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file_open.c
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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg 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  * FFmpeg 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 FFmpeg; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 #include "config.h"
20 #include "internal.h"
21 #include "mem.h"
22 #include <stdarg.h>
23 #include <fcntl.h>
24 #include <sys/stat.h>
25 #if HAVE_UNISTD_H
26 #include <unistd.h>
27 #endif
28 #if HAVE_IO_H
29 #include <io.h>
30 #endif
31 
32 #if defined(_WIN32) && !defined(__MINGW32CE__)
33 #undef open
34 #undef lseek
35 #undef stat
36 #undef fstat
37 #include <windows.h>
38 #include <share.h>
39 #include <errno.h>
40 #include "wchar_filename.h"
41 
42 static int win32_open(const char *filename_utf8, int oflag, int pmode)
43 {
44  int fd;
45  wchar_t *filename_w;
46 
47  /* convert UTF-8 to wide chars */
48  if (utf8towchar(filename_utf8, &filename_w))
49  return -1;
50  if (!filename_w)
51  goto fallback;
52 
53  fd = _wsopen(filename_w, oflag, SH_DENYNO, pmode);
54  av_freep(&filename_w);
55 
56  if (fd != -1 || (oflag & O_CREAT))
57  return fd;
58 
59 fallback:
60  /* filename may be in CP_ACP */
61  return _sopen(filename_utf8, oflag, SH_DENYNO, pmode);
62 }
63 #define open win32_open
64 #endif
65 
66 int avpriv_open(const char *filename, int flags, ...)
67 {
68  int fd;
69  unsigned int mode = 0;
70  va_list ap;
71 
72  va_start(ap, flags);
73  if (flags & O_CREAT)
74  mode = va_arg(ap, unsigned int);
75  va_end(ap);
76 
77 #ifdef O_CLOEXEC
78  flags |= O_CLOEXEC;
79 #endif
80 #ifdef O_NOINHERIT
81  flags |= O_NOINHERIT;
82 #endif
83 
84  fd = open(filename, flags, mode);
85 #if HAVE_FCNTL
86  if (fd != -1) {
87  if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)
88  av_log(NULL, AV_LOG_DEBUG, "Failed to set close on exec\n");
89  }
90 #endif
91 
92  return fd;
93 }
94 
95 typedef struct FileLogContext {
96  const AVClass *class;
97  int log_offset;
98  void *log_ctx;
100 
101 static const AVClass file_log_ctx_class = {
103  offsetof(FileLogContext, log_offset), offsetof(FileLogContext, log_ctx)
104 };
105 
106 int avpriv_tempfile(const char *prefix, char **filename, int log_offset, void *log_ctx)
107 {
108  FileLogContext file_log_ctx = { &file_log_ctx_class, log_offset, log_ctx };
109  int fd = -1;
110 #if !HAVE_MKSTEMP
111  void *ptr= tempnam(NULL, prefix);
112  if(!ptr)
113  ptr= tempnam(".", prefix);
114  *filename = av_strdup(ptr);
115 #undef free
116  free(ptr);
117 #else
118  size_t len = strlen(prefix) + 12; /* room for "/tmp/" and "XXXXXX\0" */
119  *filename = av_malloc(len);
120 #endif
121  /* -----common section-----*/
122  if (!*filename) {
123  av_log(&file_log_ctx, AV_LOG_ERROR, "ff_tempfile: Cannot allocate file name\n");
124  return AVERROR(ENOMEM);
125  }
126 #if !HAVE_MKSTEMP
127 # ifndef O_BINARY
128 # define O_BINARY 0
129 # endif
130 # ifndef O_EXCL
131 # define O_EXCL 0
132 # endif
133  fd = open(*filename, O_RDWR | O_BINARY | O_CREAT | O_EXCL, 0600);
134 #else
135  snprintf(*filename, len, "/tmp/%sXXXXXX", prefix);
136  fd = mkstemp(*filename);
137 #if defined(_WIN32) || defined (__ANDROID__)
138  if (fd < 0) {
139  snprintf(*filename, len, "./%sXXXXXX", prefix);
140  fd = mkstemp(*filename);
141  }
142 #endif
143 #endif
144  /* -----common section-----*/
145  if (fd < 0) {
146  int err = AVERROR(errno);
147  av_log(&file_log_ctx, AV_LOG_ERROR, "ff_tempfile: Cannot open temporary file %s\n", *filename);
148  av_freep(filename);
149  return err;
150  }
151  return fd; /* success */
152 }
153 
154 FILE *av_fopen_utf8(const char *path, const char *mode)
155 {
156  int fd;
157  int access;
158  const char *m = mode;
159 
160  switch (*m++) {
161  case 'r': access = O_RDONLY; break;
162  case 'w': access = O_CREAT|O_WRONLY|O_TRUNC; break;
163  case 'a': access = O_CREAT|O_WRONLY|O_APPEND; break;
164  default :
165  errno = EINVAL;
166  return NULL;
167  }
168  while (*m) {
169  if (*m == '+') {
170  access &= ~(O_RDONLY | O_WRONLY);
171  access |= O_RDWR;
172  } else if (*m == 'b') {
173 #ifdef O_BINARY
174  access |= O_BINARY;
175 #endif
176  } else if (*m) {
177  errno = EINVAL;
178  return NULL;
179  }
180  m++;
181  }
182  fd = avpriv_open(path, access, 0666);
183  if (fd == -1)
184  return NULL;
185  return fdopen(fd, mode);
186 }
#define NULL
Definition: coverity.c:32
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
Memory handling functions.
#define O_BINARY
FILE * av_fopen_utf8(const char *path, const char *mode)
Open a file using a UTF-8 filename.
Definition: file_open.c:154
int avpriv_tempfile(const char *prefix, char **filename, int log_offset, void *log_ctx)
Wrapper to work around the lack of mkstemp() on mingw.
Definition: file_open.c:106
#define av_malloc(s)
mode
Definition: f_perms.c:27
int avpriv_open(const char *filename, int flags,...)
A wrapper for open() setting O_CLOEXEC.
Definition: file_open.c:66
#define av_log(a,...)
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
av_default_item_name
#define AVERROR(e)
Definition: error.h:43
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:197
common internal API header
int log_offset
Definition: file.c:40
char * av_strdup(const char *s)
Duplicate a string.
Definition: mem.c:267
#define O_EXCL
static const AVClass file_log_ctx_class
Definition: file_open.c:101
Describe the class of an AVClass context structure.
Definition: log.h:67
void * log_ctx
Definition: file.c:41
#define snprintf
Definition: snprintf.h:34
static int flags
Definition: cpu.c:47
int len
#define av_freep(p)