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Diffstat (limited to 'gnu/libexec/uucp/libunix/move.c')
| -rw-r--r-- | gnu/libexec/uucp/libunix/move.c | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/gnu/libexec/uucp/libunix/move.c b/gnu/libexec/uucp/libunix/move.c new file mode 100644 index 000000000000..ccfe6d4d728d --- /dev/null +++ b/gnu/libexec/uucp/libunix/move.c @@ -0,0 +1,176 @@ +/* move.c + Move a file. + + Copyright (C) 1991, 1992 Ian Lance Taylor + + This file is part of the Taylor UUCP package. + + 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. + + The author of the program may be contacted at ian@airs.com or + c/o Infinity Development Systems, P.O. Box 520, Waltham, MA 02254. + */ + +#include "uucp.h" + +#include "uudefs.h" +#include "sysdep.h" +#include "system.h" + +#include <errno.h> + +#if HAVE_FCNTL_H +#include <fcntl.h> +#else +#if HAVE_SYS_FILE_H +#include <sys/file.h> +#endif +#endif + +/* Move (rename) a file from one name to another. This routine will + optionally create necessary directories, and fpublic indicates + whether the new directories should be publically accessible or not. + If fcheck is true, it will try to determine whether the named user + has write access to the new file. */ + +boolean +fsysdep_move_file (zorig, zto, fmkdirs, fpublic, fcheck, zuser) + const char *zorig; + const char *zto; + boolean fmkdirs; + boolean fpublic; + boolean fcheck; + const char *zuser; +{ + struct stat s; + int o; + + DEBUG_MESSAGE2 (DEBUG_SPOOLDIR, + "fsysdep_move_file: Moving %s to %s", zorig, zto); + + /* Optionally make sure that zuser has write access on the + directory. */ + if (fcheck) + { + char *zcopy; + char *zslash; + + zcopy = zbufcpy (zto); + zslash = strrchr (zcopy, '/'); + if (zslash == zcopy) + zslash[1] = '\0'; + else + *zslash = '\0'; + + if (stat (zcopy, &s) != 0) + { + ulog (LOG_ERROR, "stat (%s): %s", zcopy, strerror (errno)); + (void) remove (zorig); + ubuffree (zcopy); + return FALSE; + } + if (! fsuser_access (&s, W_OK, zuser)) + { + ulog (LOG_ERROR, "%s: %s", zcopy, strerror (EACCES)); + (void) remove (zorig); + ubuffree (zcopy); + return FALSE; + } + ubuffree (zcopy); + + /* A malicious user now has a few milliseconds to change a + symbolic link to a directory uucp has write permission on but + the user does not (the obvious choice being /usr/lib/uucp). + The only certain method I can come up with to close this race + is to fork an suid process which takes on the users identity + and does the actual copy. This is sufficiently high overhead + that I'm not going to do it. */ + } + + /* We try to use rename to move the file. */ + + if (rename (zorig, zto) == 0) + return TRUE; + + if (fmkdirs && errno == ENOENT) + { + if (! fsysdep_make_dirs (zto, fpublic)) + { + (void) remove (zorig); + return FALSE; + } + if (rename (zorig, zto) == 0) + return TRUE; + } + +#if HAVE_RENAME + /* On some systems the system call rename seems to fail for + arbitrary reasons. To get around this, we always try to copy the + file by hand if the rename failed. */ + errno = EXDEV; +#endif + + /* If we can't link across devices, we must copy the file by hand. */ + if (errno != EXDEV) + { + ulog (LOG_ERROR, "rename (%s, %s): %s", zorig, zto, + strerror (errno)); + (void) remove (zorig); + return FALSE; + } + + /* Copy the file. */ + if (stat ((char *) zorig, &s) < 0) + { + ulog (LOG_ERROR, "stat (%s): %s", zorig, strerror (errno)); + (void) remove (zorig); + return FALSE; + } + + /* Make sure the file gets the right mode by creating it before we + call fcopy_file. */ + (void) remove (zto); + o = creat ((char *) zto, s.st_mode); + if (o < 0) + { + if (fmkdirs && errno == ENOENT) + { + if (! fsysdep_make_dirs (zto, fpublic)) + { + (void) remove (zorig); + return FALSE; + } + o = creat ((char *) zto, s.st_mode); + } + if (o < 0) + { + ulog (LOG_ERROR, "creat (%s): %s", zto, strerror (errno)); + (void) remove (zorig); + return FALSE; + } + } + (void) close (o); + + if (! fcopy_file (zorig, zto, fpublic, fmkdirs)) + { + (void) remove (zorig); + return FALSE; + } + + if (remove (zorig) != 0) + ulog (LOG_ERROR, "remove (%s): %s", zorig, strerror (errno)); + + return TRUE; +} |