net/SocketDescriptor: add method SetKeepAlive()

src/event/ServerSocket.cxx

@@ -158,7 +158,7 @@ OneServerSocket::Accept() noexcept
 		return;
 	}
 
-	if (socket_keepalive(peer_fd.Get())) {
+	if (!peer_fd.SetKeepAlive()) {
 		const SocketErrorMessage msg;
 		FormatError(server_socket_domain,
 			    "Could not set TCP keepalive option: %s",

src/net/SocketDescriptor.cxx

@@ -207,6 +207,12 @@ SocketDescriptor::SetOption(int level, int name,
 }
 
 bool
+SocketDescriptor::SetKeepAlive(bool value)
+{
+	return SetBoolOption(SOL_SOCKET, SO_KEEPALIVE, value);
+}
+
+bool
 SocketDescriptor::SetReuseAddress(bool value)
 {
 	return SetBoolOption(SOL_SOCKET, SO_REUSEADDR, value);

src/net/SocketDescriptor.hxx

@@ -141,6 +141,7 @@ public:
 		return SetOption(level, name, &value, sizeof(value));
 	}
 
+	bool SetKeepAlive(bool value=true);
 	bool SetReuseAddress(bool value=true);
 
 #ifdef __linux__

src/net/SocketUtil.cxx

@@ -49,12 +49,3 @@ socket_bind_listen(int domain, int type, int protocol,
 
 	return fd;
 }
-
-int
-socket_keepalive(int fd)
-{
-	const int reuse = 1;
-
-	return setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE,
-			  (const char *)&reuse, sizeof(reuse));
-}

src/net/SocketUtil.hxx

@@ -49,7 +49,4 @@ socket_bind_listen(int domain, int type, int protocol,
 		   SocketAddress address,
 		   int backlog);
 
-int
-socket_keepalive(int fd);
-
 #endif