From: Marek Vavruša <mvavrusa@cloudflare.com>
Date: Tue, 20 Mar 2018 22:41:05 +0000 (-0700)
Subject: daemon/worker: allow large responses for outbound over TCP
X-Git-Tag: v2.2.0~3^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=78c1d32ddc4796d1331c7e02763debce7e829e33;p=thirdparty%2Fknot-resolver.git

daemon/worker: allow large responses for outbound over TCP

This was previously fixed in e25358d4f6521a55c33ec1d3a55f2bf6e2f99607,
but broken in the rewrite. The answer buffer size must be a maximum size,
otherwise payloads larger than configured UDP buffer size can't be
transmitted over TCP.
---

diff --git a/daemon/worker.c b/daemon/worker.c
index eec567139..62b87ee26 100644
--- a/daemon/worker.c
+++ b/daemon/worker.c
@@ -2154,6 +2154,16 @@ int worker_process_tcp(struct worker_ctx *worker, uv_stream_t *handle,
 			/* FIXME: on high load over one connection, it's likely
 			 * that we will get multiple matches sooner or later (!) */
 			if (task) {
+				/* Make sure we can process maximum packet sizes over TCP for outbound queries.
+				 * Previous packet is allocated with mempool, so there's no need to free it manually. */
+				if (task->pktbuf->max_size < KNOT_WIRE_MAX_PKTSIZE) {
+						knot_mm_t *pool = &task->pktbuf->mm;
+						pkt_buf = knot_pkt_new(NULL, KNOT_WIRE_MAX_PKTSIZE, pool);
+						if (!pkt_buf) {
+								return kr_error(ENOMEM);
+						}
+						task->pktbuf = pkt_buf;
+				}
 				knot_pkt_clear(task->pktbuf);
 				assert(task->leading == false);
 			} else	{