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
|
/*
* $OpenBSD: dup2test.c,v 1.3 2003/07/31 21:48:08 deraadt Exp $
* $OpenBSD: dup2_self.c,v 1.3 2003/07/31 21:48:08 deraadt Exp $
* $OpenBSD: fcntl_dup.c,v 1.2 2003/07/31 21:48:08 deraadt Exp $
*
* Written by Artur Grabowski <art@openbsd.org> 2002 Public Domain.
*
* $FreeBSD$
*/
/*
* Test #1: check if dup(2) works.
* Test #2: check if dup2(2) works.
* Test #3: check if dup2(2) returned a fd we asked for.
* Test #4: check if dup2(2) cleared close-on-exec flag for duped fd.
* Test #5: check if dup2(2) allows to dup fd to itself.
* Test #6: check if dup2(2) returned a fd we asked for.
* Test #7: check if dup2(2) did not clear close-on-exec flag for duped fd.
* Test #8: check if fcntl(F_DUPFD) works.
* Test #9: check if fcntl(F_DUPFD) cleared close-on-exec flag for duped fd.
* Test #10: check if dup2() to a fd > current maximum number of open files
* limit work.
*/
#include <sys/types.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <err.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
static int getafile(void);
static int
getafile(void)
{
int fd;
char temp[] = "/tmp/dup2XXXXXXXXX";
if ((fd = mkstemp(temp)) < 0)
err(1, "mkstemp");
remove(temp);
if (ftruncate(fd, 1024) != 0)
err(1, "ftruncate");
return (fd);
}
int
main(int __unused argc, char __unused *argv[])
{
struct rlimit rlp;
int orgfd, fd1, fd2, test = 0;
orgfd = getafile();
printf("1..10\n");
/* If dup(2) ever work? */
if ((fd1 = dup(orgfd)) < 0)
err(1, "dup");
printf("ok %d - dup(2) works\n", ++test);
/* Set close-on-exec */
if (fcntl(fd1, F_SETFD, 1) != 0)
err(1, "fcntl(F_SETFD)");
/* If dup2(2) ever work? */
if ((fd2 = dup2(fd1, fd1 + 1)) < 0)
err(1, "dup2");
printf("ok %d - dup2(2) works\n", ++test);
/* Do we get the right fd? */
++test;
if (fd2 != fd1 + 1)
printf("no ok %d - dup2(2) didn't give us the right fd\n",
test);
else
printf("ok %d - dup2(2) returned a correct fd\n", test);
/* Was close-on-exec cleared? */
++test;
if (fcntl(fd2, F_GETFD) != 0)
printf("not ok %d - dup2(2) didn't clear close-on-exec\n",
test);
else
printf("ok %d - dup2(2) cleared close-on-exec\n", test);
/*
* Dup to itself.
*
* We're testing a small tweak in dup2 semantics.
* Normally dup and dup2 will clear the close-on-exec
* flag on the new fd (which appears to be an implementation
* mistake from start and not some planned behavior).
* In todays implementations of dup and dup2 we have to make
* an effort to really clear that flag. But all tested
* implementations of dup2 have another tweak. If we
* dup2(old, new) when old == new, the syscall short-circuits
* and returns early (because there is no need to do all the
* work (and there is a risk for serious mistakes)).
* So although the docs say that dup2 should "take 'old',
* close 'new' perform a dup(2) of 'old' into 'new'"
* the docs are not really followed because close-on-exec
* is not cleared on 'new'.
*
* Since everyone has this bug, we pretend that this is
* the way it is supposed to be and test here that it really
* works that way.
*
* This is a fine example on where two separate implementation
* fuckups take out each other and make the end-result the way
* it was meant to be.
*/
if ((fd2 = dup2(fd1, fd1)) < 0)
err(1, "dup2");
printf("ok %d - dup2(2) to itself works\n", ++test);
/* Do we get the right fd? */
++test;
if (fd2 != fd1)
printf("not ok %d - dup2(2) didn't give us the right fd\n",
test);
else
printf("ok %d - dup2(2) to itself returned a correct fd\n",
test);
/* Was close-on-exec cleared? */
++test;
if (fcntl(fd2, F_GETFD) == 0)
printf("not ok %d - dup2(2) cleared close-on-exec\n", test);
else
printf("ok %d - dup2(2) didn't clear close-on-exec\n", test);
/* Does fcntl(F_DUPFD) work? */
if ((fd2 = fcntl(fd1, F_DUPFD)) < 0)
err(1, "fcntl(F_DUPFD)");
printf("ok %d - fcntl(F_DUPFD) works\n", ++test);
/* Was close-on-exec cleared? */
++test;
if (fcntl(fd2, F_GETFD) != 0)
printf(
"not ok %d - fcntl(F_DUPFD) didn't clear close-on-exec\n",
test);
else
printf("ok %d - fcntl(F_DUPFD) cleared close-on-exec\n", test);
++test;
if (getrlimit(RLIMIT_NOFILE, &rlp) < 0)
err(1, "getrlimit");
if ((fd2 = dup2(fd1, rlp.rlim_cur + 1)) == 0)
printf("not ok %d - dup2(2) bypassed NOFILE limit\n", test);
else
printf("ok %d - dup2(2) didn't bypass NOFILE limit\n", test);
return (0);
}
|
