Code:
#include <stdio.h> /* for printf() and fprintf() */
#include <sys/socket.h> /* for socket(), connect(), send(), and recv() */
#include <arpa/inet.h> /* for sockaddr_in and inet_addr() */
#include <stdlib.h> /* for atoi() */
#include <string.h> /* for memset() */
#include <unistd.h> /* for close() */
#define RCVBUFSIZE 32 /* Size of receive buffer */
#include <netdb.h>
void DieWithError(char *errorMessage); /* Error handling function */
int ftpSendFile(char * buf, char * host, int port);
int ftpRecvResponse(int sock, char * buf);
int main(int argc, char *argv[])
{
int sock; /* Socket descriptor */
int dataSock; /* Data sockeet Descriptor*/
int numberOfConn;
struct sockaddr_in ftpServAddr; /* server address */
struct sockaddr_in dataServAddr; /* data address*/
struct hostent *pt_clientAddress;
unsigned short ftpServPort; /* server port */
unsigned short dataServPort;
unsigned int PORTBUFFER;
char *servlP; /* Server IP address (dotted quad) */
char * host_name;
char *echoString; /* String to send to echo server */
char *command;
char *p;
char echoBuffer[RCVBUFSIZE]; /* Buffer for echo string */
unsigned int echoStringLen; /* Length of string to echo */
int bytesRcvd, totalBytesRcvd; /* Bytes read in single recv()
and total bytes read */
/* First arg' server IP address (dotted quad) */
/*servlP = argv[0] ;*/
servlP = "10.3.11.194";; /* Second arg' string to echo */
/*echoString = argv[2] ;*/
char buf[1024];
ftpServPort = 21;
printf(servlP);
printf("Creating Socket");
/* Create a reliable, stream socket using TCP */
if ((sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
DieWithError(" socket () failed") ;
/*Create a data socket for ftp file transfer */
if ((dataSock = socket(PF_INET, SOCK_STREAM, 0)) < 0)
DieWithError(" data socket () failed") ;
/* Construct the server address structure */
memset(&ftpServAddr, 0, sizeof(ftpServAddr)); /* Zero out structure */
ftpServAddr.sin_family = AF_INET; /* Internet address family */
ftpServAddr.sin_addr.s_addr = inet_addr(servlP); /* Server IP address */
ftpServAddr.sin_port = htons(ftpServPort); /* Server port */
/* Establish the connection to the echo server */
if (connect(sock, (struct sockaddr *) &ftpServAddr, sizeof(ftpServAddr)) < 0)
DieWithError(" connect () failed") ;
else
printf("Connection Successful");
dataServPort = 20;
/* Construct the server address structure */
memset(&dataServAddr, 0, sizeof(dataServAddr)); /* Zero out structure */
dataServAddr.sin_family = AF_INET; /* Internet address family */
dataServAddr.sin_addr.s_addr = htonl(INADDR_ANY); /* Server IP address */
dataServAddr.sin_port = htons(dataServPort); /* Server port */
/* BIND socket to (sockaddr_in) clientAddr */
bind(dataSock,(struct sockaddr *) &dataServAddr, sizeof(dataServAddr));
/* LISTEN on data_socket */
listen(dataSock, numberOfConn);
gethostname(host_name, PORTBUFFER);
printf("*******PORT********\n");
printf(host_name);
printf("\n*******\n");
/* Determine input length */
echoStringLen = strlen(echoString) ;
printf("Sending HTTP Request");
printf(echoString);
p = strcpy(command, "USER username\r\n");
send(sock, command, strlen(command), 0);
ftpRecvResponse(sock, buf);
p= strcpy(command, "PASS password\r\n");
send(sock, command, strlen(command), 0);
ftpRecvResponse(sock, buf);
p = strcpy(command,"MODE S\r\n");
send(sock,command, strlen(command), 0);
ftpRecvResponse(sock, buf);
p = strcpy(command,"TYPE A\r\n");
send(sock,command, strlen(command), 0);
ftpRecvResponse(sock, buf);
//p= strcpy(command, "STRU F\r\n");
//send(sock, command, strlen(command), 0);
//ftpRecvResponse(sock, buf);
/*p = strcpy(command,"LIST\r\n");
send(sock,command, strlen(command), 0);*/
p= strcpy(command, "PASV\r\n");
send(sock, command, strlen(command), 0);
ftpRecvResponse(sock, buf);
if (connect(dataSock, (struct sockaddr *) &dataServAddr, sizeof(dataServAddr)) < 0)
DieWithError(" connect () failed") ;
else
printf("Connection Successful");
p=strcpy(command, "RETR remote-filename\r\n");
send(sock, command, strlen(command), 0);
char *host;
int tmpPort;
host = "hostname";
tmpPort = 20;
ftpRecvResponse(sock, buf);
printf("\n"); /* Print a final linefeed */
close(sock);
exit(0);
}
int ftpSendFile(char * buf, char * host, int port) {
int sd;
struct sockaddr_in pin;
struct hostent *hp;
if ((hp = gethostbyname(host)) == 0) {
perror("gethostbyname");
return -1;
}
memset(&pin, 0, sizeof(pin));
pin.sin_family = AF_INET;
pin.sin_addr.s_addr = ((struct in_addr *)(hp->h_addr))->s_addr;
pin.sin_port = htons(port);
if ((sd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
perror("socket");
return -1;
}
if (connect(sd,(struct sockaddr *) &pin, sizeof(pin)) == -1) {
perror("connect");
return -1;
}
if(send(sd, buf, strlen(buf), 0) == -1) {
perror("send");
return -1;
}
/*closesocket(sd); //close the socket*/
return 0;
}
int ftpRecvResponse(int sock, char * buf) {
int i;
if (recv(sock, buf, 5120, 0) == -1) {//receive the data
perror("recv");
return 0;;
}
for(i=(strlen(buf) - 1);i>0;i--) {
if(buf[i]=='.' || buf[i]=='\r') {
buf[i+1]='\0';
break;
}
}
printf("%s\n",buf); //print response to the screen
return 0;
}
With this code I can connect to the ftp server with my username and pass however I am not sure how to download the file after connecting to the server, I am getting seg. fault error after successfull connection.
