[tls] Eliminate polling while TX state machine is idle

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

diff --git a/src/net/tls.c b/src/net/tls.c
index d80648cccd1bd9c31c7fbeccfe7551af4cf8ac4f..ace719c1151b98f2636e15402e3621ecb5a1188b 100644 (file)
--- a/src/net/tls.c
+++ b/src/net/tls.c
@@ -580,6 +580,62 @@ static void tls_verify_handshake ( struct tls_session *tls, void *out ) {
        digest_final ( sha1, sha1_ctx, sha1_digest );
 }
 
+/******************************************************************************
+ *
+ * TX state machine transitions
+ *
+ ******************************************************************************
+ */
+
+/**
+ * Resume TX state machine
+ *
+ * @v tls              TLS session
+ */
+static void tls_tx_resume ( struct tls_session *tls ) {
+       process_add ( &tls->process );
+}
+
+/**
+ * Enter TX state machine active state
+ *
+ * @v tls              TLS session
+ * @v state            TX state
+ */
+static void tls_tx_start ( struct tls_session *tls, enum tls_tx_state state ) {
+
+       /* Enter specified state */
+       tls->tx_state = state;
+
+       /* Resume state machine */
+       tls_tx_resume ( tls );
+}
+
+/**
+ * Enter TX state machine idle state
+ *
+ * @v tls              TLS session
+ */
+static void tls_tx_none ( struct tls_session *tls ) {
+
+       /* Enter idle state */
+       tls->tx_state = TLS_TX_NONE;
+}
+
+/**
+ * Enter TX state machine data state
+ *
+ * @v tls              TLS session
+ */
+static void tls_tx_data ( struct tls_session *tls ) {
+
+       /* Enter data state */
+       tls->tx_state = TLS_TX_DATA;
+
+       /* Send notification of a window change */
+       xfer_window_changed ( &tls->plainstream );
+}
+
 /******************************************************************************
  *
  * Record handling
@@ -929,7 +985,7 @@ static int tls_new_server_hello_done ( struct tls_session *tls,
        }
 
        /* Start sending the Client Key Exchange */
-       tls->tx_state = TLS_TX_CLIENT_KEY_EXCHANGE;
+       tls_tx_start ( tls, TLS_TX_CLIENT_KEY_EXCHANGE );
 
        return 0;
 }
@@ -946,13 +1002,10 @@ static int tls_new_finished ( struct tls_session *tls,
                              void *data, size_t len ) {
 
        /* FIXME: Handle this properly */
-       tls->tx_state = TLS_TX_DATA;
+       tls_tx_data ( tls );
        ( void ) data;
        ( void ) len;
 
-       /* Send notification of a window change */
-       xfer_window_changed ( &tls->plainstream );
-
        return 0;
 }
 
@@ -1627,6 +1680,7 @@ static int tls_cipherstream_deliver ( struct tls_session *tls,
 static struct interface_operation tls_cipherstream_ops[] = {
        INTF_OP ( xfer_deliver, struct tls_session *,
                  tls_cipherstream_deliver ),
+       INTF_OP ( xfer_window_changed, struct tls_session *, tls_tx_resume ),
        INTF_OP ( intf_close, struct tls_session *, tls_close ),
 };
 
@@ -1647,7 +1701,7 @@ static struct interface_descriptor tls_cipherstream_desc =
  *
  * @v tls              TLS session
  */
-static void tls_step ( struct tls_session *tls ) {
+static void tls_tx_step ( struct tls_session *tls ) {
        int rc;
 
        /* Wait for cipherstream to become ready */
@@ -1665,7 +1719,7 @@ static void tls_step ( struct tls_session *tls ) {
                               tls, strerror ( rc ) );
                        goto err;
                }
-               tls->tx_state = TLS_TX_NONE;
+               tls_tx_none ( tls );
                break;
        case TLS_TX_CLIENT_KEY_EXCHANGE:
                /* Send Client Key Exchange */
@@ -1674,7 +1728,7 @@ static void tls_step ( struct tls_session *tls ) {
                               "%s\n", tls, strerror ( rc ) );
                        goto err;
                }
-               tls->tx_state = TLS_TX_CHANGE_CIPHER;
+               tls_tx_start ( tls, TLS_TX_CHANGE_CIPHER );
                break;
        case TLS_TX_CHANGE_CIPHER:
                /* Send Change Cipher, and then change the cipher in use */
@@ -1691,7 +1745,7 @@ static void tls_step ( struct tls_session *tls ) {
                        goto err;
                }
                tls->tx_seq = 0;
-               tls->tx_state = TLS_TX_FINISHED;
+               tls_tx_start ( tls, TLS_TX_FINISHED );
                break;
        case TLS_TX_FINISHED:
                /* Send Finished */
@@ -1700,7 +1754,7 @@ static void tls_step ( struct tls_session *tls ) {
                               tls, strerror ( rc ) );
                        goto err;
                }
-               tls->tx_state = TLS_TX_NONE;
+               tls_tx_none ( tls );
                break;
        case TLS_TX_DATA:
                /* Nothing to do */
@@ -1717,7 +1771,7 @@ static void tls_step ( struct tls_session *tls ) {
 
 /** TLS TX process descriptor */
 static struct process_descriptor tls_process_desc =
-       PROC_DESC ( struct tls_session, process, tls_step );
+       PROC_DESC_ONCE ( struct tls_session, process, tls_tx_step );
 
 /******************************************************************************
  *
@@ -1749,8 +1803,8 @@ int add_tls ( struct interface *xfer, struct interface **next ) {
                              ( sizeof ( tls->pre_master_secret.random ) ) );
        digest_init ( &md5_algorithm, tls->handshake_md5_ctx );
        digest_init ( &sha1_algorithm, tls->handshake_sha1_ctx );
-       tls->tx_state = TLS_TX_CLIENT_HELLO;
-       process_init ( &tls->process, &tls_process_desc, &tls->refcnt );
+       process_init_stopped ( &tls->process, &tls_process_desc, &tls->refcnt );
+       tls_tx_start ( tls, TLS_TX_CLIENT_HELLO );
 
        /* Attach to parent interface, mortalise self, and return */
        intf_plug_plug ( &tls->plainstream, xfer );