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features: Fix crash when transferee hangs up during DTMF attended transfer.

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A crash happens with this sequence of steps:
1) Party A is connected to party B.
2) Party B starts a DTMF attended transfer.
3) Party A hangs up while party B is dialing party C.

When party A hangs up the bridge that party A and party B are in is
dissolved and party B is kicked out of the bridge.  When party B finishes
dialing party C he attempts to move to the new bridge with party C.  Since
party B is no longer in a bridge the attempted move dereferences a NULL
bridge_channel pointer and crashes.

* Made the hold(), unhold(), ringing(), and the bridge_move() functions
tolerant of the channel not being in a bridge.  The assertion that party B
is always in a bridge is not true if the bridged peer of party B hangs up
and dissolves the bridge.  Being tolerant of not being in a bridge allows
the peer hangup stimulus to be processed by the FSM.

* Made the bridge_move() function return void since where the return value
for a failed move was checked generated a FSM coding ERROR message for a
normal off-nominal condition.

* Eliminated most uses of RAII_VAR in bridge_basic.c.

ASTERISK-25003 #close
Reported by: Artem Volodin

Change-Id: Ie2c1b14e5e647d4ea6de300bf56d69805d7bcada
changes/72/372/1
Richard Mudgett 11 years ago
parent 8b0f85ac06
commit be1260a35f
1 changed files with 67 additions and 58 deletions
Show Stats Download Patch File Download Diff File

125
main/bridge_basic.c
Unescape View File

@ -606,18 +606,17 @@ static int setup_dynamic_feature(void *obj, void *arg, void *data, int flags)
*/
static int setup_bridge_features_dynamic(struct ast_bridge_features *features, struct ast_channel *chan)
{
RAII_VAR(struct ao2_container *, applicationmap, NULL, ao2_cleanup);
struct ao2_container *applicationmap;
int res = 0;
ast_channel_lock(chan);
applicationmap = ast_get_chan_applicationmap(chan);
ast_channel_unlock(chan);
if (!applicationmap) {
return 0;
if (applicationmap) {
ao2_callback_data(applicationmap, 0, setup_dynamic_feature, features, &res);
ao2_ref(applicationmap, -1);
}
ao2_callback_data(applicationmap, 0, setup_dynamic_feature, features, &res);
return res;
}
@ -1418,7 +1417,7 @@ static struct attended_transfer_properties *attended_transfer_properties_alloc(
char *tech;
char *addr;
char *serial;
RAII_VAR(struct ast_features_xfer_config *, xfer_cfg, NULL, ao2_cleanup);
struct ast_features_xfer_config *xfer_cfg;
struct ast_flags *transferer_features;
props = ao2_alloc(sizeof(*props), attended_transfer_properties_destructor);
@ -1450,6 +1449,7 @@ static struct attended_transfer_properties *attended_transfer_properties_alloc(
ast_string_field_set(props, context, get_transfer_context(transferer, context));
ast_string_field_set(props, failsound, xfer_cfg->xferfailsound);
ast_string_field_set(props, xfersound, xfer_cfg->xfersound);
ao2_ref(xfer_cfg, -1);
/*
* Save the transferee's party information for any recall calls.
@ -1695,17 +1695,16 @@ static void publish_transfer_fail(struct attended_transfer_properties *props)
*/
static void play_sound(struct ast_channel *chan, const char *sound)
{
RAII_VAR(struct ast_bridge_channel *, bridge_channel, NULL, ao2_cleanup);
struct ast_bridge_channel *bridge_channel;
ast_channel_lock(chan);
bridge_channel = ast_channel_get_bridge_channel(chan);
ast_channel_unlock(chan);
if (!bridge_channel) {
return;
if (bridge_channel) {
ast_bridge_channel_queue_playfile(bridge_channel, NULL, sound, NULL);
ao2_ref(bridge_channel, -1);
}
ast_bridge_channel_queue_playfile(bridge_channel, NULL, sound, NULL);
}
/*!
@ -1713,16 +1712,19 @@ static void play_sound(struct ast_channel *chan, const char *sound)
*/
static void hold(struct ast_channel *chan)
{
RAII_VAR(struct ast_bridge_channel *, bridge_channel, NULL, ao2_cleanup);
struct ast_bridge_channel *bridge_channel;
if (chan) {
ast_channel_lock(chan);
bridge_channel = ast_channel_get_bridge_channel(chan);
ast_channel_unlock(chan);
if (!chan) {
return;
}
ast_assert(bridge_channel != NULL);
ast_channel_lock(chan);
bridge_channel = ast_channel_get_bridge_channel(chan);
ast_channel_unlock(chan);
if (bridge_channel) {
ast_bridge_channel_write_hold(bridge_channel, NULL);
ao2_ref(bridge_channel, -1);
}
}
@ -1731,15 +1733,20 @@ static void hold(struct ast_channel *chan)
*/
static void unhold(struct ast_channel *chan)
{
RAII_VAR(struct ast_bridge_channel *, bridge_channel, NULL, ao2_cleanup);
struct ast_bridge_channel *bridge_channel;
if (!chan) {
return;
}
ast_channel_lock(chan);
bridge_channel = ast_channel_get_bridge_channel(chan);
ast_channel_unlock(chan);
ast_assert(bridge_channel != NULL);
ast_bridge_channel_write_unhold(bridge_channel);
if (bridge_channel) {
ast_bridge_channel_write_unhold(bridge_channel);
ao2_ref(bridge_channel, -1);
}
}
/*!
@ -1747,15 +1754,16 @@ static void unhold(struct ast_channel *chan)
*/
static void ringing(struct ast_channel *chan)
{
RAII_VAR(struct ast_bridge_channel *, bridge_channel, NULL, ao2_cleanup);
struct ast_bridge_channel *bridge_channel;
ast_channel_lock(chan);
bridge_channel = ast_channel_get_bridge_channel(chan);
ast_channel_unlock(chan);
ast_assert(bridge_channel != NULL);
ast_bridge_channel_write_control_data(bridge_channel, AST_CONTROL_RINGING, NULL, 0);
if (bridge_channel) {
ast_bridge_channel_write_control_data(bridge_channel, AST_CONTROL_RINGING, NULL, 0);
ao2_ref(bridge_channel, -1);
}
}
/*!
@ -1800,10 +1808,9 @@ static void bridge_unhold(struct ast_bridge *bridge)
/*!
* \brief Wrapper for \ref bridge_do_move
*/
static int bridge_move(struct ast_bridge *dest, struct ast_bridge *src, struct ast_channel *channel, struct ast_channel *swap)
static void bridge_move(struct ast_bridge *dest, struct ast_bridge *src, struct ast_channel *channel, struct ast_channel *swap)
{
int res;
RAII_VAR(struct ast_bridge_channel *, bridge_channel, NULL, ao2_cleanup);
struct ast_bridge_channel *bridge_channel;
ast_bridge_lock_both(src, dest);
@ -1811,18 +1818,18 @@ static int bridge_move(struct ast_bridge *dest, struct ast_bridge *src, struct a
bridge_channel = ast_channel_get_bridge_channel(channel);
ast_channel_unlock(channel);
ast_assert(bridge_channel != NULL);
ao2_lock(bridge_channel);
bridge_channel->swap = swap;
ao2_unlock(bridge_channel);
if (bridge_channel) {
ao2_lock(bridge_channel);
bridge_channel->swap = swap;
ao2_unlock(bridge_channel);
res = bridge_do_move(dest, bridge_channel, 1, 0);
bridge_do_move(dest, bridge_channel, 1, 0);
}
ast_bridge_unlock(dest);
ast_bridge_unlock(src);
return res;
ao2_cleanup(bridge_channel);
}
/*!
@ -2033,7 +2040,8 @@ static const struct attended_transfer_state_properties state_properties[] = {
static int calling_target_enter(struct attended_transfer_properties *props)
{
return bridge_move(props->target_bridge, props->transferee_bridge, props->transferer, NULL);
bridge_move(props->target_bridge, props->transferee_bridge, props->transferer, NULL);
return 0;
}
static enum attended_transfer_state calling_target_exit(struct attended_transfer_properties *props,
@ -2072,10 +2080,7 @@ static enum attended_transfer_state calling_target_exit(struct attended_transfer
static int hesitant_enter(struct attended_transfer_properties *props)
{
if (bridge_move(props->transferee_bridge, props->target_bridge, props->transferer, NULL)) {
return -1;
}
bridge_move(props->transferee_bridge, props->target_bridge, props->transferer, NULL);
unhold(props->transferer);
return 0;
}
@ -2115,11 +2120,7 @@ static enum attended_transfer_state hesitant_exit(struct attended_transfer_prope
static int rebridge_enter(struct attended_transfer_properties *props)
{
if (bridge_move(props->transferee_bridge, props->target_bridge,
props->transferer, NULL)) {
return -1;
}
bridge_move(props->transferee_bridge, props->target_bridge, props->transferer, NULL);
unhold(props->transferer);
return 0;
}
@ -2840,7 +2841,8 @@ static void transfer_pull(struct ast_bridge *self, struct ast_bridge_channel *br
}
if (self->num_channels == 1) {
RAII_VAR(struct ast_bridge_channel *, transferer_bridge_channel, NULL, ao2_cleanup);
struct ast_bridge_channel *transferer_bridge_channel;
int not_transferer;
ast_channel_lock(props->transferer);
transferer_bridge_channel = ast_channel_get_bridge_channel(props->transferer);
@ -2850,7 +2852,9 @@ static void transfer_pull(struct ast_bridge *self, struct ast_bridge_channel *br
return;
}
if (AST_LIST_FIRST(&self->channels) != transferer_bridge_channel) {
not_transferer = AST_LIST_FIRST(&self->channels) != transferer_bridge_channel;
ao2_ref(transferer_bridge_channel, -1);
if (not_transferer) {
return;
}
}
@ -2887,7 +2891,8 @@ static void recall_pull(struct ast_bridge *self, struct ast_bridge_channel *brid
}
if (self->num_channels == 1) {
RAII_VAR(struct ast_bridge_channel *, target_bridge_channel, NULL, ao2_cleanup);
struct ast_bridge_channel *target_bridge_channel;
if (!props->recall_target) {
/* No recall target means that the pull happened on a transferee. If there's still
* a channel left in the bridge, we don't need to send a stimulus
@ -2899,12 +2904,11 @@ static void recall_pull(struct ast_bridge *self, struct ast_bridge_channel *brid
target_bridge_channel = ast_channel_get_bridge_channel(props->recall_target);
ast_channel_unlock(props->recall_target);
if (!target_bridge_channel) {
return;
}
if (AST_LIST_FIRST(&self->channels) == target_bridge_channel) {
stimulate_attended_transfer(props, STIMULUS_TRANSFEREE_HANGUP);
if (target_bridge_channel) {
if (AST_LIST_FIRST(&self->channels) == target_bridge_channel) {
stimulate_attended_transfer(props, STIMULUS_TRANSFEREE_HANGUP);
}
ao2_ref(target_bridge_channel, -1);
}
}
}
@ -2926,7 +2930,8 @@ static void bridge_personality_atxfer_pull(struct ast_bridge *self, struct ast_b
static enum attended_transfer_stimulus wait_for_stimulus(struct attended_transfer_properties *props)
{
RAII_VAR(struct stimulus_list *, list, NULL, ast_free_ptr);
enum attended_transfer_stimulus stimulus;
struct stimulus_list *list;
SCOPED_MUTEX(lock, ao2_object_get_lockaddr(props));
while (!(list = AST_LIST_REMOVE_HEAD(&props->stimulus_queue, next))) {
@ -2957,7 +2962,9 @@ static enum attended_transfer_stimulus wait_for_stimulus(struct attended_transfe
}
}
}
return list->stimulus;
stimulus = list->stimulus;
ast_free(list);
return stimulus;
}
/*!
@ -3052,7 +3059,7 @@ static int add_transferer_role(struct ast_channel *chan, struct ast_bridge_featu
const char *atxfer_threeway;
const char *atxfer_complete;
const char *atxfer_swap;
RAII_VAR(struct ast_features_xfer_config *, xfer_cfg, NULL, ao2_cleanup);
struct ast_features_xfer_config *xfer_cfg;
SCOPED_CHANNELLOCK(lock, chan);
xfer_cfg = ast_get_chan_features_xfer_config(chan);
@ -3070,6 +3077,7 @@ static int add_transferer_role(struct ast_channel *chan, struct ast_bridge_featu
atxfer_complete = ast_strdupa(xfer_cfg->atxfercomplete);
atxfer_swap = ast_strdupa(xfer_cfg->atxferswap);
}
ao2_ref(xfer_cfg, -1);
return ast_channel_add_bridge_role(chan, AST_TRANSFERER_ROLE_NAME) ||
ast_channel_set_bridge_role_option(chan, AST_TRANSFERER_ROLE_NAME, "abort", atxfer_abort) ||
@ -3090,7 +3098,7 @@ static int grab_transfer(struct ast_channel *chan, char *exten, size_t exten_len
int digit_timeout;
int attempts = 0;
int max_attempts;
RAII_VAR(struct ast_features_xfer_config *, xfer_cfg, NULL, ao2_cleanup);
struct ast_features_xfer_config *xfer_cfg;
char *retry_sound;
char *invalid_sound;
@ -3105,6 +3113,7 @@ static int grab_transfer(struct ast_channel *chan, char *exten, size_t exten_len
max_attempts = xfer_cfg->transferdialattempts;
retry_sound = ast_strdupa(xfer_cfg->transferretrysound);
invalid_sound = ast_strdupa(xfer_cfg->transferinvalidsound);
ao2_ref(xfer_cfg, -1);
ast_channel_unlock(chan);
/* Play the simple "transfer" prompt out and wait */

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