From f79a420825479c47d064e40bc12d3a6755a64383 Mon Sep 17 00:00:00 2001 From: Peter Korsgaard Date: Mon, 21 Sep 2020 18:20:02 +0200 Subject: [PATCH] package/busybox/udhcpc.script: support RFC3442 static routes RFC3442 specifies a DHCP extension to provide the client with a list of static routes to use. This is already handled by udhcpc and exposed as the "staticroutes" environment variable, but currently not handled by the action script. Extend the script to do so. The RFC specifies that if this option is provided by the server then the normal "routes" (3) option should be ignored, so ensure that is done. As we may now have more than just a default route on the interface, extend the route cleanup logic to handle all routes for the interface (except for the implied local 0.0.0.0 one). Notice that this option is only sent by servers if explicitly requested by the client, E.G. using the -O staticroutes option to udhcpc. Signed-off-by: Peter Korsgaard Signed-off-by: Thomas Petazzoni --- package/busybox/udhcpc.script | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/package/busybox/udhcpc.script b/package/busybox/udhcpc.script index 0196351cd5..ec4d9f6185 100755 --- a/package/busybox/udhcpc.script +++ b/package/busybox/udhcpc.script @@ -61,7 +61,23 @@ case "$1" in wait_for_ipv6_default_route fi - if [ -n "$router" ] ; then + # RFC3442: If the DHCP server returns both a Classless + # Static Routes option and a Router option, the DHCP + # client MUST ignore the Router option. + if [ -n "$staticroutes" ]; then + echo "deleting routers" + route -n | while read dest gw mask flags metric ref use iface; do + [ "$iface" != "$interface" -o "$gw" = "0.0.0.0" ] || \ + route del -net "$dest" netmask "$mask" gw "$gw" dev "$interface" + done + + # format: dest1/mask gw1 ... destn/mask gwn + set -- $staticroutes + while [ -n "$1" -a -n "$2" ]; do + route add -net "$1" gw "$2" dev "$interface" + shift 2 + done + elif [ -n "$router" ] ; then echo "deleting routers" while route del default gw 0.0.0.0 dev $interface 2> /dev/null; do : -- 2.30.2