xref: /freebsd/tests/sys/fs/fusefs/readlink.cc (revision aa1a8ff2d6dbc51ef058f46f3db5a8bb77967145)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2019 The FreeBSD Foundation
5  *
6  * This software was developed by BFF Storage Systems, LLC under sponsorship
7  * from the FreeBSD Foundation.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 extern "C" {
32 #include <sys/param.h>
33 
34 #include <unistd.h>
35 }
36 
37 #include "mockfs.hh"
38 #include "utils.hh"
39 
40 using namespace testing;
41 
42 class Readlink: public FuseTest {
43 public:
44 void expect_lookup(const char *relpath, uint64_t ino)
45 {
46 	FuseTest::expect_lookup(relpath, ino, S_IFLNK | 0777, 0, 1);
47 }
48 void expect_readlink(uint64_t ino, ProcessMockerT r)
49 {
50 	EXPECT_CALL(*m_mock, process(
51 		ResultOf([=](auto in) {
52 			return (in.header.opcode == FUSE_READLINK &&
53 				in.header.nodeid == ino);
54 		}, Eq(true)),
55 		_)
56 	).WillOnce(Invoke(r));
57 }
58 
59 };
60 
61 class PushSymlinksIn: public Readlink {
62 	virtual void SetUp() {
63 		m_push_symlinks_in = true;
64 		Readlink::SetUp();
65 	}
66 };
67 
68 TEST_F(Readlink, eloop)
69 {
70 	const char FULLPATH[] = "mountpoint/src";
71 	const char RELPATH[] = "src";
72 	const uint64_t ino = 42;
73 	char buf[80];
74 
75 	expect_lookup(RELPATH, ino);
76 	expect_readlink(ino, ReturnErrno(ELOOP));
77 
78 	EXPECT_EQ(-1, readlink(FULLPATH, buf, sizeof(buf)));
79 	EXPECT_EQ(ELOOP, errno);
80 }
81 
82 /*
83  * If a malicious or buggy server returns a NUL in the FUSE_READLINK result, it
84  * should be handled gracefully.
85  * https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=274268
86  */
87 TEST_F(Readlink, embedded_nul)
88 {
89 	const char FULLPATH[] = "mountpoint/src";
90 	const char RELPATH[] = "src";
91 	const char dst[] = "dst\0stuff";
92 	char buf[80];
93 	const uint64_t ino = 42;
94 
95 	EXPECT_LOOKUP(FUSE_ROOT_ID, RELPATH)
96 	.WillOnce(Invoke(ReturnImmediate([=](auto in __unused, auto& out) {
97 		SET_OUT_HEADER_LEN(out, entry);
98 		out.body.entry.attr.mode = S_IFLNK | 0777;
99 		out.body.entry.nodeid = ino;
100 		out.body.entry.attr_valid = UINT64_MAX;
101 		out.body.entry.entry_valid = UINT64_MAX;
102 	})));
103 
104 	EXPECT_CALL(*m_mock, process(
105 		ResultOf([=](auto in) {
106 			return (in.header.opcode == FUSE_READLINK &&
107 				in.header.nodeid == ino);
108 		}, Eq(true)),
109 		_)
110 	).WillRepeatedly(Invoke(ReturnImmediate([=](auto in __unused, auto& out) {
111 		memcpy(out.body.str, dst, sizeof(dst));
112 		out.header.len = sizeof(out.header) + sizeof(dst) + 1;
113 	})));
114 
115 	EXPECT_EQ(-1, readlink(FULLPATH, buf, sizeof(buf)));
116 	EXPECT_EQ(EIO, errno);
117 	EXPECT_EQ(-1, access(FULLPATH, R_OK));
118 	EXPECT_EQ(EIO, errno);
119 }
120 
121 TEST_F(Readlink, ok)
122 {
123 	const char FULLPATH[] = "mountpoint/src";
124 	const char RELPATH[] = "src";
125 	const char dst[] = "dst";
126 	const uint64_t ino = 42;
127 	char buf[80];
128 
129 	expect_lookup(RELPATH, ino);
130 	expect_readlink(ino, ReturnImmediate([=](auto in __unused, auto& out) {
131 		strlcpy(out.body.str, dst, sizeof(out.body.str));
132 		out.header.len = sizeof(out.header) + strlen(dst) + 1;
133 	}));
134 
135 	EXPECT_EQ(static_cast<ssize_t>(strlen(dst)) + 1,
136 		  readlink(FULLPATH, buf, sizeof(buf)));
137 	EXPECT_STREQ(dst, buf);
138 }
139 
140 TEST_F(PushSymlinksIn, readlink)
141 {
142 	const char FULLPATH[] = "mountpoint/src";
143 	const char RELPATH[] = "src";
144 	const char dst[] = "/dst";
145 	const uint64_t ino = 42;
146 	char buf[MAXPATHLEN], wd[MAXPATHLEN], want[MAXPATHLEN];
147 	int len;
148 
149 	expect_lookup(RELPATH, ino);
150 	expect_readlink(ino, ReturnImmediate([=](auto in __unused, auto& out) {
151 		strlcpy(out.body.str, dst, sizeof(out.body.str));
152 		out.header.len = sizeof(out.header) + strlen(dst) + 1;
153 	}));
154 
155 	ASSERT_NE(nullptr, getcwd(wd, sizeof(wd))) << strerror(errno);
156 	len = snprintf(want, sizeof(want), "%s/mountpoint%s", wd, dst);
157 	ASSERT_LE(0, len) << strerror(errno);
158 
159 	EXPECT_EQ(static_cast<ssize_t>(len) + 1,
160 		readlink(FULLPATH, buf, sizeof(buf)));
161 	EXPECT_STREQ(want, buf);
162 }
163