[tcp] Send xfer_window_changed() when window opens

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

diff --git a/src/net/tcp.c b/src/net/tcp.c
index fbcf279e160737bb35b940e5068ea8bf2a688f99..4df1aed50c732090aaad8927e74e852f6eedeb9f 100644 (file)
--- a/src/net/tcp.c
+++ b/src/net/tcp.c
@@ -391,6 +391,25 @@ static size_t tcp_xmit_win ( struct tcp_connection *tcp ) {
        return len;
 }
 
+/**
+ * Check data-transfer flow control window
+ *
+ * @v tcp              TCP connection
+ * @ret len            Length of window
+ */
+static size_t tcp_xfer_window ( struct tcp_connection *tcp ) {
+
+       /* Not ready if data queue is non-empty.  This imposes a limit
+        * of only one unACKed packet in the TX queue at any time; we
+        * do this to conserve memory usage.
+        */
+       if ( ! list_empty ( &tcp->tx_queue ) )
+               return 0;
+
+       /* Return TCP window length */
+       return tcp_xmit_win ( tcp );
+}
+
 /**
  * Process TCP transmit queue
  *
@@ -1084,6 +1103,7 @@ static int tcp_rx ( struct io_buffer *iobuf,
        unsigned int flags;
        size_t len;
        uint32_t seq_len;
+       size_t old_xfer_window;
        int rc;
 
        /* Sanity check packet */
@@ -1145,6 +1165,9 @@ static int tcp_rx ( struct io_buffer *iobuf,
                goto discard;
        }
 
+       /* Record old data-transfer window */
+       old_xfer_window = tcp_xfer_window ( tcp );
+
        /* Handle ACK, if present */
        if ( flags & TCP_ACK ) {
                if ( ( rc = tcp_rx_ack ( tcp, ack, win ) ) != 0 ) {
@@ -1191,6 +1214,10 @@ static int tcp_rx ( struct io_buffer *iobuf,
                start_timer_fixed ( &tcp->wait, ( 2 * TCP_MSL ) );
        }
 
+       /* Notify application if window has changed */
+       if ( tcp_xfer_window ( tcp ) != old_xfer_window )
+               xfer_window_changed ( &tcp->xfer );
+
        return 0;
 
  discard:
@@ -1256,25 +1283,6 @@ static void tcp_xfer_close ( struct tcp_connection *tcp, int rc ) {
        tcp_xmit ( tcp );
 }
 
-/**
- * Check flow control window
- *
- * @v tcp              TCP connection
- * @ret len            Length of window
- */
-static size_t tcp_xfer_window ( struct tcp_connection *tcp ) {
-
-       /* Not ready if data queue is non-empty.  This imposes a limit
-        * of only one unACKed packet in the TX queue at any time; we
-        * do this to conserve memory usage.
-        */
-       if ( ! list_empty ( &tcp->tx_queue ) )
-               return 0;
-
-       /* Return TCP window length */
-       return tcp_xmit_win ( tcp );
-}
-
 /**
  * Deliver datagram as I/O buffer
  *