Kernel: Drop the receive buffer when socket enters the TimeWait state

The TimeWait state is intended to prevent another socket from taking the
address tuple in case any packets are still in transit after the final
close. Since this state never delivers packets to userspace, it doesn't
make sense to keep the receive buffer around.

1 files changed, 10 insertions, 0 deletions

diff --git a/Kernel/Net/IPv4Socket.cpp b/Kernel/Net/IPv4Socket.cpp
index 3f2704ec29..83b3d794f7 100644
--- a/Kernel/Net/IPv4Socket.cpp
+++ b/Kernel/Net/IPv4Socket.cpp
@@ -248,6 +248,9 @@ KResultOr<size_t> IPv4Socket::sendto(OpenFileDescription&, const UserOrKernelBuf
 KResultOr<size_t> IPv4Socket::receive_byte_buffered(OpenFileDescription& description, UserOrKernelBuffer& buffer, size_t buffer_length, int flags, Userspace<sockaddr*>, Userspace<socklen_t*>)
 {
     MutexLocker locker(mutex());
+
+    VERIFY(m_receive_buffer);
+
     if (m_receive_buffer->is_empty()) {
         if (protocol_is_disconnected())
             return 0;
@@ -408,6 +411,8 @@ bool IPv4Socket::did_receive(const IPv4Address& source_address, u16 source_port,
     auto packet_size = packet.size();
 
     if (buffer_mode() == BufferMode::Bytes) {
+        VERIFY(m_receive_buffer);
+
         size_t space_in_receive_buffer = m_receive_buffer->space_for_writing();
         if (packet_size > space_in_receive_buffer) {
             dbgln("IPv4Socket({}): did_receive refusing packet since buffer is full.", this);
@@ -764,4 +769,9 @@ void IPv4Socket::set_can_read(bool value)
         evaluate_block_conditions();
 }
 
+void IPv4Socket::drop_receive_buffer()
+{
+    m_receive_buffer = nullptr;
+}
+
 }