ini.c

#include <ctype.h>
/*
 * Simple ini file parser
 *
 *  This should be copied from somewhere but, unfortunately is reinvented.
 *
 * Copyright (C) 2019 James.Bottomley@HansenPartnership.com
 *
 * SPDX-License-Identifier: LGPL-2.1-only
 */

#include <fcntl.h>
#include <limits.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <unistd.h>

#include <sys/types.h>
#include <sys/stat.h>

#include "openssl-pkcs11.h"

#define BUF_SIZE 4096

static char *conf_buf = NULL;
static ssize_t conf_size;
static char *read_pos;

static char *trim(char *line)
{
	int len;

	while (isspace(*line))
		line++;

	len = strlen(line);
	if (len == 0)
		return line;

	for (--len; isspace(line[len]); --len)
		;
	line[len + 1] = '\0';

	return line;
}

static char *read_line(void)
{
	char *eol;
	char *ret;

	eol  = strchr(read_pos, '\n');
	ret = read_pos;

	if (!eol)
		return NULL;

	*eol = '\0';
	read_pos = eol + 1;

	return ret;
}

static void parse_mem(void)
{
	char *line, *delim;
	char *section = GLOBAL_SECTION, *key, *value;

	read_pos = conf_buf;
	while ((line = read_line()) != NULL) {
		int end;

		line = trim(line);
		end = strlen(line) - 1;
		if (line[0] == '#' || line[0] == '\0')
			continue;
		if (line[0] == '[' && line[end] == ']') {
			line[end] = '\0';
			section = ++line;
			continue;
		}
		delim = strchr(line, '=');
		if (!delim) {
			fprintf(stderr, "illegal line in config file '%s'\n",
				line);
			continue;
		}
		*delim = '\0';
		key = trim(line);
		value = trim(delim + 1);

		cache_add(section, key, value, 0);
	}
}

int parse_ini_file(void)
{
	char *home = getenv("HOME");
	char *conf = getenv(ENV_CONFIG);
	char *end;
	char config[PATH_MAX];
	int fd,len;
	struct stat st;

	config[0] = '\0';
	if (conf) {
		strncpy(config, conf, sizeof(config) - 1);
	} else {
		strncpy(config, home, sizeof(config) - 1);
		strcat(config, "/");
		strcat(config, CONFIG_FILE);
	}

	fd = open(config, O_RDONLY);

	if (fd < 0) {
		fprintf(stderr, "failed to open config file %s: %s\n",
			config, strerror(errno));
		return 0;
	}
	if (fstat(fd, &st)) {
		fprintf(stderr, "failed to stat config file %s: %s\n",
			config, strerror(errno));
		return 0;
	}
	conf_size = st.st_size;
	if (conf_size == 0) {
		fprintf(stderr, "conf file %s is empty\n", config);
		return 0;
	}

	conf_buf = malloc(conf_size + 2);
	if (!conf_buf) {
		fprintf(stderr, "failed to allocate %d bytes for con file %s\n",
			(int)conf_size, config);
		return 0;
	}

	len = read(fd, conf_buf, conf_size);
	if (len < 0) {
		fprintf(stderr, "failed to read config file %s: %s\n",
			config, strerror(errno));
		return 0;
	}
	if (len != conf_size) {
		fprintf(stderr, "Config file %s changed while being read\n",
			config);
		free(conf_buf);
		return 0;
	}
	close(fd);

	/* the parser requires the file end with a newline,
	 * so add one if needed */
	end = &conf_buf[conf_size - 1];
	if (*end++ != '\n')
		*end++ = '\n';
	*end = '\0';
	parse_mem();
	cache_load_crypto_keys();
	return 1;
}

void free_ini_file(void)
{
	free(conf_buf);
}