xref: /netbsd-src/external/bsd/tcpdump/dist/strtoaddr.c (revision 4439cfd0acf9c7dc90625e5cd83b2317a9ab8967)
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 #include <sys/cdefs.h>
19 #ifndef lint
20 __RCSID("$NetBSD: strtoaddr.c,v 1.5 2024/09/02 16:15:33 christos Exp $");
21 #endif
22 
23 #include <config.h>
24 
25 #include "netdissect-stdinc.h"
26 #include <stddef.h>
27 #include <string.h>
28 
29 #include "netdissect-ctype.h"
30 
31 #include "strtoaddr.h"
32 
33 #ifndef NS_INADDRSZ
34 #define NS_INADDRSZ	4	/* IPv4 T_A */
35 #endif
36 
37 #ifndef NS_IN6ADDRSZ
38 #define NS_IN6ADDRSZ	16	/* IPv6 T_AAAA */
39 #endif
40 
41 #ifndef NS_INT16SZ
42 #define NS_INT16SZ	2	/* #/bytes of data in a uint16_t */
43 #endif
44 
45 /*%
46  * WARNING: Don't even consider trying to compile this on a system where
47  * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
48  */
49 
50 /* int
51  * strtoaddr(src, dst)
52  *	convert presentation level IPv4 address to network order binary form.
53  * return:
54  *	1 if `src' is a valid input, else 0.
55  * notice:
56  *	does not touch `dst' unless it's returning 1.
57  * author:
58  *	Paul Vixie, 1996.
59  */
60 int
61 strtoaddr(const char *src, void *dst)
62 {
63 	uint32_t val;
64 	u_int digit;
65 	ptrdiff_t n;
66 	unsigned char c;
67 	u_int parts[4];
68 	u_int *pp = parts;
69 
70 	c = *src;
71 	for (;;) {
72 		/*
73 		 * Collect number up to ``.''.
74 		 * Values are specified as for C:
75 		 * 0x=hex, 0=octal, isdigit=decimal.
76 		 */
77 		if (!ND_ASCII_ISDIGIT(c))
78 			return (0);
79 		val = 0;
80 		if (c == '0') {
81 			c = *++src;
82 			if (c == 'x' || c == 'X')
83 				return (0);
84 			else if (ND_ASCII_ISDIGIT(c) && c != '9')
85 				return (0);
86 		}
87 		for (;;) {
88 			if (ND_ASCII_ISDIGIT(c)) {
89 				digit = c - '0';
90 				val = (val * 10) + digit;
91 				c = *++src;
92 			} else
93 				break;
94 		}
95 		if (c == '.') {
96 			/*
97 			 * Internet format:
98 			 *	a.b.c.d
99 			 *	a.b.c	(with c treated as 16 bits)
100 			 *	a.b	(with b treated as 24 bits)
101 			 *	a	(with a treated as 32 bits)
102 			 */
103 			if (pp >= parts + 3)
104 				return (0);
105 			*pp++ = val;
106 			c = *++src;
107 		} else
108 			break;
109 	}
110 	/*
111 	 * Check for trailing characters.
112 	 */
113 	if (c != '\0' && c != ' ' && c != '\t')
114 		return (0);
115 	/*
116 	 * Find the number of parts specified.
117 	 * It must be 4; we only support dotted quads, we don't
118 	 * support shorthand.
119 	 */
120 	n = pp - parts + 1;
121 	if (n != 4)
122 		return (0);
123 	/*
124 	 * parts[0-2] were set to the first 3 parts of the address;
125 	 * val was set to the 4th part.
126 	 *
127 	 * Check if any part is bigger than 255.
128 	 */
129 	if ((parts[0] | parts[1] | parts[2] | val) > 0xff)
130 		return (0);
131 	/*
132 	 * Add the other three parts to val.
133 	 */
134 	val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
135 	if (dst) {
136 		val = htonl(val);
137 		memcpy(dst, &val, NS_INADDRSZ);
138 	}
139 	return (1);
140 }
141 
142 /* int
143  * strtoaddr6(src, dst)
144  *	convert presentation level IPv6 address to network order binary form.
145  * return:
146  *	1 if `src' is a valid [RFC1884 2.2] address, else 0.
147  * notice:
148  *	(1) does not touch `dst' unless it's returning 1.
149  *	(2) :: in a full address is silently ignored.
150  * credit:
151  *	inspired by Mark Andrews.
152  * author:
153  *	Paul Vixie, 1996.
154  */
155 int
156 strtoaddr6(const char *src, void *dst)
157 {
158 	static const char xdigits_l[] = "0123456789abcdef",
159 			  xdigits_u[] = "0123456789ABCDEF";
160 	u_char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
161 	const char *xdigits, *curtok;
162 	int ch, seen_xdigits;
163 	u_int val;
164 
165 	memset((tp = tmp), '\0', NS_IN6ADDRSZ);
166 	endp = tp + NS_IN6ADDRSZ;
167 	colonp = NULL;
168 	/* Leading :: requires some special handling. */
169 	if (*src == ':')
170 		if (*++src != ':')
171 			return (0);
172 	curtok = src;
173 	seen_xdigits = 0;
174 	val = 0;
175 	while ((ch = *src++) != '\0') {
176 		const char *pch;
177 
178 		if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
179 			pch = strchr((xdigits = xdigits_u), ch);
180 		if (pch != NULL) {
181 			val <<= 4;
182 			val |= (int)(pch - xdigits);
183 			if (++seen_xdigits > 4)
184 				return (0);
185 			continue;
186 		}
187 		if (ch == ':') {
188 			curtok = src;
189 			if (!seen_xdigits) {
190 				if (colonp)
191 					return (0);
192 				colonp = tp;
193 				continue;
194 			} else if (*src == '\0')
195 				return (0);
196 			if (tp + NS_INT16SZ > endp)
197 				return (0);
198 			*tp++ = (u_char) (val >> 8) & 0xff;
199 			*tp++ = (u_char) val & 0xff;
200 			seen_xdigits = 0;
201 			val = 0;
202 			continue;
203 		}
204 		if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
205 		    strtoaddr(curtok, tp) > 0) {
206 			tp += NS_INADDRSZ;
207 			seen_xdigits = 0;
208 			break;	/*%< '\\0' was seen by strtoaddr(). */
209 		}
210 		return (0);
211 	}
212 	if (seen_xdigits) {
213 		if (tp + NS_INT16SZ > endp)
214 			return (0);
215 		*tp++ = (u_char) (val >> 8) & 0xff;
216 		*tp++ = (u_char) val & 0xff;
217 	}
218 	if (colonp != NULL) {
219 		/*
220 		 * Since some memmove()'s erroneously fail to handle
221 		 * overlapping regions, we'll do the shift by hand.
222 		 */
223 		const ptrdiff_t n = tp - colonp;
224 		int i;
225 
226 		if (tp == endp)
227 			return (0);
228 		for (i = 1; i <= n; i++) {
229 			endp[- i] = colonp[n - i];
230 			colonp[n - i] = 0;
231 		}
232 		tp = endp;
233 	}
234 	if (tp != endp)
235 		return (0);
236 	memcpy(dst, tmp, NS_IN6ADDRSZ);
237 	return (1);
238 }
239