1 /* inet_pton.c -- convert IPv4 and IPv6 addresses from text to binary form
2 
3    Copyright (C) 2006, 2008-2021 Free Software Foundation, Inc.
4 
5    This program is free software: you can redistribute it and/or modify
6    it under the terms of the GNU Lesser General Public License as published by
7    the Free Software Foundation; either version 3 of the License, or
8    (at your option) any later version.
9 
10    This program is distributed in the hope that it will be useful,
11    but WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13    GNU Lesser General Public License for more details.
14 
15    You should have received a copy of the GNU Lesser General Public License
16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
17 
18 /*
19  * Copyright (c) 1996,1999 by Internet Software Consortium.
20  *
21  * Permission to use, copy, modify, and distribute this software for any
22  * purpose with or without fee is hereby granted, provided that the above
23  * copyright notice and this permission notice appear in all copies.
24  *
25  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
26  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
27  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
28  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
29  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
30  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
31  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
32  * SOFTWARE.
33  */
34 
35 #include <config.h>
36 
37 /* Specification.  */
38 #include <arpa/inet.h>
39 
40 #if HAVE_DECL_INET_PTON
41 
42 # undef inet_pton
43 
44 int
rpl_inet_pton(int af,const char * restrict src,void * restrict dst)45 rpl_inet_pton (int af, const char *restrict src, void *restrict dst)
46 {
47   return inet_pton (af, src, dst);
48 }
49 
50 #else
51 
52 # include <c-ctype.h>
53 # include <string.h>
54 # include <errno.h>
55 
56 # define NS_INADDRSZ 4
57 # define NS_IN6ADDRSZ 16
58 # define NS_INT16SZ 2
59 
60 /*
61  * WARNING: Don't even consider trying to compile this on a system where
62  * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
63  */
64 
65 static int inet_pton4 (const char *src, unsigned char *dst);
66 # if HAVE_IPV6
67 static int inet_pton6 (const char *src, unsigned char *dst);
68 # endif
69 
70 /* int
71  * inet_pton(af, src, dst)
72  *      convert from presentation format (which usually means ASCII printable)
73  *      to network format (which is usually some kind of binary format).
74  * return:
75  *      1 if the address was valid for the specified address family
76  *      0 if the address wasn't valid ('dst' is untouched in this case)
77  *      -1 if some other error occurred ('dst' is untouched in this case, too)
78  * author:
79  *      Paul Vixie, 1996.
80  */
81 int
inet_pton(int af,const char * restrict src,void * restrict dst)82 inet_pton (int af, const char *restrict src, void *restrict dst)
83 {
84   switch (af)
85     {
86     case AF_INET:
87       return (inet_pton4 (src, dst));
88 
89 # if HAVE_IPV6
90     case AF_INET6:
91       return (inet_pton6 (src, dst));
92 # endif
93 
94     default:
95       errno = EAFNOSUPPORT;
96       return (-1);
97     }
98   /* NOTREACHED */
99 }
100 
101 /* int
102  * inet_pton4(src, dst)
103  *      like inet_aton() but without all the hexadecimal, octal (with the
104  *      exception of 0) and shorthand.
105  * return:
106  *      1 if 'src' is a valid dotted quad, else 0.
107  * notice:
108  *      does not touch 'dst' unless it's returning 1.
109  * author:
110  *      Paul Vixie, 1996.
111  */
112 static int
inet_pton4(const char * restrict src,unsigned char * restrict dst)113 inet_pton4 (const char *restrict src, unsigned char *restrict dst)
114 {
115   int saw_digit, octets, ch;
116   unsigned char tmp[NS_INADDRSZ], *tp;
117 
118   saw_digit = 0;
119   octets = 0;
120   *(tp = tmp) = 0;
121   while ((ch = *src++) != '\0')
122     {
123 
124       if (ch >= '0' && ch <= '9')
125         {
126           unsigned new = *tp * 10 + (ch - '0');
127 
128           if (saw_digit && *tp == 0)
129             return (0);
130           if (new > 255)
131             return (0);
132           *tp = new;
133           if (!saw_digit)
134             {
135               if (++octets > 4)
136                 return (0);
137               saw_digit = 1;
138             }
139         }
140       else if (ch == '.' && saw_digit)
141         {
142           if (octets == 4)
143             return (0);
144           *++tp = 0;
145           saw_digit = 0;
146         }
147       else
148         return (0);
149     }
150   if (octets < 4)
151     return (0);
152   memcpy (dst, tmp, NS_INADDRSZ);
153   return (1);
154 }
155 
156 # if HAVE_IPV6
157 
158 /* int
159  * inet_pton6(src, dst)
160  *      convert presentation level address to network order binary form.
161  * return:
162  *      1 if 'src' is a valid [RFC1884 2.2] address, else 0.
163  * notice:
164  *      (1) does not touch 'dst' unless it's returning 1.
165  *      (2) :: in a full address is silently ignored.
166  * credit:
167  *      inspired by Mark Andrews.
168  * author:
169  *      Paul Vixie, 1996.
170  */
171 static int
inet_pton6(const char * restrict src,unsigned char * restrict dst)172 inet_pton6 (const char *restrict src, unsigned char *restrict dst)
173 {
174   static const char xdigits[] = "0123456789abcdef";
175   unsigned char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
176   const char *curtok;
177   int ch, saw_xdigit;
178   unsigned val;
179 
180   tp = memset (tmp, '\0', NS_IN6ADDRSZ);
181   endp = tp + NS_IN6ADDRSZ;
182   colonp = NULL;
183   /* Leading :: requires some special handling. */
184   if (*src == ':')
185     if (*++src != ':')
186       return (0);
187   curtok = src;
188   saw_xdigit = 0;
189   val = 0;
190   while ((ch = c_tolower (*src++)) != '\0')
191     {
192       const char *pch;
193 
194       pch = strchr (xdigits, ch);
195       if (pch != NULL)
196         {
197           val <<= 4;
198           val |= (pch - xdigits);
199           if (val > 0xffff)
200             return (0);
201           saw_xdigit = 1;
202           continue;
203         }
204       if (ch == ':')
205         {
206           curtok = src;
207           if (!saw_xdigit)
208             {
209               if (colonp)
210                 return (0);
211               colonp = tp;
212               continue;
213             }
214           else if (*src == '\0')
215             {
216               return (0);
217             }
218           if (tp + NS_INT16SZ > endp)
219             return (0);
220           *tp++ = (u_char) (val >> 8) & 0xff;
221           *tp++ = (u_char) val & 0xff;
222           saw_xdigit = 0;
223           val = 0;
224           continue;
225         }
226       if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
227           inet_pton4 (curtok, tp) > 0)
228         {
229           tp += NS_INADDRSZ;
230           saw_xdigit = 0;
231           break;                /* '\0' was seen by inet_pton4(). */
232         }
233       return (0);
234     }
235   if (saw_xdigit)
236     {
237       if (tp + NS_INT16SZ > endp)
238         return (0);
239       *tp++ = (u_char) (val >> 8) & 0xff;
240       *tp++ = (u_char) val & 0xff;
241     }
242   if (colonp != NULL)
243     {
244       /*
245        * Since some memmove()'s erroneously fail to handle
246        * overlapping regions, we'll do the shift by hand.
247        */
248       const int n = tp - colonp;
249       int i;
250 
251       if (tp == endp)
252         return (0);
253       for (i = 1; i <= n; i++)
254         {
255           endp[-i] = colonp[n - i];
256           colonp[n - i] = 0;
257         }
258       tp = endp;
259     }
260   if (tp != endp)
261     return (0);
262   memcpy (dst, tmp, NS_IN6ADDRSZ);
263   return (1);
264 }
265 
266 # endif
267 
268 #endif
269