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authorNeels Hofmeyr <neels@hofmeyr.de>2018-05-14 18:14:15 +0200
committerNeels Hofmeyr <neels@hofmeyr.de>2018-07-28 12:18:23 +0200
commit31f525e7560ad13e32cfc5e0b5f1862c0efcb991 (patch)
tree305b224d3e555eb69798d09e0edb269c32699418 /src/osmo-bsc/handover_fsm.c
parent596c402835bab2a01fba7d7233512009eb4142f5 (diff)
large refactoring: use FSMs for lchans; add inter-BSC HO
Add FSMs: - timeslot_fsm: handle dynamic timeslots and OML+RSL availability. - lchan_fsm: handle an individual lchan activation, RTP stream and release, signal the appropriate calling FSMs on success, failure, release. - mgw_endpoint_fsm: handle one entire endpoint with several CI. - assignment_fsm: BSSMAP Assignment Request. - handover_fsm: all of intra, inter-MO and inter-MT handover. Above FSMs absorb large parts of the gscon FSM. The gscon FSM was surpassing the maximum amount events (32), and it is more logical to treat assignment, handover and MGW procedures in separate FSMs. - Add logging macros for each FSM type: - LOG_TS() - LOG_LCHAN() - LOG_MGWEP(), LOG_CI() - LOG_ASSIGNMENT() - LOG_HO() These log with the osmo_fsm_inst where present. New style decision: logging without a final newline char is awkward, especially for gsmtap logging and when other logs interleave LOGPC() calls; we have various cases where the final \n goes missing, and also this invokes the log category checking N times instead of once. So I decided to make these macros *always* append a newline, but only if there is no final newline yet. I hope that the compiler optimizes the strlen() of the constant format strings away. Thus I can log with or without typing "\n" and always get an \n termination anyway. General: - replace osmo_timers, state enums and program-wide osmo_signal_dispatch() with dedicated FSM timeouts, states and events. - introduce a common way to handle Tnnn timers: gsm_timers.h/.c: struct T_def. These can be used (with some macro magic) to define a state's timeout once, and not make mistakes for each osmo_fsm_inst_state_chg(). Details: bsc_subscr_conn_fsm.c: - move most states of this FSM to lchan_fsm, assignment_fsm, handover_fsm and mgw_endpoint_fsm. - There is exactly one state for an ongoing Assignment, with all details handled in conn->assignment.fi. The state relies on the assignment_fsm's timeout. - There is one state for an ongoing Handover; except for an incoming Handover from a remote BSS, the gscon remains in ST_INIT until the new lchan and conn are both established. - move bssmap_add_lcls_status() to osmo_bsc_lcls.c abis_rsl.c: - move all dynamic timeslot logic away into timeslot_fsm. Only keep plain send/receive functions in abis_rsl.c - reduce some rsl functions to merely send a message, rename to "_tx_". - rsl_ipacc_mdcx(): add '_tx_' in the name; move parts that change the lchan state out into the lchan_fsm, the lchan->abis_ip.* are now set there prior to invoking this function. - move all timers and error/release handling away into various FSMs. - tweak ipa_smod_s_for_lchan() and ipa_rtp_pt_for_lchan() to not require an lchan passed, but just mode,type that they require. Rename to ipacc_speech_mode*() and ipacc_payload_type(). - add rsl_forward_layer3_info, used for inter-BSC HO MO, to just send the RR message received during BSSMAP Handover Command. - move various logging to LOG_LCHAN() in order to log with the lchan FSM instance. One drawback is that the lchan FSM is limited to one logging category, i.e. this moves some logging from DRR to DRSL. It might actually make sense to combine those categories. - lose LOGP...LOGPC logging cascades: they are bad for gsmtap logging and for performance. - handle_classmark_chg(): change logging, move cm2 len check out of the cm3 condition (I hope that's correct). - gsm48_send_ho_cmd(): split off gsm48_make_ho_cmd() which doesn't send right away, so that during inter-bsc HO we can make an RR Handover Command to send via the MSC to the remote BSS. assignment_fsm.c: - the Chan Mode Modify in case of re-using the same lchan is not implemented yet, because this was also missing in the previous implementation (OS#3357). osmo_bsc_api.c: - simplify bsc_mr_config() and move to lchan_fsm.c, the only caller; rename to lchan_mr_config(). (bsc_mr_config() used to copy the values to mr_bts_lv twice, once by member assignment and then again with a memcpy.) - During handover, we used to copy the MR config from the old lchan. Since we may handover between FR and HR, rather set the MR Config anew every time, so that FR rates are always available on FR lchans, and never on HR lchans. Depends: I03ee7ce840ecfa0b6a33358e7385528aabd4873f (libosmocore), I1f2918418c38918c5ac70acaa51a47adfca12b5e (libosmocore) Change-Id: I82e3f918295daa83274a4cf803f046979f284366
Diffstat (limited to 'src/osmo-bsc/handover_fsm.c')
-rw-r--r--src/osmo-bsc/handover_fsm.c1187
1 files changed, 1187 insertions, 0 deletions
diff --git a/src/osmo-bsc/handover_fsm.c b/src/osmo-bsc/handover_fsm.c
new file mode 100644
index 000000000..0430a7f6d
--- /dev/null
+++ b/src/osmo-bsc/handover_fsm.c
@@ -0,0 +1,1187 @@
+/* Handover FSM implementation for intra-BSC and inter-BSC Handover.
+ *
+ * (C) 2018 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de>
+ * All Rights Reserved
+ *
+ * Author: Neels Hofmeyr <neels@hofmeyr.de>
+ *
+ * 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/core/socket.h>
+
+#include <osmocom/gsm/rsl.h>
+#include <osmocom/gsm/gsm0808.h>
+
+#include <osmocom/bsc/debug.h>
+#include <osmocom/bsc/bsc_subscriber.h>
+
+#include <osmocom/bsc/handover_fsm.h>
+#include <osmocom/bsc/bsc_subscr_conn_fsm.h>
+#include <osmocom/bsc/lchan_select.h>
+#include <osmocom/bsc/lchan_fsm.h>
+#include <osmocom/bsc/gsm_04_08_rr.h>
+#include <osmocom/bsc/abis_rsl.h>
+#include <osmocom/bsc/bsc_msc_data.h>
+#include <osmocom/bsc/osmo_bsc.h>
+#include <osmocom/bsc/osmo_bsc_lcls.h>
+#include <osmocom/bsc/mgw_endpoint_fsm.h>
+#include <osmocom/bsc/codec_pref.h>
+
+#define LOG_FMT_BTS "bts %u lac-ci %u-%u arfcn-bsic %d-%d"
+#define LOG_ARGS_BTS(bts) \
+ (bts) ? (bts)->nr : 0, \
+ (bts) ? (bts)->location_area_code : 0, \
+ (bts) ? (bts)->cell_identity : 0, \
+ (bts) ? (bts)->c0->arfcn : 0, \
+ (bts) ? (bts)->bsic : 0
+
+#define LOG_FMT_FROM_LCHAN "%u-%u-%u-%s-%u-%s"
+#define LOG_ARGS_FROM_LCHAN(lchan) \
+ lchan ? lchan->ts->trx->bts->nr : 0, \
+ lchan ? lchan->ts->trx->nr : 0, \
+ lchan ? lchan->ts->nr : 0, \
+ lchan ? gsm_lchant_name(lchan->type) : "?", \
+ lchan ? lchan->nr : 0, \
+ lchan ? gsm48_chan_mode_name(lchan->tch_mode) : "?"
+
+#define LOG_FMT_TO_LCHAN "%u-%u-%u-%s%s%s-%u"
+#define LOG_ARGS_TO_LCHAN(lchan) \
+ lchan ? lchan->ts->trx->bts->nr : 0, \
+ lchan ? lchan->ts->trx->nr : 0, \
+ lchan ? lchan->ts->nr : 0, \
+ lchan ? gsm_pchan_name(lchan->ts->pchan_on_init) : "?", \
+ (!lchan || lchan->ts->pchan_on_init == lchan->ts->pchan_is)? "" : ":", \
+ (!lchan || lchan->ts->pchan_on_init == lchan->ts->pchan_is)? "" \
+ : gsm_pchan_name(lchan->ts->pchan_is), \
+ lchan ? lchan->nr : 0
+
+#define LOG_FMT_HO_SCOPE "(subscr %s) %s"
+#define LOG_ARGS_HO_SCOPE(conn) \
+ bsc_subscr_name(conn->bsub), \
+ handover_scope_name(conn->ho.scope)
+
+/* Assume presence of local var 'conn' as struct gsm_subscriber_connection.
+ * This is a macro to preserve the source file and line number in logging. */
+#define ho_count(counter) do { \
+ LOG_HO(conn, LOGL_DEBUG, "incrementing rate counter: %s %s\n", \
+ bsc_ctr_description[counter].name, \
+ bsc_ctr_description[counter].description); \
+ rate_ctr_inc(&conn->network->bsc_ctrs->ctr[counter]); \
+ } while(0)
+
+static uint8_t g_next_ho_ref = 1;
+
+const char *handover_status(struct gsm_subscriber_connection *conn)
+{
+ static char buf[256];
+ struct handover *ho = &conn->ho;
+
+ if (!conn)
+ return "";
+
+ if (ho->scope & (HO_INTRA_CELL | HO_INTRA_BSC)) {
+ if (ho->new_lchan)
+ snprintf(buf, sizeof(buf),
+ "("LOG_FMT_FROM_LCHAN") --HO-> (" LOG_FMT_TO_LCHAN ") " LOG_FMT_HO_SCOPE,
+ LOG_ARGS_FROM_LCHAN(conn->lchan),
+ LOG_ARGS_TO_LCHAN(ho->new_lchan),
+ LOG_ARGS_HO_SCOPE(conn));
+ else if (ho->new_bts)
+ snprintf(buf, sizeof(buf),
+ "("LOG_FMT_FROM_LCHAN") --HO-> ("LOG_FMT_BTS",%s) " LOG_FMT_HO_SCOPE,
+ LOG_ARGS_FROM_LCHAN(conn->lchan),
+ LOG_ARGS_BTS(ho->new_bts),
+ gsm_lchant_name(ho->new_lchan_type),
+ LOG_ARGS_HO_SCOPE(conn));
+ else
+ snprintf(buf, sizeof(buf),
+ "("LOG_FMT_FROM_LCHAN") --HO->(?) " LOG_FMT_HO_SCOPE,
+ LOG_ARGS_FROM_LCHAN(conn->lchan),
+ LOG_ARGS_HO_SCOPE(conn));
+
+ } else if (ho->scope & HO_INTER_BSC_OUT)
+ snprintf(buf, sizeof(buf),
+ "("LOG_FMT_FROM_LCHAN") --HO-> (%s) " LOG_FMT_HO_SCOPE,
+ LOG_ARGS_FROM_LCHAN(conn->lchan),
+ neighbor_ident_key_name(&ho->target_cell),
+ LOG_ARGS_HO_SCOPE(conn));
+
+ else if (ho->scope & HO_INTER_BSC_IN) {
+ if (ho->new_lchan)
+ snprintf(buf, sizeof(buf),
+ "(remote:%s) --HO-> (local:%s|"LOG_FMT_TO_LCHAN") " LOG_FMT_HO_SCOPE,
+ ho->inter_bsc_in.cell_id_serving_name,
+ ho->inter_bsc_in.cell_id_target_name,
+ LOG_ARGS_TO_LCHAN(ho->new_lchan),
+ LOG_ARGS_HO_SCOPE(conn));
+ else if (ho->new_bts)
+ snprintf(buf, sizeof(buf),
+ "(remote:%s) --HO-> (local:%s|"LOG_FMT_BTS",%s) " LOG_FMT_HO_SCOPE,
+ ho->inter_bsc_in.cell_id_serving_name,
+ ho->inter_bsc_in.cell_id_target_name,
+ LOG_ARGS_BTS(ho->new_bts),
+ gsm_lchant_name(ho->new_lchan_type),
+ LOG_ARGS_HO_SCOPE(conn));
+ else
+ snprintf(buf, sizeof(buf),
+ "(remote:%s) --HO-> (local:%s,%s) " LOG_FMT_HO_SCOPE,
+ ho->inter_bsc_in.cell_id_serving_name,
+ ho->inter_bsc_in.cell_id_target_name,
+ gsm_lchant_name(ho->new_lchan_type),
+ LOG_ARGS_HO_SCOPE(conn));
+ } else
+ snprintf(buf, sizeof(buf), LOG_FMT_HO_SCOPE, LOG_ARGS_HO_SCOPE(conn));
+ return buf;
+}
+
+static struct osmo_fsm ho_fsm;
+
+struct gsm_subscriber_connection *ho_fi_conn(struct osmo_fsm_inst *fi)
+{
+ OSMO_ASSERT(fi);
+ OSMO_ASSERT(fi->fsm == &ho_fsm);
+ OSMO_ASSERT(fi->priv);
+ return fi->priv;
+}
+
+static const struct state_timeout ho_fsm_timeouts[32] = {
+ [HO_ST_WAIT_LCHAN_ACTIVE] = { .T = 23042 },
+ [HO_ST_WAIT_RR_HO_DETECT] = { .T = 23042 },
+ [HO_ST_WAIT_RR_HO_COMPLETE] = { .T = 23042 },
+ [HO_ST_WAIT_LCHAN_ESTABLISHED] = { .T = 23042 },
+ [HO_ST_WAIT_MGW_ENDPOINT_TO_MSC] = { .T = 23042 },
+ [HO_OUT_ST_WAIT_HO_COMMAND] = { .T = 7 },
+ [HO_OUT_ST_WAIT_CLEAR] = { .T = 8 },
+};
+
+/* Transition to a state, using the T timer defined in ho_fsm_timeouts.
+ * The actual timeout value is in turn obtained from network->T_defs.
+ * Assumes local variable fi exists. */
+#define ho_fsm_state_chg(state) \
+ fsm_inst_state_chg_T(fi, state, \
+ ho_fsm_timeouts, \
+ ((struct gsm_subscriber_connection*)(fi->priv))->network->T_defs, \
+ 5)
+
+/* Log failure and transition to HO_ST_FAILURE, which triggers the appropriate actions. */
+#define ho_fail(result, fmt, args...) do { \
+ LOG_HO(conn, LOGL_ERROR, "Handover failed in state %s, %s: " fmt "\n", \
+ osmo_fsm_inst_state_name(conn->fi), handover_result_name(result), ## args); \
+ handover_end(conn, result); \
+ } while(0)
+
+#define ho_success() do { \
+ LOG_HO(conn, LOGL_DEBUG, "Handover succeeded\n"); \
+ handover_end(conn, HO_RESULT_OK); \
+ } while(0)
+
+/* issue handover to a cell identified by ARFCN and BSIC */
+void handover_request(struct handover_out_req *req)
+{
+ struct gsm_subscriber_connection *conn;
+ OSMO_ASSERT(req->old_lchan);
+
+ conn = req->old_lchan->conn;
+ OSMO_ASSERT(conn && conn->fi);
+
+ /* To make sure we're allowed to start a handover, go through a gscon event dispatch. */
+ osmo_fsm_inst_dispatch(conn->fi, GSCON_EV_HANDOVER_START, req);
+}
+
+/* Check that ho has old_lchan and/or new_lchan and conn pointers match.
+ * If old_lchan and/or new_lchan are NULL, omit those checks.
+ * On error, return false, log an error and call handover_end() with HO_RESULT_ERROR. */
+bool handover_is_sane(struct gsm_subscriber_connection *conn, struct gsm_lchan *old_lchan, struct gsm_lchan *new_lchan)
+{
+ if (!conn->ho.fi) {
+ LOG_HO(conn, LOGL_ERROR, "No handover ongoing\n");
+ return false;
+ }
+
+ if (old_lchan
+ && (conn != old_lchan->conn || conn->lchan != old_lchan))
+ goto insane;
+ if (new_lchan
+ && (conn != new_lchan->conn || conn->ho.new_lchan != new_lchan))
+ goto insane;
+ if (conn->lchan && conn->lchan == conn->ho.new_lchan)
+ goto insane;
+
+ return true;
+insane:
+ LOG_HO(conn, LOGL_ERROR, "Handover state is corrupted\n");
+ handover_end(conn, HO_RESULT_ERROR);
+ return false;
+}
+
+static void ho_fsm_update_id(struct osmo_fsm_inst *fi, const char *label)
+{
+ struct gsm_subscriber_connection *conn = ho_fi_conn(fi);
+ if (conn->fi->id)
+ osmo_fsm_inst_update_id_f(fi, "%s_%s", label, conn->fi->id);
+ else
+ osmo_fsm_inst_update_id_f(fi, "%s_conn%u", label, conn->sccp.conn_id);
+}
+
+static void handover_reset(struct gsm_subscriber_connection *conn)
+{
+ struct mgwep_ci *ci;
+ if (conn->ho.new_lchan)
+ /* New lchan was activated but never passed to a conn */
+ lchan_release(conn->ho.new_lchan, true, true, RSL_ERR_EQUIPMENT_FAIL);
+
+ ci = conn->ho.created_ci_for_msc;
+ if (ci) {
+ gscon_forget_mgw_endpoint_ci(conn, ci);
+ /* If this is the last endpoint released, the mgw_endpoint_fsm will terminate and tell
+ * the gscon about it. */
+ mgw_endpoint_ci_dlcx(ci);
+ }
+
+ conn->ho = (struct handover){
+ .fi = conn->ho.fi,
+ };
+}
+
+void handover_fsm_init()
+{
+ OSMO_ASSERT(osmo_fsm_register(&ho_fsm) == 0);
+}
+
+void handover_fsm_alloc(struct gsm_subscriber_connection *conn)
+{
+ OSMO_ASSERT(conn->fi);
+ OSMO_ASSERT(!conn->ho.fi);
+
+ conn->ho.fi = osmo_fsm_inst_alloc_child(&ho_fsm, conn->fi, GSCON_EV_HANDOVER_END);
+ OSMO_ASSERT(conn->ho.fi);
+ conn->ho.fi->priv = conn;
+}
+
+static void handover_start_intra_bsc(struct gsm_subscriber_connection *conn);
+static void handover_start_inter_bsc_out(struct gsm_subscriber_connection *conn,
+ const struct gsm0808_cell_id_list2 *target_cells);
+
+/* Invoked by gscon if a handover was accepted to start now. */
+void handover_start(struct handover_out_req *req)
+{
+
+ OSMO_ASSERT(req && req->old_lchan && req->old_lchan->conn);
+ struct gsm_subscriber_connection *conn = req->old_lchan->conn;
+ struct handover *ho = &conn->ho;
+ struct gsm_bts *bts;
+ const struct gsm0808_cell_id_list2 *cil;
+
+ if (conn->ho.fi) {
+ LOG_HO(conn, LOGL_ERROR, "Handover requested while another handover is ongoing; Ignore\n");
+ return;
+ }
+ handover_reset(conn);
+
+ handover_fsm_alloc(conn);
+
+ ho->from_hodec_id = req->from_hodec_id;
+ ho->new_lchan_type = req->new_lchan_type == GSM_LCHAN_NONE ?
+ req->old_lchan->type : req->new_lchan_type;
+ ho->target_cell = req->target_nik;
+
+ bts = bts_by_neighbor_ident(conn->network, &req->target_nik);
+ if (bts) {
+ ho->new_bts = bts;
+ handover_start_intra_bsc(conn);
+ return;
+ }
+
+ cil = neighbor_ident_get(conn->network->neighbor_bss_cells, &req->target_nik);
+ if (cil) {
+ handover_start_inter_bsc_out(conn, cil);
+ return;
+ }
+
+ LOG_HO(conn, LOGL_ERROR, "Cannot handover %s: neighbor unknown\n",
+ neighbor_ident_key_name(&req->target_nik));
+ handover_end(conn, HO_RESULT_FAIL_NO_CHANNEL);
+}
+
+/*! Hand over the specified logical channel to the specified new BTS and possibly change the lchan type.
+ * This is the main entry point for the actual handover algorithm, after the decision whether to initiate
+ * HO to a specific BTS. To not change the lchan type, pass old_lchan->type. */
+static void handover_start_intra_bsc(struct gsm_subscriber_connection *conn)
+{
+ struct handover *ho = &conn->ho;
+ struct osmo_fsm_inst *fi = conn->ho.fi;
+ struct lchan_activate_info info;
+
+ OSMO_ASSERT(ho->new_bts);
+ OSMO_ASSERT(ho->new_lchan_type != GSM_LCHAN_NONE);
+ OSMO_ASSERT(!ho->new_lchan);
+
+ ho->scope = (ho->new_bts == conn->lchan->ts->trx->bts) ? HO_INTRA_CELL : HO_INTRA_BSC;
+ ho->ho_ref = g_next_ho_ref++;
+ ho->async = true;
+
+ ho->new_lchan = lchan_select_by_type(ho->new_bts, ho->new_lchan_type);
+
+ if (ho->scope & HO_INTRA_CELL)
+ ho_fsm_update_id(fi, "intraCell");
+ else
+ ho_fsm_update_id(fi, "intraBSC");
+
+ ho_count(BSC_CTR_HANDOVER_ATTEMPTED);
+
+ if (!ho->new_lchan) {
+ ho_fail(HO_RESULT_FAIL_NO_CHANNEL,
+ "No %s lchan available on BTS %u",
+ gsm_lchant_name(ho->new_lchan_type), ho->new_bts->nr);
+ return;
+ }
+ LOG_HO(conn, LOGL_DEBUG, "Selected lchan %s\n", gsm_lchan_name(ho->new_lchan));
+
+ ho_fsm_state_chg(HO_ST_WAIT_LCHAN_ACTIVE);
+
+ info = (struct lchan_activate_info){
+ .activ_for = FOR_HANDOVER,
+ .for_conn = conn,
+ .chan_mode = conn->lchan->tch_mode,
+ .requires_voice_stream = conn->lchan->mgw_endpoint_ci_bts ? true : false,
+ .msc_assigned_cic = conn->ho.inter_bsc_in.msc_assigned_cic,
+ .old_lchan = conn->lchan,
+ };
+
+ lchan_activate(ho->new_lchan, &info);
+}
+
+/* 3GPP TS 48.008 ยง 3.2.1.8 Handover Request */
+static bool parse_ho_request(struct gsm_subscriber_connection *conn, const struct msgb *msg,
+ struct handover_in_req *req)
+{
+ struct tlv_parsed tp_arr[2];
+ struct tlv_parsed *tp = &tp_arr[0];
+ struct tlv_parsed *tp2 = &tp_arr[1];
+ struct tlv_p_entry *e;
+ int payload_length;
+ bool aoip = gscon_is_aoip(conn);
+ bool sccplite = gscon_is_sccplite(conn);
+
+ if ((aoip && sccplite) || !(aoip || sccplite)) {
+ LOG_HO(conn, LOGL_ERROR, "Received BSSMAP Handover Request, but conn is not"
+ " marked as exactly one of AoIP or SCCPlite\n");
+ return false;
+ }
+
+ payload_length = msg->tail - msg->l4h;
+ if (tlv_parse2(tp_arr, 2, gsm0808_att_tlvdef(), msg->l4h + 1, payload_length - 1, 0, 0) <= 0) {
+ LOG_HO(conn, LOGL_ERROR, "Failed to parse IEs\n");
+ return false;
+ }
+
+ if (!(e = TLVP_GET(tp, GSM0808_IE_CHANNEL_TYPE))) {
+ LOG_HO(conn, LOGL_ERROR, "Missing Channel Type IE\n");
+ return false;
+ }
+ if (gsm0808_dec_channel_type(&req->ct, e->val, e->len) <= 0) {
+ LOG_HO(conn, LOGL_ERROR, "Failed to parse Channel Type IE\n");
+ return false;
+ }
+
+ if (!(e = TLVP_GET(tp, GSM0808_IE_ENCRYPTION_INFORMATION))) {
+ LOG_HO(conn, LOGL_ERROR, "Missing Encryption Information IE\n");
+ return false;
+ }
+ if (gsm0808_dec_encrypt_info(&req->ei, e->val, e->len) <= 0) {
+ LOG_HO(conn, LOGL_ERROR, "Failed to parse Encryption Information IE\n");
+ return false;
+ }
+
+ if ((e = TLVP_GET(tp, GSM0808_IE_CLASSMARK_INFORMATION_TYPE_1))) {
+ if (e->len != sizeof(req->classmark.classmark1)) {
+ LOG_HO(conn, LOGL_ERROR, "Classmark Information 1 has wrong size\n");
+ return false;
+ }
+ req->classmark.classmark1 = *(struct gsm48_classmark1*)e->val;
+ req->classmark.classmark1_set = true;
+ } else if ((e = TLVP_GET(tp, GSM0808_IE_CLASSMARK_INFORMATION_T2))) {
+ uint8_t len = OSMO_MIN(sizeof(req->classmark.classmark2),
+ e->len);
+ if (!len) {
+ LOG_HO(conn, LOGL_ERROR, "Classmark Information 2 has zero size\n");
+ return false;
+ }
+ memcpy(&req->classmark.classmark2, e->val, len);
+ req->classmark.classmark2_len = len;
+ } else {
+ LOG_HO(conn, LOGL_ERROR, "Missing IE: either Classmark Information 1 or 2 required\n");
+ return false;
+ }
+
+ if (TLVP_PRESENT(tp, GSM0808_IE_AOIP_TRASP_ADDR)) {
+ int rc;
+ unsigned int u;
+ struct sockaddr_storage msc_rtp_sa;
+
+ if (!aoip) {
+ LOG_HO(conn, LOGL_ERROR,
+ "BSSMAP Handover Request contains AoIP Transport Address,"
+ " but this is not an AoIP connection\n");
+ return false;
+ }
+ rc = gsm0808_dec_aoip_trasp_addr(&msc_rtp_sa,
+ TLVP_VAL(tp, GSM0808_IE_AOIP_TRASP_ADDR),
+ TLVP_LEN(tp, GSM0808_IE_AOIP_TRASP_ADDR));
+ if (rc < 0) {
+ LOG_HO(conn, LOGL_ERROR, "Unable to decode AoIP Transport Address.\n");
+ return false;
+ }
+
+ u = osmo_sockaddr_to_str_and_uint(req->msc_assigned_rtp_addr,
+ sizeof(req->msc_assigned_rtp_addr),
+ &req->msc_assigned_rtp_port,
+ (const struct sockaddr*)&msc_rtp_sa);
+ if (!u || u >= sizeof(req->msc_assigned_rtp_addr)) {
+ LOG_HO(conn, LOGL_ERROR, "MSC's RTP address is too long\n");
+ return false;
+ }
+ } else if (aoip) {
+ LOG_HO(conn, LOGL_ERROR,
+ "BSSMAP Handover Request lacks AoIP Transport Address on an AoIP connection\n");
+ return false;
+ }
+
+ /* The Cell Identifier (Serving) and Cell Identifier (Target) are both 3.2.2.17 and are
+ * identified by the same tag. So get one from tp and the other from tp2. */
+ if (!(e = TLVP_GET(tp, GSM0808_IE_CELL_IDENTIFIER))) {
+ LOG_HO(conn, LOGL_ERROR, "Missing IE: Cell Identifier (Serving)\n");
+ return false;
+ }
+ if (gsm0808_dec_cell_id(&req->cell_id_serving, e->val, e->len) < 0) {
+ LOG_HO(conn, LOGL_ERROR, "Invalid IE: Cell Identifier (Serving)\n");
+ return false;
+ }
+ /* LOG_HO() also calls gsm0808_cell_id_name(), so to be able to use gsm0808_cell_id_name() in
+ * logging without getting mixed up with those static buffers, store the result. */
+ snprintf(req->cell_id_serving_name, sizeof(req->cell_id_serving_name),
+ gsm0808_cell_id_name(&req->cell_id_serving));
+
+ if (!(e = TLVP_GET(tp2, GSM0808_IE_CELL_IDENTIFIER))) {
+ LOG_HO(conn, LOGL_ERROR, "Missing IE: Cell Identifier (Target)\n");
+ return false;
+ }
+ if (gsm0808_dec_cell_id(&req->cell_id_target, e->val, e->len) < 0) {
+ LOG_HO(conn, LOGL_ERROR, "Invalid IE: Cell Identifier (Target)\n");
+ return false;
+ }
+ snprintf(req->cell_id_target_name, sizeof(req->cell_id_target_name),
+ gsm0808_cell_id_name(&req->cell_id_target));
+
+ if ((e = TLVP_GET(tp, GSM0808_IE_CIRCUIT_IDENTITY_CODE))) {
+ int timeslot;
+ int multiplex;
+
+ /* CIC is permitted in both AoIP and SCCPlite */
+ req->msc_assigned_cic = osmo_load16be(e->val);
+
+ /* For SCCPlite, the CIC implies the RTP port to use */
+ if (sccplite) {
+ timeslot = req->msc_assigned_cic & 0x1f;
+ multiplex = (req->msc_assigned_cic & ~0x1f) >> 5;
+ req->msc_assigned_rtp_port = mgcp_timeslot_to_port(multiplex, timeslot,
+ conn->sccp.msc->rtp_base);
+ LOG_HO(conn, LOGL_DEBUG, "Derived RTP port from MSC assigned CIC:"
+ " CIC=0x%x (timeslot=%d multiplex=%d) rtp_base=%d=0x%x RTP-port=%u\n",
+ req->msc_assigned_cic, timeslot, multiplex,
+ conn->sccp.msc->rtp_base, conn->sccp.msc->rtp_base,
+ req->msc_assigned_rtp_port);
+ }
+
+ } else if (sccplite) {
+ /* no CIC but SCCPlite: illegal */
+ LOG_HO(conn, LOGL_ERROR, "SCCPlite MSC, but no CIC in incoming inter-BSC Handover\n");
+ return false;
+ }
+
+ /* A lot of IEs remain ignored... */
+
+ return true;
+}
+
+static bool chan_mode_is_tch(enum gsm48_chan_mode mode)
+{
+ switch (mode) {
+ case GSM48_CMODE_SPEECH_V1:
+ case GSM48_CMODE_SPEECH_EFR:
+ case GSM48_CMODE_SPEECH_AMR:
+ return true;
+ default:
+ return false;
+ }
+}
+
+void handover_start_inter_bsc_in(struct gsm_subscriber_connection *conn,
+ struct msgb *ho_request_msg)
+{
+ struct lchan_activate_info info;
+ struct handover *ho = &conn->ho;
+ struct bsc_msc_data *msc = conn->sccp.msc;
+ struct handover_in_req *req = &ho->inter_bsc_in;
+ int match_idx;
+ enum gsm48_chan_mode mode;
+ bool full_rate;
+ struct osmo_fsm_inst *fi;
+
+ handover_fsm_alloc(conn);
+
+ *ho = (struct handover){
+ .fi = ho->fi,
+ .from_hodec_id = HODEC_REMOTE,
+ .scope = HO_INTER_BSC_IN,
+ .ho_ref = g_next_ho_ref++,
+ .async = true,
+ };
+
+ fi = ho->fi;
+ ho_fsm_update_id(fi, "interBSCin");
+
+ if (!parse_ho_request(conn, ho_request_msg, req)) {
+ ho_fail(HO_RESULT_ERROR, "Invalid Handover Request message from MSC\n");
+ return;
+ }
+
+ ho_count(BSC_CTR_INTER_BSC_HO_IN_ATTEMPTED);
+
+ /* Figure out which cell to handover to. */
+ for (match_idx = 0; ; match_idx++) {
+ struct gsm_bts *bts;
+ struct gsm_lchan *lchan;
+
+ bts = gsm_bts_by_cell_id(conn->network, &req->cell_id_target,
+ match_idx);
+
+ /* Did we iterate all matches? */
+ if (!bts)
+ break;
+
+ LOG_HO(conn, LOGL_DEBUG, "BTS %u matches cell id %s\n",
+ bts->nr, req->cell_id_target_name);
+
+ /* Figure out channel type */
+ if (match_codec_pref(&mode, &full_rate, &req->ct, &req->scl, msc->audio_support,
+ msc->audio_length, &bts->codec)) {
+ LOG_HO(conn, LOGL_DEBUG,
+ "BTS %u has no matching channel codec (%s, speech codec list len = %u)",
+ bts->nr, gsm0808_channel_type_name(&req->ct), req->scl.len);
+ continue;
+ }
+
+ LOG_HO(conn, LOGL_DEBUG, "BTS %u: Found matching audio type: %s %s (for %s)\n",
+ bts->nr, gsm48_chan_mode_name(mode), full_rate? "full-rate" : "half-rate",
+ gsm0808_channel_type_name(&req->ct));
+
+ lchan = lchan_select_by_chan_mode(bts, mode, full_rate);
+ if (!lchan) {
+ LOG_HO(conn, LOGL_DEBUG, "BTS %u has no matching free channels\n", bts->nr);
+ continue;
+ }
+
+ /* Found a match. */
+ ho->new_bts = bts;
+ ho->new_lchan = lchan;
+ break;
+ }
+
+ if (!ho->new_bts) {
+ ho_fail(HO_RESULT_ERROR, "No local cell matches the target %s",
+ req->cell_id_target_name);
+ return;
+ }
+
+ if (!ho->new_lchan) {
+ ho_fail(HO_RESULT_ERROR, "No free/matching lchan found for %s %s %s\n",
+ req->cell_id_target_name,
+ gsm48_chan_mode_name(mode), full_rate ? "full-rate" : "half-rate");
+ return;
+ }
+
+ /* Just for completeness' sake, maybe some logging uses it? */
+ ho->new_lchan_type = ho->new_lchan->type;
+
+ ho_fsm_state_chg(HO_ST_WAIT_LCHAN_ACTIVE);
+
+ info = (struct lchan_activate_info){
+ .activ_for = FOR_HANDOVER,
+ .for_conn = conn,
+ .chan_mode = mode,
+ .requires_voice_stream = chan_mode_is_tch(mode),
+ .msc_assigned_cic = req->msc_assigned_cic,
+ };
+
+ lchan_activate(ho->new_lchan, &info);
+}
+
+#define FUNC_RESULT_COUNTER(name) \
+static int result_counter_##name(enum handover_result result) \
+{ \
+ switch (result) { \
+ case HO_RESULT_OK: \
+ return BSC_CTR_##name##_COMPLETED; \
+ case HO_RESULT_FAIL_NO_CHANNEL: \
+ return BSC_CTR_##name##_NO_CHANNEL; \
+ case HO_RESULT_FAIL_RR_HO_FAIL: \
+ return BSC_CTR_##name##_FAILED; \
+ case HO_RESULT_FAIL_TIMEOUT: \
+ return BSC_CTR_##name##_TIMEOUT; \
+ case HO_RESULT_CONN_RELEASE: \
+ return BSC_CTR_##name##_STOPPED; \
+ default: \
+ case HO_RESULT_ERROR: \
+ return BSC_CTR_##name##_ERROR; \
+ } \
+}
+
+FUNC_RESULT_COUNTER(ASSIGNMENT)
+FUNC_RESULT_COUNTER(HANDOVER)
+FUNC_RESULT_COUNTER(INTER_BSC_HO_IN)
+
+static int result_counter_INTER_BSC_HO_OUT(enum handover_result result) {
+ switch (result) {
+ case HO_RESULT_OK:
+ return BSC_CTR_INTER_BSC_HO_IN_COMPLETED;
+ case HO_RESULT_FAIL_TIMEOUT:
+ return BSC_CTR_INTER_BSC_HO_IN_TIMEOUT;
+ case HO_RESULT_CONN_RELEASE:
+ return BSC_CTR_INTER_BSC_HO_IN_STOPPED;
+ default:
+ case HO_RESULT_ERROR:
+ return BSC_CTR_INTER_BSC_HO_IN_ERROR;
+ }
+}
+
+static int result_counter(enum handover_scope scope, enum handover_result result)
+{
+ switch (scope) {
+ case HO_INTRA_CELL:
+ return result_counter_ASSIGNMENT(result);
+ default:
+ LOGP(DHO, LOGL_ERROR, "invalid enum handover_scope value: %s\n",
+ handover_scope_name(scope));
+ /* use "normal" HO_INTRA_BSC counter... */
+ case HO_INTRA_BSC:
+ return result_counter_HANDOVER(result);
+ case HO_INTER_BSC_OUT:
+ return result_counter_INTER_BSC_HO_OUT(result);
+ case HO_INTER_BSC_IN:
+ return result_counter_INTER_BSC_HO_IN(result);
+ }
+}
+
+/* Notify the handover decision algorithm of failure and clear out any handover state. */
+void handover_end(struct gsm_subscriber_connection *conn, enum handover_result result)
+{
+ struct handover_decision_callbacks *hdc;
+ struct handover *ho = &conn->ho;
+
+ /* Sanity -- an error result ensures beyond doubt that we don't use the new lchan below
+ * when the handover isn't actually allowed to change this conn. */
+ if (result == HO_RESULT_OK && ho->new_lchan) {
+ if (!(ho->scope & (HO_INTRA_CELL | HO_INTRA_BSC | HO_INTER_BSC_IN))) {
+ LOG_HO(conn, LOGL_ERROR, "Got new lchan, but this is not an incoming inter-BSC HO\n");
+ result = HO_RESULT_ERROR;
+ }
+ if (ho->new_lchan->conn != conn) {
+ LOG_HO(conn, LOGL_ERROR, "Got new lchan, but it is for another conn\n");
+ result = HO_RESULT_ERROR;
+ }
+ }
+
+ if (ho->scope & HO_INTER_BSC_IN) {
+ if (result == HO_RESULT_OK) {
+ if (!ho->new_lchan) {
+ LOG_HO(conn, LOGL_ERROR, "Inter-BSC HO IN ends in success,"
+ " but there is no lchan\n");
+ result = HO_RESULT_ERROR;
+ } else
+ result = bsc_tx_bssmap_ho_complete(conn, ho->new_lchan);
+ } else {
+ bsc_tx_bssmap_ho_failure(conn);
+ /* TODO: Also send BSSMAP Clear Request? */
+ }
+ }
+
+ /* Rembered this only for error handling: should handover fail, handover_reset() will release the
+ * MGW endpoint right away. If successful, the conn continues to use the endpoint. */
+ if (result == HO_RESULT_OK)
+ conn->ho.created_ci_for_msc = NULL;
+
+ hdc = handover_decision_callbacks_get(ho->from_hodec_id);
+ if (hdc && hdc->on_handover_end)
+ hdc->on_handover_end(conn, result);
+
+ ho_count(result_counter(ho->scope, result));
+
+ LOG_HO(conn, LOGL_INFO, "Result: %s\n", handover_result_name(result));
+
+ if (ho->new_lchan && result == HO_RESULT_OK) {
+ gscon_change_primary_lchan(conn, conn->ho.new_lchan);
+ ho->new_lchan = NULL;
+ }
+
+ osmo_fsm_inst_dispatch(conn->fi, GSCON_EV_HANDOVER_END, &result);
+
+ /* Detach the new_lchan last, so we can still see it in above logging */
+ if (ho->new_lchan) {
+ /* Release new lchan, it didn't work out */
+ lchan_release(ho->new_lchan, false, true, RSL_ERR_EQUIPMENT_FAIL);
+ ho->new_lchan = NULL;
+ }
+
+ if ((ho->scope & HO_INTER_BSC_IN) && result == HO_RESULT_OK) {
+ conn->user_plane.msc_assigned_cic = conn->ho.inter_bsc_in.msc_assigned_cic;
+ osmo_strlcpy(conn->user_plane.msc_assigned_rtp_addr,
+ conn->ho.inter_bsc_in.msc_assigned_rtp_addr,
+ sizeof(conn->user_plane.msc_assigned_rtp_addr));
+ conn->user_plane.msc_assigned_rtp_port = conn->ho.inter_bsc_in.msc_assigned_rtp_port;
+ }
+
+ handover_reset(conn);
+
+ /* We've dispatched the handover result above, let's disconnect to not fire the same event again.
+ * The parent term event is a safety measure for unplanned termination. */
+ osmo_fsm_inst_unlink_parent(conn->ho.fi, conn);
+ osmo_fsm_inst_term(conn->ho.fi, OSMO_FSM_TERM_REGULAR, 0);
+}
+
+static void ho_fsm_wait_lchan_active(struct osmo_fsm_inst *fi, uint32_t event, void *data)
+{
+ struct gsm_subscriber_connection *conn = ho_fi_conn(fi);
+ switch (event) {
+
+ case HO_EV_LCHAN_ACTIVE:
+ ho_fsm_state_chg(HO_ST_WAIT_RR_HO_DETECT);
+ return;
+
+ case HO_EV_LCHAN_ERROR:
+ ho_fail(HO_RESULT_ERROR, "error while activating lchan %s",
+ gsm_lchan_name(conn->ho.new_lchan));
+ return;
+
+ default:
+ OSMO_ASSERT(false);
+ }
+}
+
+static void ho_fsm_wait_rr_ho_detect_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
+{
+ int rc;
+ struct gsm_subscriber_connection *conn = ho_fi_conn(fi);
+ struct handover *ho = &conn->ho;
+
+ struct msgb *rr_ho_cmd = gsm48_make_ho_cmd(ho->new_lchan,
+ ho->new_lchan->ms_power,
+ ho->ho_ref);
+ if (!rr_ho_cmd) {
+ ho_fail(HO_RESULT_ERROR, "Unable to compose RR Handover Command");
+ return;
+ }
+
+
+ if (ho->scope & (HO_INTRA_CELL | HO_INTRA_BSC)) {
+ /* conn->lchan is the old lchan being handovered from */
+ rr_ho_cmd->lchan = conn->lchan;
+ rc = gsm48_sendmsg(rr_ho_cmd);
+ if (rc)
+ ho_fail(HO_RESULT_ERROR, "Unable to Tx RR Handover Command (rc=%d %s)",
+ rc, strerror(-rc));
+ return;
+ }
+
+ if (ho->scope & HO_INTER_BSC_IN) {
+ rc = bsc_tx_bssmap_ho_request_ack(conn, rr_ho_cmd);
+ if (rc)
+ ho_fail(HO_RESULT_ERROR, "Unable to Tx BSSMAP Handover Request Ack (rc=%d %s)",
+ rc, strerror(-rc));
+ return;
+ }
+
+ ho_fail(HO_RESULT_ERROR, "Invalid situation, no target for RR Handover Command");
+}
+
+static void ho_fsm_wait_rr_ho_detect(struct osmo_fsm_inst *fi, uint32_t event, void *data)
+{
+ struct gsm_subscriber_connection *conn = ho_fi_conn(fi);
+ struct handover *ho = &conn->ho;
+ switch (event) {
+
+ case HO_EV_RR_HO_DETECT:
+ {
+ struct handover_rr_detect_data *d = data;
+ OSMO_ASSERT(d);
+ if (d->access_delay) {
+ LOG_HO(conn, LOGL_DEBUG, "RR Handover Detect (Access Delay=%u)\n",
+ *(d->access_delay));
+ } else
+ LOG_HO(conn, LOGL_DEBUG, "RR Handover Detect (no Access Delay IE)\n");
+ }
+
+ if (ho->scope & HO_INTER_BSC_IN) {
+ int rc = bsc_tx_bssmap_ho_detect(conn);
+ if (rc) {
+ ho_fail(HO_RESULT_ERROR,
+ "Unable to send BSSMAP Handover Detect");
+ return;
+ }
+ }
+
+ ho_fsm_state_chg(HO_ST_WAIT_RR_HO_COMPLETE);
+ /* The lchan FSM will already start to redirect the RTP stream */
+ return;
+
+ case HO_EV_RR_HO_COMPLETE:
+ LOG_HO(conn, LOGL_ERROR,
+ "Received RR Handover Complete, but haven't even seen a Handover Detect yet;"
+ " Accepting handover anyway\n");
+
+ ho_fsm_state_chg(HO_ST_WAIT_LCHAN_ESTABLISHED);
+ return;
+
+ case HO_EV_RR_HO_FAIL:
+ ho_fail(HO_RESULT_FAIL_RR_HO_FAIL, "Received RR Handover Fail message");
+ return;
+
+ default:
+ OSMO_ASSERT(false);
+ }
+}
+
+static void ho_fsm_wait_rr_ho_complete(struct osmo_fsm_inst *fi, uint32_t event, void *data)
+{
+ struct gsm_subscriber_connection *conn = ho_fi_conn(fi);
+
+ switch (event) {
+
+ case HO_EV_RR_HO_COMPLETE:
+ ho_fsm_state_chg(HO_ST_WAIT_LCHAN_ESTABLISHED);
+ return;
+
+ case HO_EV_RR_HO_FAIL:
+ ho_fail(HO_RESULT_FAIL_RR_HO_FAIL, "Received RR Handover Fail message");
+ return;
+
+ default:
+ OSMO_ASSERT(false);
+ }
+}
+
+static void ho_fsm_post_lchan_established(struct osmo_fsm_inst *fi);
+
+static void ho_fsm_wait_lchan_established_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
+{
+ struct gsm_subscriber_connection *conn = ho_fi_conn(fi);
+
+ if (conn->ho.fi && lchan_state_is(conn->ho.new_lchan, LCHAN_ST_ESTABLISHED))
+ ho_fsm_post_lchan_established(fi);
+}
+
+static void ho_fsm_wait_lchan_established(struct osmo_fsm_inst *fi, uint32_t event, void *data)
+{
+ switch (event) {
+
+ case HO_EV_LCHAN_ESTABLISHED:
+ ho_fsm_post_lchan_established(fi);
+ break;
+
+ default:
+ OSMO_ASSERT(false);
+ }
+}
+
+static void ho_fsm_post_lchan_established(struct osmo_fsm_inst *fi)
+{
+ struct gsm_subscriber_connection *conn = ho_fi_conn(fi);
+ struct handover *ho = &conn->ho;
+
+ if (ho->new_lchan->activate.requires_voice_stream
+ && (ho->scope & HO_INTER_BSC_IN))
+ ho_fsm_state_chg(HO_ST_WAIT_MGW_ENDPOINT_TO_MSC);
+ else
+ ho_success();
+}
+
+static void ho_fsm_wait_mgw_endpoint_to_msc_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
+{
+ struct gsm_subscriber_connection *conn = ho_fi_conn(fi);
+ struct handover *ho = &conn->ho;
+
+ if (!gscon_connect_mgw_to_msc(conn,
+ ho->new_lchan,
+ ho->inter_bsc_in.msc_assigned_rtp_addr,
+ ho->inter_bsc_in.msc_assigned_rtp_port,
+ fi,
+ HO_EV_MSC_MGW_OK,
+ HO_EV_MSC_MGW_FAIL,
+ NULL,
+ &ho->created_ci_for_msc)) {
+ ho_fail(HO_RESULT_ERROR,
+ "Unable to connect MGW endpoint to the MSC side");
+ }
+}
+
+static void ho_fsm_wait_mgw_endpoint_to_msc(struct osmo_fsm_inst *fi, uint32_t event, void *data)
+{
+ struct gsm_subscriber_connection *conn = ho_fi_conn(fi);
+ switch (event) {
+
+ case HO_EV_MSC_MGW_OK:
+ /* For AoIP, we created the MGW endpoint. Ensure it is really there, and log it. */
+ if (gscon_is_aoip(conn)) {
+ const struct mgcp_conn_peer *mgw_info;
+ mgw_info = mgwep_ci_get_rtp_info(conn->user_plane.mgw_endpoint_ci_msc);
+ if (!mgw_info) {
+ ho_fail(HO_RESULT_ERROR,
+ "Unable to retrieve RTP port info allocated by MGW for"
+ " the MSC side.");
+ return;
+ }
+ LOG_HO(conn, LOGL_DEBUG, "MGW's MSC side CI: %s:%u\n",
+ mgw_info->addr, mgw_info->port);
+ }
+ ho_success();
+ return;
+
+ case HO_EV_MSC_MGW_FAIL:
+ ho_fail(HO_RESULT_ERROR,
+ "Unable to connect MGW endpoint to the MSC side");
+ return;
+
+ default:
+ OSMO_ASSERT(false);
+ }
+}
+
+/* Inter-BSC OUT */
+
+static void handover_start_inter_bsc_out(struct gsm_subscriber_connection *conn,
+ const struct gsm0808_cell_id_list2 *target_cells)
+{
+ int rc;
+ struct handover *ho = &conn->ho;
+ struct osmo_fsm_inst *fi = conn->ho.fi;
+
+ ho->scope = HO_INTER_BSC_OUT;
+ ho_fsm_update_id(fi, "interBSCout");
+ ho_count(BSC_CTR_INTER_BSC_HO_OUT_ATTEMPTED);
+
+ rc = bsc_tx_bssmap_ho_required(conn->lchan, target_cells);
+ if (rc) {
+ ho_fail(HO_RESULT_ERROR, "Unable to send BSSMAP Handover Required message");
+ return;
+ }
+
+ ho_fsm_state_chg(HO_OUT_ST_WAIT_HO_COMMAND);
+}
+
+static void ho_out_fsm_wait_ho_command(struct osmo_fsm_inst *fi, uint32_t event, void *data)
+{
+ int rc;
+ struct ho_out_rx_bssmap_ho_command *rx;
+ struct gsm_subscriber_connection *conn = ho_fi_conn(fi);
+ switch (event) {
+
+ case HO_OUT_EV_BSSMAP_HO_COMMAND:
+ rx = data;
+ if (!rx) {
+ ho_fail(HO_RESULT_ERROR,
+ "Rx BSSMAP Handover Command: no L3 info passed with event");
+ return;
+ }
+
+ LOG_HO(conn, LOGL_DEBUG, "Rx BSSMAP Handover Command: forwarding Layer 3 Info: %s\n",
+ osmo_hexdump(rx->l3_info, rx->l3_info_len));
+
+ rc = rsl_forward_layer3_info(conn->lchan, rx->l3_info, rx->l3_info_len);
+ if (rc) {
+ ho_fail(HO_RESULT_ERROR,
+ "Rx BSSMAP Handover Command: Failed to forward Layer 3 Info (rc=%d %s)",
+ rc, strerror(-rc));
+ return;
+ }
+
+ ho_fsm_state_chg(HO_OUT_ST_WAIT_CLEAR);
+ return;
+
+ default:
+ OSMO_ASSERT(false);
+ }
+}
+
+
+#define S(x) (1 << (x))
+
+static const struct osmo_fsm_state ho_fsm_states[] = {
+ [HO_ST_NOT_STARTED] = {
+ .name = "NOT_STARTED",
+ .out_state_mask = 0
+ | S(HO_ST_WAIT_LCHAN_ACTIVE)
+ | S(HO_OUT_ST_WAIT_HO_COMMAND)
+ ,
+ },
+ [HO_ST_WAIT_LCHAN_ACTIVE] = {
+ .name = "WAIT_LCHAN_ACTIVE",
+ .action = ho_fsm_wait_lchan_active,
+ .in_event_mask = 0
+ | S(HO_EV_LCHAN_ACTIVE)
+ | S(HO_EV_LCHAN_ERROR)
+ ,
+ .out_state_mask = 0
+ | S(HO_ST_WAIT_LCHAN_ACTIVE)
+ | S(HO_ST_WAIT_RR_HO_DETECT)
+ ,
+ },
+ [HO_ST_WAIT_RR_HO_DETECT] = {
+ .name = "WAIT_RR_HO_DETECT",
+ .onenter = ho_fsm_wait_rr_ho_detect_onenter,
+ .action = ho_fsm_wait_rr_ho_detect,
+ .in_event_mask = 0
+ | S(HO_EV_RR_HO_DETECT)
+ | S(HO_EV_RR_HO_COMPLETE) /* actually as error */
+ | S(HO_EV_RR_HO_FAIL)
+ ,
+ .out_state_mask = 0
+ | S(HO_ST_WAIT_RR_HO_COMPLETE)
+ | S(HO_ST_WAIT_LCHAN_ESTABLISHED)
+ ,
+ },
+ [HO_ST_WAIT_RR_HO_COMPLETE] = {
+ .name = "WAIT_RR_HO_COMPLETE",
+ .action = ho_fsm_wait_rr_ho_complete,
+ .in_event_mask = 0
+ | S(HO_EV_RR_HO_COMPLETE)
+ | S(HO_EV_RR_HO_FAIL)
+ ,
+ .out_state_mask = 0
+ | S(HO_ST_WAIT_LCHAN_ESTABLISHED)
+ ,
+ },
+ [HO_ST_WAIT_LCHAN_ESTABLISHED] = {
+ .name = "WAIT_LCHAN_ESTABLISHED",
+ .onenter = ho_fsm_wait_lchan_established_onenter,
+ .action = ho_fsm_wait_lchan_established,
+ .in_event_mask = 0
+ | S(HO_EV_LCHAN_ESTABLISHED)
+ ,
+ .out_state_mask = 0
+ | S(HO_ST_WAIT_MGW_ENDPOINT_TO_MSC)
+ ,
+ },
+ [HO_ST_WAIT_MGW_ENDPOINT_TO_MSC] = {
+ .name = "WAIT_MGW_ENDPOINT_TO_MSC",
+ .onenter = ho_fsm_wait_mgw_endpoint_to_msc_onenter,
+ .action = ho_fsm_wait_mgw_endpoint_to_msc,
+ .in_event_mask = 0
+ | S(HO_EV_MSC_MGW_OK)
+ | S(HO_EV_MSC_MGW_FAIL)
+ ,
+ },
+
+ [HO_OUT_ST_WAIT_HO_COMMAND] = {
+ .name = "inter-BSC-OUT:WAIT_HO_COMMAND",
+ .action = ho_out_fsm_wait_ho_command,
+ .in_event_mask = 0
+ | S(HO_OUT_EV_BSSMAP_HO_COMMAND)
+ ,
+ .out_state_mask = 0
+ | S(HO_OUT_ST_WAIT_CLEAR)
+ ,
+ },
+ [HO_OUT_ST_WAIT_CLEAR] = {
+ .name = "inter-BSC-OUT:WAIT_CLEAR",
+ },
+};
+
+static const struct value_string ho_fsm_event_names[] = {
+ OSMO_VALUE_STRING(HO_EV_LCHAN_ACTIVE),
+ OSMO_VALUE_STRING(HO_EV_LCHAN_ESTABLISHED),
+ OSMO_VALUE_STRING(HO_EV_LCHAN_ERROR),
+ OSMO_VALUE_STRING(HO_EV_RR_HO_DETECT),
+ OSMO_VALUE_STRING(HO_EV_RR_HO_COMPLETE),
+ OSMO_VALUE_STRING(HO_EV_RR_HO_FAIL),
+ OSMO_VALUE_STRING(HO_EV_MSC_MGW_OK),
+ OSMO_VALUE_STRING(HO_EV_MSC_MGW_FAIL),
+ OSMO_VALUE_STRING(HO_EV_CONN_RELEASING),
+ OSMO_VALUE_STRING(HO_OUT_EV_BSSMAP_HO_COMMAND),
+ {}
+};
+
+void ho_fsm_allstate_action(struct osmo_fsm_inst *fi, uint32_t event, void *data)
+{
+ struct gsm_subscriber_connection *conn = ho_fi_conn(fi);
+ switch (event) {
+
+ case HO_EV_CONN_RELEASING:
+ switch (fi->state) {
+ case HO_OUT_ST_WAIT_CLEAR:
+ ho_success();
+ return;
+ default:
+ ho_fail(HO_RESULT_CONN_RELEASE,
+ "Connection releasing in the middle of handover");
+ return;
+ }
+
+ case HO_EV_LCHAN_ERROR:
+ switch (fi->state) {
+ case HO_OUT_ST_WAIT_HO_COMMAND:
+ case HO_OUT_ST_WAIT_CLEAR:
+ LOG_HO(conn, LOGL_ERROR, "Event not permitted: %s\n",
+ osmo_fsm_event_name(fi->fsm, event));
+ return;
+
+ default:
+ ho_fail(HO_RESULT_ERROR, "Error while establishing lchan %s",
+ gsm_lchan_name(data));
+ return;
+ }
+
+ default:
+ OSMO_ASSERT(false);
+ }
+}
+
+int ho_fsm_timer_cb(struct osmo_fsm_inst *fi)
+{
+ struct gsm_subscriber_connection *conn = ho_fi_conn(fi);
+ ho_fail(HO_RESULT_FAIL_TIMEOUT, "Timeout");
+ return 0;
+}
+
+void ho_fsm_cleanup(struct osmo_fsm_inst *fi, enum osmo_fsm_term_cause cause)
+{
+ struct gsm_subscriber_connection *conn = ho_fi_conn(fi);
+ conn->ho.fi = NULL;
+}
+
+static struct osmo_fsm ho_fsm = {
+ .name = "handover",
+ .states = ho_fsm_states,
+ .num_states = ARRAY_SIZE(ho_fsm_states),
+ .log_subsys = DRSL,
+ .event_names = ho_fsm_event_names,
+ .allstate_action = ho_fsm_allstate_action,
+ .allstate_event_mask = 0
+ | S(HO_EV_CONN_RELEASING)
+ | S(HO_EV_LCHAN_ERROR)
+ ,
+ .timer_cb = ho_fsm_timer_cb,
+ .cleanup = ho_fsm_cleanup,
+};