1/* Copyright (C) 1996-2023 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18#include <assert.h>
19#include <dlfcn.h>
20#include <errno.h>
21#include <gconv.h>
22#include <wchar.h>
23#include <wcsmbsload.h>
24
25#include <pointer_guard.h>
26
27#ifndef EILSEQ
28# define EILSEQ EINVAL
29#endif
30
31
32/* This is the private state used if PS is NULL. */
33static mbstate_t state;
34
35/* This is a non-standard function but it is very useful in the
36 implementation of stdio because we have to deal with unterminated
37 buffers. At most NWC wide character will be converted. */
38size_t
39__wcsnrtombs (char *dst, const wchar_t **src, size_t nwc, size_t len,
40 mbstate_t *ps)
41{
42 struct __gconv_step_data data;
43 const wchar_t *srcend;
44 int status;
45 size_t result;
46 struct __gconv_step *tomb;
47 const struct gconv_fcts *fcts;
48
49 /* Tell where we want the result. */
50 data.__invocation_counter = 0;
51 data.__internal_use = 1;
52 data.__flags = __GCONV_IS_LAST;
53 data.__statep = ps ?: &state;
54
55 if (nwc == 0)
56 return 0;
57 srcend = *src + __wcsnlen (*src, nwc - 1) + 1;
58
59 /* Get the conversion functions. */
60 fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
61
62 /* Get the structure with the function pointers. */
63 tomb = fcts->tomb;
64 __gconv_fct fct = tomb->__fct;
65 if (tomb->__shlib_handle != NULL)
66 PTR_DEMANGLE (fct);
67
68 /* We have to handle DST == NULL special. */
69 if (dst == NULL)
70 {
71 mbstate_t temp_state;
72 unsigned char buf[256]; /* Just an arbitrary value. */
73 const unsigned char *inbuf = (const unsigned char *) *src;
74 size_t dummy;
75
76 temp_state = *data.__statep;
77 data.__statep = &temp_state;
78
79 result = 0;
80 data.__outbufend = buf + sizeof (buf);
81
82 do
83 {
84 data.__outbuf = buf;
85
86 status = DL_CALL_FCT (fct, (tomb, &data, &inbuf,
87 (const unsigned char *) srcend, NULL,
88 &dummy, 0, 1));
89
90 /* Count the number of bytes. */
91 result += data.__outbuf - buf;
92 }
93 while (status == __GCONV_FULL_OUTPUT);
94
95 if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
96 && data.__outbuf[-1] == '\0')
97 /* Don't count the NUL character in. */
98 --result;
99 }
100 else
101 {
102 /* This code is based on the safe assumption that all internal
103 multi-byte encodings use the NUL byte only to mark the end
104 of the string. */
105 size_t dummy;
106
107 data.__outbuf = (unsigned char *) dst;
108 data.__outbufend = (unsigned char *) dst + len;
109
110 status = DL_CALL_FCT (fct, (tomb, &data, (const unsigned char **) src,
111 (const unsigned char *) srcend, NULL,
112 &dummy, 0, 1));
113
114 /* Count the number of bytes. */
115 result = data.__outbuf - (unsigned char *) dst;
116
117 /* We have to determine whether the last character converted
118 is the NUL character. */
119 if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
120 && data.__outbuf[-1] == '\0')
121 {
122 assert (data.__outbuf != (unsigned char *) dst);
123 assert (__mbsinit (data.__statep));
124 *src = NULL;
125 --result;
126 }
127 }
128
129 /* There must not be any problems with the conversion but illegal input
130 characters. */
131 assert (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
132 || status == __GCONV_ILLEGAL_INPUT
133 || status == __GCONV_INCOMPLETE_INPUT
134 || status == __GCONV_FULL_OUTPUT);
135
136 if (status != __GCONV_OK && status != __GCONV_FULL_OUTPUT
137 && status != __GCONV_EMPTY_INPUT)
138 {
139 result = (size_t) -1;
140 __set_errno (EILSEQ);
141 }
142
143 return result;
144}
145weak_alias (__wcsnrtombs, wcsnrtombs)
146