1 /* $NetBSD: lstat_as.c,v 1.1.1.2 2013/01/02 18:59:13 tron Exp $ */
2
3 /*++
4 /* NAME
5 /* lstat_as 3
6 /* SUMMARY
7 /* lstat file as user
8 /* SYNOPSIS
9 /* #include <sys/stat.h>
10 /* #include <lstat_as.h>
11 /*
12 /* int lstat_as(path, st, euid, egid)
13 /* const char *path;
14 /* struct stat *st;
15 /* uid_t euid;
16 /* gid_t egid;
17 /* DESCRIPTION
18 /* lstat_as() looks up the file status of the named \fIpath\fR,
19 /* using the effective rights specified by \fIeuid\fR
20 /* and \fIegid\fR, and stores the result into the structure pointed
21 /* to by \fIst\fR. A -1 result means the lookup failed.
22 /* This call does not follow symbolic links.
23 /* DIAGNOSTICS
24 /* Fatal error: no permission to change privilege level.
25 /* SEE ALSO
26 /* set_eugid(3) switch effective rights
27 /* LICENSE
28 /* .ad
29 /* .fi
30 /* The Secure Mailer license must be distributed with this software.
31 /* AUTHOR(S)
32 /* Wietse Venema
33 /* IBM T.J. Watson Research
34 /* P.O. Box 704
35 /* Yorktown Heights, NY 10598, USA
36 /*--*/
37
38 /* System library. */
39
40 #include <sys_defs.h>
41 #include <sys/stat.h>
42 #include <unistd.h>
43
44 /* Utility library. */
45
46 #include "msg.h"
47 #include "set_eugid.h"
48 #include "lstat_as.h"
49 #include "warn_stat.h"
50
51 /* lstat_as - lstat file as user */
52
lstat_as(const char * path,struct stat * st,uid_t euid,gid_t egid)53 int lstat_as(const char *path, struct stat * st, uid_t euid, gid_t egid)
54 {
55 uid_t saved_euid = geteuid();
56 gid_t saved_egid = getegid();
57 int status;
58
59 /*
60 * Switch to the target user privileges.
61 */
62 set_eugid(euid, egid);
63
64 /*
65 * Lstat that file.
66 */
67 status = lstat(path, st);
68
69 /*
70 * Restore saved privileges.
71 */
72 set_eugid(saved_euid, saved_egid);
73
74 return (status);
75 }
76