| /* |
| * (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 <openbsc/mgcp.h> |
| #include <openbsc/mgcp_internal.h> |
| #include <openbsc/osmux.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; |
| |
| 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, |
| }; |
| |
| 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); |
| } |
| |
| static struct osmux_handle * |
| osmux_handle_find_get(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)); |
| h->refcnt++; |
| return h; |
| } |
| } |
| |
| return NULL; |
| } |
| |
| static void osmux_handle_put(struct osmux_in_handle *in) |
| { |
| struct osmux_handle *h; |
| |
| /* Lookup for existing OSMUX handle for this destination address. */ |
| llist_for_each_entry(h, &osmux_handle_list, head) { |
| if (h->in == in) { |
| if (--h->refcnt == 0) { |
| LOGP(DMGCP, LOGL_INFO, |
| "Releasing unused osmux handle for %s:%d\n", |
| inet_ntoa(h->rem_addr), |
| ntohs(h->rem_port)); |
| LOGP(DMGCP, 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(DMGCP, LOGL_ERROR, "cannot find Osmux input handle %p\n", in); |
| } |
| |
| 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; |
| } |
| |
| h->in->osmux_seq = 0; /* sequence number to start OSmux message from */ |
| 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; |
| 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)); |
| |
| return h; |
| } |
| |
| 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; |
| } |
| |
| int osmux_xfrm_to_osmux(int type, char *buf, int rc, struct mgcp_endpoint *endp) |
| { |
| int ret; |
| struct msgb *msg; |
| |
| msg = msgb_alloc(4096, "RTP"); |
| if (!msg) |
| return 0; |
| |
| memcpy(msg->data, buf, rc); |
| msgb_put(msg, rc); |
| |
| while ((ret = osmux_xfrm_input(endp->osmux.in, msg, endp->osmux.cid)) > 0) { |
| /* batch full, build and deliver it */ |
| osmux_xfrm_input_deliver(endp->osmux.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->osmux.cid == 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 = { |
| .sin_addr = endp->net_end.addr, |
| .sin_port = endp->net_end.rtp_port, |
| }; |
| |
| endp->bts_end.octets += msg->len; |
| endp->bts_end.packets++; |
| |
| 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 = { |
| .sin_addr = endp->bts_end.addr, |
| .sin_port = endp->bts_end.rtp_port, |
| }; |
| |
| endp->net_end.octets += msg->len; |
| endp->net_end.packets++; |
| |
| 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; |
| } |
| |
| #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 llist_head list; |
| struct sockaddr_in addr; |
| struct mgcp_config *cfg = ofd->data; |
| uint32_t rem; |
| |
| msg = osmux_recv(ofd, &addr); |
| if (!msg) |
| return -1; |
| |
| /* 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); |
| if (!endp) { |
| LOGP(DMGCP, LOGL_ERROR, |
| "Cannot find an endpoint for circuit_id=%d\n", |
| osmuxh->circuit_id); |
| goto out; |
| } |
| endp->osmux.stats.octets += osmux_chunk_length(msg, rem); |
| endp->osmux.stats.chunks++; |
| rem = msg->len; |
| |
| osmux_xfrm_output(osmuxh, &endp->osmux.out, &list); |
| osmux_tx_sched(&list, scheduled_tx_bts_cb, endp); |
| } |
| 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) |
| { |
| struct mgcp_endpoint *endp; |
| uint8_t osmux_cid; |
| |
| if (msg->len < 1 + sizeof(osmux_cid)) { |
| LOGP(DMGCP, LOGL_ERROR, |
| "Discarding truncated Osmux dummy load\n"); |
| goto out; |
| } |
| |
| LOGP(DMGCP, LOGL_DEBUG, "Received Osmux dummy load from %s\n", |
| inet_ntoa(addr->sin_addr)); |
| |
| if (!cfg->osmux) { |
| LOGP(DMGCP, LOGL_ERROR, |
| "bsc wants to use Osmux but bsc-nat did not request it\n"); |
| goto out; |
| } |
| |
| /* extract the osmux CID from the dummy message */ |
| memcpy(&osmux_cid, &msg->data[1], sizeof(osmux_cid)); |
| |
| endp = endpoint_lookup(cfg, osmux_cid, &addr->sin_addr, MGCP_DEST_BTS); |
| if (!endp) { |
| LOGP(DMGCP, LOGL_ERROR, |
| "Cannot find endpoint for Osmux CID %d\n", osmux_cid); |
| goto out; |
| } |
| |
| if (endp->osmux.state == OSMUX_STATE_ENABLED) |
| goto out; |
| |
| if (osmux_enable_endpoint(endp, OSMUX_ROLE_BSC_NAT, |
| &addr->sin_addr, addr->sin_port) < 0 ){ |
| LOGP(DMGCP, LOGL_ERROR, |
| "Could not enable osmux in endpoint %d\n", |
| ENDPOINT_NUMBER(endp)); |
| goto out; |
| } |
| |
| LOGP(DMGCP, LOGL_INFO, "Enabling osmux in endpoint %d for %s:%u\n", |
| ENDPOINT_NUMBER(endp), inet_ntoa(addr->sin_addr), |
| ntohs(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; |
| uint32_t rem; |
| |
| 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); |
| |
| 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); |
| if (!endp) { |
| LOGP(DMGCP, LOGL_ERROR, |
| "Cannot find an endpoint for circuit_id=%d\n", |
| osmuxh->circuit_id); |
| goto out; |
| } |
| endp->osmux.stats.octets += osmux_chunk_length(msg, rem); |
| endp->osmux.stats.chunks++; |
| rem = msg->len; |
| |
| 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(cfg->osmux_addr, &osmux_fd, cfg->osmux_port); |
| if (ret < 0) { |
| LOGP(DMGCP, 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(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, |
| 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 (endp->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 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->osmux.state == OSMUX_STATE_DISABLED) { |
| LOGP(DMGCP, LOGL_ERROR, "Endpoint %u didn't request Osmux\n", |
| ENDPOINT_NUMBER(endp)); |
| return -1; |
| } |
| |
| osmux_xfrm_output_init(&endp->osmux.out, |
| (endp->osmux.cid * rtp_ssrc_winlen) + |
| (random() % rtp_ssrc_winlen)); |
| |
| endp->osmux.in = osmux_handle_lookup(endp->cfg, addr, port); |
| if (!endp->osmux.in) { |
| LOGP(DMGCP, LOGL_ERROR, "Cannot allocate input osmux handle\n"); |
| return -1; |
| } |
| if (!osmux_xfrm_input_open_circuit(endp->osmux.in, endp->osmux.cid, |
| endp->cfg->osmux_dummy)) { |
| LOGP(DMGCP, LOGL_ERROR, "Cannot open osmux circuit %u\n", |
| endp->osmux.cid); |
| return -1; |
| } |
| |
| 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.state = OSMUX_STATE_ENABLED; |
| |
| return 0; |
| } |
| |
| void osmux_disable_endpoint(struct mgcp_endpoint *endp) |
| { |
| LOGP(DMGCP, LOGL_INFO, "Releasing endpoint %u using Osmux CID %u\n", |
| ENDPOINT_NUMBER(endp), endp->osmux.cid); |
| osmux_xfrm_input_close_circuit(endp->osmux.in, endp->osmux.cid); |
| endp->osmux.state = OSMUX_STATE_DISABLED; |
| endp->osmux.cid = -1; |
| osmux_handle_put(endp->osmux.in); |
| } |
| |
| void osmux_release_cid(struct mgcp_endpoint *endp) |
| { |
| if (endp->osmux.allocated_cid >= 0) |
| osmux_put_cid(endp->osmux.allocated_cid); |
| endp->osmux.allocated_cid = -1; |
| } |
| |
| void osmux_allocate_cid(struct mgcp_endpoint *endp) |
| { |
| osmux_release_cid(endp); |
| endp->osmux.allocated_cid = osmux_get_cid(); |
| } |
| |
| /* 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) |
| { |
| char buf[1 + sizeof(uint8_t)]; |
| struct in_addr addr_unset = {}; |
| |
| buf[0] = MGCP_DUMMY_LOAD; |
| memcpy(&buf[1], &endp->osmux.cid, sizeof(endp->osmux.cid)); |
| |
| /* Wait until we have the connection information from MDCX */ |
| if (memcmp(&endp->net_end.addr, &addr_unset, sizeof(addr_unset)) == 0) |
| return 0; |
| |
| if (endp->osmux.state == OSMUX_STATE_ACTIVATING) { |
| if (osmux_enable_endpoint(endp, OSMUX_ROLE_BSC, |
| &endp->net_end.addr, |
| htons(endp->cfg->osmux_port)) < 0) { |
| LOGP(DMGCP, LOGL_ERROR, |
| "Could not activate osmux in endpoint %d\n", |
| ENDPOINT_NUMBER(endp)); |
| } |
| LOGP(DMGCP, LOGL_ERROR, |
| "Osmux CID %u for %s:%u is now enabled\n", |
| endp->osmux.cid, inet_ntoa(endp->net_end.addr), |
| endp->cfg->osmux_port); |
| } |
| LOGP(DMGCP, LOGL_DEBUG, |
| "sending OSMUX dummy load to %s CID %u\n", |
| inet_ntoa(endp->net_end.addr), endp->osmux.cid); |
| |
| return mgcp_udp_send(osmux_fd.fd, &endp->net_end.addr, |
| htons(endp->cfg->osmux_port), buf, sizeof(buf)); |
| } |
| |
| /* bsc-nat allocates/releases the Osmux circuit ID */ |
| static uint8_t osmux_cid_bitmap[16]; |
| |
| 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; |
| } |
| |
| 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(DMGCP, LOGL_DEBUG, |
| "Allocating Osmux CID %u from pool\n", (i * 8) + j); |
| return (i * 8) + j; |
| } |
| } |
| |
| LOGP(DMGCP, LOGL_ERROR, "All Osmux circuits are in use!\n"); |
| return -1; |
| } |
| |
| void osmux_put_cid(uint8_t osmux_cid) |
| { |
| LOGP(DMGCP, LOGL_DEBUG, "Osmux CID %u is back to the pool\n", osmux_cid); |
| osmux_cid_bitmap[osmux_cid / 8] &= ~(1 << (osmux_cid % 8)); |
| } |