From 9c70c883697d63e6f16b0b06b688a6131423c7e1 Mon Sep 17 00:00:00 2001
From: Richard Mudgett <rmudgett@digium.com>
Date: Fri, 11 Aug 2017 16:31:45 -0500
Subject: [PATCH] channel: Fix topology API locking.
* ast_channel_request_stream_topology_change() must not be called with any
channel locks held.
* ast_channel_stream_topology_changed() must be called with only the
passed channel lock held.
ASTERISK-27212
Change-Id: I843de7956d9f1cc7cc02025aea3463d8fe19c691
---
include/asterisk/channel.h | 4 ++--
main/channel.c | 9 ++++++++-
tests/test_stream.c | 4 ++++
3 files changed, 14 insertions(+), 3 deletions(-)
diff --git a/include/asterisk/channel.h b/include/asterisk/channel.h
index f0fe5b212f..3dfbe61d90 100644
--- a/include/asterisk/channel.h
+++ b/include/asterisk/channel.h
@@ -4934,7 +4934,7 @@ int ast_channel_is_multistream(struct ast_channel *chan);
* \param topology The new stream topology
* \param change_source The source that initiated the change
*
- * \pre chan is locked
+ * \note Absolutely _NO_ channel locks should be held before calling this function.
*
* \retval 0 request has been accepted to be attempted
* \retval -1 request could not be attempted
@@ -4956,7 +4956,7 @@ int ast_channel_request_stream_topology_change(struct ast_channel *chan,
* \param chan The channel to provide notice to
* \param topology The new stream topology
*
- * \pre chan is locked
+ * \pre chan is locked Absolutely _NO_ other channels can be locked.
*
* \retval 0 success
* \retval -1 failure
diff --git a/main/channel.c b/main/channel.c
index 632d472478..74de9caac8 100644
--- a/main/channel.c
+++ b/main/channel.c
@@ -10843,22 +10843,29 @@ enum ast_channel_error ast_channel_errno(void)
int ast_channel_request_stream_topology_change(struct ast_channel *chan,
struct ast_stream_topology *topology, void *change_source)
{
+ int res;
+
ast_assert(chan != NULL);
ast_assert(topology != NULL);
+ ast_channel_lock(chan);
if (!ast_channel_is_multistream(chan) || !ast_channel_tech(chan)->indicate) {
+ ast_channel_unlock(chan);
return -1;
}
if (ast_stream_topology_equal(ast_channel_get_stream_topology(chan), topology)) {
ast_debug(3, "Topology of %s already matches what is requested so ignoring topology change request\n",
ast_channel_name(chan));
+ ast_channel_unlock(chan);
return 0;
}
ast_channel_internal_set_stream_topology_change_source(chan, change_source);
- return ast_channel_tech(chan)->indicate(chan, AST_CONTROL_STREAM_TOPOLOGY_REQUEST_CHANGE, topology, sizeof(topology));
+ res = ast_channel_tech(chan)->indicate(chan, AST_CONTROL_STREAM_TOPOLOGY_REQUEST_CHANGE, topology, sizeof(topology));
+ ast_channel_unlock(chan);
+ return res;
}
int ast_channel_stream_topology_changed(struct ast_channel *chan, struct ast_stream_topology *topology)
diff --git a/tests/test_stream.c b/tests/test_stream.c
index 28983e05cc..8c887048cf 100644
--- a/tests/test_stream.c
+++ b/tests/test_stream.c
@@ -1768,7 +1768,9 @@ AST_TEST_DEFINE(stream_topology_change_request_from_application_non_multistream)
ast_test_validate_cleanup(test, change_res == -1, res, done);
ast_test_validate_cleanup(test, !pvt->indicated_change_request, res, done);
+ ast_channel_lock(mock_channel);
change_res = ast_channel_stream_topology_changed(mock_channel, topology);
+ ast_channel_unlock(mock_channel);
ast_test_validate_cleanup(test, change_res == -1, res, done);
ast_test_validate_cleanup(test, !pvt->indicated_changed, res, done);
@@ -1876,7 +1878,9 @@ AST_TEST_DEFINE(stream_topology_change_request_from_application)
ast_test_validate_cleanup(test, !change_res, res, done);
ast_test_validate_cleanup(test, pvt->indicated_change_request, res, done);
+ ast_channel_lock(mock_channel);
change_res = ast_channel_stream_topology_changed(mock_channel, topology);
+ ast_channel_unlock(mock_channel);
ast_test_validate_cleanup(test, !change_res, res, done);
ast_test_validate_cleanup(test, pvt->indicated_changed, res, done);
--
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