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
 *        as specified in RFC 5456
 *
 * \author Mark Spencer <markster@digium.com>
 *
 * \ingroup channel_drivers
 *
 * \todo Implement musicclass settings for IAX2 devices
 */
 
/*! \li \ref chan_iax2.c uses the configuration file \ref iax.conf
 * \addtogroup configuration_file
 */
 
/*! \page iax.conf iax.conf
 * \verbinclude iax.conf.sample
 */
 
/*!
 * \todo XXX The IAX2 channel driver needs its native bridge
 * code converted to the new bridge technology scheme.
 *
 * \note The chan_dahdi native bridge code can be used as an
 * example.  It also appears that chan_iax2 also has a native
 * transfer check like chan_dahdi to eliminate tromboned calls.
 *
 * \note The existing native bridge code is marked with the
 * IAX2_NATIVE_BRIDGING conditional.
 */
 
/*** MODULEINFO
    <use type="module">res_crypto</use>
    <use type="external">crypto</use>
    <support_level>core</support_level>
 ***/
 
#include "asterisk.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 <signal.h>
#include <netdb.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <regex.h>
 
#include "asterisk/paths.h"
 
#include "asterisk/lock.h"
#include "asterisk/frame.h"
#include "asterisk/channel.h"
#include "asterisk/module.h"
#include "asterisk/pbx.h"
#include "asterisk/sched.h"
#include "asterisk/io.h"
#include "asterisk/config.h"
#include "asterisk/cli.h"
#include "asterisk/translate.h"
#include "asterisk/md5.h"
#include "asterisk/crypto.h"
#include "asterisk/acl.h"
#include "asterisk/manager.h"
#include "asterisk/callerid.h"
#include "asterisk/app.h"
#include "asterisk/mwi.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/dnsmgr.h"
#include "asterisk/devicestate.h"
#include "asterisk/stringfields.h"
#include "asterisk/linkedlists.h"
#include "asterisk/astobj2.h"
#include "asterisk/timing.h"
#include "asterisk/taskprocessor.h"
#include "asterisk/test.h"
#include "asterisk/security_events.h"
#include "asterisk/stasis_endpoints.h"
#include "asterisk/bridge.h"
#include "asterisk/stasis.h"
#include "asterisk/stasis_system.h"
#include "asterisk/stasis_channels.h"
#include "asterisk/format_cache.h"
#include "asterisk/format_compatibility.h"
#include "asterisk/format_cap.h"
 
#include "iax2/include/iax2.h"
#include "iax2/include/firmware.h"
#include "iax2/include/parser.h"
#include "iax2/include/provision.h"
#include "iax2/include/codec_pref.h"
#include "iax2/include/format_compatibility.h"
#include "iax2/include/netsock.h"
 
#include "jitterbuf.h"
 
/*** DOCUMENTATION
    <application name="IAX2Provision" language="en_US">
        <synopsis>
            Provision a calling IAXy with a given template.
        </synopsis>
        <syntax>
            <parameter name="template">
                <para>If not specified, defaults to <literal>default</literal>.</para>
            </parameter>
        </syntax>
        <description>
            <para>Provisions the calling IAXy (assuming the calling entity is in fact an IAXy) with the
            given <replaceable>template</replaceable>. Returns <literal>-1</literal> on error
            or <literal>0</literal> on success.</para>
        </description>
    </application>
    <function name="IAXPEER" language="en_US">
        <synopsis>
            Gets IAX peer information.
        </synopsis>
        <syntax>
            <parameter name="peername" required="true">
                <enumlist>
                    <enum name="CURRENTCHANNEL">
                        <para>If <replaceable>peername</replaceable> is specified to this value, return the IP address of the
                        endpoint of the current channel</para>
                    </enum>
                </enumlist>
            </parameter>
            <parameter name="item">
                <para>If <replaceable>peername</replaceable> is specified, valid items are:</para>
                <enumlist>
                    <enum name="ip">
                        <para>(default) The IP address.</para>
                    </enum>
                    <enum name="status">
                        <para>The peer's status (if <literal>qualify=yes</literal>)</para>
                    </enum>
                    <enum name="mailbox">
                        <para>The configured mailbox.</para>
                    </enum>
                    <enum name="context">
                        <para>The configured context.</para>
                    </enum>
                    <enum name="expire">
                        <para>The epoch time of the next expire.</para>
                    </enum>
                    <enum name="dynamic">
                        <para>Is it dynamic? (yes/no).</para>
                    </enum>
                    <enum name="callerid_name">
                        <para>The configured Caller ID name.</para>
                    </enum>
                    <enum name="callerid_num">
                        <para>The configured Caller ID number.</para>
                    </enum>
                    <enum name="codecs">
                        <para>The configured codecs.</para>
                    </enum>
                    <enum name="codec[x]">
                        <para>Preferred codec index number <replaceable>x</replaceable> (beginning
                        with <literal>0</literal>)</para>
                    </enum>
                </enumlist>
            </parameter>
        </syntax>
        <description>
            <para>Gets information associated with the specified IAX2 peer.</para>
        </description>
    </function>
    <function name="IAXVAR" language="en_US">
        <synopsis>
            Sets or retrieves a remote variable.
        </synopsis>
        <syntax>
            <parameter name="varname" required="true" />
        </syntax>
        <description>
            <para>Gets or sets a variable that is sent to a remote IAX2 peer during call setup.</para>
        </description>
    </function>
    <info name="CHANNEL" language="en_US" tech="IAX">
        <enumlist>
            <enum name="osptoken">
                <para>R/O Get the peer's osptoken.</para>
            </enum>
            <enum name="peerip">
                <para>R/O Get the peer's ip address.</para>
            </enum>
            <enum name="peername">
                <para>R/O Get the peer's username.</para>
            </enum>
            <enum name="secure_signaling">
                <para>R/O Get the if the IAX channel is secured.</para>
            </enum>
            <enum name="secure_media">
                <para>R/O Get the if the IAX channel is secured.</para>
            </enum>
        </enumlist>
    </info>
    <info name="Dial_Resource" language="en_US" tech="IAX2">
        <para>The general syntax is:</para>
        <para><literal>Dial(IAX2/[username[:password]@]peer[:port][/exten[@context]][/options]</literal></para>
        <para>IAX2 optionally allows modifiers to be specified after the extension.</para>
        <enumlist>
            <enum name="a">
                <para>Request auto answer (supporting equipment/configuration required)</para>
            </enum>
        </enumlist>
    </info>
    <manager name="IAXpeers" language="en_US">
        <synopsis>
            List IAX peers.
        </synopsis>
        <syntax>
            <xi:include xpointer="xpointer(/docs/manager[@name='Login']/syntax/parameter[@name='ActionID'])" />
        </syntax>
        <description>
        </description>
    </manager>
    <manager name="IAXpeerlist" language="en_US">
        <synopsis>
            List IAX Peers.
        </synopsis>
        <syntax>
            <xi:include xpointer="xpointer(/docs/manager[@name='Login']/syntax/parameter[@name='ActionID'])" />
        </syntax>
        <description>
            <para>List all the IAX peers.</para>
        </description>
    </manager>
    <manager name="IAXnetstats" language="en_US">
        <synopsis>
            Show IAX Netstats.
        </synopsis>
        <syntax />
        <description>
            <para>Show IAX channels network statistics.</para>
        </description>
    </manager>
    <manager name="IAXregistry" language="en_US">
        <synopsis>
            Show IAX registrations.
        </synopsis>
        <syntax>
            <xi:include xpointer="xpointer(/docs/manager[@name='Login']/syntax/parameter[@name='ActionID'])" />
        </syntax>
        <description>
            <para>Show IAX registrations.</para>
        </description>
    </manager>
 ***/
 
/* 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
 
 
#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
 
#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 iax2_codec_pref prefs_global;
 
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 */
 
#define DEFAULT_CONTEXT "default"
 
static char default_parkinglot[AST_MAX_CONTEXT];
 
static char language[MAX_LANGUAGE] = "";
static char regcontext[AST_MAX_CONTEXT] = "";
 
static struct stasis_subscription *network_change_sub; /*!< subscription id for network change events */
static struct stasis_subscription *acl_change_sub; /*!< subscription id for ACL change events */
static int network_change_sched_id = -1;
 
static int maxauthreq = 3;
static int max_retries = 4;
static int ping_time = 21;
static int lagrq_time = 10;
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 = 0;
static int autokill = 0;
static int iaxcompat = 0;
static int last_authmethod = 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 struct {
    unsigned int tos;
    unsigned int cos;
} qos = { 0, 0 };
 
static int min_reg_expire;
static int max_reg_expire;
 
static int srvlookup = 0;
 
static struct ast_timer *timer;             /* Timer for trunking */
 
static struct ast_netsock_list *netsock;
static struct ast_netsock_list *outsock;        /*!< used if sourceaddress specified and bindaddr == INADDR_ANY */
static int defaultsockfd = -1;
 
static 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_SLIN &      \
                     ~AST_FORMAT_SLIN16 &    \
                     ~AST_FORMAT_SIREN7 &       \
                     ~AST_FORMAT_SIREN14 &      \
                     ~AST_FORMAT_G719 &         \
                     ~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)
 
 
#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... */
 
/*! \brief Name of effective auth method */
static const char *auth_method_labels[] = {
    [0] = "none",
    [IAX_AUTH_PLAINTEXT] = "plaintext",
    [IAX_AUTH_MD5] = "MD5",
    [IAX_AUTH_RSA] = "RSA",
};
 
/* Max length is length of |RSA|MD5|plaintext (18 + 1 for NUL = 19) */
#define AUTH_METHOD_NAMES_BUFSIZE 19
 
/*!
 * \brief Get names of all auth methods
 * \param Bit field of auth methods
 * \param[out] buf Buffer into which to write the names. Must be of size AUTH_METHOD_NAMES_BUFSIZE.
 * \return Auth methods name
 */
static char *auth_method_names(int authmethods, char *restrict buf)
{
    char *pos = buf;
 
    *pos = '\0';
 
    if (authmethods & IAX_AUTH_RSA) {
        pos += sprintf(pos, "|RSA");
    }
    if (authmethods & IAX_AUTH_MD5) {
        pos += sprintf(pos, "|MD5");
    }
    if (authmethods & IAX_AUTH_PLAINTEXT) {
        pos += sprintf(pos, "|plaintext");
    }
 
    if (pos == buf) { /* No auth methods */
        strcpy(buf, "none");
        return buf;
    }
 
    return buf + 1; /* Skip leading | */
}
 
/* if a pvt has encryption setup done and is running on the call */
#define IAX_CALLENCRYPTED(pvt) \
    (ast_test_flag64(pvt, IAX_ENCRYPTED) && ast_test_flag64(pvt, IAX_KEYPOPULATED))
 
#define IAX_DEBUGDIGEST(msg, key) do { \
        int idx; \
        char digest[33] = ""; \
        \
        if (!iaxdebug) \
            break; \
        \
        for (idx = 0; idx < 16; idx++) \
            sprintf(digest + (idx << 1), "%02hhx", (unsigned char) key[idx]); \
        \
        ast_log(LOG_NOTICE, msg " IAX_COMMAND_RTKEY to rotate key to '%s'\n", digest); \
    } while(0)
 
static struct io_context *io;
static struct ast_sched_context *sched;
 
static iax2_format 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 int iax2_authmethods = 0;
 
static struct ast_flags64 globalflags = { 0 };
 
static pthread_t netthreadid = AST_PTHREADT_NULL;
 
enum iax2_state {
    IAX_STATE_STARTED =         (1 << 0),
    IAX_STATE_AUTHENTICATED =   (1 << 1),
    IAX_STATE_TBD =             (1 << 2),
};
 
struct iax2_context {
    char context[AST_MAX_CONTEXT];
    struct iax2_context *next;
};
 
 
#define IAX_HASCALLERID         (uint64_t)(1LLU << 0)    /*!< CallerID has been specified */
#define IAX_DELME               (uint64_t)(1LLU << 1)    /*!< Needs to be deleted */
#define IAX_TEMPONLY            (uint64_t)(1LLU << 2)    /*!< Temporary (realtime) */
#define IAX_TRUNK               (uint64_t)(1LLU << 3)    /*!< Treat as a trunk */
#define IAX_NOTRANSFER          (uint64_t)(1LLU << 4)    /*!< Don't native bridge */
#define IAX_USEJITTERBUF        (uint64_t)(1LLU << 5)    /*!< Use jitter buffer */
#define IAX_DYNAMIC             (uint64_t)(1LLU << 6)    /*!< dynamic peer */
#define IAX_SENDANI             (uint64_t)(1LLU << 7)    /*!< Send ANI along with CallerID */
#define IAX_RTSAVE_SYSNAME      (uint64_t)(1LLU << 8)    /*!< Save Systname on Realtime Updates */
#define IAX_ALREADYGONE         (uint64_t)(1LLU << 9)    /*!< Already disconnected */
#define IAX_PROVISION           (uint64_t)(1LLU << 10)   /*!< This is a provisioning request */
#define IAX_QUELCH              (uint64_t)(1LLU << 11)   /*!< Whether or not we quelch audio */
#define IAX_ENCRYPTED           (uint64_t)(1LLU << 12)   /*!< Whether we should assume encrypted tx/rx */
#define IAX_KEYPOPULATED        (uint64_t)(1LLU << 13)   /*!< Whether we have a key populated */
#define IAX_CODEC_USER_FIRST    (uint64_t)(1LLU << 14)   /*!< are we willing to let the other guy choose the codec? */
#define IAX_CODEC_NOPREFS       (uint64_t)(1LLU << 15)   /*!< Force old behaviour by turning off prefs */
#define IAX_CODEC_NOCAP         (uint64_t)(1LLU << 16)   /*!< only consider requested format and ignore capabilities*/
#define IAX_RTCACHEFRIENDS      (uint64_t)(1LLU << 17)   /*!< let realtime stay till your reload */
#define IAX_RTUPDATE            (uint64_t)(1LLU << 18)   /*!< Send a realtime update */
#define IAX_RTAUTOCLEAR         (uint64_t)(1LLU << 19)   /*!< erase me on expire */
#define IAX_RTIGNOREREGEXPIRE   (uint64_t)(1LLU << 21)   /*!< When using realtime, ignore registration expiration */
#define IAX_TRUNKTIMESTAMPS     (uint64_t)(1LLU << 22)   /*!< Send trunk timestamps */
#define IAX_TRANSFERMEDIA       (uint64_t)(1LLU << 23)   /*!< When doing IAX2 transfers, transfer media only */
#define IAX_MAXAUTHREQ          (uint64_t)(1LLU << 24)   /*!< Maximum outstanding AUTHREQ restriction is in place */
#define IAX_DELAYPBXSTART       (uint64_t)(1LLU << 25)   /*!< Don't start a PBX on the channel until the peer sends us a response, so that we've achieved a three-way handshake with them before sending voice or anything else */
#define IAX_ALLOWFWDOWNLOAD     (uint64_t)(1LLU << 26)   /*!< Allow the FWDOWNL command? */
#define IAX_IMMEDIATE           (uint64_t)(1LLU << 27)   /*!< Allow immediate off-hook to extension s */
#define IAX_SENDCONNECTEDLINE   (uint64_t)(1LLU << 28)   /*!< Allow sending of connected line updates */
#define IAX_RECVCONNECTEDLINE   (uint64_t)(1LLU << 29)   /*!< Allow receiving of connected line updates */
#define IAX_FORCE_ENCRYPT       (uint64_t)(1LLU << 30)   /*!< Forces call encryption, if encryption not possible hangup */
#define IAX_SHRINKCALLERID      (uint64_t)(1LLU << 31)   /*!< Turn on and off caller id shrinking */
static int global_rtautoclear = 120;
 
static int reload_config(int forced_reload);
 
/*!
 * \brief Call token validation settings.
 */
enum calltoken_peer_enum {
    /*! \brief Default calltoken required unless the ip is in the ignorelist */
    CALLTOKEN_DEFAULT = 0,
    /*! \brief Require call token validation. */
    CALLTOKEN_YES = 1,
    /*! \brief Require call token validation after a successful registration
     *         using call token validation occurs. */
    CALLTOKEN_AUTO = 2,
    /*! \brief Do not require call token validation. */
    CALLTOKEN_NO = 3,
};
 
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);
        AST_STRING_FIELD(parkinglot);           /*!< Default parkinglot for device */
    );
 
    int authmethods;
    int encmethods;
    int amaflags;
    int adsi;
    uint64_t flags;
    iax2_format capability;
    int maxauthreq; /*!< Maximum allowed outstanding AUTHREQs */
    int curauthreq; /*!< Current number of outstanding AUTHREQs */
    struct iax2_codec_pref prefs;
    struct ast_acl_list *acl;
    struct iax2_context *contexts;
    struct ast_variable *vars;
    enum calltoken_peer_enum calltoken_required;        /*!< Is calltoken validation required or not, can be YES, NO, or AUTO */
};
 
struct iax2_peer {
    AST_DECLARE_STRING_FIELDS(
        AST_STRING_FIELD(name);
        AST_STRING_FIELD(username);
        AST_STRING_FIELD(description);      /*!< Description of the peer */
        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 */
        AST_STRING_FIELD(parkinglot);   /*!< Default parkinglot for device */
    );
    struct iax2_codec_pref prefs;
    struct ast_dnsmgr_entry *dnsmgr;        /*!< DNS refresh manager */
    struct ast_sockaddr addr;
    int formats;
    int sockfd;                 /*!< Socket to use for transmission */
    struct ast_sockaddr mask;
    int adsi;
    uint64_t flags;
 
    /* Dynamic Registration fields */
    struct ast_sockaddr 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 */
    iax2_format 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 */
    uint16_t maxcallno;             /*!< Max call number limit for this peer.  Set on registration */
 
    struct ast_mwi_subscriber *mwi_event_sub;   /*!< This subscription lets pollmailboxes know which mailboxes need to be polled */
 
    struct ast_acl_list *acl;
    enum calltoken_peer_enum calltoken_required;    /*!< Is calltoken validation required or not, can be YES, NO, or AUTO */
 
    struct ast_endpoint *endpoint; /*!< Endpoint structure for this peer */
};
 
#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 ast_sockaddr 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);
 
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 ast_sockaddr addr;       /*!< Who we connect to for registration purposes */
    char username[80];
    char secret[80];            /*!< Password or key name in []'s */
    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 ast_sockaddr us;         /*!< Who the server thinks we are */
    struct ast_dnsmgr_entry *dnsmgr;    /*!< DNS refresh manager */
    AST_LIST_ENTRY(iax2_registry) entry;
    int port;
    char hostname[];
};
 
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
 
/* used for first_iax_message and last_iax_message.  If this bit is set it was TX, else RX */
#define MARK_IAX_SUBCLASS_TX    0x8000
 
static int iaxthreadcount = DEFAULT_THREAD_COUNT;
static int iaxmaxthreadcount = DEFAULT_MAX_THREAD_COUNT;
static int iaxdynamicthreadcount = 0;
static int iaxdynamicthreadnum = 0;
static int iaxactivethreadcount = 0;
 
struct iax_rr {
    int jitter;
    int losspct;
    int losscnt;
    int packets;
    int delay;
    int dropped;
    int ooo;
};
 
struct iax2_pvt_ref;
 
/* We use the high order bit as the validated flag, and the lower 15 as the
 * actual call number */
typedef uint16_t callno_entry;
 
struct chan_iax2_pvt {
    /*! Socket to send/receive on for this call */
    int sockfd;
    /*! ast_callid bound to dialog */
    ast_callid callid;
    /*! Last received voice format */
    iax2_format voiceformat;
    /*! Last received video format */
    iax2_format videoformat;
    /*! Last sent voice format */
    iax2_format svoiceformat;
    /*! Last sent video format */
    iax2_format svideoformat;
    /*! What we are capable of sending */
    iax2_format capability;
    /*! Last received timestamp */
    unsigned int last;
    /*! Last sent timestamp - never send the same timestamp twice in a single call */
    unsigned int lastsent;
    /*! Timestamp of the last video frame sent */
    unsigned int lastvsent;
    /*! Next outgoing timestamp if everything is good */
    unsigned int nextpred;
    /*! iax frame subclass that began iax2_pvt entry. 0x8000 bit is set on TX */
    int first_iax_message;
    /*! Last iax frame subclass sent or received for a iax2_pvt. 0x8000 bit is set on TX */
    int last_iax_message;
    /*! 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 ast_sockaddr addr;
    /*! Actual used codec preferences */
    struct iax2_codec_pref prefs;
    /*! Requested codec preferences */
    struct iax2_codec_pref rprefs;
    /*! Our call number */
    unsigned short callno;
    /*! Our callno_entry entry */
    callno_entry callno_entry;
    /*! Peer callno */
    unsigned short peercallno;
    /*! Negotiated format, this is only used to remember what format was
        chosen for an unauthenticated call so that the channel can get
        created later using the right format */
    iax2_format chosenformat;
    /*! Peer selected format */
    iax2_format peerformat;
    /*! Peer capability */
    iax2_format 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);
        /*! received OSP token */
        AST_STRING_FIELD(osptoken);
        /*! Default parkinglot */
        AST_STRING_FIELD(parkinglot);
    );
    /*! AUTHREJ all AUTHREP frames */
    int authrej;
    /*! permitted authentication methods */
    int authmethods;
    /*! effective authentication method */
    int eff_auth_method;
    /*! permitted encryption methods */
    int encmethods;
    /*! Encryption AES-128 Key */
    ast_aes_encrypt_key ecx;
    /*! Decryption AES-128 Key corresponding to ecx */
    ast_aes_decrypt_key mydcx;
    /*! Decryption AES-128 Key used to decrypt peer frames */
    ast_aes_decrypt_key dcx;
    /*! scheduler id associated with iax_key_rotate
     * for encrypted calls*/
    int keyrotateid;
    /*! 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 */
    uint64_t flags;
    int adsi;
 
    /*! Transferring status */
    enum iax_transfer_state transferring;
    /*! Transfer identifier */
    int transferid;
    /*! Who we are IAX transferring to */
    struct ast_sockaddr transfer;
    /*! What's the new call number for the transfer */
    unsigned short transfercallno;
    /*! Transfer encrypt AES-128 Key */
    ast_aes_encrypt_key tdcx;
 
    /*! Status of knowledge of peer ADSI capability */
    int peeradsicpe;
 
    /*! Callno of native bridge peer. (Valid if nonzero) */
    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 calling_ani2;
    int amaflags;
    AST_LIST_HEAD_NOLOCK(, iax2_dpcache) dpentries;
    /*! variables inherited from the user definition */
    struct ast_variable *vars;
    /*! variables transmitted in a NEW packet */
    struct ast_variable *iaxvars;
    /*! 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;
    /*! Destroying this call initiated. */
    int destroy_initiated;
    /*! num bytes used for calltoken ie, even an empty ie should contain 2 */
    unsigned char calltoken_ie_len;
    /*! hold all signaling frames from the pbx thread until we have a destination callno */
    char hold_signaling;
    /*! frame queue for signaling frames from pbx thread waiting for destination callno */
    AST_LIST_HEAD_NOLOCK(signaling_queue, signaling_queue_entry) signaling_queue;
};
 
struct signaling_queue_entry {
    struct ast_frame f;
    AST_LIST_ENTRY(signaling_queue_entry) next;
};
 
enum callno_type {
    CALLNO_TYPE_NORMAL,
    CALLNO_TYPE_TRUNK,
};
 
#define PTR_TO_CALLNO_ENTRY(a) ((uint16_t)(unsigned long)(a))
#define CALLNO_ENTRY_TO_PTR(a) ((void *)(unsigned long)(a))
 
#define CALLNO_ENTRY_SET_VALIDATED(a) ((a) |= 0x8000)
#define CALLNO_ENTRY_IS_VALIDATED(a)  ((a) & 0x8000)
#define CALLNO_ENTRY_GET_CALLNO(a)    ((a) & 0x7FFF)
 
struct call_number_pool {
    size_t capacity;
    size_t available;
    callno_entry numbers[IAX_MAX_CALLS / 2 + 1];
};
 
AST_MUTEX_DEFINE_STATIC(callno_pool_lock);
 
/*! table of available call numbers */
static struct call_number_pool callno_pool;
 
/*! table of available trunk call numbers */
static struct call_number_pool callno_pool_trunk;
 
/*!
 * \brief a list of frames that may need to be retransmitted
 *
 * \note The contents of this list do not need to be explicitly destroyed
 * on module unload.  This is because all active calls are destroyed, and
 * all frames in this queue will get destroyed as a part of that process.
 *
 * \note Contents protected by the iaxsl[] locks
 */
static AST_LIST_HEAD_NOLOCK(, iax_frame) frame_queue[IAX_MAX_CALLS];
 
static struct ast_taskprocessor *transmit_processor;
 
static int randomcalltokendata;
 
static time_t max_calltoken_delay = 10;
 
/*!
 * This module will get much higher performance when doing a lot of
 * user and peer lookups if the number of buckets is increased from 1.
 * However, to maintain old behavior for Asterisk 1.4, these are set to
 * 1 by default.  When using multiple buckets, search order through these
 * containers is considered random, so you will not be able to depend on
 * the order the entires are specified in iax.conf for matching order. */
#ifdef LOW_MEMORY
#define MAX_PEER_BUCKETS 17
#else
#define MAX_PEER_BUCKETS 563
#endif
static struct ao2_container *peers;
 
#define MAX_USER_BUCKETS MAX_PEER_BUCKETS
static struct ao2_container *users;
 
/*! Table containing peercnt objects for every ip address consuming a callno */
static struct ao2_container *peercnts;
 
/*! Table containing custom callno limit rules for a range of ip addresses. */
static struct ao2_container *callno_limits;
 
/*! Table containing ip addresses not requiring calltoken validation */
static struct ao2_container *calltoken_ignores;
 
static uint16_t DEFAULT_MAXCALLNO_LIMIT = 2048;
 
static uint16_t DEFAULT_MAXCALLNO_LIMIT_NONVAL = 8192;
 
static uint16_t global_maxcallno;
 
/*! Total num of call numbers allowed to be allocated without calltoken validation */
static uint16_t global_maxcallno_nonval;
 
static uint16_t total_nonval_callno_used = 0;
 
/*! peer connection private, keeps track of all the call numbers
 *  consumed by a single ip address */
struct peercnt {
    /*! ip address consuming call numbers */
    struct ast_sockaddr addr;
    /*! Number of call numbers currently used by this ip address */
    uint16_t cur;
    /*! Max call numbers allowed for this ip address */
    uint16_t limit;
    /*! Specifies whether limit is set by a registration or not, if so normal
     *  limit setting rules do not apply to this address. */
    unsigned char reg;
};
 
/*! used by both callno_limits and calltoken_ignores containers */
struct addr_range {
    /*! ip address range for custom callno limit rule */
    struct ast_ha ha;
    /*! callno limit for this ip address range, only used in callno_limits container */
    uint16_t limit;
    /*! delete me marker for reloads */
    unsigned char delme;
};
 
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 ast_sockaddr *addr);
static struct iax2_user *realtime_user(const char *username, struct ast_sockaddr *addr);
 
static int ast_cli_netstats(struct mansession *s, int fd, int limit_fmt);
static char *complete_iax2_peers(const char *line, const char *word, int pos, int state, uint64_t flags);
static char *complete_iax2_unregister(const char *line, const char *word, int pos, int state);
 
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_pkt_buf {
    AST_LIST_ENTRY(iax2_pkt_buf) entry;
    size_t len;
    unsigned char buf[1];
};
 
struct iax2_thread {
    AST_LIST_ENTRY(iax2_thread) list;
    enum iax2_thread_type type;
    enum iax2_thread_iostate iostate;
#ifdef SCHED_MULTITHREADED
    void (*schedfunc)(const void *);
    const void *scheddata;
#endif
#ifdef DEBUG_SCHED_MULTITHREAD
    char curfunc[80];
#endif
    int actions;
    pthread_t threadid;
    int threadnum;
    struct ast_sockaddr ioaddr;
    unsigned char readbuf[4096];
    unsigned char *buf;
    ssize_t buf_len;
    size_t buf_size;
    int iofd;
    time_t checktime;
    ast_mutex_t lock;
    ast_cond_t cond;
    ast_mutex_t init_lock;
    ast_cond_t init_cond;
    /*! if this thread is processing a full frame,
      some information about that frame will be stored
      here, so we can avoid dispatching any more full
      frames for that callno to other threads */
    struct {
        unsigned short callno;
        struct ast_sockaddr addr;
        unsigned char type;
        unsigned char csub;
    } ffinfo;
    /*! Queued up full frames for processing.  If more full frames arrive for
     *  a call which this thread is already processing a full frame for, they
     *  are queued up here. */
    AST_LIST_HEAD_NOLOCK(, iax2_pkt_buf) full_frames;
    unsigned char stop;
};
 
/* 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 iax2_destroy(int callno);
 
static void signal_condition(ast_mutex_t *lock, ast_cond_t *cond)
{
    ast_mutex_lock(lock);
    ast_cond_signal(cond);
    ast_mutex_unlock(lock);
}
 
/*!
 * \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];
 
static ast_callid iax_pvt_callid_get(int callno)
{
    return iaxs[callno]->callid;
}
 
static void iax_pvt_callid_set(int callno, ast_callid callid)
{
    iaxs[callno]->callid = callid;
}
 
static void iax_pvt_callid_new(int callno)
{
    ast_callid callid = ast_create_callid();
    char buffer[AST_CALLID_BUFFER_LENGTH];
    ast_callid_strnprint(buffer, sizeof(buffer), callid);
    iax_pvt_callid_set(callno, callid);
}
 
/*!
 * \brief Another container of iax2_pvt structures
 *
 * Active IAX2 pvt structs are also stored in this container, if they are a part
 * of an active call where we know the remote side's call number.  The reason
 * for this is that incoming media frames do not contain our call number.  So,
 * instead of having to iterate the entire iaxs array, we use this container to
 * look up calls where the remote side is using a given call number.
 */
static struct ao2_container *iax_peercallno_pvts;
 
/*!
 * \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[ARRAY_LEN(iaxs)];
 
/*!
 * \brief Another container of iax2_pvt structures
 *
 * Active IAX2 pvt structs used during transfering a call are stored here.
 */
static struct ao2_container *iax_transfercallno_pvts;
 
/* 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    (IAX_MAX_CALLS / 2)
 
/* Debug routines... */
static struct ast_sockaddr debugaddr;
 
static void iax_outputframe(struct iax_frame *f, struct ast_iax2_full_hdr *fhi, int rx, struct ast_sockaddr *addr, int datalen)
{
    if (iaxdebug ||
        (addr && !ast_sockaddr_isnull(&debugaddr) &&
        (!ast_sockaddr_port(&debugaddr) ||
          ast_sockaddr_port(&debugaddr) == ast_sockaddr_port(addr)) &&
          !ast_sockaddr_cmp_addr(&debugaddr, addr))) {
 
        if (iaxdebug) {
            iax_showframe(f, fhi, rx, addr, datalen);
        } else {
            iaxdebug = 1;
            iax_showframe(f, fhi, rx, addr, datalen);
            iaxdebug = 0;
        }
    }
}
 
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 __attribute__((format(printf, 1, 2))) 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, "%s", buf);
}
 
static void __attribute__((format(printf, 1, 2))) 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, "%s", buf);
}
 
static void __attribute__((format(printf, 1, 2))) 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("%s", buf);
}
 
static int expire_registry(const void *data);
static int iax2_answer(struct ast_channel *c);
static int iax2_call(struct ast_channel *c, const char *dest, int timeout);
static int iax2_devicestate(const char *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 ast_sockaddr *end, int sockfd, const 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 iax2_sendtext(struct ast_channel *c, const char *text);
static int iax2_setoption(struct ast_channel *c, int option, void *data, int datalen);
static int iax2_queryoption(struct ast_channel *c, int option, void *data, int *datalen);
static int iax2_transfer(struct ast_channel *c, const char *dest);
static int iax2_write(struct ast_channel *c, struct ast_frame *f);
static int iax2_sched_add(struct ast_sched_context *sched, int when, ast_sched_cb callback, const void *data);
 
static int send_trunk(struct iax2_trunk_peer *tpeer, struct timeval *now);
static int send_command(struct chan_iax2_pvt *, char, int, unsigned int, const unsigned char *, int, int);
static int send_command_final(struct chan_iax2_pvt *, char, int, unsigned int, const unsigned char *, int, int);
static int send_command_immediate(struct chan_iax2_pvt *, char, int, unsigned int, const unsigned char *, int, int);
static int send_command_locked(unsigned short callno, char, int, unsigned int, const unsigned char *, int, int);
static int send_command_transfer(struct chan_iax2_pvt *, char, int, unsigned int, const unsigned char *, int);
static struct ast_channel *iax2_request(const char *type, struct ast_format_cap *cap, const struct ast_assigned_ids *assignedids, const struct ast_channel *requestor, const char *data, int *cause);
static struct ast_frame *iax2_read(struct ast_channel *c);
static struct iax2_peer *build_peer(const char *name, struct ast_variable *v, struct ast_variable *alt, int temponly);
static struct iax2_user *build_user(const char *name, struct ast_variable *v, struct ast_variable *alt, int temponly);
static void realtime_update_peer(const char *peername, struct ast_sockaddr *sockaddr, time_t regtime);
static void *iax2_dup_variable_datastore(void *);
static void prune_peers(void);
static void prune_users(void);
static void iax2_free_variable_datastore(void *);
 
static int acf_channel_read(struct ast_channel *chan, const char *funcname, char *preparse, char *buf, size_t buflen);
static int decode_frame(ast_aes_decrypt_key *dcx, struct ast_iax2_full_hdr *fh, struct ast_frame *f, int *datalen);
static int encrypt_frame(ast_aes_encrypt_key *ecx, struct ast_iax2_full_hdr *fh, unsigned char *poo, int *datalen);
static void build_ecx_key(const unsigned char *digest, struct chan_iax2_pvt *pvt);
static void build_rand_pad(unsigned char *buf, ssize_t len);
static int get_unused_callno(enum callno_type type, int validated, callno_entry *entry);
static int replace_callno(const void *obj);
static void sched_delay_remove(struct ast_sockaddr *addr, callno_entry entry);
static void network_change_stasis_cb(void *data, struct stasis_subscription *sub, struct stasis_message *message);
static void acl_change_stasis_cb(void *data, struct stasis_subscription *sub, struct stasis_message *message);
 
static struct ast_channel_tech iax2_tech = {
    .type = "IAX2",
    .description = tdesc,
    .properties = AST_CHAN_TP_WANTSJITTER,
    .requester = iax2_request,
    .devicestate = iax2_devicestate,
    .send_digit_begin = iax2_digit_begin,
    .send_digit_end = iax2_digit_end,
    .send_text = iax2_sendtext,
    .send_image = iax2_sendimage,
    .send_html = iax2_sendhtml,
    .call = iax2_call,
    .hangup = iax2_hangup,
    .answer = iax2_answer,
    .read = iax2_read,
    .write = iax2_write,
    .write_video = iax2_write,
    .indicate = iax2_indicate,
    .setoption = iax2_setoption,
    .queryoption = iax2_queryoption,
    .transfer = iax2_transfer,
    .fixup = iax2_fixup,
    .func_channel_read = acf_channel_read,
};
 
/*!
 * \internal
 * \brief Obtain the owner channel lock if the owner exists.
 *
 * \param callno IAX2 call id.
 *
 * \note Assumes the iaxsl[callno] lock is already obtained.
 *
 * \note
 * IMPORTANT NOTE!!!  Any time this function is used, even if
 * iaxs[callno] was valid before calling it, it may no longer be
 * valid after calling it.  This function may unlock and lock
 * the mutex associated with this callno, meaning that another
 * thread may grab it and destroy the call.
 */
static void iax2_lock_owner(int callno)
{
    for (;;) {
        if (!iaxs[callno] || !iaxs[callno]->owner) {
            /* There is no owner lock to get. */
            break;
        }
        if (!ast_channel_trylock(iaxs[callno]->owner)) {
            /* We got the lock */
            break;
        }
        /* Avoid deadlock by pausing and trying again */
        DEADLOCK_AVOIDANCE(&iaxsl[callno]);
    }
}
 
/*!
 * \internal
 * \brief Check if a control subtype is allowed on the wire.
 *
 * \param subtype Control frame subtype to check if allowed to/from the wire.
 *
 * \retval non-zero if allowed.
 */
static int iax2_is_control_frame_allowed(int subtype)
{
    enum ast_control_frame_type control = subtype;
    int is_allowed;
 
    /*
     * Note: If we compare the enumeration type, which does not have any
     * negative constants, the compiler may optimize this code away.
     * Therefore, we must perform an integer comparison here.
     */
    if (subtype == -1) {
        return -1;
    }
 
    /* Default to not allowing control frames to pass. */
    is_allowed = 0;
 
    /*
     * The switch default is not present in order to take advantage
     * of the compiler complaining of a missing enum case.
     */
    switch (control) {
    /*
     * These control frames make sense to send/receive across the link.
     */
    case AST_CONTROL_HANGUP:
    case AST_CONTROL_RING:
    case AST_CONTROL_RINGING:
    case AST_CONTROL_ANSWER:
    case AST_CONTROL_BUSY:
    case AST_CONTROL_TAKEOFFHOOK:
    case AST_CONTROL_OFFHOOK:
    case AST_CONTROL_CONGESTION:
    case AST_CONTROL_FLASH:
    case AST_CONTROL_WINK:
    case AST_CONTROL_OPTION:
    case AST_CONTROL_RADIO_KEY:
    case AST_CONTROL_RADIO_UNKEY:
    case AST_CONTROL_PROGRESS:
    case AST_CONTROL_PROCEEDING:
    case AST_CONTROL_HOLD:
    case AST_CONTROL_UNHOLD:
    case AST_CONTROL_VIDUPDATE:
    case AST_CONTROL_CONNECTED_LINE:
    case AST_CONTROL_REDIRECTING:
    case AST_CONTROL_T38_PARAMETERS:
    case AST_CONTROL_AOC:
    case AST_CONTROL_INCOMPLETE:
    case AST_CONTROL_MCID:
        is_allowed = -1;
        break;
 
    /*
     * These control frames do not make sense to send/receive across the link.
     */
    case _XXX_AST_CONTROL_T38:
        /* The control value is deprecated in favor of AST_CONTROL_T38_PARAMETERS. */
    case AST_CONTROL_SRCUPDATE:
        /* Across an IAX link the source is still the same. */
    case AST_CONTROL_TRANSFER:
        /* A success/fail status report from calling ast_transfer() on this machine. */
    case AST_CONTROL_CC:
        /* The payload contains pointers that are valid for the sending machine only. */
    case AST_CONTROL_SRCCHANGE:
        /* Across an IAX link the source is still the same. */
    case AST_CONTROL_READ_ACTION:
        /* The action can only be done by the sending machine. */
    case AST_CONTROL_END_OF_Q:
        /* This frame would cause the call to unexpectedly hangup. */
    case AST_CONTROL_UPDATE_RTP_PEER:
        /* Only meaningful across a bridge on this machine for direct-media exchange. */
    case AST_CONTROL_PVT_CAUSE_CODE:
        /* Intended only for the sending machine's local channel structure. */
    case AST_CONTROL_MASQUERADE_NOTIFY:
        /* Intended only for masquerades when calling ast_indicate_data(). */
    case AST_CONTROL_STREAM_TOPOLOGY_REQUEST_CHANGE:
        /* Intended only for internal stream topology manipulation. */
    case AST_CONTROL_STREAM_TOPOLOGY_CHANGED:
        /* Intended only for internal stream topology change notification. */
    case AST_CONTROL_STREAM_TOPOLOGY_SOURCE_CHANGED:
    case AST_CONTROL_STREAM_STOP:
    case AST_CONTROL_STREAM_SUSPEND:
    case AST_CONTROL_STREAM_RESTART:
    case AST_CONTROL_STREAM_REVERSE:
    case AST_CONTROL_STREAM_FORWARD:
        /* None of these playback stream control frames should go across the link. */
    case AST_CONTROL_RECORD_CANCEL:
    case AST_CONTROL_RECORD_STOP:
    case AST_CONTROL_RECORD_SUSPEND:
    case AST_CONTROL_RECORD_MUTE:
        /* None of these media recording control frames should go across the link. */
        break;
    }
    return is_allowed;
}
 
static void network_change_stasis_subscribe(void)
{
    if (!network_change_sub) {
        network_change_sub = stasis_subscribe(ast_system_topic(),
            network_change_stasis_cb, NULL);
        stasis_subscription_accept_message_type(network_change_sub, ast_network_change_type());
        stasis_subscription_set_filter(network_change_sub, STASIS_SUBSCRIPTION_FILTER_SELECTIVE);
    }
}
 
static void network_change_stasis_unsubscribe(void)
{
    network_change_sub = stasis_unsubscribe_and_join(network_change_sub);
}
 
static void acl_change_stasis_subscribe(void)
{
    if (!acl_change_sub) {
        acl_change_sub = stasis_subscribe(ast_security_topic(),
            acl_change_stasis_cb, NULL);
        stasis_subscription_accept_message_type(acl_change_sub, ast_named_acl_change_type());
        stasis_subscription_set_filter(acl_change_sub, STASIS_SUBSCRIPTION_FILTER_SELECTIVE);
    }
}
 
static void acl_change_stasis_unsubscribe(void)
{
    acl_change_sub = stasis_unsubscribe_and_join(acl_change_sub);
}
 
static int network_change_sched_cb(const void *data)
{
    struct iax2_registry *reg;
    network_change_sched_id = -1;
    AST_LIST_LOCK(&registrations);
    AST_LIST_TRAVERSE(&registrations, reg, entry) {
        iax2_do_register(reg);
    }
    AST_LIST_UNLOCK(&registrations);
 
    return 0;
}
 
static void network_change_stasis_cb(void *data, struct stasis_subscription *sub,
    struct stasis_message *message)
{
    /* This callback is only concerned with network change messages from the system topic. */
    if (stasis_message_type(message) != ast_network_change_type()) {
        return;
    }
 
    ast_verb(1, "IAX, got a network change message, renewing all IAX registrations.\n");
    if (network_change_sched_id == -1) {
        network_change_sched_id = iax2_sched_add(sched, 1000, network_change_sched_cb, NULL);
    }
}
 
static void acl_change_stasis_cb(void *data, struct stasis_subscription *sub,
    struct stasis_message *message)
{
    if (stasis_message_type(message) != ast_named_acl_change_type()) {
        return;
    }
 
    ast_log(LOG_NOTICE, "Reloading chan_iax2 in response to ACL change event.\n");
    reload_config(1);
}
 
static const struct ast_datastore_info iax2_variable_datastore_info = {
    .type = "IAX2_VARIABLE",
    .duplicate = iax2_dup_variable_datastore,
    .destroy = iax2_free_variable_datastore,
};
 
static void *iax2_dup_variable_datastore(void *old)
{
    AST_LIST_HEAD(, ast_var_t) *oldlist = old, *newlist;
    struct ast_var_t *oldvar, *newvar;
 
    newlist = ast_calloc(sizeof(*newlist), 1);
    if (!newlist) {
        ast_log(LOG_ERROR, "Unable to duplicate iax2 variables\n");
        return NULL;
    }
 
    AST_LIST_HEAD_INIT(newlist);
    AST_LIST_LOCK(oldlist);
    AST_LIST_TRAVERSE(oldlist, oldvar, entries) {
        newvar = ast_var_assign(ast_var_name(oldvar), ast_var_value(oldvar));
        if (newvar)
            AST_LIST_INSERT_TAIL(newlist, newvar, entries);
        else
            ast_log(LOG_ERROR, "Unable to duplicate iax2 variable '%s'\n", ast_var_name(oldvar));
    }
    AST_LIST_UNLOCK(oldlist);
    return newlist;
}
 
static void iax2_free_variable_datastore(void *old)
{
    AST_LIST_HEAD(, ast_var_t) *oldlist = old;
    struct ast_var_t *oldvar;
 
    AST_LIST_LOCK(oldlist);
    while ((oldvar = AST_LIST_REMOVE_HEAD(oldlist, entries))) {
        ast_free(oldvar);
    }
    AST_LIST_UNLOCK(oldlist);
    AST_LIST_HEAD_DESTROY(oldlist);
    ast_free(oldlist);
}
 
 
/* WARNING: insert_idle_thread should only ever be called within the
 * context of an iax2_process_thread() thread.
 */
static void insert_idle_thread(struct iax2_thread *thread)
{
    if (thread->type == IAX_THREAD_TYPE_DYNAMIC) {
        AST_LIST_LOCK(&dynamic_list);
        AST_LIST_INSERT_TAIL(&dynamic_list, thread, list);
        AST_LIST_UNLOCK(&dynamic_list);
    } else {
        AST_LIST_LOCK(&idle_list);
        AST_LIST_INSERT_TAIL(&idle_list, thread, list);
        AST_LIST_UNLOCK(&idle_list);
    }
 
    return;
}
 
static struct iax2_thread *find_idle_thread(void)
{
    struct iax2_thread *thread = NULL;
 
    /* Pop the head of the idle list off */
    AST_LIST_LOCK(&idle_list);
    thread = AST_LIST_REMOVE_HEAD(&idle_list, list);
    AST_LIST_UNLOCK(&idle_list);
 
    /* If we popped a thread off the idle list, just return it */
    if (thread) {
        memset(&thread->ffinfo, 0, sizeof(thread->ffinfo));
        return thread;
    }
 
    /* Pop the head of the dynamic list off */
    AST_LIST_LOCK(&dynamic_list);
    thread = AST_LIST_REMOVE_HEAD(&dynamic_list, list);
    AST_LIST_UNLOCK(&dynamic_list);
 
    /* If we popped a thread off the dynamic list, just return it */
    if (thread) {
        memset(&thread->ffinfo, 0, sizeof(thread->ffinfo));
        return thread;
    }
 
    /* If we can't create a new dynamic thread for any reason, return no thread at all */
    if (iaxdynamicthreadcount >= iaxmaxthreadcount || !(thread = ast_calloc(1, sizeof(*thread))))
        return NULL;
 
    /* Set default values */
    ast_atomic_fetchadd_int(&iaxdynamicthreadcount, 1);
    thread->threadnum = ast_atomic_fetchadd_int(&iaxdynamicthreadnum, 1);
    thread->type = IAX_THREAD_TYPE_DYNAMIC;
 
    /* Initialize lock and condition */
    ast_mutex_init(&thread->lock);
    ast_cond_init(&thread->cond, NULL);
    ast_mutex_init(&thread->init_lock);
    ast_cond_init(&thread->init_cond, NULL);
    ast_mutex_lock(&thread->init_lock);
 
    /* Create thread and send it on it's way */
    if (ast_pthread_create_background(&thread->threadid, NULL, iax2_process_thread, thread)) {
        ast_cond_destroy(&thread->cond);
        ast_mutex_destroy(&thread->lock);
        ast_mutex_unlock(&thread->init_lock);
        ast_cond_destroy(&thread->init_cond);
        ast_mutex_destroy(&thread->init_lock);
        ast_free(thread);
        return NULL;
    }
 
    /* this thread is not processing a full frame (since it is idle),
       so ensure that the field for the full frame call number is empty */
    memset(&thread->ffinfo, 0, sizeof(thread->ffinfo));
 
    /* Wait for the thread to be ready before returning it to the caller */
    ast_cond_wait(&thread->init_cond, &thread->init_lock);
 
    /* Done with init_lock */
    ast_mutex_unlock(&thread->init_lock);
 
    return thread;
}
 
#ifdef SCHED_MULTITHREADED
static int __schedule_action(void (*func)(const void *data), const void *data, const char *funcname)
{
    struct iax2_thread *thread;
    static time_t lasterror;
    time_t t;
 
    thread = find_idle_thread();
    if (thread != NULL) {
        thread->schedfunc = func;
        thread->scheddata = data;
        thread->iostate = IAX_IOSTATE_SCHEDREADY;
#ifdef DEBUG_SCHED_MULTITHREAD
        ast_copy_string(thread->curfunc, funcname, sizeof(thread->curfunc));
#endif
        signal_condition(&thread->lock, &thread->cond);
        return 0;
    }
    time(&t);
    if (t != lasterror) {
        lasterror = t;
        ast_debug(1, "Out of idle IAX2 threads for scheduling! (%s)\n", funcname);
    }
 
    return -1;
}
#define schedule_action(func, data) __schedule_action(func, data, __PRETTY_FUNCTION__)
#endif
 
static int iax2_sched_replace(int id, struct ast_sched_context *con, int when,
        ast_sched_cb callback, const void *data)
{
    return ast_sched_replace(id, con, when, callback, data);
}
 
static int iax2_sched_add(struct ast_sched_context *con, int when,
        ast_sched_cb callback, const void *data)
{
    return ast_sched_add(con, when, callback, data);
}
 
/*!
 * \brief Acquire the iaxsl[callno] if call exists and not having ongoing hangup.
 * \param callno Call number to lock.
 * \retval 0 If call disappeared or has ongoing hangup procedure.
 * \retval 1 If call found and mutex is locked.
 */
static int iax2_lock_callno_unless_destroyed(int callno)
{
    ast_mutex_lock(&iaxsl[callno]);
 
    /* We acquired the lock; but the call was already destroyed (we came after full hang up procedures)
     * or destroy initiated (in middle of hang up procedure. */
    if (!iaxs[callno] || iaxs[callno]->destroy_initiated) {
        ast_debug(3, "I wanted to lock callno %d, but it is dead or going to die.\n", callno);
        ast_mutex_unlock(&iaxsl[callno]);
        return 0;
    }
 
    /* Lock acquired, and callno is alive and kicking. */
    return 1;
}
 
static int send_ping(const void *data);
 
static void __send_ping(const void *data)
{
    int callno = PTR_TO_CALLNO(data);
 
    if (iax2_lock_callno_unless_destroyed(callno) == 0) {
        ast_debug(3, "Hangup initiated on call %d, aborting __send_ping\n", callno);
        return;
    }
 
    /* Mark pingid as invalid scheduler id. */
    iaxs[callno]->pingid = -1;
 
    /* callno is now locked. */
    if (iaxs[callno]->peercallno) {
        /* Send PING packet. */
        send_command(iaxs[callno], AST_FRAME_IAX, IAX_COMMAND_PING, 0, NULL, 0, -1);
 
        /* Schedule sending next ping. */
        iaxs[callno]->pingid = iax2_sched_add(sched, ping_time * 1000, send_ping, data);
    }
 
    ast_mutex_unlock(&iaxsl[callno]);
}
 
static int send_ping(const void *data)
{
#ifdef SCHED_MULTITHREADED
    if (schedule_action(__send_ping, data))
#endif
        __send_ping(data);
 
    return 0;
}
 
static void encmethods_to_str(int e, struct ast_str **buf)
{
    ast_str_set(buf, 0, "(");
    if (e & IAX_ENCRYPT_AES128) {
        ast_str_append(buf, 0, "aes128");
    }
    if (e & IAX_ENCRYPT_KEYROTATE) {
        ast_str_append(buf, 0, ",keyrotate");
    }
    if (ast_str_strlen(*buf) > 1) {
        ast_str_append(buf, 0, ")");
    } else {
        ast_str_set(buf, 0, "No");
    }
}
 
static int get_encrypt_methods(const char *s)
{
    int e;
    if (!strcasecmp(s, "aes128"))
        e = IAX_ENCRYPT_AES128 | IAX_ENCRYPT_KEYROTATE;
    else if (ast_true(s))
        e = IAX_ENCRYPT_AES128 | IAX_ENCRYPT_KEYROTATE;
    else
        e = 0;
    return e;
}
 
static int send_lagrq(const void *data);
 
static void __send_lagrq(const void *data)
{
    int callno = PTR_TO_CALLNO(data);
 
    if (iax2_lock_callno_unless_destroyed(callno) == 0) {
        ast_debug(3, "Hangup initiated on call %d, aborting __send_lagrq\n", callno);
        return;
    }
 
    /* Mark lagid as invalid scheduler id. */
    iaxs[callno]->lagid = -1;
 
    /* callno is now locked. */
    if (iaxs[callno]->peercallno) {
        /* Send LAGRQ packet. */
        send_command(iaxs[callno], AST_FRAME_IAX, IAX_COMMAND_LAGRQ, 0, NULL, 0, -1);
 
        /* Schedule sending next lagrq. */
        iaxs[callno]->lagid = iax2_sched_add(sched, lagrq_time * 1000, send_lagrq, data);
    }
 
    ast_mutex_unlock(&iaxsl[callno]);
}
 
static int send_lagrq(const void *data)
{
#ifdef SCHED_MULTITHREADED
    if (schedule_action(__send_lagrq, data))
#endif
        __send_lagrq(data);
    return 0;
}
 
static unsigned char compress_subclass(iax2_format subclass)
{
    int x;
    int power=-1;
    /* If it's 64 or smaller, just return it */
    if (subclass < IAX_FLAG_SC_LOG)
        return subclass;
    /* Otherwise find its power */
    for (x = 0; x < IAX_MAX_SHIFT; x++) {
        if (subclass & (1LL << x)) {
            if (power > -1) {
                ast_log(LOG_WARNING, "Can't compress subclass %lld\n", (long long) subclass);
                return 0;
            } else
                power = x;
        }
    }
    return power | IAX_FLAG_SC_LOG;
}
 
static iax2_format uncompress_subclass(unsigned char csub)
{
    /* If the SC_LOG flag is set, return 2^csub otherwise csub */
    if (csub & IAX_FLAG_SC_LOG) {
        /* special case for 'compressed' -1 */
        if (csub == 0xff)
            return -1;
        else
            return 1LL << (csub & ~IAX_FLAG_SC_LOG & IAX_MAX_SHIFT);
    }
    else
        return csub;
}
 
static struct ast_format *codec_choose_from_prefs(struct iax2_codec_pref *pref, struct ast_format_cap *cap)
{
    int x;
    struct ast_format *found_format = NULL;
 
    for (x = 0; x < ARRAY_LEN(pref->order); ++x) {
        struct ast_format *pref_format;
        uint64_t pref_bitfield;
 
        pref_bitfield = iax2_codec_pref_order_value_to_format_bitfield(pref->order[x]);
        if (!pref_bitfield) {
            break;
        }
 
        pref_format = ast_format_compatibility_bitfield2format(pref_bitfield);
        if (!pref_format) {
            /* The bitfield is not associated with any format. */
            continue;
        }
        found_format = ast_format_cap_get_compatible_format(cap, pref_format);
        if (found_format) {
            break;
        }
    }
 
    if (found_format && (ast_format_get_type(found_format) == AST_MEDIA_TYPE_AUDIO)) {
        return found_format;
    }
 
    ast_debug(4, "Could not find preferred codec - Returning zero codec.\n");
    ao2_cleanup(found_format);
    return NULL;
}
 
static iax2_format iax2_codec_choose(struct iax2_codec_pref *pref, iax2_format formats)
{
    struct ast_format_cap *cap;
    struct ast_format *tmpfmt;
    iax2_format format = 0;
 
    if ((cap = ast_format_cap_alloc(AST_FORMAT_CAP_FLAG_DEFAULT))) {
        iax2_format_compatibility_bitfield2cap(formats, cap);
        tmpfmt = codec_choose_from_prefs(pref, cap);
        if (!tmpfmt) {
            ao2_ref(cap, -1);
            return 0;
        }
 
        format = ast_format_compatibility_format2bitfield(tmpfmt);
        ao2_ref(tmpfmt, -1);
        ao2_ref(cap, -1);
    }
 
    return format;
}
 
const char *iax2_getformatname(iax2_format format)
{
    struct ast_format *tmpfmt;
 
    tmpfmt = ast_format_compatibility_bitfield2format(format);
    if (!tmpfmt) {
        return "Unknown";
    }
 
    return ast_format_get_name(tmpfmt);
}
 
static const char *iax2_getformatname_multiple(iax2_format format, struct ast_str **codec_buf)
{
    struct ast_format_cap *cap = ast_format_cap_alloc(AST_FORMAT_CAP_FLAG_DEFAULT);
 
    if (!cap) {
        return "(Nothing)";
    }
    iax2_format_compatibility_bitfield2cap(format, cap);
    ast_format_cap_get_names(cap, codec_buf);
    ao2_ref(cap, -1);
 
    return ast_str_buffer(*codec_buf);
}
 
static int iax2_parse_allow_disallow(struct iax2_codec_pref *pref, iax2_format *formats, const char *list, int allowing)
{
    int res, i;
    struct ast_format_cap *cap;
 
    /* We want to add the formats to the cap in the preferred order */
    cap = ast_format_cap_alloc(AST_FORMAT_CAP_FLAG_DEFAULT);
    if (!cap || iax2_codec_pref_to_cap(pref, cap)) {
        ao2_cleanup(cap);
        return 1;
    }
 
    res = ast_format_cap_update_by_allow_disallow(cap, list, allowing);
 
    /* Adjust formats bitfield and pref list to match. */
    *formats = iax2_format_compatibility_cap2bitfield(cap);
    iax2_codec_pref_remove_missing(pref, *formats);
 
    for (i = 0; i < ast_format_cap_count(cap); i++) {
        struct ast_format *fmt = ast_format_cap_get_format(cap, i);
 
        iax2_codec_pref_append(pref, fmt, ast_format_cap_get_format_framing(cap, fmt));
        ao2_ref(fmt, -1);
    }
 
    ao2_ref(cap, -1);
 
    return res;
}
 
/*!
 * \note The only member of the peer passed here guaranteed to be set is the name field
 */
static int peer_hash_cb(const void *obj, const int flags)
{
    const struct iax2_peer *peer = obj;
    const char *name = obj;
 
    return ast_str_hash(flags & OBJ_KEY ? name : peer->name);
}
 
/*!
 * \note The only member of the peer passed here guaranteed to be set is the name field
 */
static int peer_cmp_cb(void *obj, void *arg, int flags)
{
    struct iax2_peer *peer = obj, *peer2 = arg;
    const char *name = arg;
 
    return !strcmp(peer->name, flags & OBJ_KEY ? name : peer2->name) ?
            CMP_MATCH | CMP_STOP : 0;
}
 
/*!
 * \note The only member of the user passed here guaranteed to be set is the name field
 */
static int user_hash_cb(const void *obj, const int flags)
{
    const struct iax2_user *user = obj;
    const char *name = obj;
 
    return ast_str_hash(flags & OBJ_KEY ? name : user->name);
}
 
/*!
 * \note The only member of the user passed here guaranteed to be set is the name field
 */
static int user_cmp_cb(void *obj, void *arg, int flags)
{
    struct iax2_user *user = obj, *user2 = arg;
    const char *name = arg;
 
    return !strcmp(user->name, flags & OBJ_KEY ? name : user2->name) ?
            CMP_MATCH | CMP_STOP : 0;
}
 
/*!
 * \note This funtion calls realtime_peer -> reg_source_db -> iax2_poke_peer -> find_callno,
 *       so do not call it with a pvt lock held.
 */
static struct iax2_peer *find_peer(const char *name, int realtime)
{
    struct iax2_peer *peer = NULL;
 
    peer = ao2_find(peers, name, OBJ_KEY);
 
    /* Now go for realtime if applicable */
    if (!peer && realtime) {
        peer = realtime_peer(name, NULL);
    }
    return peer;
}
 
static struct iax2_peer *peer_ref(struct iax2_peer *peer)
{
    ao2_ref(peer, +1);
    return peer;
}
 
static inline struct iax2_peer *peer_unref(struct iax2_peer *peer)
{
    ao2_ref(peer, -1);
    return NULL;
}
 
static struct iax2_user *find_user(const char *name)
{
    return ao2_find(users, name, OBJ_KEY);
}
 
static inline struct iax2_user *user_unref(struct iax2_user *user)
{
    ao2_ref(user, -1);
    return NULL;
}
 
static int iax2_getpeername(struct ast_sockaddr addr, char *host, int len)
{
    struct iax2_peer *peer = NULL;
    int res = 0;
    struct ao2_iterator i;
 
    i = ao2_iterator_init(peers, 0);
    while ((peer = ao2_iterator_next(&i))) {
 
        if (!ast_sockaddr_cmp(&peer->addr, &addr)) {
            ast_copy_string(host, peer->name, len);
            peer_unref(peer);
            res = 1;
            break;
        }
        peer_unref(peer);
    }
    ao2_iterator_destroy(&i);
 
    if (!peer) {
        peer = realtime_peer(NULL, &addr);
        if (peer) {
            ast_copy_string(host, peer->name, len);
            peer_unref(peer);
            res = 1;
        }
    }
 
    return res;
}
 
/* Call AST_SCHED_DEL on a scheduled task if it is found in scheduler. */
static int iax2_delete_from_sched(const void* data)
{
    int sched_id = (int)(long)data;
 
    AST_SCHED_DEL(sched, sched_id);
 
    return 0;
}
 
/*!\note Assumes the lock on the pvt is already held, when
 * iax2_destroy_helper() is called. */
static void iax2_destroy_helper(struct chan_iax2_pvt *pvt)
{
    /* Decrement AUTHREQ count if needed */
    if (ast_test_flag64(pvt, IAX_MAXAUTHREQ)) {
        struct iax2_user *user;
 
        user = ao2_find(users, pvt->username, OBJ_KEY);
        if (user) {
            ast_atomic_fetchadd_int(&user->curauthreq, -1);
            user_unref(user);
        }
 
        ast_clear_flag64(pvt, IAX_MAXAUTHREQ);
    }
 
 
    /* Mark call destroy initiated flag. */
    pvt->destroy_initiated = 1;
 
    /*
     * Schedule deleting the scheduled (but didn't run yet) PINGs or LAGRQs.
     * Already running tasks will be terminated because of destroy_initiated.
     *
     * Don't call AST_SCHED_DEL from this thread for pingid and lagid because
     * it leads to a deadlock between the scheduler thread callback locking
     * the callno mutex and this thread which holds the callno mutex one or
     * more times.  It is better to have another thread delete the scheduled
     * callbacks which doesn't lock the callno mutex.
     */
    iax2_sched_add(sched, 0, iax2_delete_from_sched, (void*)(long)pvt->pingid);
    iax2_sched_add(sched, 0, iax2_delete_from_sched, (void*)(long)pvt->lagid);
 
    pvt->pingid = -1;
    pvt->lagid = -1;
 
    AST_SCHED_DEL(sched, pvt->autoid);
    AST_SCHED_DEL(sched, pvt->authid);
    AST_SCHED_DEL(sched, pvt->initid);
    AST_SCHED_DEL(sched, pvt->jbid);
    AST_SCHED_DEL(sched, pvt->keyrotateid);
}
 
static void iax2_frame_free(struct iax_frame *fr)
{
    AST_SCHED_DEL(sched, fr->retrans);
    iax_frame_free(fr);
}
 
static int scheduled_destroy(const void *vid)
{
    unsigned short callno = PTR_TO_CALLNO(vid);
    ast_mutex_lock(&iaxsl[callno]);
    if (iaxs[callno]) {
        ast_debug(1, "Really destroying %d now...\n", callno);
        iax2_destroy(callno);
    }
    ast_mutex_unlock(&iaxsl[callno]);
    return 0;
}
 
static void free_signaling_queue_entry(struct signaling_queue_entry *s)
{
    if (s->f.datalen) {
        ast_free(s->f.data.ptr);
    }
    ast_free(s);
}
 
/*! \brief This function must be called once we are sure the other side has
 *  given us a call number.  All signaling is held here until that point. */
static void send_signaling(struct chan_iax2_pvt *pvt)
{
    struct signaling_queue_entry *s = NULL;
 
    while ((s = AST_LIST_REMOVE_HEAD(&pvt->signaling_queue, next))) {
        iax2_send(pvt, &s->f, 0, -1, 0, 0, 0);
        free_signaling_queue_entry(s);
    }
    pvt->hold_signaling = 0;
}
 
/*! \brief All frames other than that of type AST_FRAME_IAX must be held until
 *  we have received a destination call number. */
static int queue_signalling(struct chan_iax2_pvt *pvt, struct ast_frame *f)
{
    struct signaling_queue_entry *qe;
 
    if (f->frametype == AST_FRAME_IAX || !pvt->hold_signaling) {
        return 1; /* do not queue this frame */
    } else if (!(qe = ast_calloc(1, sizeof(struct signaling_queue_entry)))) {
        return -1;  /* out of memory */
    }
 
    /* copy ast_frame into our queue entry */
    qe->f = *f;
    if (qe->f.datalen) {
        /* if there is data in this frame copy it over as well */
        if (!(qe->f.data.ptr = ast_malloc(qe->f.datalen))) {
            free_signaling_queue_entry(qe);
            return -1;
        }
        memcpy(qe->f.data.ptr, f->data.ptr, qe->f.datalen);
    }
    AST_LIST_INSERT_TAIL(&pvt->signaling_queue, qe, next);
 
    return 0;
}
 
static void pvt_destructor(void *obj)
{
    struct chan_iax2_pvt *pvt = obj;
    struct iax_frame *cur = NULL;
    struct signaling_queue_entry *s = NULL;
 
    ast_mutex_lock(&iaxsl[pvt->callno]);
 
    iax2_destroy_helper(pvt);
 
    sched_delay_remove(&pvt->addr, pvt->callno_entry);
    pvt->callno_entry = 0;
 
    /* Already gone */
    ast_set_flag64(pvt, IAX_ALREADYGONE);
 
    AST_LIST_TRAVERSE(&frame_queue[pvt->callno], cur, list) {
        /* Cancel any pending transmissions */
        cur->retries = -1;
    }
 
    ast_mutex_unlock(&iaxsl[pvt->callno]);
 
    while ((s = AST_LIST_REMOVE_HEAD(&pvt->signaling_queue, next))) {
        free_signaling_queue_entry(s);
    }
 
    if (pvt->reg) {
        pvt->reg->callno = 0;
    }
 
    if (!pvt->owner) {
        jb_frame frame;
        if (pvt->vars) {
            ast_variables_destroy(pvt->vars);
            pvt->vars = NULL;
        }
 
        while (jb_getall(pvt->jb, &frame) == JB_OK) {
            iax2_frame_free(frame.data);
        }
 
        jb_destroy(pvt->jb);
        ast_string_field_free_memory(pvt);
    }
}
 
static struct chan_iax2_pvt *new_iax(struct ast_sockaddr *addr, const char *host)
{
    struct chan_iax2_pvt *tmp;
    jb_conf jbconf;
 
    if (!(tmp = ao2_alloc(sizeof(*tmp), pvt_destructor))) {
        return NULL;
    }
 
    tmp->pingid = -1;
    tmp->lagid = -1;
    tmp->autoid = -1;
    tmp->authid = -1;
    tmp->initid = -1;
    tmp->keyrotateid = -1;
    tmp->jbid = -1;
 
    if (ast_string_field_init(tmp, 32)) {
        ao2_ref(tmp, -1);
        tmp = NULL;
        return NULL;
    }
 
    tmp->prefs = prefs_global;
 
    ast_string_field_set(tmp,exten, "s");
    ast_string_field_set(tmp,host, host);
 
    tmp->jb = jb_new();
    jbconf.max_jitterbuf = maxjitterbuffer;
    jbconf.resync_threshold = resyncthreshold;
    jbconf.max_contig_interp = maxjitterinterps;
    jbconf.target_extra = jittertargetextra;
    jb_setconf(tmp->jb,&jbconf);
 
    AST_LIST_HEAD_INIT_NOLOCK(&tmp->dpentries);
 
    tmp->hold_signaling = 1;
    AST_LIST_HEAD_INIT_NOLOCK(&tmp->signaling_queue);
 
    return tmp;
}
 
static struct iax_frame *iaxfrdup2(struct iax_frame *fr)
{
    struct iax_frame *new = iax_frame_new(DIRECTION_INGRESS, fr->af.datalen, fr->cacheable);
    if (new) {
        size_t afdatalen = new->afdatalen;
        memcpy(new, fr, sizeof(*new));
        iax_frame_wrap(new, &fr->af);
        new->afdatalen = afdatalen;
        new->data = NULL;
        new->datalen = 0;
        new->direction = DIRECTION_INGRESS;
        new->retrans = -1;
    }
    return new;
}
/* keep these defined in this order.  They are used in find_callno to
 * determine whether or not a new call number should be allowed. */
enum {
    /* do not allow a new call number, only search ones in use for match */
    NEW_PREVENT = 0,
    /* search for match first, then allow a new one to be allocated */
    NEW_ALLOW = 1,
    /* do not search for match, force a new call number */
    NEW_FORCE = 2,
    /* do not search for match, force a new call number.  Signifies call number
     * has been calltoken validated */
    NEW_ALLOW_CALLTOKEN_VALIDATED = 3,
};
 
static int match(struct ast_sockaddr *addr, unsigned short callno, unsigned short dcallno, const struct chan_iax2_pvt *cur, int check_dcallno)
{
    if (!ast_sockaddr_cmp(&cur->addr, addr)) {
        /* This is the main host */
        if ( (cur->peercallno == 0 || cur->peercallno == callno) &&
             (check_dcallno ? dcallno == cur->callno : 1) ) {
            /* That's us.  Be sure we keep track of the peer call number */
            return 1;
        }
    }
    if (!ast_sockaddr_cmp(&cur->transfer, addr) && cur->transferring) {
        /* We're transferring */
        if ((dcallno == cur->callno) || (cur->transferring == TRANSFER_MEDIAPASS && cur->transfercallno == callno))
            return 1;
    }
    return 0;
}
 
static int make_trunk(unsigned short callno, int locked)
{
    int x;
    int res= 0;
    callno_entry entry;
    if (iaxs[callno]->oseqno) {
        ast_log(LOG_WARNING, "Can't make trunk once a call has started!\n");
        return -1;
    }
    if (callno >= TRUNK_CALL_START) {
        ast_log(LOG_WARNING, "Call %d is already a trunk\n", callno);
        return -1;
    }
 
    if (get_unused_callno(
            CALLNO_TYPE_TRUNK,
            CALLNO_ENTRY_IS_VALIDATED(iaxs[callno]->callno_entry),
            &entry)) {
        ast_log(LOG_WARNING, "Unable to trunk call: Insufficient space\n");
        return -1;
    }
 
    x = CALLNO_ENTRY_GET_CALLNO(entry);
    ast_mutex_lock(&iaxsl[x]);
 
    /*!
     * \note We delete these before switching the slot, because if
     * they fire in the meantime, they will generate a warning.
     */
    AST_SCHED_DEL(sched, iaxs[callno]->pingid);
    AST_SCHED_DEL(sched, iaxs[callno]->lagid);
    iaxs[callno]->lagid = iaxs[callno]->pingid = -1;
    iaxs[x] = iaxs[callno];
    iaxs[x]->callno = x;
 
    /* since we copied over the pvt from a different callno, make sure the old entry is replaced
     * before assigning the new one */
    if (iaxs[x]->callno_entry) {
        iax2_sched_add(
            sched,
            MIN_REUSE_TIME * 1000,
            replace_callno,
            CALLNO_ENTRY_TO_PTR(iaxs[x]->callno_entry));
 
    }
    iaxs[x]->callno_entry = entry;
 
    iaxs[callno] = NULL;
    /* Update the two timers that should have been started */
    iaxs[x]->pingid = iax2_sched_add(sched,
        ping_time * 1000, send_ping, (void *)(long)x);
    iaxs[x]->lagid = iax2_sched_add(sched,
        lagrq_time * 1000, send_lagrq, (void *)(long)x);
 
    if (locked)
        ast_mutex_unlock(&iaxsl[callno]);
    res = x;
    if (!locked)
        ast_mutex_unlock(&iaxsl[x]);
 
    /* We moved this call from a non-trunked to a trunked call */
    ast_debug(1, "Made call %d into trunk call %d\n", callno, x);
 
    return res;
}
 
static void store_by_transfercallno(struct chan_iax2_pvt *pvt)
{
    if (!pvt->transfercallno) {
        ast_log(LOG_ERROR, "This should not be called without a transfer call number.\n");
        return;
    }
 
    ao2_link(iax_transfercallno_pvts, pvt);
}
 
static void remove_by_transfercallno(struct chan_iax2_pvt *pvt)
{
    if (!pvt->transfercallno) {
        ast_log(LOG_ERROR, "This should not be called without a transfer call number.\n");
        return;
    }
 
    ao2_unlink(iax_transfercallno_pvts, pvt);
}
static void store_by_peercallno(struct chan_iax2_pvt *pvt)
{
    if (!pvt->peercallno) {
        ast_log(LOG_ERROR, "This should not be called without a peer call number.\n");
        return;
    }
 
    ao2_link(iax_peercallno_pvts, pvt);
}
 
static void remove_by_peercallno(struct chan_iax2_pvt *pvt)
{
    if (!pvt->peercallno) {
        ast_log(LOG_ERROR, "This should not be called without a peer call number.\n");
        return;
    }
 
    ao2_unlink(iax_peercallno_pvts, pvt);
}
 
static int addr_range_delme_cb(void *obj, void *arg, int flags)
{
    struct addr_range *lim = obj;
    lim->delme = 1;
    return 0;
}
 
static int addr_range_hash_cb(const void *obj, const int flags)
{
    const struct addr_range *lim = obj;
    return abs(ast_sockaddr_hash(&lim->ha.addr));
}
 
static int addr_range_cmp_cb(void *obj, void *arg, int flags)
{
    struct addr_range *lim1 = obj, *lim2 = arg;
    return (!(ast_sockaddr_cmp_addr(&lim1->ha.addr, &lim2->ha.addr)) &&
            !(ast_sockaddr_cmp_addr(&lim1->ha.netmask, &lim2->ha.netmask))) ?
            CMP_MATCH | CMP_STOP : 0;
}
 
static int peercnt_hash_cb(const void *obj, const int flags)
{
    const struct peercnt *peercnt = obj;
 
    if (ast_sockaddr_isnull(&peercnt->addr)) {
        return 0;
    }
    return ast_sockaddr_hash(&peercnt->addr);
}
 
static int peercnt_cmp_cb(void *obj, void *arg, int flags)
{
    struct peercnt *peercnt1 = obj, *peercnt2 = arg;
    return !ast_sockaddr_cmp_addr(&peercnt1->addr, &peercnt2->addr) ? CMP_MATCH | CMP_STOP : 0;
}
 
static int addr_range_match_address_cb(void *obj, void *arg, int flags)
{
    struct addr_range *addr_range = obj;
    struct ast_sockaddr *addr = arg;
    struct ast_sockaddr tmp_addr;
 
    ast_sockaddr_apply_netmask(addr, &addr_range->ha.netmask, &tmp_addr);
 
    if (!ast_sockaddr_cmp_addr(&tmp_addr, &addr_range->ha.addr)) {
        return CMP_MATCH | CMP_STOP;
    }
    return 0;
}
 
/*!
 * \internal
 *
 * \brief compares addr to calltoken_ignores table to determine if validation is required.
 */
static int calltoken_required(struct ast_sockaddr *addr, const char *name, int subclass)
{
    struct addr_range *addr_range;
    struct iax2_peer *peer = NULL;
    struct iax2_user *user = NULL;
    /* if no username is given, check for guest accounts */
    const char *find = S_OR(name, "guest");
    int res = 1;  /* required by default */
    int optional = 0;
    enum calltoken_peer_enum calltoken_required = CALLTOKEN_DEFAULT;
    /* There are only two cases in which calltoken validation is not required.
     * Case 1. sin falls within the list of address ranges specified in the calltoken optional table and
     *         the peer definition has not set the requirecalltoken option.
     * Case 2. Username is a valid peer/user, and that peer has requirecalltoken set either auto or no.
     */
 
    /* ----- Case 1 ----- */
    if ((addr_range = ao2_callback(calltoken_ignores, 0, addr_range_match_address_cb, addr))) {
        ao2_ref(addr_range, -1);
        optional = 1;
    }
 
    /* ----- Case 2 ----- */
    if ((subclass == IAX_COMMAND_NEW) && (user = find_user(find))) {
        calltoken_required = user->calltoken_required;
    } else if ((subclass == IAX_COMMAND_NEW) && (user = realtime_user(find, addr))) {
        calltoken_required = user->calltoken_required;
    } else if ((subclass != IAX_COMMAND_NEW) && (peer = find_peer(find, 0))) {
        calltoken_required = peer->calltoken_required;
    } else if ((subclass != IAX_COMMAND_NEW) && (peer = realtime_peer(find, addr))) {
        calltoken_required = peer->calltoken_required;
    }
 
    if (peer) {
        peer_unref(peer);
    }
    if (user) {
        user_unref(user);
    }
 
    ast_debug(1, "Determining if address %s with username %s requires calltoken validation.  Optional = %d  calltoken_required = %u \n", ast_sockaddr_stringify_addr(addr), name, optional, calltoken_required);
    if (((calltoken_required == CALLTOKEN_NO) || (calltoken_required == CALLTOKEN_AUTO)) ||
        (optional && (calltoken_required == CALLTOKEN_DEFAULT))) {
        res = 0;
    }
 
    return res;
}
 
/*!
 * \internal
 *
 * \brief set peercnt callno limit.
 *
 * \details
 * First looks in custom definitions. If not found, global limit
 * is used.  Entries marked as reg already have
 * a custom limit set by a registration and are not modified.
 */
static void set_peercnt_limit(struct peercnt *peercnt)
{
    uint16_t limit = global_maxcallno;
    struct addr_range *addr_range;
    struct ast_sockaddr addr;
 
    ast_sockaddr_copy(&addr, &peercnt->addr);
 
    if (peercnt->reg && peercnt->limit) {
        return; /* this peercnt has a custom limit set by a registration */
    }
 
    if ((addr_range = ao2_callback(callno_limits, 0, addr_range_match_address_cb, &addr))) {
        limit = addr_range->limit;
        ast_debug(1, "custom addr_range %d found for %s\n", limit, ast_sockaddr_stringify(&addr));
        ao2_ref(addr_range, -1);
    }
 
    peercnt->limit = limit;
}
 
/*!
 * \internal
 * \brief sets limits for all peercnts in table. done on reload to reflect changes in conf.
 */
static int set_peercnt_limit_all_cb(void *obj, void *arg, int flags)
{
    struct peercnt *peercnt = obj;
 
    set_peercnt_limit(peercnt);
    ast_debug(1, "Reset limits for peercnts table\n");
 
    return 0;
}
 
/*!
 * \internal
 * \brief returns match if delme is set.
 */
static int prune_addr_range_cb(void *obj, void *arg, int flags)
{
    struct addr_range *addr_range = obj;
 
    return addr_range->delme ? CMP_MATCH : 0;
}
 
/*!
 * \internal
 * \brief modifies peercnt entry in peercnts table. Used to set custom limit or mark a registered ip
 */
static void peercnt_modify(unsigned char reg, uint16_t limit, struct ast_sockaddr *sockaddr)
{
    /* this function turns off and on custom callno limits set by peer registration */
    struct peercnt *peercnt;
    struct peercnt tmp;
 
    ast_sockaddr_copy(&tmp.addr, sockaddr);
 
    if ((peercnt = ao2_find(peercnts, &tmp, OBJ_POINTER))) {
        peercnt->reg = reg;
        if (limit) {
            peercnt->limit = limit;
        } else {
            set_peercnt_limit(peercnt);
        }
        ast_debug(1, "peercnt entry %s modified limit:%d registered:%d", ast_sockaddr_stringify_addr(sockaddr), peercnt->limit, peercnt->reg);
        ao2_ref(peercnt, -1); /* decrement ref from find */
    }
}
 
/*!
 * \internal
 * \brief adds an ip to the peercnts table, increments connection count if it already exists
 *
 * \details First searches for the address in the peercnts table.  If found
 * the current count is incremented.  If not found a new peercnt is allocated
 * and linked into the peercnts table with a call number count of 1.
 */
static int peercnt_add(struct ast_sockaddr *addr)
{
    struct peercnt *peercnt;
    int res = 0;
    struct peercnt tmp;
 
    ast_sockaddr_copy(&tmp.addr, addr);
 
    /* Reasoning for peercnts container lock:  Two identical ip addresses
     * could be added by different threads at the "same time". Without the container
     * lock, both threads could alloc space for the same object and attempt
     * to link to table.  With the lock, one would create the object and link
     * to table while the other would find the already created peercnt object
     * rather than creating a new one. */
    ao2_lock(peercnts);
    if ((peercnt = ao2_find(peercnts, &tmp, OBJ_POINTER))) {
        ao2_lock(peercnt);
    } else if ((peercnt = ao2_alloc(sizeof(*peercnt), NULL))) {
        ao2_lock(peercnt);
        /* create and set defaults */
        ast_sockaddr_copy(&peercnt->addr, addr);
        set_peercnt_limit(peercnt);
        /* guarantees it does not go away after unlocking table
         * ao2_find automatically adds this */
        ao2_link(peercnts, peercnt);
    } else {
        ao2_unlock(peercnts);
        return -1;
    }
 
    /* check to see if the address has hit its callno limit.  If not increment cur. */
    if (peercnt->limit > peercnt->cur) {
        peercnt->cur++;
        ast_debug(1, "ip callno count incremented to %d for %s\n", peercnt->cur, ast_sockaddr_stringify_addr(addr));
    } else { /* max num call numbers for this peer has been reached! */
        ast_log(LOG_ERROR, "maxcallnumber limit of %d for %s has been reached!\n", peercnt->limit, ast_sockaddr_stringify_addr(addr));
        res = -1;
    }
 
    /* clean up locks and ref count */
    ao2_unlock(peercnt);
    ao2_unlock(peercnts);
    ao2_ref(peercnt, -1); /* decrement ref from find/alloc, only the container ref remains. */
 
    return res;
}
 
/*!
 * \internal
 * \brief decrements a peercnts table entry
 */
static void peercnt_remove(struct peercnt *peercnt)
{
    struct ast_sockaddr addr;
 
    ast_sockaddr_copy(&addr, &peercnt->addr);
 
    /*
     * Container locked here since peercnt may be unlinked from
     * list.  If left unlocked, peercnt_add could try and grab this
     * entry from the table and modify it at the "same time" this
     * thread attempts to unlink it.
     */
    ao2_lock(peercnts);
    peercnt->cur--;
    ast_debug(1, "ip callno count decremented to %d for %s\n", peercnt->cur, ast_sockaddr_stringify_addr(&addr));
    /* if this was the last connection from the peer remove it from table */
    if (peercnt->cur == 0) {
        ao2_unlink(peercnts, peercnt);/* decrements ref from table, last ref is left to scheduler */
    }
    ao2_unlock(peercnts);
}
 
/*!
 * \internal
 * \brief called by scheduler to decrement object
 */
static int peercnt_remove_cb(const void *obj)
{
    struct peercnt *peercnt = (struct peercnt *) obj;
 
    peercnt_remove(peercnt);
    ao2_ref(peercnt, -1); /* decrement ref from scheduler */
 
    return 0;
}
 
/*!
 * \internal
 * \brief decrements peercnts connection count, finds by addr
 */
static int peercnt_remove_by_addr(struct ast_sockaddr *addr)
{
    struct peercnt *peercnt;
    struct peercnt tmp;
 
    ast_sockaddr_copy(&tmp.addr, addr);
 
    if ((peercnt = ao2_find(peercnts, &tmp, OBJ_POINTER))) {
        peercnt_remove(peercnt);
        ao2_ref(peercnt, -1); /* decrement ref from find */
    }
    return 0;
}
 
/*!
 * \internal
 * \brief Create callno_limit entry based on configuration
 */
static void build_callno_limits(struct ast_variable *v)
{
    struct addr_range *addr_range = NULL;
    struct addr_range tmp;
    struct ast_ha *ha;
    int limit;
    int error;
    int found;
 
    for (; v; v = v->next) {
        limit = -1;
        error = 0;
        found = 0;
        ha = ast_append_ha("permit", v->name, NULL, &error);
 
        /* check for valid config information */
        if (error) {
            ast_log(LOG_ERROR, "Call number limit for %s could not be added, Invalid address range\n.", v->name);
            continue;
        } else if ((sscanf(v->value, "%d", &limit) != 1) || (limit < 0)) {
            ast_log(LOG_ERROR, "Call number limit for %s could not be added. Invalid limit %s\n.", v->name, v->value);
            ast_free_ha(ha);
            continue;
        }
 
        ast_copy_ha(ha, &tmp.ha);
        /* find or create the addr_range */
        if ((addr_range = ao2_find(callno_limits, &tmp, OBJ_POINTER))) {
            ao2_lock(addr_range);
            found = 1;
        } else if (!(addr_range = ao2_alloc(sizeof(*addr_range), NULL))) {
            ast_free_ha(ha);
            return; /* out of memory */
        }
 
        /* copy over config data into addr_range object */
        ast_copy_ha(ha, &addr_range->ha); /* this is safe because only one ha is possible for each limit */
        ast_free_ha(ha); /* cleanup the tmp ha */
        addr_range->limit = limit;
        addr_range->delme = 0;
 
        /* cleanup */
        if (found) {
            ao2_unlock(addr_range);
        } else {
            ao2_link(callno_limits, addr_range);
        }
        ao2_ref(addr_range, -1); /* decrement ref from ao2_find and ao2_alloc, only container ref remains */
    }
}
 
/*!
 * \internal
 * \brief Create calltoken_ignores entry based on configuration
 */
static int add_calltoken_ignore(const char *addr)
{
    struct addr_range tmp;
    struct addr_range *addr_range = NULL;
    struct ast_ha *ha = NULL;
    int error = 0;
 
    if (ast_strlen_zero(addr)) {
        ast_log(LOG_WARNING, "invalid calltokenoptional (null)\n");
        return -1;
    }
 
    ha = ast_append_ha("permit", addr, NULL, &error);
 
    /* check for valid config information */
    if (error) {
        ast_log(LOG_WARNING, "Error %d creating calltokenoptional entry %s\n", error, addr);
        return -1;
    }
 
    ast_copy_ha(ha, &tmp.ha);
    /* find or create the addr_range */
    if ((addr_range = ao2_find(calltoken_ignores, &tmp, OBJ_POINTER))) {
        ao2_lock(addr_range);
        addr_range->delme = 0;
        ao2_unlock(addr_range);
    } else if ((addr_range = ao2_alloc(sizeof(*addr_range), NULL))) {
        /* copy over config data into addr_range object */
        ast_copy_ha(ha, &addr_range->ha); /* this is safe because only one ha is possible */
        ao2_link(calltoken_ignores, addr_range);
    } else {
        ast_free_ha(ha);
        return -1;
    }
 
    ast_free_ha(ha);
    ao2_ref(addr_range, -1); /* decrement ref from ao2_find and ao2_alloc, only container ref remains */
 
    return 0;
}
 
static char *handle_cli_iax2_show_callno_limits(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
    struct ao2_iterator i;
    struct peercnt *peercnt;
    struct ast_sockaddr addr;
    int found = 0;
 
    switch (cmd) {
    case CLI_INIT:
        e->command = "iax2 show callnumber usage";
        e->usage =
            "Usage: iax2 show callnumber usage [IP address]\n"
            "       Shows current IP addresses which are consuming iax2 call numbers\n";
        return NULL;
    case CLI_GENERATE:
        return NULL;
    case CLI_HANDLER:
        if (a->argc < 4 || a->argc > 5)
            return CLI_SHOWUSAGE;
 
        if (a->argc == 4) {
            ast_cli(a->fd, "%-45s %-12s %-12s\n", "Address", "Callno Usage", "Callno Limit");
        }
 
        i = ao2_iterator_init(peercnts, 0);
        while ((peercnt = ao2_iterator_next(&i))) {
            ast_sockaddr_copy(&addr, &peercnt->addr);
 
            if (a->argc == 5) {
                if (!strcasecmp(a->argv[4], ast_sockaddr_stringify(&addr))) {
                    ast_cli(a->fd, "%-45s %-12s %-12s\n", "Address", "Callno Usage", "Callno Limit");
                    ast_cli(a->fd, "%-45s %-12d %-12d\n", ast_sockaddr_stringify(&addr), peercnt->cur, peercnt->limit);
                    ao2_ref(peercnt, -1);
                    found = 1;
                    break;
                }
            } else {
                ast_cli(a->fd, "%-45s %-12d %-12d\n", ast_sockaddr_stringify(&addr), peercnt->cur, peercnt->limit);
            }
            ao2_ref(peercnt, -1);
        }
        ao2_iterator_destroy(&i);
 
        if (a->argc == 4) {
            size_t pool_avail = callno_pool.available;
            size_t trunk_pool_avail = callno_pool_trunk.available;
 
            ast_cli(a->fd, "\nNon-CallToken Validation Callno Limit: %d\n"
                             "Non-CallToken Validated Callno Used:   %d\n",
                global_maxcallno_nonval,
                total_nonval_callno_used);
 
            ast_cli(a->fd,   "Total Available Callno:                %zu\n"
                             "Regular Callno Available:              %zu\n"
                             "Trunk Callno Available:                %zu\n",
                pool_avail + trunk_pool_avail,
                pool_avail,
                trunk_pool_avail);
        } else if (a->argc == 5 && !found) {
            ast_cli(a->fd, "No call number table entries for %s found\n", a->argv[4] );
        }
 
 
        return CLI_SUCCESS;
    default:
        return NULL;
    }
}
 
static int get_unused_callno(enum callno_type type, int validated, callno_entry *entry)
{
    struct call_number_pool *pool = NULL;
    callno_entry swap;
    size_t choice;
 
    switch (type) {
    case CALLNO_TYPE_NORMAL:
        pool = &callno_pool;
        break;
    case CALLNO_TYPE_TRUNK:
        pool = &callno_pool_trunk;
        break;
    default:
        ast_assert(0);
        break;
    }
 
    /* If we fail, make sure this has a defined value */
    *entry = 0;
 
    /* We lock here primarily to ensure thread safety of the
     * total_nonval_callno_used check and increment */
    ast_mutex_lock(&callno_pool_lock);
 
    /* Bail out if we don't have any available call numbers */
    if (!pool->available) {
        ast_log(LOG_WARNING, "Out of call numbers\n");
        ast_mutex_unlock(&callno_pool_lock);
        return 1;
    }
 
    /* Only a certain number of non-validated call numbers should be allocated.
     * If there ever is an attack, this separates the calltoken validating users
     * from the non-calltoken validating users. */
    if (!validated && total_nonval_callno_used >= global_maxcallno_nonval) {
        ast_log(LOG_WARNING,
            "NON-CallToken callnumber limit is reached. Current: %d Max: %d\n",
            total_nonval_callno_used,
            global_maxcallno_nonval);
        ast_mutex_unlock(&callno_pool_lock);
        return 1;
    }
 
    /* We use a modified Fisher-Yates-Durstenfeld Shuffle to maintain a list of
     * available call numbers.  The array of call numbers begins as an ordered
     * list from 1 -> n, and we keep a running tally of how many remain unclaimed
     * - let's call that x.  When a call number is needed we pick a random index
     * into the array between 0 and x and use that as our call number.  In a
     * typical FYD shuffle, we would swap the value that we are extracting with
     * the number at x, but in our case we swap and don't touch the value at x
     * because it is effectively invisible.  We rely on the rest of the IAX2 core
     * to return the number to us at some point.  Finally, we decrement x by 1
     * which establishes our new unused range.
     *
     * When numbers are returned to the pool, we put them just past x and bump x
     * by 1 so that this number is now available for re-use. */
 
    choice = ast_random() % pool->available;
 
    *entry = pool->numbers[choice];
    swap = pool->numbers[pool->available - 1];
 
    pool->numbers[choice] = swap;
    pool->available--;
 
    if (validated) {
        CALLNO_ENTRY_SET_VALIDATED(*entry);
    } else {
        total_nonval_callno_used++;
    }
 
    ast_mutex_unlock(&callno_pool_lock);
 
    return 0;
}
 
static int replace_callno(const void *obj)
{
    callno_entry entry = PTR_TO_CALLNO_ENTRY(obj);
    struct call_number_pool *pool;
 
    /* We lock here primarily to ensure thread safety of the
     * total_nonval_callno_used check and decrement */
    ast_mutex_lock(&callno_pool_lock);
 
    if (!CALLNO_ENTRY_IS_VALIDATED(entry)) {
        if (total_nonval_callno_used) {
            total_nonval_callno_used--;
        } else {
            ast_log(LOG_ERROR,
                "Attempted to decrement total non calltoken validated "
                "callnumbers below zero.  Callno is: %d\n",
                CALLNO_ENTRY_GET_CALLNO(entry));
        }
    }
 
    if (CALLNO_ENTRY_GET_CALLNO(entry) < TRUNK_CALL_START) {
        pool = &callno_pool;
    } else {
        pool = &callno_pool_trunk;
    }
 
    ast_assert(pool->capacity > pool->available);
 
    /* This clears the validated flag */
    entry = CALLNO_ENTRY_GET_CALLNO(entry);
 
    pool->numbers[pool->available] = entry;
    pool->available++;
 
    ast_mutex_unlock(&callno_pool_lock);
 
    return 0;
}
 
static int create_callno_pools(void)
{
    uint16_t i;
 
    callno_pool.available = callno_pool_trunk.available = 0;
 
    /* We start at 2.  0 and 1 are reserved. */
    for (i = 2; i < TRUNK_CALL_START; i++) {
        callno_pool.numbers[callno_pool.available] = i;
        callno_pool.available++;
    }
 
    for (i = TRUNK_CALL_START; i < IAX_MAX_CALLS; i++) {
        callno_pool_trunk.numbers[callno_pool_trunk.available] = i;
        callno_pool_trunk.available++;
    }
 
    callno_pool.capacity = callno_pool.available;
    callno_pool_trunk.capacity = callno_pool_trunk.available;
 
    ast_assert(callno_pool.capacity && callno_pool_trunk.capacity);
 
    return 0;
}
 
/*!
 * \internal
 * \brief Schedules delayed removal of iax2_pvt call number data
 *
 * \note After MIN_REUSE_TIME has passed for a destroyed iax2_pvt, the callno is
 * available again, and the address from the previous connection must be decremented
 * from the peercnts table.  This function schedules these operations to take place.
 */
static void sched_delay_remove(struct ast_sockaddr *addr, callno_entry entry)
{
    int i;
    struct peercnt *peercnt;
    struct peercnt tmp;
 
    ast_sockaddr_copy(&tmp.addr, addr);
 
    if ((peercnt = ao2_find(peercnts, &tmp, OBJ_POINTER))) {
        /* refcount is incremented with ao2_find.  keep that ref for the scheduler */
        ast_debug(1, "schedule decrement of callno used for %s in %d seconds\n", ast_sockaddr_stringify_addr(addr), MIN_REUSE_TIME);
        i = iax2_sched_add(sched, MIN_REUSE_TIME * 1000, peercnt_remove_cb, peercnt);
        if (i == -1) {
            ao2_ref(peercnt, -1);
        }
    }
 
    iax2_sched_add(
        sched,
        MIN_REUSE_TIME * 1000,
        replace_callno,
        CALLNO_ENTRY_TO_PTR(entry));
}
 
/*!
 * \internal
 * \brief returns whether or not a frame is capable of starting a new IAX2 dialog.
 *
 * \note For this implementation, inbound pokes should _NOT_ be capable of allocating
 * a new callno.
 */
static inline int attribute_pure iax2_allow_new(int frametype, int subclass, int inbound)
{
    if (frametype != AST_FRAME_IAX) {
        return 0;
    }
    switch (subclass) {
    case IAX_COMMAND_NEW:
    case IAX_COMMAND_REGREQ:
    case IAX_COMMAND_FWDOWNL:
    case IAX_COMMAND_REGREL:
        return 1;
    case IAX_COMMAND_POKE:
        if (!inbound) {
            return 1;
        }
        break;
    }
    return 0;
}
 
/*!
 * \note Calling this function while holding another pvt lock can cause a deadlock.
 */
static int __find_callno(unsigned short callno, unsigned short dcallno, struct ast_sockaddr *addr, int new, int sockfd, int return_locked, int check_dcallno)
{
    int res = 0;
    int x;
    /* this call is calltoken validated as long as it is either NEW_FORCE
     * or NEW_ALLOW_CALLTOKEN_VALIDATED */
    int validated = (new > NEW_ALLOW) ? 1 : 0;
    char host[80];
 
    if (new <= NEW_ALLOW) {
        if (callno) {
            struct chan_iax2_pvt *pvt;
            struct chan_iax2_pvt tmp_pvt = {
                .callno = dcallno,
                .peercallno = callno,
                .transfercallno = callno,
                /* hack!! */
                .frames_received = check_dcallno,
            };
 
            ast_sockaddr_copy(&tmp_pvt.addr, addr);
            /* this works for finding normal call numbers not involving transfering */
            if ((pvt = ao2_find(iax_peercallno_pvts, &tmp_pvt, OBJ_POINTER))) {
                if (return_locked) {
                    ast_mutex_lock(&iaxsl[pvt->callno]);
                }
                res = pvt->callno;
                ao2_ref(pvt, -1);
                pvt = NULL;
                return res;
            }
            /* this searches for transfer call numbers that might not get caught otherwise */
            memset(&tmp_pvt.addr, 0, sizeof(tmp_pvt.addr));
            ast_sockaddr_copy(&tmp_pvt.transfer, addr);
            if ((pvt = ao2_find(iax_transfercallno_pvts, &tmp_pvt, OBJ_POINTER))) {
                if (return_locked) {
                    ast_mutex_lock(&iaxsl[pvt->callno]);
                }
                res = pvt->callno;
                ao2_ref(pvt, -1);
                pvt = NULL;
                return res;
            }
        }
            /* This will occur on the first response to a message that we initiated,
         * such as a PING. */
        if (dcallno) {
            ast_mutex_lock(&iaxsl[dcallno]);
        }
        if (callno && dcallno && iaxs[dcallno] && !iaxs[dcallno]->peercallno && match(addr, callno, dcallno, iaxs[dcallno], check_dcallno)) {
            iaxs[dcallno]->peercallno = callno;
            res = dcallno;
            store_by_peercallno(iaxs[dcallno]);
            if (!res || !return_locked) {
                ast_mutex_unlock(&iaxsl[dcallno]);
            }
            return res;
        }
        if (dcallno) {
            ast_mutex_unlock(&iaxsl[dcallno]);
        }
    }
    if (!res && (new >= NEW_ALLOW)) {
        callno_entry entry;
 
        /* It may seem odd that we look through the peer list for a name for
         * this *incoming* call.  Well, it is weird.  However, users don't
         * have an IP address/port number that we can match against.  So,
         * this is just checking for a peer that has that IP/port and
         * assuming that we have a user of the same name.  This isn't always
         * correct, but it will be changed if needed after authentication. */
        if (!iax2_getpeername(*addr, host, sizeof(host)))
            snprintf(host, sizeof(host), "%s", ast_sockaddr_stringify(addr));
 
        if (peercnt_add(addr)) {
            /* This address has hit its callnumber limit.  When the limit
             * is reached, the connection is not added to the peercnts table.*/
            return 0;
        }
 
        if (get_unused_callno(CALLNO_TYPE_NORMAL, validated, &entry)) {
            /* since we ran out of space, remove the peercnt
             * entry we added earlier */
            peercnt_remove_by_addr(addr);
            ast_log(LOG_WARNING, "No more space\n");
            return 0;
        }
        x = CALLNO_ENTRY_GET_CALLNO(entry);
        ast_mutex_lock(&iaxsl[x]);
 
        iaxs[x] = new_iax(addr, host);
        if (iaxs[x]) {
            if (iaxdebug)
                ast_debug(1, "Creating new call structure %d\n", x);
            iaxs[x]->callno_entry = entry;
            iaxs[x]->sockfd = sockfd;
            ast_sockaddr_copy(&iaxs[x]->addr, addr);
            iaxs[x]->peercallno = callno;
            iaxs[x]->callno = x;
            iaxs[x]->pingtime = DEFAULT_RETRY_TIME;
            iaxs[x]->expiry = min_reg_expire;
            iaxs[x]->pingid = iax2_sched_add(sched, ping_time * 1000, send_ping, (void *)(long)x);
            iaxs[x]->lagid = iax2_sched_add(sched, lagrq_time * 1000, send_lagrq, (void *)(long)x);
            iaxs[x]->amaflags = amaflags;
            ast_copy_flags64(iaxs[x], &globalflags, IAX_NOTRANSFER | IAX_TRANSFERMEDIA | IAX_USEJITTERBUF | IAX_SENDCONNECTEDLINE | IAX_RECVCONNECTEDLINE | IAX_FORCE_ENCRYPT);
            ast_string_field_set(iaxs[x], accountcode, accountcode);
            ast_string_field_set(iaxs[x], mohinterpret, mohinterpret);
            ast_string_field_set(iaxs[x], mohsuggest, mohsuggest);
            ast_string_field_set(iaxs[x], parkinglot, default_parkinglot);
 
            if (iaxs[x]->peercallno) {
                store_by_peercallno(iaxs[x]);
            }
        } else {
            ast_log(LOG_WARNING, "Out of resources\n");
            ast_mutex_unlock(&iaxsl[x]);
            replace_callno(CALLNO_ENTRY_TO_PTR(entry));
            return 0;
        }
        if (!return_locked)
            ast_mutex_unlock(&iaxsl[x]);
        res = x;
    }
    return res;
}
 
static int find_callno(unsigned short callno, unsigned short dcallno, struct ast_sockaddr *addr, int new, int sockfd, int full_frame) {
    return __find_callno(callno, dcallno, addr, new, sockfd, 0, full_frame);
}
 
static int find_callno_locked(unsigned short callno, unsigned short dcallno, struct ast_sockaddr *addr, int new, int sockfd, int full_frame) {
 
    return __find_callno(callno, dcallno, addr, new, sockfd, 1, full_frame);
}
 
/*!
 * \brief Queue a frame to a call's owning asterisk channel
 *
 * \pre This function assumes that iaxsl[callno] is locked when called.
 *
 * \note IMPORTANT NOTE!!! Any time this function is used, even if iaxs[callno]
 * was valid before calling it, it may no longer be valid after calling it.
 * This function may unlock and lock the mutex associated with this callno,
 * meaning that another thread may grab it and destroy the call.
 */
static int iax2_queue_frame(int callno, struct ast_frame *f)
{
    iax2_lock_owner(callno);
    if (iaxs[callno] && iaxs[callno]->owner) {
        ast_queue_frame(iaxs[callno]->owner, f);
        ast_channel_unlock(iaxs[callno]->owner);
    }
    return 0;
}
 
/*!
 * \brief Queue a hold frame on the ast_channel owner
 *
 * This function queues a hold frame on the owner of the IAX2 pvt struct that
 * is active for the given call number.
 *
 * \pre Assumes lock for callno is already held.
 *
 * \note IMPORTANT NOTE!!! Any time this function is used, even if iaxs[callno]
 * was valid before calling it, it may no longer be valid after calling it.
 * This function may unlock and lock the mutex associated with this callno,
 * meaning that another thread may grab it and destroy the call.
 */
static int iax2_queue_hold(int callno, const char *musicclass)
{
    iax2_lock_owner(callno);
    if (iaxs[callno] && iaxs[callno]->owner) {
        ast_queue_hold(iaxs[callno]->owner, musicclass);
        ast_channel_unlock(iaxs[callno]->owner);
    }
    return 0;
}
 
/*!
 * \brief Queue an unhold frame on the ast_channel owner
 *
 * This function queues an unhold frame on the owner of the IAX2 pvt struct that
 * is active for the given call number.
 *
 * \pre Assumes lock for callno is already held.
 *
 * \note IMPORTANT NOTE!!! Any time this function is used, even if iaxs[callno]
 * was valid before calling it, it may no longer be valid after calling it.
 * This function may unlock and lock the mutex associated with this callno,
 * meaning that another thread may grab it and destroy the call.
 */
static int iax2_queue_unhold(int callno)
{
    iax2_lock_owner(callno);
    if (iaxs[callno] && iaxs[callno]->owner) {
        ast_queue_unhold(iaxs[callno]->owner);
        ast_channel_unlock(iaxs[callno]->owner);
    }
    return 0;
}
 
/*!
 * \brief Queue a hangup frame on the ast_channel owner
 *
 * This function queues a hangup frame on the owner of the IAX2 pvt struct that
 * is active for the given call number.
 *
 * \pre Assumes lock for callno is already held.
 *
 * \note IMPORTANT NOTE!!! Any time this function is used, even if iaxs[callno]
 * was valid before calling it, it may no longer be valid after calling it.
 * This function may unlock and lock the mutex associated with this callno,
 * meaning that another thread may grab it and destroy the call.
 */
static int iax2_queue_hangup(int callno)
{
    iax2_lock_owner(callno);
    if (iaxs[callno] && iaxs[callno]->owner) {
        ast_queue_hangup(iaxs[callno]->owner);
        ast_channel_unlock(iaxs[callno]->owner);
    }
    return 0;
}
 
/*!
 * \note This function assumes that iaxsl[callno] is locked when called.
 *
 * \note IMPORTANT NOTE!!! Any time this function is used, even if iaxs[callno]
 * was valid before calling it, it may no longer be valid after calling it.
 * This function calls iax2_queue_frame(), which may unlock and lock the mutex
 * associated with this callno, meaning that another thread may grab it and destroy the call.
 */
static int __do_deliver(void *data)
{
    /* Just deliver the packet by using queueing.  This is called by
      the IAX thread with the iaxsl lock held. */
    struct iax_frame *fr = data;
    fr->retrans = -1;
    ast_clear_flag(&fr->af, AST_FRFLAG_HAS_TIMING_INFO);
    if (iaxs[fr->callno] && !ast_test_flag64(iaxs[fr->callno], IAX_ALREADYGONE))
        iax2_queue_frame(fr->callno, &fr->af);
    /* Free our iax frame */
    iax2_frame_free(fr);
    /* And don't run again */
    return 0;
}
 
static int handle_error(void)
{
    /* XXX Ideally we should figure out why an error occurred and then abort those
       rather than continuing to try.  Unfortunately, the published interface does
       not seem to work XXX */
#if 0
    struct sockaddr_in *sin;
    int res;
    struct msghdr m;
    struct sock_extended_err e;
    m.msg_name = NULL;
    m.msg_namelen = 0;
    m.msg_iov = NULL;
    m.msg_control = &e;
    m.msg_controllen = sizeof(e);
    m.msg_flags = 0;
    res = recvmsg(netsocket, &m, MSG_ERRQUEUE);
    if (res < 0)
        ast_log(LOG_WARNING, "Error detected, but unable to read error: %s\n", strerror(errno));
    else {
        if (m.msg_controllen) {
            sin = (struct sockaddr_in *)SO_EE_OFFENDER(&e);
            if (sin)
                ast_log(LOG_WARNING, "Receive error from %s\n", ast_inet_ntoa(sin->sin_addr));
            else
                ast_log(LOG_WARNING, "No address detected??\n");
        } else {
            ast_log(LOG_WARNING, "Local error: %s\n", strerror(e.ee_errno));
        }
    }
#endif
    return 0;
}
 
static int transmit_trunk(struct iax_frame *f, struct ast_sockaddr *addr, int sockfd)
{
    int res;
    res = ast_sendto(sockfd, f->data, f->datalen, 0, addr);
 
    if (res < 0) {
        ast_debug(1, "Received error: %s\n", strerror(errno));
        handle_error();
    } else
        res = 0;
    return res;
}
 
static int send_packet(struct iax_frame *f)
{
    int res;
    int callno = f->callno;
 
    /* Don't send if there was an error, but return error instead */
    if (!callno || !iaxs[callno] || iaxs[callno]->error)
        return -1;
 
    /* Called with iaxsl held */
    if (iaxdebug) {
        ast_debug(8, "Sending %u on %d/%d to %s\n", f->ts, callno, iaxs[callno]->peercallno, ast_sockaddr_stringify(&iaxs[callno]->addr));
    }
    if (f->transfer) {
        iax_outputframe(f, NULL, 0, &iaxs[callno]->transfer, f->datalen - sizeof(struct ast_iax2_full_hdr));
        res = ast_sendto(iaxs[callno]->sockfd, f->data, f->datalen, 0, &iaxs[callno]->transfer);
    } else {
        iax_outputframe(f, NULL, 0, &iaxs[callno]->addr, f->datalen - sizeof(struct ast_iax2_full_hdr));
        res = ast_sendto(iaxs[callno]->sockfd, f->data, f->datalen, 0, &iaxs[callno]->addr);
    }
    if (res < 0) {
        if (iaxdebug)
            ast_debug(1, "Received error: %s\n", strerror(errno));
        handle_error();
    } else
        res = 0;
 
    return res;
}
 
/*!
 * \note Since this function calls iax2_queue_hangup(), the pvt struct
 *       for the given call number may disappear during its execution.
 */
static int iax2_predestroy(int callno)
{
    struct ast_channel *c = NULL;
    struct chan_iax2_pvt *pvt = iaxs[callno];
 
    if (!pvt)
        return -1;
 
    if (!ast_test_flag64(pvt, IAX_ALREADYGONE)) {
        iax2_destroy_helper(pvt);
        ast_set_flag64(pvt, IAX_ALREADYGONE);
    }
 
    if ((c = pvt->owner)) {
        ast_channel_tech_pvt_set(c, NULL);
        iax2_queue_hangup(callno);
        pvt->owner = NULL;
        ast_module_unref(ast_module_info->self);
    }
 
    return 0;
}
 
static void iax2_destroy(int callno)
{
    struct chan_iax2_pvt *pvt = NULL;
    struct ast_channel *owner = NULL;
 
retry:
    if ((pvt = iaxs[callno])) {
#if 0
        /* iax2_destroy_helper gets called from this function later on.  When
         * called twice, we get the (previously) familiar FRACK! errors in
         * devmode, from the scheduler.  An alternative to this approach is to
         * reset the scheduler entries to -1 when they're deleted in
         * iax2_destroy_helper().  That approach was previously decided to be
         * "wrong" because "the memory is going to be deallocated anyway.  Why
         * should we be resetting those values?" */
        iax2_destroy_helper(pvt);
#endif
    }
 
    owner = pvt ? pvt->owner : NULL;
 
    if (owner) {
        if (ast_channel_trylock(owner)) {
            ast_debug(3, "Avoiding IAX destroy deadlock\n");
            DEADLOCK_AVOIDANCE(&iaxsl[callno]);
            goto retry;
        }
    }
 
    if (!owner) {
        iaxs[callno] = NULL;
    }
 
    if (pvt) {
        if (!owner) {
            pvt->owner = NULL;
        } else {
            /* If there's an owner, prod it to give up */
            /* It is ok to use ast_queue_hangup() here instead of iax2_queue_hangup()
             * because we already hold the owner channel lock. */
            ast_queue_hangup(owner);
        }
 
        if (pvt->peercallno) {
            remove_by_peercallno(pvt);
        }
 
        if (pvt->transfercallno) {
            remove_by_transfercallno(pvt);
        }
 
        if (!owner) {
            ao2_ref(pvt, -1);
            pvt = NULL;
        }
    }
 
    if (owner) {
        ast_channel_unlock(owner);
    }
}
 
static int update_packet(struct iax_frame *f)
{
    /* Called with iaxsl lock held, and iaxs[callno] non-NULL */
    struct ast_iax2_full_hdr *fh = f->data;
    struct ast_frame af;
 
    /* if frame is encrypted. decrypt before updating it. */
    if (f->encmethods) {
        decode_frame(&f->mydcx, fh, &af, &f->datalen);
    }
    /* Mark this as a retransmission */
    fh->dcallno = ntohs(IAX_FLAG_RETRANS | f->dcallno);
    /* Update iseqno */
    f->iseqno = iaxs[f->callno]->iseqno;
    fh->iseqno = f->iseqno;
 
    /* Now re-encrypt the frame */
    if (f->encmethods) {
    /* since this is a retransmit frame, create a new random padding
     * before re-encrypting. */
        build_rand_pad(f->semirand, sizeof(f->semirand));
        encrypt_frame(&f->ecx, fh, f->semirand, &f->datalen);
    }
    return 0;
}
 
static int attempt_transmit(const void *data);
static void __attempt_transmit(const void *data)
{
    /* Attempt to transmit the frame to the remote peer...
       Called without iaxsl held. */
    struct iax_frame *f = (struct iax_frame *)data;
    int freeme = 0;
    int callno = f->callno;
 
    /* Make sure this call is still active */
    if (callno)
        ast_mutex_lock(&iaxsl[callno]);
    if (callno && iaxs[callno]) {
        if (f->retries < 0) {
            /* Already ACK'd */
            freeme = 1;
        } else if (f->retries >= max_retries) {
            /* Too many attempts.  Record an error. */
            if (f->transfer) {
                /* Transfer timeout */
                send_command(iaxs[callno], AST_FRAME_IAX, IAX_COMMAND_TXREJ, 0, NULL, 0, -1);
            } else if (f->final) {
                iax2_destroy(callno);
            } else {
                if (iaxs[callno]->owner) {
                    ast_log(LOG_WARNING, "Max retries exceeded to host %s on %s (type = %u, subclass = %d, ts=%u, seqno=%d)\n",
                        ast_sockaddr_stringify_addr(&iaxs[f->callno]->addr),
                        ast_channel_name(iaxs[f->callno]->owner),
                        f->af.frametype,
                        f->af.subclass.integer,
                        f->ts,
                        f->oseqno);
                }
                iaxs[callno]->error = ETIMEDOUT;
                if (iaxs[callno]->owner) {
                    struct ast_frame fr = { AST_FRAME_CONTROL, { AST_CONTROL_HANGUP }, .data.uint32 = AST_CAUSE_DESTINATION_OUT_OF_ORDER };
                    /* Hangup the fd */
                    iax2_queue_frame(callno, &fr); /* XXX */
                    /* Remember, owner could disappear */
                    if (iaxs[callno] && iaxs[callno]->owner)
                        ast_channel_hangupcause_set(iaxs[callno]->owner, AST_CAUSE_DESTINATION_OUT_OF_ORDER);
                } else {
                    if (iaxs[callno]->reg) {
                        memset(&iaxs[callno]->reg->us, 0, sizeof(iaxs[callno]->reg->us));
                        iaxs[callno]->reg->regstate = REG_STATE_TIMEOUT;
                        iaxs[callno]->reg->refresh = IAX_DEFAULT_REG_EXPIRE;
                    }
                    iax2_destroy(callno);
                }
            }
            freeme = 1;
        } else {
            /* Update it if it needs it */
            update_packet(f);
            /* Attempt transmission */
            send_packet(f);
            f->retries++;
            /* Try again later after 10 times as long */
            f->retrytime *= 10;
            if (f->retrytime > MAX_RETRY_TIME)
                f->retrytime = MAX_RETRY_TIME;
            /* Transfer messages max out at one second */
            if (f->transfer && (f->retrytime > 1000))
                f->retrytime = 1000;
            f->retrans = iax2_sched_add(sched, f->retrytime, attempt_transmit, f);
        }
    } else {
        /* Make sure it gets freed */
        f->retries = -1;
        freeme = 1;
    }
 
    if (freeme) {
        /* Don't attempt delivery, just remove it from the queue */
        AST_LIST_REMOVE(&frame_queue[callno], f, list);
        ast_mutex_unlock(&iaxsl[callno]);
        f->retrans = -1; /* this is safe because this is the scheduled function */
        /* Free the IAX frame */
        iax2_frame_free(f);
    } else if (callno) {
        ast_mutex_unlock(&iaxsl[callno]);
    }
}
 
static int attempt_transmit(const void *data)
{
#ifdef SCHED_MULTITHREADED
    if (schedule_action(__attempt_transmit, data))
#endif
        __attempt_transmit(data);
    return 0;
}
 
static char *handle_cli_iax2_prune_realtime(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
    struct iax2_peer *peer = NULL;
    struct iax2_user *user = NULL;
    static const char * const choices[] = { "all", NULL };
    char *cmplt;
 
    switch (cmd) {
    case CLI_INIT:
        e->command = "iax2 prune realtime";
        e->usage =
            "Usage: iax2 prune realtime [<peername>|all]\n"
            "       Prunes object(s) from the cache\n";
        return NULL;
    case CLI_GENERATE:
        if (a->pos == 3) {
            cmplt = ast_cli_complete(a->word, choices, a->n);
            if (!cmplt)
                cmplt = complete_iax2_peers(a->line, a->word, a->pos, a->n - sizeof(choices), IAX_RTCACHEFRIENDS);
            return cmplt;
        }
        return NULL;
    }
    if (a->argc != 4)
        return CLI_SHOWUSAGE;
    if (!strcmp(a->argv[3], "all")) {
        prune_users();
        prune_peers();
        ast_cli(a->fd, "Cache flushed successfully.\n");
        return CLI_SUCCESS;
    }
    peer = find_peer(a->argv[3], 0);
    user = find_user(a->argv[3]);
    if (peer || user) {
        if (peer) {
            if (ast_test_flag64(peer, IAX_RTCACHEFRIENDS)) {
                ast_set_flag64(peer, IAX_RTAUTOCLEAR);
                expire_registry(peer_ref(peer));
                ast_cli(a->fd, "Peer %s was removed from the cache.\n", a->argv[3]);
            } else {
                ast_cli(a->fd, "Peer %s is not eligible for this operation.\n", a->argv[3]);
            }
            peer_unref(peer);
        }
        if (user) {
            if (ast_test_flag64(user, IAX_RTCACHEFRIENDS)) {
                ast_set_flag64(user, IAX_RTAUTOCLEAR);
                ast_cli(a->fd, "User %s was removed from the cache.\n", a->argv[3]);
            } else {
                ast_cli(a->fd, "User %s is not eligible for this operation.\n", a->argv[3]);
            }
            ao2_unlink(users,user);
            user_unref(user);
        }
    } else {
        ast_cli(a->fd, "%s was not found in the cache.\n", a->argv[3]);
    }
 
    return CLI_SUCCESS;
}
 
static char *handle_cli_iax2_test_losspct(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
    switch (cmd) {
    case CLI_INIT:
        e->command = "iax2 test losspct";
        e->usage =
            "Usage: iax2 test losspct <percentage>\n"
            "       For testing, throws away <percentage> percent of incoming packets\n";
        return NULL;
    case CLI_GENERATE:
        return NULL;
    }
    if (a->argc != 4)
        return CLI_SHOWUSAGE;
 
    test_losspct = atoi(a->argv[3]);
 
    return CLI_SUCCESS;
}
 
#ifdef IAXTESTS
static char *handle_cli_iax2_test_late(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
    switch (cmd) {
    case CLI_INIT:
        e->command = "iax2 test late";
        e->usage =
            "Usage: iax2 test late <ms>\n"
            "       For testing, count the next frame as <ms> ms late\n";
        return NULL;
    case CLI_GENERATE:
        return NULL;
    }
 
    if (a->argc != 4)
        return CLI_SHOWUSAGE;
 
    test_late = atoi(a->argv[3]);
 
    return CLI_SUCCESS;
}
 
static char *handle_cli_iax2_test_resync(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
    switch (cmd) {
    case CLI_INIT:
        e->command = "iax2 test resync";
        e->usage =
            "Usage: iax2 test resync <ms>\n"
            "       For testing, adjust all future frames by <ms> ms\n";
        return NULL;
    case CLI_GENERATE:
        return NULL;
    }
 
    if (a->argc != 4)
        return CLI_SHOWUSAGE;
 
    test_resync = atoi(a->argv[3]);
 
    return CLI_SUCCESS;
}
 
static char *handle_cli_iax2_test_jitter(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
    switch (cmd) {
    case CLI_INIT:
        e->command = "iax2 test jitter";
        e->usage =
            "Usage: iax2 test jitter <ms> <pct>\n"
            "       For testing, simulate maximum jitter of +/- <ms> on <pct>\n"
            "       percentage of packets. If <pct> is not specified, adds\n"
            "       jitter to all packets.\n";
        return NULL;
    case CLI_GENERATE:
        return NULL;
    }
 
    if (a->argc < 4 || a->argc > 5)
        return CLI_SHOWUSAGE;
 
    test_jit = atoi(a->argv[3]);
    if (a->argc == 5)
        test_jitpct = atoi(a->argv[4]);
 
    return CLI_SUCCESS;
}
#endif /* IAXTESTS */
 
/*! \brief  peer_status: Report Peer status in character string */
/*  returns 1 if peer is online, -1 if unmonitored */
static int peer_status(struct iax2_peer *peer, char *status, int statuslen)
{
    int res = 0;
    if (peer->maxms) {
        if (peer->lastms < 0) {
            ast_copy_string(status, "UNREACHABLE", statuslen);
        } else if (peer->lastms > peer->maxms) {
            snprintf(status, statuslen, "LAGGED (%d ms)", peer->lastms);
            res = 1;
        } else if (peer->lastms) {
            snprintf(status, statuslen, "OK (%d ms)", peer->lastms);
            res = 1;
        } else {
            ast_copy_string(status, "UNKNOWN", statuslen);
        }
    } else {
        ast_copy_string(status, "Unmonitored", statuslen);
        res = -1;
    }
    return res;
}
 
/*! \brief Show one peer in detail */
static char *handle_cli_iax2_show_peer(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
    char status[64];
    char cbuf[256];
    struct iax2_peer *peer;
    struct ast_str *codec_buf = ast_str_alloca(AST_FORMAT_CAP_NAMES_LEN);
    struct ast_str *encmethods = ast_str_alloca(256);
    int load_realtime = 0;
 
    switch (cmd) {
    case CLI_INIT:
        e->command = "iax2 show peer";
        e->usage =
            "Usage: iax2 show peer <name>\n"
            "       Display details on specific IAX peer\n";
        return NULL;
    case CLI_GENERATE:
        if (a->pos == 3)
            return complete_iax2_peers(a->line, a->word, a->pos, a->n, 0);
        return NULL;
    }
 
    if (a->argc < 4)
        return CLI_SHOWUSAGE;
 
    load_realtime = (a->argc == 5 && !strcmp(a->argv[4], "load")) ? 1 : 0;
 
    peer = find_peer(a->argv[3], load_realtime);
    if (peer) {
        char *str_addr, *str_defaddr;
        char *str_port, *str_defport;
 
        str_addr = ast_strdupa(ast_sockaddr_stringify_addr(&peer->addr));
        str_port = ast_strdupa(ast_sockaddr_stringify_port(&peer->addr));
        str_defaddr = ast_strdupa(ast_sockaddr_stringify_addr(&peer->defaddr));
        str_defport = ast_strdupa(ast_sockaddr_stringify_port(&peer->defaddr));
 
        encmethods_to_str(peer->encmethods, &encmethods);
        ast_cli(a->fd, "\n\n");
        ast_cli(a->fd, "  * Name       : %s\n", peer->name);
        ast_cli(a->fd, "  Description  : %s\n", peer->description);
        ast_cli(a->fd, "  Secret       : %s\n", ast_strlen_zero(peer->secret) ? "<Not set>" : "<Set>");
        ast_cli(a->fd, "  Context      : %s\n", peer->context);
        ast_cli(a->fd, "  Parking lot  : %s\n", peer->parkinglot);
        ast_cli(a->fd, "  Mailbox      : %s\n", peer->mailbox);
        ast_cli(a->fd, "  Dynamic      : %s\n", ast_test_flag64(peer, IAX_DYNAMIC) ? "Yes" : "No");
        ast_cli(a->fd, "  Callnum limit: %d\n", peer->maxcallno);
        ast_cli(a->fd, "  Calltoken req: %s\n", (peer->calltoken_required == CALLTOKEN_YES) ? "Yes" : ((peer->calltoken_required == CALLTOKEN_AUTO) ? "Auto" : "No"));
        ast_cli(a->fd, "  Trunk        : %s\n", ast_test_flag64(peer, IAX_TRUNK) ? "Yes" : "No");
        ast_cli(a->fd, "  Encryption   : %s\n", peer->encmethods ? ast_str_buffer(encmethods) : "No");
        ast_cli(a->fd, "  Callerid     : %s\n", ast_callerid_merge(cbuf, sizeof(cbuf), peer->cid_name, peer->cid_num, "<unspecified>"));
        ast_cli(a->fd, "  Expire       : %d\n", peer->expire);
        ast_cli(a->fd, "  ACL          : %s\n", (ast_acl_list_is_empty(peer->acl) ? "No" : "Yes"));
        ast_cli(a->fd, "  Addr->IP     : %s Port %s\n",  str_addr ? str_addr : "(Unspecified)", str_port);
        ast_cli(a->fd, "  Defaddr->IP  : %s Port %s\n", str_defaddr, str_defport);
        ast_cli(a->fd, "  Username     : %s\n", peer->username);
        ast_cli(a->fd, "  Codecs       : %s\n", iax2_getformatname_multiple(peer->capability, &codec_buf));
 
        if (iax2_codec_pref_string(&peer->prefs, cbuf, sizeof(cbuf)) < 0) {
            strcpy(cbuf, "Error"); /* Safe */
        }
        ast_cli(a->fd, "  Codec Order  : %s\n", cbuf);
 
        peer_status(peer, status, sizeof(status));
        ast_cli(a->fd, "  Status       : %s\n", status);
        ast_cli(a->fd, "  Qualify      : every %dms when OK, every %dms when UNREACHABLE (sample smoothing %s)\n", peer->pokefreqok, peer->pokefreqnotok, peer->smoothing ? "On" : "Off");
        ast_cli(a->fd, "\n");
        peer_unref(peer);
    } else {
        ast_cli(a->fd, "Peer %s not found.\n", a->argv[3]);
        ast_cli(a->fd, "\n");
    }
 
    return CLI_SUCCESS;
}
 
static char *complete_iax2_peers(const char *line, const char *word, int pos, int state, uint64_t flags)
{
    int which = 0;
    struct iax2_peer *peer;
    char *res = NULL;
    int wordlen = strlen(word);
    struct ao2_iterator i;
 
    i = ao2_iterator_init(peers, 0);
    while ((peer = ao2_iterator_next(&i))) {
        if (!strncasecmp(peer->name, word, wordlen) && ++which > state
            && (!flags || ast_test_flag64(peer, flags))) {
            res = ast_strdup(peer->name);
            peer_unref(peer);
            break;
        }
        peer_unref(peer);
    }
    ao2_iterator_destroy(&i);
 
    return res;
}
 
static char *handle_cli_iax2_show_stats(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
    struct iax_frame *cur;
    int cnt = 0, dead = 0, final = 0, i = 0;
 
    switch (cmd) {
    case CLI_INIT:
        e->command = "iax2 show stats";
        e->usage =
            "Usage: iax2 show stats\n"
            "       Display statistics on IAX channel driver.\n";
        return NULL;
    case CLI_GENERATE:
        return NULL;
    }
 
    if (a->argc != 3)
        return CLI_SHOWUSAGE;
 
    for (i = 0; i < ARRAY_LEN(frame_queue); i++) {
        ast_mutex_lock(&iaxsl[i]);
        AST_LIST_TRAVERSE(&frame_queue[i], cur, list) {
            if (cur->retries < 0)
                dead++;
            if (cur->final)
                final++;
            cnt++;
        }
        ast_mutex_unlock(&iaxsl[i]);
    }
 
    ast_cli(a->fd, "    IAX Statistics\n");
    ast_cli(a->fd, "---------------------\n");
    ast_cli(a->fd, "Outstanding frames: %d (%d ingress, %d egress)\n", iax_get_frames(), iax_get_iframes(), iax_get_oframes());
    ast_cli(a->fd, "%d timed and %d untimed transmits; MTU %d/%d/%d\n", trunk_timed, trunk_untimed,
        trunk_maxmtu, trunk_nmaxmtu, global_max_trunk_mtu);
    ast_cli(a->fd, "Packets in transmit queue: %d dead, %d final, %d total\n\n", dead, final, cnt);
 
    trunk_timed = trunk_untimed = 0;
    if (trunk_maxmtu > trunk_nmaxmtu)
        trunk_nmaxmtu = trunk_maxmtu;
 
    return CLI_SUCCESS;
}
 
/*! \brief Set trunk MTU from CLI */
static char *handle_cli_iax2_set_mtu(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
    int mtuv;
 
    switch (cmd) {
    case CLI_INIT:
        e->command = "iax2 set mtu";
        e->usage =
            "Usage: iax2 set mtu <value>\n"
            "       Set the system-wide IAX IP mtu to <value> bytes net or\n"
            "       zero to disable. Disabling means that the operating system\n"
            "       must handle fragmentation of UDP packets when the IAX2 trunk\n"
            "       packet exceeds the UDP payload size. This is substantially\n"
            "       below the IP mtu. Try 1240 on ethernets. Must be 172 or\n"
            "       greater for G.711 samples.\n";
        return NULL;
    case CLI_GENERATE:
        return NULL;
    }
 
    if (a->argc != 4)
        return CLI_SHOWUSAGE;
    if (strncasecmp(a->argv[3], "default", strlen(a->argv[3])) == 0)
        mtuv = MAX_TRUNK_MTU;
    else
        mtuv = atoi(a->argv[3]);
 
    if (mtuv == 0) {
        ast_cli(a->fd, "Trunk MTU control disabled (mtu was %d)\n", global_max_trunk_mtu);
        global_max_trunk_mtu = 0;
        return CLI_SUCCESS;
    }
    if (mtuv < 172 || mtuv > 4000) {
        ast_cli(a->fd, "Trunk MTU must be between 172 and 4000\n");
        return CLI_SHOWUSAGE;
    }
    ast_cli(a->fd, "Trunk MTU changed from %d to %d\n", global_max_trunk_mtu, mtuv);
    global_max_trunk_mtu = mtuv;
    return CLI_SUCCESS;
}
 
static char *handle_cli_iax2_show_cache(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
    struct iax2_dpcache *dp = NULL;
    char tmp[1024], *pc = NULL;
    int s, x, y;
    struct timeval now = ast_tvnow();
 
    switch (cmd) {
    case CLI_INIT:
        e->command = "iax2 show cache";
        e->usage =
            "Usage: iax2 show cache\n"
            "       Display currently cached IAX Dialplan results.\n";
        return NULL;
    case CLI_GENERATE:
        return NULL;
    }
 
    AST_LIST_LOCK(&dpcache);
 
    ast_cli(a->fd, "%-20.20s %-12.12s %-9.9s %-8.8s %s\n", "Peer/Context", "Exten", "Exp.", "Wait.", "Flags");
 
    AST_LIST_TRAVERSE(&dpcache, dp, cache_list) {
        s = dp->expiry.tv_sec - now.tv_sec;
        tmp[0] = '\0';
        if (dp->flags & CACHE_FLAG_EXISTS)
            strncat(tmp, "EXISTS|", sizeof(tmp) - strlen(tmp) - 1);
        if (dp->flags & CACHE_FLAG_NONEXISTENT)
            strncat(tmp, "NONEXISTENT|", sizeof(tmp) - strlen(tmp) - 1);
        if (dp->flags & CACHE_FLAG_CANEXIST)
            strncat(tmp, "CANEXIST|", sizeof(tmp) - strlen(tmp) - 1);
        if (dp->flags & CACHE_FLAG_PENDING)
            strncat(tmp, "PENDING|", sizeof(tmp) - strlen(tmp) - 1);
        if (dp->flags & CACHE_FLAG_TIMEOUT)
            strncat(tmp, "TIMEOUT|", sizeof(tmp) - strlen(tmp) - 1);
        if (dp->flags & CACHE_FLAG_TRANSMITTED)
            strncat(tmp, "TRANSMITTED|", sizeof(tmp) - strlen(tmp) - 1);
        if (dp->flags & CACHE_FLAG_MATCHMORE)
            strncat(tmp, "MATCHMORE|", sizeof(tmp) - strlen(tmp) - 1);
        if (dp->flags & CACHE_FLAG_UNKNOWN)
            strncat(tmp, "UNKNOWN|", sizeof(tmp) - strlen(tmp) - 1);
        /* Trim trailing pipe */
        if (!ast_strlen_zero(tmp)) {
            tmp[strlen(tmp) - 1] = '\0';
        } else {
            ast_copy_string(tmp, "(none)", sizeof(tmp));
        }
        y = 0;
        pc = strchr(dp->peercontext, '@');
        if (!pc) {
            pc = dp->peercontext;
        } else {
            pc++;
        }
        for (x = 0; x < ARRAY_LEN(dp->waiters); x++) {
            if (dp->waiters[x] > -1)
                y++;
        }
        if (s > 0) {
            ast_cli(a->fd, "%-20.20s %-12.12s %-9d %-8d %s\n", pc, dp->exten, s, y, tmp);
        } else {
            ast_cli(a->fd, "%-20.20s %-12.12s %-9.9s %-8d %s\n", pc, dp->exten, "(expired)", y, tmp);
        }
    }
 
    AST_LIST_UNLOCK(&dpcache);
 
    return CLI_SUCCESS;
}
 
static unsigned int calc_rxstamp(struct chan_iax2_pvt *p, unsigned int offset);
 
static void unwrap_timestamp(struct iax_frame *fr)
{
    /* Video mini frames only encode the lower 15 bits of the session
     * timestamp, but other frame types (e.g. audio) encode 16 bits. */
    const int ts_shift = (fr->af.frametype == AST_FRAME_VIDEO) ? 15 : 16;
    const int lower_mask = (1 << ts_shift) - 1;
    const int upper_mask = ~lower_mask;
    const int last_upper = iaxs[fr->callno]->last & upper_mask;
 
    if ( (fr->ts & upper_mask) == last_upper ) {
        const int x = fr->ts - iaxs[fr->callno]->last;
        const int threshold = (ts_shift == 15) ? 25000 : 50000;
 
        if (x < -threshold) {
            /* Sudden big jump backwards in timestamp:
               What likely happened here is that miniframe timestamp has circled but we haven't
               gotten the update from the main packet.  We'll just pretend that we did, and
               update the timestamp appropriately. */
            fr->ts = (last_upper + (1 << ts_shift)) | (fr->ts & lower_mask);
            if (iaxdebug)
                ast_debug(1, "schedule_delivery: pushed forward timestamp\n");
        } else if (x > threshold) {
            /* Sudden apparent big jump forwards in timestamp:
               What's likely happened is this is an old miniframe belonging to the previous
               top 15 or 16-bit timestamp that has turned up out of order.
               Adjust the timestamp appropriately. */
            fr->ts = (last_upper - (1 << ts_shift)) | (fr->ts & lower_mask);
            if (iaxdebug)
                ast_debug(1, "schedule_delivery: pushed back timestamp\n");
        }