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Last updated: Sat Feb 3 05:00:36 2007

Asterisk developer's documentation :: Codename Pineapple

---

chan_mgcp.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2006, Digium, Inc.
 *
 * Mark Spencer <markster@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 Implementation of Media Gateway Control Protocol
 *
 * \author Mark Spencer <markster@digium.com>
 *
 * \par See also
 * \arg \ref Config_mgcp
 *
 * \ingroup channel_drivers
 */

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision: 51385 $")

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <errno.h>
#include <stdlib.h>
#include <fcntl.h>
#include <netdb.h>
#include <sys/signal.h>
#include <signal.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <arpa/inet.h>
#include <ctype.h>

#include "asterisk/lock.h"
#include "asterisk/channel.h"
#include "asterisk/config.h"
#include "asterisk/logger.h"
#include "asterisk/module.h"
#include "asterisk/pbx.h"
#include "asterisk/options.h"
#include "asterisk/lock.h"
#include "asterisk/sched.h"
#include "asterisk/io.h"
#include "asterisk/rtp.h"
#include "asterisk/acl.h"
#include "asterisk/callerid.h"
#include "asterisk/cli.h"
#include "asterisk/say.h"
#include "asterisk/cdr.h"
#include "asterisk/astdb.h"
#include "asterisk/features.h"
#include "asterisk/app.h"
#include "asterisk/musiconhold.h"
#include "asterisk/utils.h"
#include "asterisk/causes.h"
#include "asterisk/dsp.h"
#include "asterisk/devicestate.h"
#include "asterisk/stringfields.h"
#include "asterisk/abstract_jb.h"

#ifndef IPTOS_MINCOST
#define IPTOS_MINCOST 0x02
#endif

/*
 * Define to work around buggy dlink MGCP phone firmware which
 * appears not to know that "rt" is part of the "G" package.
 */
/* #define DLINK_BUGGY_FIRMWARE  */

#define MGCPDUMPER
#define DEFAULT_EXPIRY  120
#define MAX_EXPIRY   3600
#define CANREINVITE  1

#ifndef INADDR_NONE
#define INADDR_NONE (in_addr_t)(-1)
#endif

/*! Global jitterbuffer configuration - by default, jb is disabled */
static struct ast_jb_conf default_jbconf =
{
   .flags = 0,
   .max_size = -1,
   .resync_threshold = -1,
   .impl = ""
};
static struct ast_jb_conf global_jbconf;

static const char tdesc[] = "Media Gateway Control Protocol (MGCP)";
static const char config[] = "mgcp.conf";

#define MGCP_DTMF_RFC2833  (1 << 0)
#define MGCP_DTMF_INBAND   (1 << 1)
#define MGCP_DTMF_HYBRID   (1 << 2)

#define DEFAULT_MGCP_GW_PORT  2427 /*!< From RFC 2705 */
#define DEFAULT_MGCP_CA_PORT  2727 /*!< From RFC 2705 */
#define MGCP_MAX_PACKET    1500 /*!< Also from RFC 2543, should sub headers tho */
#define DEFAULT_RETRANS    1000 /*!< How frequently to retransmit */
#define MAX_RETRANS     5    /*!< Try only 5 times for retransmissions */

/*! MGCP rtp stream modes { */
#define MGCP_CX_SENDONLY   0
#define MGCP_CX_RECVONLY   1
#define MGCP_CX_SENDRECV   2
#define MGCP_CX_CONF    3
#define MGCP_CX_CONFERENCE 3
#define MGCP_CX_MUTE    4
#define MGCP_CX_INACTIVE   4
/*! } */

static char *mgcp_cxmodes[] = {
   "sendonly",
   "recvonly",
   "sendrecv",
   "confrnce",
   "inactive"
};

enum {
   MGCP_CMD_EPCF,
   MGCP_CMD_CRCX,
   MGCP_CMD_MDCX,
   MGCP_CMD_DLCX,
   MGCP_CMD_RQNT,
   MGCP_CMD_NTFY,
   MGCP_CMD_AUEP,
   MGCP_CMD_AUCX,
   MGCP_CMD_RSIP
};

static char context[AST_MAX_EXTENSION] = "default";

static char language[MAX_LANGUAGE] = "";
static char musicclass[MAX_MUSICCLASS] = "";
static char cid_num[AST_MAX_EXTENSION] = "";
static char cid_name[AST_MAX_EXTENSION] = "";

static int dtmfmode = 0;
static int nat = 0;

static ast_group_t cur_callergroup = 0;
static ast_group_t cur_pickupgroup = 0;

static int tos = 0;

static int immediate = 0;

static int callwaiting = 0;

static int callreturn = 0;

static int slowsequence = 0;

static int threewaycalling = 0;

/*! This is for flashhook transfers */
static int transfer = 0;

static int cancallforward = 0;

static int singlepath = 0;

static int canreinvite = CANREINVITE;

static char accountcode[AST_MAX_ACCOUNT_CODE] = "";

static char mailbox[AST_MAX_EXTENSION];

static int amaflags = 0;

static int adsi = 0;

static unsigned int oseq;

/*! Wait up to 16 seconds for first digit (FXO logic) */
static int firstdigittimeout = 16000;

/*! How long to wait for following digits (FXO logic) */
static int gendigittimeout = 8000;

/*! How long to wait for an extra digit, if there is an ambiguous match */
static int matchdigittimeout = 3000;

/*! Protect the monitoring thread, so only one process can kill or start it, and not
    when it's doing something critical. */
AST_MUTEX_DEFINE_STATIC(netlock);

AST_MUTEX_DEFINE_STATIC(monlock);

/*! This is the thread for the monitor which checks for input on the channels
    which are not currently in use. */
static pthread_t monitor_thread = AST_PTHREADT_NULL;

static int restart_monitor(void);

static int capability = AST_FORMAT_ULAW;
static int nonCodecCapability = AST_RTP_DTMF;

static char ourhost[MAXHOSTNAMELEN];
static struct in_addr __ourip;
static int ourport;

static int mgcpdebug = 0;

static struct sched_context *sched;
static struct io_context *io;
/*! The private structures of the  mgcp channels are linked for
  ! selecting outgoing channels */
   
#define MGCP_MAX_HEADERS   64
#define MGCP_MAX_LINES     64

struct mgcp_request {
   int len;
   char *verb;
   char *identifier;
   char *endpoint;
   char *version;
   int headers;         /*!< MGCP Headers */
   char *header[MGCP_MAX_HEADERS];
   int lines;        /*!< SDP Content */
   char *line[MGCP_MAX_LINES];
   char data[MGCP_MAX_PACKET];
   int cmd;                        /*!< int version of verb = command */
   unsigned int trid;              /*!< int version of identifier = transaction id */
   struct mgcp_request *next;      /*!< next in the queue */
};

/*! \brief mgcp_message: MGCP message for queuing up */
struct mgcp_message {
   struct mgcp_endpoint *owner_ep;
   struct mgcp_subchannel *owner_sub;
   int retrans;
   unsigned long expire;
   unsigned int seqno;
   int len;
   struct mgcp_message *next;
   char buf[0];
};

#define RESPONSE_TIMEOUT 30   /*!< in seconds */

struct mgcp_response {
   time_t whensent;
   int len;
   int seqno;
   struct mgcp_response *next;
   char buf[0];
};

#define MAX_SUBS 2

#define SUB_REAL 0
#define SUB_ALT  1

struct mgcp_subchannel {
   /*! subchannel magic string. 
      Needed to prove that any subchannel pointer passed by asterisk 
      really points to a valid subchannel memory area.
      Ugly.. But serves the purpose for the time being.
    */
#define MGCP_SUBCHANNEL_MAGIC "!978!"
   char magic[6]; 
   ast_mutex_t lock;
   int id;
   struct ast_channel *owner;
   struct mgcp_endpoint *parent;
   struct ast_rtp *rtp;
   struct sockaddr_in tmpdest;
   char txident[80]; /*! \todo FIXME txident is replaced by rqnt_ident in endpoint. 
         This should be obsoleted */
   char cxident[80];
   char callid[80];
   int cxmode;
   struct mgcp_request *cx_queue; /*!< pending CX commands */
   ast_mutex_t cx_queue_lock;     /*!< CX queue lock */
   int nat;
   int iseq;                      /*!< Not used? RTP? */
   int outgoing;
   int alreadygone;
   struct mgcp_subchannel *next;  /*!< for out circular linked list */
};

#define MGCP_ONHOOK  1
#define MGCP_OFFHOOK 2

#define TYPE_TRUNK 1
#define TYPE_LINE  2

struct mgcp_endpoint {
   ast_mutex_t lock;
   char name[80];
   struct mgcp_subchannel *sub;     /*!< Pointer to our current connection, channel and stuff */
   char accountcode[AST_MAX_ACCOUNT_CODE];
   char exten[AST_MAX_EXTENSION];      /*!< Extention where to start */
   char context[AST_MAX_EXTENSION];
   char language[MAX_LANGUAGE];
   char cid_num[AST_MAX_EXTENSION]; /*!< Caller*ID number */
   char cid_name[AST_MAX_EXTENSION];   /*!< Caller*ID name */
   char lastcallerid[AST_MAX_EXTENSION];  /*!< Last Caller*ID */
   char call_forward[AST_MAX_EXTENSION];  /*!< Last Caller*ID */
   char mailbox[AST_MAX_EXTENSION];
   char musicclass[MAX_MUSICCLASS];
   char curtone[80];       /*!< Current tone */
   ast_group_t callgroup;
   ast_group_t pickupgroup;
   int callwaiting;
   int hascallwaiting;
   int transfer;
   int threewaycalling;
   int singlepath;
   int cancallforward;
   int canreinvite;
   int callreturn;
   int dnd; /* How does this affect callwait? Do we just deny a mgcp_request if we're dnd? */
   int hascallerid;
   int hidecallerid;
   int dtmfmode;
   int amaflags;
   int type;
   int slowsequence;       /*!< MS: Sequence the endpoint as a whole */
   int group;
   int iseq; /*!< Not used? */
   int lastout; /*!< tracking this on the subchannels.  Is it needed here? */
   int needdestroy; /*!< Not used? */
   int capability;
   int nonCodecCapability;
   int onhooktime;
   int msgstate; /*!< voicemail message state */
   int immediate;
   int hookstate;
   int adsi;
   char rqnt_ident[80];             /*!< request identifier */
   struct mgcp_request *rqnt_queue; /*!< pending RQNT commands */
   ast_mutex_t rqnt_queue_lock;
   struct mgcp_request *cmd_queue;  /*!< pending commands other than RQNT */
   ast_mutex_t cmd_queue_lock;
   int delme;                       /*!< needed for reload */
   int needaudit;                   /*!< needed for reload */
   struct ast_dsp *dsp; /*!< XXX Should there be a dsp/subchannel? XXX */
   /* owner is tracked on the subchannels, and the *sub indicates whos in charge */
   /* struct ast_channel *owner; */
   /* struct ast_rtp *rtp; */
   /* struct sockaddr_in tmpdest; */
   /* message go the the endpoint and not the channel so they stay here */
   struct mgcp_endpoint *next;
   struct mgcp_gateway *parent;
};

static struct mgcp_gateway {
   /* A gateway containing one or more endpoints */
   char name[80];
   int isnamedottedip; /*!< is the name FQDN or dotted ip */
   struct sockaddr_in addr;
   struct sockaddr_in defaddr;
   struct in_addr ourip;
   int dynamic;
   int expire;    /*!< XXX Should we ever expire dynamic registrations? XXX */
   struct mgcp_endpoint *endpoints;
   struct ast_ha *ha;
/* obsolete
   time_t lastouttime;
   int lastout;
   int messagepending;
*/
/* Wildcard endpoint name */
   char wcardep[30];
   struct mgcp_message *msgs; /*!< gw msg queue */
   ast_mutex_t msgs_lock;     /*!< queue lock */  
   int retransid;             /*!< retrans timer id */
   int delme;                 /*!< needed for reload */
   struct mgcp_response *responses;
   struct mgcp_gateway *next;
} *gateways;

AST_MUTEX_DEFINE_STATIC(mgcp_reload_lock);
static int mgcp_reloading = 0;

/*! \brief gatelock: mutex for gateway/endpoint lists */
AST_MUTEX_DEFINE_STATIC(gatelock);

static int mgcpsock  = -1;

static struct sockaddr_in bindaddr;

static struct ast_frame  *mgcp_read(struct ast_channel *ast);
static int transmit_response(struct mgcp_subchannel *sub, char *msg, struct mgcp_request *req, char *msgrest);
static int transmit_notify_request(struct mgcp_subchannel *sub, char *tone);
static int transmit_modify_request(struct mgcp_subchannel *sub);
static int transmit_notify_request_with_callerid(struct mgcp_subchannel *sub, char *tone, char *callernum, char *callername);
static int transmit_modify_with_sdp(struct mgcp_subchannel *sub, struct ast_rtp *rtp, int codecs);
static int transmit_connection_del(struct mgcp_subchannel *sub);
static int transmit_audit_endpoint(struct mgcp_endpoint *p);
static void start_rtp(struct mgcp_subchannel *sub);
static void handle_response(struct mgcp_endpoint *p, struct mgcp_subchannel *sub,  
                            int result, unsigned int ident, struct mgcp_request *resp);
static void dump_cmd_queues(struct mgcp_endpoint *p, struct mgcp_subchannel *sub);
static int mgcp_do_reload(void);
static int mgcp_reload(int fd, int argc, char *argv[]);

static struct ast_channel *mgcp_request(const char *type, int format, void *data, int *cause);
static int mgcp_call(struct ast_channel *ast, char *dest, int timeout);
static int mgcp_hangup(struct ast_channel *ast);
static int mgcp_answer(struct ast_channel *ast);
static struct ast_frame *mgcp_read(struct ast_channel *ast);
static int mgcp_write(struct ast_channel *ast, struct ast_frame *frame);
static int mgcp_indicate(struct ast_channel *ast, int ind, const void *data, size_t datalen);
static int mgcp_fixup(struct ast_channel *oldchan, struct ast_channel *newchan);
static int mgcp_senddigit_begin(struct ast_channel *ast, char digit);
static int mgcp_senddigit_end(struct ast_channel *ast, char digit, unsigned int duration);
static int mgcp_devicestate(void *data);

static const struct ast_channel_tech mgcp_tech = {
   .type = "MGCP",
   .description = tdesc,
   .capabilities = AST_FORMAT_ULAW,
   .properties = AST_CHAN_TP_WANTSJITTER | AST_CHAN_TP_CREATESJITTER,
   .requester = mgcp_request,
   .devicestate = mgcp_devicestate,
   .call = mgcp_call,
   .hangup = mgcp_hangup,
   .answer = mgcp_answer,
   .read = mgcp_read,
   .write = mgcp_write,
   .indicate = mgcp_indicate,
   .fixup = mgcp_fixup,
   .send_digit_begin = mgcp_senddigit_begin,
   .send_digit_end = mgcp_senddigit_end,
   .bridge = ast_rtp_bridge,
};

static int has_voicemail(struct mgcp_endpoint *p)
{
   return ast_app_has_voicemail(p->mailbox, NULL);
}

static int unalloc_sub(struct mgcp_subchannel *sub)
{
   struct mgcp_endpoint *p = sub->parent;
   if (p->sub == sub) {
      ast_log(LOG_WARNING, "Trying to unalloc the real channel %s@%s?!?\n", p->name, p->parent->name);
      return -1;
   }
   if (option_debug)
      ast_log(LOG_DEBUG, "Released sub %d of channel %s@%s\n", sub->id, p->name, p->parent->name);

   sub->owner = NULL;
   if (!ast_strlen_zero(sub->cxident)) {
      transmit_connection_del(sub);
   }
   sub->cxident[0] = '\0';
   sub->callid[0] = '\0';
   sub->cxmode = MGCP_CX_INACTIVE;
   sub->outgoing = 0;
   sub->alreadygone = 0;
   memset(&sub->tmpdest, 0, sizeof(sub->tmpdest));
   if (sub->rtp) {
      ast_rtp_destroy(sub->rtp);
      sub->rtp = NULL;
   }
   dump_cmd_queues(NULL, sub); /* SC */
   return 0;
}

/* modified for new transport mechanism */
static int __mgcp_xmit(struct mgcp_gateway *gw, char *data, int len)
{
   int res;
   if (gw->addr.sin_addr.s_addr)
      res=sendto(mgcpsock, data, len, 0, (struct sockaddr *)&gw->addr, sizeof(struct sockaddr_in));
   else 
      res=sendto(mgcpsock, data, len, 0, (struct sockaddr *)&gw->defaddr, sizeof(struct sockaddr_in));
   if (res != len) {
      ast_log(LOG_WARNING, "mgcp_xmit returned %d: %s\n", res, strerror(errno));
   }
   return res;
}

static int resend_response(struct mgcp_subchannel *sub, struct mgcp_response *resp)
{
   struct mgcp_endpoint *p = sub->parent;
   int res;
   if (mgcpdebug) {
      ast_verbose("Retransmitting:\n%s\n to %s:%d\n", resp->buf, ast_inet_ntoa(p->parent->addr.sin_addr), ntohs(p->parent->addr.sin_port));
   }
   res = __mgcp_xmit(p->parent, resp->buf, resp->len);
   if (res > 0)
      res = 0;
   return res;
}

static int send_response(struct mgcp_subchannel *sub, struct mgcp_request *req)
{
   struct mgcp_endpoint *p = sub->parent;
   int res;
   if (mgcpdebug) {
      ast_verbose("Transmitting:\n%s\n to %s:%d\n", req->data, ast_inet_ntoa(p->parent->addr.sin_addr), ntohs(p->parent->addr.sin_port));
   }
   res = __mgcp_xmit(p->parent, req->data, req->len);
   if (res > 0)
      res = 0;
   return res;
}

/* modified for new transport framework */
static void dump_queue(struct mgcp_gateway *gw, struct mgcp_endpoint *p)
{
   struct mgcp_message *cur, *q = NULL, *w, *prev;

   ast_mutex_lock(&gw->msgs_lock);
   prev = NULL, cur = gw->msgs;
   while (cur) {
      if (!p || cur->owner_ep == p) {
         if (prev)
            prev->next = cur->next;
         else
            gw->msgs = cur->next;

         ast_log(LOG_NOTICE, "Removing message from %s transaction %u\n", 
            gw->name, cur->seqno);

         w = cur;
         cur = cur->next;
         if (q) {
            w->next = q;
         } else {
            w->next = NULL;
         }
         q = w;
      } else {
         prev = cur, cur=cur->next;
      }
   }
   ast_mutex_unlock(&gw->msgs_lock);

   while (q) {
      cur = q;
      q = q->next;
      free(cur);
   }
}

static void mgcp_queue_frame(struct mgcp_subchannel *sub, struct ast_frame *f)
{
   for(;;) {
      if (sub->owner) {
         if (!ast_mutex_trylock(&sub->owner->lock)) {
            ast_queue_frame(sub->owner, f);
            ast_mutex_unlock(&sub->owner->lock);
            break;
         } else {
            ast_mutex_unlock(&sub->lock);
            usleep(1);
            ast_mutex_lock(&sub->lock);
         }
      } else
         break;
   }
}

static void mgcp_queue_hangup(struct mgcp_subchannel *sub)
{
   for(;;) {
      if (sub->owner) {
         if (!ast_mutex_trylock(&sub->owner->lock)) {
            ast_queue_hangup(sub->owner);
            ast_mutex_unlock(&sub->owner->lock);
            break;
         } else {
            ast_mutex_unlock(&sub->lock);
            usleep(1);
            ast_mutex_lock(&sub->lock);
         }
      } else
         break;
   }
}

static void mgcp_queue_control(struct mgcp_subchannel *sub, int control)
{
   struct ast_frame f = { AST_FRAME_CONTROL, };
   f.subclass = control;
   return mgcp_queue_frame(sub, &f);
}

static int retrans_pkt(void *data)
{
   struct mgcp_gateway *gw = (struct mgcp_gateway *)data;
   struct mgcp_message *cur, *exq = NULL, *w, *prev;
   int res = 0;

   /* find out expired msgs */
   ast_mutex_lock(&gw->msgs_lock);

   prev = NULL, cur = gw->msgs;
   while (cur) {
      if (cur->retrans < MAX_RETRANS) {
         cur->retrans++;
         if (mgcpdebug) {
            ast_verbose("Retransmitting #%d transaction %u on [%s]\n",
               cur->retrans, cur->seqno, gw->name);
         }
         __mgcp_xmit(gw, cur->buf, cur->len);

         prev = cur;
         cur = cur->next;
      } else {
         if (prev)
            prev->next = cur->next;
         else
            gw->msgs = cur->next;

         ast_log(LOG_WARNING, "Maximum retries exceeded for transaction %u on [%s]\n",
            cur->seqno, gw->name);

         w = cur;
         cur = cur->next;

         if (exq) {
            w->next = exq;
         } else {
            w->next = NULL;
         }
         exq = w;
      }
   }

   if (!gw->msgs) {
      gw->retransid = -1;
      res = 0;
   } else {
      res = 1;
   }
   ast_mutex_unlock(&gw->msgs_lock);

   while (exq) {
      cur = exq;
      /* time-out transaction */
      handle_response(cur->owner_ep, cur->owner_sub, 406, cur->seqno, NULL); 
      exq = exq->next;
      free(cur);
   }

   return res;
}

/* modified for the new transaction mechanism */
static int mgcp_postrequest(struct mgcp_endpoint *p, struct mgcp_subchannel *sub, 
                            char *data, int len, unsigned int seqno)
{
   struct mgcp_message *msg = malloc(sizeof(struct mgcp_message) + len);
   struct mgcp_message *cur;
   struct mgcp_gateway *gw = ((p && p->parent) ? p->parent : NULL);
   struct timeval tv;

   if (!msg) {
      return -1;
   }
   if (!gw) {
      return -1;
   }
/* SC
   time(&t);
   if (gw->messagepending && (gw->lastouttime + 20 < t)) {
      ast_log(LOG_NOTICE, "Timeout waiting for response to message:%d,  lastouttime: %ld, now: %ld.  Dumping pending queue\n",
         gw->msgs ? gw->msgs->seqno : -1, (long) gw->lastouttime, (long) t);
      dump_queue(sub->parent);
   }
*/
   msg->owner_sub = sub;
   msg->owner_ep = p;
   msg->seqno = seqno;
   msg->next = NULL;
   msg->len = len;
   msg->retrans = 0;
   memcpy(msg->buf, data, msg->len);

   ast_mutex_lock(&gw->msgs_lock);
   cur = gw->msgs;
   if (cur) {
      while(cur->next)
         cur = cur->next;
      cur->next = msg;
   } else {
      gw->msgs = msg;
   }

   if (gettimeofday(&tv, NULL) < 0) {
      /* This shouldn't ever happen, but let's be sure */
      ast_log(LOG_NOTICE, "gettimeofday() failed!\n");
   } else {
      msg->expire = tv.tv_sec * 1000 + tv.tv_usec / 1000 + DEFAULT_RETRANS;

      if (gw->retransid == -1)
         gw->retransid = ast_sched_add(sched, DEFAULT_RETRANS, retrans_pkt, (void *)gw);
   }
   ast_mutex_unlock(&gw->msgs_lock);
/* SC
   if (!gw->messagepending) {
      gw->messagepending = 1;
      gw->lastout = seqno;
      gw->lastouttime = t;
*/
   __mgcp_xmit(gw, msg->buf, msg->len);
      /* XXX Should schedule retransmission XXX */
/* SC
   } else
      if (option_debug)
         ast_log(LOG_DEBUG, "Deferring transmission of transaction %d\n", seqno);
*/
   return 0;
}

/* modified for new transport */
static int send_request(struct mgcp_endpoint *p, struct mgcp_subchannel *sub, 
                        struct mgcp_request *req, unsigned int seqno)
{
   int res = 0;
   struct mgcp_request **queue, *q, *r, *t;
   ast_mutex_t *l;

   if (option_debug)
      ast_log(LOG_DEBUG, "Slow sequence is %d\n", p->slowsequence);
   if (p->slowsequence) {
      queue = &p->cmd_queue;
      l = &p->cmd_queue_lock;
      ast_mutex_lock(l);
   } else {
      switch (req->cmd) {
      case MGCP_CMD_DLCX:
         queue = &sub->cx_queue;
         l = &sub->cx_queue_lock;
         ast_mutex_lock(l);
         q = sub->cx_queue;
         /* delete pending cx cmds */
         while (q) {
            r = q->next;
            free(q);
            q = r;
         }
         *queue = NULL;
         break;

      case MGCP_CMD_CRCX:
      case MGCP_CMD_MDCX:
         queue = &sub->cx_queue;
         l = &sub->cx_queue_lock;
         ast_mutex_lock(l);
         break;

      case MGCP_CMD_RQNT:
         queue = &p->rqnt_queue;
         l = &p->rqnt_queue_lock;
         ast_mutex_lock(l);
         break;

      default:
         queue = &p->cmd_queue;
         l = &p->cmd_queue_lock;
         ast_mutex_lock(l);
         break;
      }
   }

   r = (struct mgcp_request *) malloc (sizeof(struct mgcp_request));
   if (!r) {
      ast_log(LOG_WARNING, "Cannot post MGCP request: insufficient memory\n");
      ast_mutex_unlock(l);
      return -1;
   }
   memcpy(r, req, sizeof(struct mgcp_request));

   if (!(*queue)) {
      if (mgcpdebug) {
         ast_verbose("Posting Request:\n%s to %s:%d\n", req->data, 
            ast_inet_ntoa(p->parent->addr.sin_addr), ntohs(p->parent->addr.sin_port));
      }

      res = mgcp_postrequest(p, sub, req->data, req->len, seqno);
   } else {
      if (mgcpdebug) {
         ast_verbose("Queueing Request:\n%s to %s:%d\n", req->data, 
            ast_inet_ntoa(p->parent->addr.sin_addr), ntohs(p->parent->addr.sin_port));
      }
   }

   /* XXX find tail. We could also keep tail in the data struct for faster access */
   for (t = *queue; t && t->next; t = t->next);

   r->next = NULL;
   if (t)
      t->next = r;
   else
      *queue = r;

   ast_mutex_unlock(l);

   return res;
}

static int mgcp_call(struct ast_channel *ast, char *dest, int timeout)
{
   int res;
   struct mgcp_endpoint *p;
   struct mgcp_subchannel *sub;
   char tone[50] = "";
   const char *distinctive_ring = NULL;
   struct varshead *headp;
   struct ast_var_t *current;

   if (mgcpdebug) {
      ast_verbose(VERBOSE_PREFIX_3 "MGCP mgcp_call(%s)\n", ast->name);
   }
   sub = ast->tech_pvt;
   p = sub->parent;
   headp = &ast->varshead;
   AST_LIST_TRAVERSE(headp,current,entries) {
      /* Check whether there is an ALERT_INFO variable */
      if (strcasecmp(ast_var_name(current),"ALERT_INFO") == 0) {
         distinctive_ring = ast_var_value(current);
      }
   }

   ast_mutex_lock(&sub->lock);
   switch (p->hookstate) {
   case MGCP_OFFHOOK:
      if (!ast_strlen_zero(distinctive_ring)) {
         snprintf(tone, sizeof(tone), "L/wt%s", distinctive_ring);
         if (mgcpdebug) {
            ast_verbose(VERBOSE_PREFIX_3 "MGCP distinctive callwait %s\n", tone);
         }
      } else {
         snprintf(tone, sizeof(tone), "L/wt");
         if (mgcpdebug) {
            ast_verbose(VERBOSE_PREFIX_3 "MGCP normal callwait %s\n", tone);
         }
      }
      break;
   case MGCP_ONHOOK:
   default:
      if (!ast_strlen_zero(distinctive_ring)) {
         snprintf(tone, sizeof(tone), "L/r%s", distinctive_ring);
         if (mgcpdebug) {
            ast_verbose(VERBOSE_PREFIX_3 "MGCP distinctive ring %s\n", tone);
         }
      } else {
         snprintf(tone, sizeof(tone), "L/rg");
         if (mgcpdebug) {
            ast_verbose(VERBOSE_PREFIX_3 "MGCP default ring\n");
         }
      }
      break;
   }

   if ((ast->_state != AST_STATE_DOWN) && (ast->_state != AST_STATE_RESERVED)) {
      ast_log(LOG_WARNING, "mgcp_call called on %s, neither down nor reserved\n", ast->name);
      ast_mutex_unlock(&sub->lock);
      return -1;
   }

   res = 0;
   sub->outgoing = 1;
   sub->cxmode = MGCP_CX_RECVONLY;
   if (p->type == TYPE_LINE) {
      if (!sub->rtp) {
         start_rtp(sub);
      } else {
         transmit_modify_request(sub);
      }

      if (sub->next->owner && !ast_strlen_zero(sub->next->cxident) && !ast_strlen_zero(sub->next->callid)) {
         /* try to prevent a callwait from disturbing the other connection */
         sub->next->cxmode = MGCP_CX_RECVONLY;
         transmit_modify_request(sub->next);
      }

      transmit_notify_request_with_callerid(sub, tone, ast->cid.cid_num, ast->cid.cid_name);
      ast_setstate(ast, AST_STATE_RINGING);

      if (sub->next->owner && !ast_strlen_zero(sub->next->cxident) && !ast_strlen_zero(sub->next->callid)) {
         /* Put the connection back in sendrecv */
         sub->next->cxmode = MGCP_CX_SENDRECV;
         transmit_modify_request(sub->next);
      }
   } else {
      ast_log(LOG_NOTICE, "Don't know how to dial on trunks yet\n");
      res = -1;
   }
   ast_mutex_unlock(&sub->lock);
   ast_queue_control(ast, AST_CONTROL_RINGING);
   return res;
}

static int mgcp_hangup(struct ast_channel *ast)
{
   struct mgcp_subchannel *sub = ast->tech_pvt;
   struct mgcp_endpoint *p = sub->parent;

   if (option_debug) {
      ast_log(LOG_DEBUG, "mgcp_hangup(%s)\n", ast->name);
   }
   if (!ast->tech_pvt) {
      if (option_debug)
         ast_log(LOG_DEBUG, "Asked to hangup channel not connected\n");
      return 0;
   }
   if (strcmp(sub->magic, MGCP_SUBCHANNEL_MAGIC)) {
      if (option_debug)
         ast_log(LOG_DEBUG, "Invalid magic. MGCP subchannel freed up already.\n");
      return 0;
   }
   ast_mutex_lock(&sub->lock);
   if (mgcpdebug) {
      ast_verbose(VERBOSE_PREFIX_3 "MGCP mgcp_hangup(%s) on %s@%s\n", ast->name, p->name, p->parent->name);
   }

   if ((p->dtmfmode & MGCP_DTMF_INBAND) && p->dsp) {
      /* check whether other channel is active. */
      if (!sub->next->owner) {
         if (p->dtmfmode & MGCP_DTMF_HYBRID)
            p->dtmfmode &= ~MGCP_DTMF_INBAND;
         if (mgcpdebug) {
            ast_verbose(VERBOSE_PREFIX_2 "MGCP free dsp on %s@%s\n", p->name, p->parent->name);
         }
         ast_dsp_free(p->dsp);
         p->dsp = NULL;
      }
   }

   sub->owner = NULL;
   if (!ast_strlen_zero(sub->cxident)) {
      transmit_connection_del(sub);
   }
   sub->cxident[0] = '\0';
   if ((sub == p->sub) && sub->next->owner) {
      if (p->hookstate == MGCP_OFFHOOK) {
         if (sub->next->owner && ast_bridged_channel(sub->next->owner)) {
            transmit_notify_request_with_callerid(p->sub, "L/wt", ast_bridged_channel(sub->next->owner)->cid.cid_num, ast_bridged_channel(sub->next->owner)->cid.cid_name);
         }
      } else {
         /* set our other connection as the primary and swith over to it */
         p->sub = sub->next;
         p->sub->cxmode = MGCP_CX_RECVONLY;
         transmit_modify_request(p->sub);
         if (sub->next->owner && ast_bridged_channel(sub->next->owner)) {
            transmit_notify_request_with_callerid(p->sub, "L/rg", ast_bridged_channel(sub->next->owner)->cid.cid_num, ast_bridged_channel(sub->next->owner)->cid.cid_name);
         }
      }

   } else if ((sub == p->sub->next) && p->hookstate == MGCP_OFFHOOK) {
      transmit_notify_request(sub, "L/v");
   } else if (p->hookstate == MGCP_OFFHOOK) {
      transmit_notify_request(sub, "L/ro");
   } else {
      transmit_notify_request(sub, "");
   }

   ast->tech_pvt = NULL;
   sub->alreadygone = 0;
   sub->outgoing = 0;
   sub->cxmode = MGCP_CX_INACTIVE;
   sub->callid[0] = '\0';
   /* Reset temporary destination */
   memset(&sub->tmpdest, 0, sizeof(sub->tmpdest));
   if (sub->rtp) {
      ast_rtp_destroy(sub->rtp);
      sub->rtp = NULL;
   }

   ast_module_unref(ast_module_info->self);

   if ((p->hookstate == MGCP_ONHOOK) && (!sub->next->rtp)) {
      p->hidecallerid = 0;
      if (p->hascallwaiting && !p->callwaiting) {
         if (option_verbose > 2)
            ast_verbose(VERBOSE_PREFIX_3 "Enabling call waiting on %s\n", ast->name);
         p->callwaiting = -1;
      }
      if (has_voicemail(p)) {
         if (mgcpdebug) {
            ast_verbose(VERBOSE_PREFIX_3 "MGCP mgcp_hangup(%s) on %s@%s set vmwi(+)\n", 
               ast->name, p->name, p->parent->name);
         }
         transmit_notify_request(sub, "L/vmwi(+)");
      } else {
         if (mgcpdebug) {
            ast_verbose(VERBOSE_PREFIX_3 "MGCP mgcp_hangup(%s) on %s@%s set vmwi(-)\n", 
               ast->name, p->name, p->parent->name);
         }
         transmit_notify_request(sub, "L/vmwi(-)");
      }
   }
   ast_mutex_unlock(&sub->lock);
   return 0;
}

static int mgcp_show_endpoints(int fd, int argc, char *argv[])
{
   struct mgcp_gateway  *g;
   struct mgcp_endpoint *e;
   int hasendpoints = 0;

   if (argc != 3) 
      return RESULT_SHOWUSAGE;
   ast_mutex_lock(&gatelock);
   g = gateways;
   while(g) {
      e = g->endpoints;
      ast_cli(fd, "Gateway '%s' at %s (%s)\n", g->name, g->addr.sin_addr.s_addr ? ast_inet_ntoa(g->addr.sin_addr) : ast_inet_ntoa(g->defaddr.sin_addr), g->dynamic ? "Dynamic" : "Static");
      while(e) {
         /* Don't show wilcard endpoint */
         if (strcmp(e->name, g->wcardep) !=0)
            ast_cli(fd, "   -- '%s@%s in '%s' is %s\n", e->name, g->name, e->context, e->sub->owner ? "active" : "idle");
         hasendpoints = 1;
         e = e->next;
      }
      if (!hasendpoints) {
         ast_cli(fd, "   << No Endpoints Defined >>     ");
      }
      g = g->next;
   }
   ast_mutex_unlock(&gatelock);
   return RESULT_SUCCESS;
}

static const char show_endpoints_usage[] = 
"Usage: mgcp show endpoints\n"
"       Lists all endpoints known to the MGCP (Media Gateway Control Protocol) subsystem.\n";

static const char audit_endpoint_usage[] = 
"Usage: mgcp audit endpoint <endpointid>\n"
"       Lists the capabilities of an endpoint in the MGCP (Media Gateway Control Protocol) subsystem.\n"
"       mgcp debug MUST be on to see the results of this command.\n";

static const char debug_usage[] = 
"Usage: mgcp set debug\n"
"       Enables dumping of MGCP packets for debugging purposes\n";

static const char no_debug_usage[] = 
"Usage: mgcp set debug off\n"
"       Disables dumping of MGCP packets for debugging purposes\n";

static const char mgcp_reload_usage[] =
"Usage: mgcp reload\n"
"       Reloads MGCP configuration from mgcp.conf\n"
"       Deprecated:  please use 'reload chan_mgcp.so' instead.\n";

static int mgcp_audit_endpoint(int fd, int argc, char *argv[])
{
   struct mgcp_gateway  *g;
   struct mgcp_endpoint *e;
   int found = 0;
   char *ename,*gname, *c;

   if (!mgcpdebug) {
      return RESULT_SHOWUSAGE;
   }
   if (argc != 4) 
      return RESULT_SHOWUSAGE;
   /* split the name into parts by null */
   ename = argv[3];
   gname = ename;
   while (*gname) {
      if (*gname == '@') {
         *gname = 0;
         gname++;
         break;
      }
      gname++;
   }
   if (gname[0] == '[')
      gname++;
   if ((c = strrchr(gname, ']')))
      *c = '\0';
   ast_mutex_lock(&gatelock);
   g = gateways;
   while(g) {
      if (!strcasecmp(g->name, gname)) {
         e = g->endpoints;
         while(e) {
            if (!strcasecmp(e->name, ename)) {
               found = 1;
               transmit_audit_endpoint(e);
               break;
            }
            e = e->next;
         }
         if (found) {
            break;
         }
      }
      g = g->next;
   }
   if (!found) {
      ast_cli(fd, "   << Could not find endpoint >>     ");
   }
   ast_mutex_unlock(&gatelock);
   return RESULT_SUCCESS;
}

static int mgcp_do_debug(int fd, int argc, char *argv[])
{
   if (argc != 3)
      return RESULT_SHOWUSAGE;
   mgcpdebug = 1;
   ast_cli(fd, "MGCP Debugging Enabled\n");
   return RESULT_SUCCESS;
}

static int mgcp_no_debug(int fd, int argc, char *argv[])
{
   if (argc != 4)
      return RESULT_SHOWUSAGE;
   mgcpdebug = 0;
   ast_cli(fd, "MGCP Debugging Disabled\n");
   return RESULT_SUCCESS;
}

static struct ast_cli_entry cli_mgcp[] = {
   { { "mgcp", "audit", "endpoint", NULL },
   mgcp_audit_endpoint, "Audit specified MGCP endpoint",
   audit_endpoint_usage },

   { { "mgcp", "show", "endpoints", NULL },
   mgcp_show_endpoints, "List defined MGCP endpoints",
   show_endpoints_usage },

   { { "mgcp", "set", "debug", NULL },
   mgcp_do_debug, "Enable MGCP debugging",
   debug_usage },

   { { "mgcp", "set", "debug", "off", NULL },
   mgcp_no_debug, "Disable MGCP debugging",
   no_debug_usage },

   { { "mgcp", "reload", NULL },
   mgcp_reload, "Reload MGCP configuration",
   mgcp_reload_usage },
};

static int mgcp_answer(struct ast_channel *ast)
{
   int res = 0;
   struct mgcp_subchannel *sub = ast->tech_pvt;
   struct mgcp_endpoint *p = sub->parent;

   ast_mutex_lock(&sub->lock);
   sub->cxmode = MGCP_CX_SENDRECV;
   if (!sub->rtp) {
      start_rtp(sub);
   } else {
      transmit_modify_request(sub);
   }
   /* verbose level check */
   if (option_verbose > 2) {
      ast_verbose(VERBOSE_PREFIX_3 "MGCP mgcp_answer(%s) on %s@%s-%d\n", 
         ast->name, p->name, p->parent->name, sub->id);
   }
   if (ast->_state != AST_STATE_UP) {
      ast_setstate(ast, AST_STATE_UP);
      if (option_debug)
         ast_log(LOG_DEBUG, "mgcp_answer(%s)\n", ast->name);
      transmit_notify_request(sub, "");
      transmit_modify_request(sub);
   }
   ast_mutex_unlock(&sub->lock);
   return res;
}

static struct ast_frame *mgcp_rtp_read(struct mgcp_subchannel *sub)
{
   /* Retrieve audio/etc from channel.  Assumes sub->lock is already held. */
   struct ast_frame *f;

   f = ast_rtp_read(sub->rtp);
   /* Don't send RFC2833 if we're not supposed to */
   if (f && (f->frametype == AST_FRAME_DTMF) && !(sub->parent->dtmfmode & MGCP_DTMF_RFC2833))
      return &ast_null_frame;
   if (sub->owner) {
      /* We already hold the channel lock */
      if (f->frametype == AST_FRAME_VOICE) {
         if (f->subclass != sub->owner->nativeformats) {
            if (option_debug)
               ast_log(LOG_DEBUG, "Oooh, format changed to %d\n", f->subclass);
            sub->owner->nativeformats = f->subclass;
            ast_set_read_format(sub->owner, sub->owner->readformat);
            ast_set_write_format(sub->owner, sub->owner->writeformat);
         }
         /* Courtesy fearnor aka alex@pilosoft.com */
         if ((sub->parent->dtmfmode & MGCP_DTMF_INBAND) && (sub->parent->dsp)) {
#if 0
            ast_log(LOG_NOTICE, "MGCP ast_dsp_process\n");
#endif
            f = ast_dsp_process(sub->owner, sub->parent->dsp, f);
         }
      }
   }
   return f;
}


static struct ast_frame *mgcp_read(struct ast_channel *ast)
{
   struct ast_frame *f;
   struct mgcp_subchannel *sub = ast->tech_pvt;
   ast_mutex_lock(&sub->lock);
   f = mgcp_rtp_read(sub);
   ast_mutex_unlock(&sub->lock);
   return f;
}

static int mgcp_write(struct ast_channel *ast, struct ast_frame *frame)
{
   struct mgcp_subchannel *sub = ast->tech_pvt;
   int res = 0;
   if (frame->frametype != AST_FRAME_VOICE) {
      if (frame->frametype == AST_FRAME_IMAGE)
         return 0;
      else {
         ast_log(LOG_WARNING, "Can't send %d type frames with MGCP write\n", frame->frametype);
         return 0;
      }
   } else {
      if (!(frame->subclass & ast->nativeformats)) {
         ast_log(LOG_WARNING, "Asked to transmit frame type %d, while native formats is %d (read/write = %d/%d)\n",
            frame->subclass, ast->nativeformats, ast->readformat, ast->writeformat);
         return -1;
      }
   }
   if (sub) {
      ast_mutex_lock(&sub->lock);
      if ((sub->parent->sub == sub) || !sub->parent->singlepath) {
         if (sub->rtp) {
            res =  ast_rtp_write(sub->rtp, frame);
         }
      }
      ast_mutex_unlock(&sub->lock);
   }
   return res;
}

static int mgcp_fixup(struct ast_channel *oldchan, struct ast_channel *newchan)
{
   struct mgcp_subchannel *sub = newchan->tech_pvt;

   ast_mutex_lock(&sub->lock);
   ast_log(LOG_NOTICE, "mgcp_fixup(%s, %s)\n", oldchan->name, newchan->name);
   if (sub->owner != oldchan) {
      ast_mutex_unlock(&sub->lock);
      ast_log(LOG_WARNING, "old channel wasn't %p but was %p\n", oldchan, sub->owner);
      return -1;
   }
   sub->owner = newchan;
   ast_mutex_unlock(&sub->lock);
   return 0;
}

static int mgcp_senddigit_begin(struct ast_channel *ast, char digit)
{
   /* Let asterisk play inband indications */
   return -1;
}

static int mgcp_senddigit_end(struct ast_channel *ast, char digit, unsigned int duration)
{
   struct mgcp_subchannel *sub = ast->tech_pvt;
   char tmp[4];

   tmp[0] = 'D';
   tmp[1] = '/';
   tmp[2] = digit;
   tmp[3] = '\0';
   ast_mutex_lock(&sub->lock);
   transmit_notify_request(sub, tmp);
   ast_mutex_unlock(&sub->lock);
   return -1; /* Return non-zero so that Asterisk will stop the inband indications */
}

/*!
 *  \brief  mgcp_devicestate: channel callback for device status monitoring
 *  \param  data tech/resource name of MGCP device to query
 *
 * Callback for device state management in channel subsystem
 * to obtain device status (up/down) of a specific MGCP endpoint
 *
 *  \return device status result (from devicestate.h) AST_DEVICE_INVALID (not available) or AST_DEVICE_UNKNOWN (available but unknown state)
 */
static int mgcp_devicestate(void *data)
{
   struct mgcp_gateway  *g;
   struct mgcp_endpoint *e = NULL;
   char *tmp, *endpt, *gw;
   int ret = AST_DEVICE_INVALID;

   endpt = ast_strdupa(data);
   if ((tmp = strchr(endpt, '@'))) {
      *tmp++ = '\0';
      gw = tmp;
   } else
      goto error;

   ast_mutex_lock(&gatelock);
   g = gateways;
   while (g) {
      if (strcasecmp(g->name, gw) == 0) {
         e = g->endpoints;
         break;
      }
      g = g->next;
   }

   if (!e)
      goto error;

   while (e) {
      if (strcasecmp(e->name, endpt) == 0)
         break;
      e = e->next;
   }

   if (!e)
      goto error;

   /*
    * As long as the gateway/endpoint is valid, we'll
    * assume that the device is available and its state
    * can be tracked.
    */
   ret = AST_DEVICE_UNKNOWN;

error:
   ast_mutex_unlock(&gatelock);
   return ret;
}

static char *control2str(int ind) {
   switch (ind) {
   case AST_CONTROL_HANGUP:
      return "Other end has hungup";
   case AST_CONTROL_RING:
      return "Local ring";
   case AST_CONTROL_RINGING:
      return "Remote end is ringing";
   case AST_CONTROL_ANSWER:
      return "Remote end has answered";
   case AST_CONTROL_BUSY:
      return "Remote end is busy";
   case AST_CONTROL_TAKEOFFHOOK:
      return "Make it go off hook";
   case AST_CONTROL_OFFHOOK:
      return "Line is off hook";
   case AST_CONTROL_CONGESTION:
      return "Congestion (circuits busy)";
   case AST_CONTROL_FLASH:
      return "Flash hook";
   case AST_CONTROL_WINK:
      return "Wink";
   case AST_CONTROL_OPTION:
      return "Set a low-level option";
   case AST_CONTROL_RADIO_KEY:
      return "Key Radio";
   case AST_CONTROL_RADIO_UNKEY:
      return "Un-Key Radio";
   }
   return "UNKNOWN";
}

static int mgcp_indicate(struct ast_channel *ast, int ind, const void *data, size_t datalen)
{
   struct mgcp_subchannel *sub = ast->tech_pvt;
   int res = 0;

   if (mgcpdebug) {
      ast_verbose(VERBOSE_PREFIX_3 "MGCP asked to indicate %d '%s' condition on channel %s\n",
         ind, control2str(ind), ast->name);
   }
   ast_mutex_lock(&sub->lock);
   switch(ind) {
   case AST_CONTROL_RINGING:
#ifdef DLINK_BUGGY_FIRMWARE   
      transmit_notify_request(sub, "rt");
#else
      transmit_notify_request(sub, "G/rt");
#endif      
      break;
   case AST_CONTROL_BUSY:
      transmit_notify_request(sub, "L/bz");
      break;
   case AST_CONTROL_CONGESTION:
      transmit_notify_request(sub, "G/cg");
      break;
   case AST_CONTROL_HOLD:
      ast_moh_start(ast, data, NULL);
      break;
   case AST_CONTROL_UNHOLD:
      ast_moh_stop(ast);
      break;
   case -1:
      transmit_notify_request(sub, "");
      break;
   default:
      ast_log(LOG_WARNING, "Don't know how to indicate condition %d\n", ind);
      res = -1;
   }
   ast_mutex_unlock(&sub->lock);
   return res;
}

static struct ast_channel *mgcp_new(struct mgcp_subchannel *sub, int state)
{
   struct ast_channel *tmp;
   struct mgcp_endpoint *i = sub->parent;
   int fmt;

   tmp = ast_channel_alloc(1, state, i->cid_num, i->cid_name, "MGCP/%s@%s-%d", i->name, i->parent->name, sub->id);
   if (tmp) {
      tmp->tech = &mgcp_tech;
      tmp->nativeformats = i->capability;
      if (!tmp->nativeformats)
         tmp->nativeformats = capability;
      fmt = ast_best_codec(tmp->nativeformats);
      ast_string_field_build(tmp, name, "MGCP/%s@%s-%d", i->name, i->parent->name, sub->id);
      if (sub->rtp)
         tmp->fds[0] = ast_rtp_fd(sub->rtp);
      if (i->dtmfmode & (MGCP_DTMF_INBAND | MGCP_DTMF_HYBRID)) {
         i->dsp = ast_dsp_new();
         ast_dsp_set_features(i->dsp,DSP_FEATURE_DTMF_DETECT);
         /* this is to prevent clipping of dtmf tones during dsp processing */
         ast_dsp_digitmode(i->dsp, DSP_DIGITMODE_NOQUELCH);
      } else {
         i->dsp = NULL;
      }
      if (state == AST_STATE_RING)
         tmp->rings = 1;
      tmp->writeformat = fmt;
      tmp->rawwriteformat = fmt;
      tmp->readformat = fmt;
      tmp->rawreadformat = fmt;
      tmp->tech_pvt = sub;
      if (!ast_strlen_zero(i->language))
         ast_string_field_set(tmp, language, i->language);
      if (!ast_strlen_zero(i->accountcode))
         ast_string_field_set(tmp, accountcode, i->accountcode);
      if (i->amaflags)
         tmp->amaflags = i->amaflags;
      sub->owner = tmp;
      ast_module_ref(ast_module_info->self);
      tmp->callgroup = i->callgroup;
      tmp->pickupgroup = i->pickupgroup;
      ast_string_field_set(tmp, call_forward, i->call_forward);
      ast_copy_string(tmp->context, i->context, sizeof(tmp->context));
      ast_copy_string(tmp->exten, i->exten, sizeof(tmp->exten));

      /* Don't use ast_set_callerid() here because it will
       * generate a needless NewCallerID event */
      tmp->cid.cid_num = ast_strdup(i->cid_num);
      tmp->cid.cid_ani = ast_strdup(i->cid_num);
      tmp->cid.cid_name = ast_strdup(i->cid_name);
      
      if (!i->adsi)
         tmp->adsicpe = AST_ADSI_UNAVAILABLE;
      tmp->priority = 1;
      if (sub->rtp)
         ast_jb_configure(tmp, &global_jbconf);
      if (state != AST_STATE_DOWN) {
         if (ast_pbx_start(tmp)) {
            ast_log(LOG_WARNING, "Unable to start PBX on %s\n", tmp->name);
            ast_hangup(tmp);
            tmp = NULL;
         }
      }
      /* verbose level check */
      if (option_verbose > 2) {
         ast_verbose(VERBOSE_PREFIX_3 "MGCP mgcp_new(%s) created in state: %s\n",
            tmp->name, ast_state2str(state));
      }
   } else {
      ast_log(LOG_WARNING, "Unable to allocate channel structure\n");
   }
   return tmp;
}

static char* get_sdp_by_line(char* line, char *name, int nameLen)
{
   if (strncasecmp(line, name, nameLen) == 0 && line[nameLen] == '=') {
      char* r = line + nameLen + 1;
      while (*r && (*r < 33)) ++r;
      return r;
   }
   return "";
}

static char *get_sdp(struct mgcp_request *req, char *name)
{
   int x;
   int len = strlen(name);
   char *r;

   for (x=0; x<req->lines; x++) {
      r = get_sdp_by_line(req->line[x], name, len);
      if (r[0] != '\0') return r;
   }
   return "";
}

static void sdpLineNum_iterator_init(int* iterator)
{
   *iterator = 0;
}

static char* get_sdp_iterate(int* iterator, struct mgcp_request *req, char *name)
{
   int len = strlen(name);
   char *r;
   while (*iterator < req->lines) {
      r = get_sdp_by_line(req->line[(*iterator)++], name, len);
      if (r[0] != '\0') return r;
   }
   return "";
}

static char *__get_header(struct mgcp_request *req, char *name, int *start)
{
   int x;
   int len = strlen(name);
   char *r;
   for (x=*start;x<req->headers;x++) {
      if (!strncasecmp(req->header[x], name, len) && 
          (req->header[x][len] == ':')) {
         r = req->header[x] + len + 1;
         while(*r && (*r < 33))
            r++;
         *start = x+1;
         return r;
      }
   }
   /* Don't return NULL, so get_header is always a valid pointer */
   return "";
}

static char *get_header(struct mgcp_request *req, char *name)
{
   int start = 0;
   return __get_header(req, name, &start);
}

/*! \brief get_csv: (SC:) get comma separated value */
static char *get_csv(char *c, int *len, char **next) 
{
   char *s;

   *next = NULL, *len = 0;
   if (!c) return NULL;

   while (*c && (*c < 33 || *c == ','))
      c++;

   s = c;
   while (*c && (*c >= 33 && *c != ','))
      c++, (*len)++;
   *next = c;

   if (*len == 0)
      s = NULL, *next = NULL;

   return s;
}

static struct mgcp_subchannel *find_subchannel_and_lock(char *name, int msgid, struct sockaddr_in *sin)
{
   struct mgcp_endpoint *p = NULL;
   struct mgcp_subchannel *sub = NULL;
   struct mgcp_gateway *g;
   char tmp[256] = "";
   char *at = NULL, *c;
   int found = 0;
   if (name) {
      ast_copy_string(tmp, name, sizeof(tmp));
      at = strchr(tmp, '@');
      if (!at) {
         ast_log(LOG_NOTICE, "Endpoint '%s' has no at sign!\n", name);
         return NULL;
      }
      *at++ = '\0';
   }
   ast_mutex_lock(&gatelock);
   if (at && (at[0] == '[')) {
      at++;
      c = strrchr(at, ']');
      if (c)
         *c = '\0';
   }
   g = gateways;
   while(g) {
      if ((!name || !strcasecmp(g->name, at)) && 
          (sin || g->addr.sin_addr.s_addr || g->defaddr.sin_addr.s_addr)) {
         /* Found the gateway.  If it's dynamic, save it's address -- now for the endpoint */
         if (sin && g->dynamic && name) {
            if ((g->addr.sin_addr.s_addr != sin->sin_addr.s_addr) ||
               (g->addr.sin_port != sin->sin_port)) {
               memcpy(&g->addr, sin, sizeof(g->addr));
               if (ast_ouraddrfor(&g->addr.sin_addr, &g->ourip))
                  memcpy(&g->ourip, &__ourip, sizeof(g->ourip));
               if (option_verbose > 2)
                  ast_verbose(VERBOSE_PREFIX_3 "Registered MGCP gateway '%s' at %s port %d\n", g->name, ast_inet_ntoa(g->addr.sin_addr), ntohs(g->addr.sin_port));
            }
         }
         /* not dynamic, check if the name matches */
         else if (name) {
            if (strcasecmp(g->name, at)) {
               g = g->next;
               continue;
            }
         }
         /* not dynamic, no name, check if the addr matches */
         else if (!name && sin) {
            if ((g->addr.sin_addr.s_addr != sin->sin_addr.s_addr) ||
                (g->addr.sin_port != sin->sin_port)) {
               g = g->next;
               continue;
            }
         } else {
            g = g->next;
            continue;
         }
         /* SC */
         p = g->endpoints;
         while(p) {
            if (option_debug)
               ast_log(LOG_DEBUG, "Searching on %s@%s for subchannel\n",
                  p->name, g->name);
            if (msgid) {
#if 0 /* new transport mech */
               sub = p->sub;
               do {
                  if (option_debug)
                     ast_log(LOG_DEBUG, "Searching on %s@%s-%d for subchannel with lastout: %d\n",
                        p->name, g->name, sub->id, msgid);
                  if (sub->lastout == msgid) {
                     if (option_debug)
                        ast_log(LOG_DEBUG, "Found subchannel sub%d to handle request %d sub->lastout: %d\n",
                           sub->id, msgid, sub->lastout);
                     found = 1;
                     break;
                  }
                  sub = sub->next;
               } while (sub != p->sub);
               if (found) {
                  break;
               }
#endif
               /* SC */
               sub = p->sub;
               found = 1;
               /* SC */
               break;
            } else if (name && !strcasecmp(p->name, tmp)) {
               if (option_debug)
                  ast_log(LOG_DEBUG, "Coundn't determine subchannel, assuming current master %s@%s-%d\n", 
                     p->name, g->name, p->sub->id);
               sub = p->sub;
               found = 1;
               break;
            }
            p = p->next;
         }
         if (sub && found) {
            ast_mutex_lock(&sub->lock);
            break;
         }
      }
      g = g->next;
   }
   ast_mutex_unlock(&gatelock);
   if (!sub) {
      if (name) {
         if (g)
            ast_log(LOG_NOTICE, "Endpoint '%s' not found on gateway '%s'\n", tmp, at);
         else
            ast_log(LOG_NOTICE, "Gateway '%s' (and thus its endpoint '%s') does not exist\n", at, tmp);
      } 
   }
   return sub;
}

static void parse(struct mgcp_request *req)
{
   /* Divide fields by NULL's */
   char *c;
   int f = 0;
   c = req->data;

   /* First header starts immediately */
   req->header[f] = c;
   while(*c) {
      if (*c == '\n') {
         /* We've got a new header */
         *c = 0;
#if 0
         printf("Header: %s (%d)\n", req->header[f], strlen(req->header[f]));
#endif         
         if (ast_strlen_zero(req->header[f])) {
            /* Line by itself means we're now in content */
            c++;
            break;
         }
         if (f >= MGCP_MAX_HEADERS - 1) {
            ast_log(LOG_WARNING, "Too many MGCP headers...\n");
         } else
            f++;
         req->header[f] = c + 1;
      } else if (*c == '\r') {
         /* Ignore but eliminate \r's */
         *c = 0;
      }
      c++;
   }
   /* Check for last header */
   if (!ast_strlen_zero(req->header[f])) 
      f++;
   req->headers = f;
   /* Now we process any mime content */
   f = 0;
   req->line[f] = c;
   while(*c) {
      if (*c == '\n') {
         /* We've got a new line */
         *c = 0;
#if 0
         printf("Line: %s (%d)\n", req->line[f], strlen(req->line[f]));
#endif         
         if (f >= MGCP_MAX_LINES - 1) {
            ast_log(LOG_WARNING, "Too many SDP lines...\n");
         } else
            f++;
         req->line[f] = c + 1;
      } else if (*c == '\r') {
         /* Ignore and eliminate \r's */
         *c = 0;
      }
      c++;
   }
   /* Check for last line */
   if (!ast_strlen_zero(req->line[f])) 
      f++;
   req->lines = f;
   /* Parse up the initial header */
   c = req->header[0];
   while(*c && *c < 33) c++;
   /* First the verb */
   req->verb = c;
   while(*c && (*c > 32)) c++;
   if (*c) {
      *c = '\0';
      c++;
      while(*c && (*c < 33)) c++;
      req->identifier = c;
      while(*c && (*c > 32)) c++;
      if (*c) {
         *c = '\0';
         c++;
         while(*c && (*c < 33)) c++;
         req->endpoint = c;
         while(*c && (*c > 32)) c++;
         if (*c) {
            *c = '\0';
            c++;
            while(*c && (*c < 33)) c++;
            req->version = c;
            while(*c && (*c > 32)) c++;
            while(*c && (*c < 33)) c++;
            while(*c && (*c > 32)) c++;
            *c = '\0';
         }
      }
   }
      
   if (mgcpdebug) {
      ast_verbose("Verb: '%s', Identifier: '%s', Endpoint: '%s', Version: '%s'\n",
         req->verb, req->identifier, req->endpoint, req->version);
      ast_verbose("%d headers, %d lines\n", req->headers, req->lines);
   }
   if (*c) 
      ast_log(LOG_WARNING, "Odd content, extra stuff left over ('%s')\n", c);
}

static int process_sdp(struct mgcp_subchannel *sub, struct mgcp_request *req)
{
   char *m;
   char *c;
   char *a;
   char host[258];
   int len;
   int portno;
   int peercapability, peerNonCodecCapability;
   struct sockaddr_in sin;
   char *codecs;
   struct ast_hostent ahp; struct hostent *hp;
   int codec, codec_count=0;
   int iterator;
   struct mgcp_endpoint *p = sub->parent;

   /* Get codec and RTP info from SDP */
   m = get_sdp(req, "m");
   c = get_sdp(req, "c");
   if (ast_strlen_zero(m) || ast_strlen_zero(c)) {
      ast_log(LOG_WARNING, "Insufficient information for SDP (m = '%s', c = '%s')\n", m, c);
      return -1;
   }
   if (sscanf(c, "IN IP4 %256s", host) != 1) {
      ast_log(LOG_WARNING, "Invalid host in c= line, '%s'\n", c);
      return -1;
   }
   /* XXX This could block for a long time, and block the main thread! XXX */
   hp = ast_gethostbyname(host, &ahp);
   if (!hp) {
      ast_log(LOG_WARNING, "Unable to lookup host in c= line, '%s'\n", c);
      return -1;
   }
   if (sscanf(m, "audio %d RTP/AVP %n", &portno, &len) != 1) {
      ast_log(LOG_WARNING, "Unable to determine port number for RTP in '%s'\n", m); 
      return -1;
   }
   sin.sin_family = AF_INET;
   memcpy(&sin.sin_addr, hp->h_addr, sizeof(sin.sin_addr));
   sin.sin_port = htons(portno);
   ast_rtp_set_peer(sub->rtp, &sin);
#if 0
   printf("Peer RTP is at port %s:%d\n", ast_inet_ntoa(sin.sin_addr), ntohs(sin.sin_port));
#endif   
   /* Scan through the RTP payload types specified in a "m=" line: */
   ast_rtp_pt_clear(sub->rtp);
   codecs = ast_strdupa(m + len);
   while (!ast_strlen_zero(codecs)) {
      if (sscanf(codecs, "%d%n", &codec, &len) != 1) {
         if (codec_count)
            break;
         ast_log(LOG_WARNING, "Error in codec string '%s' at '%s'\n", m, codecs);
         return -1;
      }
      ast_rtp_set_m_type(sub->rtp, codec);
      codec_count++;
      codecs += len;
   }

   /* Next, scan through each "a=rtpmap:" line, noting each */
   /* specified RTP payload type (with corresponding MIME subtype): */
   sdpLineNum_iterator_init(&iterator);
   while ((a = get_sdp_iterate(&iterator, req, "a"))[0] != '\0') {
      char* mimeSubtype = ast_strdupa(a); /* ensures we have enough space */
      if (sscanf(a, "rtpmap: %u %[^/]/", &codec, mimeSubtype) != 2)
         continue;
      /* Note: should really look at the 'freq' and '#chans' params too */
      ast_rtp_set_rtpmap_type(sub->rtp, codec, "audio", mimeSubtype, 0);
   }

   /* Now gather all of the codecs that were asked for: */
   ast_rtp_get_current_formats(sub->rtp, &peercapability, &peerNonCodecCapability);
   p->capability = capability & peercapability;
   if (mgcpdebug) {
      ast_verbose("Capabilities: us - %d, them - %d, combined - %d\n",
         capability, peercapability, p->capability);
      ast_verbose("Non-codec capabilities: us - %d, them - %d, combined - %d\n",
         nonCodecCapability, peerNonCodecCapability, p->nonCodecCapability);
   }
   if (!p->capability) {
      ast_log(LOG_WARNING, "No compatible codecs!\n");
      return -1;
   }
   return 0;
}

static int add_header(struct mgcp_request *req, char *var, char *value)
{
   if (req->len >= sizeof(req->data) - 4) {
      ast_log(LOG_WARNING, "Out of space, can't add anymore\n");
      return -1;
   }
   if (req->lines) {
      ast_log(LOG_WARNING, "Can't add more headers when lines have been added\n");
      return -1;
   }
   req->header[req->headers] = req->data + req->len;
   snprintf(req->header[req->headers], sizeof(req->data) - req->len, "%s: %s\r\n", var, value);
   req->len += strlen(req->header[req->headers]);
   if (req->headers < MGCP_MAX_HEADERS)
      req->headers++;
   else {
      ast_log(LOG_WARNING, "Out of header space\n");
      return -1;
   }
   return 0;   
}

static int add_line(struct mgcp_request *req, char *line)
{
   if (req->len >= sizeof(req->data) - 4) {
      ast_log(LOG_WARNING, "Out of space, can't add anymore\n");
      return -1;
   }
   if (!req->lines) {
      /* Add extra empty return */
      snprintf(req->data + req->len, sizeof(req->data) - req->len, "\r\n");
      req->len += strlen(req->data + req->len);
   }
   req->line[req->lines] = req->data + req->len;
   snprintf(req->line[req->lines], sizeof(req->data) - req->len, "%s", line);
   req->len += strlen(req->line[req->lines]);
   if (req->lines < MGCP_MAX_LINES)
      req->lines++;
   else {
      ast_log(LOG_WARNING, "Out of line space\n");
      return -1;
   }
   return 0;   
}

static int init_resp(struct mgcp_request *req, char *resp, struct mgcp_request *orig, char *resprest)
{
   /* Initialize a response */
   if (req->headers || req->len) {
      ast_log(LOG_WARNING, "Request already initialized?!?\n");
      return -1;
   }
   req->header[req->headers] = req->data + req->len;
   snprintf(req->header[req->headers], sizeof(req->data) - req->len, "%s %s %s\r\n", resp, orig->identifier, resprest);
   req->len += strlen(req->header[req->headers]);
   if (req->headers < MGCP_MAX_HEADERS)
      req->headers++;
   else
      ast_log(LOG_WARNING, "Out of header space\n");
   return 0;
}

static int init_req(struct mgcp_endpoint *p, struct mgcp_request *req, char *verb)
{
   /* Initialize a response */
   if (req->headers || req->len) {
      ast_log(LOG_WARNING, "Request already initialized?!?\n");
      return -1;
   }
   req->header[req->headers] = req->data + req->len;
   /* check if we need brackets around the gw name */
   if (p->parent->isnamedottedip)
      snprintf(req->header[req->headers], sizeof(req->data) - req->len, "%s %d %s@[%s] MGCP 1.0\r\n", verb, oseq, p->name, p->parent->name);
   else
      snprintf(req->header[req->headers], sizeof(req->data) - req->len, "%s %d %s@%s MGCP 1.0\r\n", verb, oseq, p->name, p->parent->name);
   req->len += strlen(req->header[req->headers]);
   if (req->headers < MGCP_MAX_HEADERS)
      req->headers++;
   else
      ast_log(LOG_WARNING, "Out of header space\n");
   return 0;
}


static int respprep(struct mgcp_request *resp, struct mgcp_endpoint *p, char *msg, struct mgcp_request *req, char *msgrest)
{
   memset(resp, 0, sizeof(*resp));
   init_resp(resp, msg, req, msgrest);
   return 0;
}

static int reqprep(struct mgcp_request *req, struct mgcp_endpoint *p, char *verb)
{
   memset(req, 0, sizeof(struct mgcp_request));
   oseq++;
   if (oseq > 999999999)
      oseq = 1;
   init_req(p, req, verb);
   return 0;
}

static int transmit_response(struct mgcp_subchannel *sub, char *msg, struct mgcp_request *req, char *msgrest)
{
   struct mgcp_request resp;
   struct mgcp_endpoint *p = sub->parent;
   struct mgcp_response *mgr;

   respprep(&resp, p, msg, req, msgrest);
   mgr = malloc(sizeof(struct mgcp_response) + resp.len + 1);
   if (mgr) {
      /* Store MGCP response in case we have to retransmit */
      memset(mgr, 0, sizeof(struct mgcp_response));
      sscanf(req->identifier, "%d", &mgr->seqno);
      time(&mgr->whensent);
      mgr->len = resp.len;
      memcpy(mgr->buf, resp.data, resp.len);
      mgr->buf[resp.len] = '\0';
      mgr->next = p->parent->responses;
      p->parent->responses = mgr;
   }
   return send_response(sub, &resp);
}


static int add_sdp(struct mgcp_request *resp, struct mgcp_subchannel *sub, struct ast_rtp *rtp)
{
   int len;
   int codec;
   char costr[80];
   struct sockaddr_in sin;
   char v[256];
   char s[256];
   char o[256];
   char c[256];
   char t[256];
   char m[256] = "";
   char a[1024] = "";
   int x;
   struct sockaddr_in dest;
   struct mgcp_endpoint *p = sub->parent;
   /* XXX We break with the "recommendation" and send our IP, in order that our
          peer doesn't have to ast_gethostbyname() us XXX */
   len = 0;
   if (!sub->rtp) {
      ast_log(LOG_WARNING, "No way to add SDP without an RTP structure\n");
      return -1;
   }
   ast_rtp_get_us(sub->rtp, &sin);
   if (rtp) {
      ast_rtp_get_peer(rtp, &dest);
   } else {
      if (sub->tmpdest.sin_addr.s_addr) {
         dest.sin_addr = sub->tmpdest.sin_addr;
         dest.sin_port = sub->tmpdest.sin_port;
         /* Reset temporary destination */
         memset(&sub->tmpdest, 0, sizeof(sub->tmpdest));
      } else {
         dest.sin_addr = p->parent->ourip;
         dest.sin_port = sin.sin_port;
      }
   }
   if (mgcpdebug) {
      ast_verbose("We're at %s port %d\n", ast_inet_ntoa(p->parent->ourip), ntohs(sin.sin_port));
   }
   snprintf(v, sizeof(v), "v=0\r\n");
   snprintf(o, sizeof(o), "o=root %d %d IN IP4 %s\r\n", getpid(), getpid(), ast_inet_ntoa(dest.sin_addr));
   snprintf(s, sizeof(s), "s=session\r\n");
   snprintf(c, sizeof(c), "c=IN IP4 %s\r\n", ast_inet_ntoa(dest.sin_addr));
   snprintf(t, sizeof(t), "t=0 0\r\n");
   snprintf(m, sizeof(m), "m=audio %d RTP/AVP", ntohs(dest.sin_port));
   for (x = 1; x <= AST_FORMAT_MAX_AUDIO; x <<= 1) {
      if (p->capability & x) {
         if (mgcpdebug) {
            ast_verbose("Answering with capability %d\n", x);
         }
         codec = ast_rtp_lookup_code(sub->rtp, 1, x);
         if (codec > -1) {
            snprintf(costr, sizeof(costr), " %d", codec);
            strncat(m, costr, sizeof(m) - strlen(m) - 1);
            snprintf(costr, sizeof(costr), "a=rtpmap:%d %s/8000\r\n", codec, ast_rtp_lookup_mime_subtype(1, x, 0));
            strncat(a, costr, sizeof(a) - strlen(a) - 1);
         }
      }
   }
   for (x = 1; x <= AST_RTP_MAX; x <<= 1) {
      if (p->nonCodecCapability & x) {
         if (mgcpdebug) {
            ast_verbose("Answering with non-codec capability %d\n", x);
         }
         codec = ast_rtp_lookup_code(sub->rtp, 0, x);
         if (codec > -1) {
            snprintf(costr, sizeof(costr), " %d", codec);
            strncat(m, costr, sizeof(m) - strlen(m) - 1);
            snprintf(costr, sizeof(costr), "a=rtpmap:%d %s/8000\r\n", codec, ast_rtp_lookup_mime_subtype(0, x, 0));
            strncat(a, costr, sizeof(a) - strlen(a) - 1);
            if (x == AST_RTP_DTMF) {
               /* Indicate we support DTMF...  Not sure about 16,
                  but MSN supports it so dang it, we will too... */
               snprintf(costr, sizeof costr, "a=fmtp:%d 0-16\r\n", codec);
               strncat(a, costr, sizeof(a) - strlen(a) - 1);
            }
         }
      }
   }
   strncat(m, "\r\n", sizeof(m) - strlen(m) - 1);
   len = strlen(v) + strlen(s) + strlen(o) + strlen(c) + strlen(t) + strlen(m) + strlen(a);
   snprintf(costr, sizeof(costr), "%d", len);
   add_line(resp, v);
   add_line(resp, o);
   add_line(resp, s);
   add_line(resp, c);
   add_line(resp, t);
   add_line(resp, m);
   add_line(resp, a);
   return 0;
}

static int transmit_modify_with_sdp(struct mgcp_subchannel *sub, struct ast_rtp *rtp, int codecs)
{
   struct mgcp_request resp;
   char local[256];
   char tmp[80];
   int x;
   int capability;
   struct mgcp_endpoint *p = sub->parent;

   capability = p->capability;
   if (codecs)
      capability = codecs;
   if (ast_strlen_zero(sub->cxident) && rtp) {
      /* We don't have a CXident yet, store the destination and
         wait a bit */
      ast_rtp_get_peer(rtp, &sub->tmpdest);
      return 0;
   }
   snprintf(local, sizeof(local), "p:20");
   for (x=1;x<= AST_FORMAT_MAX_AUDIO; x <<= 1) {
      if (p->capability & x) {
         snprintf(tmp, sizeof(tmp), ", a:%s", ast_rtp_lookup_mime_subtype(1, x, 0));
         strncat(local, tmp, sizeof(local) - strlen(local) - 1);
      }
   }
   reqprep(&resp, p, "MDCX");
   add_header(&resp, "C", sub->callid);
   add_header(&resp, "L", local);
   add_header(&resp, "M", mgcp_cxmodes[sub->cxmode]);
   /* X header should not be sent. kept for compatibility */
   add_header(&resp, "X", sub->txident);
   add_header(&resp, "I", sub->cxident);
   /*add_header(&resp, "S", "");*/
   add_sdp(&resp, sub, rtp);
   /* fill in new fields */
   resp.cmd = MGCP_CMD_MDCX;
   resp.trid = oseq;
   return send_request(p, sub, &resp, oseq); /* SC */
}

static int transmit_connect_with_sdp(struct mgcp_subchannel *sub, struct ast_rtp *rtp)
{
   struct mgcp_request resp;
   char local[256];
   char tmp[80];
   int x;
   struct mgcp_endpoint *p = sub->parent;

   snprintf(local, sizeof(local), "p:20");
   for (x=1;x<= AST_FORMAT_MAX_AUDIO; x <<= 1) {
      if (p->capability & x) {
         snprintf(tmp, sizeof(tmp), ", a:%s", ast_rtp_lookup_mime_subtype(1, x, 0));
         strncat(local, tmp, sizeof(local) - strlen(local) - 1);
      }
   }
   if (mgcpdebug) {
      ast_verbose(VERBOSE_PREFIX_3 "Creating connection for %s@%s-%d in cxmode: %s callid: %s\n", 
         p->name, p->parent->name, sub->id, mgcp_cxmodes[sub->cxmode], sub->callid);
   }
   reqprep(&resp, p, "CRCX");
   add_header(&resp, "C", sub->callid);
   add_header(&resp, "L", local);
   add_header(&resp, "M", mgcp_cxmodes[sub->cxmode]);
   /* X header should not be sent. kept for compatibility */
   add_header(&resp, "X", sub->txident);
   /*add_header(&resp, "S", "");*/
   add_sdp(&resp, sub, rtp);
   /* fill in new fields */
   resp.cmd = MGCP_CMD_CRCX;
   resp.trid = oseq;
   return send_request(p, sub, &resp, oseq);  /* SC */
}

static int transmit_notify_request(struct mgcp_subchannel *sub, char *tone)
{
   struct mgcp_request resp;
   struct mgcp_endpoint *p = sub->parent;

   if (mgcpdebug) {
      ast_verbose(VERBOSE_PREFIX_3 "MGCP Asked to indicate tone: %s on  %s@%s-%d in cxmode: %s\n", 
         tone, p->name, p->parent->name, sub->id, mgcp_cxmodes[sub->cxmode]);
   }
   ast_copy_string(p->curtone, tone, sizeof(p->curtone));
   reqprep(&resp, p, "RQNT");
   add_header(&resp, "X", p->rqnt_ident); /* SC */
   switch (p->hookstate) {
   case MGCP_ONHOOK:
      add_header(&resp, "R", "L/hd(N)");
      break;
   case MGCP_OFFHOOK:
      add_header(&resp, "R", (sub->rtp && (p->dtmfmode & MGCP_DTMF_INBAND)) ? "L/hu(N),L/hf(N)" : "L/hu(N),L/hf(N),D/[0-9#*](N)");
      break;
   }
   if (!ast_strlen_zero(tone)) {
      add_header(&resp, "S", tone);
   }
   /* fill in new fields */
   resp.cmd = MGCP_CMD_RQNT;
   resp.trid = oseq;
   return send_request(p, NULL, &resp, oseq); /* SC */
}

static int transmit_notify_request_with_callerid(struct mgcp_subchannel *sub, char *tone, char *callernum, char *callername)
{
   struct mgcp_request resp;
   char tone2[256];
   char *l, *n;
   time_t t;
   struct tm tm;
   struct mgcp_endpoint *p = sub->parent;
   
   time(&t);
   localtime_r(&t,&tm);
   n = callername;
   l = callernum;
   if (!n)
      n = "";
   if (!l)
      l = "";

   /* Keep track of last callerid for blacklist and callreturn */
   ast_copy_string(p->lastcallerid, l, sizeof(p->lastcallerid));

   snprintf(tone2, sizeof(tone2), "%s,L/ci(%02d/%02d/%02d/%02d,%s,%s)", tone, 
      tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, l, n);
   ast_copy_string(p->curtone, tone, sizeof(p->curtone));
   reqprep(&resp, p, "RQNT");
   add_header(&resp, "X", p->rqnt_ident); /* SC */
   switch (p->hookstate) {
   case MGCP_ONHOOK:
      add_header(&resp, "R", "L/hd(N)");
      break;
   case MGCP_OFFHOOK:
      add_header(&resp, "R",  (sub->rtp && (p->dtmfmode & MGCP_DTMF_INBAND)) ? "L/hu(N),L/hf(N)" : "L/hu(N),L/hf(N),D/[0-9#*](N)");
      break;
   }
   if (!ast_strlen_zero(tone2)) {
      add_header(&resp, "S", tone2);
   }
   if (mgcpdebug) {
      ast_verbose(VERBOSE_PREFIX_3 "MGCP Asked to indicate tone: %s on  %s@%s-%d in cxmode: %s\n", 
         tone2, p->name, p->parent->name, sub->id, mgcp_cxmodes[sub->cxmode]);
   }
   /* fill in new fields */
   resp.cmd = MGCP_CMD_RQNT;
   resp.trid = oseq;
   return send_request(p, NULL, &resp, oseq);  /* SC */
}

static int transmit_modify_request(struct mgcp_subchannel *sub)
{
   struct mgcp_request resp;
   struct mgcp_endpoint *p = sub->parent;

   if (ast_strlen_zero(sub->cxident)) {
      /* We don't have a CXident yet, store the destination and
         wait a bit */
      return 0;
   }
   if (mgcpdebug) {
      ast_verbose(VERBOSE_PREFIX_3 "Modified %s@%s-%d with new mode: %s on callid: %s\n", 
         p->name, p->parent->name, sub->id, mgcp_cxmodes[sub->cxmode], sub->callid);
   }
   reqprep(&resp, p, "MDCX");
   add_header(&resp, "C", sub->callid);
   add_header(&resp, "M", mgcp_cxmodes[sub->cxmode]);
   /* X header should not be sent. kept for compatibility */
   add_header(&resp, "X", sub->txident);
   add_header(&resp, "I", sub->cxident);
   switch (sub->parent->hookstate) {
   case MGCP_ONHOOK:
      add_header(&resp, "R", "L/hd(N)");
      break;
   case MGCP_OFFHOOK:
      add_header(&resp, "R",  (sub->rtp && (p->dtmfmode & MGCP_DTMF_INBAND)) ? "L/hu(N), L/hf(N)" : "L/hu(N),L/hf(N),D/[0-9#*](N)");
      break;
   }
   /* fill in new fields */
   resp.cmd = MGCP_CMD_MDCX;
   resp.trid = oseq;
   return send_request(p, sub, &resp, oseq); /* SC */
}


static int transmit_audit_endpoint(struct mgcp_endpoint *p)
{
   struct mgcp_request resp;
   reqprep(&resp, p, "AUEP");
   /* removed unknown param VS */
   /*add_header(&resp, "F", "A,R,D,S,X,N,I,T,O,ES,E,MD,M");*/
   add_header(&resp, "F", "A");
   /* fill in new fields */
   resp.cmd = MGCP_CMD_AUEP;
   resp.trid = oseq;
   return send_request(p, NULL, &resp, oseq);  /* SC */
}

static int transmit_connection_del(struct mgcp_subchannel *sub)
{
   struct mgcp_endpoint *p = sub->parent;
   struct mgcp_request resp;

   if (mgcpdebug) {
      ast_verbose(VERBOSE_PREFIX_3 "Delete connection %s %s@%s-%d with new mode: %s on callid: %s\n", 
         sub->cxident, p->name, p->parent->name, sub->id, mgcp_cxmodes[sub->cxmode], sub->callid);
   }
   reqprep(&resp, p, "DLCX");
   /* check if call id is avail */
   if (sub->callid[0])
      add_header(&resp, "C", sub->callid);
   /* X header should not be sent. kept for compatibility */
   add_header(&resp, "X", sub->txident);
   /* check if cxident is avail */
   if (sub->cxident[0])
      add_header(&resp, "I", sub->cxident);
   /* fill in new fields */
   resp.cmd = MGCP_CMD_DLCX;
   resp.trid = oseq;
   return send_request(p, sub, &resp, oseq);  /* SC */
}

static int transmit_connection_del_w_params(struct mgcp_endpoint *p, char *callid, char *cxident)
{
   struct mgcp_request resp;

   if (mgcpdebug) {
      ast_verbose(VERBOSE_PREFIX_3 "Delete connection %s %s@%s on callid: %s\n", 
         cxident ? cxident : "", p->name, p->parent->name, callid ? callid : "");
   }
   reqprep(&resp, p, "DLCX");
   /* check if call id is avail */
   if (callid && *callid)
      add_header(&resp, "C", callid);
   /* check if cxident is avail */
   if (cxident && *cxident)
      add_header(&resp, "I", cxident);
   /* fill in new fields */
   resp.cmd = MGCP_CMD_DLCX;
   resp.trid = oseq;
   return send_request(p, p->sub, &resp, oseq);
}

/*! \brief  dump_cmd_queues: (SC:) cleanup pending commands */
static void dump_cmd_queues(struct mgcp_endpoint *p, struct mgcp_subchannel *sub) 
{
   struct mgcp_request *t, *q;

   if (p) {
      ast_mutex_lock(&p->rqnt_queue_lock);
      for (q = p->rqnt_queue; q; t = q->next, free(q), q=t);
      p->rqnt_queue = NULL;
      ast_mutex_unlock(&p->rqnt_queue_lock);

      ast_mutex_lock(&p->cmd_queue_lock);
      for (q = p->cmd_queue; q; t = q->next, free(q), q=t);
      p->cmd_queue = NULL;
      ast_mutex_unlock(&p->cmd_queue_lock);

      ast_mutex_lock(&p->sub->cx_queue_lock);
      for (q = p->sub->cx_queue; q; t = q->next, free(q), q=t);
      p->sub->cx_queue = NULL;
      ast_mutex_unlock(&p->sub->cx_queue_lock);

      ast_mutex_lock(&p->sub->next->cx_queue_lock);
      for (q = p->sub->next->cx_queue; q; t = q->next, free(q), q=t);
      p->sub->next->cx_queue = NULL;
      ast_mutex_unlock(&p->sub->next->cx_queue_lock);
   } else if (sub) {
      ast_mutex_lock(&sub->cx_queue_lock);
      for (q = sub->cx_queue; q; t = q->next, free(q), q=t);
      sub->cx_queue = NULL;
      ast_mutex_unlock(&sub->cx_queue_lock);
   }
}


/*! \brief  find_command: (SC:) remove command transaction from queue */
static struct mgcp_request *find_command(struct mgcp_endpoint *p, struct mgcp_subchannel *sub,
                                         struct mgcp_request **queue, ast_mutex_t *l, int ident)
{
   struct mgcp_request *prev, *req;

   ast_mutex_lock(l);
   for (prev = NULL, req = *queue; req; prev = req, req = req->next) {
      if (req->trid == ident) {
         /* remove from queue */
         if (!prev)
            *queue = req->next;
         else
            prev->next = req->next;

         /* send next pending command */
         if (*queue) {
            if (mgcpdebug) {
               ast_verbose("Posting Queued Request:\n%s to %s:%d\n", (*queue)->data, 
                  ast_inet_ntoa(p->parent->addr.sin_addr), ntohs(p->parent->addr.sin_port));
            }

            mgcp_postrequest(p, sub, (*queue)->data, (*queue)->len, (*queue)->trid);
         }
         break;
      }
   }
   ast_mutex_unlock(l);
   return req;
}

/* modified for new transport mechanism */
static void handle_response(struct mgcp_endpoint *p, struct mgcp_subchannel *sub,  
                            int result, unsigned int ident, struct mgcp_request *resp)
{
   char *c;
   struct mgcp_request *req;
   struct mgcp_gateway *gw = p->parent;

   if (result < 200) {
      /* provisional response */
      return;
   }

   if (p->slowsequence) 
      req = find_command(p, sub, &p->cmd_queue, &p->cmd_queue_lock, ident);
   else if (sub)
      req = find_command(p, sub, &sub->cx_queue, &sub->cx_queue_lock, ident);
   else if (!(req = find_command(p, sub, &p->rqnt_queue, &p->rqnt_queue_lock, ident)))
      req = find_command(p, sub, &p->cmd_queue, &p->cmd_queue_lock, ident);

   if (!req) {
      if (option_verbose > 2) {
         ast_verbose(VERBOSE_PREFIX_3 "No command found on [%s] for transaction %d. Ignoring...\n", 
            gw->name, ident);
      }
      return;
   }

   if (p && (result >= 400) && (result <= 599)) {
      switch (result) {
      case 401:
         p->hookstate = MGCP_OFFHOOK;
         break;
      case 402:
         p->hookstate = MGCP_ONHOOK;
         break;
      case 406:
         ast_log(LOG_NOTICE, "Transaction %d timed out\n", ident);
         break;
      case 407:
         ast_log(LOG_NOTICE, "Transaction %d aborted\n", ident);
         break;
      }
      if (sub) {
         if (sub->owner) {
            ast_log(LOG_NOTICE, "Terminating on result %d from %s@%s-%d\n", 
               result, p->name, p->parent->name, sub ? sub->id:-1);
            mgcp_queue_hangup(sub);
         }
      } else {
         if (p->sub->next->owner) {
            ast_log(LOG_NOTICE, "Terminating on result %d from %s@%s-%d\n", 
               result, p->name, p->parent->name, sub ? sub->id:-1);
            mgcp_queue_hangup(p->sub);
         }

         if (p->sub->owner) {
            ast_log(LOG_NOTICE, "Terminating on result %d from %s@%s-%d\n", 
               result, p->name, p->parent->name, sub ? sub->id:-1);
            mgcp_queue_hangup(p->sub);
         }

         dump_cmd_queues(p, NULL);
      }
   }

   if (resp) {
      if (req->cmd == MGCP_CMD_CRCX) {
         if ((c = get_header(resp, "I"))) {
            if (!ast_strlen_zero(c) && sub) {
               /* if we are hanging up do not process this conn. */
               if (sub->owner) {
                  if (!ast_strlen_zero(sub->cxident)) {
                     if (strcasecmp(c, sub->cxident)) {
                        ast_log(LOG_WARNING, "Subchannel already has a cxident. sub->cxident: %s requested %s\n", sub->cxident, c);
                     }
                  }
                  ast_copy_string(sub->cxident, c, sizeof(sub->cxident));
                  if (sub->tmpdest.sin_addr.s_addr) {
                     transmit_modify_with_sdp(sub, NULL, 0);
                  }
               } else {
                  /* XXX delete this one
                     callid and conn id may already be lost. 
                     so the following del conn may have a side effect of 
                     cleaning up the next subchannel */
                  transmit_connection_del(sub);
               }
            }
         }
      }

      if (req->cmd == MGCP_CMD_AUEP) {
         /* check stale connection ids */
         if ((c = get_header(resp, "I"))) {
            char *v, *n;
            int len;
            while ((v = get_csv(c, &len, &n))) {
               if (len) {
                  if (strncasecmp(v, p->sub->cxident, len) &&
                      strncasecmp(v, p->sub->next->cxident, len)) {
                     /* connection id not found. delete it */
                     char cxident[80] = "";

                     if (len > (sizeof(cxident) - 1))
                        len = sizeof(cxident) - 1;
                     ast_copy_string(cxident, v, len);
                     if (option_verbose > 2) {
                        ast_verbose(VERBOSE_PREFIX_3 "Non existing connection id %s on %s@%s \n", 
                               cxident, p->name, gw->name);
                     }
                     transmit_connection_del_w_params(p, NULL, cxident);
                  }
               }
               c = n;
            }
         }

         /* Try to determine the hookstate returned from an audit endpoint command */
         if ((c = get_header(resp, "ES"))) {
            if (!ast_strlen_zero(c)) {
               if (strstr(c, "hu")) {
                  if (p->hookstate != MGCP_ONHOOK) {
                     /* XXX cleanup if we think we are offhook XXX */
                     if ((p->sub->owner || p->sub->next->owner ) && 
                         p->hookstate == MGCP_OFFHOOK)
                        mgcp_queue_hangup(sub);
                     p->hookstate = MGCP_ONHOOK;

                     /* update the requested events according to the new hookstate */
                     transmit_notify_request(p->sub, "");

                     /* verbose level check */
                     if (option_verbose > 2) {
                        ast_verbose(VERBOSE_PREFIX_3 "Setting hookstate of %s@%s to ONHOOK\n", p->name, gw->name);
                     }
                  }
               } else if (strstr(c, "hd")) {
                  if (p->hookstate != MGCP_OFFHOOK) {
                     p->hookstate = MGCP_OFFHOOK;

                     /* update the requested events according to the new hookstate */
                     transmit_notify_request(p->sub, "");

                     /* verbose level check */
                     if (option_verbose > 2) {
                        ast_verbose(VERBOSE_PREFIX_3 "Setting hookstate of %s@%s to OFFHOOK\n", p->name, gw->name);
                     }
                  }
               }
            }
         }
      }

      if (resp && resp->lines) {
         /* do not process sdp if we are hanging up. this may be a late response */
         if (sub && sub->owner) {
            if (!sub->rtp)
               start_rtp(sub);
            if (sub->rtp)
               process_sdp(sub, resp);
         }
      }
   }

   free(req);
}

static void start_rtp(struct mgcp_subchannel *sub)
{
   ast_mutex_lock(&sub->lock);
   /* check again to be on the safe side */
   if (sub->rtp) {
      ast_rtp_destroy(sub->rtp);
      sub->rtp = NULL;
   }
   /* Allocate the RTP now */
   sub->rtp = ast_rtp_new_with_bindaddr(sched, io, 1, 0, bindaddr.sin_addr);
   if (sub->rtp && sub->owner)
      sub->owner->fds[0] = ast_rtp_fd(sub->rtp);
   if (sub->rtp)
      ast_rtp_setnat(sub->rtp, sub->nat);
#if 0
   ast_rtp_set_callback(p->rtp, rtpready);
   ast_rtp_set_data(p->rtp, p);
#endif      
   /* Make a call*ID */
        snprintf(sub->callid, sizeof(sub->callid), "%08lx%s", ast_random(), sub->txident);
   /* Transmit the connection create */
   transmit_connect_with_sdp(sub, NULL);
   ast_mutex_unlock(&sub->lock);
}

static void *mgcp_ss(void *data)
{
   struct ast_channel *chan = data;
   struct mgcp_subchannel *sub = chan->tech_pvt;
   struct mgcp_endpoint *p = sub->parent;
   char exten[AST_MAX_EXTENSION] = "";
   int len = 0;
   int timeout = firstdigittimeout;
   int res;
   int getforward = 0;

   while(len < AST_MAX_EXTENSION-1) {
      res = ast_waitfordigit(chan, timeout);
      timeout = 0;
      if (res < 0) {
         if (option_debug)
            ast_log(LOG_DEBUG, "waitfordigit returned < 0...\n");
         /*res = tone_zone_play_tone(p->subs[index].zfd, -1);*/
         ast_indicate(chan, -1);
         ast_hangup(chan);
         return NULL;
      } else if (res) {
         exten[len++]=res;
         exten[len] = '\0';
      }
      if (!ast_ignore_pattern(chan->context, exten)) {
         /*res = tone_zone_play_tone(p->subs[index].zfd, -1);*/
         ast_indicate(chan, -1);
      } else {
         /* XXX Redundant?  We should already be playing dialtone */
         /*tone_zone_play_tone(p->subs[index].zfd, ZT_TONE_DIALTONE);*/
         transmit_notify_request(sub, "L/dl");
      }
      if (ast_exists_extension(chan, chan->context, exten, 1, p->cid_num)) {
         if (!res || !ast_matchmore_extension(chan, chan->context, exten, 1, p->cid_num)) {
            if (getforward) {
               /* Record this as the forwarding extension */
               ast_copy_string(p->call_forward, exten, sizeof(p->call_forward)); 
               if (option_verbose > 2) {
                  ast_verbose(VERBOSE_PREFIX_3 "Setting call forward to '%s' on channel %s\n", 
                     p->call_forward, chan->name);
               }
               /*res = tone_zone_play_tone(p->subs[index].zfd, ZT_TONE_DIALRECALL);*/
               transmit_notify_request(sub, "L/sl");
               if (res)
                  break;
               usleep(500000);
               /*res = tone_zone_play_tone(p->subs[index].zfd, -1);*/
               ast_indicate(chan, -1);
               sleep(1);
               memset(exten, 0, sizeof(exten));
               /*res = tone_zone_play_tone(p->subs[index].zfd, ZT_TONE_DIALTONE);*/
               transmit_notify_request(sub, "L/dl");
               len = 0;
               getforward = 0;
            } else {
               /*res = tone_zone_play_tone(p->subs[index].zfd, -1);*/
               ast_indicate(chan, -1);
               ast_copy_string(chan->exten, exten, sizeof(chan->exten));
               ast_set_callerid(chan,
                  p->hidecallerid ? "" : p->cid_num,
                  p->hidecallerid ? "" : p->cid_name,
                  chan->cid.cid_ani ? NULL : p->cid_num);
               ast_setstate(chan, AST_STATE_RING);
               /*zt_enable_ec(p);*/
               if (p->dtmfmode & MGCP_DTMF_HYBRID) {
                  p->dtmfmode |= MGCP_DTMF_INBAND;
                  ast_indicate(chan, -1);
               }
               res = ast_pbx_run(chan);
               if (res) {
                  ast_log(LOG_WARNING, "PBX exited non-zero\n");
                  /*res = tone_zone_play_tone(p->subs[index].zfd, ZT_TONE_CONGESTION);*/
                  /*transmit_notify_request(p, "nbz", 1);*/
                  transmit_notify_request(sub, "G/cg");
               }
               return NULL;
            }
         } else {
            /* It's a match, but they just typed a digit, and there is an ambiguous match,
               so just set the timeout to matchdigittimeout and wait some more */
            timeout = matchdigittimeout;
         }
      } else if (res == 0) {
         if (option_debug)
            ast_log(LOG_DEBUG, "not enough digits (and no ambiguous match)...\n");
         /*res = tone_zone_play_tone(p->subs[index].zfd, ZT_TONE_CONGESTION);*/
         transmit_notify_request(sub, "G/cg");
         /*zt_wait_event(p->subs[index].zfd);*/
         ast_hangup(chan);
         return NULL;
      } else if (p->hascallwaiting && p->callwaiting && !strcmp(exten, "*70")) {
         if (option_verbose > 2) {
            ast_verbose(VERBOSE_PREFIX_3 "Disabling call waiting on %s\n", chan->name);
         }
         /* Disable call waiting if enabled */
         p->callwaiting = 0;
         /*res = tone_zone_play_tone(p->subs[index].zfd, ZT_TONE_DIALRECALL);*/
         transmit_notify_request(sub, "L/sl");
         len = 0;
         memset(exten, 0, sizeof(exten));
         timeout = firstdigittimeout;
      } else if (!strcmp(exten,ast_pickup_ext())) {
         /* Scan all channels and see if any there
          * ringing channqels with that have call groups
          * that equal this channels pickup group  
          */
         if (ast_pickup_call(chan)) {
            ast_log(LOG_WARNING, "No call pickup possible...\n");
            /*res = tone_zone_play_tone(p->subs[index].zfd, ZT_TONE_CONGESTION);*/
            transmit_notify_request(sub, "G/cg");
         }
         ast_hangup(chan);
         return NULL;
      } else if (!p->hidecallerid && !strcmp(exten, "*67")) {
         if (option_verbose > 2) {
            ast_verbose(VERBOSE_PREFIX_3 "Disabling Caller*ID on %s\n", chan->name);
         }
         /* Disable Caller*ID if enabled */
         p->hidecallerid = 1;
         ast_set_callerid(chan, "", "", NULL);
         /*res = tone_zone_play_tone(p->subs[index].zfd, ZT_TONE_DIALRECALL);*/
         transmit_notify_request(sub, "L/sl");
         len = 0;
         memset(exten, 0, sizeof(exten));
         timeout = firstdigittimeout;
      } else if (p->callreturn && !strcmp(exten, "*69")) {
         res = 0;
         if (!ast_strlen_zero(p->lastcallerid)) {
            res = ast_say_digit_str(chan, p->lastcallerid, "", chan->language);
         }
         if (!res)
            /*res = tone_zone_play_tone(p->subs[index].zfd, ZT_TONE_DIALRECALL);*/
            transmit_notify_request(sub, "L/sl");
         break;
      } else if (!strcmp(exten, "*78")) {
         /* Do not disturb */
         if (option_verbose > 2) {
            ast_verbose(VERBOSE_PREFIX_3 "Enabled DND on channel %s\n", chan->name);
         }
         /*res = tone_zone_play_tone(p->subs[index].zfd, ZT_TONE_DIALRECALL);*/
         transmit_notify_request(sub, "L/sl");
         p->dnd = 1;
         getforward = 0;
         memset(exten, 0, sizeof(exten));
         len = 0;
      } else if (!strcmp(exten, "*79")) {
         /* Do not disturb */
         if (option_verbose > 2) {
            ast_verbose(VERBOSE_PREFIX_3 "Disabled DND on channel %s\n", chan->name);
         }
         /*res = tone_zone_play_tone(p->subs[index].zfd, ZT_TONE_DIALRECALL);*/
         transmit_notify_request(sub, "L/sl");
         p->dnd = 0;
         getforward = 0;
         memset(exten, 0, sizeof(exten));
         len = 0;
      } else if (p->cancallforward && !strcmp(exten, "*72")) {
         /*res = tone_zone_play_tone(p->subs[index].zfd, ZT_TONE_DIALRECALL);*/
         transmit_notify_request(sub, "L/sl");
         getforward = 1;
         memset(exten, 0, sizeof(exten));
         len = 0;
      } else if (p->cancallforward && !strcmp(exten, "*73")) {
         if (option_verbose > 2) {
            ast_verbose(VERBOSE_PREFIX_3 "Cancelling call forwarding on channel %s\n", chan->name);
         }
         /*res = tone_zone_play_tone(p->subs[index].zfd, ZT_TONE_DIALRECALL);*/
         transmit_notify_request(sub, "L/sl");
         memset(p->call_forward, 0, sizeof(p->call_forward));
         getforward = 0;
         memset(exten, 0, sizeof(exten));
         len = 0;
      } else if (!strcmp(exten, ast_parking_ext()) && 
         sub->next->owner && ast_bridged_channel(sub->next->owner)) {
         /* This is a three way call, the main call being a real channel, 
            and we're parking the first call. */
         ast_masq_park_call(ast_bridged_channel(sub->next->owner), chan, 0, NULL);
         if (option_verbose > 2) {
            ast_verbose(VERBOSE_PREFIX_3 "Parking call to '%s'\n", chan->name);
         }
         break;
      } else if (!ast_strlen_zero(p->lastcallerid) && !strcmp(exten, "*60")) {
         if (option_verbose > 2) {
            ast_verbose(VERBOSE_PREFIX_3 "Blacklisting number %s\n", p->lastcallerid);
         }
         res = ast_db_put("blacklist", p->lastcallerid, "1");
         if (!res) {
            /*res = tone_zone_play_tone(p->subs[index].zfd, ZT_TONE_DIALRECALL);*/
            transmit_notify_request(sub, "L/sl");
            memset(exten, 0, sizeof(exten));
            len = 0;
         }
      } else if (p->hidecallerid && !strcmp(exten, "*82")) {
         if (option_verbose > 2) {
            ast_verbose(VERBOSE_PREFIX_3 "Enabling Caller*ID on %s\n", chan->name);
         }
         /* Enable Caller*ID if enabled */
         p->hidecallerid = 0;
         ast_set_callerid(chan, p->cid_num, p->cid_name, NULL);
         /*res = tone_zone_play_tone(p->subs[index].zfd, ZT_TONE_DIALRECALL);*/
         transmit_notify_request(sub, "L/sl");
         len = 0;
         memset(exten, 0, sizeof(exten));
         timeout = firstdigittimeout;
      } else if (!ast_canmatch_extension(chan, chan->context, exten, 1, chan->cid.cid_num) &&
            ((exten[0] != '*') || (strlen(exten) > 2))) {
         if (option_debug)
            ast_log(LOG_DEBUG, "Can't match %s from '%s' in context %s\n", exten, chan->cid.cid_num ? chan->cid.cid_num : "<Unknown Caller>", chan->context);
         break;
      }
      if (!timeout)
         timeout = gendigittimeout;
      if (len && !ast_ignore_pattern(chan->context, exten))
         /*tone_zone_play_tone(p->subs[index].zfd, -1);*/
         ast_indicate(chan, -1);
   }
#if 0
   for (;;) {
      res = ast_waitfordigit(chan, to);
      if (!res) {
         if (option_debug)
            ast_log(LOG_DEBUG, "Timeout...\n");
         break;
      }
      if (res < 0) {
         if (option_debug)
            ast_log(LOG_DEBUG, "Got hangup...\n");
         ast_hangup(chan);
         break;
      }
      exten[pos++] = res;
      if (!ast_ignore_pattern(chan->context, exten))
         ast_indicate(chan, -1);
      if (ast_matchmore_extension(chan, chan->context, exten, 1, chan->callerid)) {
         if (ast_exists_extension(chan, chan->context, exten, 1, chan->callerid)) 
            to = 3000;
         else
            to = 8000;
      } else
         break;
   }
   if (ast_exists_extension(chan, chan->context, exten, 1, chan->callerid)) {
      ast_copy_string(chan->exten, exten, sizeof(chan->exten)1);
      if (!p->rtp) {
         start_rtp(p);
      }
      ast_setstate(chan, AST_STATE_RING);
      chan->rings = 1;
      if (ast_pbx_run(chan)) {
         ast_log(LOG_WARNING, "Unable to launch PBX on %s\n", chan->name);
      } else
         return NULL;
   }
#endif
   ast_hangup(chan);
   return NULL;
}

static int attempt_transfer(struct mgcp_endpoint *p)
{
   /* *************************
    * I hope this works.
    * Copied out of chan_zap
    * Cross your fingers
    * *************************/

   /* In order to transfer, we need at least one of the channels to
      actually be in a call bridge.  We can't conference two applications
      together (but then, why would we want to?) */
   if (ast_bridged_channel(p->sub->owner)) {
      /* The three-way person we're about to transfer to could still be in MOH, so
         stop if now if appropriate */
      if (ast_bridged_channel(p->sub->next->owner))
         ast_queue_control(p->sub->next->owner, AST_CONTROL_UNHOLD);
      if (p->sub->owner->_state == AST_STATE_RINGING) {
         ast_indicate(ast_bridged_channel(p->sub->next->owner), AST_CONTROL_RINGING);
      }
      if (ast_channel_masquerade(p->sub->next->owner, ast_bridged_channel(p->sub->owner))) {
         ast_log(LOG_WARNING, "Unable to masquerade %s as %s\n",
            ast_bridged_channel(p->sub->owner)->name, p->sub->next->owner->name);
         return -1;
      }
      /* Orphan the channel */
      unalloc_sub(p->sub->next);
   } else if (ast_bridged_channel(p->sub->next->owner)) {
      if (p->sub->owner->_state == AST_STATE_RINGING) {
         ast_indicate(ast_bridged_channel(p->sub->next->owner), AST_CONTROL_RINGING);
      }
      ast_queue_control(p->sub->next->owner, AST_CONTROL_UNHOLD);
      if (ast_channel_masquerade(p->sub->owner, ast_bridged_channel(p->sub->next->owner))) {
         ast_log(LOG_WARNING, "Unable to masquerade %s as %s\n",
            ast_bridged_channel(p->sub->next->owner)->name, p->sub->owner->name);
         return -1;
      }
      /*swap_subs(p, SUB_THREEWAY, SUB_REAL);*/
      if (option_verbose > 2) {
         ast_verbose(VERBOSE_PREFIX_3 "Swapping %d for %d on %s@%s\n", p->sub->id, p->sub->next->id, p->name, p->parent->name);
      }
      p->sub = p->sub->next;
      unalloc_sub(p->sub->next);
      /* Tell the caller not to hangup */
      return 1;
   } else {
      if (option_debug)
         ast_log(LOG_DEBUG, "Neither %s nor %s are in a bridge, nothing to transfer\n",
            p->sub->owner->name, p->sub->next->owner->name);
      p->sub->next->owner->_softhangup |= AST_SOFTHANGUP_DEV;
      if (p->sub->next->owner) {
         p->sub->next->alreadygone = 1;
         mgcp_queue_hangup(p->sub->next);
      }
   }
   return 0;
}

static void handle_hd_hf(struct mgcp_subchannel *sub, char *ev) 
{
   struct mgcp_endpoint *p = sub->parent;
   struct ast_channel *c;
   pthread_t t;
   pthread_attr_t attr;
   pthread_attr_init(&attr);
   pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);   

   /* Off hook / answer */
   if (sub->outgoing) {
      /* Answered */
      if (sub->owner) {
         if (ast_bridged_channel(sub->owner))
            ast_queue_control(sub->owner, AST_CONTROL_UNHOLD);
         sub->cxmode = MGCP_CX_SENDRECV;
         if (!sub->rtp) {
            start_rtp(sub);
         } else {
            transmit_modify_request(sub);
         }
         /*transmit_notify_request(sub, "aw");*/
         transmit_notify_request(sub, "");
         mgcp_queue_control(sub, AST_CONTROL_ANSWER);
      }
   } else {
      /* Start switch */
      /*sub->cxmode = MGCP_CX_SENDRECV;*/
      if (!sub->owner) {
         if (!sub->rtp) {
            start_rtp(sub);
         } else {
            transmit_modify_request(sub);
         }
         if (p->immediate) {
            /* The channel is immediately up. Start right away */
#ifdef DLINK_BUGGY_FIRMWARE   
            transmit_notify_request(sub, "rt");
#else
            transmit_notify_request(sub, "G/rt");
#endif      
            c = mgcp_new(sub, AST_STATE_RING);
            if (!c) {
               ast_log(LOG_WARNING, "Unable to start PBX on channel %s@%s\n", p->name, p->parent->name);
               transmit_notify_request(sub, "G/cg");
               ast_hangup(c);
            }
         } else {
            if (has_voicemail(p)) {
               transmit_notify_request(sub, "L/sl");
            } else {
               transmit_notify_request(sub, "L/dl");
            }
            c = mgcp_new(sub, AST_STATE_DOWN);
            if (c) {
               if (ast_pthread_create(&t, &attr, mgcp_ss, c)) {
                  ast_log(LOG_WARNING, "Unable to create switch thread: %s\n", strerror(errno));
                  ast_hangup(c);
               }
            } else {
               ast_log(LOG_WARNING, "Unable to create channel for %s@%s\n", p->name, p->parent->name);
            }
         }
      } else {
         if (p->hookstate == MGCP_OFFHOOK) {
            ast_log(LOG_WARNING, "Off hook, but already have owner on %s@%s\n", p->name, p->parent->name);
         } else {
            ast_log(LOG_WARNING, "On hook, but already have owner on %s@%s\n", p->name, p->parent->name);
            ast_log(LOG_WARNING, "If we're onhook why are we here trying to handle a hd or hf?\n");
         }
         if (ast_bridged_channel(sub->owner))
            ast_queue_control(sub->owner, AST_CONTROL_UNHOLD);
         sub->cxmode = MGCP_CX_SENDRECV;
         if (!sub->rtp) {
            start_rtp(sub);
         } else {
            transmit_modify_request(sub);
         }
         /*transmit_notify_request(sub, "aw");*/
         transmit_notify_request(sub, "");
         /*ast_queue_control(sub->owner, AST_CONTROL_ANSWER);*/
      }
   }
}

static int handle_request(struct mgcp_subchannel *sub, struct mgcp_request *req, struct sockaddr_in *sin)
{
   char *ev, *s;
   struct ast_frame f = { 0, };
   struct mgcp_endpoint *p = sub->parent;
   struct mgcp_gateway *g = NULL;
   int res;

   if (mgcpdebug) {
      ast_verbose("Handling request '%s' on %s@%s\n", req->verb, p->name, p->parent->name);
   }
   /* Clear out potential response */
   if (!strcasecmp(req->verb, "RSIP")) {
      /* Test if this RSIP request is just a keepalive */
      if(!strcasecmp( get_header(req, "RM"), "X-keepalive")) {
         if (option_verbose > 2)
            ast_verbose(VERBOSE_PREFIX_3 "Received keepalive request from %s@%s\n", p->name, p->parent->name);
         transmit_response(sub, "200", req, "OK");
      } else {
         dump_queue(p->parent, p);
         dump_cmd_queues(p, NULL);
         
         if (option_verbose > 2 && (strcmp(p->name, p->parent->wcardep) != 0)) {
            ast_verbose(VERBOSE_PREFIX_3 "Resetting interface %s@%s\n", p->name, p->parent->name);
         }
         /* For RSIP on wildcard we reset all endpoints */
         if (!strcmp(p->name, p->parent->wcardep)) {
            /* Reset all endpoints */
            struct mgcp_endpoint *tmp_ep;
            
            g = p->parent;
            tmp_ep = g->endpoints;
            while (tmp_ep) {
               /*if ((strcmp(tmp_ep->name, "*") != 0) && (strcmp(tmp_ep->name, "aaln/" "*") != 0)) {*/
               if (strcmp(tmp_ep->name, g->wcardep) != 0) {
                  struct mgcp_subchannel *tmp_sub, *first_sub;
                  if (option_verbose > 2) {
                     ast_verbose(VERBOSE_PREFIX_3 "Resetting interface %s@%s\n", tmp_ep->name, p->parent->name);
                  }
                  
                  first_sub = tmp_ep->sub;
                  tmp_sub = tmp_ep->sub;
                  while (tmp_sub) {
                     mgcp_queue_hangup(tmp_sub);
                     tmp_sub = tmp_sub->next;
                     if (tmp_sub == first_sub)
                        break;
                  }
               }
               tmp_ep = tmp_ep->next;
            }
         } else if (sub->owner) {
            mgcp_queue_hangup(sub);
         }
         transmit_response(sub, "200", req, "OK");
         /* We dont send NTFY or AUEP to wildcard ep */
         if (strcmp(p->name, p->parent->wcardep) != 0) {
            transmit_notify_request(sub, "");
            /* Audit endpoint. 
             Idea is to prevent lost lines due to race conditions 
            */
            transmit_audit_endpoint(p);
         }
      }
   } else if (!strcasecmp(req->verb, "NTFY")) {
      /* Acknowledge and be sure we keep looking for the same things */
      transmit_response(sub, "200", req, "OK");
      /* Notified of an event */
      ev = get_header(req, "O");
      s = strchr(ev, '/');
      if (s) ev = s + 1;
      if (option_debug)
         ast_log(LOG_DEBUG, "Endpoint '%s@%s-%d' observed '%s'\n", p->name, p->parent->name, sub->id, ev);
      /* Keep looking for events unless this was a hangup */
      if (strcasecmp(ev, "hu") && strcasecmp(ev, "hd") && strcasecmp(ev, "ping")) {
         transmit_notify_request(sub, p->curtone);
      }
      if (!strcasecmp(ev, "hd")) {
         p->hookstate = MGCP_OFFHOOK;
         sub->cxmode = MGCP_CX_SENDRECV;
         handle_hd_hf(sub, ev);
      } else if (!strcasecmp(ev, "hf")) {
         /* We can assume we are offhook if we received a hookflash */
         /* First let's just do call wait and ignore threeway */
         /* We're currently in charge */
         if (p->hookstate != MGCP_OFFHOOK) {
            /* Cisco c7940 sends hf even if the phone is onhook */
            /* Thanks to point on IRC for pointing this out */
            return -1;
         }
         /* do not let * conference two down channels */  
         if (sub->owner && sub->owner->_state == AST_STATE_DOWN && !sub->next->owner)
            return -1;

         if (p->callwaiting || p->transfer || p->threewaycalling) {
            if (option_verbose > 2) {
               ast_verbose(VERBOSE_PREFIX_3 "Swapping %d for %d on %s@%s\n", p->sub->id, p->sub->next->id, p->name, p->parent->name);
            }
            p->sub = p->sub->next;

            /* transfer control to our next subchannel */
            if (!sub->next->owner) {
               /* plave the first call on hold and start up a new call */
               sub->cxmode = MGCP_CX_MUTE;
               if (option_verbose > 2) {
                  ast_verbose(VERBOSE_PREFIX_3 "MGCP Muting %d on %s@%s\n", sub->id, p->name, p->parent->name);
               }
               transmit_modify_request(sub);
               if (sub->owner && ast_bridged_channel(sub->owner))
                  ast_queue_control(sub->owner, AST_CONTROL_HOLD);
               sub->next->cxmode = MGCP_CX_RECVONLY;
               handle_hd_hf(sub->next, ev);
            } else if (sub->owner && sub->next->owner) {
               /* We've got two active calls lets decide whether or not to conference or just flip flop */
               if ((!sub->outgoing) && (!sub->next->outgoing)) {
                  /* We made both calls lets conferenct */
                  if (option_verbose > 2) {
                     ast_verbose(VERBOSE_PREFIX_3 "MGCP Conferencing %d and %d on %s@%s\n", 
                        sub->id, sub->next->id, p->name, p->parent->name);
                  }
                  sub->cxmode = MGCP_CX_CONF;
                  sub->next->cxmode = MGCP_CX_CONF;
                  if (ast_bridged_channel(sub->next->owner))
                     ast_queue_control(sub->next->owner, AST_CONTROL_UNHOLD);
                  transmit_modify_request(sub);
                  transmit_modify_request(sub->next);
               } else {
                  /* Let's flipflop between calls */
                  /* XXX Need to check for state up ??? */
                  /* XXX Need a way to indicate the current call, or maybe the call that's waiting */
                  if (option_verbose > 2) {
                     ast_verbose(VERBOSE_PREFIX_3 "We didn't make one of the calls FLIPFLOP %d and %d on %s@%s\n", 
                        sub->id, sub->next->id, p->name, p->parent->name);
                  }
                  sub->cxmode = MGCP_CX_MUTE;
                  if (option_verbose > 2) {
                     ast_verbose(VERBOSE_PREFIX_3 "MGCP Muting %d on %s@%s\n", sub->id, p->name, p->parent->name);
                  }
                  transmit_modify_request(sub);
                  if (ast_bridged_channel(sub->owner))
                     ast_queue_control(sub->owner, AST_CONTROL_HOLD);
                        
                  if (ast_bridged_channel(sub->next->owner)) 
                     ast_queue_control(sub->next->owner, AST_CONTROL_HOLD);
                        
                  handle_hd_hf(sub->next, ev);
               }
            } else {
               /* We've most likely lost one of our calls find an active call and bring it up */
               if (sub->owner) {
                  p->sub = sub;
               } else if (sub->next->owner) {
                  p->sub = sub->next;
               } else {
                  /* We seem to have lost both our calls */
                  /* XXX - What do we do now? */
                  return -1;
               }
               if (ast_bridged_channel(p->sub->owner))
                  ast_queue_control(p->sub->owner, AST_CONTROL_UNHOLD);
               p->sub->cxmode = MGCP_CX_SENDRECV;
               transmit_modify_request(p->sub);
            }
         } else {