diff options
Diffstat (limited to 'openbsc/src/gsm_subscriber_base.c')
| -rw-r--r-- | openbsc/src/gsm_subscriber_base.c | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/openbsc/src/gsm_subscriber_base.c b/openbsc/src/gsm_subscriber_base.c new file mode 100644 index 000000000..dee89c0bc --- /dev/null +++ b/openbsc/src/gsm_subscriber_base.c @@ -0,0 +1,213 @@ +/* The concept of a subscriber as seen by the BSC */ + +/* (C) 2008 by Harald Welte <laforge@gnumonks.org> + * (C) 2009 by Holger Hans Peter Freyther <zecke@selfish.org> + * + * 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 <unistd.h> +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <assert.h> + +#include <osmocore/talloc.h> +#include <openbsc/gsm_subscriber.h> +#include <openbsc/paging.h> +#include <openbsc/debug.h> + +LLIST_HEAD(active_subscribers); +void *tall_subscr_ctx; +void *tall_sub_req_ctx; + +/* for the gsm_subscriber.c */ +struct llist_head *subscr_bsc_active_subscriber(void) +{ + return &active_subscribers; +} + +/* + * 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 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; + + /* There is no request anymore... */ + if (llist_empty(&subscr->requests)) + return -1; + + /* + * 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; + int rc; + + assert(!llist_empty(&subscr->requests)); + + request = (struct subscr_request *)subscr->requests.next; + rc = paging_request(subscr->net, subscr, request->channel_type, + subscr_paging_cb, subscr); + + /* paging failed, quit now */ + if (rc <= 0) { + subscr_paging_cb(GSM_HOOK_RR_PAGING, GSM_PAGING_EXPIRED, + NULL, NULL, request->param); + } +} + +struct gsm_subscriber *subscr_alloc(void) +{ + struct gsm_subscriber *s; + + s = talloc_zero(tall_subscr_ctx, struct gsm_subscriber); + if (!s) + return NULL; + + llist_add_tail(&s->entry, &active_subscribers); + s->use_count = 1; + s->tmsi = GSM_RESERVED_TMSI; + + 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(struct gsm_subscriber *subscr) +{ + subscr->use_count++; + DEBUGP(DREF, "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(DREF, "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, + int type, gsm_cbfn *cbfn, void *param) +{ + struct subscr_request *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->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); +} + |