BUG/MINOR: mux-quic: complete flow-control for uni streams

Max stream data was not enforced and respect for local/remote uni
streams. Previously, qcs instances incorrectly reused the limit defined
from bidirectional ones.

This is now fixed. Two fields are added in qcc structure connection :
* value for local flow control to enforce on remote uni streams
* value for remote flow control to respect on local uni streams

These two values can be reused to properly initialized msd field of a
qcs instance in qcs_new(). The rest of the code is similar.

This must be backported up to 2.6.
diff --git a/include/haproxy/mux_quic-t.h b/include/haproxy/mux_quic-t.h
index eaedce4..a55f3db 100644
--- a/include/haproxy/mux_quic-t.h
+++ b/include/haproxy/mux_quic-t.h
@@ -61,8 +61,9 @@
 
 		uint64_t ms_uni; /* max sub-ID of uni stream allowed for the peer */
 
-		uint64_t msd_bidi_l; /* initial max-stream-data on local streams */
-		uint64_t msd_bidi_r; /* initial max-stream-data on remote streams */
+		uint64_t msd_bidi_l; /* initial max-stream-data on local bidi streams */
+		uint64_t msd_bidi_r; /* initial max-stream-data on remote bidi streams */
+		uint64_t msd_uni_r; /* initial max-stream-data on remote uni streams */
 
 		uint64_t md; /* current max-data allowed for the peer */
 		uint64_t md_init; /* initial max-data */
@@ -73,8 +74,9 @@
 	/* flow-control fields set by the peer which we must respect. */
 	struct {
 		uint64_t md; /* connection flow control limit updated on MAX_DATA frames reception */
-		uint64_t msd_bidi_l; /* initial max-stream-data for peer local streams */
-		uint64_t msd_bidi_r; /* initial max-stream-data for peer remote streams */
+		uint64_t msd_bidi_l; /* initial max-stream-data from peer on local bidi streams */
+		uint64_t msd_bidi_r; /* initial max-stream-data from peer on remote bidi streams */
+		uint64_t msd_uni_l; /* initial max-stream-data from peer on local uni streams */
 	} rfctl;
 
 	struct {
diff --git a/src/mux_quic.c b/src/mux_quic.c
index 3baab76..f28bd69 100644
--- a/src/mux_quic.c
+++ b/src/mux_quic.c
@@ -85,17 +85,25 @@
 	qcc->strms[type].nb_streams++;
 
 	/* If stream is local, use peer remote-limit, or else the opposite. */
-	/* TODO use uni limit for unidirectional streams */
-	qcs->tx.msd = quic_stream_is_local(qcc, id) ? qcc->rfctl.msd_bidi_r :
-	                                              qcc->rfctl.msd_bidi_l;
+	if (quic_stream_is_bidi(id)) {
+		qcs->tx.msd = quic_stream_is_local(qcc, id) ? qcc->rfctl.msd_bidi_r :
+		                                              qcc->rfctl.msd_bidi_l;
+	}
+	else if (quic_stream_is_local(qcc, id)) {
+		qcs->tx.msd = qcc->rfctl.msd_uni_l;
+	}
 
 	qcs->rx.ncbuf = NCBUF_NULL;
 	qcs->rx.app_buf = BUF_NULL;
 	qcs->rx.offset = qcs->rx.offset_max = 0;
 
-	/* TODO use uni limit for unidirectional streams */
-	qcs->rx.msd = quic_stream_is_local(qcc, id) ? qcc->lfctl.msd_bidi_l :
-	                                              qcc->lfctl.msd_bidi_r;
+	if (quic_stream_is_bidi(id)) {
+		qcs->rx.msd = quic_stream_is_local(qcc, id) ? qcc->lfctl.msd_bidi_l :
+		                                              qcc->lfctl.msd_bidi_r;
+	}
+	else if (quic_stream_is_remote(qcc, id)) {
+		qcs->rx.msd = qcc->lfctl.msd_uni_r;
+	}
 	qcs->rx.msd_init = qcs->rx.msd;
 
 	qcs->tx.buf = BUF_NULL;
@@ -1943,6 +1951,7 @@
 	qcc->lfctl.ms_uni = lparams->initial_max_streams_uni;
 	qcc->lfctl.msd_bidi_l = lparams->initial_max_stream_data_bidi_local;
 	qcc->lfctl.msd_bidi_r = lparams->initial_max_stream_data_bidi_remote;
+	qcc->lfctl.msd_uni_r = lparams->initial_max_stream_data_uni;
 	qcc->lfctl.cl_bidi_r = 0;
 
 	qcc->lfctl.md = qcc->lfctl.md_init = lparams->initial_max_data;
@@ -1952,6 +1961,7 @@
 	qcc->rfctl.md = rparams->initial_max_data;
 	qcc->rfctl.msd_bidi_l = rparams->initial_max_stream_data_bidi_local;
 	qcc->rfctl.msd_bidi_r = rparams->initial_max_stream_data_bidi_remote;
+	qcc->rfctl.msd_uni_l = rparams->initial_max_stream_data_uni;
 
 	if (conn_is_back(conn)) {
 		qcc->next_bidi_l    = 0x00;