diff options
Diffstat (limited to 'roles/common/files/usr/local')
| -rwxr-xr-x | roles/common/files/usr/local/sbin/update-firewall.sh | 102 |
1 files changed, 32 insertions, 70 deletions
diff --git a/roles/common/files/usr/local/sbin/update-firewall.sh b/roles/common/files/usr/local/sbin/update-firewall.sh index f25f507..065bae2 100755 --- a/roles/common/files/usr/local/sbin/update-firewall.sh +++ b/roles/common/files/usr/local/sbin/update-firewall.sh @@ -23,42 +23,46 @@ # 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= -secmark=0xA99 # must match that in /etc/network/if-up.d/ipsec -secproto=esp # must match /etc/ipsec.conf; ESP is the default (vs AH/IPComp) +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 fail2ban-\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() { @@ -135,155 +139,153 @@ ipt-persist() { ipt-revert() { [ $check -eq 0 ] || return log "Reverting to old ruleset... " local rs for f in "${!rss[@]}"; do /sbin/$(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="$1" local ipt=/sbin/$(inet46 $f iptables ip6tables) tables[$f]=filter # The default interface associated with this address. - local if=$( /bin/ip -$f route show to default scope global \ + local if=$( /bin/ip -$f -o route show to default scope global \ | sed -nr '/^default via \S+ dev (\S+).*/ {s//\1/p;q}' ) - # The virtual interface reserved for IPSec. - local ifsec=$( /bin/ip -o -$f link show \ - | sed -nr "/^[0-9]+:\s+(sec[0-9]+)@$if:\s.*/ {s//\1/p;q}" ) - - # The (host-scoped) IP reserved for IPSec. - local ipsec= - if [ "$ifsec" -a $f = 4 ]; then - tables[$f]='mangle nat filter' - ipsec=$( /bin/ip -$f address show dev "$ifsec" scope host \ - | sed -nr '/^\s+inet\s(\S+).*/ {s//\1/p;q}' ) - fi - # Store the old (current) ruleset local old=$(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 [ "$f" = 4 ] && which /usr/bin/fail2ban-server >/dev/null; then fail2ban=1 fi # The usual chains in filter, along with the desired default policies. ipt-chains filter INPUT:DROP FORWARD:DROP OUTPUT:DROP if [ ! "$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. mv "$new" /etc/iptables/rules.v$f return 0 fi # Fail2ban-specific chains and traps if [ $fail2ban -eq 1 ]; then echo ":fail2ban - [0:0]" # Don't remove existing rules & traps in the current rulest grep -- '^:fail2ban-\S' "$old" || true grep -E -- ' -j fail2ban-\S+$' "$old" || true grep -E -- "$fail2ban_re" "$old" || true fi >> "$new" - if [ "$ipsec" ]; then - # (Host-to-host) IPSec tunnels come first. TODO: test IPSec with IPv6. + if [ "$f" = 4 -a "$ipsec" = y ]; then + # Our IPSec tunnels are IPv4 only. + # (Host-to-host) IPSec tunnels come first. 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 ]; then + if [ "$f" = 4 -a "$ipsec" = y ]; then # Private-use networks (RFC 1918) and link local (RFC 3927) - local MyNetwork=$( /bin/ip -4 address show dev $if scope global \ - | sed -nr 's/^\s+inet\s(\S+).*/\1/p') + local MyIPSec="$( /bin/ip -4 -o route show table 220 dev $if | sed 's/\s.*//' )" + local MyNetwork="$( /bin/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" = "$(/usr/bin/netmask -nc "$ip" "$ips" | sed 's/^ *//')" ] || echo "$ip" + done + done + )" [ "$MyNetwork" ] && \ for ip in 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16 169.254.0.0/16; do # Don't lock us out if we are behind a NAT ;-) - [ "$ip" = "$(/usr/bin/netmask -nc $ip $MyNetwork | sed 's/ //g')" ] \ - || iptables -A INPUT -i $if -s "$ip" -j DROP + for myip in $MyNetwork; do + [ "$ip" = "$(/usr/bin/netmask -nc "$ip" "$myip" | sed 's/^ *//')" ] \ + || 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 DROP # 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 "$localhost" -j ACCEPT - - if [ "$ipsec" ]; then - # ACCEPT any, *IPSec* traffic destinating to the non-routable - # $ipsec. Also ACCEPT all traffic originating from $ipsec, as - # it is MASQUERADE'd. - iptables -A INPUT -d "$ipsec" -i $if -m policy --dir in \ - --pol ipsec --proto $secproto -j ACCEPT - iptables -A OUTPUT -m mark --mark "$secmark" -o $if -j ACCEPT + if [ "$f" = 4 -a "$ipsec" = y ]; then + # Allow local access to our virtual IP + /bin/ip -4 -o route show table 220 dev $if \ + | sed -nr 's/.*\ssrc\s+([[:digit:].]{7,15})(\s.*)?/\1/p' \ + | while read ipsec; do + iptables -A INPUT -i lo -s "$ipsec" -d "$ipsec" -j ACCEPT + iptables -A OUTPUT -o lo -s "$ipsec" -d "$ipsec" -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 [ $f = 6 ]; then iptables -A INPUT -p icmpv6 -j ACCEPT iptables -A OUTPUT -p icmpv6 -j ACCEPT fi @@ -313,80 +315,40 @@ run() { esac case "$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 $stEst -j ACCEPT done ######################################################################## commit - if [ "$ipsec" ]; then - # DNAT the IPSec paquets to $ipsec after decapsulation, and SNAT - # them before encapsulation. We need to do the NAT'ing before - # packets enter the IPSec stack because they are signed - # afterwards, and NAT'ing would mess up the signature. - ipt-chains mangle PREROUTING:ACCEPT INPUT:ACCEPT \ - FORWARD:DROP \ - OUTPUT:ACCEPT POSTROUTING:ACCEPT - - # Packets which destination is $ipsec *must* be associated with - # an IPSec policy. - iptables -A INPUT -d "$ipsec" -i $if -m policy --dir in \ - --pol ipsec --proto $secproto -j ACCEPT - iptables -A INPUT -d "$ipsec" -i $if -j DROP - - # Packets originating from our (non-routable) $ipsec are marked; - # if there is no xfrm lookup (i.e., no matching IPSec - # association), the packet will retain its mark and be null - # routed later on. Otherwise, the packet is re-queued unmarked. - iptables -A OUTPUT -o $if -j MARK --set-mark 0x0 - iptables -A OUTPUT -s "$ipsec" -o $if -m policy --dir out \ - --pol none -j MARK --set-mark $secmark - commit - - ipt-chains nat PREROUTING:ACCEPT INPUT:ACCEPT \ - OUTPUT:ACCEPT POSTROUTING:ACCEPT - - # DNAT all marked packets after decapsulation. - iptables -A PREROUTING \! -d "$ipsec" -i $if -m policy --dir in \ - --pol ipsec --proto $secproto -j DNAT --to "${ipsec%/*}" - - # Packets originating from our IPSec are SNAT'ed (MASQUERADE). - # (And null-routed later on unless there is an xfrm - # association.) - iptables -A POSTROUTING -m mark --mark $secmark -o $if -j MASQUERADE - commit - fi - - ######################################################################## - local rv1=0 rv2=0 persistent=/etc/iptables/rules.v$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" /usr/bin/uniq "$new" | /bin/ip netns exec $netns $ipt-restore || ipt-revert for table in ${tables[$f]}; do /bin/ip netns exec $netns $ipt-save -t $table done > "$new" ipt-diff "$oldz" "$new" || rv1=$? if ! [ -f "$persistent" -a -x /etc/network/if-pre-up.d/iptables ]; then |