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Kernel: Fix TCP sending 

- Fix race condition when adding packet to send buffer before other end
  has acknowledged it
- Allow sending multiple packets before receiving ACK for previous ones
This commit is contained in:
Bananymous 2025-06-04 22:13:11 +03:00
parent 448632cf11
commit bf41b448d6
2 changed files with 13 additions and 9 deletions
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1
kernel/include/kernel/Networking/TCPSocket.h
View File

@ -113,6 +113,7 @@ namespace Kernel
bool has_ghost_byte { false }; bool has_ghost_byte { false };
uint32_t data_size { 0 }; // number of bytes in this buffer uint32_t data_size { 0 }; // number of bytes in this buffer
uint32_t sent_size { 0 }; // number of bytes in this buffer that have been sent
BAN::UniqPtr<VirtualRange> buffer; BAN::UniqPtr<VirtualRange> buffer;
}; };

21
kernel/kernel/Networking/TCPSocket.cpp
View File

@ -717,27 +717,31 @@ namespace Kernel
auto* send_buffer = reinterpret_cast<uint8_t*>(m_send_window.buffer->vaddr()); auto* send_buffer = reinterpret_cast<uint8_t*>(m_send_window.buffer->vaddr());
memmove(send_buffer, send_buffer + acknowledged_bytes, m_send_window.data_size); memmove(send_buffer, send_buffer + acknowledged_bytes, m_send_window.data_size);
} }
else
{ m_send_window.sent_size -= acknowledged_bytes;
m_send_window.last_send_ms = 0;
} epoll_notify(EPOLLOUT);
dprintln_if(DEBUG_TCP, "Target acknowledged {} bytes", acknowledged_bytes); dprintln_if(DEBUG_TCP, "Target acknowledged {} bytes", acknowledged_bytes);
continue; continue;
} }
if (m_send_window.data_size > 0 && current_ms >= m_send_window.last_send_ms + retransmit_timeout_ms) const bool should_retransmit = m_send_window.data_size > 0 && current_ms >= m_send_window.last_send_ms + retransmit_timeout_ms;
if (m_send_window.data_size > m_send_window.sent_size || should_retransmit)
{ {
ASSERT(m_connection_info.has_value()); ASSERT(m_connection_info.has_value());
auto* target_address = reinterpret_cast<const sockaddr*>(&m_connection_info->address); auto* target_address = reinterpret_cast<const sockaddr*>(&m_connection_info->address);
auto target_address_len = m_connection_info->address_len; auto target_address_len = m_connection_info->address_len;
const uint32_t total_send = BAN::Math::min<uint32_t>(m_send_window.data_size, m_send_window.scaled_size()); const uint32_t send_base = should_retransmit ? 0 : m_send_window.sent_size;
const uint32_t total_send = BAN::Math::min<uint32_t>(m_send_window.data_size - send_base, m_send_window.scaled_size());
m_send_window.current_seq = m_send_window.start_seq; m_send_window.current_seq = m_send_window.start_seq;
auto* send_buffer = reinterpret_cast<const uint8_t*>(m_send_window.buffer->vaddr()); auto* send_buffer = reinterpret_cast<const uint8_t*>(m_send_window.buffer->vaddr() + send_base);
for (uint32_t i = 0; i < total_send;) for (uint32_t i = 0; i < total_send;)
{ {
const uint32_t to_send = BAN::Math::min(total_send - i, m_send_window.mss); const uint32_t to_send = BAN::Math::min(total_send - i, m_send_window.mss);
@ -753,10 +757,9 @@ namespace Kernel
dprintln_if(DEBUG_TCP, "Sent {} bytes", to_send); dprintln_if(DEBUG_TCP, "Sent {} bytes", to_send);
m_send_window.sent_size += to_send;
m_send_window.current_seq += to_send; m_send_window.current_seq += to_send;
i += to_send; i += to_send;
epoll_notify(EPOLLOUT);
} }
m_send_window.last_send_ms = current_ms; m_send_window.last_send_ms = current_ms;