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filetrans.cc
/*************************************************************************/
/* */
/* Centre for Speech Technology Research */
/* University of Edinburgh, UK */
/* Copyright (c) 1996 */
/* All Rights Reserved. */
/* */
/* Permission is hereby granted, free of charge, to use and distribute */
/* this software and its documentation without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of this work, and to */
/* permit persons to whom this work is furnished to do so, subject to */
/* the following conditions: */
/* 1. The code must retain the above copyright notice, this list of */
/* conditions and the following disclaimer. */
/* 2. Any modifications must be clearly marked as such. */
/* 3. Original authors' names are not deleted. */
/* 4. The authors' names are not used to endorse or promote products */
/* derived from this software without specific prior written */
/* permission. */
/* */
/* THE UNIVERSITY OF EDINBURGH AND THE CONTRIBUTORS TO THIS WORK */
/* DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING */
/* ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT */
/* SHALL THE UNIVERSITY OF EDINBURGH NOR THE CONTRIBUTORS BE LIABLE */
/* FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES */
/* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN */
/* AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, */
/* ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF */
/* THIS SOFTWARE. */
/* */
/*************************************************************************/
/* Author : Alan Black */
/* Date : December 1996 */
/*-----------------------------------------------------------------------*/
/* */
/* File transfer over open file descriptors. Uses key stuffing */
/* to allow transfer of any file over an open link (usually a socket) */
/* */
/*=======================================================================*/
#include "EST_unix.h"
#include <cstdio>
#include "EST_String.h"
#include "EST_io_aux.h"
// The following key is used when stuffing files down a socket.
// This key in when received denotes the end of file. Any occurrence
// of key in the file with have X inserted in it, and the receiving end
// with remove that X in the file. This is a technique I learned from
// HDLC network protocols which guarantees 0x7e (6 bits) starts a header.
// This allows transfer of files even if they include the stuff key.
const char *file_stuff_key = "ft_StUfF_key";
static int getc_unbuffered(SOCKET_FD fd)
{
// An attempted to get rid of the buffering
char c;
int n;
#ifdef WIN32
n = recv(fd,&c,1,0);
#else
n = read(fd,&c,1);
#endif
if (n == 0) // this isn't necessarily eof
return EOF;
else
return c; // and this might be -1 (EOF)
}
int socket_receive_file(SOCKET_FD fd,const EST_String &filename)
{
// Copy the file from fd to filename using the 7E stuff key
// mechanism so binary files may pass through the socket
// without signals or eof.
FILE *outfd;
int k,i,c;
if ((outfd=fopen(filename,"wb")) == NULL)
{
cerr << "socket_receive_file: can't find file \"" <<
filename << "\"\n";
return -1;
}
k=0;
while (file_stuff_key[k] != '\0')
{
c = getc_unbuffered(fd);
if (file_stuff_key[k] == c)
k++;
else if ((c == 'X') && (file_stuff_key[k+1] == '\0'))
{
for (i=0; i < k; i++) putc(file_stuff_key[i],outfd);
k=0;
// omit the stuffed 'X'
}
else
{
for (i=0; i < k; i++) putc(file_stuff_key[i],outfd);
k=0;
putc(c,outfd);
}
}
fclose(outfd);
return 0;
}
int socket_send_file(SOCKET_FD fd,const EST_String &filename)
{
// Send file down fd using the 7E end stuffing technique.
// This guarantees the binary transfer without any other
// signals eof etc
#ifndef WIN32
FILE *ffd = fdopen(dup(fd),"wb"); // use some buffering
#endif
FILE *infd;
int k,c;
if ((infd=fopen(filename,"rb")) == NULL)
{
cerr << "socket_send_file: can't find file \"" <<
filename << "\"\n";
return -1;
}
k=0;
while ((c=getc(infd)) != EOF)
{
if (file_stuff_key[k] == c)
k++;
else
k=0;
if (file_stuff_key[k] == '\0')
{
#ifdef WIN32
const char filler='X';
send(fd,&filler,1,0);
#else
putc('X',ffd); // stuff filler
#endif
k=0;
}
#ifdef WIN32
send(fd,(const char *)&c,1,0);
#else
putc(c,ffd);
#endif
}
for (k=0; file_stuff_key[k] != '\0'; k++)
#ifdef WIN32
send(fd,file_stuff_key+k,1,0);
#else
putc(file_stuff_key[k],ffd); // stuff whole key as its the end
fflush(ffd);
fclose(ffd);
#endif
fclose(infd);
return 0;
}
EST_String
Definition EST_String.h:70