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 <unistd.h>
30
31 #include <errno.h>
32 #include <sys/limits.h>
33 #include <sys/vfs.h>
34
__filesizebits(const struct statfs & s)35 static long __filesizebits(const struct statfs& s) {
36 switch (s.f_type) {
37 case JFFS2_SUPER_MAGIC:
38 case MSDOS_SUPER_MAGIC:
39 case NCP_SUPER_MAGIC:
40 return 32;
41 }
42 // There won't be any new 32-bit file systems.
43 return 64;
44 }
45
__link_max(const struct statfs & s)46 static long __link_max(const struct statfs& s) {
47 // These constant values were taken from kernel headers.
48 // They're not available in uapi headers.
49 switch (s.f_type) {
50 case EXT2_SUPER_MAGIC:
51 return 32000;
52 case MINIX_SUPER_MAGIC:
53 return 250;
54 case MINIX2_SUPER_MAGIC:
55 return 65530;
56 case REISERFS_SUPER_MAGIC:
57 return 0xffff - 1000;
58 case UFS_MAGIC:
59 return 32000;
60 }
61 return LINK_MAX;
62 }
63
__2_symlinks(const struct statfs & s)64 static long __2_symlinks(const struct statfs& s) {
65 switch (s.f_type) {
66 case ADFS_SUPER_MAGIC:
67 case BFS_MAGIC:
68 case CRAMFS_MAGIC:
69 case EFS_SUPER_MAGIC:
70 case MSDOS_SUPER_MAGIC:
71 case QNX4_SUPER_MAGIC:
72 return 0;
73 }
74 return 1;
75 }
76
__pathconf(const struct statfs & s,int name)77 static long __pathconf(const struct statfs& s, int name) {
78 switch (name) {
79 case _PC_FILESIZEBITS:
80 return __filesizebits(s);
81
82 case _PC_LINK_MAX:
83 return __link_max(s);
84
85 case _PC_MAX_CANON:
86 return MAX_CANON;
87
88 case _PC_MAX_INPUT:
89 return MAX_INPUT;
90
91 case _PC_NAME_MAX:
92 return s.f_namelen;
93
94 case _PC_PATH_MAX:
95 return PATH_MAX;
96
97 case _PC_PIPE_BUF:
98 return PIPE_BUF;
99
100 case _PC_2_SYMLINKS:
101 return __2_symlinks(s);
102
103 case _PC_ALLOC_SIZE_MIN: /* fall through */
104 case _PC_REC_XFER_ALIGN:
105 return s.f_frsize;
106
107 case _PC_REC_MIN_XFER_SIZE:
108 return s.f_bsize;
109
110 #if 0
111 case _PC_REC_INCR_XFER_SIZE:
112 case _PC_REC_MAX_XFER_SIZE:
113 #endif
114
115 case _PC_SYMLINK_MAX:
116 return -1; /* no limit */
117
118 case _PC_CHOWN_RESTRICTED:
119 return _POSIX_CHOWN_RESTRICTED;
120
121 case _PC_NO_TRUNC:
122 return _POSIX_NO_TRUNC;
123
124 case _PC_VDISABLE:
125 return _POSIX_VDISABLE;
126
127 case _PC_ASYNC_IO:
128 return -1;
129
130 case _PC_PRIO_IO:
131 return -1;
132
133 case _PC_SYNC_IO:
134 return -1;
135
136 default:
137 errno = EINVAL;
138 return -1;
139 }
140 }
141
pathconf(const char * path,int name)142 long pathconf(const char* path, int name) {
143 struct statfs sb;
144 if (statfs(path, &sb) == -1) {
145 return -1;
146 }
147 return __pathconf(sb, name);
148 }
149
fpathconf(int fd,int name)150 long fpathconf(int fd, int name) {
151 struct statfs sb;
152 if (fstatfs(fd, &sb) == -1) {
153 return -1;
154 }
155 return __pathconf(sb, name);
156 }
157