route-table-config

#!/usr/bin/env bash
## Helper to configure main or secondary route table
## This script expects a file 'ip-session-${ID}' with the following information (one per line):
##   IP=<IP>
##   NET=<IP network> (e.g. 192.168.2.0/24)
##   GW=<gateway address>
##   TABLE=<iproute2 table name or id> [optional]: If tablename is not provided, main table will be used
## usage: route-table-config [option]
##   -c <conf>   configuration file's relative path
##   -i <rmnet>  interface name (e.g. wwan0)
##   -r          restore default gateway configuration
##   -v          verbose [default: 0]
## This script requires that the secondary tables have already been added to /etc/iproute2/rt_tables
#
# 2016-12-06 Changelog
#   - arg3 is relative path to config file instead of the directory where the conf file is stored
# 2017-02-14
#   - netmask prefix is computed only if not provided in configuration file

_v=0
[ $# -eq 0 ] && sed -ne 's/^## \(.*\)/\1/p' $0 && exit 1
while getopts 'hc:i:rv' OPT; do
    case $OPT in
        h)
            sed -ne 's/^## \(.*\)/\1/p' $0
            exit 1
            ;;
        c)
            _conf=$OPTARG
            ;;
        i)
            _rmnet=$OPTARG
            ;;
        r)
            _r=1
            ;;
        v)
            _v=1
            ;;
        \?)
            echo "---"
            sed -ne 's/^## \(.*\)/\1/p' $0
            exit 1
            ;;
    esac
done

source qmi-lib
# exit at the first error
set -eu

source $_conf
TABLE=${TABLE-main}
MASK=${Mask-none}
reset=${_r-0}

# Debug
[ ! -z $_v ] && set -x

echo "Getting IP config from $_conf"

if [ $reset -eq 1 ]; then
  echo "Flushing current config"
  sudo ip rule flush
  # restoring default rule table
  sudo ip rule add priority 32766 lookup main
  sudo ip rule add priority 32767 lookup default

  sudo ip route flush table main
  sudo ip addr flush dev $_rmnet

  if [ $TABLE != "main" ]; then
    ip route flush table $TABLE
  fi
fi

sudo ip link set $_rmnet up
#if [ -z $PREFIX ]; then
#    PREFIX=$(mask2cdr $MASK)
#fi
sudo ip addr add $NET dev $_rmnet

if [ $TABLE = "main" ]; then
  sudo ip route add default via $GW dev $_rmnet proto static
else
  NET=$(ip route | grep $_rmnet | cut -d' ' -f1)
  sudo ip route add $NET dev $_rmnet src $IP table $TABLE
  sudo ip route add default via $GW dev $_rmnet table $TABLE proto static

  sudo ip rule add from $NET table $TABLE
  sudo ip rule add to $NET table $TABLE

  #sudo ip route flush cache
fi