1//===-- Linux implementation of pathconf_utils ----------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9// This header must go before limits_macros.h otherwise libc header may choose
10// to undefine LINK_MAX.
11#include <linux/limits.h> // For LINK_MAX and other limits
12
13#include "hdr/limits_macros.h"
14#include "hdr/unistd_macros.h"
15#include "src/__support/OSUtil/syscall.h" // For internal syscall function.
16#include "src/__support/common.h"
17#include "src/__support/libc_errno.h"
18#include "src/__support/macros/config.h"
19#include "src/sys/statvfs/linux/statfs_utils.h"
20
21// other linux specific includes
22#include <linux/bfs_fs.h>
23#if __has_include(<linux/ufs_fs.h>)
24#include <linux/ufs_fs.h>
25#else
26// from https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/
27#define UFS_MAGIC 0x00011954
28#endif
29#include <linux/magic.h> // For common FS magics
30
31namespace LIBC_NAMESPACE_DECL {
32
33long filesizebits(const statfs_utils::LinuxStatFs &s) {
34 switch (s.f_type) {
35 case JFFS2_SUPER_MAGIC:
36 case MSDOS_SUPER_MAGIC:
37 case NCP_SUPER_MAGIC:
38 return 32;
39 }
40 return 64;
41}
42
43long link_max(const statfs_utils::LinuxStatFs &s) {
44 switch (s.f_type) {
45 case EXT2_SUPER_MAGIC:
46 return 32000;
47 case MINIX_SUPER_MAGIC:
48 return 250;
49 case MINIX2_SUPER_MAGIC:
50 return 65530;
51 case REISERFS_SUPER_MAGIC:
52 return 0xffff - 1000;
53 case UFS_MAGIC:
54 return 32000;
55 }
56 return LINK_MAX;
57}
58
59long symlinks(const statfs_utils::LinuxStatFs &s) {
60 switch (s.f_type) {
61 case ADFS_SUPER_MAGIC:
62 case BFS_MAGIC:
63 case CRAMFS_MAGIC:
64 case EFS_SUPER_MAGIC:
65 case MSDOS_SUPER_MAGIC:
66 case QNX4_SUPER_MAGIC:
67 return 0;
68 }
69 return 1;
70}
71
72long pathconfig(const statfs_utils::LinuxStatFs &s, int name) {
73 switch (name) {
74 case _PC_LINK_MAX:
75 return link_max(s);
76
77 case _PC_FILESIZEBITS:
78 return filesizebits(s);
79
80 case _PC_2_SYMLINKS:
81 return symlinks(s);
82
83 case _PC_REC_MIN_XFER_SIZE:
84 return s.f_bsize;
85
86 case _PC_ALLOC_SIZE_MIN:
87 case _PC_REC_XFER_ALIGN:
88 return s.f_frsize;
89
90 case _PC_MAX_CANON:
91 return _POSIX_MAX_CANON;
92
93 case _PC_MAX_INPUT:
94 return _POSIX_MAX_INPUT;
95
96 case _PC_NAME_MAX:
97 return s.f_namelen;
98
99 case _PC_PATH_MAX:
100 return _POSIX_PATH_MAX;
101
102 case _PC_PIPE_BUF:
103 return _POSIX_PIPE_BUF;
104
105 case _PC_CHOWN_RESTRICTED:
106 return _POSIX_CHOWN_RESTRICTED;
107
108 case _PC_NO_TRUNC:
109 return _POSIX_NO_TRUNC;
110
111 case _PC_VDISABLE:
112 return _POSIX_VDISABLE;
113
114 case _PC_ASYNC_IO:
115 case _PC_PRIO_IO:
116 case _PC_REC_INCR_XFER_SIZE:
117 case _PC_REC_MAX_XFER_SIZE:
118 case _PC_SYMLINK_MAX:
119 case _PC_SYNC_IO:
120 return -1;
121
122 default:
123 libc_errno = EINVAL;
124 return -1;
125 }
126}
127
128} // namespace LIBC_NAMESPACE_DECL
129

source code of libc/src/unistd/linux/pathconf_utils.cpp