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

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.

1 files changed, 6 insertions, 6 deletions

diff --git a/Kernel/Net/NetworkingManagement.h b/Kernel/Net/NetworkingManagement.h
index 587773030a..ad18a7513e 100644
--- a/Kernel/Net/NetworkingManagement.h
+++ b/Kernel/Net/NetworkingManagement.h
@@ -8,9 +8,9 @@
 
 #include <AK/Function.h>
 #include <AK/NonnullOwnPtr.h>
+#include <AK/RefPtr.h>
 #include <AK/Types.h>
 #include <Kernel/Bus/PCI/Definitions.h>
-#include <Kernel/Library/NonnullLockRefPtr.h>
 #include <Kernel/Locking/SpinlockProtected.h>
 #include <Kernel/Memory/Region.h>
 #include <Kernel/Net/NetworkAdapter.h>
@@ -33,16 +33,16 @@ public:
     void for_each(Function<void(NetworkAdapter&)>);
     ErrorOr<void> try_for_each(Function<ErrorOr<void>(NetworkAdapter&)>);
 
-    LockRefPtr<NetworkAdapter> from_ipv4_address(IPv4Address const&) const;
-    LockRefPtr<NetworkAdapter> lookup_by_name(StringView) const;
+    RefPtr<NetworkAdapter> from_ipv4_address(IPv4Address const&) const;
+    RefPtr<NetworkAdapter> lookup_by_name(StringView) const;
 
-    NonnullLockRefPtr<NetworkAdapter> loopback_adapter() const;
+    NonnullRefPtr<NetworkAdapter> loopback_adapter() const;
 
 private:
     ErrorOr<NonnullRefPtr<NetworkAdapter>> determine_network_device(PCI::DeviceIdentifier const&) const;
 
-    SpinlockProtected<Vector<NonnullLockRefPtr<NetworkAdapter>>, LockRank::None> m_adapters {};
-    LockRefPtr<NetworkAdapter> m_loopback_adapter;
+    SpinlockProtected<Vector<NonnullRefPtr<NetworkAdapter>>, LockRank::None> m_adapters {};
+    RefPtr<NetworkAdapter> m_loopback_adapter;
 };
 
 }