From: Frédéric Lécaille <flecaille@haproxy.com>
Date: Thu, 2 Mar 2023 10:53:43 +0000 (+0100)
Subject: BUG/MINOR: quic: Ensure not to retransmit packets with no ack-eliciting frames
X-Git-Tag: v2.8-dev5~36
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=21564be4a2ca209580bbe644b43e758f2536a0da;p=thirdparty%2Fhaproxy.git

BUG/MINOR: quic: Ensure not to retransmit packets with no ack-eliciting frames

Even if there is a check in callers of qc_prep_hdshk_fast_retrans() and
qc_prep_fast_retrans() to prevent retransmissions of packets with no ack-eliciting
frames, these two functions should pay attention not do to that especially if
someone decides to modify their implementations in the future.

Must be backported to 2.6 and 2.7.
---

diff --git a/src/quic_conn.c b/src/quic_conn.c
index 85513bc86a..7c2ee64921 100644
--- a/src/quic_conn.c
+++ b/src/quic_conn.c
@@ -2616,14 +2616,18 @@ static void qc_prep_fast_retrans(struct quic_conn *qc,
 	node = eb64_first(pkts);
  start:
 	while (node) {
-		pkt = eb64_entry(node, struct quic_tx_packet, pn_node);
+		struct quic_tx_packet *p;
+
+		p = eb64_entry(node, struct quic_tx_packet, pn_node);
 		node = eb64_next(node);
 		/* Skip the empty and coalesced packets */
 		TRACE_PRINTF(TRACE_LEVEL_DEVELOPER, QUIC_EV_CONN_SPPKTS, qc, 0, 0, 0,
-		             "--> pn=%llu (%d %d)", (ull)pkt->pn_node.key,
-		             LIST_ISEMPTY(&pkt->frms), !!(pkt->flags & QUIC_FL_TX_PACKET_COALESCED));
-		if (!LIST_ISEMPTY(&pkt->frms))
+		             "--> pn=%llu (%d %d)", (ull)p->pn_node.key,
+		             LIST_ISEMPTY(&p->frms), !!(p->flags & QUIC_FL_TX_PACKET_COALESCED));
+		if (!LIST_ISEMPTY(&p->frms)) {
+			pkt = p;
 			break;
+		}
 	}
 
 	if (!pkt)
@@ -2674,12 +2678,17 @@ static void qc_prep_hdshk_fast_retrans(struct quic_conn *qc,
 	node = eb64_first(pkts);
 	/* Skip the empty packet (they have already been retransmitted) */
 	while (node) {
-		pkt = eb64_entry(node, struct quic_tx_packet, pn_node);
+		struct quic_tx_packet *p;
+
+		p = eb64_entry(node, struct quic_tx_packet, pn_node);
 		TRACE_PRINTF(TRACE_LEVEL_DEVELOPER, QUIC_EV_CONN_SPPKTS, qc, 0, 0, 0,
-		             "--> pn=%llu (%d %d)", (ull)pkt->pn_node.key,
-		             LIST_ISEMPTY(&pkt->frms), !!(pkt->flags & QUIC_FL_TX_PACKET_COALESCED));
-		if (!LIST_ISEMPTY(&pkt->frms) && !(pkt->flags & QUIC_FL_TX_PACKET_COALESCED))
+		             "--> pn=%llu (%d %d)", (ull)p->pn_node.key,
+		             LIST_ISEMPTY(&p->frms), !!(p->flags & QUIC_FL_TX_PACKET_COALESCED));
+		if (!LIST_ISEMPTY(&p->frms) && !(p->flags & QUIC_FL_TX_PACKET_COALESCED)) {
+			pkt = p;
 			break;
+		}
+
 		node = eb64_next(node);
 	}