/*! \brief Called when a frame should be written out to a channel */
static int bridge_write(struct ast_channel *ast, struct ast_frame *f)
{
struct bridge_pvt *p = ast->tech_pvt;
struct ast_channel *other;
ast_mutex_lock(&p->lock);
other = (p->input == ast ? p->output : p->input);
while (other && ast_channel_trylock(other)) {
ast_mutex_unlock(&p->lock);
do {
CHANNEL_DEADLOCK_AVOIDANCE(ast);
} while (ast_mutex_trylock(&p->lock));
other = (p->input == ast ? p->output : p->input);
}
/* We basically queue the frame up on the other channel if present */
if (other) {
ast_queue_frame(other, f);
ast_channel_unlock(other);
}
ast_mutex_unlock(&p->lock);
return 0;
}
static struct chanspy_ds *chanspy_ds_free(struct chanspy_ds *chanspy_ds)
{
struct ast_channel *chan;
if (!chanspy_ds) {
return NULL;
}
ast_mutex_lock(&chanspy_ds->lock);
while ((chan = chanspy_ds->chan)) {
struct ast_datastore *datastore;
if (ast_channel_trylock(chan)) {
DEADLOCK_AVOIDANCE(&chanspy_ds->lock);
continue;
}
if ((datastore = ast_channel_datastore_find(chan, &chanspy_ds_info, chanspy_ds->unique_id))) {
ast_channel_datastore_remove(chan, datastore);
/* chanspy_ds->chan is NULL after this call */
chanspy_ds_destroy(datastore->data);
datastore->data = NULL;
ast_channel_datastore_free(datastore);
}
ast_channel_unlock(chan);
break;
}
ast_mutex_unlock(&chanspy_ds->lock);
return NULL;
}
/*! \brief Helper function to not deadlock when queueing the hangup frame */
static void bridge_queue_hangup(struct bridge_pvt *p, struct ast_channel *us)
{
struct ast_channel *other = (p->input == us ? p->output : p->input);
while (other && ast_channel_trylock(other)) {
ast_mutex_unlock(&p->lock);
do {
CHANNEL_DEADLOCK_AVOIDANCE(us);
} while (ast_mutex_trylock(&p->lock));
other = (p->input == us ? p->output : p->input);
}
/* We basically queue the frame up on the other channel if present */
if (other) {
ast_queue_hangup(other);
ast_channel_unlock(other);
}
return;
}
static int find_channel_by_group(void *obj, void *arg, void *data, int flags)
{
struct ast_channel *target = obj; /*!< Potential pickup target */
struct ast_channel *chan = arg; /*!< Channel wanting to pickup call */
if (chan == target) {
return 0;
}
ast_channel_lock(target);
if (ast_can_pickup(target)) {
/* Lock both channels. */
while (ast_channel_trylock(chan)) {
ast_channel_unlock(target);
sched_yield();
ast_channel_lock(target);
}
/*
* Both callgroup and namedcallgroup pickup variants are
* matched independently. Checking for named group match is
* done last since it's a more expensive operation.
*/
if ((ast_channel_pickupgroup(chan) & ast_channel_callgroup(target))
|| (ast_namedgroups_intersect(ast_channel_named_pickupgroups(chan),
ast_channel_named_callgroups(target)))) {
struct ao2_container *candidates = data;/*!< Candidate channels found. */
/* This is a candidate to pickup */
ao2_link(candidates, target);
}
ast_channel_unlock(chan);
}
ast_channel_unlock(target);
return 0;
}
/*!
* \internal
* \note This function assumes that we're only called from the "outbound" local channel side
*
* \note it is assummed p is locked and reffed before entering this function
*/
static void check_bridge(struct ast_channel *ast, struct local_pvt *p)
{
struct ast_channel *owner;
struct ast_channel *chan;
struct ast_channel *bridged_chan;
struct ast_frame *f;
/* Do a few conditional checks early on just to see if this optimization is possible */
if (ast_test_flag(p, LOCAL_NO_OPTIMIZATION | LOCAL_ALREADY_MASQED)
|| !p->chan || !p->owner) {
return;
}
/* Safely get the channel bridged to p->chan */
chan = ast_channel_ref(p->chan);
ao2_unlock(p); /* don't call bridged channel with the pvt locked */
bridged_chan = ast_bridged_channel(chan);
ao2_lock(p);
chan = ast_channel_unref(chan);
/* since we had to unlock p to get the bridged chan, validate our
* data once again and verify the bridged channel is what we expect
* it to be in order to perform this optimization */
if (ast_test_flag(p, LOCAL_NO_OPTIMIZATION | LOCAL_ALREADY_MASQED)
|| !p->chan || !p->owner
|| (ast_channel_internal_bridged_channel(p->chan) != bridged_chan)) {
return;
}
/* only do the masquerade if we are being called on the outbound channel,
if it has been bridged to another channel and if there are no pending
frames on the owner channel (because they would be transferred to the
outbound channel during the masquerade)
*/
if (!ast_channel_internal_bridged_channel(p->chan) /* Not ast_bridged_channel! Only go one step! */
|| !AST_LIST_EMPTY(ast_channel_readq(p->owner))
|| ast != p->chan /* Sanity check (should always be false) */) {
return;
}
/* Masquerade bridged channel into owner */
/* Lock everything we need, one by one, and give up if
we can't get everything. Remember, we'll get another
chance in just a little bit */
if (ast_channel_trylock(ast_channel_internal_bridged_channel(p->chan))) {
return;
}
if (ast_check_hangup(ast_channel_internal_bridged_channel(p->chan))
|| ast_channel_trylock(p->owner)) {
ast_channel_unlock(ast_channel_internal_bridged_channel(p->chan));
return;
}
/*
* At this point we have 4 locks:
* p, p->chan (same as ast), p->chan->_bridge, p->owner
*
* Flush a voice or video frame on the outbound channel to make
* the queue empty faster so we can get optimized out.
*/
f = AST_LIST_FIRST(ast_channel_readq(p->chan));
if (f && (f->frametype == AST_FRAME_VOICE || f->frametype == AST_FRAME_VIDEO)) {
AST_LIST_REMOVE_HEAD(ast_channel_readq(p->chan), frame_list);
ast_frfree(f);
f = AST_LIST_FIRST(ast_channel_readq(p->chan));
}
if (f
|| ast_check_hangup(p->owner)
|| ast_channel_masquerade(p->owner, ast_channel_internal_bridged_channel(p->chan))) {
ast_channel_unlock(p->owner);
ast_channel_unlock(ast_channel_internal_bridged_channel(p->chan));
return;
}
/* Masquerade got setup. */
ast_debug(4, "Masquerading %s <- %s\n",
ast_channel_name(p->owner),
ast_channel_name(ast_channel_internal_bridged_channel(p->chan)));
if (ast_channel_monitor(p->owner)
&& !ast_channel_monitor(ast_channel_internal_bridged_channel(p->chan))) {
struct ast_channel_monitor *tmp;
/* If a local channel is being monitored, we don't want a masquerade
* to cause the monitor to go away. Since the masquerade swaps the monitors,
* pre-swapping the monitors before the masquerade will ensure that the monitor
* ends up where it is expected.
*/
tmp = ast_channel_monitor(p->owner);
ast_channel_monitor_set(p->owner, ast_channel_monitor(ast_channel_internal_bridged_channel(p->chan)));
ast_channel_monitor_set(ast_channel_internal_bridged_channel(p->chan), tmp);
}
if (ast_channel_audiohooks(p->chan)) {
struct ast_audiohook_list *audiohooks_swapper;
audiohooks_swapper = ast_channel_audiohooks(p->chan);
ast_channel_audiohooks_set(p->chan, ast_channel_audiohooks(p->owner));
ast_channel_audiohooks_set(p->owner, audiohooks_swapper);
}
/* If any Caller ID was set, preserve it after masquerade like above. We must check
* to see if Caller ID was set because otherwise we'll mistakingly copy info not
* set from the dialplan and will overwrite the real channel Caller ID. The reason
* for this whole preswapping action is because the Caller ID is set on the channel
* thread (which is the to be masqueraded away local channel) before both local
* channels are optimized away.
*/
if (ast_channel_caller(p->owner)->id.name.valid || ast_channel_caller(p->owner)->id.number.valid
|| ast_channel_caller(p->owner)->id.subaddress.valid || ast_channel_caller(p->owner)->ani.name.valid
|| ast_channel_caller(p->owner)->ani.number.valid || ast_channel_caller(p->owner)->ani.subaddress.valid) {
SWAP(*ast_channel_caller(p->owner), *ast_channel_caller(ast_channel_internal_bridged_channel(p->chan)));
}
if (ast_channel_redirecting(p->owner)->from.name.valid || ast_channel_redirecting(p->owner)->from.number.valid
|| ast_channel_redirecting(p->owner)->from.subaddress.valid || ast_channel_redirecting(p->owner)->to.name.valid
|| ast_channel_redirecting(p->owner)->to.number.valid || ast_channel_redirecting(p->owner)->to.subaddress.valid) {
SWAP(*ast_channel_redirecting(p->owner), *ast_channel_redirecting(ast_channel_internal_bridged_channel(p->chan)));
}
if (ast_channel_dialed(p->owner)->number.str || ast_channel_dialed(p->owner)->subaddress.valid) {
SWAP(*ast_channel_dialed(p->owner), *ast_channel_dialed(ast_channel_internal_bridged_channel(p->chan)));
}
ast_app_group_update(p->chan, p->owner);
ast_set_flag(p, LOCAL_ALREADY_MASQED);
ast_channel_unlock(p->owner);
ast_channel_unlock(ast_channel_internal_bridged_channel(p->chan));
/* Do the masquerade now. */
owner = ast_channel_ref(p->owner);
ao2_unlock(p);
ast_channel_unlock(ast);
ast_do_masquerade(owner);
ast_channel_unref(owner);
ast_channel_lock(ast);
ao2_lock(p);
}
static int channel_spy(struct ast_channel *chan, struct chanspy_ds *spyee_chanspy_ds,
int *volfactor, int fd, const struct ast_flags *flags)
{
struct chanspy_translation_helper csth;
int running = 0, res, x = 0;
char inp[24] = {0};
char *name;
struct ast_frame *f;
struct ast_silence_generator *silgen = NULL;
struct ast_channel *spyee = NULL;
const char *spyer_name;
ast_channel_lock(chan);
spyer_name = ast_strdupa(chan->name);
ast_channel_unlock(chan);
ast_mutex_lock(&spyee_chanspy_ds->lock);
while ((spyee = spyee_chanspy_ds->chan) && ast_channel_trylock(spyee)) {
/* avoid a deadlock here, just in case spyee is masqueraded and
* chanspy_ds_chan_fixup() is called with the channel locked */
DEADLOCK_AVOIDANCE(&spyee_chanspy_ds->lock);
}
ast_mutex_unlock(&spyee_chanspy_ds->lock);
if (!spyee)
return 0;
/* We now hold the channel lock on spyee */
if (ast_check_hangup(chan) || ast_check_hangup(spyee)) {
ast_channel_unlock(spyee);
return 0;
}
name = ast_strdupa(spyee->name);
if (option_verbose >= 2)
ast_verbose(VERBOSE_PREFIX_2 "Spying on channel %s\n", name);
memset(&csth, 0, sizeof(csth));
ast_audiohook_init(&csth.spy_audiohook, AST_AUDIOHOOK_TYPE_SPY, "ChanSpy");
if (start_spying(spyee, spyer_name, &csth.spy_audiohook)) {
ast_audiohook_destroy(&csth.spy_audiohook);
ast_channel_unlock(spyee);
return 0;
}
if (ast_test_flag(flags, OPTION_WHISPER)) {
ast_audiohook_init(&csth.whisper_audiohook, AST_AUDIOHOOK_TYPE_WHISPER, "ChanSpy");
start_spying(spyee, spyer_name, &csth.whisper_audiohook);
}
ast_channel_unlock(spyee);
spyee = NULL;
csth.volfactor = *volfactor;
if (csth.volfactor) {
csth.spy_audiohook.options.read_volume = csth.volfactor;
csth.spy_audiohook.options.write_volume = csth.volfactor;
}
csth.fd = fd;
if (ast_test_flag(flags, OPTION_PRIVATE))
silgen = ast_channel_start_silence_generator(chan);
else
ast_activate_generator(chan, &spygen, &csth);
/* We can no longer rely on 'spyee' being an actual channel;
it can be hung up and freed out from under us. However, the
channel destructor will put NULL into our csth.spy.chan
field when that happens, so that is our signal that the spyee
channel has gone away.
*/
/* Note: it is very important that the ast_waitfor() be the first
condition in this expression, so that if we wait for some period
of time before receiving a frame from our spying channel, we check
for hangup on the spied-on channel _after_ knowing that a frame
has arrived, since the spied-on channel could have gone away while
we were waiting
*/
while ((res = ast_waitfor(chan, -1) > -1) && csth.spy_audiohook.status == AST_AUDIOHOOK_STATUS_RUNNING) {
if (!(f = ast_read(chan)) || ast_check_hangup(chan)) {
running = -1;
break;
}
if (ast_test_flag(flags, OPTION_WHISPER) && (f->frametype == AST_FRAME_VOICE)) {
ast_audiohook_lock(&csth.whisper_audiohook);
ast_audiohook_write_frame(&csth.whisper_audiohook, AST_AUDIOHOOK_DIRECTION_WRITE, f);
ast_audiohook_unlock(&csth.whisper_audiohook);
ast_frfree(f);
continue;
}
res = (f->frametype == AST_FRAME_DTMF) ? f->subclass : 0;
ast_frfree(f);
if (!res)
continue;
if (x == sizeof(inp))
x = 0;
if (res < 0) {
running = -1;
break;
}
if (res == '*') {
running = 0;
break;
} else if (res == '#') {
if (!ast_strlen_zero(inp)) {
running = atoi(inp);
break;
}
(*volfactor)++;
if (*volfactor > 4)
*volfactor = -4;
if (option_verbose > 2)
ast_verbose(VERBOSE_PREFIX_3 "Setting spy volume on %s to %d\n", chan->name, *volfactor);
csth.volfactor = *volfactor;
csth.spy_audiohook.options.read_volume = csth.volfactor;
csth.spy_audiohook.options.write_volume = csth.volfactor;
} else if (res >= '0' && res <= '9') {
inp[x++] = res;
}
}
if (ast_test_flag(flags, OPTION_PRIVATE))
ast_channel_stop_silence_generator(chan, silgen);
else
ast_deactivate_generator(chan);
if (ast_test_flag(flags, OPTION_WHISPER)) {
ast_audiohook_lock(&csth.whisper_audiohook);
ast_audiohook_detach(&csth.whisper_audiohook);
ast_audiohook_unlock(&csth.whisper_audiohook);
ast_audiohook_destroy(&csth.whisper_audiohook);
}
ast_audiohook_lock(&csth.spy_audiohook);
ast_audiohook_detach(&csth.spy_audiohook);
ast_audiohook_unlock(&csth.spy_audiohook);
ast_audiohook_destroy(&csth.spy_audiohook);
if (option_verbose >= 2)
ast_verbose(VERBOSE_PREFIX_2 "Done Spying on channel %s\n", name);
return running;
}
