diff options
Diffstat (limited to 'src/gb/bssgp_bvc_fsm.c')
| -rw-r--r-- | src/gb/bssgp_bvc_fsm.c | 857 |
1 files changed, 857 insertions, 0 deletions
diff --git a/src/gb/bssgp_bvc_fsm.c b/src/gb/bssgp_bvc_fsm.c new file mode 100644 index 00000000..3a36c7dc --- /dev/null +++ b/src/gb/bssgp_bvc_fsm.c @@ -0,0 +1,857 @@ +/* BSSGP per-BVC Finite State Machine */ + +/* (C) 2020 Harald Welte <laforge@gnumonks.org> + * + * All Rights Reserved + * + * SPDX-License-Identifier: GPL-2.0+ + * + * 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, see <http://www.gnu.org/licenses/>. + * + */ + +#include <string.h> +#include <stdio.h> + +#include <osmocom/core/fsm.h> +#include <osmocom/core/logging.h> +#include <osmocom/core/utils.h> +#include <osmocom/core/tdef.h> + +#include <osmocom/gsm/gsm48.h> +#include <osmocom/gsm/tlv.h> + +#include <osmocom/gprs/gprs_msgb.h> +#include <osmocom/gprs/gprs_bssgp.h> +#include <osmocom/gprs/gprs_bssgp2.h> +#include <osmocom/gprs/bssgp_bvc_fsm.h> + +#include "common_vty.h" + +#define S(x) (1 << (x)) + +/* TODO: Those are not made cofnigurable via a VTY yet */ +struct osmo_tdef bssgp_bvc_fsm_tdefs[] = { + { + .T = 1, + .default_val = 5, + .min_val = 1, + .max_val = 30, + .unit = OSMO_TDEF_S, + .desc = "Guards the BSSGP BVC (un)blocking procedure", + }, { + .T = 2, + .default_val = 10, + .min_val = 1, + .max_val = 120, + .unit = OSMO_TDEF_S, + .desc = "Guards the BSSGP BVC reset procedure", + }, { + .T = 3, + .default_val = 500, + .min_val = 100, + .max_val = 10000, + .unit = OSMO_TDEF_MS, + .desc = "Guards the BSSGP SUSPEND procedure", + }, { + .T = 4, + .default_val = 500, + .min_val = 100, + .max_val = 10000, + .unit = OSMO_TDEF_MS, + .desc = "Guards the BSSGP RESUME procedure", + }, { + .T = 5, + .default_val = 15, + .min_val = 1, + .max_val = 30, + .unit = OSMO_TDEF_S, + .desc = "Guards the BSSGP Radio Access Capability Update procedure", + }, + {} +}; + +#define T1 1 +#define T2 2 + +/* We cannot use osmo_tdef_fsm_* as it makes hard-coded assumptions that + * each new/target state will always use the same timer and timeout - or + * a timeout at all */ +#define T1_SECS osmo_tdef_get(bssgp_bvc_fsm_tdefs, 1, OSMO_TDEF_S, 5) +#define T2_SECS osmo_tdef_get(bssgp_bvc_fsm_tdefs, 2, OSMO_TDEF_S, 10) + +/* forward declaration */ +static struct osmo_fsm bssgp_bvc_fsm; + +static const struct value_string ptp_bvc_event_names[] = { + { BSSGP_BVCFSM_E_RX_BLOCK, "RX-BVC-BLOCK" }, + { BSSGP_BVCFSM_E_RX_BLOCK_ACK, "RX-BVC-BLOCK-ACK" }, + { BSSGP_BVCFSM_E_RX_UNBLOCK, "RX-BVC-UNBLOCK" }, + { BSSGP_BVCFSM_E_RX_UNBLOCK_ACK, "RX-BVC-UNBLOCK-ACK" }, + { BSSGP_BVCFSM_E_RX_RESET, "RX-BVC-RESET" }, + { BSSGP_BVCFSM_E_RX_RESET_ACK, "RX-BVC-RESET-ACK" }, + { BSSGP_BVCFSM_E_RX_FC_BVC, "RX-FLOW-CONTROL-BVC" }, + { BSSGP_BVCFSM_E_RX_FC_BVC_ACK, "RX-FLOW-CONTROL-BVC-ACK" }, + { BSSGP_BVCFSM_E_REQ_BLOCK, "REQ-BLOCK" }, + { BSSGP_BVCFSM_E_REQ_UNBLOCK, "REQ-UNBLOCK" }, + { BSSGP_BVCFSM_E_REQ_RESET, "REQ-RESET" }, + { BSSGP_BVCFSM_E_REQ_FC_BVC, "REQ-FLOW-CONTROL-BVC" }, + { 0, NULL } +}; + +struct bvc_fsm_priv { + /* NS-instance; defining the scope for NSEI below */ + struct gprs_ns2_inst *nsi; + + /* NSEI of the underlying NS Entity */ + uint16_t nsei; + /* Maximum size of the BSSGP PDU */ + uint16_t max_pdu_len; + + /* BVCI of this BVC */ + uint16_t bvci; + + /* are we the SGSN (true) or the BSS (false) */ + bool role_sgsn; + + /* BSS side: are we locally marked blocked? */ + bool locally_blocked; + uint8_t block_cause; + + /* cause value of the last outbound BVC-RESET (for re-transmissions) */ + uint8_t last_reset_cause; + + struct { + /* Bit 0..7: Features; Bit 8..15: Extended Features */ + uint32_t advertised; + uint32_t received; + uint32_t negotiated; + /* only used if BSSGP_XFEAT_GBIT is negotiated */ + enum bssgp_fc_granularity fc_granularity; + } features; + + /* Cell Identification used by BSS when + * transmitting BVC-RESET / BVC-RESET-ACK, or those received + * from BSS in SGSN role */ + struct gprs_ra_id ra_id; + uint16_t cell_id; + + /* call-backs provided by the user */ + const struct bssgp_bvc_fsm_ops *ops; + /* private data pointer passed to each call-back invocation */ + void *ops_priv; +}; + +static int fi_tx_ptp(struct osmo_fsm_inst *fi, struct msgb *msg) +{ + struct bssgp_normal_hdr *bgph = (struct bssgp_normal_hdr *) msgb_bssgph(msg); + struct bvc_fsm_priv *bfp = fi->priv; + + OSMO_ASSERT(fi->fsm == &bssgp_bvc_fsm); + + LOGPFSM(fi, "Tx BSSGP %s\n", osmo_tlv_prot_msg_name(&osmo_pdef_bssgp, bgph->pdu_type)); + + return bssgp2_nsi_tx_ptp(bfp->nsi, bfp->nsei, bfp->bvci, msg, 0); +} + +static int fi_tx_sig(struct osmo_fsm_inst *fi, struct msgb *msg) +{ + struct bssgp_normal_hdr *bgph = (struct bssgp_normal_hdr *) msgb_bssgph(msg); + struct bvc_fsm_priv *bfp = fi->priv; + + OSMO_ASSERT(fi->fsm == &bssgp_bvc_fsm); + + LOGPFSM(fi, "Tx BSSGP %s\n", osmo_tlv_prot_msg_name(&osmo_pdef_bssgp, bgph->pdu_type)); + + return bssgp2_nsi_tx_sig(bfp->nsi, bfp->nsei, msg, 0); +} + +/* helper function to transmit BVC-RESET with right combination of conditional/optional IEs */ +static void _tx_bvc_reset(struct osmo_fsm_inst *fi, uint8_t cause) +{ + struct bvc_fsm_priv *bfp = fi->priv; + const uint8_t *features = NULL; + const uint8_t *features_ext = NULL; + uint8_t _features[2] = { + (bfp->features.advertised >> 0) & 0xff, + (bfp->features.advertised >> 8) & 0xff, + }; + struct msgb *tx; + + OSMO_ASSERT(fi->fsm == &bssgp_bvc_fsm); + + /* transmit BVC-RESET to peer; RA-ID only present for PTP from BSS */ + if (bfp->bvci == 0) { + features = &_features[0]; + features_ext = &_features[1]; + } + tx = bssgp2_enc_bvc_reset(bfp->bvci, cause, + bfp->bvci && !bfp->role_sgsn ? &bfp->ra_id : NULL, + bfp->cell_id, features, features_ext); + fi_tx_sig(fi, tx); +} + +/* helper function to transmit BVC-RESET-ACK with right combination of conditional/optional IEs */ +static void _tx_bvc_reset_ack(struct osmo_fsm_inst *fi) +{ + struct bvc_fsm_priv *bfp = fi->priv; + const uint8_t *features = NULL; + const uint8_t *features_ext = NULL; + uint8_t _features[2] = { + (bfp->features.advertised >> 0) & 0xff, + (bfp->features.advertised >> 8) & 0xff, + }; + struct msgb *tx; + + OSMO_ASSERT(fi->fsm == &bssgp_bvc_fsm); + + /* transmit BVC-RESET-ACK to peer; RA-ID only present for PTP from BSS -> SGSN */ + if (bfp->bvci == 0) { + features = &_features[0]; + features_ext = &_features[1]; + } + tx = bssgp2_enc_bvc_reset_ack(bfp->bvci, bfp->bvci && !bfp->role_sgsn ? &bfp->ra_id : NULL, + bfp->cell_id, features, features_ext); + fi_tx_sig(fi, tx); +} + +/* helper function to transmit BVC-STATUS with right combination of conditional/optional IEs */ +static void _tx_status(struct osmo_fsm_inst *fi, enum gprs_bssgp_cause cause, const struct msgb *rx) +{ + struct bvc_fsm_priv *bfp = fi->priv; + struct msgb *tx; + uint16_t *bvci = NULL; + + /* GSM 08.18, 10.4.14.1: The BVCI must be included if (and only if) the + * cause is either "BVCI blocked" or "BVCI unknown" */ + if (cause == BSSGP_CAUSE_UNKNOWN_BVCI || cause == BSSGP_CAUSE_BVCI_BLOCKED) + bvci = &bfp->bvci; + + tx = bssgp2_enc_status(cause, bvci, rx, bfp->max_pdu_len); + + if (msgb_bvci(rx) == 0) + fi_tx_sig(fi, tx); + else + fi_tx_ptp(fi, tx); +} + +/* Update the features by bit-wise AND of advertised + received features */ +static void update_negotiated_features(struct osmo_fsm_inst *fi, const struct tlv_parsed *tp) +{ + struct bvc_fsm_priv *bfp = fi->priv; + + OSMO_ASSERT(fi->fsm == &bssgp_bvc_fsm); + + bfp->features.received = 0; + + if (TLVP_PRES_LEN(tp, BSSGP_IE_FEATURE_BITMAP, 1)) + bfp->features.received |= *TLVP_VAL(tp, BSSGP_IE_FEATURE_BITMAP); + + if (TLVP_PRES_LEN(tp, BSSGP_IE_EXT_FEATURE_BITMAP, 1)) + bfp->features.received |= (*TLVP_VAL(tp, BSSGP_IE_EXT_FEATURE_BITMAP) << 8); + + bfp->features.negotiated = bfp->features.advertised & bfp->features.received; + + LOGPFSML(fi, LOGL_NOTICE, "Updating features: Advertised 0x%04x, Received 0x%04x, Negotiated 0x%04x\n", + bfp->features.advertised, bfp->features.received, bfp->features.negotiated); +} + +/* "tail" of each onenter() handler: Calling the state change notification call-back */ +static void _onenter_tail(struct osmo_fsm_inst *fi, uint32_t prev_state) +{ + struct bvc_fsm_priv *bfp = fi->priv; + + if (prev_state == fi->state) + return; + + if (bfp->ops && bfp->ops->state_chg_notification) + bfp->ops->state_chg_notification(bfp->nsei, bfp->bvci, prev_state, fi->state, bfp->ops_priv); +} + +static void bssgp_bvc_fsm_null(struct osmo_fsm_inst *fi, uint32_t event, void *data) +{ + /* we don't really expect anything in this state; all handled via allstate */ + OSMO_ASSERT(0); +} + +static void bssgp_bvc_fsm_blocked_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state) +{ + struct bvc_fsm_priv *bfp = fi->priv; + /* signaling BVC can never be blocked */ + OSMO_ASSERT(bfp->bvci != 0); + _onenter_tail(fi, prev_state); +} + +static void bssgp_bvc_fsm_blocked(struct osmo_fsm_inst *fi, uint32_t event, void *data) +{ + struct bvc_fsm_priv *bfp = fi->priv; + struct msgb *rx = NULL, *tx; + const struct tlv_parsed *tp = NULL; + uint8_t cause; + + switch (event) { + case BSSGP_BVCFSM_E_RX_BLOCK_ACK: + rx = data; + tp = (const struct tlv_parsed *) msgb_bcid(rx); + /* If a BVC-BLOCK-ACK PDU is received by a BSS for the signalling BVC, the PDU is ignored. */ + if (bfp->bvci == 0) { + LOGPFSML(fi, LOGL_ERROR, "Rx BVC-BLOCK-ACK on BVCI=0 is illegal\n"); + if (!bfp->role_sgsn) + break; + _tx_status(fi, BSSGP_CAUSE_SEM_INCORR_PDU, rx); + break; + } + /* stop T1 timer */ + osmo_fsm_inst_state_chg(fi, BSSGP_BVCFSM_S_BLOCKED, 0, 0); + break; + case BSSGP_BVCFSM_E_RX_BLOCK: + rx = data; + tp = (const struct tlv_parsed *) msgb_bcid(rx); + cause = *TLVP_VAL(tp, BSSGP_IE_CAUSE); + LOGPFSML(fi, LOGL_NOTICE, "Rx BVC-BLOCK (cause=%s)\n", bssgp_cause_str(cause)); + /* If a BVC-BLOCK PDU is received by an SGSN for a blocked BVC, a BVC-BLOCK-ACK + * PDU shall be returned. */ + if (bfp->role_sgsn) { + /* If a BVC-BLOCK PDU is received by an SGSN for + * the signalling BVC, the PDU is ignored */ + if (bfp->bvci == 0) + break; + tx = bssgp2_enc_bvc_block_ack(bfp->bvci); + fi_tx_sig(fi, tx); + } + break; + case BSSGP_BVCFSM_E_RX_UNBLOCK: + rx = data; + tp = (const struct tlv_parsed *) msgb_bcid(rx); + LOGPFSML(fi, LOGL_NOTICE, "Rx BVC-UNBLOCK\n"); + if (bfp->bvci == 0) { + LOGPFSML(fi, LOGL_ERROR, "Rx BVC-UNBLOCK on BVCI=0 is illegal\n"); + /* If BVC-UNBLOCK PDU is received by an SGSN for the signalling BVC, the PDU is ignored.*/ + if (bfp->role_sgsn) + break; + _tx_status(fi, BSSGP_CAUSE_SEM_INCORR_PDU, rx); + break; + } + if (!bfp->role_sgsn) { + LOGPFSML(fi, LOGL_ERROR, "Rx BVC-UNBLOCK on BSS is illegal\n"); + _tx_status(fi, BSSGP_CAUSE_SEM_INCORR_PDU, rx); + break; + } + tx = bssgp2_enc_bvc_unblock_ack(bfp->bvci); + fi_tx_sig(fi, tx); + osmo_fsm_inst_state_chg(fi, BSSGP_BVCFSM_S_UNBLOCKED, T1_SECS, T1); + break; + case BSSGP_BVCFSM_E_REQ_UNBLOCK: + if (bfp->role_sgsn) { + LOGPFSML(fi, LOGL_ERROR, "SGSN side cannot initiate BVC unblock\n"); + break; + } + if (bfp->bvci == 0) { + LOGPFSML(fi, LOGL_ERROR, "BVCI 0 cannot be unblocked\n"); + break; + } + bfp->locally_blocked = false; + tx = bssgp2_enc_bvc_unblock(bfp->bvci); + fi_tx_sig(fi, tx); + osmo_fsm_inst_state_chg(fi, BSSGP_BVCFSM_S_UNBLOCKED, 0, 0); + break; + } +} + +/* Waiting for RESET-ACK: Receive PDUs but don't transmit */ +static void bssgp_bvc_fsm_wait_reset_ack(struct osmo_fsm_inst *fi, uint32_t event, void *data) +{ + struct bvc_fsm_priv *bfp = fi->priv; + const struct tlv_parsed *tp = NULL; + struct msgb *rx = NULL, *tx; + uint8_t cause; + + switch (event) { + case BSSGP_BVCFSM_E_RX_RESET: + /* 48.018 Section 8.4.3: If the BSS (or SGSN) has sent a BVC-RESET PDU for a BVCI to + * the SGSN (or BSS) and is awaiting a BVC-RESET-ACK PDU in response, but instead + * receives a BVC-RESET PDU indicating the same BVCI, then this shall be interpreted + * as a BVC-RESET ACK PDU and the T2 timer shall be stopped. */ + /* fall-through */ + case BSSGP_BVCFSM_E_RX_RESET_ACK: + rx = data; + cause = bfp->last_reset_cause; + tp = (const struct tlv_parsed *) msgb_bcid(rx); + if (bfp->bvci == 0) + update_negotiated_features(fi, tp); + if (bfp->role_sgsn && bfp->bvci != 0) + bfp->cell_id = bssgp_parse_cell_id(&bfp->ra_id, TLVP_VAL(tp, BSSGP_IE_CELL_ID)); + if (!bfp->role_sgsn && bfp->bvci != 0 && bfp->locally_blocked) { + /* initiate the blocking procedure */ + /* transmit BVC-BLOCK, transition to BLOCKED state and start re-transmit timer */ + tx = bssgp2_enc_bvc_block(bfp->bvci, bfp->block_cause); + fi_tx_sig(fi, tx); + osmo_fsm_inst_state_chg(fi, BSSGP_BVCFSM_S_BLOCKED, T1_SECS, T1); + } else + osmo_fsm_inst_state_chg(fi, BSSGP_BVCFSM_S_UNBLOCKED, 0, 0); + if (bfp->ops && bfp->ops->reset_ack_notification) + bfp->ops->reset_ack_notification(bfp->nsei, bfp->bvci, &bfp->ra_id, bfp->cell_id, cause, bfp->ops_priv); + break; + } +} + +static void bssgp_bvc_fsm_unblocked(struct osmo_fsm_inst *fi, uint32_t event, void *data) +{ + struct bssgp2_flow_ctrl rx_fc, *tx_fc; + struct bvc_fsm_priv *bfp = fi->priv; + const struct tlv_parsed *tp = NULL; + struct msgb *rx = NULL, *tx; + int rc; + + switch (event) { + case BSSGP_BVCFSM_E_RX_UNBLOCK_ACK: + rx = data; + tp = (const struct tlv_parsed *) msgb_bcid(rx); + /* If BVC-UNBLOCK-ACK PDU is received by an BSS for the signalling BVC, the PDU is ignored. */ + if (bfp->bvci == 0) { + LOGPFSML(fi, LOGL_ERROR, "Rx BVC-UNBLOCK-ACK on BVCI=0 is illegal\n"); + if (!bfp->role_sgsn) + break; + _tx_status(fi, BSSGP_CAUSE_SEM_INCORR_PDU, rx); + break; + } + /* stop T1 timer */ + osmo_fsm_inst_state_chg(fi, BSSGP_BVCFSM_S_UNBLOCKED, 0, 0); + break; + case BSSGP_BVCFSM_E_RX_UNBLOCK: + rx = data; + tp = (const struct tlv_parsed *) msgb_bcid(rx); + /* If a BVC-UNBLOCK PDU is received by an SGSN for a blocked BVC, a BVC-UNBLOCK-ACK + * PDU shall be returned. */ + if (bfp->role_sgsn) { + /* If a BVC-UNBLOCK PDU is received by an SGSN for + * the signalling BVC, the PDU is ignored */ + if (bfp->bvci == 0) + break; + bssgp_tx_simple_bvci(BSSGP_PDUT_BVC_UNBLOCK_ACK, bfp->nsei, bfp->bvci, 0); + } + break; + case BSSGP_BVCFSM_E_RX_BLOCK: + rx = data; + tp = (const struct tlv_parsed *) msgb_bcid(rx); + LOGPFSML(fi, LOGL_NOTICE, "Rx BVC-BLOCK (cause=%s)\n", + bssgp_cause_str(*TLVP_VAL(tp, BSSGP_IE_CAUSE))); + /* If a BVC-BLOCK PDU is received by an SGSN for the signalling BVC, the PDU is ignored */ + if (bfp->bvci == 0) { + LOGPFSML(fi, LOGL_ERROR, "Rx BVC-BLOCK on BVCI=0 is illegal\n"); + if (bfp->role_sgsn) + break; + _tx_status(fi, BSSGP_CAUSE_SEM_INCORR_PDU, rx); + break; + } + if (!bfp->role_sgsn) { + LOGPFSML(fi, LOGL_ERROR, "Rx BVC-BLOCK on BSS is illegal\n"); + _tx_status(fi, BSSGP_CAUSE_SEM_INCORR_PDU, rx); + break; + } + /* transmit BVC-BLOCK-ACK, transition to BLOCKED state */ + tx = bssgp2_enc_bvc_block_ack(bfp->bvci); + fi_tx_sig(fi, tx); + osmo_fsm_inst_state_chg(fi, BSSGP_BVCFSM_S_BLOCKED, 0, 0); + break; + case BSSGP_BVCFSM_E_REQ_BLOCK: + if (bfp->role_sgsn) { + LOGPFSML(fi, LOGL_ERROR, "SGSN may not initiate BVC-BLOCK\n"); + break; + } + if (bfp->bvci == 0) { + LOGPFSML(fi, LOGL_ERROR, "BVCI 0 cannot be blocked\n"); + break; + } + bfp->locally_blocked = true; + bfp->block_cause = *(uint8_t *)data; + /* transmit BVC-BLOCK, transition to BLOCKED state and start re-transmit timer */ + tx = bssgp2_enc_bvc_block(bfp->bvci, bfp->block_cause); + fi_tx_sig(fi, tx); + osmo_fsm_inst_state_chg(fi, BSSGP_BVCFSM_S_BLOCKED, T1_SECS, T1); + break; + case BSSGP_BVCFSM_E_RX_FC_BVC: + rx = data; + tp = (const struct tlv_parsed *) msgb_bcid(rx); + /* we assume osmo_tlv_prot_* has been used before calling here to ensure this */ + OSMO_ASSERT(bfp->role_sgsn); + rc = bssgp2_dec_fc_bvc(&rx_fc, tp); + if (rc < 0) { + _tx_status(fi, BSSGP_CAUSE_SEM_INCORR_PDU, rx); + break; + } + if (bfp->ops->rx_fc_bvc) + bfp->ops->rx_fc_bvc(bfp->nsei, bfp->bvci, &rx_fc, bfp->ops_priv); + tx = bssgp2_enc_fc_bvc_ack(rx_fc.tag); + fi_tx_ptp(fi, tx); + break; + case BSSGP_BVCFSM_E_RX_FC_BVC_ACK: + rx = data; + tp = (const struct tlv_parsed *) msgb_bcid(rx); + /* we assume osmo_tlv_prot_* has been used before calling here to ensure this */ + OSMO_ASSERT(!bfp->role_sgsn); + break; + case BSSGP_BVCFSM_E_REQ_FC_BVC: + tx_fc = data; + tx = bssgp2_enc_fc_bvc(tx_fc, bfp->features.negotiated & (BSSGP_XFEAT_GBIT << 8) ? + &bfp->features.fc_granularity : NULL); + fi_tx_ptp(fi, tx); + break; + } +} + +static void bssgp_bvc_fsm_allstate(struct osmo_fsm_inst *fi, uint32_t event, void *data) +{ + struct bvc_fsm_priv *bfp = fi->priv; + uint8_t cause; + const struct tlv_parsed *tp = NULL; + struct msgb *rx = NULL; + + switch (event) { + case BSSGP_BVCFSM_E_REQ_RESET: + bfp->locally_blocked = false; + cause = bfp->last_reset_cause = *(uint8_t *) data; + _tx_bvc_reset(fi, cause); + osmo_fsm_inst_state_chg(fi, BSSGP_BVCFSM_S_WAIT_RESET_ACK, T2_SECS, T2); +#if 0 /* not sure if we really should notify the application if itself has requested the reset? */ + if (bfp->ops && bfp->ops->reset_notification) + bfp->ops->reset_notification(bfp->nsei, bfp->bvci, NULL, 0, cause, bfp->ops_priv); +#endif + break; + case BSSGP_BVCFSM_E_RX_RESET: + rx = data; + tp = (const struct tlv_parsed *) msgb_bcid(rx); + cause = *TLVP_VAL(tp, BSSGP_IE_CAUSE); + if (bfp->role_sgsn && bfp->bvci != 0) + bfp->cell_id = bssgp_parse_cell_id(&bfp->ra_id, TLVP_VAL(tp, BSSGP_IE_CELL_ID)); + LOGPFSML(fi, LOGL_NOTICE, "Rx BVC-RESET (cause=%s)\n", bssgp_cause_str(cause)); + if (bfp->bvci == 0) + update_negotiated_features(fi, tp); + _tx_bvc_reset_ack(fi); + osmo_fsm_inst_state_chg(fi, BSSGP_BVCFSM_S_UNBLOCKED, 0, 0); + if (bfp->ops && bfp->ops->reset_notification) { + bfp->ops->reset_notification(bfp->nsei, bfp->bvci, &bfp->ra_id, bfp->cell_id, + cause, bfp->ops_priv); + } + break; + } +} + +static int bssgp_bvc_fsm_timer_cb(struct osmo_fsm_inst *fi) +{ + struct bvc_fsm_priv *bfp = fi->priv; + struct msgb *tx; + + switch (fi->T) { + case T1: + switch (fi->state) { + case BSSGP_BVCFSM_S_BLOCKED: + /* re-transmit BVC-BLOCK */ + tx = bssgp2_enc_bvc_block(bfp->bvci, bfp->block_cause); + fi_tx_sig(fi, tx); + osmo_fsm_inst_state_chg(fi, BSSGP_BVCFSM_S_BLOCKED, T1_SECS, T1); + break; + case BSSGP_BVCFSM_S_UNBLOCKED: + /* re-transmit BVC-UNBLOCK */ + tx = bssgp2_enc_bvc_unblock(bfp->bvci); + fi_tx_sig(fi, tx); + osmo_fsm_inst_state_chg(fi, BSSGP_BVCFSM_S_UNBLOCKED, T1_SECS, T1); + break; + } + break; + case T2: + switch (fi->state) { + case BSSGP_BVCFSM_S_WAIT_RESET_ACK: + /* re-transmit BVC-RESET */ + _tx_bvc_reset(fi, bfp->last_reset_cause); + osmo_fsm_inst_state_chg(fi, BSSGP_BVCFSM_S_WAIT_RESET_ACK, T2_SECS, T2); + break; + case BSSGP_BVCFSM_S_UNBLOCKED: + /* re-transmit BVC-RESET-ACK */ + _tx_bvc_reset_ack(fi); + osmo_fsm_inst_state_chg(fi, BSSGP_BVCFSM_S_UNBLOCKED, T2_SECS, T2); + break; + } + break; + default: + OSMO_ASSERT(0); + break; + } + return 0; +} + + + +static const struct osmo_fsm_state bssgp_bvc_fsm_states[] = { + [BSSGP_BVCFSM_S_NULL] = { + /* initial state from which we must do a RESET */ + .name = "NULL", + .in_event_mask = 0, + .out_state_mask = S(BSSGP_BVCFSM_S_WAIT_RESET_ACK) | + S(BSSGP_BVCFSM_S_UNBLOCKED), + .action = bssgp_bvc_fsm_null, + }, + [BSSGP_BVCFSM_S_BLOCKED] = { + .name = "BLOCKED", + .in_event_mask = S(BSSGP_BVCFSM_E_RX_UNBLOCK) | + S(BSSGP_BVCFSM_E_RX_BLOCK) | + S(BSSGP_BVCFSM_E_RX_BLOCK_ACK) | + S(BSSGP_BVCFSM_E_REQ_UNBLOCK), + .out_state_mask = S(BSSGP_BVCFSM_S_WAIT_RESET_ACK) | + S(BSSGP_BVCFSM_S_UNBLOCKED) | + S(BSSGP_BVCFSM_S_BLOCKED), + .action = bssgp_bvc_fsm_blocked, + .onenter = bssgp_bvc_fsm_blocked_onenter, + }, + [BSSGP_BVCFSM_S_WAIT_RESET_ACK]= { + .name = "WAIT_RESET_ACK", + .in_event_mask = S(BSSGP_BVCFSM_E_RX_RESET_ACK) | + S(BSSGP_BVCFSM_E_RX_RESET), + .out_state_mask = S(BSSGP_BVCFSM_S_UNBLOCKED) | + S(BSSGP_BVCFSM_S_BLOCKED) | + S(BSSGP_BVCFSM_S_WAIT_RESET_ACK), + .action = bssgp_bvc_fsm_wait_reset_ack, + .onenter = _onenter_tail, + }, + + [BSSGP_BVCFSM_S_UNBLOCKED] = { + .name = "UNBLOCKED", + .in_event_mask = S(BSSGP_BVCFSM_E_RX_BLOCK) | + S(BSSGP_BVCFSM_E_RX_UNBLOCK) | + S(BSSGP_BVCFSM_E_RX_UNBLOCK_ACK) | + S(BSSGP_BVCFSM_E_REQ_BLOCK) | + S(BSSGP_BVCFSM_E_RX_FC_BVC) | + S(BSSGP_BVCFSM_E_RX_FC_BVC_ACK) | + S(BSSGP_BVCFSM_E_REQ_FC_BVC), + .out_state_mask = S(BSSGP_BVCFSM_S_BLOCKED) | + S(BSSGP_BVCFSM_S_WAIT_RESET_ACK) | + S(BSSGP_BVCFSM_S_UNBLOCKED), + .action = bssgp_bvc_fsm_unblocked, + .onenter = _onenter_tail, + }, +}; + +static struct osmo_fsm bssgp_bvc_fsm = { + .name = "BSSGP-BVC", + .states = bssgp_bvc_fsm_states, + .num_states = ARRAY_SIZE(bssgp_bvc_fsm_states), + .allstate_event_mask = S(BSSGP_BVCFSM_E_REQ_RESET) | + S(BSSGP_BVCFSM_E_RX_RESET), + .allstate_action = bssgp_bvc_fsm_allstate, + .timer_cb = bssgp_bvc_fsm_timer_cb, + .log_subsys = DLBSSGP, + .event_names = ptp_bvc_event_names, +}; + +static struct osmo_fsm_inst * +_bvc_fsm_alloc(void *ctx, struct gprs_ns2_inst *nsi, bool role_sgsn, uint16_t nsei, uint16_t bvci) +{ + struct osmo_fsm_inst *fi; + struct bvc_fsm_priv *bfp; + char idbuf[64]; + + /* TODO: encode our role in the id string? */ + snprintf(idbuf, sizeof(idbuf), "NSE%05u-BVC%05u", nsei, bvci); + + fi = osmo_fsm_inst_alloc(&bssgp_bvc_fsm, ctx, NULL, LOGL_INFO, idbuf); + if (!fi) + return NULL; + + bfp = talloc_zero(fi, struct bvc_fsm_priv); + if (!bfp) { + osmo_fsm_inst_free(fi); + return NULL; + } + fi->priv = bfp; + + bfp->nsi = nsi; + bfp->role_sgsn = role_sgsn; + bfp->nsei = nsei; + bfp->bvci = bvci; + bfp->max_pdu_len = UINT16_MAX; + + return fi; +} + +/*! Allocate a SIGNALING-BVC FSM for the BSS role (facing a remote SGSN). + * \param[in] ctx talloc context from which to allocate + * \param[in] nsi NS Instance on which this BVC operates + * \param[in] nsei NS Entity Identifier on which this BVC operates + * \param[in] features Feature [byte 0] and Extended Feature [byte 1] bitmap + * \returns newly-allocated FSM Instance; NULL in case of error */ +struct osmo_fsm_inst * +bssgp_bvc_fsm_alloc_sig_bss(void *ctx, struct gprs_ns2_inst *nsi, uint16_t nsei, uint32_t features) +{ + struct osmo_fsm_inst *fi = _bvc_fsm_alloc(ctx, nsi, false, nsei, 0); + struct bvc_fsm_priv *bfp; + + if (!fi) + return NULL; + + bfp = fi->priv; + bfp->features.advertised = features; + + return fi; +} + +/*! Allocate a PTP-BVC FSM for the BSS role (facing a remote SGSN). + * \param[in] ctx talloc context from which to allocate + * \param[in] nsi NS Instance on which this BVC operates + * \param[in] nsei NS Entity Identifier on which this BVC operates + * \param[in] bvci BVCI of this FSM + * \param[in] ra_id Routing Area Identity of the cell (reported to SGSN) + * \param[in] cell_id Cell Identifier of the cell (reported to SGSN) + * \returns newly-allocated FSM Instance; NULL in case of error */ +struct osmo_fsm_inst * +bssgp_bvc_fsm_alloc_ptp_bss(void *ctx, struct gprs_ns2_inst *nsi, uint16_t nsei, + uint16_t bvci, const struct gprs_ra_id *ra_id, uint16_t cell_id) +{ + struct osmo_fsm_inst *fi; + struct bvc_fsm_priv *bfp; + + OSMO_ASSERT(bvci >= 2); + OSMO_ASSERT(ra_id); + + fi = _bvc_fsm_alloc(ctx, nsi, false, nsei, bvci); + if (!fi) + return NULL; + + bfp = fi->priv; + bfp->ra_id = *ra_id; + bfp->cell_id = cell_id; + + return fi; +} + +/*! Allocate a SIGNALING-BVC FSM for the SGSN role (facing a remote BSS). + * \param[in] ctx talloc context from which to allocate + * \param[in] nsi NS Instance on which this BVC operates + * \param[in] nsei NS Entity Identifier on which this BVC operates + * \param[in] features Feature [byte 0] and Extended Feature [byte 1] bitmap + * \returns newly-allocated FSM Instance; NULL in case of error */ +struct osmo_fsm_inst * +bssgp_bvc_fsm_alloc_sig_sgsn(void *ctx, struct gprs_ns2_inst *nsi, uint16_t nsei, uint32_t features) +{ + struct osmo_fsm_inst *fi = _bvc_fsm_alloc(ctx, nsi, true, nsei, 0); + struct bvc_fsm_priv *bfp; + + if (!fi) + return NULL; + + bfp = fi->priv; + bfp->features.advertised = features; + + return fi; +} + +/*! Allocate a PTP-BVC FSM for the SGSN role (facing a remote BSS). + * \param[in] ctx talloc context from which to allocate + * \param[in] nsi NS Instance on which this BVC operates + * \param[in] nsei NS Entity Identifier on which this BVC operates + * \param[in] bvci BVCI of this FSM + * \returns newly-allocated FSM Instance; NULL in case of error */ +struct osmo_fsm_inst * +bssgp_bvc_fsm_alloc_ptp_sgsn(void *ctx, struct gprs_ns2_inst *nsi, uint16_t nsei, uint16_t bvci) +{ + struct osmo_fsm_inst *fi; + + OSMO_ASSERT(bvci >= 2); + + fi = _bvc_fsm_alloc(ctx, nsi, true, nsei, bvci); + if (!fi) + return NULL; + + return fi; +} + +/*! Set the 'operations' callbacks + private data. + * \param[in] fi FSM instance for which the data shall be set + * \param[in] ops BSSGP BVC FSM operations (call-back functions) to register + * \param[in] ops_priv opaque/private data pointer passed through to call-backs */ +void bssgp_bvc_fsm_set_ops(struct osmo_fsm_inst *fi, const struct bssgp_bvc_fsm_ops *ops, void *ops_priv) +{ + struct bvc_fsm_priv *bfp = fi->priv; + + OSMO_ASSERT(fi->fsm == &bssgp_bvc_fsm); + + bfp->ops = ops; + bfp->ops_priv = ops_priv; +} + +/*! Return if the given BVC FSM is in UNBLOCKED state. */ +bool bssgp_bvc_fsm_is_unblocked(struct osmo_fsm_inst *fi) +{ + return fi->state == BSSGP_BVCFSM_S_UNBLOCKED; +} + +/*! Determine the cause value why given BVC FSM is blocked. */ +uint8_t bssgp_bvc_fsm_get_block_cause(struct osmo_fsm_inst *fi) +{ + struct bvc_fsm_priv *bfp = fi->priv; + + OSMO_ASSERT(fi->fsm == &bssgp_bvc_fsm); + return bfp->block_cause; +} + +/*! Return the advertised features / extended features. */ +uint32_t bssgp_bvc_fsm_get_features_advertised(struct osmo_fsm_inst *fi) +{ + struct bvc_fsm_priv *bfp = fi->priv; + + OSMO_ASSERT(fi->fsm == &bssgp_bvc_fsm); + return bfp->features.advertised; +} + +/*! Return the received features / extended features. */ +uint32_t bssgp_bvc_fsm_get_features_received(struct osmo_fsm_inst *fi) +{ + struct bvc_fsm_priv *bfp = fi->priv; + + OSMO_ASSERT(fi->fsm == &bssgp_bvc_fsm); + return bfp->features.received; +} + +/*! Return the negotiated features / extended features. */ +uint32_t bssgp_bvc_fsm_get_features_negotiated(struct osmo_fsm_inst *fi) +{ + struct bvc_fsm_priv *bfp = fi->priv; + + OSMO_ASSERT(fi->fsm == &bssgp_bvc_fsm); + return bfp->features.negotiated; +} + +/*! Set the maximum size of a BSSGP PDU. + *! On the NS layer this corresponds to the size of an NS SDU in NS-UNITDATA (3GPP TS 48.016 Ch. 9.2.10) */ +void bssgp_bvc_fsm_set_max_pdu_len(struct osmo_fsm_inst *fi, uint16_t max_pdu_len) { + struct bvc_fsm_priv *bfp = fi->priv; + + OSMO_ASSERT(fi->fsm == &bssgp_bvc_fsm); + bfp->max_pdu_len = max_pdu_len; +} + +/*! Return the maximum size of a BSSGP PDU + *! On the NS layer this corresponds to the size of an NS SDU in NS-UNITDATA (3GPP TS 48.016 Ch. 9.2.10) */ +uint16_t bssgp_bvc_fsm_get_max_pdu_len(const struct osmo_fsm_inst *fi) +{ + const struct bvc_fsm_priv *bfp = fi->priv; + + OSMO_ASSERT(fi->fsm == &bssgp_bvc_fsm); + return bfp->max_pdu_len; +} + + +static __attribute__((constructor)) void on_dso_load_bvc_fsm(void) +{ + OSMO_ASSERT(osmo_fsm_register(&bssgp_bvc_fsm) == 0); +} |