* miscfuncs.h (class NT_readline): New class to implement line-wise

reading from file using native NT functions.
	* miscfuncs.cc (NT_readline::init): New method.
	* mount.cc (mount_info::from_fstab): Utilize NT_readline to read
	fstab files.
This commit is contained in:
Corinna Vinschen 2014-02-08 20:57:27 +00:00
parent abbe1f5320
commit 234074f683
4 changed files with 109 additions and 79 deletions

View File

@ -1,3 +1,11 @@
2014-02-08 Corinna Vinschen <corinna@vinschen.de>
* miscfuncs.h (class NT_readline): New class to implement line-wise
reading from file using native NT functions.
* miscfuncs.cc (NT_readline::init): New method.
* mount.cc (mount_info::from_fstab): Utilize NT_readline to read
fstab files.
2014-02-06 Corinna Vinschen <corinna@vinschen.de>
* fhandler_disk_file.cc (fhandler_disk_file::fchown): Fix typo in

View File

@ -1,7 +1,7 @@
/* miscfuncs.cc: misc funcs that don't belong anywhere else
Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
2007, 2008, 2009, 2010, 2011, 2012, 2013 Red Hat, Inc.
2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014 Red Hat, Inc.
This file is part of Cygwin.
@ -384,6 +384,82 @@ WritePipeOverlapped (HANDLE h, LPCVOID buf, DWORD len, LPDWORD ret_len,
return ret;
}
bool
NT_readline::init (POBJECT_ATTRIBUTES attr, PCHAR in_buf, ULONG in_buflen)
{
NTSTATUS status;
IO_STATUS_BLOCK io;
status = NtOpenFile (&fh, SYNCHRONIZE | FILE_READ_DATA, attr, &io,
FILE_SHARE_VALID_FLAGS,
FILE_SYNCHRONOUS_IO_NONALERT
| FILE_OPEN_FOR_BACKUP_INTENT);
if (!NT_SUCCESS (status))
{
paranoid_printf ("NtOpenFile(%S) failed, status %y",
&attr->ObjectName, status);
return false;
}
buf = in_buf;
buflen = in_buflen;
got = end = buf;
len = 0;
line = 1;
return true;
}
PCHAR
NT_readline::gets ()
{
IO_STATUS_BLOCK io;
while (true)
{
/* len == 0 indicates we have to read from the file. */
if (!len)
{
if (!NT_SUCCESS (NtReadFile (fh, NULL, NULL, NULL, &io, got,
(buflen - 2) - (got - buf), NULL, NULL)))
return NULL;
len = io.Information;
/* Set end marker. */
got[len] = got[len + 1] = '\0';
/* Set len to the absolute len of bytes in buf. */
len += got - buf;
/* Reset got to start reading at the start of the buffer again. */
got = end = buf;
}
else
{
got = end + 1;
++line;
}
/* Still some valid full line? */
if (got < buf + len)
{
if ((end = strchr (got, '\n')))
{
end[end[-1] == '\r' ? -1 : 0] = '\0';
return got;
}
/* Last line missing a \n at EOF? */
if (len < buflen - 2)
{
len = 0;
return got;
}
}
/* We have to read once more. Move remaining bytes to the start of
the buffer and reposition got so that it points to the end of
the remaining bytes. */
len = buf + len - got;
memmove (buf, got, len);
got = buf + len;
buf[len] = buf[len + 1] = '\0';
len = 0;
}
}
/* backslashify: Convert all forward slashes in src path to back slashes
in dst path. Add a trailing slash to dst when trailing_slash_p arg
is set to 1. */

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@ -1,7 +1,7 @@
/* miscfuncs.h: main Cygwin header file.
Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
2007, 2008, 2009, 2010, 2011, 2012, 2013 Red Hat, Inc.
2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014 Red Hat, Inc.
This file is part of Cygwin.
@ -23,6 +23,24 @@ BOOL WINAPI ReadPipeOverlapped (HANDLE h, PVOID buf, DWORD len,
BOOL WINAPI WritePipeOverlapped (HANDLE h, LPCVOID buf, DWORD len,
LPDWORD ret_len, DWORD timeout);
/* class for per-line reading using native functions. The caller provides
the file as an POBJECT_ATTRIBUTES, and the buffer space. */
class NT_readline
{
HANDLE fh;
PCHAR buf;
PCHAR got;
PCHAR end;
ULONG buflen;
ULONG len;
ULONG line;
public:
NT_readline () : fh (NULL) {}
bool init (POBJECT_ATTRIBUTES attr, char *buf, ULONG buflen);
PCHAR gets ();
~NT_readline () { if (fh) NtClose (fh); }
};
extern "C" void yield ();
#define import_address(x) __import_address ((void *)(x))

View File

@ -1177,10 +1177,9 @@ mount_info::from_fstab (bool user, WCHAR fstab[], PWCHAR fstab_end)
{
UNICODE_STRING upath;
OBJECT_ATTRIBUTES attr;
IO_STATUS_BLOCK io;
NTSTATUS status;
HANDLE fh;
NT_readline rl;
tmp_pathbuf tp;
char *buf = tp.c_get ();
if (user)
{
@ -1195,81 +1194,10 @@ mount_info::from_fstab (bool user, WCHAR fstab[], PWCHAR fstab_end)
RtlInitUnicodeString (&upath, fstab);
InitializeObjectAttributes (&attr, &upath, OBJ_CASE_INSENSITIVE, NULL, NULL);
debug_printf ("Try to read mounts from %W", fstab);
status = NtOpenFile (&fh, SYNCHRONIZE | FILE_READ_DATA, &attr, &io,
FILE_SHARE_VALID_FLAGS,
FILE_SYNCHRONOUS_IO_NONALERT
| FILE_OPEN_FOR_BACKUP_INTENT);
if (!NT_SUCCESS (status))
{
debug_printf ("NtOpenFile(%S) failed, %y", &upath, status);
return false;
}
char *buf = tp.c_get ();
char *got = buf;
DWORD len = 0;
unsigned line = 1;
/* Using buffer size - 2 leaves space to append two \0. */
while (NT_SUCCESS (NtReadFile (fh, NULL, NULL, NULL, &io, got,
(NT_MAX_PATH - 2) - (got - buf), NULL, NULL)))
{
char *end;
len = io.Information;
/* Set end marker. */
got[len] = got[len + 1] = '\0';
/* Set len to the absolute len of bytes in buf. */
len += got - buf;
/* Reset got to start reading at the start of the buffer again. */
got = buf;
retry:
bool got_nl = false;
while (got < buf + len && (end = strchr (got, '\n')))
{
got_nl = true;
end[end[-1] == '\r' ? -1 : 0] = '\0';
if (!from_fstab_line (got, user))
goto done;
got = end + 1;
++line;
}
if (len < (NT_MAX_PATH - 2))
if (rl.init (&attr, buf, NT_MAX_PATH))
while ((buf = rl.gets ()))
if (!from_fstab_line (buf, user))
break;
/* Check if the buffer contained at least one \n. If not, the
line length is > 32K. We don't take such long lines. Print
a debug message and skip this line entirely. */
if (!got_nl)
{
system_printf ("%W: Line %d too long, skipping...", fstab, line);
while (NT_SUCCESS (NtReadFile (fh, NULL, NULL, NULL, &io, buf,
(NT_MAX_PATH - 2), NULL, NULL)))
{
len = io.Information;
buf[len] = buf[len + 1] = '\0';
got = strchr (buf, '\n');
if (got)
{
++got;
++line;
goto retry;
}
}
got = buf;
break;
}
/* We have to read once more. Move remaining bytes to the start of
the buffer and reposition got so that it points to the end of
the remaining bytes. */
len = buf + len - got;
memmove (buf, got, len);
got = buf + len;
buf[len] = buf[len + 1] = '\0';
}
/* Catch a last line without trailing \n. */
if (got > buf)
from_fstab_line (got, user);
done:
NtClose (fh);
return true;
}