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open.c

/* 
   Unix SMB/Netbios implementation.
   Version 1.9.
   file opening and share modes
   Copyright (C) Andrew Tridgell 1992-1998
   Copyright (C) Jeremy Allison 2001
   
   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"

#ifndef ENOSYS
#define ENOSYS    (-1)
#endif

extern userdom_struct current_user_info;
extern uint16 global_oplock_port;
extern BOOL global_client_failed_oplock_break;

/****************************************************************************
 fd support routines - attempt to do a dos_open.
****************************************************************************/

static int fd_open(struct connection_struct *conn, char *fname, 
               int flags, mode_t mode)
{
      int fd;
      pstring cvt_buf;

#ifdef O_NOFOLLOW
      if (!lp_symlinks(SNUM(conn)))
            flags |= O_NOFOLLOW;
#endif

      fd = conn->vfs_ops.open(conn,dos_to_unix(cvt_buf, fname),flags,mode);

      /* Fix for files ending in '.' */
      if((fd == -1) && (errno == ENOENT) &&
         (strchr(fname,'.')==NULL)) {
            pstrcat(fname,".");
            fd = conn->vfs_ops.open(conn,dos_to_unix(cvt_buf, fname),flags,mode);
      }

      DEBUG(10,("fd_open: name %s, flags = 0%o mode = 0%o, fd = %d. %s\n", fname,
            flags, (int)mode, fd, (fd == -1) ? strerror(errno) : "" ));

      return fd;
}

/****************************************************************************
 Close the file associated with a fsp.
****************************************************************************/

int fd_close(struct connection_struct *conn, files_struct *fsp)
{
      if (fsp->fd == -1)
            return 0; /* what we used to call a stat open. */
      return fd_close_posix(conn, fsp);
}


/****************************************************************************
 Check a filename for the pipe string.
****************************************************************************/

static void check_for_pipe(char *fname)
{
      /* special case of pipe opens */
      char s[10];
      StrnCpy(s,fname,sizeof(s)-1);
      strlower(s);
      if (strstr(s,"pipe/")) {
            DEBUG(3,("Rejecting named pipe open for %s\n",fname));
            unix_ERR_class = ERRSRV;
            unix_ERR_code = ERRaccess;
            unix_ERR_ntstatus = NT_STATUS_ACCESS_DENIED;
      }
}

/****************************************************************************
 Open a file.
****************************************************************************/

static BOOL open_file(files_struct *fsp,connection_struct *conn,
                  const char *fname1,SMB_STRUCT_STAT *psbuf,int flags,mode_t mode, uint32 desired_access)
{
      extern struct current_user current_user;
      pstring fname;
      int accmode = (flags & O_ACCMODE);
      int local_flags = flags;
      pstring cvt_buf;

      fsp->fd = -1;
      fsp->oplock_type = NO_OPLOCK;
      errno = EPERM;

      pstrcpy(fname,fname1);

      /* Check permissions */

      /*
       * This code was changed after seeing a client open request 
       * containing the open mode of (DENY_WRITE/read-only) with
       * the 'create if not exist' bit set. The previous code
       * would fail to open the file read only on a read-only share
       * as it was checking the flags parameter  directly against O_RDONLY,
       * this was failing as the flags parameter was set to O_RDONLY|O_CREAT.
       * JRA.
       */

      if (!CAN_WRITE(conn)) {
            /* It's a read-only share - fail if we wanted to write. */
            if(accmode != O_RDONLY) {
                  DEBUG(3,("Permission denied opening %s\n",fname));
                  check_for_pipe(fname);
                  return False;
            } else if(flags & O_CREAT) {
                  /* We don't want to write - but we must make sure that O_CREAT
                     doesn't create the file if we have write access into the
                     directory.
                  */
                  flags &= ~O_CREAT;
            }
      }

      /*
       * This little piece of insanity is inspired by the
       * fact that an NT client can open a file for O_RDONLY,
       * but set the create disposition to FILE_EXISTS_TRUNCATE.
       * If the client *can* write to the file, then it expects to
       * truncate the file, even though it is opening for readonly.
       * Quicken uses this stupid trick in backup file creation...
       * Thanks *greatly* to "David W. Chapman Jr." <dwcjr@inethouston.net>
       * for helping track this one down. It didn't bite us in 2.0.x
       * as we always opened files read-write in that release. JRA.
       */

      if ((accmode == O_RDONLY) && ((flags & O_TRUNC) == O_TRUNC)) {
            DEBUG(10,("open_file: truncate requested on read-only open for file %s\n",fname ));
            local_flags = (flags & ~O_ACCMODE)|O_RDWR;
      }

      /* actually do the open */

      if ((desired_access & (FILE_READ_DATA|FILE_WRITE_DATA|FILE_APPEND_DATA|FILE_EXECUTE)) ||
                  (local_flags & O_CREAT) || ((local_flags & O_TRUNC) == O_TRUNC) ) {

            /*
             * We can't actually truncate here as the file may be locked.
             * open_file_shared will take care of the truncate later. JRA.
             */

            local_flags &= ~O_TRUNC;

#if defined(O_NONBLOCK) && defined(S_ISFIFO)
            /*
             * We would block on opening a FIFO with no one else on the
             * other end. Do what we used to do and add O_NONBLOCK to the
             * open flags. JRA.
             */

            if (VALID_STAT(*psbuf) && S_ISFIFO(psbuf->st_mode))
                  local_flags |= O_NONBLOCK;
#endif
            fsp->fd = fd_open(conn, fname, local_flags, mode);

            if (fsp->fd == -1)  {
                  DEBUG(3,("Error opening file %s (%s) (local_flags=%d) (flags=%d)\n",
                         fname,strerror(errno),local_flags,flags));
                  check_for_pipe(fname);
                  return False;
            }
      } else
            fsp->fd = -1; /* What we used to call a stat open. */

      if (!VALID_STAT(*psbuf)) {
            int ret;

            if (fsp->fd == -1)
                  ret = vfs_stat(conn, fname, psbuf, cvt_buf);
            else {
                  ret = vfs_fstat(fsp,fsp->fd,psbuf);
                  /* If we have an fd, this stat should succeed. */
                  if (ret == -1)
                        DEBUG(0,("Error doing fstat on open file %s (%s)\n", fname,strerror(errno) ));
            }

            /* For a non-io open, this stat failing means file not found. JRA */
            if (ret == -1) {
                  fd_close(conn, fsp);
                  return False;
            }
      }

      /*
       * POSIX allows read-only opens of directories. We don't
       * want to do this (we use a different code path for this)
       * so catch a directory open and return an EISDIR. JRA.
       */

      if(S_ISDIR(psbuf->st_mode)) {
            fd_close(conn, fsp);
            errno = EISDIR;
            return False;
      }

      fsp->mode = psbuf->st_mode;
      fsp->inode = psbuf->st_ino;
      fsp->dev = psbuf->st_dev;
      fsp->vuid = current_user.vuid;
      fsp->size = psbuf->st_size;
      fsp->pos = -1;
      fsp->can_lock = True;
      fsp->can_read = ((flags & O_WRONLY)==0);
      fsp->can_write = ((flags & (O_WRONLY|O_RDWR))!=0);
      fsp->share_mode = 0;
      fsp->desired_access = desired_access;
      fsp->print_file = False;
      fsp->modified = False;
      fsp->oplock_type = NO_OPLOCK;
      fsp->sent_oplock_break = NO_BREAK_SENT;
      fsp->is_directory = False;
      fsp->directory_delete_on_close = False;
      fsp->conn = conn;
      /*
       * Note that the file name here is the *untranslated* name
       * ie. it is still in the DOS codepage sent from the client.
       * All use of this filename will pass though the sys_xxxx
       * functions which will do the dos_to_unix translation before
       * mapping into a UNIX filename. JRA.
       */
      string_set(&fsp->fsp_name,fname);
      fsp->wbmpx_ptr = NULL;      
      fsp->wcp = NULL; /* Write cache pointer. */

      DEBUG(2,("%s opened file %s read=%s write=%s (numopen=%d)\n",
             *current_user_info.smb_name ? current_user_info.smb_name : conn->user,fsp->fsp_name,
             BOOLSTR(fsp->can_read), BOOLSTR(fsp->can_write),
             conn->num_files_open + 1));

      return True;
}

/****************************************************************************
  C. Hoch 11/22/95
  Helper for open_file_shared. 
  Truncate a file after checking locking; close file if locked.
  **************************************************************************/

static int truncate_unless_locked(struct connection_struct *conn, files_struct *fsp)
{
      SMB_BIG_UINT mask = (SMB_BIG_UINT)-1;

      if (is_locked(fsp,fsp->conn,mask,0,WRITE_LOCK,True)){
            errno = EACCES;
            unix_ERR_class = ERRDOS;
            unix_ERR_code = ERRlock;
            unix_ERR_ntstatus = dos_to_ntstatus(ERRDOS, ERRlock);
            return -1;
      } else {
            return conn->vfs_ops.ftruncate(fsp,fsp->fd,0); 
      }
}

/*******************************************************************
return True if the filename is one of the special executable types
********************************************************************/
static BOOL is_executable(const char *fname)
{
      if ((fname = strrchr(fname,'.'))) {
            if (strequal(fname,".com") ||
                strequal(fname,".dll") ||
                strequal(fname,".exe") ||
                strequal(fname,".sym")) {
                  return True;
            }
      }
      return False;
}

enum {AFAIL,AREAD,AWRITE,AALL};

/*******************************************************************
reproduce the share mode access table
this is horrendoously complex, and really can't be justified on any
rational grounds except that this is _exactly_ what NT does. See
the DENY1 and DENY2 tests in smbtorture for a comprehensive set of
test routines.
********************************************************************/
static int access_table(int new_deny,int old_deny,int old_mode,
                  BOOL same_pid, BOOL isexe)
{
        if (new_deny == DENY_ALL || old_deny == DENY_ALL) return(AFAIL);

        if (same_pid) {
              if (isexe && old_mode == DOS_OPEN_RDONLY && 
                  old_deny == DENY_DOS && new_deny == DENY_READ) {
                    return AFAIL;
              }
              if (!isexe && old_mode == DOS_OPEN_RDONLY && 
                  old_deny == DENY_DOS && new_deny == DENY_DOS) {
                    return AREAD;
              }
              if (new_deny == DENY_FCB && old_deny == DENY_DOS) {
                    if (isexe) return AFAIL;
                    if (old_mode == DOS_OPEN_RDONLY) return AFAIL;
                    return AALL;
              }
              if (old_mode == DOS_OPEN_RDONLY && old_deny == DENY_DOS) {
                    if (new_deny == DENY_FCB || new_deny == DENY_READ) {
                          if (isexe) return AREAD;
                          return AFAIL;
                    }
              }
              if (old_deny == DENY_FCB) {
                    if (new_deny == DENY_DOS || new_deny == DENY_FCB) return AALL;
                    return AFAIL;
              }
        }

        if (old_deny == DENY_DOS || new_deny == DENY_DOS || 
            old_deny == DENY_FCB || new_deny == DENY_FCB) {
              if (isexe) {
                    if (old_deny == DENY_FCB || new_deny == DENY_FCB) {
                          return AFAIL;
                    }
                    if (old_deny == DENY_DOS) {
                          if (new_deny == DENY_READ && 
                              (old_mode == DOS_OPEN_RDONLY || 
                               old_mode == DOS_OPEN_RDWR)) {
                                return AFAIL;
                          }
                          if (new_deny == DENY_WRITE && 
                              (old_mode == DOS_OPEN_WRONLY || 
                               old_mode == DOS_OPEN_RDWR)) {
                                return AFAIL;
                          }
                          return AALL;
                    }
                    if (old_deny == DENY_NONE) return AALL;
                    if (old_deny == DENY_READ) return AWRITE;
                    if (old_deny == DENY_WRITE) return AREAD;
              }
              /* it isn't a exe, dll, sym or com file */
              if (old_deny == new_deny && same_pid)
                    return(AALL);    

              if (old_deny == DENY_READ || new_deny == DENY_READ) return AFAIL;
              if (old_mode == DOS_OPEN_RDONLY) return(AREAD);
              
              return(AFAIL);
        }
        
        switch (new_deny) 
              {
              case DENY_WRITE:
                    if (old_deny==DENY_WRITE && old_mode==DOS_OPEN_RDONLY) return(AREAD);
                    if (old_deny==DENY_READ && old_mode==DOS_OPEN_RDONLY) return(AWRITE);
                    if (old_deny==DENY_NONE && old_mode==DOS_OPEN_RDONLY) return(AALL);
                    return(AFAIL);
              case DENY_READ:
                    if (old_deny==DENY_WRITE && old_mode==DOS_OPEN_WRONLY) return(AREAD);
                    if (old_deny==DENY_READ && old_mode==DOS_OPEN_WRONLY) return(AWRITE);
                    if (old_deny==DENY_NONE && old_mode==DOS_OPEN_WRONLY) return(AALL);
                    return(AFAIL);
              case DENY_NONE:
                    if (old_deny==DENY_WRITE) return(AREAD);
                    if (old_deny==DENY_READ) return(AWRITE);
                    if (old_deny==DENY_NONE) return(AALL);
                    return(AFAIL);      
              }
        return(AFAIL);      
}


/****************************************************************************
check if we can open a file with a share mode
****************************************************************************/

static BOOL check_share_mode(connection_struct *conn, share_mode_entry *share, int share_mode, uint32 desired_access,
                       const char *fname, BOOL fcbopen, int *flags)
{
      int deny_mode = GET_DENY_MODE(share_mode);
      int old_open_mode = GET_OPEN_MODE(share->share_mode);
      int old_deny_mode = GET_DENY_MODE(share->share_mode);

      /*
       * share modes = false means don't bother to check for
       * DENY mode conflict. This is a *really* bad idea :-). JRA.
       */

      if(!lp_share_modes(SNUM(conn)))
            return True;

      /*
       * Don't allow any opens once the delete on close flag has been
       * set.
       */

      if (GET_DELETE_ON_CLOSE_FLAG(share->share_mode)) {
            DEBUG(5,("check_share_mode: Failing open on file %s as delete on close flag is set.\n",
                  fname ));
            /* Use errno to map to correct error. */
            unix_ERR_class = SMB_SUCCESS;
            unix_ERR_code = 0;
            unix_ERR_ntstatus = NT_STATUS_OK;
            return False;
      }

      /* this is a nasty hack, but necessary until we rewrite our open
         handling to use a NTCreateX call as the basic call.
         NT may open a file with neither read nor write access, and in
               this case it expects the open not to conflict with any
               existing deny modes. This happens (for example) during a
               "xcopy /o" where the second file descriptor is used for
               ACL sets
               (tridge)
      */

      /*
       * This is a bit wierd - the test for desired access not having the
       * critical bits seems seems odd. Firstly, if both opens have no
       * critical bits then always ignore. Then check the "allow delete"
       * then check for either. This probably isn't quite right yet but
       * gets us much closer. JRA.
       */

      /*
       * If desired_access doesn't contain READ_DATA,WRITE_DATA,APPEND_DATA or EXECUTE
       * and the existing desired_acces then share modes don't conflict.
       */

      if ( !(desired_access & (FILE_READ_DATA|FILE_WRITE_DATA|FILE_APPEND_DATA|FILE_EXECUTE)) &&
            !(share->desired_access & (FILE_READ_DATA|FILE_WRITE_DATA|FILE_APPEND_DATA|FILE_EXECUTE)) ) {

            /*
             * Wrinkle discovered by smbtorture....
             * If both are non-io open and requester is asking for delete and current open has delete access
             * but neither open has allowed file share delete then deny.... this is very strange and
             * seems to be the only case in which non-io opens conflict. JRA.
             */

            if ((desired_access & DELETE_ACCESS) && (share->desired_access & DELETE_ACCESS) && 
                        (!GET_ALLOW_SHARE_DELETE(share->share_mode) || !GET_ALLOW_SHARE_DELETE(share_mode))) {
                  DEBUG(5,("check_share_mode: Failing open on file %s as delete access requests conflict.\n",
                        fname ));
                  unix_ERR_class = ERRDOS;
                  unix_ERR_code = ERRbadshare;
                  unix_ERR_ntstatus = NT_STATUS_SHARING_VIOLATION;

                  return False;
            }

            DEBUG(5,("check_share_mode: Allowing open on file %s as both desired access (0x%x) \
and existing desired access (0x%x) are non-data opens\n", 
                  fname, (unsigned int)desired_access, (unsigned int)share->desired_access ));
            return True;
      }

      /*
       * If delete access was requested and the existing share mode doesn't have
       * ALLOW_SHARE_DELETE then deny.
       */

      if ((desired_access & DELETE_ACCESS) && !GET_ALLOW_SHARE_DELETE(share->share_mode)) {
            DEBUG(5,("check_share_mode: Failing open on file %s as delete access requested and allow share delete not set.\n",
                  fname ));
            unix_ERR_class = ERRDOS;
            unix_ERR_code = ERRbadshare;
            unix_ERR_ntstatus = NT_STATUS_SHARING_VIOLATION;

            return False;
      }

      /*
       * The inverse of the above.
       * If delete access was granted and the new share mode doesn't have
       * ALLOW_SHARE_DELETE then deny.
       */

      if ((share->desired_access & DELETE_ACCESS) && !GET_ALLOW_SHARE_DELETE(share_mode)) {
            DEBUG(5,("check_share_mode: Failing open on file %s as delete access granted and allow share delete not requested.\n",
                  fname ));
            unix_ERR_class = ERRDOS;
            unix_ERR_code = ERRbadshare;
            unix_ERR_ntstatus = NT_STATUS_SHARING_VIOLATION;

            return False;
      }

      /*
       * If desired_access doesn't contain READ_DATA,WRITE_DATA,APPEND_DATA or EXECUTE
       * then share modes don't conflict. Likewise with existing desired access.
       */

      if ( !(desired_access & (FILE_READ_DATA|FILE_WRITE_DATA|FILE_APPEND_DATA|FILE_EXECUTE)) ||
            !(share->desired_access & (FILE_READ_DATA|FILE_WRITE_DATA|FILE_APPEND_DATA|FILE_EXECUTE)) ) {
            DEBUG(5,("check_share_mode: Allowing open on file %s as desired access (0x%x) doesn't conflict with\
existing desired access (0x%x).\n", fname, (unsigned int)desired_access, (unsigned int)share->desired_access ));
            return True;
      }

      {
            int access_allowed = access_table(deny_mode,old_deny_mode,old_open_mode,
                                    (share->pid == sys_getpid()),is_executable(fname));

            if ((access_allowed == AFAIL) ||
                  (!fcbopen && (access_allowed == AREAD && *flags == O_RDWR)) ||
                  (access_allowed == AREAD && *flags != O_RDONLY) ||
                  (access_allowed == AWRITE && *flags != O_WRONLY)) {

                  DEBUG(2,("Share violation on file (%d,%d,%d,%d,%s,fcbopen = %d, flags = %d) = %d\n",
                        deny_mode,old_deny_mode,old_open_mode,
                        (int)share->pid,fname, fcbopen, *flags, access_allowed));

                  unix_ERR_class = ERRDOS;
                  unix_ERR_code = ERRbadshare;
                  unix_ERR_ntstatus = NT_STATUS_SHARING_VIOLATION;

                  return False;
            }

            if (access_allowed == AREAD)
                  *flags = O_RDONLY;

            if (access_allowed == AWRITE)
                  *flags = O_WRONLY;

      }

      return True;
}

/****************************************************************************
 Deal with open deny mode and oplock break processing.
 Invarient: Share mode must be locked on entry and exit.
 Returns -1 on error, or number of share modes on success (may be zero).
****************************************************************************/

static int open_mode_check(connection_struct *conn, const char *fname, SMB_DEV_T dev,
                  SMB_INO_T inode,
                  uint32 desired_access,
                  int share_mode, int *p_flags, int *p_oplock_request,
                  BOOL *p_all_current_opens_are_level_II)
{
      int i;
      int num_share_modes;
      int oplock_contention_count = 0;
      share_mode_entry *old_shares = 0;
      BOOL fcbopen = False;
      BOOL broke_oplock;      

      if(GET_OPEN_MODE(share_mode) == DOS_OPEN_FCB)
            fcbopen = True;

      num_share_modes = get_share_modes(conn, dev, inode, &old_shares);

      if(num_share_modes == 0)
            return 0;

      /*
       * Check if the share modes will give us access.
       */

      do {
            share_mode_entry broken_entry;

            broke_oplock = False;
            *p_all_current_opens_are_level_II = True;

            for(i = 0; i < num_share_modes; i++) {
                  share_mode_entry *share_entry = &old_shares[i];

                  /* 
                   * By observation of NetBench, oplocks are broken *before* share
                   * modes are checked. This allows a file to be closed by the client
                   * if the share mode would deny access and the client has an oplock. 
                   * Check if someone has an oplock on this file. If so we must break 
                   * it before continuing. 
                   */

                  if((*p_oplock_request && EXCLUSIVE_OPLOCK_TYPE(share_entry->op_type)) ||
                                    (!*p_oplock_request && (share_entry->op_type != NO_OPLOCK))) {

                        BOOL opb_ret;

                        DEBUG(5,("open_mode_check: oplock_request = %d, breaking oplock (%x) on file %s, \
dev = %x, inode = %.0f\n", *p_oplock_request, share_entry->op_type, fname, (unsigned int)dev, (double)inode));

                        /* Oplock break - unlock to request it. */
                        unlock_share_entry(conn, dev, inode);

                        opb_ret = request_oplock_break(share_entry, False);

                        /* Now relock. */
                        lock_share_entry(conn, dev, inode);

                        if(opb_ret == False) {
                              DEBUG(0,("open_mode_check: FAILED when breaking oplock (%x) on file %s, \
dev = %x, inode = %.0f\n", old_shares[i].op_type, fname, (unsigned int)dev, (double)inode));
                              SAFE_FREE(old_shares);
                              errno = EACCES;
                              unix_ERR_class = ERRDOS;
                              unix_ERR_code = ERRbadshare;
                              unix_ERR_ntstatus = NT_STATUS_SHARING_VIOLATION;
                              return -1;
                        }

                        broke_oplock = True;
                        broken_entry = *share_entry;
                        break;

                  } else if (!LEVEL_II_OPLOCK_TYPE(share_entry->op_type)) {
                        *p_all_current_opens_are_level_II = False;
                  }

                  /* someone else has a share lock on it, check to see if we can too */
                  if (!check_share_mode(conn, share_entry, share_mode, desired_access, 
                                    fname, fcbopen, p_flags)) {
                        SAFE_FREE(old_shares);
                        errno = EACCES;
                        return -1;
                  }

            } /* end for */

            if(broke_oplock) {
                  SAFE_FREE(old_shares);
                  num_share_modes = get_share_modes(conn, dev, inode, &old_shares);
                  oplock_contention_count++;

                  /* Paranoia check that this is no longer an exlusive entry. */
                  for(i = 0; i < num_share_modes; i++) {
                        share_mode_entry *share_entry = &old_shares[i];

                        if (share_modes_identical(&broken_entry, share_entry) && 
                                                EXCLUSIVE_OPLOCK_TYPE(share_entry->op_type) ) {

                              /*
                               * This should not happen. The target left this oplock
                               * as exlusive.... The process *must* be dead.... 
                               */

                              DEBUG(0,("open_mode_check: exlusive oplock left by process %d after break ! For file %s, \
dev = %x, inode = %.0f. Deleting it to continue...\n", (int)broken_entry.pid, fname, (unsigned int)dev, (double)inode));

                              if (process_exists(broken_entry.pid)) {
                                    DEBUG(0,("open_mode_check: Existent process %u left active oplock.\n",
                                                (unsigned int)broken_entry.pid ));
                              }

                              if (del_share_entry(dev, inode, &broken_entry, NULL) == -1) {
                                    errno = EACCES;
                                    unix_ERR_class = ERRDOS;
                                    unix_ERR_code = ERRbadshare;
                                    unix_ERR_ntstatus = NT_STATUS_SHARING_VIOLATION;
                                    return -1;
                              }

                              /*
                               * We must reload the share modes after deleting the 
                               * other process's entry.
                               */

                              SAFE_FREE(old_shares);
                              num_share_modes = get_share_modes(conn, dev, inode, &old_shares);
                              break;
                        }
                  } /* end for paranoia... */
            } /* end if broke_oplock */

      } while(broke_oplock);

      SAFE_FREE(old_shares);

      /*
       * Refuse to grant an oplock in case the contention limit is
       * reached when going through the lock list multiple times.
       */

      if(oplock_contention_count >= lp_oplock_contention_limit(SNUM(conn))) {
            *p_oplock_request = 0;
            DEBUG(4,("open_mode_check: oplock contention = %d. Not granting oplock.\n",
                        oplock_contention_count ));
      }

      return num_share_modes;
}

static BOOL open_match_attributes(connection_struct *conn, char *path, mode_t existing_mode,
            mode_t new_mode, mode_t *returned_mode)
{
      uint32 old_dos_mode, new_dos_mode;
      uint32 noarch_old_dos_mode, noarch_new_dos_mode;
      SMB_STRUCT_STAT sbuf;

      ZERO_STRUCT(sbuf);

      sbuf.st_mode = existing_mode;
      old_dos_mode = dos_mode(conn, path, &sbuf);

      sbuf.st_mode = new_mode;
      new_dos_mode = dos_mode(conn, path, &sbuf);

      noarch_old_dos_mode = (old_dos_mode & ~FILE_ATTRIBUTE_ARCHIVE);
      noarch_new_dos_mode = (new_dos_mode & ~FILE_ATTRIBUTE_ARCHIVE);

      if((noarch_old_dos_mode == 0 && noarch_new_dos_mode != 0) || 
         (noarch_old_dos_mode != 0 && ((noarch_old_dos_mode & noarch_new_dos_mode) == noarch_old_dos_mode)))
            *returned_mode = new_mode;
      else
            *returned_mode = (mode_t)0;

      DEBUG(10,("open_match_attributes: file %s old_dos_mode = 0x%x, existing_mode = 0%o, new_dos_mode = 0x%x returned_mode = 0%o\n",
            path,
            old_dos_mode, (unsigned int)existing_mode, new_dos_mode, (unsigned int)*returned_mode ));

      /* If we're mapping SYSTEM and HIDDEN ensure they match. */
      if (lp_map_system(SNUM(conn))) {
            if ((old_dos_mode & FILE_ATTRIBUTE_SYSTEM) && !(new_dos_mode & FILE_ATTRIBUTE_SYSTEM))
                  return False;
      }
      if (lp_map_hidden(SNUM(conn))) {
            if ((old_dos_mode & FILE_ATTRIBUTE_HIDDEN) && !(new_dos_mode & FILE_ATTRIBUTE_HIDDEN))
                  return False;
      }
      return True;
}

/****************************************************************************
set a kernel flock on a file for NFS interoperability
this requires a patch to Linux
****************************************************************************/
static void kernel_flock(files_struct *fsp, int deny_mode)
{
#if HAVE_KERNEL_SHARE_MODES
      int kernel_mode = 0;
      if (deny_mode == DENY_READ) kernel_mode = LOCK_MAND|LOCK_WRITE;
      else if (deny_mode == DENY_WRITE) kernel_mode = LOCK_MAND|LOCK_READ;
      else if (deny_mode == DENY_ALL) kernel_mode = LOCK_MAND;
      if (kernel_mode) flock(fsp->fd, kernel_mode);
#endif
      ;;
}


/****************************************************************************
 Open a file with a share mode - old method.
****************************************************************************/

files_struct *open_file_shared(connection_struct *conn,char *fname, SMB_STRUCT_STAT *psbuf, 
            int share_mode,int ofun, mode_t mode,int oplock_request, int *Access,int *action)
{
      return open_file_shared1(conn, fname, psbuf, 0, share_mode, ofun, mode,
                  oplock_request, Access, action);
}

/****************************************************************************
 Open a file with a share mode - called from NTCreateAndX.
****************************************************************************/

files_struct *open_file_shared1(connection_struct *conn,char *fname, SMB_STRUCT_STAT *psbuf, 
                        uint32 desired_access,
                        int share_mode,int ofun, mode_t mode,int oplock_request,
                        int *Access,int *action)
{
      int flags=0;
      int flags2=0;
      int deny_mode = GET_DENY_MODE(share_mode);
      BOOL allow_share_delete = GET_ALLOW_SHARE_DELETE(share_mode);
      BOOL delete_on_close = GET_DELETE_ON_CLOSE_FLAG(share_mode);
      BOOL file_existed = VALID_STAT(*psbuf);
      BOOL fcbopen = False;
      BOOL def_acl = False;
      SMB_DEV_T dev = 0;
      SMB_INO_T inode = 0;
      int num_share_modes = 0;
      BOOL all_current_opens_are_level_II = False;
      BOOL fsp_open = False;
      files_struct *fsp = NULL;
      int open_mode=0;
      uint16 port = 0;
      mode_t new_mode = (mode_t)0;
      pstring cvt_buf;

      if (conn->printer) {
            /* printers are handled completely differently. Most
                  of the passed parameters are ignored */
            if (Access)
                  *Access = DOS_OPEN_WRONLY;
            if (action)
                  *action = FILE_WAS_CREATED;
            return print_fsp_open(conn, fname);
      }

      fsp = file_new(conn);
      if(!fsp)
            return NULL;

      DEBUG(10,("open_file_shared: fname = %s, share_mode = %x, ofun = %x, mode = %o, oplock request = %d\n",
            fname, share_mode, ofun, (int)mode,  oplock_request ));

      if (!check_name(fname,conn)) {
            file_free(fsp);
            return NULL;
      } 

      /* ignore any oplock requests if oplocks are disabled */
      if (!lp_oplocks(SNUM(conn)) || global_client_failed_oplock_break) {
            oplock_request = 0;
      }

      /* this is for OS/2 EAs - try and say we don't support them */
      if (strstr(fname,".+,;=[].")) {
            unix_ERR_class = ERRDOS;
            /* OS/2 Workplace shell fix may be main code stream in a later release. */ 
#if 1 /* OS2_WPS_FIX - Recent versions of OS/2 need this. */
            unix_ERR_code = ERRcannotopen;
#else /* OS2_WPS_FIX */
            unix_ERR_code = ERROR_EAS_NOT_SUPPORTED;
#endif /* OS2_WPS_FIX */

            DEBUG(5,("open_file_shared: OS/2 EA's are not supported.\n"));
            file_free(fsp);
            return NULL;
      }

      if ((GET_FILE_OPEN_DISPOSITION(ofun) == FILE_EXISTS_FAIL) && file_existed)  {
            DEBUG(5,("open_file_shared: create new requested for file %s and file already exists.\n",
                  fname ));
            file_free(fsp);
            errno = EEXIST;
            return NULL;
      }
      
      if (CAN_WRITE(conn) && (GET_FILE_CREATE_DISPOSITION(ofun) == FILE_CREATE_IF_NOT_EXIST))
            flags2 |= O_CREAT;

      if (CAN_WRITE(conn) && (GET_FILE_OPEN_DISPOSITION(ofun) == FILE_EXISTS_TRUNCATE))
            flags2 |= O_TRUNC;

      /* We only care about matching attributes on file exists and truncate. */
      if (file_existed && (GET_FILE_OPEN_DISPOSITION(ofun) == FILE_EXISTS_TRUNCATE)) {
            if (!open_match_attributes(conn, fname, psbuf->st_mode, mode, &new_mode)) {
                  DEBUG(5,("open_file_shared: attributes missmatch for file %s (0%o, 0%o)\n",
                                    fname, psbuf->st_mode, mode ));
                  file_free(fsp);
                  errno = EACCES;
                  return NULL;
            }
      }

      if (GET_FILE_OPEN_DISPOSITION(ofun) == FILE_EXISTS_FAIL)
            flags2 |= O_EXCL;

      /* note that we ignore the append flag as 
            append does not mean the same thing under dos and unix */

      switch (GET_OPEN_MODE(share_mode)) {
            case DOS_OPEN_WRONLY: 
                  flags = O_WRONLY; 
                  if (desired_access == 0)
                        desired_access = FILE_WRITE_DATA;
                  break;
            case DOS_OPEN_FCB: 
                  fcbopen = True;
                  flags = O_RDWR; 
                  if (desired_access == 0)
                        desired_access = FILE_READ_DATA|FILE_WRITE_DATA;
                  break;
            case DOS_OPEN_RDWR: 
                  flags = O_RDWR; 
                  if (desired_access == 0)
                        desired_access = FILE_READ_DATA|FILE_WRITE_DATA;
                  break;
            default:
                  flags = O_RDONLY;
                  if (desired_access == 0)
                        desired_access = FILE_READ_DATA;
                  break;
      }

#if defined(O_SYNC)
      if (GET_FILE_SYNC_OPENMODE(share_mode)) {
            flags2 |= O_SYNC;
      }
#endif /* O_SYNC */
  
      if (flags != O_RDONLY && file_existed && 
                  (!CAN_WRITE(conn) || IS_DOS_READONLY(dos_mode(conn,fname,psbuf)))) {
            if (!fcbopen) {
                  DEBUG(5,("open_file_shared: read/write access requested for file %s on read only %s\n",
                        fname, !CAN_WRITE(conn) ? "share" : "file" ));
                  file_free(fsp);
                  errno = EACCES;
                  return NULL;
            }
            flags = O_RDONLY;
      }

      if (deny_mode > DENY_NONE && deny_mode!=DENY_FCB) {
            DEBUG(2,("Invalid deny mode %d on file %s\n",deny_mode,fname));
            file_free(fsp);
            errno = EINVAL;
            return NULL;
      }

      if (file_existed) {

            dev = psbuf->st_dev;
            inode = psbuf->st_ino;

            lock_share_entry(conn, dev, inode);

            num_share_modes = open_mode_check(conn, fname, dev, inode,
                                    desired_access, share_mode,
                                    &flags, &oplock_request, &all_current_opens_are_level_II);

            if(num_share_modes == -1) {

                  /*
                   * This next line is a subtlety we need for MS-Access. If a file open will
                   * fail due to share permissions and also for security (access)
                   * reasons, we need to return the access failed error, not the
                   * share error. This means we must attempt to open the file anyway
                   * in order to get the UNIX access error - even if we're going to
                   * fail the open for share reasons. This is bad, as we're burning
                   * another fd if there are existing locks but there's nothing else
                   * we can do. We also ensure we're not going to create or tuncate
                   * the file as we only want an access decision at this stage. JRA.
                   */
                  errno = 0;
                  fsp_open = open_file(fsp,conn,fname,psbuf,
                                    flags|(flags2&~(O_TRUNC|O_CREAT)),mode,desired_access);

                  DEBUG(4,("open_file_shared : share_mode deny - calling open_file with \
flags=0x%X flags2=0x%X mode=0%o returned %d\n",
                        flags,(flags2&~(O_TRUNC|O_CREAT)),(int)mode,(int)fsp_open ));

                  if (!fsp_open && errno) {
                        unix_ERR_class = ERRDOS;
                        unix_ERR_code = ERRnoaccess;
                        unix_ERR_ntstatus = NT_STATUS_ACCESS_DENIED;
                  }

                  unlock_share_entry(conn, dev, inode);
                  if (fsp_open)
                        fd_close(conn, fsp);
                  file_free(fsp);
                  return NULL;
            }

            /*
             * We exit this block with the share entry *locked*.....
             */
      }

      /*
       * Ensure we pay attention to default ACLs on directories if required.
       */

        if ((flags2 & O_CREAT) && lp_inherit_acls(SNUM(conn)) &&
                  (def_acl = directory_has_default_acl(conn, dos_to_unix(cvt_buf, parent_dirname(fname)))))
                mode = 0777;

      DEBUG(4,("calling open_file with flags=0x%X flags2=0x%X mode=0%o\n",
                  flags,flags2,(int)mode));

      /*
       * open_file strips any O_TRUNC flags itself.
       */

      fsp_open = open_file(fsp,conn,fname,psbuf,flags|flags2,mode,desired_access);

      if (!fsp_open && (flags == O_RDWR) && (errno != ENOENT) && fcbopen) {
            if((fsp_open = open_file(fsp,conn,fname,psbuf,O_RDONLY,mode,desired_access)) == True)
                  flags = O_RDONLY;
      }

      if (!fsp_open) {
            if(file_existed)
                  unlock_share_entry(conn, dev, inode);
            file_free(fsp);
            return NULL;
      }

      /*
       * Deal with the race condition where two smbd's detect the file doesn't
       * exist and do the create at the same time. One of them will win and
       * set a share mode, the other (ie. this one) should check if the
       * requested share mode for this create is allowed.
       */

      if (!file_existed) { 

            lock_share_entry_fsp(fsp);

            num_share_modes = open_mode_check(conn, fname, dev, inode,
                                    desired_access, share_mode,
                                    &flags, &oplock_request, &all_current_opens_are_level_II);

            if(num_share_modes == -1) {
                  unlock_share_entry_fsp(fsp);
                  fd_close(conn,fsp);
                  file_free(fsp);
                  return NULL;
            }

            /*
             * If there are any share modes set then the file *did*
             * exist. Ensure we return the correct value for action.
             */

            if (num_share_modes > 0)
                  file_existed = True;

            /*
             * We exit this block with the share entry *locked*.....
             */
      }

      /* note that we ignore failure for the following. It is
           basically a hack for NFS, and NFS will never set one of
           these only read them. Nobody but Samba can ever set a deny
           mode and we have already checked our more authoritative
           locking database for permission to set this deny mode. If
           the kernel refuses the operations then the kernel is wrong */
      kernel_flock(fsp, deny_mode);

      /*
       * At this point onwards, we can guarentee that the share entry
       * is locked, whether we created the file or not, and that the
       * deny mode is compatible with all current opens.
       */

      /*
       * If requested, truncate the file.
       */

      if (flags2&O_TRUNC) {
            /*
             * We are modifing the file after open - update the stat struct..
             */
            if ((truncate_unless_locked(conn,fsp) == -1) || (vfs_fstat(fsp,fsp->fd,psbuf)==-1)) {
                  unlock_share_entry_fsp(fsp);
                  fd_close(conn,fsp);
                  file_free(fsp);
                  return NULL;
            }
      }

      switch (flags) {
            case O_RDONLY:
                  open_mode = DOS_OPEN_RDONLY;
                  break;
            case O_RDWR:
                  open_mode = DOS_OPEN_RDWR;
                  break;
            case O_WRONLY:
                  open_mode = DOS_OPEN_WRONLY;
                  break;
      }

      fsp->share_mode = SET_DENY_MODE(deny_mode) | 
                                    SET_OPEN_MODE(open_mode) | 
                                    SET_ALLOW_SHARE_DELETE(allow_share_delete);

      DEBUG(10,("open_file_shared : share_mode = %x\n", fsp->share_mode ));

      if (Access)
            (*Access) = open_mode;

      if (action) {
            if (file_existed && !(flags2 & O_TRUNC))
                  *action = FILE_WAS_OPENED;
            if (!file_existed)
                  *action = FILE_WAS_CREATED;
            if (file_existed && (flags2 & O_TRUNC))
                  *action = FILE_WAS_OVERWRITTEN;
      }

      /* 
       * Setup the oplock info in both the shared memory and
       * file structs.
       */

      if(oplock_request && (num_share_modes == 0) && 
                  !IS_VETO_OPLOCK_PATH(conn,fname) && set_file_oplock(fsp, oplock_request) ) {
            port = global_oplock_port;
      } else if (oplock_request && all_current_opens_are_level_II) {
            port = global_oplock_port;
            oplock_request = LEVEL_II_OPLOCK;
            set_file_oplock(fsp, oplock_request);
      } else {
            port = 0;
            oplock_request = 0;
      }

      set_share_mode(fsp, port, oplock_request);

      if (delete_on_close) {
            NTSTATUS result = set_delete_on_close_internal(fsp, delete_on_close);

            if (NT_STATUS_V(result) !=  NT_STATUS_V(NT_STATUS_OK)) {
                  /* Remember to delete the mode we just added. */
                  del_share_mode(fsp, NULL);
                  unlock_share_entry_fsp(fsp);
                  fd_close(conn,fsp);
                  file_free(fsp);
                  return NULL;
            }
      }
      
      /*
       * Take care of inherited ACLs on created files - if default ACL not
       * selected.
       */

      if (!file_existed && !def_acl && (conn->vfs_ops.fchmod_acl != NULL)) {

            int saved_errno = errno; /* We might get ENOSYS in the next call.. */

            if (conn->vfs_ops.fchmod_acl(fsp, fsp->fd, mode) == -1 && errno == ENOSYS)
                  errno = saved_errno; /* Ignore ENOSYS */

      } else if (new_mode) {

            int ret = -1;

            /* Attributes need changing. File already existed. */

            if (conn->vfs_ops.fchmod_acl != NULL) {
                  int saved_errno = errno; /* We might get ENOSYS in the next call.. */
                  ret = conn->vfs_ops.fchmod_acl(fsp, fsp->fd, new_mode);

                  if (ret == -1 && errno == ENOSYS) {
                        errno = saved_errno; /* Ignore ENOSYS */
                  } else {
                        DEBUG(5, ("open_file_shared: failed to reset attributes of file %s to 0%o\n",
                              fname, (int)new_mode));
                        ret = 0; /* Don't do the fchmod below. */
                  }
            }

            if ((ret == -1) && (conn->vfs_ops.fchmod(fsp, fsp->fd, new_mode) == -1))
                  DEBUG(5, ("open_file_shared: failed to reset attributes of file %s to 0%o\n",
                        fname, (int)new_mode));
      }

      unlock_share_entry_fsp(fsp);

      conn->num_files_open++;

      return fsp;
}

/****************************************************************************
 Open a file for for write to ensure that we can fchmod it.
****************************************************************************/

files_struct *open_file_fchmod(connection_struct *conn, const char *fname, SMB_STRUCT_STAT *psbuf)
{
      files_struct *fsp = NULL;
      BOOL fsp_open;

      if (!VALID_STAT(*psbuf))
            return NULL;

      fsp = file_new(conn);
      if(!fsp)
            return NULL;

      /* note! we must use a non-zero desired access or we don't get
           a real file descriptor. Oh what a twisted web we weave. */
      fsp_open = open_file(fsp,conn,fname,psbuf,O_WRONLY,0,FILE_WRITE_DATA);

      /* 
       * This is not a user visible file open.
       * Don't set a share mode and don't increment
       * the conn->num_files_open.
       */

      if (!fsp_open) {
            file_free(fsp);
            return NULL;
      }

      return fsp;
}

/****************************************************************************
 Close the fchmod file fd - ensure no locks are lost.
****************************************************************************/

int close_file_fchmod(files_struct *fsp)
{
      int ret = fd_close(fsp->conn, fsp);
      file_free(fsp);
      return ret;
}

/****************************************************************************
 Open a directory from an NT SMB call.
****************************************************************************/

files_struct *open_directory(connection_struct *conn, char *fname, SMB_STRUCT_STAT *psbuf,
                  uint32 desired_access, int share_mode, int smb_ofun, mode_t unixmode, int *action)
{
      extern struct current_user current_user;
      BOOL got_stat = False;
      files_struct *fsp = file_new(conn);
      pstring cvt_buf;
      BOOL delete_on_close = GET_DELETE_ON_CLOSE_FLAG(share_mode);

      if(!fsp)
            return NULL;

      fsp->conn = conn; /* The vfs_fXXX() macros need this. */

      if (VALID_STAT(*psbuf))
            got_stat = True;

      if (got_stat && (GET_FILE_OPEN_DISPOSITION(smb_ofun) == FILE_EXISTS_FAIL)) {
            file_free(fsp);
            errno = EEXIST; /* Setup so correct error is returned to client. */
            return NULL;
      }

      if (GET_FILE_CREATE_DISPOSITION(smb_ofun) == FILE_CREATE_IF_NOT_EXIST) {

            if (got_stat) {

                  if(!S_ISDIR(psbuf->st_mode)) {
                        DEBUG(0,("open_directory: %s is not a directory !\n", fname ));
                        file_free(fsp);
                        errno = EACCES;
                        return NULL;
                  }
                  *action = FILE_WAS_OPENED;

            } else {

                  /*
                   * Try and create the directory.
                   */

                  if(!CAN_WRITE(conn)) {
                        DEBUG(2,("open_directory: failing create on read-only share\n"));
                        file_free(fsp);
                        errno = EACCES;
                        return NULL;
                  }

                  if(vfs_mkdir(conn,fname, unix_mode(conn,aDIR, fname)) < 0) {
                        DEBUG(2,("open_directory: unable to create %s. Error was %s\n",
                               fname, strerror(errno) ));
                        file_free(fsp);
                        return NULL;
                  }

                  if(vfs_stat(conn,fname, psbuf, cvt_buf) != 0) {
                        file_free(fsp);
                        return NULL;
                  }

                  *action = FILE_WAS_CREATED;

            }
      } else {

            /*
             * Don't create - just check that it *was* a directory.
             */

            if(!got_stat) {
                  DEBUG(0,("open_directory: unable to stat name = %s. Error was %s\n",
                         fname, strerror(errno) ));
                  file_free(fsp);
                  return NULL;
            }

            if(!S_ISDIR(psbuf->st_mode)) {
                  DEBUG(0,("open_directory: %s is not a directory !\n", fname ));
                  file_free(fsp);
                  return NULL;
            }

            *action = FILE_WAS_OPENED;
      }
      
      DEBUG(5,("open_directory: opening directory %s\n", fname));

      /*
       * Setup the files_struct for it.
       */
      
      fsp->mode = psbuf->st_mode;
      fsp->inode = psbuf->st_ino;
      fsp->dev = psbuf->st_dev;
      fsp->size = psbuf->st_size;
      fsp->vuid = current_user.vuid;
      fsp->pos = -1;
      fsp->can_lock = True;
      fsp->can_read = False;
      fsp->can_write = False;
      fsp->share_mode = share_mode;
      fsp->desired_access = desired_access;
      fsp->print_file = False;
      fsp->modified = False;
      fsp->oplock_type = NO_OPLOCK;
      fsp->sent_oplock_break = NO_BREAK_SENT;
      fsp->is_directory = True;
      fsp->directory_delete_on_close = False;
      fsp->conn = conn;

      if (delete_on_close) {
            NTSTATUS result = set_delete_on_close_internal(fsp, delete_on_close);

            if (NT_STATUS_V(result) !=  NT_STATUS_V(NT_STATUS_OK)) {
                  file_free(fsp);
                  return NULL;
            }
      }
      
      /*
       * Note that the file name here is the *untranslated* name
       * ie. it is still in the DOS codepage sent from the client.
       * All use of this filename will pass though the sys_xxxx
       * functions which will do the dos_to_unix translation before
       * mapping into a UNIX filename. JRA.
       */
      string_set(&fsp->fsp_name,fname);
      fsp->wbmpx_ptr = NULL;

      conn->num_files_open++;

      return fsp;
}

/****************************************************************************
 Open a pseudo-file (no locking checks - a 'stat' open).
****************************************************************************/

files_struct *open_file_stat(connection_struct *conn, char *fname, SMB_STRUCT_STAT *psbuf)
{
      extern struct current_user current_user;
      files_struct *fsp = NULL;

      if (!VALID_STAT(*psbuf))
            return NULL;

      /* Can't 'stat' open directories. */
      if(S_ISDIR(psbuf->st_mode))
            return NULL;

      fsp = file_new(conn);
      if(!fsp)
            return NULL;

      fsp->conn = conn; /* The vfs_fXXX() macros need this. */

      DEBUG(5,("open_file_stat: 'opening' file %s\n", fname));

      /*
       * Setup the files_struct for it.
       */
      
      fsp->mode = psbuf->st_mode;
      /* 
       * Don't store dev or inode, we don't want any iterator
       * to see this.
       */
      fsp->inode = (SMB_INO_T)0;
      fsp->dev = (SMB_DEV_T)0;
      fsp->size = psbuf->st_size;
      fsp->vuid = current_user.vuid;
      fsp->pos = -1;
      fsp->can_lock = False;
      fsp->can_read = False;
      fsp->can_write = False;
      fsp->share_mode = 0;
      fsp->desired_access = 0;
      fsp->print_file = False;
      fsp->modified = False;
      fsp->oplock_type = NO_OPLOCK;
      fsp->sent_oplock_break = NO_BREAK_SENT;
      fsp->is_directory = False;
      fsp->is_stat = True;
      fsp->directory_delete_on_close = False;
      fsp->conn = conn;
      string_set(&fsp->fsp_name,fname);

      conn->num_files_open++;

      return fsp;
}

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