1 /*
2 * Copyright (C) 2008 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in
12 * the documentation and/or other materials provided with the
13 * distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <pathconf.h>
30 #include <sys/vfs.h>
31 #include <sys/limits.h>
32 #include <errno.h>
33
34 /* these may not be defined yet by our headers */
35 #ifndef _POSIX_VDISABLE
36 #define _POSIX_VDISABLE -1
37 #endif
38
39 #ifndef _POSIX_SYNC_IO
40 #define _POSIX_SYNC_IO -1
41 #endif
42
43 #ifndef _POSIX_PRIO_IO
44 #define _POSIX_PRIO_IO -1
45 #endif
46
47 #ifndef _POSIX_ASYNC_IO
48 #define _POSIX_ASYNC_IO -1
49 #endif
50
51
52 static long
__filesizebits(struct statfs * s)53 __filesizebits( struct statfs* s )
54 {
55 #define EOL_MAGIC 0x0000U
56
57 /* list of known 64-bit aware filesystems */
58 static const uint32_t known64[] = {
59 EXT2_SUPER_MAGIC,
60 UFS_MAGIC,
61 REISERFS_SUPER_MAGIC,
62 XFS_SUPER_MAGIC,
63 SMB_SUPER_MAGIC,
64 UDF_SUPER_MAGIC,
65 JFS_SUPER_MAGIC,
66 NTFS_SB_MAGIC,
67 VXFS_SUPER_MAGIC,
68 EOL_MAGIC
69 };
70 int nn = 0;
71
72 for (; known64[nn] != EOL_MAGIC; ++nn) {
73 if (known64[nn] == s->f_type) {
74 return 64;
75 }
76 }
77 return 32;
78 }
79
80
81 static long
__link_max(struct statfs * s)82 __link_max( struct statfs* s )
83 {
84 // These constant values were taken from kernel headers.
85 // They're not available in uapi headers.
86 static const struct { uint32_t type; int max; } knownMax[] =
87 {
88 { EXT2_SUPER_MAGIC, 32000 },
89 { EXT3_SUPER_MAGIC, 32000 },
90 { MINIX_SUPER_MAGIC, 250 },
91 { MINIX2_SUPER_MAGIC, 65530 },
92 { REISERFS_SUPER_MAGIC, 0xffff - 1000 },
93 { UFS_MAGIC, 32000 },
94 { EOL_MAGIC, 0 }
95 };
96 int nn = 0;
97
98 for (; knownMax[nn].type != EOL_MAGIC; ++nn) {
99 if (knownMax[nn].type == s->f_type) {
100 return knownMax[nn].max;
101 }
102 }
103 return LINK_MAX;
104 }
105
106 static long
__2_symlinks(struct statfs * s)107 __2_symlinks( struct statfs* s )
108 {
109 /* list of know filesystems that don't support symlinks */
110 static const uint32_t knownNoSymlinks[] = {
111 ADFS_SUPER_MAGIC, BFS_MAGIC, CRAMFS_MAGIC,
112 EFS_SUPER_MAGIC, MSDOS_SUPER_MAGIC, NTFS_SB_MAGIC,
113 QNX4_SUPER_MAGIC,
114 EOL_MAGIC
115 };
116 int nn = 0;
117
118 for (; knownNoSymlinks[nn] != EOL_MAGIC; ++nn) {
119 if (knownNoSymlinks[nn] == s->f_type) {
120 return 0;
121 }
122 }
123 return 1;
124 }
125
126 static long
__name_max(struct statfs * s)127 __name_max( struct statfs* s )
128 {
129 return s->f_namelen;
130 }
131
132 long
pathconf(const char * path,int name)133 pathconf(const char *path, int name)
134 {
135 struct statfs buf;
136 int ret = statfs( path, &buf );
137
138 if (ret < 0)
139 return -1;
140
141 switch (name) {
142 case _PC_FILESIZEBITS:
143 return __filesizebits(&buf);
144
145 case _PC_LINK_MAX:
146 return __link_max(&buf);
147
148 case _PC_MAX_CANON:
149 return MAX_CANON;
150
151 case _PC_MAX_INPUT:
152 return MAX_INPUT;
153
154 case _PC_NAME_MAX:
155 return __name_max(&buf);
156
157 case _PC_PATH_MAX:
158 return PATH_MAX;
159
160 case _PC_PIPE_BUF:
161 return PIPE_BUF;
162
163 case _PC_2_SYMLINKS:
164 return __2_symlinks(&buf);
165
166 #if 0 /* don't know what to do there, the specs are really weird */
167 case _PC_ALLOC_SIZE_MIN:
168 case _PC_REC_INCR_XFER_SIZE:
169 case _PC_REC_MAX_XFER_SIZE:
170 case _PC_REC_MIN_XFER_SIZE:
171 case _PC_REC_XFER_ALIGN:
172 #endif
173
174 case _PC_SYMLINK_MAX:
175 return -1; /* no limit */
176
177 case _PC_CHOWN_RESTRICTED:
178 return _POSIX_CHOWN_RESTRICTED;
179
180 case _PC_NO_TRUNC:
181 return _POSIX_NO_TRUNC;
182
183 case _PC_VDISABLE:
184 return _POSIX_VDISABLE;
185
186 case _PC_ASYNC_IO:
187 return _POSIX_ASYNC_IO;
188
189 case _PC_PRIO_IO:
190 return _POSIX_PRIO_IO;
191
192 case _PC_SYNC_IO:
193 return _POSIX_SYNC_IO;
194
195 default:
196 errno = EINVAL;
197 return -1;
198 }
199 }
200
fpathconf(int fildes,int name)201 long fpathconf(int fildes, int name)
202 {
203 struct statfs buf;
204 int ret = fstatfs(fildes, &buf);
205
206 if (ret < 0)
207 return -1;
208
209 switch (name) {
210 case _PC_FILESIZEBITS:
211 return __filesizebits(&buf);
212
213 case _PC_LINK_MAX:
214 return __link_max(&buf);
215
216 case _PC_MAX_CANON:
217 return MAX_CANON;
218
219 case _PC_MAX_INPUT:
220 return MAX_INPUT;
221
222 case _PC_NAME_MAX:
223 return __name_max(&buf);
224
225 case _PC_PATH_MAX:
226 return PATH_MAX;
227
228 case _PC_PIPE_BUF:
229 return PIPE_BUF;
230
231 case _PC_2_SYMLINKS:
232 return __2_symlinks(&buf);
233
234 #if 0 /* don't know what to do there, the specs are really weird */
235 case _PC_ALLOC_SIZE_MIN:
236 case _PC_REC_INCR_XFER_SIZE:
237 case _PC_REC_MAX_XFER_SIZE:
238 case _PC_REC_MIN_XFER_SIZE:
239 case _PC_REC_XFER_ALIGN:
240 #endif
241
242 case _PC_SYMLINK_MAX:
243 return -1; /* no limit */
244
245 case _PC_CHOWN_RESTRICTED:
246 return _POSIX_CHOWN_RESTRICTED;
247
248 case _PC_NO_TRUNC:
249 return _POSIX_NO_TRUNC;
250
251 case _PC_VDISABLE:
252 return _POSIX_VDISABLE;
253
254 case _PC_ASYNC_IO:
255 return _POSIX_ASYNC_IO;
256
257 case _PC_PRIO_IO:
258 return _POSIX_PRIO_IO;
259
260 case _PC_SYNC_IO:
261 return _POSIX_SYNC_IO;
262
263 default:
264 errno = EINVAL;
265 return -1;
266 }
267 }
268