 @@ -1,1716 +1,1726 @@
-/*	$NetBSD: tcp_output.c,v 1.183 2015/05/16 01:15:34 kefren Exp $	*/
+/*	$NetBSD: tcp_output.c,v 1.184 2015/07/24 04:33:50 matt 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, 2001, 2005, 2006 The NetBSD Foundation, Inc.
  * All rights reserved.
+ *
  * 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, 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_output.c	8.4 (Berkeley) 5/24/95
  */
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: tcp_output.c,v 1.183 2015/05/16 01:15:34 kefren Exp $");
+__KERNEL_RCSID(0, "$NetBSD: tcp_output.c,v 1.184 2015/07/24 04:33:50 matt Exp $");
 #include "opt_inet.h"
 #include "opt_ipsec.h"
 #include "opt_tcp_debug.h"
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/mbuf.h>
 #include <sys/protosw.h>
 #include <sys/socket.h>
 #include <sys/socketvar.h>
 #include <sys/errno.h>
 #include <sys/domain.h>
 #include <sys/kernel.h>
 #ifdef TCP_SIGNATURE
 #include <sys/md5.h>
 #endif
 #include <net/if.h>
 #include <net/route.h>
 #include <netinet/in.h>
 #include <netinet/in_systm.h>
 #include <netinet/ip.h>
 #include <netinet/in_pcb.h>
 #include <netinet/ip_var.h>
 #ifdef INET6
 #ifndef INET
 #include <netinet/in.h>
 #endif
 #include <netinet/ip6.h>
 #include <netinet6/in6_var.h>
 #include <netinet6/ip6_var.h>
 #include <netinet6/in6_pcb.h>
 #include <netinet6/nd6.h>
 #endif
 #ifdef IPSEC
 #include <netipsec/ipsec.h>
 #include <netipsec/key.h>
 #ifdef INET6
 #include <netipsec/ipsec6.h>
 #endif
 #endif	/* IPSEC*/
 #include <netinet/tcp.h>
 #define	TCPOUTFLAGS
 #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/tcpip.h>
 #include <netinet/tcp_debug.h>
 #include <netinet/in_offload.h>
 #include <netinet6/in6_offload.h>
 #ifdef notyet
 extern struct mbuf *m_copypack();
 #endif
 /*
  * Knob to enable Congestion Window Monitoring, and control
  * the burst size it allows.  Default burst is 4 packets, per
  * the Internet draft.
  */
 int	tcp_cwm = 0;
 int	tcp_cwm_burstsize = 4;
 int	tcp_do_autosndbuf = 1;
 int	tcp_autosndbuf_inc = 8 * 1024;
 int	tcp_autosndbuf_max = 256 * 1024;
 #ifdef TCP_OUTPUT_COUNTERS
 #include <sys/device.h>
 extern struct evcnt tcp_output_bigheader;
 extern struct evcnt tcp_output_predict_hit;
 extern struct evcnt tcp_output_predict_miss;
 extern struct evcnt tcp_output_copysmall;
 extern struct evcnt tcp_output_copybig;
 extern struct evcnt tcp_output_refbig;
 #define	TCP_OUTPUT_COUNTER_INCR(ev)	(ev)->ev_count++
 #else
 #define	TCP_OUTPUT_COUNTER_INCR(ev)	/* nothing */
 #endif /* TCP_OUTPUT_COUNTERS */
 static
 #ifndef GPROF
 inline
 #endif
 int
 tcp_segsize(struct tcpcb *tp, int *txsegsizep, int *rxsegsizep,
     bool *alwaysfragp)
+{
 #ifdef INET
 	struct inpcb *inp = tp->t_inpcb;
 #endif
 #ifdef INET6
 	struct in6pcb *in6p = tp->t_in6pcb;
 #endif
 	struct socket *so = NULL;
 	struct rtentry *rt;
 	struct ifnet *ifp;
 	int size;
 	int hdrlen;
 	int optlen;
 	*alwaysfragp = false;
 #ifdef DIAGNOSTIC
 	if (tp->t_inpcb && tp->t_in6pcb)
 		panic("tcp_segsize: both t_inpcb and t_in6pcb are set");
 #endif
 	switch (tp->t_family) {
 #ifdef INET
 	case AF_INET:
 		hdrlen = sizeof(struct ip) + sizeof(struct tcphdr);
 		break;
 #endif
 #ifdef INET6
 	case AF_INET6:
 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
 		break;
 #endif
 	default:
 		size = tcp_mssdflt;
 		goto out;
+	}
 	rt = NULL;
 #ifdef INET
 	if (inp) {
 		rt = in_pcbrtentry(inp);
 		so = inp->inp_socket;
+	}
 #endif
 #ifdef INET6
 	if (in6p) {
 		rt = in6_pcbrtentry(in6p);
 		so = in6p->in6p_socket;
+	}
 #endif
 	if (rt == NULL) {
 		size = tcp_mssdflt;
 		goto out;
+	}
 	ifp = rt->rt_ifp;
 	size = tcp_mssdflt;
 	if (tp->t_mtudisc && rt->rt_rmx.rmx_mtu != 0) {
 #ifdef INET6
 		if (in6p && rt->rt_rmx.rmx_mtu < IPV6_MMTU) {
 			/*
 			 * RFC2460 section 5, last paragraph: if path MTU is
 			 * smaller than 1280, use 1280 as packet size and
 			 * attach fragment header.
 			 */
 			size = IPV6_MMTU - hdrlen - sizeof(struct ip6_frag);
 			*alwaysfragp = true;
 		} else
 			size = rt->rt_rmx.rmx_mtu - hdrlen;
 #else
 		size = rt->rt_rmx.rmx_mtu - hdrlen;
 #endif
 	} else if (ifp->if_flags & IFF_LOOPBACK)
 		size = ifp->if_mtu - hdrlen;
 #ifdef INET
 	else if (inp && tp->t_mtudisc)
 		size = ifp->if_mtu - hdrlen;
 	else if (inp && in_localaddr(inp->inp_faddr))
 		size = ifp->if_mtu - hdrlen;
 #endif
 #ifdef INET6
 	else if (in6p) {
 #ifdef INET
 		if (IN6_IS_ADDR_V4MAPPED(&in6p->in6p_faddr)) {
 			/* mapped addr case */
 			struct in_addr d;
 			bcopy(&in6p->in6p_faddr.s6_addr32[3], &d, sizeof(d));
 			if (tp->t_mtudisc || in_localaddr(d))
 				size = ifp->if_mtu - hdrlen;
 		} else
 #endif
+		{
 			/*
 			 * for IPv6, path MTU discovery is always turned on,
 			 * or the node must use packet size <= 1280.
 			 */
 			size = tp->t_mtudisc ? IN6_LINKMTU(ifp) : IPV6_MMTU;
 			size -= hdrlen;
+		}
+	}
 #endif
  out:
 	/*
 	 * Now we must make room for whatever extra TCP/IP options are in
 	 * the packet.
 	 */
 	optlen = tcp_optlen(tp);
 	/*
 	 * XXX tp->t_ourmss should have the right size, but without this code
 	 * fragmentation will occur... need more investigation
 	 */
 #ifdef INET
 	if (inp) {
 #if defined(IPSEC)
 		if (ipsec_used &&
 		    !IPSEC_PCB_SKIP_IPSEC(inp->inp_sp, IPSEC_DIR_OUTBOUND))
 			optlen += ipsec4_hdrsiz_tcp(tp);
 #endif
 		optlen += ip_optlen(inp);
+	}
 #endif
 #ifdef INET6
 #ifdef INET
 	if (in6p && tp->t_family == AF_INET) {
 #if defined(IPSEC)
 		if (ipsec_used &&
 		    !IPSEC_PCB_SKIP_IPSEC(in6p->in6p_sp, IPSEC_DIR_OUTBOUND))
 			optlen += ipsec4_hdrsiz_tcp(tp);
 #endif
 		/* XXX size -= ip_optlen(in6p); */
 	} else
 #endif
 	if (in6p && tp->t_family == AF_INET6) {
 #if defined(IPSEC)
 		if (ipsec_used &&
 		    !IPSEC_PCB_SKIP_IPSEC(in6p->in6p_sp, IPSEC_DIR_OUTBOUND))
 			optlen += ipsec6_hdrsiz_tcp(tp);
 #endif
 		optlen += ip6_optlen(in6p);
+	}
 #endif
 	size -= optlen;
 	/* there may not be any room for data if mtu is too small */
 	if (size < 0)
 		return (EMSGSIZE);
 	/*
 	 * *rxsegsizep holds *estimated* inbound segment size (estimation
 	 * assumes that path MTU is the same for both ways).  this is only
 	 * for silly window avoidance, do not use the value for other purposes.
+	 *
 	 * ipseclen is subtracted from both sides, this may not be right.
 	 * I'm not quite sure about this (could someone comment).
 	 */
 	*txsegsizep = min(tp->t_peermss - optlen, size);
 	/*
 	 * Never send more than half a buffer full.  This insures that we can
 	 * always keep 2 packets on the wire, no matter what SO_SNDBUF is, and
 	 * therefore acks will never be delayed unless we run out of data to
 	 * transmit.
 	 */
 	if (so)
 		*txsegsizep = min(so->so_snd.sb_hiwat >> 1, *txsegsizep);
 	*rxsegsizep = min(tp->t_ourmss - optlen, size);
 	if (*txsegsizep != tp->t_segsz) {
 		/*
 		 * If the new segment size is larger, we don't want to
 		 * mess up the congestion window, but if it is smaller
 		 * we'll have to reduce the congestion window to ensure
 		 * that we don't get into trouble with initial windows
 		 * and the rest.  In any case, if the segment size
 		 * has changed, chances are the path has, too, and
 		 * our congestion window will be different.
 		 */
 		if (*txsegsizep < tp->t_segsz) {
 			tp->snd_cwnd = max((tp->snd_cwnd / tp->t_segsz)
 					   * *txsegsizep, *txsegsizep);
 			tp->snd_ssthresh = max((tp->snd_ssthresh / tp->t_segsz)
 						* *txsegsizep, *txsegsizep);
+		}
 		tp->t_segsz = *txsegsizep;
+	}
 	return (0);
+}
 static
 #ifndef GPROF
 inline
 #endif
 int
 tcp_build_datapkt(struct tcpcb *tp, struct socket *so, int off,
     long len, int hdrlen, struct mbuf **mp)
+{
 	struct mbuf *m, *m0;
 	uint64_t *tcps;
 	tcps = TCP_STAT_GETREF();
 	if (tp->t_force && len == 1)
 		tcps[TCP_STAT_SNDPROBE]++;
 	else if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {
 		tp->t_sndrexmitpack++;
 		tcps[TCP_STAT_SNDREXMITPACK]++;
 		tcps[TCP_STAT_SNDREXMITBYTE] += len;
 	} else {
 		tcps[TCP_STAT_SNDPACK]++;
 		tcps[TCP_STAT_SNDBYTE] += len;
+	}
 	TCP_STAT_PUTREF();
 #ifdef notyet
 	if ((m = m_copypack(so->so_snd.sb_mb, off,
 	    (int)len, max_linkhdr + hdrlen)) == 0)
 		return (ENOBUFS);
 	/*
 	 * m_copypack left space for our hdr; use it.
 	 */
 	m->m_len += hdrlen;
 	m->m_data -= hdrlen;
 #else
 	MGETHDR(m, M_DONTWAIT, MT_HEADER);
 	if (__predict_false(m == NULL))
 		return (ENOBUFS);
 	MCLAIM(m, &tcp_tx_mowner);
 	/*
 	 * XXX Because other code assumes headers will fit in
 	 * XXX one header mbuf.
+	 *
 	 * (This code should almost *never* be run.)
 	 */
 	if (__predict_false((max_linkhdr + hdrlen) > MHLEN)) {
 		TCP_OUTPUT_COUNTER_INCR(&tcp_output_bigheader);
 		MCLGET(m, M_DONTWAIT);
 		if ((m->m_flags & M_EXT) == 0) {
 			m_freem(m);
 			return (ENOBUFS);
+		}
+	}
 	m->m_data += max_linkhdr;
 	m->m_len = hdrlen;
 	/*
 	 * To avoid traversing the whole sb_mb chain for correct
 	 * data to send, remember last sent mbuf, its offset and
 	 * the sent size.  When called the next time, see if the
 	 * data to send is directly following the previous transfer.
 	 * This is important for large TCP windows.
 	 */
 	if (off == 0 || tp->t_lastm == NULL ||
 	    (tp->t_lastoff + tp->t_lastlen) != off) {
 		TCP_OUTPUT_COUNTER_INCR(&tcp_output_predict_miss);
 		/*
 		 * Either a new packet or a retransmit.
 		 * Start from the beginning.
 		 */
 		tp->t_lastm = so->so_snd.sb_mb;
 		tp->t_inoff = off;
 	} else {
 		TCP_OUTPUT_COUNTER_INCR(&tcp_output_predict_hit);
 		tp->t_inoff += tp->t_lastlen;
+	}
 	/* Traverse forward to next packet */
 	while (tp->t_inoff > 0) {
 		if (tp->t_lastm == NULL)
 			panic("tp->t_lastm == NULL");
 		if (tp->t_inoff < tp->t_lastm->m_len)
 			break;
 		tp->t_inoff -= tp->t_lastm->m_len;
 		tp->t_lastm = tp->t_lastm->m_next;
+	}
 	tp->t_lastoff = off;
 	tp->t_lastlen = len;
 	m0 = tp->t_lastm;
 	off = tp->t_inoff;
 	if (len <= M_TRAILINGSPACE(m)) {
 		m_copydata(m0, off, (int) len, mtod(m, char *) + hdrlen);
 		m->m_len += len;
 		TCP_OUTPUT_COUNTER_INCR(&tcp_output_copysmall);
 	} else {
 		m->m_next = m_copym(m0, off, (int) len, M_DONTWAIT);
 		if (m->m_next == NULL) {
 			m_freem(m);
 			return (ENOBUFS);
+		}
 #ifdef TCP_OUTPUT_COUNTERS
 		if (m->m_next->m_flags & M_EXT)
 			TCP_OUTPUT_COUNTER_INCR(&tcp_output_refbig);
 		else
 			TCP_OUTPUT_COUNTER_INCR(&tcp_output_copybig);
 #endif /* TCP_OUTPUT_COUNTERS */
+	}
 #endif
 	*mp = m;
 	return (0);
+}
 /*
  * Tcp output routine: figure out what should be sent and send it.
  */
 int
 tcp_output(struct tcpcb *tp)
+{
 	struct rtentry *rt;
 	struct socket *so;
 	struct route *ro;
 	long len, win;
 	int off, flags, error;
 	struct mbuf *m;
 	struct ip *ip;
 #ifdef INET6
 	struct ip6_hdr *ip6;
 #endif
 	struct tcphdr *th;
 	u_char opt[MAX_TCPOPTLEN];
 #define OPT_FITS(more)	((optlen + (more)) < sizeof(opt))
 	unsigned optlen, hdrlen, packetlen;
 	unsigned int sack_numblks;
 	int idle, sendalot, txsegsize, rxsegsize;
 	int txsegsize_nosack;
 	int maxburst = TCP_MAXBURST;
 	int af;		/* address family on the wire */
 	int iphdrlen;
 	int has_tso4, has_tso6;
 	int has_tso, use_tso;
 	bool alwaysfrag;
 	int sack_rxmit;
 	int sack_bytes_rxmt;
 	int ecn_tos;
 	struct sackhole *p;
 #ifdef TCP_SIGNATURE
 	int sigoff = 0;
 #endif
 	uint64_t *tcps;
 #ifdef DIAGNOSTIC
 	if (tp->t_inpcb && tp->t_in6pcb)
 		panic("tcp_output: both t_inpcb and t_in6pcb are set");
 #endif
 	so = NULL;
 	ro = NULL;
 	if (tp->t_inpcb) {
 		so = tp->t_inpcb->inp_socket;
 		ro = &tp->t_inpcb->inp_route;
+	}
 #ifdef INET6
 	else if (tp->t_in6pcb) {
 		so = tp->t_in6pcb->in6p_socket;
 		ro = &tp->t_in6pcb->in6p_route;
+	}
 #endif
 	switch (af = tp->t_family) {
 #ifdef INET
 	case AF_INET:
 		if (tp->t_inpcb)
 			break;
 #ifdef INET6
 		/* mapped addr case */
 		if (tp->t_in6pcb)
 			break;
 #endif
 		return (EINVAL);
 #endif
 #ifdef INET6
 	case AF_INET6:
 		if (tp->t_in6pcb)
 			break;
 		return (EINVAL);
 #endif
 	default:
 		return (EAFNOSUPPORT);
+	}
 	if (tcp_segsize(tp, &txsegsize, &rxsegsize, &alwaysfrag))
 		return (EMSGSIZE);
 	idle = (tp->snd_max == tp->snd_una);
 	/*
 	 * Determine if we can use TCP segmentation offload:
 	 * - If we're using IPv4
 	 * - If there is not an IPsec policy that prevents it
 	 * - If the interface can do it
 	 */
 	has_tso4 = has_tso6 = false;
 #if defined(INET)
 	has_tso4 = tp->t_inpcb != NULL &&
 #if defined(IPSEC)
 	    (!ipsec_used || IPSEC_PCB_SKIP_IPSEC(tp->t_inpcb->inp_sp,
 	    IPSEC_DIR_OUTBOUND)) &&
 #endif
 	    (rt = rtcache_validate(&tp->t_inpcb->inp_route)) != NULL &&
 	    (rt->rt_ifp->if_capenable & IFCAP_TSOv4) != 0;
 #endif /* defined(INET) */
 #if defined(INET6)
 	has_tso6 = tp->t_in6pcb != NULL &&
 #if defined(IPSEC)
 	    (!ipsec_used || IPSEC_PCB_SKIP_IPSEC(tp->t_in6pcb->in6p_sp,
 	    IPSEC_DIR_OUTBOUND)) &&
 #endif
 	    (rt = rtcache_validate(&tp->t_in6pcb->in6p_route)) != NULL &&
 	    (rt->rt_ifp->if_capenable & IFCAP_TSOv6) != 0;
 #endif /* defined(INET6) */
 	has_tso = (has_tso4 || has_tso6) && !alwaysfrag;
 	/*
 	 * Restart Window computation.  From draft-floyd-incr-init-win-03:
+	 *
 	 *	Optionally, a TCP MAY set the restart window to the
 	 *	minimum of the value used for the initial window and
 	 *	the current value of cwnd (in other words, using a
 	 *	larger value for the restart window should never increase
 	 *	the size of cwnd).
 	 */
 	if (tcp_cwm) {
 		/*
 		 * Hughes/Touch/Heidemann Congestion Window Monitoring.
 		 * Count the number of packets currently pending
 		 * acknowledgement, and limit our congestion window
 		 * to a pre-determined allowed burst size plus that count.
 		 * This prevents bursting once all pending packets have
 		 * been acknowledged (i.e. transmission is idle).
+		 *
 		 * XXX Link this to Initial Window?
 		 */
 		tp->snd_cwnd = min(tp->snd_cwnd,
 		    (tcp_cwm_burstsize * txsegsize) +
 		    (tp->snd_nxt - tp->snd_una));
 	} else {
 		if (idle && (tcp_now - tp->t_rcvtime) >= tp->t_rxtcur) {
 			/*
 			 * We have been idle for "a while" and no acks are
 			 * expected to clock out any data we send --
 			 * slow start to get ack "clock" running again.
 			 */
 			int ss = tcp_init_win;
 #ifdef INET
 			if (tp->t_inpcb &&
 			    in_localaddr(tp->t_inpcb->inp_faddr))
 				ss = tcp_init_win_local;
 #endif
 #ifdef INET6
 			if (tp->t_in6pcb &&
 			    in6_localaddr(&tp->t_in6pcb->in6p_faddr))
 				ss = tcp_init_win_local;
 #endif
 			tp->snd_cwnd = min(tp->snd_cwnd,
 			    TCP_INITIAL_WINDOW(ss, txsegsize));
+		}
+	}
 	txsegsize_nosack = txsegsize;
 again:
 	ecn_tos = 0;
 	use_tso = has_tso;
 	if ((tp->t_flags & (TF_ECN_SND_CWR|TF_ECN_SND_ECE)) != 0) {
 		/* don't duplicate CWR/ECE. */
 		use_tso = 0;
+	}
 	TCP_REASS_LOCK(tp);
 	sack_numblks = tcp_sack_numblks(tp);
 	if (sack_numblks) {
 		int sackoptlen;
 		sackoptlen = TCP_SACK_OPTLEN(sack_numblks);
 		if (sackoptlen > txsegsize_nosack) {
 			sack_numblks = 0; /* give up SACK */
 			txsegsize = txsegsize_nosack;
 		} else {
 			if ((tp->rcv_sack_flags & TCPSACK_HAVED) != 0) {
 				/* don't duplicate D-SACK. */
 				use_tso = 0;
+			}
 			txsegsize = txsegsize_nosack - sackoptlen;
+		}
 	} else {
 		txsegsize = txsegsize_nosack;
+	}
 	/*
 	 * Determine length of data that should be transmitted, and
 	 * flags that should be used.  If there is some data or critical
 	 * controls (SYN, RST) to send, then transmit; otherwise,
 	 * investigate further.
+	 *
 	 * Readjust SACK information to avoid resending duplicate data.
 	 */
 	if (TCP_SACK_ENABLED(tp) && SEQ_LT(tp->snd_nxt, tp->snd_max))
 		tcp_sack_adjust(tp);
 	sendalot = 0;
 	off = tp->snd_nxt - tp->snd_una;
 	win = min(tp->snd_wnd, tp->snd_cwnd);
 	flags = tcp_outflags[tp->t_state];
 	/*
 	 * Send any SACK-generated retransmissions.  If we're explicitly trying
 	 * to send out new data (when sendalot is 1), bypass this function.
 	 * If we retransmit in fast recovery mode, decrement snd_cwnd, since
 	 * we're replacing a (future) new transmission with a retransmission
 	 * now, and we previously incremented snd_cwnd in tcp_input().
 	 */
 	/*
 	 * Still in sack recovery , reset rxmit flag to zero.
 	 */
 	sack_rxmit = 0;
 	sack_bytes_rxmt = 0;
 	len = 0;
 	p = NULL;
 	do {
 		long cwin;
 		if (!TCP_SACK_ENABLED(tp))
 			break;
 		if (tp->t_partialacks < 0)
 			break;
 		p = tcp_sack_output(tp, &sack_bytes_rxmt);
 		if (p == NULL)
 			break;
 		cwin = min(tp->snd_wnd, tp->snd_cwnd) - sack_bytes_rxmt;
 		if (cwin < 0)
 			cwin = 0;
 		/* Do not retransmit SACK segments beyond snd_recover */
 		if (SEQ_GT(p->end, tp->snd_recover)) {
 			/*
 			 * (At least) part of sack hole extends beyond
 			 * snd_recover. Check to see if we can rexmit data
 			 * for this hole.
 			 */
 			if (SEQ_GEQ(p->rxmit, tp->snd_recover)) {
 				/*
 				 * Can't rexmit any more data for this hole.
 				 * That data will be rexmitted in the next
 				 * sack recovery episode, when snd_recover
 				 * moves past p->rxmit.
 				 */
 				p = NULL;
 				break;
+			}
 			/* Can rexmit part of the current hole */
 			len = ((long)ulmin(cwin, tp->snd_recover - p->rxmit));
 		} else
 			len = ((long)ulmin(cwin, p->end - p->rxmit));
 		off = p->rxmit - tp->snd_una;
 		if (off + len > so->so_snd.sb_cc) {
 			/* 1 for TH_FIN */
 			KASSERT(off + len == so->so_snd.sb_cc + 1);
 			KASSERT(p->rxmit + len == tp->snd_max);
 			len = so->so_snd.sb_cc - off;
+		}
 		if (len > 0) {
 			sack_rxmit = 1;
 			sendalot = 1;
+		}
 	} while (/*CONSTCOND*/0);
 	/*
 	 * If in persist timeout with window of 0, send 1 byte.
 	 * Otherwise, if window is small but nonzero
 	 * and timer expired, we will send what we can
 	 * and go to transmit state.
 	 */
 	if (tp->t_force) {
 		if (win == 0) {
 			/*
 			 * If we still have some data to send, then
 			 * clear the FIN bit.  Usually this would
 			 * happen below when it realizes that we
 			 * aren't sending all the data.  However,
 			 * if we have exactly 1 byte of unset data,
 			 * then it won't clear the FIN bit below,
 			 * and if we are in persist state, we wind
 			 * up sending the packet without recording
 			 * that we sent the FIN bit.
+			 *
 			 * We can't just blindly clear the FIN bit,
 			 * because if we don't have any more data
 			 * to send then the probe will be the FIN
 			 * itself.
 			 */
 			if (off < so->so_snd.sb_cc)
 				flags &= ~TH_FIN;
 			win = 1;
 		} else {
 			TCP_TIMER_DISARM(tp, TCPT_PERSIST);
 			tp->t_rxtshift = 0;
+		}
+	}
 	if (sack_rxmit == 0) {
 		if (TCP_SACK_ENABLED(tp) && tp->t_partialacks >= 0) {
 			long cwin;
 			/*
 			 * We are inside of a SACK recovery episode and are
 			 * sending new data, having retransmitted all the
 			 * data possible in the scoreboard.
 			 */
 			if (tp->snd_wnd < so->so_snd.sb_cc) {
 				len = tp->snd_wnd - off;
 				flags &= ~TH_FIN;
 			} else {
 				len = so->so_snd.sb_cc - off;
+			}
 			/*
 			 * From FreeBSD:
 			 *  Don't remove this (len > 0) check !
 			 *  We explicitly check for len > 0 here (although it
 			 *  isn't really necessary), to work around a gcc
 			 *  optimization issue - to force gcc to compute
 			 *  len above. Without this check, the computation
 			 *  of len is bungled by the optimizer.
 			 */
 			if (len > 0) {
 				cwin = tp->snd_cwnd -
 				    (tp->snd_nxt - tp->sack_newdata) -
 				    sack_bytes_rxmt;
 				if (cwin < 0)
 					cwin = 0;
 				if (cwin < len) {
 					len = cwin;
 					flags &= ~TH_FIN;
+				}
+			}
 		} else if (win < so->so_snd.sb_cc) {
 			len = win - off;
 			flags &= ~TH_FIN;
 		} else {
 			len = so->so_snd.sb_cc - off;
+		}
+	}
 	if (len < 0) {
 		/*
 		 * If FIN has been sent but not acked,
 		 * but we haven't been called to retransmit,
 		 * len will be -1.  Otherwise, window shrank
 		 * after we sent into it.  If window shrank to 0,
 		 * cancel pending retransmit, pull snd_nxt back
 		 * to (closed) window, and set the persist timer
 		 * if it isn't already going.  If the window didn't
 		 * close completely, just wait for an ACK.
+		 *
 		 * If we have a pending FIN, either it has already been
 		 * transmitted or it is outside the window, so drop it.
 		 * If the FIN has been transmitted, but this is not a
 		 * retransmission, then len must be -1.  Therefore we also
 		 * prevent here the sending of `gratuitous FINs'.  This
 		 * eliminates the need to check for that case below (e.g.
 		 * to back up snd_nxt before the FIN so that the sequence
 		 * number is correct).
 		 */
 		len = 0;
 		flags &= ~TH_FIN;
 		if (win == 0) {
 			TCP_TIMER_DISARM(tp, TCPT_REXMT);
 			tp->t_rxtshift = 0;
 			tp->snd_nxt = tp->snd_una;
 			if (TCP_TIMER_ISARMED(tp, TCPT_PERSIST) == 0)
 				tcp_setpersist(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.
+	 *
 	 * The criteria to step up the send buffer one notch are:
 	 *  1. receive window of remote host is larger than send buffer
 	 *     (with a fudge factor of 5/4th);
 	 *  2. send buffer is filled to 7/8th with data (so we actually
 	 *     have data to make use of it);
 	 *  3. send buffer fill has not hit maximal automatic size;
 	 *  4. our send window (slow start and cogestion controlled) is
 	 *     larger than sent but unacknowledged data in send buffer.
+	 *
 	 * The remote host receive window scaling factor may limit the
 	 * growing of the send buffer before it reaches its allowed
 	 * maximum.
+	 *
 	 * It scales directly with slow start or congestion window
 	 * and does at most one step per received ACK.  This fast
 	 * scaling has the drawback of growing the send buffer beyond
 	 * what is strictly necessary to make full use of a given
 	 * delay*bandwith product.  However testing has shown this not
 	 * to be much of an problem.  At worst we are trading wasting
 	 * of available bandwith (the non-use of it) for wasting some
 	 * socket buffer memory.
+	 *
 	 * TODO: Shrink send buffer during idle periods together
 	 * with congestion window.  Requires another timer.
 	 */
 	if (tcp_do_autosndbuf && so->so_snd.sb_flags & SB_AUTOSIZE) {
 		if ((tp->snd_wnd / 4 * 5) >= so->so_snd.sb_hiwat &&
 		    so->so_snd.sb_cc >= (so->so_snd.sb_hiwat / 8 * 7) &&
 		    so->so_snd.sb_cc < tcp_autosndbuf_max &&
 		    win >= (so->so_snd.sb_cc - (tp->snd_nxt - tp->snd_una))) {
 			if (!sbreserve(&so->so_snd,
 			    min(so->so_snd.sb_hiwat + tcp_autosndbuf_inc,
 			     tcp_autosndbuf_max), so))
 				so->so_snd.sb_flags &= ~SB_AUTOSIZE;
+		}
+	}
 	if (len > txsegsize) {
 		if (use_tso) {
 			/*
 			 * Truncate TSO transfers to IP_MAXPACKET, and make
 			 * sure that we send equal size transfers down the
 			 * stack (rather than big-small-big-small-...).
 			 */
 #ifdef INET6
 			CTASSERT(IPV6_MAXPACKET == IP_MAXPACKET);
 #endif
 			len = (min(len, IP_MAXPACKET) / txsegsize) * txsegsize;
 			if (len <= txsegsize) {
 				use_tso = 0;
+			}
 		} else
 			len = txsegsize;
 		flags &= ~TH_FIN;
 		sendalot = 1;
 	} else
 		use_tso = 0;
 	if (sack_rxmit) {
 		if (SEQ_LT(p->rxmit + len, tp->snd_una + so->so_snd.sb_cc))
 			flags &= ~TH_FIN;
+	}
 	win = sbspace(&so->so_rcv);
 	/*
 	 * Sender silly window avoidance.  If connection is idle
 	 * and can send all data, a maximum segment,
 	 * at least a maximum default-size segment do it,
 	 * or are forced, do it; otherwise don't bother.
 	 * If peer's buffer is tiny, then send
 	 * when window is at least half open.
 	 * If retransmitting (possibly after persist timer forced us
 	 * to send into a small window), then must resend.
 	 */
 	if (len) {
 		if (len >= txsegsize)
 			goto send;
 		if ((so->so_state & SS_MORETOCOME) == 0 &&
 		    ((idle || tp->t_flags & TF_NODELAY) &&
 		     len + off >= so->so_snd.sb_cc))
 			goto send;
 		if (tp->t_force)
 			goto send;
 		if (len >= tp->max_sndwnd / 2)
 			goto send;
 		if (SEQ_LT(tp->snd_nxt, tp->snd_max))
 			goto send;
 		if (sack_rxmit)
 			goto send;
+	}
 	/*
 	 * Compare available window to amount of window known to peer
 	 * (as advertised window less next expected input).  If the
 	 * difference is at least twice the size of the largest segment
 	 * we expect to receive (i.e. two segments) or at least 50% of
 	 * the maximum possible window, then want to send a window update
 	 * to peer.
 	 */
 	if (win > 0) {
 		/*
 		 * "adv" is the amount we can increase the window,
 		 * taking into account that we are limited by
 		 * TCP_MAXWIN << tp->rcv_scale.
 		 */
 		long adv = min(win, (long)TCP_MAXWIN << tp->rcv_scale) -
 			(tp->rcv_adv - tp->rcv_nxt);
 		/*
 		 * If the new window size ends up being the same as the old
 		 * size when it is scaled, then don't force a window update.
 		 */
 		if ((tp->rcv_adv - tp->rcv_nxt) >> tp->rcv_scale ==
 		    (adv + tp->rcv_adv - tp->rcv_nxt) >> tp->rcv_scale)
 			goto dontupdate;
 		if (adv >= (long) (2 * rxsegsize))
 			goto send;
 		if (2 * adv >= (long) so->so_rcv.sb_hiwat)
 			goto send;
+	}
 dontupdate:
 	/*
 	 * Send if we owe peer an ACK.
 	 */
 	if (tp->t_flags & TF_ACKNOW)
 		goto send;
 	if (flags & (TH_SYN|TH_FIN|TH_RST))
 		goto send;
 	if (SEQ_GT(tp->snd_up, tp->snd_una))
 		goto send;
 	/*
 	 * In SACK, it is possible for tcp_output to fail to send a segment
 	 * after the retransmission timer has been turned off.  Make sure
 	 * that the retransmission timer is set.
 	 */
 	if (TCP_SACK_ENABLED(tp) && SEQ_GT(tp->snd_max, tp->snd_una) &&
 	    !TCP_TIMER_ISARMED(tp, TCPT_REXMT) &&
 	    !TCP_TIMER_ISARMED(tp, TCPT_PERSIST)) {
 		TCP_TIMER_ARM(tp, TCPT_REXMT, tp->t_rxtcur);
 		goto just_return;
+	}
 	/*
 	 * TCP window updates are not reliable, rather a polling protocol
 	 * using ``persist'' packets is used to insure receipt of window
 	 * updates.  The three ``states'' for the output side are:
 	 *	idle			not doing retransmits or persists
 	 *	persisting		to move a small or zero window
 	 *	(re)transmitting	and thereby not persisting
+	 *
 	 * tp->t_timer[TCPT_PERSIST]
 	 *	is set when we are in persist state.
 	 * tp->t_force
 	 *	is set when we are called to send a persist packet.
 	 * tp->t_timer[TCPT_REXMT]
 	 *	is set when we are retransmitting
 	 * The output side is idle when both timers are zero.
+	 *
 	 * If send window is too small, there is data to transmit, and no
 	 * retransmit or persist is pending, then go to persist state.
 	 * If nothing happens soon, send when timer expires:
 	 * if window is nonzero, transmit what we can,
 	 * otherwise force out a byte.
 	 */
 	if (so->so_snd.sb_cc && TCP_TIMER_ISARMED(tp, TCPT_REXMT) == 0 &&
 	    TCP_TIMER_ISARMED(tp, TCPT_PERSIST) == 0) {
 		tp->t_rxtshift = 0;
 		tcp_setpersist(tp);
+	}
 	/*
 	 * No reason to send a segment, just return.
 	 */
 just_return:
 	TCP_REASS_UNLOCK(tp);
 	return (0);
 send:
 	/*
 	 * Before ESTABLISHED, force sending of initial options
 	 * unless TCP set not to do any options.
 	 * NOTE: we assume that the IP/TCP header plus TCP options
 	 * always fit in a single mbuf, leaving room for a maximum
 	 * link header, i.e.
 	 *	max_linkhdr + sizeof (struct tcpiphdr) + optlen <= MCLBYTES
 	 */
 	optlen = 0;
 	switch (af) {
 #ifdef INET
 	case AF_INET:
 		iphdrlen = sizeof(struct ip) + sizeof(struct tcphdr);
 		break;
 #endif
 #ifdef INET6
 	case AF_INET6:
 		iphdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
 		break;
 #endif
 	default:	/*pacify gcc*/
 		iphdrlen = 0;
 		break;
+	}
 	hdrlen = iphdrlen;
 	if (flags & TH_SYN) {
 		struct rtentry *synrt;
 		synrt = NULL;
 #ifdef INET
 		if (tp->t_inpcb)
 			synrt = in_pcbrtentry(tp->t_inpcb);
 #endif
 #ifdef INET6
 		if (tp->t_in6pcb)
 			synrt = in6_pcbrtentry(tp->t_in6pcb);
 #endif
 		tp->snd_nxt = tp->iss;
 		tp->t_ourmss = tcp_mss_to_advertise(synrt != NULL ?
 						    synrt->rt_ifp : NULL, af);
 		if ((tp->t_flags & TF_NOOPT) == 0 && OPT_FITS(4)) {
 			opt[0] = TCPOPT_MAXSEG;
 			opt[1] = 4;
 			opt[2] = (tp->t_ourmss >> 8) & 0xff;
 			opt[3] = tp->t_ourmss & 0xff;
 			optlen = 4;
 			if ((tp->t_flags & TF_REQ_SCALE) &&
 			    ((flags & TH_ACK) == 0 ||
 			    (tp->t_flags & TF_RCVD_SCALE)) &&
 			    OPT_FITS(4)) {
 				*((u_int32_t *) (opt + optlen)) = htonl(
 					TCPOPT_NOP << 24 |
 					TCPOPT_WINDOW << 16 |
 					TCPOLEN_WINDOW << 8 |
 					tp->request_r_scale);
 				optlen += 4;
+			}
 			if (tcp_do_sack && OPT_FITS(4)) {
 				u_int8_t *cp = (u_int8_t *)(opt + optlen);
 				cp[0] = TCPOPT_SACK_PERMITTED;
 				cp[1] = 2;
 				cp[2] = TCPOPT_NOP;
 				cp[3] = TCPOPT_NOP;
 				optlen += 4;
+			}
+		}
+	}
 	/*
 	 * Send a timestamp and echo-reply if this is a SYN and our side
 	 * wants to use timestamps (TF_REQ_TSTMP is set) or both our side
 	 * and our peer have sent timestamps in our SYN's.
 	 */
 	if ((tp->t_flags & (TF_REQ_TSTMP|TF_NOOPT)) == TF_REQ_TSTMP &&
 	     (flags & TH_RST) == 0 &&
 	    ((flags & (TH_SYN|TH_ACK)) == TH_SYN ||
 	     (tp->t_flags & TF_RCVD_TSTMP)) && OPT_FITS(TCPOLEN_TSTAMP_APPA)) {
 		u_int32_t *lp = (u_int32_t *)(opt + optlen);
 		/* Form timestamp option as shown in appendix A of RFC 1323. */
 		*lp++ = htonl(TCPOPT_TSTAMP_HDR);
 		*lp++ = htonl(TCP_TIMESTAMP(tp));
 		*lp   = htonl(tp->ts_recent);
 		optlen += TCPOLEN_TSTAMP_APPA;
 		/* Set receive buffer autosizing timestamp. */
 		if (tp->rfbuf_ts == 0 && (so->so_rcv.sb_flags & SB_AUTOSIZE))
 			tp->rfbuf_ts = TCP_TIMESTAMP(tp);
+	}
 	/*
 	 * Tack on the SACK block if it is necessary.
 	 */
 	if (sack_numblks) {
 		int sack_len;
 		u_char *bp = (u_char *)(opt + optlen);
 		u_int32_t *lp = (u_int32_t *)(bp + 4);
 		struct ipqent *tiqe;
 		sack_len = sack_numblks * 8 + 2;
 		if (OPT_FITS(sack_len + 2)) {
 			bp[0] = TCPOPT_NOP;
 			bp[1] = TCPOPT_NOP;
 			bp[2] = TCPOPT_SACK;
 			bp[3] = sack_len;
 			if ((tp->rcv_sack_flags & TCPSACK_HAVED) != 0) {
 				sack_numblks--;
 				*lp++ = htonl(tp->rcv_dsack_block.left);
 				*lp++ = htonl(tp->rcv_dsack_block.right);
 				tp->rcv_sack_flags &= ~TCPSACK_HAVED;
+			}
 			for (tiqe = TAILQ_FIRST(&tp->timeq);
 			    sack_numblks > 0;
 			    tiqe = TAILQ_NEXT(tiqe, ipqe_timeq)) {
 				KASSERT(tiqe != NULL);
 				sack_numblks--;
 				*lp++ = htonl(tiqe->ipqe_seq);
 				*lp++ = htonl(tiqe->ipqe_seq + tiqe->ipqe_len +
 				    ((tiqe->ipqe_flags & TH_FIN) != 0 ? 1 : 0));
+			}
 			optlen += sack_len + 2;
+		}
+	}
 	TCP_REASS_UNLOCK(tp);
 #ifdef TCP_SIGNATURE
 	if ((tp->t_flags & TF_SIGNATURE) && OPT_FITS(TCPOLEN_SIGNATURE + 2)) {
 		u_char *bp;
 		/*
 		 * Initialize TCP-MD5 option (RFC2385)
 		 */
 		bp = (u_char *)opt + optlen;
 		*bp++ = TCPOPT_SIGNATURE;
 		*bp++ = TCPOLEN_SIGNATURE;
 		sigoff = optlen + 2;
 		memset(bp, 0, TCP_SIGLEN);
 		bp += TCP_SIGLEN;
 		optlen += TCPOLEN_SIGNATURE;
 		/*
 		 * Terminate options list and maintain 32-bit alignment.
  		 */
 		*bp++ = TCPOPT_NOP;
 		*bp++ = TCPOPT_EOL;
  		optlen += 2;
  	} else if ((tp->t_flags & TF_SIGNATURE) != 0) {
 		error = ECONNABORTED;
 		goto out;
+	}
 #endif /* TCP_SIGNATURE */
 	hdrlen += optlen;
 #ifdef DIAGNOSTIC
 	if (!use_tso && len > txsegsize)
 		panic("tcp data to be sent is larger than segment");
 	else if (use_tso && len > IP_MAXPACKET)
 		panic("tcp data to be sent is larger than max TSO size");
 	if (max_linkhdr + hdrlen > MCLBYTES)
 		panic("tcphdr too big");
 #endif
 	/*
 	 * Grab a header mbuf, attaching a copy of data to
 	 * be transmitted, and initialize the header from
 	 * the template for sends on this connection.
 	 */
 	if (len) {
 		error = tcp_build_datapkt(tp, so, off, len, hdrlen, &m);
 		if (error)
 			goto out;
 		/*
 		 * If we're sending everything we've got, set PUSH.
 		 * (This will keep happy those implementations which only
 		 * give data to the user when a buffer fills or
 		 * a PUSH comes in.)
 		 */
 		if (off + len == so->so_snd.sb_cc)
 			flags |= TH_PUSH;
 	} else {
 		tcps = TCP_STAT_GETREF();
 		if (tp->t_flags & TF_ACKNOW)
 			tcps[TCP_STAT_SNDACKS]++;
 		else if (flags & (TH_SYN|TH_FIN|TH_RST))
 			tcps[TCP_STAT_SNDCTRL]++;
 		else if (SEQ_GT(tp->snd_up, tp->snd_una))
 			tcps[TCP_STAT_SNDURG]++;
 		else
 			tcps[TCP_STAT_SNDWINUP]++;
 		TCP_STAT_PUTREF();
 		MGETHDR(m, M_DONTWAIT, MT_HEADER);
 		if (m != NULL && max_linkhdr + hdrlen > MHLEN) {
 			MCLGET(m, M_DONTWAIT);
 			if ((m->m_flags & M_EXT) == 0) {
 				m_freem(m);
 				m = NULL;
+			}
+		}
 		if (m == NULL) {
 			error = ENOBUFS;
 			goto out;
+		}
 		MCLAIM(m, &tcp_tx_mowner);
 		m->m_data += max_linkhdr;
 		m->m_len = hdrlen;
+	}
 	m->m_pkthdr.rcvif = NULL;
 	switch (af) {
 #ifdef INET
 	case AF_INET:
 		ip = mtod(m, struct ip *);
 #ifdef INET6
 		ip6 = NULL;
 #endif
 		th = (struct tcphdr *)(ip + 1);
 		break;
 #endif
 #ifdef INET6
 	case AF_INET6:
 		ip = NULL;
 		ip6 = mtod(m, struct ip6_hdr *);
 		th = (struct tcphdr *)(ip6 + 1);
 		break;
 #endif
 	default:	/*pacify gcc*/
 		ip = NULL;
 #ifdef INET6
 		ip6 = NULL;
 #endif
 		th = NULL;
 		break;
+	}
 	if (tp->t_template == 0)
 		panic("tcp_output");
 	if (tp->t_template->m_len < iphdrlen)
 		panic("tcp_output");
 	bcopy(mtod(tp->t_template, void *), mtod(m, void *), iphdrlen);
 	/*
 	 * If we are starting a connection, send ECN setup
 	 * SYN packet. If we are on a retransmit, we may
 	 * resend those bits a number of times as per
 	 * RFC 3168.
 	 */
 	if (tp->t_state == TCPS_SYN_SENT && tcp_do_ecn) {
 		if (tp->t_flags & TF_SYN_REXMT) {
 			if (tp->t_ecn_retries--)
 				flags |= TH_ECE|TH_CWR;
 		} else {
 			flags |= TH_ECE|TH_CWR;
 			tp->t_ecn_retries = tcp_ecn_maxretries;
+		}
+	}
 	if (TCP_ECN_ALLOWED(tp)) {
 		/*
 		 * If the peer has ECN, mark data packets
 		 * ECN capable. Ignore pure ack packets, retransmissions
 		 * and window probes.
 		 */
 		if (len > 0 && SEQ_GEQ(tp->snd_nxt, tp->snd_max) &&
 		    !(tp->t_force && len == 1)) {
 			ecn_tos = IPTOS_ECN_ECT0;
 			TCP_STATINC(TCP_STAT_ECN_ECT);
+		}
 		/*
 		 * Reply with proper ECN notifications.
 		 */
 		if (tp->t_flags & TF_ECN_SND_CWR) {
 			flags |= TH_CWR;
 			tp->t_flags &= ~TF_ECN_SND_CWR;
+		}
 		if (tp->t_flags & TF_ECN_SND_ECE) {
 			flags |= TH_ECE;
+		}
+	}
 	/*
 	 * If we are doing retransmissions, then snd_nxt will
 	 * not reflect the first unsent octet.  For ACK only
 	 * packets, we do not want the sequence number of the
 	 * retransmitted packet, we want the sequence number
 	 * of the next unsent octet.  So, if there is no data
 	 * (and no SYN or FIN), use snd_max instead of snd_nxt
 	 * when filling in ti_seq.  But if we are in persist
 	 * state, snd_max might reflect one byte beyond the
 	 * right edge of the window, so use snd_nxt in that
 	 * case, since we know we aren't doing a retransmission.
 	 * (retransmit and persist are mutually exclusive...)
 	 */
 	if (TCP_SACK_ENABLED(tp) && sack_rxmit) {
 		th->th_seq = htonl(p->rxmit);
 		p->rxmit += len;
 	} else {
 		if (len || (flags & (TH_SYN|TH_FIN)) ||
 		    TCP_TIMER_ISARMED(tp, TCPT_PERSIST))
 			th->th_seq = htonl(tp->snd_nxt);
 		else
 			th->th_seq = htonl(tp->snd_max);
+	}
 	th->th_ack = htonl(tp->rcv_nxt);
 	if (optlen) {
 		bcopy((void *)opt, (void *)(th + 1), optlen);
 		th->th_off = (sizeof (struct tcphdr) + optlen) >> 2;
+	}
 	th->th_flags = flags;
 	/*
 	 * Calculate receive window.  Don't shrink window,
 	 * but avoid silly window syndrome.
 	 */
 	if (win < (long)(so->so_rcv.sb_hiwat / 4) && win < (long)rxsegsize)
 		win = 0;
 	if (win > (long)TCP_MAXWIN << tp->rcv_scale)
 		win = (long)TCP_MAXWIN << tp->rcv_scale;
 	if (win < (long)(int32_t)(tp->rcv_adv - tp->rcv_nxt))
 		win = (long)(int32_t)(tp->rcv_adv - tp->rcv_nxt);
 	th->th_win = htons((u_int16_t) (win>>tp->rcv_scale));
 	if (th->th_win == 0) {
 		tp->t_sndzerowin++;
+	}
 	if (SEQ_GT(tp->snd_up, tp->snd_nxt)) {
 		u_int32_t urp = tp->snd_up - tp->snd_nxt;
 		if (urp > IP_MAXPACKET)
 			urp = IP_MAXPACKET;
 		th->th_urp = htons((u_int16_t)urp);
 		th->th_flags |= TH_URG;
 	} else
 		/*
 		 * If no urgent pointer to send, then we pull
 		 * the urgent pointer to the left edge of the send window
 		 * so that it doesn't drift into the send window on sequence
 		 * number wraparound.
 		 */
 		tp->snd_up = tp->snd_una;		/* drag it along */
 #ifdef TCP_SIGNATURE
 	if (sigoff && (tp->t_flags & TF_SIGNATURE)) {
 		struct secasvar *sav;
 		u_int8_t *sigp;
 		sav = tcp_signature_getsav(m, th);
 		if (sav == NULL) {
 			if (m)
 				m_freem(m);
 			return (EPERM);
+		}
 		m->m_pkthdr.len = hdrlen + len;
 		sigp = (char *)th + sizeof(*th) + sigoff;
 		tcp_signature(m, th, (char *)th - mtod(m, char *), sav, sigp);
 		key_sa_recordxfer(sav, m);
 		KEY_FREESAV(&sav);
+	}
 #endif
 	/*
 	 * Set ourselves up to be checksummed just before the packet
 	 * hits the wire.
 	 */
 	switch (af) {
 #ifdef INET
 	case AF_INET:
 		m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
 		if (use_tso) {
 			m->m_pkthdr.segsz = txsegsize;
 			m->m_pkthdr.csum_flags = M_CSUM_TSOv4;
 		} else {
 			m->m_pkthdr.csum_flags = M_CSUM_TCPv4;
 			if (len + optlen) {
 				/* Fixup the pseudo-header checksum. */
 				/* XXXJRT Not IP Jumbogram safe. */
 				th->th_sum = in_cksum_addword(th->th_sum,
 				    htons((u_int16_t) (len + optlen)));
+			}
+		}
 		break;
 #endif
 #ifdef INET6
 	case AF_INET6:
 		m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
 		if (use_tso) {
 			m->m_pkthdr.segsz = txsegsize;
 			m->m_pkthdr.csum_flags = M_CSUM_TSOv6;
 		} else {
 			m->m_pkthdr.csum_flags = M_CSUM_TCPv6;
 			if (len + optlen) {
 				/* Fixup the pseudo-header checksum. */
 				/* XXXJRT: Not IPv6 Jumbogram safe. */
 				th->th_sum = in_cksum_addword(th->th_sum,
 				    htons((u_int16_t) (len + optlen)));
+			}
+		}
 		break;
 #endif
+	}
 	/*
 	 * In transmit state, time the transmission and arrange for
 	 * the retransmit.  In persist state, just set snd_max.
 	 */
 	if (tp->t_force == 0 || TCP_TIMER_ISARMED(tp, TCPT_PERSIST) == 0) {
 		tcp_seq startseq = tp->snd_nxt;
 		/*
 		 * Advance snd_nxt over sequence space of this segment.
 		 * There are no states in which we send both a SYN and a FIN,
 		 * so we collapse the tests for these flags.
 		 */
 		if (flags & (TH_SYN|TH_FIN))
 			tp->snd_nxt++;
 		if (sack_rxmit)
 			goto timer;
 		tp->snd_nxt += len;
 		if (SEQ_GT(tp->snd_nxt, tp->snd_max)) {
 			tp->snd_max = tp->snd_nxt;
 			/*
 			 * Time this transmission if not a retransmission and
 			 * not currently timing anything.
 			 */
 			if (tp->t_rtttime == 0) {
 				tp->t_rtttime = tcp_now;
 				tp->t_rtseq = startseq;
 				TCP_STATINC(TCP_STAT_SEGSTIMED);
+			}
+		}
 		/*
 		 * Set retransmit timer if not currently set,
 		 * and not doing an ack or a keep-alive probe.
 		 * Initial value for retransmit timer is smoothed
 		 * round-trip time + 2 * round-trip time variance.
 		 * Initialize shift counter which is used for backoff
 		 * of retransmit time.
 		 */
 timer:
-		if (TCP_TIMER_ISARMED(tp, TCPT_REXMT) == 0 &&
+		if (TCP_TIMER_ISARMED(tp, TCPT_REXMT) == 0) {
-			((sack_rxmit && tp->snd_nxt != tp->snd_max) ||
+			if ((sack_rxmit && tp->snd_nxt != tp->snd_max)
-		    tp->snd_nxt != tp->snd_una)) {
+			    || tp->snd_nxt != tp->snd_una) {
-			if (TCP_TIMER_ISARMED(tp, TCPT_PERSIST)) {
+				if (TCP_TIMER_ISARMED(tp, TCPT_PERSIST)) {
-				TCP_TIMER_DISARM(tp, TCPT_PERSIST);
+					TCP_TIMER_DISARM(tp, TCPT_PERSIST);
 					tp->t_rxtshift = 0;
+				}
 				TCP_TIMER_ARM(tp, TCPT_REXMT, tp->t_rxtcur);
 			} else if (len == 0 && so->so_snd.sb_cc > 0
 			    && TCP_TIMER_ISARMED(tp, TCPT_PERSIST) == 0) {
 				/*
 				 * If we are sending a window probe and there's
 				 * unacked data in the socket, make sure at
 				 * least the persist timer is running.
 				 */
 				tp->t_rxtshift = 0;
 				tcp_setpersist(tp);
+			}
 			TCP_TIMER_ARM(tp, TCPT_REXMT, tp->t_rxtcur);
+		}
 	} else
 		if (SEQ_GT(tp->snd_nxt + len, tp->snd_max))
 			tp->snd_max = tp->snd_nxt + len;
 #ifdef TCP_DEBUG
 	/*
 	 * Trace.
 	 */
 	if (so->so_options & SO_DEBUG)
 		tcp_trace(TA_OUTPUT, tp->t_state, tp, m, 0);
 #endif
 	/*
 	 * Fill in IP length and desired time to live and
 	 * send to IP level.  There should be a better way
 	 * to handle ttl and tos; we could keep them in
 	 * the template, but need a way to checksum without them.
 	 */
 	m->m_pkthdr.len = hdrlen + len;
 	switch (af) {
 #ifdef INET
 	case AF_INET:
 		ip->ip_len = htons(m->m_pkthdr.len);
 		packetlen = m->m_pkthdr.len;
 		if (tp->t_inpcb) {
 			ip->ip_ttl = tp->t_inpcb->inp_ip.ip_ttl;
 			ip->ip_tos = tp->t_inpcb->inp_ip.ip_tos | ecn_tos;
+		}
 #ifdef INET6
 		else if (tp->t_in6pcb) {
 			ip->ip_ttl = in6_selecthlim(tp->t_in6pcb, NULL); /*XXX*/
 			ip->ip_tos = ecn_tos;	/*XXX*/
+		}
 #endif
 		break;
 #endif
 #ifdef INET6
 	case AF_INET6:
 		packetlen = m->m_pkthdr.len;
 		ip6->ip6_nxt = IPPROTO_TCP;
 		if (tp->t_in6pcb) {
 			/*
 			 * we separately set hoplimit for every segment, since
 			 * the user might want to change the value via
 			 * setsockopt. Also, desired default hop limit might
 			 * be changed via Neighbor Discovery.
 			 */
 			ip6->ip6_hlim = in6_selecthlim_rt(tp->t_in6pcb);
+		}
 		ip6->ip6_flow |= htonl(ecn_tos << 20);
 		/* ip6->ip6_flow = ??? (from template) */
 		/* ip6_plen will be filled in ip6_output(). */
 		break;
 #endif
 	default:	/*pacify gcc*/
 		packetlen = 0;
 		break;
+	}
 	switch (af) {
 #ifdef INET
 	case AF_INET:
+	    {
 		struct mbuf *opts;
 		if (tp->t_inpcb)
 			opts = tp->t_inpcb->inp_options;
 		else
 			opts = NULL;
 		error = ip_output(m, opts, ro,
 			(tp->t_mtudisc ? IP_MTUDISC : 0) |
 			(so->so_options & SO_DONTROUTE), NULL, so);
 		break;
+	    }
 #endif
 #ifdef INET6
 	case AF_INET6:
+	    {
 		struct ip6_pktopts *opts;
 		if (tp->t_in6pcb)
 			opts = tp->t_in6pcb->in6p_outputopts;
 		else
 			opts = NULL;
 		error = ip6_output(m, opts, ro, so->so_options & SO_DONTROUTE,
 			NULL, so, NULL);
 		break;
+	    }
 #endif
 	default:
 		error = EAFNOSUPPORT;
 		break;
+	}
 	if (error) {
 out:
 		if (error == ENOBUFS) {
 			TCP_STATINC(TCP_STAT_SELFQUENCH);
 #ifdef INET
 			if (tp->t_inpcb)
 				tcp_quench(tp->t_inpcb, 0);
 #endif
 #ifdef INET6
 			if (tp->t_in6pcb)
 				tcp6_quench(tp->t_in6pcb, 0);
 #endif
 			error = 0;
 		} else if ((error == EHOSTUNREACH || error == ENETDOWN) &&
 		    TCPS_HAVERCVDSYN(tp->t_state)) {
 			tp->t_softerror = error;
 			error = 0;
+		}
 		/* Back out the seqence number advance. */
 		if (sack_rxmit)
 			p->rxmit -= len;
 		/* Restart the delayed ACK timer, if necessary. */
 		if (tp->t_flags & TF_DELACK)
 			TCP_RESTART_DELACK(tp);
 		return (error);
+	}
 	if (packetlen > tp->t_pmtud_mtu_sent)
 		tp->t_pmtud_mtu_sent = packetlen;
 	tcps = TCP_STAT_GETREF();
 	tcps[TCP_STAT_SNDTOTAL]++;
 	if (tp->t_flags & TF_DELACK)
 		tcps[TCP_STAT_DELACK]++;
 	TCP_STAT_PUTREF();
 	/*
 	 * Data sent (as far as we can tell).
 	 * If this advertises a larger window than any other segment,
 	 * then remember the size of the advertised window.
 	 * Any pending ACK has now been sent.
 	 */
 	if (win > 0 && SEQ_GT(tp->rcv_nxt+win, tp->rcv_adv))
 		tp->rcv_adv = tp->rcv_nxt + win;
 	tp->last_ack_sent = tp->rcv_nxt;
 	tp->t_flags &= ~TF_ACKNOW;
 	TCP_CLEAR_DELACK(tp);
 #ifdef DIAGNOSTIC
 	if (maxburst < 0)
 		printf("tcp_output: maxburst exceeded by %d\n", -maxburst);
 #endif
 	if (sendalot && (tp->t_congctl == &tcp_reno_ctl || --maxburst))
 		goto again;
 	return (0);
+}
 void
 tcp_setpersist(struct tcpcb *tp)
+{
 	int t = ((tp->t_srtt >> 2) + tp->t_rttvar) >> (1 + 2);
 	int nticks;
 	if (TCP_TIMER_ISARMED(tp, TCPT_REXMT))
 		panic("tcp_output REXMT");
 	/*
 	 * Start/restart persistance timer.
 	 */
 	if (t < tp->t_rttmin)
 		t = tp->t_rttmin;
 	TCPT_RANGESET(nticks, t * tcp_backoff[tp->t_rxtshift],
 	    TCPTV_PERSMIN, TCPTV_PERSMAX);
 	TCP_TIMER_ARM(tp, TCPT_PERSIST, nticks);
 	if (tp->t_rxtshift < TCP_MAXRXTSHIFT)
 		tp->t_rxtshift++;
+}