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osmo-mgw/src/libosmo-mgcp-client/mgcp_client_endpoint_fsm.c

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/* FSM to manage multiple connections of an MGW endpoint
*
* (C) 2018-2019 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de>
* All Rights Reserved
*
* Author: Neels Hofmeyr <neels@hofmeyr.de>
*
* 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 <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <osmocom/core/fsm.h>
#include <osmocom/core/byteswap.h>
#include <osmocom/core/tdef.h>
#include <osmocom/core/sockaddr_str.h>
#include <osmocom/mgcp_client/mgcp_client_endpoint_fsm.h>
#define LOG_CI(ci, level, fmt, args...) do { \
if (!ci || !ci->ep) \
LOGP(DLMGCP, level, "(unknown MGW endpoint) " fmt, ## args); \
else \
LOG_MGCPC_EP(ci->ep, level, "CI[%d] %s%s%s: " fmt, \
(int)(ci - ci->ep->ci), \
ci->label ? : "-", \
ci->mgcp_ci_str[0] ? " CI=" : "", \
ci->mgcp_ci_str[0] ? ci->mgcp_ci_str : "", \
## args); \
} while(0)
#define LOG_CI_VERB(ci, level, fmt, args...) do { \
if (ci->verb_info.addr[0]) \
LOG_CI(ci, level, "%s %s:%u: " fmt, \
osmo_mgcp_verb_name(ci->verb), ci->verb_info.addr, ci->verb_info.port, \
## args); \
else \
LOG_CI(ci, level, "%s: " fmt, \
osmo_mgcp_verb_name(ci->verb), \
## args); \
} while(0)
enum osmo_mgcpc_ep_fsm_state {
OSMO_MGCPC_EP_ST_UNUSED = 0,
OSMO_MGCPC_EP_ST_WAIT_MGW_RESPONSE,
OSMO_MGCPC_EP_ST_IN_USE,
};
enum osmo_mgcpc_ep_fsm_event {
_OSMO_MGCPC_EP_EV_LAST = 0,
/* and MGW response events are allocated dynamically */
};
#define FIRST_CI_EVENT (_OSMO_MGCPC_EP_EV_LAST + (_OSMO_MGCPC_EP_EV_LAST & 1)) /* rounded up to even nr */
#define USABLE_CI ((32 - FIRST_CI_EVENT)/2)
#define EV_TO_CI_IDX(event) ((event - FIRST_CI_EVENT) / 2)
#define CI_EV_SUCCESS(ci) (FIRST_CI_EVENT + (((ci) - ci->ep->ci) * 2))
#define CI_EV_FAILURE(ci) (CI_EV_SUCCESS(ci) + 1)
static struct osmo_fsm osmo_mgcpc_ep_fsm;
struct fsm_notify {
struct llist_head entry;
struct osmo_fsm_inst *fi;
uint32_t success;
uint32_t failure;
void *data;
};
/*! One connection on an endpoint, corresponding to a connection identifier (CI) as returned by the MGW.
* An endpoint has a fixed number of slots of these, which may or may not be in use.
*/
struct osmo_mgcpc_ep_ci {
struct osmo_mgcpc_ep *ep;
bool occupied;
char label[64];
struct osmo_fsm_inst *mgcp_client_fi;
bool pending;
bool sent;
enum mgcp_verb verb;
struct mgcp_conn_peer verb_info;
struct fsm_notify notify;
bool got_port_info;
struct mgcp_conn_peer rtp_info;
char mgcp_ci_str[MGCP_CONN_ID_LENGTH];
};
/*! An MGW endpoint with N connections, like "rtpbridge/23@mgw". */
struct osmo_mgcpc_ep {
/*! MGCP client connection to the MGW. */
struct mgcp_client *mgcp_client;
struct osmo_fsm_inst *fi;
/*! Endpoint string; at first this might be a wildcard, and upon the first CRCX OK response, this will reflect
* the endpoint name returned by the MGW. */
char endpoint[MGCP_ENDPOINT_MAXLEN];
/*! Timeout definitions used for this endpoint, see osmo_mgcpc_ep_fsm_timeouts. */
const struct osmo_tdef *T_defs;
/*! True as soon as the first CRCX OK is received. The endpoint name may be determined by the first CRCX
* response, so to dispatch any other messages, the FSM instance *must* wait for the first CRCX OK to arrive
* first. Once the endpoint name is pinpointed, any amount of operations may be dispatched concurrently. */
bool first_crcx_complete;
/*! Endpoint connection slots. Note that each connection has its own set of FSM event numbers to signal success
* and failure, depending on its index within this array. See CI_EV_SUCCESS and CI_EV_FAILURE. */
struct osmo_mgcpc_ep_ci ci[USABLE_CI];
/*! Internal use: if a function keeps an fsm_notify for later dispatch while already clearing or re-using the
* ci[], the fsm_notify should be kept here to also get canceled by osmo_mgcpc_ep_cancel_notify(). */
struct llist_head background_notify;
};
const struct value_string osmo_mgcp_verb_names[] = {
{ MGCP_VERB_CRCX, "CRCX" },
{ MGCP_VERB_MDCX, "MDCX" },
{ MGCP_VERB_DLCX, "DLCX" },
{ MGCP_VERB_AUEP, "AUEP" },
{ MGCP_VERB_RSIP, "RSIP" },
{}
};
static void osmo_mgcpc_ep_count(struct osmo_mgcpc_ep *ep, int *occupied, int *pending_not_sent,
int *waiting_for_response);
static struct osmo_mgcpc_ep_ci *osmo_mgcpc_ep_check_ci(struct osmo_mgcpc_ep_ci *ci)
{
if (!ci)
return NULL;
if (!ci->ep)
return NULL;
if (ci < ci->ep->ci || ci >= &ci->ep->ci[USABLE_CI])
return NULL;
return ci;
}
static struct osmo_mgcpc_ep_ci *osmo_mgcpc_ep_ci_for_event(struct osmo_mgcpc_ep *ep, uint32_t event)
{
int idx;
if (event < FIRST_CI_EVENT)
return NULL;
idx = EV_TO_CI_IDX(event);
if (idx >= sizeof(ep->ci))
return NULL;
return osmo_mgcpc_ep_check_ci(&ep->ci[idx]);
}
const char *osmo_mgcpc_ep_name(const struct osmo_mgcpc_ep *ep)
{
if (!ep)
return "NULL";
if (ep->endpoint[0])
return ep->endpoint;
return osmo_fsm_inst_name(ep->fi);
}
/*! Get "local endpoint name" part of the endpoint name: (local-endpoint-name@domain-name)
*
* \param ep The MGCP Endpoint
* \returns the local endpoint name if found, NULL on error.
*/
const char *osmo_mgcpc_ep_local_name(const struct osmo_mgcpc_ep *ep)
{
static char buf[1024];
const char *sep;
OSMO_ASSERT(ep);
sep = strchr(ep->endpoint, '@');
if (!sep) {
OSMO_STRLCPY_ARRAY(buf, ep->endpoint);
return buf;
}
if (sep - ep->endpoint >= sizeof(buf))
return NULL;
memcpy(buf, ep->endpoint, sep - ep->endpoint);
buf[sep - ep->endpoint] = '\0';
return buf;
}
const char *mgcp_conn_peer_name(const struct mgcp_conn_peer *info)
{
/* I'd be fine with a smaller buffer and accept truncation, but gcc possibly refuses to build if
* this buffer is too small. */
static char buf[1024];
if (!info)
return "NULL";
if (info->endpoint[0]
&& info->addr[0])
snprintf(buf, sizeof(buf), "%s:%s:%u",
info->endpoint, info->addr, info->port);
else if (info->endpoint[0])
snprintf(buf, sizeof(buf), "%s", info->endpoint);
else if (info->addr[0])
snprintf(buf, sizeof(buf), "%s:%u", info->addr, info->port);
else
return "empty";
return buf;
}
const char *osmo_mgcpc_ep_ci_name(const struct osmo_mgcpc_ep_ci *ci)
{
const struct mgcp_conn_peer *rtp_info;
if (!ci)
return "NULL";
rtp_info = osmo_mgcpc_ep_ci_get_rtp_info(ci);
if (rtp_info)
return mgcp_conn_peer_name(rtp_info);
return osmo_mgcpc_ep_name(ci->ep);
}
const char *osmo_mgcpc_ep_ci_id(const struct osmo_mgcpc_ep_ci *ci)
{
if (!ci || !ci->mgcp_ci_str[0])
return NULL;
return ci->mgcp_ci_str;
}
struct mgcp_client *osmo_mgcpc_ep_client(const struct osmo_mgcpc_ep *ep)
{
if (!ep)
return NULL;
return ep->mgcp_client;
}
static struct value_string osmo_mgcpc_ep_fsm_event_names[33] = {};
static char osmo_mgcpc_ep_fsm_event_name_bufs[32][32] = {};
static void fill_event_names(void)
{
int i;
for (i = 0; i < (ARRAY_SIZE(osmo_mgcpc_ep_fsm_event_names) - 1); i++) {
if (i < _OSMO_MGCPC_EP_EV_LAST)
continue;
if (i < FIRST_CI_EVENT || EV_TO_CI_IDX(i) > USABLE_CI) {
osmo_mgcpc_ep_fsm_event_names[i] = (struct value_string){i, "Unused"};
continue;
}
snprintf(osmo_mgcpc_ep_fsm_event_name_bufs[i], sizeof(osmo_mgcpc_ep_fsm_event_name_bufs[i]),
"MGW Response for CI #%d", EV_TO_CI_IDX(i));
osmo_mgcpc_ep_fsm_event_names[i] = (struct value_string){i, osmo_mgcpc_ep_fsm_event_name_bufs[i]};
}
}
static __attribute__((constructor)) void osmo_mgcpc_ep_fsm_init(void)
{
OSMO_ASSERT(osmo_fsm_register(&osmo_mgcpc_ep_fsm) == 0);
fill_event_names();
}
struct osmo_mgcpc_ep *osmo_mgcpc_ep_fi_mgwep(struct osmo_fsm_inst *fi)
{
OSMO_ASSERT(fi);
OSMO_ASSERT(fi->fsm == &osmo_mgcpc_ep_fsm);
OSMO_ASSERT(fi->priv);
return fi->priv;
}
/*! Allocate an osmo_mgcpc_ep FSM.
* MGCP messages to set up the endpoint will be sent on the given mgcp_client, as soon as the first
* osmo_mgcpc_ep_ci_request() is invoked.
*
* IMPORTANT: To avoid use-after-free problems, using this FSM requires use of deferred FSM deallocation using
* osmo_fsm_set_dealloc_ctx(), e.g. using osmo_select_main_ctx(OTC_SELECT) with osmo_select_main_ctx() as main loop.
*
* A typical sequence of events would be:
*
* ep = osmo_mgcpc_ep_alloc(..., mgcp_client_rtpbridge_wildcard(client));
* ci_to_ran = osmo_mgcpc_ep_ci_add(ep);
* osmo_mgcpc_ep_ci_request(ci_to_ran, MGCP_VERB_CRCX, verb_info,
* my_call_fsm, MY_EVENT_MGCP_OK, MY_EVENT_MGCP_FAIL);
* ci_to_cn = osmo_mgcpc_ep_ci_add(ep);
* osmo_mgcpc_ep_ci_request(ci_to_cn, MGCP_VERB_CRCX, verb_info,
* my_call_fsm, MY_EVENT_MGCP_OK, MY_EVENT_MGCP_FAIL);
* ...
* osmo_mgcpc_ep_ci_request(ci_to_ran, MGCP_VERB_MDCX, ...);
* ...
* osmo_mgcpc_ep_clear(ep);
* ep = NULL;
*
* \param parent Parent FSM.
* \param parent_term_event Event to dispatch to the parent on termination of this FSM instance.
* \param mgcp_client Connection to the MGW.
* \param T_defs Timeout definitions to be used for FSM states, see osmo_mgcpc_ep_fsm_timeouts.
* \param fsm_id FSM instance ID.
* \param endpoint_str_fmt The endpoint string format to send to the MGW upon the first CRCX.
* See mgcp_client_rtpbridge_wildcard() for "rtpbridge" endpoints.
*/
struct osmo_mgcpc_ep *osmo_mgcpc_ep_alloc(struct osmo_fsm_inst *parent, uint32_t parent_term_event,
struct mgcp_client *mgcp_client,
const struct osmo_tdef *T_defs,
const char *fsm_id,
const char *endpoint_str_fmt, ...)
{
va_list ap;
struct osmo_fsm_inst *fi;
struct osmo_mgcpc_ep *ep;
int rc;
if (!mgcp_client)
return NULL;
fi = osmo_fsm_inst_alloc_child(&osmo_mgcpc_ep_fsm, parent, parent_term_event);
OSMO_ASSERT(fi);
osmo_fsm_inst_update_id(fi, fsm_id);
ep = talloc_zero(fi, struct osmo_mgcpc_ep);
OSMO_ASSERT(ep);
*ep = (struct osmo_mgcpc_ep){
.mgcp_client = mgcp_client,
.fi = fi,
.T_defs = T_defs,
};
INIT_LLIST_HEAD(&ep->background_notify);
fi->priv = ep;
va_start(ap, endpoint_str_fmt);
rc = vsnprintf(ep->endpoint, sizeof(ep->endpoint), endpoint_str_fmt ? : "", ap);
va_end(ap);
if (rc <= 0 || rc >= sizeof(ep->endpoint)) {
LOG_MGCPC_EP(ep, LOGL_ERROR, "Endpoint name too long or too short: %s\n",
ep->endpoint);
osmo_fsm_inst_term(ep->fi, OSMO_FSM_TERM_ERROR, 0);
return NULL;
}
return ep;
}
/*! Add a connection to an endpoint.
* Allocate a connection identifier slot in the osmo_mgcpc_ep instance, do not yet dispatch a CRCX.
* The CRCX is dispatched only upon the first osmo_mgcpc_ep_ci_request().
* \param ep Parent endpoint instance.
* \param label_fmt Label for logging.
*/
struct osmo_mgcpc_ep_ci *osmo_mgcpc_ep_ci_add(struct osmo_mgcpc_ep *ep,
const char *label_fmt, ...)
{
va_list ap;
int i;
struct osmo_mgcpc_ep_ci *ci;
for (i = 0; i < USABLE_CI; i++) {
ci = &ep->ci[i];
if (ci->occupied || ci->mgcp_client_fi)
continue;
*ci = (struct osmo_mgcpc_ep_ci){
.ep = ep,
.occupied = true,
};
if (label_fmt) {
va_start(ap, label_fmt);
vsnprintf(ci->label, sizeof(ci->label), label_fmt, ap);
va_end(ap);
}
return ci;
}
LOG_MGCPC_EP(ep, LOGL_ERROR,
"Cannot allocate another endpoint, all "
OSMO_STRINGIFY_VAL(USABLE_CI) " are in use\n");
return NULL;
}
static bool osmo_mgcpc_ep_fsm_check_state_chg_after_response(struct osmo_fsm_inst *fi);
static void on_failure(struct osmo_mgcpc_ep_ci *ci)
{
struct osmo_mgcpc_ep *ep = ci->ep;
struct fsm_notify notify;
int i;
if (!ci->occupied)
return;
/* When dispatching an event for this CI, the user may decide to trigger the next request for this conn right
* away. So we must be ready with a cleared *ci. Store the notify separately and clear before dispatching. */
notify = ci->notify;
/* Register the planned notification in ep->background_notify so we also catch any osmo_mgcpc_ep_cancel_notify()
* that might be triggered between clearing the ci and actually dispatching the event. */
llist_add(&notify.entry, &ep->background_notify);
*ci = (struct osmo_mgcpc_ep_ci){
.ep = ci->ep,
};
/* An MGCP failure typically means the endpoint becomes unusable, cancel all pending request (except DLCX).
* Particularly, if two CRCX were scheduled and the first fails, we must no longer dispatch the second CRCX. */
for (i = 0; i < ARRAY_SIZE(ep->ci); i++) {
struct osmo_mgcpc_ep_ci *other_ci = &ep->ci[i];
if (other_ci == ci)
continue;
if (!other_ci->occupied)
continue;
if (!other_ci->pending)
continue;
if (other_ci->sent)
continue;
if (other_ci->verb == MGCP_VERB_DLCX)
continue;
/* Just clear the pending request, don't fire more events than below. */
other_ci->pending = false;
}
/* If this check has terminated the FSM instance, don't fire any more events to prevent use-after-free problems.
* The endpoint FSM does dispatch a term event to its parent, and everything should be cleaned like that. */
if (!osmo_mgcpc_ep_fsm_check_state_chg_after_response(ep->fi)) {
/* The ep has deallocated, no need to llist_del(&notify.entry) here. */
return;
}
if (notify.fi)
osmo_fsm_inst_dispatch(notify.fi, notify.failure, notify.data);
llist_del(&notify.entry);
}
static int update_endpoint_name(struct osmo_mgcpc_ep_ci *ci, const char *new_endpoint_name)
{
struct osmo_mgcpc_ep *ep = ci->ep;
int rc;
int i;
if (!strcmp(ep->endpoint, new_endpoint_name)) {
/* Same endpoint name, nothing to do. */
return 0;
}
/* The endpoint name should only change on the very first CRCX response. */
if (ep->first_crcx_complete) {
LOG_CI(ci, LOGL_ERROR, "Reponse returned mismatching endpoint name."
" This is endpoint %s, instead received %s\n",
ep->endpoint, new_endpoint_name);
on_failure(ci);
return -EINVAL;
}
/* This is the first CRCX response, update endpoint name. */
rc = OSMO_STRLCPY_ARRAY(ep->endpoint, new_endpoint_name);
if (rc <= 0 || rc >= sizeof(ep->endpoint)) {
LOG_CI(ci, LOGL_ERROR, "Unable to copy endpoint name %s\n", osmo_quote_str(new_endpoint_name, -1));
osmo_mgcpc_ep_ci_dlcx(ci);
on_failure(ci);
return -ENOSPC;
}
/* Make sure already pending requests use this updated endpoint name. */
for (i = 0; i < ARRAY_SIZE(ep->ci); i++) {
struct osmo_mgcpc_ep_ci *other_ci = &ep->ci[i];
if (!other_ci->occupied)
continue;
if (!other_ci->pending)
continue;
if (other_ci->sent)
continue;
OSMO_STRLCPY_ARRAY(other_ci->verb_info.endpoint, ep->endpoint);
}
return 0;
}
static void on_success(struct osmo_mgcpc_ep_ci *ci, void *data)
{
struct mgcp_conn_peer *rtp_info;
if (!ci->occupied)
return;
ci->pending = false;
rtp_info = data;
switch (ci->verb) {
case MGCP_VERB_CRCX:
/* If we sent a wildcarded endpoint name on CRCX, we need to store the resulting endpoint
* name here. Also, we receive the MGW's RTP port information. */
osmo_strlcpy(ci->mgcp_ci_str, mgcp_conn_get_ci(ci->mgcp_client_fi),
sizeof(ci->mgcp_ci_str));
if (rtp_info->endpoint[0]) {
/* On errors, this instance might already be deallocated. Make sure to not access anything after
* error. */
if (update_endpoint_name(ci, rtp_info->endpoint))
return;
}
ci->ep->first_crcx_complete = true;
OSMO_ASSERT(rtp_info);
/* fall through */
case MGCP_VERB_MDCX:
/* Always update the received RTP ip/port information, since MGW
* may provide new one after remote end params changed */
if (rtp_info) {
ci->got_port_info = true;
ci->rtp_info = *rtp_info;
}
break;
default:
break;
}
LOG_CI(ci, LOGL_DEBUG, "received successful response to %s: RTP=%s%s\n",
osmo_mgcp_verb_name(ci->verb),
mgcp_conn_peer_name(ci->got_port_info? &ci->rtp_info : NULL),
ci->notify.fi ? "" : " (not sending a notification)");
/* Below ordering is a delicate decision:
*
* We want to
* - emit the resulting event to ci->notify.fi,
* - check whether we want to tx the next pending MGCP message.
* Both these steps may terminate (=deallocate) the ep.
* So whichever one goes first may cause a use-after-free in the other.
*
* When dispatching the FSM event, we don't get an rc indicating dealloc of the FSM -- it may deallocate and we
* cannot tell. The common mechanism for that is osmo_fsm_set_dealloc_ctx(OTC_SELECT) and query the still
* allocated FSM state after termination (here we would check 'if (ci->ep != NULL)'), but we cannot assume the
* caller has actually set up an osmo_fsm_set_dealloc_ctx(). At time of writing, e.g. osmo-hnbgw does not use
* it.
*
* In osmo_mgcpc_ep_fsm_check_state_chg_after_response(), we do get an rc: false means FSM has terminated.
* On termination, the ep emits a term event to the FSM's parent.
* That may cause the notify.fi to be terminated in turn, depending on how the caller set things up.
* So: we cannot store notify.fi before, then call osmo_mgcpc_ep_fsm_check_state_chg_after_response(), and then
* emit the event, because notify.fi may have deallocated. We cannot look up whether
* osmo_mgcpc_ep_cancel_notify() has been called, because ci may have deallocated along with ci->ep.
*
* We have to skip emitting below success event in case the ep is now terminated.
* - It may be the final DLCX OK: not a problem, osmo_mgcpc_ep_ci_dlcx() has no notify args on purpose, so we do
* make all callers not set a notify event for DLCX by design. notify.fi should always be NULL when the final
* DLCX OK terminates the local endpoint state.
* - It may also be sudden termination due to a bad problem, in which case we shouldn't emit success.
* The osmo_fsm_inst.parent_term_event should suffice as feedback to the caller.
*/
if (osmo_mgcpc_ep_fsm_check_state_chg_after_response(ci->ep->fi) == false) {
/* false means, the ci->ep has been terminated. */
return;
}
if (ci->notify.fi)
osmo_fsm_inst_dispatch(ci->notify.fi, ci->notify.success, ci->notify.data);
}
/*! Return the MGW's local RTP port information for this connection, i.e. the local port that MGW is receiving on, as
* returned by the last CRCX-OK / MDCX-OK message. */
const struct mgcp_conn_peer *osmo_mgcpc_ep_ci_get_rtp_info(const struct osmo_mgcpc_ep_ci *ci)
{
ci = osmo_mgcpc_ep_check_ci((struct osmo_mgcpc_ep_ci*)ci);
if (!ci)
return NULL;
if (!ci->got_port_info)
return NULL;
return &ci->rtp_info;
}
/*! Return the MGW's remote RTP port information for this connection, i.e. the remote RTP port that the MGW is sending
* to, as sent to the MGW by the last CRCX / MDCX message. */
const struct mgcp_conn_peer *osmo_mgcpc_ep_ci_get_remote_rtp_info(const struct osmo_mgcpc_ep_ci *ci)
{
ci = osmo_mgcpc_ep_check_ci((struct osmo_mgcpc_ep_ci*)ci);
if (!ci)
return NULL;
return &ci->verb_info;
}
/*! Return the MGW's RTP port information for this connection, as returned by the last CRCX/MDCX OK message. */
bool osmo_mgcpc_ep_ci_get_crcx_info_to_sockaddr(const struct osmo_mgcpc_ep_ci *ci, struct sockaddr_storage *dest)
{
const struct mgcp_conn_peer *rtp_info;
int family;
struct sockaddr_in *sin;
struct sockaddr_in6 *sin6;
rtp_info = osmo_mgcpc_ep_ci_get_rtp_info(ci);
if (!rtp_info)
return false;
family = osmo_ip_str_type(rtp_info->addr);
switch (family) {
case AF_INET:
sin = (struct sockaddr_in *)dest;
sin->sin_family = AF_INET;
sin->sin_port = osmo_ntohs(rtp_info->port);
if (inet_pton(AF_INET, rtp_info->addr, &sin->sin_addr) != 1)
return false;
break;
case AF_INET6:
sin6 = (struct sockaddr_in6 *)dest;
sin6->sin6_family = AF_INET6;
sin6->sin6_port = osmo_ntohs(rtp_info->port);
if (inet_pton(AF_INET6, rtp_info->addr, &sin6->sin6_addr) != 1)
return false;
break;
default:
return false;
}
return true;
}
bool osmo_mgcpc_ep_ci_get_crcx_info_to_osmux_cid(const struct osmo_mgcpc_ep_ci *ci, uint8_t* cid)
{
const struct mgcp_conn_peer *rtp_info;
rtp_info = osmo_mgcpc_ep_ci_get_rtp_info(ci);
if (!rtp_info)
return false;
if (!rtp_info->x_osmo_osmux_use)
return false;
*cid = rtp_info->x_osmo_osmux_cid;
return true;
}
static const struct osmo_tdef_state_timeout osmo_mgcpc_ep_fsm_timeouts[32] = {
[OSMO_MGCPC_EP_ST_WAIT_MGW_RESPONSE] = { .T=-2427 },
};
/* Transition to a state, using the T timer defined in assignment_fsm_timeouts.
* The actual timeout value is in turn obtained from osmo_mgcpc_ep.T_defs.
* Assumes local variable fi exists. */
#define osmo_mgcpc_ep_fsm_state_chg(state) \
osmo_tdef_fsm_inst_state_chg(fi, state, osmo_mgcpc_ep_fsm_timeouts, \
((struct osmo_mgcpc_ep*)fi->priv)->T_defs, 5)
/*! Dispatch an actual CRCX/MDCX/DLCX message for this connection.
*
* If the 'notify' instance deallocates before it received a notification of event_success or event_failure,
* osmo_mgcpc_ep_ci_cancel_notify() or osmo_mgcpc_ep_cancel_notify() must be called. It is not harmful to cancel
* notification after an event has been received.
*
* \param ci Connection identifier as obtained from osmo_mgcpc_ep_ci_add().
* \param verb MGCP operation to dispatch.
* \param verb_info Parameters for the MGCP operation.
* \param notify Peer FSM instance to notify of completed/failed operation.
* \param event_success Which event to dispatch to 'notify' upon OK response.
* \param event_failure Which event to dispatch to 'notify' upon failure response.
* \param notify_data Data pointer to pass to the event dispatch for both success and failure.
*/
void osmo_mgcpc_ep_ci_request(struct osmo_mgcpc_ep_ci *ci,
enum mgcp_verb verb, const struct mgcp_conn_peer *verb_info,
struct osmo_fsm_inst *notify,
uint32_t event_success, uint32_t event_failure,
void *notify_data)
{
struct osmo_mgcpc_ep *ep;
struct osmo_fsm_inst *fi;
struct osmo_mgcpc_ep_ci cleared_ci;
ci = osmo_mgcpc_ep_check_ci(ci);
if (!ci) {
LOGP(DLMGCP, LOGL_ERROR, "Invalid MGW endpoint request: no ci\n");
goto dispatch_error;
}
if (!verb_info && verb != MGCP_VERB_DLCX) {
LOG_CI(ci, LOGL_ERROR, "Invalid MGW endpoint request: missing verb details for %s\n",
osmo_mgcp_verb_name(verb));
goto dispatch_error;
}
if ((verb < 0) || (verb > MGCP_VERB_RSIP)) {
LOG_CI(ci, LOGL_ERROR, "Invalid MGW endpoint request: unknown verb: %s\n",
osmo_mgcp_verb_name(verb));
goto dispatch_error;
}
ep = ci->ep;
fi = ep->fi;
/* Clear volatile state by explicitly keeping those that should remain. Because we can't assign
* the char[] directly, dance through cleared_ci and copy back. */
cleared_ci = (struct osmo_mgcpc_ep_ci){
.ep = ep,
.mgcp_client_fi = ci->mgcp_client_fi,
.got_port_info = ci->got_port_info,
.rtp_info = ci->rtp_info,
.occupied = true,
/* .pending = true follows below */
.verb = verb,
.notify = {
.fi = notify,
.success = event_success,
.failure = event_failure,
.data = notify_data,
}
};
osmo_strlcpy(cleared_ci.label, ci->label, sizeof(cleared_ci.label));
osmo_strlcpy(cleared_ci.mgcp_ci_str, ci->mgcp_ci_str, sizeof(cleared_ci.mgcp_ci_str));
*ci = cleared_ci;
if (verb_info)
ci->verb_info = *verb_info;
LOG_CI_VERB(ci, LOGL_DEBUG, "notify=%s\n", osmo_fsm_inst_name(ci->notify.fi));
if (ep->endpoint[0]) {
if (ci->verb_info.endpoint[0] && strcmp(ci->verb_info.endpoint, ep->endpoint))
LOG_CI(ci, LOGL_ERROR,
"Warning: Requested %s on endpoint %s, but this CI is on endpoint %s."
" Using the proper endpoint instead.\n",
osmo_mgcp_verb_name(verb), ci->verb_info.endpoint, ep->endpoint);
osmo_strlcpy(ci->verb_info.endpoint, ep->endpoint, sizeof(ci->verb_info.endpoint));
}
switch (ci->verb) {
case MGCP_VERB_CRCX:
if (ci->mgcp_client_fi) {
LOG_CI(ci, LOGL_ERROR, "CRCX can be called only once per MGW endpoint CI\n");
on_failure(ci);
return;
}
break;
case MGCP_VERB_MDCX:
if (!ci->mgcp_client_fi) {
LOG_CI_VERB(ci, LOGL_ERROR, "The first verb on an unused MGW endpoint CI must be CRCX, not %s\n",
osmo_mgcp_verb_name(ci->verb));
on_failure(ci);
return;
}
break;
case MGCP_VERB_DLCX:
if (!ci->mgcp_client_fi) {
LOG_CI_VERB(ci, LOGL_DEBUG, "Ignoring DLCX on unused MGW endpoint CI\n");
return;
}
break;
default:
LOG_CI(ci, LOGL_ERROR, "This verb is not supported: %s\n", osmo_mgcp_verb_name(ci->verb));
on_failure(ci);
return;
}
ci->pending = true;
LOG_CI_VERB(ci, LOGL_DEBUG, "Scheduling\n");
if (ep->fi->state != OSMO_MGCPC_EP_ST_WAIT_MGW_RESPONSE)
osmo_mgcpc_ep_fsm_state_chg(OSMO_MGCPC_EP_ST_WAIT_MGW_RESPONSE);
return;
dispatch_error:
if (notify)
osmo_fsm_inst_dispatch(notify, event_failure, notify_data);
}
/*! No longer notify for any state changes for any conns of this endpoint.
* Useful if the notify instance passed to osmo_mgcpc_ep_ci_request() is about to deallocate.
* \param ep The endpoint FSM instance.
* \param notify Which target to cancel notification for, if NULL cancel all notifications. */
void osmo_mgcpc_ep_cancel_notify(struct osmo_mgcpc_ep *ep, struct osmo_fsm_inst *notify)
{
struct fsm_notify *n;
int i;
for (i = 0; i < ARRAY_SIZE(ep->ci); i++) {
struct osmo_mgcpc_ep_ci *ci = &ep->ci[i];
if (!notify || ci->notify.fi == notify)
ci->notify.fi = NULL;
}
llist_for_each_entry(n, &ep->background_notify, entry) {
if (!notify || n->fi == notify)
n->fi = NULL;
}
}
/* Return the osmo_mgcpc_ep that this conn belongs to. */
struct osmo_mgcpc_ep *osmo_mgcpc_ep_ci_ep(struct osmo_mgcpc_ep_ci *conn)
{
if (!conn)
return NULL;
return conn->ep;
}
static int send_verb(struct osmo_mgcpc_ep_ci *ci)
{
int rc;
struct osmo_mgcpc_ep *ep = ci->ep;
struct fsm_notify notify;
if (!ci->occupied || !ci->pending || ci->sent)
return 0;
switch (ci->verb) {
case MGCP_VERB_CRCX:
OSMO_ASSERT(!ci->mgcp_client_fi);
LOG_CI_VERB(ci, LOGL_DEBUG, "Sending\n");
ci->mgcp_client_fi = mgcp_conn_create(ep->mgcp_client, ep->fi,
CI_EV_FAILURE(ci), CI_EV_SUCCESS(ci),
&ci->verb_info);
ci->sent = true;
if (!ci->mgcp_client_fi){
LOG_CI_VERB(ci, LOGL_ERROR, "Cannot send\n");
on_failure(ci);
return -EINVAL;
}
osmo_fsm_inst_update_id(ci->mgcp_client_fi, ci->label);
break;
case MGCP_VERB_MDCX:
OSMO_ASSERT(ci->mgcp_client_fi);
LOG_CI_VERB(ci, LOGL_DEBUG, "Sending\n");
rc = mgcp_conn_modify(ci->mgcp_client_fi, CI_EV_SUCCESS(ci), &ci->verb_info);
ci->sent = true;
if (rc) {
LOG_CI_VERB(ci, LOGL_ERROR, "Cannot send (rc=%d %s)\n", rc, strerror(-rc));
on_failure(ci);
return -EINVAL;
}
break;
case MGCP_VERB_DLCX:
LOG_CI(ci, LOGL_DEBUG, "Sending MGCP: %s %s\n",
osmo_mgcp_verb_name(ci->verb), ci->mgcp_ci_str);
/* The way this is designed, we actually need to forget all about the ci right away. */
mgcp_conn_delete(ci->mgcp_client_fi);
notify = ci->notify;
*ci = (struct osmo_mgcpc_ep_ci){
.ep = ep,
};
/* When dispatching an event for this CI, the user may decide to trigger the next request for this conn
* right away. So we must be ready with a cleared *ci. */
if (notify.fi)
osmo_fsm_inst_dispatch(notify.fi, notify.success, notify.data);
break;
default:
OSMO_ASSERT(false);
}
return 1;
}
/*! DLCX all connections, terminate the endpoint FSM and free. */
void osmo_mgcpc_ep_clear(struct osmo_mgcpc_ep *ep)
{
if (!ep)
return;
osmo_mgcpc_ep_cancel_notify(ep, NULL);
osmo_fsm_inst_term(ep->fi, OSMO_FSM_TERM_REGULAR, 0);
}
static void osmo_mgcpc_ep_count(struct osmo_mgcpc_ep *ep, int *occupied, int *pending_not_sent,
int *waiting_for_response)
{
int i;
if (occupied)
*occupied = 0;
if (pending_not_sent)
*pending_not_sent = 0;
if (waiting_for_response)
*waiting_for_response = 0;
for (i = 0; i < ARRAY_SIZE(ep->ci); i++) {
struct osmo_mgcpc_ep_ci *ci = &ep->ci[i];
if (ci->occupied) {
if (occupied)
(*occupied)++;
} else
continue;
if (ci->pending)
LOG_CI_VERB(ci, LOGL_DEBUG, "%s\n",
ci->sent ? "waiting for response" : "waiting to be sent");
else
LOG_CI_VERB(ci, LOGL_DEBUG, "done (%s)\n", mgcp_conn_peer_name(osmo_mgcpc_ep_ci_get_rtp_info(ci)));
if (ci->pending && ci->sent)
if (waiting_for_response)
(*waiting_for_response)++;
if (ci->pending && !ci->sent)
if (pending_not_sent)
(*pending_not_sent)++;
}
}
static bool osmo_mgcpc_ep_fsm_check_state_chg_after_response(struct osmo_fsm_inst *fi)
{
int waiting_for_response;
int occupied;
struct osmo_mgcpc_ep *ep = osmo_mgcpc_ep_fi_mgwep(fi);
osmo_mgcpc_ep_count(ep, &occupied, NULL, &waiting_for_response);
LOG_MGCPC_EP(ep, LOGL_DEBUG, "CI in use: %d, waiting for response: %d\n", occupied, waiting_for_response);
if (!occupied) {
/* All CI have been released. The endpoint no longer exists. Notify the parent FSM, by
* terminating. */
osmo_fsm_inst_term(fi, OSMO_FSM_TERM_REGULAR, 0);
return false;
}
if (!waiting_for_response) {
if (fi->state != OSMO_MGCPC_EP_ST_IN_USE)
osmo_mgcpc_ep_fsm_state_chg(OSMO_MGCPC_EP_ST_IN_USE);
}
return true;
}
static void osmo_mgcpc_ep_fsm_wait_mgw_response_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
{
static int re_enter = 0;
int rc;
int count = 0;
int i;
struct osmo_mgcpc_ep *ep = osmo_mgcpc_ep_fi_mgwep(fi);
re_enter++;
OSMO_ASSERT(re_enter < 10);
/* The first CRCX gives us the endpoint name in the CRCX response. So we must wait for the first CRCX endpoint
* response to come in before sending any other MGCP requests -- otherwise we might end up creating new
* endpoints instead of acting on the same. This FSM always sends out N requests and waits for all of them to
* complete before sending out new requests. Hence we're safe when the very first time at most one request is
* sent (which needs to be a CRCX). */
for (i = 0; i < ARRAY_SIZE(ep->ci); i++) {
struct osmo_mgcpc_ep_ci *ci = &ep->ci[i];
/* Make sure that only CRCX get dispatched if no CRCX were sent yet. */
if (!ep->first_crcx_complete) {
if (ci->occupied && ci->verb != MGCP_VERB_CRCX)
continue;
}
rc = send_verb(&ep->ci[i]);
/* Need to be careful not to access the instance after failure. Event chains may already have
* deallocated this memory. */
if (rc < 0)
return;
if (!rc)
continue;
count++;
/* Make sure that we wait for the first CRCX response before dispatching more requests. */
if (!ep->first_crcx_complete)
break;
}
LOG_MGCPC_EP(ep, LOGL_DEBUG, "Sent messages: %d\n", count);
if (ep->first_crcx_complete)
osmo_mgcpc_ep_fsm_check_state_chg_after_response(fi);
re_enter--;
}
static void osmo_mgcpc_ep_fsm_handle_ci_events(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct osmo_mgcpc_ep_ci *ci;
struct osmo_mgcpc_ep *ep = osmo_mgcpc_ep_fi_mgwep(fi);
ci = osmo_mgcpc_ep_ci_for_event(ep, event);
if (ci) {
if (event == CI_EV_SUCCESS(ci))
on_success(ci, data);
else
on_failure(ci);
}
}
static void osmo_mgcpc_ep_fsm_in_use_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
{
int pending_not_sent;
struct osmo_mgcpc_ep *ep = osmo_mgcpc_ep_fi_mgwep(fi);
osmo_mgcpc_ep_count(ep, NULL, &pending_not_sent, NULL);
if (pending_not_sent)
osmo_mgcpc_ep_fsm_state_chg(OSMO_MGCPC_EP_ST_WAIT_MGW_RESPONSE);
}
#define S(x) (1 << (x))
static const struct osmo_fsm_state osmo_mgcpc_ep_fsm_states[] = {
[OSMO_MGCPC_EP_ST_UNUSED] = {
.name = "UNUSED",
.in_event_mask = 0,
.out_state_mask = 0
| S(OSMO_MGCPC_EP_ST_WAIT_MGW_RESPONSE)
,
},
[OSMO_MGCPC_EP_ST_WAIT_MGW_RESPONSE] = {
.name = "WAIT_MGW_RESPONSE",
.onenter = osmo_mgcpc_ep_fsm_wait_mgw_response_onenter,
.action = osmo_mgcpc_ep_fsm_handle_ci_events,
.in_event_mask = 0xffffffff,
.out_state_mask = 0
| S(OSMO_MGCPC_EP_ST_IN_USE)
,
},
[OSMO_MGCPC_EP_ST_IN_USE] = {
.name = "IN_USE",
.onenter = osmo_mgcpc_ep_fsm_in_use_onenter,
.action = osmo_mgcpc_ep_fsm_handle_ci_events,
.in_event_mask = 0xffffffff, /* mgcp_client_fsm may send parent term anytime */
.out_state_mask = 0
| S(OSMO_MGCPC_EP_ST_WAIT_MGW_RESPONSE)
,
},
};
static int osmo_mgcpc_ep_fsm_timer_cb(struct osmo_fsm_inst *fi)
{
int i;
struct osmo_mgcpc_ep *ep = osmo_mgcpc_ep_fi_mgwep(fi);
switch (fi->T) {
default:
for (i = 0; i < ARRAY_SIZE(ep->ci); i++) {
struct osmo_mgcpc_ep_ci *ci = &ep->ci[i];
if (!ci->occupied)
continue;
if (!(ci->pending && ci->sent))
continue;
on_failure(ci);
}
return 0;
}
return 0;
}
static void osmo_mgcpc_ep_fsm_pre_term(struct osmo_fsm_inst *fi, enum osmo_fsm_term_cause cause)
{
int i;
struct osmo_mgcpc_ep *ep = osmo_mgcpc_ep_fi_mgwep(fi);
/* We want the mgcp_client_fsm to still stick around until it received the DLCX "OK" responses from the MGW. So
* it should not dealloc along with this ep_fsm instance. Instead, signal DLCX for each conn on the endpoint,
* and detach the mgcp_client_fsm from being a child-fsm.
*
* After mgcp_conn_delete(), an mgcp_client_fsm instance goes into ST_DLCX_RESP, which waits up to 4 seconds for
* a DLCX OK. If none is received in that time, the instance terminates. So cleanup of the instance is
* guaranteed. */
for (i = 0; i < ARRAY_SIZE(ep->ci); i++) {
struct osmo_mgcpc_ep_ci *ci = &ep->ci[i];
if (!ci->occupied || !ci->mgcp_client_fi)
continue;
/* mgcp_conn_delete() unlinks itself from this parent FSM implicitly and waits for the DLCX OK. */
mgcp_conn_delete(ci->mgcp_client_fi);
/* Forget all about this ci */
*ci = (struct osmo_mgcpc_ep_ci){
.ep = ep,
};
}
}
static struct osmo_fsm osmo_mgcpc_ep_fsm = {
.name = "mgw-endp",
.states = osmo_mgcpc_ep_fsm_states,
.num_states = ARRAY_SIZE(osmo_mgcpc_ep_fsm_states),
.log_subsys = DLMGCP,
.event_names = osmo_mgcpc_ep_fsm_event_names,
.timer_cb = osmo_mgcpc_ep_fsm_timer_cb,
.pre_term = osmo_mgcpc_ep_fsm_pre_term,
};
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