hostapd: run as user 'network' if procd-ujail is installed

Granting capabilities CAP_NET_ADMIN and CAP_NET_RAW allows running
hostapd and wpa_supplicant without root priviledges.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

package/network/services/hostapd/Makefile

@@ -7,7 +7,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=hostapd
-PKG_RELEASE:=25
+PKG_RELEASE:=26
 
 PKG_SOURCE_URL:=http://w1.fi/hostap.git
 PKG_SOURCE_PROTO:=git
@@ -145,6 +145,7 @@ define Package/hostapd/Default
   TITLE:=IEEE 802.1x Authenticator
   URL:=http://hostap.epitest.fi/
   DEPENDS:=$(DRV_DEPENDS) +hostapd-common +libubus
+  USERID:=network=101:network=101
   PROVIDES:=hostapd
   CONFLICTS:=$(HOSTAPD_PROVIDERS)
   HOSTAPD_PROVIDERS+=$(1)
@@ -228,6 +229,7 @@ define Package/wpad/Default
   SUBMENU:=WirelessAPD
   TITLE:=IEEE 802.1x Auth/Supplicant
   DEPENDS:=$(DRV_DEPENDS) +hostapd-common +libubus
+  USERID:=network=101:network=101
   URL:=http://hostap.epitest.fi/
   PROVIDES:=hostapd wpa-supplicant
   CONFLICTS:=$(HOSTAPD_PROVIDERS) $(SUPPLICANT_PROVIDERS)
@@ -342,6 +344,7 @@ define Package/wpa-supplicant/Default
   TITLE:=WPA Supplicant
   URL:=http://hostap.epitest.fi/wpa_supplicant/
   DEPENDS:=$(DRV_DEPENDS) +hostapd-common +libubus
+  USERID:=network=101:network=101
   PROVIDES:=wpa-supplicant
   CONFLICTS:=$(SUPPLICANT_PROVIDERS)
   SUPPLICANT_PROVIDERS+=$(1)
@@ -593,10 +596,12 @@ define Install/supplicant
 endef
 
 define Package/hostapd-common/install
-	$(INSTALL_DIR) $(1)/lib/netifd $(1)/etc/rc.button $(1)/etc/hotplug.d/ieee80211 $(1)/etc/init.d
+	$(INSTALL_DIR) $(1)/etc/capabilities $(1)/etc/rc.button $(1)/etc/hotplug.d/ieee80211 $(1)/etc/init.d $(1)/lib/netifd  $(1)/usr/share/acl.d
 	$(INSTALL_DATA) ./files/hostapd.sh $(1)/lib/netifd/hostapd.sh
 	$(INSTALL_BIN) ./files/wpad.init $(1)/etc/init.d/wpad
 	$(INSTALL_BIN) ./files/wps-hotplug.sh $(1)/etc/rc.button/wps
+	$(INSTALL_DATA) ./files/wpad_acl.json $(1)/usr/share/acl.d
+	$(INSTALL_DATA) ./files/wpad.json $(1)/etc/capabilities
 endef
 
 define Package/hostapd/install

package/network/services/hostapd/files/wpad.init

@@ -9,17 +9,33 @@ NAME=wpad
 start_service() {
 	if [ -x "/usr/sbin/hostapd" ]; then
 		mkdir -p /var/run/hostapd
+		chown network:network /var/run/hostapd
 		procd_open_instance hostapd
 		procd_set_param command /usr/sbin/hostapd -s -g /var/run/hostapd/global
 		procd_set_param respawn 3600 1 0
+		[ -x /sbin/ujail -a -e /etc/capabilities/wpad.json ] && {
+			procd_add_jail hostapd
+			procd_set_param capabilities /etc/capabilities/wpad.json
+			procd_set_param user network
+			procd_set_param group network
+			procd_set_param no_new_privs 1
+		}
 		procd_close_instance
 	fi
 
 	if [ -x "/usr/sbin/wpa_supplicant" ]; then
 		mkdir -p /var/run/wpa_supplicant
+		chown network:network /var/run/wpa_supplicant
 		procd_open_instance supplicant
 		procd_set_param command /usr/sbin/wpa_supplicant -n -s -g /var/run/wpa_supplicant/global
 		procd_set_param respawn 3600 1 0
+		[ -x /sbin/ujail -a -e /etc/capabilities/wpad.json ] && {
+			procd_add_jail wpa_supplicant
+			procd_set_param capabilities /etc/capabilities/wpad.json
+			procd_set_param user network
+			procd_set_param group network
+			procd_set_param no_new_privs 1
+		}
 		procd_close_instance
 	fi
 }

package/network/services/hostapd/files/wpad.json

@@ -0,0 +1,22 @@
+{
+	"bounding": [
+		"CAP_NET_ADMIN",
+		"CAP_NET_RAW"
+	],
+	"effective": [
+		"CAP_NET_ADMIN",
+		"CAP_NET_RAW"
+	],
+	"ambient": [
+		"CAP_NET_ADMIN",
+		"CAP_NET_RAW"
+	],
+	"permitted": [
+		"CAP_NET_ADMIN",
+		"CAP_NET_RAW"
+	],
+	"inheritable": [
+		"CAP_NET_ADMIN",
+		"CAP_NET_RAW"
+	]
+}

package/network/services/hostapd/files/wpad_acl.json

@@ -0,0 +1,10 @@
+{
+	"user": "network",
+	"access": {
+		"service": {
+			"methods": [ "event" ]
+		}
+	},
+	"publish": [ "hostapd", "hostapd.*", "wpa_supplicant", "wpa_supplicant.*" ],
+	"send": [ "bss.*", "wps_credentials" ]
+}