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authorDenys Vlasenko <vda.linux@googlemail.com>2017-04-06 00:53:43 +0200
committerDenys Vlasenko <vda.linux@googlemail.com>2017-04-06 00:53:43 +0200
commit9c192e7f946a351c811e2278bbf56b4dc6a4b663 (patch)
treef5692f4976dbb828858545dc6990c70658429d37
parent19578b4edf84927705cab33b9e3d39645461c69b (diff)
downloadbusybox-9c192e7f946a351c811e2278bbf56b4dc6a4b663.tar.gz
examples: make udhcpc script handle /32 netmasks
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-rwxr-xr-xexamples/udhcp/sample.bound9
-rwxr-xr-xexamples/udhcp/sample.renew11
-rwxr-xr-xexamples/udhcp/simple.script10
3 files changed, 25 insertions, 5 deletions
diff --git a/examples/udhcp/sample.bound b/examples/udhcp/sample.bound
index 7c9d857e0..efd98cf15 100755
--- a/examples/udhcp/sample.bound
+++ b/examples/udhcp/sample.bound
@@ -18,11 +18,18 @@ then
metric=0
for i in $router
do
+ if [ "$subnet" = "255.255.255.255" ]; then
+ # special case for /32 subnets:
+ # /32 instructs kernel to always use routing for all outgoing packets
+ # (they can never be sent to local subnet - there is no local subnet for /32).
+ # Used in datacenters, avoids the need for private ip-addresses between two hops.
+ /sbin/ip route add $i dev $interface
+ fi
/sbin/route add default gw $i dev $interface metric $((metric++))
done
fi
-# Only replace resolv.conf is we have at least one DNS server
+# Only replace resolv.conf if we have at least one DNS server
if [ -n "$dns" ]
then
echo -n > $RESOLV_CONF
diff --git a/examples/udhcp/sample.renew b/examples/udhcp/sample.renew
index 4dce8486a..efd98cf15 100755
--- a/examples/udhcp/sample.renew
+++ b/examples/udhcp/sample.renew
@@ -1,5 +1,5 @@
#!/bin/sh
-# Sample udhcpc bound script
+# Sample udhcpc renew script
RESOLV_CONF="/etc/udhcpc/resolv.conf"
@@ -18,11 +18,18 @@ then
metric=0
for i in $router
do
+ if [ "$subnet" = "255.255.255.255" ]; then
+ # special case for /32 subnets:
+ # /32 instructs kernel to always use routing for all outgoing packets
+ # (they can never be sent to local subnet - there is no local subnet for /32).
+ # Used in datacenters, avoids the need for private ip-addresses between two hops.
+ /sbin/ip route add $i dev $interface
+ fi
/sbin/route add default gw $i dev $interface metric $((metric++))
done
fi
-# Only replace resolv.conf is we have at least one DNS server
+# Only replace resolv.conf if we have at least one DNS server
if [ -n "$dns" ]
then
echo -n > $RESOLV_CONF
diff --git a/examples/udhcp/simple.script b/examples/udhcp/simple.script
index 2a917eb6c..e4c1f2d76 100755
--- a/examples/udhcp/simple.script
+++ b/examples/udhcp/simple.script
@@ -29,8 +29,14 @@ case "$1" in
metric=0
for i in $router ; do
echo "Adding router $i"
- route add default gw $i dev $interface metric $metric
- : $(( metric += 1 ))
+ if [ "$subnet" = "255.255.255.255" ]; then
+ # special case for /32 subnets:
+ # /32 instructs kernel to always use routing for all outgoing packets
+ # (they can never be sent to local subnet - there is no local subnet for /32).
+ # Used in datacenters, avoids the need for private ip-addresses between two hops.
+ ip route add $i dev $interface
+ fi
+ route add default gw $i dev $interface metric $((metric++))
done
fi