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/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	SPANDSP_EXPOSE_INTERNAL_STRUCTURES
#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, const char *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, const char *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 = AST_BUILDOPT_SUM, .load = load_module, .unload = unload_module, }
static const char	app_rcvfax_name [] = "ReceiveFAX"
static const char	app_sndfax_name [] = "SendFAX"
static struct ast_module_info *	ast_module_info = &__mod_info
static struct ast_generator	generator

---

Define Documentation

#define MAX_SAMPLES   240

Definition at line 148 of file app_fax.c.

Referenced by fax_generator_generate().

#define SPANDSP_EXPOSE_INTERNAL_STRUCTURES

Definition at line 34 of file app_fax.c.

#define WATCHDOG_STATE_TIMEOUT   5 * 60

Definition at line 157 of file app_fax.c.

Referenced by transmit_audio(), and transmit_t38().

#define WATCHDOG_TOTAL_TIMEOUT   30 * 60

Definition at line 156 of file app_fax.c.

Referenced by transmit_audio(), and transmit_t38().

---

Function Documentation

static void __reg_module

(

void

)

[static]

Definition at line 1008 of file app_fax.c.

static void __unreg_module

(

void

)

[static]

Definition at line 1008 of file app_fax.c.

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

Definition at line 326 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 331 of file app_fax.c.

References ast_channel_name(), ast_format_set(), AST_FORMAT_SLINEAR, AST_FRAME_SET_BUFFER, AST_FRAME_VOICE, AST_FRIENDLY_OFFSET, ast_log(), ast_write(), errno, ast_frame_subclass::format, ast_frame::frametype, LOG_WARNING, MAX_SAMPLES, ast_frame::samples, and ast_frame::subclass.

{
   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,
      .src = __FUNCTION__,
   };
   ast_format_set(&outf.subclass.format, AST_FORMAT_SLINEAR, 0);

   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", ast_channel_name(chan), strerror(errno));
         return -1;
      }
   }

   return 0;
}

static int load_module

(

void

)

[static]

Definition at line 991 of file app_fax.c.

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

{
   int res ;

   res = ast_register_application_xml(app_sndfax_name, sndfax_exec);
   res |= ast_register_application_xml(app_rcvfax_name, rcvfax_exec);

   /* 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 203 of file app_fax.c.

References ast_channel_name(), ast_debug, ast_log(), ast_manager_event, ast_channel::caller, fax_session::chan, ast_channel::connected, fax_session::direction, EVENT_FLAG_CALL, ast_channel::exten, fax_session::file_name, fax_session::finished, ast_party_connected_line::id, ast_party_caller::id, LOG_WARNING, ast_party_id::name, ast_party_id::number, pbx_builtin_setvar_helper(), S_COR, S_OR, ast_party_name::str, ast_party_number::str, ast_party_name::valid, and ast_party_number::valid.

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 = S_OR(t30_get_tx_ident(f), "");
   far_ident = S_OR(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);

   ast_manager_event(s->chan, EVENT_FLAG_CALL,
      s->direction ? "FaxSent" : "FaxReceived",
      "Channel: %s\r\n"
      "Exten: %s\r\n"
      "CallerID: %s\r\n"
      "CallerIDName: %s\r\n"
      "ConnectedLineNum: %s\r\n"
      "ConnectedLineName: %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",
      ast_channel_name(s->chan),
      s->chan->exten,
      S_COR(s->chan->caller.id.number.valid, s->chan->caller.id.number.str, ""),
      S_COR(s->chan->caller.id.name.valid, s->chan->caller.id.name.str, ""),
      S_COR(s->chan->connected.id.number.valid, s->chan->connected.id.number.str, ""),
      S_COR(s->chan->connected.id.name.valid, s->chan->connected.id.name.str, ""),
      far_ident,
      local_ident,
      pages_transferred,
      stat.y_resolution,
      stat.bit_rate,
      s->file_name);
}

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

Definition at line 912 of file app_fax.c.

References args, AST_APP_ARG, ast_channel_queryoption(), ast_channel_setoption(), AST_DECLARE_APP_ARGS, ast_log(), AST_OPTION_DIGIT_DETECT, AST_OPTION_FAX_DETECT, AST_STANDARD_APP_ARGS, ast_strdupa, ast_strlen_zero(), fax_session::caller_mode, fax_session::chan, fax_session::direction, dummy(), 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;
   char restore_digit_detect = 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, "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;

   /* get current digit detection mode, then disable digit detection if enabled */
   {
      int dummy = sizeof(restore_digit_detect);

      ast_channel_queryoption(chan, AST_OPTION_DIGIT_DETECT, &restore_digit_detect, &dummy, 0);
   }

   if (restore_digit_detect) {
      char new_digit_detect = 0;

      ast_channel_setoption(chan, AST_OPTION_DIGIT_DETECT, &new_digit_detect, sizeof(new_digit_detect), 0);
   }

   /* disable FAX tone detection if enabled */
   {
      char new_fax_detect = 0;

      ast_channel_setoption(chan, AST_OPTION_FAX_DETECT, &new_fax_detect, sizeof(new_fax_detect), 0);
   }

   res = transmit(&session);

   if (restore_digit_detect) {
      ast_channel_setoption(chan, AST_OPTION_DIGIT_DETECT, &restore_digit_detect, sizeof(restore_digit_detect), 0);
   }

   return res;
}

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

Definition at line 316 of file app_fax.c.

Referenced by spandsp_fax_start(), 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 308 of file app_fax.c.

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

Referenced by spandsp_fax_start(), 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 295 of file app_fax.c.

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

Referenced by spandsp_fax_start(), 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 285 of file app_fax.c.

References option_debug, and span_message().

Referenced by spandsp_fax_gateway_start(), spandsp_fax_new(), spandsp_fax_start(), 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,
		const char *	data
	)			[static]

Definition at line 843 of file app_fax.c.

References args, AST_APP_ARG, ast_channel_queryoption(), ast_channel_setoption(), AST_DECLARE_APP_ARGS, ast_log(), AST_OPTION_DIGIT_DETECT, AST_OPTION_FAX_DETECT, AST_STANDARD_APP_ARGS, ast_strdupa, ast_strlen_zero(), fax_session::caller_mode, fax_session::chan, fax_session::direction, dummy(), 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, };
   char restore_digit_detect = 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;

   /* get current digit detection mode, then disable digit detection if enabled */
   {
      int dummy = sizeof(restore_digit_detect);

      ast_channel_queryoption(chan, AST_OPTION_DIGIT_DETECT, &restore_digit_detect, &dummy, 0);
   }

   if (restore_digit_detect) {
      char new_digit_detect = 0;

      ast_channel_setoption(chan, AST_OPTION_DIGIT_DETECT, &new_digit_detect, sizeof(new_digit_detect), 0);
   }

   /* disable FAX tone detection if enabled */
   {
      char new_fax_detect = 0;

      ast_channel_setoption(chan, AST_OPTION_FAX_DETECT, &new_fax_detect, sizeof(new_fax_detect), 0);
   }

   res = transmit(&session);

   if (restore_digit_detect) {
      ast_channel_setoption(chan, AST_OPTION_DIGIT_DETECT, &restore_digit_detect, sizeof(restore_digit_detect), 0);
   }

   return res;
}

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

Definition at line 169 of file app_fax.c.

References ast_debug, ast_log(), 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_debug(1, "%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 180 of file app_fax.c.

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

Referenced by spandsp_fax_gateway_start(), spandsp_fax_new(), and transmit_t38().

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

   struct ast_frame outf = {
      .frametype = AST_FRAME_MODEM,
      .subclass.integer = 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 785 of file app_fax.c.

References ast_channel::_state, ast_answer(), ast_channel_get_t38_state(), ast_channel_name(), 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", "0");
   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", ast_channel_name(s->chan));
         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 369 of file app_fax.c.

References ast_activate_generator(), ast_channel_get_t38_state(), ast_channel_name(), AST_CONTROL_T38_PARAMETERS, ast_deactivate_generator(), ast_debug, ast_format_clear(), ast_format_copy(), AST_FORMAT_SLINEAR, AST_FRAME_CONTROL, AST_FRAME_VOICE, ast_frfree, ast_indicate_data(), ast_log(), ast_read(), ast_set_read_format(), ast_set_read_format_by_id(), ast_set_write_format(), ast_set_write_format_by_id(), AST_T38_NEGOTIATED, AST_T38_RATE_14400, 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, FALSE, fax_session::finished, ast_frame_subclass::format, ast_frame::frametype, ast_format::id, ast_frame_subclass::integer, 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;
   struct ast_format original_read_fmt;
   struct ast_format original_write_fmt;
   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_14400,
                          .rate_management = AST_T38_RATE_MANAGEMENT_TRANSFERRED_TCF,
                          .fill_bit_removal = 1,
/*
 * spandsp has API calls to support MMR and JBIG transcoding, but they aren't
 * implemented quite yet... so don't offer them to the remote endpoint
 *                        .transcoding_mmr = 1,
 *                        .transcoding_jbig = 1,
*/
   };

   ast_format_clear(&original_read_fmt);
   ast_format_clear(&original_write_fmt);

   /* if in called party mode, try to use T.38 */
   if (s->caller_mode == FALSE) {
      /* 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", ast_channel_name(s->chan));
         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", ast_channel_name(s->chan));
               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", ast_channel_name(s->chan));
                  break;
               }
            }
            if (!(inf = ast_read(s->chan))) {
               return -1;
            }
            if ((inf->frametype == AST_FRAME_CONTROL) &&
                (inf->subclass.integer == 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", ast_channel_name(s->chan));
                  res = 1;
                  break;
               case AST_T38_REFUSED:
                  ast_log(LOG_WARNING, "channel '%s' refused to negotiate T.38\n", ast_channel_name(s->chan));
                  break;
               default:
                  ast_log(LOG_ERROR, "channel '%s' failed to negotiate T.38\n", ast_channel_name(s->chan));
                  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

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

   ast_format_copy(&original_write_fmt, &s->chan->writeformat);
   if (original_write_fmt.id != AST_FORMAT_SLINEAR) {
      res = ast_set_write_format_by_id(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) {
      inf = NULL;

      if ((res = ast_waitfor(s->chan, 25)) < 0) {
         ast_debug(1, "Error waiting for a frame\n");
         break;
      }

      /* 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;
      }

      if (!res) {
         /* There was timeout waiting for a frame. Loop around and wait again */
         continue;
      }

      /* There is a frame available. Get it */
      res = 0;

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

      ast_debug(10, "frame %d/%u, len=%d\n", inf->frametype, (unsigned int) inf->subclass.format.id, 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 channel format
         to slinear so it will still be received by ast_read */
      if (inf->frametype == AST_FRAME_VOICE && inf->subclass.format.id == 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;
         }
         if (last_state != t30state->state) {
            state_change = ast_tvnow();
            last_state = t30state->state;
         }
      } else if ((inf->frametype == AST_FRAME_CONTROL) &&
            (inf->subclass.integer == 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;
   }

   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.id != 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", ast_channel_name(s->chan));
   }

   if (original_read_fmt.id != 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", ast_channel_name(s->chan));
   }

   return res;

}

static int transmit_t38

(

fax_session *

s

)

[static]

Definition at line 609 of file app_fax.c.

References ast_channel_get_t38_state(), ast_channel_name(), AST_CONTROL_T38_PARAMETERS, ast_debug, AST_FRAME_CONTROL, AST_FRAME_MODEM, ast_frfree, ast_indicate_data(), ast_log(), AST_MODEM_T38, ast_read(), AST_T38_REFUSED, AST_T38_REQUEST_TERMINATE, 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, disable_t38(), FALSE, ast_control_t38_parameters::fill_bit_removal, fax_session::finished, ast_frame::frametype, ast_frame_subclass::integer, LOG_ERROR, 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, T38_STATE_NEGOTIATED, 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");
      res = -1;
      goto disable_t38;
   }

   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) {
      inf = NULL;

      if ((res = ast_waitfor(s->chan, 25)) < 0) {
         ast_debug(1, "Error waiting for a frame\n");
         break;
      }

      last_frame = now;

      /* 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;
      }

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

      if (!res) {
         /* There was timeout waiting for a frame. Loop around and wait again */
         continue;
      }

      /* There is a frame available. Get it */
      res = 0;

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

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

      if (inf->frametype == AST_FRAME_MODEM && inf->subclass.integer == AST_MODEM_T38) {
         t38_core_rx_ifp_packet(t38state, inf->data.ptr, inf->datalen, inf->seqno);
         if (last_state != t30state->state) {
            state_change = ast_tvnow();
            last_state = t30state->state;
         }
      } else if (inf->frametype == AST_FRAME_CONTROL && inf->subclass.integer == 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;
   }

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

   if (inf)
      ast_frfree(inf);

   t30_terminate(t30state);
   t38_terminal_release(&t38);

disable_t38:
   /* if we are not the caller, it's our job to shut down the T.38
    * session when the FAX transmisson is complete.
    */
   if ((s->caller_mode == FALSE) &&
       (ast_channel_get_t38_state(s->chan) == T38_STATE_NEGOTIATED)) {
      struct ast_control_t38_parameters t38_parameters = { .request_response = AST_T38_REQUEST_TERMINATE, };

      if (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, "Shutting down T.38 on %s\n", ast_channel_name(s->chan));
         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", ast_channel_name(s->chan));
               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 shutdown.\n", ast_channel_name(s->chan));
                  break;
               }
            }
            if (!(inf = ast_read(s->chan))) {
               return -1;
            }
            if ((inf->frametype == AST_FRAME_CONTROL) &&
                (inf->subclass.integer == 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_TERMINATED:
                  ast_debug(1, "Shut down T.38 on %s\n", ast_channel_name(s->chan));
                  break;
               case AST_T38_REFUSED:
                  ast_log(LOG_WARNING, "channel '%s' refused to disable T.38\n", ast_channel_name(s->chan));
                  break;
               default:
                  ast_log(LOG_ERROR, "channel '%s' failed to disable T.38\n", ast_channel_name(s->chan));
                  break;
               }
               ast_frfree(inf);
               break;
            }
            ast_frfree(inf);
         }
      }
   }

   return res;
}

static int unload_module

(

void

)

[static]

Definition at line 981 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 = AST_BUILDOPT_SUM, .load = load_module, .unload = unload_module, } [static]

Definition at line 1008 of file app_fax.c.

const char app_rcvfax_name[] = "ReceiveFAX" [static]

Definition at line 146 of file app_fax.c.

const char app_sndfax_name[] = "SendFAX" [static]

Definition at line 145 of file app_fax.c.

struct ast_module_info* ast_module_info = &__mod_info [static]

Definition at line 1008 of file app_fax.c.

struct ast_generator generator [static]

Initial value:

 {
   alloc:      fax_generator_alloc,
   generate:   fax_generator_generate,
}

Definition at line 361 of file app_fax.c.

Referenced by cli_alias_passthrough().