path: root/winsup/cygwin/miscfuncs.cc

/* miscfuncs.cc: misc funcs that don't belong anywhere else

   Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
   2005, 2006, 2007, 2008 Red Hat, Inc.

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. */

#include "winsup.h"
#include "miscfuncs.h"
#include <sys/uio.h>
#include <assert.h>
#include <alloca.h>
#include <limits.h>
#include <wchar.h>
#include <wingdi.h>
#include <winuser.h>
#include <winnls.h>
#include "cygtls.h"
#include "ntdll.h"

long tls_ix = -1;

const char case_folded_lower[] NO_COPY = {
   0,   1,   2,   3,   4,   5,   6,   7,   8,   9,  10,  11,  12,  13,  14,  15,
  16,  17,  18,  19,  20,  21,  22,  23,  24,  25,  26,  27,  28,  29,  30,  31,
  32, '!', '"', '#', '$', '%', '&',  39, '(', ')', '*', '+', ',', '-', '.', '/',
 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', ':', ';', '<', '=', '>', '?',
 '@', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o',
 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '[',  92, ']', '^', '_',
 '`', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o',
 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '{', '|', '}', '~', 127,
 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143,
 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159,
 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175,
 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191,
 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207,
 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223,
 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239,
 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255
};

const char case_folded_upper[] NO_COPY = {
   0,   1,   2,   3,   4,   5,   6,   7,   8,   9,  10,  11,  12,  13,  14,  15,
  16,  17,  18,  19,  20,  21,  22,  23,  24,  25,  26,  27,  28,  29,  30,  31,
  32, '!', '"', '#', '$', '%', '&',  39, '(', ')', '*', '+', ',', '-', '.', '/',
 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', ':', ';', '<', '=', '>', '?',
 '@', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O',
 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', '[',  92, ']', '^', '_',
 '`', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O',
 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', '{', '|', '}', '~', 127,
 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143,
 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159,
 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175,
 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191,
 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207,
 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223,
 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239,
 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255
};

const char isalpha_array[] NO_COPY = {
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,
0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,   0,   0,   0,   0,   0,
   0,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,
0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0
};

extern "C" int __stdcall
cygwin_wcscasecmp (const wchar_t *ws, const wchar_t *wt)
{
  UNICODE_STRING us, ut;

  RtlInitUnicodeString (&us, ws);
  RtlInitUnicodeString (&ut, wt);
  return RtlCompareUnicodeString (&us, &ut, TRUE);
}

extern "C" int __stdcall
cygwin_wcsncasecmp (const wchar_t  *ws, const wchar_t *wt, size_t n)
{
  UNICODE_STRING us, ut;
  size_t ls = 0, lt = 0;

  while (ws[ls] && ls < n)
    ++ls;
  RtlInitCountedUnicodeString (&us, ws, ls * sizeof (WCHAR));
  while (wt[lt] && lt < n)
    ++lt;
  RtlInitCountedUnicodeString (&ut, wt, lt * sizeof (WCHAR));
  return RtlCompareUnicodeString (&us, &ut, TRUE);
}

extern "C" int __stdcall
cygwin_strcasecmp (const char *cs, const char *ct)
{
  UNICODE_STRING us, ut;
  ULONG len;

  len = (strlen (cs) + 1) * sizeof (WCHAR);
  RtlInitEmptyUnicodeString (&us, (PWCHAR) alloca (len), len);
  us.Length = sys_mbstowcs (us.Buffer, us.MaximumLength, cs) * sizeof (WCHAR);
  len = (strlen (ct) + 1) * sizeof (WCHAR);
  RtlInitEmptyUnicodeString (&ut, (PWCHAR) alloca (len), len);
  ut.Length = sys_mbstowcs (ut.Buffer, ut.MaximumLength, ct) * sizeof (WCHAR);
  return RtlCompareUnicodeString (&us, &ut, TRUE);
}

extern "C" int __stdcall
cygwin_strncasecmp (const char *cs, const char *ct, size_t n)
{
  UNICODE_STRING us, ut;
  ULONG len;
  size_t ls = 0, lt = 0;

  while (cs[ls] && ls < n)
    ++ls;
  len = (ls + 1) * sizeof (WCHAR);
  RtlInitEmptyUnicodeString (&us, (PWCHAR) alloca (len), len);
  us.Length = sys_mbstowcs (us.Buffer, ls + 1, cs, ls) * sizeof (WCHAR);
  while (ct[lt] && lt < n)
    ++lt;
  len = (lt + 1) * sizeof (WCHAR);
  RtlInitEmptyUnicodeString (&ut, (PWCHAR) alloca (len), len);
  ut.Length = sys_mbstowcs (ut.Buffer, lt + 1, ct, lt)  * sizeof (WCHAR);
  return RtlCompareUnicodeString (&us, &ut, TRUE);
}

extern "C" wchar_t * __stdcall
cygwin_wcslwr (wchar_t *string)
{
  UNICODE_STRING us;

  RtlInitUnicodeString (&us, string);
  RtlDowncaseUnicodeString (&us, &us, FALSE);
  return string;
}

extern "C" wchar_t * __stdcall
cygwin_wcsupr (wchar_t *string)
{
  UNICODE_STRING us;

  RtlInitUnicodeString (&us, string);
  RtlUpcaseUnicodeString (&us, &us, FALSE);
  return string;
}

extern "C" char * __stdcall
cygwin_strlwr (char *string)
{
  UNICODE_STRING us;
  size_t len = (strlen (string) + 1) * sizeof (WCHAR);

  us.MaximumLength = len; us.Buffer = (PWCHAR) alloca (len);
  us.Length = sys_mbstowcs (us.Buffer, len, string) * sizeof (WCHAR)
	      - sizeof (WCHAR);
  RtlDowncaseUnicodeString (&us, &us, FALSE);
  sys_wcstombs (string, len / sizeof (WCHAR), us.Buffer);
  return string;
}

extern "C" char * __stdcall
cygwin_strupr (char *string)
{
  UNICODE_STRING us;
  size_t len = (strlen (string) + 1) * sizeof (WCHAR);

  us.MaximumLength = len; us.Buffer = (PWCHAR) alloca (len);
  us.Length = sys_mbstowcs (us.Buffer, len, string) * sizeof (WCHAR)
	      - sizeof (WCHAR);
  RtlUpcaseUnicodeString (&us, &us, FALSE);
  sys_wcstombs (string, len / sizeof (WCHAR), us.Buffer);
  return string;
}

/* FIXME?  We only support standard ANSI/OEM codepages according to
   http://www.microsoft.com/globaldev/reference/cphome.mspx as well
   as UTF-8 and codepage 1361, which is also mentioned as valid
   doublebyte codepage in MSDN man pages (e.g. IsDBCSLeadByteEx).
   Everything else will be hosed. */

bool
is_cp_multibyte (UINT cp)
{
  switch (cp)
    {
    case 932:
    case 936:
    case 949:
    case 950:
    case 1361:
    case 65001:
      return true;
    }
  return false;
}

/* OMYGOD!  CharNextExA is not UTF-8 aware!  It only works fine with
   double byte charsets.  So we have to do it ourselves for UTF-8.

   While being at it, we do more.  If a double-byte or multibyte
   sequence is truncated due to an early end, we need a way to recognize
   it.  The reason is that multiple buffered write statements might
   accidentally stop and start in the middle of a single character byte
   sequence.  If we have to interpret the byte sequences (as in
   fhandler_console), we would print wrong output in these cases.

   So we have four possible return values here:

   ret = end      if str >= end
   ret = NULL	  if we encounter an invalid byte sequence
   ret = str      if we encounter the start byte of a truncated byte sequence
   ret = str + n  if we encounter a vaild byte sequence
*/

const unsigned char *
next_char (UINT cp, const unsigned char *str, const unsigned char *end)
{
  const unsigned char *ret = NULL;

  if (str >= end)
    return end;

  switch (cp)
    {
    case 932:
    case 936:
    case 949:
    case 950:
    case 1361:
      if (*str <= 0x7f)
	ret = str + 1;
      else if (str == end - 1 && IsDBCSLeadByteEx (cp, *str))
	ret = str;
      else
	ret = (const unsigned char *) CharNextExA (cp, (const CHAR *) str, 0);
      break;
    case CP_UTF8:
      switch (str[0] >> 4)
	{
	case 0x0 ... 0x7:	/* One byte character. */
	  ret = str + 1;
	  break;
	case 0x8 ... 0xb:	/* Followup byte.  Invalid as first byte. */
	  ret = NULL;
	  break;
	case 0xc ... 0xd:	/* Two byte character. */
	  /* Check followup bytes for validity. */
	  if (str >= end - 1)
	    ret = str;
	  else if (str[1] <= 0xbf)
	    ret = str + 2;
	  else
	    ret = NULL;
	  break;
	case 0xe:		/* Three byte character. */
	  if (str >= end - 2)
	    ret = str;
	  else if ((str[1] & 0xc0) == 0x80 && (str[2] & 0xc0) == 0x80
		   && (str[0] != 0xe0 || str[1] >= 0xa0)
		   && (str[0] != 0xed || str[1] <= 0x9f))
	    ret = str + 3;
	  else
	    ret = NULL;
	  break;
	case 0xf:		/* Four byte character. */
	  if (str[0] >= 0xf8)
	    ret = NULL;
	  else if (str >= end - 3)
	    ret = str;
	  else if ((str[1] & 0xc0) == 0x80 && (str[2] & 0xc0) == 0x80
		   && (str[3] & 0xc0) == 0x80
		   && (str[0] == 0xf0 || str[1] >= 0x90)
		   && (str[0] == 0xf4 || str[1] <= 0x8f))
	    ret = str + 4;
	  else
	    ret = NULL;
	  break;
	}
      break;
    default:
      ret = str + 1;
      break;
    }
  return ret;
}

int __stdcall
check_invalid_virtual_addr (const void *s, unsigned sz)
{
  MEMORY_BASIC_INFORMATION mbuf;
  const void *end;

  for (end = (char *) s + sz; s < end;
       s = (char *) mbuf.BaseAddress + mbuf.RegionSize)
    if (!VirtualQuery (s, &mbuf, sizeof mbuf))
      return EINVAL;
  return 0;
}

static char __attribute__ ((noinline))
dummytest (volatile char *p)
{
  return *p;
}

ssize_t
check_iovec (const struct iovec *iov, int iovcnt, bool forwrite)
{
  if (iovcnt <= 0 || iovcnt > IOV_MAX)
    {
      set_errno (EINVAL);
      return -1;
    }

  myfault efault;
  if (efault.faulted (EFAULT))
    return -1;

  size_t tot = 0;

  while (iovcnt != 0)
    {
      if (iov->iov_len > SSIZE_MAX || (tot += iov->iov_len) > SSIZE_MAX)
	{
	  set_errno (EINVAL);
	  return -1;
	}

      volatile char *p = ((char *) iov->iov_base) + iov->iov_len - 1;
      if (!iov->iov_len)
	/* nothing to do */;
      else if (!forwrite)
	*p  = dummytest (p);
      else
	dummytest (p);

      iov++;
      iovcnt--;
    }

  assert (tot <= SSIZE_MAX);

  return (ssize_t) tot;
}

extern "C" int
low_priority_sleep (DWORD secs)
{
  HANDLE thisthread = GetCurrentThread ();
  int curr_prio = GetThreadPriority (thisthread);
  bool staylow;
  if (secs != INFINITE)
    staylow = false;
  else
    {
      secs = 0;
      staylow = true;
    }

  if (!secs)
    {
      for (int i = 0; i < 3; i++)
	SwitchToThread ();
    }
  else
    {
      int new_prio;
      if (GetCurrentThreadId () == cygthread::main_thread_id)
	new_prio = THREAD_PRIORITY_LOWEST;
      else
	new_prio = GetThreadPriority (hMainThread);

      if (curr_prio != new_prio)
	/* Force any threads in normal priority to be scheduled */
	SetThreadPriority (thisthread, new_prio);
      Sleep (secs);

      if (!staylow && curr_prio != new_prio)
	SetThreadPriority (thisthread, curr_prio);
    }

  return curr_prio;
}

/* Get a default value for the nice factor.  When changing these values,
   have a look into the below function nice_to_winprio.  The values must
   match the layout of the static "priority" array. */
int
winprio_to_nice (DWORD prio)
{
  switch (prio)
    {
      case REALTIME_PRIORITY_CLASS:
	return -20;
      case HIGH_PRIORITY_CLASS:
	return -16;
      case ABOVE_NORMAL_PRIORITY_CLASS:
	return -8;
      case NORMAL_PRIORITY_CLASS:
	return 0;
      case BELOW_NORMAL_PRIORITY_CLASS:
	return 8;
      case IDLE_PRIORITY_CLASS:
	return 16;
    }
  return 0;
}

/* Get a Win32 priority matching the incoming nice factor.  The incoming
   nice is limited to the interval [-NZERO,NZERO-1]. */
DWORD
nice_to_winprio (int &nice)
{
  static const DWORD priority[] NO_COPY =
    {
      REALTIME_PRIORITY_CLASS,		/*  0 */
      HIGH_PRIORITY_CLASS,		/*  1 */
      HIGH_PRIORITY_CLASS,
      HIGH_PRIORITY_CLASS,
      HIGH_PRIORITY_CLASS,
      HIGH_PRIORITY_CLASS,
      HIGH_PRIORITY_CLASS,
      HIGH_PRIORITY_CLASS,		/*  7 */
      ABOVE_NORMAL_PRIORITY_CLASS,	/*  8 */
      ABOVE_NORMAL_PRIORITY_CLASS,
      ABOVE_NORMAL_PRIORITY_CLASS,
      ABOVE_NORMAL_PRIORITY_CLASS,
      ABOVE_NORMAL_PRIORITY_CLASS,
      ABOVE_NORMAL_PRIORITY_CLASS,
      ABOVE_NORMAL_PRIORITY_CLASS,
      ABOVE_NORMAL_PRIORITY_CLASS,	/* 15 */
      NORMAL_PRIORITY_CLASS,		/* 16 */
      NORMAL_PRIORITY_CLASS,
      NORMAL_PRIORITY_CLASS,
      NORMAL_PRIORITY_CLASS,
      NORMAL_PRIORITY_CLASS,
      NORMAL_PRIORITY_CLASS,
      NORMAL_PRIORITY_CLASS,
      NORMAL_PRIORITY_CLASS,		/* 23 */
      BELOW_NORMAL_PRIORITY_CLASS,	/* 24 */
      BELOW_NORMAL_PRIORITY_CLASS,
      BELOW_NORMAL_PRIORITY_CLASS,
      BELOW_NORMAL_PRIORITY_CLASS,
      BELOW_NORMAL_PRIORITY_CLASS,
      BELOW_NORMAL_PRIORITY_CLASS,
      BELOW_NORMAL_PRIORITY_CLASS,
      BELOW_NORMAL_PRIORITY_CLASS,	/* 31 */
      IDLE_PRIORITY_CLASS,		/* 32 */
      IDLE_PRIORITY_CLASS,
      IDLE_PRIORITY_CLASS,
      IDLE_PRIORITY_CLASS,
      IDLE_PRIORITY_CLASS,
      IDLE_PRIORITY_CLASS,
      IDLE_PRIORITY_CLASS,
      IDLE_PRIORITY_CLASS		/* 39 */
    };
  if (nice < -NZERO)
    nice = -NZERO;
  else if (nice > NZERO - 1)
    nice = NZERO - 1;
  DWORD prio = priority[nice + NZERO];
  if (!wincap.has_extended_priority_class ()
      && (prio == BELOW_NORMAL_PRIORITY_CLASS
	  || prio == ABOVE_NORMAL_PRIORITY_CLASS))
    prio = NORMAL_PRIORITY_CLASS;
  return prio;
}

#undef CreatePipe
bool
create_pipe (PHANDLE hr,PHANDLE hw, LPSECURITY_ATTRIBUTES sa, DWORD n)
{
  for (int i = 0; i < 10; i++)
    if (CreatePipe (hr, hw, sa, n))
      return true;
    else if (GetLastError () == ERROR_PIPE_BUSY && i < 9)
      Sleep (10);
    else
      break;
  return false;
}

/* 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. */

void
backslashify (const char *src, char *dst, bool trailing_slash_p)
{
  const char *start = src;

  while (*src)
    {
      if (*src == '/')
	*dst++ = '\\';
      else
	*dst++ = *src;
      ++src;
    }
  if (trailing_slash_p
      && src > start
      && !isdirsep (src[-1]))
    *dst++ = '\\';
  *dst++ = 0;
}

/* slashify: Convert all back slashes in src path to forward slashes
   in dst path.  Add a trailing slash to dst when trailing_slash_p arg
   is set to 1. */

void
slashify (const char *src, char *dst, bool trailing_slash_p)
{
  const char *start = src;

  while (*src)
    {
      if (*src == '\\')
	*dst++ = '/';
      else
	*dst++ = *src;
      ++src;
    }
  if (trailing_slash_p
      && src > start
      && !isdirsep (src[-1]))
    *dst++ = '/';
  *dst++ = 0;
}