FTP Implementation Using Command line on Linux
in C++
Client.cpp
#include <iostream>
#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <fstream>
#include <string.h>
#include <arpa/inet.h>
using namespace std;
int create_socket(int,char *);
#ifdef WINDOWS
#include <direct.h>
#define GetCurrentDir _getcwd
#else
#include <unistd.h>
#define GetCurrentDir getcwd
#endif
#define MAXLINE 4096 /*max text line length*/
int
main(int argc, char **argv)
{
int sockfd;
struct sockaddr_in servaddr;
char sendline[MAXLINE], recvline[MAXLINE];
//basic check of the arguments
//additional checks can be inserted
if (argc !=3) {
cerr<<"Usage: ./a.out <IP address of the server> <port number>"<<endl;
exit(1);
}
//Create a socket for the client
//If sockfd<0 there was an error in the creation of the socket
if ((sockfd = socket (AF_INET, SOCK_STREAM, 0)) <0) {
cerr<<"Problem in creating the socket"<<endl;
exit(2);
}
//Creation of the socket
memset(&servaddr, 0, sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_addr.s_addr= inet_addr(argv[1]);
servaddr.sin_port = htons(atoi(argv[2])); //convert to big-endian order
//Connection of the client to the socket
if (connect(sockfd, (struct sockaddr *) &servaddr, sizeof(servaddr))<0) {
cerr<<"Problem in connecting to the server"<<endl;
exit(3);
}
cout<<"ftp>";
while (fgets(sendline, MAXLINE, stdin) != NULL) {
send(sockfd, sendline, MAXLINE, 0);
char *token,*dummy;
dummy=sendline;
token=strtok(dummy," ");
if (strcmp("quit\n",sendline)==0) {
//close(sockfd);
return 0;
}
else if (strcmp("ls\n",sendline)==0) {
char buff[MAXLINE],check[MAXLINE]="1",port[MAXLINE];
int data_port,datasock;
recv(sockfd, port, MAXLINE,0); //reciening data connection port
data_port=atoi(port);
datasock=create_socket(data_port,argv[1]);
while(strcmp("1",check)==0){ //to indicate that more blocks are coming
recv(datasock,check,MAXLINE,0);
if(strcmp("0",check)==0) //no more blocks of data
break;
recv(datasock, buff, MAXLINE,0);
cout<<buff;
}
}
else if (strcmp("!ls\n",sendline)==0) {
system("ls");
cout<<"\n";
}
else if (strcmp("pwd\n",sendline)==0) {
char curr_dir[MAXLINE];
recv(sockfd, curr_dir, MAXLINE,0);
cout<<curr_dir<<endl;
}
else if (strcmp("!pwd\n",sendline)==0) {
system("pwd");
}
else if (strcmp("cd",token)==0) {
char check[MAXLINE];
token=strtok(NULL," \n");
cout<<"Path given is: "<<token<<endl;
recv(sockfd,check,MAXLINE,0);
if(strcmp("0",check)==0){
cerr<<"Directory doesn't exist. Check Path"<<endl;
}
}
else if (strcmp("!cd",token)==0) {
token=strtok(NULL," \n");
cout<<"Path given is: "<<token<<endl;
if(chdir(token)<0){
cerr<<"Directory doesn't exist. Check path"<<endl;
}
}
else if (strcmp("put",token)==0) {
char port[MAXLINE], buffer[MAXLINE],char_num_blks[MAXLINE],char_num_last_blk[MAXLINE];
int data_port,datasock,lSize,num_blks,num_last_blk,i;
FILE *fp;
recv(sockfd, port, MAXLINE,0); //receiving the data port
data_port=atoi(port);
datasock=create_socket(data_port,argv[1]);
token=strtok(NULL," \n");
if ((fp=fopen(token,"r"))!=NULL)
{
//size of file
send(sockfd,"1",MAXLINE,0);
fseek (fp , 0 , SEEK_END);
lSize = ftell (fp);
rewind (fp);
num_blks = lSize/MAXLINE;
num_last_blk = lSize%MAXLINE;
sprintf(char_num_blks,"%d",num_blks);
send(sockfd, char_num_blks, MAXLINE, 0);
//cout<<num_blks<<" "<<num_last_blk<<endl;
for(i= 0; i < num_blks; i++) {
fread (buffer,sizeof(char),MAXLINE,fp);
send(datasock, buffer, MAXLINE, 0);
//cout<<buffer<<" "<<i<<endl;
}
sprintf(char_num_last_blk,"%d",num_last_blk);
send(sockfd, char_num_last_blk, MAXLINE, 0);
if (num_last_blk > 0) {
fread (buffer,sizeof(char),num_last_blk,fp);
send(datasock, buffer, MAXLINE, 0);
//cout<<buffer<<endl;
}
fclose(fp);
cout<<"File upload done.\n";
}
else{
send(sockfd,"0",MAXLINE,0);
cerr<<"Error in opening file. Check filename\nUsage: put filename"<<endl;
}
}
else if (strcmp("get",token)==0) {
char port[MAXLINE], buffer[MAXLINE],char_num_blks[MAXLINE],char_num_last_blk[MAXLINE],message[MAXLINE];
int data_port,datasock,lSize,num_blks,num_last_blk,i;
FILE *fp;
recv(sockfd, port, MAXLINE,0);
data_port=atoi(port);
datasock=create_socket(data_port,argv[1]);
token=strtok(NULL," \n");
recv(sockfd,message,MAXLINE,0);
if(strcmp("1",message)==0){
if((fp=fopen(token,"w"))==NULL)
cout<<"Error in creating file\n";
else
{
recv(sockfd, char_num_blks, MAXLINE,0);
num_blks=atoi(char_num_blks);
for(i= 0; i < num_blks; i++) {
recv(datasock, buffer, MAXLINE,0);
fwrite(buffer,sizeof(char),MAXLINE,fp);
//cout<<buffer<<endl;
}
recv(sockfd, char_num_last_blk, MAXLINE,0);
num_last_blk=atoi(char_num_last_blk);
if (num_last_blk > 0) {
recv(datasock, buffer, MAXLINE,0);
fwrite(buffer,sizeof(char),num_last_blk,fp);
//cout<<buffer<<endl;
}
fclose(fp);
cout<<"File download done."<<endl;
}
}
else{
cerr<<"Error in opening file. Check filename\nUsage: put filename"<<endl;
}
}
else{
cerr<<"Error in command. Check Command"<<endl;
}
cout<<"ftp>";
}
exit(0);
}
int create_socket(int port,char *addr)
{
int sockfd;
struct sockaddr_in servaddr;
//Create a socket for the client
//If sockfd<0 there was an error in the creation of the socket
if ((sockfd = socket (AF_INET, SOCK_STREAM, 0)) <0) {
cerr<<"Problem in creating the socket"<<endl;
exit(2);
}
//Creation of the socket
memset(&servaddr, 0, sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_addr.s_addr= inet_addr(addr);
servaddr.sin_port = htons(port); //convert to big-endian order
//Connection of the client to the socket
if (connect(sockfd, (struct sockaddr *) &servaddr, sizeof(servaddr))<0) {
cerr<<"Problem in creating data channel"<<endl;
exit(3);
}
return(sockfd);
}
Server.c
#include <iostream>
#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>
#include <fstream>
#include <unistd.h>
using namespace std;
int create_socket(int);
int accept_conn(int);
#ifdef WINDOWS
#include <direct.h>
#define GetCurrentDir _getcwd
#else
#include <unistd.h>
#define GetCurrentDir getcwd
#endif
#define MAXLINE 4096 /*max text line length*/
#define LISTENQ 8 /*maximum number of client connections*/
int main (int argc, char **argv)
{
int listenfd, connfd, n;
pid_t childpid;
socklen_t clilen;
char buf[MAXLINE];
struct sockaddr_in cliaddr, servaddr;
if (argc !=2) { //validating the input
cerr<<"Usage: ./a.out <port number>"<<endl;
exit(1);
}
//Create a socket for the soclet
//If sockfd<0 there was an error in the creation of the socket
if ((listenfd = socket (AF_INET, SOCK_STREAM, 0)) <0) {
cerr<<"Problem in creating the socket"<<endl;
exit(2);
}
//preparation of the socket address
servaddr.sin_family = AF_INET;
servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
if(atoi(argv[1])<=1024){
cerr<<"Port number must be greater than 1024"<<endl;
exit(2);
}
servaddr.sin_port = htons(atoi(argv[1]));
//bind the socket
bind (listenfd, (struct sockaddr *) &servaddr, sizeof(servaddr));
//listen to the socket by creating a connection queue, then wait for clients
listen (listenfd, LISTENQ);
cout<<"Server running...waiting for connections."<<endl;
for ( ; ; ) {
clilen = sizeof(cliaddr);
//accept a connection
connfd = accept (listenfd, (struct sockaddr *) &cliaddr, &clilen);
cout<<"Received request..."<<endl;
if ( (childpid = fork ()) == 0 ) {//if it’s 0, it’s child process
cout<<"Child created for dealing with client requests"<<endl;
//close listening socket
close (listenfd);
int data_port=1024; //for data connection
while ( (n = recv(connfd, buf, MAXLINE,0)) > 0) {
cout<<"String received from client: "<<buf;
char *token,*dummy;
dummy=buf;
token=strtok(dummy," ");
if (strcmp("quit\n",buf)==0) {
cout<<"The client has quit\n";
}
if (strcmp("ls\n",buf)==0) {
FILE *in;
char temp[MAXLINE],port[MAXLINE];
int datasock;
data_port=data_port+1;
if(data_port==atoi(argv[1])){
data_port=data_port+1;
}
sprintf(port,"%d",data_port);
datasock=create_socket(data_port); //creating socket for data connection
send(connfd, port,MAXLINE,0); //sending data connection port no. to client
datasock=accept_conn(datasock); //accepting connection from client
if(!(in = popen("ls", "r"))){
cout<<"error"<<endl;
}
while(fgets(temp, sizeof(temp), in)!=NULL){
send(datasock,"1",MAXLINE,0);
send(datasock, temp, MAXLINE, 0);
}
send(datasock,"0",MAXLINE,0);
pclose(in);
//cout<<"file closed\n";
}
if (strcmp("pwd\n",buf)==0) {
char curr_dir[MAXLINE];
GetCurrentDir(curr_dir,MAXLINE-1);
send(connfd, curr_dir, MAXLINE, 0);
//cout<<curr_dir<<endl;
}
if (strcmp("cd",token)==0) {
token=strtok(NULL," \n");
cout<<"Path given is: "<<token<<endl;
if(chdir(token)<0){
send(connfd,"0",MAXLINE,0);
}
else{
send(connfd,"1",MAXLINE,0);
}
}
if (strcmp("put",token)==0) {
char port[MAXLINE],buffer[MAXLINE],char_num_blks[MAXLINE],char_num_last_blk[MAXLINE],check[MAXLINE];
int datasock,num_blks,num_last_blk,i;
FILE *fp;
token=strtok(NULL," \n");
cout<<"Filename given is: "<<token<<endl;
data_port=data_port+1;
if(data_port==atoi(argv[1])){
data_port=data_port+1;
}
sprintf(port,"%d",data_port);
datasock=create_socket(data_port); //creating socket for data connection
send(connfd, port,MAXLINE,0); //sending data connection port to client
datasock=accept_conn(datasock); //accepting connection
recv(connfd,check,MAXLINE,0);
cout<<check;
if(strcmp("1",check)==0){
if((fp=fopen(token,"w"))==NULL)
cout<<"Error in creating file\n";
else
{
recv(connfd, char_num_blks, MAXLINE,0);
num_blks=atoi(char_num_blks);
for(i= 0; i < num_blks; i++) {
recv(datasock, buffer, MAXLINE,0);
fwrite(buffer,sizeof(char),MAXLINE,fp);
//cout<<buffer<<endl;
}
recv(connfd, char_num_last_blk, MAXLINE,0);
num_last_blk=atoi(char_num_last_blk);
if (num_last_blk > 0) {
recv(datasock, buffer, MAXLINE,0);
fwrite(buffer,sizeof(char),num_last_blk,fp);
//cout<<buffer<<endl;
}
fclose(fp);
cout<<"File download done.\n";
}
}
}
if (strcmp("get",token)==0) {
char port[MAXLINE],buffer[MAXLINE],char_num_blks[MAXLINE],char_num_last_blk[MAXLINE];
int datasock,lSize,num_blks,num_last_blk,i;
FILE *fp;
token=strtok(NULL," \n");
cout<<"Filename given is: "<<token<<endl;
data_port=data_port+1;
if(data_port==atoi(argv[1])){
data_port=data_port+1;
}
sprintf(port,"%d",data_port);
datasock=create_socket(data_port); //creating socket for data connection
send(connfd, port,MAXLINE,0); //sending port no. to client
datasock=accept_conn(datasock); //accepting connnection by client
if ((fp=fopen(token,"r"))!=NULL)
{
//size of file
send(connfd,"1",MAXLINE,0);
fseek (fp , 0 , SEEK_END);
lSize = ftell (fp);
rewind (fp);
num_blks = lSize/MAXLINE;
num_last_blk = lSize%MAXLINE;
sprintf(char_num_blks,"%d",num_blks);
send(connfd, char_num_blks, MAXLINE, 0);
//cout<<num_blks<<" "<<num_last_blk<<endl;
for(i= 0; i < num_blks; i++) {
fread (buffer,sizeof(char),MAXLINE,fp);
send(datasock, buffer, MAXLINE, 0);
//cout<<buffer<<" "<<i<<endl;
}
sprintf(char_num_last_blk,"%d",num_last_blk);
send(connfd, char_num_last_blk, MAXLINE, 0);
if (num_last_blk > 0) {
fread (buffer,sizeof(char),num_last_blk,fp);
send(datasock, buffer, MAXLINE, 0);
//cout<<buffer<<endl;
}
fclose(fp);
cout<<"File upload done.\n";
}
else{
send(connfd,"0",MAXLINE,0);
}
}
}
if (n < 0)
cout<<"Read error"<<endl;
exit(0);
}
//close socket of the server
close(connfd);
}
}
int create_socket(int port)
{
int listenfd;
struct sockaddr_in dataservaddr;
//Create a socket for the soclet
//If sockfd<0 there was an error in the creation of the socket
if ((listenfd = socket (AF_INET, SOCK_STREAM, 0)) <0) {
cerr<<"Problem in creating the data socket"<<endl;
exit(2);
}
//preparation of the socket address
dataservaddr.sin_family = AF_INET;
dataservaddr.sin_addr.s_addr = htonl(INADDR_ANY);
dataservaddr.sin_port = htons(port);
if ((bind (listenfd, (struct sockaddr *) &dataservaddr, sizeof(dataservaddr))) <0) {
cerr<<"Problem in binding the data socket"<<endl;
exit(2);
}
//listen to the socket by creating a connection queue, then wait for clients
listen (listenfd, 1);
return(listenfd);
}
int accept_conn(int sock)
{
int dataconnfd;
socklen_t dataclilen;
struct sockaddr_in datacliaddr;
dataclilen = sizeof(datacliaddr);
//accept a connection
if ((dataconnfd = accept (sock, (struct sockaddr *) &datacliaddr, &dataclilen)) <0) {
cerr<<"Problem in accepting the data socket"<<endl;
exit(2);
}
return(dataconnfd);
}
No comments:
Post a Comment