/*
 * rstsmack - Restore smack attributes on files
 *
 * Copyright (c) 2000 - 2017 Samsung Electronics Co., Ltd.
 *
 * Contact: MyoungJune Park <mj2004.park@samsung.com>
 *   Created by Wonil Choi <wonil22.choi@samsung.com>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <linux/limits.h>
#include <sys/smack.h>

#ifdef DEBUG
#  define LOGINFO(fmt, arg...)	printf(fmt, ##arg)
#else
#  define LOGINFO(fmt, arg...)
#endif

void print_help(const char *cmd)
{
	printf("Usage: %s <INPUT FILE>\n", cmd);
	printf("       INPUT FILE should be same format as generated by"
			" chsmack.\n\n");
	printf("       Ex) # chsmack /usr/bin/* > /tmp/rstsmack_input.txt\n");
}

static inline int abandonqm(char *label)
{
	int ret = 0;
	/* ignore last character which must be a quotation mark */
	ret = (int) strlen(label);
	ret--;
	if (ret > SMACK_LABEL_LEN || ret <= 0)
		return -1;
	label[ret] = '\0';
	return 0;
}

static void set_label(const char *pathname, char *label, int type)
{
	int ret = -1;

	if (abandonqm(label) == 0) {
		ret = smack_lsetlabel(pathname, label, type);
		if (ret < 0)
			perror(pathname);
	} else
		fprintf(stderr, "The input file has wrong format, %s\n",
				pathname);
}

static int parse_and_set(const char *srcfile)
{
	/* We assume the text format of input file is same as chsmack output */
	FILE *fp;
	int ret = 0;
	char linebuf[PATH_MAX + 5 * SMACK_LABEL_LEN], pathname[PATH_MAX];
	char label[SMACK_LABEL_LEN + 1];
	char *plabel; /* pointer of beginning smack label */
	fp = fopen(srcfile, "r");
	if (fp == NULL)
		return -1;

	while (fgets(linebuf, sizeof(linebuf), fp)) {
		plabel = strstr(linebuf, " access=");
		if (plabel && linebuf != plabel) {
			*plabel = '\0';
			strncpy(pathname, linebuf, sizeof(pathname));
			pathname[sizeof(pathname) - 1] = '\0';
			plabel++;
		} else {
			linebuf[strlen(linebuf) - 1] = '\0';
			LOGINFO("no label, set label: %s, access=\"_\"(floor)\n", linebuf);
			strncpy(label, "_\"", SMACK_LABEL_LEN);
			set_label(linebuf, label, SMACK_LABEL_ACCESS);
			/* TODO: If file name contains " access=" then it would
			 * not be processed */
			continue;
		}

		LOGINFO("set label: %s,", pathname);

		ret = sscanf(plabel, "access=\"%s", label);
		if (ret > 0) {
			LOGINFO(" access: \"%s", label);
			set_label(pathname, label,  SMACK_LABEL_ACCESS);
			plabel = plabel + sizeof(" access=\"") + strlen(label);
		}

		ret = sscanf(plabel, "execute=\"%s", label);
		if (ret > 0) {
			LOGINFO(", exec: \"%s", label);
			set_label(pathname, label, SMACK_LABEL_EXEC);
			plabel = plabel + sizeof(" execute=\"") + strlen(label);
		}

		ret = sscanf(plabel, "mmap=\"%s", label);
		if (ret > 0) {
			LOGINFO(", mmap: \"%s", label);
			set_label(pathname, label, SMACK_LABEL_MMAP);
			plabel = plabel + sizeof(" mmap=\"") + strlen(label);
		}

		ret = sscanf(plabel, "transmute=\"%s", label);
		if (ret > 0) {
			LOGINFO(", transmute: \"%s", label);
			strncpy(label, "1\"", SMACK_LABEL_LEN);
			set_label(pathname, label, SMACK_LABEL_TRANSMUTE);
		}
		LOGINFO("\n");

	}
	fclose(fp);
	return 0;
}

int main(int argc, char *argv[])
{
	if (argc < 2) {
		print_help(argv[0]);
		return -1;
	}
	if (parse_and_set(argv[1]) < 0) {
		print_help(argv[0]);
		return -1;
	}
	return 0;
}