asterisk: Audit locking of channel when manipulating flags.

When manipulating flags on a channel the channel has to be
locked to guarantee that nothing else is also manipulating
the flags. This change introduces locking where necessary to
guarantee this. It also adds helper functions that manipulate
channel flags and lock to reduce repeated code.

ASTERISK-26789

Change-Id: I489280662dba0f4c50981bfc5b5a7073fef2db10

1 files changed, 27 insertions, 10 deletions

diff --git a/main/channel.c b/main/channel.c
index 099e6f65a..1f97e651c 100644
--- a/main/channel.c
+++ b/main/channel.c
@@ -1288,8 +1288,10 @@ int ast_channel_defer_dtmf(struct ast_channel *chan)
 	int pre = 0;
 
 	if (chan) {
+		ast_channel_lock(chan);
 		pre = ast_test_flag(ast_channel_flags(chan), AST_FLAG_DEFER_DTMF);
 		ast_set_flag(ast_channel_flags(chan), AST_FLAG_DEFER_DTMF);
+		ast_channel_unlock(chan);
 	}
 	return pre;
 }
@@ -1297,8 +1299,9 @@ int ast_channel_defer_dtmf(struct ast_channel *chan)
 /*! \brief Unset defer DTMF flag on channel */
 void ast_channel_undefer_dtmf(struct ast_channel *chan)
 {
-	if (chan)
-		ast_clear_flag(ast_channel_flags(chan), AST_FLAG_DEFER_DTMF);
+	if (chan) {
+		ast_channel_clear_flag(chan, AST_FLAG_DEFER_DTMF);
+	}
 }
 
 struct ast_channel *ast_channel_callback(ao2_callback_data_fn *cb_fn, void *arg,
@@ -3223,7 +3226,7 @@ int ast_waitfordigit_full(struct ast_channel *c, int timeout_ms, int audiofd, in
 		return -1;
 
 	/* Only look for the end of DTMF, don't bother with the beginning and don't emulate things */
-	ast_set_flag(ast_channel_flags(c), AST_FLAG_END_DTMF_ONLY);
+	ast_channel_set_flag(c, AST_FLAG_END_DTMF_ONLY);
 
 	/* Wait for a digit, no more than timeout_ms milliseconds total.
 	 * Or, wait indefinitely if timeout_ms is <0.
@@ -3242,12 +3245,12 @@ int ast_waitfordigit_full(struct ast_channel *c, int timeout_ms, int audiofd, in
 			if (errno == 0 || errno == EINTR)
 				continue;
 			ast_log(LOG_WARNING, "Wait failed (%s)\n", strerror(errno));
-			ast_clear_flag(ast_channel_flags(c), AST_FLAG_END_DTMF_ONLY);
+			ast_channel_clear_flag(c, AST_FLAG_END_DTMF_ONLY);
 			return -1;
 		} else if (outfd > -1) {
 			/* The FD we were watching has something waiting */
 			ast_log(LOG_WARNING, "The FD we were waiting for has something waiting. Waitfordigit returning numeric 1\n");
-			ast_clear_flag(ast_channel_flags(c), AST_FLAG_END_DTMF_ONLY);
+			ast_channel_clear_flag(c, AST_FLAG_END_DTMF_ONLY);
 			return 1;
 		} else if (rchan) {
 			int res;
@@ -3261,13 +3264,13 @@ int ast_waitfordigit_full(struct ast_channel *c, int timeout_ms, int audiofd, in
 			case AST_FRAME_DTMF_END:
 				res = f->subclass.integer;
 				ast_frfree(f);
-				ast_clear_flag(ast_channel_flags(c), AST_FLAG_END_DTMF_ONLY);
+				ast_channel_clear_flag(c, AST_FLAG_END_DTMF_ONLY);
 				return res;
 			case AST_FRAME_CONTROL:
 				switch (f->subclass.integer) {
 				case AST_CONTROL_HANGUP:
 					ast_frfree(f);
-					ast_clear_flag(ast_channel_flags(c), AST_FLAG_END_DTMF_ONLY);
+					ast_channel_clear_flag(c, AST_FLAG_END_DTMF_ONLY);
 					return -1;
 				case AST_CONTROL_STREAM_STOP:
 				case AST_CONTROL_STREAM_SUSPEND:
@@ -3278,7 +3281,7 @@ int ast_waitfordigit_full(struct ast_channel *c, int timeout_ms, int audiofd, in
 					 * that perform stream control will handle this. */
 					res = f->subclass.integer;
 					ast_frfree(f);
-					ast_clear_flag(ast_channel_flags(c), AST_FLAG_END_DTMF_ONLY);
+					ast_channel_clear_flag(c, AST_FLAG_END_DTMF_ONLY);
 					return res;
 				case AST_CONTROL_PVT_CAUSE_CODE:
 				case AST_CONTROL_RINGING:
@@ -3313,7 +3316,7 @@ int ast_waitfordigit_full(struct ast_channel *c, int timeout_ms, int audiofd, in
 		}
 	}
 
-	ast_clear_flag(ast_channel_flags(c), AST_FLAG_END_DTMF_ONLY);
+	ast_channel_clear_flag(c, AST_FLAG_END_DTMF_ONLY);
 
 	return 0; /* Time is up */
 }
@@ -5709,9 +5712,9 @@ struct ast_channel *ast_call_forward(struct ast_channel *caller, struct ast_chan
 	} else if (caller) { /* no outgoing helper so use caller if available */
 		call_forward_inherit(new_chan, caller, orig);
 	}
-	ast_set_flag(ast_channel_flags(new_chan), AST_FLAG_ORIGINATED);
 
 	ast_channel_lock_both(orig, new_chan);
+	ast_channel_set_flag(new_chan, AST_FLAG_ORIGINATED);
 	pbx_builtin_setvar_helper(new_chan, "FORWARDERNAME", forwarder);
 	ast_party_connected_line_copy(ast_channel_connected(new_chan), ast_channel_connected(orig));
 	ast_party_redirecting_copy(ast_channel_redirecting(new_chan), ast_channel_redirecting(orig));
@@ -10947,3 +10950,17 @@ int ast_channel_stream_topology_changed(struct ast_channel *chan, struct ast_str
 
 	return ast_channel_tech(chan)->indicate(chan, AST_CONTROL_STREAM_TOPOLOGY_CHANGED, topology, sizeof(topology));
 }
+
+void ast_channel_set_flag(struct ast_channel *chan, unsigned int flag)
+{
+	ast_channel_lock(chan);
+	ast_set_flag(ast_channel_flags(chan), flag);
+	ast_channel_unlock(chan);
+}
+
+void ast_channel_clear_flag(struct ast_channel *chan, unsigned int flag)
+{
+	ast_channel_lock(chan);
+	ast_clear_flag(ast_channel_flags(chan), flag);
+	ast_channel_unlock(chan);
+}