Merge Call completion support into trunk.

From Reviewboard:
CCSS stands for Call Completion Supplementary Services. An admittedly out-of-date
overview of the architecture can be found in the file doc/CCSS_architecture.pdf
in the CCSS branch. Off the top of my head, the big differences between what is
implemented and what is in the document are as follows:

1. We did not end up modifying the Hangup application at all.
2. The document states that a single call completion monitor may be used across
   multiple calls to the same device. This proved to not be such a good idea
   when implementing protocol-specific monitors, and so we ended up using one
   monitor per-device per-call.
3. There are some configuration options which were conceived after the document
   was written. These are documented in the ccss.conf.sample that is on this
   review request.
		      
For some basic understanding of terminology used throughout this code, see the
ccss.tex document that is on this review.

This implements CCBS and CCNR in several flavors.

First up is a "generic" implementation, which can work over any channel technology
provided that the channel technology can accurately report device state. Call
completion is requested using the dialplan application CallCompletionRequest and can
be canceled using CallCompletionCancel. Device state subscriptions are used in order
to monitor the state of called parties.

Next, there is a SIP-specific implementation of call completion. This method uses the
methods outlined in draft-ietf-bliss-call-completion-06 to implement call completion
using SIP signaling. There are a few things to note here:

* The agent/monitor terminology used throughout Asterisk sometimes is the reverse of
  what is defined in the referenced draft.

* Implementation of the draft required support for SIP PUBLISH. I attempted to write
  this in a generic-enough fashion such that if someone were to want to write PUBLISH
  support for other event packages, such as dialog-state or presence, most of the effort
  would be in writing callbacks specific to the event package.

* A subportion of supporting PUBLISH reception was that we had to implement a PIDF
  parser. The PIDF support added is a bit minimal. I first wrote a validation
  routine to ensure that the PIDF document is formatted properly. The rest of the
  PIDF reading is done in-line in the call-completion-specific PUBLISH-handling
  code. In other words, while there is PIDF support here, it is not in any state
  where it could easily be applied to other event packages as is.

Finally, there are a variety of ISDN-related call completion protocols supported. These
were written by Richard Mudgett, and as such I can't really say much about their
implementation. There are notes in the CHANGES file that indicate the ISDN protocols
over which call completion is supported.

Review: https://reviewboard.asterisk.org/r/523


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@256528 65c4cc65-6c06-0410-ace0-fbb531ad65f3

1 files changed, 102 insertions, 0 deletions

diff --git a/channels/sig_pri.h b/channels/sig_pri.h
index 0bccd6ab0..7ea92d752 100644
--- a/channels/sig_pri.h
+++ b/channels/sig_pri.h
@@ -27,8 +27,44 @@
 
 #include "asterisk/channel.h"
 #include "asterisk/frame.h"
+#include "asterisk/ccss.h"
 #include <libpri.h>
 #include <dahdi/user.h>
+#if defined(PRI_SUBCMD_CC_AVAILABLE)
+/* BUGBUG the HAVE_PRI_CCSS line is to be removed when the CCSS branch is merged to trunk and the configure script is updated. */
+#define HAVE_PRI_CCSS 1
+#endif	/* defined(PRI_SUBCMD_CC_AVAILABLE) */
+
+#if defined(HAVE_PRI_CCSS)
+/*! PRI debug message flags when normal PRI debugging is turned on at the command line. */
+#define SIG_PRI_DEBUG_NORMAL	\
+	(PRI_DEBUG_APDU | PRI_DEBUG_Q931_DUMP | PRI_DEBUG_Q931_STATE | PRI_DEBUG_Q921_STATE \
+	| PRI_DEBUG_CC)
+
+/*! PRI debug message flags when intense PRI debugging is turned on at the command line. */
+#define SIG_PRI_DEBUG_INTENSE	\
+	(PRI_DEBUG_APDU | PRI_DEBUG_Q931_DUMP | PRI_DEBUG_Q931_STATE | PRI_DEBUG_Q921_STATE \
+	| PRI_DEBUG_CC | PRI_DEBUG_Q921_RAW | PRI_DEBUG_Q921_DUMP)
+
+#else
+
+/*! PRI debug message flags when normal PRI debugging is turned on at the command line. */
+#define SIG_PRI_DEBUG_NORMAL	\
+	(PRI_DEBUG_APDU | PRI_DEBUG_Q931_DUMP | PRI_DEBUG_Q931_STATE | PRI_DEBUG_Q921_STATE)
+
+/*! PRI debug message flags when intense PRI debugging is turned on at the command line. */
+#define SIG_PRI_DEBUG_INTENSE	\
+	(PRI_DEBUG_APDU | PRI_DEBUG_Q931_DUMP | PRI_DEBUG_Q931_STATE | PRI_DEBUG_Q921_STATE \
+	| PRI_DEBUG_Q921_RAW | PRI_DEBUG_Q921_DUMP)
+#endif	/* !defined(HAVE_PRI_CCSS) */
+
+#if 0
+/*! PRI debug message flags set on initial startup. */
+#define SIG_PRI_DEBUG_DEFAULT	SIG_PRI_DEBUG_NORMAL
+#else
+/*! PRI debug message flags set on initial startup. */
+#define SIG_PRI_DEBUG_DEFAULT	0
+#endif
 
 enum sig_pri_tone {
 	SIG_PRI_TONE_RINGTONE = 0,
@@ -78,6 +114,14 @@ struct sig_pri_callback {
 	void (* const set_rdnis)(void *pvt, const char *rdnis);
 	void (* const queue_control)(void *pvt, int subclass);
 	int (* const new_nobch_intf)(struct sig_pri_pri *pri);
+	const char *(* const get_orig_dialstring)(void *pvt);
+	void (* const make_cc_dialstring)(void *pvt, char *buf, size_t buf_size);
+	void (* const update_span_devstate)(struct sig_pri_pri *pri);
+
+	/*! Reference the parent module. */
+	void (*module_ref)(void);
+	/*! Unreference the parent module. */
+	void (*module_unref)(void);
 };
 
 #define NUM_DCHANS		4	/*!< No more than 4 d-channels */
@@ -194,6 +238,7 @@ struct sig_pri_chan {
 
 struct sig_pri_pri {
 	/* Should be set by user */
+	struct ast_cc_config_params *cc_params;			/*!< CC config parameters for each new call. */
 	int	pritimers[PRI_MAX_TIMERS];
 	int overlapdial;								/*!< In overlap dialing mode */
 	int qsigchannelmapping;                     	/*!< QSIG channel mapping type */
@@ -229,6 +274,11 @@ struct sig_pri_pri {
 	int switchtype;							/*!< Type of switch to emulate */
 	int nsf;								/*!< Network-Specific Facilities */
 	int trunkgroup;							/*!< What our trunkgroup is */
+#if defined(HAVE_PRI_CCSS)
+	int cc_ptmp_recall_mode;				/*!< CC PTMP recall mode. globalRecall(0), specificRecall(1) */
+	int cc_qsig_signaling_link_req;			/*!< CC Q.SIG signaling link retention (Party A) release(0), retain(1), do-not-care(2) */
+	int cc_qsig_signaling_link_rsp;			/*!< CC Q.SIG signaling link retention (Party B) release(0), retain(1) */
+#endif	/* defined(HAVE_PRI_CCSS) */
 
 	int dchanavail[NUM_DCHANS];				/*!< Whether each channel is available */
 	int debug;								/*!< set to true if to dump PRI event info (tested but never set) */
@@ -257,6 +307,37 @@ struct sig_pri_pri {
 	ast_mutex_t lock;							/*!< libpri access Mutex */
 	time_t lastreset;							/*!< time when unused channels were last reset */
 	struct sig_pri_callback *calls;
+	/*!
+	 * \brief Congestion device state of the span.
+	 * \details
+	 * AST_DEVICE_NOT_INUSE - Span does not have all B channels in use.
+	 * AST_DEVICE_BUSY - All B channels are in use.
+	 * AST_DEVICE_UNAVAILABLE - Span is in alarm.
+	 * \note
+	 * Device name:  DAHDI/I<span>/congestion
+	 */
+	int congestion_devstate;
+#if defined(THRESHOLD_DEVSTATE_PLACEHOLDER)
+	/*! \todo An ISDN span threshold device state could be useful in determining how often a span utilization goes over a configurable threshold. */
+	/*!
+	 * \brief User threshold device state of the span.
+	 * \details
+	 * AST_DEVICE_NOT_INUSE - There are no B channels in use.
+	 * AST_DEVICE_INUSE - The number of B channels in use is less than
+	 *    the configured threshold but not zero.
+	 * AST_DEVICE_BUSY - The number of B channels in use meets or exceeds
+	 *    the configured threshold.
+	 * AST_DEVICE_UNAVAILABLE - Span is in alarm.
+	 * \note
+	 * Device name:  DAHDI/I<span>/threshold
+	 */
+	int threshold_devstate;
+	/*!
+	 * \brief Number of B channels in use to consider the span in a busy state.
+	 * \note Setting the threshold to zero is interpreted as all B channels.
+	 */
+	int user_busy_threshold;
+#endif	/* defined(THRESHOLD_DEVSTATE_PLACEHOLDER) */
 };
 
 void sig_pri_extract_called_num_subaddr(struct sig_pri_chan *p, const char *rdest, char *called, size_t called_buff_size);
@@ -304,4 +385,25 @@ int pri_maintenance_bservice(struct pri *pri, struct sig_pri_chan *p, int change
 
 void sig_pri_fixup(struct ast_channel *oldchan, struct ast_channel *newchan, struct sig_pri_chan *pchan);
 
+int sig_pri_cc_agent_init(struct ast_cc_agent *agent, struct sig_pri_chan *pvt_chan);
+int sig_pri_cc_agent_start_offer_timer(struct ast_cc_agent *agent);
+int sig_pri_cc_agent_stop_offer_timer(struct ast_cc_agent *agent);
+void sig_pri_cc_agent_req_ack(struct ast_cc_agent *agent);
+int sig_pri_cc_agent_status_req(struct ast_cc_agent *agent);
+int sig_pri_cc_agent_stop_ringing(struct ast_cc_agent *agent);
+int sig_pri_cc_agent_party_b_free(struct ast_cc_agent *agent);
+int sig_pri_cc_agent_start_monitoring(struct ast_cc_agent *agent);
+int sig_pri_cc_agent_callee_available(struct ast_cc_agent *agent);
+void sig_pri_cc_agent_destructor(struct ast_cc_agent *agent);
+
+int sig_pri_cc_monitor_req_cc(struct ast_cc_monitor *monitor, int *available_timer_id);
+int sig_pri_cc_monitor_suspend(struct ast_cc_monitor *monitor);
+int sig_pri_cc_monitor_unsuspend(struct ast_cc_monitor *monitor);
+int sig_pri_cc_monitor_status_rsp(struct ast_cc_monitor *monitor, enum ast_device_state devstate);
+int sig_pri_cc_monitor_cancel_available_timer(struct ast_cc_monitor *monitor, int *sched_id);
+void sig_pri_cc_monitor_destructor(void *monitor_pvt);
+
+int sig_pri_load(const char *cc_type_name);
+void sig_pri_unload(void);
+
 #endif /* _SIG_PRI_H */