freebsd-dev/usr.bin/fortune/unstr/unstr.c
Don Lewis 243e928310 Avoid buffer overflow when copying the input file name and appending .dat.
Check the return value from fread() to be sure that it was successful.

Reported by:	Coverity
CID:		1006709, 1009452
MFC after:	1 week
2016-05-26 01:33:24 +00:00

138 lines
4.3 KiB
C

/*-
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Ken Arnold.
*
* 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.
*/
#if 0
#ifndef lint
static const char copyright[] =
"@(#) Copyright (c) 1991, 1993\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
static const char sccsid[] = "@(#)unstr.c 8.1 (Berkeley) 5/31/93";
#endif /* not lint */
#endif
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* This program un-does what "strfile" makes, thereby obtaining the
* original file again. This can be invoked with the name of the output
* file, the input file, or both. If invoked with only a single argument
* ending in ".dat", it is pressumed to be the input file and the output
* file will be the same stripped of the ".dat". If the single argument
* doesn't end in ".dat", then it is presumed to be the output file, and
* the input file is that name prepended by a ".dat". If both are given
* they are treated literally as the input and output files.
*
* Ken Arnold Aug 13, 1978
*/
#include <sys/param.h>
#include <sys/endian.h>
#include <ctype.h>
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "strfile.h"
static char *Infile, /* name of input file */
Datafile[MAXPATHLEN], /* name of data file */
Delimch; /* delimiter character */
static FILE *Inf, *Dataf;
static void order_unstr(STRFILE *);
/* ARGSUSED */
int
main(int argc, char *argv[])
{
static STRFILE tbl; /* description table */
if (argc != 2) {
fprintf(stderr, "usage: unstr datafile\n");
exit(1);
}
Infile = argv[1];
if ((size_t)snprintf(Datafile, sizeof(Datafile), "%s.dat", Infile) >=
sizeof(Datafile))
errx(1, "%s name too long", Infile);
if ((Inf = fopen(Infile, "r")) == NULL)
err(1, "%s", Infile);
if ((Dataf = fopen(Datafile, "r")) == NULL)
err(1, "%s", Datafile);
if (fread((char *)&tbl, sizeof(tbl), 1, Dataf) != 1) {
if (feof(Dataf))
errx(1, "%s read EOF", Datafile);
else
err(1, "%s read", Datafile);
}
tbl.str_version = be32toh(tbl.str_version);
tbl.str_numstr = be32toh(tbl.str_numstr);
tbl.str_longlen = be32toh(tbl.str_longlen);
tbl.str_shortlen = be32toh(tbl.str_shortlen);
tbl.str_flags = be32toh(tbl.str_flags);
if (!(tbl.str_flags & (STR_ORDERED | STR_RANDOM)))
errx(1, "nothing to do -- table in file order");
Delimch = tbl.str_delim;
order_unstr(&tbl);
fclose(Inf);
fclose(Dataf);
exit(0);
}
static void
order_unstr(STRFILE *tbl)
{
uint32_t i;
char *sp;
off_t pos;
char buf[BUFSIZ];
for (i = 0; i < tbl->str_numstr; i++) {
fread(&pos, 1, sizeof(pos), Dataf);
fseeko(Inf, be64toh(pos), SEEK_SET);
if (i != 0)
printf("%c\n", Delimch);
for (;;) {
sp = fgets(buf, sizeof(buf), Inf);
if (sp == NULL || STR_ENDSTRING(sp, *tbl))
break;
else
fputs(sp, stdout);
}
}
}