xref: /linux/net/sctp/socket.c (revision 092e0e7e520a1fca03e13c9f2d157432a8657ff2)
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) 2001-2003 Intel Corp.
6  * Copyright (c) 2001-2002 Nokia, Inc.
7  * Copyright (c) 2001 La Monte H.P. Yarroll
8  *
9  * This file is part of the SCTP kernel implementation
10  *
11  * These functions interface with the sockets layer to implement the
12  * SCTP Extensions for the Sockets API.
13  *
14  * Note that the descriptions from the specification are USER level
15  * functions--this file is the functions which populate the struct proto
16  * for SCTP which is the BOTTOM of the sockets interface.
17  *
18  * This SCTP implementation is free software;
19  * you can redistribute it and/or modify it under the terms of
20  * the GNU General Public License as published by
21  * the Free Software Foundation; either version 2, or (at your option)
22  * any later version.
23  *
24  * This SCTP implementation is distributed in the hope that it
25  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
26  *                 ************************
27  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
28  * See the GNU General Public License for more details.
29  *
30  * You should have received a copy of the GNU General Public License
31  * along with GNU CC; see the file COPYING.  If not, write to
32  * the Free Software Foundation, 59 Temple Place - Suite 330,
33  * Boston, MA 02111-1307, USA.
34  *
35  * Please send any bug reports or fixes you make to the
36  * email address(es):
37  *    lksctp developers <lksctp-developers@lists.sourceforge.net>
38  *
39  * Or submit a bug report through the following website:
40  *    http://www.sf.net/projects/lksctp
41  *
42  * Written or modified by:
43  *    La Monte H.P. Yarroll <piggy@acm.org>
44  *    Narasimha Budihal     <narsi@refcode.org>
45  *    Karl Knutson          <karl@athena.chicago.il.us>
46  *    Jon Grimm             <jgrimm@us.ibm.com>
47  *    Xingang Guo           <xingang.guo@intel.com>
48  *    Daisy Chang           <daisyc@us.ibm.com>
49  *    Sridhar Samudrala     <samudrala@us.ibm.com>
50  *    Inaky Perez-Gonzalez  <inaky.gonzalez@intel.com>
51  *    Ardelle Fan	    <ardelle.fan@intel.com>
52  *    Ryan Layer	    <rmlayer@us.ibm.com>
53  *    Anup Pemmaiah         <pemmaiah@cc.usu.edu>
54  *    Kevin Gao             <kevin.gao@intel.com>
55  *
56  * Any bugs reported given to us we will try to fix... any fixes shared will
57  * be incorporated into the next SCTP release.
58  */
59 
60 #include <linux/types.h>
61 #include <linux/kernel.h>
62 #include <linux/wait.h>
63 #include <linux/time.h>
64 #include <linux/ip.h>
65 #include <linux/capability.h>
66 #include <linux/fcntl.h>
67 #include <linux/poll.h>
68 #include <linux/init.h>
69 #include <linux/crypto.h>
70 #include <linux/slab.h>
71 
72 #include <net/ip.h>
73 #include <net/icmp.h>
74 #include <net/route.h>
75 #include <net/ipv6.h>
76 #include <net/inet_common.h>
77 
78 #include <linux/socket.h> /* for sa_family_t */
79 #include <net/sock.h>
80 #include <net/sctp/sctp.h>
81 #include <net/sctp/sm.h>
82 
83 /* WARNING:  Please do not remove the SCTP_STATIC attribute to
84  * any of the functions below as they are used to export functions
85  * used by a project regression testsuite.
86  */
87 
88 /* Forward declarations for internal helper functions. */
89 static int sctp_writeable(struct sock *sk);
90 static void sctp_wfree(struct sk_buff *skb);
91 static int sctp_wait_for_sndbuf(struct sctp_association *, long *timeo_p,
92 				size_t msg_len);
93 static int sctp_wait_for_packet(struct sock * sk, int *err, long *timeo_p);
94 static int sctp_wait_for_connect(struct sctp_association *, long *timeo_p);
95 static int sctp_wait_for_accept(struct sock *sk, long timeo);
96 static void sctp_wait_for_close(struct sock *sk, long timeo);
97 static struct sctp_af *sctp_sockaddr_af(struct sctp_sock *opt,
98 					union sctp_addr *addr, int len);
99 static int sctp_bindx_add(struct sock *, struct sockaddr *, int);
100 static int sctp_bindx_rem(struct sock *, struct sockaddr *, int);
101 static int sctp_send_asconf_add_ip(struct sock *, struct sockaddr *, int);
102 static int sctp_send_asconf_del_ip(struct sock *, struct sockaddr *, int);
103 static int sctp_send_asconf(struct sctp_association *asoc,
104 			    struct sctp_chunk *chunk);
105 static int sctp_do_bind(struct sock *, union sctp_addr *, int);
106 static int sctp_autobind(struct sock *sk);
107 static void sctp_sock_migrate(struct sock *, struct sock *,
108 			      struct sctp_association *, sctp_socket_type_t);
109 static char *sctp_hmac_alg = SCTP_COOKIE_HMAC_ALG;
110 
111 extern struct kmem_cache *sctp_bucket_cachep;
112 extern int sysctl_sctp_mem[3];
113 extern int sysctl_sctp_rmem[3];
114 extern int sysctl_sctp_wmem[3];
115 
116 static int sctp_memory_pressure;
117 static atomic_t sctp_memory_allocated;
118 struct percpu_counter sctp_sockets_allocated;
119 
120 static void sctp_enter_memory_pressure(struct sock *sk)
121 {
122 	sctp_memory_pressure = 1;
123 }
124 
125 
126 /* Get the sndbuf space available at the time on the association.  */
127 static inline int sctp_wspace(struct sctp_association *asoc)
128 {
129 	int amt;
130 
131 	if (asoc->ep->sndbuf_policy)
132 		amt = asoc->sndbuf_used;
133 	else
134 		amt = sk_wmem_alloc_get(asoc->base.sk);
135 
136 	if (amt >= asoc->base.sk->sk_sndbuf) {
137 		if (asoc->base.sk->sk_userlocks & SOCK_SNDBUF_LOCK)
138 			amt = 0;
139 		else {
140 			amt = sk_stream_wspace(asoc->base.sk);
141 			if (amt < 0)
142 				amt = 0;
143 		}
144 	} else {
145 		amt = asoc->base.sk->sk_sndbuf - amt;
146 	}
147 	return amt;
148 }
149 
150 /* Increment the used sndbuf space count of the corresponding association by
151  * the size of the outgoing data chunk.
152  * Also, set the skb destructor for sndbuf accounting later.
153  *
154  * Since it is always 1-1 between chunk and skb, and also a new skb is always
155  * allocated for chunk bundling in sctp_packet_transmit(), we can use the
156  * destructor in the data chunk skb for the purpose of the sndbuf space
157  * tracking.
158  */
159 static inline void sctp_set_owner_w(struct sctp_chunk *chunk)
160 {
161 	struct sctp_association *asoc = chunk->asoc;
162 	struct sock *sk = asoc->base.sk;
163 
164 	/* The sndbuf space is tracked per association.  */
165 	sctp_association_hold(asoc);
166 
167 	skb_set_owner_w(chunk->skb, sk);
168 
169 	chunk->skb->destructor = sctp_wfree;
170 	/* Save the chunk pointer in skb for sctp_wfree to use later.  */
171 	*((struct sctp_chunk **)(chunk->skb->cb)) = chunk;
172 
173 	asoc->sndbuf_used += SCTP_DATA_SNDSIZE(chunk) +
174 				sizeof(struct sk_buff) +
175 				sizeof(struct sctp_chunk);
176 
177 	atomic_add(sizeof(struct sctp_chunk), &sk->sk_wmem_alloc);
178 	sk->sk_wmem_queued += chunk->skb->truesize;
179 	sk_mem_charge(sk, chunk->skb->truesize);
180 }
181 
182 /* Verify that this is a valid address. */
183 static inline int sctp_verify_addr(struct sock *sk, union sctp_addr *addr,
184 				   int len)
185 {
186 	struct sctp_af *af;
187 
188 	/* Verify basic sockaddr. */
189 	af = sctp_sockaddr_af(sctp_sk(sk), addr, len);
190 	if (!af)
191 		return -EINVAL;
192 
193 	/* Is this a valid SCTP address?  */
194 	if (!af->addr_valid(addr, sctp_sk(sk), NULL))
195 		return -EINVAL;
196 
197 	if (!sctp_sk(sk)->pf->send_verify(sctp_sk(sk), (addr)))
198 		return -EINVAL;
199 
200 	return 0;
201 }
202 
203 /* Look up the association by its id.  If this is not a UDP-style
204  * socket, the ID field is always ignored.
205  */
206 struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id)
207 {
208 	struct sctp_association *asoc = NULL;
209 
210 	/* If this is not a UDP-style socket, assoc id should be ignored. */
211 	if (!sctp_style(sk, UDP)) {
212 		/* Return NULL if the socket state is not ESTABLISHED. It
213 		 * could be a TCP-style listening socket or a socket which
214 		 * hasn't yet called connect() to establish an association.
215 		 */
216 		if (!sctp_sstate(sk, ESTABLISHED))
217 			return NULL;
218 
219 		/* Get the first and the only association from the list. */
220 		if (!list_empty(&sctp_sk(sk)->ep->asocs))
221 			asoc = list_entry(sctp_sk(sk)->ep->asocs.next,
222 					  struct sctp_association, asocs);
223 		return asoc;
224 	}
225 
226 	/* Otherwise this is a UDP-style socket. */
227 	if (!id || (id == (sctp_assoc_t)-1))
228 		return NULL;
229 
230 	spin_lock_bh(&sctp_assocs_id_lock);
231 	asoc = (struct sctp_association *)idr_find(&sctp_assocs_id, (int)id);
232 	spin_unlock_bh(&sctp_assocs_id_lock);
233 
234 	if (!asoc || (asoc->base.sk != sk) || asoc->base.dead)
235 		return NULL;
236 
237 	return asoc;
238 }
239 
240 /* Look up the transport from an address and an assoc id. If both address and
241  * id are specified, the associations matching the address and the id should be
242  * the same.
243  */
244 static struct sctp_transport *sctp_addr_id2transport(struct sock *sk,
245 					      struct sockaddr_storage *addr,
246 					      sctp_assoc_t id)
247 {
248 	struct sctp_association *addr_asoc = NULL, *id_asoc = NULL;
249 	struct sctp_transport *transport;
250 	union sctp_addr *laddr = (union sctp_addr *)addr;
251 
252 	addr_asoc = sctp_endpoint_lookup_assoc(sctp_sk(sk)->ep,
253 					       laddr,
254 					       &transport);
255 
256 	if (!addr_asoc)
257 		return NULL;
258 
259 	id_asoc = sctp_id2assoc(sk, id);
260 	if (id_asoc && (id_asoc != addr_asoc))
261 		return NULL;
262 
263 	sctp_get_pf_specific(sk->sk_family)->addr_v4map(sctp_sk(sk),
264 						(union sctp_addr *)addr);
265 
266 	return transport;
267 }
268 
269 /* API 3.1.2 bind() - UDP Style Syntax
270  * The syntax of bind() is,
271  *
272  *   ret = bind(int sd, struct sockaddr *addr, int addrlen);
273  *
274  *   sd      - the socket descriptor returned by socket().
275  *   addr    - the address structure (struct sockaddr_in or struct
276  *             sockaddr_in6 [RFC 2553]),
277  *   addr_len - the size of the address structure.
278  */
279 SCTP_STATIC int sctp_bind(struct sock *sk, struct sockaddr *addr, int addr_len)
280 {
281 	int retval = 0;
282 
283 	sctp_lock_sock(sk);
284 
285 	SCTP_DEBUG_PRINTK("sctp_bind(sk: %p, addr: %p, addr_len: %d)\n",
286 			  sk, addr, addr_len);
287 
288 	/* Disallow binding twice. */
289 	if (!sctp_sk(sk)->ep->base.bind_addr.port)
290 		retval = sctp_do_bind(sk, (union sctp_addr *)addr,
291 				      addr_len);
292 	else
293 		retval = -EINVAL;
294 
295 	sctp_release_sock(sk);
296 
297 	return retval;
298 }
299 
300 static long sctp_get_port_local(struct sock *, union sctp_addr *);
301 
302 /* Verify this is a valid sockaddr. */
303 static struct sctp_af *sctp_sockaddr_af(struct sctp_sock *opt,
304 					union sctp_addr *addr, int len)
305 {
306 	struct sctp_af *af;
307 
308 	/* Check minimum size.  */
309 	if (len < sizeof (struct sockaddr))
310 		return NULL;
311 
312 	/* V4 mapped address are really of AF_INET family */
313 	if (addr->sa.sa_family == AF_INET6 &&
314 	    ipv6_addr_v4mapped(&addr->v6.sin6_addr)) {
315 		if (!opt->pf->af_supported(AF_INET, opt))
316 			return NULL;
317 	} else {
318 		/* Does this PF support this AF? */
319 		if (!opt->pf->af_supported(addr->sa.sa_family, opt))
320 			return NULL;
321 	}
322 
323 	/* If we get this far, af is valid. */
324 	af = sctp_get_af_specific(addr->sa.sa_family);
325 
326 	if (len < af->sockaddr_len)
327 		return NULL;
328 
329 	return af;
330 }
331 
332 /* Bind a local address either to an endpoint or to an association.  */
333 SCTP_STATIC int sctp_do_bind(struct sock *sk, union sctp_addr *addr, int len)
334 {
335 	struct sctp_sock *sp = sctp_sk(sk);
336 	struct sctp_endpoint *ep = sp->ep;
337 	struct sctp_bind_addr *bp = &ep->base.bind_addr;
338 	struct sctp_af *af;
339 	unsigned short snum;
340 	int ret = 0;
341 
342 	/* Common sockaddr verification. */
343 	af = sctp_sockaddr_af(sp, addr, len);
344 	if (!af) {
345 		SCTP_DEBUG_PRINTK("sctp_do_bind(sk: %p, newaddr: %p, len: %d) EINVAL\n",
346 				  sk, addr, len);
347 		return -EINVAL;
348 	}
349 
350 	snum = ntohs(addr->v4.sin_port);
351 
352 	SCTP_DEBUG_PRINTK_IPADDR("sctp_do_bind(sk: %p, new addr: ",
353 				 ", port: %d, new port: %d, len: %d)\n",
354 				 sk,
355 				 addr,
356 				 bp->port, snum,
357 				 len);
358 
359 	/* PF specific bind() address verification. */
360 	if (!sp->pf->bind_verify(sp, addr))
361 		return -EADDRNOTAVAIL;
362 
363 	/* We must either be unbound, or bind to the same port.
364 	 * It's OK to allow 0 ports if we are already bound.
365 	 * We'll just inhert an already bound port in this case
366 	 */
367 	if (bp->port) {
368 		if (!snum)
369 			snum = bp->port;
370 		else if (snum != bp->port) {
371 			SCTP_DEBUG_PRINTK("sctp_do_bind:"
372 				  " New port %d does not match existing port "
373 				  "%d.\n", snum, bp->port);
374 			return -EINVAL;
375 		}
376 	}
377 
378 	if (snum && snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE))
379 		return -EACCES;
380 
381 	/* See if the address matches any of the addresses we may have
382 	 * already bound before checking against other endpoints.
383 	 */
384 	if (sctp_bind_addr_match(bp, addr, sp))
385 		return -EINVAL;
386 
387 	/* Make sure we are allowed to bind here.
388 	 * The function sctp_get_port_local() does duplicate address
389 	 * detection.
390 	 */
391 	addr->v4.sin_port = htons(snum);
392 	if ((ret = sctp_get_port_local(sk, addr))) {
393 		return -EADDRINUSE;
394 	}
395 
396 	/* Refresh ephemeral port.  */
397 	if (!bp->port)
398 		bp->port = inet_sk(sk)->inet_num;
399 
400 	/* Add the address to the bind address list.
401 	 * Use GFP_ATOMIC since BHs will be disabled.
402 	 */
403 	ret = sctp_add_bind_addr(bp, addr, SCTP_ADDR_SRC, GFP_ATOMIC);
404 
405 	/* Copy back into socket for getsockname() use. */
406 	if (!ret) {
407 		inet_sk(sk)->inet_sport = htons(inet_sk(sk)->inet_num);
408 		af->to_sk_saddr(addr, sk);
409 	}
410 
411 	return ret;
412 }
413 
414  /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
415  *
416  * R1) One and only one ASCONF Chunk MAY be in transit and unacknowledged
417  * at any one time.  If a sender, after sending an ASCONF chunk, decides
418  * it needs to transfer another ASCONF Chunk, it MUST wait until the
419  * ASCONF-ACK Chunk returns from the previous ASCONF Chunk before sending a
420  * subsequent ASCONF. Note this restriction binds each side, so at any
421  * time two ASCONF may be in-transit on any given association (one sent
422  * from each endpoint).
423  */
424 static int sctp_send_asconf(struct sctp_association *asoc,
425 			    struct sctp_chunk *chunk)
426 {
427 	int		retval = 0;
428 
429 	/* If there is an outstanding ASCONF chunk, queue it for later
430 	 * transmission.
431 	 */
432 	if (asoc->addip_last_asconf) {
433 		list_add_tail(&chunk->list, &asoc->addip_chunk_list);
434 		goto out;
435 	}
436 
437 	/* Hold the chunk until an ASCONF_ACK is received. */
438 	sctp_chunk_hold(chunk);
439 	retval = sctp_primitive_ASCONF(asoc, chunk);
440 	if (retval)
441 		sctp_chunk_free(chunk);
442 	else
443 		asoc->addip_last_asconf = chunk;
444 
445 out:
446 	return retval;
447 }
448 
449 /* Add a list of addresses as bind addresses to local endpoint or
450  * association.
451  *
452  * Basically run through each address specified in the addrs/addrcnt
453  * array/length pair, determine if it is IPv6 or IPv4 and call
454  * sctp_do_bind() on it.
455  *
456  * If any of them fails, then the operation will be reversed and the
457  * ones that were added will be removed.
458  *
459  * Only sctp_setsockopt_bindx() is supposed to call this function.
460  */
461 static int sctp_bindx_add(struct sock *sk, struct sockaddr *addrs, int addrcnt)
462 {
463 	int cnt;
464 	int retval = 0;
465 	void *addr_buf;
466 	struct sockaddr *sa_addr;
467 	struct sctp_af *af;
468 
469 	SCTP_DEBUG_PRINTK("sctp_bindx_add (sk: %p, addrs: %p, addrcnt: %d)\n",
470 			  sk, addrs, addrcnt);
471 
472 	addr_buf = addrs;
473 	for (cnt = 0; cnt < addrcnt; cnt++) {
474 		/* The list may contain either IPv4 or IPv6 address;
475 		 * determine the address length for walking thru the list.
476 		 */
477 		sa_addr = (struct sockaddr *)addr_buf;
478 		af = sctp_get_af_specific(sa_addr->sa_family);
479 		if (!af) {
480 			retval = -EINVAL;
481 			goto err_bindx_add;
482 		}
483 
484 		retval = sctp_do_bind(sk, (union sctp_addr *)sa_addr,
485 				      af->sockaddr_len);
486 
487 		addr_buf += af->sockaddr_len;
488 
489 err_bindx_add:
490 		if (retval < 0) {
491 			/* Failed. Cleanup the ones that have been added */
492 			if (cnt > 0)
493 				sctp_bindx_rem(sk, addrs, cnt);
494 			return retval;
495 		}
496 	}
497 
498 	return retval;
499 }
500 
501 /* Send an ASCONF chunk with Add IP address parameters to all the peers of the
502  * associations that are part of the endpoint indicating that a list of local
503  * addresses are added to the endpoint.
504  *
505  * If any of the addresses is already in the bind address list of the
506  * association, we do not send the chunk for that association.  But it will not
507  * affect other associations.
508  *
509  * Only sctp_setsockopt_bindx() is supposed to call this function.
510  */
511 static int sctp_send_asconf_add_ip(struct sock		*sk,
512 				   struct sockaddr	*addrs,
513 				   int 			addrcnt)
514 {
515 	struct sctp_sock		*sp;
516 	struct sctp_endpoint		*ep;
517 	struct sctp_association		*asoc;
518 	struct sctp_bind_addr		*bp;
519 	struct sctp_chunk		*chunk;
520 	struct sctp_sockaddr_entry	*laddr;
521 	union sctp_addr			*addr;
522 	union sctp_addr			saveaddr;
523 	void				*addr_buf;
524 	struct sctp_af			*af;
525 	struct list_head		*p;
526 	int 				i;
527 	int 				retval = 0;
528 
529 	if (!sctp_addip_enable)
530 		return retval;
531 
532 	sp = sctp_sk(sk);
533 	ep = sp->ep;
534 
535 	SCTP_DEBUG_PRINTK("%s: (sk: %p, addrs: %p, addrcnt: %d)\n",
536 			  __func__, sk, addrs, addrcnt);
537 
538 	list_for_each_entry(asoc, &ep->asocs, asocs) {
539 
540 		if (!asoc->peer.asconf_capable)
541 			continue;
542 
543 		if (asoc->peer.addip_disabled_mask & SCTP_PARAM_ADD_IP)
544 			continue;
545 
546 		if (!sctp_state(asoc, ESTABLISHED))
547 			continue;
548 
549 		/* Check if any address in the packed array of addresses is
550 		 * in the bind address list of the association. If so,
551 		 * do not send the asconf chunk to its peer, but continue with
552 		 * other associations.
553 		 */
554 		addr_buf = addrs;
555 		for (i = 0; i < addrcnt; i++) {
556 			addr = (union sctp_addr *)addr_buf;
557 			af = sctp_get_af_specific(addr->v4.sin_family);
558 			if (!af) {
559 				retval = -EINVAL;
560 				goto out;
561 			}
562 
563 			if (sctp_assoc_lookup_laddr(asoc, addr))
564 				break;
565 
566 			addr_buf += af->sockaddr_len;
567 		}
568 		if (i < addrcnt)
569 			continue;
570 
571 		/* Use the first valid address in bind addr list of
572 		 * association as Address Parameter of ASCONF CHUNK.
573 		 */
574 		bp = &asoc->base.bind_addr;
575 		p = bp->address_list.next;
576 		laddr = list_entry(p, struct sctp_sockaddr_entry, list);
577 		chunk = sctp_make_asconf_update_ip(asoc, &laddr->a, addrs,
578 						   addrcnt, SCTP_PARAM_ADD_IP);
579 		if (!chunk) {
580 			retval = -ENOMEM;
581 			goto out;
582 		}
583 
584 		retval = sctp_send_asconf(asoc, chunk);
585 		if (retval)
586 			goto out;
587 
588 		/* Add the new addresses to the bind address list with
589 		 * use_as_src set to 0.
590 		 */
591 		addr_buf = addrs;
592 		for (i = 0; i < addrcnt; i++) {
593 			addr = (union sctp_addr *)addr_buf;
594 			af = sctp_get_af_specific(addr->v4.sin_family);
595 			memcpy(&saveaddr, addr, af->sockaddr_len);
596 			retval = sctp_add_bind_addr(bp, &saveaddr,
597 						    SCTP_ADDR_NEW, GFP_ATOMIC);
598 			addr_buf += af->sockaddr_len;
599 		}
600 	}
601 
602 out:
603 	return retval;
604 }
605 
606 /* Remove a list of addresses from bind addresses list.  Do not remove the
607  * last address.
608  *
609  * Basically run through each address specified in the addrs/addrcnt
610  * array/length pair, determine if it is IPv6 or IPv4 and call
611  * sctp_del_bind() on it.
612  *
613  * If any of them fails, then the operation will be reversed and the
614  * ones that were removed will be added back.
615  *
616  * At least one address has to be left; if only one address is
617  * available, the operation will return -EBUSY.
618  *
619  * Only sctp_setsockopt_bindx() is supposed to call this function.
620  */
621 static int sctp_bindx_rem(struct sock *sk, struct sockaddr *addrs, int addrcnt)
622 {
623 	struct sctp_sock *sp = sctp_sk(sk);
624 	struct sctp_endpoint *ep = sp->ep;
625 	int cnt;
626 	struct sctp_bind_addr *bp = &ep->base.bind_addr;
627 	int retval = 0;
628 	void *addr_buf;
629 	union sctp_addr *sa_addr;
630 	struct sctp_af *af;
631 
632 	SCTP_DEBUG_PRINTK("sctp_bindx_rem (sk: %p, addrs: %p, addrcnt: %d)\n",
633 			  sk, addrs, addrcnt);
634 
635 	addr_buf = addrs;
636 	for (cnt = 0; cnt < addrcnt; cnt++) {
637 		/* If the bind address list is empty or if there is only one
638 		 * bind address, there is nothing more to be removed (we need
639 		 * at least one address here).
640 		 */
641 		if (list_empty(&bp->address_list) ||
642 		    (sctp_list_single_entry(&bp->address_list))) {
643 			retval = -EBUSY;
644 			goto err_bindx_rem;
645 		}
646 
647 		sa_addr = (union sctp_addr *)addr_buf;
648 		af = sctp_get_af_specific(sa_addr->sa.sa_family);
649 		if (!af) {
650 			retval = -EINVAL;
651 			goto err_bindx_rem;
652 		}
653 
654 		if (!af->addr_valid(sa_addr, sp, NULL)) {
655 			retval = -EADDRNOTAVAIL;
656 			goto err_bindx_rem;
657 		}
658 
659 		if (sa_addr->v4.sin_port != htons(bp->port)) {
660 			retval = -EINVAL;
661 			goto err_bindx_rem;
662 		}
663 
664 		/* FIXME - There is probably a need to check if sk->sk_saddr and
665 		 * sk->sk_rcv_addr are currently set to one of the addresses to
666 		 * be removed. This is something which needs to be looked into
667 		 * when we are fixing the outstanding issues with multi-homing
668 		 * socket routing and failover schemes. Refer to comments in
669 		 * sctp_do_bind(). -daisy
670 		 */
671 		retval = sctp_del_bind_addr(bp, sa_addr);
672 
673 		addr_buf += af->sockaddr_len;
674 err_bindx_rem:
675 		if (retval < 0) {
676 			/* Failed. Add the ones that has been removed back */
677 			if (cnt > 0)
678 				sctp_bindx_add(sk, addrs, cnt);
679 			return retval;
680 		}
681 	}
682 
683 	return retval;
684 }
685 
686 /* Send an ASCONF chunk with Delete IP address parameters to all the peers of
687  * the associations that are part of the endpoint indicating that a list of
688  * local addresses are removed from the endpoint.
689  *
690  * If any of the addresses is already in the bind address list of the
691  * association, we do not send the chunk for that association.  But it will not
692  * affect other associations.
693  *
694  * Only sctp_setsockopt_bindx() is supposed to call this function.
695  */
696 static int sctp_send_asconf_del_ip(struct sock		*sk,
697 				   struct sockaddr	*addrs,
698 				   int			addrcnt)
699 {
700 	struct sctp_sock	*sp;
701 	struct sctp_endpoint	*ep;
702 	struct sctp_association	*asoc;
703 	struct sctp_transport	*transport;
704 	struct sctp_bind_addr	*bp;
705 	struct sctp_chunk	*chunk;
706 	union sctp_addr		*laddr;
707 	void			*addr_buf;
708 	struct sctp_af		*af;
709 	struct sctp_sockaddr_entry *saddr;
710 	int 			i;
711 	int 			retval = 0;
712 
713 	if (!sctp_addip_enable)
714 		return retval;
715 
716 	sp = sctp_sk(sk);
717 	ep = sp->ep;
718 
719 	SCTP_DEBUG_PRINTK("%s: (sk: %p, addrs: %p, addrcnt: %d)\n",
720 			  __func__, sk, addrs, addrcnt);
721 
722 	list_for_each_entry(asoc, &ep->asocs, asocs) {
723 
724 		if (!asoc->peer.asconf_capable)
725 			continue;
726 
727 		if (asoc->peer.addip_disabled_mask & SCTP_PARAM_DEL_IP)
728 			continue;
729 
730 		if (!sctp_state(asoc, ESTABLISHED))
731 			continue;
732 
733 		/* Check if any address in the packed array of addresses is
734 		 * not present in the bind address list of the association.
735 		 * If so, do not send the asconf chunk to its peer, but
736 		 * continue with other associations.
737 		 */
738 		addr_buf = addrs;
739 		for (i = 0; i < addrcnt; i++) {
740 			laddr = (union sctp_addr *)addr_buf;
741 			af = sctp_get_af_specific(laddr->v4.sin_family);
742 			if (!af) {
743 				retval = -EINVAL;
744 				goto out;
745 			}
746 
747 			if (!sctp_assoc_lookup_laddr(asoc, laddr))
748 				break;
749 
750 			addr_buf += af->sockaddr_len;
751 		}
752 		if (i < addrcnt)
753 			continue;
754 
755 		/* Find one address in the association's bind address list
756 		 * that is not in the packed array of addresses. This is to
757 		 * make sure that we do not delete all the addresses in the
758 		 * association.
759 		 */
760 		bp = &asoc->base.bind_addr;
761 		laddr = sctp_find_unmatch_addr(bp, (union sctp_addr *)addrs,
762 					       addrcnt, sp);
763 		if (!laddr)
764 			continue;
765 
766 		/* We do not need RCU protection throughout this loop
767 		 * because this is done under a socket lock from the
768 		 * setsockopt call.
769 		 */
770 		chunk = sctp_make_asconf_update_ip(asoc, laddr, addrs, addrcnt,
771 						   SCTP_PARAM_DEL_IP);
772 		if (!chunk) {
773 			retval = -ENOMEM;
774 			goto out;
775 		}
776 
777 		/* Reset use_as_src flag for the addresses in the bind address
778 		 * list that are to be deleted.
779 		 */
780 		addr_buf = addrs;
781 		for (i = 0; i < addrcnt; i++) {
782 			laddr = (union sctp_addr *)addr_buf;
783 			af = sctp_get_af_specific(laddr->v4.sin_family);
784 			list_for_each_entry(saddr, &bp->address_list, list) {
785 				if (sctp_cmp_addr_exact(&saddr->a, laddr))
786 					saddr->state = SCTP_ADDR_DEL;
787 			}
788 			addr_buf += af->sockaddr_len;
789 		}
790 
791 		/* Update the route and saddr entries for all the transports
792 		 * as some of the addresses in the bind address list are
793 		 * about to be deleted and cannot be used as source addresses.
794 		 */
795 		list_for_each_entry(transport, &asoc->peer.transport_addr_list,
796 					transports) {
797 			dst_release(transport->dst);
798 			sctp_transport_route(transport, NULL,
799 					     sctp_sk(asoc->base.sk));
800 		}
801 
802 		retval = sctp_send_asconf(asoc, chunk);
803 	}
804 out:
805 	return retval;
806 }
807 
808 /* Helper for tunneling sctp_bindx() requests through sctp_setsockopt()
809  *
810  * API 8.1
811  * int sctp_bindx(int sd, struct sockaddr *addrs, int addrcnt,
812  *                int flags);
813  *
814  * If sd is an IPv4 socket, the addresses passed must be IPv4 addresses.
815  * If the sd is an IPv6 socket, the addresses passed can either be IPv4
816  * or IPv6 addresses.
817  *
818  * A single address may be specified as INADDR_ANY or IN6ADDR_ANY, see
819  * Section 3.1.2 for this usage.
820  *
821  * addrs is a pointer to an array of one or more socket addresses. Each
822  * address is contained in its appropriate structure (i.e. struct
823  * sockaddr_in or struct sockaddr_in6) the family of the address type
824  * must be used to distinguish the address length (note that this
825  * representation is termed a "packed array" of addresses). The caller
826  * specifies the number of addresses in the array with addrcnt.
827  *
828  * On success, sctp_bindx() returns 0. On failure, sctp_bindx() returns
829  * -1, and sets errno to the appropriate error code.
830  *
831  * For SCTP, the port given in each socket address must be the same, or
832  * sctp_bindx() will fail, setting errno to EINVAL.
833  *
834  * The flags parameter is formed from the bitwise OR of zero or more of
835  * the following currently defined flags:
836  *
837  * SCTP_BINDX_ADD_ADDR
838  *
839  * SCTP_BINDX_REM_ADDR
840  *
841  * SCTP_BINDX_ADD_ADDR directs SCTP to add the given addresses to the
842  * association, and SCTP_BINDX_REM_ADDR directs SCTP to remove the given
843  * addresses from the association. The two flags are mutually exclusive;
844  * if both are given, sctp_bindx() will fail with EINVAL. A caller may
845  * not remove all addresses from an association; sctp_bindx() will
846  * reject such an attempt with EINVAL.
847  *
848  * An application can use sctp_bindx(SCTP_BINDX_ADD_ADDR) to associate
849  * additional addresses with an endpoint after calling bind().  Or use
850  * sctp_bindx(SCTP_BINDX_REM_ADDR) to remove some addresses a listening
851  * socket is associated with so that no new association accepted will be
852  * associated with those addresses. If the endpoint supports dynamic
853  * address a SCTP_BINDX_REM_ADDR or SCTP_BINDX_ADD_ADDR may cause a
854  * endpoint to send the appropriate message to the peer to change the
855  * peers address lists.
856  *
857  * Adding and removing addresses from a connected association is
858  * optional functionality. Implementations that do not support this
859  * functionality should return EOPNOTSUPP.
860  *
861  * Basically do nothing but copying the addresses from user to kernel
862  * land and invoking either sctp_bindx_add() or sctp_bindx_rem() on the sk.
863  * This is used for tunneling the sctp_bindx() request through sctp_setsockopt()
864  * from userspace.
865  *
866  * We don't use copy_from_user() for optimization: we first do the
867  * sanity checks (buffer size -fast- and access check-healthy
868  * pointer); if all of those succeed, then we can alloc the memory
869  * (expensive operation) needed to copy the data to kernel. Then we do
870  * the copying without checking the user space area
871  * (__copy_from_user()).
872  *
873  * On exit there is no need to do sockfd_put(), sys_setsockopt() does
874  * it.
875  *
876  * sk        The sk of the socket
877  * addrs     The pointer to the addresses in user land
878  * addrssize Size of the addrs buffer
879  * op        Operation to perform (add or remove, see the flags of
880  *           sctp_bindx)
881  *
882  * Returns 0 if ok, <0 errno code on error.
883  */
884 SCTP_STATIC int sctp_setsockopt_bindx(struct sock* sk,
885 				      struct sockaddr __user *addrs,
886 				      int addrs_size, int op)
887 {
888 	struct sockaddr *kaddrs;
889 	int err;
890 	int addrcnt = 0;
891 	int walk_size = 0;
892 	struct sockaddr *sa_addr;
893 	void *addr_buf;
894 	struct sctp_af *af;
895 
896 	SCTP_DEBUG_PRINTK("sctp_setsocktopt_bindx: sk %p addrs %p"
897 			  " addrs_size %d opt %d\n", sk, addrs, addrs_size, op);
898 
899 	if (unlikely(addrs_size <= 0))
900 		return -EINVAL;
901 
902 	/* Check the user passed a healthy pointer.  */
903 	if (unlikely(!access_ok(VERIFY_READ, addrs, addrs_size)))
904 		return -EFAULT;
905 
906 	/* Alloc space for the address array in kernel memory.  */
907 	kaddrs = kmalloc(addrs_size, GFP_KERNEL);
908 	if (unlikely(!kaddrs))
909 		return -ENOMEM;
910 
911 	if (__copy_from_user(kaddrs, addrs, addrs_size)) {
912 		kfree(kaddrs);
913 		return -EFAULT;
914 	}
915 
916 	/* Walk through the addrs buffer and count the number of addresses. */
917 	addr_buf = kaddrs;
918 	while (walk_size < addrs_size) {
919 		if (walk_size + sizeof(sa_family_t) > addrs_size) {
920 			kfree(kaddrs);
921 			return -EINVAL;
922 		}
923 
924 		sa_addr = (struct sockaddr *)addr_buf;
925 		af = sctp_get_af_specific(sa_addr->sa_family);
926 
927 		/* If the address family is not supported or if this address
928 		 * causes the address buffer to overflow return EINVAL.
929 		 */
930 		if (!af || (walk_size + af->sockaddr_len) > addrs_size) {
931 			kfree(kaddrs);
932 			return -EINVAL;
933 		}
934 		addrcnt++;
935 		addr_buf += af->sockaddr_len;
936 		walk_size += af->sockaddr_len;
937 	}
938 
939 	/* Do the work. */
940 	switch (op) {
941 	case SCTP_BINDX_ADD_ADDR:
942 		err = sctp_bindx_add(sk, kaddrs, addrcnt);
943 		if (err)
944 			goto out;
945 		err = sctp_send_asconf_add_ip(sk, kaddrs, addrcnt);
946 		break;
947 
948 	case SCTP_BINDX_REM_ADDR:
949 		err = sctp_bindx_rem(sk, kaddrs, addrcnt);
950 		if (err)
951 			goto out;
952 		err = sctp_send_asconf_del_ip(sk, kaddrs, addrcnt);
953 		break;
954 
955 	default:
956 		err = -EINVAL;
957 		break;
958 	}
959 
960 out:
961 	kfree(kaddrs);
962 
963 	return err;
964 }
965 
966 /* __sctp_connect(struct sock* sk, struct sockaddr *kaddrs, int addrs_size)
967  *
968  * Common routine for handling connect() and sctp_connectx().
969  * Connect will come in with just a single address.
970  */
971 static int __sctp_connect(struct sock* sk,
972 			  struct sockaddr *kaddrs,
973 			  int addrs_size,
974 			  sctp_assoc_t *assoc_id)
975 {
976 	struct sctp_sock *sp;
977 	struct sctp_endpoint *ep;
978 	struct sctp_association *asoc = NULL;
979 	struct sctp_association *asoc2;
980 	struct sctp_transport *transport;
981 	union sctp_addr to;
982 	struct sctp_af *af;
983 	sctp_scope_t scope;
984 	long timeo;
985 	int err = 0;
986 	int addrcnt = 0;
987 	int walk_size = 0;
988 	union sctp_addr *sa_addr = NULL;
989 	void *addr_buf;
990 	unsigned short port;
991 	unsigned int f_flags = 0;
992 
993 	sp = sctp_sk(sk);
994 	ep = sp->ep;
995 
996 	/* connect() cannot be done on a socket that is already in ESTABLISHED
997 	 * state - UDP-style peeled off socket or a TCP-style socket that
998 	 * is already connected.
999 	 * It cannot be done even on a TCP-style listening socket.
1000 	 */
1001 	if (sctp_sstate(sk, ESTABLISHED) ||
1002 	    (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))) {
1003 		err = -EISCONN;
1004 		goto out_free;
1005 	}
1006 
1007 	/* Walk through the addrs buffer and count the number of addresses. */
1008 	addr_buf = kaddrs;
1009 	while (walk_size < addrs_size) {
1010 		if (walk_size + sizeof(sa_family_t) > addrs_size) {
1011 			err = -EINVAL;
1012 			goto out_free;
1013 		}
1014 
1015 		sa_addr = (union sctp_addr *)addr_buf;
1016 		af = sctp_get_af_specific(sa_addr->sa.sa_family);
1017 
1018 		/* If the address family is not supported or if this address
1019 		 * causes the address buffer to overflow return EINVAL.
1020 		 */
1021 		if (!af || (walk_size + af->sockaddr_len) > addrs_size) {
1022 			err = -EINVAL;
1023 			goto out_free;
1024 		}
1025 
1026 		port = ntohs(sa_addr->v4.sin_port);
1027 
1028 		/* Save current address so we can work with it */
1029 		memcpy(&to, sa_addr, af->sockaddr_len);
1030 
1031 		err = sctp_verify_addr(sk, &to, af->sockaddr_len);
1032 		if (err)
1033 			goto out_free;
1034 
1035 		/* Make sure the destination port is correctly set
1036 		 * in all addresses.
1037 		 */
1038 		if (asoc && asoc->peer.port && asoc->peer.port != port)
1039 			goto out_free;
1040 
1041 
1042 		/* Check if there already is a matching association on the
1043 		 * endpoint (other than the one created here).
1044 		 */
1045 		asoc2 = sctp_endpoint_lookup_assoc(ep, &to, &transport);
1046 		if (asoc2 && asoc2 != asoc) {
1047 			if (asoc2->state >= SCTP_STATE_ESTABLISHED)
1048 				err = -EISCONN;
1049 			else
1050 				err = -EALREADY;
1051 			goto out_free;
1052 		}
1053 
1054 		/* If we could not find a matching association on the endpoint,
1055 		 * make sure that there is no peeled-off association matching
1056 		 * the peer address even on another socket.
1057 		 */
1058 		if (sctp_endpoint_is_peeled_off(ep, &to)) {
1059 			err = -EADDRNOTAVAIL;
1060 			goto out_free;
1061 		}
1062 
1063 		if (!asoc) {
1064 			/* If a bind() or sctp_bindx() is not called prior to
1065 			 * an sctp_connectx() call, the system picks an
1066 			 * ephemeral port and will choose an address set
1067 			 * equivalent to binding with a wildcard address.
1068 			 */
1069 			if (!ep->base.bind_addr.port) {
1070 				if (sctp_autobind(sk)) {
1071 					err = -EAGAIN;
1072 					goto out_free;
1073 				}
1074 			} else {
1075 				/*
1076 				 * If an unprivileged user inherits a 1-many
1077 				 * style socket with open associations on a
1078 				 * privileged port, it MAY be permitted to
1079 				 * accept new associations, but it SHOULD NOT
1080 				 * be permitted to open new associations.
1081 				 */
1082 				if (ep->base.bind_addr.port < PROT_SOCK &&
1083 				    !capable(CAP_NET_BIND_SERVICE)) {
1084 					err = -EACCES;
1085 					goto out_free;
1086 				}
1087 			}
1088 
1089 			scope = sctp_scope(&to);
1090 			asoc = sctp_association_new(ep, sk, scope, GFP_KERNEL);
1091 			if (!asoc) {
1092 				err = -ENOMEM;
1093 				goto out_free;
1094 			}
1095 
1096 			err = sctp_assoc_set_bind_addr_from_ep(asoc, scope,
1097 							      GFP_KERNEL);
1098 			if (err < 0) {
1099 				goto out_free;
1100 			}
1101 
1102 		}
1103 
1104 		/* Prime the peer's transport structures.  */
1105 		transport = sctp_assoc_add_peer(asoc, &to, GFP_KERNEL,
1106 						SCTP_UNKNOWN);
1107 		if (!transport) {
1108 			err = -ENOMEM;
1109 			goto out_free;
1110 		}
1111 
1112 		addrcnt++;
1113 		addr_buf += af->sockaddr_len;
1114 		walk_size += af->sockaddr_len;
1115 	}
1116 
1117 	/* In case the user of sctp_connectx() wants an association
1118 	 * id back, assign one now.
1119 	 */
1120 	if (assoc_id) {
1121 		err = sctp_assoc_set_id(asoc, GFP_KERNEL);
1122 		if (err < 0)
1123 			goto out_free;
1124 	}
1125 
1126 	err = sctp_primitive_ASSOCIATE(asoc, NULL);
1127 	if (err < 0) {
1128 		goto out_free;
1129 	}
1130 
1131 	/* Initialize sk's dport and daddr for getpeername() */
1132 	inet_sk(sk)->inet_dport = htons(asoc->peer.port);
1133 	af = sctp_get_af_specific(sa_addr->sa.sa_family);
1134 	af->to_sk_daddr(sa_addr, sk);
1135 	sk->sk_err = 0;
1136 
1137 	/* in-kernel sockets don't generally have a file allocated to them
1138 	 * if all they do is call sock_create_kern().
1139 	 */
1140 	if (sk->sk_socket->file)
1141 		f_flags = sk->sk_socket->file->f_flags;
1142 
1143 	timeo = sock_sndtimeo(sk, f_flags & O_NONBLOCK);
1144 
1145 	err = sctp_wait_for_connect(asoc, &timeo);
1146 	if ((err == 0 || err == -EINPROGRESS) && assoc_id)
1147 		*assoc_id = asoc->assoc_id;
1148 
1149 	/* Don't free association on exit. */
1150 	asoc = NULL;
1151 
1152 out_free:
1153 
1154 	SCTP_DEBUG_PRINTK("About to exit __sctp_connect() free asoc: %p"
1155 			  " kaddrs: %p err: %d\n",
1156 			  asoc, kaddrs, err);
1157 	if (asoc)
1158 		sctp_association_free(asoc);
1159 	return err;
1160 }
1161 
1162 /* Helper for tunneling sctp_connectx() requests through sctp_setsockopt()
1163  *
1164  * API 8.9
1165  * int sctp_connectx(int sd, struct sockaddr *addrs, int addrcnt,
1166  * 			sctp_assoc_t *asoc);
1167  *
1168  * If sd is an IPv4 socket, the addresses passed must be IPv4 addresses.
1169  * If the sd is an IPv6 socket, the addresses passed can either be IPv4
1170  * or IPv6 addresses.
1171  *
1172  * A single address may be specified as INADDR_ANY or IN6ADDR_ANY, see
1173  * Section 3.1.2 for this usage.
1174  *
1175  * addrs is a pointer to an array of one or more socket addresses. Each
1176  * address is contained in its appropriate structure (i.e. struct
1177  * sockaddr_in or struct sockaddr_in6) the family of the address type
1178  * must be used to distengish the address length (note that this
1179  * representation is termed a "packed array" of addresses). The caller
1180  * specifies the number of addresses in the array with addrcnt.
1181  *
1182  * On success, sctp_connectx() returns 0. It also sets the assoc_id to
1183  * the association id of the new association.  On failure, sctp_connectx()
1184  * returns -1, and sets errno to the appropriate error code.  The assoc_id
1185  * is not touched by the kernel.
1186  *
1187  * For SCTP, the port given in each socket address must be the same, or
1188  * sctp_connectx() will fail, setting errno to EINVAL.
1189  *
1190  * An application can use sctp_connectx to initiate an association with
1191  * an endpoint that is multi-homed.  Much like sctp_bindx() this call
1192  * allows a caller to specify multiple addresses at which a peer can be
1193  * reached.  The way the SCTP stack uses the list of addresses to set up
1194  * the association is implementation dependant.  This function only
1195  * specifies that the stack will try to make use of all the addresses in
1196  * the list when needed.
1197  *
1198  * Note that the list of addresses passed in is only used for setting up
1199  * the association.  It does not necessarily equal the set of addresses
1200  * the peer uses for the resulting association.  If the caller wants to
1201  * find out the set of peer addresses, it must use sctp_getpaddrs() to
1202  * retrieve them after the association has been set up.
1203  *
1204  * Basically do nothing but copying the addresses from user to kernel
1205  * land and invoking either sctp_connectx(). This is used for tunneling
1206  * the sctp_connectx() request through sctp_setsockopt() from userspace.
1207  *
1208  * We don't use copy_from_user() for optimization: we first do the
1209  * sanity checks (buffer size -fast- and access check-healthy
1210  * pointer); if all of those succeed, then we can alloc the memory
1211  * (expensive operation) needed to copy the data to kernel. Then we do
1212  * the copying without checking the user space area
1213  * (__copy_from_user()).
1214  *
1215  * On exit there is no need to do sockfd_put(), sys_setsockopt() does
1216  * it.
1217  *
1218  * sk        The sk of the socket
1219  * addrs     The pointer to the addresses in user land
1220  * addrssize Size of the addrs buffer
1221  *
1222  * Returns >=0 if ok, <0 errno code on error.
1223  */
1224 SCTP_STATIC int __sctp_setsockopt_connectx(struct sock* sk,
1225 				      struct sockaddr __user *addrs,
1226 				      int addrs_size,
1227 				      sctp_assoc_t *assoc_id)
1228 {
1229 	int err = 0;
1230 	struct sockaddr *kaddrs;
1231 
1232 	SCTP_DEBUG_PRINTK("%s - sk %p addrs %p addrs_size %d\n",
1233 			  __func__, sk, addrs, addrs_size);
1234 
1235 	if (unlikely(addrs_size <= 0))
1236 		return -EINVAL;
1237 
1238 	/* Check the user passed a healthy pointer.  */
1239 	if (unlikely(!access_ok(VERIFY_READ, addrs, addrs_size)))
1240 		return -EFAULT;
1241 
1242 	/* Alloc space for the address array in kernel memory.  */
1243 	kaddrs = kmalloc(addrs_size, GFP_KERNEL);
1244 	if (unlikely(!kaddrs))
1245 		return -ENOMEM;
1246 
1247 	if (__copy_from_user(kaddrs, addrs, addrs_size)) {
1248 		err = -EFAULT;
1249 	} else {
1250 		err = __sctp_connect(sk, kaddrs, addrs_size, assoc_id);
1251 	}
1252 
1253 	kfree(kaddrs);
1254 
1255 	return err;
1256 }
1257 
1258 /*
1259  * This is an older interface.  It's kept for backward compatibility
1260  * to the option that doesn't provide association id.
1261  */
1262 SCTP_STATIC int sctp_setsockopt_connectx_old(struct sock* sk,
1263 				      struct sockaddr __user *addrs,
1264 				      int addrs_size)
1265 {
1266 	return __sctp_setsockopt_connectx(sk, addrs, addrs_size, NULL);
1267 }
1268 
1269 /*
1270  * New interface for the API.  The since the API is done with a socket
1271  * option, to make it simple we feed back the association id is as a return
1272  * indication to the call.  Error is always negative and association id is
1273  * always positive.
1274  */
1275 SCTP_STATIC int sctp_setsockopt_connectx(struct sock* sk,
1276 				      struct sockaddr __user *addrs,
1277 				      int addrs_size)
1278 {
1279 	sctp_assoc_t assoc_id = 0;
1280 	int err = 0;
1281 
1282 	err = __sctp_setsockopt_connectx(sk, addrs, addrs_size, &assoc_id);
1283 
1284 	if (err)
1285 		return err;
1286 	else
1287 		return assoc_id;
1288 }
1289 
1290 /*
1291  * New (hopefully final) interface for the API.
1292  * We use the sctp_getaddrs_old structure so that use-space library
1293  * can avoid any unnecessary allocations.   The only defferent part
1294  * is that we store the actual length of the address buffer into the
1295  * addrs_num structure member.  That way we can re-use the existing
1296  * code.
1297  */
1298 SCTP_STATIC int sctp_getsockopt_connectx3(struct sock* sk, int len,
1299 					char __user *optval,
1300 					int __user *optlen)
1301 {
1302 	struct sctp_getaddrs_old param;
1303 	sctp_assoc_t assoc_id = 0;
1304 	int err = 0;
1305 
1306 	if (len < sizeof(param))
1307 		return -EINVAL;
1308 
1309 	if (copy_from_user(&param, optval, sizeof(param)))
1310 		return -EFAULT;
1311 
1312 	err = __sctp_setsockopt_connectx(sk,
1313 			(struct sockaddr __user *)param.addrs,
1314 			param.addr_num, &assoc_id);
1315 
1316 	if (err == 0 || err == -EINPROGRESS) {
1317 		if (copy_to_user(optval, &assoc_id, sizeof(assoc_id)))
1318 			return -EFAULT;
1319 		if (put_user(sizeof(assoc_id), optlen))
1320 			return -EFAULT;
1321 	}
1322 
1323 	return err;
1324 }
1325 
1326 /* API 3.1.4 close() - UDP Style Syntax
1327  * Applications use close() to perform graceful shutdown (as described in
1328  * Section 10.1 of [SCTP]) on ALL the associations currently represented
1329  * by a UDP-style socket.
1330  *
1331  * The syntax is
1332  *
1333  *   ret = close(int sd);
1334  *
1335  *   sd      - the socket descriptor of the associations to be closed.
1336  *
1337  * To gracefully shutdown a specific association represented by the
1338  * UDP-style socket, an application should use the sendmsg() call,
1339  * passing no user data, but including the appropriate flag in the
1340  * ancillary data (see Section xxxx).
1341  *
1342  * If sd in the close() call is a branched-off socket representing only
1343  * one association, the shutdown is performed on that association only.
1344  *
1345  * 4.1.6 close() - TCP Style Syntax
1346  *
1347  * Applications use close() to gracefully close down an association.
1348  *
1349  * The syntax is:
1350  *
1351  *    int close(int sd);
1352  *
1353  *      sd      - the socket descriptor of the association to be closed.
1354  *
1355  * After an application calls close() on a socket descriptor, no further
1356  * socket operations will succeed on that descriptor.
1357  *
1358  * API 7.1.4 SO_LINGER
1359  *
1360  * An application using the TCP-style socket can use this option to
1361  * perform the SCTP ABORT primitive.  The linger option structure is:
1362  *
1363  *  struct  linger {
1364  *     int     l_onoff;                // option on/off
1365  *     int     l_linger;               // linger time
1366  * };
1367  *
1368  * To enable the option, set l_onoff to 1.  If the l_linger value is set
1369  * to 0, calling close() is the same as the ABORT primitive.  If the
1370  * value is set to a negative value, the setsockopt() call will return
1371  * an error.  If the value is set to a positive value linger_time, the
1372  * close() can be blocked for at most linger_time ms.  If the graceful
1373  * shutdown phase does not finish during this period, close() will
1374  * return but the graceful shutdown phase continues in the system.
1375  */
1376 SCTP_STATIC void sctp_close(struct sock *sk, long timeout)
1377 {
1378 	struct sctp_endpoint *ep;
1379 	struct sctp_association *asoc;
1380 	struct list_head *pos, *temp;
1381 
1382 	SCTP_DEBUG_PRINTK("sctp_close(sk: 0x%p, timeout:%ld)\n", sk, timeout);
1383 
1384 	sctp_lock_sock(sk);
1385 	sk->sk_shutdown = SHUTDOWN_MASK;
1386 	sk->sk_state = SCTP_SS_CLOSING;
1387 
1388 	ep = sctp_sk(sk)->ep;
1389 
1390 	/* Walk all associations on an endpoint.  */
1391 	list_for_each_safe(pos, temp, &ep->asocs) {
1392 		asoc = list_entry(pos, struct sctp_association, asocs);
1393 
1394 		if (sctp_style(sk, TCP)) {
1395 			/* A closed association can still be in the list if
1396 			 * it belongs to a TCP-style listening socket that is
1397 			 * not yet accepted. If so, free it. If not, send an
1398 			 * ABORT or SHUTDOWN based on the linger options.
1399 			 */
1400 			if (sctp_state(asoc, CLOSED)) {
1401 				sctp_unhash_established(asoc);
1402 				sctp_association_free(asoc);
1403 				continue;
1404 			}
1405 		}
1406 
1407 		if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
1408 			struct sctp_chunk *chunk;
1409 
1410 			chunk = sctp_make_abort_user(asoc, NULL, 0);
1411 			if (chunk)
1412 				sctp_primitive_ABORT(asoc, chunk);
1413 		} else
1414 			sctp_primitive_SHUTDOWN(asoc, NULL);
1415 	}
1416 
1417 	/* Clean up any skbs sitting on the receive queue.  */
1418 	sctp_queue_purge_ulpevents(&sk->sk_receive_queue);
1419 	sctp_queue_purge_ulpevents(&sctp_sk(sk)->pd_lobby);
1420 
1421 	/* On a TCP-style socket, block for at most linger_time if set. */
1422 	if (sctp_style(sk, TCP) && timeout)
1423 		sctp_wait_for_close(sk, timeout);
1424 
1425 	/* This will run the backlog queue.  */
1426 	sctp_release_sock(sk);
1427 
1428 	/* Supposedly, no process has access to the socket, but
1429 	 * the net layers still may.
1430 	 */
1431 	sctp_local_bh_disable();
1432 	sctp_bh_lock_sock(sk);
1433 
1434 	/* Hold the sock, since sk_common_release() will put sock_put()
1435 	 * and we have just a little more cleanup.
1436 	 */
1437 	sock_hold(sk);
1438 	sk_common_release(sk);
1439 
1440 	sctp_bh_unlock_sock(sk);
1441 	sctp_local_bh_enable();
1442 
1443 	sock_put(sk);
1444 
1445 	SCTP_DBG_OBJCNT_DEC(sock);
1446 }
1447 
1448 /* Handle EPIPE error. */
1449 static int sctp_error(struct sock *sk, int flags, int err)
1450 {
1451 	if (err == -EPIPE)
1452 		err = sock_error(sk) ? : -EPIPE;
1453 	if (err == -EPIPE && !(flags & MSG_NOSIGNAL))
1454 		send_sig(SIGPIPE, current, 0);
1455 	return err;
1456 }
1457 
1458 /* API 3.1.3 sendmsg() - UDP Style Syntax
1459  *
1460  * An application uses sendmsg() and recvmsg() calls to transmit data to
1461  * and receive data from its peer.
1462  *
1463  *  ssize_t sendmsg(int socket, const struct msghdr *message,
1464  *                  int flags);
1465  *
1466  *  socket  - the socket descriptor of the endpoint.
1467  *  message - pointer to the msghdr structure which contains a single
1468  *            user message and possibly some ancillary data.
1469  *
1470  *            See Section 5 for complete description of the data
1471  *            structures.
1472  *
1473  *  flags   - flags sent or received with the user message, see Section
1474  *            5 for complete description of the flags.
1475  *
1476  * Note:  This function could use a rewrite especially when explicit
1477  * connect support comes in.
1478  */
1479 /* BUG:  We do not implement the equivalent of sk_stream_wait_memory(). */
1480 
1481 SCTP_STATIC int sctp_msghdr_parse(const struct msghdr *, sctp_cmsgs_t *);
1482 
1483 SCTP_STATIC int sctp_sendmsg(struct kiocb *iocb, struct sock *sk,
1484 			     struct msghdr *msg, size_t msg_len)
1485 {
1486 	struct sctp_sock *sp;
1487 	struct sctp_endpoint *ep;
1488 	struct sctp_association *new_asoc=NULL, *asoc=NULL;
1489 	struct sctp_transport *transport, *chunk_tp;
1490 	struct sctp_chunk *chunk;
1491 	union sctp_addr to;
1492 	struct sockaddr *msg_name = NULL;
1493 	struct sctp_sndrcvinfo default_sinfo = { 0 };
1494 	struct sctp_sndrcvinfo *sinfo;
1495 	struct sctp_initmsg *sinit;
1496 	sctp_assoc_t associd = 0;
1497 	sctp_cmsgs_t cmsgs = { NULL };
1498 	int err;
1499 	sctp_scope_t scope;
1500 	long timeo;
1501 	__u16 sinfo_flags = 0;
1502 	struct sctp_datamsg *datamsg;
1503 	int msg_flags = msg->msg_flags;
1504 
1505 	SCTP_DEBUG_PRINTK("sctp_sendmsg(sk: %p, msg: %p, msg_len: %zu)\n",
1506 			  sk, msg, msg_len);
1507 
1508 	err = 0;
1509 	sp = sctp_sk(sk);
1510 	ep = sp->ep;
1511 
1512 	SCTP_DEBUG_PRINTK("Using endpoint: %p.\n", ep);
1513 
1514 	/* We cannot send a message over a TCP-style listening socket. */
1515 	if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING)) {
1516 		err = -EPIPE;
1517 		goto out_nounlock;
1518 	}
1519 
1520 	/* Parse out the SCTP CMSGs.  */
1521 	err = sctp_msghdr_parse(msg, &cmsgs);
1522 
1523 	if (err) {
1524 		SCTP_DEBUG_PRINTK("msghdr parse err = %x\n", err);
1525 		goto out_nounlock;
1526 	}
1527 
1528 	/* Fetch the destination address for this packet.  This
1529 	 * address only selects the association--it is not necessarily
1530 	 * the address we will send to.
1531 	 * For a peeled-off socket, msg_name is ignored.
1532 	 */
1533 	if (!sctp_style(sk, UDP_HIGH_BANDWIDTH) && msg->msg_name) {
1534 		int msg_namelen = msg->msg_namelen;
1535 
1536 		err = sctp_verify_addr(sk, (union sctp_addr *)msg->msg_name,
1537 				       msg_namelen);
1538 		if (err)
1539 			return err;
1540 
1541 		if (msg_namelen > sizeof(to))
1542 			msg_namelen = sizeof(to);
1543 		memcpy(&to, msg->msg_name, msg_namelen);
1544 		msg_name = msg->msg_name;
1545 	}
1546 
1547 	sinfo = cmsgs.info;
1548 	sinit = cmsgs.init;
1549 
1550 	/* Did the user specify SNDRCVINFO?  */
1551 	if (sinfo) {
1552 		sinfo_flags = sinfo->sinfo_flags;
1553 		associd = sinfo->sinfo_assoc_id;
1554 	}
1555 
1556 	SCTP_DEBUG_PRINTK("msg_len: %zu, sinfo_flags: 0x%x\n",
1557 			  msg_len, sinfo_flags);
1558 
1559 	/* SCTP_EOF or SCTP_ABORT cannot be set on a TCP-style socket. */
1560 	if (sctp_style(sk, TCP) && (sinfo_flags & (SCTP_EOF | SCTP_ABORT))) {
1561 		err = -EINVAL;
1562 		goto out_nounlock;
1563 	}
1564 
1565 	/* If SCTP_EOF is set, no data can be sent. Disallow sending zero
1566 	 * length messages when SCTP_EOF|SCTP_ABORT is not set.
1567 	 * If SCTP_ABORT is set, the message length could be non zero with
1568 	 * the msg_iov set to the user abort reason.
1569 	 */
1570 	if (((sinfo_flags & SCTP_EOF) && (msg_len > 0)) ||
1571 	    (!(sinfo_flags & (SCTP_EOF|SCTP_ABORT)) && (msg_len == 0))) {
1572 		err = -EINVAL;
1573 		goto out_nounlock;
1574 	}
1575 
1576 	/* If SCTP_ADDR_OVER is set, there must be an address
1577 	 * specified in msg_name.
1578 	 */
1579 	if ((sinfo_flags & SCTP_ADDR_OVER) && (!msg->msg_name)) {
1580 		err = -EINVAL;
1581 		goto out_nounlock;
1582 	}
1583 
1584 	transport = NULL;
1585 
1586 	SCTP_DEBUG_PRINTK("About to look up association.\n");
1587 
1588 	sctp_lock_sock(sk);
1589 
1590 	/* If a msg_name has been specified, assume this is to be used.  */
1591 	if (msg_name) {
1592 		/* Look for a matching association on the endpoint. */
1593 		asoc = sctp_endpoint_lookup_assoc(ep, &to, &transport);
1594 		if (!asoc) {
1595 			/* If we could not find a matching association on the
1596 			 * endpoint, make sure that it is not a TCP-style
1597 			 * socket that already has an association or there is
1598 			 * no peeled-off association on another socket.
1599 			 */
1600 			if ((sctp_style(sk, TCP) &&
1601 			     sctp_sstate(sk, ESTABLISHED)) ||
1602 			    sctp_endpoint_is_peeled_off(ep, &to)) {
1603 				err = -EADDRNOTAVAIL;
1604 				goto out_unlock;
1605 			}
1606 		}
1607 	} else {
1608 		asoc = sctp_id2assoc(sk, associd);
1609 		if (!asoc) {
1610 			err = -EPIPE;
1611 			goto out_unlock;
1612 		}
1613 	}
1614 
1615 	if (asoc) {
1616 		SCTP_DEBUG_PRINTK("Just looked up association: %p.\n", asoc);
1617 
1618 		/* We cannot send a message on a TCP-style SCTP_SS_ESTABLISHED
1619 		 * socket that has an association in CLOSED state. This can
1620 		 * happen when an accepted socket has an association that is
1621 		 * already CLOSED.
1622 		 */
1623 		if (sctp_state(asoc, CLOSED) && sctp_style(sk, TCP)) {
1624 			err = -EPIPE;
1625 			goto out_unlock;
1626 		}
1627 
1628 		if (sinfo_flags & SCTP_EOF) {
1629 			SCTP_DEBUG_PRINTK("Shutting down association: %p\n",
1630 					  asoc);
1631 			sctp_primitive_SHUTDOWN(asoc, NULL);
1632 			err = 0;
1633 			goto out_unlock;
1634 		}
1635 		if (sinfo_flags & SCTP_ABORT) {
1636 
1637 			chunk = sctp_make_abort_user(asoc, msg, msg_len);
1638 			if (!chunk) {
1639 				err = -ENOMEM;
1640 				goto out_unlock;
1641 			}
1642 
1643 			SCTP_DEBUG_PRINTK("Aborting association: %p\n", asoc);
1644 			sctp_primitive_ABORT(asoc, chunk);
1645 			err = 0;
1646 			goto out_unlock;
1647 		}
1648 	}
1649 
1650 	/* Do we need to create the association?  */
1651 	if (!asoc) {
1652 		SCTP_DEBUG_PRINTK("There is no association yet.\n");
1653 
1654 		if (sinfo_flags & (SCTP_EOF | SCTP_ABORT)) {
1655 			err = -EINVAL;
1656 			goto out_unlock;
1657 		}
1658 
1659 		/* Check for invalid stream against the stream counts,
1660 		 * either the default or the user specified stream counts.
1661 		 */
1662 		if (sinfo) {
1663 			if (!sinit || (sinit && !sinit->sinit_num_ostreams)) {
1664 				/* Check against the defaults. */
1665 				if (sinfo->sinfo_stream >=
1666 				    sp->initmsg.sinit_num_ostreams) {
1667 					err = -EINVAL;
1668 					goto out_unlock;
1669 				}
1670 			} else {
1671 				/* Check against the requested.  */
1672 				if (sinfo->sinfo_stream >=
1673 				    sinit->sinit_num_ostreams) {
1674 					err = -EINVAL;
1675 					goto out_unlock;
1676 				}
1677 			}
1678 		}
1679 
1680 		/*
1681 		 * API 3.1.2 bind() - UDP Style Syntax
1682 		 * If a bind() or sctp_bindx() is not called prior to a
1683 		 * sendmsg() call that initiates a new association, the
1684 		 * system picks an ephemeral port and will choose an address
1685 		 * set equivalent to binding with a wildcard address.
1686 		 */
1687 		if (!ep->base.bind_addr.port) {
1688 			if (sctp_autobind(sk)) {
1689 				err = -EAGAIN;
1690 				goto out_unlock;
1691 			}
1692 		} else {
1693 			/*
1694 			 * If an unprivileged user inherits a one-to-many
1695 			 * style socket with open associations on a privileged
1696 			 * port, it MAY be permitted to accept new associations,
1697 			 * but it SHOULD NOT be permitted to open new
1698 			 * associations.
1699 			 */
1700 			if (ep->base.bind_addr.port < PROT_SOCK &&
1701 			    !capable(CAP_NET_BIND_SERVICE)) {
1702 				err = -EACCES;
1703 				goto out_unlock;
1704 			}
1705 		}
1706 
1707 		scope = sctp_scope(&to);
1708 		new_asoc = sctp_association_new(ep, sk, scope, GFP_KERNEL);
1709 		if (!new_asoc) {
1710 			err = -ENOMEM;
1711 			goto out_unlock;
1712 		}
1713 		asoc = new_asoc;
1714 		err = sctp_assoc_set_bind_addr_from_ep(asoc, scope, GFP_KERNEL);
1715 		if (err < 0) {
1716 			err = -ENOMEM;
1717 			goto out_free;
1718 		}
1719 
1720 		/* If the SCTP_INIT ancillary data is specified, set all
1721 		 * the association init values accordingly.
1722 		 */
1723 		if (sinit) {
1724 			if (sinit->sinit_num_ostreams) {
1725 				asoc->c.sinit_num_ostreams =
1726 					sinit->sinit_num_ostreams;
1727 			}
1728 			if (sinit->sinit_max_instreams) {
1729 				asoc->c.sinit_max_instreams =
1730 					sinit->sinit_max_instreams;
1731 			}
1732 			if (sinit->sinit_max_attempts) {
1733 				asoc->max_init_attempts
1734 					= sinit->sinit_max_attempts;
1735 			}
1736 			if (sinit->sinit_max_init_timeo) {
1737 				asoc->max_init_timeo =
1738 				 msecs_to_jiffies(sinit->sinit_max_init_timeo);
1739 			}
1740 		}
1741 
1742 		/* Prime the peer's transport structures.  */
1743 		transport = sctp_assoc_add_peer(asoc, &to, GFP_KERNEL, SCTP_UNKNOWN);
1744 		if (!transport) {
1745 			err = -ENOMEM;
1746 			goto out_free;
1747 		}
1748 	}
1749 
1750 	/* ASSERT: we have a valid association at this point.  */
1751 	SCTP_DEBUG_PRINTK("We have a valid association.\n");
1752 
1753 	if (!sinfo) {
1754 		/* If the user didn't specify SNDRCVINFO, make up one with
1755 		 * some defaults.
1756 		 */
1757 		default_sinfo.sinfo_stream = asoc->default_stream;
1758 		default_sinfo.sinfo_flags = asoc->default_flags;
1759 		default_sinfo.sinfo_ppid = asoc->default_ppid;
1760 		default_sinfo.sinfo_context = asoc->default_context;
1761 		default_sinfo.sinfo_timetolive = asoc->default_timetolive;
1762 		default_sinfo.sinfo_assoc_id = sctp_assoc2id(asoc);
1763 		sinfo = &default_sinfo;
1764 	}
1765 
1766 	/* API 7.1.7, the sndbuf size per association bounds the
1767 	 * maximum size of data that can be sent in a single send call.
1768 	 */
1769 	if (msg_len > sk->sk_sndbuf) {
1770 		err = -EMSGSIZE;
1771 		goto out_free;
1772 	}
1773 
1774 	if (asoc->pmtu_pending)
1775 		sctp_assoc_pending_pmtu(asoc);
1776 
1777 	/* If fragmentation is disabled and the message length exceeds the
1778 	 * association fragmentation point, return EMSGSIZE.  The I-D
1779 	 * does not specify what this error is, but this looks like
1780 	 * a great fit.
1781 	 */
1782 	if (sctp_sk(sk)->disable_fragments && (msg_len > asoc->frag_point)) {
1783 		err = -EMSGSIZE;
1784 		goto out_free;
1785 	}
1786 
1787 	if (sinfo) {
1788 		/* Check for invalid stream. */
1789 		if (sinfo->sinfo_stream >= asoc->c.sinit_num_ostreams) {
1790 			err = -EINVAL;
1791 			goto out_free;
1792 		}
1793 	}
1794 
1795 	timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
1796 	if (!sctp_wspace(asoc)) {
1797 		err = sctp_wait_for_sndbuf(asoc, &timeo, msg_len);
1798 		if (err)
1799 			goto out_free;
1800 	}
1801 
1802 	/* If an address is passed with the sendto/sendmsg call, it is used
1803 	 * to override the primary destination address in the TCP model, or
1804 	 * when SCTP_ADDR_OVER flag is set in the UDP model.
1805 	 */
1806 	if ((sctp_style(sk, TCP) && msg_name) ||
1807 	    (sinfo_flags & SCTP_ADDR_OVER)) {
1808 		chunk_tp = sctp_assoc_lookup_paddr(asoc, &to);
1809 		if (!chunk_tp) {
1810 			err = -EINVAL;
1811 			goto out_free;
1812 		}
1813 	} else
1814 		chunk_tp = NULL;
1815 
1816 	/* Auto-connect, if we aren't connected already. */
1817 	if (sctp_state(asoc, CLOSED)) {
1818 		err = sctp_primitive_ASSOCIATE(asoc, NULL);
1819 		if (err < 0)
1820 			goto out_free;
1821 		SCTP_DEBUG_PRINTK("We associated primitively.\n");
1822 	}
1823 
1824 	/* Break the message into multiple chunks of maximum size. */
1825 	datamsg = sctp_datamsg_from_user(asoc, sinfo, msg, msg_len);
1826 	if (!datamsg) {
1827 		err = -ENOMEM;
1828 		goto out_free;
1829 	}
1830 
1831 	/* Now send the (possibly) fragmented message. */
1832 	list_for_each_entry(chunk, &datamsg->chunks, frag_list) {
1833 		sctp_chunk_hold(chunk);
1834 
1835 		/* Do accounting for the write space.  */
1836 		sctp_set_owner_w(chunk);
1837 
1838 		chunk->transport = chunk_tp;
1839 	}
1840 
1841 	/* Send it to the lower layers.  Note:  all chunks
1842 	 * must either fail or succeed.   The lower layer
1843 	 * works that way today.  Keep it that way or this
1844 	 * breaks.
1845 	 */
1846 	err = sctp_primitive_SEND(asoc, datamsg);
1847 	/* Did the lower layer accept the chunk? */
1848 	if (err)
1849 		sctp_datamsg_free(datamsg);
1850 	else
1851 		sctp_datamsg_put(datamsg);
1852 
1853 	SCTP_DEBUG_PRINTK("We sent primitively.\n");
1854 
1855 	if (err)
1856 		goto out_free;
1857 	else
1858 		err = msg_len;
1859 
1860 	/* If we are already past ASSOCIATE, the lower
1861 	 * layers are responsible for association cleanup.
1862 	 */
1863 	goto out_unlock;
1864 
1865 out_free:
1866 	if (new_asoc)
1867 		sctp_association_free(asoc);
1868 out_unlock:
1869 	sctp_release_sock(sk);
1870 
1871 out_nounlock:
1872 	return sctp_error(sk, msg_flags, err);
1873 
1874 #if 0
1875 do_sock_err:
1876 	if (msg_len)
1877 		err = msg_len;
1878 	else
1879 		err = sock_error(sk);
1880 	goto out;
1881 
1882 do_interrupted:
1883 	if (msg_len)
1884 		err = msg_len;
1885 	goto out;
1886 #endif /* 0 */
1887 }
1888 
1889 /* This is an extended version of skb_pull() that removes the data from the
1890  * start of a skb even when data is spread across the list of skb's in the
1891  * frag_list. len specifies the total amount of data that needs to be removed.
1892  * when 'len' bytes could be removed from the skb, it returns 0.
1893  * If 'len' exceeds the total skb length,  it returns the no. of bytes that
1894  * could not be removed.
1895  */
1896 static int sctp_skb_pull(struct sk_buff *skb, int len)
1897 {
1898 	struct sk_buff *list;
1899 	int skb_len = skb_headlen(skb);
1900 	int rlen;
1901 
1902 	if (len <= skb_len) {
1903 		__skb_pull(skb, len);
1904 		return 0;
1905 	}
1906 	len -= skb_len;
1907 	__skb_pull(skb, skb_len);
1908 
1909 	skb_walk_frags(skb, list) {
1910 		rlen = sctp_skb_pull(list, len);
1911 		skb->len -= (len-rlen);
1912 		skb->data_len -= (len-rlen);
1913 
1914 		if (!rlen)
1915 			return 0;
1916 
1917 		len = rlen;
1918 	}
1919 
1920 	return len;
1921 }
1922 
1923 /* API 3.1.3  recvmsg() - UDP Style Syntax
1924  *
1925  *  ssize_t recvmsg(int socket, struct msghdr *message,
1926  *                    int flags);
1927  *
1928  *  socket  - the socket descriptor of the endpoint.
1929  *  message - pointer to the msghdr structure which contains a single
1930  *            user message and possibly some ancillary data.
1931  *
1932  *            See Section 5 for complete description of the data
1933  *            structures.
1934  *
1935  *  flags   - flags sent or received with the user message, see Section
1936  *            5 for complete description of the flags.
1937  */
1938 static struct sk_buff *sctp_skb_recv_datagram(struct sock *, int, int, int *);
1939 
1940 SCTP_STATIC int sctp_recvmsg(struct kiocb *iocb, struct sock *sk,
1941 			     struct msghdr *msg, size_t len, int noblock,
1942 			     int flags, int *addr_len)
1943 {
1944 	struct sctp_ulpevent *event = NULL;
1945 	struct sctp_sock *sp = sctp_sk(sk);
1946 	struct sk_buff *skb;
1947 	int copied;
1948 	int err = 0;
1949 	int skb_len;
1950 
1951 	SCTP_DEBUG_PRINTK("sctp_recvmsg(%s: %p, %s: %p, %s: %zd, %s: %d, %s: "
1952 			  "0x%x, %s: %p)\n", "sk", sk, "msghdr", msg,
1953 			  "len", len, "knoblauch", noblock,
1954 			  "flags", flags, "addr_len", addr_len);
1955 
1956 	sctp_lock_sock(sk);
1957 
1958 	if (sctp_style(sk, TCP) && !sctp_sstate(sk, ESTABLISHED)) {
1959 		err = -ENOTCONN;
1960 		goto out;
1961 	}
1962 
1963 	skb = sctp_skb_recv_datagram(sk, flags, noblock, &err);
1964 	if (!skb)
1965 		goto out;
1966 
1967 	/* Get the total length of the skb including any skb's in the
1968 	 * frag_list.
1969 	 */
1970 	skb_len = skb->len;
1971 
1972 	copied = skb_len;
1973 	if (copied > len)
1974 		copied = len;
1975 
1976 	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
1977 
1978 	event = sctp_skb2event(skb);
1979 
1980 	if (err)
1981 		goto out_free;
1982 
1983 	sock_recv_ts_and_drops(msg, sk, skb);
1984 	if (sctp_ulpevent_is_notification(event)) {
1985 		msg->msg_flags |= MSG_NOTIFICATION;
1986 		sp->pf->event_msgname(event, msg->msg_name, addr_len);
1987 	} else {
1988 		sp->pf->skb_msgname(skb, msg->msg_name, addr_len);
1989 	}
1990 
1991 	/* Check if we allow SCTP_SNDRCVINFO. */
1992 	if (sp->subscribe.sctp_data_io_event)
1993 		sctp_ulpevent_read_sndrcvinfo(event, msg);
1994 #if 0
1995 	/* FIXME: we should be calling IP/IPv6 layers.  */
1996 	if (sk->sk_protinfo.af_inet.cmsg_flags)
1997 		ip_cmsg_recv(msg, skb);
1998 #endif
1999 
2000 	err = copied;
2001 
2002 	/* If skb's length exceeds the user's buffer, update the skb and
2003 	 * push it back to the receive_queue so that the next call to
2004 	 * recvmsg() will return the remaining data. Don't set MSG_EOR.
2005 	 */
2006 	if (skb_len > copied) {
2007 		msg->msg_flags &= ~MSG_EOR;
2008 		if (flags & MSG_PEEK)
2009 			goto out_free;
2010 		sctp_skb_pull(skb, copied);
2011 		skb_queue_head(&sk->sk_receive_queue, skb);
2012 
2013 		/* When only partial message is copied to the user, increase
2014 		 * rwnd by that amount. If all the data in the skb is read,
2015 		 * rwnd is updated when the event is freed.
2016 		 */
2017 		if (!sctp_ulpevent_is_notification(event))
2018 			sctp_assoc_rwnd_increase(event->asoc, copied);
2019 		goto out;
2020 	} else if ((event->msg_flags & MSG_NOTIFICATION) ||
2021 		   (event->msg_flags & MSG_EOR))
2022 		msg->msg_flags |= MSG_EOR;
2023 	else
2024 		msg->msg_flags &= ~MSG_EOR;
2025 
2026 out_free:
2027 	if (flags & MSG_PEEK) {
2028 		/* Release the skb reference acquired after peeking the skb in
2029 		 * sctp_skb_recv_datagram().
2030 		 */
2031 		kfree_skb(skb);
2032 	} else {
2033 		/* Free the event which includes releasing the reference to
2034 		 * the owner of the skb, freeing the skb and updating the
2035 		 * rwnd.
2036 		 */
2037 		sctp_ulpevent_free(event);
2038 	}
2039 out:
2040 	sctp_release_sock(sk);
2041 	return err;
2042 }
2043 
2044 /* 7.1.12 Enable/Disable message fragmentation (SCTP_DISABLE_FRAGMENTS)
2045  *
2046  * This option is a on/off flag.  If enabled no SCTP message
2047  * fragmentation will be performed.  Instead if a message being sent
2048  * exceeds the current PMTU size, the message will NOT be sent and
2049  * instead a error will be indicated to the user.
2050  */
2051 static int sctp_setsockopt_disable_fragments(struct sock *sk,
2052 					     char __user *optval,
2053 					     unsigned int optlen)
2054 {
2055 	int val;
2056 
2057 	if (optlen < sizeof(int))
2058 		return -EINVAL;
2059 
2060 	if (get_user(val, (int __user *)optval))
2061 		return -EFAULT;
2062 
2063 	sctp_sk(sk)->disable_fragments = (val == 0) ? 0 : 1;
2064 
2065 	return 0;
2066 }
2067 
2068 static int sctp_setsockopt_events(struct sock *sk, char __user *optval,
2069 				  unsigned int optlen)
2070 {
2071 	if (optlen > sizeof(struct sctp_event_subscribe))
2072 		return -EINVAL;
2073 	if (copy_from_user(&sctp_sk(sk)->subscribe, optval, optlen))
2074 		return -EFAULT;
2075 	return 0;
2076 }
2077 
2078 /* 7.1.8 Automatic Close of associations (SCTP_AUTOCLOSE)
2079  *
2080  * This socket option is applicable to the UDP-style socket only.  When
2081  * set it will cause associations that are idle for more than the
2082  * specified number of seconds to automatically close.  An association
2083  * being idle is defined an association that has NOT sent or received
2084  * user data.  The special value of '0' indicates that no automatic
2085  * close of any associations should be performed.  The option expects an
2086  * integer defining the number of seconds of idle time before an
2087  * association is closed.
2088  */
2089 static int sctp_setsockopt_autoclose(struct sock *sk, char __user *optval,
2090 				     unsigned int optlen)
2091 {
2092 	struct sctp_sock *sp = sctp_sk(sk);
2093 
2094 	/* Applicable to UDP-style socket only */
2095 	if (sctp_style(sk, TCP))
2096 		return -EOPNOTSUPP;
2097 	if (optlen != sizeof(int))
2098 		return -EINVAL;
2099 	if (copy_from_user(&sp->autoclose, optval, optlen))
2100 		return -EFAULT;
2101 	/* make sure it won't exceed MAX_SCHEDULE_TIMEOUT */
2102 	sp->autoclose = min_t(long, sp->autoclose, MAX_SCHEDULE_TIMEOUT / HZ);
2103 
2104 	return 0;
2105 }
2106 
2107 /* 7.1.13 Peer Address Parameters (SCTP_PEER_ADDR_PARAMS)
2108  *
2109  * Applications can enable or disable heartbeats for any peer address of
2110  * an association, modify an address's heartbeat interval, force a
2111  * heartbeat to be sent immediately, and adjust the address's maximum
2112  * number of retransmissions sent before an address is considered
2113  * unreachable.  The following structure is used to access and modify an
2114  * address's parameters:
2115  *
2116  *  struct sctp_paddrparams {
2117  *     sctp_assoc_t            spp_assoc_id;
2118  *     struct sockaddr_storage spp_address;
2119  *     uint32_t                spp_hbinterval;
2120  *     uint16_t                spp_pathmaxrxt;
2121  *     uint32_t                spp_pathmtu;
2122  *     uint32_t                spp_sackdelay;
2123  *     uint32_t                spp_flags;
2124  * };
2125  *
2126  *   spp_assoc_id    - (one-to-many style socket) This is filled in the
2127  *                     application, and identifies the association for
2128  *                     this query.
2129  *   spp_address     - This specifies which address is of interest.
2130  *   spp_hbinterval  - This contains the value of the heartbeat interval,
2131  *                     in milliseconds.  If a  value of zero
2132  *                     is present in this field then no changes are to
2133  *                     be made to this parameter.
2134  *   spp_pathmaxrxt  - This contains the maximum number of
2135  *                     retransmissions before this address shall be
2136  *                     considered unreachable. If a  value of zero
2137  *                     is present in this field then no changes are to
2138  *                     be made to this parameter.
2139  *   spp_pathmtu     - When Path MTU discovery is disabled the value
2140  *                     specified here will be the "fixed" path mtu.
2141  *                     Note that if the spp_address field is empty
2142  *                     then all associations on this address will
2143  *                     have this fixed path mtu set upon them.
2144  *
2145  *   spp_sackdelay   - When delayed sack is enabled, this value specifies
2146  *                     the number of milliseconds that sacks will be delayed
2147  *                     for. This value will apply to all addresses of an
2148  *                     association if the spp_address field is empty. Note
2149  *                     also, that if delayed sack is enabled and this
2150  *                     value is set to 0, no change is made to the last
2151  *                     recorded delayed sack timer value.
2152  *
2153  *   spp_flags       - These flags are used to control various features
2154  *                     on an association. The flag field may contain
2155  *                     zero or more of the following options.
2156  *
2157  *                     SPP_HB_ENABLE  - Enable heartbeats on the
2158  *                     specified address. Note that if the address
2159  *                     field is empty all addresses for the association
2160  *                     have heartbeats enabled upon them.
2161  *
2162  *                     SPP_HB_DISABLE - Disable heartbeats on the
2163  *                     speicifed address. Note that if the address
2164  *                     field is empty all addresses for the association
2165  *                     will have their heartbeats disabled. Note also
2166  *                     that SPP_HB_ENABLE and SPP_HB_DISABLE are
2167  *                     mutually exclusive, only one of these two should
2168  *                     be specified. Enabling both fields will have
2169  *                     undetermined results.
2170  *
2171  *                     SPP_HB_DEMAND - Request a user initiated heartbeat
2172  *                     to be made immediately.
2173  *
2174  *                     SPP_HB_TIME_IS_ZERO - Specify's that the time for
2175  *                     heartbeat delayis to be set to the value of 0
2176  *                     milliseconds.
2177  *
2178  *                     SPP_PMTUD_ENABLE - This field will enable PMTU
2179  *                     discovery upon the specified address. Note that
2180  *                     if the address feild is empty then all addresses
2181  *                     on the association are effected.
2182  *
2183  *                     SPP_PMTUD_DISABLE - This field will disable PMTU
2184  *                     discovery upon the specified address. Note that
2185  *                     if the address feild is empty then all addresses
2186  *                     on the association are effected. Not also that
2187  *                     SPP_PMTUD_ENABLE and SPP_PMTUD_DISABLE are mutually
2188  *                     exclusive. Enabling both will have undetermined
2189  *                     results.
2190  *
2191  *                     SPP_SACKDELAY_ENABLE - Setting this flag turns
2192  *                     on delayed sack. The time specified in spp_sackdelay
2193  *                     is used to specify the sack delay for this address. Note
2194  *                     that if spp_address is empty then all addresses will
2195  *                     enable delayed sack and take on the sack delay
2196  *                     value specified in spp_sackdelay.
2197  *                     SPP_SACKDELAY_DISABLE - Setting this flag turns
2198  *                     off delayed sack. If the spp_address field is blank then
2199  *                     delayed sack is disabled for the entire association. Note
2200  *                     also that this field is mutually exclusive to
2201  *                     SPP_SACKDELAY_ENABLE, setting both will have undefined
2202  *                     results.
2203  */
2204 static int sctp_apply_peer_addr_params(struct sctp_paddrparams *params,
2205 				       struct sctp_transport   *trans,
2206 				       struct sctp_association *asoc,
2207 				       struct sctp_sock        *sp,
2208 				       int                      hb_change,
2209 				       int                      pmtud_change,
2210 				       int                      sackdelay_change)
2211 {
2212 	int error;
2213 
2214 	if (params->spp_flags & SPP_HB_DEMAND && trans) {
2215 		error = sctp_primitive_REQUESTHEARTBEAT (trans->asoc, trans);
2216 		if (error)
2217 			return error;
2218 	}
2219 
2220 	/* Note that unless the spp_flag is set to SPP_HB_ENABLE the value of
2221 	 * this field is ignored.  Note also that a value of zero indicates
2222 	 * the current setting should be left unchanged.
2223 	 */
2224 	if (params->spp_flags & SPP_HB_ENABLE) {
2225 
2226 		/* Re-zero the interval if the SPP_HB_TIME_IS_ZERO is
2227 		 * set.  This lets us use 0 value when this flag
2228 		 * is set.
2229 		 */
2230 		if (params->spp_flags & SPP_HB_TIME_IS_ZERO)
2231 			params->spp_hbinterval = 0;
2232 
2233 		if (params->spp_hbinterval ||
2234 		    (params->spp_flags & SPP_HB_TIME_IS_ZERO)) {
2235 			if (trans) {
2236 				trans->hbinterval =
2237 				    msecs_to_jiffies(params->spp_hbinterval);
2238 			} else if (asoc) {
2239 				asoc->hbinterval =
2240 				    msecs_to_jiffies(params->spp_hbinterval);
2241 			} else {
2242 				sp->hbinterval = params->spp_hbinterval;
2243 			}
2244 		}
2245 	}
2246 
2247 	if (hb_change) {
2248 		if (trans) {
2249 			trans->param_flags =
2250 				(trans->param_flags & ~SPP_HB) | hb_change;
2251 		} else if (asoc) {
2252 			asoc->param_flags =
2253 				(asoc->param_flags & ~SPP_HB) | hb_change;
2254 		} else {
2255 			sp->param_flags =
2256 				(sp->param_flags & ~SPP_HB) | hb_change;
2257 		}
2258 	}
2259 
2260 	/* When Path MTU discovery is disabled the value specified here will
2261 	 * be the "fixed" path mtu (i.e. the value of the spp_flags field must
2262 	 * include the flag SPP_PMTUD_DISABLE for this field to have any
2263 	 * effect).
2264 	 */
2265 	if ((params->spp_flags & SPP_PMTUD_DISABLE) && params->spp_pathmtu) {
2266 		if (trans) {
2267 			trans->pathmtu = params->spp_pathmtu;
2268 			sctp_assoc_sync_pmtu(asoc);
2269 		} else if (asoc) {
2270 			asoc->pathmtu = params->spp_pathmtu;
2271 			sctp_frag_point(asoc, params->spp_pathmtu);
2272 		} else {
2273 			sp->pathmtu = params->spp_pathmtu;
2274 		}
2275 	}
2276 
2277 	if (pmtud_change) {
2278 		if (trans) {
2279 			int update = (trans->param_flags & SPP_PMTUD_DISABLE) &&
2280 				(params->spp_flags & SPP_PMTUD_ENABLE);
2281 			trans->param_flags =
2282 				(trans->param_flags & ~SPP_PMTUD) | pmtud_change;
2283 			if (update) {
2284 				sctp_transport_pmtu(trans);
2285 				sctp_assoc_sync_pmtu(asoc);
2286 			}
2287 		} else if (asoc) {
2288 			asoc->param_flags =
2289 				(asoc->param_flags & ~SPP_PMTUD) | pmtud_change;
2290 		} else {
2291 			sp->param_flags =
2292 				(sp->param_flags & ~SPP_PMTUD) | pmtud_change;
2293 		}
2294 	}
2295 
2296 	/* Note that unless the spp_flag is set to SPP_SACKDELAY_ENABLE the
2297 	 * value of this field is ignored.  Note also that a value of zero
2298 	 * indicates the current setting should be left unchanged.
2299 	 */
2300 	if ((params->spp_flags & SPP_SACKDELAY_ENABLE) && params->spp_sackdelay) {
2301 		if (trans) {
2302 			trans->sackdelay =
2303 				msecs_to_jiffies(params->spp_sackdelay);
2304 		} else if (asoc) {
2305 			asoc->sackdelay =
2306 				msecs_to_jiffies(params->spp_sackdelay);
2307 		} else {
2308 			sp->sackdelay = params->spp_sackdelay;
2309 		}
2310 	}
2311 
2312 	if (sackdelay_change) {
2313 		if (trans) {
2314 			trans->param_flags =
2315 				(trans->param_flags & ~SPP_SACKDELAY) |
2316 				sackdelay_change;
2317 		} else if (asoc) {
2318 			asoc->param_flags =
2319 				(asoc->param_flags & ~SPP_SACKDELAY) |
2320 				sackdelay_change;
2321 		} else {
2322 			sp->param_flags =
2323 				(sp->param_flags & ~SPP_SACKDELAY) |
2324 				sackdelay_change;
2325 		}
2326 	}
2327 
2328 	/* Note that a value of zero indicates the current setting should be
2329 	   left unchanged.
2330 	 */
2331 	if (params->spp_pathmaxrxt) {
2332 		if (trans) {
2333 			trans->pathmaxrxt = params->spp_pathmaxrxt;
2334 		} else if (asoc) {
2335 			asoc->pathmaxrxt = params->spp_pathmaxrxt;
2336 		} else {
2337 			sp->pathmaxrxt = params->spp_pathmaxrxt;
2338 		}
2339 	}
2340 
2341 	return 0;
2342 }
2343 
2344 static int sctp_setsockopt_peer_addr_params(struct sock *sk,
2345 					    char __user *optval,
2346 					    unsigned int optlen)
2347 {
2348 	struct sctp_paddrparams  params;
2349 	struct sctp_transport   *trans = NULL;
2350 	struct sctp_association *asoc = NULL;
2351 	struct sctp_sock        *sp = sctp_sk(sk);
2352 	int error;
2353 	int hb_change, pmtud_change, sackdelay_change;
2354 
2355 	if (optlen != sizeof(struct sctp_paddrparams))
2356 		return - EINVAL;
2357 
2358 	if (copy_from_user(&params, optval, optlen))
2359 		return -EFAULT;
2360 
2361 	/* Validate flags and value parameters. */
2362 	hb_change        = params.spp_flags & SPP_HB;
2363 	pmtud_change     = params.spp_flags & SPP_PMTUD;
2364 	sackdelay_change = params.spp_flags & SPP_SACKDELAY;
2365 
2366 	if (hb_change        == SPP_HB ||
2367 	    pmtud_change     == SPP_PMTUD ||
2368 	    sackdelay_change == SPP_SACKDELAY ||
2369 	    params.spp_sackdelay > 500 ||
2370 	    (params.spp_pathmtu &&
2371 	     params.spp_pathmtu < SCTP_DEFAULT_MINSEGMENT))
2372 		return -EINVAL;
2373 
2374 	/* If an address other than INADDR_ANY is specified, and
2375 	 * no transport is found, then the request is invalid.
2376 	 */
2377 	if (!sctp_is_any(sk, ( union sctp_addr *)&params.spp_address)) {
2378 		trans = sctp_addr_id2transport(sk, &params.spp_address,
2379 					       params.spp_assoc_id);
2380 		if (!trans)
2381 			return -EINVAL;
2382 	}
2383 
2384 	/* Get association, if assoc_id != 0 and the socket is a one
2385 	 * to many style socket, and an association was not found, then
2386 	 * the id was invalid.
2387 	 */
2388 	asoc = sctp_id2assoc(sk, params.spp_assoc_id);
2389 	if (!asoc && params.spp_assoc_id && sctp_style(sk, UDP))
2390 		return -EINVAL;
2391 
2392 	/* Heartbeat demand can only be sent on a transport or
2393 	 * association, but not a socket.
2394 	 */
2395 	if (params.spp_flags & SPP_HB_DEMAND && !trans && !asoc)
2396 		return -EINVAL;
2397 
2398 	/* Process parameters. */
2399 	error = sctp_apply_peer_addr_params(&params, trans, asoc, sp,
2400 					    hb_change, pmtud_change,
2401 					    sackdelay_change);
2402 
2403 	if (error)
2404 		return error;
2405 
2406 	/* If changes are for association, also apply parameters to each
2407 	 * transport.
2408 	 */
2409 	if (!trans && asoc) {
2410 		list_for_each_entry(trans, &asoc->peer.transport_addr_list,
2411 				transports) {
2412 			sctp_apply_peer_addr_params(&params, trans, asoc, sp,
2413 						    hb_change, pmtud_change,
2414 						    sackdelay_change);
2415 		}
2416 	}
2417 
2418 	return 0;
2419 }
2420 
2421 /*
2422  * 7.1.23.  Get or set delayed ack timer (SCTP_DELAYED_SACK)
2423  *
2424  * This option will effect the way delayed acks are performed.  This
2425  * option allows you to get or set the delayed ack time, in
2426  * milliseconds.  It also allows changing the delayed ack frequency.
2427  * Changing the frequency to 1 disables the delayed sack algorithm.  If
2428  * the assoc_id is 0, then this sets or gets the endpoints default
2429  * values.  If the assoc_id field is non-zero, then the set or get
2430  * effects the specified association for the one to many model (the
2431  * assoc_id field is ignored by the one to one model).  Note that if
2432  * sack_delay or sack_freq are 0 when setting this option, then the
2433  * current values will remain unchanged.
2434  *
2435  * struct sctp_sack_info {
2436  *     sctp_assoc_t            sack_assoc_id;
2437  *     uint32_t                sack_delay;
2438  *     uint32_t                sack_freq;
2439  * };
2440  *
2441  * sack_assoc_id -  This parameter, indicates which association the user
2442  *    is performing an action upon.  Note that if this field's value is
2443  *    zero then the endpoints default value is changed (effecting future
2444  *    associations only).
2445  *
2446  * sack_delay -  This parameter contains the number of milliseconds that
2447  *    the user is requesting the delayed ACK timer be set to.  Note that
2448  *    this value is defined in the standard to be between 200 and 500
2449  *    milliseconds.
2450  *
2451  * sack_freq -  This parameter contains the number of packets that must
2452  *    be received before a sack is sent without waiting for the delay
2453  *    timer to expire.  The default value for this is 2, setting this
2454  *    value to 1 will disable the delayed sack algorithm.
2455  */
2456 
2457 static int sctp_setsockopt_delayed_ack(struct sock *sk,
2458 				       char __user *optval, unsigned int optlen)
2459 {
2460 	struct sctp_sack_info    params;
2461 	struct sctp_transport   *trans = NULL;
2462 	struct sctp_association *asoc = NULL;
2463 	struct sctp_sock        *sp = sctp_sk(sk);
2464 
2465 	if (optlen == sizeof(struct sctp_sack_info)) {
2466 		if (copy_from_user(&params, optval, optlen))
2467 			return -EFAULT;
2468 
2469 		if (params.sack_delay == 0 && params.sack_freq == 0)
2470 			return 0;
2471 	} else if (optlen == sizeof(struct sctp_assoc_value)) {
2472 		printk(KERN_WARNING "SCTP: Use of struct sctp_assoc_value "
2473 		       "in delayed_ack socket option deprecated\n");
2474 		printk(KERN_WARNING "SCTP: Use struct sctp_sack_info instead\n");
2475 		if (copy_from_user(&params, optval, optlen))
2476 			return -EFAULT;
2477 
2478 		if (params.sack_delay == 0)
2479 			params.sack_freq = 1;
2480 		else
2481 			params.sack_freq = 0;
2482 	} else
2483 		return - EINVAL;
2484 
2485 	/* Validate value parameter. */
2486 	if (params.sack_delay > 500)
2487 		return -EINVAL;
2488 
2489 	/* Get association, if sack_assoc_id != 0 and the socket is a one
2490 	 * to many style socket, and an association was not found, then
2491 	 * the id was invalid.
2492 	 */
2493 	asoc = sctp_id2assoc(sk, params.sack_assoc_id);
2494 	if (!asoc && params.sack_assoc_id && sctp_style(sk, UDP))
2495 		return -EINVAL;
2496 
2497 	if (params.sack_delay) {
2498 		if (asoc) {
2499 			asoc->sackdelay =
2500 				msecs_to_jiffies(params.sack_delay);
2501 			asoc->param_flags =
2502 				(asoc->param_flags & ~SPP_SACKDELAY) |
2503 				SPP_SACKDELAY_ENABLE;
2504 		} else {
2505 			sp->sackdelay = params.sack_delay;
2506 			sp->param_flags =
2507 				(sp->param_flags & ~SPP_SACKDELAY) |
2508 				SPP_SACKDELAY_ENABLE;
2509 		}
2510 	}
2511 
2512 	if (params.sack_freq == 1) {
2513 		if (asoc) {
2514 			asoc->param_flags =
2515 				(asoc->param_flags & ~SPP_SACKDELAY) |
2516 				SPP_SACKDELAY_DISABLE;
2517 		} else {
2518 			sp->param_flags =
2519 				(sp->param_flags & ~SPP_SACKDELAY) |
2520 				SPP_SACKDELAY_DISABLE;
2521 		}
2522 	} else if (params.sack_freq > 1) {
2523 		if (asoc) {
2524 			asoc->sackfreq = params.sack_freq;
2525 			asoc->param_flags =
2526 				(asoc->param_flags & ~SPP_SACKDELAY) |
2527 				SPP_SACKDELAY_ENABLE;
2528 		} else {
2529 			sp->sackfreq = params.sack_freq;
2530 			sp->param_flags =
2531 				(sp->param_flags & ~SPP_SACKDELAY) |
2532 				SPP_SACKDELAY_ENABLE;
2533 		}
2534 	}
2535 
2536 	/* If change is for association, also apply to each transport. */
2537 	if (asoc) {
2538 		list_for_each_entry(trans, &asoc->peer.transport_addr_list,
2539 				transports) {
2540 			if (params.sack_delay) {
2541 				trans->sackdelay =
2542 					msecs_to_jiffies(params.sack_delay);
2543 				trans->param_flags =
2544 					(trans->param_flags & ~SPP_SACKDELAY) |
2545 					SPP_SACKDELAY_ENABLE;
2546 			}
2547 			if (params.sack_freq == 1) {
2548 				trans->param_flags =
2549 					(trans->param_flags & ~SPP_SACKDELAY) |
2550 					SPP_SACKDELAY_DISABLE;
2551 			} else if (params.sack_freq > 1) {
2552 				trans->sackfreq = params.sack_freq;
2553 				trans->param_flags =
2554 					(trans->param_flags & ~SPP_SACKDELAY) |
2555 					SPP_SACKDELAY_ENABLE;
2556 			}
2557 		}
2558 	}
2559 
2560 	return 0;
2561 }
2562 
2563 /* 7.1.3 Initialization Parameters (SCTP_INITMSG)
2564  *
2565  * Applications can specify protocol parameters for the default association
2566  * initialization.  The option name argument to setsockopt() and getsockopt()
2567  * is SCTP_INITMSG.
2568  *
2569  * Setting initialization parameters is effective only on an unconnected
2570  * socket (for UDP-style sockets only future associations are effected
2571  * by the change).  With TCP-style sockets, this option is inherited by
2572  * sockets derived from a listener socket.
2573  */
2574 static int sctp_setsockopt_initmsg(struct sock *sk, char __user *optval, unsigned int optlen)
2575 {
2576 	struct sctp_initmsg sinit;
2577 	struct sctp_sock *sp = sctp_sk(sk);
2578 
2579 	if (optlen != sizeof(struct sctp_initmsg))
2580 		return -EINVAL;
2581 	if (copy_from_user(&sinit, optval, optlen))
2582 		return -EFAULT;
2583 
2584 	if (sinit.sinit_num_ostreams)
2585 		sp->initmsg.sinit_num_ostreams = sinit.sinit_num_ostreams;
2586 	if (sinit.sinit_max_instreams)
2587 		sp->initmsg.sinit_max_instreams = sinit.sinit_max_instreams;
2588 	if (sinit.sinit_max_attempts)
2589 		sp->initmsg.sinit_max_attempts = sinit.sinit_max_attempts;
2590 	if (sinit.sinit_max_init_timeo)
2591 		sp->initmsg.sinit_max_init_timeo = sinit.sinit_max_init_timeo;
2592 
2593 	return 0;
2594 }
2595 
2596 /*
2597  * 7.1.14 Set default send parameters (SCTP_DEFAULT_SEND_PARAM)
2598  *
2599  *   Applications that wish to use the sendto() system call may wish to
2600  *   specify a default set of parameters that would normally be supplied
2601  *   through the inclusion of ancillary data.  This socket option allows
2602  *   such an application to set the default sctp_sndrcvinfo structure.
2603  *   The application that wishes to use this socket option simply passes
2604  *   in to this call the sctp_sndrcvinfo structure defined in Section
2605  *   5.2.2) The input parameters accepted by this call include
2606  *   sinfo_stream, sinfo_flags, sinfo_ppid, sinfo_context,
2607  *   sinfo_timetolive.  The user must provide the sinfo_assoc_id field in
2608  *   to this call if the caller is using the UDP model.
2609  */
2610 static int sctp_setsockopt_default_send_param(struct sock *sk,
2611 					      char __user *optval,
2612 					      unsigned int optlen)
2613 {
2614 	struct sctp_sndrcvinfo info;
2615 	struct sctp_association *asoc;
2616 	struct sctp_sock *sp = sctp_sk(sk);
2617 
2618 	if (optlen != sizeof(struct sctp_sndrcvinfo))
2619 		return -EINVAL;
2620 	if (copy_from_user(&info, optval, optlen))
2621 		return -EFAULT;
2622 
2623 	asoc = sctp_id2assoc(sk, info.sinfo_assoc_id);
2624 	if (!asoc && info.sinfo_assoc_id && sctp_style(sk, UDP))
2625 		return -EINVAL;
2626 
2627 	if (asoc) {
2628 		asoc->default_stream = info.sinfo_stream;
2629 		asoc->default_flags = info.sinfo_flags;
2630 		asoc->default_ppid = info.sinfo_ppid;
2631 		asoc->default_context = info.sinfo_context;
2632 		asoc->default_timetolive = info.sinfo_timetolive;
2633 	} else {
2634 		sp->default_stream = info.sinfo_stream;
2635 		sp->default_flags = info.sinfo_flags;
2636 		sp->default_ppid = info.sinfo_ppid;
2637 		sp->default_context = info.sinfo_context;
2638 		sp->default_timetolive = info.sinfo_timetolive;
2639 	}
2640 
2641 	return 0;
2642 }
2643 
2644 /* 7.1.10 Set Primary Address (SCTP_PRIMARY_ADDR)
2645  *
2646  * Requests that the local SCTP stack use the enclosed peer address as
2647  * the association primary.  The enclosed address must be one of the
2648  * association peer's addresses.
2649  */
2650 static int sctp_setsockopt_primary_addr(struct sock *sk, char __user *optval,
2651 					unsigned int optlen)
2652 {
2653 	struct sctp_prim prim;
2654 	struct sctp_transport *trans;
2655 
2656 	if (optlen != sizeof(struct sctp_prim))
2657 		return -EINVAL;
2658 
2659 	if (copy_from_user(&prim, optval, sizeof(struct sctp_prim)))
2660 		return -EFAULT;
2661 
2662 	trans = sctp_addr_id2transport(sk, &prim.ssp_addr, prim.ssp_assoc_id);
2663 	if (!trans)
2664 		return -EINVAL;
2665 
2666 	sctp_assoc_set_primary(trans->asoc, trans);
2667 
2668 	return 0;
2669 }
2670 
2671 /*
2672  * 7.1.5 SCTP_NODELAY
2673  *
2674  * Turn on/off any Nagle-like algorithm.  This means that packets are
2675  * generally sent as soon as possible and no unnecessary delays are
2676  * introduced, at the cost of more packets in the network.  Expects an
2677  *  integer boolean flag.
2678  */
2679 static int sctp_setsockopt_nodelay(struct sock *sk, char __user *optval,
2680 				   unsigned int optlen)
2681 {
2682 	int val;
2683 
2684 	if (optlen < sizeof(int))
2685 		return -EINVAL;
2686 	if (get_user(val, (int __user *)optval))
2687 		return -EFAULT;
2688 
2689 	sctp_sk(sk)->nodelay = (val == 0) ? 0 : 1;
2690 	return 0;
2691 }
2692 
2693 /*
2694  *
2695  * 7.1.1 SCTP_RTOINFO
2696  *
2697  * The protocol parameters used to initialize and bound retransmission
2698  * timeout (RTO) are tunable. sctp_rtoinfo structure is used to access
2699  * and modify these parameters.
2700  * All parameters are time values, in milliseconds.  A value of 0, when
2701  * modifying the parameters, indicates that the current value should not
2702  * be changed.
2703  *
2704  */
2705 static int sctp_setsockopt_rtoinfo(struct sock *sk, char __user *optval, unsigned int optlen)
2706 {
2707 	struct sctp_rtoinfo rtoinfo;
2708 	struct sctp_association *asoc;
2709 
2710 	if (optlen != sizeof (struct sctp_rtoinfo))
2711 		return -EINVAL;
2712 
2713 	if (copy_from_user(&rtoinfo, optval, optlen))
2714 		return -EFAULT;
2715 
2716 	asoc = sctp_id2assoc(sk, rtoinfo.srto_assoc_id);
2717 
2718 	/* Set the values to the specific association */
2719 	if (!asoc && rtoinfo.srto_assoc_id && sctp_style(sk, UDP))
2720 		return -EINVAL;
2721 
2722 	if (asoc) {
2723 		if (rtoinfo.srto_initial != 0)
2724 			asoc->rto_initial =
2725 				msecs_to_jiffies(rtoinfo.srto_initial);
2726 		if (rtoinfo.srto_max != 0)
2727 			asoc->rto_max = msecs_to_jiffies(rtoinfo.srto_max);
2728 		if (rtoinfo.srto_min != 0)
2729 			asoc->rto_min = msecs_to_jiffies(rtoinfo.srto_min);
2730 	} else {
2731 		/* If there is no association or the association-id = 0
2732 		 * set the values to the endpoint.
2733 		 */
2734 		struct sctp_sock *sp = sctp_sk(sk);
2735 
2736 		if (rtoinfo.srto_initial != 0)
2737 			sp->rtoinfo.srto_initial = rtoinfo.srto_initial;
2738 		if (rtoinfo.srto_max != 0)
2739 			sp->rtoinfo.srto_max = rtoinfo.srto_max;
2740 		if (rtoinfo.srto_min != 0)
2741 			sp->rtoinfo.srto_min = rtoinfo.srto_min;
2742 	}
2743 
2744 	return 0;
2745 }
2746 
2747 /*
2748  *
2749  * 7.1.2 SCTP_ASSOCINFO
2750  *
2751  * This option is used to tune the maximum retransmission attempts
2752  * of the association.
2753  * Returns an error if the new association retransmission value is
2754  * greater than the sum of the retransmission value  of the peer.
2755  * See [SCTP] for more information.
2756  *
2757  */
2758 static int sctp_setsockopt_associnfo(struct sock *sk, char __user *optval, unsigned int optlen)
2759 {
2760 
2761 	struct sctp_assocparams assocparams;
2762 	struct sctp_association *asoc;
2763 
2764 	if (optlen != sizeof(struct sctp_assocparams))
2765 		return -EINVAL;
2766 	if (copy_from_user(&assocparams, optval, optlen))
2767 		return -EFAULT;
2768 
2769 	asoc = sctp_id2assoc(sk, assocparams.sasoc_assoc_id);
2770 
2771 	if (!asoc && assocparams.sasoc_assoc_id && sctp_style(sk, UDP))
2772 		return -EINVAL;
2773 
2774 	/* Set the values to the specific association */
2775 	if (asoc) {
2776 		if (assocparams.sasoc_asocmaxrxt != 0) {
2777 			__u32 path_sum = 0;
2778 			int   paths = 0;
2779 			struct sctp_transport *peer_addr;
2780 
2781 			list_for_each_entry(peer_addr, &asoc->peer.transport_addr_list,
2782 					transports) {
2783 				path_sum += peer_addr->pathmaxrxt;
2784 				paths++;
2785 			}
2786 
2787 			/* Only validate asocmaxrxt if we have more than
2788 			 * one path/transport.  We do this because path
2789 			 * retransmissions are only counted when we have more
2790 			 * then one path.
2791 			 */
2792 			if (paths > 1 &&
2793 			    assocparams.sasoc_asocmaxrxt > path_sum)
2794 				return -EINVAL;
2795 
2796 			asoc->max_retrans = assocparams.sasoc_asocmaxrxt;
2797 		}
2798 
2799 		if (assocparams.sasoc_cookie_life != 0) {
2800 			asoc->cookie_life.tv_sec =
2801 					assocparams.sasoc_cookie_life / 1000;
2802 			asoc->cookie_life.tv_usec =
2803 					(assocparams.sasoc_cookie_life % 1000)
2804 					* 1000;
2805 		}
2806 	} else {
2807 		/* Set the values to the endpoint */
2808 		struct sctp_sock *sp = sctp_sk(sk);
2809 
2810 		if (assocparams.sasoc_asocmaxrxt != 0)
2811 			sp->assocparams.sasoc_asocmaxrxt =
2812 						assocparams.sasoc_asocmaxrxt;
2813 		if (assocparams.sasoc_cookie_life != 0)
2814 			sp->assocparams.sasoc_cookie_life =
2815 						assocparams.sasoc_cookie_life;
2816 	}
2817 	return 0;
2818 }
2819 
2820 /*
2821  * 7.1.16 Set/clear IPv4 mapped addresses (SCTP_I_WANT_MAPPED_V4_ADDR)
2822  *
2823  * This socket option is a boolean flag which turns on or off mapped V4
2824  * addresses.  If this option is turned on and the socket is type
2825  * PF_INET6, then IPv4 addresses will be mapped to V6 representation.
2826  * If this option is turned off, then no mapping will be done of V4
2827  * addresses and a user will receive both PF_INET6 and PF_INET type
2828  * addresses on the socket.
2829  */
2830 static int sctp_setsockopt_mappedv4(struct sock *sk, char __user *optval, unsigned int optlen)
2831 {
2832 	int val;
2833 	struct sctp_sock *sp = sctp_sk(sk);
2834 
2835 	if (optlen < sizeof(int))
2836 		return -EINVAL;
2837 	if (get_user(val, (int __user *)optval))
2838 		return -EFAULT;
2839 	if (val)
2840 		sp->v4mapped = 1;
2841 	else
2842 		sp->v4mapped = 0;
2843 
2844 	return 0;
2845 }
2846 
2847 /*
2848  * 8.1.16.  Get or Set the Maximum Fragmentation Size (SCTP_MAXSEG)
2849  * This option will get or set the maximum size to put in any outgoing
2850  * SCTP DATA chunk.  If a message is larger than this size it will be
2851  * fragmented by SCTP into the specified size.  Note that the underlying
2852  * SCTP implementation may fragment into smaller sized chunks when the
2853  * PMTU of the underlying association is smaller than the value set by
2854  * the user.  The default value for this option is '0' which indicates
2855  * the user is NOT limiting fragmentation and only the PMTU will effect
2856  * SCTP's choice of DATA chunk size.  Note also that values set larger
2857  * than the maximum size of an IP datagram will effectively let SCTP
2858  * control fragmentation (i.e. the same as setting this option to 0).
2859  *
2860  * The following structure is used to access and modify this parameter:
2861  *
2862  * struct sctp_assoc_value {
2863  *   sctp_assoc_t assoc_id;
2864  *   uint32_t assoc_value;
2865  * };
2866  *
2867  * assoc_id:  This parameter is ignored for one-to-one style sockets.
2868  *    For one-to-many style sockets this parameter indicates which
2869  *    association the user is performing an action upon.  Note that if
2870  *    this field's value is zero then the endpoints default value is
2871  *    changed (effecting future associations only).
2872  * assoc_value:  This parameter specifies the maximum size in bytes.
2873  */
2874 static int sctp_setsockopt_maxseg(struct sock *sk, char __user *optval, unsigned int optlen)
2875 {
2876 	struct sctp_assoc_value params;
2877 	struct sctp_association *asoc;
2878 	struct sctp_sock *sp = sctp_sk(sk);
2879 	int val;
2880 
2881 	if (optlen == sizeof(int)) {
2882 		printk(KERN_WARNING
2883 		   "SCTP: Use of int in maxseg socket option deprecated\n");
2884 		printk(KERN_WARNING
2885 		   "SCTP: Use struct sctp_assoc_value instead\n");
2886 		if (copy_from_user(&val, optval, optlen))
2887 			return -EFAULT;
2888 		params.assoc_id = 0;
2889 	} else if (optlen == sizeof(struct sctp_assoc_value)) {
2890 		if (copy_from_user(&params, optval, optlen))
2891 			return -EFAULT;
2892 		val = params.assoc_value;
2893 	} else
2894 		return -EINVAL;
2895 
2896 	if ((val != 0) && ((val < 8) || (val > SCTP_MAX_CHUNK_LEN)))
2897 		return -EINVAL;
2898 
2899 	asoc = sctp_id2assoc(sk, params.assoc_id);
2900 	if (!asoc && params.assoc_id && sctp_style(sk, UDP))
2901 		return -EINVAL;
2902 
2903 	if (asoc) {
2904 		if (val == 0) {
2905 			val = asoc->pathmtu;
2906 			val -= sp->pf->af->net_header_len;
2907 			val -= sizeof(struct sctphdr) +
2908 					sizeof(struct sctp_data_chunk);
2909 		}
2910 		asoc->user_frag = val;
2911 		asoc->frag_point = sctp_frag_point(asoc, asoc->pathmtu);
2912 	} else {
2913 		sp->user_frag = val;
2914 	}
2915 
2916 	return 0;
2917 }
2918 
2919 
2920 /*
2921  *  7.1.9 Set Peer Primary Address (SCTP_SET_PEER_PRIMARY_ADDR)
2922  *
2923  *   Requests that the peer mark the enclosed address as the association
2924  *   primary. The enclosed address must be one of the association's
2925  *   locally bound addresses. The following structure is used to make a
2926  *   set primary request:
2927  */
2928 static int sctp_setsockopt_peer_primary_addr(struct sock *sk, char __user *optval,
2929 					     unsigned int optlen)
2930 {
2931 	struct sctp_sock	*sp;
2932 	struct sctp_endpoint	*ep;
2933 	struct sctp_association	*asoc = NULL;
2934 	struct sctp_setpeerprim	prim;
2935 	struct sctp_chunk	*chunk;
2936 	int 			err;
2937 
2938 	sp = sctp_sk(sk);
2939 	ep = sp->ep;
2940 
2941 	if (!sctp_addip_enable)
2942 		return -EPERM;
2943 
2944 	if (optlen != sizeof(struct sctp_setpeerprim))
2945 		return -EINVAL;
2946 
2947 	if (copy_from_user(&prim, optval, optlen))
2948 		return -EFAULT;
2949 
2950 	asoc = sctp_id2assoc(sk, prim.sspp_assoc_id);
2951 	if (!asoc)
2952 		return -EINVAL;
2953 
2954 	if (!asoc->peer.asconf_capable)
2955 		return -EPERM;
2956 
2957 	if (asoc->peer.addip_disabled_mask & SCTP_PARAM_SET_PRIMARY)
2958 		return -EPERM;
2959 
2960 	if (!sctp_state(asoc, ESTABLISHED))
2961 		return -ENOTCONN;
2962 
2963 	if (!sctp_assoc_lookup_laddr(asoc, (union sctp_addr *)&prim.sspp_addr))
2964 		return -EADDRNOTAVAIL;
2965 
2966 	/* Create an ASCONF chunk with SET_PRIMARY parameter	*/
2967 	chunk = sctp_make_asconf_set_prim(asoc,
2968 					  (union sctp_addr *)&prim.sspp_addr);
2969 	if (!chunk)
2970 		return -ENOMEM;
2971 
2972 	err = sctp_send_asconf(asoc, chunk);
2973 
2974 	SCTP_DEBUG_PRINTK("We set peer primary addr primitively.\n");
2975 
2976 	return err;
2977 }
2978 
2979 static int sctp_setsockopt_adaptation_layer(struct sock *sk, char __user *optval,
2980 					    unsigned int optlen)
2981 {
2982 	struct sctp_setadaptation adaptation;
2983 
2984 	if (optlen != sizeof(struct sctp_setadaptation))
2985 		return -EINVAL;
2986 	if (copy_from_user(&adaptation, optval, optlen))
2987 		return -EFAULT;
2988 
2989 	sctp_sk(sk)->adaptation_ind = adaptation.ssb_adaptation_ind;
2990 
2991 	return 0;
2992 }
2993 
2994 /*
2995  * 7.1.29.  Set or Get the default context (SCTP_CONTEXT)
2996  *
2997  * The context field in the sctp_sndrcvinfo structure is normally only
2998  * used when a failed message is retrieved holding the value that was
2999  * sent down on the actual send call.  This option allows the setting of
3000  * a default context on an association basis that will be received on
3001  * reading messages from the peer.  This is especially helpful in the
3002  * one-2-many model for an application to keep some reference to an
3003  * internal state machine that is processing messages on the
3004  * association.  Note that the setting of this value only effects
3005  * received messages from the peer and does not effect the value that is
3006  * saved with outbound messages.
3007  */
3008 static int sctp_setsockopt_context(struct sock *sk, char __user *optval,
3009 				   unsigned int optlen)
3010 {
3011 	struct sctp_assoc_value params;
3012 	struct sctp_sock *sp;
3013 	struct sctp_association *asoc;
3014 
3015 	if (optlen != sizeof(struct sctp_assoc_value))
3016 		return -EINVAL;
3017 	if (copy_from_user(&params, optval, optlen))
3018 		return -EFAULT;
3019 
3020 	sp = sctp_sk(sk);
3021 
3022 	if (params.assoc_id != 0) {
3023 		asoc = sctp_id2assoc(sk, params.assoc_id);
3024 		if (!asoc)
3025 			return -EINVAL;
3026 		asoc->default_rcv_context = params.assoc_value;
3027 	} else {
3028 		sp->default_rcv_context = params.assoc_value;
3029 	}
3030 
3031 	return 0;
3032 }
3033 
3034 /*
3035  * 7.1.24.  Get or set fragmented interleave (SCTP_FRAGMENT_INTERLEAVE)
3036  *
3037  * This options will at a minimum specify if the implementation is doing
3038  * fragmented interleave.  Fragmented interleave, for a one to many
3039  * socket, is when subsequent calls to receive a message may return
3040  * parts of messages from different associations.  Some implementations
3041  * may allow you to turn this value on or off.  If so, when turned off,
3042  * no fragment interleave will occur (which will cause a head of line
3043  * blocking amongst multiple associations sharing the same one to many
3044  * socket).  When this option is turned on, then each receive call may
3045  * come from a different association (thus the user must receive data
3046  * with the extended calls (e.g. sctp_recvmsg) to keep track of which
3047  * association each receive belongs to.
3048  *
3049  * This option takes a boolean value.  A non-zero value indicates that
3050  * fragmented interleave is on.  A value of zero indicates that
3051  * fragmented interleave is off.
3052  *
3053  * Note that it is important that an implementation that allows this
3054  * option to be turned on, have it off by default.  Otherwise an unaware
3055  * application using the one to many model may become confused and act
3056  * incorrectly.
3057  */
3058 static int sctp_setsockopt_fragment_interleave(struct sock *sk,
3059 					       char __user *optval,
3060 					       unsigned int optlen)
3061 {
3062 	int val;
3063 
3064 	if (optlen != sizeof(int))
3065 		return -EINVAL;
3066 	if (get_user(val, (int __user *)optval))
3067 		return -EFAULT;
3068 
3069 	sctp_sk(sk)->frag_interleave = (val == 0) ? 0 : 1;
3070 
3071 	return 0;
3072 }
3073 
3074 /*
3075  * 8.1.21.  Set or Get the SCTP Partial Delivery Point
3076  *       (SCTP_PARTIAL_DELIVERY_POINT)
3077  *
3078  * This option will set or get the SCTP partial delivery point.  This
3079  * point is the size of a message where the partial delivery API will be
3080  * invoked to help free up rwnd space for the peer.  Setting this to a
3081  * lower value will cause partial deliveries to happen more often.  The
3082  * calls argument is an integer that sets or gets the partial delivery
3083  * point.  Note also that the call will fail if the user attempts to set
3084  * this value larger than the socket receive buffer size.
3085  *
3086  * Note that any single message having a length smaller than or equal to
3087  * the SCTP partial delivery point will be delivered in one single read
3088  * call as long as the user provided buffer is large enough to hold the
3089  * message.
3090  */
3091 static int sctp_setsockopt_partial_delivery_point(struct sock *sk,
3092 						  char __user *optval,
3093 						  unsigned int optlen)
3094 {
3095 	u32 val;
3096 
3097 	if (optlen != sizeof(u32))
3098 		return -EINVAL;
3099 	if (get_user(val, (int __user *)optval))
3100 		return -EFAULT;
3101 
3102 	/* Note: We double the receive buffer from what the user sets
3103 	 * it to be, also initial rwnd is based on rcvbuf/2.
3104 	 */
3105 	if (val > (sk->sk_rcvbuf >> 1))
3106 		return -EINVAL;
3107 
3108 	sctp_sk(sk)->pd_point = val;
3109 
3110 	return 0; /* is this the right error code? */
3111 }
3112 
3113 /*
3114  * 7.1.28.  Set or Get the maximum burst (SCTP_MAX_BURST)
3115  *
3116  * This option will allow a user to change the maximum burst of packets
3117  * that can be emitted by this association.  Note that the default value
3118  * is 4, and some implementations may restrict this setting so that it
3119  * can only be lowered.
3120  *
3121  * NOTE: This text doesn't seem right.  Do this on a socket basis with
3122  * future associations inheriting the socket value.
3123  */
3124 static int sctp_setsockopt_maxburst(struct sock *sk,
3125 				    char __user *optval,
3126 				    unsigned int optlen)
3127 {
3128 	struct sctp_assoc_value params;
3129 	struct sctp_sock *sp;
3130 	struct sctp_association *asoc;
3131 	int val;
3132 	int assoc_id = 0;
3133 
3134 	if (optlen == sizeof(int)) {
3135 		printk(KERN_WARNING
3136 		   "SCTP: Use of int in max_burst socket option deprecated\n");
3137 		printk(KERN_WARNING
3138 		   "SCTP: Use struct sctp_assoc_value instead\n");
3139 		if (copy_from_user(&val, optval, optlen))
3140 			return -EFAULT;
3141 	} else if (optlen == sizeof(struct sctp_assoc_value)) {
3142 		if (copy_from_user(&params, optval, optlen))
3143 			return -EFAULT;
3144 		val = params.assoc_value;
3145 		assoc_id = params.assoc_id;
3146 	} else
3147 		return -EINVAL;
3148 
3149 	sp = sctp_sk(sk);
3150 
3151 	if (assoc_id != 0) {
3152 		asoc = sctp_id2assoc(sk, assoc_id);
3153 		if (!asoc)
3154 			return -EINVAL;
3155 		asoc->max_burst = val;
3156 	} else
3157 		sp->max_burst = val;
3158 
3159 	return 0;
3160 }
3161 
3162 /*
3163  * 7.1.18.  Add a chunk that must be authenticated (SCTP_AUTH_CHUNK)
3164  *
3165  * This set option adds a chunk type that the user is requesting to be
3166  * received only in an authenticated way.  Changes to the list of chunks
3167  * will only effect future associations on the socket.
3168  */
3169 static int sctp_setsockopt_auth_chunk(struct sock *sk,
3170 				      char __user *optval,
3171 				      unsigned int optlen)
3172 {
3173 	struct sctp_authchunk val;
3174 
3175 	if (!sctp_auth_enable)
3176 		return -EACCES;
3177 
3178 	if (optlen != sizeof(struct sctp_authchunk))
3179 		return -EINVAL;
3180 	if (copy_from_user(&val, optval, optlen))
3181 		return -EFAULT;
3182 
3183 	switch (val.sauth_chunk) {
3184 		case SCTP_CID_INIT:
3185 		case SCTP_CID_INIT_ACK:
3186 		case SCTP_CID_SHUTDOWN_COMPLETE:
3187 		case SCTP_CID_AUTH:
3188 			return -EINVAL;
3189 	}
3190 
3191 	/* add this chunk id to the endpoint */
3192 	return sctp_auth_ep_add_chunkid(sctp_sk(sk)->ep, val.sauth_chunk);
3193 }
3194 
3195 /*
3196  * 7.1.19.  Get or set the list of supported HMAC Identifiers (SCTP_HMAC_IDENT)
3197  *
3198  * This option gets or sets the list of HMAC algorithms that the local
3199  * endpoint requires the peer to use.
3200  */
3201 static int sctp_setsockopt_hmac_ident(struct sock *sk,
3202 				      char __user *optval,
3203 				      unsigned int optlen)
3204 {
3205 	struct sctp_hmacalgo *hmacs;
3206 	u32 idents;
3207 	int err;
3208 
3209 	if (!sctp_auth_enable)
3210 		return -EACCES;
3211 
3212 	if (optlen < sizeof(struct sctp_hmacalgo))
3213 		return -EINVAL;
3214 
3215 	hmacs = kmalloc(optlen, GFP_KERNEL);
3216 	if (!hmacs)
3217 		return -ENOMEM;
3218 
3219 	if (copy_from_user(hmacs, optval, optlen)) {
3220 		err = -EFAULT;
3221 		goto out;
3222 	}
3223 
3224 	idents = hmacs->shmac_num_idents;
3225 	if (idents == 0 || idents > SCTP_AUTH_NUM_HMACS ||
3226 	    (idents * sizeof(u16)) > (optlen - sizeof(struct sctp_hmacalgo))) {
3227 		err = -EINVAL;
3228 		goto out;
3229 	}
3230 
3231 	err = sctp_auth_ep_set_hmacs(sctp_sk(sk)->ep, hmacs);
3232 out:
3233 	kfree(hmacs);
3234 	return err;
3235 }
3236 
3237 /*
3238  * 7.1.20.  Set a shared key (SCTP_AUTH_KEY)
3239  *
3240  * This option will set a shared secret key which is used to build an
3241  * association shared key.
3242  */
3243 static int sctp_setsockopt_auth_key(struct sock *sk,
3244 				    char __user *optval,
3245 				    unsigned int optlen)
3246 {
3247 	struct sctp_authkey *authkey;
3248 	struct sctp_association *asoc;
3249 	int ret;
3250 
3251 	if (!sctp_auth_enable)
3252 		return -EACCES;
3253 
3254 	if (optlen <= sizeof(struct sctp_authkey))
3255 		return -EINVAL;
3256 
3257 	authkey = kmalloc(optlen, GFP_KERNEL);
3258 	if (!authkey)
3259 		return -ENOMEM;
3260 
3261 	if (copy_from_user(authkey, optval, optlen)) {
3262 		ret = -EFAULT;
3263 		goto out;
3264 	}
3265 
3266 	if (authkey->sca_keylength > optlen - sizeof(struct sctp_authkey)) {
3267 		ret = -EINVAL;
3268 		goto out;
3269 	}
3270 
3271 	asoc = sctp_id2assoc(sk, authkey->sca_assoc_id);
3272 	if (!asoc && authkey->sca_assoc_id && sctp_style(sk, UDP)) {
3273 		ret = -EINVAL;
3274 		goto out;
3275 	}
3276 
3277 	ret = sctp_auth_set_key(sctp_sk(sk)->ep, asoc, authkey);
3278 out:
3279 	kfree(authkey);
3280 	return ret;
3281 }
3282 
3283 /*
3284  * 7.1.21.  Get or set the active shared key (SCTP_AUTH_ACTIVE_KEY)
3285  *
3286  * This option will get or set the active shared key to be used to build
3287  * the association shared key.
3288  */
3289 static int sctp_setsockopt_active_key(struct sock *sk,
3290 				      char __user *optval,
3291 				      unsigned int optlen)
3292 {
3293 	struct sctp_authkeyid val;
3294 	struct sctp_association *asoc;
3295 
3296 	if (!sctp_auth_enable)
3297 		return -EACCES;
3298 
3299 	if (optlen != sizeof(struct sctp_authkeyid))
3300 		return -EINVAL;
3301 	if (copy_from_user(&val, optval, optlen))
3302 		return -EFAULT;
3303 
3304 	asoc = sctp_id2assoc(sk, val.scact_assoc_id);
3305 	if (!asoc && val.scact_assoc_id && sctp_style(sk, UDP))
3306 		return -EINVAL;
3307 
3308 	return sctp_auth_set_active_key(sctp_sk(sk)->ep, asoc,
3309 					val.scact_keynumber);
3310 }
3311 
3312 /*
3313  * 7.1.22.  Delete a shared key (SCTP_AUTH_DELETE_KEY)
3314  *
3315  * This set option will delete a shared secret key from use.
3316  */
3317 static int sctp_setsockopt_del_key(struct sock *sk,
3318 				   char __user *optval,
3319 				   unsigned int optlen)
3320 {
3321 	struct sctp_authkeyid val;
3322 	struct sctp_association *asoc;
3323 
3324 	if (!sctp_auth_enable)
3325 		return -EACCES;
3326 
3327 	if (optlen != sizeof(struct sctp_authkeyid))
3328 		return -EINVAL;
3329 	if (copy_from_user(&val, optval, optlen))
3330 		return -EFAULT;
3331 
3332 	asoc = sctp_id2assoc(sk, val.scact_assoc_id);
3333 	if (!asoc && val.scact_assoc_id && sctp_style(sk, UDP))
3334 		return -EINVAL;
3335 
3336 	return sctp_auth_del_key_id(sctp_sk(sk)->ep, asoc,
3337 				    val.scact_keynumber);
3338 
3339 }
3340 
3341 
3342 /* API 6.2 setsockopt(), getsockopt()
3343  *
3344  * Applications use setsockopt() and getsockopt() to set or retrieve
3345  * socket options.  Socket options are used to change the default
3346  * behavior of sockets calls.  They are described in Section 7.
3347  *
3348  * The syntax is:
3349  *
3350  *   ret = getsockopt(int sd, int level, int optname, void __user *optval,
3351  *                    int __user *optlen);
3352  *   ret = setsockopt(int sd, int level, int optname, const void __user *optval,
3353  *                    int optlen);
3354  *
3355  *   sd      - the socket descript.
3356  *   level   - set to IPPROTO_SCTP for all SCTP options.
3357  *   optname - the option name.
3358  *   optval  - the buffer to store the value of the option.
3359  *   optlen  - the size of the buffer.
3360  */
3361 SCTP_STATIC int sctp_setsockopt(struct sock *sk, int level, int optname,
3362 				char __user *optval, unsigned int optlen)
3363 {
3364 	int retval = 0;
3365 
3366 	SCTP_DEBUG_PRINTK("sctp_setsockopt(sk: %p... optname: %d)\n",
3367 			  sk, optname);
3368 
3369 	/* I can hardly begin to describe how wrong this is.  This is
3370 	 * so broken as to be worse than useless.  The API draft
3371 	 * REALLY is NOT helpful here...  I am not convinced that the
3372 	 * semantics of setsockopt() with a level OTHER THAN SOL_SCTP
3373 	 * are at all well-founded.
3374 	 */
3375 	if (level != SOL_SCTP) {
3376 		struct sctp_af *af = sctp_sk(sk)->pf->af;
3377 		retval = af->setsockopt(sk, level, optname, optval, optlen);
3378 		goto out_nounlock;
3379 	}
3380 
3381 	sctp_lock_sock(sk);
3382 
3383 	switch (optname) {
3384 	case SCTP_SOCKOPT_BINDX_ADD:
3385 		/* 'optlen' is the size of the addresses buffer. */
3386 		retval = sctp_setsockopt_bindx(sk, (struct sockaddr __user *)optval,
3387 					       optlen, SCTP_BINDX_ADD_ADDR);
3388 		break;
3389 
3390 	case SCTP_SOCKOPT_BINDX_REM:
3391 		/* 'optlen' is the size of the addresses buffer. */
3392 		retval = sctp_setsockopt_bindx(sk, (struct sockaddr __user *)optval,
3393 					       optlen, SCTP_BINDX_REM_ADDR);
3394 		break;
3395 
3396 	case SCTP_SOCKOPT_CONNECTX_OLD:
3397 		/* 'optlen' is the size of the addresses buffer. */
3398 		retval = sctp_setsockopt_connectx_old(sk,
3399 					    (struct sockaddr __user *)optval,
3400 					    optlen);
3401 		break;
3402 
3403 	case SCTP_SOCKOPT_CONNECTX:
3404 		/* 'optlen' is the size of the addresses buffer. */
3405 		retval = sctp_setsockopt_connectx(sk,
3406 					    (struct sockaddr __user *)optval,
3407 					    optlen);
3408 		break;
3409 
3410 	case SCTP_DISABLE_FRAGMENTS:
3411 		retval = sctp_setsockopt_disable_fragments(sk, optval, optlen);
3412 		break;
3413 
3414 	case SCTP_EVENTS:
3415 		retval = sctp_setsockopt_events(sk, optval, optlen);
3416 		break;
3417 
3418 	case SCTP_AUTOCLOSE:
3419 		retval = sctp_setsockopt_autoclose(sk, optval, optlen);
3420 		break;
3421 
3422 	case SCTP_PEER_ADDR_PARAMS:
3423 		retval = sctp_setsockopt_peer_addr_params(sk, optval, optlen);
3424 		break;
3425 
3426 	case SCTP_DELAYED_ACK:
3427 		retval = sctp_setsockopt_delayed_ack(sk, optval, optlen);
3428 		break;
3429 	case SCTP_PARTIAL_DELIVERY_POINT:
3430 		retval = sctp_setsockopt_partial_delivery_point(sk, optval, optlen);
3431 		break;
3432 
3433 	case SCTP_INITMSG:
3434 		retval = sctp_setsockopt_initmsg(sk, optval, optlen);
3435 		break;
3436 	case SCTP_DEFAULT_SEND_PARAM:
3437 		retval = sctp_setsockopt_default_send_param(sk, optval,
3438 							    optlen);
3439 		break;
3440 	case SCTP_PRIMARY_ADDR:
3441 		retval = sctp_setsockopt_primary_addr(sk, optval, optlen);
3442 		break;
3443 	case SCTP_SET_PEER_PRIMARY_ADDR:
3444 		retval = sctp_setsockopt_peer_primary_addr(sk, optval, optlen);
3445 		break;
3446 	case SCTP_NODELAY:
3447 		retval = sctp_setsockopt_nodelay(sk, optval, optlen);
3448 		break;
3449 	case SCTP_RTOINFO:
3450 		retval = sctp_setsockopt_rtoinfo(sk, optval, optlen);
3451 		break;
3452 	case SCTP_ASSOCINFO:
3453 		retval = sctp_setsockopt_associnfo(sk, optval, optlen);
3454 		break;
3455 	case SCTP_I_WANT_MAPPED_V4_ADDR:
3456 		retval = sctp_setsockopt_mappedv4(sk, optval, optlen);
3457 		break;
3458 	case SCTP_MAXSEG:
3459 		retval = sctp_setsockopt_maxseg(sk, optval, optlen);
3460 		break;
3461 	case SCTP_ADAPTATION_LAYER:
3462 		retval = sctp_setsockopt_adaptation_layer(sk, optval, optlen);
3463 		break;
3464 	case SCTP_CONTEXT:
3465 		retval = sctp_setsockopt_context(sk, optval, optlen);
3466 		break;
3467 	case SCTP_FRAGMENT_INTERLEAVE:
3468 		retval = sctp_setsockopt_fragment_interleave(sk, optval, optlen);
3469 		break;
3470 	case SCTP_MAX_BURST:
3471 		retval = sctp_setsockopt_maxburst(sk, optval, optlen);
3472 		break;
3473 	case SCTP_AUTH_CHUNK:
3474 		retval = sctp_setsockopt_auth_chunk(sk, optval, optlen);
3475 		break;
3476 	case SCTP_HMAC_IDENT:
3477 		retval = sctp_setsockopt_hmac_ident(sk, optval, optlen);
3478 		break;
3479 	case SCTP_AUTH_KEY:
3480 		retval = sctp_setsockopt_auth_key(sk, optval, optlen);
3481 		break;
3482 	case SCTP_AUTH_ACTIVE_KEY:
3483 		retval = sctp_setsockopt_active_key(sk, optval, optlen);
3484 		break;
3485 	case SCTP_AUTH_DELETE_KEY:
3486 		retval = sctp_setsockopt_del_key(sk, optval, optlen);
3487 		break;
3488 	default:
3489 		retval = -ENOPROTOOPT;
3490 		break;
3491 	}
3492 
3493 	sctp_release_sock(sk);
3494 
3495 out_nounlock:
3496 	return retval;
3497 }
3498 
3499 /* API 3.1.6 connect() - UDP Style Syntax
3500  *
3501  * An application may use the connect() call in the UDP model to initiate an
3502  * association without sending data.
3503  *
3504  * The syntax is:
3505  *
3506  * ret = connect(int sd, const struct sockaddr *nam, socklen_t len);
3507  *
3508  * sd: the socket descriptor to have a new association added to.
3509  *
3510  * nam: the address structure (either struct sockaddr_in or struct
3511  *    sockaddr_in6 defined in RFC2553 [7]).
3512  *
3513  * len: the size of the address.
3514  */
3515 SCTP_STATIC int sctp_connect(struct sock *sk, struct sockaddr *addr,
3516 			     int addr_len)
3517 {
3518 	int err = 0;
3519 	struct sctp_af *af;
3520 
3521 	sctp_lock_sock(sk);
3522 
3523 	SCTP_DEBUG_PRINTK("%s - sk: %p, sockaddr: %p, addr_len: %d\n",
3524 			  __func__, sk, addr, addr_len);
3525 
3526 	/* Validate addr_len before calling common connect/connectx routine. */
3527 	af = sctp_get_af_specific(addr->sa_family);
3528 	if (!af || addr_len < af->sockaddr_len) {
3529 		err = -EINVAL;
3530 	} else {
3531 		/* Pass correct addr len to common routine (so it knows there
3532 		 * is only one address being passed.
3533 		 */
3534 		err = __sctp_connect(sk, addr, af->sockaddr_len, NULL);
3535 	}
3536 
3537 	sctp_release_sock(sk);
3538 	return err;
3539 }
3540 
3541 /* FIXME: Write comments. */
3542 SCTP_STATIC int sctp_disconnect(struct sock *sk, int flags)
3543 {
3544 	return -EOPNOTSUPP; /* STUB */
3545 }
3546 
3547 /* 4.1.4 accept() - TCP Style Syntax
3548  *
3549  * Applications use accept() call to remove an established SCTP
3550  * association from the accept queue of the endpoint.  A new socket
3551  * descriptor will be returned from accept() to represent the newly
3552  * formed association.
3553  */
3554 SCTP_STATIC struct sock *sctp_accept(struct sock *sk, int flags, int *err)
3555 {
3556 	struct sctp_sock *sp;
3557 	struct sctp_endpoint *ep;
3558 	struct sock *newsk = NULL;
3559 	struct sctp_association *asoc;
3560 	long timeo;
3561 	int error = 0;
3562 
3563 	sctp_lock_sock(sk);
3564 
3565 	sp = sctp_sk(sk);
3566 	ep = sp->ep;
3567 
3568 	if (!sctp_style(sk, TCP)) {
3569 		error = -EOPNOTSUPP;
3570 		goto out;
3571 	}
3572 
3573 	if (!sctp_sstate(sk, LISTENING)) {
3574 		error = -EINVAL;
3575 		goto out;
3576 	}
3577 
3578 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
3579 
3580 	error = sctp_wait_for_accept(sk, timeo);
3581 	if (error)
3582 		goto out;
3583 
3584 	/* We treat the list of associations on the endpoint as the accept
3585 	 * queue and pick the first association on the list.
3586 	 */
3587 	asoc = list_entry(ep->asocs.next, struct sctp_association, asocs);
3588 
3589 	newsk = sp->pf->create_accept_sk(sk, asoc);
3590 	if (!newsk) {
3591 		error = -ENOMEM;
3592 		goto out;
3593 	}
3594 
3595 	/* Populate the fields of the newsk from the oldsk and migrate the
3596 	 * asoc to the newsk.
3597 	 */
3598 	sctp_sock_migrate(sk, newsk, asoc, SCTP_SOCKET_TCP);
3599 
3600 out:
3601 	sctp_release_sock(sk);
3602 	*err = error;
3603 	return newsk;
3604 }
3605 
3606 /* The SCTP ioctl handler. */
3607 SCTP_STATIC int sctp_ioctl(struct sock *sk, int cmd, unsigned long arg)
3608 {
3609 	return -ENOIOCTLCMD;
3610 }
3611 
3612 /* This is the function which gets called during socket creation to
3613  * initialized the SCTP-specific portion of the sock.
3614  * The sock structure should already be zero-filled memory.
3615  */
3616 SCTP_STATIC int sctp_init_sock(struct sock *sk)
3617 {
3618 	struct sctp_endpoint *ep;
3619 	struct sctp_sock *sp;
3620 
3621 	SCTP_DEBUG_PRINTK("sctp_init_sock(sk: %p)\n", sk);
3622 
3623 	sp = sctp_sk(sk);
3624 
3625 	/* Initialize the SCTP per socket area.  */
3626 	switch (sk->sk_type) {
3627 	case SOCK_SEQPACKET:
3628 		sp->type = SCTP_SOCKET_UDP;
3629 		break;
3630 	case SOCK_STREAM:
3631 		sp->type = SCTP_SOCKET_TCP;
3632 		break;
3633 	default:
3634 		return -ESOCKTNOSUPPORT;
3635 	}
3636 
3637 	/* Initialize default send parameters. These parameters can be
3638 	 * modified with the SCTP_DEFAULT_SEND_PARAM socket option.
3639 	 */
3640 	sp->default_stream = 0;
3641 	sp->default_ppid = 0;
3642 	sp->default_flags = 0;
3643 	sp->default_context = 0;
3644 	sp->default_timetolive = 0;
3645 
3646 	sp->default_rcv_context = 0;
3647 	sp->max_burst = sctp_max_burst;
3648 
3649 	/* Initialize default setup parameters. These parameters
3650 	 * can be modified with the SCTP_INITMSG socket option or
3651 	 * overridden by the SCTP_INIT CMSG.
3652 	 */
3653 	sp->initmsg.sinit_num_ostreams   = sctp_max_outstreams;
3654 	sp->initmsg.sinit_max_instreams  = sctp_max_instreams;
3655 	sp->initmsg.sinit_max_attempts   = sctp_max_retrans_init;
3656 	sp->initmsg.sinit_max_init_timeo = sctp_rto_max;
3657 
3658 	/* Initialize default RTO related parameters.  These parameters can
3659 	 * be modified for with the SCTP_RTOINFO socket option.
3660 	 */
3661 	sp->rtoinfo.srto_initial = sctp_rto_initial;
3662 	sp->rtoinfo.srto_max     = sctp_rto_max;
3663 	sp->rtoinfo.srto_min     = sctp_rto_min;
3664 
3665 	/* Initialize default association related parameters. These parameters
3666 	 * can be modified with the SCTP_ASSOCINFO socket option.
3667 	 */
3668 	sp->assocparams.sasoc_asocmaxrxt = sctp_max_retrans_association;
3669 	sp->assocparams.sasoc_number_peer_destinations = 0;
3670 	sp->assocparams.sasoc_peer_rwnd = 0;
3671 	sp->assocparams.sasoc_local_rwnd = 0;
3672 	sp->assocparams.sasoc_cookie_life = sctp_valid_cookie_life;
3673 
3674 	/* Initialize default event subscriptions. By default, all the
3675 	 * options are off.
3676 	 */
3677 	memset(&sp->subscribe, 0, sizeof(struct sctp_event_subscribe));
3678 
3679 	/* Default Peer Address Parameters.  These defaults can
3680 	 * be modified via SCTP_PEER_ADDR_PARAMS
3681 	 */
3682 	sp->hbinterval  = sctp_hb_interval;
3683 	sp->pathmaxrxt  = sctp_max_retrans_path;
3684 	sp->pathmtu     = 0; // allow default discovery
3685 	sp->sackdelay   = sctp_sack_timeout;
3686 	sp->sackfreq	= 2;
3687 	sp->param_flags = SPP_HB_ENABLE |
3688 			  SPP_PMTUD_ENABLE |
3689 			  SPP_SACKDELAY_ENABLE;
3690 
3691 	/* If enabled no SCTP message fragmentation will be performed.
3692 	 * Configure through SCTP_DISABLE_FRAGMENTS socket option.
3693 	 */
3694 	sp->disable_fragments = 0;
3695 
3696 	/* Enable Nagle algorithm by default.  */
3697 	sp->nodelay           = 0;
3698 
3699 	/* Enable by default. */
3700 	sp->v4mapped          = 1;
3701 
3702 	/* Auto-close idle associations after the configured
3703 	 * number of seconds.  A value of 0 disables this
3704 	 * feature.  Configure through the SCTP_AUTOCLOSE socket option,
3705 	 * for UDP-style sockets only.
3706 	 */
3707 	sp->autoclose         = 0;
3708 
3709 	/* User specified fragmentation limit. */
3710 	sp->user_frag         = 0;
3711 
3712 	sp->adaptation_ind = 0;
3713 
3714 	sp->pf = sctp_get_pf_specific(sk->sk_family);
3715 
3716 	/* Control variables for partial data delivery. */
3717 	atomic_set(&sp->pd_mode, 0);
3718 	skb_queue_head_init(&sp->pd_lobby);
3719 	sp->frag_interleave = 0;
3720 
3721 	/* Create a per socket endpoint structure.  Even if we
3722 	 * change the data structure relationships, this may still
3723 	 * be useful for storing pre-connect address information.
3724 	 */
3725 	ep = sctp_endpoint_new(sk, GFP_KERNEL);
3726 	if (!ep)
3727 		return -ENOMEM;
3728 
3729 	sp->ep = ep;
3730 	sp->hmac = NULL;
3731 
3732 	SCTP_DBG_OBJCNT_INC(sock);
3733 
3734 	local_bh_disable();
3735 	percpu_counter_inc(&sctp_sockets_allocated);
3736 	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
3737 	local_bh_enable();
3738 
3739 	return 0;
3740 }
3741 
3742 /* Cleanup any SCTP per socket resources.  */
3743 SCTP_STATIC void sctp_destroy_sock(struct sock *sk)
3744 {
3745 	struct sctp_endpoint *ep;
3746 
3747 	SCTP_DEBUG_PRINTK("sctp_destroy_sock(sk: %p)\n", sk);
3748 
3749 	/* Release our hold on the endpoint. */
3750 	ep = sctp_sk(sk)->ep;
3751 	sctp_endpoint_free(ep);
3752 	local_bh_disable();
3753 	percpu_counter_dec(&sctp_sockets_allocated);
3754 	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
3755 	local_bh_enable();
3756 }
3757 
3758 /* API 4.1.7 shutdown() - TCP Style Syntax
3759  *     int shutdown(int socket, int how);
3760  *
3761  *     sd      - the socket descriptor of the association to be closed.
3762  *     how     - Specifies the type of shutdown.  The  values  are
3763  *               as follows:
3764  *               SHUT_RD
3765  *                     Disables further receive operations. No SCTP
3766  *                     protocol action is taken.
3767  *               SHUT_WR
3768  *                     Disables further send operations, and initiates
3769  *                     the SCTP shutdown sequence.
3770  *               SHUT_RDWR
3771  *                     Disables further send  and  receive  operations
3772  *                     and initiates the SCTP shutdown sequence.
3773  */
3774 SCTP_STATIC void sctp_shutdown(struct sock *sk, int how)
3775 {
3776 	struct sctp_endpoint *ep;
3777 	struct sctp_association *asoc;
3778 
3779 	if (!sctp_style(sk, TCP))
3780 		return;
3781 
3782 	if (how & SEND_SHUTDOWN) {
3783 		ep = sctp_sk(sk)->ep;
3784 		if (!list_empty(&ep->asocs)) {
3785 			asoc = list_entry(ep->asocs.next,
3786 					  struct sctp_association, asocs);
3787 			sctp_primitive_SHUTDOWN(asoc, NULL);
3788 		}
3789 	}
3790 }
3791 
3792 /* 7.2.1 Association Status (SCTP_STATUS)
3793 
3794  * Applications can retrieve current status information about an
3795  * association, including association state, peer receiver window size,
3796  * number of unacked data chunks, and number of data chunks pending
3797  * receipt.  This information is read-only.
3798  */
3799 static int sctp_getsockopt_sctp_status(struct sock *sk, int len,
3800 				       char __user *optval,
3801 				       int __user *optlen)
3802 {
3803 	struct sctp_status status;
3804 	struct sctp_association *asoc = NULL;
3805 	struct sctp_transport *transport;
3806 	sctp_assoc_t associd;
3807 	int retval = 0;
3808 
3809 	if (len < sizeof(status)) {
3810 		retval = -EINVAL;
3811 		goto out;
3812 	}
3813 
3814 	len = sizeof(status);
3815 	if (copy_from_user(&status, optval, len)) {
3816 		retval = -EFAULT;
3817 		goto out;
3818 	}
3819 
3820 	associd = status.sstat_assoc_id;
3821 	asoc = sctp_id2assoc(sk, associd);
3822 	if (!asoc) {
3823 		retval = -EINVAL;
3824 		goto out;
3825 	}
3826 
3827 	transport = asoc->peer.primary_path;
3828 
3829 	status.sstat_assoc_id = sctp_assoc2id(asoc);
3830 	status.sstat_state = asoc->state;
3831 	status.sstat_rwnd =  asoc->peer.rwnd;
3832 	status.sstat_unackdata = asoc->unack_data;
3833 
3834 	status.sstat_penddata = sctp_tsnmap_pending(&asoc->peer.tsn_map);
3835 	status.sstat_instrms = asoc->c.sinit_max_instreams;
3836 	status.sstat_outstrms = asoc->c.sinit_num_ostreams;
3837 	status.sstat_fragmentation_point = asoc->frag_point;
3838 	status.sstat_primary.spinfo_assoc_id = sctp_assoc2id(transport->asoc);
3839 	memcpy(&status.sstat_primary.spinfo_address, &transport->ipaddr,
3840 			transport->af_specific->sockaddr_len);
3841 	/* Map ipv4 address into v4-mapped-on-v6 address.  */
3842 	sctp_get_pf_specific(sk->sk_family)->addr_v4map(sctp_sk(sk),
3843 		(union sctp_addr *)&status.sstat_primary.spinfo_address);
3844 	status.sstat_primary.spinfo_state = transport->state;
3845 	status.sstat_primary.spinfo_cwnd = transport->cwnd;
3846 	status.sstat_primary.spinfo_srtt = transport->srtt;
3847 	status.sstat_primary.spinfo_rto = jiffies_to_msecs(transport->rto);
3848 	status.sstat_primary.spinfo_mtu = transport->pathmtu;
3849 
3850 	if (status.sstat_primary.spinfo_state == SCTP_UNKNOWN)
3851 		status.sstat_primary.spinfo_state = SCTP_ACTIVE;
3852 
3853 	if (put_user(len, optlen)) {
3854 		retval = -EFAULT;
3855 		goto out;
3856 	}
3857 
3858 	SCTP_DEBUG_PRINTK("sctp_getsockopt_sctp_status(%d): %d %d %d\n",
3859 			  len, status.sstat_state, status.sstat_rwnd,
3860 			  status.sstat_assoc_id);
3861 
3862 	if (copy_to_user(optval, &status, len)) {
3863 		retval = -EFAULT;
3864 		goto out;
3865 	}
3866 
3867 out:
3868 	return (retval);
3869 }
3870 
3871 
3872 /* 7.2.2 Peer Address Information (SCTP_GET_PEER_ADDR_INFO)
3873  *
3874  * Applications can retrieve information about a specific peer address
3875  * of an association, including its reachability state, congestion
3876  * window, and retransmission timer values.  This information is
3877  * read-only.
3878  */
3879 static int sctp_getsockopt_peer_addr_info(struct sock *sk, int len,
3880 					  char __user *optval,
3881 					  int __user *optlen)
3882 {
3883 	struct sctp_paddrinfo pinfo;
3884 	struct sctp_transport *transport;
3885 	int retval = 0;
3886 
3887 	if (len < sizeof(pinfo)) {
3888 		retval = -EINVAL;
3889 		goto out;
3890 	}
3891 
3892 	len = sizeof(pinfo);
3893 	if (copy_from_user(&pinfo, optval, len)) {
3894 		retval = -EFAULT;
3895 		goto out;
3896 	}
3897 
3898 	transport = sctp_addr_id2transport(sk, &pinfo.spinfo_address,
3899 					   pinfo.spinfo_assoc_id);
3900 	if (!transport)
3901 		return -EINVAL;
3902 
3903 	pinfo.spinfo_assoc_id = sctp_assoc2id(transport->asoc);
3904 	pinfo.spinfo_state = transport->state;
3905 	pinfo.spinfo_cwnd = transport->cwnd;
3906 	pinfo.spinfo_srtt = transport->srtt;
3907 	pinfo.spinfo_rto = jiffies_to_msecs(transport->rto);
3908 	pinfo.spinfo_mtu = transport->pathmtu;
3909 
3910 	if (pinfo.spinfo_state == SCTP_UNKNOWN)
3911 		pinfo.spinfo_state = SCTP_ACTIVE;
3912 
3913 	if (put_user(len, optlen)) {
3914 		retval = -EFAULT;
3915 		goto out;
3916 	}
3917 
3918 	if (copy_to_user(optval, &pinfo, len)) {
3919 		retval = -EFAULT;
3920 		goto out;
3921 	}
3922 
3923 out:
3924 	return (retval);
3925 }
3926 
3927 /* 7.1.12 Enable/Disable message fragmentation (SCTP_DISABLE_FRAGMENTS)
3928  *
3929  * This option is a on/off flag.  If enabled no SCTP message
3930  * fragmentation will be performed.  Instead if a message being sent
3931  * exceeds the current PMTU size, the message will NOT be sent and
3932  * instead a error will be indicated to the user.
3933  */
3934 static int sctp_getsockopt_disable_fragments(struct sock *sk, int len,
3935 					char __user *optval, int __user *optlen)
3936 {
3937 	int val;
3938 
3939 	if (len < sizeof(int))
3940 		return -EINVAL;
3941 
3942 	len = sizeof(int);
3943 	val = (sctp_sk(sk)->disable_fragments == 1);
3944 	if (put_user(len, optlen))
3945 		return -EFAULT;
3946 	if (copy_to_user(optval, &val, len))
3947 		return -EFAULT;
3948 	return 0;
3949 }
3950 
3951 /* 7.1.15 Set notification and ancillary events (SCTP_EVENTS)
3952  *
3953  * This socket option is used to specify various notifications and
3954  * ancillary data the user wishes to receive.
3955  */
3956 static int sctp_getsockopt_events(struct sock *sk, int len, char __user *optval,
3957 				  int __user *optlen)
3958 {
3959 	if (len < sizeof(struct sctp_event_subscribe))
3960 		return -EINVAL;
3961 	len = sizeof(struct sctp_event_subscribe);
3962 	if (put_user(len, optlen))
3963 		return -EFAULT;
3964 	if (copy_to_user(optval, &sctp_sk(sk)->subscribe, len))
3965 		return -EFAULT;
3966 	return 0;
3967 }
3968 
3969 /* 7.1.8 Automatic Close of associations (SCTP_AUTOCLOSE)
3970  *
3971  * This socket option is applicable to the UDP-style socket only.  When
3972  * set it will cause associations that are idle for more than the
3973  * specified number of seconds to automatically close.  An association
3974  * being idle is defined an association that has NOT sent or received
3975  * user data.  The special value of '0' indicates that no automatic
3976  * close of any associations should be performed.  The option expects an
3977  * integer defining the number of seconds of idle time before an
3978  * association is closed.
3979  */
3980 static int sctp_getsockopt_autoclose(struct sock *sk, int len, char __user *optval, int __user *optlen)
3981 {
3982 	/* Applicable to UDP-style socket only */
3983 	if (sctp_style(sk, TCP))
3984 		return -EOPNOTSUPP;
3985 	if (len < sizeof(int))
3986 		return -EINVAL;
3987 	len = sizeof(int);
3988 	if (put_user(len, optlen))
3989 		return -EFAULT;
3990 	if (copy_to_user(optval, &sctp_sk(sk)->autoclose, sizeof(int)))
3991 		return -EFAULT;
3992 	return 0;
3993 }
3994 
3995 /* Helper routine to branch off an association to a new socket.  */
3996 SCTP_STATIC int sctp_do_peeloff(struct sctp_association *asoc,
3997 				struct socket **sockp)
3998 {
3999 	struct sock *sk = asoc->base.sk;
4000 	struct socket *sock;
4001 	struct sctp_af *af;
4002 	int err = 0;
4003 
4004 	/* An association cannot be branched off from an already peeled-off
4005 	 * socket, nor is this supported for tcp style sockets.
4006 	 */
4007 	if (!sctp_style(sk, UDP))
4008 		return -EINVAL;
4009 
4010 	/* Create a new socket.  */
4011 	err = sock_create(sk->sk_family, SOCK_SEQPACKET, IPPROTO_SCTP, &sock);
4012 	if (err < 0)
4013 		return err;
4014 
4015 	sctp_copy_sock(sock->sk, sk, asoc);
4016 
4017 	/* Make peeled-off sockets more like 1-1 accepted sockets.
4018 	 * Set the daddr and initialize id to something more random
4019 	 */
4020 	af = sctp_get_af_specific(asoc->peer.primary_addr.sa.sa_family);
4021 	af->to_sk_daddr(&asoc->peer.primary_addr, sk);
4022 
4023 	/* Populate the fields of the newsk from the oldsk and migrate the
4024 	 * asoc to the newsk.
4025 	 */
4026 	sctp_sock_migrate(sk, sock->sk, asoc, SCTP_SOCKET_UDP_HIGH_BANDWIDTH);
4027 
4028 	*sockp = sock;
4029 
4030 	return err;
4031 }
4032 
4033 static int sctp_getsockopt_peeloff(struct sock *sk, int len, char __user *optval, int __user *optlen)
4034 {
4035 	sctp_peeloff_arg_t peeloff;
4036 	struct socket *newsock;
4037 	int retval = 0;
4038 	struct sctp_association *asoc;
4039 
4040 	if (len < sizeof(sctp_peeloff_arg_t))
4041 		return -EINVAL;
4042 	len = sizeof(sctp_peeloff_arg_t);
4043 	if (copy_from_user(&peeloff, optval, len))
4044 		return -EFAULT;
4045 
4046 	asoc = sctp_id2assoc(sk, peeloff.associd);
4047 	if (!asoc) {
4048 		retval = -EINVAL;
4049 		goto out;
4050 	}
4051 
4052 	SCTP_DEBUG_PRINTK("%s: sk: %p asoc: %p\n", __func__, sk, asoc);
4053 
4054 	retval = sctp_do_peeloff(asoc, &newsock);
4055 	if (retval < 0)
4056 		goto out;
4057 
4058 	/* Map the socket to an unused fd that can be returned to the user.  */
4059 	retval = sock_map_fd(newsock, 0);
4060 	if (retval < 0) {
4061 		sock_release(newsock);
4062 		goto out;
4063 	}
4064 
4065 	SCTP_DEBUG_PRINTK("%s: sk: %p asoc: %p newsk: %p sd: %d\n",
4066 			  __func__, sk, asoc, newsock->sk, retval);
4067 
4068 	/* Return the fd mapped to the new socket.  */
4069 	peeloff.sd = retval;
4070 	if (put_user(len, optlen))
4071 		return -EFAULT;
4072 	if (copy_to_user(optval, &peeloff, len))
4073 		retval = -EFAULT;
4074 
4075 out:
4076 	return retval;
4077 }
4078 
4079 /* 7.1.13 Peer Address Parameters (SCTP_PEER_ADDR_PARAMS)
4080  *
4081  * Applications can enable or disable heartbeats for any peer address of
4082  * an association, modify an address's heartbeat interval, force a
4083  * heartbeat to be sent immediately, and adjust the address's maximum
4084  * number of retransmissions sent before an address is considered
4085  * unreachable.  The following structure is used to access and modify an
4086  * address's parameters:
4087  *
4088  *  struct sctp_paddrparams {
4089  *     sctp_assoc_t            spp_assoc_id;
4090  *     struct sockaddr_storage spp_address;
4091  *     uint32_t                spp_hbinterval;
4092  *     uint16_t                spp_pathmaxrxt;
4093  *     uint32_t                spp_pathmtu;
4094  *     uint32_t                spp_sackdelay;
4095  *     uint32_t                spp_flags;
4096  * };
4097  *
4098  *   spp_assoc_id    - (one-to-many style socket) This is filled in the
4099  *                     application, and identifies the association for
4100  *                     this query.
4101  *   spp_address     - This specifies which address is of interest.
4102  *   spp_hbinterval  - This contains the value of the heartbeat interval,
4103  *                     in milliseconds.  If a  value of zero
4104  *                     is present in this field then no changes are to
4105  *                     be made to this parameter.
4106  *   spp_pathmaxrxt  - This contains the maximum number of
4107  *                     retransmissions before this address shall be
4108  *                     considered unreachable. If a  value of zero
4109  *                     is present in this field then no changes are to
4110  *                     be made to this parameter.
4111  *   spp_pathmtu     - When Path MTU discovery is disabled the value
4112  *                     specified here will be the "fixed" path mtu.
4113  *                     Note that if the spp_address field is empty
4114  *                     then all associations on this address will
4115  *                     have this fixed path mtu set upon them.
4116  *
4117  *   spp_sackdelay   - When delayed sack is enabled, this value specifies
4118  *                     the number of milliseconds that sacks will be delayed
4119  *                     for. This value will apply to all addresses of an
4120  *                     association if the spp_address field is empty. Note
4121  *                     also, that if delayed sack is enabled and this
4122  *                     value is set to 0, no change is made to the last
4123  *                     recorded delayed sack timer value.
4124  *
4125  *   spp_flags       - These flags are used to control various features
4126  *                     on an association. The flag field may contain
4127  *                     zero or more of the following options.
4128  *
4129  *                     SPP_HB_ENABLE  - Enable heartbeats on the
4130  *                     specified address. Note that if the address
4131  *                     field is empty all addresses for the association
4132  *                     have heartbeats enabled upon them.
4133  *
4134  *                     SPP_HB_DISABLE - Disable heartbeats on the
4135  *                     speicifed address. Note that if the address
4136  *                     field is empty all addresses for the association
4137  *                     will have their heartbeats disabled. Note also
4138  *                     that SPP_HB_ENABLE and SPP_HB_DISABLE are
4139  *                     mutually exclusive, only one of these two should
4140  *                     be specified. Enabling both fields will have
4141  *                     undetermined results.
4142  *
4143  *                     SPP_HB_DEMAND - Request a user initiated heartbeat
4144  *                     to be made immediately.
4145  *
4146  *                     SPP_PMTUD_ENABLE - This field will enable PMTU
4147  *                     discovery upon the specified address. Note that
4148  *                     if the address feild is empty then all addresses
4149  *                     on the association are effected.
4150  *
4151  *                     SPP_PMTUD_DISABLE - This field will disable PMTU
4152  *                     discovery upon the specified address. Note that
4153  *                     if the address feild is empty then all addresses
4154  *                     on the association are effected. Not also that
4155  *                     SPP_PMTUD_ENABLE and SPP_PMTUD_DISABLE are mutually
4156  *                     exclusive. Enabling both will have undetermined
4157  *                     results.
4158  *
4159  *                     SPP_SACKDELAY_ENABLE - Setting this flag turns
4160  *                     on delayed sack. The time specified in spp_sackdelay
4161  *                     is used to specify the sack delay for this address. Note
4162  *                     that if spp_address is empty then all addresses will
4163  *                     enable delayed sack and take on the sack delay
4164  *                     value specified in spp_sackdelay.
4165  *                     SPP_SACKDELAY_DISABLE - Setting this flag turns
4166  *                     off delayed sack. If the spp_address field is blank then
4167  *                     delayed sack is disabled for the entire association. Note
4168  *                     also that this field is mutually exclusive to
4169  *                     SPP_SACKDELAY_ENABLE, setting both will have undefined
4170  *                     results.
4171  */
4172 static int sctp_getsockopt_peer_addr_params(struct sock *sk, int len,
4173 					    char __user *optval, int __user *optlen)
4174 {
4175 	struct sctp_paddrparams  params;
4176 	struct sctp_transport   *trans = NULL;
4177 	struct sctp_association *asoc = NULL;
4178 	struct sctp_sock        *sp = sctp_sk(sk);
4179 
4180 	if (len < sizeof(struct sctp_paddrparams))
4181 		return -EINVAL;
4182 	len = sizeof(struct sctp_paddrparams);
4183 	if (copy_from_user(&params, optval, len))
4184 		return -EFAULT;
4185 
4186 	/* If an address other than INADDR_ANY is specified, and
4187 	 * no transport is found, then the request is invalid.
4188 	 */
4189 	if (!sctp_is_any(sk, ( union sctp_addr *)&params.spp_address)) {
4190 		trans = sctp_addr_id2transport(sk, &params.spp_address,
4191 					       params.spp_assoc_id);
4192 		if (!trans) {
4193 			SCTP_DEBUG_PRINTK("Failed no transport\n");
4194 			return -EINVAL;
4195 		}
4196 	}
4197 
4198 	/* Get association, if assoc_id != 0 and the socket is a one
4199 	 * to many style socket, and an association was not found, then
4200 	 * the id was invalid.
4201 	 */
4202 	asoc = sctp_id2assoc(sk, params.spp_assoc_id);
4203 	if (!asoc && params.spp_assoc_id && sctp_style(sk, UDP)) {
4204 		SCTP_DEBUG_PRINTK("Failed no association\n");
4205 		return -EINVAL;
4206 	}
4207 
4208 	if (trans) {
4209 		/* Fetch transport values. */
4210 		params.spp_hbinterval = jiffies_to_msecs(trans->hbinterval);
4211 		params.spp_pathmtu    = trans->pathmtu;
4212 		params.spp_pathmaxrxt = trans->pathmaxrxt;
4213 		params.spp_sackdelay  = jiffies_to_msecs(trans->sackdelay);
4214 
4215 		/*draft-11 doesn't say what to return in spp_flags*/
4216 		params.spp_flags      = trans->param_flags;
4217 	} else if (asoc) {
4218 		/* Fetch association values. */
4219 		params.spp_hbinterval = jiffies_to_msecs(asoc->hbinterval);
4220 		params.spp_pathmtu    = asoc->pathmtu;
4221 		params.spp_pathmaxrxt = asoc->pathmaxrxt;
4222 		params.spp_sackdelay  = jiffies_to_msecs(asoc->sackdelay);
4223 
4224 		/*draft-11 doesn't say what to return in spp_flags*/
4225 		params.spp_flags      = asoc->param_flags;
4226 	} else {
4227 		/* Fetch socket values. */
4228 		params.spp_hbinterval = sp->hbinterval;
4229 		params.spp_pathmtu    = sp->pathmtu;
4230 		params.spp_sackdelay  = sp->sackdelay;
4231 		params.spp_pathmaxrxt = sp->pathmaxrxt;
4232 
4233 		/*draft-11 doesn't say what to return in spp_flags*/
4234 		params.spp_flags      = sp->param_flags;
4235 	}
4236 
4237 	if (copy_to_user(optval, &params, len))
4238 		return -EFAULT;
4239 
4240 	if (put_user(len, optlen))
4241 		return -EFAULT;
4242 
4243 	return 0;
4244 }
4245 
4246 /*
4247  * 7.1.23.  Get or set delayed ack timer (SCTP_DELAYED_SACK)
4248  *
4249  * This option will effect the way delayed acks are performed.  This
4250  * option allows you to get or set the delayed ack time, in
4251  * milliseconds.  It also allows changing the delayed ack frequency.
4252  * Changing the frequency to 1 disables the delayed sack algorithm.  If
4253  * the assoc_id is 0, then this sets or gets the endpoints default
4254  * values.  If the assoc_id field is non-zero, then the set or get
4255  * effects the specified association for the one to many model (the
4256  * assoc_id field is ignored by the one to one model).  Note that if
4257  * sack_delay or sack_freq are 0 when setting this option, then the
4258  * current values will remain unchanged.
4259  *
4260  * struct sctp_sack_info {
4261  *     sctp_assoc_t            sack_assoc_id;
4262  *     uint32_t                sack_delay;
4263  *     uint32_t                sack_freq;
4264  * };
4265  *
4266  * sack_assoc_id -  This parameter, indicates which association the user
4267  *    is performing an action upon.  Note that if this field's value is
4268  *    zero then the endpoints default value is changed (effecting future
4269  *    associations only).
4270  *
4271  * sack_delay -  This parameter contains the number of milliseconds that
4272  *    the user is requesting the delayed ACK timer be set to.  Note that
4273  *    this value is defined in the standard to be between 200 and 500
4274  *    milliseconds.
4275  *
4276  * sack_freq -  This parameter contains the number of packets that must
4277  *    be received before a sack is sent without waiting for the delay
4278  *    timer to expire.  The default value for this is 2, setting this
4279  *    value to 1 will disable the delayed sack algorithm.
4280  */
4281 static int sctp_getsockopt_delayed_ack(struct sock *sk, int len,
4282 					    char __user *optval,
4283 					    int __user *optlen)
4284 {
4285 	struct sctp_sack_info    params;
4286 	struct sctp_association *asoc = NULL;
4287 	struct sctp_sock        *sp = sctp_sk(sk);
4288 
4289 	if (len >= sizeof(struct sctp_sack_info)) {
4290 		len = sizeof(struct sctp_sack_info);
4291 
4292 		if (copy_from_user(&params, optval, len))
4293 			return -EFAULT;
4294 	} else if (len == sizeof(struct sctp_assoc_value)) {
4295 		printk(KERN_WARNING "SCTP: Use of struct sctp_assoc_value "
4296 		       "in delayed_ack socket option deprecated\n");
4297 		printk(KERN_WARNING "SCTP: Use struct sctp_sack_info instead\n");
4298 		if (copy_from_user(&params, optval, len))
4299 			return -EFAULT;
4300 	} else
4301 		return - EINVAL;
4302 
4303 	/* Get association, if sack_assoc_id != 0 and the socket is a one
4304 	 * to many style socket, and an association was not found, then
4305 	 * the id was invalid.
4306 	 */
4307 	asoc = sctp_id2assoc(sk, params.sack_assoc_id);
4308 	if (!asoc && params.sack_assoc_id && sctp_style(sk, UDP))
4309 		return -EINVAL;
4310 
4311 	if (asoc) {
4312 		/* Fetch association values. */
4313 		if (asoc->param_flags & SPP_SACKDELAY_ENABLE) {
4314 			params.sack_delay = jiffies_to_msecs(
4315 				asoc->sackdelay);
4316 			params.sack_freq = asoc->sackfreq;
4317 
4318 		} else {
4319 			params.sack_delay = 0;
4320 			params.sack_freq = 1;
4321 		}
4322 	} else {
4323 		/* Fetch socket values. */
4324 		if (sp->param_flags & SPP_SACKDELAY_ENABLE) {
4325 			params.sack_delay  = sp->sackdelay;
4326 			params.sack_freq = sp->sackfreq;
4327 		} else {
4328 			params.sack_delay  = 0;
4329 			params.sack_freq = 1;
4330 		}
4331 	}
4332 
4333 	if (copy_to_user(optval, &params, len))
4334 		return -EFAULT;
4335 
4336 	if (put_user(len, optlen))
4337 		return -EFAULT;
4338 
4339 	return 0;
4340 }
4341 
4342 /* 7.1.3 Initialization Parameters (SCTP_INITMSG)
4343  *
4344  * Applications can specify protocol parameters for the default association
4345  * initialization.  The option name argument to setsockopt() and getsockopt()
4346  * is SCTP_INITMSG.
4347  *
4348  * Setting initialization parameters is effective only on an unconnected
4349  * socket (for UDP-style sockets only future associations are effected
4350  * by the change).  With TCP-style sockets, this option is inherited by
4351  * sockets derived from a listener socket.
4352  */
4353 static int sctp_getsockopt_initmsg(struct sock *sk, int len, char __user *optval, int __user *optlen)
4354 {
4355 	if (len < sizeof(struct sctp_initmsg))
4356 		return -EINVAL;
4357 	len = sizeof(struct sctp_initmsg);
4358 	if (put_user(len, optlen))
4359 		return -EFAULT;
4360 	if (copy_to_user(optval, &sctp_sk(sk)->initmsg, len))
4361 		return -EFAULT;
4362 	return 0;
4363 }
4364 
4365 
4366 static int sctp_getsockopt_peer_addrs(struct sock *sk, int len,
4367 				      char __user *optval, int __user *optlen)
4368 {
4369 	struct sctp_association *asoc;
4370 	int cnt = 0;
4371 	struct sctp_getaddrs getaddrs;
4372 	struct sctp_transport *from;
4373 	void __user *to;
4374 	union sctp_addr temp;
4375 	struct sctp_sock *sp = sctp_sk(sk);
4376 	int addrlen;
4377 	size_t space_left;
4378 	int bytes_copied;
4379 
4380 	if (len < sizeof(struct sctp_getaddrs))
4381 		return -EINVAL;
4382 
4383 	if (copy_from_user(&getaddrs, optval, sizeof(struct sctp_getaddrs)))
4384 		return -EFAULT;
4385 
4386 	/* For UDP-style sockets, id specifies the association to query.  */
4387 	asoc = sctp_id2assoc(sk, getaddrs.assoc_id);
4388 	if (!asoc)
4389 		return -EINVAL;
4390 
4391 	to = optval + offsetof(struct sctp_getaddrs,addrs);
4392 	space_left = len - offsetof(struct sctp_getaddrs,addrs);
4393 
4394 	list_for_each_entry(from, &asoc->peer.transport_addr_list,
4395 				transports) {
4396 		memcpy(&temp, &from->ipaddr, sizeof(temp));
4397 		sctp_get_pf_specific(sk->sk_family)->addr_v4map(sp, &temp);
4398 		addrlen = sctp_get_af_specific(temp.sa.sa_family)->sockaddr_len;
4399 		if (space_left < addrlen)
4400 			return -ENOMEM;
4401 		if (copy_to_user(to, &temp, addrlen))
4402 			return -EFAULT;
4403 		to += addrlen;
4404 		cnt++;
4405 		space_left -= addrlen;
4406 	}
4407 
4408 	if (put_user(cnt, &((struct sctp_getaddrs __user *)optval)->addr_num))
4409 		return -EFAULT;
4410 	bytes_copied = ((char __user *)to) - optval;
4411 	if (put_user(bytes_copied, optlen))
4412 		return -EFAULT;
4413 
4414 	return 0;
4415 }
4416 
4417 static int sctp_copy_laddrs(struct sock *sk, __u16 port, void *to,
4418 			    size_t space_left, int *bytes_copied)
4419 {
4420 	struct sctp_sockaddr_entry *addr;
4421 	union sctp_addr temp;
4422 	int cnt = 0;
4423 	int addrlen;
4424 
4425 	rcu_read_lock();
4426 	list_for_each_entry_rcu(addr, &sctp_local_addr_list, list) {
4427 		if (!addr->valid)
4428 			continue;
4429 
4430 		if ((PF_INET == sk->sk_family) &&
4431 		    (AF_INET6 == addr->a.sa.sa_family))
4432 			continue;
4433 		if ((PF_INET6 == sk->sk_family) &&
4434 		    inet_v6_ipv6only(sk) &&
4435 		    (AF_INET == addr->a.sa.sa_family))
4436 			continue;
4437 		memcpy(&temp, &addr->a, sizeof(temp));
4438 		if (!temp.v4.sin_port)
4439 			temp.v4.sin_port = htons(port);
4440 
4441 		sctp_get_pf_specific(sk->sk_family)->addr_v4map(sctp_sk(sk),
4442 								&temp);
4443 		addrlen = sctp_get_af_specific(temp.sa.sa_family)->sockaddr_len;
4444 		if (space_left < addrlen) {
4445 			cnt =  -ENOMEM;
4446 			break;
4447 		}
4448 		memcpy(to, &temp, addrlen);
4449 
4450 		to += addrlen;
4451 		cnt ++;
4452 		space_left -= addrlen;
4453 		*bytes_copied += addrlen;
4454 	}
4455 	rcu_read_unlock();
4456 
4457 	return cnt;
4458 }
4459 
4460 
4461 static int sctp_getsockopt_local_addrs(struct sock *sk, int len,
4462 				       char __user *optval, int __user *optlen)
4463 {
4464 	struct sctp_bind_addr *bp;
4465 	struct sctp_association *asoc;
4466 	int cnt = 0;
4467 	struct sctp_getaddrs getaddrs;
4468 	struct sctp_sockaddr_entry *addr;
4469 	void __user *to;
4470 	union sctp_addr temp;
4471 	struct sctp_sock *sp = sctp_sk(sk);
4472 	int addrlen;
4473 	int err = 0;
4474 	size_t space_left;
4475 	int bytes_copied = 0;
4476 	void *addrs;
4477 	void *buf;
4478 
4479 	if (len < sizeof(struct sctp_getaddrs))
4480 		return -EINVAL;
4481 
4482 	if (copy_from_user(&getaddrs, optval, sizeof(struct sctp_getaddrs)))
4483 		return -EFAULT;
4484 
4485 	/*
4486 	 *  For UDP-style sockets, id specifies the association to query.
4487 	 *  If the id field is set to the value '0' then the locally bound
4488 	 *  addresses are returned without regard to any particular
4489 	 *  association.
4490 	 */
4491 	if (0 == getaddrs.assoc_id) {
4492 		bp = &sctp_sk(sk)->ep->base.bind_addr;
4493 	} else {
4494 		asoc = sctp_id2assoc(sk, getaddrs.assoc_id);
4495 		if (!asoc)
4496 			return -EINVAL;
4497 		bp = &asoc->base.bind_addr;
4498 	}
4499 
4500 	to = optval + offsetof(struct sctp_getaddrs,addrs);
4501 	space_left = len - offsetof(struct sctp_getaddrs,addrs);
4502 
4503 	addrs = kmalloc(space_left, GFP_KERNEL);
4504 	if (!addrs)
4505 		return -ENOMEM;
4506 
4507 	/* If the endpoint is bound to 0.0.0.0 or ::0, get the valid
4508 	 * addresses from the global local address list.
4509 	 */
4510 	if (sctp_list_single_entry(&bp->address_list)) {
4511 		addr = list_entry(bp->address_list.next,
4512 				  struct sctp_sockaddr_entry, list);
4513 		if (sctp_is_any(sk, &addr->a)) {
4514 			cnt = sctp_copy_laddrs(sk, bp->port, addrs,
4515 						space_left, &bytes_copied);
4516 			if (cnt < 0) {
4517 				err = cnt;
4518 				goto out;
4519 			}
4520 			goto copy_getaddrs;
4521 		}
4522 	}
4523 
4524 	buf = addrs;
4525 	/* Protection on the bound address list is not needed since
4526 	 * in the socket option context we hold a socket lock and
4527 	 * thus the bound address list can't change.
4528 	 */
4529 	list_for_each_entry(addr, &bp->address_list, list) {
4530 		memcpy(&temp, &addr->a, sizeof(temp));
4531 		sctp_get_pf_specific(sk->sk_family)->addr_v4map(sp, &temp);
4532 		addrlen = sctp_get_af_specific(temp.sa.sa_family)->sockaddr_len;
4533 		if (space_left < addrlen) {
4534 			err =  -ENOMEM; /*fixme: right error?*/
4535 			goto out;
4536 		}
4537 		memcpy(buf, &temp, addrlen);
4538 		buf += addrlen;
4539 		bytes_copied += addrlen;
4540 		cnt ++;
4541 		space_left -= addrlen;
4542 	}
4543 
4544 copy_getaddrs:
4545 	if (copy_to_user(to, addrs, bytes_copied)) {
4546 		err = -EFAULT;
4547 		goto out;
4548 	}
4549 	if (put_user(cnt, &((struct sctp_getaddrs __user *)optval)->addr_num)) {
4550 		err = -EFAULT;
4551 		goto out;
4552 	}
4553 	if (put_user(bytes_copied, optlen))
4554 		err = -EFAULT;
4555 out:
4556 	kfree(addrs);
4557 	return err;
4558 }
4559 
4560 /* 7.1.10 Set Primary Address (SCTP_PRIMARY_ADDR)
4561  *
4562  * Requests that the local SCTP stack use the enclosed peer address as
4563  * the association primary.  The enclosed address must be one of the
4564  * association peer's addresses.
4565  */
4566 static int sctp_getsockopt_primary_addr(struct sock *sk, int len,
4567 					char __user *optval, int __user *optlen)
4568 {
4569 	struct sctp_prim prim;
4570 	struct sctp_association *asoc;
4571 	struct sctp_sock *sp = sctp_sk(sk);
4572 
4573 	if (len < sizeof(struct sctp_prim))
4574 		return -EINVAL;
4575 
4576 	len = sizeof(struct sctp_prim);
4577 
4578 	if (copy_from_user(&prim, optval, len))
4579 		return -EFAULT;
4580 
4581 	asoc = sctp_id2assoc(sk, prim.ssp_assoc_id);
4582 	if (!asoc)
4583 		return -EINVAL;
4584 
4585 	if (!asoc->peer.primary_path)
4586 		return -ENOTCONN;
4587 
4588 	memcpy(&prim.ssp_addr, &asoc->peer.primary_path->ipaddr,
4589 		asoc->peer.primary_path->af_specific->sockaddr_len);
4590 
4591 	sctp_get_pf_specific(sk->sk_family)->addr_v4map(sp,
4592 			(union sctp_addr *)&prim.ssp_addr);
4593 
4594 	if (put_user(len, optlen))
4595 		return -EFAULT;
4596 	if (copy_to_user(optval, &prim, len))
4597 		return -EFAULT;
4598 
4599 	return 0;
4600 }
4601 
4602 /*
4603  * 7.1.11  Set Adaptation Layer Indicator (SCTP_ADAPTATION_LAYER)
4604  *
4605  * Requests that the local endpoint set the specified Adaptation Layer
4606  * Indication parameter for all future INIT and INIT-ACK exchanges.
4607  */
4608 static int sctp_getsockopt_adaptation_layer(struct sock *sk, int len,
4609 				  char __user *optval, int __user *optlen)
4610 {
4611 	struct sctp_setadaptation adaptation;
4612 
4613 	if (len < sizeof(struct sctp_setadaptation))
4614 		return -EINVAL;
4615 
4616 	len = sizeof(struct sctp_setadaptation);
4617 
4618 	adaptation.ssb_adaptation_ind = sctp_sk(sk)->adaptation_ind;
4619 
4620 	if (put_user(len, optlen))
4621 		return -EFAULT;
4622 	if (copy_to_user(optval, &adaptation, len))
4623 		return -EFAULT;
4624 
4625 	return 0;
4626 }
4627 
4628 /*
4629  *
4630  * 7.1.14 Set default send parameters (SCTP_DEFAULT_SEND_PARAM)
4631  *
4632  *   Applications that wish to use the sendto() system call may wish to
4633  *   specify a default set of parameters that would normally be supplied
4634  *   through the inclusion of ancillary data.  This socket option allows
4635  *   such an application to set the default sctp_sndrcvinfo structure.
4636 
4637 
4638  *   The application that wishes to use this socket option simply passes
4639  *   in to this call the sctp_sndrcvinfo structure defined in Section
4640  *   5.2.2) The input parameters accepted by this call include
4641  *   sinfo_stream, sinfo_flags, sinfo_ppid, sinfo_context,
4642  *   sinfo_timetolive.  The user must provide the sinfo_assoc_id field in
4643  *   to this call if the caller is using the UDP model.
4644  *
4645  *   For getsockopt, it get the default sctp_sndrcvinfo structure.
4646  */
4647 static int sctp_getsockopt_default_send_param(struct sock *sk,
4648 					int len, char __user *optval,
4649 					int __user *optlen)
4650 {
4651 	struct sctp_sndrcvinfo info;
4652 	struct sctp_association *asoc;
4653 	struct sctp_sock *sp = sctp_sk(sk);
4654 
4655 	if (len < sizeof(struct sctp_sndrcvinfo))
4656 		return -EINVAL;
4657 
4658 	len = sizeof(struct sctp_sndrcvinfo);
4659 
4660 	if (copy_from_user(&info, optval, len))
4661 		return -EFAULT;
4662 
4663 	asoc = sctp_id2assoc(sk, info.sinfo_assoc_id);
4664 	if (!asoc && info.sinfo_assoc_id && sctp_style(sk, UDP))
4665 		return -EINVAL;
4666 
4667 	if (asoc) {
4668 		info.sinfo_stream = asoc->default_stream;
4669 		info.sinfo_flags = asoc->default_flags;
4670 		info.sinfo_ppid = asoc->default_ppid;
4671 		info.sinfo_context = asoc->default_context;
4672 		info.sinfo_timetolive = asoc->default_timetolive;
4673 	} else {
4674 		info.sinfo_stream = sp->default_stream;
4675 		info.sinfo_flags = sp->default_flags;
4676 		info.sinfo_ppid = sp->default_ppid;
4677 		info.sinfo_context = sp->default_context;
4678 		info.sinfo_timetolive = sp->default_timetolive;
4679 	}
4680 
4681 	if (put_user(len, optlen))
4682 		return -EFAULT;
4683 	if (copy_to_user(optval, &info, len))
4684 		return -EFAULT;
4685 
4686 	return 0;
4687 }
4688 
4689 /*
4690  *
4691  * 7.1.5 SCTP_NODELAY
4692  *
4693  * Turn on/off any Nagle-like algorithm.  This means that packets are
4694  * generally sent as soon as possible and no unnecessary delays are
4695  * introduced, at the cost of more packets in the network.  Expects an
4696  * integer boolean flag.
4697  */
4698 
4699 static int sctp_getsockopt_nodelay(struct sock *sk, int len,
4700 				   char __user *optval, int __user *optlen)
4701 {
4702 	int val;
4703 
4704 	if (len < sizeof(int))
4705 		return -EINVAL;
4706 
4707 	len = sizeof(int);
4708 	val = (sctp_sk(sk)->nodelay == 1);
4709 	if (put_user(len, optlen))
4710 		return -EFAULT;
4711 	if (copy_to_user(optval, &val, len))
4712 		return -EFAULT;
4713 	return 0;
4714 }
4715 
4716 /*
4717  *
4718  * 7.1.1 SCTP_RTOINFO
4719  *
4720  * The protocol parameters used to initialize and bound retransmission
4721  * timeout (RTO) are tunable. sctp_rtoinfo structure is used to access
4722  * and modify these parameters.
4723  * All parameters are time values, in milliseconds.  A value of 0, when
4724  * modifying the parameters, indicates that the current value should not
4725  * be changed.
4726  *
4727  */
4728 static int sctp_getsockopt_rtoinfo(struct sock *sk, int len,
4729 				char __user *optval,
4730 				int __user *optlen) {
4731 	struct sctp_rtoinfo rtoinfo;
4732 	struct sctp_association *asoc;
4733 
4734 	if (len < sizeof (struct sctp_rtoinfo))
4735 		return -EINVAL;
4736 
4737 	len = sizeof(struct sctp_rtoinfo);
4738 
4739 	if (copy_from_user(&rtoinfo, optval, len))
4740 		return -EFAULT;
4741 
4742 	asoc = sctp_id2assoc(sk, rtoinfo.srto_assoc_id);
4743 
4744 	if (!asoc && rtoinfo.srto_assoc_id && sctp_style(sk, UDP))
4745 		return -EINVAL;
4746 
4747 	/* Values corresponding to the specific association. */
4748 	if (asoc) {
4749 		rtoinfo.srto_initial = jiffies_to_msecs(asoc->rto_initial);
4750 		rtoinfo.srto_max = jiffies_to_msecs(asoc->rto_max);
4751 		rtoinfo.srto_min = jiffies_to_msecs(asoc->rto_min);
4752 	} else {
4753 		/* Values corresponding to the endpoint. */
4754 		struct sctp_sock *sp = sctp_sk(sk);
4755 
4756 		rtoinfo.srto_initial = sp->rtoinfo.srto_initial;
4757 		rtoinfo.srto_max = sp->rtoinfo.srto_max;
4758 		rtoinfo.srto_min = sp->rtoinfo.srto_min;
4759 	}
4760 
4761 	if (put_user(len, optlen))
4762 		return -EFAULT;
4763 
4764 	if (copy_to_user(optval, &rtoinfo, len))
4765 		return -EFAULT;
4766 
4767 	return 0;
4768 }
4769 
4770 /*
4771  *
4772  * 7.1.2 SCTP_ASSOCINFO
4773  *
4774  * This option is used to tune the maximum retransmission attempts
4775  * of the association.
4776  * Returns an error if the new association retransmission value is
4777  * greater than the sum of the retransmission value  of the peer.
4778  * See [SCTP] for more information.
4779  *
4780  */
4781 static int sctp_getsockopt_associnfo(struct sock *sk, int len,
4782 				     char __user *optval,
4783 				     int __user *optlen)
4784 {
4785 
4786 	struct sctp_assocparams assocparams;
4787 	struct sctp_association *asoc;
4788 	struct list_head *pos;
4789 	int cnt = 0;
4790 
4791 	if (len < sizeof (struct sctp_assocparams))
4792 		return -EINVAL;
4793 
4794 	len = sizeof(struct sctp_assocparams);
4795 
4796 	if (copy_from_user(&assocparams, optval, len))
4797 		return -EFAULT;
4798 
4799 	asoc = sctp_id2assoc(sk, assocparams.sasoc_assoc_id);
4800 
4801 	if (!asoc && assocparams.sasoc_assoc_id && sctp_style(sk, UDP))
4802 		return -EINVAL;
4803 
4804 	/* Values correspoinding to the specific association */
4805 	if (asoc) {
4806 		assocparams.sasoc_asocmaxrxt = asoc->max_retrans;
4807 		assocparams.sasoc_peer_rwnd = asoc->peer.rwnd;
4808 		assocparams.sasoc_local_rwnd = asoc->a_rwnd;
4809 		assocparams.sasoc_cookie_life = (asoc->cookie_life.tv_sec
4810 						* 1000) +
4811 						(asoc->cookie_life.tv_usec
4812 						/ 1000);
4813 
4814 		list_for_each(pos, &asoc->peer.transport_addr_list) {
4815 			cnt ++;
4816 		}
4817 
4818 		assocparams.sasoc_number_peer_destinations = cnt;
4819 	} else {
4820 		/* Values corresponding to the endpoint */
4821 		struct sctp_sock *sp = sctp_sk(sk);
4822 
4823 		assocparams.sasoc_asocmaxrxt = sp->assocparams.sasoc_asocmaxrxt;
4824 		assocparams.sasoc_peer_rwnd = sp->assocparams.sasoc_peer_rwnd;
4825 		assocparams.sasoc_local_rwnd = sp->assocparams.sasoc_local_rwnd;
4826 		assocparams.sasoc_cookie_life =
4827 					sp->assocparams.sasoc_cookie_life;
4828 		assocparams.sasoc_number_peer_destinations =
4829 					sp->assocparams.
4830 					sasoc_number_peer_destinations;
4831 	}
4832 
4833 	if (put_user(len, optlen))
4834 		return -EFAULT;
4835 
4836 	if (copy_to_user(optval, &assocparams, len))
4837 		return -EFAULT;
4838 
4839 	return 0;
4840 }
4841 
4842 /*
4843  * 7.1.16 Set/clear IPv4 mapped addresses (SCTP_I_WANT_MAPPED_V4_ADDR)
4844  *
4845  * This socket option is a boolean flag which turns on or off mapped V4
4846  * addresses.  If this option is turned on and the socket is type
4847  * PF_INET6, then IPv4 addresses will be mapped to V6 representation.
4848  * If this option is turned off, then no mapping will be done of V4
4849  * addresses and a user will receive both PF_INET6 and PF_INET type
4850  * addresses on the socket.
4851  */
4852 static int sctp_getsockopt_mappedv4(struct sock *sk, int len,
4853 				    char __user *optval, int __user *optlen)
4854 {
4855 	int val;
4856 	struct sctp_sock *sp = sctp_sk(sk);
4857 
4858 	if (len < sizeof(int))
4859 		return -EINVAL;
4860 
4861 	len = sizeof(int);
4862 	val = sp->v4mapped;
4863 	if (put_user(len, optlen))
4864 		return -EFAULT;
4865 	if (copy_to_user(optval, &val, len))
4866 		return -EFAULT;
4867 
4868 	return 0;
4869 }
4870 
4871 /*
4872  * 7.1.29.  Set or Get the default context (SCTP_CONTEXT)
4873  * (chapter and verse is quoted at sctp_setsockopt_context())
4874  */
4875 static int sctp_getsockopt_context(struct sock *sk, int len,
4876 				   char __user *optval, int __user *optlen)
4877 {
4878 	struct sctp_assoc_value params;
4879 	struct sctp_sock *sp;
4880 	struct sctp_association *asoc;
4881 
4882 	if (len < sizeof(struct sctp_assoc_value))
4883 		return -EINVAL;
4884 
4885 	len = sizeof(struct sctp_assoc_value);
4886 
4887 	if (copy_from_user(&params, optval, len))
4888 		return -EFAULT;
4889 
4890 	sp = sctp_sk(sk);
4891 
4892 	if (params.assoc_id != 0) {
4893 		asoc = sctp_id2assoc(sk, params.assoc_id);
4894 		if (!asoc)
4895 			return -EINVAL;
4896 		params.assoc_value = asoc->default_rcv_context;
4897 	} else {
4898 		params.assoc_value = sp->default_rcv_context;
4899 	}
4900 
4901 	if (put_user(len, optlen))
4902 		return -EFAULT;
4903 	if (copy_to_user(optval, &params, len))
4904 		return -EFAULT;
4905 
4906 	return 0;
4907 }
4908 
4909 /*
4910  * 8.1.16.  Get or Set the Maximum Fragmentation Size (SCTP_MAXSEG)
4911  * This option will get or set the maximum size to put in any outgoing
4912  * SCTP DATA chunk.  If a message is larger than this size it will be
4913  * fragmented by SCTP into the specified size.  Note that the underlying
4914  * SCTP implementation may fragment into smaller sized chunks when the
4915  * PMTU of the underlying association is smaller than the value set by
4916  * the user.  The default value for this option is '0' which indicates
4917  * the user is NOT limiting fragmentation and only the PMTU will effect
4918  * SCTP's choice of DATA chunk size.  Note also that values set larger
4919  * than the maximum size of an IP datagram will effectively let SCTP
4920  * control fragmentation (i.e. the same as setting this option to 0).
4921  *
4922  * The following structure is used to access and modify this parameter:
4923  *
4924  * struct sctp_assoc_value {
4925  *   sctp_assoc_t assoc_id;
4926  *   uint32_t assoc_value;
4927  * };
4928  *
4929  * assoc_id:  This parameter is ignored for one-to-one style sockets.
4930  *    For one-to-many style sockets this parameter indicates which
4931  *    association the user is performing an action upon.  Note that if
4932  *    this field's value is zero then the endpoints default value is
4933  *    changed (effecting future associations only).
4934  * assoc_value:  This parameter specifies the maximum size in bytes.
4935  */
4936 static int sctp_getsockopt_maxseg(struct sock *sk, int len,
4937 				  char __user *optval, int __user *optlen)
4938 {
4939 	struct sctp_assoc_value params;
4940 	struct sctp_association *asoc;
4941 
4942 	if (len == sizeof(int)) {
4943 		printk(KERN_WARNING
4944 		   "SCTP: Use of int in maxseg socket option deprecated\n");
4945 		printk(KERN_WARNING
4946 		   "SCTP: Use struct sctp_assoc_value instead\n");
4947 		params.assoc_id = 0;
4948 	} else if (len >= sizeof(struct sctp_assoc_value)) {
4949 		len = sizeof(struct sctp_assoc_value);
4950 		if (copy_from_user(&params, optval, sizeof(params)))
4951 			return -EFAULT;
4952 	} else
4953 		return -EINVAL;
4954 
4955 	asoc = sctp_id2assoc(sk, params.assoc_id);
4956 	if (!asoc && params.assoc_id && sctp_style(sk, UDP))
4957 		return -EINVAL;
4958 
4959 	if (asoc)
4960 		params.assoc_value = asoc->frag_point;
4961 	else
4962 		params.assoc_value = sctp_sk(sk)->user_frag;
4963 
4964 	if (put_user(len, optlen))
4965 		return -EFAULT;
4966 	if (len == sizeof(int)) {
4967 		if (copy_to_user(optval, &params.assoc_value, len))
4968 			return -EFAULT;
4969 	} else {
4970 		if (copy_to_user(optval, &params, len))
4971 			return -EFAULT;
4972 	}
4973 
4974 	return 0;
4975 }
4976 
4977 /*
4978  * 7.1.24.  Get or set fragmented interleave (SCTP_FRAGMENT_INTERLEAVE)
4979  * (chapter and verse is quoted at sctp_setsockopt_fragment_interleave())
4980  */
4981 static int sctp_getsockopt_fragment_interleave(struct sock *sk, int len,
4982 					       char __user *optval, int __user *optlen)
4983 {
4984 	int val;
4985 
4986 	if (len < sizeof(int))
4987 		return -EINVAL;
4988 
4989 	len = sizeof(int);
4990 
4991 	val = sctp_sk(sk)->frag_interleave;
4992 	if (put_user(len, optlen))
4993 		return -EFAULT;
4994 	if (copy_to_user(optval, &val, len))
4995 		return -EFAULT;
4996 
4997 	return 0;
4998 }
4999 
5000 /*
5001  * 7.1.25.  Set or Get the sctp partial delivery point
5002  * (chapter and verse is quoted at sctp_setsockopt_partial_delivery_point())
5003  */
5004 static int sctp_getsockopt_partial_delivery_point(struct sock *sk, int len,
5005 						  char __user *optval,
5006 						  int __user *optlen)
5007 {
5008 	u32 val;
5009 
5010 	if (len < sizeof(u32))
5011 		return -EINVAL;
5012 
5013 	len = sizeof(u32);
5014 
5015 	val = sctp_sk(sk)->pd_point;
5016 	if (put_user(len, optlen))
5017 		return -EFAULT;
5018 	if (copy_to_user(optval, &val, len))
5019 		return -EFAULT;
5020 
5021 	return -ENOTSUPP;
5022 }
5023 
5024 /*
5025  * 7.1.28.  Set or Get the maximum burst (SCTP_MAX_BURST)
5026  * (chapter and verse is quoted at sctp_setsockopt_maxburst())
5027  */
5028 static int sctp_getsockopt_maxburst(struct sock *sk, int len,
5029 				    char __user *optval,
5030 				    int __user *optlen)
5031 {
5032 	struct sctp_assoc_value params;
5033 	struct sctp_sock *sp;
5034 	struct sctp_association *asoc;
5035 
5036 	if (len == sizeof(int)) {
5037 		printk(KERN_WARNING
5038 		   "SCTP: Use of int in max_burst socket option deprecated\n");
5039 		printk(KERN_WARNING
5040 		   "SCTP: Use struct sctp_assoc_value instead\n");
5041 		params.assoc_id = 0;
5042 	} else if (len >= sizeof(struct sctp_assoc_value)) {
5043 		len = sizeof(struct sctp_assoc_value);
5044 		if (copy_from_user(&params, optval, len))
5045 			return -EFAULT;
5046 	} else
5047 		return -EINVAL;
5048 
5049 	sp = sctp_sk(sk);
5050 
5051 	if (params.assoc_id != 0) {
5052 		asoc = sctp_id2assoc(sk, params.assoc_id);
5053 		if (!asoc)
5054 			return -EINVAL;
5055 		params.assoc_value = asoc->max_burst;
5056 	} else
5057 		params.assoc_value = sp->max_burst;
5058 
5059 	if (len == sizeof(int)) {
5060 		if (copy_to_user(optval, &params.assoc_value, len))
5061 			return -EFAULT;
5062 	} else {
5063 		if (copy_to_user(optval, &params, len))
5064 			return -EFAULT;
5065 	}
5066 
5067 	return 0;
5068 
5069 }
5070 
5071 static int sctp_getsockopt_hmac_ident(struct sock *sk, int len,
5072 				    char __user *optval, int __user *optlen)
5073 {
5074 	struct sctp_hmacalgo  __user *p = (void __user *)optval;
5075 	struct sctp_hmac_algo_param *hmacs;
5076 	__u16 data_len = 0;
5077 	u32 num_idents;
5078 
5079 	if (!sctp_auth_enable)
5080 		return -EACCES;
5081 
5082 	hmacs = sctp_sk(sk)->ep->auth_hmacs_list;
5083 	data_len = ntohs(hmacs->param_hdr.length) - sizeof(sctp_paramhdr_t);
5084 
5085 	if (len < sizeof(struct sctp_hmacalgo) + data_len)
5086 		return -EINVAL;
5087 
5088 	len = sizeof(struct sctp_hmacalgo) + data_len;
5089 	num_idents = data_len / sizeof(u16);
5090 
5091 	if (put_user(len, optlen))
5092 		return -EFAULT;
5093 	if (put_user(num_idents, &p->shmac_num_idents))
5094 		return -EFAULT;
5095 	if (copy_to_user(p->shmac_idents, hmacs->hmac_ids, data_len))
5096 		return -EFAULT;
5097 	return 0;
5098 }
5099 
5100 static int sctp_getsockopt_active_key(struct sock *sk, int len,
5101 				    char __user *optval, int __user *optlen)
5102 {
5103 	struct sctp_authkeyid val;
5104 	struct sctp_association *asoc;
5105 
5106 	if (!sctp_auth_enable)
5107 		return -EACCES;
5108 
5109 	if (len < sizeof(struct sctp_authkeyid))
5110 		return -EINVAL;
5111 	if (copy_from_user(&val, optval, sizeof(struct sctp_authkeyid)))
5112 		return -EFAULT;
5113 
5114 	asoc = sctp_id2assoc(sk, val.scact_assoc_id);
5115 	if (!asoc && val.scact_assoc_id && sctp_style(sk, UDP))
5116 		return -EINVAL;
5117 
5118 	if (asoc)
5119 		val.scact_keynumber = asoc->active_key_id;
5120 	else
5121 		val.scact_keynumber = sctp_sk(sk)->ep->active_key_id;
5122 
5123 	len = sizeof(struct sctp_authkeyid);
5124 	if (put_user(len, optlen))
5125 		return -EFAULT;
5126 	if (copy_to_user(optval, &val, len))
5127 		return -EFAULT;
5128 
5129 	return 0;
5130 }
5131 
5132 static int sctp_getsockopt_peer_auth_chunks(struct sock *sk, int len,
5133 				    char __user *optval, int __user *optlen)
5134 {
5135 	struct sctp_authchunks __user *p = (void __user *)optval;
5136 	struct sctp_authchunks val;
5137 	struct sctp_association *asoc;
5138 	struct sctp_chunks_param *ch;
5139 	u32    num_chunks = 0;
5140 	char __user *to;
5141 
5142 	if (!sctp_auth_enable)
5143 		return -EACCES;
5144 
5145 	if (len < sizeof(struct sctp_authchunks))
5146 		return -EINVAL;
5147 
5148 	if (copy_from_user(&val, optval, sizeof(struct sctp_authchunks)))
5149 		return -EFAULT;
5150 
5151 	to = p->gauth_chunks;
5152 	asoc = sctp_id2assoc(sk, val.gauth_assoc_id);
5153 	if (!asoc)
5154 		return -EINVAL;
5155 
5156 	ch = asoc->peer.peer_chunks;
5157 	if (!ch)
5158 		goto num;
5159 
5160 	/* See if the user provided enough room for all the data */
5161 	num_chunks = ntohs(ch->param_hdr.length) - sizeof(sctp_paramhdr_t);
5162 	if (len < num_chunks)
5163 		return -EINVAL;
5164 
5165 	if (copy_to_user(to, ch->chunks, num_chunks))
5166 		return -EFAULT;
5167 num:
5168 	len = sizeof(struct sctp_authchunks) + num_chunks;
5169 	if (put_user(len, optlen)) return -EFAULT;
5170 	if (put_user(num_chunks, &p->gauth_number_of_chunks))
5171 		return -EFAULT;
5172 	return 0;
5173 }
5174 
5175 static int sctp_getsockopt_local_auth_chunks(struct sock *sk, int len,
5176 				    char __user *optval, int __user *optlen)
5177 {
5178 	struct sctp_authchunks __user *p = (void __user *)optval;
5179 	struct sctp_authchunks val;
5180 	struct sctp_association *asoc;
5181 	struct sctp_chunks_param *ch;
5182 	u32    num_chunks = 0;
5183 	char __user *to;
5184 
5185 	if (!sctp_auth_enable)
5186 		return -EACCES;
5187 
5188 	if (len < sizeof(struct sctp_authchunks))
5189 		return -EINVAL;
5190 
5191 	if (copy_from_user(&val, optval, sizeof(struct sctp_authchunks)))
5192 		return -EFAULT;
5193 
5194 	to = p->gauth_chunks;
5195 	asoc = sctp_id2assoc(sk, val.gauth_assoc_id);
5196 	if (!asoc && val.gauth_assoc_id && sctp_style(sk, UDP))
5197 		return -EINVAL;
5198 
5199 	if (asoc)
5200 		ch = (struct sctp_chunks_param*)asoc->c.auth_chunks;
5201 	else
5202 		ch = sctp_sk(sk)->ep->auth_chunk_list;
5203 
5204 	if (!ch)
5205 		goto num;
5206 
5207 	num_chunks = ntohs(ch->param_hdr.length) - sizeof(sctp_paramhdr_t);
5208 	if (len < sizeof(struct sctp_authchunks) + num_chunks)
5209 		return -EINVAL;
5210 
5211 	if (copy_to_user(to, ch->chunks, num_chunks))
5212 		return -EFAULT;
5213 num:
5214 	len = sizeof(struct sctp_authchunks) + num_chunks;
5215 	if (put_user(len, optlen))
5216 		return -EFAULT;
5217 	if (put_user(num_chunks, &p->gauth_number_of_chunks))
5218 		return -EFAULT;
5219 
5220 	return 0;
5221 }
5222 
5223 /*
5224  * 8.2.5.  Get the Current Number of Associations (SCTP_GET_ASSOC_NUMBER)
5225  * This option gets the current number of associations that are attached
5226  * to a one-to-many style socket.  The option value is an uint32_t.
5227  */
5228 static int sctp_getsockopt_assoc_number(struct sock *sk, int len,
5229 				    char __user *optval, int __user *optlen)
5230 {
5231 	struct sctp_sock *sp = sctp_sk(sk);
5232 	struct sctp_association *asoc;
5233 	u32 val = 0;
5234 
5235 	if (sctp_style(sk, TCP))
5236 		return -EOPNOTSUPP;
5237 
5238 	if (len < sizeof(u32))
5239 		return -EINVAL;
5240 
5241 	len = sizeof(u32);
5242 
5243 	list_for_each_entry(asoc, &(sp->ep->asocs), asocs) {
5244 		val++;
5245 	}
5246 
5247 	if (put_user(len, optlen))
5248 		return -EFAULT;
5249 	if (copy_to_user(optval, &val, len))
5250 		return -EFAULT;
5251 
5252 	return 0;
5253 }
5254 
5255 SCTP_STATIC int sctp_getsockopt(struct sock *sk, int level, int optname,
5256 				char __user *optval, int __user *optlen)
5257 {
5258 	int retval = 0;
5259 	int len;
5260 
5261 	SCTP_DEBUG_PRINTK("sctp_getsockopt(sk: %p... optname: %d)\n",
5262 			  sk, optname);
5263 
5264 	/* I can hardly begin to describe how wrong this is.  This is
5265 	 * so broken as to be worse than useless.  The API draft
5266 	 * REALLY is NOT helpful here...  I am not convinced that the
5267 	 * semantics of getsockopt() with a level OTHER THAN SOL_SCTP
5268 	 * are at all well-founded.
5269 	 */
5270 	if (level != SOL_SCTP) {
5271 		struct sctp_af *af = sctp_sk(sk)->pf->af;
5272 
5273 		retval = af->getsockopt(sk, level, optname, optval, optlen);
5274 		return retval;
5275 	}
5276 
5277 	if (get_user(len, optlen))
5278 		return -EFAULT;
5279 
5280 	sctp_lock_sock(sk);
5281 
5282 	switch (optname) {
5283 	case SCTP_STATUS:
5284 		retval = sctp_getsockopt_sctp_status(sk, len, optval, optlen);
5285 		break;
5286 	case SCTP_DISABLE_FRAGMENTS:
5287 		retval = sctp_getsockopt_disable_fragments(sk, len, optval,
5288 							   optlen);
5289 		break;
5290 	case SCTP_EVENTS:
5291 		retval = sctp_getsockopt_events(sk, len, optval, optlen);
5292 		break;
5293 	case SCTP_AUTOCLOSE:
5294 		retval = sctp_getsockopt_autoclose(sk, len, optval, optlen);
5295 		break;
5296 	case SCTP_SOCKOPT_PEELOFF:
5297 		retval = sctp_getsockopt_peeloff(sk, len, optval, optlen);
5298 		break;
5299 	case SCTP_PEER_ADDR_PARAMS:
5300 		retval = sctp_getsockopt_peer_addr_params(sk, len, optval,
5301 							  optlen);
5302 		break;
5303 	case SCTP_DELAYED_ACK:
5304 		retval = sctp_getsockopt_delayed_ack(sk, len, optval,
5305 							  optlen);
5306 		break;
5307 	case SCTP_INITMSG:
5308 		retval = sctp_getsockopt_initmsg(sk, len, optval, optlen);
5309 		break;
5310 	case SCTP_GET_PEER_ADDRS:
5311 		retval = sctp_getsockopt_peer_addrs(sk, len, optval,
5312 						    optlen);
5313 		break;
5314 	case SCTP_GET_LOCAL_ADDRS:
5315 		retval = sctp_getsockopt_local_addrs(sk, len, optval,
5316 						     optlen);
5317 		break;
5318 	case SCTP_SOCKOPT_CONNECTX3:
5319 		retval = sctp_getsockopt_connectx3(sk, len, optval, optlen);
5320 		break;
5321 	case SCTP_DEFAULT_SEND_PARAM:
5322 		retval = sctp_getsockopt_default_send_param(sk, len,
5323 							    optval, optlen);
5324 		break;
5325 	case SCTP_PRIMARY_ADDR:
5326 		retval = sctp_getsockopt_primary_addr(sk, len, optval, optlen);
5327 		break;
5328 	case SCTP_NODELAY:
5329 		retval = sctp_getsockopt_nodelay(sk, len, optval, optlen);
5330 		break;
5331 	case SCTP_RTOINFO:
5332 		retval = sctp_getsockopt_rtoinfo(sk, len, optval, optlen);
5333 		break;
5334 	case SCTP_ASSOCINFO:
5335 		retval = sctp_getsockopt_associnfo(sk, len, optval, optlen);
5336 		break;
5337 	case SCTP_I_WANT_MAPPED_V4_ADDR:
5338 		retval = sctp_getsockopt_mappedv4(sk, len, optval, optlen);
5339 		break;
5340 	case SCTP_MAXSEG:
5341 		retval = sctp_getsockopt_maxseg(sk, len, optval, optlen);
5342 		break;
5343 	case SCTP_GET_PEER_ADDR_INFO:
5344 		retval = sctp_getsockopt_peer_addr_info(sk, len, optval,
5345 							optlen);
5346 		break;
5347 	case SCTP_ADAPTATION_LAYER:
5348 		retval = sctp_getsockopt_adaptation_layer(sk, len, optval,
5349 							optlen);
5350 		break;
5351 	case SCTP_CONTEXT:
5352 		retval = sctp_getsockopt_context(sk, len, optval, optlen);
5353 		break;
5354 	case SCTP_FRAGMENT_INTERLEAVE:
5355 		retval = sctp_getsockopt_fragment_interleave(sk, len, optval,
5356 							     optlen);
5357 		break;
5358 	case SCTP_PARTIAL_DELIVERY_POINT:
5359 		retval = sctp_getsockopt_partial_delivery_point(sk, len, optval,
5360 								optlen);
5361 		break;
5362 	case SCTP_MAX_BURST:
5363 		retval = sctp_getsockopt_maxburst(sk, len, optval, optlen);
5364 		break;
5365 	case SCTP_AUTH_KEY:
5366 	case SCTP_AUTH_CHUNK:
5367 	case SCTP_AUTH_DELETE_KEY:
5368 		retval = -EOPNOTSUPP;
5369 		break;
5370 	case SCTP_HMAC_IDENT:
5371 		retval = sctp_getsockopt_hmac_ident(sk, len, optval, optlen);
5372 		break;
5373 	case SCTP_AUTH_ACTIVE_KEY:
5374 		retval = sctp_getsockopt_active_key(sk, len, optval, optlen);
5375 		break;
5376 	case SCTP_PEER_AUTH_CHUNKS:
5377 		retval = sctp_getsockopt_peer_auth_chunks(sk, len, optval,
5378 							optlen);
5379 		break;
5380 	case SCTP_LOCAL_AUTH_CHUNKS:
5381 		retval = sctp_getsockopt_local_auth_chunks(sk, len, optval,
5382 							optlen);
5383 		break;
5384 	case SCTP_GET_ASSOC_NUMBER:
5385 		retval = sctp_getsockopt_assoc_number(sk, len, optval, optlen);
5386 		break;
5387 	default:
5388 		retval = -ENOPROTOOPT;
5389 		break;
5390 	}
5391 
5392 	sctp_release_sock(sk);
5393 	return retval;
5394 }
5395 
5396 static void sctp_hash(struct sock *sk)
5397 {
5398 	/* STUB */
5399 }
5400 
5401 static void sctp_unhash(struct sock *sk)
5402 {
5403 	/* STUB */
5404 }
5405 
5406 /* Check if port is acceptable.  Possibly find first available port.
5407  *
5408  * The port hash table (contained in the 'global' SCTP protocol storage
5409  * returned by struct sctp_protocol *sctp_get_protocol()). The hash
5410  * table is an array of 4096 lists (sctp_bind_hashbucket). Each
5411  * list (the list number is the port number hashed out, so as you
5412  * would expect from a hash function, all the ports in a given list have
5413  * such a number that hashes out to the same list number; you were
5414  * expecting that, right?); so each list has a set of ports, with a
5415  * link to the socket (struct sock) that uses it, the port number and
5416  * a fastreuse flag (FIXME: NPI ipg).
5417  */
5418 static struct sctp_bind_bucket *sctp_bucket_create(
5419 	struct sctp_bind_hashbucket *head, unsigned short snum);
5420 
5421 static long sctp_get_port_local(struct sock *sk, union sctp_addr *addr)
5422 {
5423 	struct sctp_bind_hashbucket *head; /* hash list */
5424 	struct sctp_bind_bucket *pp; /* hash list port iterator */
5425 	struct hlist_node *node;
5426 	unsigned short snum;
5427 	int ret;
5428 
5429 	snum = ntohs(addr->v4.sin_port);
5430 
5431 	SCTP_DEBUG_PRINTK("sctp_get_port() begins, snum=%d\n", snum);
5432 	sctp_local_bh_disable();
5433 
5434 	if (snum == 0) {
5435 		/* Search for an available port. */
5436 		int low, high, remaining, index;
5437 		unsigned int rover;
5438 
5439 		inet_get_local_port_range(&low, &high);
5440 		remaining = (high - low) + 1;
5441 		rover = net_random() % remaining + low;
5442 
5443 		do {
5444 			rover++;
5445 			if ((rover < low) || (rover > high))
5446 				rover = low;
5447 			if (inet_is_reserved_local_port(rover))
5448 				continue;
5449 			index = sctp_phashfn(rover);
5450 			head = &sctp_port_hashtable[index];
5451 			sctp_spin_lock(&head->lock);
5452 			sctp_for_each_hentry(pp, node, &head->chain)
5453 				if (pp->port == rover)
5454 					goto next;
5455 			break;
5456 		next:
5457 			sctp_spin_unlock(&head->lock);
5458 		} while (--remaining > 0);
5459 
5460 		/* Exhausted local port range during search? */
5461 		ret = 1;
5462 		if (remaining <= 0)
5463 			goto fail;
5464 
5465 		/* OK, here is the one we will use.  HEAD (the port
5466 		 * hash table list entry) is non-NULL and we hold it's
5467 		 * mutex.
5468 		 */
5469 		snum = rover;
5470 	} else {
5471 		/* We are given an specific port number; we verify
5472 		 * that it is not being used. If it is used, we will
5473 		 * exahust the search in the hash list corresponding
5474 		 * to the port number (snum) - we detect that with the
5475 		 * port iterator, pp being NULL.
5476 		 */
5477 		head = &sctp_port_hashtable[sctp_phashfn(snum)];
5478 		sctp_spin_lock(&head->lock);
5479 		sctp_for_each_hentry(pp, node, &head->chain) {
5480 			if (pp->port == snum)
5481 				goto pp_found;
5482 		}
5483 	}
5484 	pp = NULL;
5485 	goto pp_not_found;
5486 pp_found:
5487 	if (!hlist_empty(&pp->owner)) {
5488 		/* We had a port hash table hit - there is an
5489 		 * available port (pp != NULL) and it is being
5490 		 * used by other socket (pp->owner not empty); that other
5491 		 * socket is going to be sk2.
5492 		 */
5493 		int reuse = sk->sk_reuse;
5494 		struct sock *sk2;
5495 
5496 		SCTP_DEBUG_PRINTK("sctp_get_port() found a possible match\n");
5497 		if (pp->fastreuse && sk->sk_reuse &&
5498 			sk->sk_state != SCTP_SS_LISTENING)
5499 			goto success;
5500 
5501 		/* Run through the list of sockets bound to the port
5502 		 * (pp->port) [via the pointers bind_next and
5503 		 * bind_pprev in the struct sock *sk2 (pp->sk)]. On each one,
5504 		 * we get the endpoint they describe and run through
5505 		 * the endpoint's list of IP (v4 or v6) addresses,
5506 		 * comparing each of the addresses with the address of
5507 		 * the socket sk. If we find a match, then that means
5508 		 * that this port/socket (sk) combination are already
5509 		 * in an endpoint.
5510 		 */
5511 		sk_for_each_bound(sk2, node, &pp->owner) {
5512 			struct sctp_endpoint *ep2;
5513 			ep2 = sctp_sk(sk2)->ep;
5514 
5515 			if (sk == sk2 ||
5516 			    (reuse && sk2->sk_reuse &&
5517 			     sk2->sk_state != SCTP_SS_LISTENING))
5518 				continue;
5519 
5520 			if (sctp_bind_addr_conflict(&ep2->base.bind_addr, addr,
5521 						 sctp_sk(sk2), sctp_sk(sk))) {
5522 				ret = (long)sk2;
5523 				goto fail_unlock;
5524 			}
5525 		}
5526 		SCTP_DEBUG_PRINTK("sctp_get_port(): Found a match\n");
5527 	}
5528 pp_not_found:
5529 	/* If there was a hash table miss, create a new port.  */
5530 	ret = 1;
5531 	if (!pp && !(pp = sctp_bucket_create(head, snum)))
5532 		goto fail_unlock;
5533 
5534 	/* In either case (hit or miss), make sure fastreuse is 1 only
5535 	 * if sk->sk_reuse is too (that is, if the caller requested
5536 	 * SO_REUSEADDR on this socket -sk-).
5537 	 */
5538 	if (hlist_empty(&pp->owner)) {
5539 		if (sk->sk_reuse && sk->sk_state != SCTP_SS_LISTENING)
5540 			pp->fastreuse = 1;
5541 		else
5542 			pp->fastreuse = 0;
5543 	} else if (pp->fastreuse &&
5544 		(!sk->sk_reuse || sk->sk_state == SCTP_SS_LISTENING))
5545 		pp->fastreuse = 0;
5546 
5547 	/* We are set, so fill up all the data in the hash table
5548 	 * entry, tie the socket list information with the rest of the
5549 	 * sockets FIXME: Blurry, NPI (ipg).
5550 	 */
5551 success:
5552 	if (!sctp_sk(sk)->bind_hash) {
5553 		inet_sk(sk)->inet_num = snum;
5554 		sk_add_bind_node(sk, &pp->owner);
5555 		sctp_sk(sk)->bind_hash = pp;
5556 	}
5557 	ret = 0;
5558 
5559 fail_unlock:
5560 	sctp_spin_unlock(&head->lock);
5561 
5562 fail:
5563 	sctp_local_bh_enable();
5564 	return ret;
5565 }
5566 
5567 /* Assign a 'snum' port to the socket.  If snum == 0, an ephemeral
5568  * port is requested.
5569  */
5570 static int sctp_get_port(struct sock *sk, unsigned short snum)
5571 {
5572 	long ret;
5573 	union sctp_addr addr;
5574 	struct sctp_af *af = sctp_sk(sk)->pf->af;
5575 
5576 	/* Set up a dummy address struct from the sk. */
5577 	af->from_sk(&addr, sk);
5578 	addr.v4.sin_port = htons(snum);
5579 
5580 	/* Note: sk->sk_num gets filled in if ephemeral port request. */
5581 	ret = sctp_get_port_local(sk, &addr);
5582 
5583 	return (ret ? 1 : 0);
5584 }
5585 
5586 /*
5587  *  Move a socket to LISTENING state.
5588  */
5589 SCTP_STATIC int sctp_listen_start(struct sock *sk, int backlog)
5590 {
5591 	struct sctp_sock *sp = sctp_sk(sk);
5592 	struct sctp_endpoint *ep = sp->ep;
5593 	struct crypto_hash *tfm = NULL;
5594 
5595 	/* Allocate HMAC for generating cookie. */
5596 	if (!sctp_sk(sk)->hmac && sctp_hmac_alg) {
5597 		tfm = crypto_alloc_hash(sctp_hmac_alg, 0, CRYPTO_ALG_ASYNC);
5598 		if (IS_ERR(tfm)) {
5599 			if (net_ratelimit()) {
5600 				printk(KERN_INFO
5601 				       "SCTP: failed to load transform for %s: %ld\n",
5602 					sctp_hmac_alg, PTR_ERR(tfm));
5603 			}
5604 			return -ENOSYS;
5605 		}
5606 		sctp_sk(sk)->hmac = tfm;
5607 	}
5608 
5609 	/*
5610 	 * If a bind() or sctp_bindx() is not called prior to a listen()
5611 	 * call that allows new associations to be accepted, the system
5612 	 * picks an ephemeral port and will choose an address set equivalent
5613 	 * to binding with a wildcard address.
5614 	 *
5615 	 * This is not currently spelled out in the SCTP sockets
5616 	 * extensions draft, but follows the practice as seen in TCP
5617 	 * sockets.
5618 	 *
5619 	 */
5620 	sk->sk_state = SCTP_SS_LISTENING;
5621 	if (!ep->base.bind_addr.port) {
5622 		if (sctp_autobind(sk))
5623 			return -EAGAIN;
5624 	} else {
5625 		if (sctp_get_port(sk, inet_sk(sk)->inet_num)) {
5626 			sk->sk_state = SCTP_SS_CLOSED;
5627 			return -EADDRINUSE;
5628 		}
5629 	}
5630 
5631 	sk->sk_max_ack_backlog = backlog;
5632 	sctp_hash_endpoint(ep);
5633 	return 0;
5634 }
5635 
5636 /*
5637  * 4.1.3 / 5.1.3 listen()
5638  *
5639  *   By default, new associations are not accepted for UDP style sockets.
5640  *   An application uses listen() to mark a socket as being able to
5641  *   accept new associations.
5642  *
5643  *   On TCP style sockets, applications use listen() to ready the SCTP
5644  *   endpoint for accepting inbound associations.
5645  *
5646  *   On both types of endpoints a backlog of '0' disables listening.
5647  *
5648  *  Move a socket to LISTENING state.
5649  */
5650 int sctp_inet_listen(struct socket *sock, int backlog)
5651 {
5652 	struct sock *sk = sock->sk;
5653 	struct sctp_endpoint *ep = sctp_sk(sk)->ep;
5654 	int err = -EINVAL;
5655 
5656 	if (unlikely(backlog < 0))
5657 		return err;
5658 
5659 	sctp_lock_sock(sk);
5660 
5661 	/* Peeled-off sockets are not allowed to listen().  */
5662 	if (sctp_style(sk, UDP_HIGH_BANDWIDTH))
5663 		goto out;
5664 
5665 	if (sock->state != SS_UNCONNECTED)
5666 		goto out;
5667 
5668 	/* If backlog is zero, disable listening. */
5669 	if (!backlog) {
5670 		if (sctp_sstate(sk, CLOSED))
5671 			goto out;
5672 
5673 		err = 0;
5674 		sctp_unhash_endpoint(ep);
5675 		sk->sk_state = SCTP_SS_CLOSED;
5676 		if (sk->sk_reuse)
5677 			sctp_sk(sk)->bind_hash->fastreuse = 1;
5678 		goto out;
5679 	}
5680 
5681 	/* If we are already listening, just update the backlog */
5682 	if (sctp_sstate(sk, LISTENING))
5683 		sk->sk_max_ack_backlog = backlog;
5684 	else {
5685 		err = sctp_listen_start(sk, backlog);
5686 		if (err)
5687 			goto out;
5688 	}
5689 
5690 	err = 0;
5691 out:
5692 	sctp_release_sock(sk);
5693 	return err;
5694 }
5695 
5696 /*
5697  * This function is done by modeling the current datagram_poll() and the
5698  * tcp_poll().  Note that, based on these implementations, we don't
5699  * lock the socket in this function, even though it seems that,
5700  * ideally, locking or some other mechanisms can be used to ensure
5701  * the integrity of the counters (sndbuf and wmem_alloc) used
5702  * in this place.  We assume that we don't need locks either until proven
5703  * otherwise.
5704  *
5705  * Another thing to note is that we include the Async I/O support
5706  * here, again, by modeling the current TCP/UDP code.  We don't have
5707  * a good way to test with it yet.
5708  */
5709 unsigned int sctp_poll(struct file *file, struct socket *sock, poll_table *wait)
5710 {
5711 	struct sock *sk = sock->sk;
5712 	struct sctp_sock *sp = sctp_sk(sk);
5713 	unsigned int mask;
5714 
5715 	poll_wait(file, sk_sleep(sk), wait);
5716 
5717 	/* A TCP-style listening socket becomes readable when the accept queue
5718 	 * is not empty.
5719 	 */
5720 	if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
5721 		return (!list_empty(&sp->ep->asocs)) ?
5722 			(POLLIN | POLLRDNORM) : 0;
5723 
5724 	mask = 0;
5725 
5726 	/* Is there any exceptional events?  */
5727 	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
5728 		mask |= POLLERR;
5729 	if (sk->sk_shutdown & RCV_SHUTDOWN)
5730 		mask |= POLLRDHUP;
5731 	if (sk->sk_shutdown == SHUTDOWN_MASK)
5732 		mask |= POLLHUP;
5733 
5734 	/* Is it readable?  Reconsider this code with TCP-style support.  */
5735 	if (!skb_queue_empty(&sk->sk_receive_queue) ||
5736 	    (sk->sk_shutdown & RCV_SHUTDOWN))
5737 		mask |= POLLIN | POLLRDNORM;
5738 
5739 	/* The association is either gone or not ready.  */
5740 	if (!sctp_style(sk, UDP) && sctp_sstate(sk, CLOSED))
5741 		return mask;
5742 
5743 	/* Is it writable?  */
5744 	if (sctp_writeable(sk)) {
5745 		mask |= POLLOUT | POLLWRNORM;
5746 	} else {
5747 		set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
5748 		/*
5749 		 * Since the socket is not locked, the buffer
5750 		 * might be made available after the writeable check and
5751 		 * before the bit is set.  This could cause a lost I/O
5752 		 * signal.  tcp_poll() has a race breaker for this race
5753 		 * condition.  Based on their implementation, we put
5754 		 * in the following code to cover it as well.
5755 		 */
5756 		if (sctp_writeable(sk))
5757 			mask |= POLLOUT | POLLWRNORM;
5758 	}
5759 	return mask;
5760 }
5761 
5762 /********************************************************************
5763  * 2nd Level Abstractions
5764  ********************************************************************/
5765 
5766 static struct sctp_bind_bucket *sctp_bucket_create(
5767 	struct sctp_bind_hashbucket *head, unsigned short snum)
5768 {
5769 	struct sctp_bind_bucket *pp;
5770 
5771 	pp = kmem_cache_alloc(sctp_bucket_cachep, GFP_ATOMIC);
5772 	if (pp) {
5773 		SCTP_DBG_OBJCNT_INC(bind_bucket);
5774 		pp->port = snum;
5775 		pp->fastreuse = 0;
5776 		INIT_HLIST_HEAD(&pp->owner);
5777 		hlist_add_head(&pp->node, &head->chain);
5778 	}
5779 	return pp;
5780 }
5781 
5782 /* Caller must hold hashbucket lock for this tb with local BH disabled */
5783 static void sctp_bucket_destroy(struct sctp_bind_bucket *pp)
5784 {
5785 	if (pp && hlist_empty(&pp->owner)) {
5786 		__hlist_del(&pp->node);
5787 		kmem_cache_free(sctp_bucket_cachep, pp);
5788 		SCTP_DBG_OBJCNT_DEC(bind_bucket);
5789 	}
5790 }
5791 
5792 /* Release this socket's reference to a local port.  */
5793 static inline void __sctp_put_port(struct sock *sk)
5794 {
5795 	struct sctp_bind_hashbucket *head =
5796 		&sctp_port_hashtable[sctp_phashfn(inet_sk(sk)->inet_num)];
5797 	struct sctp_bind_bucket *pp;
5798 
5799 	sctp_spin_lock(&head->lock);
5800 	pp = sctp_sk(sk)->bind_hash;
5801 	__sk_del_bind_node(sk);
5802 	sctp_sk(sk)->bind_hash = NULL;
5803 	inet_sk(sk)->inet_num = 0;
5804 	sctp_bucket_destroy(pp);
5805 	sctp_spin_unlock(&head->lock);
5806 }
5807 
5808 void sctp_put_port(struct sock *sk)
5809 {
5810 	sctp_local_bh_disable();
5811 	__sctp_put_port(sk);
5812 	sctp_local_bh_enable();
5813 }
5814 
5815 /*
5816  * The system picks an ephemeral port and choose an address set equivalent
5817  * to binding with a wildcard address.
5818  * One of those addresses will be the primary address for the association.
5819  * This automatically enables the multihoming capability of SCTP.
5820  */
5821 static int sctp_autobind(struct sock *sk)
5822 {
5823 	union sctp_addr autoaddr;
5824 	struct sctp_af *af;
5825 	__be16 port;
5826 
5827 	/* Initialize a local sockaddr structure to INADDR_ANY. */
5828 	af = sctp_sk(sk)->pf->af;
5829 
5830 	port = htons(inet_sk(sk)->inet_num);
5831 	af->inaddr_any(&autoaddr, port);
5832 
5833 	return sctp_do_bind(sk, &autoaddr, af->sockaddr_len);
5834 }
5835 
5836 /* Parse out IPPROTO_SCTP CMSG headers.  Perform only minimal validation.
5837  *
5838  * From RFC 2292
5839  * 4.2 The cmsghdr Structure *
5840  *
5841  * When ancillary data is sent or received, any number of ancillary data
5842  * objects can be specified by the msg_control and msg_controllen members of
5843  * the msghdr structure, because each object is preceded by
5844  * a cmsghdr structure defining the object's length (the cmsg_len member).
5845  * Historically Berkeley-derived implementations have passed only one object
5846  * at a time, but this API allows multiple objects to be
5847  * passed in a single call to sendmsg() or recvmsg(). The following example
5848  * shows two ancillary data objects in a control buffer.
5849  *
5850  *   |<--------------------------- msg_controllen -------------------------->|
5851  *   |                                                                       |
5852  *
5853  *   |<----- ancillary data object ----->|<----- ancillary data object ----->|
5854  *
5855  *   |<---------- CMSG_SPACE() --------->|<---------- CMSG_SPACE() --------->|
5856  *   |                                   |                                   |
5857  *
5858  *   |<---------- cmsg_len ---------->|  |<--------- cmsg_len ----------->|  |
5859  *
5860  *   |<--------- CMSG_LEN() --------->|  |<-------- CMSG_LEN() ---------->|  |
5861  *   |                                |  |                                |  |
5862  *
5863  *   +-----+-----+-----+--+-----------+--+-----+-----+-----+--+-----------+--+
5864  *   |cmsg_|cmsg_|cmsg_|XX|           |XX|cmsg_|cmsg_|cmsg_|XX|           |XX|
5865  *
5866  *   |len  |level|type |XX|cmsg_data[]|XX|len  |level|type |XX|cmsg_data[]|XX|
5867  *
5868  *   +-----+-----+-----+--+-----------+--+-----+-----+-----+--+-----------+--+
5869  *    ^
5870  *    |
5871  *
5872  * msg_control
5873  * points here
5874  */
5875 SCTP_STATIC int sctp_msghdr_parse(const struct msghdr *msg,
5876 				  sctp_cmsgs_t *cmsgs)
5877 {
5878 	struct cmsghdr *cmsg;
5879 	struct msghdr *my_msg = (struct msghdr *)msg;
5880 
5881 	for (cmsg = CMSG_FIRSTHDR(msg);
5882 	     cmsg != NULL;
5883 	     cmsg = CMSG_NXTHDR(my_msg, cmsg)) {
5884 		if (!CMSG_OK(my_msg, cmsg))
5885 			return -EINVAL;
5886 
5887 		/* Should we parse this header or ignore?  */
5888 		if (cmsg->cmsg_level != IPPROTO_SCTP)
5889 			continue;
5890 
5891 		/* Strictly check lengths following example in SCM code.  */
5892 		switch (cmsg->cmsg_type) {
5893 		case SCTP_INIT:
5894 			/* SCTP Socket API Extension
5895 			 * 5.2.1 SCTP Initiation Structure (SCTP_INIT)
5896 			 *
5897 			 * This cmsghdr structure provides information for
5898 			 * initializing new SCTP associations with sendmsg().
5899 			 * The SCTP_INITMSG socket option uses this same data
5900 			 * structure.  This structure is not used for
5901 			 * recvmsg().
5902 			 *
5903 			 * cmsg_level    cmsg_type      cmsg_data[]
5904 			 * ------------  ------------   ----------------------
5905 			 * IPPROTO_SCTP  SCTP_INIT      struct sctp_initmsg
5906 			 */
5907 			if (cmsg->cmsg_len !=
5908 			    CMSG_LEN(sizeof(struct sctp_initmsg)))
5909 				return -EINVAL;
5910 			cmsgs->init = (struct sctp_initmsg *)CMSG_DATA(cmsg);
5911 			break;
5912 
5913 		case SCTP_SNDRCV:
5914 			/* SCTP Socket API Extension
5915 			 * 5.2.2 SCTP Header Information Structure(SCTP_SNDRCV)
5916 			 *
5917 			 * This cmsghdr structure specifies SCTP options for
5918 			 * sendmsg() and describes SCTP header information
5919 			 * about a received message through recvmsg().
5920 			 *
5921 			 * cmsg_level    cmsg_type      cmsg_data[]
5922 			 * ------------  ------------   ----------------------
5923 			 * IPPROTO_SCTP  SCTP_SNDRCV    struct sctp_sndrcvinfo
5924 			 */
5925 			if (cmsg->cmsg_len !=
5926 			    CMSG_LEN(sizeof(struct sctp_sndrcvinfo)))
5927 				return -EINVAL;
5928 
5929 			cmsgs->info =
5930 				(struct sctp_sndrcvinfo *)CMSG_DATA(cmsg);
5931 
5932 			/* Minimally, validate the sinfo_flags. */
5933 			if (cmsgs->info->sinfo_flags &
5934 			    ~(SCTP_UNORDERED | SCTP_ADDR_OVER |
5935 			      SCTP_ABORT | SCTP_EOF))
5936 				return -EINVAL;
5937 			break;
5938 
5939 		default:
5940 			return -EINVAL;
5941 		}
5942 	}
5943 	return 0;
5944 }
5945 
5946 /*
5947  * Wait for a packet..
5948  * Note: This function is the same function as in core/datagram.c
5949  * with a few modifications to make lksctp work.
5950  */
5951 static int sctp_wait_for_packet(struct sock * sk, int *err, long *timeo_p)
5952 {
5953 	int error;
5954 	DEFINE_WAIT(wait);
5955 
5956 	prepare_to_wait_exclusive(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
5957 
5958 	/* Socket errors? */
5959 	error = sock_error(sk);
5960 	if (error)
5961 		goto out;
5962 
5963 	if (!skb_queue_empty(&sk->sk_receive_queue))
5964 		goto ready;
5965 
5966 	/* Socket shut down?  */
5967 	if (sk->sk_shutdown & RCV_SHUTDOWN)
5968 		goto out;
5969 
5970 	/* Sequenced packets can come disconnected.  If so we report the
5971 	 * problem.
5972 	 */
5973 	error = -ENOTCONN;
5974 
5975 	/* Is there a good reason to think that we may receive some data?  */
5976 	if (list_empty(&sctp_sk(sk)->ep->asocs) && !sctp_sstate(sk, LISTENING))
5977 		goto out;
5978 
5979 	/* Handle signals.  */
5980 	if (signal_pending(current))
5981 		goto interrupted;
5982 
5983 	/* Let another process have a go.  Since we are going to sleep
5984 	 * anyway.  Note: This may cause odd behaviors if the message
5985 	 * does not fit in the user's buffer, but this seems to be the
5986 	 * only way to honor MSG_DONTWAIT realistically.
5987 	 */
5988 	sctp_release_sock(sk);
5989 	*timeo_p = schedule_timeout(*timeo_p);
5990 	sctp_lock_sock(sk);
5991 
5992 ready:
5993 	finish_wait(sk_sleep(sk), &wait);
5994 	return 0;
5995 
5996 interrupted:
5997 	error = sock_intr_errno(*timeo_p);
5998 
5999 out:
6000 	finish_wait(sk_sleep(sk), &wait);
6001 	*err = error;
6002 	return error;
6003 }
6004 
6005 /* Receive a datagram.
6006  * Note: This is pretty much the same routine as in core/datagram.c
6007  * with a few changes to make lksctp work.
6008  */
6009 static struct sk_buff *sctp_skb_recv_datagram(struct sock *sk, int flags,
6010 					      int noblock, int *err)
6011 {
6012 	int error;
6013 	struct sk_buff *skb;
6014 	long timeo;
6015 
6016 	timeo = sock_rcvtimeo(sk, noblock);
6017 
6018 	SCTP_DEBUG_PRINTK("Timeout: timeo: %ld, MAX: %ld.\n",
6019 			  timeo, MAX_SCHEDULE_TIMEOUT);
6020 
6021 	do {
6022 		/* Again only user level code calls this function,
6023 		 * so nothing interrupt level
6024 		 * will suddenly eat the receive_queue.
6025 		 *
6026 		 *  Look at current nfs client by the way...
6027 		 *  However, this function was corrent in any case. 8)
6028 		 */
6029 		if (flags & MSG_PEEK) {
6030 			spin_lock_bh(&sk->sk_receive_queue.lock);
6031 			skb = skb_peek(&sk->sk_receive_queue);
6032 			if (skb)
6033 				atomic_inc(&skb->users);
6034 			spin_unlock_bh(&sk->sk_receive_queue.lock);
6035 		} else {
6036 			skb = skb_dequeue(&sk->sk_receive_queue);
6037 		}
6038 
6039 		if (skb)
6040 			return skb;
6041 
6042 		/* Caller is allowed not to check sk->sk_err before calling. */
6043 		error = sock_error(sk);
6044 		if (error)
6045 			goto no_packet;
6046 
6047 		if (sk->sk_shutdown & RCV_SHUTDOWN)
6048 			break;
6049 
6050 		/* User doesn't want to wait.  */
6051 		error = -EAGAIN;
6052 		if (!timeo)
6053 			goto no_packet;
6054 	} while (sctp_wait_for_packet(sk, err, &timeo) == 0);
6055 
6056 	return NULL;
6057 
6058 no_packet:
6059 	*err = error;
6060 	return NULL;
6061 }
6062 
6063 /* If sndbuf has changed, wake up per association sndbuf waiters.  */
6064 static void __sctp_write_space(struct sctp_association *asoc)
6065 {
6066 	struct sock *sk = asoc->base.sk;
6067 	struct socket *sock = sk->sk_socket;
6068 
6069 	if ((sctp_wspace(asoc) > 0) && sock) {
6070 		if (waitqueue_active(&asoc->wait))
6071 			wake_up_interruptible(&asoc->wait);
6072 
6073 		if (sctp_writeable(sk)) {
6074 			if (sk_sleep(sk) && waitqueue_active(sk_sleep(sk)))
6075 				wake_up_interruptible(sk_sleep(sk));
6076 
6077 			/* Note that we try to include the Async I/O support
6078 			 * here by modeling from the current TCP/UDP code.
6079 			 * We have not tested with it yet.
6080 			 */
6081 			if (sock->wq->fasync_list &&
6082 			    !(sk->sk_shutdown & SEND_SHUTDOWN))
6083 				sock_wake_async(sock,
6084 						SOCK_WAKE_SPACE, POLL_OUT);
6085 		}
6086 	}
6087 }
6088 
6089 /* Do accounting for the sndbuf space.
6090  * Decrement the used sndbuf space of the corresponding association by the
6091  * data size which was just transmitted(freed).
6092  */
6093 static void sctp_wfree(struct sk_buff *skb)
6094 {
6095 	struct sctp_association *asoc;
6096 	struct sctp_chunk *chunk;
6097 	struct sock *sk;
6098 
6099 	/* Get the saved chunk pointer.  */
6100 	chunk = *((struct sctp_chunk **)(skb->cb));
6101 	asoc = chunk->asoc;
6102 	sk = asoc->base.sk;
6103 	asoc->sndbuf_used -= SCTP_DATA_SNDSIZE(chunk) +
6104 				sizeof(struct sk_buff) +
6105 				sizeof(struct sctp_chunk);
6106 
6107 	atomic_sub(sizeof(struct sctp_chunk), &sk->sk_wmem_alloc);
6108 
6109 	/*
6110 	 * This undoes what is done via sctp_set_owner_w and sk_mem_charge
6111 	 */
6112 	sk->sk_wmem_queued   -= skb->truesize;
6113 	sk_mem_uncharge(sk, skb->truesize);
6114 
6115 	sock_wfree(skb);
6116 	__sctp_write_space(asoc);
6117 
6118 	sctp_association_put(asoc);
6119 }
6120 
6121 /* Do accounting for the receive space on the socket.
6122  * Accounting for the association is done in ulpevent.c
6123  * We set this as a destructor for the cloned data skbs so that
6124  * accounting is done at the correct time.
6125  */
6126 void sctp_sock_rfree(struct sk_buff *skb)
6127 {
6128 	struct sock *sk = skb->sk;
6129 	struct sctp_ulpevent *event = sctp_skb2event(skb);
6130 
6131 	atomic_sub(event->rmem_len, &sk->sk_rmem_alloc);
6132 
6133 	/*
6134 	 * Mimic the behavior of sock_rfree
6135 	 */
6136 	sk_mem_uncharge(sk, event->rmem_len);
6137 }
6138 
6139 
6140 /* Helper function to wait for space in the sndbuf.  */
6141 static int sctp_wait_for_sndbuf(struct sctp_association *asoc, long *timeo_p,
6142 				size_t msg_len)
6143 {
6144 	struct sock *sk = asoc->base.sk;
6145 	int err = 0;
6146 	long current_timeo = *timeo_p;
6147 	DEFINE_WAIT(wait);
6148 
6149 	SCTP_DEBUG_PRINTK("wait_for_sndbuf: asoc=%p, timeo=%ld, msg_len=%zu\n",
6150 			  asoc, (long)(*timeo_p), msg_len);
6151 
6152 	/* Increment the association's refcnt.  */
6153 	sctp_association_hold(asoc);
6154 
6155 	/* Wait on the association specific sndbuf space. */
6156 	for (;;) {
6157 		prepare_to_wait_exclusive(&asoc->wait, &wait,
6158 					  TASK_INTERRUPTIBLE);
6159 		if (!*timeo_p)
6160 			goto do_nonblock;
6161 		if (sk->sk_err || asoc->state >= SCTP_STATE_SHUTDOWN_PENDING ||
6162 		    asoc->base.dead)
6163 			goto do_error;
6164 		if (signal_pending(current))
6165 			goto do_interrupted;
6166 		if (msg_len <= sctp_wspace(asoc))
6167 			break;
6168 
6169 		/* Let another process have a go.  Since we are going
6170 		 * to sleep anyway.
6171 		 */
6172 		sctp_release_sock(sk);
6173 		current_timeo = schedule_timeout(current_timeo);
6174 		BUG_ON(sk != asoc->base.sk);
6175 		sctp_lock_sock(sk);
6176 
6177 		*timeo_p = current_timeo;
6178 	}
6179 
6180 out:
6181 	finish_wait(&asoc->wait, &wait);
6182 
6183 	/* Release the association's refcnt.  */
6184 	sctp_association_put(asoc);
6185 
6186 	return err;
6187 
6188 do_error:
6189 	err = -EPIPE;
6190 	goto out;
6191 
6192 do_interrupted:
6193 	err = sock_intr_errno(*timeo_p);
6194 	goto out;
6195 
6196 do_nonblock:
6197 	err = -EAGAIN;
6198 	goto out;
6199 }
6200 
6201 void sctp_data_ready(struct sock *sk, int len)
6202 {
6203 	struct socket_wq *wq;
6204 
6205 	rcu_read_lock();
6206 	wq = rcu_dereference(sk->sk_wq);
6207 	if (wq_has_sleeper(wq))
6208 		wake_up_interruptible_sync_poll(&wq->wait, POLLIN |
6209 						POLLRDNORM | POLLRDBAND);
6210 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
6211 	rcu_read_unlock();
6212 }
6213 
6214 /* If socket sndbuf has changed, wake up all per association waiters.  */
6215 void sctp_write_space(struct sock *sk)
6216 {
6217 	struct sctp_association *asoc;
6218 
6219 	/* Wake up the tasks in each wait queue.  */
6220 	list_for_each_entry(asoc, &((sctp_sk(sk))->ep->asocs), asocs) {
6221 		__sctp_write_space(asoc);
6222 	}
6223 }
6224 
6225 /* Is there any sndbuf space available on the socket?
6226  *
6227  * Note that sk_wmem_alloc is the sum of the send buffers on all of the
6228  * associations on the same socket.  For a UDP-style socket with
6229  * multiple associations, it is possible for it to be "unwriteable"
6230  * prematurely.  I assume that this is acceptable because
6231  * a premature "unwriteable" is better than an accidental "writeable" which
6232  * would cause an unwanted block under certain circumstances.  For the 1-1
6233  * UDP-style sockets or TCP-style sockets, this code should work.
6234  *  - Daisy
6235  */
6236 static int sctp_writeable(struct sock *sk)
6237 {
6238 	int amt = 0;
6239 
6240 	amt = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
6241 	if (amt < 0)
6242 		amt = 0;
6243 	return amt;
6244 }
6245 
6246 /* Wait for an association to go into ESTABLISHED state. If timeout is 0,
6247  * returns immediately with EINPROGRESS.
6248  */
6249 static int sctp_wait_for_connect(struct sctp_association *asoc, long *timeo_p)
6250 {
6251 	struct sock *sk = asoc->base.sk;
6252 	int err = 0;
6253 	long current_timeo = *timeo_p;
6254 	DEFINE_WAIT(wait);
6255 
6256 	SCTP_DEBUG_PRINTK("%s: asoc=%p, timeo=%ld\n", __func__, asoc,
6257 			  (long)(*timeo_p));
6258 
6259 	/* Increment the association's refcnt.  */
6260 	sctp_association_hold(asoc);
6261 
6262 	for (;;) {
6263 		prepare_to_wait_exclusive(&asoc->wait, &wait,
6264 					  TASK_INTERRUPTIBLE);
6265 		if (!*timeo_p)
6266 			goto do_nonblock;
6267 		if (sk->sk_shutdown & RCV_SHUTDOWN)
6268 			break;
6269 		if (sk->sk_err || asoc->state >= SCTP_STATE_SHUTDOWN_PENDING ||
6270 		    asoc->base.dead)
6271 			goto do_error;
6272 		if (signal_pending(current))
6273 			goto do_interrupted;
6274 
6275 		if (sctp_state(asoc, ESTABLISHED))
6276 			break;
6277 
6278 		/* Let another process have a go.  Since we are going
6279 		 * to sleep anyway.
6280 		 */
6281 		sctp_release_sock(sk);
6282 		current_timeo = schedule_timeout(current_timeo);
6283 		sctp_lock_sock(sk);
6284 
6285 		*timeo_p = current_timeo;
6286 	}
6287 
6288 out:
6289 	finish_wait(&asoc->wait, &wait);
6290 
6291 	/* Release the association's refcnt.  */
6292 	sctp_association_put(asoc);
6293 
6294 	return err;
6295 
6296 do_error:
6297 	if (asoc->init_err_counter + 1 > asoc->max_init_attempts)
6298 		err = -ETIMEDOUT;
6299 	else
6300 		err = -ECONNREFUSED;
6301 	goto out;
6302 
6303 do_interrupted:
6304 	err = sock_intr_errno(*timeo_p);
6305 	goto out;
6306 
6307 do_nonblock:
6308 	err = -EINPROGRESS;
6309 	goto out;
6310 }
6311 
6312 static int sctp_wait_for_accept(struct sock *sk, long timeo)
6313 {
6314 	struct sctp_endpoint *ep;
6315 	int err = 0;
6316 	DEFINE_WAIT(wait);
6317 
6318 	ep = sctp_sk(sk)->ep;
6319 
6320 
6321 	for (;;) {
6322 		prepare_to_wait_exclusive(sk_sleep(sk), &wait,
6323 					  TASK_INTERRUPTIBLE);
6324 
6325 		if (list_empty(&ep->asocs)) {
6326 			sctp_release_sock(sk);
6327 			timeo = schedule_timeout(timeo);
6328 			sctp_lock_sock(sk);
6329 		}
6330 
6331 		err = -EINVAL;
6332 		if (!sctp_sstate(sk, LISTENING))
6333 			break;
6334 
6335 		err = 0;
6336 		if (!list_empty(&ep->asocs))
6337 			break;
6338 
6339 		err = sock_intr_errno(timeo);
6340 		if (signal_pending(current))
6341 			break;
6342 
6343 		err = -EAGAIN;
6344 		if (!timeo)
6345 			break;
6346 	}
6347 
6348 	finish_wait(sk_sleep(sk), &wait);
6349 
6350 	return err;
6351 }
6352 
6353 static void sctp_wait_for_close(struct sock *sk, long timeout)
6354 {
6355 	DEFINE_WAIT(wait);
6356 
6357 	do {
6358 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
6359 		if (list_empty(&sctp_sk(sk)->ep->asocs))
6360 			break;
6361 		sctp_release_sock(sk);
6362 		timeout = schedule_timeout(timeout);
6363 		sctp_lock_sock(sk);
6364 	} while (!signal_pending(current) && timeout);
6365 
6366 	finish_wait(sk_sleep(sk), &wait);
6367 }
6368 
6369 static void sctp_skb_set_owner_r_frag(struct sk_buff *skb, struct sock *sk)
6370 {
6371 	struct sk_buff *frag;
6372 
6373 	if (!skb->data_len)
6374 		goto done;
6375 
6376 	/* Don't forget the fragments. */
6377 	skb_walk_frags(skb, frag)
6378 		sctp_skb_set_owner_r_frag(frag, sk);
6379 
6380 done:
6381 	sctp_skb_set_owner_r(skb, sk);
6382 }
6383 
6384 void sctp_copy_sock(struct sock *newsk, struct sock *sk,
6385 		    struct sctp_association *asoc)
6386 {
6387 	struct inet_sock *inet = inet_sk(sk);
6388 	struct inet_sock *newinet;
6389 
6390 	newsk->sk_type = sk->sk_type;
6391 	newsk->sk_bound_dev_if = sk->sk_bound_dev_if;
6392 	newsk->sk_flags = sk->sk_flags;
6393 	newsk->sk_no_check = sk->sk_no_check;
6394 	newsk->sk_reuse = sk->sk_reuse;
6395 
6396 	newsk->sk_shutdown = sk->sk_shutdown;
6397 	newsk->sk_destruct = inet_sock_destruct;
6398 	newsk->sk_family = sk->sk_family;
6399 	newsk->sk_protocol = IPPROTO_SCTP;
6400 	newsk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
6401 	newsk->sk_sndbuf = sk->sk_sndbuf;
6402 	newsk->sk_rcvbuf = sk->sk_rcvbuf;
6403 	newsk->sk_lingertime = sk->sk_lingertime;
6404 	newsk->sk_rcvtimeo = sk->sk_rcvtimeo;
6405 	newsk->sk_sndtimeo = sk->sk_sndtimeo;
6406 
6407 	newinet = inet_sk(newsk);
6408 
6409 	/* Initialize sk's sport, dport, rcv_saddr and daddr for
6410 	 * getsockname() and getpeername()
6411 	 */
6412 	newinet->inet_sport = inet->inet_sport;
6413 	newinet->inet_saddr = inet->inet_saddr;
6414 	newinet->inet_rcv_saddr = inet->inet_rcv_saddr;
6415 	newinet->inet_dport = htons(asoc->peer.port);
6416 	newinet->pmtudisc = inet->pmtudisc;
6417 	newinet->inet_id = asoc->next_tsn ^ jiffies;
6418 
6419 	newinet->uc_ttl = inet->uc_ttl;
6420 	newinet->mc_loop = 1;
6421 	newinet->mc_ttl = 1;
6422 	newinet->mc_index = 0;
6423 	newinet->mc_list = NULL;
6424 }
6425 
6426 /* Populate the fields of the newsk from the oldsk and migrate the assoc
6427  * and its messages to the newsk.
6428  */
6429 static void sctp_sock_migrate(struct sock *oldsk, struct sock *newsk,
6430 			      struct sctp_association *assoc,
6431 			      sctp_socket_type_t type)
6432 {
6433 	struct sctp_sock *oldsp = sctp_sk(oldsk);
6434 	struct sctp_sock *newsp = sctp_sk(newsk);
6435 	struct sctp_bind_bucket *pp; /* hash list port iterator */
6436 	struct sctp_endpoint *newep = newsp->ep;
6437 	struct sk_buff *skb, *tmp;
6438 	struct sctp_ulpevent *event;
6439 	struct sctp_bind_hashbucket *head;
6440 
6441 	/* Migrate socket buffer sizes and all the socket level options to the
6442 	 * new socket.
6443 	 */
6444 	newsk->sk_sndbuf = oldsk->sk_sndbuf;
6445 	newsk->sk_rcvbuf = oldsk->sk_rcvbuf;
6446 	/* Brute force copy old sctp opt. */
6447 	inet_sk_copy_descendant(newsk, oldsk);
6448 
6449 	/* Restore the ep value that was overwritten with the above structure
6450 	 * copy.
6451 	 */
6452 	newsp->ep = newep;
6453 	newsp->hmac = NULL;
6454 
6455 	/* Hook this new socket in to the bind_hash list. */
6456 	head = &sctp_port_hashtable[sctp_phashfn(inet_sk(oldsk)->inet_num)];
6457 	sctp_local_bh_disable();
6458 	sctp_spin_lock(&head->lock);
6459 	pp = sctp_sk(oldsk)->bind_hash;
6460 	sk_add_bind_node(newsk, &pp->owner);
6461 	sctp_sk(newsk)->bind_hash = pp;
6462 	inet_sk(newsk)->inet_num = inet_sk(oldsk)->inet_num;
6463 	sctp_spin_unlock(&head->lock);
6464 	sctp_local_bh_enable();
6465 
6466 	/* Copy the bind_addr list from the original endpoint to the new
6467 	 * endpoint so that we can handle restarts properly
6468 	 */
6469 	sctp_bind_addr_dup(&newsp->ep->base.bind_addr,
6470 				&oldsp->ep->base.bind_addr, GFP_KERNEL);
6471 
6472 	/* Move any messages in the old socket's receive queue that are for the
6473 	 * peeled off association to the new socket's receive queue.
6474 	 */
6475 	sctp_skb_for_each(skb, &oldsk->sk_receive_queue, tmp) {
6476 		event = sctp_skb2event(skb);
6477 		if (event->asoc == assoc) {
6478 			__skb_unlink(skb, &oldsk->sk_receive_queue);
6479 			__skb_queue_tail(&newsk->sk_receive_queue, skb);
6480 			sctp_skb_set_owner_r_frag(skb, newsk);
6481 		}
6482 	}
6483 
6484 	/* Clean up any messages pending delivery due to partial
6485 	 * delivery.   Three cases:
6486 	 * 1) No partial deliver;  no work.
6487 	 * 2) Peeling off partial delivery; keep pd_lobby in new pd_lobby.
6488 	 * 3) Peeling off non-partial delivery; move pd_lobby to receive_queue.
6489 	 */
6490 	skb_queue_head_init(&newsp->pd_lobby);
6491 	atomic_set(&sctp_sk(newsk)->pd_mode, assoc->ulpq.pd_mode);
6492 
6493 	if (atomic_read(&sctp_sk(oldsk)->pd_mode)) {
6494 		struct sk_buff_head *queue;
6495 
6496 		/* Decide which queue to move pd_lobby skbs to. */
6497 		if (assoc->ulpq.pd_mode) {
6498 			queue = &newsp->pd_lobby;
6499 		} else
6500 			queue = &newsk->sk_receive_queue;
6501 
6502 		/* Walk through the pd_lobby, looking for skbs that
6503 		 * need moved to the new socket.
6504 		 */
6505 		sctp_skb_for_each(skb, &oldsp->pd_lobby, tmp) {
6506 			event = sctp_skb2event(skb);
6507 			if (event->asoc == assoc) {
6508 				__skb_unlink(skb, &oldsp->pd_lobby);
6509 				__skb_queue_tail(queue, skb);
6510 				sctp_skb_set_owner_r_frag(skb, newsk);
6511 			}
6512 		}
6513 
6514 		/* Clear up any skbs waiting for the partial
6515 		 * delivery to finish.
6516 		 */
6517 		if (assoc->ulpq.pd_mode)
6518 			sctp_clear_pd(oldsk, NULL);
6519 
6520 	}
6521 
6522 	sctp_skb_for_each(skb, &assoc->ulpq.reasm, tmp)
6523 		sctp_skb_set_owner_r_frag(skb, newsk);
6524 
6525 	sctp_skb_for_each(skb, &assoc->ulpq.lobby, tmp)
6526 		sctp_skb_set_owner_r_frag(skb, newsk);
6527 
6528 	/* Set the type of socket to indicate that it is peeled off from the
6529 	 * original UDP-style socket or created with the accept() call on a
6530 	 * TCP-style socket..
6531 	 */
6532 	newsp->type = type;
6533 
6534 	/* Mark the new socket "in-use" by the user so that any packets
6535 	 * that may arrive on the association after we've moved it are
6536 	 * queued to the backlog.  This prevents a potential race between
6537 	 * backlog processing on the old socket and new-packet processing
6538 	 * on the new socket.
6539 	 *
6540 	 * The caller has just allocated newsk so we can guarantee that other
6541 	 * paths won't try to lock it and then oldsk.
6542 	 */
6543 	lock_sock_nested(newsk, SINGLE_DEPTH_NESTING);
6544 	sctp_assoc_migrate(assoc, newsk);
6545 
6546 	/* If the association on the newsk is already closed before accept()
6547 	 * is called, set RCV_SHUTDOWN flag.
6548 	 */
6549 	if (sctp_state(assoc, CLOSED) && sctp_style(newsk, TCP))
6550 		newsk->sk_shutdown |= RCV_SHUTDOWN;
6551 
6552 	newsk->sk_state = SCTP_SS_ESTABLISHED;
6553 	sctp_release_sock(newsk);
6554 }
6555 
6556 
6557 /* This proto struct describes the ULP interface for SCTP.  */
6558 struct proto sctp_prot = {
6559 	.name        =	"SCTP",
6560 	.owner       =	THIS_MODULE,
6561 	.close       =	sctp_close,
6562 	.connect     =	sctp_connect,
6563 	.disconnect  =	sctp_disconnect,
6564 	.accept      =	sctp_accept,
6565 	.ioctl       =	sctp_ioctl,
6566 	.init        =	sctp_init_sock,
6567 	.destroy     =	sctp_destroy_sock,
6568 	.shutdown    =	sctp_shutdown,
6569 	.setsockopt  =	sctp_setsockopt,
6570 	.getsockopt  =	sctp_getsockopt,
6571 	.sendmsg     =	sctp_sendmsg,
6572 	.recvmsg     =	sctp_recvmsg,
6573 	.bind        =	sctp_bind,
6574 	.backlog_rcv =	sctp_backlog_rcv,
6575 	.hash        =	sctp_hash,
6576 	.unhash      =	sctp_unhash,
6577 	.get_port    =	sctp_get_port,
6578 	.obj_size    =  sizeof(struct sctp_sock),
6579 	.sysctl_mem  =  sysctl_sctp_mem,
6580 	.sysctl_rmem =  sysctl_sctp_rmem,
6581 	.sysctl_wmem =  sysctl_sctp_wmem,
6582 	.memory_pressure = &sctp_memory_pressure,
6583 	.enter_memory_pressure = sctp_enter_memory_pressure,
6584 	.memory_allocated = &sctp_memory_allocated,
6585 	.sockets_allocated = &sctp_sockets_allocated,
6586 };
6587 
6588 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
6589 
6590 struct proto sctpv6_prot = {
6591 	.name		= "SCTPv6",
6592 	.owner		= THIS_MODULE,
6593 	.close		= sctp_close,
6594 	.connect	= sctp_connect,
6595 	.disconnect	= sctp_disconnect,
6596 	.accept		= sctp_accept,
6597 	.ioctl		= sctp_ioctl,
6598 	.init		= sctp_init_sock,
6599 	.destroy	= sctp_destroy_sock,
6600 	.shutdown	= sctp_shutdown,
6601 	.setsockopt	= sctp_setsockopt,
6602 	.getsockopt	= sctp_getsockopt,
6603 	.sendmsg	= sctp_sendmsg,
6604 	.recvmsg	= sctp_recvmsg,
6605 	.bind		= sctp_bind,
6606 	.backlog_rcv	= sctp_backlog_rcv,
6607 	.hash		= sctp_hash,
6608 	.unhash		= sctp_unhash,
6609 	.get_port	= sctp_get_port,
6610 	.obj_size	= sizeof(struct sctp6_sock),
6611 	.sysctl_mem	= sysctl_sctp_mem,
6612 	.sysctl_rmem	= sysctl_sctp_rmem,
6613 	.sysctl_wmem	= sysctl_sctp_wmem,
6614 	.memory_pressure = &sctp_memory_pressure,
6615 	.enter_memory_pressure = sctp_enter_memory_pressure,
6616 	.memory_allocated = &sctp_memory_allocated,
6617 	.sockets_allocated = &sctp_sockets_allocated,
6618 };
6619 #endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
6620