xref: /titanic_52/usr/src/uts/common/inet/sctp/sctp_conn.c (revision 6185db853e024a486ff8837e6784dd290d866112)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include <sys/types.h>
30 #include <sys/systm.h>
31 #include <sys/stream.h>
32 #include <sys/cmn_err.h>
33 #include <sys/kmem.h>
34 #define	_SUN_TPI_VERSION 2
35 #include <sys/tihdr.h>
36 #include <sys/stropts.h>
37 #include <sys/strsubr.h>
38 #include <sys/socket.h>
39 #include <sys/tsol/tndb.h>
40 
41 #include <netinet/in.h>
42 #include <netinet/ip6.h>
43 
44 #include <inet/common.h>
45 #include <inet/ip.h>
46 #include <inet/ip6.h>
47 #include <inet/ipclassifier.h>
48 #include <inet/ipsec_impl.h>
49 
50 #include "sctp_impl.h"
51 #include "sctp_addr.h"
52 
53 /*
54  * Common accept code.  Called by sctp_conn_request.
55  * cr_pkt is the INIT / INIT ACK packet.
56  */
57 static int
58 sctp_accept_comm(sctp_t *listener, sctp_t *acceptor, mblk_t *cr_pkt,
59     uint_t ip_hdr_len, sctp_init_chunk_t *iack)
60 {
61 
62 	sctp_hdr_t		*sctph;
63 	sctp_chunk_hdr_t	*ich;
64 	sctp_init_chunk_t	*init;
65 	int			err;
66 	uint_t			sctp_options;
67 	conn_t			*aconnp;
68 	conn_t			*lconnp;
69 	cred_t			*cr;
70 
71 	sctph = (sctp_hdr_t *)(cr_pkt->b_rptr + ip_hdr_len);
72 	ASSERT(OK_32PTR(sctph));
73 
74 	acceptor->sctp_lport = listener->sctp_lport;
75 	acceptor->sctp_fport = sctph->sh_sport;
76 
77 	ich = (sctp_chunk_hdr_t *)(iack + 1);
78 	init = (sctp_init_chunk_t *)(ich + 1);
79 
80 	/* acceptor isn't in any fanouts yet, so don't need to hold locks */
81 	ASSERT(acceptor->sctp_faddrs == NULL);
82 	err = sctp_get_addrparams(acceptor, listener, cr_pkt, ich,
83 	    &sctp_options);
84 	if (err != 0)
85 		return (err);
86 
87 	aconnp = acceptor->sctp_connp;
88 	lconnp = listener->sctp_connp;
89 	if (lconnp->conn_mlp_type != mlptSingle) {
90 		cr = aconnp->conn_peercred = DB_CRED(cr_pkt);
91 		if (cr != NULL)
92 			crhold(cr);
93 	}
94 
95 	if ((err = sctp_set_hdraddrs(acceptor)) != 0)
96 		return (err);
97 
98 	if ((sctp_options & SCTP_PRSCTP_OPTION) &&
99 	    listener->sctp_prsctp_aware && sctp_prsctp_enabled) {
100 		acceptor->sctp_prsctp_aware = B_TRUE;
101 	} else {
102 		acceptor->sctp_prsctp_aware = B_FALSE;
103 	}
104 	/* The new sctp_t is fully bound now. */
105 	acceptor->sctp_connp->conn_fully_bound = B_TRUE;
106 
107 	/* Get  initial TSNs */
108 	acceptor->sctp_ltsn = ntohl(iack->sic_inittsn);
109 	acceptor->sctp_recovery_tsn = acceptor->sctp_lastack_rxd =
110 	    acceptor->sctp_ltsn - 1;
111 	acceptor->sctp_adv_pap = acceptor->sctp_lastack_rxd;
112 	/* Serial numbers are initialized to the same value as the TSNs */
113 	acceptor->sctp_lcsn = acceptor->sctp_ltsn;
114 
115 	if (!sctp_initialize_params(acceptor, init, iack))
116 		return (ENOMEM);
117 
118 	/*
119 	 * Copy sctp_secret from the listener in case we need to validate
120 	 * a possibly delayed cookie.
121 	 */
122 	bcopy(listener->sctp_secret, acceptor->sctp_secret, SCTP_SECRET_LEN);
123 	bcopy(listener->sctp_old_secret, acceptor->sctp_old_secret,
124 	    SCTP_SECRET_LEN);
125 	acceptor->sctp_last_secret_update = lbolt64;
126 
127 	/*
128 	 * After acceptor is inserted in the hash list, it can be found.
129 	 * So we need to lock it here.
130 	 */
131 	RUN_SCTP(acceptor);
132 
133 	sctp_conn_hash_insert(&sctp_conn_fanout[
134 	    SCTP_CONN_HASH(acceptor->sctp_ports)], acceptor, 0);
135 	sctp_bind_hash_insert(&sctp_bind_fanout[
136 	    SCTP_BIND_HASH(ntohs(acceptor->sctp_lport))], acceptor, 0);
137 
138 	/*
139 	 * No need to check for multicast destination since ip will only pass
140 	 * up multicasts to those that have expressed interest
141 	 * TODO: what about rejecting broadcasts?
142 	 * Also check that source is not a multicast or broadcast address.
143 	 */
144 	/* XXXSCTP */
145 	acceptor->sctp_state = SCTPS_ESTABLISHED;
146 	acceptor->sctp_assoc_start_time = (uint32_t)lbolt;
147 	/*
148 	 * listener->sctp_rwnd should be the default window size or a
149 	 * window size changed via SO_RCVBUF option.
150 	 */
151 	acceptor->sctp_rwnd = listener->sctp_rwnd;
152 	acceptor->sctp_irwnd = acceptor->sctp_rwnd;
153 	bcopy(&listener->sctp_upcalls, &acceptor->sctp_upcalls,
154 	    sizeof (sctp_upcalls_t));
155 
156 	return (0);
157 }
158 
159 /* Process the COOKIE packet, mp, directed at the listener 'sctp' */
160 sctp_t *
161 sctp_conn_request(sctp_t *sctp, mblk_t *mp, uint_t ifindex, uint_t ip_hdr_len,
162     sctp_init_chunk_t *iack, mblk_t *ipsec_mp)
163 {
164 	sctp_t	*eager;
165 	uint_t	ipvers;
166 	ip6_t	*ip6h;
167 	int	err;
168 	conn_t	*connp, *econnp;
169 
170 	/*
171 	 * No need to check for duplicate as this is the listener
172 	 * and we are holding the lock.  This means that no new
173 	 * connection can be created out of it.  And since the
174 	 * fanout already done cannot find a match, it means that
175 	 * there is no duplicate.
176 	 */
177 	ipvers = IPH_HDR_VERSION(mp->b_rptr);
178 	ASSERT(ipvers == IPV6_VERSION || ipvers == IPV4_VERSION);
179 	ASSERT(OK_32PTR(mp->b_rptr));
180 
181 	if ((eager = sctp_create_eager(sctp)) == NULL) {
182 		return (NULL);
183 	}
184 
185 	if (ipvers != IPV4_VERSION) {
186 		ip6h = (ip6_t *)mp->b_rptr;
187 		if (IN6_IS_ADDR_LINKLOCAL(&ip6h->ip6_src))
188 			eager->sctp_linklocal = 1;
189 		/*
190 		 * Record ifindex (might be zero) to tie this connection to
191 		 * that interface if either the listener was bound or
192 		 * if the connection is using link-local addresses.
193 		 */
194 		if (sctp->sctp_bound_if == ifindex ||
195 		    IN6_IS_ADDR_LINKLOCAL(&ip6h->ip6_src))
196 			eager->sctp_bound_if = ifindex;
197 		/*
198 		 * XXX broken. bound_if is always overwritten by statement
199 		 * below. What is the right thing to do here?
200 		 */
201 		eager->sctp_bound_if = sctp->sctp_bound_if;
202 	}
203 
204 	connp = sctp->sctp_connp;
205 	econnp = eager->sctp_connp;
206 
207 	if (connp->conn_policy != NULL) {
208 		ipsec_in_t *ii;
209 
210 		ASSERT(ipsec_mp != NULL);
211 		ii = (ipsec_in_t *)(ipsec_mp->b_rptr);
212 		ASSERT(ii->ipsec_in_policy == NULL);
213 		IPPH_REFHOLD(connp->conn_policy);
214 		ii->ipsec_in_policy = connp->conn_policy;
215 
216 		ipsec_mp->b_datap->db_type = IPSEC_POLICY_SET;
217 		if (!ip_bind_ipsec_policy_set(econnp, ipsec_mp)) {
218 			sctp_close_eager(eager);
219 			BUMP_MIB(&sctp_mib, sctpListenDrop);
220 			return (NULL);
221 		}
222 	}
223 
224 	if (ipsec_mp != NULL) {
225 		/*
226 		 * XXX need to fix the cached policy issue here.
227 		 * We temporarily set the conn_src/conn_rem here so
228 		 * that IPsec can use it for the latched policy
229 		 * selector.  This is obvioursly wrong as SCTP can
230 		 * use different addresses...
231 		 */
232 		if (ipvers == IPV4_VERSION) {
233 			ipha_t	*ipha;
234 
235 			ipha = (ipha_t *)mp->b_rptr;
236 			econnp->conn_src = ipha->ipha_dst;
237 			econnp->conn_rem = ipha->ipha_src;
238 		} else {
239 			econnp->conn_srcv6 = ip6h->ip6_dst;
240 			econnp->conn_remv6 = ip6h->ip6_src;
241 		}
242 	}
243 	if (ipsec_conn_cache_policy(econnp, ipvers == IPV4_VERSION) != 0) {
244 		sctp_close_eager(eager);
245 		BUMP_MIB(&sctp_mib, sctpListenDrop);
246 		return (NULL);
247 	}
248 
249 	err = sctp_accept_comm(sctp, eager, mp, ip_hdr_len, iack);
250 	if (err) {
251 		sctp_close_eager(eager);
252 		BUMP_MIB(&sctp_mib, sctpListenDrop);
253 		return (NULL);
254 	}
255 
256 	/*
257 	 * On a clustered note send this notification to the clustering
258 	 * subsystem.
259 	 */
260 	if (cl_sctp_connect != NULL) {
261 		uchar_t	*slist;
262 		uchar_t	*flist;
263 		size_t	fsize;
264 		size_t	ssize;
265 
266 		fsize = sizeof (in6_addr_t) * eager->sctp_nfaddrs;
267 		ssize = sizeof (in6_addr_t) * eager->sctp_nsaddrs;
268 		slist = kmem_alloc(ssize, KM_NOSLEEP);
269 		flist = kmem_alloc(fsize, KM_NOSLEEP);
270 		if (slist == NULL || flist == NULL) {
271 			if (slist != NULL)
272 				kmem_free(slist, ssize);
273 			if (flist != NULL)
274 				kmem_free(flist, fsize);
275 			sctp_close_eager(eager);
276 			BUMP_MIB(&sctp_mib, sctpListenDrop);
277 			SCTP_KSTAT(sctp_cl_connect);
278 			return (NULL);
279 		}
280 		/* The clustering module frees these list */
281 		sctp_get_saddr_list(eager, slist, ssize);
282 		sctp_get_faddr_list(eager, flist, fsize);
283 		(*cl_sctp_connect)(eager->sctp_family, slist,
284 		    eager->sctp_nsaddrs, eager->sctp_lport, flist,
285 		    eager->sctp_nfaddrs, eager->sctp_fport, B_FALSE,
286 		    (cl_sctp_handle_t)eager);
287 	}
288 
289 	/* Connection established, so send up the conn_ind */
290 	if ((eager->sctp_ulpd = sctp->sctp_ulp_newconn(sctp->sctp_ulpd,
291 	    eager)) == NULL) {
292 		sctp_close_eager(eager);
293 		BUMP_MIB(&sctp_mib, sctpListenDrop);
294 		return (NULL);
295 	}
296 	ASSERT(SCTP_IS_DETACHED(eager));
297 	eager->sctp_detached = B_FALSE;
298 	if (eager->sctp_family == AF_INET) {
299 		eager->sctp_ulp_prop(eager->sctp_ulpd,
300 		    sctp_wroff_xtra + sizeof (sctp_data_hdr_t) +
301 		    sctp->sctp_hdr_len, strmsgsz);
302 	} else {
303 		eager->sctp_ulp_prop(eager->sctp_ulpd,
304 		    sctp_wroff_xtra + sizeof (sctp_data_hdr_t) +
305 		    sctp->sctp_hdr6_len, strmsgsz);
306 	}
307 	return (eager);
308 }
309 
310 /*
311  * Connect to a peer - this function inserts the sctp in the
312  * bind and conn fanouts, sends the INIT, and replies to the client
313  * with an OK ack.
314  */
315 int
316 sctp_connect(sctp_t *sctp, const struct sockaddr *dst, uint32_t addrlen)
317 {
318 	sin_t		*sin;
319 	sin6_t		*sin6;
320 	in6_addr_t	dstaddr;
321 	in_port_t	dstport;
322 	mblk_t		*initmp;
323 	sctp_tf_t	*tbf;
324 	sctp_t		*lsctp;
325 	char		buf[INET6_ADDRSTRLEN];
326 	int		sleep = sctp->sctp_cansleep ? KM_SLEEP : KM_NOSLEEP;
327 	int 		hdrlen;
328 	ip6_rthdr_t	*rth;
329 	int		err;
330 	sctp_faddr_t	*cur_fp;
331 
332 	/*
333 	 * Determine packet type based on type of address passed in
334 	 * the request should contain an IPv4 or IPv6 address.
335 	 * Make sure that address family matches the type of
336 	 * family of the the address passed down
337 	 */
338 	if (addrlen < sizeof (sin_t)) {
339 		return (EINVAL);
340 	}
341 	switch (dst->sa_family) {
342 	case AF_INET:
343 		sin = (sin_t *)dst;
344 
345 		/* Check for attempt to connect to non-unicast */
346 		if (IN_MULTICAST(sin->sin_addr.s_addr) ||
347 		    (sin->sin_addr.s_addr == INADDR_BROADCAST)) {
348 			ip0dbg(("sctp_connect: non-unicast\n"));
349 			return (EINVAL);
350 		}
351 		if (sctp->sctp_connp->conn_ipv6_v6only)
352 			return (EAFNOSUPPORT);
353 
354 		/* convert to v6 mapped */
355 		/* Check for attempt to connect to INADDR_ANY */
356 		if (sin->sin_addr.s_addr == INADDR_ANY)  {
357 			struct in_addr v4_addr;
358 			/*
359 			 * SunOS 4.x and 4.3 BSD allow an application
360 			 * to connect a TCP socket to INADDR_ANY.
361 			 * When they do this, the kernel picks the
362 			 * address of one interface and uses it
363 			 * instead.  The kernel usually ends up
364 			 * picking the address of the loopback
365 			 * interface.  This is an undocumented feature.
366 			 * However, we provide the same thing here
367 			 * in case any TCP apps that use this feature
368 			 * are being ported to SCTP...
369 			 */
370 			v4_addr.s_addr = htonl(INADDR_LOOPBACK);
371 			IN6_INADDR_TO_V4MAPPED(&v4_addr, &dstaddr);
372 		} else {
373 			IN6_INADDR_TO_V4MAPPED(&sin->sin_addr, &dstaddr);
374 		}
375 		dstport = sin->sin_port;
376 		if (sin->sin_family == AF_INET) {
377 			hdrlen = sctp->sctp_hdr_len;
378 		} else {
379 			hdrlen = sctp->sctp_hdr6_len;
380 		}
381 		break;
382 	case AF_INET6:
383 		sin6 = (sin6_t *)dst;
384 		/* Check for attempt to connect to non-unicast. */
385 		if ((addrlen < sizeof (sin6_t)) ||
386 		    IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) {
387 			ip0dbg(("sctp_connect: non-unicast\n"));
388 			return (EINVAL);
389 		}
390 		if (sctp->sctp_connp->conn_ipv6_v6only &&
391 		    IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
392 			return (EAFNOSUPPORT);
393 		}
394 		/* check for attempt to connect to unspec */
395 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
396 			dstaddr = ipv6_loopback;
397 		} else {
398 			dstaddr = sin6->sin6_addr;
399 			if (IN6_IS_ADDR_LINKLOCAL(&dstaddr))
400 				sctp->sctp_linklocal = 1;
401 		}
402 		dstport = sin6->sin6_port;
403 		hdrlen = sctp->sctp_hdr6_len;
404 		break;
405 	default:
406 		dprint(1, ("sctp_connect: unknown family %d\n",
407 			dst->sa_family));
408 		return (EAFNOSUPPORT);
409 	}
410 
411 	(void) inet_ntop(AF_INET6, &dstaddr, buf, sizeof (buf));
412 	dprint(1, ("sctp_connect: attempting connect to %s...\n", buf));
413 
414 	RUN_SCTP(sctp);
415 
416 	if (sctp->sctp_family != dst->sa_family) {
417 		WAKE_SCTP(sctp);
418 		return (EINVAL);
419 	}
420 
421 	switch (sctp->sctp_state) {
422 	case SCTPS_IDLE: {
423 		struct sockaddr_storage	ss;
424 
425 		/*
426 		 * We support a quick connect capability here, allowing
427 		 * clients to transition directly from IDLE to COOKIE_WAIT.
428 		 * sctp_bindi will pick an unused port, insert the connection
429 		 * in the bind hash and transition to BOUND state. SCTP
430 		 * picks and uses what it considers the optimal local address
431 		 * set (just like specifiying INADDR_ANY to bind()).
432 		 */
433 		dprint(1, ("sctp_connect: idle, attempting bind...\n"));
434 		ASSERT(sctp->sctp_nsaddrs == 0);
435 
436 		bzero(&ss, sizeof (ss));
437 		ss.ss_family = sctp->sctp_family;
438 		WAKE_SCTP(sctp);
439 		if ((err = sctp_bind(sctp, (struct sockaddr *)&ss,
440 		    sizeof (ss))) != 0) {
441 			return (err);
442 		}
443 		RUN_SCTP(sctp);
444 		sctp->sctp_bound_to_all = 1;
445 		/* FALLTHRU */
446 	}
447 
448 	case SCTPS_BOUND:
449 		ASSERT(sctp->sctp_nsaddrs > 0);
450 
451 		/* do the connect */
452 		/* XXX check for attempt to connect to self */
453 		sctp->sctp_fport = dstport;
454 
455 		ASSERT(sctp->sctp_iphc);
456 		ASSERT(sctp->sctp_iphc6);
457 
458 		/*
459 		 * Don't allow this connection to completely duplicate
460 		 * an existing connection.
461 		 *
462 		 * Ensure that the duplicate check and insertion is atomic.
463 		 */
464 		sctp_conn_hash_remove(sctp);
465 		tbf = &sctp_conn_fanout[SCTP_CONN_HASH(sctp->sctp_ports)];
466 		mutex_enter(&tbf->tf_lock);
467 		lsctp = sctp_lookup(sctp, &dstaddr, tbf, &sctp->sctp_ports,
468 		    SCTPS_COOKIE_WAIT);
469 		if (lsctp != NULL) {
470 			/* found a duplicate connection */
471 			mutex_exit(&tbf->tf_lock);
472 			SCTP_REFRELE(lsctp);
473 			WAKE_SCTP(sctp);
474 			return (EADDRINUSE);
475 		}
476 		/*
477 		 * OK; set up the peer addr (this may grow after we get
478 		 * the INIT ACK from the peer with additional addresses).
479 		 */
480 		if ((err = sctp_add_faddr(sctp, &dstaddr, sleep,
481 		    B_FALSE)) != 0) {
482 			mutex_exit(&tbf->tf_lock);
483 			WAKE_SCTP(sctp);
484 			return (err);
485 		}
486 		/* No valid src addr, return. */
487 		if (sctp->sctp_faddrs->state == SCTP_FADDRS_UNREACH) {
488 			mutex_exit(&tbf->tf_lock);
489 			WAKE_SCTP(sctp);
490 			return (EADDRNOTAVAIL);
491 		}
492 		sctp->sctp_primary = sctp->sctp_faddrs;
493 		sctp->sctp_current = sctp->sctp_faddrs;
494 		cur_fp = sctp->sctp_current;
495 		sctp->sctp_mss = sctp->sctp_faddrs->sfa_pmss;
496 		sctp_conn_hash_insert(tbf, sctp, 1);
497 		mutex_exit(&tbf->tf_lock);
498 
499 		/* initialize composite headers */
500 		if ((err = sctp_set_hdraddrs(sctp)) != 0) {
501 			sctp_conn_hash_remove(sctp);
502 			WAKE_SCTP(sctp);
503 			return (err);
504 		}
505 
506 		/*
507 		 * Massage a routing header (if present) putting the first hop
508 		 * in ip6_dst.
509 		 */
510 		rth = ip_find_rthdr_v6(sctp->sctp_ip6h,
511 		    (uint8_t *)sctp->sctp_sctph6);
512 		if (rth != NULL)
513 			(void) ip_massage_options_v6(sctp->sctp_ip6h, rth);
514 
515 		/*
516 		 * Turn off the don't fragment bit on the (only) faddr,
517 		 * so that if one of the messages exchanged during the
518 		 * initialization sequence exceeds the path mtu, it
519 		 * at least has a chance to get there. SCTP does no
520 		 * fragmentation of initialization messages.  The DF bit
521 		 * will be turned on again in sctp_send_cookie_echo()
522 		 * (but the cookie echo will still be sent with the df bit
523 		 * off).
524 		 */
525 		cur_fp->df = B_FALSE;
526 
527 		/* Mark this address as alive */
528 		cur_fp->state = SCTP_FADDRS_ALIVE;
529 
530 		/* This sctp_t is fully bound now. */
531 		sctp->sctp_connp->conn_fully_bound = B_TRUE;
532 
533 		/* Send the INIT to the peer */
534 		SCTP_FADDR_TIMER_RESTART(sctp, cur_fp, cur_fp->rto);
535 		/*
536 		 * sctp_init_mp() could result in modifying the source
537 		 * address list, so take the hash lock.
538 		 */
539 		mutex_enter(&tbf->tf_lock);
540 		initmp = sctp_init_mp(sctp);
541 		if (initmp == NULL) {
542 			mutex_exit(&tbf->tf_lock);
543 			WAKE_SCTP(sctp);
544 			/* let timer retry */
545 			return (0);
546 		}
547 		mutex_exit(&tbf->tf_lock);
548 		sctp->sctp_state = SCTPS_COOKIE_WAIT;
549 		/*
550 		 * On a clustered note send this notification to the clustering
551 		 * subsystem.
552 		 */
553 		if (cl_sctp_connect != NULL) {
554 			uchar_t		*slist;
555 			uchar_t		*flist;
556 			size_t		ssize;
557 			size_t		fsize;
558 
559 			fsize = sizeof (in6_addr_t) * sctp->sctp_nfaddrs;
560 			ssize = sizeof (in6_addr_t) * sctp->sctp_nsaddrs;
561 			slist = kmem_alloc(ssize, KM_SLEEP);
562 			flist = kmem_alloc(fsize, KM_SLEEP);
563 			/* The clustering module frees the lists */
564 			sctp_get_saddr_list(sctp, slist, ssize);
565 			sctp_get_faddr_list(sctp, flist, fsize);
566 			(*cl_sctp_connect)(sctp->sctp_family, slist,
567 			    sctp->sctp_nsaddrs, sctp->sctp_lport,
568 			    flist, sctp->sctp_nfaddrs, sctp->sctp_fport,
569 			    B_TRUE, (cl_sctp_handle_t)sctp);
570 		}
571 		WAKE_SCTP(sctp);
572 		/* OK to call IP_PUT() here instead of sctp_add_sendq(). */
573 		CONN_INC_REF(sctp->sctp_connp);
574 		initmp->b_flag |= MSGHASREF;
575 		IP_PUT(initmp, sctp->sctp_connp, sctp->sctp_current->isv4);
576 		BUMP_LOCAL(sctp->sctp_opkts);
577 
578 		sctp->sctp_ulp_prop(sctp->sctp_ulpd,
579 		    sctp_wroff_xtra + hdrlen + sizeof (sctp_data_hdr_t), 0);
580 
581 		return (0);
582 	default:
583 		ip0dbg(("sctp_connect: invalid state. %d\n", sctp->sctp_state));
584 		WAKE_SCTP(sctp);
585 		return (EINVAL);
586 	}
587 }
588