diff options
Diffstat (limited to 'lib/libutil/expand_number.c')
| -rw-r--r-- | lib/libutil/expand_number.c | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/lib/libutil/expand_number.c b/lib/libutil/expand_number.c new file mode 100644 index 000000000000..a3313ba39d98 --- /dev/null +++ b/lib/libutil/expand_number.c @@ -0,0 +1,187 @@ +/*- + * SPDX-License-Identifier: BSD-2-Clause + * + * Copyright (c) 2007 Eric Anderson <anderson@FreeBSD.org> + * Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org> + * Copyright (c) 2025 Dag-Erling Smørgrav <des@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/types.h> + +#include <ctype.h> +#include <errno.h> +#include <inttypes.h> +#include <libutil.h> +#include <stdbool.h> +#include <stdint.h> + +static int +expand_impl(const char *buf, uint64_t *num, bool *neg) +{ + char *endptr; + uintmax_t number; + unsigned int shift; + int serrno; + + /* + * Skip whitespace and optional sign. + */ + while (isspace((unsigned char)*buf)) + buf++; + if (*buf == '-') { + *neg = true; + buf++; + } else { + *neg = false; + if (*buf == '+') + buf++; + } + + /* + * The next character should be the first digit of the number. If + * we don't enforce this ourselves, strtoumax() will allow further + * whitespace and a (second?) sign. + */ + if (!isdigit((unsigned char)*buf)) { + errno = EINVAL; + return (-1); + } + + serrno = errno; + errno = 0; + number = strtoumax(buf, &endptr, 0); + if (errno != 0) + return (-1); + errno = serrno; + + switch (tolower((unsigned char)*endptr)) { + case 'e': + shift = 60; + endptr++; + break; + case 'p': + shift = 50; + endptr++; + break; + case 't': + shift = 40; + endptr++; + break; + case 'g': + shift = 30; + endptr++; + break; + case 'm': + shift = 20; + endptr++; + break; + case 'k': + shift = 10; + endptr++; + break; + default: + shift = 0; + } + + /* + * Treat 'b' as an ignored suffix for all unit except 'b', + * otherwise there should be no remaining character(s). + */ + if (tolower((unsigned char)*endptr) == 'b') + endptr++; + if (*endptr != '\0') { + errno = EINVAL; + return (-1); + } + + /* + * Apply the shift and check for overflow. + */ + if ((number << shift) >> shift != number) { + /* Overflow */ + errno = ERANGE; + return (-1); + } + number <<= shift; + + *num = number; + return (0); +} + +int +(expand_number)(const char *buf, int64_t *num) +{ + uint64_t number; + bool neg; + + /* + * Parse the number. + */ + if (expand_impl(buf, &number, &neg) != 0) + return (-1); + + /* + * Apply the sign and check for overflow. + */ + if (neg) { + if (number > 0x8000000000000000LLU /* -INT64_MIN */) { + errno = ERANGE; + return (-1); + } + *num = -number; + } else { + if (number > INT64_MAX) { + errno = ERANGE; + return (-1); + } + *num = number; + } + + return (0); +} + +int +expand_unsigned(const char *buf, uint64_t *num) +{ + uint64_t number; + bool neg; + + /* + * Parse the number. + */ + if (expand_impl(buf, &number, &neg) != 0) + return (-1); + + /* + * Negative numbers are out of range. + */ + if (neg && number > 0) { + errno = ERANGE; + return (-1); + } + + *num = number; + return (0); +} |