From 9c192e7f946a351c811e2278bbf56b4dc6a4b663 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Thu, 6 Apr 2017 00:53:43 +0200 Subject: examples: make udhcpc script handle /32 netmasks Signed-off-by: Denys Vlasenko --- examples/udhcp/sample.bound | 9 ++++++++- examples/udhcp/sample.renew | 11 +++++++++-- examples/udhcp/simple.script | 10 ++++++++-- 3 files changed, 25 insertions(+), 5 deletions(-) (limited to 'examples/udhcp') 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 -- cgit v1.2.3