101 lines
2.3 KiB
C
101 lines
2.3 KiB
C
/*
|
|
* Copyright (c) 2000-2001 Proofpoint, Inc. and its suppliers.
|
|
* All rights reserved.
|
|
* Copyright (c) 1990, 1993
|
|
* The Regents of the University of California. All rights reserved.
|
|
*
|
|
* This code is derived from software contributed to Berkeley by
|
|
* Chris Torek.
|
|
*
|
|
* By using this file, you agree to the terms and conditions set
|
|
* forth in the LICENSE file which can be found at the top level of
|
|
* the sendmail distribution.
|
|
*/
|
|
|
|
#include <sm/gen.h>
|
|
SM_RCSID("@(#)$Id: fread.c,v 1.29 2013-11-22 20:51:42 ca Exp $")
|
|
#include <string.h>
|
|
#include <errno.h>
|
|
#include <sm/io.h>
|
|
#include <sm/assert.h>
|
|
#include "local.h"
|
|
|
|
/*
|
|
** SM_IO_READ -- read data from the file pointer
|
|
**
|
|
** Parameters:
|
|
** fp -- file pointer to read from
|
|
** timeout -- time to complete the read
|
|
** buf -- location to place read data
|
|
** size -- size of each chunk of data
|
|
**
|
|
** Returns:
|
|
** Failure: returns 0 (zero) _and_ sets errno
|
|
** Success: returns the number of whole chunks read.
|
|
**
|
|
** A read returning 0 (zero) is only an indication of error when errno
|
|
** has been set.
|
|
*/
|
|
|
|
size_t
|
|
sm_io_read(fp, timeout, buf, size)
|
|
SM_FILE_T *fp;
|
|
int timeout;
|
|
void *buf;
|
|
size_t size;
|
|
{
|
|
register size_t resid = size;
|
|
register char *p;
|
|
register int r;
|
|
|
|
SM_REQUIRE_ISA(fp, SmFileMagic);
|
|
|
|
if (fp->f_read == NULL)
|
|
{
|
|
errno = ENODEV;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
** The ANSI standard requires a return value of 0 for a count
|
|
** or a size of 0. Peculiarily, it imposes no such requirements
|
|
** on fwrite; it only requires read to be broken.
|
|
*/
|
|
|
|
if (resid == 0)
|
|
return 0;
|
|
if (fp->f_r < 0)
|
|
fp->f_r = 0;
|
|
p = buf;
|
|
while ((int) resid > (r = fp->f_r))
|
|
{
|
|
(void) memcpy((void *) p, (void *) fp->f_p, (size_t) r);
|
|
fp->f_p += r;
|
|
/* fp->f_r = 0 ... done in sm_refill */
|
|
p += r;
|
|
resid -= r;
|
|
if ((fp->f_flags & SMNOW) != 0 && r > 0)
|
|
{
|
|
/*
|
|
** Take whatever we have available. Spend no more time
|
|
** trying to get all that has been requested.
|
|
** This is needed on some file types (such as
|
|
** SASL) that would jam when given extra, untimely
|
|
** reads.
|
|
*/
|
|
|
|
fp->f_r -= r;
|
|
return size - resid;
|
|
}
|
|
if (sm_refill(fp, timeout) != 0)
|
|
{
|
|
/* no more input: return partial result */
|
|
return size - resid;
|
|
}
|
|
}
|
|
(void) memcpy((void *) p, (void *) fp->f_p, resid);
|
|
fp->f_r -= resid;
|
|
fp->f_p += resid;
|
|
return size;
|
|
}
|