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 
45 static const char	*getpath(void);
46 static char		 path[] = "link";
47 static const char	*pathl;
48 
49 static const char *
50 getpath(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 
65 ATF_TC_WITH_CLEANUP(link_count);
66 ATF_TC_HEAD(link_count, tc)
67 {
68 	atf_tc_set_md_var(tc, "descr", "link(2) counts are incremented?");
69 }
70 
71 ATF_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 
97 ATF_TC_CLEANUP(link_count, tc)
98 {
99 	(void)unlink(path);
100 	(void)unlink(pathl);
101 }
102 
103 ATF_TC_WITH_CLEANUP(link_err);
104 ATF_TC_HEAD(link_err, tc)
105 {
106 	atf_tc_set_md_var(tc, "descr", "Test error conditions of link(2)");
107 }
108 
109 ATF_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 
149 ATF_TC_CLEANUP(link_err, tc)
150 {
151 	(void)unlink(path);
152 	(void)unlink(pathl);
153 }
154 
155 ATF_TC(link_perm);
156 ATF_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 
162 ATF_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 
177 ATF_TC_WITH_CLEANUP(link_stat);
178 ATF_TC_HEAD(link_stat, tc)
179 {
180 	atf_tc_set_md_var(tc, "descr", "Check stat(2) of a linked file");
181 }
182 
183 ATF_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 
215 ATF_TC_CLEANUP(link_stat, tc)
216 {
217 	(void)unlink(path);
218 	(void)unlink(pathl);
219 }
220 
221 ATF_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