1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
|
/* $OpenBSD: access.c,v 1.1 2014/04/27 22:18:25 guenther Exp $ */
/*
* Written by Philip Guenther <guenther@openbsd.org> 2014 Public Domain.
*/
#include <sys/stat.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#define UID_YES 991
#define UID_NO 990
#define GID_YES 991
#define GID_NO 990
char dir[] = "testdir";
char exists[] = "testdir/testfile";
char r_r_exists[] = "testdir/testfile_r_r";
char r_w_exists[] = "testdir/testfile_r_w";
char w_r_exists[] = "testdir/testfile_w_r";
char w_w_exists[] = "testdir/testfile_w_w";
char x_x_exists[] = "testdir/testfile_x_x";
char noexists[] = "testdir/nosuchfile";
char temp[] = "/tmp/accessXXXXXXXXX";
struct tests {
int err, eaccess;
uid_t ruid, euid;
gid_t rgid, egid;
int amode;
const char *filename;
} tests[] = {
/* RETURNS EACC RUID EUID RGID EGID AMODE FILENAME */
/* negative tests */
/* unable to search through the directory */
{ EACCES, 0, UID_NO, UID_NO, GID_NO, GID_NO, F_OK, exists },
{ EACCES, 0, UID_NO, UID_YES, GID_NO, GID_NO, F_OK, exists },
{ EACCES, 0, UID_NO, UID_NO, GID_NO, GID_YES, F_OK, exists },
{ EACCES, 0, UID_NO, UID_YES, GID_NO, GID_YES, F_OK, exists },
{ EACCES, 1, UID_NO, UID_NO, GID_NO, GID_NO, F_OK, exists },
{ EACCES, 1, UID_YES, UID_NO, GID_NO, GID_NO, F_OK, exists },
{ EACCES, 1, UID_NO, UID_NO, GID_YES, GID_NO, F_OK, exists },
{ EACCES, 1, UID_YES, UID_NO, GID_YES, GID_NO, F_OK, exists },
/* can search to it, but the file ain't there */
{ ENOENT, 0, UID_YES, UID_NO, GID_NO, GID_NO, F_OK, noexists },
{ ENOENT, 0, UID_NO, UID_NO, GID_YES, GID_NO, F_OK, noexists },
{ ENOENT, 0, UID_YES, UID_NO, GID_YES, GID_NO, F_OK, noexists },
{ ENOENT, 1, UID_NO, UID_YES, GID_NO, GID_NO, F_OK, noexists },
{ ENOENT, 1, UID_NO, UID_NO, GID_NO, GID_YES, F_OK, noexists },
{ ENOENT, 1, UID_NO, UID_YES, GID_NO, GID_YES, F_OK, noexists },
/* can search to it, but the file doesn't have read perm */
{ EACCES, 0, UID_YES, UID_NO, GID_NO, GID_NO, R_OK, w_w_exists },
{ EACCES, 0, UID_NO, UID_NO, GID_YES, GID_NO, R_OK, w_w_exists },
{ EACCES, 0, UID_YES, UID_NO, GID_YES, GID_NO, R_OK, w_w_exists },
{ EACCES, 1, UID_NO, UID_YES, GID_NO, GID_NO, R_OK, w_w_exists },
{ EACCES, 1, UID_NO, UID_NO, GID_NO, GID_YES, R_OK, w_w_exists },
/* can search to it, but the file doesn't have the right read perm */
{ EACCES, 0, UID_YES, UID_NO, GID_NO, GID_NO, R_OK, w_r_exists },
{ EACCES, 0, UID_NO, UID_NO, GID_YES, GID_NO, R_OK, r_w_exists },
{ EACCES, 1, UID_NO, UID_YES, GID_NO, GID_NO, R_OK, w_r_exists },
{ EACCES, 1, UID_NO, UID_NO, GID_NO, GID_YES, R_OK, r_w_exists },
/* if correct user, then group perms are ignored */
{ EACCES, 0, UID_YES, UID_NO, GID_YES, GID_NO, R_OK, w_r_exists },
{ EACCES, 1, UID_NO, UID_YES, GID_NO, GID_YES, R_OK, w_r_exists },
{ EACCES, 0, UID_YES, UID_YES, GID_YES, GID_YES, R_OK, w_r_exists },
{ EACCES, 1, UID_YES, UID_YES, GID_YES, GID_YES, R_OK, w_r_exists },
/* positive tests */
{ 0, 0, UID_YES, UID_NO, GID_NO, GID_NO, R_OK, r_w_exists },
{ 0, 0, UID_NO, UID_NO, GID_YES, GID_NO, R_OK, w_r_exists },
{ 0, 0, UID_YES, UID_NO, GID_YES, GID_NO, R_OK, r_w_exists },
{ 0, 0, UID_YES, UID_NO, GID_YES, GID_NO, R_OK, r_r_exists },
{ 0, 1, UID_NO, UID_YES, GID_NO, GID_NO, R_OK, r_w_exists },
{ 0, 1, UID_NO, UID_NO, GID_NO, GID_YES, R_OK, w_r_exists },
{ 0, 1, UID_NO, UID_YES, GID_NO, GID_YES, R_OK, r_w_exists },
{ 0, 1, UID_NO, UID_YES, GID_NO, GID_YES, R_OK, r_r_exists },
{ 0, 0, UID_YES, UID_YES, GID_YES, GID_YES, R_OK, r_w_exists },
{ 0, 0, UID_YES, UID_YES, GID_YES, GID_YES, R_OK, r_r_exists },
{ 0, 1, UID_YES, UID_YES, GID_YES, GID_YES, R_OK, r_w_exists },
{ 0, 1, UID_YES, UID_YES, GID_YES, GID_YES, R_OK, r_r_exists },
{ 0 }
};
static void
prepfile(const char *filename, mode_t mode)
{
int fd;
if ((fd = open(filename, O_WRONLY|O_CREAT, 600)) < 0)
err(1, "open %s", filename);
close(fd);
if (chown(filename, UID_YES, GID_YES))
err(1, "chown %s %d:%d", filename, UID_YES, GID_YES);
if (chmod(filename, mode))
err(1, "chmod %s %o", filename, mode);
}
static void
docleanup(void)
{
setresuid(0, 0, 0);
remove(exists);
remove(r_r_exists);
remove(r_w_exists);
remove(w_r_exists);
remove(w_w_exists);
remove(x_x_exists);
remove(dir);
chdir("/");
remove(temp);
}
int
main(int argc, char *argv[])
{
char buf[200];
struct tests *t;
int ret, result;
gid_t supp_group = GID_NO;
if (geteuid() != 0) {
if (getuid() != 0)
errx(0, "must be run as root");
else if (setuid(0))
err(1, "setuid");
}
if (setgroups(1, &supp_group))
err(1, "setgroups");
if (mkdtemp(temp) == NULL)
err(1, "mkdtemp");
if (chdir(temp)) {
ret = errno;
remove(temp);
errc(1, ret, "chdir");
}
if (chmod(temp, 0755))
err(1, "chmod %s %o", temp, 0755);
atexit(docleanup);
umask(0);
if (mkdir(dir, 0750))
err(1, "mkdir");
prepfile(exists, 0);
prepfile(r_r_exists, 0440);
prepfile(r_w_exists, 0420);
prepfile(w_r_exists, 0240);
prepfile(w_w_exists, 0220);
prepfile(x_x_exists, 0110);
if (chown(dir, UID_YES, GID_YES))
err(1, "chown %s %d:%d", dir, UID_YES, GID_YES);
result = 0;
for (t = tests; t->filename != NULL; t++) {
if (setresgid(t->rgid, t->egid, 0))
err(1, "setresgid");
if (setresuid(t->ruid, t->euid, 0))
err(1, "setresuid");
ret = faccessat(AT_FDCWD, t->filename, t->amode,
t->eaccess ? AT_EACCESS : 0);
if (ret) {
ret = errno;
strerror_r(ret, buf, sizeof buf);
}
if (ret != t->err) {
result = 1;
warnx("uid %d/%d gid %d/%d mode %d eaccess %d %s:"
" %s instead of %s",
t->ruid, t->euid, t->rgid, t->egid,
t->amode, t->eaccess, t->filename,
ret ? buf : "success",
t->err ? strerror(t->err) : "success");
}
if (setresuid(0, 0, 0))
err(1, "setresuid restore");
}
return (result);
}
|
