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Serenity Operating System
1/*
2 * Copyright (c) 2019-2020, Sergey Bugaev <bugaevc@serenityos.org>
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 are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice, this
9 * list of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright notice,
12 * this list of conditions and the following disclaimer in the documentation
13 * and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
22 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
23 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include <AK/StringBuilder.h>
28#include <AK/StringView.h>
29#include <Kernel/FileSystem/DevPtsFS.h>
30#include <Kernel/FileSystem/VirtualFileSystem.h>
31#include <Kernel/TTY/SlavePTY.h>
32
33namespace Kernel {
34
35NonnullRefPtr<DevPtsFS> DevPtsFS::create()
36{
37 return adopt(*new DevPtsFS);
38}
39
40DevPtsFS::DevPtsFS()
41{
42}
43
44DevPtsFS::~DevPtsFS()
45{
46}
47
48static HashTable<unsigned>* ptys;
49
50bool DevPtsFS::initialize()
51{
52 if (ptys == nullptr) {
53 ptys = new HashTable<unsigned>();
54 }
55
56 m_root_inode = adopt(*new DevPtsFSInode(*this, 1));
57 m_root_inode->m_metadata.inode = { fsid(), 1 };
58 m_root_inode->m_metadata.mode = 0040555;
59 m_root_inode->m_metadata.uid = 0;
60 m_root_inode->m_metadata.gid = 0;
61 m_root_inode->m_metadata.size = 0;
62 m_root_inode->m_metadata.mtime = mepoch;
63
64 return true;
65}
66
67static unsigned inode_index_to_pty_index(unsigned inode_index)
68{
69 ASSERT(inode_index > 1);
70 return inode_index - 2;
71}
72
73static unsigned pty_index_to_inode_index(unsigned pty_index)
74{
75 return pty_index + 2;
76}
77
78InodeIdentifier DevPtsFS::root_inode() const
79{
80 return { fsid(), 1 };
81}
82
83KResultOr<NonnullRefPtr<Inode>> DevPtsFS::create_inode(InodeIdentifier, const String&, mode_t, off_t, dev_t, uid_t, gid_t)
84{
85 return KResult(-EROFS);
86}
87
88KResult DevPtsFS::create_directory(InodeIdentifier, const String&, mode_t, uid_t, gid_t)
89{
90 return KResult(-EROFS);
91}
92
93RefPtr<Inode> DevPtsFS::get_inode(InodeIdentifier inode_id) const
94{
95 if (inode_id.index() == 1)
96 return m_root_inode;
97
98 unsigned pty_index = inode_index_to_pty_index(inode_id.index());
99 auto* device = Device::get_device(201, pty_index);
100 ASSERT(device);
101
102 auto inode = adopt(*new DevPtsFSInode(const_cast<DevPtsFS&>(*this), inode_id.index()));
103 inode->m_metadata.inode = inode_id;
104 inode->m_metadata.size = 0;
105 inode->m_metadata.uid = device->uid();
106 inode->m_metadata.gid = device->gid();
107 inode->m_metadata.mode = 0020600;
108 inode->m_metadata.major_device = device->major();
109 inode->m_metadata.minor_device = device->minor();
110 inode->m_metadata.mtime = mepoch;
111
112 return inode;
113}
114
115void DevPtsFS::register_slave_pty(SlavePTY& slave_pty)
116{
117 ptys->set(slave_pty.index());
118}
119
120void DevPtsFS::unregister_slave_pty(SlavePTY& slave_pty)
121{
122 ptys->remove(slave_pty.index());
123}
124
125DevPtsFSInode::DevPtsFSInode(DevPtsFS& fs, unsigned index)
126 : Inode(fs, index)
127{
128}
129
130DevPtsFSInode::~DevPtsFSInode()
131{
132}
133
134ssize_t DevPtsFSInode::read_bytes(off_t, ssize_t, u8*, FileDescription*) const
135{
136 ASSERT_NOT_REACHED();
137}
138
139ssize_t DevPtsFSInode::write_bytes(off_t, ssize_t, const u8*, FileDescription*)
140{
141 ASSERT_NOT_REACHED();
142}
143
144InodeMetadata DevPtsFSInode::metadata() const
145{
146 return m_metadata;
147}
148
149bool DevPtsFSInode::traverse_as_directory(Function<bool(const FS::DirectoryEntry&)> callback) const
150{
151 if (identifier().index() > 1)
152 return false;
153
154 callback({ ".", 1, identifier(), 0 });
155 callback({ "..", 2, identifier(), 0 });
156
157 for (unsigned pty_index : *ptys) {
158 String name = String::number(pty_index);
159 InodeIdentifier identifier = { fsid(), pty_index_to_inode_index(pty_index) };
160 callback({ name.characters(), name.length(), identifier, 0 });
161 }
162
163 return true;
164}
165
166size_t DevPtsFSInode::directory_entry_count() const
167{
168 ASSERT(identifier().index() == 1);
169
170 return 2 + ptys->size();
171}
172
173RefPtr<Inode> DevPtsFSInode::lookup(StringView name)
174{
175 ASSERT(identifier().index() == 1);
176
177 if (name == "." || name == "..")
178 return fs().get_inode(identifier());
179
180 bool ok;
181 unsigned pty_index = name.to_uint(ok);
182 if (ok && ptys->contains(pty_index)) {
183 return fs().get_inode({ fsid(), pty_index_to_inode_index(pty_index) });
184 }
185
186 return {};
187}
188
189void DevPtsFSInode::flush_metadata()
190{
191}
192
193KResult DevPtsFSInode::add_child(InodeIdentifier, const StringView&, mode_t)
194{
195 return KResult(-EROFS);
196}
197
198KResult DevPtsFSInode::remove_child(const StringView&)
199{
200 return KResult(-EROFS);
201}
202
203KResult DevPtsFSInode::chmod(mode_t)
204{
205 return KResult(-EPERM);
206}
207
208KResult DevPtsFSInode::chown(uid_t, gid_t)
209{
210 return KResult(-EPERM);
211}
212
213}