Add a non-invasive API for application level manipulation of T38 on a channel. This uses control frames (so they can even pass across IAX2) to negotiate T38 and provided a way of getting the current status of T38 using queryoption. This should by no means cause any issues and if it does I will take responsibility for it.

(closes issue #11873)
Reported by: dimas
Patches:
      v4-t38-api.patch uploaded by dimas (license 88)


git-svn-id: http://svn.digium.com/svn/asterisk/trunk@103799 f38db490-d61c-443f-a65b-d21fe96a405b

1 files changed, 25 insertions, 2 deletions

diff --git a/include/asterisk/channel.h b/include/asterisk/channel.h
index 0faddb870..e5fd5ba81 100644
--- a/include/asterisk/channel.h
+++ b/include/asterisk/channel.h
@@ -389,6 +389,17 @@ enum ast_channel_state {
 	AST_STATE_MUTE = (1 << 16),	/*!< Do not transmit voice data */
 };
 
+/*!
+ * \brief Possible T38 states on channels
+ */
+enum ast_t38_state {
+	T38_STATE_UNAVAILABLE,	/*!< T38 is unavailable on this channel or disabled by configuration */
+	T38_STATE_UNKNOWN,	/*!< The channel supports T38 but the current status is unknown */
+	T38_STATE_NEGOTIATING,	/*!< T38 is being negotiated */
+	T38_STATE_REJECTED,	/*!< Remote side has rejected our offer */
+	T38_STATE_NEGOTIATED,	/*!< T38 established */
+};
+
 /*! \brief Main Channel structure associated with a channel. 
  * This is the side of it mostly used by the pbx and call management.
  *
@@ -1300,10 +1311,10 @@ int ast_best_codec(int fmts);
 
 /*! Checks the value of an option */
 /*! 
- * Query the value of an option, optionally blocking until a reply is received
+ * Query the value of an option
  * Works similarly to setoption except only reads the options.
  */
-struct ast_frame *ast_channel_queryoption(struct ast_channel *channel, int option, void *data, int *datalen, int block);
+int ast_channel_queryoption(struct ast_channel *channel, int option, void *data, int *datalen, int block);
 
 /*! Checks for HTML support on a channel */
 /*! Returns 0 if channel does not support HTML or non-zero if it does */
@@ -1557,6 +1568,18 @@ static inline int ast_select(int nfds, fd_set *rfds, fd_set *wfds, fd_set *efds,
 #endif
 }
 
+/*! \brief Retrieves the current T38 state of a channel */
+static inline enum ast_t38_state ast_channel_get_t38_state(struct ast_channel *chan)
+{
+	enum ast_t38_state state = T38_STATE_UNAVAILABLE;
+	int datalen = sizeof(state);
+
+	ast_channel_queryoption(chan, AST_OPTION_T38_STATE, &state, &datalen, 0);
+
+	return state;
+}
+
+
 #ifdef DO_CRASH
 #define CRASH do { fprintf(stderr, "!! Forcing immediate crash a-la abort !!\n"); *((int *)0) = 0; } while(0)
 #else