1 /*- 2 * Copyright (c) 2001 Charles Mott <cm@linktel.net> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/param.h> 31 #include <sys/ctype.h> 32 #include <sys/limits.h> 33 #include <sys/systm.h> 34 35 #include <netinet/in.h> 36 37 int 38 inet_aton(const char *cp, struct in_addr *addr) 39 { 40 u_long parts[4]; 41 in_addr_t val; 42 const char *c; 43 char *endptr; 44 int gotend, n; 45 46 c = (const char *)cp; 47 n = 0; 48 49 /* 50 * Run through the string, grabbing numbers until 51 * the end of the string, or some error 52 */ 53 gotend = 0; 54 while (!gotend) { 55 unsigned long l; 56 57 l = strtoul(c, &endptr, 0); 58 59 if (l == ULONG_MAX || (l == 0 && endptr == c)) 60 return (0); 61 62 val = (in_addr_t)l; 63 64 /* 65 * If the whole string is invalid, endptr will equal 66 * c.. this way we can make sure someone hasn't 67 * gone '.12' or something which would get past 68 * the next check. 69 */ 70 if (endptr == c) 71 return (0); 72 parts[n] = val; 73 c = endptr; 74 75 /* Check the next character past the previous number's end */ 76 switch (*c) { 77 case '.' : 78 79 /* Make sure we only do 3 dots .. */ 80 if (n == 3) /* Whoops. Quit. */ 81 return (0); 82 n++; 83 c++; 84 break; 85 86 case '\0': 87 gotend = 1; 88 break; 89 90 default: 91 if (isspace((unsigned char)*c)) { 92 gotend = 1; 93 break; 94 } else { 95 96 /* Invalid character, then fail. */ 97 return (0); 98 } 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 } 136 137