bsc/mminfo: Patch timezone and DST in MM Info messages

This adds in-place patching of the time information in the
MM INFORMATION message. The timezone in the 'Local time zone' and
the 'Universal time and local time zone' information elements
and the offset in the 'Network Daylight Saving Time' information
element are optionally set.

The new values are determined by the 'timezone' vty command in the
config_net_bts node. That command is extended by an optional
DST offset parameter.

Tests are provided for the vty part and for the plain
bsc_scan_msc_msg() function.

Sponsored-by: On-Waves ehf
Ticket: OW#978
diff --git a/openbsc/tests/bsc/bsc_test.c b/openbsc/tests/bsc/bsc_test.c
new file mode 100644
index 0000000..881c785
--- /dev/null
+++ b/openbsc/tests/bsc/bsc_test.c
@@ -0,0 +1,204 @@
+/*
+ * BSC Message filtering
+ *
+ * (C) 2013 by sysmocom s.f.m.c. GmbH
+ * Written by Jacob Erlbeck <jerlbeck@sysmocom.de>
+ * (C) 2010-2013 by Holger Hans Peter Freyther <zecke@selfish.org>
+ * (C) 2010-2013 by On-Waves
+ *
+ * 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 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 <openbsc/debug.h>
+#include <openbsc/gsm_data.h>
+
+#include <openbsc/osmo_bsc.h>
+#include <openbsc/osmo_msc_data.h>
+#include <openbsc/gsm_04_80.h>
+#include <openbsc/gsm_subscriber.h>
+
+#include <osmocom/core/application.h>
+#include <osmocom/core/backtrace.h>
+#include <osmocom/core/talloc.h>
+
+#include <stdio.h>
+#include <search.h>
+
+enum test {
+	TEST_SCAN_TO_BTS,
+	TEST_SCAN_TO_MSC,
+};
+
+/* GSM 04.08 MM INFORMATION test message */
+static uint8_t gsm48_mm_info_nn_tzt[] = {
+	0x05, 0x32, 0x45, 0x08, 0x80, 0x4f, 0x77, 0xeb,
+	0x1a, 0xb6, 0x97, 0xe7, 0x47, 0x31, 0x90, 0x61,
+	0x11, 0x02, 0x73, 0x00,
+};
+
+static uint8_t gsm48_mm_info_nn_tzt_out[] = {
+	0x05, 0x32, 0x45, 0x08, 0x80, 0x4f, 0x77, 0xeb,
+	0x1a, 0xb6, 0x97, 0xe7, 0x47, 0x31, 0x90, 0x61,
+	0x11, 0x02, 0x73, 0x1a,
+};
+
+static uint8_t gsm48_mm_info_nn_tzt_dst[] = {
+	0x05, 0x32, 0x45, 0x08, 0x80, 0x4f, 0x77, 0xeb,
+	0x1a, 0xb6, 0x97, 0xe7, 0x47, 0x31, 0x90, 0x61,
+	0x11, 0x02, 0x73, 0x00, 0x49, 0x01, 0x00,
+};
+
+static uint8_t gsm48_mm_info_nn_tzt_dst_out[] = {
+	0x05, 0x32, 0x45, 0x08, 0x80, 0x4f, 0x77, 0xeb,
+	0x1a, 0xb6, 0x97, 0xe7, 0x47, 0x31, 0x90, 0x61,
+	0x11, 0x02, 0x73, 0x1a, 0x49, 0x01, 0x02,
+};
+
+struct test_definition {
+	const uint8_t *data;
+	const uint16_t length;
+	const int dir;
+	const int result;
+	const uint8_t *out_data;
+	const uint16_t out_length;
+	const char* params;
+	const int n_params;
+};
+
+static int get_int(const char *params, size_t nmemb, const char *key, int def, int *is_set)
+{
+	const char *kv = NULL;
+
+	kv = strstr(params, key);
+	if (kv) {
+		kv += strlen(key) + 1;
+		fprintf(stderr, "get_int(%s) -> %d\n", key, atoi(kv));
+		if (is_set)
+			*is_set = 1;
+	}
+
+	return kv ? atoi(kv) : def;
+}
+
+static const struct test_definition test_scan_defs[] = {
+	{
+		.data = gsm48_mm_info_nn_tzt_dst,
+		.length = ARRAY_SIZE(gsm48_mm_info_nn_tzt),
+		.dir = TEST_SCAN_TO_BTS,
+		.result = 0,
+		.out_data = gsm48_mm_info_nn_tzt_dst_out,
+		.out_length = ARRAY_SIZE(gsm48_mm_info_nn_tzt_out),
+		.params = "tz_hr=-5 tz_mn=15 tz_dst=2",
+		.n_params = 3,
+	},
+	{
+		.data = gsm48_mm_info_nn_tzt_dst,
+		.length = ARRAY_SIZE(gsm48_mm_info_nn_tzt_dst),
+		.dir = TEST_SCAN_TO_BTS,
+		.result = 0,
+		.out_data = gsm48_mm_info_nn_tzt_dst_out,
+		.out_length = ARRAY_SIZE(gsm48_mm_info_nn_tzt_dst_out),
+		.params = "tz_hr=-5 tz_mn=15 tz_dst=2",
+		.n_params = 3,
+	},
+};
+
+static void test_scan(void)
+{
+	int i;
+
+	struct gsm_network *net;
+	struct gsm_bts *bts;
+	struct osmo_bsc_sccp_con *sccp_con;
+	struct osmo_msc_data *msc;
+	struct gsm_subscriber_connection *conn;
+
+	net = talloc_zero(NULL, struct gsm_network);
+	bts = talloc_zero(net, struct gsm_bts);
+	sccp_con = talloc_zero(net, struct osmo_bsc_sccp_con);
+	msc = talloc_zero(net, struct osmo_msc_data);
+	conn = talloc_zero(net, struct gsm_subscriber_connection);
+
+	bts->network = net;
+	sccp_con->msc = msc;
+	conn->bts = bts;
+	conn->sccp_con = sccp_con;
+
+	/* start testinh with proper messages */
+	printf("Testing BTS<->MSC message scan.\n");
+	for (i = 0; i < ARRAY_SIZE(test_scan_defs); ++i) {
+		const struct test_definition *test_def = &test_scan_defs[i];
+		int result;
+		struct msgb *msg = msgb_alloc(4096, "test-message");
+		int is_set = 0;
+
+		bts->tz.hr = get_int(test_def->params, test_def->n_params, "tz_hr", 0, &is_set);
+		bts->tz.mn = get_int(test_def->params, test_def->n_params, "tz_mn", 0, &is_set);
+		bts->tz.dst = get_int(test_def->params, test_def->n_params, "tz_dst", 0, &is_set);
+		bts->tz.override = get_int(test_def->params, test_def->n_params, "tz_dst", is_set ? 1 : 0, NULL);
+
+		printf("Going to test item: %d\n", i);
+		msg->l3h = msgb_put(msg, test_def->length);
+		memcpy(msg->l3h, test_def->data, test_def->length);
+
+		switch (test_def->dir) {
+		case TEST_SCAN_TO_BTS:
+			result = bsc_scan_msc_msg(conn, msg);
+			break;
+		case TEST_SCAN_TO_MSC:
+			result = bsc_scan_msc_msg(conn, msg);
+			break;
+		default:
+			abort();
+			break;
+		}
+
+		if (result != test_def->result) {
+			printf("FAIL: Not the expected result, got: %d wanted: %d\n",
+				result, test_def->result);
+			goto out;
+		}
+
+		if (msgb_l3len(msg) != test_def->out_length) {
+			printf("FAIL: Not the expected message size, got: %d wanted: %d\n",
+				msgb_l3len(msg), test_def->out_length);
+			goto out;
+		}
+
+		if (memcmp(msgb_l3(msg), test_def->out_data, test_def->out_length) != 0) {
+			printf("FAIL: Not the expected message\n");
+			goto out;
+		}
+
+out:
+		msgb_free(msg);
+	}
+
+	talloc_free(net);
+}
+
+
+int main(int argc, char **argv)
+{
+	osmo_init_logging(&log_info);
+
+	test_scan();
+
+	printf("Testing execution completed.\n");
+	return 0;
+}