client.c

#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
#include<errno.h>
#include<sys/wait.h>
#include<signal.h>
#include<sys/types.h>
#include<sys/socket.h>
#include<netdb.h>
#include<string.h>
#include<arpa/inet.h>
#include<netinet/in.h>
#include<sys/utsname.h>

#define MAXDATASIZE 1025
#define GET 0
#define ADD 1
#define LOOKUP 2
#define LISTALL 3
#define UPLOADPORT 8000

struct utsname sysname;
char hostname[512];

char* reqHeader(int sockfd,int option,int rfcid,char* title){
	char* temp=NULL;
    char fulltext[2048]="";
    
	if(option == ADD){
		temp = "ADD RFC ";
        
        char rfcid_string[32];
        sprintf(rfcid_string,"%d",rfcid);
        
        char port_string[32];
        sprintf(port_string,"%d",UPLOADPORT);
        
        strcat(fulltext,temp);
        strcat(fulltext,rfcid_string);
        strcat(fulltext," P2P-CI/1.0\nHost: ");
        strcat(fulltext,hostname);
        strcat(fulltext,"\nPort: ");
        strcat(fulltext,port_string);
        strcat(fulltext,"\nTitle: ");
        strcat(fulltext,title);
        strcat(fulltext,"\0");
        
        printf("Sending %s\n",fulltext);
        
	}else if(option == LOOKUP){
        
		temp = "LOOKUP RFC ";
        char rfcid_string[32];
        sprintf(rfcid_string,"%d",rfcid);
        
        char port_string[32];
        sprintf(port_string,"%d",UPLOADPORT);
        
        strcat(fulltext,temp);
        strcat(fulltext,rfcid_string);
        strcat(fulltext," P2P-CI/1.0\nHost: ");
        strcat(fulltext,hostname);
        strcat(fulltext,"\nPort: ");
        strcat(fulltext,port_string);
        strcat(fulltext,"\0");
       
        printf("Sending %s\n",fulltext);
 
	}else if(option == LISTALL){
        
        temp = "LIST ALL ";
        
        char port_string[32];
        sprintf(port_string,"%d",UPLOADPORT);
        
        strcat(fulltext,temp);
        strcat(fulltext," P2P-CI/1.0\nHost: ");
        strcat(fulltext,hostname);
        strcat(fulltext,"\nPort: ");
        strcat(fulltext,port_string);
        strcat(fulltext,"\0");
        
        printf("Sending %s\n",fulltext);

        
	}else if(option == GET){
        
        temp = "GET RFC ";
        
        char rfcid_string[32];
        sprintf(rfcid_string,"%d",rfcid);
        
        strcat(fulltext,temp);
        strcat(fulltext,rfcid_string);
        strcat(fulltext," P2P-CI/1.0\nHost: ");
        strcat(fulltext,hostname);
        strcat(fulltext,"\nOS: ");
        strcat(fulltext,sysname.sysname);
        strcat(fulltext," ");
        strcat(fulltext,sysname.release);
        
    }
	
    sleep(1);
    
    if(send(sockfd,fulltext,strlen(fulltext),0) == -1)
        perror("send");
    
	return fulltext;
}

//This method is used to initialize the client by sending rfc details to the server
int initClient(int sockfd){
    
    printf("Initializing client\n");
    
    FILE *fp;
    int id,numbytes;
    char title[256];
    char* buf;
    
    fp = fopen("index.txt","r");
    if(fp == NULL){
        perror("Rfc index not found");
        exit(-1);
    }
    
    while(fscanf(fp,"%d %[^\t\n]",&id,title) == 2){
        //Send add requests to the server
        reqHeader(sockfd,ADD,id,title);
        buf=(char *)malloc(MAXDATASIZE);
        numbytes = recv(sockfd,buf,MAXDATASIZE-1,0);
        buf[numbytes] = '\0';
        
        printf("Response from server : %s\n\n",buf);
    }
    
    fclose(fp);
    return 0;
}

void *get_in_addr(struct sockaddr *sa){
	if(sa->sa_family == AF_INET){
		return &(((struct sockaddr_in*)sa)->sin_addr);
    }

    return &(((struct sockaddr_in6*)sa)->sin6_addr);
}

int sendGet(int sockfd,int rfcid){
    printf("Get request for : %d\n",rfcid);
    reqHeader(sockfd,GET,rfcid,NULL);
    
}

int sendLookup(int sockfd, int rfcid){

    char* buf;
    int numbytes;
    
    reqHeader(sockfd,LOOKUP,rfcid,NULL);
    buf=(char *)malloc(MAXDATASIZE);
    numbytes = recv(sockfd,buf,MAXDATASIZE-1,0);
    buf[numbytes] = '\0';
    
    printf("Response from server : %s\n\n",buf);

}

int sendList(int sockfd){
    
    char* buf;
    int numbytes;
    
    reqHeader(sockfd,LISTALL,NULL,NULL);
    buf=(char *)malloc(MAXDATASIZE);
    numbytes = recv(sockfd,buf,MAXDATASIZE-1,0);
    buf[numbytes] = '\0';
    
    printf("Response from server : %s\n",buf);
    
}

int main(int argc,char *argv[]){

	char* PORTNO = "5540";
	char* SERVERIP = "127.0.0.1";

    //Populate the OS name
    if(uname(&sysname)){
        perror("Error obtaining os name");
        exit(-1);
    }
    
	hostname[511]='\0';
	gethostname(hostname,511);

	char *buf;
	int status,sockfd,numbytes;
	struct addrinfo hints,*res,*me;
	socklen_t addr_size;
	char s[INET6_ADDRSTRLEN];
	
	//Server details
	memset(&hints,0,sizeof(hints));
	hints.ai_family = AF_UNSPEC;
	hints.ai_socktype = SOCK_STREAM;
	
	getaddrinfo(SERVERIP,PORTNO,&hints,&res);
	
	//Create a socket
	if((sockfd = socket(res->ai_family,res->ai_socktype,res->ai_protocol)) == -1){
		perror("Server:socket creating error");
	}
	
	if(connect(sockfd,res->ai_addr,res->ai_addrlen) == -1){
		close(sockfd);
		perror("Client : Connect");
		exit(1);
	}
	
	inet_ntop(res->ai_family,get_in_addr((struct sockaddr *)res->ai_addr),s,sizeof(s));
	gethostname(hostname,1023);
	printf("Hostname : %s\n",hostname);
	printf("Client connecting to : %s\n",s);

    initClient(sockfd);
    
    sendLookup(sockfd,789);
    
    sendList(sockfd);
    
	close(sockfd);
    
	return 0;
}