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

diff --git a/modules/dnstap/README.rst b/modules/dnstap/README.rst
index ee76ba7ab6f656456ea1b25133fcd1601cb911f9..5a218dd19cb729978d2fdfd9d6e486bb8fdc0e91 100644 (file)
--- 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 b774860112e69935ed12cd071dec959df82ea017..14214660311c7713569871d9bf5d1f66553b3ea6 100644 (file)
--- 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;
                }