diff options
Diffstat (limited to 'src/osmo-bsc_nat/bsc_mgcp_utils.c')
-rw-r--r-- | src/osmo-bsc_nat/bsc_mgcp_utils.c | 1151 |
1 files changed, 0 insertions, 1151 deletions
diff --git a/src/osmo-bsc_nat/bsc_mgcp_utils.c b/src/osmo-bsc_nat/bsc_mgcp_utils.c deleted file mode 100644 index 49050fc89..000000000 --- a/src/osmo-bsc_nat/bsc_mgcp_utils.c +++ /dev/null @@ -1,1151 +0,0 @@ -/** - * This file contains helper routines for MGCP Gateway handling. - * - * The first thing to remember is that each BSC has its own namespace/range - * of endpoints. Whenever a BSSMAP ASSIGNMENT REQUEST is received this code - * will be called to select an endpoint on the BSC. The mapping from original - * multiplex/timeslot to BSC multiplex'/timeslot' will be stored. - * - * The second part is to take messages on the public MGCP GW interface - * and forward them to the right BSC. This requires the MSC to first - * assign the timeslot. This assumption has been true so far. We are using - * the policy_cb of the MGCP protocol code to decide if the request should - * be immediately answered or delayed. An extension "Z: noanswer" is used - * to request the BSC to not respond. This is saving some bytes of bandwidth - * and as we are using TCP to forward the message we know it will arrive. - * The mgcp_do_read method reads these messages and hands them to the protocol - * parsing code which will call the mentioned policy_cb. The bsc_mgcp_forward - * method is used on the way back from the BSC to the network. - * - * The third part is to patch messages forwarded to the BSC. This includes - * the endpoint number, the ports to be used inside the SDP file and maybe - * some other bits. - * - */ -/* - * (C) 2010-2012 by Holger Hans Peter Freyther <zecke@selfish.org> - * (C) 2010-2012 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_callstats.h> -#include <openbsc/bsc_nat_sccp.h> -#include <openbsc/gsm_data.h> -#include <openbsc/debug.h> -#include <openbsc/ipaccess.h> -#include <osmocom/legacy_mgcp/mgcp.h> -#include <osmocom/legacy_mgcp/mgcp_internal.h> -#include <openbsc/osmux.h> - -#include <osmocom/ctrl/control_cmd.h> - -#include <osmocom/sccp/sccp.h> - -#include <osmocom/core/talloc.h> -#include <osmocom/gsm/gsm0808.h> -#include <osmocom/gsm/protocol/gsm_08_08.h> - -#include <netinet/in.h> -#include <arpa/inet.h> - -#include <errno.h> -#include <unistd.h> - -static void send_direct(struct bsc_nat *nat, struct msgb *output) -{ - if (osmo_wqueue_enqueue(&nat->mgcp_cfg->gw_fd, output) != 0) { - LOGP(DMGCP, LOGL_ERROR, "Failed to queue MGCP msg.\n"); - msgb_free(output); - } -} - -static void mgcp_queue_for_call_agent(struct bsc_nat *nat, struct msgb *output) -{ - if (nat->mgcp_ipa) - bsc_nat_send_mgcp_to_msc(nat, output); - else - send_direct(nat, output); -} - -int bsc_mgcp_nr_multiplexes(int max_endpoints) -{ - int div = max_endpoints / 32; - - if ((max_endpoints % 32) != 0) - div += 1; - - return div; -} - -static int bsc_init_endps_if_needed(struct bsc_connection *con) -{ - int multiplexes; - - /* we have done that */ - if (con->_endpoint_status) - return 0; - - /* we have no config... */ - if (!con->cfg) - return -1; - - multiplexes = bsc_mgcp_nr_multiplexes(con->cfg->max_endpoints); - con->number_multiplexes = multiplexes; - con->max_endpoints = con->cfg->max_endpoints; - con->_endpoint_status = talloc_zero_array(con, char, 32 * multiplexes + 1); - return con->_endpoint_status == NULL; -} - -static int bsc_assign_endpoint(struct bsc_connection *bsc, struct nat_sccp_connection *con) -{ - int multiplex; - int timeslot; - const int number_endpoints = bsc->max_endpoints; - int i; - - mgcp_endpoint_to_timeslot(bsc->last_endpoint, &multiplex, ×lot); - timeslot += 1; - - for (i = 0; i < number_endpoints; ++i) { - int endpoint; - - /* Wrap around timeslots */ - if (timeslot == 0) - timeslot = 1; - - if (timeslot == 0x1f) { - timeslot = 1; - multiplex += 1; - } - - /* Wrap around the multiplex */ - if (multiplex >= bsc->number_multiplexes) - multiplex = 0; - - endpoint = mgcp_timeslot_to_endpoint(multiplex, timeslot); - - /* Now check if we are allowed to assign this one */ - if (endpoint >= bsc->max_endpoints) { - multiplex = 0; - timeslot = 1; - endpoint = mgcp_timeslot_to_endpoint(multiplex, timeslot); - } - - - if (bsc->_endpoint_status[endpoint] == 0) { - bsc->_endpoint_status[endpoint] = 1; - con->bsc_endp = endpoint; - bsc->last_endpoint = endpoint; - return 0; - } - - timeslot += 1; - } - - return -1; -} - -static uint16_t create_cic(int endpoint) -{ - int timeslot, multiplex; - - mgcp_endpoint_to_timeslot(endpoint, &multiplex, ×lot); - return (multiplex << 5) | (timeslot & 0x1f); -} - -int bsc_mgcp_assign_patch(struct nat_sccp_connection *con, struct msgb *msg) -{ - struct nat_sccp_connection *mcon; - struct tlv_parsed tp; - uint16_t cic; - uint8_t timeslot; - uint8_t multiplex; - unsigned int endp; - - if (!msg->l3h) { - LOGP(DNAT, LOGL_ERROR, "Assignment message should have l3h pointer.\n"); - return -1; - } - - if (msgb_l3len(msg) < 3) { - LOGP(DNAT, LOGL_ERROR, "Assignment message has not enough space for GSM0808.\n"); - return -1; - } - - tlv_parse(&tp, gsm0808_att_tlvdef(), msg->l3h + 3, msgb_l3len(msg) - 3, 0, 0); - if (!TLVP_PRESENT(&tp, GSM0808_IE_CIRCUIT_IDENTITY_CODE)) { - LOGP(DNAT, LOGL_ERROR, "Circuit identity code not found in assignment message.\n"); - return -1; - } - - cic = ntohs(tlvp_val16_unal(&tp, GSM0808_IE_CIRCUIT_IDENTITY_CODE)); - timeslot = cic & 0x1f; - multiplex = (cic & ~0x1f) >> 5; - - - endp = mgcp_timeslot_to_endpoint(multiplex, timeslot); - - if (endp >= con->bsc->nat->mgcp_cfg->trunk.number_endpoints) { - LOGP(DNAT, LOGL_ERROR, - "MSC attempted to assign bad endpoint 0x%x\n", - endp); - return -1; - } - - /* find stale connections using that endpoint */ - llist_for_each_entry(mcon, &con->bsc->nat->sccp_connections, list_entry) { - if (mcon->msc_endp == endp) { - LOGP(DNAT, LOGL_ERROR, - "Endpoint %d was assigned to 0x%x and now 0x%x\n", - endp, - sccp_src_ref_to_int(&mcon->patched_ref), - sccp_src_ref_to_int(&con->patched_ref)); - bsc_mgcp_dlcx(mcon); - } - } - - con->msc_endp = endp; - if (bsc_init_endps_if_needed(con->bsc) != 0) - return -1; - if (bsc_assign_endpoint(con->bsc, con) != 0) - return -1; - - /* - * now patch the message for the new CIC... - * still assumed to be one multiplex only - */ - cic = htons(create_cic(con->bsc_endp)); - memcpy((uint8_t *) TLVP_VAL(&tp, GSM0808_IE_CIRCUIT_IDENTITY_CODE), - &cic, sizeof(cic)); - - return 0; -} - -static void bsc_mgcp_free_endpoint(struct bsc_nat *nat, int i) -{ - if (nat->bsc_endpoints[i].transaction_id) { - talloc_free(nat->bsc_endpoints[i].transaction_id); - nat->bsc_endpoints[i].transaction_id = NULL; - } - - nat->bsc_endpoints[i].transaction_state = 0; - nat->bsc_endpoints[i].bsc = NULL; -} - -void bsc_mgcp_free_endpoints(struct bsc_nat *nat) -{ - int i; - - for (i = 1; i < nat->mgcp_cfg->trunk.number_endpoints; ++i){ - bsc_mgcp_free_endpoint(nat, i); - mgcp_release_endp(&nat->mgcp_cfg->trunk.endpoints[i]); - } -} - -/* send a MDCX where we do not want a response */ -static void bsc_mgcp_send_mdcx(struct bsc_connection *bsc, int port, struct mgcp_endpoint *endp) -{ - char buf[2096]; - int len; - - len = snprintf(buf, sizeof(buf), - "MDCX 23 %x@mgw MGCP 1.0\r\n" - "Z: noanswer\r\n" - "\r\n" - "c=IN IP4 %s\r\n" - "m=audio %d RTP/AVP 255\r\n", - port, mgcp_bts_src_addr(endp), - endp->bts_end.local_port); - if (len < 0) { - LOGP(DMGCP, LOGL_ERROR, "snprintf for MDCX failed.\n"); - return; - } - - bsc_write_mgcp(bsc, (uint8_t *) buf, len); -} - -static void bsc_mgcp_send_dlcx(struct bsc_connection *bsc, int endpoint, int trans) -{ - char buf[2096]; - int len; - - /* - * The following is a bit of a spec violation. According to the - * MGCP grammar the transaction id is are upto 9 digits but we - * prefix it with an alpha numeric value so we can easily recognize - * it as a response. - */ - len = snprintf(buf, sizeof(buf), - "DLCX nat-%u %x@mgw MGCP 1.0\r\n", - trans, endpoint); - if (len < 0) { - LOGP(DMGCP, LOGL_ERROR, "snprintf for DLCX failed.\n"); - return; - } - - bsc_write_mgcp(bsc, (uint8_t *) buf, len); -} - -void bsc_mgcp_init(struct nat_sccp_connection *con) -{ - con->msc_endp = -1; - con->bsc_endp = -1; -} - -/** - * This code will remember the network side of the audio statistics and - * once the internal DLCX response arrives this can be combined with the - * the BSC side and forwarded as a trap. - */ -static void remember_pending_dlcx(struct nat_sccp_connection *con, uint32_t transaction) -{ - struct bsc_nat_call_stats *stats; - struct bsc_connection *bsc = con->bsc; - struct mgcp_endpoint *endp; - - stats = talloc_zero(bsc, struct bsc_nat_call_stats); - if (!stats) { - LOGP(DNAT, LOGL_NOTICE, - "Failed to allocate statistics for endpoint 0x%x\n", - con->msc_endp); - return; - } - - /* take the endpoint here */ - endp = &bsc->nat->mgcp_cfg->trunk.endpoints[con->msc_endp]; - - stats->remote_ref = con->remote_ref; - stats->src_ref = con->patched_ref; - - stats->ci = endp->ci; - stats->bts_rtp_port = endp->bts_end.rtp_port; - stats->bts_addr = endp->bts_end.addr; - stats->net_rtp_port = endp->net_end.rtp_port; - stats->net_addr = endp->net_end.addr; - - stats->net_ps = endp->net_end.packets; - stats->net_os = endp->net_end.octets; - stats->bts_pr = endp->bts_end.packets; - stats->bts_or = endp->bts_end.octets; - mgcp_state_calc_loss(&endp->bts_state, &endp->bts_end, - &stats->bts_expected, &stats->bts_loss); - stats->bts_jitter = mgcp_state_calc_jitter(&endp->bts_state); - - stats->trans_id = transaction; - stats->msc_endpoint = con->msc_endp; - - /* - * Too many pending requests.. let's remove the first two items. - */ - if (!llist_empty(&bsc->pending_dlcx) && - bsc->pending_dlcx_count >= bsc->cfg->max_endpoints * 3) { - struct bsc_nat_call_stats *tmp; - LOGP(DNAT, LOGL_ERROR, - "Too many(%d) pending DLCX responses on BSC: %d\n", - bsc->pending_dlcx_count, bsc->cfg->nr); - bsc->pending_dlcx_count -= 1; - tmp = (struct bsc_nat_call_stats *) bsc->pending_dlcx.next; - llist_del(&tmp->entry); - talloc_free(tmp); - } - - bsc->pending_dlcx_count += 1; - llist_add_tail(&stats->entry, &bsc->pending_dlcx); -} - -void bsc_mgcp_dlcx(struct nat_sccp_connection *con) -{ - /* send a DLCX down the stream */ - if (con->bsc_endp != -1 && con->bsc->_endpoint_status) { - LOGP(DNAT, LOGL_NOTICE, - "Endpoint 0x%x was allocated for bsc: %d. Freeing it.\n", - con->bsc_endp, con->bsc->cfg->nr); - if (con->bsc->_endpoint_status[con->bsc_endp] != 1) - LOGP(DNAT, LOGL_ERROR, "Endpoint 0x%x was not in use\n", con->bsc_endp); - remember_pending_dlcx(con, con->bsc->next_transaction); - con->bsc->_endpoint_status[con->bsc_endp] = 0; - bsc_mgcp_send_dlcx(con->bsc, con->bsc_endp, con->bsc->next_transaction++); - bsc_mgcp_free_endpoint(con->bsc->nat, con->msc_endp); - } - - bsc_mgcp_init(con); - -} - -/* - * Search for the pending request - */ -static void handle_dlcx_response(struct bsc_connection *bsc, struct msgb *msg, - int code, const char *transaction) -{ - uint32_t trans_id = UINT32_MAX; - uint32_t b_ps, b_os, n_pr, n_or, jitter; - int loss; - struct bsc_nat_call_stats *tmp, *stat = NULL; - struct ctrl_cmd *cmd; - - /* parse the transaction identifier */ - int rc = sscanf(transaction, "nat-%u", &trans_id); - if (rc != 1) { - LOGP(DNAT, LOGL_ERROR, "Can not parse transaction id: '%s'\n", - transaction); - return; - } - - /* find the answer for the request we made */ - llist_for_each_entry(tmp, &bsc->pending_dlcx, entry) { - if (trans_id != tmp->trans_id) - continue; - - stat = tmp; - break; - } - - if (!stat) { - LOGP(DNAT, LOGL_ERROR, - "Can not find transaction for: %u\n", trans_id); - return; - } - - /* attempt to parse the data now */ - rc = mgcp_parse_stats(msg, &b_ps, &b_os, &n_pr, &n_or, &loss, &jitter); - if (rc != 0) - LOGP(DNAT, LOGL_ERROR, - "Can not parse connection statistics: %d\n", rc); - - /* send a trap now */ - cmd = ctrl_cmd_create(bsc, CTRL_TYPE_TRAP); - if (!cmd) { - LOGP(DNAT, LOGL_ERROR, - "Creating a ctrl cmd failed.\n"); - goto free_stat; - } - - cmd->id = "0"; - cmd->variable = talloc_asprintf(cmd, "net.0.bsc.%d.call_stats.v2", - bsc->cfg->nr); - cmd->reply = talloc_asprintf(cmd, - "mg_ip_addr=%s,mg_port=%d,", - inet_ntoa(stat->net_addr), - stat->net_rtp_port); - cmd->reply = talloc_asprintf_append(cmd->reply, - "endpoint_ip_addr=%s,endpoint_port=%d,", - inet_ntoa(stat->bts_addr), - stat->bts_rtp_port); - cmd->reply = talloc_asprintf_append(cmd->reply, - "nat_pkt_in=%u,nat_pkt_out=%u," - "nat_bytes_in=%u,nat_bytes_out=%u," - "nat_jitter=%u,nat_pkt_lost=%d,", - stat->bts_pr, stat->net_ps, - stat->bts_or, stat->net_os, - stat->bts_jitter, stat->bts_loss); - cmd->reply = talloc_asprintf_append(cmd->reply, - "bsc_pkt_in=%u,bsc_pkt_out=%u," - "bsc_bytes_in=%u,bsc_bytes_out=%u," - "bsc_jitter=%u,bsc_pkt_lost=%d,", - n_pr, b_ps, - n_or, b_os, - jitter, loss); - cmd->reply = talloc_asprintf_append(cmd->reply, - "sccp_src_ref=%u,sccp_dst_ref=%u", - sccp_src_ref_to_int(&stat->src_ref), - sccp_src_ref_to_int(&stat->remote_ref)); - - /* send it and be done */ - ctrl_cmd_send_to_all(bsc->nat->ctrl, cmd); - talloc_free(cmd); - -free_stat: - bsc->pending_dlcx_count -= 1; - llist_del(&stat->entry); - talloc_free(stat); -} - - -struct nat_sccp_connection *bsc_mgcp_find_con(struct bsc_nat *nat, int endpoint) -{ - struct nat_sccp_connection *con = NULL; - struct nat_sccp_connection *sccp; - - llist_for_each_entry(sccp, &nat->sccp_connections, list_entry) { - if (sccp->msc_endp == -1) - continue; - if (sccp->msc_endp != endpoint) - continue; - - con = sccp; - } - - if (con) - return con; - - LOGP(DMGCP, LOGL_ERROR, - "Failed to find the connection for endpoint: 0x%x\n", endpoint); - return NULL; -} - -static int nat_osmux_only(struct mgcp_config *mgcp_cfg, struct bsc_config *bsc_cfg) -{ - if (mgcp_cfg->osmux == OSMUX_USAGE_ONLY) - return 1; - if (bsc_cfg->osmux == OSMUX_USAGE_ONLY) - return 1; - return 0; -} - -static int bsc_mgcp_policy_cb(struct mgcp_trunk_config *tcfg, int endpoint, int state, const char *transaction_id) -{ - struct bsc_nat *nat; - struct bsc_endpoint *bsc_endp; - struct nat_sccp_connection *sccp; - struct mgcp_endpoint *mgcp_endp; - struct msgb *bsc_msg; - - nat = tcfg->cfg->data; - bsc_endp = &nat->bsc_endpoints[endpoint]; - mgcp_endp = &nat->mgcp_cfg->trunk.endpoints[endpoint]; - - if (bsc_endp->transaction_id) { - LOGP(DMGCP, LOGL_ERROR, "Endpoint 0x%x had pending transaction: '%s'\n", - endpoint, bsc_endp->transaction_id); - talloc_free(bsc_endp->transaction_id); - bsc_endp->transaction_id = NULL; - bsc_endp->transaction_state = 0; - } - bsc_endp->bsc = NULL; - - sccp = bsc_mgcp_find_con(nat, endpoint); - - if (!sccp) { - LOGP(DMGCP, LOGL_ERROR, "Did not find BSC for change on endpoint: 0x%x state: %d\n", endpoint, state); - - switch (state) { - case MGCP_ENDP_CRCX: - return MGCP_POLICY_REJECT; - break; - case MGCP_ENDP_DLCX: - return MGCP_POLICY_CONT; - break; - case MGCP_ENDP_MDCX: - return MGCP_POLICY_CONT; - break; - default: - LOGP(DMGCP, LOGL_FATAL, "Unhandled state: %d\n", state); - return MGCP_POLICY_CONT; - break; - } - } - - /* Allocate a Osmux circuit ID */ - if (state == MGCP_ENDP_CRCX) { - if (nat->mgcp_cfg->osmux && sccp->bsc->cfg->osmux) { - osmux_allocate_cid(mgcp_endp); - if (mgcp_endp->osmux.allocated_cid < 0 && - nat_osmux_only(nat->mgcp_cfg, sccp->bsc->cfg)) { - LOGP(DMGCP, LOGL_ERROR, - "Rejecting usage of endpoint\n"); - return MGCP_POLICY_REJECT; - } - } - } - - /* we need to generate a new and patched message */ - bsc_msg = bsc_mgcp_rewrite((char *) nat->mgcp_msg, nat->mgcp_length, - sccp->bsc_endp, mgcp_bts_src_addr(mgcp_endp), - mgcp_endp->bts_end.local_port, - mgcp_endp->osmux.allocated_cid, - &mgcp_endp->net_end.codec.payload_type, - nat->sdp_ensure_amr_mode_set); - if (!bsc_msg) { - LOGP(DMGCP, LOGL_ERROR, "Failed to patch the msg.\n"); - return MGCP_POLICY_CONT; - } - - - bsc_endp->transaction_id = talloc_strdup(nat, transaction_id); - bsc_endp->transaction_state = state; - bsc_endp->bsc = sccp->bsc; - - /* we need to update some bits */ - if (state == MGCP_ENDP_CRCX) { - struct sockaddr_in sock; - - /* Annotate the allocated Osmux CID until the bsc confirms that - * it agrees to use Osmux for this voice flow. - */ - if (mgcp_endp->osmux.allocated_cid >= 0 && - mgcp_endp->osmux.state != OSMUX_STATE_ENABLED) { - mgcp_endp->osmux.state = OSMUX_STATE_NEGOTIATING; - mgcp_endp->osmux.cid = mgcp_endp->osmux.allocated_cid; - } - - socklen_t len = sizeof(sock); - if (getpeername(sccp->bsc->write_queue.bfd.fd, (struct sockaddr *) &sock, &len) != 0) { - LOGP(DMGCP, LOGL_ERROR, "Can not get the peername...%d/%s\n", - errno, strerror(errno)); - } else { - mgcp_endp->bts_end.addr = sock.sin_addr; - } - - /* send the message and a fake MDCX to force sending of a dummy packet */ - bsc_write(sccp->bsc, bsc_msg, IPAC_PROTO_MGCP_OLD); - bsc_mgcp_send_mdcx(sccp->bsc, sccp->bsc_endp, mgcp_endp); - return MGCP_POLICY_DEFER; - } else if (state == MGCP_ENDP_DLCX) { - /* we will free the endpoint now and send a DLCX to the BSC */ - msgb_free(bsc_msg); - bsc_mgcp_dlcx(sccp); - - /* libmgcp clears the MGCP endpoint for us */ - if (mgcp_endp->osmux.state == OSMUX_STATE_ENABLED) - osmux_release_cid(mgcp_endp); - - return MGCP_POLICY_CONT; - } else { - bsc_write(sccp->bsc, bsc_msg, IPAC_PROTO_MGCP_OLD); - return MGCP_POLICY_DEFER; - } -} - -/* - * We do have a failure, free data downstream.. - */ -static void free_chan_downstream(struct mgcp_endpoint *endp, struct bsc_endpoint *bsc_endp, - struct bsc_connection *bsc) -{ - LOGP(DMGCP, LOGL_ERROR, "No CI, freeing endpoint 0x%x in state %d\n", - ENDPOINT_NUMBER(endp), bsc_endp->transaction_state); - - /* if a CRCX failed... send a DLCX down the stream */ - if (bsc_endp->transaction_state == MGCP_ENDP_CRCX) { - struct nat_sccp_connection *con; - con = bsc_mgcp_find_con(bsc->nat, ENDPOINT_NUMBER(endp)); - if (!con) { - LOGP(DMGCP, LOGL_ERROR, - "No SCCP connection for endp 0x%x\n", - ENDPOINT_NUMBER(endp)); - } else { - if (con->bsc == bsc) { - bsc_mgcp_send_dlcx(bsc, con->bsc_endp, con->bsc->next_transaction++); - } else { - LOGP(DMGCP, LOGL_ERROR, - "Endpoint belongs to a different BSC\n"); - } - } - } - - bsc_mgcp_free_endpoint(bsc->nat, ENDPOINT_NUMBER(endp)); - mgcp_release_endp(endp); -} - -static void bsc_mgcp_osmux_confirm(struct mgcp_endpoint *endp, const char *str) -{ - unsigned int osmux_cid; - char *res; - - res = strstr(str, "X-Osmux: "); - if (!res) { - LOGP(DMGCP, LOGL_INFO, - "BSC doesn't want to use Osmux, failing back to RTP\n"); - goto err; - } - - if (sscanf(res, "X-Osmux: %u", &osmux_cid) != 1) { - LOGP(DMGCP, LOGL_ERROR, "Failed to parse Osmux CID '%s'\n", - str); - goto err; - } - - if (endp->osmux.cid != osmux_cid) { - LOGP(DMGCP, LOGL_ERROR, - "BSC sent us wrong CID %u, we expected %u", - osmux_cid, endp->osmux.cid); - goto err; - } - - LOGP(DMGCP, LOGL_NOTICE, "bsc accepted to use Osmux (cid=%u)\n", - osmux_cid); - endp->osmux.state = OSMUX_STATE_ACTIVATING; - return; -err: - osmux_release_cid(endp); - endp->osmux.state = OSMUX_STATE_DISABLED; -} - -/* - * We have received a msg from the BSC. We will see if we know - * this transaction and if it belongs to the BSC. Then we will - * need to patch the content to point to the local network and we - * need to update the I: that was assigned by the BSS. - * - * Only responses to CRCX and DLCX should arrive here. The DLCX - * needs to be handled specially to combine the two statistics. - */ -void bsc_mgcp_forward(struct bsc_connection *bsc, struct msgb *msg) -{ - struct msgb *output; - struct bsc_endpoint *bsc_endp = NULL; - struct mgcp_endpoint *endp = NULL; - int i, code; - char transaction_id[60]; - - /* Some assumption that our buffer is big enough.. and null terminate */ - if (msgb_l2len(msg) > 2000) { - LOGP(DMGCP, LOGL_ERROR, "MGCP message too long.\n"); - return; - } - - msg->l2h[msgb_l2len(msg)] = '\0'; - - if (bsc_mgcp_parse_response((const char *) msg->l2h, &code, transaction_id) != 0) { - LOGP(DMGCP, LOGL_ERROR, "Failed to parse response code.\n"); - return; - } - - for (i = 1; i < bsc->nat->mgcp_cfg->trunk.number_endpoints; ++i) { - if (bsc->nat->bsc_endpoints[i].bsc != bsc) - continue; - /* no one listening? a bug? */ - if (!bsc->nat->bsc_endpoints[i].transaction_id) - continue; - if (strcmp(transaction_id, bsc->nat->bsc_endpoints[i].transaction_id) != 0) - continue; - - endp = &bsc->nat->mgcp_cfg->trunk.endpoints[i]; - bsc_endp = &bsc->nat->bsc_endpoints[i]; - break; - } - - if (!bsc_endp && strncmp("nat-", transaction_id, 4) == 0) { - handle_dlcx_response(bsc, msg, code, transaction_id); - return; - } - - if (!bsc_endp) { - LOGP(DMGCP, LOGL_ERROR, "Could not find active endpoint: %s for msg: '%s'\n", - transaction_id, (const char *) msg->l2h); - return; - } - - endp->ci = bsc_mgcp_extract_ci((const char *) msg->l2h); - if (endp->ci == CI_UNUSED) { - free_chan_downstream(endp, bsc_endp, bsc); - return; - } - - if (endp->osmux.state == OSMUX_STATE_NEGOTIATING) - bsc_mgcp_osmux_confirm(endp, (const char *) msg->l2h); - - /* If we require osmux and it is disabled.. fail */ - if (nat_osmux_only(bsc->nat->mgcp_cfg, bsc->cfg) && - endp->osmux.state == OSMUX_STATE_DISABLED) { - LOGP(DMGCP, LOGL_ERROR, - "Failed to activate osmux endpoint 0x%x\n", - ENDPOINT_NUMBER(endp)); - free_chan_downstream(endp, bsc_endp, bsc); - return; - } - - /* free some stuff */ - talloc_free(bsc_endp->transaction_id); - bsc_endp->transaction_id = NULL; - bsc_endp->transaction_state = 0; - - /* - * rewrite the information. In case the endpoint was deleted - * there should be nothing for us to rewrite so putting endp->rtp_port - * with the value of 0 should be no problem. - */ - output = bsc_mgcp_rewrite((char * ) msg->l2h, msgb_l2len(msg), -1, - mgcp_net_src_addr(endp), - endp->net_end.local_port, -1, - &endp->bts_end.codec.payload_type, - bsc->nat->sdp_ensure_amr_mode_set); - if (!output) { - LOGP(DMGCP, LOGL_ERROR, "Failed to rewrite MGCP msg.\n"); - return; - } - - mgcp_queue_for_call_agent(bsc->nat, output); -} - -int bsc_mgcp_parse_response(const char *str, int *code, char transaction[60]) -{ - int rc; - /* we want to parse two strings */ - rc = sscanf(str, "%3d %59s\n", code, transaction) != 2; - transaction[59] = '\0'; - return rc; -} - -uint32_t bsc_mgcp_extract_ci(const char *str) -{ - unsigned int ci; - char *res = strstr(str, "I: "); - if (!res) { - LOGP(DMGCP, LOGL_ERROR, "No CI in msg '%s'\n", str); - return CI_UNUSED; - } - - if (sscanf(res, "I: %u", &ci) != 1) { - LOGP(DMGCP, LOGL_ERROR, "Failed to parse CI in msg '%s'\n", str); - return CI_UNUSED; - } - - return ci; -} - -/** - * Create a new MGCPCommand based on the input and endpoint from a message - */ -static void patch_mgcp(struct msgb *output, const char *op, const char *tok, - int endp, int len, int cr, int osmux_cid) -{ - int slen; - int ret; - char buf[40]; - char osmux_extension[strlen("\nX-Osmux: 255") + 1]; - - buf[0] = buf[39] = '\0'; - ret = sscanf(tok, "%*s %s", buf); - if (ret != 1) { - LOGP(DMGCP, LOGL_ERROR, - "Failed to find Endpoint in: %s\n", tok); - return; - } - - if (osmux_cid >= 0) - sprintf(osmux_extension, "\nX-Osmux: %u", osmux_cid & 0xff); - else - osmux_extension[0] = '\0'; - - slen = sprintf((char *) output->l3h, "%s %s %x@mgw MGCP 1.0%s%s", - op, buf, endp, osmux_extension, cr ? "\r\n" : "\n"); - output->l3h = msgb_put(output, slen); -} - -/* we need to replace some strings... */ -struct msgb *bsc_mgcp_rewrite(char *input, int length, int endpoint, - const char *ip, int port, int osmux_cid, - int *first_payload_type, int ensure_mode_set) -{ - static const char crcx_str[] = "CRCX "; - static const char dlcx_str[] = "DLCX "; - static const char mdcx_str[] = "MDCX "; - - static const char ip_str[] = "c=IN IP4 "; - static const char aud_str[] = "m=audio "; - static const char fmt_str[] = "a=fmtp:"; - - char buf[128]; - char *running, *token; - struct msgb *output; - - /* keep state to add the a=fmtp line */ - int found_fmtp = 0; - int payload = -1; - int cr = 1; - - if (length > 4096 - 256) { - LOGP(DMGCP, LOGL_ERROR, "Input is too long.\n"); - return NULL; - } - - output = msgb_alloc_headroom(4096, 128, "MGCP rewritten"); - if (!output) { - LOGP(DMGCP, LOGL_ERROR, "Failed to allocate new MGCP msg.\n"); - return NULL; - } - - running = input; - output->l2h = output->data; - output->l3h = output->l2h; - for (token = strsep(&running, "\n"); running; token = strsep(&running, "\n")) { - int len = strlen(token); - cr = len > 0 && token[len - 1] == '\r'; - - if (strncmp(crcx_str, token, (sizeof crcx_str) - 1) == 0) { - patch_mgcp(output, "CRCX", token, endpoint, len, cr, osmux_cid); - } else if (strncmp(dlcx_str, token, (sizeof dlcx_str) - 1) == 0) { - patch_mgcp(output, "DLCX", token, endpoint, len, cr, -1); - } else if (strncmp(mdcx_str, token, (sizeof mdcx_str) - 1) == 0) { - patch_mgcp(output, "MDCX", token, endpoint, len, cr, -1); - } else if (strncmp(ip_str, token, (sizeof ip_str) - 1) == 0) { - output->l3h = msgb_put(output, strlen(ip_str)); - memcpy(output->l3h, ip_str, strlen(ip_str)); - output->l3h = msgb_put(output, strlen(ip)); - memcpy(output->l3h, ip, strlen(ip)); - - if (cr) { - output->l3h = msgb_put(output, 2); - output->l3h[0] = '\r'; - output->l3h[1] = '\n'; - } else { - output->l3h = msgb_put(output, 1); - output->l3h[0] = '\n'; - } - } else if (strncmp(aud_str, token, (sizeof aud_str) - 1) == 0) { - int offset; - if (sscanf(token, "m=audio %*d RTP/AVP %n%d", &offset, &payload) != 1) { - LOGP(DMGCP, LOGL_ERROR, "Could not parsed audio line.\n"); - msgb_free(output); - return NULL; - } - - snprintf(buf, sizeof(buf)-1, "m=audio %d RTP/AVP %s\n", - port, &token[offset]); - buf[sizeof(buf)-1] = '\0'; - - output->l3h = msgb_put(output, strlen(buf)); - memcpy(output->l3h, buf, strlen(buf)); - } else if (strncmp(fmt_str, token, (sizeof fmt_str) - 1) == 0) { - found_fmtp = 1; - goto copy; - } else { -copy: - output->l3h = msgb_put(output, len + 1); - memcpy(output->l3h, token, len); - output->l3h[len] = '\n'; - } - } - - /* - * the above code made sure that we have 128 bytes lefts. So we can - * safely append another line. - */ - if (ensure_mode_set && !found_fmtp && payload != -1) { - snprintf(buf, sizeof(buf) - 1, "a=fmtp:%d mode-set=2%s", - payload, cr ? "\r\n" : "\n"); - buf[sizeof(buf) - 1] = '\0'; - output->l3h = msgb_put(output, strlen(buf)); - memcpy(output->l3h, buf, strlen(buf)); - } - - if (payload != -1 && first_payload_type) - *first_payload_type = payload; - - return output; -} - -/* - * This comes from the MSC and we will now parse it. The caller needs - * to free the msgb. - */ -void bsc_nat_handle_mgcp(struct bsc_nat *nat, struct msgb *msg) -{ - struct msgb *resp; - - if (!nat->mgcp_ipa) { - LOGP(DMGCP, LOGL_ERROR, "MGCP message not allowed on IPA.\n"); - return; - } - - if (msgb_l2len(msg) > sizeof(nat->mgcp_msg) - 1) { - LOGP(DMGCP, LOGL_ERROR, "MGCP msg too big for handling.\n"); - return; - } - - memcpy(nat->mgcp_msg, msg->l2h, msgb_l2len(msg)); - nat->mgcp_length = msgb_l2len(msg); - nat->mgcp_msg[nat->mgcp_length] = '\0'; - - /* now handle the message */ - resp = mgcp_handle_message(nat->mgcp_cfg, msg); - - /* we do have a direct answer... e.g. AUEP */ - if (resp) - mgcp_queue_for_call_agent(nat, resp); - - return; -} - -static int mgcp_do_read(struct osmo_fd *fd) -{ - struct bsc_nat *nat; - struct msgb *msg, *resp; - int rc; - - nat = fd->data; - - rc = read(fd->fd, nat->mgcp_msg, sizeof(nat->mgcp_msg) - 1); - if (rc <= 0) { - LOGP(DMGCP, LOGL_ERROR, "Failed to read errno: %d\n", errno); - return -1; - } - - nat->mgcp_msg[rc] = '\0'; - nat->mgcp_length = rc; - - msg = msgb_alloc(sizeof(nat->mgcp_msg), "MGCP GW Read"); - if (!msg) { - LOGP(DMGCP, LOGL_ERROR, "Failed to create buffer.\n"); - return -1; - } - - msg->l2h = msgb_put(msg, rc); - memcpy(msg->l2h, nat->mgcp_msg, msgb_l2len(msg)); - resp = mgcp_handle_message(nat->mgcp_cfg, msg); - msgb_free(msg); - - /* we do have a direct answer... e.g. AUEP */ - if (resp) - mgcp_queue_for_call_agent(nat, resp); - - return 0; -} - -static int mgcp_do_write(struct osmo_fd *bfd, struct msgb *msg) -{ - int rc; - - rc = write(bfd->fd, msg->data, msg->len); - - if (rc != msg->len) { - LOGP(DMGCP, LOGL_ERROR, "Failed to write msg to MGCP CallAgent.\n"); - return -1; - } - - return rc; -} - -static int init_mgcp_socket(struct bsc_nat *nat, struct mgcp_config *cfg) -{ - struct sockaddr_in addr; - int on; - - cfg->gw_fd.bfd.fd = socket(AF_INET, SOCK_DGRAM, 0); - if (cfg->gw_fd.bfd.fd < 0) { - LOGP(DMGCP, LOGL_ERROR, "Failed to create MGCP socket. errno: %d\n", errno); - return -1; - } - - on = 1; - setsockopt(cfg->gw_fd.bfd.fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)); - - memset(&addr, 0, sizeof(addr)); - addr.sin_family = AF_INET; - addr.sin_port = htons(cfg->source_port); - inet_aton(cfg->source_addr, &addr.sin_addr); - - if (bind(cfg->gw_fd.bfd.fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) { - LOGP(DMGCP, LOGL_ERROR, "Failed to bind on %s:%d errno: %d\n", - cfg->source_addr, cfg->source_port, errno); - close(cfg->gw_fd.bfd.fd); - cfg->gw_fd.bfd.fd = -1; - return -1; - } - - addr.sin_port = htons(2727); - inet_aton(cfg->call_agent_addr, &addr.sin_addr); - if (connect(cfg->gw_fd.bfd.fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) { - LOGP(DMGCP, LOGL_ERROR, "Failed to connect to: '%s'. errno: %d\n", - cfg->call_agent_addr, errno); - close(cfg->gw_fd.bfd.fd); - cfg->gw_fd.bfd.fd = -1; - return -1; - } - - osmo_wqueue_init(&cfg->gw_fd, 10); - cfg->gw_fd.bfd.when = BSC_FD_READ; - cfg->gw_fd.bfd.data = nat; - cfg->gw_fd.read_cb = mgcp_do_read; - cfg->gw_fd.write_cb = mgcp_do_write; - - if (osmo_fd_register(&cfg->gw_fd.bfd) != 0) { - LOGP(DMGCP, LOGL_ERROR, "Failed to register MGCP fd.\n"); - close(cfg->gw_fd.bfd.fd); - cfg->gw_fd.bfd.fd = -1; - return -1; - } - - return 0; -} - -int bsc_mgcp_nat_init(struct bsc_nat *nat) -{ - struct mgcp_config *cfg = nat->mgcp_cfg; - - if (!cfg->call_agent_addr) { - LOGP(DMGCP, LOGL_ERROR, "The BSC nat requires the call agent ip to be set.\n"); - return -1; - } - - if (cfg->bts_ip) { - LOGP(DMGCP, LOGL_ERROR, "Do not set the BTS ip for the nat.\n"); - return -1; - } - - /* initialize the MGCP socket */ - if (!nat->mgcp_ipa) { - int rc = init_mgcp_socket(nat, cfg); - if (rc != 0) - return rc; - } - - - /* some more MGCP config handling */ - cfg->data = nat; - cfg->policy_cb = bsc_mgcp_policy_cb; - - if (cfg->bts_ip) - talloc_free(cfg->bts_ip); - cfg->bts_ip = ""; - - nat->bsc_endpoints = talloc_zero_array(nat, - struct bsc_endpoint, - cfg->trunk.number_endpoints + 1); - if (!nat->bsc_endpoints) { - LOGP(DMGCP, LOGL_ERROR, "Failed to allocate nat endpoints\n"); - close(cfg->gw_fd.bfd.fd); - cfg->gw_fd.bfd.fd = -1; - return -1; - } - - if (mgcp_reset_transcoder(cfg) < 0) { - LOGP(DMGCP, LOGL_ERROR, "Failed to send packet to the transcoder.\n"); - talloc_free(nat->bsc_endpoints); - nat->bsc_endpoints = NULL; - close(cfg->gw_fd.bfd.fd); - cfg->gw_fd.bfd.fd = -1; - return -1; - } - - return 0; -} - -void bsc_mgcp_clear_endpoints_for(struct bsc_connection *bsc) -{ - struct rate_ctr *ctr = NULL; - int i; - - if (bsc->cfg) - ctr = &bsc->cfg->stats.ctrg->ctr[BCFG_CTR_DROPPED_CALLS]; - - for (i = 1; i < bsc->nat->mgcp_cfg->trunk.number_endpoints; ++i) { - struct bsc_endpoint *bsc_endp = &bsc->nat->bsc_endpoints[i]; - - if (bsc_endp->bsc != bsc) - continue; - - if (ctr) - rate_ctr_inc(ctr); - - bsc_mgcp_free_endpoint(bsc->nat, i); - mgcp_release_endp(&bsc->nat->mgcp_cfg->trunk.endpoints[i]); - } -} |