diff options
Diffstat (limited to 'contrib/blocklist/libexec/blocklistd-helper')
| -rwxr-xr-x | contrib/blocklist/libexec/blocklistd-helper | 272 |
1 files changed, 272 insertions, 0 deletions
diff --git a/contrib/blocklist/libexec/blocklistd-helper b/contrib/blocklist/libexec/blocklistd-helper new file mode 100755 index 000000000000..f27cde4ed4ea --- /dev/null +++ b/contrib/blocklist/libexec/blocklistd-helper @@ -0,0 +1,272 @@ +#!/bin/sh +#echo "run $@" 1>&2 +#set -x +# $1 command +# $2 rulename +# $3 protocol +# $4 address +# $5 mask +# $6 port +# $7 id + +pf= +if [ -f "/etc/ipfw-blocklist.rc" ]; then + pf="ipfw" + . /etc/ipfw-blocklist.rc + ipfw_offset=${ipfw_offset:-2000} +fi + +if [ -z "$pf" ]; then + for f in npf pf ipfilter ipfw; do + if [ -x /etc/rc.d/$f ]; then + if /etc/rc.d/$f status >/dev/null 2>&1; then + pf="$f" + break + fi + elif [ -f "/etc/$f.conf" ]; then + # xxx assume a config file means it can be enabled -- + # and the first one wins! + pf="$f" + break + fi + done +fi + +if [ -z "$pf" -a -x "/sbin/iptables" ]; then + pf="iptables" +fi + +if [ -z "$pf" ]; then + echo "$0: Unsupported packet filter" 1>&2 + exit 1 +fi + +flags= +if [ -n "$3" ]; then + raw_proto="$3" + proto="proto $3" + if [ $3 = "tcp" ]; then + flags="flags S/SAFR" + fi +fi + +if [ -n "$6" ]; then + raw_port="$6" + port="port $6" +fi + +addr="$4" +mask="$5" +case "$4" in +::ffff:*.*.*.*) + if [ "$5" = 128 ]; then + mask=32 + addr=${4#::ffff:} + fi;; +esac + +case "$1" in +add) + case "$pf" in + ipfilter) + # N.B.: If you reload /etc/ipf.conf then you need to stop and + # restart blocklistd (and make sure blocklistd_flags="-r"). + # This should normally already be implemented in + # /etc/rc.d/ipfilter, but if then not add the following lines to + # the end of the ipfilter_reload() function: + # + # if checkyesnox blocklistd; then + # /etc/rc.d/blocklistd restart + # fi + # + # XXX we assume the following rule is present in /etc/ipf.conf: + # (should we check? -- it probably cannot be added dynamically) + # + # block in proto tcp/udp from any to any head blocklistd + # + # where "blocklistd" is the default rulename (i.e. "$2") + # + # This rule can come before any rule that logs connections, + # etc., and should be followed by final rules such as: + # + # # log all as-yet unblocked incoming TCP connection + # # attempts + # log in proto tcp from any to any flags S/SAFR + # # last "pass" match wins for all non-blocked packets + # pass in all + # pass out all + # + # I.e. a "pass" rule which will be the final match and override + # the "block". This way the rules added by blocklistd will + # actually block packets, and prevent logging of them as + # connections, because they include the "quick" flag. + # + # N.b.: $port is not included/used in rules -- abusers are cut + # off completely from all services! + # + # Note RST packets are not returned for blocked SYN packets of + # active attacks, so the port will not appear to be closed. + # This will probably give away the fact that a firewall has been + # triggered to block connections, but it prevents generating + # extra outbound traffic, and it may also slow down the attacker + # somewhat. + # + # Note also that we don't block all packets, just new attempts + # to open connections (see $flags above). This allows us to do + # counterespionage against the attacker (or continue to make use + # of any other services that might be on the same subnet as the + # supposed attacker). However it does not kill any active + # connections -- we rely on the reporting daemon to do its own + # protection and cleanup. + # + # N.B.: The rule generated here must exactly match the + # corresponding rule generated for the "rem" command below! + # + echo block in log quick $proto \ + from $addr/$mask to any $flags group $2 | \ + /sbin/ipf -A -f - >/dev/null 2>&1 && echo OK + ;; + + ipfw) + # use $ipfw_offset+$port for rule number + rule=$(($ipfw_offset + $6)) + tname="port$6" + /sbin/ipfw table $tname create type addr 2>/dev/null + /sbin/ipfw -q table $tname add "$addr/$mask" + # if rule number $rule does not already exist, create it + /sbin/ipfw show $rule >/dev/null 2>&1 || \ + /sbin/ipfw add $rule drop $3 from \ + table"("$tname")" to any dst-port $6 >/dev/null && \ + echo OK + ;; + + iptables) + if ! /sbin/iptables --list "$2" >/dev/null 2>&1; then + /sbin/iptables --new-chain "$2" + fi + /sbin/iptables --append INPUT --proto "$raw_proto" \ + --dport "$raw_port" --jump "$2" + /sbin/iptables --append "$2" --proto "$raw_proto" \ + --source "$addr/$mask" --dport "$raw_port" --jump DROP + echo OK + ;; + + npf) + /sbin/npfctl rule "$2" add block in final $proto from \ + "$addr/$mask" to any $port + ;; + + pf) + # if the filtering rule does not exist, create it + /sbin/pfctl -a "$2/$6" -sr 2>/dev/null | \ + grep -q "<port$6>" || \ + echo "block in quick $proto from <port$6> to any $port" | \ + /sbin/pfctl -a "$2/$6" -f - + # insert $ip/$mask into per-protocol/port anchored table + /sbin/pfctl -qa "$2/$6" -t "port$6" -T add "$addr/$mask" && \ + /sbin/pfctl -qk "$addr" && echo OK + ;; + + esac + ;; +rem) + case "$pf" in + ipfilter) + # N.B.: The rule generated here must exactly match the + # corresponding rule generated for the "add" command above! + # + echo block in log quick $proto \ + from $addr/$mask to any $flags group $2 | \ + /sbin/ipf -A -r -f - >/dev/null 2>&1 && echo OK + ;; + + ipfw) + /sbin/ipfw table "port$6" delete "$addr/$mask" 2>/dev/null && \ + echo OK + ;; + + iptables) + if /sbin/iptables --list "$2" >/dev/null 2>&1; then + /sbin/iptables --delete "$2" --proto "$raw_proto" \ + --source "$addr/$mask" --dport "$raw_port" \ + --jump DROP + fi + echo OK + ;; + + npf) + /sbin/npfctl rule "$2" rem-id "$7" + ;; + + pf) + /sbin/pfctl -qa "$2/$6" -t "port$6" -T delete "$addr/$mask" && \ + echo OK + ;; + + esac + ;; +flush) + case "$pf" in + ipfilter) + # + # N.B. WARNING: This is obviously not reentrant! + # + # First we flush all the rules from the inactive set, then we + # reload the ones that do not belong to the group "$2", and + # finally we swap the active and inactive rule sets. + # + /sbin/ipf -I -F a + # + # "ipf -I -F a" also flushes active accounting rules! + # + # Note that accounting rule groups are unique to accounting + # rules and have nothing to do with filter rules, though of + # course theoretically one could use the same group name for + # them too. + # + # In theory anyone using any such accounting rules should have a + # wrapper /etc/rc.conf.d/blocklistd script (and corresponding + # /etc/rc.conf.d/ipfilter script) that will record and + # consolidate the values accumulated by such accounting rules + # before they are flushed, since otherwise their counts will be + # lost forever. + # + /usr/sbin/ipfstat -io | fgrep -v "group $2" | \ + /sbin/ipf -I -f - >/dev/null 2>&1 + # + # This MUST be done last and separately as "-s" is executed + # _while_ the command arguments are being processed! + # + /sbin/ipf -s && echo OK + ;; + + ipfw) + /sbin/ipfw table "port$6" flush 2>/dev/null && echo OK + ;; + + iptables) + if /sbin/iptables --list "$2" >/dev/null 2>&1; then + /sbin/iptables --flush "$2" + fi + echo OK + ;; + + npf) + /sbin/npfctl rule "$2" flush + ;; + + pf) + # dynamically determine which anchors exist + for anchor in $(/sbin/pfctl -a "$2" -s Anchors 2> /dev/null); do + /sbin/pfctl -a "$anchor" -t "port${anchor##*/}" -T flush + /sbin/pfctl -a "$anchor" -F rules + done + echo OK + ;; + esac + ;; +*) + echo "$0: Unknown command '$1'" 1>&2 + exit 1 + ;; +esac |