app_externalivr.c File Reference

External IVR application interface. More...

#include "asterisk.h"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <signal.h>
#include "asterisk/lock.h"
#include "asterisk/file.h"
#include "asterisk/logger.h"
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/module.h"
#include "asterisk/linkedlists.h"
#include "asterisk/app.h"
#include "asterisk/utils.h"
#include "asterisk/options.h"

Include dependency graph for app_externalivr.c:

Go to the source code of this file.

Data Structures
struct	gen_state
struct	ivr_localuser
struct	playlist_entry
Defines
#define	ast_chan_log(level, channel, format,...)   ast_log(level, "%s: " format, channel->name , ## __VA_ARGS__)
Functions
static int	app_exec (struct ast_channel *chan, void *data)
	AST_MODULE_INFO_STANDARD (ASTERISK_GPL_KEY,"External IVR Interface Application")
static void *	gen_alloc (struct ast_channel *chan, void *params)
static void	gen_closestream (struct gen_state *state)
static int	gen_generate (struct ast_channel *chan, void *data, int len, int samples)
static int	gen_nextfile (struct gen_state *state)
static struct ast_frame *	gen_readframe (struct gen_state *state)
static void	gen_release (struct ast_channel *chan, void *data)
static int	load_module (void)
static struct playlist_entry *	make_entry (const char *filename)
static void	send_child_event (FILE *handle, const char event, const char *data, const struct ast_channel *chan)
static int	unload_module (void)
Variables
static const char *	app = "ExternalIVR"
static const char *	descrip
static struct ast_generator	gen
static const char *	synopsis = "Interfaces with an external IVR application"

---

Detailed Description

External IVR application interface.

Author:

Kevin P. Fleming <kpfleming@digium.com>

Note:

Portions taken from the file-based music-on-hold work created by Anthony Minessale II in res_musiconhold.c

Definition in file app_externalivr.c.

---

Define Documentation

#define ast_chan_log	(	level,
		channel,
		format,
		...		)	ast_log(level, "%s: " format, channel->name , ## __VA_ARGS__)

Definition at line 71 of file app_externalivr.c.

Referenced by app_exec(), gen_generate(), gen_nextfile(), and send_child_event().

---

Function Documentation

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

Definition at line 243 of file app_externalivr.c.

References ast_channel::_state, ast_activate_generator(), ast_answer(), ast_app_separate_args(), ast_chan_log, ast_check_hangup(), AST_CONTROL_HANGUP, ast_deactivate_generator(), ast_fileexists(), AST_FLAG_ZOMBIE, AST_FRAME_CONTROL, AST_FRAME_DTMF, ast_frfree, AST_LIST_EMPTY, AST_LIST_HEAD_INIT_VALUE, AST_LIST_INSERT_TAIL, AST_LIST_LOCK, AST_LIST_REMOVE_HEAD, AST_LIST_UNLOCK, ast_log(), ast_module_user_add, ast_module_user_remove, ast_opt_high_priority, ast_read(), ast_set_priority(), AST_STATE_UP, ast_strdupa, ast_strlen_zero(), ast_test_flag, ast_waitfor_nandfds(), ivr_localuser::chan, errno, f, ast_frame::frametype, free, gen, input(), LOG_DEBUG, LOG_NOTICE, LOG_WARNING, make_entry(), send_child_event(), and ast_frame::subclass.

{
   struct ast_module_user *lu;
   struct playlist_entry *entry;
   const char *args = data;
   int child_stdin[2] = { 0,0 };
   int child_stdout[2] = { 0,0 };
   int child_stderr[2] = { 0,0 };
   int res = -1;
   int test_available_fd = -1;
   int gen_active = 0;
   int pid;
   char *argv[32];
   int argc = 1;
   char *buf, *command;
   FILE *child_commands = NULL;
   FILE *child_errors = NULL;
   FILE *child_events = NULL;
   struct ivr_localuser foo = {
      .playlist = AST_LIST_HEAD_INIT_VALUE,
      .finishlist = AST_LIST_HEAD_INIT_VALUE,
   };
   struct ivr_localuser *u = &foo;
   sigset_t fullset, oldset;

   lu = ast_module_user_add(chan);

   sigfillset(&fullset);
   pthread_sigmask(SIG_BLOCK, &fullset, &oldset);

   u->abort_current_sound = 0;
   u->chan = chan;
   
   if (ast_strlen_zero(args)) {
      ast_log(LOG_WARNING, "ExternalIVR requires a command to execute\n");
      ast_module_user_remove(lu);
      return -1;  
   }

   buf = ast_strdupa(data);

   argc = ast_app_separate_args(buf, '|', argv, sizeof(argv) / sizeof(argv[0]));

   if (pipe(child_stdin)) {
      ast_chan_log(LOG_WARNING, chan, "Could not create pipe for child input: %s\n", strerror(errno));
      goto exit;
   }

   if (pipe(child_stdout)) {
      ast_chan_log(LOG_WARNING, chan, "Could not create pipe for child output: %s\n", strerror(errno));
      goto exit;
   }

   if (pipe(child_stderr)) {
      ast_chan_log(LOG_WARNING, chan, "Could not create pipe for child errors: %s\n", strerror(errno));
      goto exit;
   }

   if (chan->_state != AST_STATE_UP) {
      ast_answer(chan);
   }

   if (ast_activate_generator(chan, &gen, u) < 0) {
      ast_chan_log(LOG_WARNING, chan, "Failed to activate generator\n");
      goto exit;
   } else
      gen_active = 1;

   pid = fork();
   if (pid < 0) {
      ast_log(LOG_WARNING, "Failed to fork(): %s\n", strerror(errno));
      goto exit;
   }

   if (!pid) {
      /* child process */
      int i;

      signal(SIGPIPE, SIG_DFL);
      pthread_sigmask(SIG_UNBLOCK, &fullset, NULL);

      if (ast_opt_high_priority)
         ast_set_priority(0);

      dup2(child_stdin[0], STDIN_FILENO);
      dup2(child_stdout[1], STDOUT_FILENO);
      dup2(child_stderr[1], STDERR_FILENO);
      for (i = STDERR_FILENO + 1; i < 1024; i++)
         close(i);
      execv(argv[0], argv);
      fprintf(stderr, "Failed to execute '%s': %s\n", argv[0], strerror(errno));
      _exit(1);
   } else {
      /* parent process */
      int child_events_fd = child_stdin[1];
      int child_commands_fd = child_stdout[0];
      int child_errors_fd = child_stderr[0];
      struct ast_frame *f;
      int ms;
      int exception;
      int ready_fd;
      int waitfds[2] = { child_errors_fd, child_commands_fd };
      struct ast_channel *rchan;

      pthread_sigmask(SIG_SETMASK, &oldset, NULL);

      close(child_stdin[0]);
      child_stdin[0] = 0;
      close(child_stdout[1]);
      child_stdout[1] = 0;
      close(child_stderr[1]);
      child_stderr[1] = 0;

      if (!(child_events = fdopen(child_events_fd, "w"))) {
         ast_chan_log(LOG_WARNING, chan, "Could not open stream for child events\n");
         goto exit;
      }

      if (!(child_commands = fdopen(child_commands_fd, "r"))) {
         ast_chan_log(LOG_WARNING, chan, "Could not open stream for child commands\n");
         goto exit;
      }

      if (!(child_errors = fdopen(child_errors_fd, "r"))) {
         ast_chan_log(LOG_WARNING, chan, "Could not open stream for child errors\n");
         goto exit;
      }

      test_available_fd = open("/dev/null", O_RDONLY);

      setvbuf(child_events, NULL, _IONBF, 0);
      setvbuf(child_commands, NULL, _IONBF, 0);
      setvbuf(child_errors, NULL, _IONBF, 0);

      res = 0;

      while (1) {
         if (ast_test_flag(chan, AST_FLAG_ZOMBIE)) {
            ast_chan_log(LOG_NOTICE, chan, "Is a zombie\n");
            res = -1;
            break;
         }

         if (ast_check_hangup(chan)) {
            ast_chan_log(LOG_NOTICE, chan, "Got check_hangup\n");
            send_child_event(child_events, 'H', NULL, chan);
            res = -1;
            break;
         }

         ready_fd = 0;
         ms = 100;
         errno = 0;
         exception = 0;

         rchan = ast_waitfor_nandfds(&chan, 1, waitfds, 2, &exception, &ready_fd, &ms);

         if (!AST_LIST_EMPTY(&u->finishlist)) {
            AST_LIST_LOCK(&u->finishlist);
            while ((entry = AST_LIST_REMOVE_HEAD(&u->finishlist, list))) {
               send_child_event(child_events, 'F', entry->filename, chan);
               free(entry);
            }
            AST_LIST_UNLOCK(&u->finishlist);
         }

         if (rchan) {
            /* the channel has something */
            f = ast_read(chan);
            if (!f) {
               ast_chan_log(LOG_NOTICE, chan, "Returned no frame\n");
               send_child_event(child_events, 'H', NULL, chan);
               res = -1;
               break;
            }

            if (f->frametype == AST_FRAME_DTMF) {
               send_child_event(child_events, f->subclass, NULL, chan);
               if (u->option_autoclear) {
                  if (!u->abort_current_sound && !u->playing_silence)
                     send_child_event(child_events, 'T', NULL, chan);
                  AST_LIST_LOCK(&u->playlist);
                  while ((entry = AST_LIST_REMOVE_HEAD(&u->playlist, list))) {
                     send_child_event(child_events, 'D', entry->filename, chan);
                     free(entry);
                  }
                  if (!u->playing_silence)
                     u->abort_current_sound = 1;
                  AST_LIST_UNLOCK(&u->playlist);
               }
            } else if ((f->frametype == AST_FRAME_CONTROL) && (f->subclass == AST_CONTROL_HANGUP)) {
               ast_chan_log(LOG_NOTICE, chan, "Got AST_CONTROL_HANGUP\n");
               send_child_event(child_events, 'H', NULL, chan);
               ast_frfree(f);
               res = -1;
               break;
            }
            ast_frfree(f);
         } else if (ready_fd == child_commands_fd) {
            char input[1024];

            if (exception || feof(child_commands)) {
               ast_chan_log(LOG_WARNING, chan, "Child process went away\n");
               res = -1;
               break;
            }

            if (!fgets(input, sizeof(input), child_commands))
               continue;

            command = ast_strip(input);

            ast_chan_log(LOG_DEBUG, chan, "got command '%s'\n", input);

            if (strlen(input) < 4)
               continue;

            if (input[0] == 'S') {
               if (ast_fileexists(&input[2], NULL, u->chan->language) == -1) {
                  ast_chan_log(LOG_WARNING, chan, "Unknown file requested '%s'\n", &input[2]);
                  send_child_event(child_events, 'Z', NULL, chan);
                  strcpy(&input[2], "exception");
               }
               if (!u->abort_current_sound && !u->playing_silence)
                  send_child_event(child_events, 'T', NULL, chan);
               AST_LIST_LOCK(&u->playlist);
               while ((entry = AST_LIST_REMOVE_HEAD(&u->playlist, list))) {
                  send_child_event(child_events, 'D', entry->filename, chan);
                  free(entry);
               }
               if (!u->playing_silence)
                  u->abort_current_sound = 1;
               entry = make_entry(&input[2]);
               if (entry)
                  AST_LIST_INSERT_TAIL(&u->playlist, entry, list);
               AST_LIST_UNLOCK(&u->playlist);
            } else if (input[0] == 'A') {
               if (ast_fileexists(&input[2], NULL, u->chan->language) == -1) {
                  ast_chan_log(LOG_WARNING, chan, "Unknown file requested '%s'\n", &input[2]);
                  send_child_event(child_events, 'Z', NULL, chan);
                  strcpy(&input[2], "exception");
               }
               entry = make_entry(&input[2]);
               if (entry) {
                  AST_LIST_LOCK(&u->playlist);
                  AST_LIST_INSERT_TAIL(&u->playlist, entry, list);
                  AST_LIST_UNLOCK(&u->playlist);
               }
            } else if (input[0] == 'H') {
               ast_chan_log(LOG_NOTICE, chan, "Hanging up: %s\n", &input[2]);
               send_child_event(child_events, 'H', NULL, chan);
               break;
            } else if (input[0] == 'O') {
               if (!strcasecmp(&input[2], "autoclear"))
                  u->option_autoclear = 1;
               else if (!strcasecmp(&input[2], "noautoclear"))
                  u->option_autoclear = 0;
               else
                  ast_chan_log(LOG_WARNING, chan, "Unknown option requested '%s'\n", &input[2]);
            }
         } else if (ready_fd == child_errors_fd) {
            char input[1024];

            if (exception || (dup2(child_commands_fd, test_available_fd) == -1) || feof(child_errors)) {
               ast_chan_log(LOG_WARNING, chan, "Child process went away\n");
               res = -1;
               break;
            }

            if (fgets(input, sizeof(input), child_errors)) {
               command = ast_strip(input);
               ast_chan_log(LOG_NOTICE, chan, "stderr: %s\n", command);
            }
         } else if ((ready_fd < 0) && ms) { 
            if (errno == 0 || errno == EINTR)
               continue;

            ast_chan_log(LOG_WARNING, chan, "Wait failed (%s)\n", strerror(errno));
            break;
         }
      }
   }

 exit:
   if (gen_active)
      ast_deactivate_generator(chan);

   if (child_events)
      fclose(child_events);

   if (child_commands)
      fclose(child_commands);

   if (child_errors)
      fclose(child_errors);

   if (test_available_fd > -1) {
      close(test_available_fd);
   }

   if (child_stdin[0])
      close(child_stdin[0]);

   if (child_stdin[1])
      close(child_stdin[1]);

   if (child_stdout[0])
      close(child_stdout[0]);

   if (child_stdout[1])
      close(child_stdout[1]);

   if (child_stderr[0])
      close(child_stderr[0]);

   if (child_stderr[1])
      close(child_stderr[1]);

   while ((entry = AST_LIST_REMOVE_HEAD(&u->playlist, list)))
      free(entry);

   ast_module_user_remove(lu);

   return res;
}

AST_MODULE_INFO_STANDARD	(	ASTERISK_GPL_KEY	,
		"External IVR Interface Application"
	)

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

Definition at line 110 of file app_externalivr.c.

References ast_calloc, and gen_state::u.

{
   struct ivr_localuser *u = params;
   struct gen_state *state;
   
   if (!(state = ast_calloc(1, sizeof(*state))))
      return NULL;

   state->u = u;

   return state;
}

static void gen_closestream

(

struct gen_state *

state

)

[static]

Definition at line 123 of file app_externalivr.c.

References ast_closestream(), ivr_localuser::chan, ast_channel::stream, gen_state::stream, and gen_state::u.

Referenced by gen_nextfile(), gen_readframe(), and gen_release().

{
   if (!state->stream)
      return;

   ast_closestream(state->stream);
   state->u->chan->stream = NULL;
   state->stream = NULL;
}

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

Definition at line 200 of file app_externalivr.c.

References ast_chan_log, ast_frfree, ast_write(), errno, f, gen_readframe(), LOG_WARNING, gen_state::sample_queue, and ast_frame::samples.

{
   struct gen_state *state = data;
   struct ast_frame *f = NULL;
   int res = 0;

   state->sample_queue += samples;

   while (state->sample_queue > 0) {
      if (!(f = gen_readframe(state)))
         return -1;

      res = ast_write(chan, f);
      ast_frfree(f);
      if (res < 0) {
         ast_chan_log(LOG_WARNING, chan, "Failed to write frame: %s\n", strerror(errno));
         return -1;
      }
      state->sample_queue -= f->samples;
   }

   return res;
}

static int gen_nextfile

(

struct gen_state *

state

)

[static]

Definition at line 142 of file app_externalivr.c.

References ast_chan_log, AST_LIST_REMOVE_HEAD, ast_openstream_full(), ivr_localuser::chan, gen_state::current, errno, gen_closestream(), LOG_WARNING, gen_state::stream, and gen_state::u.

Referenced by gen_readframe().

{
   struct ivr_localuser *u = state->u;
   char *file_to_stream;
   
   u->abort_current_sound = 0;
   u->playing_silence = 0;
   gen_closestream(state);

   while (!state->stream) {
      state->current = AST_LIST_REMOVE_HEAD(&u->playlist, list);
      if (state->current) {
         file_to_stream = state->current->filename;
      } else {
         file_to_stream = "silence/10";
         u->playing_silence = 1;
      }

      if (!(state->stream = ast_openstream_full(u->chan, file_to_stream, u->chan->language, 1))) {
         ast_chan_log(LOG_WARNING, u->chan, "File '%s' could not be opened: %s\n", file_to_stream, strerror(errno));
         if (!u->playing_silence) {
            continue;
         } else { 
            break;
         }
      }
   }

   return (!state->stream);
}

static struct ast_frame* gen_readframe

(

struct gen_state *

state

)

[static, read]

Definition at line 173 of file app_externalivr.c.

References AST_LIST_FIRST, AST_LIST_INSERT_TAIL, AST_LIST_LOCK, AST_LIST_UNLOCK, ast_readframe(), gen_state::current, f, gen_closestream(), gen_nextfile(), gen_state::stream, and gen_state::u.

Referenced by gen_generate().

{
   struct ast_frame *f = NULL;
   struct ivr_localuser *u = state->u;
   
   if (u->abort_current_sound ||
       (u->playing_silence && AST_LIST_FIRST(&u->playlist))) {
      gen_closestream(state);
      AST_LIST_LOCK(&u->playlist);
      gen_nextfile(state);
      AST_LIST_UNLOCK(&u->playlist);
   }

   if (!(state->stream && (f = ast_readframe(state->stream)))) {
      if (state->current) {
         AST_LIST_LOCK(&u->finishlist);
         AST_LIST_INSERT_TAIL(&u->finishlist, state->current, list);
         AST_LIST_UNLOCK(&u->finishlist);
         state->current = NULL;
      }
      if (!gen_nextfile(state))
         f = ast_readframe(state->stream);
   }

   return f;
}

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

Definition at line 133 of file app_externalivr.c.

References free, and gen_closestream().

{
   struct gen_state *state = data;

   gen_closestream(state);
   free(data);
}

static int load_module

(

void

)

[static]

Definition at line 580 of file app_externalivr.c.

References app_exec, and ast_register_application().

{
   return ast_register_application(app, app_exec, synopsis, descrip);
}

static struct playlist_entry* make_entry

(

const char *

filename

)

[static, read]

Definition at line 231 of file app_externalivr.c.

References ast_calloc.

Referenced by app_exec().

{
   struct playlist_entry *entry;
   
   if (!(entry = ast_calloc(1, sizeof(*entry) + strlen(filename) + 10))) /* XXX why 10 ? */
      return NULL;

   strcpy(entry->filename, filename);

   return entry;
}

static void send_child_event	(	FILE *	handle,
		const char	event,
		const char *	data,
		const struct ast_channel *	chan
	)			[static]

Definition at line 95 of file app_externalivr.c.

References ast_chan_log, and LOG_DEBUG.

Referenced by app_exec().

{
   char tmp[256];

   if (!data) {
      snprintf(tmp, sizeof(tmp), "%c,%10d", event, (int)time(NULL));
   } else {
      snprintf(tmp, sizeof(tmp), "%c,%10d,%s", event, (int)time(NULL), data);
   }

   fprintf(handle, "%s\n", tmp);
   ast_chan_log(LOG_DEBUG, chan, "sent '%s'\n", tmp);
}

static int unload_module

(

void

)

[static]

Definition at line 569 of file app_externalivr.c.

References ast_module_user_hangup_all, and ast_unregister_application().

{
   int res;

   res = ast_unregister_application(app);

   ast_module_user_hangup_all();

   return res;
}

---

Variable Documentation

const char* app = "ExternalIVR" [static]

Definition at line 56 of file app_externalivr.c.

const char* descrip [static]

Definition at line 60 of file app_externalivr.c.

struct ast_generator gen [static]

Definition at line 224 of file app_externalivr.c.

Referenced by app_exec(), reload_config(), and set_config().

const char* synopsis = "Interfaces with an external IVR application" [static]

Definition at line 58 of file app_externalivr.c.