2 * $OpenBSD: dup2test.c,v 1.3 2003/07/31 21:48:08 deraadt Exp $
3 * $OpenBSD: dup2_self.c,v 1.3 2003/07/31 21:48:08 deraadt Exp $
4 * $OpenBSD: fcntl_dup.c,v 1.2 2003/07/31 21:48:08 deraadt Exp $
6 * Written by Artur Grabowski <art@openbsd.org> 2002 Public Domain.
12 * Test #1: check if dup(2) works.
13 * Test #2: check if dup2(2) works.
14 * Test #3: check if dup2(2) returned a fd we asked for.
15 * Test #4: check if dup2(2) cleared close-on-exec flag for duped fd.
16 * Test #5: check if dup2(2) allows to dup fd to itself.
17 * Test #6: check if dup2(2) returned a fd we asked for.
18 * Test #7: check if dup2(2) did not clear close-on-exec flag for duped fd.
19 * Test #8: check if fcntl(F_DUPFD) works.
20 * Test #9: check if fcntl(F_DUPFD) cleared close-on-exec flag for duped fd.
21 * Test #10: check if dup2() to a fd > current maximum number of open files
25 #include <sys/types.h>
27 #include <sys/resource.h>
35 static int getafile(void);
42 char temp[] = "/tmp/dup2XXXXXXXXX";
43 if ((fd = mkstemp(temp)) < 0)
46 if (ftruncate(fd, 1024) != 0)
52 main(int __unused argc, char __unused *argv[])
55 int orgfd, fd1, fd2, test = 0;
61 /* If dup(2) ever work? */
62 if ((fd1 = dup(orgfd)) < 0)
64 printf("ok %d - dup(2) works\n", ++test);
66 /* Set close-on-exec */
67 if (fcntl(fd1, F_SETFD, 1) != 0)
68 err(1, "fcntl(F_SETFD)");
70 /* If dup2(2) ever work? */
71 if ((fd2 = dup2(fd1, fd1 + 1)) < 0)
73 printf("ok %d - dup2(2) works\n", ++test);
75 /* Do we get the right fd? */
78 printf("no ok %d - dup2(2) didn't give us the right fd\n",
81 printf("ok %d - dup2(2) returned a correct fd\n", test);
83 /* Was close-on-exec cleared? */
85 if (fcntl(fd2, F_GETFD) != 0)
86 printf("not ok %d - dup2(2) didn't clear close-on-exec\n",
89 printf("ok %d - dup2(2) cleared close-on-exec\n", test);
94 * We're testing a small tweak in dup2 semantics.
95 * Normally dup and dup2 will clear the close-on-exec
96 * flag on the new fd (which appears to be an implementation
97 * mistake from start and not some planned behavior).
98 * In todays implementations of dup and dup2 we have to make
99 * an effort to really clear that flag. But all tested
100 * implementations of dup2 have another tweak. If we
101 * dup2(old, new) when old == new, the syscall short-circuits
102 * and returns early (because there is no need to do all the
103 * work (and there is a risk for serious mistakes)).
104 * So although the docs say that dup2 should "take 'old',
105 * close 'new' perform a dup(2) of 'old' into 'new'"
106 * the docs are not really followed because close-on-exec
107 * is not cleared on 'new'.
109 * Since everyone has this bug, we pretend that this is
110 * the way it is supposed to be and test here that it really
113 * This is a fine example on where two separate implementation
114 * fuckups take out each other and make the end-result the way
115 * it was meant to be.
117 if ((fd2 = dup2(fd1, fd1)) < 0)
119 printf("ok %d - dup2(2) to itself works\n", ++test);
121 /* Do we get the right fd? */
124 printf("not ok %d - dup2(2) didn't give us the right fd\n",
127 printf("ok %d - dup2(2) to itself returned a correct fd\n",
130 /* Was close-on-exec cleared? */
132 if (fcntl(fd2, F_GETFD) == 0)
133 printf("not ok %d - dup2(2) cleared close-on-exec\n", test);
135 printf("ok %d - dup2(2) didn't clear close-on-exec\n", test);
137 /* Does fcntl(F_DUPFD) work? */
138 if ((fd2 = fcntl(fd1, F_DUPFD)) < 0)
139 err(1, "fcntl(F_DUPFD)");
140 printf("ok %d - fcntl(F_DUPFD) works\n", ++test);
142 /* Was close-on-exec cleared? */
144 if (fcntl(fd2, F_GETFD) != 0)
146 "not ok %d - fcntl(F_DUPFD) didn't clear close-on-exec\n",
149 printf("ok %d - fcntl(F_DUPFD) cleared close-on-exec\n", test);
152 if (getrlimit(RLIMIT_NOFILE, &rlp) < 0)
154 if ((fd2 = dup2(fd1, rlp.rlim_cur + 1)) == 0)
155 printf("not ok %d - dup2(2) bypassed NOFILE limit\n", test);
157 printf("ok %d - dup2(2) didn't bypass NOFILE limit\n", test);