serverA.cpp

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <netdb.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <sys/wait.h>
#include <iostream>
#include <fstream>
using namespace std;
#define SERVERPORT 3333
#define MAXDATASIZE 100
 int data[5];

//output an empty line
void OutPutAnEmptyLine(){
cout<<"\n";
}
//read data from the file, Word by Word
void ReadDataFromFileWBW(){
        ifstream fin("serverA.txt");
        string s;
        data[0] = 1;
// read the neighbor information to the server
    cout<< "The server A has the following neighbor information:"<<endl;
    cout<< "Neighbor-----Cost"<<endl;
        while(fin >> s){
           
            if(s == "serverA"){
                int i = 1;
                fin >> s;
                int cost = atoi(s.c_str());
                data[i] = cost;
                
                cout << "serverA      " << cost << endl;
                
            }
            if(s == "serverB"){
                    int i = 2;
                    fin >> s;
                    int cost = atoi(s.c_str());
                    data[i] = cost;
                 
                    cout << "serverB      " << cost << endl;
                    
                }
            if(s=="serverC"){
                    int i = 3;
                    fin >> s;
                    int cost = atoi(s.c_str());
                    data[i] = cost;
                  
                    cout << "serverC      " << cost << endl;
                }
            if(s == "serverD"){
                    int i =4;
                    fin >> s;
                    int cost = atoi(s.c_str());
                    data[i] = cost;
                   
                    cout << "serverD      " << cost << endl;
                }
            }

}
//create the TCP connection between the server and the client

void serverA_createTCP(){
    int sock_fd;
    char buf[MAXDATASIZE]; //define the max size of the buffer
    struct hostent *host;
    struct sockaddr_in serv_addr, serverA;
    ReadDataFromFileWBW();
    OutPutAnEmptyLine();
    
    
    if((host = gethostbyname("localhost")) == NULL){
        herror("gethostbyname in error!");
        exit(1);
    }
    
//create the socket in the serverA side
    if((sock_fd = socket(AF_INET, SOCK_STREAM, 0)) == -1){
        perror("creat socket in error!");
        exit(1);
    }
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_port = htons(SERVERPORT);
    serv_addr.sin_addr = *((struct in_addr *)host->h_addr);

    
//create the connection between the serverA and the client
    if (connect(sock_fd, (struct sockaddr *)&serv_addr, sizeof(struct sockaddr)) == -1) {
        perror("connect in error!");
        exit(1);
    }
    
//send the neighbor information of serverA to the client
    if(send(sock_fd, data, sizeof(data), 0) == -1){
        perror("send in error!");
        exit(1);
    }
    
    socklen_t lenA = sizeof(serv_addr);
    int socket_name = getsockname(sock_fd, (struct sockaddr *)&serverA, &lenA);
    cout<< "The server A finishes sending its neighbor information to the Client with TCP port number "<<"25748"<<" and IP address "<<inet_ntoa(serverA.sin_addr)<<endl;
    
    cout<<"For this connection with the Client, the Server A has TCP port number "<<ntohs(serverA.sin_port)<<" and IP address "<<inet_ntoa(serverA.sin_addr)<<endl;
    
    close(sock_fd);//close the connection of the TCP connection

}
//create the UDP connection of the serverA and the client
void serverA_createUDP(){
    struct sockaddr_in server_addr,serverA;
   
    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = htonl(INADDR_ANY);
    server_addr.sin_port = htons(21748); // the UDP port number of the serverA
    string x;
    
// create socket of the serverA
    int server_socket_fd = socket(AF_INET, SOCK_DGRAM, 0);
    if(server_socket_fd == -1)
    {
        perror("create socket failed:");
        exit(1);
    }
    
// bind the serverA and the client
    if((bind(server_socket_fd,(struct sockaddr*)&server_addr,sizeof(struct sockaddr_in)))==-1)
    {
        perror("server bind failed:");
        exit(1);
    }
        struct sockaddr_in client_addr;
        socklen_t client_addr_length = sizeof(client_addr);

        int buffer[4][4]; //the buffer to receive the information from the client
      
    
// receive the data from the client
        if(recvfrom(server_socket_fd,buffer,sizeof(buffer),0,(struct sockaddr*)&client_addr, &client_addr_length) == -1){
            perror("receive data failed");
            exit(1);
        }
// to get the port number and IP address of the client and serverA
        socklen_t lenA = sizeof(server_addr);
        int UDP_socket_name = getsockname(server_socket_fd, (struct sockaddr *)&serverA, &lenA);
    
        socklen_t len = sizeof(server_addr);
        int socket_name = getpeername(server_socket_fd, (struct sockaddr *)&client_addr, &len);
    
        cout<<"The server A has received the network tpology from Client with UDP port number "<<ntohs(client_addr.sin_port)<<" and IP address "<<inet_ntoa(client_addr.sin_addr)<<endl;
//print out the connection information of all the server
        cout<<"Edge-----Cost"<<endl;
        
        for(int i=0;i<4;i++){
            for(int j=i;j<5;j++){
                   if(buffer[i][j]!=0){
                       if(i ==0){
                           if(j ==0){
                           cout<<"AA      "<<buffer[0][j]<<endl;
                           }
                           if(j ==1){
                           cout<<"AB      "<<buffer[0][j]<<endl;
                           }
                           if(j ==2){
                               cout<<"AC      "<<buffer[0][j]<<endl;
                           }
                           if(j ==3){
                               cout<<"AD      "<<buffer[0][j]<<endl;
                           }
                       }
                       if(i==1){
                           if(j==1){
                           cout<<"BB      "<<buffer[1][j]<<endl;
                           }
                           if(j ==2){
                           cout<<"BC      "<<buffer[1][j]<<endl;
                           }
                           if(j ==3){
                           cout<<"BD      "<<buffer[1][j]<<endl;
                           }
                       }
                       if(i==2){
                           if(j==2){
                               cout<<"CC      "<<buffer[2][j]<<endl;
                           }
                           if(j ==3){
                               cout<<"CD      "<<buffer[2][j]<<endl;
                           }
                           if(j ==3){
                               cout<<"CD      "<<buffer[2][j]<<endl;
                           }
                       }
                       if(i==3){
                           if(j==3){
                               cout<<"DD      "<<buffer[2][j]<<endl;
                           }
                         
                       }
                    }
                }
            }
    
        
        cout<<"For this connection with Client, the Server A has UDP port number "<<ntohs(serverA.sin_port)<<" and IP address "<<inet_ntoa(client_addr.sin_addr)<< endl;
       
    
    close(server_socket_fd);
    
}


int main(){
  
    cout << "The Server A is up and running."<<endl;
    serverA_createTCP();
    serverA_createUDP();
    return 0;
}