OpenSolaris_b135/cmd/sendmail/libsm/fvwrite.c
/*
* Copyright (c) 2000-2001 Sendmail, 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.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <sm/gen.h>
SM_RCSID("@(#)$Id: fvwrite.c,v 1.47 2001/08/27 13:02:20 ca Exp $")
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <signal.h>
#include <fcntl.h>
#include <sm/io.h>
#include <sm/setjmp.h>
#include <sm/conf.h>
#include "local.h"
#include "fvwrite.h"
/*
** SM_FVWRITE -- write memory regions and buffer for file pointer
**
** Parameters:
** fp -- the file pointer to write to
** timeout -- time length for function to return by
** uio -- the memory regions to write
**
** Returns:
** Failure: returns SM_IO_EOF and sets errno
** Success: returns 0 (zero)
**
** This routine is large and unsightly, but most of the ugliness due
** to the different kinds of output buffering handled here.
*/
#define COPY(n) (void)memcpy((void *)fp->f_p, (void *)p, (size_t)(n))
#define GETIOV(extra_work) \
while (len == 0) \
{ \
extra_work; \
p = iov->iov_base; \
len = iov->iov_len; \
iov++; \
}
int
sm_fvwrite(fp, timeout, uio)
register SM_FILE_T *fp;
int timeout;
register struct sm_uio *uio;
{
register size_t len;
register char *p;
register struct sm_iov *iov;
register int w, s;
char *nl;
int nlknown, nldist;
int fd;
struct timeval to;
if (uio->uio_resid == 0)
return 0;
/* make sure we can write */
if (cantwrite(fp))
{
errno = EBADF;
return SM_IO_EOF;
}
SM_CONVERT_TIME(fp, fd, timeout, &to);
iov = uio->uio_iov;
p = iov->iov_base;
len = iov->iov_len;
iov++;
if (fp->f_flags & SMNBF)
{
/* Unbuffered: write up to BUFSIZ bytes at a time. */
do
{
GETIOV(;);
errno = 0; /* needed to ensure EOF correctly found */
w = (*fp->f_write)(fp, p, SM_MIN(len, SM_IO_BUFSIZ));
if (w <= 0)
{
if (w == 0 && errno == 0)
break; /* EOF found */
if (IS_IO_ERROR(fd, w, timeout))
goto err; /* errno set */
/* write would block */
SM_IO_WR_TIMEOUT(fp, fd, timeout);
w = 0;
}
else
{
p += w;
len -= w;
}
} while ((uio->uio_resid -= w) != 0);
}
else if ((fp->f_flags & SMLBF) == 0)
{
/*
** Not SMLBF (line-buffered). Either SMFBF or SMNOW
** buffered: fill partially full buffer, if any,
** and then flush. If there is no partial buffer, write
** one bf._size byte chunk directly (without copying).
**
** String output is a special case: write as many bytes
** as fit, but pretend we wrote everything. This makes
** snprintf() return the number of bytes needed, rather
** than the number used, and avoids its write function
** (so that the write function can be invalid).
*/
do
{
GETIOV(;);
if ((((fp->f_flags & (SMALC | SMSTR)) == (SMALC | SMSTR))
|| ((fp->f_flags & SMNOW) != 0))
&& (size_t) fp->f_w < len)
{
size_t blen = fp->f_p - fp->f_bf.smb_base;
unsigned char *tbase;
int tsize;
/* Allocate space exponentially. */
tsize = fp->f_bf.smb_size;
do
{
tsize = (tsize << 1) + 1;
} while ((size_t) tsize < blen + len);
tbase = (unsigned char *) sm_realloc(fp->f_bf.smb_base,
tsize + 1);
if (tbase == NULL)
{
errno = ENOMEM;
goto err; /* errno set */
}
fp->f_w += tsize - fp->f_bf.smb_size;
fp->f_bf.smb_base = tbase;
fp->f_bf.smb_size = tsize;
fp->f_p = tbase + blen;
}
w = fp->f_w;
errno = 0; /* needed to ensure EOF correctly found */
if (fp->f_flags & SMSTR)
{
if (len < (size_t) w)
w = len;
COPY(w); /* copy SM_MIN(fp->f_w,len), */
fp->f_w -= w;
fp->f_p += w;
w = len; /* but pretend copied all */
}
else if (fp->f_p > fp->f_bf.smb_base
&& len > (size_t) w)
{
/* fill and flush */
COPY(w);
fp->f_p += w;
if (sm_flush(fp, &timeout))
goto err; /* errno set */
}
else if (len >= (size_t) (w = fp->f_bf.smb_size))
{
/* write directly */
w = (*fp->f_write)(fp, p, w);
if (w <= 0)
{
if (w == 0 && errno == 0)
break; /* EOF found */
if (IS_IO_ERROR(fd, w, timeout))
goto err; /* errno set */
/* write would block */
SM_IO_WR_TIMEOUT(fp, fd, timeout);
w = 0;
}
}
else
{
/* fill and done */
w = len;
COPY(w);
fp->f_w -= w;
fp->f_p += w;
}
p += w;
len -= w;
} while ((uio->uio_resid -= w) != 0);
if ((fp->f_flags & SMNOW) != 0 && sm_flush(fp, &timeout))
goto err; /* errno set */
}
else
{
/*
** Line buffered: like fully buffered, but we
** must check for newlines. Compute the distance
** to the first newline (including the newline),
** or `infinity' if there is none, then pretend
** that the amount to write is SM_MIN(len,nldist).
*/
nlknown = 0;
nldist = 0; /* XXX just to keep gcc happy */
do
{
GETIOV(nlknown = 0);
if (!nlknown)
{
nl = memchr((void *)p, '\n', len);
nldist = nl != NULL ? nl + 1 - p : len + 1;
nlknown = 1;
}
s = SM_MIN(len, ((size_t) nldist));
w = fp->f_w + fp->f_bf.smb_size;
errno = 0; /* needed to ensure EOF correctly found */
if (fp->f_p > fp->f_bf.smb_base && s > w)
{
COPY(w);
/* fp->f_w -= w; */
fp->f_p += w;
if (sm_flush(fp, &timeout))
goto err; /* errno set */
}
else if (s >= (w = fp->f_bf.smb_size))
{
w = (*fp->f_write)(fp, p, w);
if (w <= 0)
{
if (w == 0 && errno == 0)
break; /* EOF found */
if (IS_IO_ERROR(fd, w, timeout))
goto err; /* errno set */
/* write would block */
SM_IO_WR_TIMEOUT(fp, fd, timeout);
w = 0;
}
}
else
{
w = s;
COPY(w);
fp->f_w -= w;
fp->f_p += w;
}
if ((nldist -= w) == 0)
{
/* copied the newline: flush and forget */
if (sm_flush(fp, &timeout))
goto err; /* errno set */
nlknown = 0;
}
p += w;
len -= w;
} while ((uio->uio_resid -= w) != 0);
}
return 0;
err:
/* errno set before goto places us here */
fp->f_flags |= SMERR;
return SM_IO_EOF;
}