[tcp] Display "connecting" status until connection is established

Provide increased visibility into the progress of TCP connections by
displaying an explicit "connecting" status message while waiting for
the TCP handshake to complete.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/net/tcp.c

 #include <ipxe/netdevice.h>
 #include <ipxe/profile.h>
 #include <ipxe/process.h>
+#include <ipxe/job.h>
 #include <ipxe/tcpip.h>
 #include <ipxe/tcp.h>
 
 	return 0;
 }
 
+/**
+ * Report job progress
+ *
+ * @v tcp		TCP connection
+ * @v progress		Progress report to fill in
+ * @ret ongoing_rc	Ongoing job status code (if known)
+ */
+static int tcp_progress ( struct tcp_connection *tcp,
+			  struct job_progress *progress ) {
+
+	/* Report connection in progress if applicable */
+	if ( ! TCP_HAS_BEEN_ESTABLISHED ( tcp->tcp_state ) ) {
+		snprintf ( progress->message, sizeof ( progress->message ),
+			   "connecting" );
+	}
+
+	return 0;
+}
+
 /** TCP data transfer interface operations */
 static struct interface_operation tcp_xfer_operations[] = {
 	INTF_OP ( xfer_deliver, struct tcp_connection *, tcp_xfer_deliver ),
 	INTF_OP ( xfer_window, struct tcp_connection *, tcp_xfer_window ),
+	INTF_OP ( job_progress, struct tcp_connection *, tcp_progress ),
 	INTF_OP ( intf_close, struct tcp_connection *, tcp_xfer_close ),
 };