| |
| /* BSC Multiplexer/NAT Utilities */ |
| |
| /* |
| * (C) 2010-2011 by Holger Hans Peter Freyther <zecke@selfish.org> |
| * (C) 2010-2011 by On-Waves |
| * 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 <openbsc/bsc_nat.h> |
| #include <openbsc/bsc_nat_sccp.h> |
| #include <openbsc/bsc_msc.h> |
| #include <openbsc/gsm_data.h> |
| #include <openbsc/debug.h> |
| #include <openbsc/ipaccess.h> |
| #include <openbsc/vty.h> |
| |
| #include <osmocom/core/linuxlist.h> |
| #include <osmocom/core/talloc.h> |
| #include <osmocom/gsm/gsm0808.h> |
| |
| #include <osmocom/gsm/protocol/gsm_08_08.h> |
| #include <osmocom/gsm/protocol/gsm_04_11.h> |
| |
| #include <osmocom/sccp/sccp.h> |
| |
| #include <netinet/in.h> |
| #include <arpa/inet.h> |
| #include <unistd.h> |
| |
| static const struct rate_ctr_desc bsc_cfg_ctr_description[] = { |
| [BCFG_CTR_SCCP_CONN] = { "sccp.conn", "SCCP Connections "}, |
| [BCFG_CTR_SCCP_CALLS] = { "sccp.calls", "SCCP Assignment Commands "}, |
| [BCFG_CTR_NET_RECONN] = { "net.reconnects", "Network reconnects "}, |
| [BCFG_CTR_DROPPED_SCCP] = { "dropped.sccp", "Dropped SCCP connections."}, |
| [BCFG_CTR_DROPPED_CALLS] = { "dropped.calls", "Dropped active calls. "}, |
| [BCFG_CTR_REJECTED_CR] = { "rejected.cr", "Rejected CR due filter "}, |
| [BCFG_CTR_REJECTED_MSG] = { "rejected.msg", "Rejected MSG due filter "}, |
| [BCFG_CTR_ILL_PACKET] = { "rejected.ill", "Rejected due parse error "}, |
| [BCFG_CTR_CON_TYPE_LU] = { "conn.lu", "Conn Location Update "}, |
| [BCFG_CTR_CON_CMSERV_RQ] = { "conn.rq", "Conn CM Service Req "}, |
| [BCFG_CTR_CON_PAG_RESP] = { "conn.pag", "Conn Paging Response "}, |
| [BCFG_CTR_CON_SSA] = { "conn.ssa", "Conn USSD "}, |
| [BCFG_CTR_CON_OTHER] = { "conn.other", "Conn Other "}, |
| }; |
| |
| static const struct rate_ctr_group_desc bsc_cfg_ctrg_desc = { |
| .group_name_prefix = "nat.bsc", |
| .group_description = "NAT BSC Statistics", |
| .num_ctr = ARRAY_SIZE(bsc_cfg_ctr_description), |
| .ctr_desc = bsc_cfg_ctr_description, |
| }; |
| |
| static const struct rate_ctr_desc acc_list_ctr_description[] = { |
| [ACC_LIST_BSC_FILTER] = { "access-list.bsc-filter", "Rejected by rule for BSC"}, |
| [ACC_LIST_NAT_FILTER] = { "access-list.nat-filter", "Rejected by rule for NAT"}, |
| }; |
| |
| static const struct rate_ctr_group_desc bsc_cfg_acc_list_desc = { |
| .group_name_prefix = "nat.filter", |
| .group_description = "NAT Access-List Statistics", |
| .num_ctr = ARRAY_SIZE(acc_list_ctr_description), |
| .ctr_desc = acc_list_ctr_description, |
| }; |
| |
| struct bsc_nat *bsc_nat_alloc(void) |
| { |
| struct bsc_nat *nat = talloc_zero(tall_bsc_ctx, struct bsc_nat); |
| if (!nat) |
| return NULL; |
| |
| nat->main_dest = talloc_zero(nat, struct bsc_msc_dest); |
| if (!nat->main_dest) { |
| talloc_free(nat); |
| return NULL; |
| } |
| |
| INIT_LLIST_HEAD(&nat->sccp_connections); |
| INIT_LLIST_HEAD(&nat->bsc_connections); |
| INIT_LLIST_HEAD(&nat->paging_groups); |
| INIT_LLIST_HEAD(&nat->bsc_configs); |
| INIT_LLIST_HEAD(&nat->access_lists); |
| INIT_LLIST_HEAD(&nat->dests); |
| INIT_LLIST_HEAD(&nat->num_rewr); |
| INIT_LLIST_HEAD(&nat->smsc_rewr); |
| INIT_LLIST_HEAD(&nat->tpdest_match); |
| |
| nat->stats.sccp.conn = osmo_counter_alloc("nat.sccp.conn"); |
| nat->stats.sccp.calls = osmo_counter_alloc("nat.sccp.calls"); |
| nat->stats.bsc.reconn = osmo_counter_alloc("nat.bsc.conn"); |
| nat->stats.bsc.auth_fail = osmo_counter_alloc("nat.bsc.auth_fail"); |
| nat->stats.msc.reconn = osmo_counter_alloc("nat.msc.conn"); |
| nat->stats.ussd.reconn = osmo_counter_alloc("nat.ussd.conn"); |
| nat->auth_timeout = 2; |
| nat->ping_timeout = 20; |
| nat->pong_timeout = 5; |
| |
| llist_add(&nat->main_dest->list, &nat->dests); |
| nat->main_dest->ip = talloc_strdup(nat, "127.0.0.1"); |
| nat->main_dest->port = 5000; |
| |
| return nat; |
| } |
| |
| void bsc_nat_set_msc_ip(struct bsc_nat *nat, const char *ip) |
| { |
| bsc_replace_string(nat, &nat->main_dest->ip, ip); |
| } |
| |
| struct bsc_connection *bsc_connection_alloc(struct bsc_nat *nat) |
| { |
| struct bsc_connection *con = talloc_zero(nat, struct bsc_connection); |
| if (!con) |
| return NULL; |
| |
| con->nat = nat; |
| osmo_wqueue_init(&con->write_queue, 100); |
| INIT_LLIST_HEAD(&con->cmd_pending); |
| return con; |
| } |
| |
| struct bsc_config *bsc_config_alloc(struct bsc_nat *nat, const char *token) |
| { |
| struct bsc_config *conf = talloc_zero(nat, struct bsc_config); |
| if (!conf) |
| return NULL; |
| |
| conf->token = talloc_strdup(conf, token); |
| conf->nr = nat->num_bsc; |
| conf->nat = nat; |
| conf->max_endpoints = 32; |
| conf->paging_group = PAGIN_GROUP_UNASSIGNED; |
| |
| INIT_LLIST_HEAD(&conf->lac_list); |
| |
| llist_add_tail(&conf->entry, &nat->bsc_configs); |
| ++nat->num_bsc; |
| |
| conf->stats.ctrg = rate_ctr_group_alloc(conf, &bsc_cfg_ctrg_desc, conf->nr); |
| if (!conf->stats.ctrg) { |
| talloc_free(conf); |
| return NULL; |
| } |
| |
| return conf; |
| } |
| |
| void bsc_config_free(struct bsc_config *cfg) |
| { |
| rate_ctr_group_free(cfg->stats.ctrg); |
| } |
| |
| static void _add_lac(void *ctx, struct llist_head *list, int _lac) |
| { |
| struct bsc_lac_entry *lac; |
| |
| llist_for_each_entry(lac, list, entry) |
| if (lac->lac == _lac) |
| return; |
| |
| lac = talloc_zero(ctx, struct bsc_lac_entry); |
| if (!lac) { |
| LOGP(DNAT, LOGL_ERROR, "Failed to allocate.\n"); |
| return; |
| } |
| |
| lac->lac = _lac; |
| llist_add_tail(&lac->entry, list); |
| } |
| |
| static void _del_lac(struct llist_head *list, int _lac) |
| { |
| struct bsc_lac_entry *lac; |
| |
| llist_for_each_entry(lac, list, entry) |
| if (lac->lac == _lac) { |
| llist_del(&lac->entry); |
| talloc_free(lac); |
| return; |
| } |
| } |
| |
| void bsc_config_add_lac(struct bsc_config *cfg, int _lac) |
| { |
| _add_lac(cfg, &cfg->lac_list, _lac); |
| } |
| |
| void bsc_config_del_lac(struct bsc_config *cfg, int _lac) |
| { |
| _del_lac(&cfg->lac_list, _lac); |
| } |
| |
| struct bsc_nat_paging_group *bsc_nat_paging_group_create(struct bsc_nat *nat, int group) |
| { |
| struct bsc_nat_paging_group *pgroup; |
| |
| pgroup = talloc_zero(nat, struct bsc_nat_paging_group); |
| if (!pgroup) { |
| LOGP(DNAT, LOGL_ERROR, "Failed to allocate a paging group.\n"); |
| return NULL; |
| } |
| |
| pgroup->nr = group; |
| INIT_LLIST_HEAD(&pgroup->lists); |
| llist_add_tail(&pgroup->entry, &nat->paging_groups); |
| return pgroup; |
| } |
| |
| void bsc_nat_paging_group_delete(struct bsc_nat_paging_group *pgroup) |
| { |
| llist_del(&pgroup->entry); |
| talloc_free(pgroup); |
| } |
| |
| struct bsc_nat_paging_group *bsc_nat_paging_group_num(struct bsc_nat *nat, int group) |
| { |
| struct bsc_nat_paging_group *pgroup; |
| |
| llist_for_each_entry(pgroup, &nat->paging_groups, entry) |
| if (pgroup->nr == group) |
| return pgroup; |
| |
| return NULL; |
| } |
| |
| void bsc_nat_paging_group_add_lac(struct bsc_nat_paging_group *pgroup, int lac) |
| { |
| _add_lac(pgroup, &pgroup->lists, lac); |
| } |
| |
| void bsc_nat_paging_group_del_lac(struct bsc_nat_paging_group *pgroup, int lac) |
| { |
| _del_lac(&pgroup->lists, lac); |
| } |
| |
| int bsc_config_handles_lac(struct bsc_config *cfg, int lac_nr) |
| { |
| struct bsc_nat_paging_group *pgroup; |
| struct bsc_lac_entry *entry; |
| |
| llist_for_each_entry(entry, &cfg->lac_list, entry) |
| if (entry->lac == lac_nr) |
| return 1; |
| |
| /* now lookup the paging group */ |
| pgroup = bsc_nat_paging_group_num(cfg->nat, cfg->paging_group); |
| if (!pgroup) |
| return 0; |
| |
| llist_for_each_entry(entry, &pgroup->lists, entry) |
| if (entry->lac == lac_nr) |
| return 1; |
| |
| return 0; |
| } |
| |
| void sccp_connection_destroy(struct sccp_connections *conn) |
| { |
| LOGP(DNAT, LOGL_DEBUG, "Destroy 0x%x <-> 0x%x mapping for con %p\n", |
| sccp_src_ref_to_int(&conn->real_ref), |
| sccp_src_ref_to_int(&conn->patched_ref), conn->bsc); |
| bsc_mgcp_dlcx(conn); |
| llist_del(&conn->list_entry); |
| talloc_free(conn); |
| } |
| |
| |
| int bsc_nat_find_paging(struct msgb *msg, |
| const uint8_t **out_data, int *out_leng) |
| { |
| int data_length; |
| const uint8_t *data; |
| struct tlv_parsed tp; |
| |
| if (!msg->l3h || msgb_l3len(msg) < 3) { |
| LOGP(DNAT, LOGL_ERROR, "Paging message is too short.\n"); |
| return -1; |
| } |
| |
| tlv_parse(&tp, gsm0808_att_tlvdef(), msg->l3h + 3, msgb_l3len(msg) - 3, 0, 0); |
| if (!TLVP_PRESENT(&tp, GSM0808_IE_CELL_IDENTIFIER_LIST)) { |
| LOGP(DNAT, LOGL_ERROR, "No CellIdentifier List inside paging msg.\n"); |
| return -2; |
| } |
| |
| data_length = TLVP_LEN(&tp, GSM0808_IE_CELL_IDENTIFIER_LIST); |
| data = TLVP_VAL(&tp, GSM0808_IE_CELL_IDENTIFIER_LIST); |
| |
| /* No need to try a different BSS */ |
| if (data[0] == CELL_IDENT_BSS) { |
| return -3; |
| } else if (data[0] != CELL_IDENT_LAC) { |
| LOGP(DNAT, LOGL_ERROR, "Unhandled cell ident discrminator: %d\n", data[0]); |
| return -4; |
| } |
| |
| *out_data = &data[1]; |
| *out_leng = data_length - 1; |
| return 0; |
| } |
| |
| int bsc_write_mgcp(struct bsc_connection *bsc, const uint8_t *data, unsigned int length) |
| { |
| struct msgb *msg; |
| |
| if (length > 4096 - 128) { |
| LOGP(DINP, LOGL_ERROR, "Can not send message of that size.\n"); |
| return -1; |
| } |
| |
| msg = msgb_alloc_headroom(4096, 128, "to-bsc"); |
| if (!msg) { |
| LOGP(DINP, LOGL_ERROR, "Failed to allocate memory for BSC msg.\n"); |
| return -1; |
| } |
| |
| /* copy the data */ |
| msg->l3h = msgb_put(msg, length); |
| memcpy(msg->l3h, data, length); |
| |
| return bsc_write(bsc, msg, IPAC_PROTO_MGCP_OLD); |
| } |
| |
| int bsc_write(struct bsc_connection *bsc, struct msgb *msg, int proto) |
| { |
| return bsc_do_write(&bsc->write_queue, msg, proto); |
| } |
| |
| int bsc_do_write(struct osmo_wqueue *queue, struct msgb *msg, int proto) |
| { |
| /* prepend the header */ |
| ipaccess_prepend_header(msg, proto); |
| return bsc_write_msg(queue, msg); |
| } |
| |
| int bsc_write_msg(struct osmo_wqueue *queue, struct msgb *msg) |
| { |
| if (osmo_wqueue_enqueue(queue, msg) != 0) { |
| LOGP(DINP, LOGL_ERROR, "Failed to enqueue the write.\n"); |
| msgb_free(msg); |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| int bsc_nat_lst_check_allow(struct bsc_nat_acc_lst *lst, const char *mi_string) |
| { |
| struct bsc_nat_acc_lst_entry *entry; |
| |
| llist_for_each_entry(entry, &lst->fltr_list, list) { |
| if (!entry->imsi_allow) |
| continue; |
| if (regexec(&entry->imsi_allow_re, mi_string, 0, NULL, 0) == 0) |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| static int lst_check_deny(struct bsc_nat_acc_lst *lst, const char *mi_string) |
| { |
| struct bsc_nat_acc_lst_entry *entry; |
| |
| llist_for_each_entry(entry, &lst->fltr_list, list) { |
| if (!entry->imsi_deny) |
| continue; |
| if (regexec(&entry->imsi_deny_re, mi_string, 0, NULL, 0) == 0) |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| /* apply white/black list */ |
| static int auth_imsi(struct bsc_connection *bsc, const char *mi_string) |
| { |
| /* |
| * Now apply blacklist/whitelist of the BSC and the NAT. |
| * 1.) Allow directly if the IMSI is allowed at the BSC |
| * 2.) Reject if the IMSI is not allowed at the BSC |
| * 3.) Reject if the IMSI not allowed at the global level. |
| * 4.) Allow directly if the IMSI is allowed at the global level |
| */ |
| struct bsc_nat_acc_lst *nat_lst = NULL; |
| struct bsc_nat_acc_lst *bsc_lst = NULL; |
| |
| bsc_lst = bsc_nat_acc_lst_find(bsc->nat, bsc->cfg->acc_lst_name); |
| nat_lst = bsc_nat_acc_lst_find(bsc->nat, bsc->nat->acc_lst_name); |
| |
| |
| if (bsc_lst) { |
| /* 1. BSC allow */ |
| if (bsc_nat_lst_check_allow(bsc_lst, mi_string) == 0) |
| return 1; |
| |
| /* 2. BSC deny */ |
| if (lst_check_deny(bsc_lst, mi_string) == 0) { |
| LOGP(DNAT, LOGL_ERROR, |
| "Filtering %s by imsi_deny on bsc nr: %d.\n", mi_string, bsc->cfg->nr); |
| rate_ctr_inc(&bsc_lst->stats->ctr[ACC_LIST_BSC_FILTER]); |
| return -2; |
| } |
| |
| } |
| |
| /* 3. NAT deny */ |
| if (nat_lst) { |
| if (lst_check_deny(nat_lst, mi_string) == 0) { |
| LOGP(DNAT, LOGL_ERROR, |
| "Filtering %s by nat imsi_deny on bsc nr: %d.\n", mi_string, bsc->cfg->nr); |
| rate_ctr_inc(&nat_lst->stats->ctr[ACC_LIST_NAT_FILTER]); |
| return -3; |
| } |
| } |
| |
| return 1; |
| } |
| |
| static int _cr_check_loc_upd(struct bsc_connection *bsc, |
| uint8_t *data, unsigned int length, |
| char **imsi) |
| { |
| uint8_t mi_type; |
| struct gsm48_loc_upd_req *lu; |
| char mi_string[GSM48_MI_SIZE]; |
| |
| if (length < sizeof(*lu)) { |
| LOGP(DNAT, LOGL_ERROR, |
| "LU does not fit. Length is %d \n", length); |
| return -1; |
| } |
| |
| lu = (struct gsm48_loc_upd_req *) data; |
| mi_type = lu->mi[0] & GSM_MI_TYPE_MASK; |
| |
| /* |
| * We can only deal with the IMSI. This will fail for a phone that |
| * will send the TMSI of a previous network to us. |
| */ |
| if (mi_type != GSM_MI_TYPE_IMSI) |
| return 0; |
| |
| gsm48_mi_to_string(mi_string, sizeof(mi_string), lu->mi, lu->mi_len); |
| *imsi = talloc_strdup(bsc, mi_string); |
| return auth_imsi(bsc, mi_string); |
| } |
| |
| static int _cr_check_cm_serv_req(struct bsc_connection *bsc, |
| uint8_t *data, unsigned int length, |
| int *con_type, char **imsi) |
| { |
| static const uint32_t classmark_offset = |
| offsetof(struct gsm48_service_request, classmark); |
| |
| char mi_string[GSM48_MI_SIZE]; |
| uint8_t mi_type; |
| int rc; |
| struct gsm48_service_request *req; |
| |
| /* unfortunately in Phase1 the classmark2 length is variable */ |
| |
| if (length < sizeof(*req)) { |
| LOGP(DNAT, LOGL_ERROR, |
| "CM Serv Req does not fit. Length is %d\n", length); |
| return -1; |
| } |
| |
| req = (struct gsm48_service_request *) data; |
| if (req->cm_service_type == 0x8) |
| *con_type = NAT_CON_TYPE_SSA; |
| rc = gsm48_extract_mi((uint8_t *) &req->classmark, |
| length - classmark_offset, mi_string, &mi_type); |
| if (rc < 0) { |
| LOGP(DNAT, LOGL_ERROR, "Failed to parse the classmark2/mi. error: %d\n", rc); |
| return -1; |
| } |
| |
| /* we have to let the TMSI or such pass */ |
| if (mi_type != GSM_MI_TYPE_IMSI) |
| return 0; |
| |
| *imsi = talloc_strdup(bsc, mi_string); |
| return auth_imsi(bsc, mi_string); |
| } |
| |
| static int _cr_check_pag_resp(struct bsc_connection *bsc, |
| uint8_t *data, unsigned int length, |
| char **imsi) |
| { |
| struct gsm48_pag_resp *resp; |
| char mi_string[GSM48_MI_SIZE]; |
| uint8_t mi_type; |
| |
| if (length < sizeof(*resp)) { |
| LOGP(DNAT, LOGL_ERROR, "PAG RESP does not fit. Length was %d.\n", length); |
| return -1; |
| } |
| |
| resp = (struct gsm48_pag_resp *) data; |
| if (gsm48_paging_extract_mi(resp, length, mi_string, &mi_type) < 0) { |
| LOGP(DNAT, LOGL_ERROR, "Failed to extract the MI.\n"); |
| return -1; |
| } |
| |
| /* we need to let it pass for now */ |
| if (mi_type != GSM_MI_TYPE_IMSI) |
| return 0; |
| |
| *imsi = talloc_strdup(bsc, mi_string); |
| return auth_imsi(bsc, mi_string); |
| } |
| |
| static int _dt_check_id_resp(struct bsc_connection *bsc, |
| uint8_t *data, unsigned int length, |
| struct sccp_connections *con) |
| { |
| char mi_string[GSM48_MI_SIZE]; |
| uint8_t mi_type; |
| int ret; |
| |
| if (length < 2) { |
| LOGP(DNAT, LOGL_ERROR, "mi does not fit.\n"); |
| return -1; |
| } |
| |
| if (data[0] < length - 1) { |
| LOGP(DNAT, LOGL_ERROR, "mi length too big.\n"); |
| return -2; |
| } |
| |
| mi_type = data[1] & GSM_MI_TYPE_MASK; |
| gsm48_mi_to_string(mi_string, sizeof(mi_string), &data[1], data[0]); |
| |
| if (mi_type != GSM_MI_TYPE_IMSI) |
| return 0; |
| |
| ret = auth_imsi(bsc, mi_string); |
| con->imsi_checked = 1; |
| con->imsi = talloc_strdup(con, mi_string); |
| return ret; |
| } |
| |
| /* Filter out CR data... */ |
| int bsc_nat_filter_sccp_cr(struct bsc_connection *bsc, struct msgb *msg, |
| struct bsc_nat_parsed *parsed, int *con_type, |
| char **imsi) |
| { |
| struct tlv_parsed tp; |
| struct gsm48_hdr *hdr48; |
| int hdr48_len; |
| int len; |
| uint8_t msg_type, proto; |
| |
| *con_type = NAT_CON_TYPE_NONE; |
| *imsi = NULL; |
| |
| if (parsed->gsm_type != BSS_MAP_MSG_COMPLETE_LAYER_3) { |
| LOGP(DNAT, LOGL_ERROR, |
| "Rejecting CR message due wrong GSM Type %d\n", parsed->gsm_type); |
| return -1; |
| } |
| |
| /* the parsed has had some basic l3 length check */ |
| len = msg->l3h[1]; |
| if (msgb_l3len(msg) - 3 < len) { |
| LOGP(DNAT, LOGL_ERROR, |
| "The CR Data has not enough space...\n"); |
| return -1; |
| } |
| |
| msg->l4h = &msg->l3h[3]; |
| len -= 1; |
| |
| tlv_parse(&tp, gsm0808_att_tlvdef(), msg->l4h, len, 0, 0); |
| |
| if (!TLVP_PRESENT(&tp, GSM0808_IE_LAYER_3_INFORMATION)) { |
| LOGP(DNAT, LOGL_ERROR, "CR Data does not contain layer3 information.\n"); |
| return -1; |
| } |
| |
| hdr48_len = TLVP_LEN(&tp, GSM0808_IE_LAYER_3_INFORMATION); |
| |
| if (hdr48_len < sizeof(*hdr48)) { |
| LOGP(DNAT, LOGL_ERROR, "GSM48 header does not fit.\n"); |
| return -1; |
| } |
| |
| hdr48 = (struct gsm48_hdr *) TLVP_VAL(&tp, GSM0808_IE_LAYER_3_INFORMATION); |
| |
| proto = hdr48->proto_discr & 0x0f; |
| msg_type = hdr48->msg_type & 0xbf; |
| if (proto == GSM48_PDISC_MM && |
| msg_type == GSM48_MT_MM_LOC_UPD_REQUEST) { |
| *con_type = NAT_CON_TYPE_LU; |
| return _cr_check_loc_upd(bsc, &hdr48->data[0], hdr48_len - sizeof(*hdr48), imsi); |
| } else if (proto == GSM48_PDISC_MM && |
| msg_type == GSM48_MT_MM_CM_SERV_REQ) { |
| *con_type = NAT_CON_TYPE_CM_SERV_REQ; |
| return _cr_check_cm_serv_req(bsc, &hdr48->data[0], |
| hdr48_len - sizeof(*hdr48), |
| con_type, imsi); |
| } else if (proto == GSM48_PDISC_RR && |
| msg_type == GSM48_MT_RR_PAG_RESP) { |
| *con_type = NAT_CON_TYPE_PAG_RESP; |
| return _cr_check_pag_resp(bsc, &hdr48->data[0], hdr48_len - sizeof(*hdr48), imsi); |
| } else { |
| /* We only want to filter the above, let other things pass */ |
| *con_type = NAT_CON_TYPE_OTHER; |
| return 0; |
| } |
| } |
| |
| struct gsm48_hdr *bsc_unpack_dtap(struct bsc_nat_parsed *parsed, |
| struct msgb *msg, uint32_t *len) |
| { |
| /* gsm_type is actually the size of the dtap */ |
| *len = parsed->gsm_type; |
| if (*len < msgb_l3len(msg) - 3) { |
| LOGP(DNAT, LOGL_ERROR, "Not enough space for DTAP.\n"); |
| return NULL; |
| } |
| |
| if (*len < sizeof(struct gsm48_hdr)) { |
| LOGP(DNAT, LOGL_ERROR, "GSM48 header does not fit.\n"); |
| return NULL; |
| } |
| |
| msg->l4h = &msg->l3h[3]; |
| return (struct gsm48_hdr *) msg->l4h; |
| } |
| |
| int bsc_nat_filter_dt(struct bsc_connection *bsc, struct msgb *msg, |
| struct sccp_connections *con, struct bsc_nat_parsed *parsed) |
| { |
| uint32_t len; |
| uint8_t msg_type, proto; |
| struct gsm48_hdr *hdr48; |
| |
| if (con->imsi_checked) |
| return 0; |
| |
| /* only care about DTAP messages */ |
| if (parsed->bssap != BSSAP_MSG_DTAP) |
| return 0; |
| |
| hdr48 = bsc_unpack_dtap(parsed, msg, &len); |
| if (!hdr48) |
| return -1; |
| |
| proto = hdr48->proto_discr & 0x0f; |
| msg_type = hdr48->msg_type & 0xbf; |
| if (proto == GSM48_PDISC_MM && |
| msg_type == GSM48_MT_MM_ID_RESP) { |
| return _dt_check_id_resp(bsc, &hdr48->data[0], len - sizeof(*hdr48), con); |
| } else { |
| return 0; |
| } |
| } |
| |
| int bsc_parse_reg(void *ctx, regex_t *reg, char **imsi, int argc, const char **argv) |
| { |
| int ret; |
| |
| ret = 0; |
| if (*imsi) { |
| talloc_free(*imsi); |
| *imsi = NULL; |
| } |
| regfree(reg); |
| |
| if (argc > 0) { |
| *imsi = talloc_strdup(ctx, argv[0]); |
| ret = regcomp(reg, argv[0], 0); |
| |
| /* handle compilation failures */ |
| if (ret != 0) { |
| talloc_free(*imsi); |
| *imsi = NULL; |
| } |
| } |
| |
| return ret; |
| } |
| |
| static const char *con_types [] = { |
| [NAT_CON_TYPE_NONE] = "n/a", |
| [NAT_CON_TYPE_LU] = "Location Update", |
| [NAT_CON_TYPE_CM_SERV_REQ] = "CM Serv Req", |
| [NAT_CON_TYPE_PAG_RESP] = "Paging Response", |
| [NAT_CON_TYPE_SSA] = "Supplementar Service Activation", |
| [NAT_CON_TYPE_LOCAL_REJECT] = "Local Reject", |
| [NAT_CON_TYPE_OTHER] = "Other", |
| }; |
| |
| const char *bsc_con_type_to_string(int type) |
| { |
| return con_types[type]; |
| } |
| |
| struct bsc_nat_acc_lst *bsc_nat_acc_lst_find(struct bsc_nat *nat, const char *name) |
| { |
| struct bsc_nat_acc_lst *lst; |
| |
| if (!name) |
| return NULL; |
| |
| llist_for_each_entry(lst, &nat->access_lists, list) |
| if (strcmp(lst->name, name) == 0) |
| return lst; |
| |
| return NULL; |
| } |
| |
| struct bsc_nat_acc_lst *bsc_nat_acc_lst_get(struct bsc_nat *nat, const char *name) |
| { |
| struct bsc_nat_acc_lst *lst; |
| |
| lst = bsc_nat_acc_lst_find(nat, name); |
| if (lst) |
| return lst; |
| |
| lst = talloc_zero(nat, struct bsc_nat_acc_lst); |
| if (!lst) { |
| LOGP(DNAT, LOGL_ERROR, "Failed to allocate access list"); |
| return NULL; |
| } |
| |
| /* TODO: get the index right */ |
| lst->stats = rate_ctr_group_alloc(lst, &bsc_cfg_acc_list_desc, 0); |
| if (!lst->stats) { |
| talloc_free(lst); |
| return NULL; |
| } |
| |
| INIT_LLIST_HEAD(&lst->fltr_list); |
| lst->name = talloc_strdup(lst, name); |
| llist_add_tail(&lst->list, &nat->access_lists); |
| return lst; |
| } |
| |
| void bsc_nat_acc_lst_delete(struct bsc_nat_acc_lst *lst) |
| { |
| llist_del(&lst->list); |
| rate_ctr_group_free(lst->stats); |
| talloc_free(lst); |
| } |
| |
| struct bsc_nat_acc_lst_entry *bsc_nat_acc_lst_entry_create(struct bsc_nat_acc_lst *lst) |
| { |
| struct bsc_nat_acc_lst_entry *entry; |
| |
| entry = talloc_zero(lst, struct bsc_nat_acc_lst_entry); |
| if (!entry) |
| return NULL; |
| |
| llist_add_tail(&entry->list, &lst->fltr_list); |
| return entry; |
| } |
| |
| int bsc_nat_msc_is_connected(struct bsc_nat *nat) |
| { |
| return nat->msc_con->is_connected; |
| } |
| |
| static const int con_to_ctr[] = { |
| [NAT_CON_TYPE_NONE] = -1, |
| [NAT_CON_TYPE_LU] = BCFG_CTR_CON_TYPE_LU, |
| [NAT_CON_TYPE_CM_SERV_REQ] = BCFG_CTR_CON_CMSERV_RQ, |
| [NAT_CON_TYPE_PAG_RESP] = BCFG_CTR_CON_PAG_RESP, |
| [NAT_CON_TYPE_SSA] = BCFG_CTR_CON_SSA, |
| [NAT_CON_TYPE_LOCAL_REJECT] = -1, |
| [NAT_CON_TYPE_OTHER] = BCFG_CTR_CON_OTHER, |
| }; |
| |
| int bsc_conn_type_to_ctr(struct sccp_connections *conn) |
| { |
| return con_to_ctr[conn->con_type]; |
| } |
| |
| int bsc_write_cb(struct osmo_fd *bfd, struct msgb *msg) |
| { |
| int rc; |
| |
| rc = write(bfd->fd, msg->data, msg->len); |
| if (rc != msg->len) |
| LOGP(DNAT, LOGL_ERROR, "Failed to write message to the BSC.\n"); |
| |
| return rc; |
| } |
| |
| static char *rewrite_non_international(struct bsc_nat *nat, void *ctx, const char *imsi, |
| struct gsm_mncc_number *called) |
| { |
| struct bsc_nat_num_rewr_entry *entry; |
| char *new_number = NULL; |
| |
| if (llist_empty(&nat->num_rewr)) |
| return NULL; |
| |
| if (called->plan != 1) |
| return NULL; |
| if (called->type == 1) |
| return NULL; |
| |
| /* need to find a replacement and then fix it */ |
| llist_for_each_entry(entry, &nat->num_rewr, list) { |
| regmatch_t matches[2]; |
| |
| /* check the IMSI match */ |
| if (regexec(&entry->msisdn_reg, imsi, 0, NULL, 0) != 0) |
| continue; |
| |
| /* this regexp matches... */ |
| if (regexec(&entry->num_reg, called->number, 2, matches, 0) == 0 && |
| matches[1].rm_eo != -1) |
| new_number = talloc_asprintf(ctx, "%s%s", |
| entry->replace, |
| &called->number[matches[1].rm_so]); |
| if (new_number) |
| break; |
| } |
| |
| return new_number; |
| } |
| |
| |
| /** |
| * Rewrite non global numbers... according to rules based on the IMSI |
| */ |
| static struct msgb *rewrite_setup(struct bsc_nat *nat, struct msgb *msg, |
| struct bsc_nat_parsed *parsed, const char *imsi, |
| struct gsm48_hdr *hdr48, const uint32_t len) |
| { |
| struct tlv_parsed tp; |
| unsigned int payload_len; |
| struct gsm_mncc_number called; |
| struct msgb *out; |
| char *new_number = NULL; |
| uint8_t *outptr; |
| const uint8_t *msgptr; |
| int sec_len; |
| |
| /* decode and rewrite the message */ |
| payload_len = len - sizeof(*hdr48); |
| tlv_parse(&tp, &gsm48_att_tlvdef, hdr48->data, payload_len, 0, 0); |
| |
| /* no number, well let us ignore it */ |
| if (!TLVP_PRESENT(&tp, GSM48_IE_CALLED_BCD)) |
| return NULL; |
| |
| memset(&called, 0, sizeof(called)); |
| gsm48_decode_called(&called, |
| TLVP_VAL(&tp, GSM48_IE_CALLED_BCD) - 1); |
| |
| /* check if it looks international and stop */ |
| new_number = rewrite_non_international(nat, msg, imsi, &called); |
| |
| if (!new_number) { |
| LOGP(DNAT, LOGL_DEBUG, "No IMSI match found, returning message.\n"); |
| return NULL; |
| } |
| |
| if (strlen(new_number) > sizeof(called.number)) { |
| LOGP(DNAT, LOGL_ERROR, "Number is too long for structure.\n"); |
| talloc_free(new_number); |
| return NULL; |
| } |
| |
| /* |
| * Need to create a new message now based on the old onew |
| * with a new number. We can sadly not patch this in place |
| * so we will need to regenerate it. |
| */ |
| |
| out = msgb_alloc_headroom(4096, 128, "changed-setup"); |
| if (!out) { |
| LOGP(DNAT, LOGL_ERROR, "Failed to allocate.\n"); |
| talloc_free(new_number); |
| return NULL; |
| } |
| |
| /* copy the header */ |
| outptr = msgb_put(out, sizeof(*hdr48)); |
| memcpy(outptr, hdr48, sizeof(*hdr48)); |
| |
| /* copy everything up to the number */ |
| sec_len = TLVP_VAL(&tp, GSM48_IE_CALLED_BCD) - 2 - &hdr48->data[0]; |
| outptr = msgb_put(out, sec_len); |
| memcpy(outptr, &hdr48->data[0], sec_len); |
| |
| /* create the new number */ |
| if (strncmp(new_number, "00", 2) == 0) { |
| called.type = 1; |
| strncpy(called.number, new_number + 2, sizeof(called.number)); |
| } else { |
| strncpy(called.number, new_number, sizeof(called.number)); |
| } |
| gsm48_encode_called(out, &called); |
| |
| /* copy thre rest */ |
| msgptr = TLVP_VAL(&tp, GSM48_IE_CALLED_BCD) + |
| TLVP_LEN(&tp, GSM48_IE_CALLED_BCD); |
| sec_len = payload_len - (msgptr - &hdr48->data[0]); |
| outptr = msgb_put(out, sec_len); |
| memcpy(outptr, msgptr, sec_len); |
| |
| talloc_free(new_number); |
| return out; |
| } |
| |
| static struct msgb *rewrite_smsc(struct bsc_nat *nat, struct msgb *msg, |
| struct bsc_nat_parsed *parsed, const char *imsi, |
| struct gsm48_hdr *hdr48, const uint32_t len) |
| { |
| unsigned int payload_len; |
| unsigned int cp_len; |
| |
| uint8_t ref; |
| uint8_t orig_addr_len, *orig_addr_ptr; |
| uint8_t dest_addr_len, *dest_addr_ptr; |
| uint8_t data_len, *data_ptr; |
| char smsc_addr[30]; |
| uint8_t new_addr[12]; |
| |
| |
| uint8_t dest_len; |
| char _dest_nr[30]; |
| char *dest_nr; |
| uint8_t dest_match = 0; |
| |
| struct bsc_nat_num_rewr_entry *entry; |
| char *new_number = NULL; |
| uint8_t new_addr_len; |
| struct gsm48_hdr *new_hdr48; |
| struct msgb *out; |
| |
| payload_len = len - sizeof(*hdr48); |
| if (payload_len < 1) { |
| LOGP(DNAT, LOGL_ERROR, "SMS too short for things. %d\n", payload_len); |
| return NULL; |
| } |
| |
| cp_len = hdr48->data[0]; |
| if (payload_len + 1 < cp_len) { |
| LOGP(DNAT, LOGL_ERROR, "SMS RPDU can not fit in: %d %d\n", cp_len, payload_len); |
| return NULL; |
| } |
| |
| if (hdr48->data[1] != GSM411_MT_RP_DATA_MO) |
| return NULL; |
| |
| if (cp_len < 5) { |
| LOGP(DNAT, LOGL_ERROR, "RD-DATA can not fit in the CP len: %d\n", cp_len); |
| return NULL; |
| } |
| |
| ref = hdr48->data[2]; |
| orig_addr_len = hdr48->data[3]; |
| orig_addr_ptr = &hdr48->data[4]; |
| |
| /* the +1 is for checking if the following element has some space */ |
| if (cp_len < 3 + orig_addr_len + 1) { |
| LOGP(DNAT, LOGL_ERROR, "RP-Originator addr does not fit: %d\n", orig_addr_len); |
| return NULL; |
| } |
| |
| dest_addr_len = hdr48->data[3 + orig_addr_len + 1]; |
| dest_addr_ptr = &hdr48->data[3 + orig_addr_len + 2]; |
| |
| if (cp_len < 3 + orig_addr_len + 1 + dest_addr_len + 1) { |
| LOGP(DNAT, LOGL_ERROR, "RP-Destination addr does not fit: %d\n", dest_addr_len); |
| return NULL; |
| } |
| gsm48_decode_bcd_number(smsc_addr, ARRAY_SIZE(smsc_addr), dest_addr_ptr - 1, 1); |
| |
| data_len = hdr48->data[3 + orig_addr_len + 1 + dest_addr_len + 1]; |
| data_ptr = &hdr48->data[3 + orig_addr_len + 1 + dest_addr_len + 2]; |
| |
| if (cp_len < 3 + orig_addr_len + 1 + dest_addr_len + 1 + data_len) { |
| LOGP(DNAT, LOGL_ERROR, "RP-Data does not fit: %d\n", data_len); |
| return NULL; |
| } |
| |
| /* look into the phone number */ |
| if ((data_ptr[0] & 0x01) != 1) |
| return NULL; |
| |
| if (data_len < 3) { |
| LOGP(DNAT, LOGL_ERROR, "SMS-SUBMIT is too short.\n"); |
| return NULL; |
| } |
| |
| dest_len = data_ptr[2]; |
| if (data_len < dest_len + 3 || dest_len < 2) { |
| LOGP(DNAT, LOGL_ERROR, "SMS-SUBMIT can not have TP-DestAddr.\n"); |
| return NULL; |
| } |
| |
| if ((data_ptr[3] & 0x80) == 0) { |
| LOGP(DNAT, LOGL_ERROR, "TP-DestAddr has extension. Not handled.\n"); |
| return NULL; |
| } |
| |
| if ((data_ptr[3] & 0x0F) == 0) { |
| LOGP(DNAT, LOGL_ERROR, "TP-DestAddr is not a ISDN number.\n"); |
| return NULL; |
| } |
| |
| gsm48_decode_bcd_number(_dest_nr + 2, ARRAY_SIZE(_dest_nr) - 2, |
| &data_ptr[2], 1); |
| if ((data_ptr[3] & 0x70) == 0x10) { |
| _dest_nr[0] = _dest_nr[1] = '0'; |
| dest_nr = &_dest_nr[0]; |
| } else { |
| dest_nr = &_dest_nr[2]; |
| } |
| |
| /* We will find a new number now */ |
| llist_for_each_entry(entry, &nat->smsc_rewr, list) { |
| regmatch_t matches[2]; |
| |
| /* check the IMSI match */ |
| if (regexec(&entry->msisdn_reg, imsi, 0, NULL, 0) != 0) |
| continue; |
| |
| /* this regexp matches... */ |
| if (regexec(&entry->num_reg, smsc_addr, 2, matches, 0) == 0 && |
| matches[1].rm_eo != -1) |
| new_number = talloc_asprintf(msg, "%s%s", |
| entry->replace, |
| &smsc_addr[matches[1].rm_so]); |
| if (new_number) |
| break; |
| } |
| |
| if (!new_number) |
| return NULL; |
| |
| /* |
| * now match the number against another list |
| */ |
| llist_for_each_entry(entry, &nat->tpdest_match, list) { |
| /* check the IMSI match */ |
| if (regexec(&entry->msisdn_reg, imsi, 0, NULL, 0) != 0) |
| continue; |
| |
| if (regexec(&entry->num_reg, dest_nr, 0, NULL, 0) == 0) { |
| dest_match =1; |
| break; |
| } |
| } |
| |
| if (!dest_match) { |
| talloc_free(new_number); |
| return NULL; |
| } |
| |
| /* |
| * We need to re-create the patched structure. This is why we have |
| * saved the above pointers. |
| */ |
| out = msgb_alloc_headroom(4096, 128, "changed-smsc"); |
| if (!out) { |
| LOGP(DNAT, LOGL_ERROR, "Failed to allocate.\n"); |
| return NULL; |
| } |
| |
| out->l3h = out->data; |
| msgb_v_put(out, GSM411_MT_RP_DATA_MO); |
| msgb_v_put(out, ref); |
| msgb_lv_put(out, orig_addr_len, orig_addr_ptr); |
| |
| /* |
| * Copy the new number. We let libosmocore encode it, then set |
| * the extension followed after the length. For our convenience |
| * we let the TLV code re-add the length so we start copying |
| * from &new_addr[1]. |
| */ |
| new_addr_len = gsm48_encode_bcd_number(new_addr, ARRAY_SIZE(new_addr), |
| 1, new_number); |
| new_addr[1] = 0x91; |
| msgb_lv_put(out, new_addr_len - 1, new_addr + 1); |
| |
| msgb_lv_put(out, data_len, data_ptr); |
| |
| new_hdr48 = (struct gsm48_hdr *) msgb_push(out, sizeof(*hdr48) + 1); |
| memcpy(new_hdr48, hdr48, sizeof(*hdr48)); |
| new_hdr48->data[0] = msgb_l3len(out); |
| |
| talloc_free(new_number); |
| return out; |
| } |
| |
| struct msgb *bsc_nat_rewrite_msg(struct bsc_nat *nat, struct msgb *msg, struct bsc_nat_parsed *parsed, const char *imsi) |
| { |
| struct gsm48_hdr *hdr48; |
| uint32_t len; |
| uint8_t msg_type, proto; |
| struct msgb *new_msg = NULL, *sccp; |
| |
| if (!imsi || strlen(imsi) < 5) |
| return msg; |
| |
| /* only care about DTAP messages */ |
| if (parsed->bssap != BSSAP_MSG_DTAP) |
| return msg; |
| if (!parsed->dest_local_ref) |
| return msg; |
| |
| hdr48 = bsc_unpack_dtap(parsed, msg, &len); |
| if (!hdr48) |
| return msg; |
| |
| proto = hdr48->proto_discr & 0x0f; |
| msg_type = hdr48->msg_type & 0xbf; |
| |
| if (proto == GSM48_PDISC_CC && msg_type == GSM48_MT_CC_SETUP) |
| new_msg = rewrite_setup(nat, msg, parsed, imsi, hdr48, len); |
| else if (proto == GSM48_PDISC_SMS && msg_type == GSM411_MT_CP_DATA) |
| new_msg = rewrite_smsc(nat, msg, parsed, imsi, hdr48, len); |
| |
| if (!new_msg) |
| return msg; |
| |
| /* wrap with DTAP, SCCP, then IPA. TODO: Stop copying */ |
| gsm0808_prepend_dtap_header(new_msg, 0); |
| sccp = sccp_create_dt1(parsed->dest_local_ref, new_msg->data, new_msg->len); |
| talloc_free(new_msg); |
| |
| if (!sccp) { |
| LOGP(DNAT, LOGL_ERROR, "Failed to allocate.\n"); |
| return msg; |
| } |
| |
| ipaccess_prepend_header(sccp, IPAC_PROTO_SCCP); |
| |
| /* the parsed hangs off from msg but it needs to survive */ |
| talloc_steal(sccp, parsed); |
| msgb_free(msg); |
| return sccp; |
| } |
| |
| static void num_rewr_free_data(struct bsc_nat_num_rewr_entry *entry) |
| { |
| regfree(&entry->msisdn_reg); |
| regfree(&entry->num_reg); |
| talloc_free(entry->replace); |
| } |
| |
| void bsc_nat_num_rewr_entry_adapt(void *ctx, struct llist_head *head, |
| const struct osmo_config_list *list) |
| { |
| struct bsc_nat_num_rewr_entry *entry, *tmp; |
| struct osmo_config_entry *cfg_entry; |
| |
| /* free the old data */ |
| llist_for_each_entry_safe(entry, tmp, head, list) { |
| num_rewr_free_data(entry); |
| llist_del(&entry->list); |
| talloc_free(entry); |
| } |
| |
| |
| if (!list) |
| return; |
| |
| llist_for_each_entry(cfg_entry, &list->entry, list) { |
| char *regexp; |
| if (cfg_entry->text[0] == '+') { |
| LOGP(DNAT, LOGL_ERROR, |
| "Plus is not allowed in the number\n"); |
| continue; |
| } |
| |
| entry = talloc_zero(ctx, struct bsc_nat_num_rewr_entry); |
| if (!entry) { |
| LOGP(DNAT, LOGL_ERROR, |
| "Allication of the num_rewr entry failed.\n"); |
| continue; |
| } |
| |
| entry->replace = talloc_strdup(entry, cfg_entry->text); |
| if (!entry->replace) { |
| LOGP(DNAT, LOGL_ERROR, |
| "Failed to copy the replacement text.\n"); |
| talloc_free(entry); |
| continue; |
| } |
| |
| /* we will now build a regexp string */ |
| if (cfg_entry->mcc[0] == '^') { |
| regexp = talloc_strdup(entry, cfg_entry->mcc); |
| } else { |
| regexp = talloc_asprintf(entry, "^%s%s", |
| cfg_entry->mcc[0] == '*' ? |
| "[0-9][0-9][0-9]" : cfg_entry->mcc, |
| cfg_entry->mnc[0] == '*' ? |
| "[0-9][0-9]" : cfg_entry->mnc); |
| } |
| |
| if (!regexp) { |
| LOGP(DNAT, LOGL_ERROR, "Failed to create a regexp string.\n"); |
| talloc_free(entry); |
| continue; |
| } |
| |
| if (regcomp(&entry->msisdn_reg, regexp, 0) != 0) { |
| LOGP(DNAT, LOGL_ERROR, |
| "Failed to compile regexp '%s'\n", regexp); |
| talloc_free(regexp); |
| talloc_free(entry); |
| continue; |
| } |
| |
| talloc_free(regexp); |
| if (regcomp(&entry->num_reg, cfg_entry->option, REG_EXTENDED) != 0) { |
| LOGP(DNAT, LOGL_ERROR, |
| "Failed to compile regexp '%s\n'", cfg_entry->option); |
| regfree(&entry->msisdn_reg); |
| talloc_free(entry); |
| continue; |
| } |
| |
| /* we have copied the number */ |
| llist_add_tail(&entry->list, head); |
| } |
| } |