1 /* $Cambridge: exim/src/src/lookups/lf_check_file.c,v 1.5 2009/11/16 19:50:38 nm4 Exp $ */
3 /*************************************************
4 * Exim - an Internet mail transport agent *
5 *************************************************/
7 /* Copyright (c) University of Cambridge 1995 - 2009 */
8 /* See the file NOTICE for conditions of use and distribution. */
12 #include "lf_functions.h"
16 /*************************************************
17 * Check a file's credentials *
18 *************************************************/
20 /* fstat can normally be expected to work on an open file, but there are some
21 NFS states where it may not.
24 fd an open file descriptor or -1
25 filename a file name if fd is -1
26 s_type type of file (S_IFREG or S_IFDIR)
27 modemask a mask specifying mode bits that must *not* be set
28 owners NULL or a list of of allowable uids, count in the first item
29 owngroups NULL or a list of allowable gids, count in the first item
30 type name of lookup type for putting in error message
31 errmsg where to put an error message
33 Returns: -1 stat() or fstat() failed
35 +1 something didn't match
37 Side effect: sets errno to ERRNO_BADUGID, ERRNO_NOTREGULAR or ERRNO_BADMODE for
38 bad uid/gid, not a regular file, or bad mode; otherwise leaves it
39 to what fstat set it to.
43 lf_check_file(int fd
, uschar
*filename
, int s_type
, int modemask
, uid_t
*owners
,
44 gid_t
*owngroups
, char *type
, uschar
**errmsg
)
49 if ((fd
>= 0 && fstat(fd
, &statbuf
) != 0) ||
50 (fd
< 0 && Ustat(filename
, &statbuf
) != 0))
52 int save_errno
= errno
;
53 *errmsg
= string_sprintf("%s: stat failed", filename
);
58 if ((statbuf
.st_mode
& S_IFMT
) != s_type
)
60 if (s_type
== S_IFREG
)
62 *errmsg
= string_sprintf("%s is not a regular file (%s lookup)",
64 errno
= ERRNO_NOTREGULAR
;
68 *errmsg
= string_sprintf("%s is not a directory (%s lookup)",
70 errno
= ERRNO_NOTDIRECTORY
;
75 if ((statbuf
.st_mode
& modemask
) != 0)
77 *errmsg
= string_sprintf("%s (%s lookup): file mode %.4o should not contain "
78 "%.4o", filename
, type
, statbuf
.st_mode
& 07777,
79 statbuf
.st_mode
& modemask
);
80 errno
= ERRNO_BADMODE
;
87 for (i
= 1; i
<= (int)owners
[0]; i
++)
88 if (owners
[i
] == statbuf
.st_uid
) { uid_ok
= TRUE
; break; }
91 *errmsg
= string_sprintf("%s (%s lookup): file has wrong owner", filename
,
93 errno
= ERRNO_BADUGID
;
98 if (owngroups
!= NULL
)
101 for (i
= 1; i
<= (int)owngroups
[0]; i
++)
102 if (owngroups
[i
] == statbuf
.st_gid
) { gid_ok
= TRUE
; break; }
105 *errmsg
= string_sprintf("%s (%s lookup): file has wrong group", filename
,
107 errno
= ERRNO_BADUGID
;
115 /* End of lf_check_file.c */