inet_addr.c revision 1.2
1/* $NetBSD: inet_addr.c,v 1.6 1996/02/02 15:22:23 mrg Exp $ */ 2 3/* 4 * Copyright (c) 1983, 1990, 1993 5 * The Regents of the University of California. 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 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36#if defined(LIBC_SCCS) && !defined(lint) 37#if 0 38static char sccsid[] = "@(#)inet_addr.c 8.1 (Berkeley) 6/17/93"; 39#else 40static char rcsid[] = "$NetBSD: inet_addr.c,v 1.6 1996/02/02 15:22:23 mrg Exp $"; 41#endif 42#endif /* LIBC_SCCS and not lint */ 43 44#include <sys/param.h> 45#include <netinet/in.h> 46#include <arpa/inet.h> 47#include <ctype.h> 48 49/* 50 * Ascii internet address interpretation routine. 51 * The value returned is in network order. 52 */ 53u_long 54inet_addr(cp) 55 register const char *cp; 56{ 57 struct in_addr val; 58 59 if (inet_aton(cp, &val)) 60 return (val.s_addr); 61 return (INADDR_NONE); 62} 63 64/* 65 * Check whether "cp" is a valid ascii representation 66 * of an Internet address and convert to a binary address. 67 * Returns 1 if the address is valid, 0 if not. 68 * This replaces inet_addr, the return value from which 69 * cannot distinguish between failure and a local broadcast address. 70 */ 71int 72inet_aton(cp, addr) 73 register const char *cp; 74 struct in_addr *addr; 75{ 76 register u_long val; 77 register int base, n; 78 register char c; 79 u_int parts[4]; 80 register u_int *pp = parts; 81 82 for (;;) { 83 /* 84 * Collect number up to ``.''. 85 * Values are specified as for C: 86 * 0x=hex, 0=octal, other=decimal. 87 */ 88 val = 0; base = 10; 89 if (*cp == '0') { 90 if (*++cp == 'x' || *cp == 'X') 91 base = 16, cp++; 92 else 93 base = 8; 94 } 95 while ((c = *cp) != '\0') { 96 if (isascii(c) && isdigit(c)) { 97 val = (val * base) + (c - '0'); 98 cp++; 99 continue; 100 } 101 if (base == 16 && isascii(c) && isxdigit(c)) { 102 val = (val << 4) + 103 (c + 10 - (islower(c) ? 'a' : 'A')); 104 cp++; 105 continue; 106 } 107 break; 108 } 109 if (*cp == '.') { 110 /* 111 * Internet format: 112 * a.b.c.d 113 * a.b.c (with c treated as 16-bits) 114 * a.b (with b treated as 24 bits) 115 */ 116 if (pp >= parts + 3 || val > 0xff) 117 return (0); 118 *pp++ = val, cp++; 119 } else 120 break; 121 } 122 /* 123 * Check for trailing characters. 124 */ 125 if (*cp && (!isascii(*cp) || !isspace(*cp))) 126 return (0); 127 /* 128 * Concoct the address according to 129 * the number of parts specified. 130 */ 131 n = pp - parts + 1; 132 switch (n) { 133 134 case 0: 135 return (0); /* initial nondigit */ 136 137 case 1: /* a -- 32 bits */ 138 break; 139 140 case 2: /* a.b -- 8.24 bits */ 141 if (val > 0xffffff) 142 return (0); 143 val |= parts[0] << 24; 144 break; 145 146 case 3: /* a.b.c -- 8.8.16 bits */ 147 if (val > 0xffff) 148 return (0); 149 val |= (parts[0] << 24) | (parts[1] << 16); 150 break; 151 152 case 4: /* a.b.c.d -- 8.8.8.8 bits */ 153 if (val > 0xff) 154 return (0); 155 val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8); 156 break; 157 } 158 if (addr) 159 addr->s_addr = htonl(val); 160 return (1); 161} 162