17c478bd9Sstevel@tonic-gate /*
27c478bd9Sstevel@tonic-gate  * CDDL HEADER START
37c478bd9Sstevel@tonic-gate  *
47c478bd9Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
577c67f2fSkcpoon  * Common Development and Distribution License (the "License").
677c67f2fSkcpoon  * You may not use this file except in compliance with the License.
77c478bd9Sstevel@tonic-gate  *
87c478bd9Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
97c478bd9Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
107c478bd9Sstevel@tonic-gate  * See the License for the specific language governing permissions
117c478bd9Sstevel@tonic-gate  * and limitations under the License.
127c478bd9Sstevel@tonic-gate  *
137c478bd9Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
147c478bd9Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
157c478bd9Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
167c478bd9Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
177c478bd9Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
187c478bd9Sstevel@tonic-gate  *
197c478bd9Sstevel@tonic-gate  * CDDL HEADER END
207c478bd9Sstevel@tonic-gate  */
2177c67f2fSkcpoon 
227c478bd9Sstevel@tonic-gate /*
23481845d8SGeorge Shepherd  * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
247c478bd9Sstevel@tonic-gate  */
257c478bd9Sstevel@tonic-gate 
267c478bd9Sstevel@tonic-gate #include <sys/types.h>
277c478bd9Sstevel@tonic-gate #include <sys/systm.h>
287c478bd9Sstevel@tonic-gate #include <sys/stream.h>
297c478bd9Sstevel@tonic-gate #include <sys/ddi.h>
307c478bd9Sstevel@tonic-gate #include <sys/sunddi.h>
317c478bd9Sstevel@tonic-gate #include <sys/strsubr.h>
327c478bd9Sstevel@tonic-gate #include <sys/strsun.h>
337c478bd9Sstevel@tonic-gate 
347c478bd9Sstevel@tonic-gate #include <netinet/in.h>
357c478bd9Sstevel@tonic-gate #include <netinet/ip6.h>
367c478bd9Sstevel@tonic-gate 
37bd670b35SErik Nordmark #include <inet/ipsec_impl.h>
387c478bd9Sstevel@tonic-gate #include <inet/common.h>
397c478bd9Sstevel@tonic-gate #include <inet/ip.h>
407c478bd9Sstevel@tonic-gate #include <inet/ip6.h>
417c478bd9Sstevel@tonic-gate #include <inet/mib2.h>
427c478bd9Sstevel@tonic-gate #include <inet/nd.h>
437c478bd9Sstevel@tonic-gate #include <inet/optcom.h>
447c478bd9Sstevel@tonic-gate #include <inet/sctp_ip.h>
45f4b3ec61Sdh #include <inet/ipclassifier.h>
467c478bd9Sstevel@tonic-gate #include "sctp_impl.h"
477c478bd9Sstevel@tonic-gate 
487c478bd9Sstevel@tonic-gate void
sctp_send_shutdown(sctp_t * sctp,int rexmit)497c478bd9Sstevel@tonic-gate sctp_send_shutdown(sctp_t *sctp, int rexmit)
507c478bd9Sstevel@tonic-gate {
517c478bd9Sstevel@tonic-gate 	mblk_t *smp;
527c478bd9Sstevel@tonic-gate 	mblk_t *sendmp;
537c478bd9Sstevel@tonic-gate 	sctp_chunk_hdr_t *sch;
547c478bd9Sstevel@tonic-gate 	uint32_t *ctsn;
557c478bd9Sstevel@tonic-gate 	sctp_faddr_t *fp;
56f4b3ec61Sdh 	sctp_stack_t	*sctps = sctp->sctp_sctps;
577c478bd9Sstevel@tonic-gate 
587c478bd9Sstevel@tonic-gate 	if (sctp->sctp_state != SCTPS_ESTABLISHED &&
597c478bd9Sstevel@tonic-gate 	    sctp->sctp_state != SCTPS_SHUTDOWN_PENDING &&
607c478bd9Sstevel@tonic-gate 	    sctp->sctp_state != SCTPS_SHUTDOWN_SENT) {
617c478bd9Sstevel@tonic-gate 		return;
627c478bd9Sstevel@tonic-gate 	}
637c478bd9Sstevel@tonic-gate 
647c478bd9Sstevel@tonic-gate 	if (sctp->sctp_state == SCTPS_ESTABLISHED) {
657c478bd9Sstevel@tonic-gate 		sctp->sctp_state = SCTPS_SHUTDOWN_PENDING;
667c478bd9Sstevel@tonic-gate 		/*
677c478bd9Sstevel@tonic-gate 		 * We set an upper bound on how long we will
687c478bd9Sstevel@tonic-gate 		 * wait for a shutdown-ack from the peer. This
697c478bd9Sstevel@tonic-gate 		 * is to prevent the receiver from attempting
707c478bd9Sstevel@tonic-gate 		 * to create a half-closed state indefinately.
717c478bd9Sstevel@tonic-gate 		 * See archive from IETF TSVWG mailing list
727c478bd9Sstevel@tonic-gate 		 * for June 2001 for more information.
737c478bd9Sstevel@tonic-gate 		 * Since we will not be calculating RTTs after
747c478bd9Sstevel@tonic-gate 		 * sending the shutdown, we can overload out_time
757c478bd9Sstevel@tonic-gate 		 * to track how long we have waited.
767c478bd9Sstevel@tonic-gate 		 */
77d3d50737SRafael Vanoni 		sctp->sctp_out_time = ddi_get_lbolt64();
787c478bd9Sstevel@tonic-gate 	}
797c478bd9Sstevel@tonic-gate 
807c478bd9Sstevel@tonic-gate 	/*
817c478bd9Sstevel@tonic-gate 	 * If there is unsent (or unacked) data, wait for it to get ack'd
827c478bd9Sstevel@tonic-gate 	 */
837c478bd9Sstevel@tonic-gate 	if (sctp->sctp_xmit_head != NULL || sctp->sctp_xmit_unsent != NULL) {
847c478bd9Sstevel@tonic-gate 		return;
857c478bd9Sstevel@tonic-gate 	}
867c478bd9Sstevel@tonic-gate 
877c478bd9Sstevel@tonic-gate 	/* rotate faddrs if we are retransmitting */
887c478bd9Sstevel@tonic-gate 	if (!rexmit) {
897c478bd9Sstevel@tonic-gate 		fp = sctp->sctp_current;
907c478bd9Sstevel@tonic-gate 	} else {
917c478bd9Sstevel@tonic-gate 		fp = sctp_rotate_faddr(sctp, sctp->sctp_shutdown_faddr);
927c478bd9Sstevel@tonic-gate 	}
937c478bd9Sstevel@tonic-gate 
947c478bd9Sstevel@tonic-gate 	sctp->sctp_shutdown_faddr = fp;
957c478bd9Sstevel@tonic-gate 
967c478bd9Sstevel@tonic-gate 	/* Link in a SACK if resending the shutdown */
977c478bd9Sstevel@tonic-gate 	if (sctp->sctp_state > SCTPS_SHUTDOWN_PENDING &&
987c478bd9Sstevel@tonic-gate 	    (sendmp = sctp_make_sack(sctp, fp, NULL)) != NULL) {
997c478bd9Sstevel@tonic-gate 
1007c478bd9Sstevel@tonic-gate 		smp = allocb(sizeof (*sch) + sizeof (*ctsn), BPRI_MED);
1017c478bd9Sstevel@tonic-gate 		if (smp == NULL) {
1027c478bd9Sstevel@tonic-gate 			freemsg(sendmp);
1037c478bd9Sstevel@tonic-gate 			goto done;
1047c478bd9Sstevel@tonic-gate 		}
1057c478bd9Sstevel@tonic-gate 		linkb(sendmp, smp);
1067c478bd9Sstevel@tonic-gate 
1077c478bd9Sstevel@tonic-gate 		sch = (sctp_chunk_hdr_t *)smp->b_rptr;
1087c478bd9Sstevel@tonic-gate 		smp->b_wptr = smp->b_rptr + sizeof (*sch) + sizeof (*ctsn);
1097c478bd9Sstevel@tonic-gate 	} else {
1107c478bd9Sstevel@tonic-gate 		sendmp = sctp_make_mp(sctp, fp,
1117c478bd9Sstevel@tonic-gate 		    sizeof (*sch) + sizeof (*ctsn));
1127c478bd9Sstevel@tonic-gate 		if (sendmp == NULL) {
113f4b3ec61Sdh 			SCTP_KSTAT(sctps, sctp_send_shutdown_failed);
1147c478bd9Sstevel@tonic-gate 			goto done;
1157c478bd9Sstevel@tonic-gate 		}
1167c478bd9Sstevel@tonic-gate 		sch = (sctp_chunk_hdr_t *)sendmp->b_wptr;
1177c478bd9Sstevel@tonic-gate 		sendmp->b_wptr += sizeof (*sch) + sizeof (*ctsn);
1187c478bd9Sstevel@tonic-gate 
1197c478bd9Sstevel@tonic-gate 		/* shutdown w/o sack, update lastacked */
1207c478bd9Sstevel@tonic-gate 		sctp->sctp_lastacked = sctp->sctp_ftsn - 1;
1217c478bd9Sstevel@tonic-gate 	}
1227c478bd9Sstevel@tonic-gate 
1237c478bd9Sstevel@tonic-gate 	sch->sch_id = CHUNK_SHUTDOWN;
1247c478bd9Sstevel@tonic-gate 	sch->sch_flags = 0;
1257c478bd9Sstevel@tonic-gate 	sch->sch_len = htons(sizeof (*sch) + sizeof (*ctsn));
1267c478bd9Sstevel@tonic-gate 
1277c478bd9Sstevel@tonic-gate 	ctsn = (uint32_t *)(sch + 1);
1287c478bd9Sstevel@tonic-gate 	*ctsn = htonl(sctp->sctp_lastacked);
1297c478bd9Sstevel@tonic-gate 
1307c478bd9Sstevel@tonic-gate 	/* Link the shutdown chunk in after the IP/SCTP header */
1317c478bd9Sstevel@tonic-gate 
1327c478bd9Sstevel@tonic-gate 	BUMP_LOCAL(sctp->sctp_obchunks);
1337c478bd9Sstevel@tonic-gate 
1347c478bd9Sstevel@tonic-gate 	/* Send the shutdown and restart the timer */
135*6be61d4eSchandrasekar marimuthu - Sun Microsystems - Bangalore India 	sctp_set_iplen(sctp, sendmp, fp->sf_ixa);
136*6be61d4eSchandrasekar marimuthu - Sun Microsystems - Bangalore India 	(void) conn_ip_output(sendmp, fp->sf_ixa);
137bd670b35SErik Nordmark 	BUMP_LOCAL(sctp->sctp_opkts);
1387c478bd9Sstevel@tonic-gate 
1397c478bd9Sstevel@tonic-gate done:
1407c478bd9Sstevel@tonic-gate 	sctp->sctp_state = SCTPS_SHUTDOWN_SENT;
1417c478bd9Sstevel@tonic-gate 	SCTP_FADDR_TIMER_RESTART(sctp, sctp->sctp_current,
142*6be61d4eSchandrasekar marimuthu - Sun Microsystems - Bangalore India 	    sctp->sctp_current->sf_rto);
1437c478bd9Sstevel@tonic-gate }
1447c478bd9Sstevel@tonic-gate 
1457c478bd9Sstevel@tonic-gate int
sctp_shutdown_received(sctp_t * sctp,sctp_chunk_hdr_t * sch,boolean_t crwsd,boolean_t rexmit,sctp_faddr_t * fp)14677c67f2fSkcpoon sctp_shutdown_received(sctp_t *sctp, sctp_chunk_hdr_t *sch, boolean_t crwsd,
14777c67f2fSkcpoon     boolean_t rexmit, sctp_faddr_t *fp)
1487c478bd9Sstevel@tonic-gate {
1497c478bd9Sstevel@tonic-gate 	mblk_t *samp;
1507c478bd9Sstevel@tonic-gate 	uint32_t *tsn;
1517c478bd9Sstevel@tonic-gate 	int trysend = 0;
1527c478bd9Sstevel@tonic-gate 
1537c478bd9Sstevel@tonic-gate 	if (sctp->sctp_state != SCTPS_SHUTDOWN_ACK_SENT)
1547c478bd9Sstevel@tonic-gate 		sctp->sctp_state = SCTPS_SHUTDOWN_RECEIVED;
1557c478bd9Sstevel@tonic-gate 
1567c478bd9Sstevel@tonic-gate 	/* Extract and process the TSN in the shutdown chunk */
1577c478bd9Sstevel@tonic-gate 	if (sch != NULL) {
1587c478bd9Sstevel@tonic-gate 		tsn = (uint32_t *)(sch + 1);
159e18a8f3aSchandrasekar marimuthu - Sun Microsystems - Bangalore India 		/* not already acked */
160e18a8f3aSchandrasekar marimuthu - Sun Microsystems - Bangalore India 		if (!SEQ_LT(ntohl(*tsn), sctp->sctp_lastack_rxd))
161e18a8f3aSchandrasekar marimuthu - Sun Microsystems - Bangalore India 			trysend = sctp_cumack(sctp, ntohl(*tsn), &samp);
1627c478bd9Sstevel@tonic-gate 	}
1637c478bd9Sstevel@tonic-gate 
1647c478bd9Sstevel@tonic-gate 	/* Don't allow sending new data */
165c31292eeSkcpoon 	if (!SCTP_IS_DETACHED(sctp) && !sctp->sctp_ulp_discon_done) {
1660f1702c5SYu Xiangning 		sctp->sctp_ulp_opctl(sctp->sctp_ulpd, SOCK_OPCTL_SHUT_SEND, 0);
167c31292eeSkcpoon 		sctp->sctp_ulp_discon_done = B_TRUE;
168c31292eeSkcpoon 	}
1697c478bd9Sstevel@tonic-gate 
1707c478bd9Sstevel@tonic-gate 	/*
1717c478bd9Sstevel@tonic-gate 	 * If there is unsent or unacked data, try sending them out now.
1727c478bd9Sstevel@tonic-gate 	 * The other side should acknowledge them.  After we have flushed
1737c478bd9Sstevel@tonic-gate 	 * the transmit queue, we can complete the shutdown sequence.
1747c478bd9Sstevel@tonic-gate 	 */
1757c478bd9Sstevel@tonic-gate 	if (sctp->sctp_xmit_head != NULL || sctp->sctp_xmit_unsent != NULL)
1767c478bd9Sstevel@tonic-gate 		return (1);
1777c478bd9Sstevel@tonic-gate 
17877c67f2fSkcpoon 	if (fp == NULL) {
17977c67f2fSkcpoon 		/* rotate faddrs if we are retransmitting */
18077c67f2fSkcpoon 		if (!rexmit)
18177c67f2fSkcpoon 			fp = sctp->sctp_current;
18277c67f2fSkcpoon 		else
18377c67f2fSkcpoon 			fp = sctp_rotate_faddr(sctp, sctp->sctp_shutdown_faddr);
18477c67f2fSkcpoon 	}
1857c478bd9Sstevel@tonic-gate 
1863e1dae9fSAnil udupa 	sctp_send_shutdown_ack(sctp, fp, crwsd);
1877c478bd9Sstevel@tonic-gate 
1887c478bd9Sstevel@tonic-gate 	return (trysend);
1897c478bd9Sstevel@tonic-gate }
1907c478bd9Sstevel@tonic-gate 
1917c478bd9Sstevel@tonic-gate void
sctp_shutdown_complete(sctp_t * sctp)1927c478bd9Sstevel@tonic-gate sctp_shutdown_complete(sctp_t *sctp)
1937c478bd9Sstevel@tonic-gate {
1947c478bd9Sstevel@tonic-gate 	mblk_t *scmp;
1957c478bd9Sstevel@tonic-gate 	sctp_chunk_hdr_t *scch;
196f4b3ec61Sdh 	sctp_stack_t	*sctps = sctp->sctp_sctps;
1977c478bd9Sstevel@tonic-gate 
198bd670b35SErik Nordmark 	scmp = sctp_make_mp(sctp, sctp->sctp_current, sizeof (*scch));
1997c478bd9Sstevel@tonic-gate 	if (scmp == NULL) {
2007c478bd9Sstevel@tonic-gate 		/* XXX use timer approach */
201f4b3ec61Sdh 		SCTP_KSTAT(sctps, sctp_send_shutdown_comp_failed);
2027c478bd9Sstevel@tonic-gate 		return;
2037c478bd9Sstevel@tonic-gate 	}
2047c478bd9Sstevel@tonic-gate 
2057c478bd9Sstevel@tonic-gate 	scch = (sctp_chunk_hdr_t *)scmp->b_wptr;
2067c478bd9Sstevel@tonic-gate 	scch->sch_id = CHUNK_SHUTDOWN_COMPLETE;
2077c478bd9Sstevel@tonic-gate 	scch->sch_flags = 0;
2087c478bd9Sstevel@tonic-gate 	scch->sch_len = htons(sizeof (*scch));
2097c478bd9Sstevel@tonic-gate 
2107c478bd9Sstevel@tonic-gate 	scmp->b_wptr += sizeof (*scch);
2117c478bd9Sstevel@tonic-gate 
2127c478bd9Sstevel@tonic-gate 	BUMP_LOCAL(sctp->sctp_obchunks);
2137c478bd9Sstevel@tonic-gate 
214*6be61d4eSchandrasekar marimuthu - Sun Microsystems - Bangalore India 	sctp_set_iplen(sctp, scmp, sctp->sctp_current->sf_ixa);
215*6be61d4eSchandrasekar marimuthu - Sun Microsystems - Bangalore India 	(void) conn_ip_output(scmp, sctp->sctp_current->sf_ixa);
216bd670b35SErik Nordmark 	BUMP_LOCAL(sctp->sctp_opkts);
2177c478bd9Sstevel@tonic-gate }
2187c478bd9Sstevel@tonic-gate 
2197c478bd9Sstevel@tonic-gate /*
2207c478bd9Sstevel@tonic-gate  * Similar to sctp_shutdown_complete(), except that since this
2217c478bd9Sstevel@tonic-gate  * is out-of-the-blue, we can't use an sctp's association information,
2227c478bd9Sstevel@tonic-gate  * and instead must draw all necessary info from the incoming packet.
2237c478bd9Sstevel@tonic-gate  */
2247c478bd9Sstevel@tonic-gate void
sctp_ootb_shutdown_ack(mblk_t * mp,uint_t ip_hdr_len,ip_recv_attr_t * ira,ip_stack_t * ipst)225bd670b35SErik Nordmark sctp_ootb_shutdown_ack(mblk_t *mp, uint_t ip_hdr_len, ip_recv_attr_t *ira,
226bd670b35SErik Nordmark     ip_stack_t *ipst)
2277c478bd9Sstevel@tonic-gate {
2287c478bd9Sstevel@tonic-gate 	boolean_t		isv4;
229bd670b35SErik Nordmark 	ipha_t			*ipha = NULL;
230bd670b35SErik Nordmark 	ip6_t			*ip6h = NULL;
2317c478bd9Sstevel@tonic-gate 	sctp_hdr_t		*insctph;
2327c478bd9Sstevel@tonic-gate 	sctp_chunk_hdr_t	*scch;
2337c478bd9Sstevel@tonic-gate 	int			i;
2347c478bd9Sstevel@tonic-gate 	uint16_t		port;
2357c478bd9Sstevel@tonic-gate 	mblk_t			*mp1;
236bd670b35SErik Nordmark 	netstack_t		*ns = ipst->ips_netstack;
237bd670b35SErik Nordmark 	sctp_stack_t		*sctps = ns->netstack_sctp;
238bd670b35SErik Nordmark 	ip_xmit_attr_t		ixas;
2397c478bd9Sstevel@tonic-gate 
240bd670b35SErik Nordmark 	bzero(&ixas, sizeof (ixas));
2417c478bd9Sstevel@tonic-gate 
242bd670b35SErik Nordmark 	isv4 = (IPH_HDR_VERSION(mp->b_rptr) == IPV4_VERSION);
243bd670b35SErik Nordmark 
244bd670b35SErik Nordmark 	ASSERT(MBLKL(mp) >= sizeof (*insctph) + sizeof (*scch) +
245bd670b35SErik Nordmark 	    (isv4 ? sizeof (ipha_t) : sizeof (ip6_t)));
2467c478bd9Sstevel@tonic-gate 
2477c478bd9Sstevel@tonic-gate 	/*
2487c478bd9Sstevel@tonic-gate 	 * Check to see if we can reuse the incoming mblk.  There should
249bd670b35SErik Nordmark 	 * not be other reference. Since this packet comes from below,
2507c478bd9Sstevel@tonic-gate 	 * there should be enough header space to fill in what the lower
251bd670b35SErik Nordmark 	 * layers want to add.
2527c478bd9Sstevel@tonic-gate 	 */
253bd670b35SErik Nordmark 	if (DB_REF(mp) != 1) {
254bd670b35SErik Nordmark 		mp1 = allocb(MBLKL(mp) + sctps->sctps_wroff_xtra, BPRI_MED);
2557c478bd9Sstevel@tonic-gate 		if (mp1 == NULL) {
256bd670b35SErik Nordmark 			freeb(mp);
2577c478bd9Sstevel@tonic-gate 			return;
2587c478bd9Sstevel@tonic-gate 		}
259f4b3ec61Sdh 		mp1->b_rptr += sctps->sctps_wroff_xtra;
260bd670b35SErik Nordmark 		bcopy(mp->b_rptr, mp1->b_rptr, MBLKL(mp));
261bd670b35SErik Nordmark 		freeb(mp);
262bd670b35SErik Nordmark 		mp = mp1;
263769b977dSvi 	} else {
264bd670b35SErik Nordmark 		DB_CKSUMFLAGS(mp) = 0;
2657c478bd9Sstevel@tonic-gate 	}
2667c478bd9Sstevel@tonic-gate 
267bd670b35SErik Nordmark 	ixas.ixa_pktlen = ip_hdr_len + sizeof (*insctph) + sizeof (*scch);
268bd670b35SErik Nordmark 	ixas.ixa_ip_hdr_length = ip_hdr_len;
269481845d8SGeorge Shepherd 	mp->b_wptr = (mp->b_rptr + ixas.ixa_pktlen);
270481845d8SGeorge Shepherd 
2717c478bd9Sstevel@tonic-gate 	/*
2727c478bd9Sstevel@tonic-gate 	 * We follow the logic in tcp_xmit_early_reset() in that we skip
273bd670b35SErik Nordmark 	 * reversing source route (i.e. replace all IP options with EOL).
2747c478bd9Sstevel@tonic-gate 	 */
2757c478bd9Sstevel@tonic-gate 	if (isv4) {
2767c478bd9Sstevel@tonic-gate 		ipaddr_t	v4addr;
2777c478bd9Sstevel@tonic-gate 
278bd670b35SErik Nordmark 		ipha = (ipha_t *)mp->b_rptr;
2797c478bd9Sstevel@tonic-gate 		for (i = IP_SIMPLE_HDR_LENGTH; i < (int)ip_hdr_len; i++)
280bd670b35SErik Nordmark 			mp->b_rptr[i] = IPOPT_EOL;
2817c478bd9Sstevel@tonic-gate 		/* Swap addresses */
282bd670b35SErik Nordmark 		ipha->ipha_length = htons(ixas.ixa_pktlen);
283bd670b35SErik Nordmark 		v4addr = ipha->ipha_src;
284bd670b35SErik Nordmark 		ipha->ipha_src = ipha->ipha_dst;
285bd670b35SErik Nordmark 		ipha->ipha_dst = v4addr;
286bd670b35SErik Nordmark 		ipha->ipha_ident = 0;
287bd670b35SErik Nordmark 		ipha->ipha_ttl = (uchar_t)sctps->sctps_ipv4_ttl;
288bd670b35SErik Nordmark 
289bd670b35SErik Nordmark 		ixas.ixa_flags = IXAF_BASIC_SIMPLE_V4;
2907c478bd9Sstevel@tonic-gate 	} else {
2917c478bd9Sstevel@tonic-gate 		in6_addr_t	v6addr;
2927c478bd9Sstevel@tonic-gate 
293bd670b35SErik Nordmark 		ip6h = (ip6_t *)mp->b_rptr;
2947c478bd9Sstevel@tonic-gate 		/* Remove any extension headers assuming partial overlay */
2957c478bd9Sstevel@tonic-gate 		if (ip_hdr_len > IPV6_HDR_LEN) {
2967c478bd9Sstevel@tonic-gate 			uint8_t	*to;
2977c478bd9Sstevel@tonic-gate 
298bd670b35SErik Nordmark 			to = mp->b_rptr + ip_hdr_len - IPV6_HDR_LEN;
299