Initial import

Code is based on FreeBSD 8.2 with USB support from Sebastian Huber
and Thomas Doerfler. Initial TCP/IP stack work is from Kevel Kirspel.

1 files changed, 781 insertions, 0 deletions

diff --git a/rtems/freebsd/netinet6/frag6.c b/rtems/freebsd/netinet6/frag6.c
new file mode 100644
index 00000000..b2303e60
--- /dev/null
+++ b/rtems/freebsd/netinet6/frag6.c
@@ -0,0 +1,781 @@
+#include <rtems/freebsd/machine/rtems-bsd-config.h>
+
+/*-
+ * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the project nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	$KAME: frag6.c,v 1.33 2002/01/07 11:34:48 kjc Exp $
+ */
+
+#include <rtems/freebsd/sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <rtems/freebsd/sys/param.h>
+#include <rtems/freebsd/sys/systm.h>
+#include <rtems/freebsd/sys/malloc.h>
+#include <rtems/freebsd/sys/mbuf.h>
+#include <rtems/freebsd/sys/domain.h>
+#include <rtems/freebsd/sys/protosw.h>
+#include <rtems/freebsd/sys/socket.h>
+#include <rtems/freebsd/sys/errno.h>
+#include <rtems/freebsd/sys/time.h>
+#include <rtems/freebsd/sys/kernel.h>
+#include <rtems/freebsd/sys/syslog.h>
+
+#include <rtems/freebsd/net/if.h>
+#include <rtems/freebsd/net/route.h>
+#include <rtems/freebsd/net/vnet.h>
+
+#include <rtems/freebsd/netinet/in.h>
+#include <rtems/freebsd/netinet/in_var.h>
+#include <rtems/freebsd/netinet/ip6.h>
+#include <rtems/freebsd/netinet6/ip6_var.h>
+#include <rtems/freebsd/netinet/icmp6.h>
+#include <rtems/freebsd/netinet/in_systm.h>	/* for ECN definitions */
+#include <rtems/freebsd/netinet/ip.h>		/* for ECN definitions */
+
+#include <rtems/freebsd/security/mac/mac_framework.h>
+
+/*
+ * Define it to get a correct behavior on per-interface statistics.
+ * You will need to perform an extra routing table lookup, per fragment,
+ * to do it.  This may, or may not be, a performance hit.
+ */
+#define IN6_IFSTAT_STRICT
+
+static void frag6_enq(struct ip6asfrag *, struct ip6asfrag *);
+static void frag6_deq(struct ip6asfrag *);
+static void frag6_insque(struct ip6q *, struct ip6q *);
+static void frag6_remque(struct ip6q *);
+static void frag6_freef(struct ip6q *);
+
+static struct mtx ip6qlock;
+/*
+ * These fields all protected by ip6qlock.
+ */
+static VNET_DEFINE(u_int, frag6_nfragpackets);
+static VNET_DEFINE(u_int, frag6_nfrags);
+static VNET_DEFINE(struct ip6q, ip6q);	/* ip6 reassemble queue */
+
+#define	V_frag6_nfragpackets		VNET(frag6_nfragpackets)
+#define	V_frag6_nfrags			VNET(frag6_nfrags)
+#define	V_ip6q				VNET(ip6q)
+
+#define	IP6Q_LOCK_INIT()	mtx_init(&ip6qlock, "ip6qlock", NULL, MTX_DEF);
+#define	IP6Q_LOCK()		mtx_lock(&ip6qlock)
+#define	IP6Q_TRYLOCK()		mtx_trylock(&ip6qlock)
+#define	IP6Q_LOCK_ASSERT()	mtx_assert(&ip6qlock, MA_OWNED)
+#define	IP6Q_UNLOCK()		mtx_unlock(&ip6qlock)
+
+static MALLOC_DEFINE(M_FTABLE, "fragment", "fragment reassembly header");
+
+/*
+ * Initialise reassembly queue and fragment identifier.
+ */
+static void
+frag6_change(void *tag)
+{
+
+	V_ip6_maxfragpackets = nmbclusters / 4;
+	V_ip6_maxfrags = nmbclusters / 4;
+}
+
+void
+frag6_init(void)
+{
+
+	V_ip6_maxfragpackets = nmbclusters / 4;
+	V_ip6_maxfrags = nmbclusters / 4;
+	V_ip6q.ip6q_next = V_ip6q.ip6q_prev = &V_ip6q;
+
+	if (!IS_DEFAULT_VNET(curvnet))
+		return;
+
+	EVENTHANDLER_REGISTER(nmbclusters_change,
+	    frag6_change, NULL, EVENTHANDLER_PRI_ANY);
+
+	IP6Q_LOCK_INIT();
+}
+
+/*
+ * In RFC2460, fragment and reassembly rule do not agree with each other,
+ * in terms of next header field handling in fragment header.
+ * While the sender will use the same value for all of the fragmented packets,
+ * receiver is suggested not to check the consistency.
+ *
+ * fragment rule (p20):
+ *	(2) A Fragment header containing:
+ *	The Next Header value that identifies the first header of
+ *	the Fragmentable Part of the original packet.
+ *		-> next header field is same for all fragments
+ *
+ * reassembly rule (p21):
+ *	The Next Header field of the last header of the Unfragmentable
+ *	Part is obtained from the Next Header field of the first
+ *	fragment's Fragment header.
+ *		-> should grab it from the first fragment only
+ *
+ * The following note also contradicts with fragment rule - noone is going to
+ * send different fragment with different next header field.
+ *
+ * additional note (p22):
+ *	The Next Header values in the Fragment headers of different
+ *	fragments of the same original packet may differ.  Only the value
+ *	from the Offset zero fragment packet is used for reassembly.
+ *		-> should grab it from the first fragment only
+ *
+ * There is no explicit reason given in the RFC.  Historical reason maybe?
+ */
+/*
+ * Fragment input
+ */
+int
+frag6_input(struct mbuf **mp, int *offp, int proto)
+{
+	struct mbuf *m = *mp, *t;
+	struct ip6_hdr *ip6;
+	struct ip6_frag *ip6f;
+	struct ip6q *q6;
+	struct ip6asfrag *af6, *ip6af, *af6dwn;
+#ifdef IN6_IFSTAT_STRICT
+	struct in6_ifaddr *ia;
+#endif
+	int offset = *offp, nxt, i, next;
+	int first_frag = 0;
+	int fragoff, frgpartlen;	/* must be larger than u_int16_t */
+	struct ifnet *dstifp;
+	u_int8_t ecn, ecn0;
+#if 0
+	char ip6buf[INET6_ADDRSTRLEN];
+#endif
+
+	ip6 = mtod(m, struct ip6_hdr *);
+#ifndef PULLDOWN_TEST
+	IP6_EXTHDR_CHECK(m, offset, sizeof(struct ip6_frag), IPPROTO_DONE);
+	ip6f = (struct ip6_frag *)((caddr_t)ip6 + offset);
+#else
+	IP6_EXTHDR_GET(ip6f, struct ip6_frag *, m, offset, sizeof(*ip6f));
+	if (ip6f == NULL)
+		return (IPPROTO_DONE);
+#endif
+
+	dstifp = NULL;
+#ifdef IN6_IFSTAT_STRICT
+	/* find the destination interface of the packet. */
+	if ((ia = ip6_getdstifaddr(m)) != NULL) {
+		dstifp = ia->ia_ifp;
+		ifa_free(&ia->ia_ifa);
+	}
+#else
+	/* we are violating the spec, this is not the destination interface */
+	if ((m->m_flags & M_PKTHDR) != 0)
+		dstifp = m->m_pkthdr.rcvif;
+#endif
+
+	/* jumbo payload can't contain a fragment header */
+	if (ip6->ip6_plen == 0) {
+		icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, offset);
+		in6_ifstat_inc(dstifp, ifs6_reass_fail);
+		return IPPROTO_DONE;
+	}
+
+	/*
+	 * check whether fragment packet's fragment length is
+	 * multiple of 8 octets.
+	 * sizeof(struct ip6_frag) == 8
+	 * sizeof(struct ip6_hdr) = 40
+	 */
+	if ((ip6f->ip6f_offlg & IP6F_MORE_FRAG) &&
+	    (((ntohs(ip6->ip6_plen) - offset) & 0x7) != 0)) {
+		icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
+		    offsetof(struct ip6_hdr, ip6_plen));
+		in6_ifstat_inc(dstifp, ifs6_reass_fail);
+		return IPPROTO_DONE;
+	}
+
+	V_ip6stat.ip6s_fragments++;
+	in6_ifstat_inc(dstifp, ifs6_reass_reqd);
+
+	/* offset now points to data portion */
+	offset += sizeof(struct ip6_frag);
+
+	IP6Q_LOCK();
+
+	/*
+	 * Enforce upper bound on number of fragments.
+	 * If maxfrag is 0, never accept fragments.
+	 * If maxfrag is -1, accept all fragments without limitation.
+	 */
+	if (V_ip6_maxfrags < 0)
+		;
+	else if (V_frag6_nfrags >= (u_int)V_ip6_maxfrags)
+		goto dropfrag;
+
+	for (q6 = V_ip6q.ip6q_next; q6 != &V_ip6q; q6 = q6->ip6q_next)
+		if (ip6f->ip6f_ident == q6->ip6q_ident &&
+		    IN6_ARE_ADDR_EQUAL(&ip6->ip6_src, &q6->ip6q_src) &&
+		    IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &q6->ip6q_dst)
+#ifdef MAC
+		    && mac_ip6q_match(m, q6)
+#endif
+		    )
+			break;
+
+	if (q6 == &V_ip6q) {
+		/*
+		 * the first fragment to arrive, create a reassembly queue.
+		 */
+		first_frag = 1;
+
+		/*
+		 * Enforce upper bound on number of fragmented packets
+		 * for which we attempt reassembly;
+		 * If maxfragpackets is 0, never accept fragments.
+		 * If maxfragpackets is -1, accept all fragments without
+		 * limitation.
+		 */
+		if (V_ip6_maxfragpackets < 0)
+			;
+		else if (V_frag6_nfragpackets >= (u_int)V_ip6_maxfragpackets)
+			goto dropfrag;
+		V_frag6_nfragpackets++;
+		q6 = (struct ip6q *)malloc(sizeof(struct ip6q), M_FTABLE,
+		    M_NOWAIT);
+		if (q6 == NULL)
+			goto dropfrag;
+		bzero(q6, sizeof(*q6));
+#ifdef MAC
+		if (mac_ip6q_init(q6, M_NOWAIT) != 0) {
+			free(q6, M_FTABLE);
+			goto dropfrag;
+		}
+		mac_ip6q_create(m, q6);
+#endif
+		frag6_insque(q6, &V_ip6q);
+
+		/* ip6q_nxt will be filled afterwards, from 1st fragment */
+		q6->ip6q_down	= q6->ip6q_up = (struct ip6asfrag *)q6;
+#ifdef notyet
+		q6->ip6q_nxtp	= (u_char *)nxtp;
+#endif
+		q6->ip6q_ident	= ip6f->ip6f_ident;
+		q6->ip6q_ttl	= IPV6_FRAGTTL;
+		q6->ip6q_src	= ip6->ip6_src;
+		q6->ip6q_dst	= ip6->ip6_dst;
+		q6->ip6q_ecn	=
+		    (ntohl(ip6->ip6_flow) >> 20) & IPTOS_ECN_MASK;
+		q6->ip6q_unfrglen = -1;	/* The 1st fragment has not arrived. */
+
+		q6->ip6q_nfrag = 0;
+	}
+
+	/*
+	 * If it's the 1st fragment, record the length of the
+	 * unfragmentable part and the next header of the fragment header.
+	 */
+	fragoff = ntohs(ip6f->ip6f_offlg & IP6F_OFF_MASK);
+	if (fragoff == 0) {
+		q6->ip6q_unfrglen = offset - sizeof(struct ip6_hdr) -
+		    sizeof(struct ip6_frag);
+		q6->ip6q_nxt = ip6f->ip6f_nxt;
+	}
+
+	/*
+	 * Check that the reassembled packet would not exceed 65535 bytes
+	 * in size.
+	 * If it would exceed, discard the fragment and return an ICMP error.
+	 */
+	frgpartlen = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen) - offset;
+	if (q6->ip6q_unfrglen >= 0) {
+		/* The 1st fragment has already arrived. */
+		if (q6->ip6q_unfrglen + fragoff + frgpartlen > IPV6_MAXPACKET) {
+			icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
+			    offset - sizeof(struct ip6_frag) +
+			    offsetof(struct ip6_frag, ip6f_offlg));
+			IP6Q_UNLOCK();
+			return (IPPROTO_DONE);
+		}
+	} else if (fragoff + frgpartlen > IPV6_MAXPACKET) {
+		icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
+		    offset - sizeof(struct ip6_frag) +
+		    offsetof(struct ip6_frag, ip6f_offlg));
+		IP6Q_UNLOCK();
+		return (IPPROTO_DONE);
+	}
+	/*
+	 * If it's the first fragment, do the above check for each
+	 * fragment already stored in the reassembly queue.
+	 */
+	if (fragoff == 0) {
+		for (af6 = q6->ip6q_down; af6 != (struct ip6asfrag *)q6;
+		     af6 = af6dwn) {
+			af6dwn = af6->ip6af_down;
+
+			if (q6->ip6q_unfrglen + af6->ip6af_off + af6->ip6af_frglen >
+			    IPV6_MAXPACKET) {
+				struct mbuf *merr = IP6_REASS_MBUF(af6);
+				struct ip6_hdr *ip6err;
+				int erroff = af6->ip6af_offset;
+
+				/* dequeue the fragment. */
+				frag6_deq(af6);
+				free(af6, M_FTABLE);
+
+				/* adjust pointer. */
+				ip6err = mtod(merr, struct ip6_hdr *);
+
+				/*
+				 * Restore source and destination addresses
+				 * in the erroneous IPv6 header.
+				 */
+				ip6err->ip6_src = q6->ip6q_src;
+				ip6err->ip6_dst = q6->ip6q_dst;
+
+				icmp6_error(merr, ICMP6_PARAM_PROB,
+				    ICMP6_PARAMPROB_HEADER,
+				    erroff - sizeof(struct ip6_frag) +
+				    offsetof(struct ip6_frag, ip6f_offlg));
+			}
+		}
+	}
+
+	ip6af = (struct ip6asfrag *)malloc(sizeof(struct ip6asfrag), M_FTABLE,
+	    M_NOWAIT);
+	if (ip6af == NULL)
+		goto dropfrag;
+	bzero(ip6af, sizeof(*ip6af));
+	ip6af->ip6af_mff = ip6f->ip6f_offlg & IP6F_MORE_FRAG;
+	ip6af->ip6af_off = fragoff;
+	ip6af->ip6af_frglen = frgpartlen;
+	ip6af->ip6af_offset = offset;
+	IP6_REASS_MBUF(ip6af) = m;
+
+	if (first_frag) {
+		af6 = (struct ip6asfrag *)q6;
+		goto insert;
+	}
+
+	/*
+	 * Handle ECN by comparing this segment with the first one;
+	 * if CE is set, do not lose CE.
+	 * drop if CE and not-ECT are mixed for the same packet.
+	 */
+	ecn = (ntohl(ip6->ip6_flow) >> 20) & IPTOS_ECN_MASK;
+	ecn0 = q6->ip6q_ecn;
+	if (ecn == IPTOS_ECN_CE) {
+		if (ecn0 == IPTOS_ECN_NOTECT) {
+			free(ip6af, M_FTABLE);
+			goto dropfrag;
+		}
+		if (ecn0 != IPTOS_ECN_CE)
+			q6->ip6q_ecn = IPTOS_ECN_CE;
+	}
+	if (ecn == IPTOS_ECN_NOTECT && ecn0 != IPTOS_ECN_NOTECT) {
+		free(ip6af, M_FTABLE);
+		goto dropfrag;
+	}
+
+	/*
+	 * Find a segment which begins after this one does.
+	 */
+	for (af6 = q6->ip6q_down; af6 != (struct ip6asfrag *)q6;
+	     af6 = af6->ip6af_down)
+		if (af6->ip6af_off > ip6af->ip6af_off)
+			break;
+
+#if 0
+	/*
+	 * If there is a preceding segment, it may provide some of
+	 * our data already.  If so, drop the data from the incoming
+	 * segment.  If it provides all of our data, drop us.
+	 */
+	if (af6->ip6af_up != (struct ip6asfrag *)q6) {
+		i = af6->ip6af_up->ip6af_off + af6->ip6af_up->ip6af_frglen
+			- ip6af->ip6af_off;
+		if (i > 0) {
+			if (i >= ip6af->ip6af_frglen)
+				goto dropfrag;
+			m_adj(IP6_REASS_MBUF(ip6af), i);
+			ip6af->ip6af_off += i;
+			ip6af->ip6af_frglen -= i;
+		}
+	}
+
+	/*
+	 * While we overlap succeeding segments trim them or,
+	 * if they are completely covered, dequeue them.
+	 */
+	while (af6 != (struct ip6asfrag *)q6 &&
+	       ip6af->ip6af_off + ip6af->ip6af_frglen > af6->ip6af_off) {
+		i = (ip6af->ip6af_off + ip6af->ip6af_frglen) - af6->ip6af_off;
+		if (i < af6->ip6af_frglen) {
+			af6->ip6af_frglen -= i;
+			af6->ip6af_off += i;
+			m_adj(IP6_REASS_MBUF(af6), i);
+			break;
+		}
+		af6 = af6->ip6af_down;
+		m_freem(IP6_REASS_MBUF(af6->ip6af_up));
+		frag6_deq(af6->ip6af_up);
+	}
+#else
+	/*
+	 * If the incoming framgent overlaps some existing fragments in
+	 * the reassembly queue, drop it, since it is dangerous to override
+	 * existing fragments from a security point of view.
+	 * We don't know which fragment is the bad guy - here we trust
+	 * fragment that came in earlier, with no real reason.
+	 *
+	 * Note: due to changes after disabling this part, mbuf passed to
+	 * m_adj() below now does not meet the requirement.
+	 */
+	if (af6->ip6af_up != (struct ip6asfrag *)q6) {
+		i = af6->ip6af_up->ip6af_off + af6->ip6af_up->ip6af_frglen
+			- ip6af->ip6af_off;
+		if (i > 0) {
+#if 0				/* suppress the noisy log */
+			log(LOG_ERR, "%d bytes of a fragment from %s "
+			    "overlaps the previous fragment\n",
+			    i, ip6_sprintf(ip6buf, &q6->ip6q_src));
+#endif
+			free(ip6af, M_FTABLE);
+			goto dropfrag;
+		}
+	}
+	if (af6 != (struct ip6asfrag *)q6) {
+		i = (ip6af->ip6af_off + ip6af->ip6af_frglen) - af6->ip6af_off;
+		if (i > 0) {
+#if 0				/* suppress the noisy log */
+			log(LOG_ERR, "%d bytes of a fragment from %s "
+			    "overlaps the succeeding fragment",
+			    i, ip6_sprintf(ip6buf, &q6->ip6q_src));
+#endif
+			free(ip6af, M_FTABLE);
+			goto dropfrag;
+		}
+	}
+#endif
+
+insert:
+#ifdef MAC
+	if (!first_frag)
+		mac_ip6q_update(m, q6);
+#endif
+
+	/*
+	 * Stick new segment in its place;
+	 * check for complete reassembly.
+	 * Move to front of packet queue, as we are
+	 * the most recently active fragmented packet.
+	 */
+	frag6_enq(ip6af, af6->ip6af_up);
+	V_frag6_nfrags++;
+	q6->ip6q_nfrag++;
+#if 0 /* xxx */
+	if (q6 != V_ip6q.ip6q_next) {
+		frag6_remque(q6);
+		frag6_insque(q6, &V_ip6q);
+	}
+#endif
+	next = 0;
+	for (af6 = q6->ip6q_down; af6 != (struct ip6asfrag *)q6;
+	     af6 = af6->ip6af_down) {
+		if (af6->ip6af_off != next) {
+			IP6Q_UNLOCK();
+			return IPPROTO_DONE;
+		}
+		next += af6->ip6af_frglen;
+	}
+	if (af6->ip6af_up->ip6af_mff) {
+		IP6Q_UNLOCK();
+		return IPPROTO_DONE;
+	}
+
+	/*
+	 * Reassembly is complete; concatenate fragments.
+	 */
+	ip6af = q6->ip6q_down;
+	t = m = IP6_REASS_MBUF(ip6af);
+	af6 = ip6af->ip6af_down;
+	frag6_deq(ip6af);
+	while (af6 != (struct ip6asfrag *)q6) {
+		af6dwn = af6->ip6af_down;
+		frag6_deq(af6);
+		while (t->m_next)
+			t = t->m_next;
+		t->m_next = IP6_REASS_MBUF(af6);
+		m_adj(t->m_next, af6->ip6af_offset);
+		free(af6, M_FTABLE);
+		af6 = af6dwn;
+	}
+
+	/* adjust offset to point where the original next header starts */
+	offset = ip6af->ip6af_offset - sizeof(struct ip6_frag);
+	free(ip6af, M_FTABLE);
+	ip6 = mtod(m, struct ip6_hdr *);
+	ip6->ip6_plen = htons((u_short)next + offset - sizeof(struct ip6_hdr));
+	if (q6->ip6q_ecn == IPTOS_ECN_CE)
+		ip6->ip6_flow |= htonl(IPTOS_ECN_CE << 20);
+	nxt = q6->ip6q_nxt;
+#ifdef notyet
+	*q6->ip6q_nxtp = (u_char)(nxt & 0xff);
+#endif
+
+	/* Delete frag6 header */
+	if (m->m_len >= offset + sizeof(struct ip6_frag)) {
+		/* This is the only possible case with !PULLDOWN_TEST */
+		ovbcopy((caddr_t)ip6, (caddr_t)ip6 + sizeof(struct ip6_frag),
+		    offset);
+		m->m_data += sizeof(struct ip6_frag);
+		m->m_len -= sizeof(struct ip6_frag);
+	} else {
+		/* this comes with no copy if the boundary is on cluster */
+		if ((t = m_split(m, offset, M_DONTWAIT)) == NULL) {
+			frag6_remque(q6);
+			V_frag6_nfrags -= q6->ip6q_nfrag;
+#ifdef MAC
+			mac_ip6q_destroy(q6);
+#endif
+			free(q6, M_FTABLE);
+			V_frag6_nfragpackets--;
+			goto dropfrag;
+		}
+		m_adj(t, sizeof(struct ip6_frag));
+		m_cat(m, t);
+	}
+
+	/*
+	 * Store NXT to the original.
+	 */
+	{
+		char *prvnxtp = ip6_get_prevhdr(m, offset); /* XXX */
+		*prvnxtp = nxt;
+	}
+
+	frag6_remque(q6);
+	V_frag6_nfrags -= q6->ip6q_nfrag;
+#ifdef MAC
+	mac_ip6q_reassemble(q6, m);
+	mac_ip6q_destroy(q6);
+#endif
+	free(q6, M_FTABLE);
+	V_frag6_nfragpackets--;
+
+	if (m->m_flags & M_PKTHDR) { /* Isn't it always true? */
+		int plen = 0;
+		for (t = m; t; t = t->m_next)
+			plen += t->m_len;
+		m->m_pkthdr.len = plen;
+	}
+
+	V_ip6stat.ip6s_reassembled++;
+	in6_ifstat_inc(dstifp, ifs6_reass_ok);
+
+	/*
+	 * Tell launch routine the next header
+	 */
+
+	*mp = m;
+	*offp = offset;
+
+	IP6Q_UNLOCK();
+	return nxt;
+
+ dropfrag:
+	IP6Q_UNLOCK();
+	in6_ifstat_inc(dstifp, ifs6_reass_fail);
+	V_ip6stat.ip6s_fragdropped++;
+	m_freem(m);
+	return IPPROTO_DONE;
+}
+
+/*
+ * Free a fragment reassembly header and all
+ * associated datagrams.
+ */
+void
+frag6_freef(struct ip6q *q6)
+{
+	struct ip6asfrag *af6, *down6;
+
+	IP6Q_LOCK_ASSERT();
+
+	for (af6 = q6->ip6q_down; af6 != (struct ip6asfrag *)q6;
+	     af6 = down6) {
+		struct mbuf *m = IP6_REASS_MBUF(af6);
+
+		down6 = af6->ip6af_down;
+		frag6_deq(af6);
+
+		/*
+		 * Return ICMP time exceeded error for the 1st fragment.
+		 * Just free other fragments.
+		 */
+		if (af6->ip6af_off == 0) {
+			struct ip6_hdr *ip6;
+
+			/* adjust pointer */
+			ip6 = mtod(m, struct ip6_hdr *);
+
+			/* restore source and destination addresses */
+			ip6->ip6_src = q6->ip6q_src;
+			ip6->ip6_dst = q6->ip6q_dst;
+
+			icmp6_error(m, ICMP6_TIME_EXCEEDED,
+				    ICMP6_TIME_EXCEED_REASSEMBLY, 0);
+		} else
+			m_freem(m);
+		free(af6, M_FTABLE);
+	}
+	frag6_remque(q6);
+	V_frag6_nfrags -= q6->ip6q_nfrag;
+#ifdef MAC
+	mac_ip6q_destroy(q6);
+#endif
+	free(q6, M_FTABLE);
+	V_frag6_nfragpackets--;
+}
+
+/*
+ * Put an ip fragment on a reassembly chain.
+ * Like insque, but pointers in middle of structure.
+ */
+void
+frag6_enq(struct ip6asfrag *af6, struct ip6asfrag *up6)
+{
+
+	IP6Q_LOCK_ASSERT();
+
+	af6->ip6af_up = up6;
+	af6->ip6af_down = up6->ip6af_down;
+	up6->ip6af_down->ip6af_up = af6;
+	up6->ip6af_down = af6;
+}
+
+/*
+ * To frag6_enq as remque is to insque.
+ */
+void
+frag6_deq(struct ip6asfrag *af6)
+{
+
+	IP6Q_LOCK_ASSERT();
+
+	af6->ip6af_up->ip6af_down = af6->ip6af_down;
+	af6->ip6af_down->ip6af_up = af6->ip6af_up;
+}
+
+void
+frag6_insque(struct ip6q *new, struct ip6q *old)
+{
+
+	IP6Q_LOCK_ASSERT();
+
+	new->ip6q_prev = old;
+	new->ip6q_next = old->ip6q_next;
+	old->ip6q_next->ip6q_prev= new;
+	old->ip6q_next = new;
+}
+
+void
+frag6_remque(struct ip6q *p6)
+{
+
+	IP6Q_LOCK_ASSERT();
+
+	p6->ip6q_prev->ip6q_next = p6->ip6q_next;
+	p6->ip6q_next->ip6q_prev = p6->ip6q_prev;
+}
+
+/*
+ * IPv6 reassembling timer processing;
+ * if a timer expires on a reassembly
+ * queue, discard it.
+ */
+void
+frag6_slowtimo(void)
+{
+	VNET_ITERATOR_DECL(vnet_iter);
+	struct ip6q *q6;
+
+	VNET_LIST_RLOCK_NOSLEEP();
+	IP6Q_LOCK();
+	VNET_FOREACH(vnet_iter) {
+		CURVNET_SET(vnet_iter);
+		q6 = V_ip6q.ip6q_next;
+		if (q6)
+			while (q6 != &V_ip6q) {
+				--q6->ip6q_ttl;
+				q6 = q6->ip6q_next;
+				if (q6->ip6q_prev->ip6q_ttl == 0) {
+					V_ip6stat.ip6s_fragtimeout++;
+					/* XXX in6_ifstat_inc(ifp, ifs6_reass_fail) */
+					frag6_freef(q6->ip6q_prev);
+				}
+			}
+		/*
+		 * If we are over the maximum number of fragments
+		 * (due to the limit being lowered), drain off
+		 * enough to get down to the new limit.
+		 */
+		while (V_frag6_nfragpackets > (u_int)V_ip6_maxfragpackets &&
+		    V_ip6q.ip6q_prev) {
+			V_ip6stat.ip6s_fragoverflow++;
+			/* XXX in6_ifstat_inc(ifp, ifs6_reass_fail) */
+			frag6_freef(V_ip6q.ip6q_prev);
+		}
+		CURVNET_RESTORE();
+	}
+	IP6Q_UNLOCK();
+	VNET_LIST_RUNLOCK_NOSLEEP();
+}
+
+/*
+ * Drain off all datagram fragments.
+ */
+void
+frag6_drain(void)
+{
+	VNET_ITERATOR_DECL(vnet_iter);
+
+	VNET_LIST_RLOCK_NOSLEEP();
+	if (IP6Q_TRYLOCK() == 0) {
+		VNET_LIST_RUNLOCK_NOSLEEP();
+		return;
+	}
+	VNET_FOREACH(vnet_iter) {
+		CURVNET_SET(vnet_iter);
+		while (V_ip6q.ip6q_next != &V_ip6q) {
+			V_ip6stat.ip6s_fragdropped++;
+			/* XXX in6_ifstat_inc(ifp, ifs6_reass_fail) */
+			frag6_freef(V_ip6q.ip6q_next);
+		}
+		CURVNET_RESTORE();
+	}
+	IP6Q_UNLOCK();
+	VNET_LIST_RUNLOCK_NOSLEEP();
+}