net/SocketDescriptor: add Shutdown()

src/net/SocketDescriptor.cxx

@@ -488,3 +488,25 @@ SocketDescriptor::Write(const void *buffer, size_t length,
 	return ::sendto(Get(), (const char *)buffer, length, flags,
 			address.GetAddress(), address.GetSize());
 }
+
+#ifndef _WIN32
+
+void
+SocketDescriptor::Shutdown() noexcept
+{
+    shutdown(Get(), SHUT_RDWR);
+}
+
+void
+SocketDescriptor::ShutdownRead() noexcept
+{
+    shutdown(Get(), SHUT_RD);
+}
+
+void
+SocketDescriptor::ShutdownWrite() noexcept
+{
+    shutdown(Get(), SHUT_WR);
+}
+
+#endif

src/net/SocketDescriptor.hxx

@@ -241,6 +241,12 @@ public:
 	 */
 	ssize_t Write(const void *buffer, size_t length,
 		      SocketAddress address) noexcept;
+
+#ifndef _WIN32
+	void Shutdown() noexcept;
+	void ShutdownRead() noexcept;
+	void ShutdownWrite() noexcept;
+#endif
 };
 
 static_assert(std::is_trivial<SocketDescriptor>::value, "type is not trivial");