1 /* 2 * Copyright (c) 1983 Regents of the University of California. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms are permitted 6 * provided that the above copyright notice and this paragraph are 7 * duplicated in all such forms and that any documentation, 8 * advertising materials, and other materials related to such 9 * distribution and use acknowledge that the software was developed 10 * by the University of California, Berkeley. The name of the 11 * University may not be used to endorse or promote products derived 12 * from this software without specific prior written permission. 13 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 14 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 15 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 16 */ 17 18 #if defined(LIBC_SCCS) && !defined(lint) 19 static char sccsid[] = "@(#)inet_addr.c 5.6 (Berkeley) 06/27/88"; 20 #endif /* LIBC_SCCS and not lint */ 21 22 #include <sys/types.h> 23 #include <ctype.h> 24 #include <netinet/in.h> 25 26 /* 27 * Internet address interpretation routine. 28 * All the network library routines call this 29 * routine to interpret entries in the data bases 30 * which are expected to be an address. 31 * The value returned is in network order. 32 */ 33 u_long 34 inet_addr(cp) 35 register char *cp; 36 { 37 register u_long val, base, n; 38 register char c; 39 u_long parts[4], *pp = parts; 40 41 again: 42 /* 43 * Collect number up to ``.''. 44 * Values are specified as for C: 45 * 0x=hex, 0=octal, other=decimal. 46 */ 47 val = 0; base = 10; 48 if (*cp == '0') { 49 if (*++cp == 'x' || *cp == 'X') 50 base = 16, cp++; 51 else 52 base = 8; 53 } 54 while (c = *cp) { 55 if (isdigit(c)) { 56 val = (val * base) + (c - '0'); 57 cp++; 58 continue; 59 } 60 if (base == 16 && isxdigit(c)) { 61 val = (val << 4) + (c + 10 - (islower(c) ? 'a' : 'A')); 62 cp++; 63 continue; 64 } 65 break; 66 } 67 if (*cp == '.') { 68 /* 69 * Internet format: 70 * a.b.c.d 71 * a.b.c (with c treated as 16-bits) 72 * a.b (with b treated as 24 bits) 73 */ 74 if (pp >= parts + 4) 75 return (INADDR_NONE); 76 *pp++ = val, cp++; 77 goto again; 78 } 79 /* 80 * Check for trailing characters. 81 */ 82 if (*cp && !isspace(*cp)) 83 return (INADDR_NONE); 84 *pp++ = val; 85 /* 86 * Concoct the address according to 87 * the number of parts specified. 88 */ 89 n = pp - parts; 90 switch (n) { 91 92 case 1: /* a -- 32 bits */ 93 val = parts[0]; 94 break; 95 96 case 2: /* a.b -- 8.24 bits */ 97 val = (parts[0] << 24) | (parts[1] & 0xffffff); 98 break; 99 100 case 3: /* a.b.c -- 8.8.16 bits */ 101 val = (parts[0] << 24) | ((parts[1] & 0xff) << 16) | 102 (parts[2] & 0xffff); 103 break; 104 105 case 4: /* a.b.c.d -- 8.8.8.8 bits */ 106 val = (parts[0] << 24) | ((parts[1] & 0xff) << 16) | 107 ((parts[2] & 0xff) << 8) | (parts[3] & 0xff); 108 break; 109 110 default: 111 return (INADDR_NONE); 112 } 113 val = htonl(val); 114 return (val); 115 } 116