Osmocom Packet control Unit (PCU): Network-side GPRS (RLC/MAC); BTS- or BSC-colocated https://osmocom.org/projects/osmopcu
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osmo-pcu/src/nacc_fsm.c

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29 KiB

/* nacc_fsm.c
*
* Copyright (C) 2021 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de>
* Author: Pau Espin Pedrol <pespin@sysmocom.de>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include <unistd.h>
#include <talloc.h>
#include <osmocom/core/rate_ctr.h>
#include <osmocom/ctrl/control_cmd.h>
#include <osmocom/ctrl/control_if.h>
#include <osmocom/gsm/gsm48.h>
#include <osmocom/gprs/gprs_bssgp.h>
#include <osmocom/gprs/gprs_bssgp_rim.h>
#include <nacc_fsm.h>
#include <gprs_rlcmac.h>
#include <gprs_debug.h>
#include <gprs_ms.h>
#include <encoding.h>
#include <bts.h>
#include <neigh_cache.h>
#define X(s) (1 << (s))
/* Infer CTRL id (seqnum) for a given tgt arfcn+bsic (bsic range: 0-63) */
#define arfcn_bsic_2_ctrl_id(arfcn, bsic) ((arfcn) * 100 + (bsic))
static const struct osmo_tdef_state_timeout nacc_fsm_timeouts[32] = {
[NACC_ST_INITIAL] = {},
[NACC_ST_WAIT_RESOLVE_RAC_CI] = { .T = PCU_TDEF_NEIGH_RESOLVE_TO },
[NACC_ST_WAIT_REQUEST_SI] = { .T = PCU_TDEF_SI_RESOLVE_TO },
[NACC_ST_TX_NEIGHBOUR_DATA] = {},
[NACC_ST_TX_CELL_CHG_CONTINUE] = {},
[NACC_ST_WAIT_CELL_CHG_CONTINUE_ACK] = {}, /* Timeout through event controlled by tbf::poll_timeout() */
[NACC_ST_DONE] = {},
};
/* Transition to a state, using the T timer defined in nacc_fsm_timeouts.
* The actual timeout value is in turn obtained from conn->T_defs.
* Assumes local variable fi exists. */
#define nacc_fsm_state_chg(fi, NEXT_STATE) \
osmo_tdef_fsm_inst_state_chg(fi, NEXT_STATE, \
nacc_fsm_timeouts, \
((struct nacc_fsm_ctx*)(fi->priv))->ms->bts->pcu->T_defs, \
-1)
const struct value_string nacc_fsm_event_names[] = {
{ NACC_EV_RX_CELL_CHG_NOTIFICATION, "RX_CELL_CHG_NOTIFICATION" },
{ NACC_EV_RX_RAC_CI, "RX_RAC_CI" },
{ NACC_EV_RX_SI, "RX_SI" },
{ NACC_EV_CREATE_RLCMAC_MSG, "CREATE_RLCMAC_MSG" },
{ NACC_EV_RX_CELL_CHG_CONTINUE_ACK, "RX_CELL_CHG_CONTINUE_ACK"},
{ NACC_EV_TIMEOUT_CELL_CHG_CONTINUE, "TIMEOUT_CELL_CHG_CONTINUE" },
{ 0, NULL }
};
/* TS 44 060 11.2.9e Packet Neighbour Cell Data */
static struct msgb *create_packet_neighbour_cell_data(struct nacc_fsm_ctx *ctx,
const struct gprs_rlcmac_tbf *tbf,
bool *all_si_info_sent)
{
struct msgb *msg;
int rc;
RlcMacDownlink_t *mac_control_block;
struct GprsMs *ms = tbf_ms(tbf);
OSMO_ASSERT(tbf_is_tfi_assigned(tbf));
uint8_t tfi_is_dl = tbf_direction(tbf) == GPRS_RLCMAC_DL_TBF;
uint8_t tfi = tbf_tfi(tbf);
uint8_t container_id = 0;
PNCDContainer_t container;
size_t max_len, len_to_write;
uint8_t *cont_buf;
uint8_t si_type = ctx->si_info.type_psi ? 0x01 : 0x0;
memset(&container, 0, sizeof(container));
if (ctx->container_idx == 0) {
container.UnionType = 1; /* with ID */
container.u.PNCD_Container_With_ID.ARFCN = ctx->neigh_key.tgt_arfcn;
container.u.PNCD_Container_With_ID.BSIC = ctx->neigh_key.tgt_bsic;
cont_buf = &container.u.PNCD_Container_With_ID.CONTAINER[0];
max_len = sizeof(container.u.PNCD_Container_With_ID.CONTAINER) - 1;
} else {
container.UnionType = 0; /* without ID */
cont_buf = &container.u.PNCD_Container_Without_ID.CONTAINER[0];
max_len = sizeof(container.u.PNCD_Container_Without_ID.CONTAINER) - 1;
}
len_to_write = ctx->si_info.si_len - ctx->si_info_bytes_sent;
if (len_to_write == 0) {
/* We sent all info on last message filing it exactly, we now send a zeroed one to finish */
*all_si_info_sent = true;
*cont_buf = (si_type << 5) | 0x00;
} else if (len_to_write >= max_len) {
/* We fill the rlcmac block, we'll need more messages */
*all_si_info_sent = false;
*cont_buf = (si_type << 5) | 0x1F;
memcpy(cont_buf + 1, &ctx->si_info.si_buf[ctx->si_info_bytes_sent], max_len);
ctx->si_info_bytes_sent += max_len;
} else {
/* Last block, we don't fill it exactly */
*all_si_info_sent = true;
*cont_buf = (si_type << 5) | (len_to_write & 0x1F);
memcpy(cont_buf + 1, &ctx->si_info.si_buf[ctx->si_info_bytes_sent], len_to_write);
ctx->si_info_bytes_sent += len_to_write;
}
msg = msgb_alloc(GSM_MACBLOCK_LEN, "neighbour_cell_data");
if (!msg)
return NULL;
/* Initialize a bit vector that uses allocated msgb as the data buffer. */
struct bitvec bv = {
.data = msgb_put(msg, GSM_MACBLOCK_LEN),
.data_len = GSM_MACBLOCK_LEN,
};
bitvec_unhex(&bv, DUMMY_VEC);
mac_control_block = (RlcMacDownlink_t *)talloc_zero(ctx->ms, RlcMacDownlink_t);
write_packet_neighbour_cell_data(mac_control_block,
tfi_is_dl, tfi, container_id,
ctx->container_idx, &container);
LOGP(DNACC, LOGL_DEBUG, "+++++++++++++++++++++++++ TX : Packet Neighbour Cell Data +++++++++++++++++++++++++\n");
rc = encode_gsm_rlcmac_downlink(&bv, mac_control_block);
if (rc < 0) {
LOGP(DTBF, LOGL_ERROR, "Encoding of Packet Neighbour Cell Data failed (%d)\n", rc);
goto free_ret;
}
LOGP(DNACC, LOGL_DEBUG, "------------------------- TX : Packet Neighbour Cell Data -------------------------\n");
rate_ctr_inc(rate_ctr_group_get_ctr(bts_rate_counters(ms->bts), CTR_PKT_NEIGH_CELL_DATA));
talloc_free(mac_control_block);
ctx->container_idx++;
return msg;
free_ret:
talloc_free(mac_control_block);
msgb_free(msg);
return NULL;
}
/* TS 44 060 11.2.2a Packet Cell Change Continue */
static struct msgb *create_packet_cell_chg_continue(const struct nacc_fsm_ctx *ctx,
const struct nacc_ev_create_rlcmac_msg_ctx *data,
uint32_t *new_poll_fn)
{
struct msgb *msg;
int rc;
RlcMacDownlink_t *mac_control_block;
struct gprs_rlcmac_tbf *tbf = data->tbf;
struct GprsMs *ms = tbf_ms(tbf);
unsigned int rrbp;
rc = tbf_check_polling(tbf, data->fn, data->ts, new_poll_fn, &rrbp);
if (rc < 0) {
LOGP(DTBF, LOGL_ERROR, "Failed registering poll for Pkt Cell Chg Continue (%d)\n", rc);
return NULL;
}
msg = msgb_alloc(GSM_MACBLOCK_LEN, "pkt_cell_chg_continue");
if (!msg)
return NULL;
/* Initialize a bit vector that uses allocated msgb as the data buffer. */
struct bitvec bv = {
.data = msgb_put(msg, GSM_MACBLOCK_LEN),
.data_len = GSM_MACBLOCK_LEN,
};
bitvec_unhex(&bv, DUMMY_VEC);
mac_control_block = (RlcMacDownlink_t *)talloc_zero(ctx->ms, RlcMacDownlink_t);
OSMO_ASSERT(tbf_is_tfi_assigned(tbf));
uint8_t tfi_is_dl = tbf_direction(tbf) == GPRS_RLCMAC_DL_TBF;
uint8_t tfi = tbf_tfi(tbf);
uint8_t container_id = 0;
write_packet_cell_change_continue(mac_control_block, 1, rrbp, tfi_is_dl, tfi, true,
ctx->neigh_key.tgt_arfcn, ctx->neigh_key.tgt_bsic, container_id);
LOGP(DNACC, LOGL_DEBUG, "+++++++++++++++++++++++++ TX : Packet Cell Change Continue +++++++++++++++++++++++++\n");
rc = encode_gsm_rlcmac_downlink(&bv, mac_control_block);
if (rc < 0) {
LOGP(DTBF, LOGL_ERROR, "Encoding of Packet Cell Change Continue failed (%d)\n", rc);
goto free_ret;
}
LOGP(DNACC, LOGL_DEBUG, "------------------------- TX : Packet Cell Change Continue -------------------------\n");
rate_ctr_inc(rate_ctr_group_get_ctr(bts_rate_counters(ms->bts), CTR_PKT_CELL_CHG_CONTINUE));
talloc_free(mac_control_block);
tbf_set_polling(tbf, *new_poll_fn, data->ts, PDCH_ULC_POLL_CELL_CHG_CONTINUE);
LOGPTBFDL(tbf, LOGL_DEBUG, "Scheduled 'Packet Cell Change Continue' polling on PACCH (FN=%d, TS=%d)\n",
*new_poll_fn, data->ts);
return msg;
free_ret:
talloc_free(mac_control_block);
msgb_free(msg);
return NULL;
}
static int fill_rim_ran_info_req(const struct nacc_fsm_ctx *ctx, struct bssgp_ran_information_pdu *pdu)
{
struct gprs_rlcmac_bts *bts = ctx->ms->bts;
*pdu = (struct bssgp_ran_information_pdu){
.routing_info_dest = {
.discr = BSSGP_RIM_ROUTING_INFO_GERAN,
.geran = {
.raid = {
.mcc = ctx->cgi_ps.rai.lac.plmn.mcc,
.mnc = ctx->cgi_ps.rai.lac.plmn.mnc,
.mnc_3_digits = ctx->cgi_ps.rai.lac.plmn.mnc_3_digits,
.lac = ctx->cgi_ps.rai.lac.lac,
.rac = ctx->cgi_ps.rai.rac,
},
.cid = ctx->cgi_ps.cell_identity,
},
},
.routing_info_src = {
.discr = BSSGP_RIM_ROUTING_INFO_GERAN,
.geran = {
.raid = {
.mcc = bts->cgi_ps.rai.lac.plmn.mcc,
.mnc = bts->cgi_ps.rai.lac.plmn.mnc,
.mnc_3_digits = bts->cgi_ps.rai.lac.plmn.mnc_3_digits,
.lac = bts->cgi_ps.rai.lac.lac,
.rac = bts->cgi_ps.rai.rac,
},
.cid = bts->cgi_ps.cell_identity,
},
},
.rim_cont_iei = BSSGP_IE_RI_REQ_RIM_CONTAINER,
.decoded_present = true,
.decoded = {
.req_rim_cont = {
.app_id = BSSGP_RAN_INF_APP_ID_NACC,
.seq_num = 1,
.pdu_ind = {
.ack_requested = 0,
.pdu_type_ext = RIM_PDU_TYPE_SING_REP,
},
.prot_ver = 1,
.son_trans_app_id = NULL,
.son_trans_app_id_len = 0,
.u = {
.app_cont_nacc = {
.reprt_cell = ctx->cgi_ps,
},
},
},
},
};
return 0;
}
static int fill_neigh_key_from_bts_pkt_cell_chg_not(struct neigh_cache_entry_key *neigh_key,
const struct gprs_rlcmac_bts *bts,
const Packet_Cell_Change_Notification_t *notif)
{
switch (notif->Target_Cell.UnionType) {
case 0: /* GSM */
neigh_key->local_lac = bts->cgi_ps.rai.lac.lac;
neigh_key->local_ci = bts->cgi_ps.cell_identity;
neigh_key->tgt_arfcn = notif->Target_Cell.u.Target_Cell_GSM_Notif.ARFCN;
neigh_key->tgt_bsic = notif->Target_Cell.u.Target_Cell_GSM_Notif.BSIC;
return 0;
default:
return -ENOTSUP;
}
}
#define SI_HDR_LEN 2
static void bts_fill_si_cache_value(const struct gprs_rlcmac_bts *bts, struct si_cache_value *val)
{
val->type_psi = false;
val->si_len = 0;
if (bts->si1_is_set) {
osmo_static_assert(sizeof(bts->si1) - SI_HDR_LEN == BSSGP_RIM_SI_LEN, _si1_header_size);
memcpy(&val->si_buf[val->si_len], bts->si1 + SI_HDR_LEN, BSSGP_RIM_SI_LEN);
val->si_len += BSSGP_RIM_SI_LEN;
}
if (bts->si3_is_set) {
osmo_static_assert(sizeof(bts->si3) - SI_HDR_LEN == BSSGP_RIM_SI_LEN, _si3_header_size);
memcpy(&val->si_buf[val->si_len], bts->si3 + SI_HDR_LEN, BSSGP_RIM_SI_LEN);
val->si_len += BSSGP_RIM_SI_LEN;
}
if (bts->si13_is_set) {
osmo_static_assert(sizeof(bts->si13) - SI_HDR_LEN == BSSGP_RIM_SI_LEN, _si13_header_size);
memcpy(&val->si_buf[val->si_len], bts->si13 + SI_HDR_LEN, BSSGP_RIM_SI_LEN);
val->si_len += BSSGP_RIM_SI_LEN;
}
}
/* Called on event NACC_EV_RX_CELL_CHG_NOTIFICATION on states after
* WAIT_RESOLVE_RAC_CI. Ignore duplicate messages, transition back if target
* cell changed.
*/
static void handle_retrans_pkt_cell_chg_notif(struct nacc_fsm_ctx *ctx, const Packet_Cell_Change_Notification_t *notif)
{
struct gprs_rlcmac_bts *bts = ctx->ms->bts;
struct neigh_cache_entry_key neigh_key;
if (fill_neigh_key_from_bts_pkt_cell_chg_not(&neigh_key, bts, notif) < 0) {
LOGPFSML(ctx->fi, LOGL_NOTICE, "TargetCell type=0x%x not supported\n",
notif->Target_Cell.UnionType);
if (ctx->fi->state != NACC_ST_TX_CELL_CHG_CONTINUE)
nacc_fsm_state_chg(ctx->fi, NACC_ST_TX_CELL_CHG_CONTINUE);
return;
}
/* If tgt cell changed, restart resolving it */
if (!neigh_cache_entry_key_eq(&ctx->neigh_key, &neigh_key)) {
ctx->neigh_key = neigh_key;
nacc_fsm_state_chg(ctx->fi, NACC_ST_WAIT_RESOLVE_RAC_CI);
}
/* else: ignore it, it's a dup, carry on what we were doing */
}
////////////////
// FSM states //
////////////////
static void st_initial(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct nacc_fsm_ctx *ctx = (struct nacc_fsm_ctx *)fi->priv;
struct gprs_rlcmac_bts *bts = ctx->ms->bts;
Packet_Cell_Change_Notification_t *notif;
switch (event) {
case NACC_EV_RX_CELL_CHG_NOTIFICATION:
notif = (Packet_Cell_Change_Notification_t *)data;
if (fill_neigh_key_from_bts_pkt_cell_chg_not(&ctx->neigh_key, bts, notif) < 0) {
LOGPFSML(fi, LOGL_NOTICE, "TargetCell type=0x%x not supported\n",
notif->Target_Cell.UnionType);
osmo_fsm_inst_term(fi, OSMO_FSM_TERM_ERROR, NULL);
} else {
nacc_fsm_state_chg(fi, NACC_ST_WAIT_RESOLVE_RAC_CI);
}
break;
default:
OSMO_ASSERT(0);
}
}
static int send_neigh_addr_req_ctrl_iface(struct nacc_fsm_ctx *ctx)
{
struct gprs_rlcmac_bts *bts = ctx->ms->bts;
struct gprs_pcu *pcu = bts->pcu;
struct ctrl_cmd *cmd = NULL;
int rc;
/* We may have changed to this state previously (eg: we are handling
* another Pkt cell Change Notify with different target). Avoid
* re-creating the socket in that case. */
if (ctx->neigh_ctrl_conn->write_queue.bfd.fd == -1) {
rc = osmo_sock_init2_ofd(&ctx->neigh_ctrl_conn->write_queue.bfd,
AF_UNSPEC, SOCK_STREAM, IPPROTO_TCP,
NULL, 0, pcu->vty.neigh_ctrl_addr, pcu->vty.neigh_ctrl_port,
OSMO_SOCK_F_CONNECT);
if (rc < 0) {
LOGPFSML(ctx->fi, LOGL_ERROR,
"Failed to establish CTRL (neighbor resolution) connection to BSC r=%s:%u\n\n",
pcu->vty.neigh_ctrl_addr, pcu->vty.neigh_ctrl_port);
goto err_term;
}
}
cmd = ctrl_cmd_create(ctx, CTRL_TYPE_GET);
if (!cmd) {
LOGPFSML(ctx->fi, LOGL_ERROR, "CTRL msg creation failed\n");
goto err_term;
}
cmd->id = talloc_asprintf(cmd, "%u", arfcn_bsic_2_ctrl_id(ctx->neigh_key.tgt_arfcn,
ctx->neigh_key.tgt_bsic));
cmd->variable = talloc_asprintf(cmd, "neighbor_resolve_cgi_ps_from_lac_ci.%d.%d.%d.%d",
ctx->neigh_key.local_lac, ctx->neigh_key.local_ci,
ctx->neigh_key.tgt_arfcn, ctx->neigh_key.tgt_bsic);
rc = ctrl_cmd_send(&ctx->neigh_ctrl_conn->write_queue, cmd);
if (rc) {
LOGPFSML(ctx->fi, LOGL_ERROR, "CTRL msg sent failed: %d\n", rc);
goto err_term;
}
talloc_free(cmd);
return 0;
err_term:
talloc_free(cmd);
return -1;
}
static int send_neigh_addr_req(struct nacc_fsm_ctx *ctx)
{
struct gprs_rlcmac_bts *bts = ctx->ms->bts;
/* If PCU was configured to use the old CTRL interface, use it: */
if (ctx->neigh_ctrl_conn)
return send_neigh_addr_req_ctrl_iface(ctx);
/* Otherwise, by default the new PCUIF over IPA Abis multiplex proto should be used: */
return pcu_tx_neigh_addr_res_req(bts, &ctx->neigh_key);
}
static void st_wait_resolve_rac_ci_on_enter(struct osmo_fsm_inst *fi, uint32_t prev_state)
{
struct nacc_fsm_ctx *ctx = (struct nacc_fsm_ctx *)fi->priv;
struct gprs_rlcmac_bts *bts = ctx->ms->bts;
struct gprs_pcu *pcu = bts->pcu;
const struct osmo_cell_global_id_ps *cgi_ps;
/* First try to find the value in the cache */
cgi_ps = neigh_cache_lookup_value(pcu->neigh_cache, &ctx->neigh_key);
if (cgi_ps) {
ctx->cgi_ps = *cgi_ps;
nacc_fsm_state_chg(fi, NACC_ST_WAIT_REQUEST_SI);
return;
}
/* CGI-PS not in cache, resolve it using BSC Neighbor Resolution CTRL interface */
LOGPFSML(fi, LOGL_DEBUG, "No CGI-PS found in cache, resolving " NEIGH_CACHE_ENTRY_KEY_FMT "...\n",
NEIGH_CACHE_ENTRY_KEY_ARGS(&ctx->neigh_key));
if (send_neigh_addr_req(ctx) < 0)
nacc_fsm_state_chg(fi, NACC_ST_TX_CELL_CHG_CONTINUE);
}
static void st_wait_resolve_rac_ci(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct nacc_fsm_ctx *ctx = (struct nacc_fsm_ctx *)fi->priv;
const Packet_Cell_Change_Notification_t *notif;
switch (event) {
case NACC_EV_RX_CELL_CHG_NOTIFICATION:
notif = (const Packet_Cell_Change_Notification_t *)data;
handle_retrans_pkt_cell_chg_notif(ctx, notif);
break;
case NACC_EV_RX_RAC_CI:
/* data is NULL upon failure */
if (data) {
ctx->cgi_ps = *(struct osmo_cell_global_id_ps *)data;
nacc_fsm_state_chg(fi, NACC_ST_WAIT_REQUEST_SI);
} else {
nacc_fsm_state_chg(fi, NACC_ST_TX_CELL_CHG_CONTINUE);
}
break;
default:
OSMO_ASSERT(0);
}
}
/* At this point, we expect correct tgt cell info to be already in ctx->cgi_ps */
static void st_wait_request_si_on_enter(struct osmo_fsm_inst *fi, uint32_t prev_state)
{
struct nacc_fsm_ctx *ctx = (struct nacc_fsm_ctx *)fi->priv;
struct gprs_rlcmac_bts *bts = ctx->ms->bts;
struct gprs_pcu *pcu = bts->pcu;
struct bssgp_ran_information_pdu pdu;
const struct si_cache_value *si;
struct gprs_rlcmac_bts *bts_i;
int rc;
/* First check if the CGI-PS addresses a cell managed by this PCU. If
* that's the case, we already have the info and there's no need to go
* the RIM way since we'd end up to this same PCU on the other end anyway.
*/
llist_for_each_entry(bts_i, &the_pcu->bts_list, list) {
if (bts_i == bts) /* Makes no sense targeting the same cell */
continue;
if (osmo_cgi_ps_cmp(&ctx->cgi_ps, &bts_i->cgi_ps) != 0)
continue;
LOGPFSML(fi, LOGL_DEBUG, "neighbor CGI-PS %s addresses local BTS %d\n",
osmo_cgi_ps_name(&ctx->cgi_ps), bts_i->nr);
bts_fill_si_cache_value(bts, &ctx->si_info);
/* Tell the PCU scheduler we are ready to go, from here one we
* are polled/driven by the scheduler */
nacc_fsm_state_chg(fi, NACC_ST_TX_NEIGHBOUR_DATA);
return;
}
/* First check if we have SI info for the target cell in cache */
si = si_cache_lookup_value(pcu->si_cache, &ctx->cgi_ps);
if (si) {
/* Copy info since cache can be deleted at any point */
memcpy(&ctx->si_info, si, sizeof(ctx->si_info));
/* Tell the PCU scheduler we are ready to go, from here one we
* are polled/driven by the scheduler */
nacc_fsm_state_chg(fi, NACC_ST_TX_NEIGHBOUR_DATA);
return;
}
/* SI info not in cache, resolve it using RIM procedure against SGSN */
if (fill_rim_ran_info_req(ctx, &pdu) < 0) {
nacc_fsm_state_chg(fi, NACC_ST_TX_CELL_CHG_CONTINUE);
return;
}
LOGPFSML(fi, LOGL_INFO, "Tx RIM RAN-INFO to request SI of %s\n",
osmo_cgi_ps_name(&ctx->cgi_ps));
rc = bssgp_tx_rim(&pdu, gprs_ns2_nse_nsei(ctx->ms->bts->nse));
if (rc < 0) {
LOGPFSML(fi, LOGL_ERROR, "Failed transmitting RIM RAN-INFO %s PDU: %d\n",
osmo_cgi_ps_name(&ctx->cgi_ps), rc);
nacc_fsm_state_chg(fi, NACC_ST_TX_CELL_CHG_CONTINUE);
return;
}
}
static void st_wait_request_si(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct nacc_fsm_ctx *ctx = (struct nacc_fsm_ctx *)fi->priv;
const Packet_Cell_Change_Notification_t *notif;
struct si_cache_entry *entry;
switch (event) {
case NACC_EV_RX_CELL_CHG_NOTIFICATION:
notif = (const Packet_Cell_Change_Notification_t *)data;
handle_retrans_pkt_cell_chg_notif(ctx, notif);
break;
case NACC_EV_RX_SI:
entry = (struct si_cache_entry *)data;
/* Copy info since cache can be deleted at any point */
memcpy(&ctx->si_info, &entry->value, sizeof(ctx->si_info));
/* Tell the PCU scheduler we are ready to go, from here one we
* are polled/driven by the scheduler */
nacc_fsm_state_chg(fi, NACC_ST_TX_NEIGHBOUR_DATA);
break;
default:
OSMO_ASSERT(0);
}
}
/* At this point, we already received all required SI information to send stored
* in struct nacc_fsm_ctx. We now wait for scheduler to ask us to construct
* RLCMAC DL CTRL messages to move FSM states forward
*/
static void st_tx_neighbour_data_on_enter(struct osmo_fsm_inst *fi, uint32_t prev_state)
{
struct nacc_fsm_ctx *ctx = (struct nacc_fsm_ctx *)fi->priv;
ctx->si_info_bytes_sent = 0;
ctx->container_idx = 0;
}
static void st_tx_neighbour_data(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct nacc_fsm_ctx *ctx = (struct nacc_fsm_ctx *)fi->priv;
const Packet_Cell_Change_Notification_t *notif;
struct nacc_ev_create_rlcmac_msg_ctx *data_ctx;
bool all_si_info_sent;
switch (event) {
case NACC_EV_RX_CELL_CHG_NOTIFICATION:
notif = (const Packet_Cell_Change_Notification_t *)data;
handle_retrans_pkt_cell_chg_notif(ctx, notif);
break;
case NACC_EV_CREATE_RLCMAC_MSG:
data_ctx = (struct nacc_ev_create_rlcmac_msg_ctx *)data;
data_ctx->msg = create_packet_neighbour_cell_data(ctx, data_ctx->tbf, &all_si_info_sent);
if (!data_ctx->msg) {
osmo_fsm_inst_term(fi, OSMO_FSM_TERM_ERROR, NULL);
return;
}
if (all_si_info_sent) /* DONE */
nacc_fsm_state_chg(fi, NACC_ST_TX_CELL_CHG_CONTINUE);
break;
default:
OSMO_ASSERT(0);
}
}
/* st_cell_chg_continue_on_enter:
* At this point, we already sent all Pkt Cell Neighbour Change rlcmac
* blocks, and we only need to wait to be scheduled again to send PKT
* CELL CHANGE NOTIFICATION and then we are done
*/
static void st_cell_chg_continue(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct nacc_fsm_ctx *ctx = (struct nacc_fsm_ctx *)fi->priv;
const Packet_Cell_Change_Notification_t *notif;
struct nacc_ev_create_rlcmac_msg_ctx *data_ctx;
switch (event) {
case NACC_EV_RX_CELL_CHG_NOTIFICATION:
notif = (const Packet_Cell_Change_Notification_t *)data;
handle_retrans_pkt_cell_chg_notif(ctx, notif);
break;
case NACC_EV_CREATE_RLCMAC_MSG:
data_ctx = (struct nacc_ev_create_rlcmac_msg_ctx *)data;
data_ctx->msg = create_packet_cell_chg_continue(ctx, data_ctx, &ctx->continue_poll_fn);
if (data_ctx->msg) {
ctx->continue_poll_ts = data_ctx->ts;
nacc_fsm_state_chg(fi, NACC_ST_WAIT_CELL_CHG_CONTINUE_ACK);
}
break;
default:
OSMO_ASSERT(0);
}
}
static void st_wait_cell_chg_continue_ack(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct nacc_fsm_ctx *ctx = (struct nacc_fsm_ctx *)fi->priv;
const Packet_Cell_Change_Notification_t *notif;
switch (event) {
case NACC_EV_RX_CELL_CHG_NOTIFICATION:
notif = (const Packet_Cell_Change_Notification_t *)data;
handle_retrans_pkt_cell_chg_notif(ctx, notif);
break;
case NACC_EV_TIMEOUT_CELL_CHG_CONTINUE:
nacc_fsm_state_chg(fi, NACC_ST_TX_CELL_CHG_CONTINUE);
break;
case NACC_EV_RX_CELL_CHG_CONTINUE_ACK:
nacc_fsm_state_chg(fi, NACC_ST_DONE);
break;
default:
OSMO_ASSERT(0);
}
}
static void st_done_on_enter(struct osmo_fsm_inst *fi, uint32_t prev_state)
{
osmo_fsm_inst_term(fi, OSMO_FSM_TERM_REGULAR, NULL);
}
static void nacc_fsm_cleanup(struct osmo_fsm_inst *fi, enum osmo_fsm_term_cause cause)
{
struct nacc_fsm_ctx *ctx = (struct nacc_fsm_ctx *)fi->priv;
/* after cleanup() finishes, FSM termination calls osmo_fsm_inst_free,
so we need to avoid double-freeing it during ctx talloc free
destructor */
talloc_reparent(ctx, ctx->ms, ctx->fi);
ctx->fi = NULL;
/* remove references from owning MS and free entire ctx */
ctx->ms->nacc = NULL;
talloc_free(ctx);
}
static int nacc_fsm_timer_cb(struct osmo_fsm_inst *fi)
{
switch (fi->T) {
case PCU_TDEF_NEIGH_RESOLVE_TO:
case PCU_TDEF_SI_RESOLVE_TO:
nacc_fsm_state_chg(fi, NACC_ST_TX_CELL_CHG_CONTINUE);
break;
}
return 0;
}
static struct osmo_fsm_state nacc_fsm_states[] = {
[NACC_ST_INITIAL] = {
.in_event_mask =
X(NACC_EV_RX_CELL_CHG_NOTIFICATION),
.out_state_mask =
X(NACC_ST_WAIT_RESOLVE_RAC_CI),
.name = "INITIAL",
.action = st_initial,
},
[NACC_ST_WAIT_RESOLVE_RAC_CI] = {
.in_event_mask =
X(NACC_EV_RX_CELL_CHG_NOTIFICATION) |
X(NACC_EV_RX_RAC_CI),
.out_state_mask =
X(NACC_ST_WAIT_RESOLVE_RAC_CI) |
X(NACC_ST_WAIT_REQUEST_SI) |
X(NACC_ST_TX_CELL_CHG_CONTINUE),
.name = "WAIT_RESOLVE_RAC_CI",
.onenter = st_wait_resolve_rac_ci_on_enter,
.action = st_wait_resolve_rac_ci,
},
[NACC_ST_WAIT_REQUEST_SI] = {
.in_event_mask =
X(NACC_EV_RX_CELL_CHG_NOTIFICATION) |
X(NACC_EV_RX_SI),
.out_state_mask =
X(NACC_ST_WAIT_RESOLVE_RAC_CI) |
X(NACC_ST_TX_NEIGHBOUR_DATA) |
X(NACC_ST_TX_CELL_CHG_CONTINUE),
.name = "WAIT_REQUEST_SI",
.onenter = st_wait_request_si_on_enter,
.action = st_wait_request_si,
},
[NACC_ST_TX_NEIGHBOUR_DATA] = {
.in_event_mask =
X(NACC_EV_RX_CELL_CHG_NOTIFICATION) |
X(NACC_EV_CREATE_RLCMAC_MSG),
.out_state_mask =
X(NACC_ST_WAIT_RESOLVE_RAC_CI) |
X(NACC_ST_TX_CELL_CHG_CONTINUE),
.name = "TX_NEIGHBOUR_DATA",
.onenter = st_tx_neighbour_data_on_enter,
.action = st_tx_neighbour_data,
},
[NACC_ST_TX_CELL_CHG_CONTINUE] = {
.in_event_mask =
X(NACC_EV_RX_CELL_CHG_NOTIFICATION) |
X(NACC_EV_CREATE_RLCMAC_MSG),
.out_state_mask =
X(NACC_ST_WAIT_RESOLVE_RAC_CI) |
X(NACC_ST_WAIT_CELL_CHG_CONTINUE_ACK),
.name = "TX_CELL_CHG_CONTINUE",
.action = st_cell_chg_continue,
},
[NACC_ST_WAIT_CELL_CHG_CONTINUE_ACK] = {
.in_event_mask =
X(NACC_EV_RX_CELL_CHG_NOTIFICATION) |
X(NACC_EV_RX_CELL_CHG_CONTINUE_ACK) |
X(NACC_EV_TIMEOUT_CELL_CHG_CONTINUE),
.out_state_mask =
X(NACC_ST_WAIT_RESOLVE_RAC_CI) |
X(NACC_ST_TX_CELL_CHG_CONTINUE) |
X(NACC_ST_DONE),
.name = "WAIT_CELL_CHG_CONTINUE_ACK",
.action = st_wait_cell_chg_continue_ack,
},
[NACC_ST_DONE] = {
.in_event_mask = 0,
.out_state_mask = 0,
.name = "DONE",
.onenter = st_done_on_enter,
},
};
static struct osmo_fsm nacc_fsm = {
.name = "NACC",
.states = nacc_fsm_states,
.num_states = ARRAY_SIZE(nacc_fsm_states),
.timer_cb = nacc_fsm_timer_cb,
.cleanup = nacc_fsm_cleanup,
.log_subsys = DNACC,
.event_names = nacc_fsm_event_names,
};
static __attribute__((constructor)) void nacc_fsm_init(void)
{
OSMO_ASSERT(osmo_fsm_register(&nacc_fsm) == 0);
}
void nacc_fsm_ctrl_reply_cb(struct ctrl_handle *ctrl, struct ctrl_cmd *cmd, void *data)
{
struct nacc_fsm_ctx *ctx = (struct nacc_fsm_ctx *)data;
char *tmp = NULL, *tok, *saveptr;
unsigned int exp_id;
struct osmo_cell_global_id_ps cgi_ps;
LOGPFSML(ctx->fi, LOGL_NOTICE, "Received CTRL message: type=%d %s %s: %s\n",
cmd->type, cmd->variable, cmd->id, osmo_escape_str(cmd->reply, -1));
if (cmd->type != CTRL_TYPE_GET_REPLY || !cmd->reply) {
osmo_fsm_inst_dispatch(ctx->fi, NACC_EV_RX_RAC_CI, NULL);
return;
}
/* Validate it's the seqnum from our last GET cmd, and not from older
* one we may have requested in case MS decided to resend Pkt Cell
* Change Notify with a different tgt cell:
*/
exp_id = arfcn_bsic_2_ctrl_id(ctx->neigh_key.tgt_arfcn, ctx->neigh_key.tgt_bsic);
if ((unsigned int)atoi(cmd->id) != exp_id) {
LOGPFSML(ctx->fi, LOGL_INFO,
"Received CTRL message with id=%s doesn't match our expected last id=%d, ignoring\n",
cmd->id, exp_id);
return;
}
/* TODO: Potentially validate cmd->variable contains same params as we
sent, and that cmd->id matches the original set. We may want to keep
the original cmd around by setting cmd->defer=1 when sending it. */
tmp = talloc_strdup(cmd, cmd->reply);
if (!tmp)
goto free_ret;
if (!(tok = strtok_r(tmp, "-", &saveptr)))
goto free_ret;
cgi_ps.rai.lac.plmn.mcc = atoi(tok);
if (!(tok = strtok_r(NULL, "-", &saveptr)))
goto free_ret;
cgi_ps.rai.lac.plmn.mnc = atoi(tok);
if (!(tok = strtok_r(NULL, "-", &saveptr)))
goto free_ret;
cgi_ps.rai.lac.lac = atoi(tok);
if (!(tok = strtok_r(NULL, "-", &saveptr)))
goto free_ret;
cgi_ps.rai.rac = atoi(tok);
if (!(tok = strtok_r(NULL, "\0", &saveptr)))
goto free_ret;
cgi_ps.cell_identity = atoi(tok);
/* Cache the cgi_ps so we can avoid requesting again same resolution for a while */
neigh_cache_add(ctx->ms->bts->pcu->neigh_cache, &ctx->neigh_key, &cgi_ps);
osmo_fsm_inst_dispatch(ctx->fi, NACC_EV_RX_RAC_CI, &cgi_ps);
return;
free_ret:
talloc_free(tmp);
osmo_fsm_inst_dispatch(ctx->fi, NACC_EV_RX_RAC_CI, NULL);
return;
}
static int nacc_fsm_ctx_talloc_destructor(struct nacc_fsm_ctx *ctx)
{
if (ctx->fi) {
osmo_fsm_inst_free(ctx->fi);
ctx->fi = NULL;
}
if (ctx->neigh_ctrl_conn) {
if (ctx->neigh_ctrl_conn->write_queue.bfd.fd != -1) {
osmo_wqueue_clear(&ctx->neigh_ctrl_conn->write_queue);
osmo_fd_unregister(&ctx->neigh_ctrl_conn->write_queue.bfd);
close(ctx->neigh_ctrl_conn->write_queue.bfd.fd);
ctx->neigh_ctrl_conn->write_queue.bfd.fd = -1;
}
}
return 0;
}
struct nacc_fsm_ctx *nacc_fsm_alloc(struct GprsMs* ms)
{
struct nacc_fsm_ctx *ctx = talloc_zero(ms, struct nacc_fsm_ctx);
char buf[64];
talloc_set_destructor(ctx, nacc_fsm_ctx_talloc_destructor);
ctx->ms = ms;
snprintf(buf, sizeof(buf), "TLLI-0x%08x", ms_tlli(ms));
ctx->fi = osmo_fsm_inst_alloc(&nacc_fsm, ctx, ctx, LOGL_INFO, buf);
if (!ctx->fi)
goto free_ret;
/* If CTRL ip present, use the old CTRL interface for neighbor resolution */
if (ms->bts->pcu->vty.neigh_ctrl_addr) {
ctx->neigh_ctrl = ctrl_handle_alloc(ctx, ctx, NULL);
ctx->neigh_ctrl->reply_cb = nacc_fsm_ctrl_reply_cb;
ctx->neigh_ctrl_conn = osmo_ctrl_conn_alloc(ctx, ctx->neigh_ctrl);
if (!ctx->neigh_ctrl_conn)
goto free_ret;
/* Older versions of osmo_ctrl_conn_alloc didn't properly initialize fd to -1,
* so make sure to do it here otherwise fd may be valid fd 0 and cause trouble */
ctx->neigh_ctrl_conn->write_queue.bfd.fd = -1;
llist_add(&ctx->neigh_ctrl_conn->list_entry, &ctx->neigh_ctrl->ccon_list);
}
return ctx;
free_ret:
talloc_free(ctx);
return NULL;
}
bool nacc_fsm_is_waiting_addr_resolution(const struct nacc_fsm_ctx *ctx,
const struct neigh_cache_entry_key *neigh_key)
{
if (ctx->fi->state != NACC_ST_WAIT_RESOLVE_RAC_CI)
return false;
return neigh_cache_entry_key_eq(&ctx->neigh_key, neigh_key);
}
bool nacc_fsm_is_waiting_si_resolution(const struct nacc_fsm_ctx *ctx,
const struct osmo_cell_global_id_ps *cgi_ps)
{
if (ctx->fi->state != NACC_ST_WAIT_REQUEST_SI)
return false;
return !osmo_cgi_ps_cmp(&ctx->cgi_ps, cgi_ps);
}
bool nacc_fsm_exp_ctrl_ack(const struct nacc_fsm_ctx *ctx, uint32_t fn, uint8_t ts)
{
return ctx->fi->state == NACC_ST_WAIT_CELL_CHG_CONTINUE_ACK &&
ctx->continue_poll_fn == fn &&
ctx->continue_poll_ts == ts;
}