From: Frédéric Lécaille <flecaille@haproxy.com>
Date: Wed, 27 Apr 2022 13:09:53 +0000 (+0200)
Subject: CLEANUP: quic: Rely on the packet length set by qc_lstnr_pkt_rcv()
X-Git-Tag: v2.6-dev8~16
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=4646cf3b70d82b48e22398c498bd9c5dbe1c8880;p=thirdparty%2Fhaproxy.git

CLEANUP: quic: Rely on the packet length set by qc_lstnr_pkt_rcv()

This function is used to parse the QUIC packets carried by a UDP datagram.
When a correct packet could be found, the ->len RX packet structure value
is set to the packet length value. On the contrary, it is set to the remaining
number of bytes in the UDP datagram if no correct QUIC packet could be found.
So, there is no need to make this function return a status value. It allows
the caller to parse any QUIC packet carried by a UDP datagram without this.
---

diff --git a/src/xprt_quic.c b/src/xprt_quic.c
index 2ffad64e0a..a181c8f0e0 100644
--- a/src/xprt_quic.c
+++ b/src/xprt_quic.c
@@ -4989,9 +4989,19 @@ int qc_conn_alloc_ssl_ctx(struct quic_conn *qc)
 	return 1;
 }
 
-static ssize_t qc_lstnr_pkt_rcv(unsigned char *buf, const unsigned char *end,
-                                struct quic_rx_packet *pkt, int first_pkt,
-                                struct quic_dgram *dgram)
+/* Parse a QUIC packet from UDP datagram found in <buf> buffer with <end> the
+ * end of this buffer past one byte and populate <pkt> RX packet structure
+ * with the information collected from the packet.
+ * This function sets ->len <pkt> field value to the end of the packet past one
+ * byte to enable the caller to run this function again to continue to parse
+ * the remaing QUIC packets carried by the datagram.
+ * Note that this function always sets this ->len value. If a paquet could
+ * not be correctly found, ->len value will be set to the remaining number
+ * bytes in the datagram to entirely consume this latter.
+ */
+static void qc_lstnr_pkt_rcv(unsigned char *buf, const unsigned char *end,
+                             struct quic_rx_packet *pkt, int first_pkt,
+                             struct quic_dgram *dgram)
 {
 	unsigned char *beg, *payload;
 	struct quic_conn *qc, *qc_to_purge = NULL;
@@ -5334,7 +5344,7 @@ static ssize_t qc_lstnr_pkt_rcv(unsigned char *buf, const unsigned char *end,
  drop_no_con:
 	TRACE_LEAVE(QUIC_EV_CONN_LPKT, qc ? qc : NULL, pkt);
 
-	return pkt->len;
+	return;
 
  err:
 	/* Wakeup the I/O handler callback if the PTO timer must be armed.
@@ -5350,8 +5360,6 @@ static ssize_t qc_lstnr_pkt_rcv(unsigned char *buf, const unsigned char *end,
 		pkt->len = end - beg;
 	TRACE_DEVEL("Leaving in error", QUIC_EV_CONN_LPKT,
 	            qc ? qc : NULL, pkt);
-
-	return -1;
 }
 
 /* This function builds into <buf> buffer a QUIC long packet header.
@@ -6196,7 +6204,6 @@ struct task *quic_lstnr_dghdlr(struct task *t, void *ctx, unsigned int state)
 		pos = dgram->buf;
 		end = pos + dgram->len;
 		do {
-			int ret;
 			struct quic_rx_packet *pkt;
 
 			pkt = pool_zalloc(pool_head_quic_rx_packet);
@@ -6204,13 +6211,10 @@ struct task *quic_lstnr_dghdlr(struct task *t, void *ctx, unsigned int state)
 				goto err;
 
 			quic_rx_packet_refinc(pkt);
-			ret = qc_lstnr_pkt_rcv(pos, end, pkt, first_pkt, dgram);
+			qc_lstnr_pkt_rcv(pos, end, pkt, first_pkt, dgram);
 			first_pkt = 0;
 			pos += pkt->len;
 			quic_rx_packet_refdec(pkt);
-			if (ret == -1)
-				/* If the packet length could not be found, we cannot continue. */
-				break;
 		} while (pos < end);
 
 		/* Increasing the received bytes counter by the UDP datagram length