path: root/winsup/cygwin/cygheap.h

/* cygheap.h: Cygwin heap manager.

   Copyright 2000, 2001 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. */

#undef cfree

enum cygheap_types
{
  HEAP_FHANDLER,
  HEAP_STR,
  HEAP_ARGV,
  HEAP_BUF,
  HEAP_MOUNT,
  HEAP_1_START,
  HEAP_1_STR,
  HEAP_1_ARGV,
  HEAP_1_BUF,
  HEAP_1_EXEC,
  HEAP_1_MAX = 100
};

#define incygheap(s) (cygheap && ((char *) (s) >= (char *) cygheap) && ((char *) (s) <= ((char *) cygheap_max)))

struct _cmalloc_entry
{
  union
  {
    DWORD b;
    char *ptr;
  };
  struct _cmalloc_entry *prev;
  char data[0];
};

struct cygheap_root_mount_info
{
  char posix_path[MAX_PATH];
  unsigned posix_pathlen;
  char native_path[MAX_PATH];
  unsigned native_pathlen;
};

/* CGF: FIXME This doesn't belong here */

int path_prefix_p (const char *path1, const char *path2, int len1) __attribute__ ((regparm (3)));
class cygheap_root
{
  /* Root directory information.
     This is used after a chroot is called. */
  struct cygheap_root_mount_info *m;

public:
  bool posix_ok (const char *path)
  {
    if (!m)
      return 1;
    return path_prefix_p (m->posix_path, path, m->posix_pathlen);
  }
  bool ischroot_native (const char *path)
  {
    if (!m)
      return 1;
    return strncasematch (m->native_path, path, m->native_pathlen)
	    && (path[m->native_pathlen] == '\\' || !path[m->native_pathlen]);
  }
  const char *unchroot (const char *path)
  {
    if (!m)
      return path;
    const char *p = path + m->posix_pathlen;
    if (!*p)
      p = "/";
    return p;
  }
  bool exists () {return !!m;}
  void set (const char *posix, const char *native);
  size_t posix_length () const { return m->posix_pathlen; }
  const char *posix_path () const { return m->posix_path; }
  size_t native_length () const { return m->native_pathlen; }
  const char *native_path () const { return m->native_path; }
};

class cygheap_user
{
  /* Extendend user information.
     The information is derived from the internal_getlogin call
     when on a NT system. */
  char  *pname;         /* user's name */
  char  *plogsrv;       /* Logon server, may be FQDN */
  char  *pdomain;       /* Logon domain of the user */
  PSID   psid;          /* buffer for user's SID */
public:
  uid_t orig_uid;      /* Remains intact even after impersonation */
  uid_t orig_gid;      /* Ditto */
  uid_t real_uid;      /* Remains intact on seteuid, replaced by setuid */
  gid_t real_gid;      /* Ditto */

  /* token is needed if set(e)uid should be called. It can be set by a call
     to `set_impersonation_token()'. */
  HANDLE token;
  BOOL   impersonated;

  cygheap_user () : pname (NULL), plogsrv (NULL), pdomain (NULL),
		    psid (NULL), token (INVALID_HANDLE_VALUE) {}
  ~cygheap_user ();

  void set_name (const char *new_name);
  const char *name () const { return pname; }

  void set_logsrv (const char *new_logsrv);
  const char *logsrv () const { return plogsrv; }

  void set_domain (const char *new_domain);
  const char *domain () const { return pdomain; }

  BOOL set_sid (PSID new_sid);
  PSID sid () const { return psid; }

  void operator =(cygheap_user &user)
  {
    set_name (user.name ());
    set_logsrv (user.logsrv ());
    set_domain (user.domain ());
    set_sid (user.sid ());
  }
};

/* cwd cache stuff.  */

class muto;

struct cwdstuff
{
  char *posix;
  char *win32;
  DWORD hash;
  muto *lock;
  char *get (char *buf, int need_posix = 1, int with_chroot = 0, unsigned ulen = MAX_PATH);
  DWORD get_hash ();
  void init ();
  void fixup_after_exec (char *win32, char *posix, DWORD hash);
  bool get_initial ();
  void set (const char *win32_cwd, const char *posix_cwd = NULL);
};

struct init_cygheap
{
  _cmalloc_entry *chain;
  char *buckets[32];
  struct /* User heap stuff. */
    {
      void *heapbase;
      void *heapptr;
      void *heaptop;
    };
  cygheap_root root;
  cygheap_user user;
  mode_t umask;
  HANDLE shared_h;
  HANDLE console_h;
  HANDLE etc_changed_h;
  cwdstuff cwd;
  dtable fdtab;

  bool etc_changed ();
};

#define CYGHEAPSIZE (sizeof (init_cygheap) + (4000 * sizeof (fhandler_union)) + (2 * 65536))

extern init_cygheap *cygheap;
extern void *cygheap_max;

class cygheap_fdmanip
{
 protected:
  int fd;
  fhandler_base **fh;
  bool locked;
 public:
  cygheap_fdmanip () {}
  virtual ~cygheap_fdmanip ()
  {
    if (locked)
      ReleaseResourceLock (LOCK_FD_LIST, WRITE_LOCK | READ_LOCK, "cygheap_fdmanip");
  }
  void release ()
  {
    cygheap->fdtab.release (fd);
  }
  operator int &() {return fd;}
  operator fhandler_base* &() {return *fh;}
  void operator = (fhandler_base *fh) {*this->fh = fh;}
  fhandler_base *operator -> () const {return *fh;}
};

class cygheap_fdnew : public cygheap_fdmanip
{
 public:
  cygheap_fdnew (int seed_fd = -1, bool lockit = true)
  {
    if (lockit)
      SetResourceLock (LOCK_FD_LIST, WRITE_LOCK | READ_LOCK, "cygheap_fdnew");
    if (seed_fd < 0)
      fd = cygheap->fdtab.find_unused_handle ();
    else
      fd = cygheap->fdtab.find_unused_handle (seed_fd + 1);
    if (fd >= 0)
      {
	locked = lockit;
	fh = cygheap->fdtab + fd;
      }
    else
      {
	set_errno (EMFILE);
	if (lockit)
	  ReleaseResourceLock (LOCK_FD_LIST, WRITE_LOCK | READ_LOCK, "cygheap_fdnew");
	locked = false;
      }
  }
};

class cygheap_fdget : public cygheap_fdmanip
{
 public:
  cygheap_fdget (int fd, bool lockit = false)
  {
    if (lockit)
      SetResourceLock (LOCK_FD_LIST, READ_LOCK, "cygheap_fdget");
    if (fd >= 0 && fd < (int) cygheap->fdtab.size
	&& *(fh = cygheap->fdtab + fd) != NULL)
      {
	this->fd = fd;
	locked = lockit;
      }
    else
      {
	this->fd = -1;
	set_errno (EBADF);
	if (lockit)
	  ReleaseResourceLock (LOCK_FD_LIST, READ_LOCK, "cygheap_fdget");
	locked = false;
      }
  }
};

class child_info;
void *__stdcall cygheap_setup_for_child (child_info *ci, bool dup_later) __attribute__ ((regparm(2)));
void __stdcall cygheap_setup_for_child_cleanup (void *, child_info *, bool) __attribute__ ((regparm(3)));
void __stdcall cygheap_fixup_in_child (child_info *, bool);
extern "C" {
void __stdcall cfree (void *) __attribute__ ((regparm(1)));
void *__stdcall cmalloc (cygheap_types, DWORD) __attribute__ ((regparm(2)));
void *__stdcall crealloc (void *, DWORD) __attribute__ ((regparm(2)));
void *__stdcall ccalloc (cygheap_types, DWORD, DWORD) __attribute__ ((regparm(3)));
char *__stdcall cstrdup (const char *) __attribute__ ((regparm(1)));
char *__stdcall cstrdup1 (const char *) __attribute__ ((regparm(1)));
void __stdcall cygheap_init ();
}