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/stasis.h"
#include "asterisk/stasis_channels.h"
#include "asterisk/format_cache.h"

Include dependency graph for app_fax.c:

Go to the source code of this file.

Data Structures
struct	fax_session

Macros
#define	ASTMM_LIBC   ASTMM_IGNORE
#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)
struct ast_module *	AST_MODULE_SELF_SYM (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 = "30ef0c93b36035ec78c9cfd712d36d9b" , .support_level = AST_MODULE_SUPPORT_DEPRECATED, .load = load_module, .unload = unload_module, }
static const char	app_rcvfax_name [] = "ReceiveFAX"
static const char	app_sndfax_name [] = "SendFAX"
static const struct ast_module_info *	ast_module_info = &__mod_info
static struct ast_generator	generator

Macro Definition Documentation

ASTMM_LIBC

#define ASTMM_LIBC   ASTMM_IGNORE

Definition at line 24 of file app_fax.c.

MAX_SAMPLES

#define MAX_SAMPLES   240

Definition at line 151 of file app_fax.c.

Referenced by fax_generator_generate().

SPANDSP_EXPOSE_INTERNAL_STRUCTURES

#define SPANDSP_EXPOSE_INTERNAL_STRUCTURES

Definition at line 35 of file app_fax.c.

WATCHDOG_STATE_TIMEOUT

#define WATCHDOG_STATE_TIMEOUT   5 * 60

Definition at line 160 of file app_fax.c.

Referenced by transmit_audio(), and transmit_t38().

WATCHDOG_TOTAL_TIMEOUT

#define WATCHDOG_TOTAL_TIMEOUT   30 * 60

Definition at line 159 of file app_fax.c.

Referenced by transmit_audio(), and transmit_t38().

Function Documentation

__reg_module()

static void __reg_module ( void  )

static

Definition at line 1003 of file app_fax.c.

__unreg_module()

static void __unreg_module ( void  )

static

Definition at line 1003 of file app_fax.c.

AST_MODULE_SELF_SYM()

struct ast_module* AST_MODULE_SELF_SYM

(

void

)

Definition at line 1003 of file app_fax.c.

fax_generator_alloc()

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

static

Definition at line 324 of file app_fax.c.

{
   return params;
}

fax_generator_generate()

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

static

Definition at line 329 of file app_fax.c.

References ast_channel_name(), ast_format_slin, AST_FRAME_SET_BUFFER, AST_FRAME_VOICE, AST_FRIENDLY_OFFSET, ast_log, ast_write(), buf, errno, ast_frame::frametype, len(), 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.format = ast_format_slin,
      .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", ast_channel_name(chan), strerror(errno));
         return -1;
      }
   }

   return 0;
}

load_module()

static int load_module ( void  )

static

Definition at line 985 of file app_fax.c.

References app_rcvfax_name, app_sndfax_name, AST_MODFLAG_DEFAULT, AST_MODULE_INFO(), AST_MODULE_SUPPORT_DEPRECATED, ast_register_application_xml, ASTERISK_GPL_KEY, NULL, rcvfax_exec(), sndfax_exec(), and unload_module().

{
   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;
}

phase_e_handler()

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

static

Definition at line 206 of file app_fax.c.

References ao2_cleanup, ast_channel_blob_create_from_cache(), ast_channel_fax_type(), ast_channel_topic(), ast_channel_uniqueid(), ast_debug, ast_json_pack(), ast_json_ref(), ast_json_unref(), AST_JSON_UTF8_VALIDATE, ast_log, buf, fax_session::chan, fax_session::direction, fax_session::file_name, fax_session::finished, LOG_WARNING, NULL, pbx_builtin_setvar_helper(), RAII_VAR, S_OR, and stasis_publish().

Referenced by transmit_audio(), and transmit_t38().

{
   RAII_VAR(struct ast_json *, json_object, NULL, ast_json_unref);
   RAII_VAR(struct ast_json *, json_filenames, NULL, ast_json_unref);
   RAII_VAR(struct stasis_message *, message, NULL, ao2_cleanup);
   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);

   json_filenames = ast_json_pack("[s]", s->file_name);
   if (!json_filenames) {
      return;
   }
   ast_json_ref(json_filenames);
   json_object = ast_json_pack("{s: s, s: s, s: s, s: i, s: i, s: i, s: o}",
      "type", s->direction ? "send" : "receive",
      "remote_station_id", AST_JSON_UTF8_VALIDATE(far_ident),
      "local_station_id", AST_JSON_UTF8_VALIDATE(local_ident),
      "fax_pages", pages_transferred,
      "fax_resolution", stat.y_resolution,
      "fax_bitrate", stat.bit_rate,
      "filenames", json_filenames);
   message = ast_channel_blob_create_from_cache(ast_channel_uniqueid(s->chan), ast_channel_fax_type(), json_object);
   if (!message) {
      return;
   }
   stasis_publish(ast_channel_topic(s->chan), message);
}

rcvfax_exec()

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

static

Definition at line 906 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, NULL, options, parse(), session, 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;
}

set_ecm()

static void set_ecm ( t30_state_t *  state, int  ecm  )

static

Definition at line 314 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);
}

set_file()

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

static

Definition at line 306 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);
}

set_local_info()

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

static

Definition at line 293 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);
}

set_logging()

static int set_logging ( logging_state_t *  state )

static

Definition at line 283 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;
}

sndfax_exec()

static int sndfax_exec ( struct ast_channel *  chan, const char *  data  )

static

Definition at line 837 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, NULL, options, parse(), session, 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;
}

span_message()

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

static

Definition at line 172 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);
   }
}

t38_tx_packet_handler()

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 183 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 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;
}

transmit()

static int transmit ( fax_session *  s )

static

Definition at line 779 of file app_fax.c.

References 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, NULL, 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 (ast_channel_state(s->chan) != 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;
}

transmit_audio()

static int transmit_audio ( fax_session *  s )

static

Definition at line 367 of file app_fax.c.

References ao2_bump, ao2_ref, ast_activate_generator(), ast_channel_get_t38_state(), ast_channel_name(), ast_channel_readformat(), ast_channel_writeformat(), AST_CONTROL_T38_PARAMETERS, ast_deactivate_generator(), ast_debug, ast_format_cmp(), AST_FORMAT_CMP_EQUAL, ast_format_get_name(), ast_format_slin, 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_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, done, FALSE, fax_session::finished, ast_frame_subclass::format, ast_frame::frametype, ast_frame_subclass::integer, LOG_ERROR, LOG_WARNING, NULL, phase_e_handler(), ast_frame::ptr, 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, timeout, TRUE, ast_control_t38_parameters::version, WATCHDOG_STATE_TIMEOUT, and WATCHDOG_TOTAL_TIMEOUT.

Referenced by transmit().

{
   int res = -1;
   struct ast_format *original_read_fmt;
   struct ast_format *original_write_fmt = NULL;
   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,
*/
   };

   /* 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

    original_read_fmt = ao2_bump(ast_channel_readformat(s->chan));
   res = ast_set_read_format(s->chan, ast_format_slin);
   if (res < 0) {
      ast_log(LOG_WARNING, "Unable to set to linear read mode, giving up\n");
      goto done;
   }

   original_write_fmt = ao2_bump(ast_channel_writeformat(s->chan));
   res = ast_set_write_format(s->chan, ast_format_slin);
   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/%s, len=%d\n", inf->frametype, ast_format_get_name(inf->subclass.format), 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 &&
         (ast_format_cmp(inf->subclass.format, ast_format_slin) == AST_FORMAT_CMP_EQUAL)) {
         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) {
      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));
      ao2_ref(original_write_fmt, -1);
   }

   if (original_read_fmt) {
      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));
      ao2_ref(original_read_fmt, -1);
   }

   return res;

}

transmit_t38()

static int transmit_t38 ( fax_session *  s )

static

Definition at line 603 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, NULL, 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, timeout, 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;
}

unload_module()

static int unload_module ( void  )

static

Definition at line 975 of file app_fax.c.

References app_rcvfax_name, app_sndfax_name, and ast_unregister_application().

Referenced by load_module().

{
   int res;

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

   return res;
}

Variable Documentation

__mod_info

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 = "30ef0c93b36035ec78c9cfd712d36d9b" , .support_level = AST_MODULE_SUPPORT_DEPRECATED, .load = load_module, .unload = unload_module, }

static

Definition at line 1003 of file app_fax.c.

app_rcvfax_name

const char app_rcvfax_name[] = "ReceiveFAX"

static

Definition at line 149 of file app_fax.c.

Referenced by load_module(), and unload_module().

app_sndfax_name

const char app_sndfax_name[] = "SendFAX"

static

Definition at line 148 of file app_fax.c.

Referenced by load_module(), and unload_module().

ast_module_info

const struct ast_module_info* ast_module_info = &__mod_info

static

Definition at line 1003 of file app_fax.c.

generator

struct ast_generator generator

static

Initial value:

= {
   .alloc = fax_generator_alloc,
   .generate = fax_generator_generate,
}

Definition at line 359 of file app_fax.c.

Referenced by ast_read_generator_actions(), ast_sip_pubsub_generate_body_content(), cli_alias_passthrough(), create_virtual_subscriptions(), deactivate_generator_nolock(), find_body_generator(), generator_write_format_change(), pubsub_on_rx_subscribe_request(), and sub_persistence_recreate().