1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2001 Charles Mott <cm@linktel.net> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/param.h> 33 #include <sys/ctype.h> 34 #include <sys/limits.h> 35 #include <sys/systm.h> 36 37 #include <netinet/in.h> 38 39 int 40 inet_aton(const char *cp, struct in_addr *addr) 41 { 42 u_long parts[4]; 43 in_addr_t val; 44 const char *c; 45 char *endptr; 46 int gotend, n; 47 48 c = (const char *)cp; 49 n = 0; 50 51 /* 52 * Run through the string, grabbing numbers until 53 * the end of the string, or some error 54 */ 55 gotend = 0; 56 while (!gotend) { 57 unsigned long l; 58 59 l = strtoul(c, &endptr, 0); 60 61 if (l == ULONG_MAX || (l == 0 && endptr == c)) 62 return (0); 63 64 val = (in_addr_t)l; 65 66 /* 67 * If the whole string is invalid, endptr will equal 68 * c.. this way we can make sure someone hasn't 69 * gone '.12' or something which would get past 70 * the next check. 71 */ 72 if (endptr == c) 73 return (0); 74 parts[n] = val; 75 c = endptr; 76 77 /* Check the next character past the previous number's end */ 78 switch (*c) { 79 case '.' : 80 81 /* Make sure we only do 3 dots .. */ 82 if (n == 3) /* Whoops. Quit. */ 83 return (0); 84 n++; 85 c++; 86 break; 87 88 case '\0': 89 gotend = 1; 90 break; 91 92 default: 93 if (isspace((unsigned char)*c)) { 94 gotend = 1; 95 break; 96 } else { 97 /* Invalid character, then fail. */ 98 return (0); 99 } 100 } 101 } 102 103 /* Concoct the address according to the number of parts specified. */ 104 switch (n) { 105 case 0: /* a -- 32 bits */ 106 107 /* 108 * Nothing is necessary here. Overflow checking was 109 * already done in strtoul(). 110 */ 111 break; 112 case 1: /* a.b -- 8.24 bits */ 113 if (val > 0xffffff || parts[0] > 0xff) 114 return (0); 115 val |= parts[0] << 24; 116 break; 117 118 case 2: /* a.b.c -- 8.8.16 bits */ 119 if (val > 0xffff || parts[0] > 0xff || parts[1] > 0xff) 120 return (0); 121 val |= (parts[0] << 24) | (parts[1] << 16); 122 break; 123 124 case 3: /* a.b.c.d -- 8.8.8.8 bits */ 125 if (val > 0xff || parts[0] > 0xff || parts[1] > 0xff || 126 parts[2] > 0xff) 127 return (0); 128 val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8); 129 break; 130 } 131 132 if (addr != NULL) 133 addr->s_addr = htonl(val); 134 return (1); 135 } 136