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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 15:26:00 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 15:26:00 +0000
commit830407e88f9d40d954356c3754f2647f91d5c06a (patch)
treed6a0ece6feea91f3c656166dbaa884ef8a29740e /modules/edns_keepalive/edns_keepalive.c
parentInitial commit. (diff)
downloadknot-resolver-830407e88f9d40d954356c3754f2647f91d5c06a.tar.xz
knot-resolver-830407e88f9d40d954356c3754f2647f91d5c06a.zip
Adding upstream version 5.6.0.upstream/5.6.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'modules/edns_keepalive/edns_keepalive.c')
-rw-r--r--modules/edns_keepalive/edns_keepalive.c61
1 files changed, 61 insertions, 0 deletions
diff --git a/modules/edns_keepalive/edns_keepalive.c b/modules/edns_keepalive/edns_keepalive.c
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+/* Copyright (C) CZ.NIC, z.s.p.o. <knot-resolver@labs.nic.cz>
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+/**
+ * @file edns_keepalive.c
+ * @brief Minimalistic EDNS keepalive implementation on server side.
+ * If keepalive option is present in query,
+ * always reply with constant timeout value.
+ *
+ */
+#include <libknot/packet/pkt.h>
+#include "daemon/worker.h"
+#include "lib/module.h"
+#include "lib/layer.h"
+
+static int edns_keepalive_finalize(kr_layer_t *ctx)
+{
+ struct kr_request *req = ctx->req;
+ knot_pkt_t *answer = req->answer;
+ const knot_rrset_t *src_opt = req->qsource.packet->opt_rr;
+ knot_rrset_t *answ_opt = answer->opt_rr;
+
+ const bool ka_want =
+ req->qsource.flags.tcp &&
+ src_opt != NULL &&
+ knot_edns_get_option(src_opt, KNOT_EDNS_OPTION_TCP_KEEPALIVE, NULL) &&
+ answ_opt != NULL;
+ if (!ka_want) {
+ return ctx->state;
+ }
+ const struct network *net = &the_worker->engine->net;
+ uint64_t timeout = net->tcp.in_idle_timeout / 100;
+ if (timeout > UINT16_MAX) {
+ timeout = UINT16_MAX;
+ }
+ knot_mm_t *pool = &answer->mm;
+ uint16_t ka_size = knot_edns_keepalive_size(timeout);
+ uint8_t ka_buf[ka_size];
+ int ret = knot_edns_keepalive_write(ka_buf, ka_size, timeout);
+ if (ret == KNOT_EOK) {
+ ret = knot_edns_add_option(answ_opt, KNOT_EDNS_OPTION_TCP_KEEPALIVE,
+ ka_size, ka_buf, pool);
+ }
+ if (ret != KNOT_EOK) {
+ ctx->state = KR_STATE_FAIL;
+ }
+ return ctx->state;
+}
+
+KR_EXPORT int edns_keepalive_init(struct kr_module *self)
+{
+ static const kr_layer_api_t layer = {
+ .answer_finalize = &edns_keepalive_finalize,
+ };
+ self->layer = &layer;
+ return kr_ok();
+}
+
+KR_MODULE_EXPORT(edns_keepalive)
+