LadybirdBrowser/ladybird
1
1
Fork 0
mirror of https://github.com/LadybirdBrowser/ladybird.git synced 2024-11-11 01:06:01 +03:00
Code Issues Packages Projects Releases Wiki Activity
8f0a48ef23
ladybird/Kernel/Net/TCPSocket.cpp
Andreas Kling 11eee67b85 Kernel: Make self-contained locking smart pointers their own classes 
Until now, our kernel has reimplemented a number of AK classes to
provide automatic internal locking:

- RefPtr
- NonnullRefPtr
- WeakPtr
- Weakable

This patch renames the Kernel classes so that they can coexist with
the original AK classes:

- RefPtr => LockRefPtr
- NonnullRefPtr => NonnullLockRefPtr
- WeakPtr => LockWeakPtr
- Weakable => LockWeakable

The goal here is to eventually get rid of the Lock* classes in favor of
using external locking.
2022-08-20 17:20:43 +02:00

642 lines
23 KiB
C++
Raw Blame History

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Singleton.h>
#include <AK/Time.h>
#include <Kernel/Debug.h>
#include <Kernel/Devices/RandomDevice.h>
#include <Kernel/FileSystem/OpenFileDescription.h>
#include <Kernel/Locking/MutexProtected.h>
#include <Kernel/Net/EthernetFrameHeader.h>
#include <Kernel/Net/IPv4.h>
#include <Kernel/Net/NetworkAdapter.h>
#include <Kernel/Net/NetworkingManagement.h>
#include <Kernel/Net/Routing.h>
#include <Kernel/Net/TCP.h>
#include <Kernel/Net/TCPSocket.h>
#include <Kernel/Process.h>
#include <Kernel/Random.h>
namespace Kernel {
void TCPSocket::for_each(Function<void(TCPSocket const&)> callback)
{
sockets_by_tuple().for_each_shared([&](auto const& it) {
callback(*it.value);
});
}
ErrorOr<void> TCPSocket::try_for_each(Function<ErrorOr<void>(TCPSocket const&)> callback)
{
return sockets_by_tuple().with_shared([&](auto const& sockets) -> ErrorOr<void> {
for (auto& it : sockets)
TRY(callback(*it.value));
return {};
});
}
bool TCPSocket::unref() const
{
bool did_hit_zero = sockets_by_tuple().with_exclusive([&](auto& table) {
if (deref_base())
return false;
table.remove(tuple());
const_cast<TCPSocket&>(*this).revoke_weak_ptrs();
return true;
});
if (did_hit_zero) {
const_cast<TCPSocket&>(*this).will_be_destroyed();
delete this;
}
return did_hit_zero;
}
void TCPSocket::set_state(State new_state)
{
dbgln_if(TCP_SOCKET_DEBUG, "TCPSocket({}) state moving from {} to {}", this, to_string(m_state), to_string(new_state));
auto was_disconnected = protocol_is_disconnected();
auto previous_role = m_role;
m_state = new_state;
if (new_state == State::Established && m_direction == Direction::Outgoing) {
set_role(Role::Connected);
clear_so_error();
}
if (new_state == State::TimeWait) {
// Once we hit TimeWait, we are only holding the socket in case there
// are packets on the way which we wouldn't want a new socket to get hit
// with, so there's no point in keeping the receive buffer around.
drop_receive_buffer();
}
if (new_state == State::Closed) {
closing_sockets().with_exclusive([&](auto& table) {
table.remove(tuple());
});
if (m_originator)
release_to_originator();
}
if (previous_role != m_role || was_disconnected != protocol_is_disconnected())
evaluate_block_conditions();
}
static Singleton<MutexProtected<HashMap<IPv4SocketTuple, LockRefPtr<TCPSocket>>>> s_socket_closing;
MutexProtected<HashMap<IPv4SocketTuple, LockRefPtr<TCPSocket>>>& TCPSocket::closing_sockets()
{
return *s_socket_closing;
}
static Singleton<MutexProtected<HashMap<IPv4SocketTuple, TCPSocket*>>> s_socket_tuples;
MutexProtected<HashMap<IPv4SocketTuple, TCPSocket*>>& TCPSocket::sockets_by_tuple()
{
return *s_socket_tuples;
}
LockRefPtr<TCPSocket> TCPSocket::from_tuple(IPv4SocketTuple const& tuple)
{
return sockets_by_tuple().with_shared([&](auto const& table) -> LockRefPtr<TCPSocket> {
auto exact_match = table.get(tuple);
if (exact_match.has_value())
return { *exact_match.value() };
auto address_tuple = IPv4SocketTuple(tuple.local_address(), tuple.local_port(), IPv4Address(), 0);
auto address_match = table.get(address_tuple);
if (address_match.has_value())
return { *address_match.value() };
auto wildcard_tuple = IPv4SocketTuple(IPv4Address(), tuple.local_port(), IPv4Address(), 0);
auto wildcard_match = table.get(wildcard_tuple);
if (wildcard_match.has_value())
return { *wildcard_match.value() };
return {};
});
}
ErrorOr<NonnullLockRefPtr<TCPSocket>> TCPSocket::try_create_client(IPv4Address const& new_local_address, u16 new_local_port, IPv4Address const& new_peer_address, u16 new_peer_port)
{
auto tuple = IPv4SocketTuple(new_local_address, new_local_port, new_peer_address, new_peer_port);
return sockets_by_tuple().with_exclusive([&](auto& table) -> ErrorOr<NonnullLockRefPtr<TCPSocket>> {
if (table.contains(tuple))
return EEXIST;
auto receive_buffer = TRY(try_create_receive_buffer());
auto client = TRY(TCPSocket::try_create(protocol(), move(receive_buffer)));
client->set_setup_state(SetupState::InProgress);
client->set_local_address(new_local_address);
client->set_local_port(new_local_port);
client->set_peer_address(new_peer_address);
client->set_peer_port(new_peer_port);
client->set_direction(Direction::Incoming);
client->set_originator(*this);
m_pending_release_for_accept.set(tuple, client);
table.set(tuple, client);
return { move(client) };
});
}
void TCPSocket::release_to_originator()
{
VERIFY(!!m_originator);
m_originator.strong_ref()->release_for_accept(*this);
m_originator.clear();
}
void TCPSocket::release_for_accept(NonnullLockRefPtr<TCPSocket> socket)
{
VERIFY(m_pending_release_for_accept.contains(socket->tuple()));
m_pending_release_for_accept.remove(socket->tuple());
// FIXME: Should we observe this error somehow?
[[maybe_unused]] auto rc = queue_connection_from(move(socket));
}
TCPSocket::TCPSocket(int protocol, NonnullOwnPtr<DoubleBuffer> receive_buffer, NonnullOwnPtr<KBuffer> scratch_buffer)
: IPv4Socket(SOCK_STREAM, protocol, move(receive_buffer), move(scratch_buffer))
{
m_last_retransmit_time = kgettimeofday();
}
TCPSocket::~TCPSocket()
{
dequeue_for_retransmit();
dbgln_if(TCP_SOCKET_DEBUG, "~TCPSocket in state {}", to_string(state()));
}
ErrorOr<NonnullLockRefPtr<TCPSocket>> TCPSocket::try_create(int protocol, NonnullOwnPtr<DoubleBuffer> receive_buffer)
{
// Note: Scratch buffer is only used for SOCK_STREAM sockets.
auto scratch_buffer = TRY(KBuffer::try_create_with_size("TCPSocket: Scratch buffer"sv, 65536));
return adopt_nonnull_lock_ref_or_enomem(new (nothrow) TCPSocket(protocol, move(receive_buffer), move(scratch_buffer)));
}
ErrorOr<size_t> TCPSocket::protocol_size(ReadonlyBytes raw_ipv4_packet)
{
auto& ipv4_packet = *reinterpret_cast<IPv4Packet const*>(raw_ipv4_packet.data());
auto& tcp_packet = *static_cast<TCPPacket const*>(ipv4_packet.payload());
return raw_ipv4_packet.size() - sizeof(IPv4Packet) - tcp_packet.header_size();
}
ErrorOr<size_t> TCPSocket::protocol_receive(ReadonlyBytes raw_ipv4_packet, UserOrKernelBuffer& buffer, size_t buffer_size, [[maybe_unused]] int flags)
{
auto& ipv4_packet = *reinterpret_cast<IPv4Packet const*>(raw_ipv4_packet.data());
auto& tcp_packet = *static_cast<TCPPacket const*>(ipv4_packet.payload());
size_t payload_size = raw_ipv4_packet.size() - sizeof(IPv4Packet) - tcp_packet.header_size();
dbgln_if(TCP_SOCKET_DEBUG, "payload_size {}, will it fit in {}?", payload_size, buffer_size);
VERIFY(buffer_size >= payload_size);
SOCKET_TRY(buffer.write(tcp_packet.payload(), payload_size));
return payload_size;
}
ErrorOr<size_t> TCPSocket::protocol_send(UserOrKernelBuffer const& data, size_t data_length)
{
RoutingDecision routing_decision = route_to(peer_address(), local_address(), bound_interface());
if (routing_decision.is_zero())
return set_so_error(EHOSTUNREACH);
size_t mss = routing_decision.adapter->mtu() - sizeof(IPv4Packet) - sizeof(TCPPacket);
data_length = min(data_length, mss);
TRY(send_tcp_packet(TCPFlags::PSH | TCPFlags::ACK, &data, data_length, &routing_decision));
return data_length;
}
ErrorOr<void> TCPSocket::send_ack(bool allow_duplicate)
{
if (!allow_duplicate && m_last_ack_number_sent == m_ack_number)
return {};
return send_tcp_packet(TCPFlags::ACK);
}
ErrorOr<void> TCPSocket::send_tcp_packet(u16 flags, UserOrKernelBuffer const* payload, size_t payload_size, RoutingDecision* user_routing_decision)
{
RoutingDecision routing_decision = user_routing_decision ? *user_routing_decision : route_to(peer_address(), local_address(), bound_interface());
if (routing_decision.is_zero())
return set_so_error(EHOSTUNREACH);
auto ipv4_payload_offset = routing_decision.adapter->ipv4_payload_offset();
bool const has_mss_option = flags == TCPFlags::SYN;
const size_t options_size = has_mss_option ? sizeof(TCPOptionMSS) : 0;
const size_t tcp_header_size = sizeof(TCPPacket) + options_size;
const size_t buffer_size = ipv4_payload_offset + tcp_header_size + payload_size;
auto packet = routing_decision.adapter->acquire_packet_buffer(buffer_size);
if (!packet)
return set_so_error(ENOMEM);
routing_decision.adapter->fill_in_ipv4_header(*packet, local_address(),
routing_decision.next_hop, peer_address(), IPv4Protocol::TCP,
buffer_size - ipv4_payload_offset, type_of_service(), ttl());
memset(packet->buffer->data() + ipv4_payload_offset, 0, sizeof(TCPPacket));
auto& tcp_packet = *(TCPPacket*)(packet->buffer->data() + ipv4_payload_offset);
VERIFY(local_port());
tcp_packet.set_source_port(local_port());
tcp_packet.set_destination_port(peer_port());
tcp_packet.set_window_size(NumericLimits<u16>::max());
tcp_packet.set_sequence_number(m_sequence_number);
tcp_packet.set_data_offset(tcp_header_size / sizeof(u32));
tcp_packet.set_flags(flags);
if (payload) {
if (auto result = payload->read(tcp_packet.payload(), payload_size); result.is_error()) {
routing_decision.adapter->release_packet_buffer(*packet);
return set_so_error(result.release_error());
}
}
if (flags & TCPFlags::ACK) {
m_last_ack_number_sent = m_ack_number;
m_last_ack_sent_time = kgettimeofday();
tcp_packet.set_ack_number(m_ack_number);
}
if (flags & TCPFlags::SYN) {
++m_sequence_number;
} else {
m_sequence_number += payload_size;
}
if (has_mss_option) {
u16 mss = routing_decision.adapter->mtu() - sizeof(IPv4Packet) - sizeof(TCPPacket);
TCPOptionMSS mss_option { mss };
VERIFY(packet->buffer->size() >= ipv4_payload_offset + sizeof(TCPPacket) + sizeof(mss_option));
memcpy(packet->buffer->data() + ipv4_payload_offset + sizeof(TCPPacket), &mss_option, sizeof(mss_option));
}
tcp_packet.set_checksum(compute_tcp_checksum(local_address(), peer_address(), tcp_packet, payload_size));
routing_decision.adapter->send_packet(packet->bytes());
m_packets_out++;
m_bytes_out += buffer_size;
if (tcp_packet.has_syn() || payload_size > 0) {
m_unacked_packets.with_exclusive([&](auto& unacked_packets) {
unacked_packets.packets.append({ m_sequence_number, move(packet), ipv4_payload_offset, *routing_decision.adapter });
unacked_packets.size += payload_size;
enqueue_for_retransmit();
});
} else {
routing_decision.adapter->release_packet_buffer(*packet);
}
return {};
}
void TCPSocket::receive_tcp_packet(TCPPacket const& packet, u16 size)
{
if (packet.has_ack()) {
u32 ack_number = packet.ack_number();
dbgln_if(TCP_SOCKET_DEBUG, "TCPSocket: receive_tcp_packet: {}", ack_number);
int removed = 0;
m_unacked_packets.with_exclusive([&](auto& unacked_packets) {
while (!unacked_packets.packets.is_empty()) {
auto& packet = unacked_packets.packets.first();
dbgln_if(TCP_SOCKET_DEBUG, "TCPSocket: iterate: {}", packet.ack_number);
if (packet.ack_number <= ack_number) {
auto old_adapter = packet.adapter.strong_ref();
if (old_adapter)
old_adapter->release_packet_buffer(*packet.buffer);
TCPPacket& tcp_packet = *(TCPPacket*)(packet.buffer->buffer->data() + packet.ipv4_payload_offset);
auto payload_size = packet.buffer->buffer->data() + packet.buffer->buffer->size() - (u8*)tcp_packet.payload();
unacked_packets.size -= payload_size;
evaluate_block_conditions();
unacked_packets.packets.take_first();
removed++;
} else {
break;
}
}
if (unacked_packets.packets.is_empty()) {
m_retransmit_attempts = 0;
dequeue_for_retransmit();
}
dbgln_if(TCP_SOCKET_DEBUG, "TCPSocket: receive_tcp_packet acknowledged {} packets", removed);
});
}
m_packets_in++;
m_bytes_in += packet.header_size() + size;
}
bool TCPSocket::should_delay_next_ack() const
{
// FIXME: We don't know the MSS here so make a reasonable guess.
const size_t mss = 1500;
// RFC 1122 says we should send an ACK for every two full-sized segments.
if (m_ack_number >= m_last_ack_number_sent + 2 * mss)
return false;
// RFC 1122 says we should not delay ACKs for more than 500 milliseconds.
if (kgettimeofday() >= m_last_ack_sent_time + Time::from_milliseconds(500))
return false;
return true;
}
NetworkOrdered<u16> TCPSocket::compute_tcp_checksum(IPv4Address const& source, IPv4Address const& destination, TCPPacket const& packet, u16 payload_size)
{
struct [[gnu::packed]] PseudoHeader {
IPv4Address source;
IPv4Address destination;
u8 zero;
u8 protocol;
NetworkOrdered<u16> payload_size;
};
PseudoHeader pseudo_header { source, destination, 0, (u8)IPv4Protocol::TCP, packet.header_size() + payload_size };
u32 checksum = 0;
auto raw_pseudo_header = bit_cast<u16*>(&pseudo_header);
for (size_t i = 0; i < sizeof(pseudo_header) / sizeof(u16); ++i) {
checksum += AK::convert_between_host_and_network_endian(raw_pseudo_header[i]);
if (checksum > 0xffff)
checksum = (checksum >> 16) + (checksum & 0xffff);
}
auto raw_packet = bit_cast<u16*>(&packet);
for (size_t i = 0; i < packet.header_size() / sizeof(u16); ++i) {
checksum += AK::convert_between_host_and_network_endian(raw_packet[i]);
if (checksum > 0xffff)
checksum = (checksum >> 16) + (checksum & 0xffff);
}
VERIFY(packet.data_offset() * 4 == packet.header_size());
auto raw_payload = bit_cast<u16*>(packet.payload());
for (size_t i = 0; i < payload_size / sizeof(u16); ++i) {
checksum += AK::convert_between_host_and_network_endian(raw_payload[i]);
if (checksum > 0xffff)
checksum = (checksum >> 16) + (checksum & 0xffff);
}
if (payload_size & 1) {
u16 expanded_byte = ((u8 const*)packet.payload())[payload_size - 1] << 8;
checksum += expanded_byte;
if (checksum > 0xffff)
checksum = (checksum >> 16) + (checksum & 0xffff);
}
return ~(checksum & 0xffff);
}
ErrorOr<void> TCPSocket::protocol_bind()
{
if (has_specific_local_address() && !m_adapter) {
m_adapter = NetworkingManagement::the().from_ipv4_address(local_address());
if (!m_adapter)
return set_so_error(EADDRNOTAVAIL);
}
return {};
}
ErrorOr<void> TCPSocket::protocol_listen(bool did_allocate_port)
{
if (!did_allocate_port) {
bool ok = sockets_by_tuple().with_exclusive([&](auto& table) -> bool {
if (table.contains(tuple()))
return false;
table.set(tuple(), this);
return true;
});
if (!ok)
return set_so_error(EADDRINUSE);
}
set_direction(Direction::Passive);
set_state(State::Listen);
set_setup_state(SetupState::Completed);
return {};
}
ErrorOr<void> TCPSocket::protocol_connect(OpenFileDescription& description)
{
MutexLocker locker(mutex());
auto routing_decision = route_to(peer_address(), local_address());
if (routing_decision.is_zero())
return set_so_error(EHOSTUNREACH);
if (!has_specific_local_address())
set_local_address(routing_decision.adapter->ipv4_address());
if (auto result = allocate_local_port_if_needed(); result.error_or_port.is_error())
return result.error_or_port.release_error();
m_sequence_number = get_good_random<u32>();
m_ack_number = 0;
set_setup_state(SetupState::InProgress);
TRY(send_tcp_packet(TCPFlags::SYN));
m_state = State::SynSent;
set_role(Role::Connecting);
m_direction = Direction::Outgoing;
evaluate_block_conditions();
if (description.is_blocking()) {
locker.unlock();
auto unblock_flags = Thread::FileBlocker::BlockFlags::None;
if (Thread::current()->block<Thread::ConnectBlocker>({}, description, unblock_flags).was_interrupted())
return set_so_error(EINTR);
locker.lock();
VERIFY(setup_state() == SetupState::Completed);
if (has_error()) { // TODO: check unblock_flags
set_role(Role::None);
if (error() == TCPSocket::Error::RetransmitTimeout)
return set_so_error(ETIMEDOUT);
else
return set_so_error(ECONNREFUSED);
}
return {};
}
return set_so_error(EINPROGRESS);
}
ErrorOr<u16> TCPSocket::protocol_allocate_local_port()
{
constexpr u16 first_ephemeral_port = 32768;
constexpr u16 last_ephemeral_port = 60999;
constexpr u16 ephemeral_port_range_size = last_ephemeral_port - first_ephemeral_port;
u16 first_scan_port = first_ephemeral_port + get_good_random<u16>() % ephemeral_port_range_size;
return sockets_by_tuple().with_exclusive([&](auto& table) -> ErrorOr<u16> {
for (u16 port = first_scan_port;;) {
IPv4SocketTuple proposed_tuple(local_address(), port, peer_address(), peer_port());
auto it = table.find(proposed_tuple);
if (it == table.end()) {
set_local_port(port);
table.set(proposed_tuple, this);
return port;
}
++port;
if (port > last_ephemeral_port)
port = first_ephemeral_port;
if (port == first_scan_port)
break;
}
return set_so_error(EADDRINUSE);
});
}
bool TCPSocket::protocol_is_disconnected() const
{
switch (m_state) {
case State::Closed:
case State::CloseWait:
case State::LastAck:
case State::FinWait1:
case State::FinWait2:
case State::Closing:
case State::TimeWait:
return true;
default:
return false;
}
}
void TCPSocket::shut_down_for_writing()
{
if (state() == State::Established) {
dbgln_if(TCP_SOCKET_DEBUG, " Sending FIN from Established and moving into FinWait1");
(void)send_tcp_packet(TCPFlags::FIN);
set_state(State::FinWait1);
} else {
dbgln(" Shutting down TCPSocket for writing but not moving to FinWait1 since state is {}", to_string(state()));
}
}
ErrorOr<void> TCPSocket::close()
{
MutexLocker locker(mutex());
auto result = IPv4Socket::close();
if (state() == State::CloseWait) {
dbgln_if(TCP_SOCKET_DEBUG, " Sending FIN from CloseWait and moving into LastAck");
[[maybe_unused]] auto rc = send_tcp_packet(TCPFlags::FIN | TCPFlags::ACK);
set_state(State::LastAck);
}
if (state() != State::Closed && state() != State::Listen)
closing_sockets().with_exclusive([&](auto& table) {
table.set(tuple(), *this);
});
return result;
}
static Singleton<MutexProtected<TCPSocket::RetransmitList>> s_sockets_for_retransmit;
MutexProtected<TCPSocket::RetransmitList>& TCPSocket::sockets_for_retransmit()
{
return *s_sockets_for_retransmit;
}
void TCPSocket::enqueue_for_retransmit()
{
sockets_for_retransmit().with_exclusive([&](auto& list) {
list.append(*this);
});
}
void TCPSocket::dequeue_for_retransmit()
{
sockets_for_retransmit().with_exclusive([&](auto& list) {
list.remove(*this);
});
}
void TCPSocket::retransmit_packets()
{
auto now = kgettimeofday();
// RFC6298 says we should have at least one second between retransmits. According to
// RFC1122 we must do exponential backoff - even for SYN packets.
i64 retransmit_interval = 1;
for (decltype(m_retransmit_attempts) i = 0; i < m_retransmit_attempts; i++)
retransmit_interval *= 2;
if (m_last_retransmit_time > now - Time::from_seconds(retransmit_interval))
return;
dbgln_if(TCP_SOCKET_DEBUG, "TCPSocket({}) handling retransmit", this);
m_last_retransmit_time = now;
++m_retransmit_attempts;
if (m_retransmit_attempts > maximum_retransmits) {
set_state(TCPSocket::State::Closed);
set_error(TCPSocket::Error::RetransmitTimeout);
set_setup_state(Socket::SetupState::Completed);
return;
}
auto routing_decision = route_to(peer_address(), local_address(), bound_interface());
if (routing_decision.is_zero())
return;
m_unacked_packets.with_exclusive([&](auto& unacked_packets) {
for (auto& packet : unacked_packets.packets) {
packet.tx_counter++;
if constexpr (TCP_SOCKET_DEBUG) {
auto& tcp_packet = *(const TCPPacket*)(packet.buffer->buffer->data() + packet.ipv4_payload_offset);
dbgln("Sending TCP packet from {}:{} to {}:{} with ({}{}{}{}) seq_no={}, ack_no={}, tx_counter={}",
local_address(), local_port(),
peer_address(), peer_port(),
(tcp_packet.has_syn() ? "SYN " : ""),
(tcp_packet.has_ack() ? "ACK " : ""),
(tcp_packet.has_fin() ? "FIN " : ""),
(tcp_packet.has_rst() ? "RST " : ""),
tcp_packet.sequence_number(),
tcp_packet.ack_number(),
packet.tx_counter);
}
size_t ipv4_payload_offset = routing_decision.adapter->ipv4_payload_offset();
if (ipv4_payload_offset != packet.ipv4_payload_offset) {
// FIXME: Add support for this. This can happen if after a route change
// we ended up on another adapter which doesn't have the same layer 2 type
// like the previous adapter.
VERIFY_NOT_REACHED();
}
auto packet_buffer = packet.buffer->bytes();
routing_decision.adapter->fill_in_ipv4_header(*packet.buffer,
local_address(), routing_decision.next_hop, peer_address(),
IPv4Protocol::TCP, packet_buffer.size() - ipv4_payload_offset, type_of_service(), ttl());
routing_decision.adapter->send_packet(packet_buffer);
m_packets_out++;
m_bytes_out += packet_buffer.size();
}
});
}
bool TCPSocket::can_write(OpenFileDescription const& file_description, u64 size) const
{
if (!IPv4Socket::can_write(file_description, size))
return false;
if (m_state == State::SynSent || m_state == State::SynReceived)
return false;
if (!file_description.is_blocking())
return true;
return m_unacked_packets.with_shared([&](auto& unacked_packets) {
return unacked_packets.size + size <= m_send_window_size;
});
}
}
Reference in New Issue View Git Blame Copy Permalink