tinirc: Configure address selection policy

In case of IPv4-only, give IPv4 addresses the highest precedence,
in other cases (IPv6/dual-stack), prefer IPv6 addresses.

This fixes dual-stack tools like ping.

Only implemented for tinirc, as pots running standard rc run
these commands by default.

While there, add "wait for epair" also for IPv6 and private vnet
interfaces.

Fixes #203

CHANGELOG.md

@@ -24,6 +24,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ### Fixed
 - start: correct invocation of prestart and poststart hooks (#200)
+- tinirc: configure address selection policy (#205)
 
 ## [0.14.0] 2021-10-31
 ### Added

share/pot/start.sh

@@ -152,7 +152,6 @@ _js_vnet()
 	_ip=$( _get_ip_var "$_pname" )
 	## if norcscript - write a ad-hoc one
 	if [ "$(_get_conf_var "$_pname" "pot.attr.no-rc-script")" = "YES" ]; then
-		touch "${POT_FS_ROOT}/jails/$_pname/m/tmp/tinirc"
 		cat >>"${POT_FS_ROOT}/jails/$_pname/m/tmp/tinirc" <<-EOT
 		if ! ifconfig ${_epairb} >/dev/null 2>&1; then
 		    sleep 1
@@ -190,9 +189,17 @@ _js_vnet_ipv6()
 	ifconfig "${_epair}" up
 	ifconfig "$_bridge" addm "${_epair}"
 	if [ "$(_get_conf_var "$_pname" "pot.attr.no-rc-script")" = "YES" ]; then
-		touch "${POT_FS_ROOT}/jails/$_pname/m/tmp/tinirc"
-		echo "ifconfig ${_epairb} inet6 up accept_rtadv" >> "${POT_FS_ROOT}/jails/$_pname/m/tmp/tinirc"
-		echo "/sbin/rtsol -d ${_epairb}" >> "${POT_FS_ROOT}/jails/$_pname/m/tmp/tinirc"
+		cat >>"${POT_FS_ROOT}/jails/$_pname/m/tmp/tinirc" <<-EOT
+		if ! ifconfig ${_epairb} >/dev/null 2>&1; then
+		    sleep 1
+		    if ! ifconfig ${_epairb} >/dev/null 2>&1; then
+		        >&2 echo "Interface ${_epairb} does not exist"
+		        exit 1
+		    fi
+		fi
+		ifconfig ${_epairb} inet6 up accept_rtadv
+		/sbin/rtsol -d ${_epairb}
+		EOT
 	else # use rc scripts
 		# set the network configuration in the pot's rc.conf
 		if [ -w "${POT_FS_ROOT}/jails/$_pname/m/etc/rc.conf" ]; then
@@ -227,9 +234,17 @@ _js_private_vnet()
 	_gateway="$(_get_bridge_var "$_bridge_name" gateway)"
 	## if norcscript - write a ad-hoc one
 	if [ "$(_get_conf_var "$_pname" "pot.attr.no-rc-script")" = "YES" ]; then
-		touch "${POT_FS_ROOT}/jails/$_pname/m/tmp/tinirc"
-		echo "ifconfig ${_epairb} inet $_ip/$_net_size" >> "${POT_FS_ROOT}/jails/$_pname/m/tmp/tinirc"
-		echo "route add default $_gateway" >> "${POT_FS_ROOT}/jails/$_pname/m/tmp/tinirc"
+		cat >>"${POT_FS_ROOT}/jails/$_pname/m/tmp/tinirc" <<-EOT
+		if ! ifconfig ${_epairb} >/dev/null 2>&1; then
+		    sleep 1
+		    if ! ifconfig ${_epairb} >/dev/null 2>&1; then
+		        >&2 echo "Interface ${_epairb} does not exist"
+		        exit 1
+		    fi
+		fi
+		ifconfig ${_epairb} inet $_ip/$_net_size
+		route add default $_gateway
+		EOT
 	else # use rc scripts
 		# set the network configuration in the pot's rc.conf
 		if [ -w "${POT_FS_ROOT}/jails/$_pname/m/etc/rc.con"f ]; then
@@ -427,6 +442,29 @@ _js_start()
 	else
 		_param="$_param nopersist"
 	fi
+	if [ "$(_get_conf_var "$_pname" "pot.attr.no-rc-script")" = "YES" ]; then
+		if [ "$( _get_pot_network_stack "$_pname" )" = "ipv4" ]; then
+			prec=100
+		else
+			prec=35
+		fi
+		cat >>"${POT_FS_ROOT}/jails/$_pname/m/tmp/tinirc" <<-EOT
+		if sysctl -n kern.features.inet6 >/dev/null 2>&1; then
+		        ip6addrctl flush >/dev/null 2>&1
+		        ip6addrctl install /dev/stdin <<EOF
+		        ::1/128		 50	 0
+		        ::/0		 40	 1
+		        ::ffff:0:0/96	 $prec	 4
+		        2002::/16	 30	 2
+		        2001::/32	  5	 5
+		        fc00::/7	  3	13
+		        ::/96		  1	 3
+		        fec0::/10	  1	11
+		        3ffe::/16	  1	12
+		EOF
+		fi
+		EOT
+	fi
 	case "$( _get_conf_var "$_pname" network_type )" in
 	"inherit")
 		case "$( _get_pot_network_stack "$_pname" )" in