ISC DHCP  4.4.3
A reference DHCPv4 and DHCPv6 implementation
inet_addr.c
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1 /* $NetBSD: inet_addr.c,v 1.6 1996/02/02 15:22:23 mrg Exp $ */
2 
3 /*
4  * Copyright (c) 1983, 1990, 1993
5  * The Regents of the University of California. All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  * notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  * notice, this list of conditions and the following disclaimer in the
14  * documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  * may be used to endorse or promote products derived from this software
17  * without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include "dhcpd.h"
33 
34 #include "omapip/omapip_p.h"
35 
36 #ifdef NEED_INET_ATON
37 /*
38  * Check whether "cp" is a valid ascii representation
39  * of an Internet address and convert to a binary address.
40  * Returns 1 if the address is valid, 0 if not.
41  * This replaces inet_addr, the return value from which
42  * cannot distinguish between failure and a local broadcast address.
43  */
44 int
45 inet_aton(cp, addr)
46  const char *cp;
47  struct in_addr *addr;
48 {
49  register u_long val;
50  register int base, n;
51  register char c;
52  u_int parts[4];
53  register u_int *pp = parts;
54 
55  for (;;) {
56  /*
57  * Collect number up to ``.''.
58  * Values are specified as for C:
59  * 0x=hex, 0=octal, other=decimal.
60  */
61  val = 0; base = 10;
62  if (*cp == '0') {
63  if (*++cp == 'x' || *cp == 'X')
64  base = 16, cp++;
65  else
66  base = 8;
67  }
68  while ((c = *cp) != '\0') {
69  if (isascii(c) && isdigit((int)c)) {
70  val = (val * base) + (c - '0');
71  cp++;
72  continue;
73  }
74  if (base == 16 && isascii(c) && isxdigit((int)c)) {
75  val = (val << 4) +
76  (c + 10 - (islower((int)c) ? 'a' : 'A'));
77  cp++;
78  continue;
79  }
80  break;
81  }
82  if (*cp == '.') {
83  /*
84  * Internet format:
85  * a.b.c.d
86  * a.b.c (with c treated as 16-bits)
87  * a.b (with b treated as 24 bits)
88  */
89  if (pp >= parts + 3 || val > 0xff)
90  return (0);
91  *pp++ = val, cp++;
92  } else
93  break;
94  }
95  /*
96  * Check for trailing characters.
97  */
98  if (*cp && (!isascii(*cp) || !isspace((int)*cp)))
99  return (0);
100  /*
101  * Concoct the address according to
102  * the number of parts specified.
103  */
104  n = pp - parts + 1;
105  switch (n) {
106 
107  case 0:
108  return (0); /* initial nondigit */
109 
110  case 1: /* a -- 32 bits */
111  break;
112 
113  case 2: /* a.b -- 8.24 bits */
114  if (val > 0xffffff)
115  return (0);
116  val |= parts[0] << 24;
117  break;
118 
119  case 3: /* a.b.c -- 8.8.16 bits */
120  if (val > 0xffff)
121  return (0);
122  val |= (parts[0] << 24) | (parts[1] << 16);
123  break;
124 
125  case 4: /* a.b.c.d -- 8.8.8.8 bits */
126  if (val > 0xff)
127  return (0);
128  val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
129  break;
130  }
131  if (addr)
132  addr->s_addr = htonl(val);
133  return (1);
134 }
135 #endif