# 6in4.sh - IPv6-in-IPv4 tunnel backend
# Copyright (c) 2010 OpenWrt.org
+find_6in4_wanif() {
+ local if=$(ip -4 r l e 0/0); if="${if#default via * dev }"; if="${if%% *}"
+ [ -n "$if" ] && grep -qs "^ *$if:" /proc/net/dev && echo "$if"
+}
+
+find_6in4_wanip() {
+ local ip=$(ip -4 a s dev "$1"); ip="${ip#*inet }"
+ echo "${ip%%/[0-9]* brd *}"
+}
+
# Hook into scan_interfaces() to synthesize a .device option
# This is needed for /sbin/ifup to properly dispatch control
# to setup_interface_6in4() even if no .ifname is set in
local defaultroute
config_get_bool defaultroute "$cfg" defaultroute 1
+ # If local4 is unset, guess local IPv4 address from the
+ # interface used by the default route.
+ [ -z "$local4" ] && {
+ local wanif=$(find_6in4_wanif)
+ [ -n "$wanif" ] && {
+ local4=$(find_6in4_wanip "$wanif")
+ uci_set_state network "$cfg" wan_device "$wanif"
+ }
+ }
- # creating the tunnel below will trigger a net subsystem event
- # prevent it from touching or iface by disabling .auto here
- uci_set_state network "$cfg" ifname $link
- uci_set_state network "$cfg" auto 0
+ [ -n "$local4" ] && {
+ # creating the tunnel below will trigger a net subsystem event
+ # prevent it from touching or iface by disabling .auto here
+ uci_set_state network "$cfg" ifname $link
+ uci_set_state network "$cfg" auto 0
- ip tunnel add $link mode sit remote $remote4 local $local4 ttl 255
- ip link set $link up
- ip link set mtu ${mtu:-1280} dev $link
- ip tunnel change $link ttl ${ttl:-64}
- ip addr add $local6 dev $link
+ ip tunnel add $link mode sit remote $remote4 local $local4 ttl 255
+ ip link set $link up
+ ip link set mtu ${mtu:-1280} dev $link
+ ip tunnel change $link ttl ${ttl:-64}
+ ip addr add $local6 dev $link
- uci_set_state network "$cfg" ip6addr $local6
+ uci_set_state network "$cfg" ipaddr $local4
+ uci_set_state network "$cfg" ip6addr $local6
- [ "$defaultroute" = 1 ] && {
- ip -6 route add ::/0 dev $link
- uci_set_state network "$cfg" defaultroute 1
- }
+ [ "$defaultroute" = 1 ] && {
+ ip -6 route add ::/0 dev $link
+ uci_set_state network "$cfg" defaultroute 1
+ }
- env -i ACTION="ifup" INTERFACE="$cfg" DEVICE="$link" PROTO=6in4 /sbin/hotplug-call "iface" &
+ env -i ACTION="ifup" INTERFACE="$cfg" DEVICE="$link" PROTO=6in4 /sbin/hotplug-call "iface" &
+ } || {
+ echo "Cannot determine local IPv4 address for 6in4 tunnel $cfg - skipping"
+ }
}
stop_interface_6in4() {