lh | 0d3f4db | 2022-09-17 00:16:39 -0700 | [diff] [blame] | 1 | #!/bin/sh |
| 2 | # dns event handling script |
| 3 | # |
| 4 | |
| 5 | RESOLV_CONF="/etc/resolv.conf" |
| 6 | |
| 7 | usage() { |
| 8 | echo "Usage: $0 {set/clean} dns..." |
| 9 | exit 1 |
| 10 | } |
| 11 | |
| 12 | clean() { |
| 13 | # clean /etc/resolv.conf |
| 14 | cat /dev/null > $RESOLV_CONF |
| 15 | } |
| 16 | |
| 17 | show() { |
| 18 | cat $RESOLV_CONF |
| 19 | } |
| 20 | |
| 21 | takelock() |
| 22 | { |
| 23 | while [ -f "/tmp/dns_lock_fd" ]; do |
| 24 | : |
| 25 | echo "lock dns file now!" |
| 26 | sleep 1; |
| 27 | done |
| 28 | echo 1 > "/tmp/dns_lock_fd" |
| 29 | } |
| 30 | |
| 31 | givelock() |
| 32 | { |
| 33 | rm /tmp/dns_lock_fd |
| 34 | } |
| 35 | |
| 36 | |
| 37 | rmV4DNS(){ |
| 38 | cat /etc/resolv.conf | grep : > /var/dns6 |
| 39 | cat /var/dns6 > /etc/resolv.conf |
| 40 | } |
| 41 | |
| 42 | rmV6DNS(){ |
| 43 | cat /etc/resolv.conf | grep -v : > /var/dns4 |
| 44 | cat /var/dns4 > /etc/resolv.conf |
| 45 | } |
| 46 | |
| 47 | |
| 48 | count=1 |
| 49 | if [ $# \< $count ] ; then |
| 50 | usage |
| 51 | fi |
| 52 | |
| 53 | |
| 54 | |
| 55 | takelock; |
| 56 | case "$1" in |
| 57 | |
| 58 | set) |
| 59 | |
| 60 | rmV4DNS; |
| 61 | i=2 |
| 62 | total=$# |
| 63 | while [ $i -le $total ]; |
| 64 | do |
| 65 | shift |
| 66 | dns=$1 |
| 67 | echo "adding dns " $dns |
| 68 | echo nameserver "$dns" >> $RESOLV_CONF |
| 69 | i=`expr $i + 1` |
| 70 | done |
| 71 | show |
| 72 | ;; |
| 73 | |
| 74 | setv6) |
| 75 | |
| 76 | rmV6DNS; |
| 77 | i=2 |
| 78 | total=$# |
| 79 | while [ $i -le $total ]; |
| 80 | do |
| 81 | shift |
| 82 | dns=$1 |
| 83 | echo "adding dns " $dns |
| 84 | echo nameserver "$dns" >> $RESOLV_CONF |
| 85 | i=`expr $i + 1` |
| 86 | done |
| 87 | show |
| 88 | ;; |
| 89 | |
| 90 | |
| 91 | rmv4) |
| 92 | rmV4DNS |
| 93 | ;; |
| 94 | rmv6) |
| 95 | rmV6DNS |
| 96 | ;; |
| 97 | |
| 98 | |
| 99 | clean) |
| 100 | clean |
| 101 | ;; |
| 102 | |
| 103 | *) |
| 104 | usage |
| 105 | ;; |
| 106 | esac |
| 107 | givelock; |