From: Libor Peltan <libor.peltan@nic.cz>
Date: Mon, 7 Sep 2020 15:42:31 +0000 (+0200)
Subject: axfr: split multi-mesage responses to 16kib -- compression
X-Git-Tag: v3.1.0~354^2~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e009c2007e51dae72bc3371a3d56fad5749bb0d7;p=thirdparty%2Fknot-dns.git

axfr: split multi-mesage responses to 16kib -- compression
---

diff --git a/src/knot/nameserver/axfr.c b/src/knot/nameserver/axfr.c
index a96f6d6d21..410db29598 100644
--- a/src/knot/nameserver/axfr.c
+++ b/src/knot/nameserver/axfr.c
@@ -57,6 +57,12 @@ static int axfr_put_rrsets(knot_pkt_t *pkt, zone_node_t *node,
 			state->cur_rrset = i;
 			return ret;
 		}
+		if (pkt->size > KNOT_WIRE_PTR_MAX) {
+			// optimization: once the XFR DNS message is > 16 KiB, compression
+			// is limited. Better wrap to next message.
+			state->cur_rrset = i + 1;
+			return KNOT_ESPACE;
+		}
 	}
 
 	state->cur_rrset = 0;