!
! Make ftp work on IPv6-only hosts where we cannot open an IPv4
! socket to query buffer sizes.
!
! While here make it possible to compile ftp without INET as we
! seem to have supported to compile without INET6.  The result
! is not perfect but a start.
!
! Add FreeBSD specific feature_present(3) checks to allow a binary
! compiled with both IPv4 and IPv6 support to also work without
! troubles on INET only or INET6 only kernels.
!
! Reviewed by:
! Sponsored by: The FreeBSD Foundation
! Sponsored by: iXsystems
!
Index: usr.bin/ftp/Makefile
===================================================================
--- usr.bin/ftp/Makefile	(revision 222278)
+++ usr.bin/ftp/Makefile	(working copy)
@@ -18,6 +18,9 @@ SRCS=	cmds.c cmdtab.c complete.c domacro.c fetch.c
 .if ${MK_INET6_SUPPORT} != "no"
 CFLAGS+= -DINET6
 .endif
+.if ${MK_INET_SUPPORT} != "no"
+CFLAGS+= -DINET
+.endif
 
 CFLAGS+= -I${.CURDIR} -I${LUKEMFTP}
 LDADD=	-ledit -ltermcap -lutil
Index: contrib/lukemftp/src/main.c
===================================================================
--- contrib/lukemftp/src/main.c	(revision 222278)
+++ contrib/lukemftp/src/main.c	(working copy)
@@ -204,7 +204,23 @@ main(int argc, char *argv[])
 	 * call no socket buffer sizes will have been modified, so we are
 	 * guaranteed to get the system defaults.
 	 */
-	s = socket(AF_INET, SOCK_STREAM, 0);
+	s = -1;
+#ifdef INET6
+	if (s < 0
+#ifdef __FreeBSD__
+	    && feature_present("inet6")
+#endif
+	    )
+		s = socket(AF_INET6, SOCK_STREAM, 0);
+#endif /* INET6 */
+#ifdef INET
+	if (s < 0
+#ifdef __FreeBSD__
+	    && feature_present("inet")
+#endif
+	    )
+		s = socket(AF_INET, SOCK_STREAM, 0);
+#endif /* INET6 */
 	if (s == -1)
 		err(1, "can't create socket");
 	slen = sizeof(rcvbuf_size);
@@ -289,15 +305,33 @@ main(int argc, char *argv[])
 	while ((ch = getopt(argc, argv, "46AadefginN:o:pP:q:r:RtT:u:vV")) != -1) {
 		switch (ch) {
 		case '4':
+#ifdef INET
+#ifdef __FreeBSD__
+			if (feature_present("inet"))
+				family = AF_INET;
+			else
+				warnx("INET support is not available; ignoring -4");
+#else
 			family = AF_INET;
+#endif /* __FreeBSD__ */
+#else
+			warnx("INET support is not available; ignoring -4");
+#endif /* INET */
 			break;
 
 		case '6':
 #ifdef INET6
+#ifdef __FreeBSD__
+			if (feature_present("inet6"))
+				family = AF_INET6;
+			else
+				warnx("INET6 support is not available; ignoring -6");
+#else
 			family = AF_INET6;
+#endif /* __FreeBSD__ */
 #else
 			warnx("INET6 support is not available; ignoring -6");
-#endif
+#endif /* INET */
 			break;
 
 		case 'A':
Index: contrib/lukemftp/src/ftp.c
===================================================================
--- contrib/lukemftp/src/ftp.c	(revision 222278)
+++ contrib/lukemftp/src/ftp.c	(working copy)
@@ -141,7 +141,10 @@ static int empty(FILE *, FILE *, int);
 
 struct sockinet {
 	union sockunion {
+		struct sockaddr     su_sa;
+#ifdef INET
 		struct sockaddr_in  su_sin;
+#endif
 #ifdef INET6
 		struct sockaddr_in6 su_sin6;
 #endif
@@ -154,10 +157,18 @@ struct sockinet {
 #if !HAVE_SOCKADDR_SA_LEN
 # define su_len		si_len
 #else
-# define su_len		si_su.su_sin.sin_len
+# define su_len		si_su.su_sa.sa_len
+#endif /* !HAVE_SOCKADDR_SA_LEN */
+#define su_family	si_su.su_sa.sa_family
+#ifdef INET6
+#define su_port		si_su.su_sin6.sin6_port
+#else
+#ifdef INET
+#define su_port		si_su.su_sin.sin_port
+#else
+#error Need either INET6 or INET support.
 #endif
-#define su_family	si_su.su_sin.sin_family
-#define su_port		si_su.su_sin.sin_port
+#endif
 
 struct sockinet myctladdr, hisctladdr, data_addr;
 
@@ -1302,6 +1313,7 @@ initconn(void)
 		}
 		result = COMPLETE + 1;
 		switch (data_addr.su_family) {
+#ifdef INET
 		case AF_INET:
 			if (epsv4 && !epsv4bad) {
 				pasvcmd = "EPSV";
@@ -1333,6 +1345,7 @@ initconn(void)
 					return (1);
 			}
 			break;
+#endif
 #ifdef INET6
 		case AF_INET6:
 			pasvcmd = "EPSV";
@@ -1384,6 +1397,7 @@ initconn(void)
 		 * one-byte unsigned integer values, separated by commas.
 		 */
 		if (strcmp(pasvcmd, "PASV") == 0) {
+#ifdef INET
 			if (data_addr.su_family != AF_INET) {
 				fputs(
     "Passive mode AF mismatch. Shouldn't happen!\n", ttyout);
@@ -1412,6 +1426,12 @@ initconn(void)
 			data_addr.si_su.su_sin.sin_addr.s_addr =
 			    htonl(pack4(addr, 0));
 			data_addr.su_port = htons(pack2(port, 0));
+#else
+			fputs(
+    "Passive mode INET not supported. Shouldn't happen!\n", ttyout);
+			error = 1;
+			goto bad;
+#endif
 		} else if (strcmp(pasvcmd, "LPSV") == 0) {
 			if (code / 10 == 22 && code != 228) {
 				fputs("wrong server: return code must be 228\n",
@@ -1420,6 +1440,7 @@ initconn(void)
 				goto bad;
 			}
 			switch (data_addr.su_family) {
+#ifdef INET
 			case AF_INET:
 				error = sscanf(pasv,
 "%u,%u,%u,%u,%u,%u,%u,%u,%u",
@@ -1447,6 +1468,7 @@ initconn(void)
 				    htonl(pack4(addr, 0));
 				data_addr.su_port = htons(pack2(port, 0));
 				break;
+#endif
 #ifdef INET6
 			case AF_INET6:
 				error = sscanf(pasv,
@@ -1590,12 +1612,14 @@ initconn(void)
 		struct sockinet tmp;
 
 		switch (data_addr.su_family) {
+#ifdef INET
 		case AF_INET:
 			if (!epsv4 || epsv4bad) {
 				result = COMPLETE + 1;
 				break;
 			}
 			/* FALLTHROUGH */
+#endif
 #ifdef INET6
 		case AF_INET6:
 #endif
@@ -1631,6 +1655,7 @@ initconn(void)
 			goto skip_port;
 
 		switch (data_addr.su_family) {
+#ifdef INET
 		case AF_INET:
 			a = (char *)&data_addr.si_su.su_sin.sin_addr;
 			p = (char *)&data_addr.su_port;
@@ -1638,6 +1663,7 @@ initconn(void)
 				 UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]),
 				 UC(p[0]), UC(p[1]));
 			break;
+#endif
 #ifdef INET6
 		case AF_INET6:
 			a = (char *)&data_addr.si_su.su_sin6.sin6_addr;