svn commit: r257755 - head/usr.sbin/bsdconfig/share/media

[Devin Teske]

Author: dteske
Date: Wed Nov  6 18:26:38 2013
New Revision: 257755
URL: http://svnweb.freebsd.org/changeset/base/257755

Log:
  Add support for dereferencing SRV records via f_host_lookup(). Takes the
  media choice into consideration for determining the appropriate SRV records
  to query (e.g., _http._tcp, _ftp._tcp, _nfs.tcp, _nfs.udp, etc.).

Modified:
  head/usr.sbin/bsdconfig/share/media/tcpip.subr

Modified: head/usr.sbin/bsdconfig/share/media/tcpip.subr
==============================================================================
--- head/usr.sbin/bsdconfig/share/media/tcpip.subr	Wed Nov  6 17:20:49 2013	(r257754)
+++ head/usr.sbin/bsdconfig/share/media/tcpip.subr	Wed Nov  6 18:26:38 2013	(r257755)
@@ -1020,10 +1020,41 @@ f_host_lookup()
 	# Fall back to host(1) -- which is further governed by nsswitch.conf(5)
 	#
 
-	local __output __ip6 __addrs="" __wait=""
-	f_getvar $VAR_MEDIA_TIMEOUT __wait
-	[ "$__wait" ] && __wait="-W $(( $__wait / 2 ))"
+	local __output __ip6 __addrs=
 	f_getvar $VAR_IPV6_ENABLE __ip6
+
+	# If we have a TCP media type configured, check for an SRV record
+	local __srvtypes=
+	{ f_quietly f_getvar $VAR_HTTP_PATH ||
+	  f_quietly f_getvar $VAR_HTTP_PROXY_PATH
+	} && __srvtypes="$__srvtypes _http._tcp"
+	f_quietly f_getvar $VAR_FTP_PATH && __srvtypes="$__srvtypes _ftp._tcp"
+	f_quietly f_getvar $VAR_NFS_PATH &&
+		__srvtypes="$__srvtypes _nfs._tcp _nfs._udp"
+
+	# Calculate wait time as dividend of total time and host(1) invocations
+	local __host_runs __wait
+	if [ "$__ip6" = "YES" ]; then
+		__host_runs=$(( 2 + $( set -- $__srvtypes; echo $# ) ))
+	else
+		__host_runs=$(( 1 + $( set -- $__srvtypes; echo $# ) ))
+	fi
+	f_getvar $VAR_MEDIA_TIMEOUT __wait
+	[ "$__wait" ] && __wait="-W $(( $__wait / $__host_runs ))"
+
+	# Query SRV types first (1st host response taken as new host to query)
+	for __type in $__srvtypes; do
+		if __output=$(
+			host -t SRV $__wait -- "$__type.$__host" \
+			2> /dev/null
+		); then
+			__host=$( echo "$__output" |
+					awk '/ SRV /{print $NF;exit}' )
+			break
+		fi
+	done
+
+	# Try IPv6 first (if enabled)
 	if [ "$__ip6" = "YES" ]; then
 		if ! __output=$( host -t AAAA $__wait -- "$__host" 2>&1 ); then
 			# An error occurred, display in-full and return error
@@ -1031,13 +1062,17 @@ f_host_lookup()
 				setvar "$__var_to_set" "$__output"
 			return $FAILURE
 		fi
+		# Add the IPv6 addresses and fall-through to collect IPv4 too
 		__addrs=$( echo "$__output" | awk '/ address /{print $NF}' )
 	fi
+
+	# Good ol' IPv4
 	if ! __output=$( host -t A $__wait -- "$__host" 2>&1 ); then
 		# An error occurred, display it in-full and return error
 		[ "$__var_to_set" ] && setvar "$__var_to_set" "$__output"
 		return $FAILURE
 	fi
+
 	__addrs="$__addrs${__addrs:+ }$(
 		echo "$__output" | awk '/ address /{print $NF}' )"
 	if [ "$__var_to_set" ]; then