inear/dvb-tools/lib/libdvben50221/en50221_app_ai.c

/*
    en50221 encoder An implementation for libdvb
    an implementation for the en50221 transport layer

    Copyright (C) 2004, 2005 Manu Abraham <abraham.manu@gmail.com>
    Copyright (C) 2005 Julian Scheel (julian at jusst dot de)
    Copyright (C) 2006 Andrew de Quincey (adq_dvb@lidskialf.net)

    This library is free software; you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as
    published by the Free Software Foundation; either version 2.1 of
    the License, or (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
*/

#include <string.h>
#include <libdvbmisc/dvbmisc.h>
#include <pthread.h>
#include "en50221_app_ai.h"
#include "en50221_app_tags.h"
#include "asn_1.h"

struct en50221_app_ai {
	struct en50221_app_send_functions *funcs;

	en50221_app_ai_callback callback;
	void *callback_arg;

	pthread_mutex_t lock;
};

static int en50221_app_ai_parse_app_info(struct en50221_app_ai *ai,
					 uint8_t slot_id,
					 uint16_t session_number,
					 uint8_t * data,
					 uint32_t data_length);


struct en50221_app_ai *en50221_app_ai_create(struct en50221_app_send_functions *funcs)
{
	struct en50221_app_ai *ai = NULL;

	// create structure and set it up
	ai = malloc(sizeof(struct en50221_app_ai));
	if (ai == NULL) {
		return NULL;
	}
	ai->funcs = funcs;
	ai->callback = NULL;

	pthread_mutex_init(&ai->lock, NULL);

	// done
	return ai;
}

void en50221_app_ai_destroy(struct en50221_app_ai *ai)
{
	pthread_mutex_destroy(&ai->lock);
	free(ai);
}

void en50221_app_ai_register_callback(struct en50221_app_ai *ai,
				      en50221_app_ai_callback callback,
				      void *arg)
{
	pthread_mutex_lock(&ai->lock);
	ai->callback = callback;
	ai->callback_arg = arg;
	pthread_mutex_unlock(&ai->lock);
}

int en50221_app_ai_enquiry(struct en50221_app_ai *ai,
			   uint16_t session_number)
{
	uint8_t data[4];

	data[0] = (TAG_APP_INFO_ENQUIRY >> 16) & 0xFF;
	data[1] = (TAG_APP_INFO_ENQUIRY >> 8) & 0xFF;
	data[2] = TAG_APP_INFO_ENQUIRY & 0xFF;
	data[3] = 0;

	return ai->funcs->send_data(ai->funcs->arg, session_number, data, 4);
}

int en50221_app_ai_entermenu(struct en50221_app_ai *ai,
			     uint16_t session_number)
{
	uint8_t data[4];

	data[0] = (TAG_ENTER_MENU >> 16) & 0xFF;
	data[1] = (TAG_ENTER_MENU >> 8) & 0xFF;
	data[2] = TAG_ENTER_MENU & 0xFF;
	data[3] = 0;

	return ai->funcs->send_data(ai->funcs->arg, session_number, data, 4);
}

int en50221_app_ai_message(struct en50221_app_ai *ai,
			   uint8_t slot_id,
			   uint16_t session_number,
			   uint32_t resource_id,
			   uint8_t * data, uint32_t data_length)
{
	(void) resource_id;

	// get the tag
	if (data_length < 3) {
		print(LOG_LEVEL, ERROR, 1, "Received short data\n");
		return -1;
	}
	uint32_t tag = (data[0] << 16) | (data[1] << 8) | data[2];

	switch (tag) {
	case TAG_APP_INFO:
		return en50221_app_ai_parse_app_info(ai, slot_id,
						     session_number,
						     data + 3,
						     data_length - 3);
	}

	print(LOG_LEVEL, ERROR, 1, "Received unexpected tag %x\n", tag);
	return -1;
}







static int en50221_app_ai_parse_app_info(struct en50221_app_ai *ai,
					 uint8_t slot_id,
					 uint16_t session_number,
					 uint8_t * data,
					 uint32_t data_length)
{
	// parse the length field
	int length_field_len;
	uint16_t asn_data_length;
	if ((length_field_len = asn_1_decode(&asn_data_length, data, data_length)) < 0) {
		print(LOG_LEVEL, ERROR, 1,
		      "Received data with invalid length from module on slot %02x\n",
		      slot_id);
		return -1;
	}
	// check it
	if (asn_data_length < 6) {
		print(LOG_LEVEL, ERROR, 1, "Received short data\n");
		return -1;
	}
	if (asn_data_length > (data_length - length_field_len)) {
		print(LOG_LEVEL, ERROR, 1, "Received short data\n");
		return -1;
	}
	uint8_t *app_info = data + length_field_len;

	// parse the fields
	uint8_t application_type = app_info[0];
	uint16_t application_manufacturer = (app_info[1] << 8) | app_info[2];
	uint16_t manufacturer_code = (app_info[3] << 8) | app_info[4];
	uint8_t menu_string_length = app_info[5];
	uint8_t *menu_string = app_info + 6;

	// check the menu_string_length
	if (menu_string_length > (asn_data_length - 6)) {
		print(LOG_LEVEL, ERROR, 1,
		      "Received bad menu string length - adjusting\n");
		menu_string_length = asn_data_length - 6;
	}
	// tell the app
	pthread_mutex_lock(&ai->lock);
	en50221_app_ai_callback cb = ai->callback;
	void *cb_arg = ai->callback_arg;
	pthread_mutex_unlock(&ai->lock);
	if (cb) {
		return cb(cb_arg, slot_id, session_number,
			  application_type, application_manufacturer,
			  manufacturer_code, menu_string_length,
			  menu_string);
	}
	return 0;
}