view/trunk/ftp_get_buffer.c

/*
  liboftp: this is an FTP library to simplify the work to a Developer
  who want to work with FTP servers (RFC 959).

  Copyright (c) 2009 hirohito higashi. All rights reserved.
  This file is distributed under BSD license.
*/


/***** Feature test switches ************************************************/
/***** System headers *******************************************************/
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>


/***** Local headers ********************************************************/
#include "liboftp.h"
#include "sub.h"


/***** Constat values *******************************************************/
#define TRANSFER_SEGMENT_SIZE   4096            /* 一度のrecv()で転送するバイト数 */


/***** Macros ***************************************************************/
/***** Typedefs *************************************************************/
/***** Function prototypes **************************************************/
/***** Local variables ******************************************************/
/***** Global variables *****************************************************/
/***** Signal catching functions ********************************************/
/***** Local functions ******************************************************/
/***** Global functions *****************************************************/

/****************************************************************************/
/*! バッファへファイル取得
 *
 *@param        ftp     LIBOFTPへのポインタ。
 *@param        fname   サーバ上のファイル名
 *@param        buf     バッファへのポインタ
 *@param        bufsiz  バッファサイズ
 *@retval       int     0: no error. -1: OS level error. -2: ftp protocol error. -3: buffer too small.
 *@note
 */
int ftp_get_buffer( LIBOFTP *ftp, const char *fname, char *buf, int bufsiz )
{
    int data_socket;
    char *p = buf;
    int n;

    /*
     * 受信準備
     */
    if( ftp->flag_passive ) {
        data_socket = ftp_getready_pasv( ftp, fname, "RETR" );
        if( data_socket < 0 ) {
            return -1;          /* XXX: mixed os level error and ftp protocol error. */
        }
    } else {
        return -2;              /* XXX: active mode not ready yet. */
    }

    /*
     * タイムアウトが意図通りに働くように、分割してrecvする。
     */
    while( 1 ) {
        int len = bufsiz;
        if( len > TRANSFER_SEGMENT_SIZE ) {
            len = TRANSFER_SEGMENT_SIZE;
        }
        n = recv( data_socket, p, len, 0 );
        DEBUGPRINT1( "RECV: n=%d\n", n );
        if( n < 0 ) {
            close( data_socket );
            return -1;
        }
        if( n == 0 ) {
            break;
        }
        p += n;
        bufsiz -= n;
        if( bufsiz <= 0 ) {
            break;
        }
    }
    close( data_socket );

    /*
     * receive response.
     */
    if( ftp_receive_response( ftp, 0, 0 ) != 226 ) {    /* 226: Closing data connection. */
        return -2;
    }

    if( bufsiz <= 0 ) {
        DEBUGPRINT1( "get_buffer: buffer too small. %s\n", "" );
        return -3;
    }
    return 0;
}