diff options
Diffstat (limited to 'src/osmo-bsc_nat/bsc_nat.c')
| -rw-r--r-- | src/osmo-bsc_nat/bsc_nat.c | 1736 |
1 files changed, 1736 insertions, 0 deletions
diff --git a/src/osmo-bsc_nat/bsc_nat.c b/src/osmo-bsc_nat/bsc_nat.c new file mode 100644 index 000000000..daa066d05 --- /dev/null +++ b/src/osmo-bsc_nat/bsc_nat.c @@ -0,0 +1,1736 @@ +/* BSC Multiplexer/NAT */ + +/* + * (C) 2010-2013 by Holger Hans Peter Freyther <zecke@selfish.org> + * (C) 2010-2013 by On-Waves + * (C) 2009 by Harald Welte <laforge@gnumonks.org> + * 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 <sys/socket.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <netinet/in.h> +#include <netinet/tcp.h> +#include <arpa/inet.h> + +#include <errno.h> +#include <signal.h> +#include <stdio.h> +#include <stdlib.h> +#include <time.h> +#include <unistd.h> +#include <fcntl.h> +#include <libgen.h> + +#define _GNU_SOURCE +#include <getopt.h> + +#include <openbsc/debug.h> +#include <openbsc/bsc_msc.h> +#include <openbsc/bsc_nat.h> +#include <openbsc/bsc_nat_sccp.h> +#include <openbsc/bsc_msg_filter.h> +#include <openbsc/ipaccess.h> +#include <openbsc/abis_nm.h> +#include <openbsc/socket.h> +#include <openbsc/vty.h> + +#include <osmocom/ctrl/control_cmd.h> +#include <osmocom/ctrl/control_if.h> +#include <osmocom/ctrl/ports.h> +#include <osmocom/ctrl/control_vty.h> + +#include <osmocom/crypt/auth.h> + +#include <osmocom/core/application.h> +#include <osmocom/core/talloc.h> +#include <osmocom/core/stats.h> + +#include <osmocom/gsm/tlv.h> +#include <osmocom/gsm/gsm0808.h> +#include <osmocom/gsm/protocol/gsm_08_08.h> + +#include <osmocom/vty/telnet_interface.h> +#include <osmocom/vty/vty.h> +#include <osmocom/vty/logging.h> +#include <osmocom/vty/stats.h> +#include <osmocom/vty/ports.h> + +#include <osmocom/sccp/sccp.h> + +#include <osmocom/abis/ipa.h> + +#include <openssl/rand.h> + +#include "../../bscconfig.h" + +#define SCCP_CLOSE_TIME 20 +#define SCCP_CLOSE_TIME_TIMEOUT 19 + +static const char *config_file = "bsc-nat.cfg"; +static struct in_addr local_addr; +static struct osmo_fd bsc_listen; +static const char *msc_ip = NULL; +static struct osmo_timer_list sccp_close; +static int daemonize = 0; + +const char *openbsc_copyright = + "Copyright (C) 2010 Holger Hans Peter Freyther and On-Waves\r\n" + "License AGPLv3+: GNU AGPL version 3 or later <http://gnu.org/licenses/agpl-3.0.html>\r\n" + "This is free software: you are free to change and redistribute it.\r\n" + "There is NO WARRANTY, to the extent permitted by law.\r\n"; + +static struct bsc_nat *nat; +static void bsc_send_data(struct bsc_connection *bsc, const uint8_t *data, unsigned int length, int); +static void msc_send_reset(struct bsc_msc_connection *con); +static void bsc_stat_reject(int filter, struct bsc_connection *bsc, int normal); + +struct bsc_config *bsc_config_num(struct bsc_nat *nat, int num) +{ + struct bsc_config *conf; + + llist_for_each_entry(conf, &nat->bsc_configs, entry) + if (conf->nr == num) + return conf; + + return NULL; +} + +static void queue_for_msc(struct bsc_msc_connection *con, struct msgb *msg) +{ + if (!con) { + LOGP(DLINP, LOGL_ERROR, "No MSC Connection assigned. Check your code.\n"); + msgb_free(msg); + return; + } + + + if (osmo_wqueue_enqueue(&con->write_queue, msg) != 0) { + LOGP(DLINP, LOGL_ERROR, "Failed to enqueue the write.\n"); + msgb_free(msg); + } +} + +static void send_reset_ack(struct bsc_connection *bsc) +{ + static const uint8_t gsm_reset_ack[] = { + 0x09, 0x00, 0x03, 0x07, 0x0b, 0x04, 0x43, 0x01, + 0x00, 0xfe, 0x04, 0x43, 0x5c, 0x00, 0xfe, 0x03, + 0x00, 0x01, 0x31, + }; + + bsc_send_data(bsc, gsm_reset_ack, sizeof(gsm_reset_ack), IPAC_PROTO_SCCP); +} + +static void send_ping(struct bsc_connection *bsc) +{ + static const uint8_t id_ping[] = { + IPAC_MSGT_PING, + }; + + bsc_send_data(bsc, id_ping, sizeof(id_ping), IPAC_PROTO_IPACCESS); +} + +static void send_pong(struct bsc_connection *bsc) +{ + static const uint8_t id_pong[] = { + IPAC_MSGT_PONG, + }; + + bsc_send_data(bsc, id_pong, sizeof(id_pong), IPAC_PROTO_IPACCESS); +} + +static void bsc_pong_timeout(void *_bsc) +{ + struct bsc_connection *bsc = _bsc; + + LOGP(DNAT, LOGL_ERROR, "BSC Nr: %d PONG timeout.\n", bsc->cfg->nr); + bsc_close_connection(bsc); +} + +static void bsc_ping_timeout(void *_bsc) +{ + struct bsc_connection *bsc = _bsc; + + if (bsc->nat->ping_timeout < 0) + return; + + send_ping(bsc); + + /* send another ping in 20 seconds */ + osmo_timer_schedule(&bsc->ping_timeout, bsc->nat->ping_timeout, 0); + + /* also start a pong timer */ + osmo_timer_schedule(&bsc->pong_timeout, bsc->nat->pong_timeout, 0); +} + +static void start_ping_pong(struct bsc_connection *bsc) +{ + osmo_timer_setup(&bsc->pong_timeout, bsc_pong_timeout, bsc); + osmo_timer_setup(&bsc->ping_timeout, bsc_ping_timeout, bsc); + + bsc_ping_timeout(bsc); +} + +static void send_id_ack(struct bsc_connection *bsc) +{ + static const uint8_t id_ack[] = { + IPAC_MSGT_ID_ACK + }; + + bsc_send_data(bsc, id_ack, sizeof(id_ack), IPAC_PROTO_IPACCESS); +} + +static void send_id_req(struct bsc_nat *nat, struct bsc_connection *bsc) +{ + static const uint8_t s_id_req[] = { + IPAC_MSGT_ID_GET, + 0x01, IPAC_IDTAG_UNIT, + 0x01, IPAC_IDTAG_MACADDR, + 0x01, IPAC_IDTAG_LOCATION1, + 0x01, IPAC_IDTAG_LOCATION2, + 0x01, IPAC_IDTAG_EQUIPVERS, + 0x01, IPAC_IDTAG_SWVERSION, + 0x01, IPAC_IDTAG_UNITNAME, + 0x01, IPAC_IDTAG_SERNR, + }; + + uint8_t *mrand; + uint8_t id_req[sizeof(s_id_req) + (2+16)]; + uint8_t *buf = &id_req[sizeof(s_id_req)]; + + /* copy the static data */ + memcpy(id_req, s_id_req, sizeof(s_id_req)); + + /* put the RAND with length, tag, value */ + buf = v_put(buf, 0x11); + buf = v_put(buf, 0x23); + mrand = bsc->last_rand; + + if (RAND_bytes(mrand, 16) != 1) + goto failed_random; + + memcpy(buf, mrand, 16); + buf += 16; + + bsc_send_data(bsc, id_req, sizeof(id_req), IPAC_PROTO_IPACCESS); + return; + +failed_random: + /* the timeout will trigger and close this connection */ + LOGP(DNAT, LOGL_ERROR, "Failed to read from urandom.\n"); + return; +} + +static struct msgb *nat_create_rlsd(struct nat_sccp_connection *conn) +{ + struct sccp_connection_released *rel; + struct msgb *msg; + + msg = msgb_alloc_headroom(4096, 128, "rlsd"); + if (!msg) { + LOGP(DNAT, LOGL_ERROR, "Failed to allocate released.\n"); + return NULL; + } + + msg->l2h = msgb_put(msg, sizeof(*rel)); + rel = (struct sccp_connection_released *) msg->l2h; + rel->type = SCCP_MSG_TYPE_RLSD; + rel->release_cause = SCCP_RELEASE_CAUSE_SCCP_FAILURE; + rel->destination_local_reference = conn->remote_ref; + rel->source_local_reference = conn->patched_ref; + + return msg; +} + +static void nat_send_rlsd_ussd(struct bsc_nat *nat, struct nat_sccp_connection *conn) +{ + struct msgb *msg; + + if (!nat->ussd_con) + return; + + msg = nat_create_rlsd(conn); + if (!msg) + return; + + bsc_do_write(&nat->ussd_con->queue, msg, IPAC_PROTO_SCCP); +} + +static void nat_send_rlsd_msc(struct nat_sccp_connection *conn) +{ + struct msgb *msg; + + msg = nat_create_rlsd(conn); + if (!msg) + return; + + ipa_prepend_header(msg, IPAC_PROTO_SCCP); + queue_for_msc(conn->msc_con, msg); +} + +static void nat_send_rlsd_bsc(struct nat_sccp_connection *conn) +{ + struct msgb *msg; + struct sccp_connection_released *rel; + + msg = msgb_alloc_headroom(4096, 128, "rlsd"); + if (!msg) { + LOGP(DNAT, LOGL_ERROR, "Failed to allocate clear command.\n"); + return; + } + + msg->l2h = msgb_put(msg, sizeof(*rel)); + rel = (struct sccp_connection_released *) msg->l2h; + rel->type = SCCP_MSG_TYPE_RLSD; + rel->release_cause = SCCP_RELEASE_CAUSE_SCCP_FAILURE; + rel->destination_local_reference = conn->real_ref; + rel->source_local_reference = conn->remote_ref; + + bsc_write(conn->bsc, msg, IPAC_PROTO_SCCP); +} + +static struct msgb *nat_creat_clrc(struct nat_sccp_connection *conn, uint8_t cause) +{ + struct msgb *msg; + struct msgb *sccp; + + msg = gsm0808_create_clear_command(cause); + if (!msg) { + LOGP(DNAT, LOGL_ERROR, "Failed to allocate clear command.\n"); + return NULL; + } + + sccp = sccp_create_dt1(&conn->real_ref, msg->data, msg->len); + if (!sccp) { + LOGP(DNAT, LOGL_ERROR, "Failed to allocate SCCP msg.\n"); + msgb_free(msg); + return NULL; + } + + msgb_free(msg); + return sccp; +} + +static int nat_send_clrc_bsc(struct nat_sccp_connection *conn) +{ + struct msgb *sccp; + + sccp = nat_creat_clrc(conn, 0x20); + if (!sccp) + return -1; + return bsc_write(conn->bsc, sccp, IPAC_PROTO_SCCP); +} + +static void nat_send_rlc(struct bsc_msc_connection *msc_con, + struct sccp_source_reference *src, + struct sccp_source_reference *dst) +{ + struct sccp_connection_release_complete *rlc; + struct msgb *msg; + + msg = msgb_alloc_headroom(4096, 128, "rlc"); + if (!msg) { + LOGP(DNAT, LOGL_ERROR, "Failed to sccp rlc.\n"); + return; + } + + msg->l2h = msgb_put(msg, sizeof(*rlc)); + rlc = (struct sccp_connection_release_complete *) msg->l2h; + rlc->type = SCCP_MSG_TYPE_RLC; + rlc->destination_local_reference = *dst; + rlc->source_local_reference = *src; + + ipa_prepend_header(msg, IPAC_PROTO_SCCP); + + queue_for_msc(msc_con, msg); +} + +static void send_mgcp_reset(struct bsc_connection *bsc) +{ + static const uint8_t mgcp_reset[] = { + "RSIP 1 13@mgw MGCP 1.0\r\n" + }; + + bsc_write_mgcp(bsc, mgcp_reset, sizeof mgcp_reset - 1); +} + +void bsc_nat_send_mgcp_to_msc(struct bsc_nat *nat, struct msgb *msg) +{ + ipa_prepend_header(msg, IPAC_PROTO_MGCP_OLD); + queue_for_msc(nat->msc_con, msg); +} + +/* + * Below is the handling of messages coming + * from the MSC and need to be forwarded to + * a real BSC. + */ +static void initialize_msc_if_needed(struct bsc_msc_connection *msc_con) +{ + if (msc_con->first_contact) + return; + + msc_con->first_contact = 1; + msc_send_reset(msc_con); +} + +static void send_id_get_response(struct bsc_msc_connection *msc_con) +{ + struct msgb *msg = bsc_msc_id_get_resp(0, nat->token, NULL, 0); + if (!msg) + return; + + ipa_prepend_header(msg, IPAC_PROTO_IPACCESS); + queue_for_msc(msc_con, msg); +} + +/* + * Currently we are lacking refcounting so we need to copy each message. + */ +static void bsc_send_data(struct bsc_connection *bsc, const uint8_t *data, unsigned int length, int proto) +{ + struct msgb *msg; + + if (length > 4096 - 128) { + LOGP(DLINP, LOGL_ERROR, "Can not send message of that size.\n"); + return; + } + + msg = msgb_alloc_headroom(4096, 128, "to-bsc"); + if (!msg) { + LOGP(DLINP, LOGL_ERROR, "Failed to allocate memory for BSC msg.\n"); + return; + } + + msg->l2h = msgb_put(msg, length); + memcpy(msg->data, data, length); + + bsc_write(bsc, msg, proto); +} + +/* + * Update the release statistics + */ +static void bsc_stat_reject(int filter, struct bsc_connection *bsc, int normal) +{ + if (!bsc->cfg) { + LOGP(DNAT, LOGL_ERROR, "BSC is not authenticated."); + return; + } + + if (filter >= 0) { + LOGP(DNAT, LOGL_ERROR, "Connection was not rejected"); + return; + } + + if (filter == -1) + rate_ctr_inc(&bsc->cfg->stats.ctrg->ctr[BCFG_CTR_ILL_PACKET]); + else if (normal) + rate_ctr_inc(&bsc->cfg->stats.ctrg->ctr[BCFG_CTR_REJECTED_MSG]); + else + rate_ctr_inc(&bsc->cfg->stats.ctrg->ctr[BCFG_CTR_REJECTED_CR]); +} + +/* + * Release an established connection. We will have to release it to the BSC + * and to the network and we do it the following way. + * 1.) Give up on the MSC side + * 1.1) Send a RLSD message, it is a bit non standard but should work, we + * ignore the RLC... we might complain about it. Other options would + * be to send a Release Request, handle the Release Complete.. + * 1.2) Mark the data structure to be con_local and wait for 2nd + * + * 2.) Give up on the BSC side + * 2.1) Depending on the con type reject the service, or just close it + */ +static void bsc_send_con_release(struct bsc_connection *bsc, + struct nat_sccp_connection *con, + struct bsc_filter_reject_cause *cause) +{ + struct msgb *rlsd; + /* 1. release the network */ + rlsd = sccp_create_rlsd(&con->patched_ref, &con->remote_ref, + SCCP_RELEASE_CAUSE_END_USER_ORIGINATED); + if (!rlsd) + LOGP(DNAT, LOGL_ERROR, "Failed to create RLSD message.\n"); + else { + ipa_prepend_header(rlsd, IPAC_PROTO_SCCP); + queue_for_msc(con->msc_con, rlsd); + } + con->con_local = NAT_CON_END_LOCAL; + con->msc_con = NULL; + + /* 2. release the BSC side */ + if (con->filter_state.con_type == FLT_CON_TYPE_LU) { + struct msgb *payload, *udt; + payload = gsm48_create_loc_upd_rej(cause->lu_reject_cause); + + if (payload) { + gsm0808_prepend_dtap_header(payload, 0); + udt = sccp_create_dt1(&con->real_ref, payload->data, payload->len); + if (udt) + bsc_write(bsc, udt, IPAC_PROTO_SCCP); + else + LOGP(DNAT, LOGL_ERROR, "Failed to create DT1\n"); + + msgb_free(payload); + } else { + LOGP(DNAT, LOGL_ERROR, "Failed to allocate LU Reject.\n"); + } + } + + nat_send_clrc_bsc(con); + + rlsd = sccp_create_rlsd(&con->remote_ref, &con->real_ref, + SCCP_RELEASE_CAUSE_END_USER_ORIGINATED); + if (!rlsd) { + LOGP(DNAT, LOGL_ERROR, "Failed to allocate RLSD for the BSC.\n"); + sccp_connection_destroy(con); + return; + } + + con->filter_state.con_type = FLT_CON_TYPE_LOCAL_REJECT; + bsc_write(bsc, rlsd, IPAC_PROTO_SCCP); +} + +static void bsc_send_con_refuse(struct bsc_connection *bsc, + struct bsc_nat_parsed *parsed, int con_type, + struct bsc_filter_reject_cause *cause) +{ + struct msgb *payload; + struct msgb *refuse; + + if (con_type == FLT_CON_TYPE_LU) + payload = gsm48_create_loc_upd_rej(cause->lu_reject_cause); + else if (con_type == FLT_CON_TYPE_CM_SERV_REQ || con_type == FLT_CON_TYPE_SSA) + payload = gsm48_create_mm_serv_rej(cause->cm_reject_cause); + else { + LOGP(DNAT, LOGL_ERROR, "Unknown connection type: %d\n", con_type); + payload = NULL; + } + + /* + * Some BSCs do not handle the payload inside a SCCP CREF msg + * so we will need to: + * 1.) Allocate a local connection and mark it as local.. + * 2.) queue data for downstream.. and the RLC should delete everything + */ + if (payload) { + struct msgb *cc, *udt, *clear, *rlsd; + struct nat_sccp_connection *con; + con = create_sccp_src_ref(bsc, parsed); + if (!con) + goto send_refuse; + + /* declare it local and assign a unique remote_ref */ + con->filter_state.con_type = FLT_CON_TYPE_LOCAL_REJECT; + con->con_local = NAT_CON_END_LOCAL; + con->has_remote_ref = 1; + con->remote_ref = con->patched_ref; + + /* 1. create a confirmation */ + cc = sccp_create_cc(&con->remote_ref, &con->real_ref); + if (!cc) + goto send_refuse; + + /* 2. create the DT1 */ + gsm0808_prepend_dtap_header(payload, 0); + udt = sccp_create_dt1(&con->real_ref, payload->data, payload->len); + if (!udt) { + msgb_free(cc); + goto send_refuse; + } + + /* 3. send a Clear Command */ + clear = nat_creat_clrc(con, 0x20); + if (!clear) { + msgb_free(cc); + msgb_free(udt); + goto send_refuse; + } + + /* 4. send a RLSD */ + rlsd = sccp_create_rlsd(&con->remote_ref, &con->real_ref, + SCCP_RELEASE_CAUSE_END_USER_ORIGINATED); + if (!rlsd) { + msgb_free(cc); + msgb_free(udt); + msgb_free(clear); + goto send_refuse; + } + + bsc_write(bsc, cc, IPAC_PROTO_SCCP); + bsc_write(bsc, udt, IPAC_PROTO_SCCP); + bsc_write(bsc, clear, IPAC_PROTO_SCCP); + bsc_write(bsc, rlsd, IPAC_PROTO_SCCP); + msgb_free(payload); + return; + } + + +send_refuse: + if (payload) + msgb_free(payload); + + refuse = sccp_create_refuse(parsed->src_local_ref, + SCCP_REFUSAL_SCCP_FAILURE, NULL, 0); + if (!refuse) { + LOGP(DNAT, LOGL_ERROR, + "Creating refuse msg failed for SCCP 0x%x on BSC Nr: %d.\n", + sccp_src_ref_to_int(parsed->src_local_ref), bsc->cfg->nr); + return; + } + + bsc_write(bsc, refuse, IPAC_PROTO_SCCP); +} + +static void bsc_nat_send_paging(struct bsc_connection *bsc, struct msgb *msg) +{ + if (bsc->cfg->forbid_paging) { + LOGP(DNAT, LOGL_DEBUG, "Paging forbidden for BTS: %d\n", bsc->cfg->nr); + return; + } + + bsc_send_data(bsc, msg->l2h, msgb_l2len(msg), IPAC_PROTO_SCCP); +} + +static void bsc_nat_handle_paging(struct bsc_nat *nat, struct msgb *msg) +{ + struct bsc_connection *bsc; + const uint8_t *paging_start; + int paging_length, i, ret; + + ret = bsc_nat_find_paging(msg, &paging_start, &paging_length); + if (ret != 0) { + LOGP(DNAT, LOGL_ERROR, "Could not parse paging message: %d\n", ret); + return; + } + + /* This is quite expensive now */ + for (i = 0; i < paging_length; i += 2) { + unsigned int _lac = ntohs(*(unsigned int *) &paging_start[i]); + unsigned int paged = 0; + llist_for_each_entry(bsc, &nat->bsc_connections, list_entry) { + if (!bsc->cfg) + continue; + if (!bsc->authenticated) + continue; + if (!bsc_config_handles_lac(bsc->cfg, _lac)) + continue; + bsc_nat_send_paging(bsc, msg); + paged += 1; + } + + /* highlight a possible config issue */ + if (paged == 0) + LOGP(DNAT, LOGL_ERROR, "No BSC for LAC %d/0x%d\n", _lac, _lac); + + } +} + + +/* + * Update the auth status. This can be either a CIPHER MODE COMMAND or + * a CM Serivce Accept. Maybe also LU Accept or such in the future. + */ +static void update_con_authorize(struct nat_sccp_connection *con, + struct bsc_nat_parsed *parsed, + struct msgb *msg) +{ + if (!con) + return; + if (con->authorized) + return; + + if (parsed->bssap == BSSAP_MSG_BSS_MANAGEMENT && + parsed->gsm_type == BSS_MAP_MSG_CIPHER_MODE_CMD) { + con->authorized = 1; + } else if (parsed->bssap == BSSAP_MSG_DTAP) { + uint8_t msg_type, proto; + uint32_t len; + struct gsm48_hdr *hdr48; + hdr48 = bsc_unpack_dtap(parsed, msg, &len); + if (!hdr48) + return; + + proto = gsm48_hdr_pdisc(hdr48); + msg_type = gsm48_hdr_msg_type(hdr48); + if (proto == GSM48_PDISC_MM && + msg_type == GSM48_MT_MM_CM_SERV_ACC) + con->authorized = 1; + } +} + +static int forward_sccp_to_bts(struct bsc_msc_connection *msc_con, struct msgb *msg) +{ + struct nat_sccp_connection *con = NULL; + struct bsc_connection *bsc; + struct bsc_nat_parsed *parsed; + int proto; + + /* filter, drop, patch the message? */ + parsed = bsc_nat_parse(msg); + if (!parsed) { + LOGP(DNAT, LOGL_ERROR, "Can not parse msg from BSC.\n"); + return -1; + } + + if (bsc_nat_filter_ipa(DIR_BSC, msg, parsed)) + goto exit; + + proto = parsed->ipa_proto; + + /* Route and modify the SCCP packet */ + if (proto == IPAC_PROTO_SCCP) { + switch (parsed->sccp_type) { + case SCCP_MSG_TYPE_UDT: + /* forward UDT messages to every BSC */ + goto send_to_all; + break; + case SCCP_MSG_TYPE_RLSD: + case SCCP_MSG_TYPE_CREF: + case SCCP_MSG_TYPE_DT1: + case SCCP_MSG_TYPE_IT: + con = patch_sccp_src_ref_to_bsc(msg, parsed, nat); + if (parsed->gsm_type == BSS_MAP_MSG_ASSIGMENT_RQST) { + osmo_counter_inc(nat->stats.sccp.calls); + + if (con) { + struct rate_ctr_group *ctrg; + ctrg = con->bsc->cfg->stats.ctrg; + rate_ctr_inc(&ctrg->ctr[BCFG_CTR_SCCP_CALLS]); + if (bsc_mgcp_assign_patch(con, msg) != 0) + LOGP(DNAT, LOGL_ERROR, "Failed to assign...\n"); + } else + LOGP(DNAT, LOGL_ERROR, "Assignment command but no BSC.\n"); + } else if (con && con->con_local == NAT_CON_END_USSD && + parsed->gsm_type == BSS_MAP_MSG_CLEAR_CMD) { + LOGP(DNAT, LOGL_NOTICE, "Clear Command for USSD Connection. Ignoring.\n"); + con = NULL; + } + break; + case SCCP_MSG_TYPE_CC: + con = patch_sccp_src_ref_to_bsc(msg, parsed, nat); + if (!con || update_sccp_src_ref(con, parsed) != 0) + goto exit; + break; + case SCCP_MSG_TYPE_RLC: + LOGP(DNAT, LOGL_ERROR, "Unexpected release complete from MSC.\n"); + goto exit; + break; + case SCCP_MSG_TYPE_CR: + /* MSC never opens a SCCP connection, fall through */ + default: + goto exit; + } + + if (!con && parsed->sccp_type == SCCP_MSG_TYPE_RLSD) { + LOGP(DNAT, LOGL_NOTICE, "Sending fake RLC on RLSD message to network.\n"); + /* Exchange src/dest for the reply */ + nat_send_rlc(msc_con, &parsed->original_dest_ref, + parsed->src_local_ref); + } else if (!con) + LOGP(DNAT, LOGL_ERROR, "Unknown connection for msg type: 0x%x from the MSC.\n", parsed->sccp_type); + } + + if (!con) { + talloc_free(parsed); + return -1; + } + if (!con->bsc->authenticated) { + talloc_free(parsed); + LOGP(DNAT, LOGL_ERROR, "Selected BSC not authenticated.\n"); + return -1; + } + + update_con_authorize(con, parsed, msg); + talloc_free(parsed); + + bsc_send_data(con->bsc, msg->l2h, msgb_l2len(msg), proto); + return 0; + +send_to_all: + /* + * Filter Paging from the network. We do not want to send a PAGING + * Command to every BSC in our network. We will analys the PAGING + * message and then send it to the authenticated messages... + */ + if (parsed->ipa_proto == IPAC_PROTO_SCCP && parsed->gsm_type == BSS_MAP_MSG_PAGING) { + bsc_nat_handle_paging(nat, msg); + goto exit; + } + /* currently send this to every BSC connected */ + llist_for_each_entry(bsc, &nat->bsc_connections, list_entry) { + if (!bsc->authenticated) + continue; + + bsc_send_data(bsc, msg->l2h, msgb_l2len(msg), parsed->ipa_proto); + } + +exit: + talloc_free(parsed); + return 0; +} + +static void msc_connection_was_lost(struct bsc_msc_connection *con) +{ + struct bsc_connection *bsc, *tmp; + + LOGP(DMSC, LOGL_ERROR, "Closing all connections downstream.\n"); + llist_for_each_entry_safe(bsc, tmp, &nat->bsc_connections, list_entry) + bsc_close_connection(bsc); + + bsc_mgcp_free_endpoints(nat); + bsc_msc_schedule_connect(con); +} + +static void msc_connection_connected(struct bsc_msc_connection *con) +{ + osmo_counter_inc(nat->stats.msc.reconn); +} + +static void msc_send_reset(struct bsc_msc_connection *msc_con) +{ + static const uint8_t reset[] = { + 0x00, 0x12, 0xfd, + 0x09, 0x00, 0x03, 0x05, 0x07, 0x02, 0x42, 0xfe, + 0x02, 0x42, 0xfe, 0x06, 0x00, 0x04, 0x30, 0x04, + 0x01, 0x20 + }; + + struct msgb *msg; + + msg = msgb_alloc_headroom(4096, 128, "08.08 reset"); + if (!msg) { + LOGP(DMSC, LOGL_ERROR, "Failed to allocate reset msg.\n"); + return; + } + + msg->l2h = msgb_put(msg, sizeof(reset)); + memcpy(msg->l2h, reset, msgb_l2len(msg)); + + queue_for_msc(msc_con, msg); + + LOGP(DMSC, LOGL_NOTICE, "Scheduled GSM0808 reset msg for the MSC.\n"); +} + +static int ipaccess_msc_read_cb(struct osmo_fd *bfd) +{ + struct bsc_msc_connection *msc_con; + struct msgb *msg = NULL; + struct ipaccess_head *hh; + int ret; + + msc_con = (struct bsc_msc_connection *) bfd->data; + + ret = ipa_msg_recv_buffered(bfd->fd, &msg, &msc_con->pending_msg); + if (ret <= 0) { + if (ret == -EAGAIN) + return 0; + if (ret == 0) + LOGP(DNAT, LOGL_FATAL, + "The connection the MSC(%s) was lost, exiting\n", + msc_con->name); + else + LOGP(DNAT, LOGL_ERROR, + "Failed to parse ip access message on %s: %d\n", + msc_con->name, ret); + + bsc_msc_lost(msc_con); + return -1; + } + + LOGP(DNAT, LOGL_DEBUG, + "MSG from MSC(%s): %s proto: %d\n", msc_con->name, + osmo_hexdump(msg->data, msg->len), msg->l2h[0]); + + /* handle base message handling */ + hh = (struct ipaccess_head *) msg->data; + + /* initialize the networking. This includes sending a GSM08.08 message */ + if (hh->proto == IPAC_PROTO_IPACCESS) { + ipa_ccm_rcvmsg_base(msg, bfd); + if (msg->l2h[0] == IPAC_MSGT_ID_ACK) + initialize_msc_if_needed(msc_con); + else if (msg->l2h[0] == IPAC_MSGT_ID_GET) + send_id_get_response(msc_con); + } else if (hh->proto == IPAC_PROTO_SCCP) { + forward_sccp_to_bts(msc_con, msg); + } else if (hh->proto == IPAC_PROTO_MGCP_OLD) { + bsc_nat_handle_mgcp(nat, msg); + } + + msgb_free(msg); + return 0; +} + +static int ipaccess_msc_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 MSG to MSC.\n"); + return -1; + } + + return rc; +} + +/* + * Below is the handling of messages coming + * from the BSC and need to be forwarded to + * a real BSC. + */ + +/* + * Remove the connection from the connections list, + * remove it from the patching of SCCP header lists + * as well. Maybe in the future even close connection.. + */ +void bsc_close_connection(struct bsc_connection *connection) +{ + struct nat_sccp_connection *sccp_patch, *tmp; + struct bsc_cmd_list *cmd_entry, *cmd_tmp; + struct rate_ctr *ctr = NULL; + + /* stop the timeout timer */ + osmo_timer_del(&connection->id_timeout); + osmo_timer_del(&connection->ping_timeout); + osmo_timer_del(&connection->pong_timeout); + + if (connection->cfg) + ctr = &connection->cfg->stats.ctrg->ctr[BCFG_CTR_DROPPED_SCCP]; + + /* remove all SCCP connections */ + llist_for_each_entry_safe(sccp_patch, tmp, &nat->sccp_connections, list_entry) { + if (sccp_patch->bsc != connection) + continue; + + if (ctr) + rate_ctr_inc(ctr); + if (sccp_patch->has_remote_ref) { + if (sccp_patch->con_local == NAT_CON_END_MSC) + nat_send_rlsd_msc(sccp_patch); + else if (sccp_patch->con_local == NAT_CON_END_USSD) + nat_send_rlsd_ussd(nat, sccp_patch); + } + + sccp_connection_destroy(sccp_patch); + } + + /* Reply to all outstanding commands */ + llist_for_each_entry_safe(cmd_entry, cmd_tmp, &connection->cmd_pending, list_entry) { + cmd_entry->cmd->type = CTRL_TYPE_ERROR; + cmd_entry->cmd->reply = "BSC closed the connection"; + ctrl_cmd_send(&cmd_entry->ccon->write_queue, cmd_entry->cmd); + bsc_nat_ctrl_del_pending(cmd_entry); + } + + /* close endpoints allocated by this BSC */ + bsc_mgcp_clear_endpoints_for(connection); + + osmo_fd_unregister(&connection->write_queue.bfd); + close(connection->write_queue.bfd.fd); + osmo_wqueue_clear(&connection->write_queue); + llist_del(&connection->list_entry); + + if (connection->pending_msg) { + LOGP(DNAT, LOGL_ERROR, "Dropping partial message on connection %d.\n", + connection->cfg ? connection->cfg->nr : -1); + msgb_free(connection->pending_msg); + connection->pending_msg = NULL; + } + + talloc_free(connection); +} + +static void bsc_maybe_close(struct bsc_connection *bsc) +{ + struct nat_sccp_connection *sccp; + if (!bsc->nat->blocked) + return; + + /* are there any connections left */ + llist_for_each_entry(sccp, &bsc->nat->sccp_connections, list_entry) + if (sccp->bsc == bsc) + return; + + /* nothing left, close the BSC */ + LOGP(DNAT, LOGL_NOTICE, "Cleaning up BSC %d in blocking mode.\n", + bsc->cfg ? bsc->cfg->nr : -1); + bsc_close_connection(bsc); +} + +static void ipaccess_close_bsc(void *data) +{ + struct sockaddr_in sock; + socklen_t len = sizeof(sock); + struct bsc_connection *conn = data; + + + getpeername(conn->write_queue.bfd.fd, (struct sockaddr *) &sock, &len); + LOGP(DNAT, LOGL_ERROR, "BSC on %s didn't respond to identity request. Closing.\n", + inet_ntoa(sock.sin_addr)); + bsc_close_connection(conn); +} + +static int verify_key(struct bsc_connection *conn, struct bsc_config *conf, const uint8_t *key, const int keylen) +{ + struct osmo_auth_vector vec; + + struct osmo_sub_auth_data auth = { + .type = OSMO_AUTH_TYPE_GSM, + .algo = OSMO_AUTH_ALG_MILENAGE, + }; + + /* expect a specific keylen */ + if (keylen != 8) { + LOGP(DNAT, LOGL_ERROR, "Key length is wrong: %d for bsc nr %d\n", + keylen, conf->nr); + return 0; + } + + memcpy(auth.u.umts.opc, conf->key, 16); + memcpy(auth.u.umts.k, conf->key, 16); + memset(auth.u.umts.amf, 0, 2); + auth.u.umts.sqn = 0; + + memset(&vec, 0, sizeof(vec)); + osmo_auth_gen_vec(&vec, &auth, conn->last_rand); + + if (vec.res_len != 8) { + LOGP(DNAT, LOGL_ERROR, "Res length is wrong: %d for bsc nr %d\n", + vec.res_len, conf->nr); + return 0; + } + + return osmo_constant_time_cmp(vec.res, key, 8) == 0; +} + +static void ipaccess_auth_bsc(struct tlv_parsed *tvp, struct bsc_connection *bsc) +{ + struct bsc_config *conf; + const char *token = (const char *) TLVP_VAL(tvp, IPAC_IDTAG_UNITNAME); + int len = TLVP_LEN(tvp, IPAC_IDTAG_UNITNAME); + const uint8_t *xres = TLVP_VAL(tvp, 0x24); + const int xlen = TLVP_LEN(tvp, 0x24); + + if (bsc->cfg) { + LOGP(DNAT, LOGL_ERROR, "Reauth on fd %d bsc nr %d\n", + bsc->write_queue.bfd.fd, bsc->cfg->nr); + return; + } + + if (len <= 0) { + LOGP(DNAT, LOGL_ERROR, "Token with length zero on fd: %d\n", + bsc->write_queue.bfd.fd); + return; + } + + if (token[len - 1] != '\0') { + LOGP(DNAT, LOGL_ERROR, "Token not null terminated on fd: %d\n", + bsc->write_queue.bfd.fd); + return; + } + + /* + * New systems have fixed the structure of the message but + * we need to support old ones too. + */ + if (len >= 2 && token[len - 2] == '\0') + len -= 1; + + conf = bsc_config_by_token(bsc->nat, token, len); + if (!conf) { + LOGP(DNAT, LOGL_ERROR, + "No bsc found for token '%s' len %d on fd: %d.\n", token, + bsc->write_queue.bfd.fd, len); + bsc_close_connection(bsc); + return; + } + + /* We have set a key and expect it to be present */ + if (conf->key_present && !verify_key(bsc, conf, xres, xlen - 1)) { + LOGP(DNAT, LOGL_ERROR, + "Wrong key for bsc nr %d fd: %d.\n", conf->nr, + bsc->write_queue.bfd.fd); + bsc_close_connection(bsc); + return; + } + + rate_ctr_inc(&conf->stats.ctrg->ctr[BCFG_CTR_NET_RECONN]); + bsc->authenticated = 1; + bsc->cfg = conf; + osmo_timer_del(&bsc->id_timeout); + LOGP(DNAT, LOGL_NOTICE, "Authenticated bsc nr: %d on fd %d\n", + conf->nr, bsc->write_queue.bfd.fd); + start_ping_pong(bsc); +} + +static void handle_con_stats(struct nat_sccp_connection *con) +{ + struct rate_ctr_group *ctrg; + int id = bsc_conn_type_to_ctr(con); + + if (id == -1) + return; + + if (!con->bsc || !con->bsc->cfg) + return; + + ctrg = con->bsc->cfg->stats.ctrg; + rate_ctr_inc(&ctrg->ctr[id]); +} + +static int forward_sccp_to_msc(struct bsc_connection *bsc, struct msgb *msg) +{ + int con_filter = 0; + char *imsi = NULL; + struct bsc_msc_connection *con_msc = NULL; + struct bsc_connection *con_bsc = NULL; + int con_type; + struct bsc_nat_parsed *parsed; + struct bsc_filter_reject_cause cause; + + /* Parse and filter messages */ + parsed = bsc_nat_parse(msg); + if (!parsed) { + LOGP(DNAT, LOGL_ERROR, "Can not parse msg from BSC.\n"); + msgb_free(msg); + return -1; + } + + if (bsc_nat_filter_ipa(DIR_MSC, msg, parsed)) + goto exit; + + /* + * check authentication after filtering to not reject auth + * responses coming from the BSC. We have to make sure that + * nothing from the exit path will forward things to the MSC + */ + if (!bsc->authenticated) { + LOGP(DNAT, LOGL_ERROR, "BSC is not authenticated.\n"); + msgb_free(msg); + return -1; + } + + + /* modify the SCCP entries */ + if (parsed->ipa_proto == IPAC_PROTO_SCCP) { + int filter; + struct nat_sccp_connection *con; + switch (parsed->sccp_type) { + case SCCP_MSG_TYPE_CR: + memset(&cause, 0, sizeof(cause)); + filter = bsc_nat_filter_sccp_cr(bsc, msg, parsed, + &con_type, &imsi, &cause); + if (filter < 0) { + if (imsi) + bsc_nat_inform_reject(bsc, imsi); + bsc_stat_reject(filter, bsc, 0); + goto exit3; + } + + if (!create_sccp_src_ref(bsc, parsed)) + goto exit2; + con = patch_sccp_src_ref_to_msc(msg, parsed, bsc); + OSMO_ASSERT(con); + con->msc_con = bsc->nat->msc_con; + con_msc = con->msc_con; + con->filter_state.con_type = con_type; + con->filter_state.imsi_checked = filter; + bsc_nat_extract_lac(bsc, con, parsed, msg); + if (imsi) + con->filter_state.imsi = talloc_steal(con, imsi); + imsi = NULL; + con_bsc = con->bsc; + handle_con_stats(con); + break; + case SCCP_MSG_TYPE_RLSD: + case SCCP_MSG_TYPE_CREF: + case SCCP_MSG_TYPE_DT1: + case SCCP_MSG_TYPE_CC: + case SCCP_MSG_TYPE_IT: + con = patch_sccp_src_ref_to_msc(msg, parsed, bsc); + if (con) { + /* only filter non local connections */ + if (!con->con_local) { + memset(&cause, 0, sizeof(cause)); + filter = bsc_nat_filter_dt(bsc, msg, + con, parsed, &cause); + if (filter < 0) { + if (con->filter_state.imsi) + bsc_nat_inform_reject(bsc, + con->filter_state.imsi); + bsc_stat_reject(filter, bsc, 1); + bsc_send_con_release(bsc, con, &cause); + con = NULL; + goto exit2; + } + + /* hand data to a side channel */ + if (bsc_ussd_check(con, parsed, msg) == 1) + con->con_local = NAT_CON_END_USSD; + + /* + * Optionally rewrite setup message. This can + * replace the msg and the parsed structure becomes + * invalid. + */ + msg = bsc_nat_rewrite_msg(bsc->nat, msg, parsed, + con->filter_state.imsi); + talloc_free(parsed); + parsed = NULL; + } else if (con->con_local == NAT_CON_END_USSD) { + bsc_ussd_check(con, parsed, msg); + } + + con_bsc = con->bsc; + con_msc = con->msc_con; + con_filter = con->con_local; + } + + break; + case SCCP_MSG_TYPE_RLC: + con = patch_sccp_src_ref_to_msc(msg, parsed, bsc); + if (con) { + con_bsc = con->bsc; + con_msc = con->msc_con; + con_filter = con->con_local; + } + remove_sccp_src_ref(bsc, msg, parsed); + bsc_maybe_close(bsc); + break; + case SCCP_MSG_TYPE_UDT: + /* simply forward everything */ + con = NULL; + break; + default: + LOGP(DNAT, LOGL_ERROR, "Not forwarding to msc sccp type: 0x%x\n", parsed->sccp_type); + con = NULL; + goto exit2; + break; + } + } else if (parsed->ipa_proto == IPAC_PROTO_MGCP_OLD) { + bsc_mgcp_forward(bsc, msg); + goto exit2; + } else { + LOGP(DNAT, LOGL_ERROR, "Not forwarding unknown stream id: 0x%x\n", parsed->ipa_proto); + goto exit2; + } + + if (con_msc && con_bsc != bsc) { + LOGP(DNAT, LOGL_ERROR, "The connection belongs to a different BTS: input: %d con: %d\n", + bsc->cfg->nr, con_bsc->cfg->nr); + goto exit2; + } + + /* do not forward messages to the MSC */ + if (con_filter) + goto exit2; + + if (!con_msc) { + LOGP(DNAT, LOGL_ERROR, "Not forwarding data bsc_nr: %d ipa: %d type: 0x%x\n", + bsc->cfg->nr, + parsed ? parsed->ipa_proto : -1, + parsed ? parsed->sccp_type : -1); + goto exit2; + } + + /* send the non-filtered but maybe modified msg */ + queue_for_msc(con_msc, msg); + if (parsed) + talloc_free(parsed); + return 0; + +exit: + /* if we filter out the reset send an ack to the BSC */ + if (parsed->bssap == 0 && parsed->gsm_type == BSS_MAP_MSG_RESET) { + send_reset_ack(bsc); + send_reset_ack(bsc); + } else if (parsed->ipa_proto == IPAC_PROTO_IPACCESS) { + /* do we know who is handling this? */ + if (msg->l2h[0] == IPAC_MSGT_ID_RESP && msgb_l2len(msg) > 2) { + struct tlv_parsed tvp; + int ret; + ret = ipa_ccm_idtag_parse_off(&tvp, + (unsigned char *) msg->l2h + 2, + msgb_l2len(msg) - 2, 0); + if (ret < 0) { + LOGP(DNAT, LOGL_ERROR, "ignoring IPA response " + "message with malformed TLVs\n"); + return ret; + } + if (TLVP_PRESENT(&tvp, IPAC_IDTAG_UNITNAME)) + ipaccess_auth_bsc(&tvp, bsc); + } + + goto exit2; + } + +exit2: + if (imsi) + talloc_free(imsi); + talloc_free(parsed); + msgb_free(msg); + return -1; + +exit3: + /* send a SCCP Connection Refused */ + if (imsi) + talloc_free(imsi); + bsc_send_con_refuse(bsc, parsed, con_type, &cause); + talloc_free(parsed); + msgb_free(msg); + return -1; +} + +static int ipaccess_bsc_read_cb(struct osmo_fd *bfd) +{ + struct bsc_connection *bsc = bfd->data; + struct msgb *msg = NULL; + struct ipaccess_head *hh; + struct ipaccess_head_ext *hh_ext; + int ret; + + ret = ipa_msg_recv_buffered(bfd->fd, &msg, &bsc->pending_msg); + if (ret <= 0) { + if (ret == -EAGAIN) + return 0; + if (ret == 0) + LOGP(DNAT, LOGL_ERROR, + "The connection to the BSC Nr: %d was lost. Cleaning it\n", + bsc->cfg ? bsc->cfg->nr : -1); + else + LOGP(DNAT, LOGL_ERROR, + "Stream error on BSC Nr: %d. Failed to parse ip access message: %d (%s)\n", + bsc->cfg ? bsc->cfg->nr : -1, ret, strerror(-ret)); + + bsc_close_connection(bsc); + return -1; + } + + + LOGP(DNAT, LOGL_DEBUG, "MSG from BSC: %s proto: %d\n", osmo_hexdump(msg->data, msg->len), msg->l2h[0]); + + /* Handle messages from the BSC */ + hh = (struct ipaccess_head *) msg->data; + + /* stop the pong timeout */ + if (hh->proto == IPAC_PROTO_IPACCESS) { + if (msg->l2h[0] == IPAC_MSGT_PONG) { + osmo_timer_del(&bsc->pong_timeout); + msgb_free(msg); + return 0; + } else if (msg->l2h[0] == IPAC_MSGT_PING) { + send_pong(bsc); + msgb_free(msg); + return 0; + } + /* Message contains the ipaccess_head_ext header, investigate further */ + } else if (hh->proto == IPAC_PROTO_OSMO && + msg->len > sizeof(*hh) + sizeof(*hh_ext)) { + + hh_ext = (struct ipaccess_head_ext *) hh->data; + /* l2h is where the actual command data is expected */ + msg->l2h = hh_ext->data; + + if (hh_ext->proto == IPAC_PROTO_EXT_CTRL) + return bsc_nat_handle_ctrlif_msg(bsc, msg); + } + + /* FIXME: Currently no PONG is sent to the BSC */ + /* FIXME: Currently no ID ACK is sent to the BSC */ + forward_sccp_to_msc(bsc, msg); + + return 0; +} + +static int ipaccess_listen_bsc_cb(struct osmo_fd *bfd, unsigned int what) +{ + struct bsc_connection *bsc; + int fd, rc, on; + struct sockaddr_in sa; + socklen_t sa_len = sizeof(sa); + + if (!(what & BSC_FD_READ)) + return 0; + + fd = accept(bfd->fd, (struct sockaddr *) &sa, &sa_len); + if (fd < 0) { + perror("accept"); + return fd; + } + + /* count the reconnect */ + osmo_counter_inc(nat->stats.bsc.reconn); + + /* + * if we are not connected to a msc... just close the socket + */ + if (!bsc_nat_msc_is_connected(nat)) { + LOGP(DNAT, LOGL_NOTICE, "Disconnecting BSC due lack of MSC connection.\n"); + close(fd); + return 0; + } + + if (nat->blocked) { + LOGP(DNAT, LOGL_NOTICE, "Disconnecting BSC due NAT being blocked.\n"); + close(fd); + return 0; + } + + on = 1; + rc = setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &on, sizeof(on)); + if (rc != 0) + LOGP(DNAT, LOGL_ERROR, "Failed to set TCP_NODELAY: %s\n", strerror(errno)); + + rc = setsockopt(fd, IPPROTO_IP, IP_TOS, + &nat->bsc_ip_dscp, sizeof(nat->bsc_ip_dscp)); + if (rc != 0) + LOGP(DNAT, LOGL_ERROR, "Failed to set IP_TOS: %s\n", strerror(errno)); + + /* todo... do something with the connection */ + /* todo... use GNUtls to see if we want to trust this as a BTS */ + + /* + * + */ + bsc = bsc_connection_alloc(nat); + if (!bsc) { + LOGP(DNAT, LOGL_ERROR, "Failed to allocate BSC struct.\n"); + close(fd); + return -1; + } + + bsc->write_queue.bfd.data = bsc; + bsc->write_queue.bfd.fd = fd; + bsc->write_queue.read_cb = ipaccess_bsc_read_cb; + bsc->write_queue.write_cb = bsc_write_cb; + bsc->write_queue.bfd.when = BSC_FD_READ; + if (osmo_fd_register(&bsc->write_queue.bfd) < 0) { + LOGP(DNAT, LOGL_ERROR, "Failed to register BSC fd.\n"); + close(fd); + talloc_free(bsc); + return -2; + } + + LOGP(DNAT, LOGL_NOTICE, "BSC connection on %d with IP: %s\n", + fd, inet_ntoa(sa.sin_addr)); + + llist_add(&bsc->list_entry, &nat->bsc_connections); + bsc->last_id = 0; + + send_id_ack(bsc); + send_id_req(nat, bsc); + send_mgcp_reset(bsc); + + /* + * start the hangup timer + */ + osmo_timer_setup(&bsc->id_timeout, ipaccess_close_bsc, bsc); + osmo_timer_schedule(&bsc->id_timeout, nat->auth_timeout, 0); + return 0; +} + +static void print_usage() +{ + printf("Usage: bsc_nat\n"); +} + +static void print_help() +{ + printf(" Some useful help...\n"); + printf(" -h --help this text\n"); + printf(" -d option --debug=DRLL:DCC:DMM:DRR:DRSL:DNM enable debugging\n"); + printf(" -D --daemonize Fork the process into a background daemon\n"); + printf(" -s --disable-color\n"); + printf(" -c --config-file filename The config file to use.\n"); + printf(" -m --msc=IP. The address of the MSC.\n"); + printf(" -l --local=IP. The local address of this BSC.\n"); +} + +static void handle_options(int argc, char **argv) +{ + while (1) { + int option_index = 0, c; + static struct option long_options[] = { + {"help", 0, 0, 'h'}, + {"debug", 1, 0, 'd'}, + {"daemonize", 0, 0, 'D'}, + {"config-file", 1, 0, 'c'}, + {"disable-color", 0, 0, 's'}, + {"timestamp", 0, 0, 'T'}, + {"msc", 1, 0, 'm'}, + {"local", 1, 0, 'l'}, + {0, 0, 0, 0} + }; + + c = getopt_long(argc, argv, "hd:sTPc:m:l:D", + long_options, &option_index); + if (c == -1) + break; + + switch (c) { + case 'h': + print_usage(); + print_help(); + exit(0); + case 's': + log_set_use_color(osmo_stderr_target, 0); + break; + case 'd': + log_parse_category_mask(osmo_stderr_target, optarg); + break; + case 'D': + daemonize = 1; + break; + case 'c': + config_file = optarg; + break; + case 'T': + log_set_print_timestamp(osmo_stderr_target, 1); + break; + case 'm': + msc_ip = optarg; + break; + case 'l': + inet_aton(optarg, &local_addr); + break; + default: + /* ignore */ + break; + } + } +} + +static void signal_handler(int signal) +{ + switch (signal) { + case SIGABRT: + /* in case of abort, we want to obtain a talloc report + * and then return to the caller, who will abort the process */ + case SIGUSR1: + talloc_report_full(tall_bsc_ctx, stderr); + break; + default: + break; + } +} + +static void sccp_close_unconfirmed(void *_data) +{ + int destroyed = 0; + struct bsc_connection *bsc, *bsc_tmp; + struct nat_sccp_connection *conn, *tmp1; + struct timespec now; + clock_gettime(CLOCK_MONOTONIC, &now); + + llist_for_each_entry_safe(conn, tmp1, &nat->sccp_connections, list_entry) { + if (conn->has_remote_ref) + continue; + + int diff = (now.tv_sec - conn->creation_time.tv_sec) / 60; + if (diff < SCCP_CLOSE_TIME_TIMEOUT) + continue; + + LOGP(DNAT, LOGL_ERROR, + "SCCP connection 0x%x/0x%x was never confirmed on bsc nr. %d\n", + sccp_src_ref_to_int(&conn->real_ref), + sccp_src_ref_to_int(&conn->patched_ref), + conn->bsc->cfg->nr); + sccp_connection_destroy(conn); + destroyed = 1; + } + + if (!destroyed) + goto out; + + /* now close out any BSC */ + llist_for_each_entry_safe(bsc, bsc_tmp, &nat->bsc_connections, list_entry) + bsc_maybe_close(bsc); + +out: + osmo_timer_schedule(&sccp_close, SCCP_CLOSE_TIME, 0); +} + +extern void *tall_ctr_ctx; +static void talloc_init_ctx() +{ + tall_bsc_ctx = talloc_named_const(NULL, 0, "nat"); + msgb_talloc_ctx_init(tall_bsc_ctx, 0); + tall_ctr_ctx = talloc_named_const(tall_bsc_ctx, 0, "counter"); +} + +extern int bsc_vty_go_parent(struct vty *vty); + +static struct vty_app_info vty_info = { + .name = "OsmoBSCNAT", + .version = PACKAGE_VERSION, + .go_parent_cb = bsc_vty_go_parent, + .is_config_node = bsc_vty_is_config_node, +}; + + +int main(int argc, char **argv) +{ + int rc; + + talloc_init_ctx(); + + osmo_init_logging(&log_info); + + nat = bsc_nat_alloc(); + if (!nat) { + fprintf(stderr, "Failed to allocate the BSC nat.\n"); + return -4; + } + + nat->mgcp_cfg = mgcp_config_alloc(); + if (!nat->mgcp_cfg) { + fprintf(stderr, "Failed to allocate MGCP cfg.\n"); + return -5; + } + + /* We need to add mode-set for amr codecs */ + nat->sdp_ensure_amr_mode_set = 1; + + vty_info.copyright = openbsc_copyright; + vty_init(&vty_info); + logging_vty_add_cmds(NULL); + osmo_stats_vty_add_cmds(&log_info); + bsc_nat_vty_init(nat); + ctrl_vty_init(tall_bsc_ctx); + + + /* parse options */ + local_addr.s_addr = INADDR_ANY; + handle_options(argc, argv); + + nat->include_base = dirname(talloc_strdup(tall_bsc_ctx, config_file)); + + rate_ctr_init(tall_bsc_ctx); + osmo_stats_init(tall_bsc_ctx); + + /* init vty and parse */ + if (mgcp_parse_config(config_file, nat->mgcp_cfg, MGCP_BSC_NAT) < 0) { + fprintf(stderr, "Failed to parse the config file: '%s'\n", config_file); + return -3; + } + + /* start telnet after reading config for vty_get_bind_addr() */ + if (telnet_init_dynif(tall_bsc_ctx, NULL, vty_get_bind_addr(), + OSMO_VTY_PORT_BSC_NAT)) { + fprintf(stderr, "Creating VTY telnet line failed\n"); + return -5; + } + + /* over rule the VTY config for MSC IP */ + if (msc_ip) + bsc_nat_set_msc_ip(nat, msc_ip); + + /* seed the PRNG */ + srand(time(NULL)); + + LOGP(DNAT, LOGL_NOTICE, "BSCs configured from %s\n", nat->resolved_path); + + /* + * Setup the MGCP code.. + */ + if (bsc_mgcp_nat_init(nat) != 0) + return -4; + + /* connect to the MSC */ + nat->msc_con = bsc_msc_create(nat, &nat->dests); + if (!nat->msc_con) { + fprintf(stderr, "Creating a bsc_msc_connection failed.\n"); + exit(1); + } + + /* start control interface after reading config for + * ctrl_vty_get_bind_addr() */ + nat->ctrl = bsc_nat_controlif_setup(nat, ctrl_vty_get_bind_addr(), + OSMO_CTRL_PORT_BSC_NAT); + if (!nat->ctrl) { + fprintf(stderr, "Creating the control interface failed.\n"); + exit(1); + } + + nat->msc_con->name = "main MSC"; + nat->msc_con->connection_loss = msc_connection_was_lost; + nat->msc_con->connected = msc_connection_connected; + nat->msc_con->write_queue.read_cb = ipaccess_msc_read_cb; + nat->msc_con->write_queue.write_cb = ipaccess_msc_write_cb;; + nat->msc_con->write_queue.bfd.data = nat->msc_con; + bsc_msc_connect(nat->msc_con); + + /* wait for the BSC */ + rc = make_sock(&bsc_listen, IPPROTO_TCP, ntohl(local_addr.s_addr), + 5000, 0, ipaccess_listen_bsc_cb, nat); + if (rc != 0) { + fprintf(stderr, "Failed to listen for BSC.\n"); + exit(1); + } + + rc = bsc_ussd_init(nat); + if (rc != 0) { + LOGP(DNAT, LOGL_ERROR, "Failed to bind the USSD socket.\n"); + exit(1); + } + + signal(SIGABRT, &signal_handler); + signal(SIGUSR1, &signal_handler); + osmo_init_ignore_signals(); + + if (daemonize) { + rc = osmo_daemonize(); + if (rc < 0) { + perror("Error during daemonize"); + exit(1); + } + } + + /* recycle timer */ + sccp_set_log_area(DSCCP); + osmo_timer_setup(&sccp_close, sccp_close_unconfirmed, NULL); + osmo_timer_schedule(&sccp_close, SCCP_CLOSE_TIME, 0); + + while (1) { + osmo_select_main(0); + } + + return 0; +} + +/* Close all connections handed out to the USSD module */ +int bsc_ussd_close_connections(struct bsc_nat *nat) +{ + struct nat_sccp_connection *con; + llist_for_each_entry(con, &nat->sccp_connections, list_entry) { + if (con->con_local != NAT_CON_END_USSD) + continue; + if (!con->bsc) + continue; + + nat_send_clrc_bsc(con); + nat_send_rlsd_bsc(con); + } + + return 0; +} |