xref: /openbmc/linux/net/sctp/protocol.c (revision f7777dcc)
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, write to
27  * the Free Software Foundation, 59 Temple Place - Suite 330,
28  * Boston, MA 02111-1307, USA.
29  *
30  * Please send any bug reports or fixes you make to the
31  * email address(es):
32  *    lksctp developers <linux-sctp@vger.kernel.org>
33  *
34  * Written or modified by:
35  *    La Monte H.P. Yarroll <piggy@acm.org>
36  *    Karl Knutson <karl@athena.chicago.il.us>
37  *    Jon Grimm <jgrimm@us.ibm.com>
38  *    Sridhar Samudrala <sri@us.ibm.com>
39  *    Daisy Chang <daisyc@us.ibm.com>
40  *    Ardelle Fan <ardelle.fan@intel.com>
41  */
42 
43 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
44 
45 #include <linux/module.h>
46 #include <linux/init.h>
47 #include <linux/netdevice.h>
48 #include <linux/inetdevice.h>
49 #include <linux/seq_file.h>
50 #include <linux/bootmem.h>
51 #include <linux/highmem.h>
52 #include <linux/swap.h>
53 #include <linux/slab.h>
54 #include <net/net_namespace.h>
55 #include <net/protocol.h>
56 #include <net/ip.h>
57 #include <net/ipv6.h>
58 #include <net/route.h>
59 #include <net/sctp/sctp.h>
60 #include <net/addrconf.h>
61 #include <net/inet_common.h>
62 #include <net/inet_ecn.h>
63 
64 /* Global data structures. */
65 struct sctp_globals sctp_globals __read_mostly;
66 
67 struct idr sctp_assocs_id;
68 DEFINE_SPINLOCK(sctp_assocs_id_lock);
69 
70 static struct sctp_pf *sctp_pf_inet6_specific;
71 static struct sctp_pf *sctp_pf_inet_specific;
72 static struct sctp_af *sctp_af_v4_specific;
73 static struct sctp_af *sctp_af_v6_specific;
74 
75 struct kmem_cache *sctp_chunk_cachep __read_mostly;
76 struct kmem_cache *sctp_bucket_cachep __read_mostly;
77 
78 long sysctl_sctp_mem[3];
79 int sysctl_sctp_rmem[3];
80 int sysctl_sctp_wmem[3];
81 
82 /* Set up the proc fs entry for the SCTP protocol. */
83 static int __net_init sctp_proc_init(struct net *net)
84 {
85 #ifdef CONFIG_PROC_FS
86 	net->sctp.proc_net_sctp = proc_net_mkdir(net, "sctp", net->proc_net);
87 	if (!net->sctp.proc_net_sctp)
88 		goto out_proc_net_sctp;
89 	if (sctp_snmp_proc_init(net))
90 		goto out_snmp_proc_init;
91 	if (sctp_eps_proc_init(net))
92 		goto out_eps_proc_init;
93 	if (sctp_assocs_proc_init(net))
94 		goto out_assocs_proc_init;
95 	if (sctp_remaddr_proc_init(net))
96 		goto out_remaddr_proc_init;
97 
98 	return 0;
99 
100 out_remaddr_proc_init:
101 	sctp_assocs_proc_exit(net);
102 out_assocs_proc_init:
103 	sctp_eps_proc_exit(net);
104 out_eps_proc_init:
105 	sctp_snmp_proc_exit(net);
106 out_snmp_proc_init:
107 	remove_proc_entry("sctp", net->proc_net);
108 	net->sctp.proc_net_sctp = NULL;
109 out_proc_net_sctp:
110 	return -ENOMEM;
111 #endif /* CONFIG_PROC_FS */
112 	return 0;
113 }
114 
115 /* Clean up the proc fs entry for the SCTP protocol.
116  * Note: Do not make this __exit as it is used in the init error
117  * path.
118  */
119 static void sctp_proc_exit(struct net *net)
120 {
121 #ifdef CONFIG_PROC_FS
122 	sctp_snmp_proc_exit(net);
123 	sctp_eps_proc_exit(net);
124 	sctp_assocs_proc_exit(net);
125 	sctp_remaddr_proc_exit(net);
126 
127 	remove_proc_entry("sctp", net->proc_net);
128 	net->sctp.proc_net_sctp = NULL;
129 #endif
130 }
131 
132 /* Private helper to extract ipv4 address and stash them in
133  * the protocol structure.
134  */
135 static void sctp_v4_copy_addrlist(struct list_head *addrlist,
136 				  struct net_device *dev)
137 {
138 	struct in_device *in_dev;
139 	struct in_ifaddr *ifa;
140 	struct sctp_sockaddr_entry *addr;
141 
142 	rcu_read_lock();
143 	if ((in_dev = __in_dev_get_rcu(dev)) == NULL) {
144 		rcu_read_unlock();
145 		return;
146 	}
147 
148 	for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) {
149 		/* Add the address to the local list.  */
150 		addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
151 		if (addr) {
152 			addr->a.v4.sin_family = AF_INET;
153 			addr->a.v4.sin_port = 0;
154 			addr->a.v4.sin_addr.s_addr = ifa->ifa_local;
155 			addr->valid = 1;
156 			INIT_LIST_HEAD(&addr->list);
157 			list_add_tail(&addr->list, addrlist);
158 		}
159 	}
160 
161 	rcu_read_unlock();
162 }
163 
164 /* Extract our IP addresses from the system and stash them in the
165  * protocol structure.
166  */
167 static void sctp_get_local_addr_list(struct net *net)
168 {
169 	struct net_device *dev;
170 	struct list_head *pos;
171 	struct sctp_af *af;
172 
173 	rcu_read_lock();
174 	for_each_netdev_rcu(net, dev) {
175 		list_for_each(pos, &sctp_address_families) {
176 			af = list_entry(pos, struct sctp_af, list);
177 			af->copy_addrlist(&net->sctp.local_addr_list, dev);
178 		}
179 	}
180 	rcu_read_unlock();
181 }
182 
183 /* Free the existing local addresses.  */
184 static void sctp_free_local_addr_list(struct net *net)
185 {
186 	struct sctp_sockaddr_entry *addr;
187 	struct list_head *pos, *temp;
188 
189 	list_for_each_safe(pos, temp, &net->sctp.local_addr_list) {
190 		addr = list_entry(pos, struct sctp_sockaddr_entry, list);
191 		list_del(pos);
192 		kfree(addr);
193 	}
194 }
195 
196 /* Copy the local addresses which are valid for 'scope' into 'bp'.  */
197 int sctp_copy_local_addr_list(struct net *net, struct sctp_bind_addr *bp,
198 			      sctp_scope_t scope, gfp_t gfp, int copy_flags)
199 {
200 	struct sctp_sockaddr_entry *addr;
201 	int error = 0;
202 
203 	rcu_read_lock();
204 	list_for_each_entry_rcu(addr, &net->sctp.local_addr_list, list) {
205 		if (!addr->valid)
206 			continue;
207 		if (sctp_in_scope(net, &addr->a, scope)) {
208 			/* Now that the address is in scope, check to see if
209 			 * the address type is really supported by the local
210 			 * sock as well as the remote peer.
211 			 */
212 			if ((((AF_INET == addr->a.sa.sa_family) &&
213 			      (copy_flags & SCTP_ADDR4_PEERSUPP))) ||
214 			    (((AF_INET6 == addr->a.sa.sa_family) &&
215 			      (copy_flags & SCTP_ADDR6_ALLOWED) &&
216 			      (copy_flags & SCTP_ADDR6_PEERSUPP)))) {
217 				error = sctp_add_bind_addr(bp, &addr->a,
218 						    SCTP_ADDR_SRC, GFP_ATOMIC);
219 				if (error)
220 					goto end_copy;
221 			}
222 		}
223 	}
224 
225 end_copy:
226 	rcu_read_unlock();
227 	return error;
228 }
229 
230 /* Initialize a sctp_addr from in incoming skb.  */
231 static void sctp_v4_from_skb(union sctp_addr *addr, struct sk_buff *skb,
232 			     int is_saddr)
233 {
234 	void *from;
235 	__be16 *port;
236 	struct sctphdr *sh;
237 
238 	port = &addr->v4.sin_port;
239 	addr->v4.sin_family = AF_INET;
240 
241 	sh = sctp_hdr(skb);
242 	if (is_saddr) {
243 		*port  = sh->source;
244 		from = &ip_hdr(skb)->saddr;
245 	} else {
246 		*port = sh->dest;
247 		from = &ip_hdr(skb)->daddr;
248 	}
249 	memcpy(&addr->v4.sin_addr.s_addr, from, sizeof(struct in_addr));
250 }
251 
252 /* Initialize an sctp_addr from a socket. */
253 static void sctp_v4_from_sk(union sctp_addr *addr, struct sock *sk)
254 {
255 	addr->v4.sin_family = AF_INET;
256 	addr->v4.sin_port = 0;
257 	addr->v4.sin_addr.s_addr = inet_sk(sk)->inet_rcv_saddr;
258 }
259 
260 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
261 static void sctp_v4_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
262 {
263 	inet_sk(sk)->inet_rcv_saddr = addr->v4.sin_addr.s_addr;
264 }
265 
266 /* Initialize sk->sk_daddr from sctp_addr. */
267 static void sctp_v4_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
268 {
269 	inet_sk(sk)->inet_daddr = addr->v4.sin_addr.s_addr;
270 }
271 
272 /* Initialize a sctp_addr from an address parameter. */
273 static void sctp_v4_from_addr_param(union sctp_addr *addr,
274 				    union sctp_addr_param *param,
275 				    __be16 port, int iif)
276 {
277 	addr->v4.sin_family = AF_INET;
278 	addr->v4.sin_port = port;
279 	addr->v4.sin_addr.s_addr = param->v4.addr.s_addr;
280 }
281 
282 /* Initialize an address parameter from a sctp_addr and return the length
283  * of the address parameter.
284  */
285 static int sctp_v4_to_addr_param(const union sctp_addr *addr,
286 				 union sctp_addr_param *param)
287 {
288 	int length = sizeof(sctp_ipv4addr_param_t);
289 
290 	param->v4.param_hdr.type = SCTP_PARAM_IPV4_ADDRESS;
291 	param->v4.param_hdr.length = htons(length);
292 	param->v4.addr.s_addr = addr->v4.sin_addr.s_addr;
293 
294 	return length;
295 }
296 
297 /* Initialize a sctp_addr from a dst_entry. */
298 static void sctp_v4_dst_saddr(union sctp_addr *saddr, struct flowi4 *fl4,
299 			      __be16 port)
300 {
301 	saddr->v4.sin_family = AF_INET;
302 	saddr->v4.sin_port = port;
303 	saddr->v4.sin_addr.s_addr = fl4->saddr;
304 }
305 
306 /* Compare two addresses exactly. */
307 static int sctp_v4_cmp_addr(const union sctp_addr *addr1,
308 			    const union sctp_addr *addr2)
309 {
310 	if (addr1->sa.sa_family != addr2->sa.sa_family)
311 		return 0;
312 	if (addr1->v4.sin_port != addr2->v4.sin_port)
313 		return 0;
314 	if (addr1->v4.sin_addr.s_addr != addr2->v4.sin_addr.s_addr)
315 		return 0;
316 
317 	return 1;
318 }
319 
320 /* Initialize addr struct to INADDR_ANY. */
321 static void sctp_v4_inaddr_any(union sctp_addr *addr, __be16 port)
322 {
323 	addr->v4.sin_family = AF_INET;
324 	addr->v4.sin_addr.s_addr = htonl(INADDR_ANY);
325 	addr->v4.sin_port = port;
326 }
327 
328 /* Is this a wildcard address? */
329 static int sctp_v4_is_any(const union sctp_addr *addr)
330 {
331 	return htonl(INADDR_ANY) == addr->v4.sin_addr.s_addr;
332 }
333 
334 /* This function checks if the address is a valid address to be used for
335  * SCTP binding.
336  *
337  * Output:
338  * Return 0 - If the address is a non-unicast or an illegal address.
339  * Return 1 - If the address is a unicast.
340  */
341 static int sctp_v4_addr_valid(union sctp_addr *addr,
342 			      struct sctp_sock *sp,
343 			      const struct sk_buff *skb)
344 {
345 	/* IPv4 addresses not allowed */
346 	if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
347 		return 0;
348 
349 	/* Is this a non-unicast address or a unusable SCTP address? */
350 	if (IS_IPV4_UNUSABLE_ADDRESS(addr->v4.sin_addr.s_addr))
351 		return 0;
352 
353 	/* Is this a broadcast address? */
354 	if (skb && skb_rtable(skb)->rt_flags & RTCF_BROADCAST)
355 		return 0;
356 
357 	return 1;
358 }
359 
360 /* Should this be available for binding?   */
361 static int sctp_v4_available(union sctp_addr *addr, struct sctp_sock *sp)
362 {
363 	struct net *net = sock_net(&sp->inet.sk);
364 	int ret = inet_addr_type(net, addr->v4.sin_addr.s_addr);
365 
366 
367 	if (addr->v4.sin_addr.s_addr != htonl(INADDR_ANY) &&
368 	   ret != RTN_LOCAL &&
369 	   !sp->inet.freebind &&
370 	   !sysctl_ip_nonlocal_bind)
371 		return 0;
372 
373 	if (ipv6_only_sock(sctp_opt2sk(sp)))
374 		return 0;
375 
376 	return 1;
377 }
378 
379 /* Checking the loopback, private and other address scopes as defined in
380  * RFC 1918.   The IPv4 scoping is based on the draft for SCTP IPv4
381  * scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>.
382  *
383  * Level 0 - unusable SCTP addresses
384  * Level 1 - loopback address
385  * Level 2 - link-local addresses
386  * Level 3 - private addresses.
387  * Level 4 - global addresses
388  * For INIT and INIT-ACK address list, let L be the level of
389  * of requested destination address, sender and receiver
390  * SHOULD include all of its addresses with level greater
391  * than or equal to L.
392  *
393  * IPv4 scoping can be controlled through sysctl option
394  * net.sctp.addr_scope_policy
395  */
396 static sctp_scope_t sctp_v4_scope(union sctp_addr *addr)
397 {
398 	sctp_scope_t retval;
399 
400 	/* Check for unusable SCTP addresses. */
401 	if (IS_IPV4_UNUSABLE_ADDRESS(addr->v4.sin_addr.s_addr)) {
402 		retval =  SCTP_SCOPE_UNUSABLE;
403 	} else if (ipv4_is_loopback(addr->v4.sin_addr.s_addr)) {
404 		retval = SCTP_SCOPE_LOOPBACK;
405 	} else if (ipv4_is_linklocal_169(addr->v4.sin_addr.s_addr)) {
406 		retval = SCTP_SCOPE_LINK;
407 	} else if (ipv4_is_private_10(addr->v4.sin_addr.s_addr) ||
408 		   ipv4_is_private_172(addr->v4.sin_addr.s_addr) ||
409 		   ipv4_is_private_192(addr->v4.sin_addr.s_addr)) {
410 		retval = SCTP_SCOPE_PRIVATE;
411 	} else {
412 		retval = SCTP_SCOPE_GLOBAL;
413 	}
414 
415 	return retval;
416 }
417 
418 /* Returns a valid dst cache entry for the given source and destination ip
419  * addresses. If an association is passed, trys to get a dst entry with a
420  * source address that matches an address in the bind address list.
421  */
422 static void sctp_v4_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
423 				struct flowi *fl, struct sock *sk)
424 {
425 	struct sctp_association *asoc = t->asoc;
426 	struct rtable *rt;
427 	struct flowi4 *fl4 = &fl->u.ip4;
428 	struct sctp_bind_addr *bp;
429 	struct sctp_sockaddr_entry *laddr;
430 	struct dst_entry *dst = NULL;
431 	union sctp_addr *daddr = &t->ipaddr;
432 	union sctp_addr dst_saddr;
433 
434 	memset(fl4, 0x0, sizeof(struct flowi4));
435 	fl4->daddr  = daddr->v4.sin_addr.s_addr;
436 	fl4->fl4_dport = daddr->v4.sin_port;
437 	fl4->flowi4_proto = IPPROTO_SCTP;
438 	if (asoc) {
439 		fl4->flowi4_tos = RT_CONN_FLAGS(asoc->base.sk);
440 		fl4->flowi4_oif = asoc->base.sk->sk_bound_dev_if;
441 		fl4->fl4_sport = htons(asoc->base.bind_addr.port);
442 	}
443 	if (saddr) {
444 		fl4->saddr = saddr->v4.sin_addr.s_addr;
445 		fl4->fl4_sport = saddr->v4.sin_port;
446 	}
447 
448 	pr_debug("%s: dst:%pI4, src:%pI4 - ", __func__, &fl4->daddr,
449 		 &fl4->saddr);
450 
451 	rt = ip_route_output_key(sock_net(sk), fl4);
452 	if (!IS_ERR(rt))
453 		dst = &rt->dst;
454 
455 	/* If there is no association or if a source address is passed, no
456 	 * more validation is required.
457 	 */
458 	if (!asoc || saddr)
459 		goto out;
460 
461 	bp = &asoc->base.bind_addr;
462 
463 	if (dst) {
464 		/* Walk through the bind address list and look for a bind
465 		 * address that matches the source address of the returned dst.
466 		 */
467 		sctp_v4_dst_saddr(&dst_saddr, fl4, htons(bp->port));
468 		rcu_read_lock();
469 		list_for_each_entry_rcu(laddr, &bp->address_list, list) {
470 			if (!laddr->valid || (laddr->state == SCTP_ADDR_DEL) ||
471 			    (laddr->state != SCTP_ADDR_SRC &&
472 			    !asoc->src_out_of_asoc_ok))
473 				continue;
474 			if (sctp_v4_cmp_addr(&dst_saddr, &laddr->a))
475 				goto out_unlock;
476 		}
477 		rcu_read_unlock();
478 
479 		/* None of the bound addresses match the source address of the
480 		 * dst. So release it.
481 		 */
482 		dst_release(dst);
483 		dst = NULL;
484 	}
485 
486 	/* Walk through the bind address list and try to get a dst that
487 	 * matches a bind address as the source address.
488 	 */
489 	rcu_read_lock();
490 	list_for_each_entry_rcu(laddr, &bp->address_list, list) {
491 		if (!laddr->valid)
492 			continue;
493 		if ((laddr->state == SCTP_ADDR_SRC) &&
494 		    (AF_INET == laddr->a.sa.sa_family)) {
495 			fl4->saddr = laddr->a.v4.sin_addr.s_addr;
496 			fl4->fl4_sport = laddr->a.v4.sin_port;
497 			rt = ip_route_output_key(sock_net(sk), fl4);
498 			if (!IS_ERR(rt)) {
499 				dst = &rt->dst;
500 				goto out_unlock;
501 			}
502 		}
503 	}
504 
505 out_unlock:
506 	rcu_read_unlock();
507 out:
508 	t->dst = dst;
509 	if (dst)
510 		pr_debug("rt_dst:%pI4, rt_src:%pI4\n",
511 			 &fl4->daddr, &fl4->saddr);
512 	else
513 		pr_debug("no route\n");
514 }
515 
516 /* For v4, the source address is cached in the route entry(dst). So no need
517  * to cache it separately and hence this is an empty routine.
518  */
519 static void sctp_v4_get_saddr(struct sctp_sock *sk,
520 			      struct sctp_transport *t,
521 			      struct flowi *fl)
522 {
523 	union sctp_addr *saddr = &t->saddr;
524 	struct rtable *rt = (struct rtable *)t->dst;
525 
526 	if (rt) {
527 		saddr->v4.sin_family = AF_INET;
528 		saddr->v4.sin_addr.s_addr = fl->u.ip4.saddr;
529 	}
530 }
531 
532 /* What interface did this skb arrive on? */
533 static int sctp_v4_skb_iif(const struct sk_buff *skb)
534 {
535 	return inet_iif(skb);
536 }
537 
538 /* Was this packet marked by Explicit Congestion Notification? */
539 static int sctp_v4_is_ce(const struct sk_buff *skb)
540 {
541 	return INET_ECN_is_ce(ip_hdr(skb)->tos);
542 }
543 
544 /* Create and initialize a new sk for the socket returned by accept(). */
545 static struct sock *sctp_v4_create_accept_sk(struct sock *sk,
546 					     struct sctp_association *asoc)
547 {
548 	struct sock *newsk = sk_alloc(sock_net(sk), PF_INET, GFP_KERNEL,
549 			sk->sk_prot);
550 	struct inet_sock *newinet;
551 
552 	if (!newsk)
553 		goto out;
554 
555 	sock_init_data(NULL, newsk);
556 
557 	sctp_copy_sock(newsk, sk, asoc);
558 	sock_reset_flag(newsk, SOCK_ZAPPED);
559 
560 	newinet = inet_sk(newsk);
561 
562 	newinet->inet_daddr = asoc->peer.primary_addr.v4.sin_addr.s_addr;
563 
564 	sk_refcnt_debug_inc(newsk);
565 
566 	if (newsk->sk_prot->init(newsk)) {
567 		sk_common_release(newsk);
568 		newsk = NULL;
569 	}
570 
571 out:
572 	return newsk;
573 }
574 
575 /* Map address, empty for v4 family */
576 static void sctp_v4_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
577 {
578 	/* Empty */
579 }
580 
581 /* Dump the v4 addr to the seq file. */
582 static void sctp_v4_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
583 {
584 	seq_printf(seq, "%pI4 ", &addr->v4.sin_addr);
585 }
586 
587 static void sctp_v4_ecn_capable(struct sock *sk)
588 {
589 	INET_ECN_xmit(sk);
590 }
591 
592 static void sctp_addr_wq_timeout_handler(unsigned long arg)
593 {
594 	struct net *net = (struct net *)arg;
595 	struct sctp_sockaddr_entry *addrw, *temp;
596 	struct sctp_sock *sp;
597 
598 	spin_lock_bh(&net->sctp.addr_wq_lock);
599 
600 	list_for_each_entry_safe(addrw, temp, &net->sctp.addr_waitq, list) {
601 		pr_debug("%s: the first ent in wq:%p is addr:%pISc for cmd:%d at "
602 			 "entry:%p\n", __func__, &net->sctp.addr_waitq, &addrw->a.sa,
603 			 addrw->state, addrw);
604 
605 #if IS_ENABLED(CONFIG_IPV6)
606 		/* Now we send an ASCONF for each association */
607 		/* Note. we currently don't handle link local IPv6 addressees */
608 		if (addrw->a.sa.sa_family == AF_INET6) {
609 			struct in6_addr *in6;
610 
611 			if (ipv6_addr_type(&addrw->a.v6.sin6_addr) &
612 			    IPV6_ADDR_LINKLOCAL)
613 				goto free_next;
614 
615 			in6 = (struct in6_addr *)&addrw->a.v6.sin6_addr;
616 			if (ipv6_chk_addr(net, in6, NULL, 0) == 0 &&
617 			    addrw->state == SCTP_ADDR_NEW) {
618 				unsigned long timeo_val;
619 
620 				pr_debug("%s: this is on DAD, trying %d sec "
621 					 "later\n", __func__,
622 					 SCTP_ADDRESS_TICK_DELAY);
623 
624 				timeo_val = jiffies;
625 				timeo_val += msecs_to_jiffies(SCTP_ADDRESS_TICK_DELAY);
626 				mod_timer(&net->sctp.addr_wq_timer, timeo_val);
627 				break;
628 			}
629 		}
630 #endif
631 		list_for_each_entry(sp, &net->sctp.auto_asconf_splist, auto_asconf_list) {
632 			struct sock *sk;
633 
634 			sk = sctp_opt2sk(sp);
635 			/* ignore bound-specific endpoints */
636 			if (!sctp_is_ep_boundall(sk))
637 				continue;
638 			sctp_bh_lock_sock(sk);
639 			if (sctp_asconf_mgmt(sp, addrw) < 0)
640 				pr_debug("%s: sctp_asconf_mgmt failed\n", __func__);
641 			sctp_bh_unlock_sock(sk);
642 		}
643 #if IS_ENABLED(CONFIG_IPV6)
644 free_next:
645 #endif
646 		list_del(&addrw->list);
647 		kfree(addrw);
648 	}
649 	spin_unlock_bh(&net->sctp.addr_wq_lock);
650 }
651 
652 static void sctp_free_addr_wq(struct net *net)
653 {
654 	struct sctp_sockaddr_entry *addrw;
655 	struct sctp_sockaddr_entry *temp;
656 
657 	spin_lock_bh(&net->sctp.addr_wq_lock);
658 	del_timer(&net->sctp.addr_wq_timer);
659 	list_for_each_entry_safe(addrw, temp, &net->sctp.addr_waitq, list) {
660 		list_del(&addrw->list);
661 		kfree(addrw);
662 	}
663 	spin_unlock_bh(&net->sctp.addr_wq_lock);
664 }
665 
666 /* lookup the entry for the same address in the addr_waitq
667  * sctp_addr_wq MUST be locked
668  */
669 static struct sctp_sockaddr_entry *sctp_addr_wq_lookup(struct net *net,
670 					struct sctp_sockaddr_entry *addr)
671 {
672 	struct sctp_sockaddr_entry *addrw;
673 
674 	list_for_each_entry(addrw, &net->sctp.addr_waitq, list) {
675 		if (addrw->a.sa.sa_family != addr->a.sa.sa_family)
676 			continue;
677 		if (addrw->a.sa.sa_family == AF_INET) {
678 			if (addrw->a.v4.sin_addr.s_addr ==
679 			    addr->a.v4.sin_addr.s_addr)
680 				return addrw;
681 		} else if (addrw->a.sa.sa_family == AF_INET6) {
682 			if (ipv6_addr_equal(&addrw->a.v6.sin6_addr,
683 			    &addr->a.v6.sin6_addr))
684 				return addrw;
685 		}
686 	}
687 	return NULL;
688 }
689 
690 void sctp_addr_wq_mgmt(struct net *net, struct sctp_sockaddr_entry *addr, int cmd)
691 {
692 	struct sctp_sockaddr_entry *addrw;
693 	unsigned long timeo_val;
694 
695 	/* first, we check if an opposite message already exist in the queue.
696 	 * If we found such message, it is removed.
697 	 * This operation is a bit stupid, but the DHCP client attaches the
698 	 * new address after a couple of addition and deletion of that address
699 	 */
700 
701 	spin_lock_bh(&net->sctp.addr_wq_lock);
702 	/* Offsets existing events in addr_wq */
703 	addrw = sctp_addr_wq_lookup(net, addr);
704 	if (addrw) {
705 		if (addrw->state != cmd) {
706 			pr_debug("%s: offsets existing entry for %d, addr:%pISc "
707 				 "in wq:%p\n", __func__, addrw->state, &addrw->a.sa,
708 				 &net->sctp.addr_waitq);
709 
710 			list_del(&addrw->list);
711 			kfree(addrw);
712 		}
713 		spin_unlock_bh(&net->sctp.addr_wq_lock);
714 		return;
715 	}
716 
717 	/* OK, we have to add the new address to the wait queue */
718 	addrw = kmemdup(addr, sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
719 	if (addrw == NULL) {
720 		spin_unlock_bh(&net->sctp.addr_wq_lock);
721 		return;
722 	}
723 	addrw->state = cmd;
724 	list_add_tail(&addrw->list, &net->sctp.addr_waitq);
725 
726 	pr_debug("%s: add new entry for cmd:%d, addr:%pISc in wq:%p\n",
727 		 __func__, addrw->state, &addrw->a.sa, &net->sctp.addr_waitq);
728 
729 	if (!timer_pending(&net->sctp.addr_wq_timer)) {
730 		timeo_val = jiffies;
731 		timeo_val += msecs_to_jiffies(SCTP_ADDRESS_TICK_DELAY);
732 		mod_timer(&net->sctp.addr_wq_timer, timeo_val);
733 	}
734 	spin_unlock_bh(&net->sctp.addr_wq_lock);
735 }
736 
737 /* Event handler for inet address addition/deletion events.
738  * The sctp_local_addr_list needs to be protocted by a spin lock since
739  * multiple notifiers (say IPv4 and IPv6) may be running at the same
740  * time and thus corrupt the list.
741  * The reader side is protected with RCU.
742  */
743 static int sctp_inetaddr_event(struct notifier_block *this, unsigned long ev,
744 			       void *ptr)
745 {
746 	struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
747 	struct sctp_sockaddr_entry *addr = NULL;
748 	struct sctp_sockaddr_entry *temp;
749 	struct net *net = dev_net(ifa->ifa_dev->dev);
750 	int found = 0;
751 
752 	switch (ev) {
753 	case NETDEV_UP:
754 		addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
755 		if (addr) {
756 			addr->a.v4.sin_family = AF_INET;
757 			addr->a.v4.sin_port = 0;
758 			addr->a.v4.sin_addr.s_addr = ifa->ifa_local;
759 			addr->valid = 1;
760 			spin_lock_bh(&net->sctp.local_addr_lock);
761 			list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
762 			sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
763 			spin_unlock_bh(&net->sctp.local_addr_lock);
764 		}
765 		break;
766 	case NETDEV_DOWN:
767 		spin_lock_bh(&net->sctp.local_addr_lock);
768 		list_for_each_entry_safe(addr, temp,
769 					&net->sctp.local_addr_list, list) {
770 			if (addr->a.sa.sa_family == AF_INET &&
771 					addr->a.v4.sin_addr.s_addr ==
772 					ifa->ifa_local) {
773 				sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
774 				found = 1;
775 				addr->valid = 0;
776 				list_del_rcu(&addr->list);
777 				break;
778 			}
779 		}
780 		spin_unlock_bh(&net->sctp.local_addr_lock);
781 		if (found)
782 			kfree_rcu(addr, rcu);
783 		break;
784 	}
785 
786 	return NOTIFY_DONE;
787 }
788 
789 /*
790  * Initialize the control inode/socket with a control endpoint data
791  * structure.  This endpoint is reserved exclusively for the OOTB processing.
792  */
793 static int sctp_ctl_sock_init(struct net *net)
794 {
795 	int err;
796 	sa_family_t family = PF_INET;
797 
798 	if (sctp_get_pf_specific(PF_INET6))
799 		family = PF_INET6;
800 
801 	err = inet_ctl_sock_create(&net->sctp.ctl_sock, family,
802 				   SOCK_SEQPACKET, IPPROTO_SCTP, net);
803 
804 	/* If IPv6 socket could not be created, try the IPv4 socket */
805 	if (err < 0 && family == PF_INET6)
806 		err = inet_ctl_sock_create(&net->sctp.ctl_sock, AF_INET,
807 					   SOCK_SEQPACKET, IPPROTO_SCTP,
808 					   net);
809 
810 	if (err < 0) {
811 		pr_err("Failed to create the SCTP control socket\n");
812 		return err;
813 	}
814 	return 0;
815 }
816 
817 /* Register address family specific functions. */
818 int sctp_register_af(struct sctp_af *af)
819 {
820 	switch (af->sa_family) {
821 	case AF_INET:
822 		if (sctp_af_v4_specific)
823 			return 0;
824 		sctp_af_v4_specific = af;
825 		break;
826 	case AF_INET6:
827 		if (sctp_af_v6_specific)
828 			return 0;
829 		sctp_af_v6_specific = af;
830 		break;
831 	default:
832 		return 0;
833 	}
834 
835 	INIT_LIST_HEAD(&af->list);
836 	list_add_tail(&af->list, &sctp_address_families);
837 	return 1;
838 }
839 
840 /* Get the table of functions for manipulating a particular address
841  * family.
842  */
843 struct sctp_af *sctp_get_af_specific(sa_family_t family)
844 {
845 	switch (family) {
846 	case AF_INET:
847 		return sctp_af_v4_specific;
848 	case AF_INET6:
849 		return sctp_af_v6_specific;
850 	default:
851 		return NULL;
852 	}
853 }
854 
855 /* Common code to initialize a AF_INET msg_name. */
856 static void sctp_inet_msgname(char *msgname, int *addr_len)
857 {
858 	struct sockaddr_in *sin;
859 
860 	sin = (struct sockaddr_in *)msgname;
861 	*addr_len = sizeof(struct sockaddr_in);
862 	sin->sin_family = AF_INET;
863 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
864 }
865 
866 /* Copy the primary address of the peer primary address as the msg_name. */
867 static void sctp_inet_event_msgname(struct sctp_ulpevent *event, char *msgname,
868 				    int *addr_len)
869 {
870 	struct sockaddr_in *sin, *sinfrom;
871 
872 	if (msgname) {
873 		struct sctp_association *asoc;
874 
875 		asoc = event->asoc;
876 		sctp_inet_msgname(msgname, addr_len);
877 		sin = (struct sockaddr_in *)msgname;
878 		sinfrom = &asoc->peer.primary_addr.v4;
879 		sin->sin_port = htons(asoc->peer.port);
880 		sin->sin_addr.s_addr = sinfrom->sin_addr.s_addr;
881 	}
882 }
883 
884 /* Initialize and copy out a msgname from an inbound skb. */
885 static void sctp_inet_skb_msgname(struct sk_buff *skb, char *msgname, int *len)
886 {
887 	if (msgname) {
888 		struct sctphdr *sh = sctp_hdr(skb);
889 		struct sockaddr_in *sin = (struct sockaddr_in *)msgname;
890 
891 		sctp_inet_msgname(msgname, len);
892 		sin->sin_port = sh->source;
893 		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
894 	}
895 }
896 
897 /* Do we support this AF? */
898 static int sctp_inet_af_supported(sa_family_t family, struct sctp_sock *sp)
899 {
900 	/* PF_INET only supports AF_INET addresses. */
901 	return AF_INET == family;
902 }
903 
904 /* Address matching with wildcards allowed. */
905 static int sctp_inet_cmp_addr(const union sctp_addr *addr1,
906 			      const union sctp_addr *addr2,
907 			      struct sctp_sock *opt)
908 {
909 	/* PF_INET only supports AF_INET addresses. */
910 	if (addr1->sa.sa_family != addr2->sa.sa_family)
911 		return 0;
912 	if (htonl(INADDR_ANY) == addr1->v4.sin_addr.s_addr ||
913 	    htonl(INADDR_ANY) == addr2->v4.sin_addr.s_addr)
914 		return 1;
915 	if (addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr)
916 		return 1;
917 
918 	return 0;
919 }
920 
921 /* Verify that provided sockaddr looks bindable.  Common verification has
922  * already been taken care of.
923  */
924 static int sctp_inet_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
925 {
926 	return sctp_v4_available(addr, opt);
927 }
928 
929 /* Verify that sockaddr looks sendable.  Common verification has already
930  * been taken care of.
931  */
932 static int sctp_inet_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
933 {
934 	return 1;
935 }
936 
937 /* Fill in Supported Address Type information for INIT and INIT-ACK
938  * chunks.  Returns number of addresses supported.
939  */
940 static int sctp_inet_supported_addrs(const struct sctp_sock *opt,
941 				     __be16 *types)
942 {
943 	types[0] = SCTP_PARAM_IPV4_ADDRESS;
944 	return 1;
945 }
946 
947 /* Wrapper routine that calls the ip transmit routine. */
948 static inline int sctp_v4_xmit(struct sk_buff *skb,
949 			       struct sctp_transport *transport)
950 {
951 	struct inet_sock *inet = inet_sk(skb->sk);
952 
953 	pr_debug("%s: skb:%p, len:%d, src:%pI4, dst:%pI4\n", __func__, skb,
954 		 skb->len, &transport->fl.u.ip4.saddr, &transport->fl.u.ip4.daddr);
955 
956 	inet->pmtudisc = transport->param_flags & SPP_PMTUD_ENABLE ?
957 			 IP_PMTUDISC_DO : IP_PMTUDISC_DONT;
958 
959 	SCTP_INC_STATS(sock_net(&inet->sk), SCTP_MIB_OUTSCTPPACKS);
960 
961 	return ip_queue_xmit(skb, &transport->fl);
962 }
963 
964 static struct sctp_af sctp_af_inet;
965 
966 static struct sctp_pf sctp_pf_inet = {
967 	.event_msgname = sctp_inet_event_msgname,
968 	.skb_msgname   = sctp_inet_skb_msgname,
969 	.af_supported  = sctp_inet_af_supported,
970 	.cmp_addr      = sctp_inet_cmp_addr,
971 	.bind_verify   = sctp_inet_bind_verify,
972 	.send_verify   = sctp_inet_send_verify,
973 	.supported_addrs = sctp_inet_supported_addrs,
974 	.create_accept_sk = sctp_v4_create_accept_sk,
975 	.addr_v4map	= sctp_v4_addr_v4map,
976 	.af            = &sctp_af_inet
977 };
978 
979 /* Notifier for inetaddr addition/deletion events.  */
980 static struct notifier_block sctp_inetaddr_notifier = {
981 	.notifier_call = sctp_inetaddr_event,
982 };
983 
984 /* Socket operations.  */
985 static const struct proto_ops inet_seqpacket_ops = {
986 	.family		   = PF_INET,
987 	.owner		   = THIS_MODULE,
988 	.release	   = inet_release,	/* Needs to be wrapped... */
989 	.bind		   = inet_bind,
990 	.connect	   = inet_dgram_connect,
991 	.socketpair	   = sock_no_socketpair,
992 	.accept		   = inet_accept,
993 	.getname	   = inet_getname,	/* Semantics are different.  */
994 	.poll		   = sctp_poll,
995 	.ioctl		   = inet_ioctl,
996 	.listen		   = sctp_inet_listen,
997 	.shutdown	   = inet_shutdown,	/* Looks harmless.  */
998 	.setsockopt	   = sock_common_setsockopt, /* IP_SOL IP_OPTION is a problem */
999 	.getsockopt	   = sock_common_getsockopt,
1000 	.sendmsg	   = inet_sendmsg,
1001 	.recvmsg	   = sock_common_recvmsg,
1002 	.mmap		   = sock_no_mmap,
1003 	.sendpage	   = sock_no_sendpage,
1004 #ifdef CONFIG_COMPAT
1005 	.compat_setsockopt = compat_sock_common_setsockopt,
1006 	.compat_getsockopt = compat_sock_common_getsockopt,
1007 #endif
1008 };
1009 
1010 /* Registration with AF_INET family.  */
1011 static struct inet_protosw sctp_seqpacket_protosw = {
1012 	.type       = SOCK_SEQPACKET,
1013 	.protocol   = IPPROTO_SCTP,
1014 	.prot       = &sctp_prot,
1015 	.ops        = &inet_seqpacket_ops,
1016 	.no_check   = 0,
1017 	.flags      = SCTP_PROTOSW_FLAG
1018 };
1019 static struct inet_protosw sctp_stream_protosw = {
1020 	.type       = SOCK_STREAM,
1021 	.protocol   = IPPROTO_SCTP,
1022 	.prot       = &sctp_prot,
1023 	.ops        = &inet_seqpacket_ops,
1024 	.no_check   = 0,
1025 	.flags      = SCTP_PROTOSW_FLAG
1026 };
1027 
1028 /* Register with IP layer.  */
1029 static const struct net_protocol sctp_protocol = {
1030 	.handler     = sctp_rcv,
1031 	.err_handler = sctp_v4_err,
1032 	.no_policy   = 1,
1033 	.netns_ok    = 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 	status = 0;
1465 out:
1466 	return status;
1467 err_v6_add_protocol:
1468 	sctp_v4_del_protocol();
1469 err_add_protocol:
1470 	unregister_pernet_subsys(&sctp_net_ops);
1471 err_register_pernet_subsys:
1472 	sctp_v6_protosw_exit();
1473 err_v6_protosw_init:
1474 	sctp_v4_protosw_exit();
1475 err_protosw_init:
1476 	sctp_v4_pf_exit();
1477 	sctp_v6_pf_exit();
1478 	sctp_sysctl_unregister();
1479 	free_pages((unsigned long)sctp_port_hashtable,
1480 		   get_order(sctp_port_hashsize *
1481 			     sizeof(struct sctp_bind_hashbucket)));
1482 err_bhash_alloc:
1483 	kfree(sctp_ep_hashtable);
1484 err_ehash_alloc:
1485 	free_pages((unsigned long)sctp_assoc_hashtable,
1486 		   get_order(sctp_assoc_hashsize *
1487 			     sizeof(struct sctp_hashbucket)));
1488 err_ahash_alloc:
1489 	percpu_counter_destroy(&sctp_sockets_allocated);
1490 err_percpu_counter_init:
1491 	kmem_cache_destroy(sctp_chunk_cachep);
1492 err_chunk_cachep:
1493 	kmem_cache_destroy(sctp_bucket_cachep);
1494 	goto out;
1495 }
1496 
1497 /* Exit handler for the SCTP protocol.  */
1498 static __exit void sctp_exit(void)
1499 {
1500 	/* BUG.  This should probably do something useful like clean
1501 	 * up all the remaining associations and all that memory.
1502 	 */
1503 
1504 	/* Unregister with inet6/inet layers. */
1505 	sctp_v6_del_protocol();
1506 	sctp_v4_del_protocol();
1507 
1508 	unregister_pernet_subsys(&sctp_net_ops);
1509 
1510 	/* Free protosw registrations */
1511 	sctp_v6_protosw_exit();
1512 	sctp_v4_protosw_exit();
1513 
1514 	/* Unregister with socket layer. */
1515 	sctp_v6_pf_exit();
1516 	sctp_v4_pf_exit();
1517 
1518 	sctp_sysctl_unregister();
1519 
1520 	free_pages((unsigned long)sctp_assoc_hashtable,
1521 		   get_order(sctp_assoc_hashsize *
1522 			     sizeof(struct sctp_hashbucket)));
1523 	kfree(sctp_ep_hashtable);
1524 	free_pages((unsigned long)sctp_port_hashtable,
1525 		   get_order(sctp_port_hashsize *
1526 			     sizeof(struct sctp_bind_hashbucket)));
1527 
1528 	percpu_counter_destroy(&sctp_sockets_allocated);
1529 
1530 	rcu_barrier(); /* Wait for completion of call_rcu()'s */
1531 
1532 	kmem_cache_destroy(sctp_chunk_cachep);
1533 	kmem_cache_destroy(sctp_bucket_cachep);
1534 }
1535 
1536 module_init(sctp_init);
1537 module_exit(sctp_exit);
1538 
1539 /*
1540  * __stringify doesn't likes enums, so use IPPROTO_SCTP value (132) directly.
1541  */
1542 MODULE_ALIAS("net-pf-" __stringify(PF_INET) "-proto-132");
1543 MODULE_ALIAS("net-pf-" __stringify(PF_INET6) "-proto-132");
1544 MODULE_AUTHOR("Linux Kernel SCTP developers <linux-sctp@vger.kernel.org>");
1545 MODULE_DESCRIPTION("Support for the SCTP protocol (RFC2960)");
1546 module_param_named(no_checksums, sctp_checksum_disable, bool, 0644);
1547 MODULE_PARM_DESC(no_checksums, "Disable checksums computing and verification");
1548 MODULE_LICENSE("GPL");
1549