1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 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/param.h> 30 #include <sys/ctype.h> 31 #include <sys/limits.h> 32 #include <sys/systm.h> 33 34 #include <netinet/in.h> 35 36 int 37 inet_aton(const char *cp, struct in_addr *addr) 38 { 39 u_long parts[4]; 40 in_addr_t val; 41 const char *c; 42 char *endptr; 43 int gotend, n; 44 45 c = (const char *)cp; 46 n = 0; 47 48 /* 49 * Run through the string, grabbing numbers until 50 * the end of the string, or some error 51 */ 52 gotend = 0; 53 while (!gotend) { 54 unsigned long l; 55 56 l = strtoul(c, &endptr, 0); 57 58 if (l == ULONG_MAX || (l == 0 && endptr == c)) 59 return (0); 60 61 val = (in_addr_t)l; 62 63 /* 64 * If the whole string is invalid, endptr will equal 65 * c.. this way we can make sure someone hasn't 66 * gone '.12' or something which would get past 67 * the next check. 68 */ 69 if (endptr == c) 70 return (0); 71 parts[n] = val; 72 c = endptr; 73 74 /* Check the next character past the previous number's end */ 75 switch (*c) { 76 case '.' : 77 78 /* Make sure we only do 3 dots .. */ 79 if (n == 3) /* Whoops. Quit. */ 80 return (0); 81 n++; 82 c++; 83 break; 84 85 case '\0': 86 gotend = 1; 87 break; 88 89 default: 90 if (isspace((unsigned char)*c)) { 91 gotend = 1; 92 break; 93 } else { 94 /* Invalid character, then fail. */ 95 return (0); 96 } 97 } 98 } 99 100 /* Concoct the address according to the number of parts specified. */ 101 switch (n) { 102 case 0: /* a -- 32 bits */ 103 104 /* 105 * Nothing is necessary here. Overflow checking was 106 * already done in strtoul(). 107 */ 108 break; 109 case 1: /* a.b -- 8.24 bits */ 110 if (val > 0xffffff || parts[0] > 0xff) 111 return (0); 112 val |= parts[0] << 24; 113 break; 114 115 case 2: /* a.b.c -- 8.8.16 bits */ 116 if (val > 0xffff || parts[0] > 0xff || parts[1] > 0xff) 117 return (0); 118 val |= (parts[0] << 24) | (parts[1] << 16); 119 break; 120 121 case 3: /* a.b.c.d -- 8.8.8.8 bits */ 122 if (val > 0xff || parts[0] > 0xff || parts[1] > 0xff || 123 parts[2] > 0xff) 124 return (0); 125 val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8); 126 break; 127 } 128 129 if (addr != NULL) 130 addr->s_addr = htonl(val); 131 return (1); 132 } 133