BSSGP: Add functions required for true BSS-side BSSGP implementation
The BSS-side of BSSGP requires quite a number of additional functions
for sending unidirectional messages that a SGSN never sends.
This is a first step into completing the BSSGP implementation and making
it ready to be used from osmo-bts and other BTS-side GPRS
implementations.
diff --git a/openbsc/src/libgb/gprs_bssgp_bss.c b/openbsc/src/libgb/gprs_bssgp_bss.c
new file mode 100644
index 0000000..9d76c3a
--- /dev/null
+++ b/openbsc/src/libgb/gprs_bssgp_bss.c
@@ -0,0 +1,426 @@
+/* GPRS BSSGP protocol implementation as per 3GPP TS 08.18 */
+
+/* (C) 2009-2011 by Harald Welte <laforge@gnumonks.org>
+ *
+ * All Rights Reserved
+ *
+ * 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 <errno.h>
+#include <stdint.h>
+
+#include <netinet/in.h>
+
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/rate_ctr.h>
+#include <osmocom/gsm/tlv.h>
+#include <osmocom/core/talloc.h>
+
+#include <openbsc/debug.h>
+#include <openbsc/gsm_data.h>
+#include <openbsc/gprs_bssgp.h>
+#include <openbsc/gprs_ns.h>
+
+uint8_t *bssgp_msgb_tlli_put(struct msgb *msg, uint32_t tlli)
+{
+ uint32_t _tlli = htonl(tlli);
+ return msgb_tvlv_put(msg, BSSGP_IE_TLLI, 4, (uint8_t *) &_tlli);
+}
+
+/*! \brief GMM-SUSPEND.req (Chapter 10.3.6) */
+int bssgp_tx_suspend(uint16_t nsei, uint32_t tlli,
+ const struct gprs_ra_id *ra_id)
+{
+ struct msgb *msg = bssgp_msgb_alloc();
+ struct bssgp_normal_hdr *bgph =
+ (struct bssgp_normal_hdr *) msgb_put(msg, sizeof(*bgph));
+ uint8_t ra[6];
+
+ LOGP(DBSSGP, LOGL_NOTICE, "BSSGP (BVCI=0) Tx SUSPEND (TLLI=0x%04x)\n",
+ tlli);
+ msgb_nsei(msg) = nsei;
+ msgb_bvci(msg) = 0; /* Signalling */
+ bgph->pdu_type = BSSGP_PDUT_SUSPEND;
+
+ bssgp_msgb_tlli_put(msg, tlli);
+
+ gsm48_construct_ra(ra, ra_id);
+ msgb_tvlv_put(msg, BSSGP_IE_ROUTEING_AREA, 6, ra);
+
+ return gprs_ns_sendmsg(bssgp_nsi, msg);
+}
+
+/*! \brief GMM-RESUME.req (Chapter 10.3.9) */
+int bssgp_tx_resume(uint16_t nsei, uint32_t tlli,
+ const struct gprs_ra_id *ra_id, uint8_t suspend_ref)
+{
+ struct msgb *msg = bssgp_msgb_alloc();
+ struct bssgp_normal_hdr *bgph =
+ (struct bssgp_normal_hdr *) msgb_put(msg, sizeof(*bgph));
+ uint8_t ra[6];
+
+ LOGP(DBSSGP, LOGL_NOTICE, "BSSGP (BVCI=0) Tx RESUME (TLLI=0x%04x)\n",
+ tlli);
+ msgb_nsei(msg) = nsei;
+ msgb_bvci(msg) = 0; /* Signalling */
+ bgph->pdu_type = BSSGP_PDUT_RESUME;
+
+ bssgp_msgb_tlli_put(msg, tlli);
+
+ gsm48_construct_ra(ra, ra_id);
+ msgb_tvlv_put(msg, BSSGP_IE_ROUTEING_AREA, 6, ra);
+
+ msgb_tvlv_put(msg, BSSGP_IE_SUSPEND_REF_NR, 1, &suspend_ref);
+
+ return gprs_ns_sendmsg(bssgp_nsi, msg);
+}
+
+/*! \brief Transmit RA-CAPABILITY-UPDATE (10.3.3) */
+int bssgp_tx_ra_capa_upd(struct bssgp_bvc_ctx *bctx, uint32_t tlli, uint8_t tag)
+{
+ struct msgb *msg = bssgp_msgb_alloc();
+ struct bssgp_normal_hdr *bgph =
+ (struct bssgp_normal_hdr *) msgb_put(msg, sizeof(*bgph));
+
+ LOGP(DBSSGP, LOGL_NOTICE, "BSSGP (BVCI=%u) Tx RA-CAPA-UPD (TLLI=0x%04x)\n",
+ bctx->bvci, tlli);
+
+ /* set NSEI and BVCI in msgb cb */
+ msgb_nsei(msg) = bctx->nsei;
+ msgb_bvci(msg) = bctx->bvci;
+
+ bgph->pdu_type = BSSGP_PDUT_RA_CAPA_UDPATE;
+ bssgp_msgb_tlli_put(msg, tlli);
+
+ msgb_tvlv_put(msg, BSSGP_IE_TAG, 1, &tag);
+
+ return gprs_ns_sendmsg(bssgp_nsi, msg);
+}
+
+/* first common part of RADIO-STATUS */
+static struct msgb *common_tx_radio_status(struct bssgp_bvc_ctx *bctx)
+{
+ struct msgb *msg = bssgp_msgb_alloc();
+ struct bssgp_normal_hdr *bgph =
+ (struct bssgp_normal_hdr *) msgb_put(msg, sizeof(*bgph));
+
+ LOGP(DBSSGP, LOGL_NOTICE, "BSSGP (BVCI=%u) Tx RADIO-STATUS ",
+ bctx->bvci);
+
+ /* set NSEI and BVCI in msgb cb */
+ msgb_nsei(msg) = bctx->nsei;
+ msgb_bvci(msg) = bctx->bvci;
+
+ bgph->pdu_type = BSSGP_PDUT_RADIO_STATUS;
+
+ return msg;
+}
+
+/* second common part of RADIO-STATUS */
+static int common_tx_radio_status2(struct msgb *msg, uint8_t cause)
+{
+ msgb_tvlv_put(msg, BSSGP_IE_CAUSE, 1, &cause);
+ LOGPC(DBSSGP, LOGL_NOTICE, "CAUSE=%u\n", cause);
+
+ return gprs_ns_sendmsg(bssgp_nsi, msg);
+}
+
+/*! \brief Transmit RADIO-STATUS for TLLI (10.3.5) */
+int bssgp_tx_radio_status_tlli(struct bssgp_bvc_ctx *bctx, uint8_t cause,
+ uint32_t tlli)
+{
+ struct msgb *msg = common_tx_radio_status(bctx);
+
+ if (!msg)
+ return -ENOMEM;
+ bssgp_msgb_tlli_put(msg, tlli);
+ LOGPC(DBSSGP, LOGL_NOTICE, "TLLI=0x%08x ", tlli);
+
+ return common_tx_radio_status2(msg, cause);
+}
+
+/*! \brief Transmit RADIO-STATUS for TMSI (10.3.5) */
+int bssgp_tx_radio_status_tmsi(struct bssgp_bvc_ctx *bctx, uint8_t cause,
+ uint32_t tmsi)
+{
+ struct msgb *msg = common_tx_radio_status(bctx);
+ uint32_t _tmsi = htonl(tmsi);
+
+ if (!msg)
+ return -ENOMEM;
+ msgb_tvlv_put(msg, BSSGP_IE_TMSI, 4, (uint8_t *)&_tmsi);
+ LOGPC(DBSSGP, LOGL_NOTICE, "TMSI=0x%08x ", tmsi);
+
+ return common_tx_radio_status2(msg, cause);
+}
+
+/*! \brief Transmit RADIO-STATUS for IMSI (10.3.5) */
+int bssgp_tx_radio_status_imsi(struct bssgp_bvc_ctx *bctx, uint8_t cause,
+ const char *imsi)
+{
+ struct msgb *msg = common_tx_radio_status(bctx);
+ uint8_t mi[10];
+ int imsi_len = gsm48_generate_mid_from_imsi(mi, imsi);
+
+ if (!msg)
+ return -ENOMEM;
+
+ /* strip the MI type and length values (2 bytes) */
+ if (imsi_len > 2)
+ msgb_tvlv_put(msg, BSSGP_IE_IMSI, imsi_len-2, mi+2);
+ LOGPC(DBSSGP, LOGL_NOTICE, "IMSI=%s ", imsi);
+
+ return common_tx_radio_status2(msg, cause);
+}
+
+/*! \brief Transmit FLUSH-LL-ACK (Chapter 10.4.2) */
+int bssgp_tx_flush_ll_ack(struct bssgp_bvc_ctx *bctx, uint32_t tlli,
+ uint8_t action, uint16_t bvci_new,
+ uint32_t num_octets)
+{
+ struct msgb *msg = bssgp_msgb_alloc();
+ struct bssgp_normal_hdr *bgph =
+ (struct bssgp_normal_hdr *) msgb_put(msg, sizeof(*bgph));
+ uint16_t _bvci_new = htons(bvci_new);
+ uint32_t _oct_aff = htonl(num_octets & 0xFFFFFF);
+
+ msgb_nsei(msg) = bctx->nsei;
+ msgb_bvci(msg) = 0; /* Signalling */
+ bgph->pdu_type = BSSGP_PDUT_FLUSH_LL_ACK;
+
+ bssgp_msgb_tlli_put(msg, tlli);
+ msgb_tvlv_put(msg, BSSGP_IE_FLUSH_ACTION, 1, &action);
+ if (action == 1) /* transferred */
+ msgb_tvlv_put(msg, BSSGP_IE_BVCI, 2, (uint8_t *) &_bvci_new);
+ msgb_tvlv_put(msg, BSSGP_IE_NUM_OCT_AFF, 3, (uint8_t *) &_oct_aff);
+
+ return gprs_ns_sendmsg(bssgp_nsi, msg);
+}
+
+/*! \brief Transmit LLC-DISCARDED (Chapter 10.4.3) */
+int bssgp_tx_llc_discarded(struct bssgp_bvc_ctx *bctx, uint32_t tlli,
+ uint8_t num_frames, uint32_t num_octets)
+{
+ struct msgb *msg = bssgp_msgb_alloc();
+ struct bssgp_normal_hdr *bgph =
+ (struct bssgp_normal_hdr *) msgb_put(msg, sizeof(*bgph));
+ uint16_t _bvci = htons(bctx->bvci);
+ uint32_t _oct_aff = htonl(num_octets & 0xFFFFFF);
+
+ LOGP(DBSSGP, LOGL_NOTICE, "BSSGP (BVCI=%u) Tx LLC-DISCARDED "
+ "TLLI=0x%04x, FRAMES=%u, OCTETS=%u\n", bctx->bvci, tlli,
+ num_frames, num_octets);
+ msgb_nsei(msg) = bctx->nsei;
+ msgb_bvci(msg) = 0; /* Signalling */
+ bgph->pdu_type = BSSGP_PDUT_LLC_DISCARD;
+
+ bssgp_msgb_tlli_put(msg, tlli);
+
+ msgb_tvlv_put(msg, BSSGP_IE_LLC_FRAMES_DISCARDED, 1, &num_frames);
+ msgb_tvlv_put(msg, BSSGP_IE_BVCI, 2, (uint8_t *) &_bvci);
+ msgb_tvlv_put(msg, BSSGP_IE_NUM_OCT_AFF, 3, (uint8_t *) &_oct_aff);
+
+ return gprs_ns_sendmsg(bssgp_nsi, msg);
+}
+
+/*! \brief Transmit a BVC-BLOCK message (Chapter 10.4.8) */
+int bssgp_tx_bvc_block(struct bssgp_bvc_ctx *bctx, uint8_t cause)
+{
+ struct msgb *msg = bssgp_msgb_alloc();
+ struct bssgp_normal_hdr *bgph =
+ (struct bssgp_normal_hdr *) msgb_put(msg, sizeof(*bgph));
+ uint16_t _bvci = htons(bctx->bvci);
+
+ LOGP(DBSSGP, LOGL_NOTICE, "BSSGP (BVCI=%u) Tx BVC-BLOCK "
+ "CAUSE=%u\n", bctx->bvci, cause);
+
+ msgb_nsei(msg) = bctx->nsei;
+ msgb_bvci(msg) = 0; /* Signalling */
+ bgph->pdu_type = BSSGP_PDUT_BVC_BLOCK;
+
+ msgb_tvlv_put(msg, BSSGP_IE_BVCI, 2, (uint8_t *) &_bvci);
+ msgb_tvlv_put(msg, BSSGP_IE_CAUSE, 1, &cause);
+
+ return gprs_ns_sendmsg(bssgp_nsi, msg);
+}
+
+/*! \brief Transmit a BVC-UNBLOCK message (Chapter 10.4.10) */
+int bssgp_tx_bvc_unblock(struct bssgp_bvc_ctx *bctx)
+{
+ struct msgb *msg = bssgp_msgb_alloc();
+ struct bssgp_normal_hdr *bgph =
+ (struct bssgp_normal_hdr *) msgb_put(msg, sizeof(*bgph));
+ uint16_t _bvci = htons(bctx->bvci);
+
+ LOGP(DBSSGP, LOGL_NOTICE, "BSSGP (BVCI=%u) Tx BVC-BLOCK\n", bctx->bvci);
+
+ msgb_nsei(msg) = bctx->nsei;
+ msgb_bvci(msg) = 0; /* Signalling */
+ bgph->pdu_type = BSSGP_PDUT_BVC_UNBLOCK;
+
+ msgb_tvlv_put(msg, BSSGP_IE_BVCI, 2, (uint8_t *) &_bvci);
+
+ return gprs_ns_sendmsg(bssgp_nsi, msg);
+}
+
+/*! \brief Transmit a BVC-RESET message (Chapter 10.4.12) */
+int bssgp_tx_bvc_reset(struct bssgp_bvc_ctx *bctx, uint16_t bvci, uint8_t cause)
+{
+ struct msgb *msg = bssgp_msgb_alloc();
+ struct bssgp_normal_hdr *bgph =
+ (struct bssgp_normal_hdr *) msgb_put(msg, sizeof(*bgph));
+ uint16_t _bvci = htons(bvci);
+
+ LOGP(DBSSGP, LOGL_NOTICE, "BSSGP (BVCI=%u) Tx BVC-RESET "
+ "CAUSE=%u\n", bvci, cause);
+
+ msgb_nsei(msg) = bctx->nsei;
+ msgb_bvci(msg) = 0; /* Signalling */
+ bgph->pdu_type = BSSGP_PDUT_BVC_RESET;
+
+ msgb_tvlv_put(msg, BSSGP_IE_BVCI, 2, (uint8_t *) &_bvci);
+ msgb_tvlv_put(msg, BSSGP_IE_CAUSE, 1, &cause);
+ if (bvci != BVCI_PTM) {
+ uint8_t bssgp_cid[8];
+ bssgp_create_cell_id(bssgp_cid, &bctx->ra_id, bctx->cell_id);
+ msgb_tvlv_put(msg, BSSGP_IE_CELL_ID, sizeof(bssgp_cid), bssgp_cid);
+ }
+ /* Optional: Feature Bitmap */
+
+ return gprs_ns_sendmsg(bssgp_nsi, msg);
+}
+
+
+/*! \brief RL-UL-UNITDATA.req (Chapter 10.2.2) */
+int bssgp_tx_ul_ud(struct bssgp_bvc_ctx *bctx, uint32_t tlli,
+ const uint8_t *qos_profile, struct msgb *llc_pdu)
+{
+ struct msgb *msg = llc_pdu;
+ uint8_t bssgp_cid[8];
+ struct bssgp_ud_hdr *budh;
+
+ /* FIXME: First push alignment octets, if rqd */
+
+ /* FIXME: Optional LSA Identifier List, PFI */
+
+ /* Cell Identifier */
+ bssgp_create_cell_id(bssgp_cid, &bctx->ra_id, bctx->cell_id);
+ msgb_tvlv_push(msg, BSSGP_IE_CELL_ID, sizeof(bssgp_cid), bssgp_cid);
+
+ /* User Data Header */
+ budh = (struct bssgp_ud_hdr *) msgb_push(msg, sizeof(*budh));
+ budh->tlli = htonl(tlli);
+ memcpy(budh->qos_profile, qos_profile, 3);
+ budh->pdu_type = BSSGP_PDUT_UL_UNITDATA;
+
+ /* set NSEI and BVCI in msgb cb */
+ msgb_nsei(msg) = bctx->nsei;
+ msgb_bvci(msg) = bctx->bvci;
+
+ rate_ctr_inc(&bctx->ctrg->ctr[BSSGP_CTR_PKTS_OUT]);
+ rate_ctr_add(&bctx->ctrg->ctr[BSSGP_CTR_BYTES_OUT], msg->len);
+
+ return gprs_ns_sendmsg(bssgp_nsi, msg);
+}
+
+/* Parse a single GMM-PAGING.req to a given NSEI/NS-BVCI */
+int gprs_bssgp_rx_paging(struct bssgp_paging_info *pinfo,
+ struct msgb *msg)
+{
+ struct bssgp_normal_hdr *bgph =
+ (struct bssgp_normal_hdr *) msgb_bssgph(msg);
+ struct tlv_parsed tp;
+ uint8_t ra[6];
+ int rc, data_len;
+
+ memset(ra, 0, sizeof(ra));
+
+ data_len = msgb_bssgp_len(msg) - sizeof(*bgph);
+ rc = bssgp_tlv_parse(&tp, bgph->data, data_len);
+ if (rc < 0)
+ goto err_mand_ie;
+
+ switch (bgph->pdu_type) {
+ case BSSGP_PDUT_PAGING_PS:
+ pinfo->mode = BSSGP_PAGING_PS;
+ break;
+ case BSSGP_PDUT_PAGING_CS:
+ pinfo->mode = BSSGP_PAGING_CS;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /* IMSI */
+ if (!TLVP_PRESENT(&tp, BSSGP_IE_IMSI))
+ goto err_mand_ie;
+ if (!pinfo->imsi)
+ pinfo->imsi = talloc_zero_size(pinfo, 16);
+ gsm48_mi_to_string(pinfo->imsi, sizeof(pinfo->imsi),
+ TLVP_VAL(&tp, BSSGP_IE_IMSI),
+ TLVP_LEN(&tp, BSSGP_IE_IMSI));
+
+ /* DRX Parameters */
+ if (!TLVP_PRESENT(&tp, BSSGP_IE_DRX_PARAMS))
+ goto err_mand_ie;
+ pinfo->drx_params = ntohs(*(uint16_t *)TLVP_VAL(&tp, BSSGP_IE_DRX_PARAMS));
+
+ /* Scope */
+ if (TLVP_PRESENT(&tp, BSSGP_IE_BSS_AREA_ID)) {
+ pinfo->scope = BSSGP_PAGING_BSS_AREA;
+ } else if (TLVP_PRESENT(&tp, BSSGP_IE_LOCATION_AREA)) {
+ pinfo->scope = BSSGP_PAGING_LOCATION_AREA;
+ memcpy(ra, TLVP_VAL(&tp, BSSGP_IE_LOCATION_AREA),
+ TLVP_LEN(&tp, BSSGP_IE_LOCATION_AREA));
+ gsm48_parse_ra(&pinfo->raid, ra);
+ } else if (TLVP_PRESENT(&tp, BSSGP_IE_ROUTEING_AREA)) {
+ pinfo->scope = BSSGP_PAGING_ROUTEING_AREA;
+ memcpy(ra, TLVP_VAL(&tp, BSSGP_IE_ROUTEING_AREA),
+ TLVP_LEN(&tp, BSSGP_IE_ROUTEING_AREA));
+ gsm48_parse_ra(&pinfo->raid, ra);
+ } else if (TLVP_PRESENT(&tp, BSSGP_IE_BVCI)) {
+ pinfo->scope = BSSGP_PAGING_BVCI;
+ pinfo->bvci = ntohs(*(uint16_t *)TLVP_VAL(&tp, BSSGP_IE_BVCI));
+ } else
+ return -EINVAL;
+
+ /* QoS profile mandatory for PS */
+ if (pinfo->mode == BSSGP_PAGING_PS) {
+ if (!TLVP_PRESENT(&tp, BSSGP_IE_QOS_PROFILE))
+ goto err_cond_ie;
+ if (TLVP_LEN(&tp, BSSGP_IE_QOS_PROFILE) < 3)
+ goto err;
+
+ memcpy(&pinfo->qos, TLVP_VAL(&tp, BSSGP_IE_QOS_PROFILE),
+ 3);
+ }
+
+ /* Optional (P-)TMSI */
+ if (TLVP_PRESENT(&tp, BSSGP_IE_TMSI) &&
+ TLVP_LEN(&tp, BSSGP_IE_TMSI) >= 4)
+ if (!pinfo->ptmsi)
+ pinfo->ptmsi = talloc_zero_size(pinfo, sizeof(uint32_t));
+ *(pinfo->ptmsi) = ntohl(*(uint32_t *)
+ TLVP_VAL(&tp, BSSGP_IE_TMSI));
+
+ return 0;
+
+err_mand_ie:
+err_cond_ie:
+err:
+ /* FIXME */
+ return 0;
+}