about summary refs log tree commit diff
path: root/iconv/gconv_parseconfdir.h
blob: abde05806751761c82ab7af0f407a6b9a60aaf29 (plain) (blame)
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
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
/* Handle configuration data.
   Copyright (C) 2021-2024 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
   <https://www.gnu.org/licenses/>.  */

#include <dirent.h>
#include <libc-symbols.h>
#include <locale.h>
#include <sys/types.h>

#if IS_IN (libc)
# include <libio/libioP.h>
# define __getdelim(line, len, c, fp) __getdelim (line, len, c, fp)

# undef isspace
# define isspace(__c) __isspace_l ((__c), _nl_C_locobj_ptr)
# define asprintf __asprintf
# define opendir __opendir
# define readdir64 __readdir64
# define closedir __closedir
# define mempcpy __mempcpy
# define struct_stat64 struct __stat64_t64
# define lstat64 __lstat64_time64
# define feof_unlocked __feof_unlocked
#else
# define struct_stat64 struct stat64
#endif

/* Name of the file containing the module information in the directories
   along the path.  */
static const char gconv_conf_filename[] = "gconv-modules";

static void add_alias (char *);
static void add_module (char *, const char *, size_t, int);

/* Read the next configuration file.  */
static bool
read_conf_file (const char *filename, const char *directory, size_t dir_len)
{
  /* Note the file is opened with cancellation in the I/O functions
     disabled.  */
  FILE *fp = fopen (filename, "rce");
  char *line = NULL;
  size_t line_len = 0;
  static int modcounter;

  /* Don't complain if a file is not present or readable, simply silently
     ignore it.  */
  if (fp == NULL)
    return false;

  /* No threads reading from this stream.  */
  __fsetlocking (fp, FSETLOCKING_BYCALLER);

  /* Process the known entries of the file.  Comments start with `#' and
     end with the end of the line.  Empty lines are ignored.  */
  while (!feof_unlocked (fp))
    {
      char *rp, *endp, *word;
      ssize_t n = __getdelim (&line, &line_len, '\n', fp);
      if (n < 0)
	/* An error occurred.  */
	break;

      rp = line;
      /* Terminate the line (excluding comments or newline) by an NUL byte
	 to simplify the following code.  */
      endp = strchr (rp, '#');
      if (endp != NULL)
	*endp = '\0';
      else
	if (rp[n - 1] == '\n')
	  rp[n - 1] = '\0';

      while (isspace (*rp))
	++rp;

      /* If this is an empty line go on with the next one.  */
      if (rp == endp)
	continue;

      word = rp;
      while (*rp != '\0' && !isspace (*rp))
	++rp;

      if (rp - word == sizeof ("alias") - 1
	  && memcmp (word, "alias", sizeof ("alias") - 1) == 0)
	add_alias (rp);
      else if (rp - word == sizeof ("module") - 1
	       && memcmp (word, "module", sizeof ("module") - 1) == 0)
	add_module (rp, directory, dir_len, modcounter++);
      /* else */
	/* Otherwise ignore the line.  */
    }

  free (line);

  fclose (fp);
  return true;
}

/* Prefix DIR (with length DIR_LEN) with PREFIX if the latter is non-NULL and
   parse configuration in it.  */

static __always_inline bool
gconv_parseconfdir (const char *prefix, const char *dir, size_t dir_len)
{
  /* No slash needs to be inserted between dir and gconv_conf_filename; dir
     already ends in a slash.  The additional 2 is to accommodate the ".d"
     when looking for configuration files in gconv-modules.d.  */
  size_t buflen = dir_len + sizeof (gconv_conf_filename) + 2;
  char *buf = malloc (buflen + (prefix != NULL ? strlen (prefix) : 0));
  char *cp = buf;
  bool found = false;

  if (buf == NULL)
    return false;

  if (prefix != NULL)
    cp = stpcpy (cp, prefix);

  cp = mempcpy (mempcpy (cp, dir, dir_len), gconv_conf_filename,
		sizeof (gconv_conf_filename));

  /* Read the gconv-modules configuration file first.  */
  found = read_conf_file (buf, dir, dir_len);

  /* Next, see if there is a gconv-modules.d directory containing
     configuration files and if it is non-empty.  */
  cp--;
  cp[0] = '.';
  cp[1] = 'd';
  cp[2] = '\0';

  DIR *confdir = opendir (buf);
  if (confdir != NULL)
    {
      struct dirent64 *ent;
      while ((ent = readdir64 (confdir)) != NULL)
	{
	  if (ent->d_type != DT_REG && ent->d_type != DT_UNKNOWN)
	    continue;

	  size_t len = strlen (ent->d_name);
	  const char *suffix = ".conf";

	  if (len > strlen (suffix)
	      && strcmp (ent->d_name + len - strlen (suffix), suffix) == 0)
	    {
	      char *conf;
	      struct_stat64 st;
	      if (asprintf (&conf, "%s/%s", buf, ent->d_name) < 0)
		continue;

	      if (ent->d_type != DT_UNKNOWN
		  || (lstat64 (conf, &st) != -1 && S_ISREG (st.st_mode)))
		found |= read_conf_file (conf, dir, dir_len);

	      free (conf);
	    }
	}
      closedir (confdir);
    }
  free (buf);
  return found;
}