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
33static 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
46static 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
66static 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
80static 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
94static 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
104static const struct _IO_jump_t _IO_cookie_jumps libio_vtable = {
105 JUMP_INIT_DUMMY,
106 JUMP_INIT(finish, _IO_file_finish),
107 JUMP_INIT(overflow, _IO_file_overflow),
108 JUMP_INIT(underflow, _IO_file_underflow),
109 JUMP_INIT(uflow, _IO_default_uflow),
110 JUMP_INIT(pbackfail, _IO_default_pbackfail),
111 JUMP_INIT(xsputn, _IO_file_xsputn),
112 JUMP_INIT(xsgetn, _IO_default_xsgetn),
113 JUMP_INIT(seekoff, _IO_cookie_seekoff),
114 JUMP_INIT(seekpos, _IO_default_seekpos),
115 JUMP_INIT(setbuf, _IO_file_setbuf),
116 JUMP_INIT(sync, _IO_file_sync),
117 JUMP_INIT(doallocate, _IO_file_doallocate),
118 JUMP_INIT(read, _IO_cookie_read),
119 JUMP_INIT(write, _IO_cookie_write),
120 JUMP_INIT(seek, _IO_cookie_seek),
121 JUMP_INIT(close, _IO_cookie_close),
122 JUMP_INIT(stat, _IO_default_stat),
123 JUMP_INIT(showmanyc, _IO_default_showmanyc),
124 JUMP_INIT(imbue, _IO_default_imbue),
125};
126
127
128/* Copy the callbacks from SOURCE to *TARGET, with pointer
129 mangling. */
130static void
131set_callbacks (cookie_io_functions_t *target,
132 cookie_io_functions_t source)
133{
134 PTR_MANGLE (source.read);
135 PTR_MANGLE (source.write);
136 PTR_MANGLE (source.seek);
137 PTR_MANGLE (source.close);
138 *target = source;
139}
140
141void
142_IO_cookie_init (struct _IO_cookie_file *cfile, int read_write,
143 void *cookie, cookie_io_functions_t io_functions)
144{
145 _IO_init_internal (&cfile->__fp.file, 0);
146 _IO_JUMPS (&cfile->__fp) = &_IO_cookie_jumps;
147
148 cfile->__cookie = cookie;
149 set_callbacks (&cfile->__io_functions, io_functions);
150
151 _IO_new_file_init_internal (&cfile->__fp);
152
153 _IO_mask_flags (&cfile->__fp.file, read_write,
154 _IO_NO_READS+_IO_NO_WRITES+_IO_IS_APPENDING);
155
156 cfile->__fp.file._flags2 |= _IO_FLAGS2_NEED_LOCK;
157
158 /* We use a negative number different from -1 for _fileno to mark that
159 this special stream is not associated with a real file, but still has
160 to be treated as such. */
161 cfile->__fp.file._fileno = -2;
162}
163
164
165FILE *
166_IO_fopencookie (void *cookie, const char *mode,
167 cookie_io_functions_t io_functions)
168{
169 int read_write;
170 struct locked_FILE
171 {
172 struct _IO_cookie_file cfile;
173#ifdef _IO_MTSAFE_IO
174 _IO_lock_t lock;
175#endif
176 } *new_f;
177
178 switch (*mode++)
179 {
180 case 'r':
181 read_write = _IO_NO_WRITES;
182 break;
183 case 'w':
184 read_write = _IO_NO_READS;
185 break;
186 case 'a':
187 read_write = _IO_NO_READS|_IO_IS_APPENDING;
188 break;
189 default:
190 __set_errno (EINVAL);
191 return NULL;
192 }
193 if (mode[0] == '+' || (mode[0] == 'b' && mode[1] == '+'))
194 read_write &= _IO_IS_APPENDING;
195
196 new_f = (struct locked_FILE *) malloc (sizeof (struct locked_FILE));
197 if (new_f == NULL)
198 return NULL;
199#ifdef _IO_MTSAFE_IO
200 new_f->cfile.__fp.file._lock = &new_f->lock;
201#endif
202
203 _IO_cookie_init (&new_f->cfile, read_write, cookie, io_functions);
204
205 return (FILE *) &new_f->cfile.__fp;
206}
207
208versioned_symbol (libc, _IO_fopencookie, fopencookie, GLIBC_2_2);
209
210#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2)
211
212static off64_t
213attribute_compat_text_section
214_IO_old_cookie_seek (FILE *fp, off64_t offset, int dir)
215{
216 struct _IO_cookie_file *cfile = (struct _IO_cookie_file *) fp;
217 int (*seek_cb) (FILE *, off_t, int)
218 = (int (*) (FILE *, off_t, int)) cfile->__io_functions.seek;
219 PTR_DEMANGLE (seek_cb);
220
221 if (seek_cb == NULL)
222 return _IO_pos_BAD;
223
224 int ret = seek_cb (cfile->__cookie, offset, dir);
225
226 return (ret == -1) ? _IO_pos_BAD : ret;
227}
228
229static const struct _IO_jump_t _IO_old_cookie_jumps libio_vtable = {
230 JUMP_INIT_DUMMY,
231 JUMP_INIT(finish, _IO_file_finish),
232 JUMP_INIT(overflow, _IO_file_overflow),
233 JUMP_INIT(underflow, _IO_file_underflow),
234 JUMP_INIT(uflow, _IO_default_uflow),
235 JUMP_INIT(pbackfail, _IO_default_pbackfail),
236 JUMP_INIT(xsputn, _IO_file_xsputn),
237 JUMP_INIT(xsgetn, _IO_default_xsgetn),
238 JUMP_INIT(seekoff, _IO_cookie_seekoff),
239 JUMP_INIT(seekpos, _IO_default_seekpos),
240 JUMP_INIT(setbuf, _IO_file_setbuf),
241 JUMP_INIT(sync, _IO_file_sync),
242 JUMP_INIT(doallocate, _IO_file_doallocate),
243 JUMP_INIT(read, _IO_cookie_read),
244 JUMP_INIT(write, _IO_cookie_write),
245 JUMP_INIT(seek, _IO_old_cookie_seek),
246 JUMP_INIT(close, _IO_cookie_close),
247 JUMP_INIT(stat, _IO_default_stat),
248 JUMP_INIT(showmanyc, _IO_default_showmanyc),
249 JUMP_INIT(imbue, _IO_default_imbue),
250};
251
252FILE *
253attribute_compat_text_section
254_IO_old_fopencookie (void *cookie, const char *mode,
255 cookie_io_functions_t io_functions)
256{
257 FILE *ret;
258
259 ret = _IO_fopencookie (cookie, mode, io_functions);
260 if (ret != NULL)
261 _IO_JUMPS_FILE_plus (ret) = &_IO_old_cookie_jumps;
262
263 return ret;
264}
265
266compat_symbol (libc, _IO_old_fopencookie, fopencookie, GLIBC_2_0);
267
268#endif
269