| /* |
| * (C) 2012-2013 by Pablo Neira Ayuso <pablo@gnumonks.org> |
| * (C) 2012-2013 by On Waves ehf <http://www.on-waves.com> |
| * All rights not specifically granted under this license are 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. |
| */ |
| |
| #include <stdio.h> /* for printf */ |
| #include <string.h> /* for memcpy */ |
| #include <stdlib.h> /* for abs */ |
| #include <inttypes.h> /* for PRIu64 */ |
| #include <netinet/in.h> |
| #include <osmocom/core/msgb.h> |
| #include <osmocom/core/talloc.h> |
| |
| #include <osmocom/netif/osmux.h> |
| #include <osmocom/netif/rtp.h> |
| |
| #include <osmocom/mgcp/mgcp.h> |
| #include <osmocom/mgcp/mgcp_internal.h> |
| #include <osmocom/mgcp/osmux.h> |
| #include <osmocom/mgcp/mgcp_conn.h> |
| #include <osmocom/mgcp/mgcp_endp.h> |
| |
| static struct osmo_fd osmux_fd; |
| |
| static LLIST_HEAD(osmux_handle_list); |
| |
| struct osmux_handle { |
| struct llist_head head; |
| struct osmux_in_handle *in; |
| struct in_addr rem_addr; |
| int rem_port; |
| int refcnt; |
| }; |
| |
| static void *osmux; |
| |
| /* Deliver OSMUX batch to the remote end */ |
| static void osmux_deliver_cb(struct msgb *batch_msg, void *data) |
| { |
| struct osmux_handle *handle = data; |
| struct sockaddr_in out = { |
| .sin_family = AF_INET, |
| .sin_port = handle->rem_port, |
| }; |
| |
| memcpy(&out.sin_addr, &handle->rem_addr, sizeof(handle->rem_addr)); |
| sendto(osmux_fd.fd, batch_msg->data, batch_msg->len, 0, |
| (struct sockaddr *)&out, sizeof(out)); |
| msgb_free(batch_msg); |
| } |
| |
| /* Lookup existing OSMUX handle for specified destination address. */ |
| static struct osmux_handle * |
| osmux_handle_find_get(struct in_addr *addr, int rem_port) |
| { |
| struct osmux_handle *h; |
| |
| llist_for_each_entry(h, &osmux_handle_list, head) { |
| if (memcmp(&h->rem_addr, addr, sizeof(struct in_addr)) == 0 && |
| h->rem_port == rem_port) { |
| LOGP(DLMGCP, LOGL_DEBUG, "using existing OSMUX handle " |
| "for addr=%s:%d\n", |
| inet_ntoa(*addr), ntohs(rem_port)); |
| h->refcnt++; |
| return h; |
| } |
| } |
| |
| return NULL; |
| } |
| |
| /* Put down no longer needed OSMUX handle */ |
| static void osmux_handle_put(struct osmux_in_handle *in) |
| { |
| struct osmux_handle *h; |
| |
| llist_for_each_entry(h, &osmux_handle_list, head) { |
| if (h->in == in) { |
| if (--h->refcnt == 0) { |
| LOGP(DLMGCP, LOGL_INFO, |
| "Releasing unused osmux handle for %s:%d\n", |
| inet_ntoa(h->rem_addr), |
| ntohs(h->rem_port)); |
| LOGP(DLMGCP, LOGL_INFO, "Stats: " |
| "input RTP msgs: %u bytes: %"PRIu64" " |
| "output osmux msgs: %u bytes: %"PRIu64"\n", |
| in->stats.input_rtp_msgs, |
| in->stats.input_rtp_bytes, |
| in->stats.output_osmux_msgs, |
| in->stats.output_osmux_bytes); |
| llist_del(&h->head); |
| osmux_xfrm_input_fini(h->in); |
| talloc_free(h); |
| } |
| return; |
| } |
| } |
| LOGP(DLMGCP, LOGL_ERROR, "cannot find Osmux input handle %p\n", in); |
| } |
| |
| /* Allocate free OSMUX handle */ |
| static struct osmux_handle * |
| osmux_handle_alloc(struct mgcp_config *cfg, struct in_addr *addr, int rem_port) |
| { |
| struct osmux_handle *h; |
| |
| h = talloc_zero(osmux, struct osmux_handle); |
| if (!h) |
| return NULL; |
| h->rem_addr = *addr; |
| h->rem_port = rem_port; |
| h->refcnt++; |
| |
| h->in = talloc_zero(h, struct osmux_in_handle); |
| if (!h->in) { |
| talloc_free(h); |
| return NULL; |
| } |
| |
| /* sequence number to start OSMUX message from */ |
| h->in->osmux_seq = 0; |
| |
| h->in->batch_factor = cfg->osmux_batch; |
| |
| /* If batch size is zero, the library defaults to 1470 bytes. */ |
| h->in->batch_size = cfg->osmux_batch_size; |
| h->in->deliver = osmux_deliver_cb; |
| osmux_xfrm_input_init(h->in); |
| h->in->data = h; |
| |
| llist_add(&h->head, &osmux_handle_list); |
| |
| LOGP(DLMGCP, LOGL_DEBUG, "created new OSMUX handle for addr=%s:%d\n", |
| inet_ntoa(*addr), ntohs(rem_port)); |
| |
| return h; |
| } |
| |
| /* Lookup existing handle for a specified address, if the handle can not be |
| * found, the function will automatically allocate one */ |
| static struct osmux_in_handle * |
| osmux_handle_lookup(struct mgcp_config *cfg, struct in_addr *addr, int rem_port) |
| { |
| struct osmux_handle *h; |
| |
| h = osmux_handle_find_get(addr, rem_port); |
| if (h != NULL) |
| return h->in; |
| |
| h = osmux_handle_alloc(cfg, addr, rem_port); |
| if (h == NULL) |
| return NULL; |
| |
| return h->in; |
| } |
| |
| /*! send RTP packet through OSMUX connection. |
| * \param[in] buf rtp data |
| * \param[in] buf_len length of rtp data |
| * \param[in] conn associated RTP connection |
| * \returns 0 on success, -1 on ERROR */ |
| int osmux_xfrm_to_osmux(char *buf, int buf_len, struct mgcp_conn_rtp *conn) |
| { |
| int ret; |
| struct msgb *msg; |
| |
| msg = msgb_alloc(4096, "RTP"); |
| if (!msg) |
| return -1; |
| |
| memcpy(msg->data, buf, buf_len); |
| msgb_put(msg, buf_len); |
| |
| while ((ret = osmux_xfrm_input(conn->osmux.in, msg, conn->osmux.cid)) > 0) { |
| /* batch full, build and deliver it */ |
| osmux_xfrm_input_deliver(conn->osmux.in); |
| } |
| return 0; |
| } |
| |
| /* Lookup the endpoint that corresponds to the specified address (port) */ |
| static struct mgcp_endpoint * |
| endpoint_lookup(struct mgcp_config *cfg, int cid, |
| struct in_addr *from_addr, int type) |
| { |
| struct mgcp_endpoint *endp = NULL; |
| int i; |
| struct mgcp_conn_rtp *conn_net = NULL; |
| struct mgcp_conn_rtp *conn_bts = NULL; |
| |
| for (i=0; i<cfg->trunk.number_endpoints; i++) { |
| struct in_addr *this; |
| |
| endp = &cfg->trunk.endpoints[i]; |
| |
| #if 0 |
| if (!tmp->allocated) |
| continue; |
| #endif |
| |
| switch(type) { |
| case MGCP_DEST_NET: |
| /* FIXME: Get rid of CONN_ID_XXX! */ |
| conn_net = mgcp_conn_get_rtp(endp, CONN_ID_NET); |
| if (conn_net) |
| this = &conn_net->end.addr; |
| else |
| this = NULL; |
| break; |
| case MGCP_DEST_BTS: |
| /* FIXME: Get rid of CONN_ID_XXX! */ |
| conn_bts = mgcp_conn_get_rtp(endp, CONN_ID_BTS); |
| if (conn_bts) |
| this = &conn_bts->end.addr; |
| else |
| this = NULL; |
| break; |
| default: |
| /* Should not ever happen */ |
| LOGP(DLMGCP, LOGL_ERROR, "Bad type %d. Fix your code.\n", type); |
| return NULL; |
| } |
| |
| /* FIXME: Get rid of CONN_ID_XXX! */ |
| conn_net = mgcp_conn_get_rtp(endp, CONN_ID_NET); |
| if (conn_net && this && conn_net->osmux.cid == cid |
| && this->s_addr == from_addr->s_addr) |
| return endp; |
| } |
| |
| LOGP(DLMGCP, LOGL_ERROR, "Cannot find endpoint with cid=%d\n", cid); |
| |
| return NULL; |
| } |
| |
| static void scheduled_tx_net_cb(struct msgb *msg, void *data) |
| { |
| struct mgcp_endpoint *endp = data; |
| struct mgcp_conn_rtp *conn_net = NULL; |
| struct mgcp_conn_rtp *conn_bts = NULL; |
| |
| /* FIXME: Get rid of CONN_ID_XXX! */ |
| conn_bts = mgcp_conn_get_rtp(endp, CONN_ID_BTS); |
| conn_net = mgcp_conn_get_rtp(endp, CONN_ID_NET); |
| if (!conn_bts || !conn_net) |
| return; |
| |
| struct sockaddr_in addr = { |
| .sin_addr = conn_net->end.addr, |
| .sin_port = conn_net->end.rtp_port, |
| }; |
| |
| rate_ctr_inc(&conn_bts->rate_ctr_group->ctr[RTP_PACKETS_TX_CTR]); |
| rate_ctr_add(&conn_bts->rate_ctr_group->ctr[RTP_OCTETS_TX_CTR], msg->len); |
| |
| /* Send RTP data to NET */ |
| /* FIXME: Get rid of conn_bts and conn_net! */ |
| mgcp_send(endp, 1, &addr, (char *)msg->data, msg->len, |
| conn_bts, conn_net); |
| msgb_free(msg); |
| } |
| |
| static void scheduled_tx_bts_cb(struct msgb *msg, void *data) |
| { |
| struct mgcp_endpoint *endp = data; |
| struct mgcp_conn_rtp *conn_net = NULL; |
| struct mgcp_conn_rtp *conn_bts = NULL; |
| |
| /* FIXME: Get rid of CONN_ID_XXX! */ |
| conn_bts = mgcp_conn_get_rtp(endp, CONN_ID_BTS); |
| conn_net = mgcp_conn_get_rtp(endp, CONN_ID_NET); |
| if (!conn_bts || !conn_net) |
| return; |
| |
| struct sockaddr_in addr = { |
| .sin_addr = conn_bts->end.addr, |
| .sin_port = conn_bts->end.rtp_port, |
| }; |
| |
| rate_ctr_inc(&conn_net->rate_ctr_group->ctr[RTP_PACKETS_TX_CTR]); |
| rate_ctr_add(&conn_net->rate_ctr_group->ctr[RTP_OCTETS_TX_CTR], msg->len); |
| |
| /* Send RTP data to BTS */ |
| /* FIXME: Get rid of conn_bts and conn_net! */ |
| mgcp_send(endp, 1, &addr, (char *)msg->data, msg->len, |
| conn_net, conn_bts); |
| msgb_free(msg); |
| } |
| |
| static struct msgb *osmux_recv(struct osmo_fd *ofd, struct sockaddr_in *addr) |
| { |
| struct msgb *msg; |
| socklen_t slen = sizeof(*addr); |
| int ret; |
| |
| msg = msgb_alloc(4096, "OSMUX"); |
| if (!msg) { |
| LOGP(DLMGCP, LOGL_ERROR, "cannot allocate message\n"); |
| return NULL; |
| } |
| ret = recvfrom(ofd->fd, msg->data, msg->data_len, 0, |
| (struct sockaddr *)addr, &slen); |
| if (ret <= 0) { |
| msgb_free(msg); |
| LOGP(DLMGCP, LOGL_ERROR, "cannot receive message\n"); |
| return NULL; |
| } |
| msgb_put(msg, ret); |
| |
| return msg; |
| } |
| |
| /* Updates endp osmux state and returns 0 if it can process messages, -1 otherwise */ |
| static int endp_osmux_state_check(struct mgcp_endpoint *endp, struct mgcp_conn_rtp *conn, |
| bool sending) |
| { |
| switch(conn->osmux.state) { |
| case OSMUX_STATE_ACTIVATING: |
| if (osmux_enable_conn(endp, conn, &conn->end.addr, htons(endp->cfg->osmux_port)) < 0) { |
| LOGP(DLMGCP, LOGL_ERROR, |
| "Could not enable osmux for conn:%s\n", |
| mgcp_conn_dump(conn->conn)); |
| return -1; |
| } |
| LOGP(DLMGCP, LOGL_ERROR, |
| "Osmux CID %u for %s:%u is now enabled\n", |
| conn->osmux.cid, inet_ntoa(conn->end.addr), |
| endp->cfg->osmux_port); |
| return 0; |
| case OSMUX_STATE_ENABLED: |
| return 0; |
| default: |
| LOGP(DLMGCP, LOGL_ERROR, |
| "Osmux %s in conn %s without full negotiation, state %d\n", |
| sending ? "sent" : "received", |
| mgcp_conn_dump(conn->conn), conn->osmux.state); |
| return -1; |
| } |
| } |
| |
| static int osmux_legacy_dummy_parse_cid(struct sockaddr_in *addr, struct msgb *msg, |
| uint8_t *osmux_cid) |
| { |
| if (msg->len < 1 + sizeof(osmux_cid)) { |
| LOGP(DLMGCP, LOGL_ERROR, |
| "Discarding truncated Osmux dummy load\n"); |
| return -1; |
| } |
| |
| /* extract the osmux CID from the dummy message */ |
| memcpy(osmux_cid, &msg->data[1], sizeof(*osmux_cid)); |
| return 0; |
| } |
| |
| #define osmux_chunk_length(msg, rem) (rem - msg->len); |
| |
| int osmux_read_from_bsc_nat_cb(struct osmo_fd *ofd, unsigned int what) |
| { |
| struct msgb *msg; |
| struct osmux_hdr *osmuxh; |
| struct sockaddr_in addr; |
| struct mgcp_config *cfg = ofd->data; |
| uint32_t rem; |
| struct mgcp_conn_rtp *conn_bts = NULL; |
| |
| msg = osmux_recv(ofd, &addr); |
| if (!msg) |
| return -1; |
| |
| if (!cfg->osmux) { |
| LOGP(DLMGCP, LOGL_ERROR, |
| "bsc-nat wants to use Osmux but bsc did not request it\n"); |
| goto out; |
| } |
| |
| /* not any further processing dummy messages */ |
| if (msg->data[0] == MGCP_DUMMY_LOAD) |
| goto out; |
| |
| rem = msg->len; |
| while((osmuxh = osmux_xfrm_output_pull(msg)) != NULL) { |
| struct mgcp_endpoint *endp; |
| |
| /* Yes, we use MGCP_DEST_NET to locate the origin */ |
| endp = endpoint_lookup(cfg, osmuxh->circuit_id, |
| &addr.sin_addr, MGCP_DEST_NET); |
| |
| /* FIXME: Get rid of CONN_ID_XXX! */ |
| conn_bts = mgcp_conn_get_rtp(endp, CONN_ID_BTS); |
| if (!conn_bts) |
| continue; |
| |
| if (!endp) { |
| LOGP(DLMGCP, LOGL_ERROR, |
| "Cannot find an endpoint for circuit_id=%d\n", |
| osmuxh->circuit_id); |
| goto out; |
| } |
| if (endp_osmux_state_check(endp, conn_bts, false) == 0) { |
| conn_bts->osmux.stats.octets += osmux_chunk_length(msg, rem); |
| conn_bts->osmux.stats.chunks++; |
| osmux_xfrm_output_sched(&conn_bts->osmux.out, osmuxh); |
| } |
| rem = msg->len; |
| } |
| out: |
| msgb_free(msg); |
| return 0; |
| } |
| |
| /* This is called from the bsc-nat */ |
| static int osmux_handle_dummy(struct mgcp_config *cfg, struct sockaddr_in *addr, |
| struct msgb *msg, int endp_type) |
| { |
| struct mgcp_endpoint *endp; |
| uint8_t osmux_cid; |
| struct mgcp_conn_rtp *conn = NULL; |
| |
| if (osmux_legacy_dummy_parse_cid(addr, msg, &osmux_cid) < 0) |
| goto out; |
| |
| endp = endpoint_lookup(cfg, osmux_cid, &addr->sin_addr, endp_type); |
| if (!endp) { |
| LOGP(DLMGCP, LOGL_ERROR, |
| "Cannot find endpoint for Osmux CID %d\n", osmux_cid); |
| goto out; |
| } |
| |
| /* FIXME: Get rid of CONN_ID_XXX! */ |
| conn = mgcp_conn_get_rtp(endp, endp_type == MGCP_DEST_BTS ? CONN_ID_NET : CONN_ID_BTS); |
| if (!conn) |
| goto out; |
| |
| endp_osmux_state_check(endp, conn, false); |
| /* Only needed to punch hole in firewall, it can be dropped */ |
| out: |
| msgb_free(msg); |
| return 0; |
| } |
| |
| int osmux_read_from_bsc_cb(struct osmo_fd *ofd, unsigned int what) |
| { |
| struct msgb *msg; |
| struct osmux_hdr *osmuxh; |
| struct sockaddr_in addr; |
| struct mgcp_config *cfg = ofd->data; |
| uint32_t rem; |
| struct mgcp_conn_rtp *conn_net = NULL; |
| |
| msg = osmux_recv(ofd, &addr); |
| if (!msg) |
| return -1; |
| |
| if (!cfg->osmux) { |
| LOGP(DLMGCP, LOGL_ERROR, |
| "bsc wants to use Osmux but bsc-nat did not request it\n"); |
| goto out; |
| } |
| |
| /* not any further processing dummy messages */ |
| if (msg->data[0] == MGCP_DUMMY_LOAD) |
| return osmux_handle_dummy(cfg, &addr, msg, MGCP_DEST_BTS); |
| |
| rem = msg->len; |
| while((osmuxh = osmux_xfrm_output_pull(msg)) != NULL) { |
| struct mgcp_endpoint *endp; |
| |
| /* Yes, we use MGCP_DEST_BTS to locate the origin */ |
| endp = endpoint_lookup(cfg, osmuxh->circuit_id, |
| &addr.sin_addr, MGCP_DEST_BTS); |
| |
| /* FIXME: Get rid of CONN_ID_XXX! */ |
| conn_net = mgcp_conn_get_rtp(endp, CONN_ID_NET); |
| if (!conn_net) |
| continue; |
| |
| if (!endp) { |
| LOGP(DLMGCP, LOGL_ERROR, |
| "Cannot find an endpoint for circuit_id=%d\n", |
| osmuxh->circuit_id); |
| goto out; |
| } |
| if (endp_osmux_state_check(endp, conn_net, false) == 0) { |
| conn_net->osmux.stats.octets += osmux_chunk_length(msg, rem); |
| conn_net->osmux.stats.chunks++; |
| osmux_xfrm_output_sched(&conn_net->osmux.out, osmuxh); |
| } |
| rem = msg->len; |
| } |
| out: |
| msgb_free(msg); |
| return 0; |
| } |
| |
| int osmux_init(int role, struct mgcp_config *cfg) |
| { |
| int ret; |
| |
| switch(role) { |
| case OSMUX_ROLE_BSC: |
| osmux_fd.cb = osmux_read_from_bsc_nat_cb; |
| break; |
| case OSMUX_ROLE_BSC_NAT: |
| osmux_fd.cb = osmux_read_from_bsc_cb; |
| break; |
| default: |
| LOGP(DLMGCP, LOGL_ERROR, "wrong role for OSMUX\n"); |
| return -1; |
| } |
| osmux_fd.data = cfg; |
| |
| ret = mgcp_create_bind(cfg->osmux_addr, &osmux_fd, cfg->osmux_port); |
| if (ret < 0) { |
| LOGP(DLMGCP, LOGL_ERROR, "cannot bind OSMUX socket\n"); |
| return ret; |
| } |
| mgcp_set_ip_tos(osmux_fd.fd, cfg->endp_dscp); |
| osmux_fd.when |= BSC_FD_READ; |
| |
| ret = osmo_fd_register(&osmux_fd); |
| if (ret < 0) { |
| LOGP(DLMGCP, LOGL_ERROR, "cannot register OSMUX socket\n"); |
| return ret; |
| } |
| cfg->osmux_init = 1; |
| |
| return 0; |
| } |
| |
| /*! enable OSXMUX circuit for a specified connection. |
| * \param[in] endp mgcp endpoint (configuration) |
| * \param[in] conn connection to disable |
| * \param[in] addr IP address of remote OSMUX endpoint |
| * \param[in] port portnumber of the remote OSMUX endpoint |
| * \returns 0 on success, -1 on ERROR */ |
| int osmux_enable_conn(struct mgcp_endpoint *endp, struct mgcp_conn_rtp *conn, |
| struct in_addr *addr, uint16_t port) |
| { |
| /*! If osmux is enabled, initialize the output handler. This handler is |
| * used to reconstruct the RTP flow from osmux. The RTP SSRC is |
| * allocated based on the circuit ID (conn_net->osmux.cid), which is unique |
| * in the local scope to the BSC/BSC-NAT. We use it to divide the RTP |
| * SSRC space (2^32) by the OSMUX_CID_MAX + 1 possible circuit IDs, then randomly |
| * select one value from that window. Thus, we have no chance to have |
| * overlapping RTP SSRC traveling to the BTSes behind the BSC, |
| * similarly, for flows traveling to the MSC. |
| */ |
| static const uint32_t rtp_ssrc_winlen = UINT32_MAX / (OSMUX_CID_MAX + 1); |
| uint16_t osmux_dummy = endp->cfg->osmux_dummy; |
| |
| /* Check if osmux is enabled for the specified connection */ |
| if (conn->osmux.state != OSMUX_STATE_ACTIVATING) { |
| LOGP(DLMGCP, LOGL_ERROR, "conn:%s didn't negotiate Osmux, state %d\n", |
| mgcp_conn_dump(conn->conn), conn->osmux.state); |
| return -1; |
| } |
| |
| conn->osmux.in = osmux_handle_lookup(endp->cfg, addr, port); |
| if (!conn->osmux.in) { |
| LOGP(DLMGCP, LOGL_ERROR, "Cannot allocate input osmux handle for conn:%s\n", |
| mgcp_conn_dump(conn->conn)); |
| return -1; |
| } |
| if (!osmux_xfrm_input_open_circuit(conn->osmux.in, conn->osmux.cid, osmux_dummy)) { |
| LOGP(DLMGCP, LOGL_ERROR, "Cannot open osmux circuit %u for conn:%s\n", |
| conn->osmux.cid, mgcp_conn_dump(conn->conn)); |
| return -1; |
| } |
| |
| osmux_xfrm_output_init(&conn->osmux.out, |
| (conn->osmux.cid * rtp_ssrc_winlen) + |
| (random() % rtp_ssrc_winlen)); |
| |
| switch (endp->cfg->role) { |
| case MGCP_BSC_NAT: |
| conn->type = MGCP_OSMUX_BSC_NAT; |
| osmux_xfrm_output_set_tx_cb(&conn->osmux.out, |
| scheduled_tx_net_cb, endp); |
| break; |
| case MGCP_BSC: |
| conn->type = MGCP_OSMUX_BSC; |
| osmux_xfrm_output_set_tx_cb(&conn->osmux.out, |
| scheduled_tx_bts_cb, endp); |
| break; |
| } |
| |
| conn->osmux.state = OSMUX_STATE_ENABLED; |
| |
| return 0; |
| } |
| |
| /*! disable OSXMUX circuit for a specified connection. |
| * \param[in] conn connection to disable */ |
| void osmux_disable_conn(struct mgcp_conn_rtp *conn) |
| { |
| if (!conn) |
| return; |
| |
| if (conn->osmux.state != OSMUX_STATE_ENABLED) |
| return; |
| |
| LOGP(DLMGCP, LOGL_INFO, "Releasing connection %s using Osmux CID %u\n", |
| conn->conn->id, conn->osmux.cid); |
| |
| /* We are closing, we don't need pending RTP packets to be transmitted */ |
| osmux_xfrm_output_set_tx_cb(&conn->osmux.out, NULL, NULL); |
| osmux_xfrm_output_flush(&conn->osmux.out); |
| |
| osmux_xfrm_input_close_circuit(conn->osmux.in, conn->osmux.cid); |
| conn->osmux.state = OSMUX_STATE_DISABLED; |
| conn->osmux.cid = -1; |
| osmux_handle_put(conn->osmux.in); |
| } |
| |
| /*! relase OSXMUX cid, that had been allocated to this connection. |
| * \param[in] conn connection with OSMUX cid to release */ |
| void osmux_release_cid(struct mgcp_conn_rtp *conn) |
| { |
| if (!conn) |
| return; |
| |
| if (conn->osmux.state != OSMUX_STATE_ENABLED) |
| return; |
| |
| if (conn->osmux.allocated_cid >= 0) |
| osmux_put_cid(conn->osmux.allocated_cid); |
| conn->osmux.allocated_cid = -1; |
| } |
| |
| /*! allocate OSXMUX cid to connection. |
| * \param[in] conn connection for which we allocate the OSMUX cid*/ |
| void osmux_allocate_cid(struct mgcp_conn_rtp *conn) |
| { |
| osmux_release_cid(conn); |
| conn->osmux.allocated_cid = osmux_get_cid(); |
| } |
| |
| /*! send RTP dummy packet to OSMUX connection port. |
| * \param[in] endp mcgp endpoint that holds the RTP connection |
| * \param[in] conn associated RTP connection |
| * \returns bytes sent, -1 on error */ |
| int osmux_send_dummy(struct mgcp_endpoint *endp, struct mgcp_conn_rtp *conn) |
| { |
| char buf[1 + sizeof(uint8_t)]; |
| struct in_addr addr_unset = {}; |
| |
| /*! The dummy packet will not be sent via the actual OSMUX connection, |
| * instead it is sent out of band to port where the remote OSMUX |
| * multplexer is listening. The goal is to ensure that the connection |
| * is kept open */ |
| |
| /*! We don't need to send the dummy load for osmux so often as another |
| * endpoint may have already punched the hole in the firewall. This |
| * approach is simple though. */ |
| |
| buf[0] = MGCP_DUMMY_LOAD; |
| memcpy(&buf[1], &conn->osmux.cid, sizeof(conn->osmux.cid)); |
| |
| /* Wait until we have the connection information from MDCX */ |
| if (memcmp(&conn->end.addr, &addr_unset, sizeof(addr_unset)) == 0) |
| return 0; |
| |
| if (endp_osmux_state_check(endp, conn, true) < 0) |
| return 0; |
| |
| LOGP(DLMGCP, LOGL_DEBUG, |
| "sending OSMUX dummy load to %s CID %u\n", |
| inet_ntoa(conn->end.addr), conn->osmux.cid); |
| |
| return mgcp_udp_send(osmux_fd.fd, &conn->end.addr, |
| htons(endp->cfg->osmux_port), buf, sizeof(buf)); |
| } |
| |
| /* bsc-nat allocates/releases the Osmux circuit ID. +7 to round up to 8 bit boundary. */ |
| static uint8_t osmux_cid_bitmap[(OSMUX_CID_MAX + 1 + 7) / 8]; |
| |
| /*! count the number of taken OSMUX cids. |
| * \returns number of OSMUX cids in use */ |
| int osmux_used_cid(void) |
| { |
| int i, j, used = 0; |
| |
| for (i = 0; i < sizeof(osmux_cid_bitmap); i++) { |
| for (j = 0; j < 8; j++) { |
| if (osmux_cid_bitmap[i] & (1 << j)) |
| used += 1; |
| } |
| } |
| |
| return used; |
| } |
| |
| /*! take a free OSMUX cid. |
| * \returns OSMUX cid */ |
| int osmux_get_cid(void) |
| { |
| int i, j; |
| |
| for (i = 0; i < sizeof(osmux_cid_bitmap); i++) { |
| for (j = 0; j < 8; j++) { |
| if (osmux_cid_bitmap[i] & (1 << j)) |
| continue; |
| |
| osmux_cid_bitmap[i] |= (1 << j); |
| LOGP(DLMGCP, LOGL_DEBUG, |
| "Allocating Osmux CID %u from pool\n", (i * 8) + j); |
| return (i * 8) + j; |
| } |
| } |
| |
| LOGP(DLMGCP, LOGL_ERROR, "All Osmux circuits are in use!\n"); |
| return -1; |
| } |
| |
| /*! put back a no longer used OSMUX cid. |
| * \param[in] osmux_cid OSMUX cid */ |
| void osmux_put_cid(uint8_t osmux_cid) |
| { |
| LOGP(DLMGCP, LOGL_DEBUG, "Osmux CID %u is back to the pool\n", osmux_cid); |
| osmux_cid_bitmap[osmux_cid / 8] &= ~(1 << (osmux_cid % 8)); |
| } |