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184e8823 | 1 | /* $Cambridge: exim/src/src/lookups/lf_check_file.c,v 1.4 2007/01/08 10:50:19 ph10 Exp $ */ |
0756eb3c PH |
2 | |
3 | /************************************************* | |
4 | * Exim - an Internet mail transport agent * | |
5 | *************************************************/ | |
6 | ||
184e8823 | 7 | /* Copyright (c) University of Cambridge 1995 - 2007 */ |
0756eb3c PH |
8 | /* See the file NOTICE for conditions of use and distribution. */ |
9 | ||
10 | ||
11 | #include "../exim.h" | |
12 | #include "lf_functions.h" | |
13 | ||
14 | ||
15 | ||
16 | /************************************************* | |
17 | * Check a file's credentials * | |
18 | *************************************************/ | |
19 | ||
20 | /* fstat can normally be expected to work on an open file, but there are some | |
21 | NFS states where it may not. | |
22 | ||
23 | Arguments: | |
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 | |
32 | ||
33 | Returns: -1 stat() or fstat() failed | |
34 | 0 OK | |
35 | +1 something didn't match | |
36 | ||
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. | |
40 | */ | |
41 | ||
42 | int | |
43 | lf_check_file(int fd, uschar *filename, int s_type, int modemask, uid_t *owners, | |
44 | gid_t *owngroups, char *type, uschar **errmsg) | |
45 | { | |
46 | int i; | |
47 | struct stat statbuf; | |
48 | ||
49 | if ((fd >= 0 && fstat(fd, &statbuf) != 0) || | |
50 | (fd < 0 && Ustat(filename, &statbuf) != 0)) | |
51 | { | |
52 | int save_errno = errno; | |
53 | *errmsg = string_sprintf("%s: stat failed", filename); | |
54 | errno = save_errno; | |
55 | return -1; | |
56 | } | |
57 | ||
58 | if ((statbuf.st_mode & S_IFMT) != s_type) | |
59 | { | |
60 | if (s_type == S_IFREG) | |
61 | { | |
62 | *errmsg = string_sprintf("%s is not a regular file (%s lookup)", | |
63 | filename, type); | |
64 | errno = ERRNO_NOTREGULAR; | |
65 | } | |
66 | else | |
67 | { | |
68 | *errmsg = string_sprintf("%s is not a directory (%s lookup)", | |
69 | filename, type); | |
70 | errno = ERRNO_NOTDIRECTORY; | |
71 | } | |
72 | return +1; | |
73 | } | |
74 | ||
75 | if ((statbuf.st_mode & modemask) != 0) | |
76 | { | |
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; | |
81 | return +1; | |
82 | } | |
83 | ||
84 | if (owners != NULL) | |
85 | { | |
86 | BOOL uid_ok = FALSE; | |
87 | for (i = 1; i <= (int)owners[0]; i++) | |
88 | if (owners[i] == statbuf.st_uid) { uid_ok = TRUE; break; } | |
89 | if (!uid_ok) | |
90 | { | |
91 | *errmsg = string_sprintf("%s (%s lookup): file has wrong owner", filename, | |
92 | type); | |
93 | errno = ERRNO_BADUGID; | |
94 | return +1; | |
95 | } | |
96 | } | |
97 | ||
98 | if (owngroups != NULL) | |
99 | { | |
100 | BOOL gid_ok = FALSE; | |
101 | for (i = 1; i <= (int)owngroups[0]; i++) | |
102 | if (owngroups[i] == statbuf.st_gid) { gid_ok = TRUE; break; } | |
103 | if (!gid_ok) | |
104 | { | |
105 | *errmsg = string_sprintf("%s (%s lookup): file has wrong group", filename, | |
106 | type); | |
107 | errno = ERRNO_BADUGID; | |
108 | return +1; | |
109 | } | |
110 | } | |
111 | ||
112 | return 0; | |
113 | } | |
114 | ||
115 | /* End of lf_check_file.c */ |