1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2007 Eric Anderson <anderson@FreeBSD.org> 5 * Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org> 6 * Copyright (c) 2025 Dag-Erling Smørgrav <des@FreeBSD.org> 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 #include <sys/types.h> 32 33 #include <ctype.h> 34 #include <errno.h> 35 #include <inttypes.h> 36 #include <libutil.h> 37 #include <stdbool.h> 38 #include <stdint.h> 39 40 int 41 expand_number(const char *buf, int64_t *num) 42 { 43 char *endptr; 44 uintmax_t number; 45 unsigned int shift; 46 bool neg; 47 int serrno; 48 49 /* 50 * Skip whitespace and optional sign. 51 */ 52 while (isspace((unsigned char)*buf)) 53 buf++; 54 if (*buf == '-') { 55 neg = true; 56 buf++; 57 } else { 58 neg = false; 59 if (*buf == '+') 60 buf++; 61 } 62 63 /* 64 * The next character should be the first digit of the number. If 65 * we don't enforce this ourselves, strtoumax() will allow further 66 * whitespace and a (second?) sign. 67 */ 68 if (!isdigit((unsigned char)*buf)) { 69 errno = EINVAL; 70 return (-1); 71 } 72 73 serrno = errno; 74 errno = 0; 75 number = strtoumax(buf, &endptr, 0); 76 if (errno != 0) 77 return (-1); 78 errno = serrno; 79 80 switch (tolower((unsigned char)*endptr)) { 81 case 'e': 82 shift = 60; 83 endptr++; 84 break; 85 case 'p': 86 shift = 50; 87 endptr++; 88 break; 89 case 't': 90 shift = 40; 91 endptr++; 92 break; 93 case 'g': 94 shift = 30; 95 endptr++; 96 break; 97 case 'm': 98 shift = 20; 99 endptr++; 100 break; 101 case 'k': 102 shift = 10; 103 endptr++; 104 break; 105 default: 106 shift = 0; 107 } 108 109 /* 110 * Treat 'b' as an ignored suffix for all unit except 'b', 111 * otherwise there should be no remaining character(s). 112 */ 113 if (tolower((unsigned char)*endptr) == 'b') 114 endptr++; 115 if (*endptr != '\0') { 116 errno = EINVAL; 117 return (-1); 118 } 119 120 /* 121 * Apply the shift and check for overflow. 122 */ 123 if ((number << shift) >> shift != number) { 124 /* Overflow */ 125 errno = ERANGE; 126 return (-1); 127 } 128 number <<= shift; 129 130 /* 131 * Apply the sign and check for overflow. 132 */ 133 if (neg) { 134 if (number > 0x8000000000000000LLU /* -INT64_MIN */) { 135 errno = ERANGE; 136 return (-1); 137 } 138 *num = -number; 139 } else { 140 if (number > INT64_MAX) { 141 errno = ERANGE; 142 return (-1); 143 } 144 *num = number; 145 } 146 147 return (0); 148 } 149