Adding upstream version 3.2.1.upstream/3.2.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 382 insertions, 0 deletions

diff --git a/modules/dnstap/dnstap.c b/modules/dnstap/dnstap.c
new file mode 100644
index 0000000..0918426
--- /dev/null
+++ b/modules/dnstap/dnstap.c
@@ -0,0 +1,382 @@
+/*
+ * 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 <https://www.gnu.org/licenses/>.
+ *
+ * @file dnstap.c
+ * @brief dnstap based query logging support
+ *
+ */
+
+#include "lib/module.h"
+#include "lib/layer.h"
+#include "lib/resolve.h"
+#include "modules/dnstap/dnstap.pb-c.h"
+#include <ccan/json/json.h>
+#include <fstrm.h>
+#include "contrib/cleanup.h"
+
+#define DEBUG_MSG(fmt, ...) kr_log_verbose("[dnstap] " fmt, ##__VA_ARGS__);
+#define CFG_SOCK_PATH "socket_path"
+#define CFG_LOG_RESP_PKT "log_responses"
+#define DEFAULT_SOCK_PATH "/tmp/dnstap.sock"
+#define DNSTAP_CONTENT_TYPE "protobuf:dnstap.Dnstap"
+#define DNSTAP_INITIAL_BUF_SIZE         256
+
+#define auto_destroy_uopts __attribute__((cleanup(fstrm_unix_writer_options_destroy)))
+#define auto_destroy_wopts __attribute__((cleanup(fstrm_writer_options_destroy)))
+
+/* Internal data structure */
+struct dnstap_data {
+	bool log_resp_pkt;
+	struct fstrm_iothr *iothread;
+	struct fstrm_iothr_queue *ioq;
+};
+
+/*
+ * dt_pack packs the dnstap message for transport
+ * https://gitlab.labs.nic.cz/knot/knot-dns/blob/master/src/contrib/dnstap/dnstap.c#L24
+ * */
+uint8_t* dt_pack(const Dnstap__Dnstap *d, uint8_t **buf, size_t *sz)
+{
+	ProtobufCBufferSimple sbuf = { { NULL } };
+
+	sbuf.base.append = protobuf_c_buffer_simple_append;
+	sbuf.len = 0;
+	sbuf.alloced = DNSTAP_INITIAL_BUF_SIZE;
+	sbuf.data = malloc(sbuf.alloced);
+	if (sbuf.data == NULL) {
+		return NULL;
+	}
+	sbuf.must_free_data = true;
+
+	*sz = dnstap__dnstap__pack_to_buffer(d, (ProtobufCBuffer *) &sbuf);
+	*buf = sbuf.data;
+	return *buf;
+}
+
+/* set_address fills in address detail in dnstap_message
+ * https://gitlab.labs.nic.cz/knot/knot-dns/blob/master/src/contrib/dnstap/message.c#L28
+ */
+static void set_address(const struct sockaddr *sockaddr,
+		ProtobufCBinaryData   *addr,
+		protobuf_c_boolean    *has_addr,
+		uint32_t              *port,
+		protobuf_c_boolean    *has_port) {
+	const char *saddr = kr_inaddr(sockaddr);
+	if (saddr == NULL) {
+		*has_addr = false;
+		*has_port = false;
+		return;
+	}
+
+	addr->data = (uint8_t *)(saddr);
+	addr->len = kr_inaddr_len(sockaddr);
+	*has_addr = true;
+	*port = kr_inaddr_port(sockaddr);
+	*has_port = true;
+}
+
+/* dnstap_log prepares dnstap message and sent it to fstrm */
+static int dnstap_log(kr_layer_t *ctx) {
+	const struct kr_request *req = ctx->req;
+	const struct kr_module *module = ctx->api->data;
+	const struct kr_rplan *rplan = &req->rplan;
+	const struct dnstap_data *dnstap_dt = module->data;
+
+	/* 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");
+		return kr_error(EFAULT);
+	}
+
+	/* current time */
+	struct timeval now;
+	gettimeofday(&now, NULL);
+
+	/* Create dnstap message */
+	Dnstap__Message m;
+
+	memset(&m, 0, sizeof(m));
+
+	m.base.descriptor = &dnstap__message__descriptor;
+	/* Only handling response */
+	m.type = DNSTAP__MESSAGE__TYPE__RESOLVER_RESPONSE;
+
+	if (req->qsource.addr) {
+		set_address(req->qsource.addr,
+				&m.query_address,
+				&m.has_query_address,
+				&m.query_port,
+				&m.has_query_port);
+	}
+
+	if (req->qsource.dst_addr) {
+		if (req->qsource.flags.tcp) {
+			m.socket_protocol = DNSTAP__SOCKET_PROTOCOL__TCP;
+		} else {
+			m.socket_protocol = DNSTAP__SOCKET_PROTOCOL__UDP;
+		}
+		m.has_socket_protocol = true;
+
+		set_address(req->qsource.dst_addr,
+				&m.response_address,
+				&m.has_response_address,
+				&m.response_port,
+				&m.has_response_port);
+		switch (req->qsource.dst_addr->sa_family) {
+			case AF_INET:
+				m.socket_family = DNSTAP__SOCKET_FAMILY__INET;
+				m.has_socket_family = true;
+				break;
+			case AF_INET6:
+				m.socket_family = DNSTAP__SOCKET_FAMILY__INET6;
+				m.has_socket_family = true;
+				break;
+		}
+	}
+
+	if (dnstap_dt->log_resp_pkt) {
+		const knot_pkt_t *rpkt = req->answer;
+		m.response_message.len = rpkt->size;
+		m.response_message.data = (uint8_t *)rpkt->wire;
+		m.has_response_message = true;
+	}
+
+	/* set query time to the timestamp of the first kr_query
+	 * set response time to now
+	 */
+	if (rplan->resolved.len > 0) {
+		struct kr_query *first = rplan->resolved.at[0];
+
+		m.query_time_sec = first->timestamp.tv_sec;
+		m.has_query_time_sec = true;
+		m.query_time_nsec = first->timestamp.tv_usec * 1000;
+		m.has_query_time_nsec = true;
+	}
+
+	/* Response time */
+	m.response_time_sec = now.tv_sec;
+	m.has_response_time_sec = true;
+	m.response_time_nsec = now.tv_usec * 1000;
+	m.has_response_time_nsec = true;
+
+	/* Query Zone */
+	if (rplan->resolved.len > 0) {
+		struct kr_query *last = array_tail(rplan->resolved);
+		/* Only add query_zone when not answered from cache */
+		if (!(last->flags.CACHED)) {
+			const knot_dname_t *zone_cut_name = last->zone_cut.name;
+			if (zone_cut_name != NULL) {
+				m.query_zone.data = (uint8_t *)zone_cut_name;
+				m.query_zone.len = knot_dname_size(zone_cut_name);
+				m.has_query_zone = true;
+			}
+		}
+	}
+
+	/* Create a dnstap Message */
+	Dnstap__Dnstap dnstap = DNSTAP__DNSTAP__INIT;
+	dnstap.type = DNSTAP__DNSTAP__TYPE__MESSAGE;
+	dnstap.message = (Dnstap__Message *)&m;
+
+	/* Pack the message */
+	uint8_t *frame = NULL;
+	size_t size = 0;
+	dt_pack(&dnstap, &frame, &size);
+	if (!frame) {
+		return kr_error(ENOMEM);
+	}
+
+	/* Submit a request to send message to fstrm_iothr*/
+	fstrm_res res = fstrm_iothr_submit(dnstap_dt->iothread, dnstap_dt->ioq, frame, size,
+			fstrm_free_wrapper, NULL);
+	if (res != fstrm_res_success) {
+		DEBUG_MSG("Error submitting dnstap message to iothr\n");
+		free(frame);
+		return kr_error(EBUSY);
+	}
+
+	return ctx->state;
+}
+
+KR_EXPORT
+int dnstap_init(struct kr_module *module) {
+	/* allocated memory for internal data */
+	struct dnstap_data *data = malloc(sizeof(*data));
+	if (!data) {
+		return kr_error(ENOMEM);
+	}
+	memset(data, 0, sizeof(*data));
+
+	/* save pointer to internal struct in module for future reference */
+	module->data = data;
+	return kr_ok();
+}
+
+KR_EXPORT
+int dnstap_deinit(struct kr_module *module) {
+	struct dnstap_data *data = module->data;
+	/* Free allocated memory */
+	if (data) {
+		fstrm_iothr_destroy(&data->iothread);
+		DEBUG_MSG("fstrm iothread destroyed\n");
+		free(data);
+	}
+	return kr_ok();
+}
+
+/* dnstap_unix_writer returns a unix fstream writer
+ * https://gitlab.labs.nic.cz/knot/knot-dns/blob/master/src/knot/modules/dnstap.c#L159
+ */
+static struct fstrm_writer* dnstap_unix_writer(const char *path) {
+
+	auto_destroy_uopts struct fstrm_unix_writer_options *opt = fstrm_unix_writer_options_init();
+	if (!opt) {
+		return NULL;
+	}
+	fstrm_unix_writer_options_set_socket_path(opt, path);
+
+	auto_destroy_wopts struct fstrm_writer_options *wopt = fstrm_writer_options_init();
+	if (!wopt) {
+		fstrm_unix_writer_options_destroy(&opt);
+		return NULL;
+	}
+	fstrm_writer_options_add_content_type(wopt, DNSTAP_CONTENT_TYPE,
+			strlen(DNSTAP_CONTENT_TYPE));
+
+	struct fstrm_writer *writer = fstrm_unix_writer_init(opt, wopt);
+	fstrm_unix_writer_options_destroy(&opt);
+	fstrm_writer_options_destroy(&wopt);
+	if (!writer) {
+		return NULL;
+	}
+
+	fstrm_res res = fstrm_writer_open(writer);
+	if (res != fstrm_res_success) {
+		DEBUG_MSG("fstrm_writer_open returned %d\n", res);
+		fstrm_writer_destroy(&writer);
+		return NULL;
+	}
+
+	return writer;
+}
+
+/* find_string 
+ * create a new string from json
+ * *var is set to pointer of new string
+ * node must of type JSON_STRING
+ * new string can be at most len bytes
+ */
+static int find_string(const JsonNode *node, char **val, size_t len) {
+	if (!node || !node->key) {
+		return kr_error(EINVAL);
+	}
+	assert(node->tag == JSON_STRING);
+	*val = strndup(node->string_, len);
+	assert(*val != NULL);
+	return kr_ok();
+}
+
+/* find_bool returns bool from json */
+static bool find_bool(const JsonNode *node) {
+	if (!node || !node->key) {
+		return false;
+	}
+	assert(node->tag == JSON_BOOL);
+	return node->bool_;
+}
+
+/* parse config */
+KR_EXPORT
+int dnstap_config(struct kr_module *module, const char *conf) {
+	struct dnstap_data *data = module->data;
+	auto_free char *sock_path = NULL;
+
+	/* Empty conf passed, set default */
+	if (!conf || strlen(conf) < 1) {
+		sock_path = strndup(DEFAULT_SOCK_PATH, PATH_MAX);
+	} else {
+
+		JsonNode *root_node = json_decode(conf);
+		if (!root_node) {
+			DEBUG_MSG("error parsing json\n");
+			return kr_error(EINVAL);
+		}
+
+		JsonNode *node;
+		/* dnstapPath key */
+		node = json_find_member(root_node, CFG_SOCK_PATH);
+		if (!node || find_string(node, &sock_path, PATH_MAX) != kr_ok()) {
+			sock_path = strndup(DEFAULT_SOCK_PATH, PATH_MAX);
+		}
+
+		/* logRespPkt key */
+		node = json_find_member(root_node, CFG_LOG_RESP_PKT);
+		if (node) {
+			data->log_resp_pkt = find_bool(node);
+		} else {
+			data->log_resp_pkt = false;
+		}
+
+		/* clean up json, we don't need it no more */
+		json_delete(root_node);
+	}
+
+	DEBUG_MSG("opening sock file %s\n",sock_path);
+	struct fstrm_writer *writer = dnstap_unix_writer(sock_path);
+	if (!writer) {
+		DEBUG_MSG("can't create unix writer\n");
+		return kr_error(EINVAL);
+	}
+
+	struct fstrm_iothr_options *opt = fstrm_iothr_options_init();
+	if (!opt) {
+		DEBUG_MSG("can't init fstrm options\n");
+		fstrm_writer_destroy(&writer);
+		return kr_error(EINVAL);
+	}
+
+	/* Create the I/O thread. */
+	data->iothread = fstrm_iothr_init(opt, &writer);
+	fstrm_iothr_options_destroy(&opt);
+	if (!data->iothread) {
+		DEBUG_MSG("can't init fstrm_iothr\n");
+		fstrm_writer_destroy(&writer);
+		return kr_error(ENOMEM);
+	}
+
+	/* Get fstrm thread handle
+	 * We only have one input queue, hence idx=0
+	 */
+	data->ioq = fstrm_iothr_get_input_queue_idx(data->iothread, 0);
+	if (!data->ioq) {
+		fstrm_iothr_destroy(&data->iothread);
+		DEBUG_MSG("can't get fstrm queue\n");
+		return kr_error(EBUSY);
+	}
+
+	return kr_ok();
+}
+
+KR_EXPORT
+const kr_layer_api_t *dnstap_layer(struct kr_module *module) {
+	static kr_layer_api_t _layer = {
+		.finish = &dnstap_log,
+	};
+	/* Store module reference */
+	_layer.data = module;
+	return &_layer;
+}
+
+KR_MODULE_EXPORT(dnstap)
+