504 lines
12 KiB
C++
504 lines
12 KiB
C++
/* pipe.cc: pipe for Cygwin.
|
|
|
|
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. */
|
|
|
|
/* FIXME: Should this really be fhandler_pipe.cc? */
|
|
|
|
#include "winsup.h"
|
|
#include <stdlib.h>
|
|
#include <sys/socket.h>
|
|
#include "cygerrno.h"
|
|
#include "security.h"
|
|
#include "path.h"
|
|
#include "fhandler.h"
|
|
#include "dtable.h"
|
|
#include "cygheap.h"
|
|
#include "pinfo.h"
|
|
#include "shared_info.h"
|
|
|
|
fhandler_pipe::fhandler_pipe ()
|
|
: fhandler_base_overlapped (), popen_pid (0)
|
|
{
|
|
max_atomic_write = DEFAULT_PIPEBUFSIZE;
|
|
need_fork_fixup (true);
|
|
}
|
|
|
|
int
|
|
fhandler_pipe::init (HANDLE f, DWORD a, mode_t mode, int64_t uniq_id)
|
|
{
|
|
/* FIXME: Have to clean this up someday
|
|
FIXME: Do we have to check for both !get_win32_name() and
|
|
!*get_win32_name()? */
|
|
if ((!get_win32_name () || !*get_win32_name ()) && get_name ())
|
|
{
|
|
char *d;
|
|
const char *s;
|
|
char *hold_normalized_name = (char *) alloca (strlen (get_name ()) + 1);
|
|
for (s = get_name (), d = hold_normalized_name; *s; s++, d++)
|
|
if (*s == '/')
|
|
*d = '\\';
|
|
else
|
|
*d = *s;
|
|
*d = '\0';
|
|
set_name (hold_normalized_name);
|
|
}
|
|
|
|
bool opened_properly = a & FILE_CREATE_PIPE_INSTANCE;
|
|
a &= ~FILE_CREATE_PIPE_INSTANCE;
|
|
fhandler_base::init (f, a, mode);
|
|
close_on_exec (mode & O_CLOEXEC);
|
|
set_ino (uniq_id);
|
|
set_unique_id (uniq_id | !!(mode & GENERIC_WRITE));
|
|
if (opened_properly)
|
|
setup_overlapped ();
|
|
else
|
|
destroy_overlapped ();
|
|
return 1;
|
|
}
|
|
|
|
extern "C" int sscanf (const char *, const char *, ...);
|
|
|
|
int
|
|
fhandler_pipe::open (int flags, mode_t mode)
|
|
{
|
|
HANDLE proc, nio_hdl = NULL;
|
|
int64_t uniq_id;
|
|
fhandler_pipe *fh = NULL, *fhr = NULL, *fhw = NULL;
|
|
size_t size;
|
|
int pid, rwflags = (flags & O_ACCMODE);
|
|
bool inh;
|
|
bool got_one = false;
|
|
|
|
sscanf (get_name (), "/proc/%d/fd/pipe:[%lld]",
|
|
&pid, (long long *) &uniq_id);
|
|
if (pid == myself->pid)
|
|
{
|
|
cygheap_fdenum cfd (true);
|
|
while (cfd.next () >= 0)
|
|
{
|
|
/* Windows doesn't allow to copy a pipe HANDLE with another access
|
|
mode. So we check for read and write side of pipe and try to
|
|
find the one matching the requested access mode. */
|
|
if (cfd->get_unique_id () == uniq_id)
|
|
got_one = true;
|
|
else if (cfd->get_unique_id () == uniq_id + 1)
|
|
got_one = true;
|
|
else
|
|
continue;
|
|
if ((rwflags == O_RDONLY && !(cfd->get_access () & GENERIC_READ))
|
|
|| (rwflags == O_WRONLY && !(cfd->get_access () & GENERIC_WRITE)))
|
|
continue;
|
|
cfd->copyto (this);
|
|
set_io_handle (NULL);
|
|
pc.reset_conv_handle ();
|
|
if (!cfd->dup (this, flags))
|
|
return 1;
|
|
return 0;
|
|
}
|
|
/* Found the pipe but access mode didn't match? EACCES.
|
|
Otherwise ENOENT */
|
|
set_errno (got_one ? EACCES : ENOENT);
|
|
return 0;
|
|
}
|
|
|
|
pinfo p (pid);
|
|
if (!p)
|
|
{
|
|
set_errno (ESRCH);
|
|
return 0;
|
|
}
|
|
if (!(proc = OpenProcess (PROCESS_DUP_HANDLE, false, p->dwProcessId)))
|
|
{
|
|
__seterrno ();
|
|
return 0;
|
|
}
|
|
fhr = p->pipe_fhandler (uniq_id, size);
|
|
if (fhr && rwflags == O_RDONLY)
|
|
fh = fhr;
|
|
else
|
|
{
|
|
fhw = p->pipe_fhandler (uniq_id + 1, size);
|
|
if (fhw && rwflags == O_WRONLY)
|
|
fh = fhw;
|
|
}
|
|
if (!fh)
|
|
{
|
|
/* Too bad, but Windows only allows the same access mode when dup'ing
|
|
the pipe. */
|
|
set_errno (fhr || fhw ? EACCES : ENOENT);
|
|
goto out;
|
|
}
|
|
inh = !(flags & O_CLOEXEC);
|
|
if (!DuplicateHandle (proc, fh->get_handle (), GetCurrentProcess (),
|
|
&nio_hdl, 0, inh, DUPLICATE_SAME_ACCESS))
|
|
{
|
|
__seterrno ();
|
|
goto out;
|
|
}
|
|
init (nio_hdl, fh->get_access (), mode & O_TEXT ?: O_BINARY,
|
|
fh->get_plain_ino ());
|
|
cfree (fh);
|
|
CloseHandle (proc);
|
|
return 1;
|
|
out:
|
|
if (nio_hdl)
|
|
CloseHandle (nio_hdl);
|
|
if (fh)
|
|
free (fh);
|
|
if (proc)
|
|
CloseHandle (proc);
|
|
return 0;
|
|
}
|
|
|
|
off_t
|
|
fhandler_pipe::lseek (off_t offset, int whence)
|
|
{
|
|
debug_printf ("(%D, %d)", offset, whence);
|
|
set_errno (ESPIPE);
|
|
return -1;
|
|
}
|
|
|
|
int
|
|
fhandler_pipe::fadvise (off_t offset, off_t length, int advice)
|
|
{
|
|
set_errno (ESPIPE);
|
|
return -1;
|
|
}
|
|
|
|
int
|
|
fhandler_pipe::ftruncate (off_t length, bool allow_truncate)
|
|
{
|
|
set_errno (allow_truncate ? EINVAL : ESPIPE);
|
|
return -1;
|
|
}
|
|
|
|
char *
|
|
fhandler_pipe::get_proc_fd_name (char *buf)
|
|
{
|
|
__small_sprintf (buf, "pipe:[%D]", get_plain_ino ());
|
|
return buf;
|
|
}
|
|
|
|
int
|
|
fhandler_pipe::dup (fhandler_base *child, int flags)
|
|
{
|
|
fhandler_pipe *ftp = (fhandler_pipe *) child;
|
|
ftp->set_popen_pid (0);
|
|
|
|
int res;
|
|
if (get_handle () && fhandler_base_overlapped::dup (child, flags))
|
|
res = -1;
|
|
else
|
|
res = 0;
|
|
|
|
debug_printf ("res %d", res);
|
|
return res;
|
|
}
|
|
|
|
#define PIPE_INTRO "\\\\.\\pipe\\cygwin-"
|
|
|
|
/* Create a pipe, and return handles to the read and write ends,
|
|
just like CreatePipe, but ensure that the write end permits
|
|
FILE_READ_ATTRIBUTES access, on later versions of win32 where
|
|
this is supported. This access is needed by NtQueryInformationFile,
|
|
which is used to implement select and nonblocking writes.
|
|
Note that the return value is either 0 or GetLastError,
|
|
unlike CreatePipe, which returns a bool for success or failure. */
|
|
DWORD
|
|
fhandler_pipe::create (LPSECURITY_ATTRIBUTES sa_ptr, PHANDLE r, PHANDLE w,
|
|
DWORD psize, const char *name, DWORD open_mode,
|
|
int64_t *unique_id)
|
|
{
|
|
/* Default to error. */
|
|
if (r)
|
|
*r = NULL;
|
|
if (w)
|
|
*w = NULL;
|
|
|
|
/* Ensure that there is enough pipe buffer space for atomic writes. */
|
|
if (!psize)
|
|
psize = DEFAULT_PIPEBUFSIZE;
|
|
|
|
char pipename[MAX_PATH];
|
|
size_t len = __small_sprintf (pipename, PIPE_INTRO "%S-",
|
|
&cygheap->installation_key);
|
|
DWORD pipe_mode = PIPE_READMODE_BYTE | PIPE_REJECT_REMOTE_CLIENTS;
|
|
if (!name)
|
|
pipe_mode |= pipe_byte ? PIPE_TYPE_BYTE : PIPE_TYPE_MESSAGE;
|
|
else
|
|
pipe_mode |= PIPE_TYPE_MESSAGE;
|
|
|
|
if (!name || (open_mode & PIPE_ADD_PID))
|
|
{
|
|
len += __small_sprintf (pipename + len, "%u-", GetCurrentProcessId ());
|
|
open_mode &= ~PIPE_ADD_PID;
|
|
}
|
|
|
|
if (name)
|
|
len += __small_sprintf (pipename + len, "%s", name);
|
|
|
|
open_mode |= PIPE_ACCESS_INBOUND | 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)
|
|
{
|
|
static volatile ULONG pipe_unique_id;
|
|
if (!name)
|
|
{
|
|
LONG id = InterlockedIncrement ((LONG *) &pipe_unique_id);
|
|
__small_sprintf (pipename + len, "pipe-%p", id);
|
|
if (unique_id)
|
|
*unique_id = ((int64_t) id << 32 | GetCurrentProcessId ());
|
|
}
|
|
|
|
debug_printf ("name %s, size %u, mode %s", pipename, psize,
|
|
(pipe_mode & PIPE_TYPE_MESSAGE)
|
|
? "PIPE_TYPE_MESSAGE" : "PIPE_TYPE_BYTE");
|
|
|
|
/* Use CreateNamedPipe instead of CreatePipe, because the latter
|
|
returns a write handle that does not permit FILE_READ_ATTRIBUTES
|
|
access, on versions of win32 earlier than WinXP SP2.
|
|
CreatePipe also stupidly creates a full duplex pipe, which is
|
|
a waste, since only a single direction is actually used.
|
|
It's important to only allow a single instance, to ensure that
|
|
the pipe was not created earlier by some other process, even if
|
|
the pid has been reused.
|
|
|
|
Note that the write side of the pipe is opened as PIPE_TYPE_MESSAGE.
|
|
This *seems* to more closely mimic Linux pipe behavior and is
|
|
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,
|
|
psize, NMPWAIT_USE_DEFAULT_WAIT, sa_ptr);
|
|
|
|
if (*r != INVALID_HANDLE_VALUE)
|
|
{
|
|
debug_printf ("pipe read handle %p", *r);
|
|
err = 0;
|
|
break;
|
|
}
|
|
|
|
err = GetLastError ();
|
|
switch (err)
|
|
{
|
|
case ERROR_PIPE_BUSY:
|
|
/* The pipe is already open with compatible parameters.
|
|
Pick a new name and retry. */
|
|
debug_printf ("pipe busy", !name ? ", retrying" : "");
|
|
if (!name)
|
|
*r = 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;
|
|
break;
|
|
default:
|
|
{
|
|
err = GetLastError ();
|
|
debug_printf ("failed, %E");
|
|
}
|
|
}
|
|
}
|
|
|
|
if (err)
|
|
{
|
|
*r = NULL;
|
|
return err;
|
|
}
|
|
|
|
if (!w)
|
|
debug_printf ("pipe write 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;
|
|
if ((open_mode & PIPE_ACCESS_DUPLEX) == PIPE_ACCESS_DUPLEX)
|
|
access |= GENERIC_READ | FILE_WRITE_ATTRIBUTES;
|
|
*w = CreateFile (pipename, access, 0, sa_ptr, OPEN_EXISTING,
|
|
open_mode & FILE_FLAG_OVERLAPPED, 0);
|
|
|
|
if (!*w || *w == INVALID_HANDLE_VALUE)
|
|
{
|
|
/* Failure. */
|
|
DWORD err = GetLastError ();
|
|
debug_printf ("CreateFile 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::create (fhandler_pipe *fhs[2], unsigned psize, int mode)
|
|
{
|
|
HANDLE r, w;
|
|
SECURITY_ATTRIBUTES *sa = sec_none_cloexec (mode);
|
|
int res = -1;
|
|
int64_t unique_id;
|
|
|
|
int ret = create (sa, &r, &w, psize, NULL, FILE_FLAG_OVERLAPPED, &unique_id);
|
|
if (ret)
|
|
__seterrno_from_win_error (ret);
|
|
else if ((fhs[0] = (fhandler_pipe *) build_fh_dev (*piper_dev)) == NULL)
|
|
{
|
|
CloseHandle (r);
|
|
CloseHandle (w);
|
|
}
|
|
else if ((fhs[1] = (fhandler_pipe *) build_fh_dev (*pipew_dev)) == NULL)
|
|
{
|
|
delete fhs[0];
|
|
CloseHandle (w);
|
|
}
|
|
else
|
|
{
|
|
mode |= mode & O_TEXT ?: O_BINARY;
|
|
fhs[0]->init (r, FILE_CREATE_PIPE_INSTANCE | GENERIC_READ, mode,
|
|
unique_id);
|
|
fhs[1]->init (w, FILE_CREATE_PIPE_INSTANCE | GENERIC_WRITE, mode,
|
|
unique_id);
|
|
res = 0;
|
|
}
|
|
|
|
debug_printf ("%R = pipe([%p, %p], %d, %y)", res, fhs[0], fhs[1], psize, mode);
|
|
return res;
|
|
}
|
|
|
|
int
|
|
fhandler_pipe::ioctl (unsigned int cmd, void *p)
|
|
{
|
|
int n;
|
|
|
|
switch (cmd)
|
|
{
|
|
case FIONREAD:
|
|
if (get_device () == FH_PIPEW)
|
|
{
|
|
set_errno (EINVAL);
|
|
return -1;
|
|
}
|
|
if (!PeekNamedPipe (get_handle (), NULL, 0, NULL, (DWORD *) &n, NULL))
|
|
{
|
|
__seterrno ();
|
|
return -1;
|
|
}
|
|
break;
|
|
default:
|
|
return fhandler_base::ioctl (cmd, p);
|
|
break;
|
|
}
|
|
*(int *) p = n;
|
|
return 0;
|
|
}
|
|
|
|
int __reg2
|
|
fhandler_pipe::fstat (struct stat *buf)
|
|
{
|
|
int ret = fhandler_base::fstat (buf);
|
|
if (!ret)
|
|
{
|
|
buf->st_dev = FH_PIPE;
|
|
if (!(buf->st_ino = get_plain_ino ()))
|
|
sscanf (get_name (), "/proc/%*d/fd/pipe:[%lld]",
|
|
(long long *) &buf->st_ino);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
int __reg2
|
|
fhandler_pipe::fstatvfs (struct statvfs *sfs)
|
|
{
|
|
set_errno (EBADF);
|
|
return -1;
|
|
}
|
|
|
|
static int __reg3
|
|
pipe_worker (int filedes[2], unsigned int psize, int mode)
|
|
{
|
|
fhandler_pipe *fhs[2];
|
|
int res = fhandler_pipe::create (fhs, psize, mode);
|
|
if (!res)
|
|
{
|
|
cygheap_fdnew fdin;
|
|
cygheap_fdnew fdout (fdin, false);
|
|
char buf[sizeof ("/dev/fd/pipe:[9223372036854775807]")];
|
|
__small_sprintf (buf, "/dev/fd/pipe:[%D]", fhs[0]->get_plain_ino ());
|
|
fhs[0]->pc.set_posix (buf);
|
|
__small_sprintf (buf, "pipe:[%D]", fhs[1]->get_plain_ino ());
|
|
fhs[1]->pc.set_posix (buf);
|
|
fdin = fhs[0];
|
|
fdout = fhs[1];
|
|
filedes[0] = fdin;
|
|
filedes[1] = fdout;
|
|
}
|
|
return res;
|
|
}
|
|
|
|
extern "C" int
|
|
_pipe (int filedes[2], unsigned int psize, int mode)
|
|
{
|
|
int res = pipe_worker (filedes, psize, mode);
|
|
int read, write;
|
|
if (res != 0)
|
|
read = write = -1;
|
|
else
|
|
{
|
|
read = filedes[0];
|
|
write = filedes[1];
|
|
}
|
|
syscall_printf ("%R = _pipe([%d, %d], %u, %y)", res, read, write, psize, mode);
|
|
return res;
|
|
}
|
|
|
|
extern "C" int
|
|
pipe (int filedes[2])
|
|
{
|
|
int res = pipe_worker (filedes, DEFAULT_PIPEBUFSIZE, O_BINARY);
|
|
int read, write;
|
|
if (res != 0)
|
|
read = write = -1;
|
|
else
|
|
{
|
|
read = filedes[0];
|
|
write = filedes[1];
|
|
}
|
|
syscall_printf ("%R = pipe([%d, %d])", res, read, write);
|
|
return res;
|
|
}
|
|
|
|
extern "C" int
|
|
pipe2 (int filedes[2], int mode)
|
|
{
|
|
int res = pipe_worker (filedes, DEFAULT_PIPEBUFSIZE, mode);
|
|
int read, write;
|
|
if (res != 0)
|
|
read = write = -1;
|
|
else
|
|
{
|
|
read = filedes[0];
|
|
write = filedes[1];
|
|
}
|
|
syscall_printf ("%R = pipe2([%d, %d], %y)", res, read, write, mode);
|
|
return res;
|
|
}
|