func_frame_drop.c File Reference

Function that drops specified frames from channels. More...

#include "asterisk.h"
#include "asterisk/module.h"
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/framehook.h"

Include dependency graph for func_frame_drop.c:

Go to the source code of this file.

Data Structures
struct	frame_drop_data

Enumerations
enum	direction { TX = 0, RX }

Functions
	AST_MODULE_INFO_STANDARD_EXTENDED (ASTERISK_GPL_KEY, "Function to drop frames on a channel.")
static void	datastore_destroy_cb (void *data)
static int	frame_drop_helper (struct ast_channel *chan, const char *cmd, char *data, const char *value)
static void	hook_destroy_cb (void *framedata)
static struct ast_frame *	hook_event_cb (struct ast_channel *chan, struct ast_frame *frame, enum ast_framehook_event event, void *data)
static int	load_module (void)
static int	unload_module (void)

Variables
struct {
const char *   str
int   type
}	controlframetype2str []
static const struct ast_datastore_info	frame_drop_datastore
static struct ast_custom_function	frame_drop_function
struct {
const char *   str
enum ast_frame_type   type
}	frametype2str []

Detailed Description

Function that drops specified frames from channels.

Author

Naveen Albert aster.nosp@m.isk@.nosp@m.phrea.nosp@m.knet.nosp@m..org

Definition in file func_frame_drop.c.

Enumeration Type Documentation

direction

enum direction

Enumerator
TX
RX

Definition at line 137 of file func_frame_drop.c.

               {
    TX = 0,
    RX,
};

Function Documentation

AST_MODULE_INFO_STANDARD_EXTENDED()

AST_MODULE_INFO_STANDARD_EXTENDED	(	ASTERISK_GPL_KEY	,
		"Function to drop frames on a channel."
	)

Referenced by load_module().

datastore_destroy_cb()

static void datastore_destroy_cb ( void *  data )

static

Definition at line 148 of file func_frame_drop.c.

References ast_free.

                                             {
   ast_free(data);
}

frame_drop_helper()

static int frame_drop_helper ( struct ast_channel *  chan, const char *  cmd, char *  data, const char *  value  )

static

Definition at line 203 of file func_frame_drop.c.

References ARRAY_LEN, ast_calloc, ast_channel_datastore_add(), ast_channel_datastore_find(), ast_channel_datastore_remove(), ast_channel_lock, ast_channel_unlock, ast_datastore_alloc, ast_datastore_free(), ast_framehook_attach(), ast_framehook_detach(), AST_FRAMEHOOK_INTERFACE_VERSION, ast_free, ast_malloc, controlframetype2str, frame_drop_data::controlvalues, ast_datastore::data, ast_framehook_interface::data, frametype2str, hook_destroy_cb(), hook_event_cb(), id, frame_drop_data::list_type, NULL, RX, str, strcasestr(), TX, frame_drop_data::values, and ast_framehook_interface::version.

{
   char *buffer;
   struct frame_drop_data *framedata;
   struct ast_datastore *datastore = NULL;
   struct ast_framehook_interface interface = {
      .version = AST_FRAMEHOOK_INTERFACE_VERSION,
      .event_cb = hook_event_cb,
      .destroy_cb = hook_destroy_cb,
   };
   int i = 0;

   if (!(framedata = ast_calloc(1, sizeof(*framedata)))) {
      return 0;
   }

   interface.data = framedata;

   if (!strcasecmp(data, "RX")) {
      framedata->list_type = RX;
   } else {
      framedata->list_type = TX;
   }

   buffer = ast_malloc(sizeof(value) + 3); /* leading and trailing comma and null terminator */
   snprintf(buffer, sizeof(value) + 2, ",%s,", value);
   for (i = 0; i < ARRAY_LEN(frametype2str); i++) {
      if (strcasestr(value, frametype2str[i].str)) {
         framedata->values[i] = 1;
      }
   }

   for (i = 0; i < ARRAY_LEN(controlframetype2str); i++) {
      if (strcasestr(value, controlframetype2str[i].str)) {
         framedata->controlvalues[i] = 1;
      }
   }
   ast_free(buffer);

   ast_channel_lock(chan);
   i = ast_framehook_attach(chan, &interface);
   if (i >= 0) {
      int *id;
      if ((datastore = ast_channel_datastore_find(chan, &frame_drop_datastore, NULL))) {
         id = datastore->data;
         ast_framehook_detach(chan, *id);
         ast_channel_datastore_remove(chan, datastore);
         ast_datastore_free(datastore);
      }

      if (!(datastore = ast_datastore_alloc(&frame_drop_datastore, NULL))) {
         ast_framehook_detach(chan, i);
         ast_channel_unlock(chan);
         return 0;
      }

      if (!(id = ast_calloc(1, sizeof(int)))) {
         ast_datastore_free(datastore);
         ast_framehook_detach(chan, i);
         ast_channel_unlock(chan);
         return 0;
      }

      *id = i; /* Store off the id. The channel is still locked so it is safe to access this ptr. */
      datastore->data = id;
      ast_channel_datastore_add(chan, datastore);
   }
   ast_channel_unlock(chan);

   return 0;
}

hook_destroy_cb()

static void hook_destroy_cb ( void *  framedata )

static

Definition at line 157 of file func_frame_drop.c.

References ast_free.

Referenced by frame_drop_helper().

{
   ast_free(framedata);
}

hook_event_cb()

static struct ast_frame* hook_event_cb ( struct ast_channel *  chan, struct ast_frame *  frame, enum ast_framehook_event  event, void *  data  )

static

Definition at line 162 of file func_frame_drop.c.

References ARRAY_LEN, AST_FRAME_CONTROL, AST_FRAMEHOOK_EVENT_READ, AST_FRAMEHOOK_EVENT_WRITE, ast_frfree, ast_null_frame, controlframetype2str, frame_drop_data::controlvalues, ast_frame::frametype, frametype2str, ast_frame_subclass::integer, frame_drop_data::list_type, RX, ast_frame::subclass, TX, and frame_drop_data::values.

Referenced by frame_drop_helper().

{
   int i;
   int drop_frame = 0;
   struct frame_drop_data *framedata = data;
   if (!frame) {
      return frame;
   }

   if (!((event == AST_FRAMEHOOK_EVENT_WRITE && framedata->list_type == TX) ||
      (event == AST_FRAMEHOOK_EVENT_READ && framedata->list_type == RX))) {
      return frame;
   }

   if (frame->frametype == AST_FRAME_CONTROL) {
      for (i = 0; i < ARRAY_LEN(controlframetype2str); i++) {
         if (frame->subclass.integer == controlframetype2str[i].type) {
            if (framedata->controlvalues[i]) {
               drop_frame = 1;
            }
            break;
         }
      }
   } else {
      for (i = 0; i < ARRAY_LEN(frametype2str); i++) {
         if (frame->frametype == frametype2str[i].type) {
            if (framedata->values[i]) {
               drop_frame = 1;
            }
            break;
         }
      }
   }

   if (drop_frame) {
      ast_frfree(frame);
      frame = &ast_null_frame;
   }
   return frame;
}

load_module()

static int load_module ( void  )

static

Definition at line 285 of file func_frame_drop.c.

References ast_custom_function_register, AST_MODULE_INFO_STANDARD_EXTENDED(), AST_MODULE_LOAD_DECLINE, AST_MODULE_LOAD_SUCCESS, and ASTERISK_GPL_KEY.

{
   int res = ast_custom_function_register(&frame_drop_function);
   return res ? AST_MODULE_LOAD_DECLINE : AST_MODULE_LOAD_SUCCESS;
}

unload_module()

static int unload_module ( void  )

static

Definition at line 280 of file func_frame_drop.c.

References ast_custom_function_unregister().

{
   return ast_custom_function_unregister(&frame_drop_function);
}

Variable Documentation

controlframetype2str

struct { ... } controlframetype2str[]

Referenced by frame_drop_helper(), and hook_event_cb().

frame_drop_datastore

const struct ast_datastore_info frame_drop_datastore

static

Initial value:

= {
   .type = "framedrop",
   .destroy = datastore_destroy_cb
}

Definition at line 152 of file func_frame_drop.c.

frame_drop_function

struct ast_custom_function frame_drop_function

static

Initial value:

= {
   .name = "FRAME_DROP",
   .write = frame_drop_helper,
}

Definition at line 275 of file func_frame_drop.c.

frametype2str

struct { ... } frametype2str[]

Referenced by frame_drop_helper(), and hook_event_cb().

str

const char* str

Definition at line 98 of file func_frame_drop.c.

Referenced by frame_drop_helper().

type

int type

Definition at line 97 of file func_frame_drop.c.