aboutsummaryrefslogtreecommitdiff
path: root/sysdeps/unix/sysv/linux/futimes.c
blob: 1b1f005073f710298818d496ebde9e77da8a8e73 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
/* futimes -- change access and modification times of open file.  Linux version.
   Copyright (C) 2002-2014 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

#include <errno.h>
#include <sysdep.h>
#include <string.h>
#include <time.h>
#include <utime.h>
#include <sys/time.h>
#include <_itoa.h>
#include <fcntl.h>

#include <kernel-features.h>


#if defined __NR_utimensat && !defined __ASSUME_UTIMENSAT
static int miss_utimensat;
#endif

/* Change the access time of the file associated with FD to TVP[0] and
   the modification time of FILE to TVP[1].

   Starting with 2.6.22 the Linux kernel has the utimensat syscall which
   can be used to implement futimes.  Earlier kernels have no futimes()
   syscall so we use the /proc filesystem.  */
int
__futimes (int fd, const struct timeval tvp[2])
{
  /* The utimensat system call expects timespec not timeval.  */
  struct timespec ts[2];
  if (tvp != NULL)
    {
      if (tvp[0].tv_usec < 0 || tvp[0].tv_usec >= 1000000
          || tvp[1].tv_usec < 0 || tvp[1].tv_usec >= 1000000)
	{
	  __set_errno (EINVAL);
	  return -1;
	}

      TIMEVAL_TO_TIMESPEC (&tvp[0], &ts[0]);
      TIMEVAL_TO_TIMESPEC (&tvp[1], &ts[1]);
    }

#ifdef __ASSUME_UTIMENSAT
  return INLINE_SYSCALL (utimensat, 4, fd, NULL, tvp ? &ts : NULL, 0);
#else
  int result;
# ifdef __NR_utimensat
  if (!__builtin_expect (miss_utimensat, 0))
    {
      result = INLINE_SYSCALL (utimensat, 4, fd, NULL, tvp ? &ts : NULL, 0);
      if (__builtin_expect (result, 0) != -1 || errno != ENOSYS)
	return result;

      miss_utimensat = 1;
    }
# endif

  static const char selffd[] = "/proc/self/fd/";
  char fname[sizeof (selffd) + 3 * sizeof (int)];
  fname[sizeof (fname) - 1] = '\0';
  char *cp = _itoa_word ((unsigned int) fd, fname + sizeof (fname) - 1, 10, 0);
  cp = memcpy (cp - sizeof (selffd) + 1, selffd, sizeof (selffd) - 1);

# ifdef __NR_utimes
  result = INLINE_SYSCALL (utimes, 2, cp, tvp);
#  ifndef __ASSUME_UTIMES
  if (result == -1 && errno == ENOSYS)
#  endif
# endif
    {
      /* The utimes() syscall does not exist or is not available in the
	 used kernel.  Use utime().  For this we have to convert to the
	 data format utime() expects.  */
# ifndef __ASSUME_UTIMES
      struct utimbuf buf;
      struct utimbuf *times;

      if (tvp != NULL)
	{
	  times = &buf;
	  buf.actime = tvp[0].tv_sec;
	  buf.modtime = tvp[1].tv_sec;
	}
      else
	times = NULL;

      result = INLINE_SYSCALL (utime, 2, cp, times);
# endif
    }

  if (result == -1)
    /* Check for errors that result from failing to find /proc.
       This means we can't do futimes at all, so return ENOSYS
       rather than some confusing error.  */
    switch (errno)
      {
      case EACCES:
	if (tvp == NULL)  /* Could be a path problem or a file problem.  */
	  break;
	/*FALLTHROUGH*/
      case ELOOP:
      case ENAMETOOLONG:
      case ENOTDIR:
	__set_errno (ENOSYS);
	break;

      case ENOENT:
	/* Validate the file descriptor by letting fcntl set errno to
	   EBADF if it's bogus.  Otherwise it's a /proc issue.  */
# if !defined __NR_fcntl && defined __NR_fcntl64
#  define __NR_fcntl __NR_fcntl64
# endif
	if (INLINE_SYSCALL (fcntl, 3, fd, F_GETFD, 0) != -1)
	  __set_errno (ENOSYS);
	break;
      }

  return result;
#endif
}
weak_alias (__futimes, futimes)