From: Amaury Denoyelle <adenoyelle@haproxy.com>
Date: Tue, 24 May 2022 13:25:19 +0000 (+0200)
Subject: MINOR: h3: define non-h3 generic parsing function
X-Git-Tag: v2.6-dev12~118
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fc99a6933ed0dca6bf0ec1f94ec7e4dbefd59695;p=thirdparty%2Fhaproxy.git

MINOR: h3: define non-h3 generic parsing function

Define a new function h3_parse_uni_stream_no_h3(). It can be used to
handle the payload of streams which does not convey H3 frames. This is
mainly useful for QPACK encoder/decoder streams. It can also be used for
a stream of unknown type which should be drain without parsing it.

This patch is useful to extract code in a dedicated function. It will be
simple to reuse it in h3_decode_qcs() when uni-streams reception is
unify with bidirectional streams, without using dedicated stream tasklet.
---

diff --git a/src/h3.c b/src/h3.c
index 11440e726b..e3a3f77c33 100644
--- a/src/h3.c
+++ b/src/h3.c
@@ -74,6 +74,7 @@ struct h3c {
 DECLARE_STATIC_POOL(pool_head_h3c, "h3c", sizeof(struct h3c));
 
 #define H3_SF_UNI_INIT  0x00000001  /* stream type not parsed for unidirectional stream */
+#define H3_SF_UNI_NO_H3 0x00000002  /* unidirectional stream does not carry H3 frames */
 
 struct h3s {
 	enum h3s_t type;
@@ -135,6 +136,7 @@ static int h3_init_uni_stream(struct h3c *h3c, struct qcs *qcs,
 		}
 		h3c->flags |= H3_CF_UNI_QPACK_DEC_SET;
 		h3s->type = H3S_T_QPACK_DEC;
+		h3s->flags |= H3_SF_UNI_NO_H3;
 		break;
 
 	case H3_UNI_S_T_QPACK_ENC:
@@ -144,9 +146,11 @@ static int h3_init_uni_stream(struct h3c *h3c, struct qcs *qcs,
 		}
 		h3c->flags |= H3_CF_UNI_QPACK_ENC_SET;
 		h3s->type = H3S_T_QPACK_ENC;
+		h3s->flags |= H3_SF_UNI_NO_H3;
 		break;
 
 	default:
+		h3s->flags |= H3_SF_UNI_NO_H3;
 		break;
 	};
 
@@ -156,6 +160,37 @@ static int h3_init_uni_stream(struct h3c *h3c, struct qcs *qcs,
 	return 0;
 }
 
+/* Parse an uni-stream <qcs> from <rxbuf> which does not contains H3 frames.
+ * This may be used for QPACK encoder/decoder streams for example.
+ *
+ * Returns 0 on success else non-zero.
+ */
+static int h3_parse_uni_stream_no_h3(struct qcs *qcs, void *ctx)
+{
+	struct ncbuf *rxbuf = &qcs->rx.ncbuf;
+	struct h3s *h3s = qcs->ctx;
+
+	BUG_ON_HOT(!quic_stream_is_uni(qcs->id) ||
+	           !(h3s->flags & H3_SF_UNI_NO_H3));
+
+	switch (h3s->type) {
+	case H3S_T_QPACK_DEC:
+		if (!qpack_decode_dec(qcs, NULL))
+			return 1;
+		break;
+	case H3S_T_QPACK_ENC:
+		if (!qpack_decode_enc(qcs, NULL))
+			return 1;
+		break;
+	default:
+		/* unknown uni stream : just consume it. */
+		qcs_consume(qcs, ncb_data(rxbuf, 0));
+		break;
+	}
+
+	return 0;
+}
+
 /* Decode a h3 frame header made of two QUIC varints from <b> buffer.
  * Returns the number of bytes consumed if there was enough data in <b>, 0 if not.
  * Note that this function update <b> buffer to reflect the number of bytes consumed
@@ -949,12 +984,12 @@ static int h3_attach_ruqs(struct qcs *qcs, void *ctx)
 		break;
 	case H3S_T_QPACK_ENC:
 		h3c->rqpack_enc.qcs = qcs;
-		h3c->rqpack_enc.cb = qpack_decode_enc;
+		h3c->rqpack_enc.cb = h3_parse_uni_stream_no_h3;
 		qcs_subscribe(qcs, SUB_RETRY_RECV, &h3c->rqpack_enc.wait_event);
 		break;
 	case H3S_T_QPACK_DEC:
 		h3c->rqpack_dec.qcs = qcs;
-		h3c->rqpack_dec.cb = qpack_decode_dec;
+		h3c->rqpack_dec.cb = h3_parse_uni_stream_no_h3;
 		qcs_subscribe(qcs, SUB_RETRY_RECV, &h3c->rqpack_dec.wait_event);
 		break;
 	default: