diff options
Diffstat (limited to 'bssgp.cpp')
| -rw-r--r-- | bssgp.cpp | 363 |
1 files changed, 363 insertions, 0 deletions
diff --git a/bssgp.cpp b/bssgp.cpp new file mode 100644 index 00000000..dd773df4 --- /dev/null +++ b/bssgp.cpp @@ -0,0 +1,363 @@ +/* bssgp.cpp + * + * Copyright (C) 2011 Ivan Klyuchnikov + * + * 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 <arpa/inet.h> +#include <Threads.h> +#include "GPRSSocket.h" +#include "bssgp.h" + +// TODO: We should move this parameters to config file. +#define SGSN_IP "127.0.0.1" +#define SGSN_PORT 23000 +#define CELL_ID 3 +#define BVCI 7 +#define NSEI 3 +#define NSVCI 4 +#define MNC 1 +#define MCC 1 +#define LAC 1000 +#define RAC 1 + +#define QOS_PROFILE 0 +#define BSSGP_HDR_LEN 20 +#define NS_HDR_LEN 4 +#define MAX_LEN_PDU 100 +#define IE_PDU 14 +#define BLOCK_DATA_LEN 16 + +#define BLOCK_LEN 23 + +uint16_t bvci = BVCI; +uint16_t nsei = NSEI; +uint8_t TFI; +struct bssgp_bvc_ctx *bctx = btsctx_alloc(bvci, nsei); +struct gprs_nsvc *nsvc; +struct gprs_ns_inst *sgsn_nsi; +struct sgsn_instance *sgsn; +void *tall_bsc_ctx; + +// Send RLC data to OpenBTS. +void sendRLC(uint32_t tlli, uint8_t *pdu, unsigned startIndex, unsigned endIndex) +{ + unsigned wp = 0; + BitVector resultVector(BLOCK_LEN*8); + resultVector.unhex("2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b"); + // TODO: Encode downlink RLC/MAC data block. + sendToOpenBTS(&resultVector); +} + +/* Receive a BSSGP PDU from a BSS on a PTP BVCI */ +int gprs_bssgp_bss_rx_ptp(struct msgb *msg, struct tlv_parsed *tp, struct bssgp_bvc_ctx *bctx) +{ + struct bssgp_normal_hdr *bgph = (struct bssgp_normal_hdr *) msgb_bssgph(msg); + uint8_t pdu_type = bgph->pdu_type; + uint8_t pdu[MAX_LEN_PDU]; + unsigned rc = 0; + unsigned dataIndex = 0; + unsigned numBlocks = 0; + unsigned i = 0; + unsigned j = 0; + unsigned pduIndex = 0; + struct bssgp_ud_hdr *budh; + + /* If traffic is received on a BVC that is marked as blocked, the + * received PDU shall not be accepted and a STATUS PDU (Cause value: + * BVC Blocked) shall be sent to the peer entity on the signalling BVC */ + if (bctx->state & BVC_S_BLOCKED && pdu_type != BSSGP_PDUT_STATUS) + { + uint16_t bvci = msgb_bvci(msg); + LOGP(DBSSGP, LOGL_NOTICE, "rx BVC_S_BLOCKED\n"); + return bssgp_tx_status(BSSGP_CAUSE_BVCI_BLOCKED, &bvci, msg); + } + + switch (pdu_type) { + case BSSGP_PDUT_DL_UNITDATA: + LOGP(DBSSGP, LOGL_NOTICE, "rx BSSGP_PDUT_DL_UNITDATA\n"); + budh = (struct bssgp_ud_hdr *) msgb_bssgph(msg); + LOGP(DBSSGP, LOGL_NOTICE, "rx BSSGP TLLI=0x%08x \n", ntohl(budh->tlli)); + for (i = 4; i < MAX_LEN_PDU; i++) + { + LOGP(DBSSGP, LOGL_NOTICE, "SERCH data = -0x%02x\n", budh ->data[i]); + if(budh ->data[i] == IE_PDU) + { + pduIndex = i+2; + break; + } + } + for (i = pduIndex; i < pduIndex + (budh->data[pduIndex-1]&0x7f); i++) + { + LOGP(DBSSGP, LOGL_NOTICE, "-0x%02x\n", budh ->data[i]); + pdu[dataIndex] = budh ->data[i]; + dataIndex++; + } + DEBUGP(DBSSGP, "BSSGP Catch from SGSN=%u octets. Send it to OpenBTS.\n", dataIndex); + if (dataIndex > BLOCK_DATA_LEN) + { + int blockDataLen = BLOCK_DATA_LEN; + numBlocks = dataIndex/BLOCK_DATA_LEN; + int ost = dataIndex%BLOCK_DATA_LEN; + int startIndex = 0; + int endIndex = 0; + if (dataIndex%BLOCK_DATA_LEN > 0) + { + numBlocks++; + } + for (i = 0; i < numBlocks; i++) + { + if (i == numBlocks-1) + { + blockDataLen = ost; + } + endIndex = startIndex+blockDataLen; + sendRLC(ntohl(budh->tlli), pdu, startIndex, endIndex); + startIndex += blockDataLen; + } + } + else + { + sendRLC(ntohl(budh->tlli), pdu, 0, dataIndex); + } + break; + case BSSGP_PDUT_PAGING_PS: + LOGP(DBSSGP, LOGL_NOTICE, "rx BSSGP_PDUT_PAGING_PS\n"); + break; + case BSSGP_PDUT_PAGING_CS: + LOGP(DBSSGP, LOGL_NOTICE, "rx BSSGP_PDUT_PAGING_CS\n"); + break; + case BSSGP_PDUT_RA_CAPA_UPDATE_ACK: + LOGP(DBSSGP, LOGL_NOTICE, "rx BSSGP_PDUT_RA_CAPA_UPDATE_ACK\n"); + break; + case BSSGP_PDUT_FLOW_CONTROL_BVC_ACK: + LOGP(DBSSGP, LOGL_NOTICE, "rx BSSGP_PDUT_FLOW_CONTROL_BVC_ACK\n"); + break; + case BSSGP_PDUT_FLOW_CONTROL_MS_ACK: + LOGP(DBSSGP, LOGL_NOTICE, "rx BSSGP_PDUT_FLOW_CONTROL_MS_ACK\n"); + break; + default: + DEBUGP(DBSSGP, "BSSGP BVCI=%u PDU type 0x%02x unknown\n", bctx->bvci, pdu_type); + rc = bssgp_tx_status(BSSGP_CAUSE_PROTO_ERR_UNSPEC, NULL, msg); + break; + } + return rc; +} + +/* Receive a BSSGP PDU from a SGSN on a SIGNALLING BVCI */ +int gprs_bssgp_bss_rx_sign(struct msgb *msg, struct tlv_parsed *tp, struct bssgp_bvc_ctx *bctx) +{ + struct bssgp_normal_hdr *bgph = (struct bssgp_normal_hdr *) msgb_bssgph(msg); + int rc = 0; + switch (bgph->pdu_type) { + case BSSGP_PDUT_STATUS: + /* Some exception has occurred */ + DEBUGP(DBSSGP, "BSSGP BVCI=%u Rx BVC STATUS\n", bctx->bvci); + /* FIXME: send NM_STATUS.ind to NM */ + break; + case BSSGP_PDUT_SUSPEND_ACK: + LOGP(DBSSGP, LOGL_NOTICE, "rx BSSGP_PDUT_SUSPEND_ACK\n"); + break; + case BSSGP_PDUT_SUSPEND_NACK: + LOGP(DBSSGP, LOGL_NOTICE, "rx BSSGP_PDUT_SUSPEND_NACK\n"); + break; + case BSSGP_PDUT_BVC_RESET_ACK: + LOGP(DBSSGP, LOGL_NOTICE, "rx BSSGP_PDUT_BVC_RESET_ACK\n"); + break; + case BSSGP_PDUT_PAGING_PS: + LOGP(DBSSGP, LOGL_NOTICE, "rx BSSGP_PDUT_PAGING_PS\n"); + break; + case BSSGP_PDUT_PAGING_CS: + LOGP(DBSSGP, LOGL_NOTICE, "rx BSSGP_PDUT_PAGING_CS\n"); + break; + case BSSGP_PDUT_RESUME_ACK: + LOGP(DBSSGP, LOGL_NOTICE, "rx BSSGP_PDUT_RESUME_ACK\n"); + break; + case BSSGP_PDUT_RESUME_NACK: + LOGP(DBSSGP, LOGL_NOTICE, "rx BSSGP_PDUT_RESUME_NACK\n"); + break; + case BSSGP_PDUT_FLUSH_LL: + LOGP(DBSSGP, LOGL_NOTICE, "rx BSSGP_PDUT_FLUSH_LL\n"); + break; + case BSSGP_PDUT_BVC_BLOCK_ACK: + LOGP(DBSSGP, LOGL_NOTICE, "rx BSSGP_PDUT_SUSPEND_ACK\n"); + break; + case BSSGP_PDUT_BVC_UNBLOCK_ACK: + LOGP(DBSSGP, LOGL_NOTICE, "rx BSSGP_PDUT_BVC_UNBLOCK_ACK\n"); + break; + case BSSGP_PDUT_SGSN_INVOKE_TRACE: + LOGP(DBSSGP, LOGL_NOTICE, "rx BSSGP_PDUT_SGSN_INVOKE_TRACE\n"); + break; + default: + DEBUGP(DBSSGP, "BSSGP BVCI=%u Rx PDU type 0x%02x unknown\n", bctx->bvci, bgph->pdu_type); + rc = bssgp_tx_status(BSSGP_CAUSE_PROTO_ERR_UNSPEC, NULL, msg); + break; + } + return rc; +} + +int gprs_bssgp_bss_rcvmsg(struct msgb *msg) +{ + struct bssgp_normal_hdr *bgph = (struct bssgp_normal_hdr *) msgb_bssgph(msg); + struct bssgp_ud_hdr *budh = (struct bssgp_ud_hdr *) msgb_bssgph(msg); + struct tlv_parsed tp; + uint8_t pdu_type = bgph->pdu_type; + uint16_t ns_bvci = msgb_bvci(msg); + int data_len; + int rc = 0; + + /* Identifiers from DOWN: NSEI, BVCI (both in msg->cb) */ + + /* UNITDATA BSSGP headers have TLLI in front */ + if (pdu_type != BSSGP_PDUT_UL_UNITDATA && pdu_type != BSSGP_PDUT_DL_UNITDATA) + { + data_len = msgb_bssgp_len(msg) - sizeof(*bgph); + rc = bssgp_tlv_parse(&tp, bgph->data, data_len); + } + else + { + data_len = msgb_bssgp_len(msg) - sizeof(*budh); + rc = bssgp_tlv_parse(&tp, budh->data, data_len); + } + + /* look-up or create the BTS context for this BVC */ + bctx = btsctx_by_bvci_nsei(ns_bvci, msgb_nsei(msg)); + + /* Only a RESET PDU can create a new BVC context */ + if (!bctx) + { + bctx = btsctx_alloc(ns_bvci, msgb_nsei(msg)); + } + + if (!bctx && pdu_type != BSSGP_PDUT_BVC_RESET_ACK) + { + LOGP(DBSSGP, LOGL_NOTICE, "NSEI=%u/BVCI=%u Rejecting PDU " + "type %u for unknown BVCI\n", msgb_nsei(msg), ns_bvci, + pdu_type); + return bssgp_tx_status(BSSGP_CAUSE_UNKNOWN_BVCI, NULL, msg); + } + + if (bctx) + { + log_set_context(BSC_CTX_BVC, bctx); + rate_ctr_inc(&bctx->ctrg->ctr[BSSGP_CTR_PKTS_IN]); + rate_ctr_add(&bctx->ctrg->ctr[BSSGP_CTR_BYTES_IN], msgb_bssgp_len(msg)); + } + + if (ns_bvci == BVCI_SIGNALLING) + { + LOGP(DBSSGP, LOGL_NOTICE, "rx BVCI_SIGNALLING gprs_bssgp_rx_sign\n"); + rc = gprs_bssgp_bss_rx_sign(msg, &tp, bctx); + } + else if (ns_bvci == BVCI_PTM) + { + LOGP(DBSSGP, LOGL_NOTICE, "rx BVCI_PTM bssgp_tx_status\n"); + rc = bssgp_tx_status(BSSGP_CAUSE_PDU_INCOMP_FEAT, NULL, msg); + } + else + { + LOGP(DBSSGP, LOGL_NOTICE, "rx BVCI_PTP gprs_bssgp_rx_ptp\n"); + rc = gprs_bssgp_bss_rx_ptp(msg, &tp, bctx); + } + return rc; +} + + +int sgsn_ns_cb(enum gprs_ns_evt event, struct gprs_nsvc *nsvc, struct msgb *msg, uint16_t bvci) +{ + int rc = 0; + switch (event) { + case GPRS_NS_EVT_UNIT_DATA: + /* hand the message into the BSSGP implementation */ + rc = gprs_bssgp_bss_rcvmsg(msg); + break; + default: + LOGP(DGPRS, LOGL_ERROR, "RLCMAC: Unknown event %u from NS\n", event); + if (msg) + talloc_free(msg); + rc = -EIO; + break; + } + return rc; +} + +// Send RLC data to SGSN. +void sendToSGSN(uint8_t tfi, uint32_t tlli, uint8_t * rlc_data, unsigned dataLen) +{ + const uint8_t qos_profile = QOS_PROFILE; + struct msgb *llc_pdu; + unsigned msgLen = NS_HDR_LEN + BSSGP_HDR_LEN + dataLen; + TFI = tfi; + bctx->cell_id = CELL_ID; + bctx->nsei = NSEI; + bctx->ra_id.mnc = MNC; + bctx->ra_id.mcc = MCC; + bctx->ra_id.lac = LAC; + bctx->ra_id.rac = RAC; + bctx->bvci = BVCI; + LOGP(DBSSGP, LOGL_DEBUG, "Data len %u TLLI 0x%08x , TFI 0x%02x", dataLen, tlli, tfi); + //for (unsigned i = 0; i < dataLen; i++) + // LOGP(DBSSGP, LOGL_DEBUG, " Data[%u] = %u", i, rlc_data[i]); + llc_pdu = msgb_alloc_headroom(msgLen, msgLen,"llc_pdu"); + msgb_tvlv_push(llc_pdu, BSSGP_IE_LLC_PDU, sizeof(uint8_t)*dataLen, rlc_data); + bssgp_tx_ul_ud(bctx, tlli, &qos_profile, llc_pdu); +} + +void RLCMACServer() +{ + uint16_t nsvci = NSVCI; + + // Socket for reading BitVectors (RLC/MAC Frames) from OpenBTS application. + Thread RLCMACInterface; + RLCMACInterface.start(RLCMACSocket,NULL); + + osmo_init_logging(&log_info); + sgsn_nsi = gprs_ns_instantiate(&sgsn_ns_cb); + bssgp_nsi = sgsn_nsi; + + if (!bssgp_nsi) + { + LOGP(DGPRS, LOGL_ERROR, "Unable to instantiate NS\n"); + exit(1); + } + + bctx->cell_id = CELL_ID; + bctx->nsei = NSEI; + bctx->ra_id.mnc = MNC; + bctx->ra_id.mcc = MCC; + bctx->ra_id.lac = LAC; + bctx->ra_id.rac = RAC; + bctx->bvci = BVCI; + uint8_t cause = 39; + gprs_ns_nsip_listen(sgsn_nsi); + + struct sockaddr_in dest; + dest.sin_family = AF_INET; + dest.sin_port = htons(SGSN_PORT); + inet_aton(SGSN_IP, &dest.sin_addr); + + nsvc = nsip_connect(sgsn_nsi, &dest, nsei, nsvci); + unsigned i = 0; + while (1) + { + osmo_select_main(0); + if (i == 7) + { + bssgp_tx_bvc_reset(bctx, nsvc, bvci, cause); + } + i++; + } +} |