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Kernel/TCP: Port TCP retransmit queue to ProtectedValue

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I had to switch to exclusive locking since ProtectedValue rightly
doesn't allow you to mutate protected data with only a shared lock.
This commit is contained in:
Andreas Kling 2021-08-07 15:42:11 +02:00
parent 4c582b57e9
commit 0cb6c3c831
Notes: sideshowbarker 2024-07-18 07:18:24 +09:00
2 changed files with 71 additions and 65 deletions

127
Kernel/Net/TCPSocket.cpp
View file

@ -254,10 +254,11 @@ KResult TCPSocket::send_tcp_packet(u16 flags, const UserOrKernelBuffer* payload,
m_packets_out++;
m_bytes_out += buffer_size;
if (tcp_packet.has_syn() || payload_size > 0) {
MutexLocker locker(m_not_acked_lock);
m_not_acked.append({ m_sequence_number, move(packet), ipv4_payload_offset, *routing_decision.adapter });
m_not_acked_size += payload_size;
enqueue_for_retransmit();
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);
}
@ -273,33 +274,34 @@ void TCPSocket::receive_tcp_packet(const TCPPacket& packet, u16 size)
dbgln_if(TCP_SOCKET_DEBUG, "TCPSocket: receive_tcp_packet: {}", ack_number);
int removed = 0;
MutexLocker locker(m_not_acked_lock);
while (!m_not_acked.is_empty()) {
auto& packet = m_not_acked.first();
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);
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();
m_not_acked_size -= payload_size;
evaluate_block_conditions();
m_not_acked.take_first();
removed++;
} else {
break;
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 (m_not_acked.is_empty()) {
m_retransmit_attempts = 0;
dequeue_for_retransmit();
}
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);
dbgln_if(TCP_SOCKET_DEBUG, "TCPSocket: receive_tcp_packet acknowledged {} packets", removed);
});
}
m_packets_in++;
@ -560,41 +562,42 @@ void TCPSocket::retransmit_packets()
if (routing_decision.is_zero())
return;
MutexLocker locker(m_not_acked_lock, Mutex::Mode::Shared);
for (auto& packet : m_not_acked) {
packet.tx_counter++;
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);
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, ttl());
routing_decision.adapter->send_packet(packet_buffer);
m_packets_out++;
m_bytes_out += packet_buffer.size();
}
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, ttl());
routing_decision.adapter->send_packet(packet_buffer);
m_packets_out++;
m_bytes_out += packet_buffer.size();
}
});
}
bool TCPSocket::can_write(const FileDescription& file_description, size_t size) const
@ -608,8 +611,8 @@ bool TCPSocket::can_write(const FileDescription& file_description, size_t size)
if (!file_description.is_blocking())
return true;
MutexLocker lock(m_not_acked_lock);
return m_not_acked_size + size <= m_send_window_size;
return m_unacked_packets.with_shared([&](auto& unacked_packets) {
return unacked_packets.size + size <= m_send_window_size;
});
}
}

9
Kernel/Net/TCPSocket.h
View file

@ -203,9 +203,12 @@ private:
int tx_counter { 0 };
};
mutable Mutex m_not_acked_lock { "TCPSocket unacked packets" };
SinglyLinkedList<OutgoingPacket> m_not_acked;
size_t m_not_acked_size { 0 };
struct UnackedPackets {
SinglyLinkedList<OutgoingPacket> packets;
size_t size { 0 };
};
ProtectedValue<UnackedPackets> m_unacked_packets;
u32 m_duplicate_acks { 0 };