diff options
Diffstat (limited to 'roles/common/files/usr/local/sbin/update-firewall.sh')
| -rwxr-xr-x | roles/common/files/usr/local/sbin/update-firewall.sh | 445 |
1 files changed, 0 insertions, 445 deletions
diff --git a/roles/common/files/usr/local/sbin/update-firewall.sh b/roles/common/files/usr/local/sbin/update-firewall.sh deleted file mode 100755 index 8ef3ab9..0000000 --- a/roles/common/files/usr/local/sbin/update-firewall.sh +++ /dev/null @@ -1,445 +0,0 @@ -#!/bin/bash - -# Create iptables (v4 and v6) rules. Unless one of [-f] or [-c] is -# given, or if the ruleset is unchanged, 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 (requires a pre-up -# hook) by moving it to /etc/iptables/rules.v[46]. -# -# The [-c] flag switch to dry-run (check) mode. The rulesets are not -# applied, but merely checked against the existing ones. The return -# value is 0 iff. they do not differ. -# -# This firewall is only targeted towards end-servers, not gateways. In -# particular, there is no NAT'ing at the moment. -# -# Dependencies: netmask(1) -# -# Copyright © 2013 Guilhem Moulin <guilhem@fripost.org> -# -# This program is free software: you can redistribute it and/or modify -# it under the terms of the GNU General Public License as published by -# the Free Software Foundation, either version 3 of the License, or -# (at your option) any later version. -# -# This program is distributed in the hope that it will be useful, -# but WITHOUT ANY WARRANTY; without even the implied warranty of -# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -# GNU General Public License for more details. -# -# You should have received a copy of the GNU General Public License -# along with this program. If not, see <http://www.gnu.org/licenses/>. - -set -ue -PATH=/usr/sbin:/usr/bin:/sbin:/bin -timeout=10 - -force=0 -check=0 -verbose=0 -addrfam= - -secproto=esp # must match /etc/ipsec.conf; ESP is the default (vs AH/IPComp) -if [ -x /usr/sbin/ipsec ] && /usr/sbin/ipsec status >/dev/null; then - ipsec=y -else - ipsec=n -fi - -fail2ban_re='^(\[[0-9]+:[0-9]+\]\s+)?-A f2b-\S' -IPsec_re=" -m policy --dir (in|out) --pol ipsec --reqid [0-9]+ --proto $secproto -j ACCEPT$" -declare -A rss=() tables=() - -usage() { - cat >&2 <<- EOF - Usage: $0 [OPTIONS] - - Options: - -f force: no confirmation asked - -c check: check (dry-run) mode - -v verbose: see the difference between old and new ruleset - -4 IPv4 only - -6 IPv6 only - EOF - exit 1 -} - -log() { - logger -st firewall -p user.info -- "$@" -} -fatal() { - logger -st firewall -p user.err -- "$@" - exit 1 -} - -iptables() { - # Fake iptables/ip6tables(8); use the more efficient - # iptables-restore(8) instead. - echo "$@" >>"$new"; -} -commit() { - # End a table - echo COMMIT >>"$new" -} -inet46() { - case "$1" in - 4) echo "$2";; - 6) echo "$3";; - esac -} -ipt-chains() { - # Define new (tables and) chains. - while [ $# -gt 0 ]; do - case "$1" in - ?*:*) echo ":${1%:*} ${1##*:} [0:0]";; - ?*) echo "*$1";; - esac - shift - done >>"$new" -} - -ipt-trim() { - # Remove dynamic chain/rules from the input stream, as they are - # automatically included by third-party servers (such as strongSwan - # or fail2ban). The output is ready to be made persistent. - grep -Ev -e '^:f2b-\S' \ - -e "$IPsec_re" \ - -e '-j f2b-\S+$' \ - -e "$fail2ban_re" -} - -ipt-diff() { - # Get the difference between two rulesets. - if [ $verbose -eq 1 ]; then - diff -u -I '^#' --color=auto "$@" - else - diff -q -I '^#' "$@" >/dev/null - fi -} - -ipt-persist() { - # Make the current ruleset persistent. (Requires a pre-up hook - # script to load the rules before the network is configured.) - - log "Making ruleset persistent... " - [ -d /etc/iptables ] || mkdir /etc/iptables - - local f rs table - for f in "${!tables[@]}"; do - ipts=$(inet46 $f iptables ip6tables)-save - rs=/etc/iptables/rules.v$f - - for table in ${tables[$f]}; do - ip netns exec $netns $ipts -t $table - done | ipt-trim >"$rs" - chmod 0600 "$rs" - done -} - -ipt-revert() { - [ $check -eq 0 ] || return - log "Reverting to old ruleset... " - - local rs - for f in "${!rss[@]}"; do - $(inet46 $f iptables ip6tables)-restore -c <"${rss[$f]}" - rm -f "${rss[$f]}" - done - exit 1 -} - -run() { - # Build and apply the firewall for IPv4/6. - local f="$1" - local ipt=$(inet46 $f iptables ip6tables) - tables[$f]=filter - - # The default interface associated with this address. - local if=$( /bin/ip -$f -o route show to default scope global \ - | sed -nr '/^default via \S+ dev (\S+).*/ {s//\1/p;q}' ) - - # Store the old (current) ruleset - local old=$(mktemp --tmpdir current-rules.v$f.XXXXXX) \ - new=$(mktemp --tmpdir new-rules.v$f.XXXXXX) - for table in ${tables[$f]}; do - $ipt-save -ct $table - done >"$old" - rss[$f]="$old" - - local fail2ban=0 - # XXX: As of Wheezy, fail2ban is IPv4 only. See - # https://github.com/fail2ban/fail2ban/issues/39 for the current - # state of the art. - if [ "$f" = 4 ] && which fail2ban-server >/dev/null; then - fail2ban=1 - fi - - # The usual chains in filter, along with the desired default policies. - ipt-chains filter INPUT:DROP FORWARD:DROP OUTPUT:DROP - - if [ ! "$if" ]; then - # If the interface is not configured, we stop here and DROP all - # packets by default. Thanks to the pre-up hook this tight - # policy will be activated whenever the interface goes up. - commit - mv "$new" /etc/iptables/rules.v$f - return 0 - fi - - # Fail2ban-specific chains and traps - if [ $fail2ban -eq 1 ]; then - echo ":fail2ban - [0:0]" - # Don't remove existing rules & traps in the current rulest - grep -- '^:f2b-\S' "$old" || true - grep -E -- ' -j f2b-\S+$' "$old" || true - grep -E -- "$fail2ban_re" "$old" || true - fi >>"$new" - - if [ "$f" = 4 -o "$f" = 6 ] && [ "$ipsec" = y ]; then - # IPsec tunnels come first (IPv4 only). - grep -E -- "$IPsec_re" "$old" >>"$new" || true - - # Allow any IPsec $secproto protocol packets to be sent and received. - iptables -A INPUT -i $if -p $secproto -j ACCEPT - iptables -A OUTPUT -o $if -p $secproto -j ACCEPT - fi - - - ######################################################################## - # DROP all RFC1918 addresses, martian networks, multicasts, ... - # Credits to http://newartisans.com/2007/09/neat-tricks-with-iptables/ - # http://baldric.net/loose-iptables-firewall-for-servers/ - - local ip - if [ "$f" = 4 ] && [ "$ipsec" = y ]; then - # Private-use networks (RFC 1918) and link local (RFC 3927) - local MyIPsec="$( ip -4 -o route show table 220 dev $if | sed 's/\s.*//' )" - local MyNetwork="$( ip -4 -o address show dev $if scope global \ - | sed -nr "s/^[0-9]+:\s+$if\s+inet\s(\S+).*/\1/p" \ - | while read ip; do - for ips in $MyIPsec; do - [ "$ips" = "$(netmask -nc "$ip" "$ips" | sed 's/^ *//')" ] || echo "$ip" - done - done - )" - [ "$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 - # Don't lock us out if we are behind a NAT ;-) - for myip in $MyNetwork; do - [ "$ip" = "$(netmask -nc "$ip" "$myip" | sed 's/^ *//')" ] || echo "$ip" - done | uniq | while read ip; do iptables -A INPUT -i $if -s "$ip" -j DROP; done - 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 $if -s "$ip" -j DROP - iptables -A INPUT -i $if -d "$ip" -j DROP - done - - elif [ "$f" = 6 ]; then - # Martian IPv6 packets: ULA (RFC 4193) and site local addresses - # (RFC 3879). - for ip in fc00::/7 fec0::/10; do - iptables -A INPUT -i $if -s "$ip" -j DROP - iptables -A INPUT -i $if -d "$ip" -j DROP - done - fi - - # DROP INVALID packets immediately. - iptables -A INPUT -m state --state INVALID -j DROP - iptables -A OUTPUT -m state --state INVALID -j DROP - - # DROP bogus TCP packets. - 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 - iptables -A INPUT -p tcp \! --syn -m state --state NEW -j REJECT --reject-with tcp-reset - - # Allow all input/output to/from the loopback interface. - local localhost=$(inet46 $f '127.0.0.1/8' '::1/128') - iptables -A INPUT -i lo -s "$localhost" -d "$localhost" -j ACCEPT - iptables -A OUTPUT -o lo -s "$localhost" -d "$localhost" -j ACCEPT - if [ "$f" = 4 ] && [ "$ipsec" = y ]; then - # Allow local access to our virtual IP - ip -4 -o route show table 220 dev $if \ - | sed -nr 's/.*\ssrc\s+([[:digit:].]{7,15})(\s.*)?$/\1/p' \ - | while read ips; do - iptables -A INPUT -i lo -s "$ips" -d "$ips" -j ACCEPT - iptables -A OUTPUT -o lo -s "$ips" -d "$ips" -j ACCEPT - done - fi - - # Prepare fail2ban. We make fail2ban insert its rules in a - # dedicated chain, so that it doesn't mess up the existing rules. - [ $fail2ban -eq 1 ] && iptables -A INPUT -i $if -j fail2ban - - if [ "$f" = 4 ]; then - # Allow only ICMP of type 0, 3 and 8. The rate-limiting is done - # directly by the kernel (net.ipv4.icmp_ratelimit and - # net.ipv4.icmp_ratemask runtime options). See icmp(7). - local t - for t in 'echo-reply' 'destination-unreachable' 'echo-request'; do - iptables -A INPUT -p icmp -m icmp --icmp-type $t -j ACCEPT - iptables -A OUTPUT -p icmp -m icmp --icmp-type $t -j ACCEPT - done - elif [ $f = 6 ]; then - iptables -A INPUT -p icmpv6 -j ACCEPT - iptables -A OUTPUT -p icmpv6 -j ACCEPT - fi - - - ######################################################################## - # ACCEPT new connections to the services we provide, or to those we want - # to connect to. - - sed -re 's/#.*//; /^\s*$/d' -e "s/^(in|out|inout)$f?(\s.*)/\1\2/" \ - /etc/iptables/services | \ - grep -Ev '^(in|out|inout)\S\s' | \ - while read dir proto dport sport; do - # We add two entries per config line: we need to accept the new - # connection, and latter the reply. - local stNew=NEW,ESTABLISHED,RELATED - local stEst=ESTABLISHED,RELATED - - # In-Out means full-duplex - [[ "$dir" =~ ^inout ]] && stEst="$stNew" - - local iptNew= iptEst= optsNew= optsEst= - case "$dport" in - *,*|*:*) optsNew="--match multiport --dports $dport" - optsEst="--match multiport --sports $dport";; - ?*) optsNew="--dport $dport" - optsEst="--sport $dport";; - esac - case "$sport" in - *,*|*:*) optsNew+=" --match multiport --sports $sport" - optsEst+=" --match multiport --dports $sport";; - ?*) optsNew+=" --sport $sport" - optsEst+=" --dport $sport";; - esac - case "$dir" in - in|inout) iptNew="-A INPUT -i"; iptEst="-A OUTPUT -o";; - out) iptNew="-A OUTPUT -o"; iptEst="-A INPUT -i";; - *) fatal "Error: Unknown direction: '$dir'." - esac - - iptables $iptNew $if -p $proto $optsNew -m state --state $stNew -j ACCEPT - iptables $iptEst $if -p $proto $optsEst -m state --state $stEst -j ACCEPT - done - - iptables -A OUTPUT -o $if -p tcp -j REJECT --reject-with tcp-reset - iptables -A OUTPUT -o $if -p udp -j REJECT --reject-with port-unreach - if [ "$f" = "4" ]; then - iptables -A OUTPUT -o $if -p icmp -j REJECT --reject-with icmp-host-unreachable - iptables -A OUTPUT -o $if -j REJECT --reject-with icmp-host-prohibited - else - iptables -A OUTPUT -o $if -j REJECT - fi - - ######################################################################## - commit - - - local rv1=0 rv2=0 persistent=/etc/iptables/rules.v$f - local oldz=$(mktemp --tmpdir current-rules.v$f.XXXXXX) - - # Reset the counters. They are not useful for comparing and/or - # storing persistent ruleset. (We don't use sed -i because we want - # to restore the counters when reverting.) - sed -r -e '/^:/ s/\[[0-9]+:[0-9]+\]$/[0:0]/' \ - -e 's/^\[[0-9]+:[0-9]+\]\s+//' \ - "$old" >"$oldz" - - ip netns exec $netns $ipt-restore <"$new" || ipt-revert - - for table in ${tables[$f]}; do - ip netns exec $netns $ipt-save -t $table - done >"$new" - - ipt-diff --label="a/$ipt-save" --label="b/$ipt-save" "$oldz" "$new" || rv1=$? - - if ! [ -f "$persistent" ] && [ -x /etc/network/if-pre-up.d/iptables ]; then - rv2=1 - else - ipt-trim <"$new" | ipt-diff --label="a/rules.v$f" --label="b/$ipt-save" "$persistent" - || rv2=$? - fi - - local update="Please run '${0##*/}'." - if [ $check -eq 0 ]; then - uniq "$new" | $ipt-restore || ipt-revert - else - if [ $rv1 -ne 0 ]; then - log "WARN: The IPv$f firewall is not up to date! $update" - fi - if [ $rv2 -ne 0 ]; then - log "WARN: The current IPv$f firewall is not persistent! $update" - fi - fi - - rm -f "$oldz" "$new" - return $(( $rv1 | $rv2 )) -} - - -# Parse options -while [ $# -gt 0 ]; do - case "$1" in - -?*) for (( k=1; k<${#1}; k++ )); do - o="${1:$k:1}" - case "$o" in - 4|6) addrfam="$o";; - c) check=1;; - f) force=1;; - v) verbose=1;; - *) usage;; - esac - done - ;; - *) usage;; - esac - shift -done - -# If we are going to apply the ruleset, we should either have a TTY, or -# use -f. -if ! tty -s && [ $force -eq 0 ] && [ $check -eq 0 ]; then - echo "Error: Not a TTY. Try with -f (at your own risks!)" >&2 - exit 1 -fi - -# 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-$$" -ip netns add $netns - -trap 'ip netns del $netns 2>/dev/null || true; ipt-revert' SIGINT -trap 'ip netns del $netns; rm -f "${rss[@]}"' EXIT - -rv=0 -for f in ${addrfam:=4 6}; do - run $f || rv=$(( $rv | $? )) -done - -if [ $force -eq 1 ]; then - # At the user's own risks... - ipt-persist - -elif [ $check -eq 1 ] || [ $rv -eq 0 ]; then - # Nothing to do, we're all set. - exit $rv - -else - echo "Try now to establish NEW connections to the machine." - - read -n1 -t$timeout \ - -p "Are you sure you want to use the new ruleset? (y/N) " \ - ret 2>&1 || { [ $? -gt 128 ] && echo -n "Timeout..."; } - case "${ret:-N}" in - [yY]*) echo; ipt-persist - ;; - *) echo; ipt-revert - ;; - esac -fi |