xref: /titanic_41/usr/src/uts/common/inet/sctp/sctp_cookie.c (revision 4e5b757fbcf21077677360be274461dcd9064106)
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 2007 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,
160 		    ("validate_init_params: bad sid, is=%d os=%d\n",
161 			htons(init->sic_instr), htons(init->sic_outstr)));
162 		goto abort;
163 	}
164 	if (ntohl(init->sic_inittag) == 0) {
165 		serror = SCTP_ERR_BAD_MANDPARM;
166 		dprint(1, ("validate_init_params: inittag = 0\n"));
167 		goto abort;
168 	}
169 
170 	remaining = ntohs(ch->sch_len) - sizeof (*ch);
171 	ic = (sctp_init_chunk_t *)(ch + 1);
172 	remaining -= sizeof (*ic);
173 	if (remaining < sizeof (*cph)) {
174 		/* Nothing to validate */
175 		if (want_cookie != NULL)
176 			goto cookie_abort;
177 		return (1);
178 	}
179 
180 	cph = (sctp_parm_hdr_t *)(ic + 1);
181 
182 	while (cph != NULL) {
183 		ptype = ntohs(cph->sph_type);
184 		switch (ptype) {
185 		case PARM_HBINFO:
186 		case PARM_UNRECOGNIZED:
187 		case PARM_ECN:
188 			/* just ignore them */
189 			break;
190 		case PARM_FORWARD_TSN:
191 			if (sctp_options != NULL)
192 				*sctp_options |= SCTP_PRSCTP_OPTION;
193 			break;
194 		case PARM_COOKIE:
195 			got_cookie = B_TRUE;
196 			if (want_cookie != NULL) {
197 				*want_cookie = cph;
198 			}
199 			break;
200 		case PARM_ADDR4:
201 			*supp_af |= PARM_SUPP_V4;
202 			break;
203 		case PARM_ADDR6:
204 			*supp_af |= PARM_SUPP_V6;
205 			break;
206 		case PARM_COOKIE_PRESERVE:
207 		case PARM_ADAPT_LAYER_IND:
208 			/* These are OK */
209 			break;
210 		case PARM_ADDR_HOST_NAME:
211 			/* Don't support this; abort the association */
212 			serror = SCTP_ERR_BAD_ADDR;
213 			details = (char *)cph;
214 			errlen = ntohs(cph->sph_len);
215 			dprint(1, ("sctp:validate_init_params: host addr\n"));
216 			goto abort;
217 		case PARM_SUPP_ADDRS: {
218 			/* Make sure we have a supported addr intersection */
219 			uint16_t *p, addrtype;
220 			int plen;
221 
222 			plen = ntohs(cph->sph_len);
223 			p = (uint16_t *)(cph + 1);
224 			while (plen > 0) {
225 				addrtype = ntohs(*p);
226 				switch (addrtype) {
227 				case PARM_ADDR6:
228 					*supp_af |= PARM_SUPP_V6;
229 					break;
230 				case PARM_ADDR4:
231 					*supp_af |= PARM_SUPP_V4;
232 					break;
233 				default:
234 					/*
235 					 * Do nothing, silently ignore hostname
236 					 * address.
237 					 */
238 					break;
239 				}
240 				p++;
241 				plen -= sizeof (*p);
242 			}
243 			break;
244 		}
245 		default:
246 			/* Unrecognized param; check the high order bits */
247 			if ((ptype & 0xc000) == 0xc000) {
248 				/*
249 				 * report unrecognized param, and
250 				 * keep processing
251 				 */
252 				if (errmp != NULL) {
253 					if (want_cookie != NULL) {
254 						*errmp = sctp_make_err(sctp,
255 						    PARM_UNRECOGNIZED,
256 						    (void *)cph,
257 						    ntohs(cph->sph_len));
258 					} else {
259 						sctp_add_unrec_parm(cph, errmp);
260 					}
261 				}
262 				break;
263 			}
264 			if (ptype & 0x4000) {
265 				/*
266 				 * Stop processing and drop; report
267 				 * unrecognized param
268 				 */
269 				serror = SCTP_ERR_UNREC_PARM;
270 				details = (char *)cph;
271 				errlen = ntohs(cph->sph_len);
272 				goto abort;
273 			}
274 			if (ptype & 0x8000) {
275 				/* skip and continue processing */
276 				break;
277 			}
278 
279 			/*
280 			 * 2 high bits are clear; stop processing and
281 			 * drop packet
282 			 */
283 			return (0);
284 		}
285 
286 		cph = sctp_next_parm(cph, &remaining);
287 	}
288 	/*
289 	 * Some sanity checks.  The following should not fail unless the
290 	 * other side is broken.
291 	 *
292 	 * 1. If this is a V4 endpoint but V4 address is not
293 	 * supported, abort.
294 	 * 2. If this is a V6 only endpoint but V6 address is
295 	 * not supported, abort.  This assumes that a V6
296 	 * endpoint can use both V4 and V6 addresses.
297 	 * We only care about supp_af when processing INIT, i.e want_cookie
298 	 * is NULL.
299 	 */
300 	if (want_cookie == NULL &&
301 	    ((sctp->sctp_family == AF_INET && !(*supp_af & PARM_SUPP_V4)) ||
302 	    (sctp->sctp_family == AF_INET6 && !(*supp_af & PARM_SUPP_V6) &&
303 	    sctp->sctp_connp->conn_ipv6_v6only))) {
304 		dprint(1, ("sctp:validate_init_params: supp addr\n"));
305 		serror = SCTP_ERR_BAD_ADDR;
306 		goto abort;
307 	}
308 
309 	if (want_cookie != NULL && !got_cookie) {
310 cookie_abort:
311 		dprint(1, ("validate_init_params: cookie absent\n"));
312 		sctp_send_abort(sctp, sctp_init2vtag(ch), SCTP_ERR_MISSING_PARM,
313 		    details, errlen, inmp, 0, B_FALSE);
314 		return (0);
315 	}
316 
317 	/* OK */
318 	return (1);
319 
320 abort:
321 	if (want_cookie != NULL)
322 		return (0);
323 
324 	sctp_send_abort(sctp, sctp_init2vtag(ch), serror, details,
325 	    errlen, inmp, 0, B_FALSE);
326 	return (0);
327 }
328 
329 /*
330  * Initialize params from the INIT and INIT-ACK when the assoc. is
331  * established.
332  */
333 boolean_t
334 sctp_initialize_params(sctp_t *sctp, sctp_init_chunk_t *init,
335     sctp_init_chunk_t *iack)
336 {
337 	/* Get initial TSN */
338 	sctp->sctp_ftsn = ntohl(init->sic_inittsn);
339 	sctp->sctp_lastacked = sctp->sctp_ftsn - 1;
340 
341 	/* Serial number is initialized to the same value as the TSN */
342 	sctp->sctp_fcsn = sctp->sctp_lastacked;
343 
344 	/*
345 	 * Get verification tags; no byteordering is necessary, since
346 	 * verfication tags are never processed except for byte-by-byte
347 	 * comparisons.
348 	 */
349 	sctp->sctp_fvtag = init->sic_inittag;
350 	sctp->sctp_sctph->sh_verf = init->sic_inittag;
351 	sctp->sctp_sctph6->sh_verf = init->sic_inittag;
352 	sctp->sctp_lvtag = iack->sic_inittag;
353 
354 	/* Get the peer's rwnd */
355 	sctp->sctp_frwnd = ntohl(init->sic_a_rwnd);
356 
357 	/* Allocate the in/out-stream counters */
358 	sctp->sctp_num_ostr = iack->sic_outstr;
359 	sctp->sctp_ostrcntrs = kmem_zalloc(sizeof (uint16_t) *
360 	    sctp->sctp_num_ostr, KM_NOSLEEP);
361 	if (sctp->sctp_ostrcntrs == NULL)
362 		return (B_FALSE);
363 
364 	sctp->sctp_num_istr = iack->sic_instr;
365 	sctp->sctp_instr = kmem_zalloc(sizeof (*sctp->sctp_instr) *
366 	    sctp->sctp_num_istr, KM_NOSLEEP);
367 	if (sctp->sctp_instr == NULL) {
368 		kmem_free(sctp->sctp_ostrcntrs, sizeof (uint16_t) *
369 		    sctp->sctp_num_ostr);
370 		sctp->sctp_ostrcntrs = NULL;
371 		return (B_FALSE);
372 	}
373 	return (B_TRUE);
374 }
375 
376 /*
377  * Copy the peer's original source address into addr. This relies on the
378  * following format (see sctp_send_initack() below):
379  * 	relative timestamp for the cookie (int64_t) +
380  * 	cookie lifetime (uint32_t) +
381  * 	local tie-tag (uint32_t) +  peer tie-tag (uint32_t) +
382  * 	Peer's original src ...
383  */
384 int
385 cl_sctp_cookie_paddr(sctp_chunk_hdr_t *ch, in6_addr_t *addr)
386 {
387 	uchar_t	*off;
388 
389 	ASSERT(addr != NULL);
390 
391 	if (ch->sch_id != CHUNK_COOKIE)
392 		return (EINVAL);
393 
394 	off = (uchar_t *)ch + sizeof (*ch) + sizeof (int64_t) +
395 	    sizeof (uint32_t) + sizeof (uint32_t) + sizeof (uint32_t);
396 
397 	bcopy(off, addr, sizeof (*addr));
398 
399 	return (0);
400 }
401 
402 #define	SCTP_CALC_COOKIE_LEN(initcp) \
403 	sizeof (int64_t) +		/* timestamp */			\
404 	sizeof (uint32_t) +		/* cookie lifetime */		\
405 	sizeof (sctp_init_chunk_t) +	/* INIT ACK */			\
406 	sizeof (in6_addr_t) +		/* peer's original source */ 	\
407 	ntohs((initcp)->sch_len) +	/* peer's INIT */		\
408 	sizeof (uint32_t) +		/* local tie-tag */		\
409 	sizeof (uint32_t) +		/* peer tie-tag */		\
410 	sizeof (sctp_parm_hdr_t) +	/* param header */		\
411 	16				/* MD5 hash */
412 
413 void
414 sctp_send_initack(sctp_t *sctp, sctp_hdr_t *initsh, sctp_chunk_hdr_t *ch,
415     mblk_t *initmp)
416 {
417 	ipha_t			*initiph;
418 	ip6_t			*initip6h;
419 	ipha_t			*iackiph;
420 	ip6_t			*iackip6h;
421 	sctp_chunk_hdr_t	*iack_ch;
422 	sctp_init_chunk_t	*iack;
423 	sctp_init_chunk_t	*init;
424 	sctp_hdr_t		*iacksh;
425 	size_t			cookielen;
426 	size_t			iacklen;
427 	size_t			ipsctplen;
428 	size_t			errlen = 0;
429 	sctp_parm_hdr_t		*cookieph;
430 	mblk_t			*iackmp;
431 	uint32_t		itag;
432 	uint32_t		itsn;
433 	int64_t			*now;
434 	int64_t			nowt;
435 	uint32_t		*lifetime;
436 	char			*p;
437 	boolean_t		 isv4;
438 	int			supp_af = 0;
439 	uint_t			sctp_options;
440 	uint32_t		*ttag;
441 	int			pad;
442 	mblk_t			*errmp = NULL;
443 	boolean_t		initcollision = B_FALSE;
444 	boolean_t		linklocal = B_FALSE;
445 	cred_t			*cr;
446 	ts_label_t		*initlabel;
447 	sctp_stack_t		*sctps = sctp->sctp_sctps;
448 
449 	BUMP_LOCAL(sctp->sctp_ibchunks);
450 	isv4 = (IPH_HDR_VERSION(initmp->b_rptr) == IPV4_VERSION);
451 
452 	/* Extract the INIT chunk */
453 	if (isv4) {
454 		initiph = (ipha_t *)initmp->b_rptr;
455 		ipsctplen = sctp->sctp_ip_hdr_len;
456 		supp_af |= PARM_SUPP_V4;
457 	} else {
458 		initip6h = (ip6_t *)initmp->b_rptr;
459 		ipsctplen = sctp->sctp_ip_hdr6_len;
460 		if (IN6_IS_ADDR_LINKLOCAL(&initip6h->ip6_src))
461 			linklocal = B_TRUE;
462 		supp_af |= PARM_SUPP_V6;
463 	}
464 	ASSERT(OK_32PTR(initsh));
465 	init = (sctp_init_chunk_t *)((char *)(initsh + 1) + sizeof (*iack_ch));
466 
467 	/* Make sure we like the peer's parameters */
468 	if (validate_init_params(sctp, ch, init, initmp, NULL, &errmp,
469 		&supp_af, &sctp_options) == 0) {
470 		return;
471 	}
472 	if (errmp != NULL)
473 		errlen = msgdsize(errmp);
474 	if (sctp->sctp_family == AF_INET) {
475 		/*
476 		 * Irregardless of the supported address in the INIT, v4
477 		 * must be supported.
478 		 */
479 		supp_af = PARM_SUPP_V4;
480 	}
481 	if (sctp->sctp_state <= SCTPS_LISTEN) {
482 		/* normal, expected INIT: generate new vtag and itsn */
483 		(void) random_get_pseudo_bytes((uint8_t *)&itag, sizeof (itag));
484 		if (itag == 0)
485 			itag = (uint32_t)gethrtime();
486 		itsn = itag + 1;
487 		itag = htonl(itag);
488 	} else if (sctp->sctp_state == SCTPS_COOKIE_WAIT ||
489 	    sctp->sctp_state == SCTPS_COOKIE_ECHOED) {
490 		/* init collision; copy vtag and itsn from sctp */
491 		itag = sctp->sctp_lvtag;
492 		itsn = sctp->sctp_ltsn;
493 		/*
494 		 * In addition we need to send all the params that was sent
495 		 * in our INIT chunk. Essentially, it is only the supported
496 		 * address params that we need to add.
497 		 */
498 		initcollision = B_TRUE;
499 		/*
500 		 * When we sent the INIT, we should have set linklocal in
501 		 * the sctp which should be good enough.
502 		 */
503 		if (linklocal)
504 			linklocal = B_FALSE;
505 	} else {
506 		/* peer restart; generate new vtag but keep everything else */
507 		(void) random_get_pseudo_bytes((uint8_t *)&itag, sizeof (itag));
508 		if (itag == 0)
509 			itag = (uint32_t)gethrtime();
510 		itag = htonl(itag);
511 		itsn = sctp->sctp_ltsn;
512 	}
513 
514 	/*
515 	 * Allocate a mblk for the INIT ACK, consisting of the link layer
516 	 * header, the IP header, the SCTP common header, and INIT ACK chunk,
517 	 * and finally the COOKIE parameter.
518 	 */
519 	cookielen = SCTP_CALC_COOKIE_LEN(ch);
520 	iacklen = sizeof (*iack_ch) + sizeof (*iack) + cookielen;
521 	if (sctp->sctp_send_adaption)
522 		iacklen += (sizeof (sctp_parm_hdr_t) + sizeof (uint32_t));
523 	if (((sctp_options & SCTP_PRSCTP_OPTION) || initcollision) &&
524 	    sctp->sctp_prsctp_aware && sctps->sctps_prsctp_enabled) {
525 		iacklen += sctp_options_param_len(sctp, SCTP_PRSCTP_OPTION);
526 	}
527 	if (initcollision)
528 		iacklen += sctp_supaddr_param_len(sctp);
529 	if (!linklocal)
530 		iacklen += sctp_addr_params(sctp, supp_af, NULL, B_FALSE);
531 	ipsctplen += sizeof (*iacksh) + iacklen;
532 	iacklen += errlen;
533 	if ((pad = ipsctplen % 4) != 0) {
534 		pad = 4 - pad;
535 		ipsctplen += pad;
536 	}
537 
538 	/*
539 	 * If the listen socket is bound to a trusted extensions
540 	 * multi-label port, attach a copy of the listener's cred
541 	 * to the new INITACK mblk. Modify the cred to contain
542 	 * the security label of the received INIT packet.
543 	 * If not a multi-label port, attach the unmodified
544 	 * listener's cred directly.
545 	 *
546 	 * We expect Sun developed kernel modules to properly set
547 	 * cred labels for sctp connections. We can't be so sure this
548 	 * will be done correctly when 3rd party kernel modules
549 	 * directly use sctp. The initlabel panic guard logic was
550 	 * added to cover this possibility.
551 	 */
552 	if (sctp->sctp_connp->conn_mlp_type != mlptSingle) {
553 		initlabel = MBLK_GETLABEL(initmp);
554 		if (initlabel == NULL) {
555 			sctp_send_abort(sctp, sctp_init2vtag(ch),
556 			    SCTP_ERR_UNKNOWN, NULL, 0, initmp, 0, B_FALSE);
557 			return;
558 		}
559 		cr = copycred_from_bslabel(CONN_CRED(sctp->sctp_connp),
560 		    &initlabel->tsl_label, initlabel->tsl_doi, KM_NOSLEEP);
561 		if (cr == NULL) {
562 			sctp_send_abort(sctp, sctp_init2vtag(ch),
563 			    SCTP_ERR_NO_RESOURCES, NULL, 0, initmp, 0, B_FALSE);
564 			return;
565 		}
566 		iackmp = allocb_cred(ipsctplen + sctps->sctps_wroff_xtra, cr);
567 		crfree(cr);
568 	} else {
569 		iackmp = allocb_cred(ipsctplen + sctps->sctps_wroff_xtra,
570 		    CONN_CRED(sctp->sctp_connp));
571 	}
572 	if (iackmp == NULL) {
573 		sctp_send_abort(sctp, sctp_init2vtag(ch),
574 		    SCTP_ERR_NO_RESOURCES, NULL, 0, initmp, 0, B_FALSE);
575 		return;
576 	}
577 
578 	/* Copy in the [imcomplete] IP/SCTP composite header */
579 	p = (char *)(iackmp->b_rptr + sctps->sctps_wroff_xtra);
580 	iackmp->b_rptr = (uchar_t *)p;
581 	if (isv4) {
582 		bcopy(sctp->sctp_iphc, p, sctp->sctp_hdr_len);
583 		iackiph = (ipha_t *)p;
584 
585 		/* Copy the peer's IP addr */
586 		iackiph->ipha_dst = initiph->ipha_src;
587 		iackiph->ipha_src = initiph->ipha_dst;
588 		iackiph->ipha_length = htons(ipsctplen + errlen);
589 		iacksh = (sctp_hdr_t *)(p + sctp->sctp_ip_hdr_len);
590 	} else {
591 		bcopy(sctp->sctp_iphc6, p, sctp->sctp_hdr6_len);
592 		iackip6h = (ip6_t *)p;
593 
594 		/* Copy the peer's IP addr */
595 		iackip6h->ip6_dst = initip6h->ip6_src;
596 		iackip6h->ip6_src = initip6h->ip6_dst;
597 		iackip6h->ip6_plen = htons(ipsctplen - sizeof (*iackip6h) +
598 		    errlen);
599 		iacksh = (sctp_hdr_t *)(p + sctp->sctp_ip_hdr6_len);
600 	}
601 	ASSERT(OK_32PTR(iacksh));
602 
603 	/* Fill in the holes in the SCTP common header */
604 	iacksh->sh_sport = initsh->sh_dport;
605 	iacksh->sh_dport = initsh->sh_sport;
606 	iacksh->sh_verf = init->sic_inittag;
607 
608 	/* INIT ACK chunk header */
609 	iack_ch = (sctp_chunk_hdr_t *)(iacksh + 1);
610 	iack_ch->sch_id = CHUNK_INIT_ACK;
611 	iack_ch->sch_flags = 0;
612 	iack_ch->sch_len = htons(iacklen);
613 
614 	/* The INIT ACK itself */
615 	iack = (sctp_init_chunk_t *)(iack_ch + 1);
616 	iack->sic_inittag = itag;	/* already in network byteorder */
617 	iack->sic_inittsn = htonl(itsn);
618 
619 	iack->sic_a_rwnd = htonl(sctp->sctp_rwnd);
620 	/* Advertise what we would want to have as stream #'s */
621 	iack->sic_outstr = htons(MIN(sctp->sctp_num_ostr,
622 	    ntohs(init->sic_instr)));
623 	iack->sic_instr = htons(sctp->sctp_num_istr);
624 
625 	p = (char *)(iack + 1);
626 	p += sctp_adaption_code_param(sctp, (uchar_t *)p);
627 	if (initcollision)
628 		p += sctp_supaddr_param(sctp, (uchar_t *)p);
629 	if (!linklocal)
630 		p += sctp_addr_params(sctp, supp_af, (uchar_t *)p, B_FALSE);
631 	if (((sctp_options & SCTP_PRSCTP_OPTION) || initcollision) &&
632 	    sctp->sctp_prsctp_aware && sctps->sctps_prsctp_enabled) {
633 		p += sctp_options_param(sctp, p, SCTP_PRSCTP_OPTION);
634 	}
635 	/*
636 	 * Generate and lay in the COOKIE parameter.
637 	 *
638 	 * Any change here that results in a change of location for
639 	 * the peer's orig source address must be propagated to the fn
640 	 * cl_sctp_cookie_paddr() above.
641 	 *
642 	 * The cookie consists of:
643 	 * 1. The relative timestamp for the cookie (lbolt64)
644 	 * 2. The cookie lifetime (uint32_t) in tick
645 	 * 3. The local tie-tag
646 	 * 4. The peer tie-tag
647 	 * 5. Peer's original src, used to confirm the validity of address.
648 	 * 6. Our INIT ACK chunk, less any parameters
649 	 * 7. The INIT chunk (may contain parameters)
650 	 * 8. 128-bit MD5 signature.
651 	 *
652 	 * Since the timestamp values will only be evaluated locally, we
653 	 * don't need to worry about byte-ordering them.
654 	 */
655 	cookieph = (sctp_parm_hdr_t *)p;
656 	cookieph->sph_type = htons(PARM_COOKIE);
657 	cookieph->sph_len = htons(cookielen);
658 
659 	/* timestamp */
660 	now = (int64_t *)(cookieph + 1);
661 	nowt = lbolt64;
662 	bcopy(&nowt, now, sizeof (*now));
663 
664 	/* cookie lifetime -- need configuration */
665 	lifetime = (uint32_t *)(now + 1);
666 	*lifetime = sctp->sctp_cookie_lifetime;
667 
668 	/* Set the tie-tags */
669 	ttag = (uint32_t *)(lifetime + 1);
670 	if (sctp->sctp_state <= SCTPS_COOKIE_WAIT) {
671 		*ttag = 0;
672 		ttag++;
673 		*ttag = 0;
674 		ttag++;
675 	} else {
676 		/* local tie-tag (network byte-order) */
677 		*ttag = sctp->sctp_lvtag;
678 		ttag++;
679 		/* peer tie-tag (network byte-order) */
680 		*ttag = sctp->sctp_fvtag;
681 		ttag++;
682 	}
683 	/*
684 	 * Copy in peer's original source address so that we can confirm
685 	 * the reachability later.
686 	 */
687 	p = (char *)ttag;
688 	if (isv4) {
689 		in6_addr_t peer_addr;
690 
691 		IN6_IPADDR_TO_V4MAPPED(iackiph->ipha_dst, &peer_addr);
692 		bcopy(&peer_addr, p, sizeof (in6_addr_t));
693 	} else {
694 		bcopy(&iackip6h->ip6_dst, p, sizeof (in6_addr_t));
695 	}
696 	p += sizeof (in6_addr_t);
697 	/* Copy in our INIT ACK chunk */
698 	bcopy(iack, p, sizeof (*iack));
699 	iack = (sctp_init_chunk_t *)p;
700 	/* Set the # of streams we'll end up using */
701 	iack->sic_outstr = MIN(sctp->sctp_num_ostr, ntohs(init->sic_instr));
702 	iack->sic_instr = MIN(sctp->sctp_num_istr, ntohs(init->sic_outstr));
703 	p += sizeof (*iack);
704 
705 	/* Copy in the peer's INIT chunk */
706 	bcopy(ch, p, ntohs(ch->sch_len));
707 	p += ntohs(ch->sch_len);
708 
709 	/*
710 	 * Calculate the HMAC ICV into the digest slot in buf.
711 	 * First, generate a new secret if the current secret is
712 	 * older than the new secret lifetime parameter permits,
713 	 * copying the current secret to sctp_old_secret.
714 	 */
715 	if (sctps->sctps_new_secret_interval > 0 &&
716 	    (sctp->sctp_last_secret_update +
717 	    MSEC_TO_TICK(sctps->sctps_new_secret_interval)) <= nowt) {
718 		bcopy(sctp->sctp_secret, sctp->sctp_old_secret,
719 		    SCTP_SECRET_LEN);
720 		(void) random_get_pseudo_bytes(sctp->sctp_secret,
721 		    SCTP_SECRET_LEN);
722 		sctp->sctp_last_secret_update = nowt;
723 	}
724 
725 	hmac_md5((uchar_t *)now, cookielen - sizeof (*cookieph) - 16,
726 	    (uchar_t *)sctp->sctp_secret, SCTP_SECRET_LEN, (uchar_t *)p);
727 
728 	iackmp->b_wptr = iackmp->b_rptr + ipsctplen;
729 	iackmp->b_cont = errmp;		/*  OK if NULL */
730 
731 	if (is_system_labeled() && (cr = DB_CRED(iackmp)) != NULL &&
732 	    crgetlabel(cr) != NULL) {
733 		conn_t *connp = sctp->sctp_connp;
734 		int err, adjust;
735 
736 		if (isv4)
737 			err = tsol_check_label(cr, &iackmp, &adjust,
738 			    connp->conn_mac_exempt,
739 			    sctps->sctps_netstack->netstack_ip);
740 		else
741 			err = tsol_check_label_v6(cr, &iackmp, &adjust,
742 			    connp->conn_mac_exempt,
743 			    sctps->sctps_netstack->netstack_ip);
744 		if (err != 0) {
745 			sctp_send_abort(sctp, sctp_init2vtag(ch),
746 			    SCTP_ERR_AUTH_ERR, NULL, 0, initmp, 0, B_FALSE);
747 			freemsg(iackmp);
748 			return;
749 		}
750 		if (isv4) {
751 			iackiph = (ipha_t *)iackmp->b_rptr;
752 			adjust += ntohs(iackiph->ipha_length);
753 			iackiph->ipha_length = htons(adjust);
754 		}
755 	}
756 
757 	/*
758 	 * Stash the conn ptr info. for IP only as e don't have any
759 	 * cached IRE.
760 	 */
761 	SCTP_STASH_IPINFO(iackmp, (ire_t *)NULL);
762 
763 	/* XXX sctp == sctp_g_q, so using its obchunks is valid */
764 	BUMP_LOCAL(sctp->sctp_opkts);
765 	BUMP_LOCAL(sctp->sctp_obchunks);
766 
767 	/* OK to call IP_PUT() here instead of sctp_add_sendq(). */
768 	CONN_INC_REF(sctp->sctp_connp);
769 	iackmp->b_flag |= MSGHASREF;
770 	IP_PUT(iackmp, sctp->sctp_connp, isv4);
771 }
772 
773 void
774 sctp_send_cookie_ack(sctp_t *sctp)
775 {
776 	sctp_chunk_hdr_t *cach;
777 	mblk_t *camp;
778 	sctp_stack_t	*sctps = sctp->sctp_sctps;
779 
780 	camp = sctp_make_mp(sctp, NULL, sizeof (*cach));
781 	if (camp == NULL) {
782 		/* XXX should abort, but don't have the inmp anymore */
783 		SCTP_KSTAT(sctps, sctp_send_cookie_ack_failed);
784 		return;
785 	}
786 
787 	cach = (sctp_chunk_hdr_t *)camp->b_wptr;
788 	camp->b_wptr = (uchar_t *)(cach + 1);
789 	cach->sch_id = CHUNK_COOKIE_ACK;
790 	cach->sch_flags = 0;
791 	cach->sch_len = htons(sizeof (*cach));
792 
793 	sctp_set_iplen(sctp, camp);
794 
795 	BUMP_LOCAL(sctp->sctp_obchunks);
796 
797 	sctp_add_sendq(sctp, camp);
798 }
799 
800 static int
801 sctp_find_al_ind(sctp_parm_hdr_t *sph, ssize_t len, uint32_t *adaption_code)
802 {
803 
804 	if (len < sizeof (*sph))
805 		return (-1);
806 	while (sph != NULL) {
807 		if (sph->sph_type == htons(PARM_ADAPT_LAYER_IND) &&
808 		    ntohs(sph->sph_len) >= (sizeof (*sph) +
809 			sizeof (uint32_t))) {
810 			*adaption_code = *(uint32_t *)(sph + 1);
811 			return (0);
812 		}
813 		sph = sctp_next_parm(sph, &len);
814 	}
815 	return (-1);
816 }
817 
818 void
819 sctp_send_cookie_echo(sctp_t *sctp, sctp_chunk_hdr_t *iackch, mblk_t *iackmp)
820 {
821 	mblk_t			*cemp;
822 	mblk_t			*mp = NULL;
823 	mblk_t			*head;
824 	mblk_t			*meta;
825 	sctp_faddr_t		*fp;
826 	sctp_chunk_hdr_t	*cech;
827 	sctp_init_chunk_t	 *iack;
828 	int32_t			cansend;
829 	int32_t			seglen;
830 	size_t			ceclen;
831 	sctp_parm_hdr_t		*cph;
832 	sctp_data_hdr_t		*sdc;
833 	sctp_tf_t		*tf;
834 	int			pad = 0;
835 	int			hdrlen;
836 	mblk_t			*errmp = NULL;
837 	uint_t			sctp_options;
838 	int			error;
839 	uint16_t		old_num_str;
840 	sctp_stack_t		*sctps = sctp->sctp_sctps;
841 
842 	iack = (sctp_init_chunk_t *)(iackch + 1);
843 
844 	cph = NULL;
845 	if (validate_init_params(sctp, iackch, iack, iackmp, &cph, &errmp,
846 	    &pad, &sctp_options) == 0) { /* result in 'pad' ignored */
847 		BUMP_MIB(&sctps->sctps_mib, sctpAborted);
848 		sctp_assoc_event(sctp, SCTP_CANT_STR_ASSOC, 0, NULL);
849 		sctp_clean_death(sctp, ECONNABORTED);
850 		return;
851 	}
852 	ASSERT(cph != NULL);
853 
854 	ASSERT(sctp->sctp_cookie_mp == NULL);
855 
856 	/* Got a cookie to echo back; allocate an mblk */
857 	ceclen = sizeof (*cech) + ntohs(cph->sph_len) - sizeof (*cph);
858 	if ((pad = ceclen & (SCTP_ALIGN - 1)) != 0)
859 		pad = SCTP_ALIGN - pad;
860 
861 	if (IPH_HDR_VERSION(iackmp->b_rptr) == IPV4_VERSION)
862 		hdrlen = sctp->sctp_hdr_len;
863 	else
864 		hdrlen = sctp->sctp_hdr6_len;
865 
866 	cemp = allocb(sctps->sctps_wroff_xtra + hdrlen + ceclen + pad,
867 	    BPRI_MED);
868 	if (cemp == NULL) {
869 		SCTP_FADDR_TIMER_RESTART(sctp, sctp->sctp_current,
870 		    sctp->sctp_current->rto);
871 		if (errmp != NULL)
872 			freeb(errmp);
873 		return;
874 	}
875 	cemp->b_rptr += (sctps->sctps_wroff_xtra + hdrlen);
876 
877 	/* Process the INIT ACK */
878 	sctp->sctp_sctph->sh_verf = iack->sic_inittag;
879 	sctp->sctp_sctph6->sh_verf = iack->sic_inittag;
880 	sctp->sctp_fvtag = iack->sic_inittag;
881 	sctp->sctp_ftsn = ntohl(iack->sic_inittsn);
882 	sctp->sctp_lastacked = sctp->sctp_ftsn - 1;
883 	sctp->sctp_fcsn = sctp->sctp_lastacked;
884 	sctp->sctp_frwnd = ntohl(iack->sic_a_rwnd);
885 
886 	/*
887 	 * Populate sctp with addresses given in the INIT ACK or IP header.
888 	 * Need to set the df bit in the current fp as it has been cleared
889 	 * in sctp_connect().
890 	 */
891 	sctp->sctp_current->df = B_TRUE;
892 	/*
893 	 * Since IP uses this info during the fanout process, we need to hold
894 	 * the lock for this hash line while performing this operation.
895 	 */
896 	/* XXX sctp_conn_fanout + SCTP_CONN_HASH(sctps, sctp->sctp_ports); */
897 	ASSERT(sctp->sctp_conn_tfp != NULL);
898 	tf = sctp->sctp_conn_tfp;
899 	/* sctp isn't a listener so only need to hold conn fanout lock */
900 	mutex_enter(&tf->tf_lock);
901 	if (sctp_get_addrparams(sctp, NULL, iackmp, iackch, NULL) != 0) {
902 		mutex_exit(&tf->tf_lock);
903 		freeb(cemp);
904 		SCTP_FADDR_TIMER_RESTART(sctp, sctp->sctp_current,
905 		    sctp->sctp_current->rto);
906 		if (errmp != NULL)
907 			freeb(errmp);
908 		return;
909 	}
910 	mutex_exit(&tf->tf_lock);
911 
912 	fp = sctp->sctp_current;
913 
914 	/*
915 	 * There could be a case when we get an INIT-ACK again, if the INIT
916 	 * is re-transmitted, for e.g., which means we would have already
917 	 * allocated this resource earlier (also for sctp_instr). In this
918 	 * case we check and re-allocate, if necessary.
919 	 */
920 	old_num_str = sctp->sctp_num_ostr;
921 	if (ntohs(iack->sic_instr) < sctp->sctp_num_ostr)
922 		sctp->sctp_num_ostr = ntohs(iack->sic_instr);
923 	if (sctp->sctp_ostrcntrs == NULL) {
924 		sctp->sctp_ostrcntrs = kmem_zalloc(sizeof (uint16_t) *
925 		    sctp->sctp_num_ostr, KM_NOSLEEP);
926 	} else {
927 		ASSERT(old_num_str > 0);
928 		if (old_num_str != sctp->sctp_num_ostr) {
929 			kmem_free(sctp->sctp_ostrcntrs, sizeof (uint16_t) *
930 			    old_num_str);
931 			sctp->sctp_ostrcntrs = kmem_zalloc(sizeof (uint16_t) *
932 			    sctp->sctp_num_ostr, KM_NOSLEEP);
933 		}
934 	}
935 	if (sctp->sctp_ostrcntrs == NULL) {
936 		freeb(cemp);
937 		SCTP_FADDR_TIMER_RESTART(sctp, fp, fp->rto);
938 		if (errmp != NULL)
939 			freeb(errmp);
940 		return;
941 	}
942 
943 	/*
944 	 * Allocate the in stream tracking array. Comments for sctp_ostrcntrs
945 	 * hold here too.
946 	 */
947 	old_num_str = sctp->sctp_num_istr;
948 	if (ntohs(iack->sic_outstr) < sctp->sctp_num_istr)
949 		sctp->sctp_num_istr = ntohs(iack->sic_outstr);
950 	if (sctp->sctp_instr == NULL) {
951 		sctp->sctp_instr = kmem_zalloc(sizeof (*sctp->sctp_instr) *
952 		    sctp->sctp_num_istr, KM_NOSLEEP);
953 	} else {
954 		ASSERT(old_num_str > 0);
955 		if (old_num_str != sctp->sctp_num_istr) {
956 			kmem_free(sctp->sctp_instr,
957 			    sizeof (*sctp->sctp_instr) * old_num_str);
958 			sctp->sctp_instr = kmem_zalloc(
959 			    sizeof (*sctp->sctp_instr) * sctp->sctp_num_istr,
960 			    KM_NOSLEEP);
961 		}
962 	}
963 	if (sctp->sctp_instr == NULL) {
964 		kmem_free(sctp->sctp_ostrcntrs,
965 		    sizeof (uint16_t) * sctp->sctp_num_ostr);
966 		freeb(cemp);
967 		SCTP_FADDR_TIMER_RESTART(sctp, fp, fp->rto);
968 		if (errmp != NULL)
969 			freeb(errmp);
970 		return;
971 	}
972 
973 	if (!(sctp_options & SCTP_PRSCTP_OPTION) && sctp->sctp_prsctp_aware)
974 		sctp->sctp_prsctp_aware = B_FALSE;
975 
976 	if (sctp_find_al_ind((sctp_parm_hdr_t *)(iack + 1),
977 		ntohs(iackch->sch_len) - (sizeof (*iackch) + sizeof (*iack)),
978 		&sctp->sctp_rx_adaption_code) == 0) {
979 		sctp->sctp_recv_adaption = 1;
980 	}
981 
982 	cech = (sctp_chunk_hdr_t *)cemp->b_rptr;
983 	ASSERT(OK_32PTR(cech));
984 	cech->sch_id = CHUNK_COOKIE;
985 	cech->sch_flags = 0;
986 	cech->sch_len = htons(ceclen);
987 
988 	/* Copy the cookie (less the parm hdr) to the chunk */
989 	bcopy(cph + 1, cech + 1, ceclen - sizeof (*cph));
990 
991 	cemp->b_wptr = cemp->b_rptr + ceclen;
992 
993 	if (sctp->sctp_unsent > 0) {
994 		sctp_msg_hdr_t	*smh;
995 		mblk_t		*prev = NULL;
996 		uint32_t	unsent = 0;
997 
998 		mp = sctp->sctp_xmit_unsent;
999 		do {
1000 			smh = (sctp_msg_hdr_t *)mp->b_rptr;
1001 			if (smh->smh_sid >= sctp->sctp_num_ostr) {
1002 				unsent += smh->smh_msglen;
1003 				if (prev != NULL)
1004 					prev->b_next = mp->b_next;
1005 				else
1006 					sctp->sctp_xmit_unsent = mp->b_next;
1007 				mp->b_next = NULL;
1008 				sctp_sendfail_event(sctp, mp, SCTP_ERR_BAD_SID,
1009 				    B_FALSE);
1010 				if (prev != NULL)
1011 					mp = prev->b_next;
1012 				else
1013 					mp = sctp->sctp_xmit_unsent;
1014 			} else {
1015 				prev = mp;
1016 				mp = mp->b_next;
1017 			}
1018 		} while (mp != NULL);
1019 		if (unsent > 0) {
1020 			ASSERT(sctp->sctp_unsent >= unsent);
1021 			sctp->sctp_unsent -= unsent;
1022 			/*
1023 			 * Update ULP the amount of queued data, which is
1024 			 * sent-unack'ed + unsent.
1025 			 * This is not necessary, but doesn't harm, we
1026 			 * just use unsent instead of sent-unack'ed +
1027 			 * unsent, since there won't be any sent-unack'ed
1028 			 * here.
1029 			 */
1030 			if (!SCTP_IS_DETACHED(sctp)) {
1031 				sctp->sctp_ulp_xmitted(sctp->sctp_ulpd,
1032 				    sctp->sctp_unsent);
1033 			}
1034 		}
1035 		if (sctp->sctp_xmit_unsent == NULL)
1036 			sctp->sctp_xmit_unsent_tail = NULL;
1037 	}
1038 	ceclen += pad;
1039 	cansend = MIN(sctp->sctp_unsent, sctp->sctp_frwnd);
1040 	meta = sctp_get_msg_to_send(sctp, &mp, NULL, &error, ceclen,
1041 	    cansend,  NULL);
1042 	/*
1043 	 * The error cannot be anything else since we could have an non-zero
1044 	 * error only if sctp_get_msg_to_send() tries to send a Forward
1045 	 * TSN which will not happen here.
1046 	 */
1047 	ASSERT(error == 0);
1048 	if (meta == NULL)
1049 		goto sendcookie;
1050 	sctp->sctp_xmit_tail = meta;
1051 	sdc = (sctp_data_hdr_t *)mp->b_rptr;
1052 	seglen = ntohs(sdc->sdh_len);
1053 	if ((ceclen + seglen) > fp->sfa_pmss ||
1054 	    (seglen - sizeof (*sdc)) > cansend) {
1055 		goto sendcookie;
1056 	}
1057 	/* OK, if this fails */
1058 	cemp->b_cont = dupmsg(mp);
1059 sendcookie:
1060 	head = sctp_add_proto_hdr(sctp, fp, cemp, 0, NULL);
1061 	if (head == NULL) {
1062 		freemsg(cemp);
1063 		SCTP_FADDR_TIMER_RESTART(sctp, fp, fp->rto);
1064 		if (errmp != NULL)
1065 			freeb(errmp);
1066 		SCTP_KSTAT(sctps, sctp_send_cookie_failed);
1067 		return;
1068 	}
1069 	/*
1070 	 * Even if cookie-echo exceeds MTU for one of the hops, it'll
1071 	 * have a chance of getting there.
1072 	 */
1073 	if (fp->isv4) {
1074 		ipha_t *iph = (ipha_t *)head->b_rptr;
1075 		iph->ipha_fragment_offset_and_flags = 0;
1076 	}
1077 	BUMP_LOCAL(sctp->sctp_obchunks);
1078 
1079 	sctp->sctp_cookie_mp = dupmsg(head);
1080 	/* Don't bundle, we will just resend init if this cookie is lost. */
1081 	if (sctp->sctp_cookie_mp == NULL) {
1082 		if (cemp->b_cont != NULL) {
1083 			freemsg(cemp->b_cont);
1084 			cemp->b_cont = NULL;
1085 		}
1086 	} else if (cemp->b_cont != NULL) {
1087 		ASSERT(mp != NULL && mp == meta->b_cont);
1088 		SCTP_CHUNK_CLEAR_FLAGS(cemp->b_cont);
1089 		cemp->b_wptr += pad;
1090 		seglen -= sizeof (*sdc);
1091 		SCTP_CHUNK_SENT(sctp, mp, sdc, fp, seglen, meta);
1092 	}
1093 	if (errmp != NULL)
1094 		linkb(head, errmp);
1095 	sctp->sctp_state = SCTPS_COOKIE_ECHOED;
1096 	SCTP_FADDR_TIMER_RESTART(sctp, fp, fp->rto);
1097 
1098 	sctp_set_iplen(sctp, head);
1099 	sctp_add_sendq(sctp, head);
1100 }
1101 
1102 int
1103 sctp_process_cookie(sctp_t *sctp, sctp_chunk_hdr_t *ch, mblk_t *cmp,
1104     sctp_init_chunk_t **iackpp, sctp_hdr_t *insctph, int *recv_adaption,
1105     in6_addr_t *peer_addr)
1106 {
1107 	int32_t			clen;
1108 	size_t			initplen;
1109 	uchar_t			*p;
1110 	uchar_t			*given_hash;
1111 	uchar_t			needed_hash[16];
1112 	int64_t			ts;
1113 	int64_t			diff;
1114 	uint32_t		*lt;
1115 	sctp_init_chunk_t	*iack;
1116 	sctp_chunk_hdr_t	*initch;
1117 	sctp_init_chunk_t	*init;
1118 	uint32_t		*lttag;
1119 	uint32_t		*fttag;
1120 	uint32_t		ports;
1121 	sctp_stack_t		*sctps = sctp->sctp_sctps;
1122 
1123 	BUMP_LOCAL(sctp->sctp_ibchunks);
1124 	/* Verify the ICV */
1125 	clen = ntohs(ch->sch_len) - sizeof (*ch) - 16;
1126 	if (clen < 0) {
1127 		dprint(1, ("invalid cookie chunk length %d\n",
1128 		    ntohs(ch->sch_len)));
1129 
1130 		return (-1);
1131 	}
1132 	p = (uchar_t *)(ch + 1);
1133 
1134 	hmac_md5(p, clen, (uchar_t *)sctp->sctp_secret, SCTP_SECRET_LEN,
1135 	    needed_hash);
1136 
1137 	/* The given hash follows the cookie data */
1138 	given_hash = p + clen;
1139 
1140 	if (bcmp(given_hash, needed_hash, 16) != 0) {
1141 		/* The secret may have changed; try the old secret */
1142 		hmac_md5(p, clen, (uchar_t *)sctp->sctp_old_secret,
1143 		    SCTP_SECRET_LEN, needed_hash);
1144 		if (bcmp(given_hash, needed_hash, 16) != 0) {
1145 			return (-1);
1146 		}
1147 	}
1148 
1149 	/* Timestamp is int64_t, and we only guarantee 32-bit alignment */
1150 	bcopy(p, &ts, sizeof (ts));
1151 	/* Cookie life time, uint32_t */
1152 	lt = (uint32_t *)(p + sizeof (ts));
1153 
1154 	/*
1155 	 * To quote PRC, "this is our baby", so let's continue.
1156 	 * We need to pull out the encapsulated INIT ACK and
1157 	 * INIT chunks. Note that we don't process these until
1158 	 * we have verified the timestamp, but we need them before
1159 	 * processing the timestamp since if the time check fails,
1160 	 * we need to get the verification tag from the INIT in order
1161 	 * to send a stale cookie error.
1162 	 */
1163 	lttag = (uint32_t *)(lt + 1);
1164 	fttag = lttag + 1;
1165 	if (peer_addr != NULL)
1166 		bcopy(fttag + 1, peer_addr, sizeof (in6_addr_t));
1167 	iack = (sctp_init_chunk_t *)((char *)(fttag + 1) + sizeof (in6_addr_t));
1168 	initch = (sctp_chunk_hdr_t *)(iack + 1);
1169 	init = (sctp_init_chunk_t *)(initch + 1);
1170 	initplen = ntohs(initch->sch_len) - (sizeof (*init) + sizeof (*initch));
1171 	*iackpp = iack;
1172 	*recv_adaption = 0;
1173 
1174 	/*
1175 	 * Check the staleness of the Cookie, specified in 3.3.10.3 of
1176 	 * RFC 2960.
1177 	 *
1178 	 * The mesaure of staleness is the difference, in microseconds,
1179 	 * between the current time and the time the State Cookie expires.
1180 	 * So it is lbolt64 - (ts + *lt).  If it is positive, it means
1181 	 * that the Cookie has expired.
1182 	 */
1183 	diff = lbolt64 - (ts + *lt);
1184 	if (diff > 0 && (init->sic_inittag != sctp->sctp_fvtag ||
1185 	    iack->sic_inittag != sctp->sctp_lvtag)) {
1186 		uint32_t staleness;
1187 
1188 		staleness = TICK_TO_USEC(diff);
1189 		staleness = htonl(staleness);
1190 		sctp_send_abort(sctp, init->sic_inittag, SCTP_ERR_STALE_COOKIE,
1191 		    (char *)&staleness, sizeof (staleness), cmp, 1, B_FALSE);
1192 
1193 		dprint(1, ("stale cookie %d\n", staleness));
1194 
1195 		return (-1);
1196 	}
1197 
1198 	/* Check for attack by adding addresses to a restart */
1199 	bcopy(insctph, &ports, sizeof (ports));
1200 	if (sctp_secure_restart_check(cmp, initch, ports, KM_NOSLEEP,
1201 	    sctps) != 1) {
1202 		return (-1);
1203 	}
1204 
1205 	/* Look for adaptation code if there any parms in the INIT chunk */
1206 	if ((initplen >= sizeof (sctp_parm_hdr_t)) &&
1207 	    (sctp_find_al_ind((sctp_parm_hdr_t *)(init + 1), initplen,
1208 	    &sctp->sctp_rx_adaption_code) == 0)) {
1209 		*recv_adaption = 1;
1210 	}
1211 
1212 	/* Examine tie-tags */
1213 
1214 	if (sctp->sctp_state >= SCTPS_COOKIE_WAIT) {
1215 		if (sctp->sctp_state == SCTPS_ESTABLISHED &&
1216 		    init->sic_inittag == sctp->sctp_fvtag &&
1217 		    iack->sic_inittag == sctp->sctp_lvtag &&
1218 		    *fttag == 0 && *lttag == 0) {
1219 
1220 			dprint(1, ("duplicate cookie from %x:%x:%x:%x (%d)\n",
1221 			    SCTP_PRINTADDR(sctp->sctp_current->faddr),
1222 			    (int)(sctp->sctp_fport)));
1223 			return (-1);
1224 		}
1225 
1226 		if (init->sic_inittag != sctp->sctp_fvtag &&
1227 		    iack->sic_inittag != sctp->sctp_lvtag &&
1228 		    *fttag == sctp->sctp_fvtag &&
1229 		    *lttag == sctp->sctp_lvtag) {
1230 			int i;
1231 
1232 			/* Section 5.2.4 case A: restart */
1233 			sctp->sctp_fvtag = init->sic_inittag;
1234 			sctp->sctp_lvtag = iack->sic_inittag;
1235 
1236 			sctp->sctp_sctph->sh_verf = init->sic_inittag;
1237 			sctp->sctp_sctph6->sh_verf = init->sic_inittag;
1238 
1239 			sctp->sctp_ftsn = ntohl(init->sic_inittsn);
1240 			sctp->sctp_lastacked = sctp->sctp_ftsn - 1;
1241 			sctp->sctp_frwnd = ntohl(init->sic_a_rwnd);
1242 			sctp->sctp_fcsn = sctp->sctp_lastacked;
1243 
1244 			if (sctp->sctp_state < SCTPS_ESTABLISHED) {
1245 				sctp->sctp_state = SCTPS_ESTABLISHED;
1246 				sctp->sctp_assoc_start_time = (uint32_t)lbolt;
1247 			}
1248 
1249 			dprint(1, ("sctp peer %x:%x:%x:%x (%d) restarted\n",
1250 			    SCTP_PRINTADDR(sctp->sctp_current->faddr),
1251 			    (int)(sctp->sctp_fport)));
1252 			/* reset parameters */
1253 			sctp_congest_reset(sctp);
1254 
1255 			/* reset stream bookkeeping */
1256 			sctp_instream_cleanup(sctp, B_FALSE);
1257 
1258 			sctp->sctp_istr_nmsgs = 0;
1259 			sctp->sctp_rxqueued = 0;
1260 			for (i = 0; i < sctp->sctp_num_ostr; i++) {
1261 				sctp->sctp_ostrcntrs[i] = 0;
1262 			}
1263 			/* XXX flush xmit_list? */
1264 
1265 			return (0);
1266 		} else if (init->sic_inittag != sctp->sctp_fvtag &&
1267 		    iack->sic_inittag == sctp->sctp_lvtag) {
1268 
1269 			/* Section 5.2.4 case B: INIT collision */
1270 			if (sctp->sctp_state < SCTPS_ESTABLISHED) {
1271 				if (!sctp_initialize_params(sctp, init, iack))
1272 					return (-1);	/* Drop? */
1273 				sctp->sctp_state = SCTPS_ESTABLISHED;
1274 				sctp->sctp_assoc_start_time = (uint32_t)lbolt;
1275 			}
1276 
1277 			dprint(1, ("init collision with %x:%x:%x:%x (%d)\n",
1278 			    SCTP_PRINTADDR(sctp->sctp_current->faddr),
1279 			    (int)(sctp->sctp_fport)));
1280 
1281 			return (0);
1282 		} else if (iack->sic_inittag != sctp->sctp_lvtag &&
1283 		    init->sic_inittag == sctp->sctp_fvtag &&
1284 		    *fttag == 0 && *lttag == 0) {
1285 
1286 			/* Section 5.2.4 case C: late COOKIE */
1287 			dprint(1, ("late cookie from %x:%x:%x:%x (%d)\n",
1288 			    SCTP_PRINTADDR(sctp->sctp_current->faddr),
1289 			    (int)(sctp->sctp_fport)));
1290 			return (-1);
1291 		} else if (init->sic_inittag == sctp->sctp_fvtag &&
1292 		    iack->sic_inittag == sctp->sctp_lvtag) {
1293 
1294 			/*
1295 			 * Section 5.2.4 case D: COOKIE ECHO retransmit
1296 			 * Don't check cookie lifetime
1297 			 */
1298 			dprint(1, ("cookie tags match from %x:%x:%x:%x (%d)\n",
1299 			    SCTP_PRINTADDR(sctp->sctp_current->faddr),
1300 			    (int)(sctp->sctp_fport)));
1301 			if (sctp->sctp_state < SCTPS_ESTABLISHED) {
1302 				if (!sctp_initialize_params(sctp, init, iack))
1303 					return (-1);	/* Drop? */
1304 				sctp->sctp_state = SCTPS_ESTABLISHED;
1305 				sctp->sctp_assoc_start_time = (uint32_t)lbolt;
1306 			}
1307 			return (0);
1308 		} else {
1309 			/* unrecognized case -- silently drop it */
1310 			return (-1);
1311 		}
1312 	}
1313 
1314 	return (0);
1315 }
1316 
1317 /*
1318  * Similar to ip_fanout_sctp, except that the src addr(s) are drawn
1319  * from address parameters in an INIT ACK's address list. This
1320  * function is used when an INIT ACK is received but IP's fanout
1321  * function could not find a sctp via the normal lookup routine.
1322  * This can happen when a host sends an INIT ACK from a different
1323  * address than the INIT was sent to.
1324  *
1325  * Returns the sctp_t if found, or NULL if not found.
1326  */
1327 sctp_t *
1328 sctp_addrlist2sctp(mblk_t *mp, sctp_hdr_t *sctph, sctp_chunk_hdr_t *ich,
1329     zoneid_t zoneid, sctp_stack_t *sctps)
1330 {
1331 	int isv4;
1332 	ipha_t *iph;
1333 	ip6_t *ip6h;
1334 	in6_addr_t dst;
1335 	in6_addr_t src;
1336 	sctp_parm_hdr_t *ph;
1337 	ssize_t remaining;
1338 	sctp_init_chunk_t *iack;
1339 	uint32_t ports;
1340 	sctp_t *sctp = NULL;
1341 
1342 	ASSERT(ich->sch_id == CHUNK_INIT_ACK);
1343 
1344 	isv4 = (IPH_HDR_VERSION(mp->b_rptr) == IPV4_VERSION);
1345 	if (isv4) {
1346 		iph = (ipha_t *)mp->b_rptr;
1347 		IN6_IPADDR_TO_V4MAPPED(iph->ipha_dst, &dst);
1348 	} else {
1349 		ip6h = (ip6_t *)mp->b_rptr;
1350 		dst = ip6h->ip6_dst;
1351 	}
1352 
1353 	ports = *(uint32_t *)sctph;
1354 
1355 	dprint(1, ("sctp_addrlist2sctp: ports=%u, dst = %x:%x:%x:%x\n",
1356 	    ports, SCTP_PRINTADDR(dst)));
1357 
1358 	/* pull out any address parameters */
1359 	remaining = ntohs(ich->sch_len) - sizeof (*ich) - sizeof (*iack);
1360 	if (remaining < sizeof (*ph)) {
1361 		return (NULL);
1362 	}
1363 
1364 	iack = (sctp_init_chunk_t *)(ich + 1);
1365 	ph = (sctp_parm_hdr_t *)(iack + 1);
1366 
1367 	while (ph != NULL) {
1368 		/*
1369 		 * params have been put in host byteorder by
1370 		 * sctp_check_input()
1371 		 */
1372 		if (ph->sph_type == PARM_ADDR4) {
1373 			IN6_INADDR_TO_V4MAPPED((struct in_addr *)(ph + 1),
1374 			    &src);
1375 
1376 			sctp = sctp_conn_match(&src, &dst, ports, zoneid,
1377 			    sctps);
1378 
1379 			dprint(1,
1380 			    ("sctp_addrlist2sctp: src=%x:%x:%x:%x, sctp=%p\n",
1381 			    SCTP_PRINTADDR(src), (void *)sctp));
1382 
1383 
1384 			if (sctp != NULL) {
1385 				return (sctp);
1386 			}
1387 		} else if (ph->sph_type == PARM_ADDR6) {
1388 			src = *(in6_addr_t *)(ph + 1);
1389 			sctp = sctp_conn_match(&src, &dst, ports, zoneid,
1390 			    sctps);
1391 
1392 			dprint(1,
1393 			    ("sctp_addrlist2sctp: src=%x:%x:%x:%x, sctp=%p\n",
1394 			    SCTP_PRINTADDR(src), (void *)sctp));
1395 
1396 			if (sctp != NULL) {
1397 				return (sctp);
1398 			}
1399 		}
1400 
1401 		ph = sctp_next_parm(ph, &remaining);
1402 	}
1403 
1404 	return (NULL);
1405 }
1406