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osmo-gbproxy/src/gb_proxy.c

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/* NS-over-IP proxy */
/* (C) 2010 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/talloc.h>
#include <osmocom/core/select.h>
#include <osmocom/core/rate_ctr.h>
#include <osmocom/core/stats.h>
#include <osmocom/gprs/gprs_ns2.h>
#include <osmocom/gprs/gprs_bssgp.h>
#include <osmocom/gprs/gprs_bssgp_bss.h>
#include <osmocom/gsm/gsm_utils.h>
#include <osmocom/sgsn/signal.h>
#include <osmocom/sgsn/debug.h>
#include <osmocom/sgsn/gprs_gb_parse.h>
#include <osmocom/sgsn/gb_proxy.h>
#include <osmocom/sgsn/gprs_llc.h>
#include <osmocom/gsm/protocol/gsm_04_08_gprs.h>
#include <osmocom/sgsn/gprs_utils.h>
extern void *tall_sgsn_ctx;
static const struct rate_ctr_desc global_ctr_description[] = {
{ "inv-bvci", "Invalid BVC Identifier " },
{ "inv-lai", "Invalid Location Area Identifier" },
{ "inv-rai", "Invalid Routing Area Identifier " },
{ "inv-nsei", "No BVC established for NSEI " },
{ "proto-err:bss", "BSSGP protocol error (BSS )" },
{ "proto-err:sgsn", "BSSGP protocol error (SGSN)" },
{ "not-supp:bss", "Feature not supported (BSS )" },
{ "not-supp:sgsn", "Feature not supported (SGSN)" },
{ "restart:sgsn", "Restarted RESET procedure (SGSN)" },
{ "tx-err:sgsn", "NS Transmission error (SGSN)" },
{ "error", "Other error " },
{ "mod-peer-err", "Patch error: no peer " },
};
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,
};
static int gbprox_relay2peer(struct msgb *old_msg, struct gbproxy_bvc *bvc,
uint16_t ns_bvci);
static int gbprox_relay2sgsn(struct gbproxy_config *cfg, struct msgb *old_msg,
uint16_t ns_bvci, uint16_t sgsn_nsei);
static int check_bvc_nsei(struct gbproxy_bvc *bvc, uint16_t nsei)
{
OSMO_ASSERT(bvc);
OSMO_ASSERT(bvc->nse);
if (bvc->nse->nsei != nsei) {
LOGPBVC(bvc, LOGL_NOTICE, "Peer entry doesn't match current NSEI "
"via NSE(%05u/BSS)\n", nsei);
rate_ctr_inc(&bvc->ctrg->ctr[GBPROX_PEER_CTR_INV_NSEI]);
return 0;
}
return 1;
}
/* 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);
}
/* 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(&cfg->ctrg->ctr[GBPROX_GLOB_CTR_TX_ERR_SGSN]);
return rc;
}
/* 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 osmo_gprs_ns2_prim nsp = {};
struct msgb *msg = bssgp_msgb_copy(old_msg, "msgb_relay2nse");
uint32_t tlli;
int rc;
DEBUGP(DGPRS, "NSE(%05u/SGSN)-BVC(%05u) proxying SGSN->BSS NSE(%05u/BSS)\n",
msgb_nsei(msg), ns_bvci, nse->nsei);
nsp.bvci = ns_bvci;
nsp.nsei = nse->nsei;
/* 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. */
if (gprs_gb_parse_tlli(msgb_data(msg), msgb_length(msg), &tlli) == 1)
nsp.u.unitdata.link_selector = tlli;
osmo_prim_init(&nsp.oph, SAP_NS, PRIM_NS_UNIT_DATA,
PRIM_OP_REQUEST, msg);
rc = gprs_ns2_recv_prim(nsi, &nsp.oph);
/* FIXME: We need a counter group for gbproxy_nse */
//if (rc < 0)
// rate_ctr_inc(&bvc->ctrg->ctr[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(&bvc->ctrg->ctr[GBPROX_PEER_CTR_TX_ERR]);
return rc;
}
static int block_unblock_bvc(struct gbproxy_config *cfg, uint16_t ptp_bvci, uint8_t pdu_type)
{
struct gbproxy_bvc *bvc;
bvc = gbproxy_bvc_by_bvci(cfg, ptp_bvci);
if (!bvc) {
LOGP(DGPRS, LOGL_ERROR, "BVC(%05u/??) Cannot find BSS\n",
ptp_bvci);
rate_ctr_inc(&cfg->ctrg->ctr[GBPROX_GLOB_CTR_INV_BVCI]);
return -ENOENT;
}
switch (pdu_type) {
case BSSGP_PDUT_BVC_BLOCK_ACK:
bvc->blocked = true;
rate_ctr_inc(&bvc->ctrg->ctr[GBPROX_PEER_CTR_BLOCKED]);
break;
case BSSGP_PDUT_BVC_UNBLOCK_ACK:
bvc->blocked = false;
rate_ctr_inc(&bvc->ctrg->ctr[GBPROX_PEER_CTR_UNBLOCKED]);
break;
default:
break;
}
return 0;
}
/* Send a message to a bvc identified by ptp_bvci but using ns_bvci
* in the NS hdr */
static int gbprox_relay2bvci(struct gbproxy_config *cfg, struct msgb *msg, uint16_t ptp_bvci,
uint16_t ns_bvci)
{
struct gbproxy_bvc *bvc;
bvc = gbproxy_bvc_by_bvci(cfg, ptp_bvci);
if (!bvc) {
LOGP(DGPRS, LOGL_ERROR, "BVC(%05u/??) Cannot find BSS\n",
ptp_bvci);
rate_ctr_inc(&cfg->ctrg->ctr[GBPROX_GLOB_CTR_INV_BVCI]);
return -ENOENT;
}
return gbprox_relay2peer(msg, bvc, ns_bvci);
}
int bssgp_prim_cb(struct osmo_prim_hdr *oph, void *ctx)
{
return 0;
}
/* Receive an incoming PTP message from a BSS-side NS-VC */
static int gbprox_rx_ptp_from_bss(struct gbproxy_config *cfg,
struct msgb *msg, uint16_t nsei,
uint16_t ns_bvci)
{
struct gbproxy_bvc *bvc;
bvc = gbproxy_bvc_by_bvci(cfg, ns_bvci);
if (!bvc) {
LOGP(DGPRS, LOGL_NOTICE, "BVC(%05u/??) Didn't find bvc "
"for PTP message from NSE(%05u/BSS), "
"discarding message\n",
ns_bvci, nsei);
return bssgp_tx_status(BSSGP_CAUSE_UNKNOWN_BVCI,
&ns_bvci, msg);
}
/* TODO: Should we discard this message if the check fails */
check_bvc_nsei(bvc, nsei);
return gbprox_relay2sgsn(cfg, msg, ns_bvci, cfg->nsip_sgsn_nsei);
}
/* Receive an incoming PTP message from a SGSN-side NS-VC */
static int gbprox_rx_ptp_from_sgsn(struct gbproxy_config *cfg,
struct msgb *msg, uint16_t nsei,
uint16_t ns_bvci)
{
struct gbproxy_bvc *bvc;
bvc = gbproxy_bvc_by_bvci(cfg, ns_bvci);
/* Send status messages before patching */
if (!bvc) {
LOGP(DGPRS, LOGL_INFO, "BVC(%05u/??) Didn't find bvc for "
"for message from NSE(%05u/SGSN)\n",
ns_bvci, nsei);
rate_ctr_inc(&cfg->ctrg->
ctr[GBPROX_GLOB_CTR_INV_BVCI]);
return bssgp_tx_status(BSSGP_CAUSE_UNKNOWN_BVCI,
&ns_bvci, msg);
}
if (bvc->blocked) {
LOGPBVC(bvc, LOGL_NOTICE, "Dropping PDU for "
"blocked BVC via NSE(%05u/SGSN)\n", nsei);
rate_ctr_inc(&bvc->ctrg->ctr[GBPROX_PEER_CTR_DROPPED]);
return bssgp_tx_status(BSSGP_CAUSE_BVCI_BLOCKED, &ns_bvci, msg);
}
return gbprox_relay2peer(msg, bvc, ns_bvci);
}
/* process a BVC-RESET message from the BSS side */
static int gbprox_rx_bvc_reset_from_bss(struct gbproxy_config *cfg, struct msgb *msg,
uint16_t nsei, struct tlv_parsed *tp)
{
struct gbproxy_bvc *from_bvc = NULL;
uint16_t bvci;
if (!TLVP_PRES_LEN(tp, BSSGP_IE_BVCI, 2) || !TLVP_PRES_LEN(tp, BSSGP_IE_CAUSE, 1)) {
rate_ctr_inc(&cfg->ctrg->ctr[GBPROX_GLOB_CTR_PROTO_ERR_BSS]);
return bssgp_tx_status(BSSGP_CAUSE_MISSING_MAND_IE, NULL, msg);
}
bvci = ntohs(tlvp_val16_unal(tp, BSSGP_IE_BVCI));
LOGP(DGPRS, LOGL_INFO, "NSE(%05u) Rx BVC RESET (BVCI=%05u)\n", nsei, 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) */
/* Ensure the NSE bvc is there and clear all PtP BVCs */
struct gbproxy_nse *nse = gbproxy_nse_by_nsei_or_new(cfg, nsei);
if (!nse) {
LOGP(DGPRS, LOGL_ERROR, "Could not create NSE(%05u)\n", nsei);
bssgp_tx_status(BSSGP_CAUSE_PROTO_ERR_UNSPEC, 0, msg);
return 0;
}
gbproxy_cleanup_bvcs(cfg, nsei, 0);
/* FIXME: only do this if SGSN is alive! */
LOGPNSE(nse, LOGL_INFO, "Tx fake BVC RESET ACK of BVCI=0\n");
bssgp_tx_simple_bvci(BSSGP_PDUT_BVC_RESET_ACK, nsei, 0, 0);
return 0;
} else {
from_bvc = gbproxy_bvc_by_bvci(cfg, bvci);
if (!from_bvc) {
struct gbproxy_nse *nse = gbproxy_nse_by_nsei(cfg, nsei);
if (!nse) {
LOGP(DGPRS, LOGL_NOTICE, "NSE(%05u) Got PtP BVC reset before signalling reset for "
"BVCI=%05u\n", nsei, bvci);
bssgp_tx_status(BSSGP_CAUSE_PDU_INCOMP_STATE, NULL, msg);
return 0;
}
/* 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);
LOGPBVC(from_bvc, LOGL_INFO, "Allocated new bvc\n");
}
/* Could have moved to a different NSE */
if (!check_bvc_nsei(from_bvc, nsei)) {
LOGPBVC(from_bvc, LOGL_NOTICE, "moving bvc to NSE(%05u)\n", nsei);
struct gbproxy_nse *nse_new = gbproxy_nse_by_nsei(cfg, nsei);
if (!nse_new) {
LOGP(DGPRS, LOGL_NOTICE, "NSE(%05u) Got PtP BVC reset before signalling reset for "
"BVCI=%05u\n", bvci, nsei);
bssgp_tx_status(BSSGP_CAUSE_PDU_INCOMP_STATE, NULL, msg);
return 0;
}
/* Move bvc to different NSE */
gbproxy_bvc_move(from_bvc, nse_new);
}
if (TLVP_PRES_LEN(tp, BSSGP_IE_CELL_ID, 8)) {
struct gprs_ra_id raid;
/* We have a Cell Identifier present in this
* PDU, this means we can extend our local
* state information about this particular cell
* */
memcpy(from_bvc->ra, TLVP_VAL(tp, BSSGP_IE_CELL_ID), sizeof(from_bvc->ra));
gsm48_parse_ra(&raid, from_bvc->ra);
LOGPBVC(from_bvc, LOGL_INFO, "Cell ID %s\n", osmo_rai_name(&raid));
}
}
/* continue processing / relaying to SGSN[s] */
return 1;
}
/* Receive an incoming signalling message from a BSS-side NS-VC */
static int gbprox_rx_sig_from_bss(struct gbproxy_config *cfg,
struct msgb *msg, uint16_t nsei,
uint16_t ns_bvci)
{
struct bssgp_normal_hdr *bgph = (struct bssgp_normal_hdr *) msgb_bssgph(msg);
struct tlv_parsed tp;
uint8_t pdu_type = bgph->pdu_type;
int data_len = msgb_bssgp_len(msg) - sizeof(*bgph);
struct gbproxy_bvc *from_bvc = NULL;
struct gprs_ra_id raid;
int rc;
if (ns_bvci != 0 && ns_bvci != 1) {
LOGP(DGPRS, LOGL_NOTICE, "NSE(%05u) BVCI=%05u is not signalling\n",
nsei, ns_bvci);
return -EINVAL;
}
/* we actually should never see those two for BVCI == 0, but double-check
* just to make sure */
if (pdu_type == BSSGP_PDUT_UL_UNITDATA ||
pdu_type == BSSGP_PDUT_DL_UNITDATA) {
LOGP(DGPRS, LOGL_NOTICE, "NSE(%05u) UNITDATA not allowed in "
"signalling\n", nsei);
return -EINVAL;
}
bssgp_tlv_parse(&tp, bgph->data, data_len);
switch (pdu_type) {
case BSSGP_PDUT_SUSPEND:
case BSSGP_PDUT_RESUME:
/* We implement RAI snooping during SUSPEND/RESUME, since it
* establishes a relationsip between BVCI/bvc and the routeing
* area identification. The snooped information is then used
* for routing the {SUSPEND,RESUME}_[N]ACK back to the correct
* BSSGP */
if (!TLVP_PRES_LEN(&tp, BSSGP_IE_ROUTEING_AREA, 6))
goto err_mand_ie;
from_bvc = gbproxy_bvc_by_nsei(cfg, nsei);
if (!from_bvc)
goto err_no_bvc;
memcpy(from_bvc->ra, TLVP_VAL(&tp, BSSGP_IE_ROUTEING_AREA),
sizeof(from_bvc->ra));
gsm48_parse_ra(&raid, from_bvc->ra);
LOGPBVC(from_bvc, LOGL_INFO, "BSSGP SUSPEND/RESUME "
"RAI snooping: RAI %s\n",
osmo_rai_name(&raid));
/* FIXME: This only supports one BSS per RA */
break;
case BSSGP_PDUT_BVC_RESET:
rc = gbprox_rx_bvc_reset_from_bss(cfg, msg, nsei, &tp);
/* if function retruns 0, we terminate processing here */
if (rc == 0)
return 0;
break;
}
return gbprox_relay2sgsn(cfg, msg, ns_bvci, cfg->nsip_sgsn_nsei);
err_no_bvc:
LOGP(DGPRS, LOGL_ERROR, "NSE(%05u/BSS) cannot find bvc based on NSEI\n",
nsei);
rate_ctr_inc(&cfg->ctrg->ctr[GBPROX_GLOB_CTR_INV_NSEI]);
return bssgp_tx_status(BSSGP_CAUSE_INV_MAND_INF, NULL, msg);
err_mand_ie:
LOGP(DGPRS, LOGL_ERROR, "NSE(%05u/BSS) missing mandatory RA IE\n",
nsei);
rate_ctr_inc(&cfg->ctrg->ctr[GBPROX_GLOB_CTR_PROTO_ERR_BSS]);
return bssgp_tx_status(BSSGP_CAUSE_MISSING_MAND_IE, NULL, msg);
}
/* Receive paging request from SGSN, we need to relay to proper BSS */
static int gbprox_rx_paging(struct gbproxy_config *cfg, struct msgb *msg, struct tlv_parsed *tp,
uint32_t nsei, uint16_t ns_bvci)
{
struct gbproxy_nse *nse;
struct gbproxy_bvc *bvc;
unsigned int n_nses = 0;
int errctr = GBPROX_GLOB_CTR_PROTO_ERR_SGSN;
int i, j;
/* FIXME: Handle paging logic to only page each matching NSE */
LOGP(DGPRS, LOGL_INFO, "NSE(%05u/SGSN) BSSGP PAGING\n",
nsei);
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;
bvc = gbproxy_bvc_by_bvci(cfg, bvci);
if (!bvc) {
LOGP(DGPRS, LOGL_NOTICE, "NSE(%05u/SGSN) BSSGP PAGING: "
"unable to route: BVCI=%05u unknown\n", nsei, bvci);
rate_ctr_inc(&cfg->ctrg->ctr[errctr]);
return -EINVAL;
}
LOGPBVC(bvc, LOGL_INFO, "routing by BVCI\n");
return gbprox_relay2peer(msg, bvc, ns_bvci);
} else if (TLVP_PRES_LEN(tp, BSSGP_IE_ROUTEING_AREA, 6)) {
errctr = GBPROX_GLOB_CTR_INV_RAI;
/* 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, bvc, list) {
if (!memcmp(bvc->ra, TLVP_VAL(tp, BSSGP_IE_ROUTEING_AREA), 6)) {
LOGPNSE(nse, LOGL_INFO, "routing to NSE (RAI match)\n");
gbprox_relay2nse(msg, nse, ns_bvci);
n_nses++;
/* Only send it once to each NSE */
break;
}
}
}
} else if (TLVP_PRES_LEN(tp, BSSGP_IE_LOCATION_AREA, 5)) {
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, bvc, list) {
if (!memcmp(bvc->ra, TLVP_VAL(tp, BSSGP_IE_LOCATION_AREA), 5)) {
LOGPNSE(nse, LOGL_INFO, "routing to NSE (LAI match)\n");
gbprox_relay2nse(msg, nse, ns_bvci);
n_nses++;
/* Only send it once to each NSE */
break;
}
}
}
} else if (TLVP_PRES_LEN(tp, BSSGP_IE_BSS_AREA_ID, 1)) {
/* 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, bvc, list) {
LOGPNSE(nse, LOGL_INFO, "routing to NSE (broadcast)\n");
gbprox_relay2nse(msg, nse, ns_bvci);
n_nses++;
/* Only send it once to each NSE */
break;
}
}
} else {
LOGP(DGPRS, LOGL_ERROR, "NSE(%05u/SGSN) BSSGP PAGING: "
"unable to route, missing IE\n", nsei);
rate_ctr_inc(&cfg->ctrg->ctr[errctr]);
}
if (n_nses == 0) {
LOGP(DGPRS, LOGL_ERROR, "NSE(%05u/SGSN) BSSGP PAGING: "
"unable to route, no destination found\n", nsei);
rate_ctr_inc(&cfg->ctrg->ctr[errctr]);
return -EINVAL;
}
return 0;
}
/* Receive an incoming BVC-RESET message from the SGSN */
static int rx_reset_from_sgsn(struct gbproxy_config *cfg,
struct msgb *orig_msg,
struct msgb *msg, struct tlv_parsed *tp,
uint32_t nsei, uint16_t ns_bvci)
{
struct gbproxy_nse *nse;
struct gbproxy_bvc *bvc;
uint16_t ptp_bvci;
int i, j;
if (!TLVP_PRES_LEN(tp, BSSGP_IE_BVCI, 2)) {
rate_ctr_inc(&cfg->ctrg->
ctr[GBPROX_GLOB_CTR_PROTO_ERR_SGSN]);
return bssgp_tx_status(BSSGP_CAUSE_MISSING_MAND_IE,
NULL, orig_msg);
}
ptp_bvci = ntohs(tlvp_val16_unal(tp, BSSGP_IE_BVCI));
if (ptp_bvci >= 2) {
/* A reset for a PTP BVC was received, forward it to its
* respective bvc */
bvc = gbproxy_bvc_by_bvci(cfg, ptp_bvci);
if (!bvc) {
LOGP(DGPRS, LOGL_ERROR, "NSE(%05u/SGSN) BVCI=%05u: Cannot find BSS\n",
nsei, ptp_bvci);
rate_ctr_inc(&cfg->ctrg->
ctr[GBPROX_GLOB_CTR_INV_BVCI]);
return bssgp_tx_status(BSSGP_CAUSE_UNKNOWN_BVCI,
&ptp_bvci, orig_msg);
}
return gbprox_relay2peer(msg, bvc, ns_bvci);
}
/* A reset for the Signalling entity has been received
* from the SGSN. As the signalling BVCI is shared
* among all the BSS's that we multiplex, it needs to
* be relayed */
hash_for_each(cfg->bss_nses, i, nse, list) {
hash_for_each(nse->bvcs, j, bvc, list)
gbprox_relay2peer(msg, bvc, ns_bvci);
}
return 0;
}
/* Receive an incoming signalling message from the SGSN-side NS-VC */
static int gbprox_rx_sig_from_sgsn(struct gbproxy_config *cfg,
struct msgb *orig_msg, uint32_t nsei,
uint16_t ns_bvci)
{
struct bssgp_normal_hdr *bgph =
(struct bssgp_normal_hdr *) msgb_bssgph(orig_msg);
struct tlv_parsed tp;
uint8_t pdu_type = bgph->pdu_type;
int data_len;
struct gbproxy_nse *nse;
struct gbproxy_bvc *bvc;
uint16_t bvci;
struct msgb *msg;
int rc = 0;
int cause;
int i;
if (ns_bvci != 0 && ns_bvci != 1) {
LOGP(DGPRS, LOGL_NOTICE, "NSE(%05u/SGSN) BVCI=%05u is not "
"signalling\n", nsei, ns_bvci);
/* FIXME: Send proper error message */
return -EINVAL;
}
/* we actually should never see those two for BVCI == 0, but double-check
* just to make sure */
if (pdu_type == BSSGP_PDUT_UL_UNITDATA ||
pdu_type == BSSGP_PDUT_DL_UNITDATA) {
LOGP(DGPRS, LOGL_NOTICE, "NSE(%05u/SGSN) UNITDATA not allowed in "
"signalling\n", nsei);
return bssgp_tx_status(BSSGP_CAUSE_PROTO_ERR_UNSPEC, NULL, orig_msg);
}
msg = bssgp_msgb_copy(orig_msg, "rx_sig_from_sgsn");
/* Update message info */
bgph = (struct bssgp_normal_hdr *) msgb_bssgph(msg);
data_len = msgb_bssgp_len(orig_msg) - sizeof(*bgph);
rc = bssgp_tlv_parse(&tp, bgph->data, data_len);
switch (pdu_type) {
case BSSGP_PDUT_BVC_RESET:
rc = rx_reset_from_sgsn(cfg, msg, orig_msg, &tp, nsei, ns_bvci);
break;
case BSSGP_PDUT_BVC_RESET_ACK:
/* simple case: BVCI IE is mandatory */
if (!TLVP_PRES_LEN(&tp, BSSGP_IE_BVCI, 2))
goto err_mand_ie;
bvci = ntohs(tlvp_val16_unal(&tp, BSSGP_IE_BVCI));
if (bvci == BVCI_SIGNALLING) {
/* TODO: Reset all PTP BVCIs */
} else {
rc = gbprox_relay2bvci(cfg, msg, bvci, ns_bvci);
}
break;
case BSSGP_PDUT_FLUSH_LL:
/* simple case: BVCI IE is mandatory */
if (!TLVP_PRES_LEN(&tp, BSSGP_IE_BVCI, 2))
goto err_mand_ie;
bvci = ntohs(tlvp_val16_unal(&tp, BSSGP_IE_BVCI));
rc = gbprox_relay2bvci(cfg, msg, bvci, ns_bvci);
break;
case BSSGP_PDUT_PAGING_PS:
case BSSGP_PDUT_PAGING_CS:
/* process the paging request (LAI/RAI lookup) */
rc = gbprox_rx_paging(cfg, msg, &tp, nsei, ns_bvci);
break;
case BSSGP_PDUT_STATUS:
/* Some exception has occurred */
LOGP(DGPRS, LOGL_NOTICE,
"NSE(%05u/SGSN) BSSGP STATUS ", nsei);
if (!TLVP_PRES_LEN(&tp, BSSGP_IE_CAUSE, 1)) {
LOGPC(DGPRS, LOGL_NOTICE, "\n");
goto err_mand_ie;
}
cause = *TLVP_VAL(&tp, BSSGP_IE_CAUSE);
LOGPC(DGPRS, LOGL_NOTICE,
"cause=0x%02x(%s) ", *TLVP_VAL(&tp, BSSGP_IE_CAUSE),
bssgp_cause_str(cause));
if (TLVP_PRES_LEN(&tp, BSSGP_IE_BVCI, 2)) {
bvci = ntohs(tlvp_val16_unal(&tp, BSSGP_IE_BVCI));
LOGPC(DGPRS, LOGL_NOTICE, "BVCI=%05u\n", bvci);
if (cause == BSSGP_CAUSE_UNKNOWN_BVCI)
rc = gbprox_relay2bvci(cfg, msg, bvci, ns_bvci);
} else
LOGPC(DGPRS, LOGL_NOTICE, "\n");
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:
/* RAI IE is mandatory */
if (!TLVP_PRES_LEN(&tp, BSSGP_IE_ROUTEING_AREA, 6))
goto err_mand_ie;
bvc = gbproxy_bvc_by_rai(cfg, TLVP_VAL(&tp, BSSGP_IE_ROUTEING_AREA));
if (!bvc)
goto err_no_bvc;
rc = gbprox_relay2peer(msg, bvc, ns_bvci);
break;
case BSSGP_PDUT_BVC_BLOCK_ACK:
case BSSGP_PDUT_BVC_UNBLOCK_ACK:
if (!TLVP_PRES_LEN(&tp, BSSGP_IE_BVCI, 2))
goto err_mand_ie;
bvci = ntohs(tlvp_val16_unal(&tp, BSSGP_IE_BVCI));
if (bvci == 0) {
LOGP(DGPRS, LOGL_NOTICE, "NSE(%05u/SGSN) BSSGP "
"%sBLOCK_ACK for signalling BVCI ?!?\n", nsei,
pdu_type == BSSGP_PDUT_BVC_UNBLOCK_ACK ? "UN":"");
/* TODO: should we send STATUS ? */
rate_ctr_inc(&cfg->ctrg->
ctr[GBPROX_GLOB_CTR_INV_BVCI]);
} else {
/* Mark BVC as (un)blocked */
block_unblock_bvc(cfg, bvci, pdu_type);
}
rc = gbprox_relay2bvci(cfg, msg, bvci, ns_bvci);
break;
case BSSGP_PDUT_SGSN_INVOKE_TRACE:
case BSSGP_PDUT_OVERLOAD:
LOGP(DGPRS, LOGL_DEBUG,
"NSE(%05u/SGSN) BSSGP %s: broadcasting\n", nsei, bssgp_pdu_str(pdu_type));
/* broadcast to all BSS-side bvcs */
hash_for_each(cfg->bss_nses, i, nse, list) {
gbprox_relay2nse(msg, nse, 0);
}
break;
default:
LOGP(DGPRS, LOGL_NOTICE, "NSE(%05u/SGSN) BSSGP PDU type %s not supported\n", nsei,
bssgp_pdu_str(pdu_type));
rate_ctr_inc(&cfg->ctrg->
ctr[GBPROX_GLOB_CTR_PROTO_ERR_SGSN]);
rc = bssgp_tx_status(BSSGP_CAUSE_PROTO_ERR_UNSPEC, NULL, orig_msg);
break;
}
msgb_free(msg);
return rc;
err_mand_ie:
LOGP(DGPRS, LOGL_ERROR, "NSE(%05u/SGSN) missing mandatory IE\n",
nsei);
rate_ctr_inc(&cfg->ctrg->
ctr[GBPROX_GLOB_CTR_PROTO_ERR_SGSN]);
msgb_free(msg);
return bssgp_tx_status(BSSGP_CAUSE_MISSING_MAND_IE, NULL, orig_msg);
err_no_bvc:
LOGP(DGPRS, LOGL_ERROR, "NSE(%05u/SGSN) cannot find bvc based on RAI\n",
nsei);
rate_ctr_inc(&cfg->ctrg-> ctr[GBPROX_GLOB_CTR_INV_RAI]);
msgb_free(msg);
return bssgp_tx_status(BSSGP_CAUSE_INV_MAND_INF, NULL, orig_msg);
}
static int gbproxy_is_sgsn_nsei(struct gbproxy_config *cfg, uint16_t nsei)
{
return nsei == cfg->nsip_sgsn_nsei;
}
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, PRIM_NS_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)
{
int rc;
uint16_t nsei = msgb_nsei(msg);
uint16_t ns_bvci = msgb_bvci(msg);
struct gbproxy_config *cfg = (struct gbproxy_config *) ctx;
int remote_end_is_sgsn = gbproxy_is_sgsn_nsei(cfg, nsei);
/* Only BVCI=0 messages need special treatment */
if (ns_bvci == 0 || ns_bvci == 1) {
if (remote_end_is_sgsn)
rc = gbprox_rx_sig_from_sgsn(cfg, msg, nsei, ns_bvci);
else
rc = gbprox_rx_sig_from_bss(cfg, msg, nsei, ns_bvci);
} else {
/* All other BVCI are PTP */
if (remote_end_is_sgsn)
rc = gbprox_rx_ptp_from_sgsn(cfg, msg, nsei,
ns_bvci);
else
rc = gbprox_rx_ptp_from_bss(cfg, msg, nsei,
ns_bvci);
}
return rc;
}
/* TODO: What about handling:
* NS_AFF_CAUSE_VC_FAILURE,
NS_AFF_CAUSE_VC_RECOVERY,
NS_AFF_CAUSE_FAILURE,
NS_AFF_CAUSE_RECOVERY,
osmocom own causes
NS_AFF_CAUSE_SNS_CONFIGURED,
NS_AFF_CAUSE_SNS_FAILURE,
*/
void gprs_ns_prim_status_cb(struct gbproxy_config *cfg, struct osmo_gprs_ns2_prim *nsp)
{
/* TODO: bss nsei available/unavailable bssgp_tx_simple_bvci(BSSGP_PDUT_BVC_BLOCK, nsvc->nsei, bvc->bvci, 0);
* TODO: sgsn nsei available/unavailable
*/
struct gbproxy_bvc *bvc;
switch (nsp->u.status.cause) {
case NS_AFF_CAUSE_SNS_FAILURE:
case NS_AFF_CAUSE_SNS_CONFIGURED:
break;
case NS_AFF_CAUSE_RECOVERY:
LOGP(DPCU, LOGL_NOTICE, "NS-NSE %d became available\n", nsp->nsei);
if (nsp->nsei == cfg->nsip_sgsn_nsei) {
/* look-up or create the BTS context for this BVC */
struct bssgp_bvc_ctx *bctx = btsctx_by_bvci_nsei(nsp->bvci, nsp->nsei);
if (!bctx)
bctx = btsctx_alloc(nsp->bvci, nsp->nsei);
bssgp_tx_bvc_reset_nsei_bvci(cfg->nsip_sgsn_nsei, 0, BSSGP_CAUSE_OML_INTERV, NULL, 0);
}
break;
case NS_AFF_CAUSE_FAILURE:
if (nsp->nsei == cfg->nsip_sgsn_nsei) {
/* sgsn */
/* TODO: BSVC: block all PtP towards bss */
rate_ctr_inc(&cfg->ctrg->
ctr[GBPROX_GLOB_CTR_RESTART_RESET_SGSN]);
} else {
/* bss became unavailable
* TODO: Block all BVC belonging to that NSE */
bvc = gbproxy_bvc_by_nsei(cfg, nsp->nsei);
if (!bvc) {
/* TODO: use primitive name + status cause name */
LOGP(DGPRS, LOGL_NOTICE, "Received ns2 primitive %d for unknown bvc NSEI=%u\n",
nsp->u.status.cause, nsp->nsei);
break;
}
if (!bvc->blocked)
break;
bssgp_tx_simple_bvci(BSSGP_PDUT_BVC_BLOCK, cfg->nsip_sgsn_nsei,
bvc->bvci, 0);
}
LOGP(DPCU, LOGL_NOTICE, "NS-NSE %d became unavailable\n", nsp->nsei);
break;
default:
LOGP(DPCU, 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(DPCU, 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 PRIM_NS_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 PRIM_NS_STATUS:
gprs_ns_prim_status_cb(cfg, nsp);
break;
default:
LOGP(DPCU, 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);
}
rate_ctr_group_free(cfg->ctrg);
gbproxy_init_config(cfg);
}
int gbproxy_init_config(struct gbproxy_config *cfg)
{
struct timespec tp;
hash_init(cfg->bss_nses);
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);
return 0;
}
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