/* mkgroup.c:

   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 <errno.h>
#include <ctype.h>
#include <stdlib.h>
#include <wchar.h>
#include <wctype.h>
#include <locale.h>
#include <stdio.h>
#include <unistd.h>
#include <inttypes.h>
#include <getopt.h>
#include <io.h>
#include <grp.h>
#include <sys/fcntl.h>
#include <sys/cygwin.h>
#include <cygwin/version.h>
#include <windows.h>
#include <lm.h>
#include <wininet.h>
#include <iptypes.h>
#include <ntsecapi.h>
#include <ntdef.h>

#define print_win_error(x) _print_win_error(x, __LINE__)

SID_IDENTIFIER_AUTHORITY sid_world_auth = {SECURITY_WORLD_SID_AUTHORITY};
SID_IDENTIFIER_AUTHORITY sid_nt_auth = {SECURITY_NT_AUTHORITY};

#ifndef min
#define min(a,b) (((a)<(b))?(a):(b))
#endif

typedef struct
{
  char *str;
  BOOL domain;
  BOOL with_dom;
} domlist_t;

static void
_print_win_error (DWORD code, int line)
{
  char buf[4096];

  if (FormatMessage (FORMAT_MESSAGE_FROM_SYSTEM
      | FORMAT_MESSAGE_IGNORE_INSERTS,
      NULL,
      code,
      MAKELANGID (LANG_NEUTRAL, SUBLANG_DEFAULT),
      (LPTSTR) buf, sizeof (buf), NULL))
    fprintf (stderr, "mkgroup (%d): [%" PRIu32 "] %s",
	     line, (unsigned int) code, buf);
  else
    fprintf (stderr, "mkgroup (%d): error %" PRIu32 ,
	     line, (unsigned int) code);
}

static char *
put_sid (PSID psid)
{
  static char s[512];
  char t[32];
  DWORD i;

  strcpy (s, "S-1-");
  sprintf(t, "%u", GetSidIdentifierAuthority (psid)->Value[5]);
  strcat (s, t);
  for (i = 0; i < *GetSidSubAuthorityCount (psid); ++i)
    {
      sprintf(t, "-%" PRIu32 , (unsigned int) *GetSidSubAuthority (psid, i));
      strcat (s, t);
    }
  return s;
}

typedef struct {
  BYTE  Revision;
  BYTE  SubAuthorityCount;
  SID_IDENTIFIER_AUTHORITY IdentifierAuthority;
  DWORD SubAuthority[8];
} DBGSID, *PDBGSID;

#define MAX_BUILTIN_SIDS 100	/* Should be enough for the forseable future. */
DBGSID builtin_sid_list[MAX_BUILTIN_SIDS];
DWORD builtin_sid_cnt;

typedef struct {
  PSID psid;
  int buffer[10];
} sidbuf;

static sidbuf curr_pgrp;
static BOOL got_curr_pgrp = FALSE;

static void
fetch_current_pgrp_sid ()
{
  DWORD len;
  HANDLE ptok;

  if (!OpenProcessToken (GetCurrentProcess (), TOKEN_QUERY, &ptok)
      || !GetTokenInformation (ptok, TokenPrimaryGroup, &curr_pgrp,
			       sizeof curr_pgrp, &len)
      || !CloseHandle (ptok))
    {
      print_win_error (GetLastError ());
      return;
    }
}

static void
enum_unix_groups (domlist_t *mach, const char *sep, DWORD id_offset,
		  char *unix_grp_list)
{
  WCHAR machine[INTERNET_MAX_HOST_NAME_LENGTH + 1];
  SID_IDENTIFIER_AUTHORITY auth = { { 0, 0, 0, 0, 0, 22 } };
  char *gstr, *grp_list;
  WCHAR grp[GNLEN + sizeof ("Unix Group\\") + 1];
  WCHAR dom[MAX_DOMAIN_NAME_LEN + 1];
  DWORD glen, dlen, sidlen;
  PSID psid;
  PSID numeric_psid;
  char psid_buffer[SECURITY_MAX_SID_SIZE];
  SID_NAME_USE acc_type;

  int ret = mbstowcs (machine, mach->str, INTERNET_MAX_HOST_NAME_LENGTH + 1);
  if (ret < 1 || ret >= INTERNET_MAX_HOST_NAME_LENGTH + 1)
    {
      fprintf (stderr, "%s: Invalid machine name '%s'.  Skipping...\n",
	       program_invocation_short_name, mach->str);
      return;
    }

  if (!AllocateAndInitializeSid (&auth, 2, 2, 0, 0, 0, 0, 0, 0, 0,
				 &numeric_psid))
    return;

  if (!(grp_list = strdup (unix_grp_list)))
    {
      FreeSid (numeric_psid);
      return;
    }

  for (gstr = strtok (grp_list, ","); gstr; gstr = strtok (NULL, ","))
    {
      if (!isdigit ((unsigned char) gstr[0]) && gstr[0] != '-')
	{
	  PWCHAR p = wcpcpy (grp, L"Unix Group\\");
	  ret = mbstowcs (p, gstr, GNLEN + 1);
	  if (ret < 1 || ret >= GNLEN + 1)
	    {
	      fprintf (stderr, "%s: Invalid group name '%s'.  Skipping...\n",
		       program_invocation_short_name, gstr);
	      continue;
	    }
	  psid = (PSID) psid_buffer;
	  sidlen = SECURITY_MAX_SID_SIZE;
	  dlen = MAX_DOMAIN_NAME_LEN + 1;
	  if (LookupAccountNameW (machine, grp, psid, &sidlen,
				  dom, &dlen, &acc_type))
	    printf ("%s%s%ls:%s:%" PRIu32 ":\n",
		    "Unix_Group",
		    sep,
		    p,
		    put_sid (psid),
		    (unsigned int) (id_offset +
		    *GetSidSubAuthority (psid,
					 *GetSidSubAuthorityCount(psid) - 1)));
	}
      else
	{
	  DWORD start, stop;
	  char *p = gstr;
	  if (*p == '-')
	    start = 0;
	  else
	    start = strtol (p, &p, 10);
	  if (!*p)
	    stop = start;
	  else if (*p++ != '-' || !isdigit ((unsigned char) *p)
		   || (stop = strtol (p, &p, 10)) < start || *p)
	    {
	      fprintf (stderr, "%s: Malformed unix group list entry '%s'.  "
			       "Skipping...\n",
			       program_invocation_short_name, gstr);
	      continue;
	    }
	  for (; start <= stop; ++ start)
	    {
	      psid = numeric_psid;
	      *GetSidSubAuthority (psid, *GetSidSubAuthorityCount(psid) - 1)
	      = start;
	      glen = GNLEN + 1;
	      dlen = MAX_DOMAIN_NAME_LEN + 1;
	      if (LookupAccountSidW (machine, psid, grp, &glen,
				     dom, &dlen, &acc_type)
		  && !iswdigit (grp[0]))
		printf ("%s%s%ls:%s:%" PRIu32 ":\n",
			"Unix_Group",
			sep,
			grp,
			put_sid (psid),
			(unsigned int) (id_offset + start));
	    }
	}
    }

  free (grp_list);
  FreeSid (numeric_psid);
}

static int
enum_local_groups (domlist_t *mach, const char *sep,
		   DWORD id_offset, char *disp_groupname, int print_builtin,
		   int print_current)
{
  WCHAR machine[INTERNET_MAX_HOST_NAME_LENGTH + 1];
  LOCALGROUP_INFO_0 *buffer;
  DWORD entriesread = 0;
  DWORD totalentries = 0;
  DWORD_PTR resume_handle = 0;
  WCHAR gname[GNLEN + 1];
  DWORD rc;

  int ret = mbstowcs (machine, mach->str, INTERNET_MAX_HOST_NAME_LENGTH + 1);
  if (ret < 1 || ret >= INTERNET_MAX_HOST_NAME_LENGTH + 1)
    {
      fprintf (stderr, "%s: Invalid machine name '%s'.  Skipping...\n",
	       program_invocation_short_name, mach->str);
      return 1;
    }

  do
    {
      DWORD i;

      if (disp_groupname)
	{
	  mbstowcs (gname, disp_groupname, GNLEN + 1);
	  rc = NetLocalGroupGetInfo (machine, gname, 0, (void *) &buffer);
	  if (rc == ERROR_SUCCESS)
	    entriesread = 1;
	  /* Allow further searching for the group and avoid annoying
	     error messages just because the group is not a local group or
	     the group hasn't been found. */
	  else if (rc == ERROR_NO_SUCH_ALIAS || rc == NERR_GroupNotFound)
	    return 0;
	}
      else
	rc = NetLocalGroupEnum (machine, 0, (void *) &buffer,
				MAX_PREFERRED_LENGTH, &entriesread,
				&totalentries, &resume_handle);
      switch (rc)
	{
	case ERROR_ACCESS_DENIED:
	  print_win_error (rc);
	  return 1;

	case ERROR_MORE_DATA:
	case ERROR_SUCCESS:
	  break;

	default:
	  print_win_error (rc);
	  return 1;
	}

      for (i = 0; i < entriesread; i++)
	{
	  WCHAR domain_name[MAX_DOMAIN_NAME_LEN + 1];
	  DWORD domname_len = MAX_DOMAIN_NAME_LEN + 1;
	  char psid_buffer[SECURITY_MAX_SID_SIZE];
	  PSID psid = (PSID) psid_buffer;
	  DWORD sid_length = SECURITY_MAX_SID_SIZE;
	  DWORD gid;
	  SID_NAME_USE acc_type;
	  PDBGSID pdsid;
	  BOOL is_builtin = FALSE;

	  if (!LookupAccountNameW (machine, buffer[i].lgrpi0_name, psid,
				   &sid_length, domain_name, &domname_len,
				   &acc_type))
	    {
	      print_win_error (GetLastError ());
	      fprintf (stderr, " (%ls)\n", buffer[i].lgrpi0_name);
	      continue;
	    }
	  else if (acc_type == SidTypeDomain)
	    {
	      WCHAR domname[MAX_DOMAIN_NAME_LEN + GNLEN + 2];
	      PWCHAR p;

	      p = wcpcpy (domname, domain_name);
	      p = wcpcpy (p, L"\\");
	      p = wcpncpy (p, buffer[i].lgrpi0_name, GNLEN);
	      *p = L'\0';
	      sid_length = SECURITY_MAX_SID_SIZE;
	      domname_len = MAX_DOMAIN_NAME_LEN + 1;
	      if (!LookupAccountNameW (machine, domname,
				       psid, &sid_length,
				       domain_name, &domname_len,
				       &acc_type))
		{
		  print_win_error (GetLastError ());
		  fprintf(stderr, " (%ls)\n", domname);
		  continue;
		}
	    }

	  /* Store all local SIDs with prefix "S-1-5-32-" and check if it
	     has been printed already.  This allows to get all builtin
	     groups exactly once and not once per domain. */
	  pdsid = (PDBGSID) psid;
	  if (pdsid->IdentifierAuthority.Value[5] == sid_nt_auth.Value[5]
	      && pdsid->SubAuthority[0] == SECURITY_BUILTIN_DOMAIN_RID)
	    {
	      int b;

	      if (!print_builtin)
		goto skip_group;
	      is_builtin = TRUE;
	      if (builtin_sid_cnt)
		for (b = 0; b < builtin_sid_cnt; b++)
		  if (EqualSid (&builtin_sid_list[b], psid))
		    goto skip_group;
	      if (builtin_sid_cnt < MAX_BUILTIN_SIDS)
		CopySid (sizeof (DBGSID), &builtin_sid_list[builtin_sid_cnt++],
			 psid);
	    }
	  if (!print_current)
	    /* fall through */;
	  else if (EqualSid (curr_pgrp.psid, psid))
	    got_curr_pgrp = TRUE;

	  gid = *GetSidSubAuthority (psid, *GetSidSubAuthorityCount(psid) - 1);
	  printf ("%ls%s%ls:%s:%" PRIu32 ":\n",
		  mach->with_dom && !is_builtin ? domain_name : L"",
		  mach->with_dom && !is_builtin ? sep : "",
		  buffer[i].lgrpi0_name,
		  put_sid (psid),
		  (unsigned int) (gid + (is_builtin ? 0 : id_offset)));
skip_group:
	  ;
	}

      NetApiBufferFree (buffer);

    }
  while (rc == ERROR_MORE_DATA);

  /* Return 1 if the single group we're looking for has been found here to
     avoid calling enum_groups for the same group, thus avoiding a spurious
     error message "group name could not be found" in enum_groups. */
  return disp_groupname && entriesread ? 1 : 0;
}

static void
enum_groups (domlist_t *mach, const char *sep, DWORD id_offset,
	     char *disp_groupname, int print_current)
{
  WCHAR machine[INTERNET_MAX_HOST_NAME_LENGTH + 1];
  GROUP_INFO_2 *buffer;
  DWORD entriesread = 0;
  DWORD totalentries = 0;
  DWORD_PTR resume_handle = 0;
  WCHAR gname[GNLEN + 1];
  DWORD rc;

  int ret = mbstowcs (machine, mach->str, INTERNET_MAX_HOST_NAME_LENGTH + 1);
  if (ret < 1 || ret >= INTERNET_MAX_HOST_NAME_LENGTH + 1)
    {
      fprintf (stderr, "%s: Invalid machine name '%s'.  Skipping...\n",
	       program_invocation_short_name, mach->str);
      return;
    }

  do
    {
      DWORD i;

      if (disp_groupname != NULL)
	{
	  mbstowcs (gname, disp_groupname, GNLEN + 1);
	  rc = NetGroupGetInfo (machine, (LPWSTR) & gname, 2, (void *) &buffer);
	  entriesread=1;
	  /* Avoid annoying error messages just because the group hasn't been
	     found. */
	  if (rc == NERR_GroupNotFound)
	    return;
	}
      else
	rc = NetGroupEnum (machine, 2, (void *) & buffer, MAX_PREFERRED_LENGTH,
			   &entriesread, &totalentries, &resume_handle);
      switch (rc)
	{
	case ERROR_ACCESS_DENIED:
	  print_win_error (rc);
	  return;

	case ERROR_MORE_DATA:
	case ERROR_SUCCESS:
	  break;

	default:
	  print_win_error (rc);
	  return;
	}

      for (i = 0; i < entriesread; i++)
	{
	  WCHAR domain_name[MAX_DOMAIN_NAME_LEN + 1];
	  DWORD domname_len = MAX_DOMAIN_NAME_LEN + 1;
	  char psid_buffer[SECURITY_MAX_SID_SIZE];
	  PSID psid = (PSID) psid_buffer;
	  DWORD sid_length = SECURITY_MAX_SID_SIZE;
	  SID_NAME_USE acc_type;

	  int gid = buffer[i].grpi2_group_id;
	  if (!LookupAccountNameW (machine, buffer[i].grpi2_name,
				   psid, &sid_length,
				   domain_name, &domname_len,
				   &acc_type))
	    {
	      print_win_error (GetLastError ());
	      fprintf(stderr, " (%ls)\n", buffer[i].grpi2_name);
	      continue;
	    }
	  else if (acc_type == SidTypeDomain)
	    {
	      WCHAR domname[MAX_DOMAIN_NAME_LEN + GNLEN + 2];
	      PWCHAR p;

	      p = wcpcpy (domname, machine);
	      p = wcpcpy (p, L"\\");
	      p = wcpncpy (p, buffer[i].grpi2_name, GNLEN);
	      *p = L'\0';
	      sid_length = SECURITY_MAX_SID_SIZE;
	      domname_len = MAX_DOMAIN_NAME_LEN + 1;
	      if (!LookupAccountNameW (machine, domname, psid, &sid_length,
				       domain_name, &domname_len, &acc_type))
		{
		  print_win_error (GetLastError ());
		  fprintf(stderr, " (%ls)\n", domname);
		  continue;
		}
	    }
	  if (!print_current)
	    /* fall through */;
	  else if (EqualSid (curr_pgrp.psid, psid))
	    got_curr_pgrp = TRUE;

	  printf ("%ls%s%ls:%s:%" PRIu32 ":\n",
		  mach->with_dom ? domain_name : L"",
		  mach->with_dom ? sep : "",
		  buffer[i].grpi2_name,
		  put_sid (psid),
		  (unsigned int) (id_offset + gid));
	}

      NetApiBufferFree (buffer);

    }
  while (rc == ERROR_MORE_DATA);
}

static int __attribute__ ((__noreturn__))
usage (FILE * stream)
{
  fprintf (stream,
"Usage: %s [OPTION]...\n"
"\n"
"Write /etc/group-like output to stdout\n"
"\n"
"Don't use this command to generate a local /etc/group file, unless you\n"
"really need one.  See the Cygwin User's Guide for more information.\n"
"\n"
"Options:\n"
"\n"
"   -l,--local [machine]    Print local group accounts of \"machine\",\n"
"                           from local machine if no machine specified.\n"
"                           Automatically adding machine prefix for local\n"
"                           machine depends on settings in /etc/nsswitch.conf.\n"
"   -L,--Local machine      Ditto, but generate groupname with machine prefix.\n"
"   -d,--domain [domain]    Print domain groups,\n"
"                           from current domain if no domain specified.\n"
"   -c,--current            Print current group.\n"
"   -S,--separator char     For -L use character char as domain\\group\n"
"                           separator in groupname instead of default '%s'.\n"
"   -o,--id-offset offset   Change the default offset (0x10000) added to gids\n"
"                           of foreign local machine accounts.  Use with -l/-L.\n"
"   -g,--group groupname    Only return information for the specified group.\n"
"                           One of -l, -d must be specified, too.\n"
"   -b,--no-builtin         Don't print BUILTIN groups.\n"
"   -U,--unix grouplist     Print UNIX groups when using -l on a UNIX Samba\n"
"                           server.  Grouplist is a comma-separated list of\n"
"                           groupnames or gid ranges (root,-25,50-100).\n"
"                           Enumerating large ranges can take a long time!\n"
"   -h,--help               Print this message.\n"
"   -v,--version            Print version information and exit.\n"
"\n"
"Default is to print local groups on stand-alone machines, plus domain\n"
"groups on domain controllers and domain member machines.\n"
"\n", program_invocation_short_name,
      (const char *) cygwin_internal (CW_GETNSSSEP));
  exit (0);
}

struct option longopts[] = {
  {"no-builtin", no_argument, NULL, 'b'},
  {"current", no_argument, NULL, 'c'},
  {"Current", no_argument, NULL, 'C'},
  {"domain", optional_argument, NULL, 'd'},
  {"Domain", optional_argument, NULL, 'D'},
  {"group", required_argument, NULL, 'g'},
  {"help", no_argument, NULL, 'h'},
  {"local", optional_argument, NULL, 'l'},
  {"Local", optional_argument, NULL, 'L'},
  {"id-offset", required_argument, NULL, 'o'},
  {"no-sids", no_argument, NULL, 's'},
  {"separator", required_argument, NULL, 'S'},
  {"users", no_argument, NULL, 'u'},
  {"unix", required_argument, NULL, 'U'},
  {"version", no_argument, NULL, 'V'},
  {0, no_argument, NULL, 0}
};

static char opts[] = "bcCd::D::g:hl::L::o:sS:uU:V";

static void
print_version ()
{
  printf ("mkgroup (cygwin) %d.%d.%d\n"
	  "Group File Generator\n"
	  "Copyright (C) 1997 - %s Cygwin Authors\n"
	  "This is free software; see the source for copying conditions.  There is NO\n"
	  "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n",
	  CYGWIN_VERSION_DLL_MAJOR / 1000,
	  CYGWIN_VERSION_DLL_MAJOR % 1000,
	  CYGWIN_VERSION_DLL_MINOR,
	  strrchr (__DATE__, ' ') + 1);
}

int
main (int argc, char **argv)
{
  int print_domlist = 0;
  domlist_t domlist[32];
  char cname[1024];
  char *opt, *p;
  int print_current = 0;
  int print_builtin = 1;
  char *print_unix = NULL;
  const char *sep_char = (const char *) cygwin_internal (CW_GETNSSSEP);
  DWORD id_offset = 0x10000, off;
  int c, i;
  char *disp_groupname = NULL;
  int optional_args = 0;
  uintptr_t nss_src = cygwin_internal (CW_GETNSS_GRP_SRC);

  if (!isatty (1))
    setmode (1, O_BINARY);

  /* Use locale from environment.  If not set or set to "C", use UTF-8. */
  setlocale (LC_CTYPE, "");
  if (!strcmp (setlocale (LC_CTYPE, NULL), "C"))
    setlocale (LC_CTYPE, "en_US.UTF-8");
  fetch_current_pgrp_sid ();

  if (argc == 1)
    {
      int enums = ENUM_PRIMARY | ENUM_LOCAL | ENUM_BUILTIN;
      uintptr_t ticket = cygwin_internal (CW_SETENT, TRUE, enums, NULL);
      if (ticket)
	{
	  struct group *grp;

	  while ((grp = (struct group *) cygwin_internal (CW_GETENT, TRUE,
							  ticket)))
	    printf ("%s:%s:%u:\n", grp->gr_name, grp->gr_passwd, grp->gr_gid);
	  cygwin_internal (CW_ENDENT, TRUE, ticket);
	}
      return 0;
    }

  unsetenv ("POSIXLY_CORRECT"); /* To get optional arg processing right. */
  while ((c = getopt_long (argc, argv, opts, longopts, NULL)) != EOF)
    switch (c)
      {
      case 'd':
      case 'D':
      case 'l':
      case 'L':
	if (print_domlist >= 32)
	  {
	    fprintf (stderr, "%s: Can not enumerate from more than 32 "
			     "domains and machines.\n",
			     program_invocation_short_name);
	    return 1;
	  }
	domlist[print_domlist].domain = (c == 'd' || c == 'D');
	opt = optarg ?:
	      argv[optind] && argv[optind][0] != '-' ? argv[optind] : NULL;
	if (argv[optind] && opt == argv[optind])
	  ++optional_args;
	for (i = 0; i < print_domlist; ++i)
	  if (domlist[i].domain == domlist[print_domlist].domain
	      && ((!domlist[i].str && !opt)
		  || (domlist[i].str && opt
		      && (off = strlen (domlist[i].str))
		      && !strncmp (domlist[i].str, opt, off)
		      && (!opt[off] || opt[off] == ','))))
	    {
	      fprintf (stderr, "%s: Duplicate %s '%s'.  Skipping...\n",
		       program_invocation_short_name,
		       domlist[i].domain ? "domain" : "machine",
		       domlist[i].str);
	      break;
	    }
	domlist[print_domlist].str = opt;
	if (opt && (p = strchr (opt, ',')))
	  {
	    if (p == opt)
	      {
		fprintf (stderr, "%s: Malformed machine string '%s'.  "
			 "Skipping...\n", program_invocation_short_name, opt);
		break;
	      }
	    *p = '\0';
	  }
	if (c == 'l' || c == 'L')
	  {
	    DWORD csize = sizeof cname;

	    domlist[print_domlist].with_dom = (c == 'L');
	    if (!opt)
	      {
		/* If the system uses /etc/group exclusively as account DB,
		   create local group names the old fashioned way. */
		if (nss_src == NSS_SRC_FILES)
		  {
		    GetComputerNameExA (ComputerNameNetBIOS, cname, &csize);
		    domlist[print_domlist].str = cname;
		  }
	      }
	    else if (nss_src != NSS_SRC_FILES)
	      {
		/* If the system uses Windows account DBs, check if machine
		   name is local machine.  If so, remove the domain name to
		   enforce system naming convention. */
		if (GetComputerNameExA (strchr (opt, '.')
					? ComputerNameDnsFullyQualified
					: ComputerNameNetBIOS,
					cname, &csize)
		    && strcasecmp (opt, cname) == 0)
		  domlist[print_domlist].str = NULL;
	      }
	  }
	++print_domlist;
	break;
      case 'S':
	sep_char = optarg;
	if (strlen (sep_char) > 1)
	  {
	    fprintf (stderr, "%s: Only one ASCII character allowed as "
			     "domain\\user separator character.\n",
			     program_invocation_short_name);
	    return 1;
	  }
	if (*sep_char == ':')
	  {
	    fprintf (stderr, "%s: Colon not allowed as domain\\user separator "
			     "character.\n", program_invocation_short_name);
	    return 1;
	  }
	break;
      case 'U':
	print_unix = optarg;
	break;
      case 'c':
      case 'C':
	print_current = 1;
	break;
      case 'o':
	id_offset = strtol (optarg, NULL, 10);
	break;
      case 'b':
	print_builtin = 0;
	break;
      case 's':
	break;
      case 'u':
	break;
      case 'g':
	disp_groupname = optarg;
	break;
      case 'h':
	usage (stdout);
      case 'V':
	print_version ();
	return 0;
      default:
	fprintf (stderr, "Try `%s --help' for more information.\n", argv[0]);
	return 1;
      }

  optind += optional_args;
  if (argv[optind])
    {
      fprintf (stderr,
	       "mkgroup: non-option command line argument `%s' is not allowed.\n"
	       "Try `mkgroup --help' for more information.\n", argv[optind]);
      exit (1);
    }

  struct group *pgrp = NULL;
  if (print_current)
    pgrp = (struct group *) cygwin_internal (CW_GETGRSID, TRUE, curr_pgrp.psid);

  int enums = ENUM_NONE;
  WCHAR tdoms[print_domlist * 258];
  PWCHAR t = tdoms;
  if (!disp_groupname && print_builtin && print_domlist)
    enums |= ENUM_BUILTIN;
  for (i = 0; i < print_domlist; ++i)
    {
      if (domlist[i].domain)
	{
	  if (domlist[i].str)
	    {
	      enums |= ENUM_TDOMS;
	      t += mbstowcs (t, domlist[i].str, 257);
	      *t++ = L'\0';
	    }
	  else
	    enums |= ENUM_PRIMARY;
	}
      else if (!domlist[i].str)
	enums |= ENUM_LOCAL;
    }
  if (t > tdoms)
    *t++ = L'\0';
  if (enums)
    {
      uintptr_t ticket = cygwin_internal (CW_SETENT, TRUE, enums,
					  t > tdoms ? tdoms : NULL);
      if (ticket)
	{
	  struct group *grp;
	  const char *nss_sep = (const char *) cygwin_internal (CW_GETNSSSEP);

	  while ((grp = (struct group *)
			cygwin_internal (CW_GETENT, TRUE, ticket)))
	    {
	      if (disp_groupname
		  && strcasecmp (disp_groupname, grp->gr_name) != 0
		  && (!(p = strchr (grp->gr_name, nss_sep[0]))
		      || strcasecmp (disp_groupname, p + 1) != 0))
		continue;
	      printf ("%s:%s:%u:\n", grp->gr_name, grp->gr_passwd,
				     grp->gr_gid);
	      if (pgrp && !strcmp (grp->gr_passwd, pgrp->gr_passwd))
		got_curr_pgrp = TRUE;
	    }
	  cygwin_internal (CW_ENDENT, TRUE, ticket);
	}
    }

  if (print_current && !got_curr_pgrp)
    printf ("%s:%s:%u:\n", pgrp->gr_name, pgrp->gr_passwd, pgrp->gr_gid);

  off = 0xfd000000;
  for (i = 0; i < print_domlist; ++i)
    {
      if (domlist[i].domain || !domlist[i].str)
	continue;
      if (!enum_local_groups (domlist + i, sep_char,
			      (nss_src == NSS_SRC_FILES) ? 0x30000 : off,
			      disp_groupname, print_builtin, print_current))
	{
	  enum_groups (domlist + i, sep_char,
		       (nss_src == NSS_SRC_FILES) ? 0x30000 : off,
		       disp_groupname, print_current);
	  if (!domlist[i].domain && domlist[i].str && print_unix)
	    enum_unix_groups (domlist + i, sep_char, 0xff000000, print_unix);
	  off += id_offset;
	}
    }

  return 0;
}
