tags/REL-1.1/ftpasv.c

/*

    libftp 1.0 (stable): this is an FTP library to simplify the work to a Developer
    who want to work with FTP servers (RFC 959).
    Copyright (C) 2007/2008  omnipresent - omnipresent[at]email.it

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.

*/

#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <netinet/in.h>
#include <netdb.h>
#include <fcntl.h>

#include "ftp_main.h"

/* GLOBAL VARIABLES */
/* Data Ports */
/* Port One from the PASV reply */
int data_port1;
/* Port Two from the PASV reply */
int data_port2;
/* Port for the Transfer Connection (p1 * 256) + p2 */
int data_port = 0;

#define WRONG_DATA_P    -3

/***
        ftp_pasv:
        - int sck     => Socket Descriptor
        - int verbose => Verbose?
                . 0 Do not Print
                . 1 Print
        - ret         => Success?
                . 0 Success
                .-1 Error
                .-3 Error
***/


int ftp_pasv (int sck, int verbose)
{
    char *buffer;
    int n;
    struct timeval tm; //tv_sec - tv_usec
    fd_set readfds;

    buffer = (char *)malloc(1024*sizeof(char));
    memset(buffer, 0x0, 1024);

    if (write(sck, "PASV\n", strlen("PASV\n")) == -1) {

        if (verbose) {

            if (errno == EBADF) {
                free(buffer);
                
                fprintf(stderr, "Socket Descriptor Not Valid!\n"); 
                return -1;

            } else if (errno == EIO) {
                free(buffer);
                
                fprintf(stderr, "I/O Error!\n"); 
                return -1;

            } else if (errno == EINTR) {
                free(buffer);
                
                fprintf(stderr, "Signal Interrupted The write() Function\n"); 
                return -1;
            }

        } else {

            if (errno == EBADF) {
                free(buffer);
                
                return -1;

            } else if (errno == EIO) {
                free(buffer);
                
                return -1;

            } else if (errno == EINTR) {
                free(buffer);
                
                return -1;
            }

        }

        free(buffer);
                

        return -1;

    }


    tm.tv_sec = 3;
    tm.tv_usec = 0;

    FD_ZERO(&readfds);
        
    FD_SET(sck, &readfds);

    buffer[1023] = '\0';

    if (select(sck+1, &readfds, NULL, NULL, &tm) < 0 ) {
        if (verbose) {
            perror("select()");
        }
        free(buffer);
                
        return -1;
    } else {

        if (FD_ISSET(sck, &readfds)) {

            if ( (n = recv(sck, buffer, 1022, 0)) < 0)  {
                if (verbose) {
                    perror("recv()");
                }
                free(buffer);
                
                return -1;
            }

            if (verbose) {
                printf("[Server] %s\n", buffer);
            }
        }
        else {
            if (verbose) {
                printf("[-] Timeout\n");
            }
            return -1;
        }
    }

    buffer[n] = '\0';

                
    if (find_pasv(buffer, 0) != 0) { //Error found; passive mode message not found!
        free(buffer);
        data_port = 0;
                
        return -1; //return error

    }
                
    if (verbose)
        printf("(PASV) port: %d <-> %d\n", data_port1, data_port2);
        
    memset(buffer, 0x0, 1024);

        
    data_port = ftp_DataPort(data_port1, data_port2);

    if ( (data_port == 0) || (data_port < 0) ) {
        free(buffer);
        data_port1 = 0;
        data_port2 = 0;
                
        return WRONG_DATA_P;
    }

    free(buffer);

    return 0;

}