MEDIUM: h2: honor WINDOW_UPDATE frames
Now they really increase the window size of connections and streams.
If a stream was not queued but requested to send, it means it was
flow-controlled so it's added again into the connection's send list.
diff --git a/src/mux_h2.c b/src/mux_h2.c
index d9f0b56..855bd50 100644
--- a/src/mux_h2.c
+++ b/src/mux_h2.c
@@ -952,6 +952,91 @@
return ret;
}
+/* processes a WINDOW_UPDATE frame whose payload is <payload> for <plen> bytes.
+ * Returns > 0 on success or zero on missing data. It may return an error in
+ * h2c or h2s. Described in RFC7540#6.9.
+ */
+static int h2c_handle_window_update(struct h2c *h2c, struct h2s *h2s)
+{
+ int32_t inc;
+ int error;
+
+ if (h2c->dfl != 4) {
+ error = H2_ERR_FRAME_SIZE_ERROR;
+ goto conn_err;
+ }
+
+ /* process full frame only */
+ if (h2c->dbuf->i < h2c->dfl)
+ return 0;
+
+ inc = h2_get_n32(h2c->dbuf, 0);
+
+ if (h2c->dsi != 0) {
+ /* stream window update */
+ if (h2s->st == H2_SS_IDLE) {
+ error = H2_ERR_PROTOCOL_ERROR;
+ goto conn_err;
+ }
+
+ /* it's not an error to receive WU on a closed stream */
+ if (h2s->st == H2_SS_CLOSED)
+ return 1;
+
+ if (!inc) {
+ error = H2_ERR_PROTOCOL_ERROR;
+ goto strm_err;
+ }
+
+ if (h2s->mws >= 0 && h2s->mws + inc < 0) {
+ error = H2_ERR_FLOW_CONTROL_ERROR;
+ goto strm_err;
+ }
+
+ h2s->mws += inc;
+ if (h2s->mws > 0 && (h2s->flags & H2_SF_BLK_SFCTL)) {
+ h2s->flags &= ~H2_SF_BLK_SFCTL;
+ if (h2s->cs && LIST_ISEMPTY(&h2s->list) &&
+ (h2s->cs->flags & CS_FL_DATA_WR_ENA)) {
+ /* This stream wanted to send but could not due to its
+ * own flow control. We can put it back into the send
+ * list now, it will be handled upon next send() call.
+ */
+ LIST_ADDQ(&h2c->send_list, &h2s->list);
+ }
+ }
+ }
+ else {
+ /* connection window update */
+ if (!inc) {
+ error = H2_ERR_PROTOCOL_ERROR;
+ goto conn_err;
+ }
+
+ if (h2c->mws >= 0 && h2c->mws + inc < 0) {
+ error = H2_ERR_FLOW_CONTROL_ERROR;
+ goto conn_err;
+ }
+
+ h2c->mws += inc;
+ }
+
+ return 1;
+
+ conn_err:
+ h2c_error(h2c, error);
+ return 0;
+
+ strm_err:
+ if (h2s) {
+ h2s_error(h2s, error);
+ h2c->st0 = H2_CS_FRAME_A;
+ }
+ else
+ h2c_error(h2c, error);
+ return 0;
+}
+
/* process Rx frames to be demultiplexed */
static void h2_process_demux(struct h2c *h2c)
{
@@ -1056,6 +1141,11 @@
ret = h2c_ack_ping(h2c);
break;
+ case H2_FT_WINDOW_UPDATE:
+ if (h2c->st0 == H2_CS_FRAME_P)
+ ret = h2c_handle_window_update(h2c, h2s);
+ break;
+
/* FIXME: implement all supported frame types here */
default:
/* drop frames that we ignore. They may be larger than