add mDNS lookup method to libosmo-mslookup
Add the first actually useful lookup method to the mslookup library: multicast
DNS.
The server side is added in a subsequent commit, when the mslookup server is
implemented for the osmo-hlr program.
Use custom DNS encoding instead of libc-ares (which we use in OsmoSGSN
already), because libc-ares is only a DNS client implementation and we will
need both client and server.
Related: OS#4237
Patch-by: osmith, nhofmeyr
Change-Id: I03a0ffa1d4dc1b24ac78a5ad0975bca90a49c728
diff --git a/tests/mslookup/mslookup_client_mdns_test.c b/tests/mslookup/mslookup_client_mdns_test.c
new file mode 100644
index 0000000..6091e3c
--- /dev/null
+++ b/tests/mslookup/mslookup_client_mdns_test.c
@@ -0,0 +1,220 @@
+/* Copyright 2019 by sysmocom s.f.m.c. GmbH <info@sysmocom.de>
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <stdbool.h>
+#include <string.h>
+#include <unistd.h>
+#include <osmocom/core/select.h>
+#include <osmocom/core/application.h>
+#include <osmocom/hlr/logging.h>
+#include <osmocom/mslookup/mslookup.h>
+#include <osmocom/mslookup/mslookup_client.h>
+#include <osmocom/mslookup/mslookup_client_mdns.h>
+#include <osmocom/mslookup/mdns.h>
+#include <osmocom/mslookup/mdns_sock.h>
+
+void *ctx = NULL;
+
+#define TEST_IP OSMO_MSLOOKUP_MDNS_IP4
+#define TEST_PORT OSMO_MSLOOKUP_MDNS_PORT
+#define TEST_DOMAIN_SUFFIX "mslookup_client_mdns_test.dgsm.osmocom.org"
+
+/*
+ * Test server (emulates the mDNS server in OsmoHLR) and client
+ */
+struct osmo_mdns_sock *server_mc;
+
+
+static void server_reply(struct osmo_mslookup_query *query, uint16_t packet_id)
+{
+ struct osmo_mslookup_result result = {0};
+ struct msgb *msg;
+
+ result.rc = OSMO_MSLOOKUP_RC_RESULT;
+ result.age = 3;
+ osmo_sockaddr_str_from_str(&result.host_v4, "42.42.42.42", 444);
+ osmo_sockaddr_str_from_str(&result.host_v6, "1122:3344:5566:7788:99aa:bbcc:ddee:ff00", 666);
+
+ msg = osmo_mdns_result_encode(ctx, packet_id, query, &result, TEST_DOMAIN_SUFFIX);
+ OSMO_ASSERT(msg);
+ OSMO_ASSERT(osmo_mdns_sock_send(server_mc, msg) == 0);
+}
+
+static int server_recv(struct osmo_fd *osmo_fd, unsigned int what)
+{
+ int n;
+ uint8_t buffer[1024];
+ uint16_t packet_id;
+ struct osmo_mslookup_query *query;
+
+ fprintf(stderr, "%s\n", __func__);
+
+ /* Parse the message and print it */
+ n = read(osmo_fd->fd, buffer, sizeof(buffer));
+ OSMO_ASSERT(n >= 0);
+
+ query = osmo_mdns_query_decode(ctx, buffer, n, &packet_id, TEST_DOMAIN_SUFFIX);
+ if (!query)
+ return -1; /* server receiving own answer is expected */
+
+ fprintf(stderr, "received request\n");
+ server_reply(query, packet_id);
+ talloc_free(query);
+ return n;
+}
+
+static void server_init()
+{
+ fprintf(stderr, "%s\n", __func__);
+ server_mc = osmo_mdns_sock_init(ctx, TEST_IP, TEST_PORT, server_recv, NULL, 0);
+ OSMO_ASSERT(server_mc);
+}
+
+static void server_stop()
+{
+ fprintf(stderr, "%s\n", __func__);
+ OSMO_ASSERT(server_mc);
+ osmo_mdns_sock_cleanup(server_mc);
+ server_mc = NULL;
+}
+
+struct osmo_mslookup_client* client;
+struct osmo_mslookup_client_method* client_method;
+
+static void client_init()
+{
+ fprintf(stderr, "%s\n", __func__);
+ client = osmo_mslookup_client_new(ctx);
+ OSMO_ASSERT(client);
+ client_method = osmo_mslookup_client_add_mdns(client, TEST_IP, TEST_PORT, 1337, TEST_DOMAIN_SUFFIX);
+ OSMO_ASSERT(client_method);
+}
+
+static void client_recv(struct osmo_mslookup_client *client, uint32_t request_handle,
+ const struct osmo_mslookup_query *query, const struct osmo_mslookup_result *result)
+{
+ char buf[256];
+ fprintf(stderr, "%s\n", __func__);
+ fprintf(stderr, "client_recv(): %s\n", osmo_mslookup_result_name_b(buf, sizeof(buf), query, result));
+
+ osmo_mslookup_client_request_cancel(client, request_handle);
+}
+
+static void client_query()
+{
+ struct osmo_mslookup_id id = {.type = OSMO_MSLOOKUP_ID_IMSI,
+ .imsi = "123456789012345"};
+ const struct osmo_mslookup_query query = {
+ .service = "gsup.hlr",
+ .id = id,
+ };
+ struct osmo_mslookup_query_handling handling = {
+ .result_timeout_milliseconds = 2000,
+ .result_cb = client_recv,
+ };
+
+ fprintf(stderr, "%s\n", __func__);
+ osmo_mslookup_client_request(client, &query, &handling);
+}
+
+static void client_stop()
+{
+ fprintf(stderr, "%s\n", __func__);
+ osmo_mslookup_client_free(client);
+ client = NULL;
+}
+const struct timeval fake_time_start_time = { 0, 0 };
+
+#define fake_time_passes(secs, usecs) do \
+{ \
+ struct timeval diff; \
+ osmo_gettimeofday_override_add(secs, usecs); \
+ osmo_clock_override_add(CLOCK_MONOTONIC, secs, usecs * 1000); \
+ timersub(&osmo_gettimeofday_override_time, &fake_time_start_time, &diff); \
+ LOGP(DMSLOOKUP, LOGL_DEBUG, "Total time passed: %d.%06d s\n", \
+ (int)diff.tv_sec, (int)diff.tv_usec); \
+ osmo_timers_prepare(); \
+ osmo_timers_update(); \
+} while (0)
+
+static void fake_time_start()
+{
+ struct timespec *clock_override;
+
+ osmo_gettimeofday_override_time = fake_time_start_time;
+ osmo_gettimeofday_override = true;
+ clock_override = osmo_clock_override_gettimespec(CLOCK_MONOTONIC);
+ OSMO_ASSERT(clock_override);
+ clock_override->tv_sec = fake_time_start_time.tv_sec;
+ clock_override->tv_nsec = fake_time_start_time.tv_usec * 1000;
+ osmo_clock_override_enable(CLOCK_MONOTONIC, true);
+ fake_time_passes(0, 0);
+}
+static void test_server_client()
+{
+ fprintf(stderr, "-- %s --\n", __func__);
+ server_init();
+ client_init();
+ client_query();
+
+ /* Let the server receive the query and indirectly call server_recv(). As side effect of using the same IP and
+ * port, the client will also receive its own question. The client will dismiss its own question, as it is just
+ * looking for answers. */
+ OSMO_ASSERT(osmo_select_main_ctx(1) == 1);
+
+ /* Let the mslookup client receive the answer (also same side effect as above). It does not call the callback
+ * (client_recv()) just yet, because it is waiting for the best result within two seconds. */
+ OSMO_ASSERT(osmo_select_main_ctx(1) == 1);
+
+ /* Time flies by, client_recv() gets called. */
+ fake_time_passes(5, 0);
+
+ server_stop();
+ client_stop();
+}
+
+/*
+ * Run all tests
+ */
+int main()
+{
+ talloc_enable_null_tracking();
+ ctx = talloc_named_const(NULL, 0, "main");
+ osmo_init_logging2(ctx, NULL);
+
+ log_set_print_filename(osmo_stderr_target, 0);
+ log_set_print_level(osmo_stderr_target, 0);
+ log_set_print_category(osmo_stderr_target, 0);
+ log_set_print_category_hex(osmo_stderr_target, 0);
+ log_set_use_color(osmo_stderr_target, 0);
+ log_set_category_filter(osmo_stderr_target, DMSLOOKUP, true, LOGL_DEBUG);
+
+ fake_time_start();
+
+ test_server_client();
+
+ log_fini();
+
+ OSMO_ASSERT(talloc_total_blocks(ctx) == 1);
+ talloc_free(ctx);
+ OSMO_ASSERT(talloc_total_blocks(NULL) == 1);
+ talloc_disable_null_tracking();
+
+ return 0;
+}