jcs.org
Serenity Operating System
1/*
2 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
3 *
4 * SPDX-License-Identifier: BSD-2-Clause
5 */
6
7#pragma once
8
9#include <AK/Error.h>
10#include <AK/Span.h>
11#include <AK/Time.h>
12#include <Kernel/FileSystem/DeviceFileTypes.h>
13#include <Kernel/FileSystem/InodeIdentifier.h>
14#include <Kernel/Forward.h>
15#include <Kernel/UnixTypes.h>
16
17namespace Kernel {
18
19class Process;
20
21constexpr u64 encoded_device(MajorNumber major, MinorNumber minor)
22{
23 return (minor.value() & 0xff) | (major.value() << 8) | ((minor.value() & ~0xff) << 12);
24}
25static inline MajorNumber major_from_encoded_device(dev_t dev) { return (dev & 0xfff00u) >> 8u; }
26static inline MinorNumber minor_from_encoded_device(dev_t dev) { return (dev & 0xffu) | ((dev >> 12u) & 0xfff00u); }
27
28inline bool is_directory(mode_t mode) { return (mode & S_IFMT) == S_IFDIR; }
29inline bool is_character_device(mode_t mode) { return (mode & S_IFMT) == S_IFCHR; }
30inline bool is_block_device(mode_t mode) { return (mode & S_IFMT) == S_IFBLK; }
31inline bool is_regular_file(mode_t mode) { return (mode & S_IFMT) == S_IFREG; }
32inline bool is_fifo(mode_t mode) { return (mode & S_IFMT) == S_IFIFO; }
33inline bool is_symlink(mode_t mode) { return (mode & S_IFMT) == S_IFLNK; }
34inline bool is_socket(mode_t mode) { return (mode & S_IFMT) == S_IFSOCK; }
35inline bool is_sticky(mode_t mode) { return (mode & S_ISVTX) == S_ISVTX; }
36inline bool is_setuid(mode_t mode) { return (mode & S_ISUID) == S_ISUID; }
37inline bool is_setgid(mode_t mode) { return (mode & S_ISGID) == S_ISGID; }
38
39enum class UseEffectiveIDs {
40 Yes,
41 No
42};
43
44struct InodeMetadata {
45 bool is_valid() const { return inode.is_valid(); }
46
47 bool may_read(Credentials const&, UseEffectiveIDs = UseEffectiveIDs::Yes) const;
48 bool may_write(Credentials const&, UseEffectiveIDs = UseEffectiveIDs::Yes) const;
49 bool may_execute(Credentials const&, UseEffectiveIDs = UseEffectiveIDs::Yes) const;
50
51 bool may_read(UserID u, GroupID g, ReadonlySpan<GroupID> eg) const
52 {
53 if (u == 0)
54 return true;
55 if (uid == u)
56 return (mode & S_IRUSR) == S_IRUSR;
57 if (gid == g || eg.contains_slow(gid))
58 return (mode & S_IRGRP) == S_IRGRP;
59 return (mode & S_IROTH) == S_IROTH;
60 }
61
62 bool may_write(UserID u, GroupID g, ReadonlySpan<GroupID> eg) const
63 {
64 if (u == 0)
65 return true;
66 if (uid == u)
67 return (mode & S_IWUSR) == S_IWUSR;
68 if (gid == g || eg.contains_slow(gid))
69 return (mode & S_IWGRP) == S_IWGRP;
70 return (mode & S_IWOTH) == S_IWOTH;
71 }
72
73 bool may_execute(UserID u, GroupID g, ReadonlySpan<GroupID> eg) const
74 {
75 if (u == 0)
76 return true;
77 if (uid == u)
78 return (mode & S_IXUSR) == S_IXUSR;
79 if (gid == g || eg.contains_slow(gid))
80 return (mode & S_IXGRP) == S_IXGRP;
81 return (mode & S_IXOTH) == S_IXOTH;
82 }
83
84 bool is_directory() const { return Kernel::is_directory(mode); }
85 bool is_character_device() const { return Kernel::is_character_device(mode); }
86 bool is_block_device() const { return Kernel::is_block_device(mode); }
87 bool is_device() const { return is_character_device() || is_block_device(); }
88 bool is_regular_file() const { return Kernel::is_regular_file(mode); }
89 bool is_fifo() const { return Kernel::is_fifo(mode); }
90 bool is_symlink() const { return Kernel::is_symlink(mode); }
91 bool is_socket() const { return Kernel::is_socket(mode); }
92 bool is_sticky() const { return Kernel::is_sticky(mode); }
93 bool is_setuid() const { return Kernel::is_setuid(mode); }
94 bool is_setgid() const { return Kernel::is_setgid(mode); }
95
96 ErrorOr<struct stat> stat() const
97 {
98 if (!is_valid())
99 return EIO;
100 struct stat buffer = {};
101 buffer.st_rdev = encoded_device(major_device, minor_device);
102 buffer.st_ino = inode.index().value();
103 buffer.st_mode = mode;
104 buffer.st_nlink = link_count;
105 buffer.st_uid = uid.value();
106 buffer.st_gid = gid.value();
107 buffer.st_dev = 0; // FIXME
108 buffer.st_size = size;
109 buffer.st_blksize = block_size;
110 buffer.st_blocks = block_count;
111 buffer.st_atim = atime.to_timespec();
112 buffer.st_mtim = mtime.to_timespec();
113 buffer.st_ctim = ctime.to_timespec();
114 return buffer;
115 }
116
117 InodeIdentifier inode;
118 off_t size { 0 };
119 mode_t mode { 0 };
120 UserID uid { 0 };
121 GroupID gid { 0 };
122 nlink_t link_count { 0 };
123 Time atime {};
124 Time ctime {};
125 Time mtime {};
126 Time dtime {};
127 blkcnt_t block_count { 0 };
128 blksize_t block_size { 0 };
129 MajorNumber major_device { 0 };
130 MinorNumber minor_device { 0 };
131};
132
133}