xref: /illumos-gate/usr/src/uts/common/inet/sctp/sctp_cookie.c (revision 8b80e8cb6855118d46f605e91b5ed4ce83417395)
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 2008 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 #include <sys/tsol/tnet.h>
38 
39 #include <netinet/in.h>
40 #include <netinet/ip6.h>
41 
42 #include <inet/common.h>
43 #include <inet/ip.h>
44 #include <inet/ip6.h>
45 #include <inet/sctp_ip.h>
46 #include <inet/ipclassifier.h>
47 #include "sctp_impl.h"
48 
49 /*
50  * Helper function for SunCluster (PSARC/2005/602) to get the original source
51  * address from the COOKIE
52  */
53 int cl_sctp_cookie_paddr(sctp_chunk_hdr_t *, in6_addr_t *);
54 
55 /*
56  * From RFC 2104. This should probably go into libmd5 (and while
57  * we're at it, maybe we should make a libdigest so we can later
58  * add SHA1 and others, esp. since some weaknesses have been found
59  * with MD5).
60  *
61  * text		IN			pointer to data stream
62  * text_len	IN			length of data stream
63  * key		IN			pointer to authentication key
64  * key_len	IN			length of authentication key
65  * digest	OUT			caller digest to be filled in
66  */
67 static void
68 hmac_md5(uchar_t *text, size_t text_len, uchar_t *key, size_t key_len,
69     uchar_t *digest)
70 {
71 	MD5_CTX context;
72 	uchar_t k_ipad[65];	/* inner padding - key XORd with ipad */
73 	uchar_t k_opad[65];	/* outer padding - key XORd with opad */
74 	uchar_t tk[16];
75 	int i;
76 
77 	/* if key is longer than 64 bytes reset it to key=MD5(key) */
78 	if (key_len > 64) {
79 		MD5_CTX tctx;
80 
81 		MD5Init(&tctx);
82 		MD5Update(&tctx, key, key_len);
83 		MD5Final(tk, &tctx);
84 
85 		key = tk;
86 		key_len = 16;
87 	}
88 
89 	/*
90 	 * the HMAC_MD5 transform looks like:
91 	 *
92 	 * MD5(K XOR opad, MD5(K XOR ipad, text))
93 	 *
94 	 * where K is an n byte key
95 	 * ipad is the byte 0x36 repeated 64 times
96 	 * opad is the byte 0x5c repeated 64 times
97 	 * and text is the data being protected
98 	 */
99 
100 	/* start out by storing key in pads */
101 	bzero(k_ipad, sizeof (k_ipad));
102 	bzero(k_opad, sizeof (k_opad));
103 	bcopy(key, k_ipad, key_len);
104 	bcopy(key, k_opad, key_len);
105 
106 	/* XOR key with ipad and opad values */
107 	for (i = 0; i < 64; i++) {
108 		k_ipad[i] ^= 0x36;
109 		k_opad[i] ^= 0x5c;
110 	}
111 	/*
112 	 * perform inner MD5
113 	 */
114 	MD5Init(&context);			/* init context for 1st */
115 						/* pass */
116 	MD5Update(&context, k_ipad, 64);	/* start with inner pad */
117 	MD5Update(&context, text, text_len);	/* then text of datagram */
118 	MD5Final(digest, &context);		/* finish up 1st pass */
119 	/*
120 	 * perform outer MD5
121 	 */
122 	MD5Init(&context);			/* init context for 2nd */
123 						/* pass */
124 	MD5Update(&context, k_opad, 64);	/* start with outer pad */
125 	MD5Update(&context, digest, 16);	/* then results of 1st */
126 						/* hash */
127 	MD5Final(digest, &context);		/* finish up 2nd pass */
128 }
129 
130 /*
131  * If inmp is non-NULL, and we need to abort, it will use the IP/SCTP
132  * info in initmp to send the abort. Otherwise, no abort will be sent.
133  * If errmp is non-NULL, a chain of unrecognized parameters will
134  * be created and returned via *errmp.
135  *
136  * Returns 1 if the parameters are OK (or there are no parameters), or
137  * 0 if not.
138  */
139 static int
140 validate_init_params(sctp_t *sctp, sctp_chunk_hdr_t *ch,
141     sctp_init_chunk_t *init, mblk_t *inmp, sctp_parm_hdr_t **want_cookie,
142     mblk_t **errmp, int *supp_af, uint_t *sctp_options)
143 {
144 	sctp_parm_hdr_t		*cph;
145 	sctp_init_chunk_t	*ic;
146 	ssize_t			remaining;
147 	uint16_t		serror = 0;
148 	char			*details = NULL;
149 	size_t			errlen = 0;
150 	boolean_t		got_cookie = B_FALSE;
151 	uint16_t		ptype;
152 
153 	if (sctp_options != NULL)
154 		*sctp_options = 0;
155 
156 	/* First validate stream parameters */
157 	if (init->sic_instr == 0 || init->sic_outstr == 0) {
158 		serror = SCTP_ERR_BAD_MANDPARM;
159 		dprint(1, ("validate_init_params: bad sid, is=%d os=%d\n",
160 		    htons(init->sic_instr), htons(init->sic_outstr)));
161 		goto abort;
162 	}
163 	if (ntohl(init->sic_inittag) == 0) {
164 		serror = SCTP_ERR_BAD_MANDPARM;
165 		dprint(1, ("validate_init_params: inittag = 0\n"));
166 		goto abort;
167 	}
168 
169 	remaining = ntohs(ch->sch_len) - sizeof (*ch);
170 	ic = (sctp_init_chunk_t *)(ch + 1);
171 	remaining -= sizeof (*ic);
172 	if (remaining < sizeof (*cph)) {
173 		/* Nothing to validate */
174 		if (want_cookie != NULL)
175 			goto cookie_abort;
176 		return (1);
177 	}
178 
179 	cph = (sctp_parm_hdr_t *)(ic + 1);
180 
181 	while (cph != NULL) {
182 		ptype = ntohs(cph->sph_type);
183 		switch (ptype) {
184 		case PARM_HBINFO:
185 		case PARM_UNRECOGNIZED:
186 		case PARM_ECN:
187 			/* just ignore them */
188 			break;
189 		case PARM_FORWARD_TSN:
190 			if (sctp_options != NULL)
191 				*sctp_options |= SCTP_PRSCTP_OPTION;
192 			break;
193 		case PARM_COOKIE:
194 			got_cookie = B_TRUE;
195 			if (want_cookie != NULL) {
196 				*want_cookie = cph;
197 			}
198 			break;
199 		case PARM_ADDR4:
200 			*supp_af |= PARM_SUPP_V4;
201 			break;
202 		case PARM_ADDR6:
203 			*supp_af |= PARM_SUPP_V6;
204 			break;
205 		case PARM_COOKIE_PRESERVE:
206 		case PARM_ADAPT_LAYER_IND:
207 			/* These are OK */
208 			break;
209 		case PARM_ADDR_HOST_NAME:
210 			/* Don't support this; abort the association */
211 			serror = SCTP_ERR_BAD_ADDR;
212 			details = (char *)cph;
213 			errlen = ntohs(cph->sph_len);
214 			dprint(1, ("sctp:validate_init_params: host addr\n"));
215 			goto abort;
216 		case PARM_SUPP_ADDRS: {
217 			/* Make sure we have a supported addr intersection */
218 			uint16_t *p, addrtype;
219 			int plen;
220 
221 			plen = ntohs(cph->sph_len);
222 			p = (uint16_t *)(cph + 1);
223 			while (plen > 0) {
224 				addrtype = ntohs(*p);
225 				switch (addrtype) {
226 				case PARM_ADDR6:
227 					*supp_af |= PARM_SUPP_V6;
228 					break;
229 				case PARM_ADDR4:
230 					*supp_af |= PARM_SUPP_V4;
231 					break;
232 				default:
233 					/*
234 					 * Do nothing, silently ignore hostname
235 					 * address.
236 					 */
237 					break;
238 				}
239 				p++;
240 				plen -= sizeof (*p);
241 			}
242 			break;
243 		}
244 		default:
245 			/* Unrecognized param; check the high order bits */
246 			if ((ptype & 0xc000) == 0xc000) {
247 				/*
248 				 * report unrecognized param, and
249 				 * keep processing
250 				 */
251 				if (errmp != NULL) {
252 					if (want_cookie != NULL) {
253 						*errmp = sctp_make_err(sctp,
254 						    PARM_UNRECOGNIZED,
255 						    (void *)cph,
256 						    ntohs(cph->sph_len));
257 					} else {
258 						sctp_add_unrec_parm(cph, errmp);
259 					}
260 				}
261 				break;
262 			}
263 			if (ptype & 0x4000) {
264 				/*
265 				 * Stop processing and drop; report
266 				 * unrecognized param
267 				 */
268 				serror = SCTP_ERR_UNREC_PARM;
269 				details = (char *)cph;
270 				errlen = ntohs(cph->sph_len);
271 				goto abort;
272 			}
273 			if (ptype & 0x8000) {
274 				/* skip and continue processing */
275 				break;
276 			}
277 
278 			/*
279 			 * 2 high bits are clear; stop processing and
280 			 * drop packet
281 			 */
282 			return (0);
283 		}
284 
285 		cph = sctp_next_parm(cph, &remaining);
286 	}
287 	/*
288 	 * Some sanity checks.  The following should not fail unless the
289 	 * other side is broken.
290 	 *
291 	 * 1. If this is a V4 endpoint but V4 address is not
292 	 * supported, abort.
293 	 * 2. If this is a V6 only endpoint but V6 address is
294 	 * not supported, abort.  This assumes that a V6
295 	 * endpoint can use both V4 and V6 addresses.
296 	 * We only care about supp_af when processing INIT, i.e want_cookie
297 	 * is NULL.
298 	 */
299 	if (want_cookie == NULL &&
300 	    ((sctp->sctp_family == AF_INET && !(*supp_af & PARM_SUPP_V4)) ||
301 	    (sctp->sctp_family == AF_INET6 && !(*supp_af & PARM_SUPP_V6) &&
302 	    sctp->sctp_connp->conn_ipv6_v6only))) {
303 		dprint(1, ("sctp:validate_init_params: supp addr\n"));
304 		serror = SCTP_ERR_BAD_ADDR;
305 		goto abort;
306 	}
307 
308 	if (want_cookie != NULL && !got_cookie) {
309 cookie_abort:
310 		dprint(1, ("validate_init_params: cookie absent\n"));
311 		sctp_send_abort(sctp, sctp_init2vtag(ch), SCTP_ERR_MISSING_PARM,
312 		    details, errlen, inmp, 0, B_FALSE);
313 		return (0);
314 	}
315 
316 	/* OK */
317 	return (1);
318 
319 abort:
320 	if (want_cookie != NULL)
321 		return (0);
322 
323 	sctp_send_abort(sctp, sctp_init2vtag(ch), serror, details,
324 	    errlen, inmp, 0, B_FALSE);
325 	return (0);
326 }
327 
328 /*
329  * Initialize params from the INIT and INIT-ACK when the assoc. is
330  * established.
331  */
332 boolean_t
333 sctp_initialize_params(sctp_t *sctp, sctp_init_chunk_t *init,
334     sctp_init_chunk_t *iack)
335 {
336 	/* Get initial TSN */
337 	sctp->sctp_ftsn = ntohl(init->sic_inittsn);
338 	sctp->sctp_lastacked = sctp->sctp_ftsn - 1;
339 
340 	/* Serial number is initialized to the same value as the TSN */
341 	sctp->sctp_fcsn = sctp->sctp_lastacked;
342 
343 	/*
344 	 * Get verification tags; no byteordering is necessary, since
345 	 * verfication tags are never processed except for byte-by-byte
346 	 * comparisons.
347 	 */
348 	sctp->sctp_fvtag = init->sic_inittag;
349 	sctp->sctp_sctph->sh_verf = init->sic_inittag;
350 	sctp->sctp_sctph6->sh_verf = init->sic_inittag;
351 	sctp->sctp_lvtag = iack->sic_inittag;
352 
353 	/* Get the peer's rwnd */
354 	sctp->sctp_frwnd = ntohl(init->sic_a_rwnd);
355 
356 	/* Allocate the in/out-stream counters */
357 	sctp->sctp_num_ostr = iack->sic_outstr;
358 	sctp->sctp_ostrcntrs = kmem_zalloc(sizeof (uint16_t) *
359 	    sctp->sctp_num_ostr, KM_NOSLEEP);
360 	if (sctp->sctp_ostrcntrs == NULL)
361 		return (B_FALSE);
362 
363 	sctp->sctp_num_istr = iack->sic_instr;
364 	sctp->sctp_instr = kmem_zalloc(sizeof (*sctp->sctp_instr) *
365 	    sctp->sctp_num_istr, KM_NOSLEEP);
366 	if (sctp->sctp_instr == NULL) {
367 		kmem_free(sctp->sctp_ostrcntrs, sizeof (uint16_t) *
368 		    sctp->sctp_num_ostr);
369 		sctp->sctp_ostrcntrs = NULL;
370 		return (B_FALSE);
371 	}
372 	return (B_TRUE);
373 }
374 
375 /*
376  * Copy the peer's original source address into addr. This relies on the
377  * following format (see sctp_send_initack() below):
378  * 	relative timestamp for the cookie (int64_t) +
379  * 	cookie lifetime (uint32_t) +
380  * 	local tie-tag (uint32_t) +  peer tie-tag (uint32_t) +
381  * 	Peer's original src ...
382  */
383 int
384 cl_sctp_cookie_paddr(sctp_chunk_hdr_t *ch, in6_addr_t *addr)
385 {
386 	uchar_t	*off;
387 
388 	ASSERT(addr != NULL);
389 
390 	if (ch->sch_id != CHUNK_COOKIE)
391 		return (EINVAL);
392 
393 	off = (uchar_t *)ch + sizeof (*ch) + sizeof (int64_t) +
394 	    sizeof (uint32_t) + sizeof (uint32_t) + sizeof (uint32_t);
395 
396 	bcopy(off, addr, sizeof (*addr));
397 
398 	return (0);
399 }
400 
401 #define	SCTP_CALC_COOKIE_LEN(initcp) \
402 	sizeof (int64_t) +		/* timestamp */			\
403 	sizeof (uint32_t) +		/* cookie lifetime */		\
404 	sizeof (sctp_init_chunk_t) +	/* INIT ACK */			\
405 	sizeof (in6_addr_t) +		/* peer's original source */ 	\
406 	ntohs((initcp)->sch_len) +	/* peer's INIT */		\
407 	sizeof (uint32_t) +		/* local tie-tag */		\
408 	sizeof (uint32_t) +		/* peer tie-tag */		\
409 	sizeof (sctp_parm_hdr_t) +	/* param header */		\
410 	16				/* MD5 hash */
411 
412 void
413 sctp_send_initack(sctp_t *sctp, sctp_hdr_t *initsh, sctp_chunk_hdr_t *ch,
414     mblk_t *initmp)
415 {
416 	ipha_t			*initiph;
417 	ip6_t			*initip6h;
418 	ipha_t			*iackiph;
419 	ip6_t			*iackip6h;
420 	sctp_chunk_hdr_t	*iack_ch;
421 	sctp_init_chunk_t	*iack;
422 	sctp_init_chunk_t	*init;
423 	sctp_hdr_t		*iacksh;
424 	size_t			cookielen;
425 	size_t			iacklen;
426 	size_t			ipsctplen;
427 	size_t			errlen = 0;
428 	sctp_parm_hdr_t		*cookieph;
429 	mblk_t			*iackmp;
430 	uint32_t		itag;
431 	uint32_t		itsn;
432 	int64_t			*now;
433 	int64_t			nowt;
434 	uint32_t		*lifetime;
435 	char			*p;
436 	boolean_t		 isv4;
437 	int			supp_af = 0;
438 	uint_t			sctp_options;
439 	uint32_t		*ttag;
440 	int			pad;
441 	mblk_t			*errmp = NULL;
442 	boolean_t		initcollision = B_FALSE;
443 	boolean_t		linklocal = B_FALSE;
444 	cred_t			*cr;
445 	ts_label_t		*initlabel;
446 	sctp_stack_t		*sctps = sctp->sctp_sctps;
447 
448 	BUMP_LOCAL(sctp->sctp_ibchunks);
449 	isv4 = (IPH_HDR_VERSION(initmp->b_rptr) == IPV4_VERSION);
450 
451 	/* Extract the INIT chunk */
452 	if (isv4) {
453 		initiph = (ipha_t *)initmp->b_rptr;
454 		ipsctplen = sctp->sctp_ip_hdr_len;
455 		supp_af |= PARM_SUPP_V4;
456 	} else {
457 		initip6h = (ip6_t *)initmp->b_rptr;
458 		ipsctplen = sctp->sctp_ip_hdr6_len;
459 		if (IN6_IS_ADDR_LINKLOCAL(&initip6h->ip6_src))
460 			linklocal = B_TRUE;
461 		supp_af |= PARM_SUPP_V6;
462 	}
463 	ASSERT(OK_32PTR(initsh));
464 	init = (sctp_init_chunk_t *)((char *)(initsh + 1) + sizeof (*iack_ch));
465 
466 	/* Make sure we like the peer's parameters */
467 	if (validate_init_params(sctp, ch, init, initmp, NULL, &errmp,
468 	    &supp_af, &sctp_options) == 0) {
469 		return;
470 	}
471 	if (errmp != NULL)
472 		errlen = msgdsize(errmp);
473 	if (sctp->sctp_family == AF_INET) {
474 		/*
475 		 * Irregardless of the supported address in the INIT, v4
476 		 * must be supported.
477 		 */
478 		supp_af = PARM_SUPP_V4;
479 	}
480 	if (sctp->sctp_state <= SCTPS_LISTEN) {
481 		/* normal, expected INIT: generate new vtag and itsn */
482 		(void) random_get_pseudo_bytes((uint8_t *)&itag, sizeof (itag));
483 		if (itag == 0)
484 			itag = (uint32_t)gethrtime();
485 		itsn = itag + 1;
486 		itag = htonl(itag);
487 	} else if (sctp->sctp_state == SCTPS_COOKIE_WAIT ||
488 	    sctp->sctp_state == SCTPS_COOKIE_ECHOED) {
489 		/* init collision; copy vtag and itsn from sctp */
490 		itag = sctp->sctp_lvtag;
491 		itsn = sctp->sctp_ltsn;
492 		/*
493 		 * In addition we need to send all the params that was sent
494 		 * in our INIT chunk. Essentially, it is only the supported
495 		 * address params that we need to add.
496 		 */
497 		initcollision = B_TRUE;
498 		/*
499 		 * When we sent the INIT, we should have set linklocal in
500 		 * the sctp which should be good enough.
501 		 */
502 		if (linklocal)
503 			linklocal = B_FALSE;
504 	} else {
505 		/* peer restart; generate new vtag but keep everything else */
506 		(void) random_get_pseudo_bytes((uint8_t *)&itag, sizeof (itag));
507 		if (itag == 0)
508 			itag = (uint32_t)gethrtime();
509 		itag = htonl(itag);
510 		itsn = sctp->sctp_ltsn;
511 	}
512 
513 	/*
514 	 * Allocate a mblk for the INIT ACK, consisting of the link layer
515 	 * header, the IP header, the SCTP common header, and INIT ACK chunk,
516 	 * and finally the COOKIE parameter.
517 	 */
518 	cookielen = SCTP_CALC_COOKIE_LEN(ch);
519 	iacklen = sizeof (*iack_ch) + sizeof (*iack) + cookielen;
520 	if (sctp->sctp_send_adaptation)
521 		iacklen += (sizeof (sctp_parm_hdr_t) + sizeof (uint32_t));
522 	if (((sctp_options & SCTP_PRSCTP_OPTION) || initcollision) &&
523 	    sctp->sctp_prsctp_aware && sctps->sctps_prsctp_enabled) {
524 		iacklen += sctp_options_param_len(sctp, SCTP_PRSCTP_OPTION);
525 	}
526 	if (initcollision)
527 		iacklen += sctp_supaddr_param_len(sctp);
528 	if (!linklocal)
529 		iacklen += sctp_addr_params(sctp, supp_af, NULL, B_FALSE);
530 	ipsctplen += sizeof (*iacksh) + iacklen;
531 	iacklen += errlen;
532 	if ((pad = ipsctplen % 4) != 0) {
533 		pad = 4 - pad;
534 		ipsctplen += pad;
535 	}
536 
537 	/*
538 	 * If the listen socket is bound to a trusted extensions
539 	 * multi-label port, attach a copy of the listener's cred
540 	 * to the new INITACK mblk. Modify the cred to contain
541 	 * the security label of the received INIT packet.
542 	 * If not a multi-label port, attach the unmodified
543 	 * listener's cred directly.
544 	 *
545 	 * We expect Sun developed kernel modules to properly set
546 	 * cred labels for sctp connections. We can't be so sure this
547 	 * will be done correctly when 3rd party kernel modules
548 	 * directly use sctp. The initlabel panic guard logic was
549 	 * added to cover this possibility.
550 	 */
551 	if (sctp->sctp_connp->conn_mlp_type != mlptSingle) {
552 		initlabel = MBLK_GETLABEL(initmp);
553 		if (initlabel == NULL) {
554 			sctp_send_abort(sctp, sctp_init2vtag(ch),
555 			    SCTP_ERR_UNKNOWN, NULL, 0, initmp, 0, B_FALSE);
556 			return;
557 		}
558 		cr = copycred_from_bslabel(CONN_CRED(sctp->sctp_connp),
559 		    &initlabel->tsl_label, initlabel->tsl_doi, KM_NOSLEEP);
560 		if (cr == NULL) {
561 			sctp_send_abort(sctp, sctp_init2vtag(ch),
562 			    SCTP_ERR_NO_RESOURCES, NULL, 0, initmp, 0, B_FALSE);
563 			return;
564 		}
565 		iackmp = allocb_cred(ipsctplen + sctps->sctps_wroff_xtra, cr);
566 		crfree(cr);
567 	} else {
568 		iackmp = allocb_cred(ipsctplen + sctps->sctps_wroff_xtra,
569 		    CONN_CRED(sctp->sctp_connp));
570 	}
571 	if (iackmp == NULL) {
572 		sctp_send_abort(sctp, sctp_init2vtag(ch),
573 		    SCTP_ERR_NO_RESOURCES, NULL, 0, initmp, 0, B_FALSE);
574 		return;
575 	}
576 
577 	/* Copy in the [imcomplete] IP/SCTP composite header */
578 	p = (char *)(iackmp->b_rptr + sctps->sctps_wroff_xtra);
579 	iackmp->b_rptr = (uchar_t *)p;
580 	if (isv4) {
581 		bcopy(sctp->sctp_iphc, p, sctp->sctp_hdr_len);
582 		iackiph = (ipha_t *)p;
583 
584 		/* Copy the peer's IP addr */
585 		iackiph->ipha_dst = initiph->ipha_src;
586 		iackiph->ipha_src = initiph->ipha_dst;
587 		iackiph->ipha_length = htons(ipsctplen + errlen);
588 		iacksh = (sctp_hdr_t *)(p + sctp->sctp_ip_hdr_len);
589 	} else {
590 		bcopy(sctp->sctp_iphc6, p, sctp->sctp_hdr6_len);
591 		iackip6h = (ip6_t *)p;
592 
593 		/* Copy the peer's IP addr */
594 		iackip6h->ip6_dst = initip6h->ip6_src;
595 		iackip6h->ip6_src = initip6h->ip6_dst;
596 		iackip6h->ip6_plen = htons(ipsctplen - sizeof (*iackip6h) +
597 		    errlen);
598 		iacksh = (sctp_hdr_t *)(p + sctp->sctp_ip_hdr6_len);
599 	}
600 	ASSERT(OK_32PTR(iacksh));
601 
602 	/* Fill in the holes in the SCTP common header */
603 	iacksh->sh_sport = initsh->sh_dport;
604 	iacksh->sh_dport = initsh->sh_sport;
605 	iacksh->sh_verf = init->sic_inittag;
606 
607 	/* INIT ACK chunk header */
608 	iack_ch = (sctp_chunk_hdr_t *)(iacksh + 1);
609 	iack_ch->sch_id = CHUNK_INIT_ACK;
610 	iack_ch->sch_flags = 0;
611 	iack_ch->sch_len = htons(iacklen);
612 
613 	/* The INIT ACK itself */
614 	iack = (sctp_init_chunk_t *)(iack_ch + 1);
615 	iack->sic_inittag = itag;	/* already in network byteorder */
616 	iack->sic_inittsn = htonl(itsn);
617 
618 	iack->sic_a_rwnd = htonl(sctp->sctp_rwnd);
619 	/* Advertise what we would want to have as stream #'s */
620 	iack->sic_outstr = htons(MIN(sctp->sctp_num_ostr,
621 	    ntohs(init->sic_instr)));
622 	iack->sic_instr = htons(sctp->sctp_num_istr);
623 
624 	p = (char *)(iack + 1);
625 	p += sctp_adaptation_code_param(sctp, (uchar_t *)p);
626 	if (initcollision)
627 		p += sctp_supaddr_param(sctp, (uchar_t *)p);
628 	if (!linklocal)
629 		p += sctp_addr_params(sctp, supp_af, (uchar_t *)p, B_FALSE);
630 	if (((sctp_options & SCTP_PRSCTP_OPTION) || initcollision) &&
631 	    sctp->sctp_prsctp_aware && sctps->sctps_prsctp_enabled) {
632 		p += sctp_options_param(sctp, p, SCTP_PRSCTP_OPTION);
633 	}
634 	/*
635 	 * Generate and lay in the COOKIE parameter.
636 	 *
637 	 * Any change here that results in a change of location for
638 	 * the peer's orig source address must be propagated to the fn
639 	 * cl_sctp_cookie_paddr() above.
640 	 *
641 	 * The cookie consists of:
642 	 * 1. The relative timestamp for the cookie (lbolt64)
643 	 * 2. The cookie lifetime (uint32_t) in tick
644 	 * 3. The local tie-tag
645 	 * 4. The peer tie-tag
646 	 * 5. Peer's original src, used to confirm the validity of address.
647 	 * 6. Our INIT ACK chunk, less any parameters
648 	 * 7. The INIT chunk (may contain parameters)
649 	 * 8. 128-bit MD5 signature.
650 	 *
651 	 * Since the timestamp values will only be evaluated locally, we
652 	 * don't need to worry about byte-ordering them.
653 	 */
654 	cookieph = (sctp_parm_hdr_t *)p;
655 	cookieph->sph_type = htons(PARM_COOKIE);
656 	cookieph->sph_len = htons(cookielen);
657 
658 	/* timestamp */
659 	now = (int64_t *)(cookieph + 1);
660 	nowt = lbolt64;
661 	bcopy(&nowt, now, sizeof (*now));
662 
663 	/* cookie lifetime -- need configuration */
664 	lifetime = (uint32_t *)(now + 1);
665 	*lifetime = sctp->sctp_cookie_lifetime;
666 
667 	/* Set the tie-tags */
668 	ttag = (uint32_t *)(lifetime + 1);
669 	if (sctp->sctp_state <= SCTPS_COOKIE_WAIT) {
670 		*ttag = 0;
671 		ttag++;
672 		*ttag = 0;
673 		ttag++;
674 	} else {
675 		/* local tie-tag (network byte-order) */
676 		*ttag = sctp->sctp_lvtag;
677 		ttag++;
678 		/* peer tie-tag (network byte-order) */
679 		*ttag = sctp->sctp_fvtag;
680 		ttag++;
681 	}
682 	/*
683 	 * Copy in peer's original source address so that we can confirm
684 	 * the reachability later.
685 	 */
686 	p = (char *)ttag;
687 	if (isv4) {
688 		in6_addr_t peer_addr;
689 
690 		IN6_IPADDR_TO_V4MAPPED(iackiph->ipha_dst, &peer_addr);
691 		bcopy(&peer_addr, p, sizeof (in6_addr_t));
692 	} else {
693 		bcopy(&iackip6h->ip6_dst, p, sizeof (in6_addr_t));
694 	}
695 	p += sizeof (in6_addr_t);
696 	/* Copy in our INIT ACK chunk */
697 	bcopy(iack, p, sizeof (*iack));
698 	iack = (sctp_init_chunk_t *)p;
699 	/* Set the # of streams we'll end up using */
700 	iack->sic_outstr = MIN(sctp->sctp_num_ostr, ntohs(init->sic_instr));
701 	iack->sic_instr = MIN(sctp->sctp_num_istr, ntohs(init->sic_outstr));
702 	p += sizeof (*iack);
703 
704 	/* Copy in the peer's INIT chunk */
705 	bcopy(ch, p, ntohs(ch->sch_len));
706 	p += ntohs(ch->sch_len);
707 
708 	/*
709 	 * Calculate the HMAC ICV into the digest slot in buf.
710 	 * First, generate a new secret if the current secret is
711 	 * older than the new secret lifetime parameter permits,
712 	 * copying the current secret to sctp_old_secret.
713 	 */
714 	if (sctps->sctps_new_secret_interval > 0 &&
715 	    (sctp->sctp_last_secret_update +
716 	    MSEC_TO_TICK(sctps->sctps_new_secret_interval)) <= nowt) {
717 		bcopy(sctp->sctp_secret, sctp->sctp_old_secret,
718 		    SCTP_SECRET_LEN);
719 		(void) random_get_pseudo_bytes(sctp->sctp_secret,
720 		    SCTP_SECRET_LEN);
721 		sctp->sctp_last_secret_update = nowt;
722 	}
723 
724 	hmac_md5((uchar_t *)now, cookielen - sizeof (*cookieph) - 16,
725 	    (uchar_t *)sctp->sctp_secret, SCTP_SECRET_LEN, (uchar_t *)p);
726 
727 	iackmp->b_wptr = iackmp->b_rptr + ipsctplen;
728 	iackmp->b_cont = errmp;		/*  OK if NULL */
729 
730 	if (is_system_labeled() && (cr = DB_CRED(iackmp)) != NULL &&
731 	    crgetlabel(cr) != NULL) {
732 		conn_t *connp = sctp->sctp_connp;
733 		int err;
734 
735 		if (isv4)
736 			err = tsol_check_label(cr, &iackmp,
737 			    connp->conn_mac_exempt,
738 			    sctps->sctps_netstack->netstack_ip);
739 		else
740 			err = tsol_check_label_v6(cr, &iackmp,
741 			    connp->conn_mac_exempt,
742 			    sctps->sctps_netstack->netstack_ip);
743 		if (err != 0) {
744 			sctp_send_abort(sctp, sctp_init2vtag(ch),
745 			    SCTP_ERR_AUTH_ERR, NULL, 0, initmp, 0, B_FALSE);
746 			freemsg(iackmp);
747 			return;
748 		}
749 	}
750 
751 	/*
752 	 * Stash the conn ptr info. for IP only as e don't have any
753 	 * cached IRE.
754 	 */
755 	SCTP_STASH_IPINFO(iackmp, (ire_t *)NULL);
756 
757 	/* XXX sctp == sctp_g_q, so using its obchunks is valid */
758 	BUMP_LOCAL(sctp->sctp_opkts);
759 	BUMP_LOCAL(sctp->sctp_obchunks);
760 
761 	/* OK to call IP_PUT() here instead of sctp_add_sendq(). */
762 	CONN_INC_REF(sctp->sctp_connp);
763 	iackmp->b_flag |= MSGHASREF;
764 	IP_PUT(iackmp, sctp->sctp_connp, isv4);
765 }
766 
767 void
768 sctp_send_cookie_ack(sctp_t *sctp)
769 {
770 	sctp_chunk_hdr_t *cach;
771 	mblk_t *camp;
772 	sctp_stack_t	*sctps = sctp->sctp_sctps;
773 
774 	camp = sctp_make_mp(sctp, NULL, sizeof (*cach));
775 	if (camp == NULL) {
776 		/* XXX should abort, but don't have the inmp anymore */
777 		SCTP_KSTAT(sctps, sctp_send_cookie_ack_failed);
778 		return;
779 	}
780 
781 	cach = (sctp_chunk_hdr_t *)camp->b_wptr;
782 	camp->b_wptr = (uchar_t *)(cach + 1);
783 	cach->sch_id = CHUNK_COOKIE_ACK;
784 	cach->sch_flags = 0;
785 	cach->sch_len = htons(sizeof (*cach));
786 
787 	sctp_set_iplen(sctp, camp);
788 
789 	BUMP_LOCAL(sctp->sctp_obchunks);
790 
791 	sctp_add_sendq(sctp, camp);
792 }
793 
794 static int
795 sctp_find_al_ind(sctp_parm_hdr_t *sph, ssize_t len, uint32_t *adaptation_code)
796 {
797 
798 	if (len < sizeof (*sph))
799 		return (-1);
800 	while (sph != NULL) {
801 		if (sph->sph_type == htons(PARM_ADAPT_LAYER_IND) &&
802 		    ntohs(sph->sph_len) >= (sizeof (*sph) +
803 		    sizeof (uint32_t))) {
804 			*adaptation_code = *(uint32_t *)(sph + 1);
805 			return (0);
806 		}
807 		sph = sctp_next_parm(sph, &len);
808 	}
809 	return (-1);
810 }
811 
812 void
813 sctp_send_cookie_echo(sctp_t *sctp, sctp_chunk_hdr_t *iackch, mblk_t *iackmp)
814 {
815 	mblk_t			*cemp;
816 	mblk_t			*mp = NULL;
817 	mblk_t			*head;
818 	mblk_t			*meta;
819 	sctp_faddr_t		*fp;
820 	sctp_chunk_hdr_t	*cech;
821 	sctp_init_chunk_t	 *iack;
822 	int32_t			cansend;
823 	int32_t			seglen;
824 	size_t			ceclen;
825 	sctp_parm_hdr_t		*cph;
826 	sctp_data_hdr_t		*sdc;
827 	sctp_tf_t		*tf;
828 	int			pad = 0;
829 	int			hdrlen;
830 	mblk_t			*errmp = NULL;
831 	uint_t			sctp_options;
832 	int			error;
833 	uint16_t		old_num_str;
834 	sctp_stack_t		*sctps = sctp->sctp_sctps;
835 
836 	iack = (sctp_init_chunk_t *)(iackch + 1);
837 
838 	cph = NULL;
839 	if (validate_init_params(sctp, iackch, iack, iackmp, &cph, &errmp,
840 	    &pad, &sctp_options) == 0) { /* result in 'pad' ignored */
841 		BUMP_MIB(&sctps->sctps_mib, sctpAborted);
842 		sctp_assoc_event(sctp, SCTP_CANT_STR_ASSOC, 0, NULL);
843 		sctp_clean_death(sctp, ECONNABORTED);
844 		return;
845 	}
846 	ASSERT(cph != NULL);
847 
848 	ASSERT(sctp->sctp_cookie_mp == NULL);
849 
850 	/* Got a cookie to echo back; allocate an mblk */
851 	ceclen = sizeof (*cech) + ntohs(cph->sph_len) - sizeof (*cph);
852 	if ((pad = ceclen & (SCTP_ALIGN - 1)) != 0)
853 		pad = SCTP_ALIGN - pad;
854 
855 	if (IPH_HDR_VERSION(iackmp->b_rptr) == IPV4_VERSION)
856 		hdrlen = sctp->sctp_hdr_len;
857 	else
858 		hdrlen = sctp->sctp_hdr6_len;
859 
860 	cemp = allocb(sctps->sctps_wroff_xtra + hdrlen + ceclen + pad,
861 	    BPRI_MED);
862 	if (cemp == NULL) {
863 		SCTP_FADDR_TIMER_RESTART(sctp, sctp->sctp_current,
864 		    sctp->sctp_current->rto);
865 		if (errmp != NULL)
866 			freeb(errmp);
867 		return;
868 	}
869 	cemp->b_rptr += (sctps->sctps_wroff_xtra + hdrlen);
870 
871 	/* Process the INIT ACK */
872 	sctp->sctp_sctph->sh_verf = iack->sic_inittag;
873 	sctp->sctp_sctph6->sh_verf = iack->sic_inittag;
874 	sctp->sctp_fvtag = iack->sic_inittag;
875 	sctp->sctp_ftsn = ntohl(iack->sic_inittsn);
876 	sctp->sctp_lastacked = sctp->sctp_ftsn - 1;
877 	sctp->sctp_fcsn = sctp->sctp_lastacked;
878 	sctp->sctp_frwnd = ntohl(iack->sic_a_rwnd);
879 
880 	/*
881 	 * Populate sctp with addresses given in the INIT ACK or IP header.
882 	 * Need to set the df bit in the current fp as it has been cleared
883 	 * in sctp_connect().
884 	 */
885 	sctp->sctp_current->df = B_TRUE;
886 	/*
887 	 * Since IP uses this info during the fanout process, we need to hold
888 	 * the lock for this hash line while performing this operation.
889 	 */
890 	/* XXX sctp_conn_fanout + SCTP_CONN_HASH(sctps, sctp->sctp_ports); */
891 	ASSERT(sctp->sctp_conn_tfp != NULL);
892 	tf = sctp->sctp_conn_tfp;
893 	/* sctp isn't a listener so only need to hold conn fanout lock */
894 	mutex_enter(&tf->tf_lock);
895 	if (sctp_get_addrparams(sctp, NULL, iackmp, iackch, NULL) != 0) {
896 		mutex_exit(&tf->tf_lock);
897 		freeb(cemp);
898 		SCTP_FADDR_TIMER_RESTART(sctp, sctp->sctp_current,
899 		    sctp->sctp_current->rto);
900 		if (errmp != NULL)
901 			freeb(errmp);
902 		return;
903 	}
904 	mutex_exit(&tf->tf_lock);
905 
906 	fp = sctp->sctp_current;
907 
908 	/*
909 	 * There could be a case when we get an INIT-ACK again, if the INIT
910 	 * is re-transmitted, for e.g., which means we would have already
911 	 * allocated this resource earlier (also for sctp_instr). In this
912 	 * case we check and re-allocate, if necessary.
913 	 */
914 	old_num_str = sctp->sctp_num_ostr;
915 	if (ntohs(iack->sic_instr) < sctp->sctp_num_ostr)
916 		sctp->sctp_num_ostr = ntohs(iack->sic_instr);
917 	if (sctp->sctp_ostrcntrs == NULL) {
918 		sctp->sctp_ostrcntrs = kmem_zalloc(sizeof (uint16_t) *
919 		    sctp->sctp_num_ostr, KM_NOSLEEP);
920 	} else {
921 		ASSERT(old_num_str > 0);
922 		if (old_num_str != sctp->sctp_num_ostr) {
923 			kmem_free(sctp->sctp_ostrcntrs, sizeof (uint16_t) *
924 			    old_num_str);
925 			sctp->sctp_ostrcntrs = kmem_zalloc(sizeof (uint16_t) *
926 			    sctp->sctp_num_ostr, KM_NOSLEEP);
927 		}
928 	}
929 	if (sctp->sctp_ostrcntrs == NULL) {
930 		freeb(cemp);
931 		SCTP_FADDR_TIMER_RESTART(sctp, fp, fp->rto);
932 		if (errmp != NULL)
933 			freeb(errmp);
934 		return;
935 	}
936 
937 	/*
938 	 * Allocate the in stream tracking array. Comments for sctp_ostrcntrs
939 	 * hold here too.
940 	 */
941 	old_num_str = sctp->sctp_num_istr;
942 	if (ntohs(iack->sic_outstr) < sctp->sctp_num_istr)
943 		sctp->sctp_num_istr = ntohs(iack->sic_outstr);
944 	if (sctp->sctp_instr == NULL) {
945 		sctp->sctp_instr = kmem_zalloc(sizeof (*sctp->sctp_instr) *
946 		    sctp->sctp_num_istr, KM_NOSLEEP);
947 	} else {
948 		ASSERT(old_num_str > 0);
949 		if (old_num_str != sctp->sctp_num_istr) {
950 			kmem_free(sctp->sctp_instr,
951 			    sizeof (*sctp->sctp_instr) * old_num_str);
952 			sctp->sctp_instr = kmem_zalloc(
953 			    sizeof (*sctp->sctp_instr) * sctp->sctp_num_istr,
954 			    KM_NOSLEEP);
955 		}
956 	}
957 	if (sctp->sctp_instr == NULL) {
958 		kmem_free(sctp->sctp_ostrcntrs,
959 		    sizeof (uint16_t) * sctp->sctp_num_ostr);
960 		freeb(cemp);
961 		SCTP_FADDR_TIMER_RESTART(sctp, fp, fp->rto);
962 		if (errmp != NULL)
963 			freeb(errmp);
964 		return;
965 	}
966 
967 	if (!(sctp_options & SCTP_PRSCTP_OPTION) && sctp->sctp_prsctp_aware)
968 		sctp->sctp_prsctp_aware = B_FALSE;
969 
970 	if (sctp_find_al_ind((sctp_parm_hdr_t *)(iack + 1),
971 	    ntohs(iackch->sch_len) - (sizeof (*iackch) + sizeof (*iack)),
972 	    &sctp->sctp_rx_adaptation_code) == 0) {
973 		sctp->sctp_recv_adaptation = 1;
974 	}
975 
976 	cech = (sctp_chunk_hdr_t *)cemp->b_rptr;
977 	ASSERT(OK_32PTR(cech));
978 	cech->sch_id = CHUNK_COOKIE;
979 	cech->sch_flags = 0;
980 	cech->sch_len = htons(ceclen);
981 
982 	/* Copy the cookie (less the parm hdr) to the chunk */
983 	bcopy(cph + 1, cech + 1, ceclen - sizeof (*cph));
984 
985 	cemp->b_wptr = cemp->b_rptr + ceclen;
986 
987 	if (sctp->sctp_unsent > 0) {
988 		sctp_msg_hdr_t	*smh;
989 		mblk_t		*prev = NULL;
990 		uint32_t	unsent = 0;
991 
992 		mp = sctp->sctp_xmit_unsent;
993 		do {
994 			smh = (sctp_msg_hdr_t *)mp->b_rptr;
995 			if (smh->smh_sid >= sctp->sctp_num_ostr) {
996 				unsent += smh->smh_msglen;
997 				if (prev != NULL)
998 					prev->b_next = mp->b_next;
999 				else
1000 					sctp->sctp_xmit_unsent = mp->b_next;
1001 				mp->b_next = NULL;
1002 				sctp_sendfail_event(sctp, mp, SCTP_ERR_BAD_SID,
1003 				    B_FALSE);
1004 				if (prev != NULL)
1005 					mp = prev->b_next;
1006 				else
1007 					mp = sctp->sctp_xmit_unsent;
1008 			} else {
1009 				prev = mp;
1010 				mp = mp->b_next;
1011 			}
1012 		} while (mp != NULL);
1013 		if (unsent > 0) {
1014 			ASSERT(sctp->sctp_unsent >= unsent);
1015 			sctp->sctp_unsent -= unsent;
1016 			/*
1017 			 * Update ULP the amount of queued data, which is
1018 			 * sent-unack'ed + unsent.
1019 			 * This is not necessary, but doesn't harm, we
1020 			 * just use unsent instead of sent-unack'ed +
1021 			 * unsent, since there won't be any sent-unack'ed
1022 			 * here.
1023 			 */
1024 			if (!SCTP_IS_DETACHED(sctp)) {
1025 				sctp->sctp_ulp_xmitted(sctp->sctp_ulpd,
1026 				    sctp->sctp_unsent);
1027 			}
1028 		}
1029 		if (sctp->sctp_xmit_unsent == NULL)
1030 			sctp->sctp_xmit_unsent_tail = NULL;
1031 	}
1032 	ceclen += pad;
1033 	cansend = MIN(sctp->sctp_unsent, sctp->sctp_frwnd);
1034 	meta = sctp_get_msg_to_send(sctp, &mp, NULL, &error, ceclen,
1035 	    cansend,  NULL);
1036 	/*
1037 	 * The error cannot be anything else since we could have an non-zero
1038 	 * error only if sctp_get_msg_to_send() tries to send a Forward
1039 	 * TSN which will not happen here.
1040 	 */
1041 	ASSERT(error == 0);
1042 	if (meta == NULL)
1043 		goto sendcookie;
1044 	sctp->sctp_xmit_tail = meta;
1045 	sdc = (sctp_data_hdr_t *)mp->b_rptr;
1046 	seglen = ntohs(sdc->sdh_len);
1047 	if ((ceclen + seglen) > fp->sfa_pmss ||
1048 	    (seglen - sizeof (*sdc)) > cansend) {
1049 		goto sendcookie;
1050 	}
1051 	/* OK, if this fails */
1052 	cemp->b_cont = dupmsg(mp);
1053 sendcookie:
1054 	head = sctp_add_proto_hdr(sctp, fp, cemp, 0, NULL);
1055 	if (head == NULL) {
1056 		freemsg(cemp);
1057 		SCTP_FADDR_TIMER_RESTART(sctp, fp, fp->rto);
1058 		if (errmp != NULL)
1059 			freeb(errmp);
1060 		SCTP_KSTAT(sctps, sctp_send_cookie_failed);
1061 		return;
1062 	}
1063 	/*
1064 	 * Even if cookie-echo exceeds MTU for one of the hops, it'll
1065 	 * have a chance of getting there.
1066 	 */
1067 	if (fp->isv4) {
1068 		ipha_t *iph = (ipha_t *)head->b_rptr;
1069 		iph->ipha_fragment_offset_and_flags = 0;
1070 	}
1071 	BUMP_LOCAL(sctp->sctp_obchunks);
1072 
1073 	sctp->sctp_cookie_mp = dupmsg(head);
1074 	/* Don't bundle, we will just resend init if this cookie is lost. */
1075 	if (sctp->sctp_cookie_mp == NULL) {
1076 		if (cemp->b_cont != NULL) {
1077 			freemsg(cemp->b_cont);
1078 			cemp->b_cont = NULL;
1079 		}
1080 	} else if (cemp->b_cont != NULL) {
1081 		ASSERT(mp != NULL && mp == meta->b_cont);
1082 		SCTP_CHUNK_CLEAR_FLAGS(cemp->b_cont);
1083 		cemp->b_wptr += pad;
1084 		seglen -= sizeof (*sdc);
1085 		SCTP_CHUNK_SENT(sctp, mp, sdc, fp, seglen, meta);
1086 	}
1087 	if (errmp != NULL)
1088 		linkb(head, errmp);
1089 	sctp->sctp_state = SCTPS_COOKIE_ECHOED;
1090 	SCTP_FADDR_TIMER_RESTART(sctp, fp, fp->rto);
1091 
1092 	sctp_set_iplen(sctp, head);
1093 	sctp_add_sendq(sctp, head);
1094 }
1095 
1096 int
1097 sctp_process_cookie(sctp_t *sctp, sctp_chunk_hdr_t *ch, mblk_t *cmp,
1098     sctp_init_chunk_t **iackpp, sctp_hdr_t *insctph, int *recv_adaptation,
1099     in6_addr_t *peer_addr)
1100 {
1101 	int32_t			clen;
1102 	size_t			initplen;
1103 	uchar_t			*p;
1104 	uchar_t			*given_hash;
1105 	uchar_t			needed_hash[16];
1106 	int64_t			ts;
1107 	int64_t			diff;
1108 	uint32_t		*lt;
1109 	sctp_init_chunk_t	*iack;
1110 	sctp_chunk_hdr_t	*initch;
1111 	sctp_init_chunk_t	*init;
1112 	uint32_t		*lttag;
1113 	uint32_t		*fttag;
1114 	uint32_t		ports;
1115 	sctp_stack_t		*sctps = sctp->sctp_sctps;
1116 
1117 	BUMP_LOCAL(sctp->sctp_ibchunks);
1118 	/* Verify the ICV */
1119 	clen = ntohs(ch->sch_len) - sizeof (*ch) - 16;
1120 	if (clen < 0) {
1121 		dprint(1, ("invalid cookie chunk length %d\n",
1122 		    ntohs(ch->sch_len)));
1123 
1124 		return (-1);
1125 	}
1126 	p = (uchar_t *)(ch + 1);
1127 
1128 	hmac_md5(p, clen, (uchar_t *)sctp->sctp_secret, SCTP_SECRET_LEN,
1129 	    needed_hash);
1130 
1131 	/* The given hash follows the cookie data */
1132 	given_hash = p + clen;
1133 
1134 	if (bcmp(given_hash, needed_hash, 16) != 0) {
1135 		/* The secret may have changed; try the old secret */
1136 		hmac_md5(p, clen, (uchar_t *)sctp->sctp_old_secret,
1137 		    SCTP_SECRET_LEN, needed_hash);
1138 		if (bcmp(given_hash, needed_hash, 16) != 0) {
1139 			return (-1);
1140 		}
1141 	}
1142 
1143 	/* Timestamp is int64_t, and we only guarantee 32-bit alignment */
1144 	bcopy(p, &ts, sizeof (ts));
1145 	/* Cookie life time, uint32_t */
1146 	lt = (uint32_t *)(p + sizeof (ts));
1147 
1148 	/*
1149 	 * To quote PRC, "this is our baby", so let's continue.
1150 	 * We need to pull out the encapsulated INIT ACK and
1151 	 * INIT chunks. Note that we don't process these until
1152 	 * we have verified the timestamp, but we need them before
1153 	 * processing the timestamp since if the time check fails,
1154 	 * we need to get the verification tag from the INIT in order
1155 	 * to send a stale cookie error.
1156 	 */
1157 	lttag = (uint32_t *)(lt + 1);
1158 	fttag = lttag + 1;
1159 	if (peer_addr != NULL)
1160 		bcopy(fttag + 1, peer_addr, sizeof (in6_addr_t));
1161 	iack = (sctp_init_chunk_t *)((char *)(fttag + 1) + sizeof (in6_addr_t));
1162 	initch = (sctp_chunk_hdr_t *)(iack + 1);
1163 	init = (sctp_init_chunk_t *)(initch + 1);
1164 	initplen = ntohs(initch->sch_len) - (sizeof (*init) + sizeof (*initch));
1165 	*iackpp = iack;
1166 	*recv_adaptation = 0;
1167 
1168 	/*
1169 	 * Check the staleness of the Cookie, specified in 3.3.10.3 of
1170 	 * RFC 2960.
1171 	 *
1172 	 * The mesaure of staleness is the difference, in microseconds,
1173 	 * between the current time and the time the State Cookie expires.
1174 	 * So it is lbolt64 - (ts + *lt).  If it is positive, it means
1175 	 * that the Cookie has expired.
1176 	 */
1177 	diff = lbolt64 - (ts + *lt);
1178 	if (diff > 0 && (init->sic_inittag != sctp->sctp_fvtag ||
1179 	    iack->sic_inittag != sctp->sctp_lvtag)) {
1180 		uint32_t staleness;
1181 
1182 		staleness = TICK_TO_USEC(diff);
1183 		staleness = htonl(staleness);
1184 		sctp_send_abort(sctp, init->sic_inittag, SCTP_ERR_STALE_COOKIE,
1185 		    (char *)&staleness, sizeof (staleness), cmp, 1, B_FALSE);
1186 
1187 		dprint(1, ("stale cookie %d\n", staleness));
1188 
1189 		return (-1);
1190 	}
1191 
1192 	/* Check for attack by adding addresses to a restart */
1193 	bcopy(insctph, &ports, sizeof (ports));
1194 	if (sctp_secure_restart_check(cmp, initch, ports, KM_NOSLEEP,
1195 	    sctps) != 1) {
1196 		return (-1);
1197 	}
1198 
1199 	/* Look for adaptation code if there any parms in the INIT chunk */
1200 	if ((initplen >= sizeof (sctp_parm_hdr_t)) &&
1201 	    (sctp_find_al_ind((sctp_parm_hdr_t *)(init + 1), initplen,
1202 	    &sctp->sctp_rx_adaptation_code) == 0)) {
1203 		*recv_adaptation = 1;
1204 	}
1205 
1206 	/* Examine tie-tags */
1207 
1208 	if (sctp->sctp_state >= SCTPS_COOKIE_WAIT) {
1209 		if (sctp->sctp_state == SCTPS_ESTABLISHED &&
1210 		    init->sic_inittag == sctp->sctp_fvtag &&
1211 		    iack->sic_inittag == sctp->sctp_lvtag &&
1212 		    *fttag == 0 && *lttag == 0) {
1213 
1214 			dprint(1, ("duplicate cookie from %x:%x:%x:%x (%d)\n",
1215 			    SCTP_PRINTADDR(sctp->sctp_current->faddr),
1216 			    (int)(sctp->sctp_fport)));
1217 			return (-1);
1218 		}
1219 
1220 		if (init->sic_inittag != sctp->sctp_fvtag &&
1221 		    iack->sic_inittag != sctp->sctp_lvtag &&
1222 		    *fttag == sctp->sctp_fvtag &&
1223 		    *lttag == sctp->sctp_lvtag) {
1224 			int i;
1225 
1226 			/* Section 5.2.4 case A: restart */
1227 			sctp->sctp_fvtag = init->sic_inittag;
1228 			sctp->sctp_lvtag = iack->sic_inittag;
1229 
1230 			sctp->sctp_sctph->sh_verf = init->sic_inittag;
1231 			sctp->sctp_sctph6->sh_verf = init->sic_inittag;
1232 
1233 			sctp->sctp_ftsn = ntohl(init->sic_inittsn);
1234 			sctp->sctp_lastacked = sctp->sctp_ftsn - 1;
1235 			sctp->sctp_frwnd = ntohl(init->sic_a_rwnd);
1236 			sctp->sctp_fcsn = sctp->sctp_lastacked;
1237 
1238 			if (sctp->sctp_state < SCTPS_ESTABLISHED) {
1239 				sctp->sctp_state = SCTPS_ESTABLISHED;
1240 				sctp->sctp_assoc_start_time = (uint32_t)lbolt;
1241 			}
1242 
1243 			dprint(1, ("sctp peer %x:%x:%x:%x (%d) restarted\n",
1244 			    SCTP_PRINTADDR(sctp->sctp_current->faddr),
1245 			    (int)(sctp->sctp_fport)));
1246 			/* reset parameters */
1247 			sctp_congest_reset(sctp);
1248 
1249 			/* reset stream bookkeeping */
1250 			sctp_instream_cleanup(sctp, B_FALSE);
1251 
1252 			sctp->sctp_istr_nmsgs = 0;
1253 			sctp->sctp_rxqueued = 0;
1254 			for (i = 0; i < sctp->sctp_num_ostr; i++) {
1255 				sctp->sctp_ostrcntrs[i] = 0;
1256 			}
1257 			/* XXX flush xmit_list? */
1258 
1259 			return (0);
1260 		} else if (init->sic_inittag != sctp->sctp_fvtag &&
1261 		    iack->sic_inittag == sctp->sctp_lvtag) {
1262 
1263 			/* Section 5.2.4 case B: INIT collision */
1264 			if (sctp->sctp_state < SCTPS_ESTABLISHED) {
1265 				if (!sctp_initialize_params(sctp, init, iack))
1266 					return (-1);	/* Drop? */
1267 				sctp->sctp_state = SCTPS_ESTABLISHED;
1268 				sctp->sctp_assoc_start_time = (uint32_t)lbolt;
1269 			}
1270 
1271 			dprint(1, ("init collision with %x:%x:%x:%x (%d)\n",
1272 			    SCTP_PRINTADDR(sctp->sctp_current->faddr),
1273 			    (int)(sctp->sctp_fport)));
1274 
1275 			return (0);
1276 		} else if (iack->sic_inittag != sctp->sctp_lvtag &&
1277 		    init->sic_inittag == sctp->sctp_fvtag &&
1278 		    *fttag == 0 && *lttag == 0) {
1279 
1280 			/* Section 5.2.4 case C: late COOKIE */
1281 			dprint(1, ("late cookie from %x:%x:%x:%x (%d)\n",
1282 			    SCTP_PRINTADDR(sctp->sctp_current->faddr),
1283 			    (int)(sctp->sctp_fport)));
1284 			return (-1);
1285 		} else if (init->sic_inittag == sctp->sctp_fvtag &&
1286 		    iack->sic_inittag == sctp->sctp_lvtag) {
1287 
1288 			/*
1289 			 * Section 5.2.4 case D: COOKIE ECHO retransmit
1290 			 * Don't check cookie lifetime
1291 			 */
1292 			dprint(1, ("cookie tags match from %x:%x:%x:%x (%d)\n",
1293 			    SCTP_PRINTADDR(sctp->sctp_current->faddr),
1294 			    (int)(sctp->sctp_fport)));
1295 			if (sctp->sctp_state < SCTPS_ESTABLISHED) {
1296 				if (!sctp_initialize_params(sctp, init, iack))
1297 					return (-1);	/* Drop? */
1298 				sctp->sctp_state = SCTPS_ESTABLISHED;
1299 				sctp->sctp_assoc_start_time = (uint32_t)lbolt;
1300 			}
1301 			return (0);
1302 		} else {
1303 			/* unrecognized case -- silently drop it */
1304 			return (-1);
1305 		}
1306 	}
1307 
1308 	return (0);
1309 }
1310 
1311 /*
1312  * Similar to ip_fanout_sctp, except that the src addr(s) are drawn
1313  * from address parameters in an INIT ACK's address list. This
1314  * function is used when an INIT ACK is received but IP's fanout
1315  * function could not find a sctp via the normal lookup routine.
1316  * This can happen when a host sends an INIT ACK from a different
1317  * address than the INIT was sent to.
1318  *
1319  * Returns the sctp_t if found, or NULL if not found.
1320  */
1321 sctp_t *
1322 sctp_addrlist2sctp(mblk_t *mp, sctp_hdr_t *sctph, sctp_chunk_hdr_t *ich,
1323     zoneid_t zoneid, sctp_stack_t *sctps)
1324 {
1325 	int isv4;
1326 	ipha_t *iph;
1327 	ip6_t *ip6h;
1328 	in6_addr_t dst;
1329 	in6_addr_t src;
1330 	sctp_parm_hdr_t *ph;
1331 	ssize_t remaining;
1332 	sctp_init_chunk_t *iack;
1333 	uint32_t ports;
1334 	sctp_t *sctp = NULL;
1335 
1336 	ASSERT(ich->sch_id == CHUNK_INIT_ACK);
1337 
1338 	isv4 = (IPH_HDR_VERSION(mp->b_rptr) == IPV4_VERSION);
1339 	if (isv4) {
1340 		iph = (ipha_t *)mp->b_rptr;
1341 		IN6_IPADDR_TO_V4MAPPED(iph->ipha_dst, &dst);
1342 	} else {
1343 		ip6h = (ip6_t *)mp->b_rptr;
1344 		dst = ip6h->ip6_dst;
1345 	}
1346 
1347 	ports = *(uint32_t *)sctph;
1348 
1349 	dprint(1, ("sctp_addrlist2sctp: ports=%u, dst = %x:%x:%x:%x\n",
1350 	    ports, SCTP_PRINTADDR(dst)));
1351 
1352 	/* pull out any address parameters */
1353 	remaining = ntohs(ich->sch_len) - sizeof (*ich) - sizeof (*iack);
1354 	if (remaining < sizeof (*ph)) {
1355 		return (NULL);
1356 	}
1357 
1358 	iack = (sctp_init_chunk_t *)(ich + 1);
1359 	ph = (sctp_parm_hdr_t *)(iack + 1);
1360 
1361 	while (ph != NULL) {
1362 		/*
1363 		 * params have been put in host byteorder by
1364 		 * sctp_check_input()
1365 		 */
1366 		if (ph->sph_type == PARM_ADDR4) {
1367 			IN6_INADDR_TO_V4MAPPED((struct in_addr *)(ph + 1),
1368 			    &src);
1369 
1370 			sctp = sctp_conn_match(&src, &dst, ports, zoneid,
1371 			    sctps);
1372 
1373 			dprint(1,
1374 			    ("sctp_addrlist2sctp: src=%x:%x:%x:%x, sctp=%p\n",
1375 			    SCTP_PRINTADDR(src), (void *)sctp));
1376 
1377 
1378 			if (sctp != NULL) {
1379 				return (sctp);
1380 			}
1381 		} else if (ph->sph_type == PARM_ADDR6) {
1382 			src = *(in6_addr_t *)(ph + 1);
1383 			sctp = sctp_conn_match(&src, &dst, ports, zoneid,
1384 			    sctps);
1385 
1386 			dprint(1,
1387 			    ("sctp_addrlist2sctp: src=%x:%x:%x:%x, sctp=%p\n",
1388 			    SCTP_PRINTADDR(src), (void *)sctp));
1389 
1390 			if (sctp != NULL) {
1391 				return (sctp);
1392 			}
1393 		}
1394 
1395 		ph = sctp_next_parm(ph, &remaining);
1396 	}
1397 
1398 	return (NULL);
1399 }
1400