Kernel: Make Socket inherit from File.

Kernel/Net/IPv4Socket.h

@@ -44,6 +44,7 @@ public:
 
 protected:
     IPv4Socket(int type, int protocol);
+    virtual const char* class_name() const override { return "IPv4Socket"; }
 
     int allocate_source_port_if_needed();
 

Kernel/Net/LocalSocket.cpp

@@ -113,6 +113,8 @@ void LocalSocket::attach(FileDescriptor& descriptor)
     case SocketRole::Connecting:
         ++m_connecting_fds_open;
         break;
+    default:
+        break;
     }
 }
 
@@ -131,6 +133,8 @@ void LocalSocket::detach(FileDescriptor& descriptor)
         ASSERT(m_connecting_fds_open);
         --m_connecting_fds_open;
         break;
+    default:
+        break;
     }
 }
 

Kernel/Net/Socket.cpp

@@ -1,3 +1,4 @@
+#include <Kernel/FileSystem/FileDescriptor.h>
 #include <Kernel/Net/Socket.h>
 #include <Kernel/Net/LocalSocket.h>
 #include <Kernel/Net/IPv4Socket.h>
@@ -119,3 +120,22 @@ void Socket::load_send_deadline()
     m_send_deadline.tv_sec += (m_send_timeout.tv_usec / 1000000) * 1;
     m_send_deadline.tv_usec %= 1000000;
 }
+
+static const char* to_string(SocketRole role)
+{
+    switch (role) {
+    case SocketRole::Listener:
+        return "Listener";
+    case SocketRole::Accepted:
+        return "Accepted";
+    case SocketRole::Connected:
+        return "Connected";
+    default:
+        return "None";
+    }
+}
+
+String Socket::absolute_path(FileDescriptor& descriptor) const
+{
+    return String::format("socket:%x (role: %s)", this, to_string(descriptor.socket_role()));
+}

Kernel/Net/Socket.h

@@ -5,6 +5,7 @@
 #include <AK/RetainPtr.h>
 #include <AK/HashTable.h>
 #include <AK/Vector.h>
+#include <Kernel/File.h>
 #include <Kernel/UnixTypes.h>
 #include <Kernel/KResult.h>
 
@@ -13,10 +14,10 @@ enum class ShouldBlock { No = 0, Yes = 1 };
 
 class FileDescriptor;
 
-class Socket : public Retainable<Socket> {
+class Socket : public File {
 public:
     static KResultOr<Retained<Socket>> create(int domain, int type, int protocol);
-    virtual ~Socket();
+    virtual ~Socket() override;
 
     int domain() const { return m_domain; }
     int type() const { return m_type; }
@@ -34,10 +35,6 @@ public:
     virtual bool is_ipv4() const { return false; }
     virtual void attach(FileDescriptor&) = 0;
     virtual void detach(FileDescriptor&) = 0;
-    virtual bool can_read(FileDescriptor&) const = 0;
-    virtual ssize_t read(FileDescriptor&, byte*, ssize_t) = 0;
-    virtual ssize_t write(FileDescriptor&, const byte*, ssize_t) = 0;
-    virtual bool can_write(FileDescriptor&) const = 0;
     virtual ssize_t sendto(FileDescriptor&, const void*, size_t, int flags, const sockaddr*, socklen_t) = 0;
     virtual ssize_t recvfrom(FileDescriptor&, void*, size_t, int flags, sockaddr*, socklen_t*) = 0;
 
@@ -53,6 +50,8 @@ public:
 
     Lock& lock() { return m_lock; }
 
+    virtual String absolute_path(FileDescriptor&) const override;
+
 protected:
     Socket(int domain, int type, int protocol);
 
@@ -61,7 +60,11 @@ protected:
     void load_receive_deadline();
     void load_send_deadline();
 
+    virtual const char* class_name() const override { return "Socket"; }
+
 private:
+    virtual bool is_socket() const final { return true; }
+
     Lock m_lock { "Socket" };
     pid_t m_origin_pid { 0 };
     int m_domain { 0 };

Kernel/Net/TCPSocket.h

@@ -29,6 +29,7 @@ public:
 
 private:
     explicit TCPSocket(int protocol);
+    virtual const char* class_name() const override { return "TCPSocket"; }
 
     NetworkOrdered<word> compute_tcp_checksum(const IPv4Address& source, const IPv4Address& destination, const TCPPacket&, word payload_size);
 

Kernel/Net/UDPSocket.h

@@ -14,6 +14,7 @@ public:
 
 private:
     explicit UDPSocket(int protocol);
+    virtual const char* class_name() const override { return "UDPSocket"; }
 
     virtual int protocol_receive(const ByteBuffer&, void* buffer, size_t buffer_size, int flags, sockaddr* addr, socklen_t* addr_length) override;
     virtual int protocol_send(const void*, int) override;