1/* Classify a domain name for IDNA purposes.
2 Copyright (C) 2018-2023 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <errno.h>
20#include <inet/net-internal.h>
21#include <stdbool.h>
22#include <string.h>
23#include <wchar.h>
24
25enum idna_name_classification
26__idna_name_classify (const char *name)
27{
28 mbstate_t mbs;
29 memset (&mbs, 0, sizeof (mbs));
30 const char *p = name;
31 const char *end = p + strlen (p) + 1;
32 bool nonascii = false;
33 bool backslash = false;
34 while (true)
35 {
36 wchar_t wc;
37 size_t result = mbrtowc (&wc, p, end - p, &mbs);
38 if (result == 0)
39 /* NUL terminator was reached. */
40 break;
41 else if (result == (size_t) -2)
42 /* Incomplete trailing multi-byte character. This is an
43 encoding error because we received the full name. */
44 return idna_name_encoding_error;
45 else if (result == (size_t) -1)
46 {
47 /* Other error, including EILSEQ. */
48 if (errno == EILSEQ)
49 return idna_name_encoding_error;
50 else if (errno == ENOMEM)
51 return idna_name_memory_error;
52 else
53 return idna_name_error;
54 }
55 else
56 {
57 /* A wide character was decoded. */
58 p += result;
59 if (wc == L'\\')
60 backslash = true;
61 else if (wc > 127)
62 nonascii = true;
63 }
64 }
65
66 if (nonascii)
67 {
68 if (backslash)
69 return idna_name_nonascii_backslash;
70 else
71 return idna_name_nonascii;
72 }
73 else
74 return idna_name_ascii;
75}
76