1/* Convert a DNS domain name from presentation to wire format.
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 <arpa/nameser.h>
19#include <errno.h>
20#include <shlib-compat.h>
21
22/* Converts an ASCII string into an encoded domain name as per
23 RFC1035. Returns -1 if it fails, 1 if string was fully qualified,
24 0 is string was not fully qualified. Enforces label and domain
25 length limits. */
26int
27___ns_name_pton (const char *src, unsigned char *dst, size_t dstsiz)
28{
29 unsigned char *label, *bp, *eom;
30 int c, n, escaped;
31
32 escaped = 0;
33 bp = dst;
34 eom = dst + dstsiz;
35 label = bp++;
36
37 while ((c = *src++) != 0)
38 {
39 if (escaped)
40 {
41 if ('0' <= c && c <= '9')
42 {
43 n = (c - '0') * 100;
44 if ((c = *src++) == 0 || c < '0' || c > '9')
45 {
46 __set_errno (EMSGSIZE);
47 return -1;
48 }
49 n += (c - '0') * 10;
50 if ((c = *src++) == 0 || c < '0' || c > '9')
51 {
52 __set_errno (EMSGSIZE);
53 return -1;
54 }
55 n += c - '0';
56 if (n > 255)
57 {
58 __set_errno (EMSGSIZE);
59 return -1;
60 }
61 c = n;
62 }
63 escaped = 0;
64 }
65 else if (c == '\\')
66 {
67 escaped = 1;
68 continue;
69 }
70 else if (c == '.')
71 {
72 c = (bp - label - 1);
73 if ((c & NS_CMPRSFLGS) != 0) /* Label too big. */
74 {
75 __set_errno (EMSGSIZE);
76 return -1;
77 }
78 if (label >= eom)
79 {
80 __set_errno (EMSGSIZE);
81 return -1;
82 }
83 *label = c;
84 /* Fully qualified ? */
85 if (*src == '\0')
86 {
87 if (c != 0)
88 {
89 if (bp >= eom)
90 {
91 __set_errno (EMSGSIZE);
92 return -1;
93 }
94 *bp++ = '\0';
95 }
96 if ((bp - dst) > MAXCDNAME)
97 {
98 __set_errno (EMSGSIZE);
99 return -1;
100 }
101 return 1;
102 }
103 if (c == 0 || *src == '.')
104 {
105 __set_errno (EMSGSIZE);
106 return -1;
107 }
108 label = bp++;
109 continue;
110 }
111 if (bp >= eom)
112 {
113 __set_errno (EMSGSIZE);
114 return -1;
115 }
116 *bp++ = (unsigned char) c;
117 }
118 if (escaped) /* Trailing backslash. */
119 {
120 __set_errno (EMSGSIZE);
121 return -1;
122 }
123 c = (bp - label - 1);
124 if ((c & NS_CMPRSFLGS) != 0) /* Label too big. */
125 {
126 __set_errno (EMSGSIZE);
127 return -1;
128 }
129 if (label >= eom)
130 {
131 __set_errno (EMSGSIZE);
132 return -1;
133 }
134 *label = c;
135 if (c != 0)
136 {
137 if (bp >= eom)
138 {
139 __set_errno (EMSGSIZE);
140 return -1;
141 }
142 *bp++ = 0;
143 }
144 if ((bp - dst) > MAXCDNAME) /* src too big. */
145 {
146 __set_errno (EMSGSIZE);
147 return -1;
148 }
149 return 0;
150}
151versioned_symbol (libc, ___ns_name_pton, ns_name_pton, GLIBC_2_34);
152versioned_symbol (libc, ___ns_name_pton, __ns_name_pton, GLIBC_PRIVATE);
153libc_hidden_ver (___ns_name_pton, __ns_name_pton)
154
155#if OTHER_SHLIB_COMPAT (libresolv, GLIBC_2_9, GLIBC_2_34)
156compat_symbol (libresolv, ___ns_name_pton, ns_name_pton, GLIBC_2_9);
157#endif
158

source code of glibc/resolv/ns_name_pton.c