diff options
Diffstat (limited to 'src/libmgcp/mgcp_osmux.c')
-rw-r--r-- | src/libmgcp/mgcp_osmux.c | 586 |
1 files changed, 586 insertions, 0 deletions
diff --git a/src/libmgcp/mgcp_osmux.c b/src/libmgcp/mgcp_osmux.c new file mode 100644 index 000000000..b46a80e7f --- /dev/null +++ b/src/libmgcp/mgcp_osmux.c @@ -0,0 +1,586 @@ +/* + * (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[(OSMUX_CID_MAX + 1) / 8]; + +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)); +} |