diff options
Diffstat (limited to 'winsup/cygwin/fhandler_floppy.cc')
| -rw-r--r-- | winsup/cygwin/fhandler_floppy.cc | 79 |
1 files changed, 76 insertions, 3 deletions
diff --git a/winsup/cygwin/fhandler_floppy.cc b/winsup/cygwin/fhandler_floppy.cc index ec48c91f3..a767443b9 100644 --- a/winsup/cygwin/fhandler_floppy.cc +++ b/winsup/cygwin/fhandler_floppy.cc @@ -15,6 +15,7 @@ details. */ #include <errno.h> #include <unistd.h> #include "fhandler.h" +#include "cygerrno.h" /**********************************************************************/ /* fhandler_dev_floppy */ @@ -78,9 +79,81 @@ fhandler_dev_floppy::close (void) off_t fhandler_dev_floppy::lseek (off_t offset, int whence) { - /* FIXME: Need to implement better. */ - offset = (offset / 512) * 512; - return fhandler_base::lseek (offset, whence); + int ret; + DWORD off; + char buf[512]; + + if (whence == SEEK_SET) + { + if (offset < 0) + { + set_errno (EINVAL); + return -1; + } + + /* Invalidate buffer. */ + ret = writebuf (); + if (ret) + return ret; + devbufstart = devbufend = 0; + + off = (offset / 512) * 512; + + if (SetFilePointer (get_handle (), off, NULL, FILE_BEGIN) + == INVALID_SET_FILE_POINTER) + { + __seterrno (); + return -1; + } + return raw_read (buf, offset - off); + } + else if (whence == SEEK_CUR) + { + DWORD low; + LONG high = 0; + + low = SetFilePointer (get_handle (), 0, &high, FILE_CURRENT); + if (low == INVALID_SET_FILE_POINTER && GetLastError ()) + { + __seterrno (); + return -1; + } + long long cur = (long long) high << 32 + low; + if (is_writing) + cur += devbufend - devbufstart; + else + cur -= devbufend - devbufstart; + + /* Invalidate buffer. */ + ret = writebuf (); + if (ret) + return ret; + devbufstart = devbufend = 0; + + cur += offset; + if (cur < 0) + { + set_errno (EINVAL); + return -1; + } + + long long set = (cur / 512) * 512; + high = set >> 32; + low = set & 0xffffffff; + + off = cur - set; + + low = SetFilePointer (get_handle (), low, &high, FILE_BEGIN); + if (low == INVALID_SET_FILE_POINTER && GetLastError ()) + { + __seterrno (); + return -1; + } + return raw_read (buf, off); + } + /* SEEK_END is not supported on raw disk devices. */ + set_errno (EINVAL); + return -1; } int |