MINOR: mux-quic/h3: send SETTINGS as soon as transport is ready
As specified by HTTP3 RFC, SETTINGS frame should be sent as soon as
possible. Before this patch, this was only done on the first qc_send()
invocation. This delay significantly SETTINGS emission until the first
H3 response is ready to be transferred.
This patch fixes this by ensuring SETTINGS is emitted when MUX-QUIC is
being setup.
As a side point, return value of finalize operation is checked. This
means that an error during SETTINGS emission will cause the connection
init to fail.
This should be backported up to 2.7.
diff --git a/include/haproxy/mux_quic-t.h b/include/haproxy/mux_quic-t.h
index 43a7ccc..4ce088e 100644
--- a/include/haproxy/mux_quic-t.h
+++ b/include/haproxy/mux_quic-t.h
@@ -30,7 +30,6 @@
#define QC_CF_CC_EMIT 0x00000001 /* A CONNECTION_CLOSE is set by the MUX */
#define QC_CF_BLK_MFCTL 0x00000002 /* sending blocked due to connection flow-control */
#define QC_CF_CONN_FULL 0x00000004 /* no stream buffers available on connection */
-#define QC_CF_APP_FINAL 0x00000008 /* The application layer was finalized */
struct qcc {
struct connection *conn;
diff --git a/src/h3.c b/src/h3.c
index f7bd8a1..9a1d97d 100644
--- a/src/h3.c
+++ b/src/h3.c
@@ -1636,6 +1636,10 @@
TRACE_LEAVE(H3_EV_H3S_END, qcs->qcc->conn, qcs);
}
+/* Initialize H3 control stream and prepare SETTINGS emission.
+ *
+ * Returns 0 on success else non-zero.
+ */
static int h3_finalize(void *ctx)
{
struct h3c *h3c = ctx;
@@ -1643,12 +1647,12 @@
qcs = qcc_init_stream_local(h3c->qcc, 0);
if (!qcs)
- return 0;
+ return 1;
h3_control_send(qcs, h3c);
h3c->ctrl_strm = qcs;
- return 1;
+ return 0;
}
/* Generate a GOAWAY frame for <h3c> connection on the control stream.
diff --git a/src/mux_quic.c b/src/mux_quic.c
index 31d5a3a..b7b843e 100644
--- a/src/mux_quic.c
+++ b/src/mux_quic.c
@@ -883,6 +883,21 @@
TRACE_PROTO("application layer initialized", QMUX_EV_QCC_NEW, qcc->conn);
+ /* RFC 9114 7.2.4.2. Initialization
+ *
+ * Endpoints MUST NOT require any data to be
+ * received from the peer prior to sending the SETTINGS frame;
+ * settings MUST be sent as soon as the transport is ready to
+ * send data.
+ */
+ if (qcc->app_ops->finalize) {
+ if (qcc->app_ops->finalize(qcc->ctx)) {
+ TRACE_ERROR("app ops finalize error", QMUX_EV_QCC_NEW, qcc->conn);
+ goto err;
+ }
+ tasklet_wakeup(qcc->wait_event.tasklet);
+ }
+
TRACE_LEAVE(QMUX_EV_QCC_NEW, qcc->conn);
return 0;
@@ -1741,15 +1756,6 @@
if (qcc->flags & QC_CF_BLK_MFCTL)
goto err;
- if (!(qcc->flags & QC_CF_APP_FINAL) && !eb_is_empty(&qcc->streams_by_id) &&
- qcc->app_ops->finalize) {
- /* Finalize the application layer before sending any stream.
- * For h3 this consists in preparing the control stream data (SETTINGS h3).
- */
- qcc->app_ops->finalize(qcc->ctx);
- qcc->flags |= QC_CF_APP_FINAL;
- }
-
/* Send STREAM/STOP_SENDING/RESET_STREAM data for registered streams. */
list_for_each_entry_safe(qcs, qcs_tmp, &qcc->send_list, el_send) {
/* Stream must not be present in send_list if it has nothing to send. */