MINOR: quic: redirect app_ops snd_buf through mux

This change is required to be able to use multiple app_ops layer on top
of QUIC. The stream-interface will now call the mux snd_buf which is
just a proxy to the app_ops snd_buf function.

The architecture may be simplified in the structure to install the
app_ops on the stream_interface and avoid the detour via the mux layer
on the sending path.

include/haproxy/mux_quic-t.h

@@ -239,6 +239,7 @@ struct qcc_app_ops {
 	int (*init)(struct qcc *qcc);
 	int (*attach_ruqs)(struct qcs *qcs, void *ctx);
 	int (*decode_qcs)(struct qcs *qcs, void *ctx);
+	size_t (*snd_buf)(struct conn_stream *cs, struct buffer *buf, size_t count, int flags);
 	int (*finalize)(void *ctx);
 };
 

include/haproxy/mux_quic.h

@@ -121,7 +121,5 @@ static inline void *qcs_new(struct qcc *qcc, uint64_t id)
 		return bidi_qcs_new(qcc, id);
 }
 
-size_t qc_snd_buf(struct conn_stream *cs, struct buffer *buf, size_t count, int flags);
-
 #endif /* USE_QUIC */
 #endif /* _HAPROXY_MUX_QUIC_H */

src/h3.c

@@ -820,5 +820,6 @@ const struct qcc_app_ops h3_ops = {
 	.init        = h3_init,
 	.attach_ruqs = h3_attach_ruqs,
 	.decode_qcs  = h3_decode_qcs,
+	.snd_buf     = h3_snd_buf,
 	.finalize    = h3_finalize,
 };

src/mux_quic.c

@@ -1852,6 +1852,12 @@ static int qc_show_fd(struct buffer *msg, struct connection *conn)
 	return 0;
 }
 
+static size_t qc_snd_buf(struct conn_stream *cs, struct buffer *buf, size_t count, int flags)
+{
+	struct qcs *qcs = cs->ctx;
+	return qcs->qcc->app_ops->snd_buf(cs, buf, count, flags);
+}
+
 /****************************************/
 /* MUX initialization and instantiation */
 /***************************************/
@@ -1860,8 +1866,7 @@ static int qc_show_fd(struct buffer *msg, struct connection *conn)
 static const struct mux_ops qc_ops = {
 	.init = qc_init,
 	.wake = qc_wake,
-	//.snd_buf = qc_snd_buf,
+	.snd_buf = qc_snd_buf,
-	.snd_buf = h3_snd_buf,
 	.rcv_buf = qc_rcv_buf,
 	.subscribe = qc_subscribe,
 	.unsubscribe = qc_unsubscribe,