1 /* fpathconf -- adjusted for busybox
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, see
17 <http://www.gnu.org/licenses/>. */
18
19 #include <errno.h>
20 #include <unistd.h>
21 #include <limits.h>
22 #include <stddef.h>
23 #include <fcntl.h>
24 #include <sys/stat.h>
25 #include <sys/statfs.h>
26
27 #define STAT stat64
28 #define FSTAT fstat64
29
30 #ifndef __USE_FILE_OFFSET64
31 extern int fstatfs (int __fildes, struct statfs *__buf)
32 __THROW __nonnull ((2));
33 #else
34 # ifdef __REDIRECT_NTH
35 extern int __REDIRECT_NTH (fstatfs, (int __fildes, struct statfs *__buf),
36 fstatfs64) __nonnull ((2));
37 # else
38 # define fstatfs fstatfs64
39 # endif
40 #endif
41
42 extern __typeof(fstatfs) __libc_fstatfs;
43
44 /* The Linux kernel headers mention this as a kind of generic value. */
45 #define LINUX_LINK_MAX 127
46
47
48 /* Get file-specific information about descriptor FD. */
fpathconf(int fd,int name)49 long int fpathconf(int fd, int name)
50 {
51 if (fd < 0)
52 {
53 __set_errno (EBADF);
54 return -1;
55 }
56
57 if (name == _PC_LINK_MAX)
58 {
59 /* Cut some corners */
60 #if 0
61 struct statfs fsbuf;
62
63 /* Determine the filesystem type. */
64 if (__libc_fstatfs (fd, &fsbuf) < 0)
65 {
66 if (errno == ENOSYS)
67 /* not possible, return the default value. */
68 return LINUX_LINK_MAX;
69
70 /* Some error occured. */
71 return -1;
72 }
73
74 switch (fsbuf.f_type)
75 {
76 case EXT2_SUPER_MAGIC:
77 return EXT2_LINK_MAX;
78
79 case MINIX_SUPER_MAGIC:
80 case MINIX_SUPER_MAGIC2:
81 return MINIX_LINK_MAX;
82
83 case MINIX2_SUPER_MAGIC:
84 case MINIX2_SUPER_MAGIC2:
85 return MINIX2_LINK_MAX;
86
87 case XENIX_SUPER_MAGIC:
88 return XENIX_LINK_MAX;
89
90 case SYSV4_SUPER_MAGIC:
91 case SYSV2_SUPER_MAGIC:
92 return SYSV_LINK_MAX;
93
94 case COH_SUPER_MAGIC:
95 return COH_LINK_MAX;
96
97 case UFS_MAGIC:
98 case UFS_CIGAM:
99 return UFS_LINK_MAX;
100
101 case REISERFS_SUPER_MAGIC:
102 return REISERFS_LINK_MAX;
103
104 default:
105 return LINUX_LINK_MAX;
106 }
107 #else
108 return LINUX_LINK_MAX;
109 #endif
110 }
111
112 switch (name)
113 {
114 default:
115 __set_errno (EINVAL);
116 return -1;
117
118 case _PC_MAX_CANON:
119 #ifdef MAX_CANON
120 return MAX_CANON;
121 #else
122 return -1;
123 #endif
124
125 case _PC_MAX_INPUT:
126 #ifdef MAX_INPUT
127 return MAX_INPUT;
128 #else
129 return -1;
130 #endif
131
132 case _PC_NAME_MAX:
133 #ifdef NAME_MAX
134 {
135 struct statfs buf;
136 int save_errno = errno;
137
138 if (__libc_fstatfs (fd, &buf) < 0)
139 {
140 if (errno == ENOSYS)
141 {
142 errno = save_errno;
143 return NAME_MAX;
144 }
145 return -1;
146 }
147 else
148 {
149 #ifdef _STATFS_F_NAMELEN
150 return buf.f_namelen;
151 #else
152 # ifdef _STATFS_F_NAME_MAX
153 return buf.f_name_max;
154 # else
155 return NAME_MAX;
156 # endif
157 #endif
158 }
159 }
160 #else
161 return -1;
162 #endif
163
164 case _PC_PATH_MAX:
165 #ifdef PATH_MAX
166 return PATH_MAX;
167 #else
168 return -1;
169 #endif
170
171 case _PC_PIPE_BUF:
172 #ifdef PIPE_BUF
173 return PIPE_BUF;
174 #else
175 return -1;
176 #endif
177
178 case _PC_CHOWN_RESTRICTED:
179 #ifdef _POSIX_CHOWN_RESTRICTED
180 return _POSIX_CHOWN_RESTRICTED;
181 #else
182 return -1;
183 #endif
184
185 case _PC_NO_TRUNC:
186 #ifdef _POSIX_NO_TRUNC
187 return _POSIX_NO_TRUNC;
188 #else
189 return -1;
190 #endif
191
192 case _PC_VDISABLE:
193 #ifdef _POSIX_VDISABLE
194 return _POSIX_VDISABLE;
195 #else
196 return -1;
197 #endif
198
199 case _PC_SYNC_IO:
200 #ifdef _POSIX_SYNC_IO
201 return _POSIX_SYNC_IO;
202 #else
203 return -1;
204 #endif
205
206 case _PC_ASYNC_IO:
207 #if defined _POSIX_ASYNC_IO
208 {
209 /* AIO is only allowed on regular files and block devices. */
210 struct STAT st;
211
212 if (FSTAT (fd, &st) < 0 || (! S_ISREG (st.st_mode) && ! S_ISBLK (st.st_mode)))
213 return -1;
214 else
215 return 1;
216 }
217 #else
218 return -1;
219 #endif
220
221 case _PC_PRIO_IO:
222 #ifdef _POSIX_PRIO_IO
223 return _POSIX_PRIO_IO;
224 #else
225 return -1;
226 #endif
227
228 case _PC_SOCK_MAXBUF:
229 #ifdef SOCK_MAXBUF
230 return SOCK_MAXBUF;
231 #else
232 return -1;
233 #endif
234
235 case _PC_FILESIZEBITS:
236 #ifdef FILESIZEBITS
237 return FILESIZEBITS;
238 #else
239 /* We let platforms with larger file sizes overwrite this value. */
240 return 32;
241 #endif
242
243 /* Be lazy -- skip these */
244 case _PC_REC_INCR_XFER_SIZE:
245 case _PC_REC_MAX_XFER_SIZE:
246 case _PC_REC_MIN_XFER_SIZE:
247 case _PC_REC_XFER_ALIGN:
248 case _PC_ALLOC_SIZE_MIN:
249 case _PC_SYMLINK_MAX:
250 return -1;
251 }
252
253 }
254
255