xref: /openbsd/usr.sbin/amd/amd/info_file.c (revision 9cd31872)

/*
 * Copyright (c) 1990 Jan-Simon Pendry
 * Copyright (c) 1990 Imperial College of Science, Technology & Medicine
 * Copyright (c) 1990, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Jan-Simon Pendry at Imperial College, London.
 *
 * 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.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
 *
 *	from: @(#)info_file.c	8.1 (Berkeley) 6/6/93
 *	$Id: info_file.c,v 1.9 2014/10/26 03:03:34 guenther Exp $
 */

/*
 * Get info from file
 */

#include "am.h"

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

#define	MAX_LINE_LEN	2048

static int
read_line(char *buf, int size, FILE *fp)
{
	int done = 0;

	do {
		while (fgets(buf, size, fp)) {
			int len = strlen(buf);

			done += len;
			if (len > 1 && buf[len-2] == '\\' &&
			    buf[len-1] == '\n') {
				int ch;

				buf += len - 2;
				size -= len - 2;
				*buf = '\n'; buf[1] = '\0';
				/*
				 * Skip leading white space on next line
				 */
				while ((ch = getc(fp)) != EOF &&
				    isascii(ch) && isspace(ch))
					;
				(void) ungetc(ch, fp);
			} else {
				return done;
			}
		}
	} while (size > 0 && !feof(fp));
	return done;
}

/*
 * Try to locate a key in a file
 */
static int
search_or_reload_file(FILE *fp, char *map, char *key, char **val, mnt_map *m,
    void (*fn)(mnt_map *m, char *, char *))
{
	char key_val[MAX_LINE_LEN];
	int chuck = 0;
	int line_no = 0;

	while (read_line(key_val, sizeof(key_val), fp)) {
		char *kp;
		char *cp;
		char *hash;
		int len = strlen(key_val);

		line_no++;

		/*
		 * Make sure we got the whole line
		 */
		if (key_val[len-1] != '\n') {
			plog(XLOG_WARNING, "line %d in \"%s\" is too long",
			    line_no, map);
			chuck = 1;
		} else {
			key_val[len-1] = '\0';
		}

		/*
		 * Strip comments
		 */
		hash = strchr(key_val, '#');
		if (hash)
			*hash = '\0';

		/*
		 * Find start of key
		 */
		for (kp = key_val;
		    isascii((unsigned char)*kp) && isspace((unsigned char)*kp);
		    kp++)
			;

		/*
		 * Ignore blank lines
		 */
		if (!*kp)
			goto again;

		/*
		 * Find end of key
		 */
		for (cp = kp; *cp &&
		    (!isascii((unsigned char)*cp) || !isspace((unsigned char)*cp));
		    cp++)
			;

		/*
		 * Check whether key matches
		 */
		if (*cp)
			*cp++ = '\0';

		if (fn || (*key == *kp && strcmp(key, kp) == 0)) {
			while (isascii((unsigned char)*cp) &&
			    isspace((unsigned char)*cp))
				cp++;
			if (*cp) {
				/*
				 * Return a copy of the data
				 */
				char *dc = strdup(cp);
				if (fn) {
					(*fn)(m, strdup(kp), dc);
				} else {
					*val = dc;
#ifdef DEBUG
					dlog("%s returns %s", key, dc);
#endif /* DEBUG */
				}
				if (!fn)
					return 0;
			} else {
				plog(XLOG_USER, "%s: line %d has no value field",
				    map, line_no);
			}
		}

again:
		/*
		 * If the last read didn't get a whole line then
		 * throw away the remainder before continuing...
		 */
		if (chuck) {
			while (fgets(key_val, sizeof(key_val), fp) &&
			    !strchr(key_val, '\n'))
					;
			chuck = 0;
		}
	}

	return fn ? 0 : ENOENT;
}

static FILE *
file_open(char *map, time_t *tp)
{
	FILE *mapf = fopen(map, "r");

	if (mapf && tp) {
		struct stat stb;

		if (fstat(fileno(mapf), &stb) < 0)
			*tp = clocktime();
		else
			*tp = stb.st_mtime;
	}
	return mapf;
}

int
file_init(char *map, time_t *tp)
{
	FILE *mapf = file_open(map, tp);

	if (mapf) {
		(void) fclose(mapf);
		return 0;
	}
	return errno;
}

int
file_reload(mnt_map *m, char *map, void (*fn)(mnt_map *, char *, char *))
{
	FILE *mapf = file_open(map, (time_t *) 0);

	if (mapf) {
		int error = search_or_reload_file(mapf, map, 0, 0, m, fn);
		(void) fclose(mapf);
		return error;
	}

	return errno;
}

int
file_search(mnt_map *m, char *map, char *key, char **pval, time_t *tp)
{
	time_t t;
	FILE *mapf = file_open(map, &t);

	if (mapf) {
		int error;
		if (*tp < t) {
			*tp = t;
			error = -1;
		} else {
			error = search_or_reload_file(mapf, map, key, pval, 0, 0);
		}
		(void) fclose(mapf);
		return error;
	}

	return errno;
}

int
file_mtime(char *map, time_t *tp)
{
	FILE *mapf = file_open(map, tp);

	if (mapf) {
		(void) fclose(mapf);
		return 0;
	}

	return errno;
}