| 1 | #! /bin/bash |
| 2 | |
| 3 | set -e |
| 4 | |
| 5 | PATH="/sbin:$PATH" |
| 6 | |
| 7 | DIR_CFG="/home/siraaj/etc/mypeetables" |
| 8 | FILE_HOSTS_BLACKLIST="$DIR_CFG/hosts_blacklist" |
| 9 | FILE_PORTS_OPEN="$DIR_CFG/ports_open" |
| 10 | |
| 11 | set_policy__accept() { |
| 12 | iptables -P INPUT ACCEPT |
| 13 | iptables -P OUTPUT ACCEPT |
| 14 | iptables -P FORWARD ACCEPT |
| 15 | } |
| 16 | |
| 17 | set_policy__drop() { |
| 18 | iptables -P INPUT DROP |
| 19 | iptables -P OUTPUT DROP |
| 20 | iptables -P FORWARD DROP |
| 21 | } |
| 22 | |
| 23 | flush() { |
| 24 | iptables -F |
| 25 | iptables -X |
| 26 | iptables -t nat -F |
| 27 | iptables -t nat -X |
| 28 | iptables -t mangle -F |
| 29 | iptables -t mangle -X |
| 30 | |
| 31 | set_policy__accept |
| 32 | } |
| 33 | |
| 34 | drop_offenders() { |
| 35 | cat "$FILE_HOSTS_BLACKLIST" \ |
| 36 | | grep -v '^#' \ |
| 37 | | grep -v '^ *$' \ |
| 38 | | while read addr; do |
| 39 | iptables -A INPUT -s "$addr" -j DROP |
| 40 | done |
| 41 | } |
| 42 | |
| 43 | accept() { |
| 44 | # accept established connections |
| 45 | iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT |
| 46 | iptables -A OUTPUT -m state --state ESTABLISHED,RELATED -j ACCEPT |
| 47 | iptables -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT |
| 48 | |
| 49 | # accept all traffic on loopback inteface |
| 50 | iptables -A INPUT -i lo -j ACCEPT |
| 51 | iptables -A OUTPUT -o lo -j ACCEPT |
| 52 | |
| 53 | # accept outgoing connections |
| 54 | iptables -A INPUT -s $(hostname) -m state --state NEW -j ACCEPT |
| 55 | iptables -A OUTPUT -m state --state NEW -j ACCEPT |
| 56 | |
| 57 | # accept icmp |
| 58 | #iptables -A INPUT -p icmp -j ACCEPT |
| 59 | |
| 60 | # Services |
| 61 | cat "$FILE_PORTS_OPEN" \ |
| 62 | | grep -v '^#' \ |
| 63 | | grep -v '^ *$' \ |
| 64 | | while read port protocol; do |
| 65 | iptables \ |
| 66 | -A INPUT \ |
| 67 | -m state \ |
| 68 | --state NEW \ |
| 69 | -p "$protocol" \ |
| 70 | -m "$protocol" \ |
| 71 | --dport "$port" \ |
| 72 | -j ACCEPT |
| 73 | done |
| 74 | |
| 75 | |
| 76 | } |
| 77 | |
| 78 | reject() { |
| 79 | iptables -A INPUT -j NFLOG |
| 80 | iptables -A FORWARD -j NFLOG |
| 81 | #iptables -A INPUT -j REJECT --reject-with icmp-host-prohibited |
| 82 | #iptables -A FORWARD -j REJECT --reject-with icmp-host-prohibited |
| 83 | } |
| 84 | |
| 85 | command_off() { |
| 86 | flush |
| 87 | } |
| 88 | |
| 89 | command_on() { |
| 90 | flush |
| 91 | set_policy__drop |
| 92 | accept |
| 93 | drop_offenders |
| 94 | reject |
| 95 | } |
| 96 | |
| 97 | failwith() { |
| 98 | error_msg="$1" |
| 99 | echo "$error_msg" >&2 |
| 100 | exit 1 |
| 101 | } |
| 102 | |
| 103 | main() { |
| 104 | command="$1" |
| 105 | case "$command" |
| 106 | in 'on' ) command_on |
| 107 | ;; 'off' ) command_off |
| 108 | ;; * ) failwith "Error: Unknown command: \"$command\". Known: on, off." |
| 109 | esac |
| 110 | } |
| 111 | |
| 112 | main "$@" |