/* NS-over-IP proxy */
/* (C) 2010-2020 by Harald Welte <laforge@gnumonks.org>
* (C) 2010-2013 by On-Waves
* (C) 2013 by Holger Hans Peter Freyther
* 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 <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <getopt.h>
#include <errno.h>
#include <sys/fcntl.h>
#include <sys/stat.h>
#include <arpa/inet.h>
#include <time.h>
#include <osmocom/core/hashtable.h>
#include <osmocom/core/logging.h>
#include <osmocom/core/linuxlist.h>
#include <osmocom/core/talloc.h>
#include <osmocom/core/select.h>
#include <osmocom/core/rate_ctr.h>
#include <osmocom/core/signal.h>
#include <osmocom/core/stats.h>
#include <osmocom/core/utils.h>
#include <osmocom/gprs/gprs_ns2.h>
#include <osmocom/gprs/gprs_bssgp.h>
#include <osmocom/gprs/gprs_bssgp2.h>
#include <osmocom/gprs/gprs_bssgp_bss.h>
#include <osmocom/gprs/bssgp_bvc_fsm.h>
#include <osmocom/gprs/protocol/gsm_08_18.h>
#include <osmocom/gsm/gsm23236.h>
#include <osmocom/gsm/gsm_utils.h>
#include "debug.h"
#include <osmocom/gbproxy/gb_proxy.h>
#include <osmocom/gsm/protocol/gsm_04_08_gprs.h>
extern void *tall_sgsn_ctx;
static const struct rate_ctr_desc global_ctr_description[] = {
[GBPROX_GLOB_CTR_INV_BVCI] = { "inv-bvci", "Invalid BVC Identifier " },
[GBPROX_GLOB_CTR_INV_LAI] = { "inv-lai", "Invalid Location Area Identifier" },
[GBPROX_GLOB_CTR_INV_RAI] = { "inv-rai", "Invalid Routing Area Identifier " },
[GBPROX_GLOB_CTR_INV_NSEI] = { "inv-nsei", "No BVC established for NSEI " },
[GBPROX_GLOB_CTR_PROTO_ERR_BSS] = { "proto-err:bss", "BSSGP protocol error (BSS )" },
[GBPROX_GLOB_CTR_PROTO_ERR_SGSN] = { "proto-err:sgsn", "BSSGP protocol error (SGSN)" },
[GBPROX_GLOB_CTR_NOT_SUPPORTED_BSS] = { "not-supp:bss", "Feature not supported (BSS )" },
[GBPROX_GLOB_CTR_NOT_SUPPORTED_SGSN] = { "not-supp:sgsn", "Feature not supported (SGSN)" },
[GBPROX_GLOB_CTR_RESTART_RESET_SGSN] = { "restart:sgsn", "Restarted RESET procedure (SGSN)" },
[GBPROX_GLOB_CTR_TX_ERR_SGSN] = { "tx-err:sgsn", "NS Transmission error (SGSN)" },
[GBPROX_GLOB_CTR_OTHER_ERR] = { "error", "Other error " },
};
static const struct rate_ctr_group_desc global_ctrg_desc = {
.group_name_prefix = "gbproxy:global",
.group_description = "GBProxy Global Statistics",
.num_ctr = ARRAY_SIZE(global_ctr_description),
.ctr_desc = global_ctr_description,
.class_id = OSMO_STATS_CLASS_GLOBAL,
};
int tx_status(struct gbproxy_nse *nse, uint16_t ns_bvci, enum gprs_bssgp_cause cause, const uint16_t *bvci, const struct msgb *old_msg)
{
int rc;
struct msgb *msg = bssgp2_enc_status(cause, bvci, old_msg, nse->max_sdu_len);
if (!msg) {
LOGPNSE(nse, LOGL_NOTICE, "Unable to encode STATUS message\n");
return -ENOMEM;
}
rc = bssgp2_nsi_tx_ptp(nse->cfg->nsi, nse->nsei, ns_bvci, msg, 0);
if (rc < 0)
LOGPNSE(nse, LOGL_NOTICE, "Unable to send STATUS message\n");
return rc;
}
/* generate BVC-STATUS mess
age with cause value derived from TLV-parser error */
static int tx_status_from_tlvp(struct gbproxy_nse *nse, enum osmo_tlv_parser_error tlv_p_err, struct msgb *orig_msg)
{
uint8_t bssgp_cause;
switch (tlv_p_err) {
case OSMO_TLVP_ERR_MAND_IE_MISSING:
bssgp_cause = BSSGP_CAUSE_MISSING_MAND_IE;
break;
default:
bssgp_cause = BSSGP_CAUSE_PROTO_ERR_UNSPEC;
}
return tx_status(nse, msgb_bvci(orig_msg), bssgp_cause, NULL, orig_msg);
}
/* strip off the NS header */
static void strip_ns_hdr(struct msgb *msg)
{
int strip_len = msgb_bssgph(msg) - msg->data;
msgb_pull(msg, strip_len);
}
#if 0
/* feed a message down the NS-VC associated with the specified bvc */
static int gbprox_relay2sgsn(struct gbproxy_config *cfg, struct msgb *old_msg,
uint16_t ns_bvci, uint16_t sgsn_nsei)
{
/* create a copy of the message so the old one can
* be free()d safely when we return from gbprox_rcvmsg() */
struct gprs_ns2_inst *nsi = cfg->nsi;
struct osmo_gprs_ns2_prim nsp = {};
struct msgb *msg = bssgp_msgb_copy(old_msg, "msgb_relay2sgsn");
int rc;
DEBUGP(DGPRS, "NSE(%05u/BSS)-BVC(%05u) proxying BTS->SGSN NSE(%05u/SGSN)\n",
msgb_nsei(msg), ns_bvci, sgsn_nsei);
nsp.bvci = ns_bvci;
nsp.nsei = sgsn_nsei;
strip_ns_hdr(msg);
osmo_prim_init(&nsp.oph, SAP_NS, PRIM_NS_UNIT_DATA,
PRIM_OP_REQUEST, msg);
rc = gprs_ns2_recv_prim(nsi, &nsp.oph);
if (rc < 0)
rate_ctr_inc(rate_ctr_group_get_ctr(cfg->ctrg, GBPROX_GLOB_CTR_TX_ERR_SGSN));
return rc;
}
#endif
/*! Determine the TLLI from the given BSSGP message.
* \param[in] bssgp pointer to start of BSSGP header
* \param[in] bssgp_len length of BSSGP message in octets
* \param[out] tlli TLLI (if any) in host byte order
* \returns 1 if TLLI found; 0 if none found; negative on parse error */
int gprs_gb_parse_tlli(const uint8_t *bssgp, size_t bssgp_len, uint32_t *tlli)
{
const struct bssgp_normal_hdr *bgph;
uint8_t pdu_type;
if (bssgp_len < sizeof(struct bssgp_normal_hdr))
return -EINVAL;
bgph = (struct bssgp_normal_hdr *)bssgp;
pdu_type = bgph->pdu_type;
if (pdu_type == BSSGP_PDUT_UL_UNITDATA ||
pdu_type == BSSGP_PDUT_DL_UNITDATA) {
const struct bssgp_ud_hdr *budh = (struct bssgp_ud_hdr *)bssgp;
if (bssgp_len < sizeof(struct bssgp_ud_hdr))
return -EINVAL;
*tlli = osmo_load32be((const uint8_t *)&budh->tlli);
return 1;
} else {
const uint8_t *data = bgph->data;
size_t data_len = bssgp_len - sizeof(*bgph);
struct tlv_parsed tp;
if (bssgp_tlv_parse(&tp, data, data_len) < 0)
return -EINVAL;
if (TLVP_PRESENT(&tp, BSSGP_IE_TLLI)) {
*tlli = osmo_load32be(TLVP_VAL(&tp, BSSGP_IE_TLLI));
return 1;
}
}
/* No TLLI present in message */
return 0;
}
/* feed a message down the NSE */
static int gbprox_relay2nse(struct msgb *old_msg, struct gbproxy_nse *nse,
uint16_t ns_bvci)
{
OSMO_ASSERT(nse);
OSMO_ASSERT(nse->cfg);
/* create a copy of the message so the old one can
* be free()d safely when we return from gbprox_rcvmsg() */
struct gprs_ns2_inst *nsi = nse->cfg->nsi;
struct msgb *msg = bssgp_msgb_copy(old_msg, "msgb_relay2nse");
uint32_t tlli = 0;
int rc;
DEBUGP(DGPRS, "NSE(%05u/%s)-BVC(%05u/??) proxying to NSE(%05u/%s)\n", msgb_nsei(msg),
!nse->sgsn_facing ? "SGSN" : "BSS", ns_bvci, nse->nsei, nse->sgsn_facing ? "SGSN" : "BSS");
/* Strip the old NS header, it will be replaced with a new one */
strip_ns_hdr(msg);
/* TS 48.018 Section 5.4.2: The link selector parameter is
* defined in 3GPP TS 48.016. At one side of the Gb interface,
* all BSSGP UNITDATA PDUs related to an MS shall be passed with
* the same LSP, e.g. the LSP contains the MS's TLLI, to the
* underlying network service. */
gprs_gb_parse_tlli(msgb_data(msg), msgb_length(msg), &tlli);
rc = bssgp2_nsi_tx_ptp(nsi, nse->nsei, ns_bvci, msg, tlli);
/* FIXME: We need a counter group for gbproxy_nse */
//if (rc < 0)
// rate_ctr_inc(rate_ctr_group_get_ctr(bvc->ctrg, GBPROX_PEER_CTR_TX_ERR));
return rc;
}
/* feed a message down the NS-VC associated with the specified bvc */
static int gbprox_relay2peer(struct msgb *old_msg, struct gbproxy_bvc *bvc,
uint16_t ns_bvci)
{
int rc;
struct gbproxy_nse *nse = bvc->nse;
OSMO_ASSERT(nse);
rc = gbprox_relay2nse(old_msg, nse, ns_bvci);
if (rc < 0)
rate_ctr_inc(rate_ctr_group_get_ctr(bvc->ctrg, GBPROX_PEER_CTR_TX_ERR));
return rc;
}
int bssgp_prim_cb(struct osmo_prim_hdr *oph, void *ctx)
{
return 0;
}
/***********************************************************************
* PTP BVC handling
***********************************************************************/
/* FIXME: Handle the tlli NULL case correctly,
* This function should take a generic selector
* and choose an sgsn based on that
*/
static struct gbproxy_sgsn *gbproxy_select_sgsn(struct gbproxy_config *cfg, const uint32_t *tlli)
{
struct gbproxy_sgsn *sgsn = NULL;
struct gbproxy_sgsn *sgsn_avoid = NULL;
int tlli_type;
int16_t nri;
bool null_nri = false;
if (!tlli) {
sgsn = gbproxy_sgsn_by_available(cfg);
if (!sgsn) {
LOGP(DGPRS, LOGL_ERROR, "Could not find any available SGSN\n");
return NULL;
}
LOGPSGSN(sgsn, LOGL_INFO, "Could not get TLLI, using first available SGSN\n");
return sgsn;
}
if (cfg->pool.nri_bitlen == 0) {
/* Pooling is disabled */
sgsn = gbproxy_sgsn_by_available(cfg);
if (!sgsn) {
LOGP(DGPRS, LOGL_ERROR, "Could not find any available SGSN\n");
return NULL;
}
LOGPSGSN(sgsn, LOGL_DEBUG, "Pooling disabled, using first available SGSN\n");
} else {
/* Pooling is enabled, try to use the NRI for routing to an SGSN
* See 3GPP TS 23.236 Ch. 5.3.2 */
tlli_type = gprs_tlli_type(*tlli);
if (tlli_type == TLLI_LOCAL || tlli_type == TLLI_FOREIGN) {
/* Only get/use the NRI if tlli type is local */
osmo_tmsi_nri_v_get(&nri, *tlli, cfg->pool.nri_bitlen);
if (nri >= 0) {
/* Get the SGSN for the NRI */
sgsn = gbproxy_sgsn_by_nri(cfg, nri, &null_nri);
if (sgsn && !null_nri)
return sgsn;
/* If the NRI is the null NRI, we need to avoid the chosen SGSN */
if (null_nri && sgsn) {
sgsn_avoid = sgsn;
}
} else {
/* We couldn't get the NRI from the TLLI */
LOGP(DGPRS, LOGL_ERROR, "Could not extract NRI from local TLLI %08x\n", *tlli);
}
} else {
LOGP(DGPRS, LOGL_INFO, "TLLI %08x is neither local nor foreign, not routing by NRI\n", *tlli);
}
}
/* If we haven't found an SGSN yet we need to choose one, but avoid the one in sgsn_avoid
* NOTE: This function is not stable if the number of SGSNs or allow_attach changes
* We could implement TLLI tracking here, but 3GPP TS 23.236 Ch. 5.3.2 (see NOTE) argues that
* we can just wait for the MS to reattempt the procedure.
*/
if (!sgsn)
sgsn = gbproxy_sgsn_by_tlli(cfg, sgsn_avoid, *tlli);
if (!sgsn) {
LOGP(DGPRS, LOGL_ERROR, "No suitable SGSN found for TLLI %u\n", *tlli);
return NULL;
}
return sgsn;
}
/*! Find the correct gbproxy_bvc given a cell and an SGSN
* \param[in] cfg The gbproxy configuration
* \param[in] cell The cell the message belongs to
* \param[in] tlli An optional TLLI used for tracking
* \return Returns 0 on success, otherwise a negative value
*/
static struct gbproxy_bvc *gbproxy_select_sgsn_bvc(struct gbproxy_config *cfg, struct gbproxy_cell *cell, const uint32_t *tlli)
{
struct gbproxy_sgsn *sgsn;
struct gbproxy_bvc *sgsn_bvc = NULL;
int i;
sgsn = gbproxy_select_sgsn(cfg, tlli);
if (!sgsn) {
LOGPCELL(cell, LOGL_ERROR, "Could not find any SGSN, dropping message!\n");
return NULL;
}
/* Get the BVC for this SGSN/NSE */
for (i = 0; i < ARRAY_SIZE(cell->sgsn_bvc); i++) {
sgsn_bvc = cell->sgsn_bvc[i];
if (!sgsn_bvc)
continue;
if (sgsn->nse != sgsn_bvc->nse)
continue;
if (!bssgp_bvc_fsm_is_unblocked(sgsn_bvc->fi))
continue;
return sgsn_bvc;
}
/* This shouldn't happen */
LOGPCELL(cell, LOGL_ERROR, "Could not find matching BVC for SGSN %s, dropping message!\n", sgsn->name);
return NULL;
}
/*! Send a message to the next SGSN, possibly ignoring the null SGSN
* route an uplink message on a PTP-BVC to a SGSN using the TLLI
* \param[in] cell The cell the message belongs to
* \param[in] msg The BSSGP message
* \param[in] null_sgsn If not NULL then avoid this SGSN (because this message contains its null NRI)
* \param[in] tlli An optional TLLI used for tracking
* \return Returns 0 on success, otherwise a negative value
*/
static int gbprox_bss2sgsn_tlli(struct gbproxy_cell *cell, struct msgb *msg, const uint32_t *tlli,
bool sig_bvci)
{
struct gbproxy_config *cfg = cell->cfg;
struct gbproxy_bvc *sgsn_bvc;
sgsn_bvc = gbproxy_select_sgsn_bvc(cfg, cell, tlli);
if (!sgsn_bvc) {
LOGPCELL(cell, LOGL_NOTICE, "Could not find any SGSN for TLLI %u, dropping message!\n", *tlli);
return -EINVAL;
}
return gbprox_relay2peer(msg, sgsn_bvc, sig_bvci ? 0 : sgsn_bvc->bvci);
}
static int gbproxy_decode_bssgp(const struct bssgp_normal_hdr *bgph, int msg_len, struct tlv_parsed *tp, const char *log_pfx)
{
int rc;
/* UNITDATA PDUs have a different header than the other PDUs */
if (bgph->pdu_type == BSSGP_PDUT_UL_UNITDATA || bgph->pdu_type == BSSGP_PDUT_DL_UNITDATA) {
const struct bssgp_ud_hdr *budh = (struct bssgp_ud_hdr *) bgph;
if (msg_len < sizeof(*budh))
return OSMO_TLVP_ERR_MAND_IE_MISSING;
rc = osmo_tlv_prot_parse(&osmo_pdef_bssgp, tp, 1, budh->pdu_type, budh->data,
msg_len - sizeof(*budh), 0, 0, DGPRS, log_pfx);
/* populate TLLI from the fixed headser into the TLV-parsed array so later code
* doesn't have to worry where the TLLI came from */
tp->lv[BSSGP_IE_TLLI].len = 4;
tp->lv[BSSGP_IE_TLLI].val = (const uint8_t *) &budh->tlli;
} else {
rc = osmo_tlv_prot_parse(&osmo_pdef_bssgp, tp, 1, bgph->pdu_type, bgph->data,
msg_len - sizeof(*bgph), 0, 0, DGPRS, log_pfx);
}
return rc;
}
static int gbproxy_tlli_from_status_pdu(struct tlv_parsed *tp, uint32_t *tlli, char *log_pfx);
/* Receive an incoming PTP message from a BSS-side NS-VC */
static int gbprox_rx_ptp_from_bss(struct gbproxy_nse *nse, struct msgb *msg, uint16_t ns_bvci)
{
struct bssgp_normal_hdr *bgph = (struct bssgp_normal_hdr *) msgb_bssgph(msg);
const char *pdut_name = osmo_tlv_prot_msg_name(&osmo_pdef_bssgp, bgph->pdu_type);
struct gbproxy_bvc *bss_bvc;
struct tlv_parsed tp;
char log_pfx[32];
uint32_t tlli;
int rc;
snprintf(log_pfx, sizeof(log_pfx), "NSE(%05u/BSS)-BVC(%05u/??)", nse->nsei, ns_bvci);
LOGP(DGPRS, LOGL_DEBUG, "%s Rx %s\n", log_pfx, pdut_name);
if (ns_bvci == 0 || ns_bvci == 1) {
LOGP(DGPRS, LOGL_NOTICE, "%s BVCI=%05u is not PTP\n", log_pfx, ns_bvci);
return tx_status(nse, ns_bvci, BSSGP_CAUSE_PROTO_ERR_UNSPEC, NULL, msg);
}
if (!(bssgp_pdu_type_flags(bgph->pdu_type) & BSSGP_PDUF_PTP)) {
LOGP(DGPRS, LOGL_NOTICE, "%s %s not allowed in PTP BVC\n", log_pfx, pdut_name);
return tx_status(nse, ns_bvci, BSSGP_CAUSE_PROTO_ERR_UNSPEC, NULL, msg);
}
if (!(bssgp_pdu_type_flags(bgph->pdu_type) & BSSGP_PDUF_UL)) {
LOGP(DGPRS, LOGL_NOTICE, "%s %s not allowed in uplink direction\n", log_pfx, pdut_name);
return tx_status(nse, ns_bvci, BSSGP_CAUSE_PROTO_ERR_UNSPEC, NULL, msg);
}
bss_bvc = gbproxy_bvc_by_bvci(nse, ns_bvci);
if (!bss_bvc) {
LOGP(DGPRS, LOGL_NOTICE, "%s %s - Didn't find BVC for PTP message, discarding\n",
log_pfx, pdut_name);
return tx_status(nse, ns_bvci, BSSGP_CAUSE_UNKNOWN_BVCI, &ns_bvci, msg);
}
rc = gbproxy_decode_bssgp(bgph, msgb_bssgp_len(msg), &tp, log_pfx);
if (rc < 0) {
rate_ctr_inc(rate_ctr_group_get_ctr(nse->cfg->ctrg, GBPROX_GLOB_CTR_PROTO_ERR_BSS));
return tx_status_from_tlvp(nse, rc, msg);
}
/* hack to get both msg + tlv_parsed passed via osmo_fsm_inst_dispatch */
msgb_bcid(msg) = (void *)&tp;
switch (bgph->pdu_type) {
case BSSGP_PDUT_UL_UNITDATA:
case BSSGP_PDUT_RA_CAPA_UPDATE:
case BSSGP_PDUT_FLOW_CONTROL_MS:
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_ACK:
case BSSGP_PDUT_DELETE_BSS_PFC_ACK:
case BSSGP_PDUT_FLOW_CONTROL_PFC:
case BSSGP_PDUT_DELETE_BSS_PFC_REQ:
case BSSGP_PDUT_PS_HO_REQUIRED:
case BSSGP_PDUT_PS_HO_REQUEST_ACK:
case BSSGP_PDUT_PS_HO_REQUEST_NACK:
case BSSGP_PDUT_PS_HO_COMPLETE:
case BSSGP_PDUT_PS_HO_CANCEL:
/* We can route based on TLLI-NRI */
tlli = osmo_load32be(TLVP_VAL(&tp, BSSGP_IE_TLLI));
rc = gbprox_bss2sgsn_tlli(bss_bvc->cell, msg, &tlli, false);
break;
case BSSGP_PDUT_RADIO_STATUS:
if (TLVP_PRESENT(&tp, BSSGP_IE_TLLI)) {
tlli = osmo_load32be(TLVP_VAL(&tp, BSSGP_IE_TLLI));
rc = gbprox_bss2sgsn_tlli(bss_bvc->cell, msg, &tlli, false);
} else if (TLVP_PRESENT(&tp, BSSGP_IE_TMSI)) {
/* we treat the TMSI like a TLLI and extract the NRI from it */
tlli = osmo_load32be(TLVP_VAL(&tp, BSSGP_IE_TMSI));
/* Convert the TMSI into a FOREIGN TLLI so it is routed appropriately */
tlli = gprs_tmsi2tlli(tlli, TLLI_FOREIGN);
rc = gbprox_bss2sgsn_tlli(bss_bvc->cell, msg, &tlli, false);
} else if (TLVP_PRESENT(&tp, BSSGP_IE_IMSI)) {
/* FIXME: Use the IMSI as selector? */
rc = gbprox_bss2sgsn_tlli(bss_bvc->cell, msg, NULL, false);
} else
LOGPBVC(bss_bvc, LOGL_ERROR, "Rx RADIO-STATUS without any of the conditional IEs\n");
break;
case BSSGP_PDUT_DUMMY_PAGING_PS_RESP:
case BSSGP_PDUT_PAGING_PS_REJECT:
{
/* Route according to IMSI<->NSE cache entry */
struct osmo_mobile_identity mi;
const uint8_t *mi_data = TLVP_VAL(&tp, BSSGP_IE_IMSI);
uint8_t mi_len = TLVP_LEN(&tp, BSSGP_IE_IMSI);
osmo_mobile_identity_decode(&mi, mi_data, mi_len, false);
nse = gbproxy_nse_by_imsi(nse->cfg, mi.imsi, CACHE_USAGE_PAGING);
if (nse) {
OSMO_ASSERT(nse->sgsn_facing);
rc = gbprox_relay2nse(msg, nse, ns_bvci);
} else {
LOGPBVC(bss_bvc, LOGL_ERROR, "Rx unmatched %s with IMSI %s\n", pdut_name, mi.imsi);
}
break;
}
case BSSGP_PDUT_FLOW_CONTROL_BVC:
osmo_fsm_inst_dispatch(bss_bvc->fi, BSSGP_BVCFSM_E_RX_FC_BVC, msg);
break;
case BSSGP_PDUT_STATUS:
{
struct gbproxy_sgsn *sgsn;
/* Check if the status needs to be terminated locally */
uint8_t cause = *TLVP_VAL(&tp, BSSGP_IE_CAUSE);
LOGPNSE(nse, LOGL_NOTICE, "Rx STATUS cause=0x%02x(%s)\n", cause,
bssgp_cause_str(cause));
if (gbproxy_tlli_from_status_pdu(&tp, &tlli, log_pfx) == 0)
sgsn = gbproxy_select_sgsn(nse->cfg, &tlli);
else
sgsn = gbproxy_select_sgsn(nse->cfg, NULL);
if (!sgsn) {
rc = -EINVAL;
break;
}
rc = gbprox_relay2nse(msg, sgsn->nse, ns_bvci);
break;
}
}
if (rc < 0)
rate_ctr_inc(rate_ctr_group_get_ctr(bss_bvc->ctrg, GBPROX_PEER_CTR_FWD_FROM_BSS_ERR));
/* avoid a dangling pointer from heap to stack (see above "hack" to set it to &tp) */
msgb_bcid(msg) = 0;
return 0;
}
/* Receive an incoming PTP message from a SGSN-side NS-VC */
static int gbprox_rx_ptp_from_sgsn(struct gbproxy_nse *nse, struct msgb *msg, uint16_t ns_bvci)
{
struct bssgp_normal_hdr *bgph = (struct bssgp_normal_hdr *) msgb_bssgph(msg);
const char *pdut_name = osmo_tlv_prot_msg_name(&osmo_pdef_bssgp, bgph->pdu_type);
struct gbproxy_bvc *sgsn_bvc, *bss_bvc;
struct tlv_parsed tp;
char log_pfx[32];
int rc;
snprintf(log_pfx, sizeof(log_pfx), "NSE(%05u/SGSN)-BVC(%05u/??)", nse->nsei, ns_bvci);
LOGP(DGPRS, LOGL_DEBUG, "%s Rx %s\n", log_pfx, pdut_name);
if (ns_bvci == 0 || ns_bvci == 1) {
LOGP(DGPRS, LOGL_NOTICE, "%s BVCI is not PTP\n", log_pfx);
return tx_status(nse, ns_bvci, BSSGP_CAUSE_PROTO_ERR_UNSPEC, NULL, msg);
}
if (!(bssgp_pdu_type_flags(bgph->pdu_type) & BSSGP_PDUF_PTP)) {
LOGP(DGPRS, LOGL_NOTICE, "%s %s not allowed in PTP BVC\n", log_pfx, pdut_name);
return tx_status(nse, ns_bvci, BSSGP_CAUSE_PROTO_ERR_UNSPEC, NULL, msg);
}
if (!(bssgp_pdu_type_flags(bgph->pdu_type) & BSSGP_PDUF_DL)) {
LOGP(DGPRS, LOGL_NOTICE, "%s %s not allowed in downlink direction\n", log_pfx, pdut_name);
return tx_status(nse, ns_bvci, BSSGP_CAUSE_PROTO_ERR_UNSPEC, NULL, msg);
}
sgsn_bvc = gbproxy_bvc_by_bvci(nse, ns_bvci);
if (!sgsn_bvc) {
LOGP(DGPRS, LOGL_NOTICE, "%s %s - Didn't find BVC for for PTP message, discarding\n",
log_pfx, pdut_name);
rate_ctr_inc(rate_ctr_group_get_ctr(nse->cfg->ctrg, GBPROX_GLOB_CTR_INV_BVCI));
return tx_status(nse, ns_bvci, BSSGP_CAUSE_UNKNOWN_BVCI, &ns_bvci, msg);
}
if (!bssgp_bvc_fsm_is_unblocked(sgsn_bvc->fi)) {
LOGPBVC(sgsn_bvc, LOGL_NOTICE, "Rx %s: Dropping on blocked BVC\n", pdut_name);
rate_ctr_inc(rate_ctr_group_get_ctr(sgsn_bvc->ctrg, GBPROX_PEER_CTR_DROPPED));
return tx_status(nse, ns_bvci, BSSGP_CAUSE_BVCI_BLOCKED, &ns_bvci, msg);
}
rc = gbproxy_decode_bssgp(bgph, msgb_bssgp_len(msg), &tp, log_pfx);
if (rc < 0) {
rate_ctr_inc(rate_ctr_group_get_ctr(nse->cfg->ctrg, GBPROX_GLOB_CTR_PROTO_ERR_SGSN));
return tx_status_from_tlvp(nse, rc, msg);
}
/* hack to get both msg + tlv_parsed passed via osmo_fsm_inst_dispatch */
msgb_bcid(msg) = (void *)&tp;
OSMO_ASSERT(sgsn_bvc->cell);
bss_bvc = sgsn_bvc->cell->bss_bvc;
switch (bgph->pdu_type) {
case BSSGP_PDUT_FLOW_CONTROL_BVC_ACK:
return osmo_fsm_inst_dispatch(sgsn_bvc->fi, BSSGP_BVCFSM_E_RX_FC_BVC_ACK, msg);
case BSSGP_PDUT_DUMMY_PAGING_PS:
case BSSGP_PDUT_PAGING_PS:
{
/* Cache the IMSI<->NSE to route PAGING REJECT */
struct osmo_mobile_identity mi;
const uint8_t *mi_data = TLVP_VAL(&tp, BSSGP_IE_IMSI);
uint8_t mi_len = TLVP_LEN(&tp, BSSGP_IE_IMSI);
osmo_mobile_identity_decode(&mi, mi_data, mi_len, false);
gbproxy_imsi_cache_update(nse, mi.imsi, CACHE_USAGE_PAGING);
break;
}
default:
break;
}
rc = gbprox_relay2peer(msg, bss_bvc, bss_bvc->bvci);
if (rc < 0)
rate_ctr_inc(rate_ctr_group_get_ctr(bss_bvc->ctrg, GBPROX_PEER_CTR_FWD_FROM_SGSN_ERR));
return rc;
}
/***********************************************************************
* BVC FSM call-backs
***********************************************************************/
/* helper function to dispatch a FSM event to all SGSN-side BVC FSMs of a cell */
static void dispatch_to_all_sgsn_bvc(struct gbproxy_cell *cell, uint32_t event, void *priv)
{
unsigned int i;
for (i = 0; i < ARRAY_SIZE(cell->sgsn_bvc); i++) {
struct gbproxy_bvc *sgsn_bvc = cell->sgsn_bvc[i];
if (!sgsn_bvc)
continue;
osmo_fsm_inst_dispatch(sgsn_bvc->fi, event, priv);
}
}
/* BVC FSM informs us about a BSS-side reset of the signaling BVC */
static void bss_sig_bvc_reset_notif(uint16_t nsei, uint16_t bvci, const struct gprs_ra_id *ra_id,
uint16_t cell_id, uint8_t cause, void *priv)
{
struct gbproxy_bvc *sig_bvc = priv;
struct gbproxy_nse *nse = sig_bvc->nse;
struct gbproxy_bvc *ptp_bvc;
unsigned int i;
/* BLOCK all SGSN-side PTP BVC within this NSE */
hash_for_each(nse->bvcs, i, ptp_bvc, list) {
if (ptp_bvc == sig_bvc)
continue;
OSMO_ASSERT(ptp_bvc->cell);
dispatch_to_all_sgsn_bvc(ptp_bvc->cell, BSSGP_BVCFSM_E_REQ_BLOCK, &cause);
}
/* Delete all BSS-side PTP BVC within this NSE */
gbproxy_cleanup_bvcs(nse, 0);
/* TODO: we keep the "CELL" around for now, re-connecting it to
* any (later) new PTP-BVC for that BVCI. Not sure if that's the
* best idea ? */
}
/* forward declaration */
static const struct bssgp_bvc_fsm_ops sgsn_ptp_bvc_fsm_ops;
static const struct bssgp_bvc_fsm_ops bss_sig_bvc_fsm_ops = {
.reset_notification = bss_sig_bvc_reset_notif,
};
/* BVC FSM informs us about a BSS-side reset of a PTP BVC */
static void bss_ptp_bvc_reset_notif(uint16_t nsei, uint16_t bvci, const struct gprs_ra_id *ra_id,
uint16_t cell_id, uint8_t cause, void *priv)
{
struct gbproxy_bvc *bvc = priv;
struct gbproxy_config *cfg = bvc->nse->cfg;
struct gbproxy_nse *sgsn_nse;
unsigned int i;
OSMO_ASSERT(bvci != 0);
if (!bvc->cell) {
/* see if we have a CELL dangling around */
bvc->cell = gbproxy_cell_by_bvci(cfg, bvci);
if (bvc->cell) {
/* the CELL already exists. This means either it * was created before at an
* earlier PTP BVC-RESET, or that there are non-unique BVCIs and hence a
* malconfiguration */
if (bvc->cell->bss_bvc) {
LOGPBVC(bvc, LOGL_NOTICE, "Rx BVC-RESET via this NSE, but CELL already "
"has BVC on NSEI=%05u\n", bvc->cell->bss_bvc->nse->nsei);
LOGPBVC(bvc->cell->bss_bvc, LOGL_NOTICE, "Destroying due to conflicting "
"BVCI configuration (new NSEI=%05u)!\n", bvc->nse->nsei);
gbproxy_bvc_free(bvc->cell->bss_bvc);
bvc->cell = NULL;
} else {
LOGPBVC(bvc, LOGL_ERROR, "Found cell without BSS BVC, this should not happen!");
}
}
}
if (!bvc->cell) {
/* if we end up here, it means this is the first time we received a BVC-RESET
* for this BVC. We need to create the 'cell' data structure and the SGSN-side
* BVC counterparts */
bvc->cell = gbproxy_cell_alloc(cfg, bvci, ra_id, cell_id);
OSMO_ASSERT(bvc->cell);
/* link us to the cell and vice-versa */
bvc->cell->bss_bvc = bvc;
}
/* Ensure we have the correct RA/CELL ID */
if (!gsm48_ra_equal(&bvc->cell->id.raid, ra_id)) {
LOGPBVC(bvc, LOGL_NOTICE, "RAID changed from %s to %s, updating cell\n", osmo_rai_name(&bvc->cell->id.raid), osmo_rai_name(ra_id));
memcpy(&bvc->cell->id.raid, ra_id, sizeof(*ra_id));
}
if (bvc->cell->id.cid != cell_id) {
LOGPBVC(bvc, LOGL_NOTICE, "CellID changed from %05d to %05d, updating cell\n", bvc->cell->id.cid, cell_id);
bvc->cell->id.cid = cell_id;
}
/* Reallocate SGSN-side BVCs of the cell, and reset them
* Removing and reallocating is needed because the ra_id/cell_id might have changed */
hash_for_each(cfg->sgsn_nses, i, sgsn_nse, list) {
struct gbproxy_bvc *sgsn_bvc = gbproxy_bvc_by_bvci(sgsn_nse, bvci);
if (!sgsn_bvc)
sgsn_bvc = gbproxy_bvc_by_bvci_inactive(sgsn_nse, bvci);
if (sgsn_bvc)
gbproxy_bvc_free(sgsn_bvc);
sgsn_bvc = gbproxy_bvc_alloc(sgsn_nse, bvci);
OSMO_ASSERT(sgsn_bvc);
sgsn_bvc->cell = bvc->cell;
sgsn_bvc->fi = bssgp_bvc_fsm_alloc_ptp_bss(sgsn_bvc, cfg->nsi, sgsn_nse->nsei,
bvci, ra_id, cell_id);
OSMO_ASSERT(sgsn_bvc->fi);
bssgp_bvc_fsm_set_max_pdu_len(sgsn_bvc->fi, sgsn_nse->max_sdu_len);
bssgp_bvc_fsm_set_ops(sgsn_bvc->fi, &sgsn_ptp_bvc_fsm_ops, sgsn_bvc);
gbproxy_cell_add_sgsn_bvc(bvc->cell, sgsn_bvc);
}
/* Trigger outbound BVC-RESET procedure toward each SGSN */
dispatch_to_all_sgsn_bvc(bvc->cell, BSSGP_BVCFSM_E_REQ_RESET, &cause);
}
/* BVC FSM informs us about a BSS-side FSM state change */
static void bss_ptp_bvc_state_chg_notif(uint16_t nsei, uint16_t bvci, int old_state, int state, void *priv)
{
struct gbproxy_bvc *bvc = priv;
struct gbproxy_cell *cell = bvc->cell;
uint8_t cause = bssgp_bvc_fsm_get_block_cause(bvc->fi);
/* we have just been created but due to callback ordering the cell is not associated */
if (!cell)
return;
switch (state) {
case BSSGP_BVCFSM_S_BLOCKED:
/* block the corresponding SGSN-side PTP BVCs */
dispatch_to_all_sgsn_bvc(cell, BSSGP_BVCFSM_E_REQ_BLOCK, &cause);
break;
case BSSGP_BVCFSM_S_UNBLOCKED:
/* unblock the corresponding SGSN-side PTP BVCs */
dispatch_to_all_sgsn_bvc(cell, BSSGP_BVCFSM_E_REQ_UNBLOCK, NULL);
break;
}
}
/* BVC FSM informs us about BVC-FC PDU receive */
static void bss_ptp_bvc_fc_bvc(uint16_t nsei, uint16_t bvci, const struct bssgp2_flow_ctrl *fc, void *priv)
{
struct bssgp2_flow_ctrl fc_reduced;
struct gbproxy_bvc *bss_bvc = priv;
struct gbproxy_cell *cell;
struct gbproxy_config *cfg;
OSMO_ASSERT(bss_bvc);
OSMO_ASSERT(fc);
cell = bss_bvc->cell;
if (!cell)
return;
cfg = cell->cfg;
/* reduce / scale according to configuration to make sure we only advertise a fraction
* of the capacity to each of the SGSNs in the pool */
fc_reduced = *fc;
fc_reduced.bucket_size_max = (fc->bucket_size_max * cfg->pool.bvc_fc_ratio) / 100;
fc_reduced.bucket_leak_rate = (fc->bucket_leak_rate * cfg->pool.bvc_fc_ratio) / 100;
/* we don't modify the per-MS related values as any single MS is only served by one SGSN */
dispatch_to_all_sgsn_bvc(cell, BSSGP_BVCFSM_E_REQ_FC_BVC, (void *) &fc_reduced);
}
static const struct bssgp_bvc_fsm_ops bss_ptp_bvc_fsm_ops = {
.reset_notification = bss_ptp_bvc_reset_notif,
.state_chg_notification = bss_ptp_bvc_state_chg_notif,
.rx_fc_bvc = bss_ptp_bvc_fc_bvc,
};
/* BVC FSM informs us about a SGSN-side reset of a PTP BVC */
static void sgsn_ptp_bvc_reset_notif(uint16_t nsei, uint16_t bvci, const struct gprs_ra_id *ra_id,
uint16_t cell_id, uint8_t cause, void *priv)
{
struct gbproxy_bvc *bvc = priv;
if (!bvc->cell) {
LOGPBVC(bvc, LOGL_ERROR, "RESET of PTP BVC on SGSN side for which we have no BSS?\n");
return;
}
OSMO_ASSERT(bvc->cell->bss_bvc);
/* request reset of BSS-facing PTP-BVC */
osmo_fsm_inst_dispatch(bvc->cell->bss_bvc->fi, BSSGP_BVCFSM_E_REQ_RESET, &cause);
}
static const struct bssgp_bvc_fsm_ops sgsn_ptp_bvc_fsm_ops = {
.reset_notification = sgsn_ptp_bvc_reset_notif,
};
/* BVC FSM informs us about a SGSN-side reset of the signaling BVC */
static void sgsn_sig_bvc_reset_notif(uint16_t nsei, uint16_t bvci, const struct gprs_ra_id *ra_id,
uint16_t cell_id, uint8_t cause, void *priv)
{
struct gbproxy_bvc *bvc = priv;
struct gbproxy_config *cfg = bvc->nse->cfg;
struct gbproxy_nse *bss_nse;
unsigned int i;
/* delete all SGSN-side PTP BVC for this SGSN */
gbproxy_cleanup_bvcs(bvc->nse, 0);
/* FIXME: what to do about the cells? */
/* FIXME: do we really want to RESET all signaling BVC on the BSS and affect all other SGSN? */
/* we need to trigger generating a reset procedure towards each BSS side signaling BVC */
hash_for_each(cfg->bss_nses, i, bss_nse, list) {
struct gbproxy_bvc *bss_bvc = gbproxy_bvc_by_bvci(bss_nse, 0);
if (!bss_bvc) {
LOGPNSE(bss_nse, LOGL_ERROR, "Doesn't have BVC with BVCI=0 ?!?\n");
continue;
}
osmo_fsm_inst_dispatch(bss_bvc->fi, BSSGP_BVCFSM_E_REQ_RESET, &cause);
}
}
const struct bssgp_bvc_fsm_ops sgsn_sig_bvc_fsm_ops = {
.reset_notification = sgsn_sig_bvc_reset_notif,
.reset_ack_notification = sgsn_sig_bvc_reset_notif,
};
/***********************************************************************
* Signaling BVC handling
***********************************************************************/
/* process a BVC-RESET message from the BSS side */
static int rx_bvc_reset_from_bss(struct gbproxy_nse *nse, struct msgb *msg, struct tlv_parsed *tp)
{
struct gbproxy_bvc *from_bvc = NULL;
uint16_t bvci = ntohs(tlvp_val16_unal(tp, BSSGP_IE_BVCI));
uint32_t features = 0; // FIXME: make configurable
LOGPNSE(nse, LOGL_INFO, "Rx BVC-RESET (BVCI=%05u)\n", bvci);
if (bvci == 0) {
/* If we receive a BVC reset on the signalling endpoint, we
* don't want the SGSN to reset, as the signalling endpoint
* is common for all point-to-point BVCs (and thus all BTS) */
from_bvc = gbproxy_bvc_by_bvci(nse, 0);
if (!from_bvc) {
from_bvc = gbproxy_bvc_alloc(nse, 0);
OSMO_ASSERT(from_bvc);
from_bvc->fi = bssgp_bvc_fsm_alloc_sig_sgsn(from_bvc, nse->cfg->nsi, nse->nsei, features);
if (!from_bvc->fi) {
LOGPNSE(nse, LOGL_ERROR, "Cannot allocate SIG-BVC FSM\n");
gbproxy_bvc_free(from_bvc);
return -ENOMEM;
}
bssgp_bvc_fsm_set_max_pdu_len(from_bvc->fi, nse->max_sdu_len);
bssgp_bvc_fsm_set_ops(from_bvc->fi, &bss_sig_bvc_fsm_ops, from_bvc);
}
} else {
from_bvc = gbproxy_bvc_by_bvci(nse, bvci);
if (!from_bvc) {
/* if a PTP-BVC is reset, and we don't know that
* PTP-BVCI yet, we should allocate a new bvc */
from_bvc = gbproxy_bvc_alloc(nse, bvci);
OSMO_ASSERT(from_bvc);
from_bvc->fi = bssgp_bvc_fsm_alloc_ptp_sgsn(from_bvc, nse->cfg->nsi,
nse->nsei, bvci);
if (!from_bvc->fi) {
LOGPNSE(nse, LOGL_ERROR, "Cannot allocate SIG-BVC FSM\n");
gbproxy_bvc_free(from_bvc);
return -ENOMEM;
}
bssgp_bvc_fsm_set_max_pdu_len(from_bvc->fi, nse->max_sdu_len);
bssgp_bvc_fsm_set_ops(from_bvc->fi, &bss_ptp_bvc_fsm_ops, from_bvc);
}
}
/* hand into FSM for further processing */
osmo_fsm_inst_dispatch(from_bvc->fi, BSSGP_BVCFSM_E_RX_RESET, msg);
return 0;
}
/* Receive an incoming RIM message from a BSS-side NS-VC */
static int gbprox_rx_rim_from_bss(struct tlv_parsed *tp, struct gbproxy_nse *nse, struct msgb *msg, char *log_pfx,
const char *pdut_name)
{
struct gbproxy_sgsn *sgsn;
struct gbproxy_cell *dest_cell;
struct gbproxy_cell *src_cell;
struct bssgp_rim_routing_info dest_ri;
struct bssgp_rim_routing_info src_ri;
int rc;
char ri_src_str[64];
char ri_dest_str[64];
uint16_t ns_bvci = msgb_bvci(msg);
rc = bssgp_parse_rim_ri(&dest_ri, TLVP_VAL(&tp[0], BSSGP_IE_RIM_ROUTING_INFO),
TLVP_LEN(&tp[0], BSSGP_IE_RIM_ROUTING_INFO));
if (rc < 0) {
LOGP(DGPRS, LOGL_ERROR, "%s %s cannot parse destination RIM routing info\n", log_pfx, pdut_name);
return tx_status(nse, ns_bvci, BSSGP_CAUSE_INV_MAND_INF, NULL, msg);
}
rc = bssgp_parse_rim_ri(&src_ri, TLVP_VAL(&tp[1], BSSGP_IE_RIM_ROUTING_INFO),
TLVP_LEN(&tp[1], BSSGP_IE_RIM_ROUTING_INFO));
if (rc < 0) {
LOGP(DGPRS, LOGL_ERROR, "%s %s cannot parse source RIM routing info\n", log_pfx, pdut_name);
return tx_status(nse, ns_bvci, BSSGP_CAUSE_INV_MAND_INF, NULL, msg);
}
/* Since gbproxy is 2G only we do not expect to get RIM messages only from GERAN cells. */
if (src_ri.discr != BSSGP_RIM_ROUTING_INFO_GERAN) {
LOGP(DGPRS, LOGL_ERROR, "%s %s source RIM routing info is not GERAN (%s)\n", log_pfx, pdut_name,
bssgp_rim_ri_name(&src_ri));
return tx_status(nse, ns_bvci, BSSGP_CAUSE_UNKN_RIM_AI, NULL, msg);
}
/* Lookup source cell to make sure that the source RIM routing information actually belongs
* to a valid cell that we know */
src_cell = gbproxy_cell_by_cellid(nse->cfg, &src_ri.geran.raid, src_ri.geran.cid);
if (!src_cell) {
LOGP(DGPRS, LOGL_NOTICE, "%s %s cannot find cell for source RIM routing info (%s)\n", log_pfx,
pdut_name, bssgp_rim_ri_name(&src_ri));
return tx_status(nse, ns_bvci, BSSGP_CAUSE_UNKN_RIM_AI, NULL, msg);
}
/* TODO: Use bssgp_bvc_get_features_negotiated(src_cell->bss_bvc->fi) to check if the the BSS sided BVC actually
* did negotiate RIM support. If not we should respond with a BSSGP STATUS message. The cause code should be
* BSSGP_CAUSE_PDU_INCOMP_FEAT. */
/* If Destination is known by gbproxy, route directly */
if (dest_ri.discr == BSSGP_RIM_ROUTING_INFO_GERAN) {
dest_cell = gbproxy_cell_by_cellid(nse->cfg, &dest_ri.geran.raid, dest_ri.geran.cid);
if (dest_cell) {
/* TODO: Also check if dest_cell->bss_bvc is RIM-capable (see also above). If not we should
* respond with a BSSGP STATUS message as well because it also would make no sense to try
* routing the RIM message to the next RIM-capable SGSN. */
LOGP(DLBSSGP, LOGL_DEBUG, "%s %s relaying to peer (nsei=%u) RIM-PDU: src=%s, dest=%s\n",
log_pfx, pdut_name, dest_cell->bss_bvc->nse->nsei,
bssgp_rim_ri_name_buf(ri_src_str, sizeof(ri_src_str), &src_ri),
bssgp_rim_ri_name_buf(ri_dest_str, sizeof(ri_dest_str), &dest_ri));
return gbprox_relay2peer(msg, dest_cell->bss_bvc, 0);
}
}
/* Otherwise pass on to a RIM-capable SGSN */
/* TODO: We need to extend gbproxy_select_sgsn() so that it selects a RIM-capable SGSN, at the moment we just
* get any SGSN and just assume that it is RIM-capable. */
sgsn = gbproxy_select_sgsn(nse->cfg, NULL);
if (!sgsn) {
LOGP(DGPRS, LOGL_NOTICE,
"%s %s cannot route RIM message (%s to %s) since no RIM capable SGSN is found!\n", log_pfx,
pdut_name, bssgp_rim_ri_name(&src_ri), bssgp_rim_ri_name(&dest_ri));
return tx_status(nse, ns_bvci, BSSGP_CAUSE_UNKN_RIM_AI, NULL, msg);
}
LOGP(DLBSSGP, LOGL_DEBUG, "%s %s relaying to SGSN(%05u/%s) RIM-PDU: src=%s, dest=%s\n",
log_pfx, pdut_name, sgsn->nse->nsei, sgsn->name,
bssgp_rim_ri_name_buf(ri_src_str, sizeof(ri_src_str), &src_ri),
bssgp_rim_ri_name_buf(ri_dest_str, sizeof(ri_dest_str), &dest_ri));
return gbprox_relay2nse(msg, sgsn->nse, 0);
}
/* Extract the TLLI from the PDU-in-error of the STATUS PDU (if available) */
static int gbproxy_tlli_from_status_pdu(struct tlv_parsed *tp, uint32_t *tlli, char *log_pfx)
{
int rc;
int pdu_len = TLVP_LEN(&tp[0], BSSGP_IE_PDU_IN_ERROR);
const uint8_t *pdu_data = TLVP_VAL(&tp[0], BSSGP_IE_PDU_IN_ERROR);
struct bssgp_normal_hdr *bgph = (struct bssgp_normal_hdr *)pdu_data;
struct tlv_parsed tp_inner;
rc = gbproxy_decode_bssgp(bgph, pdu_len, &tp_inner, log_pfx);
/* Ignore decode failure due to truncated message */
if (rc < 0 && rc != OSMO_TLVP_ERR_OFS_BEYOND_BUFFER)
return rc;
if (TLVP_PRESENT(&tp_inner, BSSGP_IE_TLLI)) {
*tlli = osmo_load32be(TLVP_VAL(&tp_inner, BSSGP_IE_TLLI));
} else if (TLVP_PRESENT(&tp_inner, BSSGP_IE_TMSI)) {
/* we treat the TMSI like a TLLI and extract the NRI from it */
*tlli = osmo_load32be(TLVP_VAL(&tp_inner, BSSGP_IE_TMSI));
/* Convert the TMSI into a FOREIGN TLLI so it is routed appropriately */
*tlli = gprs_tmsi2tlli(*tlli, TLLI_FOREIGN);
} else {
return -ENOENT;
}
return 0;
}
/* Extract the BVCI from the PDU-in-error of the STATUS PDU (if available) */
static int gbproxy_bvci_from_status_pdu(struct tlv_parsed *tp, uint16_t *bvci, char *log_pfx)
{
int rc;
int pdu_len = TLVP_LEN(&tp[0], BSSGP_IE_PDU_IN_ERROR);
const uint8_t *pdu_data = TLVP_VAL(&tp[0], BSSGP_IE_PDU_IN_ERROR);
struct bssgp_normal_hdr *bgph = (struct bssgp_normal_hdr *)pdu_data;
struct tlv_parsed tp_inner;
rc = gbproxy_decode_bssgp(bgph, pdu_len, &tp_inner, log_pfx);
/* Ignore decode failure due to truncated message */
if (rc < 0 && rc != OSMO_TLVP_ERR_OFS_BEYOND_BUFFER)
return rc;
if (TLVP_PRESENT(&tp_inner, BSSGP_IE_BVCI))
*bvci = ntohs(tlvp_val16_unal(&tp_inner, BSSGP_IE_BVCI));
else
return -ENOENT;
return 0;
}
/* Receive an incoming signalling message from a BSS-side NS-VC */
static int gbprox_rx_sig_from_bss(struct gbproxy_nse *nse, struct msgb *msg, uint16_t ns_bvci)
{
struct bssgp_normal_hdr *bgph = (struct bssgp_normal_hdr *) msgb_bssgph(msg);
uint8_t pdu_type = bgph->pdu_type;
const char *pdut_name = osmo_tlv_prot_msg_name(&osmo_pdef_bssgp, bgph->pdu_type);
struct tlv_parsed tp[2];
int data_len = msgb_bssgp_len(msg) - sizeof(*bgph);
struct gbproxy_bvc *from_bvc = NULL;
char log_pfx[32];
uint16_t ptp_bvci;
uint32_t tlli;
int rc;
snprintf(log_pfx, sizeof(log_pfx), "NSE(%05u/BSS)-BVC(%05u/??)", nse->nsei, ns_bvci);
LOGP(DGPRS, LOGL_DEBUG, "%s Rx %s\n", log_pfx, pdut_name);
if (ns_bvci != 0 && ns_bvci != 1) {
LOGP(DGPRS, LOGL_NOTICE, "%s %s BVCI=%05u is not signalling\n", log_pfx, pdut_name, ns_bvci);
return tx_status(nse, ns_bvci, BSSGP_CAUSE_PROTO_ERR_UNSPEC, NULL, msg);
}
if (!(bssgp_pdu_type_flags(pdu_type) & BSSGP_PDUF_SIG)) {
LOGP(DGPRS, LOGL_NOTICE, "%s %s not allowed in signalling BVC\n", log_pfx, pdut_name);
return tx_status(nse, ns_bvci, BSSGP_CAUSE_PROTO_ERR_UNSPEC, NULL, msg);
}
if (!(bssgp_pdu_type_flags(pdu_type) & BSSGP_PDUF_UL)) {
LOGP(DGPRS, LOGL_NOTICE, "%s %s not allowed in uplink direction\n", log_pfx, pdut_name);
return tx_status(nse, ns_bvci, BSSGP_CAUSE_PROTO_ERR_UNSPEC, NULL, msg);
}
rc = osmo_tlv_prot_parse(&osmo_pdef_bssgp, tp, ARRAY_SIZE(tp), pdu_type, bgph->data, data_len, 0, 0,
DGPRS, log_pfx);
if (rc < 0) {
rate_ctr_inc(rate_ctr_group_get_ctr(nse->cfg->ctrg, GBPROX_GLOB_CTR_PROTO_ERR_BSS));
return tx_status_from_tlvp(nse, rc, msg);
}
/* hack to get both msg + tlv_parsed passed via osmo_fsm_inst_dispatch */
msgb_bcid(msg) = (void *)tp;
/* special case handling for some PDU types */
switch (pdu_type) {
case BSSGP_PDUT_BVC_RESET:
/* resolve or create gbproxy_bvc + handlei n BVC-FSM */
return rx_bvc_reset_from_bss(nse, msg, &tp[0]);
case BSSGP_PDUT_BVC_RESET_ACK:
ptp_bvci = ntohs(tlvp_val16_unal(&tp[0], BSSGP_IE_BVCI));
from_bvc = gbproxy_bvc_by_bvci(nse, ptp_bvci);
if (!from_bvc)
goto err_no_bvc;
return osmo_fsm_inst_dispatch(from_bvc->fi, BSSGP_BVCFSM_E_RX_RESET_ACK, msg);
case BSSGP_PDUT_BVC_BLOCK:
ptp_bvci = ntohs(tlvp_val16_unal(&tp[0], BSSGP_IE_BVCI));
from_bvc = gbproxy_bvc_by_bvci(nse, ptp_bvci);
if (!from_bvc)
goto err_no_bvc;
return osmo_fsm_inst_dispatch(from_bvc->fi, BSSGP_BVCFSM_E_RX_BLOCK, msg);
case BSSGP_PDUT_BVC_UNBLOCK:
ptp_bvci = ntohs(tlvp_val16_unal(&tp[0], BSSGP_IE_BVCI));
from_bvc = gbproxy_bvc_by_bvci(nse, ptp_bvci);
if (!from_bvc)
goto err_no_bvc;
return osmo_fsm_inst_dispatch(from_bvc->fi, BSSGP_BVCFSM_E_RX_UNBLOCK, msg);
case BSSGP_PDUT_SUSPEND:
case BSSGP_PDUT_RESUME:
{
struct gbproxy_sgsn *sgsn;
tlli = osmo_load32be(TLVP_VAL(&tp[0], BSSGP_IE_TLLI));
sgsn = gbproxy_select_sgsn(nse->cfg, &tlli);
if (!sgsn) {
LOGP(DGPRS, LOGL_ERROR, "Could not find any SGSN for TLLI, dropping message!\n");
rc = -EINVAL;
break;
}
gbproxy_tlli_cache_update(nse, tlli);
rc = gbprox_relay2nse(msg, sgsn->nse, 0);
#if 0
/* TODO: Validate the RAI for consistency with the RAI
* we expect for any of the BVC within this BSS side NSE */
memcpy(ra, TLVP_VAL(&tp[0], BSSGP_IE_ROUTEING_AREA), sizeof(from_bvc->ra));
gsm48_parse_ra(&raid, from_bvc->ra);
#endif
break;
}
case BSSGP_PDUT_STATUS:
{
struct gbproxy_sgsn *sgsn;
/* Check if the status needs to be terminated locally */
uint8_t cause = *TLVP_VAL(&tp[0], BSSGP_IE_CAUSE);
if (cause == BSSGP_CAUSE_UNKNOWN_BVCI || cause == BSSGP_CAUSE_BVCI_BLOCKED) {
/* Log and handle locally */
ptp_bvci = ntohs(tlvp_val16_unal(&tp[0], BSSGP_IE_BVCI));
LOGPNSE(nse, LOGL_ERROR, "Rx STATUS cause=0x%02x(%s) for PtP-BVC %05u\n", cause,
bssgp_cause_str(cause), ptp_bvci);
/* FIXME: Remove/block our BVC if present? */
break;
}
LOGPNSE(nse, LOGL_NOTICE, "Rx STATUS cause=0x%02x(%s) ", cause,
bssgp_cause_str(cause));
if (gbproxy_tlli_from_status_pdu(tp, &tlli, log_pfx) == 0)
sgsn = gbproxy_select_sgsn(nse->cfg, &tlli);
else
sgsn = gbproxy_select_sgsn(nse->cfg, NULL);
if (!sgsn) {
rc = -EINVAL;
break;
}
rc = gbprox_relay2nse(msg, sgsn->nse, 0);
break;
}
case BSSGP_PDUT_RAN_INFO:
case BSSGP_PDUT_RAN_INFO_REQ:
case BSSGP_PDUT_RAN_INFO_ACK:
case BSSGP_PDUT_RAN_INFO_ERROR:
case BSSGP_PDUT_RAN_INFO_APP_ERROR:
rc = gbprox_rx_rim_from_bss(tp, nse, msg, log_pfx, pdut_name);
break;
case BSSGP_PDUT_LLC_DISCARD:
/* route based on BVCI + TLLI */
ptp_bvci = ntohs(tlvp_val16_unal(&tp[0], BSSGP_IE_BVCI));
tlli = osmo_load32be(TLVP_VAL(&tp[0], BSSGP_IE_TLLI));
from_bvc = gbproxy_bvc_by_bvci(nse, ptp_bvci);
if (!from_bvc)
goto err_no_bvc;
rc = gbprox_bss2sgsn_tlli(from_bvc->cell, msg, &tlli, true);
break;
case BSSGP_PDUT_FLUSH_LL_ACK:
{
/* Route based on TLLI */
tlli = osmo_load32be(TLVP_VAL(&tp[0], BSSGP_IE_TLLI));
struct gbproxy_sgsn *sgsn = gbproxy_select_sgsn(nse->cfg, &tlli);
if (!sgsn) {
rc = -EINVAL;
break;
}
rc = gbprox_relay2nse(msg, sgsn->nse, 0);
break;
}
case BSSGP_PDUT_PAGING_PS_REJECT:
case BSSGP_PDUT_DUMMY_PAGING_PS_RESP:
{
/* Route according to IMSI<->NSE cache entry */
struct osmo_mobile_identity mi;
const uint8_t *mi_data = TLVP_VAL(&tp[0], BSSGP_IE_IMSI);
uint8_t mi_len = TLVP_LEN(&tp[0], BSSGP_IE_IMSI);
osmo_mobile_identity_decode(&mi, mi_data, mi_len, false);
nse = gbproxy_nse_by_imsi(nse->cfg, mi.imsi, CACHE_USAGE_PAGING);
if (!nse) {
return tx_status(nse, ns_bvci, BSSGP_CAUSE_INV_MAND_INF, NULL, msg);
}
OSMO_ASSERT(nse->sgsn_facing);
rc = gbprox_relay2nse(msg, nse, 0);
break;
}
case BSSGP_PDUT_MS_REGISTR_ENQ:
{
struct gbproxy_sgsn *sgsn;
struct osmo_mobile_identity mi;
const uint8_t *mi_data = TLVP_VAL(&tp[0], BSSGP_IE_IMSI);
uint8_t mi_len = TLVP_LEN(&tp[0], BSSGP_IE_IMSI);
osmo_mobile_identity_decode(&mi, mi_data, mi_len, false);
sgsn = gbproxy_select_sgsn(nse->cfg, NULL);
if (!sgsn) {
LOGP(DGPRS, LOGL_ERROR, "Could not find any SGSN, dropping message!\n");
rc = -EINVAL;
break;
}
gbproxy_imsi_cache_update(nse, mi.imsi, CACHE_USAGE_MS_REG_ENQ);
rc = gbprox_relay2nse(msg, sgsn->nse, 0);
break;
}
default:
LOGPNSE(nse, LOGL_ERROR, "Rx %s: Implementation missing\n", pdut_name);
break;
}
return rc;
err_no_bvc:
LOGPNSE(nse, LOGL_ERROR, "Rx %s: cannot find BVC for BVCI=%05u\n", pdut_name, ptp_bvci);
rate_ctr_inc(rate_ctr_group_get_ctr(nse->cfg->ctrg, GBPROX_GLOB_CTR_INV_NSEI));
return tx_status(nse, ns_bvci, BSSGP_CAUSE_INV_MAND_INF, NULL, msg);
}
/* Receive paging request from SGSN, we need to relay to proper BSS */
static int gbprox_rx_paging(struct gbproxy_nse *sgsn_nse, struct msgb *msg, const char *pdut_name,
struct tlv_parsed *tp, uint16_t ns_bvci, bool broadcast)
{
struct gbproxy_config *cfg = sgsn_nse->cfg;
struct gbproxy_bvc *sgsn_bvc, *bss_bvc;
struct gbproxy_nse *nse;
unsigned int n_nses = 0;
int errctr = GBPROX_GLOB_CTR_PROTO_ERR_SGSN;
int i, j;
if (TLVP_PRES_LEN(tp, BSSGP_IE_BVCI, 2)) {
uint16_t bvci = ntohs(tlvp_val16_unal(tp, BSSGP_IE_BVCI));
errctr = GBPROX_GLOB_CTR_OTHER_ERR;
sgsn_bvc = gbproxy_bvc_by_bvci(sgsn_nse, bvci);
if (!sgsn_bvc) {
LOGPNSE(sgsn_nse, LOGL_NOTICE, "Rx %s: unable to route: BVCI=%05u unknown\n",
pdut_name, bvci);
rate_ctr_inc(rate_ctr_group_get_ctr(cfg->ctrg, errctr));
return -EINVAL;
}
LOGPBVC(sgsn_bvc, LOGL_INFO, "Rx %s: routing by BVCI\n", pdut_name);
return gbprox_relay2peer(msg, sgsn_bvc->cell->bss_bvc, ns_bvci);
} else if (TLVP_PRES_LEN(tp, BSSGP_IE_ROUTEING_AREA, 6)) {
struct gprs_ra_id raid;
errctr = GBPROX_GLOB_CTR_INV_RAI;
gsm48_parse_ra(&raid, TLVP_VAL(tp, BSSGP_IE_ROUTEING_AREA));
/* iterate over all bvcs and dispatch the paging to each matching one */
hash_for_each(cfg->bss_nses, i, nse, list) {
hash_for_each(nse->bvcs, j, bss_bvc, list) {
/* Skip BVCs without a cell (e.g. signalling) */
if (!bss_bvc->cell)
continue;
if (gsm48_ra_equal(&bss_bvc->cell->id.raid, &raid)) {
LOGPNSE(nse, LOGL_INFO, "Rx %s: routing to NSE (RAI match)\n",
pdut_name);
gbprox_relay2peer(msg, bss_bvc, ns_bvci);
n_nses++;
/* Only send it once to each NSE */
break;
}
}
}
} else if (TLVP_PRES_LEN(tp, BSSGP_IE_LOCATION_AREA, 5)) {
struct gsm48_ra_id lac;
errctr = GBPROX_GLOB_CTR_INV_LAI;
/* iterate over all bvcs and dispatch the paging to each matching one */
hash_for_each(cfg->bss_nses, i, nse, list) {
hash_for_each(nse->bvcs, j, bss_bvc, list) {
/* Skip BVCs without a cell (e.g. signalling) */
if (!bss_bvc->cell)
continue;
gsm48_encode_ra(&lac, &bss_bvc->cell->id.raid);
if (!memcmp(&lac, TLVP_VAL(tp, BSSGP_IE_LOCATION_AREA), 5)) {
LOGPNSE(nse, LOGL_INFO, "Rx %s: routing to NSE (LAI match)\n",
pdut_name);
gbprox_relay2peer(msg, bss_bvc, ns_bvci);
n_nses++;
/* Only send it once to each NSE */
break;
}
}
}
} else if (TLVP_PRES_LEN(tp, BSSGP_IE_BSS_AREA_ID, 1) || broadcast) {
/* iterate over all bvcs and dispatch the paging to each matching one */
hash_for_each(cfg->bss_nses, i, nse, list) {
hash_for_each(nse->bvcs, j, bss_bvc, list) {
LOGPNSE(nse, LOGL_INFO, "Rx %s:routing to NSE (broadcast)\n", pdut_name);
gbprox_relay2peer(msg, bss_bvc, ns_bvci);
n_nses++;
/* Only send it once to each NSE */
break;
}
}
} else {
LOGPNSE(sgsn_nse, LOGL_ERROR, "BSSGP PAGING: unable to route, missing IE\n");
rate_ctr_inc(rate_ctr_group_get_ctr(cfg->ctrg, errctr));
}
if (n_nses == 0) {
LOGPNSE(sgsn_nse, LOGL_ERROR, "BSSGP PAGING: unable to route, no destination found\n");
rate_ctr_inc(rate_ctr_group_get_ctr(cfg->ctrg, errctr));
return -EINVAL;
}
return 0;
}
/* Receive an incoming BVC-RESET message from the SGSN */
static int rx_bvc_reset_from_sgsn(struct gbproxy_nse *nse, struct msgb *msg, struct tlv_parsed *tp,
uint16_t ns_bvci)
{
uint16_t ptp_bvci = ntohs(tlvp_val16_unal(tp, BSSGP_IE_BVCI));
struct gbproxy_bvc *from_bvc;
LOGPNSE(nse, LOGL_INFO, "Rx BVC-RESET (BVCI=%05u)\n", ptp_bvci);
if (ptp_bvci == 0) {
from_bvc = gbproxy_bvc_by_bvci(nse, 0);
OSMO_ASSERT(from_bvc);
osmo_fsm_inst_dispatch(from_bvc->fi, BSSGP_BVCFSM_E_RX_RESET, msg);
} else {
from_bvc = gbproxy_bvc_by_bvci(nse, ptp_bvci);
if (!from_bvc) {
LOGPNSE(nse, LOGL_ERROR, "Rx BVC-RESET BVCI=%05u: Cannot find BVC\n", ptp_bvci);
rate_ctr_inc(rate_ctr_group_get_ctr(nse->cfg->ctrg, GBPROX_GLOB_CTR_INV_BVCI));
return tx_status(nse, ns_bvci, BSSGP_CAUSE_UNKNOWN_BVCI, &ptp_bvci, msg);
}
osmo_fsm_inst_dispatch(from_bvc->fi, BSSGP_BVCFSM_E_RX_RESET, msg);
}
return 0;
}
/* Receive an incoming RIM message from the SGSN-side NS-VC */
static int gbprox_rx_rim_from_sgsn(struct tlv_parsed *tp, struct gbproxy_nse *nse, struct msgb *msg, char *log_pfx,
const char *pdut_name)
{
struct gbproxy_sgsn *sgsn;
struct gbproxy_cell *dest_cell;
struct bssgp_rim_routing_info dest_ri;
struct bssgp_rim_routing_info src_ri;
int rc;
char ri_src_str[64];
char ri_dest_str[64];
uint16_t ns_bvci = msgb_bvci(msg);
/* TODO: Reply with STATUS if BSSGP didn't negotiate RIM feature, see also comments in
gbprox_rx_rim_from_bss() */
rc = bssgp_parse_rim_ri(&dest_ri, TLVP_VAL(&tp[0], BSSGP_IE_RIM_ROUTING_INFO),
TLVP_LEN(&tp[0], BSSGP_IE_RIM_ROUTING_INFO));
if (rc < 0) {
LOGP(DGPRS, LOGL_ERROR, "%s %s cannot parse destination RIM routing info\n", log_pfx, pdut_name);
return tx_status(nse, ns_bvci, BSSGP_CAUSE_INV_MAND_INF, NULL, msg);
}
rc = bssgp_parse_rim_ri(&src_ri, TLVP_VAL(&tp[1], BSSGP_IE_RIM_ROUTING_INFO),
TLVP_LEN(&tp[1], BSSGP_IE_RIM_ROUTING_INFO));
if (rc < 0) {
LOGP(DGPRS, LOGL_ERROR, "%s %s cannot parse source RIM routing info\n", log_pfx, pdut_name);
return tx_status(nse, ns_bvci, BSSGP_CAUSE_INV_MAND_INF, NULL, msg);
}
/* Since gbproxy is 2G only we do not expect to get RIM messages that target non-GERAN cells. */
if (dest_ri.discr != BSSGP_RIM_ROUTING_INFO_GERAN) {
LOGP(DGPRS, LOGL_ERROR, "%s %s destination RIM routing info is not GERAN (%s)\n", log_pfx, pdut_name,
bssgp_rim_ri_name(&dest_ri));
return tx_status(nse, ns_bvci, BSSGP_CAUSE_UNKN_RIM_AI, NULL, msg);
}
/* Lookup destination cell */
dest_cell = gbproxy_cell_by_cellid(nse->cfg, &dest_ri.geran.raid, dest_ri.geran.cid);
if (!dest_cell) {
LOGP(DGPRS, LOGL_NOTICE, "%s %s cannot find cell for destination RIM routing info (%s)\n", log_pfx,
pdut_name, bssgp_rim_ri_name(&dest_ri));
return tx_status(nse, ns_bvci, BSSGP_CAUSE_UNKN_RIM_AI, NULL, msg);
}
/* TODO: Check if the BVC of the destination cell actually did negotiate RIM support, see also comments
* in gbprox_rx_rim_from_bss() */
sgsn = gbproxy_sgsn_by_nsei(nse->cfg, nse->nsei);
OSMO_ASSERT(sgsn);
LOGP(DLBSSGP, LOGL_DEBUG, "%s %s relaying from SGSN(%05u/%s) RIM-PDU: src=%s, dest=%s\n",
log_pfx, pdut_name, sgsn->nse->nsei, sgsn->name,
bssgp_rim_ri_name_buf(ri_src_str, sizeof(ri_src_str), &src_ri),
bssgp_rim_ri_name_buf(ri_dest_str, sizeof(ri_dest_str), &dest_ri));
return gbprox_relay2peer(msg, dest_cell->bss_bvc, 0);
}
/* Receive an incoming signalling message from the SGSN-side NS-VC */
static int gbprox_rx_sig_from_sgsn(struct gbproxy_nse *nse, struct msgb *msg, uint16_t ns_bvci)
{
struct bssgp_normal_hdr *bgph = (struct bssgp_normal_hdr *) msgb_bssgph(msg);
uint8_t pdu_type = bgph->pdu_type;
const char *pdut_name = osmo_tlv_prot_msg_name(&osmo_pdef_bssgp, bgph->pdu_type);
struct gbproxy_config *cfg = nse->cfg;
struct gbproxy_bvc *sgsn_bvc;
struct tlv_parsed tp[2];
int data_len;
uint16_t bvci, bvci2;
uint32_t tlli;
char log_pfx[32];
int rc = 0;
int i;
bool paging_bc = false;
snprintf(log_pfx, sizeof(log_pfx), "NSE(%05u/SGSN)-BVC(%05u/??)", nse->nsei, ns_bvci);
LOGP(DGPRS, LOGL_DEBUG, "%s Rx %s\n", log_pfx, pdut_name);
if (ns_bvci != 0 && ns_bvci != 1) {
LOGP(DGPRS, LOGL_NOTICE, "%s BVCI=%05u is not signalling\n", log_pfx, ns_bvci);
return tx_status(nse, ns_bvci, BSSGP_CAUSE_PROTO_ERR_UNSPEC, NULL, msg);
}
if (!(bssgp_pdu_type_flags(pdu_type) & BSSGP_PDUF_SIG)) {
LOGP(DGPRS, LOGL_NOTICE, "%s %s not allowed in signalling BVC\n", log_pfx, pdut_name);
return tx_status(nse, ns_bvci, BSSGP_CAUSE_PROTO_ERR_UNSPEC, NULL, msg);
}
if (!(bssgp_pdu_type_flags(pdu_type) & BSSGP_PDUF_DL)) {
LOGP(DGPRS, LOGL_NOTICE, "%s %s not allowed in downlink direction\n", log_pfx, pdut_name);
return tx_status(nse, ns_bvci, BSSGP_CAUSE_PROTO_ERR_UNSPEC, NULL, msg);
}
data_len = msgb_bssgp_len(msg) - sizeof(*bgph);
rc = osmo_tlv_prot_parse(&osmo_pdef_bssgp, tp, ARRAY_SIZE(tp), pdu_type, bgph->data, data_len, 0, 0,
DGPRS, log_pfx);
if (rc < 0) {
rc = tx_status_from_tlvp(nse, rc, msg);
rate_ctr_inc(rate_ctr_group_get_ctr(cfg->ctrg, GBPROX_GLOB_CTR_PROTO_ERR_SGSN));
return rc;
}
/* hack to get both msg + tlv_parsed passed via osmo_fsm_inst_dispatch */
msgb_bcid(msg) = (void *)tp;
switch (pdu_type) {
case BSSGP_PDUT_BVC_RESET:
/* resolve or create ggbproxy_bvc + handle in BVC-FSM */
bvci = ntohs(tlvp_val16_unal(&tp[0], BSSGP_IE_BVCI));
rc = rx_bvc_reset_from_sgsn(nse, msg, &tp[0], ns_bvci);
break;
case BSSGP_PDUT_BVC_RESET_ACK:
bvci = ntohs(tlvp_val16_unal(&tp[0], BSSGP_IE_BVCI));
sgsn_bvc = gbproxy_bvc_by_bvci(nse, bvci);
if (!sgsn_bvc)
goto err_no_bvc;
rc = osmo_fsm_inst_dispatch(sgsn_bvc->fi, BSSGP_BVCFSM_E_RX_RESET_ACK, msg);
break;
case BSSGP_PDUT_BVC_BLOCK_ACK:
bvci = ntohs(tlvp_val16_unal(&tp[0], BSSGP_IE_BVCI));
sgsn_bvc = gbproxy_bvc_by_bvci(nse, bvci);
if (!sgsn_bvc) {
/* Check if BVC was blocked before */
sgsn_bvc = gbproxy_bvc_by_bvci_inactive(nse, bvci);
if (!sgsn_bvc)
goto err_no_bvc;
}
rc = osmo_fsm_inst_dispatch(sgsn_bvc->fi, BSSGP_BVCFSM_E_RX_BLOCK_ACK, msg);
break;
case BSSGP_PDUT_BVC_UNBLOCK_ACK:
bvci = ntohs(tlvp_val16_unal(&tp[0], BSSGP_IE_BVCI));
sgsn_bvc = gbproxy_bvc_by_bvci(nse, bvci);
if (!sgsn_bvc)
goto err_no_bvc;
rc = osmo_fsm_inst_dispatch(sgsn_bvc->fi, BSSGP_BVCFSM_E_RX_UNBLOCK_ACK, msg);
break;
case BSSGP_PDUT_FLUSH_LL:
/* TODO: If we negotiate Inter-NSE re-routing or LCS-procedures we can also
* add the NSEI TLV to trigger re-routing the PDUs */
/* simple case: BVCI IE is mandatory */
bvci = ntohs(tlvp_val16_unal(&tp[0], BSSGP_IE_BVCI));
sgsn_bvc = gbproxy_bvc_by_bvci(nse, bvci);
if (!sgsn_bvc)
goto err_no_bvc;
/* bvc is not valid */
if (!sgsn_bvc->cell || !sgsn_bvc->cell->bss_bvc) {
rc = -EINVAL;
break;
}
/* When both the old and new BVCI is present:
* If old & new BVCI is on the same NSEI, forward message as is,
* otherwise remove new BVCI. */
if (TLVP_PRESENT(&tp[1], BSSGP_IE_BVCI)) {
struct gbproxy_bvc *bvc2;
struct msgb *flush;
bvci2 = ntohs(tlvp_val16_unal(&tp[1], BSSGP_IE_BVCI));
bvc2 = gbproxy_bvc_by_bvci(nse, bvci2);
/* it's the same NSEI, we can pass the message as is */
if (bvc2->nse == sgsn_bvc->nse) {
rc = gbprox_relay2peer(msg, sgsn_bvc->cell->bss_bvc, ns_bvci);
break;
}
tlli = osmo_load32be(TLVP_VAL(&tp[0], BSSGP_IE_TLLI));
/* build a new message in order to drop the old one */
flush = bssgp2_enc_flush_ll(tlli, bvci, NULL, NULL);
if (!flush) {
/* TODO: error message */
rc = -ENOMEM;
break;
}
DEBUGP(DGPRS, "NSE(%05u/%s)-BVC(%05u/??) proxying to NSE(%05u/%s)\n", msgb_nsei(msg),
!nse->sgsn_facing ? "SGSN" : "BSS", ns_bvci, nse->nsei, nse->sgsn_facing ? "SGSN" : "BSS");
rc = bssgp2_nsi_tx_ptp(nse->cfg->nsi, nse->nsei, ns_bvci, flush, tlli);
} else {
rc = gbprox_relay2peer(msg, sgsn_bvc->cell->bss_bvc, ns_bvci);
}
break;
case BSSGP_PDUT_DUMMY_PAGING_PS:
/* Routing area is optional in dummy paging and we have nothing else to go by
* so in case it is missing we need to broadcast the paging */
paging_bc = true;
/* fall through */
case BSSGP_PDUT_PAGING_PS:
{
/* Cache the IMSI<->NSE to route PAGING REJECT */
struct osmo_mobile_identity mi;
const uint8_t *mi_data = TLVP_VAL(&tp[0], BSSGP_IE_IMSI);
uint8_t mi_len = TLVP_LEN(&tp[0], BSSGP_IE_IMSI);
osmo_mobile_identity_decode(&mi, mi_data, mi_len, false);
gbproxy_imsi_cache_update(nse, mi.imsi, CACHE_USAGE_PAGING);
/* fall through */
}
case BSSGP_PDUT_PAGING_CS:
/* process the paging request (LAI/RAI lookup) */
rc = gbprox_rx_paging(nse, msg, pdut_name, &tp[0], ns_bvci, paging_bc);
break;
case BSSGP_PDUT_STATUS:
{
struct gbproxy_nse *nse_peer;
uint32_t tlli;
/* Check if the status needs to be terminated locally */
uint8_t cause = *TLVP_VAL(&tp[0], BSSGP_IE_CAUSE);
if (cause == BSSGP_CAUSE_UNKNOWN_BVCI || cause == BSSGP_CAUSE_BVCI_BLOCKED) {
/* Log and handle locally, BVCI should be present for these causes */
if (!TLVP_PRESENT(&tp[0], BSSGP_IE_BVCI)) {
LOGPNSE(nse, LOGL_ERROR, "Rx STATUS cause=0x%02x(%s), but BVCI is missing\n", cause,
bssgp_cause_str(cause));
break;
}
uint16_t ptp_bvci = ntohs(tlvp_val16_unal(&tp[0], BSSGP_IE_BVCI));
LOGPNSE(nse, LOGL_ERROR, "Rx STATUS cause=0x%02x(%s) for PtP-BVC %05u\n", cause,
bssgp_cause_str(cause), ptp_bvci);
/* FIXME: Remove/block the other BSS/SGSN BVCs if present? */
break;
}
LOGPNSE(nse, LOGL_NOTICE, "Rx STATUS cause=0x%02x(%s)\n", cause,
bssgp_cause_str(cause));
if (gbproxy_bvci_from_status_pdu(tp, &bvci, log_pfx) == 0 && bvci != 0) {
struct gbproxy_cell *cell = gbproxy_cell_by_bvci(cfg, bvci);
if ((!cell || !cell->bss_bvc || !cell->bss_bvc->nse)) {
LOGPNSE(nse, LOGL_ERROR, "Rx STATUS cause=0x%02x(%s), but can't find NSE for cell\n",
cause, bssgp_cause_str(cause));
break;
}
return gbprox_relay2nse(msg, cell->bss_bvc->nse, 0);
}
/* We can only forward this TLLI if it's in the cache (which only happens on suspend/resume) */
if (gbproxy_tlli_from_status_pdu(tp, &tlli, log_pfx) == 0) {
nse_peer = gbproxy_nse_by_tlli(cfg, tlli);
if (nse_peer)
return gbprox_relay2nse(msg, nse_peer, 0);
}
LOGPNSE(nse, LOGL_ERROR, "Unable to handle STATUS cause=0x%02x(%s)\n", cause,
bssgp_cause_str(cause));
break;
}
/* those only exist in the SGSN -> BSS direction */
case BSSGP_PDUT_SUSPEND_ACK:
case BSSGP_PDUT_SUSPEND_NACK:
case BSSGP_PDUT_RESUME_ACK:
case BSSGP_PDUT_RESUME_NACK:
{
struct gbproxy_nse *nse_peer;
uint32_t tlli = osmo_load32be(TLVP_VAL(&tp[0], BSSGP_IE_TLLI));
nse_peer = gbproxy_nse_by_tlli(cfg, tlli);
if (!nse_peer) {
LOGPNSE(nse, LOGL_ERROR, "Rx %s: Cannot find NSE\n", pdut_name);
/* TODO: Counter */
return tx_status(nse, ns_bvci, BSSGP_CAUSE_INV_MAND_INF, NULL, msg);
}
/* Delete the entry after we're done */
gbproxy_tlli_cache_remove(cfg, tlli);
LOGPNSE(nse_peer, LOGL_DEBUG, "Rx %s: forwarding\n", pdut_name);
gbprox_relay2nse(msg, nse_peer, ns_bvci);
break;
}
case BSSGP_PDUT_SGSN_INVOKE_TRACE:
case BSSGP_PDUT_OVERLOAD:
LOGPNSE(nse, LOGL_DEBUG, "Rx %s: broadcasting\n", pdut_name);
/* broadcast to all BSS-side bvcs */
hash_for_each(cfg->bss_nses, i, nse, list) {
gbprox_relay2nse(msg, nse, 0);
}
break;
case BSSGP_PDUT_RAN_INFO:
case BSSGP_PDUT_RAN_INFO_REQ:
case BSSGP_PDUT_RAN_INFO_ACK:
case BSSGP_PDUT_RAN_INFO_ERROR:
case BSSGP_PDUT_RAN_INFO_APP_ERROR:
rc = gbprox_rx_rim_from_sgsn(tp, nse, msg, log_pfx, pdut_name);
break;
case BSSGP_PDUT_MS_REGISTR_ENQ_RESP:
{
struct gbproxy_nse *nse_peer;
struct osmo_mobile_identity mi;
const uint8_t *mi_data = TLVP_VAL(&tp[0], BSSGP_IE_IMSI);
uint8_t mi_len = TLVP_LEN(&tp[0], BSSGP_IE_IMSI);
osmo_mobile_identity_decode(&mi, mi_data, mi_len, false);
nse_peer = gbproxy_nse_by_imsi(cfg, mi.imsi, CACHE_USAGE_MS_REG_ENQ);
if (!nse_peer) {
LOGPNSE(nse, LOGL_ERROR, "Rx %s: Cannot find NSE\n", pdut_name);
return tx_status(nse, ns_bvci, BSSGP_CAUSE_INV_MAND_INF, NULL, msg);
} else if (nse_peer->sgsn_facing) {
LOGPNSE(nse, LOGL_ERROR, "Forwarding %s failed: IMSI cache contains SGSN NSE", pdut_name);
return tx_status(nse, ns_bvci, BSSGP_CAUSE_PROTO_ERR_UNSPEC, NULL, msg);
}
gbproxy_imsi_cache_remove(cfg, mi.imsi, CACHE_USAGE_MS_REG_ENQ);
gbprox_relay2nse(msg, nse_peer, ns_bvci);
break;
}
default:
LOGPNSE(nse, LOGL_NOTICE, "Rx %s: Not supported\n", pdut_name);
rate_ctr_inc(rate_ctr_group_get_ctr(cfg->ctrg, GBPROX_GLOB_CTR_PROTO_ERR_SGSN));
rc = tx_status(nse, ns_bvci, BSSGP_CAUSE_PROTO_ERR_UNSPEC, NULL, msg);
break;
}
return rc;
err_no_bvc:
LOGPNSE(nse, LOGL_ERROR, "Rx %s: Cannot find BVC %05u\n", pdut_name, bvci);
rate_ctr_inc(rate_ctr_group_get_ctr(cfg->ctrg, GBPROX_GLOB_CTR_INV_BVCI));
return tx_status(nse, ns_bvci, BSSGP_CAUSE_INV_MAND_INF, NULL, msg);
}
/***********************************************************************
* libosmogb NS/BSSGP integration
***********************************************************************/
int gbprox_bssgp_send_cb(void *ctx, struct msgb *msg)
{
int rc;
struct gbproxy_config *cfg = (struct gbproxy_config *) ctx;
struct gprs_ns2_inst *nsi = cfg->nsi;
struct osmo_gprs_ns2_prim nsp = {};
nsp.bvci = msgb_bvci(msg);
nsp.nsei = msgb_nsei(msg);
osmo_prim_init(&nsp.oph, SAP_NS, GPRS_NS2_PRIM_UNIT_DATA, PRIM_OP_REQUEST, msg);
rc = gprs_ns2_recv_prim(nsi, &nsp.oph);
return rc;
}
/* Main input function for Gb proxy */
int gbprox_rcvmsg(void *ctx, struct msgb *msg)
{
struct gbproxy_config *cfg = (struct gbproxy_config *) ctx;
uint16_t ns_bvci = msgb_bvci(msg);
uint16_t nsei = msgb_nsei(msg);
struct gbproxy_nse *nse;
nse = gbproxy_nse_by_nsei(cfg, nsei, NSE_F_SGSN);
if (nse) {
/* ensure minimum length to decode PDU type */
if (msgb_bssgp_len(msg) < sizeof(struct bssgp_normal_hdr))
return tx_status(nse, ns_bvci, BSSGP_CAUSE_SEM_INCORR_PDU, NULL, msg);
if (ns_bvci == 0 || ns_bvci == 1)
return gbprox_rx_sig_from_sgsn(nse, msg, ns_bvci);
else
return gbprox_rx_ptp_from_sgsn(nse, msg, ns_bvci);
}
nse = gbproxy_nse_by_nsei(cfg, nsei, NSE_F_BSS);
if (!nse) {
LOGP(DGPRS, LOGL_NOTICE, "NSE(%05u/BSS) not known -> allocating\n", nsei);
nse = gbproxy_nse_alloc(cfg, nsei, false);
}
if (nse) {
/* ensure minimum length to decode PDU type */
if (msgb_bssgp_len(msg) < sizeof(struct bssgp_normal_hdr))
return tx_status(nse, ns_bvci, BSSGP_CAUSE_SEM_INCORR_PDU, NULL, msg);
if (ns_bvci == 0 || ns_bvci == 1)
return gbprox_rx_sig_from_bss(nse, msg, ns_bvci);
else
return gbprox_rx_ptp_from_bss(nse, msg, ns_bvci);
}
return 0;
}
/* TODO: What about handling:
* GPRS_NS2_AFF_CAUSE_VC_FAILURE,
GPRS_NS2_AFF_CAUSE_VC_RECOVERY,
osmocom own causes
GPRS_NS2_AFF_CAUSE_SNS_CONFIGURED,
GPRS_NS2_AFF_CAUSE_SNS_FAILURE,
*/
void gprs_ns_prim_status_cb(struct gbproxy_config *cfg, struct osmo_gprs_ns2_prim *nsp)
{
int i;
struct gbproxy_bvc *bvc;
struct gbproxy_nse *nse;
switch (nsp->u.status.cause) {
case GPRS_NS2_AFF_CAUSE_SNS_FAILURE:
case GPRS_NS2_AFF_CAUSE_SNS_CONFIGURED:
break;
case GPRS_NS2_AFF_CAUSE_RECOVERY:
LOGP(DGPRS, LOGL_NOTICE, "NS-NSE %d became available\n", nsp->nsei);
nse = gbproxy_nse_by_nsei(cfg, nsp->nsei, NSE_F_SGSN);
if (nse) {
nse->alive = true;
// Update the NSE max SDU len
nse->max_sdu_len = nsp->u.status.mtu;
uint8_t cause = BSSGP_CAUSE_OML_INTERV;
bvc = gbproxy_bvc_by_bvci(nse, 0);
if (bvc) {
bssgp_bvc_fsm_set_max_pdu_len(bvc->fi, nse->max_sdu_len);
osmo_fsm_inst_dispatch(bvc->fi, BSSGP_BVCFSM_E_REQ_RESET, &cause);
}
}
break;
case GPRS_NS2_AFF_CAUSE_FAILURE:
nse = gbproxy_nse_by_nsei(cfg, nsp->nsei, NSE_F_BSS | NSE_F_SGSN);
if (!nse) {
LOGP(DGPRS, LOGL_ERROR, "Unknown NSE(%05d) became unavailable\n", nsp->nsei);
break;
}
nse->alive = false;
if (nse->sgsn_facing) {
struct hlist_node *ntmp;
/* SGSN */
/* TODO: When to block all PtP towards bss? Only if all SGSN are down? */
hash_for_each_safe(nse->bvcs, i, ntmp, bvc, list) {
if (bvc->bvci == 0)
continue;
gbproxy_bvc_free(bvc);
}
rate_ctr_inc(rate_ctr_group_get_ctr(cfg->ctrg, GBPROX_GLOB_CTR_RESTART_RESET_SGSN));
} else {
/* BSS became unavailable
* Block matching PtP-BVCs on SGSN-side */
hash_for_each(nse->bvcs, i, bvc, list) {
if (bvc->bvci == 0)
continue;
/* Get BVC for each SGSN and send block request */
struct gbproxy_cell *cell = bvc->cell;
for (int j = 0; j < GBPROXY_MAX_NR_SGSN; j++) {
struct gbproxy_bvc *sgsn_bvc = cell->sgsn_bvc[j];
if (!sgsn_bvc)
continue;
/* Block BVC, indicate BSS equipment failure */
uint8_t cause = BSSGP_CAUSE_EQUIP_FAIL;
osmo_fsm_inst_dispatch(sgsn_bvc->fi, BSSGP_BVCFSM_E_REQ_BLOCK, &cause);
sgsn_bvc->inactive = true;
}
}
/* This frees the BVCs for us as well */
gbproxy_nse_free(nse);
}
LOGP(DGPRS, LOGL_NOTICE, "NS-NSE %d became unavailable\n", nsp->nsei);
break;
default:
LOGP(DGPRS, LOGL_NOTICE, "NS: Unknown NS-STATUS.ind cause=%s from NS\n",
gprs_ns2_aff_cause_prim_str(nsp->u.status.cause));
break;
}
}
/* called by the ns layer */
int gprs_ns2_prim_cb(struct osmo_prim_hdr *oph, void *ctx)
{
struct osmo_gprs_ns2_prim *nsp;
struct gbproxy_config *cfg = (struct gbproxy_config *) ctx;
uintptr_t bvci;
int rc = 0;
if (oph->sap != SAP_NS)
return 0;
nsp = container_of(oph, struct osmo_gprs_ns2_prim, oph);
if (oph->operation != PRIM_OP_INDICATION) {
LOGP(DGPRS, LOGL_NOTICE, "NS: Unexpected primitive operation %s from NS\n",
get_value_string(osmo_prim_op_names, oph->operation));
return 0;
}
switch (oph->primitive) {
case GPRS_NS2_PRIM_UNIT_DATA:
/* hand the message into the BSSGP implementation */
msgb_bssgph(oph->msg) = oph->msg->l3h;
msgb_bvci(oph->msg) = nsp->bvci;
msgb_nsei(oph->msg) = nsp->nsei;
bvci = nsp->bvci | BVC_LOG_CTX_FLAG;
log_set_context(LOG_CTX_GB_BVC, (void *)bvci);
rc = gbprox_rcvmsg(cfg, oph->msg);
msgb_free(oph->msg);
break;
case GPRS_NS2_PRIM_STATUS:
gprs_ns_prim_status_cb(cfg, nsp);
break;
default:
LOGP(DGPRS, LOGL_NOTICE, "NS: Unknown prim %s %s from NS\n",
gprs_ns2_prim_str(oph->primitive),
get_value_string(osmo_prim_op_names, oph->operation));
break;
}
return rc;
}
void gbprox_reset(struct gbproxy_config *cfg)
{
struct gbproxy_nse *nse;
struct hlist_node *ntmp;
int i, j;
hash_for_each_safe(cfg->bss_nses, i, ntmp, nse, list) {
struct gbproxy_bvc *bvc;
struct hlist_node *tmp;
hash_for_each_safe(nse->bvcs, j, tmp, bvc, list)
gbproxy_bvc_free(bvc);
gbproxy_nse_free(nse);
}
/* FIXME: cells */
/* FIXME: SGSN side BVCs (except signaling) */
rate_ctr_group_free(cfg->ctrg);
gbproxy_init_config(cfg);
}
static void tlli_cache_cleanup(void *data)
{
struct gbproxy_config *cfg = data;
gbproxy_tlli_cache_cleanup(cfg);
/* TODO: Disable timer when cache is empty */
osmo_timer_schedule(&cfg->tlli_cache.timer, 2, 0);
}
static void imsi_cache_cleanup(void *data)
{
struct gbproxy_config *cfg = data;
gbproxy_imsi_cache_cleanup(cfg);
/* TODO: Disable timer when cache is empty */
osmo_timer_schedule(&cfg->imsi_cache.timer, 2, 0);
}
int gbproxy_init_config(struct gbproxy_config *cfg)
{
struct timespec tp;
/* by default we advertise 100% of the BSS-side capacity to _each_ SGSN */
cfg->pool.bvc_fc_ratio = 100;
cfg->pool.null_nri_ranges = osmo_nri_ranges_alloc(cfg);
/* TODO: Make configurable */
cfg->tlli_cache.timeout = 10;
cfg->imsi_cache.timeout = 10;
hash_init(cfg->bss_nses);
hash_init(cfg->sgsn_nses);
hash_init(cfg->cells);
hash_init(cfg->tlli_cache.entries);
INIT_LLIST_HEAD(&cfg->sgsns);
osmo_timer_setup(&cfg->tlli_cache.timer, tlli_cache_cleanup, cfg);
osmo_timer_schedule(&cfg->tlli_cache.timer, 2, 0);
/* We could also combine both timers */
osmo_timer_setup(&cfg->imsi_cache.timer, imsi_cache_cleanup, cfg);
osmo_timer_schedule(&cfg->imsi_cache.timer, 2, 0);
cfg->ctrg = rate_ctr_group_alloc(tall_sgsn_ctx, &global_ctrg_desc, 0);
if (!cfg->ctrg) {
LOGP(DGPRS, LOGL_ERROR, "Cannot allocate global counter group!\n");
return -1;
}
osmo_clock_gettime(CLOCK_REALTIME, &tp);
osmo_fsm_log_timeouts(true);
return 0;
}