PeerStreamer

/*

 *          Policy Management

 *

 *          NEC Europe Ltd. PROPRIETARY INFORMATION

 *

 * This software is supplied under the terms of a license agreement

 * or nondisclosure agreement with NEC Europe Ltd. and may not be

 * copied or disclosed except in accordance with the terms of that

 * agreement.

 *

 *      Copyright (c) 2009 NEC Europe Ltd. All Rights Reserved.

 *

 * Authors: Kristian Beckers  <beckers@nw.neclab.eu>

 *          Sebastian Kiesel  <kiesel@nw.neclab.eu>

 *          

 *

 * NEC Europe Ltd. DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED,

 * INCLUDING BUT NOT LIMITED TO IMPLIED WARRANTIES OF MERCHANTABILITY

 * AND FITNESS FOR A PARTICULAR PURPOSE AND THE WARRANTY AGAINST LATENT

 * DEFECTS, WITH RESPECT TO THE PROGRAM AND THE ACCOMPANYING

 * DOCUMENTATION.

 *

 * No Liability For Consequential Damages IN NO EVENT SHALL NEC Europe

 * Ltd., NEC Corporation OR ANY OF ITS SUBSIDIARIES BE LIABLE FOR ANY

 * DAMAGES WHATSOEVER (INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOSS

 * OF BUSINESS PROFITS, BUSINESS INTERRUPTION, LOSS OF INFORMATION, OR

 * OTHER PECUNIARY LOSS AND INDIRECT, CONSEQUENTIAL, INCIDENTAL,

 * ECONOMIC OR PUNITIVE DAMAGES) ARISING OUT OF THE USE OF OR INABILITY

 * TO USE THIS PROGRAM, EVEN IF NEC Europe Ltd. HAS BEEN ADVISED OF THE

 * POSSIBILITY OF SUCH DAMAGES.

 *

 *     THIS HEADER MAY NOT BE EXTRACTED OR MODIFIED IN ANY WAY.

 */

#include <ml_all.h>

/**************************** START OF INTERNALS ***********************/

/*

 * reserved message type for internal puposes

 */

#define MSG_TYPE_ML_KEEPALIVE 0x126        //TODO: check that it is really interpreted as internal

/*

 * a pointer to a libevent instance

 */

struct event_base *base;

/*

 * define the nr of connections the messaging layer can handle

 */

#define CONNECTBUFSIZE 10000

/*

 * define the nr of data that can be received parallel

 */

#define RECVDATABUFSIZE 10000

/*

 * define an array for message multiplexing

 */

#define MSGMULTIPLEXSIZE 127

/*

 * timeout before thinking that the STUN server can't be connected

 */

#define NAT_TRAVERSAL_TIMEOUT { 1, 0 }

/*

 * timeout before thinking of an mtu problem (check MAX_TRIALS as well)

 */

#define PMTU_TIMEOUT 1000000 // in usec

/*

 * retry sending connection messages this many times before reducing pmtu

 */

#define MAX_TRIALS 3

/*

 * default timeout value between the first and the last received packet of a message

 */

#define RECV_TIMEOUT_DEFAULT { 2, 0 }

#ifdef RTX

/*

 * default timeout value for a packet reception

 */

#define PKT_RECV_TIMEOUT_DEFAULT { 0, 50000 } // 50 ms

/*

 * default timeout value for a packet reception

 */

#define LAST_PKT_RECV_TIMEOUT_DEFAULT { 1, 700000 }

/*

 * default fraction of RECV_TIMEOUT_DEFAULT for a last packet(s) reception timeout

 */

#define LAST_PKT_RECV_TIMEOUT_FRACTION 0.7

#endif

/*

 * global variables

 */

/*

 * define a buffer of pointers to connect structures

 */

connect_data *connectbuf[CONNECTBUFSIZE];

/*

 * define a pointer buffer with pointers to recv_data structures

 */

recvdata *recvdatabuf[RECVDATABUFSIZE];

/*

 * define a pointer buffer for message multiplexing

 */

receive_data_cb recvcbbuf[MSGMULTIPLEXSIZE];

/*

 * stun server address

 */

struct sockaddr_in stun_server;

/*

 * receive timeout

 */

static struct timeval recv_timeout = RECV_TIMEOUT_DEFAULT;

/*

 * boolean NAT traversal successful if true

 */

boolean NAT_traversal;

/*

 * file descriptor for local socket

 */

evutil_socket_t socketfd;

/*

 * local socketID

 */

socket_ID local_socketID;

socketID_handle loc_socketID = &local_socketID;

/*

 * callback function pointers

 */

/*

 * monitoring module callbacks

 */

get_recv_pkt_inf_cb get_Recv_pkt_inf_cb = NULL;

get_send_pkt_inf_cb get_Send_pkt_inf_cb = NULL;

set_monitoring_header_pkt_cb set_Monitoring_header_pkt_cb = NULL;

get_recv_data_inf_cb get_Recv_data_inf_cb = NULL;

get_send_data_inf_cb get_Send_data_inf_cb = NULL;

set_monitoring_header_data_cb set_Monitoring_header_data_cb = NULL;

/*

 * connection callbacks

 */

receive_connection_cb receive_Connection_cb = NULL;

connection_failed_cb failed_Connection_cb = NULL;

/*

 * local socketID callback

 */

receive_localsocketID_cb receive_SocketID_cb;

/*

 * boolean that defines if received data is transmitted to the upper layer

 * via callback or via upper layer polling

 */

boolean recv_data_callback;

/*

 * helper function to get rid of a warning

 */

#ifndef _WIN32

int min(int a, int b) {

        if (a > b) return b;

        return a;

}

#endif

#ifdef RTX

//*********Counters**********

struct Counters {

        unsigned int receivedCompleteMsgCounter;

        unsigned int receivedIncompleteMsgCounter;

        unsigned int receivedDataPktCounter;

        unsigned int receivedRTXDataPktCounter;

        unsigned int receivedNACK1PktCounter;

        unsigned int receivedNACKMorePktCounter;

        unsigned int sentDataPktCounter;

        unsigned int sentRTXDataPktCtr;

        unsigned int sentNACK1PktCounter;

        unsigned int sentNACKMorePktCounter;

} counters;

extern unsigned int sentRTXDataPktCounter;

/*

 * receive timeout for a packet

 */

static struct timeval pkt_recv_timeout = PKT_RECV_TIMEOUT_DEFAULT;

static struct timeval last_pkt_recv_timeout = LAST_PKT_RECV_TIMEOUT_DEFAULT;

void mlShowCounters() {

        counters.sentRTXDataPktCtr = sentRTXDataPktCounter;

        fprintf(stderr, "\nreceivedCompleteMsgCounter: %d\nreceivedIncompleteMsgCounter: %d\nreceivedDataPktCounter: %d\nreceivedRTXDataPktCounter: %d\nreceivedNACK1PktCounter: %d\nreceivedNACKMorePktCounter: %d\nsentDataPktCounter: %d\nsentRTXDataPktCtr: %d\nsentNACK1PktCounter: %d\nsentNACKMorePktCounter: %d\n", counters.receivedCompleteMsgCounter, counters.receivedIncompleteMsgCounter, counters.receivedDataPktCounter, counters.receivedRTXDataPktCounter, counters.receivedNACK1PktCounter, counters.receivedNACKMorePktCounter, counters.sentDataPktCounter, counters.sentRTXDataPktCtr, counters.sentNACK1PktCounter, counters.sentNACKMorePktCounter);

        return;

}

void recv_nack_msg(struct msg_header *msg_h, char *msgbuf, int msg_size)

{

        struct nack_msg *nackmsg;

        msgbuf += msg_h->len_mon_data_hdr;

        msg_size -= msg_h->len_mon_data_hdr;

        nackmsg = (struct nack_msg*) msgbuf;

        unsigned int gapSize = nackmsg->offsetTo - nackmsg->offsetFrom;

        //if (gapSize == 1349) counters.receivedNACK1PktCounter++;

        //else counters.receivedNACKMorePktCounter++;

        rtxPacketsFromTo(nackmsg->con_id, nackmsg->msg_seq_num, nackmsg->offsetFrom, nackmsg->offsetTo);        

}

void send_msg(int con_id, int msg_type, void* msg, int msg_len, bool truncable, send_params * sParams);

void pkt_recv_timeout_cb(int fd, short event, void *arg){

        int recv_id = (long) arg;

        debug("ML: recv_timeout_cb called. Timeout for id:%d\n",recv_id);

        //check if message still exists        

        if (recvdatabuf[recv_id] == NULL) return;

        //check if gap was filled in the meantime

        if (recvdatabuf[recv_id]->gapArray[recvdatabuf[recv_id]->firstGap].offsetFrom == recvdatabuf[recv_id]->gapArray[recvdatabuf[recv_id]->firstGap].offsetTo) {

                recvdatabuf[recv_id]->firstGap++;

                return;        

        }

        struct nack_msg nackmsg;

        nackmsg.con_id = recvdatabuf[recv_id]->txConnectionID;

        nackmsg.msg_seq_num = recvdatabuf[recv_id]->seqnr;

        nackmsg.offsetFrom = recvdatabuf[recv_id]->gapArray[recvdatabuf[recv_id]->firstGap].offsetFrom;

        nackmsg.offsetTo = recvdatabuf[recv_id]->gapArray[recvdatabuf[recv_id]->firstGap].offsetTo;

        recvdatabuf[recv_id]->firstGap++;

        unsigned int gapSize = nackmsg.offsetTo - nackmsg.offsetFrom;

        send_msg(recvdatabuf[recv_id]->connectionID, ML_NACK_MSG, (char *) &nackmsg, sizeof(struct nack_msg), true, &(connectbuf[recvdatabuf[recv_id]->connectionID]->defaultSendParams));        

}

void last_pkt_recv_timeout_cb(int fd, short event, void *arg){

        int recv_id = (long) arg;

        debug("ML: recv_timeout_cb called. Timeout for id:%d\n",recv_id);

        if (recvdatabuf[recv_id] == NULL) {

                return;

        }

        if (recvdatabuf[recv_id]->expectedOffset == recvdatabuf[recv_id]->bufsize - recvdatabuf[recv_id]->monitoringDataHeaderLen) return;

        struct nack_msg nackmsg;

        nackmsg.con_id = recvdatabuf[recv_id]->txConnectionID;

        nackmsg.msg_seq_num = recvdatabuf[recv_id]->seqnr;

        nackmsg.offsetFrom = recvdatabuf[recv_id]->expectedOffset;

        nackmsg.offsetTo = recvdatabuf[recv_id]->bufsize - recvdatabuf[recv_id]->monitoringDataHeaderLen;

        unsigned int gapSize = nackmsg.offsetTo - nackmsg.offsetFrom;

        send_msg(recvdatabuf[recv_id]->connectionID, ML_NACK_MSG, &nackmsg, sizeof(struct nack_msg), true, &(connectbuf[recvdatabuf[recv_id]->connectionID]->defaultSendParams));        

}

#endif

/*

 * convert a socketID to a string. It uses a static buffer, so either strdup is needed, or the string will get lost!

 */

const char *conid_to_string(int con_id)

{

        static char s[INET_ADDRSTRLEN+1+5+1+INET_ADDRSTRLEN+1+5+1];

        mlSocketIDToString(&connectbuf[con_id]->external_socketID, s, sizeof(s));

        return s;

}

void register_recv_localsocketID_cb(receive_localsocketID_cb local_socketID_cb)

{

        if (local_socketID_cb == NULL) {

                error("ML : Register receive_localsocketID_cb: NULL ptr \n");

        } else {

                receive_SocketID_cb = local_socketID_cb;

        }

}

//void keep_connection_alive(const int connectionID)

//{

//

//    // to be done with the NAT traversal

//    // send a message over the wire

//    printf("\n");

//

//}

void unsetStunServer()

{

        stun_server.sin_addr.s_addr = INADDR_NONE;

}

bool isStunDefined()

{

        return stun_server.sin_addr.s_addr != INADDR_NONE;

}

void send_msg(int con_id, int msg_type, void* msg, int msg_len, bool truncable, send_params * sParams) {

        socketaddrgen udpgen;

        bool retry;

        int pkt_len, offset;

        struct iovec iov[4];

        char h_pkt[MON_PKT_HEADER_SPACE];

        char h_data[MON_DATA_HEADER_SPACE];

        struct msg_header msg_h;

        debug("ML: send_msg to %s conID:%d extID:%d\n", conid_to_string(con_id), con_id, connectbuf[con_id]->external_connectionID);

        iov[0].iov_base = &msg_h;

        iov[0].iov_len = MSG_HEADER_SIZE;

        msg_h.local_con_id = htonl(con_id);

        msg_h.remote_con_id = htonl(connectbuf[con_id]->external_connectionID);

        msg_h.msg_type = msg_type;

        msg_h.msg_seq_num = htonl(connectbuf[con_id]->seqnr++);

        iov[1].iov_len = iov[2].iov_len = 0;

        iov[1].iov_base = h_pkt;

        iov[2].iov_base = h_data;

        if (connectbuf[con_id]->internal_connect)

                udpgen = connectbuf[con_id]->external_socketID.internal_addr;

        else

                udpgen = connectbuf[con_id]->external_socketID.external_addr;

        do{

                offset = 0;

                retry = false;

                // Monitoring layer hook

                if(set_Monitoring_header_data_cb != NULL) {

                        iov[2].iov_len = ((set_Monitoring_header_data_cb) (&(connectbuf[con_id]->external_socketID), msg_type));

                }

                msg_h.len_mon_data_hdr = iov[2].iov_len;

                if(get_Send_data_inf_cb != NULL && iov[2].iov_len != 0) {

                        mon_data_inf sd_data_inf;

                        memset(h_data, 0, MON_DATA_HEADER_SPACE);

                        sd_data_inf.remote_socketID = &(connectbuf[con_id]->external_socketID);

                        sd_data_inf.buffer = msg;

                        sd_data_inf.bufSize = msg_len;

                        sd_data_inf.msgtype = msg_type;

                        sd_data_inf.monitoringDataHeader = iov[2].iov_base;

                        sd_data_inf.monitoringDataHeaderLen = iov[2].iov_len;

                        sd_data_inf.priority = sParams->priority;

                        sd_data_inf.padding = sParams->padding;

                        sd_data_inf.confirmation = sParams->confirmation;

                        sd_data_inf.reliable = sParams->reliable;

                        memset(&sd_data_inf.arrival_time, 0, sizeof(struct timeval));

                        (get_Send_data_inf_cb) ((void *) &sd_data_inf);

                }

                do {

                        if(set_Monitoring_header_pkt_cb != NULL) {

                                iov[1].iov_len = (set_Monitoring_header_pkt_cb) (&(connectbuf[con_id]->external_socketID), msg_type);

                        }

                        pkt_len = min(connectbuf[con_id]->pmtusize - iov[2].iov_len - iov[1].iov_len - iov[0].iov_len, msg_len - offset) ;

                        iov[3].iov_len = pkt_len;

                        iov[3].iov_base = msg + offset;

                        //fill header

                        msg_h.len_mon_packet_hdr = iov[1].iov_len;

                        msg_h.offset = htonl(offset);

                        msg_h.msg_length = htonl(truncable ? pkt_len : msg_len);

                        debug("ML: sending packet to %s with rconID:%d lconID:%d\n", conid_to_string(con_id), ntohl(msg_h.remote_con_id), ntohl(msg_h.local_con_id));

                        int priority = 0; 

                        if ((msg_type == ML_CON_MSG)

#ifdef RTX

 || (msg_type == ML_NACK_MSG)

#endif

) priority = HP;

                        //fprintf(stderr,"*******************************ML.C: Sending packet: msg_h.offset: %d msg_h.msg_seq_num: %d\n",ntohl(msg_h.offset),ntohl(msg_h.msg_seq_num));

                        switch(queueOrSendPacket(socketfd, iov, 4, &udpgen.udpaddr,priority)) {

                                case MSGLEN:

                                        info("ML: sending message failed, reducing MTU from %d to %d (to:%s conID:%d lconID:%d msgsize:%d offset:%d)\n", connectbuf[con_id]->pmtusize, pmtu_decrement(connectbuf[con_id]->pmtusize), conid_to_string(con_id), ntohl(msg_h.remote_con_id), ntohl(msg_h.local_con_id), msg_len, offset);

                                        // TODO: pmtu decremented here, but not in the "truncable" packet. That is currently resent without changing the claimed pmtu. Might need to be changed.

                                        connectbuf[con_id]->pmtusize = pmtu_decrement(connectbuf[con_id]->pmtusize);

                                        if (connectbuf[con_id]->pmtusize > 0) {

                                                connectbuf[con_id]->delay = true;

                                                retry = true;

                                        }

                                        offset = msg_len; // exit the while

                                        break;

                                case FAILURE:

                                        info("ML: sending message failed (to:%s conID:%d lconID:%d msgsize:%d msgtype:%d offset:%d)\n", conid_to_string(con_id), ntohl(msg_h.remote_con_id), ntohl(msg_h.local_con_id), msg_len, msg_h.msg_type, offset);

                                        offset = msg_len; // exit the while

                                        break;

                                case THROTTLE:

                                        debug("THROTTLE on output"); 

                                        offset = msg_len; // exit the while

                                        break;

                                case OK:

#ifdef RTX

                                        if (msg_type < 127) counters.sentDataPktCounter++;

#endif

                                        //update

                                        offset += pkt_len;

                                        //transmit data header only in the first packet

                                        iov[2].iov_len = 0;

                                        break;

                        }

                } while(offset != msg_len && !truncable);

        } while(retry);

        //fprintf(stderr, "sentDataPktCounter after msg_seq_num = %d: %d\n", msg_h.msg_seq_num, counters.sentDataPktCounter);

        //fprintf(stderr, "sentRTXDataPktCounter after msg_seq_num = %d: %d\n", msg_h.msg_seq_num, counters.sentRTXDataPktCtr);

}

void pmtu_timeout_cb(int fd, short event, void *arg);

int sendPacket(const int udpSocket, struct iovec *iov, int len, struct sockaddr_in *socketaddr) {

        //monitoring layer hook

        if(get_Send_pkt_inf_cb != NULL && iov[1].iov_len) {

                mon_pkt_inf pkt_info;        

                struct msg_header *msg_h  = (struct msg_header *) iov[0].iov_base;

                memset(iov[1].iov_base,0,iov[1].iov_len);

                pkt_info.remote_socketID = &(connectbuf[ntohl(msg_h->local_con_id)]->external_socketID);

                pkt_info.buffer = iov[3].iov_base;

                pkt_info.bufSize = iov[3].iov_len;

                pkt_info.msgtype = msg_h->msg_type;

                pkt_info.dataID = ntohl(msg_h->msg_seq_num);

                pkt_info.offset = ntohl(msg_h->offset);

                pkt_info.datasize = ntohl(msg_h->msg_length);

                pkt_info.monitoringHeaderLen = iov[1].iov_len;

                pkt_info.monitoringHeader = iov[1].iov_base;

                pkt_info.ttl = -1;

                memset(&(pkt_info.arrival_time),0,sizeof(struct timeval));

                (get_Send_pkt_inf_cb) ((void *) &pkt_info);

        }

         //struct msg_header *msg_h;

    //msg_h = (struct msg_header *) iov[0].iov_base;        

        //fprintf(stderr,"*** Sending packet - msgSeqNum: %d offset: %d\n",ntohl(msg_h->msg_seq_num),ntohl(msg_h->offset));

        return sendPacketFinal(udpSocket, iov, len, socketaddr);

}

void reschedule_conn_msg(int con_id)

{

        if (connectbuf[con_id]->timeout_event) {

                /* delete old timout */        

                event_del(connectbuf[con_id]->timeout_event);

                event_free(connectbuf[con_id]->timeout_event);

        }

        connectbuf[con_id]->timeout_event = event_new(base, -1, EV_TIMEOUT, &pmtu_timeout_cb, (void *) (long)con_id);

        evtimer_add(connectbuf[con_id]->timeout_event, &connectbuf[con_id]->timeout_value);

}

void send_conn_msg(int con_id, int buf_size, int command_type)

{

        if (buf_size < sizeof(struct conn_msg)) {

                error("ML: requested connection message size is too small\n");

                return;

        }

        if(connectbuf[con_id]->ctrl_msg_buf == NULL) {

                connectbuf[con_id]->ctrl_msg_buf = malloc(buf_size);

                memset(connectbuf[con_id]->ctrl_msg_buf, 0, buf_size);

        }

        if(connectbuf[con_id]->ctrl_msg_buf == NULL) {

                error("ML: can not allocate memory for connection message\n");

                return;

        }

        struct conn_msg *msg_header = (struct conn_msg*) connectbuf[con_id]->ctrl_msg_buf;

        msg_header->comand_type = command_type;

        msg_header->pmtu_size = connectbuf[con_id]->pmtusize;

        memcpy(&(msg_header->sock_id), loc_socketID, sizeof(socket_ID));

  {

                        char buf[SOCKETID_STRING_SIZE];

                        mlSocketIDToString(&((struct conn_msg*)connectbuf[con_id]->ctrl_msg_buf)->sock_id,buf,sizeof(buf));

                        debug("Local socket_address sent in INVITE: %s, sizeof msg %ld\n", buf, sizeof(struct conn_msg));

   }

        send_msg(con_id, ML_CON_MSG, connectbuf[con_id]->ctrl_msg_buf, buf_size, true, &(connectbuf[con_id]->defaultSendParams));

}

void send_conn_msg_with_pmtu_discovery(int con_id, int buf_size, int command_type)

{

        struct timeval tout = {0,0};

        tout.tv_usec = PMTU_TIMEOUT * (1.0+ 0.1 *((double)rand()/(double)RAND_MAX-0.5));

        connectbuf[con_id]->timeout_value = tout;

        connectbuf[con_id]->trials = 1;

        send_conn_msg(con_id, buf_size, command_type);

        reschedule_conn_msg(con_id);

}

void resend_conn_msg(int con_id)

{

        connectbuf[con_id]->trials++;

        send_conn_msg(con_id, connectbuf[con_id]->pmtusize, connectbuf[con_id]->status);

        reschedule_conn_msg(con_id);

}

void recv_conn_msg(struct msg_header *msg_h, char *msgbuf, int msg_size, struct sockaddr_in *recv_addr)

{

        struct conn_msg *con_msg;

        int free_con_id, con_id;

        time_t now = time(NULL);

        double timediff = 0.0;

        char sock_id_str[1000];

        msgbuf += msg_h->len_mon_data_hdr;

        msg_size -= msg_h->len_mon_data_hdr;

        con_msg = (struct conn_msg *)msgbuf;

        //verify message validity

        if (msg_size < sizeof(struct conn_msg)) {

                char recv_addr_str[INET_ADDRSTRLEN];

                inet_ntop(AF_INET, &(recv_addr->sin_addr.s_addr), recv_addr_str, INET_ADDRSTRLEN);

                info("Invalid conn_msg received from %s\n", recv_addr_str);

                return;

        }

        //decode sock_id for debug messages

        mlSocketIDToString(&con_msg->sock_id,sock_id_str,999);

        if (con_msg->sock_id.internal_addr.udpaddr.sin_addr.s_addr != recv_addr->sin_addr.s_addr &&

            con_msg->sock_id.external_addr.udpaddr.sin_addr.s_addr != recv_addr->sin_addr.s_addr   ) {

                char recv_addr_str[INET_ADDRSTRLEN];

                inet_ntop(AF_INET, &(recv_addr->sin_addr.s_addr), recv_addr_str, INET_ADDRSTRLEN);

                info("Conn msg received from %s, but claims to be from %s", recv_addr_str, sock_id_str);

                return;

        }

        // Monitoring layer hook

        if(get_Recv_data_inf_cb != NULL) {

                // update pointer to the real data

                mon_data_inf recv_data_inf;

                recv_data_inf.remote_socketID = &(con_msg->sock_id);

                recv_data_inf.buffer = msgbuf;

                recv_data_inf.bufSize = msg_size;

                recv_data_inf.msgtype = msg_h->msg_type;

                recv_data_inf.monitoringDataHeaderLen = msg_h->len_mon_data_hdr;

                recv_data_inf.monitoringDataHeader = msg_h->len_mon_data_hdr ? msgbuf : NULL;

                gettimeofday(&recv_data_inf.arrival_time, NULL);

                recv_data_inf.firstPacketArrived = true;

                recv_data_inf.recvFragments = 1;

                recv_data_inf.priority = false;

                recv_data_inf.padding = false;

                recv_data_inf.confirmation = false;

                recv_data_inf.reliable = false;

                // send data recv callback to monitoring module

                (get_Recv_data_inf_cb) ((void *) &recv_data_inf);

        }

        // check the connection command type

        switch (con_msg->comand_type) {

                /*

                * if INVITE: enter a new socket make new entry in connect array

                * send an ok

                */

                case INVITE:

                        info("ML: received INVITE from %s (size:%d)\n", sock_id_str, msg_size);

                        /*

                        * check if another connection for the external connectionID exist

                        * that was established within the last 2 seconds

                        */

                        free_con_id = -1;

                        for (con_id = 0; con_id < CONNECTBUFSIZE; con_id++) {

                                if (connectbuf[con_id] != NULL) {

                                        if (mlCompareSocketIDs(&(connectbuf[con_id]->external_socketID), &(con_msg->sock_id)) == 0) {

                                                //timediff = difftime(now, connectbuf[con_id]->starttime);        //TODO: why this timeout? Shouldn't the connection be closed instead if there is a timeout?

                                                //if (timediff < 2)

                                                //update remote connection ID

                                                if (connectbuf[con_id]->external_connectionID != msg_h->local_con_id) {

                                                        warn("ML: updating remote connection ID for %s: from %d to %d\n",sock_id_str, connectbuf[con_id]->external_connectionID, msg_h->local_con_id);

                                                        connectbuf[con_id]->external_connectionID = msg_h->local_con_id;

                                                }

                                                break;

                                        }

                                } else if(free_con_id == -1)

                                        free_con_id = con_id;

                        }

                        if (con_id == CONNECTBUFSIZE) {

                                // create an entry in the connecttrybuf

                                if(free_con_id == -1) {

                                        error("ML: no new connect_buf available\n");

                                        return;

                                }

                                connectbuf[free_con_id] = (connect_data *) malloc(sizeof(connect_data));

                                memset(connectbuf[free_con_id],0,sizeof(connect_data));

                                connectbuf[free_con_id]->connection_head = connectbuf[free_con_id]->connection_last = NULL;

                                connectbuf[free_con_id]->starttime = time(NULL);

                                memcpy(&(connectbuf[free_con_id]->external_socketID), &(con_msg->sock_id), sizeof(socket_ID));

                //Workaround to support reuse of socketID

                                connectbuf[free_con_id]->external_socketID.internal_addr.udpaddr.sin_family=AF_INET;

                                connectbuf[free_con_id]->external_socketID.external_addr.udpaddr.sin_family=AF_INET;

                                connectbuf[free_con_id]->pmtusize = con_msg->pmtu_size;        // bootstrap pmtu from the other's size. Not strictly needed, but a good hint

                                connectbuf[free_con_id]->timeout_event = NULL;

                                connectbuf[free_con_id]->external_connectionID = msg_h->local_con_id;

                                connectbuf[free_con_id]->internal_connect =

                                        !compare_external_address_socketIDs(&(con_msg->sock_id), loc_socketID);

                                con_id = free_con_id;

                        }

                        //if(connectbuf[con_id]->status <= CONNECT) { //TODO: anwer anyway. Why the outher would invite otherwise?

                                //update status and send back answer

                                connectbuf[con_id]->status = CONNECT;

                                send_conn_msg_with_pmtu_discovery(con_id, con_msg->pmtu_size, CONNECT);

                        //}

                        break;

                case CONNECT:

                        info("ML: received CONNECT from %s (size:%d)\n", sock_id_str, msg_size);

                        if(msg_h->remote_con_id != -1 && connectbuf[msg_h->remote_con_id] == NULL) {

                                error("ML: received CONNECT for inexistent connection rconID:%d\n",msg_h->remote_con_id);

                                return;

                        }

                        /*

                        * check if the connection status is not already 1 or 2

                        */

                        if (connectbuf[msg_h->remote_con_id]->status == INVITE) {

                                // set the external connectionID

                                connectbuf[msg_h->remote_con_id]->external_connectionID = msg_h->local_con_id;

                                // change status con_msg the connection_data

                                connectbuf[msg_h->remote_con_id]->status = READY;

                                // change pmtusize in the connection_data: not needed. receiving a CONNECT means our INVITE went through. So why change pmtu?

                                //connectbuf[msg_h->remote_con_id]->pmtusize = con_msg->pmtu_size;

                                // send the READY

                                send_conn_msg_with_pmtu_discovery(msg_h->remote_con_id, con_msg->pmtu_size, READY);

                                if (receive_Connection_cb != NULL)

                                        (receive_Connection_cb) (msg_h->remote_con_id, NULL);

                                // call all registered callbacks

                                while(connectbuf[msg_h->remote_con_id]->connection_head != NULL) {

                                        struct receive_connection_cb_list *temp;

                                        temp = connectbuf[msg_h->remote_con_id]->connection_head;

                                        (temp->connection_cb) (msg_h->remote_con_id, temp->arg);

                                        connectbuf[msg_h->remote_con_id]->connection_head = temp->next;

                                        free(temp);

                                }

                                connectbuf[msg_h->remote_con_id]->connection_head =

                                        connectbuf[msg_h->remote_con_id]->connection_last = NULL;

                        } else {

                                // send the READY

                                send_conn_msg_with_pmtu_discovery(msg_h->remote_con_id, con_msg->pmtu_size, READY);

                        }

                        debug("ML: active connection established\n");

                        break;

                        /*

                        * if READY: find the entry in the connection array set the

                        * connection active change the pmtu size

                        */

                case READY:

                        info("ML: received READY from %s (size:%d)\n", sock_id_str, msg_size);

                        if(connectbuf[msg_h->remote_con_id] == NULL) {

                                error("ML: received READY for inexistent connection\n");

                                return;

                        }

                        /*

                        * checks if the connection is not already established

                        */

                        if (connectbuf[msg_h->remote_con_id]->status == CONNECT) {

                                // change status of the connection

                                connectbuf[msg_h->remote_con_id]->status = READY;

                                // change pmtusize: not needed. pmtu doesn't have to be symmetric

                                //connectbuf[msg_h->remote_con_id]->pmtusize = con_msg->pmtu_size;

                                if (receive_Connection_cb != NULL)

                                        (receive_Connection_cb) (msg_h->remote_con_id, NULL);

                                while(connectbuf[msg_h->remote_con_id]->connection_head != NULL) {

                                        struct receive_connection_cb_list *temp;

                                        temp = connectbuf[msg_h->remote_con_id]->connection_head;

                                        (temp->connection_cb) (msg_h->remote_con_id, temp->arg);

                                        connectbuf[msg_h->remote_con_id]->connection_head = temp->next;

                                        free(temp);

                                }

                                connectbuf[msg_h->remote_con_id]->connection_head =

                                        connectbuf[msg_h->remote_con_id]->connection_last = NULL;

                                debug("ML: passive connection established\n");

                        }

                        break;

        }

}

void recv_stun_msg(char *msgbuf, int recvSize)

{

        /*

        * create empty stun message struct

        */

        StunMessage resp;

        memset(&resp, 0, sizeof(StunMessage));

        /*

        * parse the message

        */

        int returnValue = 0;

        returnValue = recv_stun_message(msgbuf, recvSize, &resp);

        if (returnValue == 0) {

                /*

                * read the reflexive Address into the local_socketID

                */

                struct sockaddr_in reflexiveAddr = {0};

                reflexiveAddr.sin_family = AF_INET;

                reflexiveAddr.sin_addr.s_addr = htonl(resp.mappedAddress.ipv4.addr);

                reflexiveAddr.sin_port = htons(resp.mappedAddress.ipv4.port);

                socketaddrgen reflexiveAddres = {0};

                reflexiveAddres.udpaddr = reflexiveAddr;

                local_socketID.external_addr = reflexiveAddres;

                NAT_traversal = true;

                // callback to the upper layer indicating that the socketID is now

                // ready to use

                {

                        char buf[SOCKETID_STRING_SIZE];

                        mlSocketIDToString(&local_socketID,buf,sizeof(buf));

                         debug("received local socket_address: %s\n", buf);

                }

                (receive_SocketID_cb) (&local_socketID, 0);

        }

}

//done

void recv_timeout_cb(int fd, short event, void *arg)

{

        int recv_id = (long) arg;

        debug("ML: recv_timeout_cb called. Timeout for id:%d\n",recv_id);

        if (recvdatabuf[recv_id] == NULL) {

                return;

        }

/*        if(recvdatabuf[recv_id]->status == ACTIVE) {

                //TODO make timeout at least a DEFINE

                struct timeval timeout = { 4, 0 };

                recvdatabuf[recv_id]->status = INACTIVE;

                event_base_once(base, -1, EV_TIMEOUT, recv_timeout_cb,

                        arg, &timeout);

                return;

        }

*/

        if(recvdatabuf[recv_id]->status == ACTIVE) {

                // Monitoring layer hook

                if(get_Recv_data_inf_cb != NULL) {

                        mon_data_inf recv_data_inf;

                        recv_data_inf.remote_socketID =

                                        &(connectbuf[recvdatabuf[recv_id]->connectionID]->external_socketID);

                        recv_data_inf.buffer = recvdatabuf[recv_id]->recvbuf;

                        recv_data_inf.bufSize = recvdatabuf[recv_id]->bufsize;

                        recv_data_inf.msgtype = recvdatabuf[recv_id]->msgtype;

                        recv_data_inf.monitoringDataHeaderLen = recvdatabuf[recv_id]->monitoringDataHeaderLen;

                        recv_data_inf.monitoringDataHeader = recvdatabuf[recv_id]->monitoringDataHeaderLen ?

                                recvdatabuf[recv_id]->recvbuf : NULL;

                        gettimeofday(&recv_data_inf.arrival_time, NULL);

                        recv_data_inf.firstPacketArrived = recvdatabuf[recv_id]->firstPacketArrived;

                        recv_data_inf.recvFragments = recvdatabuf[recv_id]->recvFragments;

                        recv_data_inf.priority = false;

                        recv_data_inf.padding = false;

                        recv_data_inf.confirmation = false;

                        recv_data_inf.reliable = false;

                        // send data recv callback to monitoring module

//                        (get_Recv_data_inf_cb) ((void *) &recv_data_inf);

                }

                // Get the right callback

                receive_data_cb receive_data_callback = recvcbbuf[recvdatabuf[recv_id]->msgtype];

                recv_params rParams;

                rParams.nrMissingBytes = recvdatabuf[recv_id]->bufsize - recvdatabuf[recv_id]->arrivedBytes;

                rParams.recvFragments = recvdatabuf[recv_id]->recvFragments;

                rParams.msgtype = recvdatabuf[recv_id]->msgtype;

                rParams.connectionID = recvdatabuf[recv_id]->connectionID;

                rParams.remote_socketID =

                        &(connectbuf[recvdatabuf[recv_id]->connectionID]->external_socketID);

                rParams.firstPacketArrived = recvdatabuf[recv_id]->firstPacketArrived;

#ifdef RTX

                counters.receivedIncompleteMsgCounter++;

                //mlShowCounters();

                //fprintf(stderr,"******Cleaning slot for inclomplete msg_seq_num: %d\n", recvdatabuf[recv_id]->seqnr);                

#endif

                 //(receive_data_callback) (recvdatabuf[recv_id]->recvbuf + recvdatabuf[recv_id]->monitoringDataHeaderLen, recvdatabuf[recv_id]->bufsize - recvdatabuf[recv_id]->monitoringDataHeaderLen, recvdatabuf[recv_id]->msgtype, &rParams);

                //clean up

                if (recvdatabuf[recv_id]->timeout_event) {

                        event_del(recvdatabuf[recv_id]->timeout_event);

                        event_free(recvdatabuf[recv_id]->timeout_event);

                        recvdatabuf[recv_id]->timeout_event = NULL;

                }

                free(recvdatabuf[recv_id]->recvbuf);

                free(recvdatabuf[recv_id]);

                recvdatabuf[recv_id] = NULL;

        }

}

// process a single recv data message

void recv_data_msg(struct msg_header *msg_h, char *msgbuf, int bufsize)

{

        debug("ML: received packet of size %d with rconID:%d lconID:%d type:%d offset:%d inlength: %d\n",bufsize,msg_h->remote_con_id,msg_h->local_con_id,msg_h->msg_type,msg_h->offset, msg_h->msg_length);

        int recv_id, free_recv_id = -1;

        if(connectbuf[msg_h->remote_con_id] == NULL) {

                debug("ML: Received a message not related to any opened connection!\n");

                return;

        }

#ifdef RTX

        counters.receivedDataPktCounter++;

#endif        

        // check if a recv_data exist and enter data

        for (recv_id = 0; recv_id < RECVDATABUFSIZE; recv_id++) {

                if (recvdatabuf[recv_id] != NULL) {

                        if (msg_h->remote_con_id == recvdatabuf[recv_id]->connectionID &&

                                        msg_h->msg_seq_num == recvdatabuf[recv_id]->seqnr)

                                                break;

                } else

                        if(free_recv_id == -1)

                                free_recv_id = recv_id;

  }

        if(recv_id == RECVDATABUFSIZE) {

                debug(" recv id not found (free found: %d)\n", free_recv_id);

                //no recv_data found: create one

                recv_id = free_recv_id;

                recvdatabuf[recv_id] = (recvdata *) malloc(sizeof(recvdata));

                memset(recvdatabuf[recv_id], 0, sizeof(recvdata));

                recvdatabuf[recv_id]->connectionID = msg_h->remote_con_id;

                recvdatabuf[recv_id]->seqnr = msg_h->msg_seq_num;

                recvdatabuf[recv_id]->monitoringDataHeaderLen = msg_h->len_mon_data_hdr;

                recvdatabuf[recv_id]->bufsize = msg_h->msg_length + msg_h->len_mon_data_hdr;

                recvdatabuf[recv_id]->recvbuf = (char *) malloc(recvdatabuf[recv_id]->bufsize);

                recvdatabuf[recv_id]->arrivedBytes = 0;        //count this without the Mon headers

#ifdef RTX

                recvdatabuf[recv_id]->txConnectionID = msg_h->local_con_id;

                recvdatabuf[recv_id]->expectedOffset = 0;

                recvdatabuf[recv_id]->gapCounter = 0;

                recvdatabuf[recv_id]->firstGap = 0;

                recvdatabuf[recv_id]->last_pkt_timeout_event = NULL;

#endif

                /*

                * read the timeout data and set it

                */

                recvdatabuf[recv_id]->timeout_value = recv_timeout;

                recvdatabuf[recv_id]->timeout_event = NULL;

                recvdatabuf[recv_id]->recvID = recv_id;

                recvdatabuf[recv_id]->starttime = time(NULL);

                recvdatabuf[recv_id]->msgtype = msg_h->msg_type;

                // fill the buffer with zeros

                memset(recvdatabuf[recv_id]->recvbuf, 0, recvdatabuf[recv_id]->bufsize);

                debug(" new @ id:%d\n",recv_id);

        } else {        //message structure already exists, no need to create new

                debug(" found @ id:%d (arrived before this packet: bytes:%d fragments%d\n",recv_id, recvdatabuf[recv_id]->arrivedBytes, recvdatabuf[recv_id]->recvFragments);

        }

        //if first packet extract mon data header and advance pointer

        if (msg_h->offset == 0) {

                //fprintf(stderr,"Hoooooray!! We have first packet of some message!!\n");

                memcpy(recvdatabuf[recv_id]->recvbuf, msgbuf, msg_h->len_mon_data_hdr);

                msgbuf += msg_h->len_mon_data_hdr;

                bufsize -= msg_h->len_mon_data_hdr;

                recvdatabuf[recv_id]->firstPacketArrived = 1;

        }

        // increment fragmentnr

        recvdatabuf[recv_id]->recvFragments++;

        // increment the arrivedBytes

        recvdatabuf[recv_id]->arrivedBytes += bufsize; 

        //fprintf(stderr,"Arrived bytes: %d Offset: %d Expected offset: %d\n",recvdatabuf[recv_id]->arrivedBytes/1349,msg_h->offset/1349,recvdatabuf[recv_id]->expectedOffset/1349);

        // enter the data into the buffer

        memcpy(recvdatabuf[recv_id]->recvbuf + msg_h->len_mon_data_hdr + msg_h->offset, msgbuf, bufsize);

#ifdef RTX

        // detecting a new gap        

        if (msg_h->offset > recvdatabuf[recv_id]->expectedOffset) {

                recvdatabuf[recv_id]->gapArray[recvdatabuf[recv_id]->gapCounter].offsetFrom = recvdatabuf[recv_id]->expectedOffset;

                recvdatabuf[recv_id]->gapArray[recvdatabuf[recv_id]->gapCounter].offsetTo = msg_h->offset;

                if (recvdatabuf[recv_id]->gapCounter < RTX_MAX_GAPS - 1) recvdatabuf[recv_id]->gapCounter++;

                evtimer_add(event_new(base, -1, EV_TIMEOUT, &pkt_recv_timeout_cb, (void *) (long)recv_id), &pkt_recv_timeout);

        }

        //filling the gap by delayed packets

        if (msg_h->offset < recvdatabuf[recv_id]->expectedOffset){

                counters.receivedRTXDataPktCounter++;

                //skip retransmitted packets

                if (recvdatabuf[recv_id]->firstGap < recvdatabuf[recv_id]->gapCounter && msg_h->offset >= recvdatabuf[recv_id]->gapArray[recvdatabuf[recv_id]->firstGap].offsetFrom) {

                        int i;

                        //fprintf(stderr,"firstGap: %d        gapCounter: %d\n", recvdatabuf[recv_id]->firstGap, recvdatabuf[recv_id]->gapCounter);

                        for (i = recvdatabuf[recv_id]->firstGap; i < recvdatabuf[recv_id]->gapCounter; i++){

                                if (msg_h->offset == recvdatabuf[recv_id]->gapArray[i].offsetFrom) {

                                        recvdatabuf[recv_id]->gapArray[i].offsetFrom += bufsize;

                                        break;

                                }

                                if (msg_h->offset == (recvdatabuf[recv_id]->gapArray[i].offsetTo - bufsize)) {

                                        recvdatabuf[recv_id]->gapArray[i].offsetTo -= bufsize;

                                        break;

                                }

                        }

                } else {//fprintf(stderr,"Skipping retransmitted packets in filling the gap.\n"); 

                        //counters.receivedRTXDataPktCounter++;

                        }

        }

        //updating the expectedOffset        

        if (msg_h->offset >= recvdatabuf[recv_id]->expectedOffset) recvdatabuf[recv_id]->expectedOffset = msg_h->offset + bufsize;

#endif

        //TODO very basic checkif all fragments arrived: has to be reviewed

        if(recvdatabuf[recv_id]->arrivedBytes == recvdatabuf[recv_id]->bufsize - recvdatabuf[recv_id]->monitoringDataHeaderLen)

                recvdatabuf[recv_id]->status = COMPLETE; //buffer full -> msg completly arrived

        else

                recvdatabuf[recv_id]->status = ACTIVE;

        if (recv_data_callback) {

                if(recvdatabuf[recv_id]->status == COMPLETE) {

                        // Monitoring layer hook

                        if(get_Recv_data_inf_cb != NULL) {

                                mon_data_inf recv_data_inf;

                                recv_data_inf.remote_socketID =

                                         &(connectbuf[recvdatabuf[recv_id]->connectionID]->external_socketID);

                                recv_data_inf.buffer = recvdatabuf[recv_id]->recvbuf;