/* 
   Unix SMB/Netbios implementation.
   Version 1.9.
   Directory handling routines
   Copyright (C) Andrew Tridgell 1992-1998
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
   
   This program 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 General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "includes.h"

extern int DEBUGLEVEL;

/*
   This module implements directory related functions for Samba.
*/



static uint32 dircounter = 0;


#define NUMDIRPTRS 256


static struct dptr_struct {
	int pid;
	connection_struct *conn;
	uint32 lastused;
	void *ptr;
	BOOL valid;
	BOOL finished;
	BOOL expect_close;
	char *wcard; /* Field only used for trans2_ searches */
	uint16 attr; /* Field only used for trans2_ searches */
	char *path;
}
dirptrs[NUMDIRPTRS];


static int dptrs_open = 0;

/****************************************************************************
initialise the dir array
****************************************************************************/
void init_dptrs(void)
{
  static BOOL dptrs_init=False;
  int i;

  if (dptrs_init) return;
  for (i=0;i<NUMDIRPTRS;i++)    
    {
      dirptrs[i].valid = False;
      dirptrs[i].wcard = NULL;
      dirptrs[i].ptr = NULL;
      string_init(&dirptrs[i].path,"");
    }
  dptrs_init = True;
}

/****************************************************************************
idle a dptr - the directory is closed but the control info is kept
****************************************************************************/
static void dptr_idle(int key)
{
  if (dirptrs[key].valid && dirptrs[key].ptr) {
    DEBUG(4,("Idling dptr key %d\n",key));
    dptrs_open--;
    CloseDir(dirptrs[key].ptr);
    dirptrs[key].ptr = NULL;
  }    
}

/****************************************************************************
idle the oldest dptr
****************************************************************************/
static void dptr_idleoldest(void)
{
  int i;
  uint32 old=dircounter+1;
  int oldi= -1;
  for (i=0;i<NUMDIRPTRS;i++)
    if (dirptrs[i].valid && dirptrs[i].ptr && dirptrs[i].lastused < old) {
      old = dirptrs[i].lastused;
      oldi = i;
    }
  if (oldi != -1)
    dptr_idle(oldi);
  else
    DEBUG(0,("No dptrs available to idle??\n"));
}

/****************************************************************************
get the dir ptr for a dir index
****************************************************************************/
static void *dptr_get(int key,uint32 lastused)
{
	struct dptr_struct *dp = &dirptrs[key];

	if (dp->valid) {
		if (lastused) dp->lastused = lastused;
		if (!dp->ptr) {
			if (dptrs_open >= MAX_OPEN_DIRECTORIES)
				dptr_idleoldest();
			DEBUG(4,("Reopening dptr key %d\n",key));
			if ((dp->ptr = OpenDir(dp->conn, dp->path, True)))
				dptrs_open++;
		}
		return(dp->ptr);
	}
	return(NULL);
}

/****************************************************************************
get the dir path for a dir index
****************************************************************************/
char *dptr_path(int key)
{
  if (dirptrs[key].valid)
    return(dirptrs[key].path);
  return(NULL);
}

/****************************************************************************
get the dir wcard for a dir index (lanman2 specific)
****************************************************************************/
char *dptr_wcard(int key)
{
  if (dirptrs[key].valid)
    return(dirptrs[key].wcard);
  return(NULL);
}

/****************************************************************************
set the dir wcard for a dir index (lanman2 specific)
Returns 0 on ok, 1 on fail.
****************************************************************************/
BOOL dptr_set_wcard(int key, char *wcard)
{
  if (dirptrs[key].valid) {
    dirptrs[key].wcard = wcard;
    return True;
  }
  return False;
}

/****************************************************************************
set the dir attrib for a dir index (lanman2 specific)
Returns 0 on ok, 1 on fail.
****************************************************************************/
BOOL dptr_set_attr(int key, uint16 attr)
{
  if (dirptrs[key].valid) {
    dirptrs[key].attr = attr;
    return True;
  }
  return False;
}

/****************************************************************************
get the dir attrib for a dir index (lanman2 specific)
****************************************************************************/
uint16 dptr_attr(int key)
{
  if (dirptrs[key].valid)
    return(dirptrs[key].attr);
  return(0);
}

/****************************************************************************
close a dptr
****************************************************************************/
void dptr_close(int key)
{
  /* OS/2 seems to use -1 to indicate "close all directories" */
  if (key == -1) {
    int i;
    for (i=0;i<NUMDIRPTRS;i++) 
      dptr_close(i);
    return;
  }

  if (key < 0 || key >= NUMDIRPTRS) {
    DEBUG(3,("Invalid key %d given to dptr_close\n",key));
    return;
  }

  if (dirptrs[key].valid) {
    DEBUG(4,("closing dptr key %d\n",key));
    if (dirptrs[key].ptr) {
      CloseDir(dirptrs[key].ptr);
      dptrs_open--;
    }
    /* Lanman 2 specific code */
    if (dirptrs[key].wcard)
      free(dirptrs[key].wcard);
    dirptrs[key].valid = False;
    string_set(&dirptrs[key].path,"");
  }
}

/****************************************************************************
close all dptrs for a cnum
****************************************************************************/
void dptr_closecnum(connection_struct *conn)
{
  int i;
  for (i=0;i<NUMDIRPTRS;i++)
    if (dirptrs[i].valid && dirptrs[i].conn == conn)
      dptr_close(i);
}

/****************************************************************************
idle all dptrs for a cnum
****************************************************************************/
void dptr_idlecnum(connection_struct *conn)
{
  int i;
  for (i=0;i<NUMDIRPTRS;i++)
    if (dirptrs[i].valid && dirptrs[i].conn == conn && dirptrs[i].ptr)
      dptr_idle(i);
}

/****************************************************************************
close a dptr that matches a given path, only if it matches the pid also
****************************************************************************/
void dptr_closepath(char *path,int pid)
{
  int i;
  for (i=0;i<NUMDIRPTRS;i++)
    if (dirptrs[i].valid && pid == dirptrs[i].pid &&
	strequal(dirptrs[i].path,path))
      dptr_close(i);
}

/****************************************************************************
  start a directory listing
****************************************************************************/
static BOOL start_dir(connection_struct *conn,char *directory)
{
	DEBUG(5,("start_dir dir=%s\n",directory));

	if (!check_name(directory,conn))
		return(False);
  
	if (! *directory)
		directory = ".";

	conn->dirptr = OpenDir(conn, directory, True);
	if (conn->dirptr) {    
		dptrs_open++;
		string_set(&conn->dirpath,directory);
		return(True);
	}
  
	return(False);
}


/****************************************************************************
create a new dir ptr
****************************************************************************/
int dptr_create(connection_struct *conn,char *path, BOOL expect_close,int pid)
{
  int i;
  uint32 old;
  int oldi;

  if (!start_dir(conn,path))
    return(-2); /* Code to say use a unix error return code. */

  if (dptrs_open >= MAX_OPEN_DIRECTORIES)
    dptr_idleoldest();

  for (i=0;i<NUMDIRPTRS;i++)
    if (!dirptrs[i].valid)
      break;
  if (i == NUMDIRPTRS) i = -1;


  /* as a 2nd option, grab the oldest not marked for expect_close */
  if (i == -1) {
    old=dircounter+1;
    oldi= -1;
    for (i=0;i<NUMDIRPTRS;i++)
      if (!dirptrs[i].expect_close && dirptrs[i].lastused < old) {
	old = dirptrs[i].lastused;
	oldi = i;
      }
    i = oldi;
  }

  /* a 3rd option - grab the oldest one */
  if (i == -1) {
    old=dircounter+1;
    oldi= -1;
    for (i=0;i<NUMDIRPTRS;i++)
      if (dirptrs[i].lastused < old) {
	old = dirptrs[i].lastused;
	oldi = i;
      }
    i = oldi;
  }

  if (i == -1) {
    DEBUG(0,("Error - all dirptrs in use??\n"));
    return(-1);
  }

  if (dirptrs[i].valid)
    dptr_close(i);

  dirptrs[i].ptr = conn->dirptr;
  string_set(&dirptrs[i].path,path);
  dirptrs[i].lastused = dircounter++;
  dirptrs[i].finished = False;
  dirptrs[i].conn = conn;
  dirptrs[i].pid = pid;
  dirptrs[i].expect_close = expect_close;
  dirptrs[i].wcard = NULL; /* Only used in lanman2 searches */
  dirptrs[i].attr = 0; /* Only used in lanman2 searches */
  dirptrs[i].valid = True;

  DEBUG(3,("creating new dirptr %d for path %s, expect_close = %d\n",
	   i,path,expect_close));  

  return(i);
}

#define DPTR_MASK ((uint32)(((uint32)1)<<31))

/****************************************************************************
fill the 5 byte server reserved dptr field
****************************************************************************/
BOOL dptr_fill(char *buf1,unsigned int key)
{
  unsigned char *buf = (unsigned char *)buf1;
  void *p = dptr_get(key,0);
  uint32 offset;
  if (!p) {
    DEBUG(1,("filling null dirptr %d\n",key));
    return(False);
  }
  offset = TellDir(p);
  DEBUG(6,("fill on key %u dirptr 0x%lx now at %d\n",key,
	   (long)p,(int)offset));
  buf[0] = key;
  SIVAL(buf,1,offset | DPTR_MASK);
  return(True);
}


/****************************************************************************
return True is the offset is at zero
****************************************************************************/
BOOL dptr_zero(char *buf)
{
  return((IVAL(buf,1)&~DPTR_MASK) == 0);
}

/****************************************************************************
fetch the dir ptr and seek it given the 5 byte server field
****************************************************************************/
void *dptr_fetch(char *buf,int *num)
{
  unsigned int key = *(unsigned char *)buf;
  void *p = dptr_get(key,dircounter++);
  uint32 offset;
  if (!p) {
    DEBUG(3,("fetched null dirptr %d\n",key));
    return(NULL);
  }
  *num = key;
  offset = IVAL(buf,1)&~DPTR_MASK;
  SeekDir(p,offset);
  DEBUG(3,("fetching dirptr %d for path %s at offset %d\n",
	   key,dptr_path(key),offset));
  return(p);
}

/****************************************************************************
fetch the dir ptr.
****************************************************************************/
void *dptr_fetch_lanman2(int dptr_num)
{
  void *p = dptr_get(dptr_num,dircounter++);

  if (!p) {
    DEBUG(3,("fetched null dirptr %d\n",dptr_num));
    return(NULL);
  }
  DEBUG(3,("fetching dirptr %d for path %s\n",dptr_num,dptr_path(dptr_num)));
  return(p);
}

/****************************************************************************
check a filetype for being valid
****************************************************************************/
BOOL dir_check_ftype(connection_struct *conn,int mode,SMB_STRUCT_STAT *st,int dirtype)
{
  if (((mode & ~dirtype) & (aHIDDEN | aSYSTEM | aDIR)) != 0)
    return False;
  return True;
}

/****************************************************************************
  get a directory entry
****************************************************************************/
BOOL get_dir_entry(connection_struct *conn,char *mask,int dirtype,char *fname,
                   SMB_OFF_T *size,int *mode,time_t *date,BOOL check_descend)
{
  char *dname;
  BOOL found = False;
  SMB_STRUCT_STAT sbuf;
  pstring path;
  pstring pathreal;
  BOOL isrootdir;
  pstring filename;
  BOOL needslash;

  *path = *pathreal = *filename = 0;

  isrootdir = (strequal(conn->dirpath,"./") ||
	       strequal(conn->dirpath,".") ||
	       strequal(conn->dirpath,"/"));
  
  needslash = 
        ( conn->dirpath[strlen(conn->dirpath) -1] != '/');

  if (!conn->dirptr)
    return(False);
  
  while (!found)
    {
      dname = ReadDirName(conn->dirptr);

      DEBUG(6,("readdir on dirptr 0x%lx now at offset %d\n",
	       (long)conn->dirptr,TellDir(conn->dirptr)));
      
      if (dname == NULL) 
	return(False);
      
      pstrcpy(filename,dname);      

      if ((strcmp(filename,mask) == 0) ||
	  (name_map_mangle(filename,True,SNUM(conn)) &&
	   mask_match(filename,mask,False,False)))
	{
	  if (isrootdir && (strequal(filename,"..") || strequal(filename,".")))
	    continue;

	  pstrcpy(fname,filename);
	  *path = 0;
	  pstrcpy(path,conn->dirpath);
          if(needslash)
  	    pstrcat(path,"/");
	  pstrcpy(pathreal,path);
	  pstrcat(path,fname);
	  pstrcat(pathreal,dname);
	  if (dos_stat(pathreal,&sbuf) != 0) 
	    {
	      DEBUG(5,("Couldn't stat 1 [%s]\n",path));
	      continue;
	    }

	  if (check_descend &&
	      !strequal(fname,".") && !strequal(fname,".."))
	    continue;
	  
	  *mode = dos_mode(conn,pathreal,&sbuf);

	  if (!dir_check_ftype(conn,*mode,&sbuf,dirtype)) {
	    DEBUG(5,("[%s] attribs didn't match %x\n",filename,dirtype));
	    continue;
	  }

	  *size = sbuf.st_size;
	  *date = sbuf.st_mtime;

	  DEBUG(5,("get_dir_entry found %s fname=%s\n",pathreal,fname));
	  
	  found = True;
	}
    }

  return(found);
}



typedef struct
{
  int pos;
  int numentries;
  int mallocsize;
  char *data;
  char *current;
} Dir;


/*******************************************************************
open a directory
********************************************************************/
void *OpenDir(connection_struct *conn, char *name, BOOL use_veto)
{
  Dir *dirp;
  char *n;
  void *p = dos_opendir(name);
  int used=0;

  if (!p) return(NULL);
  dirp = (Dir *)malloc(sizeof(Dir));
  if (!dirp) {
    closedir(p);
    return(NULL);
  }
  dirp->pos = dirp->numentries = dirp->mallocsize = 0;
  dirp->data = dirp->current = NULL;

  while ((n = readdirname(p)))
  {
    int l = strlen(n)+1;

    /* If it's a vetoed file, pretend it doesn't even exist */
    if (use_veto && conn && IS_VETO_PATH(conn, n)) continue;

    if (used + l > dirp->mallocsize) {
      int s = MAX(used+l,used+2000);
      char *r;
      r = (char *)Realloc(dirp->data,s);
      if (!r) {
	DEBUG(0,("Out of memory in OpenDir\n"));
	break;
      }
      dirp->data = r;
      dirp->mallocsize = s;
      dirp->current = dirp->data;
    }
    pstrcpy(dirp->data+used,n);
    used += l;
    dirp->numentries++;
  }

  closedir(p);
  return((void *)dirp);
}


/*******************************************************************
close a directory
********************************************************************/
void CloseDir(void *p)
{
  Dir *dirp = (Dir *)p;
  if (!dirp) return;    
  if (dirp->data) free(dirp->data);
  free(dirp);
}

/*******************************************************************
read from a directory
********************************************************************/
char *ReadDirName(void *p)
{
  char *ret;
  Dir *dirp = (Dir *)p;

  if (!dirp || !dirp->current || dirp->pos >= dirp->numentries) return(NULL);

  ret = dirp->current;
  dirp->current = skip_string(dirp->current,1);
  dirp->pos++;

  return(ret);
}


/*******************************************************************
seek a dir
********************************************************************/
BOOL SeekDir(void *p,int pos)
{
  Dir *dirp = (Dir *)p;

  if (!dirp) return(False);

  if (pos < dirp->pos) {
    dirp->current = dirp->data;
    dirp->pos = 0;
  }

  while (dirp->pos < pos && ReadDirName(p)) ;

  return(dirp->pos == pos);
}

/*******************************************************************
tell a dir position
********************************************************************/
int TellDir(void *p)
{
  Dir *dirp = (Dir *)p;

  if (!dirp) return(-1);
  
  return(dirp->pos);
}


/* -------------------------------------------------------------------------- **
 * This section manages a global directory cache.
 * (It should probably be split into a separate module.  crh)
 * -------------------------------------------------------------------------- **
 */

typedef struct
  {
  ubi_dlNode  node;
  char       *path;
  char       *name;
  char       *dname;
  int         snum;
  } dir_cache_entry;

static ubi_dlNewList( dir_cache );

void DirCacheAdd( char *path, char *name, char *dname, int snum )
  /* ------------------------------------------------------------------------ **
   * Add an entry to the directory cache.
   *
   *  Input:  path  -
   *          name  -
   *          dname -
   *          snum  -
   *
   *  Output: None.
   *
   * ------------------------------------------------------------------------ **
   */
  {
  int               pathlen;
  int               namelen;
  dir_cache_entry  *entry;

  /* Allocate the structure & string space in one go so that it can be freed
   * in one call to free().
   */
  pathlen = strlen( path ) +1;  /* Bytes required to store path (with nul). */
  namelen = strlen( name ) +1;  /* Bytes required to store name (with nul). */
  entry = (dir_cache_entry *)malloc( sizeof( dir_cache_entry )
                                   + pathlen
                                   + namelen
                                   + strlen( dname ) +1 );
  if( NULL == entry )   /* Not adding to the cache is not fatal,  */
    return;             /* so just return as if nothing happened. */

  /* Set pointers correctly and load values. */
  entry->path  = pstrcpy( (char *)&entry[1],       path);
  entry->name  = pstrcpy( &(entry->path[pathlen]), name);
  entry->dname = pstrcpy( &(entry->name[namelen]), dname);
  entry->snum  = snum;

  /* Add the new entry to the linked list. */
  (void)ubi_dlAddHead( dir_cache, entry );
  DEBUG( 4, ("Added dir cache entry %s %s -> %s\n", path, name, dname ) );

  /* Free excess cache entries. */
  while( DIRCACHESIZE < dir_cache->count )
    free( ubi_dlRemTail( dir_cache ) );

  } /* DirCacheAdd */


char *DirCacheCheck( char *path, char *name, int snum )
  /* ------------------------------------------------------------------------ **
   * Search for an entry to the directory cache.
   *
   *  Input:  path  -
   *          name  -
   *          snum  -
   *
   *  Output: The dname string of the located entry, or NULL if the entry was
   *          not found.
   *
   *  Notes:  This uses a linear search, which is is okay because of
   *          the small size of the cache.  Use a splay tree or hash
   *          for large caches.
   *
   * ------------------------------------------------------------------------ **
   */
  {
  dir_cache_entry *entry;

  for( entry = (dir_cache_entry *)ubi_dlFirst( dir_cache );
       NULL != entry;
       entry = (dir_cache_entry *)ubi_dlNext( entry ) )
    {
    if( entry->snum == snum
        && 0 == strcmp( name, entry->name )
        && 0 == strcmp( path, entry->path ) )
      {
      DEBUG(4, ("Got dir cache hit on %s %s -> %s\n",path,name,entry->dname));
      return( entry->dname );
      }
    }

  return(NULL);
  } /* DirCacheCheck */

void DirCacheFlush(int snum)
  /* ------------------------------------------------------------------------ **
   * Remove all cache entries which have an snum that matches the input.
   *
   *  Input:  snum  -
   *
   *  Output: None.
   *
   * ------------------------------------------------------------------------ **
   */
{
	dir_cache_entry *entry;
	ubi_dlNodePtr    next;

	for(entry = (dir_cache_entry *)ubi_dlFirst( dir_cache ); 
	    NULL != entry; )  {
		next = ubi_dlNext( entry );
		if( entry->snum == snum )
			free( ubi_dlRemThis( dir_cache, entry ) );
		entry = (dir_cache_entry *)next;
	}
} /* DirCacheFlush */

/* -------------------------------------------------------------------------- **
 * End of the section that manages the global directory cache.
 * -------------------------------------------------------------------------- **
 */