xref: /illumos-gate/usr/src/uts/common/inet/sctp/sctp_cookie.c (revision 814a60b13c0ad90e5d2edfd29a7a84bbf416cc1a)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2005 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/md5.h>
34 #include <sys/kmem.h>
35 #include <sys/strsubr.h>
36 #include <sys/random.h>
37 
38 #include <netinet/in.h>
39 #include <netinet/ip6.h>
40 
41 #include <inet/common.h>
42 #include <inet/ip.h>
43 #include <inet/ip6.h>
44 #include <inet/sctp_ip.h>
45 #include <inet/ipclassifier.h>
46 #include "sctp_impl.h"
47 
48 /*
49  * From RFC 2104. This should probably go into libmd5 (and while
50  * we're at it, maybe we should make a libdigest so we can later
51  * add SHA1 and others, esp. since some weaknesses have been found
52  * with MD5).
53  *
54  * text		IN			pointer to data stream
55  * text_len	IN			length of data stream
56  * key		IN			pointer to authentication key
57  * key_len	IN			length of authentication key
58  * digest	OUT			caller digest to be filled in
59  */
60 static void
61 hmac_md5(uchar_t *text, size_t text_len, uchar_t *key, size_t key_len,
62     uchar_t *digest)
63 {
64 	MD5_CTX context;
65 	uchar_t k_ipad[65];	/* inner padding - key XORd with ipad */
66 	uchar_t k_opad[65];	/* outer padding - key XORd with opad */
67 	uchar_t tk[16];
68 	int i;
69 
70 	/* if key is longer than 64 bytes reset it to key=MD5(key) */
71 	if (key_len > 64) {
72 		MD5_CTX tctx;
73 
74 		MD5Init(&tctx);
75 		MD5Update(&tctx, key, key_len);
76 		MD5Final(tk, &tctx);
77 
78 		key = tk;
79 		key_len = 16;
80 	}
81 
82 	/*
83 	 * the HMAC_MD5 transform looks like:
84 	 *
85 	 * MD5(K XOR opad, MD5(K XOR ipad, text))
86 	 *
87 	 * where K is an n byte key
88 	 * ipad is the byte 0x36 repeated 64 times
89 	 * opad is the byte 0x5c repeated 64 times
90 	 * and text is the data being protected
91 	 */
92 
93 	/* start out by storing key in pads */
94 	bzero(k_ipad, sizeof (k_ipad));
95 	bzero(k_opad, sizeof (k_opad));
96 	bcopy(key, k_ipad, key_len);
97 	bcopy(key, k_opad, key_len);
98 
99 	/* XOR key with ipad and opad values */
100 	for (i = 0; i < 64; i++) {
101 		k_ipad[i] ^= 0x36;
102 		k_opad[i] ^= 0x5c;
103 	}
104 	/*
105 	 * perform inner MD5
106 	 */
107 	MD5Init(&context);			/* init context for 1st */
108 						/* pass */
109 	MD5Update(&context, k_ipad, 64);	/* start with inner pad */
110 	MD5Update(&context, text, text_len);	/* then text of datagram */
111 	MD5Final(digest, &context);		/* finish up 1st pass */
112 	/*
113 	 * perform outer MD5
114 	 */
115 	MD5Init(&context);			/* init context for 2nd */
116 						/* pass */
117 	MD5Update(&context, k_opad, 64);	/* start with outer pad */
118 	MD5Update(&context, digest, 16);	/* then results of 1st */
119 						/* hash */
120 	MD5Final(digest, &context);		/* finish up 2nd pass */
121 }
122 
123 /*
124  * If inmp is non-NULL, and we need to abort, it will use the IP/SCTP
125  * info in initmp to send the abort. Otherwise, no abort will be sent.
126  * If errmp is non-NULL, a chain of unrecognized parameters will
127  * be created and returned via *errmp.
128  *
129  * Returns 1 if the parameters are OK (or there are no parameters), or
130  * 0 if not.
131  */
132 static int
133 validate_init_params(sctp_t *sctp, sctp_chunk_hdr_t *ch,
134     sctp_init_chunk_t *init, mblk_t *inmp, sctp_parm_hdr_t **want_cookie,
135     mblk_t **errmp, int *supp_af, uint_t *sctp_options)
136 {
137 	sctp_parm_hdr_t		*cph;
138 	sctp_init_chunk_t	*ic;
139 	ssize_t			remaining;
140 	uint16_t		serror = 0;
141 	char			*details = NULL;
142 	size_t			errlen = 0;
143 	boolean_t		got_cookie = B_FALSE;
144 	uint16_t		ptype;
145 
146 	*supp_af = 0;
147 
148 	if (sctp_options != NULL)
149 		*sctp_options = 0;
150 
151 	/* First validate stream parameters */
152 	if (init->sic_instr == 0 || init->sic_outstr == 0) {
153 		serror = SCTP_ERR_BAD_MANDPARM;
154 		dprint(1,
155 		    ("validate_init_params: bad sid, is=%d os=%d\n",
156 			htons(init->sic_instr), htons(init->sic_outstr)));
157 		goto abort;
158 	}
159 	if (ntohl(init->sic_inittag) == 0) {
160 		serror = SCTP_ERR_BAD_MANDPARM;
161 		dprint(1, ("validate_init_params: inittag = 0\n"));
162 		goto abort;
163 	}
164 
165 	remaining = ntohs(ch->sch_len) - sizeof (*ch);
166 	ic = (sctp_init_chunk_t *)(ch + 1);
167 	remaining -= sizeof (*ic);
168 	if (remaining < sizeof (*cph)) {
169 		/* Nothing to validate */
170 		if (want_cookie != NULL)
171 			goto cookie_abort;
172 		return (1);
173 	}
174 
175 	cph = (sctp_parm_hdr_t *)(ic + 1);
176 
177 	while (cph != NULL) {
178 		ptype = ntohs(cph->sph_type);
179 		switch (ptype) {
180 		case PARM_HBINFO:
181 		case PARM_UNRECOGNIZED:
182 		case PARM_ECN:
183 			/* just ignore them */
184 			break;
185 		case PARM_FORWARD_TSN:
186 			if (sctp_options != NULL)
187 				*sctp_options |= SCTP_PRSCTP_OPTION;
188 			break;
189 		case PARM_COOKIE:
190 			got_cookie = B_TRUE;
191 			if (want_cookie != NULL) {
192 				*want_cookie = cph;
193 			}
194 			break;
195 		case PARM_ADDR4:
196 		case PARM_ADDR6:
197 		case PARM_COOKIE_PRESERVE:
198 		case PARM_ADAPT_LAYER_IND:
199 			/* These are OK */
200 			break;
201 		case PARM_ADDR_HOST_NAME:
202 			/* Don't support this; abort the association */
203 			serror = SCTP_ERR_BAD_ADDR;
204 			details = (char *)cph;
205 			errlen = ntohs(cph->sph_len);
206 			dprint(1, ("sctp:validate_init_params: host addr\n"));
207 			goto abort;
208 		case PARM_SUPP_ADDRS: {
209 			/* Make sure we have a supported addr intersection */
210 			uint16_t *p, addrtype;
211 			int plen;
212 
213 			plen = ntohs(cph->sph_len);
214 			p = (uint16_t *)(cph + 1);
215 			while (plen > 0) {
216 				addrtype = ntohs(*p);
217 				switch (addrtype) {
218 				case PARM_ADDR6:
219 					*supp_af |= PARM_SUPP_V6;
220 					break;
221 				case PARM_ADDR4:
222 					*supp_af |= PARM_SUPP_V4;
223 					break;
224 				default:
225 					/*
226 					 * Do nothing, silently ignore hostname
227 					 * address.
228 					 */
229 					break;
230 				}
231 				p++;
232 				plen -= sizeof (*p);
233 			}
234 			/*
235 			 * Some sanity checks.  The following should not
236 			 * fail unless the other side is broken.
237 			 *
238 			 * 1. If there is no supported address type yet the
239 			 * supported address parameter is present, abort.
240 			 * 2. If this is a V4 endpoint but V4 address is not
241 			 * supported, abort.
242 			 * 3. If this is a V6 only endpoint but V6 address is
243 			 * not supported, abort.  This assumes that a V6
244 			 * endpoint can use both V4 and V6 addresses.
245 			 */
246 			if (*supp_af == 0 ||
247 			    (sctp->sctp_family == AF_INET &&
248 			    !(*supp_af & PARM_SUPP_V4)) ||
249 			    (sctp->sctp_family == AF_INET6 &&
250 			    !(*supp_af & PARM_SUPP_V6) &&
251 			    sctp->sctp_connp->conn_ipv6_v6only)) {
252 				dprint(1,
253 				("sctp:validate_init_params: no supp addr\n"));
254 				serror = SCTP_ERR_BAD_ADDR;
255 				goto abort;
256 			}
257 			break;
258 		}
259 		default:
260 			/* Unrecognized param; check the high order bits */
261 			if ((ptype & 0xc000) == 0xc000) {
262 				/*
263 				 * report unrecognized param, and
264 				 * keep processing
265 				 */
266 				if (errmp != NULL) {
267 					if (want_cookie != NULL) {
268 						*errmp = sctp_make_err(sctp,
269 						    PARM_UNRECOGNIZED,
270 						    (void *)cph,
271 						    ntohs(cph->sph_len));
272 					} else {
273 						sctp_add_unrec_parm(cph, errmp);
274 					}
275 				}
276 				break;
277 			}
278 			if (ptype & 0x4000) {
279 				/*
280 				 * Stop processing and drop; report
281 				 * unrecognized param
282 				 */
283 				serror = SCTP_ERR_UNREC_PARM;
284 				details = (char *)cph;
285 				errlen = ntohs(cph->sph_len);
286 				goto abort;
287 			}
288 			if (ptype & 0x8000) {
289 				/* skip and continue processing */
290 				break;
291 			}
292 
293 			/*
294 			 * 2 high bits are clear; stop processing and
295 			 * drop packet
296 			 */
297 			return (0);
298 		}
299 
300 		cph = sctp_next_parm(cph, &remaining);
301 	}
302 
303 	if (want_cookie != NULL && !got_cookie) {
304 cookie_abort:
305 		dprint(1, ("validate_init_params: cookie absent\n"));
306 		sctp_send_abort(sctp, sctp_init2vtag(ch), SCTP_ERR_MISSING_PARM,
307 		    details, errlen, inmp, 0, B_FALSE);
308 		return (0);
309 	}
310 
311 	/* OK */
312 	return (1);
313 
314 abort:
315 	if (want_cookie != NULL)
316 		return (0);
317 
318 	sctp_send_abort(sctp, sctp_init2vtag(ch), serror, details,
319 	    errlen, inmp, 0, B_FALSE);
320 	return (0);
321 }
322 
323 /*
324  * Initialize params from the INIT and INIT-ACK when the assoc. is
325  * established.
326  */
327 boolean_t
328 sctp_initialize_params(sctp_t *sctp, sctp_init_chunk_t *init,
329     sctp_init_chunk_t *iack)
330 {
331 	/* Get initial TSN */
332 	sctp->sctp_ftsn = ntohl(init->sic_inittsn);
333 	sctp->sctp_lastacked = sctp->sctp_ftsn - 1;
334 
335 	/* Serial number is initialized to the same value as the TSN */
336 	sctp->sctp_fcsn = sctp->sctp_lastacked;
337 
338 	/*
339 	 * Get verification tags; no byteordering is necessary, since
340 	 * verfication tags are never processed except for byte-by-byte
341 	 * comparisons.
342 	 */
343 	sctp->sctp_fvtag = init->sic_inittag;
344 	sctp->sctp_sctph->sh_verf = init->sic_inittag;
345 	sctp->sctp_sctph6->sh_verf = init->sic_inittag;
346 	sctp->sctp_lvtag = iack->sic_inittag;
347 
348 	/* Get the peer's rwnd */
349 	sctp->sctp_frwnd = ntohl(init->sic_a_rwnd);
350 
351 	/* Allocate the in/out-stream counters */
352 	sctp->sctp_num_ostr = iack->sic_outstr;
353 	sctp->sctp_ostrcntrs = kmem_zalloc(sizeof (uint16_t) *
354 	    sctp->sctp_num_ostr, KM_NOSLEEP);
355 	if (sctp->sctp_ostrcntrs == NULL)
356 		return (B_FALSE);
357 
358 	sctp->sctp_num_istr = iack->sic_instr;
359 	sctp->sctp_instr = kmem_zalloc(sizeof (*sctp->sctp_instr) *
360 	    sctp->sctp_num_istr, KM_NOSLEEP);
361 	if (sctp->sctp_instr == NULL) {
362 		kmem_free(sctp->sctp_ostrcntrs, sizeof (uint16_t) *
363 		    sctp->sctp_num_ostr);
364 		sctp->sctp_ostrcntrs = NULL;
365 		return (B_FALSE);
366 	}
367 	return (B_TRUE);
368 }
369 
370 #define	SCTP_CALC_COOKIE_LEN(initcp) \
371 	sizeof (int64_t) +		/* timestamp */			\
372 	sizeof (uint32_t) +		/* cookie lifetime */		\
373 	sizeof (sctp_init_chunk_t) +	/* INIT ACK */			\
374 	sizeof (in6_addr_t) +		/* peer's original source */ 	\
375 	ntohs((initcp)->sch_len) +	/* peer's INIT */		\
376 	sizeof (uint32_t) +		/* local tie-tag */		\
377 	sizeof (uint32_t) +		/* peer tie-tag */		\
378 	sizeof (sctp_parm_hdr_t) +	/* param header */		\
379 	16				/* MD5 hash */
380 
381 void
382 sctp_send_initack(sctp_t *sctp, sctp_chunk_hdr_t *ch, mblk_t *initmp)
383 {
384 	ipha_t			*initiph;
385 	ip6_t			*initip6h;
386 	ipha_t			*iackiph;
387 	ip6_t			*iackip6h;
388 	sctp_chunk_hdr_t	*iack_ch;
389 	sctp_init_chunk_t	*iack;
390 	sctp_init_chunk_t	*init;
391 	sctp_hdr_t		*iacksh;
392 	sctp_hdr_t		*initsh;
393 	size_t			cookielen;
394 	size_t			iacklen;
395 	size_t			ipsctplen;
396 	size_t			errlen = 0;
397 	sctp_parm_hdr_t		*cookieph;
398 	mblk_t			*iackmp;
399 	uint32_t		itag;
400 	uint32_t		itsn;
401 	int64_t			*now;
402 	int64_t			nowt;
403 	uint32_t		*lifetime;
404 	char			*p;
405 	boolean_t		 isv4;
406 	int			supp_af;
407 	uint_t			sctp_options;
408 	uint32_t		*ttag;
409 	int			pad;
410 	mblk_t			*errmp = NULL;
411 	boolean_t		initcollision = B_FALSE;
412 
413 	BUMP_LOCAL(sctp->sctp_ibchunks);
414 	isv4 = (IPH_HDR_VERSION(initmp->b_rptr) == IPV4_VERSION);
415 
416 	/* Extract the INIT chunk */
417 	if (isv4) {
418 		initiph = (ipha_t *)initmp->b_rptr;
419 		initsh = (sctp_hdr_t *)((char *)initiph +
420 		    IPH_HDR_LENGTH(initmp->b_rptr));
421 		ipsctplen = sctp->sctp_ip_hdr_len;
422 	} else {
423 		initip6h = (ip6_t *)initmp->b_rptr;
424 		initsh = (sctp_hdr_t *)(initip6h + 1);
425 		ipsctplen = sctp->sctp_ip_hdr6_len;
426 	}
427 	ASSERT(OK_32PTR(initsh));
428 	init = (sctp_init_chunk_t *)((char *)(initsh + 1) + sizeof (*iack_ch));
429 
430 	/* Make sure we like the peer's parameters */
431 	if (validate_init_params(sctp, ch, init, initmp, NULL, &errmp,
432 		&supp_af, &sctp_options) == 0) {
433 		return;
434 	}
435 	if (errmp != NULL)
436 		errlen = msgdsize(errmp);
437 	if (sctp->sctp_family == AF_INET) {
438 		/*
439 		 * Irregardless of the supported address in the INIT, v4
440 		 * must be supported.
441 		 */
442 		supp_af = PARM_SUPP_V4;
443 	} else {
444 		/*
445 		 * No supported addresses parameter in INIT.  Assume
446 		 * both v4 and v6 are supported.
447 		 */
448 		if (supp_af == 0) {
449 			supp_af = PARM_SUPP_V6 | PARM_SUPP_V4;
450 		}
451 	}
452 	if (sctp->sctp_state <= SCTPS_LISTEN) {
453 		/* normal, expected INIT: generate new vtag and itsn */
454 		(void) random_get_pseudo_bytes((uint8_t *)&itag, sizeof (itag));
455 		if (itag == 0)
456 			itag = (uint32_t)gethrtime();
457 		itsn = itag + 1;
458 		itag = htonl(itag);
459 	} else if (sctp->sctp_state == SCTPS_COOKIE_WAIT ||
460 	    sctp->sctp_state == SCTPS_COOKIE_ECHOED) {
461 		/* init collision; copy vtag and itsn from sctp */
462 		itag = sctp->sctp_lvtag;
463 		itsn = sctp->sctp_ltsn;
464 		/*
465 		 * In addition we need to send all the params that was sent
466 		 * in our INIT chunk. Essentially, it is only the supported
467 		 * address params that we need to add.
468 		 */
469 		initcollision = B_TRUE;
470 	} else {
471 		/* peer restart; generate new vtag but keep everything else */
472 		(void) random_get_pseudo_bytes((uint8_t *)&itag, sizeof (itag));
473 		if (itag == 0)
474 			itag = (uint32_t)gethrtime();
475 		itag = htonl(itag);
476 		itsn = sctp->sctp_ltsn;
477 	}
478 
479 	/*
480 	 * Allocate a mblk for the INIT ACK, consisting of the link layer
481 	 * header, the IP header, the SCTP common header, and INIT ACK chunk,
482 	 * and finally the COOKIE parameter.
483 	 */
484 	cookielen = SCTP_CALC_COOKIE_LEN(ch);
485 	iacklen = sizeof (*iack_ch) + sizeof (*iack) + cookielen;
486 	if (sctp->sctp_send_adaption)
487 		iacklen += (sizeof (sctp_parm_hdr_t) + sizeof (uint32_t));
488 	if (((sctp_options & SCTP_PRSCTP_OPTION) || initcollision) &&
489 	    sctp->sctp_prsctp_aware && sctp_prsctp_enabled) {
490 		iacklen += sctp_options_param_len(sctp, SCTP_PRSCTP_OPTION);
491 	}
492 	if (initcollision)
493 		iacklen += sctp_supaddr_param_len(sctp);
494 	iacklen += sctp_addr_params_len(sctp, supp_af);
495 	ipsctplen += sizeof (*iacksh) + iacklen;
496 	iacklen += errlen;
497 	if ((pad = ipsctplen % 4) != 0) {
498 		pad = 4 - pad;
499 		ipsctplen += pad;
500 	}
501 	iackmp = allocb(ipsctplen + sctp_wroff_xtra, BPRI_MED);
502 	if (iackmp == NULL) {
503 		sctp_send_abort(sctp, sctp_init2vtag(ch),
504 		    SCTP_ERR_NO_RESOURCES, NULL, 0, initmp, 0, B_FALSE);
505 		return;
506 	}
507 
508 	/* Copy in the [imcomplete] IP/SCTP composite header */
509 	p = (char *)(iackmp->b_rptr + sctp_wroff_xtra);
510 	iackmp->b_rptr = (uchar_t *)p;
511 	if (isv4) {
512 		bcopy(sctp->sctp_iphc, p, sctp->sctp_hdr_len);
513 		iackiph = (ipha_t *)p;
514 
515 		/* Copy the peer's IP addr */
516 		iackiph->ipha_dst = initiph->ipha_src;
517 		iackiph->ipha_src = initiph->ipha_dst;
518 		iackiph->ipha_length = htons(ipsctplen + errlen);
519 		iacksh = (sctp_hdr_t *)(p + sctp->sctp_ip_hdr_len);
520 	} else {
521 		bcopy(sctp->sctp_iphc6, p, sctp->sctp_hdr6_len);
522 		iackip6h = (ip6_t *)p;
523 
524 		/* Copy the peer's IP addr */
525 		iackip6h->ip6_dst = initip6h->ip6_src;
526 		iackip6h->ip6_src = initip6h->ip6_dst;
527 		iackip6h->ip6_plen = htons(ipsctplen - sizeof (*iackip6h) +
528 		    errlen);
529 		iacksh = (sctp_hdr_t *)(p + sctp->sctp_ip_hdr6_len);
530 	}
531 	ASSERT(OK_32PTR(iacksh));
532 
533 	/* Fill in the holes in the SCTP common header */
534 	iacksh->sh_sport = initsh->sh_dport;
535 	iacksh->sh_dport = initsh->sh_sport;
536 	iacksh->sh_verf = init->sic_inittag;
537 
538 	/* INIT ACK chunk header */
539 	iack_ch = (sctp_chunk_hdr_t *)(iacksh + 1);
540 	iack_ch->sch_id = CHUNK_INIT_ACK;
541 	iack_ch->sch_flags = 0;
542 	iack_ch->sch_len = htons(iacklen);
543 
544 	/* The INIT ACK itself */
545 	iack = (sctp_init_chunk_t *)(iack_ch + 1);
546 	iack->sic_inittag = itag;	/* already in network byteorder */
547 	iack->sic_inittsn = htonl(itsn);
548 
549 	iack->sic_a_rwnd = htonl(sctp->sctp_rwnd);
550 	/* Advertise what we would want to have as stream #'s */
551 	iack->sic_outstr = htons(MIN(sctp->sctp_num_ostr,
552 	    ntohs(init->sic_instr)));
553 	iack->sic_instr = htons(sctp->sctp_num_istr);
554 
555 	p = (char *)(iack + 1);
556 	p += sctp_adaption_code_param(sctp, (uchar_t *)p);
557 	if (initcollision)
558 		p += sctp_supaddr_param(sctp, (uchar_t *)p);
559 	p += sctp_addr_params(sctp, supp_af, (uchar_t *)p);
560 	if (((sctp_options & SCTP_PRSCTP_OPTION) || initcollision) &&
561 	    sctp->sctp_prsctp_aware && sctp_prsctp_enabled) {
562 		p += sctp_options_param(sctp, p, SCTP_PRSCTP_OPTION);
563 	}
564 	/*
565 	 * Generate and lay in the COOKIE parameter.
566 	 *
567 	 * The cookie consists of:
568 	 * 1. The relative timestamp for the cookie (lbolt64)
569 	 * 2. The cookie lifetime (uint32_t) in tick
570 	 * 3. The local tie-tag
571 	 * 4. The peer tie-tag
572 	 * 5. Peer's original src, used to confirm the validity of address.
573 	 * 6. Our INIT ACK chunk, less any parameters
574 	 * 7. The INIT chunk (may contain parameters)
575 	 * 8. 128-bit MD5 signature.
576 	 *
577 	 * Since the timestamp values will only be evaluated locally, we
578 	 * don't need to worry about byte-ordering them.
579 	 */
580 	cookieph = (sctp_parm_hdr_t *)p;
581 	cookieph->sph_type = htons(PARM_COOKIE);
582 	cookieph->sph_len = htons(cookielen);
583 
584 	/* timestamp */
585 	now = (int64_t *)(cookieph + 1);
586 	nowt = lbolt64;
587 	bcopy(&nowt, now, sizeof (*now));
588 
589 	/* cookie lifetime -- need configuration */
590 	lifetime = (uint32_t *)(now + 1);
591 	*lifetime = sctp->sctp_cookie_lifetime;
592 
593 	/* Set the tie-tags */
594 	ttag = (uint32_t *)(lifetime + 1);
595 	if (sctp->sctp_state <= SCTPS_COOKIE_WAIT) {
596 		*ttag = 0;
597 		ttag++;
598 		*ttag = 0;
599 		ttag++;
600 	} else {
601 		/* local tie-tag (network byte-order) */
602 		*ttag = sctp->sctp_lvtag;
603 		ttag++;
604 		/* peer tie-tag (network byte-order) */
605 		*ttag = sctp->sctp_fvtag;
606 		ttag++;
607 	}
608 	/*
609 	 * Copy in peer's original source address so that we can confirm
610 	 * the reachability later.
611 	 */
612 	p = (char *)ttag;
613 	if (isv4) {
614 		in6_addr_t peer_addr;
615 
616 		IN6_IPADDR_TO_V4MAPPED(iackiph->ipha_dst, &peer_addr);
617 		bcopy(&peer_addr, p, sizeof (in6_addr_t));
618 	} else {
619 		bcopy(&iackip6h->ip6_dst, p, sizeof (in6_addr_t));
620 	}
621 	p += sizeof (in6_addr_t);
622 	/* Copy in our INIT ACK chunk */
623 	bcopy(iack, p, sizeof (*iack));
624 	iack = (sctp_init_chunk_t *)p;
625 	/* Set the # of streams we'll end up using */
626 	iack->sic_outstr = MIN(sctp->sctp_num_ostr, ntohs(init->sic_instr));
627 	iack->sic_instr = MIN(sctp->sctp_num_istr, ntohs(init->sic_outstr));
628 	p += sizeof (*iack);
629 
630 	/* Copy in the peer's INIT chunk */
631 	bcopy(ch, p, ntohs(ch->sch_len));
632 	p += ntohs(ch->sch_len);
633 
634 	/*
635 	 * Calculate the HMAC ICV into the digest slot in buf.
636 	 * First, generate a new secret if the current secret is
637 	 * older than the new secret lifetime parameter permits,
638 	 * copying the current secret to sctp_old_secret.
639 	 */
640 	if (sctp_new_secret_interval > 0 &&
641 	    (sctp->sctp_last_secret_update +
642 	    MSEC_TO_TICK(sctp_new_secret_interval)) <= nowt) {
643 		bcopy(sctp->sctp_secret, sctp->sctp_old_secret,
644 		    SCTP_SECRET_LEN);
645 		(void) random_get_pseudo_bytes(sctp->sctp_secret,
646 		    SCTP_SECRET_LEN);
647 		sctp->sctp_last_secret_update = nowt;
648 	}
649 
650 	hmac_md5((uchar_t *)now, cookielen - sizeof (*cookieph) - 16,
651 	    (uchar_t *)sctp->sctp_secret, SCTP_SECRET_LEN, (uchar_t *)p);
652 
653 	iackmp->b_wptr = iackmp->b_rptr + ipsctplen;
654 	iackmp->b_cont = errmp;		/*  OK if NULL */
655 
656 	/*
657 	 * Stash the conn ptr info. for IP only as e don't have any
658 	 * cached IRE.
659 	 */
660 	SCTP_STASH_IPINFO(iackmp, (ire_t *)NULL);
661 
662 	/* XXX sctp == sctp_g_q, so using its obchunks is valid */
663 	BUMP_LOCAL(sctp->sctp_opkts);
664 	BUMP_LOCAL(sctp->sctp_obchunks);
665 
666 	/* OK to call IP_PUT() here instead of sctp_add_sendq(). */
667 	CONN_INC_REF(sctp->sctp_connp);
668 	iackmp->b_flag |= MSGHASREF;
669 	IP_PUT(iackmp, sctp->sctp_connp, isv4);
670 }
671 
672 void
673 sctp_send_cookie_ack(sctp_t *sctp)
674 {
675 	sctp_chunk_hdr_t *cach;
676 	mblk_t *camp;
677 
678 	camp = sctp_make_mp(sctp, NULL, sizeof (*cach));
679 	if (camp == NULL) {
680 		/* XXX should abort, but don't have the inmp anymore */
681 		return;
682 	}
683 
684 	cach = (sctp_chunk_hdr_t *)camp->b_wptr;
685 	camp->b_wptr = (uchar_t *)(cach + 1);
686 	cach->sch_id = CHUNK_COOKIE_ACK;
687 	cach->sch_flags = 0;
688 	cach->sch_len = htons(sizeof (*cach));
689 
690 	sctp_set_iplen(sctp, camp);
691 
692 	BUMP_LOCAL(sctp->sctp_obchunks);
693 
694 	sctp_add_sendq(sctp, camp);
695 }
696 
697 static int
698 sctp_find_al_ind(sctp_parm_hdr_t *sph, ssize_t len, uint32_t *adaption_code)
699 {
700 
701 	if (len < sizeof (*sph))
702 		return (-1);
703 	while (sph != NULL) {
704 		if (sph->sph_type == htons(PARM_ADAPT_LAYER_IND) &&
705 		    ntohs(sph->sph_len) >= (sizeof (*sph) +
706 			sizeof (uint32_t))) {
707 			*adaption_code = *(uint32_t *)(sph + 1);
708 			return (0);
709 		}
710 		sph = sctp_next_parm(sph, &len);
711 	}
712 	return (-1);
713 }
714 
715 void
716 sctp_send_cookie_echo(sctp_t *sctp, sctp_chunk_hdr_t *iackch, mblk_t *iackmp)
717 {
718 	mblk_t			*cemp;
719 	mblk_t			*mp = NULL;
720 	mblk_t			*head;
721 	mblk_t			*meta;
722 	sctp_faddr_t		*fp;
723 	sctp_chunk_hdr_t	*cech;
724 	sctp_init_chunk_t	 *iack;
725 	int32_t			cansend;
726 	int32_t			seglen;
727 	size_t			ceclen;
728 	sctp_parm_hdr_t		*cph;
729 	sctp_data_hdr_t		*sdc;
730 	sctp_tf_t		*tf;
731 	int			pad;
732 	int			hdrlen;
733 	mblk_t			*errmp = NULL;
734 	uint_t			sctp_options;
735 	int			error;
736 	uint16_t		old_num_str;
737 
738 	iack = (sctp_init_chunk_t *)(iackch + 1);
739 
740 	cph = NULL;
741 	if (validate_init_params(sctp, iackch, iack, iackmp, &cph, &errmp,
742 	    &pad, &sctp_options) == 0) { /* result in 'pad' ignored */
743 		BUMP_MIB(&sctp_mib, sctpAborted);
744 		sctp_assoc_event(sctp, SCTP_CANT_STR_ASSOC, 0, NULL);
745 		sctp_clean_death(sctp, ECONNABORTED);
746 		return;
747 	}
748 	ASSERT(cph != NULL);
749 
750 	ASSERT(sctp->sctp_cookie_mp == NULL);
751 
752 	/* Got a cookie to echo back; allocate an mblk */
753 	ceclen = sizeof (*cech) + ntohs(cph->sph_len) - sizeof (*cph);
754 	if ((pad = ceclen & (SCTP_ALIGN - 1)) != 0)
755 		pad = SCTP_ALIGN - pad;
756 
757 	if (IPH_HDR_VERSION(iackmp->b_rptr) == IPV4_VERSION)
758 		hdrlen = sctp->sctp_hdr_len;
759 	else
760 		hdrlen = sctp->sctp_hdr6_len;
761 
762 	cemp = allocb(sctp_wroff_xtra + hdrlen + ceclen + pad, BPRI_MED);
763 	if (cemp == NULL) {
764 		SCTP_FADDR_TIMER_RESTART(sctp, sctp->sctp_current,
765 		    sctp->sctp_current->rto);
766 		if (errmp != NULL)
767 			freeb(errmp);
768 		return;
769 	}
770 	cemp->b_rptr += (sctp_wroff_xtra + hdrlen);
771 
772 	/* Process the INIT ACK */
773 	sctp->sctp_sctph->sh_verf = iack->sic_inittag;
774 	sctp->sctp_sctph6->sh_verf = iack->sic_inittag;
775 	sctp->sctp_fvtag = iack->sic_inittag;
776 	sctp->sctp_ftsn = ntohl(iack->sic_inittsn);
777 	sctp->sctp_lastacked = sctp->sctp_ftsn - 1;
778 	sctp->sctp_fcsn = sctp->sctp_lastacked;
779 	sctp->sctp_frwnd = ntohl(iack->sic_a_rwnd);
780 
781 	/*
782 	 * Populate sctp with addresses given in the INIT ACK or IP header.
783 	 * Need to set the df bit in the current fp as it has been cleared
784 	 * in sctp_connect().
785 	 */
786 	sctp->sctp_current->df = B_TRUE;
787 	/*
788 	 * Since IP uses this info during the fanout process, we need to hold
789 	 * the lock for this hash line while performing this operation.
790 	 */
791 	/* XXX sctp_conn_fanout + SCTP_CONN_HASH(sctp->sctp_ports); */
792 	ASSERT(sctp->sctp_conn_tfp != NULL);
793 	tf = sctp->sctp_conn_tfp;
794 	/* sctp isn't a listener so only need to hold conn fanout lock */
795 	mutex_enter(&tf->tf_lock);
796 	if (sctp_get_addrparams(sctp, NULL, iackmp, iackch, NULL) != 0) {
797 		mutex_exit(&tf->tf_lock);
798 		freeb(cemp);
799 		SCTP_FADDR_TIMER_RESTART(sctp, sctp->sctp_current,
800 		    sctp->sctp_current->rto);
801 		if (errmp != NULL)
802 			freeb(errmp);
803 		return;
804 	}
805 	mutex_exit(&tf->tf_lock);
806 
807 	fp = sctp->sctp_current;
808 
809 	/*
810 	 * There could be a case when we get an INIT-ACK again, if the INIT
811 	 * is re-transmitted, for e.g., which means we would have already
812 	 * allocated this resource earlier (also for sctp_instr). In this
813 	 * case we check and re-allocate, if necessary.
814 	 */
815 	old_num_str = sctp->sctp_num_ostr;
816 	if (ntohs(iack->sic_instr) < sctp->sctp_num_ostr)
817 		sctp->sctp_num_ostr = ntohs(iack->sic_instr);
818 	if (sctp->sctp_ostrcntrs == NULL) {
819 		sctp->sctp_ostrcntrs = kmem_zalloc(sizeof (uint16_t) *
820 		    sctp->sctp_num_ostr, KM_NOSLEEP);
821 	} else {
822 		ASSERT(old_num_str > 0);
823 		if (old_num_str != sctp->sctp_num_ostr) {
824 			kmem_free(sctp->sctp_ostrcntrs, sizeof (uint16_t) *
825 			    old_num_str);
826 			sctp->sctp_ostrcntrs = kmem_zalloc(sizeof (uint16_t) *
827 			    sctp->sctp_num_ostr, KM_NOSLEEP);
828 		}
829 	}
830 	if (sctp->sctp_ostrcntrs == NULL) {
831 		freeb(cemp);
832 		SCTP_FADDR_TIMER_RESTART(sctp, fp, fp->rto);
833 		if (errmp != NULL)
834 			freeb(errmp);
835 		return;
836 	}
837 
838 	/*
839 	 * Allocate the in stream tracking array. Comments for sctp_ostrcntrs
840 	 * hold here too.
841 	 */
842 	old_num_str = sctp->sctp_num_istr;
843 	if (ntohs(iack->sic_outstr) < sctp->sctp_num_istr)
844 		sctp->sctp_num_istr = ntohs(iack->sic_outstr);
845 	if (sctp->sctp_instr == NULL) {
846 		sctp->sctp_instr = kmem_zalloc(sizeof (*sctp->sctp_instr) *
847 		    sctp->sctp_num_istr, KM_NOSLEEP);
848 	} else {
849 		ASSERT(old_num_str > 0);
850 		if (old_num_str != sctp->sctp_num_istr) {
851 			kmem_free(sctp->sctp_instr,
852 			    sizeof (*sctp->sctp_instr) * old_num_str);
853 			sctp->sctp_instr = kmem_zalloc(
854 			    sizeof (*sctp->sctp_instr) * sctp->sctp_num_istr,
855 			    KM_NOSLEEP);
856 		}
857 	}
858 	if (sctp->sctp_instr == NULL) {
859 		kmem_free(sctp->sctp_ostrcntrs,
860 		    sizeof (uint16_t) * sctp->sctp_num_ostr);
861 		freeb(cemp);
862 		SCTP_FADDR_TIMER_RESTART(sctp, fp, fp->rto);
863 		if (errmp != NULL)
864 			freeb(errmp);
865 		return;
866 	}
867 
868 	if (!(sctp_options & SCTP_PRSCTP_OPTION) && sctp->sctp_prsctp_aware)
869 		sctp->sctp_prsctp_aware = B_FALSE;
870 
871 	if (sctp_find_al_ind((sctp_parm_hdr_t *)(iack + 1),
872 		ntohs(iackch->sch_len) - (sizeof (*iackch) + sizeof (*iack)),
873 		&sctp->sctp_rx_adaption_code) == 0) {
874 		sctp->sctp_recv_adaption = 1;
875 	}
876 
877 	cech = (sctp_chunk_hdr_t *)cemp->b_rptr;
878 	ASSERT(OK_32PTR(cech));
879 	cech->sch_id = CHUNK_COOKIE;
880 	cech->sch_flags = 0;
881 	cech->sch_len = htons(ceclen);
882 
883 	/* Copy the cookie (less the parm hdr) to the chunk */
884 	bcopy(cph + 1, cech + 1, ceclen - sizeof (*cph));
885 
886 	cemp->b_wptr = cemp->b_rptr + ceclen;
887 
888 	if (sctp->sctp_unsent > 0) {
889 		sctp_msg_hdr_t	*smh;
890 		mblk_t		*prev = NULL;
891 		uint32_t	unsent = 0;
892 
893 		mp = sctp->sctp_xmit_unsent;
894 		do {
895 			smh = (sctp_msg_hdr_t *)mp->b_rptr;
896 			if (smh->smh_sid >= sctp->sctp_num_ostr) {
897 				unsent += smh->smh_msglen;
898 				if (prev != NULL)
899 					prev->b_next = mp->b_next;
900 				else
901 					sctp->sctp_xmit_unsent = mp->b_next;
902 				mp->b_next = NULL;
903 				sctp_sendfail_event(sctp, mp, SCTP_ERR_BAD_SID,
904 				    B_FALSE);
905 				if (prev != NULL)
906 					mp = prev->b_next;
907 				else
908 					mp = sctp->sctp_xmit_unsent;
909 			} else {
910 				prev = mp;
911 				mp = mp->b_next;
912 			}
913 		} while (mp != NULL);
914 		if (unsent > 0) {
915 			ASSERT(sctp->sctp_unsent >= unsent);
916 			sctp->sctp_unsent -= unsent;
917 			/*
918 			 * Update ULP the amount of queued data, which is
919 			 * sent-unack'ed + unsent.
920 			 * This is not necessary, but doesn't harm, we
921 			 * just use unsent instead of sent-unack'ed +
922 			 * unsent, since there won't be any sent-unack'ed
923 			 * here.
924 			 */
925 			if (!SCTP_IS_DETACHED(sctp)) {
926 				sctp->sctp_ulp_xmitted(sctp->sctp_ulpd,
927 				    sctp->sctp_unsent);
928 			}
929 		}
930 		if (sctp->sctp_xmit_unsent == NULL)
931 			sctp->sctp_xmit_unsent_tail = NULL;
932 	}
933 	ceclen += pad;
934 	cansend = MIN(sctp->sctp_unsent, sctp->sctp_frwnd);
935 	meta = sctp_get_msg_to_send(sctp, &mp, NULL, &error, ceclen,
936 	    cansend,  NULL);
937 	/*
938 	 * The error cannot be anything else since we could have an non-zero
939 	 * error only if sctp_get_msg_to_send() tries to send a Forward
940 	 * TSN which will not happen here.
941 	 */
942 	ASSERT(error == 0);
943 	if (meta == NULL)
944 		goto sendcookie;
945 	sctp->sctp_xmit_tail = meta;
946 	sdc = (sctp_data_hdr_t *)mp->b_rptr;
947 	seglen = ntohs(sdc->sdh_len);
948 	if ((ceclen + seglen) > fp->sfa_pmss ||
949 	    (seglen - sizeof (*sdc)) > cansend) {
950 		goto sendcookie;
951 	}
952 	/* OK, if this fails */
953 	cemp->b_cont = dupmsg(mp);
954 sendcookie:
955 	head = sctp_add_proto_hdr(sctp, fp, cemp, 0, NULL);
956 	if (head == NULL) {
957 		freemsg(cemp);
958 		SCTP_FADDR_TIMER_RESTART(sctp, fp, fp->rto);
959 		if (errmp != NULL)
960 			freeb(errmp);
961 		return;
962 	}
963 	/*
964 	 * Even if cookie-echo exceeds MTU for one of the hops, it'll
965 	 * have a chance of getting there.
966 	 */
967 	if (fp->isv4) {
968 		ipha_t *iph = (ipha_t *)head->b_rptr;
969 		iph->ipha_fragment_offset_and_flags = 0;
970 	}
971 	BUMP_LOCAL(sctp->sctp_obchunks);
972 
973 	sctp->sctp_cookie_mp = dupmsg(head);
974 	/* Don't bundle, we will just resend init if this cookie is lost. */
975 	if (sctp->sctp_cookie_mp == NULL) {
976 		if (cemp->b_cont != NULL) {
977 			freemsg(cemp->b_cont);
978 			cemp->b_cont = NULL;
979 		}
980 	} else if (cemp->b_cont != NULL) {
981 		ASSERT(mp != NULL && mp == meta->b_cont);
982 		SCTP_CHUNK_CLEAR_FLAGS(cemp->b_cont);
983 		cemp->b_wptr += pad;
984 		seglen -= sizeof (*sdc);
985 		SCTP_CHUNK_SENT(sctp, mp, sdc, fp, seglen, meta);
986 	}
987 	if (errmp != NULL)
988 		linkb(head, errmp);
989 	sctp->sctp_state = SCTPS_COOKIE_ECHOED;
990 	SCTP_FADDR_TIMER_RESTART(sctp, fp, fp->rto);
991 
992 	sctp_set_iplen(sctp, head);
993 	sctp_add_sendq(sctp, head);
994 }
995 
996 int
997 sctp_process_cookie(sctp_t *sctp, sctp_chunk_hdr_t *ch, mblk_t *cmp,
998     sctp_init_chunk_t **iackpp, sctp_hdr_t *insctph, int *recv_adaption,
999     in6_addr_t *peer_addr)
1000 {
1001 	int32_t			clen;
1002 	size_t			initplen;
1003 	uchar_t			*p;
1004 	uchar_t			*given_hash;
1005 	uchar_t			needed_hash[16];
1006 	int64_t			ts;
1007 	int64_t			diff;
1008 	uint32_t		*lt;
1009 	sctp_init_chunk_t	*iack;
1010 	sctp_chunk_hdr_t	*initch;
1011 	sctp_init_chunk_t	*init;
1012 	uint32_t		*lttag;
1013 	uint32_t		*fttag;
1014 	uint32_t		ports;
1015 
1016 	BUMP_LOCAL(sctp->sctp_ibchunks);
1017 	/* Verify the ICV */
1018 	clen = ntohs(ch->sch_len) - sizeof (*ch) - 16;
1019 	if (clen < 0) {
1020 		dprint(1, ("invalid cookie chunk length %d\n",
1021 		    ntohs(ch->sch_len)));
1022 
1023 		return (-1);
1024 	}
1025 	p = (uchar_t *)(ch + 1);
1026 
1027 	hmac_md5(p, clen, (uchar_t *)sctp->sctp_secret, SCTP_SECRET_LEN,
1028 	    needed_hash);
1029 
1030 	/* The given hash follows the cookie data */
1031 	given_hash = p + clen;
1032 
1033 	if (bcmp(given_hash, needed_hash, 16) != 0) {
1034 		/* The secret may have changed; try the old secret */
1035 		hmac_md5(p, clen, (uchar_t *)sctp->sctp_old_secret,
1036 		    SCTP_SECRET_LEN, needed_hash);
1037 		if (bcmp(given_hash, needed_hash, 16) != 0) {
1038 			return (-1);
1039 		}
1040 	}
1041 
1042 	/* Timestamp is int64_t, and we only guarantee 32-bit alignment */
1043 	bcopy(p, &ts, sizeof (ts));
1044 	/* Cookie life time, int32_t */
1045 	lt = (uint32_t *)(p + sizeof (ts));
1046 
1047 	/*
1048 	 * To quote PRC, "this is our baby", so let's continue.
1049 	 * We need to pull out the encapsulated INIT ACK and
1050 	 * INIT chunks. Note that we don't process these until
1051 	 * we have verified the timestamp, but we need them before
1052 	 * processing the timestamp since if the time check fails,
1053 	 * we need to get the verification tag from the INIT in order
1054 	 * to send a stale cookie error.
1055 	 */
1056 	lttag = (uint32_t *)(lt + 1);
1057 	fttag = lttag + 1;
1058 	if (peer_addr != NULL)
1059 		bcopy(fttag + 1, peer_addr, sizeof (in6_addr_t));
1060 	iack = (sctp_init_chunk_t *)((char *)(fttag + 1) + sizeof (in6_addr_t));
1061 	initch = (sctp_chunk_hdr_t *)(iack + 1);
1062 	init = (sctp_init_chunk_t *)(initch + 1);
1063 	initplen = ntohs(initch->sch_len) - (sizeof (*init) + sizeof (*initch));
1064 	*iackpp = iack;
1065 	*recv_adaption = 0;
1066 
1067 	/* Check the timestamp */
1068 	diff = lbolt64 - ts;
1069 	if (diff > *lt && (init->sic_inittag != sctp->sctp_fvtag ||
1070 	    iack->sic_inittag != sctp->sctp_lvtag)) {
1071 
1072 		uint32_t staleness;
1073 
1074 		staleness = TICK_TO_USEC(diff);
1075 		staleness = htonl(staleness);
1076 		sctp_send_abort(sctp, init->sic_inittag, SCTP_ERR_STALE_COOKIE,
1077 		    (char *)&staleness, sizeof (staleness), cmp, 1, B_FALSE);
1078 
1079 		dprint(1, ("stale cookie %d\n", staleness));
1080 
1081 		return (-1);
1082 	}
1083 
1084 	/* Check for attack by adding addresses to a restart */
1085 	bcopy(insctph, &ports, sizeof (ports));
1086 	if (sctp_secure_restart_check(cmp, initch, ports, KM_NOSLEEP) != 1) {
1087 		return (-1);
1088 	}
1089 
1090 	/* Look for adaptation code if there any parms in the INIT chunk */
1091 	if ((initplen >= sizeof (sctp_parm_hdr_t)) &&
1092 	    (sctp_find_al_ind((sctp_parm_hdr_t *)(init + 1), initplen,
1093 	    &sctp->sctp_rx_adaption_code) == 0)) {
1094 		*recv_adaption = 1;
1095 	}
1096 
1097 	/* Examine tie-tags */
1098 
1099 	if (sctp->sctp_state >= SCTPS_COOKIE_WAIT) {
1100 		if (sctp->sctp_state == SCTPS_ESTABLISHED &&
1101 		    init->sic_inittag == sctp->sctp_fvtag &&
1102 		    iack->sic_inittag == sctp->sctp_lvtag &&
1103 		    *fttag == 0 && *lttag == 0) {
1104 
1105 			dprint(1, ("duplicate cookie from %x:%x:%x:%x (%d)\n",
1106 			    SCTP_PRINTADDR(sctp->sctp_current->faddr),
1107 			    (int)(sctp->sctp_fport)));
1108 			return (-1);
1109 		}
1110 
1111 		if (init->sic_inittag != sctp->sctp_fvtag &&
1112 		    iack->sic_inittag != sctp->sctp_lvtag &&
1113 		    *fttag == sctp->sctp_fvtag &&
1114 		    *lttag == sctp->sctp_lvtag) {
1115 			int i;
1116 
1117 			/* Section 5.2.4 case A: restart */
1118 			sctp->sctp_fvtag = init->sic_inittag;
1119 			sctp->sctp_lvtag = iack->sic_inittag;
1120 
1121 			sctp->sctp_sctph->sh_verf = init->sic_inittag;
1122 			sctp->sctp_sctph6->sh_verf = init->sic_inittag;
1123 
1124 			sctp->sctp_ftsn = ntohl(init->sic_inittsn);
1125 			sctp->sctp_lastacked = sctp->sctp_ftsn - 1;
1126 			sctp->sctp_frwnd = ntohl(init->sic_a_rwnd);
1127 			sctp->sctp_fcsn = sctp->sctp_lastacked;
1128 
1129 			if (sctp->sctp_state < SCTPS_ESTABLISHED) {
1130 				sctp->sctp_state = SCTPS_ESTABLISHED;
1131 				sctp->sctp_assoc_start_time = (uint32_t)lbolt;
1132 			}
1133 
1134 			dprint(1, ("sctp peer %x:%x:%x:%x (%d) restarted\n",
1135 			    SCTP_PRINTADDR(sctp->sctp_current->faddr),
1136 			    (int)(sctp->sctp_fport)));
1137 			/* reset parameters */
1138 			sctp_congest_reset(sctp);
1139 
1140 			/* reset stream bookkeeping */
1141 			sctp_instream_cleanup(sctp, B_FALSE);
1142 
1143 			sctp->sctp_istr_nmsgs = 0;
1144 			sctp->sctp_rxqueued = 0;
1145 			for (i = 0; i < sctp->sctp_num_ostr; i++) {
1146 				sctp->sctp_ostrcntrs[i] = 0;
1147 			}
1148 			/* XXX flush xmit_list? */
1149 
1150 			return (0);
1151 		} else if (init->sic_inittag != sctp->sctp_fvtag &&
1152 		    iack->sic_inittag == sctp->sctp_lvtag) {
1153 
1154 			/* Section 5.2.4 case B: INIT collision */
1155 			if (sctp->sctp_state < SCTPS_ESTABLISHED) {
1156 				if (!sctp_initialize_params(sctp, init, iack))
1157 					return (-1);	/* Drop? */
1158 				sctp->sctp_state = SCTPS_ESTABLISHED;
1159 				sctp->sctp_assoc_start_time = (uint32_t)lbolt;
1160 			}
1161 
1162 			dprint(1, ("init collision with %x:%x:%x:%x (%d)\n",
1163 			    SCTP_PRINTADDR(sctp->sctp_current->faddr),
1164 			    (int)(sctp->sctp_fport)));
1165 
1166 			return (0);
1167 		} else if (iack->sic_inittag != sctp->sctp_lvtag &&
1168 		    init->sic_inittag == sctp->sctp_fvtag &&
1169 		    *fttag == 0 && *lttag == 0) {
1170 
1171 			/* Section 5.2.4 case C: late COOKIE */
1172 			dprint(1, ("late cookie from %x:%x:%x:%x (%d)\n",
1173 			    SCTP_PRINTADDR(sctp->sctp_current->faddr),
1174 			    (int)(sctp->sctp_fport)));
1175 			return (-1);
1176 		} else if (init->sic_inittag == sctp->sctp_fvtag &&
1177 		    iack->sic_inittag == sctp->sctp_lvtag) {
1178 
1179 			/*
1180 			 * Section 5.2.4 case D: COOKIE ECHO retransmit
1181 			 * Don't check cookie lifetime
1182 			 */
1183 			dprint(1, ("cookie tags match from %x:%x:%x:%x (%d)\n",
1184 			    SCTP_PRINTADDR(sctp->sctp_current->faddr),
1185 			    (int)(sctp->sctp_fport)));
1186 			if (sctp->sctp_state < SCTPS_ESTABLISHED) {
1187 				if (!sctp_initialize_params(sctp, init, iack))
1188 					return (-1);	/* Drop? */
1189 				sctp->sctp_state = SCTPS_ESTABLISHED;
1190 				sctp->sctp_assoc_start_time = (uint32_t)lbolt;
1191 			}
1192 			return (0);
1193 		} else {
1194 			/* unrecognized case -- silently drop it */
1195 			return (-1);
1196 		}
1197 	}
1198 
1199 	return (0);
1200 }
1201 
1202 /*
1203  * Similar to ip_fanout_sctp, except that the src addr(s) are drawn
1204  * from address parameters in an INIT ACK's address list. This
1205  * function is used when an INIT ACK is received but IP's fanout
1206  * function could not find a sctp via the normal lookup routine.
1207  * This can happen when a host sends an INIT ACK from a different
1208  * address than the INIT was sent to.
1209  *
1210  * Returns the sctp_t if found, or NULL if not found.
1211  */
1212 sctp_t *
1213 sctp_addrlist2sctp(mblk_t *mp, sctp_hdr_t *sctph, sctp_chunk_hdr_t *ich,
1214     uint_t ipif_seqid, zoneid_t zoneid)
1215 {
1216 	int isv4;
1217 	ipha_t *iph;
1218 	ip6_t *ip6h;
1219 	in6_addr_t dst;
1220 	in6_addr_t src;
1221 	sctp_parm_hdr_t *ph;
1222 	ssize_t remaining;
1223 	sctp_init_chunk_t *iack;
1224 	uint32_t ports;
1225 	sctp_t *sctp = NULL;
1226 
1227 	ASSERT(ich->sch_id == CHUNK_INIT_ACK);
1228 
1229 	isv4 = (IPH_HDR_VERSION(mp->b_rptr) == IPV4_VERSION);
1230 	if (isv4) {
1231 		iph = (ipha_t *)mp->b_rptr;
1232 		IN6_IPADDR_TO_V4MAPPED(iph->ipha_dst, &dst);
1233 	} else {
1234 		ip6h = (ip6_t *)mp->b_rptr;
1235 		dst = ip6h->ip6_dst;
1236 	}
1237 
1238 	ports = *(uint32_t *)sctph;
1239 
1240 	dprint(1, ("sctp_addrlist2sctp: ports=%u, dst = %x:%x:%x:%x\n",
1241 	    ports, SCTP_PRINTADDR(dst)));
1242 
1243 	/* pull out any address parameters */
1244 	remaining = ntohs(ich->sch_len) - sizeof (*ich) - sizeof (*iack);
1245 	if (remaining < sizeof (*ph)) {
1246 		return (NULL);
1247 	}
1248 
1249 	iack = (sctp_init_chunk_t *)(ich + 1);
1250 	ph = (sctp_parm_hdr_t *)(iack + 1);
1251 
1252 	while (ph != NULL) {
1253 		/*
1254 		 * params have been put in host byteorder by
1255 		 * sctp_check_input()
1256 		 */
1257 		if (ph->sph_type == PARM_ADDR4) {
1258 			IN6_INADDR_TO_V4MAPPED((struct in_addr *)(ph + 1),
1259 			    &src);
1260 
1261 			sctp = sctp_conn_match(&src, &dst, ports, ipif_seqid,
1262 			    zoneid);
1263 
1264 			dprint(1,
1265 			    ("sctp_addrlist2sctp: src=%x:%x:%x:%x, sctp=%p\n",
1266 			    SCTP_PRINTADDR(src), sctp));
1267 
1268 
1269 			if (sctp != NULL) {
1270 				return (sctp);
1271 			}
1272 		} else if (ph->sph_type == PARM_ADDR6) {
1273 			src = *(in6_addr_t *)(ph + 1);
1274 			sctp = sctp_conn_match(&src, &dst, ports, ipif_seqid,
1275 			    zoneid);
1276 
1277 			dprint(1,
1278 			    ("sctp_addrlist2sctp: src=%x:%x:%x:%x, sctp=%p\n",
1279 			    SCTP_PRINTADDR(src), sctp));
1280 
1281 			if (sctp != NULL) {
1282 				return (sctp);
1283 			}
1284 		}
1285 
1286 		ph = sctp_next_parm(ph, &remaining);
1287 	}
1288 
1289 	return (NULL);
1290 }
1291