| /* |
| * (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 <netinet/in.h> |
| #include <osmocom/core/msgb.h> |
| #include <osmocom/core/talloc.h> |
| |
| #include <osmocom/netif/osmux.h> |
| #include <osmocom/netif/rtp.h> |
| |
| #include <openbsc/mgcp.h> |
| #include <openbsc/mgcp_internal.h> |
| #include <openbsc/osmux.h> |
| |
| #define OSMUX_PORT 1984 |
| |
| static struct osmo_fd osmux_fd; |
| |
| /* TODO: expire old handles.. */ |
| 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; |
| }; |
| |
| static void *osmux; |
| |
| static void osmux_deliver(struct msgb *batch_msg, void *data) |
| { |
| struct osmux_handle *handle = data; |
| struct sockaddr_in out = { |
| .sin_family = AF_INET, |
| .sin_port = handle->rem_port, |
| }; |
| char buf[4096]; |
| |
| memcpy(&out.sin_addr, &handle->rem_addr, sizeof(handle->rem_addr)); |
| |
| osmux_snprintf(buf, sizeof(buf), batch_msg); |
| LOGP(DMGCP, LOGL_DEBUG, "OSMUX delivering batch to addr=%s: %s\n", |
| inet_ntoa(out.sin_addr), buf); |
| |
| sendto(osmux_fd.fd, batch_msg->data, batch_msg->len, 0, |
| (struct sockaddr *)&out, sizeof(out)); |
| } |
| |
| static struct osmux_in_handle * |
| osmux_handle_lookup(struct mgcp_config *cfg, struct in_addr *addr, int rem_port) |
| { |
| struct osmux_handle *h; |
| |
| /* Lookup for existing OSMUX handle for this destination address. */ |
| 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(DMGCP, LOGL_DEBUG, "using existing OSMUX handle " |
| "for addr=%s:%d\n", |
| inet_ntoa(*addr), ntohs(rem_port)); |
| goto out; |
| } |
| } |
| |
| /* Does not exist, allocate it. */ |
| h = talloc_zero(osmux, struct osmux_handle); |
| if (!h) |
| return NULL; |
| h->rem_addr = *addr; |
| h->rem_port = rem_port; |
| |
| h->in = talloc_zero(osmux, struct osmux_in_handle); |
| if (!h->in) { |
| talloc_free(h); |
| return NULL; |
| } |
| |
| h->in->osmux_seq = 0; /* sequence number to start OSmux message from */ |
| h->in->batch_factor = cfg->osmux_batch; |
| h->in->deliver = osmux_deliver; |
| osmux_xfrm_input_init(h->in); |
| h->in->data = h; |
| |
| llist_add(&h->head, &osmux_handle_list); |
| |
| LOGP(DMGCP, LOGL_DEBUG, "created new OSMUX handle for addr=%s:%d\n", |
| inet_ntoa(*addr), ntohs(rem_port)); |
| out: |
| return h->in; |
| } |
| |
| int osmux_xfrm_to_osmux(int type, char *buf, int rc, struct mgcp_endpoint *endp) |
| { |
| int ret, port; |
| struct msgb *msg; |
| struct in_addr *addr; |
| struct osmux_in_handle *in; |
| |
| msg = msgb_alloc(4096, "RTP"); |
| if (!msg) |
| return 0; |
| |
| memcpy(msg->data, buf, rc); |
| msgb_put(msg, rc); |
| |
| switch(type) { |
| case MGCP_DEST_NET: |
| addr = &endp->net_end.addr; |
| port = htons(OSMUX_PORT); |
| break; |
| case MGCP_DEST_BTS: |
| addr = &endp->bts_end.addr; |
| port = endp->bts_end.rtp_port; |
| break; |
| default: |
| /* Should not ever happen */ |
| LOGP(DMGCP, LOGL_ERROR, "Bad type %d. Fix your code.\n", type); |
| msgb_free(msg); |
| return 0; |
| } |
| |
| if (port == 0) { |
| LOGP(DMGCP, LOGL_ERROR, "0x%x remote end not known yet.\n", |
| ENDPOINT_NUMBER(endp)); |
| msgb_free(msg); |
| return 0; |
| } |
| |
| /* Lookup for osmux input handle that munches this RTP frame */ |
| in = osmux_handle_lookup(endp->cfg, addr, port); |
| if (!in) { |
| LOGP(DMGCP, LOGL_ERROR, "No osmux handle, aborting\n"); |
| msgb_free(msg); |
| return 0; |
| } |
| |
| LOGP(DMGCP, LOGL_DEBUG, "Osmux uses cid=%u from endpoint=%d (active=%d)\n", |
| endp->ci, ENDPOINT_NUMBER(endp), endp->allocated); |
| |
| while ((ret = osmux_xfrm_input(in, msg, endp->ci)) > 0) { |
| /* batch full, build and deliver it */ |
| osmux_xfrm_input_deliver(in); |
| } |
| return 0; |
| } |
| |
| static struct mgcp_endpoint * |
| endpoint_lookup(struct mgcp_config *cfg, int cid, |
| struct in_addr *from_addr, int type) |
| { |
| struct mgcp_endpoint *tmp = NULL; |
| int i; |
| |
| /* Lookup for the endpoint that corresponds to this port */ |
| for (i=0; i<cfg->trunk.number_endpoints; i++) { |
| struct in_addr *this; |
| |
| tmp = &cfg->trunk.endpoints[i]; |
| |
| if (!tmp->allocated) |
| continue; |
| |
| switch(type) { |
| case MGCP_DEST_NET: |
| this = &tmp->net_end.addr; |
| break; |
| case MGCP_DEST_BTS: |
| this = &tmp->bts_end.addr; |
| break; |
| default: |
| /* Should not ever happen */ |
| LOGP(DMGCP, LOGL_ERROR, "Bad type %d. Fix your code.\n", type); |
| return NULL; |
| } |
| |
| if ((tmp->ci & 0xFF) == cid && this->s_addr == from_addr->s_addr) |
| return tmp; |
| } |
| |
| LOGP(DMGCP, 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 sockaddr_in addr; |
| |
| mgcp_send(endp, MGCP_DEST_NET, 1, &addr, (char *)msg->data, msg->len); |
| msgb_free(msg); |
| } |
| |
| static void scheduled_tx_bts_cb(struct msgb *msg, void *data) |
| { |
| struct mgcp_endpoint *endp = data; |
| struct sockaddr_in addr; |
| |
| mgcp_send(endp, MGCP_DEST_BTS, 1, &addr, (char *)msg->data, msg->len); |
| 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(DMGCP, 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(DMGCP, LOGL_ERROR, "cannot receive message\n"); |
| return NULL; |
| } |
| msgb_put(msg, ret); |
| |
| return msg; |
| } |
| |
| int osmux_read_from_bsc_nat_cb(struct osmo_fd *ofd, unsigned int what) |
| { |
| struct msgb *msg; |
| struct osmux_hdr *osmuxh; |
| struct llist_head list; |
| struct sockaddr_in addr; |
| struct mgcp_config *cfg = ofd->data; |
| char buf[4096]; |
| |
| msg = osmux_recv(ofd, &addr); |
| if (!msg) |
| return -1; |
| |
| /* not any further processing dummy messages */ |
| if (msg->data[0] == MGCP_DUMMY_LOAD) |
| goto out; |
| |
| osmux_snprintf(buf, sizeof(buf), msg); |
| LOGP(DMGCP, LOGL_DEBUG, "received OSMUX message from " |
| "BSC NAT (len=%d) %s\n", msg->len, buf); |
| |
| 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); |
| if (!endp) { |
| LOGP(DMGCP, LOGL_ERROR, |
| "Cannot find an endpoint for circuit_id=%d\n", |
| osmuxh->circuit_id); |
| goto out; |
| } |
| |
| LOGP(DMGCP, LOGL_DEBUG, |
| "sending extracted RTP from OSMUX to BSC via endpoint=%u " |
| "(allocated=%d)\n", ENDPOINT_NUMBER(endp), endp->allocated); |
| |
| osmux_xfrm_output(osmuxh, &endp->osmux_out, &list); |
| osmux_tx_sched(&list, scheduled_tx_bts_cb, endp); |
| } |
| out: |
| msgb_free(msg); |
| return 0; |
| } |
| |
| /* |
| * Try to figure out where it came from and enter the rtp_port |
| */ |
| static int osmux_handle_dummy(struct mgcp_config *cfg, |
| struct sockaddr_in *addr, struct msgb *msg) |
| { |
| struct mgcp_endpoint *endp; |
| uint32_t ci; |
| |
| if (msg->len < 1 + sizeof(ci)) |
| goto out; |
| |
| /* extract the CI from the dummy message */ |
| memcpy(&ci, &msg->data[1], sizeof(ci)); |
| ci = ntohl(ci); |
| |
| endp = endpoint_lookup(cfg, ci & 0xff, &addr->sin_addr, MGCP_DEST_BTS); |
| if (!endp) { |
| LOGP(DMGCP, LOGL_ERROR, "Can not find CI=%d\n", ci & 0xff); |
| goto out; |
| } |
| |
| if (endp->bts_end.rtp_port == 0) { |
| endp->bts_end.rtp_port = addr->sin_port; |
| LOGP(DMGCP, LOGL_NOTICE, "0x%x found BTS on endpoint %s:%d\n", |
| ENDPOINT_NUMBER(endp), |
| inet_ntoa(addr->sin_addr), htons(addr->sin_port)); |
| } |
| 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 llist_head list; |
| struct sockaddr_in addr; |
| struct mgcp_config *cfg = ofd->data; |
| char buf[4096]; |
| |
| msg = osmux_recv(ofd, &addr); |
| if (!msg) |
| return -1; |
| |
| /* not any further processing dummy messages */ |
| if (msg->data[0] == MGCP_DUMMY_LOAD) |
| return osmux_handle_dummy(cfg, &addr, msg); |
| |
| osmux_snprintf(buf, sizeof(buf), msg); |
| LOGP(DMGCP, LOGL_DEBUG, |
| "received OSMUX message from BSC(%s:%d) (len=%d) %s\n", |
| inet_ntoa(addr.sin_addr), ntohs(addr.sin_port), |
| msg->len, buf); |
| |
| 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); |
| if (!endp) { |
| LOGP(DMGCP, LOGL_ERROR, |
| "Cannot find an endpoint for circuit_id=%d\n", |
| osmuxh->circuit_id); |
| goto out; |
| } |
| |
| if (endp->bts_end.rtp_port == 0) { |
| endp->bts_end.rtp_port = addr.sin_port; |
| LOGP(DMGCP, LOGL_NOTICE, "0x%x found BTS on endpoint %s:%d\n", |
| ENDPOINT_NUMBER(endp), |
| inet_ntoa(addr.sin_addr), htons(addr.sin_port)); |
| } |
| |
| LOGP(DMGCP, LOGL_DEBUG, |
| "sending extracted RTP from OSMUX to MSC via endpoint=%u " |
| "(allocated=%d)\n", ENDPOINT_NUMBER(endp), endp->allocated); |
| |
| osmux_xfrm_output(osmuxh, &endp->osmux_out, &list); |
| osmux_tx_sched(&list, scheduled_tx_net_cb, endp); |
| } |
| 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(DMGCP, LOGL_ERROR, "wrong role for OSMUX\n"); |
| return -1; |
| } |
| osmux_fd.data = cfg; |
| |
| ret = mgcp_create_bind("0.0.0.0", &osmux_fd, OSMUX_PORT); |
| if (ret < 0) { |
| LOGP(DMGCP, LOGL_ERROR, "cannot bind OSMUX socket\n"); |
| return ret; |
| } |
| osmux_fd.when |= BSC_FD_READ; |
| |
| ret = osmo_fd_register(&osmux_fd); |
| if (ret < 0) { |
| LOGP(DMGCP, LOGL_ERROR, "cannot register OSMUX socket\n"); |
| return ret; |
| } |
| cfg->osmux_init = 1; |
| |
| return 0; |
| } |
| |
| int osmux_enable_endpoint(struct mgcp_endpoint *endp, int role) |
| { |
| /* 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 (endp->ci), 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 256 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 / 256; |
| |
| if (!endp->cfg->osmux_init) { |
| if (osmux_init(role, endp->cfg) < 0) { |
| LOGP(DMGCP, LOGL_ERROR, "Cannot init OSMUX\n"); |
| return -1; |
| } |
| LOGP(DMGCP, LOGL_NOTICE, "OSMUX requested, ENABLING.\n"); |
| } |
| |
| osmux_xfrm_output_init(&endp->osmux_out, |
| (endp->ci * rtp_ssrc_winlen) + |
| (random() % rtp_ssrc_winlen)); |
| |
| switch (endp->cfg->role) { |
| case MGCP_BSC_NAT: |
| endp->type = MGCP_OSMUX_BSC_NAT; |
| break; |
| case MGCP_BSC: |
| endp->type = MGCP_OSMUX_BSC; |
| break; |
| } |
| endp->osmux = 1; |
| |
| return 0; |
| } |
| |
| /* 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. |
| */ |
| int osmux_send_dummy(struct mgcp_endpoint *endp) |
| { |
| uint32_t ci_be; |
| char buf[1 + sizeof(uint32_t)]; |
| |
| ci_be = htonl(endp->ci); |
| buf[0] = MGCP_DUMMY_LOAD; |
| memcpy(&buf[1], &ci_be, sizeof(ci_be)); |
| |
| LOGP(DMGCP, LOGL_DEBUG, "sending OSMUX dummy load to %s\n", |
| inet_ntoa(endp->net_end.addr)); |
| |
| return mgcp_udp_send(osmux_fd.fd, &endp->net_end.addr, |
| htons(OSMUX_PORT), buf, sizeof(buf)); |
| } |