freebsd-nq/lib/libc/gen/getbsize.c
Colin Percival cb8330d036 Set "max" to a reasonable value if BLOCKSIZE has a bogus unit. Prior
to this commit, "env BLOCKSIZE=4X df" prints not only "4X: unknown
blocksize" as expected, but sometimes also "maximum blocksize is 1G"
and "minimum blocksize is 512" depending on what happened to be on
the stack.

Found by:	LLVM/Clang Static Checker
2008-08-04 06:53:13 +00:00

107 lines
3.1 KiB
C

/*-
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* 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.
* 4. 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 defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)getbsize.c 8.1 (Berkeley) 6/4/93";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
char *
getbsize(headerlenp, blocksizep)
int *headerlenp;
long *blocksizep;
{
static char header[20];
long n, max, mul, blocksize;
char *ep, *p;
const char *form;
#define KB (1024L)
#define MB (1024L * 1024L)
#define GB (1024L * 1024L * 1024L)
#define MAXB GB /* No tera, peta, nor exa. */
form = "";
if ((p = getenv("BLOCKSIZE")) != NULL && *p != '\0') {
if ((n = strtol(p, &ep, 10)) < 0)
goto underflow;
if (n == 0)
n = 1;
if (*ep && ep[1])
goto fmterr;
switch (*ep) {
case 'G': case 'g':
form = "G";
max = MAXB / GB;
mul = GB;
break;
case 'K': case 'k':
form = "K";
max = MAXB / KB;
mul = KB;
break;
case 'M': case 'm':
form = "M";
max = MAXB / MB;
mul = MB;
break;
case '\0':
max = MAXB;
mul = 1;
break;
default:
fmterr: warnx("%s: unknown blocksize", p);
n = 512;
max = MAXB;
mul = 1;
break;
}
if (n > max) {
warnx("maximum blocksize is %ldG", MAXB / GB);
n = max;
}
if ((blocksize = n * mul) < 512) {
underflow: warnx("minimum blocksize is 512");
form = "";
blocksize = n = 512;
}
} else
blocksize = n = 512;
(void)snprintf(header, sizeof(header), "%ld%s-blocks", n, form);
*headerlenp = strlen(header);
*blocksizep = blocksize;
return (header);
}