1 /* Copyright (C) 1993-2023 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 As a special exception, if you link the code in this file with
19 files compiled with a GNU compiler to produce an executable,
20 that does not cause the resulting executable to be covered by
21 the GNU Lesser General Public License. This exception does not
22 however invalidate any other reasons why the executable file
23 might be covered by the GNU Lesser General Public License.
24 This exception applies to code released by its copyright holders
25 in files containing the exception. */
26
27 #include <libioP.h>
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <shlib-compat.h>
31 #include <pointer_guard.h>
32
33 ssize_t
34 _IO_cookie_read (FILE *fp, void *buf, ssize_t size)
35 {
36 struct _IO_cookie_file *cfile = (struct _IO_cookie_file *) fp;
37 cookie_read_function_t *read_cb = cfile->__io_functions.read;
38 PTR_DEMANGLE (read_cb);
39
40 if (read_cb == NULL)
41 return -1;
42
43 return read_cb (cfile->__cookie, buf, size);
44 }
45
46 ssize_t
47 _IO_cookie_write (FILE *fp, const void *buf, ssize_t size)
48 {
49 struct _IO_cookie_file *cfile = (struct _IO_cookie_file *) fp;
50 cookie_write_function_t *write_cb = cfile->__io_functions.write;
51 PTR_DEMANGLE (write_cb);
52
53 if (write_cb == NULL)
54 {
55 fp->_flags |= _IO_ERR_SEEN;
56 return 0;
57 }
58
59 ssize_t n = write_cb (cfile->__cookie, buf, size);
60 if (n < size)
61 fp->_flags |= _IO_ERR_SEEN;
62
63 return n;
64 }
65
66 off64_t
67 _IO_cookie_seek (FILE *fp, off64_t offset, int dir)
68 {
69 struct _IO_cookie_file *cfile = (struct _IO_cookie_file *) fp;
70 cookie_seek_function_t *seek_cb = cfile->__io_functions.seek;
71 PTR_DEMANGLE (seek_cb);
72
73 return ((seek_cb == NULL
74 || (seek_cb (cfile->__cookie, &offset, dir)
75 == -1)
76 || offset == (off64_t) -1)
77 ? _IO_pos_BAD : offset);
78 }
79
80 int
81 _IO_cookie_close (FILE *fp)
82 {
83 struct _IO_cookie_file *cfile = (struct _IO_cookie_file *) fp;
84 cookie_close_function_t *close_cb = cfile->__io_functions.close;
85 PTR_DEMANGLE (close_cb);
86
87 if (close_cb == NULL)
88 return 0;
89
90 return close_cb (cfile->__cookie);
91 }
92
93
94 off64_t
95 _IO_cookie_seekoff (FILE *fp, off64_t offset, int dir, int mode)
96 {
97 /* We must force the fileops code to always use seek to determine
98 the position. */
99 fp->_offset = _IO_pos_BAD;
100 return _IO_file_seekoff (fp, offset, dir, mode);
101 }
102
103 /* Copy the callbacks from SOURCE to *TARGET, with pointer
104 mangling. */
105 static void
106 set_callbacks (cookie_io_functions_t *target,
107 cookie_io_functions_t source)
108 {
109 PTR_MANGLE (source.read);
110 PTR_MANGLE (source.write);
111 PTR_MANGLE (source.seek);
112 PTR_MANGLE (source.close);
113 *target = source;
114 }
115
116 void
117 _IO_cookie_init (struct _IO_cookie_file *cfile, int read_write,
118 void *cookie, cookie_io_functions_t io_functions)
119 {
120 _IO_init_internal (&cfile->__fp.file, 0);
121 _IO_JUMPS (&cfile->__fp) = &_IO_cookie_jumps;
122
123 cfile->__cookie = cookie;
124 set_callbacks (&cfile->__io_functions, io_functions);
125
126 _IO_new_file_init_internal (&cfile->__fp);
127
128 _IO_mask_flags (&cfile->__fp.file, read_write,
129 _IO_NO_READS+_IO_NO_WRITES+_IO_IS_APPENDING);
130
131 cfile->__fp.file._flags2 |= _IO_FLAGS2_NEED_LOCK;
132
133 /* We use a negative number different from -1 for _fileno to mark that
134 this special stream is not associated with a real file, but still has
135 to be treated as such. */
136 cfile->__fp.file._fileno = -2;
137 }
138
139
140 FILE *
141 _IO_fopencookie (void *cookie, const char *mode,
142 cookie_io_functions_t io_functions)
143 {
144 int read_write;
145 struct locked_FILE
146 {
147 struct _IO_cookie_file cfile;
148 #ifdef _IO_MTSAFE_IO
149 _IO_lock_t lock;
150 #endif
151 } *new_f;
152
153 switch (*mode++)
154 {
155 case 'r':
156 read_write = _IO_NO_WRITES;
157 break;
158 case 'w':
159 read_write = _IO_NO_READS;
160 break;
161 case 'a':
162 read_write = _IO_NO_READS|_IO_IS_APPENDING;
163 break;
164 default:
165 __set_errno (EINVAL);
166 return NULL;
167 }
168 if (mode[0] == '+' || (mode[0] == 'b' && mode[1] == '+'))
169 read_write &= _IO_IS_APPENDING;
170
171 new_f = (struct locked_FILE *) malloc (sizeof (struct locked_FILE));
172 if (new_f == NULL)
173 return NULL;
174 #ifdef _IO_MTSAFE_IO
175 new_f->cfile.__fp.file._lock = &new_f->lock;
176 #endif
177
178 _IO_cookie_init (&new_f->cfile, read_write, cookie, io_functions);
179
180 return (FILE *) &new_f->cfile.__fp;
181 }
182
183 versioned_symbol (libc, _IO_fopencookie, fopencookie, GLIBC_2_2);
184
185 #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2)
186
187 off64_t
188 attribute_compat_text_section
189 _IO_old_cookie_seek (FILE *fp, off64_t offset, int dir)
190 {
191 struct _IO_cookie_file *cfile = (struct _IO_cookie_file *) fp;
192 int (*seek_cb) (FILE *, off_t, int)
193 = (int (*) (FILE *, off_t, int)) cfile->__io_functions.seek;
194 PTR_DEMANGLE (seek_cb);
195
196 if (seek_cb == NULL)
197 return _IO_pos_BAD;
198
199 int ret = seek_cb (cfile->__cookie, offset, dir);
200
201 return (ret == -1) ? _IO_pos_BAD : ret;
202 }
203
204 FILE *
205 attribute_compat_text_section
206 _IO_old_fopencookie (void *cookie, const char *mode,
207 cookie_io_functions_t io_functions)
208 {
209 FILE *ret;
210
211 ret = _IO_fopencookie (cookie, mode, io_functions);
212 if (ret != NULL)
213 _IO_JUMPS_FILE_plus (ret) = &_IO_old_cookie_jumps;
214
215 return ret;
216 }
217
218 compat_symbol (libc, _IO_old_fopencookie, fopencookie, GLIBC_2_0);
219
220 #endif