MINOR: mux-quic: add buf_in_flight to QCC debug infos

Dump <buf_in_flight> QCC field both in QUIC MUX traces and "show quic".
This could help to detect if MUX does not allocate enough buffers
compared to quic_conn current congestion window.

src/mux_quic.c

@@ -3399,9 +3399,12 @@ static const struct mux_ops qmux_ops = {
 
 void qcc_show_quic(struct qcc *qcc)
 {
+	const struct quic_conn *qc = qcc->conn->handle.qc;
 	struct eb64_node *node;
-	chunk_appendf(&trash, "  qcc=0x%p flags=0x%x sc=%llu hreq=%llu\n",
-	              qcc, qcc->flags, (ullong)qcc->nb_sc, (ullong)qcc->nb_hreq);
+
+	chunk_appendf(&trash, "  qcc=0x%p flags=0x%x sc=%llu hreq=%llu bwnd=%llu/%llu\n",
+	              qcc, qcc->flags, (ullong)qcc->nb_sc, (ullong)qcc->nb_hreq,
+	              (ullong)qcc->tx.buf_in_flight, (ullong)qc->path->cwnd);
 
 	node = eb64_first(&qcc->streams_by_id);
 	while (node) {

src/qmux_trace.c

@@ -5,6 +5,7 @@
 #include <haproxy/connection.h>
 #include <haproxy/chunk.h>
 #include <haproxy/mux_quic.h>
+#include <haproxy/quic_conn-t.h>
 #include <haproxy/quic_frame-t.h>
 
 /* trace source and events */
@@ -131,14 +132,16 @@ INITCALL1(STG_REGISTER, trace_register_source, TRACE_SOURCE);
 
 void qmux_dump_qcc_info(struct buffer *msg, const struct qcc *qcc)
 {
+	const struct quic_conn *qc = qcc->conn->handle.qc;
+
 	chunk_appendf(msg, " qcc=%p(F)", qcc);
 	if (qcc->conn->handle.qc)
 		chunk_appendf(msg, " qc=%p", qcc->conn->handle.qc);
 	chunk_appendf(msg, " .sc=%llu .hreq=%llu .flg=0x%04x", (ullong)qcc->nb_sc, (ullong)qcc->nb_hreq, qcc->flags);
 
-	chunk_appendf(msg, " .tx=%llu %llu/%llu", (ullong)qcc->tx.fc.off_soft,
-	                                          (ullong)qcc->tx.fc.off_real,
-	                                          (ullong)qcc->tx.fc.limit);
+	chunk_appendf(msg, " .tx=%llu %llu/%llu bwnd=%llu/%llu",
+	              (ullong)qcc->tx.fc.off_soft, (ullong)qcc->tx.fc.off_real, (ullong)qcc->tx.fc.limit,
+	              (ullong)qcc->tx.buf_in_flight, (ullong)qc->path->cwnd);
 }
 
 void qmux_dump_qcs_info(struct buffer *msg, const struct qcs *qcs)