177 lines
4.4 KiB
C
177 lines
4.4 KiB
C
/* move.c
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Move a file.
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Copyright (C) 1991, 1992 Ian Lance Taylor
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This file is part of the Taylor UUCP package.
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This program is free software; you can redistribute it and/or
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modify it under the terms of the GNU General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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This program is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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The author of the program may be contacted at ian@airs.com or
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c/o Infinity Development Systems, P.O. Box 520, Waltham, MA 02254.
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*/
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#include "uucp.h"
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#include "uudefs.h"
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#include "sysdep.h"
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#include "system.h"
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#include <errno.h>
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#if HAVE_FCNTL_H
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#include <fcntl.h>
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#else
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#if HAVE_SYS_FILE_H
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#include <sys/file.h>
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#endif
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#endif
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/* Move (rename) a file from one name to another. This routine will
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optionally create necessary directories, and fpublic indicates
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whether the new directories should be publically accessible or not.
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If fcheck is true, it will try to determine whether the named user
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has write access to the new file. */
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boolean
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fsysdep_move_file (zorig, zto, fmkdirs, fpublic, fcheck, zuser)
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const char *zorig;
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const char *zto;
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boolean fmkdirs;
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boolean fpublic;
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boolean fcheck;
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const char *zuser;
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{
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struct stat s;
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int o;
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DEBUG_MESSAGE2 (DEBUG_SPOOLDIR,
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"fsysdep_move_file: Moving %s to %s", zorig, zto);
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/* Optionally make sure that zuser has write access on the
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directory. */
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if (fcheck)
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{
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char *zcopy;
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char *zslash;
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zcopy = zbufcpy (zto);
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zslash = strrchr (zcopy, '/');
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if (zslash == zcopy)
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zslash[1] = '\0';
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else
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*zslash = '\0';
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if (stat (zcopy, &s) != 0)
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{
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ulog (LOG_ERROR, "stat (%s): %s", zcopy, strerror (errno));
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(void) remove (zorig);
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ubuffree (zcopy);
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return FALSE;
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}
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if (! fsuser_access (&s, W_OK, zuser))
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{
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ulog (LOG_ERROR, "%s: %s", zcopy, strerror (EACCES));
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(void) remove (zorig);
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ubuffree (zcopy);
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return FALSE;
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}
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ubuffree (zcopy);
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/* A malicious user now has a few milliseconds to change a
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symbolic link to a directory uucp has write permission on but
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the user does not (the obvious choice being /usr/lib/uucp).
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The only certain method I can come up with to close this race
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is to fork an suid process which takes on the users identity
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and does the actual copy. This is sufficiently high overhead
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that I'm not going to do it. */
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}
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/* We try to use rename to move the file. */
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if (rename (zorig, zto) == 0)
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return TRUE;
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if (fmkdirs && errno == ENOENT)
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{
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if (! fsysdep_make_dirs (zto, fpublic))
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{
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(void) remove (zorig);
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return FALSE;
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}
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if (rename (zorig, zto) == 0)
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return TRUE;
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}
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#if HAVE_RENAME
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/* On some systems the system call rename seems to fail for
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arbitrary reasons. To get around this, we always try to copy the
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file by hand if the rename failed. */
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errno = EXDEV;
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#endif
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/* If we can't link across devices, we must copy the file by hand. */
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if (errno != EXDEV)
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{
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ulog (LOG_ERROR, "rename (%s, %s): %s", zorig, zto,
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strerror (errno));
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(void) remove (zorig);
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return FALSE;
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}
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/* Copy the file. */
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if (stat ((char *) zorig, &s) < 0)
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{
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ulog (LOG_ERROR, "stat (%s): %s", zorig, strerror (errno));
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(void) remove (zorig);
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return FALSE;
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}
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/* Make sure the file gets the right mode by creating it before we
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call fcopy_file. */
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(void) remove (zto);
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o = creat ((char *) zto, s.st_mode);
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if (o < 0)
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{
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if (fmkdirs && errno == ENOENT)
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{
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if (! fsysdep_make_dirs (zto, fpublic))
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{
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(void) remove (zorig);
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return FALSE;
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}
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o = creat ((char *) zto, s.st_mode);
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}
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if (o < 0)
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{
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ulog (LOG_ERROR, "creat (%s): %s", zto, strerror (errno));
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(void) remove (zorig);
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return FALSE;
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}
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}
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(void) close (o);
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if (! fcopy_file (zorig, zto, fpublic, fmkdirs))
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{
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(void) remove (zorig);
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return FALSE;
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}
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if (remove (zorig) != 0)
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ulog (LOG_ERROR, "remove (%s): %s", zorig, strerror (errno));
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return TRUE;
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}
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