2 * Copyright (c) 1985, 1993
3 * The Regents of the University of California. All rights reserved.
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15 * This product includes software developed by the University of
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37 * Permission to use, copy, modify, and distribute this software for any
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57 * Permission to use, copy, modify, and distribute this software for any
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71 #if defined(LIBC_SCCS) && !defined(lint)
72 static const char sccsid[] = "@(#)res_comp.c 8.1 (Berkeley) 6/4/93";
73 static const char rcsid[] = "$Id: res_comp.c,v 1.2 2000/02/02 19:59:16 mellon Exp $";
74 #endif /* LIBC_SCCS and not lint */
76 #include <sys/types.h>
77 #include <sys/param.h>
78 #include <netinet/in.h>
83 #include <sys/socket.h>
85 #include "minires/minires.h"
86 #include "arpa/nameser.h"
89 * Expand compressed domain name 'comp_dn' to full domain name.
90 * 'msg' is a pointer to the begining of the message,
91 * 'eomorig' points to the first location after the message,
92 * 'exp_dn' is a pointer to a buffer of size 'length' for the result.
93 * Return size of compressed name or -1 if there was an error.
96 dn_expand(const u_char *msg, const u_char *eom, const u_char *src,
97 char *dst, unsigned dstsiz)
99 int n = ns_name_uncompress(msg, eom, src, dst, (size_t)dstsiz);
101 if (n > 0 && dst[0] == '.')
107 * Pack domain name 'exp_dn' in presentation form into 'comp_dn'.
108 * Return the size of the compressed name or -1.
109 * 'length' is the size of the array pointed to by 'comp_dn'.
112 dn_comp(const char *src, u_char *dst, unsigned dstsiz,
113 u_char **dnptrs, u_char **lastdnptr)
115 return (ns_name_compress(src, dst, (size_t)dstsiz,
116 (const u_char **)dnptrs,
117 (const u_char **)lastdnptr));
121 * Skip over a compressed domain name. Return the size or -1.
124 dn_skipname(const u_char *ptr, const u_char *eom) {
125 const u_char *saveptr = ptr;
127 if (ns_name_skip(&ptr, eom) == -1)
129 return (ptr - saveptr);
133 * Verify that a domain name uses an acceptable character set.
138 * Note the conspicuous absence of ctype macros in these definitions. On
139 * non-ASCII hosts, we can't depend on string literals or ctype macros to
140 * tell us anything about network-format data. The rest of the BIND system
141 * is not careful about this, but for some reason, we're doing it right here.
144 #define hyphenchar(c) ((c) == 0x2d)
145 #define bslashchar(c) ((c) == 0x5c)
146 #define periodchar(c) ((c) == PERIOD)
147 #define asterchar(c) ((c) == 0x2a)
148 #define alphachar(c) (((c) >= 0x41 && (c) <= 0x5a) \
149 || ((c) >= 0x61 && (c) <= 0x7a))
150 #define digitchar(c) ((c) >= 0x30 && (c) <= 0x39)
152 #define borderchar(c) (alphachar(c) || digitchar(c))
153 #define middlechar(c) (borderchar(c) || hyphenchar(c))
154 #define domainchar(c) ((c) > 0x20 && (c) < 0x7f)
157 res_hnok(const char *dn) {
158 int ppch = '\0', pch = PERIOD, ch = *dn++;
163 if (periodchar(ch)) {
165 } else if (periodchar(pch)) {
168 } else if (periodchar(nch) || nch == '\0') {
175 ppch = pch, pch = ch, ch = nch;
181 * hostname-like (A, MX, WKS) owners can have "*" as their first label
182 * but must otherwise be as a host name.
185 res_ownok(const char *dn) {
186 if (asterchar(dn[0])) {
187 if (periodchar(dn[1]))
188 return (res_hnok(dn+2));
192 return (res_hnok(dn));
196 * SOA RNAMEs and RP RNAMEs can have any printable character in their first
197 * label, but the rest of the name has to look like a host name.
200 res_mailok(const char *dn) {
203 /* "." is a valid missing representation */
207 /* otherwise <label>.<hostname> */
208 while ((ch = *dn++) != '\0') {
211 if (!escaped && periodchar(ch))
215 else if (bslashchar(ch))
219 return (res_hnok(dn));
224 * This function is quite liberal, since RFC 1034's character sets are only
228 res_dnok(const char *dn) {
231 while ((ch = *dn++) != '\0')