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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 /*! \page AstFileDesc File descriptors 
00088    Asterisk File descriptors are connected to each channel (see \ref Def_Channel)
00089    in the \ref ast_channel structure.
00090 */
00091 
00092 #ifndef _ASTERISK_CHANNEL_H
00093 #define _ASTERISK_CHANNEL_H
00094 
00095 #include "asterisk/abstract_jb.h"
00096 
00097 #include <unistd.h>
00098 #ifdef POLLCOMPAT 
00099 #include "asterisk/poll-compat.h"
00100 #else
00101 #include <sys/poll.h>
00102 #endif
00103 
00104 #if defined(__cplusplus) || defined(c_plusplus)
00105 extern "C" {
00106 #endif
00107 
00108 #define AST_MAX_EXTENSION  80 /*!< Max length of an extension */
00109 #define AST_MAX_CONTEXT    80 /*!< Max length of a context */
00110 #define AST_CHANNEL_NAME   80 /*!< Max length of an ast_channel name */
00111 #define MAX_LANGUAGE    20 /*!< Max length of the language setting */
00112 #define MAX_MUSICCLASS     80 /*!< Max length of the music class setting */
00113 
00114 #include "asterisk/compat.h"
00115 #include "asterisk/frame.h"
00116 #include "asterisk/sched.h"
00117 #include "asterisk/chanvars.h"
00118 #include "asterisk/config.h"
00119 #include "asterisk/lock.h"
00120 #include "asterisk/cdr.h"
00121 #include "asterisk/utils.h"
00122 #include "asterisk/linkedlists.h"
00123 #include "asterisk/stringfields.h"
00124 #include "asterisk/options.h"
00125 #include "asterisk/strings.h"
00126 #include "asterisk/compiler.h"
00127 
00128 
00129 #define AST_MAX_FDS     8
00130 /*
00131  * We have AST_MAX_FDS file descriptors in a channel.
00132  * Some of them have a fixed use:
00133  */
00134 #define AST_ALERT_FD (AST_MAX_FDS-1)      /*!< used for alertpipe */
00135 #define AST_TIMING_FD   (AST_MAX_FDS-2)      /*!< used for timingfd */
00136 #define AST_AGENT_FD (AST_MAX_FDS-3)      /*!< used by agents for pass through */
00137 #define AST_GENERATOR_FD   (AST_MAX_FDS-4)   /*!< used by generator */
00138 
00139 enum ast_bridge_result {
00140    AST_BRIDGE_COMPLETE = 0,
00141    AST_BRIDGE_FAILED = -1,
00142    AST_BRIDGE_FAILED_NOWARN = -2,
00143    AST_BRIDGE_RETRY = -3,
00144 };
00145 
00146 typedef unsigned long long ast_group_t;
00147 
00148 /*! \todo Add an explanation of an Asterisk generator 
00149 */
00150 struct ast_generator {
00151    void *(*alloc)(struct ast_channel *chan, void *params);
00152    void (*release)(struct ast_channel *chan, void *data);
00153    int (*generate)(struct ast_channel *chan, void *data, int len, int samples);
00154 };
00155 
00156 /*! \brief Structure for a data store type */
00157 struct ast_datastore_info {
00158    const char *type;    /*!< Type of data store */
00159    void (*destroy)(void *data);  /*!< Destroy function */
00160 };
00161 
00162 /*! \brief Structure for a channel data store */
00163 struct ast_datastore {
00164    char *uid;     /*!< Unique data store identifier */
00165    void *data;    /*!< Contained data */
00166    const struct ast_datastore_info *info; /*!< Data store type information */
00167    AST_LIST_ENTRY(ast_datastore) entry; /*!< Used for easy linking */
00168 };
00169 
00170 /*! \brief Structure for all kinds of caller ID identifications.
00171  * \note All string fields here are malloc'ed, so they need to be
00172  * freed when the structure is deleted.
00173  * Also, NULL and "" must be considered equivalent.
00174  */
00175 struct ast_callerid {
00176    char *cid_dnid;      /*!< Malloc'd Dialed Number Identifier */
00177    char *cid_num;    /*!< Malloc'd Caller Number */
00178    char *cid_name;      /*!< Malloc'd Caller Name */
00179    char *cid_ani;    /*!< Malloc'd ANI */
00180    char *cid_rdnis;  /*!< Malloc'd RDNIS */
00181    int cid_pres;     /*!< Callerid presentation/screening */
00182    int cid_ani2;     /*!< Callerid ANI 2 (Info digits) */
00183    int cid_ton;      /*!< Callerid Type of Number */
00184    int cid_tns;      /*!< Callerid Transit Network Select */
00185 };
00186 
00187 /*! \brief 
00188    Structure to describe a channel "technology", ie a channel driver 
00189    See for examples:
00190    \arg chan_iax2.c - The Inter-Asterisk exchange protocol
00191    \arg chan_sip.c - The SIP channel driver
00192    \arg chan_zap.c - PSTN connectivity (TDM, PRI, T1/E1, FXO, FXS)
00193 
00194    If you develop your own channel driver, this is where you
00195    tell the PBX at registration of your driver what properties
00196    this driver supports and where different callbacks are 
00197    implemented.
00198 */
00199 struct ast_channel_tech {
00200    const char * const type;
00201    const char * const description;
00202 
00203    int capabilities;    /*!< Bitmap of formats this channel can handle */
00204 
00205    int properties;         /*!< Technology Properties */
00206 
00207    /*! \brief Requester - to set up call data structures (pvt's) */
00208    struct ast_channel *(* const requester)(const char *type, int format, void *data, int *cause);
00209 
00210    int (* const devicestate)(void *data); /*!< Devicestate call back */
00211 
00212    /*! \brief Start sending a literal DTMF digit */
00213    int (* const send_digit_begin)(struct ast_channel *chan, char digit);
00214 
00215    /*! \brief Stop sending a literal DTMF digit */
00216    int (* const send_digit_end)(struct ast_channel *chan, char digit, unsigned int duration);
00217 
00218    /*! \brief Call a given phone number (address, etc), but don't
00219       take longer than timeout seconds to do so.  */
00220    int (* const call)(struct ast_channel *chan, char *addr, int timeout);
00221 
00222    /*! \brief Hangup (and possibly destroy) the channel */
00223    int (* const hangup)(struct ast_channel *chan);
00224 
00225    /*! \brief Answer the channel */
00226    int (* const answer)(struct ast_channel *chan);
00227 
00228    /*! \brief Read a frame, in standard format (see frame.h) */
00229    struct ast_frame * (* const read)(struct ast_channel *chan);
00230 
00231    /*! \brief Write a frame, in standard format (see frame.h) */
00232    int (* const write)(struct ast_channel *chan, struct ast_frame *frame);
00233 
00234    /*! \brief Display or transmit text */
00235    int (* const send_text)(struct ast_channel *chan, const char *text);
00236 
00237    /*! \brief Display or send an image */
00238    int (* const send_image)(struct ast_channel *chan, struct ast_frame *frame);
00239 
00240    /*! \brief Send HTML data */
00241    int (* const send_html)(struct ast_channel *chan, int subclass, const char *data, int len);
00242 
00243    /*! \brief Handle an exception, reading a frame */
00244    struct ast_frame * (* const exception)(struct ast_channel *chan);
00245 
00246    /*! \brief Bridge two channels of the same type together */
00247    enum ast_bridge_result (* const bridge)(struct ast_channel *c0, struct ast_channel *c1, int flags,
00248                   struct ast_frame **fo, struct ast_channel **rc, int timeoutms);
00249 
00250    /*! \brief Indicate a particular condition (e.g. AST_CONTROL_BUSY or AST_CONTROL_RINGING or AST_CONTROL_CONGESTION */
00251    int (* const indicate)(struct ast_channel *c, int condition, const void *data, size_t datalen);
00252 
00253    /*! \brief Fix up a channel:  If a channel is consumed, this is called.  Basically update any ->owner links */
00254    int (* const fixup)(struct ast_channel *oldchan, struct ast_channel *newchan);
00255 
00256    /*! \brief Set a given option */
00257    int (* const setoption)(struct ast_channel *chan, int option, void *data, int datalen);
00258 
00259    /*! \brief Query a given option */
00260    int (* const queryoption)(struct ast_channel *chan, int option, void *data, int *datalen);
00261 
00262    /*! \brief Blind transfer other side (see app_transfer.c and ast_transfer() */
00263    int (* const transfer)(struct ast_channel *chan, const char *newdest);
00264 
00265    /*! \brief Write a frame, in standard format */
00266    int (* const write_video)(struct ast_channel *chan, struct ast_frame *frame);
00267 
00268    /*! \brief Find bridged channel */
00269    struct ast_channel *(* const bridged_channel)(struct ast_channel *chan, struct ast_channel *bridge);
00270 
00271    /*! \brief Provide additional read items for CHANNEL() dialplan function */
00272    int (* func_channel_read)(struct ast_channel *chan, char *function, char *data, char *buf, size_t len);
00273 
00274    /*! \brief Provide additional write items for CHANNEL() dialplan function */
00275    int (* func_channel_write)(struct ast_channel *chan, char *function, char *data, const char *value);
00276 };
00277 
00278 struct ast_channel_spy_list;  /*!< \todo Add explanation here */
00279 struct ast_channel_whisper_buffer;  /*!< \todo Add explanation here */
00280 
00281 #define  DEBUGCHAN_FLAG  0x80000000
00282 #define  FRAMECOUNT_INC(x) ( ((x) & DEBUGCHAN_FLAG) | (((x)+1) & ~DEBUGCHAN_FLAG) )
00283 
00284 enum ast_channel_adsicpe {
00285    AST_ADSI_UNKNOWN,
00286    AST_ADSI_AVAILABLE,
00287    AST_ADSI_UNAVAILABLE,
00288    AST_ADSI_OFFHOOKONLY,
00289 };
00290 
00291 /*! 
00292  * \brief ast_channel states
00293  *
00294  * \note Bits 0-15 of state are reserved for the state (up/down) of the line
00295  *       Bits 16-32 of state are reserved for flags
00296  */
00297 enum ast_channel_state {
00298    /*! Channel is down and available */
00299    AST_STATE_DOWN,
00300    /*! Channel is down, but reserved */
00301    AST_STATE_RESERVED,
00302    /*! Channel is off hook */
00303    AST_STATE_OFFHOOK,
00304    /*! Digits (or equivalent) have been dialed */
00305    AST_STATE_DIALING,
00306    /*! Line is ringing */
00307    AST_STATE_RING,
00308    /*! Remote end is ringing */
00309    AST_STATE_RINGING,
00310    /*! Line is up */
00311    AST_STATE_UP,
00312    /*! Line is busy */
00313    AST_STATE_BUSY,
00314    /*! Digits (or equivalent) have been dialed while offhook */
00315    AST_STATE_DIALING_OFFHOOK,
00316    /*! Channel has detected an incoming call and is waiting for ring */
00317    AST_STATE_PRERING,
00318 
00319    /*! Do not transmit voice data */
00320    AST_STATE_MUTE = (1 << 16),
00321 };
00322 
00323 /*! \brief Main Channel structure associated with a channel. 
00324  * This is the side of it mostly used by the pbx and call management.
00325  *
00326  * \note XXX It is important to remember to increment .cleancount each time
00327  *       this structure is changed. XXX
00328  */
00329 struct ast_channel {
00330    /*! \brief Technology (point to channel driver) */
00331    const struct ast_channel_tech *tech;
00332 
00333    /*! \brief Private data used by the technology driver */
00334    void *tech_pvt;
00335 
00336    AST_DECLARE_STRING_FIELDS(
00337       AST_STRING_FIELD(name);       /*!< ASCII unique channel name */
00338       AST_STRING_FIELD(language);      /*!< Language requested for voice prompts */
00339       AST_STRING_FIELD(musicclass);    /*!< Default music class */
00340       AST_STRING_FIELD(accountcode);      /*!< Account code for billing */
00341       AST_STRING_FIELD(call_forward);     /*!< Where to forward to if asked to dial on this interface */
00342       AST_STRING_FIELD(uniqueid);      /*!< Unique Channel Identifier */
00343    );
00344    
00345    /*! \brief File descriptor for channel -- Drivers will poll on these file descriptors, so at least one must be non -1.  See \ref AstFileDesc */
00346    int fds[AST_MAX_FDS];   
00347 
00348    void *music_state;            /*!< Music State*/
00349    void *generatordata;          /*!< Current generator data if there is any */
00350    struct ast_generator *generator;    /*!< Current active data generator */
00351 
00352    /*! \brief Who are we bridged to, if we're bridged. Who is proxying for us,
00353      if we are proxied (i.e. chan_agent).
00354      Do not access directly, use ast_bridged_channel(chan) */
00355    struct ast_channel *_bridge;
00356    struct ast_channel *masq;        /*!< Channel that will masquerade as us */
00357    struct ast_channel *masqr;       /*!< Who we are masquerading as */
00358    int cdrflags;              /*!< Call Detail Record Flags */
00359 
00360    int _softhangup;           /*!< Whether or not we have been hung up...  Do not set this value
00361                            directly, use ast_softhangup() */
00362    time_t   whentohangup;           /*!< Non-zero, set to actual time when channel is to be hung up */
00363    pthread_t blocker;            /*!< If anyone is blocking, this is them */
00364    ast_mutex_t lock;          /*!< Lock, can be used to lock a channel for some operations - see ast_channel_lock() */
00365    const char *blockproc;           /*!< Procedure causing blocking */
00366 
00367    const char *appl;          /*!< Current application */
00368    const char *data;          /*!< Data passed to current application */
00369    int fdno;               /*!< Which fd had an event detected on */
00370    struct sched_context *sched;        /*!< Schedule context */
00371    int streamid;              /*!< For streaming playback, the schedule ID */
00372    struct ast_filestream *stream;         /*!< Stream itself. */
00373    int vstreamid;             /*!< For streaming video playback, the schedule ID */
00374    struct ast_filestream *vstream;        /*!< Video Stream itself. */
00375    int oldwriteformat;           /*!< Original writer format */
00376    
00377    int timingfd;              /*!< Timing fd */
00378    int (*timingfunc)(void *data);
00379    void *timingdata;
00380 
00381    enum ast_channel_state _state;         /*!< State of line -- Don't write directly, use ast_setstate() */
00382    int rings;              /*!< Number of rings so far */
00383    struct ast_callerid cid;         /*!< Caller ID, name, presentation etc */
00384    char dtmfq[AST_MAX_EXTENSION];         /*!< Any/all queued DTMF characters */
00385    struct ast_frame dtmff;          /*!< DTMF frame */
00386 
00387    char context[AST_MAX_CONTEXT];         /*!< Dialplan: Current extension context */
00388    char exten[AST_MAX_EXTENSION];         /*!< Dialplan: Current extension number */
00389    int priority;              /*!< Dialplan: Current extension priority */
00390    char macrocontext[AST_MAX_CONTEXT];    /*!< Macro: Current non-macro context. See app_macro.c */
00391    char macroexten[AST_MAX_EXTENSION];    /*!< Macro: Current non-macro extension. See app_macro.c */
00392    int macropriority;            /*!< Macro: Current non-macro priority. See app_macro.c */
00393    char dialcontext[AST_MAX_CONTEXT];              /*!< Dial: Extension context that we were called from */
00394 
00395    struct ast_pbx *pbx;          /*!< PBX private structure for this channel */
00396    int amaflags;              /*!< Set BEFORE PBX is started to determine AMA flags */
00397    struct ast_cdr *cdr;          /*!< Call Detail Record */
00398    enum ast_channel_adsicpe adsicpe;      /*!< Whether or not ADSI is detected on CPE */
00399 
00400    struct tone_zone *zone;          /*!< Tone zone as set in indications.conf or
00401                         in the CHANNEL dialplan function */
00402 
00403    struct ast_channel_monitor *monitor;      /*!< Channel monitoring */
00404 
00405    unsigned long insmpl;            /*!< Track the read/written samples for monitor use */
00406    unsigned long outsmpl;           /*!< Track the read/written samples for monitor use */
00407 
00408    unsigned int fin;          /*!< Frames in counters. The high bit is a debug mask, so
00409                       * the counter is only in the remaining bits */
00410    unsigned int fout;            /*!< Frames out counters. The high bit is a debug mask, so
00411                       * the counter is only in the remaining bits */
00412    int hangupcause;           /*!< Why is the channel hanged up. See causes.h */
00413    struct varshead varshead;        /*!< A linked list for channel variables 
00414                         (see \ref AstChanVar ) */
00415    ast_group_t callgroup;           /*!< Call group for call pickups */
00416    ast_group_t pickupgroup;         /*!< Pickup group - which calls groups can be picked up? */
00417    unsigned int flags;           /*!< channel flags of AST_FLAG_ type */
00418    unsigned short transfercapability;     /*!< ISDN Transfer Capbility - AST_FLAG_DIGITAL is not enough */
00419    AST_LIST_HEAD_NOLOCK(, ast_frame) readq;
00420    int alertpipe[2];
00421 
00422    int nativeformats;            /*!< Kinds of data this channel can natively handle */
00423    int readformat;               /*!< Requested read format */
00424    int writeformat;           /*!< Requested write format */
00425    struct ast_trans_pvt *writetrans;      /*!< Write translation path */
00426    struct ast_trans_pvt *readtrans;    /*!< Read translation path */
00427    int rawreadformat;            /*!< Raw read format */
00428    int rawwriteformat;           /*!< Raw write format */
00429 
00430    struct ast_channel_spy_list *spies;    /*!< Chan Spy stuff */
00431    struct ast_channel_whisper_buffer *whisper;  /*!< Whisper Paging buffer */
00432    AST_LIST_ENTRY(ast_channel) chan_list;    /*!< For easy linking */
00433    
00434    struct ast_jb jb;          /*!< The jitterbuffer state  */
00435 
00436    char emulate_dtmf_digit;         /*!< Digit being emulated */
00437    unsigned int emulate_dtmf_duration; /*!< Number of ms left to emulate DTMF for */
00438    struct timeval dtmf_tv;       /*!< The time that an in process digit began, or the last digit ended */
00439 
00440    /*! \brief Data stores on the channel */
00441    AST_LIST_HEAD_NOLOCK(datastores, ast_datastore) datastores;
00442 };
00443 
00444 /*! \brief ast_channel_tech Properties */
00445 enum {
00446    /*! \brief Channels have this property if they can accept input with jitter; 
00447     *         i.e. most VoIP channels */
00448    AST_CHAN_TP_WANTSJITTER = (1 << 0),
00449    /*! \brief Channels have this property if they can create jitter; 
00450     *         i.e. most VoIP channels */
00451    AST_CHAN_TP_CREATESJITTER = (1 << 1),
00452 };
00453 
00454 /*! \brief ast_channel flags */
00455 enum {
00456    /*! Queue incoming dtmf, to be released when this flag is turned off */
00457    AST_FLAG_DEFER_DTMF =    (1 << 1),
00458    /*! write should be interrupt generator */
00459    AST_FLAG_WRITE_INT =     (1 << 2),
00460    /*! a thread is blocking on this channel */
00461    AST_FLAG_BLOCKING =      (1 << 3),
00462    /*! This is a zombie channel */
00463    AST_FLAG_ZOMBIE =        (1 << 4),
00464    /*! There is an exception pending */
00465    AST_FLAG_EXCEPTION =     (1 << 5),
00466    /*! Listening to moh XXX anthm promises me this will disappear XXX */
00467    AST_FLAG_MOH =           (1 << 6),
00468    /*! This channel is spying on another channel */
00469    AST_FLAG_SPYING =        (1 << 7),
00470    /*! This channel is in a native bridge */
00471    AST_FLAG_NBRIDGE =       (1 << 8),
00472    /*! the channel is in an auto-incrementing dialplan processor,
00473     *  so when ->priority is set, it will get incremented before
00474     *  finding the next priority to run */
00475    AST_FLAG_IN_AUTOLOOP =   (1 << 9),
00476    /*! This is an outgoing call */
00477    AST_FLAG_OUTGOING =      (1 << 10),
00478    /*! This channel is being whispered on */
00479    AST_FLAG_WHISPER =       (1 << 11),
00480    /*! A DTMF_BEGIN frame has been read from this channel, but not yet an END */
00481    AST_FLAG_IN_DTMF =       (1 << 12),
00482    /*! A DTMF_END was received when not IN_DTMF, so the length of the digit is 
00483     *  currently being emulated */
00484    AST_FLAG_EMULATE_DTMF =  (1 << 13),
00485    /*! This is set to tell the channel not to generate DTMF begin frames, and
00486     *  to instead only generate END frames. */
00487    AST_FLAG_END_DTMF_ONLY = (1 << 14),
00488 };
00489 
00490 /*! \brief ast_bridge_config flags */
00491 enum {
00492    AST_FEATURE_PLAY_WARNING = (1 << 0),
00493    AST_FEATURE_REDIRECT =     (1 << 1),
00494    AST_FEATURE_DISCONNECT =   (1 << 2),
00495    AST_FEATURE_ATXFER =       (1 << 3),
00496    AST_FEATURE_AUTOMON =      (1 << 4),
00497    AST_FEATURE_PARKCALL =     (1 << 5),
00498 };
00499 
00500 /*! \brief bridge configuration */
00501 struct ast_bridge_config {
00502    struct ast_flags features_caller;
00503    struct ast_flags features_callee;
00504    struct timeval start_time;
00505    long feature_timer;
00506    long timelimit;
00507    long play_warning;
00508    long warning_freq;
00509    const char *warning_sound;
00510    const char *end_sound;
00511    const char *start_sound;
00512    int firstpass;
00513    unsigned int flags;
00514 };
00515 
00516 struct chanmon;
00517 
00518 #define LOAD_OH(oh) {   \
00519    oh.context = context; \
00520    oh.exten = exten; \
00521    oh.priority = priority; \
00522    oh.cid_num = cid_num; \
00523    oh.cid_name = cid_name; \
00524    oh.account = account; \
00525    oh.vars = vars; \
00526    oh.parent_channel = NULL; \
00527 } 
00528 
00529 struct outgoing_helper {
00530    const char *context;
00531    const char *exten;
00532    int priority;
00533    const char *cid_num;
00534    const char *cid_name;
00535    const char *account;
00536    struct ast_variable *vars;
00537    struct ast_channel *parent_channel;
00538 };
00539 
00540 enum {
00541    AST_CDR_TRANSFER =   (1 << 0),
00542    AST_CDR_FORWARD =    (1 << 1),
00543    AST_CDR_CALLWAIT =   (1 << 2),
00544    AST_CDR_CONFERENCE = (1 << 3),
00545 };
00546 
00547 enum {
00548    /*! Soft hangup by device */
00549    AST_SOFTHANGUP_DEV =       (1 << 0),
00550    /*! Soft hangup for async goto */
00551    AST_SOFTHANGUP_ASYNCGOTO = (1 << 1),
00552    AST_SOFTHANGUP_SHUTDOWN =  (1 << 2),
00553    AST_SOFTHANGUP_TIMEOUT =   (1 << 3),
00554    AST_SOFTHANGUP_APPUNLOAD = (1 << 4),
00555    AST_SOFTHANGUP_EXPLICIT =  (1 << 5),
00556    AST_SOFTHANGUP_UNBRIDGE =  (1 << 6),
00557 };
00558 
00559 
00560 /*! \brief Channel reload reasons for manager events at load or reload of configuration */
00561 enum channelreloadreason {
00562    CHANNEL_MODULE_LOAD,
00563    CHANNEL_MODULE_RELOAD,
00564    CHANNEL_CLI_RELOAD,
00565    CHANNEL_MANAGER_RELOAD,
00566 };
00567 
00568 /*! \brief Create a channel datastore structure */
00569 struct ast_datastore *ast_channel_datastore_alloc(const struct ast_datastore_info *info, char *uid);
00570 
00571 /*! \brief Free a channel datastore structure */
00572 int ast_channel_datastore_free(struct ast_datastore *datastore);
00573 
00574 /*! \brief Add a datastore to a channel */
00575 int ast_channel_datastore_add(struct ast_channel *chan, struct ast_datastore *datastore);
00576 
00577 /*! \brief Remove a datastore from a channel */
00578 int ast_channel_datastore_remove(struct ast_channel *chan, struct ast_datastore *datastore);
00579 
00580 /*! \brief Find a datastore on a channel */
00581 struct ast_datastore *ast_channel_datastore_find(struct ast_channel *chan, const struct ast_datastore_info *info, char *uid);
00582 
00583 /*! \brief Change the state of a channel */
00584 int ast_setstate(struct ast_channel *chan, enum ast_channel_state);
00585 
00586 /*! \brief Create a channel structure 
00587     \return Returns NULL on failure to allocate.
00588    \note New channels are 
00589    by default set to the "default" context and
00590    extension "s"
00591  */
00592 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, ...);
00593 
00594 /*! \brief Queue an outgoing frame */
00595 int ast_queue_frame(struct ast_channel *chan, struct ast_frame *f);
00596 
00597 /*! \brief Queue a hangup frame */
00598 int ast_queue_hangup(struct ast_channel *chan);
00599 
00600 /*!
00601   \brief Queue a control frame with payload
00602   \param chan channel to queue frame onto
00603   \param control type of control frame
00604   \return zero on success, non-zero on failure
00605 */
00606 int ast_queue_control(struct ast_channel *chan, enum ast_control_frame_type control);
00607 
00608 /*!
00609   \brief Queue a control frame with payload
00610   \param chan channel to queue frame onto
00611   \param control type of control frame
00612   \param data pointer to payload data to be included in frame
00613   \param datalen number of bytes of payload data
00614   \return zero on success, non-zero on failure
00615 
00616   The supplied payload data is copied into the frame, so the caller's copy
00617   is not modified nor freed, and the resulting frame will retain a copy of
00618   the data even if the caller frees their local copy.
00619 
00620   \note This method should be treated as a 'network transport'; in other
00621   words, your frames may be transferred across an IAX2 channel to another
00622   system, which may be a different endianness than yours. Because of this,
00623   you should ensure that either your frames will never be expected to work
00624   across systems, or that you always put your payload data into 'network byte
00625   order' before calling this function.
00626 */
00627 int ast_queue_control_data(struct ast_channel *chan, enum ast_control_frame_type control,
00628             const void *data, size_t datalen);
00629 
00630 /*! \brief Change channel name */
00631 void ast_change_name(struct ast_channel *chan, char *newname);
00632 
00633 /*! \brief Free a channel structure */
00634 void  ast_channel_free(struct ast_channel *);
00635 
00636 /*! \brief Requests a channel 
00637  * \param type type of channel to request
00638  * \param format requested channel format (codec)
00639  * \param data data to pass to the channel requester
00640  * \param status status
00641  * Request a channel of a given type, with data as optional information used 
00642  * by the low level module
00643  * \return Returns an ast_channel on success, NULL on failure.
00644  */
00645 struct ast_channel *ast_request(const char *type, int format, void *data, int *status);
00646 
00647 
00648 /*! \brief call ast_request with format/type of parent channel
00649  */
00650 static inline struct ast_channel *ast_request_inherit(struct ast_channel *chan, const char *type, void *data, int *status)
00651 {
00652    return ast_request(S_OR(type, chan->tech->type), chan->nativeformats, data, status);
00653 }
00654 
00655 /*!
00656  * \brief Request a channel of a given type, with data as optional information used 
00657  * by the low level module and attempt to place a call on it
00658  * \param type type of channel to request
00659  * \param format requested channel format
00660  * \param data data to pass to the channel requester
00661  * \param timeout maximum amount of time to wait for an answer
00662  * \param reason why unsuccessful (if unsuceessful)
00663  * \param cidnum Caller-ID Number
00664  * \param cidname Caller-ID Name
00665  * \return Returns an ast_channel on success or no answer, NULL on failure.  Check the value of chan->_state
00666  * to know if the call was answered or not.
00667  */
00668 struct ast_channel *ast_request_and_dial(const char *type, int format, void *data, int timeout, int *reason, const char *cidnum, const char *cidname);
00669 
00670 struct ast_channel *__ast_request_and_dial(const char *type, int format, void *data, int timeout, int *reason, const char *cidnum, const char *cidname, struct outgoing_helper *oh);
00671 
00672 /*!\brief Register a channel technology (a new channel driver)
00673  * Called by a channel module to register the kind of channels it supports.
00674  * \param tech Structure defining channel technology or "type"
00675  * \return Returns 0 on success, -1 on failure.
00676  */
00677 int ast_channel_register(const struct ast_channel_tech *tech);
00678 
00679 /*! \brief Unregister a channel technology 
00680  * \param tech Structure defining channel technology or "type" that was previously registered
00681  * \return No return value.
00682  */
00683 void ast_channel_unregister(const struct ast_channel_tech *tech);
00684 
00685 /*! \brief Get a channel technology structure by name
00686  * \param name name of technology to find
00687  * \return a pointer to the structure, or NULL if no matching technology found
00688  */
00689 const struct ast_channel_tech *ast_get_channel_tech(const char *name);
00690 
00691 /*! \brief Hang up a channel  
00692  * \note This function performs a hard hangup on a channel.  Unlike the soft-hangup, this function
00693  * performs all stream stopping, etc, on the channel that needs to end.
00694  * chan is no longer valid after this call.
00695  * \param chan channel to hang up
00696  * \return Returns 0 on success, -1 on failure.
00697  */
00698 int ast_hangup(struct ast_channel *chan);
00699 
00700 /*! \brief Softly hangup up a channel 
00701  * \param chan channel to be soft-hung-up
00702  * Call the protocol layer, but don't destroy the channel structure (use this if you are trying to
00703  * safely hangup a channel managed by another thread.
00704  * \param cause   Ast hangupcause for hangup
00705  * \return Returns 0 regardless
00706  */
00707 int ast_softhangup(struct ast_channel *chan, int cause);
00708 
00709 /*! \brief Softly hangup up a channel (no channel lock) 
00710  * \param chan channel to be soft-hung-up
00711  * \param cause   Ast hangupcause for hangup (see cause.h) */
00712 int ast_softhangup_nolock(struct ast_channel *chan, int cause);
00713 
00714 /*! \brief Check to see if a channel is needing hang up 
00715  * \param chan channel on which to check for hang up
00716  * This function determines if the channel is being requested to be hung up.
00717  * \return Returns 0 if not, or 1 if hang up is requested (including time-out).
00718  */
00719 int ast_check_hangup(struct ast_channel *chan);
00720 
00721 /*! \brief Compare a offset with the settings of when to hang a channel up 
00722  * \param chan channel on which to check for hang up
00723  * \param offset offset in seconds from current time
00724  * \return 1, 0, or -1
00725  * This function compares a offset from current time with the absolute time 
00726  * out on a channel (when to hang up). If the absolute time out on a channel
00727  * is earlier than current time plus the offset, it returns 1, if the two
00728  * time values are equal, it return 0, otherwise, it retturn -1.
00729  */
00730 int ast_channel_cmpwhentohangup(struct ast_channel *chan, time_t offset);
00731 
00732 /*! \brief Set when to hang a channel up 
00733  * \param chan channel on which to check for hang up
00734  * \param offset offset in seconds from current time of when to hang up
00735  * This function sets the absolute time out on a channel (when to hang up).
00736  */
00737 void ast_channel_setwhentohangup(struct ast_channel *chan, time_t offset);
00738 
00739 /*! \brief Answer a ringing call 
00740  * \param chan channel to answer
00741  * This function answers a channel and handles all necessary call
00742  * setup functions.
00743  * \return Returns 0 on success, -1 on failure
00744  */
00745 int ast_answer(struct ast_channel *chan);
00746 
00747 /*! \brief Make a call 
00748  * \param chan which channel to make the call on
00749  * \param addr destination of the call
00750  * \param timeout time to wait on for connect
00751  * Place a call, take no longer than timeout ms. 
00752    \return Returns -1 on failure, 0 on not enough time 
00753    (does not automatically stop ringing), and  
00754    the number of seconds the connect took otherwise.
00755    */
00756 int ast_call(struct ast_channel *chan, char *addr, int timeout);
00757 
00758 /*! \brief Indicates condition of channel 
00759  * \note Indicate a condition such as AST_CONTROL_BUSY, AST_CONTROL_RINGING, or AST_CONTROL_CONGESTION on a channel
00760  * \param chan channel to change the indication
00761  * \param condition which condition to indicate on the channel
00762  * \return Returns 0 on success, -1 on failure
00763  */
00764 int ast_indicate(struct ast_channel *chan, int condition);
00765 
00766 /*! \brief Indicates condition of channel, with payload
00767  * \note Indicate a condition such as AST_CONTROL_HOLD with payload being music on hold class
00768  * \param chan channel to change the indication
00769  * \param condition which condition to indicate on the channel
00770  * \param data pointer to payload data
00771  * \param datalen size of payload data
00772  * \return Returns 0 on success, -1 on failure
00773  */
00774 int ast_indicate_data(struct ast_channel *chan, int condition, const void *data, size_t datalen);
00775 
00776 /* Misc stuff ------------------------------------------------ */
00777 
00778 /*! \brief Wait for input on a channel 
00779  * \param chan channel to wait on
00780  * \param ms length of time to wait on the channel
00781  * Wait for input on a channel for a given # of milliseconds (<0 for indefinite). 
00782   \return Returns < 0 on  failure, 0 if nothing ever arrived, and the # of ms remaining otherwise */
00783 int ast_waitfor(struct ast_channel *chan, int ms);
00784 
00785 /*! \brief Wait for a specied amount of time, looking for hangups 
00786  * \param chan channel to wait for
00787  * \param ms length of time in milliseconds to sleep
00788  * Waits for a specified amount of time, servicing the channel as required.
00789  * \return returns -1 on hangup, otherwise 0.
00790  */
00791 int ast_safe_sleep(struct ast_channel *chan, int ms);
00792 
00793 /*! \brief Wait for a specied amount of time, looking for hangups and a condition argument 
00794  * \param chan channel to wait for
00795  * \param ms length of time in milliseconds to sleep
00796  * \param cond a function pointer for testing continue condition
00797  * \param data argument to be passed to the condition test function
00798  * \return returns -1 on hangup, otherwise 0.
00799  * Waits for a specified amount of time, servicing the channel as required. If cond
00800  * returns 0, this function returns.
00801  */
00802 int ast_safe_sleep_conditional(struct ast_channel *chan, int ms, int (*cond)(void*), void *data );
00803 
00804 /*! \brief Waits for activity on a group of channels 
00805  * \param chan an array of pointers to channels
00806  * \param n number of channels that are to be waited upon
00807  * \param fds an array of fds to wait upon
00808  * \param nfds the number of fds to wait upon
00809  * \param exception exception flag
00810  * \param outfd fd that had activity on it
00811  * \param ms how long the wait was
00812  * Big momma function here.  Wait for activity on any of the n channels, or any of the nfds
00813    file descriptors.
00814    \return Returns the channel with activity, or NULL on error or if an FD
00815    came first.  If the FD came first, it will be returned in outfd, otherwise, outfd
00816    will be -1 */
00817 struct ast_channel *ast_waitfor_nandfds(struct ast_channel **chan, int n, int *fds, int nfds, int *exception, int *outfd, int *ms);
00818 
00819 /*! \brief Waits for input on a group of channels
00820    Wait for input on an array of channels for a given # of milliseconds. 
00821    \return Return channel with activity, or NULL if none has activity.  
00822    \param chan an array of pointers to channels
00823    \param n number of channels that are to be waited upon
00824    \param ms time "ms" is modified in-place, if applicable */
00825 struct ast_channel *ast_waitfor_n(struct ast_channel **chan, int n, int *ms);
00826 
00827 /*! \brief Waits for input on an fd
00828    This version works on fd's only.  Be careful with it. */
00829 int ast_waitfor_n_fd(int *fds, int n, int *ms, int *exception);
00830 
00831 
00832 /*! \brief Reads a frame
00833  * \param chan channel to read a frame from
00834  * \return Returns a frame, or NULL on error.  If it returns NULL, you
00835    best just stop reading frames and assume the channel has been
00836    disconnected. */
00837 struct ast_frame *ast_read(struct ast_channel *chan);
00838 
00839 /*! \brief Reads a frame, returning AST_FRAME_NULL frame if audio. 
00840    \param chan channel to read a frame from
00841    \return  Returns a frame, or NULL on error.  If it returns NULL, you
00842       best just stop reading frames and assume the channel has been
00843       disconnected.  
00844    \note Audio is replaced with AST_FRAME_NULL to avoid 
00845    transcode when the resulting audio is not necessary. */
00846 struct ast_frame *ast_read_noaudio(struct ast_channel *chan);
00847 
00848 /*! \brief Write a frame to a channel 
00849  * This function writes the given frame to the indicated channel.
00850  * \param chan destination channel of the frame
00851  * \param frame frame that will be written
00852  * \return It returns 0 on success, -1 on failure.
00853  */
00854 int ast_write(struct ast_channel *chan, struct ast_frame *frame);
00855 
00856 /*! \brief Write video frame to a channel 
00857  * This function writes the given frame to the indicated channel.
00858  * \param chan destination channel of the frame
00859  * \param frame frame that will be written
00860  * \return It returns 1 on success, 0 if not implemented, and -1 on failure.
00861  */
00862 int ast_write_video(struct ast_channel *chan, struct ast_frame *frame);
00863 
00864 /*! \brief Send empty audio to prime a channel driver */
00865 int ast_prod(struct ast_channel *chan);
00866 
00867 /*! \brief Sets read format on channel chan
00868  * Set read format for channel to whichever component of "format" is best. 
00869  * \param chan channel to change
00870  * \param format format to change to
00871  * \return Returns 0 on success, -1 on failure
00872  */
00873 int ast_set_read_format(struct ast_channel *chan, int format);
00874 
00875 /*! \brief Gets read format from channel chan 
00876  * \param chan channel to get info
00877  * Get read format for channel
00878  * Returns read format
00879  */
00880 static inline int ast_get_read_format(struct ast_channel *chan)
00881 {
00882     return chan->readformat;
00883 }
00884 
00885 /*! Gets write format from channel chan */
00886 /*! 
00887  * \param chan channel to get info
00888  * Get write format for channel
00889  * Returns write format
00890  */
00891 static inline int ast_get_write_format(struct ast_channel *chan)
00892 {
00893     return chan->writeformat;
00894 }
00895 
00896 
00897 /*! \brief Sets write format on channel chan
00898  * Set write format for channel to whichever compoent of "format" is best. 
00899  * \param chan channel to change
00900  * \param format new format for writing
00901  * \return Returns 0 on success, -1 on failure
00902  */
00903 int ast_set_write_format(struct ast_channel *chan, int format);
00904 
00905 /*! \brief Sends text to a channel 
00906  * Write text to a display on a channel
00907  * \param chan channel to act upon
00908  * \param text string of text to send on the channel
00909  * \return Returns 0 on success, -1 on failure
00910  */
00911 int ast_sendtext(struct ast_channel *chan, const char *text);
00912 
00913 /*! \brief Receives a text character from a channel
00914  * \param chan channel to act upon
00915  * \param timeout timeout in milliseconds (0 for infinite wait)
00916  * Read a char of text from a channel
00917  * Returns 0 on success, -1 on failure
00918  */
00919 int ast_recvchar(struct ast_channel *chan, int timeout);
00920 
00921 /*! \brief Send a DTMF digit to a channel
00922  * Send a DTMF digit to a channel.
00923  * \param chan channel to act upon
00924  * \param digit the DTMF digit to send, encoded in ASCII
00925  * \return Returns 0 on success, -1 on failure
00926  */
00927 int ast_senddigit(struct ast_channel *chan, char digit);
00928 
00929 /*! \brief Send a DTMF digit to a channel
00930  * Send a DTMF digit to a channel.
00931  * \param chan channel to act upon
00932  * \param digit the DTMF digit to send, encoded in ASCII
00933  * \return Returns 0 on success, -1 on failure
00934  */
00935 int ast_senddigit_begin(struct ast_channel *chan, char digit);
00936 
00937 /*! \brief Send a DTMF digit to a channel
00938 
00939  * Send a DTMF digit to a channel.
00940  * \param chan channel to act upon
00941  * \param digit the DTMF digit to send, encoded in ASCII
00942  * \return Returns 0 on success, -1 on failure
00943  */
00944 int ast_senddigit_end(struct ast_channel *chan, char digit, unsigned int duration);
00945 
00946 /*! \brief Receives a text string from a channel
00947  * Read a string of text from a channel
00948  * \param chan channel to act upon
00949  * \param timeout timeout in milliseconds (0 for infinite wait)
00950  * \return the received text, or NULL to signify failure.
00951  */
00952 char *ast_recvtext(struct ast_channel *chan, int timeout);
00953 
00954 /*! \brief Browse channels in use
00955  * Browse the channels currently in use 
00956  * \param prev where you want to start in the channel list
00957  * \return Returns the next channel in the list, NULL on end.
00958  *    If it returns a channel, that channel *has been locked*!
00959  */
00960 struct ast_channel *ast_channel_walk_locked(const struct ast_channel *prev);
00961 
00962 /*! \brief Get channel by name (locks channel) */
00963 struct ast_channel *ast_get_channel_by_name_locked(const char *chan);
00964 
00965 /*! \brief Get channel by name prefix (locks channel) */
00966 struct ast_channel *ast_get_channel_by_name_prefix_locked(const char *name, const int namelen);
00967 
00968 /*! \brief Get channel by name prefix (locks channel) */
00969 struct ast_channel *ast_walk_channel_by_name_prefix_locked(const struct ast_channel *chan, const char *name, const int namelen);
00970 
00971 /*! \brief Get channel by exten (and optionally context) and lock it */
00972 struct ast_channel *ast_get_channel_by_exten_locked(const char *exten, const char *context);
00973 
00974 /*! \brief Get next channel by exten (and optionally context) and lock it */
00975 struct ast_channel *ast_walk_channel_by_exten_locked(const struct ast_channel *chan, const char *exten,
00976                        const char *context);
00977 
00978 /*! ! \brief Waits for a digit
00979  * \param c channel to wait for a digit on
00980  * \param ms how many milliseconds to wait
00981  * \return Returns <0 on error, 0 on no entry, and the digit on success. */
00982 int ast_waitfordigit(struct ast_channel *c, int ms);
00983 
00984 /*! \brief Wait for a digit
00985  Same as ast_waitfordigit() with audio fd for outputting read audio and ctrlfd to monitor for reading. 
00986  * \param c channel to wait for a digit on
00987  * \param ms how many milliseconds to wait
00988  * \param audiofd audio file descriptor to write to if audio frames are received
00989  * \param ctrlfd control file descriptor to monitor for reading
00990  * \return Returns 1 if ctrlfd becomes available */
00991 int ast_waitfordigit_full(struct ast_channel *c, int ms, int audiofd, int ctrlfd);
00992 
00993 /*! Reads multiple digits 
00994  * \param c channel to read from
00995  * \param s string to read in to.  Must be at least the size of your length
00996  * \param len how many digits to read (maximum)
00997  * \param timeout how long to timeout between digits
00998  * \param rtimeout timeout to wait on the first digit
00999  * \param enders digits to end the string
01000  * Read in a digit string "s", max length "len", maximum timeout between 
01001    digits "timeout" (-1 for none), terminated by anything in "enders".  Give them rtimeout
01002    for the first digit.  Returns 0 on normal return, or 1 on a timeout.  In the case of
01003    a timeout, any digits that were read before the timeout will still be available in s.  
01004    RETURNS 2 in full version when ctrlfd is available, NOT 1*/
01005 int ast_readstring(struct ast_channel *c, char *s, int len, int timeout, int rtimeout, char *enders);
01006 int ast_readstring_full(struct ast_channel *c, char *s, int len, int timeout, int rtimeout, char *enders, int audiofd, int ctrlfd);
01007 
01008 /*! \brief Report DTMF on channel 0 */
01009 #define AST_BRIDGE_DTMF_CHANNEL_0      (1 << 0)    
01010 /*! \brief Report DTMF on channel 1 */
01011 #define AST_BRIDGE_DTMF_CHANNEL_1      (1 << 1)    
01012 /*! \brief Return all voice frames on channel 0 */
01013 #define AST_BRIDGE_REC_CHANNEL_0    (1 << 2)    
01014 /*! \brief Return all voice frames on channel 1 */
01015 #define AST_BRIDGE_REC_CHANNEL_1    (1 << 3)    
01016 /*! \brief Ignore all signal frames except NULL */
01017 #define AST_BRIDGE_IGNORE_SIGS         (1 << 4)    
01018 
01019 
01020 /*! \brief Makes two channel formats compatible 
01021  * \param c0 first channel to make compatible
01022  * \param c1 other channel to make compatible
01023  * Set two channels to compatible formats -- call before ast_channel_bridge in general .  
01024  * \return Returns 0 on success and -1 if it could not be done */
01025 int ast_channel_make_compatible(struct ast_channel *c0, struct ast_channel *c1);
01026 
01027 /*! Bridge two channels together 
01028  * \param c0 first channel to bridge
01029  * \param c1 second channel to bridge
01030  * \param config config for the channels
01031  * \param fo destination frame(?)
01032  * \param rc destination channel(?)
01033  * Bridge two channels (c0 and c1) together.  If an important frame occurs, we return that frame in
01034    *rf (remember, it could be NULL) and which channel (0 or 1) in rc */
01035 /* int ast_channel_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, struct ast_frame **fo, struct ast_channel **rc); */
01036 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);
01037 
01038 /*! \brief Weird function made for call transfers
01039  * \param original channel to make a copy of
01040  * \param clone copy of the original channel
01041  * This is a very strange and freaky function used primarily for transfer.  Suppose that
01042    "original" and "clone" are two channels in random situations.  This function takes
01043    the guts out of "clone" and puts them into the "original" channel, then alerts the
01044    channel driver of the change, asking it to fixup any private information (like the
01045    p->owner pointer) that is affected by the change.  The physical layer of the original
01046    channel is hung up.  */
01047 int ast_channel_masquerade(struct ast_channel *original, struct ast_channel *clone);
01048 
01049 /*! Gives the string form of a given cause code */
01050 /*! 
01051  * \param state cause to get the description of
01052  * Give a name to a cause code
01053  * Returns the text form of the binary cause code given
01054  */
01055 const char *ast_cause2str(int state) attribute_pure;
01056 
01057 /*! Convert the string form of a cause code to a number */
01058 /*! 
01059  * \param name string form of the cause
01060  * Returns the cause code
01061  */
01062 int ast_str2cause(const char *name) attribute_pure;
01063 
01064 /*! Gives the string form of a given channel state */
01065 /*! 
01066  * \param ast_channel_state state to get the name of
01067  * Give a name to a state 
01068  * Returns the text form of the binary state given
01069  */
01070 char *ast_state2str(enum ast_channel_state);
01071 
01072 /*! Gives the string form of a given transfer capability */
01073 /*!
01074  * \param transfercapability transfercapabilty to get the name of
01075  * Give a name to a transfercapbility
01076  * See above
01077  * Returns the text form of the binary transfer capbility
01078  */
01079 char *ast_transfercapability2str(int transfercapability) attribute_const;
01080 
01081 /* Options: Some low-level drivers may implement "options" allowing fine tuning of the
01082    low level channel.  See frame.h for options.  Note that many channel drivers may support
01083    none or a subset of those features, and you should not count on this if you want your
01084    asterisk application to be portable.  They're mainly useful for tweaking performance */
01085 
01086 /*! Sets an option on a channel */
01087 /*! 
01088  * \param channel channel to set options on
01089  * \param option option to change
01090  * \param data data specific to option
01091  * \param datalen length of the data
01092  * \param block blocking or not
01093  * Set an option on a channel (see frame.h), optionally blocking awaiting the reply 
01094  * Returns 0 on success and -1 on failure
01095  */
01096 int ast_channel_setoption(struct ast_channel *channel, int option, void *data, int datalen, int block);
01097 
01098 /*! Pick the best codec  */
01099 /* Choose the best codec...  Uhhh...   Yah. */
01100 int ast_best_codec(int fmts);
01101 
01102 /*! 
01103  * \brief Pick the best codec from channel nativeformats
01104  * \param channel channel, from that nativeformats used
01105  */
01106 static inline int ast_channel_best_codec(struct ast_channel *channel)
01107 {
01108 #ifndef BUG_4825 
01109    return ast_best_codec(channel->nativeformats);
01110 #else 
01111    return ast_best_codec(channel->nativeformats.audio_bits);
01112 #endif   
01113 }
01114 /*! \brief Get the names of a set of formats
01115  * \param buf a buffer for the output string
01116  * \param size size of buf (bytes)
01117  * \param channel the channel
01118  * Prints a list of readable codec names corresponding to "format".
01119  * ex: for format=AST_FORMAT_GSM|AST_FORMAT_SPEEX|AST_FORMAT_ILBC it will return "0x602 (GSM|SPEEX|ILBC)"
01120  * \return The return value is buf.
01121  */
01122 inline static char * ast_channel_getformatname_multiple(char *buf, size_t size, struct ast_channel *chan)
01123 {
01124    return ast_getformatname_multiple(buf, size, chan->nativeformats);
01125 }
01126 
01127 
01128 static inline const char * ast_channel_getformatname(struct ast_channel *chan)
01129 {
01130 #ifndef BUG_4825 
01131    return chan ? ast_getformatname(chan->nativeformats) : "undefined";
01132 #else 
01133    return chan ? ast_getformatname(chan->nativeformats.audio_bits) : "undefined";
01134 #endif   
01135 }
01136 
01137 static inline void ast_channel_formats_reset(struct ast_channel *channel)
01138 {
01139    int r, w;
01140    r = ast_get_read_format(channel);
01141    w = ast_get_write_format(channel);
01142 
01143    if (option_debug)
01144       ast_log(LOG_DEBUG, "Resetting read to %d and write to %d on channel %s\n", r, w, channel->name);
01145    if (r)
01146       ast_set_read_format(channel, r);
01147    if (w)
01148       ast_set_write_format(channel, w);
01149 }
01150 
01151 /*!
01152  * \brief Set best format, identical to read/write
01153  * \param channel channel, from that nativeformats used and formats set
01154  */
01155 static inline void ast_set_best_format(struct ast_channel *channel)
01156 {
01157     int format = ast_channel_best_codec(channel);
01158     ast_set_read_format(channel, format);
01159     ast_set_write_format(channel, format);
01160 }
01161 
01162 /*! Checks the value of an option */
01163 /*! 
01164  * Query the value of an option, optionally blocking until a reply is received
01165  * Works similarly to setoption except only reads the options.
01166  */
01167 struct ast_frame *ast_channel_queryoption(struct ast_channel *channel, int option, void *data, int *datalen, int block);
01168 
01169 /*! Checks for HTML support on a channel */
01170 /*! Returns 0 if channel does not support HTML or non-zero if it does */
01171 int ast_channel_supports_html(struct ast_channel *channel);
01172 
01173 /*! Sends HTML on given channel */
01174 /*! Send HTML or URL on link.  Returns 0 on success or -1 on failure */
01175 int ast_channel_sendhtml(struct ast_channel *channel, int subclass, const char *data, int datalen);
01176 
01177 /*! Sends a URL on a given link */
01178 /*! Send URL on link.  Returns 0 on success or -1 on failure */
01179 int ast_channel_sendurl(struct ast_channel *channel, const char *url);
01180 
01181 /*! Defers DTMF */
01182 /*! Defer DTMF so that you only read things like hangups and audio.  Returns
01183    non-zero if channel was already DTMF-deferred or 0 if channel is just now
01184    being DTMF-deferred */
01185 int ast_channel_defer_dtmf(struct ast_channel *chan);
01186 
01187 /*! Undeos a defer */
01188 /*! Undo defer.  ast_read will return any dtmf characters that were queued */
01189 void ast_channel_undefer_dtmf(struct ast_channel *chan);
01190 
01191 /*! Initiate system shutdown -- prevents new channels from being allocated.
01192     If "hangup" is non-zero, all existing channels will receive soft
01193      hangups */
01194 void ast_begin_shutdown(int hangup);
01195 
01196 /*! Cancels an existing shutdown and returns to normal operation */
01197 void ast_cancel_shutdown(void);
01198 
01199 /*! Returns number of active/allocated channels */
01200 int ast_active_channels(void);
01201 
01202 /*! Returns non-zero if Asterisk is being shut down */
01203 int ast_shutting_down(void);
01204 
01205 /*! Activate a given generator */
01206 int ast_activate_generator(struct ast_channel *chan, struct ast_generator *gen, void *params);
01207 
01208 /*! Deactive an active generator */
01209 void ast_deactivate_generator(struct ast_channel *chan);
01210 
01211 void ast_set_callerid(struct ast_channel *chan, const char *cidnum, const char *cidname, const char *ani);
01212 
01213 
01214 /*! return a mallocd string with the result of sprintf of the fmt and following args */
01215 char *ast_safe_string_alloc(const char *fmt, ...);
01216 
01217 
01218 
01219 /*! Start a tone going */
01220 int ast_tonepair_start(struct ast_channel *chan, int freq1, int freq2, int duration, int vol);
01221 /*! Stop a tone from playing */
01222 void ast_tonepair_stop(struct ast_channel *chan);
01223 /*! Play a tone pair for a given amount of time */
01224 int ast_tonepair(struct ast_channel *chan, int freq1, int freq2, int duration, int vol);
01225 
01226 /*!
01227  * \brief Automatically service a channel for us... 
01228  *
01229  * \retval 0 success
01230  * \retval -1 failure, or the channel is already being autoserviced
01231  */
01232 int ast_autoservice_start(struct ast_channel *chan);
01233 
01234 /*! 
01235  * \brief Stop servicing a channel for us...  
01236  *
01237  * \retval 0 success
01238  * \retval -1 error, or the channel has been hungup 
01239  */
01240 int ast_autoservice_stop(struct ast_channel *chan);
01241 
01242 /* If built with zaptel optimizations, force a scheduled expiration on the
01243    timer fd, at which point we call the callback function / data */
01244 int ast_settimeout(struct ast_channel *c, int samples, int (*func)(void *data), void *data);
01245 
01246 /*!   \brief Transfer a channel (if supported).  Returns -1 on error, 0 if not supported
01247    and 1 if supported and requested 
01248    \param chan current channel
01249    \param dest destination extension for transfer
01250 */
01251 int ast_transfer(struct ast_channel *chan, char *dest);
01252 
01253 /*!   \brief  Start masquerading a channel
01254    XXX This is a seriously wacked out operation.  We're essentially putting the guts of
01255            the clone channel into the original channel.  Start by killing off the original
01256            channel's backend.   I'm not sure we're going to keep this function, because
01257            while the features are nice, the cost is very high in terms of pure nastiness. XXX
01258    \param chan    Channel to masquerade
01259 */
01260 int ast_do_masquerade(struct ast_channel *chan);
01261 
01262 /*!   \brief Find bridged channel 
01263    \param chan Current channel
01264 */
01265 struct ast_channel *ast_bridged_channel(struct ast_channel *chan);
01266 
01267 /*!
01268   \brief Inherits channel variable from parent to child channel
01269   \param parent Parent channel
01270   \param child Child channel
01271 
01272   Scans all channel variables in the parent channel, looking for those
01273   that should be copied into the child channel.
01274   Variables whose names begin with a single '_' are copied into the
01275   child channel with the prefix removed.
01276   Variables whose names begin with '__' are copied into the child
01277   channel with their names unchanged.
01278 */
01279 void ast_channel_inherit_variables(const struct ast_channel *parent, struct ast_channel *child);
01280 
01281 /*!
01282   \brief adds a list of channel variables to a channel
01283   \param chan the channel
01284   \param vars a linked list of variables
01285 
01286   Variable names can be for a regular channel variable or a dialplan function
01287   that has the ability to be written to.
01288 */
01289 void ast_set_variables(struct ast_channel *chan, struct ast_variable *vars);
01290 
01291 /*!
01292   \brief An opaque 'object' structure use by silence generators on channels.
01293  */
01294 struct ast_silence_generator;
01295 
01296 /*!
01297   \brief Starts a silence generator on the given channel.
01298   \param chan The channel to generate silence on
01299   \return An ast_silence_generator pointer, or NULL if an error occurs
01300 
01301   This function will cause SLINEAR silence to be generated on the supplied
01302   channel until it is disabled; if the channel cannot be put into SLINEAR
01303   mode then the function will fail.
01304 
01305   The pointer returned by this function must be preserved and passed to
01306   ast_channel_stop_silence_generator when you wish to stop the silence
01307   generation.
01308  */
01309 struct ast_silence_generator *ast_channel_start_silence_generator(struct ast_channel *chan);
01310 
01311 /*!
01312   \brief Stops a previously-started silence generator on the given channel.
01313   \param chan The channel to operate on
01314   \param state The ast_silence_generator pointer return by a previous call to
01315   ast_channel_start_silence_generator.
01316   \return nothing
01317 
01318   This function will stop the operating silence generator and return the channel
01319   to its previous write format.
01320  */
01321 void ast_channel_stop_silence_generator(struct ast_channel *chan, struct ast_silence_generator *state);
01322 
01323 /*!
01324   \brief Check if the channel can run in internal timing mode.
01325   \param chan The channel to check
01326   \return boolean
01327 
01328   This function will return 1 if internal timing is enabled and the timing
01329   device is available.
01330  */
01331 int ast_internal_timing_enabled(struct ast_channel *chan);
01332 
01333 /* Misc. functions below */
01334 
01335 /*! \brief if fd is a valid descriptor, set *pfd with the descriptor
01336  * \return Return 1 (not -1!) if added, 0 otherwise (so we can add the
01337  * return value to the index into the array)
01338  */
01339 static inline int ast_add_fd(struct pollfd *pfd, int fd)
01340 {
01341    pfd->fd = fd;
01342    pfd->events = POLLIN | POLLPRI;
01343    return fd >= 0;
01344 }
01345 
01346 /*! \brief Helper function for migrating select to poll */
01347 static inline int ast_fdisset(struct pollfd *pfds, int fd, int max, int *start)
01348 {
01349    int x;
01350    int dummy=0;
01351 
01352    if (fd < 0)
01353       return 0;
01354    if (!start)
01355       start = &dummy;
01356    for (x = *start; x<max; x++)
01357       if (pfds[x].fd == fd) {
01358          if (x == *start)
01359             (*start)++;
01360          return pfds[x].revents;
01361       }
01362    return 0;
01363 }
01364 
01365 #ifdef SOLARIS
01366 static inline void timersub(struct timeval *tvend, struct timeval *tvstart, struct timeval *tvdiff)
01367 {
01368    tvdiff->tv_sec = tvend->tv_sec - tvstart->tv_sec;
01369    tvdiff->tv_usec = tvend->tv_usec - tvstart->tv_usec;
01370    if (tvdiff->tv_usec < 0) {
01371       tvdiff->tv_sec --;
01372       tvdiff->tv_usec += 1000000;
01373    }
01374 
01375 }
01376 #endif
01377 
01378 /*! \brief Waits for activity on a group of channels 
01379  * \param nfds the maximum number of file descriptors in the sets
01380  * \param rfds file descriptors to check for read availability
01381  * \param wfds file descriptors to check for write availability
01382  * \param efds file descriptors to check for exceptions (OOB data)
01383  * \param tvp timeout while waiting for events
01384  * This is the same as a standard select(), except it guarantees the
01385  * behaviour where the passed struct timeval is updated with how much
01386  * time was not slept while waiting for the specified events
01387  */
01388 static inline int ast_select(int nfds, fd_set *rfds, fd_set *wfds, fd_set *efds, struct timeval *tvp)
01389 {
01390 #ifdef __linux__
01391    return select(nfds, rfds, wfds, efds, tvp);
01392 #else
01393    if (tvp) {
01394       struct timeval tv, tvstart, tvend, tvlen;
01395       int res;
01396 
01397       tv = *tvp;
01398       gettimeofday(&tvstart, NULL);
01399       res = select(nfds, rfds, wfds, efds, tvp);
01400       gettimeofday(&tvend, NULL);
01401       timersub(&tvend, &tvstart, &tvlen);
01402       timersub(&tv, &tvlen, tvp);
01403       if (tvp->tv_sec < 0 || (tvp->tv_sec == 0 && tvp->tv_usec < 0)) {
01404          tvp->tv_sec = 0;
01405          tvp->tv_usec = 0;
01406       }
01407       return res;
01408    }
01409    else
01410       return select(nfds, rfds, wfds, efds, NULL);
01411 #endif
01412 }
01413 
01414 #ifdef DO_CRASH
01415 #define CRASH do { fprintf(stderr, "!! Forcing immediate crash a-la abort !!\n"); *((int *)0) = 0; } while(0)
01416 #else
01417 #define CRASH do { } while(0)
01418 #endif
01419 
01420 #define CHECK_BLOCKING(c) do {    \
01421    if (ast_test_flag(c, AST_FLAG_BLOCKING)) {\
01422       if (option_debug) \
01423          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); \
01424       CRASH; \
01425    } else { \
01426       (c)->blocker = pthread_self(); \
01427       (c)->blockproc = __PRETTY_FUNCTION__; \
01428       ast_set_flag(c, AST_FLAG_BLOCKING); \
01429    } } while (0)
01430 
01431 ast_group_t ast_get_group(const char *s);
01432 
01433 /*! \brief print call- and pickup groups into buffer */
01434 char *ast_print_group(char *buf, int buflen, ast_group_t group);
01435 
01436 /*! \brief Convert enum channelreloadreason to text string for manager event
01437    \param reason  Enum channelreloadreason - reason for reload (manager, cli, start etc)
01438 */
01439 const char *channelreloadreason2txt(enum channelreloadreason reason);
01440 
01441 /*! \brief return an ast_variable list of channeltypes */
01442 struct ast_variable *ast_channeltype_list(void);
01443 
01444 /*!
01445   \brief Begin 'whispering' onto a channel
01446   \param chan The channel to whisper onto
01447   \return 0 for success, non-zero for failure
01448 
01449   This function will add a whisper buffer onto a channel and set a flag
01450   causing writes to the channel to reduce the volume level of the written
01451   audio samples, and then to mix in audio from the whisper buffer if it
01452   is available.
01453 
01454   \note Note: This function performs no locking; you must hold the channel's lock before
01455   calling this function.
01456  */
01457 int ast_channel_whisper_start(struct ast_channel *chan);
01458 
01459 /*!
01460   \brief Feed an audio frame into the whisper buffer on a channel
01461   \param chan The channel to whisper onto
01462   \param f The frame to to whisper onto chan
01463   \return 0 for success, non-zero for failure
01464  */
01465 int ast_channel_whisper_feed(struct ast_channel *chan, struct ast_frame *f);
01466 
01467 /*!
01468   \brief Stop 'whispering' onto a channel
01469   \param chan The channel to whisper onto
01470   \return 0 for success, non-zero for failure
01471 
01472   Note: This function performs no locking; you must hold the channel's lock before
01473   calling this function.
01474  */
01475 void ast_channel_whisper_stop(struct ast_channel *chan);
01476 
01477 #if defined(__cplusplus) || defined(c_plusplus)
01478 }
01479 #endif
01480 
01481 #endif /* _ASTERISK_CHANNEL_H */

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