199 lines
5.4 KiB
C
199 lines
5.4 KiB
C
/* SMLC Lb connection implementation */
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/*
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* (C) 2020 by sysmocom s.m.f.c. <info@sysmocom.de>
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* All Rights Reserved
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*
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* Author: Neels Hofmeyr
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU Affero General Public License as published by
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* the Free Software Foundation; either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Affero General Public License for more details.
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*
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* You should have received a copy of the GNU Affero General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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*/
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#include <errno.h>
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#include <osmocom/core/logging.h>
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#include <osmocom/core/fsm.h>
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#include <osmocom/core/signal.h>
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#include <osmocom/gsm/bssmap_le.h>
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#include <osmocom/smlc/debug.h>
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#include <osmocom/smlc/smlc_data.h>
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#include <osmocom/smlc/sccp_lb_inst.h>
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#include <osmocom/smlc/lb_peer.h>
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#include <osmocom/smlc/lb_conn.h>
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#include <osmocom/smlc/smlc_loc_req.h>
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static int lb_conn_use_cb(struct osmo_use_count_entry *e, int32_t old_use_count, const char *file, int line)
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{
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struct lb_conn *lb_conn = e->use_count->talloc_object;
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int32_t total;
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int level;
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if (!e->use)
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return -EINVAL;
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total = osmo_use_count_total(&lb_conn->use_count);
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if (total == 0
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|| (total == 1 && old_use_count == 0 && e->count == 1))
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level = LOGL_INFO;
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else
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level = LOGL_DEBUG;
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LOG_LB_CONN_SL(lb_conn, DREF, level, file, line, "%s %s: now used by %s\n",
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(e->count - old_use_count) > 0? "+" : "-", e->use,
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osmo_use_count_to_str_c(OTC_SELECT, &lb_conn->use_count));
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if (e->count < 0)
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return -ERANGE;
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if (total == 0)
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lb_conn_close(lb_conn);
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return 0;
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}
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static struct lb_conn *lb_conn_alloc(struct lb_peer *lb_peer, uint32_t sccp_conn_id, const char *use_token)
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{
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struct lb_conn *lb_conn;
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lb_conn = talloc(lb_peer, struct lb_conn);
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OSMO_ASSERT(lb_conn);
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*lb_conn = (struct lb_conn){
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.lb_peer = lb_peer,
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.sccp_conn_id = sccp_conn_id,
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.use_count = {
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.talloc_object = lb_conn,
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.use_cb = lb_conn_use_cb,
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},
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};
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llist_add(&lb_conn->entry, &lb_peer->sli->lb_conns);
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lb_conn_get(lb_conn, use_token);
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return lb_conn;
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}
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struct lb_conn *lb_conn_create_incoming(struct lb_peer *lb_peer, uint32_t sccp_conn_id, const char *use_token)
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{
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LOG_LB_PEER(lb_peer, LOGL_DEBUG, "Incoming lb_conn id: %u\n", sccp_conn_id);
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return lb_conn_alloc(lb_peer, sccp_conn_id, use_token);
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}
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struct lb_conn *lb_conn_create_outgoing(struct lb_peer *lb_peer, const char *use_token)
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{
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int new_conn_id = sccp_lb_inst_next_conn_id();
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if (new_conn_id < 0)
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return NULL;
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LOG_LB_PEER(lb_peer, LOGL_DEBUG, "Outgoing lb_conn id: %u\n", new_conn_id);
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return lb_conn_alloc(lb_peer, new_conn_id, use_token);
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}
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struct lb_conn *lb_conn_find_by_smlc_subscr(struct smlc_subscr *smlc_subscr, const char *use_token)
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{
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struct lb_conn *lb_conn;
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llist_for_each_entry(lb_conn, &g_smlc->lb->lb_conns, entry) {
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if (lb_conn->smlc_subscr == smlc_subscr) {
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lb_conn_get(lb_conn, use_token);
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return lb_conn;
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}
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}
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return NULL;
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}
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int lb_conn_down_l2_co(struct lb_conn *lb_conn, struct msgb *l3, bool initial)
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{
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struct lb_peer_ev_ctx co = {
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.conn_id = lb_conn->sccp_conn_id,
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.lb_conn = lb_conn,
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.msg = l3,
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};
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if (!lb_conn->lb_peer)
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return -EIO;
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return osmo_fsm_inst_dispatch(lb_conn->lb_peer->fi,
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initial ? LB_PEER_EV_MSG_DOWN_CO_INITIAL : LB_PEER_EV_MSG_DOWN_CO,
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&co);
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}
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int lb_conn_rx(struct lb_conn *lb_conn, struct msgb *msg, bool initial)
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{
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struct bssap_le_pdu bssap_le;
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struct osmo_bssap_le_err *err;
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if (osmo_bssap_le_dec(&bssap_le, &err, msg, msg)) {
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LOG_LB_CONN(lb_conn, LOGL_ERROR, "Rx BSSAP-LE with error: %s\n", err->logmsg);
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return -EINVAL;
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}
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return smlc_loc_req_rx_bssap_le(lb_conn, &bssap_le);
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}
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int lb_conn_send_bssmap_le(struct lb_conn *lb_conn, const struct bssmap_le_pdu *bssmap_le)
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{
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struct msgb *msg;
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int rc;
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struct bssap_le_pdu bssap_le = {
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.discr = BSSAP_LE_MSG_DISCR_BSSMAP_LE,
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.bssmap_le = *bssmap_le,
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};
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msg = osmo_bssap_le_enc(&bssap_le);
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if (!msg) {
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LOG_LB_CONN(lb_conn, LOGL_ERROR, "Unable to encode %s\n",
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osmo_bssap_le_pdu_to_str_c(OTC_SELECT, &bssap_le));
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return -EINVAL;
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}
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rc = lb_conn_down_l2_co(lb_conn, msg, false);
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msgb_free(msg);
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if (rc)
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LOG_LB_CONN(lb_conn, LOGL_ERROR, "Unable to send %s\n",
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osmo_bssap_le_pdu_to_str_c(OTC_SELECT, &bssap_le));
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return rc;
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}
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/* Regularly close the lb_conn */
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void lb_conn_close(struct lb_conn *lb_conn)
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{
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if (!lb_conn)
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return;
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if (lb_conn->closing)
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return;
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lb_conn->closing = true;
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LOG_LB_PEER(lb_conn->lb_peer, LOGL_DEBUG, "Closing lb_conn\n");
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if (lb_conn->lb_peer) {
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/* Todo: pass a useful SCCP cause? */
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sccp_lb_disconnect(lb_conn->lb_peer->sli, lb_conn->sccp_conn_id, 0);
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lb_conn->lb_peer = NULL;
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}
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if (lb_conn->smlc_loc_req)
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osmo_fsm_inst_term(lb_conn->smlc_loc_req->fi, OSMO_FSM_TERM_REGULAR, NULL);
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if (lb_conn->smlc_subscr)
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smlc_subscr_put(lb_conn->smlc_subscr, SMLC_SUBSCR_USE_LB_CONN);
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llist_del(&lb_conn->entry);
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talloc_free(lb_conn);
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}
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/* Same as lb_conn_close() but without sending any SCCP messages (e.g. after RESET) */
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void lb_conn_discard(struct lb_conn *lb_conn)
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{
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if (!lb_conn)
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return;
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/* Make sure to drop dead and don't dispatch things like DISCONNECT requests on SCCP. */
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lb_conn->lb_peer = NULL;
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lb_conn_close(lb_conn);
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}
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