| /* |
| * (C) 2019 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de> |
| * All Rights Reserved |
| * |
| * SPDX-License-Identifier: AGPL-3.0+ |
| * |
| * 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 <http://www.gnu.org/licenses/>. |
| */ |
| |
| #include <osmocom/msc/gsm_data.h> |
| #include <osmocom/msc/paging.h> |
| #include <osmocom/msc/vlr.h> |
| #include <osmocom/msc/ran_peer.h> |
| #include <osmocom/msc/sgs_iface.h> |
| #include <osmocom/msc/signal.h> |
| #include <osmocom/msc/msc_a.h> |
| #include <osmocom/msc/transaction.h> |
| |
| #define LOG_PAGING(vsub, paging_request, level, fmt, args ...) \ |
| LOGP(DPAG, level, "Paging: %s%s%s: " fmt, \ |
| vlr_subscr_name(vsub), paging_request ? " for " : "", paging_request ? (paging_request)->label : "", ## args) |
| |
| #define VSUB_USE_PAGING "Paging" |
| |
| const struct value_string paging_cause_names[] = { |
| { PAGING_CAUSE_CALL_CONVERSATIONAL, "CALL_CONVERSATIONAL" }, |
| { PAGING_CAUSE_CALL_STREAMING, "CALL_STREAMING" }, |
| { PAGING_CAUSE_CALL_INTERACTIVE, "CALL_INTERACTIVE" }, |
| { PAGING_CAUSE_CALL_BACKGROUND, "CALL_BACKGROUND" }, |
| { PAGING_CAUSE_SIGNALLING_LOW_PRIO, "SIGNALLING_LOW_PRIO" }, |
| { PAGING_CAUSE_SIGNALLING_HIGH_PRIO, "SIGNALLING_HIGH_PRIO" }, |
| { PAGING_CAUSE_UNSPECIFIED, "UNSPECIFIED" }, |
| {} |
| }; |
| |
| static void paging_response_timer_cb(void *data) |
| { |
| struct vlr_subscr *vsub = data; |
| |
| if (vsub->cs.attached_via_ran == OSMO_RAT_EUTRAN_SGS) |
| sgs_iface_tx_serv_abrt(vsub); |
| |
| paging_expired(vsub); |
| } |
| |
| /* Execute a paging on the currently active RAN. Returns the number of |
| * delivered paging requests or -EINVAL in case of failure. */ |
| static int msc_paging_request(struct paging_request *pr, struct vlr_subscr *vsub) |
| { |
| struct gsm_network *net = vsub->vlr->user_ctx; |
| |
| /* The subscriber was last seen in subscr->lac. Find out which |
| * BSCs/RNCs are responsible and send them a paging request via open |
| * SCCP connections (if any). */ |
| switch (vsub->cs.attached_via_ran) { |
| case OSMO_RAT_GERAN_A: |
| return ran_peers_down_paging(net->a.sri, CELL_IDENT_LAC, vsub, pr->cause); |
| case OSMO_RAT_UTRAN_IU: |
| return ran_peers_down_paging(net->iu.sri, CELL_IDENT_LAC, vsub, pr->cause); |
| case OSMO_RAT_EUTRAN_SGS: |
| return sgs_iface_tx_paging(vsub, sgs_serv_ind_from_paging_cause(pr->cause)); |
| default: |
| LOG_PAGING(vsub, pr, LOGL_ERROR, "Cannot page, subscriber not attached\n"); |
| return -EINVAL; |
| } |
| } |
| |
| struct paging_request *paging_request_start(struct vlr_subscr *vsub, enum paging_cause cause, |
| paging_cb_t paging_cb, struct gsm_trans *trans, |
| const char *label) |
| { |
| int rc; |
| struct paging_request *pr; |
| int paging_response_timer; |
| |
| pr = talloc(vsub, struct paging_request); |
| OSMO_ASSERT(pr); |
| *pr = (struct paging_request){ |
| .label = label, |
| .cause = cause, |
| .paging_cb = paging_cb, |
| .trans = trans, |
| }; |
| |
| if (vsub->cs.is_paging) { |
| LOG_PAGING(vsub, pr, LOGL_DEBUG, "Already paging, not starting another request\n"); |
| } else { |
| LOG_PAGING(vsub, pr, LOGL_DEBUG, "Starting paging\n"); |
| |
| rc = msc_paging_request(pr, vsub); |
| if (rc <= 0) { |
| LOG_PAGING(vsub, pr, LOGL_ERROR, "Starting paging failed (rc=%d)\n", rc); |
| talloc_free(pr); |
| return NULL; |
| } |
| |
| /* reduced on the first paging callback */ |
| vlr_subscr_get(vsub, VSUB_USE_PAGING); |
| vsub->cs.is_paging = true; |
| paging_response_timer = osmo_tdef_get(msc_ran_infra[vsub->cs.attached_via_ran].tdefs, -4, OSMO_TDEF_S, 10); |
| osmo_timer_setup(&vsub->cs.paging_response_timer, paging_response_timer_cb, vsub); |
| osmo_timer_schedule(&vsub->cs.paging_response_timer, paging_response_timer, 0); |
| } |
| |
| llist_add_tail(&pr->entry, &vsub->cs.requests); |
| |
| return pr; |
| } |
| |
| /* Two subscribers (e.g. an old TMSI and a new TMSI) turn out to have the same identity, so in order to discard one of |
| * them, transfer any pending Paging requests to the vsub that will survive. */ |
| void paging_request_join_vsub(struct vlr_subscr *keep_vsub, struct vlr_subscr *discarding_vsub) |
| { |
| struct paging_request *pr; |
| |
| if (!discarding_vsub->cs.is_paging) |
| return; |
| |
| /* transfer all Paging Response callbacks */ |
| while ((pr = llist_first_entry_or_null(&discarding_vsub->cs.requests, struct paging_request, entry))) { |
| llist_del(&pr->entry); |
| talloc_steal(keep_vsub, pr); |
| llist_add_tail(&pr->entry, &keep_vsub->cs.requests); |
| } |
| |
| /* make sure a Paging use count is present on keep_vsub, if needed */ |
| if (!keep_vsub->cs.is_paging && !llist_empty(&keep_vsub->cs.requests)) { |
| vlr_subscr_get(keep_vsub, VSUB_USE_PAGING); |
| keep_vsub->cs.is_paging = true; |
| } |
| |
| /* Already made sure at the top of this function that discarding_vsub->cs.is_paging == true */ |
| discarding_vsub->cs.is_paging = false; |
| osmo_timer_del(&discarding_vsub->cs.paging_response_timer); |
| vlr_subscr_put(discarding_vsub, VSUB_USE_PAGING); |
| } |
| |
| void paging_request_remove(struct paging_request *pr) |
| { |
| struct gsm_trans *trans = pr->trans; |
| struct vlr_subscr *vsub = trans ? trans->vsub : NULL; |
| LOG_PAGING(vsub, pr, LOGL_DEBUG, "Removing Paging Request\n"); |
| |
| if (pr->trans && pr->trans->paging_request == pr) |
| pr->trans->paging_request = NULL; |
| |
| llist_del(&pr->entry); |
| talloc_free(pr); |
| } |
| |
| static void paging_concludes(struct vlr_subscr *vsub, struct msc_a *msc_a) |
| { |
| struct paging_request *pr, *pr_next; |
| struct paging_signal_data sig_data; |
| |
| if (!vsub) { |
| /* A Paging Response has no subscriber. (Related: OS#4449) */ |
| return; |
| } |
| |
| osmo_timer_del(&vsub->cs.paging_response_timer); |
| |
| llist_for_each_entry_safe(pr, pr_next, &vsub->cs.requests, entry) { |
| struct gsm_trans *trans = pr->trans; |
| paging_cb_t paging_cb = pr->paging_cb; |
| |
| LOG_PAGING(vsub, pr, LOGL_DEBUG, "Paging Response action (%s)%s\n", |
| msc_a ? "success" : "expired", |
| paging_cb ? "" : " (no action defined)"); |
| |
| /* Remove the paging request before the paging_cb could deallocate e.g. the trans */ |
| paging_request_remove(pr); |
| pr = NULL; |
| |
| if (paging_cb) |
| paging_cb(msc_a, trans); |
| } |
| |
| /* Inform parts of the system we don't know */ |
| sig_data = (struct paging_signal_data){ |
| .vsub = vsub, |
| .msc_a = msc_a, |
| }; |
| osmo_signal_dispatch(SS_PAGING, msc_a ? S_PAGING_SUCCEEDED : S_PAGING_EXPIRED, &sig_data); |
| |
| /* balanced with the moment we start paging */ |
| if (vsub->cs.is_paging) { |
| vsub->cs.is_paging = false; |
| vlr_subscr_put(vsub, VSUB_USE_PAGING); |
| } |
| |
| /* Handling of the paging requests has usually added transactions, which keep the msc_a connection active. If |
| * there are none, then this probably marks release of the connection. */ |
| if (msc_a) |
| msc_a_put(msc_a, MSC_A_USE_PAGING_RESPONSE); |
| } |
| |
| void paging_response(struct msc_a *msc_a) |
| { |
| paging_concludes(msc_a_vsub(msc_a), msc_a); |
| } |
| |
| void paging_expired(struct vlr_subscr *vsub) |
| { |
| paging_concludes(vsub, NULL); |
| } |