Make the TCP code compile without INET. Sort #includes and add #ifdef INETs.

Add some comments at #endifs given more nestedness.  To make the compiler
happy, some default initializations were added in accordance with the style
on the files.

Reviewed by:	gnn
Sponsored by:	The FreeBSD Foundation
Sponsored by:	iXsystems
MFC after:	4 days

7 files changed, 278 insertions, 97 deletions

diff --git a/sys/conf/files b/sys/conf/files
index 191238921ed3..1f86b6641912 100644
--- a/sys/conf/files
+++ b/sys/conf/files
@@ -2740,8 +2740,8 @@ netinet/ip_mroute.c		optional mrouting inet | mrouting inet6
 netinet/ip_options.c		optional inet
 netinet/ip_output.c		optional inet
 netinet/raw_ip.c		optional inet
-netinet/cc/cc.c			optional inet
-netinet/cc/cc_newreno.c		optional inet
+netinet/cc/cc.c			optional inet | inet6
+netinet/cc/cc_newreno.c		optional inet | inet6
 netinet/sctp_asconf.c		optional inet sctp
 netinet/sctp_auth.c		optional inet sctp
 netinet/sctp_bsd_addr.c		optional inet sctp
@@ -2758,18 +2758,18 @@ netinet/sctp_timer.c		optional inet sctp
 netinet/sctp_usrreq.c		optional inet sctp
 netinet/sctputil.c		optional inet sctp
 netinet/tcp_debug.c		optional tcpdebug
-netinet/tcp_hostcache.c		optional inet
-netinet/tcp_input.c		optional inet
-netinet/tcp_lro.c		optional inet
-netinet/tcp_output.c		optional inet
-netinet/tcp_offload.c		optional inet
-netinet/tcp_reass.c		optional inet
-netinet/tcp_sack.c		optional inet
-netinet/tcp_subr.c		optional inet
-netinet/tcp_syncache.c		optional inet
-netinet/tcp_timer.c		optional inet
-netinet/tcp_timewait.c		optional inet
-netinet/tcp_usrreq.c		optional inet
+netinet/tcp_hostcache.c		optional inet | inet6
+netinet/tcp_input.c		optional inet | inet6
+netinet/tcp_lro.c		optional inet | inet6
+netinet/tcp_output.c		optional inet | inet6
+netinet/tcp_offload.c		optional inet | inet6
+netinet/tcp_reass.c		optional inet | inet6
+netinet/tcp_sack.c		optional inet | inet6
+netinet/tcp_subr.c		optional inet | inet6
+netinet/tcp_syncache.c		optional inet | inet6
+netinet/tcp_timer.c		optional inet | inet6
+netinet/tcp_timewait.c		optional inet | inet6
+netinet/tcp_usrreq.c		optional inet | inet6
 netinet/udp_usrreq.c		optional inet | inet6
 netinet/libalias/alias.c	optional libalias inet | netgraph_nat inet
 netinet/libalias/alias_db.c	optional libalias inet | netgraph_nat inet
diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c
index 30e84296afec..70c1522680e8 100644
--- a/sys/netinet/tcp_input.c
+++ b/sys/netinet/tcp_input.c
@@ -367,12 +367,13 @@ cc_conn_init(struct tcpcb *tp)
 		tp->snd_cwnd = min(4 * tp->t_maxseg,
 		    max(2 * tp->t_maxseg, 4380));
 #ifdef INET6
-	else if ((isipv6 && in6_localaddr(&inp->in6p_faddr)) ||
-		 (!isipv6 && in_localaddr(inp->inp_faddr)))
-#else
-	else if (in_localaddr(inp->inp_faddr))
+	else if (isipv6 && in6_localaddr(&inp->in6p_faddr))
+		tp->snd_cwnd = tp->t_maxseg * V_ss_fltsz_local;
 #endif
+#if defined(INET) || defined(INET6)
+	else if (in_localaddr(inp->inp_faddr))
 		tp->snd_cwnd = tp->t_maxseg * V_ss_fltsz_local;
+#endif
 	else
 		tp->snd_cwnd = tp->t_maxseg * V_ss_fltsz;
 
@@ -542,37 +543,46 @@ tcp6_input(struct mbuf **mp, int *offp, int proto)
 	tcp_input(m, *offp);
 	return IPPROTO_DONE;
 }
-#endif
+#endif /* INET6 */
 
 void
 tcp_input(struct mbuf *m, int off0)
 {
-	struct tcphdr *th;
+	struct tcphdr *th = NULL;
 	struct ip *ip = NULL;
+#ifdef INET
 	struct ipovly *ipov;
+#endif
 	struct inpcb *inp = NULL;
 	struct tcpcb *tp = NULL;
 	struct socket *so = NULL;
 	u_char *optp = NULL;
 	int optlen = 0;
-	int len, tlen, off;
+#ifdef INET
+	int len;
+#endif
+	int tlen = 0, off;
 	int drop_hdrlen;
 	int thflags;
 	int rstreason = 0;	/* For badport_bandlim accounting purposes */
-	uint8_t iptos;
 #ifdef TCP_SIGNATURE
 	uint8_t sig_checked = 0;
 #endif
+	uint8_t iptos = 0;
+#ifdef INET
 #ifdef IPFIREWALL_FORWARD
 	struct m_tag *fwd_tag;
 #endif
+#endif /* INET */
 #ifdef INET6
 	struct ip6_hdr *ip6 = NULL;
 	int isipv6;
 #else
 	const void *ip6 = NULL;
+#if (defined(INET) && defined(IPFIREWALL_FORWARD)) || defined(TCPDEBUG)
 	const int isipv6 = 0;
 #endif
+#endif /* INET6 */
 	struct tcpopt to;		/* options in this segment */
 	char *s = NULL;			/* address and port logging */
 	int ti_locked;
@@ -597,8 +607,8 @@ tcp_input(struct mbuf *m, int off0)
 	to.to_flags = 0;
 	TCPSTAT_INC(tcps_rcvtotal);
 
-	if (isipv6) {
 #ifdef INET6
+	if (isipv6) {
 		/* IP6_EXTHDR_CHECK() is already done at tcp6_input(). */
 		ip6 = mtod(m, struct ip6_hdr *);
 		tlen = sizeof(*ip6) + ntohs(ip6->ip6_plen) - off0;
@@ -620,10 +630,13 @@ tcp_input(struct mbuf *m, int off0)
 			/* XXX stat */
 			goto drop;
 		}
-#else
-		th = NULL;		/* XXX: Avoid compiler warning. */
+	}
 #endif
-	} else {
+#if defined(INET) && defined(INET6)
+	else
+#endif
+#ifdef INET
+	{
 		/*
 		 * Get IP and TCP header together in first mbuf.
 		 * Note: IP leaves IP header in first mbuf.
@@ -675,13 +688,18 @@ tcp_input(struct mbuf *m, int off0)
 		/* Re-initialization for later version check */
 		ip->ip_v = IPVERSION;
 	}
+#endif /* INET */
 
 #ifdef INET6
 	if (isipv6)
 		iptos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
+#endif
+#if defined(INET) && defined(INET6)
 	else
 #endif
+#ifdef INET
 		iptos = ip->ip_tos;
+#endif
 
 	/*
 	 * Check that TCP offset makes sense,
@@ -694,13 +712,18 @@ tcp_input(struct mbuf *m, int off0)
 	}
 	tlen -= off;	/* tlen is used instead of ti->ti_len */
 	if (off > sizeof (struct tcphdr)) {
-		if (isipv6) {
 #ifdef INET6
+		if (isipv6) {
 			IP6_EXTHDR_CHECK(m, off0, off, );
 			ip6 = mtod(m, struct ip6_hdr *);
 			th = (struct tcphdr *)((caddr_t)ip6 + off0);
+		}
 #endif
-		} else {
+#if defined(INET) && defined(INET6)
+		else
+#endif
+#ifdef INET
+		{
 			if (m->m_len < sizeof(struct ip) + off) {
 				if ((m = m_pullup(m, sizeof (struct ip) + off))
 				    == NULL) {
@@ -712,6 +735,7 @@ tcp_input(struct mbuf *m, int off0)
 				th = (struct tcphdr *)((caddr_t)ip + off0);
 			}
 		}
+#endif
 		optlen = off - sizeof (struct tcphdr);
 		optp = (u_char *)(th + 1);
 	}
@@ -754,6 +778,7 @@ findpcb:
 		panic("%s: findpcb ti_locked %d\n", __func__, ti_locked);
 #endif
 
+#ifdef INET
 #ifdef IPFIREWALL_FORWARD
 	/*
 	 * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
@@ -787,21 +812,26 @@ findpcb:
 		m_tag_delete(m, fwd_tag);
 	} else
 #endif /* IPFIREWALL_FORWARD */
+#endif /* INET */
 	{
-		if (isipv6) {
 #ifdef INET6
+		if (isipv6)
 			inp = in6_pcblookup_hash(&V_tcbinfo,
 						 &ip6->ip6_src, th->th_sport,
 						 &ip6->ip6_dst, th->th_dport,
 						 INPLOOKUP_WILDCARD,
 						 m->m_pkthdr.rcvif);
 #endif
-		} else
+#if defined(INET) && defined(INET6)
+		else
+#endif
+#ifdef INET
 			inp = in_pcblookup_hash(&V_tcbinfo,
 						ip->ip_src, th->th_sport,
 						ip->ip_dst, th->th_dport,
 						INPLOOKUP_WILDCARD,
 						m->m_pkthdr.rcvif);
+#endif
 	}
 
 	/*
@@ -989,7 +1019,7 @@ relocked:
 			bcopy((char *)ip, (char *)tcp_saveipgen, sizeof(*ip));
 		tcp_savetcp = *th;
 	}
-#endif
+#endif /* TCPDEBUG */
 	/*
 	 * When the socket is accepting connections (the INPCB is in LISTEN
 	 * state) we look into the SYN cache if this is a new connection
@@ -1224,7 +1254,7 @@ relocked:
 			}
 			ifa_free(&ia6->ia_ifa);
 		}
-#endif
+#endif /* INET6 */
 		/*
 		 * Basic sanity checks on incoming SYN requests:
 		 *   Don't respond if the destination is a link layer
@@ -1243,8 +1273,8 @@ relocked:
 				"link layer address ignored\n", s, __func__);
 			goto dropunlock;
 		}
-		if (isipv6) {
 #ifdef INET6
+		if (isipv6) {
 			if (th->th_dport == th->th_sport &&
 			    IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &ip6->ip6_src)) {
 				if ((s = tcp_log_addrs(&inc, th, NULL, NULL)))
@@ -1261,8 +1291,13 @@ relocked:
 					"address ignored\n", s, __func__);
 				goto dropunlock;
 			}
+		}
 #endif
-		} else {
+#if defined(INET) && defined(INET6)
+		else
+#endif
+#ifdef INET
+		{
 			if (th->th_dport == th->th_sport &&
 			    ip->ip_dst.s_addr == ip->ip_src.s_addr) {
 				if ((s = tcp_log_addrs(&inc, th, NULL, NULL)))
@@ -1283,6 +1318,7 @@ relocked:
 				goto dropunlock;
 			}
 		}
+#endif
 		/*
 		 * SYN appears to be valid.  Create compressed TCP state
 		 * for syncache.
@@ -3020,7 +3056,9 @@ static void
 tcp_dropwithreset(struct mbuf *m, struct tcphdr *th, struct tcpcb *tp,
     int tlen, int rstreason)
 {
+#ifdef INET
 	struct ip *ip;
+#endif
 #ifdef INET6
 	struct ip6_hdr *ip6;
 #endif
@@ -3039,8 +3077,12 @@ tcp_dropwithreset(struct mbuf *m, struct tcphdr *th, struct tcpcb *tp,
 		    IN6_IS_ADDR_MULTICAST(&ip6->ip6_src))
 			goto drop;
 		/* IPv6 anycast check is done at tcp6_input() */
-	} else
+	}
 #endif
+#if defined(INET) && defined(INET6)
+	else
+#endif
+#ifdef INET
 	{
 		ip = mtod(m, struct ip *);
 		if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
@@ -3049,6 +3091,7 @@ tcp_dropwithreset(struct mbuf *m, struct tcphdr *th, struct tcpcb *tp,
 		    in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif))
 			goto drop;
 	}
+#endif
 
 	/* Perform bandwidth limiting. */
 	if (badport_bandlim(rstreason) < 0)
@@ -3308,8 +3351,8 @@ void
 tcp_mss_update(struct tcpcb *tp, int offer,
     struct hc_metrics_lite *metricptr, int *mtuflags)
 {
-	int mss;
-	u_long maxmtu;
+	int mss = 0;
+	u_long maxmtu = 0;
 	struct inpcb *inp = tp->t_inpcb;
 	struct hc_metrics_lite metrics;
 	int origoffer = offer;
@@ -3329,12 +3372,17 @@ tcp_mss_update(struct tcpcb *tp, int offer,
 	if (isipv6) {
 		maxmtu = tcp_maxmtu6(&inp->inp_inc, mtuflags);
 		tp->t_maxopd = tp->t_maxseg = V_tcp_v6mssdflt;
-	} else
+	}
 #endif
+#if defined(INET) && defined(INET6)
+	else
+#endif
+#ifdef INET
 	{
 		maxmtu = tcp_maxmtu(&inp->inp_inc, mtuflags);
 		tp->t_maxopd = tp->t_maxseg = V_tcp_mssdflt;
 	}
+#endif
 
 	/*
 	 * No route to sender, stay with default mss and return.
@@ -3395,14 +3443,19 @@ tcp_mss_update(struct tcpcb *tp, int offer,
 			if (!V_path_mtu_discovery &&
 			    !in6_localaddr(&inp->in6p_faddr))
 				mss = min(mss, V_tcp_v6mssdflt);
-		} else
+		}
 #endif
+#if defined(INET) && defined(INET6)
+		else
+#endif
+#ifdef INET
 		{
 			mss = maxmtu - min_protoh;
 			if (!V_path_mtu_discovery &&
 			    !in_localaddr(inp->inp_faddr))
 				mss = min(mss, V_tcp_mssdflt);
 		}
+#endif
 		/*
 		 * XXX - The above conditional (mss = maxmtu - min_protoh)
 		 * probably violates the TCP spec.
@@ -3540,14 +3593,19 @@ tcp_mssopt(struct in_conninfo *inc)
 		maxmtu = tcp_maxmtu6(inc, NULL);
 		thcmtu = tcp_hc_getmtu(inc); /* IPv4 and IPv6 */
 		min_protoh = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
-	} else
+	}
+#endif
+#if defined(INET) && defined(INET6)
+	else
 #endif
+#ifdef INET
 	{
 		mss = V_tcp_mssdflt;
 		maxmtu = tcp_maxmtu(inc, NULL);
 		thcmtu = tcp_hc_getmtu(inc); /* IPv4 and IPv6 */
 		min_protoh = sizeof(struct tcpiphdr);
 	}
+#endif
 	if (maxmtu && thcmtu)
 		mss = min(maxmtu, thcmtu) - min_protoh;
 	else if (maxmtu || thcmtu)
diff --git a/sys/netinet/tcp_output.c b/sys/netinet/tcp_output.c
index f6488a36090f..3ccb61a22332 100644
--- a/sys/netinet/tcp_output.c
+++ b/sys/netinet/tcp_output.c
@@ -173,7 +173,7 @@ tcp_output(struct tcpcb *tp)
 {
 	struct socket *so = tp->t_inpcb->inp_socket;
 	long len, recwin, sendwin;
-	int off, flags, error;
+	int off, flags, error = 0;	/* Keep compiler happy */
 	struct mbuf *m;
 	struct ip *ip = NULL;
 	struct ipovly *ipov = NULL;
@@ -659,7 +659,7 @@ send:
 		hdrlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr);
 	else
 #endif
-	hdrlen = sizeof (struct tcpiphdr);
+		hdrlen = sizeof (struct tcpiphdr);
 
 	/*
 	 * Compute options for segment.
@@ -866,7 +866,7 @@ send:
 				goto out;
 			}
 		}
-#endif
+#endif /* notyet */
 		/*
 		 * If we're sending everything we've got, set PUSH.
 		 * (This will keep happy those implementations which only
@@ -1189,7 +1189,7 @@ timer:
 #endif
 		ipov->ih_len = save;
 	}
-#endif
+#endif /* TCPDEBUG */
 
 	/*
 	 * Fill in IP length and desired time to live and
@@ -1216,8 +1216,12 @@ timer:
 			    tp->t_inpcb->in6p_outputopts, NULL,
 			    ((so->so_options & SO_DONTROUTE) ?
 			    IP_ROUTETOIF : 0), NULL, NULL, tp->t_inpcb);
-	} else
+	}
 #endif /* INET6 */
+#if defined(INET) && defined(INET6)
+	else
+#endif
+#ifdef INET
     {
 	ip->ip_len = m->m_pkthdr.len;
 #ifdef INET6
@@ -1239,6 +1243,7 @@ timer:
 	    ((so->so_options & SO_DONTROUTE) ? IP_ROUTETOIF : 0), 0,
 	    tp->t_inpcb);
     }
+#endif /* INET */
 	if (error) {
 
 		/*
diff --git a/sys/netinet/tcp_subr.c b/sys/netinet/tcp_subr.c
index f106b2d2e2b5..eafcb3dc315a 100644
--- a/sys/netinet/tcp_subr.c
+++ b/sys/netinet/tcp_subr.c
@@ -66,23 +66,20 @@ __FBSDID("$FreeBSD$");
 
 #include <netinet/cc.h>
 #include <netinet/in.h>
+#include <netinet/in_pcb.h>
 #include <netinet/in_systm.h>
+#include <netinet/in_var.h>
 #include <netinet/ip.h>
+#include <netinet/ip_icmp.h>
+#include <netinet/ip_var.h>
 #ifdef INET6
 #include <netinet/ip6.h>
-#endif
-#include <netinet/in_pcb.h>
-#ifdef INET6
 #include <netinet6/in6_pcb.h>
-#endif
-#include <netinet/in_var.h>
-#include <netinet/ip_var.h>
-#ifdef INET6
 #include <netinet6/ip6_var.h>
 #include <netinet6/scope6_var.h>
 #include <netinet6/nd6.h>
 #endif
-#include <netinet/ip_icmp.h>
+
 #include <netinet/tcp_fsm.h>
 #include <netinet/tcp_seq.h>
 #include <netinet/tcp_timer.h>
@@ -96,7 +93,9 @@ __FBSDID("$FreeBSD$");
 #ifdef TCPDEBUG
 #include <netinet/tcp_debug.h>
 #endif
+#ifdef INET6
 #include <netinet6/ip6protosw.h>
+#endif
 
 #ifdef IPSEC
 #include <netipsec/ipsec.h>
@@ -160,7 +159,7 @@ SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt,
     CTLTYPE_INT|CTLFLAG_RW, &VNET_NAME(tcp_v6mssdflt), 0,
     &sysctl_net_inet_tcp_mss_v6_check, "I",
    "Default TCP Maximum Segment Size for IPv6");
-#endif
+#endif /* INET6 */
 
 /*
  * Minimum MSS we accept and use. This prevents DoS attacks where
@@ -414,8 +413,12 @@ tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr)
 		ip6->ip6_plen = htons(sizeof(struct tcphdr));
 		ip6->ip6_src = inp->in6p_laddr;
 		ip6->ip6_dst = inp->in6p_faddr;
-	} else
+	}
+#endif /* INET6 */
+#if defined(INET6) && defined(INET)
+	else
 #endif
+#ifdef INET
 	{
 		struct ip *ip;
 
@@ -432,6 +435,7 @@ tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr)
 		ip->ip_src = inp->inp_laddr;
 		ip->ip_dst = inp->inp_faddr;
 	}
+#endif /* INET */
 	th->th_sport = inp->inp_lport;
 	th->th_dport = inp->inp_fport;
 	th->th_seq = 0;
@@ -493,7 +497,7 @@ tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m,
 	KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL"));
 
 #ifdef INET6
-	isipv6 = ((struct ip *)ipgen)->ip_v == 6;
+	isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4);
 	ip6 = ipgen;
 #endif /* INET6 */
 	ip = ipgen;
@@ -574,8 +578,12 @@ tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m,
 		ip6->ip6_plen = htons((u_short)(sizeof (struct tcphdr) +
 						tlen));
 		tlen += sizeof (struct ip6_hdr) + sizeof (struct tcphdr);
-	} else
+	}
 #endif
+#if defined(INET) && defined(INET6)
+	else
+#endif
+#ifdef INET
 	{
 		tlen += sizeof (struct tcpiphdr);
 		ip->ip_len = tlen;
@@ -583,6 +591,7 @@ tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m,
 		if (V_path_mtu_discovery)
 			ip->ip_off |= IP_DF;
 	}
+#endif
 	m->m_len = tlen;
 	m->m_pkthdr.len = tlen;
 	m->m_pkthdr.rcvif = NULL;
@@ -620,14 +629,19 @@ tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m,
 					tlen - sizeof(struct ip6_hdr));
 		ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb :
 		    NULL, NULL);
-	} else
+	}
 #endif /* INET6 */
+#if defined(INET6) && defined(INET)
+	else
+#endif
+#ifdef INET
 	{
 		nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
 		    htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p)));
 		m->m_pkthdr.csum_flags = CSUM_TCP;
 		m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
 	}
+#endif /* INET */
 #ifdef TCPDEBUG
 	if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG))
 		tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0);
@@ -635,9 +649,13 @@ tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m,
 #ifdef INET6
 	if (isipv6)
 		(void) ip6_output(m, NULL, NULL, ipflags, NULL, NULL, inp);
-	else
 #endif /* INET6 */
-	(void) ip_output(m, NULL, NULL, ipflags, NULL, inp);
+#if defined(INET) && defined(INET6)
+	else
+#endif
+#ifdef INET
+		(void) ip_output(m, NULL, NULL, ipflags, NULL, inp);
+#endif
 }
 
 /*
@@ -1200,6 +1218,7 @@ SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist,
     CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0,
     tcp_pcblist, "S,xtcpcb", "List of active TCP connections");
 
+#ifdef INET
 static int
 tcp_getcred(SYSCTL_HANDLER_ARGS)
 {
@@ -1239,6 +1258,7 @@ tcp_getcred(SYSCTL_HANDLER_ARGS)
 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred,
     CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
     tcp_getcred, "S,xucred", "Get the xucred of a TCP connection");
+#endif /* INET */
 
 #ifdef INET6
 static int
@@ -1247,7 +1267,10 @@ tcp6_getcred(SYSCTL_HANDLER_ARGS)
 	struct xucred xuc;
 	struct sockaddr_in6 addrs[2];
 	struct inpcb *inp;
-	int error, mapped = 0;
+	int error;
+#ifdef INET
+	int mapped = 0;
+#endif
 
 	error = priv_check(req->td, PRIV_NETINET_GETCRED);
 	if (error)
@@ -1260,13 +1283,16 @@ tcp6_getcred(SYSCTL_HANDLER_ARGS)
 		return (error);
 	}
 	if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) {
+#ifdef INET
 		if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr))
 			mapped = 1;
 		else
+#endif
 			return (EINVAL);
 	}
 
 	INP_INFO_RLOCK(&V_tcbinfo);
+#ifdef INET
 	if (mapped == 1)
 		inp = in_pcblookup_hash(&V_tcbinfo,
 			*(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12],
@@ -1275,6 +1301,7 @@ tcp6_getcred(SYSCTL_HANDLER_ARGS)
 			addrs[0].sin6_port,
 			0, NULL);
 	else
+#endif
 		inp = in6_pcblookup_hash(&V_tcbinfo,
 			&addrs[1].sin6_addr, addrs[1].sin6_port,
 			&addrs[0].sin6_addr, addrs[0].sin6_port, 0, NULL);
@@ -1300,9 +1327,10 @@ tcp6_getcred(SYSCTL_HANDLER_ARGS)
 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred,
     CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
     tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection");
-#endif
+#endif /* INET6 */
 
 
+#ifdef INET
 void
 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
 {
@@ -1415,6 +1443,7 @@ tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
 	} else
 		in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify);
 }
+#endif /* INET */
 
 #ifdef INET6
 void
@@ -1694,6 +1723,7 @@ tcp_mtudisc(struct inpcb *inp, int errno)
 	return (inp);
 }
 
+#ifdef INET
 /*
  * Look-up the routing entry to the peer of this inpcb.  If no route
  * is found and it cannot be allocated, then return 0.  This routine
@@ -1735,6 +1765,7 @@ tcp_maxmtu(struct in_conninfo *inc, int *flags)
 	}
 	return (maxmtu);
 }
+#endif /* INET */
 
 #ifdef INET6
 u_long
@@ -1858,11 +1889,15 @@ tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen,
     u_char *buf, u_int direction)
 {
 	union sockaddr_union dst;
+#ifdef INET
 	struct ippseudo ippseudo;
+#endif
 	MD5_CTX ctx;
 	int doff;
 	struct ip *ip;
+#ifdef INET
 	struct ipovly *ipovly;
+#endif
 	struct secasvar *sav;
 	struct tcphdr *th;
 #ifdef INET6
@@ -1884,12 +1919,14 @@ tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen,
 	ip6 = NULL;	/* Make the compiler happy. */
 #endif
 	switch (ip->ip_v) {
+#ifdef INET
 	case IPVERSION:
 		dst.sa.sa_len = sizeof(struct sockaddr_in);
 		dst.sa.sa_family = AF_INET;
 		dst.sin.sin_addr = (direction == IPSEC_DIR_INBOUND) ?
 		    ip->ip_src : ip->ip_dst;
 		break;
+#endif
 #ifdef INET6
 	case (IPV6_VERSION >> 4):
 		ip6 = mtod(m, struct ip6_hdr *);
@@ -1929,6 +1966,7 @@ tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen,
 	 * tcp_output(), the underlying ip_len member has not yet been set.
 	 */
 	switch (ip->ip_v) {
+#ifdef INET
 	case IPVERSION:
 		ipovly = (struct ipovly *)ip;
 		ippseudo.ippseudo_src = ipovly->ih_src;
@@ -1942,6 +1980,7 @@ tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen,
 		th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip));
 		doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen;
 		break;
+#endif
 #ifdef INET6
 	/*
 	 * RFC 2385, 2.0  Proposal
@@ -2122,6 +2161,7 @@ sysctl_drop(SYSCTL_HANDLER_ARGS)
 			return (error);
 		break;
 #endif
+#ifdef INET
 	case AF_INET:
 		fin = (struct sockaddr_in *)&addrs[0];
 		lin = (struct sockaddr_in *)&addrs[1];
@@ -2129,6 +2169,7 @@ sysctl_drop(SYSCTL_HANDLER_ARGS)
 		    lin->sin_len != sizeof(struct sockaddr_in))
 			return (EINVAL);
 		break;
+#endif
 	default:
 		return (EINVAL);
 	}
@@ -2141,10 +2182,12 @@ sysctl_drop(SYSCTL_HANDLER_ARGS)
 		    NULL);
 		break;
 #endif
+#ifdef INET
 	case AF_INET:
 		inp = in_pcblookup_hash(&V_tcbinfo, fin->sin_addr,
 		    fin->sin_port, lin->sin_addr, lin->sin_port, 0, NULL);
 		break;
+#endif
 	}
 	if (inp != NULL) {
 		INP_WLOCK(inp);
@@ -2272,6 +2315,7 @@ tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
 		sp = s + strlen(s);
 		sprintf(sp, "]:%i", ntohs(th->th_dport));
 #endif /* INET6 */
+#ifdef INET
 	} else if (ip && th) {
 		inet_ntoa_r(ip->ip_src, sp);
 		sp = s + strlen(s);
@@ -2280,6 +2324,7 @@ tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
 		inet_ntoa_r(ip->ip_dst, sp);
 		sp = s + strlen(s);
 		sprintf(sp, "]:%i", ntohs(th->th_dport));
+#endif /* INET */
 	} else {
 		free(s, M_TCPLOG);
 		return (NULL);
diff --git a/sys/netinet/tcp_syncache.c b/sys/netinet/tcp_syncache.c
index be828ef006b8..8262f43aa32e 100644
--- a/sys/netinet/tcp_syncache.c
+++ b/sys/netinet/tcp_syncache.c
@@ -742,8 +742,12 @@ syncache_socket(struct syncache *sc, struct socket *lso, struct mbuf *m)
 		/* Override flowlabel from in6_pcbconnect. */
 		inp->inp_flow &= ~IPV6_FLOWLABEL_MASK;
 		inp->inp_flow |= sc->sc_flowlabel;
-	} else
+	}
+#endif /* INET6 */
+#if defined(INET) && defined(INET6)
+	else
 #endif
+#ifdef INET
 	{
 		struct in_addr laddr;
 		struct sockaddr_in sin;
@@ -775,6 +779,7 @@ syncache_socket(struct syncache *sc, struct socket *lso, struct mbuf *m)
 			goto abort;
 		}
 	}
+#endif /* INET */
 	tp = intotcpcb(inp);
 	tp->t_state = TCPS_SYN_RECEIVED;
 	tp->iss = sc->sc_iss;
@@ -1067,7 +1072,11 @@ _syncache_add(struct in_conninfo *inc, struct tcpopt *to, struct tcphdr *th,
 #ifdef INET6
 	if (!(inc->inc_flags & INC_ISIPV6))
 #endif
+#ifdef INET
 		ipopts = (m) ? ip_srcroute(m) : NULL;
+#else
+		ipopts = NULL;
+#endif
 
 	/*
 	 * See if we already have an entry for this connection.
@@ -1301,8 +1310,8 @@ syncache_respond(struct syncache *sc)
 {
 	struct ip *ip = NULL;
 	struct mbuf *m;
-	struct tcphdr *th;
-	int optlen, error;
+	struct tcphdr *th = NULL;
+	int optlen, error = 0;	/* Make compiler happy */
 	u_int16_t hlen, tlen, mssopt;
 	struct tcpopt to;
 #ifdef INET6
@@ -1350,8 +1359,12 @@ syncache_respond(struct syncache *sc)
 		ip6->ip6_flow |= sc->sc_flowlabel;
 
 		th = (struct tcphdr *)(ip6 + 1);
-	} else
+	}
 #endif
+#if defined(INET6) && defined(INET)
+	else
+#endif
+#ifdef INET
 	{
 		ip = mtod(m, struct ip *);
 		ip->ip_v = IPVERSION;
@@ -1378,6 +1391,7 @@ syncache_respond(struct syncache *sc)
 
 		th = (struct tcphdr *)(ip + 1);
 	}
+#endif /* INET */
 	th->th_sport = sc->sc_inc.inc_lport;
 	th->th_dport = sc->sc_inc.inc_fport;
 
@@ -1445,8 +1459,12 @@ syncache_respond(struct syncache *sc)
 				       tlen + optlen - hlen);
 		ip6->ip6_hlim = in6_selecthlim(NULL, NULL);
 		error = ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL);
-	} else
+	}
 #endif
+#if defined(INET6) && defined(INET)
+	else
+#endif
+#ifdef INET
 	{
 		th->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
 		    htons(tlen + optlen - hlen + IPPROTO_TCP));
@@ -1454,6 +1472,7 @@ syncache_respond(struct syncache *sc)
 		m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
 		error = ip_output(m, sc->sc_ipopts, NULL, 0, NULL, NULL);
 	}
+#endif
 	return (error);
 }
 
diff --git a/sys/netinet/tcp_timewait.c b/sys/netinet/tcp_timewait.c
index aab950dab408..d283eb166da8 100644
--- a/sys/netinet/tcp_timewait.c
+++ b/sys/netinet/tcp_timewait.c
@@ -57,23 +57,19 @@ __FBSDID("$FreeBSD$");
 #include <net/vnet.h>
 
 #include <netinet/in.h>
+#include <netinet/in_pcb.h>
 #include <netinet/in_systm.h>
+#include <netinet/in_var.h>
 #include <netinet/ip.h>
+#include <netinet/ip_icmp.h>
+#include <netinet/ip_var.h>
 #ifdef INET6
 #include <netinet/ip6.h>
-#endif
-#include <netinet/in_pcb.h>
-#ifdef INET6
 #include <netinet6/in6_pcb.h>
-#endif
-#include <netinet/in_var.h>
-#include <netinet/ip_var.h>
-#ifdef INET6
 #include <netinet6/ip6_var.h>
 #include <netinet6/scope6_var.h>
 #include <netinet6/nd6.h>
 #endif
-#include <netinet/ip_icmp.h>
 #include <netinet/tcp.h>
 #include <netinet/tcp_fsm.h>
 #include <netinet/tcp_seq.h>
@@ -86,7 +82,9 @@ __FBSDID("$FreeBSD$");
 #ifdef TCPDEBUG
 #include <netinet/tcp_debug.h>
 #endif
+#ifdef INET6
 #include <netinet6/ip6protosw.h>
+#endif
 
 #include <machine/in_cksum.h>
 
@@ -202,15 +200,31 @@ tcp_twstart(struct tcpcb *tp)
 	struct inpcb *inp = tp->t_inpcb;
 	int acknow;
 	struct socket *so;
+#ifdef INET6
+	int isipv6 = inp->inp_inc.inc_flags & INC_ISIPV6;
+#endif
 
 	INP_INFO_WLOCK_ASSERT(&V_tcbinfo);	/* tcp_tw_2msl_reset(). */
 	INP_WLOCK_ASSERT(inp);
 
-	if (V_nolocaltimewait && in_localip(inp->inp_faddr)) {
-		tp = tcp_close(tp);
-		if (tp != NULL)
-			INP_WUNLOCK(inp);
-		return;
+	if (V_nolocaltimewait) {
+		int error = 0;
+#ifdef INET6
+		if (isipv6)
+			error = in6_localaddr(&inp->in6p_faddr);
+#endif
+#if defined(INET6) && defined(INET)
+		else
+#endif
+#ifdef INET
+			error = in_localip(inp->inp_faddr);
+#endif
+		if (error) {
+			tp = tcp_close(tp);
+			if (tp != NULL)
+				INP_WUNLOCK(inp);
+			return;
+		}
 	}
 
 	tw = uma_zalloc(V_tcptw_zone, M_NOWAIT);
@@ -488,11 +502,15 @@ int
 tcp_twrespond(struct tcptw *tw, int flags)
 {
 	struct inpcb *inp = tw->tw_inpcb;
-	struct tcphdr *th;
+#if defined(INET6) || defined(INET)
+	struct tcphdr *th = NULL;
+#endif
 	struct mbuf *m;
+#ifdef INET
 	struct ip *ip = NULL;
+#endif
 	u_int hdrlen, optlen;
-	int error;
+	int error = 0;			/* Keep compiler happy */
 	struct tcpopt to;
 #ifdef INET6
 	struct ip6_hdr *ip6 = NULL;
@@ -516,14 +534,19 @@ tcp_twrespond(struct tcptw *tw, int flags)
 		ip6 = mtod(m, struct ip6_hdr *);
 		th = (struct tcphdr *)(ip6 + 1);
 		tcpip_fillheaders(inp, ip6, th);
-	} else
+	}
 #endif
+#if defined(INET6) && defined(INET)
+	else
+#endif
+#ifdef INET
 	{
 		hdrlen = sizeof(struct tcpiphdr);
 		ip = mtod(m, struct ip *);
 		th = (struct tcphdr *)(ip + 1);
 		tcpip_fillheaders(inp, ip, th);
 	}
+#endif
 	to.to_flags = 0;
 
 	/*
@@ -555,8 +578,12 @@ tcp_twrespond(struct tcptw *tw, int flags)
 		ip6->ip6_hlim = in6_selecthlim(inp, NULL);
 		error = ip6_output(m, inp->in6p_outputopts, NULL,
 		    (tw->tw_so_options & SO_DONTROUTE), NULL, NULL, inp);
-	} else
+	}
 #endif
+#if defined(INET6) && defined(INET)
+	else
+#endif
+#ifdef INET
 	{
 		th->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
 		    htons(sizeof(struct tcphdr) + optlen + IPPROTO_TCP));
@@ -569,6 +596,7 @@ tcp_twrespond(struct tcptw *tw, int flags)
 		    ((tw->tw_so_options & SO_DONTROUTE) ? IP_ROUTETOIF : 0),
 		    NULL, inp);
 	}
+#endif
 	if (flags & TH_ACK)
 		TCPSTAT_INC(tcps_sndacks);
 	else
diff --git a/sys/netinet/tcp_usrreq.c b/sys/netinet/tcp_usrreq.c
index 6acf9dad83cd..318fe274a39d 100644
--- a/sys/netinet/tcp_usrreq.c
+++ b/sys/netinet/tcp_usrreq.c
@@ -64,17 +64,13 @@ __FBSDID("$FreeBSD$");
 
 #include <netinet/cc.h>
 #include <netinet/in.h>
-#include <netinet/in_systm.h>
-#ifdef INET6
-#include <netinet/ip6.h>
-#endif
 #include <netinet/in_pcb.h>
-#ifdef INET6
-#include <netinet6/in6_pcb.h>
-#endif
+#include <netinet/in_systm.h>
 #include <netinet/in_var.h>
 #include <netinet/ip_var.h>
 #ifdef INET6
+#include <netinet/ip6.h>
+#include <netinet6/in6_pcb.h>
 #include <netinet6/ip6_var.h>
 #include <netinet6/scope6_var.h>
 #endif
@@ -92,8 +88,10 @@ __FBSDID("$FreeBSD$");
  * TCP protocol interface to socket abstraction.
  */
 static int	tcp_attach(struct socket *);
+#ifdef INET
 static int	tcp_connect(struct tcpcb *, struct sockaddr *,
 		    struct thread *td);
+#endif /* INET */
 #ifdef INET6
 static int	tcp6_connect(struct tcpcb *, struct sockaddr *,
 		    struct thread *td);
@@ -229,6 +227,7 @@ tcp_usr_detach(struct socket *so)
 	INP_INFO_WUNLOCK(&V_tcbinfo);
 }
 
+#ifdef INET
 /*
  * Give the socket an address.
  */
@@ -270,6 +269,7 @@ out:
 
 	return (error);
 }
+#endif /* INET */
 
 #ifdef INET6
 static int
@@ -304,6 +304,7 @@ tcp6_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
 	TCPDEBUG1();
 	inp->inp_vflag &= ~INP_IPV4;
 	inp->inp_vflag |= INP_IPV6;
+#ifdef INET
 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6p->sin6_addr))
 			inp->inp_vflag |= INP_IPV4;
@@ -318,6 +319,7 @@ tcp6_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
 			goto out;
 		}
 	}
+#endif
 	error = in6_pcbbind(inp, nam, td->td_ucred);
 out:
 	TCPDEBUG2(PRU_BIND);
@@ -327,6 +329,7 @@ out:
 }
 #endif /* INET6 */
 
+#ifdef INET
 /*
  * Prepare to accept connections.
  */
@@ -365,6 +368,7 @@ out:
 	INP_INFO_WUNLOCK(&V_tcbinfo);
 	return (error);
 }
+#endif /* INET */
 
 #ifdef INET6
 static int
@@ -407,6 +411,7 @@ out:
 }
 #endif /* INET6 */
 
+#ifdef INET
 /*
  * Initiate connection to peer.
  * Create a template for use in transmissions on this connection.
@@ -454,6 +459,7 @@ out:
 	INP_INFO_WUNLOCK(&V_tcbinfo);
 	return (error);
 }
+#endif /* INET */
 
 #ifdef INET6
 static int
@@ -486,6 +492,7 @@ tcp6_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
 	}
 	tp = intotcpcb(inp);
 	TCPDEBUG1();
+#ifdef INET
 	if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
 		struct sockaddr_in sin;
 
@@ -505,6 +512,7 @@ tcp6_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
 		error = tcp_output_connect(so, nam);
 		goto out;
 	}
+#endif
 	inp->inp_vflag &= ~INP_IPV4;
 	inp->inp_vflag |= INP_IPV6;
 	inp->inp_inc.inc_flags |= INC_ISIPV6;
@@ -559,6 +567,7 @@ out:
 	return (error);
 }
 
+#ifdef INET
 /*
  * Accept a connection.  Essentially all the work is done at higher levels;
  * just return the address of the peer, storing through addr.
@@ -610,6 +619,7 @@ out:
 		*nam = in_sockaddr(port, &addr);
 	return error;
 }
+#endif /* INET */
 
 #ifdef INET6
 static int
@@ -799,9 +809,13 @@ tcp_usr_send(struct socket *so, int flags, struct mbuf *m,
 #ifdef INET6
 			if (isipv6)
 				error = tcp6_connect(tp, nam, td);
-			else
 #endif /* INET6 */
-			error = tcp_connect(tp, nam, td);
+#if defined(INET6) && defined(INET)
+			else
+#endif
+#ifdef INET
+				error = tcp_connect(tp, nam, td);
+#endif
 			if (error)
 				goto out;
 			tp->snd_wnd = TTCP_CLIENT_SND_WND;
@@ -859,9 +873,13 @@ tcp_usr_send(struct socket *so, int flags, struct mbuf *m,
 #ifdef INET6
 			if (isipv6)
 				error = tcp6_connect(tp, nam, td);
-			else
 #endif /* INET6 */
-			error = tcp_connect(tp, nam, td);
+#if defined(INET6) && defined(INET)
+			else
+#endif
+#ifdef INET
+				error = tcp_connect(tp, nam, td);
+#endif
 			if (error)
 				goto out;
 			tp->snd_wnd = TTCP_CLIENT_SND_WND;
@@ -1005,6 +1023,7 @@ out:
 	return (error);
 }
 
+#ifdef INET
 struct pr_usrreqs tcp_usrreqs = {
 	.pru_abort =		tcp_usr_abort,
 	.pru_accept =		tcp_usr_accept,
@@ -1024,6 +1043,7 @@ struct pr_usrreqs tcp_usrreqs = {
 	.pru_sosetlabel =	in_pcbsosetlabel,
 	.pru_close =		tcp_usr_close,
 };
+#endif /* INET */
 
 #ifdef INET6
 struct pr_usrreqs tcp6_usrreqs = {
@@ -1047,6 +1067,7 @@ struct pr_usrreqs tcp6_usrreqs = {
 };
 #endif /* INET6 */
 
+#ifdef INET
 /*
  * Common subroutine to open a TCP connection to remote host specified
  * by struct sockaddr_in in mbuf *nam.  Call in_pcbbind to assign a local
@@ -1109,6 +1130,7 @@ tcp_connect(struct tcpcb *tp, struct sockaddr *nam, struct thread *td)
 
 	return 0;
 }
+#endif /* INET */
 
 #ifdef INET6
 static int
@@ -1257,11 +1279,15 @@ tcp_ctloutput(struct socket *so, struct sockopt *sopt)
 		if (inp->inp_vflag & INP_IPV6PROTO) {
 			INP_WUNLOCK(inp);
 			error = ip6_ctloutput(so, sopt);
-		} else {
+		}
 #endif /* INET6 */
+#if defined(INET6) && defined(INET)
+		else
+#endif
+#ifdef INET
+		{
 			INP_WUNLOCK(inp);
 			error = ip_ctloutput(so, sopt);
-#ifdef INET6
 		}
 #endif
 		return (error);