ecabbd90e564ab1e11cede2f1d926cb026de5522
[asterisk/asterisk.git] / res / res_fax.c
1 /*
2  * Asterisk -- An open source telephony toolkit.
3  *
4  * Copyright (C) 2008-2009, Digium, Inc.
5  *
6  * Dwayne M. Hubbard <dhubbard@digium.com>
7  * Kevin P. Fleming <kpfleming@digium.com>
8  *
9  * See http://www.asterisk.org for more information about
10  * the Asterisk project. Please do not directly contact
11  * any of the maintainers of this project for assistance;
12  * the project provides a web site, mailing lists and IRC
13  * channels for your use.
14  *
15  * This program is free software, distributed under the terms of
16  * the GNU General Public License Version 2. See the LICENSE file
17  * at the top of the source tree.
18  */
19
20 /*** MODULEINFO
21         <conflict>app_fax</conflict>
22 ***/
23
24 /*! \file
25  *
26  * \brief Generic FAX Resource for FAX technology resource modules
27  *
28  * \author Dwayne M. Hubbard <dhubbard@digium.com>
29  * \author Kevin P. Fleming <kpfleming@digium.com>
30  * 
31  * A generic FAX resource module that provides SendFAX and ReceiveFAX applications.
32  * This module requires FAX technology modules, like res_fax_spandsp, to register with it
33  * so it can use the technology modules to perform the actual FAX transmissions.
34  * \ingroup applications
35  */
36
37 #include "asterisk.h"
38
39 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
40
41 #include "asterisk/io.h"
42 #include "asterisk/file.h"
43 #include "asterisk/logger.h"
44 #include "asterisk/module.h"
45 #include "asterisk/app.h"
46 #include "asterisk/lock.h"
47 #include "asterisk/options.h"
48 #include "asterisk/strings.h"
49 #include "asterisk/cli.h"
50 #include "asterisk/utils.h"
51 #include "asterisk/config.h"
52 #include "asterisk/astobj2.h"
53 #include "asterisk/res_fax.h"
54 #include "asterisk/file.h"
55 #include "asterisk/channel.h"
56 #include "asterisk/pbx.h"
57 #include "asterisk/manager.h"
58 #include "asterisk/dsp.h"
59 #include "asterisk/indications.h"
60 #include "asterisk/ast_version.h"
61
62 /*** DOCUMENTATION
63         <application name="ReceiveFax" language="en_US">
64                 <synopsis>
65                         Receive a FAX and save as a TIFF/F file.
66                 </synopsis>
67                 <syntax>
68                         <parameter name="filename" required="true" />
69                         <parameter name="options">
70                                 <optionlist>
71                                         <option name="d">
72                                                 <para>Enable FAX debugging.</para>
73                                         </option>
74                                         <option name="f">
75                                                 <para>Allow audio fallback FAX transfer on T.38 capable channels.</para>
76                                         </option>
77                                         <option name="s">
78                                                 <para>Send progress Manager events (overrides statusevents setting in res_fax.conf).</para>
79                                         </option>
80                                 </optionlist>
81                         </parameter>
82                 </syntax>
83                 <description>
84                         <para>This application is provided by res_fax, which is a FAX technology agnostic module
85                         that utilizes FAX technology resource modules to complete a FAX transmission.</para>
86                         <para>Session arguments can be set by the FAXOPT function and to check results of the ReceiveFax() application.</para>
87                 </description>
88                 <see-also>
89                         <ref type="function">FAXOPT</ref>
90                 </see-also>
91         </application>
92         <application name="SendeFax" language="en_US">
93                 <synopsis>
94                         Sends a specified TIFF/F file as a FAX.
95                 </synopsis>
96                 <syntax>
97                         <parameter name="filename" required="true" argsep="&amp;">
98                                 <argument name="filename2" multiple="true">
99                                         <para>TIFF file to send as a FAX.</para>
100                                 </argument>
101                         </parameter>
102                         <parameter name="options">
103                                 <optionlist>
104                                         <option name="d">
105                                                 <para>Enable FAX debugging.</para>
106                                         </option>
107                                         <option name="f">
108                                                 <para>Allow audio fallback FAX transfer on T.38 capable channels.</para>
109                                         </option>
110                                         <option name="s">
111                                                 <para>Send progress Manager events (overrides statusevents setting in res_fax.conf).</para>
112                                         </option>
113                                         <option name="z">
114                                                 <para>Initiate a T.38 reinvite on the channel if the remote end does not.</para>
115                                         </option>
116                                 </optionlist>
117                         </parameter>
118                 </syntax>
119                 <description>
120                         <para>This application is provided by res_fax, which is a FAX technology agnostic module
121                         that utilizes FAX technology resource modules to complete a FAX transmission.</para>
122                         <para>Session arguments can be set by the FAXOPT function and to check results of the SendFax() application.</para>
123                 </description>
124                 <see-also>
125                         <ref type="function">FAXOPT</ref>
126                 </see-also>
127         </application>
128         <function name="FAXOPT" language="en_US">
129                 <synopsis>
130                         Gets/sets various pieces of information about a fax session.
131                 </synopsis>
132                 <syntax>
133                         <parameter name="item" required="true">
134                                 <enumlist>
135                                         <enum name="ecm">
136                                                 <para>R/W Error Correction Mode (ECM) enable with 'yes', disable with 'no'.</para>
137                                         </enum>
138                                         <enum name="error">
139                                                 <para>R/O FAX transmission error code upon failure.</para>
140                                         </enum>
141                                         <enum name="filename">
142                                                 <para>R/O Filename of the first file of the FAX transmission.</para>
143                                         </enum>
144                                         <enum name="filenames">
145                                                 <para>R/O Filenames of all of the files in the FAX transmission (comma separated).</para>
146                                         </enum>
147                                         <enum name="headerinfo">
148                                                 <para>R/W FAX header information.</para>
149                                         </enum>
150                                         <enum name="localstationid">
151                                                 <para>R/W Local Station Identification.</para>
152                                         </enum>
153                                         <enum name="minrate">
154                                                 <para>R/W Minimum transfer rate set before transmission.</para>
155                                         </enum>
156                                         <enum name="maxrate">
157                                                 <para>R/W Maximum transfer rate set before transmission.</para>
158                                         </enum>
159                                         <enum name="modem">
160                                                 <para>R/W Modem type (v17/v27/v29).</para>
161                                         </enum>
162                                         <enum name="pages">
163                                                 <para>R/O Number of pages transferred.</para>
164                                         </enum>
165                                         <enum name="rate">
166                                                 <para>R/O Negotiated transmission rate.</para>
167                                         </enum>
168                                         <enum name="remotestationid">
169                                                 <para>R/O Remote Station Identification after transmission.</para>
170                                         </enum>
171                                         <enum name="resolution">
172                                                 <para>R/O Negotiated image resolution after transmission.</para>
173                                         </enum>
174                                         <enum name="sessionid">
175                                                 <para>R/O Session ID of the FAX transmission.</para>
176                                         </enum>
177                                         <enum name="status">
178                                                 <para>R/O Result Status of the FAX transmission.</para>
179                                         </enum>
180                                         <enum name="statusstr">
181                                                 <para>R/O Verbose Result Status of the FAX transmission.</para>
182                                         </enum>
183                                 </enumlist>
184                         </parameter>
185                 </syntax>
186                 <description>
187                         <para>FAXOPT can be used to override the settings for a FAX session listed in <filename>res_fax.conf</filename>,
188                         it can also be used to retreive information about a FAX session that has finished eg. pages/status.</para>
189                 </description>
190                 <see-also>
191                         <ref type="application">ReceiveFax</ref>
192                         <ref type="application">SendFax</ref>
193                 </see-also>
194         </function>
195 ***/
196
197 static const char app_receivefax[] = "ReceiveFAX";
198 static const char app_sendfax[] = "SendFAX";
199
200 struct debug_info_history {
201         unsigned int consec_frames;
202         unsigned int consec_ms;
203         unsigned char silence;
204 };
205
206 struct ast_fax_debug_info {
207         struct timeval base_tv;
208         struct debug_info_history c2s, s2c;
209         struct ast_dsp *dsp;
210 };
211
212 static int fax_logger_level = -1;
213
214 /*! \brief maximum buckets for res_fax ao2 containers */
215 #define FAX_MAXBUCKETS 10
216
217 #define RES_FAX_TIMEOUT 10000
218
219 /*! \brief The faxregistry is used to manage information and statistics for all FAX sessions. */
220 static struct {
221         /*! The number of active FAX sessions */
222         int active_sessions;
223         /*! active sessions are astobj2 objects */
224         struct ao2_container *container;
225         /*! Total number of Tx FAX attempts */
226         int fax_tx_attempts;
227         /*! Total number of Rx FAX attempts */
228         int fax_rx_attempts;
229         /*! Number of successful FAX transmissions */
230         int fax_complete;
231         /*! Number of failed FAX transmissions */
232         int fax_failures;
233         /*! the next unique session name */
234         int nextsessionname;
235 } faxregistry;
236
237 /*! \brief registered FAX technology modules are put into this list */
238 struct fax_module {
239         const struct ast_fax_tech *tech;
240         AST_RWLIST_ENTRY(fax_module) list;
241 };
242 static AST_RWLIST_HEAD_STATIC(faxmodules, fax_module);
243
244 #define RES_FAX_MINRATE 2400
245 #define RES_FAX_MAXRATE 14400
246 #define RES_FAX_STATUSEVENTS 0
247 #define RES_FAX_MODEM (AST_FAX_MODEM_V17 | AST_FAX_MODEM_V27 | AST_FAX_MODEM_V29)
248
249 static struct {
250         enum ast_fax_modems modems;
251         uint32_t statusevents:1;
252         uint32_t ecm:1;
253         unsigned int minrate;   
254         unsigned int maxrate;
255 } general_options;
256
257 static const char *config = "res_fax.conf";
258
259 static int global_fax_debug = 0;
260
261 enum {
262         OPT_CALLEDMODE  = (1 << 0),
263         OPT_CALLERMODE  = (1 << 1),
264         OPT_DEBUG       = (1 << 2),
265         OPT_STATUS      = (1 << 3),
266         OPT_ALLOWAUDIO  = (1 << 5),
267         OPT_REQUEST_T38 = (1 << 6),
268 };
269
270 AST_APP_OPTIONS(fax_exec_options, BEGIN_OPTIONS
271         AST_APP_OPTION('a', OPT_CALLEDMODE),
272         AST_APP_OPTION('c', OPT_CALLERMODE),
273         AST_APP_OPTION('d', OPT_DEBUG),
274         AST_APP_OPTION('f', OPT_ALLOWAUDIO),
275         AST_APP_OPTION('s', OPT_STATUS),
276         AST_APP_OPTION('z', OPT_REQUEST_T38),
277 END_OPTIONS);
278
279 struct manager_event_info {
280         char context[AST_MAX_CONTEXT];
281         char exten[AST_MAX_EXTENSION];
282         char cid[128];
283 };
284
285 static void debug_check_frame_for_silence(struct ast_fax_session *s, unsigned int c2s, struct ast_frame *frame)
286 {       
287         struct debug_info_history *history = c2s ? &s->debug_info->c2s : &s->debug_info->s2c;
288         int dspsilence;
289         unsigned int last_consec_frames, last_consec_ms;
290         unsigned char wassil;
291         struct timeval diff;
292
293         diff = ast_tvsub(ast_tvnow(), s->debug_info->base_tv);
294
295         ast_dsp_reset(s->debug_info->dsp);
296         ast_dsp_silence(s->debug_info->dsp, frame, &dspsilence);
297
298         wassil = history->silence;
299         history->silence = (dspsilence != 0) ? 1 : 0;
300         if (history->silence != wassil) {
301                 last_consec_frames = history->consec_frames;
302                 last_consec_ms = history->consec_ms;
303                 history->consec_frames = 0;
304                 history->consec_ms = 0;
305
306                 if ((last_consec_frames != 0)) {
307                         ast_verb(6, "Channel '%s' fax session '%d', [ %.3ld.%.6ld ], %s sent %d frames (%d ms) of %s.\n",
308                                  s->channame, s->id, (long) diff.tv_sec, (long int) diff.tv_usec,
309                                  (c2s) ? "channel" : "stack", last_consec_frames, last_consec_ms,
310                                  (wassil) ? "silence" : "energy");
311                 }
312         }
313
314         history->consec_frames++;
315         history->consec_ms += (frame->samples / 8);
316 }
317
318 static void destroy_callback(void *data) 
319 {
320         if (data) {
321                 ao2_ref(data, -1);
322         }
323 }
324
325 static const struct ast_datastore_info fax_datastore = {
326         .type = "res_fax",
327         .destroy = destroy_callback,
328 };
329
330 /*! \brief returns a reference counted pointer to a fax datastore, if it exists */
331 static struct ast_fax_session_details *find_details(struct ast_channel *chan)
332 {
333         struct ast_fax_session_details *details;
334         struct ast_datastore *datastore;
335
336         ast_channel_lock(chan); 
337         if (!(datastore = ast_channel_datastore_find(chan, &fax_datastore, NULL))) {
338                 ast_channel_unlock(chan);       
339                 return NULL;
340         }
341         if (!(details = datastore->data)) {
342                 ast_log(LOG_WARNING, "Huh?  channel '%s' has a FAX datastore without data!\n", chan->name);
343                 ast_channel_unlock(chan);
344                 return NULL;
345         }
346         ao2_ref(details, 1);    
347         ast_channel_unlock(chan);       
348
349         return details;
350 }
351
352 /*! \brief destroy a FAX session details structure */
353 static void destroy_session_details(void *details)
354 {
355         struct ast_fax_session_details *d = details;
356         struct ast_fax_document *doc;
357         
358         while ((doc = AST_LIST_REMOVE_HEAD(&d->documents, next))) {
359                 ast_free(doc);
360         }
361         ast_string_field_free_memory(d);        
362 }
363
364 /*! \brief create a FAX session details structure */
365 static struct ast_fax_session_details *session_details_new(void)
366 {
367         struct ast_fax_session_details *d;
368
369         if (!(d = ao2_alloc(sizeof(*d), destroy_session_details))) {
370                 return NULL;
371         }
372         
373         if (ast_string_field_init(d, 512)) {
374                 ao2_ref(d, -1);
375                 return NULL;
376         }
377
378         AST_LIST_HEAD_INIT_NOLOCK(&d->documents);
379
380         /* These options need to be set to the configured default and may be overridden by
381          * SendFAX, ReceiveFAX, or FAXOPT */
382         d->option.request_t38 = AST_FAX_OPTFLAG_FALSE;
383         d->option.send_cng = AST_FAX_OPTFLAG_FALSE;
384         d->option.send_ced = AST_FAX_OPTFLAG_FALSE;
385         d->option.ecm = general_options.ecm;
386         d->option.statusevents = general_options.statusevents;
387         d->modems = general_options.modems;
388         d->minrate = general_options.minrate;
389         d->maxrate = general_options.maxrate;
390         ast_string_field_set(d, result, "FAILED");
391         ast_string_field_set(d, resultstr, "error starting fax session");
392         ast_string_field_set(d, error, "INIT_ERROR");
393
394         return d;
395 }
396
397 /*! \brief returns a reference counted details structure from the channel's fax datastore.  If the datastore
398  * does not exist it will be created */ 
399 static struct ast_fax_session_details *find_or_create_details(struct ast_channel *chan)
400 {
401         struct ast_fax_session_details *details;
402         struct ast_datastore *datastore;
403
404         if ((details = find_details(chan))) {
405                 return details;
406         }
407         /* channel does not have one so we must create one */
408         if (!(details = session_details_new())) {
409                 ast_log(LOG_WARNING, "channel '%s' can't get a FAX details structure for the datastore!\n", chan->name);
410                 return NULL;
411         }
412         if (!(datastore = ast_datastore_alloc(&fax_datastore, NULL))) {
413                 ao2_ref(details, -1);
414                 ast_log(LOG_WARNING, "channel '%s' can't get a datastore!\n", chan->name);
415                 return NULL;
416         }
417         /* add the datastore to the channel and increment the refcount */
418         datastore->data = details;
419         ao2_ref(details, 1);
420         ast_channel_lock(chan);
421         ast_channel_datastore_add(chan, datastore);
422         ast_channel_unlock(chan);
423         return details;
424 }
425
426 unsigned int ast_fax_maxrate(void)
427 {
428         return general_options.maxrate;
429 }
430
431 unsigned int ast_fax_minrate(void)
432 {
433         return general_options.minrate;
434 }
435
436 static int update_modem_bits(enum ast_fax_modems *bits, const char *value)
437 {               
438         char *m[5], *tok, *v = (char *)value;
439         int i = 0, j;
440
441         if (!(tok = strchr(v, ','))) {
442                 m[i++] = v;
443                 m[i] = NULL;
444         } else {
445                 tok = strtok(v, ", ");
446                 while (tok && (i < 5)) {
447                         m[i++] = tok;
448                         tok = strtok(NULL, ", ");
449                 }
450                 m[i] = NULL;
451         }
452
453         *bits = 0;
454         for (j = 0; j < i; j++) {
455                 if (!strcasecmp(m[j], "v17")) {
456                         *bits |= AST_FAX_MODEM_V17;
457                 } else if (!strcasecmp(m[j], "v27")) {
458                         *bits |= AST_FAX_MODEM_V27;
459                 } else if (!strcasecmp(m[j], "v29")) {
460                         *bits |= AST_FAX_MODEM_V29;
461                 } else if (!strcasecmp(m[j], "v34")) {
462                         *bits |= AST_FAX_MODEM_V34;
463                 } else {
464                         ast_log(LOG_WARNING, "ignoring invalid modem setting: '%s', valid options {v17 | v27 | v29 | v34}\n", m[j]);
465                 }
466         }
467         return 0;
468 }
469
470 static int ast_fax_modem_to_str(enum ast_fax_modems bits, char *tbuf, size_t bufsize)
471 {
472         int count = 0;
473
474         if (bits & AST_FAX_MODEM_V17) {
475                 strcat(tbuf, "V17");
476                 count++;
477         }
478         if (bits & AST_FAX_MODEM_V27) {
479                 if (count) {
480                         strcat(tbuf, ",");
481                 }
482                 strcat(tbuf, "V27");
483                 count++;
484         }
485         if (bits & AST_FAX_MODEM_V29) {
486                 if (count) {
487                         strcat(tbuf, ",");
488                 }
489                 strcat(tbuf, "V29");
490                 count++;
491         }
492         if (bits & AST_FAX_MODEM_V34) {
493                 if (count) {
494                         strcat(tbuf, ",");
495                 }
496                 strcat(tbuf, "V34");
497                 count++;
498         }
499
500         return 0;
501 }
502
503 /*! \brief register a FAX technology module */
504 int ast_fax_tech_register(struct ast_fax_tech *tech)
505 {
506         struct fax_module *fax;
507
508         if (!(fax = ast_calloc(1, sizeof(*fax)))) {
509                 return -1;
510         }
511         fax->tech = tech;
512         AST_RWLIST_WRLOCK(&faxmodules);
513         AST_RWLIST_INSERT_TAIL(&faxmodules, fax, list);
514         AST_RWLIST_UNLOCK(&faxmodules);
515         ast_module_ref(ast_module_info->self);
516
517         ast_verb(3, "Registered handler for '%s' (%s)\n", fax->tech->type, fax->tech->description);
518
519         return 0;
520 }
521
522 /*! \brief unregister a FAX technology module */
523 void ast_fax_tech_unregister(struct ast_fax_tech *tech)
524 {
525         struct fax_module *fax;
526
527         ast_verb(3, "Unregistering FAX module type '%s'\n", tech->type);
528
529         AST_RWLIST_WRLOCK(&faxmodules);
530         AST_RWLIST_TRAVERSE_SAFE_BEGIN(&faxmodules, fax, list) {
531                 if (fax->tech != tech) {
532                         continue;
533                 }
534                 AST_RWLIST_REMOVE_CURRENT(list);
535                 ast_module_unref(ast_module_info->self);
536                 ast_free(fax);
537                 ast_verb(4, "Unregistered FAX module type '%s'\n", tech->type);
538                 break;  
539         }
540         AST_RWLIST_TRAVERSE_SAFE_END;
541         AST_RWLIST_UNLOCK(&faxmodules);
542 }
543
544 /*! \brief convert a ast_fax_state to a string */
545 const char *ast_fax_state_to_str(enum ast_fax_state state)
546 {
547         switch (state) {
548         case AST_FAX_STATE_UNINITIALIZED:
549                 return "Uninitialized";
550         case AST_FAX_STATE_INITIALIZED:
551                 return "Initialized";
552         case AST_FAX_STATE_OPEN:
553                 return "Open";
554         case AST_FAX_STATE_ACTIVE:
555                 return "Active";
556         case AST_FAX_STATE_COMPLETE:
557                 return "Complete";
558         default:
559                 ast_log(LOG_WARNING, "unhandled FAX state: %d\n", state);
560                 return "Unknown";
561         }
562 }
563
564 void ast_fax_log(int level, const char *file, const int line, const char *function, const char *msg)
565 {
566         if (fax_logger_level != -1) {
567                 ast_log_dynamic_level(fax_logger_level, "%s", msg);
568         } else {
569                 ast_log(level, file, line, function, "%s", msg);
570         }
571 }
572
573 /*! \brief convert a rate string to a rate */
574 static unsigned int fax_rate_str_to_int(const char *ratestr)
575 {
576         int rate;
577
578         if (sscanf(ratestr, "%d", &rate) != 1) {
579                 ast_log(LOG_ERROR, "failed to sscanf '%s' to rate\n", ratestr);
580                 return 0;
581         }
582         switch (rate) {
583         case 2400:
584         case 4800:
585         case 7200:
586         case 9600:
587         case 12000:
588         case 14400:
589         case 28800:
590         case 33600:
591                 return rate;
592         default:
593                 ast_log(LOG_WARNING, "ignoring invalid rate '%s'.  Valid options are {2400 | 4800 | 7200 | 9600 | 12000 | 14400 | 28800 | 33600}\n", ratestr);
594                 return 0;
595         }
596 }
597
598 /*! \brief destroy a FAX session structure */
599 static void destroy_session(void *session)
600 {
601         struct ast_fax_session *s = session;
602
603         if (s->tech) {
604                 if (s->tech_pvt) {
605                         s->tech->destroy_session(s);
606                 }
607                 ast_module_unref(s->tech->module);
608         }
609
610         if (s->details) {
611                 ao2_ref(s->details, -1);
612         }
613         
614         if (s->debug_info) {
615                 ast_dsp_free(s->debug_info->dsp);
616                 ast_free(s->debug_info);
617         }
618
619         if (s->smoother) {
620                 ast_smoother_free(s->smoother);
621         }
622
623         ast_atomic_fetchadd_int(&faxregistry.active_sessions, -1);
624
625         ast_free(s->channame);
626         ast_free(s->chan_uniqueid);
627 }
628
629 /*! \brief create a FAX session */
630 static struct ast_fax_session *fax_session_new(struct ast_fax_session_details *details, struct ast_channel *chan)
631 {
632         struct ast_fax_session *s;
633         struct fax_module *faxmod;
634
635         if (!(s = ao2_alloc(sizeof(*s), destroy_session))) {
636                 return NULL;
637         }
638
639         ast_atomic_fetchadd_int(&faxregistry.active_sessions, 1);
640
641         if (details->option.debug && (details->caps & AST_FAX_TECH_AUDIO)) {
642                 if (!(s->debug_info = ast_calloc(1, sizeof(*(s->debug_info))))) {
643                         ao2_ref(s, -1);
644                         return NULL;
645                 }
646                 if (!(s->debug_info->dsp = ast_dsp_new())) {
647                         ast_free(s->debug_info);
648                         s->debug_info = NULL;
649                         ao2_ref(s, -1);
650                         return NULL;
651                 }
652                 ast_dsp_set_threshold(s->debug_info->dsp, 128);
653         }       
654
655         if (!(s->channame = ast_strdup(chan->name))) {
656                 ao2_ref(s, -1);
657                 return NULL;
658         }
659
660         if (!(s->chan_uniqueid = ast_strdup(chan->uniqueid))) {
661                 ao2_ref(s, -1);
662                 return NULL;
663         }
664
665         s->chan = chan;
666         s->details = details;
667         ao2_ref(s->details, 1);
668         s->state = AST_FAX_STATE_UNINITIALIZED;
669
670         details->id = s->id = ast_atomic_fetchadd_int(&faxregistry.nextsessionname, 1);
671
672         /* locate a FAX technology module that can handle said requirements */
673         AST_RWLIST_RDLOCK(&faxmodules);
674         AST_RWLIST_TRAVERSE(&faxmodules, faxmod, list) {
675                 if ((faxmod->tech->caps & details->caps) != details->caps) {
676                         continue;
677                 }
678                 ast_debug(4, "Requesting a new FAX session from '%s'.\n", faxmod->tech->description);
679                 ast_module_ref(faxmod->tech->module);
680                 s->tech = faxmod->tech;
681                 break;
682         }
683         AST_RWLIST_UNLOCK(&faxmodules);
684
685         if (!faxmod) {
686                 ast_log(LOG_ERROR, "Could not locate a FAX technology module with capabilities (0x%X)\n", details->caps);
687                 ao2_ref(s, -1);
688                 return NULL;
689         }
690         if (!(s->tech_pvt = s->tech->new_session(s, NULL))) {
691                 ast_log(LOG_ERROR, "FAX session failed to initialize.\n");
692                 ao2_ref(s, -1);
693                 ast_module_unref(faxmod->tech->module);
694                 return NULL;
695         }
696         /* link the session to the session container */
697         if (!(ao2_link(faxregistry.container, s))) {
698                 ast_log(LOG_ERROR, "failed to add FAX session '%d' to container.\n", s->id);
699                 ao2_ref(s, -1);
700                 ast_module_unref(faxmod->tech->module);
701                 return NULL;
702         }
703         ast_debug(4, "channel '%s' using FAX session '%d'\n", s->channame, s->id);
704
705         return s;
706 }
707
708 static void get_manager_event_info(struct ast_channel *chan, struct manager_event_info *info)
709 {
710         pbx_substitute_variables_helper(chan, "${CONTEXT}", info->context, sizeof(info->context));
711         pbx_substitute_variables_helper(chan, "${EXTEN}", info->exten, sizeof(info->exten));
712         pbx_substitute_variables_helper(chan, "${CALLERID(num)}", info->cid, sizeof(info->cid));
713 }
714
715
716 /* \brief Generate a string of filenames using the given prefix and separator.
717  * \param details the fax session details
718  * \param prefix the prefix to each filename
719  * \param separator the separator between filenames
720  *
721  * This function generates a string of filenames from the given details
722  * structure and using the given prefix and separator.
723  *
724  * \retval NULL there was an error generating the string
725  * \return the string generated string
726  */
727 static char *generate_filenames_string(struct ast_fax_session_details *details, char *prefix, char *separator)
728 {
729         char *filenames, *c;
730         size_t size = 0;
731         int first = 1;
732         struct ast_fax_document *doc;
733
734         /* don't process empty lists */
735         if (AST_LIST_EMPTY(&details->documents)) {
736                 return NULL;
737         }
738
739         /* Calculate the total length of all of the file names */
740         AST_LIST_TRAVERSE(&details->documents, doc, next) {
741                 size += strlen(separator) + strlen(prefix) + strlen(doc->filename);
742         }
743         size += 1; /* add space for the terminating null */
744
745         if (!(filenames = ast_malloc(size))) {
746                 return NULL;
747         }
748         c = filenames;
749
750         ast_build_string(&c, &size, "%s%s", prefix, AST_LIST_FIRST(&details->documents)->filename);
751         AST_LIST_TRAVERSE(&details->documents, doc, next) {
752                 if (first) {
753                         first = 0;
754                         continue;
755                 }
756
757                 ast_build_string(&c, &size, "%s%s%s", separator, prefix, doc->filename);
758         }
759
760         return filenames;
761 }
762
763 /*! \brief send a FAX status manager event */
764 static int report_fax_status(struct ast_channel *chan, struct ast_fax_session_details *details, const char *status)
765 {
766         char *filenames = generate_filenames_string(details, "FileName: ", "\r\n");
767         if (!filenames) {
768                 return 1;
769         }
770
771         ast_channel_lock(chan);
772         if (details->option.statusevents) {
773                 struct manager_event_info info;
774
775                 get_manager_event_info(chan, &info);
776                 manager_event(EVENT_FLAG_CALL,
777                               (details->caps & AST_FAX_TECH_RECEIVE) ? "ReceiveFAXStatus" : "SendFAXStatus",
778                               "Status: %s\r\n"
779                               "Channel: %s\r\n"
780                               "Context: %s\r\n"
781                               "Exten: %s\r\n"
782                               "CallerID: %s\r\n"
783                               "LocalStationID: %s\r\n"
784                               "%s\r\n",
785                               status,
786                               chan->name,
787                               info.context,
788                               info.exten,
789                               info.cid,
790                               details->localstationid,
791                               filenames);
792         }
793         ast_channel_unlock(chan);
794         ast_free(filenames);
795
796         return 0;
797 }
798
799 /*! \brief Set fax related channel variables. */
800 static void set_channel_variables(struct ast_channel *chan, struct ast_fax_session_details *details)
801 {
802         char buf[10];
803         pbx_builtin_setvar_helper(chan, "FAXSTATUS", S_OR(details->result, NULL));
804         pbx_builtin_setvar_helper(chan, "FAXERROR", S_OR(details->error, NULL));
805         pbx_builtin_setvar_helper(chan, "FAXSTATUSSTRING", S_OR(details->resultstr, NULL));
806         pbx_builtin_setvar_helper(chan, "REMOTESTATIONID", S_OR(details->remotestationid, NULL));
807         pbx_builtin_setvar_helper(chan, "FAXBITRATE", S_OR(details->transfer_rate, NULL));
808         pbx_builtin_setvar_helper(chan, "FAXRESOLUTION", S_OR(details->resolution, NULL));
809
810         snprintf(buf, sizeof(buf), "%d", details->pages_transferred);
811         pbx_builtin_setvar_helper(chan, "FAXPAGES", buf);
812 }
813
814 #define GENERIC_FAX_EXEC_ERROR_QUIET(fax, chan, errorstr, reason) \
815         do {    \
816                 ast_string_field_set(fax->details, result, S_OR(fax->details->result, "FAILED")); \
817                 ast_string_field_set(fax->details, resultstr, S_OR(fax->details->resultstr, reason)); \
818                 ast_string_field_set(fax->details, error, S_OR(fax->details->error, errorstr)); \
819                 set_channel_variables(chan, fax->details); \
820                 res = ms = -1; \
821         } while (0)
822
823 #define GENERIC_FAX_EXEC_ERROR(fax, chan, errorstr, reason)     \
824         do {    \
825                 ast_log(LOG_ERROR, "channel '%s' FAX session '%d' failure, reason: '%s' (%s)\n", chan->name, fax->id, reason, errorstr); \
826                 GENERIC_FAX_EXEC_ERROR_QUIET(fax, chan, errorstr, reason); \
827         } while (0)
828
829 static void t38_parameters_ast_to_fax(struct ast_fax_t38_parameters *dst, const struct ast_control_t38_parameters *src)
830 {
831         dst->version = src->version;
832         dst->max_ifp = src->max_ifp;
833         dst->rate = src->rate;
834         dst->rate_management = src->rate_management;
835         dst->fill_bit_removal = src->fill_bit_removal;
836         dst->transcoding_mmr = src->transcoding_mmr;
837         dst->transcoding_jbig = src->transcoding_jbig;
838 }
839
840 static void t38_parameters_fax_to_ast(struct ast_control_t38_parameters *dst, const struct ast_fax_t38_parameters *src)
841 {
842         dst->version = src->version;
843         dst->max_ifp = src->max_ifp;
844         dst->rate = src->rate;
845         dst->rate_management = src->rate_management;
846         dst->fill_bit_removal = src->fill_bit_removal;
847         dst->transcoding_mmr = src->transcoding_mmr;
848         dst->transcoding_jbig = src->transcoding_jbig;
849 }
850
851 static int set_fax_t38_caps(struct ast_channel *chan, struct ast_fax_session_details *details)
852 {
853         switch (ast_channel_get_t38_state(chan)) {
854         case T38_STATE_UNKNOWN:
855                 details->caps |= AST_FAX_TECH_T38;
856                 break;
857         case T38_STATE_UNAVAILABLE:
858                 details->caps |= AST_FAX_TECH_AUDIO;
859                 break;
860         case T38_STATE_NEGOTIATING: {
861                 /* the other end already sent us a T.38 reinvite, so we need to prod the channel
862                  * driver into resending their parameters to us if it supports doing so... if
863                  * not, we can't proceed, because we can't create a proper reply without them.
864                  * if it does work, the channel driver will send an AST_CONTROL_T38_PARAMETERS
865                  * with a request of AST_T38_REQUEST_NEGOTIATE, which will be read by the function
866                  * that gets called after this one completes
867                  */
868                 struct ast_control_t38_parameters parameters = { .request_response = AST_T38_REQUEST_PARMS, };
869                 if (ast_indicate_data(chan, AST_CONTROL_T38_PARAMETERS, &parameters, sizeof(parameters)) != AST_T38_REQUEST_PARMS) {
870                         ast_log(LOG_ERROR, "channel '%s' is in an unsupported T.38 negotiation state, cannot continue.\n", chan->name);
871                         return -1;
872                 }
873                 details->caps |= AST_FAX_TECH_T38;
874                 break;
875         }
876         default:
877                 ast_log(LOG_ERROR, "channel '%s' is in an unsupported T.38 negotiation state, cannot continue.\n", chan->name);
878                 return -1;
879         }
880
881         return 0;
882 }
883
884 static int disable_t38(struct ast_channel *chan)
885 {
886         int ms;
887         struct ast_frame *frame = NULL;
888         struct ast_control_t38_parameters t38_parameters = { .request_response = AST_T38_REQUEST_TERMINATE, };
889
890         ast_debug(1, "Shutting down T.38 on %s\n", chan->name);
891         if (ast_indicate_data(chan, AST_CONTROL_T38_PARAMETERS, &t38_parameters, sizeof(t38_parameters)) != 0) {
892                 ast_log(LOG_WARNING, "error while disabling T.38 on channel '%s'\n", chan->name);
893                 return -1;
894         }
895
896         /* wait up to five seconds for negotiation to complete */
897         ms = 5000;
898
899         while (ms > 0) {
900                 ms = ast_waitfor(chan, ms);
901                 if (ms < 0) {
902                         ast_log(LOG_WARNING, "error while disabling T.38 on channel '%s'\n", chan->name);
903                         return -1;
904                 }
905
906                 if (ms == 0) { /* all done, nothing happened */
907                         ast_log(LOG_WARNING, "channel '%s' timed-out during T.38 shutdown\n", chan->name);
908                         break;
909                 }
910
911                 if (!(frame = ast_read(chan))) {
912                         return -1;
913                 }
914                 if ((frame->frametype == AST_FRAME_CONTROL) &&
915                     (frame->subclass.integer == AST_CONTROL_T38_PARAMETERS) &&
916                     (frame->datalen == sizeof(t38_parameters))) {
917                         struct ast_control_t38_parameters *parameters = frame->data.ptr;
918
919                         switch (parameters->request_response) {
920                         case AST_T38_TERMINATED:
921                                 ast_debug(1, "Shut down T.38 on %s\n", chan->name);
922                                 break;
923                         case AST_T38_REFUSED:
924                                 ast_log(LOG_WARNING, "channel '%s' refused to disable T.38\n", chan->name);
925                                 ast_frfree(frame);
926                                 return -1;
927                         default:
928                                 ast_log(LOG_ERROR, "channel '%s' failed to disable T.38\n", chan->name);
929                                 ast_frfree(frame);
930                                 return -1;
931                         }
932                         ast_frfree(frame);
933                         break;
934                 }
935                 ast_frfree(frame);
936         }
937
938         return 0;
939 }
940
941 static struct ast_control_t38_parameters our_t38_parameters = {
942         .version = 0,
943         .max_ifp = 400,
944         .rate = AST_T38_RATE_14400,
945         .rate_management = AST_T38_RATE_MANAGEMENT_TRANSFERRED_TCF,
946 };
947
948 /*! \brief this is the generic FAX session handling function */
949 static int generic_fax_exec(struct ast_channel *chan, struct ast_fax_session_details *details)
950 {
951         int ms;
952         int timeout = RES_FAX_TIMEOUT;
953         int res = 0, chancount;
954         unsigned int expected_frametype = -1;
955         union ast_frame_subclass expected_framesubclass = { .integer = -1 };
956         unsigned int t38negotiated = (ast_channel_get_t38_state(chan) == T38_STATE_NEGOTIATED);
957         struct ast_control_t38_parameters t38_parameters;
958         const char *tempvar;
959         struct ast_fax_session *fax = NULL;
960         struct ast_frame *frame = NULL;
961         struct ast_channel *c = chan;
962         unsigned int orig_write_format = 0, orig_read_format = 0;
963
964         chancount = 1;
965
966         /* create the FAX session */
967         if (!(fax = fax_session_new(details, chan))) {
968                 ast_log(LOG_ERROR, "Can't create a FAX session, FAX attempt failed.\n");
969                 report_fax_status(chan, details, "No Available Resource");
970                 return -1;
971         }
972
973         ast_channel_lock(chan);
974         /* update session details */    
975         if (ast_strlen_zero(details->headerinfo) && (tempvar = pbx_builtin_getvar_helper(chan, "LOCALHEADERINFO"))) {
976                 ast_string_field_set(details, headerinfo, tempvar);
977         }
978         if (ast_strlen_zero(details->localstationid)) {
979                 tempvar = pbx_builtin_getvar_helper(chan, "LOCALSTATIONID");
980                 ast_string_field_set(details, localstationid, tempvar ? tempvar : "unknown");
981         }
982         ast_channel_unlock(chan);
983
984         report_fax_status(chan, details, "Allocating Resources");
985
986         if (details->caps & AST_FAX_TECH_AUDIO) {
987                 expected_frametype = AST_FRAME_VOICE;;
988                 expected_framesubclass.codec = AST_FORMAT_SLINEAR;
989                 orig_write_format = chan->writeformat;
990                 if (ast_set_write_format(chan, AST_FORMAT_SLINEAR) < 0) {
991                         ast_log(LOG_ERROR, "channel '%s' failed to set write format to signed linear'.\n", chan->name);
992                         ao2_lock(faxregistry.container);
993                         ao2_unlink(faxregistry.container, fax);
994                         ao2_unlock(faxregistry.container);
995                         ao2_ref(fax, -1);
996                         ast_channel_unlock(chan);
997                         return -1;
998                 }
999                 orig_read_format = chan->readformat;
1000                 if (ast_set_read_format(chan, AST_FORMAT_SLINEAR) < 0) {
1001                         ast_log(LOG_ERROR, "channel '%s' failed to set read format to signed linear.\n", chan->name);
1002                         ao2_lock(faxregistry.container);
1003                         ao2_unlink(faxregistry.container, fax);
1004                         ao2_unlock(faxregistry.container);
1005                         ao2_ref(fax, -1);
1006                         ast_channel_unlock(chan);
1007                         return -1;
1008                 }
1009                 if (fax->smoother) {
1010                         ast_smoother_free(fax->smoother);
1011                         fax->smoother = NULL;
1012                 }
1013                 if (!(fax->smoother = ast_smoother_new(320))) {
1014                         ast_log(LOG_WARNING, "Channel '%s' FAX session '%d' failed to obtain a smoother.\n", chan->name, fax->id);
1015                 }
1016         } else {
1017                 expected_frametype = AST_FRAME_MODEM;
1018                 expected_framesubclass.codec = AST_MODEM_T38;
1019         }
1020
1021         if (fax->debug_info) {
1022                 fax->debug_info->base_tv = ast_tvnow();
1023         }
1024
1025         /* reset our result fields just in case the fax tech driver wants to
1026          * set custom error messages */
1027         ast_string_field_set(details, result, "");
1028         ast_string_field_set(details, resultstr, "");
1029         ast_string_field_set(details, error, "");
1030         set_channel_variables(chan, details);
1031
1032         if (fax->tech->start_session(fax) < 0) {
1033                 GENERIC_FAX_EXEC_ERROR(fax, chan, "INIT_ERROR", "failed to start FAX session");
1034         }
1035
1036         report_fax_status(chan, details, "FAX Transmission In Progress");
1037
1038         ast_debug(5, "channel %s will wait on FAX fd %d\n", chan->name, fax->fd);
1039
1040         /* handle frames for the session */
1041         ms = 1000;
1042         while ((res > -1) && (ms > -1) && (timeout > 0)) {
1043                 struct ast_channel *ready_chan;
1044                 int ofd, exception;
1045
1046                 ms = 1000;
1047                 errno = 0;
1048                 ready_chan = ast_waitfor_nandfds(&c, chancount, &fax->fd, 1, &exception, &ofd, &ms);
1049                 if (ready_chan) {
1050                         if (!(frame = ast_read(chan))) {
1051                                 /* the channel is probably gone, so lets stop polling on it and let the
1052                                  * FAX session complete before we exit the application.  if needed,
1053                                  * send the FAX stack silence so the modems can finish their session without
1054                                  * any problems */
1055                                 ast_log(LOG_NOTICE, "Channel '%s' did not return a frame; probably hung up.\n", chan->name);
1056                                 GENERIC_FAX_EXEC_ERROR_QUIET(fax, chan, "HANGUP", "remote end hungup");
1057                                 c = NULL;
1058                                 chancount = 0;
1059                                 timeout -= (1000 - ms);
1060                                 fax->tech->cancel_session(fax);
1061                                 if (fax->tech->generate_silence) {
1062                                         fax->tech->generate_silence(fax);
1063                                 }
1064                                 continue;
1065                         }
1066
1067                         if ((frame->frametype == AST_FRAME_CONTROL) &&
1068                             (frame->subclass.integer == AST_CONTROL_T38_PARAMETERS) &&
1069                             (frame->datalen == sizeof(t38_parameters))) {
1070                                 unsigned int was_t38 = t38negotiated;
1071                                 struct ast_control_t38_parameters *parameters = frame->data.ptr;
1072                                 
1073                                 switch (parameters->request_response) {
1074                                 case AST_T38_REQUEST_NEGOTIATE:
1075                                         /* the other end has requested a switch to T.38, so reply that we are willing, if we can
1076                                          * do T.38 as well
1077                                          */
1078                                         t38_parameters_fax_to_ast(&t38_parameters, &details->our_t38_parameters);
1079                                         t38_parameters.request_response = (details->caps & AST_FAX_TECH_T38) ? AST_T38_NEGOTIATED : AST_T38_REFUSED;
1080                                         ast_indicate_data(chan, AST_CONTROL_T38_PARAMETERS, &t38_parameters, sizeof(t38_parameters));
1081                                         break;
1082                                 case AST_T38_NEGOTIATED:
1083                                         t38_parameters_ast_to_fax(&details->their_t38_parameters, parameters);
1084                                         t38negotiated = 1;
1085                                         break;
1086                                 default:
1087                                         break;
1088                                 }
1089                                 if (t38negotiated && !was_t38) {
1090                                         fax->tech->switch_to_t38(fax);
1091                                         details->caps &= ~AST_FAX_TECH_AUDIO;
1092                                         expected_frametype = AST_FRAME_MODEM;
1093                                         expected_framesubclass.codec = AST_MODEM_T38;
1094                                         if (fax->smoother) {
1095                                                 ast_smoother_free(fax->smoother);
1096                                                 fax->smoother = NULL;
1097                                         }
1098                                         
1099                                         report_fax_status(chan, details, "T.38 Negotiated");
1100                                         
1101                                         ast_verb(3, "Channel '%s' switched to T.38 FAX session '%d'.\n", chan->name, fax->id);
1102                                 }
1103                         } else if ((frame->frametype == expected_frametype) &&
1104                                    (!memcmp(&frame->subclass, &expected_framesubclass, sizeof(frame->subclass)))) {
1105                                 struct ast_frame *f;
1106                                 
1107                                 if (fax->smoother) {
1108                                         /* push the frame into a smoother */
1109                                         if (ast_smoother_feed(fax->smoother, frame) < 0) {
1110                                                 GENERIC_FAX_EXEC_ERROR(fax, chan, "UNKNOWN", "Failed to feed the smoother");
1111                                         }
1112                                         while ((f = ast_smoother_read(fax->smoother)) && (f->data.ptr)) {
1113                                                 if (fax->debug_info) {
1114                                                         debug_check_frame_for_silence(fax, 1, f);
1115                                                 }
1116                                                 /* write the frame to the FAX stack */
1117                                                 fax->tech->write(fax, f);
1118                                                 fax->frames_received++;
1119                                                 if (f != frame) {
1120                                                         ast_frfree(f);
1121                                                 }
1122                                         }
1123                                 } else {
1124                                         /* write the frame to the FAX stack */
1125                                         fax->tech->write(fax, frame);
1126                                         fax->frames_received++;
1127                                 }
1128                                 timeout = RES_FAX_TIMEOUT;
1129                         }
1130                         ast_frfree(frame);
1131                 } else if (ofd == fax->fd) {
1132                         /* read a frame from the FAX stack and send it out the channel.
1133                          * the FAX stack will return a NULL if the FAX session has already completed */
1134                         if (!(frame = fax->tech->read(fax))) {
1135                                 break;
1136                         }
1137
1138                         if (fax->debug_info && (frame->frametype == AST_FRAME_VOICE)) {
1139                                 debug_check_frame_for_silence(fax, 0, frame);
1140                         }
1141
1142                         ast_write(chan, frame);
1143                         fax->frames_sent++;
1144                         ast_frfree(frame);
1145                         timeout = RES_FAX_TIMEOUT;
1146                 } else {
1147                         if (ms && (ofd < 0)) {
1148                                 if ((errno == 0) || (errno == EINTR)) {
1149                                         timeout -= (1000 - ms);
1150                                         if (timeout <= 0)
1151                                                 GENERIC_FAX_EXEC_ERROR(fax, chan, "TIMEOUT", "fax session timed-out");
1152                                         continue;
1153                                 } else {
1154                                         ast_log(LOG_WARNING, "something bad happened while channel '%s' was polling.\n", chan->name);
1155                                         GENERIC_FAX_EXEC_ERROR(fax, chan, "UNKNOWN", "error polling data");
1156                                         res = ms;
1157                                         break;
1158                                 }
1159                         } else {
1160                                 /* nothing happened */
1161                                 if (timeout > 0) {
1162                                         timeout -= 1000;
1163                                         if (timeout <= 0)
1164                                                 GENERIC_FAX_EXEC_ERROR(fax, chan, "TIMEOUT", "fax session timed-out");
1165                                         continue;
1166                                 } else {
1167                                         ast_log(LOG_WARNING, "channel '%s' timed-out during the FAX transmission.\n", chan->name);
1168                                         GENERIC_FAX_EXEC_ERROR(fax, chan, "TIMEOUT", "fax session timed-out");
1169                                         break;
1170                                 }
1171                         }
1172                 }
1173         }
1174         ast_debug(3, "channel '%s' - event loop stopped { timeout: %d, ms: %d, res: %d }\n", chan->name, timeout, ms, res);
1175
1176         set_channel_variables(chan, details);
1177
1178         ast_atomic_fetchadd_int(&faxregistry.fax_complete, 1);
1179         if (!strcasecmp(details->result, "FAILED")) {
1180                 ast_atomic_fetchadd_int(&faxregistry.fax_failures, 1);
1181         }
1182
1183         if (fax) {
1184                 ao2_lock(faxregistry.container);
1185                 ao2_unlink(faxregistry.container, fax);
1186                 ao2_unlock(faxregistry.container);
1187                 ao2_ref(fax, -1);
1188         }
1189
1190         /* if the channel is still alive, and we changed its read/write formats,
1191          * restore them now
1192          */
1193         if (chancount) {
1194                 if (orig_read_format) {
1195                         ast_set_read_format(chan, orig_read_format);
1196                 }
1197                 if (orig_write_format) {
1198                         ast_set_write_format(chan, orig_write_format);
1199                 }
1200         }
1201
1202         /* return the chancount so the calling function can determine if the channel hungup during this FAX session or not */
1203         return chancount;
1204 }
1205
1206 static int receivefax_t38_init(struct ast_channel *chan, struct ast_fax_session_details *details)
1207 {
1208         int ms;
1209         struct ast_frame *frame = NULL;
1210         struct ast_control_t38_parameters t38_parameters;
1211
1212         t38_parameters_ast_to_fax(&details->our_t38_parameters, &our_t38_parameters);
1213
1214         /* don't send any audio if we've already received a T.38 reinvite */
1215         if (ast_channel_get_t38_state(chan) != T38_STATE_NEGOTIATING) {
1216                 /* generate 3 seconds of CED */
1217                 if (ast_playtones_start(chan, 1024, "!2100/3000", 1)) {
1218                         ast_log(LOG_ERROR, "error generating CED tone on %s\n", chan->name);
1219                         return -1;
1220                 }
1221
1222                 ms = 3000;
1223                 while (ms > 0) {
1224                         ms = ast_waitfor(chan, ms);
1225                         if (ms < 0) {
1226                                 ast_log(LOG_ERROR, "error while generating CED tone on %s\n", chan->name);
1227                                 ast_playtones_stop(chan);
1228                                 return -1;
1229                         }
1230
1231                         if (ms == 0) { /* all done, nothing happened */
1232                                 break;
1233                         }
1234
1235                         if (!(frame = ast_read(chan))) {
1236                                 ast_log(LOG_ERROR, "error reading frame while generating CED tone on %s\n", chan->name);
1237                                 ast_playtones_stop(chan);
1238                                 return -1;
1239                         }
1240
1241                         if ((frame->frametype == AST_FRAME_CONTROL) &&
1242                             (frame->subclass.integer == AST_CONTROL_T38_PARAMETERS) &&
1243                             (frame->datalen == sizeof(t38_parameters))) {
1244                                 struct ast_control_t38_parameters *parameters = frame->data.ptr;
1245
1246                                 switch (parameters->request_response) {
1247                                 case AST_T38_REQUEST_NEGOTIATE:
1248                                         /* the other end has requested a switch to T.38, so reply that we are willing, if we can
1249                                          * do T.38 as well
1250                                          */
1251                                         t38_parameters_fax_to_ast(&t38_parameters, &details->our_t38_parameters);
1252                                         t38_parameters.request_response = (details->caps & AST_FAX_TECH_T38) ? AST_T38_NEGOTIATED : AST_T38_REFUSED;
1253                                         ast_indicate_data(chan, AST_CONTROL_T38_PARAMETERS, &t38_parameters, sizeof(t38_parameters));
1254                                         ast_playtones_stop(chan);
1255                                         break;
1256                                 case AST_T38_NEGOTIATED:
1257                                         ast_log(LOG_NOTICE, "Negotiated T.38 for receive on %s\n", chan->name);
1258                                         t38_parameters_ast_to_fax(&details->their_t38_parameters, parameters);
1259                                         details->caps &= ~AST_FAX_TECH_AUDIO;
1260                                         report_fax_status(chan, details, "T.38 Negotiated");
1261                                         break;
1262                                 default:
1263                                         break;
1264                                 }
1265                         }
1266                         ast_frfree(frame);
1267                 }
1268
1269                 ast_playtones_stop(chan);
1270         }
1271
1272         /* if T.38 was negotiated, we are done initializing */
1273         if (ast_channel_get_t38_state(chan) == T38_STATE_NEGOTIATED) {
1274                 return 0;
1275         }
1276
1277         /* request T.38 */
1278         ast_log(LOG_NOTICE, "Negotiating T.38 for receive on %s\n", chan->name);
1279
1280         /* wait up to five seconds for negotiation to complete */
1281         ms = 5000;
1282
1283         /* set parameters based on the session's parameters */
1284         t38_parameters_fax_to_ast(&t38_parameters, &details->our_t38_parameters);
1285         t38_parameters.request_response = AST_T38_REQUEST_NEGOTIATE;
1286         if ((ast_indicate_data(chan, AST_CONTROL_T38_PARAMETERS, &t38_parameters, sizeof(t38_parameters)) != 0)) {
1287                 return -1;
1288         }
1289
1290         while (ms > 0) {
1291                 ms = ast_waitfor(chan, ms);
1292                 if (ms < 0) {
1293                         ast_log(LOG_WARNING, "error on '%s' while waiting for T.38 negotiation.\n", chan->name);
1294                         return -1;
1295                 }
1296
1297                 if (ms == 0) { /* all done, nothing happened */
1298                         ast_log(LOG_WARNING, "channel '%s' timed-out during the T.38 negotiation.\n", chan->name);
1299                         details->caps &= ~AST_FAX_TECH_T38;
1300                         break;
1301                 }
1302
1303                 if (!(frame = ast_read(chan))) {
1304                         ast_log(LOG_WARNING, "error on '%s' while waiting for T.38 negotiation.\n", chan->name);
1305                         return -1;
1306                 }
1307
1308                 if ((frame->frametype == AST_FRAME_CONTROL) &&
1309                                 (frame->subclass.integer == AST_CONTROL_T38_PARAMETERS) &&
1310                                 (frame->datalen == sizeof(t38_parameters))) {
1311                         struct ast_control_t38_parameters *parameters = frame->data.ptr;
1312
1313                         switch (parameters->request_response) {
1314                         case AST_T38_REQUEST_NEGOTIATE:
1315                                 t38_parameters_fax_to_ast(&t38_parameters, &details->our_t38_parameters);
1316                                 t38_parameters.request_response = AST_T38_NEGOTIATED;
1317                                 ast_indicate_data(chan, AST_CONTROL_T38_PARAMETERS, &t38_parameters, sizeof(t38_parameters));
1318                                 break;
1319                         case AST_T38_NEGOTIATED:
1320                                 ast_log(LOG_NOTICE, "Negotiated T.38 for receive on %s\n", chan->name);
1321                                 t38_parameters_ast_to_fax(&details->their_t38_parameters, parameters);
1322                                 details->caps &= ~AST_FAX_TECH_AUDIO;
1323                                 report_fax_status(chan, details, "T.38 Negotiated");
1324                                 ms = 0;
1325                                 break;
1326                         case AST_T38_REFUSED:
1327                                 ast_log(LOG_WARNING, "channel '%s' refused to negotiate T.38\n", chan->name);
1328                                 details->caps &= ~AST_FAX_TECH_T38;
1329                                 ms = 0;
1330                                 break;
1331                         default:
1332                                 ast_log(LOG_ERROR, "channel '%s' failed to negotiate T.38\n", chan->name);
1333                                 details->caps &= ~AST_FAX_TECH_T38;
1334                                 ms = 0;
1335                                 break;
1336                         }
1337                 }
1338                 ast_frfree(frame);
1339         }
1340
1341         /* if T.38 was negotiated, we are done initializing */
1342         if (ast_channel_get_t38_state(chan) == T38_STATE_NEGOTIATED) {
1343                 return 0;
1344         }
1345
1346         /* if we made it here, then T.38 failed, check the 'f' flag */
1347         if (details->option.allow_audio != AST_FAX_OPTFLAG_TRUE) {
1348                 ast_log(LOG_WARNING, "Audio FAX not allowed on channel '%s' and T.38 negotiation failed; aborting.\n", chan->name);
1349                 return -1;
1350         }
1351
1352         /* ok, audio fallback is allowed */
1353         details->caps |= AST_FAX_TECH_AUDIO;
1354
1355         return 0;
1356 }
1357
1358 /*! \brief initiate a receive FAX session */
1359 static int receivefax_exec(struct ast_channel *chan, const char *data)
1360 {
1361         char *parse;
1362         int channel_alive;
1363         struct ast_fax_session_details *details;
1364         struct ast_fax_document *doc;
1365         AST_DECLARE_APP_ARGS(args,
1366                 AST_APP_ARG(filename);
1367                 AST_APP_ARG(options);
1368         );
1369         struct ast_flags opts = { 0, };
1370         struct manager_event_info info;
1371
1372         /* initialize output channel variables */
1373         pbx_builtin_setvar_helper(chan, "FAXSTATUS", "FAILED");
1374         pbx_builtin_setvar_helper(chan, "REMOTESTATIONID", NULL);
1375         pbx_builtin_setvar_helper(chan, "FAXPAGES", "0");
1376         pbx_builtin_setvar_helper(chan, "FAXBITRATE", NULL);
1377         pbx_builtin_setvar_helper(chan, "FAXRESOLUTION", NULL);
1378
1379         /* Get a FAX session details structure from the channel's FAX datastore and create one if
1380          * it does not already exist. */
1381         if (!(details = find_or_create_details(chan))) {
1382                 pbx_builtin_setvar_helper(chan, "FAXERROR", "MEMORY_ERROR");
1383                 pbx_builtin_setvar_helper(chan, "FAXSTATUSSTRING", "error allocating memory");
1384                 ast_log(LOG_ERROR, "System cannot provide memory for session requirements.\n");
1385                 return -1;
1386         }
1387
1388         set_channel_variables(chan, details);
1389
1390         if (ast_strlen_zero(data)) {
1391                 ast_string_field_set(details, error, "INVALID_ARGUMENTS");
1392                 ast_string_field_set(details, resultstr, "invalid arguments");
1393                 set_channel_variables(chan, details);
1394                 ast_log(LOG_WARNING, "%s requires an argument (filename[,options])\n", app_receivefax);
1395                 ao2_ref(details, -1);
1396                 return -1;
1397         }
1398         parse = ast_strdupa(data);
1399         AST_STANDARD_APP_ARGS(args, parse);
1400
1401         if (!ast_strlen_zero(args.options) &&
1402             ast_app_parse_options(fax_exec_options, &opts, NULL, args.options)) {
1403                 ast_string_field_set(details, error, "INVALID_ARGUMENTS");
1404                 ast_string_field_set(details, resultstr, "invalid arguments");
1405                 set_channel_variables(chan, details);
1406                 ao2_ref(details, -1);
1407                 return -1;
1408         }
1409         if (ast_strlen_zero(args.filename)) {
1410                 ast_string_field_set(details, error, "INVALID_ARGUMENTS");
1411                 ast_string_field_set(details, resultstr, "invalid arguments");
1412                 set_channel_variables(chan, details);
1413                 ast_log(LOG_WARNING, "%s requires an argument (filename[,options])\n", app_receivefax);
1414                 ao2_ref(details, -1);
1415                 return -1;
1416         }
1417
1418         /* check for unsupported FAX application options */
1419         if (ast_test_flag(&opts, OPT_CALLERMODE) || ast_test_flag(&opts, OPT_CALLEDMODE)) {
1420                 ast_string_field_set(details, error, "INVALID_ARGUMENTS");
1421                 ast_string_field_set(details, resultstr, "invalid arguments");
1422                 set_channel_variables(chan, details);
1423                 ast_log(LOG_WARNING, "%s does not support polling\n", app_receivefax);
1424                 ao2_ref(details, -1);
1425                 return -1;
1426         }
1427         
1428         /* make sure the channel is up */
1429         if (chan->_state != AST_STATE_UP) {
1430                 if (ast_answer(chan)) {
1431                         ast_log(LOG_WARNING, "Channel '%s' failed answer attempt.\n", chan->name);
1432                         ao2_ref(details, -1);
1433                         return -1;
1434                 }
1435         }
1436
1437         ast_atomic_fetchadd_int(&faxregistry.fax_rx_attempts, 1);
1438
1439         pbx_builtin_setvar_helper(chan, "FAXERROR", "Channel Problems");
1440         pbx_builtin_setvar_helper(chan, "FAXSTATUSSTRING", "Error before FAX transmission started.");
1441
1442         if (!(doc = ast_calloc(1, sizeof(*doc) + strlen(args.filename) + 1))) {
1443                 ast_string_field_set(details, error, "MEMORY_ERROR");
1444                 ast_string_field_set(details, resultstr, "error allocating memory");
1445                 set_channel_variables(chan, details);
1446                 ast_log(LOG_ERROR, "System cannot provide memory for session requirements.\n");
1447                 ao2_ref(details, -1);
1448                 return -1;
1449         }
1450
1451         strcpy(doc->filename, args.filename);
1452         AST_LIST_INSERT_TAIL(&details->documents, doc, next);
1453
1454         ast_verb(3, "Channel '%s' receiving FAX '%s'\n", chan->name, args.filename);
1455
1456         details->caps = AST_FAX_TECH_RECEIVE;
1457
1458         /* check for debug */
1459         if (ast_test_flag(&opts, OPT_DEBUG) || global_fax_debug) {
1460                 details->option.debug = AST_FAX_OPTFLAG_TRUE;
1461         }
1462
1463         /* check for request for status events */
1464         if (ast_test_flag(&opts, OPT_STATUS)) {
1465                 details->option.statusevents = AST_FAX_OPTFLAG_TRUE;
1466         }
1467
1468         if ((ast_channel_get_t38_state(chan) == T38_STATE_UNAVAILABLE) ||
1469             ast_test_flag(&opts, OPT_ALLOWAUDIO)) {
1470                 details->option.allow_audio = AST_FAX_OPTFLAG_TRUE;
1471         }
1472
1473         if (set_fax_t38_caps(chan, details)) {
1474                 ast_string_field_set(details, error, "T38_NEG_ERROR");
1475                 ast_string_field_set(details, resultstr, "error negotiating T.38");
1476                 set_channel_variables(chan, details);
1477                 ao2_ref(details, -1);
1478                 return -1;
1479         }
1480
1481         if (details->caps & AST_FAX_TECH_T38) {
1482                 if (receivefax_t38_init(chan, details)) {
1483                         ast_string_field_set(details, error, "T38_NEG_ERROR");
1484                         ast_string_field_set(details, resultstr, "error negotiating T.38");
1485                         set_channel_variables(chan, details);
1486                         ao2_ref(details, -1);
1487                         ast_log(LOG_ERROR, "error initializing channel '%s' in T.38 mode\n", chan->name);
1488                         return -1;
1489                 }
1490         } else {
1491                 details->option.send_ced = 1;
1492         }
1493
1494         if ((channel_alive = generic_fax_exec(chan, details)) < 0) {
1495                 ast_atomic_fetchadd_int(&faxregistry.fax_failures, 1);
1496         }
1497
1498         if (ast_channel_get_t38_state(chan) == T38_STATE_NEGOTIATED) {
1499                 if (disable_t38(chan)) {
1500                         ast_log(LOG_WARNING, "error disabling T.38 mode on %s\n", chan->name);
1501                 }
1502         }
1503
1504         /* send out the AMI completion event */
1505         ast_channel_lock(chan);
1506
1507         get_manager_event_info(chan, &info);
1508         manager_event(EVENT_FLAG_CALL,
1509                       "ReceiveFAX", 
1510                       "Channel: %s\r\n"
1511                       "Context: %s\r\n"
1512                       "Exten: %s\r\n"
1513                       "CallerID: %s\r\n"
1514                       "RemoteStationID: %s\r\n"
1515                       "LocalStationID: %s\r\n"
1516                       "PagesTransferred: %s\r\n"
1517                       "Resolution: %s\r\n"
1518                       "TransferRate: %s\r\n"
1519                       "FileName: %s\r\n",
1520                       chan->name,
1521                       info.context,
1522                       info.exten,
1523                       info.cid,
1524                       pbx_builtin_getvar_helper(chan, "REMOTESTATIONID"),
1525                       pbx_builtin_getvar_helper(chan, "LOCALSTATIONID"),
1526                       pbx_builtin_getvar_helper(chan, "FAXPAGES"),
1527                       pbx_builtin_getvar_helper(chan, "FAXRESOLUTION"),
1528                       pbx_builtin_getvar_helper(chan, "FAXBITRATE"),
1529                       args.filename);
1530         ast_channel_unlock(chan);
1531
1532         ao2_ref(details, -1);
1533
1534         /* If the channel hungup return -1; otherwise, return 0 to continue in the dialplan */
1535         return (!channel_alive) ? -1 : 0;
1536 }
1537
1538 static int sendfax_t38_init(struct ast_channel *chan, struct ast_fax_session_details *details)
1539 {
1540         int ms;
1541         struct ast_frame *frame = NULL;
1542         struct ast_control_t38_parameters t38_parameters;
1543
1544         t38_parameters_ast_to_fax(&details->our_t38_parameters, &our_t38_parameters);
1545
1546         /* send CNG tone while listening for the receiver to initiate a switch
1547          * to T.38 mode; if they do, stop sending the CNG tone and proceed with
1548          * the switch.
1549          *
1550          * 10500 is enough time for 3 CNG tones
1551          */
1552         ms = 10500;
1553
1554         /* don't send any audio if we've already received a T.38 reinvite */
1555         if (ast_channel_get_t38_state(chan) != T38_STATE_NEGOTIATING) {
1556                 if (ast_playtones_start(chan, 1024, "!1100/500,!0/3000,!1100/500,!0/3000,!1100/500,!0/3000", 1)) {
1557                         ast_log(LOG_ERROR, "error generating CNG tone on %s\n", chan->name);
1558                         return -1;
1559                 }
1560         }
1561
1562         while (ms > 0) {
1563                 ms = ast_waitfor(chan, ms);
1564                 if (ms < 0) {
1565                         ast_log(LOG_ERROR, "error while generating CNG tone on %s\n", chan->name);
1566                         ast_playtones_stop(chan);
1567                         return -1;
1568                 }
1569
1570                 if (ms == 0) { /* all done, nothing happened */
1571                         break;
1572                 }
1573
1574                 if (!(frame = ast_read(chan))) {
1575                         ast_log(LOG_ERROR, "error reading frame while generating CNG tone on %s\n", chan->name);
1576                         ast_playtones_stop(chan);
1577                         return -1;
1578                 }
1579
1580                 if ((frame->frametype == AST_FRAME_CONTROL) &&
1581                                 (frame->subclass.integer == AST_CONTROL_T38_PARAMETERS) &&
1582                                 (frame->datalen == sizeof(t38_parameters))) {
1583                         struct ast_control_t38_parameters *parameters = frame->data.ptr;
1584
1585                         switch (parameters->request_response) {
1586                         case AST_T38_REQUEST_NEGOTIATE:
1587                                 /* the other end has requested a switch to T.38, so reply that we are willing, if we can
1588                                  * do T.38 as well
1589                                  */
1590                                 t38_parameters_fax_to_ast(&t38_parameters, &details->our_t38_parameters);
1591                                 t38_parameters.request_response = (details->caps & AST_FAX_TECH_T38) ? AST_T38_NEGOTIATED : AST_T38_REFUSED;
1592                                 ast_indicate_data(chan, AST_CONTROL_T38_PARAMETERS, &t38_parameters, sizeof(t38_parameters));
1593                                 ast_playtones_stop(chan);
1594                                 break;
1595                         case AST_T38_NEGOTIATED:
1596                                 ast_log(LOG_NOTICE, "Negotiated T.38 for send on %s\n", chan->name);
1597                                 t38_parameters_ast_to_fax(&details->their_t38_parameters, parameters);
1598                                 details->caps &= ~AST_FAX_TECH_AUDIO;
1599                                 report_fax_status(chan, details, "T.38 Negotiated");
1600                                 ms = 0;
1601                                 break;
1602                         default:
1603                                 break;
1604                         }
1605                 }
1606                 ast_frfree(frame);
1607         }
1608
1609         ast_playtones_stop(chan);
1610
1611         if (ast_channel_get_t38_state(chan) == T38_STATE_NEGOTIATED) {
1612                 return 0;
1613         }
1614
1615         /* T.38 negotiation did not happen, initiate a switch if requested */
1616         if (details->option.request_t38 == AST_FAX_OPTFLAG_TRUE) {
1617                 ast_log(LOG_NOTICE, "Negotiating T.38 for send on %s\n", chan->name);
1618
1619                 /* wait up to five seconds for negotiation to complete */
1620                 ms = 5000;
1621
1622                 /* set parameters based on the session's parameters */
1623                 t38_parameters_fax_to_ast(&t38_parameters, &details->our_t38_parameters);
1624                 t38_parameters.request_response = AST_T38_REQUEST_NEGOTIATE;
1625                 if ((ast_indicate_data(chan, AST_CONTROL_T38_PARAMETERS, &t38_parameters, sizeof(t38_parameters)) != 0)) {
1626                         return -1;
1627                 }
1628
1629                 while (ms > 0) {
1630                         ms = ast_waitfor(chan, ms);
1631                         if (ms < 0) {
1632                                 ast_log(LOG_WARNING, "error on '%s' while waiting for T.38 negotiation.\n", chan->name);
1633                                 return -1;
1634                         }
1635
1636                         if (ms == 0) { /* all done, nothing happened */
1637                                 ast_log(LOG_WARNING, "channel '%s' timed-out during the T.38 negotiation.\n", chan->name);
1638                                 details->caps &= ~AST_FAX_TECH_T38;
1639                                 break;
1640                         }
1641
1642                         if (!(frame = ast_read(chan))) {
1643                                 ast_log(LOG_WARNING, "error on '%s' while waiting for T.38 negotiation.\n", chan->name);
1644                                 return -1;
1645                         }
1646
1647                         if ((frame->frametype == AST_FRAME_CONTROL) &&
1648                                         (frame->subclass.integer == AST_CONTROL_T38_PARAMETERS) &&
1649                                         (frame->datalen == sizeof(t38_parameters))) {
1650                                 struct ast_control_t38_parameters *parameters = frame->data.ptr;
1651
1652                                 switch (parameters->request_response) {
1653                                 case AST_T38_REQUEST_NEGOTIATE:
1654                                         t38_parameters_fax_to_ast(&t38_parameters, &details->our_t38_parameters);
1655                                         t38_parameters.request_response = AST_T38_NEGOTIATED;
1656                                         ast_indicate_data(chan, AST_CONTROL_T38_PARAMETERS, &t38_parameters, sizeof(t38_parameters));
1657                                         break;
1658                                 case AST_T38_NEGOTIATED:
1659                                         ast_log(LOG_NOTICE, "Negotiated T.38 for receive on %s\n", chan->name);
1660                                         t38_parameters_ast_to_fax(&details->their_t38_parameters, parameters);
1661                                         details->caps &= ~AST_FAX_TECH_AUDIO;
1662                                         report_fax_status(chan, details, "T.38 Negotiated");
1663                                         ms = 0;
1664                                         break;
1665                                 case AST_T38_REFUSED:
1666                                         ast_log(LOG_WARNING, "channel '%s' refused to negotiate T.38\n", chan->name);
1667                                         details->caps &= ~AST_FAX_TECH_T38;
1668                                         ms = 0;
1669                                         break;
1670                                 default:
1671                                         ast_log(LOG_ERROR, "channel '%s' failed to negotiate T.38\n", chan->name);
1672                                         details->caps &= ~AST_FAX_TECH_T38;
1673                                         ms = 0;
1674                                         break;
1675                                 }
1676                         }
1677                         ast_frfree(frame);
1678                 }
1679
1680                 /* if T.38 was negotiated, we are done initializing */
1681                 if (ast_channel_get_t38_state(chan) == T38_STATE_NEGOTIATED) {
1682                         return 0;
1683                 }
1684
1685                 /* send one more CNG tone to get audio going again for some
1686                  * carriers if we are going to fall back to audio mode */
1687                 if (details->option.allow_audio == AST_FAX_OPTFLAG_TRUE) {
1688                         if (ast_playtones_start(chan, 1024, "!1100/500,!0/3000", 1)) {
1689                                 ast_log(LOG_ERROR, "error generating second CNG tone on %s\n", chan->name);
1690                                 return -1;
1691                         }
1692
1693                         ms = 3500;
1694                         while (ms > 0) {
1695                                 ms = ast_waitfor(chan, ms);
1696                                 if (ms < 0) {
1697                                         ast_log(LOG_ERROR, "error while generating second CNG tone on %s\n", chan->name);
1698                                         ast_playtones_stop(chan);
1699                                         return -1;
1700                                 }
1701
1702                                 if (ms == 0) { /* all done, nothing happened */
1703                                         break;
1704                                 }
1705
1706                                 if (!(frame = ast_read(chan))) {
1707                                         ast_log(LOG_ERROR, "error reading frame while generating second CNG tone on %s\n", chan->name);
1708                                         ast_playtones_stop(chan);
1709                                         return -1;
1710                                 }
1711
1712                                 if ((frame->frametype == AST_FRAME_CONTROL) &&
1713                                                 (frame->subclass.integer == AST_CONTROL_T38_PARAMETERS) &&
1714                                                 (frame->datalen == sizeof(t38_parameters))) {
1715                                         struct ast_control_t38_parameters *parameters = frame->data.ptr;
1716
1717                                         switch (parameters->request_response) {
1718                                         case AST_T38_REQUEST_NEGOTIATE:
1719                                                 /* the other end has requested a switch to T.38, so reply that we are willing, if we can
1720                                                  * do T.38 as well
1721                                                  */
1722                                                 t38_parameters_fax_to_ast(&t38_parameters, &details->our_t38_parameters);
1723                                                 t38_parameters.request_response = (details->caps & AST_FAX_TECH_T38) ? AST_T38_NEGOTIATED : AST_T38_REFUSED;
1724                                                 ast_indicate_data(chan, AST_CONTROL_T38_PARAMETERS, &t38_parameters, sizeof(t38_parameters));
1725                                                 ast_playtones_stop(chan);
1726                                                 break;
1727                                         case AST_T38_NEGOTIATED:
1728                                                 ast_log(LOG_NOTICE, "Negotiated T.38 for send on %s\n", chan->name);
1729                                                 t38_parameters_ast_to_fax(&details->their_t38_parameters, parameters);
1730                                                 details->caps &= ~AST_FAX_TECH_AUDIO;
1731                                                 report_fax_status(chan, details, "T.38 Negotiated");
1732                                                 ms = 0;
1733                                                 break;
1734                                         default:
1735                                                 break;
1736                                         }
1737                                 }
1738                                 ast_frfree(frame);
1739                         }
1740
1741                         ast_playtones_stop(chan);
1742
1743                         /* if T.38 was negotiated, we are done initializing */
1744                         if (ast_channel_get_t38_state(chan) == T38_STATE_NEGOTIATED) {
1745                                 return 0;
1746                         }
1747                 }
1748         }
1749
1750         /* if we made it here, then T.38 failed, check the 'f' flag */
1751         if (details->option.allow_audio == AST_FAX_OPTFLAG_FALSE) {
1752                 ast_log(LOG_WARNING, "Audio FAX not allowed on channel '%s' and T.38 negotiation failed; aborting.\n", chan->name);
1753                 return -1;
1754         }
1755
1756         /* ok, audio fallback is allowed */
1757         details->caps |= AST_FAX_TECH_AUDIO;
1758
1759         return 0;
1760 }
1761
1762
1763 /*! \brief initiate a send FAX session */
1764 static int sendfax_exec(struct ast_channel *chan, const char *data)
1765 {
1766         char *parse, *filenames, *c;
1767         int channel_alive, file_count;
1768         struct ast_fax_session_details *details;
1769         struct ast_fax_document *doc;
1770         AST_DECLARE_APP_ARGS(args,
1771                 AST_APP_ARG(filenames);
1772                 AST_APP_ARG(options);
1773         );
1774         struct ast_flags opts = { 0, };
1775         struct manager_event_info info;
1776
1777         /* initialize output channel variables */
1778         pbx_builtin_setvar_helper(chan, "FAXSTATUS", "FAILED");
1779         pbx_builtin_setvar_helper(chan, "REMOTESTATIONID", NULL);
1780         pbx_builtin_setvar_helper(chan, "FAXPAGES", "0");
1781         pbx_builtin_setvar_helper(chan, "FAXBITRATE", NULL);
1782         pbx_builtin_setvar_helper(chan, "FAXRESOLUTION", NULL);
1783
1784         /* Get a requirement structure and set it.  This structure is used
1785          * to tell the FAX technology module about the higher level FAX session */
1786         if (!(details = find_or_create_details(chan))) {
1787                 pbx_builtin_setvar_helper(chan, "FAXERROR", "MEMORY_ERROR");
1788                 pbx_builtin_setvar_helper(chan, "FAXSTATUSSTRING", "error allocating memory");
1789                 ast_log(LOG_ERROR, "System cannot provide memory for session requirements.\n");
1790                 return -1;
1791         }
1792
1793         set_channel_variables(chan, details);
1794
1795         if (ast_strlen_zero(data)) {
1796                 ast_string_field_set(details, error, "INVALID_ARGUMENTS");
1797                 ast_string_field_set(details, resultstr, "invalid arguments");
1798                 set_channel_variables(chan, details);
1799                 ast_log(LOG_WARNING, "%s requires an argument (filename[&filename[&filename]][,options])\n", app_sendfax);
1800                 ao2_ref(details, -1);
1801                 return -1;
1802         }
1803         parse = ast_strdupa(data);
1804         AST_STANDARD_APP_ARGS(args, parse);
1805
1806
1807         if (!ast_strlen_zero(args.options) &&
1808             ast_app_parse_options(fax_exec_options, &opts, NULL, args.options)) {
1809                 ast_string_field_set(details, error, "INVALID_ARGUMENTS");
1810                 ast_string_field_set(details, resultstr, "invalid arguments");
1811                 set_channel_variables(chan, details);
1812                 ao2_ref(details, -1);
1813                 return -1;
1814         }
1815         if (ast_strlen_zero(args.filenames)) {
1816                 ast_string_field_set(details, error, "INVALID_ARGUMENTS");
1817                 ast_string_field_set(details, resultstr, "invalid arguments");
1818                 set_channel_variables(chan, details);
1819                 ast_log(LOG_WARNING, "%s requires an argument (filename[&filename[&filename]],options])\n", app_sendfax);
1820                 ao2_ref(details, -1);
1821                 return -1;
1822         }
1823         
1824         /* check for unsupported FAX application options */
1825         if (ast_test_flag(&opts, OPT_CALLERMODE) || ast_test_flag(&opts, OPT_CALLEDMODE)) {
1826                 ast_string_field_set(details, error, "INVALID_ARGUMENTS");
1827                 ast_string_field_set(details, resultstr, "invalid arguments");
1828                 set_channel_variables(chan, details);
1829                 ast_log(LOG_WARNING, "%s does not support polling\n", app_sendfax);
1830                 ao2_ref(details, -1);
1831                 return -1;
1832         }
1833
1834         /* make sure the channel is up */
1835         if (chan->_state != AST_STATE_UP) {
1836                 if (ast_answer(chan)) {
1837                         ast_log(LOG_WARNING, "Channel '%s' failed answer attempt.\n", chan->name);
1838                         ao2_ref(details, -1);
1839                         return -1;
1840                 }
1841         }
1842
1843         ast_atomic_fetchadd_int(&faxregistry.fax_tx_attempts, 1);
1844
1845         file_count = 0;
1846         filenames = args.filenames;
1847         while ((c = strsep(&filenames, "&"))) {
1848                 if (access(c, (F_OK | R_OK)) < 0) {
1849                         ast_string_field_set(details, error, "FILE_ERROR");
1850                         ast_string_field_set(details, resultstr, "error reading file");
1851                         set_channel_variables(chan, details);
1852                         ast_log(LOG_ERROR, "access failure.  Verify '%s' exists and check permissions.\n", args.filenames);
1853                         ao2_ref(details, -1);
1854                         return -1;
1855                 }
1856
1857                 if (!(doc = ast_calloc(1, sizeof(*doc) + strlen(c) + 1))) {
1858                         ast_string_field_set(details, error, "MEMORY_ERROR");
1859                         ast_string_field_set(details, resultstr, "error allocating memory");
1860                         set_channel_variables(chan, details);
1861                         ast_log(LOG_ERROR, "System cannot provide memory for session requirements.\n");
1862                         ao2_ref(details, -1);
1863                         return -1;
1864                 }
1865
1866                 strcpy(doc->filename, c);
1867                 AST_LIST_INSERT_TAIL(&details->documents, doc, next);
1868                 file_count++;
1869         }
1870
1871         if (file_count > 1) {
1872                 details->caps |= AST_FAX_TECH_MULTI_DOC;
1873         }
1874
1875         ast_verb(3, "Channel '%s' sending FAX:\n", chan->name);
1876         AST_LIST_TRAVERSE(&details->documents, doc, next) {
1877                 ast_verb(3, "   %s\n", doc->filename);
1878         }
1879
1880         details->caps = AST_FAX_TECH_SEND;
1881
1882         /* check for debug */
1883         if (ast_test_flag(&opts, OPT_DEBUG) || global_fax_debug) {
1884                 details->option.debug = AST_FAX_OPTFLAG_TRUE;
1885         }
1886
1887         /* check for request for status events */
1888         if (ast_test_flag(&opts, OPT_STATUS)) {
1889                 details->option.statusevents = AST_FAX_OPTFLAG_TRUE;
1890         }
1891
1892         if ((ast_channel_get_t38_state(chan) == T38_STATE_UNAVAILABLE) ||
1893             ast_test_flag(&opts, OPT_ALLOWAUDIO)) {
1894                 details->option.allow_audio = AST_FAX_OPTFLAG_TRUE;
1895         }
1896
1897         if (ast_test_flag(&opts, OPT_REQUEST_T38)) {
1898                 details->option.request_t38 = AST_FAX_OPTFLAG_TRUE;
1899         }
1900
1901         if (set_fax_t38_caps(chan, details)) {
1902                 ast_string_field_set(details, error, "T38_NEG_ERROR");
1903                 ast_string_field_set(details, resultstr, "error negotiating T.38");
1904                 set_channel_variables(chan, details);
1905                 ao2_ref(details, -1);
1906                 return -1;
1907         }
1908
1909         if (details->caps & AST_FAX_TECH_T38) {
1910                 if (sendfax_t38_init(chan, details)) {
1911                         ast_string_field_set(details, error, "T38_NEG_ERROR");
1912                         ast_string_field_set(details, resultstr, "error negotiating T.38");
1913                         set_channel_variables(chan, details);
1914                         ao2_ref(details, -1);
1915                         ast_log(LOG_ERROR, "error initializing channel '%s' in T.38 mode\n", chan->name);
1916                         return -1;
1917                 }
1918         } else {
1919                 details->option.send_cng = 1;
1920         }
1921
1922         if ((channel_alive = generic_fax_exec(chan, details)) < 0) {
1923                 ast_atomic_fetchadd_int(&faxregistry.fax_failures, 1);
1924         }
1925
1926         if (ast_channel_get_t38_state(chan) == T38_STATE_NEGOTIATED) {
1927                 if (disable_t38(chan)) {
1928                         ast_log(LOG_WARNING, "error disabling T.38 mode on %s\n", chan->name);
1929                 }
1930         }
1931
1932         if (!(filenames = generate_filenames_string(details, "FileName: ", "\r\n"))) {
1933                 ast_log(LOG_ERROR, "Error generating SendFAX manager event\n");
1934                 ao2_ref(details, -1);
1935                 return (!channel_alive) ? -1 : 0;
1936         }
1937
1938         /* send out the AMI completion event */
1939         ast_channel_lock(chan);
1940         get_manager_event_info(chan, &info);
1941         manager_event(EVENT_FLAG_CALL,
1942                       "SendFAX", 
1943                       "Channel: %s\r\n"
1944                       "Context: %s\r\n"
1945                       "Exten: %s\r\n"
1946                       "CallerID: %s\r\n"
1947                       "RemoteStationID: %s\r\n"
1948                       "LocalStationID: %s\r\n"
1949                       "PagesTransferred: %s\r\n"
1950                       "Resolution: %s\r\n"
1951                       "TransferRate: %s\r\n"
1952                       "%s\r\n",
1953                       chan->name,
1954                       info.context,
1955                       info.exten,
1956                       info.cid,
1957                       pbx_builtin_getvar_helper(chan, "REMOTESTATIONID"),
1958                       pbx_builtin_getvar_helper(chan, "LOCALSTATIONID"),
1959                       pbx_builtin_getvar_helper(chan, "FAXPAGES"),
1960                       pbx_builtin_getvar_helper(chan, "FAXRESOLUTION"),
1961                       pbx_builtin_getvar_helper(chan, "FAXBITRATE"),
1962                       filenames);
1963         ast_channel_unlock(chan);
1964
1965         ast_free(filenames);
1966
1967         ao2_ref(details, -1);
1968
1969         /* If the channel hungup return -1; otherwise, return 0 to continue in the dialplan */
1970         return (!channel_alive) ? -1 : 0;
1971 }
1972
1973 /*! \brief hash callback for ao2 */
1974 static int session_hash_cb(const void *obj, const int flags)
1975 {
1976         const struct ast_fax_session *s = obj;
1977
1978         return s->id;
1979 }
1980
1981 /*! \brief compare callback for ao2 */
1982 static int session_cmp_cb(void *obj, void *arg, int flags)
1983 {
1984         struct ast_fax_session *lhs = obj, *rhs = arg;
1985
1986         return (lhs->id == rhs->id) ? CMP_MATCH | CMP_STOP : 0;
1987 }
1988
1989 /*! \brief fax session tab completion */
1990 static char *fax_session_tab_complete(struct ast_cli_args *a)
1991 {
1992         int tklen;
1993         int wordnum = 0;
1994         char *name = NULL;
1995         struct ao2_iterator i;
1996         struct ast_fax_session *s;
1997         char tbuf[5];
1998
1999         if (a->pos != 3) {
2000                 return NULL;
2001         }
2002
2003         tklen = strlen(a->word);
2004         i = ao2_iterator_init(faxregistry.container, 0);
2005         while ((s = ao2_iterator_next(&i))) {
2006                 snprintf(tbuf, sizeof(tbuf), "%d", s->id);
2007                 if (!strncasecmp(a->word, tbuf, tklen) && ++wordnum > a->n) {
2008                         name = ast_strdup(tbuf);
2009                         ao2_ref(s, -1);
2010                         break;
2011                 }
2012                 ao2_ref(s, -1);
2013         }
2014         if (ao2_iterator_destroy != NULL) {
2015                 ao2_iterator_destroy(&i);
2016         }
2017         return name;
2018 }
2019
2020 static char *cli_fax_show_version(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
2021 {
2022         struct fax_module *fax;
2023
2024         switch(cmd) {
2025         case CLI_INIT:
2026                 e->command = "fax show version";
2027                 e->usage =
2028                         "Usage: fax show version\n"
2029                         "       Show versions of FAX For Asterisk components.\n";
2030                 return NULL;
2031         case CLI_GENERATE:
2032                 return NULL;
2033         }
2034
2035         if (a->argc != 3) {
2036                 return CLI_SHOWUSAGE;
2037         }
2038
2039         ast_cli(a->fd, "FAX For Asterisk Components:\n");
2040         ast_cli(a->fd, "\tApplications: %s\n", ast_get_version());
2041         AST_RWLIST_RDLOCK(&faxmodules);
2042         AST_RWLIST_TRAVERSE(&faxmodules, fax, list) {
2043                 ast_cli(a->fd, "\t%s: %s\n", fax->tech->description, fax->tech->version);
2044         }
2045         AST_RWLIST_UNLOCK(&faxmodules);
2046         ast_cli(a->fd, "\n");
2047
2048         return CLI_SUCCESS;
2049 }
2050
2051 /*! \brief enable FAX debugging */
2052 static char *cli_fax_set_debug(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
2053 {
2054         int flag;
2055         const char *what;
2056
2057         switch (cmd) {
2058         case CLI_INIT:
2059                 e->command = "fax set debug {on|off}";
2060                 e->usage = 
2061                         "Usage: fax set debug { on | off }\n"
2062                         "       Enable/Disable FAX debugging on new FAX sessions.  The basic FAX debugging will result in\n"
2063                         "       additional events sent to manager sessions with 'call' class permissions.  When\n"
2064                         "       verbosity is greater than '5' events will be displayed to the console and audio versus\n"
2065                         "       energy analysis will be performed and displayed to the console.\n";
2066                 return NULL;
2067         case CLI_GENERATE:
2068                 return NULL;
2069         }
2070
2071         what = a->argv[e->args-1];      /* guaranteed to exist */
2072         if (!strcasecmp(what, "on")) {
2073                 flag = 1;
2074         } else if (!strcasecmp(what, "off")) {
2075                 flag = 0;
2076         } else {
2077                 return CLI_SHOWUSAGE;
2078         }
2079
2080         global_fax_debug = flag;
2081         ast_cli(a->fd, "\n\nFAX Debug %s\n\n", (flag) ? "Enabled" : "Disabled");
2082
2083         return CLI_SUCCESS;
2084 }
2085
2086 /*! \brief display registered FAX capabilities */
2087 static char *cli_fax_show_capabilities(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
2088 {
2089         struct fax_module *fax;
2090         unsigned int num_modules = 0;
2091         
2092         switch (cmd) {
2093         case CLI_INIT:
2094                 e->command = "fax show capabilities";
2095                 e->usage = 
2096                         "Usage: fax show capabilities\n"
2097                         "       Shows the capabilities of the registered FAX technology modules\n";
2098                 return NULL;
2099         case CLI_GENERATE:
2100                 return NULL;
2101         }
2102
2103         ast_cli(a->fd, "\n\nRegistered FAX Technology Modules:\n\n");
2104         AST_RWLIST_RDLOCK(&faxmodules);
2105         AST_RWLIST_TRAVERSE(&faxmodules, fax, list) {
2106                 ast_cli(a->fd, "%-15s : %s\n%-15s : %s\n%-15s : ", "Type", fax->tech->type, "Description", fax->tech->description, "Capabilities");
2107                 fax->tech->cli_show_capabilities(a->fd);
2108                 num_modules++;
2109         }
2110         AST_RWLIST_UNLOCK(&faxmodules);
2111         ast_cli(a->fd, "%d registered modules\n\n", num_modules);
2112
2113         return CLI_SUCCESS;
2114 }
2115
2116 /*! \brief display global defaults and settings */
2117 static char *cli_fax_show_settings(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
2118 {
2119         struct fax_module *fax;
2120         char modems[128] = "";
2121
2122         switch (cmd) {
2123         case CLI_INIT:
2124                 e->command = "fax show settings";
2125                 e->usage =
2126                         "Usage: fax show settings\n"
2127                         "       Show the global settings and defaults of both the FAX core and technology modules\n";
2128                 return NULL;
2129         case CLI_GENERATE:
2130                 return NULL;
2131         }
2132
2133         ast_cli(a->fd, "FAX For Asterisk Settings:\n");
2134         ast_cli(a->fd, "\tECM: %s\n", general_options.ecm ? "Enabled" : "Disabled");
2135         ast_cli(a->fd, "\tStatus Events: %s\n",  general_options.statusevents ? "On" : "Off");
2136         ast_cli(a->fd, "\tMinimum Bit Rate: %d\n", general_options.minrate);
2137         ast_cli(a->fd, "\tMaximum Bit Rate: %d\n", general_options.maxrate);
2138         ast_fax_modem_to_str(general_options.modems, modems, sizeof(modems));
2139         ast_cli(a->fd, "\tModem Modulations Allowed: %s\n", modems);
2140         ast_cli(a->fd, "\n\nFAX Technology Modules:\n\n");
2141         AST_RWLIST_RDLOCK(&faxmodules);
2142         AST_RWLIST_TRAVERSE(&faxmodules, fax, list) {
2143                 ast_cli(a->fd, "%s (%s) Settings:\n", fax->tech->type, fax->tech->description);
2144                 fax->tech->cli_show_settings(a->fd);
2145         }
2146         AST_RWLIST_UNLOCK(&faxmodules);
2147
2148         return CLI_SUCCESS;
2149 }
2150
2151 /*! \brief display details of a specified fax session */
2152 static char *cli_fax_show_session(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
2153 {
2154         struct ast_fax_session *s, tmp;
2155
2156         switch (cmd) {
2157         case CLI_INIT:
2158                 e->command = "fax show session";
2159                 e->usage =
2160                         "Usage: fax show session <session number>\n"
2161                         "       Shows status of the named FAX session\n";
2162                 return NULL;
2163         case CLI_GENERATE:
2164                 return fax_session_tab_complete(a);
2165         }
2166
2167         if (a->argc != 4) {
2168                 return CLI_SHOWUSAGE;
2169         }
2170
2171         if (sscanf(a->argv[3], "%d", &tmp.id) != 1) {
2172                 ast_log(LOG_ERROR, "invalid session id: '%s'\n", a->argv[3]);
2173                 return RESULT_SUCCESS;
2174         }
2175
2176         ast_cli(a->fd, "\nFAX Session Details:\n--------------------\n\n");
2177         s = ao2_find(faxregistry.container, &tmp, OBJ_POINTER);
2178         if (s) {
2179                 s->tech->cli_show_session(s, a->fd);
2180                 ao2_ref(s, -1);
2181         }
2182         ast_cli(a->fd, "\n\n");
2183
2184         return CLI_SUCCESS;
2185 }
2186         
2187 /*! \brief display fax stats */
2188 static char *cli_fax_show_stats(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
2189 {
2190         struct fax_module *fax;
2191         
2192         switch (cmd) {
2193         case CLI_INIT:
2194                 e->command = "fax show stats";
2195                 e->usage =
2196                         "Usage: fax show stats\n"
2197                         "       Shows a statistical summary of FAX transmissions\n";
2198                 return NULL;
2199         case CLI_GENERATE:
2200                 return NULL;
2201         }
2202
2203         ast_cli(a->fd, "\nFAX Statistics:\n---------------\n\n");
2204         ast_cli(a->fd, "%-20.20s : %d\n", "Current Sessions", faxregistry.active_sessions);
2205         ast_cli(a->fd, "%-20.20s : %d\n", "Transmit Attempts", faxregistry.fax_tx_attempts);
2206         ast_cli(a->fd, "%-20.20s : %d\n", "Receive Attempts", faxregistry.fax_rx_attempts);
2207         ast_cli(a->fd, "%-20.20s : %d\n", "Completed FAXes", faxregistry.fax_complete);
2208         ast_cli(a->fd, "%-20.20s : %d\n", "Failed FAXes", faxregistry.fax_failures);
2209         AST_RWLIST_RDLOCK(&faxmodules);
2210         AST_RWLIST_TRAVERSE(&faxmodules, fax, list) {
2211                 fax->tech->cli_show_stats(a->fd);
2212         }
2213         AST_RWLIST_UNLOCK(&faxmodules);
2214         ast_cli(a->fd, "\n\n");
2215
2216         return CLI_SUCCESS;
2217 }
2218
2219 /*! \brief display fax sessions */
2220 static char *cli_fax_show_sessions(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
2221 {
2222         struct ast_fax_session *s;
2223         struct ao2_iterator i;
2224         int session_count;
2225         char *filenames;
2226
2227         switch (cmd) {
2228         case CLI_INIT:
2229                 e->command = "fax show sessions";
2230                 e->usage =
2231                         "Usage: fax show sessions\n"
2232                         "       Shows the current FAX sessions\n";
2233                 return NULL;
2234         case CLI_GENERATE:
2235                 return NULL;
2236         }
2237
2238         ast_cli(a->fd, "\nCurrent FAX Sessions:\n\n");
2239         ast_cli(a->fd, "%-20.20s %-10.10s %-10.10s %-5.5s %-10.10s %-15.15s %-30.30s\n",
2240                 "Channel", "Tech", "FAXID", "Type", "Operation", "State", "File(s)");
2241         i = ao2_iterator_init(faxregistry.container, 0);
2242         while ((s = ao2_iterator_next(&i))) {
2243                 ao2_lock(s);
2244
2245                 if (!(filenames = generate_filenames_string(s->details, "", ", "))) {
2246                         ast_log(LOG_ERROR, "error printing filenames for 'fax show sessions' command");
2247                         ao2_unlock(s);
2248                         ao2_ref(s, -1);
2249                         if (ao2_iterator_destroy != NULL) {
2250                                 ao2_iterator_destroy(&i);
2251                         }
2252                         return CLI_FAILURE;
2253                 }
2254
2255                 ast_cli(a->fd, "%-20.20s %-10.10s %-10d %-5.5s %-10.10s %-15.15s %-30s\n",
2256                         s->channame, s->tech->type, s->id,
2257                         (s->details->caps & AST_FAX_TECH_AUDIO) ? "G.711" : "T.38",
2258                         (s->details->caps & AST_FAX_TECH_SEND) ? "send" : "receive",
2259                         ast_fax_state_to_str(s->state), filenames);
2260
2261                 ast_free(filenames);
2262                 ao2_unlock(s);
2263                 ao2_ref(s, -1);
2264         }
2265         if (ao2_iterator_destroy != NULL) {
2266                 ao2_iterator_destroy(&i);
2267         }
2268         session_count = ao2_container_count(faxregistry.container);
2269         ast_cli(a->fd, "\n%d FAX sessions\n\n", session_count);
2270
2271         return CLI_SUCCESS;
2272 }
2273
2274 static struct ast_cli_entry fax_cli[] = {
2275         AST_CLI_DEFINE(cli_fax_show_version, "Show versions of FAX For Asterisk components"),
2276         AST_CLI_DEFINE(cli_fax_set_debug, "Enable/Disable FAX debugging on new FAX sessions"),
2277         AST_CLI_DEFINE(cli_fax_show_capabilities, "Show the capabilities of the registered FAX technology modules"),
2278         AST_CLI_DEFINE(cli_fax_show_settings, "Show the global settings and defaults of both the FAX core and technology modules"),
2279         AST_CLI_DEFINE(cli_fax_show_session, "Show the status of the named FAX sessions"),
2280         AST_CLI_DEFINE(cli_fax_show_sessions, "Show the current FAX sessions"),
2281         AST_CLI_DEFINE(cli_fax_show_stats, "Summarize FAX session history"),
2282 };
2283
2284 /*! \brief configure res_fax */
2285 static int set_config(const char *config_file)
2286 {
2287         struct ast_config *cfg;
2288         struct ast_variable *v;
2289         struct ast_flags config_flags = { 0 };
2290
2291         /* set defaults */      
2292         general_options.minrate = RES_FAX_MINRATE;
2293         general_options.maxrate = RES_FAX_MAXRATE;      
2294         general_options.statusevents = RES_FAX_STATUSEVENTS;
2295         general_options.modems = RES_FAX_MODEM;
2296         general_options.ecm = AST_FAX_OPTFLAG_TRUE;
2297
2298         /* read configuration */
2299         if (!(cfg = ast_config_load2(config_file, "res_fax", config_flags))) {
2300                 ast_log(LOG_NOTICE, "Configuration file '%s' not found, using default options.\n", config_file);
2301                 return 0;
2302         }
2303         if (cfg == CONFIG_STATUS_FILEUNCHANGED) {
2304                 ast_clear_flag(&config_flags, CONFIG_FLAG_FILEUNCHANGED);
2305                 cfg = ast_config_load2(config_file, "res_fax", config_flags);
2306         }
2307
2308         /* create configuration */
2309         for (v = ast_variable_browse(cfg, "general"); v; v = v->next) {
2310                 int rate;
2311
2312                 if (!strcasecmp(v->name, "minrate")) {
2313                         ast_debug(3, "reading minrate '%s' from configuration file\n", v->value);
2314                         if ((rate = fax_rate_str_to_int(v->value)) == 0) {
2315                                 ast_config_destroy(cfg);
2316                                 return -1;
2317                         }
2318                         general_options.minrate = rate;
2319                 } else if (!strcasecmp(v->name, "maxrate")) {
2320                         ast_debug(3, "reading maxrate '%s' from configuration file\n", v->value);
2321                         if ((rate = fax_rate_str_to_int(v->value)) == 0) {
2322                                 ast_config_destroy(cfg);
2323                                 return -1;
2324                         }
2325                         general_options.maxrate = rate;
2326                 } else if (!strcasecmp(v->name, "statusevents")) {
2327                         ast_debug(3, "reading statusevents '%s' from configuration file\n", v->value);
2328                         general_options.statusevents = ast_true(v->value);
2329                 } else if (!strcasecmp(v->name, "ecm")) {
2330                         ast_debug(3, "reading ecm '%s' from configuration file\n", v->value);
2331                         general_options.ecm = ast_true(v->value);
2332                 } else if ((!strcasecmp(v->name, "modem")) || (!strcasecmp(v->name, "modems"))) {
2333                         general_options.modems = 0;
2334                         update_modem_bits(&general_options.modems, v->value);
2335                 }
2336         }
2337
2338         ast_config_destroy(cfg);
2339
2340         return 0;
2341 }
2342
2343 /*! \brief FAXOPT read function returns the contents of a FAX option */
2344 static int acf_faxopt_read(struct ast_channel *chan, const char *cmd, char *data, char *buf, size_t len)
2345 {
2346         struct ast_fax_session_details *details = find_details(chan);
2347         int res = 0;
2348         char *filenames;
2349
2350         if (!details) {
2351                 ast_log(LOG_ERROR, "channel '%s' can't read FAXOPT(%s) because it has never been written.\n", chan->name, data);
2352                 return -1;
2353         }
2354         if (!strcasecmp(data, "ecm")) {
2355                 ast_copy_string(buf, details->option.ecm ? "yes" : "no", len);
2356         } else if (!strcasecmp(data, "error")) {
2357                 ast_copy_string(buf, details->error, len);
2358         } else if (!strcasecmp(data, "filename")) {
2359                 if (AST_LIST_EMPTY(&details->documents)) {
2360                         ast_log(LOG_ERROR, "channel '%s' can't read FAXOPT(%s) because it has never been written.\n", chan->name, data);
2361                         res = -1;
2362                 } else {
2363                         ast_copy_string(buf, AST_LIST_FIRST(&details->documents)->filename, len);
2364                 }
2365         } else if (!strcasecmp(data, "filenames")) {
2366                 if (AST_LIST_EMPTY(&details->documents)) {
2367                         ast_log(LOG_ERROR, "channel '%s' can't read FAXOPT(%s) because it has never been written.\n", chan->name, data);
2368                         res = -1;
2369                 } else if ((filenames = generate_filenames_string(details, "", ","))) {
2370                         ast_copy_string(buf, filenames, len);
2371                         ast_free(filenames);
2372                 } else {
2373                         ast_log(LOG_ERROR, "channel '%s' can't read FAXOPT(%s), there was an error generating the filenames list.\n", chan->name, data);
2374                         res = -1;
2375                 }
2376         } else if (!strcasecmp(data, "headerinfo")) {
2377                 ast_copy_string(buf, details->headerinfo, len);
2378         } else if (!strcasecmp(data, "localstationid")) {
2379                 ast_copy_string(buf, details->localstationid, len);
2380         } else if (!strcasecmp(data, "maxrate")) {
2381                 snprintf(buf, len, "%d", details->maxrate);
2382         } else if (!strcasecmp(data, "minrate")) {
2383                 snprintf(buf, len, "%d", details->minrate);
2384         } else if (!strcasecmp(data, "pages")) {
2385                 snprintf(buf, len, "%d", details->pages_transferred);
2386         } else if (!strcasecmp(data, "rate")) {
2387                 ast_copy_string(buf, details->transfer_rate, len);
2388         } else if (!strcasecmp(data, "remotestationid")) {
2389                 ast_copy_string(buf, details->remotestationid, len);
2390         } else if (!strcasecmp(data, "resolution")) {
2391                 ast_copy_string(buf, details->resolution, len);
2392         } else if (!strcasecmp(data, "sessionid")) {
2393                 snprintf(buf, len, "%d", details->id);
2394         } else if (!strcasecmp(data, "status")) {
2395                 ast_copy_string(buf, details->result, len);
2396         } else if (!strcasecmp(data, "statusstr")) {
2397                 ast_copy_string(buf, details->resultstr, len);
2398         } else if ((!strcasecmp(data, "modem")) || (!strcasecmp(data, "modems"))) {
2399                 ast_fax_modem_to_str(details->modems, buf, len);
2400         } else {
2401                 ast_log(LOG_WARNING, "channel '%s' can't read FAXOPT(%s) because it is unhandled!\n", chan->name, data);
2402                 res = -1;
2403         }
2404         ao2_ref(details, -1);
2405
2406         return res;
2407 }
2408
2409 /*! \brief FAXOPT write function modifies the contents of a FAX option */
2410 static int acf_faxopt_write(struct ast_channel *chan, const char *cmd, char *data, const char *value)
2411 {
2412         int res = 0;
2413         struct ast_fax_session_details *details;
2414
2415         if (!(details = find_or_create_details(chan))) {
2416                 ast_log(LOG_WARNING, "channel '%s' can't set FAXOPT(%s) to '%s' because it failed to create a datastore.\n", chan->name, data, value);
2417                 return -1;
2418         }
2419         ast_debug(3, "channel '%s' setting FAXOPT(%s) to '%s'\n", chan->name, data, value);
2420
2421         if (!strcasecmp(data, "ecm")) {
2422                 const char *val = ast_skip_blanks(value);
2423                 if (ast_true(val)) {
2424                         details->option.ecm = AST_FAX_OPTFLAG_TRUE;
2425                 } else if (ast_false(val)) {
2426                         details->option.ecm = AST_FAX_OPTFLAG_FALSE;
2427                 } else {
2428                         ast_log(LOG_WARNING, "Unsupported value '%s' passed to FAXOPT(ecm).\n", value);
2429                 }
2430         } else if (!strcasecmp(data, "headerinfo")) {
2431                 ast_string_field_set(details, headerinfo, value);
2432         } else if (!strcasecmp(data, "localstationid")) {
2433                 ast_string_field_set(details, localstationid, value);
2434         } else if (!strcasecmp(data, "maxrate")) {
2435                 details->maxrate = fax_rate_str_to_int(value);
2436                 if (!details->maxrate) {
2437                         details->maxrate = ast_fax_maxrate();
2438                 }
2439         } else if (!strcasecmp(data, "minrate")) {
2440                 details->minrate = fax_rate_str_to_int(value);
2441                 if (!details->minrate) {
2442                         details->minrate = ast_fax_minrate();
2443                 }
2444         } else if ((!strcasecmp(data, "modem")) || (!strcasecmp(data, "modems"))) {
2445                 update_modem_bits(&details->modems, value);
2446         } else {
2447                 ast_log(LOG_WARNING, "channel '%s' set FAXOPT(%s) to '%s' is unhandled!\n", chan->name, data, value);
2448                 res = -1;
2449         }
2450
2451         ao2_ref(details, -1);
2452
2453         return res;
2454 }
2455
2456 /*! \brief FAXOPT dialplan function */
2457 struct ast_custom_function acf_faxopt = {
2458         .name = "FAXOPT",
2459         .read = acf_faxopt_read,
2460         .write = acf_faxopt_write,
2461 };
2462
2463 /*! \brief unload res_fax */
2464 static int unload_module(void)
2465 {
2466         ast_cli_unregister_multiple(fax_cli, ARRAY_LEN(fax_cli));
2467         
2468         if (ast_custom_function_unregister(&acf_faxopt) < 0) {
2469                 ast_log(LOG_WARNING, "failed to unregister function '%s'\n", acf_faxopt.name);
2470         }
2471
2472         if (ast_unregister_application(app_sendfax) < 0) {
2473                 ast_log(LOG_WARNING, "failed to unregister '%s'\n", app_sendfax);
2474         }
2475
2476         if (ast_unregister_application(app_receivefax) < 0) {
2477                 ast_log(LOG_WARNING, "failed to unregister '%s'\n", app_receivefax);
2478         }
2479
2480         if (fax_logger_level != -1) {
2481                 ast_logger_unregister_level("FAX");
2482         }
2483
2484         ao2_ref(faxregistry.container, -1);
2485
2486         return 0;
2487 }
2488
2489 /*! \brief load res_fax */
2490 static int load_module(void)
2491 {
2492         int res;
2493
2494         /* initialize the registry */
2495         faxregistry.active_sessions = 0;
2496         if (!(faxregistry.container = ao2_container_alloc(FAX_MAXBUCKETS, session_hash_cb, session_cmp_cb))) {
2497                 return AST_MODULE_LOAD_DECLINE;
2498         }
2499         
2500         if (set_config(config) < 0) {
2501                 ast_log(LOG_ERROR, "failed to load configuration file '%s'\n", config);
2502                 ao2_ref(faxregistry.container, -1);
2503                 return AST_MODULE_LOAD_DECLINE;
2504         }
2505
2506         /* register CLI operations and applications */
2507         if (ast_register_application_xml(app_sendfax, sendfax_exec) < 0) {
2508                 ast_log(LOG_WARNING, "failed to register '%s'.\n", app_sendfax);
2509                 ao2_ref(faxregistry.container, -1);
2510                 return AST_MODULE_LOAD_DECLINE;
2511         }
2512         if (ast_register_application_xml(app_receivefax, receivefax_exec) < 0) {
2513                 ast_log(LOG_WARNING, "failed to register '%s'.\n", app_receivefax);
2514                 ast_unregister_application(app_sendfax);
2515                 ao2_ref(faxregistry.container, -1);
2516                 return AST_MODULE_LOAD_DECLINE;
2517         }
2518         ast_cli_register_multiple(fax_cli, ARRAY_LEN(fax_cli));
2519         res = ast_custom_function_register(&acf_faxopt);        
2520         fax_logger_level = ast_logger_register_level("FAX");
2521
2522         return res;
2523 }
2524
2525
2526 AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_GLOBAL_SYMBOLS | AST_MODFLAG_LOAD_ORDER, "Generic FAX Applications",
2527                 .load = load_module,
2528                 .unload = unload_module,
2529                 .load_pri = AST_MODPRI_APP_DEPEND,
2530                );