t_link.c revision 314817 
1/* $NetBSD: t_link.c,v 1.3 2017/01/13 20:42:36 christos Exp $ */
2
3/*-
4 * Copyright (c) 2011 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Jukka Ruohonen.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31#include <sys/cdefs.h>
32__RCSID("$NetBSD: t_link.c,v 1.3 2017/01/13 20:42:36 christos Exp $");
33
34#include <sys/param.h>
35#include <sys/stat.h>
36
37#include <atf-c.h>
38#include <errno.h>
39#include <fcntl.h>
40#include <limits.h>
41#include <stdio.h>
42#include <string.h>
43#include <unistd.h>
44
45static const char	*getpath(void);
46static char		 path[] = "link";
47static const char	*pathl;
48
49static const char *
50getpath(void)
51{
52	static char buf[LINE_MAX];
53
54	(void)memset(buf, '\0', sizeof(buf));
55
56	if (getcwd(buf, sizeof(buf)) == NULL)
57		return NULL;
58
59	(void)strlcat(buf, path, sizeof(buf));
60	(void)strlcat(buf, ".link", sizeof(buf));
61
62	return buf;
63}
64
65ATF_TC_WITH_CLEANUP(link_count);
66ATF_TC_HEAD(link_count, tc)
67{
68	atf_tc_set_md_var(tc, "descr", "link(2) counts are incremented?");
69}
70
71ATF_TC_BODY(link_count, tc)
72{
73	struct stat sa, sb;
74	int fd;
75
76	(void)memset(&sa, 0, sizeof(struct stat));
77	(void)memset(&sb, 0, sizeof(struct stat));
78
79	pathl = getpath();
80	fd = open(path, O_RDWR | O_CREAT, 0600);
81
82	ATF_REQUIRE(fd >= 0);
83	ATF_REQUIRE(pathl != NULL);
84
85	ATF_REQUIRE(stat(path, &sa) == 0);
86	ATF_REQUIRE(link(path, pathl) == 0);
87	ATF_REQUIRE(stat(path, &sb) == 0);
88
89	if (sa.st_nlink != sb.st_nlink - 1)
90		atf_tc_fail("incorrect link(2) count");
91
92	ATF_REQUIRE(close(fd) == 0);
93	ATF_REQUIRE(unlink(path) == 0);
94	ATF_REQUIRE(unlink(pathl) == 0);
95}
96
97ATF_TC_CLEANUP(link_count, tc)
98{
99	(void)unlink(path);
100	(void)unlink(pathl);
101}
102
103ATF_TC_WITH_CLEANUP(link_err);
104ATF_TC_HEAD(link_err, tc)
105{
106	atf_tc_set_md_var(tc, "descr", "Test error conditions of link(2)");
107}
108
109ATF_TC_BODY(link_err, tc)
110{
111	char buf[MAXPATHLEN + 1];
112	int fd;
113
114	(void)memset(buf, 'x', sizeof(buf));
115
116	pathl = getpath();
117	fd = open(path, O_RDWR | O_CREAT, 0600);
118
119	ATF_REQUIRE(fd >= 0);
120	ATF_REQUIRE(pathl != NULL);
121
122	errno = 0;
123	ATF_REQUIRE(link(path, pathl) == 0);
124	ATF_REQUIRE_ERRNO(EEXIST, link(path, pathl) == -1);
125
126	errno = 0;
127	ATF_REQUIRE_ERRNO(ENAMETOOLONG, link(buf, "xxx") == -1);
128
129	errno = 0;
130	ATF_REQUIRE_ERRNO(ENOENT, link(path, "/d/c/b/a") == -1);
131
132	errno = 0;
133	ATF_REQUIRE_ERRNO(ENOENT, link("/a/b/c/d", path) == -1);
134
135	errno = 0;
136	ATF_REQUIRE_ERRNO(ENOENT, link("/a/b/c/d", "/d/c/b/a") == -1);
137
138	errno = 0;
139	ATF_REQUIRE_ERRNO(EFAULT, link(path, (const char *)-1) == -1);
140
141	errno = 0;
142	ATF_REQUIRE_ERRNO(EFAULT, link((const char *)-1, "xxx") == -1);
143
144	ATF_REQUIRE(close(fd) == 0);
145	ATF_REQUIRE(unlink(path) == 0);
146	ATF_REQUIRE(unlink(pathl) == 0);
147}
148
149ATF_TC_CLEANUP(link_err, tc)
150{
151	(void)unlink(path);
152	(void)unlink(pathl);
153}
154
155ATF_TC(link_perm);
156ATF_TC_HEAD(link_perm, tc)
157{
158	atf_tc_set_md_var(tc, "descr", "Test permissions with link(2)");
159	atf_tc_set_md_var(tc, "require.user", "unprivileged");
160}
161
162ATF_TC_BODY(link_perm, tc)
163{
164	int rv;
165
166	errno = 0;
167	rv = link("/root", "/root.link");
168	ATF_REQUIRE_MSG(rv == -1 && (errno == EACCES || errno == EPERM),
169	    "link to a directory did not fail with EPERM or EACCESS; link() "
170	    "returned %d, errno %d", rv, errno);
171
172	errno = 0;
173	ATF_REQUIRE_ERRNO(EACCES,
174	    link("/root/.profile", "/root/.profile.link") == -1);
175}
176
177ATF_TC_WITH_CLEANUP(link_stat);
178ATF_TC_HEAD(link_stat, tc)
179{
180	atf_tc_set_md_var(tc, "descr", "Check stat(2) of a linked file");
181}
182
183ATF_TC_BODY(link_stat, tc)
184{
185	struct stat sa, sb;
186	int fd;
187
188	(void)memset(&sa, 0, sizeof(struct stat));
189	(void)memset(&sb, 0, sizeof(struct stat));
190
191	pathl = getpath();
192	fd = open(path, O_RDWR | O_CREAT, 0600);
193
194	ATF_REQUIRE(fd >= 0);
195	ATF_REQUIRE(pathl != NULL);
196
197	ATF_REQUIRE(link(path, pathl) == 0);
198	ATF_REQUIRE(stat(path, &sa) == 0);
199	ATF_REQUIRE(lstat(pathl, &sb) == 0);
200
201	if (sa.st_uid != sb.st_uid)
202		atf_tc_fail("unequal UIDs");
203
204	if (sa.st_mode != sb.st_mode)
205		atf_tc_fail("unequal modes");
206
207	if (sa.st_ino != sb.st_ino)
208		atf_tc_fail("unequal inodes");
209
210	ATF_REQUIRE(close(fd) == 0);
211	ATF_REQUIRE(unlink(path) == 0);
212	ATF_REQUIRE(unlink(pathl) == 0);
213}
214
215ATF_TC_CLEANUP(link_stat, tc)
216{
217	(void)unlink(path);
218	(void)unlink(pathl);
219}
220
221ATF_TP_ADD_TCS(tp)
222{
223
224	ATF_TP_ADD_TC(tp, link_count);
225	ATF_TP_ADD_TC(tp, link_err);
226	ATF_TP_ADD_TC(tp, link_perm);
227	ATF_TP_ADD_TC(tp, link_stat);
228
229	return atf_no_error();
230}
231