drivers/main.{c,h}, drivers/dstate.c: introduce main_instcmd_fallback…

…() so drivers might implement their own "shutdown.default" at will [networkupstools#2670]

Signed-off-by: Jim Klimov <[email protected]>

drivers/dstate.c

@@ -847,15 +847,26 @@ static int sock_arg(conn_t *conn, size_t numarg, char **arg)
 		if (upsh.instcmd) {
 			ret = upsh.instcmd(cmdname, cmdparam);
 
-			/* send back execution result if requested */
-			if (cmdid)
-				send_tracking(conn, cmdid, ret);
+			if (ret != STAT_INSTCMD_UNKNOWN) {
+				/* send back execution result if requested */
+				if (cmdid)
+					send_tracking(conn, cmdid, ret);
 
-			/* The command was handled, status is a separate consideration */
-			return 1;
-		}
+				/* The command was handled, status is a separate consideration */
+				return 1;
+			} /* else try other handler(s) */
+		} /* else try other handler(s) */
+
+		/* Finally try the fallback handler shared by all drivers */
+		ret = main_instcmd_fallback(cmdname, cmdparam, conn);
+		/* send back execution result if requested */
+		if (cmdid)
+			send_tracking(conn, cmdid, ret);
 
-		upslogx(LOG_NOTICE, "Got INSTCMD, but driver lacks a handler");
+		if (ret == STAT_INSTCMD_UNKNOWN)
+			upslogx(LOG_NOTICE,
+				"Got INSTCMD '%s', but driver lacks a handler",
+				NUT_STRARG(cmdname));
 		return 1;
 	}
 

drivers/main.c

@@ -909,8 +909,9 @@ int upsdrv_shutdown_sdcommands_or_default(const char *sdcmds_default, char **cmd
 	return sdret;
 }
 
-/* handle instant commands common for all drivers */
-int main_instcmd(const char *cmdname, const char *extra, conn_t *conn) {
+/* handle instant commands common for all drivers - fallback for common
+ * command names that could be implemented in a driver but were not */
+int main_instcmd_fallback(const char *cmdname, const char *extra, conn_t *conn) {
 	char buf[SMALLBUF];
 	if (conn)
 #ifndef WIN32
@@ -942,6 +943,29 @@ int main_instcmd(const char *cmdname, const char *extra, conn_t *conn) {
 		return STAT_INSTCMD_HANDLED;
 	}
 
+	/* By default, the driver-specific values are
+	 * unknown to shared standard handler */
+	upsdebugx(2, "shared %s() does not handle command %s, "
+		"proceeding to driver-specific handler",
+		__func__, cmdname);
+	return STAT_INSTCMD_UNKNOWN;
+}
+
+/* handle instant commands common for all drivers */
+int main_instcmd(const char *cmdname, const char *extra, conn_t *conn) {
+	char buf[SMALLBUF];
+	if (conn)
+#ifndef WIN32
+		snprintf(buf, sizeof(buf), "socket %d", conn->fd);
+#else
+		snprintf(buf, sizeof(buf), "handle %p", conn->fd);
+#endif
+	else
+		snprintf(buf, sizeof(buf), "(null)");
+
+	upsdebugx(2, "entering main_instcmd(%s, %s) for [%s] on %s",
+		cmdname, extra, NUT_STRARG(upsname), buf);
+
 	if (!strcmp(cmdname, "driver.killpower")) {
 		/* An implementation of `drivername -k` requested from
 		 * the running and connected driver instance by protocol

drivers/main.h

@@ -62,6 +62,10 @@ int upsdrv_shutdown_sdcommands_or_default(const char *sdcmds_default, char **cmd
  */
 int main_instcmd(const char *cmdname, const char *extra, conn_t *conn);
 
+/* handle instant commands common for all drivers - fallback for common
+ * command names that could be implemented in a driver but were not */
+int main_instcmd_fallback(const char *cmdname, const char *extra, conn_t *conn);
+
 /* handle setting variables common for all drivers
  * (returns STAT_SET_* state values per enum in upshandler.h)
  */