OpenSSL: under resumption open ticket DB writable, for record delete
[exim.git] / src / src / lookups / lf_check_file.c
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1/*************************************************
2* Exim - an Internet mail transport agent *
3*************************************************/
4
0a49a7a4 5/* Copyright (c) University of Cambridge 1995 - 2009 */
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6/* See the file NOTICE for conditions of use and distribution. */
7
8
9#include "../exim.h"
10#include "lf_functions.h"
11
12
13
14/*************************************************
15* Check a file's credentials *
16*************************************************/
17
18/* fstat can normally be expected to work on an open file, but there are some
19NFS states where it may not.
20
21Arguments:
22 fd an open file descriptor or -1
23 filename a file name if fd is -1
24 s_type type of file (S_IFREG or S_IFDIR)
25 modemask a mask specifying mode bits that must *not* be set
26 owners NULL or a list of of allowable uids, count in the first item
27 owngroups NULL or a list of allowable gids, count in the first item
28 type name of lookup type for putting in error message
29 errmsg where to put an error message
30
31Returns: -1 stat() or fstat() failed
32 0 OK
33 +1 something didn't match
34
35Side effect: sets errno to ERRNO_BADUGID, ERRNO_NOTREGULAR or ERRNO_BADMODE for
36 bad uid/gid, not a regular file, or bad mode; otherwise leaves it
37 to what fstat set it to.
38*/
39
40int
41lf_check_file(int fd, uschar *filename, int s_type, int modemask, uid_t *owners,
1ba28e2b 42 gid_t *owngroups, const char *type, uschar **errmsg)
0756eb3c 43{
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44struct stat statbuf;
45
46if ((fd >= 0 && fstat(fd, &statbuf) != 0) ||
47 (fd < 0 && Ustat(filename, &statbuf) != 0))
48 {
49 int save_errno = errno;
50 *errmsg = string_sprintf("%s: stat failed", filename);
51 errno = save_errno;
52 return -1;
53 }
54
55if ((statbuf.st_mode & S_IFMT) != s_type)
56 {
57 if (s_type == S_IFREG)
58 {
59 *errmsg = string_sprintf("%s is not a regular file (%s lookup)",
60 filename, type);
61 errno = ERRNO_NOTREGULAR;
62 }
63 else
64 {
65 *errmsg = string_sprintf("%s is not a directory (%s lookup)",
66 filename, type);
67 errno = ERRNO_NOTDIRECTORY;
68 }
69 return +1;
70 }
71
72if ((statbuf.st_mode & modemask) != 0)
73 {
74 *errmsg = string_sprintf("%s (%s lookup): file mode %.4o should not contain "
75 "%.4o", filename, type, statbuf.st_mode & 07777,
76 statbuf.st_mode & modemask);
77 errno = ERRNO_BADMODE;
78 return +1;
79 }
80
81if (owners != NULL)
82 {
83 BOOL uid_ok = FALSE;
d7978c0f 84 for (int i = 1; i <= (int)owners[0]; i++)
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85 if (owners[i] == statbuf.st_uid) { uid_ok = TRUE; break; }
86 if (!uid_ok)
87 {
88 *errmsg = string_sprintf("%s (%s lookup): file has wrong owner", filename,
89 type);
90 errno = ERRNO_BADUGID;
91 return +1;
92 }
93 }
94
95if (owngroups != NULL)
96 {
97 BOOL gid_ok = FALSE;
d7978c0f 98 for (int i = 1; i <= (int)owngroups[0]; i++)
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99 if (owngroups[i] == statbuf.st_gid) { gid_ok = TRUE; break; }
100 if (!gid_ok)
101 {
102 *errmsg = string_sprintf("%s (%s lookup): file has wrong group", filename,
103 type);
104 errno = ERRNO_BADUGID;
105 return +1;
106 }
107 }
108
109return 0;
110}
111
112/* End of lf_check_file.c */