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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/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>
enum gbprox_global_ctr {
GBPROX_GLOB_CTR_INV_BVCI,
GBPROX_GLOB_CTR_INV_LAI,
GBPROX_GLOB_CTR_INV_RAI,
GBPROX_GLOB_CTR_INV_NSEI,
GBPROX_GLOB_CTR_PROTO_ERR_BSS,
GBPROX_GLOB_CTR_PROTO_ERR_SGSN,
GBPROX_GLOB_CTR_NOT_SUPPORTED_BSS,
GBPROX_GLOB_CTR_NOT_SUPPORTED_SGSN,
GBPROX_GLOB_CTR_RESTART_RESET_SGSN,
GBPROX_GLOB_CTR_TX_ERR_SGSN,
GBPROX_GLOB_CTR_OTHER_ERR,
GBPROX_GLOB_CTR_PATCH_PEER_ERR,
};
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,
};
enum gbprox_peer_ctr {
GBPROX_PEER_CTR_BLOCKED,
GBPROX_PEER_CTR_UNBLOCKED,
GBPROX_PEER_CTR_DROPPED,
GBPROX_PEER_CTR_INV_NSEI,
GBPROX_PEER_CTR_TX_ERR,
GBPROX_PEER_CTR_RAID_PATCHED_BSS,
GBPROX_PEER_CTR_RAID_PATCHED_SGSN,
GBPROX_PEER_CTR_APN_PATCHED,
GBPROX_PEER_CTR_PATCH_CRYPT_ERR,
GBPROX_PEER_CTR_PATCH_ERR,
GBPROX_PEER_CTR_ATTACH_REQS,
GBPROX_PEER_CTR_ATTACH_REJS,
GBPROX_PEER_CTR_TLLI_CACHE_SIZE,
};
static const struct rate_ctr_desc peer_ctr_description[] = {
{ "blocked", "BVC Block " },
{ "unblocked", "BVC Unblock " },
{ "dropped", "BVC blocked, dropped packet " },
{ "inv-nsei", "NSEI mismatch " },
{ "tx-err", "NS Transmission error " },
{ "raid-mod.bss", "RAID patched (BSS )" },
{ "raid-mod.sgsn", "RAID patched (SGSN)" },
{ "apn-mod.sgsn", "APN patched " },
{ "mod-crypt-err", "Patch error: encrypted " },
{ "mod-err", "Patch error: other " },
{ "attach-reqs", "Attach Request count " },
{ "attach-rejs", "Attach Reject count " },
{ "tlli-cache", "TLLI cache size " },
};
static const struct rate_ctr_group_desc peer_ctrg_desc = {
.group_name_prefix = "gbproxy.peer",
.group_description = "GBProxy Peer Statistics",
.num_ctr = ARRAY_SIZE(peer_ctr_description),
.ctr_desc = peer_ctr_description,
};
static void gbprox_delete_tllis(struct gbproxy_peer *peer);
/* Find the gbprox_peer by its BVCI */
static struct gbproxy_peer *peer_by_bvci(struct gbproxy_config *cfg, uint16_t bvci)
{
struct gbproxy_peer *peer;
llist_for_each_entry(peer, &cfg->bts_peers, list) {
if (peer->bvci == bvci)
return peer;
}
return NULL;
}
/* Find the gbprox_peer by its NSEI */
struct gbproxy_peer *gbprox_peer_by_nsei(struct gbproxy_config *cfg, uint16_t nsei)
{
struct gbproxy_peer *peer;
llist_for_each_entry(peer, &cfg->bts_peers, list) {
if (peer->nsei == nsei)
return peer;
}
return NULL;
}
/* look-up a peer by its Routeing Area Identification (RAI) */
static struct gbproxy_peer *peer_by_rai(struct gbproxy_config *cfg, const uint8_t *ra)
{
struct gbproxy_peer *peer;
llist_for_each_entry(peer, &cfg->bts_peers, list) {
if (!memcmp(peer->ra, ra, 6))
return peer;
}
return NULL;
}
/* look-up a peer by its Location Area Identification (LAI) */
static struct gbproxy_peer *peer_by_lai(struct gbproxy_config *cfg, const uint8_t *la)
{
struct gbproxy_peer *peer;
llist_for_each_entry(peer, &cfg->bts_peers, list) {
if (!memcmp(peer->ra, la, 5))
return peer;
}
return NULL;
}
/* look-up a peer by its Location Area Code (LAC) */
static struct gbproxy_peer *peer_by_lac(struct gbproxy_config *cfg, const uint8_t *la)
{
struct gbproxy_peer *peer;
llist_for_each_entry(peer, &cfg->bts_peers, list) {
if (!memcmp(peer->ra + 3, la + 3, 2))
return peer;
}
return NULL;
}
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;
}
struct gbproxy_peer *gbproxy_peer_alloc(struct gbproxy_config *cfg, uint16_t bvci)
{
struct gbproxy_peer *peer;
peer = talloc_zero(tall_bsc_ctx, struct gbproxy_peer);
if (!peer)
return NULL;
peer->bvci = bvci;
peer->ctrg = rate_ctr_group_alloc(peer, &peer_ctrg_desc, bvci);
peer->cfg = cfg;
llist_add(&peer->list, &cfg->bts_peers);
INIT_LLIST_HEAD(&peer->patch_state.enabled_tllis);
return peer;
}
void gbproxy_peer_free(struct gbproxy_peer *peer)
{
llist_del(&peer->list);
gbprox_delete_tllis(peer);
rate_ctr_group_free(peer->ctrg);
peer->ctrg = NULL;
talloc_free(peer);
}
/* 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);
}
/* TODO: Move shift functions to libosmocore */
int v_fixed_shift(uint8_t **data, size_t *data_len,
size_t len, uint8_t **value)
{
if (len > *data_len)
goto fail;
if (value)
*value = *data;
*data += len;
*data_len -= len;
return len;
fail:
*data += *data_len;
*data_len = 0;
return -1;
}
int tv_fixed_match(uint8_t **data, size_t *data_len,
uint8_t tag, size_t len,
uint8_t **value)
{
size_t ie_len;
if (*data_len == 0)
goto fail;
if ((*data)[0] != tag)
return 0;
if (len > *data_len - 1)
goto fail;
if (value)
*value = *data + 1;
ie_len = len + 1;
*data += ie_len;
*data_len -= ie_len;
return ie_len;
fail:
*data += *data_len;
*data_len = 0;
return -1;
}
int tlv_match(uint8_t **data, size_t *data_len,
uint8_t tag, uint8_t **value, size_t *value_len)
{
size_t len;
size_t ie_len;
if (*data_len < 2)
goto fail;
if ((*data)[0] != tag)
return 0;
len = (*data)[1];
if (len > *data_len - 2)
goto fail;
if (value)
*value = *data + 2;
if (value_len)
*value_len = len;
ie_len = len + 2;
*data += ie_len;
*data_len -= ie_len;
return ie_len;
fail:
*data += *data_len;
*data_len = 0;
return -1;
}
int lv_shift(uint8_t **data, size_t *data_len,
uint8_t **value, size_t *value_len)
{
size_t len;
size_t ie_len;
if (*data_len < 1)
goto fail;
len = (*data)[0];
if (len > *data_len - 1)
goto fail;
if (value)
*value = *data + 1;
if (value_len)
*value_len = len;
ie_len = len + 1;
*data += ie_len;
*data_len -= ie_len;
return ie_len;
fail:
*data += *data_len;
*data_len = 0;
return -1;
}
/* GSM 04.08, 10.5.1.4 */
static int is_mi_tmsi(const uint8_t *value, size_t value_len)
{
if (value_len != GSM48_TMSI_LEN)
return 0;
if (!value || (value[0] & GSM_MI_TYPE_MASK) != GSM_MI_TYPE_TMSI)
return 0;
return 1;
}
/* GSM 04.08, 10.5.1.4 */
static int is_mi_imsi(const uint8_t *value, size_t value_len)
{
if (value_len == 0)
return 0;
if (!value || (value[0] & GSM_MI_TYPE_MASK) != GSM_MI_TYPE_IMSI)
return 0;
return 1;
}
static int parse_mi_tmsi(const uint8_t *value, size_t value_len, uint32_t *tmsi)
{
uint32_t tmsi_be;
if (!is_mi_tmsi(value, value_len))
return 0;
memcpy(&tmsi_be, value + 1, sizeof(tmsi_be));
*tmsi = ntohl(tmsi_be);
return 1;
}
struct gbproxy_parse_context {
/* Pointer to protocol specific parts */
struct gsm48_hdr *g48_hdr;
struct bssgp_normal_hdr *bgp_hdr;
struct bssgp_ud_hdr *bud_hdr;
uint8_t *bssgp_data;
size_t bssgp_data_len;
uint8_t *llc;
size_t llc_len;
/* Extracted information */
struct gprs_llc_hdr_parsed llc_hdr_parsed;
struct tlv_parsed bssgp_tp;
int to_bss;
uint8_t *tlli_enc;
uint8_t *imsi;
size_t imsi_len;
uint8_t *apn_ie;
size_t apn_ie_len;
uint8_t *ptmsi_enc;
uint8_t *new_ptmsi_enc;
uint8_t *raid_enc;
uint8_t *bssgp_raid_enc;
uint8_t *bssgp_ptimsi;
/* General info */
const char *llc_msg_name;
int invalidate_tlli;
int need_decryption;
uint32_t tlli;
int pdu_type;
};
static struct gbproxy_tlli_info *gbprox_find_tlli(struct gbproxy_peer *peer,
uint32_t tlli)
{
struct gbproxy_tlli_info *tlli_info;
struct gbproxy_patch_state *state = &peer->patch_state;
llist_for_each_entry(tlli_info, &state->enabled_tllis, list)
if (tlli_info->tlli == tlli)
return tlli_info;
return NULL;
}
struct gbproxy_tlli_info *gbprox_find_tlli_by_mi(
struct gbproxy_peer *peer,
const uint8_t *mi_data,
size_t mi_data_len)
{
struct gbproxy_tlli_info *tlli_info;
struct gbproxy_patch_state *state = &peer->patch_state;
if (!is_mi_imsi(mi_data, mi_data_len))
return NULL;
llist_for_each_entry(tlli_info, &state->enabled_tllis, list) {
if (tlli_info->mi_data_len != mi_data_len)
continue;
if (memcmp(tlli_info->mi_data, mi_data, mi_data_len) != 0)
continue;
return tlli_info;
}
return NULL;
}
void gbprox_delete_tlli(struct gbproxy_peer *peer,
struct gbproxy_tlli_info *tlli_info)
{
struct gbproxy_patch_state *state = &peer->patch_state;
llist_del(&tlli_info->list);
talloc_free(tlli_info);
state->enabled_tllis_count -= 1;
peer->ctrg->ctr[GBPROX_PEER_CTR_TLLI_CACHE_SIZE].current =
state->enabled_tllis_count;
}
static void gbprox_delete_tllis(struct gbproxy_peer *peer)
{
struct gbproxy_tlli_info *tlli_info, *nxt;
struct gbproxy_patch_state *state = &peer->patch_state;
llist_for_each_entry_safe(tlli_info, nxt, &state->enabled_tllis, list)
gbprox_delete_tlli(peer, tlli_info);
OSMO_ASSERT(state->enabled_tllis_count == 0);
OSMO_ASSERT(llist_empty(&state->enabled_tllis));
}
void gbprox_clear_patch_filter(struct gbproxy_config *cfg)
{
if (cfg->check_imsi) {
regfree(&cfg->imsi_re_comp);
cfg->check_imsi = 0;
}
}
int gbprox_set_patch_filter(struct gbproxy_config *cfg, const char *filter,
const char **err_msg)
{
static char err_buf[300];
int rc;
gbprox_clear_patch_filter(cfg);
if (!filter)
return 0;
rc = regcomp(&cfg->imsi_re_comp, filter,
REG_EXTENDED | REG_NOSUB | REG_ICASE);
if (rc == 0) {
cfg->check_imsi = 1;
return 0;
}
if (err_msg) {
regerror(rc, &cfg->imsi_re_comp,
err_buf, sizeof(err_buf));
*err_msg = err_buf;
}
return -1;
}
int gbprox_check_imsi(struct gbproxy_peer *peer,
const uint8_t *imsi, size_t imsi_len)
{
char mi_buf[200];
int rc;
if (!peer->cfg->check_imsi)
return 1;
rc = is_mi_imsi(imsi, imsi_len);
if (rc > 0)
rc = gsm48_mi_to_string(mi_buf, sizeof(mi_buf), imsi, imsi_len);
if (rc <= 0) {
LOGP(DGPRS, LOGL_NOTICE, "Invalid IMSI %s\n",
osmo_hexdump(imsi, imsi_len));
return -1;
}
LOGP(DGPRS, LOGL_DEBUG, "Checking IMSI '%s' (%d)\n", mi_buf, rc);
rc = regexec(&peer->cfg->imsi_re_comp, mi_buf, 0, NULL, 0);
if (rc == REG_NOMATCH) {
LOGP(DGPRS, LOGL_INFO,
"IMSI '%s' doesn't match pattern '%s'\n",
mi_buf, peer->cfg->match_re);
return 0;
}
return 1;
}
static void gbprox_attach_tlli_info(struct gbproxy_peer *peer, time_t now,
struct gbproxy_tlli_info *tlli_info)
{
struct gbproxy_patch_state *state = &peer->patch_state;
tlli_info->timestamp = now;
llist_add(&tlli_info->list, &state->enabled_tllis);
state->enabled_tllis_count += 1;
peer->ctrg->ctr[GBPROX_PEER_CTR_TLLI_CACHE_SIZE].current =
state->enabled_tllis_count;
}
int gbprox_remove_stale_tllis(struct gbproxy_peer *peer, time_t now)
{
struct gbproxy_patch_state *state = &peer->patch_state;
int exceeded_max_len = 0;
int deleted_count = 0;
int check_for_age;
if (peer->cfg->tlli_max_len > 0)
exceeded_max_len =
state->enabled_tllis_count - peer->cfg->tlli_max_len;
check_for_age = peer->cfg->tlli_max_age > 0;
for (; exceeded_max_len > 0; exceeded_max_len--) {
struct gbproxy_tlli_info *tlli_info;
OSMO_ASSERT(!llist_empty(&state->enabled_tllis));
tlli_info = llist_entry(state->enabled_tllis.prev,
struct gbproxy_tlli_info,
list);
LOGP(DGPRS, LOGL_INFO,
"Removing TLLI %08x from list "
"(stale, length %d, max_len exceeded)\n",
tlli_info->tlli, state->enabled_tllis_count);
gbprox_delete_tlli(peer, tlli_info);
deleted_count += 1;
}
while (check_for_age && !llist_empty(&state->enabled_tllis)) {
time_t age;
struct gbproxy_tlli_info *tlli_info;
tlli_info = llist_entry(state->enabled_tllis.prev,
struct gbproxy_tlli_info,
list);
age = now - tlli_info->timestamp;
/* age < 0 only happens after system time jumps, discard entry */
if (age <= peer->cfg->tlli_max_age && age >= 0) {
check_for_age = 0;
continue;
}
LOGP(DGPRS, LOGL_INFO,
"Removing TLLI %08x from list "
"(stale, age %d, max_age exceeded)\n",
tlli_info->tlli, (int)age);
gbprox_delete_tlli(peer, tlli_info);
deleted_count += 1;
}
return deleted_count;
}
static struct gbproxy_tlli_info *gbprox_get_detached_tlli_info(
struct gbproxy_peer *peer,
struct gbproxy_tlli_info *tlli_info,
uint32_t tlli)
{
struct gbproxy_patch_state *state = &peer->patch_state;
if (!tlli_info) {
tlli_info = talloc_zero(peer, struct gbproxy_tlli_info);
tlli_info->tlli = tlli;
} else {
llist_del(&tlli_info->list);
OSMO_ASSERT(state->enabled_tllis_count > 0);
state->enabled_tllis_count -= 1;
peer->ctrg->ctr[GBPROX_PEER_CTR_TLLI_CACHE_SIZE].current =
state->enabled_tllis_count;
}
return tlli_info;
}
static void gbprox_update_tlli_info(struct gbproxy_tlli_info *tlli_info,
const uint8_t *imsi, size_t imsi_len)
{
if (!is_mi_imsi(imsi, imsi_len))
return;
tlli_info->mi_data_len = imsi_len;
tlli_info->mi_data =
talloc_realloc_size(tlli_info, tlli_info->mi_data, imsi_len);
OSMO_ASSERT(tlli_info->mi_data != NULL);
memcpy(tlli_info->mi_data, imsi, imsi_len);
}
void gbprox_reassign_tlli(struct gbproxy_tlli_info *tlli_info,
struct gbproxy_peer *peer, uint32_t new_tlli)
{
if (new_tlli == tlli_info->tlli)
return;
LOGP(DGPRS, LOGL_INFO,
"The TLLI has been reassigned from %08x to %08x\n",
tlli_info->tlli, new_tlli);
/* TODO: Save old TLLI */
tlli_info->tlli = new_tlli;
}
void gbprox_touch_tlli(struct gbproxy_peer *peer,
struct gbproxy_tlli_info *tlli_info, time_t now)
{
gbprox_get_detached_tlli_info(peer, tlli_info, tlli_info->tlli);
gbprox_attach_tlli_info(peer, now, tlli_info);
}
struct gbproxy_tlli_info *gbprox_register_tlli(
struct gbproxy_peer *peer, uint32_t tlli,
const uint8_t *imsi, size_t imsi_len, time_t now)
{
struct gbproxy_tlli_info *tlli_info;
int enable_patching = -1;
int tlli_already_known;
/* Check, whether the IMSI matches */
if (is_mi_imsi(imsi, imsi_len)) {
enable_patching = gbprox_check_imsi(peer, imsi, imsi_len);
if (enable_patching < 0)
return NULL;
}
tlli_info = gbprox_find_tlli(peer, tlli);
if (!tlli_info) {
tlli_info = gbprox_find_tlli_by_mi(peer, imsi, imsi_len);
if (tlli_info) {
/* TLLI has changed somehow, adjust it */
LOGP(DGPRS, LOGL_INFO,
"The TLLI has changed from %08x to %08x\n",
tlli_info->tlli, tlli);
tlli_info->tlli = tlli;
}
}
tlli_already_known = tlli_info != NULL;
tlli_info = gbprox_get_detached_tlli_info(peer, tlli_info, tlli);
OSMO_ASSERT(tlli_info != NULL);
if (!tlli_already_known)
LOGP(DGPRS, LOGL_INFO, "Adding TLLI %08x to list\n", tlli);
gbprox_attach_tlli_info(peer, now, tlli_info);
gbprox_update_tlli_info(tlli_info, imsi, imsi_len);
if (enable_patching >= 0)
tlli_info->enable_patching = enable_patching;
return tlli_info;
}
static void gbprox_unregister_tlli(struct gbproxy_peer *peer, uint32_t tlli)
{
struct gbproxy_tlli_info *tlli_info;
tlli_info = gbprox_find_tlli(peer, tlli);
if (tlli_info) {
LOGP(DGPRS, LOGL_INFO,
"Removing TLLI %08x from list\n",
tlli);
gbprox_delete_tlli(peer, tlli_info);
}
}
static int gbprox_check_tlli(struct gbproxy_peer *peer, uint32_t tlli)
{
struct gbproxy_tlli_info *tlli_info;
LOGP(DGPRS, LOGL_INFO, "Checking TLLI %08x, class: %d\n",
tlli, gprs_tlli_type(tlli));
if (!peer->cfg->check_imsi)
return 1;
tlli_info = gbprox_find_tlli(peer, tlli);
return tlli_info != NULL && tlli_info->enable_patching;
}
/* check whether patching is enabled at this level */
static int patching_is_enabled(struct gbproxy_peer *peer,
enum gbproxy_patch_mode need_at_least)
{
enum gbproxy_patch_mode patch_mode = peer->cfg->patch_mode;
if (patch_mode == GBPROX_PATCH_DEFAULT)
patch_mode = GBPROX_PATCH_LLC;
return need_at_least <= patch_mode;
}
/* check whether patching is enabled at this level */
static int patching_is_required(struct gbproxy_peer *peer,
enum gbproxy_patch_mode need_at_least)
{
return need_at_least <= peer->cfg->patch_mode;
}
/* patch RA identifier in place, update peer accordingly */
static void gbprox_patch_raid(uint8_t *raid_enc, struct gbproxy_peer *peer,
int to_bss, 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;
int old_mcc;
int old_mnc;
struct gprs_ra_id raid;
gsm48_parse_ra(&raid, raid_enc);
old_mcc = raid.mcc;
old_mnc = raid.mnc;
if (!to_bss) {
/* BSS -> SGSN */
/* save BSS side MCC/MNC */
if (!peer->cfg->core_mcc || raid.mcc == peer->cfg->core_mcc) {
state->local_mcc = 0;
} else {
state->local_mcc = raid.mcc;
raid.mcc = peer->cfg->core_mcc;
}
if (!peer->cfg->core_mnc || raid.mnc == peer->cfg->core_mnc) {
state->local_mnc = 0;
} else {
state->local_mnc = raid.mnc;
raid.mnc = peer->cfg->core_mnc;
}
} else {
/* SGSN -> BSS */
if (state->local_mcc)
raid.mcc = state->local_mcc;
if (state->local_mnc)
raid.mnc = state->local_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, to %s\n",
state->local_mcc || state->local_mnc ?
"" : "de",
log_text,
state->local_mcc, state->local_mnc,
peer->cfg->core_mcc, peer->cfg->core_mnc,
to_bss ? "BSS" : "SGSN");
if (state->local_mcc || state->local_mnc) {
enum gbprox_peer_ctr counter =
to_bss ?
GBPROX_PEER_CTR_RAID_PATCHED_SGSN :
GBPROX_PEER_CTR_RAID_PATCHED_BSS;
LOGP(DGPRS, LOGL_DEBUG,
"Patching %s to %s: "
"%d-%d-%d-%d -> %d-%d-%d-%d\n",
log_text,
to_bss ? "BSS" : "SGSN",
old_mcc, old_mnc, raid.lac, raid.rac,
raid.mcc, raid.mnc, raid.lac, raid.rac);
gsm48_construct_ra(raid_enc, &raid);
rate_ctr_inc(&peer->ctrg->ctr[counter]);
}
}
static void gbprox_patch_apn_ie(struct msgb *msg,
uint8_t *apn_ie, size_t apn_ie_len,
struct gbproxy_peer *peer,
size_t *new_apn_ie_len, const char *log_text)
{
struct apn_ie_hdr {
uint8_t iei;
uint8_t apn_len;
uint8_t apn[0];
} *hdr = (void *)apn_ie;
size_t apn_len = hdr->apn_len;
uint8_t *apn = hdr->apn;
OSMO_ASSERT(apn_ie_len == apn_len + sizeof(struct apn_ie_hdr));
OSMO_ASSERT(apn_ie_len > 2 && apn_ie_len <= 102);
if (peer->cfg->core_apn_size == 0) {
char str1[110];
/* Remove the IE */
LOGP(DGPRS, LOGL_DEBUG,
"Patching %s to SGSN: Removing APN '%s'\n",
log_text,
gprs_apn_to_str(str1, apn, apn_len));
*new_apn_ie_len = 0;
gprs_msgb_resize_area(msg, apn_ie, apn_ie_len, 0);
} else {
/* Resize the IE */
char str1[110];
char str2[110];
OSMO_ASSERT(peer->cfg->core_apn_size <= 100);
LOGP(DGPRS, LOGL_DEBUG,
"Patching %s to SGSN: "
"Replacing APN '%s' -> '%s'\n",
log_text,
gprs_apn_to_str(str1, apn, apn_len),
gprs_apn_to_str(str2, peer->cfg->core_apn,
peer->cfg->core_apn_size));
*new_apn_ie_len = peer->cfg->core_apn_size + 2;
gprs_msgb_resize_area(msg, apn, apn_len, peer->cfg->core_apn_size);
memcpy(apn, peer->cfg->core_apn, peer->cfg->core_apn_size);
hdr->apn_len = peer->cfg->core_apn_size;
}
rate_ctr_inc(&peer->ctrg->ctr[GBPROX_PEER_CTR_APN_PATCHED]);
}
static int gbprox_parse_gmm_attach_req(uint8_t *data, size_t data_len,
struct gbproxy_parse_context *parse_ctx)
{
uint8_t *value;
size_t value_len;
parse_ctx->llc_msg_name = "ATTACH_REQ";
/* Skip MS network capability */
if (lv_shift(&data, &data_len, NULL, &value_len) <= 0 ||
value_len < 1 || value_len > 2)
/* invalid */
return 0;;
/* Skip Attach type */
/* Skip Ciphering key sequence number */
/* Skip DRX parameter */
v_fixed_shift(&data, &data_len, 3, NULL);
/* Get Mobile identity */
if (lv_shift(&data, &data_len, &value, &value_len) <= 0 ||
value_len < 5 || value_len > 8)
/* invalid */
return 0;
if (is_mi_tmsi(value, value_len)) {
parse_ctx->ptmsi_enc = value;
} else if (is_mi_imsi(value, value_len)) {
parse_ctx->imsi = value;
parse_ctx->imsi_len = value_len;
}
if (v_fixed_shift(&data, &data_len, 6, &value) <= 0)
return 0;
parse_ctx->raid_enc = value;
return 1;
}
static int gbprox_parse_gmm_attach_ack(uint8_t *data, size_t data_len,
struct gbproxy_parse_context *parse_ctx)
{
uint8_t *value;
size_t value_len;
parse_ctx->llc_msg_name = "ATTACH_ACK";
/* Skip Attach result */
/* Skip Force to standby */
/* Skip Periodic RA update timer */
/* Skip Radio priority for SMS */
/* Skip Spare half octet */
v_fixed_shift(&data, &data_len, 3, NULL);
if (v_fixed_shift(&data, &data_len, 6, &value) <= 0)
return 0;
parse_ctx->raid_enc = value;
/* Skip P-TMSI signature (P-TMSI signature, opt, TV, length 4) */
tv_fixed_match(&data, &data_len, GSM48_IE_GMM_PTMSI_SIG, 3, NULL);
/* Skip Negotiated READY timer value (GPRS timer, opt, TV, length 2) */
tv_fixed_match(&data, &data_len, GSM48_IE_GMM_TIMER_READY, 1, NULL);
/* Allocated P-TMSI (Mobile identity, opt, TLV, length 7) */
if (tlv_match(&data, &data_len, GSM48_IE_GMM_ALLOC_PTMSI,
&value, &value_len) > 0 &&
is_mi_tmsi(value, value_len))
parse_ctx->new_ptmsi_enc = value;
return 1;
}
static int gbprox_parse_gmm_ra_upd_req(uint8_t *data, size_t data_len,
struct gbproxy_parse_context *parse_ctx)
{
uint8_t *value;
parse_ctx->llc_msg_name = "RA_UPD_REQ";
/* Skip Update type */
/* Skip GPRS ciphering key sequence number */
v_fixed_shift(&data, &data_len, 1, NULL);
if (v_fixed_shift(&data, &data_len, 6, &value) <= 0)
return 0;
parse_ctx->raid_enc = value;
return 1;
}
static int gbprox_parse_gmm_ra_upd_ack(uint8_t *data, size_t data_len,
struct gbproxy_parse_context *parse_ctx)
{
uint8_t *value;
size_t value_len;
parse_ctx->llc_msg_name = "RA_UPD_ACK";
/* Skip Force to standby */
/* Skip Update result */
/* Skip Periodic RA update timer */
v_fixed_shift(&data, &data_len, 2, NULL);
if (v_fixed_shift(&data, &data_len, 6, &value) <= 0)
return 0;
parse_ctx->raid_enc = value;
/* Skip P-TMSI signature (P-TMSI signature, opt, TV, length 4) */
tv_fixed_match(&data, &data_len, GSM48_IE_GMM_PTMSI_SIG, 3, NULL);
/* Allocated P-TMSI (Mobile identity, opt, TLV, length 7) */
if (tlv_match(&data, &data_len, GSM48_IE_GMM_ALLOC_PTMSI,
&value, &value_len) > 0 &&
is_mi_tmsi(value, value_len))
parse_ctx->new_ptmsi_enc = value;
return 1;
}
static int gbprox_parse_gmm_ptmsi_reall_cmd(uint8_t *data, size_t data_len,
struct gbproxy_parse_context *parse_ctx)
{
uint8_t *value;
size_t value_len;
parse_ctx->llc_msg_name = "PTMSI_REALL_CMD";
LOGP(DLLC, LOGL_NOTICE,
"Got P-TMSI Reallocation Command which is not covered by unit tests yet.\n");
/* Allocated P-TMSI */
if (lv_shift(&data, &data_len, &value, &value_len) > 0 &&
is_mi_tmsi(value, value_len))
parse_ctx->new_ptmsi_enc = value;
if (v_fixed_shift(&data, &data_len, 6, &value) <= 0)
return 0;
parse_ctx->raid_enc = value;
return 1;
}
static int gbprox_parse_gmm_id_resp(uint8_t *data, size_t data_len,
struct gbproxy_parse_context *parse_ctx)
{
uint8_t *value;
size_t value_len;
parse_ctx->llc_msg_name = "ID_RESP";
/* Mobile identity, Mobile identity 10.5.1.4, M LV 2-10 */
if (lv_shift(&data, &data_len, &value, &value_len) <= 0 ||
value_len < 1 || value_len > 9)
/* invalid */
return 0;
if (is_mi_tmsi(value, value_len)) {
parse_ctx->ptmsi_enc = value;
} else if (is_mi_imsi(value, value_len)) {
parse_ctx->imsi = value;
parse_ctx->imsi_len = value_len;
}
return 1;
}
static int gbprox_parse_gsm_act_pdp_req(uint8_t *data, size_t data_len,
struct gbproxy_parse_context *parse_ctx)
{
ssize_t old_len;
uint8_t *value;
size_t value_len;
parse_ctx->llc_msg_name = "ACT_PDP_REQ";
/* Skip Requested NSAPI */
/* Skip Requested LLC SAPI */
v_fixed_shift(&data, &data_len, 2, NULL);
/* Skip Requested QoS (support 04.08 and 24.008) */
if (lv_shift(&data, &data_len, NULL, &value_len) <= 0 ||
value_len < 4 || value_len > 14)
/* invalid */
return 0;;
/* Skip Requested PDP address */
if (lv_shift(&data, &data_len, NULL, &value_len) <= 0 ||
value_len < 2 || value_len > 18)
/* invalid */
return 0;
/* Access point name */
old_len = tlv_match(&data, &data_len,
GSM48_IE_GSM_APN, &value, &value_len);
if (old_len > 0 && value_len >=1 && value_len <= 100) {
parse_ctx->apn_ie = data - old_len;
parse_ctx->apn_ie_len = old_len;
}
return 1;
}
struct gbproxy_peer *peer_by_bssgp_tlv(struct gbproxy_config *cfg, struct tlv_parsed *tp)
{
if (TLVP_PRESENT(tp, BSSGP_IE_BVCI)) {
uint16_t bvci;
bvci = ntohs(tlvp_val16_unal(tp, BSSGP_IE_BVCI));
if (bvci >= 2)
return peer_by_bvci(cfg, bvci);
}
if (TLVP_PRESENT(tp, BSSGP_IE_ROUTEING_AREA)) {
uint8_t *rai = (uint8_t *)TLVP_VAL(tp, BSSGP_IE_ROUTEING_AREA);
/* Only compare LAC part, since MCC/MNC are possibly patched.
* Since the LAC of different BSS must be different when
* MCC/MNC are patched, collisions shouldn't happen. */
return peer_by_lac(cfg, rai);
}
if (TLVP_PRESENT(tp, BSSGP_IE_LOCATION_AREA)) {
uint8_t *lai = (uint8_t *)TLVP_VAL(tp, BSSGP_IE_LOCATION_AREA);
return peer_by_lac(cfg, lai);
}
return NULL;
}
static int gbprox_parse_dtap(uint8_t *data, size_t data_len,
struct gbproxy_parse_context *parse_ctx) __attribute__((nonnull));
static int gbprox_parse_dtap(uint8_t *data, size_t data_len,
struct gbproxy_parse_context *parse_ctx)
{
struct gsm48_hdr *g48h;
if (v_fixed_shift(&data, &data_len, sizeof(*g48h), (uint8_t **)&g48h) <= 0)
return 0;
parse_ctx->g48_hdr = g48h;
if ((g48h->proto_discr & 0x0f) != GSM48_PDISC_MM_GPRS &&
(g48h->proto_discr & 0x0f) != GSM48_PDISC_SM_GPRS)
return 1;
switch (g48h->msg_type) {
case GSM48_MT_GMM_ATTACH_REQ:
return gbprox_parse_gmm_attach_req(data, data_len, parse_ctx);
case GSM48_MT_GMM_ATTACH_ACK:
return gbprox_parse_gmm_attach_ack(data, data_len, parse_ctx);
case GSM48_MT_GMM_RA_UPD_REQ:
return gbprox_parse_gmm_ra_upd_req(data, data_len, parse_ctx);
case GSM48_MT_GMM_RA_UPD_ACK:
return gbprox_parse_gmm_ra_upd_ack(data, data_len, parse_ctx);
case GSM48_MT_GMM_PTMSI_REALL_CMD:
return gbprox_parse_gmm_ptmsi_reall_cmd(data, data_len, parse_ctx);
case GSM48_MT_GSM_ACT_PDP_REQ:
return gbprox_parse_gsm_act_pdp_req(data, data_len, parse_ctx);
case GSM48_MT_GMM_ID_RESP:
return gbprox_parse_gmm_id_resp(data, data_len, parse_ctx);
break;
case GSM48_MT_GMM_DETACH_REQ:
/* TODO: Check power off if !to_bss, if yes invalidate */
parse_ctx->llc_msg_name = "DETACH_REQ";
break;
case GSM48_MT_GMM_DETACH_ACK:
parse_ctx->llc_msg_name = "DETACH_ACK";
parse_ctx->invalidate_tlli = 1;
break;
default:
break;
};
return 1;
}
static int allow_message_patching(struct gbproxy_peer *peer, int msg_type)
{
if (msg_type >= GSM48_MT_GSM_ACT_PDP_REQ) {
return patching_is_enabled(peer, GBPROX_PATCH_LLC_GSM);
} else if (msg_type > GSM48_MT_GMM_ATTACH_REJ) {
return patching_is_enabled(peer, GBPROX_PATCH_LLC);
} else if (msg_type > GSM48_MT_GMM_ATTACH_REQ) {
return patching_is_enabled(peer, GBPROX_PATCH_LLC_ATTACH);
} else {
return patching_is_enabled(peer, GBPROX_PATCH_LLC_ATTACH_REQ);
}
}
static int gbprox_parse_llc(uint8_t *llc, size_t llc_len,
struct gbproxy_parse_context *parse_ctx) __attribute__((nonnull));
static int gbprox_parse_llc(uint8_t *llc, size_t llc_len,
struct gbproxy_parse_context *parse_ctx)
{
struct gprs_llc_hdr_parsed *ghp = &parse_ctx->llc_hdr_parsed;
int rc;
int fcs;
/* parse LLC */
rc = gprs_llc_hdr_parse(ghp, llc, llc_len);
gprs_llc_hdr_dump(ghp);
if (rc != 0) {
LOGP(DLLC, LOGL_NOTICE, "Error during LLC header parsing\n");
return 0;
}
fcs = gprs_llc_fcs(llc, ghp->crc_length);
LOGP(DLLC, LOGL_DEBUG, "Got LLC message, CRC: %06x (computed %06x)\n",
ghp->fcs, fcs);
if (!ghp->data)
return 0;
if (ghp->sapi != GPRS_SAPI_GMM)
return 0;
if (ghp->cmd != GPRS_LLC_UI)
return 0;
if (ghp->is_encrypted) {
parse_ctx->need_decryption = 1;
return 0;
}
return gbprox_parse_dtap(ghp->data, ghp->data_len, parse_ctx);
}
static int gbprox_patch_llc(struct msgb *msg, uint8_t *llc, size_t llc_len,
struct gbproxy_peer *peer,
struct gbproxy_tlli_info *tlli_info, int *len_change,
struct gbproxy_parse_context *parse_ctx) __attribute__((nonnull));
static int gbprox_patch_llc(struct msgb *msg, uint8_t *llc, size_t llc_len,
struct gbproxy_peer *peer,
struct gbproxy_tlli_info *tlli_info, int *len_change,
struct gbproxy_parse_context *parse_ctx)
{
struct gprs_llc_hdr_parsed *ghp = &parse_ctx->llc_hdr_parsed;
int have_patched = 0;
int fcs;
if (!allow_message_patching(peer, parse_ctx->g48_hdr->msg_type))
return have_patched;
if (parse_ctx->raid_enc) {
gbprox_patch_raid(parse_ctx->raid_enc, peer, parse_ctx->to_bss,
parse_ctx->llc_msg_name);
have_patched = 1;
}
if (parse_ctx->apn_ie &&
peer->cfg->core_apn &&
!parse_ctx->to_bss &&
gbprox_check_tlli(peer, parse_ctx->tlli)) {
size_t new_len;
gbprox_patch_apn_ie(msg,
parse_ctx->apn_ie, parse_ctx->apn_ie_len,
peer, &new_len, parse_ctx->llc_msg_name);
*len_change += (int)new_len - (int)parse_ctx->apn_ie_len;
have_patched = 1;
}
if (have_patched) {
llc_len += *len_change;
ghp->crc_length += *len_change;
/* Fix FCS */
fcs = gprs_llc_fcs(llc, ghp->crc_length);
LOGP(DLLC, LOGL_DEBUG, "Updated LLC message, CRC: %06x -> %06x\n",
ghp->fcs, fcs);
llc[llc_len - 3] = fcs & 0xff;
llc[llc_len - 2] = (fcs >> 8) & 0xff;
llc[llc_len - 1] = (fcs >> 16) & 0xff;
}
return have_patched;
}
static void gbprox_log_parse_context(struct gbproxy_parse_context *parse_ctx,
const char *default_msg_name)
{
const char *msg_name = default_msg_name;
const char *sep = "";
if (!parse_ctx->tlli_enc &&
!parse_ctx->ptmsi_enc &&
!parse_ctx->new_ptmsi_enc &&
!parse_ctx->imsi)
return;
if (parse_ctx->llc_msg_name)
msg_name = parse_ctx->llc_msg_name;
LOGP(DGPRS, LOGL_DEBUG, "%s: Got", msg_name);
if (parse_ctx->tlli_enc) {
LOGP(DGPRS, LOGL_DEBUG, "%s TLLI %08x", sep, parse_ctx->tlli);
sep = ",";
}
if (parse_ctx->ptmsi_enc) {
uint32_t ptmsi = GSM_RESERVED_TMSI;
int ok;
ok = parse_mi_tmsi(parse_ctx->ptmsi_enc, GSM48_TMSI_LEN, &ptmsi);
LOGP(DGPRS, LOGL_DEBUG, "%s PTMSI %08x%s",
sep, ptmsi, ok ? "" : " (parse error)");
sep = ",";
}
if (parse_ctx->new_ptmsi_enc) {
uint32_t new_ptmsi = GSM_RESERVED_TMSI;
int ok;
ok = parse_mi_tmsi(parse_ctx->new_ptmsi_enc, GSM48_TMSI_LEN,
&new_ptmsi);
LOGP(DGPRS, LOGL_DEBUG, "%s new PTMSI %08x%s",
sep, new_ptmsi, ok ? "" : " (parse error)");
sep = ",";
}
if (parse_ctx->imsi) {
char mi_buf[200];
mi_buf[0] = '\0';
gsm48_mi_to_string(mi_buf, sizeof(mi_buf),
parse_ctx->imsi, parse_ctx->imsi_len);
LOGP(DGPRS, LOGL_DEBUG, "%s IMSI %s",
sep, mi_buf);
sep = ",";
}
LOGP(DGPRS, LOGL_DEBUG, "\n");
}
static struct gbproxy_tlli_info *gbprox_update_state(
struct gbproxy_peer *peer, time_t now,
struct gbproxy_parse_context *parse_ctx)
{
struct gbproxy_tlli_info *tlli_info = NULL;
if (!peer->cfg->check_imsi)
return NULL;
if (parse_ctx->tlli_enc)
tlli_info = gbprox_find_tlli(peer, parse_ctx->tlli);
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;
case GSM48_MT_GMM_ATTACH_REJ:
rate_ctr_inc(&peer->ctrg->ctr[GBPROX_PEER_CTR_ATTACH_REJS]);
break;
default:
break;
}
}
gbprox_log_parse_context(parse_ctx, "BSSGP");
if (parse_ctx->tlli_enc && parse_ctx->new_ptmsi_enc &&
parse_ctx->to_bss) {
/* A new PTMSI has been signaled in the message,
* register new TLLI */
uint32_t new_ptmsi;
uint32_t new_tlli;
if (!parse_mi_tmsi(parse_ctx->new_ptmsi_enc, GSM48_TMSI_LEN,
&new_ptmsi)) {
LOGP(DGPRS, LOGL_ERROR,
"Failed to parse new TLLI/PTMSI (current is %08x)\n",
parse_ctx->tlli);
return tlli_info;
}
new_tlli = gprs_tmsi2tlli(new_ptmsi, TLLI_LOCAL);
LOGP(DGPRS, LOGL_INFO,
"Got new TLLI/PTMSI %08x/%08x (current is %08x)\n",
new_tlli, new_ptmsi, parse_ctx->tlli);
if (tlli_info) {
gbprox_reassign_tlli(tlli_info, peer, new_tlli);
gbprox_touch_tlli(peer, tlli_info, now);
} else {
tlli_info =
gbprox_register_tlli(peer, new_tlli,
parse_ctx->imsi,
parse_ctx->imsi_len, now);
}
} else if (parse_ctx->tlli_enc && parse_ctx->llc) {
tlli_info =
gbprox_register_tlli(peer, parse_ctx->tlli,
parse_ctx->imsi,
parse_ctx->imsi_len, now);
} else if (tlli_info) {
gbprox_touch_tlli(peer, tlli_info, now);
}
if (parse_ctx->imsi && tlli_info && tlli_info->mi_data_len == 0)
gbprox_update_tlli_info(tlli_info,
parse_ctx->imsi, parse_ctx->imsi_len);
return tlli_info;
}
static void gbprox_update_state_after(struct gbproxy_peer *peer,
struct gbproxy_tlli_info *tlli_info,
time_t now,
struct gbproxy_parse_context *parse_ctx)
{
if (parse_ctx->invalidate_tlli)
gbprox_unregister_tlli(peer, parse_ctx->tlli);
gbprox_remove_stale_tllis(peer, now);
}
static int gbprox_parse_bssgp(uint8_t *bssgp, size_t bssgp_len,
struct gbproxy_parse_context *parse_ctx)
{
struct bssgp_normal_hdr *bgph;
struct bssgp_ud_hdr *budh = NULL;
struct tlv_parsed *tp = &parse_ctx->bssgp_tp;
uint8_t pdu_type;
uint8_t *data;
size_t data_len;
int rc;
if (bssgp_len < sizeof(struct bssgp_normal_hdr))
return 0;
bgph = (struct bssgp_normal_hdr *)bssgp;
pdu_type = bgph->pdu_type;
if (pdu_type == BSSGP_PDUT_UL_UNITDATA ||
pdu_type == BSSGP_PDUT_DL_UNITDATA) {
if (bssgp_len < sizeof(struct bssgp_ud_hdr))
return 0;
budh = (struct bssgp_ud_hdr *)bssgp;
bgph = NULL;
data = budh->data;
data_len = bssgp_len - sizeof(*budh);
} else {
data = bgph->data;
data_len = bssgp_len - sizeof(*bgph);
}
if (bssgp_tlv_parse(tp, data, data_len) < 0)
return 0;
parse_ctx->pdu_type = pdu_type;
parse_ctx->bud_hdr = budh;
parse_ctx->bgp_hdr = bgph;
parse_ctx->bssgp_data = data;
parse_ctx->bssgp_data_len = data_len;
if (budh)
parse_ctx->tlli_enc = (uint8_t *)&budh->tlli;
if (TLVP_PRESENT(tp, BSSGP_IE_ROUTEING_AREA))
parse_ctx->bssgp_raid_enc = (uint8_t *)TLVP_VAL(tp, BSSGP_IE_ROUTEING_AREA);
if (TLVP_PRESENT(tp, BSSGP_IE_CELL_ID))
parse_ctx->bssgp_raid_enc = (uint8_t *)TLVP_VAL(tp, BSSGP_IE_CELL_ID);
if (TLVP_PRESENT(tp, BSSGP_IE_IMSI)) {
parse_ctx->imsi = (uint8_t *)TLVP_VAL(tp, BSSGP_IE_IMSI);
parse_ctx->imsi_len = TLVP_LEN(tp, BSSGP_IE_IMSI);
}
if (TLVP_PRESENT(tp, BSSGP_IE_TLLI))
parse_ctx->tlli_enc = (uint8_t *)TLVP_VAL(tp, BSSGP_IE_TLLI);
if (TLVP_PRESENT(tp, BSSGP_IE_TMSI) && pdu_type == BSSGP_PDUT_PAGING_PS)
parse_ctx->ptmsi_enc = (uint8_t *)TLVP_VAL(tp, BSSGP_IE_TMSI);
if (TLVP_PRESENT(tp, BSSGP_IE_LLC_PDU)) {
uint8_t *llc = (uint8_t *)TLVP_VAL(tp, BSSGP_IE_LLC_PDU);
size_t llc_len = TLVP_LEN(tp, BSSGP_IE_LLC_PDU);
rc = gbprox_parse_llc(llc, llc_len, parse_ctx);
if (!rc)
return 0;
parse_ctx->llc = llc;
parse_ctx->llc_len = llc_len;
}
if (parse_ctx->tlli_enc) {
uint32_t tmp_tlli;
memcpy(&tmp_tlli, parse_ctx->tlli_enc, sizeof(tmp_tlli));
parse_ctx->tlli = ntohl(tmp_tlli);
}
return 1;
}
/* patch BSSGP message to use core_mcc/mnc on the SGSN side */
static void gbprox_patch_bssgp(struct msgb *msg, uint8_t *bssgp, size_t bssgp_len,
struct gbproxy_peer *peer,
struct gbproxy_tlli_info *tlli_info, int *len_change,
struct gbproxy_parse_context *parse_ctx)
__attribute__((nonnull));
static void gbprox_patch_bssgp(struct msgb *msg, uint8_t *bssgp, size_t bssgp_len,
struct gbproxy_peer *peer,
struct gbproxy_tlli_info *tlli_info, int *len_change,
struct gbproxy_parse_context *parse_ctx)
{
const char *err_info = NULL;
int err_ctr = -1;
if (!patching_is_enabled(peer, GBPROX_PATCH_BSSGP))
return;
if (parse_ctx->bssgp_raid_enc)
gbprox_patch_raid(parse_ctx->bssgp_raid_enc, peer,
parse_ctx->to_bss, "BSSGP");
if (!patching_is_enabled(peer, GBPROX_PATCH_LLC_ATTACH_REQ))
return;
if (parse_ctx->need_decryption &&
patching_is_required(peer, GBPROX_PATCH_LLC_ATTACH)) {
/* Patching LLC messages has been requested
* explicitly, but the message (including the
* type) is encrypted, so we possibly fail to
* patch the LLC part of the message. */
err_ctr = GBPROX_PEER_CTR_PATCH_CRYPT_ERR;
err_info = "GMM message is encrypted";
goto patch_error;
}
if (parse_ctx->llc) {
uint8_t *llc = parse_ctx->llc;
size_t llc_len = parse_ctx->llc_len;
int llc_len_change = 0;
gbprox_patch_llc(msg, llc, llc_len, peer, tlli_info,
&llc_len_change, parse_ctx);
/* Note that the APN might have been resized here, but no
* pointer int the parse_ctx will refer to an adress after the
* APN. So it's possible to patch first and do the TLLI
* handling afterwards. */
if (llc_len_change) {
llc_len += llc_len_change;
/* Fix LLC IE len */
/* TODO: This is a kludge, but the a pointer to the
* start of the IE is not available here */
if (llc[-2] == BSSGP_IE_LLC_PDU && llc[-1] & 0x80) {
/* most probably a one byte length */
if (llc_len > 127) {
err_info = "Cannot increase size";
err_ctr = GBPROX_PEER_CTR_PATCH_ERR;
goto patch_error;
}
llc[-1] = llc_len | 0x80;
} else {
llc[-2] = (llc_len >> 8) & 0x7f;
llc[-1] = llc_len & 0xff;
}
*len_change += llc_len_change;
}
/* Note that the tp struct might contain invalid pointers here
* if the LLC field has changed its size */
parse_ctx->llc_len = llc_len;
}
return;
patch_error:
OSMO_ASSERT(err_ctr >= 0);
rate_ctr_inc(&peer->ctrg->ctr[err_ctr]);
LOGP(DGPRS, LOGL_ERROR,
"Failed to patch BSSGP message as requested: %s.\n", err_info);
}
/* patch BSSGP message to use core_mcc/mnc on the SGSN side */
static void gbprox_process_bssgp_message(struct gbproxy_config *cfg,
struct msgb *msg,
struct gbproxy_peer *peer, int to_bss)
{
struct gbproxy_parse_context parse_ctx = {0};
int rc;
int len_change = 0;
time_t now;
struct gbproxy_tlli_info *tlli_info;
if (!cfg->core_mcc && !cfg->core_mnc && !cfg->core_apn)
return;
parse_ctx.to_bss = to_bss;
rc = gbprox_parse_bssgp(msgb_bssgph(msg), msgb_bssgp_len(msg),
&parse_ctx);
if (!rc) {
if (!parse_ctx.need_decryption) {
LOGP(DGPRS, LOGL_ERROR,
"Failed to parse BSSGP/GMM message\n");
return;
}
}
if (!peer && msgb_bvci(msg) >= 2)
peer = peer_by_bvci(cfg, msgb_bvci(msg));
if (!peer && !to_bss)
peer = gbprox_peer_by_nsei(cfg, msgb_nsei(msg));
if (!peer)
peer = peer_by_bssgp_tlv(cfg, &parse_ctx.bssgp_tp);
if (!peer) {
LOGP(DLLC, LOGL_INFO,
"NSEI=%d(%s) patching: didn't find peer for message, "
"PDU %d\n",
msgb_nsei(msg), to_bss ? "SGSN" : "BSS", parse_ctx.pdu_type);
/* Increment counter */
rate_ctr_inc(&cfg->ctrg->ctr[GBPROX_GLOB_CTR_PATCH_PEER_ERR]);
return;
}
now = time(NULL);
tlli_info = gbprox_update_state(peer, now, &parse_ctx);
gbprox_patch_bssgp(msg, msgb_bssgph(msg), msgb_bssgp_len(msg),
peer, tlli_info, &len_change, &parse_ctx);
gbprox_update_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,
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_relay2sgsn");
int rc;
gbprox_process_bssgp_message(cfg, msg, peer, 0);
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 = 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 = 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 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 = gbprox_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 = 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 */
return gbprox_relay2sgsn(cfg, msg, from_peer, 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 = 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 = 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 *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, 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 = 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, 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 *msg, uint32_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 *peer;
uint16_t bvci;
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, msg);
}
rc = bssgp_tlv_parse(&tp, bgph->data, data_len);
switch (pdu_type) {
case BSSGP_PDUT_BVC_RESET:
rc = rx_reset_from_sgsn(cfg, 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 = 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, 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, msg);
break;
}
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]);
return bssgp_tx_status(BSSGP_CAUSE_MISSING_MAND_IE, NULL, 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]);
return bssgp_tx_status(BSSGP_CAUSE_UNKNOWN_BVCI, NULL, 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;
struct gbproxy_peer *peer;
int remote_end_is_sgsn = nsei == cfg->nsip_sgsn_nsei;
if (remote_end_is_sgsn)
gbprox_process_bssgp_message(cfg, msg, NULL, 1);
/* 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 {
peer = peer_by_bvci(cfg, ns_bvci);
/* All other BVCI are PTP and thus can be simply forwarded */
if (!remote_end_is_sgsn) {
if (peer)
check_peer_nsei(peer, nsei);
return gbprox_relay2sgsn(cfg, msg, peer, ns_bvci);
}
/* else: SGSN -> BSS direction */
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);
}
rc = gbprox_relay2peer(msg, peer, 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 = gbprox_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 gbprox_cleanup_peers(struct gbproxy_config *cfg, uint16_t nsei, uint16_t bvci)
{
int counter = 0;
struct gbproxy_peer *peer, *tmp;
llist_for_each_entry_safe(peer, tmp, &cfg->bts_peers, list) {
if (peer->nsei != nsei)
continue;
if (bvci && peer->bvci != bvci)
continue;
gbproxy_peer_free(peer);
counter += 1;
}
return counter;
}
int gbproxy_init_config(struct gbproxy_config *cfg)
{
INIT_LLIST_HEAD(&cfg->bts_peers);
cfg->ctrg = rate_ctr_group_alloc(tall_bsc_ctx, &global_ctrg_desc, 0);
return 0;
}
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