devlink: introduce dump filtering function

This function is to be used from dump callbacks to decide if the output
currect output should be filtered off or not. Filtering is based on
previously parsed and stored command line options.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>

devlink/devlink.c

@@ -563,6 +563,36 @@ static int dl_argv_parse_put(struct nlmsghdr *nlh, struct dl *dl,
 	return 0;
 }
 
+static bool dl_dump_filter(struct dl *dl, struct nlattr **tb)
+{
+	struct dl_opts *opts = &dl->opts;
+	struct nlattr *attr_bus_name = tb[DEVLINK_ATTR_BUS_NAME];
+	struct nlattr *attr_dev_name = tb[DEVLINK_ATTR_DEV_NAME];
+	struct nlattr *attr_port_index = tb[DEVLINK_ATTR_PORT_INDEX];
+
+	if (opts->present & DL_OPT_HANDLE &&
+	    attr_bus_name && attr_dev_name) {
+		const char *bus_name = mnl_attr_get_str(attr_bus_name);
+		const char *dev_name = mnl_attr_get_str(attr_dev_name);
+
+		if (strcmp(bus_name, opts->bus_name) != 0 ||
+		    strcmp(dev_name, opts->dev_name) != 0)
+			return false;
+	}
+	if (opts->present & DL_OPT_HANDLEP &&
+	    attr_bus_name && attr_dev_name && attr_port_index) {
+		const char *bus_name = mnl_attr_get_str(attr_bus_name);
+		const char *dev_name = mnl_attr_get_str(attr_dev_name);
+		uint32_t port_index = mnl_attr_get_u32(attr_port_index);
+
+		if (strcmp(bus_name, opts->bus_name) != 0 ||
+		    strcmp(dev_name, opts->dev_name) != 0 ||
+		    port_index != opts->port_index)
+			return false;
+	}
+	return true;
+}
+
 static void cmd_dev_help(void)
 {
 	pr_out("Usage: devlink dev show [ DEV ]\n");