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libosmocore/openbsc/src/libgb/gprs_bssgp.c

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/* GPRS BSSGP protocol implementation as per 3GPP TS 08.18 */
/* (C) 2009-2012 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/>.
*
* TODO:
* o properly count incoming BVC-RESET packets in counter group
* o set log context as early as possible for outgoing packets
*/
#include <errno.h>
#include <stdint.h>
#include <netinet/in.h>
#include <osmocom/core/msgb.h>
#include <osmocom/gsm/tlv.h>
#include <osmocom/core/talloc.h>
#include <osmocom/core/rate_ctr.h>
#include <openbsc/debug.h>
#include <openbsc/gsm_04_08_gprs.h>
#include <osmocom/gprs/gprs_bssgp.h>
#include <osmocom/gprs/gprs_ns.h>
#include <openbsc/gprs_gmm.h>
void *bssgp_tall_ctx = NULL;
static const struct rate_ctr_desc bssgp_ctr_description[] = {
{ "packets.in", "Packets at BSSGP Level ( In)" },
{ "packets.out","Packets at BSSGP Level (Out)" },
{ "bytes.in", "Bytes at BSSGP Level ( In)" },
{ "bytes.out", "Bytes at BSSGP Level (Out)" },
{ "blocked", "BVC Blocking count" },
{ "discarded", "BVC LLC Discarded count" },
};
static const struct rate_ctr_group_desc bssgp_ctrg_desc = {
.group_name_prefix = "bssgp.bss_ctx",
.group_description = "BSSGP Peer Statistics",
.num_ctr = ARRAY_SIZE(bssgp_ctr_description),
.ctr_desc = bssgp_ctr_description,
};
LLIST_HEAD(bssgp_bvc_ctxts);
/* Find a BTS Context based on parsed RA ID and Cell ID */
struct bssgp_bvc_ctx *btsctx_by_raid_cid(const struct gprs_ra_id *raid, uint16_t cid)
{
struct bssgp_bvc_ctx *bctx;
llist_for_each_entry(bctx, &bssgp_bvc_ctxts, list) {
if (!memcmp(&bctx->ra_id, raid, sizeof(bctx->ra_id)) &&
bctx->cell_id == cid)
return bctx;
}
return NULL;
}
/* Find a BTS context based on BVCI+NSEI tuple */
struct bssgp_bvc_ctx *btsctx_by_bvci_nsei(uint16_t bvci, uint16_t nsei)
{
struct bssgp_bvc_ctx *bctx;
llist_for_each_entry(bctx, &bssgp_bvc_ctxts, list) {
if (bctx->nsei == nsei && bctx->bvci == bvci)
return bctx;
}
return NULL;
}
struct bssgp_bvc_ctx *btsctx_alloc(uint16_t bvci, uint16_t nsei)
{
struct bssgp_bvc_ctx *ctx;
ctx = talloc_zero(bssgp_tall_ctx, struct bssgp_bvc_ctx);
if (!ctx)
return NULL;
ctx->bvci = bvci;
ctx->nsei = nsei;
/* FIXME: BVCI is not unique, only BVCI+NSEI ?!? */
ctx->ctrg = rate_ctr_group_alloc(ctx, &bssgp_ctrg_desc, bvci);
llist_add(&ctx->list, &bssgp_bvc_ctxts);
return ctx;
}
/* Chapter 10.4.5: Flow Control BVC ACK */
static int bssgp_tx_fc_bvc_ack(uint16_t nsei, uint8_t tag, uint16_t ns_bvci)
{
struct msgb *msg = bssgp_msgb_alloc();
struct bssgp_normal_hdr *bgph =
(struct bssgp_normal_hdr *) msgb_put(msg, sizeof(*bgph));
msgb_nsei(msg) = nsei;
msgb_bvci(msg) = ns_bvci;
bgph->pdu_type = BSSGP_PDUT_FLOW_CONTROL_BVC_ACK;
msgb_tvlv_put(msg, BSSGP_IE_TAG, 1, &tag);
return gprs_ns_sendmsg(bssgp_nsi, msg);
}
/* 10.3.7 SUSPEND-ACK PDU */
int bssgp_tx_suspend_ack(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));
uint32_t _tlli;
uint8_t ra[6];
msgb_nsei(msg) = nsei;
msgb_bvci(msg) = 0; /* Signalling */
bgph->pdu_type = BSSGP_PDUT_SUSPEND_ACK;
_tlli = htonl(tlli);
msgb_tvlv_put(msg, BSSGP_IE_TLLI, 4, (uint8_t *) &_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);
}
/* 10.3.8 SUSPEND-NACK PDU */
int bssgp_tx_suspend_nack(uint16_t nsei, uint32_t tlli,
const struct gprs_ra_id *ra_id,
uint8_t *cause)
{
struct msgb *msg = bssgp_msgb_alloc();
struct bssgp_normal_hdr *bgph =
(struct bssgp_normal_hdr *) msgb_put(msg, sizeof(*bgph));
uint32_t _tlli;
uint8_t ra[6];
msgb_nsei(msg) = nsei;
msgb_bvci(msg) = 0; /* Signalling */
bgph->pdu_type = BSSGP_PDUT_SUSPEND_NACK;
_tlli = htonl(tlli);
msgb_tvlv_put(msg, BSSGP_IE_TLLI, 4, (uint8_t *) &_tlli);
gsm48_construct_ra(ra, ra_id);
msgb_tvlv_put(msg, BSSGP_IE_ROUTEING_AREA, 6, ra);
if (cause)
msgb_tvlv_put(msg, BSSGP_IE_CAUSE, 1, cause);
return gprs_ns_sendmsg(bssgp_nsi, msg);
}
/* 10.3.10 RESUME-ACK PDU */
int bssgp_tx_resume_ack(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));
uint32_t _tlli;
uint8_t ra[6];
msgb_nsei(msg) = nsei;
msgb_bvci(msg) = 0; /* Signalling */
bgph->pdu_type = BSSGP_PDUT_RESUME_ACK;
_tlli = htonl(tlli);
msgb_tvlv_put(msg, BSSGP_IE_TLLI, 4, (uint8_t *) &_tlli);
gsm48_construct_ra(ra, ra_id);
msgb_tvlv_put(msg, BSSGP_IE_ROUTEING_AREA, 6, ra);
return gprs_ns_sendmsg(bssgp_nsi, msg);
}
/* 10.3.11 RESUME-NACK PDU */
int bssgp_tx_resume_nack(uint16_t nsei, uint32_t tlli,
const struct gprs_ra_id *ra_id, uint8_t *cause)
{
struct msgb *msg = bssgp_msgb_alloc();
struct bssgp_normal_hdr *bgph =
(struct bssgp_normal_hdr *) msgb_put(msg, sizeof(*bgph));
uint32_t _tlli;
uint8_t ra[6];
msgb_nsei(msg) = nsei;
msgb_bvci(msg) = 0; /* Signalling */
bgph->pdu_type = BSSGP_PDUT_SUSPEND_NACK;
_tlli = htonl(tlli);
msgb_tvlv_put(msg, BSSGP_IE_TLLI, 4, (uint8_t *) &_tlli);
gsm48_construct_ra(ra, ra_id);
msgb_tvlv_put(msg, BSSGP_IE_ROUTEING_AREA, 6, ra);
if (cause)
msgb_tvlv_put(msg, BSSGP_IE_CAUSE, 1, cause);
return gprs_ns_sendmsg(bssgp_nsi, msg);
}
uint16_t bssgp_parse_cell_id(struct gprs_ra_id *raid, const uint8_t *buf)
{
/* 6 octets RAC */
gsm48_parse_ra(raid, buf);
/* 2 octets CID */
return ntohs(*(uint16_t *) (buf+6));
}
int bssgp_create_cell_id(uint8_t *buf, const struct gprs_ra_id *raid,
uint16_t cid)
{
uint16_t *out_cid = (uint16_t *) (buf + 6);
/* 6 octets RAC */
gsm48_construct_ra(buf, raid);
/* 2 octets CID */
*out_cid = htons(cid);
return 8;
}
/* Chapter 8.4 BVC-Reset Procedure */
static int bssgp_rx_bvc_reset(struct msgb *msg, struct tlv_parsed *tp,
uint16_t ns_bvci)
{
struct bssgp_bvc_ctx *bctx;
uint16_t nsei = msgb_nsei(msg);
uint16_t bvci;
int rc;
bvci = ntohs(*(uint16_t *)TLVP_VAL(tp, BSSGP_IE_BVCI));
DEBUGP(DBSSGP, "BSSGP BVCI=%u Rx RESET cause=%s\n", bvci,
bssgp_cause_str(*TLVP_VAL(tp, BSSGP_IE_CAUSE)));
/* look-up or create the BTS context for this BVC */
bctx = btsctx_by_bvci_nsei(bvci, nsei);
if (!bctx)
bctx = btsctx_alloc(bvci, nsei);
/* As opposed to NS-VCs, BVCs are NOT blocked after RESET */
bctx->state &= ~BVC_S_BLOCKED;
/* When we receive a BVC-RESET PDU (at least of a PTP BVCI), the BSS
* informs us about its RAC + Cell ID, so we can create a mapping */
if (bvci != 0 && bvci != 1) {
if (!TLVP_PRESENT(tp, BSSGP_IE_CELL_ID)) {
LOGP(DBSSGP, LOGL_ERROR, "BSSGP BVCI=%u Rx RESET "
"missing mandatory IE\n", bvci);
return -EINVAL;
}
/* actually extract RAC / CID */
bctx->cell_id = bssgp_parse_cell_id(&bctx->ra_id,
TLVP_VAL(tp, BSSGP_IE_CELL_ID));
LOGP(DBSSGP, LOGL_NOTICE, "Cell %u-%u-%u-%u CI %u on BVCI %u\n",
bctx->ra_id.mcc, bctx->ra_id.mnc, bctx->ra_id.lac,
bctx->ra_id.rac, bctx->cell_id, bvci);
}
/* Acknowledge the RESET to the BTS */
rc = bssgp_tx_simple_bvci(BSSGP_PDUT_BVC_RESET_ACK,
nsei, bvci, ns_bvci);
return 0;
}
static int bssgp_rx_bvc_block(struct msgb *msg, struct tlv_parsed *tp)
{
uint16_t bvci;
struct bssgp_bvc_ctx *ptp_ctx;
bvci = ntohs(*(uint16_t *)TLVP_VAL(tp, BSSGP_IE_BVCI));
if (bvci == BVCI_SIGNALLING) {
/* 8.3.2: Signalling BVC shall never be blocked */
LOGP(DBSSGP, LOGL_ERROR, "NSEI=%u/BVCI=%u "
"received block for signalling BVC!?!\n",
msgb_nsei(msg), msgb_bvci(msg));
return 0;
}
LOGP(DBSSGP, LOGL_INFO, "BSSGP Rx BVCI=%u BVC-BLOCK\n", bvci);
ptp_ctx = btsctx_by_bvci_nsei(bvci, msgb_nsei(msg));
if (!ptp_ctx)
return bssgp_tx_status(BSSGP_CAUSE_UNKNOWN_BVCI, &bvci, msg);
ptp_ctx->state |= BVC_S_BLOCKED;
rate_ctr_inc(&ptp_ctx->ctrg->ctr[BSSGP_CTR_BLOCKED]);
/* FIXME: Send NM_BVC_BLOCK.ind to NM */
/* We always acknowledge the BLOCKing */
return bssgp_tx_simple_bvci(BSSGP_PDUT_BVC_BLOCK_ACK, msgb_nsei(msg),
bvci, msgb_bvci(msg));
};
static int bssgp_rx_bvc_unblock(struct msgb *msg, struct tlv_parsed *tp)
{
uint16_t bvci;
struct bssgp_bvc_ctx *ptp_ctx;
bvci = ntohs(*(uint16_t *)TLVP_VAL(tp, BSSGP_IE_BVCI));
if (bvci == BVCI_SIGNALLING) {
/* 8.3.2: Signalling BVC shall never be blocked */
LOGP(DBSSGP, LOGL_ERROR, "NSEI=%u/BVCI=%u "
"received unblock for signalling BVC!?!\n",
msgb_nsei(msg), msgb_bvci(msg));
return 0;
}
DEBUGP(DBSSGP, "BSSGP BVCI=%u Rx BVC-UNBLOCK\n", bvci);
ptp_ctx = btsctx_by_bvci_nsei(bvci, msgb_nsei(msg));
if (!ptp_ctx)
return bssgp_tx_status(BSSGP_CAUSE_UNKNOWN_BVCI, &bvci, msg);
ptp_ctx->state &= ~BVC_S_BLOCKED;
/* FIXME: Send NM_BVC_UNBLOCK.ind to NM */
/* We always acknowledge the unBLOCKing */
return bssgp_tx_simple_bvci(BSSGP_PDUT_BVC_UNBLOCK_ACK, msgb_nsei(msg),
bvci, msgb_bvci(msg));
};
/* Uplink unit-data */
static int bssgp_rx_ul_ud(struct msgb *msg, struct tlv_parsed *tp,
struct bssgp_bvc_ctx *ctx)
{
struct bssgp_ud_hdr *budh = (struct bssgp_ud_hdr *) msgb_bssgph(msg);
/* extract TLLI and parse TLV IEs */
msgb_tlli(msg) = ntohl(budh->tlli);
DEBUGP(DBSSGP, "BSSGP TLLI=0x%08x Rx UPLINK-UNITDATA\n", msgb_tlli(msg));
/* Cell ID and LLC_PDU are the only mandatory IE */
if (!TLVP_PRESENT(tp, BSSGP_IE_CELL_ID) ||
!TLVP_PRESENT(tp, BSSGP_IE_LLC_PDU)) {
LOGP(DBSSGP, LOGL_ERROR, "BSSGP TLLI=0x%08x Rx UL-UD "
"missing mandatory IE\n", msgb_tlli(msg));
return bssgp_tx_status(BSSGP_CAUSE_MISSING_MAND_IE, NULL, msg);
}
/* store pointer to LLC header and CELL ID in msgb->cb */
msgb_llch(msg) = (uint8_t *) TLVP_VAL(tp, BSSGP_IE_LLC_PDU);
msgb_bcid(msg) = (uint8_t *) TLVP_VAL(tp, BSSGP_IE_CELL_ID);
return gprs_llc_rcvmsg(msg, tp);
}
static int bssgp_rx_suspend(struct msgb *msg, struct tlv_parsed *tp,
struct bssgp_bvc_ctx *ctx)
{
struct bssgp_normal_hdr *bgph =
(struct bssgp_normal_hdr *) msgb_bssgph(msg);
struct gprs_ra_id raid;
uint32_t tlli;
int rc;
if (!TLVP_PRESENT(tp, BSSGP_IE_TLLI) ||
!TLVP_PRESENT(tp, BSSGP_IE_ROUTEING_AREA)) {
LOGP(DBSSGP, LOGL_ERROR, "BSSGP BVCI=%u Rx SUSPEND "
"missing mandatory IE\n", ctx->bvci);
return bssgp_tx_status(BSSGP_CAUSE_MISSING_MAND_IE, NULL, msg);
}
tlli = ntohl(*(uint32_t *)TLVP_VAL(tp, BSSGP_IE_TLLI));
DEBUGP(DBSSGP, "BSSGP BVCI=%u TLLI=0x%08x Rx SUSPEND\n",
ctx->bvci, tlli);
gsm48_parse_ra(&raid, TLVP_VAL(tp, BSSGP_IE_ROUTEING_AREA));
/* Inform GMM about the SUSPEND request */
rc = gprs_gmm_rx_suspend(&raid, tlli);
if (rc < 0)
return bssgp_tx_suspend_nack(msgb_nsei(msg), tlli, &raid, NULL);
bssgp_tx_suspend_ack(msgb_nsei(msg), tlli, &raid, 0);
return 0;
}
static int bssgp_rx_resume(struct msgb *msg, struct tlv_parsed *tp,
struct bssgp_bvc_ctx *ctx)
{
struct bssgp_normal_hdr *bgph =
(struct bssgp_normal_hdr *) msgb_bssgph(msg);
struct gprs_ra_id raid;
uint32_t tlli;
uint8_t suspend_ref;
int rc;
if (!TLVP_PRESENT(tp, BSSGP_IE_TLLI) ||
!TLVP_PRESENT(tp, BSSGP_IE_ROUTEING_AREA) ||
!TLVP_PRESENT(tp, BSSGP_IE_SUSPEND_REF_NR)) {
LOGP(DBSSGP, LOGL_ERROR, "BSSGP BVCI=%u Rx RESUME "
"missing mandatory IE\n", ctx->bvci);
return bssgp_tx_status(BSSGP_CAUSE_MISSING_MAND_IE, NULL, msg);
}
tlli = ntohl(*(uint32_t *)TLVP_VAL(tp, BSSGP_IE_TLLI));
suspend_ref = *TLVP_VAL(tp, BSSGP_IE_SUSPEND_REF_NR);
DEBUGP(DBSSGP, "BSSGP BVCI=%u TLLI=0x%08x Rx RESUME\n", ctx->bvci, tlli);
gsm48_parse_ra(&raid, TLVP_VAL(tp, BSSGP_IE_ROUTEING_AREA));
/* Inform GMM about the RESUME request */
rc = gprs_gmm_rx_resume(&raid, tlli, suspend_ref);
if (rc < 0)
return bssgp_tx_resume_nack(msgb_nsei(msg), tlli, &raid,
NULL);
bssgp_tx_resume_ack(msgb_nsei(msg), tlli, &raid);
return 0;
}
static int bssgp_rx_llc_disc(struct msgb *msg, struct tlv_parsed *tp,
struct bssgp_bvc_ctx *ctx)
{
uint32_t tlli = 0;
if (!TLVP_PRESENT(tp, BSSGP_IE_TLLI) ||
!TLVP_PRESENT(tp, BSSGP_IE_LLC_FRAMES_DISCARDED) ||
!TLVP_PRESENT(tp, BSSGP_IE_BVCI) ||
!TLVP_PRESENT(tp, BSSGP_IE_NUM_OCT_AFF)) {
LOGP(DBSSGP, LOGL_ERROR, "BSSGP BVCI=%u Rx LLC DISCARDED "
"missing mandatory IE\n", ctx->bvci);
}
if (TLVP_PRESENT(tp, BSSGP_IE_TLLI))
tlli = ntohl(*(uint32_t *)TLVP_VAL(tp, BSSGP_IE_TLLI));
DEBUGP(DBSSGP, "BSSGP BVCI=%u TLLI=%08x Rx LLC DISCARDED\n",
ctx->bvci, tlli);
rate_ctr_inc(&ctx->ctrg->ctr[BSSGP_CTR_DISCARDED]);
/* FIXME: send NM_LLC_DISCARDED to NM */
return 0;
}
static int bssgp_rx_fc_bvc(struct msgb *msg, struct tlv_parsed *tp,
struct bssgp_bvc_ctx *bctx)
{
DEBUGP(DBSSGP, "BSSGP BVCI=%u Rx Flow Control BVC\n",
bctx->bvci);
if (!TLVP_PRESENT(tp, BSSGP_IE_TAG) ||
!TLVP_PRESENT(tp, BSSGP_IE_BVC_BUCKET_SIZE) ||
!TLVP_PRESENT(tp, BSSGP_IE_BUCKET_LEAK_RATE) ||
!TLVP_PRESENT(tp, BSSGP_IE_BMAX_DEFAULT_MS) ||
!TLVP_PRESENT(tp, BSSGP_IE_R_DEFAULT_MS)) {
LOGP(DBSSGP, LOGL_ERROR, "BSSGP BVCI=%u Rx FC BVC "
"missing mandatory IE\n", bctx->bvci);
return bssgp_tx_status(BSSGP_CAUSE_MISSING_MAND_IE, NULL, msg);
}
/* FIXME: actually implement flow control */
/* Send FLOW_CONTROL_BVC_ACK */
return bssgp_tx_fc_bvc_ack(msgb_nsei(msg), *TLVP_VAL(tp, BSSGP_IE_TAG),
msgb_bvci(msg));
}
/* Receive a BSSGP PDU from a BSS on a PTP BVCI */
static int gprs_bssgp_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;
int rc = 0;
/* 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);
return bssgp_tx_status(BSSGP_CAUSE_BVCI_BLOCKED, &bvci, msg);
}
switch (pdu_type) {
case BSSGP_PDUT_UL_UNITDATA:
/* some LLC data from the MS */
rc = bssgp_rx_ul_ud(msg, tp, bctx);
break;
case BSSGP_PDUT_RA_CAPABILITY:
/* BSS requests RA capability or IMSI */
DEBUGP(DBSSGP, "BSSGP BVCI=%u Rx RA CAPABILITY UPDATE\n",
bctx->bvci);
/* FIXME: send GMM_RA_CAPABILITY_UPDATE.ind to GMM */
/* FIXME: send RA_CAPA_UPDATE_ACK */
break;
case BSSGP_PDUT_RADIO_STATUS:
DEBUGP(DBSSGP, "BSSGP BVCI=%u Rx RADIO STATUS\n", bctx->bvci);
/* BSS informs us of some exception */
/* FIXME: send GMM_RADIO_STATUS.ind to GMM */
break;
case BSSGP_PDUT_FLOW_CONTROL_BVC:
/* BSS informs us of available bandwidth in Gb interface */
rc = bssgp_rx_fc_bvc(msg, tp, bctx);
break;
case BSSGP_PDUT_FLOW_CONTROL_MS:
/* BSS informs us of available bandwidth to one MS */
DEBUGP(DBSSGP, "BSSGP BVCI=%u Rx Flow Control MS\n",
bctx->bvci);
/* FIXME: actually implement flow control */
/* FIXME: Send FLOW_CONTROL_MS_ACK */
break;
case BSSGP_PDUT_STATUS:
/* Some exception has occurred */
/* FIXME: send NM_STATUS.ind to NM */
case BSSGP_PDUT_DOWNLOAD_BSS_PFC:
case BSSGP_PDUT_CREATE_BSS_PFC_ACK:
case BSSGP_PDUT_CREATE_BSS_PFC_NACK:
case BSSGP_PDUT_MODIFY_BSS_PFC:
case BSSGP_PDUT_DELETE_BSS_PFC_ACK:
DEBUGP(DBSSGP, "BSSGP BVCI=%u Rx PDU type 0x%02x not [yet] "
"implemented\n", bctx->bvci, pdu_type);
rc = bssgp_tx_status(BSSGP_CAUSE_PDU_INCOMP_FEAT, NULL, msg);
break;
/* those only exist in the SGSN -> BSS direction */
case BSSGP_PDUT_DL_UNITDATA:
case BSSGP_PDUT_PAGING_PS:
case BSSGP_PDUT_PAGING_CS:
case BSSGP_PDUT_RA_CAPA_UPDATE_ACK:
case BSSGP_PDUT_FLOW_CONTROL_BVC_ACK:
case BSSGP_PDUT_FLOW_CONTROL_MS_ACK:
DEBUGP(DBSSGP, "BSSGP BVCI=%u PDU type 0x%02x only exists "
"in DL\n", bctx->bvci, pdu_type);
bssgp_tx_status(BSSGP_CAUSE_PROTO_ERR_UNSPEC, NULL, msg);
rc = -EINVAL;
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 BSS on a SIGNALLING BVCI */
static int gprs_bssgp_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);
uint8_t pdu_type = bgph->pdu_type;
int rc = 0;
uint16_t ns_bvci = msgb_bvci(msg);
uint16_t bvci;
switch (bgph->pdu_type) {
case BSSGP_PDUT_SUSPEND:
/* MS wants to suspend */
rc = bssgp_rx_suspend(msg, tp, bctx);
break;
case BSSGP_PDUT_RESUME:
/* MS wants to resume */
rc = bssgp_rx_resume(msg, tp, bctx);
break;
case BSSGP_PDUT_FLUSH_LL_ACK:
/* BSS informs us it has performed LL FLUSH */
DEBUGP(DBSSGP, "BSSGP Rx BVCI=%u FLUSH LL ACK\n", bctx->bvci);
/* FIXME: send NM_FLUSH_LL.res to NM */
break;
case BSSGP_PDUT_LLC_DISCARD:
/* BSS informs that some LLC PDU's have been discarded */
rc = bssgp_rx_llc_disc(msg, tp, bctx);
break;
case BSSGP_PDUT_BVC_BLOCK:
/* BSS tells us that BVC shall be blocked */
if (!TLVP_PRESENT(tp, BSSGP_IE_BVCI) ||
!TLVP_PRESENT(tp, BSSGP_IE_CAUSE)) {
LOGP(DBSSGP, LOGL_ERROR, "BSSGP Rx BVC-BLOCK "
"missing mandatory IE\n");
goto err_mand_ie;
}
rc = bssgp_rx_bvc_block(msg, tp);
break;
case BSSGP_PDUT_BVC_UNBLOCK:
/* BSS tells us that BVC shall be unblocked */
if (!TLVP_PRESENT(tp, BSSGP_IE_BVCI)) {
LOGP(DBSSGP, LOGL_ERROR, "BSSGP Rx BVC-UNBLOCK "
"missing mandatory IE\n");
goto err_mand_ie;
}
rc = bssgp_rx_bvc_unblock(msg, tp);
break;
case BSSGP_PDUT_BVC_RESET:
/* BSS tells us that BVC init is required */
if (!TLVP_PRESENT(tp, BSSGP_IE_BVCI) ||
!TLVP_PRESENT(tp, BSSGP_IE_CAUSE)) {
LOGP(DBSSGP, LOGL_ERROR, "BSSGP Rx BVC-RESET "
"missing mandatory IE\n");
goto err_mand_ie;
}
rc = bssgp_rx_bvc_reset(msg, tp, ns_bvci);
break;
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;
/* those only exist in the SGSN -> BSS direction */
case BSSGP_PDUT_PAGING_PS:
case BSSGP_PDUT_PAGING_CS:
case BSSGP_PDUT_SUSPEND_ACK:
case BSSGP_PDUT_SUSPEND_NACK:
case BSSGP_PDUT_RESUME_ACK:
case BSSGP_PDUT_RESUME_NACK:
case BSSGP_PDUT_FLUSH_LL:
case BSSGP_PDUT_BVC_BLOCK_ACK:
case BSSGP_PDUT_BVC_UNBLOCK_ACK:
case BSSGP_PDUT_SGSN_INVOKE_TRACE:
DEBUGP(DBSSGP, "BSSGP BVCI=%u Rx PDU type 0x%02x only exists "
"in DL\n", bctx->bvci, pdu_type);
bssgp_tx_status(BSSGP_CAUSE_PROTO_ERR_UNSPEC, NULL, msg);
rc = -EINVAL;
break;
default:
DEBUGP(DBSSGP, "BSSGP BVCI=%u Rx PDU type 0x%02x unknown\n",
bctx->bvci, pdu_type);
rc = bssgp_tx_status(BSSGP_CAUSE_PROTO_ERR_UNSPEC, NULL, msg);
break;
}
return rc;
err_mand_ie:
return bssgp_tx_status(BSSGP_CAUSE_MISSING_MAND_IE, NULL, msg);
}
/* We expect msgb_bssgph() to point to the BSSGP header */
int gprs_bssgp_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;
struct bssgp_bvc_ctx *bctx;
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 && pdu_type != BSSGP_PDUT_BVC_RESET) {
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)
rc = gprs_bssgp_rx_sign(msg, &tp, bctx);
else if (ns_bvci == BVCI_PTM)
rc = bssgp_tx_status(BSSGP_CAUSE_PDU_INCOMP_FEAT, NULL, msg);
else
rc = gprs_bssgp_rx_ptp(msg, &tp, bctx);
return rc;
}
/* Entry function from upper level (LLC), asking us to transmit a BSSGP PDU
* to a remote MS (identified by TLLI) at a BTS identified by its BVCI and NSEI */
int gprs_bssgp_tx_dl_ud(struct msgb *msg, struct sgsn_mm_ctx *mmctx)
{
struct bssgp_bvc_ctx *bctx;
struct bssgp_ud_hdr *budh;
uint8_t llc_pdu_tlv_hdr_len = 2;
uint8_t *llc_pdu_tlv, *qos_profile;
uint16_t pdu_lifetime = 1000; /* centi-seconds */
uint8_t qos_profile_default[3] = { 0x00, 0x00, 0x20 };
uint16_t msg_len = msg->len;
uint16_t bvci = msgb_bvci(msg);
uint16_t nsei = msgb_nsei(msg);
uint16_t drx_params;
/* Identifiers from UP: TLLI, BVCI, NSEI (all in msgb->cb) */
if (bvci <= BVCI_PTM ) {
LOGP(DBSSGP, LOGL_ERROR, "Cannot send DL-UD to BVCI %u\n",
bvci);
return -EINVAL;
}
bctx = btsctx_by_bvci_nsei(bvci, nsei);
if (!bctx) {
/* FIXME: don't simply create missing context, but reject message */
bctx = btsctx_alloc(bvci, nsei);
}
if (msg->len > TVLV_MAX_ONEBYTE)
llc_pdu_tlv_hdr_len += 1;
/* prepend the tag and length of the LLC-PDU TLV */
llc_pdu_tlv = msgb_push(msg, llc_pdu_tlv_hdr_len);
llc_pdu_tlv[0] = BSSGP_IE_LLC_PDU;
if (llc_pdu_tlv_hdr_len > 2) {
llc_pdu_tlv[1] = msg_len >> 8;
llc_pdu_tlv[2] = msg_len & 0xff;
} else {
llc_pdu_tlv[1] = msg_len & 0x7f;
llc_pdu_tlv[1] |= 0x80;
}
/* FIXME: optional elements: Alignment, UTRAN CCO, LSA, PFI */
if (mmctx) {
/* Old TLLI to help BSS map from old->new */
#if 0
if (mmctx->tlli_old)
msgb_tvlv_push(msg, BSSGP_IE_TLLI, 4, htonl(*tlli_old));
#endif
/* IMSI */
if (strlen(mmctx->imsi)) {
uint8_t mi[10];
int imsi_len = gsm48_generate_mid_from_imsi(mi, mmctx->imsi);
if (imsi_len > 2)
msgb_tvlv_push(msg, BSSGP_IE_IMSI,
imsi_len-2, mi+2);
}
/* DRX parameters */
drx_params = htons(mmctx->drx_parms);
msgb_tvlv_push(msg, BSSGP_IE_DRX_PARAMS, 2,
(uint8_t *) &drx_params);
/* FIXME: Priority */
/* MS Radio Access Capability */
if (mmctx->ms_radio_access_capa.len)
msgb_tvlv_push(msg, BSSGP_IE_MS_RADIO_ACCESS_CAP,
mmctx->ms_radio_access_capa.len,
mmctx->ms_radio_access_capa.buf);
}
/* prepend the pdu lifetime */
pdu_lifetime = htons(pdu_lifetime);
msgb_tvlv_push(msg, BSSGP_IE_PDU_LIFETIME, 2, (uint8_t *)&pdu_lifetime);
/* prepend the QoS profile, TLLI and pdu type */
budh = (struct bssgp_ud_hdr *) msgb_push(msg, sizeof(*budh));
memcpy(budh->qos_profile, qos_profile_default, sizeof(qos_profile_default));
budh->tlli = htonl(msgb_tlli(msg));
budh->pdu_type = BSSGP_PDUT_DL_UNITDATA;
rate_ctr_inc(&bctx->ctrg->ctr[BSSGP_CTR_PKTS_OUT]);
rate_ctr_add(&bctx->ctrg->ctr[BSSGP_CTR_BYTES_OUT], msg->len);
/* Identifiers down: BVCI, NSEI (in msgb->cb) */
return gprs_ns_sendmsg(bssgp_nsi, msg);
}
/* Send a single GMM-PAGING.req to a given NSEI/NS-BVCI */
int gprs_bssgp_tx_paging(uint16_t nsei, uint16_t ns_bvci,
struct bssgp_paging_info *pinfo)
{
struct msgb *msg = bssgp_msgb_alloc();
struct bssgp_normal_hdr *bgph =
(struct bssgp_normal_hdr *) msgb_put(msg, sizeof(*bgph));
uint16_t drx_params = htons(pinfo->drx_params);
uint8_t mi[10];
int imsi_len = gsm48_generate_mid_from_imsi(mi, pinfo->imsi);
uint8_t ra[6];
if (imsi_len < 2)
return -EINVAL;
msgb_nsei(msg) = nsei;
msgb_bvci(msg) = ns_bvci;
if (pinfo->mode == BSSGP_PAGING_PS)
bgph->pdu_type = BSSGP_PDUT_PAGING_PS;
else
bgph->pdu_type = BSSGP_PDUT_PAGING_CS;
/* IMSI */
msgb_tvlv_put(msg, BSSGP_IE_IMSI, imsi_len-2, mi+2);
/* DRX Parameters */
msgb_tvlv_put(msg, BSSGP_IE_DRX_PARAMS, 2,
(uint8_t *) &drx_params);
/* Scope */
switch (pinfo->scope) {
case BSSGP_PAGING_BSS_AREA:
{
uint8_t null = 0;
msgb_tvlv_put(msg, BSSGP_IE_BSS_AREA_ID, 1, &null);
}
break;
case BSSGP_PAGING_LOCATION_AREA:
gsm48_construct_ra(ra, &pinfo->raid);
msgb_tvlv_put(msg, BSSGP_IE_LOCATION_AREA, 4, ra);
break;
case BSSGP_PAGING_ROUTEING_AREA:
gsm48_construct_ra(ra, &pinfo->raid);
msgb_tvlv_put(msg, BSSGP_IE_ROUTEING_AREA, 6, ra);
break;
case BSSGP_PAGING_BVCI:
{
uint16_t bvci = htons(pinfo->bvci);
msgb_tvlv_put(msg, BSSGP_IE_BVCI, 2, (uint8_t *)&bvci);
}
break;
}
/* QoS profile mandatory for PS */
if (pinfo->mode == BSSGP_PAGING_PS)
msgb_tvlv_put(msg, BSSGP_IE_QOS_PROFILE, 3, pinfo->qos);
/* Optional (P-)TMSI */
if (pinfo->ptmsi) {
uint32_t ptmsi = htonl(*pinfo->ptmsi);
msgb_tvlv_put(msg, BSSGP_IE_TMSI, 4, (uint8_t *) &ptmsi);
}
return gprs_ns_sendmsg(bssgp_nsi, msg);
}
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