cde/programs/dtksh/ksh93/src/lib/libast/preroot/ispreroot.c

   1 /* $XConsortium: ispreroot.c /main/3 1995/11/01 18:21:21 rswiston $ */
   2 /***************************************************************
   3 *                                                              *
   4 *                      AT&T - PROPRIETARY                      *
   5 *                                                              *
   6 *         THIS IS PROPRIETARY SOURCE CODE LICENSED BY          *
   7 *                          AT&T CORP.                          *
   8 *                                                              *
   9 *                Copyright (c) 1995 AT&T Corp.                 *
  10 *                     All Rights Reserved                      *
  11 *                                                              *
  12 *           This software is licensed by AT&T Corp.            *
  13 *       under the terms and conditions of the license in       *
  14 *       http://www.research.att.com/orgs/ssr/book/reuse        *
  15 *                                                              *
  16 *               This software was created by the               *
  17 *           Software Engineering Research Department           *
  18 *                    AT&T Bell Laboratories                    *
  19 *                                                              *
  20 *               For further information contact                *
  21 *                     gsf@research.att.com                     *
  22 *                                                              *
  23 ***************************************************************/
  24
  25 /* : : generated by proto : : */
  26
  27 #if !defined(__PROTO__)
  28 #if defined(__STDC__) || defined(__cplusplus) || defined(_proto) || defined(c_plusplus)
  29 #if defined(__cplusplus)
  30 #define __MANGLE__      "C"
  31 #else
  32 #define __MANGLE__
  33 #endif
  34 #define __STDARG__
  35 #define __PROTO__(x)    x
  36 #define __OTORP__(x)
  37 #define __PARAM__(n,o)  n
  38 #if !defined(__STDC__) && !defined(__cplusplus)
  39 #if !defined(c_plusplus)
  40 #define const
  41 #endif
  42 #define signed
  43 #define void            int
  44 #define volatile
  45 #define __V_            char
  46 #else
  47 #define __V_            void
  48 #endif
  49 #else
  50 #define __PROTO__(x)    ()
  51 #define __OTORP__(x)    x
  52 #define __PARAM__(n,o)  o
  53 #define __MANGLE__
  54 #define __V_            char
  55 #define const
  56 #define signed
  57 #define void            int
  58 #define volatile
  59 #endif
  60 #if defined(__cplusplus) || defined(c_plusplus)
  61 #define __VARARG__      ...
  62 #else
  63 #define __VARARG__
  64 #endif
  65 #if defined(__STDARG__)
  66 #define __VA_START__(p,a)       va_start(p,a)
  67 #else
  68 #define __VA_START__(p,a)       va_start(p)
  69 #endif
  70 #endif
  71 #include <ast.h>
  72 #include <preroot.h>
  73
  74 #if FS_PREROOT
  75
  76 #include <ls.h>
  77
  78 /*
  79  * return 1 if files a and b are the same under preroot
  80  *
  81  * NOTE: the kernel disables preroot for set-uid processes
  82  */
  83
  84 static int
  85 same __PARAM__((const char* a, const char* b), (a, b)) __OTORP__(const char* a; const char* b;){
  86         int             i;
  87         int             euid;
  88         int             ruid;
  89
  90         struct stat     ast;
  91         struct stat     bst;
  92
  93         if ((ruid = getuid()) != (euid = geteuid())) setuid(ruid);
  94         i = !stat(a, &ast) && !stat(b, &bst) && ast.st_dev == bst.st_dev && ast.st_ino == bst.st_ino;
  95         if (ruid != euid) setuid(euid);
  96         return(i);
  97 }
  98
  99 int
 100 ispreroot __PARAM__((const char* dir), (dir)) __OTORP__(const char* dir;){
 101         static int      prerooted = -1;
 102
 103         if (dir) return(same("/", dir));
 104         if (prerooted < 0) prerooted = !same("/", PR_REAL);
 105         return(prerooted);
 106 }
 107
 108 #else
 109
 110 NoN(ispreroot)
 111
 112 #endif