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Kernel/Net: Iron out the locking mechanism across the subsystem

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There is a big mix of LockRefPtrs all over the Networking subsystem, as
well as lots of room for improvements with our locking patterns, which
this commit will not pursue, but will give a good start for such work.

To deal with this situation, we change the following things:
- Creating instances of NetworkAdapter should always yield a non-locking
  NonnullRefPtr. Acquiring an instance from the NetworkingManagement
  should give a simple RefPtr,as giving LockRefPtr does not really
  protect from concurrency problems in such case.
- Since NetworkingManagement works with normal RefPtrs we should
  protect all instances of RefPtr<NetworkAdapter> with SpinlockProtected
  to ensure references are gone unexpectedly.
- Protect the so_error class member with a proper spinlock. This happens
  to be important because the clear_so_error() method lacked any proper
  locking measures. It also helps preventing a possible TOCTOU when we
  might do a more fine-grained locking in the Socket code, so this could
  be definitely a start for this.
- Change unnecessary LockRefPtr<PacketWithTimestamp> in the structure
  of OutgoingPacket to a simple RefPtr<PacketWithTimestamp> as the whole
  list should be MutexProtected.
This commit is contained in:
Liav A 2023-04-11 03:50:15 +03:00 • committed by Linus Groh
parent bd7d4513bf
commit 7c1f645e27
13 changed files with 93 additions and 83 deletions
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4
Kernel/Net/NetworkTask.cpp
View file

@ -31,7 +31,7 @@ static void handle_icmp(EthernetFrameHeader const&, IPv4Packet const&, Time cons
static void handle_udp(IPv4Packet const&, Time const& packet_timestamp);
static void handle_tcp(IPv4Packet const&, Time const& packet_timestamp);
static void send_delayed_tcp_ack(TCPSocket& socket);
static void send_tcp_rst(IPv4Packet const& ipv4_packet, TCPPacket const& tcp_packet, LockRefPtr<NetworkAdapter> adapter);
static void send_tcp_rst(IPv4Packet const& ipv4_packet, TCPPacket const& tcp_packet, RefPtr<NetworkAdapter> adapter);
static void flush_delayed_tcp_acks();
static void retransmit_tcp_packets();
@ -333,7 +333,7 @@ void flush_delayed_tcp_acks()
}
}
void send_tcp_rst(IPv4Packet const& ipv4_packet, TCPPacket const& tcp_packet, LockRefPtr<NetworkAdapter> adapter)
void send_tcp_rst(IPv4Packet const& ipv4_packet, TCPPacket const& tcp_packet, RefPtr<NetworkAdapter> adapter)
{
auto routing_decision = route_to(ipv4_packet.source(), ipv4_packet.destination(), adapter);
if (routing_decision.is_zero())