gluon-mesh-vpn-core: add vpn protocol respondd provider

package/gluon-mesh-vpn-core/src/Makefile

+all: respondd.so
+
+CFLAGS += -Wall -Werror-implicit-function-declaration
+
+respondd.so: respondd.c
+	$(CC) $(CPPFLAGS) $(CFLAGS) $(LDFLAGS) -shared -fPIC -D_GNU_SOURCE -o $@ $^ $(LDLIBS) -lgluonutil

package/gluon-mesh-vpn-core/src/respondd.c

+/*
+  Copyright (c) 2021, Aiyion <gluon@aiyionpri.me>
+  Copyright (c) 2016, Matthias Schiffer <mschiffer@universe-factory.net>
+  All rights reserved.
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions are met:
+    1. Redistributions of source code must retain the above copyright notice,
+       this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright notice,
+       this list of conditions and the following disclaimer in the documentation
+       and/or other materials provided with the distribution.
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#include <respondd.h>
+
+#include <stdio.h>
+#include <string.h>
+
+#include <json-c/json.h>
+#include <libgluonutil.h>
+
+
+char * read_stdout(const char *command) {
+	FILE *f = popen(command, "r");
+	if (!f)
+		return NULL;
+
+	char *line = NULL;
+	size_t len = 0;
+
+	ssize_t r = getline(&line, &len, f);
+
+	pclose(f);
+
+	if (r < 0) {
+		free(line);
+		return NULL;
+	}
+
+	/* The len given by getline is the buffer size, not the string length */
+	len = strlen(line);
+
+	if (len && line[len-1] == '\n')
+		line[len-1] = 0;
+
+	return line;
+}
+
+static struct json_object * get_mesh_vpn_enabled() {
+	int enabled = -1;
+	char *line = read_stdout("exec lua -e 'print(require(\"gluon.mesh-vpn\").enabled())'");
+
+	if (!strcmp(line, "true"))
+		enabled = 1;
+	if (!strcmp(line, "false"))
+		enabled = 0;
+	free(line);
+
+	if (enabled < 0)
+		return NULL;
+
+	struct json_object *ret = json_object_new_boolean((json_bool)enabled);
+	return ret;
+}
+
+static struct json_object * get_active_vpn_provider() {
+	char *line = read_stdout("exec lua -e 'name, _ = require(\"gluon.mesh-vpn\").get_active_provider(); print(name)'");
+
+	if (!strcmp(line, "nil")) {
+		free(line);
+		return NULL;
+	}
+
+	return gluonutil_wrap_and_free_string(line);
+}
+
+static struct json_object * respondd_provider_nodeinfo(void) {
+	struct json_object *ret = json_object_new_object();
+	struct json_object *network = json_object_new_object();
+	struct json_object *mesh_vpn = json_object_new_object();
+
+	json_object_object_add(mesh_vpn, "provider", get_active_vpn_provider());
+	json_object_object_add(mesh_vpn, "enabled", get_mesh_vpn_enabled());
+	json_object_object_add(network, "mesh_vpn", mesh_vpn);
+	json_object_object_add(ret, "network", network);
+
+	return ret;
+}
+
+const struct respondd_provider_info respondd_providers[] = {
+	{"nodeinfo", respondd_provider_nodeinfo},
+	{},
+	{}
+};