1 /* Copyright (C) 1991,1995,1996,1998,2000,2001,2003
2 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 /* pathconf -- adjusted for busybox */
20
21 /* It would be great it this could be implemented using fpathconf,
22 * but that doesn't work out very well (think FIFOs and sockets) */
23
24 #include <errno.h>
25 #include <stddef.h>
26 #include <unistd.h>
27 #include <limits.h>
28 #include <fcntl.h>
29 #include <sys/stat.h>
30 #include <sys/statfs.h>
31
32 extern __typeof(statfs) __libc_statfs;
33
34
35 /* The Linux kernel headers mention this as a kind of generic value. */
36 #ifndef LINK_MAX
37 # define LINK_MAX 127
38 #endif
39
40 /* Get file-specific information about PATH. */
41 long int
pathconf(const char * path,int name)42 pathconf (const char *path, int name)
43 {
44 if (path[0] == '\0')
45 {
46 __set_errno (ENOENT);
47 return -1;
48 }
49
50 switch (name)
51 {
52 default:
53 __set_errno (EINVAL);
54 return -1;
55
56 case _PC_LINK_MAX:
57 #ifdef LINK_MAX
58 return LINK_MAX;
59 #else
60 return -1;
61 #endif
62
63 case _PC_MAX_CANON:
64 #ifdef MAX_CANON
65 return MAX_CANON;
66 #else
67 return -1;
68 #endif
69
70 case _PC_MAX_INPUT:
71 #ifdef MAX_INPUT
72 return MAX_INPUT;
73 #else
74 return -1;
75 #endif
76
77 case _PC_NAME_MAX:
78 #ifdef NAME_MAX
79 {
80 struct statfs buf;
81 int save_errno = errno;
82
83 if (__libc_statfs (path, &buf) < 0)
84 {
85 if (errno == ENOSYS)
86 {
87 errno = save_errno;
88 return NAME_MAX;
89 }
90 return -1;
91 }
92 else
93 {
94 #ifdef _STATFS_F_NAMELEN
95 return buf.f_namelen;
96 #else
97 # ifdef _STATFS_F_NAME_MAX
98 return buf.f_name_max;
99 # else
100 return NAME_MAX;
101 # endif
102 #endif
103 }
104 }
105 #else
106 return -1;
107 #endif
108
109 case _PC_PATH_MAX:
110 #ifdef PATH_MAX
111 return PATH_MAX;
112 #else
113 return -1;
114 #endif
115
116 case _PC_PIPE_BUF:
117 #ifdef PIPE_BUF
118 return PIPE_BUF;
119 #else
120 return -1;
121 #endif
122
123 case _PC_CHOWN_RESTRICTED:
124 #ifdef _POSIX_CHOWN_RESTRICTED
125 return _POSIX_CHOWN_RESTRICTED;
126 #else
127 return -1;
128 #endif
129
130 case _PC_NO_TRUNC:
131 #ifdef _POSIX_NO_TRUNC
132 return _POSIX_NO_TRUNC;
133 #else
134 return -1;
135 #endif
136
137 case _PC_VDISABLE:
138 #ifdef _POSIX_VDISABLE
139 return _POSIX_VDISABLE;
140 #else
141 return -1;
142 #endif
143
144 case _PC_SYNC_IO:
145 #ifdef _POSIX_SYNC_IO
146 return _POSIX_SYNC_IO;
147 #else
148 return -1;
149 #endif
150
151 case _PC_ASYNC_IO:
152 #if defined _POSIX_ASYNC_IO
153 {
154 /* AIO is only allowed on regular files and block devices. */
155 struct stat st;
156
157 if (stat (path, &st) < 0
158 || (! S_ISREG (st.st_mode) && ! S_ISBLK (st.st_mode)))
159 return -1;
160 else
161 return 1;
162 }
163 #else
164 return -1;
165 #endif
166
167 case _PC_PRIO_IO:
168 #ifdef _POSIX_PRIO_IO
169 return _POSIX_PRIO_IO;
170 #else
171 return -1;
172 #endif
173
174 case _PC_SOCK_MAXBUF:
175 #ifdef SOCK_MAXBUF
176 return SOCK_MAXBUF;
177 #else
178 return -1;
179 #endif
180
181 case _PC_FILESIZEBITS:
182 #ifdef FILESIZEBITS
183 return FILESIZEBITS;
184 #else
185 /* We let platforms with larger file sizes overwrite this value. */
186 return 32;
187 #endif
188
189 /* Be lazy -- skip these */
190 case _PC_REC_INCR_XFER_SIZE:
191 case _PC_REC_MAX_XFER_SIZE:
192 case _PC_REC_MIN_XFER_SIZE:
193 case _PC_REC_XFER_ALIGN:
194 case _PC_ALLOC_SIZE_MIN:
195 case _PC_SYMLINK_MAX:
196 return -1;
197 }
198 }
199