xref: /titanic_41/usr/src/uts/common/inet/sctp/sctp_cookie.c (revision e11c3f44f531fdff80941ce57c065d2ae861cefc)
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 #include <sys/types.h>
28 #include <sys/systm.h>
29 #include <sys/stream.h>
30 #include <sys/cmn_err.h>
31 #include <sys/md5.h>
32 #include <sys/kmem.h>
33 #include <sys/strsubr.h>
34 #include <sys/random.h>
35 #include <sys/tsol/tnet.h>
36 
37 #include <netinet/in.h>
38 #include <netinet/ip6.h>
39 
40 #include <inet/common.h>
41 #include <inet/ip.h>
42 #include <inet/ip6.h>
43 #include <inet/sctp_ip.h>
44 #include <inet/ipclassifier.h>
45 #include "sctp_impl.h"
46 
47 /*
48  * Helper function for SunCluster (PSARC/2005/602) to get the original source
49  * address from the COOKIE
50  */
51 int cl_sctp_cookie_paddr(sctp_chunk_hdr_t *, in6_addr_t *);
52 
53 /*
54  * From RFC 2104. This should probably go into libmd5 (and while
55  * we're at it, maybe we should make a libdigest so we can later
56  * add SHA1 and others, esp. since some weaknesses have been found
57  * with MD5).
58  *
59  * text		IN			pointer to data stream
60  * text_len	IN			length of data stream
61  * key		IN			pointer to authentication key
62  * key_len	IN			length of authentication key
63  * digest	OUT			caller digest to be filled in
64  */
65 static void
66 hmac_md5(uchar_t *text, size_t text_len, uchar_t *key, size_t key_len,
67     uchar_t *digest)
68 {
69 	MD5_CTX context;
70 	uchar_t k_ipad[65];	/* inner padding - key XORd with ipad */
71 	uchar_t k_opad[65];	/* outer padding - key XORd with opad */
72 	uchar_t tk[16];
73 	int i;
74 
75 	/* if key is longer than 64 bytes reset it to key=MD5(key) */
76 	if (key_len > 64) {
77 		MD5_CTX tctx;
78 
79 		MD5Init(&tctx);
80 		MD5Update(&tctx, key, key_len);
81 		MD5Final(tk, &tctx);
82 
83 		key = tk;
84 		key_len = 16;
85 	}
86 
87 	/*
88 	 * the HMAC_MD5 transform looks like:
89 	 *
90 	 * MD5(K XOR opad, MD5(K XOR ipad, text))
91 	 *
92 	 * where K is an n byte key
93 	 * ipad is the byte 0x36 repeated 64 times
94 	 * opad is the byte 0x5c repeated 64 times
95 	 * and text is the data being protected
96 	 */
97 
98 	/* start out by storing key in pads */
99 	bzero(k_ipad, sizeof (k_ipad));
100 	bzero(k_opad, sizeof (k_opad));
101 	bcopy(key, k_ipad, key_len);
102 	bcopy(key, k_opad, key_len);
103 
104 	/* XOR key with ipad and opad values */
105 	for (i = 0; i < 64; i++) {
106 		k_ipad[i] ^= 0x36;
107 		k_opad[i] ^= 0x5c;
108 	}
109 	/*
110 	 * perform inner MD5
111 	 */
112 	MD5Init(&context);			/* init context for 1st */
113 						/* pass */
114 	MD5Update(&context, k_ipad, 64);	/* start with inner pad */
115 	MD5Update(&context, text, text_len);	/* then text of datagram */
116 	MD5Final(digest, &context);		/* finish up 1st pass */
117 	/*
118 	 * perform outer MD5
119 	 */
120 	MD5Init(&context);			/* init context for 2nd */
121 						/* pass */
122 	MD5Update(&context, k_opad, 64);	/* start with outer pad */
123 	MD5Update(&context, digest, 16);	/* then results of 1st */
124 						/* hash */
125 	MD5Final(digest, &context);		/* finish up 2nd pass */
126 }
127 
128 /*
129  * If inmp is non-NULL, and we need to abort, it will use the IP/SCTP
130  * info in initmp to send the abort. Otherwise, no abort will be sent.
131  *
132  * An ERROR chunk and chain of one or more error cause blocks will be
133  * created if unrecognized parameters marked by the sender as reportable
134  * are found. This error chain is visible to the caller via *errmp.
135  *
136  * When called from stcp_send_init_ack() while processing parameters
137  * from a received INIT_CHUNK want_cookie will be NULL.
138  *
139  * When called from sctp_send_cookie_echo() while processing an INIT_ACK,
140  * want_cookie contains a pointer to a pointer of type *sctp_parm_hdr_t.
141  * However, this last pointer will be NULL until the cookie is processed
142  * at which time it will be set to point to a sctp_parm_hdr_t that contains
143  * the cookie info.
144  *
145  * Note: an INIT_ACK is expected to contain a cookie.
146  *
147  * Returns 1 if the parameters are OK (or if there are no optional
148  * parameters), returns 0 otherwise.
149  */
150 static int
151 validate_init_params(sctp_t *sctp, sctp_chunk_hdr_t *ch,
152     sctp_init_chunk_t *init, mblk_t *inmp, sctp_parm_hdr_t **want_cookie,
153     mblk_t **errmp, int *supp_af, uint_t *sctp_options)
154 {
155 	sctp_parm_hdr_t		*cph;
156 	sctp_init_chunk_t	*ic;
157 	ssize_t			remaining;
158 	uint16_t		serror = 0;
159 	char			*details = NULL;
160 	size_t			errlen = 0;
161 	boolean_t		got_cookie = B_FALSE;
162 	boolean_t		got_errchunk = B_FALSE;
163 	uint16_t		ptype;
164 
165 	ASSERT(errmp != NULL);
166 
167 	if (sctp_options != NULL)
168 		*sctp_options = 0;
169 
170 	/* First validate stream parameters */
171 	if (init->sic_instr == 0 || init->sic_outstr == 0) {
172 		serror = SCTP_ERR_BAD_MANDPARM;
173 		dprint(1, ("validate_init_params: bad sid, is=%d os=%d\n",
174 		    htons(init->sic_instr), htons(init->sic_outstr)));
175 		goto abort;
176 	}
177 	if (ntohl(init->sic_inittag) == 0) {
178 		serror = SCTP_ERR_BAD_MANDPARM;
179 		dprint(1, ("validate_init_params: inittag = 0\n"));
180 		goto abort;
181 	}
182 
183 	remaining = ntohs(ch->sch_len) - sizeof (*ch);
184 	ic = (sctp_init_chunk_t *)(ch + 1);
185 	remaining -= sizeof (*ic);
186 	if (remaining < sizeof (*cph)) {
187 		/*
188 		 * When processing a received INIT_ACK, a cookie is
189 		 * expected, if missing there is nothing to validate.
190 		 */
191 		if (want_cookie != NULL)
192 			goto cookie_abort;
193 		return (1);
194 	}
195 
196 	cph = (sctp_parm_hdr_t *)(ic + 1);
197 
198 	while (cph != NULL) {
199 		ptype = ntohs(cph->sph_type);
200 		switch (ptype) {
201 		case PARM_HBINFO:
202 		case PARM_UNRECOGNIZED:
203 		case PARM_ECN:
204 			/* just ignore them */
205 			break;
206 		case PARM_FORWARD_TSN:
207 			if (sctp_options != NULL)
208 				*sctp_options |= SCTP_PRSCTP_OPTION;
209 			break;
210 		case PARM_COOKIE:
211 			got_cookie = B_TRUE;
212 			/*
213 			 * Processing a received INIT_ACK, we have a cookie
214 			 * and a valid pointer in our caller to attach it to.
215 			 */
216 			if (want_cookie != NULL) {
217 				*want_cookie = cph;
218 			}
219 			break;
220 		case PARM_ADDR4:
221 			*supp_af |= PARM_SUPP_V4;
222 			break;
223 		case PARM_ADDR6:
224 			*supp_af |= PARM_SUPP_V6;
225 			break;
226 		case PARM_COOKIE_PRESERVE:
227 		case PARM_ADAPT_LAYER_IND:
228 			/* These are OK */
229 			break;
230 		case PARM_ADDR_HOST_NAME:
231 			/* Don't support this; abort the association */
232 			serror = SCTP_ERR_BAD_ADDR;
233 			details = (char *)cph;
234 			errlen = ntohs(cph->sph_len);
235 			dprint(1, ("sctp:validate_init_params: host addr\n"));
236 			goto abort;
237 		case PARM_SUPP_ADDRS: {
238 			/* Make sure we have a supported addr intersection */
239 			uint16_t *p, addrtype;
240 			int plen;
241 
242 			plen = ntohs(cph->sph_len);
243 			p = (uint16_t *)(cph + 1);
244 			while (plen > 0) {
245 				addrtype = ntohs(*p);
246 				switch (addrtype) {
247 				case PARM_ADDR6:
248 					*supp_af |= PARM_SUPP_V6;
249 					break;
250 				case PARM_ADDR4:
251 					*supp_af |= PARM_SUPP_V4;
252 					break;
253 				default:
254 					/*
255 					 * Do nothing, silently ignore hostname
256 					 * address.
257 					 */
258 					break;
259 				}
260 				p++;
261 				plen -= sizeof (*p);
262 			}
263 			break;
264 		}
265 		default:
266 			/*
267 			 * Handle any unrecognized params, the two high order
268 			 * bits of ptype define how the remote wants them
269 			 * handled.
270 			 * Top bit:
271 			 *    1. Continue processing other params in the chunk
272 			 *    0. Stop processing params after this one.
273 			 * 2nd bit:
274 			 *    1. Must report this unrecognized param to remote
275 			 *    0. Obey the top bit silently.
276 			 */
277 			if (ptype & SCTP_REPORT_THIS_PARAM) {
278 				if (!got_errchunk) {
279 					/*
280 					 * First reportable param, create an
281 					 * ERROR chunk and populate it with a
282 					 * cause block for this parameter.
283 					 */
284 					*errmp = sctp_make_err(sctp,
285 					    PARM_UNRECOGNIZED,
286 					    (void *)cph,
287 					    ntohs(cph->sph_len));
288 					got_errchunk = B_TRUE;
289 				} else {
290 					/*
291 					 * Add an additional cause block to
292 					 * an existing ERROR chunk.
293 					 */
294 					sctp_add_unrec_parm(cph, errmp);
295 				}
296 			}
297 			if (ptype & SCTP_CONT_PROC_PARAMS) {
298 				/*
299 				 * Continue processing params after this
300 				 * parameter.
301 				 */
302 				break;
303 			}
304 
305 			/*
306 			 * Stop processing params, report any reportable
307 			 * unrecognized params found so far.
308 			 */
309 			goto done;
310 		}
311 
312 		cph = sctp_next_parm(cph, &remaining);
313 	}
314 done:
315 	/*
316 	 * Some sanity checks.  The following should not fail unless the
317 	 * other side is broken.
318 	 *
319 	 * 1. If this is a V4 endpoint but V4 address is not
320 	 * supported, abort.
321 	 * 2. If this is a V6 only endpoint but V6 address is
322 	 * not supported, abort.  This assumes that a V6
323 	 * endpoint can use both V4 and V6 addresses.
324 	 * We only care about supp_af when processing INIT, i.e want_cookie
325 	 * is NULL.
326 	 */
327 	if (want_cookie == NULL &&
328 	    ((sctp->sctp_family == AF_INET && !(*supp_af & PARM_SUPP_V4)) ||
329 	    (sctp->sctp_family == AF_INET6 && !(*supp_af & PARM_SUPP_V6) &&
330 	    sctp->sctp_connp->conn_ipv6_v6only))) {
331 		dprint(1, ("sctp:validate_init_params: supp addr\n"));
332 		serror = SCTP_ERR_BAD_ADDR;
333 		goto abort;
334 	}
335 
336 	if (want_cookie != NULL && !got_cookie) {
337 cookie_abort:
338 		dprint(1, ("validate_init_params: cookie absent\n"));
339 		sctp_send_abort(sctp, sctp_init2vtag(ch), SCTP_ERR_MISSING_PARM,
340 		    details, errlen, inmp, 0, B_FALSE);
341 		return (0);
342 	}
343 
344 	/* OK */
345 	return (1);
346 
347 abort:
348 	if (want_cookie != NULL)
349 		return (0);
350 
351 	sctp_send_abort(sctp, sctp_init2vtag(ch), serror, details,
352 	    errlen, inmp, 0, B_FALSE);
353 	return (0);
354 }
355 
356 /*
357  * Initialize params from the INIT and INIT-ACK when the assoc. is
358  * established.
359  */
360 boolean_t
361 sctp_initialize_params(sctp_t *sctp, sctp_init_chunk_t *init,
362     sctp_init_chunk_t *iack)
363 {
364 	/* Get initial TSN */
365 	sctp->sctp_ftsn = ntohl(init->sic_inittsn);
366 	sctp->sctp_lastacked = sctp->sctp_ftsn - 1;
367 
368 	/* Serial number is initialized to the same value as the TSN */
369 	sctp->sctp_fcsn = sctp->sctp_lastacked;
370 
371 	/*
372 	 * Get verification tags; no byteordering is necessary, since
373 	 * verfication tags are never processed except for byte-by-byte
374 	 * comparisons.
375 	 */
376 	sctp->sctp_fvtag = init->sic_inittag;
377 	sctp->sctp_sctph->sh_verf = init->sic_inittag;
378 	sctp->sctp_sctph6->sh_verf = init->sic_inittag;
379 	sctp->sctp_lvtag = iack->sic_inittag;
380 
381 	/* Get the peer's rwnd */
382 	sctp->sctp_frwnd = ntohl(init->sic_a_rwnd);
383 
384 	/* Allocate the in/out-stream counters */
385 	sctp->sctp_num_ostr = iack->sic_outstr;
386 	sctp->sctp_ostrcntrs = kmem_zalloc(sizeof (uint16_t) *
387 	    sctp->sctp_num_ostr, KM_NOSLEEP);
388 	if (sctp->sctp_ostrcntrs == NULL)
389 		return (B_FALSE);
390 
391 	sctp->sctp_num_istr = iack->sic_instr;
392 	sctp->sctp_instr = kmem_zalloc(sizeof (*sctp->sctp_instr) *
393 	    sctp->sctp_num_istr, KM_NOSLEEP);
394 	if (sctp->sctp_instr == NULL) {
395 		kmem_free(sctp->sctp_ostrcntrs, sizeof (uint16_t) *
396 		    sctp->sctp_num_ostr);
397 		sctp->sctp_ostrcntrs = NULL;
398 		return (B_FALSE);
399 	}
400 	return (B_TRUE);
401 }
402 
403 /*
404  * Copy the peer's original source address into addr. This relies on the
405  * following format (see sctp_send_initack() below):
406  * 	relative timestamp for the cookie (int64_t) +
407  * 	cookie lifetime (uint32_t) +
408  * 	local tie-tag (uint32_t) +  peer tie-tag (uint32_t) +
409  * 	Peer's original src ...
410  */
411 int
412 cl_sctp_cookie_paddr(sctp_chunk_hdr_t *ch, in6_addr_t *addr)
413 {
414 	uchar_t	*off;
415 
416 	ASSERT(addr != NULL);
417 
418 	if (ch->sch_id != CHUNK_COOKIE)
419 		return (EINVAL);
420 
421 	off = (uchar_t *)ch + sizeof (*ch) + sizeof (int64_t) +
422 	    sizeof (uint32_t) + sizeof (uint32_t) + sizeof (uint32_t);
423 
424 	bcopy(off, addr, sizeof (*addr));
425 
426 	return (0);
427 }
428 
429 #define	SCTP_CALC_COOKIE_LEN(initcp) \
430 	sizeof (int64_t) +		/* timestamp */			\
431 	sizeof (uint32_t) +		/* cookie lifetime */		\
432 	sizeof (sctp_init_chunk_t) +	/* INIT ACK */			\
433 	sizeof (in6_addr_t) +		/* peer's original source */ 	\
434 	ntohs((initcp)->sch_len) +	/* peer's INIT */		\
435 	sizeof (uint32_t) +		/* local tie-tag */		\
436 	sizeof (uint32_t) +		/* peer tie-tag */		\
437 	sizeof (sctp_parm_hdr_t) +	/* param header */		\
438 	16				/* MD5 hash */
439 
440 void
441 sctp_send_initack(sctp_t *sctp, sctp_hdr_t *initsh, sctp_chunk_hdr_t *ch,
442     mblk_t *initmp)
443 {
444 	ipha_t			*initiph;
445 	ip6_t			*initip6h;
446 	ipha_t			*iackiph;
447 	ip6_t			*iackip6h;
448 	sctp_chunk_hdr_t	*iack_ch;
449 	sctp_init_chunk_t	*iack;
450 	sctp_init_chunk_t	*init;
451 	sctp_hdr_t		*iacksh;
452 	size_t			cookielen;
453 	size_t			iacklen;
454 	size_t			ipsctplen;
455 	size_t			errlen = 0;
456 	sctp_parm_hdr_t		*cookieph;
457 	mblk_t			*iackmp;
458 	uint32_t		itag;
459 	uint32_t		itsn;
460 	int64_t			*now;
461 	int64_t			nowt;
462 	uint32_t		*lifetime;
463 	char			*p;
464 	boolean_t		 isv4;
465 	int			supp_af = 0;
466 	uint_t			sctp_options;
467 	uint32_t		*ttag;
468 	int			pad;
469 	mblk_t			*errmp = NULL;
470 	boolean_t		initcollision = B_FALSE;
471 	boolean_t		linklocal = B_FALSE;
472 	cred_t			*cr;
473 	ts_label_t		*initlabel;
474 	sctp_stack_t		*sctps = sctp->sctp_sctps;
475 
476 	BUMP_LOCAL(sctp->sctp_ibchunks);
477 	isv4 = (IPH_HDR_VERSION(initmp->b_rptr) == IPV4_VERSION);
478 
479 	/* Extract the INIT chunk */
480 	if (isv4) {
481 		initiph = (ipha_t *)initmp->b_rptr;
482 		ipsctplen = sctp->sctp_ip_hdr_len;
483 		supp_af |= PARM_SUPP_V4;
484 	} else {
485 		initip6h = (ip6_t *)initmp->b_rptr;
486 		ipsctplen = sctp->sctp_ip_hdr6_len;
487 		if (IN6_IS_ADDR_LINKLOCAL(&initip6h->ip6_src))
488 			linklocal = B_TRUE;
489 		supp_af |= PARM_SUPP_V6;
490 	}
491 	ASSERT(OK_32PTR(initsh));
492 	init = (sctp_init_chunk_t *)((char *)(initsh + 1) + sizeof (*iack_ch));
493 
494 	/* Make sure we like the peer's parameters */
495 	if (validate_init_params(sctp, ch, init, initmp, NULL, &errmp,
496 	    &supp_af, &sctp_options) == 0) {
497 		return;
498 	}
499 	if (errmp != NULL)
500 		errlen = msgdsize(errmp);
501 	if (sctp->sctp_family == AF_INET) {
502 		/*
503 		 * Irregardless of the supported address in the INIT, v4
504 		 * must be supported.
505 		 */
506 		supp_af = PARM_SUPP_V4;
507 	}
508 	if (sctp->sctp_state <= SCTPS_LISTEN) {
509 		/* normal, expected INIT: generate new vtag and itsn */
510 		(void) random_get_pseudo_bytes((uint8_t *)&itag, sizeof (itag));
511 		if (itag == 0)
512 			itag = (uint32_t)gethrtime();
513 		itsn = itag + 1;
514 		itag = htonl(itag);
515 	} else if (sctp->sctp_state == SCTPS_COOKIE_WAIT ||
516 	    sctp->sctp_state == SCTPS_COOKIE_ECHOED) {
517 		/* init collision; copy vtag and itsn from sctp */
518 		itag = sctp->sctp_lvtag;
519 		itsn = sctp->sctp_ltsn;
520 		/*
521 		 * In addition we need to send all the params that was sent
522 		 * in our INIT chunk. Essentially, it is only the supported
523 		 * address params that we need to add.
524 		 */
525 		initcollision = B_TRUE;
526 		/*
527 		 * When we sent the INIT, we should have set linklocal in
528 		 * the sctp which should be good enough.
529 		 */
530 		if (linklocal)
531 			linklocal = B_FALSE;
532 	} else {
533 		/* peer restart; generate new vtag but keep everything else */
534 		(void) random_get_pseudo_bytes((uint8_t *)&itag, sizeof (itag));
535 		if (itag == 0)
536 			itag = (uint32_t)gethrtime();
537 		itag = htonl(itag);
538 		itsn = sctp->sctp_ltsn;
539 	}
540 
541 	/*
542 	 * Allocate a mblk for the INIT ACK, consisting of the link layer
543 	 * header, the IP header, the SCTP common header, and INIT ACK chunk,
544 	 * and finally the COOKIE parameter.
545 	 */
546 	cookielen = SCTP_CALC_COOKIE_LEN(ch);
547 	iacklen = sizeof (*iack_ch) + sizeof (*iack) + cookielen;
548 	if (sctp->sctp_send_adaptation)
549 		iacklen += (sizeof (sctp_parm_hdr_t) + sizeof (uint32_t));
550 	if (((sctp_options & SCTP_PRSCTP_OPTION) || initcollision) &&
551 	    sctp->sctp_prsctp_aware && sctps->sctps_prsctp_enabled) {
552 		iacklen += sctp_options_param_len(sctp, SCTP_PRSCTP_OPTION);
553 	}
554 	if (initcollision)
555 		iacklen += sctp_supaddr_param_len(sctp);
556 	if (!linklocal)
557 		iacklen += sctp_addr_params(sctp, supp_af, NULL, B_FALSE);
558 	ipsctplen += sizeof (*iacksh) + iacklen;
559 	iacklen += errlen;
560 	if ((pad = ipsctplen % 4) != 0) {
561 		pad = 4 - pad;
562 		ipsctplen += pad;
563 	}
564 
565 	/*
566 	 * If the listen socket is bound to a trusted extensions
567 	 * multi-label port, attach a copy of the listener's cred
568 	 * to the new INITACK mblk. Modify the cred to contain
569 	 * the security label of the received INIT packet.
570 	 * If not a multi-label port, attach the unmodified
571 	 * listener's cred directly.
572 	 *
573 	 * We expect Sun developed kernel modules to properly set
574 	 * cred labels for sctp connections. We can't be so sure this
575 	 * will be done correctly when 3rd party kernel modules
576 	 * directly use sctp. The initlabel panic guard logic was
577 	 * added to cover this possibility.
578 	 */
579 	if (sctp->sctp_connp->conn_mlp_type != mlptSingle) {
580 		initlabel = MBLK_GETLABEL(initmp);
581 		if (initlabel == NULL) {
582 			sctp_send_abort(sctp, sctp_init2vtag(ch),
583 			    SCTP_ERR_UNKNOWN, NULL, 0, initmp, 0, B_FALSE);
584 			return;
585 		}
586 		cr = copycred_from_bslabel(CONN_CRED(sctp->sctp_connp),
587 		    &initlabel->tsl_label, initlabel->tsl_doi, KM_NOSLEEP);
588 		if (cr == NULL) {
589 			sctp_send_abort(sctp, sctp_init2vtag(ch),
590 			    SCTP_ERR_NO_RESOURCES, NULL, 0, initmp, 0, B_FALSE);
591 			return;
592 		}
593 		iackmp = allocb_cred(ipsctplen + sctps->sctps_wroff_xtra, cr);
594 		crfree(cr);
595 	} else {
596 		iackmp = allocb_cred(ipsctplen + sctps->sctps_wroff_xtra,
597 		    CONN_CRED(sctp->sctp_connp));
598 	}
599 	if (iackmp == NULL) {
600 		sctp_send_abort(sctp, sctp_init2vtag(ch),
601 		    SCTP_ERR_NO_RESOURCES, NULL, 0, initmp, 0, B_FALSE);
602 		return;
603 	}
604 
605 	/* Copy in the [imcomplete] IP/SCTP composite header */
606 	p = (char *)(iackmp->b_rptr + sctps->sctps_wroff_xtra);
607 	iackmp->b_rptr = (uchar_t *)p;
608 	if (isv4) {
609 		bcopy(sctp->sctp_iphc, p, sctp->sctp_hdr_len);
610 		iackiph = (ipha_t *)p;
611 
612 		/* Copy the peer's IP addr */
613 		iackiph->ipha_dst = initiph->ipha_src;
614 		iackiph->ipha_src = initiph->ipha_dst;
615 		iackiph->ipha_length = htons(ipsctplen + errlen);
616 		iacksh = (sctp_hdr_t *)(p + sctp->sctp_ip_hdr_len);
617 	} else {
618 		bcopy(sctp->sctp_iphc6, p, sctp->sctp_hdr6_len);
619 		iackip6h = (ip6_t *)p;
620 
621 		/* Copy the peer's IP addr */
622 		iackip6h->ip6_dst = initip6h->ip6_src;
623 		iackip6h->ip6_src = initip6h->ip6_dst;
624 		iackip6h->ip6_plen = htons(ipsctplen - sizeof (*iackip6h) +
625 		    errlen);
626 		iacksh = (sctp_hdr_t *)(p + sctp->sctp_ip_hdr6_len);
627 	}
628 	ASSERT(OK_32PTR(iacksh));
629 
630 	/* Fill in the holes in the SCTP common header */
631 	iacksh->sh_sport = initsh->sh_dport;
632 	iacksh->sh_dport = initsh->sh_sport;
633 	iacksh->sh_verf = init->sic_inittag;
634 
635 	/* INIT ACK chunk header */
636 	iack_ch = (sctp_chunk_hdr_t *)(iacksh + 1);
637 	iack_ch->sch_id = CHUNK_INIT_ACK;
638 	iack_ch->sch_flags = 0;
639 	iack_ch->sch_len = htons(iacklen);
640 
641 	/* The INIT ACK itself */
642 	iack = (sctp_init_chunk_t *)(iack_ch + 1);
643 	iack->sic_inittag = itag;	/* already in network byteorder */
644 	iack->sic_inittsn = htonl(itsn);
645 
646 	iack->sic_a_rwnd = htonl(sctp->sctp_rwnd);
647 	/* Advertise what we would want to have as stream #'s */
648 	iack->sic_outstr = htons(MIN(sctp->sctp_num_ostr,
649 	    ntohs(init->sic_instr)));
650 	iack->sic_instr = htons(sctp->sctp_num_istr);
651 
652 	p = (char *)(iack + 1);
653 	p += sctp_adaptation_code_param(sctp, (uchar_t *)p);
654 	if (initcollision)
655 		p += sctp_supaddr_param(sctp, (uchar_t *)p);
656 	if (!linklocal)
657 		p += sctp_addr_params(sctp, supp_af, (uchar_t *)p, B_FALSE);
658 	if (((sctp_options & SCTP_PRSCTP_OPTION) || initcollision) &&
659 	    sctp->sctp_prsctp_aware && sctps->sctps_prsctp_enabled) {
660 		p += sctp_options_param(sctp, p, SCTP_PRSCTP_OPTION);
661 	}
662 	/*
663 	 * Generate and lay in the COOKIE parameter.
664 	 *
665 	 * Any change here that results in a change of location for
666 	 * the peer's orig source address must be propagated to the fn
667 	 * cl_sctp_cookie_paddr() above.
668 	 *
669 	 * The cookie consists of:
670 	 * 1. The relative timestamp for the cookie (lbolt64)
671 	 * 2. The cookie lifetime (uint32_t) in tick
672 	 * 3. The local tie-tag
673 	 * 4. The peer tie-tag
674 	 * 5. Peer's original src, used to confirm the validity of address.
675 	 * 6. Our INIT ACK chunk, less any parameters
676 	 * 7. The INIT chunk (may contain parameters)
677 	 * 8. 128-bit MD5 signature.
678 	 *
679 	 * Since the timestamp values will only be evaluated locally, we
680 	 * don't need to worry about byte-ordering them.
681 	 */
682 	cookieph = (sctp_parm_hdr_t *)p;
683 	cookieph->sph_type = htons(PARM_COOKIE);
684 	cookieph->sph_len = htons(cookielen);
685 
686 	/* timestamp */
687 	now = (int64_t *)(cookieph + 1);
688 	nowt = lbolt64;
689 	bcopy(&nowt, now, sizeof (*now));
690 
691 	/* cookie lifetime -- need configuration */
692 	lifetime = (uint32_t *)(now + 1);
693 	*lifetime = sctp->sctp_cookie_lifetime;
694 
695 	/* Set the tie-tags */
696 	ttag = (uint32_t *)(lifetime + 1);
697 	if (sctp->sctp_state <= SCTPS_COOKIE_WAIT) {
698 		*ttag = 0;
699 		ttag++;
700 		*ttag = 0;
701 		ttag++;
702 	} else {
703 		/* local tie-tag (network byte-order) */
704 		*ttag = sctp->sctp_lvtag;
705 		ttag++;
706 		/* peer tie-tag (network byte-order) */
707 		*ttag = sctp->sctp_fvtag;
708 		ttag++;
709 	}
710 	/*
711 	 * Copy in peer's original source address so that we can confirm
712 	 * the reachability later.
713 	 */
714 	p = (char *)ttag;
715 	if (isv4) {
716 		in6_addr_t peer_addr;
717 
718 		IN6_IPADDR_TO_V4MAPPED(iackiph->ipha_dst, &peer_addr);
719 		bcopy(&peer_addr, p, sizeof (in6_addr_t));
720 	} else {
721 		bcopy(&iackip6h->ip6_dst, p, sizeof (in6_addr_t));
722 	}
723 	p += sizeof (in6_addr_t);
724 	/* Copy in our INIT ACK chunk */
725 	bcopy(iack, p, sizeof (*iack));
726 	iack = (sctp_init_chunk_t *)p;
727 	/* Set the # of streams we'll end up using */
728 	iack->sic_outstr = MIN(sctp->sctp_num_ostr, ntohs(init->sic_instr));
729 	iack->sic_instr = MIN(sctp->sctp_num_istr, ntohs(init->sic_outstr));
730 	p += sizeof (*iack);
731 
732 	/* Copy in the peer's INIT chunk */
733 	bcopy(ch, p, ntohs(ch->sch_len));
734 	p += ntohs(ch->sch_len);
735 
736 	/*
737 	 * Calculate the HMAC ICV into the digest slot in buf.
738 	 * First, generate a new secret if the current secret is
739 	 * older than the new secret lifetime parameter permits,
740 	 * copying the current secret to sctp_old_secret.
741 	 */
742 	if (sctps->sctps_new_secret_interval > 0 &&
743 	    (sctp->sctp_last_secret_update +
744 	    MSEC_TO_TICK(sctps->sctps_new_secret_interval)) <= nowt) {
745 		bcopy(sctp->sctp_secret, sctp->sctp_old_secret,
746 		    SCTP_SECRET_LEN);
747 		(void) random_get_pseudo_bytes(sctp->sctp_secret,
748 		    SCTP_SECRET_LEN);
749 		sctp->sctp_last_secret_update = nowt;
750 	}
751 
752 	hmac_md5((uchar_t *)now, cookielen - sizeof (*cookieph) - 16,
753 	    (uchar_t *)sctp->sctp_secret, SCTP_SECRET_LEN, (uchar_t *)p);
754 
755 	iackmp->b_wptr = iackmp->b_rptr + ipsctplen;
756 	iackmp->b_cont = errmp;		/*  OK if NULL */
757 
758 	if (is_system_labeled() && (cr = DB_CRED(iackmp)) != NULL &&
759 	    crgetlabel(cr) != NULL) {
760 		conn_t *connp = sctp->sctp_connp;
761 		int err;
762 
763 		if (isv4)
764 			err = tsol_check_label(cr, &iackmp,
765 			    connp->conn_mac_exempt,
766 			    sctps->sctps_netstack->netstack_ip);
767 		else
768 			err = tsol_check_label_v6(cr, &iackmp,
769 			    connp->conn_mac_exempt,
770 			    sctps->sctps_netstack->netstack_ip);
771 		if (err != 0) {
772 			sctp_send_abort(sctp, sctp_init2vtag(ch),
773 			    SCTP_ERR_AUTH_ERR, NULL, 0, initmp, 0, B_FALSE);
774 			freemsg(iackmp);
775 			return;
776 		}
777 	}
778 
779 	/*
780 	 * Stash the conn ptr info. for IP only as e don't have any
781 	 * cached IRE.
782 	 */
783 	SCTP_STASH_IPINFO(iackmp, (ire_t *)NULL);
784 
785 	/* XXX sctp == sctp_g_q, so using its obchunks is valid */
786 	BUMP_LOCAL(sctp->sctp_opkts);
787 	BUMP_LOCAL(sctp->sctp_obchunks);
788 
789 	/* OK to call IP_PUT() here instead of sctp_add_sendq(). */
790 	CONN_INC_REF(sctp->sctp_connp);
791 	iackmp->b_flag |= MSGHASREF;
792 	IP_PUT(iackmp, sctp->sctp_connp, isv4);
793 }
794 
795 void
796 sctp_send_cookie_ack(sctp_t *sctp)
797 {
798 	sctp_chunk_hdr_t *cach;
799 	mblk_t *camp;
800 	sctp_stack_t	*sctps = sctp->sctp_sctps;
801 
802 	camp = sctp_make_mp(sctp, NULL, sizeof (*cach));
803 	if (camp == NULL) {
804 		/* XXX should abort, but don't have the inmp anymore */
805 		SCTP_KSTAT(sctps, sctp_send_cookie_ack_failed);
806 		return;
807 	}
808 
809 	cach = (sctp_chunk_hdr_t *)camp->b_wptr;
810 	camp->b_wptr = (uchar_t *)(cach + 1);
811 	cach->sch_id = CHUNK_COOKIE_ACK;
812 	cach->sch_flags = 0;
813 	cach->sch_len = htons(sizeof (*cach));
814 
815 	sctp_set_iplen(sctp, camp);
816 
817 	BUMP_LOCAL(sctp->sctp_obchunks);
818 
819 	sctp_add_sendq(sctp, camp);
820 }
821 
822 static int
823 sctp_find_al_ind(sctp_parm_hdr_t *sph, ssize_t len, uint32_t *adaptation_code)
824 {
825 
826 	if (len < sizeof (*sph))
827 		return (-1);
828 	while (sph != NULL) {
829 		if (sph->sph_type == htons(PARM_ADAPT_LAYER_IND) &&
830 		    ntohs(sph->sph_len) >= (sizeof (*sph) +
831 		    sizeof (uint32_t))) {
832 			*adaptation_code = *(uint32_t *)(sph + 1);
833 			return (0);
834 		}
835 		sph = sctp_next_parm(sph, &len);
836 	}
837 	return (-1);
838 }
839 
840 void
841 sctp_send_cookie_echo(sctp_t *sctp, sctp_chunk_hdr_t *iackch, mblk_t *iackmp)
842 {
843 	mblk_t			*cemp;
844 	mblk_t			*mp = NULL;
845 	mblk_t			*head;
846 	mblk_t			*meta;
847 	sctp_faddr_t		*fp;
848 	sctp_chunk_hdr_t	*cech;
849 	sctp_init_chunk_t	 *iack;
850 	int32_t			cansend;
851 	int32_t			seglen;
852 	size_t			ceclen;
853 	sctp_parm_hdr_t		*cph;
854 	sctp_data_hdr_t		*sdc;
855 	sctp_tf_t		*tf;
856 	int			pad = 0;
857 	int			hdrlen;
858 	mblk_t			*errmp = NULL;
859 	uint_t			sctp_options;
860 	int			error;
861 	uint16_t		old_num_str;
862 	sctp_stack_t		*sctps = sctp->sctp_sctps;
863 
864 	iack = (sctp_init_chunk_t *)(iackch + 1);
865 
866 	cph = NULL;
867 	if (validate_init_params(sctp, iackch, iack, iackmp, &cph, &errmp,
868 	    &pad, &sctp_options) == 0) { /* result in 'pad' ignored */
869 		BUMP_MIB(&sctps->sctps_mib, sctpAborted);
870 		sctp_assoc_event(sctp, SCTP_CANT_STR_ASSOC, 0, NULL);
871 		sctp_clean_death(sctp, ECONNABORTED);
872 		return;
873 	}
874 	ASSERT(cph != NULL);
875 
876 	ASSERT(sctp->sctp_cookie_mp == NULL);
877 
878 	/* Got a cookie to echo back; allocate an mblk */
879 	ceclen = sizeof (*cech) + ntohs(cph->sph_len) - sizeof (*cph);
880 	if ((pad = ceclen & (SCTP_ALIGN - 1)) != 0)
881 		pad = SCTP_ALIGN - pad;
882 
883 	if (IPH_HDR_VERSION(iackmp->b_rptr) == IPV4_VERSION)
884 		hdrlen = sctp->sctp_hdr_len;
885 	else
886 		hdrlen = sctp->sctp_hdr6_len;
887 
888 	cemp = allocb(sctps->sctps_wroff_xtra + hdrlen + ceclen + pad,
889 	    BPRI_MED);
890 	if (cemp == NULL) {
891 		SCTP_FADDR_TIMER_RESTART(sctp, sctp->sctp_current,
892 		    sctp->sctp_current->rto);
893 		if (errmp != NULL)
894 			freeb(errmp);
895 		return;
896 	}
897 	cemp->b_rptr += (sctps->sctps_wroff_xtra + hdrlen);
898 
899 	/* Process the INIT ACK */
900 	sctp->sctp_sctph->sh_verf = iack->sic_inittag;
901 	sctp->sctp_sctph6->sh_verf = iack->sic_inittag;
902 	sctp->sctp_fvtag = iack->sic_inittag;
903 	sctp->sctp_ftsn = ntohl(iack->sic_inittsn);
904 	sctp->sctp_lastacked = sctp->sctp_ftsn - 1;
905 	sctp->sctp_fcsn = sctp->sctp_lastacked;
906 	sctp->sctp_frwnd = ntohl(iack->sic_a_rwnd);
907 
908 	/*
909 	 * Populate sctp with addresses given in the INIT ACK or IP header.
910 	 * Need to set the df bit in the current fp as it has been cleared
911 	 * in sctp_connect().
912 	 */
913 	sctp->sctp_current->df = B_TRUE;
914 	/*
915 	 * Since IP uses this info during the fanout process, we need to hold
916 	 * the lock for this hash line while performing this operation.
917 	 */
918 	/* XXX sctp_conn_fanout + SCTP_CONN_HASH(sctps, sctp->sctp_ports); */
919 	ASSERT(sctp->sctp_conn_tfp != NULL);
920 	tf = sctp->sctp_conn_tfp;
921 	/* sctp isn't a listener so only need to hold conn fanout lock */
922 	mutex_enter(&tf->tf_lock);
923 	if (sctp_get_addrparams(sctp, NULL, iackmp, iackch, NULL) != 0) {
924 		mutex_exit(&tf->tf_lock);
925 		freeb(cemp);
926 		SCTP_FADDR_TIMER_RESTART(sctp, sctp->sctp_current,
927 		    sctp->sctp_current->rto);
928 		if (errmp != NULL)
929 			freeb(errmp);
930 		return;
931 	}
932 	mutex_exit(&tf->tf_lock);
933 
934 	fp = sctp->sctp_current;
935 
936 	/*
937 	 * There could be a case when we get an INIT-ACK again, if the INIT
938 	 * is re-transmitted, for e.g., which means we would have already
939 	 * allocated this resource earlier (also for sctp_instr). In this
940 	 * case we check and re-allocate, if necessary.
941 	 */
942 	old_num_str = sctp->sctp_num_ostr;
943 	if (ntohs(iack->sic_instr) < sctp->sctp_num_ostr)
944 		sctp->sctp_num_ostr = ntohs(iack->sic_instr);
945 	if (sctp->sctp_ostrcntrs == NULL) {
946 		sctp->sctp_ostrcntrs = kmem_zalloc(sizeof (uint16_t) *
947 		    sctp->sctp_num_ostr, KM_NOSLEEP);
948 	} else {
949 		ASSERT(old_num_str > 0);
950 		if (old_num_str != sctp->sctp_num_ostr) {
951 			kmem_free(sctp->sctp_ostrcntrs, sizeof (uint16_t) *
952 			    old_num_str);
953 			sctp->sctp_ostrcntrs = kmem_zalloc(sizeof (uint16_t) *
954 			    sctp->sctp_num_ostr, KM_NOSLEEP);
955 		}
956 	}
957 	if (sctp->sctp_ostrcntrs == NULL) {
958 		freeb(cemp);
959 		SCTP_FADDR_TIMER_RESTART(sctp, fp, fp->rto);
960 		if (errmp != NULL)
961 			freeb(errmp);
962 		return;
963 	}
964 
965 	/*
966 	 * Allocate the in stream tracking array. Comments for sctp_ostrcntrs
967 	 * hold here too.
968 	 */
969 	old_num_str = sctp->sctp_num_istr;
970 	if (ntohs(iack->sic_outstr) < sctp->sctp_num_istr)
971 		sctp->sctp_num_istr = ntohs(iack->sic_outstr);
972 	if (sctp->sctp_instr == NULL) {
973 		sctp->sctp_instr = kmem_zalloc(sizeof (*sctp->sctp_instr) *
974 		    sctp->sctp_num_istr, KM_NOSLEEP);
975 	} else {
976 		ASSERT(old_num_str > 0);
977 		if (old_num_str != sctp->sctp_num_istr) {
978 			kmem_free(sctp->sctp_instr,
979 			    sizeof (*sctp->sctp_instr) * old_num_str);
980 			sctp->sctp_instr = kmem_zalloc(
981 			    sizeof (*sctp->sctp_instr) * sctp->sctp_num_istr,
982 			    KM_NOSLEEP);
983 		}
984 	}
985 	if (sctp->sctp_instr == NULL) {
986 		kmem_free(sctp->sctp_ostrcntrs,
987 		    sizeof (uint16_t) * sctp->sctp_num_ostr);
988 		freeb(cemp);
989 		SCTP_FADDR_TIMER_RESTART(sctp, fp, fp->rto);
990 		if (errmp != NULL)
991 			freeb(errmp);
992 		return;
993 	}
994 
995 	if (!(sctp_options & SCTP_PRSCTP_OPTION) && sctp->sctp_prsctp_aware)
996 		sctp->sctp_prsctp_aware = B_FALSE;
997 
998 	if (sctp_find_al_ind((sctp_parm_hdr_t *)(iack + 1),
999 	    ntohs(iackch->sch_len) - (sizeof (*iackch) + sizeof (*iack)),
1000 	    &sctp->sctp_rx_adaptation_code) == 0) {
1001 		sctp->sctp_recv_adaptation = 1;
1002 	}
1003 
1004 	cech = (sctp_chunk_hdr_t *)cemp->b_rptr;
1005 	ASSERT(OK_32PTR(cech));
1006 	cech->sch_id = CHUNK_COOKIE;
1007 	cech->sch_flags = 0;
1008 	cech->sch_len = htons(ceclen);
1009 
1010 	/* Copy the cookie (less the parm hdr) to the chunk */
1011 	bcopy(cph + 1, cech + 1, ceclen - sizeof (*cph));
1012 
1013 	cemp->b_wptr = cemp->b_rptr + ceclen;
1014 
1015 	if (sctp->sctp_unsent > 0) {
1016 		sctp_msg_hdr_t	*smh;
1017 		mblk_t		*prev = NULL;
1018 		uint32_t	unsent = 0;
1019 
1020 		mp = sctp->sctp_xmit_unsent;
1021 		do {
1022 			smh = (sctp_msg_hdr_t *)mp->b_rptr;
1023 			if (smh->smh_sid >= sctp->sctp_num_ostr) {
1024 				unsent += smh->smh_msglen;
1025 				if (prev != NULL)
1026 					prev->b_next = mp->b_next;
1027 				else
1028 					sctp->sctp_xmit_unsent = mp->b_next;
1029 				mp->b_next = NULL;
1030 				sctp_sendfail_event(sctp, mp, SCTP_ERR_BAD_SID,
1031 				    B_FALSE);
1032 				if (prev != NULL)
1033 					mp = prev->b_next;
1034 				else
1035 					mp = sctp->sctp_xmit_unsent;
1036 			} else {
1037 				prev = mp;
1038 				mp = mp->b_next;
1039 			}
1040 		} while (mp != NULL);
1041 		if (unsent > 0) {
1042 			ASSERT(sctp->sctp_unsent >= unsent);
1043 			sctp->sctp_unsent -= unsent;
1044 			/*
1045 			 * Update ULP the amount of queued data, which is
1046 			 * sent-unack'ed + unsent.
1047 			 * This is not necessary, but doesn't harm, we
1048 			 * just use unsent instead of sent-unack'ed +
1049 			 * unsent, since there won't be any sent-unack'ed
1050 			 * here.
1051 			 */
1052 			if (!SCTP_IS_DETACHED(sctp))
1053 				SCTP_TXQ_UPDATE(sctp);
1054 		}
1055 		if (sctp->sctp_xmit_unsent == NULL)
1056 			sctp->sctp_xmit_unsent_tail = NULL;
1057 	}
1058 	ceclen += pad;
1059 	cansend = MIN(sctp->sctp_unsent, sctp->sctp_frwnd);
1060 	meta = sctp_get_msg_to_send(sctp, &mp, NULL, &error, ceclen,
1061 	    cansend,  NULL);
1062 	/*
1063 	 * The error cannot be anything else since we could have an non-zero
1064 	 * error only if sctp_get_msg_to_send() tries to send a Forward
1065 	 * TSN which will not happen here.
1066 	 */
1067 	ASSERT(error == 0);
1068 	if (meta == NULL)
1069 		goto sendcookie;
1070 	sctp->sctp_xmit_tail = meta;
1071 	sdc = (sctp_data_hdr_t *)mp->b_rptr;
1072 	seglen = ntohs(sdc->sdh_len);
1073 	if ((ceclen + seglen) > fp->sfa_pmss ||
1074 	    (seglen - sizeof (*sdc)) > cansend) {
1075 		goto sendcookie;
1076 	}
1077 	/* OK, if this fails */
1078 	cemp->b_cont = dupmsg(mp);
1079 sendcookie:
1080 	head = sctp_add_proto_hdr(sctp, fp, cemp, 0, NULL);
1081 	if (head == NULL) {
1082 		freemsg(cemp);
1083 		SCTP_FADDR_TIMER_RESTART(sctp, fp, fp->rto);
1084 		if (errmp != NULL)
1085 			freeb(errmp);
1086 		SCTP_KSTAT(sctps, sctp_send_cookie_failed);
1087 		return;
1088 	}
1089 	/*
1090 	 * Even if cookie-echo exceeds MTU for one of the hops, it'll
1091 	 * have a chance of getting there.
1092 	 */
1093 	if (fp->isv4) {
1094 		ipha_t *iph = (ipha_t *)head->b_rptr;
1095 		iph->ipha_fragment_offset_and_flags = 0;
1096 	}
1097 	BUMP_LOCAL(sctp->sctp_obchunks);
1098 
1099 	sctp->sctp_cookie_mp = dupmsg(head);
1100 	/* Don't bundle, we will just resend init if this cookie is lost. */
1101 	if (sctp->sctp_cookie_mp == NULL) {
1102 		if (cemp->b_cont != NULL) {
1103 			freemsg(cemp->b_cont);
1104 			cemp->b_cont = NULL;
1105 		}
1106 	} else if (cemp->b_cont != NULL) {
1107 		ASSERT(mp != NULL && mp == meta->b_cont);
1108 		SCTP_CHUNK_CLEAR_FLAGS(cemp->b_cont);
1109 		cemp->b_wptr += pad;
1110 		seglen -= sizeof (*sdc);
1111 		SCTP_CHUNK_SENT(sctp, mp, sdc, fp, seglen, meta);
1112 	}
1113 	if (errmp != NULL) {
1114 		if (cemp->b_cont == NULL)
1115 			cemp->b_wptr += pad;
1116 		linkb(head, errmp);
1117 	}
1118 	sctp->sctp_state = SCTPS_COOKIE_ECHOED;
1119 	SCTP_FADDR_TIMER_RESTART(sctp, fp, fp->rto);
1120 
1121 	sctp_set_iplen(sctp, head);
1122 	sctp_add_sendq(sctp, head);
1123 }
1124 
1125 int
1126 sctp_process_cookie(sctp_t *sctp, sctp_chunk_hdr_t *ch, mblk_t *cmp,
1127     sctp_init_chunk_t **iackpp, sctp_hdr_t *insctph, int *recv_adaptation,
1128     in6_addr_t *peer_addr)
1129 {
1130 	int32_t			clen;
1131 	size_t			initplen;
1132 	uchar_t			*p;
1133 	uchar_t			*given_hash;
1134 	uchar_t			needed_hash[16];
1135 	int64_t			ts;
1136 	int64_t			diff;
1137 	uint32_t		*lt;
1138 	sctp_init_chunk_t	*iack;
1139 	sctp_chunk_hdr_t	*initch;
1140 	sctp_init_chunk_t	*init;
1141 	uint32_t		*lttag;
1142 	uint32_t		*fttag;
1143 	uint32_t		ports;
1144 	sctp_stack_t		*sctps = sctp->sctp_sctps;
1145 
1146 	BUMP_LOCAL(sctp->sctp_ibchunks);
1147 	/* Verify the ICV */
1148 	clen = ntohs(ch->sch_len) - sizeof (*ch) - 16;
1149 	if (clen < 0) {
1150 		dprint(1, ("invalid cookie chunk length %d\n",
1151 		    ntohs(ch->sch_len)));
1152 
1153 		return (-1);
1154 	}
1155 	p = (uchar_t *)(ch + 1);
1156 
1157 	hmac_md5(p, clen, (uchar_t *)sctp->sctp_secret, SCTP_SECRET_LEN,
1158 	    needed_hash);
1159 
1160 	/* The given hash follows the cookie data */
1161 	given_hash = p + clen;
1162 
1163 	if (bcmp(given_hash, needed_hash, 16) != 0) {
1164 		/* The secret may have changed; try the old secret */
1165 		hmac_md5(p, clen, (uchar_t *)sctp->sctp_old_secret,
1166 		    SCTP_SECRET_LEN, needed_hash);
1167 		if (bcmp(given_hash, needed_hash, 16) != 0) {
1168 			return (-1);
1169 		}
1170 	}
1171 
1172 	/* Timestamp is int64_t, and we only guarantee 32-bit alignment */
1173 	bcopy(p, &ts, sizeof (ts));
1174 	/* Cookie life time, uint32_t */
1175 	lt = (uint32_t *)(p + sizeof (ts));
1176 
1177 	/*
1178 	 * To quote PRC, "this is our baby", so let's continue.
1179 	 * We need to pull out the encapsulated INIT ACK and
1180 	 * INIT chunks. Note that we don't process these until
1181 	 * we have verified the timestamp, but we need them before
1182 	 * processing the timestamp since if the time check fails,
1183 	 * we need to get the verification tag from the INIT in order
1184 	 * to send a stale cookie error.
1185 	 */
1186 	lttag = (uint32_t *)(lt + 1);
1187 	fttag = lttag + 1;
1188 	if (peer_addr != NULL)
1189 		bcopy(fttag + 1, peer_addr, sizeof (in6_addr_t));
1190 	iack = (sctp_init_chunk_t *)((char *)(fttag + 1) + sizeof (in6_addr_t));
1191 	initch = (sctp_chunk_hdr_t *)(iack + 1);
1192 	init = (sctp_init_chunk_t *)(initch + 1);
1193 	initplen = ntohs(initch->sch_len) - (sizeof (*init) + sizeof (*initch));
1194 	*iackpp = iack;
1195 	*recv_adaptation = 0;
1196 
1197 	/*
1198 	 * Check the staleness of the Cookie, specified in 3.3.10.3 of
1199 	 * RFC 2960.
1200 	 *
1201 	 * The mesaure of staleness is the difference, in microseconds,
1202 	 * between the current time and the time the State Cookie expires.
1203 	 * So it is lbolt64 - (ts + *lt).  If it is positive, it means
1204 	 * that the Cookie has expired.
1205 	 */
1206 	diff = lbolt64 - (ts + *lt);
1207 	if (diff > 0 && (init->sic_inittag != sctp->sctp_fvtag ||
1208 	    iack->sic_inittag != sctp->sctp_lvtag)) {
1209 		uint32_t staleness;
1210 
1211 		staleness = TICK_TO_USEC(diff);
1212 		staleness = htonl(staleness);
1213 		sctp_send_abort(sctp, init->sic_inittag, SCTP_ERR_STALE_COOKIE,
1214 		    (char *)&staleness, sizeof (staleness), cmp, 1, B_FALSE);
1215 
1216 		dprint(1, ("stale cookie %d\n", staleness));
1217 
1218 		return (-1);
1219 	}
1220 
1221 	/* Check for attack by adding addresses to a restart */
1222 	bcopy(insctph, &ports, sizeof (ports));
1223 	if (sctp_secure_restart_check(cmp, initch, ports, KM_NOSLEEP,
1224 	    sctps) != 1) {
1225 		return (-1);
1226 	}
1227 
1228 	/* Look for adaptation code if there any parms in the INIT chunk */
1229 	if ((initplen >= sizeof (sctp_parm_hdr_t)) &&
1230 	    (sctp_find_al_ind((sctp_parm_hdr_t *)(init + 1), initplen,
1231 	    &sctp->sctp_rx_adaptation_code) == 0)) {
1232 		*recv_adaptation = 1;
1233 	}
1234 
1235 	/* Examine tie-tags */
1236 
1237 	if (sctp->sctp_state >= SCTPS_COOKIE_WAIT) {
1238 		if (sctp->sctp_state == SCTPS_ESTABLISHED &&
1239 		    init->sic_inittag == sctp->sctp_fvtag &&
1240 		    iack->sic_inittag == sctp->sctp_lvtag &&
1241 		    *fttag == 0 && *lttag == 0) {
1242 
1243 			dprint(1, ("duplicate cookie from %x:%x:%x:%x (%d)\n",
1244 			    SCTP_PRINTADDR(sctp->sctp_current->faddr),
1245 			    (int)(sctp->sctp_fport)));
1246 			return (-1);
1247 		}
1248 
1249 		if (init->sic_inittag != sctp->sctp_fvtag &&
1250 		    iack->sic_inittag != sctp->sctp_lvtag &&
1251 		    *fttag == sctp->sctp_fvtag &&
1252 		    *lttag == sctp->sctp_lvtag) {
1253 			int i;
1254 
1255 			/* Section 5.2.4 case A: restart */
1256 			sctp->sctp_fvtag = init->sic_inittag;
1257 			sctp->sctp_lvtag = iack->sic_inittag;
1258 
1259 			sctp->sctp_sctph->sh_verf = init->sic_inittag;
1260 			sctp->sctp_sctph6->sh_verf = init->sic_inittag;
1261 
1262 			sctp->sctp_ftsn = ntohl(init->sic_inittsn);
1263 			sctp->sctp_lastacked = sctp->sctp_ftsn - 1;
1264 			sctp->sctp_frwnd = ntohl(init->sic_a_rwnd);
1265 			sctp->sctp_fcsn = sctp->sctp_lastacked;
1266 
1267 			if (sctp->sctp_state < SCTPS_ESTABLISHED) {
1268 				sctp->sctp_state = SCTPS_ESTABLISHED;
1269 				sctp->sctp_assoc_start_time = (uint32_t)lbolt;
1270 			}
1271 
1272 			dprint(1, ("sctp peer %x:%x:%x:%x (%d) restarted\n",
1273 			    SCTP_PRINTADDR(sctp->sctp_current->faddr),
1274 			    (int)(sctp->sctp_fport)));
1275 			/* reset parameters */
1276 			sctp_congest_reset(sctp);
1277 
1278 			/* reset stream bookkeeping */
1279 			sctp_instream_cleanup(sctp, B_FALSE);
1280 
1281 			sctp->sctp_istr_nmsgs = 0;
1282 			sctp->sctp_rxqueued = 0;
1283 			for (i = 0; i < sctp->sctp_num_ostr; i++) {
1284 				sctp->sctp_ostrcntrs[i] = 0;
1285 			}
1286 			/* XXX flush xmit_list? */
1287 
1288 			return (0);
1289 		} else if (init->sic_inittag != sctp->sctp_fvtag &&
1290 		    iack->sic_inittag == sctp->sctp_lvtag) {
1291 
1292 			/* Section 5.2.4 case B: INIT collision */
1293 			if (sctp->sctp_state < SCTPS_ESTABLISHED) {
1294 				if (!sctp_initialize_params(sctp, init, iack))
1295 					return (-1);	/* Drop? */
1296 				sctp->sctp_state = SCTPS_ESTABLISHED;
1297 				sctp->sctp_assoc_start_time = (uint32_t)lbolt;
1298 			}
1299 
1300 			dprint(1, ("init collision with %x:%x:%x:%x (%d)\n",
1301 			    SCTP_PRINTADDR(sctp->sctp_current->faddr),
1302 			    (int)(sctp->sctp_fport)));
1303 
1304 			return (0);
1305 		} else if (iack->sic_inittag != sctp->sctp_lvtag &&
1306 		    init->sic_inittag == sctp->sctp_fvtag &&
1307 		    *fttag == 0 && *lttag == 0) {
1308 
1309 			/* Section 5.2.4 case C: late COOKIE */
1310 			dprint(1, ("late cookie from %x:%x:%x:%x (%d)\n",
1311 			    SCTP_PRINTADDR(sctp->sctp_current->faddr),
1312 			    (int)(sctp->sctp_fport)));
1313 			return (-1);
1314 		} else if (init->sic_inittag == sctp->sctp_fvtag &&
1315 		    iack->sic_inittag == sctp->sctp_lvtag) {
1316 
1317 			/*
1318 			 * Section 5.2.4 case D: COOKIE ECHO retransmit
1319 			 * Don't check cookie lifetime
1320 			 */
1321 			dprint(1, ("cookie tags match from %x:%x:%x:%x (%d)\n",
1322 			    SCTP_PRINTADDR(sctp->sctp_current->faddr),
1323 			    (int)(sctp->sctp_fport)));
1324 			if (sctp->sctp_state < SCTPS_ESTABLISHED) {
1325 				if (!sctp_initialize_params(sctp, init, iack))
1326 					return (-1);	/* Drop? */
1327 				sctp->sctp_state = SCTPS_ESTABLISHED;
1328 				sctp->sctp_assoc_start_time = (uint32_t)lbolt;
1329 			}
1330 			return (0);
1331 		} else {
1332 			/* unrecognized case -- silently drop it */
1333 			return (-1);
1334 		}
1335 	}
1336 
1337 	return (0);
1338 }
1339 
1340 /*
1341  * Similar to ip_fanout_sctp, except that the src addr(s) are drawn
1342  * from address parameters in an INIT ACK's address list. This
1343  * function is used when an INIT ACK is received but IP's fanout
1344  * function could not find a sctp via the normal lookup routine.
1345  * This can happen when a host sends an INIT ACK from a different
1346  * address than the INIT was sent to.
1347  *
1348  * Returns the sctp_t if found, or NULL if not found.
1349  */
1350 sctp_t *
1351 sctp_addrlist2sctp(mblk_t *mp, sctp_hdr_t *sctph, sctp_chunk_hdr_t *ich,
1352     zoneid_t zoneid, sctp_stack_t *sctps)
1353 {
1354 	int isv4;
1355 	ipha_t *iph;
1356 	ip6_t *ip6h;
1357 	in6_addr_t dst;
1358 	in6_addr_t src;
1359 	sctp_parm_hdr_t *ph;
1360 	ssize_t remaining;
1361 	sctp_init_chunk_t *iack;
1362 	uint32_t ports;
1363 	sctp_t *sctp = NULL;
1364 
1365 	ASSERT(ich->sch_id == CHUNK_INIT_ACK);
1366 
1367 	isv4 = (IPH_HDR_VERSION(mp->b_rptr) == IPV4_VERSION);
1368 	if (isv4) {
1369 		iph = (ipha_t *)mp->b_rptr;
1370 		IN6_IPADDR_TO_V4MAPPED(iph->ipha_dst, &dst);
1371 	} else {
1372 		ip6h = (ip6_t *)mp->b_rptr;
1373 		dst = ip6h->ip6_dst;
1374 	}
1375 
1376 	ports = *(uint32_t *)sctph;
1377 
1378 	dprint(1, ("sctp_addrlist2sctp: ports=%u, dst = %x:%x:%x:%x\n",
1379 	    ports, SCTP_PRINTADDR(dst)));
1380 
1381 	/* pull out any address parameters */
1382 	remaining = ntohs(ich->sch_len) - sizeof (*ich) - sizeof (*iack);
1383 	if (remaining < sizeof (*ph)) {
1384 		return (NULL);
1385 	}
1386 
1387 	iack = (sctp_init_chunk_t *)(ich + 1);
1388 	ph = (sctp_parm_hdr_t *)(iack + 1);
1389 
1390 	while (ph != NULL) {
1391 		/*
1392 		 * params have been put in host byteorder by
1393 		 * sctp_check_input()
1394 		 */
1395 		if (ph->sph_type == PARM_ADDR4) {
1396 			IN6_INADDR_TO_V4MAPPED((struct in_addr *)(ph + 1),
1397 			    &src);
1398 
1399 			sctp = sctp_conn_match(&src, &dst, ports, zoneid,
1400 			    sctps);
1401 
1402 			dprint(1,
1403 			    ("sctp_addrlist2sctp: src=%x:%x:%x:%x, sctp=%p\n",
1404 			    SCTP_PRINTADDR(src), (void *)sctp));
1405 
1406 
1407 			if (sctp != NULL) {
1408 				return (sctp);
1409 			}
1410 		} else if (ph->sph_type == PARM_ADDR6) {
1411 			src = *(in6_addr_t *)(ph + 1);
1412 			sctp = sctp_conn_match(&src, &dst, ports, zoneid,
1413 			    sctps);
1414 
1415 			dprint(1,
1416 			    ("sctp_addrlist2sctp: src=%x:%x:%x:%x, sctp=%p\n",
1417 			    SCTP_PRINTADDR(src), (void *)sctp));
1418 
1419 			if (sctp != NULL) {
1420 				return (sctp);
1421 			}
1422 		}
1423 
1424 		ph = sctp_next_parm(ph, &remaining);
1425 	}
1426 
1427 	return (NULL);
1428 }
1429