From: Frederic Lecaille <flecaille@haproxy.com>
Date: Tue, 24 Jun 2025 08:55:22 +0000 (+0200)
Subject: MINOR: quic-be: add a "CC connection" backend TX buffer pool
X-Git-Tag: v3.3-dev2~15
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=9cb2acd2f274c08eaa87b61c59684ffb79768bfe;p=thirdparty%2Fhaproxy.git

MINOR: quic-be: add a "CC connection" backend TX buffer pool

A QUIC client must be able to close a connection sending Initial packets. But
QUIC client Initial packets must always be at least 1200 bytes long. To reduce
the memory use of TX buffers of a connection when in "closing" state, a pool
was dedicated for this purpose but with a too much reduced TX buffer size
(QUIC_MAX_CC_BUFSIZE).

This patch adds a "closing state connection" TX buffer pool with the same role
for QUIC backends.
---

diff --git a/include/haproxy/quic_tx-t.h b/include/haproxy/quic_tx-t.h
index 19ad777ed..fde45221c 100644
--- a/include/haproxy/quic_tx-t.h
+++ b/include/haproxy/quic_tx-t.h
@@ -4,6 +4,7 @@
 #define QUIC_MIN_CC_PKTSIZE  128
 #define QUIC_DGRAM_HEADLEN  (sizeof(uint16_t) + sizeof(void *))
 #define QUIC_MAX_CC_BUFSIZE (2 * (QUIC_MIN_CC_PKTSIZE + QUIC_DGRAM_HEADLEN))
+#define QUIC_BE_MAX_CC_BUFSIZE MAX(QUIC_INITIAL_IPV6_MTU, QUIC_INITIAL_IPV4_MTU)
 
 /* Sendmsg input buffer cannot be bigger than 65535 bytes. This comes from UDP
  * header which uses a 2-bytes length field. QUIC datagrams are limited to 1252
@@ -21,6 +22,7 @@
 
 extern struct pool_head *pool_head_quic_tx_packet;
 extern struct pool_head *pool_head_quic_cc_buf;
+extern struct pool_head *pool_head_quic_be_cc_buf;
 
 /* Flag a sent packet as being an ack-eliciting packet. */
 #define QUIC_FL_TX_PACKET_ACK_ELICITING (1UL << 0)
diff --git a/src/quic_conn.c b/src/quic_conn.c
index 4cbfa2c53..600d2893c 100644
--- a/src/quic_conn.c
+++ b/src/quic_conn.c
@@ -650,7 +650,12 @@ static void quic_release_cc_conn(struct quic_conn_closed *cc_qc)
 	free_quic_conn_cids(qc);
 	pool_free(pool_head_quic_cids, cc_qc->cids);
 	cc_qc->cids = NULL;
-	pool_free(pool_head_quic_cc_buf, cc_qc->cc_buf_area);
+	if (objt_listener(cc_qc->target)) {
+		pool_free(pool_head_quic_cc_buf, cc_qc->cc_buf_area);
+	}
+	else {
+		pool_free(pool_head_quic_be_cc_buf, cc_qc->cc_buf_area);
+	}
 	cc_qc->cc_buf_area = NULL;
 	/* free the SSL sock context */
 	pool_free(pool_head_quic_conn_closed, cc_qc);
diff --git a/src/quic_tx.c b/src/quic_tx.c
index 611788b15..01b53b60e 100644
--- a/src/quic_tx.c
+++ b/src/quic_tx.c
@@ -33,6 +33,7 @@
 
 DECLARE_POOL(pool_head_quic_tx_packet, "quic_tx_packet", sizeof(struct quic_tx_packet));
 DECLARE_POOL(pool_head_quic_cc_buf, "quic_cc_buf", QUIC_MAX_CC_BUFSIZE);
+DECLARE_POOL(pool_head_quic_be_cc_buf, "quic_be_cc_buf", QUIC_BE_MAX_CC_BUFSIZE);
 
 static struct quic_tx_packet *qc_build_pkt(unsigned char **pos, const unsigned char *buf_end,
                                            struct quic_enc_level *qel, struct quic_tls_ctx *ctx,
@@ -129,16 +130,28 @@ struct buffer *qc_get_txb(struct quic_conn *qc)
 	struct buffer *buf;
 
 	if (qc->flags & QUIC_FL_CONN_IMMEDIATE_CLOSE) {
+		struct pool_head *ph;
+		size_t psz;
+
+		if (objt_listener(qc->target)) {
+			ph = pool_head_quic_cc_buf;
+			psz = QUIC_MAX_CC_BUFSIZE;
+		}
+		else {
+			ph = pool_head_quic_be_cc_buf;
+			psz = QUIC_BE_MAX_CC_BUFSIZE;
+		}
+
 		TRACE_PROTO("Immediate close required", QUIC_EV_CONN_PHPKTS, qc);
 		buf = &qc->tx.cc_buf;
 		if (b_is_null(buf)) {
-			qc->tx.cc_buf_area = pool_alloc(pool_head_quic_cc_buf);
+			qc->tx.cc_buf_area = pool_alloc(ph);
 			if (!qc->tx.cc_buf_area)
 				goto err;
 		}
 
 		/* In every case, initialize ->tx.cc_buf */
-		qc->tx.cc_buf = b_make(qc->tx.cc_buf_area, QUIC_MAX_CC_BUFSIZE, 0, 0);
+		qc->tx.cc_buf = b_make(qc->tx.cc_buf_area, psz, 0, 0);
 	}
 	else {
 		buf = qc_txb_alloc(qc);