Merged revisions 254450 via svnmerge from

https://origsvn.digium.com/svn/asterisk/trunk

........
  r254450 | kpfleming | 2010-03-25 10:27:31 -0500 (Thu, 25 Mar 2010) | 49 lines
  
  Improve handling of T.38 re-INVITEs that arrive before a T.38-capable
  application is executing on a channel.
  
  This patch addresses an issue found during working with end-users
  using res_fax. If an incoming call is answered in the dialplan, or
  jumps to the 'fax' extension due to reception of a CNG tone (with
  faxdetect enabled), and then the remote endpoint sends a T.38
  re-INVITE, it is possible for the channel's T.38 state to be
  'T38_STATE_NEGOTIATING' when the application starts up. Unfortunately,
  even if the application wants to use T.38, it can't respond to the
  peer's negotiation request, because the AST_CONTROL_T38_PARAMETERS
  control frame that chan_sip sent originally has been lost, and the
  application needs the content of that frame to be able to formulate a
  reply.
  
  This patch adds a new 'request' type to AST_CONTROL_T38_PARAMETERS,
  AST_T38_REQUEST_PARMS. If the application sends this request, chan_sip
  will re-send the original control frame (with
  AST_T38_REQUEST_NEGOTIATE as the request type), and the application
  can respond as normal. If this occurs within the five second timeout
  in chan_sip, the automatic cancellation of the peer reinvite will be
  stopped, and the application will 'own' the negotiation process from
  that point onwards.
  
  This also improves the code path in chan_sip to allow sip_indicate(),
  when called for AST_CONTROL_T38_PARAMETERS, to be able to return a
  non-zero response, which should have been in place before since the
  control frame *can* fail to be processed properly. It also modifies
  ast_indicate() to return whatever result the channel driver returned
  for this control frame, rather than converting all non-zero results
  into '-1'. Finally, the new request type intentionally returns a
  positive value, so that an application that sends
  AST_T38_REQUEST_PARMS can know for certain whether the channel driver
  accepted it and will be replying with a control frame of its own, or
  whether it was ignored (if the sip_indicate()/ast_indicate() path had
  properly supported failure responses before, this would not be
  necessary).
  
  This patch also modifies res_fax to take advantage of the new request.
  
  In addition, this patch makes sip_t38_abort() actually lock the
  private structure before doing its work... bad programmer, no donut.
  
  This patch also enhances chan_sip's 'faxdetect' support to allow
  triggering on T.38 re-INVITEs received as well as CNG tone detection.
  
  Review: https://reviewboard.asterisk.org/r/556/
........


git-svn-id: http://svn.digium.com/svn/asterisk/branches/1.6.2@260884 f38db490-d61c-443f-a65b-d21fe96a405b

1 files changed, 4 insertions, 3 deletions

diff --git a/main/channel.c b/main/channel.c
index 974420a79..4d1efab6e 100644
--- a/main/channel.c
+++ b/main/channel.c
@@ -3204,9 +3204,10 @@ int ast_indicate_data(struct ast_channel *chan, int _condition,
 		 * control frames, so we need to return failure, but there
 		 * is also no value in the log message below being emitted
 		 * since failure to handle these frames is not an 'error'
-		 * so just return right now.
-		 */
-		return -1;
+		 * so just return right now. in addition, we want to return
+		 * whatever value the channel driver returned, in case it
+		 * has some meaning.*/
+		return res;
 	case AST_CONTROL_RINGING:
 		ts = ast_get_indication_tone(chan->zone, "ring");
 		/* It is common practice for channel drivers to return -1 if trying