inet_addr.c revision 1.3
1/* 2 * Copyright (c) 1983, 1990, 1993 3 * The Regents of the University of California. 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 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34#if defined(LIBC_SCCS) && !defined(lint) 35static char rcsid[] = "$OpenBSD: inet_addr.c,v 1.3 1996/08/19 08:29:08 tholo Exp $"; 36#endif /* LIBC_SCCS and not lint */ 37 38#include <sys/param.h> 39#include <netinet/in.h> 40#include <arpa/inet.h> 41#include <ctype.h> 42 43/* 44 * Ascii internet address interpretation routine. 45 * The value returned is in network order. 46 */ 47u_long 48inet_addr(cp) 49 register const char *cp; 50{ 51 struct in_addr val; 52 53 if (inet_aton(cp, &val)) 54 return (val.s_addr); 55 return (INADDR_NONE); 56} 57 58/* 59 * Check whether "cp" is a valid ascii representation 60 * of an Internet address and convert to a binary address. 61 * Returns 1 if the address is valid, 0 if not. 62 * This replaces inet_addr, the return value from which 63 * cannot distinguish between failure and a local broadcast address. 64 */ 65int 66inet_aton(cp, addr) 67 register const char *cp; 68 struct in_addr *addr; 69{ 70 register u_long val; 71 register int base, n; 72 register char c; 73 u_int parts[4]; 74 register u_int *pp = parts; 75 76 for (;;) { 77 /* 78 * Collect number up to ``.''. 79 * Values are specified as for C: 80 * 0x=hex, 0=octal, other=decimal. 81 */ 82 val = 0; base = 10; 83 if (*cp == '0') { 84 if (*++cp == 'x' || *cp == 'X') 85 base = 16, cp++; 86 else 87 base = 8; 88 } 89 while ((c = *cp) != '\0') { 90 if (isascii(c) && isdigit(c)) { 91 val = (val * base) + (c - '0'); 92 cp++; 93 continue; 94 } 95 if (base == 16 && isascii(c) && isxdigit(c)) { 96 val = (val << 4) + 97 (c + 10 - (islower(c) ? 'a' : 'A')); 98 cp++; 99 continue; 100 } 101 break; 102 } 103 if (*cp == '.') { 104 /* 105 * Internet format: 106 * a.b.c.d 107 * a.b.c (with c treated as 16-bits) 108 * a.b (with b treated as 24 bits) 109 */ 110 if (pp >= parts + 3 || val > 0xff) 111 return (0); 112 *pp++ = val, cp++; 113 } else 114 break; 115 } 116 /* 117 * Check for trailing characters. 118 */ 119 if (*cp && (!isascii(*cp) || !isspace(*cp))) 120 return (0); 121 /* 122 * Concoct the address according to 123 * the number of parts specified. 124 */ 125 n = pp - parts + 1; 126 switch (n) { 127 128 case 0: 129 return (0); /* initial nondigit */ 130 131 case 1: /* a -- 32 bits */ 132 break; 133 134 case 2: /* a.b -- 8.24 bits */ 135 if (val > 0xffffff) 136 return (0); 137 val |= parts[0] << 24; 138 break; 139 140 case 3: /* a.b.c -- 8.8.16 bits */ 141 if (val > 0xffff) 142 return (0); 143 val |= (parts[0] << 24) | (parts[1] << 16); 144 break; 145 146 case 4: /* a.b.c.d -- 8.8.8.8 bits */ 147 if (val > 0xff) 148 return (0); 149 val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8); 150 break; 151 } 152 if (addr) 153 addr->s_addr = htonl(val); 154 return (1); 155} 156