confd: bridge: Add STP/RSTP support

src/confd/bin/Makefile.am

@@ -1,3 +1,4 @@
 pkglibexec_SCRIPTS = bootstrap error load gen-service gen-hostname \
-		     gen-interfaces gen-motd gen-hardware gen-version
+		     gen-interfaces gen-motd gen-hardware gen-version \
+		     mstpd-wait-online
 sbin_SCRIPTS       = dagger migrate

src/confd/bin/mstpd-wait-online

@@ -0,0 +1,16 @@
+#!/bin/sh
+#
+# Block until mstpd has opened its control socket
+
+set -e
+
+timeout=${1:-10}
+
+for _ in $(seq $((timeout * 10))); do
+    ss -Haxn src '@.mstp_server*' | grep -q mstp_server && exit 0
+    sleep .1
+done
+
+logger -I $$ -p user.error -t mstpd-wait-online \
+       "Timeout waiting for mstpd to start"
+exit 1