diff --git a/include/osmocom/bsc/Makefile.am b/include/osmocom/bsc/Makefile.am index b99607042..924711999 100644 --- a/include/osmocom/bsc/Makefile.am +++ b/include/osmocom/bsc/Makefile.am @@ -49,4 +49,5 @@ noinst_HEADERS = \ ussd.h \ vty.h \ bsc_api.h \ + penalty_timers.h \ $(NULL) diff --git a/include/osmocom/bsc/gsm_data.h b/include/osmocom/bsc/gsm_data.h index 3da4fff6f..b8f8f81f8 100644 --- a/include/osmocom/bsc/gsm_data.h +++ b/include/osmocom/bsc/gsm_data.h @@ -79,13 +79,6 @@ struct gsm_classmark { uint8_t classmark3[14]; /* if cm3 gets extended by spec, it will be truncated */ }; -/* penalty timers for handover */ -struct ho_penalty_timer { - struct llist_head entry; - uint8_t bts; - time_t timeout; -}; - /* active radio connection of a mobile subscriber */ struct gsm_subscriber_connection { /* global linked list of subscriber_connections */ @@ -117,8 +110,7 @@ struct gsm_subscriber_connection { struct llist_head ho_dtap_cache; unsigned int ho_dtap_cache_len; - /* penalty timers for handover */ - struct llist_head ho_penalty_timers; + struct penalty_timers *ho_penalty_timers; }; diff --git a/include/osmocom/bsc/penalty_timers.h b/include/osmocom/bsc/penalty_timers.h new file mode 100644 index 000000000..4b1dcce55 --- /dev/null +++ b/include/osmocom/bsc/penalty_timers.h @@ -0,0 +1,36 @@ +/* Manage a list of penalty timers per BTS; + * initially used by handover algorithm 2 to keep per-BTS timers for each subscriber connection. */ +#pragma once + +/* Opaque struct to manage penalty timers */ +struct penalty_timers; + +/* Initialize a list of penalty timers. + * param ctx: talloc context to allocate in. + * returns an empty struct penalty_timers. */ +struct penalty_timers *penalty_timers_init(void *ctx); + +/* Add a penalty timer for a BTS. + * param pt: penalty timers list as from penalty_timers_init(). + * param for_object: arbitrary pointer reference to store a penalty timer for (passing NULL is possible, + * but note that penalty_timers_clear() will clear all timers if given for_object=NULL). + * param timeout: penalty time in seconds. */ +void penalty_timers_add(struct penalty_timers *pt, void *for_object, int timeout); + +/* Return the amount of penalty time remaining for a BTS. + * param pt: penalty timers list as from penalty_timers_init(). + * param for_object: arbitrary pointer reference to query penalty timers for. + * returns seconds remaining until all penalty time has expired. */ +unsigned int penalty_timers_remaining(struct penalty_timers *pt, void *for_object); + +/* Clear penalty timers for one or all BTS. + * param pt: penalty timers list as from penalty_timers_init(). + * param for_object: arbitrary pointer reference to clear penalty time for, + * or NULL to clear all timers. */ +void penalty_timers_clear(struct penalty_timers *pt, void *for_object); + +/* Free a struct as returned from penalty_timers_init(). + * Clear all timers from the list, deallocate the list and set the pointer to NULL. + * param pt: pointer-to-pointer which references a struct penalty_timers as returned by + * penalty_timers_init(); *pt_p will be set to NULL. */ +void penalty_timers_free(struct penalty_timers **pt_p); diff --git a/src/libbsc/Makefile.am b/src/libbsc/Makefile.am index e8e69c7a4..81b7a662f 100644 --- a/src/libbsc/Makefile.am +++ b/src/libbsc/Makefile.am @@ -59,5 +59,6 @@ libbsc_a_SOURCES = \ bts_ipaccess_nanobts_omlattr.c \ handover_vty.c \ handover_cfg.c \ + penalty_timers.c \ $(NULL) diff --git a/src/libbsc/bsc_api.c b/src/libbsc/bsc_api.c index d81bf0db0..2cb5b1032 100644 --- a/src/libbsc/bsc_api.c +++ b/src/libbsc/bsc_api.c @@ -31,6 +31,7 @@ #include #include #include +#include #include #include @@ -276,7 +277,7 @@ struct gsm_subscriber_connection *bsc_subscr_con_allocate(struct gsm_lchan *lcha conn->lchan = lchan; lchan->conn = conn; INIT_LLIST_HEAD(&conn->ho_dtap_cache); - INIT_LLIST_HEAD(&conn->ho_penalty_timers); + conn->ho_penalty_timers = penalty_timers_init(conn); llist_add_tail(&conn->entry, &net->subscr_conns); return conn; } @@ -326,8 +327,6 @@ static void ho_dtap_cache_flush(struct gsm_subscriber_connection *conn, int send void bsc_subscr_con_free(struct gsm_subscriber_connection *conn) { - struct ho_penalty_timer *penalty; - if (!conn) return; @@ -352,12 +351,7 @@ void bsc_subscr_con_free(struct gsm_subscriber_connection *conn) /* drop pending messages */ ho_dtap_cache_flush(conn, 0); - /* flush handover penalty timers */ - while ((penalty = llist_first_entry_or_null(&conn->ho_penalty_timers, - struct ho_penalty_timer, entry))) { - llist_del(&penalty->entry); - talloc_free(penalty); - } + penalty_timers_free(&conn->ho_penalty_timers); llist_del(&conn->entry); talloc_free(conn); diff --git a/src/libbsc/penalty_timers.c b/src/libbsc/penalty_timers.c new file mode 100644 index 000000000..b80fec946 --- /dev/null +++ b/src/libbsc/penalty_timers.c @@ -0,0 +1,129 @@ +/* (C) 2018 by sysmocom - s.f.m.c. GmbH + * + * All Rights Reserved + * + * Author: Neels Hofmeyr + * + * 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 . + * + */ + +#include +#include +#include + +#include + +#include +#include + +struct penalty_timers { + struct llist_head timers; +}; + +struct penalty_timer { + struct llist_head entry; + void *for_object; + unsigned int timeout; +}; + +static unsigned int time_now(void) +{ + time_t now; + time(&now); + /* FIXME: use monotonic clock */ + return (unsigned int)now; +} + +struct penalty_timers *penalty_timers_init(void *ctx) +{ + struct penalty_timers *pt = talloc_zero(ctx, struct penalty_timers); + if (!pt) + return NULL; + INIT_LLIST_HEAD(&pt->timers); + return pt; +} + +void penalty_timers_add(struct penalty_timers *pt, void *for_object, int timeout) +{ + struct penalty_timer *timer; + unsigned int now; + unsigned int then; + now = time_now(); + + if (timeout <= 0) + return; + + then = now + timeout; + + /* timer already running for that BTS? */ + llist_for_each_entry(timer, &pt->timers, entry) { + if (timer->for_object != for_object) + continue; + /* raise, if running timer will timeout earlier or has timed + * out already, otherwise keep later timeout */ + if (timer->timeout < then) + timer->timeout = then; + return; + } + + /* add new timer */ + timer = talloc_zero(pt, struct penalty_timer); + if (!timer) + return; + + timer->for_object = for_object; + timer->timeout = then; + + llist_add_tail(&timer->entry, &pt->timers); +} + +unsigned int penalty_timers_remaining(struct penalty_timers *pt, void *for_object) +{ + struct penalty_timer *timer; + unsigned int now = time_now(); + unsigned int max_remaining = 0; + llist_for_each_entry(timer, &pt->timers, entry) { + unsigned int remaining; + if (timer->for_object != for_object) + continue; + if (now >= timer->timeout) + continue; + remaining = timer->timeout - now; + if (remaining > max_remaining) + max_remaining = remaining; + } + return max_remaining; +} + +void penalty_timers_clear(struct penalty_timers *pt, void *for_object) +{ + struct penalty_timer *timer, *timer2; + llist_for_each_entry_safe(timer, timer2, &pt->timers, entry) { + if (for_object && timer->for_object != for_object) + continue; + llist_del(&timer->entry); + talloc_free(timer); + } +} + +void penalty_timers_free(struct penalty_timers **pt_p) +{ + struct penalty_timers *pt = *pt_p; + if (!pt) + return; + penalty_timers_clear(pt, NULL); + talloc_free(pt); + *pt_p = NULL; +}