diff options
Diffstat (limited to 'roles/common/files')
| -rwxr-xr-x | roles/common/files/usr/local/sbin/update-firewall.sh | 104 |
1 files changed, 80 insertions, 24 deletions
diff --git a/roles/common/files/usr/local/sbin/update-firewall.sh b/roles/common/files/usr/local/sbin/update-firewall.sh index cefeea5..8840174 100755 --- a/roles/common/files/usr/local/sbin/update-firewall.sh +++ b/roles/common/files/usr/local/sbin/update-firewall.sh @@ -1,10 +1,14 @@ #!/bin/bash # -# Create iptables (v4 and v6) rules. Unless [-f] is given, a -# confirmation is asked after loading the new rulesets; if the user -# answers No or doesn't answer, the old ruleset is restored. If the user -# answer Yes (or if the flag [-f] is given), the new ruleset is made -# persistent using iptables-persistent. +# Create iptables (v4 and v6) rules. Unless one of [-f] or [-c] is +# given, a confirmation is asked after loading the new rulesets; if the +# user answers No or doesn't answer, the old ruleset is restored. If the +# user answer Yes (or if the flag [-f] is given), the new ruleset is +# made persistent using iptables-persistent. +# +# The [-c] flag switch to dry-run (check) mode. The rulesets are not +# applied, but merely checked against the existing ones. If they differ +# the return value is one, and 0 otherwise. # # This firewall is only targeted towards end-servers, not gateways. In # particular, there is no NAT'ing at the moment. @@ -21,6 +25,19 @@ PATH=/usr/sbin:/usr/bin:/sbin:/bin timeout=10 force=0 +check=0 + +usage() { + echo "Usage: $0 [-c|-f]" >&2 + exit 1 +} + +[ $# -le 1 ] || usage +case "${1:-}" in + -f) force=1;; + -c) check=1;; + ?*) usage +esac [ "${1:-}" = -f ] && force=1 if ! /usr/bin/tty -s && [ $force -eq 0 ]; then @@ -58,6 +75,30 @@ fatal() { /usr/bin/logger -st firewall -p syslog.err -- "$@" exit 1 } +save() { + mkdir -p /etc/iptables + /sbin/iptables-save > /etc/iptables/rules.v4 + /sbin/ip6tables-save > /etc/iptables/rules.v6 + + # Ignore the counters + sed -ri 's/^(:.*)\[[0-9]+:[0-9]+\]$/\1[0:0]/' \ + /etc/iptables/rules.v4 /etc/iptables/rules.v6 +} +iptdiff() { + local v="$1" old="$2" new="$3" rv1=0 rv2=0 + + diff -qI '^#' "$old" "$new" >/dev/null || rv1=$? + if [ -f /etc/iptables/rules.$v ]; then + diff -qI '^#' "$old" /etc/iptables/rules.$v >/dev/null || rv2=$? + else + rv2=1 + fi + + [ $rv1 -eq 0 ] || log "WARN: The IP$v firewall is not up to date! Please run '$0'." + [ $rv2 -eq 0 ] || log "WARN: The current IP$v firewall is not persistent! Please run '$0'." + + return $(( $rv1 | $rv2 )) +} [ -n "$WAN" -o -n "$WAN6" ] || fatal "Error: couldn't find a network interface" @@ -106,14 +147,14 @@ if [ -n "$WAN" ]; then [ -n "$MyNetwork" ] && \ for ip in 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16 169.254.0.0/16; do [ "$ip" = "$(/usr/bin/netmask -nc $ip $MyNetwork | sed 's/ //g')" ] \ - || iptables -A INPUT -i $WAN -s "$ip" -j DROP + || iptables -A INPUT -i $WAN -s "$ip" -j DROP done # Other martian packets: "This" network, multicast, broadcast (RFCs # 1122, 3171 and 919). for ip in 0.0.0.0/8 224.0.0.0/4 240.0.0.0/4 255.255.255.255/32; do - iptables -A INPUT -i $WAN -s "$ip" -j DROP - iptables -A INPUT -i $WAN -d "$ip" -j DROP + iptables -A INPUT -i $WAN -s "$ip" -j DROP + iptables -A INPUT -i $WAN -d "$ip" -j DROP done fi @@ -121,8 +162,8 @@ fi # 3879). for ip6 in fc00::/7 fec0::/10 do - ip6tables -A INPUT -i $WAN6 -s "$ip6" -j DROP - ip6tables -A INPUT -i $WAN6 -d "$ip6" -j DROP + ip6tables -A INPUT -i $WAN6 -s "$ip6" -j DROP + ip6tables -A INPUT -i $WAN6 -d "$ip6" -j DROP done @@ -134,7 +175,7 @@ done # DROP bogus TCP packets. -iptables -A INPUT -p tcp -m tcp --tcp-flags SYN,FIN SYN,FIN -j DROP +iptables -A INPUT -p tcp -m tcp --tcp-flags FIN,SYN FIN,SYN -j DROP iptables -A INPUT -p tcp -m tcp --tcp-flags SYN,RST SYN,RST -j DROP ip6tables -A INPUT -p tcp -m tcp --tcp-flags SYN,FIN SYN,FIN -j DROP @@ -142,11 +183,11 @@ ip6tables -A INPUT -p tcp -m tcp --tcp-flags SYN,RST SYN,RST -j DROP # Allow all input/output to/from the loopback interface. -iptables -A INPUT -i lo -s 127.0.0.1 -d 127.0.0.1 -j ACCEPT -iptables -A OUTPUT -o lo -s 127.0.0.1 -d 127.0.0.1 -j ACCEPT +iptables -A INPUT -i lo -s 127.0.0.1/32 -d 127.0.0.1/32 -j ACCEPT +iptables -A OUTPUT -o lo -s 127.0.0.1/32 -d 127.0.0.1/32 -j ACCEPT -ip6tables -A INPUT -i lo -s ::1 -d ::1 -j ACCEPT -ip6tables -A OUTPUT -o lo -s ::1 -d ::1 -j ACCEPT +ip6tables -A INPUT -i lo -s ::1/128 -d ::1/128 lo -j ACCEPT +ip6tables -A OUTPUT -o lo -s ::1/128 -d ::1/128 lo -j ACCEPT # Allow only ICMP of type 0, 3 and 8. The rate-limiting is done directly @@ -172,7 +213,7 @@ while read dir proto dport sport; do stEst=ESTABLISHED # In-Out means full-duplex - [[ "$dir" =~ inout ]] && stEst="$stNew" + [[ "$dir" =~ ^inout ]] && stEst="$stNew" optsNew= optsEst= @@ -211,17 +252,32 @@ tgrep '^-[AI] fail2ban-\S+ ' echo COMMIT >> "$newv4table" echo COMMIT >> "$newv6table" -/usr/bin/uniq "$newv4table" | /sbin/iptables-restore -/usr/bin/uniq "$newv6table" | /sbin/ip6tables-restore +netns= +innetns= +if [ $check -eq 1 ]; then + # Create an alternative net namespace in which we apply the ruleset, + # so we can easily get a normalized version we can compare latter. + # See http://bugzilla.netfilter.org/show_bug.cgi?id=790 + netns="ipt-firewall-test-$$" + /bin/ip netns add $netns + innetns="/bin/ip netns exec $netns" +fi -save() { - mkdir -p /etc/iptables - /sbin/iptables-save > /etc/iptables/rules.v4 - /sbin/ip6tables-save > /etc/iptables/rules.v6 -} +/usr/bin/uniq "$newv4table" | $innetns /sbin/iptables-restore +/usr/bin/uniq "$newv6table" | $innetns /sbin/ip6tables-restore rv=0 -if [ $force -eq 1 ]; then +if [ $check -eq 1 ]; then + $innetns /sbin/iptables-save > "$newv4table" + $innetns /sbin/ip6tables-save > "$newv6table" + /bin/ip netns del $netns + + # Reset the counters, they are not relevant here + sed -ri 's/^(:.*)\[[0-9]+:[0-9]+\]$/\1[0:0]/' "$oldv4table" "$oldv6table" + iptdiff v4 "$oldv4table" "$newv4table" || rv=$(( $rv | $? )) + iptdiff v6 "$oldv6table" "$newv6table" || rv=$(( $rv | $? )) + +elif [ $force -eq 1 ]; then # At the user's own risks... save else |