xref: /aosp_15_r20/external/cronet/third_party/apache-portable-runtime/src/network_io/unix/inet_ntop.c (revision 6777b5387eb2ff775bb5750e3f5d96f37fb7352b)
1 /* Copyright (c) 1996 by Internet Software Consortium.
2  *
3  * Permission to use, copy, modify, and distribute this software for any
4  * purpose with or without fee is hereby granted, provided that the above
5  * copyright notice and this permission notice appear in all copies.
6  *
7  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
8  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
9  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
10  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
11  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
12  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
13  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
14  * SOFTWARE.
15  */
16 
17 #include "apr_private.h"
18 #include "apr_arch_networkio.h"
19 #include "apr_strings.h"
20 
21 #if APR_HAVE_SYS_TYPES_H
22 #include <sys/types.h>
23 #endif
24 #if APR_HAVE_SYS_SOCKET_H
25 #include <sys/socket.h>
26 #endif
27 #if APR_HAVE_NETINET_IN_H
28 #include <netinet/in.h>
29 #endif
30 #if APR_HAVE_ARPA_INET_H
31 #include <arpa/inet.h>
32 #endif
33 #include <string.h>
34 #if APR_HAVE_ERRNO_H
35 #include <errno.h>
36 #endif
37 #include <stdio.h>
38 
39 #ifndef IN6ADDRSZ
40 #define IN6ADDRSZ   16
41 #endif
42 
43 #ifndef INT16SZ
44 #define INT16SZ sizeof(apr_int16_t)
45 #endif
46 
47 #ifndef __P
48 #define __P(x) x
49 #endif
50 
51 #if !defined(EAFNOSUPPORT) && defined(WSAEAFNOSUPPORT)
52 #define EAFNOSUPPORT WSAEAFNOSUPPORT
53 #endif
54 
55 /*
56  * WARNING: Don't even consider trying to compile this on a system where
57  * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
58  */
59 
60 static const char *inet_ntop4 __P((const unsigned char *src, char *dst, apr_size_t size));
61 #if APR_HAVE_IPV6
62 static const char *inet_ntop6 __P((const unsigned char *src, char *dst, apr_size_t size));
63 #endif
64 
65 /* char *
66  * inet_ntop(af, src, dst, size)
67  *	convert a network format address to presentation format.
68  * return:
69  *	pointer to presentation format address (`dst'), or NULL (see errno).
70  * author:
71  *	Paul Vixie, 1996.
72  */
73 const char *
apr_inet_ntop(int af,const void * src,char * dst,apr_size_t size)74 apr_inet_ntop(int af, const void *src, char *dst, apr_size_t size)
75 {
76 	switch (af) {
77 	case AF_INET:
78 		return (inet_ntop4(src, dst, size));
79 #if APR_HAVE_IPV6
80 	case AF_INET6:
81 		return (inet_ntop6(src, dst, size));
82 #endif
83 	default:
84 		errno = EAFNOSUPPORT;
85 		return (NULL);
86 	}
87 	/* NOTREACHED */
88 }
89 
90 /* const char *
91  * inet_ntop4(src, dst, size)
92  *	format an IPv4 address, more or less like inet_ntoa()
93  * return:
94  *	`dst' (as a const)
95  * notes:
96  *	(1) uses no statics
97  *	(2) takes a u_char* not an in_addr as input
98  * author:
99  *	Paul Vixie, 1996.
100  */
101 static const char *
inet_ntop4(const unsigned char * src,char * dst,apr_size_t size)102 inet_ntop4(const unsigned char *src, char *dst, apr_size_t size)
103 {
104 	const apr_size_t MIN_SIZE = 16; /* space for 255.255.255.255\0 */
105 	int n = 0;
106 	char *next = dst;
107 
108 	if (size < MIN_SIZE) {
109 	    errno = ENOSPC;
110 	    return NULL;
111 	}
112 	do {
113 	    unsigned char u = *src++;
114 	    if (u > 99) {
115 		*next++ = '0' + u/100;
116 		u %= 100;
117 		*next++ = '0' + u/10;
118 		u %= 10;
119 	    }
120 	    else if (u > 9) {
121 		*next++ = '0' + u/10;
122 		u %= 10;
123 	    }
124 	    *next++ = '0' + u;
125 	    *next++ = '.';
126 	    n++;
127 	} while (n < 4);
128 	*--next = 0;
129 	return dst;
130 }
131 
132 #if APR_HAVE_IPV6
133 /* const char *
134  * inet_ntop6(src, dst, size)
135  *	convert IPv6 binary address into presentation (printable) format
136  * author:
137  *	Paul Vixie, 1996.
138  */
139 static const char *
inet_ntop6(const unsigned char * src,char * dst,apr_size_t size)140 inet_ntop6(const unsigned char *src, char *dst, apr_size_t size)
141 {
142     /*
143      * Note that int32_t and int16_t need only be "at least" large enough
144      * to contain a value of the specified size.  On some systems, like
145      * Crays, there is no such thing as an integer variable with 16 bits.
146      * Keep this in mind if you think this function should have been coded
147      * to use pointer overlays.  All the world's not a VAX.
148      */
149     char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"], *tp;
150     struct { int base, len; } best = {-1, 0}, cur = {-1, 0};
151     unsigned int words[IN6ADDRSZ / INT16SZ];
152     int i;
153     const unsigned char *next_src, *src_end;
154     unsigned int *next_dest;
155 
156     /*
157      * Preprocess:
158      *	Copy the input (bytewise) array into a wordwise array.
159      *	Find the longest run of 0x00's in src[] for :: shorthanding.
160      */
161     next_src = src;
162     src_end = src + IN6ADDRSZ;
163     next_dest = words;
164     i = 0;
165     do {
166         unsigned int next_word = (unsigned int)*next_src++;
167         next_word <<= 8;
168         next_word |= (unsigned int)*next_src++;
169         *next_dest++ = next_word;
170 
171         if (next_word == 0) {
172             if (cur.base == -1) {
173                 cur.base = i;
174                 cur.len = 1;
175             }
176             else {
177                 cur.len++;
178             }
179         } else {
180             if (cur.base != -1) {
181                 if (best.base == -1 || cur.len > best.len) {
182                     best = cur;
183                 }
184                 cur.base = -1;
185             }
186         }
187 
188         i++;
189     } while (next_src < src_end);
190 
191     if (cur.base != -1) {
192         if (best.base == -1 || cur.len > best.len) {
193             best = cur;
194         }
195     }
196     if (best.base != -1 && best.len < 2) {
197         best.base = -1;
198     }
199 
200     /*
201      * Format the result.
202      */
203     tp = tmp;
204     for (i = 0; i < (IN6ADDRSZ / INT16SZ);) {
205         /* Are we inside the best run of 0x00's? */
206         if (i == best.base) {
207             *tp++ = ':';
208             i += best.len;
209             continue;
210         }
211         /* Are we following an initial run of 0x00s or any real hex? */
212         if (i != 0) {
213             *tp++ = ':';
214         }
215         /* Is this address an encapsulated IPv4? */
216         if (i == 6 && best.base == 0 &&
217             (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) {
218             if (!inet_ntop4(src+12, tp, sizeof tmp - (tp - tmp))) {
219                 return (NULL);
220             }
221             tp += strlen(tp);
222             break;
223         }
224         tp += apr_snprintf(tp, sizeof tmp - (tp - tmp), "%x", words[i]);
225         i++;
226     }
227     /* Was it a trailing run of 0x00's? */
228     if (best.base != -1 && (best.base + best.len) == (IN6ADDRSZ / INT16SZ)) {
229         *tp++ = ':';
230     }
231     *tp++ = '\0';
232 
233     /*
234      * Check for overflow, copy, and we're done.
235      */
236     if ((apr_size_t)(tp - tmp) > size) {
237         errno = ENOSPC;
238         return (NULL);
239     }
240     strcpy(dst, tmp);
241     return (dst);
242 }
243 #endif
244