add a ubus handler that allows sending signals to processes

Signed-off-by: John Crispin <blogic@openwrt.org>

system.c

@@ -18,7 +18,7 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
-
+#include <signal.h>
 #include <unistd.h>
 
 #include <libubox/uloop.h>
@@ -257,11 +257,41 @@ static int watchdog_set(struct ubus_context *ctx, struct ubus_object *obj,
 	return 0;
 }
 
+enum {
+	SIGNAL_PID,
+	SIGNAL_NUM,
+	__SIGNAL_MAX
+};
+
+static const struct blobmsg_policy signal_policy[__WDT_MAX] = {
+	[SIGNAL_PID] = { .name = "pid", .type = BLOBMSG_TYPE_INT32 },
+	[SIGNAL_NUM] = { .name = "signum", .type = BLOBMSG_TYPE_INT32 },
+};
+
+static int proc_signal(struct ubus_context *ctx, struct ubus_object *obj,
+			struct ubus_request_data *req, const char *method,
+			struct blob_attr *msg)
+{
+	struct blob_attr *tb[__SIGNAL_MAX];
+
+	if (!msg)
+		return UBUS_STATUS_INVALID_ARGUMENT;
+
+	blobmsg_parse(signal_policy, __SIGNAL_MAX, tb, blob_data(msg), blob_len(msg));
+	if (!tb[SIGNAL_PID || !tb[SIGNAL_NUM]])
+		return UBUS_STATUS_INVALID_ARGUMENT;
+
+	kill(blobmsg_get_u32(tb[SIGNAL_PID]), blobmsg_get_u32(tb[SIGNAL_NUM]));
+
+	return 0;
+}
+
 static const struct ubus_method system_methods[] = {
 	UBUS_METHOD_NOARG("board", system_board),
 	UBUS_METHOD_NOARG("info",  system_info),
 	UBUS_METHOD_NOARG("upgrade", system_upgrade),
 	UBUS_METHOD("watchdog", watchdog_set, watchdog_policy),
+	UBUS_METHOD("signal", proc_signal, signal_policy),
 };
 
 static struct ubus_object_type system_object_type =