From bf3d2255bfe4fe6819e5fa230136ffa55c4b1965 Mon Sep 17 00:00:00 2001
From: Jan Kadlec <jan.kadlec@nic.cz>
Date: Fri, 29 Aug 2014 11:13:01 +0200
Subject: [PATCH] IXFR: proper handling of AXFR-style IXFR.
---
src/knot/nameserver/ixfr.c | 57 ++++++++++++++++++++++++++++++++------
1 file changed, 49 insertions(+), 8 deletions(-)
diff --git a/src/knot/nameserver/ixfr.c b/src/knot/nameserver/ixfr.c
index c1483f0984..6f89bbd1cf 100644
--- a/src/knot/nameserver/ixfr.c
+++ b/src/knot/nameserver/ixfr.c
@@ -1,3 +1,19 @@
+/* Copyright (C) 2014 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
#include "knot/nameserver/ixfr.h"
#include "knot/nameserver/axfr.h"
#include "knot/nameserver/internet.h"
@@ -308,6 +324,21 @@ static int ixfr_answer_soa(knot_pkt_t *pkt, struct query_data *qdata)
#define IXFRIN_LOG(severity, msg...) \
ANSWER_LOG(severity, adata, "IXFR, incoming", msg)
+/*! \brief Checks whether IXFR response contains enough data for processing. */
+static bool ixfr_enough_data(const knot_pkt_t *pkt)
+{
+ const knot_pktsection_t *answer = knot_pkt_section(pkt, KNOT_ANSWER);
+ return answer->count >= 2;
+}
+
+/*! \brief Checks whether server responded with AXFR-style IXFR. */
+static bool ixfr_is_axfr(const knot_pkt_t *pkt)
+{
+ const knot_pktsection_t *answer = knot_pkt_section(pkt, KNOT_ANSWER);
+ return answer->rr[0].type == KNOT_RRTYPE_SOA &&
+ answer->rr[1].type != KNOT_RRTYPE_SOA;
+}
+
/*! \brief Cleans up data allocated by IXFR-in processing. */
static void ixfrin_cleanup(struct answer_data *data)
{
@@ -351,7 +382,7 @@ static int ixfrin_finalize(struct answer_data *adata)
zone_contents_t *new_contents;
int ret = apply_changesets(ixfr->zone, &ixfr->changesets, &new_contents);
if (ret != KNOT_EOK) {
- IXFRIN_LOG(LOG_ERR, "failed to apply changes to zone (%s)",
+ IXFRIN_LOG(LOG_WARNING, "failed to apply changes to zone (%s)",
knot_strerror(ret));
return ret;
}
@@ -359,7 +390,7 @@ static int ixfrin_finalize(struct answer_data *adata)
/* Write changes to journal. */
ret = zone_changes_store(ixfr->zone, &ixfr->changesets);
if (ret != KNOT_EOK) {
- IXFRIN_LOG(LOG_ERR, "failed to write changes to journal (%s)",
+ IXFRIN_LOG(LOG_WARNING, "failed to write changes to journal (%s)",
knot_strerror(ret));
updates_rollback(&ixfr->changesets);
update_free_zone(&new_contents);
@@ -563,7 +594,7 @@ static int process_ixfrin_packet(knot_pkt_t *pkt, struct answer_data *adata)
int ret = ixfrin_step(rr, ixfr);
if (ret != KNOT_EOK) {
- IXFRIN_LOG(LOG_ERR, "failed (%s)", knot_strerror(ret));
+ IXFRIN_LOG(LOG_WARNING, "failed (%s)", knot_strerror(ret));
return NS_PROC_FAIL;
}
@@ -633,7 +664,7 @@ int ixfr_query(knot_pkt_t *pkt, struct query_data *qdata)
case KNOT_EOK: /* Last response. */
gettimeofday(&now, NULL);
IXFROUT_LOG(LOG_INFO,
- "finished, %.02f seconds, %u messages, %u bytes",
+ "finished, %.02f seconds, %u messages, %u bytes",
time_diff(&ixfr->proc.tstamp, &now) / 1000.0,
ixfr->proc.npkts, ixfr->proc.nbytes);
ret = NS_PROC_DONE;
@@ -652,17 +683,27 @@ int ixfr_process_answer(knot_pkt_t *pkt, struct answer_data *adata)
if (pkt == NULL || adata == NULL) {
return NS_PROC_FAIL;
}
-
+
+ if (!ixfr_enough_data(pkt)) {
+ return NS_PROC_FAIL;
+ }
+
+ /* Check for AXFR-style IXFR. */
+ if (ixfr_is_axfr(pkt)) {
+ IXFRIN_LOG(LOG_NOTICE, "Fallback to AXFR");
+ return axfr_answer_process(pkt, adata);
+ }
+
/* Check RCODE. */
uint8_t rcode = knot_wire_get_rcode(pkt->wire);
if (rcode != KNOT_RCODE_NOERROR) {
knot_lookup_table_t *lut = knot_lookup_by_id(knot_rcode_names, rcode);
if (lut != NULL) {
- IXFRIN_LOG(LOG_ERR, "server responded with %s", lut->name);
+ IXFRIN_LOG(LOG_WARNING, "server responded with %s", lut->name);
}
return NS_PROC_FAIL;
}
-
+
/* Initialize processing with first packet. */
if (adata->ext == NULL) {
NS_NEED_TSIG_SIGNED(&adata->param->tsig_ctx, 0);
@@ -675,7 +716,7 @@ int ixfr_process_answer(knot_pkt_t *pkt, struct answer_data *adata)
// First packet with IXFR, init context
int ret = ixfrin_answer_init(adata);
if (ret != KNOT_EOK) {
- IXFRIN_LOG(LOG_ERR, "failed (%s)", knot_strerror(ret));
+ IXFRIN_LOG(LOG_WARNING, "failed (%s)", knot_strerror(ret));
return NS_PROC_FAIL;
}
} else {
--
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