move openbsc/* to repos root

This is the first step in creating this repository from the legacy openbsc.git.

Like all other Osmocom repositories, keep the autoconf and automake files in
the repository root. openbsc.git has been the sole exception, which ends now.

Change-Id: I9c6f2a448d9cb1cc088cf1cf6918b69d7e69b4e7

1 files changed, 160 insertions, 0 deletions

diff --git a/src/libmsc/token_auth.c b/src/libmsc/token_auth.c
new file mode 100644
index 000000000..5af1e980b
--- /dev/null
+++ b/src/libmsc/token_auth.c
@@ -0,0 +1,160 @@
+/* SMS based token authentication for ad-hoc GSM networks */
+
+/* (C) 2009 by Harald Welte <laforge@gnumonks.org>
+ *
+ * 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 <stdio.h>
+#include <osmocom/core/talloc.h>
+#include <openbsc/signal.h>
+#include <openbsc/gsm_data.h>
+#include <openbsc/gsm_04_11.h>
+#include <openbsc/gsm_04_08.h>
+#include <openbsc/gsm_subscriber.h>
+#include <openbsc/chan_alloc.h>
+#include <openbsc/db.h>
+
+#define TOKEN_SMS_TEXT "HAR 2009 GSM.  Register at http://har2009.gnumonks.org/ " \
+			"Your IMSI is %s, auth token is %08X, phone no is %s."
+
+static char *build_sms_string(struct gsm_subscriber *subscr, uint32_t token)
+{
+	char *sms_str;
+	unsigned int len;
+
+	len = strlen(subscr->imsi) + 8 + strlen(TOKEN_SMS_TEXT);
+	sms_str = talloc_size(tall_bsc_ctx, len);
+	if (!sms_str)
+		return NULL;
+
+	snprintf(sms_str, len, TOKEN_SMS_TEXT, subscr->imsi, token,
+		 subscr->extension);
+	sms_str[len-1] = '\0';
+
+	return sms_str;
+}
+
+static int token_subscr_cb(unsigned int subsys, unsigned int signal,
+			void *handler_data, void *signal_data)
+{
+	struct gsm_subscriber *subscr = signal_data;
+	struct gsm_sms *sms;
+	int rc = 0;
+
+	if (signal != S_SUBSCR_ATTACHED)
+		return 0;
+
+	if (subscr->group->net->auth_policy != GSM_AUTH_POLICY_TOKEN)
+		return 0;
+
+	if (subscr->flags & GSM_SUBSCRIBER_FIRST_CONTACT) {
+		struct gsm_subscriber *sender;
+		uint32_t token;
+		char *sms_str;
+
+		/* we've seen this subscriber for the first time. */
+		rc = db_subscriber_alloc_token(subscr, &token);
+		if (rc != 0) {
+			rc = -EIO;
+			goto unauth;
+		}
+
+		sms_str = build_sms_string(subscr, token);
+		if (!sms_str) {
+			rc = -ENOMEM;
+			goto unauth;
+		}
+
+
+		/* FIXME: don't use ID 1 static */
+		sender = subscr_get_by_id(subscr->group, 1);
+
+		sms = sms_from_text(subscr, sender, 0, sms_str);
+
+		subscr_put(sender);
+		talloc_free(sms_str);
+		if (!sms) {
+			rc = -ENOMEM;
+			goto unauth;
+		}
+
+		rc = gsm411_send_sms_subscr(subscr, sms);
+
+		/* FIXME: else, delete the subscirber from database */
+unauth:
+
+		/* make sure we don't allow him in again unless he clicks the web UI */
+		subscr->authorized = 0;
+		db_sync_subscriber(subscr);
+		if (rc) {
+			struct gsm_subscriber_connection *conn = connection_for_subscr(subscr);
+			if (conn) {
+				uint8_t auth_rand[16];
+				/* kick the subscriber off the network */
+				gsm48_tx_mm_auth_req(conn, auth_rand, NULL, 0);
+				gsm48_tx_mm_auth_rej(conn);
+				/* FIXME: close the channel early ?*/
+				//gsm48_send_rr_Release(lchan);
+			}
+		}
+	}
+
+	return rc;
+}
+
+static int token_sms_cb(unsigned int subsys, unsigned int signal,
+			void *handler_data, void *signal_data)
+{
+	struct sms_signal_data *sig = signal_data;
+	struct gsm_sms *sms = sig->sms;;
+	struct gsm_subscriber_connection *conn;
+	uint8_t auth_rand[16];
+
+
+	if (signal != S_SMS_DELIVERED)
+		return 0;
+
+
+	/* these are not the droids we've been looking for */
+	if (!sms->receiver ||
+	    !(sms->receiver->flags & GSM_SUBSCRIBER_FIRST_CONTACT))
+		return 0;
+
+
+	if (sms->receiver->group->net->auth_policy != GSM_AUTH_POLICY_TOKEN)
+		return 0;
+
+
+	conn = connection_for_subscr(sms->receiver);
+	if (conn) {
+		/* kick the subscriber off the network */
+		gsm48_tx_mm_auth_req(conn, auth_rand, NULL, 0);
+		gsm48_tx_mm_auth_rej(conn);
+		/* FIXME: close the channel early ?*/
+		//gsm48_send_rr_Release(lchan);
+	}
+
+	return 0;
+}
+
+//static __attribute__((constructor)) void on_dso_load_token(void)
+void on_dso_load_token(void)
+{
+	osmo_signal_register_handler(SS_SUBSCR, token_subscr_cb, NULL);
+	osmo_signal_register_handler(SS_SMS, token_sms_cb, NULL);
+}