| Harald Welte | ccceef8 | 2009-08-13 00:57:54 +0200 | [diff] [blame^] | 1 | /* SMS based token authentication for ad-hoc GSM networks */ |
| 2 | |
| 3 | /* (C) 2009 by Harald Welte <laforge@gnumonks.org> |
| 4 | * |
| 5 | * All Rights Reserved |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License as published by |
| 9 | * the Free Software Foundation; either version 2 of the License, or |
| 10 | * (at your option) any later version. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | * GNU General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License along |
| 18 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 19 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | */ |
| 22 | |
| 23 | #include <openbsc/signal.h> |
| 24 | #include <openbsc/gsm_data.h> |
| 25 | #include <openbsc/gsm_04_11.h> |
| 26 | #include <openbsc/gsm_04_08.h> |
| 27 | #include <openbsc/gsm_subscriber.h> |
| 28 | |
| 29 | #define TOKEN_SMS_TEXT "HAR 2009 GSM. Please visit http://127.0.0.1/ to register" |
| 30 | |
| 31 | static int token_subscr_cb(unsigned int subsys, unsigned int signal, |
| 32 | void *handler_data, void *signal_data) |
| 33 | { |
| 34 | struct gsm_subscriber *subscr = signal_data; |
| 35 | struct gsm_sms *sms; |
| 36 | |
| 37 | if (subscr->net->auth_policy != GSM_AUTH_POLICY_TOKEN) |
| 38 | return 0; |
| 39 | |
| 40 | switch (signal) { |
| 41 | case S_SUBSCR_FIRST_CONTACT: |
| 42 | /* we've seen this subscriber for the first time. */ |
| 43 | sms = sms_from_text(subscr, TOKEN_SMS_TEXT); |
| 44 | if (!sms) |
| 45 | return -ENOMEM; |
| 46 | gsm411_send_sms_subscr(subscr, sms); |
| 47 | break; |
| 48 | } |
| 49 | |
| 50 | return 0; |
| 51 | } |
| 52 | |
| 53 | static int token_sms_cb(unsigned int subsys, unsigned int signal, |
| 54 | void *handler_data, void *signal_data) |
| 55 | { |
| 56 | struct gsm_sms *sms = signal_data; |
| 57 | struct gsm_lchan *lchan; |
| 58 | u_int16_t rand[16]; |
| 59 | |
| 60 | if (signal != S_SMS_DELIVERED) |
| 61 | return 0; |
| 62 | |
| 63 | /* these are not the droids we've been looking for */ |
| 64 | if (!sms->receiver || |
| 65 | !(sms->receiver->flags & GSM_SUBSCRIBER_FIRST_CONTACT)) |
| 66 | return 0; |
| 67 | |
| 68 | if (sms->receiver->net->auth_policy != GSM_AUTH_POLICY_TOKEN) |
| 69 | return 0; |
| 70 | |
| 71 | lchan = lchan_for_subscr(sms->receiver); |
| 72 | if (lchan) { |
| 73 | /* kick the subscriber off the network */ |
| 74 | gsm48_tx_mm_auth_req(lchan, rand); |
| 75 | gsm48_tx_mm_auth_rej(lchan); |
| 76 | /* close the channel */ |
| 77 | //gsm48_send_rr_Release(lchan); |
| 78 | lchan_free(lchan); |
| 79 | } |
| 80 | |
| 81 | /* make sure we don't allow him in again unless he clicks the web UI */ |
| 82 | sms->receiver->authorized = 0; |
| 83 | db_sync_subscriber(sms->receiver); |
| 84 | |
| 85 | return 0; |
| 86 | } |
| 87 | |
| 88 | static __attribute__((constructor)) void on_dso_load_token(void) |
| 89 | { |
| 90 | register_signal_handler(SS_SUBSCR, token_subscr_cb, NULL); |
| 91 | register_signal_handler(SS_SMS, token_sms_cb, NULL); |
| 92 | } |