sig_ss7.c

Go to the documentation of this file.

/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2010 Digium, Inc.
 *
 * Richard Mudgett <[email protected]>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*!
 * \file
 * \brief SS7 signaling module.
 *
 * \author Matthew Fredrickson <[email protected]>
 * \author Richard Mudgett <[email protected]>
 *
 * See Also:
 * \arg \ref AstCREDITS
 */

/*** MODULEINFO
   <support_level>core</support_level>
 ***/

#include "asterisk.h"

#if defined(HAVE_SS7)

#include <signal.h>

#include "asterisk/pbx.h"
#include "asterisk/causes.h"
#include "asterisk/musiconhold.h"
#include "asterisk/cli.h"
#include "asterisk/callerid.h"
#include "asterisk/transcap.h"
#include "asterisk/stasis_channels.h"

#include "sig_ss7.h"
#if !defined(LIBSS7_ABI_COMPATIBILITY)
#error "Upgrade your libss7"
#elif LIBSS7_ABI_COMPATIBILITY != 2
#error "Your installed libss7 is not compatible"
#endif

/* ------------------------------------------------------------------- */

static const char *sig_ss7_call_level2str(enum sig_ss7_call_level level)
{
   switch (level) {
   case SIG_SS7_CALL_LEVEL_IDLE:
      return "Idle";
   case SIG_SS7_CALL_LEVEL_ALLOCATED:
      return "Allocated";
   case SIG_SS7_CALL_LEVEL_CONTINUITY:
      return "Continuity";
   case SIG_SS7_CALL_LEVEL_SETUP:
      return "Setup";
   case SIG_SS7_CALL_LEVEL_PROCEEDING:
      return "Proceeding";
   case SIG_SS7_CALL_LEVEL_ALERTING:
      return "Alerting";
   case SIG_SS7_CALL_LEVEL_CONNECT:
      return "Connect";
   }
   return "Unknown";
}

static void sig_ss7_unlock_private(struct sig_ss7_chan *p)
{
   if (sig_ss7_callbacks.unlock_private) {
      sig_ss7_callbacks.unlock_private(p->chan_pvt);
   }
}

static void sig_ss7_lock_private(struct sig_ss7_chan *p)
{
   if (sig_ss7_callbacks.lock_private) {
      sig_ss7_callbacks.lock_private(p->chan_pvt);
   }
}

static void sig_ss7_deadlock_avoidance_private(struct sig_ss7_chan *p)
{
   if (sig_ss7_callbacks.deadlock_avoidance_private) {
      sig_ss7_callbacks.deadlock_avoidance_private(p->chan_pvt);
   } else {
      /* Fallback to the old way if callback not present. */
      sig_ss7_unlock_private(p);
      sched_yield();
      sig_ss7_lock_private(p);
   }
}

void sig_ss7_set_alarm(struct sig_ss7_chan *p, int in_alarm)
{
   p->inalarm = in_alarm;
   if (sig_ss7_callbacks.set_alarm) {
      sig_ss7_callbacks.set_alarm(p->chan_pvt, in_alarm);
   }
}

static void sig_ss7_set_dialing(struct sig_ss7_chan *p, int is_dialing)
{
   if (sig_ss7_callbacks.set_dialing) {
      sig_ss7_callbacks.set_dialing(p->chan_pvt, is_dialing);
   }
}

static void sig_ss7_set_digital(struct sig_ss7_chan *p, int is_digital)
{
   if (sig_ss7_callbacks.set_digital) {
      sig_ss7_callbacks.set_digital(p->chan_pvt, is_digital);
   }
}

static void sig_ss7_set_outgoing(struct sig_ss7_chan *p, int is_outgoing)
{
   p->outgoing = is_outgoing;
   if (sig_ss7_callbacks.set_outgoing) {
      sig_ss7_callbacks.set_outgoing(p->chan_pvt, is_outgoing);
   }
}

static void sig_ss7_set_inservice(struct sig_ss7_chan *p, int is_inservice)
{
   p->inservice = is_inservice;
   if (sig_ss7_callbacks.set_inservice) {
      sig_ss7_callbacks.set_inservice(p->chan_pvt, is_inservice);
   }
}

static void sig_ss7_set_locallyblocked(struct sig_ss7_chan *p, int is_blocked, int type)
{
   if (is_blocked) {
      p->locallyblocked |= type;
   } else {
      p->locallyblocked &= ~type;
   }

   if (sig_ss7_callbacks.set_locallyblocked) {
      sig_ss7_callbacks.set_locallyblocked(p->chan_pvt, p->locallyblocked);
   }
}

static void sig_ss7_set_remotelyblocked(struct sig_ss7_chan *p, int is_blocked, int type)
{
   if (is_blocked) {
      p->remotelyblocked |= type;
   } else {
      p->remotelyblocked &= ~type;
   }

   if (sig_ss7_callbacks.set_remotelyblocked) {
      sig_ss7_callbacks.set_remotelyblocked(p->chan_pvt, p->remotelyblocked);
   }
}

/*!
 * \internal
 * \brief Open the SS7 channel media path.
 * \since 1.8.12
 *
 * \param p Channel private control structure.
 *
 * \return Nothing
 */
static void sig_ss7_open_media(struct sig_ss7_chan *p)
{
   if (sig_ss7_callbacks.open_media) {
      sig_ss7_callbacks.open_media(p->chan_pvt);
   }
}

/*!
 * \internal
 * \brief Set the caller id information in the parent module.
 * \since 1.8
 *
 * \param p sig_ss7 channel structure.
 *
 * \return Nothing
 */
static void sig_ss7_set_caller_id(struct sig_ss7_chan *p)
{
   struct ast_party_caller caller;

   if (sig_ss7_callbacks.set_callerid) {
      ast_party_caller_init(&caller);

      caller.id.name.str = p->cid_name;
      caller.id.name.presentation = p->callingpres;
      caller.id.name.valid = 1;

      caller.id.number.str = p->cid_num;
      caller.id.number.plan = p->cid_ton;
      caller.id.number.presentation = p->callingpres;
      caller.id.number.valid = 1;

      if (!ast_strlen_zero(p->cid_subaddr)) {
         caller.id.subaddress.valid = 1;
         //caller.id.subaddress.type = 0;/* nsap */
         //caller.id.subaddress.odd_even_indicator = 0;
         caller.id.subaddress.str = p->cid_subaddr;
      }

      caller.ani.number.str = p->cid_ani;
      //caller.ani.number.plan = p->xxx;
      //caller.ani.number.presentation = p->xxx;
      caller.ani.number.valid = 1;

      caller.ani2 = p->cid_ani2;
      sig_ss7_callbacks.set_callerid(p->chan_pvt, &caller);
   }
}

/*!
 * \internal
 * \brief Set the Dialed Number Identifier.
 * \since 1.8
 *
 * \param p sig_ss7 channel structure.
 * \param dnid Dialed Number Identifier string.
 *
 * \return Nothing
 */
static void sig_ss7_set_dnid(struct sig_ss7_chan *p, const char *dnid)
{
   if (sig_ss7_callbacks.set_dnid) {
      sig_ss7_callbacks.set_dnid(p->chan_pvt, dnid);
   }
}

static int sig_ss7_play_tone(struct sig_ss7_chan *p, enum sig_ss7_tone tone)
{
   int res;

   if (sig_ss7_callbacks.play_tone) {
      res = sig_ss7_callbacks.play_tone(p->chan_pvt, tone);
   } else {
      res = -1;
   }
   return res;
}

static int sig_ss7_set_echocanceller(struct sig_ss7_chan *p, int enable)
{
   if (sig_ss7_callbacks.set_echocanceller) {
      return sig_ss7_callbacks.set_echocanceller(p->chan_pvt, enable);
   }
   return -1;
}

static void sig_ss7_loopback(struct sig_ss7_chan *p, int enable)
{
   if (p->loopedback != enable) {
      p->loopedback = enable;
      if (sig_ss7_callbacks.set_loopback) {
         sig_ss7_callbacks.set_loopback(p->chan_pvt, enable);
      }
   }
}

static struct ast_channel *sig_ss7_new_ast_channel(struct sig_ss7_chan *p, int state,
   int ulaw, int transfercapability, char *exten,
   const struct ast_assigned_ids *assignedids, const struct ast_channel *requestor)
{
   struct ast_channel *ast;

   if (sig_ss7_callbacks.new_ast_channel) {
      ast = sig_ss7_callbacks.new_ast_channel(p->chan_pvt, state, ulaw, exten,
         assignedids, requestor);
   } else {
      return NULL;
   }
   if (!ast) {
      return NULL;
   }

   if (!p->owner) {
      p->owner = ast;
   }

   if (p->outgoing) {
      p->do_hangup = SS7_HANGUP_FREE_CALL;
   } else {
      p->do_hangup = SS7_HANGUP_SEND_REL;
   }

   ast_channel_transfercapability_set(ast, transfercapability);
   pbx_builtin_setvar_helper(ast, "TRANSFERCAPABILITY",
      ast_transfercapability2str(transfercapability));
   if (transfercapability & AST_TRANS_CAP_DIGITAL) {
      sig_ss7_set_digital(p, 1);
   }

   return ast;
}

static void sig_ss7_handle_link_exception(struct sig_ss7_linkset *linkset, int which)
{
   if (sig_ss7_callbacks.handle_link_exception) {
      sig_ss7_callbacks.handle_link_exception(linkset, which);
   }
}

static struct sig_ss7_linkset *sig_ss7_find_linkset(struct ss7 *ss7)
{
   if (sig_ss7_callbacks.find_linkset) {
      return sig_ss7_callbacks.find_linkset(ss7);
   }
   return NULL;
}

/*!
 * \internal
 * \brief Determine if a private channel structure is available.
 *
 * \param pvt Channel to determine if available.
 *
 * \return TRUE if the channel is available.
 */
static int sig_ss7_is_chan_available(struct sig_ss7_chan *pvt)
{
   if (pvt->inservice && !pvt->inalarm && !pvt->owner && !pvt->ss7call
      && pvt->call_level == SIG_SS7_CALL_LEVEL_IDLE
      && !pvt->locallyblocked && !pvt->remotelyblocked) {
      return 1;
   }
   return 0;
}

/*!
 * \internal
 * \brief Obtain the sig_ss7 owner channel lock if the owner exists.
 * \since 1.8
 *
 * \param ss7 SS7 linkset control structure.
 * \param chanpos Channel position in the span.
 *
 * \note Assumes the ss7->lock is already obtained.
 * \note Assumes the sig_ss7_lock_private(ss7->pvts[chanpos]) is already obtained.
 *
 * \return Nothing
 */
static void sig_ss7_lock_owner(struct sig_ss7_linkset *ss7, int chanpos)
{
   for (;;) {
      if (!ss7->pvts[chanpos]->owner) {
         /* There is no owner lock to get. */
         break;
      }
      if (!ast_channel_trylock(ss7->pvts[chanpos]->owner)) {
         /* We got the lock */
         break;
      }

      /* Avoid deadlock */
      sig_ss7_unlock_private(ss7->pvts[chanpos]);
      DEADLOCK_AVOIDANCE(&ss7->lock);
      sig_ss7_lock_private(ss7->pvts[chanpos]);
   }
}

/*!
 * \internal
 * \brief Queue the given frame onto the owner channel.
 * \since 1.8
 *
 * \param ss7 SS7 linkset control structure.
 * \param chanpos Channel position in the span.
 * \param frame Frame to queue onto the owner channel.
 *
 * \note Assumes the ss7->lock is already obtained.
 * \note Assumes the sig_ss7_lock_private(ss7->pvts[chanpos]) is already obtained.
 *
 * \return Nothing
 */
static void sig_ss7_queue_frame(struct sig_ss7_linkset *ss7, int chanpos, struct ast_frame *frame)
{
   sig_ss7_lock_owner(ss7, chanpos);
   if (ss7->pvts[chanpos]->owner) {
      ast_queue_frame(ss7->pvts[chanpos]->owner, frame);
      ast_channel_unlock(ss7->pvts[chanpos]->owner);
   }
}

/*!
 * \internal
 * \brief Queue a control frame of the specified subclass onto the owner channel.
 * \since 1.8
 *
 * \param ss7 SS7 linkset control structure.
 * \param chanpos Channel position in the span.
 * \param subclass Control frame subclass to queue onto the owner channel.
 *
 * \note Assumes the ss7->lock is already obtained.
 * \note Assumes the sig_ss7_lock_private(ss7->pvts[chanpos]) is already obtained.
 *
 * \return Nothing
 */
static void sig_ss7_queue_control(struct sig_ss7_linkset *ss7, int chanpos, int subclass)
{
   struct ast_frame f = {AST_FRAME_CONTROL, };
   struct sig_ss7_chan *p = ss7->pvts[chanpos];

   if (sig_ss7_callbacks.queue_control) {
      sig_ss7_callbacks.queue_control(p->chan_pvt, subclass);
   }

   f.subclass.integer = subclass;
   sig_ss7_queue_frame(ss7, chanpos, &f);
}

/*!
 * \internal
 * \brief Queue a PVT_CAUSE_CODE frame onto the owner channel.
 * \since 11.0
 *
 * \param owner Owner channel of the pvt.
 * \param cause String describing the cause to be placed into the frame.
 *
 * \note Assumes the linkset->lock is already obtained.
 * \note Assumes the sig_ss7_lock_private(linkset->pvts[chanpos]) is already obtained.
 * \note Assumes linkset->pvts[chanpos]->owner is non-NULL and its lock is already obtained.
 *
 * \return Nothing
 */
static void ss7_queue_pvt_cause_data(struct ast_channel *owner, const char *cause, int ast_cause)
{
   struct ast_control_pvt_cause_code *cause_code;
   int datalen = sizeof(*cause_code) + strlen(cause);

   cause_code = ast_alloca(datalen);
   memset(cause_code, 0, datalen);
   cause_code->ast_cause = ast_cause;
   ast_copy_string(cause_code->chan_name, ast_channel_name(owner), AST_CHANNEL_NAME);
   ast_copy_string(cause_code->code, cause, datalen + 1 - sizeof(*cause_code));
   ast_queue_control_data(owner, AST_CONTROL_PVT_CAUSE_CODE, cause_code, datalen);
   ast_channel_hangupcause_hash_set(owner, cause_code, datalen);
}


/*!
 * \brief Find the channel position by CIC/DPC.
 *
 * \param linkset SS7 linkset control structure.
 * \param cic Circuit Identification Code
 * \param dpc Destination Point Code
 *
 * \retval chanpos on success.
 * \retval -1 on error.
 */
int sig_ss7_find_cic(struct sig_ss7_linkset *linkset, int cic, unsigned int dpc)
{
   int i;
   int winner = -1;
   for (i = 0; i < linkset->numchans; i++) {
      if (linkset->pvts[i] && (linkset->pvts[i]->dpc == dpc && linkset->pvts[i]->cic == cic)) {
         winner = i;
         break;
      }
   }
   return winner;
}

/*!
 * \internal
 * \brief Find the channel position by CIC/DPC and gripe if not found.
 *
 * \param linkset SS7 linkset control structure.
 * \param cic Circuit Identification Code
 * \param dpc Destination Point Code
 * \param msg_name Message type name that failed.
 *
 * \retval chanpos on success.
 * \retval -1 on error.
 */
static int ss7_find_cic_gripe(struct sig_ss7_linkset *linkset, int cic, unsigned int dpc, const char *msg_name)
{
   int chanpos;

   chanpos = sig_ss7_find_cic(linkset, cic, dpc);
   if (chanpos < 0) {
      ast_log(LOG_WARNING, "Linkset %d: SS7 %s requested on unconfigured CIC/DPC %d/%d.\n",
         linkset->span, msg_name, cic, dpc);
      return -1;
   }
   return chanpos;
}

static struct sig_ss7_chan *ss7_find_pvt(struct ss7 *ss7, int cic, unsigned int dpc)
{
   int chanpos;
   struct sig_ss7_linkset *winner;

   winner = sig_ss7_find_linkset(ss7);
   if (winner && (chanpos = sig_ss7_find_cic(winner, cic, dpc)) > -1) {
      return winner->pvts[chanpos];
   }
   return NULL;
}

int sig_ss7_cb_hangup(struct ss7 *ss7, int cic, unsigned int dpc, int cause, int do_hangup)
{
   struct sig_ss7_chan *p;
   int res;

   if (!(p = ss7_find_pvt(ss7, cic, dpc))) {
      return SS7_CIC_NOT_EXISTS;
   }

   sig_ss7_lock_private(p);
   if (p->owner) {
      ast_channel_hangupcause_set(p->owner, cause);
      ast_channel_softhangup_internal_flag_add(p->owner, AST_SOFTHANGUP_DEV);
      p->do_hangup = do_hangup;
      res = SS7_CIC_USED;
   } else {
      res = SS7_CIC_IDLE;
   }
   sig_ss7_unlock_private(p);

   return res;
}

void sig_ss7_cb_call_null(struct ss7 *ss7, struct isup_call *call, int lock)
{
   int i;
   struct sig_ss7_linkset *winner;

   winner = sig_ss7_find_linkset(ss7);
   if (!winner) {
      return;
   }
   for (i = 0; i < winner->numchans; i++) {
      if (winner->pvts[i] && (winner->pvts[i]->ss7call == call)) {
         if (lock) {
            sig_ss7_lock_private(winner->pvts[i]);
         }
         winner->pvts[i]->ss7call = NULL;
         if (winner->pvts[i]->owner) {
            ast_channel_hangupcause_set(winner->pvts[i]->owner, AST_CAUSE_NORMAL_TEMPORARY_FAILURE);
            ast_channel_softhangup_internal_flag_add(winner->pvts[i]->owner, AST_SOFTHANGUP_DEV);
         }
         if (lock) {
            sig_ss7_unlock_private(winner->pvts[i]);
         }
         ast_log(LOG_WARNING, "libss7 asked set ss7 call to NULL on CIC %d DPC %d\n", winner->pvts[i]->cic, winner->pvts[i]->dpc);
      }
   }
}

void sig_ss7_cb_notinservice(struct ss7 *ss7, int cic, unsigned int dpc)
{
   struct sig_ss7_chan *p;

   if (!(p = ss7_find_pvt(ss7, cic, dpc))) {
      return;
   }

   sig_ss7_lock_private(p);
   sig_ss7_set_inservice(p, 0);
   sig_ss7_unlock_private(p);
}

/*!
 * \internal
 * \brief Check if CICs in a range belong to the linkset for a given DPC.
 * \since 11.0
 *
 * \param linkset SS7 linkset control structure.
 * \param startcic Circuit Identification Code to start from
 * \param endcic Circuit Identification Code to search up-to
 * \param dpc Destination Point Code
 * \param state Array containing the status of the search
 *
 * \retval Nothing.
 */
static void ss7_check_range(struct sig_ss7_linkset *linkset, int startcic, int endcic, unsigned int dpc, unsigned char *state)
{
   int cic;

   for (cic = startcic; cic <= endcic; cic++) {
      if (state[cic - startcic] && sig_ss7_find_cic(linkset, cic, dpc) == -1) {
         state[cic - startcic] = 0;
      }
   }
}

static int ss7_match_range(struct sig_ss7_chan *pvt, int startcic, int endcic, unsigned int dpc)
{
   if (pvt && pvt->dpc == dpc && pvt->cic >= startcic && pvt->cic <= endcic) {
      return 1;
   }

   return 0;
}

/*!
 * \internal
 * \brief Check if a range is defined for the given DPC.
 * \since 11.0
 *
 * \param linkset SS7 linkset control structure.
 * \param startcic Start CIC of the range to clear.
 * \param endcic End CIC of the range to clear.
 * \param dpc Destination Point Code.
 *
 * \note Assumes the linkset->lock is already obtained.
 *
 * \return TRUE if all CICs in the range are present
 */
int sig_ss7_find_cic_range(struct sig_ss7_linkset *linkset, int startcic, int endcic, unsigned int dpc)
{
   int i, found = 0;

   for (i = 0; i < linkset->numchans; i++) {
      if (ss7_match_range(linkset->pvts[i], startcic, endcic, dpc)) {
         found++;
      }
   }

   if (found == endcic - startcic + 1) {
      return  1;
   }

   return 0;
}

static void ss7_handle_cqm(struct sig_ss7_linkset *linkset, ss7_event *e)
{
   unsigned char status[32];
   struct sig_ss7_chan *p = NULL;
   int i;
   int offset;
   int chanpos;

   memset(status, 0, sizeof(status));
   for (i = 0; i < linkset->numchans; i++) {
      if (ss7_match_range(linkset->pvts[i], e->cqm.startcic, e->cqm.endcic, e->cqm.opc)) {
         p = linkset->pvts[i];
         sig_ss7_lock_private(p);
         offset = p->cic - e->cqm.startcic;
         status[offset] = 0;
         if (p->locallyblocked) {
            status[offset] |= (1 << 0) | (1 << 4);
         }
         if (p->remotelyblocked) {
            status[offset] |= (1 << 1) | (1 << 5);
         }
         if (p->ss7call) {
            if (p->outgoing) {
               status[offset] |= (1 << 3);
            } else {
               status[offset] |= (1 << 2);
            }
         } else {
            status[offset] |= 0x3 << 2;
         }
         sig_ss7_unlock_private(p);
      }
   }

   if (p) {
      isup_cqr(linkset->ss7, e->cqm.startcic, e->cqm.endcic, e->cqm.opc, status);
   } else {
      ast_log(LOG_WARNING, "Could not find any equipped circuits within CQM CICs\n");
   }

   chanpos = sig_ss7_find_cic(linkset, e->cqm.startcic, e->cqm.opc);
   if (chanpos < 0) {
      isup_free_call(linkset->ss7, e->cqm.call);
      return;
   }
   p = linkset->pvts[chanpos];
   sig_ss7_lock_private(p);
   p->ss7call = e->cqm.call;
   if (!p->owner) {
      p->ss7call = isup_free_call_if_clear(linkset->ss7, e->cqm.call);
   }
   sig_ss7_unlock_private(p);
}

static inline void ss7_hangup_cics(struct sig_ss7_linkset *linkset, int startcic, int endcic, unsigned int dpc)
{
   int i;

   for (i = 0; i < linkset->numchans; i++) {
      if (ss7_match_range(linkset->pvts[i], startcic, endcic, dpc)) {
         sig_ss7_lock_private(linkset->pvts[i]);
         sig_ss7_lock_owner(linkset, i);
         if (linkset->pvts[i]->owner) {
            ast_softhangup_nolock(linkset->pvts[i]->owner, AST_SOFTHANGUP_DEV);
            ast_channel_unlock(linkset->pvts[i]->owner);
         }
         sig_ss7_unlock_private(linkset->pvts[i]);
      }
   }
}

/*!
 * \param linkset SS7 linkset control structure.
 * \param startcic Start CIC of the range to clear.
 * \param endcic End CIC of the range to clear.
 * \param dpc Destination Point Code.
 * \param state Affected CICs from the operation. NULL for all CICs in the range.
 * \param block Operation to perform. TRUE to block.
 * \param remotely Direction of the blocking. TRUE to block/unblock remotely.
 * \param type Blocking type - hardware or maintenance.
 *
 * \note Assumes the linkset->lock is already obtained.
 * \note Must be called without sig_ss7_lock_private() obtained.
 *
 * \return Nothing.
 */
static inline void ss7_block_cics(struct sig_ss7_linkset *linkset, int startcic, int endcic, unsigned int dpc, unsigned char state[], int block, int remotely, int type)
{
   int i;

   for (i = 0; i < linkset->numchans; i++) {
      if (ss7_match_range(linkset->pvts[i], startcic, endcic, dpc)) {
         sig_ss7_lock_private(linkset->pvts[i]);
         if (state) {
            if (state[linkset->pvts[i]->cic - startcic]) {

               if (remotely) {
                  sig_ss7_set_remotelyblocked(linkset->pvts[i], block, type);
               } else {
                  sig_ss7_set_locallyblocked(linkset->pvts[i], block, type);
               }

               sig_ss7_lock_owner(linkset, i);
               if (linkset->pvts[i]->owner) {
                  if (ast_channel_state(linkset->pvts[i]->owner) == AST_STATE_DIALING
                     && linkset->pvts[i]->call_level < SIG_SS7_CALL_LEVEL_PROCEEDING) {
                     ast_channel_hangupcause_set(linkset->pvts[i]->owner, SS7_CAUSE_TRY_AGAIN);
                  }
                  ast_channel_unlock(linkset->pvts[i]->owner);
               }
            }
         } else {
            if (remotely) {
               sig_ss7_set_remotelyblocked(linkset->pvts[i], block, type);
            } else {
               sig_ss7_set_locallyblocked(linkset->pvts[i], block, type);
            }
         }
         sig_ss7_unlock_private(linkset->pvts[i]);
      }
   }
}

/*!
 * \param linkset SS7 linkset control structure.
 * \param startcic Start CIC of the range to set in service.
 * \param endcic End CIC of the range to set in service.
 * \param dpc Destination Point Code.
 *
 * \note Must be called without sig_ss7_lock_private() obtained.
 *
 * \return Nothing.
 */
static void ss7_inservice(struct sig_ss7_linkset *linkset, int startcic, int endcic, unsigned int dpc)
{
   int i;

   for (i = 0; i < linkset->numchans; i++) {
      if (ss7_match_range(linkset->pvts[i], startcic, endcic, dpc)) {
         sig_ss7_lock_private(linkset->pvts[i]);
         sig_ss7_set_inservice(linkset->pvts[i], 1);
         sig_ss7_unlock_private(linkset->pvts[i]);
      }
   }
}

static int ss7_find_alloc_call(struct sig_ss7_chan *p)
{
   if (!p) {
      return 0;
   }

   if (!p->ss7call) {
      p->ss7call = isup_new_call(p->ss7->ss7, p->cic, p->dpc, 0);
      if (!p->ss7call) {
         return 0;
      }
   }
   return 1;
}

/*
 * XXX This routine is not tolerant of holes in the pvts[] array.
 * XXX This routine assumes the cic's in the pvts[] array are sorted.
 *
 * Probably the easiest way to deal with the invalid assumptions
 * is to have a local pvts[] array and sort it by dpc and cic.
 * Then the existing algorithm could work.
 */
static void ss7_reset_linkset(struct sig_ss7_linkset *linkset)
{
   int i, startcic, endcic, dpc;
   struct sig_ss7_chan *p;

   if (linkset->numchans <= 0) {
      return;
   }

   startcic = linkset->pvts[0]->cic;
   p = linkset->pvts[0];
   /* DB: CIC's DPC fix */
   dpc = linkset->pvts[0]->dpc;

   for (i = 0; i < linkset->numchans; i++) {
      if (linkset->pvts[i+1]
         && linkset->pvts[i+1]->dpc == dpc
         && linkset->pvts[i+1]->cic - linkset->pvts[i]->cic == 1
         && linkset->pvts[i]->cic - startcic < (linkset->type == SS7_ANSI ? 24 : 31)) {
         continue;
      } else {
         endcic = linkset->pvts[i]->cic;
         ast_verb(1, "Resetting CICs %d to %d\n", startcic, endcic);

         sig_ss7_lock_private(p);
         if (!ss7_find_alloc_call(p)) {
            ast_log(LOG_ERROR, "Unable to allocate new ss7call\n");
         } else if (!(endcic - startcic)) {  /* GRS range can not be 0 - use RSC instead */
            isup_rsc(linkset->ss7, p->ss7call);
         } else {
            isup_grs(linkset->ss7, p->ss7call, endcic);
         }
         sig_ss7_unlock_private(p);

         /* DB: CIC's DPC fix */
         if (linkset->pvts[i+1]) {
            startcic = linkset->pvts[i+1]->cic;
            dpc = linkset->pvts[i+1]->dpc;
            p = linkset->pvts[i+1];
         }
      }
   }
}

/*!
 * \internal
 * \brief Complete the RSC procedure started earlier
 * \since 11.0
 *
 * \param p Signaling private structure pointer.
 *
 * \note Assumes the ss7->lock is already obtained.
 * \note Assumes sig_ss7_lock_private(p) is already obtained.
 *
 * \return Nothing.
 */
static void ss7_do_rsc(struct sig_ss7_chan *p)
{
   if (!p || !p->ss7call) {
      return;
   }

   isup_rsc(p->ss7->ss7, p->ss7call);

   if (p->locallyblocked & SS7_BLOCKED_MAINTENANCE) {
      isup_blo(p->ss7->ss7, p->ss7call);
   } else {
      sig_ss7_set_locallyblocked(p, 0, SS7_BLOCKED_MAINTENANCE | SS7_BLOCKED_HARDWARE);
   }
}

/*!
 * \internal
 * \brief Start RSC procedure on a specific link
 * \since 11.0
 *
 * \param ss7 SS7 linkset control structure.
 * \param which Channel position in the span.
 *
 * \note Assumes the ss7->lock is already obtained.
 * \note Assumes the sig_ss7_lock_private(ss7->pvts[chanpos]) is already obtained.
 *
 * \return TRUE on success
 */
static int ss7_start_rsc(struct sig_ss7_linkset *linkset, int which)
{
   if (!linkset->pvts[which]) {
      return 0;
   }

   if (!ss7_find_alloc_call(linkset->pvts[which])) {
      return 0;
   }

   sig_ss7_set_remotelyblocked(linkset->pvts[which], 0, SS7_BLOCKED_MAINTENANCE | SS7_BLOCKED_HARDWARE);
   sig_ss7_set_inservice(linkset->pvts[which], 0);
   sig_ss7_loopback(linkset->pvts[which], 0);

   sig_ss7_lock_owner(linkset, which);
   if (linkset->pvts[which]->owner) {
      ast_channel_hangupcause_set(linkset->pvts[which]->owner, AST_CAUSE_NORMAL_CLEARING);
      ast_softhangup_nolock(linkset->pvts[which]->owner, AST_SOFTHANGUP_DEV);
      ast_channel_unlock(linkset->pvts[which]->owner);
      linkset->pvts[which]->do_hangup = SS7_HANGUP_SEND_RSC;
   } else {
      ss7_do_rsc(linkset->pvts[which]);
   }

   return 1;
}

/*!
 * \internal
 * \brief Determine if a private channel structure is available.
 * \since 11.0
 *
 * \param linkset SS7 linkset control structure.
 * \param startcic Start CIC of the range to clear.
 * \param endcic End CIC of the range to clear.
 * \param dpc Destination Point Code.
 * \param do_hangup What we have to do to clear the call.
 *
 * \note Assumes the linkset->lock is already obtained.
 * \note Must be called without sig_ss7_lock_private() obtained.
 *
 * \return Nothing.
 */
static void ss7_clear_channels(struct sig_ss7_linkset *linkset, int startcic, int endcic, int dpc, int do_hangup)
{
   int i;

   for (i = 0; i < linkset->numchans; i++) {
      if (ss7_match_range(linkset->pvts[i], startcic, endcic, dpc)) {
         sig_ss7_lock_private(linkset->pvts[i]);
         sig_ss7_set_inservice(linkset->pvts[i], 0);
         sig_ss7_lock_owner(linkset, i);
         if (linkset->pvts[i]->owner) {
            ast_channel_hangupcause_set(linkset->pvts[i]->owner,
                                 AST_CAUSE_NORMAL_CLEARING);
            ast_softhangup_nolock(linkset->pvts[i]->owner, AST_SOFTHANGUP_DEV);
            ast_channel_unlock(linkset->pvts[i]->owner);
            linkset->pvts[i]->do_hangup = (linkset->pvts[i]->cic != startcic) ?
                                 do_hangup : SS7_HANGUP_DO_NOTHING;
         } else if (linkset->pvts[i] && linkset->pvts[i]->cic != startcic) {
            isup_free_call(linkset->pvts[i]->ss7->ss7, linkset->pvts[i]->ss7call);
            linkset->pvts[i]->ss7call = NULL;
         }
         sig_ss7_unlock_private(linkset->pvts[i]);
      }
   }
}

/*!
 * \internal
 *
 * \param p Signaling private structure pointer.
 * \param linkset SS7 linkset control structure.
 *
 * \note Assumes the linkset->lock is already obtained.
 * \note Assumes the sig_ss7_lock_private(ss7->pvts[chanpos]) is already obtained.
 *
 * \return Nothing.
 */
static void ss7_start_call(struct sig_ss7_chan *p, struct sig_ss7_linkset *linkset)
{
   struct ss7 *ss7 = linkset->ss7;
   int law;
   struct ast_channel *c;
   char tmp[256];
   char *strp;
   ast_callid callid = 0;
   int callid_created = ast_callid_threadstorage_auto(&callid);

   if (!(linkset->flags & LINKSET_FLAG_EXPLICITACM)) {
      p->call_level = SIG_SS7_CALL_LEVEL_PROCEEDING;
      isup_acm(ss7, p->ss7call);
   } else {
      p->call_level = SIG_SS7_CALL_LEVEL_SETUP;
   }

   /* Companding law is determined by SS7 signaling type. */
   if (linkset->type == SS7_ITU) {
      law = SIG_SS7_ALAW;
   } else {
      law = SIG_SS7_ULAW;
   }

   isup_set_echocontrol(p->ss7call, (linkset->flags & LINKSET_FLAG_DEFAULTECHOCONTROL) ? 1 : 0);

   /*
    * Release the SS7 lock while we create the channel so other
    * threads can send messages.  We must also release the private
    * lock to prevent deadlock while creating the channel.
    */
   ast_mutex_unlock(&linkset->lock);
   sig_ss7_unlock_private(p);
   c = sig_ss7_new_ast_channel(p, AST_STATE_RING, law, 0, p->exten, NULL, NULL);
   if (!c) {
      ast_log(LOG_WARNING, "Unable to start PBX on CIC %d\n", p->cic);
      ast_mutex_lock(&linkset->lock);
      sig_ss7_lock_private(p);
      isup_rel(linkset->ss7, p->ss7call, AST_CAUSE_SWITCH_CONGESTION);
      p->call_level = SIG_SS7_CALL_LEVEL_IDLE;
      ast_callid_threadstorage_auto_clean(callid, callid_created);
      return;
   }

   /* Hold the channel and private lock while we setup the channel. */
   ast_channel_lock(c);
   sig_ss7_lock_private(p);

   ast_channel_stage_snapshot(c);

   /*
    * It is reasonably safe to set the following
    * channel variables while the channel private
    * structure is locked.  The PBX has not been
    * started yet and it is unlikely that any other task
    * will do anything with the channel we have just
    * created.
    *
    * We only reference these variables in the context of the ss7_linkset function
    * when receiving either and IAM or a COT message.
    */
   if (!ast_strlen_zero(p->charge_number)) {
      pbx_builtin_setvar_helper(c, "SS7_CHARGE_NUMBER", p->charge_number);
      /* Clear this after we set it */
      p->charge_number[0] = 0;
   }
   if (!ast_strlen_zero(p->gen_add_number)) {
      pbx_builtin_setvar_helper(c, "SS7_GENERIC_ADDRESS", p->gen_add_number);
      /* Clear this after we set it */
      p->gen_add_number[0] = 0;
   }
   if (!ast_strlen_zero(p->jip_number)) {
      pbx_builtin_setvar_helper(c, "SS7_JIP", p->jip_number);
      /* Clear this after we set it */
      p->jip_number[0] = 0;
   }
   if (!ast_strlen_zero(p->gen_dig_number)) {
      pbx_builtin_setvar_helper(c, "SS7_GENERIC_DIGITS", p->gen_dig_number);
      /* Clear this after we set it */
      p->gen_dig_number[0] = 0;
   }

   snprintf(tmp, sizeof(tmp), "%d", p->gen_dig_type);
   pbx_builtin_setvar_helper(c, "SS7_GENERIC_DIGTYPE", tmp);
   /* Clear this after we set it */
   p->gen_dig_type = 0;

   snprintf(tmp, sizeof(tmp), "%d", p->gen_dig_scheme);
   pbx_builtin_setvar_helper(c, "SS7_GENERIC_DIGSCHEME", tmp);
   /* Clear this after we set it */
   p->gen_dig_scheme = 0;

   if (!ast_strlen_zero(p->lspi_ident)) {
      pbx_builtin_setvar_helper(c, "SS7_LSPI_IDENT", p->lspi_ident);
      /* Clear this after we set it */
      p->lspi_ident[0] = 0;
   }

   snprintf(tmp, sizeof(tmp), "%d", p->call_ref_ident);
   pbx_builtin_setvar_helper(c, "SS7_CALLREF_IDENT", tmp);
   /* Clear this after we set it */
   p->call_ref_ident = 0;

   snprintf(tmp, sizeof(tmp), "%d", p->call_ref_pc);
   pbx_builtin_setvar_helper(c, "SS7_CALLREF_PC", tmp);
   /* Clear this after we set it */
   p->call_ref_pc = 0;

   snprintf(tmp, sizeof(tmp), "%d", p->calling_party_cat);
   pbx_builtin_setvar_helper(c, "SS7_CALLING_PARTY_CATEGORY", tmp);
   /* Clear this after we set it */
   p->calling_party_cat = 0;

   if (p->redirect_counter) {
      struct ast_party_redirecting redirecting;

      switch (p->redirect_info_ind) {
      case 0:
         strp = "NO_REDIRECTION";
         break;
      case 1:
         strp = "CALL_REROUTED_PRES_ALLOWED";
         break;
      case 2:
         strp = "CALL_REROUTED_INFO_RESTRICTED";
         break;
      case 3:
         strp = "CALL_DIVERTED_PRES_ALLOWED";
         break;
      case 4:
         strp = "CALL_DIVERTED_INFO_RESTRICTED";
         break;
      case 5:
         strp = "CALL_REROUTED_PRES_RESTRICTED";
         break;
      case 6:
         strp = "CALL_DIVERTED_PRES_RESTRICTED";
         break;
      case 7:
         strp = "SPARE";
         break;
      default:
         strp = "NO_REDIRECTION";
         break;
      }
      pbx_builtin_setvar_helper(c, "SS7_REDIRECT_INFO_IND", strp);
      /* Clear this after we set it */
      p->redirect_info_ind = 0;

      ast_party_redirecting_init(&redirecting);

      if (p->redirect_info_counter) {
         redirecting.count = p->redirect_info_counter;
         if (p->redirect_info_counter != p->redirect_counter) {
            if (p->redirect_info_counter < p->redirect_counter) {
               redirecting.count = p->redirect_counter;
            }
            ast_log(LOG_WARNING, "Redirect counters differ: %u while info says %u - using %u\n",
               p->redirect_counter, p->redirect_info_counter, redirecting.count);
         }
         /* Clear this after we set it */
         p->redirect_info_counter = 0;
         p->redirect_counter = 0;
      }

      if (p->redirect_counter) {
         redirecting.count = p->redirect_counter;
         /* Clear this after we set it */
         p->redirect_counter = 0;
      }

      switch (p->redirect_info_orig_reas) {
      case SS7_REDIRECTING_REASON_UNKNOWN:
         redirecting.orig_reason.code = AST_REDIRECTING_REASON_UNKNOWN;
         break;
      case SS7_REDIRECTING_REASON_USER_BUSY:
         redirecting.orig_reason.code = AST_REDIRECTING_REASON_USER_BUSY;
         break;
      case SS7_REDIRECTING_REASON_NO_ANSWER:
         redirecting.orig_reason.code = AST_REDIRECTING_REASON_NO_ANSWER;
         break;
      case SS7_REDIRECTING_REASON_UNCONDITIONAL:
         redirecting.orig_reason.code = AST_REDIRECTING_REASON_UNCONDITIONAL;
         break;
      default:
         redirecting.orig_reason.code = AST_REDIRECTING_REASON_UNKNOWN;
         break;
      }

      switch (p->redirect_info_reas) {
      case SS7_REDIRECTING_REASON_UNKNOWN:
         redirecting.reason.code = AST_REDIRECTING_REASON_UNKNOWN;
         break;
      case SS7_REDIRECTING_REASON_USER_BUSY:
         redirecting.reason.code = AST_REDIRECTING_REASON_USER_BUSY;
         if (!p->redirect_info_orig_reas && redirecting.count == 1) {
            redirecting.orig_reason.code = AST_REDIRECTING_REASON_USER_BUSY;
         }
         break;
      case SS7_REDIRECTING_REASON_NO_ANSWER:
         redirecting.reason.code = AST_REDIRECTING_REASON_NO_ANSWER;
         if (!p->redirect_info_orig_reas && redirecting.count == 1) {
            redirecting.orig_reason.code = AST_REDIRECTING_REASON_NO_ANSWER;
         }
         break;
      case SS7_REDIRECTING_REASON_UNCONDITIONAL:
         redirecting.reason.code = AST_REDIRECTING_REASON_UNCONDITIONAL;
         if (!p->redirect_info_orig_reas && redirecting.count == 1) {
            redirecting.orig_reason.code = AST_REDIRECTING_REASON_UNCONDITIONAL;
         }
         break;
      case SS7_REDIRECTING_REASON_DEFLECTION_DURING_ALERTING:
      case SS7_REDIRECTING_REASON_DEFLECTION_IMMEDIATE_RESPONSE:
         redirecting.reason.code = AST_REDIRECTING_REASON_DEFLECTION;
         break;
      case SS7_REDIRECTING_REASON_UNAVAILABLE:
         redirecting.reason.code = AST_REDIRECTING_REASON_UNAVAILABLE;
         break;
      default:
         redirecting.reason.code = AST_REDIRECTING_REASON_UNKNOWN;
         break;
      }
      /* Clear this after we set it */
      p->redirect_info_orig_reas = 0;
      p->redirect_info_reas = 0;

      if (!ast_strlen_zero(p->redirecting_num)) {
         redirecting.from.number.str = ast_strdup(p->redirecting_num);
         redirecting.from.number.presentation = p->redirecting_presentation;
         redirecting.from.number.valid = 1;
         /* Clear this after we set it */
         p->redirecting_num[0] = 0;
      }

      if (!ast_strlen_zero(p->generic_name)) {
         redirecting.from.name.str = ast_strdup(p->generic_name);
         redirecting.from.name.presentation = p->redirecting_presentation;
         redirecting.from.name.valid = 1;
         /* Clear this after we set it */
         p->generic_name[0] = 0;
      }

      if (!ast_strlen_zero(p->orig_called_num)) {
         redirecting.orig.number.str = ast_strdup(p->orig_called_num);
         redirecting.orig.number.presentation = p->orig_called_presentation;
         redirecting.orig.number.valid = 1;
         /* Clear this after we set it */
         p->orig_called_num[0] = 0;
      } else if (redirecting.count == 1) {
         ast_party_id_copy(&redirecting.orig, &redirecting.from);
      }

      ast_channel_update_redirecting(c, &redirecting, NULL);
      ast_party_redirecting_free(&redirecting);
   }

   if (p->cug_indicator != ISUP_CUG_NON) {
      sprintf(tmp, "%d", p->cug_interlock_code);
      pbx_builtin_setvar_helper(c, "SS7_CUG_INTERLOCK_CODE", tmp);

      switch (p->cug_indicator) {
      case ISUP_CUG_NON:
         strp = "NON_CUG";
         break;
      case ISUP_CUG_OUTGOING_ALLOWED:
         strp = "OUTGOING_ALLOWED";
         break;
      case ISUP_CUG_OUTGOING_NOT_ALLOWED:
         strp = "OUTGOING_NOT_ALLOWED";
         break;
      default:
         strp = "SPARE";
         break;
      }
      pbx_builtin_setvar_helper(c, "SS7_CUG_INDICATOR", strp);

      if (!ast_strlen_zero(p->cug_interlock_ni)) {
         pbx_builtin_setvar_helper(c, "SS7_CUG_INTERLOCK_NI", p->cug_interlock_ni);
      }

      p->cug_indicator = ISUP_CUG_NON;
   }

   ast_channel_stage_snapshot_done(c);

   sig_ss7_unlock_private(p);
   ast_channel_unlock(c);

   if (ast_pbx_start(c)) {
      ast_log(LOG_WARNING, "Unable to start PBX on %s (CIC %d)\n", ast_channel_name(c), p->cic);
      ast_hangup(c);
   } else {
      ast_verb(3, "Accepting call to '%s' on CIC %d\n", p->exten, p->cic);
   }

   /* Must return with linkset and private lock. */
   ast_mutex_lock(&linkset->lock);
   sig_ss7_lock_private(p);
   ast_callid_threadstorage_auto_clean(callid, callid_created);
}

static void ss7_apply_plan_to_number(char *buf, size_t size, const struct sig_ss7_linkset *ss7, const char *number, const unsigned nai)
{
   if (ast_strlen_zero(number)) { /* make sure a number exists so prefix isn't placed on an empty string */
      if (size) {
         *buf = '\0';
      }
      return;
   }
   switch (nai) {
   case SS7_NAI_INTERNATIONAL:
      snprintf(buf, size, "%s%s", ss7->internationalprefix, number);
      break;
   case SS7_NAI_NATIONAL:
      snprintf(buf, size, "%s%s", ss7->nationalprefix, number);
      break;
   case SS7_NAI_SUBSCRIBER:
      snprintf(buf, size, "%s%s", ss7->subscriberprefix, number);
      break;
   case SS7_NAI_UNKNOWN:
      snprintf(buf, size, "%s%s", ss7->unknownprefix, number);
      break;
   case SS7_NAI_NETWORKROUTED:
      snprintf(buf, size, "%s%s", ss7->networkroutedprefix, number);
      break;
   default:
      snprintf(buf, size, "%s", number);
      break;
   }
}

static int ss7_pres_scr2cid_pres(char presentation_ind, char screening_ind)
{
   return ((presentation_ind & 0x3) << 5) | (screening_ind & 0x3);
}

/*!
 * \internal
 * \brief Set callid threadstorage for the ss7_linkset thread to that of an existing channel
 *
 * \param linkset ss7 span control structure.
 * \param chanpos channel position in the span
 *
 * \note Assumes the ss7->lock is already obtained.
 * \note Assumes the sig_ss7_lock_private(ss7->pvts[chanpos]) is already obtained.
 *
 * \return The callid bound to the channel which has also been bound to threadstorage
 *         if it exists. If this returns non-zero, the threadstorage should be unbound
 *         before the while loop wraps in ss7_linkset.
 */
static ast_callid func_ss7_linkset_callid(struct sig_ss7_linkset *linkset, int chanpos)
{
   ast_callid callid = 0;
   sig_ss7_lock_owner(linkset, chanpos);
   if (linkset->pvts[chanpos]->owner) {
      callid = ast_channel_callid(linkset->pvts[chanpos]->owner);
      ast_channel_unlock(linkset->pvts[chanpos]->owner);
      if (callid) {
         ast_callid_threadassoc_add(callid);
      }
   }

   return callid;
}

/*!
 * \internal
 * \brief Proceed with the call based on the extension matching status
 * is matching in the dialplan.
 * \since 11.0
 *
 * \param linkset ss7 span control structure.
 * \param p Signaling private structure pointer.
 * \param e Event causing the match.
 *
 * \note Assumes the linkset->lock is already obtained.
 * \note Assumes the sig_ss7_lock_private(ss7->pvts[chanpos]) is already obtained.
 *
 * \return Nothing.
 */
static void ss7_match_extension(struct sig_ss7_linkset *linkset, struct sig_ss7_chan *p, ss7_event *e)
{
   ast_verb(3, "SS7 exten: %s complete: %d\n", p->exten, p->called_complete);

   if (!p->called_complete
      && linkset->type == SS7_ITU /* ANSI does not support overlap dialing. */
      && ast_matchmore_extension(NULL, p->context, p->exten, 1, p->cid_num)
      && !isup_start_digittimeout(linkset->ss7, p->ss7call)) {
      /* Wait for more digits. */
      return;
   }
   if (ast_exists_extension(NULL, p->context, p->exten, 1, p->cid_num)) {
      /* DNID is complete */
      p->called_complete = 1;
      sig_ss7_set_dnid(p, p->exten);

      /* If COT successful start call! */
      if ((e->e == ISUP_EVENT_IAM)
         ? !(e->iam.cot_check_required || e->iam.cot_performed_on_previous_cic)
         : (!(e->sam.cot_check_required || e->sam.cot_performed_on_previous_cic) || e->sam.cot_check_passed)) {
         ss7_start_call(p, linkset);
      }
      return;
   }

   ast_debug(1, "Call on CIC for unconfigured extension %s\n", p->exten);
   isup_rel(linkset->ss7, (e->e == ISUP_EVENT_IAM) ? e->iam.call : e->sam.call, AST_CAUSE_UNALLOCATED);
}

/* This is a thread per linkset that handles all received events from libss7. */
void *ss7_linkset(void *data)
{
   int res, i;
   struct timeval *next = NULL, tv;
   struct sig_ss7_linkset *linkset = (struct sig_ss7_linkset *) data;
   struct ss7 *ss7 = linkset->ss7;
   ss7_event *e = NULL;
   struct sig_ss7_chan *p;
   struct pollfd pollers[SIG_SS7_NUM_DCHANS];
   unsigned char mb_state[255];
   int nextms;

#define SS7_MAX_POLL 60000 /* Maximum poll time in ms. */

   pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);

   ss7_set_debug(ss7, SIG_SS7_DEBUG_DEFAULT);
   ast_mutex_lock(&linkset->lock);
   ss7_start(ss7);
   ast_mutex_unlock(&linkset->lock);

   for (;;) {
      ast_mutex_lock(&linkset->lock);
      if ((next = ss7_schedule_next(ss7))) {
         tv = ast_tvnow();
         tv.tv_sec = next->tv_sec - tv.tv_sec;
         tv.tv_usec = next->tv_usec - tv.tv_usec;
         if (tv.tv_usec < 0) {
            tv.tv_usec += 1000000;
            tv.tv_sec -= 1;
         }
         if (tv.tv_sec < 0) {
            tv.tv_sec = 0;
            tv.tv_usec = 0;
         }
         nextms = tv.tv_sec * 1000;
         nextms += tv.tv_usec / 1000;
         if (SS7_MAX_POLL < nextms) {
            nextms = SS7_MAX_POLL;
         }
      } else {
         nextms = SS7_MAX_POLL;
      }

      for (i = 0; i < linkset->numsigchans; i++) {
         pollers[i].fd = linkset->fds[i];
         pollers[i].events = ss7_pollflags(ss7, linkset->fds[i]);
         pollers[i].revents = 0;
      }
      ast_mutex_unlock(&linkset->lock);

      pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
      pthread_testcancel();
      res = poll(pollers, linkset->numsigchans, nextms);
      pthread_testcancel();
      pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);

      ast_mutex_lock(&linkset->lock);
      if ((res < 0) && (errno != EINTR)) {
         ast_log(LOG_ERROR, "poll(%s)\n", strerror(errno));
      } else if (!res) {
         ss7_schedule_run(ss7);
      }

      for (i = 0; i < linkset->numsigchans; i++) {
         if (pollers[i].revents & POLLPRI) {
            sig_ss7_handle_link_exception(linkset, i);
         }
         if (pollers[i].revents & POLLIN) {
            res = ss7_read(ss7, pollers[i].fd);
         }
         if (pollers[i].revents & POLLOUT) {
            res = ss7_write(ss7, pollers[i].fd);
            if (res < 0) {
               ast_debug(1, "Error in write %s\n", strerror(errno));
            }
         }
      }

      while ((e = ss7_check_event(ss7))) {
         ast_callid callid = 0;
         int chanpos = -1;
         char cause_str[30];

         if (linkset->debug) {
            ast_verbose("Linkset %d: Processing event: %s\n",
               linkset->span, ss7_event2str(e->e));
         }

         switch (e->e) {
         case SS7_EVENT_UP:
            if (linkset->state != LINKSET_STATE_UP) {
               ast_verb(1, "--- SS7 Up ---\n");
               ss7_reset_linkset(linkset);
            }
            linkset->state = LINKSET_STATE_UP;
            break;
         case SS7_EVENT_DOWN:
            ast_verb(1, "--- SS7 Down ---\n");
            linkset->state = LINKSET_STATE_DOWN;
            for (i = 0; i < linkset->numchans; i++) {
               p = linkset->pvts[i];
               if (p) {
                  sig_ss7_set_inservice(p, 0);
                  if (linkset->flags & LINKSET_FLAG_INITIALHWBLO) {
                     sig_ss7_set_remotelyblocked(p, 1, SS7_BLOCKED_HARDWARE);
                  }
               }
            }
            break;
         case MTP2_LINK_UP:
            ast_verb(1, "MTP2 link up (SLC %d)\n", e->gen.data);
            break;
         case MTP2_LINK_DOWN:
            ast_log(LOG_WARNING, "MTP2 link down (SLC %d)\n", e->gen.data);
            break;
         case ISUP_EVENT_CPG:
            chanpos = ss7_find_cic_gripe(linkset, e->cpg.cic, e->cpg.opc, "CPG");
            if (chanpos < 0) {
               isup_free_call(ss7, e->cpg.call);
               break;
            }
            p = linkset->pvts[chanpos];
            sig_ss7_lock_private(p);
            callid = func_ss7_linkset_callid(linkset, chanpos);

            switch (e->cpg.event) {
            case CPG_EVENT_ALERTING:
               if (p->call_level < SIG_SS7_CALL_LEVEL_ALERTING) {
                  p->call_level = SIG_SS7_CALL_LEVEL_ALERTING;
               }
               sig_ss7_lock_owner(linkset, chanpos);
               if (p->owner) {
                  ast_setstate(p->owner, AST_STATE_RINGING);
                  if (!ast_strlen_zero(e->cpg.connected_num)) {
                     struct ast_party_connected_line ast_connected;
                     char connected_num[AST_MAX_EXTENSION];

                     ast_party_connected_line_init(&ast_connected);
                     ast_connected.id.number.presentation =
                        ss7_pres_scr2cid_pres(e->cpg.connected_presentation_ind,
                        e->cpg.connected_screening_ind);
                     ss7_apply_plan_to_number(connected_num, sizeof(connected_num),
                        linkset, e->cpg.connected_num, e->cpg.connected_nai);
                     ast_connected.id.number.str = ast_strdup(connected_num);
                     ast_connected.id.number.valid = 1;
                     ast_channel_queue_connected_line_update(p->owner, &ast_connected, NULL);
                     ast_party_connected_line_free(&ast_connected);
                  }
                  ast_channel_unlock(p->owner);
               }
               sig_ss7_queue_control(linkset, chanpos, AST_CONTROL_RINGING);
               break;
            case CPG_EVENT_PROGRESS:
            case CPG_EVENT_INBANDINFO:
               {
                  ast_debug(1, "Queuing frame PROGRESS on CIC %d\n", p->cic);
                  sig_ss7_queue_control(linkset, chanpos, AST_CONTROL_PROGRESS);
                  p->progress = 1;
                  sig_ss7_set_dialing(p, 0);
                  sig_ss7_open_media(p);
               }
               break;
            default:
               ast_debug(1, "Do not handle CPG with event type 0x%x\n", e->cpg.event);
               break;
            }

            sig_ss7_unlock_private(p);
            break;
         case ISUP_EVENT_RSC:
            ast_verb(1, "Resetting CIC %d\n", e->rsc.cic);
            chanpos = ss7_find_cic_gripe(linkset, e->rsc.cic, e->rsc.opc, "RSC");
            if (chanpos < 0) {
               isup_free_call(ss7, e->rsc.call);
               break;
            }
            p = linkset->pvts[chanpos];
            sig_ss7_lock_private(p);
            p->ss7call = e->rsc.call;
            callid = func_ss7_linkset_callid(linkset, chanpos);
            sig_ss7_set_inservice(p, 1);
            sig_ss7_set_remotelyblocked(p, 0, SS7_BLOCKED_MAINTENANCE | SS7_BLOCKED_HARDWARE);

            if (p->locallyblocked & SS7_BLOCKED_MAINTENANCE) {
               isup_blo(ss7, e->rsc.call);
            } else if (p->locallyblocked & SS7_BLOCKED_HARDWARE) {
               sig_ss7_set_locallyblocked(p, 0, SS7_BLOCKED_HARDWARE);
            }

            isup_set_call_dpc(e->rsc.call, p->dpc);
            sig_ss7_lock_owner(linkset, chanpos);
            if (p->owner) {
               p->do_hangup = SS7_HANGUP_SEND_RLC;
               if (!(e->rsc.got_sent_msg & ISUP_SENT_IAM)) {
                  /* Q.784 6.2.3 */
                  ast_channel_hangupcause_set(p->owner, AST_CAUSE_NORMAL_CLEARING);
               } else {
                  ast_channel_hangupcause_set(p->owner, SS7_CAUSE_TRY_AGAIN);
               }

               ss7_queue_pvt_cause_data(p->owner, "SS7 ISUP_EVENT_RSC", AST_CAUSE_INTERWORKING);

               ast_softhangup_nolock(p->owner, AST_SOFTHANGUP_DEV);
               ast_channel_unlock(p->owner);
            } else {
               isup_rlc(ss7, e->rsc.call);
               p->ss7call = isup_free_call_if_clear(ss7, e->rsc.call);
            }
            /* End the loopback if we have one */
            sig_ss7_loopback(p, 0);

            sig_ss7_unlock_private(p);
            break;
         case ISUP_EVENT_GRS:
            if (!sig_ss7_find_cic_range(linkset, e->grs.startcic, e->grs.endcic,
               e->grs.opc)) {
               ast_log(LOG_WARNING, "GRS on unconfigured range CIC %d - %d PC %d\n",
                  e->grs.startcic, e->grs.endcic, e->grs.opc);
               chanpos = sig_ss7_find_cic(linkset, e->grs.startcic, e->grs.opc);
               if (chanpos < 0) {
                  isup_free_call(ss7, e->grs.call);
                  break;
               }
               p = linkset->pvts[chanpos];
               sig_ss7_lock_private(p);
               p->ss7call = isup_free_call_if_clear(ss7, e->grs.call);
               sig_ss7_unlock_private(p);
               break;
            }

            /* Leave startcic last to collect all cics mb_state */
            for (i = e->grs.endcic - e->grs.startcic; 0 <= i; --i) {
               /*
                * We are guaranteed to find chanpos because
                * sig_ss7_find_cic_range() includes it.
                */
               chanpos = sig_ss7_find_cic(linkset, e->grs.startcic + i, e->grs.opc);
               p = linkset->pvts[chanpos];
               sig_ss7_lock_private(p);

               if (p->locallyblocked & SS7_BLOCKED_MAINTENANCE) {
                  mb_state[i] = 1;
               } else {
                  mb_state[i] = 0;
                  sig_ss7_set_locallyblocked(p, 0, SS7_BLOCKED_HARDWARE);
               }

               sig_ss7_set_remotelyblocked(p, 0, SS7_BLOCKED_MAINTENANCE | SS7_BLOCKED_HARDWARE);

               if (!i) {
                  p->ss7call = e->grs.call;
                  isup_gra(ss7, p->ss7call, e->grs.endcic, mb_state);
               }

               sig_ss7_lock_owner(linkset, chanpos);
               if (p->owner) {
                  ast_channel_softhangup_internal_flag_add(p->owner, AST_SOFTHANGUP_DEV);
                  if (ast_channel_state(p->owner) == AST_STATE_DIALING
                     && linkset->pvts[i]->call_level < SIG_SS7_CALL_LEVEL_PROCEEDING) {
                     ast_channel_hangupcause_set(p->owner, SS7_CAUSE_TRY_AGAIN);
                  } else {
                     ast_channel_hangupcause_set(p->owner, AST_CAUSE_NORMAL_CLEARING);
                  }
                  p->do_hangup = SS7_HANGUP_FREE_CALL;
                  ast_channel_unlock(p->owner);
               } else if (!i) {
                  p->ss7call = isup_free_call_if_clear(ss7, p->ss7call);
               } else if (p->ss7call) {
                  /* clear any other session */
                  isup_free_call(ss7, p->ss7call);
                  p->ss7call = NULL;
               }
               sig_ss7_set_inservice(p, 1);
               sig_ss7_unlock_private(p);
            }
            break;
         case ISUP_EVENT_CQM:
            ast_debug(1, "Got Circuit group query message from CICs %d to %d\n",
                     e->cqm.startcic, e->cqm.endcic);
            ss7_handle_cqm(linkset, e);
            break;
         case ISUP_EVENT_GRA:
            if (!sig_ss7_find_cic_range(linkset, e->gra.startcic,
                     e->gra.endcic, e->gra.opc)) { /* Never will be true */
               ast_log(LOG_WARNING, "GRA on unconfigured range CIC %d - %d PC %d\n",
                     e->gra.startcic, e->gra.endcic, e->gra.opc);
               isup_free_call(ss7, e->gra.call);
               break;
            }
            ast_verb(1, "Got reset acknowledgement from CIC %d to %d DPC: %d\n",
               e->gra.startcic, e->gra.endcic, e->gra.opc);
            ss7_block_cics(linkset, e->gra.startcic, e->gra.endcic, e->gra.opc,
               e->gra.status, 1, 1, SS7_BLOCKED_MAINTENANCE);
            ss7_inservice(linkset, e->gra.startcic, e->gra.endcic, e->gra.opc);

            chanpos = sig_ss7_find_cic(linkset, e->gra.startcic, e->gra.opc);
            if (chanpos < 0) {
               isup_free_call(ss7, e->gra.call);
               break;
            }

            p = linkset->pvts[chanpos];
            sig_ss7_lock_private(p);

            /* we may send a CBD with GRS! */
            p->ss7call = isup_free_call_if_clear(ss7, e->gra.call);
            sig_ss7_unlock_private(p);
            break;
         case ISUP_EVENT_SAM:
            chanpos = ss7_find_cic_gripe(linkset, e->sam.cic, e->sam.opc, "SAM");
            if (chanpos < 0) {
               isup_free_call(ss7, e->sam.call);
               break;
            }
            p = linkset->pvts[chanpos];
            sig_ss7_lock_private(p);
            sig_ss7_lock_owner(linkset, chanpos);
            if (p->owner) {
               ast_log(LOG_WARNING, "SAM on CIC %d PC %d already have call\n", e->sam.cic, e->sam.opc);
               ast_channel_unlock(p->owner);
               sig_ss7_unlock_private(p);
               break;
            }
            p->called_complete = 0;
            if (!ast_strlen_zero(e->sam.called_party_num)) {
               char *st;
               strncat(p->exten, e->sam.called_party_num, sizeof(p->exten) - strlen(p->exten) - 1);
               st = strchr(p->exten, '#');
               if (st) {
                  *st = '\0';
                  p->called_complete = 1;
               }
               ss7_match_extension(linkset, p, e);
            }
            sig_ss7_unlock_private(p);
            break;
         case ISUP_EVENT_IAM:
            ast_debug(1, "Got IAM for CIC %d and called number %s, calling number %s\n", e->iam.cic, e->iam.called_party_num, e->iam.calling_party_num);
            chanpos = ss7_find_cic_gripe(linkset, e->iam.cic, e->iam.opc, "IAM");
            if (chanpos < 0) {
               isup_free_call(ss7, e->iam.call);
               break;
            }
            p = linkset->pvts[chanpos];
            sig_ss7_lock_private(p);
            /*
             * The channel should be idle and not have an owner at this point since we
             * are in the process of creating an owner for it.
             */
            ast_assert(!p->owner && p->call_level == SIG_SS7_CALL_LEVEL_IDLE);

            if (p->remotelyblocked) {
               ast_log(LOG_NOTICE, "Got IAM on remotely blocked CIC %d DPC %d remove blocking\n", e->iam.cic, e->iam.opc);
               sig_ss7_set_remotelyblocked(p, 0, SS7_BLOCKED_MAINTENANCE | SS7_BLOCKED_HARDWARE);
               sig_ss7_set_inservice(p, 1);
            }

            if (!sig_ss7_is_chan_available(p)) {
               /* Circuit is likely blocked or in alarm. */
               isup_rel(ss7, e->iam.call, AST_CAUSE_NORMAL_CIRCUIT_CONGESTION);
               if (p->locallyblocked) {
                  isup_clear_callflags(ss7, e->iam.call, ISUP_GOT_IAM);
                  p->ss7call = isup_free_call_if_clear(ss7, e->iam.call);
                  ast_log(LOG_WARNING, "Got IAM on locally blocked CIC %d DPC %d, ignore\n", e->iam.cic, e->iam.opc);
               }
               sig_ss7_unlock_private(p);
               break;
            }

            /* Mark channel as in use so no outgoing call will steal it. */
            p->call_level = SIG_SS7_CALL_LEVEL_ALLOCATED;
            p->ss7call = e->iam.call;

            isup_set_call_dpc(p->ss7call, p->dpc);

            if ((p->use_callerid) && (!ast_strlen_zero(e->iam.calling_party_num))) {
               ss7_apply_plan_to_number(p->cid_num, sizeof(p->cid_num), linkset, e->iam.calling_party_num, e->iam.calling_nai);
               p->callingpres = ss7_pres_scr2cid_pres(e->iam.presentation_ind, e->iam.screening_ind);
            } else {
               p->cid_num[0] = 0;
               if (e->iam.presentation_ind) {
                  p->callingpres = ss7_pres_scr2cid_pres(e->iam.presentation_ind, e->iam.screening_ind);
               }
            }

            p->called_complete = 0;
            if (p->immediate) {
               p->exten[0] = 's';
               p->exten[1] = '\0';
            } else if (!ast_strlen_zero(e->iam.called_party_num)) {
               char *st;
               ss7_apply_plan_to_number(p->exten, sizeof(p->exten), linkset, e->iam.called_party_num, e->iam.called_nai);
               st = strchr(p->exten, '#');
               if (st) {
                  *st = '\0';
                  p->called_complete = 1;
               }
            } else {
               p->exten[0] = '\0';
            }

            p->cid_ani[0] = '\0';
            if ((p->use_callerid) && (!ast_strlen_zero(e->iam.generic_name))) {
               ast_copy_string(p->cid_name, e->iam.generic_name, sizeof(p->cid_name));
            } else {
               p->cid_name[0] = '\0';
            }

            p->cid_ani2 = e->iam.oli_ani2;
            p->cid_ton = 0;
            ast_copy_string(p->charge_number, e->iam.charge_number, sizeof(p->charge_number));
            ast_copy_string(p->gen_add_number, e->iam.gen_add_number, sizeof(p->gen_add_number));
            p->gen_add_type = e->iam.gen_add_type;
            p->gen_add_nai = e->iam.gen_add_nai;
            p->gen_add_pres_ind = e->iam.gen_add_pres_ind;
            p->gen_add_num_plan = e->iam.gen_add_num_plan;
            ast_copy_string(p->gen_dig_number, e->iam.gen_dig_number, sizeof(p->gen_dig_number));
            p->gen_dig_type = e->iam.gen_dig_type;
            p->gen_dig_scheme = e->iam.gen_dig_scheme;
            ast_copy_string(p->jip_number, e->iam.jip_number, sizeof(p->jip_number));
            if (!ast_strlen_zero(e->iam.orig_called_num)) {
               ss7_apply_plan_to_number(p->orig_called_num, sizeof(p->orig_called_num), linkset, e->iam.orig_called_num, e->iam.orig_called_nai);
               p->orig_called_presentation = ss7_pres_scr2cid_pres(e->iam.orig_called_pres_ind, e->iam.orig_called_screening_ind);
            }
            if (!ast_strlen_zero(e->iam.redirecting_num)) {
               ss7_apply_plan_to_number(p->redirecting_num, sizeof(p->redirecting_num), linkset, e->iam.redirecting_num, e->iam.redirecting_num_nai);
               p->redirecting_presentation = ss7_pres_scr2cid_pres(e->iam.redirecting_num_presentation_ind, e->iam.redirecting_num_screening_ind);
            }
            ast_copy_string(p->generic_name, e->iam.generic_name, sizeof(p->generic_name));
            p->calling_party_cat = e->iam.calling_party_cat;
            p->redirect_counter = e->iam.redirect_counter;
            p->redirect_info = e->iam.redirect_info;
            p->redirect_info_ind = e->iam.redirect_info_ind;
            p->redirect_info_orig_reas = e->iam.redirect_info_orig_reas;
            p->redirect_info_counter = e->iam.redirect_info_counter;
            if (p->redirect_info_counter && !p->redirect_counter) {
               p->redirect_counter = p->redirect_info_counter;
            }
            p->redirect_info_reas = e->iam.redirect_info_reas;
            p->cug_indicator = e->iam.cug_indicator;
            p->cug_interlock_code = e->iam.cug_interlock_code;
            ast_copy_string(p->cug_interlock_ni, e->iam.cug_interlock_ni, sizeof(p->cug_interlock_ni));

            if (e->iam.cot_check_required) {
               sig_ss7_loopback(p, 1);
            }

            p->echocontrol_ind = e->iam.echocontrol_ind;
            sig_ss7_set_caller_id(p);
            ss7_match_extension(linkset, p, e);
            sig_ss7_unlock_private(p);

            if (e->iam.cot_performed_on_previous_cic) {
               chanpos = sig_ss7_find_cic(linkset, (e->iam.cic - 1), e->iam.opc);
               if (chanpos < 0) {
                  /* some stupid switch do this */
                  ast_verb(1, "COT request on previous nonexistent CIC %d in IAM PC %d\n", (e->iam.cic - 1), e->iam.opc);
                  break;
               }
               ast_verb(1, "COT request on previous CIC %d in IAM PC %d\n", (e->iam.cic - 1), e->iam.opc);
               p = linkset->pvts[chanpos];
               sig_ss7_lock_private(p);
               if (sig_ss7_is_chan_available(p)) {
                  sig_ss7_set_inservice(p, 0);  /* to prevent to use this circuit */
                  sig_ss7_loopback(p, 1);
               } /* If already have a call don't loop */
               sig_ss7_unlock_private(p);
            }
            break;
         case ISUP_EVENT_DIGITTIMEOUT:
            chanpos = ss7_find_cic_gripe(linkset, e->digittimeout.cic, e->digittimeout.opc, "DIGITTIMEOUT");
            if (chanpos < 0) {
               isup_free_call(ss7, e->digittimeout.call);
               break;
            }
            p = linkset->pvts[chanpos];
            sig_ss7_lock_private(p);
            ast_debug(1, "Digittimeout on CIC: %d PC: %d\n", e->digittimeout.cic, e->digittimeout.opc);
            if (ast_exists_extension(NULL, p->context, p->exten, 1, p->cid_num)) {
               /* DNID is complete */
               p->called_complete = 1;
               sig_ss7_set_dnid(p, p->exten);

               /* If COT successful start call! */
               if (!(e->digittimeout.cot_check_required || e->digittimeout.cot_performed_on_previous_cic) || e->digittimeout.cot_check_passed) {
                  ss7_start_call(p, linkset);
               }
            } else {
               ast_debug(1, "Call on CIC for unconfigured extension %s\n", p->exten);
               isup_rel(linkset->ss7, e->digittimeout.call, AST_CAUSE_UNALLOCATED);
            }
            sig_ss7_unlock_private(p);
            break;
         case ISUP_EVENT_COT:
            if (e->cot.cot_performed_on_previous_cic) {
               chanpos = sig_ss7_find_cic(linkset, (e->cot.cic - 1), e->cot.opc);
               /* some stupid switches do this!!! */
               if (-1 < chanpos) {
                  p = linkset->pvts[chanpos];
                  sig_ss7_lock_private(p);
                  sig_ss7_set_inservice(p, 1);
                  sig_ss7_loopback(p, 0);
                  sig_ss7_unlock_private(p);;
                  ast_verb(1, "Loop turned off on CIC: %d PC: %d\n",  (e->cot.cic - 1), e->cot.opc);
               }
            }

            chanpos = ss7_find_cic_gripe(linkset, e->cot.cic, e->cot.opc, "COT");
            if (chanpos < 0) {
               isup_free_call(ss7, e->cot.call);
               break;
            }
            p = linkset->pvts[chanpos];

            sig_ss7_lock_private(p);
            p->ss7call = e->cot.call;

            if (p->loopedback) {
               sig_ss7_loopback(p, 0);
               ast_verb(1, "Loop turned off on CIC: %d PC: %d\n",  e->cot.cic, e->cot.opc);
            }

            /* Don't start call if we didn't get IAM or COT failed! */
            if ((e->cot.got_sent_msg & ISUP_GOT_IAM) && e->cot.passed && p->called_complete) {
               ss7_start_call(p, linkset);
            }

            p->ss7call = isup_free_call_if_clear(ss7, p->ss7call);
            sig_ss7_unlock_private(p);
            break;
         case ISUP_EVENT_CCR:
            ast_debug(1, "Got CCR request on CIC %d\n", e->ccr.cic);
            chanpos = ss7_find_cic_gripe(linkset, e->ccr.cic, e->ccr.opc, "CCR");
            if (chanpos < 0) {
               isup_free_call(ss7, e->ccr.call);
               break;
            }

            p = linkset->pvts[chanpos];

            sig_ss7_lock_private(p);
            p->ss7call = e->ccr.call;
            sig_ss7_loopback(p, 1);
            if (linkset->type == SS7_ANSI) {
               isup_lpa(linkset->ss7, e->ccr.cic, p->dpc);
            }
            sig_ss7_unlock_private(p);
            break;
         case ISUP_EVENT_CVT:
            ast_debug(1, "Got CVT request on CIC %d\n", e->cvt.cic);
            chanpos = ss7_find_cic_gripe(linkset, e->cvt.cic, e->cvt.opc, "CVT");
            if (chanpos < 0) {
               isup_free_call(ss7, e->cvt.call);
               break;
            }

            p = linkset->pvts[chanpos];

            sig_ss7_lock_private(p);
            p->ss7call = e->cvt.call;
            sig_ss7_loopback(p, 1);
            if (!p->owner) {
               p->ss7call = isup_free_call_if_clear(ss7, e->cvt.call);
            }
            isup_cvr(linkset->ss7, e->cvt.cic, p->dpc);
            sig_ss7_unlock_private(p);
            break;
         case ISUP_EVENT_REL:
            chanpos = ss7_find_cic_gripe(linkset, e->rel.cic, e->rel.opc, "REL");
            if (chanpos < 0) {
               isup_free_call(ss7, e->rel.call);
               break;
            }
            p = linkset->pvts[chanpos];
            sig_ss7_lock_private(p);
            p->ss7call = e->rel.call;
            callid = func_ss7_linkset_callid(linkset, chanpos);
            sig_ss7_lock_owner(linkset, chanpos);
            if (p->owner) {
               snprintf(cause_str, sizeof(cause_str), "SS7 ISUP_EVENT_REL (%d)", e->rel.cause);
               ss7_queue_pvt_cause_data(p->owner, cause_str, e->rel.cause);

               ast_channel_hangupcause_set(p->owner, e->rel.cause);
               ast_softhangup_nolock(p->owner, AST_SOFTHANGUP_DEV);
               p->do_hangup = SS7_HANGUP_SEND_RLC;
               ast_channel_unlock(p->owner);
            } else {
               ast_verb(1, "REL on CIC %d DPC %d without owner!\n", p->cic, p->dpc);
               isup_rlc(ss7, p->ss7call);
               p->ss7call = isup_free_call_if_clear(ss7, p->ss7call);
            }

            /* End the loopback if we have one */
            sig_ss7_loopback(p, 0);

            /* the rel is not complete here!!! */
            sig_ss7_unlock_private(p);
            break;
         case ISUP_EVENT_ACM:
            chanpos = ss7_find_cic_gripe(linkset, e->acm.cic, e->acm.opc, "ACM");
            if (chanpos < 0) {
               isup_free_call(ss7, e->acm.call);
               break;
            }

            p = linkset->pvts[chanpos];

            ast_debug(1, "Queueing frame from SS7_EVENT_ACM on CIC %d\n", p->cic);

            if (e->acm.call_ref_ident > 0) {
               p->rlt = 1; /* Setting it but not using it here*/
            }

            sig_ss7_lock_private(p);
            p->ss7call = e->acm.call;
            callid = func_ss7_linkset_callid(linkset, chanpos);
            sig_ss7_queue_control(linkset, chanpos, AST_CONTROL_PROCEEDING);
            if (p->call_level < SIG_SS7_CALL_LEVEL_PROCEEDING) {
               p->call_level = SIG_SS7_CALL_LEVEL_PROCEEDING;
            }
            sig_ss7_set_dialing(p, 0);
            /* Send alerting if subscriber is free */
            if (e->acm.called_party_status_ind == 1) {
               if (p->call_level < SIG_SS7_CALL_LEVEL_ALERTING) {
                  p->call_level = SIG_SS7_CALL_LEVEL_ALERTING;
               }
               sig_ss7_lock_owner(linkset, chanpos);
               if (p->owner) {
                  ast_setstate(p->owner, AST_STATE_RINGING);
                  ast_channel_unlock(p->owner);
               }
               sig_ss7_queue_control(linkset, chanpos, AST_CONTROL_RINGING);
            }
            p->echocontrol_ind = e->acm.echocontrol_ind;
            sig_ss7_unlock_private(p);
            break;
         case ISUP_EVENT_CGB:
            chanpos = ss7_find_cic_gripe(linkset, e->cgb.startcic, e->cgb.opc, "CGB");
            if (chanpos < 0) {
               isup_free_call(ss7, e->cgb.call);
               break;
            }
            p = linkset->pvts[chanpos];
            ss7_check_range(linkset, e->cgb.startcic, e->cgb.endcic,
               e->cgb.opc, e->cgb.status);
            ss7_block_cics(linkset, e->cgb.startcic, e->cgb.endcic,
               e->cgb.opc, e->cgb.status, 1, 1,
               (e->cgb.type) ? SS7_BLOCKED_HARDWARE : SS7_BLOCKED_MAINTENANCE);

            sig_ss7_lock_private(p);
            p->ss7call = e->cgb.call;

            isup_cgba(linkset->ss7, p->ss7call, e->cgb.endcic, e->cgb.status);
            if (!p->owner) {
               p->ss7call = isup_free_call_if_clear(ss7, e->cgb.call);
            }
            sig_ss7_unlock_private(p);
            break;
         case ISUP_EVENT_CGU:
            chanpos = ss7_find_cic_gripe(linkset, e->cgu.startcic, e->cgu.opc, "CGU");
            if (chanpos < 0) {
               isup_free_call(ss7, e->cgu.call);
               break;
            }
            p = linkset->pvts[chanpos];
            ss7_check_range(linkset, e->cgu.startcic, e->cgu.endcic,
               e->cgu.opc, e->cgu.status);
            ss7_block_cics(linkset, e->cgu.startcic, e->cgu.endcic,
               e->cgu.opc, e->cgu.status, 0, 1,
               e->cgu.type ? SS7_BLOCKED_HARDWARE : SS7_BLOCKED_MAINTENANCE);

            sig_ss7_lock_private(p);
            p->ss7call = e->cgu.call;

            isup_cgua(linkset->ss7, p->ss7call, e->cgu.endcic, e->cgu.status);
            if (!p->owner) {
               p->ss7call = isup_free_call_if_clear(ss7, e->cgu.call);
            }
            sig_ss7_unlock_private(p);
            break;
         case ISUP_EVENT_UCIC:
            chanpos = ss7_find_cic_gripe(linkset, e->ucic.cic, e->ucic.opc, "UCIC");
            if (chanpos < 0) {
               isup_free_call(ss7, e->ucic.call);
               break;
            }
            p = linkset->pvts[chanpos];
            ast_debug(1, "Unequiped Circuit Id Code on CIC %d\n", e->ucic.cic);
            sig_ss7_lock_private(p);
            sig_ss7_lock_owner(linkset, chanpos);
            if (p->owner) {
               ast_softhangup_nolock(p->owner, AST_SOFTHANGUP_DEV);
               ast_channel_unlock(p->owner);
            }
            sig_ss7_set_remotelyblocked(p, 1, SS7_BLOCKED_MAINTENANCE);
            sig_ss7_set_inservice(p, 0);
            p->ss7call = NULL;
            isup_free_call(ss7, e->ucic.call);
            sig_ss7_unlock_private(p);/* doesn't require a SS7 acknowledgement */
            break;
         case ISUP_EVENT_BLO:
            chanpos = ss7_find_cic_gripe(linkset, e->blo.cic, e->blo.opc, "BLO");
            if (chanpos < 0) {
               isup_free_call(ss7, e->blo.call);
               break;
            }
            p = linkset->pvts[chanpos];
            ast_debug(1, "Blocking CIC %d\n", e->blo.cic);
            sig_ss7_lock_private(p);
            p->ss7call = e->blo.call;
            sig_ss7_set_remotelyblocked(p, 1, SS7_BLOCKED_MAINTENANCE);
            isup_bla(linkset->ss7, e->blo.call);
            sig_ss7_lock_owner(linkset, chanpos);
            if (!p->owner) {
               p->ss7call = isup_free_call_if_clear(ss7, e->blo.call);
            } else {
               if (e->blo.got_sent_msg & ISUP_SENT_IAM) {
                  /* Q.784 6.2.2 */
                  ast_channel_hangupcause_set(p->owner, SS7_CAUSE_TRY_AGAIN);
               }
               ast_channel_unlock(p->owner);
            }
            sig_ss7_unlock_private(p);
            break;
         case ISUP_EVENT_BLA:
            chanpos = ss7_find_cic_gripe(linkset, e->bla.cic, e->bla.opc, "BLA");
            if (chanpos < 0) {
               isup_free_call(ss7, e->bla.call);
               break;
            }
            ast_debug(1, "Locally blocking CIC %d\n", e->bla.cic);
            p = linkset->pvts[chanpos];
            sig_ss7_lock_private(p);
            p->ss7call = e->bla.call;
            sig_ss7_set_locallyblocked(p, 1, SS7_BLOCKED_MAINTENANCE);
            if (!p->owner) {
               p->ss7call = isup_free_call_if_clear(ss7, p->ss7call);
            }
            sig_ss7_unlock_private(p);
            break;
         case ISUP_EVENT_UBL:
            chanpos = ss7_find_cic_gripe(linkset, e->ubl.cic, e->ubl.opc, "UBL");
            if (chanpos < 0) {
               isup_free_call(ss7, e->ubl.call);
               break;
            }
            p = linkset->pvts[chanpos];
            ast_debug(1, "Remotely unblocking CIC %d PC %d\n", e->ubl.cic, e->ubl.opc);
            sig_ss7_lock_private(p);
            p->ss7call = e->ubl.call;
            sig_ss7_set_remotelyblocked(p, 0, SS7_BLOCKED_MAINTENANCE);
            isup_uba(linkset->ss7, e->ubl.call);
            if (!p->owner) {
               p->ss7call = isup_free_call_if_clear(ss7, p->ss7call);
            }
            sig_ss7_unlock_private(p);
            break;
         case ISUP_EVENT_UBA:
            chanpos = ss7_find_cic_gripe(linkset, e->uba.cic, e->uba.opc, "UBA");
            if (chanpos < 0) {
               isup_free_call(ss7, e->uba.call);
               break;
            }
            p = linkset->pvts[chanpos];
            ast_debug(1, "Locally unblocking CIC %d PC %d\n", e->uba.cic, e->uba.opc);
            sig_ss7_lock_private(p);
            p->ss7call = e->uba.call;
            sig_ss7_set_locallyblocked(p, 0, SS7_BLOCKED_MAINTENANCE);
            if (!p->owner) {
               p->ss7call = isup_free_call_if_clear(ss7, p->ss7call);
            }
            sig_ss7_unlock_private(p);
            break;
         case ISUP_EVENT_CON:
         case ISUP_EVENT_ANM:
            if (e->e == ISUP_EVENT_CON) {
               chanpos = ss7_find_cic_gripe(linkset, e->con.cic, e->con.opc, "CON");
               if (chanpos < 0) {
                  isup_free_call(ss7, e->con.call);
                  break;
               }
            } else {
               chanpos = ss7_find_cic_gripe(linkset, e->anm.cic, e->anm.opc, "ANM");
               if (chanpos < 0) {
                  isup_free_call(ss7, e->anm.call);
                  break;
               }
            }

            p = linkset->pvts[chanpos];
            sig_ss7_lock_private(p);
            p->ss7call = (e->e == ISUP_EVENT_ANM) ?  e->anm.call : e->con.call;
            callid = func_ss7_linkset_callid(linkset, chanpos);
            if (p->call_level < SIG_SS7_CALL_LEVEL_CONNECT) {
               p->call_level = SIG_SS7_CALL_LEVEL_CONNECT;
            }

            if (!ast_strlen_zero((e->e == ISUP_EVENT_ANM)
               ? e->anm.connected_num : e->con.connected_num)) {
               sig_ss7_lock_owner(linkset, chanpos);
               if (p->owner) {
                  struct ast_party_connected_line ast_connected;
                  char connected_num[AST_MAX_EXTENSION];

                  ast_party_connected_line_init(&ast_connected);
                  if (e->e == ISUP_EVENT_ANM) {
                     ast_connected.id.number.presentation = ss7_pres_scr2cid_pres(
                        e->anm.connected_presentation_ind,
                        e->anm.connected_screening_ind);
                     ss7_apply_plan_to_number(connected_num, sizeof(connected_num),
                        linkset, e->anm.connected_num, e->anm.connected_nai);
                     ast_connected.id.number.str = ast_strdup(connected_num);
                  } else {
                     ast_connected.id.number.presentation = ss7_pres_scr2cid_pres(
                        e->con.connected_presentation_ind,
                        e->con.connected_screening_ind);
                     ss7_apply_plan_to_number(connected_num, sizeof(connected_num),
                        linkset, e->con.connected_num, e->con.connected_nai);
                     ast_connected.id.number.str = ast_strdup(connected_num);
                  }
                  ast_connected.id.number.valid = 1;
                  ast_connected.source = AST_CONNECTED_LINE_UPDATE_SOURCE_ANSWER;
                  ast_channel_queue_connected_line_update(p->owner, &ast_connected, NULL);
                  ast_party_connected_line_free(&ast_connected);
                  ast_channel_unlock(p->owner);
               }
            }

            sig_ss7_queue_control(linkset, chanpos, AST_CONTROL_ANSWER);
            sig_ss7_set_dialing(p, 0);
            sig_ss7_open_media(p);
            if (((e->e == ISUP_EVENT_ANM) ? !e->anm.echocontrol_ind  :
                  !e->con.echocontrol_ind) || !(linkset->flags & LINKSET_FLAG_USEECHOCONTROL)) {
               sig_ss7_set_echocanceller(p, 1);
            }
            sig_ss7_unlock_private(p);
            break;
         case ISUP_EVENT_RLC:
            chanpos = ss7_find_cic_gripe(linkset, e->rlc.cic, e->rlc.opc, "RLC");
            if (chanpos < 0) {
               isup_free_call(ss7, e->rlc.call);
               break;
            }

            p = linkset->pvts[chanpos];
            sig_ss7_lock_private(p);
            p->ss7call = e->rlc.call;
            callid = func_ss7_linkset_callid(linkset, chanpos);
            if (e->rlc.got_sent_msg & (ISUP_SENT_RSC | ISUP_SENT_REL)) {
               sig_ss7_loopback(p, 0);
               if (e->rlc.got_sent_msg & ISUP_SENT_RSC) {
                  sig_ss7_set_inservice(p, 1);
               }
            }
            sig_ss7_lock_owner(linkset, chanpos);
            if (!p->owner) {
               p->ss7call = isup_free_call_if_clear(ss7, e->rlc.call);
               p->call_level = SIG_SS7_CALL_LEVEL_IDLE;
            } else {
               p->do_hangup = SS7_HANGUP_DO_NOTHING;
               ast_softhangup_nolock(p->owner, AST_SOFTHANGUP_DEV);
               ast_channel_unlock(p->owner);
            }
            sig_ss7_unlock_private(p);
            break;
         case ISUP_EVENT_FAA:
            /*!
             * \todo The handling of the SS7 FAA message is not good and I
             * don't know enough to handle it correctly.
             */
            chanpos = ss7_find_cic_gripe(linkset, e->faa.cic, e->faa.opc, "FAA");
            if (chanpos < 0) {
               isup_free_call(ss7, e->faa.call);
               break;
            }

            /* XXX FAR and FAA used for something dealing with transfers? */
            p = linkset->pvts[chanpos];
            sig_ss7_lock_private(p);
            callid = func_ss7_linkset_callid(linkset, chanpos);
            ast_debug(1, "FAA received on CIC %d\n", e->faa.cic);
            p->ss7call = isup_free_call_if_clear(ss7, e->faa.call);
            sig_ss7_unlock_private(p);
            break;
         case ISUP_EVENT_CGBA:
            chanpos = ss7_find_cic_gripe(linkset, e->cgba.startcic, e->cgba.opc, "CGBA");
            if (chanpos < 0) {   /* Never will be true */
               isup_free_call(ss7, e->cgba.call);
               break;
            }

            ss7_block_cics(linkset, e->cgba.startcic, e->cgba.endcic,
               e->cgba.opc, e->cgba.status, 1, 0,
               e->cgba.type ? SS7_BLOCKED_HARDWARE : SS7_BLOCKED_MAINTENANCE);

            p = linkset->pvts[chanpos];
            sig_ss7_lock_private(p);
            p->ss7call = e->cgba.call;

            if (!p->owner) {
               p->ss7call = isup_free_call_if_clear(ss7, p->ss7call);
            }
            sig_ss7_unlock_private(p);
            break;
         case ISUP_EVENT_CGUA:
            chanpos = ss7_find_cic_gripe(linkset, e->cgua.startcic, e->cgua.opc, "CGUA");
            if (chanpos < 0) { /* Never will be true */
               isup_free_call(ss7, e->cgua.call);
               break;
            }

            ss7_block_cics(linkset, e->cgua.startcic, e->cgua.endcic,
               e->cgua.opc, e->cgua.status, 0, 0,
               e->cgba.type ? SS7_BLOCKED_HARDWARE : SS7_BLOCKED_MAINTENANCE);

            p = linkset->pvts[chanpos];
            sig_ss7_lock_private(p);
            p->ss7call = e->cgua.call;

            if (!p->owner) {
               p->ss7call = isup_free_call_if_clear(ss7, p->ss7call);
            }
            sig_ss7_unlock_private(p);
            break;
         case ISUP_EVENT_SUS:
            chanpos = ss7_find_cic_gripe(linkset, e->sus.cic, e->sus.opc, "SUS");
            if (chanpos < 0) {
               isup_free_call(ss7, e->sus.call);
               break;
            }

            p = linkset->pvts[chanpos];
            sig_ss7_lock_private(p);
            p->ss7call = e->sus.call;
            if (!p->owner) {
               p->ss7call = isup_free_call_if_clear(ss7, p->ss7call);
            }
            sig_ss7_unlock_private(p);
            break;
         case ISUP_EVENT_RES:
            chanpos = ss7_find_cic_gripe(linkset, e->res.cic, e->res.opc, "RES");
            if (chanpos < 0) {
               isup_free_call(ss7, e->res.call);
               break;
            }

            p = linkset->pvts[chanpos];
            sig_ss7_lock_private(p);
            p->ss7call = e->res.call;
            if (!p->owner) {
               p->ss7call = isup_free_call_if_clear(ss7, p->ss7call);
            }
            sig_ss7_unlock_private(p);
            break;
         default:
            ast_debug(1, "Unknown event %s\n", ss7_event2str(e->e));
            break;
         }

         /* Call ID stuff needs to be cleaned up here */
         if (callid) {
            ast_callid_threadassoc_remove();
         }
      }
      ast_mutex_unlock(&linkset->lock);
   }

   return 0;
}

static void ss7_rel(struct sig_ss7_linkset *ss7)
{
   /* Release the lock first */
   ast_mutex_unlock(&ss7->lock);

   /* Then break the poll to send our messages */
   if (ss7->master != AST_PTHREADT_NULL) {
      pthread_kill(ss7->master, SIGURG);
   }
}

static void ss7_grab(struct sig_ss7_chan *pvt, struct sig_ss7_linkset *ss7)
{
   /* Grab the lock first */
   while (ast_mutex_trylock(&ss7->lock)) {
      /* Avoid deadlock */
      sig_ss7_deadlock_avoidance_private(pvt);
   }
}

/*!
 * \brief Reset a specific CIC.
 * \since 11.0
 *
 * \param linkset linkset control structure.
 * \param cic Circuit Identification Code
 * \param dpc Destination Point Code
 *
 * \return TRUE on success
 */
int sig_ss7_reset_cic(struct sig_ss7_linkset *linkset, int cic, unsigned int dpc)
{
   int i;

   ast_mutex_lock(&linkset->lock);
   for (i = 0; i < linkset->numchans; i++) {
      if (linkset->pvts[i] && linkset->pvts[i]->cic == cic && linkset->pvts[i]->dpc == dpc) {
         int res;

         sig_ss7_lock_private(linkset->pvts[i]);
         sig_ss7_set_locallyblocked(linkset->pvts[i], 0, SS7_BLOCKED_MAINTENANCE | SS7_BLOCKED_HARDWARE);
         res = ss7_start_rsc(linkset, i);
         sig_ss7_unlock_private(linkset->pvts[i]);
         ss7_rel(linkset); /* Also breaks the poll to send our messages */
         return res;
      }
   }
   ss7_rel(linkset);

   return 0;
}

/*!
 * \brief Block or Unblock a specific CIC.
 * \since 11.0
 *
 * \param linkset linkset control structure.
 * \param do_block Action to perform. Block if TRUE.
 * \param which On which CIC to perform the operation.
 *
 * \return 0 on success
 */
int sig_ss7_cic_blocking(struct sig_ss7_linkset *linkset, int do_block, int which)
{
   ast_mutex_lock(&linkset->lock);
   sig_ss7_lock_private(linkset->pvts[which]);
   if (!ss7_find_alloc_call(linkset->pvts[which])) {
      sig_ss7_unlock_private(linkset->pvts[which]);
      ss7_rel(linkset);
      return -1;
   }

   if (do_block) {
      isup_blo(linkset->ss7, linkset->pvts[which]->ss7call);
   } else {
      isup_ubl(linkset->ss7, linkset->pvts[which]->ss7call);
   }

   sig_ss7_unlock_private(linkset->pvts[which]);
   ss7_rel(linkset); /* Also breaks the poll to send our messages */

   return 0;
}

/*!
 * \brief Block or Unblock a range of CICs.
 * \since 11.0
 *
 * \param linkset linkset control structure.
 * \param do_block Action to perform. Block if TRUE.
 * \param chanpos Channel position to start from.
 * \param endcic Circuit Identification Code of the end of the range.
 * \param state Array of CIC blocking status.
 * \param type Type of the blocking - maintenance or hardware
 *
 * \note Assumes the linkset->lock is already obtained.
 *
 * \return 0 on success
 */
int sig_ss7_group_blocking(struct sig_ss7_linkset *linkset, int do_block, int chanpos, int endcic, unsigned char state[], int type)
{
   sig_ss7_lock_private(linkset->pvts[chanpos]);
   if (!ss7_find_alloc_call(linkset->pvts[chanpos])) {
      sig_ss7_unlock_private(linkset->pvts[chanpos]);
      return -1;
   }

   if (do_block) {
      isup_cgb(linkset->ss7, linkset->pvts[chanpos]->ss7call, endcic, state, type);
   } else {
      isup_cgu(linkset->ss7, linkset->pvts[chanpos]->ss7call, endcic, state, type);
   }

   sig_ss7_unlock_private(linkset->pvts[chanpos]);
   return 0;
}

/*!
 * \brief Reset a group of CICs.
 * \since 11.0
 *
 * \param linkset linkset control structure.
 * \param cic Circuit Identification Code
 * \param dpc Destination Point Code
 * \param range Range of the CICs to reset
 *
 * \note Assumes the linkset->lock is already obtained.
 *
 * \return 0 on success
 */
int sig_ss7_reset_group(struct sig_ss7_linkset *linkset, int cic, unsigned int dpc, int range)
{
   int i;

   for (i = 0; i < linkset->numchans; i++) {
      if (linkset->pvts[i] && linkset->pvts[i]->cic == cic && linkset->pvts[i]->dpc == dpc) {
         ss7_clear_channels(linkset, cic, cic + range, dpc, SS7_HANGUP_FREE_CALL);
         ss7_block_cics(linkset, cic, cic + range, dpc, NULL, 0, 1,
            SS7_BLOCKED_MAINTENANCE | SS7_BLOCKED_HARDWARE);
         ss7_block_cics(linkset, cic, cic + range, dpc, NULL, 0, 0,
            SS7_BLOCKED_MAINTENANCE | SS7_BLOCKED_HARDWARE);

         sig_ss7_lock_private(linkset->pvts[i]);
         if (!ss7_find_alloc_call(linkset->pvts[i])) {
            sig_ss7_unlock_private(linkset->pvts[i]);
            return -1;
         }
         isup_grs(linkset->ss7, linkset->pvts[i]->ss7call, linkset->pvts[i]->cic + range);
         sig_ss7_unlock_private(linkset->pvts[i]);
         break;
      }
   }
   return 0;
}

void sig_ss7_free_isup_call(struct sig_ss7_linkset *linkset, int channel)
{
   sig_ss7_lock_private(linkset->pvts[channel]);
   if (linkset->pvts[channel]->ss7call) {
      isup_free_call(linkset->ss7, linkset->pvts[channel]->ss7call);
      linkset->pvts[channel]->ss7call = NULL;
   }
   sig_ss7_unlock_private(linkset->pvts[channel]);
}

static int ss7_parse_prefix(struct sig_ss7_chan *p, const char *number, char *nai)
{
   int strip = 0;

   if (strncmp(number, p->ss7->internationalprefix, strlen(p->ss7->internationalprefix)) == 0) {
      strip = strlen(p->ss7->internationalprefix);
      *nai = SS7_NAI_INTERNATIONAL;
   } else if (strncmp(number, p->ss7->nationalprefix, strlen(p->ss7->nationalprefix)) == 0) {
      strip = strlen(p->ss7->nationalprefix);
      *nai = SS7_NAI_NATIONAL;
   } else if (strncmp(number, p->ss7->networkroutedprefix, strlen(p->ss7->networkroutedprefix)) == 0) {
      strip = strlen(p->ss7->networkroutedprefix);
      *nai = SS7_NAI_NETWORKROUTED;
   } else if (strncmp(number, p->ss7->unknownprefix, strlen(p->ss7->unknownprefix)) == 0) {
      strip = strlen(p->ss7->unknownprefix);
      *nai = SS7_NAI_UNKNOWN;
   } else if (strncmp(number, p->ss7->subscriberprefix, strlen(p->ss7->subscriberprefix)) == 0) {
      strip = strlen(p->ss7->subscriberprefix);
      *nai = SS7_NAI_SUBSCRIBER;
   } else {
      *nai = SS7_NAI_SUBSCRIBER;
   }

   return strip;
}

/*!
 * \brief Notify the SS7 layer that the link is in alarm.
 * \since 1.8
 *
 * \param linkset Controlling linkset for the channel.
 * \param which Link index of the signaling channel.
 *
 * \return Nothing
 */
void sig_ss7_link_alarm(struct sig_ss7_linkset *linkset, int which)
{
   linkset->linkstate[which] |= (LINKSTATE_DOWN | LINKSTATE_INALARM);
   linkset->linkstate[which] &= ~LINKSTATE_UP;
   ss7_link_alarm(linkset->ss7, linkset->fds[which]);
}

/*!
 * \brief Notify the SS7 layer that the link is no longer in alarm.
 * \since 1.8
 *
 * \param linkset Controlling linkset for the channel.
 * \param which Link index of the signaling channel.
 *
 * \return Nothing
 */
void sig_ss7_link_noalarm(struct sig_ss7_linkset *linkset, int which)
{
   linkset->linkstate[which] &= ~(LINKSTATE_INALARM | LINKSTATE_DOWN);
   linkset->linkstate[which] |= LINKSTATE_STARTING;
   ss7_link_noalarm(linkset->ss7, linkset->fds[which]);
}

/*!
 * \brief Setup and add a SS7 link channel.
 * \since 1.8
 *
 * \param linkset Controlling linkset for the channel.
 * \param which Link index of the signaling channel.
 * \param ss7type Switch type of the linkset
 * \param transport Signaling transport of channel.
 * \param inalarm Non-zero if the channel is in alarm.
 * \param networkindicator User configuration parameter.
 * \param pointcode User configuration parameter.
 * \param adjpointcode User configuration parameter.
 *
 * \retval 0 on success.
 * \retval -1 on error.
 */
int sig_ss7_add_sigchan(struct sig_ss7_linkset *linkset, int which, int ss7type, int transport, int inalarm, int networkindicator, int pointcode, int adjpointcode, int cur_slc)
{
   if (!linkset->ss7) {
      linkset->type = ss7type;
      linkset->ss7 = ss7_new(ss7type);
      if (!linkset->ss7) {
         ast_log(LOG_ERROR, "Can't create new SS7!\n");
         return -1;
      }
   }

   ss7_set_network_ind(linkset->ss7, networkindicator);
   ss7_set_pc(linkset->ss7, pointcode);

   if (ss7_add_link(linkset->ss7, transport, linkset->fds[which], cur_slc, adjpointcode)) {
      ast_log(LOG_WARNING, "Could not add SS7 link!\n");
   }

   if (inalarm) {
      linkset->linkstate[which] = LINKSTATE_DOWN | LINKSTATE_INALARM;
      ss7_link_alarm(linkset->ss7, linkset->fds[which]);
   } else {
      linkset->linkstate[which] = LINKSTATE_DOWN;
      ss7_link_noalarm(linkset->ss7, linkset->fds[which]);
   }

   return 0;
}

/*!
 * \brief Determine if the specified channel is available for an outgoing call.
 * \since 1.8
 *
 * \param p Signaling private structure pointer.
 *
 * \retval TRUE if the channel is available.
 */
int sig_ss7_available(struct sig_ss7_chan *p)
{
   int available;

   if (!p->ss7) {
      /* Something is wrong here.  A SS7 channel without the ss7 pointer? */
      return 0;
   }

   /* Only have to deal with the linkset lock. */
   ast_mutex_lock(&p->ss7->lock);
   available = sig_ss7_is_chan_available(p);
   if (available) {
      p->ss7call = isup_new_call(p->ss7->ss7, p->cic, p->dpc, 1);
      if (!p->ss7call) {
         ast_log(LOG_ERROR, "Unable to allocate new SS7 call!\n");
         available = 0;
      } else {
         p->call_level = SIG_SS7_CALL_LEVEL_ALLOCATED;
      }
   }
   ast_mutex_unlock(&p->ss7->lock);

   return available;
}

static unsigned char cid_pres2ss7pres(int cid_pres)
{
    return (cid_pres >> 5) & 0x03;
}

static unsigned char cid_pres2ss7screen(int cid_pres)
{
   return cid_pres & 0x03;
}

static void ss7_connected_line_update(struct sig_ss7_chan *p, struct ast_party_connected_line *connected)
{
   int connected_strip = 0;
   char connected_nai;
   unsigned char connected_pres;
   unsigned char connected_screen;
   const char *connected_num;

   if (!connected->id.number.valid) {
      return;
   }

   connected_num = S_OR(connected->id.number.str, "");
   if (p->ss7->called_nai ==  SS7_NAI_DYNAMIC) {
      connected_strip = ss7_parse_prefix(p, connected_num, &connected_nai);
   } else {
      connected_nai = p->ss7->called_nai;
   }

   connected_pres = cid_pres2ss7pres(connected->id.number.presentation);
   connected_screen = cid_pres2ss7screen(connected->id.number.presentation);

   isup_set_connected(p->ss7call, connected_num + connected_strip, connected_nai, connected_pres, connected_screen);
}

static unsigned char ss7_redirect_reason(struct sig_ss7_chan *p, struct ast_party_redirecting *redirecting, int orig)
{
   int reason = (orig) ? redirecting->orig_reason.code : redirecting->reason.code;

   switch (reason) {
   case AST_REDIRECTING_REASON_USER_BUSY:
      return SS7_REDIRECTING_REASON_USER_BUSY;
   case AST_REDIRECTING_REASON_NO_ANSWER:
      return SS7_REDIRECTING_REASON_NO_ANSWER;
   case AST_REDIRECTING_REASON_UNCONDITIONAL:
      return SS7_REDIRECTING_REASON_UNCONDITIONAL;
   }

   if (orig || reason == AST_REDIRECTING_REASON_UNKNOWN) {
      return SS7_REDIRECTING_REASON_UNKNOWN;
   }

   if (reason == AST_REDIRECTING_REASON_UNAVAILABLE) {
      return SS7_REDIRECTING_REASON_UNAVAILABLE;
   }

   if (reason == AST_REDIRECTING_REASON_DEFLECTION) {
      if (p->call_level > SIG_SS7_CALL_LEVEL_PROCEEDING) {
         return SS7_REDIRECTING_REASON_DEFLECTION_DURING_ALERTING;
      }
      return SS7_REDIRECTING_REASON_DEFLECTION_IMMEDIATE_RESPONSE;
   }

   return SS7_REDIRECTING_REASON_UNKNOWN;
}

static unsigned char ss7_redirect_info_ind(struct ast_channel *ast)
{
   const char *redirect_info_ind;
   struct ast_party_redirecting *redirecting = ast_channel_redirecting(ast);

   redirect_info_ind = pbx_builtin_getvar_helper(ast, "SS7_REDIRECT_INFO_IND");
   if (!ast_strlen_zero(redirect_info_ind)) {
      if (!strcasecmp(redirect_info_ind, "CALL_REROUTED_PRES_ALLOWED")) {
         return SS7_INDICATION_REROUTED_PRES_ALLOWED;
      }
      if (!strcasecmp(redirect_info_ind, "CALL_REROUTED_INFO_RESTRICTED")) {
         return SS7_INDICATION_REROUTED_INFO_RESTRICTED;
      }
      if (!strcasecmp(redirect_info_ind, "CALL_DIVERTED_PRES_ALLOWED")) {
         return SS7_INDICATION_DIVERTED_PRES_ALLOWED;
      }
      if (!strcasecmp(redirect_info_ind, "CALL_DIVERTED_INFO_RESTRICTED")) {
         return SS7_INDICATION_DIVERTED_INFO_RESTRICTED;
      }
      if (!strcasecmp(redirect_info_ind, "CALL_REROUTED_PRES_RESTRICTED")) {
         return SS7_INDICATION_REROUTED_PRES_RESTRICTED;
      }
      if (!strcasecmp(redirect_info_ind, "CALL_DIVERTED_PRES_RESTRICTED")) {
         return SS7_INDICATION_DIVERTED_PRES_RESTRICTED;
      }
      if (!strcasecmp(redirect_info_ind, "SPARE")) {
         return SS7_INDICATION_SPARE;
      }
      return SS7_INDICATION_NO_REDIRECTION;
   }

   if (redirecting->reason.code == AST_REDIRECTING_REASON_DEFLECTION) {
      if ((redirecting->to.number.presentation & AST_PRES_RESTRICTION) == AST_PRES_ALLOWED) {
         if ((redirecting->orig.number.presentation & AST_PRES_RESTRICTION) == AST_PRES_ALLOWED) {
            return SS7_INDICATION_DIVERTED_PRES_ALLOWED;
         }
         return SS7_INDICATION_DIVERTED_PRES_RESTRICTED;
      }
      return SS7_INDICATION_DIVERTED_INFO_RESTRICTED;
   }

   if ((redirecting->to.number.presentation & AST_PRES_RESTRICTION) == AST_PRES_ALLOWED) {
      if ((redirecting->orig.number.presentation & AST_PRES_RESTRICTION) == AST_PRES_ALLOWED) {
         return SS7_INDICATION_REROUTED_PRES_ALLOWED;
      }
      return SS7_INDICATION_REROUTED_PRES_RESTRICTED;
   }
   return SS7_INDICATION_REROUTED_INFO_RESTRICTED;
}

static void ss7_redirecting_update(struct sig_ss7_chan *p, struct ast_channel *ast)
{
   int num_nai_strip = 0;
   struct ast_party_redirecting *redirecting = ast_channel_redirecting(ast);

   if (!redirecting->count) {
      return;
   }

   isup_set_redirect_counter(p->ss7call, redirecting->count);

   if (redirecting->orig.number.valid) {
      char ss7_orig_called_nai = p->ss7->called_nai;
      const char *ss7_orig_called_num = S_OR(redirecting->orig.number.str, "");

      if (ss7_orig_called_nai == SS7_NAI_DYNAMIC) {
         num_nai_strip = ss7_parse_prefix(p, ss7_orig_called_num, &ss7_orig_called_nai);
      } else {
         num_nai_strip = 0;
      }
      isup_set_orig_called_num(p->ss7call, ss7_orig_called_num + num_nai_strip,
         ss7_orig_called_nai,
         cid_pres2ss7pres(redirecting->orig.number.presentation),
         cid_pres2ss7screen(redirecting->orig.number.presentation));
   }

   if (redirecting->from.number.valid) {
      char ss7_redirecting_num_nai = p->ss7->calling_nai;
      const char *redirecting_number = S_OR(redirecting->from.number.str, "");

      if (ss7_redirecting_num_nai == SS7_NAI_DYNAMIC) {
         num_nai_strip = ss7_parse_prefix(p, redirecting_number, &ss7_redirecting_num_nai);
      } else {
         num_nai_strip = 0;
      }

      isup_set_redirecting_number(p->ss7call, redirecting_number + num_nai_strip,
         ss7_redirecting_num_nai,
         cid_pres2ss7pres(redirecting->from.number.presentation),
         cid_pres2ss7screen(redirecting->from.number.presentation));
   }

   isup_set_redirection_info(p->ss7call, ss7_redirect_info_ind(ast),
      ss7_redirect_reason(p, ast_channel_redirecting(ast), 1),
      redirecting->count, ss7_redirect_reason(p, ast_channel_redirecting(ast), 0));
}

/*!
 * \brief Dial out using the specified SS7 channel.
 * \since 1.8
 *
 * \param p Signaling private structure pointer.
 * \param ast Asterisk channel structure pointer.
 * \param rdest Dialstring.
 *
 * \retval 0 on success.
 * \retval -1 on error.
 */
int sig_ss7_call(struct sig_ss7_chan *p, struct ast_channel *ast, const char *rdest)
{
   char ss7_called_nai;
   int called_nai_strip;
   char ss7_calling_nai;
   int calling_nai_strip;
   const char *col_req = NULL;
   const char *ss7_cug_indicator_str;
   const char *ss7_cug_interlock_ni;
   const char *ss7_cug_interlock_code;
   const char *ss7_interworking_indicator;
   const char *ss7_forward_indicator_pmbits;
   unsigned char ss7_cug_indicator;
   const char *charge_str = NULL;
   const char *gen_address = NULL;
   const char *gen_digits = NULL;
   const char *gen_dig_type = NULL;
   const char *gen_dig_scheme = NULL;
   const char *gen_name = NULL;
   const char *jip_digits = NULL;
   const char *lspi_ident = NULL;
   const char *rlt_flag = NULL;
   const char *call_ref_id = NULL;
   const char *call_ref_pc = NULL;
   const char *send_far = NULL;
   const char *tmr = NULL;
   char *c;
   char *l;
   char dest[256];

   ast_copy_string(dest, rdest, sizeof(dest));

   c = strchr(dest, '/');
   if (c) {
      c++;
   } else {
      c = "";
   }
   if (strlen(c) < p->stripmsd) {
      ast_log(LOG_WARNING, "Number '%s' is shorter than stripmsd (%d)\n", c, p->stripmsd);
      return -1;
   }

   if (!p->hidecallerid) {
      l = ast_channel_connected(ast)->id.number.valid ? ast_channel_connected(ast)->id.number.str : NULL;
   } else {
      l = NULL;
   }

   ss7_grab(p, p->ss7);

   if (p->call_level != SIG_SS7_CALL_LEVEL_ALLOCATED) {
      /* Call collision before sending IAM.  Abort call. */
      ss7_rel(p->ss7);
      return -1;
   }

   called_nai_strip = 0;
   ss7_called_nai = p->ss7->called_nai;
   if (ss7_called_nai == SS7_NAI_DYNAMIC) { /* compute dynamically */
      called_nai_strip = ss7_parse_prefix(p, c + p->stripmsd, &ss7_called_nai);
   }
   isup_set_called(p->ss7call, c + p->stripmsd + called_nai_strip, ss7_called_nai, p->ss7->ss7);

   calling_nai_strip = 0;
   ss7_calling_nai = p->ss7->calling_nai;
   if ((l != NULL) && (ss7_calling_nai == SS7_NAI_DYNAMIC)) { /* compute dynamically */
      calling_nai_strip = ss7_parse_prefix(p, l, &ss7_calling_nai);
   }

   isup_set_calling(p->ss7call, l ? (l + calling_nai_strip) : NULL, ss7_calling_nai,
      p->use_callingpres ? cid_pres2ss7pres(ast_channel_connected(ast)->id.number.presentation)
         : (l ? SS7_PRESENTATION_ALLOWED
            : (ast_channel_connected(ast)->id.number.presentation == AST_PRES_UNAVAILABLE
               ? SS7_PRESENTATION_ADDR_NOT_AVAILABLE : SS7_PRESENTATION_RESTRICTED)),
      p->use_callingpres ? cid_pres2ss7screen(ast_channel_connected(ast)->id.number.presentation) : SS7_SCREENING_USER_PROVIDED);

   isup_set_oli(p->ss7call, ast_channel_connected(ast)->ani2);

   /* Set the charge number if it is set */
   charge_str = pbx_builtin_getvar_helper(ast, "SS7_CHARGE_NUMBER");
   if (charge_str)
      isup_set_charge(p->ss7call, charge_str, SS7_ANI_CALLING_PARTY_SUB_NUMBER, 0x10);

   gen_address = pbx_builtin_getvar_helper(ast, "SS7_GENERIC_ADDRESS");
   if (gen_address)
      isup_set_gen_address(p->ss7call, gen_address, p->gen_add_nai,p->gen_add_pres_ind, p->gen_add_num_plan,p->gen_add_type); /* need to add some types here for NAI,PRES,TYPE */

   gen_digits = pbx_builtin_getvar_helper(ast, "SS7_GENERIC_DIGITS");
   gen_dig_type = pbx_builtin_getvar_helper(ast, "SS7_GENERIC_DIGTYPE");
   gen_dig_scheme = pbx_builtin_getvar_helper(ast, "SS7_GENERIC_DIGSCHEME");
   if (gen_digits)
      isup_set_gen_digits(p->ss7call, gen_digits, atoi(gen_dig_type), atoi(gen_dig_scheme));

   gen_name = pbx_builtin_getvar_helper(ast, "SS7_GENERIC_NAME");
   if (gen_name)
      isup_set_generic_name(p->ss7call, gen_name, GEN_NAME_TYPE_CALLING_NAME, GEN_NAME_AVAIL_AVAILABLE, GEN_NAME_PRES_ALLOWED);

   jip_digits = pbx_builtin_getvar_helper(ast, "SS7_JIP");
   if (jip_digits)
      isup_set_jip_digits(p->ss7call, jip_digits);

   lspi_ident = pbx_builtin_getvar_helper(ast, "SS7_LSPI_IDENT");
   if (lspi_ident)
      isup_set_lspi(p->ss7call, lspi_ident, 0x18, 0x7, 0x00);

   rlt_flag = pbx_builtin_getvar_helper(ast, "SS7_RLT_ON");
   if ((rlt_flag) && ((strncmp("NO", rlt_flag, strlen(rlt_flag))) != 0 )) {
      isup_set_lspi(p->ss7call, rlt_flag, 0x18, 0x7, 0x00); /* Setting for Nortel DMS-250/500 */
   }

   call_ref_id = pbx_builtin_getvar_helper(ast, "SS7_CALLREF_IDENT");
   call_ref_pc = pbx_builtin_getvar_helper(ast, "SS7_CALLREF_PC");
   if (call_ref_id && call_ref_pc) {
      isup_set_callref(p->ss7call, atoi(call_ref_id),
             call_ref_pc ? atoi(call_ref_pc) : 0);
   }

   send_far = pbx_builtin_getvar_helper(ast, "SS7_SEND_FAR");
   if (send_far && strncmp("NO", send_far, strlen(send_far)) != 0) {
      isup_far(p->ss7->ss7, p->ss7call);
   }

   tmr = pbx_builtin_getvar_helper(ast, "SS7_TMR_NUM");
   if (tmr) {
      isup_set_tmr(p->ss7call, atoi(tmr));
   } else if ((tmr = pbx_builtin_getvar_helper(ast, "SS7_TMR")) && tmr[0] != '\0') {
      if (!strcasecmp(tmr, "SPEECH")) {
         isup_set_tmr(p->ss7call, SS7_TMR_SPEECH);
      } else if (!strcasecmp(tmr, "SPARE")) {
         isup_set_tmr(p->ss7call, SS7_TMR_SPARE);
      } else if (!strcasecmp(tmr, "3K1_AUDIO")) {
         isup_set_tmr(p->ss7call, SS7_TMR_3K1_AUDIO);
      } else if (!strcasecmp(tmr, "64K_UNRESTRICTED")) {
         isup_set_tmr(p->ss7call, SS7_TMR_64K_UNRESTRICTED);
      } else {
         isup_set_tmr(p->ss7call, SS7_TMR_N64K_OR_SPARE);
      }
   }

   col_req = pbx_builtin_getvar_helper(ast, "SS7_COL_REQUEST");
   if (ast_true(col_req)) {
      isup_set_col_req(p->ss7call);
   }

   ss7_cug_indicator_str = pbx_builtin_getvar_helper(ast, "SS7_CUG_INDICATOR");
   if (!ast_strlen_zero(ss7_cug_indicator_str)) {
      if (!strcasecmp(ss7_cug_indicator_str, "OUTGOING_ALLOWED")) {
         ss7_cug_indicator = ISUP_CUG_OUTGOING_ALLOWED;
      } else if (!strcasecmp(ss7_cug_indicator_str, "OUTGOING_NOT_ALLOWED")) {
         ss7_cug_indicator = ISUP_CUG_OUTGOING_NOT_ALLOWED;
      } else {
         ss7_cug_indicator = ISUP_CUG_NON;
      }

      if (ss7_cug_indicator != ISUP_CUG_NON) {
         ss7_cug_interlock_code = pbx_builtin_getvar_helper(ast, "SS7_CUG_INTERLOCK_CODE");
         ss7_cug_interlock_ni = pbx_builtin_getvar_helper(ast, "SS7_CUG_INTERLOCK_NI");
         if (ss7_cug_interlock_code && ss7_cug_interlock_ni && strlen(ss7_cug_interlock_ni) == 4) {
            isup_set_cug(p->ss7call, ss7_cug_indicator, ss7_cug_interlock_ni, atoi(ss7_cug_interlock_code));
         }
      }
   }

   ss7_redirecting_update(p, ast);

   isup_set_echocontrol(p->ss7call, (p->ss7->flags & LINKSET_FLAG_DEFAULTECHOCONTROL) ? 1 : 0);
   ss7_interworking_indicator = pbx_builtin_getvar_helper(ast, "SS7_INTERWORKING_INDICATOR");
   if (ss7_interworking_indicator) {
      isup_set_interworking_indicator(p->ss7call, ast_true(ss7_interworking_indicator));
   }

   ss7_forward_indicator_pmbits = pbx_builtin_getvar_helper(ast, "SS7_FORWARD_INDICATOR_PMBITS");
   if (ss7_forward_indicator_pmbits) {
      isup_set_forward_indicator_pmbits(p->ss7call, atoi(ss7_forward_indicator_pmbits));
   }

   p->call_level = SIG_SS7_CALL_LEVEL_SETUP;
   p->do_hangup = SS7_HANGUP_SEND_REL;
   isup_iam(p->ss7->ss7, p->ss7call);
   sig_ss7_set_dialing(p, 1);
   ast_setstate(ast, AST_STATE_DIALING);
   ss7_rel(p->ss7);
   return 0;
}

/*!
 * \brief SS7 hangup channel.
 * \since 1.8
 *
 * \param p Signaling private structure pointer.
 * \param ast Asterisk channel structure pointer.
 *
 * \retval 0 on success.
 * \retval -1 on error.
 */
int sig_ss7_hangup(struct sig_ss7_chan *p, struct ast_channel *ast)
{
   if (!ast_channel_tech_pvt(ast)) {
      ast_log(LOG_WARNING, "Asked to hangup channel not connected\n");
      return 0;
   }

   p->owner = NULL;
   sig_ss7_set_dialing(p, 0);
   sig_ss7_set_outgoing(p, 0);
   p->progress = 0;
   p->rlt = 0;
   p->exten[0] = '\0';
   /* Perform low level hangup if no owner left */
   ss7_grab(p, p->ss7);
   p->call_level = SIG_SS7_CALL_LEVEL_IDLE;
   if (p->ss7call) {
      switch (p->do_hangup) {
      case SS7_HANGUP_SEND_REL:
         {
            const char *cause = pbx_builtin_getvar_helper(ast,"SS7_CAUSE");
            int icause = ast_channel_hangupcause(ast) ? ast_channel_hangupcause(ast) : -1;

            if (cause) {
               if (atoi(cause)) {
                  icause = atoi(cause);
               }
            }
            if (icause > 255) {
               icause = 16;
            }

            isup_rel(p->ss7->ss7, p->ss7call, icause);
            p->do_hangup = SS7_HANGUP_DO_NOTHING;
         }
         break;
      case SS7_HANGUP_SEND_RSC:
         ss7_do_rsc(p);
         p->do_hangup = SS7_HANGUP_DO_NOTHING;
         break;
      case SS7_HANGUP_SEND_RLC:
         isup_rlc(p->ss7->ss7, p->ss7call);
         p->do_hangup = SS7_HANGUP_DO_NOTHING;
         p->ss7call = isup_free_call_if_clear(p->ss7->ss7, p->ss7call);
         break;
      case SS7_HANGUP_FREE_CALL:
         p->do_hangup = SS7_HANGUP_DO_NOTHING;
         isup_free_call(p->ss7->ss7, p->ss7call);
         p->ss7call = NULL;
         break;
      case SS7_HANGUP_REEVENT_IAM:
         isup_event_iam(p->ss7->ss7, p->ss7call, p->dpc);
         p->do_hangup = SS7_HANGUP_SEND_REL;
         break;
      case SS7_HANGUP_DO_NOTHING:
         p->ss7call = isup_free_call_if_clear(p->ss7->ss7, p->ss7call);
         break;
      }
   }
   ss7_rel(p->ss7);

   return 0;
}

/*!
 * \brief SS7 answer channel.
 * \since 1.8
 *
 * \param p Signaling private structure pointer.
 * \param ast Asterisk channel structure pointer.
 *
 * \retval 0 on success.
 * \retval -1 on error.
 */
int sig_ss7_answer(struct sig_ss7_chan *p, struct ast_channel *ast)
{
   int res;

   ss7_grab(p, p->ss7);
   if (p->call_level < SIG_SS7_CALL_LEVEL_CONNECT) {
      if (p->call_level < SIG_SS7_CALL_LEVEL_PROCEEDING && (p->ss7->flags & LINKSET_FLAG_AUTOACM)) {
         isup_acm(p->ss7->ss7, p->ss7call);
      }
      p->call_level = SIG_SS7_CALL_LEVEL_CONNECT;
   }

   res = isup_anm(p->ss7->ss7, p->ss7call);
   sig_ss7_open_media(p);
   ss7_rel(p->ss7);
   return res;
}

/*!
 * \brief Fix up a channel:  If a channel is consumed, this is called.  Basically update any ->owner links.
 * \since 1.8
 *
 * \param oldchan Old channel pointer to replace.
 * \param newchan New channel pointer to set.
 * \param pchan Signaling private structure pointer.
 *
 * \return Nothing
 */
void sig_ss7_fixup(struct ast_channel *oldchan, struct ast_channel *newchan, struct sig_ss7_chan *pchan)
{
   if (pchan->owner == oldchan) {
      pchan->owner = newchan;
   }
}

/*!
 * \brief SS7 indication.
 * \since 1.8
 *
 * \param p Signaling private structure pointer.
 * \param chan Asterisk channel structure pointer.
 * \param condition AST control frame subtype.
 * \param data AST control frame payload contents.
 * \param datalen Length of payload contents.
 *
 * \retval 0 on success.
 * \retval -1 on error or indication condition not handled.
 */
int sig_ss7_indicate(struct sig_ss7_chan *p, struct ast_channel *chan, int condition, const void *data, size_t datalen)
{
   int res = -1;

   switch (condition) {
   case AST_CONTROL_BUSY:
      if (p->call_level < SIG_SS7_CALL_LEVEL_CONNECT) {
         ast_channel_hangupcause_set(chan, AST_CAUSE_USER_BUSY);
         ast_softhangup_nolock(chan, AST_SOFTHANGUP_DEV);
         res = 0;
         break;
      }
      res = sig_ss7_play_tone(p, SIG_SS7_TONE_BUSY);
      break;
   case AST_CONTROL_RINGING:
      ss7_grab(p, p->ss7);
      if (p->call_level < SIG_SS7_CALL_LEVEL_ALERTING && !p->outgoing) {
         if ((isup_far(p->ss7->ss7, p->ss7call)) != -1) {
            p->rlt = 1;
         }

         if (p->call_level < SIG_SS7_CALL_LEVEL_PROCEEDING && (p->ss7->flags & LINKSET_FLAG_AUTOACM)) {
            isup_acm(p->ss7->ss7, p->ss7call);
         }

         /* No need to send CPG if call will be RELEASE */
         if (p->rlt != 1) {
            isup_cpg(p->ss7->ss7, p->ss7call, CPG_EVENT_ALERTING);
         }

         p->call_level = SIG_SS7_CALL_LEVEL_ALERTING;
      }
      ss7_rel(p->ss7);

      res = sig_ss7_play_tone(p, SIG_SS7_TONE_RINGTONE);

      if (ast_channel_state(chan) != AST_STATE_UP && ast_channel_state(chan) != AST_STATE_RING) {
         ast_setstate(chan, AST_STATE_RINGING);
      }
      break;
   case AST_CONTROL_PROCEEDING:
      ast_debug(1,"Received AST_CONTROL_PROCEEDING on %s\n",ast_channel_name(chan));
      ss7_grab(p, p->ss7);
      /* This IF sends the FAR for an answered ALEG call */
      if (ast_channel_state(chan) == AST_STATE_UP && (p->rlt != 1)){
         if ((isup_far(p->ss7->ss7, p->ss7call)) != -1) {
            p->rlt = 1;
         }
      }

      if (p->call_level < SIG_SS7_CALL_LEVEL_PROCEEDING && !p->outgoing) {
         p->call_level = SIG_SS7_CALL_LEVEL_PROCEEDING;
         isup_acm(p->ss7->ss7, p->ss7call);
      }
      ss7_rel(p->ss7);
      /* don't continue in ast_indicate */
      res = 0;
      break;
   case AST_CONTROL_PROGRESS:
      ast_debug(1,"Received AST_CONTROL_PROGRESS on %s\n",ast_channel_name(chan));
      ss7_grab(p, p->ss7);
      if (!p->progress && p->call_level < SIG_SS7_CALL_LEVEL_ALERTING && !p->outgoing) {
         p->progress = 1;  /* No need to send inband-information progress again. */
         isup_cpg(p->ss7->ss7, p->ss7call, CPG_EVENT_INBANDINFO);

         /* enable echo canceler here on SS7 calls */
         if (!p->echocontrol_ind || !(p->ss7->flags & LINKSET_FLAG_USEECHOCONTROL)) {
            sig_ss7_set_echocanceller(p, 1);
         }
      }
      ss7_rel(p->ss7);
      /* don't continue in ast_indicate */
      res = 0;
      break;
   case AST_CONTROL_INCOMPLETE:
      if (p->call_level < SIG_SS7_CALL_LEVEL_CONNECT) {
         ast_channel_hangupcause_set(chan, AST_CAUSE_INVALID_NUMBER_FORMAT);
         ast_softhangup_nolock(chan, AST_SOFTHANGUP_DEV);
         res = 0;
         break;
      }
      /* Wait for DTMF digits to complete the dialed number. */
      res = 0;
      break;
   case AST_CONTROL_CONGESTION:
      if (p->call_level < SIG_SS7_CALL_LEVEL_CONNECT) {
         ast_channel_hangupcause_set(chan, AST_CAUSE_CONGESTION);
         ast_softhangup_nolock(chan, AST_SOFTHANGUP_DEV);
         res = 0;
         break;
      }
      res = sig_ss7_play_tone(p, SIG_SS7_TONE_CONGESTION);
      break;
   case AST_CONTROL_HOLD:
      ast_moh_start(chan, data, p->mohinterpret);
      break;
   case AST_CONTROL_UNHOLD:
      ast_moh_stop(chan);
      break;
   case AST_CONTROL_SRCUPDATE:
      res = 0;
      break;
   case AST_CONTROL_CONNECTED_LINE:
      ss7_connected_line_update(p, ast_channel_connected(chan));
      res = 0;
      break;
   case AST_CONTROL_REDIRECTING:
      ss7_redirecting_update(p, chan);
      res = 0;
      break;
   case -1:
      res = sig_ss7_play_tone(p, -1);
      break;
   }
   return res;
}

/*!
 * \brief SS7 channel request.
 * \since 1.8
 *
 * \param p Signaling private structure pointer.
 * \param law Companding law preferred
 * \param requestor Asterisk channel requesting a channel to dial (Can be NULL)
 * \param transfercapability
 *
 * \retval ast_channel on success.
 * \retval NULL on error.
 */
struct ast_channel *sig_ss7_request(struct sig_ss7_chan *p, enum sig_ss7_law law,
   const struct ast_assigned_ids *assignedids, const struct ast_channel *requestor,
   int transfercapability)
{
   struct ast_channel *ast;

   /* Companding law is determined by SS7 signaling type. */
   if (p->ss7->type == SS7_ITU) {
      law = SIG_SS7_ALAW;
   } else {
      law = SIG_SS7_ULAW;
   }

   sig_ss7_set_outgoing(p, 1);
   ast = sig_ss7_new_ast_channel(p, AST_STATE_RESERVED, law, transfercapability,
      p->exten, assignedids, requestor);
   if (!ast) {
      sig_ss7_set_outgoing(p, 0);

      /* Release the allocated channel.  Only have to deal with the linkset lock. */
      ast_mutex_lock(&p->ss7->lock);
      p->call_level = SIG_SS7_CALL_LEVEL_IDLE;
      isup_free_call(p->ss7->ss7, p->ss7call);
      ast_mutex_unlock(&p->ss7->lock);
   }
   return ast;
}

/*!
 * \brief Delete the sig_ss7 private channel structure.
 * \since 1.8
 *
 * \param doomed sig_ss7 private channel structure to delete.
 *
 * \return Nothing
 */
void sig_ss7_chan_delete(struct sig_ss7_chan *doomed)
{
   ast_free(doomed);
}

#define SIG_SS7_SC_HEADER  "%-4s %4s %-4s %-3s %-3s %-10s %-4s %s\n"
#define SIG_SS7_SC_LINE     "%4d %4d %-4s %-3s %-3s %-10s %-4s %s"
void sig_ss7_cli_show_channels_header(int fd)
{
   ast_cli(fd, SIG_SS7_SC_HEADER, "link", "",     "Chan", "Lcl", "Rem", "Call",  "SS7",  "Channel");
   ast_cli(fd, SIG_SS7_SC_HEADER, "set",  "Chan", "Idle", "Blk", "Blk", "Level", "Call", "Name");
}

void sig_ss7_cli_show_channels(int fd, struct sig_ss7_linkset *linkset)
{
   char line[256];
   int idx;
   struct sig_ss7_chan *pvt;

   ast_mutex_lock(&linkset->lock);
   for (idx = 0; idx < linkset->numchans; ++idx) {
      if (!linkset->pvts[idx]) {
         continue;
      }
      pvt = linkset->pvts[idx];
      sig_ss7_lock_private(pvt);
      sig_ss7_lock_owner(linkset, idx);

      snprintf(line, sizeof(line), SIG_SS7_SC_LINE,
         linkset->span,
         pvt->channel,
         sig_ss7_is_chan_available(pvt) ? "Yes" : "No",
         pvt->locallyblocked ? "Yes" : "No",
         pvt->remotelyblocked ? "Yes" : "No",
         sig_ss7_call_level2str(pvt->call_level),
         pvt->ss7call ? "Yes" : "No",
         pvt->owner ? ast_channel_name(pvt->owner) : "");

      if (pvt->owner) {
         ast_channel_unlock(pvt->owner);
      }
      sig_ss7_unlock_private(pvt);

      ast_mutex_unlock(&linkset->lock);
      ast_cli(fd, "%s\n", line);
      ast_mutex_lock(&linkset->lock);
   }
   ast_mutex_unlock(&linkset->lock);
}

/*!
 * \brief Create a new sig_ss7 private channel structure.
 * \since 1.8
 *
 * \param pvt_data Upper layer private data structure.
 * \param ss7 Controlling linkset for the channel.
 *
 * \retval sig_ss7_chan on success.
 * \retval NULL on error.
 */
struct sig_ss7_chan *sig_ss7_chan_new(void *pvt_data, struct sig_ss7_linkset *ss7)
{
   struct sig_ss7_chan *pvt;

   pvt = ast_calloc(1, sizeof(*pvt));
   if (!pvt) {
      return pvt;
   }

   pvt->chan_pvt = pvt_data;
   pvt->ss7 = ss7;

   return pvt;
}

/*!
 * \brief Initialize the SS7 linkset control.
 * \since 1.8
 *
 * \param ss7 SS7 linkset control structure.
 *
 * \return Nothing
 */
void sig_ss7_init_linkset(struct sig_ss7_linkset *ss7)
{
   int idx;

   memset(ss7, 0, sizeof(*ss7));

   ast_mutex_init(&ss7->lock);

   ss7->master = AST_PTHREADT_NULL;
   for (idx = 0; idx < ARRAY_LEN(ss7->fds); ++idx) {
      ss7->fds[idx] = -1;
   }
}

/* ------------------------------------------------------------------- */

#endif   /* defined(HAVE_SS7) */
/* end sig_ss7.c */