ml_com.c

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/*------------------------------------------------------------------------
 *---------------------           RT-WMP              --------------------
 *------------------------------------------------------------------------
 *                                                         V7.0B  11/05/10
 *
 *
 *  File: ./src/core/ml_com.c
 *  Authors: Danilo Tardioli
 *  ----------------------------------------------------------------------
 *  Copyright (C) 2000-2010, Universidad de Zaragoza, SPAIN
 *
 *  Contact Addresses: Danilo Tardioli                   dantard@unizar.es
 *
 *  RT-WMP is free software; you can  redistribute it and/or  modify it
 *  under the terms of the GNU General Public License  as published by the
 *  Free Software Foundation;  either  version 2, or (at  your option) any
 *  later version.
 *
 *  RT-WMP  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
 *  General Public License for more details.
 *
 *  You should have received  a  copy of  the  GNU General Public  License
 *  distributed with RT-WMP;  see file COPYING.   If not,  write to the
 *  Free Software  Foundation,  59 Temple Place  -  Suite 330,  Boston, MA
 *  02111-1307, USA.
 *
 *  As a  special exception, if you  link this  unit  with other  files to
 *  produce an   executable,   this unit  does  not  by  itself cause  the
 *  resulting executable to be covered by the  GNU General Public License.
 *  This exception does  not however invalidate  any other reasons why the
 *  executable file might be covered by the GNU Public License.
 *
 *----------------------------------------------------------------------*/

#include "config/compiler.h"

#include "core/include/frames.h"
#include "core/include/definitions.h"
#include "core/interface/wmp_interface.h"
#include "core/include/wmp_misc.h"
#include "core/include/ml_com.h"
#include "core/include/ll_com.h"
#include "core/include/frame_compress.h"
#include "core/include/wmp_utils.h"
#include "core/include/global.h"

static int wack = 0;
static int filter_type = 0, filter_param = 0;

void closeMiddleLevelCom() {
        closeLowLevelCom();
}

int initMiddleLevelCom() {
        return initLowLevelCom();
}
void ml_set_ett(int _use_ett, int _ett_mult, int _ett_max) {
        status.use_ett = _use_ett;
}

int ml_calculate_duration(int rate, int size) {
        return 1;
}

/* FILTER */
void ml_set_filter(char * ftype, int param){
        filter_param = param;
        if (strcmp(ftype,"chain") == 0){
                filter_type = 1;
        }else if (strcmp(ftype,"star") == 0){
                filter_type = 2;
        }
}

void wmpForceTopology(char * name, int param){
        ml_set_filter(name, param);
}

static int ml_filter(char from){
        switch (filter_type){
        case 1:{ /* chain */
                if (abs(from-wmpGetNodeId())>1){
                        return 1;
                }else{
                        return 0;
                }
        }
        case 2:{ /* star */
                if (wmpGetNodeId()==filter_param){
                        return 0;
                }else{
                        if (from == filter_param){
                                return 0;
                        }
                }
                return 1;
        }
        default:
                return 0;
        }
}


/* RX_ERROR */
static int rx_error_type = 0, last_discarded = 0, rx_error_param = 1,last_discarded_type = 0;
void ml_set_rx_error(char * ftype, int param){
        rx_error_param = param;
        if (strcmp(ftype,"all") == 0){
                rx_error_type = 1;
        }else if (strcmp(ftype,"messages") == 0){
                rx_error_type = 2;
        }else if (strcmp(ftype,"unconfirm") == 0){
                rx_error_type = 3;
        }
}

void wmpSetRxError(char * name, int rate){
        if (rate == 0){
                rx_error_param = 1;
        }
        ml_set_rx_error(name, rate);
}

static int ml_rx_error(wmpFrame * p){
        int discard = 0;
        if (rx_error_type == 0 || rx_error_param == 0){
                return 0;
        }

//      if (p->hdr.to != wmpGetNodeId()){
//              return 0;
//      }

//      if (p->hdr.serial == last_discarded && p->hdr.type == last_discarded_type){
//              return 1;
//      }
        switch (rx_error_type){
        case 1:
                discard = ((rand() % rx_error_param) == 0);
                break;
        case 2:
                if (p->hdr.type == MESSAGE){
                        discard = ((rand() % rx_error_param) == 0);
                }
                break;
        case 3:
                discard = 0;
                if ((rand() % rx_error_param) == 0){
                        mBitsUnset(p->hdr.ack,rand() % wmpGetNumOfNodes());
                }
                break;
        }


        if (discard){
                last_discarded = p->hdr.serial;
                last_discarded_type = p->hdr.type;
        }
        return discard;
}

/* TX and RX functions */

int ml_send(wmpFrame * p, int size) {
        int ret = UNDEF;

        if (p->hdr.type != DROP_TOKEN && p->hdr.type != ACK) {
                /* every time I send something, I wait an ack */
                wack = 1;
        }
        p->hdr.net_id = status.net_id;

        ret = cmp_send((char *) p, size);

        return ret;
}

int ml_receive(wmpFrame *f, int timeout) {
        rxInfo ret;
        struct timespec before, after;
        unsigned long long elapsed_ms = 0, tot_elapsed = 0; //, orig_timeout=timeout;

        while (timeout > 0) {
                /* wait TIMEOUT for acknoledwge frame or for net inactivity */
                GETNSTIMEOFDAY(&before);
                ret = cmp_receive((char*) f, timeout);
                GETNSTIMEOFDAY(&after);

                elapsed_ms = wmp_elapsed_ms(&before, &after);
                tot_elapsed+= elapsed_ms;
                
                if (ret.error) {
                        return EXPIRED;
                }

                timeout = (timeout - elapsed_ms) > 0 ? (timeout - elapsed_ms) : 0;

                if (ret.proto == 0x6969 || ret.proto == 0x6970) {

                        if (f->hdr.from == status.id) {
                                /* discard sent frame if present*/
                                continue;
                        }

                        if (ml_filter(f->hdr.from)){
                                //continue;
                        }

                        if (ml_rx_error(f)){
                                continue;
                        }

                        if (f->hdr.net_id == status.net_id) {
                                if (ret.has_lq) {
                                        f->hdr.rssi = ret.rssi;
                                        f->hdr.noise = ret.noise;
                                }
                                return RECEIVE_OK;
                        } else {
                                WMP_MSG(stderr, "*** Warning ::: Foreign network detected (id:%d)\n", f->hdr.net_id);
                                continue;
                        }
                } else{
//                      if (timeout < 5){
//                              timeout+=2;
//                      }
//                      WMP_MSG(stderr, "*** Warning ::: Foreign frame detected (proto:%d) restart read with TO %d (elapsed:%d)\n", ret.proto, timeout, elapsed_ms);
                        continue;
                }
        }

        return EXPIRED;
}