1 /* Linux specific extensions to pathconf.
2 Copyright (C) 1991,95,96,98,99,2000,2001 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18 02111-1307 USA. */
19
20 /* Modified for newlib July 19, 2002 - Jeff Johnston */
21
22 #include <errno.h>
23 #include <stddef.h>
24 #include <unistd.h>
25 #include <limits.h>
26 #include <fcntl.h>
27 #include <sys/stat.h>
28 #include <sys/statfs.h>
29 #include <sys/statvfs.h>
30 #include <machine/weakalias.h>
31 #include "linux_fsinfo.h"
32
33 /* The Linux kernel header mentioned this as a kind of generic value. */
34 #define LINUX_LINK_MAX 127
35
36 static long int posix_pathconf (const char *path, int name);
37
38
39 /* Get file-specific information about descriptor FD. */
40 long int
__pathconf(path,name)41 __pathconf (path, name)
42 const char *path;
43 int name;
44 {
45 if (name == _PC_LINK_MAX)
46 {
47 struct statfs fsbuf;
48
49 /* Determine the filesystem type. */
50 if (__statfs (path, &fsbuf) < 0)
51 {
52 if (errno == ENOSYS)
53 /* not possible, return the default value. */
54 return LINUX_LINK_MAX;
55
56 /* Some error occured. */
57 return -1;
58 }
59
60 switch (fsbuf.f_type)
61 {
62 case EXT2_SUPER_MAGIC:
63 return EXT2_LINK_MAX;
64
65 case MINIX_SUPER_MAGIC:
66 case MINIX_SUPER_MAGIC2:
67 return MINIX_LINK_MAX;
68
69 case MINIX2_SUPER_MAGIC:
70 case MINIX2_SUPER_MAGIC2:
71 return MINIX2_LINK_MAX;
72
73 case XENIX_SUPER_MAGIC:
74 return XENIX_LINK_MAX;
75
76 case SYSV4_SUPER_MAGIC:
77 case SYSV2_SUPER_MAGIC:
78 return SYSV_LINK_MAX;
79
80 case COH_SUPER_MAGIC:
81 return COH_LINK_MAX;
82
83 case UFS_MAGIC:
84 case UFS_CIGAM:
85 return UFS_LINK_MAX;
86
87 case REISERFS_SUPER_MAGIC:
88 return REISERFS_LINK_MAX;
89
90 default:
91 return LINUX_LINK_MAX;
92 }
93 }
94
95 return posix_pathconf (path, name);
96 }
97
98 /* Get file-specific information about PATH. */
99 static long int
posix_pathconf(const char * path,int name)100 posix_pathconf (const char *path, int name)
101 {
102 if (path[0] == '\0')
103 {
104 __set_errno (ENOENT);
105 return -1;
106 }
107
108 switch (name)
109 {
110 default:
111 __set_errno (EINVAL);
112 return -1;
113
114 case _PC_LINK_MAX:
115 #ifdef LINK_MAX
116 return LINK_MAX;
117 #else
118 return -1;
119 #endif
120
121 case _PC_MAX_CANON:
122 #ifdef MAX_CANON
123 return MAX_CANON;
124 #else
125 return -1;
126 #endif
127
128 case _PC_MAX_INPUT:
129 #ifdef MAX_INPUT
130 return MAX_INPUT;
131 #else
132 return -1;
133 #endif
134
135 case _PC_NAME_MAX:
136 #ifdef NAME_MAX
137 {
138 struct statfs buf;
139 int save_errno = errno;
140
141 if (__statfs (path, &buf) < 0)
142 {
143 if (errno == ENOSYS)
144 {
145 errno = save_errno;
146 return NAME_MAX;
147 }
148 return -1;
149 }
150 else
151 {
152 #ifdef _STATFS_F_NAMELEN
153 return buf.f_namelen;
154 #else
155 # ifdef _STATFS_F_NAME_MAX
156 return buf.f_name_max;
157 # else
158 return NAME_MAX;
159 # endif
160 #endif
161 }
162 }
163 #else
164 return -1;
165 #endif
166
167 case _PC_PATH_MAX:
168 #ifdef PATH_MAX
169 return PATH_MAX;
170 #else
171 return -1;
172 #endif
173
174 case _PC_PIPE_BUF:
175 #ifdef PIPE_BUF
176 return PIPE_BUF;
177 #else
178 return -1;
179 #endif
180
181 case _PC_CHOWN_RESTRICTED:
182 #ifdef _POSIX_CHOWN_RESTRICTED
183 return _POSIX_CHOWN_RESTRICTED;
184 #else
185 return -1;
186 #endif
187
188 case _PC_NO_TRUNC:
189 #ifdef _POSIX_NO_TRUNC
190 return _POSIX_NO_TRUNC;
191 #else
192 return -1;
193 #endif
194
195 case _PC_VDISABLE:
196 #ifdef _POSIX_VDISABLE
197 return _POSIX_VDISABLE;
198 #else
199 return -1;
200 #endif
201
202 case _PC_SYNC_IO:
203 #ifdef _POSIX_SYNC_IO
204 return _POSIX_SYNC_IO;
205 #else
206 return -1;
207 #endif
208
209 case _PC_ASYNC_IO:
210 #ifdef _POSIX_ASYNC_IO
211 {
212 /* AIO is only allowed on regular files and block devices. */
213 struct stat64 st;
214
215 if (stat64 (path, &st) < 0
216 || (! S_ISREG (st.st_mode) && ! S_ISBLK (st.st_mode)))
217 return -1;
218 else
219 return 1;
220 }
221 #else
222 return -1;
223 #endif
224
225 case _PC_PRIO_IO:
226 #ifdef _POSIX_PRIO_IO
227 return _POSIX_PRIO_IO;
228 #else
229 return -1;
230 #endif
231
232 case _PC_SOCK_MAXBUF:
233 #ifdef SOCK_MAXBUF
234 return SOCK_MAXBUF;
235 #else
236 return -1;
237 #endif
238
239 case _PC_FILESIZEBITS:
240 #ifdef FILESIZEBITS
241 return FILESIZEBITS;
242 #else
243 /* We let platforms with larger file sizes overwrite this value. */
244 return 32;
245 #endif
246
247 case _PC_REC_INCR_XFER_SIZE:
248 /* XXX It is not entirely clear what the limit is supposed to do.
249 What is incremented? */
250 return -1;
251
252 case _PC_REC_MAX_XFER_SIZE:
253 /* XXX It is not entirely clear what the limit is supposed to do.
254 In general there is no top limit of the number of bytes which
255 case be transported at once. */
256 return -1;
257
258 case _PC_REC_MIN_XFER_SIZE:
259 {
260 /* XXX It is not entirely clear what the limit is supposed to do.
261 I assume this is the block size of the filesystem. */
262 struct statvfs64 sv;
263
264 if (__statvfs64 (path, &sv) < 0)
265 return -1;
266 return sv.f_bsize;
267 }
268
269 case _PC_REC_XFER_ALIGN:
270 {
271 /* XXX It is not entirely clear what the limit is supposed to do.
272 I assume that the number should reflect the minimal block
273 alignment. */
274 struct statvfs64 sv;
275
276 if (__statvfs64 (path, &sv) < 0)
277 return -1;
278 return sv.f_frsize;
279 }
280
281 case _PC_ALLOC_SIZE_MIN:
282 {
283 /* XXX It is not entirely clear what the limit is supposed to do.
284 I assume that the number should reflect the minimal block
285 alignment. */
286 struct statvfs64 sv;
287
288 if (__statvfs64 (path, &sv) < 0)
289 return -1;
290 return sv.f_frsize;
291 }
292
293 case _PC_SYMLINK_MAX:
294 /* In general there are no limits. If a system has one it should
295 overwrite this case. */
296 return -1;
297 }
298 }
299
300 weak_alias (__pathconf, pathconf)
301