From: Amaury Denoyelle <adenoyelle@haproxy.com>
Date: Wed, 25 Mar 2026 08:05:21 +0000 (+0100)
Subject: MINOR: xprt_qstrm: implement reception of transport parameters
X-Git-Tag: v3.4-dev8~24
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=531a2b9f1ac45a33629b4c80bb343dd3a089a945;p=thirdparty%2Fhaproxy.git

MINOR: xprt_qstrm: implement reception of transport parameters

Extend xprt_qstrm to implement the reception of QMux transport
parameters. This is performed via conn_recv_qstrm() which relies on the
lower xprt rcv_buf operation. Once received, parameters are kept in
xprt_qstrm context, so that the MUX can retrieve them on init.

For the reception of parameters to be active, the connection must first
be flagged with CO_FL_QSTRM_RECV.
---

diff --git a/include/haproxy/connection-t.h b/include/haproxy/connection-t.h
index 2b8927b82..f803aaf41 100644
--- a/include/haproxy/connection-t.h
+++ b/include/haproxy/connection-t.h
@@ -130,7 +130,8 @@ enum {
 
 	CO_FL_OPT_TOS       = 0x00000020,  /* connection has a special sockopt tos */
 
-	/* unused : 0x00000040, 0x00000080 */
+	/* unused : 0x00000040 */
+	CO_FL_QSTRM_RECV    = 0x00000080,  /* connection uses QMux protocol, needs to exchange transport parameters before starting mux layer */
 
 	/* These flags indicate whether the Control and Transport layers are initialized */
 	CO_FL_CTRL_READY    = 0x00000100, /* FD was registered, fd_delete() needed */
diff --git a/src/xprt_qstrm.c b/src/xprt_qstrm.c
index c9ad39b1b..104197dab 100644
--- a/src/xprt_qstrm.c
+++ b/src/xprt_qstrm.c
@@ -21,14 +21,71 @@ struct xprt_qstrm_ctx {
 
 DECLARE_STATIC_TYPED_POOL(xprt_qstrm_ctx_pool, "xprt_qstrm_ctx", struct xprt_qstrm_ctx);
 
+int conn_recv_qstrm(struct connection *conn, struct xprt_qstrm_ctx *ctx, int flag)
+{
+	struct quic_frame frm;
+	const unsigned char *pos, *end;
+	int ret;
+
+	if (!conn_ctrl_ready(conn))
+		goto fail;
+
+	BUG_ON(conn->flags & CO_FL_FDLESS);
+
+	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 (!trash.data)
+		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. */
+
+	/* 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. */
+
+	ctx->rparams = frm.qmux_transport_params.params;
+
+	conn->flags &= ~flag;
+	return 1;
+
+ not_ready:
+	return 0;
+
+ fail:
+	conn->flags |= CO_FL_ERROR;
+	return 0;
+}
+
 struct task *xprt_qstrm_io_cb(struct task *t, void *context, unsigned int state)
 {
 	struct xprt_qstrm_ctx *ctx = context;
 	struct connection *conn = ctx->conn;
 	int ret;
 
+	if (conn->flags & CO_FL_QSTRM_RECV) {
+		if (!conn_recv_qstrm(conn, ctx, CO_FL_QSTRM_RECV)) {
+			ctx->ops_lower->subscribe(conn, ctx->ctx_lower,
+			                          SUB_RETRY_RECV, &ctx->wait_event);
+			goto out;
+		}
+	}
+
  out:
-	if (conn->flags & CO_FL_ERROR) {
+	if ((conn->flags & CO_FL_ERROR) ||
+	    !(conn->flags & CO_FL_QSTRM_RECV)) {
 		/* MUX will access members from xprt_ctx on init, so create
 		 * operation should be called before any members are resetted.
 		 */