2 * Copyright (c) 1983, 1990, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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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
34 /* Software engineering face-lift by Greg J. Badros, 11-Dec-1999,
35 gjb@cs.washington.edu, http://www.cs.washington.edu/homes/gjb */
37 #if defined(LIBC_SCCS) && !defined(lint)
38 static char sccsid
[] = "@(#)inet_addr.c 8.1 (Berkeley) 6/17/93";
39 #endif /* LIBC_SCCS and not lint */
43 #include <sys/param.h>
44 #include <netinet/in.h>
45 #include <arpa/inet.h>
50 * Ascii internet address interpretation routine.
51 * The value returned is in network order.
54 inet_addr(const char *cp
)
58 if (inet_aton(cp
, &val
))
65 /* We provide this prototype to avoid compiler warnings. If this ever
66 conflicts with a declaration in a system header file, we'll find
67 out, because we should include that header file here. */
68 int inet_aton (const char *cp
, struct in_addr
*addr
);
71 * Check whether "cp" is a valid ascii representation
72 * of an Internet address and convert to a binary address.
73 * Returns 1 if the address is valid, 0 if not.
74 * This replaces inet_addr, the return value from which
75 * cannot distinguish between failure and a local broadcast address. */
77 inet_aton(const char *cp_arg
, struct in_addr
*addr
)
79 register unsigned long val
;
81 register unsigned char c
;
82 register unsigned const char *cp
= cp_arg
;
83 unsigned int parts
[4];
84 register unsigned int *pp
= parts
;
88 * Collect number up to ``.''.
89 * Values are specified as for C:
90 * 0x=hex, 0=octal, other=decimal.
94 if (*++cp
== 'x' || *cp
== 'X')
99 while ((c
= *cp
) != '\0') {
100 if (isascii(c
) && isdigit(c
)) {
101 val
= (val
* base
) + (c
- '0');
105 if (base
== 16 && isascii(c
) && isxdigit(c
)) {
107 (c
+ 10 - (islower(c
) ? 'a' : 'A'));
117 * a.b.c (with c treated as 16-bits)
118 * a.b (with b treated as 24 bits)
120 if (pp
>= parts
+ 3 || val
> 0xff)
127 * Check for trailing characters.
129 if (*cp
&& (!isascii(*cp
) || !isspace(*cp
)))
132 * Concoct the address according to
133 * the number of parts specified.
138 case 1: /* a -- 32 bits */
141 case 2: /* a.b -- 8.24 bits */
144 val
|= parts
[0] << 24;
147 case 3: /* a.b.c -- 8.8.16 bits */
150 val
|= (parts
[0] << 24) | (parts
[1] << 16);
153 case 4: /* a.b.c.d -- 8.8.8.8 bits */
156 val
|= (parts
[0] << 24) | (parts
[1] << 16) | (parts
[2] << 8);
160 addr
->s_addr
= htonl(val
);