summaryrefslogtreecommitdiffstats
path: root/util/editenv.c
blob: c532b046f0e3510eae940f219630ad1c79ee2ca4 (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
/* editenv.c - tool to edit environment block.  */
/*
 *  GRUB  --  GRand Unified Bootloader
 *  Copyright (C) 2008,2009,2010,2013 Free Software Foundation, Inc.
 *
 *  GRUB is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  GRUB 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <config.h>
#include <grub/types.h>
#include <grub/emu/misc.h>
#include <grub/util/misc.h>
#include <grub/util/install.h>
#include <grub/lib/envblk.h>
#include <grub/i18n.h>
#include <grub/emu/hostfile.h>

#include <errno.h>
#include <string.h>
#if !defined(_WIN32)
#include <libgen.h>
#endif

#define DEFAULT_ENVBLK_SIZE	1024
#define GRUB_ENVBLK_MESSAGE	"# WARNING: Do not edit this file by tools other than "PACKAGE"-editenv!!!\n"

void
grub_util_create_envblk_file (const char *name)
{
  FILE *fp;
  char *buf, *pbuf, *namenew;
#if !defined(_WIN32)
  ssize_t size = 1;
  char *rename_target = xstrdup (name);
  int rc;
#endif

  buf = xmalloc (DEFAULT_ENVBLK_SIZE);

  namenew = xasprintf ("%s.new", name);
  fp = grub_util_fopen (namenew, "wb");
  if (! fp)
    grub_util_error (_("cannot open `%s': %s"), namenew,
		     strerror (errno));

  pbuf = buf;
  memcpy (pbuf, GRUB_ENVBLK_SIGNATURE, sizeof (GRUB_ENVBLK_SIGNATURE) - 1);
  pbuf += sizeof (GRUB_ENVBLK_SIGNATURE) - 1;
  memcpy (pbuf, GRUB_ENVBLK_MESSAGE, sizeof (GRUB_ENVBLK_MESSAGE) - 1);
  pbuf += sizeof (GRUB_ENVBLK_MESSAGE) - 1;
  memset (pbuf , '#',
          DEFAULT_ENVBLK_SIZE - sizeof (GRUB_ENVBLK_SIGNATURE) - sizeof (GRUB_ENVBLK_MESSAGE) + 2);

  if (fwrite (buf, 1, DEFAULT_ENVBLK_SIZE, fp) != DEFAULT_ENVBLK_SIZE)
    grub_util_error (_("cannot write to `%s': %s"), namenew,
		     strerror (errno));


  if (grub_util_file_sync (fp) < 0)
    grub_util_error (_("cannot sync `%s': %s"), namenew, strerror (errno));
  free (buf);
  fclose (fp);

#if defined(_WIN32)
  if (grub_util_rename (namenew, name) < 0)
    grub_util_error (_("cannot rename the file %s to %s"), namenew, name);
#else
  while (1)
    {
      char *linkbuf;
      ssize_t retsize;

      linkbuf = xmalloc (size + 1);
      retsize = grub_util_readlink (rename_target, linkbuf, size);
      if (retsize < 0 && (errno == ENOENT || errno == EINVAL))
        {
          free (linkbuf);
          break;
        }
      else if (retsize < 0)
        {
          free (linkbuf);
          grub_util_error (_("cannot rename the file %s to %s: %m"), namenew, name);
        }
      else if (retsize == size)
        {
          free (linkbuf);
          size += 128;
          continue;
        }

      linkbuf[retsize] = '\0';
      if (linkbuf[0] == '/')
        {
          free (rename_target);
          rename_target = linkbuf;
        }
      else
        {
          char *dbuf = xstrdup (rename_target);
          const char *dir = dirname (dbuf);

          free (rename_target);
          rename_target = xasprintf ("%s/%s", dir, linkbuf);
          free (dbuf);
          free (linkbuf);
        }
    }

  rc = grub_util_rename (namenew, rename_target);
  if (rc < 0 && errno == EXDEV)
    {
      rc = grub_install_copy_file (namenew, rename_target, 1);
      grub_util_unlink (namenew);
    }

  free (rename_target);

  if (rc < 0)
    grub_util_error (_("cannot rename the file %s to %s: %m"), namenew, name);
#endif

  free (namenew);
}