sig_ss7.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2010 Digium, Inc.
 *
 * Richard Mudgett <rmudgett@digium.com>
 *
 * 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 <creslin@digium.com>
 * \author Richard Mudgett <rmudgett@digium.com>
 *
 * 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.
 */
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.
 */
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.
 */
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.
 *
 * \retval 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.
 */
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.
 */
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.
 */
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.
 * \param ast_cause
 *
 * \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.
 */
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
 *
 * \return 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.
 *
 * \return 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
 */
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.
 *
 * \retval 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.
 */
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.
 */
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.
 */
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 linkset 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.
 *
 * \retval 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.
 */
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.
 */
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.
 */
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, "Unequipped 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
 *
 * \retval 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.
 *
 * \retval 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.
 *
 * \retval 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.
 *
 * \retval 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.
 */
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.
 */
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.
 * \param cur_slc
 *
 * \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.
 */
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 assignedids, 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.
 */
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.
 */
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 */