* setlan2wan.sh

[lab.git] / iptables / setlan2wan.sh

diff --git a/iptables/setlan2wan.sh b/iptables/setlan2wan.sh
new file mode 100644 (file)
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--- /dev/null
+++ b/iptables/setlan2wan.sh
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+#!/bin/sh
+
+# enable access to WAN device on router node from LAN clients
+#
+
+set -x
+
+## INTERFACES(5)
+# IFACE  physical name of the interface being processed
+# METHOD method of the interface (e.g., static)
+# MODE   start if run from ifup, stop if run from ifdown
+# PHASE  as per MODE, but with finer granularity, distinguishing the pre-
+#        up, post-up, pre-down and post-down phases.
+
+LANIF="${1:?"usage: $0 <LAN_device> "}"
+
+LANIP=`/sbin/ip addr show dev ${LANIF} | grep -w inet | tr -s ' ' | cut -d ' ' -f 3 | cut -d / -f 1`
+LANMASK=`/sbin/ip route show dev ${LANIF} | grep -w ${LANIP} | tr -s ' ' | cut -d ' ' -f 1`
+
+WANIP=`/sbin/ip addr show dev ${IFACE} | grep -w inet | tr -s ' ' | cut -d ' ' -f 3 | cut -d / -f 1`
+
+if [ "${PHASE}" = "pre-down" ]; then
+    # delete rule and exit
+    /sbin/iptables -t nat -D PREROUTING -i ${LANIF} -s ${LANMASK} -d ${WANIP} -j DNAT --to-destination ${LANIP}
+    echo "remove rule for access to WAN device on router node from LAN clients"
+    exit
+fi
+
+
+# set rule
+/sbin/iptables -t nat -A PREROUTING -i ${LANIF} -s ${LANMASK} -d ${WANIP} -j DNAT --to-destination ${LANIP}
+echo "set rule for access to WAN device on router node from LAN clients"