1 files changed, 592 insertions, 0 deletions

diff --git a/win32/select.c b/win32/select.c
new file mode 100644
index 000000000..2be221ac8
--- /dev/null
+++ b/win32/select.c
@@ -0,0 +1,592 @@
+/* Emulation for select(2)
+   Contributed by Paolo Bonzini.
+
+   Copyright 2008-2021 Free Software Foundation, Inc.
+
+   This file is part of gnulib.
+
+   This file is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of the
+   License, or (at your option) any later version.
+
+   This file is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+#include "libbb.h"
+
+/* Specification.  */
+#include <sys/select.h>
+
+#if defined _WIN32 && ! defined __CYGWIN__
+/* Native Windows.  */
+
+#include <malloc.h>
+#include <assert.h>
+#include <sys/types.h>
+#include <errno.h>
+#include <limits.h>
+
+#include <winsock2.h>
+#include <windows.h>
+#include <io.h>
+#include <stdio.h>
+#include <conio.h>
+#include <time.h>
+
+/* Get the overridden 'struct timeval'.  */
+
+#undef select
+
+/* Don't assume that UNICODE is not defined.  */
+#undef GetModuleHandle
+#define GetModuleHandle GetModuleHandleA
+#undef PeekConsoleInput
+#define PeekConsoleInput PeekConsoleInputA
+#undef CreateEvent
+#define CreateEvent CreateEventA
+#undef PeekMessage
+#define PeekMessage PeekMessageA
+#undef DispatchMessage
+#define DispatchMessage DispatchMessageA
+
+/* Avoid warnings from gcc -Wcast-function-type.  */
+#define GetProcAddress \
+  (void *) GetProcAddress
+
+struct bitset {
+  unsigned char in[FD_SETSIZE / CHAR_BIT];
+  unsigned char out[FD_SETSIZE / CHAR_BIT];
+};
+
+/* Declare data structures for ntdll functions.  */
+typedef struct _FILE_PIPE_LOCAL_INFORMATION {
+  ULONG NamedPipeType;
+  ULONG NamedPipeConfiguration;
+  ULONG MaximumInstances;
+  ULONG CurrentInstances;
+  ULONG InboundQuota;
+  ULONG ReadDataAvailable;
+  ULONG OutboundQuota;
+  ULONG WriteQuotaAvailable;
+  ULONG NamedPipeState;
+  ULONG NamedPipeEnd;
+} FILE_PIPE_LOCAL_INFORMATION, *PFILE_PIPE_LOCAL_INFORMATION;
+
+typedef struct _IO_STATUS_BLOCK
+{
+  union {
+    DWORD Status;
+    PVOID Pointer;
+  } u;
+  ULONG_PTR Information;
+} IO_STATUS_BLOCK, *PIO_STATUS_BLOCK;
+
+typedef enum _FILE_INFORMATION_CLASS {
+  FilePipeLocalInformation = 24
+} FILE_INFORMATION_CLASS, *PFILE_INFORMATION_CLASS;
+
+typedef DWORD (WINAPI *PNtQueryInformationFile)
+         (HANDLE, IO_STATUS_BLOCK *, VOID *, ULONG, FILE_INFORMATION_CLASS);
+
+#ifndef PIPE_BUF
+#define PIPE_BUF        512
+#endif
+
+static BOOL IsConsoleHandle (HANDLE h)
+{
+  DWORD mode;
+  return GetConsoleMode (h, &mode) != 0;
+}
+
+static BOOL
+IsSocketHandle (HANDLE h)
+{
+  WSANETWORKEVENTS ev;
+
+  if (IsConsoleHandle (h))
+    return FALSE;
+
+  /* Under Wine, it seems that getsockopt returns 0 for pipes too.
+     WSAEnumNetworkEvents instead distinguishes the two correctly.  */
+  ev.lNetworkEvents = 0xDEADBEEF;
+  WSAEnumNetworkEvents ((SOCKET) h, NULL, &ev);
+  return ev.lNetworkEvents != 0xDEADBEEF;
+}
+
+/* Compute output fd_sets for libc descriptor FD (whose Windows handle is
+   H).  */
+
+static int
+windows_poll_handle (HANDLE h, int fd,
+                     struct bitset *rbits,
+                     struct bitset *wbits,
+                     struct bitset *xbits)
+{
+  BOOL read, write, except;
+  int i, ret;
+  INPUT_RECORD *irbuffer;
+  DWORD avail, nbuffer;
+  BOOL bRet;
+  IO_STATUS_BLOCK iosb;
+  FILE_PIPE_LOCAL_INFORMATION fpli;
+  static PNtQueryInformationFile NtQueryInformationFile;
+  static BOOL once_only;
+
+  read = write = except = FALSE;
+  switch (GetFileType (h))
+    {
+    case FILE_TYPE_DISK:
+      read = TRUE;
+      write = TRUE;
+      break;
+
+    case FILE_TYPE_PIPE:
+      if (!once_only)
+        {
+          NtQueryInformationFile = (PNtQueryInformationFile)
+            GetProcAddress (GetModuleHandle ("ntdll.dll"),
+                            "NtQueryInformationFile");
+          once_only = TRUE;
+        }
+
+      if (PeekNamedPipe (h, NULL, 0, NULL, &avail, NULL) != 0)
+        {
+          if (avail)
+            read = TRUE;
+        }
+      else if (GetLastError () == ERROR_BROKEN_PIPE)
+        read = TRUE;
+
+      else
+        {
+          /* It was the write-end of the pipe.  Check if it is writable.
+             If NtQueryInformationFile fails, optimistically assume the pipe is
+             writable.  This could happen on Windows 9x, where
+             NtQueryInformationFile is not available, or if we inherit a pipe
+             that doesn't permit FILE_READ_ATTRIBUTES access on the write end
+             (I think this should not happen since Windows XP SP2; WINE seems
+             fine too).  Otherwise, ensure that enough space is available for
+             atomic writes.  */
+          memset (&iosb, 0, sizeof (iosb));
+          memset (&fpli, 0, sizeof (fpli));
+
+          if (!NtQueryInformationFile
+              || NtQueryInformationFile (h, &iosb, &fpli, sizeof (fpli),
+                                         FilePipeLocalInformation)
+              || fpli.WriteQuotaAvailable >= PIPE_BUF
+              || (fpli.OutboundQuota < PIPE_BUF &&
+                  fpli.WriteQuotaAvailable == fpli.OutboundQuota))
+            write = TRUE;
+        }
+      break;
+
+    case FILE_TYPE_CHAR:
+      write = TRUE;
+      if (!(rbits->in[fd / CHAR_BIT] & (1 << (fd & (CHAR_BIT - 1)))))
+        break;
+
+      ret = WaitForSingleObject (h, 0);
+      if (ret == WAIT_OBJECT_0)
+        {
+          if (!IsConsoleHandle (h))
+            {
+              read = TRUE;
+              break;
+            }
+
+          nbuffer = avail = 0;
+          bRet = GetNumberOfConsoleInputEvents (h, &nbuffer);
+
+          /* Screen buffers handles are filtered earlier.  */
+          assert (bRet);
+          if (nbuffer == 0)
+            {
+              except = TRUE;
+              break;
+            }
+
+          irbuffer = (INPUT_RECORD *) alloca (nbuffer * sizeof (INPUT_RECORD));
+          bRet = PeekConsoleInput (h, irbuffer, nbuffer, &avail);
+          if (!bRet || avail == 0)
+            {
+              except = TRUE;
+              break;
+            }
+
+          for (i = 0; i < avail; i++)
+            if (irbuffer[i].EventType == KEY_EVENT &&
+                irbuffer[i].Event.KeyEvent.bKeyDown)
+              read = TRUE;
+        }
+      break;
+
+    default:
+      ret = WaitForSingleObject (h, 0);
+      write = TRUE;
+      if (ret == WAIT_OBJECT_0)
+        read = TRUE;
+
+      break;
+    }
+
+  ret = 0;
+  if (read && (rbits->in[fd / CHAR_BIT] & (1 << (fd & (CHAR_BIT - 1)))))
+    {
+      rbits->out[fd / CHAR_BIT] |= (1 << (fd & (CHAR_BIT - 1)));
+      ret++;
+    }
+
+  if (write && (wbits->in[fd / CHAR_BIT] & (1 << (fd & (CHAR_BIT - 1)))))
+    {
+      wbits->out[fd / CHAR_BIT] |= (1 << (fd & (CHAR_BIT - 1)));
+      ret++;
+    }
+
+  if (except && (xbits->in[fd / CHAR_BIT] & (1 << (fd & (CHAR_BIT - 1)))))
+    {
+      xbits->out[fd / CHAR_BIT] |= (1 << (fd & (CHAR_BIT - 1)));
+      ret++;
+    }
+
+  return ret;
+}
+
+int
+mingw_select (int nfds, fd_set *rfds, fd_set *wfds, fd_set *xfds,
+            struct timeval *timeout)
+#undef timeval
+{
+  static struct timeval tv0;
+  static HANDLE hEvent;
+  HANDLE h, handle_array[FD_SETSIZE + 2];
+  fd_set handle_rfds, handle_wfds, handle_xfds;
+  struct bitset rbits, wbits, xbits;
+  unsigned char anyfds_in[FD_SETSIZE / CHAR_BIT];
+  DWORD ret, wait_timeout, nhandles, nsock, nbuffer;
+  MSG msg;
+  int i, fd, rc;
+  clock_t tend = 0;
+
+  if (nfds > FD_SETSIZE)
+    nfds = FD_SETSIZE;
+
+  if (!timeout)
+    wait_timeout = INFINITE;
+  else
+    {
+      wait_timeout = timeout->tv_sec * 1000 + timeout->tv_usec / 1000;
+
+      /* select is also used as a portable usleep.  */
+      if (!rfds && !wfds && !xfds)
+        {
+          Sleep (wait_timeout);
+          return 0;
+        }
+    }
+
+  if (!hEvent)
+    hEvent = CreateEvent (NULL, FALSE, FALSE, NULL);
+
+  handle_array[0] = hEvent;
+  nhandles = 1;
+  nsock = 0;
+
+  /* Copy descriptors to bitsets.  At the same time, eliminate
+     bits in the "wrong" direction for console input buffers
+     and screen buffers, because screen buffers are waitable
+     and they will block until a character is available.  */
+  memset (&rbits, 0, sizeof (rbits));
+  memset (&wbits, 0, sizeof (wbits));
+  memset (&xbits, 0, sizeof (xbits));
+  memset (anyfds_in, 0, sizeof (anyfds_in));
+  if (rfds)
+    for (i = 0; i < rfds->fd_count; i++)
+      {
+        fd = rfds->fd_array[i];
+        h = (HANDLE) _get_osfhandle (fd);
+        if (IsConsoleHandle (h)
+            && !GetNumberOfConsoleInputEvents (h, &nbuffer))
+          continue;
+
+        rbits.in[fd / CHAR_BIT] |= 1 << (fd & (CHAR_BIT - 1));
+        anyfds_in[fd / CHAR_BIT] |= 1 << (fd & (CHAR_BIT - 1));
+      }
+  else
+    rfds = (fd_set *) alloca (sizeof (fd_set));
+
+  if (wfds)
+    for (i = 0; i < wfds->fd_count; i++)
+      {
+        fd = wfds->fd_array[i];
+        h = (HANDLE) _get_osfhandle (fd);
+        if (IsConsoleHandle (h)
+            && GetNumberOfConsoleInputEvents (h, &nbuffer))
+          continue;
+
+        wbits.in[fd / CHAR_BIT] |= 1 << (fd & (CHAR_BIT - 1));
+        anyfds_in[fd / CHAR_BIT] |= 1 << (fd & (CHAR_BIT - 1));
+      }
+  else
+    wfds = (fd_set *) alloca (sizeof (fd_set));
+
+  if (xfds)
+    for (i = 0; i < xfds->fd_count; i++)
+      {
+        fd = xfds->fd_array[i];
+        xbits.in[fd / CHAR_BIT] |= 1 << (fd & (CHAR_BIT - 1));
+        anyfds_in[fd / CHAR_BIT] |= 1 << (fd & (CHAR_BIT - 1));
+      }
+  else
+    xfds = (fd_set *) alloca (sizeof (fd_set));
+
+  /* Zero all the fd_sets, including the application's.  */
+  FD_ZERO (rfds);
+  FD_ZERO (wfds);
+  FD_ZERO (xfds);
+  FD_ZERO (&handle_rfds);
+  FD_ZERO (&handle_wfds);
+  FD_ZERO (&handle_xfds);
+
+  /* Classify handles.  Create fd sets for sockets, poll the others. */
+  for (i = 0; i < nfds; i++)
+    {
+      if ((anyfds_in[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1)))) == 0)
+        continue;
+
+      h = (HANDLE) _get_osfhandle (i);
+      if (!h)
+        {
+          errno = EBADF;
+          return -1;
+        }
+
+      if (IsSocketHandle (h))
+        {
+          int requested = FD_CLOSE;
+
+          /* See above; socket handles are mapped onto select, but we
+             need to map descriptors to handles.  */
+          if (rbits.in[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1))))
+            {
+              requested |= FD_READ | FD_ACCEPT;
+              FD_SET ((SOCKET) h, rfds);
+              FD_SET ((SOCKET) h, &handle_rfds);
+            }
+          if (wbits.in[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1))))
+            {
+              requested |= FD_WRITE | FD_CONNECT;
+              FD_SET ((SOCKET) h, wfds);
+              FD_SET ((SOCKET) h, &handle_wfds);
+            }
+          if (xbits.in[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1))))
+            {
+              requested |= FD_OOB;
+              FD_SET ((SOCKET) h, xfds);
+              FD_SET ((SOCKET) h, &handle_xfds);
+            }
+
+          WSAEventSelect ((SOCKET) h, hEvent, requested);
+          nsock++;
+        }
+      else
+        {
+          handle_array[nhandles++] = h;
+
+          /* Poll now.  If we get an event, do not wait below.  */
+          if (wait_timeout != 0
+              && windows_poll_handle (h, i, &rbits, &wbits, &xbits))
+            wait_timeout = 0;
+        }
+    }
+
+  /* Place a sentinel at the end of the array.  */
+  handle_array[nhandles] = NULL;
+
+  /* When will the waiting period expire?  */
+  if (wait_timeout != INFINITE)
+    tend = clock () + wait_timeout;
+
+restart:
+  if (wait_timeout == 0 || nsock == 0)
+    rc = 0;
+  else
+    {
+      /* See if we need to wait in the loop below.  If any select is ready,
+         do MsgWaitForMultipleObjects anyway to dispatch messages, but
+         no need to call select again.  */
+      rc = select (0, &handle_rfds, &handle_wfds, &handle_xfds, &tv0);
+      if (rc == 0)
+        {
+          /* Restore the fd_sets for the other select we do below.  */
+          memcpy (&handle_rfds, rfds, sizeof (fd_set));
+          memcpy (&handle_wfds, wfds, sizeof (fd_set));
+          memcpy (&handle_xfds, xfds, sizeof (fd_set));
+        }
+      else
+        wait_timeout = 0;
+    }
+
+  /* How much is left to wait?  */
+  if (wait_timeout != INFINITE)
+    {
+      clock_t tnow = clock ();
+      if (tend >= tnow)
+        wait_timeout = tend - tnow;
+      else
+        wait_timeout = 0;
+    }
+
+  for (;;)
+    {
+      ret = MsgWaitForMultipleObjects (nhandles, handle_array, FALSE,
+                                       wait_timeout, QS_ALLINPUT);
+
+      if (ret == WAIT_OBJECT_0 + nhandles)
+        {
+          /* new input of some other kind */
+          BOOL bRet;
+          while ((bRet = PeekMessage (&msg, NULL, 0, 0, PM_REMOVE)) != 0)
+            {
+              TranslateMessage (&msg);
+              DispatchMessage (&msg);
+            }
+        }
+      else
+        break;
+    }
+
+  /* If we haven't done it yet, check the status of the sockets.  */
+  if (rc == 0 && nsock > 0)
+    rc = select (0, &handle_rfds, &handle_wfds, &handle_xfds, &tv0);
+
+  if (nhandles > 1)
+    {
+      /* Count results that are not counted in the return value of select.  */
+      nhandles = 1;
+      for (i = 0; i < nfds; i++)
+        {
+          if ((anyfds_in[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1)))) == 0)
+            continue;
+
+          h = (HANDLE) _get_osfhandle (i);
+          if (h == handle_array[nhandles])
+            {
+              /* Not a socket.  */
+              nhandles++;
+              windows_poll_handle (h, i, &rbits, &wbits, &xbits);
+              if (rbits.out[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1)))
+                  || wbits.out[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1)))
+                  || xbits.out[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1))))
+                rc++;
+            }
+        }
+
+      if (rc == 0
+          && (wait_timeout == INFINITE
+              /* If NHANDLES > 1, but no bits are set, it means we've
+                 been told incorrectly that some handle was signaled.
+                 This happens with anonymous pipes, which always cause
+                 MsgWaitForMultipleObjects to exit immediately, but no
+                 data is found ready to be read by windows_poll_handle.
+                 To avoid a total failure (whereby we return zero and
+                 don't wait at all), let's poll in a more busy loop.  */
+              || (wait_timeout != 0 && nhandles > 1)))
+        {
+          /* Sleep 1 millisecond to avoid busy wait and retry with the
+             original fd_sets.  */
+          memcpy (&handle_rfds, rfds, sizeof (fd_set));
+          memcpy (&handle_wfds, wfds, sizeof (fd_set));
+          memcpy (&handle_xfds, xfds, sizeof (fd_set));
+          SleepEx (1, TRUE);
+          goto restart;
+        }
+      if (timeout && wait_timeout == 0 && rc == 0)
+        timeout->tv_sec = timeout->tv_usec = 0;
+    }
+
+  /* Now fill in the results.  */
+  FD_ZERO (rfds);
+  FD_ZERO (wfds);
+  FD_ZERO (xfds);
+  nhandles = 1;
+  for (i = 0; i < nfds; i++)
+    {
+      if ((anyfds_in[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1)))) == 0)
+        continue;
+
+      h = (HANDLE) _get_osfhandle (i);
+      if (h != handle_array[nhandles])
+        {
+          /* Perform handle->descriptor mapping.  */
+          SOCKET s = (SOCKET) h;
+          WSAEventSelect (s, NULL, 0);
+          if (FD_ISSET (s, &handle_rfds))
+            FD_SET (i, rfds);
+          if (FD_ISSET (s, &handle_wfds))
+            FD_SET (i, wfds);
+          if (FD_ISSET (s, &handle_xfds))
+            FD_SET (i, xfds);
+        }
+      else
+        {
+          /* Not a socket.  */
+          nhandles++;
+          if (rbits.out[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1))))
+            FD_SET (i, rfds);
+          if (wbits.out[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1))))
+            FD_SET (i, wfds);
+          if (xbits.out[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1))))
+            FD_SET (i, xfds);
+        }
+    }
+
+  return rc;
+}
+
+#else /* ! Native Windows.  */
+
+#include <stddef.h> /* NULL */
+#include <errno.h>
+#include <unistd.h>
+
+#undef select
+
+int
+rpl_select (int nfds, fd_set *rfds, fd_set *wfds, fd_set *xfds,
+            struct timeval *timeout)
+{
+  int i;
+
+  /* FreeBSD 8.2 has a bug: it does not always detect invalid fds.  */
+  if (nfds < 0 || nfds > FD_SETSIZE)
+    {
+      errno = EINVAL;
+      return -1;
+    }
+  for (i = 0; i < nfds; i++)
+    {
+      if (((rfds && FD_ISSET (i, rfds))
+           || (wfds && FD_ISSET (i, wfds))
+           || (xfds && FD_ISSET (i, xfds)))
+          && dup2 (i, i) != i)
+        return -1;
+    }
+
+  /* Interix 3.5 has a bug: it does not support nfds == 0.  */
+  if (nfds == 0)
+    {
+      nfds = 1;
+      rfds = NULL;
+      wfds = NULL;
+      xfds = NULL;
+    }
+  return select (nfds, rfds, wfds, xfds, timeout);
+}
+
+#endif