/* path.h: path data structures

   Copyright 1996, 1997, 1998, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
   2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015 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 "devices.h"
#include "mount.h"
#include "cygheap_malloc.h"
#include "nfs.h"

#include <sys/ioctl.h>
#include <fcntl.h>
#include <alloca.h>

extern inline bool
has_attribute (DWORD attributes, DWORD attribs_to_test)
{
  return attributes != INVALID_FILE_ATTRIBUTES
	 && (attributes & attribs_to_test);
}

enum executable_states
{
  is_executable,
  dont_care_if_executable,
  not_executable = dont_care_if_executable,
  dont_know_if_executable
};

struct suffix_info
{
  const char *name;
  int addon;
  suffix_info (const char *s, int addit = 0): name (s), addon (addit) {}
};

extern suffix_info stat_suffixes[];

enum pathconv_arg
{
  PC_SYM_FOLLOW		= 0x0001,
  PC_SYM_NOFOLLOW	= 0x0002,
  PC_SYM_NOFOLLOW_REP	= 0x0004,
  PC_SYM_CONTENTS	= 0x0008,
  PC_NOFULL		= 0x0010,
  PC_NULLEMPTY		= 0x0020,
  PC_POSIX		= 0x0080,
  PC_NOWARN		= 0x0100,
  PC_OPEN		= 0x0200,	/* use open semantics */
  PC_CTTY		= 0x0400,	/* could later be used as ctty */
  PC_KEEP_HANDLE	= 0x00400000,
  PC_NO_ACCESS_CHECK	= 0x00800000
};

#define PC_NONULLEMPTY -1

#include "sys/mount.h"

enum path_types
{
  PATH_NOTHING		= 0,
  PATH_SYMLINK		= MOUNT_SYMLINK,
  PATH_BINARY		= MOUNT_BINARY,
  PATH_EXEC		= MOUNT_EXEC,
  PATH_NOTEXEC		= MOUNT_NOTEXEC,
  PATH_CYGWIN_EXEC	= MOUNT_CYGWIN_EXEC,
  PATH_SPARSE		= MOUNT_SPARSE,
  PATH_RO		= MOUNT_RO,
  PATH_NOACL		= MOUNT_NOACL,
  PATH_NOPOSIX		= MOUNT_NOPOSIX,
  PATH_DOS		= MOUNT_DOS,
  PATH_IHASH		= MOUNT_IHASH,
  PATH_ALL_EXEC		= (PATH_CYGWIN_EXEC | PATH_EXEC),
  PATH_NO_ACCESS_CHECK	= PC_NO_ACCESS_CHECK,
  PATH_CTTY		= 0x00400000,	/* could later be used as ctty */
  PATH_OPEN		= 0x00800000,	/* use open semantics */
  					/* FIXME?  PATH_OPEN collides with
					   PATH_NO_ACCESS_CHECK, but it looks
					   like they are never used together. */
  PATH_LNK		= 0x01000000,
  PATH_TEXT		= 0x02000000,
  PATH_REP		= 0x04000000,
  PATH_HAS_SYMLINKS	= 0x10000000,
  PATH_SOCKET		= 0x40000000
};

class symlink_info;

class path_conv_handle
{
  HANDLE      hdl;
  union {
    FILE_ALL_INFORMATION _fai;
    /* For NFS. */
    fattr3 _fattr3;
  } attribs;
public:
  path_conv_handle () : hdl (NULL) {}
  inline void set (HANDLE h) { hdl = h; }
  inline void close ()
  {
    if (hdl)
      CloseHandle (hdl);
    set (NULL);
  }
  inline void dup (const path_conv_handle &pch)
  {
    if (!DuplicateHandle (GetCurrentProcess (), pch.handle (),
			  GetCurrentProcess (), &hdl,
			  0, TRUE, DUPLICATE_SAME_ACCESS))
      hdl = NULL;
  }
  inline HANDLE handle () const { return hdl; }
  inline PFILE_ALL_INFORMATION fai ()
  { return (PFILE_ALL_INFORMATION) &attribs._fai; }
  inline struct fattr3 *nfsattr ()
  { return (struct fattr3 *) &attribs._fattr3; }
};

class path_conv
{
  DWORD fileattr;
  ULONG caseinsensitive;
  fs_info fs;
  PWCHAR wide_path;
  UNICODE_STRING uni_path;
  void add_ext_from_sym (symlink_info&);
  DWORD symlink_length;
  const char *path;
  unsigned path_flags;
  const char *suffix;
  const char *posix_path;
  path_conv_handle conv_handle;
 public:
  int error;
  device dev;

  const char *known_suffix () { return suffix; }
  bool isremote () const {return fs.is_remote_drive ();}
  ULONG objcaseinsensitive () const {return caseinsensitive;}
  bool has_acls () const {return !(path_flags & PATH_NOACL) && fs.has_acls (); }
  bool hasgood_inode () const {return !(path_flags & PATH_IHASH); }
  bool isgood_inode (ino_t ino) const;
  bool support_sparse () const
  {
    return (path_flags & PATH_SPARSE)
	   && (fs_flags () & FILE_SUPPORTS_SPARSE_FILES);
  }
  int has_symlinks () const {return path_flags & PATH_HAS_SYMLINKS;}
  int has_dos_filenames_only () const {return path_flags & PATH_DOS;}
  int has_buggy_open () const {return fs.has_buggy_open ();}
  int has_buggy_reopen () const {return fs.has_buggy_reopen ();}
  int has_buggy_fileid_dirinfo () const {return fs.has_buggy_fileid_dirinfo ();}
  int has_buggy_basic_info () const {return fs.has_buggy_basic_info ();}
  int has_broken_fnoi () const {return fs.has_broken_fnoi ();}
  int binmode () const
  {
    if (path_flags & PATH_BINARY)
      return O_BINARY;
    if (path_flags & PATH_TEXT)
      return O_TEXT;
    return 0;
  }
  int issymlink () const {return path_flags & PATH_SYMLINK;}
  int is_lnk_symlink () const {return path_flags & PATH_LNK;}
  int is_rep_symlink () const {return path_flags & PATH_REP;}
  int isdevice () const {return dev.not_device (FH_FS) && dev.not_device (FH_FIFO);}
  int isfifo () const {return dev.is_device (FH_FIFO);}
  int isspecial () const {return dev.not_device (FH_FS);}
  int iscygdrive () const {return dev.is_device (FH_CYGDRIVE);}
  int is_auto_device () const {return isdevice () && !is_fs_special ();}
  int is_fs_device () const {return isdevice () && is_fs_special ();}
  int is_fs_special () const {return dev.is_fs_special ();}
  int is_lnk_special () const {return is_fs_device () || isfifo () || is_lnk_symlink ();}
  int issocket () const {return dev.is_device (FH_UNIX);}
  int iscygexec () const {return path_flags & PATH_CYGWIN_EXEC;}
  int isopen () const {return path_flags & PATH_OPEN;}
  int isctty_capable () const {return path_flags & PATH_CTTY;}
  void set_cygexec (bool isset)
  {
    if (isset)
      path_flags |= PATH_CYGWIN_EXEC;
    else
      path_flags &= ~PATH_CYGWIN_EXEC;
  }
  void set_cygexec (void *target)
  {
    if (target)
      path_flags |= PATH_CYGWIN_EXEC;
    else
      path_flags &= ~PATH_CYGWIN_EXEC;
  }
  bool isro () const {return !!(path_flags & PATH_RO);}
  bool exists () const {return fileattr != INVALID_FILE_ATTRIBUTES;}
  bool has_attribute (DWORD x) const {return exists () && (fileattr & x);}
  int isdir () const {return has_attribute (FILE_ATTRIBUTE_DIRECTORY);}
  executable_states exec_state ()
  {
    extern int _check_for_executable;
    if (path_flags & PATH_ALL_EXEC)
      return is_executable;
    if (path_flags & PATH_NOTEXEC)
      return not_executable;
    if (!_check_for_executable)
      return dont_care_if_executable;
    return dont_know_if_executable;
  }

  void set_symlink (DWORD n) {path_flags |= PATH_SYMLINK; symlink_length = n;}
  void set_has_symlinks () {path_flags |= PATH_HAS_SYMLINKS;}
  void set_exec (int x = 1) {path_flags |= x ? PATH_EXEC : PATH_NOTEXEC;}

  void __reg3 check (const UNICODE_STRING *upath, unsigned opt = PC_SYM_FOLLOW,
	      const suffix_info *suffixes = NULL);
  void __reg3 check (const char *src, unsigned opt = PC_SYM_FOLLOW,
	      const suffix_info *suffixes = NULL);

  path_conv (const device& in_dev)
  : fileattr (INVALID_FILE_ATTRIBUTES), wide_path (NULL), path (NULL),
    path_flags (0), suffix (NULL), posix_path (NULL), error (0),
    dev (in_dev)
  {
    set_path (in_dev.native);
  }

  path_conv (int, const char *src, unsigned opt = PC_SYM_FOLLOW,
	     const suffix_info *suffixes = NULL)
  : fileattr (INVALID_FILE_ATTRIBUTES), wide_path (NULL), path (NULL),
    path_flags (0), suffix (NULL), posix_path (NULL), error (0)
  {
    check (src, opt, suffixes);
  }

  path_conv (const UNICODE_STRING *src, unsigned opt = PC_SYM_FOLLOW,
	     const suffix_info *suffixes = NULL)
  : fileattr (INVALID_FILE_ATTRIBUTES), wide_path (NULL), path (NULL),
    path_flags (0), suffix (NULL), posix_path (NULL), error (0)
  {
    check (src, opt | PC_NULLEMPTY, suffixes);
  }

  path_conv (const char *src, unsigned opt = PC_SYM_FOLLOW,
	     const suffix_info *suffixes = NULL)
  : fileattr (INVALID_FILE_ATTRIBUTES), wide_path (NULL), path (NULL),
    path_flags (0), suffix (NULL), posix_path (NULL), error (0)
  {
    check (src, opt | PC_NULLEMPTY, suffixes);
  }

  path_conv ()
  : fileattr (INVALID_FILE_ATTRIBUTES), wide_path (NULL), path (NULL),
    path_flags (0), suffix (NULL), posix_path (NULL), error (0)
  {}

  ~path_conv ();
  inline const char *get_win32 () const { return path; }
  void set_nt_native_path (PUNICODE_STRING);
  PUNICODE_STRING get_nt_native_path ();
  inline POBJECT_ATTRIBUTES get_object_attr (OBJECT_ATTRIBUTES &attr,
					     SECURITY_ATTRIBUTES &sa)
  {
    if (!get_nt_native_path ())
      return NULL;
    InitializeObjectAttributes (&attr, &uni_path,
				objcaseinsensitive ()
				| (sa.bInheritHandle ? OBJ_INHERIT : 0),
				NULL, sa.lpSecurityDescriptor);
    return &attr;
  }
  inline POBJECT_ATTRIBUTES init_reopen_attr (OBJECT_ATTRIBUTES &attr, HANDLE h)
  {
    if (has_buggy_reopen ())
      InitializeObjectAttributes (&attr, get_nt_native_path (),
				  objcaseinsensitive (), NULL, NULL)
    else
      InitializeObjectAttributes (&attr, &ro_u_empty, objcaseinsensitive (),
				  h, NULL);
    return &attr;
  }
  inline size_t get_wide_win32_path_len ()
  {
    get_nt_native_path ();
    return uni_path.Length / sizeof (WCHAR);
  }

  PWCHAR get_wide_win32_path (PWCHAR wc);
  operator DWORD &() {return fileattr;}
  operator int () {return fileattr; }
# define cfree_and_null(x) \
  if (x) \
    { \
      cfree ((void *) (x)); \
      (x) = NULL; \
    }
  void free_strings ()
  {
    cfree_and_null (path);
    cfree_and_null (posix_path);
    cfree_and_null (wide_path);
  }
  path_conv& eq_worker (const path_conv& pc, const char *in_path,
			const char *in_posix_path)
  {
    free_strings ();
    memcpy (this, &pc, sizeof pc);
    path = cstrdup (in_path);
    conv_handle.dup (pc.conv_handle);
    posix_path = cstrdup(pc.posix_path);
    if (pc.wide_path)
      {
	wide_path = cwcsdup (uni_path.Buffer);
	if (!wide_path)
	  api_fatal ("cwcsdup would have returned NULL");
	uni_path.Buffer = wide_path;
      }
    return *this;
  }

  path_conv &operator << (const path_conv& pc)
  {
    const char *save_path;
    const char *save_posix_path;
    if (!path)
      save_path = pc.path;
    else
      {
	save_path = (char *) alloca (strlen (path) + 1);
	strcpy ((char *) save_path, path);
      }
    if (!posix_path)
      save_posix_path = pc.posix_path;
    else
      {
	save_posix_path = (char *) alloca (strlen (posix_path) + 1);
	strcpy ((char *) save_posix_path, path);
      }
    return eq_worker (pc, save_path, save_posix_path);
  }

  path_conv &operator =(const path_conv& pc)
  {
    return eq_worker (pc, pc.path, pc.posix_path);
  }
  dev_t get_device () {return dev.get_device ();}
  DWORD file_attributes () const {return fileattr;}
  void file_attributes (DWORD new_attr) {fileattr = new_attr;}
  DWORD fs_flags () const {return fs.flags ();}
  DWORD fs_name_len () const {return fs.name_len ();}
  bool fs_got_fs () const { return fs.got_fs (); }
  bool fs_is_fat () const {return fs.is_fat ();}
  bool fs_is_ntfs () const {return fs.is_ntfs ();}
  bool fs_is_refs () const {return fs.is_refs ();}
  bool fs_is_samba () const {return fs.is_samba ();}
  bool fs_is_nfs () const {return fs.is_nfs ();}
  bool fs_is_netapp () const {return fs.is_netapp ();}
  bool fs_is_cdrom () const {return fs.is_cdrom ();}
  bool fs_is_mvfs () const {return fs.is_mvfs ();}
  bool fs_is_cifs () const {return fs.is_cifs ();}
  bool fs_is_nwfs () const {return fs.is_nwfs ();}
  bool fs_is_ncfsd () const {return fs.is_ncfsd ();}
  bool fs_is_afs () const {return fs.is_afs ();}
  bool fs_is_prlfs () const {return fs.is_prlfs ();}
  fs_info_type fs_type () const {return fs.what_fs ();}
  ULONG fs_serial_number () const {return fs.serial_number ();}
  inline const char *set_path (const char *p)
  {
    if (path)
      cfree (modifiable_path ());
    char *new_path = (char *) cmalloc_abort (HEAP_STR, strlen (p) + 7);
    strcpy (new_path, p);
    return path = new_path;
  }
  bool is_binary ();

  HANDLE handle () const { return conv_handle.handle (); }
  PFILE_ALL_INFORMATION fai () { return conv_handle.fai (); }
  struct fattr3 *nfsattr () { return conv_handle.nfsattr (); }
  void reset_conv_handle () { conv_handle.set (NULL); }
  void close_conv_handle () { conv_handle.close (); }

  ino_t get_ino_by_handle (HANDLE h);
  inline const char *get_posix () const { return posix_path; }
  void __reg2 set_posix (const char *);
  DWORD get_symlink_length () { return symlink_length; };
 private:
  char *modifiable_path () {return (char *) path;}
};

/* Symlink marker */
#define SYMLINK_COOKIE "!<symlink>"

/* Socket marker */
#define SOCKET_COOKIE  "!<socket >"

/* Interix symlink marker */
#define INTERIX_SYMLINK_COOKIE  "IntxLNK\1"

enum fe_types
{
  FE_NADA = 0,		/* Nothing special */
  FE_NNF = 1,		/* Return NULL if not found */
  FE_CWD = 4,		/* Search CWD for program */
  FE_DLL = 8		/* Search for DLLs, not executables. */
};
const char *__reg3 find_exec (const char *name, path_conv& buf,
				 const char *search = "PATH",
				 unsigned opt = FE_NADA,
				 const char **known_suffix = NULL);

/* Common macros for checking for invalid path names */
#define isdrive(s) (isalpha (*(s)) && (s)[1] == ':')
#define iswdrive(s) (iswalpha (*(s)) && (s)[1] == L':')

static inline bool
has_exec_chars (const char *buf, int len)
{
  return len >= 2 &&
	 ((buf[0] == '#' && buf[1] == '!') ||
	  (buf[0] == ':' && buf[1] == '\n') ||
	  (buf[0] == 'M' && buf[1] == 'Z'));
}

int __reg3 pathmatch (const char *path1, const char *path2, bool caseinsensitive);
int __reg3 pathnmatch (const char *path1, const char *path2, int len, bool caseinsensitive);
bool __reg2 has_dot_last_component (const char *dir, bool test_dot_dot);

int __reg3 path_prefix_p (const char *path1, const char *path2, int len1,
		   bool caseinsensitive);

NTSTATUS file_get_fai (HANDLE, PFILE_ALL_INFORMATION);
int normalize_win32_path (const char *, char *, char *&);
int normalize_posix_path (const char *, char *, char *&);
PUNICODE_STRING __reg3 get_nt_native_path (const char *, UNICODE_STRING&, bool);

int __reg3 symlink_worker (const char *, const char *, bool);
