xref: /curl/lib/inet_pton.c (revision f81f351b)
1 /* This is from the BIND 4.9.4 release, modified to compile by itself */
2 
3 /* Copyright (c) Internet Software Consortium.
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
10  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
11  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
12  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
13  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
14  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
15  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
16  * SOFTWARE.
17  *
18  * SPDX-License-Identifier: ISC
19  */
20 
21 #include "curl_setup.h"
22 
23 #ifndef HAVE_INET_PTON
24 
25 #ifdef HAVE_SYS_PARAM_H
26 #include <sys/param.h>
27 #endif
28 #ifdef HAVE_NETINET_IN_H
29 #include <netinet/in.h>
30 #endif
31 #ifdef HAVE_ARPA_INET_H
32 #include <arpa/inet.h>
33 #endif
34 
35 #include "inet_pton.h"
36 
37 #define IN6ADDRSZ       16
38 #define INADDRSZ         4
39 #define INT16SZ          2
40 
41 /*
42  * If USE_IPV6 is disabled, we still want to parse IPv6 addresses, so make
43  * sure we have _some_ value for AF_INET6 without polluting our fake value
44  * everywhere.
45  */
46 #if !defined(USE_IPV6) && !defined(AF_INET6)
47 #define AF_INET6 (AF_INET + 1)
48 #endif
49 
50 /*
51  * WARNING: Do not even consider trying to compile this on a system where
52  * sizeof(int) < 4. sizeof(int) > 4 is fine; all the world's not a VAX.
53  */
54 
55 static int      inet_pton4(const char *src, unsigned char *dst);
56 static int      inet_pton6(const char *src, unsigned char *dst);
57 
58 /* int
59  * inet_pton(af, src, dst)
60  *      convert from presentation format (which usually means ASCII printable)
61  *      to network format (which is usually some kind of binary format).
62  * return:
63  *      1 if the address was valid for the specified address family
64  *      0 if the address was not valid (`dst' is untouched in this case)
65  *      -1 if some other error occurred (`dst' is untouched in this case, too)
66  * notice:
67  *      On Windows we store the error in the thread errno, not
68  *      in the Winsock error code. This is to avoid losing the
69  *      actual last Winsock error. When this function returns
70  *      -1, check errno not SOCKERRNO.
71  * author:
72  *      Paul Vixie, 1996.
73  */
74 int
Curl_inet_pton(int af,const char * src,void * dst)75 Curl_inet_pton(int af, const char *src, void *dst)
76 {
77   switch(af) {
78   case AF_INET:
79     return (inet_pton4(src, (unsigned char *)dst));
80   case AF_INET6:
81     return (inet_pton6(src, (unsigned char *)dst));
82   default:
83     errno = EAFNOSUPPORT;
84     return (-1);
85   }
86   /* NOTREACHED */
87 }
88 
89 /* int
90  * inet_pton4(src, dst)
91  *      like inet_aton() but without all the hexadecimal and shorthand.
92  * return:
93  *      1 if `src' is a valid dotted quad, else 0.
94  * notice:
95  *      does not touch `dst' unless it is returning 1.
96  * author:
97  *      Paul Vixie, 1996.
98  */
99 static int
inet_pton4(const char * src,unsigned char * dst)100 inet_pton4(const char *src, unsigned char *dst)
101 {
102   static const char digits[] = "0123456789";
103   int saw_digit, octets, ch;
104   unsigned char tmp[INADDRSZ], *tp;
105 
106   saw_digit = 0;
107   octets = 0;
108   tp = tmp;
109   *tp = 0;
110   while((ch = *src++) != '\0') {
111     const char *pch;
112 
113     pch = strchr(digits, ch);
114     if(pch) {
115       unsigned int val = (unsigned int)(*tp * 10) +
116                          (unsigned int)(pch - digits);
117 
118       if(saw_digit && *tp == 0)
119         return (0);
120       if(val > 255)
121         return (0);
122       *tp = (unsigned char)val;
123       if(!saw_digit) {
124         if(++octets > 4)
125           return (0);
126         saw_digit = 1;
127       }
128     }
129     else if(ch == '.' && saw_digit) {
130       if(octets == 4)
131         return (0);
132       *++tp = 0;
133       saw_digit = 0;
134     }
135     else
136       return (0);
137   }
138   if(octets < 4)
139     return (0);
140   memcpy(dst, tmp, INADDRSZ);
141   return (1);
142 }
143 
144 /* int
145  * inet_pton6(src, dst)
146  *      convert presentation level address to network order binary form.
147  * return:
148  *      1 if `src' is a valid [RFC1884 2.2] address, else 0.
149  * notice:
150  *      (1) does not touch `dst' unless it is returning 1.
151  *      (2) :: in a full address is silently ignored.
152  * credit:
153  *      inspired by Mark Andrews.
154  * author:
155  *      Paul Vixie, 1996.
156  */
157 static int
inet_pton6(const char * src,unsigned char * dst)158 inet_pton6(const char *src, unsigned char *dst)
159 {
160   static const char xdigits_l[] = "0123456789abcdef",
161     xdigits_u[] = "0123456789ABCDEF";
162   unsigned char tmp[IN6ADDRSZ], *tp, *endp, *colonp;
163   const char *curtok;
164   int ch, saw_xdigit;
165   size_t val;
166 
167   memset((tp = tmp), 0, IN6ADDRSZ);
168   endp = tp + IN6ADDRSZ;
169   colonp = NULL;
170   /* Leading :: requires some special handling. */
171   if(*src == ':')
172     if(*++src != ':')
173       return (0);
174   curtok = src;
175   saw_xdigit = 0;
176   val = 0;
177   while((ch = *src++) != '\0') {
178     const char *xdigits;
179     const char *pch;
180 
181     pch = strchr((xdigits = xdigits_l), ch);
182     if(!pch)
183       pch = strchr((xdigits = xdigits_u), ch);
184     if(pch) {
185       val <<= 4;
186       val |= (pch - xdigits);
187       if(++saw_xdigit > 4)
188         return (0);
189       continue;
190     }
191     if(ch == ':') {
192       curtok = src;
193       if(!saw_xdigit) {
194         if(colonp)
195           return (0);
196         colonp = tp;
197         continue;
198       }
199       if(tp + INT16SZ > endp)
200         return (0);
201       *tp++ = (unsigned char) ((val >> 8) & 0xff);
202       *tp++ = (unsigned char) (val & 0xff);
203       saw_xdigit = 0;
204       val = 0;
205       continue;
206     }
207     if(ch == '.' && ((tp + INADDRSZ) <= endp) &&
208         inet_pton4(curtok, tp) > 0) {
209       tp += INADDRSZ;
210       saw_xdigit = 0;
211       break;    /* '\0' was seen by inet_pton4(). */
212     }
213     return (0);
214   }
215   if(saw_xdigit) {
216     if(tp + INT16SZ > endp)
217       return (0);
218     *tp++ = (unsigned char) ((val >> 8) & 0xff);
219     *tp++ = (unsigned char) (val & 0xff);
220   }
221   if(colonp) {
222     /*
223      * Since some memmove()'s erroneously fail to handle
224      * overlapping regions, we will do the shift by hand.
225      */
226     const ssize_t n = tp - colonp;
227     ssize_t i;
228 
229     if(tp == endp)
230       return (0);
231     for(i = 1; i <= n; i++) {
232       *(endp - i) = *(colonp + n - i);
233       *(colonp + n - i) = 0;
234     }
235     tp = endp;
236   }
237   if(tp != endp)
238     return (0);
239   memcpy(dst, tmp, IN6ADDRSZ);
240   return (1);
241 }
242 
243 #endif /* HAVE_INET_PTON */
244