Thu Jul 9 13:40:27 2009

Asterisk developer's documentation


chan_local.c

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00001 /*
00002  * Asterisk -- An open source telephony toolkit.
00003  *
00004  * Copyright (C) 1999 - 2005, 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  *
00021  * \author Mark Spencer <markster@digium.com>
00022  *
00023  * \brief Local Proxy Channel
00024  * 
00025  * \ingroup channel_drivers
00026  */
00027 
00028 #include "asterisk.h"
00029 
00030 ASTERISK_FILE_VERSION(__FILE__, "$Revision: 190288 $")
00031 
00032 #include <fcntl.h>
00033 #include <sys/signal.h>
00034 
00035 #include "asterisk/lock.h"
00036 #include "asterisk/channel.h"
00037 #include "asterisk/config.h"
00038 #include "asterisk/module.h"
00039 #include "asterisk/pbx.h"
00040 #include "asterisk/sched.h"
00041 #include "asterisk/io.h"
00042 #include "asterisk/rtp.h"
00043 #include "asterisk/acl.h"
00044 #include "asterisk/callerid.h"
00045 #include "asterisk/file.h"
00046 #include "asterisk/cli.h"
00047 #include "asterisk/app.h"
00048 #include "asterisk/musiconhold.h"
00049 #include "asterisk/manager.h"
00050 #include "asterisk/stringfields.h"
00051 #include "asterisk/devicestate.h"
00052 
00053 static const char tdesc[] = "Local Proxy Channel Driver";
00054 
00055 #define IS_OUTBOUND(a,b) (a == b->chan ? 1 : 0)
00056 
00057 static struct ast_jb_conf g_jb_conf = {
00058    .flags = 0,
00059    .max_size = -1,
00060    .resync_threshold = -1,
00061    .impl = "",
00062 };
00063 
00064 static struct ast_channel *local_request(const char *type, int format, void *data, int *cause);
00065 static int local_digit_begin(struct ast_channel *ast, char digit);
00066 static int local_digit_end(struct ast_channel *ast, char digit, unsigned int duration);
00067 static int local_call(struct ast_channel *ast, char *dest, int timeout);
00068 static int local_hangup(struct ast_channel *ast);
00069 static int local_answer(struct ast_channel *ast);
00070 static struct ast_frame *local_read(struct ast_channel *ast);
00071 static int local_write(struct ast_channel *ast, struct ast_frame *f);
00072 static int local_indicate(struct ast_channel *ast, int condition, const void *data, size_t datalen);
00073 static int local_fixup(struct ast_channel *oldchan, struct ast_channel *newchan);
00074 static int local_sendhtml(struct ast_channel *ast, int subclass, const char *data, int datalen);
00075 static int local_sendtext(struct ast_channel *ast, const char *text);
00076 static int local_devicestate(void *data);
00077 
00078 /* PBX interface structure for channel registration */
00079 static const struct ast_channel_tech local_tech = {
00080    .type = "Local",
00081    .description = tdesc,
00082    .capabilities = -1,
00083    .requester = local_request,
00084    .send_digit_begin = local_digit_begin,
00085    .send_digit_end = local_digit_end,
00086    .call = local_call,
00087    .hangup = local_hangup,
00088    .answer = local_answer,
00089    .read = local_read,
00090    .write = local_write,
00091    .write_video = local_write,
00092    .exception = local_read,
00093    .indicate = local_indicate,
00094    .fixup = local_fixup,
00095    .send_html = local_sendhtml,
00096    .send_text = local_sendtext,
00097    .devicestate = local_devicestate,
00098 };
00099 
00100 struct local_pvt {
00101    ast_mutex_t lock;       /* Channel private lock */
00102    unsigned int flags;                     /* Private flags */
00103    char context[AST_MAX_CONTEXT];      /* Context to call */
00104    char exten[AST_MAX_EXTENSION];      /* Extension to call */
00105    int reqformat;          /* Requested format */
00106    struct ast_jb_conf jb_conf;      /*!< jitterbuffer configuration for this local channel */
00107    struct ast_channel *owner;    /* Master Channel - Bridging happens here */
00108    struct ast_channel *chan;     /* Outbound channel - PBX is run here */
00109    struct ast_module_user *u_owner; /*! reference to keep the module loaded while in use */
00110    struct ast_module_user *u_chan;     /*! reference to keep the module loaded while in use */
00111    AST_LIST_ENTRY(local_pvt) list;     /* Next entity */
00112 };
00113 
00114 #define LOCAL_GLARE_DETECT    (1 << 0) /*!< Detect glare on hangup */
00115 #define LOCAL_CANCEL_QUEUE    (1 << 1) /*!< Cancel queue */
00116 #define LOCAL_ALREADY_MASQED  (1 << 2) /*!< Already masqueraded */
00117 #define LOCAL_LAUNCHED_PBX    (1 << 3) /*!< PBX was launched */
00118 #define LOCAL_NO_OPTIMIZATION (1 << 4) /*!< Do not optimize using masquerading */
00119 
00120 static AST_LIST_HEAD_STATIC(locals, local_pvt);
00121 
00122 /*! \brief Adds devicestate to local channels */
00123 static int local_devicestate(void *data)
00124 {
00125    char *exten = ast_strdupa(data);
00126    char *context = NULL, *opts = NULL;
00127    int res;
00128    struct local_pvt *lp;
00129 
00130    if (!(context = strchr(exten, '@'))) {
00131       ast_log(LOG_WARNING, "Someone used Local/%s somewhere without a @context. This is bad.\n", exten);
00132       return AST_DEVICE_INVALID; 
00133    }
00134 
00135    *context++ = '\0';
00136 
00137    /* Strip options if they exist */
00138    if ((opts = strchr(context, '/')))
00139       *opts = '\0';
00140 
00141    ast_debug(3, "Checking if extension %s@%s exists (devicestate)\n", exten, context);
00142 
00143    res = ast_exists_extension(NULL, context, exten, 1, NULL);
00144    if (!res)      
00145       return AST_DEVICE_INVALID;
00146    
00147    res = AST_DEVICE_NOT_INUSE;
00148    AST_LIST_LOCK(&locals);
00149    AST_LIST_TRAVERSE(&locals, lp, list) {
00150       if (!strcmp(exten, lp->exten) && !strcmp(context, lp->context) && lp->owner) {
00151          res = AST_DEVICE_INUSE;
00152          break;
00153       }
00154    }
00155    AST_LIST_UNLOCK(&locals);
00156 
00157    return res;
00158 }
00159 
00160 /*!
00161  * \note Assumes the pvt is no longer in the pvts list
00162  */
00163 static struct local_pvt *local_pvt_destroy(struct local_pvt *pvt)
00164 {
00165    ast_mutex_destroy(&pvt->lock);
00166    ast_free(pvt);
00167    return NULL;
00168 }
00169 
00170 static int local_queue_frame(struct local_pvt *p, int isoutbound, struct ast_frame *f, 
00171    struct ast_channel *us, int us_locked)
00172 {
00173    struct ast_channel *other = NULL;
00174 
00175    /* Recalculate outbound channel */
00176    other = isoutbound ? p->owner : p->chan;
00177 
00178    if (!other) {
00179       return 0;
00180    }
00181 
00182    /* do not queue frame if generator is on both local channels */
00183    if (us && us->generator && other->generator) {
00184       return 0;
00185    }
00186 
00187    /* Set glare detection */
00188    ast_set_flag(p, LOCAL_GLARE_DETECT);
00189 
00190    /* Ensure that we have both channels locked */
00191    while (other && ast_channel_trylock(other)) {
00192       ast_mutex_unlock(&p->lock);
00193       if (us && us_locked) {
00194          do {
00195             CHANNEL_DEADLOCK_AVOIDANCE(us);
00196          } while (ast_mutex_trylock(&p->lock));
00197       } else {
00198          usleep(1);
00199          ast_mutex_lock(&p->lock);
00200       }
00201       other = isoutbound ? p->owner : p->chan;
00202    }
00203 
00204    /* Since glare detection only occurs within this function, and because
00205     * a pvt flag cannot be set without having the pvt lock, this is the only
00206     * location where we could detect a cancelling of the queue. */
00207    if (ast_test_flag(p, LOCAL_CANCEL_QUEUE)) {
00208       /* We had a glare on the hangup.  Forget all this business,
00209       return and destroy p.  */
00210       ast_mutex_unlock(&p->lock);
00211       p = local_pvt_destroy(p);
00212       return -1;
00213    }
00214 
00215    if (other) {
00216       ast_queue_frame(other, f);
00217       ast_channel_unlock(other);
00218    }
00219 
00220    ast_clear_flag(p, LOCAL_GLARE_DETECT);
00221 
00222    return 0;
00223 }
00224 
00225 static int local_answer(struct ast_channel *ast)
00226 {
00227    struct local_pvt *p = ast->tech_pvt;
00228    int isoutbound;
00229    int res = -1;
00230 
00231    if (!p)
00232       return -1;
00233 
00234    ast_mutex_lock(&p->lock);
00235    isoutbound = IS_OUTBOUND(ast, p);
00236    if (isoutbound) {
00237       /* Pass along answer since somebody answered us */
00238       struct ast_frame answer = { AST_FRAME_CONTROL, AST_CONTROL_ANSWER };
00239       res = local_queue_frame(p, isoutbound, &answer, ast, 1);
00240    } else
00241       ast_log(LOG_WARNING, "Huh?  Local is being asked to answer?\n");
00242    if (!res)
00243       ast_mutex_unlock(&p->lock);
00244    return res;
00245 }
00246 
00247 static void check_bridge(struct local_pvt *p, int isoutbound)
00248 {
00249    struct ast_channel_monitor *tmp;
00250    if (ast_test_flag(p, LOCAL_ALREADY_MASQED) || ast_test_flag(p, LOCAL_NO_OPTIMIZATION) || !p->chan || !p->owner || (p->chan->_bridge != ast_bridged_channel(p->chan)))
00251       return;
00252 
00253    /* only do the masquerade if we are being called on the outbound channel,
00254       if it has been bridged to another channel and if there are no pending
00255       frames on the owner channel (because they would be transferred to the
00256       outbound channel during the masquerade)
00257    */
00258    if (isoutbound && p->chan->_bridge /* Not ast_bridged_channel!  Only go one step! */ && AST_LIST_EMPTY(&p->owner->readq)) {
00259       /* Masquerade bridged channel into owner */
00260       /* Lock everything we need, one by one, and give up if
00261          we can't get everything.  Remember, we'll get another
00262          chance in just a little bit */
00263       if (!ast_channel_trylock(p->chan->_bridge)) {
00264          if (!ast_check_hangup(p->chan->_bridge)) {
00265             if (!ast_channel_trylock(p->owner)) {
00266                if (!ast_check_hangup(p->owner)) {
00267                   if (p->owner->monitor && !p->chan->_bridge->monitor) {
00268                      /* If a local channel is being monitored, we don't want a masquerade
00269                       * to cause the monitor to go away. Since the masquerade swaps the monitors,
00270                       * pre-swapping the monitors before the masquerade will ensure that the monitor
00271                       * ends up where it is expected.
00272                       */
00273                      tmp = p->owner->monitor;
00274                      p->owner->monitor = p->chan->_bridge->monitor;
00275                      p->chan->_bridge->monitor = tmp;
00276                   }
00277                   if (p->chan->audiohooks) {
00278                      struct ast_audiohook_list *audiohooks_swapper;
00279                      audiohooks_swapper = p->chan->audiohooks;
00280                      p->chan->audiohooks = p->owner->audiohooks;
00281                      p->owner->audiohooks = audiohooks_swapper;
00282                   }
00283                   ast_app_group_update(p->chan, p->owner);
00284                   ast_channel_masquerade(p->owner, p->chan->_bridge);
00285                   ast_set_flag(p, LOCAL_ALREADY_MASQED);
00286                }
00287                ast_channel_unlock(p->owner);
00288             }
00289             ast_channel_unlock(p->chan->_bridge);
00290          }
00291       }
00292    /* We only allow masquerading in one 'direction'... it's important to preserve the state
00293       (group variables, etc.) that live on p->chan->_bridge (and were put there by the dialplan)
00294       when the local channels go away.
00295    */
00296 #if 0
00297    } else if (!isoutbound && p->owner && p->owner->_bridge && p->chan && AST_LIST_EMPTY(&p->chan->readq)) {
00298       /* Masquerade bridged channel into chan */
00299       if (!ast_mutex_trylock(&(p->owner->_bridge)->lock)) {
00300          if (!ast_check_hangup(p->owner->_bridge)) {
00301             if (!ast_mutex_trylock(&p->chan->lock)) {
00302                if (!ast_check_hangup(p->chan)) {
00303                   ast_channel_masquerade(p->chan, p->owner->_bridge);
00304                   ast_set_flag(p, LOCAL_ALREADY_MASQED);
00305                }
00306                ast_mutex_unlock(&p->chan->lock);
00307             }
00308          }
00309          ast_mutex_unlock(&(p->owner->_bridge)->lock);
00310       }
00311 #endif
00312    }
00313 }
00314 
00315 static struct ast_frame  *local_read(struct ast_channel *ast)
00316 {
00317    return &ast_null_frame;
00318 }
00319 
00320 static int local_write(struct ast_channel *ast, struct ast_frame *f)
00321 {
00322    struct local_pvt *p = ast->tech_pvt;
00323    int res = -1;
00324    int isoutbound;
00325 
00326    if (!p)
00327       return -1;
00328 
00329    /* Just queue for delivery to the other side */
00330    ast_mutex_lock(&p->lock);
00331    isoutbound = IS_OUTBOUND(ast, p);
00332    if (f && (f->frametype == AST_FRAME_VOICE || f->frametype == AST_FRAME_VIDEO))
00333       check_bridge(p, isoutbound);
00334    if (!ast_test_flag(p, LOCAL_ALREADY_MASQED))
00335       res = local_queue_frame(p, isoutbound, f, ast, 1);
00336    else {
00337       ast_debug(1, "Not posting to queue since already masked on '%s'\n", ast->name);
00338       res = 0;
00339    }
00340    if (!res)
00341       ast_mutex_unlock(&p->lock);
00342    return res;
00343 }
00344 
00345 static int local_fixup(struct ast_channel *oldchan, struct ast_channel *newchan)
00346 {
00347    struct local_pvt *p = newchan->tech_pvt;
00348 
00349    if (!p)
00350       return -1;
00351 
00352    ast_mutex_lock(&p->lock);
00353 
00354    if ((p->owner != oldchan) && (p->chan != oldchan)) {
00355       ast_log(LOG_WARNING, "Old channel wasn't %p but was %p/%p\n", oldchan, p->owner, p->chan);
00356       ast_mutex_unlock(&p->lock);
00357       return -1;
00358    }
00359    if (p->owner == oldchan)
00360       p->owner = newchan;
00361    else
00362       p->chan = newchan;
00363    ast_mutex_unlock(&p->lock);
00364    return 0;
00365 }
00366 
00367 static int local_indicate(struct ast_channel *ast, int condition, const void *data, size_t datalen)
00368 {
00369    struct local_pvt *p = ast->tech_pvt;
00370    int res = 0;
00371    struct ast_frame f = { AST_FRAME_CONTROL, };
00372    int isoutbound;
00373 
00374    if (!p)
00375       return -1;
00376 
00377    /* If this is an MOH hold or unhold, do it on the Local channel versus real channel */
00378    if (condition == AST_CONTROL_HOLD) {
00379       ast_moh_start(ast, data, NULL);
00380    } else if (condition == AST_CONTROL_UNHOLD) {
00381       ast_moh_stop(ast);
00382    } else {
00383       /* Queue up a frame representing the indication as a control frame */
00384       ast_mutex_lock(&p->lock);
00385       isoutbound = IS_OUTBOUND(ast, p);
00386       f.subclass = condition;
00387       f.data = (void*)data;
00388       f.datalen = datalen;
00389       if (!(res = local_queue_frame(p, isoutbound, &f, ast, 1)))
00390          ast_mutex_unlock(&p->lock);
00391    }
00392 
00393    return res;
00394 }
00395 
00396 static int local_digit_begin(struct ast_channel *ast, char digit)
00397 {
00398    struct local_pvt *p = ast->tech_pvt;
00399    int res = -1;
00400    struct ast_frame f = { AST_FRAME_DTMF_BEGIN, };
00401    int isoutbound;
00402 
00403    if (!p)
00404       return -1;
00405 
00406    ast_mutex_lock(&p->lock);
00407    isoutbound = IS_OUTBOUND(ast, p);
00408    f.subclass = digit;
00409    if (!(res = local_queue_frame(p, isoutbound, &f, ast, 0)))
00410       ast_mutex_unlock(&p->lock);
00411 
00412    return res;
00413 }
00414 
00415 static int local_digit_end(struct ast_channel *ast, char digit, unsigned int duration)
00416 {
00417    struct local_pvt *p = ast->tech_pvt;
00418    int res = -1;
00419    struct ast_frame f = { AST_FRAME_DTMF_END, };
00420    int isoutbound;
00421 
00422    if (!p)
00423       return -1;
00424 
00425    ast_mutex_lock(&p->lock);
00426    isoutbound = IS_OUTBOUND(ast, p);
00427    f.subclass = digit;
00428    f.len = duration;
00429    if (!(res = local_queue_frame(p, isoutbound, &f, ast, 0)))
00430       ast_mutex_unlock(&p->lock);
00431 
00432    return res;
00433 }
00434 
00435 static int local_sendtext(struct ast_channel *ast, const char *text)
00436 {
00437    struct local_pvt *p = ast->tech_pvt;
00438    int res = -1;
00439    struct ast_frame f = { AST_FRAME_TEXT, };
00440    int isoutbound;
00441 
00442    if (!p)
00443       return -1;
00444 
00445    ast_mutex_lock(&p->lock);
00446    isoutbound = IS_OUTBOUND(ast, p);
00447    f.data = (char *) text;
00448    f.datalen = strlen(text) + 1;
00449    if (!(res = local_queue_frame(p, isoutbound, &f, ast, 0)))
00450       ast_mutex_unlock(&p->lock);
00451    return res;
00452 }
00453 
00454 static int local_sendhtml(struct ast_channel *ast, int subclass, const char *data, int datalen)
00455 {
00456    struct local_pvt *p = ast->tech_pvt;
00457    int res = -1;
00458    struct ast_frame f = { AST_FRAME_HTML, };
00459    int isoutbound;
00460 
00461    if (!p)
00462       return -1;
00463    
00464    ast_mutex_lock(&p->lock);
00465    isoutbound = IS_OUTBOUND(ast, p);
00466    f.subclass = subclass;
00467    f.data = (char *)data;
00468    f.datalen = datalen;
00469    if (!(res = local_queue_frame(p, isoutbound, &f, ast, 0)))
00470       ast_mutex_unlock(&p->lock);
00471    return res;
00472 }
00473 
00474 /*! \brief Initiate new call, part of PBX interface 
00475  *    dest is the dial string */
00476 static int local_call(struct ast_channel *ast, char *dest, int timeout)
00477 {
00478    struct local_pvt *p = ast->tech_pvt;
00479    int res;
00480    struct ast_var_t *varptr = NULL, *new;
00481    size_t len, namelen;
00482 
00483    if (!p)
00484       return -1;
00485    
00486    ast_mutex_lock(&p->lock);
00487 
00488    /*
00489     * Note that cid_num and cid_name aren't passed in the ast_channel_alloc
00490     * call, so it's done here instead.
00491     */
00492    p->chan->cid.cid_dnid = ast_strdup(p->owner->cid.cid_dnid);
00493    p->chan->cid.cid_num = ast_strdup(p->owner->cid.cid_num);
00494    p->chan->cid.cid_name = ast_strdup(p->owner->cid.cid_name);
00495    p->chan->cid.cid_rdnis = ast_strdup(p->owner->cid.cid_rdnis);
00496    p->chan->cid.cid_ani = ast_strdup(p->owner->cid.cid_ani);
00497    p->chan->cid.cid_pres = p->owner->cid.cid_pres;
00498    p->chan->cid.cid_ani2 = p->owner->cid.cid_ani2;
00499    p->chan->cid.cid_ton = p->owner->cid.cid_ton;
00500    p->chan->cid.cid_tns = p->owner->cid.cid_tns;
00501    ast_string_field_set(p->chan, language, p->owner->language);
00502    ast_string_field_set(p->chan, accountcode, p->owner->accountcode);
00503    ast_string_field_set(p->chan, musicclass, p->owner->musicclass);
00504    ast_cdr_update(p->chan);
00505    p->chan->cdrflags = p->owner->cdrflags;
00506 
00507    /* copy the channel variables from the incoming channel to the outgoing channel */
00508    /* Note that due to certain assumptions, they MUST be in the same order */
00509    AST_LIST_TRAVERSE(&p->owner->varshead, varptr, entries) {
00510       namelen = strlen(varptr->name);
00511       len = sizeof(struct ast_var_t) + namelen + strlen(varptr->value) + 2;
00512       if ((new = ast_calloc(1, len))) {
00513          memcpy(new, varptr, len);
00514          new->value = &(new->name[0]) + namelen + 1;
00515          AST_LIST_INSERT_TAIL(&p->chan->varshead, new, entries);
00516       }
00517    }
00518    ast_channel_datastore_inherit(p->owner, p->chan);
00519 
00520    /* Start switch on sub channel */
00521    if (!(res = ast_pbx_start(p->chan)))
00522       ast_set_flag(p, LOCAL_LAUNCHED_PBX);
00523 
00524    ast_mutex_unlock(&p->lock);
00525    return res;
00526 }
00527 
00528 /*! \brief Hangup a call through the local proxy channel */
00529 static int local_hangup(struct ast_channel *ast)
00530 {
00531    struct local_pvt *p = ast->tech_pvt;
00532    int isoutbound;
00533    struct ast_frame f = { AST_FRAME_CONTROL, AST_CONTROL_HANGUP };
00534    struct ast_channel *ochan = NULL;
00535    int glaredetect = 0, res = 0;
00536 
00537    if (!p)
00538       return -1;
00539 
00540    ast_mutex_lock(&p->lock);
00541 
00542    if (p->chan && ast_test_flag(ast, AST_FLAG_ANSWERED_ELSEWHERE)) 
00543       ast_set_flag(p->chan, AST_FLAG_ANSWERED_ELSEWHERE);
00544    isoutbound = IS_OUTBOUND(ast, p);
00545    if (isoutbound) {
00546       const char *status = pbx_builtin_getvar_helper(p->chan, "DIALSTATUS");
00547       if ((status) && (p->owner)) {
00548          /* Deadlock avoidance */
00549          while (p->owner && ast_channel_trylock(p->owner)) {
00550             ast_mutex_unlock(&p->lock);
00551             if (ast) {
00552                ast_channel_unlock(ast);
00553             }
00554             usleep(1);
00555             if (ast) {
00556                ast_channel_lock(ast);
00557             }
00558             ast_mutex_lock(&p->lock);
00559          }
00560          if (p->owner) {
00561             pbx_builtin_setvar_helper(p->owner, "CHANLOCALSTATUS", status);
00562             ast_channel_unlock(p->owner);
00563          }
00564       }
00565       p->chan = NULL;
00566       ast_clear_flag(p, LOCAL_LAUNCHED_PBX);
00567       ast_module_user_remove(p->u_chan);
00568    } else {
00569       p->owner = NULL;
00570       ast_module_user_remove(p->u_owner);
00571       while (p->chan && ast_channel_trylock(p->chan)) {
00572          DEADLOCK_AVOIDANCE(&p->lock);
00573       }
00574       if (p->chan) {
00575          ast_queue_hangup(p->chan);
00576          ast_channel_unlock(p->chan);
00577       }
00578    }
00579    
00580    ast->tech_pvt = NULL;
00581    
00582    if (!p->owner && !p->chan) {
00583       /* Okay, done with the private part now, too. */
00584       glaredetect = ast_test_flag(p, LOCAL_GLARE_DETECT);
00585       /* If we have a queue holding, don't actually destroy p yet, but
00586          let local_queue do it. */
00587       if (glaredetect)
00588          ast_set_flag(p, LOCAL_CANCEL_QUEUE);
00589       /* Remove from list */
00590       AST_LIST_LOCK(&locals);
00591       AST_LIST_REMOVE(&locals, p, list);
00592       AST_LIST_UNLOCK(&locals);
00593       ast_mutex_unlock(&p->lock);
00594       /* And destroy */
00595       if (!glaredetect) {
00596          p = local_pvt_destroy(p);
00597       }
00598       return 0;
00599    }
00600    if (p->chan && !ast_test_flag(p, LOCAL_LAUNCHED_PBX))
00601       /* Need to actually hangup since there is no PBX */
00602       ochan = p->chan;
00603    else
00604       res = local_queue_frame(p, isoutbound, &f, NULL, 1);
00605    if (!res)
00606       ast_mutex_unlock(&p->lock);
00607    if (ochan)
00608       ast_hangup(ochan);
00609    return 0;
00610 }
00611 
00612 /*! \brief Create a call structure */
00613 static struct local_pvt *local_alloc(const char *data, int format)
00614 {
00615    struct local_pvt *tmp = NULL;
00616    char *c = NULL, *opts = NULL;
00617 
00618    if (!(tmp = ast_calloc(1, sizeof(*tmp))))
00619       return NULL;
00620 
00621    /* Initialize private structure information */
00622    ast_mutex_init(&tmp->lock);
00623    ast_copy_string(tmp->exten, data, sizeof(tmp->exten));
00624 
00625    memcpy(&tmp->jb_conf, &g_jb_conf, sizeof(tmp->jb_conf));
00626 
00627    /* Look for options */
00628    if ((opts = strchr(tmp->exten, '/'))) {
00629       *opts++ = '\0';
00630       if (strchr(opts, 'n'))
00631          ast_set_flag(tmp, LOCAL_NO_OPTIMIZATION);
00632       if (strchr(opts, 'j')) {
00633          if (ast_test_flag(tmp, LOCAL_NO_OPTIMIZATION))
00634             ast_set_flag(&tmp->jb_conf, AST_JB_ENABLED);
00635          else {
00636             ast_log(LOG_ERROR, "You must use the 'n' option for chan_local "
00637                "to use the 'j' option to enable the jitterbuffer\n");
00638          }
00639       }
00640    }
00641 
00642    /* Look for a context */
00643    if ((c = strchr(tmp->exten, '@')))
00644       *c++ = '\0';
00645 
00646    ast_copy_string(tmp->context, c ? c : "default", sizeof(tmp->context));
00647 
00648    tmp->reqformat = format;
00649 
00650    if (!ast_exists_extension(NULL, tmp->context, tmp->exten, 1, NULL)) {
00651       ast_log(LOG_NOTICE, "No such extension/context %s@%s creating local channel\n", tmp->exten, tmp->context);
00652       tmp = local_pvt_destroy(tmp);
00653    } else {
00654       /* Add to list */
00655       AST_LIST_LOCK(&locals);
00656       AST_LIST_INSERT_HEAD(&locals, tmp, list);
00657       AST_LIST_UNLOCK(&locals);
00658    }
00659    
00660    return tmp;
00661 }
00662 
00663 /*! \brief Start new local channel */
00664 static struct ast_channel *local_new(struct local_pvt *p, int state)
00665 {
00666    struct ast_channel *tmp = NULL, *tmp2 = NULL;
00667    int randnum = ast_random() & 0xffff, fmt = 0;
00668    const char *t;
00669    int ama;
00670 
00671    /* Allocate two new Asterisk channels */
00672    /* safe accountcode */
00673    if (p->owner && p->owner->accountcode)
00674       t = p->owner->accountcode;
00675    else
00676       t = "";
00677 
00678    if (p->owner)
00679       ama = p->owner->amaflags;
00680    else
00681       ama = 0;
00682    if (!(tmp = ast_channel_alloc(1, state, 0, 0, t, p->exten, p->context, ama, "Local/%s@%s-%04x;1", p->exten, p->context, randnum)) 
00683          || !(tmp2 = ast_channel_alloc(1, AST_STATE_RING, 0, 0, t, p->exten, p->context, ama, "Local/%s@%s-%04x;2", p->exten, p->context, randnum))) {
00684       if (tmp)
00685          ast_channel_free(tmp);
00686       if (tmp2)
00687          ast_channel_free(tmp2);
00688       ast_log(LOG_WARNING, "Unable to allocate channel structure(s)\n");
00689       return NULL;
00690    } 
00691 
00692    tmp2->tech = tmp->tech = &local_tech;
00693 
00694    tmp->nativeformats = p->reqformat;
00695    tmp2->nativeformats = p->reqformat;
00696 
00697    /* Determine our read/write format and set it on each channel */
00698    fmt = ast_best_codec(p->reqformat);
00699    tmp->writeformat = fmt;
00700    tmp2->writeformat = fmt;
00701    tmp->rawwriteformat = fmt;
00702    tmp2->rawwriteformat = fmt;
00703    tmp->readformat = fmt;
00704    tmp2->readformat = fmt;
00705    tmp->rawreadformat = fmt;
00706    tmp2->rawreadformat = fmt;
00707 
00708    tmp->tech_pvt = p;
00709    tmp2->tech_pvt = p;
00710 
00711    p->owner = tmp;
00712    p->chan = tmp2;
00713    p->u_owner = ast_module_user_add(p->owner);
00714    p->u_chan = ast_module_user_add(p->chan);
00715 
00716    ast_copy_string(tmp->context, p->context, sizeof(tmp->context));
00717    ast_copy_string(tmp2->context, p->context, sizeof(tmp2->context));
00718    ast_copy_string(tmp2->exten, p->exten, sizeof(tmp->exten));
00719    tmp->priority = 1;
00720    tmp2->priority = 1;
00721 
00722    ast_jb_configure(tmp, &p->jb_conf);
00723 
00724    return tmp;
00725 }
00726 
00727 /*! \brief Part of PBX interface */
00728 static struct ast_channel *local_request(const char *type, int format, void *data, int *cause)
00729 {
00730    struct local_pvt *p = NULL;
00731    struct ast_channel *chan = NULL;
00732 
00733    /* Allocate a new private structure and then Asterisk channel */
00734    if ((p = local_alloc(data, format))) {
00735       if (!(chan = local_new(p, AST_STATE_DOWN))) {
00736          AST_LIST_LOCK(&locals);
00737          AST_LIST_REMOVE(&locals, p, list);
00738          AST_LIST_UNLOCK(&locals);
00739          p = local_pvt_destroy(p);
00740       }
00741    }
00742 
00743    return chan;
00744 }
00745 
00746 /*! \brief CLI command "local show channels" */
00747 static char *locals_show(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
00748 {
00749    struct local_pvt *p = NULL;
00750 
00751    switch (cmd) {
00752    case CLI_INIT:
00753       e->command = "local show channels";
00754       e->usage =
00755          "Usage: local show channels\n"
00756          "       Provides summary information on active local proxy channels.\n";
00757       return NULL;
00758    case CLI_GENERATE:
00759       return NULL;
00760    }
00761 
00762    if (a->argc != 3)
00763       return CLI_SHOWUSAGE;
00764 
00765    AST_LIST_LOCK(&locals);
00766    if (!AST_LIST_EMPTY(&locals)) {
00767       AST_LIST_TRAVERSE(&locals, p, list) {
00768          ast_mutex_lock(&p->lock);
00769          ast_cli(a->fd, "%s -- %s@%s\n", p->owner ? p->owner->name : "<unowned>", p->exten, p->context);
00770          ast_mutex_unlock(&p->lock);
00771       }
00772    } else
00773       ast_cli(a->fd, "No local channels in use\n");
00774    AST_LIST_UNLOCK(&locals);
00775 
00776    return CLI_SUCCESS;
00777 }
00778 
00779 static struct ast_cli_entry cli_local[] = {
00780    AST_CLI_DEFINE(locals_show, "List status of local channels"),
00781 };
00782 
00783 /*! \brief Load module into PBX, register channel */
00784 static int load_module(void)
00785 {
00786    /* Make sure we can register our channel type */
00787    if (ast_channel_register(&local_tech)) {
00788       ast_log(LOG_ERROR, "Unable to register channel class 'Local'\n");
00789       return AST_MODULE_LOAD_FAILURE;
00790    }
00791    ast_cli_register_multiple(cli_local, sizeof(cli_local) / sizeof(struct ast_cli_entry));
00792    return AST_MODULE_LOAD_SUCCESS;
00793 }
00794 
00795 /*! \brief Unload the local proxy channel from Asterisk */
00796 static int unload_module(void)
00797 {
00798    struct local_pvt *p = NULL;
00799 
00800    /* First, take us out of the channel loop */
00801    ast_cli_unregister_multiple(cli_local, sizeof(cli_local) / sizeof(struct ast_cli_entry));
00802    ast_channel_unregister(&local_tech);
00803    if (!AST_LIST_LOCK(&locals)) {
00804       /* Hangup all interfaces if they have an owner */
00805       AST_LIST_TRAVERSE(&locals, p, list) {
00806          if (p->owner)
00807             ast_softhangup(p->owner, AST_SOFTHANGUP_APPUNLOAD);
00808       }
00809       AST_LIST_UNLOCK(&locals);
00810    } else {
00811       ast_log(LOG_WARNING, "Unable to lock the monitor\n");
00812       return -1;
00813    }     
00814    return 0;
00815 }
00816 
00817 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Local Proxy Channel (Note: used internally by other modules)");

Generated on Thu Jul 9 13:40:27 2009 for Asterisk - the Open Source PBX by  doxygen 1.4.7