1/* Copyright (C) 1991-2016 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library 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 GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <http://www.gnu.org/licenses/>. */
17
18#include <errno.h>
19#include <stddef.h>
20#include <unistd.h>
21#include <limits.h>
22#include <sys/stat.h>
23#include <sys/statfs.h>
24#include <sys/statvfs.h>
25
26
27/* Get file-specific information about descriptor FD. */
28long int
29__fpathconf (int fd, int name)
30{
31 if (fd < 0)
32 {
33 __set_errno (EBADF);
34 return -1;
35 }
36
37 switch (name)
38 {
39 default:
40 __set_errno (EINVAL);
41 return -1;
42
43 case _PC_LINK_MAX:
44#ifdef LINK_MAX
45 return LINK_MAX;
46#else
47 return -1;
48#endif
49
50 case _PC_MAX_CANON:
51#ifdef MAX_CANON
52 return MAX_CANON;
53#else
54 return -1;
55#endif
56
57 case _PC_MAX_INPUT:
58#ifdef MAX_INPUT
59 return MAX_INPUT;
60#else
61 return -1;
62#endif
63
64 case _PC_NAME_MAX:
65#ifdef NAME_MAX
66 {
67 struct statvfs64 sv;
68 int save_errno = errno;
69
70 if (__fstatvfs64 (fd, &sv) < 0)
71 {
72 if (errno == ENOSYS)
73 {
74 __set_errno (save_errno);
75 return NAME_MAX;
76 }
77 else if (errno == ENODEV)
78 __set_errno (EINVAL);
79
80 return -1;
81 }
82 else
83 {
84 return sv.f_namemax;
85 }
86 }
87#else
88 return -1;
89#endif
90
91 case _PC_PATH_MAX:
92#ifdef PATH_MAX
93 return PATH_MAX;
94#else
95 return -1;
96#endif
97
98 case _PC_PIPE_BUF:
99#ifdef PIPE_BUF
100 return PIPE_BUF;
101#else
102 return -1;
103#endif
104
105 case _PC_CHOWN_RESTRICTED:
106#ifdef _POSIX_CHOWN_RESTRICTED
107 return _POSIX_CHOWN_RESTRICTED;
108#else
109 return -1;
110#endif
111
112 case _PC_NO_TRUNC:
113#ifdef _POSIX_NO_TRUNC
114 return _POSIX_NO_TRUNC;
115#else
116 return -1;
117#endif
118
119 case _PC_VDISABLE:
120#ifdef _POSIX_VDISABLE
121 return _POSIX_VDISABLE;
122#else
123 return -1;
124#endif
125
126 case _PC_SYNC_IO:
127#ifdef _POSIX_SYNC_IO
128 return _POSIX_SYNC_IO;
129#else
130 return -1;
131#endif
132
133 case _PC_ASYNC_IO:
134#ifdef _POSIX_ASYNC_IO
135 {
136 /* AIO is only allowed on regular files and block devices. */
137 struct stat64 st;
138
139 if (__fxstat64 (_STAT_VER, fd, &st) < 0
140 || (! S_ISREG (st.st_mode) && ! S_ISBLK (st.st_mode)))
141 return -1;
142 else
143 return 1;
144 }
145#else
146 return -1;
147#endif
148
149 case _PC_PRIO_IO:
150#ifdef _POSIX_PRIO_IO
151 return _POSIX_PRIO_IO;
152#else
153 return -1;
154#endif
155
156 case _PC_SOCK_MAXBUF:
157#ifdef SOCK_MAXBUF
158 return SOCK_MAXBUF;
159#else
160 return -1;
161#endif
162
163 case _PC_FILESIZEBITS:
164#ifdef FILESIZEBITS
165 return FILESIZEBITS;
166#else
167 /* We let platforms with larger file sizes overwrite this value. */
168 return 32;
169#endif
170
171 case _PC_REC_INCR_XFER_SIZE:
172 /* XXX It is not entirely clear what the limit is supposed to do.
173 What is incremented? */
174 return -1;
175
176 case _PC_REC_MAX_XFER_SIZE:
177 /* XXX It is not entirely clear what the limit is supposed to do.
178 In general there is no top limit of the number of bytes which
179 case be transported at once. */
180 return -1;
181
182 case _PC_REC_MIN_XFER_SIZE:
183 {
184 /* XXX It is not entirely clear what the limit is supposed to do.
185 I assume this is the block size of the filesystem. */
186 struct statvfs64 sv;
187
188 if (__fstatvfs64 (fd, &sv) < 0)
189 return -1;
190 return sv.f_bsize;
191 }
192
193 case _PC_REC_XFER_ALIGN:
194 {
195 /* XXX It is not entirely clear what the limit is supposed to do.
196 I assume that the number should reflect the minimal block
197 alignment. */
198 struct statvfs64 sv;
199
200 if (__fstatvfs64 (fd, &sv) < 0)
201 return -1;
202 return sv.f_frsize;
203 }
204
205 case _PC_ALLOC_SIZE_MIN:
206 {
207 /* XXX It is not entirely clear what the limit is supposed to do.
208 I assume that the number should reflect the minimal block
209 alignment. */
210 struct statvfs64 sv;
211
212 if (__fstatvfs64 (fd, &sv) < 0)
213 return -1;
214 return sv.f_frsize;
215 }
216
217 case _PC_SYMLINK_MAX:
218 /* In general there are no limits. If a system has one it should
219 overwrite this case. */
220 return -1;
221
222 case _PC_2_SYMLINKS:
223 /* Unix systems generally have symlinks. */
224 return 1;
225 }
226}
227
228#undef __fpathconf
229weak_alias (__fpathconf, fpathconf)
230