xref: /dragonfly/contrib/tcpdump/strtoaddr.c (revision 2b7dbe20)
1 /*
2  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
3  * Copyright (c) 1996,1999 by 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 ISC DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
15  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 #ifdef HAVE_CONFIG_H
19 #include "config.h"
20 #endif
21 
22 #include <netdissect-stdinc.h>
23 #include <stddef.h>
24 #include <string.h>
25 
26 #include "strtoaddr.h"
27 
28 #ifndef NS_INADDRSZ
29 #define NS_INADDRSZ	4	/* IPv4 T_A */
30 #endif
31 
32 #ifndef NS_IN6ADDRSZ
33 #define NS_IN6ADDRSZ	16	/* IPv6 T_AAAA */
34 #endif
35 
36 #ifndef NS_INT16SZ
37 #define NS_INT16SZ	2	/* #/bytes of data in a uint16_t */
38 #endif
39 
40 /*%
41  * WARNING: Don't even consider trying to compile this on a system where
42  * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
43  */
44 
45 #ifndef NS_IN6ADDRSZ
46 #define NS_IN6ADDRSZ   16   /* IPv6 T_AAAA */
47 #endif
48 
49 /* int
50  * strtoaddr(src, dst)
51  *	convert presentation level IPv4 address to network order binary form.
52  * return:
53  *	1 if `src' is a valid input, else 0.
54  * notice:
55  *	does not touch `dst' unless it's returning 1.
56  * author:
57  *	Paul Vixie, 1996.
58  */
59 int
60 strtoaddr(const char *src, void *dst)
61 {
62 	uint32_t val;
63 	u_int digit;
64 	ptrdiff_t n;
65 	unsigned char c;
66 	u_int parts[4];
67 	u_int *pp = parts;
68 
69 	c = *src;
70 	for (;;) {
71 		/*
72 		 * Collect number up to ``.''.
73 		 * Values are specified as for C:
74 		 * 0x=hex, 0=octal, isdigit=decimal.
75 		 */
76 		if (!isdigit(c))
77 			return (0);
78 		val = 0;
79 		if (c == '0') {
80 			c = *++src;
81 			if (c == 'x' || c == 'X')
82 				return (0);
83 			else if (isdigit(c) && c != '9')
84 				return (0);
85 		}
86 		for (;;) {
87 			if (isdigit(c)) {
88 				digit = c - '0';
89 				if (digit >= 10)
90 					break;
91 				val = (val * 10) + digit;
92 				c = *++src;
93 			} else
94 				break;
95 		}
96 		if (c == '.') {
97 			/*
98 			 * Internet format:
99 			 *	a.b.c.d
100 			 *	a.b.c	(with c treated as 16 bits)
101 			 *	a.b	(with b treated as 24 bits)
102 			 *	a	(with a treated as 32 bits)
103 			 */
104 			if (pp >= parts + 3)
105 				return (0);
106 			*pp++ = val;
107 			c = *++src;
108 		} else
109 			break;
110 	}
111 	/*
112 	 * Check for trailing characters.
113 	 */
114 	if (c != '\0' && !isspace(c))
115 		return (0);
116 	/*
117 	 * Find the number of parts specified.
118 	 * It must be 4; we only support dotted quads, we don't
119 	 * support shorthand.
120 	 */
121 	n = pp - parts + 1;
122 	if (n != 4)
123 		return (0);
124 	/*
125 	 * parts[0-2] were set to the first 3 parts of the address;
126 	 * val was set to the 4th part.
127 	 *
128 	 * Check if any part is bigger than 255.
129 	 */
130 	if ((parts[0] | parts[1] | parts[2] | val) > 0xff)
131 		return (0);
132 	/*
133 	 * Add the other three parts to val.
134 	 */
135 	val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
136 	if (dst) {
137 		val = htonl(val);
138 		memcpy(dst, &val, NS_INADDRSZ);
139 	}
140 	return (1);
141 }
142 
143 /* int
144  * strtoaddr6(src, dst)
145  *	convert presentation level IPv6 address to network order binary form.
146  * return:
147  *	1 if `src' is a valid [RFC1884 2.2] address, else 0.
148  * notice:
149  *	(1) does not touch `dst' unless it's returning 1.
150  *	(2) :: in a full address is silently ignored.
151  * credit:
152  *	inspired by Mark Andrews.
153  * author:
154  *	Paul Vixie, 1996.
155  */
156 int
157 strtoaddr6(const char *src, void *dst)
158 {
159 	static const char xdigits_l[] = "0123456789abcdef",
160 			  xdigits_u[] = "0123456789ABCDEF";
161 	u_char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
162 	const char *xdigits, *curtok;
163 	int ch, seen_xdigits;
164 	u_int val;
165 
166 	memset((tp = tmp), '\0', NS_IN6ADDRSZ);
167 	endp = tp + NS_IN6ADDRSZ;
168 	colonp = NULL;
169 	/* Leading :: requires some special handling. */
170 	if (*src == ':')
171 		if (*++src != ':')
172 			return (0);
173 	curtok = src;
174 	seen_xdigits = 0;
175 	val = 0;
176 	while ((ch = *src++) != '\0') {
177 		const char *pch;
178 
179 		if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
180 			pch = strchr((xdigits = xdigits_u), ch);
181 		if (pch != NULL) {
182 			val <<= 4;
183 			val |= (int)(pch - xdigits);
184 			if (++seen_xdigits > 4)
185 				return (0);
186 			continue;
187 		}
188 		if (ch == ':') {
189 			curtok = src;
190 			if (!seen_xdigits) {
191 				if (colonp)
192 					return (0);
193 				colonp = tp;
194 				continue;
195 			} else if (*src == '\0')
196 				return (0);
197 			if (tp + NS_INT16SZ > endp)
198 				return (0);
199 			*tp++ = (u_char) (val >> 8) & 0xff;
200 			*tp++ = (u_char) val & 0xff;
201 			seen_xdigits = 0;
202 			val = 0;
203 			continue;
204 		}
205 		if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
206 		    strtoaddr(curtok, tp) > 0) {
207 			tp += NS_INADDRSZ;
208 			seen_xdigits = 0;
209 			break;	/*%< '\\0' was seen by strtoaddr(). */
210 		}
211 		return (0);
212 	}
213 	if (seen_xdigits) {
214 		if (tp + NS_INT16SZ > endp)
215 			return (0);
216 		*tp++ = (u_char) (val >> 8) & 0xff;
217 		*tp++ = (u_char) val & 0xff;
218 	}
219 	if (colonp != NULL) {
220 		/*
221 		 * Since some memmove()'s erroneously fail to handle
222 		 * overlapping regions, we'll do the shift by hand.
223 		 */
224 		const ptrdiff_t n = tp - colonp;
225 		int i;
226 
227 		if (tp == endp)
228 			return (0);
229 		for (i = 1; i <= n; i++) {
230 			endp[- i] = colonp[n - i];
231 			colonp[n - i] = 0;
232 		}
233 		tp = endp;
234 	}
235 	if (tp != endp)
236 		return (0);
237 	memcpy(dst, tmp, NS_IN6ADDRSZ);
238 	return (1);
239 }
240