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Last updated: Sat Feb 3 05:00:34 2007

Asterisk developer's documentation :: Codename Pineapple

---

chan_iax2.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 Inter-Asterisk eXchange Version 2
 *
 * \author Mark Spencer <markster@digium.com>
 *
 * \par See also
 * \arg \ref Config_iax
 *
 * \ingroup channel_drivers
 */

/*** MODULEINFO
   <use>zaptel</use>
 ***/

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision: 53128 $")

#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/mman.h>
#include <dirent.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <sys/time.h>
#include <sys/signal.h>
#include <signal.h>
#include <string.h>
#include <strings.h>
#include <errno.h>
#include <unistd.h>
#include <netdb.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <regex.h>

#include "asterisk/zapata.h"

#include "asterisk/lock.h"
#include "asterisk/frame.h" 
#include "asterisk/channel.h"
#include "asterisk/logger.h"
#include "asterisk/module.h"
#include "asterisk/pbx.h"
#include "asterisk/sched.h"
#include "asterisk/io.h"
#include "asterisk/config.h"
#include "asterisk/options.h"
#include "asterisk/cli.h"
#include "asterisk/translate.h"
#include "asterisk/md5.h"
#include "asterisk/cdr.h"
#include "asterisk/crypto.h"
#include "asterisk/acl.h"
#include "asterisk/manager.h"
#include "asterisk/callerid.h"
#include "asterisk/app.h"
#include "asterisk/astdb.h"
#include "asterisk/musiconhold.h"
#include "asterisk/features.h"
#include "asterisk/utils.h"
#include "asterisk/causes.h"
#include "asterisk/localtime.h"
#include "asterisk/aes.h"
#include "asterisk/dnsmgr.h"
#include "asterisk/devicestate.h"
#include "asterisk/netsock.h"
#include "asterisk/stringfields.h"
#include "asterisk/linkedlists.h"

#include "iax2.h"
#include "iax2-parser.h"
#include "iax2-provision.h"
#include "jitterbuf.h"

/* Define SCHED_MULTITHREADED to run the scheduler in a special
   multithreaded mode. */
#define SCHED_MULTITHREADED

/* Define DEBUG_SCHED_MULTITHREADED to keep track of where each
   thread is actually doing. */
#define DEBUG_SCHED_MULTITHREAD

#ifndef IPTOS_MINCOST
#define IPTOS_MINCOST 0x02
#endif

#ifdef SO_NO_CHECK
static int nochecksums = 0;
#endif


#define PTR_TO_CALLNO(a) ((unsigned short)(unsigned long)(a))
#define CALLNO_TO_PTR(a) ((void *)(unsigned long)(a))

#define DEFAULT_THREAD_COUNT 10
#define DEFAULT_MAX_THREAD_COUNT 100
#define DEFAULT_RETRY_TIME 1000
#define MEMORY_SIZE 100
#define DEFAULT_DROP 3
/* Flag to use with trunk calls, keeping these calls high up.  It halves our effective use
   but keeps the division between trunked and non-trunked better. */
#define TRUNK_CALL_START   0x4000

#define DEBUG_SUPPORT

#define MIN_REUSE_TIME     60 /* Don't reuse a call number within 60 seconds */

/* Sample over last 100 units to determine historic jitter */
#define GAMMA (0.01)

static struct ast_codec_pref prefs;

static const char tdesc[] = "Inter Asterisk eXchange Driver (Ver 2)";


/*! \brief Maximum transmission unit for the UDP packet in the trunk not to be
    fragmented. This is based on 1516 - ethernet - ip - udp - iax minus one g711 frame = 1240 */
#define MAX_TRUNK_MTU 1240 

static int global_max_trunk_mtu;    /*!< Maximum MTU, 0 if not used */
static int trunk_timed, trunk_untimed, trunk_maxmtu, trunk_nmaxmtu ;    /*!< Trunk MTU statistics */


static char context[80] = "default";

static char language[MAX_LANGUAGE] = "";
static char regcontext[AST_MAX_CONTEXT] = "";

static int maxauthreq = 3;
static int max_retries = 4;
static int ping_time = 20;
static int lagrq_time = 10;
static int maxtrunkcall = TRUNK_CALL_START;
static int maxnontrunkcall = 1;
static int maxjitterbuffer=1000;
static int resyncthreshold=1000;
static int maxjitterinterps=10;
static int jittertargetextra = 40; /* number of milliseconds the new jitter buffer adds on to its size */

#define MAX_TRUNKDATA           640 * 200       /*!< 40ms, uncompressed linear * 200 channels */

static int trunkfreq = 20;
static int trunkmaxsize = MAX_TRUNKDATA;

static int authdebug = 1;
static int autokill = 0;
static int iaxcompat = 0;

static int iaxdefaultdpcache=10 * 60;  /* Cache dialplan entries for 10 minutes by default */

static int iaxdefaulttimeout = 5;      /* Default to wait no more than 5 seconds for a reply to come back */

static unsigned int tos = 0;

static int min_reg_expire;
static int max_reg_expire;

static int srvlookup = 0;

static int timingfd = -1;           /* Timing file descriptor */

static struct ast_netsock_list *netsock;
static int defaultsockfd = -1;

int (*iax2_regfunk)(const char *username, int onoff) = NULL;

/* Ethernet, etc */
#define IAX_CAPABILITY_FULLBANDWIDTH   0xFFFF
/* T1, maybe ISDN */
#define IAX_CAPABILITY_MEDBANDWIDTH    (IAX_CAPABILITY_FULLBANDWIDTH &  \
                ~AST_FORMAT_SLINEAR &        \
                ~AST_FORMAT_ULAW &        \
                ~AST_FORMAT_ALAW &        \
                ~AST_FORMAT_G722) 
/* A modem */
#define IAX_CAPABILITY_LOWBANDWIDTH (IAX_CAPABILITY_MEDBANDWIDTH &      \
                ~AST_FORMAT_G726 &        \
                ~AST_FORMAT_G726_AAL2 &      \
                ~AST_FORMAT_ADPCM)

#define IAX_CAPABILITY_LOWFREE      (IAX_CAPABILITY_LOWBANDWIDTH &      \
                ~AST_FORMAT_G723_1)


#define DEFAULT_MAXMS      2000     /* Must be faster than 2 seconds by default */
#define DEFAULT_FREQ_OK    60 * 1000   /* How often to check for the host to be up */
#define DEFAULT_FREQ_NOTOK 10 * 1000   /* How often to check, if the host is down... */

static   struct io_context *io;
static   struct sched_context *sched;

static int iax2_capability = IAX_CAPABILITY_FULLBANDWIDTH;

static int iaxdebug = 0;

static int iaxtrunkdebug = 0;

static int test_losspct = 0;
#ifdef IAXTESTS
static int test_late = 0;
static int test_resync = 0;
static int test_jit = 0;
static int test_jitpct = 0;
#endif /* IAXTESTS */

static char accountcode[AST_MAX_ACCOUNT_CODE];
static char mohinterpret[MAX_MUSICCLASS];
static char mohsuggest[MAX_MUSICCLASS];
static int amaflags = 0;
static int adsi = 0;
static int delayreject = 0;
static int iax2_encryption = 0;

static struct ast_flags globalflags = { 0 };

static pthread_t netthreadid = AST_PTHREADT_NULL;
static pthread_t schedthreadid = AST_PTHREADT_NULL;
AST_MUTEX_DEFINE_STATIC(sched_lock);
static ast_cond_t sched_cond;

enum iax2_state {
   IAX_STATE_STARTED =     (1 << 0),
   IAX_STATE_AUTHENTICATED =  (1 << 1),
   IAX_STATE_TBD =      (1 << 2),
   IAX_STATE_UNCHANGED =      (1 << 3),
};

struct iax2_context {
   char context[AST_MAX_CONTEXT];
   struct iax2_context *next;
};

enum iax2_flags {
   IAX_HASCALLERID =    (1 << 0),   /*!< CallerID has been specified */
   IAX_DELME =    (1 << 1),   /*!< Needs to be deleted */
   IAX_TEMPONLY =    (1 << 2),   /*!< Temporary (realtime) */
   IAX_TRUNK =    (1 << 3),   /*!< Treat as a trunk */
   IAX_NOTRANSFER =  (1 << 4),   /*!< Don't native bridge */
   IAX_USEJITTERBUF =   (1 << 5),   /*!< Use jitter buffer */
   IAX_DYNAMIC =     (1 << 6),   /*!< dynamic peer */
   IAX_SENDANI =     (1 << 7),   /*!< Send ANI along with CallerID */
        /* (1 << 8) is currently unused due to the deprecation of an old option. Go ahead, take it! */
   IAX_ALREADYGONE = (1 << 9),   /*!< Already disconnected */
   IAX_PROVISION =      (1 << 10),  /*!< This is a provisioning request */
   IAX_QUELCH =      (1 << 11),  /*!< Whether or not we quelch audio */
   IAX_ENCRYPTED =      (1 << 12),  /*!< Whether we should assume encrypted tx/rx */
   IAX_KEYPOPULATED =   (1 << 13),  /*!< Whether we have a key populated */
   IAX_CODEC_USER_FIRST =  (1 << 14),  /*!< are we willing to let the other guy choose the codec? */
   IAX_CODEC_NOPREFS =     (1 << 15),  /*!< Force old behaviour by turning off prefs */
   IAX_CODEC_NOCAP =    (1 << 16),  /*!< only consider requested format and ignore capabilities*/
   IAX_RTCACHEFRIENDS =    (1 << 17),  /*!< let realtime stay till your reload */
   IAX_RTUPDATE =       (1 << 18),  /*!< Send a realtime update */
   IAX_RTAUTOCLEAR =    (1 << 19),  /*!< erase me on expire */ 
   IAX_FORCEJITTERBUF = (1 << 20),  /*!< Force jitterbuffer, even when bridged to a channel that can take jitter */ 
   IAX_RTIGNOREREGEXPIRE = (1 << 21),  /*!< When using realtime, ignore registration expiration */
   IAX_TRUNKTIMESTAMPS =   (1 << 22),  /*!< Send trunk timestamps */
   IAX_TRANSFERMEDIA =  (1 << 23),      /*!< When doing IAX2 transfers, transfer media only */
   IAX_MAXAUTHREQ =        (1 << 24),      /*!< Maximum outstanding AUTHREQ restriction is in place */
};

static int global_rtautoclear = 120;

static int reload_config(void);
static int iax2_reload(int fd, int argc, char *argv[]);


struct iax2_user {
   AST_DECLARE_STRING_FIELDS(
      AST_STRING_FIELD(name);
      AST_STRING_FIELD(secret);
      AST_STRING_FIELD(dbsecret);
      AST_STRING_FIELD(accountcode);
      AST_STRING_FIELD(mohinterpret);
      AST_STRING_FIELD(mohsuggest);
      AST_STRING_FIELD(inkeys);               /*!< Key(s) this user can use to authenticate to us */
      AST_STRING_FIELD(language);
      AST_STRING_FIELD(cid_num);
      AST_STRING_FIELD(cid_name);
   );
   
   int authmethods;
   int encmethods;
   int amaflags;
   int adsi;
   unsigned int flags;
   int capability;
   int maxauthreq; /*!< Maximum allowed outstanding AUTHREQs */
   int curauthreq; /*!< Current number of outstanding AUTHREQs */
   struct ast_codec_pref prefs;
   struct ast_ha *ha;
   struct iax2_context *contexts;
   struct ast_variable *vars;
   AST_LIST_ENTRY(iax2_user) entry;
};

struct iax2_peer {
   AST_DECLARE_STRING_FIELDS(
      AST_STRING_FIELD(name);
      AST_STRING_FIELD(username);
      AST_STRING_FIELD(secret);
      AST_STRING_FIELD(dbsecret);
      AST_STRING_FIELD(outkey);      /*!< What key we use to talk to this peer */

      AST_STRING_FIELD(regexten);     /*!< Extension to register (if regcontext is used) */
      AST_STRING_FIELD(context);      /*!< For transfers only */
      AST_STRING_FIELD(peercontext);  /*!< Context to pass to peer */
      AST_STRING_FIELD(mailbox);     /*!< Mailbox */
      AST_STRING_FIELD(mohinterpret);
      AST_STRING_FIELD(mohsuggest);
      AST_STRING_FIELD(inkeys);     /*!< Key(s) this peer can use to authenticate to us */
      /* Suggested caller id if registering */
      AST_STRING_FIELD(cid_num);    /*!< Default context (for transfer really) */
      AST_STRING_FIELD(cid_name);      /*!< Default context (for transfer really) */
      AST_STRING_FIELD(zonetag);    /*!< Time Zone */
   );
   struct ast_codec_pref prefs;
   struct ast_dnsmgr_entry *dnsmgr;    /*!< DNS refresh manager */
   struct sockaddr_in addr;
   int formats;
   int sockfd;             /*!< Socket to use for transmission */
   struct in_addr mask;
   int adsi;
   unsigned int flags;

   /* Dynamic Registration fields */
   struct sockaddr_in defaddr;         /*!< Default address if there is one */
   int authmethods;           /*!< Authentication methods (IAX_AUTH_*) */
   int encmethods;               /*!< Encryption methods (IAX_ENCRYPT_*) */

   int expire;             /*!< Schedule entry for expiry */
   int expiry;             /*!< How soon to expire */
   int capability;               /*!< Capability */

   /* Qualification */
   int callno;             /*!< Call number of POKE request */
   int pokeexpire;               /*!< Scheduled qualification-related task (ie iax2_poke_peer_s or iax2_poke_noanswer) */
   int lastms;             /*!< How long last response took (in ms), or -1 for no response */
   int maxms;              /*!< Max ms we will accept for the host to be up, 0 to not monitor */

   int pokefreqok;               /*!< How often to check if the host is up */
   int pokefreqnotok;            /*!< How often to check when the host has been determined to be down */
   int historicms;               /*!< How long recent average responses took */
   int smoothing;             /*!< Sample over how many units to determine historic ms */
   
   struct ast_ha *ha;
   AST_LIST_ENTRY(iax2_peer) entry;
};

#define IAX2_TRUNK_PREFACE (sizeof(struct iax_frame) + sizeof(struct ast_iax2_meta_hdr) + sizeof(struct ast_iax2_meta_trunk_hdr))

struct iax2_trunk_peer {
   ast_mutex_t lock;
   int sockfd;
   struct sockaddr_in addr;
   struct timeval txtrunktime;      /*!< Transmit trunktime */
   struct timeval rxtrunktime;      /*!< Receive trunktime */
   struct timeval lasttxtime;    /*!< Last transmitted trunktime */
   struct timeval trunkact;      /*!< Last trunk activity */
   unsigned int lastsent;        /*!< Last sent time */
   /* Trunk data and length */
   unsigned char *trunkdata;
   unsigned int trunkdatalen;
   unsigned int trunkdataalloc;
   int trunkmaxmtu;
   int trunkerror;
   int calls;
   AST_LIST_ENTRY(iax2_trunk_peer) list;
};

static AST_LIST_HEAD_STATIC(tpeers, iax2_trunk_peer);

struct iax_firmware {
   AST_LIST_ENTRY(iax_firmware) list;
   int fd;
   int mmaplen;
   int dead;
   struct ast_iax2_firmware_header *fwh;
   unsigned char *buf;
};

enum iax_reg_state {
   REG_STATE_UNREGISTERED = 0,
   REG_STATE_REGSENT,
   REG_STATE_AUTHSENT,
   REG_STATE_REGISTERED,
   REG_STATE_REJECTED,
   REG_STATE_TIMEOUT,
   REG_STATE_NOAUTH
};

enum iax_transfer_state {
   TRANSFER_NONE = 0,
   TRANSFER_BEGIN,
   TRANSFER_READY,
   TRANSFER_RELEASED,
   TRANSFER_PASSTHROUGH,
   TRANSFER_MBEGIN,
   TRANSFER_MREADY,
   TRANSFER_MRELEASED,
   TRANSFER_MPASSTHROUGH,
   TRANSFER_MEDIA,
   TRANSFER_MEDIAPASS
};

struct iax2_registry {
   struct sockaddr_in addr;      /*!< Who we connect to for registration purposes */
   char username[80];
   char secret[80];        /*!< Password or key name in []'s */
   char random[80];
   int expire;          /*!< Sched ID of expiration */
   int refresh;            /*!< How often to refresh */
   enum iax_reg_state regstate;
   int messages;           /*!< Message count, low 8 bits = new, high 8 bits = old */
   int callno;          /*!< Associated call number if applicable */
   struct sockaddr_in us;        /*!< Who the server thinks we are */
   struct ast_dnsmgr_entry *dnsmgr; /*!< DNS refresh manager */
   AST_LIST_ENTRY(iax2_registry) entry;
};

static AST_LIST_HEAD_STATIC(registrations, iax2_registry);

/* Don't retry more frequently than every 10 ms, or less frequently than every 5 seconds */
#define MIN_RETRY_TIME     100
#define MAX_RETRY_TIME     10000

#define MAX_JITTER_BUFFER  50
#define MIN_JITTER_BUFFER  10

#define DEFAULT_TRUNKDATA  640 * 10 /*!< 40ms, uncompressed linear * 10 channels */

#define MAX_TIMESTAMP_SKEW 160      /*!< maximum difference between actual and predicted ts for sending */

/* If consecutive voice frame timestamps jump by more than this many milliseconds, then jitter buffer will resync */
#define TS_GAP_FOR_JB_RESYNC  5000

static int iaxthreadcount = DEFAULT_THREAD_COUNT;
static int iaxmaxthreadcount = DEFAULT_MAX_THREAD_COUNT;
static int iaxdynamicthreadcount = 0;

struct iax_rr {
   int jitter;
   int losspct;
   int losscnt;
   int packets;
   int delay;
   int dropped;
   int ooo;
};

struct chan_iax2_pvt {
   /*! Socket to send/receive on for this call */
   int sockfd;
   /*! Last received voice format */
   int voiceformat;
   /*! Last received video format */
   int videoformat;
   /*! Last sent voice format */
   int svoiceformat;
   /*! Last sent video format */
   int svideoformat;
   /*! What we are capable of sending */
   int capability;
   /*! Last received timestamp */
   unsigned int last;
   /*! Last sent timestamp - never send the same timestamp twice in a single call */
   unsigned int lastsent;
   /*! Next outgoing timestamp if everything is good */
   unsigned int nextpred;
   /*! True if the last voice we transmitted was not silence/CNG */
   unsigned int notsilenttx:1;
   /*! Ping time */
   unsigned int pingtime;
   /*! Max time for initial response */
   int maxtime;
   /*! Peer Address */
   struct sockaddr_in addr;
   /*! Actual used codec preferences */
   struct ast_codec_pref prefs;
   /*! Requested codec preferences */
   struct ast_codec_pref rprefs;
   /*! Our call number */
   unsigned short callno;
   /*! Peer callno */
   unsigned short peercallno;
   /*! Peer selected format */
   int peerformat;
   /*! Peer capability */
   int peercapability;
   /*! timeval that we base our transmission on */
   struct timeval offset;
   /*! timeval that we base our delivery on */
   struct timeval rxcore;
   /*! The jitterbuffer */
   jitterbuf *jb;
   /*! active jb read scheduler id */
   int jbid;                       
   /*! LAG */
   int lag;
   /*! Error, as discovered by the manager */
   int error;
   /*! Owner if we have one */
   struct ast_channel *owner;
   /*! What's our state? */
   struct ast_flags state;
   /*! Expiry (optional) */
   int expiry;
   /*! Next outgoing sequence number */
   unsigned char oseqno;
   /*! Next sequence number they have not yet acknowledged */
   unsigned char rseqno;
   /*! Next incoming sequence number */
   unsigned char iseqno;
   /*! Last incoming sequence number we have acknowledged */
   unsigned char aseqno;

   AST_DECLARE_STRING_FIELDS(
      /*! Peer name */
      AST_STRING_FIELD(peer);
      /*! Default Context */
      AST_STRING_FIELD(context);
      /*! Caller ID if available */
      AST_STRING_FIELD(cid_num);
      AST_STRING_FIELD(cid_name);
      /*! Hidden Caller ID (i.e. ANI) if appropriate */
      AST_STRING_FIELD(ani);
      /*! DNID */
      AST_STRING_FIELD(dnid);
      /*! RDNIS */
      AST_STRING_FIELD(rdnis);
      /*! Requested Extension */
      AST_STRING_FIELD(exten);
      /*! Expected Username */
      AST_STRING_FIELD(username);
      /*! Expected Secret */
      AST_STRING_FIELD(secret);
      /*! MD5 challenge */
      AST_STRING_FIELD(challenge);
      /*! Public keys permitted keys for incoming authentication */
      AST_STRING_FIELD(inkeys);
      /*! Private key for outgoing authentication */
      AST_STRING_FIELD(outkey);
      /*! Preferred language */
      AST_STRING_FIELD(language);
      /*! Hostname/peername for naming purposes */
      AST_STRING_FIELD(host);

      AST_STRING_FIELD(dproot);
      AST_STRING_FIELD(accountcode);
      AST_STRING_FIELD(mohinterpret);
      AST_STRING_FIELD(mohsuggest);
   );
   
   /*! permitted authentication methods */
   int authmethods;
   /*! permitted encryption methods */
   int encmethods;
   /*! Encryption AES-128 Key */
   aes_encrypt_ctx ecx;
   /*! Decryption AES-128 Key */
   aes_decrypt_ctx dcx;
   /*! 32 bytes of semi-random data */
   unsigned char semirand[32];
   /*! Associated registry */
   struct iax2_registry *reg;
   /*! Associated peer for poking */
   struct iax2_peer *peerpoke;
   /*! IAX_ flags */
   unsigned int flags;
   int adsi;

   /*! Transferring status */
   enum iax_transfer_state transferring;
   /*! Transfer identifier */
   int transferid;
   /*! Who we are IAX transferring to */
   struct sockaddr_in transfer;
   /*! What's the new call number for the transfer */
   unsigned short transfercallno;
   /*! Transfer decrypt AES-128 Key */
   aes_encrypt_ctx tdcx;

   /*! Status of knowledge of peer ADSI capability */
   int peeradsicpe;

   /*! Who we are bridged to */
   unsigned short bridgecallno;
   
   int pingid;       /*!< Transmit PING request */
   int lagid;        /*!< Retransmit lag request */
   int autoid;       /*!< Auto hangup for Dialplan requestor */
   int authid;       /*!< Authentication rejection ID */
   int authfail;        /*!< Reason to report failure */
   int initid;       /*!< Initial peer auto-congest ID (based on qualified peers) */
   int calling_ton;
   int calling_tns;
   int calling_pres;
   int amaflags;
   AST_LIST_HEAD_NOLOCK(, iax2_dpcache) dpentries;
   struct ast_variable *vars;
   /*! last received remote rr */
   struct iax_rr remote_rr;
   /*! Current base time: (just for stats) */
   int min;
   /*! Dropped frame count: (just for stats) */
   int frames_dropped;
   /*! received frame count: (just for stats) */
   int frames_received;
};

static AST_LIST_HEAD_STATIC(queue, iax_frame);

static AST_LIST_HEAD_STATIC(users, iax2_user);

static AST_LIST_HEAD_STATIC(peers, iax2_peer);

static AST_LIST_HEAD_STATIC(firmwares, iax_firmware);

enum {
   /*! Extension exists */
   CACHE_FLAG_EXISTS      = (1 << 0),
   /*! Extension is nonexistent */
   CACHE_FLAG_NONEXISTENT = (1 << 1),
   /*! Extension can exist */
   CACHE_FLAG_CANEXIST    = (1 << 2),
   /*! Waiting to hear back response */
   CACHE_FLAG_PENDING     = (1 << 3),
   /*! Timed out */
   CACHE_FLAG_TIMEOUT     = (1 << 4),
   /*! Request transmitted */
   CACHE_FLAG_TRANSMITTED = (1 << 5),
   /*! Timeout */
   CACHE_FLAG_UNKNOWN     = (1 << 6),
   /*! Matchmore */
   CACHE_FLAG_MATCHMORE   = (1 << 7),
};

struct iax2_dpcache {
   char peercontext[AST_MAX_CONTEXT];
   char exten[AST_MAX_EXTENSION];
   struct timeval orig;
   struct timeval expiry;
   int flags;
   unsigned short callno;
   int waiters[256];
   AST_LIST_ENTRY(iax2_dpcache) cache_list;
   AST_LIST_ENTRY(iax2_dpcache) peer_list;
};

static AST_LIST_HEAD_STATIC(dpcache, iax2_dpcache);

static void reg_source_db(struct iax2_peer *p);
static struct iax2_peer *realtime_peer(const char *peername, struct sockaddr_in *sin);

static void destroy_peer(struct iax2_peer *peer);
static int ast_cli_netstats(struct mansession *s, int fd, int limit_fmt);

enum iax2_thread_iostate {
   IAX_IOSTATE_IDLE,
   IAX_IOSTATE_READY,
   IAX_IOSTATE_PROCESSING,
   IAX_IOSTATE_SCHEDREADY,
};

enum iax2_thread_type {
   IAX_THREAD_TYPE_POOL,
   IAX_THREAD_TYPE_DYNAMIC,
};

struct iax2_thread {
   AST_LIST_ENTRY(iax2_thread) list;
   enum iax2_thread_type type;
   enum iax2_thread_iostate iostate;
#ifdef SCHED_MULTITHREADED
   void (*schedfunc)(void *);
   void *scheddata;
#endif
#ifdef DEBUG_SCHED_MULTITHREAD
   char curfunc[80];
#endif   
   int actions;
   pthread_t threadid;
   int threadnum;
   struct sockaddr_in iosin;
   unsigned char buf[4096]; 
   int iores;
   int iofd;
   time_t checktime;
   ast_mutex_t lock;
   ast_cond_t cond;
};

/* Thread lists */
static AST_LIST_HEAD_STATIC(idle_list, iax2_thread);
static AST_LIST_HEAD_STATIC(active_list, iax2_thread);
static AST_LIST_HEAD_STATIC(dynamic_list, iax2_thread);

static void *iax2_process_thread(void *data);

static void signal_condition(ast_mutex_t *lock, ast_cond_t *cond)
{
   ast_mutex_lock(lock);
   ast_cond_signal(cond);
   ast_mutex_unlock(lock);
}

static void iax_debug_output(const char *data)
{
   if (iaxdebug)
      ast_verbose("%s", data);
}

static void iax_error_output(const char *data)
{
   ast_log(LOG_WARNING, "%s", data);
}

static void jb_error_output(const char *fmt, ...)
{
   va_list args;
   char buf[1024];

   va_start(args, fmt);
   vsnprintf(buf, sizeof(buf), fmt, args);
   va_end(args);

   ast_log(LOG_ERROR, buf);
}

static void jb_warning_output(const char *fmt, ...)
{
   va_list args;
   char buf[1024];

   va_start(args, fmt);
   vsnprintf(buf, sizeof(buf), fmt, args);
   va_end(args);

   ast_log(LOG_WARNING, buf);
}

static void jb_debug_output(const char *fmt, ...)
{
   va_list args;
   char buf[1024];

   va_start(args, fmt);
   vsnprintf(buf, sizeof(buf), fmt, args);
   va_end(args);

   ast_verbose(buf);
}

/*!
 * \brief an array of iax2 pvt structures
 *
 * The container for active chan_iax2_pvt structures is implemented as an
 * array for extremely quick direct access to the correct pvt structure
 * based on the local call number.  The local call number is used as the
 * index into the array where the associated pvt structure is stored.
 */
static struct chan_iax2_pvt *iaxs[IAX_MAX_CALLS];
/*!
 * \brief chan_iax2_pvt structure locks
 *
 * These locks are used when accessing a pvt structure in the iaxs array.
 * The index used here is the same as used in the iaxs array.  It is the
 * local call number for the associated pvt struct.
 */
static ast_mutex_t iaxsl[IAX_MAX_CALLS];
/*!
 * \brief The last time a call number was used
 *
 * It is important to know the last time that a call number was used locally so
 * that it is not used again too soon.  The reason for this is the same as the
 * reason that the TCP protocol state machine requires a "TIME WAIT" state.
 *
 * For example, say that a call is up.  Then, the remote side sends a HANGUP,
 * which we respond to with an ACK.  However, there is no way to know whether
 * the ACK made it there successfully.  If it were to get lost, the remote
 * side may retransmit the HANGUP.  If in the meantime, this call number has
 * been reused locally, given the right set of circumstances, this retransmitted
 * HANGUP could potentially improperly hang up the new session.  So, to avoid
 * this potential issue, we must wait a specified timeout period before reusing
 * a local call number.
 *
 * The specified time that we must wait before reusing a local call number is
 * defined as MIN_REUSE_TIME, with a default of 60 seconds.
 */
static struct timeval lastused[IAX_MAX_CALLS];

static enum ast_bridge_result iax2_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, struct ast_frame **fo, struct ast_channel **rc, int timeoutms);
static int expire_registry(void *data);
static int iax2_answer(struct ast_channel *c);
static int iax2_call(struct ast_channel *c, char *dest, int timeout);
static int iax2_devicestate(void *data);
static int iax2_digit_begin(struct ast_channel *c, char digit);
static int iax2_digit_end(struct ast_channel *c, char digit, unsigned int duration);
static int iax2_do_register(struct iax2_registry *reg);
static int iax2_fixup(struct ast_channel *oldchannel, struct ast_channel *newchan);
static int iax2_hangup(struct ast_channel *c);
static int iax2_indicate(struct ast_channel *c, int condition, const void *data, size_t datalen);
static int iax2_poke_peer(struct iax2_peer *peer, int heldcall);
static int iax2_provision(struct sockaddr_in *end, int sockfd, char *dest, const char *template, int force);
static int iax2_send(struct chan_iax2_pvt *pvt, struct ast_frame *f, unsigned int ts, int seqno, int now, int transfer, int final);
static int iax2_sendhtml(struct ast_channel *c, int subclass, const char *data, int datalen);
static int iax2_sendimage(struct ast_channel *c, struct ast_frame *img);
static int