From: Amaury Denoyelle <adenoyelle@haproxy.com>
Date: Tue, 7 Apr 2026 13:19:47 +0000 (+0200)
Subject: MINOR: xprt_qstrm: implement Rx buffering
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=890831f29245c9a1dacea4d17271c8dfb167c83c;p=thirdparty%2Fhaproxy.git

MINOR: xprt_qstrm: implement Rx buffering

Implement buffering for reception on xprt_qstrm layer. This is necessary
to handle reception of a truncated QMux transport parameters frame.

This is performed via a new dedicated <rxbuf> member in xprt_qstrm
context. Read is performed by reusing the buffer until a whole frame can
be read.
---

diff --git a/src/xprt_qstrm.c b/src/xprt_qstrm.c
index 111e83c57..7b44cd26c 100644
--- a/src/xprt_qstrm.c
+++ b/src/xprt_qstrm.c
@@ -1,6 +1,7 @@
 #include <haproxy/api.h>
 #include <haproxy/buf.h>
 #include <haproxy/connection.h>
+#include <haproxy/dynbuf.h>
 #include <haproxy/fd.h>
 #include <haproxy/global.h>
 #include <haproxy/mux_quic.h>
@@ -18,6 +19,8 @@ struct xprt_qstrm_ctx {
 
 	struct quic_transport_params lparams;
 	struct quic_transport_params rparams;
+
+	struct buffer rxbuf;
 };
 
 DECLARE_STATIC_TYPED_POOL(xprt_qstrm_ctx_pool, "xprt_qstrm_ctx", struct xprt_qstrm_ctx);
@@ -37,8 +40,9 @@ const struct quic_transport_params *xprt_qstrm_rparams(const void *context)
 int conn_recv_qstrm(struct connection *conn, struct xprt_qstrm_ctx *ctx, int flag)
 {
 	struct quic_frame frm;
+	struct buffer *buf = &ctx->rxbuf;
 	const unsigned char *pos, *end;
-	int ret;
+	size_t ret;
 
 	if (!conn_ctrl_ready(conn))
 		goto fail;
@@ -48,26 +52,27 @@ int conn_recv_qstrm(struct connection *conn, struct xprt_qstrm_ctx *ctx, int fla
 	if (!fd_recv_ready(conn->handle.fd))
 		goto not_ready;
 
-	while (1) {
-		ret = ctx->ops_lower->rcv_buf(conn, ctx->ctx_lower, &trash, trash.size, NULL, 0, MSG_PEEK);
-		BUG_ON(conn->flags & CO_FL_ERROR); /* TODO handle fatal errors */
-		trash.data = ret;
-		break;
-	}
+	if (!b_size(buf) && !b_alloc(buf, DB_MUX_RX))
+		goto fail;
+
+	do {
+		ret = ctx->ops_lower->rcv_buf(conn, ctx->ctx_lower, buf, b_room(buf), NULL, 0, 0);
+		BUG_ON(conn->flags & CO_FL_ERROR);
+	} while (ret);
 
-	if (!trash.data)
+	if (!b_data(buf))
 		goto not_ready;
 
-	pos = (unsigned char *)b_orig(&trash);
-	end = (unsigned char *)(b_orig(&trash) + b_data(&trash));
-	ret = qc_parse_frm_type(&frm, &pos, end, NULL);
-	BUG_ON(!ret); /* TODO handle a truncated frame, recv must be performed again. */
+	pos = (unsigned char *)b_orig(buf);
+	end = (unsigned char *)(b_orig(buf) + b_data(buf));
+	if (!qc_parse_frm_type(&frm, &pos, end, NULL))
+		goto not_ready;
 
 	/* TODO close connection with TRANSPORT_PARAMETER_ERROR if frame not present. */
 	BUG_ON(frm.type != QUIC_FT_QX_TRANSPORT_PARAMETERS);
 
-	ret = qc_parse_frm_payload(&frm, &pos, end, NULL);
-	BUG_ON(!ret); /* TODO handle a truncated frame, recv must be performed again. */
+	if (!qc_parse_frm_payload(&frm, &pos, end, NULL))
+		goto not_ready;
 
 	ctx->rparams = frm.qmux_transport_params.params;
 
@@ -149,6 +154,8 @@ struct task *xprt_qstrm_io_cb(struct task *t, void *context, unsigned int state)
 		conn->xprt = ctx->ops_lower;
 		conn->mux->wake(conn);
 
+		b_free(&ctx->rxbuf);
+
 		tasklet_free(ctx->wait_event.tasklet);
 		pool_free(xprt_qstrm_ctx_pool, ctx);
 		t = NULL;
@@ -195,6 +202,8 @@ static int xprt_qstrm_init(struct connection *conn, void **xprt_ctx)
 	ctx->ctx_lower = NULL;
 	ctx->ops_lower = NULL;
 
+	ctx->rxbuf = BUF_NULL;
+
 	memset(&ctx->rparams, 0, sizeof(struct quic_transport_params));
 
 	/* TP configuration advertised by us */