#!/bin/sh
+# ip source routing ifupdown script
+# (C) 2015 Nirgal Vourgère
+# GPL-3+
+#
# This script set up source routing for a given interface
-# Argument $1: The gateway
+# Optionnal argument $1: The gateway. If missing, the interface gateway is required.
# Example usage: In /etc/network/interfaces
# iface eth7 inet static
# address 192.168.5.42/24
-# /root/source-route-via-v4 192.168.1.15
+# post-up source-route 192.168.1.1
+# or
+# iface eth7 inet static
+# address 192.168.5.42/24
+# gateway 192.168.5.1
+# post-up source-route
#set -x
-iface=$LOGICAL
-rttable=from$LOGICAL
-LOGGER="logger -t source-route-via"
+RTTABLE=from$IFACE
+LOGGER="logger -t source-route"
-$LOGGER -- IFACE=$IFACE LOGICAL=$LOGICAL ADDRFAM=$ADDRFAM METHOD=$METHOD MODE=$MODE PHASE=$PHASE VERBOSITY=$VERBOSITY PATH=$PATH
+if test "$VERBOSITY" = 1
+then
+ echo " IFACE=$IFACE LOGICAL=$LOGICAL ADDRFAM=$ADDRFAM METHOD=$METHOD MODE=$MODE PHASE=$PHASE VERBOSITY=$VERBOSITY PATH=$PATH" >&2
+ $LOGGER -- IFACE=$IFACE LOGICAL=$LOGICAL ADDRFAM=$ADDRFAM METHOD=$METHOD MODE=$MODE PHASE=$PHASE VERBOSITY=$VERBOSITY PATH=$PATH
+fi
+critical_log() {
+ $LOGGER -- "$@"
+ echo "$@" >&2
+}
if ! which ipv4calc >/dev/null
then
- echo ipv4calc not found: apt-get install libnetwork-ipv4addr-perl >&2
+ critical_log "ipv4calc not found: apt-get install libnetwork-ipv4addr-perl"
exit 2
fi
if ! which ipv6calc >/dev/null
then
- echo ipv6calc not found: apt-get install ipv6calc >&2
+ critical_log "ipv6calc not found: apt-get install ipv6calc"
exit 2
fi
-if test -z "$LOGICAL"
+if test -z "$IFACE"
then
- echo \$LOGICAL var is empty. >&2
+ critical_log "\$IFACE var is empty. Are you really running from /etc/network/interfaces ?"
exit 2
fi
if test "$PHASE" != "post-up"
then
- echo $0 is only valid in "post-up". >&2
- exit 2
-fi
-if test -z "$1"
-then
- echo Missing gateway parameter. >&2
+ critical_log "Invalid \$PHASE. $0 is only valid in 'post-up'."
exit 2
fi
RT_TABLES=/etc/iproute2/rt_tables
-if ! grep -q $rttable /etc/iproute2/rt_tables
+if ! grep -q $RTTABLE /etc/iproute2/rt_tables
then
- $LOGGER $RT_TABLES does not have $rttable entry.
- echo $RT_TABLES does not have $rttable entry. >&2
+ critical_log "$RT_TABLES does not have $RTTABLE entry."
exit 2
fi
IPFLAG=-6
;;
*)
- $LOGGER \$ADDRFAM must be inet or inet6. Ignoring.
+ echo \$ADDRFAM must be inet or inet6. Ignoring. >&2
exit 0
;;
esac
-IPADDR=$(ip $IPFLAG -o addr show $LOGICAL | grep -w $ADDRFAM | grep global | sed -re "s/.*$ADDRFAM (.*)\/.*/\1/")
-IPCIDR=$(ip -o addr show $LOGICAL | grep -w $ADDRFAM | grep global | sed -re "s/.*$ADDRFAM .*\/([^ ]*).*/\1/")
+IPADDR=$(ip $IPFLAG -o addr show $IFACE | grep -w $ADDRFAM | grep global | sed -re "s/.*$ADDRFAM (.*)\/.*/\1/")
+IPCIDR=$(ip $IPFLAG -o addr show $IFACE | grep -w $ADDRFAM | grep global | sed -re "s/.*$ADDRFAM .*\/([^ ]*).*/\1/")
if test "$ADDRFAM" = "inet6"
then
IPNET=$(ipv6calc --in ipv6 --out ipv6 --maskprefix $IPADDR/$IPCIDR)
else
IPNET=$(ipv4calc --network $IPADDR/$IPCIDR)/$IPCIDR
fi
-echo IP address: $IPADDR >&2
-echo CIDR: $IPCIDR >&2
-echo Network: $IPNET >&2
+if test -n "$1"
+then
+ IPGW=$1
+else
+ IPGW=$(ip $IPFLAG -o route show | grep default | sed -re "s/.*via ([^ ]*) .*/\1/")
+fi
+if test -z "$IPGW"
+then
+ critical_log "Could not find the gateway."
+ exit 2
+fi
+
+# Setting up source routing on $IFACE, so that packets from $IFACE don't get answered on another interface
+echo "Setting up source routing on $IFACE: from $IPADDR -> route $IPNET via $IPGW" >&2
+$LOGGER -- "Setting up source routing on $IFACE: from $IPADDR -> route $IPNET via $IPGW"
-# Setting up source routing on $iface, so that packets from $iface don't get answered on another interface
-if ! ip $IPFLAG route show table $rttable | grep -q default # Once only
+if ! ip $IPFLAG route show table $RTTABLE | grep -q default # Once only
then
- $LOGGER Setting up default gateway on iproute2 table $rttable
- $LOGGER -- ip $IPFLAG route add $IPNET dev "$iface" scope link table $rttable
- ip $IPFLAG route add $IPNET dev "$iface" scope link table $rttable
- $LOGGER -- ip $IPFLAG route add default via "$1" dev "$iface" table $rttable
- ip $IPFLAG route add default via "$1" dev "$iface" table $rttable
+ if test "$VERBOSITY" = 1
+ then
+ $LOGGER -- ip $IPFLAG route add $IPNET dev "$IFACE" scope link table $RTTABLE
+ $LOGGER -- ip $IPFLAG route add default via "$IPGW" dev "$IFACE" table $RTTABLE
+ fi
+ ip $IPFLAG route add $IPNET dev "$IFACE" scope link table $RTTABLE
+ ip $IPFLAG route add default via "$IPGW" dev "$IFACE" table $RTTABLE
fi
-if ! ip $IPFLAG rule show | grep -q $rttable # Once only
+if ! ip $IPFLAG rule show | grep -q $RTTABLE # Once only
then
- $LOGGER Setting up source routing on "$iface" from $IPADDR
- $LOGGER -- ip $IPFLAG rule add from $IPADDR table $rttable
- ip $IPFLAG rule add from $IPADDR table $rttable
+ if test "$VERBOSITY" = 1
+ then
+ $LOGGER -- ip $IPFLAG rule add from $IPADDR table $RTTABLE
+ fi
+ ip $IPFLAG rule add from $IPADDR table $RTTABLE
fi
ip $IPFLAG route flush cache