4.3BSD - /usr/src/lib/libc/inet/inet_addr.c

   1: /*
   2:  * Copyright (c) 1983 Regents of the University of California.
   3:  * All rights reserved.  The Berkeley software License Agreement
   4:  * specifies the terms and conditions for redistribution.
   5:  */
   6: 
   7: #if defined(LIBC_SCCS) && !defined(lint)
   8: static char sccsid[] = "@(#)inet_addr.c	5.2 (Berkeley) 3/9/86";
   9: #endif LIBC_SCCS and not lint
  10: 
  11: #include <sys/types.h>
  12: #include <ctype.h>
  13: #include <netinet/in.h>
  14: 
  15: /*
  16:  * Internet address interpretation routine.
  17:  * All the network library routines call this
  18:  * routine to interpret entries in the data bases
  19:  * which are expected to be an address.
  20:  * The value returned is in network order.
  21:  */
  22: u_long
  23: inet_addr(cp)
  24:     register char *cp;
  25: {
  26:     register u_long val, base, n;
  27:     register char c;
  28:     u_long parts[4], *pp = parts;
  29: 
  30: again:
  31:     /*
  32: 	 * Collect number up to ``.''.
  33: 	 * Values are specified as for C:
  34: 	 * 0x=hex, 0=octal, other=decimal.
  35: 	 */
  36:     val = 0; base = 10;
  37:     if (*cp == '0')
  38:         base = 8, cp++;
  39:     if (*cp == 'x' || *cp == 'X')
  40:         base = 16, cp++;
  41:     while (c = *cp) {
  42:         if (isdigit(c)) {
  43:             val = (val * base) + (c - '0');
  44:             cp++;
  45:             continue;
  46:         }
  47:         if (base == 16 && isxdigit(c)) {
  48:             val = (val << 4) + (c + 10 - (islower(c) ? 'a' : 'A'));
  49:             cp++;
  50:             continue;
  51:         }
  52:         break;
  53:     }
  54:     if (*cp == '.') {
  55:         /*
  56: 		 * Internet format:
  57: 		 *	a.b.c.d
  58: 		 *	a.b.c	(with c treated as 16-bits)
  59: 		 *	a.b	(with b treated as 24 bits)
  60: 		 */
  61:         if (pp >= parts + 4)
  62:             return (-1);
  63:         *pp++ = val, cp++;
  64:         goto again;
  65:     }
  66:     /*
  67: 	 * Check for trailing characters.
  68: 	 */
  69:     if (*cp && !isspace(*cp))
  70:         return (-1);
  71:     *pp++ = val;
  72:     /*
  73: 	 * Concoct the address according to
  74: 	 * the number of parts specified.
  75: 	 */
  76:     n = pp - parts;
  77:     switch (n) {
  78: 
  79:     case 1:             /* a -- 32 bits */
  80:         val = parts[0];
  81:         break;
  82: 
  83:     case 2:             /* a.b -- 8.24 bits */
  84:         val = (parts[0] << 24) | (parts[1] & 0xffffff);
  85:         break;
  86: 
  87:     case 3:             /* a.b.c -- 8.8.16 bits */
  88:         val = (parts[0] << 24) | ((parts[1] & 0xff) << 16) |
  89:             (parts[2] & 0xffff);
  90:         break;
  91: 
  92:     case 4:             /* a.b.c.d -- 8.8.8.8 bits */
  93:         val = (parts[0] << 24) | ((parts[1] & 0xff) << 16) |
  94:               ((parts[2] & 0xff) << 8) | (parts[3] & 0xff);
  95:         break;
  96: 
  97:     default:
  98:         return (-1);
  99:     }
 100:     val = htonl(val);
 101:     return (val);
 102: }

Defined functions

Defined variables