ari/pjsip: Make it possible to control transfers through ARI

Introduce a ChannelTransfer event and the ability to notify progress to
ARI. Implement emitting this event from the PJSIP channel instead of
handling the transfer in Asterisk when configured.

Introduce a dialplan function to the PJSIP channel to switch between the
"core" and "ari-only" behavior.

UserNote: Call transfers on the PJSIP channel can now be controlled by
ARI. This can be enabled by using the PJSIP_TRANSFER_HANDLING(ari-only)
dialplan function.

res/ari/ari_model_validators.h

@@ -571,6 +571,22 @@ int ast_ari_validate_mailbox(struct ast_json *json);
  */
 ari_validator ast_ari_validate_mailbox_fn(void);
 
+/*!
+ * \brief Validator for AdditionalParam.
+ *
+ * Protocol specific additional parameter
+ *
+ * \param json JSON object to validate.
+ * \retval True (non-zero) if valid.
+ * \retval False (zero) if invalid.
+ */
+int ast_ari_validate_additional_param(struct ast_json *json);
+
+/*!
+ * \brief Function pointer to ast_ari_validate_additional_param().
+ */
+ari_validator ast_ari_validate_additional_param_fn(void);
+
 /*!
  * \brief Validator for ApplicationMoveFailed.
  *
@@ -911,6 +927,22 @@ int ast_ari_validate_channel_talking_started(struct ast_json *json);
  */
 ari_validator ast_ari_validate_channel_talking_started_fn(void);
 
+/*!
+ * \brief Validator for ChannelTransfer.
+ *
+ * transfer on a channel.
+ *
+ * \param json JSON object to validate.
+ * \retval True (non-zero) if valid.
+ * \retval False (zero) if invalid.
+ */
+int ast_ari_validate_channel_transfer(struct ast_json *json);
+
+/*!
+ * \brief Function pointer to ast_ari_validate_channel_transfer().
+ */
+ari_validator ast_ari_validate_channel_transfer_fn(void);
+
 /*!
  * \brief Validator for ChannelUnhold.
  *
@@ -1215,6 +1247,54 @@ int ast_ari_validate_recording_started(struct ast_json *json);
  */
 ari_validator ast_ari_validate_recording_started_fn(void);
 
+/*!
+ * \brief Validator for ReferTo.
+ *
+ * transfer destination requested by transferee
+ *
+ * \param json JSON object to validate.
+ * \retval True (non-zero) if valid.
+ * \retval False (zero) if invalid.
+ */
+int ast_ari_validate_refer_to(struct ast_json *json);
+
+/*!
+ * \brief Function pointer to ast_ari_validate_refer_to().
+ */
+ari_validator ast_ari_validate_refer_to_fn(void);
+
+/*!
+ * \brief Validator for ReferredBy.
+ *
+ * transfer destination requested by transferee
+ *
+ * \param json JSON object to validate.
+ * \retval True (non-zero) if valid.
+ * \retval False (zero) if invalid.
+ */
+int ast_ari_validate_referred_by(struct ast_json *json);
+
+/*!
+ * \brief Function pointer to ast_ari_validate_referred_by().
+ */
+ari_validator ast_ari_validate_referred_by_fn(void);
+
+/*!
+ * \brief Validator for RequiredDestination.
+ *
+ * Information about the requested destination
+ *
+ * \param json JSON object to validate.
+ * \retval True (non-zero) if valid.
+ * \retval False (zero) if invalid.
+ */
+int ast_ari_validate_required_destination(struct ast_json *json);
+
+/*!
+ * \brief Function pointer to ast_ari_validate_required_destination().
+ */
+ari_validator ast_ari_validate_required_destination_fn(void);
+
 /*!
  * \brief Validator for StasisEnd.
  *
@@ -1441,6 +1521,9 @@ ari_validator ast_ari_validate_application_fn(void);
  * - name: string (required)
  * - new_messages: int (required)
  * - old_messages: int (required)
+ * AdditionalParam
+ * - parameter_name: string (required)
+ * - parameter_value: string (required)
  * ApplicationMoveFailed
  * - asterisk_id: string
  * - type: string (required)
@@ -1606,6 +1689,14 @@ ari_validator ast_ari_validate_application_fn(void);
  * - application: string (required)
  * - timestamp: Date (required)
  * - channel: Channel (required)
+ * ChannelTransfer
+ * - asterisk_id: string
+ * - type: string (required)
+ * - application: string (required)
+ * - timestamp: Date (required)
+ * - refer_to: ReferTo (required)
+ * - referred_by: ReferredBy (required)
+ * - state: string
  * ChannelUnhold
  * - asterisk_id: string
  * - type: string (required)
@@ -1726,6 +1817,19 @@ ari_validator ast_ari_validate_application_fn(void);
  * - application: string (required)
  * - timestamp: Date (required)
  * - recording: LiveRecording (required)
+ * ReferTo
+ * - bridge: Bridge
+ * - connected_channel: Channel
+ * - destination_channel: Channel
+ * - requested_destination: RequiredDestination (required)
+ * ReferredBy
+ * - bridge: Bridge
+ * - connected_channel: Channel
+ * - source_channel: Channel (required)
+ * RequiredDestination
+ * - additional_protocol_params: List[AdditionalParam]
+ * - destination: string
+ * - protocol_id: string
  * StasisEnd
  * - asterisk_id: string
  * - type: string (required)