2 * Copyright (c) 1985, 1993
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29 * @(#)res_comp.c 8.1 (Berkeley) 6/4/93
30 * $From: Id: res_comp.c,v 8.11 1997/05/21 19:31:04 halley Exp $
31 * $FreeBSD: src/lib/libc/net/res_comp.c,v 1.16 1999/08/28 00:00:16 peter Exp $
32 * $DragonFly: src/lib/libc/net/res_comp.c,v 1.4 2005/11/13 02:04:47 swildner Exp $
36 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
38 * Permission to use, copy, modify, and distribute this software for any
39 * purpose with or without fee is hereby granted, provided that the above
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50 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
51 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
56 * Portions Copyright (c) 1996 by Internet Software Consortium.
58 * Permission to use, copy, modify, and distribute this software for any
59 * purpose with or without fee is hereby granted, provided that the above
60 * copyright notice and this permission notice appear in all copies.
62 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
63 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
64 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
65 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
66 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
67 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
68 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
72 #include <sys/types.h>
73 #include <sys/param.h>
74 #include <netinet/in.h>
75 #include <arpa/nameser.h>
85 * Expand compressed domain name 'comp_dn' to full domain name.
86 * 'msg' is a pointer to the begining of the message,
87 * 'eomorig' points to the first location after the message,
88 * 'exp_dn' is a pointer to a buffer of size 'length' for the result.
89 * Return size of compressed name or -1 if there was an error.
92 dn_expand(const u_char *msg, const u_char *eom, const u_char *src,
93 char *dst, int dstsiz)
95 int n = ns_name_uncompress(msg, eom, src, dst, (size_t)dstsiz);
97 if (n > 0 && dst[0] == '.')
103 * Pack domain name 'exp_dn' in presentation form into 'comp_dn'.
104 * Return the size of the compressed name or -1.
105 * 'length' is the size of the array pointed to by 'comp_dn'.
108 dn_comp(const char *src, u_char *dst, int dstsiz,
109 u_char **dnptrs, u_char **lastdnptr)
111 return (ns_name_compress(src, dst, (size_t)dstsiz,
112 (const u_char **)dnptrs,
113 (const u_char **)lastdnptr));
117 * Skip over a compressed domain name. Return the size or -1.
120 dn_skipname(const u_char *ptr, const u_char *eom)
122 const u_char *saveptr = ptr;
124 if (ns_name_skip(&ptr, eom) == -1)
126 return (ptr - saveptr);
130 * Verify that a domain name uses an acceptable character set.
134 * Note the conspicuous absence of ctype macros in these definitions. On
135 * non-ASCII hosts, we can't depend on string literals or ctype macros to
136 * tell us anything about network-format data. The rest of the BIND system
137 * is not careful about this, but for some reason, we're doing it right here.
140 #define hyphenchar(c) ((c) == 0x2d)
141 #define bslashchar(c) ((c) == 0x5c)
142 #define periodchar(c) ((c) == PERIOD)
143 #define asterchar(c) ((c) == 0x2a)
144 #define alphachar(c) (((c) >= 0x41 && (c) <= 0x5a) \
145 || ((c) >= 0x61 && (c) <= 0x7a))
146 #define digitchar(c) ((c) >= 0x30 && (c) <= 0x39)
148 #define borderchar(c) (alphachar(c) || digitchar(c))
149 #define middlechar(c) (borderchar(c) || hyphenchar(c))
150 #define domainchar(c) ((c) > 0x20 && (c) < 0x7f)
153 res_hnok(const char *dn)
155 int ppch = '\0', pch = PERIOD, ch = *dn++;
160 if (periodchar(ch)) {
162 } else if (periodchar(pch)) {
165 } else if (periodchar(nch) || nch == '\0') {
172 ppch = pch, pch = ch, ch = nch;
178 * hostname-like (A, MX, WKS) owners can have "*" as their first label
179 * but must otherwise be as a host name.
182 res_ownok(const char *dn)
184 if (asterchar(dn[0])) {
185 if (periodchar(dn[1]))
186 return (res_hnok(dn+2));
190 return (res_hnok(dn));
194 * SOA RNAMEs and RP RNAMEs can have any printable character in their first
195 * label, but the rest of the name has to look like a host name.
198 res_mailok(const char *dn)
202 /* "." is a valid missing representation */
206 /* otherwise <label>.<hostname> */
207 while ((ch = *dn++) != '\0') {
210 if (!escaped && periodchar(ch))
214 else if (bslashchar(ch))
218 return (res_hnok(dn));
223 * This function is quite liberal, since RFC 1034's character sets are only
227 res_dnok(const char *dn)
231 while ((ch = *dn++) != '\0')
239 * This module must export the following externally-visible symbols:
244 * Note that one _ comes from C and the others come from us.
246 void __putlong(u_int32_t src, u_char *dst) { ns_put32(src, dst); }
247 void __putshort(u_int16_t src, u_char *dst) { ns_put16(src, dst); }
248 u_int32_t _getlong(const u_char *src) { return (ns_get32(src)); }
249 u_int16_t _getshort(const u_char *src) { return (ns_get16(src)); }
250 #endif /*BIND_4_COMPAT*/
253 * Weak aliases for applications that use certain private entry points,
254 * and fail to include <resolv.h>.
257 __weak_reference(__dn_comp, dn_comp);
259 __weak_reference(__dn_expand, dn_expand);