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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 /* Private helper to extract ipv4 address and stash them in
84  * the protocol structure.
85  */
sctp_v4_copy_addrlist(struct list_head * addrlist,struct net_device * dev)86 static void sctp_v4_copy_addrlist(struct list_head *addrlist,
87 				  struct net_device *dev)
88 {
89 	struct in_device *in_dev;
90 	struct in_ifaddr *ifa;
91 	struct sctp_sockaddr_entry *addr;
92 
93 	rcu_read_lock();
94 	if ((in_dev = __in_dev_get_rcu(dev)) == NULL) {
95 		rcu_read_unlock();
96 		return;
97 	}
98 
99 	for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) {
100 		/* Add the address to the local list.  */
101 		addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
102 		if (addr) {
103 			addr->a.v4.sin_family = AF_INET;
104 			addr->a.v4.sin_addr.s_addr = ifa->ifa_local;
105 			addr->valid = 1;
106 			INIT_LIST_HEAD(&addr->list);
107 			list_add_tail(&addr->list, addrlist);
108 		}
109 	}
110 
111 	rcu_read_unlock();
112 }
113 
114 /* Extract our IP addresses from the system and stash them in the
115  * protocol structure.
116  */
sctp_get_local_addr_list(struct net * net)117 static void sctp_get_local_addr_list(struct net *net)
118 {
119 	struct net_device *dev;
120 	struct list_head *pos;
121 	struct sctp_af *af;
122 
123 	rcu_read_lock();
124 	for_each_netdev_rcu(net, dev) {
125 		list_for_each(pos, &sctp_address_families) {
126 			af = list_entry(pos, struct sctp_af, list);
127 			af->copy_addrlist(&net->sctp.local_addr_list, dev);
128 		}
129 	}
130 	rcu_read_unlock();
131 }
132 
133 /* Free the existing local addresses.  */
sctp_free_local_addr_list(struct net * net)134 static void sctp_free_local_addr_list(struct net *net)
135 {
136 	struct sctp_sockaddr_entry *addr;
137 	struct list_head *pos, *temp;
138 
139 	list_for_each_safe(pos, temp, &net->sctp.local_addr_list) {
140 		addr = list_entry(pos, struct sctp_sockaddr_entry, list);
141 		list_del(pos);
142 		kfree(addr);
143 	}
144 }
145 
146 /* Copy the local addresses which are valid for 'scope' into 'bp'.  */
sctp_copy_local_addr_list(struct net * net,struct sctp_bind_addr * bp,enum sctp_scope scope,gfp_t gfp,int copy_flags)147 int sctp_copy_local_addr_list(struct net *net, struct sctp_bind_addr *bp,
148 			      enum sctp_scope scope, gfp_t gfp, int copy_flags)
149 {
150 	struct sctp_sockaddr_entry *addr;
151 	union sctp_addr laddr;
152 	int error = 0;
153 
154 	rcu_read_lock();
155 	list_for_each_entry_rcu(addr, &net->sctp.local_addr_list, list) {
156 		if (!addr->valid)
157 			continue;
158 		if (!sctp_in_scope(net, &addr->a, scope))
159 			continue;
160 
161 		/* Now that the address is in scope, check to see if
162 		 * the address type is really supported by the local
163 		 * sock as well as the remote peer.
164 		 */
165 		if (addr->a.sa.sa_family == AF_INET &&
166 		    (!(copy_flags & SCTP_ADDR4_ALLOWED) ||
167 		     !(copy_flags & SCTP_ADDR4_PEERSUPP)))
168 			continue;
169 		if (addr->a.sa.sa_family == AF_INET6 &&
170 		    (!(copy_flags & SCTP_ADDR6_ALLOWED) ||
171 		     !(copy_flags & SCTP_ADDR6_PEERSUPP)))
172 			continue;
173 
174 		laddr = addr->a;
175 		/* also works for setting ipv6 address port */
176 		laddr.v4.sin_port = htons(bp->port);
177 		if (sctp_bind_addr_state(bp, &laddr) != -1)
178 			continue;
179 
180 		error = sctp_add_bind_addr(bp, &addr->a, sizeof(addr->a),
181 					   SCTP_ADDR_SRC, GFP_ATOMIC);
182 		if (error)
183 			break;
184 	}
185 
186 	rcu_read_unlock();
187 	return error;
188 }
189 
190 /* Copy over any ip options */
sctp_v4_copy_ip_options(struct sock * sk,struct sock * newsk)191 static void sctp_v4_copy_ip_options(struct sock *sk, struct sock *newsk)
192 {
193 	struct inet_sock *newinet, *inet = inet_sk(sk);
194 	struct ip_options_rcu *inet_opt, *newopt = NULL;
195 
196 	newinet = inet_sk(newsk);
197 
198 	rcu_read_lock();
199 	inet_opt = rcu_dereference(inet->inet_opt);
200 	if (inet_opt) {
201 		newopt = sock_kmalloc(newsk, sizeof(*inet_opt) +
202 				      inet_opt->opt.optlen, GFP_ATOMIC);
203 		if (newopt)
204 			memcpy(newopt, inet_opt, sizeof(*inet_opt) +
205 			       inet_opt->opt.optlen);
206 		else
207 			pr_err("%s: Failed to copy ip options\n", __func__);
208 	}
209 	RCU_INIT_POINTER(newinet->inet_opt, newopt);
210 	rcu_read_unlock();
211 }
212 
213 /* Account for the IP options */
sctp_v4_ip_options_len(struct sock * sk)214 static int sctp_v4_ip_options_len(struct sock *sk)
215 {
216 	struct inet_sock *inet = inet_sk(sk);
217 	struct ip_options_rcu *inet_opt;
218 	int len = 0;
219 
220 	rcu_read_lock();
221 	inet_opt = rcu_dereference(inet->inet_opt);
222 	if (inet_opt)
223 		len = inet_opt->opt.optlen;
224 
225 	rcu_read_unlock();
226 	return len;
227 }
228 
229 /* Initialize a sctp_addr from in incoming skb.  */
sctp_v4_from_skb(union sctp_addr * addr,struct sk_buff * skb,int is_saddr)230 static void sctp_v4_from_skb(union sctp_addr *addr, struct sk_buff *skb,
231 			     int is_saddr)
232 {
233 	/* Always called on head skb, so this is safe */
234 	struct sctphdr *sh = sctp_hdr(skb);
235 	struct sockaddr_in *sa = &addr->v4;
236 
237 	addr->v4.sin_family = AF_INET;
238 
239 	if (is_saddr) {
240 		sa->sin_port = sh->source;
241 		sa->sin_addr.s_addr = ip_hdr(skb)->saddr;
242 	} else {
243 		sa->sin_port = sh->dest;
244 		sa->sin_addr.s_addr = ip_hdr(skb)->daddr;
245 	}
246 	memset(sa->sin_zero, 0, sizeof(sa->sin_zero));
247 }
248 
249 /* Initialize an sctp_addr from a socket. */
sctp_v4_from_sk(union sctp_addr * addr,struct sock * sk)250 static void sctp_v4_from_sk(union sctp_addr *addr, struct sock *sk)
251 {
252 	addr->v4.sin_family = AF_INET;
253 	addr->v4.sin_port = 0;
254 	addr->v4.sin_addr.s_addr = inet_sk(sk)->inet_rcv_saddr;
255 	memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
256 }
257 
258 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
sctp_v4_to_sk_saddr(union sctp_addr * addr,struct sock * sk)259 static void sctp_v4_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
260 {
261 	inet_sk(sk)->inet_rcv_saddr = addr->v4.sin_addr.s_addr;
262 }
263 
264 /* Initialize sk->sk_daddr from sctp_addr. */
sctp_v4_to_sk_daddr(union sctp_addr * addr,struct sock * sk)265 static void sctp_v4_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
266 {
267 	inet_sk(sk)->inet_daddr = addr->v4.sin_addr.s_addr;
268 }
269 
270 /* 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)271 static bool sctp_v4_from_addr_param(union sctp_addr *addr,
272 				    union sctp_addr_param *param,
273 				    __be16 port, int iif)
274 {
275 	if (ntohs(param->v4.param_hdr.length) < sizeof(struct sctp_ipv4addr_param))
276 		return false;
277 
278 	addr->v4.sin_family = AF_INET;
279 	addr->v4.sin_port = port;
280 	addr->v4.sin_addr.s_addr = param->v4.addr.s_addr;
281 	memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
282 
283 	return true;
284 }
285 
286 /* Initialize an address parameter from a sctp_addr and return the length
287  * of the address parameter.
288  */
sctp_v4_to_addr_param(const union sctp_addr * addr,union sctp_addr_param * param)289 static int sctp_v4_to_addr_param(const union sctp_addr *addr,
290 				 union sctp_addr_param *param)
291 {
292 	int length = sizeof(struct sctp_ipv4addr_param);
293 
294 	param->v4.param_hdr.type = SCTP_PARAM_IPV4_ADDRESS;
295 	param->v4.param_hdr.length = htons(length);
296 	param->v4.addr.s_addr = addr->v4.sin_addr.s_addr;
297 
298 	return length;
299 }
300 
301 /* Initialize a sctp_addr from a dst_entry. */
sctp_v4_dst_saddr(union sctp_addr * saddr,struct flowi4 * fl4,__be16 port)302 static void sctp_v4_dst_saddr(union sctp_addr *saddr, struct flowi4 *fl4,
303 			      __be16 port)
304 {
305 	saddr->v4.sin_family = AF_INET;
306 	saddr->v4.sin_port = port;
307 	saddr->v4.sin_addr.s_addr = fl4->saddr;
308 	memset(saddr->v4.sin_zero, 0, sizeof(saddr->v4.sin_zero));
309 }
310 
311 /* Compare two addresses exactly. */
sctp_v4_cmp_addr(const union sctp_addr * addr1,const union sctp_addr * addr2)312 static int sctp_v4_cmp_addr(const union sctp_addr *addr1,
313 			    const union sctp_addr *addr2)
314 {
315 	if (addr1->sa.sa_family != addr2->sa.sa_family)
316 		return 0;
317 	if (addr1->v4.sin_port != addr2->v4.sin_port)
318 		return 0;
319 	if (addr1->v4.sin_addr.s_addr != addr2->v4.sin_addr.s_addr)
320 		return 0;
321 
322 	return 1;
323 }
324 
325 /* Initialize addr struct to INADDR_ANY. */
sctp_v4_inaddr_any(union sctp_addr * addr,__be16 port)326 static void sctp_v4_inaddr_any(union sctp_addr *addr, __be16 port)
327 {
328 	addr->v4.sin_family = AF_INET;
329 	addr->v4.sin_addr.s_addr = htonl(INADDR_ANY);
330 	addr->v4.sin_port = port;
331 	memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
332 }
333 
334 /* Is this a wildcard address? */
sctp_v4_is_any(const union sctp_addr * addr)335 static int sctp_v4_is_any(const union sctp_addr *addr)
336 {
337 	return htonl(INADDR_ANY) == addr->v4.sin_addr.s_addr;
338 }
339 
340 /* This function checks if the address is a valid address to be used for
341  * SCTP binding.
342  *
343  * Output:
344  * Return 0 - If the address is a non-unicast or an illegal address.
345  * Return 1 - If the address is a unicast.
346  */
sctp_v4_addr_valid(union sctp_addr * addr,struct sctp_sock * sp,const struct sk_buff * skb)347 static int sctp_v4_addr_valid(union sctp_addr *addr,
348 			      struct sctp_sock *sp,
349 			      const struct sk_buff *skb)
350 {
351 	/* IPv4 addresses not allowed */
352 	if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
353 		return 0;
354 
355 	/* Is this a non-unicast address or a unusable SCTP address? */
356 	if (IS_IPV4_UNUSABLE_ADDRESS(addr->v4.sin_addr.s_addr))
357 		return 0;
358 
359 	/* Is this a broadcast address? */
360 	if (skb && skb_rtable(skb)->rt_flags & RTCF_BROADCAST)
361 		return 0;
362 
363 	return 1;
364 }
365 
366 /* Should this be available for binding?   */
sctp_v4_available(union sctp_addr * addr,struct sctp_sock * sp)367 static int sctp_v4_available(union sctp_addr *addr, struct sctp_sock *sp)
368 {
369 	struct net *net = sock_net(&sp->inet.sk);
370 	int ret = inet_addr_type(net, addr->v4.sin_addr.s_addr);
371 
372 
373 	if (addr->v4.sin_addr.s_addr != htonl(INADDR_ANY) &&
374 	   ret != RTN_LOCAL &&
375 	   !sp->inet.freebind &&
376 	   !net->ipv4.sysctl_ip_nonlocal_bind)
377 		return 0;
378 
379 	if (ipv6_only_sock(sctp_opt2sk(sp)))
380 		return 0;
381 
382 	return 1;
383 }
384 
385 /* Checking the loopback, private and other address scopes as defined in
386  * RFC 1918.   The IPv4 scoping is based on the draft for SCTP IPv4
387  * scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>.
388  *
389  * Level 0 - unusable SCTP addresses
390  * Level 1 - loopback address
391  * Level 2 - link-local addresses
392  * Level 3 - private addresses.
393  * Level 4 - global addresses
394  * For INIT and INIT-ACK address list, let L be the level of
395  * of requested destination address, sender and receiver
396  * SHOULD include all of its addresses with level greater
397  * than or equal to L.
398  *
399  * IPv4 scoping can be controlled through sysctl option
400  * net.sctp.addr_scope_policy
401  */
sctp_v4_scope(union sctp_addr * addr)402 static enum sctp_scope sctp_v4_scope(union sctp_addr *addr)
403 {
404 	enum sctp_scope retval;
405 
406 	/* Check for unusable SCTP addresses. */
407 	if (IS_IPV4_UNUSABLE_ADDRESS(addr->v4.sin_addr.s_addr)) {
408 		retval =  SCTP_SCOPE_UNUSABLE;
409 	} else if (ipv4_is_loopback(addr->v4.sin_addr.s_addr)) {
410 		retval = SCTP_SCOPE_LOOPBACK;
411 	} else if (ipv4_is_linklocal_169(addr->v4.sin_addr.s_addr)) {
412 		retval = SCTP_SCOPE_LINK;
413 	} else if (ipv4_is_private_10(addr->v4.sin_addr.s_addr) ||
414 		   ipv4_is_private_172(addr->v4.sin_addr.s_addr) ||
415 		   ipv4_is_private_192(addr->v4.sin_addr.s_addr)) {
416 		retval = SCTP_SCOPE_PRIVATE;
417 	} else {
418 		retval = SCTP_SCOPE_GLOBAL;
419 	}
420 
421 	return retval;
422 }
423 
424 /* Returns a valid dst cache entry for the given source and destination ip
425  * addresses. If an association is passed, trys to get a dst entry with a
426  * source address that matches an address in the bind address list.
427  */
sctp_v4_get_dst(struct sctp_transport * t,union sctp_addr * saddr,struct flowi * fl,struct sock * sk)428 static void sctp_v4_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
429 				struct flowi *fl, struct sock *sk)
430 {
431 	struct sctp_association *asoc = t->asoc;
432 	struct rtable *rt;
433 	struct flowi _fl;
434 	struct flowi4 *fl4 = &_fl.u.ip4;
435 	struct sctp_bind_addr *bp;
436 	struct sctp_sockaddr_entry *laddr;
437 	struct dst_entry *dst = NULL;
438 	union sctp_addr *daddr = &t->ipaddr;
439 	union sctp_addr dst_saddr;
440 	__u8 tos = inet_sk(sk)->tos;
441 
442 	if (t->dscp & SCTP_DSCP_SET_MASK)
443 		tos = t->dscp & SCTP_DSCP_VAL_MASK;
444 	memset(&_fl, 0x0, sizeof(_fl));
445 	fl4->daddr  = daddr->v4.sin_addr.s_addr;
446 	fl4->fl4_dport = daddr->v4.sin_port;
447 	fl4->flowi4_proto = IPPROTO_SCTP;
448 	if (asoc) {
449 		fl4->flowi4_tos = RT_CONN_FLAGS_TOS(asoc->base.sk, tos);
450 		fl4->flowi4_oif = asoc->base.sk->sk_bound_dev_if;
451 		fl4->fl4_sport = htons(asoc->base.bind_addr.port);
452 	}
453 	if (saddr) {
454 		fl4->saddr = saddr->v4.sin_addr.s_addr;
455 		if (!fl4->fl4_sport)
456 			fl4->fl4_sport = saddr->v4.sin_port;
457 	}
458 
459 	pr_debug("%s: dst:%pI4, src:%pI4 - ", __func__, &fl4->daddr,
460 		 &fl4->saddr);
461 
462 	rt = ip_route_output_key(sock_net(sk), fl4);
463 	if (!IS_ERR(rt)) {
464 		dst = &rt->dst;
465 		t->dst = dst;
466 		memcpy(fl, &_fl, sizeof(_fl));
467 	}
468 
469 	/* If there is no association or if a source address is passed, no
470 	 * more validation is required.
471 	 */
472 	if (!asoc || saddr)
473 		goto out;
474 
475 	bp = &asoc->base.bind_addr;
476 
477 	if (dst) {
478 		/* Walk through the bind address list and look for a bind
479 		 * address that matches the source address of the returned dst.
480 		 */
481 		sctp_v4_dst_saddr(&dst_saddr, fl4, htons(bp->port));
482 		rcu_read_lock();
483 		list_for_each_entry_rcu(laddr, &bp->address_list, list) {
484 			if (!laddr->valid || (laddr->state == SCTP_ADDR_DEL) ||
485 			    (laddr->state != SCTP_ADDR_SRC &&
486 			    !asoc->src_out_of_asoc_ok))
487 				continue;
488 			if (sctp_v4_cmp_addr(&dst_saddr, &laddr->a))
489 				goto out_unlock;
490 		}
491 		rcu_read_unlock();
492 
493 		/* None of the bound addresses match the source address of the
494 		 * dst. So release it.
495 		 */
496 		dst_release(dst);
497 		dst = NULL;
498 	}
499 
500 	/* Walk through the bind address list and try to get a dst that
501 	 * matches a bind address as the source address.
502 	 */
503 	rcu_read_lock();
504 	list_for_each_entry_rcu(laddr, &bp->address_list, list) {
505 		struct net_device *odev;
506 
507 		if (!laddr->valid)
508 			continue;
509 		if (laddr->state != SCTP_ADDR_SRC ||
510 		    AF_INET != laddr->a.sa.sa_family)
511 			continue;
512 
513 		fl4->fl4_sport = laddr->a.v4.sin_port;
514 		flowi4_update_output(fl4,
515 				     asoc->base.sk->sk_bound_dev_if,
516 				     RT_CONN_FLAGS_TOS(asoc->base.sk, tos),
517 				     daddr->v4.sin_addr.s_addr,
518 				     laddr->a.v4.sin_addr.s_addr);
519 
520 		rt = ip_route_output_key(sock_net(sk), fl4);
521 		if (IS_ERR(rt))
522 			continue;
523 
524 		/* Ensure the src address belongs to the output
525 		 * interface.
526 		 */
527 		odev = __ip_dev_find(sock_net(sk), laddr->a.v4.sin_addr.s_addr,
528 				     false);
529 		if (!odev || odev->ifindex != fl4->flowi4_oif) {
530 			if (!dst) {
531 				dst = &rt->dst;
532 				t->dst = dst;
533 				memcpy(fl, &_fl, sizeof(_fl));
534 			} else {
535 				dst_release(&rt->dst);
536 			}
537 			continue;
538 		}
539 
540 		dst_release(dst);
541 		dst = &rt->dst;
542 		t->dst = dst;
543 		memcpy(fl, &_fl, sizeof(_fl));
544 		break;
545 	}
546 
547 out_unlock:
548 	rcu_read_unlock();
549 out:
550 	if (dst) {
551 		pr_debug("rt_dst:%pI4, rt_src:%pI4\n",
552 			 &fl->u.ip4.daddr, &fl->u.ip4.saddr);
553 	} else {
554 		t->dst = NULL;
555 		pr_debug("no route\n");
556 	}
557 }
558 
559 /* For v4, the source address is cached in the route entry(dst). So no need
560  * to cache it separately and hence this is an empty routine.
561  */
sctp_v4_get_saddr(struct sctp_sock * sk,struct sctp_transport * t,struct flowi * fl)562 static void sctp_v4_get_saddr(struct sctp_sock *sk,
563 			      struct sctp_transport *t,
564 			      struct flowi *fl)
565 {
566 	union sctp_addr *saddr = &t->saddr;
567 	struct rtable *rt = (struct rtable *)t->dst;
568 
569 	if (rt) {
570 		saddr->v4.sin_family = AF_INET;
571 		saddr->v4.sin_addr.s_addr = fl->u.ip4.saddr;
572 	}
573 }
574 
575 /* What interface did this skb arrive on? */
sctp_v4_skb_iif(const struct sk_buff * skb)576 static int sctp_v4_skb_iif(const struct sk_buff *skb)
577 {
578 	return inet_iif(skb);
579 }
580 
581 /* Was this packet marked by Explicit Congestion Notification? */
sctp_v4_is_ce(const struct sk_buff * skb)582 static int sctp_v4_is_ce(const struct sk_buff *skb)
583 {
584 	return INET_ECN_is_ce(ip_hdr(skb)->tos);
585 }
586 
587 /* Create and initialize a new sk for the socket returned by accept(). */
sctp_v4_create_accept_sk(struct sock * sk,struct sctp_association * asoc,bool kern)588 static struct sock *sctp_v4_create_accept_sk(struct sock *sk,
589 					     struct sctp_association *asoc,
590 					     bool kern)
591 {
592 	struct sock *newsk = sk_alloc(sock_net(sk), PF_INET, GFP_KERNEL,
593 			sk->sk_prot, kern);
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 	sctp_v4_copy_ip_options(sk, newsk);
605 
606 	newinet = inet_sk(newsk);
607 
608 	newinet->inet_daddr = asoc->peer.primary_addr.v4.sin_addr.s_addr;
609 
610 	sk_refcnt_debug_inc(newsk);
611 
612 	if (newsk->sk_prot->init(newsk)) {
613 		sk_common_release(newsk);
614 		newsk = NULL;
615 	}
616 
617 out:
618 	return newsk;
619 }
620 
sctp_v4_addr_to_user(struct sctp_sock * sp,union sctp_addr * addr)621 static int sctp_v4_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
622 {
623 	/* No address mapping for V4 sockets */
624 	memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
625 	return sizeof(struct sockaddr_in);
626 }
627 
628 /* Dump the v4 addr to the seq file. */
sctp_v4_seq_dump_addr(struct seq_file * seq,union sctp_addr * addr)629 static void sctp_v4_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
630 {
631 	seq_printf(seq, "%pI4 ", &addr->v4.sin_addr);
632 }
633 
sctp_v4_ecn_capable(struct sock * sk)634 static void sctp_v4_ecn_capable(struct sock *sk)
635 {
636 	INET_ECN_xmit(sk);
637 }
638 
sctp_addr_wq_timeout_handler(struct timer_list * t)639 static void sctp_addr_wq_timeout_handler(struct timer_list *t)
640 {
641 	struct net *net = from_timer(net, t, sctp.addr_wq_timer);
642 	struct sctp_sockaddr_entry *addrw, *temp;
643 	struct sctp_sock *sp;
644 
645 	spin_lock_bh(&net->sctp.addr_wq_lock);
646 
647 	list_for_each_entry_safe(addrw, temp, &net->sctp.addr_waitq, list) {
648 		pr_debug("%s: the first ent in wq:%p is addr:%pISc for cmd:%d at "
649 			 "entry:%p\n", __func__, &net->sctp.addr_waitq, &addrw->a.sa,
650 			 addrw->state, addrw);
651 
652 #if IS_ENABLED(CONFIG_IPV6)
653 		/* Now we send an ASCONF for each association */
654 		/* Note. we currently don't handle link local IPv6 addressees */
655 		if (addrw->a.sa.sa_family == AF_INET6) {
656 			struct in6_addr *in6;
657 
658 			if (ipv6_addr_type(&addrw->a.v6.sin6_addr) &
659 			    IPV6_ADDR_LINKLOCAL)
660 				goto free_next;
661 
662 			in6 = (struct in6_addr *)&addrw->a.v6.sin6_addr;
663 			if (ipv6_chk_addr(net, in6, NULL, 0) == 0 &&
664 			    addrw->state == SCTP_ADDR_NEW) {
665 				unsigned long timeo_val;
666 
667 				pr_debug("%s: this is on DAD, trying %d sec "
668 					 "later\n", __func__,
669 					 SCTP_ADDRESS_TICK_DELAY);
670 
671 				timeo_val = jiffies;
672 				timeo_val += msecs_to_jiffies(SCTP_ADDRESS_TICK_DELAY);
673 				mod_timer(&net->sctp.addr_wq_timer, timeo_val);
674 				break;
675 			}
676 		}
677 #endif
678 		list_for_each_entry(sp, &net->sctp.auto_asconf_splist, auto_asconf_list) {
679 			struct sock *sk;
680 
681 			sk = sctp_opt2sk(sp);
682 			/* ignore bound-specific endpoints */
683 			if (!sctp_is_ep_boundall(sk))
684 				continue;
685 			bh_lock_sock(sk);
686 			if (sctp_asconf_mgmt(sp, addrw) < 0)
687 				pr_debug("%s: sctp_asconf_mgmt failed\n", __func__);
688 			bh_unlock_sock(sk);
689 		}
690 #if IS_ENABLED(CONFIG_IPV6)
691 free_next:
692 #endif
693 		list_del(&addrw->list);
694 		kfree(addrw);
695 	}
696 	spin_unlock_bh(&net->sctp.addr_wq_lock);
697 }
698 
sctp_free_addr_wq(struct net * net)699 static void sctp_free_addr_wq(struct net *net)
700 {
701 	struct sctp_sockaddr_entry *addrw;
702 	struct sctp_sockaddr_entry *temp;
703 
704 	spin_lock_bh(&net->sctp.addr_wq_lock);
705 	del_timer(&net->sctp.addr_wq_timer);
706 	list_for_each_entry_safe(addrw, temp, &net->sctp.addr_waitq, list) {
707 		list_del(&addrw->list);
708 		kfree(addrw);
709 	}
710 	spin_unlock_bh(&net->sctp.addr_wq_lock);
711 }
712 
713 /* lookup the entry for the same address in the addr_waitq
714  * sctp_addr_wq MUST be locked
715  */
sctp_addr_wq_lookup(struct net * net,struct sctp_sockaddr_entry * addr)716 static struct sctp_sockaddr_entry *sctp_addr_wq_lookup(struct net *net,
717 					struct sctp_sockaddr_entry *addr)
718 {
719 	struct sctp_sockaddr_entry *addrw;
720 
721 	list_for_each_entry(addrw, &net->sctp.addr_waitq, list) {
722 		if (addrw->a.sa.sa_family != addr->a.sa.sa_family)
723 			continue;
724 		if (addrw->a.sa.sa_family == AF_INET) {
725 			if (addrw->a.v4.sin_addr.s_addr ==
726 			    addr->a.v4.sin_addr.s_addr)
727 				return addrw;
728 		} else if (addrw->a.sa.sa_family == AF_INET6) {
729 			if (ipv6_addr_equal(&addrw->a.v6.sin6_addr,
730 			    &addr->a.v6.sin6_addr))
731 				return addrw;
732 		}
733 	}
734 	return NULL;
735 }
736 
sctp_addr_wq_mgmt(struct net * net,struct sctp_sockaddr_entry * addr,int cmd)737 void sctp_addr_wq_mgmt(struct net *net, struct sctp_sockaddr_entry *addr, int cmd)
738 {
739 	struct sctp_sockaddr_entry *addrw;
740 	unsigned long timeo_val;
741 
742 	/* first, we check if an opposite message already exist in the queue.
743 	 * If we found such message, it is removed.
744 	 * This operation is a bit stupid, but the DHCP client attaches the
745 	 * new address after a couple of addition and deletion of that address
746 	 */
747 
748 	spin_lock_bh(&net->sctp.addr_wq_lock);
749 	/* Offsets existing events in addr_wq */
750 	addrw = sctp_addr_wq_lookup(net, addr);
751 	if (addrw) {
752 		if (addrw->state != cmd) {
753 			pr_debug("%s: offsets existing entry for %d, addr:%pISc "
754 				 "in wq:%p\n", __func__, addrw->state, &addrw->a.sa,
755 				 &net->sctp.addr_waitq);
756 
757 			list_del(&addrw->list);
758 			kfree(addrw);
759 		}
760 		spin_unlock_bh(&net->sctp.addr_wq_lock);
761 		return;
762 	}
763 
764 	/* OK, we have to add the new address to the wait queue */
765 	addrw = kmemdup(addr, sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
766 	if (addrw == NULL) {
767 		spin_unlock_bh(&net->sctp.addr_wq_lock);
768 		return;
769 	}
770 	addrw->state = cmd;
771 	list_add_tail(&addrw->list, &net->sctp.addr_waitq);
772 
773 	pr_debug("%s: add new entry for cmd:%d, addr:%pISc in wq:%p\n",
774 		 __func__, addrw->state, &addrw->a.sa, &net->sctp.addr_waitq);
775 
776 	if (!timer_pending(&net->sctp.addr_wq_timer)) {
777 		timeo_val = jiffies;
778 		timeo_val += msecs_to_jiffies(SCTP_ADDRESS_TICK_DELAY);
779 		mod_timer(&net->sctp.addr_wq_timer, timeo_val);
780 	}
781 	spin_unlock_bh(&net->sctp.addr_wq_lock);
782 }
783 
784 /* Event handler for inet address addition/deletion events.
785  * The sctp_local_addr_list needs to be protocted by a spin lock since
786  * multiple notifiers (say IPv4 and IPv6) may be running at the same
787  * time and thus corrupt the list.
788  * The reader side is protected with RCU.
789  */
sctp_inetaddr_event(struct notifier_block * this,unsigned long ev,void * ptr)790 static int sctp_inetaddr_event(struct notifier_block *this, unsigned long ev,
791 			       void *ptr)
792 {
793 	struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
794 	struct sctp_sockaddr_entry *addr = NULL;
795 	struct sctp_sockaddr_entry *temp;
796 	struct net *net = dev_net(ifa->ifa_dev->dev);
797 	int found = 0;
798 
799 	switch (ev) {
800 	case NETDEV_UP:
801 		addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
802 		if (addr) {
803 			addr->a.v4.sin_family = AF_INET;
804 			addr->a.v4.sin_addr.s_addr = ifa->ifa_local;
805 			addr->valid = 1;
806 			spin_lock_bh(&net->sctp.local_addr_lock);
807 			list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
808 			sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
809 			spin_unlock_bh(&net->sctp.local_addr_lock);
810 		}
811 		break;
812 	case NETDEV_DOWN:
813 		spin_lock_bh(&net->sctp.local_addr_lock);
814 		list_for_each_entry_safe(addr, temp,
815 					&net->sctp.local_addr_list, list) {
816 			if (addr->a.sa.sa_family == AF_INET &&
817 					addr->a.v4.sin_addr.s_addr ==
818 					ifa->ifa_local) {
819 				sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
820 				found = 1;
821 				addr->valid = 0;
822 				list_del_rcu(&addr->list);
823 				break;
824 			}
825 		}
826 		spin_unlock_bh(&net->sctp.local_addr_lock);
827 		if (found)
828 			kfree_rcu(addr, rcu);
829 		break;
830 	}
831 
832 	return NOTIFY_DONE;
833 }
834 
835 /*
836  * Initialize the control inode/socket with a control endpoint data
837  * structure.  This endpoint is reserved exclusively for the OOTB processing.
838  */
sctp_ctl_sock_init(struct net * net)839 static int sctp_ctl_sock_init(struct net *net)
840 {
841 	int err;
842 	sa_family_t family = PF_INET;
843 
844 	if (sctp_get_pf_specific(PF_INET6))
845 		family = PF_INET6;
846 
847 	err = inet_ctl_sock_create(&net->sctp.ctl_sock, family,
848 				   SOCK_SEQPACKET, IPPROTO_SCTP, net);
849 
850 	/* If IPv6 socket could not be created, try the IPv4 socket */
851 	if (err < 0 && family == PF_INET6)
852 		err = inet_ctl_sock_create(&net->sctp.ctl_sock, AF_INET,
853 					   SOCK_SEQPACKET, IPPROTO_SCTP,
854 					   net);
855 
856 	if (err < 0) {
857 		pr_err("Failed to create the SCTP control socket\n");
858 		return err;
859 	}
860 	return 0;
861 }
862 
863 /* Register address family specific functions. */
sctp_register_af(struct sctp_af * af)864 int sctp_register_af(struct sctp_af *af)
865 {
866 	switch (af->sa_family) {
867 	case AF_INET:
868 		if (sctp_af_v4_specific)
869 			return 0;
870 		sctp_af_v4_specific = af;
871 		break;
872 	case AF_INET6:
873 		if (sctp_af_v6_specific)
874 			return 0;
875 		sctp_af_v6_specific = af;
876 		break;
877 	default:
878 		return 0;
879 	}
880 
881 	INIT_LIST_HEAD(&af->list);
882 	list_add_tail(&af->list, &sctp_address_families);
883 	return 1;
884 }
885 
886 /* Get the table of functions for manipulating a particular address
887  * family.
888  */
sctp_get_af_specific(sa_family_t family)889 struct sctp_af *sctp_get_af_specific(sa_family_t family)
890 {
891 	switch (family) {
892 	case AF_INET:
893 		return sctp_af_v4_specific;
894 	case AF_INET6:
895 		return sctp_af_v6_specific;
896 	default:
897 		return NULL;
898 	}
899 }
900 
901 /* Common code to initialize a AF_INET msg_name. */
sctp_inet_msgname(char * msgname,int * addr_len)902 static void sctp_inet_msgname(char *msgname, int *addr_len)
903 {
904 	struct sockaddr_in *sin;
905 
906 	sin = (struct sockaddr_in *)msgname;
907 	*addr_len = sizeof(struct sockaddr_in);
908 	sin->sin_family = AF_INET;
909 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
910 }
911 
912 /* 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)913 static void sctp_inet_event_msgname(struct sctp_ulpevent *event, char *msgname,
914 				    int *addr_len)
915 {
916 	struct sockaddr_in *sin, *sinfrom;
917 
918 	if (msgname) {
919 		struct sctp_association *asoc;
920 
921 		asoc = event->asoc;
922 		sctp_inet_msgname(msgname, addr_len);
923 		sin = (struct sockaddr_in *)msgname;
924 		sinfrom = &asoc->peer.primary_addr.v4;
925 		sin->sin_port = htons(asoc->peer.port);
926 		sin->sin_addr.s_addr = sinfrom->sin_addr.s_addr;
927 	}
928 }
929 
930 /* Initialize and copy out a msgname from an inbound skb. */
sctp_inet_skb_msgname(struct sk_buff * skb,char * msgname,int * len)931 static void sctp_inet_skb_msgname(struct sk_buff *skb, char *msgname, int *len)
932 {
933 	if (msgname) {
934 		struct sctphdr *sh = sctp_hdr(skb);
935 		struct sockaddr_in *sin = (struct sockaddr_in *)msgname;
936 
937 		sctp_inet_msgname(msgname, len);
938 		sin->sin_port = sh->source;
939 		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
940 	}
941 }
942 
943 /* Do we support this AF? */
sctp_inet_af_supported(sa_family_t family,struct sctp_sock * sp)944 static int sctp_inet_af_supported(sa_family_t family, struct sctp_sock *sp)
945 {
946 	/* PF_INET only supports AF_INET addresses. */
947 	return AF_INET == family;
948 }
949 
950 /* Address matching with wildcards allowed. */
sctp_inet_cmp_addr(const union sctp_addr * addr1,const union sctp_addr * addr2,struct sctp_sock * opt)951 static int sctp_inet_cmp_addr(const union sctp_addr *addr1,
952 			      const union sctp_addr *addr2,
953 			      struct sctp_sock *opt)
954 {
955 	/* PF_INET only supports AF_INET addresses. */
956 	if (addr1->sa.sa_family != addr2->sa.sa_family)
957 		return 0;
958 	if (htonl(INADDR_ANY) == addr1->v4.sin_addr.s_addr ||
959 	    htonl(INADDR_ANY) == addr2->v4.sin_addr.s_addr)
960 		return 1;
961 	if (addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr)
962 		return 1;
963 
964 	return 0;
965 }
966 
967 /* Verify that provided sockaddr looks bindable.  Common verification has
968  * already been taken care of.
969  */
sctp_inet_bind_verify(struct sctp_sock * opt,union sctp_addr * addr)970 static int sctp_inet_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
971 {
972 	return sctp_v4_available(addr, opt);
973 }
974 
975 /* Verify that sockaddr looks sendable.  Common verification has already
976  * been taken care of.
977  */
sctp_inet_send_verify(struct sctp_sock * opt,union sctp_addr * addr)978 static int sctp_inet_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
979 {
980 	return 1;
981 }
982 
983 /* Fill in Supported Address Type information for INIT and INIT-ACK
984  * chunks.  Returns number of addresses supported.
985  */
sctp_inet_supported_addrs(const struct sctp_sock * opt,__be16 * types)986 static int sctp_inet_supported_addrs(const struct sctp_sock *opt,
987 				     __be16 *types)
988 {
989 	types[0] = SCTP_PARAM_IPV4_ADDRESS;
990 	return 1;
991 }
992 
993 /* Wrapper routine that calls the ip transmit routine. */
sctp_v4_xmit(struct sk_buff * skb,struct sctp_transport * transport)994 static inline int sctp_v4_xmit(struct sk_buff *skb,
995 			       struct sctp_transport *transport)
996 {
997 	struct inet_sock *inet = inet_sk(skb->sk);
998 	__u8 dscp = inet->tos;
999 
1000 	pr_debug("%s: skb:%p, len:%d, src:%pI4, dst:%pI4\n", __func__, skb,
1001 		 skb->len, &transport->fl.u.ip4.saddr,
1002 		 &transport->fl.u.ip4.daddr);
1003 
1004 	if (transport->dscp & SCTP_DSCP_SET_MASK)
1005 		dscp = transport->dscp & SCTP_DSCP_VAL_MASK;
1006 
1007 	inet->pmtudisc = transport->param_flags & SPP_PMTUD_ENABLE ?
1008 			 IP_PMTUDISC_DO : IP_PMTUDISC_DONT;
1009 
1010 	SCTP_INC_STATS(sock_net(&inet->sk), SCTP_MIB_OUTSCTPPACKS);
1011 
1012 	return __ip_queue_xmit(&inet->sk, skb, &transport->fl, dscp);
1013 }
1014 
1015 static struct sctp_af sctp_af_inet;
1016 
1017 static struct sctp_pf sctp_pf_inet = {
1018 	.event_msgname = sctp_inet_event_msgname,
1019 	.skb_msgname   = sctp_inet_skb_msgname,
1020 	.af_supported  = sctp_inet_af_supported,
1021 	.cmp_addr      = sctp_inet_cmp_addr,
1022 	.bind_verify   = sctp_inet_bind_verify,
1023 	.send_verify   = sctp_inet_send_verify,
1024 	.supported_addrs = sctp_inet_supported_addrs,
1025 	.create_accept_sk = sctp_v4_create_accept_sk,
1026 	.addr_to_user  = sctp_v4_addr_to_user,
1027 	.to_sk_saddr   = sctp_v4_to_sk_saddr,
1028 	.to_sk_daddr   = sctp_v4_to_sk_daddr,
1029 	.copy_ip_options = sctp_v4_copy_ip_options,
1030 	.af            = &sctp_af_inet
1031 };
1032 
1033 /* Notifier for inetaddr addition/deletion events.  */
1034 static struct notifier_block sctp_inetaddr_notifier = {
1035 	.notifier_call = sctp_inetaddr_event,
1036 };
1037 
1038 /* Socket operations.  */
1039 static const struct proto_ops inet_seqpacket_ops = {
1040 	.family		   = PF_INET,
1041 	.owner		   = THIS_MODULE,
1042 	.release	   = inet_release,	/* Needs to be wrapped... */
1043 	.bind		   = inet_bind,
1044 	.connect	   = sctp_inet_connect,
1045 	.socketpair	   = sock_no_socketpair,
1046 	.accept		   = inet_accept,
1047 	.getname	   = inet_getname,	/* Semantics are different.  */
1048 	.poll		   = sctp_poll,
1049 	.ioctl		   = inet_ioctl,
1050 	.listen		   = sctp_inet_listen,
1051 	.shutdown	   = inet_shutdown,	/* Looks harmless.  */
1052 	.setsockopt	   = sock_common_setsockopt, /* IP_SOL IP_OPTION is a problem */
1053 	.getsockopt	   = sock_common_getsockopt,
1054 	.sendmsg	   = inet_sendmsg,
1055 	.recvmsg	   = inet_recvmsg,
1056 	.mmap		   = sock_no_mmap,
1057 	.sendpage	   = sock_no_sendpage,
1058 #ifdef CONFIG_COMPAT
1059 	.compat_setsockopt = compat_sock_common_setsockopt,
1060 	.compat_getsockopt = compat_sock_common_getsockopt,
1061 #endif
1062 };
1063 
1064 /* Registration with AF_INET family.  */
1065 static struct inet_protosw sctp_seqpacket_protosw = {
1066 	.type       = SOCK_SEQPACKET,
1067 	.protocol   = IPPROTO_SCTP,
1068 	.prot       = &sctp_prot,
1069 	.ops        = &inet_seqpacket_ops,
1070 	.flags      = SCTP_PROTOSW_FLAG
1071 };
1072 static struct inet_protosw sctp_stream_protosw = {
1073 	.type       = SOCK_STREAM,
1074 	.protocol   = IPPROTO_SCTP,
1075 	.prot       = &sctp_prot,
1076 	.ops        = &inet_seqpacket_ops,
1077 	.flags      = SCTP_PROTOSW_FLAG
1078 };
1079 
1080 /* Register with IP layer.  */
1081 static const struct net_protocol sctp_protocol = {
1082 	.handler     = sctp_rcv,
1083 	.err_handler = sctp_v4_err,
1084 	.no_policy   = 1,
1085 	.netns_ok    = 1,
1086 	.icmp_strict_tag_validation = 1,
1087 };
1088 
1089 /* IPv4 address related functions.  */
1090 static struct sctp_af sctp_af_inet = {
1091 	.sa_family	   = AF_INET,
1092 	.sctp_xmit	   = sctp_v4_xmit,
1093 	.setsockopt	   = ip_setsockopt,
1094 	.getsockopt	   = ip_getsockopt,
1095 	.get_dst	   = sctp_v4_get_dst,
1096 	.get_saddr	   = sctp_v4_get_saddr,
1097 	.copy_addrlist	   = sctp_v4_copy_addrlist,
1098 	.from_skb	   = sctp_v4_from_skb,
1099 	.from_sk	   = sctp_v4_from_sk,
1100 	.from_addr_param   = sctp_v4_from_addr_param,
1101 	.to_addr_param	   = sctp_v4_to_addr_param,
1102 	.cmp_addr	   = sctp_v4_cmp_addr,
1103 	.addr_valid	   = sctp_v4_addr_valid,
1104 	.inaddr_any	   = sctp_v4_inaddr_any,
1105 	.is_any		   = sctp_v4_is_any,
1106 	.available	   = sctp_v4_available,
1107 	.scope		   = sctp_v4_scope,
1108 	.skb_iif	   = sctp_v4_skb_iif,
1109 	.is_ce		   = sctp_v4_is_ce,
1110 	.seq_dump_addr	   = sctp_v4_seq_dump_addr,
1111 	.ecn_capable	   = sctp_v4_ecn_capable,
1112 	.net_header_len	   = sizeof(struct iphdr),
1113 	.sockaddr_len	   = sizeof(struct sockaddr_in),
1114 	.ip_options_len	   = sctp_v4_ip_options_len,
1115 #ifdef CONFIG_COMPAT
1116 	.compat_setsockopt = compat_ip_setsockopt,
1117 	.compat_getsockopt = compat_ip_getsockopt,
1118 #endif
1119 };
1120 
sctp_get_pf_specific(sa_family_t family)1121 struct sctp_pf *sctp_get_pf_specific(sa_family_t family)
1122 {
1123 	switch (family) {
1124 	case PF_INET:
1125 		return sctp_pf_inet_specific;
1126 	case PF_INET6:
1127 		return sctp_pf_inet6_specific;
1128 	default:
1129 		return NULL;
1130 	}
1131 }
1132 
1133 /* Register the PF specific function table.  */
sctp_register_pf(struct sctp_pf * pf,sa_family_t family)1134 int sctp_register_pf(struct sctp_pf *pf, sa_family_t family)
1135 {
1136 	switch (family) {
1137 	case PF_INET:
1138 		if (sctp_pf_inet_specific)
1139 			return 0;
1140 		sctp_pf_inet_specific = pf;
1141 		break;
1142 	case PF_INET6:
1143 		if (sctp_pf_inet6_specific)
1144 			return 0;
1145 		sctp_pf_inet6_specific = pf;
1146 		break;
1147 	default:
1148 		return 0;
1149 	}
1150 	return 1;
1151 }
1152 
init_sctp_mibs(struct net * net)1153 static inline int init_sctp_mibs(struct net *net)
1154 {
1155 	net->sctp.sctp_statistics = alloc_percpu(struct sctp_mib);
1156 	if (!net->sctp.sctp_statistics)
1157 		return -ENOMEM;
1158 	return 0;
1159 }
1160 
cleanup_sctp_mibs(struct net * net)1161 static inline void cleanup_sctp_mibs(struct net *net)
1162 {
1163 	free_percpu(net->sctp.sctp_statistics);
1164 }
1165 
sctp_v4_pf_init(void)1166 static void sctp_v4_pf_init(void)
1167 {
1168 	/* Initialize the SCTP specific PF functions. */
1169 	sctp_register_pf(&sctp_pf_inet, PF_INET);
1170 	sctp_register_af(&sctp_af_inet);
1171 }
1172 
sctp_v4_pf_exit(void)1173 static void sctp_v4_pf_exit(void)
1174 {
1175 	list_del(&sctp_af_inet.list);
1176 }
1177 
sctp_v4_protosw_init(void)1178 static int sctp_v4_protosw_init(void)
1179 {
1180 	int rc;
1181 
1182 	rc = proto_register(&sctp_prot, 1);
1183 	if (rc)
1184 		return rc;
1185 
1186 	/* Register SCTP(UDP and TCP style) with socket layer.  */
1187 	inet_register_protosw(&sctp_seqpacket_protosw);
1188 	inet_register_protosw(&sctp_stream_protosw);
1189 
1190 	return 0;
1191 }
1192 
sctp_v4_protosw_exit(void)1193 static void sctp_v4_protosw_exit(void)
1194 {
1195 	inet_unregister_protosw(&sctp_stream_protosw);
1196 	inet_unregister_protosw(&sctp_seqpacket_protosw);
1197 	proto_unregister(&sctp_prot);
1198 }
1199 
sctp_v4_add_protocol(void)1200 static int sctp_v4_add_protocol(void)
1201 {
1202 	/* Register notifier for inet address additions/deletions. */
1203 	register_inetaddr_notifier(&sctp_inetaddr_notifier);
1204 
1205 	/* Register SCTP with inet layer.  */
1206 	if (inet_add_protocol(&sctp_protocol, IPPROTO_SCTP) < 0)
1207 		return -EAGAIN;
1208 
1209 	return 0;
1210 }
1211 
sctp_v4_del_protocol(void)1212 static void sctp_v4_del_protocol(void)
1213 {
1214 	inet_del_protocol(&sctp_protocol, IPPROTO_SCTP);
1215 	unregister_inetaddr_notifier(&sctp_inetaddr_notifier);
1216 }
1217 
sctp_defaults_init(struct net * net)1218 static int __net_init sctp_defaults_init(struct net *net)
1219 {
1220 	int status;
1221 
1222 	/*
1223 	 * 14. Suggested SCTP Protocol Parameter Values
1224 	 */
1225 	/* The following protocol parameters are RECOMMENDED:  */
1226 	/* RTO.Initial              - 3  seconds */
1227 	net->sctp.rto_initial			= SCTP_RTO_INITIAL;
1228 	/* RTO.Min                  - 1  second */
1229 	net->sctp.rto_min	 		= SCTP_RTO_MIN;
1230 	/* RTO.Max                 -  60 seconds */
1231 	net->sctp.rto_max 			= SCTP_RTO_MAX;
1232 	/* RTO.Alpha                - 1/8 */
1233 	net->sctp.rto_alpha			= SCTP_RTO_ALPHA;
1234 	/* RTO.Beta                 - 1/4 */
1235 	net->sctp.rto_beta			= SCTP_RTO_BETA;
1236 
1237 	/* Valid.Cookie.Life        - 60  seconds */
1238 	net->sctp.valid_cookie_life		= SCTP_DEFAULT_COOKIE_LIFE;
1239 
1240 	/* Whether Cookie Preservative is enabled(1) or not(0) */
1241 	net->sctp.cookie_preserve_enable 	= 1;
1242 
1243 	/* Default sctp sockets to use md5 as their hmac alg */
1244 #if defined (CONFIG_SCTP_DEFAULT_COOKIE_HMAC_MD5)
1245 	net->sctp.sctp_hmac_alg			= "md5";
1246 #elif defined (CONFIG_SCTP_DEFAULT_COOKIE_HMAC_SHA1)
1247 	net->sctp.sctp_hmac_alg			= "sha1";
1248 #else
1249 	net->sctp.sctp_hmac_alg			= NULL;
1250 #endif
1251 
1252 	/* Max.Burst		    - 4 */
1253 	net->sctp.max_burst			= SCTP_DEFAULT_MAX_BURST;
1254 
1255 	/* Enable pf state by default */
1256 	net->sctp.pf_enable = 1;
1257 
1258 	/* Association.Max.Retrans  - 10 attempts
1259 	 * Path.Max.Retrans         - 5  attempts (per destination address)
1260 	 * Max.Init.Retransmits     - 8  attempts
1261 	 */
1262 	net->sctp.max_retrans_association	= 10;
1263 	net->sctp.max_retrans_path		= 5;
1264 	net->sctp.max_retrans_init		= 8;
1265 
1266 	/* Sendbuffer growth	    - do per-socket accounting */
1267 	net->sctp.sndbuf_policy			= 0;
1268 
1269 	/* Rcvbuffer growth	    - do per-socket accounting */
1270 	net->sctp.rcvbuf_policy			= 0;
1271 
1272 	/* HB.interval              - 30 seconds */
1273 	net->sctp.hb_interval			= SCTP_DEFAULT_TIMEOUT_HEARTBEAT;
1274 
1275 	/* delayed SACK timeout */
1276 	net->sctp.sack_timeout			= SCTP_DEFAULT_TIMEOUT_SACK;
1277 
1278 	/* Disable ADDIP by default. */
1279 	net->sctp.addip_enable = 0;
1280 	net->sctp.addip_noauth = 0;
1281 	net->sctp.default_auto_asconf = 0;
1282 
1283 	/* Enable PR-SCTP by default. */
1284 	net->sctp.prsctp_enable = 1;
1285 
1286 	/* Disable RECONF by default. */
1287 	net->sctp.reconf_enable = 0;
1288 
1289 	/* Disable AUTH by default. */
1290 	net->sctp.auth_enable = 0;
1291 
1292 	/* Set SCOPE policy to enabled */
1293 	net->sctp.scope_policy = SCTP_SCOPE_POLICY_ENABLE;
1294 
1295 	/* Set the default rwnd update threshold */
1296 	net->sctp.rwnd_upd_shift = SCTP_DEFAULT_RWND_SHIFT;
1297 
1298 	/* Initialize maximum autoclose timeout. */
1299 	net->sctp.max_autoclose		= INT_MAX / HZ;
1300 
1301 	status = sctp_sysctl_net_register(net);
1302 	if (status)
1303 		goto err_sysctl_register;
1304 
1305 	/* Allocate and initialise sctp mibs.  */
1306 	status = init_sctp_mibs(net);
1307 	if (status)
1308 		goto err_init_mibs;
1309 
1310 #ifdef CONFIG_PROC_FS
1311 	/* Initialize proc fs directory.  */
1312 	status = sctp_proc_init(net);
1313 	if (status)
1314 		goto err_init_proc;
1315 #endif
1316 
1317 	sctp_dbg_objcnt_init(net);
1318 
1319 	/* Initialize the local address list. */
1320 	INIT_LIST_HEAD(&net->sctp.local_addr_list);
1321 	spin_lock_init(&net->sctp.local_addr_lock);
1322 	sctp_get_local_addr_list(net);
1323 
1324 	/* Initialize the address event list */
1325 	INIT_LIST_HEAD(&net->sctp.addr_waitq);
1326 	INIT_LIST_HEAD(&net->sctp.auto_asconf_splist);
1327 	spin_lock_init(&net->sctp.addr_wq_lock);
1328 	net->sctp.addr_wq_timer.expires = 0;
1329 	timer_setup(&net->sctp.addr_wq_timer, sctp_addr_wq_timeout_handler, 0);
1330 
1331 	return 0;
1332 
1333 #ifdef CONFIG_PROC_FS
1334 err_init_proc:
1335 	cleanup_sctp_mibs(net);
1336 #endif
1337 err_init_mibs:
1338 	sctp_sysctl_net_unregister(net);
1339 err_sysctl_register:
1340 	return status;
1341 }
1342 
sctp_defaults_exit(struct net * net)1343 static void __net_exit sctp_defaults_exit(struct net *net)
1344 {
1345 	/* Free the local address list */
1346 	sctp_free_addr_wq(net);
1347 	sctp_free_local_addr_list(net);
1348 
1349 #ifdef CONFIG_PROC_FS
1350 	remove_proc_subtree("sctp", net->proc_net);
1351 	net->sctp.proc_net_sctp = NULL;
1352 #endif
1353 	cleanup_sctp_mibs(net);
1354 	sctp_sysctl_net_unregister(net);
1355 }
1356 
1357 static struct pernet_operations sctp_defaults_ops = {
1358 	.init = sctp_defaults_init,
1359 	.exit = sctp_defaults_exit,
1360 };
1361 
sctp_ctrlsock_init(struct net * net)1362 static int __net_init sctp_ctrlsock_init(struct net *net)
1363 {
1364 	int status;
1365 
1366 	/* Initialize the control inode/socket for handling OOTB packets.  */
1367 	status = sctp_ctl_sock_init(net);
1368 	if (status)
1369 		pr_err("Failed to initialize the SCTP control sock\n");
1370 
1371 	return status;
1372 }
1373 
sctp_ctrlsock_exit(struct net * net)1374 static void __net_exit sctp_ctrlsock_exit(struct net *net)
1375 {
1376 	/* Free the control endpoint.  */
1377 	inet_ctl_sock_destroy(net->sctp.ctl_sock);
1378 }
1379 
1380 static struct pernet_operations sctp_ctrlsock_ops = {
1381 	.init = sctp_ctrlsock_init,
1382 	.exit = sctp_ctrlsock_exit,
1383 };
1384 
1385 /* Initialize the universe into something sensible.  */
sctp_init(void)1386 static __init int sctp_init(void)
1387 {
1388 	int i;
1389 	int status = -EINVAL;
1390 	unsigned long goal;
1391 	unsigned long limit;
1392 	int max_share;
1393 	int order;
1394 	int num_entries;
1395 	int max_entry_order;
1396 
1397 	sock_skb_cb_check_size(sizeof(struct sctp_ulpevent));
1398 
1399 	/* Allocate bind_bucket and chunk caches. */
1400 	status = -ENOBUFS;
1401 	sctp_bucket_cachep = kmem_cache_create("sctp_bind_bucket",
1402 					       sizeof(struct sctp_bind_bucket),
1403 					       0, SLAB_HWCACHE_ALIGN,
1404 					       NULL);
1405 	if (!sctp_bucket_cachep)
1406 		goto out;
1407 
1408 	sctp_chunk_cachep = kmem_cache_create("sctp_chunk",
1409 					       sizeof(struct sctp_chunk),
1410 					       0, SLAB_HWCACHE_ALIGN,
1411 					       NULL);
1412 	if (!sctp_chunk_cachep)
1413 		goto err_chunk_cachep;
1414 
1415 	status = percpu_counter_init(&sctp_sockets_allocated, 0, GFP_KERNEL);
1416 	if (status)
1417 		goto err_percpu_counter_init;
1418 
1419 	/* Implementation specific variables. */
1420 
1421 	/* Initialize default stream count setup information. */
1422 	sctp_max_instreams    		= SCTP_DEFAULT_INSTREAMS;
1423 	sctp_max_outstreams   		= SCTP_DEFAULT_OUTSTREAMS;
1424 
1425 	/* Initialize handle used for association ids. */
1426 	idr_init(&sctp_assocs_id);
1427 
1428 	limit = nr_free_buffer_pages() / 8;
1429 	limit = max(limit, 128UL);
1430 	sysctl_sctp_mem[0] = limit / 4 * 3;
1431 	sysctl_sctp_mem[1] = limit;
1432 	sysctl_sctp_mem[2] = sysctl_sctp_mem[0] * 2;
1433 
1434 	/* Set per-socket limits to no more than 1/128 the pressure threshold*/
1435 	limit = (sysctl_sctp_mem[1]) << (PAGE_SHIFT - 7);
1436 	max_share = min(4UL*1024*1024, limit);
1437 
1438 	sysctl_sctp_rmem[0] = SK_MEM_QUANTUM; /* give each asoc 1 page min */
1439 	sysctl_sctp_rmem[1] = 1500 * SKB_TRUESIZE(1);
1440 	sysctl_sctp_rmem[2] = max(sysctl_sctp_rmem[1], max_share);
1441 
1442 	sysctl_sctp_wmem[0] = SK_MEM_QUANTUM;
1443 	sysctl_sctp_wmem[1] = 16*1024;
1444 	sysctl_sctp_wmem[2] = max(64*1024, max_share);
1445 
1446 	/* Size and allocate the association hash table.
1447 	 * The methodology is similar to that of the tcp hash tables.
1448 	 * Though not identical.  Start by getting a goal size
1449 	 */
1450 	if (totalram_pages >= (128 * 1024))
1451 		goal = totalram_pages >> (22 - PAGE_SHIFT);
1452 	else
1453 		goal = totalram_pages >> (24 - PAGE_SHIFT);
1454 
1455 	/* Then compute the page order for said goal */
1456 	order = get_order(goal);
1457 
1458 	/* Now compute the required page order for the maximum sized table we
1459 	 * want to create
1460 	 */
1461 	max_entry_order = get_order(MAX_SCTP_PORT_HASH_ENTRIES *
1462 				    sizeof(struct sctp_bind_hashbucket));
1463 
1464 	/* Limit the page order by that maximum hash table size */
1465 	order = min(order, max_entry_order);
1466 
1467 	/* Allocate and initialize the endpoint hash table.  */
1468 	sctp_ep_hashsize = 64;
1469 	sctp_ep_hashtable =
1470 		kmalloc_array(64, sizeof(struct sctp_hashbucket), GFP_KERNEL);
1471 	if (!sctp_ep_hashtable) {
1472 		pr_err("Failed endpoint_hash alloc\n");
1473 		status = -ENOMEM;
1474 		goto err_ehash_alloc;
1475 	}
1476 	for (i = 0; i < sctp_ep_hashsize; i++) {
1477 		rwlock_init(&sctp_ep_hashtable[i].lock);
1478 		INIT_HLIST_HEAD(&sctp_ep_hashtable[i].chain);
1479 	}
1480 
1481 	/* Allocate and initialize the SCTP port hash table.
1482 	 * Note that order is initalized to start at the max sized
1483 	 * table we want to support.  If we can't get that many pages
1484 	 * reduce the order and try again
1485 	 */
1486 	do {
1487 		sctp_port_hashtable = (struct sctp_bind_hashbucket *)
1488 			__get_free_pages(GFP_KERNEL | __GFP_NOWARN, order);
1489 	} while (!sctp_port_hashtable && --order > 0);
1490 
1491 	if (!sctp_port_hashtable) {
1492 		pr_err("Failed bind hash alloc\n");
1493 		status = -ENOMEM;
1494 		goto err_bhash_alloc;
1495 	}
1496 
1497 	/* Now compute the number of entries that will fit in the
1498 	 * port hash space we allocated
1499 	 */
1500 	num_entries = (1UL << order) * PAGE_SIZE /
1501 		      sizeof(struct sctp_bind_hashbucket);
1502 
1503 	/* And finish by rounding it down to the nearest power of two
1504 	 * this wastes some memory of course, but its needed because
1505 	 * the hash function operates based on the assumption that
1506 	 * that the number of entries is a power of two
1507 	 */
1508 	sctp_port_hashsize = rounddown_pow_of_two(num_entries);
1509 
1510 	for (i = 0; i < sctp_port_hashsize; i++) {
1511 		spin_lock_init(&sctp_port_hashtable[i].lock);
1512 		INIT_HLIST_HEAD(&sctp_port_hashtable[i].chain);
1513 	}
1514 
1515 	status = sctp_transport_hashtable_init();
1516 	if (status)
1517 		goto err_thash_alloc;
1518 
1519 	pr_info("Hash tables configured (bind %d/%d)\n", sctp_port_hashsize,
1520 		num_entries);
1521 
1522 	sctp_sysctl_register();
1523 
1524 	INIT_LIST_HEAD(&sctp_address_families);
1525 	sctp_v4_pf_init();
1526 	sctp_v6_pf_init();
1527 	sctp_sched_ops_init();
1528 
1529 	status = register_pernet_subsys(&sctp_defaults_ops);
1530 	if (status)
1531 		goto err_register_defaults;
1532 
1533 	status = sctp_v4_protosw_init();
1534 	if (status)
1535 		goto err_protosw_init;
1536 
1537 	status = sctp_v6_protosw_init();
1538 	if (status)
1539 		goto err_v6_protosw_init;
1540 
1541 	status = register_pernet_subsys(&sctp_ctrlsock_ops);
1542 	if (status)
1543 		goto err_register_ctrlsock;
1544 
1545 	status = sctp_v4_add_protocol();
1546 	if (status)
1547 		goto err_add_protocol;
1548 
1549 	/* Register SCTP with inet6 layer.  */
1550 	status = sctp_v6_add_protocol();
1551 	if (status)
1552 		goto err_v6_add_protocol;
1553 
1554 	if (sctp_offload_init() < 0)
1555 		pr_crit("%s: Cannot add SCTP protocol offload\n", __func__);
1556 
1557 out:
1558 	return status;
1559 err_v6_add_protocol:
1560 	sctp_v4_del_protocol();
1561 err_add_protocol:
1562 	unregister_pernet_subsys(&sctp_ctrlsock_ops);
1563 err_register_ctrlsock:
1564 	sctp_v6_protosw_exit();
1565 err_v6_protosw_init:
1566 	sctp_v4_protosw_exit();
1567 err_protosw_init:
1568 	unregister_pernet_subsys(&sctp_defaults_ops);
1569 err_register_defaults:
1570 	sctp_v4_pf_exit();
1571 	sctp_v6_pf_exit();
1572 	sctp_sysctl_unregister();
1573 	free_pages((unsigned long)sctp_port_hashtable,
1574 		   get_order(sctp_port_hashsize *
1575 			     sizeof(struct sctp_bind_hashbucket)));
1576 err_bhash_alloc:
1577 	sctp_transport_hashtable_destroy();
1578 err_thash_alloc:
1579 	kfree(sctp_ep_hashtable);
1580 err_ehash_alloc:
1581 	percpu_counter_destroy(&sctp_sockets_allocated);
1582 err_percpu_counter_init:
1583 	kmem_cache_destroy(sctp_chunk_cachep);
1584 err_chunk_cachep:
1585 	kmem_cache_destroy(sctp_bucket_cachep);
1586 	goto out;
1587 }
1588 
1589 /* Exit handler for the SCTP protocol.  */
sctp_exit(void)1590 static __exit void sctp_exit(void)
1591 {
1592 	/* BUG.  This should probably do something useful like clean
1593 	 * up all the remaining associations and all that memory.
1594 	 */
1595 
1596 	/* Unregister with inet6/inet layers. */
1597 	sctp_v6_del_protocol();
1598 	sctp_v4_del_protocol();
1599 
1600 	unregister_pernet_subsys(&sctp_ctrlsock_ops);
1601 
1602 	/* Free protosw registrations */
1603 	sctp_v6_protosw_exit();
1604 	sctp_v4_protosw_exit();
1605 
1606 	unregister_pernet_subsys(&sctp_defaults_ops);
1607 
1608 	/* Unregister with socket layer. */
1609 	sctp_v6_pf_exit();
1610 	sctp_v4_pf_exit();
1611 
1612 	sctp_sysctl_unregister();
1613 
1614 	free_pages((unsigned long)sctp_port_hashtable,
1615 		   get_order(sctp_port_hashsize *
1616 			     sizeof(struct sctp_bind_hashbucket)));
1617 	kfree(sctp_ep_hashtable);
1618 	sctp_transport_hashtable_destroy();
1619 
1620 	percpu_counter_destroy(&sctp_sockets_allocated);
1621 
1622 	rcu_barrier(); /* Wait for completion of call_rcu()'s */
1623 
1624 	kmem_cache_destroy(sctp_chunk_cachep);
1625 	kmem_cache_destroy(sctp_bucket_cachep);
1626 }
1627 
1628 module_init(sctp_init);
1629 module_exit(sctp_exit);
1630 
1631 /*
1632  * __stringify doesn't likes enums, so use IPPROTO_SCTP value (132) directly.
1633  */
1634 MODULE_ALIAS("net-pf-" __stringify(PF_INET) "-proto-132");
1635 MODULE_ALIAS("net-pf-" __stringify(PF_INET6) "-proto-132");
1636 MODULE_AUTHOR("Linux Kernel SCTP developers <linux-sctp@vger.kernel.org>");
1637 MODULE_DESCRIPTION("Support for the SCTP protocol (RFC2960)");
1638 module_param_named(no_checksums, sctp_checksum_disable, bool, 0644);
1639 MODULE_PARM_DESC(no_checksums, "Disable checksums computing and verification");
1640 MODULE_LICENSE("GPL");
1641