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/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include "Client.h"
#include <AK/ByteBuffer.h>
#include <AK/MemoryStream.h>
#include <AK/String.h>
#include <AK/StringBuilder.h>
#include <AK/StringView.h>
#include <AK/Types.h>
#include <LibCore/EventLoop.h>
#include <LibCore/Notifier.h>
#include <stdio.h>
#include <unistd.h>
Client::Client(int id, NonnullOwnPtr<Core::Stream::TCPSocket> socket, int ptm_fd)
: m_id(id)
, m_socket(move(socket))
, m_ptm_fd(ptm_fd)
, m_ptm_notifier(Core::Notifier::construct(ptm_fd, Core::Notifier::Read))
{
m_socket->on_ready_to_read = [this] {
auto result = drain_socket();
if (result.is_error()) {
dbgln("Failed to drain the socket: {}", result.error());
Core::deferred_invoke([this, strong_this = NonnullRefPtr(*this)] { quit(); });
}
};
m_ptm_notifier->on_ready_to_read = [this] {
auto result = drain_pty();
if (result.is_error()) {
dbgln("Failed to drain the PTY: {}", result.error());
Core::deferred_invoke([this, strong_this = NonnullRefPtr(*this)] { quit(); });
}
};
m_parser.on_command = [this](const Command& command) {
auto result = handle_command(command);
if (result.is_error()) {
dbgln("Failed to handle the command: {}", result.error());
Core::deferred_invoke([this, strong_this = NonnullRefPtr(*this)] { quit(); });
}
};
m_parser.on_data = [this](StringView data) { handle_data(data); };
m_parser.on_error = [this]() { handle_error(); };
}
ErrorOr<NonnullRefPtr<Client>> Client::create(int id, NonnullOwnPtr<Core::Stream::TCPSocket> socket, int ptm_fd)
{
auto client = adopt_ref(*new Client(id, move(socket), ptm_fd));
auto result = client->send_commands({
{ CMD_WILL, SUB_SUPPRESS_GO_AHEAD },
{ CMD_WILL, SUB_ECHO },
{ CMD_DO, SUB_SUPPRESS_GO_AHEAD },
{ CMD_DONT, SUB_ECHO },
});
if (result.is_error()) {
client->quit();
return result.release_error();
}
return client;
}
ErrorOr<void> Client::drain_socket()
{
NonnullRefPtr<Client> protect(*this);
auto buffer = TRY(ByteBuffer::create_uninitialized(1024));
while (TRY(m_socket->can_read_without_blocking())) {
auto nread = TRY(m_socket->read(buffer));
m_parser.write({ buffer.data(), nread });
if (m_socket->is_eof()) {
Core::deferred_invoke([this, strong_this = NonnullRefPtr(*this)] { quit(); });
break;
}
}
return {};
}
ErrorOr<void> Client::drain_pty()
{
u8 buffer[BUFSIZ];
ssize_t nread = read(m_ptm_fd, buffer, sizeof(buffer));
if (nread < 0) {
Core::deferred_invoke([this, strong_this = NonnullRefPtr(*this)] { quit(); });
return static_cast<ErrnoCode>(errno);
}
if (nread == 0) {
Core::deferred_invoke([this, strong_this = NonnullRefPtr(*this)] { quit(); });
return {};
}
return send_data({ buffer, (size_t)nread });
}
void Client::handle_data(StringView data)
{
write(m_ptm_fd, data.characters_without_null_termination(), data.length());
}
ErrorOr<void> Client::handle_command(const Command& command)
{
switch (command.command) {
case CMD_DO:
// no response - we've already advertised our options, and none of
// them can be disabled (or re-enabled) after connecting.
break;
case CMD_DONT:
// no response - we only "support" two options (echo and suppress
// go-ahead), and both of them are always enabled.
break;
case CMD_WILL:
switch (command.subcommand) {
case SUB_ECHO:
// we always want to be the ones in control of the output. tell
// the client to disable local echo.
TRY(send_command({ CMD_DONT, SUB_ECHO }));
break;
case SUB_SUPPRESS_GO_AHEAD:
TRY(send_command({ CMD_DO, SUB_SUPPRESS_GO_AHEAD }));
break;
default:
// don't respond to unknown commands
break;
}
break;
case CMD_WONT:
// no response - we don't care about anything the client says they
// won't do.
break;
}
return {};
}
void Client::handle_error()
{
Core::deferred_invoke([this, strong_this = NonnullRefPtr(*this)] { quit(); });
}
ErrorOr<void> Client::send_data(StringView data)
{
bool fast = true;
for (size_t i = 0; i < data.length(); i++) {
u8 c = data[i];
if (c == '\n' || c == 0xff)
fast = false;
}
if (fast) {
TRY(m_socket->write({ data.characters_without_null_termination(), data.length() }));
return {};
}
StringBuilder builder;
for (size_t i = 0; i < data.length(); i++) {
u8 c = data[i];
switch (c) {
case '\n':
builder.append("\r\n");
break;
case IAC:
builder.append("\xff\xff");
break;
default:
builder.append(c);
break;
}
}
auto builder_contents = builder.to_byte_buffer();
TRY(m_socket->write(builder_contents));
return {};
}
ErrorOr<void> Client::send_command(Command command)
{
return send_commands({ command });
}
ErrorOr<void> Client::send_commands(Vector<Command> commands)
{
auto buffer = TRY(ByteBuffer::create_uninitialized(commands.size() * 3));
OutputMemoryStream stream { buffer };
for (auto& command : commands)
stream << (u8)IAC << command.command << command.subcommand;
VERIFY(stream.is_end());
TRY(m_socket->write({ buffer.data(), buffer.size() }));
return {};
}
void Client::quit()
{
m_ptm_notifier->set_enabled(false);
close(m_ptm_fd);
m_socket->close();
if (on_exit)
on_exit();
}
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