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Annotation of 43BSDTahoe/lib/libc/inet/inet_addr.c, revision 1.1.1.1

1.1       root        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) 6/27/88";
                     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: }

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