Create a simple config loader

include/cfg.h

@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2020 Andri Yngvason
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#pragma once
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#define X_CFG_LIST \
+	X(bool, enable_auth) \
+	X(string, private_key_file) \
+	X(string, certificate_file) \
+	X(string, username) \
+	X(string, password) \
+	X(string, address) \
+	X(uint, port) \
+
+struct cfg {
+#define string char*
+#define uint uint32_t
+#define X(type, name) type name;
+	X_CFG_LIST
+#undef X
+#undef uint
+#undef string
+};
+
+int cfg_load(struct cfg* self, const char* path);
+void cfg_destroy(struct cfg* self);

src/cfg.c

@@ -0,0 +1,154 @@
+/*
+ * Copyright (c) 2020 Andri Yngvason
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+
+#include "cfg.h"
+
+#define XSTR(s) STR(s)
+#define STR(s) #s
+
+static char* cfg__get_default_path(void)
+{
+	static char result[256];
+
+	char* xdg_config_home = getenv("XDG_CONFIG_HOME");
+	if (xdg_config_home) {
+		snprintf(result, sizeof(result), "%s/wayvnc/config",
+		         xdg_config_home);
+		result[sizeof(result) - 1] = '\0';
+		return result;
+	}
+
+	char* home = getenv("HOME");
+	if (!home)
+		return NULL;
+
+	snprintf(result, sizeof(result), "%s/.config/wayvnc/config", home);
+	result[sizeof(result) - 1] = '\0';
+	return result;
+}
+
+static char* cfg__trim_left(char* str)
+{
+	while (isspace(*str))
+		++str;
+	return str;
+}
+
+static char* cfg__trim_right(char* str)
+{
+	char* end = str + strlen(str) - 1;
+	while (str < end && isspace(*end))
+		*end-- = '\0';
+	return str;
+}
+
+static inline char* cfg__trim(char* str)
+{
+	return cfg__trim_right(cfg__trim_left(str));
+}
+
+static int cfg__load_key_value(struct cfg* self,
+                               const char* key, const char* value)
+{
+#define LOAD_bool(v) (strcmp(v, "false") != 0)
+#define LOAD_string(v) strdup(v)
+#define LOAD_uint(v) strtoul(v, NULL, 0)
+
+#define X(type, name) \
+	if (strcmp(XSTR(name), key) == 0) { \
+		self->name = LOAD_ ## type(value); \
+		return 0; \
+	}
+
+	X_CFG_LIST
+#undef X
+
+#undef LOAD_uint
+#undef LOAD_string
+#undef LOAD_bool
+	return -1;
+}
+
+static int cfg__load_line(struct cfg* self, char* line)
+{
+	line = cfg__trim(line);
+
+	if (line[0] == '\0' || line[0] == '#')
+		return 0;
+
+	char* delim = strchr(line, '=');
+	if (!delim)
+		return -1;
+
+	*delim = '\0';
+
+	char* key = cfg__trim_right(line);
+	char* value = cfg__trim_left(delim + 1);
+
+	return cfg__load_key_value(self, key, value);
+}
+
+int cfg_load(struct cfg* self, const char* requested_path)
+{
+	const char* path = requested_path ? requested_path
+	                                  : cfg__get_default_path();
+
+	if (!path)
+		return -1;
+
+	FILE* stream = fopen(path, "r");
+	if (!stream)
+		return -1;
+
+	char* line = NULL;
+	size_t len = 0;
+	int lineno = 0;
+
+	while (getline(&line, &len, stream) > 0) {
+		++lineno;
+
+		if (cfg__load_line(self, line) < 0)
+			goto failure;
+	}
+
+	fclose(stream);
+	return 0;
+
+failure:
+	cfg_destroy(self);
+	fclose(stream);
+	return lineno;
+}
+
+void cfg_destroy(struct cfg* self)
+{
+#define DESTROY_bool(...)
+#define DESTROY_uint(...)
+#define DESTROY_string(p) free(p)
+
+#define X(type, name) DESTROY_ ## type(self->name);
+	X_CFG_LIST
+#undef X
+
+#undef DESTROY_string
+#undef DESTROY_uint
+#undef DESTROY_bool
+}