xref: /titanic_41/usr/src/lib/libnsl/rpc/inet_ntoa.c (revision 5aefb6555731130ca4fd295960123d71f2d21fe8)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 
23 /*
24  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
25  * Use is subject to license terms.
26  */
27 
28 /* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
29 /* All Rights Reserved */
30 /*
31  * Portions of this source code were derived from Berkeley
32  * 4.3 BSD under license from the Regents of the University of
33  * California.
34  */
35 
36 #pragma ident	"%Z%%M%	%I%	%E% SMI"
37 
38 /*
39  * Convert network-format internet address
40  * to base 256 d.d.d.d representation.
41  *
42  * Reentrant interface
43  */
44 
45 #pragma weak inet_aton = _inet_aton
46 
47 #include "mt.h"
48 #include "rpc_mt.h"
49 #include <errno.h>
50 #include <sys/types.h>
51 #include <ctype.h>
52 #include <netinet/in.h>
53 #include <stdio.h>
54 #include <stdlib.h>
55 
56 
57 char *
58 inet_ntoa_r(in, b)
59 	struct in_addr in;
60 	char	b[];	/* Assumed >= 18 bytes */
61 {
62 	char	*p;
63 
64 	p = (char *)&in;
65 #define	UC(b)	(((int)b)&0xff)
66 	(void) sprintf(b, "%d.%d.%d.%d",
67 				UC(p[0]), UC(p[1]), UC(p[2]), UC(p[3]));
68 	return (b);
69 }
70 
71 char *
72 inet_ntoa(in)
73 	struct in_addr in;
74 {
75 	char *b;
76 	static char b_main[18];
77 	static pthread_key_t ntoa_key;
78 
79 	if (thr_main())
80 		b = b_main;
81 	else if ((b = thr_get_storage(&ntoa_key, 18, free)) == NULL)
82 		b = b_main;
83 
84 	return (inet_ntoa_r(in, b));
85 }
86 
87 /*
88  * Check whether "cp" is a valid ascii representation
89  * of an Internet address and convert to a binary address.
90  * Returns 1 if the address is valid, 0 if not.
91  * This replaces inet_addr, the return value from which
92  * cannot distinguish between failure and a local broadcast address.
93  */
94 int
95 inet_aton(const char *cp, struct in_addr *addr)
96 {
97 	uint32_t val;
98 	int base, n;
99 	char c;
100 	unsigned int parts[4];
101 	unsigned int *pp = parts;
102 
103 
104 	c = *cp;
105 	for (;;) {
106 		/*
107 		 * Collect number up to ``.''.
108 		 * Values are specified as for C:
109 		 * 0x=hex, 0=octal, isdigit=decimal.
110 		 */
111 		if (!isdigit(c))
112 			return (0);
113 		val = 0; base = 10;
114 		if (c == '0') {
115 			c = *++cp;
116 			if (c == 'x' || c == 'X')
117 				base = 16, c = *++cp;
118 			else
119 				base = 8;
120 		}
121 		for (;;) {
122 			if (isascii(c) && isdigit(c)) {
123 				val = (val * base) + (c - '0');
124 				c = *++cp;
125 			} else if (base == 16 && isascii(c) && isxdigit(c)) {
126 				val = (val << 4) |
127 					(c + 10 - (islower(c) ? 'a' : 'A'));
128 				c = *++cp;
129 			} else
130 				break;
131 		}
132 		if (c == '.') {
133 			/*
134 			 * Internet format:
135 			 *	a.b.c.d
136 			 *	a.b.c	(with c treated as 16 bits)
137 			 *	a.b	(with b treated as 24 bits)
138 			 */
139 			if (pp >= parts + 3)
140 				return (0);
141 			*pp++ = val;
142 			c = *++cp;
143 		} else
144 			break;
145 	}
146 	/*
147 	 * Check for trailing characters.
148 	 */
149 	if (c != '\0' && (!isascii(c) || !isspace(c)))
150 		return (0);
151 	/*
152 	 * Concoct the address according to
153 	 * the number of parts specified.
154 	 */
155 	n = pp - parts + 1;
156 	switch (n) {
157 
158 	case 0:
159 		return (0);		/* initial nondigit */
160 
161 	case 1:				/* a -- 32 bits */
162 		break;
163 
164 	case 2:				/* a.b -- 8.24 bits */
165 		if ((val > 0xffffff) || (parts[0] > 0xff))
166 			return (0);
167 		val |= parts[0] << 24;
168 		break;
169 
170 	case 3:				/* a.b.c -- 8.8.16 bits */
171 		if ((val > 0xffff) || (parts[0] > 0xff) || (parts[1] > 0xff))
172 			return (0);
173 		val |= (parts[0] << 24) | (parts[1] << 16);
174 		break;
175 
176 	case 4:				/* a.b.c.d -- 8.8.8.8 bits */
177 		if ((val > 0xff) || (parts[0] > 0xff) || (parts[1] > 0xff) ||
178 		    (parts[2] > 0xff))
179 			return (0);
180 		val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
181 		break;
182 	}
183 	if (addr)
184 		addr->s_addr = htonl(val);
185 	return (1);
186 }
187 
188 /*
189  * Internet address interpretation routine.
190  * All the network library routines call this
191  * routine to interpret entries in the data bases
192  * which are expected to be an address.
193  * The value returned is in network order.
194  */
195 in_addr_t
196 inet_addr(const char *cp)
197 {
198 	struct in_addr val;
199 
200 	if (inet_aton(cp, &val))
201 		return (val.s_addr);
202 	return (INADDR_NONE);
203 }
204 
205 /*
206  * Return the network number from an internet
207  * address; handles class a/b/c network #'s.
208  */
209 uint_t
210 inet_netof(struct in_addr in)
211 {
212 	uint32_t i = ntohl(in.s_addr);
213 
214 	if (IN_CLASSA(i))
215 		return ((i & IN_CLASSA_NET) >> IN_CLASSA_NSHIFT);
216 	if (IN_CLASSB(i))
217 		return ((i & IN_CLASSB_NET) >> IN_CLASSB_NSHIFT);
218 	return ((i & IN_CLASSC_NET) >> IN_CLASSC_NSHIFT);
219 }
220