chiark - git - jdamery - source-route-watch/blob - source-route-watch.sh

   1 #! /bin/bash
   2 set -ex
   3
   4 while true
   5 do
   6     stdbuf -oL ip monitor route | (
   7         while read X
   8         do
   9             read -t 1 -N 100000 || true # clear stdin
  10             for int in $( sed -n '/# local/,$ { /^[^#]/ s/.* // p }' /etc/iproute2/rt_tables )
  11             do
  12                 for proto in 4 6
  13                 do
  14                     tab=$(ip -"$proto" route list table "$int" match default |
  15                                  sed 's/\(dev [^ ]*\) .*/\1/')
  16                     def=$(ip -"$proto" route list match default |
  17                                  sed -n '/dev '"$int"'/ {
  18                                      s/\(dev [^ ]*\) .*/\1/
  19                                      p
  20                                      }')
  21                     if [ "x$def" != "x$tab" ]
  22                     then
  23                         ip -"$proto" route flush table "$int" || true
  24                         ip -"$proto" route add $def table "$int" || true
  25                         ip -"$proto" route add $(
  26                             ip -"$proto" route list proto kernel |
  27                                  sed -n '/dev '"$int"'/ {
  28                                      s/\(dev [^ ]*\) .*/\1/
  29                                      p
  30                                      q
  31                                      }'
  32                            ) table "$int" || true
  33                         ip -"$proto" rule del table "$int" || true
  34                         ip -"$proto" rule add from $(
  35                             ip -"$proto" addr show "$int" scope global | sed -n '
  36                              /inet/ {
  37                                  s/.*inet[^ ]* //
  38                                  s/ .*//
  39                                  p
  40                                  }') table "$int"
  41                     fi
  42                 done
  43             done
  44         done
  45     )
  46 done