1 /*
2 * Copyright (c) 2001 Proofpoint, Inc. and its suppliers.
3 * All rights reserved.
4 *
5 * By using this file, you agree to the terms and conditions set
6 * forth in the LICENSE file which can be found at the top level of
7 * the sendmail distribution.
8 *
9 */
10
11 /*
12 ** This program checks to see if your version of setreuid works.
13 ** Compile it, make it set-user-ID root, and run it as yourself (NOT as
14 ** root). If it won't compile or outputs any MAYDAY messages, don't
15 ** define HASSETREUID in conf.h.
16 **
17 ** Compilation is trivial -- just "cc t_setreuid.c". Make it set-user-ID,
18 ** root and then execute it as a non-root user.
19 */
20
21 #include <sys/types.h>
22 #include <unistd.h>
23 #include <stdio.h>
24
25 #ifndef lint
26 static char id[] = "@(#)$Id: t_setreuid.c,v 8.10 2013-11-22 20:52:01 ca Exp $";
27 #endif /* ! lint */
28
29 #ifdef __hpux
30 # define setreuid(r, e) setresuid(r, e, -1)
31 #endif /* __hpux */
32
33 static void
printuids(str,r,e)34 printuids(str, r, e)
35 char *str;
36 uid_t r, e;
37 {
38 printf("%s (should be %d/%d): r/euid=%d/%d\n", str, (int) r, (int) e,
39 (int) getuid(), (int) geteuid());
40 }
41
42 int
main(argc,argv)43 main(argc, argv)
44 int argc;
45 char **argv;
46 {
47 int fail = 0;
48 uid_t realuid = getuid();
49
50 printuids("initial uids", realuid, 0);
51
52 if (geteuid() != 0)
53 {
54 printf("SETUP ERROR: re-run set-user-ID root\n");
55 exit(1);
56 }
57
58 if (getuid() == 0)
59 {
60 printf("SETUP ERROR: must be run by a non-root user\n");
61 exit(1);
62 }
63
64 if (setreuid(0, 1) < 0)
65 {
66 fail++;
67 printf("setreuid(0, 1) failure\n");
68 }
69 printuids("after setreuid(0, 1)", 0, 1);
70
71 if (getuid() != 0)
72 {
73 fail++;
74 printf("MAYDAY! Wrong real uid\n");
75 }
76
77 if (geteuid() != 1)
78 {
79 fail++;
80 printf("MAYDAY! Wrong effective uid\n");
81 }
82
83 /* do activity here */
84
85 if (setreuid(-1, 0) < 0)
86 {
87 fail++;
88 printf("setreuid(-1, 0) failure\n");
89 }
90 printuids("after setreuid(-1, 0)", 0, 0);
91 if (setreuid(realuid, 0) < 0)
92 {
93 fail++;
94 printf("setreuid(%d, 0) failure\n", (int) realuid);
95 }
96 printuids("after setreuid(realuid, 0)", realuid, 0);
97
98 if (geteuid() != 0)
99 {
100 fail++;
101 printf("MAYDAY! Wrong effective uid\n");
102 }
103 if (getuid() != realuid)
104 {
105 fail++;
106 printf("MAYDAY! Wrong real uid\n");
107 }
108 printf("\n");
109
110 if (setreuid(0, 2) < 0)
111 {
112 fail++;
113 printf("setreuid(0, 2) failure\n");
114 }
115 printuids("after setreuid(0, 2)", 0, 2);
116
117 if (geteuid() != 2)
118 {
119 fail++;
120 printf("MAYDAY! Wrong effective uid\n");
121 }
122
123 if (getuid() != 0)
124 {
125 fail++;
126 printf("MAYDAY! Wrong real uid\n");
127 }
128
129 /* do activity here */
130
131 if (setreuid(-1, 0) < 0)
132 {
133 fail++;
134 printf("setreuid(-1, 0) failure\n");
135 }
136 printuids("after setreuid(-1, 0)", 0, 0);
137 if (setreuid(realuid, 0) < 0)
138 {
139 fail++;
140 printf("setreuid(%d, 0) failure\n", (int) realuid);
141 }
142 printuids("after setreuid(realuid, 0)", realuid, 0);
143
144 if (geteuid() != 0)
145 {
146 fail++;
147 printf("MAYDAY! Wrong effective uid\n");
148 }
149 if (getuid() != realuid)
150 {
151 fail++;
152 printf("MAYDAY! Wrong real uid\n");
153 }
154
155 if (fail)
156 {
157 printf("\nThis system cannot use setreuid\n");
158 exit(1);
159 }
160
161 printf("\nIt is safe to define HASSETREUID on this system\n");
162 exit(0);
163 }
164