• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* SCTP kernel implementation
3  * (C) Copyright IBM Corp. 2001, 2004
4  * Copyright (c) 1999-2000 Cisco, Inc.
5  * Copyright (c) 1999-2001 Motorola, Inc.
6  * Copyright (c) 2001 Intel Corp.
7  * Copyright (c) 2001 Nokia, Inc.
8  * Copyright (c) 2001 La Monte H.P. Yarroll
9  *
10  * This file is part of the SCTP kernel implementation
11  *
12  * Initialization/cleanup for SCTP protocol support.
13  *
14  * Please send any bug reports or fixes you make to the
15  * email address(es):
16  *    lksctp developers <linux-sctp@vger.kernel.org>
17  *
18  * Written or modified by:
19  *    La Monte H.P. Yarroll <piggy@acm.org>
20  *    Karl Knutson <karl@athena.chicago.il.us>
21  *    Jon Grimm <jgrimm@us.ibm.com>
22  *    Sridhar Samudrala <sri@us.ibm.com>
23  *    Daisy Chang <daisyc@us.ibm.com>
24  *    Ardelle Fan <ardelle.fan@intel.com>
25  */
26 
27 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
28 
29 #include <linux/module.h>
30 #include <linux/init.h>
31 #include <linux/netdevice.h>
32 #include <linux/inetdevice.h>
33 #include <linux/seq_file.h>
34 #include <linux/memblock.h>
35 #include <linux/highmem.h>
36 #include <linux/swap.h>
37 #include <linux/slab.h>
38 #include <net/net_namespace.h>
39 #include <net/protocol.h>
40 #include <net/ip.h>
41 #include <net/ipv6.h>
42 #include <net/route.h>
43 #include <net/sctp/sctp.h>
44 #include <net/addrconf.h>
45 #include <net/inet_common.h>
46 #include <net/inet_ecn.h>
47 
48 #define MAX_SCTP_PORT_HASH_ENTRIES (64 * 1024)
49 
50 /* Global data structures. */
51 struct sctp_globals sctp_globals __read_mostly;
52 
53 struct idr sctp_assocs_id;
54 DEFINE_SPINLOCK(sctp_assocs_id_lock);
55 
56 static struct sctp_pf *sctp_pf_inet6_specific;
57 static struct sctp_pf *sctp_pf_inet_specific;
58 static struct sctp_af *sctp_af_v4_specific;
59 static struct sctp_af *sctp_af_v6_specific;
60 
61 struct kmem_cache *sctp_chunk_cachep __read_mostly;
62 struct kmem_cache *sctp_bucket_cachep __read_mostly;
63 
64 long sysctl_sctp_mem[3];
65 int sysctl_sctp_rmem[3];
66 int sysctl_sctp_wmem[3];
67 
68 /* Private helper to extract ipv4 address and stash them in
69  * the protocol structure.
70  */
sctp_v4_copy_addrlist(struct list_head * addrlist,struct net_device * dev)71 static void sctp_v4_copy_addrlist(struct list_head *addrlist,
72 				  struct net_device *dev)
73 {
74 	struct in_device *in_dev;
75 	struct in_ifaddr *ifa;
76 	struct sctp_sockaddr_entry *addr;
77 
78 	rcu_read_lock();
79 	if ((in_dev = __in_dev_get_rcu(dev)) == NULL) {
80 		rcu_read_unlock();
81 		return;
82 	}
83 
84 	in_dev_for_each_ifa_rcu(ifa, in_dev) {
85 		/* Add the address to the local list.  */
86 		addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
87 		if (addr) {
88 			addr->a.v4.sin_family = AF_INET;
89 			addr->a.v4.sin_addr.s_addr = ifa->ifa_local;
90 			addr->valid = 1;
91 			INIT_LIST_HEAD(&addr->list);
92 			list_add_tail(&addr->list, addrlist);
93 		}
94 	}
95 
96 	rcu_read_unlock();
97 }
98 
99 /* Extract our IP addresses from the system and stash them in the
100  * protocol structure.
101  */
sctp_get_local_addr_list(struct net * net)102 static void sctp_get_local_addr_list(struct net *net)
103 {
104 	struct net_device *dev;
105 	struct list_head *pos;
106 	struct sctp_af *af;
107 
108 	rcu_read_lock();
109 	for_each_netdev_rcu(net, dev) {
110 		list_for_each(pos, &sctp_address_families) {
111 			af = list_entry(pos, struct sctp_af, list);
112 			af->copy_addrlist(&net->sctp.local_addr_list, dev);
113 		}
114 	}
115 	rcu_read_unlock();
116 }
117 
118 /* Free the existing local addresses.  */
sctp_free_local_addr_list(struct net * net)119 static void sctp_free_local_addr_list(struct net *net)
120 {
121 	struct sctp_sockaddr_entry *addr;
122 	struct list_head *pos, *temp;
123 
124 	list_for_each_safe(pos, temp, &net->sctp.local_addr_list) {
125 		addr = list_entry(pos, struct sctp_sockaddr_entry, list);
126 		list_del(pos);
127 		kfree(addr);
128 	}
129 }
130 
131 /* Copy the local addresses which are valid for 'scope' into 'bp'.  */
sctp_copy_local_addr_list(struct net * net,struct sctp_bind_addr * bp,enum sctp_scope scope,gfp_t gfp,int copy_flags)132 int sctp_copy_local_addr_list(struct net *net, struct sctp_bind_addr *bp,
133 			      enum sctp_scope scope, gfp_t gfp, int copy_flags)
134 {
135 	struct sctp_sockaddr_entry *addr;
136 	union sctp_addr laddr;
137 	int error = 0;
138 
139 	rcu_read_lock();
140 	list_for_each_entry_rcu(addr, &net->sctp.local_addr_list, list) {
141 		if (!addr->valid)
142 			continue;
143 		if (!sctp_in_scope(net, &addr->a, scope))
144 			continue;
145 
146 		/* Now that the address is in scope, check to see if
147 		 * the address type is really supported by the local
148 		 * sock as well as the remote peer.
149 		 */
150 		if (addr->a.sa.sa_family == AF_INET &&
151 		    (!(copy_flags & SCTP_ADDR4_ALLOWED) ||
152 		     !(copy_flags & SCTP_ADDR4_PEERSUPP)))
153 			continue;
154 		if (addr->a.sa.sa_family == AF_INET6 &&
155 		    (!(copy_flags & SCTP_ADDR6_ALLOWED) ||
156 		     !(copy_flags & SCTP_ADDR6_PEERSUPP)))
157 			continue;
158 
159 		laddr = addr->a;
160 		/* also works for setting ipv6 address port */
161 		laddr.v4.sin_port = htons(bp->port);
162 		if (sctp_bind_addr_state(bp, &laddr) != -1)
163 			continue;
164 
165 		error = sctp_add_bind_addr(bp, &addr->a, sizeof(addr->a),
166 					   SCTP_ADDR_SRC, GFP_ATOMIC);
167 		if (error)
168 			break;
169 	}
170 
171 	rcu_read_unlock();
172 	return error;
173 }
174 
175 /* Copy over any ip options */
sctp_v4_copy_ip_options(struct sock * sk,struct sock * newsk)176 static void sctp_v4_copy_ip_options(struct sock *sk, struct sock *newsk)
177 {
178 	struct inet_sock *newinet, *inet = inet_sk(sk);
179 	struct ip_options_rcu *inet_opt, *newopt = NULL;
180 
181 	newinet = inet_sk(newsk);
182 
183 	rcu_read_lock();
184 	inet_opt = rcu_dereference(inet->inet_opt);
185 	if (inet_opt) {
186 		newopt = sock_kmalloc(newsk, sizeof(*inet_opt) +
187 				      inet_opt->opt.optlen, GFP_ATOMIC);
188 		if (newopt)
189 			memcpy(newopt, inet_opt, sizeof(*inet_opt) +
190 			       inet_opt->opt.optlen);
191 		else
192 			pr_err("%s: Failed to copy ip options\n", __func__);
193 	}
194 	RCU_INIT_POINTER(newinet->inet_opt, newopt);
195 	rcu_read_unlock();
196 }
197 
198 /* Account for the IP options */
sctp_v4_ip_options_len(struct sock * sk)199 static int sctp_v4_ip_options_len(struct sock *sk)
200 {
201 	struct inet_sock *inet = inet_sk(sk);
202 	struct ip_options_rcu *inet_opt;
203 	int len = 0;
204 
205 	rcu_read_lock();
206 	inet_opt = rcu_dereference(inet->inet_opt);
207 	if (inet_opt)
208 		len = inet_opt->opt.optlen;
209 
210 	rcu_read_unlock();
211 	return len;
212 }
213 
214 /* Initialize a sctp_addr from in incoming skb.  */
sctp_v4_from_skb(union sctp_addr * addr,struct sk_buff * skb,int is_saddr)215 static void sctp_v4_from_skb(union sctp_addr *addr, struct sk_buff *skb,
216 			     int is_saddr)
217 {
218 	/* Always called on head skb, so this is safe */
219 	struct sctphdr *sh = sctp_hdr(skb);
220 	struct sockaddr_in *sa = &addr->v4;
221 
222 	addr->v4.sin_family = AF_INET;
223 
224 	if (is_saddr) {
225 		sa->sin_port = sh->source;
226 		sa->sin_addr.s_addr = ip_hdr(skb)->saddr;
227 	} else {
228 		sa->sin_port = sh->dest;
229 		sa->sin_addr.s_addr = ip_hdr(skb)->daddr;
230 	}
231 	memset(sa->sin_zero, 0, sizeof(sa->sin_zero));
232 }
233 
234 /* Initialize an sctp_addr from a socket. */
sctp_v4_from_sk(union sctp_addr * addr,struct sock * sk)235 static void sctp_v4_from_sk(union sctp_addr *addr, struct sock *sk)
236 {
237 	addr->v4.sin_family = AF_INET;
238 	addr->v4.sin_port = 0;
239 	addr->v4.sin_addr.s_addr = inet_sk(sk)->inet_rcv_saddr;
240 	memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
241 }
242 
243 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
sctp_v4_to_sk_saddr(union sctp_addr * addr,struct sock * sk)244 static void sctp_v4_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
245 {
246 	inet_sk(sk)->inet_rcv_saddr = addr->v4.sin_addr.s_addr;
247 }
248 
249 /* Initialize sk->sk_daddr from sctp_addr. */
sctp_v4_to_sk_daddr(union sctp_addr * addr,struct sock * sk)250 static void sctp_v4_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
251 {
252 	inet_sk(sk)->inet_daddr = addr->v4.sin_addr.s_addr;
253 }
254 
255 /* 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)256 static bool sctp_v4_from_addr_param(union sctp_addr *addr,
257 				    union sctp_addr_param *param,
258 				    __be16 port, int iif)
259 {
260 	if (ntohs(param->v4.param_hdr.length) < sizeof(struct sctp_ipv4addr_param))
261 		return false;
262 
263 	addr->v4.sin_family = AF_INET;
264 	addr->v4.sin_port = port;
265 	addr->v4.sin_addr.s_addr = param->v4.addr.s_addr;
266 	memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
267 
268 	return true;
269 }
270 
271 /* Initialize an address parameter from a sctp_addr and return the length
272  * of the address parameter.
273  */
sctp_v4_to_addr_param(const union sctp_addr * addr,union sctp_addr_param * param)274 static int sctp_v4_to_addr_param(const union sctp_addr *addr,
275 				 union sctp_addr_param *param)
276 {
277 	int length = sizeof(struct sctp_ipv4addr_param);
278 
279 	param->v4.param_hdr.type = SCTP_PARAM_IPV4_ADDRESS;
280 	param->v4.param_hdr.length = htons(length);
281 	param->v4.addr.s_addr = addr->v4.sin_addr.s_addr;
282 
283 	return length;
284 }
285 
286 /* Initialize a sctp_addr from a dst_entry. */
sctp_v4_dst_saddr(union sctp_addr * saddr,struct flowi4 * fl4,__be16 port)287 static void sctp_v4_dst_saddr(union sctp_addr *saddr, struct flowi4 *fl4,
288 			      __be16 port)
289 {
290 	saddr->v4.sin_family = AF_INET;
291 	saddr->v4.sin_port = port;
292 	saddr->v4.sin_addr.s_addr = fl4->saddr;
293 	memset(saddr->v4.sin_zero, 0, sizeof(saddr->v4.sin_zero));
294 }
295 
296 /* Compare two addresses exactly. */
sctp_v4_cmp_addr(const union sctp_addr * addr1,const union sctp_addr * addr2)297 static int sctp_v4_cmp_addr(const union sctp_addr *addr1,
298 			    const union sctp_addr *addr2)
299 {
300 	if (addr1->sa.sa_family != addr2->sa.sa_family)
301 		return 0;
302 	if (addr1->v4.sin_port != addr2->v4.sin_port)
303 		return 0;
304 	if (addr1->v4.sin_addr.s_addr != addr2->v4.sin_addr.s_addr)
305 		return 0;
306 
307 	return 1;
308 }
309 
310 /* Initialize addr struct to INADDR_ANY. */
sctp_v4_inaddr_any(union sctp_addr * addr,__be16 port)311 static void sctp_v4_inaddr_any(union sctp_addr *addr, __be16 port)
312 {
313 	addr->v4.sin_family = AF_INET;
314 	addr->v4.sin_addr.s_addr = htonl(INADDR_ANY);
315 	addr->v4.sin_port = port;
316 	memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
317 }
318 
319 /* Is this a wildcard address? */
sctp_v4_is_any(const union sctp_addr * addr)320 static int sctp_v4_is_any(const union sctp_addr *addr)
321 {
322 	return htonl(INADDR_ANY) == addr->v4.sin_addr.s_addr;
323 }
324 
325 /* This function checks if the address is a valid address to be used for
326  * SCTP binding.
327  *
328  * Output:
329  * Return 0 - If the address is a non-unicast or an illegal address.
330  * Return 1 - If the address is a unicast.
331  */
sctp_v4_addr_valid(union sctp_addr * addr,struct sctp_sock * sp,const struct sk_buff * skb)332 static int sctp_v4_addr_valid(union sctp_addr *addr,
333 			      struct sctp_sock *sp,
334 			      const struct sk_buff *skb)
335 {
336 	/* IPv4 addresses not allowed */
337 	if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
338 		return 0;
339 
340 	/* Is this a non-unicast address or a unusable SCTP address? */
341 	if (IS_IPV4_UNUSABLE_ADDRESS(addr->v4.sin_addr.s_addr))
342 		return 0;
343 
344 	/* Is this a broadcast address? */
345 	if (skb && skb_rtable(skb)->rt_flags & RTCF_BROADCAST)
346 		return 0;
347 
348 	return 1;
349 }
350 
351 /* Should this be available for binding?   */
sctp_v4_available(union sctp_addr * addr,struct sctp_sock * sp)352 static int sctp_v4_available(union sctp_addr *addr, struct sctp_sock *sp)
353 {
354 	struct net *net = sock_net(&sp->inet.sk);
355 	int ret = inet_addr_type(net, addr->v4.sin_addr.s_addr);
356 
357 
358 	if (addr->v4.sin_addr.s_addr != htonl(INADDR_ANY) &&
359 	   ret != RTN_LOCAL &&
360 	   !sp->inet.freebind &&
361 	    !READ_ONCE(net->ipv4.sysctl_ip_nonlocal_bind))
362 		return 0;
363 
364 	if (ipv6_only_sock(sctp_opt2sk(sp)))
365 		return 0;
366 
367 	return 1;
368 }
369 
370 /* Checking the loopback, private and other address scopes as defined in
371  * RFC 1918.   The IPv4 scoping is based on the draft for SCTP IPv4
372  * scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>.
373  *
374  * Level 0 - unusable SCTP addresses
375  * Level 1 - loopback address
376  * Level 2 - link-local addresses
377  * Level 3 - private addresses.
378  * Level 4 - global addresses
379  * For INIT and INIT-ACK address list, let L be the level of
380  * requested destination address, sender and receiver
381  * SHOULD include all of its addresses with level greater
382  * than or equal to L.
383  *
384  * IPv4 scoping can be controlled through sysctl option
385  * net.sctp.addr_scope_policy
386  */
sctp_v4_scope(union sctp_addr * addr)387 static enum sctp_scope sctp_v4_scope(union sctp_addr *addr)
388 {
389 	enum sctp_scope retval;
390 
391 	/* Check for unusable SCTP addresses. */
392 	if (IS_IPV4_UNUSABLE_ADDRESS(addr->v4.sin_addr.s_addr)) {
393 		retval =  SCTP_SCOPE_UNUSABLE;
394 	} else if (ipv4_is_loopback(addr->v4.sin_addr.s_addr)) {
395 		retval = SCTP_SCOPE_LOOPBACK;
396 	} else if (ipv4_is_linklocal_169(addr->v4.sin_addr.s_addr)) {
397 		retval = SCTP_SCOPE_LINK;
398 	} else if (ipv4_is_private_10(addr->v4.sin_addr.s_addr) ||
399 		   ipv4_is_private_172(addr->v4.sin_addr.s_addr) ||
400 		   ipv4_is_private_192(addr->v4.sin_addr.s_addr) ||
401 		   ipv4_is_test_198(addr->v4.sin_addr.s_addr)) {
402 		retval = SCTP_SCOPE_PRIVATE;
403 	} else {
404 		retval = SCTP_SCOPE_GLOBAL;
405 	}
406 
407 	return retval;
408 }
409 
410 /* Returns a valid dst cache entry for the given source and destination ip
411  * addresses. If an association is passed, trys to get a dst entry with a
412  * source address that matches an address in the bind address list.
413  */
sctp_v4_get_dst(struct sctp_transport * t,union sctp_addr * saddr,struct flowi * fl,struct sock * sk)414 static void sctp_v4_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
415 				struct flowi *fl, struct sock *sk)
416 {
417 	struct sctp_association *asoc = t->asoc;
418 	struct rtable *rt;
419 	struct flowi _fl;
420 	struct flowi4 *fl4 = &_fl.u.ip4;
421 	struct sctp_bind_addr *bp;
422 	struct sctp_sockaddr_entry *laddr;
423 	struct dst_entry *dst = NULL;
424 	union sctp_addr *daddr = &t->ipaddr;
425 	union sctp_addr dst_saddr;
426 	__u8 tos = inet_sk(sk)->tos;
427 
428 	if (t->dscp & SCTP_DSCP_SET_MASK)
429 		tos = t->dscp & SCTP_DSCP_VAL_MASK;
430 	memset(&_fl, 0x0, sizeof(_fl));
431 	fl4->daddr  = daddr->v4.sin_addr.s_addr;
432 	fl4->fl4_dport = daddr->v4.sin_port;
433 	fl4->flowi4_proto = IPPROTO_SCTP;
434 	if (asoc) {
435 		fl4->flowi4_tos = RT_CONN_FLAGS_TOS(asoc->base.sk, tos);
436 		fl4->flowi4_oif = asoc->base.sk->sk_bound_dev_if;
437 		fl4->fl4_sport = htons(asoc->base.bind_addr.port);
438 	}
439 	if (saddr) {
440 		fl4->saddr = saddr->v4.sin_addr.s_addr;
441 		if (!fl4->fl4_sport)
442 			fl4->fl4_sport = saddr->v4.sin_port;
443 	}
444 
445 	pr_debug("%s: dst:%pI4, src:%pI4 - ", __func__, &fl4->daddr,
446 		 &fl4->saddr);
447 
448 	rt = ip_route_output_key(sock_net(sk), fl4);
449 	if (!IS_ERR(rt)) {
450 		dst = &rt->dst;
451 		t->dst = dst;
452 		memcpy(fl, &_fl, sizeof(_fl));
453 	}
454 
455 	/* If there is no association or if a source address is passed, no
456 	 * more validation is required.
457 	 */
458 	if (!asoc || saddr)
459 		goto out;
460 
461 	bp = &asoc->base.bind_addr;
462 
463 	if (dst) {
464 		/* Walk through the bind address list and look for a bind
465 		 * address that matches the source address of the returned dst.
466 		 */
467 		sctp_v4_dst_saddr(&dst_saddr, fl4, htons(bp->port));
468 		rcu_read_lock();
469 		list_for_each_entry_rcu(laddr, &bp->address_list, list) {
470 			if (!laddr->valid || (laddr->state == SCTP_ADDR_DEL) ||
471 			    (laddr->state != SCTP_ADDR_SRC &&
472 			    !asoc->src_out_of_asoc_ok))
473 				continue;
474 			if (sctp_v4_cmp_addr(&dst_saddr, &laddr->a))
475 				goto out_unlock;
476 		}
477 		rcu_read_unlock();
478 
479 		/* None of the bound addresses match the source address of the
480 		 * dst. So release it.
481 		 */
482 		dst_release(dst);
483 		dst = NULL;
484 	}
485 
486 	/* Walk through the bind address list and try to get a dst that
487 	 * matches a bind address as the source address.
488 	 */
489 	rcu_read_lock();
490 	list_for_each_entry_rcu(laddr, &bp->address_list, list) {
491 		struct net_device *odev;
492 
493 		if (!laddr->valid)
494 			continue;
495 		if (laddr->state != SCTP_ADDR_SRC ||
496 		    AF_INET != laddr->a.sa.sa_family)
497 			continue;
498 
499 		fl4->fl4_sport = laddr->a.v4.sin_port;
500 		flowi4_update_output(fl4,
501 				     asoc->base.sk->sk_bound_dev_if,
502 				     RT_CONN_FLAGS_TOS(asoc->base.sk, tos),
503 				     daddr->v4.sin_addr.s_addr,
504 				     laddr->a.v4.sin_addr.s_addr);
505 
506 		rt = ip_route_output_key(sock_net(sk), fl4);
507 		if (IS_ERR(rt))
508 			continue;
509 
510 		/* Ensure the src address belongs to the output
511 		 * interface.
512 		 */
513 		odev = __ip_dev_find(sock_net(sk), laddr->a.v4.sin_addr.s_addr,
514 				     false);
515 		if (!odev || odev->ifindex != fl4->flowi4_oif) {
516 			if (!dst) {
517 				dst = &rt->dst;
518 				t->dst = dst;
519 				memcpy(fl, &_fl, sizeof(_fl));
520 			} else {
521 				dst_release(&rt->dst);
522 			}
523 			continue;
524 		}
525 
526 		dst_release(dst);
527 		dst = &rt->dst;
528 		t->dst = dst;
529 		memcpy(fl, &_fl, sizeof(_fl));
530 		break;
531 	}
532 
533 out_unlock:
534 	rcu_read_unlock();
535 out:
536 	if (dst) {
537 		pr_debug("rt_dst:%pI4, rt_src:%pI4\n",
538 			 &fl->u.ip4.daddr, &fl->u.ip4.saddr);
539 	} else {
540 		t->dst = NULL;
541 		pr_debug("no route\n");
542 	}
543 }
544 
545 /* For v4, the source address is cached in the route entry(dst). So no need
546  * to cache it separately and hence this is an empty routine.
547  */
sctp_v4_get_saddr(struct sctp_sock * sk,struct sctp_transport * t,struct flowi * fl)548 static void sctp_v4_get_saddr(struct sctp_sock *sk,
549 			      struct sctp_transport *t,
550 			      struct flowi *fl)
551 {
552 	union sctp_addr *saddr = &t->saddr;
553 	struct rtable *rt = (struct rtable *)t->dst;
554 
555 	if (rt) {
556 		saddr->v4.sin_family = AF_INET;
557 		saddr->v4.sin_addr.s_addr = fl->u.ip4.saddr;
558 	}
559 }
560 
561 /* What interface did this skb arrive on? */
sctp_v4_skb_iif(const struct sk_buff * skb)562 static int sctp_v4_skb_iif(const struct sk_buff *skb)
563 {
564 	return inet_iif(skb);
565 }
566 
567 /* Was this packet marked by Explicit Congestion Notification? */
sctp_v4_is_ce(const struct sk_buff * skb)568 static int sctp_v4_is_ce(const struct sk_buff *skb)
569 {
570 	return INET_ECN_is_ce(ip_hdr(skb)->tos);
571 }
572 
573 /* 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)574 static struct sock *sctp_v4_create_accept_sk(struct sock *sk,
575 					     struct sctp_association *asoc,
576 					     bool kern)
577 {
578 	struct sock *newsk = sk_alloc(sock_net(sk), PF_INET, GFP_KERNEL,
579 			sk->sk_prot, kern);
580 	struct inet_sock *newinet;
581 
582 	if (!newsk)
583 		goto out;
584 
585 	sock_init_data(NULL, newsk);
586 
587 	sctp_copy_sock(newsk, sk, asoc);
588 	sock_reset_flag(newsk, SOCK_ZAPPED);
589 
590 	sctp_v4_copy_ip_options(sk, newsk);
591 
592 	newinet = inet_sk(newsk);
593 
594 	newinet->inet_daddr = asoc->peer.primary_addr.v4.sin_addr.s_addr;
595 
596 	sk_refcnt_debug_inc(newsk);
597 
598 	if (newsk->sk_prot->init(newsk)) {
599 		sk_common_release(newsk);
600 		newsk = NULL;
601 	}
602 
603 out:
604 	return newsk;
605 }
606 
sctp_v4_addr_to_user(struct sctp_sock * sp,union sctp_addr * addr)607 static int sctp_v4_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
608 {
609 	/* No address mapping for V4 sockets */
610 	memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
611 	return sizeof(struct sockaddr_in);
612 }
613 
614 /* Dump the v4 addr to the seq file. */
sctp_v4_seq_dump_addr(struct seq_file * seq,union sctp_addr * addr)615 static void sctp_v4_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
616 {
617 	seq_printf(seq, "%pI4 ", &addr->v4.sin_addr);
618 }
619 
sctp_v4_ecn_capable(struct sock * sk)620 static void sctp_v4_ecn_capable(struct sock *sk)
621 {
622 	INET_ECN_xmit(sk);
623 }
624 
sctp_addr_wq_timeout_handler(struct timer_list * t)625 static void sctp_addr_wq_timeout_handler(struct timer_list *t)
626 {
627 	struct net *net = from_timer(net, t, sctp.addr_wq_timer);
628 	struct sctp_sockaddr_entry *addrw, *temp;
629 	struct sctp_sock *sp;
630 
631 	spin_lock_bh(&net->sctp.addr_wq_lock);
632 
633 	list_for_each_entry_safe(addrw, temp, &net->sctp.addr_waitq, list) {
634 		pr_debug("%s: the first ent in wq:%p is addr:%pISc for cmd:%d at "
635 			 "entry:%p\n", __func__, &net->sctp.addr_waitq, &addrw->a.sa,
636 			 addrw->state, addrw);
637 
638 #if IS_ENABLED(CONFIG_IPV6)
639 		/* Now we send an ASCONF for each association */
640 		/* Note. we currently don't handle link local IPv6 addressees */
641 		if (addrw->a.sa.sa_family == AF_INET6) {
642 			struct in6_addr *in6;
643 
644 			if (ipv6_addr_type(&addrw->a.v6.sin6_addr) &
645 			    IPV6_ADDR_LINKLOCAL)
646 				goto free_next;
647 
648 			in6 = (struct in6_addr *)&addrw->a.v6.sin6_addr;
649 			if (ipv6_chk_addr(net, in6, NULL, 0) == 0 &&
650 			    addrw->state == SCTP_ADDR_NEW) {
651 				unsigned long timeo_val;
652 
653 				pr_debug("%s: this is on DAD, trying %d sec "
654 					 "later\n", __func__,
655 					 SCTP_ADDRESS_TICK_DELAY);
656 
657 				timeo_val = jiffies;
658 				timeo_val += msecs_to_jiffies(SCTP_ADDRESS_TICK_DELAY);
659 				mod_timer(&net->sctp.addr_wq_timer, timeo_val);
660 				break;
661 			}
662 		}
663 #endif
664 		list_for_each_entry(sp, &net->sctp.auto_asconf_splist, auto_asconf_list) {
665 			struct sock *sk;
666 
667 			sk = sctp_opt2sk(sp);
668 			/* ignore bound-specific endpoints */
669 			if (!sctp_is_ep_boundall(sk))
670 				continue;
671 			bh_lock_sock(sk);
672 			if (sctp_asconf_mgmt(sp, addrw) < 0)
673 				pr_debug("%s: sctp_asconf_mgmt failed\n", __func__);
674 			bh_unlock_sock(sk);
675 		}
676 #if IS_ENABLED(CONFIG_IPV6)
677 free_next:
678 #endif
679 		list_del(&addrw->list);
680 		kfree(addrw);
681 	}
682 	spin_unlock_bh(&net->sctp.addr_wq_lock);
683 }
684 
sctp_free_addr_wq(struct net * net)685 static void sctp_free_addr_wq(struct net *net)
686 {
687 	struct sctp_sockaddr_entry *addrw;
688 	struct sctp_sockaddr_entry *temp;
689 
690 	spin_lock_bh(&net->sctp.addr_wq_lock);
691 	del_timer(&net->sctp.addr_wq_timer);
692 	list_for_each_entry_safe(addrw, temp, &net->sctp.addr_waitq, list) {
693 		list_del(&addrw->list);
694 		kfree(addrw);
695 	}
696 	spin_unlock_bh(&net->sctp.addr_wq_lock);
697 }
698 
699 /* lookup the entry for the same address in the addr_waitq
700  * sctp_addr_wq MUST be locked
701  */
sctp_addr_wq_lookup(struct net * net,struct sctp_sockaddr_entry * addr)702 static struct sctp_sockaddr_entry *sctp_addr_wq_lookup(struct net *net,
703 					struct sctp_sockaddr_entry *addr)
704 {
705 	struct sctp_sockaddr_entry *addrw;
706 
707 	list_for_each_entry(addrw, &net->sctp.addr_waitq, list) {
708 		if (addrw->a.sa.sa_family != addr->a.sa.sa_family)
709 			continue;
710 		if (addrw->a.sa.sa_family == AF_INET) {
711 			if (addrw->a.v4.sin_addr.s_addr ==
712 			    addr->a.v4.sin_addr.s_addr)
713 				return addrw;
714 		} else if (addrw->a.sa.sa_family == AF_INET6) {
715 			if (ipv6_addr_equal(&addrw->a.v6.sin6_addr,
716 			    &addr->a.v6.sin6_addr))
717 				return addrw;
718 		}
719 	}
720 	return NULL;
721 }
722 
sctp_addr_wq_mgmt(struct net * net,struct sctp_sockaddr_entry * addr,int cmd)723 void sctp_addr_wq_mgmt(struct net *net, struct sctp_sockaddr_entry *addr, int cmd)
724 {
725 	struct sctp_sockaddr_entry *addrw;
726 	unsigned long timeo_val;
727 
728 	/* first, we check if an opposite message already exist in the queue.
729 	 * If we found such message, it is removed.
730 	 * This operation is a bit stupid, but the DHCP client attaches the
731 	 * new address after a couple of addition and deletion of that address
732 	 */
733 
734 	spin_lock_bh(&net->sctp.addr_wq_lock);
735 	/* Offsets existing events in addr_wq */
736 	addrw = sctp_addr_wq_lookup(net, addr);
737 	if (addrw) {
738 		if (addrw->state != cmd) {
739 			pr_debug("%s: offsets existing entry for %d, addr:%pISc "
740 				 "in wq:%p\n", __func__, addrw->state, &addrw->a.sa,
741 				 &net->sctp.addr_waitq);
742 
743 			list_del(&addrw->list);
744 			kfree(addrw);
745 		}
746 		spin_unlock_bh(&net->sctp.addr_wq_lock);
747 		return;
748 	}
749 
750 	/* OK, we have to add the new address to the wait queue */
751 	addrw = kmemdup(addr, sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
752 	if (addrw == NULL) {
753 		spin_unlock_bh(&net->sctp.addr_wq_lock);
754 		return;
755 	}
756 	addrw->state = cmd;
757 	list_add_tail(&addrw->list, &net->sctp.addr_waitq);
758 
759 	pr_debug("%s: add new entry for cmd:%d, addr:%pISc in wq:%p\n",
760 		 __func__, addrw->state, &addrw->a.sa, &net->sctp.addr_waitq);
761 
762 	if (!timer_pending(&net->sctp.addr_wq_timer)) {
763 		timeo_val = jiffies;
764 		timeo_val += msecs_to_jiffies(SCTP_ADDRESS_TICK_DELAY);
765 		mod_timer(&net->sctp.addr_wq_timer, timeo_val);
766 	}
767 	spin_unlock_bh(&net->sctp.addr_wq_lock);
768 }
769 
770 /* Event handler for inet address addition/deletion events.
771  * The sctp_local_addr_list needs to be protocted by a spin lock since
772  * multiple notifiers (say IPv4 and IPv6) may be running at the same
773  * time and thus corrupt the list.
774  * The reader side is protected with RCU.
775  */
sctp_inetaddr_event(struct notifier_block * this,unsigned long ev,void * ptr)776 static int sctp_inetaddr_event(struct notifier_block *this, unsigned long ev,
777 			       void *ptr)
778 {
779 	struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
780 	struct sctp_sockaddr_entry *addr = NULL;
781 	struct sctp_sockaddr_entry *temp;
782 	struct net *net = dev_net(ifa->ifa_dev->dev);
783 	int found = 0;
784 
785 	switch (ev) {
786 	case NETDEV_UP:
787 		addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
788 		if (addr) {
789 			addr->a.v4.sin_family = AF_INET;
790 			addr->a.v4.sin_addr.s_addr = ifa->ifa_local;
791 			addr->valid = 1;
792 			spin_lock_bh(&net->sctp.local_addr_lock);
793 			list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
794 			sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
795 			spin_unlock_bh(&net->sctp.local_addr_lock);
796 		}
797 		break;
798 	case NETDEV_DOWN:
799 		spin_lock_bh(&net->sctp.local_addr_lock);
800 		list_for_each_entry_safe(addr, temp,
801 					&net->sctp.local_addr_list, list) {
802 			if (addr->a.sa.sa_family == AF_INET &&
803 					addr->a.v4.sin_addr.s_addr ==
804 					ifa->ifa_local) {
805 				sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
806 				found = 1;
807 				addr->valid = 0;
808 				list_del_rcu(&addr->list);
809 				break;
810 			}
811 		}
812 		spin_unlock_bh(&net->sctp.local_addr_lock);
813 		if (found)
814 			kfree_rcu(addr, rcu);
815 		break;
816 	}
817 
818 	return NOTIFY_DONE;
819 }
820 
821 /*
822  * Initialize the control inode/socket with a control endpoint data
823  * structure.  This endpoint is reserved exclusively for the OOTB processing.
824  */
sctp_ctl_sock_init(struct net * net)825 static int sctp_ctl_sock_init(struct net *net)
826 {
827 	int err;
828 	sa_family_t family = PF_INET;
829 
830 	if (sctp_get_pf_specific(PF_INET6))
831 		family = PF_INET6;
832 
833 	err = inet_ctl_sock_create(&net->sctp.ctl_sock, family,
834 				   SOCK_SEQPACKET, IPPROTO_SCTP, net);
835 
836 	/* If IPv6 socket could not be created, try the IPv4 socket */
837 	if (err < 0 && family == PF_INET6)
838 		err = inet_ctl_sock_create(&net->sctp.ctl_sock, AF_INET,
839 					   SOCK_SEQPACKET, IPPROTO_SCTP,
840 					   net);
841 
842 	if (err < 0) {
843 		pr_err("Failed to create the SCTP control socket\n");
844 		return err;
845 	}
846 	return 0;
847 }
848 
849 /* Register address family specific functions. */
sctp_register_af(struct sctp_af * af)850 int sctp_register_af(struct sctp_af *af)
851 {
852 	switch (af->sa_family) {
853 	case AF_INET:
854 		if (sctp_af_v4_specific)
855 			return 0;
856 		sctp_af_v4_specific = af;
857 		break;
858 	case AF_INET6:
859 		if (sctp_af_v6_specific)
860 			return 0;
861 		sctp_af_v6_specific = af;
862 		break;
863 	default:
864 		return 0;
865 	}
866 
867 	INIT_LIST_HEAD(&af->list);
868 	list_add_tail(&af->list, &sctp_address_families);
869 	return 1;
870 }
871 
872 /* Get the table of functions for manipulating a particular address
873  * family.
874  */
sctp_get_af_specific(sa_family_t family)875 struct sctp_af *sctp_get_af_specific(sa_family_t family)
876 {
877 	switch (family) {
878 	case AF_INET:
879 		return sctp_af_v4_specific;
880 	case AF_INET6:
881 		return sctp_af_v6_specific;
882 	default:
883 		return NULL;
884 	}
885 }
886 
887 /* Common code to initialize a AF_INET msg_name. */
sctp_inet_msgname(char * msgname,int * addr_len)888 static void sctp_inet_msgname(char *msgname, int *addr_len)
889 {
890 	struct sockaddr_in *sin;
891 
892 	sin = (struct sockaddr_in *)msgname;
893 	*addr_len = sizeof(struct sockaddr_in);
894 	sin->sin_family = AF_INET;
895 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
896 }
897 
898 /* 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)899 static void sctp_inet_event_msgname(struct sctp_ulpevent *event, char *msgname,
900 				    int *addr_len)
901 {
902 	struct sockaddr_in *sin, *sinfrom;
903 
904 	if (msgname) {
905 		struct sctp_association *asoc;
906 
907 		asoc = event->asoc;
908 		sctp_inet_msgname(msgname, addr_len);
909 		sin = (struct sockaddr_in *)msgname;
910 		sinfrom = &asoc->peer.primary_addr.v4;
911 		sin->sin_port = htons(asoc->peer.port);
912 		sin->sin_addr.s_addr = sinfrom->sin_addr.s_addr;
913 	}
914 }
915 
916 /* Initialize and copy out a msgname from an inbound skb. */
sctp_inet_skb_msgname(struct sk_buff * skb,char * msgname,int * len)917 static void sctp_inet_skb_msgname(struct sk_buff *skb, char *msgname, int *len)
918 {
919 	if (msgname) {
920 		struct sctphdr *sh = sctp_hdr(skb);
921 		struct sockaddr_in *sin = (struct sockaddr_in *)msgname;
922 
923 		sctp_inet_msgname(msgname, len);
924 		sin->sin_port = sh->source;
925 		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
926 	}
927 }
928 
929 /* Do we support this AF? */
sctp_inet_af_supported(sa_family_t family,struct sctp_sock * sp)930 static int sctp_inet_af_supported(sa_family_t family, struct sctp_sock *sp)
931 {
932 	/* PF_INET only supports AF_INET addresses. */
933 	return AF_INET == family;
934 }
935 
936 /* Address matching with wildcards allowed. */
sctp_inet_cmp_addr(const union sctp_addr * addr1,const union sctp_addr * addr2,struct sctp_sock * opt)937 static int sctp_inet_cmp_addr(const union sctp_addr *addr1,
938 			      const union sctp_addr *addr2,
939 			      struct sctp_sock *opt)
940 {
941 	/* PF_INET only supports AF_INET addresses. */
942 	if (addr1->sa.sa_family != addr2->sa.sa_family)
943 		return 0;
944 	if (htonl(INADDR_ANY) == addr1->v4.sin_addr.s_addr ||
945 	    htonl(INADDR_ANY) == addr2->v4.sin_addr.s_addr)
946 		return 1;
947 	if (addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr)
948 		return 1;
949 
950 	return 0;
951 }
952 
953 /* Verify that provided sockaddr looks bindable.  Common verification has
954  * already been taken care of.
955  */
sctp_inet_bind_verify(struct sctp_sock * opt,union sctp_addr * addr)956 static int sctp_inet_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
957 {
958 	return sctp_v4_available(addr, opt);
959 }
960 
961 /* Verify that sockaddr looks sendable.  Common verification has already
962  * been taken care of.
963  */
sctp_inet_send_verify(struct sctp_sock * opt,union sctp_addr * addr)964 static int sctp_inet_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
965 {
966 	return 1;
967 }
968 
969 /* Fill in Supported Address Type information for INIT and INIT-ACK
970  * chunks.  Returns number of addresses supported.
971  */
sctp_inet_supported_addrs(const struct sctp_sock * opt,__be16 * types)972 static int sctp_inet_supported_addrs(const struct sctp_sock *opt,
973 				     __be16 *types)
974 {
975 	types[0] = SCTP_PARAM_IPV4_ADDRESS;
976 	return 1;
977 }
978 
979 /* Wrapper routine that calls the ip transmit routine. */
sctp_v4_xmit(struct sk_buff * skb,struct sctp_transport * transport)980 static inline int sctp_v4_xmit(struct sk_buff *skb,
981 			       struct sctp_transport *transport)
982 {
983 	struct inet_sock *inet = inet_sk(skb->sk);
984 	__u8 dscp = inet->tos;
985 
986 	pr_debug("%s: skb:%p, len:%d, src:%pI4, dst:%pI4\n", __func__, skb,
987 		 skb->len, &transport->fl.u.ip4.saddr,
988 		 &transport->fl.u.ip4.daddr);
989 
990 	if (transport->dscp & SCTP_DSCP_SET_MASK)
991 		dscp = transport->dscp & SCTP_DSCP_VAL_MASK;
992 
993 	inet->pmtudisc = transport->param_flags & SPP_PMTUD_ENABLE ?
994 			 IP_PMTUDISC_DO : IP_PMTUDISC_DONT;
995 
996 	SCTP_INC_STATS(sock_net(&inet->sk), SCTP_MIB_OUTSCTPPACKS);
997 
998 	return __ip_queue_xmit(&inet->sk, skb, &transport->fl, dscp);
999 }
1000 
1001 static struct sctp_af sctp_af_inet;
1002 
1003 static struct sctp_pf sctp_pf_inet = {
1004 	.event_msgname = sctp_inet_event_msgname,
1005 	.skb_msgname   = sctp_inet_skb_msgname,
1006 	.af_supported  = sctp_inet_af_supported,
1007 	.cmp_addr      = sctp_inet_cmp_addr,
1008 	.bind_verify   = sctp_inet_bind_verify,
1009 	.send_verify   = sctp_inet_send_verify,
1010 	.supported_addrs = sctp_inet_supported_addrs,
1011 	.create_accept_sk = sctp_v4_create_accept_sk,
1012 	.addr_to_user  = sctp_v4_addr_to_user,
1013 	.to_sk_saddr   = sctp_v4_to_sk_saddr,
1014 	.to_sk_daddr   = sctp_v4_to_sk_daddr,
1015 	.copy_ip_options = sctp_v4_copy_ip_options,
1016 	.af            = &sctp_af_inet
1017 };
1018 
1019 /* Notifier for inetaddr addition/deletion events.  */
1020 static struct notifier_block sctp_inetaddr_notifier = {
1021 	.notifier_call = sctp_inetaddr_event,
1022 };
1023 
1024 /* Socket operations.  */
1025 static const struct proto_ops inet_seqpacket_ops = {
1026 	.family		   = PF_INET,
1027 	.owner		   = THIS_MODULE,
1028 	.release	   = inet_release,	/* Needs to be wrapped... */
1029 	.bind		   = inet_bind,
1030 	.connect	   = sctp_inet_connect,
1031 	.socketpair	   = sock_no_socketpair,
1032 	.accept		   = inet_accept,
1033 	.getname	   = inet_getname,	/* Semantics are different.  */
1034 	.poll		   = sctp_poll,
1035 	.ioctl		   = inet_ioctl,
1036 	.gettstamp	   = sock_gettstamp,
1037 	.listen		   = sctp_inet_listen,
1038 	.shutdown	   = inet_shutdown,	/* Looks harmless.  */
1039 	.setsockopt	   = sock_common_setsockopt, /* IP_SOL IP_OPTION is a problem */
1040 	.getsockopt	   = sock_common_getsockopt,
1041 	.sendmsg	   = inet_sendmsg,
1042 	.recvmsg	   = inet_recvmsg,
1043 	.mmap		   = sock_no_mmap,
1044 	.sendpage	   = sock_no_sendpage,
1045 };
1046 
1047 /* Registration with AF_INET family.  */
1048 static struct inet_protosw sctp_seqpacket_protosw = {
1049 	.type       = SOCK_SEQPACKET,
1050 	.protocol   = IPPROTO_SCTP,
1051 	.prot       = &sctp_prot,
1052 	.ops        = &inet_seqpacket_ops,
1053 	.flags      = SCTP_PROTOSW_FLAG
1054 };
1055 static struct inet_protosw sctp_stream_protosw = {
1056 	.type       = SOCK_STREAM,
1057 	.protocol   = IPPROTO_SCTP,
1058 	.prot       = &sctp_prot,
1059 	.ops        = &inet_seqpacket_ops,
1060 	.flags      = SCTP_PROTOSW_FLAG
1061 };
1062 
1063 /* Register with IP layer.  */
1064 static const struct net_protocol sctp_protocol = {
1065 	.handler     = sctp_rcv,
1066 	.err_handler = sctp_v4_err,
1067 	.no_policy   = 1,
1068 	.netns_ok    = 1,
1069 	.icmp_strict_tag_validation = 1,
1070 };
1071 
1072 /* IPv4 address related functions.  */
1073 static struct sctp_af sctp_af_inet = {
1074 	.sa_family	   = AF_INET,
1075 	.sctp_xmit	   = sctp_v4_xmit,
1076 	.setsockopt	   = ip_setsockopt,
1077 	.getsockopt	   = ip_getsockopt,
1078 	.get_dst	   = sctp_v4_get_dst,
1079 	.get_saddr	   = sctp_v4_get_saddr,
1080 	.copy_addrlist	   = sctp_v4_copy_addrlist,
1081 	.from_skb	   = sctp_v4_from_skb,
1082 	.from_sk	   = sctp_v4_from_sk,
1083 	.from_addr_param   = sctp_v4_from_addr_param,
1084 	.to_addr_param	   = sctp_v4_to_addr_param,
1085 	.cmp_addr	   = sctp_v4_cmp_addr,
1086 	.addr_valid	   = sctp_v4_addr_valid,
1087 	.inaddr_any	   = sctp_v4_inaddr_any,
1088 	.is_any		   = sctp_v4_is_any,
1089 	.available	   = sctp_v4_available,
1090 	.scope		   = sctp_v4_scope,
1091 	.skb_iif	   = sctp_v4_skb_iif,
1092 	.is_ce		   = sctp_v4_is_ce,
1093 	.seq_dump_addr	   = sctp_v4_seq_dump_addr,
1094 	.ecn_capable	   = sctp_v4_ecn_capable,
1095 	.net_header_len	   = sizeof(struct iphdr),
1096 	.sockaddr_len	   = sizeof(struct sockaddr_in),
1097 	.ip_options_len	   = sctp_v4_ip_options_len,
1098 };
1099 
sctp_get_pf_specific(sa_family_t family)1100 struct sctp_pf *sctp_get_pf_specific(sa_family_t family)
1101 {
1102 	switch (family) {
1103 	case PF_INET:
1104 		return sctp_pf_inet_specific;
1105 	case PF_INET6:
1106 		return sctp_pf_inet6_specific;
1107 	default:
1108 		return NULL;
1109 	}
1110 }
1111 
1112 /* Register the PF specific function table.  */
sctp_register_pf(struct sctp_pf * pf,sa_family_t family)1113 int sctp_register_pf(struct sctp_pf *pf, sa_family_t family)
1114 {
1115 	switch (family) {
1116 	case PF_INET:
1117 		if (sctp_pf_inet_specific)
1118 			return 0;
1119 		sctp_pf_inet_specific = pf;
1120 		break;
1121 	case PF_INET6:
1122 		if (sctp_pf_inet6_specific)
1123 			return 0;
1124 		sctp_pf_inet6_specific = pf;
1125 		break;
1126 	default:
1127 		return 0;
1128 	}
1129 	return 1;
1130 }
1131 
init_sctp_mibs(struct net * net)1132 static inline int init_sctp_mibs(struct net *net)
1133 {
1134 	net->sctp.sctp_statistics = alloc_percpu(struct sctp_mib);
1135 	if (!net->sctp.sctp_statistics)
1136 		return -ENOMEM;
1137 	return 0;
1138 }
1139 
cleanup_sctp_mibs(struct net * net)1140 static inline void cleanup_sctp_mibs(struct net *net)
1141 {
1142 	free_percpu(net->sctp.sctp_statistics);
1143 }
1144 
sctp_v4_pf_init(void)1145 static void sctp_v4_pf_init(void)
1146 {
1147 	/* Initialize the SCTP specific PF functions. */
1148 	sctp_register_pf(&sctp_pf_inet, PF_INET);
1149 	sctp_register_af(&sctp_af_inet);
1150 }
1151 
sctp_v4_pf_exit(void)1152 static void sctp_v4_pf_exit(void)
1153 {
1154 	list_del(&sctp_af_inet.list);
1155 }
1156 
sctp_v4_protosw_init(void)1157 static int sctp_v4_protosw_init(void)
1158 {
1159 	int rc;
1160 
1161 	rc = proto_register(&sctp_prot, 1);
1162 	if (rc)
1163 		return rc;
1164 
1165 	/* Register SCTP(UDP and TCP style) with socket layer.  */
1166 	inet_register_protosw(&sctp_seqpacket_protosw);
1167 	inet_register_protosw(&sctp_stream_protosw);
1168 
1169 	return 0;
1170 }
1171 
sctp_v4_protosw_exit(void)1172 static void sctp_v4_protosw_exit(void)
1173 {
1174 	inet_unregister_protosw(&sctp_stream_protosw);
1175 	inet_unregister_protosw(&sctp_seqpacket_protosw);
1176 	proto_unregister(&sctp_prot);
1177 }
1178 
sctp_v4_add_protocol(void)1179 static int sctp_v4_add_protocol(void)
1180 {
1181 	/* Register notifier for inet address additions/deletions. */
1182 	register_inetaddr_notifier(&sctp_inetaddr_notifier);
1183 
1184 	/* Register SCTP with inet layer.  */
1185 	if (inet_add_protocol(&sctp_protocol, IPPROTO_SCTP) < 0)
1186 		return -EAGAIN;
1187 
1188 	return 0;
1189 }
1190 
sctp_v4_del_protocol(void)1191 static void sctp_v4_del_protocol(void)
1192 {
1193 	inet_del_protocol(&sctp_protocol, IPPROTO_SCTP);
1194 	unregister_inetaddr_notifier(&sctp_inetaddr_notifier);
1195 }
1196 
sctp_defaults_init(struct net * net)1197 static int __net_init sctp_defaults_init(struct net *net)
1198 {
1199 	int status;
1200 
1201 	/*
1202 	 * 14. Suggested SCTP Protocol Parameter Values
1203 	 */
1204 	/* The following protocol parameters are RECOMMENDED:  */
1205 	/* RTO.Initial              - 3  seconds */
1206 	net->sctp.rto_initial			= SCTP_RTO_INITIAL;
1207 	/* RTO.Min                  - 1  second */
1208 	net->sctp.rto_min	 		= SCTP_RTO_MIN;
1209 	/* RTO.Max                 -  60 seconds */
1210 	net->sctp.rto_max 			= SCTP_RTO_MAX;
1211 	/* RTO.Alpha                - 1/8 */
1212 	net->sctp.rto_alpha			= SCTP_RTO_ALPHA;
1213 	/* RTO.Beta                 - 1/4 */
1214 	net->sctp.rto_beta			= SCTP_RTO_BETA;
1215 
1216 	/* Valid.Cookie.Life        - 60  seconds */
1217 	net->sctp.valid_cookie_life		= SCTP_DEFAULT_COOKIE_LIFE;
1218 
1219 	/* Whether Cookie Preservative is enabled(1) or not(0) */
1220 	net->sctp.cookie_preserve_enable 	= 1;
1221 
1222 	/* Default sctp sockets to use md5 as their hmac alg */
1223 #if defined (CONFIG_SCTP_DEFAULT_COOKIE_HMAC_MD5)
1224 	net->sctp.sctp_hmac_alg			= "md5";
1225 #elif defined (CONFIG_SCTP_DEFAULT_COOKIE_HMAC_SHA1)
1226 	net->sctp.sctp_hmac_alg			= "sha1";
1227 #else
1228 	net->sctp.sctp_hmac_alg			= NULL;
1229 #endif
1230 
1231 	/* Max.Burst		    - 4 */
1232 	net->sctp.max_burst			= SCTP_DEFAULT_MAX_BURST;
1233 
1234 	/* Disable of Primary Path Switchover by default */
1235 	net->sctp.ps_retrans = SCTP_PS_RETRANS_MAX;
1236 
1237 	/* Enable pf state by default */
1238 	net->sctp.pf_enable = 1;
1239 
1240 	/* Ignore pf exposure feature by default */
1241 	net->sctp.pf_expose = SCTP_PF_EXPOSE_UNSET;
1242 
1243 	/* Association.Max.Retrans  - 10 attempts
1244 	 * Path.Max.Retrans         - 5  attempts (per destination address)
1245 	 * Max.Init.Retransmits     - 8  attempts
1246 	 */
1247 	net->sctp.max_retrans_association	= 10;
1248 	net->sctp.max_retrans_path		= 5;
1249 	net->sctp.max_retrans_init		= 8;
1250 
1251 	/* Sendbuffer growth	    - do per-socket accounting */
1252 	net->sctp.sndbuf_policy			= 0;
1253 
1254 	/* Rcvbuffer growth	    - do per-socket accounting */
1255 	net->sctp.rcvbuf_policy			= 0;
1256 
1257 	/* HB.interval              - 30 seconds */
1258 	net->sctp.hb_interval			= SCTP_DEFAULT_TIMEOUT_HEARTBEAT;
1259 
1260 	/* delayed SACK timeout */
1261 	net->sctp.sack_timeout			= SCTP_DEFAULT_TIMEOUT_SACK;
1262 
1263 	/* Disable ADDIP by default. */
1264 	net->sctp.addip_enable = 0;
1265 	net->sctp.addip_noauth = 0;
1266 	net->sctp.default_auto_asconf = 0;
1267 
1268 	/* Enable PR-SCTP by default. */
1269 	net->sctp.prsctp_enable = 1;
1270 
1271 	/* Disable RECONF by default. */
1272 	net->sctp.reconf_enable = 0;
1273 
1274 	/* Disable AUTH by default. */
1275 	net->sctp.auth_enable = 0;
1276 
1277 	/* Enable ECN by default. */
1278 	net->sctp.ecn_enable = 1;
1279 
1280 	/* Set SCOPE policy to enabled */
1281 	net->sctp.scope_policy = SCTP_SCOPE_POLICY_ENABLE;
1282 
1283 	/* Set the default rwnd update threshold */
1284 	net->sctp.rwnd_upd_shift = SCTP_DEFAULT_RWND_SHIFT;
1285 
1286 	/* Initialize maximum autoclose timeout. */
1287 	net->sctp.max_autoclose		= INT_MAX / HZ;
1288 
1289 	status = sctp_sysctl_net_register(net);
1290 	if (status)
1291 		goto err_sysctl_register;
1292 
1293 	/* Allocate and initialise sctp mibs.  */
1294 	status = init_sctp_mibs(net);
1295 	if (status)
1296 		goto err_init_mibs;
1297 
1298 #ifdef CONFIG_PROC_FS
1299 	/* Initialize proc fs directory.  */
1300 	status = sctp_proc_init(net);
1301 	if (status)
1302 		goto err_init_proc;
1303 #endif
1304 
1305 	sctp_dbg_objcnt_init(net);
1306 
1307 	/* Initialize the local address list. */
1308 	INIT_LIST_HEAD(&net->sctp.local_addr_list);
1309 	spin_lock_init(&net->sctp.local_addr_lock);
1310 	sctp_get_local_addr_list(net);
1311 
1312 	/* Initialize the address event list */
1313 	INIT_LIST_HEAD(&net->sctp.addr_waitq);
1314 	INIT_LIST_HEAD(&net->sctp.auto_asconf_splist);
1315 	spin_lock_init(&net->sctp.addr_wq_lock);
1316 	net->sctp.addr_wq_timer.expires = 0;
1317 	timer_setup(&net->sctp.addr_wq_timer, sctp_addr_wq_timeout_handler, 0);
1318 
1319 	return 0;
1320 
1321 #ifdef CONFIG_PROC_FS
1322 err_init_proc:
1323 	cleanup_sctp_mibs(net);
1324 #endif
1325 err_init_mibs:
1326 	sctp_sysctl_net_unregister(net);
1327 err_sysctl_register:
1328 	return status;
1329 }
1330 
sctp_defaults_exit(struct net * net)1331 static void __net_exit sctp_defaults_exit(struct net *net)
1332 {
1333 	/* Free the local address list */
1334 	sctp_free_addr_wq(net);
1335 	sctp_free_local_addr_list(net);
1336 
1337 #ifdef CONFIG_PROC_FS
1338 	remove_proc_subtree("sctp", net->proc_net);
1339 	net->sctp.proc_net_sctp = NULL;
1340 #endif
1341 	cleanup_sctp_mibs(net);
1342 	sctp_sysctl_net_unregister(net);
1343 }
1344 
1345 static struct pernet_operations sctp_defaults_ops = {
1346 	.init = sctp_defaults_init,
1347 	.exit = sctp_defaults_exit,
1348 };
1349 
sctp_ctrlsock_init(struct net * net)1350 static int __net_init sctp_ctrlsock_init(struct net *net)
1351 {
1352 	int status;
1353 
1354 	/* Initialize the control inode/socket for handling OOTB packets.  */
1355 	status = sctp_ctl_sock_init(net);
1356 	if (status)
1357 		pr_err("Failed to initialize the SCTP control sock\n");
1358 
1359 	return status;
1360 }
1361 
sctp_ctrlsock_exit(struct net * net)1362 static void __net_exit sctp_ctrlsock_exit(struct net *net)
1363 {
1364 	/* Free the control endpoint.  */
1365 	inet_ctl_sock_destroy(net->sctp.ctl_sock);
1366 }
1367 
1368 static struct pernet_operations sctp_ctrlsock_ops = {
1369 	.init = sctp_ctrlsock_init,
1370 	.exit = sctp_ctrlsock_exit,
1371 };
1372 
1373 /* Initialize the universe into something sensible.  */
sctp_init(void)1374 static __init int sctp_init(void)
1375 {
1376 	unsigned long nr_pages = totalram_pages();
1377 	unsigned long limit;
1378 	unsigned long goal;
1379 	int max_entry_order;
1380 	int num_entries;
1381 	int max_share;
1382 	int status;
1383 	int order;
1384 	int i;
1385 
1386 	sock_skb_cb_check_size(sizeof(struct sctp_ulpevent));
1387 
1388 	/* Allocate bind_bucket and chunk caches. */
1389 	status = -ENOBUFS;
1390 	sctp_bucket_cachep = kmem_cache_create("sctp_bind_bucket",
1391 					       sizeof(struct sctp_bind_bucket),
1392 					       0, SLAB_HWCACHE_ALIGN,
1393 					       NULL);
1394 	if (!sctp_bucket_cachep)
1395 		goto out;
1396 
1397 	sctp_chunk_cachep = kmem_cache_create("sctp_chunk",
1398 					       sizeof(struct sctp_chunk),
1399 					       0, SLAB_HWCACHE_ALIGN,
1400 					       NULL);
1401 	if (!sctp_chunk_cachep)
1402 		goto err_chunk_cachep;
1403 
1404 	status = percpu_counter_init(&sctp_sockets_allocated, 0, GFP_KERNEL);
1405 	if (status)
1406 		goto err_percpu_counter_init;
1407 
1408 	/* Implementation specific variables. */
1409 
1410 	/* Initialize default stream count setup information. */
1411 	sctp_max_instreams    		= SCTP_DEFAULT_INSTREAMS;
1412 	sctp_max_outstreams   		= SCTP_DEFAULT_OUTSTREAMS;
1413 
1414 	/* Initialize handle used for association ids. */
1415 	idr_init(&sctp_assocs_id);
1416 
1417 	limit = nr_free_buffer_pages() / 8;
1418 	limit = max(limit, 128UL);
1419 	sysctl_sctp_mem[0] = limit / 4 * 3;
1420 	sysctl_sctp_mem[1] = limit;
1421 	sysctl_sctp_mem[2] = sysctl_sctp_mem[0] * 2;
1422 
1423 	/* Set per-socket limits to no more than 1/128 the pressure threshold*/
1424 	limit = (sysctl_sctp_mem[1]) << (PAGE_SHIFT - 7);
1425 	max_share = min(4UL*1024*1024, limit);
1426 
1427 	sysctl_sctp_rmem[0] = SK_MEM_QUANTUM; /* give each asoc 1 page min */
1428 	sysctl_sctp_rmem[1] = 1500 * SKB_TRUESIZE(1);
1429 	sysctl_sctp_rmem[2] = max(sysctl_sctp_rmem[1], max_share);
1430 
1431 	sysctl_sctp_wmem[0] = SK_MEM_QUANTUM;
1432 	sysctl_sctp_wmem[1] = 16*1024;
1433 	sysctl_sctp_wmem[2] = max(64*1024, max_share);
1434 
1435 	/* Size and allocate the association hash table.
1436 	 * The methodology is similar to that of the tcp hash tables.
1437 	 * Though not identical.  Start by getting a goal size
1438 	 */
1439 	if (nr_pages >= (128 * 1024))
1440 		goal = nr_pages >> (22 - PAGE_SHIFT);
1441 	else
1442 		goal = nr_pages >> (24 - PAGE_SHIFT);
1443 
1444 	/* Then compute the page order for said goal */
1445 	order = get_order(goal);
1446 
1447 	/* Now compute the required page order for the maximum sized table we
1448 	 * want to create
1449 	 */
1450 	max_entry_order = get_order(MAX_SCTP_PORT_HASH_ENTRIES *
1451 				    sizeof(struct sctp_bind_hashbucket));
1452 
1453 	/* Limit the page order by that maximum hash table size */
1454 	order = min(order, max_entry_order);
1455 
1456 	/* Allocate and initialize the endpoint hash table.  */
1457 	sctp_ep_hashsize = 64;
1458 	sctp_ep_hashtable =
1459 		kmalloc_array(64, sizeof(struct sctp_hashbucket), GFP_KERNEL);
1460 	if (!sctp_ep_hashtable) {
1461 		pr_err("Failed endpoint_hash alloc\n");
1462 		status = -ENOMEM;
1463 		goto err_ehash_alloc;
1464 	}
1465 	for (i = 0; i < sctp_ep_hashsize; i++) {
1466 		rwlock_init(&sctp_ep_hashtable[i].lock);
1467 		INIT_HLIST_HEAD(&sctp_ep_hashtable[i].chain);
1468 	}
1469 
1470 	/* Allocate and initialize the SCTP port hash table.
1471 	 * Note that order is initalized to start at the max sized
1472 	 * table we want to support.  If we can't get that many pages
1473 	 * reduce the order and try again
1474 	 */
1475 	do {
1476 		sctp_port_hashtable = (struct sctp_bind_hashbucket *)
1477 			__get_free_pages(GFP_KERNEL | __GFP_NOWARN, order);
1478 	} while (!sctp_port_hashtable && --order > 0);
1479 
1480 	if (!sctp_port_hashtable) {
1481 		pr_err("Failed bind hash alloc\n");
1482 		status = -ENOMEM;
1483 		goto err_bhash_alloc;
1484 	}
1485 
1486 	/* Now compute the number of entries that will fit in the
1487 	 * port hash space we allocated
1488 	 */
1489 	num_entries = (1UL << order) * PAGE_SIZE /
1490 		      sizeof(struct sctp_bind_hashbucket);
1491 
1492 	/* And finish by rounding it down to the nearest power of two.
1493 	 * This wastes some memory of course, but it's needed because
1494 	 * the hash function operates based on the assumption that
1495 	 * the number of entries is a power of two.
1496 	 */
1497 	sctp_port_hashsize = rounddown_pow_of_two(num_entries);
1498 
1499 	for (i = 0; i < sctp_port_hashsize; i++) {
1500 		spin_lock_init(&sctp_port_hashtable[i].lock);
1501 		INIT_HLIST_HEAD(&sctp_port_hashtable[i].chain);
1502 	}
1503 
1504 	status = sctp_transport_hashtable_init();
1505 	if (status)
1506 		goto err_thash_alloc;
1507 
1508 	pr_info("Hash tables configured (bind %d/%d)\n", sctp_port_hashsize,
1509 		num_entries);
1510 
1511 	sctp_sysctl_register();
1512 
1513 	INIT_LIST_HEAD(&sctp_address_families);
1514 	sctp_v4_pf_init();
1515 	sctp_v6_pf_init();
1516 	sctp_sched_ops_init();
1517 
1518 	status = register_pernet_subsys(&sctp_defaults_ops);
1519 	if (status)
1520 		goto err_register_defaults;
1521 
1522 	status = sctp_v4_protosw_init();
1523 	if (status)
1524 		goto err_protosw_init;
1525 
1526 	status = sctp_v6_protosw_init();
1527 	if (status)
1528 		goto err_v6_protosw_init;
1529 
1530 	status = register_pernet_subsys(&sctp_ctrlsock_ops);
1531 	if (status)
1532 		goto err_register_ctrlsock;
1533 
1534 	status = sctp_v4_add_protocol();
1535 	if (status)
1536 		goto err_add_protocol;
1537 
1538 	/* Register SCTP with inet6 layer.  */
1539 	status = sctp_v6_add_protocol();
1540 	if (status)
1541 		goto err_v6_add_protocol;
1542 
1543 	if (sctp_offload_init() < 0)
1544 		pr_crit("%s: Cannot add SCTP protocol offload\n", __func__);
1545 
1546 out:
1547 	return status;
1548 err_v6_add_protocol:
1549 	sctp_v4_del_protocol();
1550 err_add_protocol:
1551 	unregister_pernet_subsys(&sctp_ctrlsock_ops);
1552 err_register_ctrlsock:
1553 	sctp_v6_protosw_exit();
1554 err_v6_protosw_init:
1555 	sctp_v4_protosw_exit();
1556 err_protosw_init:
1557 	unregister_pernet_subsys(&sctp_defaults_ops);
1558 err_register_defaults:
1559 	sctp_v4_pf_exit();
1560 	sctp_v6_pf_exit();
1561 	sctp_sysctl_unregister();
1562 	free_pages((unsigned long)sctp_port_hashtable,
1563 		   get_order(sctp_port_hashsize *
1564 			     sizeof(struct sctp_bind_hashbucket)));
1565 err_bhash_alloc:
1566 	sctp_transport_hashtable_destroy();
1567 err_thash_alloc:
1568 	kfree(sctp_ep_hashtable);
1569 err_ehash_alloc:
1570 	percpu_counter_destroy(&sctp_sockets_allocated);
1571 err_percpu_counter_init:
1572 	kmem_cache_destroy(sctp_chunk_cachep);
1573 err_chunk_cachep:
1574 	kmem_cache_destroy(sctp_bucket_cachep);
1575 	goto out;
1576 }
1577 
1578 /* Exit handler for the SCTP protocol.  */
sctp_exit(void)1579 static __exit void sctp_exit(void)
1580 {
1581 	/* BUG.  This should probably do something useful like clean
1582 	 * up all the remaining associations and all that memory.
1583 	 */
1584 
1585 	/* Unregister with inet6/inet layers. */
1586 	sctp_v6_del_protocol();
1587 	sctp_v4_del_protocol();
1588 
1589 	unregister_pernet_subsys(&sctp_ctrlsock_ops);
1590 
1591 	/* Free protosw registrations */
1592 	sctp_v6_protosw_exit();
1593 	sctp_v4_protosw_exit();
1594 
1595 	unregister_pernet_subsys(&sctp_defaults_ops);
1596 
1597 	/* Unregister with socket layer. */
1598 	sctp_v6_pf_exit();
1599 	sctp_v4_pf_exit();
1600 
1601 	sctp_sysctl_unregister();
1602 
1603 	free_pages((unsigned long)sctp_port_hashtable,
1604 		   get_order(sctp_port_hashsize *
1605 			     sizeof(struct sctp_bind_hashbucket)));
1606 	kfree(sctp_ep_hashtable);
1607 	sctp_transport_hashtable_destroy();
1608 
1609 	percpu_counter_destroy(&sctp_sockets_allocated);
1610 
1611 	rcu_barrier(); /* Wait for completion of call_rcu()'s */
1612 
1613 	kmem_cache_destroy(sctp_chunk_cachep);
1614 	kmem_cache_destroy(sctp_bucket_cachep);
1615 }
1616 
1617 module_init(sctp_init);
1618 module_exit(sctp_exit);
1619 
1620 /*
1621  * __stringify doesn't likes enums, so use IPPROTO_SCTP value (132) directly.
1622  */
1623 MODULE_ALIAS("net-pf-" __stringify(PF_INET) "-proto-132");
1624 MODULE_ALIAS("net-pf-" __stringify(PF_INET6) "-proto-132");
1625 MODULE_AUTHOR("Linux Kernel SCTP developers <linux-sctp@vger.kernel.org>");
1626 MODULE_DESCRIPTION("Support for the SCTP protocol (RFC2960)");
1627 module_param_named(no_checksums, sctp_checksum_disable, bool, 0644);
1628 MODULE_PARM_DESC(no_checksums, "Disable checksums computing and verification");
1629 MODULE_LICENSE("GPL");
1630