xref: /linux/net/sctp/protocol.c (revision 6fdcba32711044c35c0e1b094cbd8f3f0b4472c9)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* SCTP kernel implementation
3  * (C) Copyright IBM Corp. 2001, 2004
4  * Copyright (c) 1999-2000 Cisco, Inc.
5  * Copyright (c) 1999-2001 Motorola, Inc.
6  * Copyright (c) 2001 Intel Corp.
7  * Copyright (c) 2001 Nokia, Inc.
8  * Copyright (c) 2001 La Monte H.P. Yarroll
9  *
10  * This file is part of the SCTP kernel implementation
11  *
12  * Initialization/cleanup for SCTP protocol support.
13  *
14  * Please send any bug reports or fixes you make to the
15  * email address(es):
16  *    lksctp developers <linux-sctp@vger.kernel.org>
17  *
18  * Written or modified by:
19  *    La Monte H.P. Yarroll <piggy@acm.org>
20  *    Karl Knutson <karl@athena.chicago.il.us>
21  *    Jon Grimm <jgrimm@us.ibm.com>
22  *    Sridhar Samudrala <sri@us.ibm.com>
23  *    Daisy Chang <daisyc@us.ibm.com>
24  *    Ardelle Fan <ardelle.fan@intel.com>
25  */
26 
27 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
28 
29 #include <linux/module.h>
30 #include <linux/init.h>
31 #include <linux/netdevice.h>
32 #include <linux/inetdevice.h>
33 #include <linux/seq_file.h>
34 #include <linux/memblock.h>
35 #include <linux/highmem.h>
36 #include <linux/swap.h>
37 #include <linux/slab.h>
38 #include <net/net_namespace.h>
39 #include <net/protocol.h>
40 #include <net/ip.h>
41 #include <net/ipv6.h>
42 #include <net/route.h>
43 #include <net/sctp/sctp.h>
44 #include <net/addrconf.h>
45 #include <net/inet_common.h>
46 #include <net/inet_ecn.h>
47 
48 #define MAX_SCTP_PORT_HASH_ENTRIES (64 * 1024)
49 
50 /* Global data structures. */
51 struct sctp_globals sctp_globals __read_mostly;
52 
53 struct idr sctp_assocs_id;
54 DEFINE_SPINLOCK(sctp_assocs_id_lock);
55 
56 static struct sctp_pf *sctp_pf_inet6_specific;
57 static struct sctp_pf *sctp_pf_inet_specific;
58 static struct sctp_af *sctp_af_v4_specific;
59 static struct sctp_af *sctp_af_v6_specific;
60 
61 struct kmem_cache *sctp_chunk_cachep __read_mostly;
62 struct kmem_cache *sctp_bucket_cachep __read_mostly;
63 
64 long sysctl_sctp_mem[3];
65 int sysctl_sctp_rmem[3];
66 int sysctl_sctp_wmem[3];
67 
68 /* Private helper to extract ipv4 address and stash them in
69  * the protocol structure.
70  */
71 static void sctp_v4_copy_addrlist(struct list_head *addrlist,
72 				  struct net_device *dev)
73 {
74 	struct in_device *in_dev;
75 	struct in_ifaddr *ifa;
76 	struct sctp_sockaddr_entry *addr;
77 
78 	rcu_read_lock();
79 	if ((in_dev = __in_dev_get_rcu(dev)) == NULL) {
80 		rcu_read_unlock();
81 		return;
82 	}
83 
84 	in_dev_for_each_ifa_rcu(ifa, in_dev) {
85 		/* Add the address to the local list.  */
86 		addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
87 		if (addr) {
88 			addr->a.v4.sin_family = AF_INET;
89 			addr->a.v4.sin_addr.s_addr = ifa->ifa_local;
90 			addr->valid = 1;
91 			INIT_LIST_HEAD(&addr->list);
92 			list_add_tail(&addr->list, addrlist);
93 		}
94 	}
95 
96 	rcu_read_unlock();
97 }
98 
99 /* Extract our IP addresses from the system and stash them in the
100  * protocol structure.
101  */
102 static void sctp_get_local_addr_list(struct net *net)
103 {
104 	struct net_device *dev;
105 	struct list_head *pos;
106 	struct sctp_af *af;
107 
108 	rcu_read_lock();
109 	for_each_netdev_rcu(net, dev) {
110 		list_for_each(pos, &sctp_address_families) {
111 			af = list_entry(pos, struct sctp_af, list);
112 			af->copy_addrlist(&net->sctp.local_addr_list, dev);
113 		}
114 	}
115 	rcu_read_unlock();
116 }
117 
118 /* Free the existing local addresses.  */
119 static void sctp_free_local_addr_list(struct net *net)
120 {
121 	struct sctp_sockaddr_entry *addr;
122 	struct list_head *pos, *temp;
123 
124 	list_for_each_safe(pos, temp, &net->sctp.local_addr_list) {
125 		addr = list_entry(pos, struct sctp_sockaddr_entry, list);
126 		list_del(pos);
127 		kfree(addr);
128 	}
129 }
130 
131 /* Copy the local addresses which are valid for 'scope' into 'bp'.  */
132 int sctp_copy_local_addr_list(struct net *net, struct sctp_bind_addr *bp,
133 			      enum sctp_scope scope, gfp_t gfp, int copy_flags)
134 {
135 	struct sctp_sockaddr_entry *addr;
136 	union sctp_addr laddr;
137 	int error = 0;
138 
139 	rcu_read_lock();
140 	list_for_each_entry_rcu(addr, &net->sctp.local_addr_list, list) {
141 		if (!addr->valid)
142 			continue;
143 		if (!sctp_in_scope(net, &addr->a, scope))
144 			continue;
145 
146 		/* Now that the address is in scope, check to see if
147 		 * the address type is really supported by the local
148 		 * sock as well as the remote peer.
149 		 */
150 		if (addr->a.sa.sa_family == AF_INET &&
151 		    !(copy_flags & SCTP_ADDR4_PEERSUPP))
152 			continue;
153 		if (addr->a.sa.sa_family == AF_INET6 &&
154 		    (!(copy_flags & SCTP_ADDR6_ALLOWED) ||
155 		     !(copy_flags & SCTP_ADDR6_PEERSUPP)))
156 			continue;
157 
158 		laddr = addr->a;
159 		/* also works for setting ipv6 address port */
160 		laddr.v4.sin_port = htons(bp->port);
161 		if (sctp_bind_addr_state(bp, &laddr) != -1)
162 			continue;
163 
164 		error = sctp_add_bind_addr(bp, &addr->a, sizeof(addr->a),
165 					   SCTP_ADDR_SRC, GFP_ATOMIC);
166 		if (error)
167 			break;
168 	}
169 
170 	rcu_read_unlock();
171 	return error;
172 }
173 
174 /* Copy over any ip options */
175 static void sctp_v4_copy_ip_options(struct sock *sk, struct sock *newsk)
176 {
177 	struct inet_sock *newinet, *inet = inet_sk(sk);
178 	struct ip_options_rcu *inet_opt, *newopt = NULL;
179 
180 	newinet = inet_sk(newsk);
181 
182 	rcu_read_lock();
183 	inet_opt = rcu_dereference(inet->inet_opt);
184 	if (inet_opt) {
185 		newopt = sock_kmalloc(newsk, sizeof(*inet_opt) +
186 				      inet_opt->opt.optlen, GFP_ATOMIC);
187 		if (newopt)
188 			memcpy(newopt, inet_opt, sizeof(*inet_opt) +
189 			       inet_opt->opt.optlen);
190 		else
191 			pr_err("%s: Failed to copy ip options\n", __func__);
192 	}
193 	RCU_INIT_POINTER(newinet->inet_opt, newopt);
194 	rcu_read_unlock();
195 }
196 
197 /* Account for the IP options */
198 static int sctp_v4_ip_options_len(struct sock *sk)
199 {
200 	struct inet_sock *inet = inet_sk(sk);
201 	struct ip_options_rcu *inet_opt;
202 	int len = 0;
203 
204 	rcu_read_lock();
205 	inet_opt = rcu_dereference(inet->inet_opt);
206 	if (inet_opt)
207 		len = inet_opt->opt.optlen;
208 
209 	rcu_read_unlock();
210 	return len;
211 }
212 
213 /* Initialize a sctp_addr from in incoming skb.  */
214 static void sctp_v4_from_skb(union sctp_addr *addr, struct sk_buff *skb,
215 			     int is_saddr)
216 {
217 	/* Always called on head skb, so this is safe */
218 	struct sctphdr *sh = sctp_hdr(skb);
219 	struct sockaddr_in *sa = &addr->v4;
220 
221 	addr->v4.sin_family = AF_INET;
222 
223 	if (is_saddr) {
224 		sa->sin_port = sh->source;
225 		sa->sin_addr.s_addr = ip_hdr(skb)->saddr;
226 	} else {
227 		sa->sin_port = sh->dest;
228 		sa->sin_addr.s_addr = ip_hdr(skb)->daddr;
229 	}
230 }
231 
232 /* Initialize an sctp_addr from a socket. */
233 static void sctp_v4_from_sk(union sctp_addr *addr, struct sock *sk)
234 {
235 	addr->v4.sin_family = AF_INET;
236 	addr->v4.sin_port = 0;
237 	addr->v4.sin_addr.s_addr = inet_sk(sk)->inet_rcv_saddr;
238 }
239 
240 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
241 static void sctp_v4_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
242 {
243 	inet_sk(sk)->inet_rcv_saddr = addr->v4.sin_addr.s_addr;
244 }
245 
246 /* Initialize sk->sk_daddr from sctp_addr. */
247 static void sctp_v4_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
248 {
249 	inet_sk(sk)->inet_daddr = addr->v4.sin_addr.s_addr;
250 }
251 
252 /* Initialize a sctp_addr from an address parameter. */
253 static void sctp_v4_from_addr_param(union sctp_addr *addr,
254 				    union sctp_addr_param *param,
255 				    __be16 port, int iif)
256 {
257 	addr->v4.sin_family = AF_INET;
258 	addr->v4.sin_port = port;
259 	addr->v4.sin_addr.s_addr = param->v4.addr.s_addr;
260 }
261 
262 /* Initialize an address parameter from a sctp_addr and return the length
263  * of the address parameter.
264  */
265 static int sctp_v4_to_addr_param(const union sctp_addr *addr,
266 				 union sctp_addr_param *param)
267 {
268 	int length = sizeof(struct sctp_ipv4addr_param);
269 
270 	param->v4.param_hdr.type = SCTP_PARAM_IPV4_ADDRESS;
271 	param->v4.param_hdr.length = htons(length);
272 	param->v4.addr.s_addr = addr->v4.sin_addr.s_addr;
273 
274 	return length;
275 }
276 
277 /* Initialize a sctp_addr from a dst_entry. */
278 static void sctp_v4_dst_saddr(union sctp_addr *saddr, struct flowi4 *fl4,
279 			      __be16 port)
280 {
281 	saddr->v4.sin_family = AF_INET;
282 	saddr->v4.sin_port = port;
283 	saddr->v4.sin_addr.s_addr = fl4->saddr;
284 }
285 
286 /* Compare two addresses exactly. */
287 static int sctp_v4_cmp_addr(const union sctp_addr *addr1,
288 			    const union sctp_addr *addr2)
289 {
290 	if (addr1->sa.sa_family != addr2->sa.sa_family)
291 		return 0;
292 	if (addr1->v4.sin_port != addr2->v4.sin_port)
293 		return 0;
294 	if (addr1->v4.sin_addr.s_addr != addr2->v4.sin_addr.s_addr)
295 		return 0;
296 
297 	return 1;
298 }
299 
300 /* Initialize addr struct to INADDR_ANY. */
301 static void sctp_v4_inaddr_any(union sctp_addr *addr, __be16 port)
302 {
303 	addr->v4.sin_family = AF_INET;
304 	addr->v4.sin_addr.s_addr = htonl(INADDR_ANY);
305 	addr->v4.sin_port = port;
306 }
307 
308 /* Is this a wildcard address? */
309 static int sctp_v4_is_any(const union sctp_addr *addr)
310 {
311 	return htonl(INADDR_ANY) == addr->v4.sin_addr.s_addr;
312 }
313 
314 /* This function checks if the address is a valid address to be used for
315  * SCTP binding.
316  *
317  * Output:
318  * Return 0 - If the address is a non-unicast or an illegal address.
319  * Return 1 - If the address is a unicast.
320  */
321 static int sctp_v4_addr_valid(union sctp_addr *addr,
322 			      struct sctp_sock *sp,
323 			      const struct sk_buff *skb)
324 {
325 	/* IPv4 addresses not allowed */
326 	if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
327 		return 0;
328 
329 	/* Is this a non-unicast address or a unusable SCTP address? */
330 	if (IS_IPV4_UNUSABLE_ADDRESS(addr->v4.sin_addr.s_addr))
331 		return 0;
332 
333 	/* Is this a broadcast address? */
334 	if (skb && skb_rtable(skb)->rt_flags & RTCF_BROADCAST)
335 		return 0;
336 
337 	return 1;
338 }
339 
340 /* Should this be available for binding?   */
341 static int sctp_v4_available(union sctp_addr *addr, struct sctp_sock *sp)
342 {
343 	struct net *net = sock_net(&sp->inet.sk);
344 	int ret = inet_addr_type(net, addr->v4.sin_addr.s_addr);
345 
346 
347 	if (addr->v4.sin_addr.s_addr != htonl(INADDR_ANY) &&
348 	   ret != RTN_LOCAL &&
349 	   !sp->inet.freebind &&
350 	   !net->ipv4.sysctl_ip_nonlocal_bind)
351 		return 0;
352 
353 	if (ipv6_only_sock(sctp_opt2sk(sp)))
354 		return 0;
355 
356 	return 1;
357 }
358 
359 /* Checking the loopback, private and other address scopes as defined in
360  * RFC 1918.   The IPv4 scoping is based on the draft for SCTP IPv4
361  * scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>.
362  *
363  * Level 0 - unusable SCTP addresses
364  * Level 1 - loopback address
365  * Level 2 - link-local addresses
366  * Level 3 - private addresses.
367  * Level 4 - global addresses
368  * For INIT and INIT-ACK address list, let L be the level of
369  * of requested destination address, sender and receiver
370  * SHOULD include all of its addresses with level greater
371  * than or equal to L.
372  *
373  * IPv4 scoping can be controlled through sysctl option
374  * net.sctp.addr_scope_policy
375  */
376 static enum sctp_scope sctp_v4_scope(union sctp_addr *addr)
377 {
378 	enum sctp_scope retval;
379 
380 	/* Check for unusable SCTP addresses. */
381 	if (IS_IPV4_UNUSABLE_ADDRESS(addr->v4.sin_addr.s_addr)) {
382 		retval =  SCTP_SCOPE_UNUSABLE;
383 	} else if (ipv4_is_loopback(addr->v4.sin_addr.s_addr)) {
384 		retval = SCTP_SCOPE_LOOPBACK;
385 	} else if (ipv4_is_linklocal_169(addr->v4.sin_addr.s_addr)) {
386 		retval = SCTP_SCOPE_LINK;
387 	} else if (ipv4_is_private_10(addr->v4.sin_addr.s_addr) ||
388 		   ipv4_is_private_172(addr->v4.sin_addr.s_addr) ||
389 		   ipv4_is_private_192(addr->v4.sin_addr.s_addr)) {
390 		retval = SCTP_SCOPE_PRIVATE;
391 	} else {
392 		retval = SCTP_SCOPE_GLOBAL;
393 	}
394 
395 	return retval;
396 }
397 
398 /* Returns a valid dst cache entry for the given source and destination ip
399  * addresses. If an association is passed, trys to get a dst entry with a
400  * source address that matches an address in the bind address list.
401  */
402 static void sctp_v4_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
403 				struct flowi *fl, struct sock *sk)
404 {
405 	struct sctp_association *asoc = t->asoc;
406 	struct rtable *rt;
407 	struct flowi4 *fl4 = &fl->u.ip4;
408 	struct sctp_bind_addr *bp;
409 	struct sctp_sockaddr_entry *laddr;
410 	struct dst_entry *dst = NULL;
411 	union sctp_addr *daddr = &t->ipaddr;
412 	union sctp_addr dst_saddr;
413 	__u8 tos = inet_sk(sk)->tos;
414 
415 	if (t->dscp & SCTP_DSCP_SET_MASK)
416 		tos = t->dscp & SCTP_DSCP_VAL_MASK;
417 	memset(fl4, 0x0, sizeof(struct flowi4));
418 	fl4->daddr  = daddr->v4.sin_addr.s_addr;
419 	fl4->fl4_dport = daddr->v4.sin_port;
420 	fl4->flowi4_proto = IPPROTO_SCTP;
421 	if (asoc) {
422 		fl4->flowi4_tos = RT_CONN_FLAGS_TOS(asoc->base.sk, tos);
423 		fl4->flowi4_oif = asoc->base.sk->sk_bound_dev_if;
424 		fl4->fl4_sport = htons(asoc->base.bind_addr.port);
425 	}
426 	if (saddr) {
427 		fl4->saddr = saddr->v4.sin_addr.s_addr;
428 		if (!fl4->fl4_sport)
429 			fl4->fl4_sport = saddr->v4.sin_port;
430 	}
431 
432 	pr_debug("%s: dst:%pI4, src:%pI4 - ", __func__, &fl4->daddr,
433 		 &fl4->saddr);
434 
435 	rt = ip_route_output_key(sock_net(sk), fl4);
436 	if (!IS_ERR(rt))
437 		dst = &rt->dst;
438 
439 	/* If there is no association or if a source address is passed, no
440 	 * more validation is required.
441 	 */
442 	if (!asoc || saddr)
443 		goto out;
444 
445 	bp = &asoc->base.bind_addr;
446 
447 	if (dst) {
448 		/* Walk through the bind address list and look for a bind
449 		 * address that matches the source address of the returned dst.
450 		 */
451 		sctp_v4_dst_saddr(&dst_saddr, fl4, htons(bp->port));
452 		rcu_read_lock();
453 		list_for_each_entry_rcu(laddr, &bp->address_list, list) {
454 			if (!laddr->valid || (laddr->state == SCTP_ADDR_DEL) ||
455 			    (laddr->state != SCTP_ADDR_SRC &&
456 			    !asoc->src_out_of_asoc_ok))
457 				continue;
458 			if (sctp_v4_cmp_addr(&dst_saddr, &laddr->a))
459 				goto out_unlock;
460 		}
461 		rcu_read_unlock();
462 
463 		/* None of the bound addresses match the source address of the
464 		 * dst. So release it.
465 		 */
466 		dst_release(dst);
467 		dst = NULL;
468 	}
469 
470 	/* Walk through the bind address list and try to get a dst that
471 	 * matches a bind address as the source address.
472 	 */
473 	rcu_read_lock();
474 	list_for_each_entry_rcu(laddr, &bp->address_list, list) {
475 		struct net_device *odev;
476 
477 		if (!laddr->valid)
478 			continue;
479 		if (laddr->state != SCTP_ADDR_SRC ||
480 		    AF_INET != laddr->a.sa.sa_family)
481 			continue;
482 
483 		fl4->fl4_sport = laddr->a.v4.sin_port;
484 		flowi4_update_output(fl4,
485 				     asoc->base.sk->sk_bound_dev_if,
486 				     RT_CONN_FLAGS_TOS(asoc->base.sk, tos),
487 				     daddr->v4.sin_addr.s_addr,
488 				     laddr->a.v4.sin_addr.s_addr);
489 
490 		rt = ip_route_output_key(sock_net(sk), fl4);
491 		if (IS_ERR(rt))
492 			continue;
493 
494 		/* Ensure the src address belongs to the output
495 		 * interface.
496 		 */
497 		odev = __ip_dev_find(sock_net(sk), laddr->a.v4.sin_addr.s_addr,
498 				     false);
499 		if (!odev || odev->ifindex != fl4->flowi4_oif) {
500 			if (!dst)
501 				dst = &rt->dst;
502 			else
503 				dst_release(&rt->dst);
504 			continue;
505 		}
506 
507 		dst_release(dst);
508 		dst = &rt->dst;
509 		break;
510 	}
511 
512 out_unlock:
513 	rcu_read_unlock();
514 out:
515 	t->dst = dst;
516 	if (dst)
517 		pr_debug("rt_dst:%pI4, rt_src:%pI4\n",
518 			 &fl4->daddr, &fl4->saddr);
519 	else
520 		pr_debug("no route\n");
521 }
522 
523 /* For v4, the source address is cached in the route entry(dst). So no need
524  * to cache it separately and hence this is an empty routine.
525  */
526 static void sctp_v4_get_saddr(struct sctp_sock *sk,
527 			      struct sctp_transport *t,
528 			      struct flowi *fl)
529 {
530 	union sctp_addr *saddr = &t->saddr;
531 	struct rtable *rt = (struct rtable *)t->dst;
532 
533 	if (rt) {
534 		saddr->v4.sin_family = AF_INET;
535 		saddr->v4.sin_addr.s_addr = fl->u.ip4.saddr;
536 	}
537 }
538 
539 /* What interface did this skb arrive on? */
540 static int sctp_v4_skb_iif(const struct sk_buff *skb)
541 {
542 	return inet_iif(skb);
543 }
544 
545 /* Was this packet marked by Explicit Congestion Notification? */
546 static int sctp_v4_is_ce(const struct sk_buff *skb)
547 {
548 	return INET_ECN_is_ce(ip_hdr(skb)->tos);
549 }
550 
551 /* Create and initialize a new sk for the socket returned by accept(). */
552 static struct sock *sctp_v4_create_accept_sk(struct sock *sk,
553 					     struct sctp_association *asoc,
554 					     bool kern)
555 {
556 	struct sock *newsk = sk_alloc(sock_net(sk), PF_INET, GFP_KERNEL,
557 			sk->sk_prot, kern);
558 	struct inet_sock *newinet;
559 
560 	if (!newsk)
561 		goto out;
562 
563 	sock_init_data(NULL, newsk);
564 
565 	sctp_copy_sock(newsk, sk, asoc);
566 	sock_reset_flag(newsk, SOCK_ZAPPED);
567 
568 	sctp_v4_copy_ip_options(sk, newsk);
569 
570 	newinet = inet_sk(newsk);
571 
572 	newinet->inet_daddr = asoc->peer.primary_addr.v4.sin_addr.s_addr;
573 
574 	sk_refcnt_debug_inc(newsk);
575 
576 	if (newsk->sk_prot->init(newsk)) {
577 		sk_common_release(newsk);
578 		newsk = NULL;
579 	}
580 
581 out:
582 	return newsk;
583 }
584 
585 static int sctp_v4_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
586 {
587 	/* No address mapping for V4 sockets */
588 	memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
589 	return sizeof(struct sockaddr_in);
590 }
591 
592 /* Dump the v4 addr to the seq file. */
593 static void sctp_v4_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
594 {
595 	seq_printf(seq, "%pI4 ", &addr->v4.sin_addr);
596 }
597 
598 static void sctp_v4_ecn_capable(struct sock *sk)
599 {
600 	INET_ECN_xmit(sk);
601 }
602 
603 static void sctp_addr_wq_timeout_handler(struct timer_list *t)
604 {
605 	struct net *net = from_timer(net, t, sctp.addr_wq_timer);
606 	struct sctp_sockaddr_entry *addrw, *temp;
607 	struct sctp_sock *sp;
608 
609 	spin_lock_bh(&net->sctp.addr_wq_lock);
610 
611 	list_for_each_entry_safe(addrw, temp, &net->sctp.addr_waitq, list) {
612 		pr_debug("%s: the first ent in wq:%p is addr:%pISc for cmd:%d at "
613 			 "entry:%p\n", __func__, &net->sctp.addr_waitq, &addrw->a.sa,
614 			 addrw->state, addrw);
615 
616 #if IS_ENABLED(CONFIG_IPV6)
617 		/* Now we send an ASCONF for each association */
618 		/* Note. we currently don't handle link local IPv6 addressees */
619 		if (addrw->a.sa.sa_family == AF_INET6) {
620 			struct in6_addr *in6;
621 
622 			if (ipv6_addr_type(&addrw->a.v6.sin6_addr) &
623 			    IPV6_ADDR_LINKLOCAL)
624 				goto free_next;
625 
626 			in6 = (struct in6_addr *)&addrw->a.v6.sin6_addr;
627 			if (ipv6_chk_addr(net, in6, NULL, 0) == 0 &&
628 			    addrw->state == SCTP_ADDR_NEW) {
629 				unsigned long timeo_val;
630 
631 				pr_debug("%s: this is on DAD, trying %d sec "
632 					 "later\n", __func__,
633 					 SCTP_ADDRESS_TICK_DELAY);
634 
635 				timeo_val = jiffies;
636 				timeo_val += msecs_to_jiffies(SCTP_ADDRESS_TICK_DELAY);
637 				mod_timer(&net->sctp.addr_wq_timer, timeo_val);
638 				break;
639 			}
640 		}
641 #endif
642 		list_for_each_entry(sp, &net->sctp.auto_asconf_splist, auto_asconf_list) {
643 			struct sock *sk;
644 
645 			sk = sctp_opt2sk(sp);
646 			/* ignore bound-specific endpoints */
647 			if (!sctp_is_ep_boundall(sk))
648 				continue;
649 			bh_lock_sock(sk);
650 			if (sctp_asconf_mgmt(sp, addrw) < 0)
651 				pr_debug("%s: sctp_asconf_mgmt failed\n", __func__);
652 			bh_unlock_sock(sk);
653 		}
654 #if IS_ENABLED(CONFIG_IPV6)
655 free_next:
656 #endif
657 		list_del(&addrw->list);
658 		kfree(addrw);
659 	}
660 	spin_unlock_bh(&net->sctp.addr_wq_lock);
661 }
662 
663 static void sctp_free_addr_wq(struct net *net)
664 {
665 	struct sctp_sockaddr_entry *addrw;
666 	struct sctp_sockaddr_entry *temp;
667 
668 	spin_lock_bh(&net->sctp.addr_wq_lock);
669 	del_timer(&net->sctp.addr_wq_timer);
670 	list_for_each_entry_safe(addrw, temp, &net->sctp.addr_waitq, list) {
671 		list_del(&addrw->list);
672 		kfree(addrw);
673 	}
674 	spin_unlock_bh(&net->sctp.addr_wq_lock);
675 }
676 
677 /* lookup the entry for the same address in the addr_waitq
678  * sctp_addr_wq MUST be locked
679  */
680 static struct sctp_sockaddr_entry *sctp_addr_wq_lookup(struct net *net,
681 					struct sctp_sockaddr_entry *addr)
682 {
683 	struct sctp_sockaddr_entry *addrw;
684 
685 	list_for_each_entry(addrw, &net->sctp.addr_waitq, list) {
686 		if (addrw->a.sa.sa_family != addr->a.sa.sa_family)
687 			continue;
688 		if (addrw->a.sa.sa_family == AF_INET) {
689 			if (addrw->a.v4.sin_addr.s_addr ==
690 			    addr->a.v4.sin_addr.s_addr)
691 				return addrw;
692 		} else if (addrw->a.sa.sa_family == AF_INET6) {
693 			if (ipv6_addr_equal(&addrw->a.v6.sin6_addr,
694 			    &addr->a.v6.sin6_addr))
695 				return addrw;
696 		}
697 	}
698 	return NULL;
699 }
700 
701 void sctp_addr_wq_mgmt(struct net *net, struct sctp_sockaddr_entry *addr, int cmd)
702 {
703 	struct sctp_sockaddr_entry *addrw;
704 	unsigned long timeo_val;
705 
706 	/* first, we check if an opposite message already exist in the queue.
707 	 * If we found such message, it is removed.
708 	 * This operation is a bit stupid, but the DHCP client attaches the
709 	 * new address after a couple of addition and deletion of that address
710 	 */
711 
712 	spin_lock_bh(&net->sctp.addr_wq_lock);
713 	/* Offsets existing events in addr_wq */
714 	addrw = sctp_addr_wq_lookup(net, addr);
715 	if (addrw) {
716 		if (addrw->state != cmd) {
717 			pr_debug("%s: offsets existing entry for %d, addr:%pISc "
718 				 "in wq:%p\n", __func__, addrw->state, &addrw->a.sa,
719 				 &net->sctp.addr_waitq);
720 
721 			list_del(&addrw->list);
722 			kfree(addrw);
723 		}
724 		spin_unlock_bh(&net->sctp.addr_wq_lock);
725 		return;
726 	}
727 
728 	/* OK, we have to add the new address to the wait queue */
729 	addrw = kmemdup(addr, sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
730 	if (addrw == NULL) {
731 		spin_unlock_bh(&net->sctp.addr_wq_lock);
732 		return;
733 	}
734 	addrw->state = cmd;
735 	list_add_tail(&addrw->list, &net->sctp.addr_waitq);
736 
737 	pr_debug("%s: add new entry for cmd:%d, addr:%pISc in wq:%p\n",
738 		 __func__, addrw->state, &addrw->a.sa, &net->sctp.addr_waitq);
739 
740 	if (!timer_pending(&net->sctp.addr_wq_timer)) {
741 		timeo_val = jiffies;
742 		timeo_val += msecs_to_jiffies(SCTP_ADDRESS_TICK_DELAY);
743 		mod_timer(&net->sctp.addr_wq_timer, timeo_val);
744 	}
745 	spin_unlock_bh(&net->sctp.addr_wq_lock);
746 }
747 
748 /* Event handler for inet address addition/deletion events.
749  * The sctp_local_addr_list needs to be protocted by a spin lock since
750  * multiple notifiers (say IPv4 and IPv6) may be running at the same
751  * time and thus corrupt the list.
752  * The reader side is protected with RCU.
753  */
754 static int sctp_inetaddr_event(struct notifier_block *this, unsigned long ev,
755 			       void *ptr)
756 {
757 	struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
758 	struct sctp_sockaddr_entry *addr = NULL;
759 	struct sctp_sockaddr_entry *temp;
760 	struct net *net = dev_net(ifa->ifa_dev->dev);
761 	int found = 0;
762 
763 	switch (ev) {
764 	case NETDEV_UP:
765 		addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
766 		if (addr) {
767 			addr->a.v4.sin_family = AF_INET;
768 			addr->a.v4.sin_addr.s_addr = ifa->ifa_local;
769 			addr->valid = 1;
770 			spin_lock_bh(&net->sctp.local_addr_lock);
771 			list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
772 			sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
773 			spin_unlock_bh(&net->sctp.local_addr_lock);
774 		}
775 		break;
776 	case NETDEV_DOWN:
777 		spin_lock_bh(&net->sctp.local_addr_lock);
778 		list_for_each_entry_safe(addr, temp,
779 					&net->sctp.local_addr_list, list) {
780 			if (addr->a.sa.sa_family == AF_INET &&
781 					addr->a.v4.sin_addr.s_addr ==
782 					ifa->ifa_local) {
783 				sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
784 				found = 1;
785 				addr->valid = 0;
786 				list_del_rcu(&addr->list);
787 				break;
788 			}
789 		}
790 		spin_unlock_bh(&net->sctp.local_addr_lock);
791 		if (found)
792 			kfree_rcu(addr, rcu);
793 		break;
794 	}
795 
796 	return NOTIFY_DONE;
797 }
798 
799 /*
800  * Initialize the control inode/socket with a control endpoint data
801  * structure.  This endpoint is reserved exclusively for the OOTB processing.
802  */
803 static int sctp_ctl_sock_init(struct net *net)
804 {
805 	int err;
806 	sa_family_t family = PF_INET;
807 
808 	if (sctp_get_pf_specific(PF_INET6))
809 		family = PF_INET6;
810 
811 	err = inet_ctl_sock_create(&net->sctp.ctl_sock, family,
812 				   SOCK_SEQPACKET, IPPROTO_SCTP, net);
813 
814 	/* If IPv6 socket could not be created, try the IPv4 socket */
815 	if (err < 0 && family == PF_INET6)
816 		err = inet_ctl_sock_create(&net->sctp.ctl_sock, AF_INET,
817 					   SOCK_SEQPACKET, IPPROTO_SCTP,
818 					   net);
819 
820 	if (err < 0) {
821 		pr_err("Failed to create the SCTP control socket\n");
822 		return err;
823 	}
824 	return 0;
825 }
826 
827 /* Register address family specific functions. */
828 int sctp_register_af(struct sctp_af *af)
829 {
830 	switch (af->sa_family) {
831 	case AF_INET:
832 		if (sctp_af_v4_specific)
833 			return 0;
834 		sctp_af_v4_specific = af;
835 		break;
836 	case AF_INET6:
837 		if (sctp_af_v6_specific)
838 			return 0;
839 		sctp_af_v6_specific = af;
840 		break;
841 	default:
842 		return 0;
843 	}
844 
845 	INIT_LIST_HEAD(&af->list);
846 	list_add_tail(&af->list, &sctp_address_families);
847 	return 1;
848 }
849 
850 /* Get the table of functions for manipulating a particular address
851  * family.
852  */
853 struct sctp_af *sctp_get_af_specific(sa_family_t family)
854 {
855 	switch (family) {
856 	case AF_INET:
857 		return sctp_af_v4_specific;
858 	case AF_INET6:
859 		return sctp_af_v6_specific;
860 	default:
861 		return NULL;
862 	}
863 }
864 
865 /* Common code to initialize a AF_INET msg_name. */
866 static void sctp_inet_msgname(char *msgname, int *addr_len)
867 {
868 	struct sockaddr_in *sin;
869 
870 	sin = (struct sockaddr_in *)msgname;
871 	*addr_len = sizeof(struct sockaddr_in);
872 	sin->sin_family = AF_INET;
873 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
874 }
875 
876 /* Copy the primary address of the peer primary address as the msg_name. */
877 static void sctp_inet_event_msgname(struct sctp_ulpevent *event, char *msgname,
878 				    int *addr_len)
879 {
880 	struct sockaddr_in *sin, *sinfrom;
881 
882 	if (msgname) {
883 		struct sctp_association *asoc;
884 
885 		asoc = event->asoc;
886 		sctp_inet_msgname(msgname, addr_len);
887 		sin = (struct sockaddr_in *)msgname;
888 		sinfrom = &asoc->peer.primary_addr.v4;
889 		sin->sin_port = htons(asoc->peer.port);
890 		sin->sin_addr.s_addr = sinfrom->sin_addr.s_addr;
891 	}
892 }
893 
894 /* Initialize and copy out a msgname from an inbound skb. */
895 static void sctp_inet_skb_msgname(struct sk_buff *skb, char *msgname, int *len)
896 {
897 	if (msgname) {
898 		struct sctphdr *sh = sctp_hdr(skb);
899 		struct sockaddr_in *sin = (struct sockaddr_in *)msgname;
900 
901 		sctp_inet_msgname(msgname, len);
902 		sin->sin_port = sh->source;
903 		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
904 	}
905 }
906 
907 /* Do we support this AF? */
908 static int sctp_inet_af_supported(sa_family_t family, struct sctp_sock *sp)
909 {
910 	/* PF_INET only supports AF_INET addresses. */
911 	return AF_INET == family;
912 }
913 
914 /* Address matching with wildcards allowed. */
915 static int sctp_inet_cmp_addr(const union sctp_addr *addr1,
916 			      const union sctp_addr *addr2,
917 			      struct sctp_sock *opt)
918 {
919 	/* PF_INET only supports AF_INET addresses. */
920 	if (addr1->sa.sa_family != addr2->sa.sa_family)
921 		return 0;
922 	if (htonl(INADDR_ANY) == addr1->v4.sin_addr.s_addr ||
923 	    htonl(INADDR_ANY) == addr2->v4.sin_addr.s_addr)
924 		return 1;
925 	if (addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr)
926 		return 1;
927 
928 	return 0;
929 }
930 
931 /* Verify that provided sockaddr looks bindable.  Common verification has
932  * already been taken care of.
933  */
934 static int sctp_inet_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
935 {
936 	return sctp_v4_available(addr, opt);
937 }
938 
939 /* Verify that sockaddr looks sendable.  Common verification has already
940  * been taken care of.
941  */
942 static int sctp_inet_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
943 {
944 	return 1;
945 }
946 
947 /* Fill in Supported Address Type information for INIT and INIT-ACK
948  * chunks.  Returns number of addresses supported.
949  */
950 static int sctp_inet_supported_addrs(const struct sctp_sock *opt,
951 				     __be16 *types)
952 {
953 	types[0] = SCTP_PARAM_IPV4_ADDRESS;
954 	return 1;
955 }
956 
957 /* Wrapper routine that calls the ip transmit routine. */
958 static inline int sctp_v4_xmit(struct sk_buff *skb,
959 			       struct sctp_transport *transport)
960 {
961 	struct inet_sock *inet = inet_sk(skb->sk);
962 	__u8 dscp = inet->tos;
963 
964 	pr_debug("%s: skb:%p, len:%d, src:%pI4, dst:%pI4\n", __func__, skb,
965 		 skb->len, &transport->fl.u.ip4.saddr,
966 		 &transport->fl.u.ip4.daddr);
967 
968 	if (transport->dscp & SCTP_DSCP_SET_MASK)
969 		dscp = transport->dscp & SCTP_DSCP_VAL_MASK;
970 
971 	inet->pmtudisc = transport->param_flags & SPP_PMTUD_ENABLE ?
972 			 IP_PMTUDISC_DO : IP_PMTUDISC_DONT;
973 
974 	SCTP_INC_STATS(sock_net(&inet->sk), SCTP_MIB_OUTSCTPPACKS);
975 
976 	return __ip_queue_xmit(&inet->sk, skb, &transport->fl, dscp);
977 }
978 
979 static struct sctp_af sctp_af_inet;
980 
981 static struct sctp_pf sctp_pf_inet = {
982 	.event_msgname = sctp_inet_event_msgname,
983 	.skb_msgname   = sctp_inet_skb_msgname,
984 	.af_supported  = sctp_inet_af_supported,
985 	.cmp_addr      = sctp_inet_cmp_addr,
986 	.bind_verify   = sctp_inet_bind_verify,
987 	.send_verify   = sctp_inet_send_verify,
988 	.supported_addrs = sctp_inet_supported_addrs,
989 	.create_accept_sk = sctp_v4_create_accept_sk,
990 	.addr_to_user  = sctp_v4_addr_to_user,
991 	.to_sk_saddr   = sctp_v4_to_sk_saddr,
992 	.to_sk_daddr   = sctp_v4_to_sk_daddr,
993 	.copy_ip_options = sctp_v4_copy_ip_options,
994 	.af            = &sctp_af_inet
995 };
996 
997 /* Notifier for inetaddr addition/deletion events.  */
998 static struct notifier_block sctp_inetaddr_notifier = {
999 	.notifier_call = sctp_inetaddr_event,
1000 };
1001 
1002 /* Socket operations.  */
1003 static const struct proto_ops inet_seqpacket_ops = {
1004 	.family		   = PF_INET,
1005 	.owner		   = THIS_MODULE,
1006 	.release	   = inet_release,	/* Needs to be wrapped... */
1007 	.bind		   = inet_bind,
1008 	.connect	   = sctp_inet_connect,
1009 	.socketpair	   = sock_no_socketpair,
1010 	.accept		   = inet_accept,
1011 	.getname	   = inet_getname,	/* Semantics are different.  */
1012 	.poll		   = sctp_poll,
1013 	.ioctl		   = inet_ioctl,
1014 	.gettstamp	   = sock_gettstamp,
1015 	.listen		   = sctp_inet_listen,
1016 	.shutdown	   = inet_shutdown,	/* Looks harmless.  */
1017 	.setsockopt	   = sock_common_setsockopt, /* IP_SOL IP_OPTION is a problem */
1018 	.getsockopt	   = sock_common_getsockopt,
1019 	.sendmsg	   = inet_sendmsg,
1020 	.recvmsg	   = inet_recvmsg,
1021 	.mmap		   = sock_no_mmap,
1022 	.sendpage	   = sock_no_sendpage,
1023 #ifdef CONFIG_COMPAT
1024 	.compat_setsockopt = compat_sock_common_setsockopt,
1025 	.compat_getsockopt = compat_sock_common_getsockopt,
1026 #endif
1027 };
1028 
1029 /* Registration with AF_INET family.  */
1030 static struct inet_protosw sctp_seqpacket_protosw = {
1031 	.type       = SOCK_SEQPACKET,
1032 	.protocol   = IPPROTO_SCTP,
1033 	.prot       = &sctp_prot,
1034 	.ops        = &inet_seqpacket_ops,
1035 	.flags      = SCTP_PROTOSW_FLAG
1036 };
1037 static struct inet_protosw sctp_stream_protosw = {
1038 	.type       = SOCK_STREAM,
1039 	.protocol   = IPPROTO_SCTP,
1040 	.prot       = &sctp_prot,
1041 	.ops        = &inet_seqpacket_ops,
1042 	.flags      = SCTP_PROTOSW_FLAG
1043 };
1044 
1045 /* Register with IP layer.  */
1046 static const struct net_protocol sctp_protocol = {
1047 	.handler     = sctp_rcv,
1048 	.err_handler = sctp_v4_err,
1049 	.no_policy   = 1,
1050 	.netns_ok    = 1,
1051 	.icmp_strict_tag_validation = 1,
1052 };
1053 
1054 /* IPv4 address related functions.  */
1055 static struct sctp_af sctp_af_inet = {
1056 	.sa_family	   = AF_INET,
1057 	.sctp_xmit	   = sctp_v4_xmit,
1058 	.setsockopt	   = ip_setsockopt,
1059 	.getsockopt	   = ip_getsockopt,
1060 	.get_dst	   = sctp_v4_get_dst,
1061 	.get_saddr	   = sctp_v4_get_saddr,
1062 	.copy_addrlist	   = sctp_v4_copy_addrlist,
1063 	.from_skb	   = sctp_v4_from_skb,
1064 	.from_sk	   = sctp_v4_from_sk,
1065 	.from_addr_param   = sctp_v4_from_addr_param,
1066 	.to_addr_param	   = sctp_v4_to_addr_param,
1067 	.cmp_addr	   = sctp_v4_cmp_addr,
1068 	.addr_valid	   = sctp_v4_addr_valid,
1069 	.inaddr_any	   = sctp_v4_inaddr_any,
1070 	.is_any		   = sctp_v4_is_any,
1071 	.available	   = sctp_v4_available,
1072 	.scope		   = sctp_v4_scope,
1073 	.skb_iif	   = sctp_v4_skb_iif,
1074 	.is_ce		   = sctp_v4_is_ce,
1075 	.seq_dump_addr	   = sctp_v4_seq_dump_addr,
1076 	.ecn_capable	   = sctp_v4_ecn_capable,
1077 	.net_header_len	   = sizeof(struct iphdr),
1078 	.sockaddr_len	   = sizeof(struct sockaddr_in),
1079 	.ip_options_len	   = sctp_v4_ip_options_len,
1080 #ifdef CONFIG_COMPAT
1081 	.compat_setsockopt = compat_ip_setsockopt,
1082 	.compat_getsockopt = compat_ip_getsockopt,
1083 #endif
1084 };
1085 
1086 struct sctp_pf *sctp_get_pf_specific(sa_family_t family)
1087 {
1088 	switch (family) {
1089 	case PF_INET:
1090 		return sctp_pf_inet_specific;
1091 	case PF_INET6:
1092 		return sctp_pf_inet6_specific;
1093 	default:
1094 		return NULL;
1095 	}
1096 }
1097 
1098 /* Register the PF specific function table.  */
1099 int sctp_register_pf(struct sctp_pf *pf, sa_family_t family)
1100 {
1101 	switch (family) {
1102 	case PF_INET:
1103 		if (sctp_pf_inet_specific)
1104 			return 0;
1105 		sctp_pf_inet_specific = pf;
1106 		break;
1107 	case PF_INET6:
1108 		if (sctp_pf_inet6_specific)
1109 			return 0;
1110 		sctp_pf_inet6_specific = pf;
1111 		break;
1112 	default:
1113 		return 0;
1114 	}
1115 	return 1;
1116 }
1117 
1118 static inline int init_sctp_mibs(struct net *net)
1119 {
1120 	net->sctp.sctp_statistics = alloc_percpu(struct sctp_mib);
1121 	if (!net->sctp.sctp_statistics)
1122 		return -ENOMEM;
1123 	return 0;
1124 }
1125 
1126 static inline void cleanup_sctp_mibs(struct net *net)
1127 {
1128 	free_percpu(net->sctp.sctp_statistics);
1129 }
1130 
1131 static void sctp_v4_pf_init(void)
1132 {
1133 	/* Initialize the SCTP specific PF functions. */
1134 	sctp_register_pf(&sctp_pf_inet, PF_INET);
1135 	sctp_register_af(&sctp_af_inet);
1136 }
1137 
1138 static void sctp_v4_pf_exit(void)
1139 {
1140 	list_del(&sctp_af_inet.list);
1141 }
1142 
1143 static int sctp_v4_protosw_init(void)
1144 {
1145 	int rc;
1146 
1147 	rc = proto_register(&sctp_prot, 1);
1148 	if (rc)
1149 		return rc;
1150 
1151 	/* Register SCTP(UDP and TCP style) with socket layer.  */
1152 	inet_register_protosw(&sctp_seqpacket_protosw);
1153 	inet_register_protosw(&sctp_stream_protosw);
1154 
1155 	return 0;
1156 }
1157 
1158 static void sctp_v4_protosw_exit(void)
1159 {
1160 	inet_unregister_protosw(&sctp_stream_protosw);
1161 	inet_unregister_protosw(&sctp_seqpacket_protosw);
1162 	proto_unregister(&sctp_prot);
1163 }
1164 
1165 static int sctp_v4_add_protocol(void)
1166 {
1167 	/* Register notifier for inet address additions/deletions. */
1168 	register_inetaddr_notifier(&sctp_inetaddr_notifier);
1169 
1170 	/* Register SCTP with inet layer.  */
1171 	if (inet_add_protocol(&sctp_protocol, IPPROTO_SCTP) < 0)
1172 		return -EAGAIN;
1173 
1174 	return 0;
1175 }
1176 
1177 static void sctp_v4_del_protocol(void)
1178 {
1179 	inet_del_protocol(&sctp_protocol, IPPROTO_SCTP);
1180 	unregister_inetaddr_notifier(&sctp_inetaddr_notifier);
1181 }
1182 
1183 static int __net_init sctp_defaults_init(struct net *net)
1184 {
1185 	int status;
1186 
1187 	/*
1188 	 * 14. Suggested SCTP Protocol Parameter Values
1189 	 */
1190 	/* The following protocol parameters are RECOMMENDED:  */
1191 	/* RTO.Initial              - 3  seconds */
1192 	net->sctp.rto_initial			= SCTP_RTO_INITIAL;
1193 	/* RTO.Min                  - 1  second */
1194 	net->sctp.rto_min	 		= SCTP_RTO_MIN;
1195 	/* RTO.Max                 -  60 seconds */
1196 	net->sctp.rto_max 			= SCTP_RTO_MAX;
1197 	/* RTO.Alpha                - 1/8 */
1198 	net->sctp.rto_alpha			= SCTP_RTO_ALPHA;
1199 	/* RTO.Beta                 - 1/4 */
1200 	net->sctp.rto_beta			= SCTP_RTO_BETA;
1201 
1202 	/* Valid.Cookie.Life        - 60  seconds */
1203 	net->sctp.valid_cookie_life		= SCTP_DEFAULT_COOKIE_LIFE;
1204 
1205 	/* Whether Cookie Preservative is enabled(1) or not(0) */
1206 	net->sctp.cookie_preserve_enable 	= 1;
1207 
1208 	/* Default sctp sockets to use md5 as their hmac alg */
1209 #if defined (CONFIG_SCTP_DEFAULT_COOKIE_HMAC_MD5)
1210 	net->sctp.sctp_hmac_alg			= "md5";
1211 #elif defined (CONFIG_SCTP_DEFAULT_COOKIE_HMAC_SHA1)
1212 	net->sctp.sctp_hmac_alg			= "sha1";
1213 #else
1214 	net->sctp.sctp_hmac_alg			= NULL;
1215 #endif
1216 
1217 	/* Max.Burst		    - 4 */
1218 	net->sctp.max_burst			= SCTP_DEFAULT_MAX_BURST;
1219 
1220 	/* Disable of Primary Path Switchover by default */
1221 	net->sctp.ps_retrans = SCTP_PS_RETRANS_MAX;
1222 
1223 	/* Enable pf state by default */
1224 	net->sctp.pf_enable = 1;
1225 
1226 	/* Ignore pf exposure feature by default */
1227 	net->sctp.pf_expose = SCTP_PF_EXPOSE_UNSET;
1228 
1229 	/* Association.Max.Retrans  - 10 attempts
1230 	 * Path.Max.Retrans         - 5  attempts (per destination address)
1231 	 * Max.Init.Retransmits     - 8  attempts
1232 	 */
1233 	net->sctp.max_retrans_association	= 10;
1234 	net->sctp.max_retrans_path		= 5;
1235 	net->sctp.max_retrans_init		= 8;
1236 
1237 	/* Sendbuffer growth	    - do per-socket accounting */
1238 	net->sctp.sndbuf_policy			= 0;
1239 
1240 	/* Rcvbuffer growth	    - do per-socket accounting */
1241 	net->sctp.rcvbuf_policy			= 0;
1242 
1243 	/* HB.interval              - 30 seconds */
1244 	net->sctp.hb_interval			= SCTP_DEFAULT_TIMEOUT_HEARTBEAT;
1245 
1246 	/* delayed SACK timeout */
1247 	net->sctp.sack_timeout			= SCTP_DEFAULT_TIMEOUT_SACK;
1248 
1249 	/* Disable ADDIP by default. */
1250 	net->sctp.addip_enable = 0;
1251 	net->sctp.addip_noauth = 0;
1252 	net->sctp.default_auto_asconf = 0;
1253 
1254 	/* Enable PR-SCTP by default. */
1255 	net->sctp.prsctp_enable = 1;
1256 
1257 	/* Disable RECONF by default. */
1258 	net->sctp.reconf_enable = 0;
1259 
1260 	/* Disable AUTH by default. */
1261 	net->sctp.auth_enable = 0;
1262 
1263 	/* Enable ECN by default. */
1264 	net->sctp.ecn_enable = 1;
1265 
1266 	/* Set SCOPE policy to enabled */
1267 	net->sctp.scope_policy = SCTP_SCOPE_POLICY_ENABLE;
1268 
1269 	/* Set the default rwnd update threshold */
1270 	net->sctp.rwnd_upd_shift = SCTP_DEFAULT_RWND_SHIFT;
1271 
1272 	/* Initialize maximum autoclose timeout. */
1273 	net->sctp.max_autoclose		= INT_MAX / HZ;
1274 
1275 	status = sctp_sysctl_net_register(net);
1276 	if (status)
1277 		goto err_sysctl_register;
1278 
1279 	/* Allocate and initialise sctp mibs.  */
1280 	status = init_sctp_mibs(net);
1281 	if (status)
1282 		goto err_init_mibs;
1283 
1284 #ifdef CONFIG_PROC_FS
1285 	/* Initialize proc fs directory.  */
1286 	status = sctp_proc_init(net);
1287 	if (status)
1288 		goto err_init_proc;
1289 #endif
1290 
1291 	sctp_dbg_objcnt_init(net);
1292 
1293 	/* Initialize the local address list. */
1294 	INIT_LIST_HEAD(&net->sctp.local_addr_list);
1295 	spin_lock_init(&net->sctp.local_addr_lock);
1296 	sctp_get_local_addr_list(net);
1297 
1298 	/* Initialize the address event list */
1299 	INIT_LIST_HEAD(&net->sctp.addr_waitq);
1300 	INIT_LIST_HEAD(&net->sctp.auto_asconf_splist);
1301 	spin_lock_init(&net->sctp.addr_wq_lock);
1302 	net->sctp.addr_wq_timer.expires = 0;
1303 	timer_setup(&net->sctp.addr_wq_timer, sctp_addr_wq_timeout_handler, 0);
1304 
1305 	return 0;
1306 
1307 #ifdef CONFIG_PROC_FS
1308 err_init_proc:
1309 	cleanup_sctp_mibs(net);
1310 #endif
1311 err_init_mibs:
1312 	sctp_sysctl_net_unregister(net);
1313 err_sysctl_register:
1314 	return status;
1315 }
1316 
1317 static void __net_exit sctp_defaults_exit(struct net *net)
1318 {
1319 	/* Free the local address list */
1320 	sctp_free_addr_wq(net);
1321 	sctp_free_local_addr_list(net);
1322 
1323 #ifdef CONFIG_PROC_FS
1324 	remove_proc_subtree("sctp", net->proc_net);
1325 	net->sctp.proc_net_sctp = NULL;
1326 #endif
1327 	cleanup_sctp_mibs(net);
1328 	sctp_sysctl_net_unregister(net);
1329 }
1330 
1331 static struct pernet_operations sctp_defaults_ops = {
1332 	.init = sctp_defaults_init,
1333 	.exit = sctp_defaults_exit,
1334 };
1335 
1336 static int __net_init sctp_ctrlsock_init(struct net *net)
1337 {
1338 	int status;
1339 
1340 	/* Initialize the control inode/socket for handling OOTB packets.  */
1341 	status = sctp_ctl_sock_init(net);
1342 	if (status)
1343 		pr_err("Failed to initialize the SCTP control sock\n");
1344 
1345 	return status;
1346 }
1347 
1348 static void __net_exit sctp_ctrlsock_exit(struct net *net)
1349 {
1350 	/* Free the control endpoint.  */
1351 	inet_ctl_sock_destroy(net->sctp.ctl_sock);
1352 }
1353 
1354 static struct pernet_operations sctp_ctrlsock_ops = {
1355 	.init = sctp_ctrlsock_init,
1356 	.exit = sctp_ctrlsock_exit,
1357 };
1358 
1359 /* Initialize the universe into something sensible.  */
1360 static __init int sctp_init(void)
1361 {
1362 	int i;
1363 	int status = -EINVAL;
1364 	unsigned long goal;
1365 	unsigned long limit;
1366 	unsigned long nr_pages = totalram_pages();
1367 	int max_share;
1368 	int order;
1369 	int num_entries;
1370 	int max_entry_order;
1371 
1372 	sock_skb_cb_check_size(sizeof(struct sctp_ulpevent));
1373 
1374 	/* Allocate bind_bucket and chunk caches. */
1375 	status = -ENOBUFS;
1376 	sctp_bucket_cachep = kmem_cache_create("sctp_bind_bucket",
1377 					       sizeof(struct sctp_bind_bucket),
1378 					       0, SLAB_HWCACHE_ALIGN,
1379 					       NULL);
1380 	if (!sctp_bucket_cachep)
1381 		goto out;
1382 
1383 	sctp_chunk_cachep = kmem_cache_create("sctp_chunk",
1384 					       sizeof(struct sctp_chunk),
1385 					       0, SLAB_HWCACHE_ALIGN,
1386 					       NULL);
1387 	if (!sctp_chunk_cachep)
1388 		goto err_chunk_cachep;
1389 
1390 	status = percpu_counter_init(&sctp_sockets_allocated, 0, GFP_KERNEL);
1391 	if (status)
1392 		goto err_percpu_counter_init;
1393 
1394 	/* Implementation specific variables. */
1395 
1396 	/* Initialize default stream count setup information. */
1397 	sctp_max_instreams    		= SCTP_DEFAULT_INSTREAMS;
1398 	sctp_max_outstreams   		= SCTP_DEFAULT_OUTSTREAMS;
1399 
1400 	/* Initialize handle used for association ids. */
1401 	idr_init(&sctp_assocs_id);
1402 
1403 	limit = nr_free_buffer_pages() / 8;
1404 	limit = max(limit, 128UL);
1405 	sysctl_sctp_mem[0] = limit / 4 * 3;
1406 	sysctl_sctp_mem[1] = limit;
1407 	sysctl_sctp_mem[2] = sysctl_sctp_mem[0] * 2;
1408 
1409 	/* Set per-socket limits to no more than 1/128 the pressure threshold*/
1410 	limit = (sysctl_sctp_mem[1]) << (PAGE_SHIFT - 7);
1411 	max_share = min(4UL*1024*1024, limit);
1412 
1413 	sysctl_sctp_rmem[0] = SK_MEM_QUANTUM; /* give each asoc 1 page min */
1414 	sysctl_sctp_rmem[1] = 1500 * SKB_TRUESIZE(1);
1415 	sysctl_sctp_rmem[2] = max(sysctl_sctp_rmem[1], max_share);
1416 
1417 	sysctl_sctp_wmem[0] = SK_MEM_QUANTUM;
1418 	sysctl_sctp_wmem[1] = 16*1024;
1419 	sysctl_sctp_wmem[2] = max(64*1024, max_share);
1420 
1421 	/* Size and allocate the association hash table.
1422 	 * The methodology is similar to that of the tcp hash tables.
1423 	 * Though not identical.  Start by getting a goal size
1424 	 */
1425 	if (nr_pages >= (128 * 1024))
1426 		goal = nr_pages >> (22 - PAGE_SHIFT);
1427 	else
1428 		goal = nr_pages >> (24 - PAGE_SHIFT);
1429 
1430 	/* Then compute the page order for said goal */
1431 	order = get_order(goal);
1432 
1433 	/* Now compute the required page order for the maximum sized table we
1434 	 * want to create
1435 	 */
1436 	max_entry_order = get_order(MAX_SCTP_PORT_HASH_ENTRIES *
1437 				    sizeof(struct sctp_bind_hashbucket));
1438 
1439 	/* Limit the page order by that maximum hash table size */
1440 	order = min(order, max_entry_order);
1441 
1442 	/* Allocate and initialize the endpoint hash table.  */
1443 	sctp_ep_hashsize = 64;
1444 	sctp_ep_hashtable =
1445 		kmalloc_array(64, sizeof(struct sctp_hashbucket), GFP_KERNEL);
1446 	if (!sctp_ep_hashtable) {
1447 		pr_err("Failed endpoint_hash alloc\n");
1448 		status = -ENOMEM;
1449 		goto err_ehash_alloc;
1450 	}
1451 	for (i = 0; i < sctp_ep_hashsize; i++) {
1452 		rwlock_init(&sctp_ep_hashtable[i].lock);
1453 		INIT_HLIST_HEAD(&sctp_ep_hashtable[i].chain);
1454 	}
1455 
1456 	/* Allocate and initialize the SCTP port hash table.
1457 	 * Note that order is initalized to start at the max sized
1458 	 * table we want to support.  If we can't get that many pages
1459 	 * reduce the order and try again
1460 	 */
1461 	do {
1462 		sctp_port_hashtable = (struct sctp_bind_hashbucket *)
1463 			__get_free_pages(GFP_KERNEL | __GFP_NOWARN, order);
1464 	} while (!sctp_port_hashtable && --order > 0);
1465 
1466 	if (!sctp_port_hashtable) {
1467 		pr_err("Failed bind hash alloc\n");
1468 		status = -ENOMEM;
1469 		goto err_bhash_alloc;
1470 	}
1471 
1472 	/* Now compute the number of entries that will fit in the
1473 	 * port hash space we allocated
1474 	 */
1475 	num_entries = (1UL << order) * PAGE_SIZE /
1476 		      sizeof(struct sctp_bind_hashbucket);
1477 
1478 	/* And finish by rounding it down to the nearest power of two
1479 	 * this wastes some memory of course, but its needed because
1480 	 * the hash function operates based on the assumption that
1481 	 * that the number of entries is a power of two
1482 	 */
1483 	sctp_port_hashsize = rounddown_pow_of_two(num_entries);
1484 
1485 	for (i = 0; i < sctp_port_hashsize; i++) {
1486 		spin_lock_init(&sctp_port_hashtable[i].lock);
1487 		INIT_HLIST_HEAD(&sctp_port_hashtable[i].chain);
1488 	}
1489 
1490 	status = sctp_transport_hashtable_init();
1491 	if (status)
1492 		goto err_thash_alloc;
1493 
1494 	pr_info("Hash tables configured (bind %d/%d)\n", sctp_port_hashsize,
1495 		num_entries);
1496 
1497 	sctp_sysctl_register();
1498 
1499 	INIT_LIST_HEAD(&sctp_address_families);
1500 	sctp_v4_pf_init();
1501 	sctp_v6_pf_init();
1502 	sctp_sched_ops_init();
1503 
1504 	status = register_pernet_subsys(&sctp_defaults_ops);
1505 	if (status)
1506 		goto err_register_defaults;
1507 
1508 	status = sctp_v4_protosw_init();
1509 	if (status)
1510 		goto err_protosw_init;
1511 
1512 	status = sctp_v6_protosw_init();
1513 	if (status)
1514 		goto err_v6_protosw_init;
1515 
1516 	status = register_pernet_subsys(&sctp_ctrlsock_ops);
1517 	if (status)
1518 		goto err_register_ctrlsock;
1519 
1520 	status = sctp_v4_add_protocol();
1521 	if (status)
1522 		goto err_add_protocol;
1523 
1524 	/* Register SCTP with inet6 layer.  */
1525 	status = sctp_v6_add_protocol();
1526 	if (status)
1527 		goto err_v6_add_protocol;
1528 
1529 	if (sctp_offload_init() < 0)
1530 		pr_crit("%s: Cannot add SCTP protocol offload\n", __func__);
1531 
1532 out:
1533 	return status;
1534 err_v6_add_protocol:
1535 	sctp_v4_del_protocol();
1536 err_add_protocol:
1537 	unregister_pernet_subsys(&sctp_ctrlsock_ops);
1538 err_register_ctrlsock:
1539 	sctp_v6_protosw_exit();
1540 err_v6_protosw_init:
1541 	sctp_v4_protosw_exit();
1542 err_protosw_init:
1543 	unregister_pernet_subsys(&sctp_defaults_ops);
1544 err_register_defaults:
1545 	sctp_v4_pf_exit();
1546 	sctp_v6_pf_exit();
1547 	sctp_sysctl_unregister();
1548 	free_pages((unsigned long)sctp_port_hashtable,
1549 		   get_order(sctp_port_hashsize *
1550 			     sizeof(struct sctp_bind_hashbucket)));
1551 err_bhash_alloc:
1552 	sctp_transport_hashtable_destroy();
1553 err_thash_alloc:
1554 	kfree(sctp_ep_hashtable);
1555 err_ehash_alloc:
1556 	percpu_counter_destroy(&sctp_sockets_allocated);
1557 err_percpu_counter_init:
1558 	kmem_cache_destroy(sctp_chunk_cachep);
1559 err_chunk_cachep:
1560 	kmem_cache_destroy(sctp_bucket_cachep);
1561 	goto out;
1562 }
1563 
1564 /* Exit handler for the SCTP protocol.  */
1565 static __exit void sctp_exit(void)
1566 {
1567 	/* BUG.  This should probably do something useful like clean
1568 	 * up all the remaining associations and all that memory.
1569 	 */
1570 
1571 	/* Unregister with inet6/inet layers. */
1572 	sctp_v6_del_protocol();
1573 	sctp_v4_del_protocol();
1574 
1575 	unregister_pernet_subsys(&sctp_ctrlsock_ops);
1576 
1577 	/* Free protosw registrations */
1578 	sctp_v6_protosw_exit();
1579 	sctp_v4_protosw_exit();
1580 
1581 	unregister_pernet_subsys(&sctp_defaults_ops);
1582 
1583 	/* Unregister with socket layer. */
1584 	sctp_v6_pf_exit();
1585 	sctp_v4_pf_exit();
1586 
1587 	sctp_sysctl_unregister();
1588 
1589 	free_pages((unsigned long)sctp_port_hashtable,
1590 		   get_order(sctp_port_hashsize *
1591 			     sizeof(struct sctp_bind_hashbucket)));
1592 	kfree(sctp_ep_hashtable);
1593 	sctp_transport_hashtable_destroy();
1594 
1595 	percpu_counter_destroy(&sctp_sockets_allocated);
1596 
1597 	rcu_barrier(); /* Wait for completion of call_rcu()'s */
1598 
1599 	kmem_cache_destroy(sctp_chunk_cachep);
1600 	kmem_cache_destroy(sctp_bucket_cachep);
1601 }
1602 
1603 module_init(sctp_init);
1604 module_exit(sctp_exit);
1605 
1606 /*
1607  * __stringify doesn't likes enums, so use IPPROTO_SCTP value (132) directly.
1608  */
1609 MODULE_ALIAS("net-pf-" __stringify(PF_INET) "-proto-132");
1610 MODULE_ALIAS("net-pf-" __stringify(PF_INET6) "-proto-132");
1611 MODULE_AUTHOR("Linux Kernel SCTP developers <linux-sctp@vger.kernel.org>");
1612 MODULE_DESCRIPTION("Support for the SCTP protocol (RFC2960)");
1613 module_param_named(no_checksums, sctp_checksum_disable, bool, 0644);
1614 MODULE_PARM_DESC(no_checksums, "Disable checksums computing and verification");
1615 MODULE_LICENSE("GPL");
1616