From: Amaury Denoyelle <adenoyelle@haproxy.com>
Date: Wed, 24 Nov 2021 14:29:53 +0000 (+0100)
Subject: CLEANUP: quic: add comments on CID code
X-Git-Tag: v2.6-dev1~370
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=42b9f1c6dd6ffbe978112d450bfad5bca812c1b7;p=thirdparty%2Fhaproxy.git

CLEANUP: quic: add comments on CID code

Add minor comment to explain how the CID are stored in the QUIC
connection.
---

diff --git a/include/haproxy/xprt_quic-t.h b/include/haproxy/xprt_quic-t.h
index e8c6f66e38..ee7b19d342 100644
--- a/include/haproxy/xprt_quic-t.h
+++ b/include/haproxy/xprt_quic-t.h
@@ -246,7 +246,8 @@ extern struct pool_head *pool_head_quic_rx_packet;
 extern struct pool_head *pool_head_quic_tx_packet;
 extern struct pool_head *pool_head_quic_frame;
 
-/*
+/* QUIC connection id data.
+ *
  * This struct is used by ebmb_node structs as last member of flexible arrays.
  * So do not change the order of the member of quic_cid struct.
  * <data> member must be the first one.
@@ -627,10 +628,10 @@ struct quic_conn {
 	struct ebmb_node odcid_node;
 	struct quic_cid odcid;
 
-	struct quic_cid dcid;
+	struct quic_cid dcid; /* DCID of our endpoint - not updated whan a new DCID is used */
 	struct ebmb_node scid_node;
-	struct quic_cid scid;
-	struct eb_root cids;
+	struct quic_cid scid; /* first SCID of our endpoint - not updated when a new SCID is used */
+	struct eb_root cids; /* tree of quic_connection_id - used to match a received packet DCID with a connection */
 
 	struct quic_enc_level els[QUIC_TLS_ENC_LEVEL_MAX];
 	struct quic_pktns pktns[QUIC_TLS_PKTNS_MAX];
diff --git a/include/haproxy/xprt_quic.h b/include/haproxy/xprt_quic.h
index f033b66d08..2b59c37a48 100644
--- a/include/haproxy/xprt_quic.h
+++ b/include/haproxy/xprt_quic.h
@@ -181,6 +181,7 @@ static inline struct quic_connection_id *new_quic_cid(struct eb_root *root,
 
 	cid->seq_num.key = seq_num;
 	cid->retire_prior_to = 0;
+	/* insert the allocated CID in the quic_conn tree */
 	eb64_insert(root, &cid->seq_num);
 
 	return cid;
diff --git a/src/xprt_quic.c b/src/xprt_quic.c
index d36eb46864..c5974052f3 100644
--- a/src/xprt_quic.c
+++ b/src/xprt_quic.c
@@ -3076,7 +3076,7 @@ static struct quic_conn *qc_new_conn(unsigned int version, int ipv4,
 		if (qc->odcid.len)
 			memcpy(qc->odcid.data, dcid, dcid_len);
 
-		/* Copy the SCID as our DCID for this connection. */
+		/* copy the packet SCID to reuse it as DCID for sending */
 		if (scid_len)
 			memcpy(qc->dcid.data, scid, scid_len);
 		qc->dcid.len = scid_len;