1d7ce700605e1af0e455e31ec11f19ff21d26b525darylm/*
2d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * Copyright (c) 1996 by Internet Software Consortium.
3d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *
4d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * Permission to use, copy, modify, and distribute this software for any
5d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * purpose with or without fee is hereby granted, provided that the above
6d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * copyright notice and this permission notice appear in all copies.
7d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *
8d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
9d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
10d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
11d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
12d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
13d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
14d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
15d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * SOFTWARE.
16d7ce700605e1af0e455e31ec11f19ff21d26b525darylm */
17d7ce700605e1af0e455e31ec11f19ff21d26b525darylm
18d7ce700605e1af0e455e31ec11f19ff21d26b525darylm/*
19d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * Portions copyright (c) 1999, 2000
20d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * Intel Corporation.
21d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * All rights reserved.
22d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *
23d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * Redistribution and use in source and binary forms, with or without
24d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * modification, are permitted provided that the following conditions
25d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * are met:
26d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *
27d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * 1. Redistributions of source code must retain the above copyright
28d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *    notice, this list of conditions and the following disclaimer.
29d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *
30d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * 2. Redistributions in binary form must reproduce the above copyright
31d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *    notice, this list of conditions and the following disclaimer in the
32d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *    documentation and/or other materials provided with the distribution.
33d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *
34d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * 3. All advertising materials mentioning features or use of this software
35d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *    must display the following acknowledgement:
36d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *
37d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *    This product includes software developed by Intel Corporation and
38d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *    its contributors.
39d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *
40d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * 4. Neither the name of Intel Corporation or its contributors may be
41d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *    used to endorse or promote products derived from this software
42d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *    without specific prior written permission.
43d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *
44d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * THIS SOFTWARE IS PROVIDED BY INTEL CORPORATION AND CONTRIBUTORS ``AS IS''
45d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
46d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
47d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * ARE DISCLAIMED.  IN NO EVENT SHALL INTEL CORPORATION OR CONTRIBUTORS BE
48d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
49d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
50d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
51d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
52d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
53d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
54d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * THE POSSIBILITY OF SUCH DAMAGE.
55d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *
56d7ce700605e1af0e455e31ec11f19ff21d26b525darylm */
57d7ce700605e1af0e455e31ec11f19ff21d26b525darylm
58d7ce700605e1af0e455e31ec11f19ff21d26b525darylm#if defined(LIBC_SCCS) && !defined(lint)
59d7ce700605e1af0e455e31ec11f19ff21d26b525darylmstatic const char orig_rcsid[] = "From Id: inet_net_pton.c,v 1.8 1996/11/21 10:28:12 vixie Exp $";
60d7ce700605e1af0e455e31ec11f19ff21d26b525darylmstatic const char rcsid[] = "$Id: inet_net_pton.c,v 1.1.1.1 2003/11/19 01:51:29 kyu3 Exp $";
61d7ce700605e1af0e455e31ec11f19ff21d26b525darylm#endif
62d7ce700605e1af0e455e31ec11f19ff21d26b525darylm
63d7ce700605e1af0e455e31ec11f19ff21d26b525darylm#include <sys/types.h>
64d7ce700605e1af0e455e31ec11f19ff21d26b525darylm#include <sys/socket.h>
65d7ce700605e1af0e455e31ec11f19ff21d26b525darylm#include <netinet/in.h>
66d7ce700605e1af0e455e31ec11f19ff21d26b525darylm#include <arpa/inet.h>
67d7ce700605e1af0e455e31ec11f19ff21d26b525darylm
68d7ce700605e1af0e455e31ec11f19ff21d26b525darylm#include <assert.h>
69d7ce700605e1af0e455e31ec11f19ff21d26b525darylm#include <ctype.h>
70d7ce700605e1af0e455e31ec11f19ff21d26b525darylm#include <errno.h>
71d7ce700605e1af0e455e31ec11f19ff21d26b525darylm#include <stdio.h>
72d7ce700605e1af0e455e31ec11f19ff21d26b525darylm#include <string.h>
73d7ce700605e1af0e455e31ec11f19ff21d26b525darylm#include <stdlib.h>
74d7ce700605e1af0e455e31ec11f19ff21d26b525darylm
75d7ce700605e1af0e455e31ec11f19ff21d26b525darylm#ifdef SPRINTF_CHAR
76d7ce700605e1af0e455e31ec11f19ff21d26b525darylm# define SPRINTF(x) strlen(sprintf/**/x)
77d7ce700605e1af0e455e31ec11f19ff21d26b525darylm#else
78d7ce700605e1af0e455e31ec11f19ff21d26b525darylm# define SPRINTF(x) ((size_t)sprintf x)
79d7ce700605e1af0e455e31ec11f19ff21d26b525darylm#endif
80d7ce700605e1af0e455e31ec11f19ff21d26b525darylm
81d7ce700605e1af0e455e31ec11f19ff21d26b525darylmstatic int	inet_net_pton_ipv4 (const char *src, u_char *dst,
82d7ce700605e1af0e455e31ec11f19ff21d26b525darylm					size_t size);
83d7ce700605e1af0e455e31ec11f19ff21d26b525darylm
84d7ce700605e1af0e455e31ec11f19ff21d26b525darylm/*
85d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * static int
86d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * inet_net_pton(af, src, dst, size)
87d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *	convert network number from presentation to network format.
88d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *	accepts hex octets, hex strings, decimal octets, and /CIDR.
89d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *	"size" is in bytes and describes "dst".
90d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * return:
91d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *	number of bits, either imputed classfully or specified with /CIDR,
92d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *	or -1 if some failure occurred (check errno).  ENOENT means it was
93d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *	not a valid network specification.
94d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * author:
95d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *	Paul Vixie (ISC), June 1996
96d7ce700605e1af0e455e31ec11f19ff21d26b525darylm */
97d7ce700605e1af0e455e31ec11f19ff21d26b525darylmint
98d7ce700605e1af0e455e31ec11f19ff21d26b525darylminet_net_pton(
99d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	int af,
100d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	const char *src,
101d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	void *dst,
102d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	size_t size
103d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	)
104d7ce700605e1af0e455e31ec11f19ff21d26b525darylm{
105d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	switch (af) {
106d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	case AF_INET:
107d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		return (inet_net_pton_ipv4(src, dst, size));
108d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	default:
109d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		errno = EAFNOSUPPORT;
110d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		return (-1);
111d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	}
112d7ce700605e1af0e455e31ec11f19ff21d26b525darylm}
113d7ce700605e1af0e455e31ec11f19ff21d26b525darylm
114d7ce700605e1af0e455e31ec11f19ff21d26b525darylm/*
115d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * static int
116d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * inet_net_pton_ipv4(src, dst, size)
117d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *	convert IPv4 network number from presentation to network format.
118d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *	accepts hex octets, hex strings, decimal octets, and /CIDR.
119d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *	"size" is in bytes and describes "dst".
120d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * return:
121d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *	number of bits, either imputed classfully or specified with /CIDR,
122d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *	or -1 if some failure occurred (check errno).  ENOENT means it was
123d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *	not an IPv4 network specification.
124d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * note:
125d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *	network byte order assumed.  this means 192.5.5.240/28 has
126d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *	0x11110000 in its fourth octet.
127d7ce700605e1af0e455e31ec11f19ff21d26b525darylm * author:
128d7ce700605e1af0e455e31ec11f19ff21d26b525darylm *	Paul Vixie (ISC), June 1996
129d7ce700605e1af0e455e31ec11f19ff21d26b525darylm */
130d7ce700605e1af0e455e31ec11f19ff21d26b525darylmstatic int
131d7ce700605e1af0e455e31ec11f19ff21d26b525darylminet_net_pton_ipv4(
132d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	const char *src,
133d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	u_char *dst,
134d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	size_t size
135d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	)
136d7ce700605e1af0e455e31ec11f19ff21d26b525darylm{
137d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	static const char xdigits[] = "0123456789abcdef";
138d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	static const char digits[] = "0123456789";
139d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	int n;
140d7ce700605e1af0e455e31ec11f19ff21d26b525darylm  int ch;
141d7ce700605e1af0e455e31ec11f19ff21d26b525darylm  int tmp;
142d7ce700605e1af0e455e31ec11f19ff21d26b525darylm  int dirty;
143d7ce700605e1af0e455e31ec11f19ff21d26b525darylm  int bits;
144d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	const u_char *odst = dst;
145d7ce700605e1af0e455e31ec11f19ff21d26b525darylm
146d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	ch = *src++;
147d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	if (ch == '0' && (src[0] == 'x' || src[0] == 'X')
148d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	    && isascii(src[1]) && isxdigit(src[1])) {
149d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		/* Hexadecimal: Eat nybble string. */
150d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		if (size <= 0)
151d7ce700605e1af0e455e31ec11f19ff21d26b525darylm			goto emsgsize;
152d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		*dst = 0, dirty = 0;
153d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		src++;	/* skip x or X. */
154d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		while ((ch = *src++) != '\0' &&
155d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		       isascii(ch) && isxdigit(ch)) {
156d7ce700605e1af0e455e31ec11f19ff21d26b525darylm			if (isupper(ch))
157d7ce700605e1af0e455e31ec11f19ff21d26b525darylm				ch = tolower(ch);
158d7ce700605e1af0e455e31ec11f19ff21d26b525darylm			n = (int)(strchr(xdigits, ch) - xdigits);
159d7ce700605e1af0e455e31ec11f19ff21d26b525darylm			assert(n >= 0 && n <= 15);
160d7ce700605e1af0e455e31ec11f19ff21d26b525darylm			*dst |= n;
161d7ce700605e1af0e455e31ec11f19ff21d26b525darylm			if (!dirty++)
162d7ce700605e1af0e455e31ec11f19ff21d26b525darylm				*dst <<= 4;
163d7ce700605e1af0e455e31ec11f19ff21d26b525darylm			else if (size-- > 0)
164d7ce700605e1af0e455e31ec11f19ff21d26b525darylm				*++dst = 0, dirty = 0;
165d7ce700605e1af0e455e31ec11f19ff21d26b525darylm			else
166d7ce700605e1af0e455e31ec11f19ff21d26b525darylm				goto emsgsize;
167d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		}
168d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		if (dirty)
169d7ce700605e1af0e455e31ec11f19ff21d26b525darylm			size--;
170d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	} else if (isascii(ch) && isdigit(ch)) {
171d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		/* Decimal: eat dotted digit string. */
172d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		for (;;) {
173d7ce700605e1af0e455e31ec11f19ff21d26b525darylm			tmp = 0;
174d7ce700605e1af0e455e31ec11f19ff21d26b525darylm			do {
175d7ce700605e1af0e455e31ec11f19ff21d26b525darylm				n = (int)(strchr(digits, ch) - digits);
176d7ce700605e1af0e455e31ec11f19ff21d26b525darylm				assert(n >= 0 && n <= 9);
177d7ce700605e1af0e455e31ec11f19ff21d26b525darylm				tmp *= 10;
178d7ce700605e1af0e455e31ec11f19ff21d26b525darylm				tmp += n;
179d7ce700605e1af0e455e31ec11f19ff21d26b525darylm				if (tmp > 255)
180d7ce700605e1af0e455e31ec11f19ff21d26b525darylm					goto enoent;
181d7ce700605e1af0e455e31ec11f19ff21d26b525darylm			} while ((ch = *src++) != '\0' &&
182d7ce700605e1af0e455e31ec11f19ff21d26b525darylm				 isascii(ch) && isdigit(ch));
183d7ce700605e1af0e455e31ec11f19ff21d26b525darylm			if (size-- <= 0)
184d7ce700605e1af0e455e31ec11f19ff21d26b525darylm				goto emsgsize;
185d7ce700605e1af0e455e31ec11f19ff21d26b525darylm			*dst++ = (u_char) tmp;
186d7ce700605e1af0e455e31ec11f19ff21d26b525darylm			if (ch == '\0' || ch == '/')
187d7ce700605e1af0e455e31ec11f19ff21d26b525darylm				break;
188d7ce700605e1af0e455e31ec11f19ff21d26b525darylm			if (ch != '.')
189d7ce700605e1af0e455e31ec11f19ff21d26b525darylm				goto enoent;
190d7ce700605e1af0e455e31ec11f19ff21d26b525darylm			ch = *src++;
191d7ce700605e1af0e455e31ec11f19ff21d26b525darylm			if (!isascii(ch) || !isdigit(ch))
192d7ce700605e1af0e455e31ec11f19ff21d26b525darylm				goto enoent;
193d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		}
194d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	} else
195d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		goto enoent;
196d7ce700605e1af0e455e31ec11f19ff21d26b525darylm
197d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	bits = -1;
198d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	if (ch == '/' && isascii(src[0]) && isdigit(src[0]) && dst > odst) {
199d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		/* CIDR width specifier.  Nothing can follow it. */
200d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		ch = *src++;	/* Skip over the /. */
201d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		bits = 0;
202d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		do {
203d7ce700605e1af0e455e31ec11f19ff21d26b525darylm			n = (int)(strchr(digits, ch) - digits);
204d7ce700605e1af0e455e31ec11f19ff21d26b525darylm			assert(n >= 0 && n <= 9);
205d7ce700605e1af0e455e31ec11f19ff21d26b525darylm			bits *= 10;
206d7ce700605e1af0e455e31ec11f19ff21d26b525darylm			bits += n;
207d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		} while ((ch = *src++) != '\0' && isascii(ch) && isdigit(ch));
208d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		if (ch != '\0')
209d7ce700605e1af0e455e31ec11f19ff21d26b525darylm			goto enoent;
210d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		if (bits > 32)
211d7ce700605e1af0e455e31ec11f19ff21d26b525darylm			goto emsgsize;
212d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	}
213d7ce700605e1af0e455e31ec11f19ff21d26b525darylm
214d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	/* Firey death and destruction unless we prefetched EOS. */
215d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	if (ch != '\0')
216d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		goto enoent;
217d7ce700605e1af0e455e31ec11f19ff21d26b525darylm
218d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	/* If nothing was written to the destination, we found no address. */
219d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	if (dst == odst)
220d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		goto enoent;
221d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	/* If no CIDR spec was given, infer width from net class. */
222d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	if (bits == -1) {
223d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		if (*odst >= 240)	/* Class E */
224d7ce700605e1af0e455e31ec11f19ff21d26b525darylm			bits = 32;
225d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		else if (*odst >= 224)	/* Class D */
226d7ce700605e1af0e455e31ec11f19ff21d26b525darylm			bits = 4;
227d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		else if (*odst >= 192)	/* Class C */
228d7ce700605e1af0e455e31ec11f19ff21d26b525darylm			bits = 24;
229d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		else if (*odst >= 128)	/* Class B */
230d7ce700605e1af0e455e31ec11f19ff21d26b525darylm			bits = 16;
231d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		else			/* Class A */
232d7ce700605e1af0e455e31ec11f19ff21d26b525darylm			bits = 8;
233d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		/* If imputed mask is narrower than specified octets, widen. */
234d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		if (bits >= 8 && bits < ((dst - odst) * 8))
235d7ce700605e1af0e455e31ec11f19ff21d26b525darylm			bits = (int)(dst - odst) * 8;
236d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	}
237d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	/* Extend network to cover the actual mask. */
238d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	while (bits > ((dst - odst) * 8)) {
239d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		if (size-- <= 0)
240d7ce700605e1af0e455e31ec11f19ff21d26b525darylm			goto emsgsize;
241d7ce700605e1af0e455e31ec11f19ff21d26b525darylm		*dst++ = '\0';
242d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	}
243d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	return (bits);
244d7ce700605e1af0e455e31ec11f19ff21d26b525darylm
245d7ce700605e1af0e455e31ec11f19ff21d26b525darylm enoent:
246d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	errno = ENOENT;
247d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	return (-1);
248d7ce700605e1af0e455e31ec11f19ff21d26b525darylm
249d7ce700605e1af0e455e31ec11f19ff21d26b525darylm emsgsize:
250d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	errno = EMSGSIZE;
251d7ce700605e1af0e455e31ec11f19ff21d26b525darylm	return (-1);
252d7ce700605e1af0e455e31ec11f19ff21d26b525darylm}
253