ftruncate_test.c revision 312323 
1/*-
2 * Copyright (c) 2006 Robert N. M. Watson
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: stable/10/tests/sys/file/ftruncate_test.c 312323 2017-01-17 01:56:49Z ngie $
27 */
28
29/*
30 * Very simple regression test.
31 *
32 * Future tests that might be of interest:
33 *
34 * - Make sure we get EISDIR on a directory.
35 */
36
37#include <sys/types.h>
38#include <sys/event.h>
39#include <sys/socket.h>
40#include <sys/stat.h>
41
42#include <err.h>
43#include <errno.h>
44#include <fcntl.h>
45#include <inttypes.h>
46#include <limits.h>
47#include <stdio.h>
48#include <unistd.h>
49
50/*
51 * Select various potentially interesting lengths at and around power of 2
52 * edges.
53 */
54static off_t lengths[] = {0, 1, 2, 3, 4, 127, 128, 129, 511, 512, 513, 1023,
55    1024, 1025, 2047, 2048, 2049, 4095, 4096, 4097, 8191, 8192, 8193, 16383,
56    16384, 16385};
57static int lengths_count = sizeof(lengths) / sizeof(off_t);
58
59int
60main(void)
61{
62	int error, fd, fds[2], i, read_only_fd;
63	char path[PATH_MAX];
64	struct stat sb;
65	ssize_t size;
66	off_t len;
67	char ch;
68
69	/*
70	 * Tests using a writable temporary file: grow and then shrink a file
71	 * using ftruncate and various lengths.  Make sure that a negative
72	 * file length is rejected.  Make sure that when we grow the file,
73	 * bytes now in the range of the file size return 0.
74	 *
75	 * Save a read-only reference to the file to use later for read-only
76	 * descriptor tests.
77	 */
78	snprintf(path, PATH_MAX, "/tmp/ftruncate.XXXXXXXXXXXXX");
79	fd = mkstemp(path);
80	if (fd < 0)
81		err(-1, "mkstemp");
82	read_only_fd = open(path, O_RDONLY);
83	if (read_only_fd < 0) {
84		error = errno;
85		(void)unlink(path);
86		errno = error;
87		err(-1, "open(%s, O_RDONLY)", path);
88	}
89	(void)unlink(path);
90
91	if (ftruncate(fd, -1) == 0)
92		errx(-1, "ftruncate(fd, -1) succeeded");
93	if (errno != EINVAL)
94		err(-1, "ftruncate(fd, -1) returned wrong error");
95
96	for (i = 0; i < lengths_count; i++) {
97		len = lengths[i];
98		if (ftruncate(fd, len) < 0)
99			err(-1, "ftruncate(%jd) up", (intmax_t)len);
100		if (fstat(fd, &sb) < 0)
101			err(-1, "stat");
102		if (sb.st_size != len)
103			errx(-1, "fstat with len=%jd returned len %jd up",
104			    (intmax_t)len, (intmax_t)sb.st_size);
105		if (len != 0) {
106			size = pread(fd, &ch, sizeof(ch), len - 1);
107			if (size < 0)
108				err(-1, "pread on len %jd up", (intmax_t)len);
109			if (size != sizeof(ch))
110				errx(-1, "pread len %jd size %jd up",
111				    (intmax_t)len, (intmax_t)size);
112			if (ch != 0)
113				errx(-1,
114				    "pread length %jd size %jd ch %d up",
115				    (intmax_t)len, (intmax_t)size, ch);
116		}
117	}
118
119	for (i = lengths_count - 1; i >= 0; i--) {
120		len = lengths[i];
121		if (ftruncate(fd, len) < 0)
122			err(-1, "ftruncate(%jd) down", (intmax_t)len);
123		if (fstat(fd, &sb) < 0)
124			err(-1, "stat");
125		if (sb.st_size != len)
126			errx(-1, "fstat(%jd) returned %jd down", (intmax_t)len,
127			    sb.st_size);
128	}
129	close(fd);
130
131	/*
132	 * Make sure that a read-only descriptor can't be truncated.
133	 */
134	if (ftruncate(read_only_fd, 0) == 0)
135		errx(-1, "ftruncate(read_only_fd) succeeded");
136	if (errno != EINVAL)
137		err(-1, "ftruncate(read_only_fd) returned wrong error");
138	close(read_only_fd);
139
140	/*
141	 * Make sure that ftruncate on sockets doesn't work.
142	 */
143	fd = socket(PF_UNIX, SOCK_STREAM, 0);
144	if (fd < 0)
145		err(-1, "socket(PF_UNIX, SOCK_STREAM, 0)");
146	if (ftruncate(fd, 0) == 0)
147		errx(-1, "ftruncate(socket) succeeded");
148	if (errno != EINVAL)
149		err(-1, "ftruncate(socket) returned wrong error");
150	close(fd);
151
152	/*
153	 * Make sure that ftruncate on pipes doesn't work.
154	 */
155	if (pipe(fds) < 0)
156		err(-1, "pipe");
157	if (ftruncate(fds[0], 0) == 0)
158		errx(-1, "ftruncate(pipe) succeeded");
159	if (errno != EINVAL)
160		err(-1, "ftruncate(pipe) returned wrong error");
161	close(fds[0]);
162	close(fds[1]);
163
164	/*
165	 * Make sure that ftruncate on kqueues doesn't work.
166	 */
167	fd = kqueue();
168	if (fd < 0)
169		err(-1, "kqueue");
170	if (ftruncate(fds[0], 0) == 0)
171		errx(-1, "ftruncate(kqueue) succeeded");
172	if (errno != EINVAL)
173		err(-1, "ftruncate(kqueue) returned wrong error");
174	close(fd);
175
176	return (0);
177}
178