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1 /* SCTP kernel implementation
2  * (C) Copyright IBM Corp. 2001, 2004
3  * Copyright (c) 1999-2000 Cisco, Inc.
4  * Copyright (c) 1999-2001 Motorola, Inc.
5  * Copyright (c) 2001 Intel Corp.
6  * Copyright (c) 2001 Nokia, Inc.
7  * Copyright (c) 2001 La Monte H.P. Yarroll
8  *
9  * This file is part of the SCTP kernel implementation
10  *
11  * Initialization/cleanup for SCTP protocol support.
12  *
13  * This SCTP implementation is free software;
14  * you can redistribute it and/or modify it under the terms of
15  * the GNU General Public License as published by
16  * the Free Software Foundation; either version 2, or (at your option)
17  * any later version.
18  *
19  * This SCTP implementation is distributed in the hope that it
20  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
21  *                 ************************
22  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
23  * See the GNU General Public License for more details.
24  *
25  * You should have received a copy of the GNU General Public License
26  * along with GNU CC; see the file COPYING.  If not, see
27  * <http://www.gnu.org/licenses/>.
28  *
29  * Please send any bug reports or fixes you make to the
30  * email address(es):
31  *    lksctp developers <linux-sctp@vger.kernel.org>
32  *
33  * Written or modified by:
34  *    La Monte H.P. Yarroll <piggy@acm.org>
35  *    Karl Knutson <karl@athena.chicago.il.us>
36  *    Jon Grimm <jgrimm@us.ibm.com>
37  *    Sridhar Samudrala <sri@us.ibm.com>
38  *    Daisy Chang <daisyc@us.ibm.com>
39  *    Ardelle Fan <ardelle.fan@intel.com>
40  */
41 
42 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
43 
44 #include <linux/module.h>
45 #include <linux/init.h>
46 #include <linux/netdevice.h>
47 #include <linux/inetdevice.h>
48 #include <linux/seq_file.h>
49 #include <linux/bootmem.h>
50 #include <linux/highmem.h>
51 #include <linux/swap.h>
52 #include <linux/slab.h>
53 #include <net/net_namespace.h>
54 #include <net/protocol.h>
55 #include <net/ip.h>
56 #include <net/ipv6.h>
57 #include <net/route.h>
58 #include <net/sctp/sctp.h>
59 #include <net/addrconf.h>
60 #include <net/inet_common.h>
61 #include <net/inet_ecn.h>
62 
63 #define MAX_SCTP_PORT_HASH_ENTRIES (64 * 1024)
64 
65 /* Global data structures. */
66 struct sctp_globals sctp_globals __read_mostly;
67 
68 struct idr sctp_assocs_id;
69 DEFINE_SPINLOCK(sctp_assocs_id_lock);
70 
71 static struct sctp_pf *sctp_pf_inet6_specific;
72 static struct sctp_pf *sctp_pf_inet_specific;
73 static struct sctp_af *sctp_af_v4_specific;
74 static struct sctp_af *sctp_af_v6_specific;
75 
76 struct kmem_cache *sctp_chunk_cachep __read_mostly;
77 struct kmem_cache *sctp_bucket_cachep __read_mostly;
78 
79 long sysctl_sctp_mem[3];
80 int sysctl_sctp_rmem[3];
81 int sysctl_sctp_wmem[3];
82 
83 /* Set up the proc fs entry for the SCTP protocol. */
sctp_proc_init(struct net * net)84 static int __net_init sctp_proc_init(struct net *net)
85 {
86 #ifdef CONFIG_PROC_FS
87 	net->sctp.proc_net_sctp = proc_net_mkdir(net, "sctp", net->proc_net);
88 	if (!net->sctp.proc_net_sctp)
89 		goto out_proc_net_sctp;
90 	if (sctp_snmp_proc_init(net))
91 		goto out_snmp_proc_init;
92 	if (sctp_eps_proc_init(net))
93 		goto out_eps_proc_init;
94 	if (sctp_assocs_proc_init(net))
95 		goto out_assocs_proc_init;
96 	if (sctp_remaddr_proc_init(net))
97 		goto out_remaddr_proc_init;
98 
99 	return 0;
100 
101 out_remaddr_proc_init:
102 	sctp_assocs_proc_exit(net);
103 out_assocs_proc_init:
104 	sctp_eps_proc_exit(net);
105 out_eps_proc_init:
106 	sctp_snmp_proc_exit(net);
107 out_snmp_proc_init:
108 	remove_proc_entry("sctp", net->proc_net);
109 	net->sctp.proc_net_sctp = NULL;
110 out_proc_net_sctp:
111 	return -ENOMEM;
112 #endif /* CONFIG_PROC_FS */
113 	return 0;
114 }
115 
116 /* Clean up the proc fs entry for the SCTP protocol.
117  * Note: Do not make this __exit as it is used in the init error
118  * path.
119  */
sctp_proc_exit(struct net * net)120 static void sctp_proc_exit(struct net *net)
121 {
122 #ifdef CONFIG_PROC_FS
123 	sctp_snmp_proc_exit(net);
124 	sctp_eps_proc_exit(net);
125 	sctp_assocs_proc_exit(net);
126 	sctp_remaddr_proc_exit(net);
127 
128 	remove_proc_entry("sctp", net->proc_net);
129 	net->sctp.proc_net_sctp = NULL;
130 #endif
131 }
132 
133 /* Private helper to extract ipv4 address and stash them in
134  * the protocol structure.
135  */
sctp_v4_copy_addrlist(struct list_head * addrlist,struct net_device * dev)136 static void sctp_v4_copy_addrlist(struct list_head *addrlist,
137 				  struct net_device *dev)
138 {
139 	struct in_device *in_dev;
140 	struct in_ifaddr *ifa;
141 	struct sctp_sockaddr_entry *addr;
142 
143 	rcu_read_lock();
144 	if ((in_dev = __in_dev_get_rcu(dev)) == NULL) {
145 		rcu_read_unlock();
146 		return;
147 	}
148 
149 	for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) {
150 		/* Add the address to the local list.  */
151 		addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
152 		if (addr) {
153 			addr->a.v4.sin_family = AF_INET;
154 			addr->a.v4.sin_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  */
sctp_get_local_addr_list(struct net * net)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.  */
sctp_free_local_addr_list(struct net * net)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'.  */
sctp_copy_local_addr_list(struct net * net,struct sctp_bind_addr * bp,sctp_scope_t scope,gfp_t gfp,int copy_flags)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_ALLOWED) &&
214 			      (copy_flags & SCTP_ADDR4_PEERSUPP))) ||
215 			    (((AF_INET6 == addr->a.sa.sa_family) &&
216 			      (copy_flags & SCTP_ADDR6_ALLOWED) &&
217 			      (copy_flags & SCTP_ADDR6_PEERSUPP)))) {
218 				error = sctp_add_bind_addr(bp, &addr->a,
219 						    SCTP_ADDR_SRC, GFP_ATOMIC);
220 				if (error)
221 					goto end_copy;
222 			}
223 		}
224 	}
225 
226 end_copy:
227 	rcu_read_unlock();
228 	return error;
229 }
230 
231 /* Initialize a sctp_addr from in incoming skb.  */
sctp_v4_from_skb(union sctp_addr * addr,struct sk_buff * skb,int is_saddr)232 static void sctp_v4_from_skb(union sctp_addr *addr, struct sk_buff *skb,
233 			     int is_saddr)
234 {
235 	void *from;
236 	__be16 *port;
237 	struct sctphdr *sh;
238 
239 	port = &addr->v4.sin_port;
240 	addr->v4.sin_family = AF_INET;
241 
242 	sh = sctp_hdr(skb);
243 	if (is_saddr) {
244 		*port  = sh->source;
245 		from = &ip_hdr(skb)->saddr;
246 	} else {
247 		*port = sh->dest;
248 		from = &ip_hdr(skb)->daddr;
249 	}
250 	memcpy(&addr->v4.sin_addr.s_addr, from, sizeof(struct in_addr));
251 }
252 
253 /* Initialize an sctp_addr from a socket. */
sctp_v4_from_sk(union sctp_addr * addr,struct sock * sk)254 static void sctp_v4_from_sk(union sctp_addr *addr, struct sock *sk)
255 {
256 	addr->v4.sin_family = AF_INET;
257 	addr->v4.sin_port = 0;
258 	addr->v4.sin_addr.s_addr = inet_sk(sk)->inet_rcv_saddr;
259 	memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
260 }
261 
262 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
sctp_v4_to_sk_saddr(union sctp_addr * addr,struct sock * sk)263 static void sctp_v4_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
264 {
265 	inet_sk(sk)->inet_rcv_saddr = addr->v4.sin_addr.s_addr;
266 }
267 
268 /* Initialize sk->sk_daddr from sctp_addr. */
sctp_v4_to_sk_daddr(union sctp_addr * addr,struct sock * sk)269 static void sctp_v4_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
270 {
271 	inet_sk(sk)->inet_daddr = addr->v4.sin_addr.s_addr;
272 }
273 
274 /* Initialize a sctp_addr from an address parameter. */
sctp_v4_from_addr_param(union sctp_addr * addr,union sctp_addr_param * param,__be16 port,int iif)275 static bool sctp_v4_from_addr_param(union sctp_addr *addr,
276 				    union sctp_addr_param *param,
277 				    __be16 port, int iif)
278 {
279 	if (ntohs(param->v4.param_hdr.length) < sizeof(struct sctp_ipv4addr_param))
280 		return false;
281 
282 	addr->v4.sin_family = AF_INET;
283 	addr->v4.sin_port = port;
284 	addr->v4.sin_addr.s_addr = param->v4.addr.s_addr;
285 	memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
286 
287 	return true;
288 }
289 
290 /* Initialize an address parameter from a sctp_addr and return the length
291  * of the address parameter.
292  */
sctp_v4_to_addr_param(const union sctp_addr * addr,union sctp_addr_param * param)293 static int sctp_v4_to_addr_param(const union sctp_addr *addr,
294 				 union sctp_addr_param *param)
295 {
296 	int length = sizeof(sctp_ipv4addr_param_t);
297 
298 	param->v4.param_hdr.type = SCTP_PARAM_IPV4_ADDRESS;
299 	param->v4.param_hdr.length = htons(length);
300 	param->v4.addr.s_addr = addr->v4.sin_addr.s_addr;
301 
302 	return length;
303 }
304 
305 /* Initialize a sctp_addr from a dst_entry. */
sctp_v4_dst_saddr(union sctp_addr * saddr,struct flowi4 * fl4,__be16 port)306 static void sctp_v4_dst_saddr(union sctp_addr *saddr, struct flowi4 *fl4,
307 			      __be16 port)
308 {
309 	saddr->v4.sin_family = AF_INET;
310 	saddr->v4.sin_port = port;
311 	saddr->v4.sin_addr.s_addr = fl4->saddr;
312 	memset(saddr->v4.sin_zero, 0, sizeof(saddr->v4.sin_zero));
313 }
314 
315 /* Compare two addresses exactly. */
sctp_v4_cmp_addr(const union sctp_addr * addr1,const union sctp_addr * addr2)316 static int sctp_v4_cmp_addr(const union sctp_addr *addr1,
317 			    const union sctp_addr *addr2)
318 {
319 	if (addr1->sa.sa_family != addr2->sa.sa_family)
320 		return 0;
321 	if (addr1->v4.sin_port != addr2->v4.sin_port)
322 		return 0;
323 	if (addr1->v4.sin_addr.s_addr != addr2->v4.sin_addr.s_addr)
324 		return 0;
325 
326 	return 1;
327 }
328 
329 /* Initialize addr struct to INADDR_ANY. */
sctp_v4_inaddr_any(union sctp_addr * addr,__be16 port)330 static void sctp_v4_inaddr_any(union sctp_addr *addr, __be16 port)
331 {
332 	addr->v4.sin_family = AF_INET;
333 	addr->v4.sin_addr.s_addr = htonl(INADDR_ANY);
334 	addr->v4.sin_port = port;
335 	memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
336 }
337 
338 /* Is this a wildcard address? */
sctp_v4_is_any(const union sctp_addr * addr)339 static int sctp_v4_is_any(const union sctp_addr *addr)
340 {
341 	return htonl(INADDR_ANY) == addr->v4.sin_addr.s_addr;
342 }
343 
344 /* This function checks if the address is a valid address to be used for
345  * SCTP binding.
346  *
347  * Output:
348  * Return 0 - If the address is a non-unicast or an illegal address.
349  * Return 1 - If the address is a unicast.
350  */
sctp_v4_addr_valid(union sctp_addr * addr,struct sctp_sock * sp,const struct sk_buff * skb)351 static int sctp_v4_addr_valid(union sctp_addr *addr,
352 			      struct sctp_sock *sp,
353 			      const struct sk_buff *skb)
354 {
355 	/* IPv4 addresses not allowed */
356 	if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
357 		return 0;
358 
359 	/* Is this a non-unicast address or a unusable SCTP address? */
360 	if (IS_IPV4_UNUSABLE_ADDRESS(addr->v4.sin_addr.s_addr))
361 		return 0;
362 
363 	/* Is this a broadcast address? */
364 	if (skb && skb_rtable(skb)->rt_flags & RTCF_BROADCAST)
365 		return 0;
366 
367 	return 1;
368 }
369 
370 /* Should this be available for binding?   */
sctp_v4_available(union sctp_addr * addr,struct sctp_sock * sp)371 static int sctp_v4_available(union sctp_addr *addr, struct sctp_sock *sp)
372 {
373 	struct net *net = sock_net(&sp->inet.sk);
374 	int ret = inet_addr_type(net, addr->v4.sin_addr.s_addr);
375 
376 
377 	if (addr->v4.sin_addr.s_addr != htonl(INADDR_ANY) &&
378 	   ret != RTN_LOCAL &&
379 	   !sp->inet.freebind &&
380 	   !net->ipv4.sysctl_ip_nonlocal_bind)
381 		return 0;
382 
383 	if (ipv6_only_sock(sctp_opt2sk(sp)))
384 		return 0;
385 
386 	return 1;
387 }
388 
389 /* Checking the loopback, private and other address scopes as defined in
390  * RFC 1918.   The IPv4 scoping is based on the draft for SCTP IPv4
391  * scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>.
392  *
393  * Level 0 - unusable SCTP addresses
394  * Level 1 - loopback address
395  * Level 2 - link-local addresses
396  * Level 3 - private addresses.
397  * Level 4 - global addresses
398  * For INIT and INIT-ACK address list, let L be the level of
399  * of requested destination address, sender and receiver
400  * SHOULD include all of its addresses with level greater
401  * than or equal to L.
402  *
403  * IPv4 scoping can be controlled through sysctl option
404  * net.sctp.addr_scope_policy
405  */
sctp_v4_scope(union sctp_addr * addr)406 static sctp_scope_t sctp_v4_scope(union sctp_addr *addr)
407 {
408 	sctp_scope_t retval;
409 
410 	/* Check for unusable SCTP addresses. */
411 	if (IS_IPV4_UNUSABLE_ADDRESS(addr->v4.sin_addr.s_addr)) {
412 		retval =  SCTP_SCOPE_UNUSABLE;
413 	} else if (ipv4_is_loopback(addr->v4.sin_addr.s_addr)) {
414 		retval = SCTP_SCOPE_LOOPBACK;
415 	} else if (ipv4_is_linklocal_169(addr->v4.sin_addr.s_addr)) {
416 		retval = SCTP_SCOPE_LINK;
417 	} else if (ipv4_is_private_10(addr->v4.sin_addr.s_addr) ||
418 		   ipv4_is_private_172(addr->v4.sin_addr.s_addr) ||
419 		   ipv4_is_private_192(addr->v4.sin_addr.s_addr) ||
420 		   ipv4_is_test_198(addr->v4.sin_addr.s_addr)) {
421 		retval = SCTP_SCOPE_PRIVATE;
422 	} else {
423 		retval = SCTP_SCOPE_GLOBAL;
424 	}
425 
426 	return retval;
427 }
428 
429 /* Returns a valid dst cache entry for the given source and destination ip
430  * addresses. If an association is passed, trys to get a dst entry with a
431  * source address that matches an address in the bind address list.
432  */
sctp_v4_get_dst(struct sctp_transport * t,union sctp_addr * saddr,struct flowi * fl,struct sock * sk)433 static void sctp_v4_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
434 				struct flowi *fl, struct sock *sk)
435 {
436 	struct sctp_association *asoc = t->asoc;
437 	struct rtable *rt;
438 	struct flowi _fl;
439 	struct flowi4 *fl4 = &_fl.u.ip4;
440 	struct sctp_bind_addr *bp;
441 	struct sctp_sockaddr_entry *laddr;
442 	struct dst_entry *dst = NULL;
443 	union sctp_addr *daddr = &t->ipaddr;
444 	union sctp_addr dst_saddr;
445 
446 	memset(&_fl, 0x0, sizeof(_fl));
447 	fl4->daddr  = daddr->v4.sin_addr.s_addr;
448 	fl4->fl4_dport = daddr->v4.sin_port;
449 	fl4->flowi4_proto = IPPROTO_SCTP;
450 	if (asoc) {
451 		fl4->flowi4_tos = RT_CONN_FLAGS(asoc->base.sk);
452 		fl4->flowi4_oif = asoc->base.sk->sk_bound_dev_if;
453 		fl4->fl4_sport = htons(asoc->base.bind_addr.port);
454 	}
455 	if (saddr) {
456 		fl4->saddr = saddr->v4.sin_addr.s_addr;
457 		fl4->fl4_sport = saddr->v4.sin_port;
458 	}
459 
460 	pr_debug("%s: dst:%pI4, src:%pI4 - ", __func__, &fl4->daddr,
461 		 &fl4->saddr);
462 
463 	rt = ip_route_output_key(sock_net(sk), fl4);
464 	if (!IS_ERR(rt)) {
465 		dst = &rt->dst;
466 		t->dst = dst;
467 		memcpy(fl, &_fl, sizeof(_fl));
468 	}
469 
470 	/* If there is no association or if a source address is passed, no
471 	 * more validation is required.
472 	 */
473 	if (!asoc || saddr)
474 		goto out;
475 
476 	bp = &asoc->base.bind_addr;
477 
478 	if (dst) {
479 		/* Walk through the bind address list and look for a bind
480 		 * address that matches the source address of the returned dst.
481 		 */
482 		sctp_v4_dst_saddr(&dst_saddr, fl4, htons(bp->port));
483 		rcu_read_lock();
484 		list_for_each_entry_rcu(laddr, &bp->address_list, list) {
485 			if (!laddr->valid || (laddr->state == SCTP_ADDR_DEL) ||
486 			    (laddr->state != SCTP_ADDR_SRC &&
487 			    !asoc->src_out_of_asoc_ok))
488 				continue;
489 			if (sctp_v4_cmp_addr(&dst_saddr, &laddr->a))
490 				goto out_unlock;
491 		}
492 		rcu_read_unlock();
493 
494 		/* None of the bound addresses match the source address of the
495 		 * dst. So release it.
496 		 */
497 		dst_release(dst);
498 		dst = NULL;
499 	}
500 
501 	/* Walk through the bind address list and try to get a dst that
502 	 * matches a bind address as the source address.
503 	 */
504 	rcu_read_lock();
505 	list_for_each_entry_rcu(laddr, &bp->address_list, list) {
506 		struct net_device *odev;
507 
508 		if (!laddr->valid)
509 			continue;
510 		if (laddr->state != SCTP_ADDR_SRC ||
511 		    AF_INET != laddr->a.sa.sa_family)
512 			continue;
513 
514 		fl4->fl4_sport = laddr->a.v4.sin_port;
515 		flowi4_update_output(fl4,
516 				     asoc->base.sk->sk_bound_dev_if,
517 				     RT_CONN_FLAGS(asoc->base.sk),
518 				     daddr->v4.sin_addr.s_addr,
519 				     laddr->a.v4.sin_addr.s_addr);
520 
521 		rt = ip_route_output_key(sock_net(sk), fl4);
522 		if (IS_ERR(rt))
523 			continue;
524 
525 		/* Ensure the src address belongs to the output
526 		 * interface.
527 		 */
528 		odev = __ip_dev_find(sock_net(sk), laddr->a.v4.sin_addr.s_addr,
529 				     false);
530 		if (!odev || odev->ifindex != fl4->flowi4_oif) {
531 			if (!dst) {
532 				dst = &rt->dst;
533 				t->dst = dst;
534 				memcpy(fl, &_fl, sizeof(_fl));
535 			} else {
536 				dst_release(&rt->dst);
537 			}
538 			continue;
539 		}
540 
541 		dst_release(dst);
542 		dst = &rt->dst;
543 		t->dst = dst;
544 		memcpy(fl, &_fl, sizeof(_fl));
545 		break;
546 	}
547 
548 out_unlock:
549 	rcu_read_unlock();
550 out:
551 	if (dst) {
552 		pr_debug("rt_dst:%pI4, rt_src:%pI4\n",
553 			 &fl->u.ip4.daddr, &fl->u.ip4.saddr);
554 	} else {
555 		t->dst = NULL;
556 		pr_debug("no route\n");
557 	}
558 }
559 
560 /* For v4, the source address is cached in the route entry(dst). So no need
561  * to cache it separately and hence this is an empty routine.
562  */
sctp_v4_get_saddr(struct sctp_sock * sk,struct sctp_transport * t,struct flowi * fl)563 static void sctp_v4_get_saddr(struct sctp_sock *sk,
564 			      struct sctp_transport *t,
565 			      struct flowi *fl)
566 {
567 	union sctp_addr *saddr = &t->saddr;
568 	struct rtable *rt = (struct rtable *)t->dst;
569 
570 	if (rt) {
571 		saddr->v4.sin_family = AF_INET;
572 		saddr->v4.sin_addr.s_addr = fl->u.ip4.saddr;
573 	}
574 }
575 
576 /* What interface did this skb arrive on? */
sctp_v4_skb_iif(const struct sk_buff * skb)577 static int sctp_v4_skb_iif(const struct sk_buff *skb)
578 {
579 	return inet_iif(skb);
580 }
581 
582 /* Was this packet marked by Explicit Congestion Notification? */
sctp_v4_is_ce(const struct sk_buff * skb)583 static int sctp_v4_is_ce(const struct sk_buff *skb)
584 {
585 	return INET_ECN_is_ce(ip_hdr(skb)->tos);
586 }
587 
588 /* Create and initialize a new sk for the socket returned by accept(). */
sctp_v4_create_accept_sk(struct sock * sk,struct sctp_association * asoc)589 static struct sock *sctp_v4_create_accept_sk(struct sock *sk,
590 					     struct sctp_association *asoc)
591 {
592 	struct sock *newsk = sk_alloc(sock_net(sk), PF_INET, GFP_KERNEL,
593 			sk->sk_prot, 0);
594 	struct inet_sock *newinet;
595 
596 	if (!newsk)
597 		goto out;
598 
599 	sock_init_data(NULL, newsk);
600 
601 	sctp_copy_sock(newsk, sk, asoc);
602 	sock_reset_flag(newsk, SOCK_ZAPPED);
603 
604 	newinet = inet_sk(newsk);
605 
606 	newinet->inet_daddr = asoc->peer.primary_addr.v4.sin_addr.s_addr;
607 
608 	sk_refcnt_debug_inc(newsk);
609 
610 	if (newsk->sk_prot->init(newsk)) {
611 		sk_common_release(newsk);
612 		newsk = NULL;
613 	}
614 
615 out:
616 	return newsk;
617 }
618 
sctp_v4_addr_to_user(struct sctp_sock * sp,union sctp_addr * addr)619 static int sctp_v4_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
620 {
621 	/* No address mapping for V4 sockets */
622 	memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
623 	return sizeof(struct sockaddr_in);
624 }
625 
626 /* Dump the v4 addr to the seq file. */
sctp_v4_seq_dump_addr(struct seq_file * seq,union sctp_addr * addr)627 static void sctp_v4_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
628 {
629 	seq_printf(seq, "%pI4 ", &addr->v4.sin_addr);
630 }
631 
sctp_v4_ecn_capable(struct sock * sk)632 static void sctp_v4_ecn_capable(struct sock *sk)
633 {
634 	INET_ECN_xmit(sk);
635 }
636 
sctp_addr_wq_timeout_handler(unsigned long arg)637 static void sctp_addr_wq_timeout_handler(unsigned long arg)
638 {
639 	struct net *net = (struct net *)arg;
640 	struct sctp_sockaddr_entry *addrw, *temp;
641 	struct sctp_sock *sp;
642 
643 	spin_lock_bh(&net->sctp.addr_wq_lock);
644 
645 	list_for_each_entry_safe(addrw, temp, &net->sctp.addr_waitq, list) {
646 		pr_debug("%s: the first ent in wq:%p is addr:%pISc for cmd:%d at "
647 			 "entry:%p\n", __func__, &net->sctp.addr_waitq, &addrw->a.sa,
648 			 addrw->state, addrw);
649 
650 #if IS_ENABLED(CONFIG_IPV6)
651 		/* Now we send an ASCONF for each association */
652 		/* Note. we currently don't handle link local IPv6 addressees */
653 		if (addrw->a.sa.sa_family == AF_INET6) {
654 			struct in6_addr *in6;
655 
656 			if (ipv6_addr_type(&addrw->a.v6.sin6_addr) &
657 			    IPV6_ADDR_LINKLOCAL)
658 				goto free_next;
659 
660 			in6 = (struct in6_addr *)&addrw->a.v6.sin6_addr;
661 			if (ipv6_chk_addr(net, in6, NULL, 0) == 0 &&
662 			    addrw->state == SCTP_ADDR_NEW) {
663 				unsigned long timeo_val;
664 
665 				pr_debug("%s: this is on DAD, trying %d sec "
666 					 "later\n", __func__,
667 					 SCTP_ADDRESS_TICK_DELAY);
668 
669 				timeo_val = jiffies;
670 				timeo_val += msecs_to_jiffies(SCTP_ADDRESS_TICK_DELAY);
671 				mod_timer(&net->sctp.addr_wq_timer, timeo_val);
672 				break;
673 			}
674 		}
675 #endif
676 		list_for_each_entry(sp, &net->sctp.auto_asconf_splist, auto_asconf_list) {
677 			struct sock *sk;
678 
679 			sk = sctp_opt2sk(sp);
680 			/* ignore bound-specific endpoints */
681 			if (!sctp_is_ep_boundall(sk))
682 				continue;
683 			bh_lock_sock(sk);
684 			if (sctp_asconf_mgmt(sp, addrw) < 0)
685 				pr_debug("%s: sctp_asconf_mgmt failed\n", __func__);
686 			bh_unlock_sock(sk);
687 		}
688 #if IS_ENABLED(CONFIG_IPV6)
689 free_next:
690 #endif
691 		list_del(&addrw->list);
692 		kfree(addrw);
693 	}
694 	spin_unlock_bh(&net->sctp.addr_wq_lock);
695 }
696 
sctp_free_addr_wq(struct net * net)697 static void sctp_free_addr_wq(struct net *net)
698 {
699 	struct sctp_sockaddr_entry *addrw;
700 	struct sctp_sockaddr_entry *temp;
701 
702 	spin_lock_bh(&net->sctp.addr_wq_lock);
703 	del_timer(&net->sctp.addr_wq_timer);
704 	list_for_each_entry_safe(addrw, temp, &net->sctp.addr_waitq, list) {
705 		list_del(&addrw->list);
706 		kfree(addrw);
707 	}
708 	spin_unlock_bh(&net->sctp.addr_wq_lock);
709 }
710 
711 /* lookup the entry for the same address in the addr_waitq
712  * sctp_addr_wq MUST be locked
713  */
sctp_addr_wq_lookup(struct net * net,struct sctp_sockaddr_entry * addr)714 static struct sctp_sockaddr_entry *sctp_addr_wq_lookup(struct net *net,
715 					struct sctp_sockaddr_entry *addr)
716 {
717 	struct sctp_sockaddr_entry *addrw;
718 
719 	list_for_each_entry(addrw, &net->sctp.addr_waitq, list) {
720 		if (addrw->a.sa.sa_family != addr->a.sa.sa_family)
721 			continue;
722 		if (addrw->a.sa.sa_family == AF_INET) {
723 			if (addrw->a.v4.sin_addr.s_addr ==
724 			    addr->a.v4.sin_addr.s_addr)
725 				return addrw;
726 		} else if (addrw->a.sa.sa_family == AF_INET6) {
727 			if (ipv6_addr_equal(&addrw->a.v6.sin6_addr,
728 			    &addr->a.v6.sin6_addr))
729 				return addrw;
730 		}
731 	}
732 	return NULL;
733 }
734 
sctp_addr_wq_mgmt(struct net * net,struct sctp_sockaddr_entry * addr,int cmd)735 void sctp_addr_wq_mgmt(struct net *net, struct sctp_sockaddr_entry *addr, int cmd)
736 {
737 	struct sctp_sockaddr_entry *addrw;
738 	unsigned long timeo_val;
739 
740 	/* first, we check if an opposite message already exist in the queue.
741 	 * If we found such message, it is removed.
742 	 * This operation is a bit stupid, but the DHCP client attaches the
743 	 * new address after a couple of addition and deletion of that address
744 	 */
745 
746 	spin_lock_bh(&net->sctp.addr_wq_lock);
747 	/* Offsets existing events in addr_wq */
748 	addrw = sctp_addr_wq_lookup(net, addr);
749 	if (addrw) {
750 		if (addrw->state != cmd) {
751 			pr_debug("%s: offsets existing entry for %d, addr:%pISc "
752 				 "in wq:%p\n", __func__, addrw->state, &addrw->a.sa,
753 				 &net->sctp.addr_waitq);
754 
755 			list_del(&addrw->list);
756 			kfree(addrw);
757 		}
758 		spin_unlock_bh(&net->sctp.addr_wq_lock);
759 		return;
760 	}
761 
762 	/* OK, we have to add the new address to the wait queue */
763 	addrw = kmemdup(addr, sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
764 	if (addrw == NULL) {
765 		spin_unlock_bh(&net->sctp.addr_wq_lock);
766 		return;
767 	}
768 	addrw->state = cmd;
769 	list_add_tail(&addrw->list, &net->sctp.addr_waitq);
770 
771 	pr_debug("%s: add new entry for cmd:%d, addr:%pISc in wq:%p\n",
772 		 __func__, addrw->state, &addrw->a.sa, &net->sctp.addr_waitq);
773 
774 	if (!timer_pending(&net->sctp.addr_wq_timer)) {
775 		timeo_val = jiffies;
776 		timeo_val += msecs_to_jiffies(SCTP_ADDRESS_TICK_DELAY);
777 		mod_timer(&net->sctp.addr_wq_timer, timeo_val);
778 	}
779 	spin_unlock_bh(&net->sctp.addr_wq_lock);
780 }
781 
782 /* Event handler for inet address addition/deletion events.
783  * The sctp_local_addr_list needs to be protocted by a spin lock since
784  * multiple notifiers (say IPv4 and IPv6) may be running at the same
785  * time and thus corrupt the list.
786  * The reader side is protected with RCU.
787  */
sctp_inetaddr_event(struct notifier_block * this,unsigned long ev,void * ptr)788 static int sctp_inetaddr_event(struct notifier_block *this, unsigned long ev,
789 			       void *ptr)
790 {
791 	struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
792 	struct sctp_sockaddr_entry *addr = NULL;
793 	struct sctp_sockaddr_entry *temp;
794 	struct net *net = dev_net(ifa->ifa_dev->dev);
795 	int found = 0;
796 
797 	switch (ev) {
798 	case NETDEV_UP:
799 		addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
800 		if (addr) {
801 			addr->a.v4.sin_family = AF_INET;
802 			addr->a.v4.sin_addr.s_addr = ifa->ifa_local;
803 			addr->valid = 1;
804 			spin_lock_bh(&net->sctp.local_addr_lock);
805 			list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
806 			sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
807 			spin_unlock_bh(&net->sctp.local_addr_lock);
808 		}
809 		break;
810 	case NETDEV_DOWN:
811 		spin_lock_bh(&net->sctp.local_addr_lock);
812 		list_for_each_entry_safe(addr, temp,
813 					&net->sctp.local_addr_list, list) {
814 			if (addr->a.sa.sa_family == AF_INET &&
815 					addr->a.v4.sin_addr.s_addr ==
816 					ifa->ifa_local) {
817 				sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
818 				found = 1;
819 				addr->valid = 0;
820 				list_del_rcu(&addr->list);
821 				break;
822 			}
823 		}
824 		spin_unlock_bh(&net->sctp.local_addr_lock);
825 		if (found)
826 			kfree_rcu(addr, rcu);
827 		break;
828 	}
829 
830 	return NOTIFY_DONE;
831 }
832 
833 /*
834  * Initialize the control inode/socket with a control endpoint data
835  * structure.  This endpoint is reserved exclusively for the OOTB processing.
836  */
sctp_ctl_sock_init(struct net * net)837 static int sctp_ctl_sock_init(struct net *net)
838 {
839 	int err;
840 	sa_family_t family = PF_INET;
841 
842 	if (sctp_get_pf_specific(PF_INET6))
843 		family = PF_INET6;
844 
845 	err = inet_ctl_sock_create(&net->sctp.ctl_sock, family,
846 				   SOCK_SEQPACKET, IPPROTO_SCTP, net);
847 
848 	/* If IPv6 socket could not be created, try the IPv4 socket */
849 	if (err < 0 && family == PF_INET6)
850 		err = inet_ctl_sock_create(&net->sctp.ctl_sock, AF_INET,
851 					   SOCK_SEQPACKET, IPPROTO_SCTP,
852 					   net);
853 
854 	if (err < 0) {
855 		pr_err("Failed to create the SCTP control socket\n");
856 		return err;
857 	}
858 	return 0;
859 }
860 
861 /* Register address family specific functions. */
sctp_register_af(struct sctp_af * af)862 int sctp_register_af(struct sctp_af *af)
863 {
864 	switch (af->sa_family) {
865 	case AF_INET:
866 		if (sctp_af_v4_specific)
867 			return 0;
868 		sctp_af_v4_specific = af;
869 		break;
870 	case AF_INET6:
871 		if (sctp_af_v6_specific)
872 			return 0;
873 		sctp_af_v6_specific = af;
874 		break;
875 	default:
876 		return 0;
877 	}
878 
879 	INIT_LIST_HEAD(&af->list);
880 	list_add_tail(&af->list, &sctp_address_families);
881 	return 1;
882 }
883 
884 /* Get the table of functions for manipulating a particular address
885  * family.
886  */
sctp_get_af_specific(sa_family_t family)887 struct sctp_af *sctp_get_af_specific(sa_family_t family)
888 {
889 	switch (family) {
890 	case AF_INET:
891 		return sctp_af_v4_specific;
892 	case AF_INET6:
893 		return sctp_af_v6_specific;
894 	default:
895 		return NULL;
896 	}
897 }
898 
899 /* Common code to initialize a AF_INET msg_name. */
sctp_inet_msgname(char * msgname,int * addr_len)900 static void sctp_inet_msgname(char *msgname, int *addr_len)
901 {
902 	struct sockaddr_in *sin;
903 
904 	sin = (struct sockaddr_in *)msgname;
905 	*addr_len = sizeof(struct sockaddr_in);
906 	sin->sin_family = AF_INET;
907 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
908 }
909 
910 /* Copy the primary address of the peer primary address as the msg_name. */
sctp_inet_event_msgname(struct sctp_ulpevent * event,char * msgname,int * addr_len)911 static void sctp_inet_event_msgname(struct sctp_ulpevent *event, char *msgname,
912 				    int *addr_len)
913 {
914 	struct sockaddr_in *sin, *sinfrom;
915 
916 	if (msgname) {
917 		struct sctp_association *asoc;
918 
919 		asoc = event->asoc;
920 		sctp_inet_msgname(msgname, addr_len);
921 		sin = (struct sockaddr_in *)msgname;
922 		sinfrom = &asoc->peer.primary_addr.v4;
923 		sin->sin_port = htons(asoc->peer.port);
924 		sin->sin_addr.s_addr = sinfrom->sin_addr.s_addr;
925 	}
926 }
927 
928 /* Initialize and copy out a msgname from an inbound skb. */
sctp_inet_skb_msgname(struct sk_buff * skb,char * msgname,int * len)929 static void sctp_inet_skb_msgname(struct sk_buff *skb, char *msgname, int *len)
930 {
931 	if (msgname) {
932 		struct sctphdr *sh = sctp_hdr(skb);
933 		struct sockaddr_in *sin = (struct sockaddr_in *)msgname;
934 
935 		sctp_inet_msgname(msgname, len);
936 		sin->sin_port = sh->source;
937 		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
938 	}
939 }
940 
941 /* Do we support this AF? */
sctp_inet_af_supported(sa_family_t family,struct sctp_sock * sp)942 static int sctp_inet_af_supported(sa_family_t family, struct sctp_sock *sp)
943 {
944 	/* PF_INET only supports AF_INET addresses. */
945 	return AF_INET == family;
946 }
947 
948 /* Address matching with wildcards allowed. */
sctp_inet_cmp_addr(const union sctp_addr * addr1,const union sctp_addr * addr2,struct sctp_sock * opt)949 static int sctp_inet_cmp_addr(const union sctp_addr *addr1,
950 			      const union sctp_addr *addr2,
951 			      struct sctp_sock *opt)
952 {
953 	/* PF_INET only supports AF_INET addresses. */
954 	if (addr1->sa.sa_family != addr2->sa.sa_family)
955 		return 0;
956 	if (htonl(INADDR_ANY) == addr1->v4.sin_addr.s_addr ||
957 	    htonl(INADDR_ANY) == addr2->v4.sin_addr.s_addr)
958 		return 1;
959 	if (addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr)
960 		return 1;
961 
962 	return 0;
963 }
964 
965 /* Verify that provided sockaddr looks bindable.  Common verification has
966  * already been taken care of.
967  */
sctp_inet_bind_verify(struct sctp_sock * opt,union sctp_addr * addr)968 static int sctp_inet_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
969 {
970 	return sctp_v4_available(addr, opt);
971 }
972 
973 /* Verify that sockaddr looks sendable.  Common verification has already
974  * been taken care of.
975  */
sctp_inet_send_verify(struct sctp_sock * opt,union sctp_addr * addr)976 static int sctp_inet_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
977 {
978 	return 1;
979 }
980 
981 /* Fill in Supported Address Type information for INIT and INIT-ACK
982  * chunks.  Returns number of addresses supported.
983  */
sctp_inet_supported_addrs(const struct sctp_sock * opt,__be16 * types)984 static int sctp_inet_supported_addrs(const struct sctp_sock *opt,
985 				     __be16 *types)
986 {
987 	types[0] = SCTP_PARAM_IPV4_ADDRESS;
988 	return 1;
989 }
990 
991 /* Wrapper routine that calls the ip transmit routine. */
sctp_v4_xmit(struct sk_buff * skb,struct sctp_transport * transport)992 static inline int sctp_v4_xmit(struct sk_buff *skb,
993 			       struct sctp_transport *transport)
994 {
995 	struct inet_sock *inet = inet_sk(skb->sk);
996 
997 	pr_debug("%s: skb:%p, len:%d, src:%pI4, dst:%pI4\n", __func__, skb,
998 		 skb->len, &transport->fl.u.ip4.saddr, &transport->fl.u.ip4.daddr);
999 
1000 	inet->pmtudisc = transport->param_flags & SPP_PMTUD_ENABLE ?
1001 			 IP_PMTUDISC_DO : IP_PMTUDISC_DONT;
1002 
1003 	SCTP_INC_STATS(sock_net(&inet->sk), SCTP_MIB_OUTSCTPPACKS);
1004 
1005 	return ip_queue_xmit(&inet->sk, skb, &transport->fl);
1006 }
1007 
1008 static struct sctp_af sctp_af_inet;
1009 
1010 static struct sctp_pf sctp_pf_inet = {
1011 	.event_msgname = sctp_inet_event_msgname,
1012 	.skb_msgname   = sctp_inet_skb_msgname,
1013 	.af_supported  = sctp_inet_af_supported,
1014 	.cmp_addr      = sctp_inet_cmp_addr,
1015 	.bind_verify   = sctp_inet_bind_verify,
1016 	.send_verify   = sctp_inet_send_verify,
1017 	.supported_addrs = sctp_inet_supported_addrs,
1018 	.create_accept_sk = sctp_v4_create_accept_sk,
1019 	.addr_to_user  = sctp_v4_addr_to_user,
1020 	.to_sk_saddr   = sctp_v4_to_sk_saddr,
1021 	.to_sk_daddr   = sctp_v4_to_sk_daddr,
1022 	.af            = &sctp_af_inet
1023 };
1024 
1025 /* Notifier for inetaddr addition/deletion events.  */
1026 static struct notifier_block sctp_inetaddr_notifier = {
1027 	.notifier_call = sctp_inetaddr_event,
1028 };
1029 
1030 /* Socket operations.  */
1031 static const struct proto_ops inet_seqpacket_ops = {
1032 	.family		   = PF_INET,
1033 	.owner		   = THIS_MODULE,
1034 	.release	   = inet_release,	/* Needs to be wrapped... */
1035 	.bind		   = inet_bind,
1036 	.connect	   = sctp_inet_connect,
1037 	.socketpair	   = sock_no_socketpair,
1038 	.accept		   = inet_accept,
1039 	.getname	   = inet_getname,	/* Semantics are different.  */
1040 	.poll		   = sctp_poll,
1041 	.ioctl		   = inet_ioctl,
1042 	.listen		   = sctp_inet_listen,
1043 	.shutdown	   = inet_shutdown,	/* Looks harmless.  */
1044 	.setsockopt	   = sock_common_setsockopt, /* IP_SOL IP_OPTION is a problem */
1045 	.getsockopt	   = sock_common_getsockopt,
1046 	.sendmsg	   = inet_sendmsg,
1047 	.recvmsg	   = sock_common_recvmsg,
1048 	.mmap		   = sock_no_mmap,
1049 	.sendpage	   = sock_no_sendpage,
1050 #ifdef CONFIG_COMPAT
1051 	.compat_setsockopt = compat_sock_common_setsockopt,
1052 	.compat_getsockopt = compat_sock_common_getsockopt,
1053 #endif
1054 };
1055 
1056 /* Registration with AF_INET family.  */
1057 static struct inet_protosw sctp_seqpacket_protosw = {
1058 	.type       = SOCK_SEQPACKET,
1059 	.protocol   = IPPROTO_SCTP,
1060 	.prot       = &sctp_prot,
1061 	.ops        = &inet_seqpacket_ops,
1062 	.flags      = SCTP_PROTOSW_FLAG
1063 };
1064 static struct inet_protosw sctp_stream_protosw = {
1065 	.type       = SOCK_STREAM,
1066 	.protocol   = IPPROTO_SCTP,
1067 	.prot       = &sctp_prot,
1068 	.ops        = &inet_seqpacket_ops,
1069 	.flags      = SCTP_PROTOSW_FLAG
1070 };
1071 
1072 /* Register with IP layer.  */
1073 static const struct net_protocol sctp_protocol = {
1074 	.handler     = sctp_rcv,
1075 	.err_handler = sctp_v4_err,
1076 	.no_policy   = 1,
1077 	.netns_ok    = 1,
1078 	.icmp_strict_tag_validation = 1,
1079 };
1080 
1081 /* IPv4 address related functions.  */
1082 static struct sctp_af sctp_af_inet = {
1083 	.sa_family	   = AF_INET,
1084 	.sctp_xmit	   = sctp_v4_xmit,
1085 	.setsockopt	   = ip_setsockopt,
1086 	.getsockopt	   = ip_getsockopt,
1087 	.get_dst	   = sctp_v4_get_dst,
1088 	.get_saddr	   = sctp_v4_get_saddr,
1089 	.copy_addrlist	   = sctp_v4_copy_addrlist,
1090 	.from_skb	   = sctp_v4_from_skb,
1091 	.from_sk	   = sctp_v4_from_sk,
1092 	.from_addr_param   = sctp_v4_from_addr_param,
1093 	.to_addr_param	   = sctp_v4_to_addr_param,
1094 	.cmp_addr	   = sctp_v4_cmp_addr,
1095 	.addr_valid	   = sctp_v4_addr_valid,
1096 	.inaddr_any	   = sctp_v4_inaddr_any,
1097 	.is_any		   = sctp_v4_is_any,
1098 	.available	   = sctp_v4_available,
1099 	.scope		   = sctp_v4_scope,
1100 	.skb_iif	   = sctp_v4_skb_iif,
1101 	.is_ce		   = sctp_v4_is_ce,
1102 	.seq_dump_addr	   = sctp_v4_seq_dump_addr,
1103 	.ecn_capable	   = sctp_v4_ecn_capable,
1104 	.net_header_len	   = sizeof(struct iphdr),
1105 	.sockaddr_len	   = sizeof(struct sockaddr_in),
1106 #ifdef CONFIG_COMPAT
1107 	.compat_setsockopt = compat_ip_setsockopt,
1108 	.compat_getsockopt = compat_ip_getsockopt,
1109 #endif
1110 };
1111 
sctp_get_pf_specific(sa_family_t family)1112 struct sctp_pf *sctp_get_pf_specific(sa_family_t family)
1113 {
1114 	switch (family) {
1115 	case PF_INET:
1116 		return sctp_pf_inet_specific;
1117 	case PF_INET6:
1118 		return sctp_pf_inet6_specific;
1119 	default:
1120 		return NULL;
1121 	}
1122 }
1123 
1124 /* Register the PF specific function table.  */
sctp_register_pf(struct sctp_pf * pf,sa_family_t family)1125 int sctp_register_pf(struct sctp_pf *pf, sa_family_t family)
1126 {
1127 	switch (family) {
1128 	case PF_INET:
1129 		if (sctp_pf_inet_specific)
1130 			return 0;
1131 		sctp_pf_inet_specific = pf;
1132 		break;
1133 	case PF_INET6:
1134 		if (sctp_pf_inet6_specific)
1135 			return 0;
1136 		sctp_pf_inet6_specific = pf;
1137 		break;
1138 	default:
1139 		return 0;
1140 	}
1141 	return 1;
1142 }
1143 
init_sctp_mibs(struct net * net)1144 static inline int init_sctp_mibs(struct net *net)
1145 {
1146 	net->sctp.sctp_statistics = alloc_percpu(struct sctp_mib);
1147 	if (!net->sctp.sctp_statistics)
1148 		return -ENOMEM;
1149 	return 0;
1150 }
1151 
cleanup_sctp_mibs(struct net * net)1152 static inline void cleanup_sctp_mibs(struct net *net)
1153 {
1154 	free_percpu(net->sctp.sctp_statistics);
1155 }
1156 
sctp_v4_pf_init(void)1157 static void sctp_v4_pf_init(void)
1158 {
1159 	/* Initialize the SCTP specific PF functions. */
1160 	sctp_register_pf(&sctp_pf_inet, PF_INET);
1161 	sctp_register_af(&sctp_af_inet);
1162 }
1163 
sctp_v4_pf_exit(void)1164 static void sctp_v4_pf_exit(void)
1165 {
1166 	list_del(&sctp_af_inet.list);
1167 }
1168 
sctp_v4_protosw_init(void)1169 static int sctp_v4_protosw_init(void)
1170 {
1171 	int rc;
1172 
1173 	rc = proto_register(&sctp_prot, 1);
1174 	if (rc)
1175 		return rc;
1176 
1177 	/* Register SCTP(UDP and TCP style) with socket layer.  */
1178 	inet_register_protosw(&sctp_seqpacket_protosw);
1179 	inet_register_protosw(&sctp_stream_protosw);
1180 
1181 	return 0;
1182 }
1183 
sctp_v4_protosw_exit(void)1184 static void sctp_v4_protosw_exit(void)
1185 {
1186 	inet_unregister_protosw(&sctp_stream_protosw);
1187 	inet_unregister_protosw(&sctp_seqpacket_protosw);
1188 	proto_unregister(&sctp_prot);
1189 }
1190 
sctp_v4_add_protocol(void)1191 static int sctp_v4_add_protocol(void)
1192 {
1193 	/* Register notifier for inet address additions/deletions. */
1194 	register_inetaddr_notifier(&sctp_inetaddr_notifier);
1195 
1196 	/* Register SCTP with inet layer.  */
1197 	if (inet_add_protocol(&sctp_protocol, IPPROTO_SCTP) < 0)
1198 		return -EAGAIN;
1199 
1200 	return 0;
1201 }
1202 
sctp_v4_del_protocol(void)1203 static void sctp_v4_del_protocol(void)
1204 {
1205 	inet_del_protocol(&sctp_protocol, IPPROTO_SCTP);
1206 	unregister_inetaddr_notifier(&sctp_inetaddr_notifier);
1207 }
1208 
sctp_defaults_init(struct net * net)1209 static int __net_init sctp_defaults_init(struct net *net)
1210 {
1211 	int status;
1212 
1213 	/*
1214 	 * 14. Suggested SCTP Protocol Parameter Values
1215 	 */
1216 	/* The following protocol parameters are RECOMMENDED:  */
1217 	/* RTO.Initial              - 3  seconds */
1218 	net->sctp.rto_initial			= SCTP_RTO_INITIAL;
1219 	/* RTO.Min                  - 1  second */
1220 	net->sctp.rto_min	 		= SCTP_RTO_MIN;
1221 	/* RTO.Max                 -  60 seconds */
1222 	net->sctp.rto_max 			= SCTP_RTO_MAX;
1223 	/* RTO.Alpha                - 1/8 */
1224 	net->sctp.rto_alpha			= SCTP_RTO_ALPHA;
1225 	/* RTO.Beta                 - 1/4 */
1226 	net->sctp.rto_beta			= SCTP_RTO_BETA;
1227 
1228 	/* Valid.Cookie.Life        - 60  seconds */
1229 	net->sctp.valid_cookie_life		= SCTP_DEFAULT_COOKIE_LIFE;
1230 
1231 	/* Whether Cookie Preservative is enabled(1) or not(0) */
1232 	net->sctp.cookie_preserve_enable 	= 1;
1233 
1234 	/* Default sctp sockets to use md5 as their hmac alg */
1235 #if defined (CONFIG_SCTP_DEFAULT_COOKIE_HMAC_MD5)
1236 	net->sctp.sctp_hmac_alg			= "md5";
1237 #elif defined (CONFIG_SCTP_DEFAULT_COOKIE_HMAC_SHA1)
1238 	net->sctp.sctp_hmac_alg			= "sha1";
1239 #else
1240 	net->sctp.sctp_hmac_alg			= NULL;
1241 #endif
1242 
1243 	/* Max.Burst		    - 4 */
1244 	net->sctp.max_burst			= SCTP_DEFAULT_MAX_BURST;
1245 
1246 	/* Association.Max.Retrans  - 10 attempts
1247 	 * Path.Max.Retrans         - 5  attempts (per destination address)
1248 	 * Max.Init.Retransmits     - 8  attempts
1249 	 */
1250 	net->sctp.max_retrans_association	= 10;
1251 	net->sctp.max_retrans_path		= 5;
1252 	net->sctp.max_retrans_init		= 8;
1253 
1254 	/* Sendbuffer growth	    - do per-socket accounting */
1255 	net->sctp.sndbuf_policy			= 0;
1256 
1257 	/* Rcvbuffer growth	    - do per-socket accounting */
1258 	net->sctp.rcvbuf_policy			= 0;
1259 
1260 	/* HB.interval              - 30 seconds */
1261 	net->sctp.hb_interval			= SCTP_DEFAULT_TIMEOUT_HEARTBEAT;
1262 
1263 	/* delayed SACK timeout */
1264 	net->sctp.sack_timeout			= SCTP_DEFAULT_TIMEOUT_SACK;
1265 
1266 	/* Disable ADDIP by default. */
1267 	net->sctp.addip_enable = 0;
1268 	net->sctp.addip_noauth = 0;
1269 	net->sctp.default_auto_asconf = 0;
1270 
1271 	/* Enable PR-SCTP by default. */
1272 	net->sctp.prsctp_enable = 1;
1273 
1274 	/* Disable AUTH by default. */
1275 	net->sctp.auth_enable = 0;
1276 
1277 	/* Set SCOPE policy to enabled */
1278 	net->sctp.scope_policy = SCTP_SCOPE_POLICY_ENABLE;
1279 
1280 	/* Set the default rwnd update threshold */
1281 	net->sctp.rwnd_upd_shift = SCTP_DEFAULT_RWND_SHIFT;
1282 
1283 	/* Initialize maximum autoclose timeout. */
1284 	net->sctp.max_autoclose		= INT_MAX / HZ;
1285 
1286 	status = sctp_sysctl_net_register(net);
1287 	if (status)
1288 		goto err_sysctl_register;
1289 
1290 	/* Allocate and initialise sctp mibs.  */
1291 	status = init_sctp_mibs(net);
1292 	if (status)
1293 		goto err_init_mibs;
1294 
1295 	/* Initialize proc fs directory.  */
1296 	status = sctp_proc_init(net);
1297 	if (status)
1298 		goto err_init_proc;
1299 
1300 	sctp_dbg_objcnt_init(net);
1301 
1302 	/* Initialize the local address list. */
1303 	INIT_LIST_HEAD(&net->sctp.local_addr_list);
1304 	spin_lock_init(&net->sctp.local_addr_lock);
1305 	sctp_get_local_addr_list(net);
1306 
1307 	/* Initialize the address event list */
1308 	INIT_LIST_HEAD(&net->sctp.addr_waitq);
1309 	INIT_LIST_HEAD(&net->sctp.auto_asconf_splist);
1310 	spin_lock_init(&net->sctp.addr_wq_lock);
1311 	net->sctp.addr_wq_timer.expires = 0;
1312 	setup_timer(&net->sctp.addr_wq_timer, sctp_addr_wq_timeout_handler,
1313 		    (unsigned long)net);
1314 
1315 	return 0;
1316 
1317 err_init_proc:
1318 	cleanup_sctp_mibs(net);
1319 err_init_mibs:
1320 	sctp_sysctl_net_unregister(net);
1321 err_sysctl_register:
1322 	return status;
1323 }
1324 
sctp_defaults_exit(struct net * net)1325 static void __net_exit sctp_defaults_exit(struct net *net)
1326 {
1327 	/* Free the local address list */
1328 	sctp_free_addr_wq(net);
1329 	sctp_free_local_addr_list(net);
1330 
1331 	sctp_dbg_objcnt_exit(net);
1332 
1333 	sctp_proc_exit(net);
1334 	cleanup_sctp_mibs(net);
1335 	sctp_sysctl_net_unregister(net);
1336 }
1337 
1338 static struct pernet_operations sctp_defaults_ops = {
1339 	.init = sctp_defaults_init,
1340 	.exit = sctp_defaults_exit,
1341 };
1342 
sctp_ctrlsock_init(struct net * net)1343 static int __net_init sctp_ctrlsock_init(struct net *net)
1344 {
1345 	int status;
1346 
1347 	/* Initialize the control inode/socket for handling OOTB packets.  */
1348 	status = sctp_ctl_sock_init(net);
1349 	if (status)
1350 		pr_err("Failed to initialize the SCTP control sock\n");
1351 
1352 	return status;
1353 }
1354 
sctp_ctrlsock_exit(struct net * net)1355 static void __net_exit sctp_ctrlsock_exit(struct net *net)
1356 {
1357 	/* Free the control endpoint.  */
1358 	inet_ctl_sock_destroy(net->sctp.ctl_sock);
1359 }
1360 
1361 static struct pernet_operations sctp_ctrlsock_ops = {
1362 	.init = sctp_ctrlsock_init,
1363 	.exit = sctp_ctrlsock_exit,
1364 };
1365 
1366 /* Initialize the universe into something sensible.  */
sctp_init(void)1367 static __init int sctp_init(void)
1368 {
1369 	int i;
1370 	int status = -EINVAL;
1371 	unsigned long goal;
1372 	unsigned long limit;
1373 	int max_share;
1374 	int order;
1375 	int num_entries;
1376 	int max_entry_order;
1377 
1378 	sock_skb_cb_check_size(sizeof(struct sctp_ulpevent));
1379 
1380 	/* Allocate bind_bucket and chunk caches. */
1381 	status = -ENOBUFS;
1382 	sctp_bucket_cachep = kmem_cache_create("sctp_bind_bucket",
1383 					       sizeof(struct sctp_bind_bucket),
1384 					       0, SLAB_HWCACHE_ALIGN,
1385 					       NULL);
1386 	if (!sctp_bucket_cachep)
1387 		goto out;
1388 
1389 	sctp_chunk_cachep = kmem_cache_create("sctp_chunk",
1390 					       sizeof(struct sctp_chunk),
1391 					       0, SLAB_HWCACHE_ALIGN,
1392 					       NULL);
1393 	if (!sctp_chunk_cachep)
1394 		goto err_chunk_cachep;
1395 
1396 	status = percpu_counter_init(&sctp_sockets_allocated, 0, GFP_KERNEL);
1397 	if (status)
1398 		goto err_percpu_counter_init;
1399 
1400 	/* Implementation specific variables. */
1401 
1402 	/* Initialize default stream count setup information. */
1403 	sctp_max_instreams    		= SCTP_DEFAULT_INSTREAMS;
1404 	sctp_max_outstreams   		= SCTP_DEFAULT_OUTSTREAMS;
1405 
1406 	/* Initialize handle used for association ids. */
1407 	idr_init(&sctp_assocs_id);
1408 
1409 	limit = nr_free_buffer_pages() / 8;
1410 	limit = max(limit, 128UL);
1411 	sysctl_sctp_mem[0] = limit / 4 * 3;
1412 	sysctl_sctp_mem[1] = limit;
1413 	sysctl_sctp_mem[2] = sysctl_sctp_mem[0] * 2;
1414 
1415 	/* Set per-socket limits to no more than 1/128 the pressure threshold*/
1416 	limit = (sysctl_sctp_mem[1]) << (PAGE_SHIFT - 7);
1417 	max_share = min(4UL*1024*1024, limit);
1418 
1419 	sysctl_sctp_rmem[0] = SK_MEM_QUANTUM; /* give each asoc 1 page min */
1420 	sysctl_sctp_rmem[1] = 1500 * SKB_TRUESIZE(1);
1421 	sysctl_sctp_rmem[2] = max(sysctl_sctp_rmem[1], max_share);
1422 
1423 	sysctl_sctp_wmem[0] = SK_MEM_QUANTUM;
1424 	sysctl_sctp_wmem[1] = 16*1024;
1425 	sysctl_sctp_wmem[2] = max(64*1024, max_share);
1426 
1427 	/* Size and allocate the association hash table.
1428 	 * The methodology is similar to that of the tcp hash tables.
1429 	 * Though not identical.  Start by getting a goal size
1430 	 */
1431 	if (totalram_pages >= (128 * 1024))
1432 		goal = totalram_pages >> (22 - PAGE_SHIFT);
1433 	else
1434 		goal = totalram_pages >> (24 - PAGE_SHIFT);
1435 
1436 	/* Then compute the page order for said goal */
1437 	order = get_order(goal);
1438 
1439 	/* Now compute the required page order for the maximum sized table we
1440 	 * want to create
1441 	 */
1442 	max_entry_order = get_order(MAX_SCTP_PORT_HASH_ENTRIES *
1443 				    sizeof(struct sctp_bind_hashbucket));
1444 
1445 	/* Limit the page order by that maximum hash table size */
1446 	order = min(order, max_entry_order);
1447 
1448 	do {
1449 		sctp_assoc_hashsize = (1UL << order) * PAGE_SIZE /
1450 					sizeof(struct sctp_hashbucket);
1451 		if ((sctp_assoc_hashsize > (64 * 1024)) && order > 0)
1452 			continue;
1453 		sctp_assoc_hashtable = (struct sctp_hashbucket *)
1454 			__get_free_pages(GFP_ATOMIC|__GFP_NOWARN, order);
1455 	} while (!sctp_assoc_hashtable && --order > 0);
1456 	if (!sctp_assoc_hashtable) {
1457 		pr_err("Failed association hash alloc\n");
1458 		status = -ENOMEM;
1459 		goto err_ahash_alloc;
1460 	}
1461 	for (i = 0; i < sctp_assoc_hashsize; i++) {
1462 		rwlock_init(&sctp_assoc_hashtable[i].lock);
1463 		INIT_HLIST_HEAD(&sctp_assoc_hashtable[i].chain);
1464 	}
1465 
1466 	/* Allocate and initialize the endpoint hash table.  */
1467 	sctp_ep_hashsize = 64;
1468 	sctp_ep_hashtable =
1469 		kmalloc(64 * sizeof(struct sctp_hashbucket), GFP_KERNEL);
1470 	if (!sctp_ep_hashtable) {
1471 		pr_err("Failed endpoint_hash alloc\n");
1472 		status = -ENOMEM;
1473 		goto err_ehash_alloc;
1474 	}
1475 	for (i = 0; i < sctp_ep_hashsize; i++) {
1476 		rwlock_init(&sctp_ep_hashtable[i].lock);
1477 		INIT_HLIST_HEAD(&sctp_ep_hashtable[i].chain);
1478 	}
1479 
1480 	/* Allocate and initialize the SCTP port hash table.
1481 	 * Note that order is initalized to start at the max sized
1482 	 * table we want to support.  If we can't get that many pages
1483 	 * reduce the order and try again
1484 	 */
1485 	do {
1486 		sctp_port_hashtable = (struct sctp_bind_hashbucket *)
1487 			__get_free_pages(GFP_ATOMIC|__GFP_NOWARN, order);
1488 	} while (!sctp_port_hashtable && --order > 0);
1489 
1490 	if (!sctp_port_hashtable) {
1491 		pr_err("Failed bind hash alloc\n");
1492 		status = -ENOMEM;
1493 		goto err_bhash_alloc;
1494 	}
1495 
1496 	/* Now compute the number of entries that will fit in the
1497 	 * port hash space we allocated
1498 	 */
1499 	num_entries = (1UL << order) * PAGE_SIZE /
1500 		      sizeof(struct sctp_bind_hashbucket);
1501 
1502 	/* And finish by rounding it down to the nearest power of two
1503 	 * this wastes some memory of course, but its needed because
1504 	 * the hash function operates based on the assumption that
1505 	 * that the number of entries is a power of two
1506 	 */
1507 	sctp_port_hashsize = rounddown_pow_of_two(num_entries);
1508 
1509 	for (i = 0; i < sctp_port_hashsize; i++) {
1510 		spin_lock_init(&sctp_port_hashtable[i].lock);
1511 		INIT_HLIST_HEAD(&sctp_port_hashtable[i].chain);
1512 	}
1513 
1514 	pr_info("Hash tables configured (established %d bind %d)\n",
1515 		sctp_assoc_hashsize, sctp_port_hashsize);
1516 
1517 	sctp_sysctl_register();
1518 
1519 	INIT_LIST_HEAD(&sctp_address_families);
1520 	sctp_v4_pf_init();
1521 	sctp_v6_pf_init();
1522 
1523 	status = register_pernet_subsys(&sctp_defaults_ops);
1524 	if (status)
1525 		goto err_register_defaults;
1526 
1527 	status = sctp_v4_protosw_init();
1528 	if (status)
1529 		goto err_protosw_init;
1530 
1531 	status = sctp_v6_protosw_init();
1532 	if (status)
1533 		goto err_v6_protosw_init;
1534 
1535 	status = register_pernet_subsys(&sctp_ctrlsock_ops);
1536 	if (status)
1537 		goto err_register_ctrlsock;
1538 
1539 	status = sctp_v4_add_protocol();
1540 	if (status)
1541 		goto err_add_protocol;
1542 
1543 	/* Register SCTP with inet6 layer.  */
1544 	status = sctp_v6_add_protocol();
1545 	if (status)
1546 		goto err_v6_add_protocol;
1547 
1548 out:
1549 	return status;
1550 err_v6_add_protocol:
1551 	sctp_v4_del_protocol();
1552 err_add_protocol:
1553 	unregister_pernet_subsys(&sctp_ctrlsock_ops);
1554 err_register_ctrlsock:
1555 	sctp_v6_protosw_exit();
1556 err_v6_protosw_init:
1557 	sctp_v4_protosw_exit();
1558 err_protosw_init:
1559 	unregister_pernet_subsys(&sctp_defaults_ops);
1560 err_register_defaults:
1561 	sctp_v4_pf_exit();
1562 	sctp_v6_pf_exit();
1563 	sctp_sysctl_unregister();
1564 	free_pages((unsigned long)sctp_port_hashtable,
1565 		   get_order(sctp_port_hashsize *
1566 			     sizeof(struct sctp_bind_hashbucket)));
1567 err_bhash_alloc:
1568 	kfree(sctp_ep_hashtable);
1569 err_ehash_alloc:
1570 	free_pages((unsigned long)sctp_assoc_hashtable,
1571 		   get_order(sctp_assoc_hashsize *
1572 			     sizeof(struct sctp_hashbucket)));
1573 err_ahash_alloc:
1574 	percpu_counter_destroy(&sctp_sockets_allocated);
1575 err_percpu_counter_init:
1576 	kmem_cache_destroy(sctp_chunk_cachep);
1577 err_chunk_cachep:
1578 	kmem_cache_destroy(sctp_bucket_cachep);
1579 	goto out;
1580 }
1581 
1582 /* Exit handler for the SCTP protocol.  */
sctp_exit(void)1583 static __exit void sctp_exit(void)
1584 {
1585 	/* BUG.  This should probably do something useful like clean
1586 	 * up all the remaining associations and all that memory.
1587 	 */
1588 
1589 	/* Unregister with inet6/inet layers. */
1590 	sctp_v6_del_protocol();
1591 	sctp_v4_del_protocol();
1592 
1593 	unregister_pernet_subsys(&sctp_ctrlsock_ops);
1594 
1595 	/* Free protosw registrations */
1596 	sctp_v6_protosw_exit();
1597 	sctp_v4_protosw_exit();
1598 
1599 	unregister_pernet_subsys(&sctp_defaults_ops);
1600 
1601 	/* Unregister with socket layer. */
1602 	sctp_v6_pf_exit();
1603 	sctp_v4_pf_exit();
1604 
1605 	sctp_sysctl_unregister();
1606 
1607 	free_pages((unsigned long)sctp_assoc_hashtable,
1608 		   get_order(sctp_assoc_hashsize *
1609 			     sizeof(struct sctp_hashbucket)));
1610 	kfree(sctp_ep_hashtable);
1611 	free_pages((unsigned long)sctp_port_hashtable,
1612 		   get_order(sctp_port_hashsize *
1613 			     sizeof(struct sctp_bind_hashbucket)));
1614 
1615 	percpu_counter_destroy(&sctp_sockets_allocated);
1616 
1617 	rcu_barrier(); /* Wait for completion of call_rcu()'s */
1618 
1619 	kmem_cache_destroy(sctp_chunk_cachep);
1620 	kmem_cache_destroy(sctp_bucket_cachep);
1621 }
1622 
1623 module_init(sctp_init);
1624 module_exit(sctp_exit);
1625 
1626 /*
1627  * __stringify doesn't likes enums, so use IPPROTO_SCTP value (132) directly.
1628  */
1629 MODULE_ALIAS("net-pf-" __stringify(PF_INET) "-proto-132");
1630 MODULE_ALIAS("net-pf-" __stringify(PF_INET6) "-proto-132");
1631 MODULE_AUTHOR("Linux Kernel SCTP developers <linux-sctp@vger.kernel.org>");
1632 MODULE_DESCRIPTION("Support for the SCTP protocol (RFC2960)");
1633 module_param_named(no_checksums, sctp_checksum_disable, bool, 0644);
1634 MODULE_PARM_DESC(no_checksums, "Disable checksums computing and verification");
1635 MODULE_LICENSE("GPL");
1636