1 | /* Copyright (C) 2000-2017 Free Software Foundation, Inc. |
2 | This file is part of the GNU C Library. |
3 | |
4 | This program is free software; you can redistribute it and/or modify |
5 | it under the terms of the GNU General Public License as published |
6 | by the Free Software Foundation; version 2 of the License, or |
7 | (at your option) any later version. |
8 | |
9 | This program 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 |
12 | GNU General Public License for more details. |
13 | |
14 | You should have received a copy of the GNU General Public License |
15 | along with this program; if not, see <http://www.gnu.org/licenses/>. */ |
16 | |
17 | #include <dirent.h> |
18 | #include <errno.h> |
19 | #include <error.h> |
20 | #include <fcntl.h> |
21 | #include <libintl.h> |
22 | #include <spawn.h> |
23 | #include <stdio.h> |
24 | #include <stdlib.h> |
25 | #include <string.h> |
26 | #include <unistd.h> |
27 | #include <sys/stat.h> |
28 | |
29 | #include "localedef.h" |
30 | #include "charmap-dir.h" |
31 | |
32 | /* The data type of a charmap directory being traversed. */ |
33 | struct charmap_dir |
34 | { |
35 | DIR *dir; |
36 | /* The directory pathname, ending in a slash. */ |
37 | char *directory; |
38 | size_t directory_len; |
39 | /* Scratch area used for returning pathnames. */ |
40 | char *pathname; |
41 | size_t pathname_size; |
42 | }; |
43 | |
44 | /* Starts a charmap directory traversal. |
45 | Returns a CHARMAP_DIR, or NULL if the directory doesn't exist. */ |
46 | CHARMAP_DIR * |
47 | charmap_opendir (const char *directory) |
48 | { |
49 | struct charmap_dir *cdir; |
50 | DIR *dir; |
51 | size_t len; |
52 | int add_slash; |
53 | |
54 | dir = opendir (directory); |
55 | if (dir == NULL) |
56 | { |
57 | WITH_CUR_LOCALE (error (1, errno, gettext ("\ |
58 | cannot read character map directory `%s'" ), directory)); |
59 | return NULL; |
60 | } |
61 | |
62 | cdir = (struct charmap_dir *) xmalloc (sizeof (struct charmap_dir)); |
63 | cdir->dir = dir; |
64 | |
65 | len = strlen (directory); |
66 | add_slash = (len == 0 || directory[len - 1] != '/'); |
67 | cdir->directory = (char *) xmalloc (len + add_slash + 1); |
68 | memcpy (cdir->directory, directory, len); |
69 | if (add_slash) |
70 | cdir->directory[len] = '/'; |
71 | cdir->directory[len + add_slash] = '\0'; |
72 | cdir->directory_len = len + add_slash; |
73 | |
74 | cdir->pathname = NULL; |
75 | cdir->pathname_size = 0; |
76 | |
77 | return cdir; |
78 | } |
79 | |
80 | /* Reads the next directory entry. |
81 | Returns its charmap name, or NULL if past the last entry or upon error. |
82 | The storage returned may be overwritten by a later charmap_readdir |
83 | call on the same CHARMAP_DIR. */ |
84 | const char * |
85 | charmap_readdir (CHARMAP_DIR *cdir) |
86 | { |
87 | for (;;) |
88 | { |
89 | struct dirent64 *dirent; |
90 | size_t len; |
91 | size_t size; |
92 | char *filename; |
93 | mode_t mode; |
94 | |
95 | dirent = readdir64 (cdir->dir); |
96 | if (dirent == NULL) |
97 | return NULL; |
98 | if (strcmp (dirent->d_name, "." ) == 0) |
99 | continue; |
100 | if (strcmp (dirent->d_name, ".." ) == 0) |
101 | continue; |
102 | |
103 | len = strlen (dirent->d_name); |
104 | |
105 | size = cdir->directory_len + len + 1; |
106 | if (size > cdir->pathname_size) |
107 | { |
108 | free (cdir->pathname); |
109 | if (size < 2 * cdir->pathname_size) |
110 | size = 2 * cdir->pathname_size; |
111 | cdir->pathname = (char *) xmalloc (size); |
112 | cdir->pathname_size = size; |
113 | } |
114 | |
115 | stpcpy (stpcpy (cdir->pathname, cdir->directory), dirent->d_name); |
116 | filename = cdir->pathname + cdir->directory_len; |
117 | |
118 | #ifdef _DIRENT_HAVE_D_TYPE |
119 | if (dirent->d_type != DT_UNKNOWN && dirent->d_type != DT_LNK) |
120 | mode = DTTOIF (dirent->d_type); |
121 | else |
122 | #endif |
123 | { |
124 | struct stat64 statbuf; |
125 | |
126 | if (stat64 (cdir->pathname, &statbuf) < 0) |
127 | continue; |
128 | |
129 | mode = statbuf.st_mode; |
130 | } |
131 | |
132 | if (!S_ISREG (mode)) |
133 | continue; |
134 | |
135 | /* For compressed charmaps, the canonical charmap name does not |
136 | include the extension. */ |
137 | if (len > 3 && memcmp (&filename[len - 3], ".gz" , 3) == 0) |
138 | filename[len - 3] = '\0'; |
139 | else if (len > 4 && memcmp (&filename[len - 4], ".bz2" , 4) == 0) |
140 | filename[len - 4] = '\0'; |
141 | |
142 | return filename; |
143 | } |
144 | } |
145 | |
146 | /* Finishes a charmap directory traversal, and frees the resources |
147 | attached to the CHARMAP_DIR. */ |
148 | int |
149 | charmap_closedir (CHARMAP_DIR *cdir) |
150 | { |
151 | DIR *dir = cdir->dir; |
152 | |
153 | free (cdir->directory); |
154 | free (cdir->pathname); |
155 | free (cdir); |
156 | return closedir (dir); |
157 | } |
158 | |
159 | /* Creates a subprocess decompressing the given pathname, and returns |
160 | a stream reading its output (the decompressed data). */ |
161 | static |
162 | FILE * |
163 | fopen_uncompressed (const char *pathname, const char *compressor) |
164 | { |
165 | int pfd; |
166 | |
167 | pfd = open (pathname, O_RDONLY); |
168 | if (pfd >= 0) |
169 | { |
170 | struct stat64 statbuf; |
171 | int fd[2]; |
172 | |
173 | if (fstat64 (pfd, &statbuf) >= 0 |
174 | && S_ISREG (statbuf.st_mode) |
175 | && pipe (fd) >= 0) |
176 | { |
177 | char *argv[4] |
178 | = { (char *) compressor, (char *) "-d" , (char *) "-c" , NULL }; |
179 | posix_spawn_file_actions_t actions; |
180 | |
181 | if (posix_spawn_file_actions_init (&actions) == 0) |
182 | { |
183 | if (posix_spawn_file_actions_adddup2 (&actions, |
184 | fd[1], STDOUT_FILENO) == 0 |
185 | && posix_spawn_file_actions_addclose (&actions, fd[1]) == 0 |
186 | && posix_spawn_file_actions_addclose (&actions, fd[0]) == 0 |
187 | && posix_spawn_file_actions_adddup2 (&actions, |
188 | pfd, STDIN_FILENO) == 0 |
189 | && posix_spawn_file_actions_addclose (&actions, pfd) == 0 |
190 | && posix_spawnp (NULL, compressor, &actions, NULL, |
191 | argv, environ) == 0) |
192 | { |
193 | posix_spawn_file_actions_destroy (&actions); |
194 | close (fd[1]); |
195 | close (pfd); |
196 | return fdopen (fd[0], "r" ); |
197 | } |
198 | posix_spawn_file_actions_destroy (&actions); |
199 | } |
200 | close (fd[1]); |
201 | close (fd[0]); |
202 | } |
203 | close (pfd); |
204 | } |
205 | return NULL; |
206 | } |
207 | |
208 | /* Opens a charmap for reading, given its name (not an alias name). */ |
209 | FILE * |
210 | charmap_open (const char *directory, const char *name) |
211 | { |
212 | size_t dlen = strlen (directory); |
213 | int add_slash = (dlen == 0 || directory[dlen - 1] != '/'); |
214 | size_t nlen = strlen (name); |
215 | char *pathname; |
216 | char *p; |
217 | FILE *stream; |
218 | |
219 | pathname = alloca (dlen + add_slash + nlen + 5); |
220 | p = stpcpy (pathname, directory); |
221 | if (add_slash) |
222 | *p++ = '/'; |
223 | p = stpcpy (p, name); |
224 | |
225 | stream = fopen (pathname, "rm" ); |
226 | if (stream != NULL) |
227 | return stream; |
228 | |
229 | memcpy (p, ".gz" , 4); |
230 | stream = fopen_uncompressed (pathname, "gzip" ); |
231 | if (stream != NULL) |
232 | return stream; |
233 | |
234 | memcpy (p, ".bz2" , 5); |
235 | stream = fopen_uncompressed (pathname, "bzip2" ); |
236 | if (stream != NULL) |
237 | return stream; |
238 | |
239 | return NULL; |
240 | } |
241 | |
242 | /* An empty alias list. Avoids the need to return NULL from |
243 | charmap_aliases. */ |
244 | static char *empty[1]; |
245 | |
246 | /* Returns a NULL terminated list of alias names of a charmap. */ |
247 | char ** |
248 | charmap_aliases (const char *directory, const char *name) |
249 | { |
250 | FILE *stream; |
251 | char **aliases; |
252 | size_t naliases; |
253 | |
254 | stream = charmap_open (directory, name); |
255 | if (stream == NULL) |
256 | return empty; |
257 | |
258 | aliases = NULL; |
259 | naliases = 0; |
260 | |
261 | while (!feof (stream)) |
262 | { |
263 | char *alias = NULL; |
264 | char junk[BUFSIZ]; |
265 | |
266 | if (fscanf (stream, " <code_set_name> %ms" , &alias) == 1 |
267 | || fscanf (stream, "%% alias %ms" , &alias) == 1) |
268 | { |
269 | aliases = (char **) xrealloc (aliases, |
270 | (naliases + 2) * sizeof (char *)); |
271 | aliases[naliases++] = alias; |
272 | } |
273 | |
274 | /* Read the rest of the line. */ |
275 | if (fgets (junk, sizeof junk, stream) != NULL) |
276 | { |
277 | if (strstr (junk, "CHARMAP" ) != NULL) |
278 | /* We cannot expect more aliases from now on. */ |
279 | break; |
280 | |
281 | while (strchr (junk, '\n') == NULL |
282 | && fgets (junk, sizeof junk, stream) != NULL) |
283 | continue; |
284 | } |
285 | } |
286 | |
287 | fclose (stream); |
288 | |
289 | if (naliases == 0) |
290 | return empty; |
291 | |
292 | aliases[naliases] = NULL; |
293 | return aliases; |
294 | } |
295 | |
296 | /* Frees an alias list returned by charmap_aliases. */ |
297 | void |
298 | charmap_free_aliases (char **aliases) |
299 | { |
300 | if (aliases != empty) |
301 | { |
302 | char **p; |
303 | |
304 | for (p = aliases; *p; p++) |
305 | free (*p); |
306 | |
307 | free (aliases); |
308 | } |
309 | } |
310 | |