From 26febd7376e8c1679d5d088d71d73bc64585ec1e Mon Sep 17 00:00:00 2001
From: Justin Wind <justin.wind+git@gmail.com>
Date: Tue, 24 Jan 2017 15:20:47 -0800
Subject: [PATCH] fancier services

---
 common.sh   | 33 +++++++++++++++++++++++++++++++++
 firewall.sh | 19 ++++++++++---------
 2 files changed, 43 insertions(+), 9 deletions(-)

diff --git a/common.sh b/common.sh
index 781df4a..f8860fc 100644
--- a/common.sh
+++ b/common.sh
@@ -21,11 +21,21 @@ function create_set(){
 }
 
 function insert_setmatch_rules(){
+	local single=0
+	if [ "x$1" = "x-single-set" ]
+	then
+		single=1
+		shift
+	fi
 	local ipt set_name="$1"
 	shift
 	for v in '' '6'
 	do
 		eval ipt="\$IP${v}TABLES"
+		if [ $single -eq 1 ]
+		then
+			v=''
+		fi
 		if ! $ipt -C INPUT -m set --match-set "${set_name}${v}" src "$@" >/dev/null 2>&1
 		then
 			echo "initializing rule '${set_name}${v}'"
@@ -74,3 +84,26 @@ function reload_cidr_sets(){
 	done
 }
 
+function add_service_entry(){
+	local port/proto
+	port=$(echo "${s}" | cut -d/ -f1)
+	proto=$(echo "${s}" | cut -d/ -f2)
+	$IPSET -exist add allowed_${proto} ${port}
+}
+
+function allow_services(){
+	local s proto port
+	for s in "$@"
+	do
+		case "${s}" in
+		*/*)	add_service_entry "${s}"
+			;;
+		*)	for svc in $(getent services "${s}" | awk '{print $2}')
+			do
+				add_service_entry "${svc}"
+			done
+			;;
+		esac
+	done
+}
+
diff --git a/firewall.sh b/firewall.sh
index 4106807..eab2cb3 100755
--- a/firewall.sh
+++ b/firewall.sh
@@ -52,7 +52,7 @@ $IPTABLES -A INPUT -p icmp -j ACCEPT
 $IP6TABLES -A INPUT -p ipv6-icmp -j ACCEPT
 
 # drop source-route rh0 headery things
-$IP6TABLES -A INPUT -m rt --rt-type 0 -j DROP
+$IP6TABLES -A INPUT -m rt --rt-type 0 -j DROP || echo "MISSING RT MATCH" 1>&2
 
 # accept things we set up
 $IPTABLES -A INPUT -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
@@ -74,14 +74,15 @@ done
 create_set allowed_udp bitmap:port range 0-65535
 create_set allowed_tcp bitmap:port range 0-65535
 
-for p in 22 25 53 80 143 443 587 993 1194 5000 5222 5269 22556 64738
-do
-	$IPSET -exist add allowed_tcp ${p}
-done
-for p in 53 123 1194 64738
-do
-	$IPSET -exist add allowed_udp ${p}
-done
+# common services
+allow_services ssh smtp submission domain ntp
+
+# per-host services
+srv_file="services.$(hostname -s)"
+if [ -e "${srv_file}" ]
+then
+	. "${srv_file}"
+fi
 
 $IPTABLES -A INPUT -i "${EXT_IF}" -p tcp -m set --match-set allowed_tcp dst -j ACCEPT
 $IPTABLES -A INPUT -i "${EXT_IF}" -p udp -m set --match-set allowed_udp dst -j ACCEPT
-- 
2.45.2