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Asterisk developer's documentation


channel.h

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00001 /*
00002  * Asterisk -- An open source telephony toolkit.
00003  *
00004  * Copyright (C) 1999 - 2006, Digium, Inc.
00005  *
00006  * Mark Spencer <markster@digium.com>
00007  *
00008  * See http://www.asterisk.org for more information about
00009  * the Asterisk project. Please do not directly contact
00010  * any of the maintainers of this project for assistance;
00011  * the project provides a web site, mailing lists and IRC
00012  * channels for your use.
00013  *
00014  * This program is free software, distributed under the terms of
00015  * the GNU General Public License Version 2. See the LICENSE file
00016  * at the top of the source tree.
00017  */
00018 
00019 /*! \file
00020  * \brief General Asterisk PBX channel definitions.
00021  * \par See also:
00022  *  \arg \ref Def_Channel
00023  *  \arg \ref channel_drivers
00024  */
00025 
00026 /*! \page Def_Channel Asterisk Channels
00027    \par What is a Channel?
00028    A phone call through Asterisk consists of an incoming
00029    connection and an outbound connection. Each call comes
00030    in through a channel driver that supports one technology,
00031    like SIP, ZAP, IAX2 etc. 
00032    \par
00033    Each channel driver, technology, has it's own private
00034    channel or dialog structure, that is technology-dependent.
00035    Each private structure is "owned" by a generic Asterisk
00036    channel structure, defined in channel.h and handled by
00037    channel.c .
00038    \par Call scenario
00039    This happens when an incoming call arrives to Asterisk
00040    -# Call arrives on a channel driver interface
00041    -# Channel driver creates a PBX channel and starts a 
00042       pbx thread on the channel
00043    -# The dial plan is executed
00044    -# At this point at least two things can happen:
00045       -# The call is answered by Asterisk and 
00046          Asterisk plays a media stream or reads media
00047       -# The dial plan forces Asterisk to create an outbound 
00048          call somewhere with the dial (see \ref app_dial.c)
00049          application
00050    .
00051 
00052    \par Bridging channels
00053    If Asterisk dials out this happens:
00054    -# Dial creates an outbound PBX channel and asks one of the
00055       channel drivers to create a call
00056    -# When the call is answered, Asterisk bridges the media streams
00057       so the caller on the first channel can speak with the callee
00058       on the second, outbound channel
00059    -# In some cases where we have the same technology on both
00060       channels and compatible codecs, a native bridge is used.
00061       In a native bridge, the channel driver handles forwarding
00062       of incoming audio to the outbound stream internally, without
00063       sending audio frames through the PBX.
00064    -# In SIP, theres an "external native bridge" where Asterisk
00065       redirects the endpoint, so audio flows directly between the
00066       caller's phone and the callee's phone. Signalling stays in
00067       Asterisk in order to be able to provide a proper CDR record
00068       for the call.
00069 
00070    
00071    \par Masquerading channels
00072    In some cases, a channel can masquerade itself into another
00073    channel. This happens frequently in call transfers, where 
00074    a new channel takes over a channel that is already involved
00075    in a call. The new channel sneaks in and takes over the bridge
00076    and the old channel, now a zombie, is hung up.
00077    
00078    \par Reference
00079    \arg channel.c - generic functions
00080    \arg channel.h - declarations of functions, flags and structures
00081    \arg translate.h - Transcoding support functions
00082    \arg \ref channel_drivers - Implemented channel drivers
00083    \arg \ref Def_Frame Asterisk Multimedia Frames
00084 
00085 */
00086 
00087 #ifndef _ASTERISK_CHANNEL_H
00088 #define _ASTERISK_CHANNEL_H
00089 
00090 #include "asterisk/abstract_jb.h"
00091 
00092 /* Max length of the uniqueid */
00093 #define AST_MAX_UNIQUEID 64
00094 
00095 #include <unistd.h>
00096 #ifdef POLLCOMPAT 
00097 #include "asterisk/poll-compat.h"
00098 #else
00099 #include <sys/poll.h>
00100 #endif
00101 
00102 #if defined(__cplusplus) || defined(c_plusplus)
00103 extern "C" {
00104 #endif
00105 
00106 #define AST_MAX_EXTENSION  80 /*!< Max length of an extension */
00107 #define AST_MAX_CONTEXT    80 /*!< Max length of a context */
00108 #define AST_CHANNEL_NAME   80 /*!< Max length of an ast_channel name */
00109 #define MAX_LANGUAGE    20 /*!< Max length of the language setting */
00110 #define MAX_MUSICCLASS     80 /*!< Max length of the music class setting */
00111 
00112 #include "asterisk/compat.h"
00113 #include "asterisk/frame.h"
00114 #include "asterisk/sched.h"
00115 #include "asterisk/chanvars.h"
00116 #include "asterisk/config.h"
00117 #include "asterisk/lock.h"
00118 #include "asterisk/cdr.h"
00119 #include "asterisk/utils.h"
00120 #include "asterisk/linkedlists.h"
00121 #include "asterisk/stringfields.h"
00122 #include "asterisk/compiler.h"
00123 
00124 #define DATASTORE_INHERIT_FOREVER   INT_MAX
00125 
00126 #define AST_MAX_FDS     8
00127 /*
00128  * We have AST_MAX_FDS file descriptors in a channel.
00129  * Some of them have a fixed use:
00130  */
00131 #define AST_ALERT_FD (AST_MAX_FDS-1)      /*!< used for alertpipe */
00132 #define AST_TIMING_FD   (AST_MAX_FDS-2)      /*!< used for timingfd */
00133 #define AST_AGENT_FD (AST_MAX_FDS-3)      /*!< used by agents for pass through */
00134 #define AST_GENERATOR_FD   (AST_MAX_FDS-4)   /*!< used by generator */
00135 
00136 enum ast_bridge_result {
00137    AST_BRIDGE_COMPLETE = 0,
00138    AST_BRIDGE_FAILED = -1,
00139    AST_BRIDGE_FAILED_NOWARN = -2,
00140    AST_BRIDGE_RETRY = -3,
00141 };
00142 
00143 typedef unsigned long long ast_group_t;
00144 
00145 struct ast_generator {
00146    void *(*alloc)(struct ast_channel *chan, void *params);
00147    void (*release)(struct ast_channel *chan, void *data);
00148    /*! This function gets called with the channel locked */
00149    int (*generate)(struct ast_channel *chan, void *data, int len, int samples);
00150 };
00151 
00152 /*! \brief Structure for a data store type */
00153 struct ast_datastore_info {
00154    const char *type;    /*!< Type of data store */
00155    void *(*duplicate)(void *data); /*!< Duplicate item data (used for inheritance) */
00156    void (*destroy)(void *data);  /*!< Destroy function */
00157 };
00158 
00159 /*! \brief Structure for a channel data store */
00160 struct ast_datastore {
00161    char *uid;     /*!< Unique data store identifier */
00162    void *data;    /*!< Contained data */
00163    const struct ast_datastore_info *info; /*!< Data store type information */
00164    unsigned int inheritance;  /*!Number of levels this item will continue to be inherited */
00165    AST_LIST_ENTRY(ast_datastore) entry; /*!< Used for easy linking */
00166 };
00167 
00168 /*! \brief Structure for all kinds of caller ID identifications.
00169  * \note All string fields here are malloc'ed, so they need to be
00170  * freed when the structure is deleted.
00171  * Also, NULL and "" must be considered equivalent.
00172  */
00173 struct ast_callerid {
00174    char *cid_dnid;      /*!< Malloc'd Dialed Number Identifier */
00175    char *cid_num;    /*!< Malloc'd Caller Number */
00176    char *cid_name;      /*!< Malloc'd Caller Name */
00177    char *cid_ani;    /*!< Malloc'd ANI */
00178    char *cid_rdnis;  /*!< Malloc'd RDNIS */
00179    int cid_pres;     /*!< Callerid presentation/screening */
00180    int cid_ani2;     /*!< Callerid ANI 2 (Info digits) */
00181    int cid_ton;      /*!< Callerid Type of Number */
00182    int cid_tns;      /*!< Callerid Transit Network Select */
00183 };
00184 
00185 /*! \brief 
00186    Structure to describe a channel "technology", ie a channel driver 
00187    See for examples:
00188    \arg chan_iax2.c - The Inter-Asterisk exchange protocol
00189    \arg chan_sip.c - The SIP channel driver
00190    \arg chan_zap.c - PSTN connectivity (TDM, PRI, T1/E1, FXO, FXS)
00191 
00192    If you develop your own channel driver, this is where you
00193    tell the PBX at registration of your driver what properties
00194    this driver supports and where different callbacks are 
00195    implemented.
00196 */
00197 struct ast_channel_tech {
00198    const char * const type;
00199    const char * const description;
00200 
00201    int capabilities;    /*!< Bitmap of formats this channel can handle */
00202 
00203    int properties;         /*!< Technology Properties */
00204 
00205    /*! \brief Requester - to set up call data structures (pvt's) */
00206    struct ast_channel *(* const requester)(const char *type, int format, void *data, int *cause);
00207 
00208    int (* const devicestate)(void *data); /*!< Devicestate call back */
00209 
00210    /*! \brief Start sending a literal DTMF digit */
00211    int (* const send_digit_begin)(struct ast_channel *chan, char digit);
00212 
00213    /*! \brief Stop sending a literal DTMF digit */
00214    int (* const send_digit_end)(struct ast_channel *chan, char digit, unsigned int duration);
00215 
00216    /*! \brief Call a given phone number (address, etc), but don't
00217       take longer than timeout seconds to do so.  */
00218    int (* const call)(struct ast_channel *chan, char *addr, int timeout);
00219 
00220    /*! \brief Hangup (and possibly destroy) the channel */
00221    int (* const hangup)(struct ast_channel *chan);
00222 
00223    /*! \brief Answer the channel */
00224    int (* const answer)(struct ast_channel *chan);
00225 
00226    /*! \brief Read a frame, in standard format (see frame.h) */
00227    struct ast_frame * (* const read)(struct ast_channel *chan);
00228 
00229    /*! \brief Write a frame, in standard format (see frame.h) */
00230    int (* const write)(struct ast_channel *chan, struct ast_frame *frame);
00231 
00232    /*! \brief Display or transmit text */
00233    int (* const send_text)(struct ast_channel *chan, const char *dest, const char *text, int ispdu);
00234 
00235    /*! \brief Display or send an image */
00236    int (* const send_image)(struct ast_channel *chan, struct ast_frame *frame);
00237 
00238    /*! \brief Send HTML data */
00239    int (* const send_html)(struct ast_channel *chan, int subclass, const char *data, int len);
00240 
00241    /*! \brief Handle an exception, reading a frame */
00242    struct ast_frame * (* const exception)(struct ast_channel *chan);
00243 
00244    /*! \brief Bridge two channels of the same type together */
00245    enum ast_bridge_result (* const bridge)(struct ast_channel *c0, struct ast_channel *c1, int flags,
00246                   struct ast_frame **fo, struct ast_channel **rc, int timeoutms);
00247 
00248    /*! \brief Indicate a particular condition (e.g. AST_CONTROL_BUSY or AST_CONTROL_RINGING or AST_CONTROL_CONGESTION */
00249    int (* const indicate)(struct ast_channel *c, int condition, const void *data, size_t datalen);
00250 
00251    /*! \brief Fix up a channel:  If a channel is consumed, this is called.  Basically update any ->owner links */
00252    int (* const fixup)(struct ast_channel *oldchan, struct ast_channel *newchan);
00253 
00254    /*! \brief Set a given option */
00255    int (* const setoption)(struct ast_channel *chan, int option, void *data, int datalen);
00256 
00257    /*! \brief Query a given option */
00258    int (* const queryoption)(struct ast_channel *chan, int option, void *data, int *datalen);
00259 
00260    /*! \brief Blind transfer other side (see app_transfer.c and ast_transfer() */
00261    int (* const transfer)(struct ast_channel *chan, const char *newdest);
00262 
00263    /*! \brief Write a frame, in standard format */
00264    int (* const write_video)(struct ast_channel *chan, struct ast_frame *frame);
00265 
00266    /*! \brief Find bridged channel */
00267    struct ast_channel *(* const bridged_channel)(struct ast_channel *chan, struct ast_channel *bridge);
00268 
00269    /*! \brief Provide additional read items for CHANNEL() dialplan function */
00270    int (* func_channel_read)(struct ast_channel *chan, char *function, char *data, char *buf, size_t len);
00271 
00272    /*! \brief Provide additional write items for CHANNEL() dialplan function */
00273    int (* func_channel_write)(struct ast_channel *chan, char *function, char *data, const char *value);
00274 
00275    /*! \brief Retrieve base channel (agent and local) */
00276    struct ast_channel* (* get_base_channel)(struct ast_channel *chan);
00277    
00278    /*! \brief Set base channel (agent and local) */
00279    int (* set_base_channel)(struct ast_channel *chan, struct ast_channel *base);
00280 };
00281 
00282 struct ast_channel_spy_list;
00283 struct ast_channel_whisper_buffer;
00284 
00285 #define  DEBUGCHAN_FLAG  0x80000000
00286 #define  FRAMECOUNT_INC(x) ( ((x) & DEBUGCHAN_FLAG) | (((x)+1) & ~DEBUGCHAN_FLAG) )
00287 
00288 enum ast_channel_adsicpe {
00289    AST_ADSI_UNKNOWN,
00290    AST_ADSI_AVAILABLE,
00291    AST_ADSI_UNAVAILABLE,
00292    AST_ADSI_OFFHOOKONLY,
00293 };
00294 
00295 /*! 
00296  * \brief ast_channel states
00297  *
00298  * \note Bits 0-15 of state are reserved for the state (up/down) of the line
00299  *       Bits 16-32 of state are reserved for flags
00300  */
00301 enum ast_channel_state {
00302    /*! Channel is down and available */
00303    AST_STATE_DOWN,
00304    /*! Channel is down, but reserved */
00305    AST_STATE_RESERVED,
00306    /*! Channel is off hook */
00307    AST_STATE_OFFHOOK,
00308    /*! Digits (or equivalent) have been dialed */
00309    AST_STATE_DIALING,
00310    /*! Line is ringing */
00311    AST_STATE_RING,
00312    /*! Remote end is ringing */
00313    AST_STATE_RINGING,
00314    /*! Line is up */
00315    AST_STATE_UP,
00316    /*! Line is busy */
00317    AST_STATE_BUSY,
00318    /*! Digits (or equivalent) have been dialed while offhook */
00319    AST_STATE_DIALING_OFFHOOK,
00320    /*! Channel has detected an incoming call and is waiting for ring */
00321    AST_STATE_PRERING,
00322 
00323    /*! Do not transmit voice data */
00324    AST_STATE_MUTE = (1 << 16),
00325 };
00326 
00327 /*! \brief Main Channel structure associated with a channel. 
00328  * This is the side of it mostly used by the pbx and call management.
00329  *
00330  * \note XXX It is important to remember to increment .cleancount each time
00331  *       this structure is changed. XXX
00332  */
00333 struct ast_channel {
00334    /*! \brief Technology (point to channel driver) */
00335    const struct ast_channel_tech *tech;
00336 
00337    /*! \brief Private data used by the technology driver */
00338    void *tech_pvt;
00339 
00340    AST_DECLARE_STRING_FIELDS(
00341       AST_STRING_FIELD(name);       /*!< ASCII unique channel name */
00342       AST_STRING_FIELD(language);      /*!< Language requested for voice prompts */
00343       AST_STRING_FIELD(musicclass);    /*!< Default music class */
00344       AST_STRING_FIELD(accountcode);      /*!< Account code for billing */
00345       AST_STRING_FIELD(call_forward);     /*!< Where to forward to if asked to dial on this interface */
00346       AST_STRING_FIELD(uniqueid);      /*!< Unique Channel Identifier */
00347    );
00348    
00349    /*! \brief File descriptor for channel -- Drivers will poll on these file descriptors, so at least one must be non -1.  */
00350    int fds[AST_MAX_FDS];         
00351 
00352    void *music_state;            /*!< Music State*/
00353    void *generatordata;          /*!< Current generator data if there is any */
00354    struct ast_generator *generator;    /*!< Current active data generator */
00355 
00356    /*! \brief Who are we bridged to, if we're bridged. Who is proxying for us,
00357      if we are proxied (i.e. chan_agent).
00358      Do not access directly, use ast_bridged_channel(chan) */
00359    struct ast_channel *_bridge;
00360    struct ast_channel *masq;        /*!< Channel that will masquerade as us */
00361    struct ast_channel *masqr;       /*!< Who we are masquerading as */
00362    int cdrflags;              /*!< Call Detail Record Flags */
00363 
00364    /*! \brief Whether or not we have been hung up...  Do not set this value
00365        directly, use ast_softhangup */
00366    int _softhangup;
00367    time_t   whentohangup;           /*!< Non-zero, set to actual time when channel is to be hung up */
00368    pthread_t blocker;            /*!< If anyone is blocking, this is them */
00369    ast_mutex_t lock;          /*!< Lock, can be used to lock a channel for some operations */
00370    const char *blockproc;           /*!< Procedure causing blocking */
00371 
00372    const char *appl;          /*!< Current application */
00373    const char *data;          /*!< Data passed to current application */
00374    int fdno;               /*!< Which fd had an event detected on */
00375    struct sched_context *sched;        /*!< Schedule context */
00376    int streamid;              /*!< For streaming playback, the schedule ID */
00377    struct ast_filestream *stream;         /*!< Stream itself. */
00378    int vstreamid;             /*!< For streaming video playback, the schedule ID */
00379    struct ast_filestream *vstream;        /*!< Video Stream itself. */
00380    int oldwriteformat;           /*!< Original writer format */
00381    
00382    int timingfd;              /*!< Timing fd */
00383    int (*timingfunc)(const void *data);
00384    void *timingdata;
00385 
00386    enum ast_channel_state _state;         /*!< State of line -- Don't write directly, use ast_setstate */
00387    int rings;              /*!< Number of rings so far */
00388    struct ast_callerid cid;         /*!< Caller ID, name, presentation etc */
00389    char dtmfq[AST_MAX_EXTENSION];         /*!< Any/all queued DTMF characters */
00390    struct ast_frame dtmff;          /*!< DTMF frame */
00391 
00392    char context[AST_MAX_CONTEXT];         /*!< Dialplan: Current extension context */
00393    char exten[AST_MAX_EXTENSION];         /*!< Dialplan: Current extension number */
00394    int priority;              /*!< Dialplan: Current extension priority */
00395    char macrocontext[AST_MAX_CONTEXT];    /*!< Macro: Current non-macro context. See app_macro.c */
00396    char macroexten[AST_MAX_EXTENSION];    /*!< Macro: Current non-macro extension. See app_macro.c */
00397    int macropriority;            /*!< Macro: Current non-macro priority. See app_macro.c */
00398    char dialcontext[AST_MAX_CONTEXT];              /*!< Dial: Extension context that we were called from */
00399 
00400    struct ast_pbx *pbx;          /*!< PBX private structure for this channel */
00401    int amaflags;              /*!< Set BEFORE PBX is started to determine AMA flags */
00402    struct ast_cdr *cdr;          /*!< Call Detail Record */
00403    enum ast_channel_adsicpe adsicpe;      /*!< Whether or not ADSI is detected on CPE */
00404 
00405    struct tone_zone *zone;          /*!< Tone zone as set in indications.conf or
00406                         in the CHANNEL dialplan function */
00407 
00408    struct ast_channel_monitor *monitor;      /*!< Channel monitoring */
00409 
00410    /*! Track the read/written samples for monitor use */
00411    unsigned long insmpl;
00412    unsigned long outsmpl;
00413 
00414    /* Frames in/out counters. The high bit is a debug mask, so
00415     * the counter is only in the remaining bits
00416     */
00417    unsigned int fin;
00418    unsigned int fout;
00419    int hangupcause;           /*!< Why is the channel hanged up. See causes.h */
00420    struct varshead varshead;        /*!< A linked list for channel variables */
00421    ast_group_t callgroup;           /*!< Call group for call pickups */
00422    ast_group_t pickupgroup;         /*!< Pickup group - which calls groups can be picked up? */
00423    unsigned int flags;           /*!< channel flags of AST_FLAG_ type */
00424    unsigned short transfercapability;     /*!< ISDN Transfer Capbility - AST_FLAG_DIGITAL is not enough */
00425    AST_LIST_HEAD_NOLOCK(, ast_frame) readq;
00426    char lowlayercompat[16];         /*!< ISDN Low Layer Compatibility */
00427    int alertpipe[2];
00428 
00429    int nativeformats;            /*!< Kinds of data this channel can natively handle */
00430    int readformat;               /*!< Requested read format */
00431    int writeformat;           /*!< Requested write format */
00432    struct ast_trans_pvt *writetrans;      /*!< Write translation path */
00433    struct ast_trans_pvt *readtrans;    /*!< Read translation path */
00434    int rawreadformat;            /*!< Raw read format */
00435    int rawwriteformat;           /*!< Raw write format */
00436 
00437    struct ast_channel_spy_list *spies;    /*!< Chan Spy stuff */
00438    struct ast_channel_whisper_buffer *whisper;  /*!< Whisper Paging buffer */
00439    AST_LIST_ENTRY(ast_channel) chan_list;    /*!< For easy linking */
00440    
00441    struct ast_jb jb;          /*!< The jitterbuffer state  */
00442 
00443    char emulate_dtmf_digit;         /*!< Digit being emulated */
00444    unsigned int emulate_dtmf_duration; /*!< Number of ms left to emulate DTMF for */
00445    struct timeval dtmf_tv;       /*!< The time that an in process digit began, or the last digit ended */
00446 
00447    int visible_indication;                         /*!< Indication currently playing on the channel */
00448 
00449    /*! \brief Data stores on the channel */
00450    AST_LIST_HEAD_NOLOCK(datastores, ast_datastore) datastores;
00451 };
00452 
00453 /*! \brief ast_channel_tech Properties */
00454 enum {
00455    /*! \brief Channels have this property if they can accept input with jitter; 
00456     *         i.e. most VoIP channels */
00457    AST_CHAN_TP_WANTSJITTER = (1 << 0),
00458    /*! \brief Channels have this property if they can create jitter; 
00459     *         i.e. most VoIP channels */
00460    AST_CHAN_TP_CREATESJITTER = (1 << 1),
00461 };
00462 
00463 /*! \brief ast_channel flags */
00464 enum {
00465    /*! Queue incoming dtmf, to be released when this flag is turned off */
00466    AST_FLAG_DEFER_DTMF =    (1 << 1),
00467    /*! write should be interrupt generator */
00468    AST_FLAG_WRITE_INT =     (1 << 2),
00469    /*! a thread is blocking on this channel */
00470    AST_FLAG_BLOCKING =      (1 << 3),
00471    /*! This is a zombie channel */
00472    AST_FLAG_ZOMBIE =        (1 << 4),
00473    /*! There is an exception pending */
00474    AST_FLAG_EXCEPTION =     (1 << 5),
00475    /*! Listening to moh XXX anthm promises me this will disappear XXX */
00476    AST_FLAG_MOH =           (1 << 6),
00477    /*! This channel is spying on another channel */
00478    AST_FLAG_SPYING =        (1 << 7),
00479    /*! This channel is in a native bridge */
00480    AST_FLAG_NBRIDGE =       (1 << 8),
00481    /*! the channel is in an auto-incrementing dialplan processor,
00482     *  so when ->priority is set, it will get incremented before
00483     *  finding the next priority to run */
00484    AST_FLAG_IN_AUTOLOOP =   (1 << 9),
00485    /*! This is an outgoing call */
00486    AST_FLAG_OUTGOING =      (1 << 10),
00487    /*! This channel is being whispered on */
00488    AST_FLAG_WHISPER =       (1 << 11),
00489    /*! A DTMF_BEGIN frame has been read from this channel, but not yet an END */
00490    AST_FLAG_IN_DTMF =       (1 << 12),
00491    /*! A DTMF_END was received when not IN_DTMF, so the length of the digit is 
00492     *  currently being emulated */
00493    AST_FLAG_EMULATE_DTMF =  (1 << 13),
00494    /*! This is set to tell the channel not to generate DTMF begin frames, and
00495     *  to instead only generate END frames. */
00496    AST_FLAG_END_DTMF_ONLY = (1 << 14),
00497    /*! This flag indicates that on a masquerade, an active stream should not
00498     *  be carried over */
00499    AST_FLAG_MASQ_NOSTREAM = (1 << 15),
00500 };
00501 
00502 /*! \brief ast_bridge_config flags */
00503 enum {
00504    AST_FEATURE_PLAY_WARNING = (1 << 0),
00505    AST_FEATURE_REDIRECT =     (1 << 1),
00506    AST_FEATURE_DISCONNECT =   (1 << 2),
00507    AST_FEATURE_ATXFER =       (1 << 3),
00508    AST_FEATURE_AUTOMON =      (1 << 4),
00509    AST_FEATURE_PARKCALL =     (1 << 5),
00510 };
00511 
00512 struct ast_bridge_config {
00513    struct ast_flags features_caller;
00514    struct ast_flags features_callee;
00515    struct timeval start_time;
00516    long feature_timer;
00517    long timelimit;
00518    long play_warning;
00519    long warning_freq;
00520    const char *warning_sound;
00521    const char *end_sound;
00522    const char *start_sound;
00523    int firstpass;
00524    unsigned int flags;
00525 };
00526 
00527 struct chanmon;
00528 
00529 #define LOAD_OH(oh) {   \
00530    oh.context = context; \
00531    oh.exten = exten; \
00532    oh.priority = priority; \
00533    oh.cid_num = cid_num; \
00534    oh.cid_name = cid_name; \
00535    oh.account = account; \
00536    oh.vars = vars; \
00537    oh.parent_channel = NULL; \
00538 } 
00539 
00540 struct outgoing_helper {
00541    const char *context;
00542    const char *exten;
00543    int priority;
00544    const char *cid_num;
00545    const char *cid_name;
00546    const char *account;
00547    struct ast_variable *vars;
00548    struct ast_channel *parent_channel;
00549 };
00550 
00551 enum {
00552    AST_CDR_TRANSFER =   (1 << 0),
00553    AST_CDR_FORWARD =    (1 << 1),
00554    AST_CDR_CALLWAIT =   (1 << 2),
00555    AST_CDR_CONFERENCE = (1 << 3),
00556 };
00557 
00558 enum {
00559    /*! Soft hangup by device */
00560    AST_SOFTHANGUP_DEV =       (1 << 0),
00561    /*! Soft hangup for async goto */
00562    AST_SOFTHANGUP_ASYNCGOTO = (1 << 1),
00563    AST_SOFTHANGUP_SHUTDOWN =  (1 << 2),
00564    AST_SOFTHANGUP_TIMEOUT =   (1 << 3),
00565    AST_SOFTHANGUP_APPUNLOAD = (1 << 4),
00566    AST_SOFTHANGUP_EXPLICIT =  (1 << 5),
00567    AST_SOFTHANGUP_UNBRIDGE =  (1 << 6),
00568 };
00569 
00570 
00571 /*! \brief Channel reload reasons for manager events at load or reload of configuration */
00572 enum channelreloadreason {
00573    CHANNEL_MODULE_LOAD,
00574    CHANNEL_MODULE_RELOAD,
00575    CHANNEL_CLI_RELOAD,
00576    CHANNEL_MANAGER_RELOAD,
00577 };
00578 
00579 /*! \brief Create a channel datastore structure */
00580 struct ast_datastore *ast_channel_datastore_alloc(const struct ast_datastore_info *info, char *uid);
00581 
00582 /*! \brief Free a channel datastore structure */
00583 int ast_channel_datastore_free(struct ast_datastore *datastore);
00584 
00585 /*! \brief Inherit datastores from a parent to a child. */
00586 int ast_channel_datastore_inherit(struct ast_channel *from, struct ast_channel *to);
00587 
00588 /*! \brief Add a datastore to a channel */
00589 int ast_channel_datastore_add(struct ast_channel *chan, struct ast_datastore *datastore);
00590 
00591 /*! \brief Remove a datastore from a channel */
00592 int ast_channel_datastore_remove(struct ast_channel *chan, struct ast_datastore *datastore);
00593 
00594 /*! \brief Find a datastore on a channel */
00595 struct ast_datastore *ast_channel_datastore_find(struct ast_channel *chan, const struct ast_datastore_info *info, char *uid);
00596 
00597 extern ast_mutex_t uniquelock;         
00598 
00599 /*! \brief Change the state of a channel and the callerid of the calling channel*/
00600 int ast_setstate_and_cid(struct ast_channel *chan, enum ast_channel_state state, char *cid_num, char *cid_name);
00601 
00602 /*! \brief Change the state of a channel */
00603 int ast_setstate(struct ast_channel *chan, enum ast_channel_state state);
00604 
00605 /*! \brief Create a channel structure 
00606     \return Returns NULL on failure to allocate.
00607    \note New channels are 
00608    by default set to the "default" context and
00609    extension "s"
00610  */
00611 struct ast_channel *ast_channel_alloc(int needqueue, int state, const char *cid_num, const char *cid_name, const char *acctcode, const char *exten, const char *context, const int amaflag, const char *name_fmt, ...);
00612 
00613 /*! \brief Queue an outgoing frame */
00614 int ast_queue_frame(struct ast_channel *chan, struct ast_frame *f);
00615 
00616 /*! \brief Queue a hangup frame */
00617 int ast_queue_hangup(struct ast_channel *chan);
00618 
00619 /*!
00620   \brief Queue a control frame with payload
00621   \param chan channel to queue frame onto
00622   \param control type of control frame
00623   \return zero on success, non-zero on failure
00624 */
00625 int ast_queue_control(struct ast_channel *chan, enum ast_control_frame_type control);
00626 
00627 /*!
00628   \brief Queue a control frame with payload
00629   \param chan channel to queue frame onto
00630   \param control type of control frame
00631   \param data pointer to payload data to be included in frame
00632   \param datalen number of bytes of payload data
00633   \return zero on success, non-zero on failure
00634 
00635   The supplied payload data is copied into the frame, so the caller's copy
00636   is not modified nor freed, and the resulting frame will retain a copy of
00637   the data even if the caller frees their local copy.
00638 
00639   \note This method should be treated as a 'network transport'; in other
00640   words, your frames may be transferred across an IAX2 channel to another
00641   system, which may be a different endianness than yours. Because of this,
00642   you should ensure that either your frames will never be expected to work
00643   across systems, or that you always put your payload data into 'network byte
00644   order' before calling this function.
00645 */
00646 int ast_queue_control_data(struct ast_channel *chan, enum ast_control_frame_type control,
00647             const void *data, size_t datalen);
00648 
00649 /*! \brief Change channel name */
00650 void ast_change_name(struct ast_channel *chan, char *newname);
00651 
00652 /*! \brief Free a channel structure */
00653 void  ast_channel_free(struct ast_channel *);
00654 
00655 /*! \brief Requests a channel 
00656  * \param type type of channel to request
00657  * \param format requested channel format (codec)
00658  * \param data data to pass to the channel requester
00659  * \param status status
00660  * Request a channel of a given type, with data as optional information used 
00661  * by the low level module
00662  * \return Returns an ast_channel on success, NULL on failure.
00663  */
00664 struct ast_channel *ast_request(const char *type, int format, void *data, int *status);
00665 
00666 /*! \brief Requests a channel 
00667  * \param type type of channel to request
00668  * \param format requested channel format (codec)
00669  * \param data data to pass to the channel requester
00670  * \param status status
00671  * \param uniqueid uniqueid
00672  * Request a channel of a given type, with data as optional information used 
00673  * by the low level module. Sets the channels uniqueid to 'uniqueid'.
00674  * \return Returns an ast_channel on success, NULL on failure.
00675  */
00676 struct ast_channel *ast_request_with_uniqueid(const char *type, int format, void *data, int *status, char *uniqueid);
00677 
00678 /*!
00679  * \brief Request a channel of a given type, with data as optional information used 
00680  * by the low level module and attempt to place a call on it
00681  * \param type type of channel to request
00682  * \param format requested channel format
00683  * \param data data to pass to the channel requester
00684  * \param timeout maximum amount of time to wait for an answer
00685  * \param reason why unsuccessful (if unsuceessful)
00686  * \param cidnum Caller-ID Number
00687  * \param cidname Caller-ID Name
00688  * \return Returns an ast_channel on success or no answer, NULL on failure.  Check the value of chan->_state
00689  * to know if the call was answered or not.
00690  */
00691 struct ast_channel *ast_request_and_dial(const char *type, int format, void *data, int timeout, int *reason, int callingpres, const char *cidnum, const char *cidname, char *uniqueid);
00692 
00693 struct ast_channel *__ast_request_and_dial(const char *type, int format, void *data, int timeout, int *reason, int callingpres, const char *cidnum, const char *cidname, struct outgoing_helper *oh, char *uniqueid);
00694 
00695 /*! \brief "Requests" a channel for sending a message
00696  * \param type type of channel to request
00697  * \param data data to pass to the channel requester
00698  * \param status status
00699  * Request a channel of a given type, with data as optional information used 
00700  * by the low level module
00701  * \return Returns 0 on success, -1 on failure.
00702  */
00703 int ast_send_message(const char *type, void *data, char *to, char *from, char *message, int ispdu);
00704  
00705 /*!\brief Register a channel technology (a new channel driver)
00706  * Called by a channel module to register the kind of channels it supports.
00707  * \param tech Structure defining channel technology or "type"
00708  * \return Returns 0 on success, -1 on failure.
00709  */
00710 int ast_channel_register(const struct ast_channel_tech *tech);
00711 
00712 /*! \brief Unregister a channel technology 
00713  * \param tech Structure defining channel technology or "type" that was previously registered
00714  * \return No return value.
00715  */
00716 void ast_channel_unregister(const struct ast_channel_tech *tech);
00717 
00718 /*! \brief Get a channel technology structure by name
00719  * \param name name of technology to find
00720  * \return a pointer to the structure, or NULL if no matching technology found
00721  */
00722 const struct ast_channel_tech *ast_get_channel_tech(const char *name);
00723 
00724 /*! \brief Hang up a channel  
00725  * \note This function performs a hard hangup on a channel.  Unlike the soft-hangup, this function
00726  * performs all stream stopping, etc, on the channel that needs to end.
00727  * chan is no longer valid after this call.
00728  * \param chan channel to hang up
00729  * \return Returns 0 on success, -1 on failure.
00730  */
00731 int ast_hangup(struct ast_channel *chan);
00732 
00733 /*! \brief Softly hangup up a channel 
00734  * \param chan channel to be soft-hung-up
00735  * Call the protocol layer, but don't destroy the channel structure (use this if you are trying to
00736  * safely hangup a channel managed by another thread.
00737  * \param cause   Ast hangupcause for hangup
00738  * \return Returns 0 regardless
00739  */
00740 int ast_softhangup(struct ast_channel *chan, int cause);
00741 
00742 /*! \brief Softly hangup up a channel (no channel lock) 
00743  * \param chan channel to be soft-hung-up
00744  * \param cause   Ast hangupcause for hangup (see cause.h) */
00745 int ast_softhangup_nolock(struct ast_channel *chan, int cause);
00746 
00747 /*! \brief Check to see if a channel is needing hang up 
00748  * \param chan channel on which to check for hang up
00749  * This function determines if the channel is being requested to be hung up.
00750  * \return Returns 0 if not, or 1 if hang up is requested (including time-out).
00751  */
00752 int ast_check_hangup(struct ast_channel *chan);
00753 
00754 /*! \brief Compare a offset with the settings of when to hang a channel up 
00755  * \param chan channel on which to check for hang up
00756  * \param offset offset in seconds from current time
00757  * \return 1, 0, or -1
00758  * This function compares a offset from current time with the absolute time 
00759  * out on a channel (when to hang up). If the absolute time out on a channel
00760  * is earlier than current time plus the offset, it returns 1, if the two
00761  * time values are equal, it return 0, otherwise, it retturn -1.
00762  */
00763 int ast_channel_cmpwhentohangup(struct ast_channel *chan, time_t offset);
00764 
00765 /*! \brief Set when to hang a channel up 
00766  * \param chan channel on which to check for hang up
00767  * \param offset offset in seconds from current time of when to hang up
00768  * This function sets the absolute time out on a channel (when to hang up).
00769  */
00770 void ast_channel_setwhentohangup(struct ast_channel *chan, time_t offset);
00771 
00772 /*! \brief Answer a ringing call 
00773  * \param chan channel to answer
00774  * This function answers a channel and handles all necessary call
00775  * setup functions.
00776  * \return Returns 0 on success, -1 on failure
00777  */
00778 int ast_answer(struct ast_channel *chan);
00779 
00780 /*! \brief Make a call 
00781  * \param chan which channel to make the call on
00782  * \param addr destination of the call
00783  * \param timeout time to wait on for connect
00784  * Place a call, take no longer than timeout ms. 
00785    \return Returns -1 on failure, 0 on not enough time 
00786    (does not automatically stop ringing), and  
00787    the number of seconds the connect took otherwise.
00788    */
00789 int ast_call(struct ast_channel *chan, char *addr, int timeout);
00790 
00791 /*! \brief Indicates condition of channel 
00792  * \note Indicate a condition such as AST_CONTROL_BUSY, AST_CONTROL_RINGING, or AST_CONTROL_CONGESTION on a channel
00793  * \param chan channel to change the indication
00794  * \param condition which condition to indicate on the channel
00795  * \return Returns 0 on success, -1 on failure
00796  */
00797 int ast_indicate(struct ast_channel *chan, int condition);
00798 
00799 /*! \brief Indicates condition of channel, with payload
00800  * \note Indicate a condition such as AST_CONTROL_BUSY, AST_CONTROL_RINGING, or AST_CONTROL_CONGESTION on a channel
00801  * \param chan channel to change the indication
00802  * \param condition which condition to indicate on the channel
00803  * \param data pointer to payload data
00804  * \param datalen size of payload data
00805  * \return Returns 0 on success, -1 on failure
00806  */
00807 int ast_indicate_data(struct ast_channel *chan, int condition, const void *data, size_t datalen);
00808 
00809 /* Misc stuff ------------------------------------------------ */
00810 
00811 /*! \brief Wait for input on a channel 
00812  * \param chan channel to wait on
00813  * \param ms length of time to wait on the channel
00814  * Wait for input on a channel for a given # of milliseconds (<0 for indefinite). 
00815   \return Returns < 0 on  failure, 0 if nothing ever arrived, and the # of ms remaining otherwise */
00816 int ast_waitfor(struct ast_channel *chan, int ms);
00817 
00818 /*! \brief Wait for a specied amount of time, looking for hangups 
00819  * \param chan channel to wait for
00820  * \param ms length of time in milliseconds to sleep
00821  * Waits for a specified amount of time, servicing the channel as required.
00822  * \return returns -1 on hangup, otherwise 0.
00823  */
00824 int ast_safe_sleep(struct ast_channel *chan, int ms);
00825 
00826 /*! \brief Wait for a specied amount of time, looking for hangups and a condition argument 
00827  * \param chan channel to wait for
00828  * \param ms length of time in milliseconds to sleep
00829  * \param cond a function pointer for testing continue condition
00830  * \param data argument to be passed to the condition test function
00831  * \return returns -1 on hangup, otherwise 0.
00832  * Waits for a specified amount of time, servicing the channel as required. If cond
00833  * returns 0, this function returns.
00834  */
00835 int ast_safe_sleep_conditional(struct ast_channel *chan, int ms, int (*cond)(void*), void *data );
00836 
00837 /*! \brief Waits for activity on a group of channels 
00838  * \param chan an array of pointers to channels
00839  * \param n number of channels that are to be waited upon
00840  * \param fds an array of fds to wait upon
00841  * \param nfds the number of fds to wait upon
00842  * \param exception exception flag
00843  * \param outfd fd that had activity on it
00844  * \param ms how long the wait was
00845  * Big momma function here.  Wait for activity on any of the n channels, or any of the nfds
00846    file descriptors.
00847    \return Returns the channel with activity, or NULL on error or if an FD
00848    came first.  If the FD came first, it will be returned in outfd, otherwise, outfd
00849    will be -1 */
00850 struct ast_channel *ast_waitfor_nandfds(struct ast_channel **chan, int n, int *fds, int nfds, int *exception, int *outfd, int *ms);
00851 
00852 /*! \brief Waits for input on a group of channels
00853    Wait for input on an array of channels for a given # of milliseconds. 
00854    \return Return channel with activity, or NULL if none has activity.  
00855    \param chan an array of pointers to channels
00856    \param n number of channels that are to be waited upon
00857    \param ms time "ms" is modified in-place, if applicable */
00858 struct ast_channel *ast_waitfor_n(struct ast_channel **chan, int n, int *ms);
00859 
00860 /*! \brief Waits for input on an fd
00861    This version works on fd's only.  Be careful with it. */
00862 int ast_waitfor_n_fd(int *fds, int n, int *ms, int *exception);
00863 
00864 
00865 /*! \brief Reads a frame
00866  * \param chan channel to read a frame from
00867    Read a frame.  
00868    \return Returns a frame, or NULL on error.  If it returns NULL, you
00869       best just stop reading frames and assume the channel has been
00870       disconnected. */
00871 struct ast_frame *ast_read(struct ast_channel *chan);
00872 
00873 /*! \brief Reads a frame, returning AST_FRAME_NULL frame if audio. 
00874  * Read a frame. 
00875    \param chan channel to read a frame from
00876    \return  Returns a frame, or NULL on error.  If it returns NULL, you
00877       best just stop reading frames and assume the channel has been
00878       disconnected.  
00879    \note Audio is replaced with AST_FRAME_NULL to avoid 
00880    transcode when the resulting audio is not necessary. */
00881 struct ast_frame *ast_read_noaudio(struct ast_channel *chan);
00882 
00883 /*! \brief Write a frame to a channel 
00884  * This function writes the given frame to the indicated channel.
00885  * \param chan destination channel of the frame
00886  * \param frame frame that will be written
00887  * \return It returns 0 on success, -1 on failure.
00888  */
00889 int ast_write(struct ast_channel *chan, struct ast_frame *frame);
00890 
00891 /*! \brief Write video frame to a channel 
00892  * This function writes the given frame to the indicated channel.
00893  * \param chan destination channel of the frame
00894  * \param frame frame that will be written
00895  * \return It returns 1 on success, 0 if not implemented, and -1 on failure.
00896  */
00897 int ast_write_video(struct ast_channel *chan, struct ast_frame *frame);
00898 
00899 /*! \brief Send empty audio to prime a channel driver */
00900 int ast_prod(struct ast_channel *chan);
00901 
00902 /*! \brief Sets read format on channel chan
00903  * Set read format for channel to whichever component of "format" is best. 
00904  * \param chan channel to change
00905  * \param format format to change to
00906  * \return Returns 0 on success, -1 on failure
00907  */
00908 int ast_set_read_format(struct ast_channel *chan, int format);
00909 
00910 /*! \brief Sets write format on channel chan
00911  * Set write format for channel to whichever compoent of "format" is best. 
00912  * \param chan channel to change
00913  * \param format new format for writing
00914  * \return Returns 0 on success, -1 on failure
00915  */
00916 int ast_set_write_format(struct ast_channel *chan, int format);
00917 
00918 /*! \brief Sends text to a channel 
00919  * Write text to a display on a channel
00920  * \param chan channel to act upon
00921  * \param dest destination number/user
00922  * \param text string of text to send on the channel
00923  * \param ispdu message is in PDU format
00924  * \return Returns 0 on success, -1 on failure
00925  */
00926 int ast_sendtext(struct ast_channel *chan, const char *dest, const char *text, int ispdu);
00927 
00928 /*! \brief Receives a text character from a channel
00929  * \param chan channel to act upon
00930  * \param timeout timeout in milliseconds (0 for infinite wait)
00931  * Read a char of text from a channel
00932  * Returns 0 on success, -1 on failure
00933  */
00934 int ast_recvchar(struct ast_channel *chan, int timeout);
00935 
00936 /*! \brief Send a DTMF digit to a channel
00937  * Send a DTMF digit to a channel.
00938  * \param chan channel to act upon
00939  * \param digit the DTMF digit to send, encoded in ASCII
00940  * \return Returns 0 on success, -1 on failure
00941  */
00942 int ast_senddigit(struct ast_channel *chan, char digit);
00943 
00944 int ast_senddigit_begin(struct ast_channel *chan, char digit);
00945 int ast_senddigit_end(struct ast_channel *chan, char digit, unsigned int duration);
00946 
00947 /*! \brief Receives a text string from a channel
00948  * Read a string of text from a channel
00949  * \param chan channel to act upon
00950  * \param timeout timeout in milliseconds (0 for infinite wait)
00951  * \return the received text, or NULL to signify failure.
00952  */
00953 char *ast_recvtext(struct ast_channel *chan, int timeout);
00954 
00955 /*! \brief Browse channels in use
00956  * Browse the channels currently in use 
00957  * \param prev where you want to start in the channel list
00958  * \return Returns the next channel in the list, NULL on end.
00959  *    If it returns a channel, that channel *has been locked*!
00960  */
00961 struct ast_channel *ast_channel_walk_locked(const struct ast_channel *prev);
00962 
00963 /*! \brief Get channel by name (locks channel) */
00964 struct ast_channel *ast_get_channel_by_name_locked(const char *chan);
00965 
00966 /*! \brief Get channel by name prefix (locks channel) */
00967 struct ast_channel *ast_get_channel_by_name_prefix_locked(const char *name, const int namelen);
00968 
00969 /*! \brief Get channel by name prefix (locks channel) */
00970 struct ast_channel *ast_walk_channel_by_name_prefix_locked(const struct ast_channel *chan, const char *name, const int namelen);
00971 
00972 /*! \brief Get channel by exten (and optionally context) and lock it */
00973 struct ast_channel *ast_get_channel_by_exten_locked(const char *exten, const char *context);
00974 
00975 /*! \brief Get next channel by exten (and optionally context) and lock it */
00976 struct ast_channel *ast_walk_channel_by_exten_locked(const struct ast_channel *chan, const char *exten,
00977                        const char *context);
00978 /*! Get channel by uniqueid (locks channel) */
00979 struct ast_channel *ast_get_channel_by_uniqueid_locked(const char *uniqueid);
00980 
00981 /*! ! \brief Waits for a digit
00982  * \param c channel to wait for a digit on
00983  * \param ms how many milliseconds to wait
00984  * \return Returns <0 on error, 0 on no entry, and the digit on success. */
00985 int ast_waitfordigit(struct ast_channel *c, int ms);
00986 
00987 /*! \brief Wait for a digit
00988  Same as ast_waitfordigit() with audio fd for outputting read audio and ctrlfd to monitor for reading. 
00989  * \param c channel to wait for a digit on
00990  * \param ms how many milliseconds to wait
00991  * \param audiofd audio file descriptor to write to if audio frames are received
00992  * \param ctrlfd control file descriptor to monitor for reading
00993  * \return Returns 1 if ctrlfd becomes available */
00994 int ast_waitfordigit_full(struct ast_channel *c, int ms, int audiofd, int ctrlfd);
00995 
00996 /*! Reads multiple digits 
00997  * \param c channel to read from
00998  * \param s string to read in to.  Must be at least the size of your length
00999  * \param len how many digits to read (maximum)
01000  * \param timeout how long to timeout between digits
01001  * \param rtimeout timeout to wait on the first digit
01002  * \param enders digits to end the string
01003  * Read in a digit string "s", max length "len", maximum timeout between 
01004    digits "timeout" (-1 for none), terminated by anything in "enders".  Give them rtimeout
01005    for the first digit.  Returns 0 on normal return, or 1 on a timeout.  In the case of
01006    a timeout, any digits that were read before the timeout will still be available in s.  
01007    RETURNS 2 in full version when ctrlfd is available, NOT 1*/
01008 int ast_readstring(struct ast_channel *c, char *s, int len, int timeout, int rtimeout, char *enders);
01009 int ast_readstring_full(struct ast_channel *c, char *s, int len, int timeout, int rtimeout, char *enders, int audiofd, int ctrlfd);
01010 
01011 char *ast_alloc_uniqueid(void);
01012 
01013 /*! \brief Report DTMF on channel 0 */
01014 #define AST_BRIDGE_DTMF_CHANNEL_0      (1 << 0)    
01015 /*! \brief Report DTMF on channel 1 */
01016 #define AST_BRIDGE_DTMF_CHANNEL_1      (1 << 1)    
01017 /*! \brief Return all voice frames on channel 0 */
01018 #define AST_BRIDGE_REC_CHANNEL_0    (1 << 2)    
01019 /*! \brief Return all voice frames on channel 1 */
01020 #define AST_BRIDGE_REC_CHANNEL_1    (1 << 3)    
01021 /*! \brief Ignore all signal frames except NULL */
01022 #define AST_BRIDGE_IGNORE_SIGS         (1 << 4)    
01023 
01024 
01025 /*! \brief Makes two channel formats compatible 
01026  * \param c0 first channel to make compatible
01027  * \param c1 other channel to make compatible
01028  * Set two channels to compatible formats -- call before ast_channel_bridge in general .  
01029  * \return Returns 0 on success and -1 if it could not be done */
01030 int ast_channel_make_compatible(struct ast_channel *c0, struct ast_channel *c1);
01031 
01032 /*! Bridge two channels together 
01033  * \param c0 first channel to bridge
01034  * \param c1 second channel to bridge
01035  * \param config config for the channels
01036  * \param fo destination frame(?)
01037  * \param rc destination channel(?)
01038  * Bridge two channels (c0 and c1) together.  If an important frame occurs, we return that frame in
01039    *rf (remember, it could be NULL) and which channel (0 or 1) in rc */
01040 /* int ast_channel_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, struct ast_frame **fo, struct ast_channel **rc); */
01041 int ast_channel_bridge(struct ast_channel *c0,struct ast_channel *c1,struct ast_bridge_config *config, struct ast_frame **fo, struct ast_channel **rc);
01042 
01043 /*! \brief Weird function made for call transfers
01044  * \param original channel to make a copy of
01045  * \param clone copy of the original channel
01046  * This is a very strange and freaky function used primarily for transfer.  Suppose that
01047    "original" and "clone" are two channels in random situations.  This function takes
01048    the guts out of "clone" and puts them into the "original" channel, then alerts the
01049    channel driver of the change, asking it to fixup any private information (like the
01050    p->owner pointer) that is affected by the change.  The physical layer of the original
01051    channel is hung up.  */
01052 int ast_channel_masquerade(struct ast_channel *original, struct ast_channel *clone);
01053 
01054 /*! Gives the string form of a given cause code */
01055 /*! 
01056  * \param state cause to get the description of
01057  * Give a name to a cause code
01058  * Returns the text form of the binary cause code given
01059  */
01060 const char *ast_cause2str(int state) attribute_pure;
01061 
01062 /*! Convert the string form of a cause code to a number */
01063 /*! 
01064  * \param name string form of the cause
01065  * Returns the cause code
01066  */
01067 int ast_str2cause(const char *name) attribute_pure;
01068 
01069 /*! Gives the string form of a given channel state */
01070 /*! 
01071  * \param ast_channel_state state to get the name of
01072  * Give a name to a state 
01073  * Returns the text form of the binary state given
01074  */
01075 char *ast_state2str(enum ast_channel_state);
01076 
01077 /*! Gives the string form of a given transfer capability */
01078 /*!
01079  * \param transfercapability transfercapabilty to get the name of
01080  * Give a name to a transfercapbility
01081  * See above
01082  * Returns the text form of the binary transfer capbility
01083  */
01084 char *ast_transfercapability2str(int transfercapability) attribute_const;
01085 
01086 /* Options: Some low-level drivers may implement "options" allowing fine tuning of the
01087    low level channel.  See frame.h for options.  Note that many channel drivers may support
01088    none or a subset of those features, and you should not count on this if you want your
01089    asterisk application to be portable.  They're mainly useful for tweaking performance */
01090 
01091 /*! Sets an option on a channel */
01092 /*! 
01093  * \param channel channel to set options on
01094  * \param option option to change
01095  * \param data data specific to option
01096  * \param datalen length of the data
01097  * \param block blocking or not
01098  * Set an option on a channel (see frame.h), optionally blocking awaiting the reply 
01099  * Returns 0 on success and -1 on failure
01100  */
01101 int ast_channel_setoption(struct ast_channel *channel, int option, void *data, int datalen, int block);
01102 
01103 /*! Pick the best codec  */
01104 /* Choose the best codec...  Uhhh...   Yah. */
01105 int ast_best_codec(int fmts);
01106 
01107 
01108 /*! Checks the value of an option */
01109 /*! 
01110  * Query the value of an option, optionally blocking until a reply is received
01111  * Works similarly to setoption except only reads the options.
01112  */
01113 struct ast_frame *ast_channel_queryoption(struct ast_channel *channel, int option, void *data, int *datalen, int block);
01114 
01115 /*! Checks for HTML support on a channel */
01116 /*! Returns 0 if channel does not support HTML or non-zero if it does */
01117 int ast_channel_supports_html(struct ast_channel *channel);
01118 
01119 /*! Sends HTML on given channel */
01120 /*! Send HTML or URL on link.  Returns 0 on success or -1 on failure */
01121 int ast_channel_sendhtml(struct ast_channel *channel, int subclass, const char *data, int datalen);
01122 
01123 /*! Sends a URL on a given link */
01124 /*! Send URL on link.  Returns 0 on success or -1 on failure */
01125 int ast_channel_sendurl(struct ast_channel *channel, const char *url);
01126 
01127 /*! Defers DTMF */
01128 /*! Defer DTMF so that you only read things like hangups and audio.  Returns
01129    non-zero if channel was already DTMF-deferred or 0 if channel is just now
01130    being DTMF-deferred */
01131 int ast_channel_defer_dtmf(struct ast_channel *chan);
01132 
01133 /*! Undeos a defer */
01134 /*! Undo defer.  ast_read will return any dtmf characters that were queued */
01135 void ast_channel_undefer_dtmf(struct ast_channel *chan);
01136 
01137 /*! Initiate system shutdown -- prevents new channels from being allocated.
01138     If "hangup" is non-zero, all existing channels will receive soft
01139      hangups */
01140 void ast_begin_shutdown(int hangup);
01141 
01142 /*! Cancels an existing shutdown and returns to normal operation */
01143 void ast_cancel_shutdown(void);
01144 
01145 /*! Returns number of active/allocated channels */
01146 int ast_active_channels(void);
01147 
01148 /*! Returns non-zero if Asterisk is being shut down */
01149 int ast_shutting_down(void);
01150 
01151 /*! Activate a given generator */
01152 int ast_activate_generator(struct ast_channel *chan, struct ast_generator *gen, void *params);
01153 
01154 /*! Deactive an active generator */
01155 void ast_deactivate_generator(struct ast_channel *chan);
01156 
01157 /*!
01158  * \note The channel does not need to be locked before calling this function.
01159  */
01160 void ast_set_callerid(struct ast_channel *chan, const char *cidnum, const char *cidname, const char *ani);
01161 
01162 
01163 /*! return a mallocd string with the result of sprintf of the fmt and following args */
01164 char *ast_safe_string_alloc(const char *fmt, ...);
01165 
01166 
01167 
01168 /*! Start a tone going */
01169 int ast_tonepair_start(struct ast_channel *chan, int freq1, int freq2, int duration, int vol);
01170 /*! Stop a tone from playing */
01171 void ast_tonepair_stop(struct ast_channel *chan);
01172 /*! Play a tone pair for a given amount of time */
01173 int ast_tonepair(struct ast_channel *chan, int freq1, int freq2, int duration, int vol);
01174 
01175 /*!
01176  * \brief Automatically service a channel for us... 
01177  *
01178  * \retval 0 success
01179  * \retval -1 failure, or the channel is already being autoserviced
01180  */
01181 int ast_autoservice_start(struct ast_channel *chan);
01182 
01183 /*! 
01184  * \brief Stop servicing a channel for us...  
01185  *
01186  * \retval 0 success
01187  * \retval -1 error, or the channel has been hungup 
01188  */
01189 int ast_autoservice_stop(struct ast_channel *chan);
01190 
01191 /* If built with zaptel optimizations, force a scheduled expiration on the
01192    timer fd, at which point we call the callback function / data */
01193 int ast_settimeout(struct ast_channel *c, int samples, int (*func)(const void *data), void *data);
01194 
01195 /*!   \brief Transfer a channel (if supported).  Returns -1 on error, 0 if not supported
01196    and 1 if supported and requested 
01197    \param chan current channel
01198    \param dest destination extension for transfer
01199 */
01200 int ast_transfer(struct ast_channel *chan, char *dest);
01201 
01202 /*!   \brief  Start masquerading a channel
01203    XXX This is a seriously wacked out operation.  We're essentially putting the guts of
01204            the clone channel into the original channel.  Start by killing off the original
01205            channel's backend.   I'm not sure we're going to keep this function, because
01206            while the features are nice, the cost is very high in terms of pure nastiness. XXX
01207    \param chan    Channel to masquerade
01208 */
01209 int ast_do_masquerade(struct ast_channel *chan);
01210 
01211 /*!   \brief Find bridged channel 
01212    \param chan Current channel
01213 */
01214 struct ast_channel *ast_bridged_channel(struct ast_channel *chan);
01215 
01216 /*!
01217   \brief Inherits channel variable from parent to child channel
01218   \param parent Parent channel
01219   \param child Child channel
01220 
01221   Scans all channel variables in the parent channel, looking for those
01222   that should be copied into the child channel.
01223   Variables whose names begin with a single '_' are copied into the
01224   child channel with the prefix removed.
01225   Variables whose names begin with '__' are copied into the child
01226   channel with their names unchanged.
01227 */
01228 void ast_channel_inherit_variables(const struct ast_channel *parent, struct ast_channel *child);
01229 
01230 /*!
01231   \brief adds a list of channel variables to a channel
01232   \param chan the channel
01233   \param vars a linked list of variables
01234 
01235   Variable names can be for a regular channel variable or a dialplan function
01236   that has the ability to be written to.
01237 */
01238 void ast_set_variables(struct ast_channel *chan, struct ast_variable *vars);
01239 
01240 /*!
01241   \brief An opaque 'object' structure use by silence generators on channels.
01242  */
01243 struct ast_silence_generator;
01244 
01245 /*!
01246   \brief Starts a silence generator on the given channel.
01247   \param chan The channel to generate silence on
01248   \return An ast_silence_generator pointer, or NULL if an error occurs
01249 
01250   This function will cause SLINEAR silence to be generated on the supplied
01251   channel until it is disabled; if the channel cannot be put into SLINEAR
01252   mode then the function will fail.
01253 
01254   The pointer returned by this function must be preserved and passed to
01255   ast_channel_stop_silence_generator when you wish to stop the silence
01256   generation.
01257  */
01258 struct ast_silence_generator *ast_channel_start_silence_generator(struct ast_channel *chan);
01259 
01260 /*!
01261   \brief Stops a previously-started silence generator on the given channel.
01262   \param chan The channel to operate on
01263   \param state The ast_silence_generator pointer return by a previous call to
01264   ast_channel_start_silence_generator.
01265   \return nothing
01266 
01267   This function will stop the operating silence generator and return the channel
01268   to its previous write format.
01269  */
01270 void ast_channel_stop_silence_generator(struct ast_channel *chan, struct ast_silence_generator *state);
01271 
01272 /*!
01273   \brief Check if the channel can run in internal timing mode.
01274   \param chan The channel to check
01275   \return boolean
01276 
01277   This function will return 1 if internal timing is enabled and the timing
01278   device is available.
01279  */
01280 int ast_internal_timing_enabled(struct ast_channel *chan);
01281 
01282 /* Misc. functions below */
01283 
01284 /*! \brief if fd is a valid descriptor, set *pfd with the descriptor
01285  * \return Return 1 (not -1!) if added, 0 otherwise (so we can add the
01286  * return value to the index into the array)
01287  */
01288 static inline int ast_add_fd(struct pollfd *pfd, int fd)
01289 {
01290    pfd->fd = fd;
01291    pfd->events = POLLIN | POLLPRI;
01292    return fd >= 0;
01293 }
01294 
01295 /*! \brief Helper function for migrating select to poll */
01296 static inline int ast_fdisset(struct pollfd *pfds, int fd, int max, int *start)
01297 {
01298    int x;
01299    int dummy=0;
01300 
01301    if (fd < 0)
01302       return 0;
01303    if (!start)
01304       start = &dummy;
01305    for (x = *start; x<max; x++)
01306       if (pfds[x].fd == fd) {
01307          if (x == *start)
01308             (*start)++;
01309          return pfds[x].revents;
01310       }
01311    return 0;
01312 }
01313 
01314 #ifdef SOLARIS
01315 static inline void timersub(struct timeval *tvend, struct timeval *tvstart, struct timeval *tvdiff)
01316 {
01317    tvdiff->tv_sec = tvend->tv_sec - tvstart->tv_sec;
01318    tvdiff->tv_usec = tvend->tv_usec - tvstart->tv_usec;
01319    if (tvdiff->tv_usec < 0) {
01320       tvdiff->tv_sec --;
01321       tvdiff->tv_usec += 1000000;
01322    }
01323 
01324 }
01325 #endif
01326 
01327 /*! \brief Waits for activity on a group of channels 
01328  * \param nfds the maximum number of file descriptors in the sets
01329  * \param rfds file descriptors to check for read availability
01330  * \param wfds file descriptors to check for write availability
01331  * \param efds file descriptors to check for exceptions (OOB data)
01332  * \param tvp timeout while waiting for events
01333  * This is the same as a standard select(), except it guarantees the
01334  * behaviour where the passed struct timeval is updated with how much
01335  * time was not slept while waiting for the specified events
01336  */
01337 static inline int ast_select(int nfds, fd_set *rfds, fd_set *wfds, fd_set *efds, struct timeval *tvp)
01338 {
01339 #ifdef __linux__
01340    return select(nfds, rfds, wfds, efds, tvp);
01341 #else
01342    if (tvp) {
01343       struct timeval tv, tvstart, tvend, tvlen;
01344       int res;
01345 
01346       tv = *tvp;
01347       gettimeofday(&tvstart, NULL);
01348       res = select(nfds, rfds, wfds, efds, tvp);
01349       gettimeofday(&tvend, NULL);
01350       timersub(&tvend, &tvstart, &tvlen);
01351       timersub(&tv, &tvlen, tvp);
01352       if (tvp->tv_sec < 0 || (tvp->tv_sec == 0 && tvp->tv_usec < 0)) {
01353          tvp->tv_sec = 0;
01354          tvp->tv_usec = 0;
01355       }
01356       return res;
01357    }
01358    else
01359       return select(nfds, rfds, wfds, efds, NULL);
01360 #endif
01361 }
01362 
01363 #ifdef DO_CRASH
01364 #define CRASH do { fprintf(stderr, "!! Forcing immediate crash a-la abort !!\n"); *((int *)0) = 0; } while(0)
01365 #else
01366 #define CRASH do { } while(0)
01367 #endif
01368 
01369 #define CHECK_BLOCKING(c) do {    \
01370    if (ast_test_flag(c, AST_FLAG_BLOCKING)) {\
01371       if (option_debug) \
01372          ast_log(LOG_DEBUG, "Thread %ld Blocking '%s', already blocked by thread %ld in procedure %s\n", (long) pthread_self(), (c)->name, (long) (c)->blocker, (c)->blockproc); \
01373       CRASH; \
01374    } else { \
01375       (c)->blocker = pthread_self(); \
01376       (c)->blockproc = __PRETTY_FUNCTION__; \
01377       ast_set_flag(c, AST_FLAG_BLOCKING); \
01378    } } while (0)
01379 
01380 ast_group_t ast_get_group(const char *s);
01381 
01382 /*! \brief print call- and pickup groups into buffer */
01383 char *ast_print_group(char *buf, int buflen, ast_group_t group);
01384 
01385 /*! \brief Convert enum channelreloadreason to text string for manager event
01386    \param reason  Enum channelreloadreason - reason for reload (manager, cli, start etc)
01387 */
01388 const char *channelreloadreason2txt(enum channelreloadreason reason);
01389 
01390 /*! \brief return an ast_variable list of channeltypes */
01391 struct ast_variable *ast_channeltype_list(void);
01392 
01393 /*!
01394   \brief Begin 'whispering' onto a channel
01395   \param chan The channel to whisper onto
01396   \return 0 for success, non-zero for failure
01397 
01398   This function will add a whisper buffer onto a channel and set a flag
01399   causing writes to the channel to reduce the volume level of the written
01400   audio samples, and then to mix in audio from the whisper buffer if it
01401   is available.
01402 
01403   Note: This function performs no locking; you must hold the channel's lock before
01404   calling this function.
01405  */
01406 int ast_channel_whisper_start(struct ast_channel *chan);
01407 
01408 /*!
01409   \brief Feed an audio frame into the whisper buffer on a channel
01410   \param chan The channel to whisper onto
01411   \param f The frame to to whisper onto chan
01412   \return 0 for success, non-zero for failure
01413  */
01414 int ast_channel_whisper_feed(struct ast_channel *chan, struct ast_frame *f);
01415 
01416 /*!
01417   \brief Stop 'whispering' onto a channel
01418   \param chan The channel to whisper onto
01419   \return 0 for success, non-zero for failure
01420 
01421   Note: This function performs no locking; you must hold the channel's lock before
01422   calling this function.
01423  */
01424 void ast_channel_whisper_stop(struct ast_channel *chan);
01425 
01426 
01427 
01428 /*!
01429   \brief return an english explanation of the code returned thru __ast_request_and_dial's 'outstate' argument
01430   \param reason  The integer argument, usually taken from AST_CONTROL_ macros
01431   \return char pointer explaining the code
01432  */
01433 char *ast_channel_reason2str(int reason);
01434 
01435 
01436 #if defined(__cplusplus) || defined(c_plusplus)
01437 }
01438 #endif
01439 
01440 #endif /* _ASTERISK_CHANNEL_H */

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