net-firewall/nftables: Add atomic nftables updates for modern kernels

Signed-off-by: Francisco Blas Izquierdo Riera <klondike@gentoo.org>
Package-Manager: Portage-2.3.51, Repoman-2.3.11
Signed-off-by: Matthew Thode <prometheanfire@gentoo.org>

3 files changed, 189 insertions, 0 deletions

diff --git a/net-firewall/nftables/files/libexec/nftables-mk.sh b/net-firewall/nftables/files/libexec/nftables-mk.sh
new file mode 100644
index 000000000000..b6ad37867b6d
--- /dev/null
+++ b/net-firewall/nftables/files/libexec/nftables-mk.sh
@@ -0,0 +1,59 @@
+#!/bin/sh
+
+main() {
+	local NFTABLES_SAVE=${2:-'/var/lib/nftables/rules-save'}
+	case "$1" in
+		"check")
+			nft -c -f "${NFTABLES_SAVE}"
+		;;
+		"clear")
+			nft flush ruleset
+		;;
+		"list")
+			nft ${SAVE_OPTIONS} list ruleset
+		;;
+		"load")
+			( echo "flush ruleset;"; cat "${NFTABLES_SAVE}" ) | nft -f -
+		;;
+		"panic")
+			panic hard | nft -f -
+		;;
+		"soft_panic")
+			panic soft | nft -f -
+		;;
+		"store")
+			local tmp_save="${NFTABLES_SAVE}.tmp"
+			umask 600;
+			(
+				echo "#!/sbin/nft -f"
+				echo "flush ruleset;"
+				nft ${SAVE_OPTIONS} list ruleset
+			) > "$tmp_save" && mv ${tmp_save} ${NFTABLES_SAVE}
+		;;
+	esac
+}
+
+panic() {
+	local erule;
+	[ "$1" = soft ] && erule="ct state established,related accept;" || erule="";
+	cat <<EOF
+table inet filter {
+	chain input {
+		type filter hook input priority 0;
+		$erule
+		drop
+	}
+	chain forward {
+		type filter hook forward priority 0;
+		drop
+	}
+	chain output {
+		type filter hook output priority 0;
+		$erule
+		drop
+	}
+}
+EOF
+}
+
+main "$@"
diff --git a/net-firewall/nftables/files/nftables-mk.confd b/net-firewall/nftables/files/nftables-mk.confd
new file mode 100644
index 000000000000..5cda24030f93
--- /dev/null
+++ b/net-firewall/nftables/files/nftables-mk.confd
@@ -0,0 +1,26 @@
+# /etc/conf.d/nftables
+
+# Location in which nftables initscript will save set rules on
+# service shutdown
+NFTABLES_SAVE="/var/lib/nftables/rules-save"
+
+# Options to pass to nft on save
+SAVE_OPTIONS="-n"
+
+# Save state on stopping nftables
+SAVE_ON_STOP="yes"
+
+# Only for OpenRC systems.
+# Set to "hard" or "soft" to panic when stopping instead of
+# clearing the rules
+# Soft panic loads a ruleset dropping any new or invalid connections
+# Hard panic loads a ruleset dropping all traffic
+PANIC_ON_STOP=""
+
+# If you need to log nftables messages as soon as nftables starts,
+# AND your logger does NOT depend on the network, then you may wish
+# to uncomment the next line.
+# If your logger depends on the network, and you uncomment this line
+# you will create an unresolvable circular dependency during startup.
+# After commenting or uncommenting this line, you must run 'rc-update -u'.
+#rc_use="logger"
diff --git a/net-firewall/nftables/files/nftables-mk.init b/net-firewall/nftables/files/nftables-mk.init
new file mode 100644
index 000000000000..f7e3dce8ada2
--- /dev/null
+++ b/net-firewall/nftables/files/nftables-mk.init
@@ -0,0 +1,104 @@
+#!/sbin/openrc-run
+# Copyright 1999-2019 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+extra_commands="check clear list panic save soft_panic"
+extra_started_commands="reload"
+
+depend() {
+	need localmount #434774
+	before net
+}
+
+checkkernel() {
+	if ! /sbin/nft list ruleset >/dev/null 2>/dev/null ; then
+		eerror "Your kernel lacks nftables support, please load"
+		eerror "appropriate modules and try again."
+		return 1
+	fi
+	return 0
+}
+
+checkconfig() {
+	if [ -z "${NFTABLES_SAVE}" -o ! -f "${NFTABLES_SAVE}" ] ; then
+		eerror "Not starting nftables. First create some rules then run:"
+		eerror "/etc/init.d/${SVCNAME} save"
+		return 1
+	fi
+	return 0
+}
+
+start_pre() {
+	checkconfig || return 1
+	checkkernel || return 1
+	check || return 1
+}
+
+start() {
+	ebegin "Loading ${SVCNAME} state and starting firewall"
+	/usr/libexec/nftables/nftables.sh load "${NFTABLES_SAVE}"
+	eend $?
+}
+
+stop() {
+	if [ "${SAVE_ON_STOP}" = "yes" ] ; then
+		save || return 1
+	fi
+
+	ebegin "Stopping firewall"
+	if [ "${PANIC_ON_STOP}" = "hard" ]; then
+		/usr/libexec/nftables/nftables.sh panic
+	elif [ "${PANIC_ON_STOP}" = "soft" ]; then
+		/usr/libexec/nftables/nftables.sh soft_panic
+	else
+		/usr/libexec/nftables/nftables.sh clear
+	fi
+	eend $?
+}
+
+reload() {
+	start_pre || return 1
+	start
+}
+
+clear() {
+	ebegin "Clearing rules"
+	/usr/libexec/nftables/nftables.sh clear
+	eend $?
+}
+
+list() {
+	/usr/libexec/nftables/nftables.sh list
+}
+
+check() {
+	ebegin "Checking rules"
+	/usr/libexec/nftables/nftables.sh check "${NFTABLES_SAVE}"
+	eend $?
+}
+
+save() {
+	ebegin "Saving ${SVCNAME} state"
+	checkpath -q -d "$(dirname "${NFTABLES_SAVE}")"
+	checkpath -q -m 0600 -f "${NFTABLES_SAVE}"
+	/usr/libexec/nftables/nftables.sh store "${NFTABLES_SAVE}"
+	eend $?
+}
+
+panic() {
+	if service_started ${SVCNAME}; then
+		rc-service ${SVCNAME} zap
+	fi
+	ebegin "Dropping all packets"
+	/usr/libexec/nftables/nftables.sh panic
+	eend $?
+}
+
+soft_panic() {
+	if service_started ${SVCNAME}; then
+		rc-service ${SVCNAME} zap
+	fi
+	ebegin "Dropping new connections"
+	/usr/libexec/nftables/nftables.sh soft_panic
+	eend $?
+}