app_fax.c File Reference

#include "asterisk.h"
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <inttypes.h>
#include <pthread.h>
#include <errno.h>
#include <tiffio.h>
#include <spandsp.h>
#include <spandsp/expose.h>
#include <spandsp/version.h>
#include "asterisk/lock.h"
#include "asterisk/file.h"
#include "asterisk/logger.h"
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/app.h"
#include "asterisk/dsp.h"
#include "asterisk/module.h"
#include "asterisk/manager.h"

Include dependency graph for app_fax.c:

Go to the source code of this file.

Data Structures
struct	fax_session
Defines
#define	MAX_SAMPLES   240
#define	WATCHDOG_STATE_TIMEOUT   5 * 60
#define	WATCHDOG_TOTAL_TIMEOUT   30 * 60
Functions
static void	__reg_module (void)
static void	__unreg_module (void)
static void *	fax_generator_alloc (struct ast_channel *chan, void *params)
static int	fax_generator_generate (struct ast_channel *chan, void *data, int len, int samples)
static int	load_module (void)
static void	phase_e_handler (t30_state_t *f, void *user_data, int result)
static int	rcvfax_exec (struct ast_channel *chan, void *data)
static void	set_ecm (t30_state_t *state, int ecm)
static void	set_file (t30_state_t *state, fax_session *s)
static void	set_local_info (t30_state_t *state, fax_session *s)
static int	set_logging (logging_state_t *state)
static int	sndfax_exec (struct ast_channel *chan, void *data)
static void	span_message (int level, const char *msg)
static int	t38_tx_packet_handler (t38_core_state_t *s, void *user_data, const uint8_t *buf, int len, int count)
static int	transmit (fax_session *s)
static int	transmit_audio (fax_session *s)
static int	transmit_t38 (fax_session *s)
static int	unload_module (void)
Variables
static struct ast_module_info	__mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_DEFAULT , .description = "Simple FAX Application" , .key = "This paragraph is copyright (c) 2006 by Digium, Inc. \In order for your module to load, it must return this \key via a function called \"key\". Any code which \includes this paragraph must be licensed under the GNU \General Public License version 2 or later (at your \option). In addition to Digium's general reservations \of rights, Digium expressly reserves the right to \allow other parties to license this paragraph under \different terms. Any use of Digium, Inc. trademarks or \logos (including \"Asterisk\" or \"Digium\") without \express written permission of Digium, Inc. is prohibited.\n" , .buildopt_sum = "a9c98e5d177805051735cb5b0b16b0a0" , .load = load_module, .unload = unload_module, }
static char *	app_rcvfax_desc
static char *	app_rcvfax_name = "ReceiveFAX"
static char *	app_rcvfax_synopsis = "Receive a FAX"
static char *	app_sndfax_desc
static char *	app_sndfax_name = "SendFAX"
static char *	app_sndfax_synopsis = "Send a FAX"
static struct ast_module_info *	ast_module_info = &__mod_info
struct ast_generator	generator

---

Define Documentation

#define MAX_SAMPLES   240

Definition at line 102 of file app_fax.c.

Referenced by fax_generator_generate().

#define WATCHDOG_STATE_TIMEOUT   5 * 60

Definition at line 111 of file app_fax.c.

Referenced by transmit_audio(), and transmit_t38().

#define WATCHDOG_TOTAL_TIMEOUT   30 * 60

Definition at line 110 of file app_fax.c.

Referenced by transmit_audio(), and transmit_t38().

---

Function Documentation

static void __reg_module

(

void

)

[static]

Definition at line 829 of file app_fax.c.

static void __unreg_module

(

void

)

[static]

Definition at line 829 of file app_fax.c.

static void* fax_generator_alloc	(	struct ast_channel *	chan,
		void *	params
	)			[static]

Definition at line 274 of file app_fax.c.

{
   return params;
}

static int fax_generator_generate	(	struct ast_channel *	chan,
		void *	data,
		int	len,
		int	samples
	)			[static]

Definition at line 279 of file app_fax.c.

References AST_FORMAT_SLINEAR, AST_FRAME_SET_BUFFER, AST_FRAME_VOICE, AST_FRIENDLY_OFFSET, ast_log(), ast_write(), buf, errno, ast_frame::frametype, LOG_WARNING, MAX_SAMPLES, and ast_frame::samples.

{
   fax_state_t *fax = (fax_state_t*) data;
   uint8_t buffer[AST_FRIENDLY_OFFSET + MAX_SAMPLES * sizeof(uint16_t)];
   int16_t *buf = (int16_t *) (buffer + AST_FRIENDLY_OFFSET);
    
   struct ast_frame outf = {
      .frametype = AST_FRAME_VOICE,
      .subclass = AST_FORMAT_SLINEAR,
      .src = __FUNCTION__,
   };

   if (samples > MAX_SAMPLES) {
      ast_log(LOG_WARNING, "Only generating %d samples, where %d requested\n", MAX_SAMPLES, samples);
      samples = MAX_SAMPLES;
   }
   
   if ((len = fax_tx(fax, buf, samples)) > 0) {
      outf.samples = len;
      AST_FRAME_SET_BUFFER(&outf, buffer, AST_FRIENDLY_OFFSET, len * sizeof(int16_t));

      if (ast_write(chan, &outf) < 0) {
         ast_log(LOG_WARNING, "Failed to write frame to '%s': %s\n", chan->name, strerror(errno));
         return -1;
      }
   }

   return 0;
}

static int load_module

(

void

)

[static]

Definition at line 812 of file app_fax.c.

References ast_register_application, rcvfax_exec(), and sndfax_exec().

{
   int res ;

   res = ast_register_application(app_sndfax_name, sndfax_exec, app_sndfax_synopsis, app_sndfax_desc);
   res |= ast_register_application(app_rcvfax_name, rcvfax_exec, app_rcvfax_synopsis, app_rcvfax_desc);

   /* The default SPAN message handler prints to stderr. It is something we do not want */
   span_set_message_handler(NULL);

   return res;
}

static void phase_e_handler	(	t30_state_t *	f,
		void *	user_data,
		int	result
	)			[static]

Definition at line 157 of file app_fax.c.

References ast_debug, ast_log(), buf, fax_session::chan, ast_channel::cid, ast_callerid::cid_num, fax_session::direction, EVENT_FLAG_CALL, ast_channel::exten, fax_session::file_name, fax_session::finished, LOG_WARNING, manager_event, pbx_builtin_setvar_helper(), s, and S_OR.

Referenced by transmit_audio(), and transmit_t38().

{
   const char *local_ident;
   const char *far_ident;
   char buf[20];
   fax_session *s = (fax_session *) user_data;
   t30_stats_t stat;
   int pages_transferred;

   ast_debug(1, "Fax phase E handler. result=%d\n", result);

   t30_get_transfer_statistics(f, &stat);

   s = (fax_session *) user_data;

   if (result != T30_ERR_OK) {
      s->finished = -1;

      /* FAXSTATUS is already set to FAILED */
      pbx_builtin_setvar_helper(s->chan, "FAXERROR", t30_completion_code_to_str(result));

      ast_log(LOG_WARNING, "Error transmitting fax. result=%d: %s.\n", result, t30_completion_code_to_str(result));

      return;
   }
   
   s->finished = 1; 
   
   local_ident = t30_get_tx_ident(f);
   far_ident = t30_get_rx_ident(f);
   pbx_builtin_setvar_helper(s->chan, "FAXSTATUS", "SUCCESS"); 
   pbx_builtin_setvar_helper(s->chan, "FAXERROR", NULL); 
   pbx_builtin_setvar_helper(s->chan, "REMOTESTATIONID", far_ident);
#if SPANDSP_RELEASE_DATE >= 20090220
   pages_transferred = (s->direction) ? stat.pages_tx : stat.pages_rx;
#else
   pages_transferred = stat.pages_transferred;
#endif
   snprintf(buf, sizeof(buf), "%d", pages_transferred);
   pbx_builtin_setvar_helper(s->chan, "FAXPAGES", buf);
   snprintf(buf, sizeof(buf), "%d", stat.y_resolution);
   pbx_builtin_setvar_helper(s->chan, "FAXRESOLUTION", buf);
   snprintf(buf, sizeof(buf), "%d", stat.bit_rate);
   pbx_builtin_setvar_helper(s->chan, "FAXBITRATE", buf); 
   
   ast_debug(1, "Fax transmitted successfully.\n");
   ast_debug(1, "  Remote station ID: %s\n", far_ident);
   ast_debug(1, "  Pages transferred: %d\n", pages_transferred);
   ast_debug(1, "  Image resolution:  %d x %d\n", stat.x_resolution, stat.y_resolution);
   ast_debug(1, "  Transfer Rate:     %d\n", stat.bit_rate);
   
   manager_event(EVENT_FLAG_CALL,
            s->direction ? "FaxSent" : "FaxReceived", 
            "Channel: %s\r\n"
            "Exten: %s\r\n"
            "CallerID: %s\r\n"
            "RemoteStationID: %s\r\n"
            "LocalStationID: %s\r\n"
            "PagesTransferred: %d\r\n"
            "Resolution: %d\r\n"
            "TransferRate: %d\r\n"
            "FileName: %s\r\n",
            s->chan->name,
            s->chan->exten,
            S_OR(s->chan->cid.cid_num, ""),
            far_ident,
            local_ident,
            pages_transferred,
            stat.y_resolution,
            stat.bit_rate,
            s->file_name);
}

static int rcvfax_exec	(	struct ast_channel *	chan,
		void *	data
	)			[static]

Definition at line 758 of file app_fax.c.

References AST_APP_ARG, AST_DECLARE_APP_ARGS, ast_log(), AST_STANDARD_APP_ARGS, ast_strdupa, ast_strlen_zero(), fax_session::caller_mode, fax_session::chan, fax_session::direction, FALSE, fax_session::file_name, fax_session::finished, LOG_ERROR, parse(), transmit(), and TRUE.

Referenced by load_module().

{
   int res = 0;
   char *parse;
   fax_session session;

   AST_DECLARE_APP_ARGS(args,
      AST_APP_ARG(file_name);
      AST_APP_ARG(options);
   );

   if (chan == NULL) {
      ast_log(LOG_ERROR, "Fax channel is NULL. Giving up.\n");
      return -1;
   }

   /* The next few lines of code parse out the filename and header from the input string */
   if (ast_strlen_zero(data)) {
      /* No data implies no filename or anything is present */
      ast_log(LOG_ERROR, "ReceiveFAX requires an argument (filename)\n");
      return -1;
   }

   parse = ast_strdupa(data);
   AST_STANDARD_APP_ARGS(args, parse);
   
   session.caller_mode = FALSE;

   if (args.options) {
      if (strchr(args.options, 'c'))
         session.caller_mode = TRUE;
   }

   /* Done parsing */
   session.direction = 0;
   session.file_name = args.file_name;
   session.chan = chan;
   session.finished = 0;

   res = transmit(&session);

   return res;
}

static void set_ecm	(	t30_state_t *	state,
		int	ecm
	)			[static]

Definition at line 264 of file app_fax.c.

Referenced by transmit_audio(), and transmit_t38().

{
   t30_set_ecm_capability(state, ecm);
   t30_set_supported_compressions(state, T30_SUPPORT_T4_1D_COMPRESSION | T30_SUPPORT_T4_2D_COMPRESSION | T30_SUPPORT_T6_COMPRESSION);
}

static void set_file	(	t30_state_t *	state,
		fax_session *	s
	)			[static]

Definition at line 256 of file app_fax.c.

References fax_session::direction, and fax_session::file_name.

Referenced by transmit_audio(), and transmit_t38().

{
   if (s->direction)
      t30_set_tx_file(state, s->file_name, -1, -1);
   else
      t30_set_rx_file(state, s->file_name, -1);
}

static void set_local_info	(	t30_state_t *	state,
		fax_session *	s
	)			[static]

Definition at line 243 of file app_fax.c.

References ast_strlen_zero(), fax_session::chan, and pbx_builtin_getvar_helper().

Referenced by transmit_audio(), and transmit_t38().

{
   const char *x;

   x = pbx_builtin_getvar_helper(s->chan, "LOCALSTATIONID");
   if (!ast_strlen_zero(x))
      t30_set_tx_ident(state, x);

   x = pbx_builtin_getvar_helper(s->chan, "LOCALHEADERINFO");
   if (!ast_strlen_zero(x))
      t30_set_tx_page_header_info(state, x);
}

static int set_logging

(

logging_state_t *

state

)

[static]

Definition at line 233 of file app_fax.c.

References option_debug, and span_message().

Referenced by transmit_audio(), and transmit_t38().

{
   int level = SPAN_LOG_WARNING + option_debug;

   span_log_set_message_handler(state, span_message);
   span_log_set_level(state, SPAN_LOG_SHOW_SEVERITY | SPAN_LOG_SHOW_PROTOCOL | level); 

   return 0;
}

static int sndfax_exec	(	struct ast_channel *	chan,
		void *	data
	)			[static]

Definition at line 714 of file app_fax.c.

References AST_APP_ARG, AST_DECLARE_APP_ARGS, ast_log(), AST_STANDARD_APP_ARGS, ast_strdupa, ast_strlen_zero(), fax_session::caller_mode, fax_session::chan, fax_session::direction, FALSE, fax_session::file_name, fax_session::finished, LOG_ERROR, parse(), transmit(), and TRUE.

Referenced by load_module().

{
   int res = 0;
   char *parse;
   fax_session session = { 0, };

   AST_DECLARE_APP_ARGS(args,
      AST_APP_ARG(file_name);
      AST_APP_ARG(options);
   );

   if (chan == NULL) {
      ast_log(LOG_ERROR, "Fax channel is NULL. Giving up.\n");
      return -1;
   }

   /* The next few lines of code parse out the filename and header from the input string */
   if (ast_strlen_zero(data)) {
      /* No data implies no filename or anything is present */
      ast_log(LOG_ERROR, "SendFAX requires an argument (filename)\n");
      return -1;
   }

   parse = ast_strdupa(data);
   AST_STANDARD_APP_ARGS(args, parse);
   
   session.caller_mode = TRUE;

   if (args.options) {
      if (strchr(args.options, 'a'))
         session.caller_mode = FALSE;
   }

   /* Done parsing */
   session.direction = 1;
   session.file_name = args.file_name;
   session.chan = chan;
   session.finished = 0;

   res = transmit(&session);

   return res;
}

static void span_message	(	int	level,
		const char *	msg
	)			[static]

Definition at line 123 of file app_fax.c.

References ast_log(), LOG_DEBUG, LOG_ERROR, and LOG_WARNING.

Referenced by set_logging().

{
   if (level == SPAN_LOG_ERROR) {
      ast_log(LOG_ERROR, "%s", msg);
   } else if (level == SPAN_LOG_WARNING) {
      ast_log(LOG_WARNING, "%s", msg);
   } else {
      ast_log(LOG_DEBUG, "%s", msg);
   }
}

static int t38_tx_packet_handler	(	t38_core_state_t *	s,
		void *	user_data,
		const uint8_t *	buf,
		int	len,
		int	count
	)			[static]

Definition at line 134 of file app_fax.c.

References AST_FRAME_MODEM, AST_FRAME_SET_BUFFER, ast_log(), AST_MODEM_T38, ast_write(), chan, errno, ast_frame::frametype, and LOG_WARNING.

Referenced by transmit_t38().

{
   struct ast_channel *chan = (struct ast_channel *) user_data;

   struct ast_frame outf = {
      .frametype = AST_FRAME_MODEM,
      .subclass = AST_MODEM_T38,
      .src = __FUNCTION__,
   };

   /* TODO: Asterisk does not provide means of resending the same packet multiple
     times so count is ignored at the moment */

   AST_FRAME_SET_BUFFER(&outf, buf, 0, len);

   if (ast_write(chan, &outf) < 0) {
      ast_log(LOG_WARNING, "Unable to write frame to channel; %s\n", strerror(errno));
      return -1;
   }

   return 0;
}

static int transmit

(

fax_session *

s

)

[static]

Definition at line 656 of file app_fax.c.

References ast_channel::_state, ast_answer(), ast_channel_get_t38_state(), ast_debug, ast_log(), AST_STATE_UP, fax_session::chan, fax_session::finished, LOG_ERROR, LOG_WARNING, pbx_builtin_setvar_helper(), T38_STATE_NEGOTIATED, fax_session::t38state, transmit_audio(), and transmit_t38().

Referenced by rcvfax_exec(), and sndfax_exec().

{
   int res = 0;

   /* Clear all channel variables which to be set by the application.
      Pre-set status to error so in case of any problems we can just leave */
   pbx_builtin_setvar_helper(s->chan, "FAXSTATUS", "FAILED"); 
   pbx_builtin_setvar_helper(s->chan, "FAXERROR", "Channel problems"); 

   pbx_builtin_setvar_helper(s->chan, "FAXMODE", NULL);
   pbx_builtin_setvar_helper(s->chan, "REMOTESTATIONID", NULL);
   pbx_builtin_setvar_helper(s->chan, "FAXPAGES", NULL);
   pbx_builtin_setvar_helper(s->chan, "FAXRESOLUTION", NULL);
   pbx_builtin_setvar_helper(s->chan, "FAXBITRATE", NULL); 

   if (s->chan->_state != AST_STATE_UP) {
      /* Shouldn't need this, but checking to see if channel is already answered
       * Theoretically asterisk should already have answered before running the app */
      res = ast_answer(s->chan);
      if (res) {
         ast_log(LOG_WARNING, "Could not answer channel '%s'\n", s->chan->name);
         return res;
      }
   }

   s->t38state = ast_channel_get_t38_state(s->chan);
   if (s->t38state != T38_STATE_NEGOTIATED) {
      /* T38 is not negotiated on the channel yet. First start regular transmission. If it switches to T38, follow */   
      pbx_builtin_setvar_helper(s->chan, "FAXMODE", "audio"); 
      res = transmit_audio(s);
      if (res > 0) {
         /* transmit_audio reports switchover to T38. Update t38state */
         s->t38state = ast_channel_get_t38_state(s->chan);
         if (s->t38state != T38_STATE_NEGOTIATED) {
            ast_log(LOG_ERROR, "Audio loop reports T38 switchover but t38state != T38_STATE_NEGOTIATED\n");
         }
      }
   }

   if (s->t38state == T38_STATE_NEGOTIATED) {
      pbx_builtin_setvar_helper(s->chan, "FAXMODE", "T38"); 
      res = transmit_t38(s);
   }

   if (res) {
      ast_log(LOG_WARNING, "Transmission error\n");
      res = -1;
   } else if (s->finished < 0) {
      ast_log(LOG_WARNING, "Transmission failed\n");
   } else if (s->finished > 0) {
      ast_debug(1, "Transmission finished Ok\n");
   }

   return res;
}

static int transmit_audio

(

fax_session *

s

)

[static]

Definition at line 317 of file app_fax.c.

References ast_activate_generator(), ast_channel_get_t38_state(), AST_CONTROL_T38_PARAMETERS, ast_deactivate_generator(), ast_debug, AST_FORMAT_SLINEAR, AST_FRAME_CONTROL, AST_FRAME_VOICE, ast_frfree, ast_indicate_data(), ast_log(), ast_read(), ast_set_read_format(), ast_set_write_format(), AST_T38_NEGOTIATED, AST_T38_RATE_9600, AST_T38_RATE_MANAGEMENT_TRANSFERRED_TCF, AST_T38_REFUSED, AST_T38_REQUEST_NEGOTIATE, ast_tvdiff_sec(), ast_tvnow(), ast_waitfor(), fax_session::caller_mode, fax_session::chan, ast_frame::data, ast_frame::datalen, fax_session::direction, fax_session::finished, ast_frame::frametype, LOG_ERROR, LOG_WARNING, phase_e_handler(), ast_frame::ptr, ast_channel::readformat, ast_control_t38_parameters::request_response, ast_frame::samples, set_ecm(), set_file(), set_local_info(), set_logging(), ast_frame::subclass, T38_STATE_NEGOTIATED, T38_STATE_UNAVAILABLE, fax_session::t38parameters, TRUE, ast_control_t38_parameters::version, WATCHDOG_STATE_TIMEOUT, WATCHDOG_TOTAL_TIMEOUT, and ast_channel::writeformat.

Referenced by transmit().

{
   int res = -1;
   int original_read_fmt = AST_FORMAT_SLINEAR;
   int original_write_fmt = AST_FORMAT_SLINEAR;
   fax_state_t fax;
   t30_state_t *t30state;
   struct ast_frame *inf = NULL;
   int last_state = 0;
   struct timeval now, start, state_change;
   enum ast_t38_state t38_state;
   struct ast_control_t38_parameters t38_parameters = { .version = 0,
                          .max_ifp = 800,
                          .rate = AST_T38_RATE_9600,
                          .rate_management = AST_T38_RATE_MANAGEMENT_TRANSFERRED_TCF,
                          .fill_bit_removal = 1,
                          .transcoding_mmr = 1,
                          .transcoding_jbig = 1,
   };

   /* if in receive mode, try to use T.38 */
   if (!s->direction) {
      /* check if we are already in T.38 mode (unlikely), or if we can request
       * a switch... if so, request it now and wait for the result, rather
       * than starting an audio FAX session that will have to be cancelled
       */
      if ((t38_state = ast_channel_get_t38_state(s->chan)) == T38_STATE_NEGOTIATED) {
         return 1;
      } else if ((t38_state != T38_STATE_UNAVAILABLE) &&
            (t38_parameters.request_response = AST_T38_REQUEST_NEGOTIATE,
             (ast_indicate_data(s->chan, AST_CONTROL_T38_PARAMETERS, &t38_parameters, sizeof(t38_parameters)) == 0))) {
         /* wait up to five seconds for negotiation to complete */
         unsigned int timeout = 5000;
         int ms;
         
         ast_debug(1, "Negotiating T.38 for receive on %s\n", s->chan->name);
         while (timeout > 0) {
            ms = ast_waitfor(s->chan, 1000);
            if (ms < 0) {
               ast_log(LOG_WARNING, "something bad happened while channel '%s' was polling.\n", s->chan->name);
               return -1;
            }
            if (!ms) {
               /* nothing happened */
               if (timeout > 0) {
                  timeout -= 1000;
                  continue;
               } else {
                  ast_log(LOG_WARNING, "channel '%s' timed-out during the T.38 negotiation.\n", s->chan->name);
                  break;
               }
            }
            if (!(inf = ast_read(s->chan))) {
               return -1;
            }
            if ((inf->frametype == AST_FRAME_CONTROL) &&
                (inf->subclass == AST_CONTROL_T38_PARAMETERS) &&
                (inf->datalen == sizeof(t38_parameters))) {
               struct ast_control_t38_parameters *parameters = inf->data.ptr;
               
               switch (parameters->request_response) {
               case AST_T38_NEGOTIATED:
                  ast_debug(1, "Negotiated T.38 for receive on %s\n", s->chan->name);
                  res = 1;
                  break;
               case AST_T38_REFUSED:
                  ast_log(LOG_WARNING, "channel '%s' refused to negotiate T.38\n", s->chan->name);
                  break;
               default:
                  ast_log(LOG_ERROR, "channel '%s' failed to negotiate T.38\n", s->chan->name);
                  break;
               }
               ast_frfree(inf);
               if (res == 1) {
                  return 1;
               } else {
                  break;
               }
            }
            ast_frfree(inf);
         }
      }
   }

#if SPANDSP_RELEASE_DATE >= 20080725
        /* for spandsp shaphots 0.0.6 and higher */
        t30state = &fax.t30;
#else
        /* for spandsp release 0.0.5 */
        t30state = &fax.t30_state;
#endif

   original_read_fmt = s->chan->readformat;
   if (original_read_fmt != AST_FORMAT_SLINEAR) {
      res = ast_set_read_format(s->chan, AST_FORMAT_SLINEAR);
      if (res < 0) {
         ast_log(LOG_WARNING, "Unable to set to linear read mode, giving up\n");
         goto done;
      }
   }

   original_write_fmt = s->chan->writeformat;
   if (original_write_fmt != AST_FORMAT_SLINEAR) {
      res = ast_set_write_format(s->chan, AST_FORMAT_SLINEAR);
      if (res < 0) {
         ast_log(LOG_WARNING, "Unable to set to linear write mode, giving up\n");
         goto done;
      }
   }

   /* Initialize T30 terminal */
   fax_init(&fax, s->caller_mode);

   /* Setup logging */
   set_logging(&fax.logging);
   set_logging(&t30state->logging);

   /* Configure terminal */
   set_local_info(t30state, s);
   set_file(t30state, s);
   set_ecm(t30state, TRUE);

   fax_set_transmit_on_idle(&fax, TRUE);

   t30_set_phase_e_handler(t30state, phase_e_handler, s);

   start = state_change = ast_tvnow();

   ast_activate_generator(s->chan, &generator, &fax);

   while (!s->finished) {
      res = ast_waitfor(s->chan, 20);
      if (res < 0)
         break;
      else if (res > 0)
         res = 0;

      inf = ast_read(s->chan);
      if (inf == NULL) {
         ast_debug(1, "Channel hangup\n");
         res = -1;
         break;
      }

      ast_debug(10, "frame %d/%d, len=%d\n", inf->frametype, inf->subclass, inf->datalen);

      /* Check the frame type. Format also must be checked because there is a chance
         that a frame in old format was already queued before we set chanel format
         to slinear so it will still be received by ast_read */
      if (inf->frametype == AST_FRAME_VOICE && inf->subclass == AST_FORMAT_SLINEAR) {
         if (fax_rx(&fax, inf->data.ptr, inf->samples) < 0) {
            /* I know fax_rx never returns errors. The check here is for good style only */
            ast_log(LOG_WARNING, "fax_rx returned error\n");
            res = -1;
            break;
         }

         /* Watchdog */
         if (last_state != t30state->state) {
            state_change = ast_tvnow();
            last_state = t30state->state;
         }
      } else if ((inf->frametype == AST_FRAME_CONTROL) &&
            (inf->subclass == AST_CONTROL_T38_PARAMETERS)) {
         struct ast_control_t38_parameters *parameters = inf->data.ptr;

         if (parameters->request_response == AST_T38_NEGOTIATED) {
            /* T38 switchover completed */
            s->t38parameters = *parameters;
            ast_debug(1, "T38 negotiated, finishing audio loop\n");
            res = 1;
            break;
         } else if (parameters->request_response == AST_T38_REQUEST_NEGOTIATE) {
            t38_parameters.request_response = AST_T38_NEGOTIATED;
            ast_debug(1, "T38 request received, accepting\n");
            /* Complete T38 switchover */
            ast_indicate_data(s->chan, AST_CONTROL_T38_PARAMETERS, &t38_parameters, sizeof(t38_parameters));
            /* Do not break audio loop, wait until channel driver finally acks switchover
             * with AST_T38_NEGOTIATED
             */
         }
      }

      ast_frfree(inf);
      inf = NULL;

      /* Watchdog */
      now = ast_tvnow();
      if (ast_tvdiff_sec(now, start) > WATCHDOG_TOTAL_TIMEOUT || ast_tvdiff_sec(now, state_change) > WATCHDOG_STATE_TIMEOUT) {
         ast_log(LOG_WARNING, "It looks like we hung. Aborting.\n");
         res = -1;
         break;
      }
   }

   ast_debug(1, "Loop finished, res=%d\n", res);

   if (inf)
      ast_frfree(inf);

   ast_deactivate_generator(s->chan);

   /* If we are switching to T38, remove phase E handler. Otherwise it will be executed
      by t30_terminate, display diagnostics and set status variables although no transmittion
      has taken place yet. */
   if (res > 0) {
      t30_set_phase_e_handler(t30state, NULL, NULL);
   }

   t30_terminate(t30state);
   fax_release(&fax);

done:
   if (original_write_fmt != AST_FORMAT_SLINEAR) {
      if (ast_set_write_format(s->chan, original_write_fmt) < 0)
         ast_log(LOG_WARNING, "Unable to restore write format on '%s'\n", s->chan->name);
   }

   if (original_read_fmt != AST_FORMAT_SLINEAR) {
      if (ast_set_read_format(s->chan, original_read_fmt) < 0)
         ast_log(LOG_WARNING, "Unable to restore read format on '%s'\n", s->chan->name);
   }

   return res;

}

static int transmit_t38

(

fax_session *

s

)

[static]

Definition at line 544 of file app_fax.c.

References AST_CONTROL_T38_PARAMETERS, ast_debug, AST_FRAME_CONTROL, AST_FRAME_MODEM, ast_frfree, ast_log(), AST_MODEM_T38, ast_read(), AST_T38_TERMINATED, ast_tvdiff_sec(), ast_tvdiff_us(), ast_tvnow(), ast_waitfor(), fax_session::caller_mode, fax_session::chan, ast_frame::data, ast_frame::datalen, ast_control_t38_parameters::fill_bit_removal, fax_session::finished, ast_frame::frametype, LOG_WARNING, ast_control_t38_parameters::max_ifp, phase_e_handler(), ast_frame::ptr, ast_control_t38_parameters::request_response, ast_frame::seqno, set_ecm(), set_file(), set_local_info(), set_logging(), ast_frame::subclass, t38_tx_packet_handler(), fax_session::t38parameters, ast_control_t38_parameters::transcoding_jbig, ast_control_t38_parameters::transcoding_mmr, TRUE, WATCHDOG_STATE_TIMEOUT, and WATCHDOG_TOTAL_TIMEOUT.

Referenced by transmit().

{
   int res = 0;
   t38_terminal_state_t t38;
   struct ast_frame *inf = NULL;
   int last_state = 0;
   struct timeval now, start, state_change, last_frame;
   t30_state_t *t30state;
   t38_core_state_t *t38state;

#if SPANDSP_RELEASE_DATE >= 20080725
   /* for spandsp shaphots 0.0.6 and higher */
   t30state = &t38.t30;
   t38state = &t38.t38_fe.t38;
#else
   /* for spandsp releases 0.0.5 */
   t30state = &t38.t30_state;
   t38state = &t38.t38;
#endif

   /* Initialize terminal */
   memset(&t38, 0, sizeof(t38));
   if (t38_terminal_init(&t38, s->caller_mode, t38_tx_packet_handler, s->chan) == NULL) {
      ast_log(LOG_WARNING, "Unable to start T.38 termination.\n");
      return -1;
   }

   t38_set_max_datagram_size(t38state, s->t38parameters.max_ifp);

   if (s->t38parameters.fill_bit_removal) {
      t38_set_fill_bit_removal(t38state, TRUE);
   }
   if (s->t38parameters.transcoding_mmr) {
      t38_set_mmr_transcoding(t38state, TRUE);
   }
   if (s->t38parameters.transcoding_jbig) {
      t38_set_jbig_transcoding(t38state, TRUE);
   }

   /* Setup logging */
   set_logging(&t38.logging);
   set_logging(&t30state->logging);
   set_logging(&t38state->logging);

   /* Configure terminal */
   set_local_info(t30state, s);
   set_file(t30state, s);
   set_ecm(t30state, TRUE);

   t30_set_phase_e_handler(t30state, phase_e_handler, s);

   now = start = state_change = ast_tvnow();

   while (!s->finished) {

      res = ast_waitfor(s->chan, 20);
      if (res < 0)
         break;
      else if (res > 0)
         res = 0;

      last_frame = now;
      now = ast_tvnow();
      t38_terminal_send_timeout(&t38, ast_tvdiff_us(now, last_frame) / (1000000 / 8000));

      inf = ast_read(s->chan);
      if (inf == NULL) {
         ast_debug(1, "Channel hangup\n");
         res = -1;
         break;
      }

      ast_debug(10, "frame %d/%d, len=%d\n", inf->frametype, inf->subclass, inf->datalen);

      if (inf->frametype == AST_FRAME_MODEM && inf->subclass == AST_MODEM_T38) {
         t38_core_rx_ifp_packet(t38state, inf->data.ptr, inf->datalen, inf->seqno);

         /* Watchdog */
         if (last_state != t30state->state) {
            state_change = ast_tvnow();
            last_state = t30state->state;
         }
      } else if (inf->frametype == AST_FRAME_CONTROL && inf->subclass == AST_CONTROL_T38_PARAMETERS) {
         struct ast_control_t38_parameters *parameters = inf->data.ptr;
         if (parameters->request_response == AST_T38_TERMINATED) {
            ast_debug(1, "T38 down, finishing\n");
            break;
         }
      }

      ast_frfree(inf);
      inf = NULL;

      /* Watchdog */
      if (ast_tvdiff_sec(now, start) > WATCHDOG_TOTAL_TIMEOUT || ast_tvdiff_sec(now, state_change) > WATCHDOG_STATE_TIMEOUT) {
         ast_log(LOG_WARNING, "It looks like we hung. Aborting.\n");
         res = -1;
         break;
      }
   }

   ast_debug(1, "Loop finished, res=%d\n", res);

   if (inf)
      ast_frfree(inf);

   t30_terminate(t30state);
   t38_terminal_release(&t38);

   return res;
}

static int unload_module

(

void

)

[static]

Definition at line 802 of file app_fax.c.

References ast_unregister_application().

{
   int res;

   res = ast_unregister_application(app_sndfax_name); 
   res |= ast_unregister_application(app_rcvfax_name);   

   return res;
}

---

Variable Documentation

struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_DEFAULT , .description = "Simple FAX Application" , .key = "This paragraph is copyright (c) 2006 by Digium, Inc. \In order for your module to load, it must return this \key via a function called \"key\". Any code which \includes this paragraph must be licensed under the GNU \General Public License version 2 or later (at your \option). In addition to Digium's general reservations \of rights, Digium expressly reserves the right to \allow other parties to license this paragraph under \different terms. Any use of Digium, Inc. trademarks or \logos (including \"Asterisk\" or \"Digium\") without \express written permission of Digium, Inc. is prohibited.\n" , .buildopt_sum = "a9c98e5d177805051735cb5b0b16b0a0" , .load = load_module, .unload = unload_module, } [static]

Definition at line 829 of file app_fax.c.

char* app_rcvfax_desc [static]

Definition at line 76 of file app_fax.c.

char* app_rcvfax_name = "ReceiveFAX" [static]

Definition at line 74 of file app_fax.c.

char* app_rcvfax_synopsis = "Receive a FAX" [static]

Definition at line 75 of file app_fax.c.

char* app_sndfax_desc [static]

Definition at line 49 of file app_fax.c.

char* app_sndfax_name = "SendFAX" [static]

Definition at line 47 of file app_fax.c.

char* app_sndfax_synopsis = "Send a FAX" [static]

Definition at line 48 of file app_fax.c.

struct ast_module_info* ast_module_info = &__mod_info [static]

Definition at line 829 of file app_fax.c.

struct ast_generator generator

Initial value:

 {
   alloc:      fax_generator_alloc,
   generate:   fax_generator_generate,
}

Definition at line 309 of file app_fax.c.