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      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 
     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