = 64;
1402 	sctp_ep_hashtable =
1403 		kmalloc(64 * sizeof(struct sctp_hashbucket), GFP_KERNEL);
1404 	if (!sctp_ep_hashtable) {
1405 		pr_err("Failed endpoint_hash alloc\n");
1406 		status = -ENOMEM;
1407 		goto err_ehash_alloc;
1408 	}
1409 	for (i = 0; i < sctp_ep_hashsize; i++) {
1410 		rwlock_init(&sctp_ep_hashtable[i].lock);
1411 		INIT_HLIST_HEAD(&sctp_ep_hashtable[i].chain);
1412 	}
1413 
1414 	/* Allocate and initialize the SCTP port hash table.  */
1415 	do {
1416 		sctp_port_hashsize = (1UL << order) * PAGE_SIZE /
1417 					sizeof(struct sctp_bind_hashbucket);
1418 		if ((sctp_port_hashsize > (64 * 1024)) && order > 0)
1419 			continue;
1420 		sctp_port_hashtable = (struct sctp_bind_hashbucket *)
1421 			__get_free_pages(GFP_ATOMIC|__GFP_NOWARN, order);
1422 	} while (!sctp_port_hashtable && --order > 0);
1423 	if (!sctp_port_hashtable) {
1424 		pr_err("Failed bind hash alloc\n");
1425 		status = -ENOMEM;
1426 		goto err_bhash_alloc;
1427 	}
1428 	for (i = 0; i < sctp_port_hashsize; i++) {
1429 		spin_lock_init(&sctp_port_hashtable[i].lock);
1430 		INIT_HLIST_HEAD(&sctp_port_hashtable[i].chain);
1431 	}
1432 
1433 	pr_info("Hash tables configured (established %d bind %d)\n",
1434 		sctp_assoc_hashsize, sctp_port_hashsize);
1435 
1436 	sctp_sysctl_register();
1437 
1438 	INIT_LIST_HEAD(&sctp_address_families);
1439 	sctp_v4_pf_init();
1440 	sctp_v6_pf_init();
1441 
1442 	status = sctp_v4_protosw_init();
1443 
1444 	if (status)
1445 		goto err_protosw_init;
1446 
1447 	status = sctp_v6_protosw_init();
1448 	if (status)
1449 		goto err_v6_protosw_init;
1450 
1451 	status = register_pernet_subsys(&sctp_net_ops);
1452 	if (status)
1453 		goto err_register_pernet_subsys;
1454 
1455 	status = sctp_v4_add_protocol();
1456 	if (status)
1457 		goto err_add_protocol;
1458 
1459 	/* Register SCTP with inet6 layer.  */
1460 	status = sctp_v6_add_protocol();
1461 	if (status)
1462 		goto err_v6_add_protocol;
1463 
1464 out:
1465 	return status;
1466 err_v6_add_protocol:
1467 	sctp_v4_del_protocol();
1468 err_add_protocol:
1469 	unregister_pernet_subsys(&sctp_net_ops);
1470 err_register_pernet_subsys:
1471 	sctp_v6_protosw_exit();
1472 err_v6_protosw_init:
1473 	sctp_v4_protosw_exit();
1474 err_protosw_init:
1475 	sctp_v4_pf_exit();
1476 	sctp_v6_pf_exit();
1477 	sctp_sysctl_unregister();
1478 	free_pages((unsigned long)sctp_port_hashtable,
1479 		   get_order(sctp_port_hashsize *
1480 			     sizeof(struct sctp_bind_hashbucket)));
1481 err_bhash_alloc:
1482 	kfree(sctp_ep_hashtable);
1483 err_ehash_alloc:
1484 	free_pages((unsigned long)sctp_assoc_hashtable,
1485 		   get_order(sctp_assoc_hashsize *
1486 			     sizeof(struct sctp_hashbucket)));
1487 err_ahash_alloc:
1488 	percpu_counter_destroy(&sctp_sockets_allocated);
1489 err_percpu_counter_init:
1490 	kmem_cache_destroy(sctp_chunk_cachep);
1491 err_chunk_cachep:
1492 	kmem_cache_destroy(sctp_bucket_cachep);
1493 	goto out;
1494 }
1495 
1496 /* Exit handler for the SCTP protocol.  */
1497 static __exit void sctp_exit(void)
1498 {
1499 	/* BUG.  This should probably do something useful like clean
1500 	 * up all the remaining associations and all that memory.
1501 	 */
1502 
1503 	/* Unregister with inet6/inet layers. */
1504 	sctp_v6_del_protocol();
1505 	sctp_v4_del_protocol();
1506 
1507 	unregister_pernet_subsys(&sctp_net_ops);
1508 
1509 	/* Free protosw registrations */
1510 	sctp_v6_protosw_exit();
1511 	sctp_v4_protosw_exit();
1512 
1513 	/* Unregister with socket layer. */
1514 	sctp_v6_pf_exit();
1515 	sctp_v4_pf_exit();
1516 
1517 	sctp_sysctl_unregister();
1518 
1519 	free_pages((unsigned long)sctp_assoc_hashtable,
1520 		   get_order(sctp_assoc_hashsize *
1521 			     sizeof(struct sctp_hashbucket)));
1522 	kfree(sctp_ep_hashtable);
1523 	free_pages((unsigned long)sctp_port_hashtable,
1524 		   get_order(sctp_port_hashsize *
1525 			     sizeof(struct sctp_bind_hashbucket)));
1526 
1527 	percpu_counter_destroy(&sctp_sockets_allocated);
1528 
1529 	rcu_barrier(); /* Wait for completion of call_rcu()'s */
1530 
1531 	kmem_cache_destroy(sctp_chunk_cachep);
1532 	kmem_cache_destroy(sctp_bucket_cachep);
1533 }
1534 
1535 module_init(sctp_init);
1536 module_exit(sctp_exit);
1537 
1538 /*
1539  * __stringify doesn't likes enums, so use IPPROTO_SCTP value (132) directly.
1540  */
1541 MODULE_ALIAS("net-pf-" __stringify(PF_INET) "-proto-132");
1542 MODULE_ALIAS("net-pf-" __stringify(PF_INET6) "-proto-132");
1543 MODULE_AUTHOR("Linux Kernel SCTP developers <linux-sctp@vger.kernel.org>");
1544 MODULE_DESCRIPTION("Support for the SCTP protocol (RFC2960)");
1545 module_param_named(no_checksums, sctp_checksum_disable, bool, 0644);
1546 MODULE_PARM_DESC(no_checksums, "Disable checksums computing and verification");
1547 MODULE_LICENSE("GPL");
1548