/* Dummy implementation of a subscriber database, roghly HLR/VLR functionality */ /* (C) 2008 by Harald Welte * (C) 2009 by Holger Hans Peter Freyther * * All Rights Reserved * * 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 2 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, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. * */ #include #include #include #include #include #include #include #include #include #include #include LLIST_HEAD(active_subscribers); static void *tall_subscr_ctx; static void *tall_sub_req_ctx; /* * Struct for pending channel requests. This is managed in the * llist_head requests of each subscriber. The reference counting * should work in such a way that a subscriber with a pending request * remains in memory. */ struct subscr_request { struct llist_head entry; /* back reference */ struct gsm_subscriber *subscr; /* the requested channel type */ int channel_type; /* the bts we have decided to use */ struct gsm_network *network; /* the callback data */ gsm_cbfn *cbfn; void *param; }; /* * We got the channel assigned and can now hand this channel * over to one of our callbacks. */ static int subscr_paging_cb(unsigned int hooknum, unsigned int event, struct msgb *msg, void *data, void *param) { struct subscr_request *request; struct gsm_subscriber *subscr = (struct gsm_subscriber *)param; assert(!llist_empty(&subscr->requests)); /* * FIXME: What to do with paging requests coming during * this callback? We must be sure to not start paging when * we have an active connection to a subscriber and to make * the subscr_put_channel work as required... */ request = (struct subscr_request *)subscr->requests.next; llist_del(&request->entry); subscr->in_callback = 1; request->cbfn(hooknum, event, msg, data, request->param); subscr->in_callback = 0; talloc_free(request); return 0; } static void subscr_send_paging_request(struct gsm_subscriber *subscr) { struct subscr_request *request; assert(!llist_empty(&subscr->requests)); request = (struct subscr_request *)subscr->requests.next; paging_request(request->network, subscr, request->channel_type, subscr_paging_cb, subscr); } struct gsm_subscriber *subscr_alloc(void) { struct gsm_subscriber *s; if (!tall_subscr_ctx) tall_subscr_ctx = talloc_named_const(tall_bsc_ctx, 1, "subscriber"); s = talloc(tall_subscr_ctx, struct gsm_subscriber); if (!s) return NULL; memset(s, 0, sizeof(*s)); llist_add_tail(&s->entry, &active_subscribers); s->use_count = 1; INIT_LLIST_HEAD(&s->requests); return s; } static void subscr_free(struct gsm_subscriber *subscr) { llist_del(&subscr->entry); talloc_free(subscr); } struct gsm_subscriber *subscr_get_by_tmsi(const char *tmsi) { struct gsm_subscriber *subscr; /* we might have a record in memory already */ llist_for_each_entry(subscr, &active_subscribers, entry) { if (strcmp(subscr->tmsi, tmsi) == 0) return subscr_get(subscr); } return db_get_subscriber(GSM_SUBSCRIBER_TMSI, tmsi); } struct gsm_subscriber *subscr_get_by_imsi(const char *imsi) { struct gsm_subscriber *subscr; llist_for_each_entry(subscr, &active_subscribers, entry) { if (strcmp(subscr->imsi, imsi) == 0) return subscr_get(subscr); } return db_get_subscriber(GSM_SUBSCRIBER_IMSI, imsi); } struct gsm_subscriber *subscr_get_by_extension(const char *ext) { struct gsm_subscriber *subscr; llist_for_each_entry(subscr, &active_subscribers, entry) { if (strcmp(subscr->extension, ext) == 0) return subscr_get(subscr); } return db_get_subscriber(GSM_SUBSCRIBER_EXTENSION, ext); } int subscr_update(struct gsm_subscriber *s, struct gsm_bts *bts, int reason) { /* FIXME: Migrate pending requests from one BSC to another */ switch (reason) { case GSM_SUBSCRIBER_UPDATE_ATTACHED: /* Indicate "attached to LAC" */ s->lac = bts->location_area_code; break; case GSM_SUBSCRIBER_UPDATE_DETACHED: /* Only detach if we are currently in this area */ if (bts->location_area_code == s->lac) s->lac = 0; break; default: fprintf(stderr, "subscr_update with unknown reason: %d\n", reason); break; }; return db_sync_subscriber(s); } struct gsm_subscriber *subscr_get(struct gsm_subscriber *subscr) { subscr->use_count++; DEBUGP(DCC, "subscr %s usage increases usage to: %d\n", subscr->extension, subscr->use_count); return subscr; } struct gsm_subscriber *subscr_put(struct gsm_subscriber *subscr) { subscr->use_count--; DEBUGP(DCC, "subscr %s usage decreased usage to: %d\n", subscr->extension, subscr->use_count); if (subscr->use_count <= 0) subscr_free(subscr); return NULL; } void subscr_get_channel(struct gsm_subscriber *subscr, struct gsm_network *network, int type, gsm_cbfn *cbfn, void *param) { struct subscr_request *request; if (!tall_sub_req_ctx) tall_sub_req_ctx = talloc_named_const(tall_bsc_ctx, 1, "subscr_request"); request = talloc(tall_sub_req_ctx, struct subscr_request); if (!request) { if (cbfn) cbfn(GSM_HOOK_RR_PAGING, GSM_PAGING_OOM, NULL, NULL, param); return; } memset(request, 0, sizeof(*request)); request->network = network; request->subscr = subscr; request->channel_type = type; request->cbfn = cbfn; request->param = param; /* * FIXME: We might be able to assign more than one * channel, e.g. voice and SMS submit at the same * time. */ if (!subscr->in_callback && llist_empty(&subscr->requests)) { /* add to the list, send a request */ llist_add_tail(&request->entry, &subscr->requests); subscr_send_paging_request(subscr); } else { /* this will be picked up later, from subscr_put_channel */ llist_add_tail(&request->entry, &subscr->requests); } } void subscr_put_channel(struct gsm_lchan *lchan) { /* * FIXME: Continue with other requests now... by checking * the gsm_subscriber inside the gsm_lchan. Drop the ref count * of the lchan after having asked the next requestee to handle * the channel. */ /* * FIXME: is the lchan is of a different type we could still * issue an immediate assignment for another channel and then * close this one. */ /* * Currently we will drop the last ref of the lchan which * will result in a channel release on RSL and we will start * the paging. This should work most of the time as the MS * will listen to the paging requests before we timeout */ put_lchan(lchan); if (lchan->subscr && !llist_empty(&lchan->subscr->requests)) subscr_send_paging_request(lchan->subscr); }