newlib-cygwin/winsup/cygwin/fhandler_raw.cc

564 lines
12 KiB
C++

/* fhandler_raw.cc. See fhandler.h for a description of the fhandler classes.
Copyright 1999, 2000, 2001, 2002 Red Hat, Inc.
This file is part of Cygwin.
This software is a copyrighted work licensed under the terms of the
Cygwin license. Please consult the file "CYGWIN_LICENSE" for
details. */
#include "winsup.h"
#include <sys/termios.h>
#include <errno.h>
#include <unistd.h>
#include <cygwin/rdevio.h>
#include <sys/mtio.h>
#include <ntdef.h>
#include "cygerrno.h"
#include "perprocess.h"
#include "security.h"
#include "fhandler.h"
#include "path.h"
#include "dtable.h"
#include "cygheap.h"
#include "ntdll.h"
/* static wrapper functions to hide the effect of media changes and
bus resets which occurs after a new media is inserted. This is
also related to the used tape device. */
static BOOL write_file (HANDLE fh, const void *buf, DWORD to_write,
DWORD *written, int *err)
{
BOOL ret;
*err = 0;
if (!(ret = WriteFile (fh, buf, to_write, written, 0)))
{
if ((*err = GetLastError ()) == ERROR_MEDIA_CHANGED
|| *err == ERROR_BUS_RESET)
{
*err = 0;
if (!(ret = WriteFile (fh, buf, to_write, written, 0)))
*err = GetLastError ();
}
}
syscall_printf ("%d (err %d) = WriteFile (%d, %d, write %d, written %d, 0)",
ret, *err, fh, buf, to_write, *written);
return ret;
}
static BOOL read_file (HANDLE fh, void *buf, DWORD to_read,
DWORD *read, int *err)
{
BOOL ret;
*err = 0;
if (!(ret = ReadFile (fh, buf, to_read, read, 0)))
{
if ((*err = GetLastError ()) == ERROR_MEDIA_CHANGED
|| *err == ERROR_BUS_RESET)
{
*err = 0;
if (!(ret = ReadFile (fh, buf, to_read, read, 0)))
*err = GetLastError ();
}
}
syscall_printf ("%d (err %d) = ReadFile (%d, %d, to_read %d, read %d, 0)",
ret, *err, fh, buf, to_read, *read);
return ret;
}
/**********************************************************************/
/* fhandler_dev_raw */
void
fhandler_dev_raw::clear (void)
{
devbuf = NULL;
devbufsiz = 0;
devbufstart = 0;
devbufend = 0;
eom_detected = 0;
eof_detected = 0;
lastblk_to_read = 0;
varblkop = 0;
}
int
fhandler_dev_raw::writebuf (void)
{
DWORD written;
int ret = 0;
if (is_writing && devbuf && devbufend)
{
DWORD to_write;
int ret = 0;
memset (devbuf + devbufend, 0, devbufsiz - devbufend);
if (get_device () != FH_TAPE)
to_write = ((devbufend - 1) / 512 + 1) * 512;
else if (varblkop)
to_write = devbufend;
else
to_write = devbufsiz;
if (!write_file (get_handle (), devbuf, to_write, &written, &ret)
&& is_eom (ret))
eom_detected = 1;
if (written)
has_written = 1;
devbufstart = devbufend = 0;
}
is_writing = 0;
return ret;
}
fhandler_dev_raw::fhandler_dev_raw (DWORD devtype, int nunit)
: fhandler_base (devtype), unit (nunit)
{
clear ();
set_need_fork_fixup ();
}
fhandler_dev_raw::~fhandler_dev_raw (void)
{
if (devbufsiz > 1L)
delete [] devbuf;
clear ();
}
int
fhandler_dev_raw::open (path_conv *real_path, int flags, mode_t)
{
if (!wincap.has_raw_devices ())
{
set_errno (ENOENT);
debug_printf ("%s is accessible under NT/W2K only",real_path->get_win32());
return 0;
}
/* Check for illegal flags. */
if (flags & (O_APPEND | O_EXCL))
{
set_errno (EINVAL);
return 0;
}
/* Always open a raw device existing and binary. */
flags &= ~(O_CREAT | O_TRUNC);
flags |= O_BINARY;
DWORD access = GENERIC_READ | SYNCHRONIZE;
if (get_device () == FH_TAPE
|| (flags & (O_RDONLY | O_WRONLY | O_RDWR)) == O_WRONLY
|| (flags & (O_RDONLY | O_WRONLY | O_RDWR)) == O_RDWR)
access |= GENERIC_WRITE;
extern void str2buf2uni (UNICODE_STRING &, WCHAR *, const char *);
UNICODE_STRING dev;
WCHAR devname[MAX_PATH + 1];
str2buf2uni (dev, devname, real_path->get_win32 ());
OBJECT_ATTRIBUTES attr;
InitializeObjectAttributes (&attr, &dev, OBJ_CASE_INSENSITIVE, NULL, NULL);
HANDLE h;
IO_STATUS_BLOCK io;
NTSTATUS status = NtOpenFile (&h, access, &attr, &io, wincap.shared (),
FILE_SYNCHRONOUS_IO_NONALERT);
if (!NT_SUCCESS (status))
{
__seterrno_from_win_error (RtlNtStatusToDosError (status));
return 0;
}
set_io_handle (h);
set_flags ((flags & ~O_TEXT) | O_BINARY);
if (devbufsiz > 1L)
devbuf = new char [devbufsiz];
return 1;
}
int
fhandler_dev_raw::close (void)
{
return fhandler_base::close ();
}
int
fhandler_dev_raw::raw_read (void *ptr, size_t ulen)
{
DWORD bytes_read = 0;
DWORD read2;
DWORD bytes_to_read;
int ret;
size_t len = ulen;
char *tgt;
/* In mode O_RDWR the buffer has to be written to device first */
ret = writebuf ();
if (ret)
{
set_errno (is_eom (ret) ? ENOSPC : EACCES);
return -1;
}
/* Checking a previous end of file */
if (eof_detected && !lastblk_to_read)
{
eof_detected = 0;
return 0;
}
/* Checking a previous end of media */
if (eom_detected && !lastblk_to_read)
{
set_errno (ENOSPC);
return -1;
}
if (devbuf)
{
while (len > 0)
{
if (devbufstart < devbufend)
{
bytes_to_read = min (len, devbufend - devbufstart);
debug_printf ("read %d bytes from buffer (rest %d)",
bytes_to_read, devbufstart - devbufend);
memcpy (ptr, devbuf + devbufstart, bytes_to_read);
len -= bytes_to_read;
ptr = (void *) ((char *) ptr + bytes_to_read);
bytes_read += bytes_to_read;
devbufstart += bytes_to_read;
if (lastblk_to_read)
{
lastblk_to_read = 0;
break;
}
}
if (len > 0)
{
if (!varblkop && len >= devbufsiz)
{
if (get_device () == FH_TAPE)
bytes_to_read = (len / devbufsiz) * devbufsiz;
else
bytes_to_read = (len / 512) * 512;
tgt = (char *) ptr;
debug_printf ("read %d bytes direct from file",bytes_to_read);
}
else
{
bytes_to_read = devbufsiz;
tgt = devbuf;
if (varblkop)
debug_printf ("read variable bytes from file into buffer");
else
debug_printf ("read %d bytes from file into buffer",
bytes_to_read);
}
if (!read_file (get_handle (), tgt, bytes_to_read, &read2, &ret))
{
if (!is_eof (ret) && !is_eom (ret))
{
debug_printf ("return -1, set errno to EACCES");
set_errno (EACCES);
return -1;
}
if (is_eof (ret))
eof_detected = 1;
else
eom_detected = 1;
if (!read2)
{
if (!bytes_read && is_eom (ret))
{
debug_printf ("return -1, set errno to ENOSPC");
set_errno (ENOSPC);
return -1;
}
break;
}
lastblk_to_read = 1;
}
if (! read2)
break;
if (tgt == devbuf)
{
devbufstart = 0;
devbufend = read2;
}
else
{
len -= bytes_to_read;
ptr = (void *) ((char *) ptr + bytes_to_read);
bytes_read += bytes_to_read;
}
}
}
}
else if (!read_file (get_handle (), ptr, len, &bytes_read, &ret))
{
if (!is_eof (ret) && !is_eom (ret))
{
debug_printf ("return -1, set errno to EACCES");
set_errno (EACCES);
return -1;
}
if (bytes_read)
{
if (is_eof (ret))
eof_detected = 1;
else
eom_detected = 1;
}
else if (is_eom (ret))
{
debug_printf ("return -1, set errno to ENOSPC");
set_errno (ENOSPC);
return -1;
}
}
return bytes_read;
}
int
fhandler_dev_raw::raw_write (const void *ptr, size_t len)
{
DWORD bytes_written = 0;
DWORD bytes_to_write;
DWORD written;
char *p = (char *) ptr;
char *tgt;
int ret;
/* Checking a previous end of media on tape */
if (eom_detected)
{
set_errno (ENOSPC);
return -1;
}
if (!is_writing)
{
devbufend = devbufstart;
devbufstart = 0;
}
is_writing = 1;
if (devbuf)
{
while (len > 0)
{
if (!varblkop &&
(len < devbufsiz || devbufend > 0) && devbufend < devbufsiz)
{
bytes_to_write = min (len, devbufsiz - devbufend);
memcpy (devbuf + devbufend, p, bytes_to_write);
bytes_written += bytes_to_write;
devbufend += bytes_to_write;
p += bytes_to_write;
len -= bytes_to_write;
}
else
{
if (varblkop)
{
bytes_to_write = len;
tgt = p;
}
else if (devbufend == devbufsiz)
{
bytes_to_write = devbufsiz;
tgt = devbuf;
}
else
{
bytes_to_write = (len / devbufsiz) * devbufsiz;
tgt = p;
}
ret = 0;
write_file (get_handle (), tgt, bytes_to_write, &written, &ret);
if (written)
has_written = 1;
if (ret)
{
if (!is_eom (ret))
{
__seterrno ();
return -1;
}
eom_detected = 1;
if (!written && !bytes_written)
{
set_errno (ENOSPC);
return -1;
}
if (tgt == p)
bytes_written += written;
break; // from while (len > 0)
}
if (tgt == devbuf)
{
if (written != devbufsiz)
memmove (devbuf, devbuf + written, devbufsiz - written);
devbufend = devbufsiz - written;
}
else
{
len -= written;
p += written;
bytes_written += written;
}
}
}
}
else if (len > 0)
{
if (!write_file (get_handle (), ptr, len, &bytes_written, &ret))
{
if (bytes_written)
has_written = 1;
if (!is_eom (ret))
{
set_errno (EACCES);
return -1;
}
eom_detected = 1;
if (!bytes_written)
{
set_errno (ENOSPC);
return -1;
}
}
has_written = 1;
}
return bytes_written;
}
int
fhandler_dev_raw::dup (fhandler_base *child)
{
int ret = fhandler_base::dup (child);
if (! ret)
{
fhandler_dev_raw *fhc = (fhandler_dev_raw *) child;
fhc->devbufsiz = devbufsiz;
if (devbufsiz > 1L)
fhc->devbuf = new char [devbufsiz];
fhc->devbufstart = 0;
fhc->devbufend = 0;
fhc->eom_detected = eom_detected;
fhc->eof_detected = eof_detected;
fhc->lastblk_to_read = 0;
fhc->varblkop = varblkop;
fhc->unit = unit;
}
return ret;
}
void
fhandler_dev_raw::fixup_after_fork (HANDLE)
{
devbufstart = 0;
devbufend = 0;
lastblk_to_read = 0;
}
void
fhandler_dev_raw::fixup_after_exec (HANDLE)
{
if (devbufsiz > 1L)
devbuf = new char [devbufsiz];
devbufstart = 0;
devbufend = 0;
lastblk_to_read = 0;
}
int
fhandler_dev_raw::ioctl (unsigned int cmd, void *buf)
{
int ret = NO_ERROR;
if (cmd == RDIOCDOP)
{
struct rdop *op = (struct rdop *) buf;
if (!op)
ret = ERROR_INVALID_PARAMETER;
else
switch (op->rd_op)
{
case RDSETBLK:
if (get_device () == FH_TAPE)
{
struct mtop mop;
mop.mt_op = MTSETBLK;
mop.mt_count = op->rd_parm;
ret = ioctl (MTIOCTOP, &mop);
}
else if (op->rd_parm % 512)
ret = ERROR_INVALID_PARAMETER;
else if (devbuf && op->rd_parm < devbufend - devbufstart)
ret = ERROR_INVALID_PARAMETER;
else if (!devbuf || op->rd_parm != devbufsiz)
{
char *buf = new char [op->rd_parm];
if (devbufsiz > 1L)
{
memcpy (buf, devbuf + devbufstart, devbufend - devbufstart);
devbufend -= devbufstart;
delete [] devbuf;
}
else
devbufend = 0;
devbufstart = 0;
devbuf = buf;
devbufsiz = op->rd_parm;
}
break;
default:
break;
}
}
else if (cmd == RDIOCGET)
{
struct rdget *get = (struct rdget *) buf;
if (!get)
ret = ERROR_INVALID_PARAMETER;
else
get->bufsiz = devbufsiz ? devbufsiz : 1L;
}
else
return fhandler_base::ioctl (cmd, buf);
if (ret != NO_ERROR)
{
SetLastError (ret);
__seterrno ();
return -1;
}
return 0;
}