freebsd-dev/lib/libutil/expand_number.c
Xin LI 08300d8494 expand_number: Tighten check of unit.
The current code silently ignores characters after the unit as long
the unit themselves were recognized. This commit makes expand_number(3)
to fail with EINVAL if buf did not terminate after the unit character.

Historically, the function accepts and ignores "B" as a SI unit, this
behavior is preserved and e.g. KB, MB are still accepted as aliases of
K and M, document this behavior in the manual page.

While I am there, also write a few test cases to validate the behavior.

Reviewed-by:	emaste
MFC-after:	2 weeks
Differential Revision: https://reviews.freebsd.org/D40482
2023-06-12 21:08:32 -07:00

110 lines
2.7 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2007 Eric Anderson <anderson@FreeBSD.org>
* Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHORS 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 AUTHORS 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <ctype.h>
#include <errno.h>
#include <inttypes.h>
#include <libutil.h>
#include <stdint.h>
int
expand_number(const char *buf, uint64_t *num)
{
char *endptr;
uintmax_t umaxval;
uint64_t number;
unsigned shift;
int serrno;
serrno = errno;
errno = 0;
umaxval = strtoumax(buf, &endptr, 0);
if (umaxval > UINT64_MAX)
errno = ERANGE;
if (errno != 0)
return (-1);
errno = serrno;
number = umaxval;
switch (tolower((unsigned char)*endptr)) {
case 'e':
shift = 60;
break;
case 'p':
shift = 50;
break;
case 't':
shift = 40;
break;
case 'g':
shift = 30;
break;
case 'm':
shift = 20;
break;
case 'k':
shift = 10;
break;
case 'b':
shift = 0;
break;
case '\0': /* No unit. */
*num = number;
return (0);
default:
/* Unrecognized unit. */
errno = EINVAL;
return (-1);
}
/*
* Treat 'b' as an ignored suffix for all unit except 'b',
* otherwise there should be no remaining character(s).
*/
endptr++;
if (shift != 0 && tolower((unsigned char)*endptr) == 'b')
endptr++;
if (*endptr != '\0') {
errno = EINVAL;
return (-1);
}
if ((number << shift) >> shift != number) {
/* Overflow */
errno = ERANGE;
return (-1);
}
*num = number << shift;
return (0);
}