[newlib-cygwin] Cygwin: pipe: Revert to create() rather than nt_create().
Corinna Vinschen
corinna@sourceware.org
Tue Sep 14 15:05:14 GMT 2021
https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=cf3a7a9132fbc3eae466709c63b68f29f4b91ddc
commit cf3a7a9132fbc3eae466709c63b68f29f4b91ddc
Author: Takashi Yano <takashi.yano@nifty.ne.jp>
Date: Sun Aug 29 17:23:57 2021 +0900
Cygwin: pipe: Revert to create() rather than nt_create().
Diff:
---
winsup/cygwin/fhandler_pipe.cc | 192 +++++------------------------------------
1 file changed, 21 insertions(+), 171 deletions(-)
diff --git a/winsup/cygwin/fhandler_pipe.cc b/winsup/cygwin/fhandler_pipe.cc
index 2dec0a848..a6ece17a6 100644
--- a/winsup/cygwin/fhandler_pipe.cc
+++ b/winsup/cygwin/fhandler_pipe.cc
@@ -463,13 +463,13 @@ fhandler_pipe::create (LPSECURITY_ATTRIBUTES sa_ptr, PHANDLE r, PHANDLE w,
if (name)
len += __small_sprintf (pipename + len, "%s", name);
- open_mode |= PIPE_ACCESS_INBOUND | FILE_FLAG_FIRST_PIPE_INSTANCE;
+ open_mode |= PIPE_ACCESS_OUTBOUND | FILE_FLAG_FIRST_PIPE_INSTANCE;
/* Retry CreateNamedPipe as long as the pipe name is in use.
Retrying will probably never be necessary, but we want
to be as robust as possible. */
DWORD err = 0;
- while (r && !*r)
+ while (w && !*w)
{
static volatile ULONG pipe_unique_id;
if (!name)
@@ -498,12 +498,12 @@ fhandler_pipe::create (LPSECURITY_ATTRIBUTES sa_ptr, PHANDLE r, PHANDLE w,
definitely required for pty handling since fhandler_pty_master
writes to the pipe in chunks, terminated by newline when CANON mode
is specified. */
- *r = CreateNamedPipe (pipename, open_mode, pipe_mode, 1, psize,
+ *w = CreateNamedPipe (pipename, open_mode, pipe_mode, 1, psize,
psize, NMPWAIT_USE_DEFAULT_WAIT, sa_ptr);
- if (*r != INVALID_HANDLE_VALUE)
+ if (*w != INVALID_HANDLE_VALUE)
{
- debug_printf ("pipe read handle %p", *r);
+ debug_printf ("pipe write handle %p", *w);
err = 0;
break;
}
@@ -516,14 +516,14 @@ fhandler_pipe::create (LPSECURITY_ATTRIBUTES sa_ptr, PHANDLE r, PHANDLE w,
Pick a new name and retry. */
debug_printf ("pipe busy", !name ? ", retrying" : "");
if (!name)
- *r = NULL;
+ *w = NULL;
break;
case ERROR_ACCESS_DENIED:
/* The pipe is already open with incompatible parameters.
Pick a new name and retry. */
debug_printf ("pipe access denied%s", !name ? ", retrying" : "");
if (!name)
- *r = NULL;
+ *w = NULL;
break;
default:
{
@@ -535,60 +535,42 @@ fhandler_pipe::create (LPSECURITY_ATTRIBUTES sa_ptr, PHANDLE r, PHANDLE w,
if (err)
{
- *r = NULL;
+ *w = NULL;
return err;
}
- if (!w)
- debug_printf ("pipe write handle NULL");
+ if (!r)
+ debug_printf ("pipe read handle NULL");
else
{
debug_printf ("CreateFile: name %s", pipename);
- /* Open the named pipe for writing.
- Be sure to permit FILE_READ_ATTRIBUTES access. */
- DWORD access = GENERIC_WRITE | FILE_READ_ATTRIBUTES;
+ /* Open the named pipe for reading.
+ Be sure to permit FILE_WRITE_ATTRIBUTES access. */
+ DWORD access = GENERIC_READ | FILE_WRITE_ATTRIBUTES;
if ((open_mode & PIPE_ACCESS_DUPLEX) == PIPE_ACCESS_DUPLEX)
- access |= GENERIC_READ | FILE_WRITE_ATTRIBUTES;
- *w = CreateFile (pipename, access, 0, sa_ptr, OPEN_EXISTING,
+ access |= GENERIC_WRITE | FILE_READ_ATTRIBUTES;
+ *r = CreateFile (pipename, access, 0, sa_ptr, OPEN_EXISTING,
open_mode & FILE_FLAG_OVERLAPPED, 0);
- if (!*w || *w == INVALID_HANDLE_VALUE)
+ if (!*r || *r == INVALID_HANDLE_VALUE)
{
/* Failure. */
DWORD err = GetLastError ();
debug_printf ("CreateFile failed, r %p, %E", r);
- if (r)
- CloseHandle (*r);
- *w = NULL;
+ if (w)
+ CloseHandle (*w);
+ *r = NULL;
return err;
}
- debug_printf ("pipe write handle %p", *w);
+ debug_printf ("pipe read handle %p", *r);
}
/* Success. */
return 0;
}
-/* The next version of fhandler_pipe::create used to call the previous
- version. But the read handle created by the latter doesn't have
- FILE_WRITE_ATTRIBUTES access unless the pipe is created with
- PIPE_ACCESS_DUPLEX, and it doesn't seem possible to add that access
- right. This causes set_pipe_non_blocking to fail.
-
- To fix this we will define a helper function 'nt_create' that is
- similar to the above fhandler_pipe::create but uses
- NtCreateNamedPipeFile instead of CreateNamedPipe; this gives more
- flexibility in setting the access rights. We will use this helper
- function in the version of fhandler_pipe::create below, which
- suffices for all of our uses of set_pipe_non_blocking. For
- simplicity, nt_create will omit the 'open_mode' and 'name'
- parameters, which aren't needed for our purposes. */
-
-static int nt_create (LPSECURITY_ATTRIBUTES, PHANDLE, PHANDLE, DWORD,
- int64_t *);
-
int
fhandler_pipe::create (fhandler_pipe *fhs[2], unsigned psize, int mode)
{
@@ -597,7 +579,7 @@ fhandler_pipe::create (fhandler_pipe *fhs[2], unsigned psize, int mode)
int res = -1;
int64_t unique_id;
- int ret = nt_create (sa, &r, &w, psize, &unique_id);
+ int ret = create (sa, &r, &w, psize, NULL, 0, &unique_id);
if (ret)
__seterrno_from_win_error (ret);
else if ((fhs[0] = (fhandler_pipe *) build_fh_dev (*piper_dev)) == NULL)
@@ -624,138 +606,6 @@ fhandler_pipe::create (fhandler_pipe *fhs[2], unsigned psize, int mode)
return res;
}
-static int
-nt_create (LPSECURITY_ATTRIBUTES sa_ptr, PHANDLE r, PHANDLE w,
- DWORD psize, int64_t *unique_id)
-{
- NTSTATUS status;
- HANDLE npfsh;
- ACCESS_MASK access;
- OBJECT_ATTRIBUTES attr;
- IO_STATUS_BLOCK io;
- LARGE_INTEGER timeout;
-
- /* Default to error. */
- if (r)
- *r = NULL;
- if (w)
- *w = NULL;
-
- status = fhandler_base::npfs_handle (npfsh);
- if (!NT_SUCCESS (status))
- {
- __seterrno_from_nt_status (status);
- return GetLastError ();
- }
-
- /* Ensure that there is enough pipe buffer space for atomic writes. */
- if (!psize)
- psize = DEFAULT_PIPEBUFSIZE;
-
- UNICODE_STRING pipename;
- WCHAR pipename_buf[MAX_PATH];
- size_t len = __small_swprintf (pipename_buf, L"%S-%u-",
- &cygheap->installation_key,
- GetCurrentProcessId ());
-
- access = GENERIC_READ | FILE_WRITE_ATTRIBUTES;
-
- ULONG pipe_type = pipe_byte ? FILE_PIPE_BYTE_STREAM_TYPE
- : FILE_PIPE_MESSAGE_TYPE;
-
- /* Retry NtCreateNamedPipeFile as long as the pipe name is in use.
- Retrying will probably never be necessary, but we want
- to be as robust as possible. */
- DWORD err = 0;
- while (r && !*r)
- {
- static volatile ULONG pipe_unique_id;
- LONG id = InterlockedIncrement ((LONG *) &pipe_unique_id);
- __small_swprintf (pipename_buf + len, L"pipe-nt-%p", id);
- if (unique_id)
- *unique_id = ((int64_t) id << 32 | GetCurrentProcessId ());
-
- debug_printf ("name %W, size %u, mode %s", pipename_buf, psize,
- (pipe_type & FILE_PIPE_MESSAGE_TYPE)
- ? "PIPE_TYPE_MESSAGE" : "PIPE_TYPE_BYTE");
-
- RtlInitUnicodeString (&pipename, pipename_buf);
-
- InitializeObjectAttributes (&attr, &pipename,
- sa_ptr->bInheritHandle ? OBJ_INHERIT : 0,
- npfsh, sa_ptr->lpSecurityDescriptor);
-
- timeout.QuadPart = -500000;
- status = NtCreateNamedPipeFile (r, access, &attr, &io,
- FILE_SHARE_READ | FILE_SHARE_WRITE,
- FILE_CREATE, 0, pipe_type,
- FILE_PIPE_BYTE_STREAM_MODE,
- 0, 1, psize, psize, &timeout);
-
- if (NT_SUCCESS (status))
- {
- debug_printf ("pipe read handle %p", *r);
- err = 0;
- break;
- }
-
- switch (status)
- {
- case STATUS_PIPE_BUSY:
- case STATUS_INSTANCE_NOT_AVAILABLE:
- case STATUS_PIPE_NOT_AVAILABLE:
- /* The pipe is already open with compatible parameters.
- Pick a new name and retry. */
- debug_printf ("pipe busy, retrying");
- *r = NULL;
- break;
- case STATUS_ACCESS_DENIED:
- /* The pipe is already open with incompatible parameters.
- Pick a new name and retry. */
- debug_printf ("pipe access denied, retrying");
- *r = NULL;
- break;
- default:
- {
- __seterrno_from_nt_status (status);
- err = GetLastError ();
- debug_printf ("failed, %E");
- *r = INVALID_HANDLE_VALUE;
- }
- }
- }
-
- if (err)
- {
- *r = NULL;
- return err;
- }
-
- if (!w)
- debug_printf ("pipe write handle NULL");
- else
- {
- debug_printf ("NtOpenFile: name %S", &pipename);
-
- access = GENERIC_WRITE | FILE_READ_ATTRIBUTES;
- status = NtOpenFile (w, access, &attr, &io, 0, 0);
- if (!NT_SUCCESS (status))
- {
- DWORD err = GetLastError ();
- debug_printf ("NtOpenFile failed, r %p, %E", r);
- if (r)
- CloseHandle (*r);
- *w = NULL;
- return err;
- }
-
- debug_printf ("pipe write handle %p", *w);
- }
-
- /* Success. */
- return 0;
-}
-
int
fhandler_pipe::ioctl (unsigned int cmd, void *p)
{
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