PeerStreamer

/*

 *  Copyright (c) 2009 Marco Biazzini

 *

 *  This is free software; see lgpl-2.1.txt

 */

#include <event2/event.h>

#include <arpa/inet.h>

#include <unistd.h>

#include <stdlib.h>

#include <stdio.h>

#include <string.h>

#include "net_helper.h"

#include "ml.h"

#include "ml_helpers.h"

/**

 * libevent pointer

 */

struct event_base *base;

#define NH_BUFFER_SIZE 100

static int sIdx = 0;

static int rIdx = 0;

typedef struct nodeID {

        socketID_handle addr;

        int connID;        // connection associated to this node, -1 if myself

        int refcnt;

//        int addrSize;

//        int addrStringSize;

} nodeID;

typedef struct msgData_cb {

        int bIdx;        // index of the message in the proper buffer

        unsigned char msgType; // message type

        int mSize;        // message size

} msgData_cb;

static nodeID *me; //TODO: is it possible to get rid of this (notwithstanding ml callback)??

static int timeoutFired = 0;

// pointers to the msgs to be send

static uint8_t *sendingBuffer[NH_BUFFER_SIZE];

// pointers to the received msgs + sender nodeID

static uint8_t *receivedBuffer[NH_BUFFER_SIZE][2];

/**/ static int recv_counter =0;

/**

 * Look for a free slot in the received buffer and allocates it for immediate use

 * @return the index of a free slot in the received msgs buffer, -1 if no free slot available.

 */

static int next_R() {

        const int size = 1024;

        if (receivedBuffer[rIdx][0]==NULL) {

                receivedBuffer[rIdx][0] = malloc(size);

        }

        else {

                int count;

                for (count=0;count<NH_BUFFER_SIZE;count++) {

                        rIdx = (++rIdx)%NH_BUFFER_SIZE;

                        if (receivedBuffer[rIdx][0]==NULL)

                                break;

                }

                if (count==NH_BUFFER_SIZE)

                        return -1;

                else {

                        receivedBuffer[rIdx][0] = malloc(size);

                }

        }

        memset(receivedBuffer[rIdx][0],0,size);

        return rIdx;

}

/**

 * Look for a free slot in the sending buffer and allocates it for immediate use

 * @return the index of a free slot in the sending msgs buffer, -1 if no free slot available.

 */

static int next_S() {

        const int size = 1024;

        if (sendingBuffer[sIdx]==NULL) {

                sendingBuffer[sIdx] = malloc(size);

        }

        else {

                int count;

                for (count=0;count<NH_BUFFER_SIZE;count++) {

                        sIdx = (++sIdx)%NH_BUFFER_SIZE;

                        if (sendingBuffer[sIdx]==NULL)

                                break;

                }

                if (count==NH_BUFFER_SIZE)

                        return -1;

                else {

                        sendingBuffer[sIdx] = malloc(size);

                }

        }

        return sIdx;

}

/**

 * Callback used by ml to confirm its initialization. Create a valid self nodeID and register to receive data from remote peers.

 * @param local_socketID

 * @param errorstatus

 */

static void init_myNodeID_cb (socketID_handle local_socketID,int errorstatus) {

        switch (errorstatus) {

        case 0:

                //

                memcpy(me->addr,local_socketID,SOCKETID_SIZE);

        //        me->addrSize = SOCKETID_SIZE;

        //        me->addrStringSize = SOCKETID_STRING_SIZE;

                me->connID = -1;

                me->refcnt = 1;

        //        fprintf(stderr,"Net-helper init : received my own socket: %s.\n",node_addr(me));

                break;

        case -1:

                //

                fprintf(stderr,"Net-helper init : socket error occurred in ml while creating socket\n");

                exit(1);

                break;

        case 1:

                //

                fprintf(stderr,"Net-helper init : NAT traversal failed while creating socket\n");

                exit(1);

                break;

        case 2:

            fprintf(stderr,"Net-helper init : NAT traversal timeout while creating socket\n");

            exit(2);

            break;

        default :        // should never happen

                //

                fprintf(stderr,"Net-helper init : Unknown error in ml while creating socket\n");

        }

}

/**

 * Timeout callback to be set in the eventlib loop as needed

 * @param socket

 * @param flag

 * @param arg

 */

static void t_out_cb (int socket, short flag, void* arg) {

        timeoutFired = 1;

//        fprintf(stderr,"TIMEOUT!!!\n");

//        event_base_loopbreak(base);

}

/**

 * Callback called by ml when a remote node ask for a connection

 * @param connectionID

 * @param arg

 */

static void receive_conn_cb(int connectionID, void *arg) {

//    fprintf(stderr, "Net-helper : remote peer opened the connection %d with arg = %d\n", connectionID,(int)arg);

}

/**

 * Callback called by the ml when a connection is ready to be used to send data to a remote peer

 * @param connectionID

 * @param arg

 */

static void connReady_cb (int connectionID, void *arg) {

        msgData_cb *p;

        p = (msgData_cb *)arg;

        if (p == NULL) return;

        mlSendData(connectionID,(char *)(sendingBuffer[p->bIdx]),p->mSize,p->msgType,NULL);

///**/fprintf(stderr,"Sent message of type # %c and size %d\n",

//                ((char*)sendingBuffer[p->bIdx])[0]+'0', p->mSize);

        free(sendingBuffer[p->bIdx]);

        sendingBuffer[p->bIdx] = NULL;

//        fprintf(stderr,"Net-helper: Message # %d for connection %d sent!\n ", p->bIdx,connectionID);

        //        event_base_loopbreak(base);

        free(p);

}

/**

 * Callback called by ml when a connection error occurs

 * @param connectionID

 * @param arg

 */

static void connError_cb (int connectionID, void *arg) {

        // simply get rid of the msg in the buffer....

        msgData_cb *p;

        p = (msgData_cb *)arg;

        if (p != NULL) {

                fprintf(stderr,"Net-helper: Connection %d could not be established to send msg %d.\n ", connectionID,p->bIdx);

                free(sendingBuffer[p->bIdx]);

                sendingBuffer[p->bIdx] = NULL;

                p->mSize = -1;

        }

        //        event_base_loopbreak(base);

}

/**

 * Callback to receive data from ml

 * @param buffer

 * @param buflen

 * @param msgtype

 * @param arg

 */

static void recv_data_cb(char *buffer, int buflen, unsigned char msgtype, recv_params *arg) {

// TODO: lacks a void* arg... moreover: recv_params has a msgtype, but there is also a msgtype explicit argument...

//        fprintf(stderr, "Net-helper : called back with some news...\n");

/**/ ++recv_counter;

        char str[SOCKETID_STRING_SIZE];

        if (arg->remote_socketID != NULL)

                mlSocketIDToString(arg->remote_socketID,str,SOCKETID_STRING_SIZE);

        else

                sprintf(str,"!Unknown!");

        if (arg->nrMissingBytes || !arg->firstPacketArrived) {

            fprintf(stderr, "Net-helper : corrupted message arrived from %s\n",str);

/**/    fprintf(stderr, "\tMessage # %d -- Message type: %c -- Missing # %d frags\n",

                        recv_counter, buffer[0],arg->nrMissingBytes, arg->firstPacketArrived?" => Missing first!":"");

        }

        else {

        //        fprintf(stderr, "Net-helper : message arrived from %s\n",str);

                // buffering the received message only if possible, otherwise ignore it...

                int index = next_R();

                if (index >=0) {

                //        receivedBuffer[index][0] = malloc(buflen);

                        if (receivedBuffer[index][0] == NULL) {

                                fprintf(stderr, "Net-helper : memory error while creating a new message buffer \n");

                                return;

                        }

                        // creating a new sender nodedID

                        receivedBuffer[index][1] = malloc(sizeof(nodeID));

                        if (receivedBuffer[index][1]==NULL) {

                                free (receivedBuffer[index][0]);

                                receivedBuffer[index][0] = NULL;

                                fprintf(stderr, "Net-helper : memory error while creating a new nodeID. Message from %s is lost.\n", str);

                                return;

                        }

                        else {

                                memset(receivedBuffer[index][1], 0, sizeof(struct nodeID));

                                nodeID *remote; remote = (nodeID*)(receivedBuffer[index][1]);

                                receivedBuffer[index][0] = realloc(receivedBuffer[index][0],buflen+sizeof(int));

                                memset(receivedBuffer[index][0],0,buflen+sizeof(int));

                                memcpy(receivedBuffer[index][0],&buflen,sizeof(int));

                                //*(receivedBuffer[index][0]) = buflen;

                                memcpy((receivedBuffer[index][0])+sizeof(int),buffer,buflen);

                                  // get the socketID of the sender

                                remote->addr = malloc(SOCKETID_SIZE);

                                if (remote->addr == NULL) {

                                          free (remote);

                                          fprintf(stderr, "Net-helper : memory error while creating a new nodeID \n");

                                          return;

                                }

                                else {

                                        memset(remote->addr, 0, SOCKETID_SIZE);

                                        memcpy(remote->addr, arg->remote_socketID ,SOCKETID_SIZE);

                                //        remote->addrSize = SOCKETID_SIZE;

                                //        remote->addrStringSize = SOCKETID_STRING_SIZE;

                                        remote->connID = arg->connectionID;

                                        remote->refcnt = 1;

                                }

                        }

                }

  }

//        event_base_loopbreak(base);

}

struct nodeID *net_helper_init(const char *IPaddr, int port) {

        struct timeval tout = {1, 0};

        base = event_base_new();

        me = malloc(sizeof(nodeID));

        if (me == NULL) {

                return NULL;

        }

        memset(me,0,sizeof(nodeID));

        me->addr = malloc(SOCKETID_SIZE);

        if (me->addr == NULL) {

                free(me);

                return NULL;

        }

        memset(me->addr,0,SOCKETID_SIZE);

        me->connID = -10;        // dirty trick to spot later if the ml has called back ...

        me->refcnt = 1;

        int i;

        for (i=0;i<NH_BUFFER_SIZE;i++) {

                sendingBuffer[i] = NULL;

                receivedBuffer[i][0] = NULL;

        }

        mlRegisterErrorConnectionCb(&connError_cb);

        mlRegisterRecvConnectionCb(&receive_conn_cb);

        mlInit(1,tout,port,IPaddr,0,NULL,&init_myNodeID_cb,base);

        while (me->connID<-1) {

        //        event_base_once(base,-1, EV_TIMEOUT, &t_out_cb, NULL, &tout);

                event_base_loop(base,EVLOOP_ONCE);

        }

        timeoutFired = 0;

//        fprintf(stderr,"Net-helper init : back from init!\n");

        return me;

}

void bind_msg_type (unsigned char msgtype) {

                        mlRegisterRecvDataCb(&recv_data_cb,msgtype);

}

/**

 * Called by the application to send data to a remote peer

 * @param from

 * @param to

 * @param buffer_ptr

 * @param buffer_size

 * @return The dimension of the buffer or -1 if a connection error occurred.

 */

int send_to_peer(const struct nodeID *from, struct nodeID *to, const uint8_t *buffer_ptr, int buffer_size)

{

        // if buffer is full, discard the message and return an error flag

        int index = next_S();

        if (index<0) {

                // free(buffer_ptr);

                return -1;

        }

        sendingBuffer[index] = realloc(sendingBuffer[index],buffer_size);

        memset(sendingBuffer[index],0,buffer_size);

        memcpy(sendingBuffer[index],buffer_ptr,buffer_size);

        // free(buffer_ptr);

        msgData_cb *p = malloc(sizeof(msgData_cb));

        p->bIdx = index; p->mSize = buffer_size; p->msgType = (unsigned char)buffer_ptr[0];

        int current = p->bIdx;

        send_params params = {0,0,0,0};

        to->connID = mlOpenConnection(to->addr,&connReady_cb,p, params);

        if (to->connID<0) {

                free(sendingBuffer[current]);

                sendingBuffer[current] = NULL;

                fprintf(stderr,"Net-helper: Couldn't get a connection ID to send msg %d.\n ", p->bIdx);

                free(p);

                return -1;

        }

        else {

                return buffer_size; //p->mSize;

        }

}

/**

 * Called by an application to receive data from remote peers

 * @param local

 * @param remote

 * @param buffer_ptr

 * @param buffer_size

 * @return The number of received bytes or -1 if some error occurred.

 */

int recv_from_peer(const struct nodeID *local, struct nodeID **remote, uint8_t *buffer_ptr, int buffer_size)

{

        int size;

        // this should never happen... if it does, index handling is faulty...

        if (receivedBuffer[rIdx][1]==NULL) {

                fprintf(stderr, "Net-helper : memory error while creating a new nodeID \n");

                return -1;

        }

        (*remote) = (nodeID*)(receivedBuffer[rIdx][1]);

        // retrieve a msg from the buffer

        size = *((int*)(receivedBuffer[rIdx][0]));

        if (size>buffer_size) {

                fprintf(stderr, "Net-helper : recv_from_peer: buffer too small (size:%d > buffer_size: %d)!\n",size,buffer_size);

                return -1;

        }

        memcpy(buffer_ptr, (receivedBuffer[rIdx][0])+sizeof(int), size);

        free(receivedBuffer[rIdx][0]);

        receivedBuffer[rIdx][0] = NULL;

        receivedBuffer[rIdx][1] = NULL;

//        fprintf(stderr, "Net-helper : I've got mail!!!\n");

        return size;

}

int wait4data(const struct nodeID *n, struct timeval *tout) {

//        fprintf(stderr,"Net-helper : Waiting for data to come...\n");

        event_base_once(base,-1, EV_TIMEOUT, &t_out_cb, NULL, tout);

        while(receivedBuffer[rIdx][0]==NULL && timeoutFired==0) {

        //        event_base_dispatch(base);

                event_base_loop(base,EVLOOP_ONCE);

        }

        timeoutFired = 0;

//        fprintf(stderr,"Back from eventlib loop.\n");

        if (receivedBuffer[rIdx][0]!=NULL)

                return 1;

        else

                return 0;

}

struct nodeID *create_node(const char *rem_IP, int rem_port) {

        struct nodeID *remote = malloc(sizeof(nodeID));

        if (remote == NULL) {

                return NULL;

        }

//        remote->addr = malloc(sizeof(SOCKETID_SIZE));

//        if (remote->addr == NULL) {

//                free(remote);

//                return NULL;

//        }

//        remote->addrSize = SOCKETID_SIZE;

//        remote->addrStringSize = SOCKETID_STRING_SIZE;

        remote->addr = getRemoteSocketID(rem_IP, rem_port);

        send_params params = {0,0,0,0};

        remote->connID = mlOpenConnection(remote->addr,&connReady_cb,NULL, params);

        remote->refcnt = 1;

        return remote;

}

// TODO: check why closing the connection is annoying for the ML

void nodeid_free(struct nodeID *n) {

//        mlCloseConnection(n->connID);

//        mlCloseSocket(n->addr);

//        free(n);

        if (n && (--(n->refcnt) == 0)) {

        //        mlCloseConnection(n->connID);

                mlCloseSocket(n->addr);

                free(n);

        }

}

const char *node_addr(const struct nodeID *s)

{

  static char addr[256];

  // TODO: mlSocketIDToString always return 0 !!!

  int r = mlSocketIDToString(s->addr,addr,256);

  if (!r)

          return addr;

  else

          return "";

}

struct nodeID *nodeid_dup(struct nodeID *s)

{

//  struct nodeID *res;

//

//  res = malloc(sizeof(struct nodeID));

//  if (res != NULL) {

//          res->addr = malloc(SOCKETID_SIZE);

//          if (res->addr != NULL) {

//                 memcpy(res->addr, s->addr, SOCKETID_SIZE);

//        //         res->addrSize = SOCKETID_SIZE;

//        //         res->addrStringSize = SOCKETID_STRING_SIZE;

//                 res->connID = s->connID;

//          }

//          else {

//                free(res);

//                res = NULL;

//                fprintf(stderr,"Net-helper : Error while duplicating nodeID...\n");

//          }

//  }

//        return res;

        s->refcnt++;

        return s;

}

int nodeid_equal(const struct nodeID *s1, const struct nodeID *s2)

{

        return (mlCompareSocketIDs(s1->addr,s2->addr) == 0);

}

int nodeid_dump(uint8_t *b, const struct nodeID *s)

{

  mlSocketIDToString(s->addr,(char *)b,SOCKETID_STRING_SIZE);

  //fprintf(stderr,"Dumping nodeID : ho scritto %s (%d bytes)\n",b, strlen((char *)b));

//        memcpy(b, s->addr,SOCKETID_SIZE);//sizeof(struct sockaddr_in6)*2

//        return SOCKETID_SIZE;//sizeof(struct sockaddr_in6)*2;

  return 1 + strlen((char *)b);        //terminating \0 IS included in the size

}

struct nodeID *nodeid_undump(const uint8_t *b, int *len)

{

  struct nodeID *res;

  res = malloc(sizeof(struct nodeID));

  if (res != NULL) {

          memset(res,0,sizeof(struct nodeID));

          res->addr = malloc(SOCKETID_SIZE);

          if (res->addr != NULL) {

                  memset(res->addr,0,SOCKETID_SIZE);

                  //memcpy(res->addr, b, SOCKETID_SIZE);

                  //*len = SOCKETID_SIZE;

                  *len = strlen((char*)b) + 1;

                  mlStringToSocketID((char *)b,res->addr);

        //          fprintf(stderr,"Node undumped : %s\n",node_addr(res));

        //          res->addrSize = SOCKETID_SIZE;

        //          res->addrStringSize = SOCKETID_STRING_SIZE;

                  res->connID = -1;

                  res->refcnt = 1;

          }

          else {

                  free(res);

                  res = NULL;

                  // TODO: what about *len in this case???

                  fprintf(stderr,"Net-helper : Error while 'undumping' nodeID...\n");

          }

  }

  return res;

}