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osmo-msc/openbsc/src/gprs/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/talloc.h>
#include <osmocom/core/select.h>
#include <osmocom/core/rate_ctr.h>
#include <osmocom/gprs/gprs_ns.h>
#include <osmocom/gprs/gprs_bssgp.h>
#include <osmocom/gsm/gsm_utils.h>
#include <openbsc/signal.h>
#include <openbsc/debug.h>
#include <openbsc/gprs_gb_parse.h>
#include <openbsc/gb_proxy.h>
#include <openbsc/gprs_llc.h>
#include <openbsc/gsm_04_08.h>
#include <openbsc/gsm_04_08_gprs.h>
#include <openbsc/gprs_utils.h>
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,
};
static int check_peer_nsei(struct gbproxy_peer *peer, uint16_t nsei)
{
if (peer->nsei != nsei) {
LOGP(DGPRS, LOGL_NOTICE, "Peer entry doesn't match current NSEI "
"BVCI=%u via NSEI=%u (expected NSEI=%u)\n",
peer->bvci, nsei, peer->nsei);
rate_ctr_inc(&peer->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);
}
/* update peer according to the BSS message */
static void gbprox_update_current_raid(uint8_t *raid_enc,
struct gbproxy_peer *peer,
const char *log_text)
{
struct gbproxy_patch_state *state = &peer->patch_state;
const int old_local_mcc = state->local_mcc;
const int old_local_mnc = state->local_mnc;
struct gprs_ra_id raid;
if (!raid_enc)
return;
gsm48_parse_ra(&raid, raid_enc);
/* save source side MCC/MNC */
if (!peer->cfg->core_mcc || raid.mcc == peer->cfg->core_mcc) {
state->local_mcc = 0;
} else {
state->local_mcc = raid.mcc;
}
if (!peer->cfg->core_mnc || raid.mnc == peer->cfg->core_mnc) {
state->local_mnc = 0;
} else {
state->local_mnc = raid.mnc;
}
if (old_local_mcc != state->local_mcc ||
old_local_mnc != state->local_mnc)
LOGP(DGPRS, LOGL_NOTICE,
"Patching RAID %sactivated, msg: %s, "
"local: %d-%d, core: %d-%d\n",
state->local_mcc || state->local_mnc ?
"" : "de",
log_text,
state->local_mcc, state->local_mnc,
peer->cfg->core_mcc, peer->cfg->core_mnc);
}
uint32_t gbproxy_make_bss_ptmsi(struct gbproxy_peer *peer,
uint32_t sgsn_ptmsi)
{
uint32_t bss_ptmsi;
if (!peer->cfg->patch_ptmsi) {
bss_ptmsi = sgsn_ptmsi;
} else {
do {
bss_ptmsi = rand_r(&peer->cfg->bss_ptmsi_state);
bss_ptmsi = bss_ptmsi | 0xC0000000;
if (gbproxy_find_tlli_by_ptmsi(peer, bss_ptmsi))
bss_ptmsi = GSM_RESERVED_TMSI;
} while (bss_ptmsi == GSM_RESERVED_TMSI);
}
return bss_ptmsi;
}
uint32_t gbproxy_make_sgsn_tlli(struct gbproxy_peer *peer,
struct gbproxy_tlli_info *tlli_info,
uint32_t bss_tlli)
{
uint32_t sgsn_tlli;
if (!peer->cfg->patch_ptmsi) {
sgsn_tlli = bss_tlli;
} else if (tlli_info->sgsn_tlli.ptmsi != GSM_RESERVED_TMSI) {
sgsn_tlli = gprs_tmsi2tlli(tlli_info->sgsn_tlli.ptmsi,
TLLI_FOREIGN);
} else {
do {
/* create random TLLI, 0b01111xxx... */
sgsn_tlli = rand_r(&peer->cfg->sgsn_tlli_state);
sgsn_tlli = (sgsn_tlli & 0x7fffffff) | 0x78000000;
if (gbproxy_find_tlli_by_sgsn_tlli(peer, sgsn_tlli))
sgsn_tlli = 0;
} while (!sgsn_tlli);
}
return sgsn_tlli;
}
/* patch BSSGP message */
static void gbprox_process_bssgp_ul(struct gbproxy_config *cfg,
struct msgb *msg,
struct gbproxy_peer *peer)
{
struct gprs_gb_parse_context parse_ctx = {0};
int rc;
int len_change = 0;
time_t now;
struct gbproxy_tlli_info *tlli_info = NULL;
if (!cfg->core_mcc && !cfg->core_mnc && !cfg->core_apn)
return;
parse_ctx.to_bss = 0;
/* Parse BSSGP/LLC */
rc = gprs_gb_parse_bssgp(msgb_bssgph(msg), msgb_bssgp_len(msg),
&parse_ctx);
if (!rc) {
if (!parse_ctx.need_decryption) {
LOGP(DGPRS, LOGL_ERROR,
"NSEI=%u(BSS) patching: "
"failed to parse BSSGP/GMM message\n",
msgb_nsei(msg));
return;
}
}
/* Get peer */
if (!peer && msgb_bvci(msg) >= 2)
peer = gbproxy_peer_by_bvci(cfg, msgb_bvci(msg));
if (!peer)
peer = gbproxy_peer_by_nsei(cfg, msgb_nsei(msg));
if (!peer)
peer = gbproxy_peer_by_bssgp_tlv(cfg, &parse_ctx.bssgp_tp);
if (!peer) {
LOGP(DLLC, LOGL_INFO,
"NSEI=%d(BSS) patching: didn't find peer for message, "
"PDU %d\n",
msgb_nsei(msg), parse_ctx.pdu_type);
/* Increment counter */
rate_ctr_inc(&cfg->ctrg->ctr[GBPROX_GLOB_CTR_PATCH_PEER_ERR]);
return;
}
now = time(NULL);
if (parse_ctx.bssgp_raid_enc && parse_ctx.old_raid_enc &&
memcmp(parse_ctx.bssgp_raid_enc, parse_ctx.old_raid_enc, 6) == 0)
parse_ctx.old_raid_matches = 1;
gbprox_update_current_raid(parse_ctx.bssgp_raid_enc, peer,
parse_ctx.llc_msg_name);
if (parse_ctx.g48_hdr) {
switch (parse_ctx.g48_hdr->msg_type) {
case GSM48_MT_GMM_ATTACH_REQ:
rate_ctr_inc(&peer->ctrg->ctr[GBPROX_PEER_CTR_ATTACH_REQS]);
break;
default:
break;
}
}
gprs_gb_log_parse_context(&parse_ctx, "BSSGP");
tlli_info = gbproxy_update_tlli_state_ul(peer, now, &parse_ctx);
gbproxy_patch_bssgp(msg, msgb_bssgph(msg), msgb_bssgp_len(msg),
peer, tlli_info, &len_change, &parse_ctx);
gbproxy_update_tlli_state_after(peer, tlli_info, now, &parse_ctx);
return;
}
/* patch BSSGP message to use core_mcc/mnc on the SGSN side */
static void gbprox_process_bssgp_dl(struct gbproxy_config *cfg,
struct msgb *msg,
struct gbproxy_peer *peer)
{
struct gprs_gb_parse_context parse_ctx = {0};
int rc;
int len_change = 0;
time_t now;
struct gbproxy_tlli_info *tlli_info = NULL;
parse_ctx.to_bss = 1;
rc = gprs_gb_parse_bssgp(msgb_bssgph(msg), msgb_bssgp_len(msg),
&parse_ctx);
if (!rc) {
if (!parse_ctx.need_decryption) {
LOGP(DGPRS, LOGL_ERROR,
"NSEI=%u(SGSN) patching: "
"failed to parse BSSGP/GMM message\n",
msgb_nsei(msg));
return;
}
}
if (!peer && msgb_bvci(msg) >= 2)
peer = gbproxy_peer_by_bvci(cfg, msgb_bvci(msg));
if (!peer)
peer = gbproxy_peer_by_bssgp_tlv(cfg, &parse_ctx.bssgp_tp);
if (!peer) {
LOGP(DLLC, LOGL_INFO,
"NSEI=%d(SGSN) patching: didn't find peer for message, "
"PDU %d\n",
msgb_nsei(msg), parse_ctx.pdu_type);
/* Increment counter */
rate_ctr_inc(&cfg->ctrg->ctr[GBPROX_GLOB_CTR_PATCH_PEER_ERR]);
return;
}
now = time(NULL);
if (parse_ctx.g48_hdr) {
switch (parse_ctx.g48_hdr->msg_type) {
case GSM48_MT_GMM_ATTACH_REJ:
rate_ctr_inc(&peer->ctrg->ctr[GBPROX_PEER_CTR_ATTACH_REJS]);
break;
default:
break;
}
}
gprs_gb_log_parse_context(&parse_ctx, "BSSGP");
tlli_info = gbproxy_update_tlli_state_dl(peer, now, &parse_ctx);
gbproxy_patch_bssgp(msg, msgb_bssgph(msg), msgb_bssgp_len(msg),
peer, tlli_info, &len_change, &parse_ctx);
gbproxy_update_tlli_state_after(peer, tlli_info, now, &parse_ctx);
return;
}
/* feed a message down the NS-VC associated with the specified peer */
static int gbprox_relay2sgsn(struct gbproxy_config *cfg, struct msgb *old_msg,
uint16_t ns_bvci)
{
/* create a copy of the message so the old one can
* be free()d safely when we return from gbprox_rcvmsg() */
struct msgb *msg = gprs_msgb_copy(old_msg, "msgb_relay2sgsn");
int rc;
DEBUGP(DGPRS, "NSEI=%u proxying BTS->SGSN (NS_BVCI=%u, NSEI=%u)\n",
msgb_nsei(msg), ns_bvci, cfg->nsip_sgsn_nsei);
msgb_bvci(msg) = ns_bvci;
msgb_nsei(msg) = cfg->nsip_sgsn_nsei;
strip_ns_hdr(msg);
rc = gprs_ns_sendmsg(bssgp_nsi, msg);
if (rc < 0)
rate_ctr_inc(&cfg->ctrg->ctr[GBPROX_GLOB_CTR_TX_ERR_SGSN]);
return rc;
}
/* feed a message down the NS-VC associated with the specified peer */
static int gbprox_relay2peer(struct msgb *old_msg, struct gbproxy_peer *peer,
uint16_t ns_bvci)
{
/* create a copy of the message so the old one can
* be free()d safely when we return from gbprox_rcvmsg() */
struct msgb *msg = gprs_msgb_copy(old_msg, "msgb_relay2peer");
int rc;
DEBUGP(DGPRS, "NSEI=%u proxying SGSN->BSS (NS_BVCI=%u, NSEI=%u)\n",
msgb_nsei(msg), ns_bvci, peer->nsei);
msgb_bvci(msg) = ns_bvci;
msgb_nsei(msg) = peer->nsei;
/* Strip the old NS header, it will be replaced with a new one */
strip_ns_hdr(msg);
rc = gprs_ns_sendmsg(bssgp_nsi, msg);
if (rc < 0)
rate_ctr_inc(&peer->ctrg->ctr[GBPROX_PEER_CTR_TX_ERR]);
return rc;
}
static int block_unblock_peer(struct gbproxy_config *cfg, uint16_t ptp_bvci, uint8_t pdu_type)
{
struct gbproxy_peer *peer;
peer = gbproxy_peer_by_bvci(cfg, ptp_bvci);
if (!peer) {
LOGP(DGPRS, LOGL_ERROR, "BVCI=%u: 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:
peer->blocked = 1;
rate_ctr_inc(&peer->ctrg->ctr[GBPROX_PEER_CTR_BLOCKED]);
break;
case BSSGP_PDUT_BVC_UNBLOCK_ACK:
peer->blocked = 0;
rate_ctr_inc(&peer->ctrg->ctr[GBPROX_PEER_CTR_UNBLOCKED]);
break;
default:
break;
}
return 0;
}
/* Send a message to a peer 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_peer *peer;
peer = gbproxy_peer_by_bvci(cfg, ptp_bvci);
if (!peer) {
LOGP(DGPRS, LOGL_ERROR, "BVCI=%u: Cannot find BSS\n",
ptp_bvci);
rate_ctr_inc(&cfg->ctrg->ctr[GBPROX_GLOB_CTR_INV_BVCI]);
return -ENOENT;
}
return gbprox_relay2peer(msg, peer, 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 nsvci, uint16_t ns_bvci)
{
struct gbproxy_peer *peer;
peer = gbproxy_peer_by_bvci(cfg, ns_bvci);
if (peer)
check_peer_nsei(peer, nsei);
gbprox_process_bssgp_ul(cfg, msg, peer);
return gbprox_relay2sgsn(cfg, msg, ns_bvci);
}
/* 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 nsvci, uint16_t ns_bvci)
{
struct gbproxy_peer *peer;
peer = gbproxy_peer_by_bvci(cfg, ns_bvci);
/* Send status messages before patching */
if (!peer) {
LOGP(DGPRS, LOGL_INFO, "Didn't find peer for "
"BVCI=%u for message from NSVC=%u/NSEI=%u (SGSN)\n",
ns_bvci, nsvci, nsei);
rate_ctr_inc(&cfg->ctrg->
ctr[GBPROX_GLOB_CTR_INV_BVCI]);
return bssgp_tx_status(BSSGP_CAUSE_UNKNOWN_BVCI,
&ns_bvci, msg);
}
if (peer->blocked) {
LOGP(DGPRS, LOGL_NOTICE, "Dropping PDU for "
"blocked BVCI=%u via NSVC=%u/NSEI=%u\n",
ns_bvci, nsvci, nsei);
rate_ctr_inc(&peer->ctrg->ctr[GBPROX_PEER_CTR_DROPPED]);
return bssgp_tx_status(BSSGP_CAUSE_BVCI_BLOCKED, NULL, msg);
}
/* Optionally patch the message */
gbprox_process_bssgp_dl(cfg, msg, peer);
return gbprox_relay2peer(msg, peer, ns_bvci);
}
/* 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_peer *from_peer = NULL;
struct gprs_ra_id raid;
if (ns_bvci != 0 && ns_bvci != 1) {
LOGP(DGPRS, LOGL_NOTICE, "NSEI=%u BVCI=%u 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, "NSEI=%u 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/peer 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_PRESENT(&tp, BSSGP_IE_ROUTEING_AREA))
goto err_mand_ie;
from_peer = gbproxy_peer_by_nsei(cfg, nsei);
if (!from_peer)
goto err_no_peer;
memcpy(from_peer->ra, TLVP_VAL(&tp, BSSGP_IE_ROUTEING_AREA),
sizeof(from_peer->ra));
gsm48_parse_ra(&raid, from_peer->ra);
LOGP(DGPRS, LOGL_INFO, "NSEI=%u BSSGP SUSPEND/RESUME "
"RAI snooping: RAI %u-%u-%u-%u behind BVCI=%u\n",
nsei, raid.mcc, raid.mnc, raid.lac,
raid.rac , from_peer->bvci);
/* FIXME: This only supports one BSS per RA */
break;
case BSSGP_PDUT_BVC_RESET:
/* 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) */
if (TLVP_PRESENT(&tp, BSSGP_IE_BVCI)) {
uint16_t bvci = ntohs(tlvp_val16_unal(&tp, BSSGP_IE_BVCI));
LOGP(DGPRS, LOGL_INFO, "NSEI=%u Rx BVC RESET (BVCI=%u)\n",
nsei, bvci);
if (bvci == 0) {
/* FIXME: only do this if SGSN is alive! */
LOGP(DGPRS, LOGL_INFO, "NSEI=%u Tx fake "
"BVC RESET ACK of BVCI=0\n", nsei);
return bssgp_tx_simple_bvci(BSSGP_PDUT_BVC_RESET_ACK,
nsei, 0, ns_bvci);
}
from_peer = gbproxy_peer_by_bvci(cfg, bvci);
if (!from_peer) {
/* if a PTP-BVC is reset, and we don't know that
* PTP-BVCI yet, we should allocate a new peer */
LOGP(DGPRS, LOGL_INFO, "Allocationg new peer for "
"BVCI=%u via NSEI=%u\n", bvci, nsei);
from_peer = gbproxy_peer_alloc(cfg, bvci);
from_peer->nsei = nsei;
}
if (!check_peer_nsei(from_peer, nsei))
from_peer->nsei = nsei;
if (TLVP_PRESENT(&tp, BSSGP_IE_CELL_ID)) {
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_peer->ra,
TLVP_VAL(&tp, BSSGP_IE_CELL_ID),
sizeof(from_peer->ra));
gsm48_parse_ra(&raid, from_peer->ra);
LOGP(DGPRS, LOGL_INFO, "NSEI=%u/BVCI=%u "
"Cell ID %u-%u-%u-%u\n", nsei,
bvci, raid.mcc, raid.mnc, raid.lac,
raid.rac);
}
}
break;
}
/* Normally, we can simply pass on all signalling messages from BSS to
* SGSN */
gbprox_process_bssgp_ul(cfg, msg, from_peer);
return gbprox_relay2sgsn(cfg, msg, ns_bvci);
err_no_peer:
LOGP(DGPRS, LOGL_ERROR, "NSEI=%u(BSS) cannot find peer based on NSEI\n",
nsei);
rate_ctr_inc(&cfg->ctrg->ctr[GBPROX_GLOB_CTR_INV_NSEI]);
return bssgp_tx_status(BSSGP_CAUSE_UNKNOWN_BVCI, NULL, msg);
err_mand_ie:
LOGP(DGPRS, LOGL_ERROR, "NSEI=%u(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_peer *peer = NULL;
int errctr = GBPROX_GLOB_CTR_PROTO_ERR_SGSN;
LOGP(DGPRS, LOGL_INFO, "NSEI=%u(SGSN) BSSGP PAGING ",
nsei);
if (TLVP_PRESENT(tp, BSSGP_IE_BVCI)) {
uint16_t bvci = ntohs(tlvp_val16_unal(tp, BSSGP_IE_BVCI));
LOGPC(DGPRS, LOGL_INFO, "routing by BVCI to peer BVCI=%u\n",
bvci);
errctr = GBPROX_GLOB_CTR_OTHER_ERR;
} else if (TLVP_PRESENT(tp, BSSGP_IE_ROUTEING_AREA)) {
peer = gbproxy_peer_by_rai(cfg, TLVP_VAL(tp, BSSGP_IE_ROUTEING_AREA));
LOGPC(DGPRS, LOGL_INFO, "routing by RAI to peer BVCI=%u\n",
peer ? peer->bvci : -1);
errctr = GBPROX_GLOB_CTR_INV_RAI;
} else if (TLVP_PRESENT(tp, BSSGP_IE_LOCATION_AREA)) {
peer = gbproxy_peer_by_lai(cfg, TLVP_VAL(tp, BSSGP_IE_LOCATION_AREA));
LOGPC(DGPRS, LOGL_INFO, "routing by LAI to peer BVCI=%u\n",
peer ? peer->bvci : -1);
errctr = GBPROX_GLOB_CTR_INV_LAI;
} else
LOGPC(DGPRS, LOGL_INFO, "\n");
if (!peer) {
LOGP(DGPRS, LOGL_ERROR, "NSEI=%u(SGSN) BSSGP PAGING: "
"unable to route, missing IE\n", nsei);
rate_ctr_inc(&cfg->ctrg->ctr[errctr]);
return -EINVAL;
}
return gbprox_relay2peer(msg, peer, ns_bvci);
}
/* 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_peer *peer;
uint16_t ptp_bvci;
if (!TLVP_PRESENT(tp, BSSGP_IE_BVCI)) {
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 peer */
peer = gbproxy_peer_by_bvci(cfg, ptp_bvci);
if (!peer) {
LOGP(DGPRS, LOGL_ERROR, "NSEI=%u BVCI=%u: 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,
NULL, orig_msg);
}
return gbprox_relay2peer(msg, peer, 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 */
llist_for_each_entry(peer, &cfg->bts_peers, list)
gbprox_relay2peer(msg, peer, 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_peer *peer;
uint16_t bvci;
struct msgb *msg;
int rc = 0;
if (ns_bvci != 0 && ns_bvci != 1) {
LOGP(DGPRS, LOGL_NOTICE, "NSEI=%u(SGSN) BVCI=%u 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, "NSEI=%u(SGSN) UNITDATA not allowed in "
"signalling\n", nsei);
return bssgp_tx_status(BSSGP_CAUSE_PROTO_ERR_UNSPEC, NULL, orig_msg);
}
msg = gprs_msgb_copy(orig_msg, "rx_sig_from_sgsn");
gbprox_process_bssgp_dl(cfg, msg, NULL);
/* 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_FLUSH_LL:
case BSSGP_PDUT_BVC_RESET_ACK:
/* simple case: BVCI IE is mandatory */
if (!TLVP_PRESENT(&tp, BSSGP_IE_BVCI))
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,
"NSEI=%u(SGSN) BSSGP STATUS ", nsei);
if (!TLVP_PRESENT(&tp, BSSGP_IE_CAUSE)) {
LOGPC(DGPRS, LOGL_NOTICE, "\n");
goto err_mand_ie;
}
LOGPC(DGPRS, LOGL_NOTICE,
"cause=0x%02x(%s) ", *TLVP_VAL(&tp, BSSGP_IE_CAUSE),
bssgp_cause_str(*TLVP_VAL(&tp, BSSGP_IE_CAUSE)));
if (TLVP_PRESENT(&tp, BSSGP_IE_BVCI)) {
uint16_t bvci = tlvp_val16_unal(&tp, BSSGP_IE_BVCI);
LOGPC(DGPRS, LOGL_NOTICE,
"BVCI=%u\n", ntohs(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_PRESENT(&tp, BSSGP_IE_ROUTEING_AREA))
goto err_mand_ie;
peer = gbproxy_peer_by_rai(cfg, TLVP_VAL(&tp, BSSGP_IE_ROUTEING_AREA));
if (!peer)
goto err_no_peer;
rc = gbprox_relay2peer(msg, peer, ns_bvci);
break;
case BSSGP_PDUT_BVC_BLOCK_ACK:
case BSSGP_PDUT_BVC_UNBLOCK_ACK:
if (!TLVP_PRESENT(&tp, BSSGP_IE_BVCI))
goto err_mand_ie;
bvci = ntohs(tlvp_val16_unal(&tp, BSSGP_IE_BVCI));
if (bvci == 0) {
LOGP(DGPRS, LOGL_NOTICE, "NSEI=%u(SGSN) BSSGP "
"%sBLOCK_ACK for signalling BVCI ?!?\n", nsei,
pdu_type == BSSGP_PDUT_BVC_UNBLOCK_ACK ? "UN":"");
/* should we send STATUS ? */
rate_ctr_inc(&cfg->ctrg->
ctr[GBPROX_GLOB_CTR_INV_BVCI]);
} else {
/* Mark BVC as (un)blocked */
block_unblock_peer(cfg, bvci, pdu_type);
}
rc = gbprox_relay2bvci(cfg, msg, bvci, ns_bvci);
break;
case BSSGP_PDUT_SGSN_INVOKE_TRACE:
LOGP(DGPRS, LOGL_ERROR,
"NSEI=%u(SGSN) BSSGP INVOKE TRACE not supported\n",nsei);
rate_ctr_inc(&cfg->ctrg->
ctr[GBPROX_GLOB_CTR_NOT_SUPPORTED_SGSN]);
rc = bssgp_tx_status(BSSGP_CAUSE_PDU_INCOMP_FEAT, NULL, orig_msg);
break;
default:
LOGP(DGPRS, LOGL_NOTICE, "BSSGP PDU type 0x%02x unknown\n",
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, "NSEI=%u(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_peer:
LOGP(DGPRS, LOGL_ERROR, "NSEI=%u(SGSN) cannot find peer 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_UNKNOWN_BVCI, NULL, orig_msg);
}
/* Main input function for Gb proxy */
int gbprox_rcvmsg(struct gbproxy_config *cfg, struct msgb *msg, uint16_t nsei,
uint16_t ns_bvci, uint16_t nsvci)
{
int rc;
int remote_end_is_sgsn = nsei == cfg->nsip_sgsn_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, nsvci,
ns_bvci);
else
rc = gbprox_rx_ptp_from_bss(cfg, msg, nsei, nsvci,
ns_bvci);
}
return rc;
}
int gbprox_reset_persistent_nsvcs(struct gprs_ns_inst *nsi)
{
struct gprs_nsvc *nsvc;
llist_for_each_entry(nsvc, &nsi->gprs_nsvcs, list) {
if (!nsvc->persistent)
continue;
gprs_nsvc_reset(nsvc, NS_CAUSE_OM_INTERVENTION);
}
return 0;
}
/* Signal handler for signals from NS layer */
int gbprox_signal(unsigned int subsys, unsigned int signal,
void *handler_data, void *signal_data)
{
struct gbproxy_config *cfg = handler_data;
struct ns_signal_data *nssd = signal_data;
struct gprs_nsvc *nsvc = nssd->nsvc;
struct gbproxy_peer *peer;
if (subsys != SS_L_NS)
return 0;
if (signal == S_NS_RESET && nsvc->nsei == cfg->nsip_sgsn_nsei) {
/* We have received a NS-RESET from the NSEI and NSVC
* of the SGSN. This might happen with SGSN that start
* their own NS-RESET procedure without waiting for our
* NS-RESET */
nsvc->remote_end_is_sgsn = 1;
}
if (signal == S_NS_ALIVE_EXP && nsvc->remote_end_is_sgsn) {
LOGP(DGPRS, LOGL_NOTICE, "Tns alive expired too often, "
"re-starting RESET procedure\n");
rate_ctr_inc(&cfg->ctrg->
ctr[GBPROX_GLOB_CTR_RESTART_RESET_SGSN]);
gprs_ns_nsip_connect(nsvc->nsi, &nsvc->ip.bts_addr,
nsvc->nsei, nsvc->nsvci);
}
if (!nsvc->remote_end_is_sgsn) {
/* from BSS to SGSN */
peer = gbproxy_peer_by_nsei(cfg, nsvc->nsei);
if (!peer) {
LOGP(DGPRS, LOGL_NOTICE, "signal %u for unknown peer "
"NSEI=%u/NSVCI=%u\n", signal, nsvc->nsei,
nsvc->nsvci);
return 0;
}
switch (signal) {
case S_NS_RESET:
case S_NS_BLOCK:
if (!peer->blocked)
break;
LOGP(DGPRS, LOGL_NOTICE, "Converting NS_RESET from "
"NSEI=%u/NSVCI=%u into BSSGP_BVC_BLOCK to SGSN\n",
nsvc->nsei, nsvc->nsvci);
bssgp_tx_simple_bvci(BSSGP_PDUT_BVC_BLOCK, nsvc->nsei,
peer->bvci, 0);
break;
}
} else {
/* Forward this message to all NS-VC to BSS */
struct gprs_ns_inst *nsi = cfg->nsi;
struct gprs_nsvc *next_nsvc;
llist_for_each_entry(next_nsvc, &nsi->gprs_nsvcs, list) {
if (next_nsvc->remote_end_is_sgsn)
continue;
/* Note that the following does not start the full
* procedures including timer based retransmissions. */
switch (signal) {
case S_NS_RESET:
gprs_ns_tx_reset(next_nsvc, nssd->cause);
break;
case S_NS_BLOCK:
gprs_ns_tx_block(next_nsvc, nssd->cause);
break;
case S_NS_UNBLOCK:
gprs_ns_tx_unblock(next_nsvc);
break;
}
}
}
return 0;
}
void gbprox_reset(struct gbproxy_config *cfg)
{
struct gbproxy_peer *peer, *tmp;
llist_for_each_entry_safe(peer, tmp, &cfg->bts_peers, list)
gbproxy_peer_free(peer);
rate_ctr_group_free(cfg->ctrg);
gbproxy_init_config(cfg);
}
int gbproxy_init_config(struct gbproxy_config *cfg)
{
struct timespec tp;
INIT_LLIST_HEAD(&cfg->bts_peers);
cfg->ctrg = rate_ctr_group_alloc(tall_bsc_ctx, &global_ctrg_desc, 0);
clock_gettime(CLOCK_REALTIME, &tp);
cfg->bss_ptmsi_state = tp.tv_sec + tp.tv_nsec;
cfg->sgsn_tlli_state = tp.tv_sec - tp.tv_nsec;
return 0;
}
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