| /* 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)); |
| } |
| |
| int gbprox_set_patch_filter(struct gbproxy_config *cfg, const char *filter, |
| const char **err_msg) |
| { |
| static char err_buf[300]; |
| int rc; |
| |
| if (cfg->check_imsi) { |
| regfree(&cfg->imsi_re_comp); |
| cfg->check_imsi = 0; |
| } |
| |
| 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; |
| struct gbproxy_tlli_info *tlli_info = NULL, *nxt; |
| int count = 0; |
| int deleted_count = 0; |
| |
| llist_for_each_entry_safe(tlli_info, nxt, &state->enabled_tllis, list) { |
| int is_stale = 0; |
| time_t age = now - tlli_info->timestamp; |
| |
| count += 1; |
| |
| if (peer->cfg->tlli_max_len > 0) |
| is_stale = is_stale || count > peer->cfg->tlli_max_len; |
| |
| if (peer->cfg->tlli_max_age > 0) |
| is_stale = is_stale || age > peer->cfg->tlli_max_age; |
| |
| if (!is_stale) |
| continue; |
| |
| LOGP(DGPRS, LOGL_INFO, |
| "Removing TLLI %08x from list (stale)\n", |
| tlli_info->tlli); |
| |
| gbprox_delete_tlli(peer, tlli_info); |
| tlli_info = NULL; |
| |
| 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_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; |
| } |
| |
| 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; |
| } |
| |
| 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, 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, 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 void 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; |
| |
| 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; |
| } |
| 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_register_tlli(peer, new_tlli, |
| parse_ctx->imsi, parse_ctx->imsi_len, now); |
| } else if (parse_ctx->tlli_enc && parse_ctx->llc) { |
| gbprox_register_tlli(peer, parse_ctx->tlli, |
| parse_ctx->imsi, parse_ctx->imsi_len, now); |
| } |
| |
| return; |
| } |
| |
| static void gbprox_update_state_after(struct gbproxy_peer *peer, 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, 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, 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, &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; |
| |
| 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); |
| |
| gbprox_update_state(peer, now, &parse_ctx); |
| |
| gbprox_patch_bssgp(msg, msgb_bssgph(msg), msgb_bssgp_len(msg), |
| peer, &len_change, &parse_ctx); |
| |
| gbprox_update_state_after(peer, 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; |
| } |