Attempts to "dial out" on all the specified channels (each specified by a type and identifier) simultaneously. The first channel that answers "wins", and all the other outgoing channels are hung up.

* int load_module(void)

• return ast_register_application(app, dial_exec);
  
  

struct localuser {
        struct ast_channel *chan;
        int stillgoing;
        int allowredirect;
        struct localuser *next;
};

\ digit digit digit
    An octal character code. The numeric code is 3 octal digits. For compatibility with other Unix systems, 8 and 9 are accepted as digits: for example, \008 has the value 010, and \009 the value 011. 

* static int dial_exec(struct ast_channel *chan, void *data)

• struct localuser *outgoing=NULL, *tmp;
• peers = strtok(info, "|");
• timeout = strtok(NULL, "|");
• rest = peers;
  • technology1/number1&technology2/number2...
• do {
  • cur = strtok(rest, "&");
  • rest = strtok(NULL, "\128");
    • 앞부분의 technology 와 number 을 cur 에 넣고, 나머지 부분을 rest 에 보관하고자 하는 프로그램이나 문제 있음.
  • tech 와 number 에 technology 와 number 을 assign
  • tmp = malloc(sizeof(struct localuser));
  • tmp->allowredirect = 1;
  • number 이 BYEXTENSION 이면 number = chan->exten; tmp->allowredirect = 0;
    • 없어진 option 인듯함.
  • tmp->chan = ast_request(tech, chan->format, number);
    • channel 을 생성하지 못하면, free(tmp); continue;
  • res = ast_call(tmp->chan, number, 0);
    • call 이 안되면, ast_hangup(tmp->chan); free(tmp); continue;
  • tmp->stillgoing = -1;
  • tmp->next = outgoing;
  • outgoing = tmp; request 와 call 이 성공한 localuser list 를 만듬.
• } while(rest);
• if (timeout) to = atoi(timeout) * 1000;
• else to = -1;
• peer = wait_for_answer(chan, outgoing, &to, &allowredir);
  • outgoing 이 null 인 경우 이전에 조치를 취하는 것이 좋을 듯함.
• if (peer) {
  • hanguptree(outgoing, peer); peer 을 재외한 나머지 channel 을 hangup 시킴.
  • outgoing = NULL;
  • res = bridge_call(chan, peer, allowredir);
  • ast_hangup(peer);
• }
• out:
• hanguptree(outgoing, NULL);
• return res;
  
  

struct chanlist {
        char type[80];
        char description[80];
        int capabilities;
        struct ast_channel * (*requester)(char *type, int format, void *data);
        struct chanlist *next;
} *backends = NULL;

* struct ast_channel *ast_request(char *type, int format, void *data)

• chan = backends;
• type 의 channel 을 찾아, chan->requester 가 있으면 이를 수행시킨다.
  • c = chan->requester(type, format, data);
• return c;
  
  

* int ast_call(struct ast_channel *chan, char *addr, int timeout)

• chan->pvt_call 이 있으면 이를 수행시킨다.
  • res = chan->pvt->call(chan, addr, timeout);
• return res;
  
  

* int ast_hangup(struct ast_channel *chan)

• if (chan->stream) ast_stopstream(chan);
• if (chan->sched) sched_context_destroy(chan->sched);
• if (chan->blocking) Hard hangup called, while fd is blocking
• if (chan->pvt->hangup)
  • res = chan->pvt->hangup(chan);
• if (chan->pvt->pvt) Channel '%s' may not have been hung up properly
• if (chan->trans) Hard hangup called on '%s' while a translator is in place!
• if (chan->pbx) PBX may not have been terminated properly
• if (chan->dnid) free(chan->dnid);
• if (chan->callerid) free(chan->callerid);
• free(chan->pvt);
• free(chan);
• return res;
  
  

* static struct ast_channel *ixj_request(char *type, int format, void *data)

* static int ixj_call(struct ast_channel *ast, char *dest, int timeout)

• p = ast->pvt->pvt;
• channel state 가 AST_STATE_DOWN 도 아니고 AST_STATE_RESERVED 도 아니면
  • return -1;
• ioctl(p->fd, IXJCTL_RING_START);
• ast->state = AST_STATE_RINGING;
• return 0;
  
  

* static int ixj_hangup(struct ast_channel *ast)

• p = ast->pvt->pvt;
• ast->state = AST_STATE_DOWN;
• ioctl(p->fd, IXJCTL_REC_STOP) stop recording
• ioctl(p->fd, IXJCTL_PLAY_STOP) stop playing
• ioctl(p->fd, IXJCTL_RING_STOP) stop ringing
• ioctl(p->fd, IXJCTL_CPT_STOP) stop sounds
• if (ioctl(p->fd, IXJCTL_HOOKSTATE))
  • ioctl(p->fd, IXJCTL_BUSY);
• p->lastformat = -1; p->lastinput = -1; p->ministate = 0; p->obuflen = 0; p->dialtone = 0;
• ast->pvt->pvt = NULL;
• ast->state = AST_STATE_DOWN;
• restart_monitor();
• return 0;
  
  

* static struct ast_channel *wait_for_answer(struct ast_channel *in, struct localuser *outgoing, int *to, int *allowredir)

• to 가 -1 인 경우 매끄럽지 못함.
• tv.tv_sec = *to / 1000; tv.tv_usec = (*to % 1000) * 1000;
• while((tv.tv_sec || tv.tv_usec) && !peer) {
  • FD_SET(in->fd, &rfds); FD_SET(in->fd, &efds);
  • o = outgoing;
  • found = -1; numlines = 0;
  • while(o) {
    • if (o->stillgoing) {
      • CHECK_BLOCKING(o->chan);
      • FD_SET(o->chan->fd, &rfds); FD_SET(o->chan->fd, &efds);
      • if (o->chan->fd > found) found = o->chan->fd;
    • }
    • numlines++;
    • o = o->next;
  • }
    • input channel 과 request, call 이 성공적인 channel 들을 FD_SET 함.
  • if (found<0) {
  • }
  • if (in->fd > found) found = in->fd;
  • if (*to > -1)
    • found = select(found + 1, &rfds, NULL, &efds, &tv);
  • else
    • found = select(found + 1, &rfds, NULL, &efds, NULL);
  • if (found < 0) {
  • }
  • o = outgoing;
  • while(o) {
    • if (o->stillgoing) {
      • o->chan->blocking = 0;
      • if (FD_ISSET(o->chan->fd, &rfds) || FD_ISSET(o->chan->fd, &efds)) {
      • 입력된 데이타가 있으면
        • f = ast_read(o->chan); ixj_read
        • if (f) {
          • AST_CONTROL_ANSWER: ringing 인 상태에서 offhook 이면
            • peer = o->chan;
          • AST_CONTROL_BUSY
            • o->stillgoing = 0;
            • numbusies++;
          • AST_CONTROL_RINGING
          • AST_CONTROL_OFFHOOK
          • ast_frfree(f);
        • } else {
          • o->stillgoing = 0;
        • }
      • }
    • }
    • o = o->next;
  • }
  • if (FD_ISSET(in->fd, &rfds) || FD_ISSET(in->fd, &efds)) {
    • f = ast_read(in);
    • 입력된 데이타가 없거나, hangup 이면
      • *to=-1; return NULL;
  • }
• }
• if (!(tv.tv_sec || tv.tv_usec) && (option_verbose > 2))
  • Nobody picked up in %d ms\n
• *to = 0;
• return peer;
  
  

FD_ZERO(fd_set *fdset) : *fdset의 모든 비트를 지운다.
FD_SET(int fd, fd_set *fdset) : *fdset 중 소켓 fd에 해당하는 비트를 1로 한다.
FD_CLR(int fd, fd_set *fdset) : *fdset 중 소켓 fd에 해당하는 비트를 0으로 한다.
FD_ISSET(int fd, fd_set *fdset) : *fdset 중 소켓 fd에 해당하는 비트가 세트되어 있으면 양수값인 fd를 리턴한다.

select() 는 FD_SET으로 설정된 fd만을 확인합니다. 그리고 확인 결과 read또는 write 준비가 된 fd를 fdset 내에서 '세트'시킵니다. 따라서 select() 함수 직후에 FD_ISSET으로 특정 fd가 'SET'되었는지 확인할 수 있습니다. 

* static int bridge_call(struct ast_channel *chan, struct ast_channel *peer, int allowredirect)

• struct ast_channel *cs3;
• if (chan->state != AST_STATE_UP)
  • if (ast_answer(chan))
    • return -1;
• cs0 = chan;
• cs1 = peer;
• for (/* ever */;;) {
  • who = ast_waitfor_n(cs, 2, &to);
  • f = ast_read(who);
  • if (!f || ((f->frametype == AST_FRAME_CONTROL) && (f->subclass == AST_CONTROL_HANGUP)))
    • return -1;
  • if ((f->frametype == AST_FRAME_VOICE) ||
    (f->frametype == AST_FRAME_DTMF)) {
  • if ((f->frametype == AST_FRAME_DTMF) && (who == peer) && allowredirect) {
  • } else {
    • if (who == chan)
      • ast_write(peer, f);
    • else
      • ast_write(chan, f);
  • }
  • ast_frfree(f);
  • } else
    • ast_frfree(f);
  • cs2 = cs0; cs0 = cs1; cs1 = cs2;
• }
• return res;
  
  

* static int ixj_answer(struct ast_channel *ast)

• ixj_setup(ast);
• ast->rings = 0;
• ast->state = AST_STATE_UP;
• return 0;
  
  

* static int ixj_setup(struct ast_channel *ast)

• p = ast->pvt->pvt;
• ioctl(p->fd, IXJCTL_CPT_STOP);
• if (ast->format & AST_FORMAT_G723_1) {
  • ioctl(p->fd, IXJCTL_REC_STOP);
  • if (p->lastinput != AST_FORMAT_G723_1) {
    • p->lastinput = AST_FORMAT_G723_1;
    • if (ioctl(p->fd, IXJCTL_REC_CODEC, G723_63)) {
      • Failed to set codec to g723.1
      • return -1;
    • }
  • }
• } else if (ast->format & AST_FORMAT_SLINEAR) {
  • ioctl(p->fd, IXJCTL_REC_STOP);
  • if (p->lastinput != AST_FORMAT_SLINEAR) {
    • p->lastinput = AST_FORMAT_SLINEAR;
    • if (ioctl(p->fd, IXJCTL_REC_CODEC, LINEAR16)) {
      • Failed to set codec to signed linear 16
      • return -1;
    • }
  • }
• } else {
  • Can't do format
  • return -1;
• }
• if (ioctl(p->fd, IXJCTL_REC_START)) {
  • Failed to start recording
  • return -1;
• }
• return 0;