 @@ -1,2898 +1,2911 @@
-/*	$NetBSD: tcp_input.c,v 1.418 2020/07/06 18:49:12 christos Exp $	*/
+/*	$NetBSD: tcp_input.c,v 1.419 2020/09/02 15:08:46 kardel Exp $	*/
 /*
  * 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.
  */
 /*
  *      @(#)COPYRIGHT   1.1 (NRL) 17 January 1995
+ *
  * NRL grants permission for redistribution and use in source and binary
  * forms, with or without modification, of the software and documentation
  * created at NRL 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. All advertising materials mentioning features or use of this software
  *    must display the following acknowledgements:
  *      This product includes software developed by the University of
  *      California, Berkeley and its contributors.
  *      This product includes software developed at the Information
  *      Technology Division, US Naval Research Laboratory.
  * 4. Neither the name of the NRL nor the names of its contributors
  *    may be used to endorse or promote products derived from this software
  *    without specific prior written permission.
+ *
  * THE SOFTWARE PROVIDED BY NRL IS PROVIDED BY NRL 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 NRL 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.
+ *
  * The views and conclusions contained in the software and documentation
  * are those of the authors and should not be interpreted as representing
  * official policies, either expressed or implied, of the US Naval
  * Research Laboratory (NRL).
  */
 /*-
  * Copyright (c) 1997, 1998, 1999, 2001, 2005, 2006,
  * 2011 The NetBSD Foundation, Inc.
  * All rights reserved.
+ *
  * This code is derived from software contributed to The NetBSD Foundation
  * by Coyote Point Systems, Inc.
  * This code is derived from software contributed to The NetBSD Foundation
  * by Jason R. Thorpe and Kevin M. Lahey of the Numerical Aerospace Simulation
  * Facility, NASA Ames Research Center.
  * This code is derived from software contributed to The NetBSD Foundation
  * by Charles M. Hannum.
  * This code is derived from software contributed to The NetBSD Foundation
  * by Rui Paulo.
+ *
  * 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.
+ *
  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
  */
 /*
  * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1994, 1995
  *	The Regents of the University of California.  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 University 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 REGENTS 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 REGENTS 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.
+ *
  *	@(#)tcp_input.c	8.12 (Berkeley) 5/24/95
  */
 /*
  *	TODO list for SYN cache stuff:
+ *
  *	Find room for a "state" field, which is needed to keep a
  *	compressed state for TIME_WAIT TCBs.  It's been noted already
  *	that this is fairly important for very high-volume web and
  *	mail servers, which use a large number of short-lived
  *	connections.
  */
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: tcp_input.c,v 1.418 2020/07/06 18:49:12 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: tcp_input.c,v 1.419 2020/09/02 15:08:46 kardel Exp $");
 #ifdef _KERNEL_OPT
 #include "opt_inet.h"
 #include "opt_ipsec.h"
 #include "opt_inet_csum.h"
 #include "opt_tcp_debug.h"
 #endif
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/malloc.h>
 #include <sys/mbuf.h>
 #include <sys/protosw.h>
 #include <sys/socket.h>
 #include <sys/socketvar.h>
 #include <sys/errno.h>
 #include <sys/syslog.h>
 #include <sys/pool.h>
 #include <sys/domain.h>
 #include <sys/kernel.h>
 #ifdef TCP_SIGNATURE
 #include <sys/md5.h>
 #endif
 #include <sys/lwp.h> /* for lwp0 */
 #include <sys/cprng.h>
 #include <net/if.h>
 #include <net/if_types.h>
 #include <netinet/in.h>
 #include <netinet/in_systm.h>
 #include <netinet/ip.h>
 #include <netinet/in_pcb.h>
 #include <netinet/in_var.h>
 #include <netinet/ip_var.h>
 #include <netinet/in_offload.h>
 #ifdef INET6
 #include <netinet/ip6.h>
 #include <netinet6/ip6_var.h>
 #include <netinet6/in6_pcb.h>
 #include <netinet6/ip6_var.h>
 #include <netinet6/in6_var.h>
 #include <netinet/icmp6.h>
 #include <netinet6/nd6.h>
 #ifdef TCP_SIGNATURE
 #include <netinet6/scope6_var.h>
 #endif
 #endif
 #ifndef INET6
 #include <netinet/ip6.h>
 #endif
 #include <netinet/tcp.h>
 #include <netinet/tcp_fsm.h>
 #include <netinet/tcp_seq.h>
 #include <netinet/tcp_timer.h>
 #include <netinet/tcp_var.h>
 #include <netinet/tcp_private.h>
 #include <netinet/tcp_congctl.h>
 #include <netinet/tcp_debug.h>
 #ifdef INET6
 #include "faith.h"
 #if defined(NFAITH) && NFAITH > 0
 #include <net/if_faith.h>
 #endif
 #endif
 #ifdef IPSEC
 #include <netipsec/ipsec.h>
 #include <netipsec/key.h>
 #ifdef INET6
 #include <netipsec/ipsec6.h>
 #endif
 #endif	/* IPSEC*/
 #include <netinet/tcp_vtw.h>
 int	tcprexmtthresh = 3;
 int	tcp_log_refused;
 int	tcp_do_autorcvbuf = 1;
 int	tcp_autorcvbuf_inc = 16 * 1024;
 int	tcp_autorcvbuf_max = 256 * 1024;
 int	tcp_msl = (TCPTV_MSL / PR_SLOWHZ);
 static int tcp_rst_ppslim_count = 0;
 static struct timeval tcp_rst_ppslim_last;
 static int tcp_ackdrop_ppslim_count = 0;
 static struct timeval tcp_ackdrop_ppslim_last;
 static void syn_cache_timer(void *);
 #define TCP_PAWS_IDLE	(24U * 24 * 60 * 60 * PR_SLOWHZ)
 /* for modulo comparisons of timestamps */
 #define TSTMP_LT(a,b)	((int)((a)-(b)) < 0)
 #define TSTMP_GEQ(a,b)	((int)((a)-(b)) >= 0)
 /*
  * Neighbor Discovery, Neighbor Unreachability Detection Upper layer hint.
  */
 #ifdef INET6
 static inline void
 nd6_hint(struct tcpcb *tp)
+{
 	struct rtentry *rt = NULL;
 	if (tp != NULL && tp->t_in6pcb != NULL && tp->t_family == AF_INET6 &&
 	    (rt = rtcache_validate(&tp->t_in6pcb->in6p_route)) != NULL) {
 		nd6_nud_hint(rt);
 		rtcache_unref(rt, &tp->t_in6pcb->in6p_route);
+	}
+}
 #else
 static inline void
 nd6_hint(struct tcpcb *tp)
+{
+}
 #endif
 /*
  * Compute ACK transmission behavior.  Delay the ACK unless
  * we have already delayed an ACK (must send an ACK every two segments).
  * We also ACK immediately if we received a PUSH and the ACK-on-PUSH
  * option is enabled.
  */
 static void
 tcp_setup_ack(struct tcpcb *tp, const struct tcphdr *th)
+{
 	if (tp->t_flags & TF_DELACK ||
 	    (tcp_ack_on_push && th->th_flags & TH_PUSH))
 		tp->t_flags |= TF_ACKNOW;
 	else
 		TCP_SET_DELACK(tp);
+}
 static void
 icmp_check(struct tcpcb *tp, const struct tcphdr *th, int acked)
+{
 	/*
 	 * If we had a pending ICMP message that refers to data that have
 	 * just been acknowledged, disregard the recorded ICMP message.
 	 */
 	if ((tp->t_flags & TF_PMTUD_PEND) &&
 	    SEQ_GT(th->th_ack, tp->t_pmtud_th_seq))
 		tp->t_flags &= ~TF_PMTUD_PEND;
 	/*
 	 * Keep track of the largest chunk of data
 	 * acknowledged since last PMTU update
 	 */
 	if (tp->t_pmtud_mss_acked < acked)
 		tp->t_pmtud_mss_acked = acked;
+}
 /*
  * Convert TCP protocol fields to host order for easier processing.
  */
 static void
 tcp_fields_to_host(struct tcphdr *th)
+{
 	NTOHL(th->th_seq);
 	NTOHL(th->th_ack);
 	NTOHS(th->th_win);
 	NTOHS(th->th_urp);
+}
 /*
  * ... and reverse the above.
  */
 static void
 tcp_fields_to_net(struct tcphdr *th)
+{
 	HTONL(th->th_seq);
 	HTONL(th->th_ack);
 	HTONS(th->th_win);
 	HTONS(th->th_urp);
+}
 static void
 tcp_urp_drop(struct tcphdr *th, int todrop, int *tiflags)
+{
 	if (th->th_urp > todrop) {
 		th->th_urp -= todrop;
 	} else {
 		*tiflags &= ~TH_URG;
 		th->th_urp = 0;
+	}
+}
 #ifdef TCP_CSUM_COUNTERS
 #include <sys/device.h>
 extern struct evcnt tcp_hwcsum_ok;
 extern struct evcnt tcp_hwcsum_bad;
 extern struct evcnt tcp_hwcsum_data;
 extern struct evcnt tcp_swcsum;
 #if defined(INET6)
 extern struct evcnt tcp6_hwcsum_ok;
 extern struct evcnt tcp6_hwcsum_bad;
 extern struct evcnt tcp6_hwcsum_data;
 extern struct evcnt tcp6_swcsum;
 #endif /* defined(INET6) */
 #define	TCP_CSUM_COUNTER_INCR(ev)	(ev)->ev_count++
 #else
 #define	TCP_CSUM_COUNTER_INCR(ev)	/* nothing */
 #endif /* TCP_CSUM_COUNTERS */
 #ifdef TCP_REASS_COUNTERS
 #include <sys/device.h>
 extern struct evcnt tcp_reass_;
 extern struct evcnt tcp_reass_empty;
 extern struct evcnt tcp_reass_iteration[8];
 extern struct evcnt tcp_reass_prependfirst;
 extern struct evcnt tcp_reass_prepend;
 extern struct evcnt tcp_reass_insert;
 extern struct evcnt tcp_reass_inserttail;
 extern struct evcnt tcp_reass_append;
 extern struct evcnt tcp_reass_appendtail;
 extern struct evcnt tcp_reass_overlaptail;
 extern struct evcnt tcp_reass_overlapfront;
 extern struct evcnt tcp_reass_segdup;
 extern struct evcnt tcp_reass_fragdup;
 #define	TCP_REASS_COUNTER_INCR(ev)	(ev)->ev_count++
 #else
 #define	TCP_REASS_COUNTER_INCR(ev)	/* nothing */
 #endif /* TCP_REASS_COUNTERS */
 static int tcp_reass(struct tcpcb *, const struct tcphdr *, struct mbuf *,
     int);
 static int tcp_dooptions(struct tcpcb *, const u_char *, int,
     struct tcphdr *, struct mbuf *, int, struct tcp_opt_info *);
 static void tcp4_log_refused(const struct ip *, const struct tcphdr *);
 #ifdef INET6
 static void tcp6_log_refused(const struct ip6_hdr *, const struct tcphdr *);
 #endif
 #if defined(MBUFTRACE)
 struct mowner tcp_reass_mowner = MOWNER_INIT("tcp", "reass");
 #endif /* defined(MBUFTRACE) */
 static struct pool tcpipqent_pool;
 void
 tcpipqent_init(void)
+{
 	pool_init(&tcpipqent_pool, sizeof(struct ipqent), 0, 0, 0, "tcpipqepl",
 	    NULL, IPL_VM);
+}
 struct ipqent *
 tcpipqent_alloc(void)
+{
 	struct ipqent *ipqe;
 	int s;
 	s = splvm();
 	ipqe = pool_get(&tcpipqent_pool, PR_NOWAIT);
 	splx(s);
 	return ipqe;
+}
 void
 tcpipqent_free(struct ipqent *ipqe)
+{
 	int s;
 	s = splvm();
 	pool_put(&tcpipqent_pool, ipqe);
 	splx(s);
+}
 /*
  * Insert segment ti into reassembly queue of tcp with
  * control block tp.  Return TH_FIN if reassembly now includes
  * a segment with FIN.
  */
 static int
 tcp_reass(struct tcpcb *tp, const struct tcphdr *th, struct mbuf *m, int tlen)
+{
 	struct ipqent *p, *q, *nq, *tiqe = NULL;
 	struct socket *so = NULL;
 	int pkt_flags;
 	tcp_seq pkt_seq;
 	unsigned pkt_len;
 	u_long rcvpartdupbyte = 0;
 	u_long rcvoobyte;
 #ifdef TCP_REASS_COUNTERS
 	u_int count = 0;
 #endif
 	uint64_t *tcps;
 	if (tp->t_inpcb)
 		so = tp->t_inpcb->inp_socket;
 #ifdef INET6
 	else if (tp->t_in6pcb)
 		so = tp->t_in6pcb->in6p_socket;
 #endif
 	TCP_REASS_LOCK_CHECK(tp);
 	/*
 	 * Call with th==NULL after become established to
 	 * force pre-ESTABLISHED data up to user socket.
 	 */
 	if (th == NULL)
 		goto present;
 	m_claimm(m, &tcp_reass_mowner);
 	rcvoobyte = tlen;
 	/*
 	 * Copy these to local variables because the TCP header gets munged
 	 * while we are collapsing mbufs.
 	 */
 	pkt_seq = th->th_seq;
 	pkt_len = tlen;
 	pkt_flags = th->th_flags;
 	TCP_REASS_COUNTER_INCR(&tcp_reass_);
 	if ((p = TAILQ_LAST(&tp->segq, ipqehead)) != NULL) {
 		/*
 		 * When we miss a packet, the vast majority of time we get
 		 * packets that follow it in order.  So optimize for that.
 		 */
 		if (pkt_seq == p->ipqe_seq + p->ipqe_len) {
 			p->ipqe_len += pkt_len;
 			p->ipqe_flags |= pkt_flags;
 			m_cat(p->ipqe_m, m);
 			m = NULL;
 			tiqe = p;
 			TAILQ_REMOVE(&tp->timeq, p, ipqe_timeq);
 			TCP_REASS_COUNTER_INCR(&tcp_reass_appendtail);
 			goto skip_replacement;
+		}
 		/*
 		 * While we're here, if the pkt is completely beyond
 		 * anything we have, just insert it at the tail.
 		 */
 		if (SEQ_GT(pkt_seq, p->ipqe_seq + p->ipqe_len)) {
 			TCP_REASS_COUNTER_INCR(&tcp_reass_inserttail);
 			goto insert_it;
+		}
+	}
 	q = TAILQ_FIRST(&tp->segq);
 	if (q != NULL) {
 		/*
 		 * If this segment immediately precedes the first out-of-order
 		 * block, simply slap the segment in front of it and (mostly)
 		 * skip the complicated logic.
 		 */
 		if (pkt_seq + pkt_len == q->ipqe_seq) {
 			q->ipqe_seq = pkt_seq;
 			q->ipqe_len += pkt_len;
 			q->ipqe_flags |= pkt_flags;
 			m_cat(m, q->ipqe_m);
 			q->ipqe_m = m;
 			tiqe = q;
 			TAILQ_REMOVE(&tp->timeq, q, ipqe_timeq);
 			TCP_REASS_COUNTER_INCR(&tcp_reass_prependfirst);
 			goto skip_replacement;
+		}
 	} else {
 		TCP_REASS_COUNTER_INCR(&tcp_reass_empty);
+	}
 	/*
 	 * Find a segment which begins after this one does.
 	 */
 	for (p = NULL; q != NULL; q = nq) {
 		nq = TAILQ_NEXT(q, ipqe_q);
 #ifdef TCP_REASS_COUNTERS
 		count++;
 #endif
 		/*
 		 * If the received segment is just right after this
 		 * fragment, merge the two together and then check
 		 * for further overlaps.
 		 */
 		if (q->ipqe_seq + q->ipqe_len == pkt_seq) {
 			pkt_len += q->ipqe_len;
 			pkt_flags |= q->ipqe_flags;
 			pkt_seq = q->ipqe_seq;
 			m_cat(q->ipqe_m, m);
 			m = q->ipqe_m;
 			TCP_REASS_COUNTER_INCR(&tcp_reass_append);
 			goto free_ipqe;
+		}
 		/*
 		 * If the received segment is completely past this
 		 * fragment, we need to go to the next fragment.
 		 */
 		if (SEQ_LT(q->ipqe_seq + q->ipqe_len, pkt_seq)) {
 			p = q;
 			continue;
+		}
 		/*
 		 * If the fragment is past the received segment,
 		 * it (or any following) can't be concatenated.
 		 */
 		if (SEQ_GT(q->ipqe_seq, pkt_seq + pkt_len)) {
 			TCP_REASS_COUNTER_INCR(&tcp_reass_insert);
 			break;
+		}
 		/*
 		 * We've received all the data in this segment before.
 		 * Mark it as a duplicate and return.
 		 */
 		if (SEQ_LEQ(q->ipqe_seq, pkt_seq) &&
 		    SEQ_GEQ(q->ipqe_seq + q->ipqe_len, pkt_seq + pkt_len)) {
 			tcps = TCP_STAT_GETREF();
 			tcps[TCP_STAT_RCVDUPPACK]++;
 			tcps[TCP_STAT_RCVDUPBYTE] += pkt_len;
 			TCP_STAT_PUTREF();
 			tcp_new_dsack(tp, pkt_seq, pkt_len);
 			m_freem(m);
 			if (tiqe != NULL) {
 				tcpipqent_free(tiqe);
+			}
 			TCP_REASS_COUNTER_INCR(&tcp_reass_segdup);
 			goto out;
+		}
 		/*
 		 * Received segment completely overlaps this fragment
 		 * so we drop the fragment (this keeps the temporal
 		 * ordering of segments correct).
 		 */
 		if (SEQ_GEQ(q->ipqe_seq, pkt_seq) &&
 		    SEQ_LEQ(q->ipqe_seq + q->ipqe_len, pkt_seq + pkt_len)) {
 			rcvpartdupbyte += q->ipqe_len;
 			m_freem(q->ipqe_m);
 			TCP_REASS_COUNTER_INCR(&tcp_reass_fragdup);
 			goto free_ipqe;
+		}
 		/*
 		 * Received segment extends past the end of the fragment.
 		 * Drop the overlapping bytes, merge the fragment and
 		 * segment, and treat as a longer received packet.
 		 */
 		if (SEQ_LT(q->ipqe_seq, pkt_seq) &&
 		    SEQ_GT(q->ipqe_seq + q->ipqe_len, pkt_seq))  {
 			int overlap = q->ipqe_seq + q->ipqe_len - pkt_seq;
 			m_adj(m, overlap);
 			rcvpartdupbyte += overlap;
 			m_cat(q->ipqe_m, m);
 			m = q->ipqe_m;
 			pkt_seq = q->ipqe_seq;
 			pkt_len += q->ipqe_len - overlap;
 			rcvoobyte -= overlap;
 			TCP_REASS_COUNTER_INCR(&tcp_reass_overlaptail);
 			goto free_ipqe;
+		}
 		/*
 		 * Received segment extends past the front of the fragment.
 		 * Drop the overlapping bytes on the received packet. The
 		 * packet will then be concatenated with this fragment a
 		 * bit later.
 		 */
 		if (SEQ_GT(q->ipqe_seq, pkt_seq) &&
 		    SEQ_LT(q->ipqe_seq, pkt_seq + pkt_len))  {
 			int overlap = pkt_seq + pkt_len - q->ipqe_seq;
 			m_adj(m, -overlap);
 			pkt_len -= overlap;
 			rcvpartdupbyte += overlap;
 			TCP_REASS_COUNTER_INCR(&tcp_reass_overlapfront);
 			rcvoobyte -= overlap;
+		}
 		/*
 		 * If the received segment immediately precedes this
 		 * fragment then tack the fragment onto this segment
 		 * and reinsert the data.
 		 */
 		if (q->ipqe_seq == pkt_seq + pkt_len) {
 			pkt_len += q->ipqe_len;
 			pkt_flags |= q->ipqe_flags;
 			m_cat(m, q->ipqe_m);
 			TAILQ_REMOVE(&tp->segq, q, ipqe_q);
 			TAILQ_REMOVE(&tp->timeq, q, ipqe_timeq);
 			tp->t_segqlen--;
 			KASSERT(tp->t_segqlen >= 0);
 			KASSERT(tp->t_segqlen != 0 ||
 			    (TAILQ_EMPTY(&tp->segq) &&
 			    TAILQ_EMPTY(&tp->timeq)));
 			if (tiqe == NULL) {
 				tiqe = q;
 			} else {
 				tcpipqent_free(q);
+			}
 			TCP_REASS_COUNTER_INCR(&tcp_reass_prepend);
 			break;
+		}
 		/*
 		 * If the fragment is before the segment, remember it.
 		 * When this loop is terminated, p will contain the
 		 * pointer to the fragment that is right before the
 		 * received segment.
 		 */
 		if (SEQ_LEQ(q->ipqe_seq, pkt_seq))
 			p = q;
 		continue;
 		/*
 		 * This is a common operation.  It also will allow
 		 * to save doing a malloc/free in most instances.
 		 */
 	  free_ipqe:
 		TAILQ_REMOVE(&tp->segq, q, ipqe_q);
 		TAILQ_REMOVE(&tp->timeq, q, ipqe_timeq);
 		tp->t_segqlen--;
 		KASSERT(tp->t_segqlen >= 0);
 		KASSERT(tp->t_segqlen != 0 ||
 		    (TAILQ_EMPTY(&tp->segq) && TAILQ_EMPTY(&tp->timeq)));
 		if (tiqe == NULL) {
 			tiqe = q;
 		} else {
 			tcpipqent_free(q);
+		}
+	}
 #ifdef TCP_REASS_COUNTERS
 	if (count > 7)
 		TCP_REASS_COUNTER_INCR(&tcp_reass_iteration[0]);
 	else if (count > 0)
 		TCP_REASS_COUNTER_INCR(&tcp_reass_iteration[count]);
 #endif
 insert_it:
 	/*
 	 * Allocate a new queue entry (block) since the received segment
 	 * did not collapse onto any other out-of-order block. If it had
 	 * collapsed, tiqe would not be NULL and we would be reusing it.
+	 *
 	 * If the allocation fails, drop the packet.
 	 */
 	if (tiqe == NULL) {
 		tiqe = tcpipqent_alloc();
 		if (tiqe == NULL) {
 			TCP_STATINC(TCP_STAT_RCVMEMDROP);
 			m_freem(m);
 			goto out;
+		}
+	}
 	/*
 	 * Update the counters.
 	 */
 	tp->t_rcvoopack++;
 	tcps = TCP_STAT_GETREF();
 	tcps[TCP_STAT_RCVOOPACK]++;
 	tcps[TCP_STAT_RCVOOBYTE] += rcvoobyte;
 	if (rcvpartdupbyte) {
 	    tcps[TCP_STAT_RCVPARTDUPPACK]++;
 	    tcps[TCP_STAT_RCVPARTDUPBYTE] += rcvpartdupbyte;
+	}
 	TCP_STAT_PUTREF();
 	/*
 	 * Insert the new fragment queue entry into both queues.
 	 */
 	tiqe->ipqe_m = m;
 	tiqe->ipqe_seq = pkt_seq;
 	tiqe->ipqe_len = pkt_len;
 	tiqe->ipqe_flags = pkt_flags;
 	if (p == NULL) {
 		TAILQ_INSERT_HEAD(&tp->segq, tiqe, ipqe_q);
 	} else {
 		TAILQ_INSERT_AFTER(&tp->segq, p, tiqe, ipqe_q);
+	}
 	tp->t_segqlen++;
 skip_replacement:
 	TAILQ_INSERT_HEAD(&tp->timeq, tiqe, ipqe_timeq);
 present:
 	/*
 	 * Present data to user, advancing rcv_nxt through
 	 * completed sequence space.
 	 */
 	if (TCPS_HAVEESTABLISHED(tp->t_state) == 0)
 		goto out;
 	q = TAILQ_FIRST(&tp->segq);
 	if (q == NULL || q->ipqe_seq != tp->rcv_nxt)
 		goto out;
 	if (tp->t_state == TCPS_SYN_RECEIVED && q->ipqe_len)
 		goto out;
 	tp->rcv_nxt += q->ipqe_len;
 	pkt_flags = q->ipqe_flags & TH_FIN;
 	nd6_hint(tp);
 	TAILQ_REMOVE(&tp->segq, q, ipqe_q);
 	TAILQ_REMOVE(&tp->timeq, q, ipqe_timeq);
 	tp->t_segqlen--;
 	KASSERT(tp->t_segqlen >= 0);
 	KASSERT(tp->t_segqlen != 0 ||
 	    (TAILQ_EMPTY(&tp->segq) && TAILQ_EMPTY(&tp->timeq)));
 	if (so->so_state & SS_CANTRCVMORE)
 		m_freem(q->ipqe_m);
 	else
 		sbappendstream(&so->so_rcv, q->ipqe_m);
 	tcpipqent_free(q);
 	TCP_REASS_UNLOCK(tp);
 	sorwakeup(so);
 	return pkt_flags;
 out:
 	TCP_REASS_UNLOCK(tp);
 	return 0;
+}
 #ifdef INET6
 int
 tcp6_input(struct mbuf **mp, int *offp, int proto)
+{
 	struct mbuf *m = *mp;
 	/*
 	 * draft-itojun-ipv6-tcp-to-anycast
 	 * better place to put this in?
 	 */
 	if (m->m_flags & M_ANYCAST6) {
 		struct ip6_hdr *ip6;
 		if (m->m_len < sizeof(struct ip6_hdr)) {
 			if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
 				TCP_STATINC(TCP_STAT_RCVSHORT);
 				return IPPROTO_DONE;
+			}
+		}
 		ip6 = mtod(m, struct ip6_hdr *);
 		icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADDR,
 		    (char *)&ip6->ip6_dst - (char *)ip6);
 		return IPPROTO_DONE;
+	}
 	tcp_input(m, *offp, proto);
 	return IPPROTO_DONE;
+}
 #endif
 static void
 tcp4_log_refused(const struct ip *ip, const struct tcphdr *th)
+{
 	char src[INET_ADDRSTRLEN];
 	char dst[INET_ADDRSTRLEN];
 	if (ip) {
 		in_print(src, sizeof(src), &ip->ip_src);
 		in_print(dst, sizeof(dst), &ip->ip_dst);
 	} else {
 		strlcpy(src, "(unknown)", sizeof(src));
 		strlcpy(dst, "(unknown)", sizeof(dst));
+	}
 	log(LOG_INFO,
 	    "Connection attempt to TCP %s:%d from %s:%d\n",
 	    dst, ntohs(th->th_dport),
 	    src, ntohs(th->th_sport));
+}
 #ifdef INET6
 static void
 tcp6_log_refused(const struct ip6_hdr *ip6, const struct tcphdr *th)
+{
 	char src[INET6_ADDRSTRLEN];
 	char dst[INET6_ADDRSTRLEN];
 	if (ip6) {
 		in6_print(src, sizeof(src), &ip6->ip6_src);
 		in6_print(dst, sizeof(dst), &ip6->ip6_dst);
 	} else {
 		strlcpy(src, "(unknown v6)", sizeof(src));
 		strlcpy(dst, "(unknown v6)", sizeof(dst));
+	}
 	log(LOG_INFO,
 	    "Connection attempt to TCP [%s]:%d from [%s]:%d\n",
 	    dst, ntohs(th->th_dport),
 	    src, ntohs(th->th_sport));
+}
 #endif
 /*
  * Checksum extended TCP header and data.
  */
 int
 tcp_input_checksum(int af, struct mbuf *m, const struct tcphdr *th,
     int toff, int off, int tlen)
+{
 	struct ifnet *rcvif;
 	int s;
 	/*
 	 * XXX it's better to record and check if this mbuf is
 	 * already checked.
 	 */
 	rcvif = m_get_rcvif(m, &s);
 	if (__predict_false(rcvif == NULL))
 		goto badcsum; /* XXX */
 	switch (af) {
 	case AF_INET:
 		switch (m->m_pkthdr.csum_flags &
 			((rcvif->if_csum_flags_rx & M_CSUM_TCPv4) |
 			 M_CSUM_TCP_UDP_BAD | M_CSUM_DATA)) {
 		case M_CSUM_TCPv4|M_CSUM_TCP_UDP_BAD:
 			TCP_CSUM_COUNTER_INCR(&tcp_hwcsum_bad);
 			goto badcsum;
 		case M_CSUM_TCPv4|M_CSUM_DATA: {
 			u_int32_t hw_csum = m->m_pkthdr.csum_data;
 			TCP_CSUM_COUNTER_INCR(&tcp_hwcsum_data);
 			if (m->m_pkthdr.csum_flags & M_CSUM_NO_PSEUDOHDR) {
 				const struct ip *ip =
 				    mtod(m, const struct ip *);
 				hw_csum = in_cksum_phdr(ip->ip_src.s_addr,
 				    ip->ip_dst.s_addr,
 				    htons(hw_csum + tlen + off + IPPROTO_TCP));
+			}
 			if ((hw_csum ^ 0xffff) != 0)
 				goto badcsum;
 			break;
+		}
 		case M_CSUM_TCPv4:
 			/* Checksum was okay. */
 			TCP_CSUM_COUNTER_INCR(&tcp_hwcsum_ok);
 			break;
 		default:
 			/*
 			 * Must compute it ourselves.  Maybe skip checksum
 			 * on loopback interfaces.
 			 */
 			if (__predict_true(!(rcvif->if_flags & IFF_LOOPBACK) ||
 					   tcp_do_loopback_cksum)) {
 				TCP_CSUM_COUNTER_INCR(&tcp_swcsum);
 				if (in4_cksum(m, IPPROTO_TCP, toff,
 					      tlen + off) != 0)
 					goto badcsum;
+			}
 			break;
+		}
 		break;
 #ifdef INET6
 	case AF_INET6:
 		switch (m->m_pkthdr.csum_flags &
 			((rcvif->if_csum_flags_rx & M_CSUM_TCPv6) |
 			 M_CSUM_TCP_UDP_BAD | M_CSUM_DATA)) {
 		case M_CSUM_TCPv6|M_CSUM_TCP_UDP_BAD:
 			TCP_CSUM_COUNTER_INCR(&tcp6_hwcsum_bad);
 			goto badcsum;
 #if 0 /* notyet */
 		case M_CSUM_TCPv6|M_CSUM_DATA:
 #endif
 		case M_CSUM_TCPv6:
 			/* Checksum was okay. */
 			TCP_CSUM_COUNTER_INCR(&tcp6_hwcsum_ok);
 			break;
 		default:
 			/*
 			 * Must compute it ourselves.  Maybe skip checksum
 			 * on loopback interfaces.
 			 */
 			if (__predict_true((m->m_flags & M_LOOP) == 0 ||
 			    tcp_do_loopback_cksum)) {
 				TCP_CSUM_COUNTER_INCR(&tcp6_swcsum);
 				if (in6_cksum(m, IPPROTO_TCP, toff,
 				    tlen + off) != 0)
 					goto badcsum;
+			}
+		}
 		break;
 #endif /* INET6 */
+	}
 	m_put_rcvif(rcvif, &s);
 	return 0;
 badcsum:
 	m_put_rcvif(rcvif, &s);
 	TCP_STATINC(TCP_STAT_RCVBADSUM);
 	return -1;
+}
 /*
  * When a packet arrives addressed to a vestigial tcpbp, we
  * nevertheless have to respond to it per the spec.
+ *
  * This code is duplicated from the one in tcp_input().
  */
 static void tcp_vtw_input(struct tcphdr *th, vestigial_inpcb_t *vp,
     struct mbuf *m, int tlen)
+{
 	int tiflags;
 	int todrop;
 	uint32_t t_flags = 0;
 	uint64_t *tcps;
 	tiflags = th->th_flags;
 	todrop  = vp->rcv_nxt - th->th_seq;
 	if (todrop > 0) {
 		if (tiflags & TH_SYN) {
 			tiflags &= ~TH_SYN;
 			th->th_seq++;
 			tcp_urp_drop(th, 1, &tiflags);
 			todrop--;
+		}
 		if (todrop > tlen ||
 		    (todrop == tlen && (tiflags & TH_FIN) == 0)) {
 			/*
 			 * Any valid FIN or RST must be to the left of the
 			 * window.  At this point the FIN or RST must be a
 			 * duplicate or out of sequence; drop it.
 			 */
 			if (tiflags & TH_RST)
 				goto drop;
 			tiflags &= ~(TH_FIN|TH_RST);
 			/*
 			 * Send an ACK to resynchronize and drop any data.
 			 * But keep on processing for RST or ACK.
 			 */
 			t_flags |= TF_ACKNOW;
 			todrop = tlen;
 			tcps = TCP_STAT_GETREF();
 			tcps[TCP_STAT_RCVDUPPACK] += 1;
 			tcps[TCP_STAT_RCVDUPBYTE] += todrop;
 			TCP_STAT_PUTREF();
 		} else if ((tiflags & TH_RST) &&
 		    th->th_seq != vp->rcv_nxt) {
 			/*
 			 * Test for reset before adjusting the sequence
 			 * number for overlapping data.
 			 */
 			goto dropafterack_ratelim;
 		} else {
 			tcps = TCP_STAT_GETREF();
 			tcps[TCP_STAT_RCVPARTDUPPACK] += 1;
 			tcps[TCP_STAT_RCVPARTDUPBYTE] += todrop;
 			TCP_STAT_PUTREF();
+		}
 //		tcp_new_dsack(tp, th->th_seq, todrop);
 //		hdroptlen += todrop;	/*drop from head afterwards*/
 		th->th_seq += todrop;
 		tlen -= todrop;
 		tcp_urp_drop(th, todrop, &tiflags);
+	}
 	/*
 	 * If new data are received on a connection after the
 	 * user processes are gone, then RST the other end.
 	 */
 	if (tlen) {
 		TCP_STATINC(TCP_STAT_RCVAFTERCLOSE);
 		goto dropwithreset;
+	}
 	/*
 	 * If segment ends after window, drop trailing data
 	 * (and PUSH and FIN); if nothing left, just ACK.
 	 */
 	todrop = (th->th_seq + tlen) - (vp->rcv_nxt + vp->rcv_wnd);
 	if (todrop > 0) {
 		TCP_STATINC(TCP_STAT_RCVPACKAFTERWIN);
 		if (todrop >= tlen) {
 			/*
 			 * The segment actually starts after the window.
 			 * th->th_seq + tlen - vp->rcv_nxt - vp->rcv_wnd >= tlen
 			 * th->th_seq - vp->rcv_nxt - vp->rcv_wnd >= 0
 			 * th->th_seq >= vp->rcv_nxt + vp->rcv_wnd
 			 */
 			TCP_STATADD(TCP_STAT_RCVBYTEAFTERWIN, tlen);
 			/*
 			 * If a new connection request is received
 			 * while in TIME_WAIT, drop the old connection
 			 * and start over if the sequence numbers
 			 * are above the previous ones.
 			 */
 			if ((tiflags & TH_SYN) &&
 			    SEQ_GT(th->th_seq, vp->rcv_nxt)) {
 				/*
 				 * We only support this in the !NOFDREF case, which
 				 * is to say: not here.
 				 */
 				goto dropwithreset;
+			}
 			/*
 			 * If window is closed can only take segments at
 			 * window edge, and have to drop data and PUSH from
 			 * incoming segments.  Continue processing, but
 			 * remember to ack.  Otherwise, drop segment
 			 * and (if not RST) ack.
 			 */
 			if (vp->rcv_wnd == 0 && th->th_seq == vp->rcv_nxt) {
 				t_flags |= TF_ACKNOW;
 				TCP_STATINC(TCP_STAT_RCVWINPROBE);
 			} else {
 				goto dropafterack;
+			}
 		} else {
 			TCP_STATADD(TCP_STAT_RCVBYTEAFTERWIN, todrop);
+		}
 		m_adj(m, -todrop);
 		tlen -= todrop;
 		tiflags &= ~(TH_PUSH|TH_FIN);
+	}
 	if (tiflags & TH_RST) {
 		if (th->th_seq != vp->rcv_nxt)
 			goto dropafterack_ratelim;
 		vtw_del(vp->ctl, vp->vtw);
 		goto drop;
+	}
 	/*
 	 * If the ACK bit is off we drop the segment and return.
 	 */
 	if ((tiflags & TH_ACK) == 0) {
 		if (t_flags & TF_ACKNOW)
 			goto dropafterack;
 		goto drop;
+	}
 	/*
 	 * In TIME_WAIT state the only thing that should arrive
 	 * is a retransmission of the remote FIN.  Acknowledge
 	 * it and restart the finack timer.
 	 */
 	vtw_restart(vp);
 	goto dropafterack;
 dropafterack:
 	/*
 	 * Generate an ACK dropping incoming segment if it occupies
 	 * sequence space, where the ACK reflects our state.
 	 */
 	if (tiflags & TH_RST)
 		goto drop;
 	goto dropafterack2;
 dropafterack_ratelim:
 	/*
 	 * We may want to rate-limit ACKs against SYN/RST attack.
 	 */
 	if (ppsratecheck(&tcp_ackdrop_ppslim_last, &tcp_ackdrop_ppslim_count,
 	    tcp_ackdrop_ppslim) == 0) {
 		/* XXX stat */
 		goto drop;
+	}
 	/* ...fall into dropafterack2... */
 dropafterack2:
 	(void)tcp_respond(0, m, m, th, th->th_seq + tlen, th->th_ack, TH_ACK);
 	return;
 dropwithreset:
 	/*
 	 * Generate a RST, dropping incoming segment.
 	 * Make ACK acceptable to originator of segment.
 	 */
 	if (tiflags & TH_RST)
 		goto drop;
 	if (tiflags & TH_ACK) {
 		tcp_respond(0, m, m, th, (tcp_seq)0, th->th_ack, TH_RST);
 	} else {
 		if (tiflags & TH_SYN)
 			++tlen;
 		(void)tcp_respond(0, m, m, th, th->th_seq + tlen, (tcp_seq)0,
 		    TH_RST|TH_ACK);
+	}
 	return;
 drop:
 	m_freem(m);
+}
 /*
  * TCP input routine, follows pages 65-76 of RFC 793 very closely.
  */
 void
 tcp_input(struct mbuf *m, int off, int proto)
+{
 	struct tcphdr *th;
 	struct ip *ip;
 	struct inpcb *inp;
 #ifdef INET6
 	struct ip6_hdr *ip6;
 	struct in6pcb *in6p;
 #endif
 	u_int8_t *optp = NULL;
 	int optlen = 0;
 	int len, tlen, hdroptlen = 0;
 	struct tcpcb *tp = NULL;
 	int tiflags;
 	struct socket *so = NULL;
 	int todrop, acked, ourfinisacked, needoutput = 0;
 	bool dupseg;
 #ifdef TCP_DEBUG
 	short ostate = 0;
 #endif
 	u_long tiwin;
 	struct tcp_opt_info opti;
 	int thlen, iphlen;
 	int af;		/* af on the wire */
 	struct mbuf *tcp_saveti = NULL;
 	uint32_t ts_rtt;
 	uint8_t iptos;
 	uint64_t *tcps;
 	vestigial_inpcb_t vestige;
 	vestige.valid = 0;
 	MCLAIM(m, &tcp_rx_mowner);
 	TCP_STATINC(TCP_STAT_RCVTOTAL);
 	memset(&opti, 0, sizeof(opti));
 	opti.ts_present = 0;
 	opti.maxseg = 0;
 	/*
 	 * RFC1122 4.2.3.10, p. 104: discard bcast/mcast SYN.
+	 *
 	 * TCP is, by definition, unicast, so we reject all
 	 * multicast outright.
+	 *
 	 * Note, there are additional src/dst address checks in
 	 * the AF-specific code below.
 	 */
 	if (m->m_flags & (M_BCAST|M_MCAST)) {
 		/* XXX stat */
 		goto drop;
+	}
 #ifdef INET6
 	if (m->m_flags & M_ANYCAST6) {
 		/* XXX stat */
 		goto drop;
+	}
 #endif
 	M_REGION_GET(th, struct tcphdr *, m, off, sizeof(struct tcphdr));
 	if (th == NULL) {
 		TCP_STATINC(TCP_STAT_RCVSHORT);
 		return;
+	}
 	/*
 	 * Enforce alignment requirements that are violated in
 	 * some cases, see kern/50766 for details.
 	 */
 	if (TCP_HDR_ALIGNED_P(th) == 0) {
 		m = m_copyup(m, off + sizeof(struct tcphdr), 0);
 		if (m == NULL) {
 			TCP_STATINC(TCP_STAT_RCVSHORT);
 			return;
+		}
 		th = (struct tcphdr *)(mtod(m, char *) + off);
+	}
 	KASSERT(TCP_HDR_ALIGNED_P(th));
 	/*
 	 * Get IP and TCP header.
 	 * Note: IP leaves IP header in first mbuf.
 	 */
 	ip = mtod(m, struct ip *);
 #ifdef INET6
 	ip6 = mtod(m, struct ip6_hdr *);
 #endif
 	switch (ip->ip_v) {
 	case 4:
 		af = AF_INET;
 		iphlen = sizeof(struct ip);
 		if (IN_MULTICAST(ip->ip_dst.s_addr) ||
 		    in_broadcast(ip->ip_dst, m_get_rcvif_NOMPSAFE(m)))
 			goto drop;
 		/* We do the checksum after PCB lookup... */
 		len = ntohs(ip->ip_len);
 		tlen = len - off;
 		iptos = ip->ip_tos;
 		break;
 #ifdef INET6
 	case 6:
 		iphlen = sizeof(struct ip6_hdr);
 		af = AF_INET6;
 		/*
 		 * Be proactive about unspecified IPv6 address in source.
 		 * As we use all-zero to indicate unbounded/unconnected pcb,
 		 * unspecified IPv6 address can be used to confuse us.
+		 *
 		 * Note that packets with unspecified IPv6 destination is
 		 * already dropped in ip6_input.
 		 */
 		if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src)) {
 			/* XXX stat */
 			goto drop;
+		}
 		/*
 		 * Make sure destination address is not multicast.
 		 * Source address checked in ip6_input().
 		 */
 		if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 			/* XXX stat */
 			goto drop;
+		}
 		/* We do the checksum after PCB lookup... */
 		len = m->m_pkthdr.len;
 		tlen = len - off;
 		iptos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
 		break;
 #endif
 	default:
 		m_freem(m);
 		return;
+	}
 	/*
 	 * Check that TCP offset makes sense, pull out TCP options and
 	 * adjust length.
 	 */
 	thlen = th->th_off << 2;
 	if (thlen < sizeof(struct tcphdr) || thlen > tlen) {
 		TCP_STATINC(TCP_STAT_RCVBADOFF);
 		goto drop;
+	}
 	tlen -= thlen;
 	if (thlen > sizeof(struct tcphdr)) {
 		M_REGION_GET(th, struct tcphdr *, m, off, thlen);
 		if (th == NULL) {
 			TCP_STATINC(TCP_STAT_RCVSHORT);
 			return;
+		}
 		KASSERT(TCP_HDR_ALIGNED_P(th));
 		optlen = thlen - sizeof(struct tcphdr);
 		optp = ((u_int8_t *)th) + sizeof(struct tcphdr);
 		/*
 		 * Do quick retrieval of timestamp options.
+		 *
 		 * If timestamp is the only option and it's formatted as
 		 * recommended in RFC 1323 appendix A, we quickly get the
 		 * values now and don't bother calling tcp_dooptions(),
 		 * etc.
 		 */
 		if ((optlen == TCPOLEN_TSTAMP_APPA ||
 		     (optlen > TCPOLEN_TSTAMP_APPA &&
 		      optp[TCPOLEN_TSTAMP_APPA] == TCPOPT_EOL)) &&
 		    be32dec(optp) == TCPOPT_TSTAMP_HDR &&
 		    (th->th_flags & TH_SYN) == 0) {
 			opti.ts_present = 1;
 			opti.ts_val = be32dec(optp + 4);
 			opti.ts_ecr = be32dec(optp + 8);
 			optp = NULL;	/* we've parsed the options */
+		}
+	}
 	tiflags = th->th_flags;
 	/*
 	 * Checksum extended TCP header and data
 	 */
 	if (tcp_input_checksum(af, m, th, off, thlen, tlen))
 		goto badcsum;
 	/*
 	 * Locate pcb for segment.
 	 */
 findpcb:
 	inp = NULL;
 #ifdef INET6
 	in6p = NULL;
 #endif
 	switch (af) {
 	case AF_INET:
 		inp = in_pcblookup_connect(&tcbtable, ip->ip_src, th->th_sport,
 		    ip->ip_dst, th->th_dport, &vestige);
 		if (inp == NULL && !vestige.valid) {
 			TCP_STATINC(TCP_STAT_PCBHASHMISS);
 			inp = in_pcblookup_bind(&tcbtable, ip->ip_dst,
 			    th->th_dport);
+		}
 #ifdef INET6
 		if (inp == NULL && !vestige.valid) {
 			struct in6_addr s, d;
 			/* mapped addr case */
 			in6_in_2_v4mapin6(&ip->ip_src, &s);
 			in6_in_2_v4mapin6(&ip->ip_dst, &d);
 			in6p = in6_pcblookup_connect(&tcbtable, &s,
 			    th->th_sport, &d, th->th_dport, 0, &vestige);
 			if (in6p == 0 && !vestige.valid) {
 				TCP_STATINC(TCP_STAT_PCBHASHMISS);
 				in6p = in6_pcblookup_bind(&tcbtable, &d,
 				    th->th_dport, 0);
+			}
+		}
 #endif
 #ifndef INET6
 		if (inp == NULL && !vestige.valid)
 #else
 		if (inp == NULL && in6p == NULL && !vestige.valid)
 #endif
+		{
 			TCP_STATINC(TCP_STAT_NOPORT);
 			if (tcp_log_refused &&
 			    (tiflags & (TH_RST|TH_ACK|TH_SYN)) == TH_SYN) {
 				tcp4_log_refused(ip, th);
+			}
 			tcp_fields_to_host(th);
 			goto dropwithreset_ratelim;
+		}
 #if defined(IPSEC)
 		if (ipsec_used) {
 			if (inp && ipsec_in_reject(m, inp)) {
 				goto drop;
+			}
 #ifdef INET6
 			else if (in6p && ipsec_in_reject(m, in6p)) {
 				goto drop;
+			}
 #endif
+		}
 #endif /*IPSEC*/
 		break;
 #ifdef INET6
 	case AF_INET6:
+	    {
 		int faith;
 #if defined(NFAITH) && NFAITH > 0
 		faith = faithprefix(&ip6->ip6_dst);
 #else
 		faith = 0;
 #endif
 		in6p = in6_pcblookup_connect(&tcbtable, &ip6->ip6_src,
 		    th->th_sport, &ip6->ip6_dst, th->th_dport, faith, &vestige);
 		if (!in6p && !vestige.valid) {
 			TCP_STATINC(TCP_STAT_PCBHASHMISS);
 			in6p = in6_pcblookup_bind(&tcbtable, &ip6->ip6_dst,
 			    th->th_dport, faith);
+		}
 		if (!in6p && !vestige.valid) {
 			TCP_STATINC(TCP_STAT_NOPORT);
 			if (tcp_log_refused &&
 			    (tiflags & (TH_RST|TH_ACK|TH_SYN)) == TH_SYN) {
 				tcp6_log_refused(ip6, th);
+			}
 			tcp_fields_to_host(th);
 			goto dropwithreset_ratelim;
+		}
 #if defined(IPSEC)
 		if (ipsec_used && in6p && ipsec_in_reject(m, in6p)) {
 			goto drop;
+		}
 #endif
 		break;
+	    }
 #endif
+	}
 	tcp_fields_to_host(th);
 	/*
 	 * If the state is CLOSED (i.e., TCB does not exist) then
 	 * all data in the incoming segment is discarded.
 	 * If the TCB exists but is in CLOSED state, it is embryonic,
 	 * but should either do a listen or a connect soon.
 	 */
 	tp = NULL;
 	so = NULL;
 	if (inp) {
 		/* Check the minimum TTL for socket. */
 		if (ip->ip_ttl < inp->inp_ip_minttl)
 			goto drop;
 		tp = intotcpcb(inp);
 		so = inp->inp_socket;
+	}
 #ifdef INET6
 	else if (in6p) {
 		tp = in6totcpcb(in6p);
 		so = in6p->in6p_socket;
+	}
 #endif
 	else if (vestige.valid) {
 		/* We do not support the resurrection of vtw tcpcps. */
 		tcp_vtw_input(th, &vestige, m, tlen);
 		m = NULL;
 		goto drop;
+	}
 	if (tp == NULL)
 		goto dropwithreset_ratelim;
 	if (tp->t_state == TCPS_CLOSED)
 		goto drop;
 	KASSERT(so->so_lock == softnet_lock);
 	KASSERT(solocked(so));
 	/* Unscale the window into a 32-bit value. */
 	if ((tiflags & TH_SYN) == 0)
 		tiwin = th->th_win << tp->snd_scale;
 	else
 		tiwin = th->th_win;
 #ifdef INET6
 	/* save packet options if user wanted */
 	if (in6p && (in6p->in6p_flags & IN6P_CONTROLOPTS)) {
 		if (in6p->in6p_options) {
 			m_freem(in6p->in6p_options);
 			in6p->in6p_options = NULL;
+		}
 		ip6_savecontrol(in6p, &in6p->in6p_options, ip6, m);
+	}
 #endif
 	if (so->so_options & SO_DEBUG) {
 #ifdef TCP_DEBUG
 		ostate = tp->t_state;
 #endif
 		tcp_saveti = NULL;
 		if (iphlen + sizeof(struct tcphdr) > MHLEN)
 			goto nosave;
 		if (m->m_len > iphlen && (m->m_flags & M_EXT) == 0) {
 			tcp_saveti = m_copym(m, 0, iphlen, M_DONTWAIT);
 			if (tcp_saveti == NULL)
 				goto nosave;
 		} else {
 			MGETHDR(tcp_saveti, M_DONTWAIT, MT_HEADER);
 			if (tcp_saveti == NULL)
 				goto nosave;
 			MCLAIM(m, &tcp_mowner);
 			tcp_saveti->m_len = iphlen;
 			m_copydata(m, 0, iphlen,
 			    mtod(tcp_saveti, void *));
+		}
 		if (M_TRAILINGSPACE(tcp_saveti) < sizeof(struct tcphdr)) {
 			m_freem(tcp_saveti);
 			tcp_saveti = NULL;
 		} else {
 			tcp_saveti->m_len += sizeof(struct tcphdr);
 			memcpy(mtod(tcp_saveti, char *) + iphlen, th,
 			    sizeof(struct tcphdr));
+		}
 nosave:;
+	}
 	if (so->so_options & SO_ACCEPTCONN) {
 		union syn_cache_sa src;
 		union syn_cache_sa dst;
 		KASSERT(tp->t_state == TCPS_LISTEN);
 		memset(&src, 0, sizeof(src));
 		memset(&dst, 0, sizeof(dst));
 		switch (af) {
 		case AF_INET:
 			src.sin.sin_len = sizeof(struct sockaddr_in);
 			src.sin.sin_family = AF_INET;
 			src.sin.sin_addr = ip->ip_src;
 			src.sin.sin_port = th->th_sport;
 			dst.sin.sin_len = sizeof(struct sockaddr_in);
 			dst.sin.sin_family = AF_INET;
 			dst.sin.sin_addr = ip->ip_dst;
 			dst.sin.sin_port = th->th_dport;
 			break;
 #ifdef INET6
 		case AF_INET6:
 			src.sin6.sin6_len = sizeof(struct sockaddr_in6);
 			src.sin6.sin6_family = AF_INET6;
 			src.sin6.sin6_addr = ip6->ip6_src;
 			src.sin6.sin6_port = th->th_sport;
 			dst.sin6.sin6_len = sizeof(struct sockaddr_in6);
 			dst.sin6.sin6_family = AF_INET6;
 			dst.sin6.sin6_addr = ip6->ip6_dst;
 			dst.sin6.sin6_port = th->th_dport;
 			break;
 #endif
+		}
 		if ((tiflags & (TH_RST|TH_ACK|TH_SYN)) != TH_SYN) {
 			if (tiflags & TH_RST) {
 				syn_cache_reset(&src.sa, &dst.sa, th);
 			} else if ((tiflags & (TH_ACK|TH_SYN)) ==
 			    (TH_ACK|TH_SYN)) {
 				/*
 				 * Received a SYN,ACK. This should never
 				 * happen while we are in LISTEN. Send an RST.
 				 */
 				goto badsyn;
 			} else if (tiflags & TH_ACK) {
 				so = syn_cache_get(&src.sa, &dst.sa, th, so, m);
 				if (so == NULL) {
 					/*
 					 * We don't have a SYN for this ACK;
 					 * send an RST.
 					 */
 					goto badsyn;
 				} else if (so == (struct socket *)(-1)) {
 					/*
 					 * We were unable to create the
 					 * connection. If the 3-way handshake
 					 * was completed, and RST has been
 					 * sent to the peer. Since the mbuf
 					 * might be in use for the reply, do
 					 * not free it.
 					 */
 					m = NULL;
 				} else {
 					/*
 					 * We have created a full-blown
 					 * connection.
 					 */
 					tp = NULL;
 					inp = NULL;
 #ifdef INET6
 					in6p = NULL;
 #endif
 					switch (so->so_proto->pr_domain->dom_family) {
 					case AF_INET:
 						inp = sotoinpcb(so);
 						tp = intotcpcb(inp);
 						break;
 #ifdef INET6
 					case AF_INET6:
 						in6p = sotoin6pcb(so);
 						tp = in6totcpcb(in6p);
 						break;
 #endif
+					}
 					if (tp == NULL)
 						goto badsyn;	/*XXX*/
 					tiwin <<= tp->snd_scale;
 					goto after_listen;
+				}
 			} else {
 				/*
 				 * None of RST, SYN or ACK was set.
 				 * This is an invalid packet for a
 				 * TCB in LISTEN state.  Send a RST.
 				 */
 				goto badsyn;
+			}
 		} else {
 			/*
 			 * Received a SYN.
 			 */
 #ifdef INET6
 			/*
 			 * If deprecated address is forbidden, we do
 			 * not accept SYN to deprecated interface
 			 * address to prevent any new inbound
 			 * connection from getting established.
 			 * When we do not accept SYN, we send a TCP
 			 * RST, with deprecated source address (instead
 			 * of dropping it).  We compromise it as it is
 			 * much better for peer to send a RST, and
 			 * RST will be the final packet for the
 			 * exchange.
+			 *
 			 * If we do not forbid deprecated addresses, we
 			 * accept the SYN packet.  RFC2462 does not
 			 * suggest dropping SYN in this case.
 			 * If we decipher RFC2462 5.5.4, it says like
 			 * this:
 			 * 1. use of deprecated addr with existing
 			 *    communication is okay - "SHOULD continue
 			 *    to be used"
 			 * 2. use of it with new communication:
 			 *   (2a) "SHOULD NOT be used if alternate
 			 *        address with sufficient scope is
 			 *        available"
 			 *   (2b) nothing mentioned otherwise.
 			 * Here we fall into (2b) case as we have no
 			 * choice in our source address selection - we
 			 * must obey the peer.
+			 *
 			 * The wording in RFC2462 is confusing, and
 			 * there are multiple description text for
 			 * deprecated address handling - worse, they
 			 * are not exactly the same.  I believe 5.5.4
 			 * is the best one, so we follow 5.5.4.
 			 */
 			if (af == AF_INET6 && !ip6_use_deprecated) {
 				struct in6_ifaddr *ia6;
 				int s;
 				struct ifnet *rcvif = m_get_rcvif(m, &s);
 				if (rcvif == NULL)
 					goto dropwithreset; /* XXX */
 				if ((ia6 = in6ifa_ifpwithaddr(rcvif,
 				    &ip6->ip6_dst)) &&
 				    (ia6->ia6_flags & IN6_IFF_DEPRECATED)) {
 					tp = NULL;
 					m_put_rcvif(rcvif, &s);
 					goto dropwithreset;
+				}
 				m_put_rcvif(rcvif, &s);
+			}
 #endif
 			/*
 			 * LISTEN socket received a SYN from itself? This
 			 * can't possibly be valid; drop the packet.
 			 */
 			if (th->th_sport == th->th_dport) {
 				int eq = 0;
 				switch (af) {
 				case AF_INET:
 					eq = in_hosteq(ip->ip_src, ip->ip_dst);
 					break;
 #ifdef INET6
 				case AF_INET6:
 					eq = IN6_ARE_ADDR_EQUAL(&ip6->ip6_src,
 					    &ip6->ip6_dst);
 					break;
 #endif
+				}
 				if (eq) {
 					TCP_STATINC(TCP_STAT_BADSYN);
 					goto drop;
+				}
+			}
 			/*
 			 * SYN looks ok; create compressed TCP
 			 * state for it.
 			 */
 			if (so->so_qlen <= so->so_qlimit &&
 			    syn_cache_add(&src.sa, &dst.sa, th, off,
 			    so, m, optp, optlen, &opti))
 				m = NULL;
+		}
 		goto drop;
+	}
 after_listen:
 	/*
 	 * From here on, we're dealing with !LISTEN.
 	 */
 	KASSERT(tp->t_state != TCPS_LISTEN);
 	/*
 	 * Segment received on connection.
 	 * Reset idle time and keep-alive timer.
 	 */
 	tp->t_rcvtime = tcp_now;
 	if (TCPS_HAVEESTABLISHED(tp->t_state))
 		TCP_TIMER_ARM(tp, TCPT_KEEP, tp->t_keepidle);
 	/*
 	 * Process options.
 	 */
 #ifdef TCP_SIGNATURE
 	if (optp || (tp->t_flags & TF_SIGNATURE))
 #else
 	if (optp)
 #endif
 		if (tcp_dooptions(tp, optp, optlen, th, m, off, &opti) < 0)
 			goto drop;
 	if (TCP_SACK_ENABLED(tp)) {
 		tcp_del_sackholes(tp, th);
+	}
 	if (TCP_ECN_ALLOWED(tp)) {
 		if (tiflags & TH_CWR) {
 			tp->t_flags &= ~TF_ECN_SND_ECE;
+		}
 		switch (iptos & IPTOS_ECN_MASK) {
 		case IPTOS_ECN_CE:
 			tp->t_flags |= TF_ECN_SND_ECE;
 			TCP_STATINC(TCP_STAT_ECN_CE);
 			break;
 		case IPTOS_ECN_ECT0:
 			TCP_STATINC(TCP_STAT_ECN_ECT);
 			break;
 		case IPTOS_ECN_ECT1:
 			/* XXX: ignore for now -- rpaulo */
 			break;
+		}
 		/*
 		 * Congestion experienced.
 		 * Ignore if we are already trying to recover.
 		 */
 		if ((tiflags & TH_ECE) && SEQ_GEQ(tp->snd_una, tp->snd_recover))
 			tp->t_congctl->cong_exp(tp);
+	}
 	if (opti.ts_present && opti.ts_ecr) {
 		/*
 		 * Calculate the RTT from the returned time stamp and the
 		 * connection's time base.  If the time stamp is later than
 		 * the current time, or is extremely old, fall back to non-1323
 		 * RTT calculation.  Since ts_rtt is unsigned, we can test both
 		 * at the same time.
+		 *
 		 * Note that ts_rtt is in units of slow ticks (500
 		 * ms).  Since most earthbound RTTs are < 500 ms,
 		 * observed values will have large quantization noise.
 		 * Our smoothed RTT is then the fraction of observed
 		 * samples that are 1 tick instead of 0 (times 500
 		 * ms).
+		 *
 		 * ts_rtt is increased by 1 to denote a valid sample,
 		 * with 0 indicating an invalid measurement.  This
 		 * extra 1 must be removed when ts_rtt is used, or
 		 * else an erroneous extra 500 ms will result.
 		 */
 		ts_rtt = TCP_TIMESTAMP(tp) - opti.ts_ecr + 1;
 		if (ts_rtt > TCP_PAWS_IDLE)
 			ts_rtt = 0;
 	} else {
 		ts_rtt = 0;
+	}
 	/*
 	 * Fast path: check for the two common cases of a uni-directional
 	 * data transfer. If:
 	 *    o We are in the ESTABLISHED state, and
 	 *    o The packet has no control flags, and
 	 *    o The packet is in-sequence, and
 	 *    o The window didn't change, and
 	 *    o We are not retransmitting
 	 * It's a candidate.
+	 *
 	 * If the length (tlen) is zero and the ack moved forward, we're
 	 * the sender side of the transfer. Just free the data acked and
 	 * wake any higher level process that was blocked waiting for
 	 * space.
+	 *
 	 * If the length is non-zero and the ack didn't move, we're the
 	 * receiver side. If we're getting packets in-order (the reassembly
 	 * queue is empty), add the data to the socket buffer and note
 	 * that we need a delayed ack.
 	 */
 	if (tp->t_state == TCPS_ESTABLISHED &&
 	    (tiflags & (TH_SYN|TH_FIN|TH_RST|TH_URG|TH_ECE|TH_CWR|TH_ACK))
 	        == TH_ACK &&
 	    (!opti.ts_present || TSTMP_GEQ(opti.ts_val, tp->ts_recent)) &&
 	    th->th_seq == tp->rcv_nxt &&
 	    tiwin && tiwin == tp->snd_wnd &&
 	    tp->snd_nxt == tp->snd_max) {
 		/*
 		 * If last ACK falls within this segment's sequence numbers,
 		 * record the timestamp.
 		 * NOTE that the test is modified according to the latest
 		 * proposal of the tcplw@cray.com list (Braden 1993/04/26).
+		 *
 		 * note that we already know
 		 *	TSTMP_GEQ(opti.ts_val, tp->ts_recent)
 		 */
 		if (opti.ts_present && SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
 			tp->ts_recent_age = tcp_now;
 			tp->ts_recent = opti.ts_val;
+		}
 		if (tlen == 0) {
 			/* Ack prediction. */
 			if (SEQ_GT(th->th_ack, tp->snd_una) &&
 			    SEQ_LEQ(th->th_ack, tp->snd_max) &&
 			    tp->snd_cwnd >= tp->snd_wnd &&
 			    tp->t_partialacks < 0) {
 				/*
 				 * this is a pure ack for outstanding data.
 				 */
 				if (ts_rtt)
 					tcp_xmit_timer(tp, ts_rtt - 1);
 				else if (tp->t_rtttime &&
 				    SEQ_GT(th->th_ack, tp->t_rtseq))
 					tcp_xmit_timer(tp,
 					  tcp_now - tp->t_rtttime);
 				acked = th->th_ack - tp->snd_una;
 				tcps = TCP_STAT_GETREF();
 				tcps[TCP_STAT_PREDACK]++;
 				tcps[TCP_STAT_RCVACKPACK]++;
 				tcps[TCP_STAT_RCVACKBYTE] += acked;
 				TCP_STAT_PUTREF();
 				nd6_hint(tp);
 				if (acked > (tp->t_lastoff - tp->t_inoff))
 					tp->t_lastm = NULL;
 				sbdrop(&so->so_snd, acked);
 				tp->t_lastoff -= acked;
 				icmp_check(tp, th, acked);
 				tp->snd_una = th->th_ack;
 				tp->snd_fack = tp->snd_una;
 				if (SEQ_LT(tp->snd_high, tp->snd_una))
 					tp->snd_high = tp->snd_una;
 				/*
 				 * drag snd_wl2 along so only newer
 				 * ACKs can update the window size.
 				 * also avoids the state where snd_wl2
 				 * is eventually larger than th_ack and thus
 				 * blocking the window update mechanism and
 				 * the connection gets stuck for a loooong
 				 * time in the zero sized send window state.
+				 *
 				 * see PR/kern 55567
 				 */
 				tp->snd_wl2 = tp->snd_una;
 				m_freem(m);
 				/*
 				 * If all outstanding data are acked, stop
 				 * retransmit timer, otherwise restart timer
 				 * using current (possibly backed-off) value.
 				 * If process is waiting for space,
 				 * wakeup/selnotify/signal.  If data
 				 * are ready to send, let tcp_output
 				 * decide between more output or persist.
 				 */
 				if (tp->snd_una == tp->snd_max)
 					TCP_TIMER_DISARM(tp, TCPT_REXMT);
 				else if (TCP_TIMER_ISARMED(tp,
 				    TCPT_PERSIST) == 0)
 					TCP_TIMER_ARM(tp, TCPT_REXMT,
 					    tp->t_rxtcur);
 				sowwakeup(so);
 				if (so->so_snd.sb_cc) {
 					KERNEL_LOCK(1, NULL);
 					(void)tcp_output(tp);
 					KERNEL_UNLOCK_ONE(NULL);
+				}
 				if (tcp_saveti)
 					m_freem(tcp_saveti);
 				return;
+			}
 		} else if (th->th_ack == tp->snd_una &&
 		    TAILQ_FIRST(&tp->segq) == NULL &&
 		    tlen <= sbspace(&so->so_rcv)) {
 			int newsize = 0;
 			/*
 			 * this is a pure, in-sequence data packet
 			 * with nothing on the reassembly queue and
 			 * we have enough buffer space to take it.
 			 */
 			tp->rcv_nxt += tlen;
 			tcps = TCP_STAT_GETREF();
 			tcps[TCP_STAT_PREDDAT]++;
 			tcps[TCP_STAT_RCVPACK]++;
 			tcps[TCP_STAT_RCVBYTE] += tlen;
 			TCP_STAT_PUTREF();
 			nd6_hint(tp);
 		/*
 		 * Automatic sizing enables the performance of large buffers
 		 * and most of the efficiency of small ones by only allocating
 		 * space when it is needed.
+		 *
 		 * On the receive side the socket buffer memory is only rarely
 		 * used to any significant extent.  This allows us to be much
 		 * more aggressive in scaling the receive socket buffer.  For
 		 * the case that the buffer space is actually used to a large
 		 * extent and we run out of kernel memory we can simply drop
 		 * the new segments; TCP on the sender will just retransmit it
 		 * later.  Setting the buffer size too big may only consume too
 		 * much kernel memory if the application doesn't read() from
 		 * the socket or packet loss or reordering makes use of the
 		 * reassembly queue.
+		 *
 		 * The criteria to step up the receive buffer one notch are:
 		 *  1. the number of bytes received during the time it takes
 		 *     one timestamp to be reflected back to us (the RTT);
 		 *  2. received bytes per RTT is within seven eighth of the
 		 *     current socket buffer size;
 		 *  3. receive buffer size has not hit maximal automatic size;
+		 *
 		 * This algorithm does one step per RTT at most and only if
 		 * we receive a bulk stream w/o packet losses or reorderings.
 		 * Shrinking the buffer during idle times is not necessary as
 		 * it doesn't consume any memory when idle.
+		 *
 		 * TODO: Only step up if the application is actually serving
 		 * the buffer to better manage the socket buffer resources.
 		 */
 			if (tcp_do_autorcvbuf &&
 			    opti.ts_ecr &&
 			    (so->so_rcv.sb_flags & SB_AUTOSIZE)) {
 				if (opti.ts_ecr > tp->rfbuf_ts &&
 				    opti.ts_ecr - tp->rfbuf_ts < PR_SLOWHZ) {
 					if (tp->rfbuf_cnt >
 					    (so->so_rcv.sb_hiwat / 8 * 7) &&
 					    so->so_rcv.sb_hiwat <
 					    tcp_autorcvbuf_max) {
 						newsize =
 						    uimin(so->so_rcv.sb_hiwat +
 						    tcp_autorcvbuf_inc,
 						    tcp_autorcvbuf_max);
+					}
 					/* Start over with next RTT. */
 					tp->rfbuf_ts = 0;
 					tp->rfbuf_cnt = 0;
 				} else
 					tp->rfbuf_cnt += tlen;	/* add up */
+			}
 			/*
 			 * Drop TCP, IP headers and TCP options then add data
 			 * to socket buffer.
 			 */
 			if (so->so_state & SS_CANTRCVMORE) {
 				m_freem(m);
 			} else {
 				/*
 				 * Set new socket buffer size.
 				 * Give up when limit is reached.
 				 */
 				if (newsize)
 					if (!sbreserve(&so->so_rcv,
 					    newsize, so))
 						so->so_rcv.sb_flags &= ~SB_AUTOSIZE;
 				m_adj(m, off + thlen);
 				sbappendstream(&so->so_rcv, m);
+			}
 			sorwakeup(so);
 			tcp_setup_ack(tp, th);
 			if (tp->t_flags & TF_ACKNOW) {
 				KERNEL_LOCK(1, NULL);
 				(void)tcp_output(tp);
 				KERNEL_UNLOCK_ONE(NULL);
+			}
 			if (tcp_saveti)
 				m_freem(tcp_saveti);
 			return;
+		}
+	}
 	/*
 	 * Compute mbuf offset to TCP data segment.
 	 */
 	hdroptlen = off + thlen;
 	/*
 	 * Calculate amount of space in receive window. Receive window is
 	 * amount of space in rcv queue, but not less than advertised
 	 * window.
 	 */
+	{
 		int win;
 		win = sbspace(&so->so_rcv);
 		if (win < 0)
 			win = 0;
 		tp->rcv_wnd = imax(win, (int)(tp->rcv_adv - tp->rcv_nxt));
+	}
 	/* Reset receive buffer auto scaling when not in bulk receive mode. */
 	tp->rfbuf_ts = 0;
 	tp->rfbuf_cnt = 0;
 	switch (tp->t_state) {
 	/*
 	 * If the state is SYN_SENT:
 	 *	if seg contains an ACK, but not for our SYN, drop the input.
 	 *	if seg contains a RST, then drop the connection.
 	 *	if seg does not contain SYN, then drop it.
 	 * Otherwise this is an acceptable SYN segment
 	 *	initialize tp->rcv_nxt and tp->irs
 	 *	if seg contains ack then advance tp->snd_una
 	 *	if seg contains a ECE and ECN support is enabled, the stream
 	 *	    is ECN capable.
 	 *	if SYN has been acked change to ESTABLISHED else SYN_RCVD state
 	 *	arrange for segment to be acked (eventually)
 	 *	continue processing rest of data/controls, beginning with URG
 	 */
 	case TCPS_SYN_SENT:
 		if ((tiflags & TH_ACK) &&
 		    (SEQ_LEQ(th->th_ack, tp->iss) ||
 		     SEQ_GT(th->th_ack, tp->snd_max)))
 			goto dropwithreset;
 		if (tiflags & TH_RST) {
 			if (tiflags & TH_ACK)
 				tp = tcp_drop(tp, ECONNREFUSED);
 			goto drop;
+		}
 		if ((tiflags & TH_SYN) == 0)
 			goto drop;
 		if (tiflags & TH_ACK) {
 			tp->snd_una = th->th_ack;
 			if (SEQ_LT(tp->snd_nxt, tp->snd_una))
 				tp->snd_nxt = tp->snd_una;
 			if (SEQ_LT(tp->snd_high, tp->snd_una))
 				tp->snd_high = tp->snd_una;
 			TCP_TIMER_DISARM(tp, TCPT_REXMT);
 			if ((tiflags & TH_ECE) && tcp_do_ecn) {
 				tp->t_flags |= TF_ECN_PERMIT;
 				TCP_STATINC(TCP_STAT_ECN_SHS);
+			}
+		}
 		tp->irs = th->th_seq;
 		tcp_rcvseqinit(tp);
 		tp->t_flags |= TF_ACKNOW;
 		tcp_mss_from_peer(tp, opti.maxseg);
 		/*
 		 * Initialize the initial congestion window.  If we
 		 * had to retransmit the SYN, we must initialize cwnd
 		 * to 1 segment (i.e. the Loss Window).
 		 */
 		if (tp->t_flags & TF_SYN_REXMT)
 			tp->snd_cwnd = tp->t_peermss;
 		else {
 			int ss = tcp_init_win;
 			if (inp != NULL && in_localaddr(inp->inp_faddr))
 				ss = tcp_init_win_local;
 #ifdef INET6
 			if (in6p != NULL && in6_localaddr(&in6p->in6p_faddr))
 				ss = tcp_init_win_local;
 #endif
 			tp->snd_cwnd = TCP_INITIAL_WINDOW(ss, tp->t_peermss);
+		}
 		tcp_rmx_rtt(tp);
 		if (tiflags & TH_ACK) {
 			TCP_STATINC(TCP_STAT_CONNECTS);
 			/*
 			 * move tcp_established before soisconnected
 			 * because upcall handler can drive tcp_output
 			 * functionality.
 			 * XXX we might call soisconnected at the end of
 			 * all processing
 			 */
 			tcp_established(tp);
 			soisconnected(so);
 			/* Do window scaling on this connection? */
 			if ((tp->t_flags & (TF_RCVD_SCALE|TF_REQ_SCALE)) ==
 			    (TF_RCVD_SCALE|TF_REQ_SCALE)) {
 				tp->snd_scale = tp->requested_s_scale;
 				tp->rcv_scale = tp->request_r_scale;
+			}
 			TCP_REASS_LOCK(tp);
 			(void)tcp_reass(tp, NULL, NULL, tlen);
 			/*
 			 * if we didn't have to retransmit the SYN,
 			 * use its rtt as our initial srtt & rtt var.
 			 */
 			if (tp->t_rtttime)
 				tcp_xmit_timer(tp, tcp_now - tp->t_rtttime);
 		} else {
 			tp->t_state = TCPS_SYN_RECEIVED;
+		}
 		/*
 		 * Advance th->th_seq to correspond to first data byte.
 		 * If data, trim to stay within window,
 		 * dropping FIN if necessary.
 		 */
 		th->th_seq++;
 		if (tlen > tp->rcv_wnd) {
 			todrop = tlen - tp->rcv_wnd;
 			m_adj(m, -todrop);
 			tlen = tp->rcv_wnd;
 			tiflags &= ~TH_FIN;
 			tcps = TCP_STAT_GETREF();
 			tcps[TCP_STAT_RCVPACKAFTERWIN]++;
 			tcps[TCP_STAT_RCVBYTEAFTERWIN] += todrop;
 			TCP_STAT_PUTREF();
+		}
 		tp->snd_wl1 = th->th_seq - 1;
 		tp->rcv_up = th->th_seq;
 		goto step6;
 	/*
 	 * If the state is SYN_RECEIVED:
 	 *	If seg contains an ACK, but not for our SYN, drop the input
 	 *	and generate an RST.  See page 36, rfc793
 	 */
 	case TCPS_SYN_RECEIVED:
 		if ((tiflags & TH_ACK) &&
 		    (SEQ_LEQ(th->th_ack, tp->iss) ||
 		     SEQ_GT(th->th_ack, tp->snd_max)))
 			goto dropwithreset;
 		break;
+	}
 	/*
 	 * From here on, we're dealing with !LISTEN and !SYN_SENT.
 	 */
 	KASSERT(tp->t_state != TCPS_LISTEN &&
 	    tp->t_state != TCPS_SYN_SENT);
 	/*
 	 * RFC1323 PAWS: if we have a timestamp reply on this segment and
 	 * it's less than ts_recent, drop it.
 	 */
 	if (opti.ts_present && (tiflags & TH_RST) == 0 && tp->ts_recent &&
 	    TSTMP_LT(opti.ts_val, tp->ts_recent)) {
 		/* Check to see if ts_recent is over 24 days old.  */
 		if (tcp_now - tp->ts_recent_age > TCP_PAWS_IDLE) {
 			/*
 			 * Invalidate ts_recent.  If this segment updates
 			 * ts_recent, the age will be reset later and ts_recent
 			 * will get a valid value.  If it does not, setting
 			 * ts_recent to zero will at least satisfy the
 			 * requirement that zero be placed in the timestamp
 			 * echo reply when ts_recent isn't valid.  The
 			 * age isn't reset until we get a valid ts_recent
 			 * because we don't want out-of-order segments to be
 			 * dropped when ts_recent is old.
 			 */
 			tp->ts_recent = 0;
 		} else {
 			tcps = TCP_STAT_GETREF();
 			tcps[TCP_STAT_RCVDUPPACK]++;
 			tcps[TCP_STAT_RCVDUPBYTE] += tlen;
 			tcps[TCP_STAT_PAWSDROP]++;
 			TCP_STAT_PUTREF();
 			tcp_new_dsack(tp, th->th_seq, tlen);
 			goto dropafterack;
+		}
+	}
 	/*
 	 * Check that at least some bytes of the segment are within the
 	 * receive window. If segment begins before rcv_nxt, drop leading
 	 * data (and SYN); if nothing left, just ack.
 	 */
 	todrop = tp->rcv_nxt - th->th_seq;
 	dupseg = false;
 	if (todrop > 0) {
 		if (tiflags & TH_SYN) {
 			tiflags &= ~TH_SYN;
 			th->th_seq++;
 			tcp_urp_drop(th, 1, &tiflags);
 			todrop--;
+		}
 		if (todrop > tlen ||
 		    (todrop == tlen && (tiflags & TH_FIN) == 0)) {
 			/*
 			 * Any valid FIN or RST must be to the left of the
 			 * window.  At this point the FIN or RST must be a
 			 * duplicate or out of sequence; drop it.
 			 */
 			if (tiflags & TH_RST)
 				goto drop;
 			tiflags &= ~(TH_FIN|TH_RST);
 			/*
 			 * Send an ACK to resynchronize and drop any data.
 			 * But keep on processing for RST or ACK.
 			 */
 			tp->t_flags |= TF_ACKNOW;
 			todrop = tlen;
 			dupseg = true;
 			tcps = TCP_STAT_GETREF();
 			tcps[TCP_STAT_RCVDUPPACK]++;
 			tcps[TCP_STAT_RCVDUPBYTE] += todrop;
 			TCP_STAT_PUTREF();
 		} else if ((tiflags & TH_RST) && th->th_seq != tp->rcv_nxt) {
 			/*
 			 * Test for reset before adjusting the sequence
 			 * number for overlapping data.
 			 */
 			goto dropafterack_ratelim;
 		} else {
 			tcps = TCP_STAT_GETREF();
 			tcps[TCP_STAT_RCVPARTDUPPACK]++;
 			tcps[TCP_STAT_RCVPARTDUPBYTE] += todrop;
 			TCP_STAT_PUTREF();
+		}
 		tcp_new_dsack(tp, th->th_seq, todrop);
 		hdroptlen += todrop;	/* drop from head afterwards (m_adj) */
 		th->th_seq += todrop;
 		tlen -= todrop;
 		tcp_urp_drop(th, todrop, &tiflags);
+	}
 	/*
 	 * If new data is received on a connection after the user processes
 	 * are gone, then RST the other end.
 	 */
 	if ((so->so_state & SS_NOFDREF) &&
 	    tp->t_state > TCPS_CLOSE_WAIT && tlen) {
 		tp = tcp_close(tp);
 		TCP_STATINC(TCP_STAT_RCVAFTERCLOSE);
 		goto dropwithreset;
+	}
 	/*
 	 * If the segment ends after the window, drop trailing data (and
 	 * PUSH and FIN); if nothing left, just ACK.
 	 */
 	todrop = (th->th_seq + tlen) - (tp->rcv_nxt + tp->rcv_wnd);
 	if (todrop > 0) {
 		TCP_STATINC(TCP_STAT_RCVPACKAFTERWIN);
 		if (todrop >= tlen) {
 			/*
 			 * The segment actually starts after the window.
 			 * th->th_seq + tlen - tp->rcv_nxt - tp->rcv_wnd >= tlen
 			 * th->th_seq - tp->rcv_nxt - tp->rcv_wnd >= 0
 			 * th->th_seq >= tp->rcv_nxt + tp->rcv_wnd
 			 */
 			TCP_STATADD(TCP_STAT_RCVBYTEAFTERWIN, tlen);
 			/*
 			 * If a new connection request is received while in
 			 * TIME_WAIT, drop the old connection and start over
 			 * if the sequence numbers are above the previous
 			 * ones.
+			 *
 			 * NOTE: We need to put the header fields back into
 			 * network order.
 			 */
 			if ((tiflags & TH_SYN) &&
 			    tp->t_state == TCPS_TIME_WAIT &&
 			    SEQ_GT(th->th_seq, tp->rcv_nxt)) {
 				tp = tcp_close(tp);
 				tcp_fields_to_net(th);
 				m_freem(tcp_saveti);
 				tcp_saveti = NULL;
 				goto findpcb;
+			}
 			/*
 			 * If window is closed can only take segments at
 			 * window edge, and have to drop data and PUSH from
 			 * incoming segments.  Continue processing, but
 			 * remember to ack.  Otherwise, drop segment
 			 * and (if not RST) ack.
 			 */
 			if (tp->rcv_wnd == 0 && th->th_seq == tp->rcv_nxt) {
 				KASSERT(todrop == tlen);
 				tp->t_flags |= TF_ACKNOW;
 				TCP_STATINC(TCP_STAT_RCVWINPROBE);
 			} else {
 				goto dropafterack;
+			}
 		} else {
 			TCP_STATADD(TCP_STAT_RCVBYTEAFTERWIN, todrop);
+		}
 		m_adj(m, -todrop);
 		tlen -= todrop;
 		tiflags &= ~(TH_PUSH|TH_FIN);
+	}
 	/*
 	 * If last ACK falls within this segment's sequence numbers,
 	 *  record the timestamp.
 	 * NOTE:
 	 * 1) That the test incorporates suggestions from the latest
 	 *    proposal of the tcplw@cray.com list (Braden 1993/04/26).
 	 * 2) That updating only on newer timestamps interferes with
 	 *    our earlier PAWS tests, so this check should be solely
 	 *    predicated on the sequence space of this segment.
 	 * 3) That we modify the segment boundary check to be
 	 *        Last.ACK.Sent <= SEG.SEQ + SEG.Len
 	 *    instead of RFC1323's
 	 *        Last.ACK.Sent < SEG.SEQ + SEG.Len,
 	 *    This modified check allows us to overcome RFC1323's
 	 *    limitations as described in Stevens TCP/IP Illustrated
 	 *    Vol. 2 p.869. In such cases, we can still calculate the
 	 *    RTT correctly when RCV.NXT == Last.ACK.Sent.
 	 */
 	if (opti.ts_present &&
 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
 	         ((tiflags & (TH_SYN|TH_FIN)) != 0))) {
 		tp->ts_recent_age = tcp_now;
 		tp->ts_recent = opti.ts_val;
+	}
 	/*
 	 * If the RST bit is set examine the state:
 	 *    RECEIVED state:
 	 *        If passive open, return to LISTEN state.
 	 *        If active open, inform user that connection was refused.
 	 *    ESTABLISHED, FIN_WAIT_1, FIN_WAIT2, CLOSE_WAIT states:
 	 *        Inform user that connection was reset, and close tcb.
 	 *    CLOSING, LAST_ACK, TIME_WAIT states:
 	 *        Close the tcb.
 	 */
 	if (tiflags & TH_RST) {
 		if (th->th_seq != tp->rcv_nxt)
 			goto dropafterack_ratelim;
 		switch (tp->t_state) {
 		case TCPS_SYN_RECEIVED:
 			so->so_error = ECONNREFUSED;
 			goto close;
 		case TCPS_ESTABLISHED:
 		case TCPS_FIN_WAIT_1:
 		case TCPS_FIN_WAIT_2:
 		case TCPS_CLOSE_WAIT:
 			so->so_error = ECONNRESET;
 		close:
 			tp->t_state = TCPS_CLOSED;
 			TCP_STATINC(TCP_STAT_DROPS);
 			tp = tcp_close(tp);
 			goto drop;
 		case TCPS_CLOSING:
 		case TCPS_LAST_ACK:
 		case TCPS_TIME_WAIT:
 			tp = tcp_close(tp);
 			goto drop;
+		}
+	}
 	/*
 	 * Since we've covered the SYN-SENT and SYN-RECEIVED states above
 	 * we must be in a synchronized state.  RFC793 states (under Reset
 	 * Generation) that any unacceptable segment (an out-of-order SYN
 	 * qualifies) received in a synchronized state must elicit only an
 	 * empty acknowledgment segment ... and the connection remains in
 	 * the same state.
 	 */
 	if (tiflags & TH_SYN) {
 		if (tp->rcv_nxt == th->th_seq) {
 			tcp_respond(tp, m, m, th, (tcp_seq)0, th->th_ack - 1,
 			    TH_ACK);
 			if (tcp_saveti)
 				m_freem(tcp_saveti);
 			return;
+		}
 		goto dropafterack_ratelim;
+	}
 	/*
 	 * If the ACK bit is off we drop the segment and return.
 	 */
 	if ((tiflags & TH_ACK) == 0) {
 		if (tp->t_flags & TF_ACKNOW)
 			goto dropafterack;
 		goto drop;
+	}
 	/*
 	 * From here on, we're doing ACK processing.
 	 */
 	switch (tp->t_state) {
 	/*
 	 * In SYN_RECEIVED state if the ack ACKs our SYN then enter
 	 * ESTABLISHED state and continue processing, otherwise
 	 * send an RST.
 	 */
 	case TCPS_SYN_RECEIVED:
 		if (SEQ_GT(tp->snd_una, th->th_ack) ||
 		    SEQ_GT(th->th_ack, tp->snd_max))
 			goto dropwithreset;
 		TCP_STATINC(TCP_STAT_CONNECTS);
 		soisconnected(so);
 		tcp_established(tp);
 		/* Do window scaling? */
 		if ((tp->t_flags & (TF_RCVD_SCALE|TF_REQ_SCALE)) ==
 		    (TF_RCVD_SCALE|TF_REQ_SCALE)) {
 			tp->snd_scale = tp->requested_s_scale;
 			tp->rcv_scale = tp->request_r_scale;
+		}
 		TCP_REASS_LOCK(tp);
 		(void)tcp_reass(tp, NULL, NULL, tlen);
 		tp->snd_wl1 = th->th_seq - 1;
 		/* FALLTHROUGH */
 	/*
 	 * In ESTABLISHED state: drop duplicate ACKs; ACK out of range
 	 * ACKs.  If the ack is in the range
 	 *	tp->snd_una < th->th_ack <= tp->snd_max
 	 * then advance tp->snd_una to th->th_ack and drop
 	 * data from the retransmission queue.  If this ACK reflects
 	 * more up to date window information we update our window information.
 	 */
 	case TCPS_ESTABLISHED:
 	case TCPS_FIN_WAIT_1:
 	case TCPS_FIN_WAIT_2:
 	case TCPS_CLOSE_WAIT:
 	case TCPS_CLOSING:
 	case TCPS_LAST_ACK:
 	case TCPS_TIME_WAIT:
 		if (SEQ_LEQ(th->th_ack, tp->snd_una)) {
 			if (tlen == 0 && !dupseg && tiwin == tp->snd_wnd) {
 				TCP_STATINC(TCP_STAT_RCVDUPACK);
 				/*
 				 * If we have outstanding data (other than
 				 * a window probe), this is a completely
 				 * duplicate ack (ie, window info didn't
 				 * change), the ack is the biggest we've
 				 * seen and we've seen exactly our rexmt
 				 * threshhold of them, assume a packet
 				 * has been dropped and retransmit it.
 				 * Kludge snd_nxt & the congestion
 				 * window so we send only this one
 				 * packet.
 				 */
 				if (TCP_TIMER_ISARMED(tp, TCPT_REXMT) == 0 ||
 				    th->th_ack != tp->snd_una)
 					tp->t_dupacks = 0;
 				else if (tp->t_partialacks < 0 &&
 				    (++tp->t_dupacks == tcprexmtthresh ||
 				     TCP_FACK_FASTRECOV(tp))) {
 					/*
 					 * Do the fast retransmit, and adjust
 					 * congestion control paramenters.
 					 */
 					if (tp->t_congctl->fast_retransmit(tp, th)) {
 						/* False fast retransmit */
 						break;
+					}
 					goto drop;
 				} else if (tp->t_dupacks > tcprexmtthresh) {
 					tp->snd_cwnd += tp->t_segsz;
 					KERNEL_LOCK(1, NULL);
 					(void)tcp_output(tp);
 					KERNEL_UNLOCK_ONE(NULL);
 					goto drop;
+				}
 			} else {
 				/*
 				 * If the ack appears to be very old, only
 				 * allow data that is in-sequence.  This
 				 * makes it somewhat more difficult to insert
 				 * forged data by guessing sequence numbers.
 				 * Sent an ack to try to update the send
 				 * sequence number on the other side.
 				 */
 				if (tlen && th->th_seq != tp->rcv_nxt &&
 				    SEQ_LT(th->th_ack,
 				    tp->snd_una - tp->max_sndwnd))
 					goto dropafterack;
+			}
 			break;
+		}
 		/*
 		 * If the congestion window was inflated to account
 		 * for the other side's cached packets, retract it.
 		 */
 		tp->t_congctl->fast_retransmit_newack(tp, th);
 		if (SEQ_GT(th->th_ack, tp->snd_max)) {
 			TCP_STATINC(TCP_STAT_RCVACKTOOMUCH);
 			goto dropafterack;
+		}
 		acked = th->th_ack - tp->snd_una;
 		tcps = TCP_STAT_GETREF();
 		tcps[TCP_STAT_RCVACKPACK]++;
 		tcps[TCP_STAT_RCVACKBYTE] += acked;
 		TCP_STAT_PUTREF();
 		/*
 		 * If we have a timestamp reply, update smoothed
 		 * round trip time.  If no timestamp is present but
 		 * transmit timer is running and timed sequence
 		 * number was acked, update smoothed round trip time.
 		 * Since we now have an rtt measurement, cancel the
 		 * timer backoff (cf., Phil Karn's retransmit alg.).
 		 * Recompute the initial retransmit timer.
 		 */
 		if (ts_rtt)
 			tcp_xmit_timer(tp, ts_rtt - 1);
 		else if (tp->t_rtttime && SEQ_GT(th->th_ack, tp->t_rtseq))
 			tcp_xmit_timer(tp, tcp_now - tp->t_rtttime);
 		/*
 		 * If all outstanding data is acked, stop retransmit
 		 * timer and remember to restart (more output or persist).
 		 * If there is more data to be acked, restart retransmit
 		 * timer, using current (possibly backed-off) value.
 		 */
 		if (th->th_ack == tp->snd_max) {
 			TCP_TIMER_DISARM(tp, TCPT_REXMT);
 			needoutput = 1;
 		} else if (TCP_TIMER_ISARMED(tp, TCPT_PERSIST) == 0)
 			TCP_TIMER_ARM(tp, TCPT_REXMT, tp->t_rxtcur);
 		/*
 		 * New data has been acked, adjust the congestion window.
 		 */
 		tp->t_congctl->newack(tp, th);
 		nd6_hint(tp);
 		if (acked > so->so_snd.sb_cc) {
 			tp->snd_wnd -= so->so_snd.sb_cc;
 			sbdrop(&so->so_snd, (int)so->so_snd.sb_cc);
 			ourfinisacked = 1;
 		} else {
 			if (acked > (tp->t_lastoff - tp->t_inoff))
 				tp->t_lastm = NULL;
 			sbdrop(&so->so_snd, acked);
 			tp->t_lastoff -= acked;
 			if (tp->snd_wnd > acked)
 				tp->snd_wnd -= acked;
 			else
 				tp->snd_wnd = 0;
 			ourfinisacked = 0;
+		}
 		sowwakeup(so);
 		icmp_check(tp, th, acked);
 		tp->snd_una = th->th_ack;
 		if (SEQ_GT(tp->snd_una, tp->snd_fack))
 			tp->snd_fack = tp->snd_una;
 		if (SEQ_LT(tp->snd_nxt, tp->snd_una))
 			tp->snd_nxt = tp->snd_una;
 		if (SEQ_LT(tp->snd_high, tp->snd_una))
 			tp->snd_high = tp->snd_una;
 		switch (tp->t_state) {
 		/*
 		 * In FIN_WAIT_1 STATE in addition to the processing
 		 * for the ESTABLISHED state if our FIN is now acknowledged
 		 * then enter FIN_WAIT_2.
 		 */
 		case TCPS_FIN_WAIT_1:
 			if (ourfinisacked) {
 				/*
 				 * If we can't receive any more
 				 * data, then closing user can proceed.
 				 * Starting the timer is contrary to the
 				 * specification, but if we don't get a FIN
 				 * we'll hang forever.
 				 */
 				if (so->so_state & SS_CANTRCVMORE) {
 					soisdisconnected(so);
 					if (tp->t_maxidle > 0)
 						TCP_TIMER_ARM(tp, TCPT_2MSL,
 						    tp->t_maxidle);
+				}
 				tp->t_state = TCPS_FIN_WAIT_2;
+			}
 			break;
 	 	/*
 		 * In CLOSING STATE in addition to the processing for
 		 * the ESTABLISHED state if the ACK acknowledges our FIN
 		 * then enter the TIME-WAIT state, otherwise ignore
 		 * the segment.
 		 */
 		case TCPS_CLOSING:
 			if (ourfinisacked) {
 				tp->t_state = TCPS_TIME_WAIT;
 				tcp_canceltimers(tp);
 				TCP_TIMER_ARM(tp, TCPT_2MSL, 2 * tp->t_msl);
 				soisdisconnected(so);
+			}
 			break;
 		/*
 		 * In LAST_ACK, we may still be waiting for data to drain
 		 * and/or to be acked, as well as for the ack of our FIN.
 		 * If our FIN is now acknowledged, delete the TCB,
 		 * enter the closed state and return.
 		 */
 		case TCPS_LAST_ACK:
 			if (ourfinisacked) {
 				tp = tcp_close(tp);
 				goto drop;
+			}
 			break;
 		/*
 		 * In TIME_WAIT state the only thing that should arrive
 		 * is a retransmission of the remote FIN.  Acknowledge
 		 * it and restart the finack timer.
 		 */
 		case TCPS_TIME_WAIT:
 			TCP_TIMER_ARM(tp, TCPT_2MSL, 2 * tp->t_msl);
 			goto dropafterack;
+		}
+	}
 step6:
 	/*
 	 * Update window information.
 	 * Don't look at window if no ACK: TAC's send garbage on first SYN.
 	 */
 	if ((tiflags & TH_ACK) && (SEQ_LT(tp->snd_wl1, th->th_seq) ||
 	    (tp->snd_wl1 == th->th_seq && (SEQ_LT(tp->snd_wl2, th->th_ack) ||
 	    (tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd))))) {
 		/* keep track of pure window updates */
 		if (tlen == 0 &&
 		    tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd)
 			TCP_STATINC(TCP_STAT_RCVWINUPD);
 		tp->snd_wnd = tiwin;
 		tp->snd_wl1 = th->th_seq;
 		tp->snd_wl2 = th->th_ack;
 		if (tp->snd_wnd > tp->max_sndwnd)
 			tp->max_sndwnd = tp->snd_wnd;
 		needoutput = 1;
+	}
 	/*
 	 * Process segments with URG.
 	 */
 	if ((tiflags & TH_URG) && th->th_urp &&
 	    TCPS_HAVERCVDFIN(tp->t_state) == 0) {
 		/*
 		 * This is a kludge, but if we receive and accept
 		 * random urgent pointers, we'll crash in
 		 * soreceive.  It's hard to imagine someone
 		 * actually wanting to send this much urgent data.
 		 */
 		if (th->th_urp + so->so_rcv.sb_cc > sb_max) {
 			th->th_urp = 0;			/* XXX */
 			tiflags &= ~TH_URG;		/* XXX */
 			goto dodata;			/* XXX */
+		}
 		/*
 		 * If this segment advances the known urgent pointer,
 		 * then mark the data stream.  This should not happen
 		 * in CLOSE_WAIT, CLOSING, LAST_ACK or TIME_WAIT STATES since
 		 * a FIN has been received from the remote side.
 		 * In these states we ignore the URG.
+		 *
 		 * According to RFC961 (Assigned Protocols),
 		 * the urgent pointer points to the last octet
 		 * of urgent data.  We continue, however,
 		 * to consider it to indicate the first octet
 		 * of data past the urgent section as the original
 		 * spec states (in one of two places).
 		 */
 		if (SEQ_GT(th->th_seq+th->th_urp, tp->rcv_up)) {
 			tp->rcv_up = th->th_seq + th->th_urp;
 			so->so_oobmark = so->so_rcv.sb_cc +
 			    (tp->rcv_up - tp->rcv_nxt) - 1;
 			if (so->so_oobmark == 0)
 				so->so_state |= SS_RCVATMARK;
 			sohasoutofband(so);
 			tp->t_oobflags &= ~(TCPOOB_HAVEDATA | TCPOOB_HADDATA);
+		}
 		/*
 		 * Remove out of band data so doesn't get presented to user.
 		 * This can happen independent of advancing the URG pointer,
 		 * but if two URG's are pending at once, some out-of-band
 		 * data may creep in... ick.
 		 */
 		if (th->th_urp <= (u_int16_t)tlen &&
 		    (so->so_options & SO_OOBINLINE) == 0)
 			tcp_pulloutofband(so, th, m, hdroptlen);
 	} else {
 		/*
 		 * If no out of band data is expected,
 		 * pull receive urgent pointer along
 		 * with the receive window.
 		 */
 		if (SEQ_GT(tp->rcv_nxt, tp->rcv_up))
 			tp->rcv_up = tp->rcv_nxt;
+	}
 dodata:
 	/*
 	 * Process the segment text, merging it into the TCP sequencing queue,
 	 * and arranging for acknowledgement of receipt if necessary.
 	 * This process logically involves adjusting tp->rcv_wnd as data
 	 * is presented to the user (this happens in tcp_usrreq.c,
 	 * tcp_rcvd()).  If a FIN has already been received on this
 	 * connection then we just ignore the text.
 	 */
 	if ((tlen || (tiflags & TH_FIN)) &&
 	    TCPS_HAVERCVDFIN(tp->t_state) == 0) {
 		/*
 		 * Handle the common case:
 		 *  o Segment is the next to be received, and
 		 *  o The queue is empty, and
 		 *  o The connection is established
 		 * In this case, we avoid calling tcp_reass.
+		 *
 		 * tcp_setup_ack: set DELACK for segments received in order,
 		 * but ack immediately when segments are out of order (so that
 		 * fast retransmit can work).
 		 */
 		TCP_REASS_LOCK(tp);
 		if (th->th_seq == tp->rcv_nxt &&
 		    TAILQ_FIRST(&tp->segq) == NULL &&
 		    tp->t_state == TCPS_ESTABLISHED) {
 			tcp_setup_ack(tp, th);
 			tp->rcv_nxt += tlen;
 			tiflags = th->th_flags & TH_FIN;
 			tcps = TCP_STAT_GETREF();
 			tcps[TCP_STAT_RCVPACK]++;
 			tcps[TCP_STAT_RCVBYTE] += tlen;
 			TCP_STAT_PUTREF();
 			nd6_hint(tp);
 			if (so->so_state & SS_CANTRCVMORE) {
 				m_freem(m);
 			} else {
 				m_adj(m, hdroptlen);
 				sbappendstream(&(so)->so_rcv, m);
+			}
 			TCP_REASS_UNLOCK(tp);
 			sorwakeup(so);
 		} else {
 			m_adj(m, hdroptlen);
 			tiflags = tcp_reass(tp, th, m, tlen);
 			tp->t_flags |= TF_ACKNOW;
+		}
 		/*
 		 * Note the amount of data that peer has sent into
 		 * our window, in order to estimate the sender's
 		 * buffer size.
 		 */
 		len = so->so_rcv.sb_hiwat - (tp->rcv_adv - tp->rcv_nxt);
 	} else {
 		m_freem(m);
 		m = NULL;
 		tiflags &= ~TH_FIN;
+	}
 	/*
 	 * If FIN is received ACK the FIN and let the user know
 	 * that the connection is closing.  Ignore a FIN received before
 	 * the connection is fully established.
 	 */
 	if ((tiflags & TH_FIN) && TCPS_HAVEESTABLISHED(tp->t_state)) {
 		if (TCPS_HAVERCVDFIN(tp->t_state) == 0) {
 			socantrcvmore(so);
 			tp->t_flags |= TF_ACKNOW;
 			tp->rcv_nxt++;
+		}
 		switch (tp->t_state) {
 	 	/*
 		 * In ESTABLISHED STATE enter the CLOSE_WAIT state.
 		 */
 		case TCPS_ESTABLISHED:
 			tp->t_state = TCPS_CLOSE_WAIT;
 			break;
 	 	/*
 		 * If still in FIN_WAIT_1 STATE FIN has not been acked so
 		 * enter the CLOSING state.
 		 */
 		case TCPS_FIN_WAIT_1:
 			tp->t_state = TCPS_CLOSING;
 			break;
 	 	/*
 		 * In FIN_WAIT_2 state enter the TIME_WAIT state,
 		 * starting the time-wait timer, turning off the other
 		 * standard timers.
 		 */
 		case TCPS_FIN_WAIT_2:
 			tp->t_state = TCPS_TIME_WAIT;
 			tcp_canceltimers(tp);
 			TCP_TIMER_ARM(tp, TCPT_2MSL, 2 * tp->t_msl);
 			soisdisconnected(so);
 			break;
 		/*
 		 * In TIME_WAIT state restart the 2 MSL time_wait timer.
 		 */
 		case TCPS_TIME_WAIT:
 			TCP_TIMER_ARM(tp, TCPT_2MSL, 2 * tp->t_msl);
 			break;
+		}
+	}
 #ifdef TCP_DEBUG
 	if (so->so_options & SO_DEBUG)
 		tcp_trace(TA_INPUT, ostate, tp, tcp_saveti, 0);
 #endif
 	/*
 	 * Return any desired output.
 	 */
 	if (needoutput || (tp->t_flags & TF_ACKNOW)) {
 		KERNEL_LOCK(1, NULL);
 		(void)tcp_output(tp);
 		KERNEL_UNLOCK_ONE(NULL);
+	}
 	if (tcp_saveti)
 		m_freem(tcp_saveti);
 	if (tp->t_state == TCPS_TIME_WAIT
 	    && (so->so_state & SS_NOFDREF)
 	    && (tp->t_inpcb || af != AF_INET)
 	    && (tp->t_in6pcb || af != AF_INET6)
 	    && ((af == AF_INET ? tcp4_vtw_enable : tcp6_vtw_enable) & 1) != 0
 	    && TAILQ_EMPTY(&tp->segq)
 	    && vtw_add(af, tp)) {
+		;
+	}
 	return;
 badsyn:
 	/*
 	 * Received a bad SYN.  Increment counters and dropwithreset.
 	 */
 	TCP_STATINC(TCP_STAT_BADSYN);
 	tp = NULL;
 	goto dropwithreset;
 dropafterack:
 	/*
 	 * Generate an ACK dropping incoming segment if it occupies
 	 * sequence space, where the ACK reflects our state.
 	 */
 	if (tiflags & TH_RST)
 		goto drop;
 	goto dropafterack2;
 dropafterack_ratelim: