dnstap: optionally log client requests; don't log internal ones

2 files changed, 48 insertions, 9 deletions

diff --git a/modules/dnstap/README.rst b/modules/dnstap/README.rst
index ee76ba7a..5a218dd1 100644
--- a/modules/dnstap/README.rst
+++ b/modules/dnstap/README.rst
@@ -5,8 +5,8 @@
 Dnstap (traffic collection)
 ===========================
 
-The ``dnstap`` module supports logging DNS responses to a unix socket
-in `dnstap format <https://dnstap.info>`_ using fstrm framing library.
+The ``dnstap`` module supports logging DNS requests and responses to a unix
+socket in `dnstap format <https://dnstap.info>`_ using fstrm framing library.
 This logging is useful if you need effectivelly log all DNS traffic.
 
 The unix socket and the socket reader must be present before starting resolver instances.
@@ -14,13 +14,17 @@ The unix socket and the socket reader must be present before starting resolver i
 Tunables:
 
 * ``socket_path``: the the unix socket file where dnstap messages will be sent
-* ``log_responses``: if ``true`` responses in wire format will be logged
+* ``client.log_requests``: if ``true`` requests from downstream in wire format will be logged
+* ``client.log_responses``: if ``true`` responses to downstream in wire format will be logged
 
 .. code-block:: lua
 
     modules = {
         dnstap = {
             socket_path = "/tmp/dnstap.sock",
-            log_responses = true
+            client = {
+                log_requests = true,
+                log_responses = true,
+            },
         }
     }
diff --git a/modules/dnstap/dnstap.c b/modules/dnstap/dnstap.c
index b7748601..14214660 100644
--- a/modules/dnstap/dnstap.c
+++ b/modules/dnstap/dnstap.c
@@ -16,6 +16,8 @@
 
 #define DEBUG_MSG(fmt, ...) kr_log_verbose("[dnstap] " fmt, ##__VA_ARGS__);
 #define CFG_SOCK_PATH "socket_path"
+#define CFG_LOG_CLIENT_PKT "client"
+#define CFG_LOG_REQ_PKT "log_requests"
 #define CFG_LOG_RESP_PKT "log_responses"
 #define DEFAULT_SOCK_PATH "/tmp/dnstap.sock"
 #define DNSTAP_CONTENT_TYPE "protobuf:dnstap.Dnstap"
@@ -26,6 +28,7 @@
 
 /* Internal data structure */
 struct dnstap_data {
+	bool log_req_pkt;
 	bool log_resp_pkt;
 	struct fstrm_iothr *iothread;
 	struct fstrm_iothr_queue *ioq;
@@ -82,6 +85,10 @@ static int dnstap_log(kr_layer_t *ctx) {
 	const struct kr_rplan *rplan = &req->rplan;
 	const struct dnstap_data *dnstap_dt = module->data;
 
+	if (!req->qsource.addr) {
+		return ctx->state;
+	}
+
 	/* check if we have a valid iothread */
 	if (!dnstap_dt->iothread || !dnstap_dt->ioq) {
 		DEBUG_MSG("dnstap_dt->iothread or dnstap_dt->ioq is NULL\n");
@@ -98,8 +105,12 @@ static int dnstap_log(kr_layer_t *ctx) {
 	memset(&m, 0, sizeof(m));
 
 	m.base.descriptor = &dnstap__message__descriptor;
-	/* Only handling response */
-	m.type = DNSTAP__MESSAGE__TYPE__RESOLVER_RESPONSE;
+	if (dnstap_dt->log_req_pkt && !dnstap_dt->log_resp_pkt) {
+		m.type = DNSTAP__MESSAGE__TYPE__CLIENT_QUERY;
+	}
+	else {
+		m.type = DNSTAP__MESSAGE__TYPE__CLIENT_RESPONSE;
+	}
 
 	if (req->qsource.addr) {
 		set_address(req->qsource.addr,
@@ -134,6 +145,15 @@ static int dnstap_log(kr_layer_t *ctx) {
 		}
 	}
 
+	if (dnstap_dt->log_req_pkt) {
+		const knot_pkt_t *qpkt = req->qsource.packet;
+		m.has_query_message = qpkt != NULL;
+		if (qpkt != NULL) {
+			m.query_message.len = qpkt->size;
+			m.query_message.data = (uint8_t *)qpkt->wire;
+		}
+	}
+
 	if (dnstap_dt->log_resp_pkt) {
 		const knot_pkt_t *rpkt = req->answer;
 		m.has_response_message = rpkt != NULL;
@@ -318,11 +338,26 @@ int dnstap_config(struct kr_module *module, const char *conf) {
 			sock_path = strndup(DEFAULT_SOCK_PATH, PATH_MAX);
 		}
 
-		/* logRespPkt key */
-		node = json_find_member(root_node, CFG_LOG_RESP_PKT);
+		node = json_find_member(root_node, CFG_LOG_CLIENT_PKT);
 		if (node) {
-			data->log_resp_pkt = find_bool(node);
+			JsonNode *subnode;
+			/* logRespPkt key */
+			subnode = json_find_member(node, CFG_LOG_RESP_PKT);
+			if (subnode) {
+				data->log_resp_pkt = find_bool(subnode);
+			} else {
+				data->log_resp_pkt = false;
+			}
+
+			/* logReqPkt key */
+			subnode = json_find_member(node, CFG_LOG_REQ_PKT);
+			if (subnode) {
+				data->log_req_pkt = find_bool(subnode);
+			} else {
+				data->log_req_pkt = false;
+			}
 		} else {
+			data->log_req_pkt = false;
 			data->log_resp_pkt = false;
 		}