Neels Hofmeyr | c4628a3 | 2018-12-07 14:47:34 +0100 | [diff] [blame] | 1 | /* |
| 2 | * (C) 2019 by sysmocom - s.m.f.c. GmbH <info@sysmocom.de> |
| 3 | * All Rights Reserved |
| 4 | * |
| 5 | * SPDX-License-Identifier: AGPL-3.0+ |
| 6 | * |
| 7 | * Author: Neels Hofmeyr |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or modify |
| 10 | * it under the terms of the GNU Affero General Public License as published by |
| 11 | * the Free Software Foundation; either version 3 of the License, or |
| 12 | * (at your option) any later version. |
| 13 | * |
| 14 | * This program is distributed in the hope that it will be useful, |
| 15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 17 | * GNU Affero General Public License for more details. |
| 18 | * |
| 19 | * You should have received a copy of the GNU Affero General Public License |
| 20 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 21 | */ |
| 22 | |
| 23 | #include <osmocom/msc/gsm_data.h> |
| 24 | #include <osmocom/msc/paging.h> |
| 25 | #include <osmocom/msc/vlr.h> |
| 26 | #include <osmocom/msc/ran_peer.h> |
| 27 | #include <osmocom/msc/sgs_iface.h> |
| 28 | #include <osmocom/msc/signal.h> |
| 29 | #include <osmocom/msc/msc_a.h> |
| 30 | #include <osmocom/msc/transaction.h> |
| 31 | |
| 32 | #define LOG_PAGING(vsub, paging_request, level, fmt, args ...) \ |
| 33 | LOGP(DPAG, level, "Paging: %s%s%s: " fmt, \ |
| 34 | vlr_subscr_name(vsub), paging_request ? " for " : "", paging_request ? (paging_request)->label : "", ## args) |
| 35 | |
| 36 | #define VSUB_USE_PAGING "Paging" |
| 37 | |
| 38 | const struct value_string paging_cause_names[] = { |
| 39 | { PAGING_CAUSE_CALL_CONVERSATIONAL, "CALL_CONVERSATIONAL" }, |
| 40 | { PAGING_CAUSE_CALL_STREAMING, "CALL_STREAMING" }, |
| 41 | { PAGING_CAUSE_CALL_INTERACTIVE, "CALL_INTERACTIVE" }, |
| 42 | { PAGING_CAUSE_CALL_BACKGROUND, "CALL_BACKGROUND" }, |
| 43 | { PAGING_CAUSE_SIGNALLING_LOW_PRIO, "SIGNALLING_LOW_PRIO" }, |
| 44 | { PAGING_CAUSE_SIGNALLING_HIGH_PRIO, "SIGNALLING_HIGH_PRIO" }, |
| 45 | { PAGING_CAUSE_UNSPECIFIED, "UNSPECIFIED" }, |
| 46 | {} |
| 47 | }; |
| 48 | |
| 49 | static void paging_response_timer_cb(void *data) |
| 50 | { |
| 51 | struct vlr_subscr *vsub = data; |
| 52 | paging_expired(vsub); |
| 53 | } |
| 54 | |
| 55 | /* Execute a paging on the currently active RAN. Returns the number of |
| 56 | * delivered paging requests or -EINVAL in case of failure. */ |
| 57 | static int msc_paging_request(struct paging_request *pr, struct vlr_subscr *vsub) |
| 58 | { |
| 59 | struct gsm_network *net = vsub->vlr->user_ctx; |
| 60 | |
| 61 | /* The subscriber was last seen in subscr->lac. Find out which |
| 62 | * BSCs/RNCs are responsible and send them a paging request via open |
| 63 | * SCCP connections (if any). */ |
| 64 | switch (vsub->cs.attached_via_ran) { |
| 65 | case OSMO_RAT_GERAN_A: |
| 66 | return ran_peers_down_paging(net->a.sri, CELL_IDENT_LAC, vsub, pr->cause); |
| 67 | case OSMO_RAT_UTRAN_IU: |
| 68 | return ran_peers_down_paging(net->iu.sri, CELL_IDENT_LAC, vsub, pr->cause); |
| 69 | case OSMO_RAT_EUTRAN_SGS: |
| 70 | return sgs_iface_tx_paging(vsub, sgs_serv_ind_from_paging_cause(pr->cause)); |
| 71 | default: |
| 72 | break; |
| 73 | } |
| 74 | |
| 75 | LOG_PAGING(vsub, pr, LOGL_ERROR, " Cannot page, subscriber not attached\n"); |
| 76 | return -EINVAL; |
| 77 | } |
| 78 | |
| 79 | struct paging_request *paging_request_start(struct vlr_subscr *vsub, enum paging_cause cause, |
| 80 | paging_cb_t paging_cb, struct gsm_trans *trans, |
| 81 | const char *label) |
| 82 | { |
| 83 | int rc; |
| 84 | struct paging_request *pr; |
| 85 | struct gsm_network *net = vsub->vlr->user_ctx; |
| 86 | |
| 87 | pr = talloc_zero(vsub, struct paging_request); |
| 88 | OSMO_ASSERT(pr); |
| 89 | *pr = (struct paging_request){ |
| 90 | .label = label, |
| 91 | .cause = cause, |
| 92 | .paging_cb = paging_cb, |
| 93 | .trans = trans, |
| 94 | }; |
| 95 | |
| 96 | if (vsub->cs.is_paging) { |
| 97 | LOG_PAGING(vsub, pr, LOGL_DEBUG, "Already paging, not starting another request\n"); |
| 98 | } else { |
| 99 | LOG_PAGING(vsub, pr, LOGL_DEBUG, "Starting paging\n"); |
| 100 | |
| 101 | rc = msc_paging_request(pr, vsub); |
| 102 | if (rc <= 0) { |
| 103 | LOG_PAGING(vsub, pr, LOGL_ERROR, "Starting paging failed (rc=%d)\n", rc); |
| 104 | talloc_free(pr); |
| 105 | return NULL; |
| 106 | } |
| 107 | |
| 108 | /* reduced on the first paging callback */ |
| 109 | vlr_subscr_get(vsub, VSUB_USE_PAGING); |
| 110 | vsub->cs.is_paging = true; |
| 111 | osmo_timer_setup(&vsub->cs.paging_response_timer, paging_response_timer_cb, vsub); |
| 112 | osmo_timer_schedule(&vsub->cs.paging_response_timer, net->paging_response_timer, 0); |
| 113 | } |
| 114 | |
| 115 | llist_add_tail(&pr->entry, &vsub->cs.requests); |
| 116 | |
| 117 | return pr; |
| 118 | } |
| 119 | |
| 120 | void paging_request_remove(struct paging_request *pr) |
| 121 | { |
| 122 | struct gsm_trans *trans = pr->trans; |
| 123 | struct vlr_subscr *vsub = trans ? trans->vsub : NULL; |
| 124 | LOG_PAGING(vsub, pr, LOGL_DEBUG, "Removing Paging Request\n"); |
| 125 | |
| 126 | if (pr->trans && pr->trans->paging_request == pr) |
| 127 | pr->trans->paging_request = NULL; |
| 128 | |
| 129 | llist_del(&pr->entry); |
| 130 | talloc_free(pr); |
| 131 | } |
| 132 | |
| 133 | static void paging_concludes(struct vlr_subscr *vsub, struct msc_a *msc_a) |
| 134 | { |
| 135 | struct paging_request *pr, *pr_next; |
| 136 | struct paging_signal_data sig_data; |
| 137 | |
| 138 | osmo_timer_del(&vsub->cs.paging_response_timer); |
| 139 | |
| 140 | llist_for_each_entry_safe(pr, pr_next, &vsub->cs.requests, entry) { |
| 141 | struct gsm_trans *trans = pr->trans; |
| 142 | paging_cb_t paging_cb = pr->paging_cb; |
| 143 | |
| 144 | LOG_PAGING(vsub, pr, LOGL_DEBUG, "Paging Response action (%s)%s\n", |
| 145 | msc_a ? "success" : "expired", |
| 146 | paging_cb ? "" : " (no action defined)"); |
| 147 | |
| 148 | /* Remove the paging request before the paging_cb could deallocate e.g. the trans */ |
| 149 | paging_request_remove(pr); |
| 150 | pr = NULL; |
| 151 | |
| 152 | if (paging_cb) |
| 153 | paging_cb(msc_a, trans); |
| 154 | } |
| 155 | |
| 156 | /* Inform parts of the system we don't know */ |
| 157 | sig_data = (struct paging_signal_data){ |
| 158 | .vsub = vsub, |
| 159 | .msc_a = msc_a, |
| 160 | }; |
| 161 | osmo_signal_dispatch(SS_PAGING, msc_a ? S_PAGING_SUCCEEDED : S_PAGING_EXPIRED, &sig_data); |
| 162 | |
| 163 | /* balanced with the moment we start paging */ |
| 164 | if (vsub->cs.is_paging) { |
| 165 | vsub->cs.is_paging = false; |
| 166 | vlr_subscr_put(vsub, VSUB_USE_PAGING); |
| 167 | } |
| 168 | |
| 169 | /* Handling of the paging requests has usually added transactions, which keep the msc_a connection active. If |
| 170 | * there are none, then this probably marks release of the connection. */ |
| 171 | if (msc_a) |
| 172 | msc_a_put(msc_a, MSC_A_USE_PAGING_RESPONSE); |
| 173 | } |
| 174 | |
| 175 | void paging_response(struct msc_a *msc_a) |
| 176 | { |
| 177 | paging_concludes(msc_a_vsub(msc_a), msc_a); |
| 178 | } |
| 179 | |
| 180 | void paging_expired(struct vlr_subscr *vsub) |
| 181 | { |
| 182 | paging_concludes(vsub, NULL); |
| 183 | } |