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1 /*
2  * Check decoding of SO_LINGER socket option.
3  *
4  * Copyright (c) 2017-2018 Dmitry V. Levin <ldv@altlinux.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. The name of the author may not be used to endorse or promote products
16  *    derived from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #include "tests.h"
31 
32 #include <stddef.h>
33 #include <stdio.h>
34 #include <string.h>
35 #include <sys/socket.h>
36 #include <unistd.h>
37 
38 static const char *errstr;
39 
40 static int
get_linger(int fd,void * val,socklen_t * len)41 get_linger(int fd, void *val, socklen_t *len)
42 {
43 	int rc = getsockopt(fd, SOL_SOCKET, SO_LINGER, val, len);
44 	errstr = sprintrc(rc);
45 	return rc;
46 }
47 
48 static int
set_linger(int fd,void * val,socklen_t len)49 set_linger(int fd, void *val, socklen_t len)
50 {
51 	int rc = setsockopt(fd, SOL_SOCKET, SO_LINGER, val, len);
52 	errstr = sprintrc(rc);
53 	return rc;
54 }
55 
56 int
main(void)57 main(void)
58 {
59 	TAIL_ALLOC_OBJECT_CONST_PTR(struct linger, linger);
60 	TAIL_ALLOC_OBJECT_CONST_PTR(socklen_t, len);
61 
62 	const unsigned int sizeof_l_onoff = sizeof(linger->l_onoff);
63 	struct linger *const l_onoff = tail_alloc(sizeof_l_onoff);
64 
65 	const unsigned int sizeof_l_onoff_truncated = sizeof_l_onoff - 1;
66 	struct linger *const l_onoff_truncated =
67 		tail_alloc(sizeof_l_onoff_truncated);
68 
69 	const unsigned int sizeof_l_linger_truncated =
70 		offsetofend(struct linger, l_linger) - 1;
71 	struct linger *const l_linger_truncated =
72 		tail_alloc(sizeof_l_linger_truncated);
73 
74         int fd = socket(AF_UNIX, SOCK_STREAM, 0);
75         if (fd < 0)
76                 perror_msg_and_skip("socket AF_UNIX SOCK_STREAM");
77 
78 	/* classic getsockopt */
79 	*len = sizeof(*linger);
80 	get_linger(fd, linger, len);
81 	printf("getsockopt(%d, SOL_SOCKET, SO_LINGER, {l_onoff=%d, l_linger=%d}"
82 	       ", [%d]) = %s\n",
83 	       fd, linger->l_onoff, linger->l_linger, *len, errstr);
84 
85 	/* classic setsockopt */
86 	linger->l_onoff = -15;
87 	linger->l_linger = -42;
88 	set_linger(fd, linger, sizeof(*linger));
89 	printf("setsockopt(%d, SOL_SOCKET, SO_LINGER, {l_onoff=%d, l_linger=%d}"
90 	       ", %d) = %s\n",
91 	       fd, linger->l_onoff, linger->l_linger,
92 	       (unsigned int) sizeof(*linger), errstr);
93 
94 	/* setsockopt with optlen larger than necessary */
95 	set_linger(fd, linger, sizeof(*linger) + 1);
96 	printf("setsockopt(%d, SOL_SOCKET, SO_LINGER, {l_onoff=%d, l_linger=%d}"
97 	       ", %d) = %s\n",
98 	       fd, linger->l_onoff, linger->l_linger,
99 	       (unsigned int) sizeof(*linger) + 1, errstr);
100 
101 	/* setsockopt with optlen < 0 - EINVAL */
102 	set_linger(fd, linger, -1U);
103 	printf("setsockopt(%d, SOL_SOCKET, SO_LINGER, %p, -1) = %s\n",
104 	       fd, linger, errstr);
105 
106 	/* setsockopt with optlen smaller than necessary - EINVAL */
107 	set_linger(fd, linger, sizeof(linger->l_onoff));
108 	printf("setsockopt(%d, SOL_SOCKET, SO_LINGER, %p, %d) = %s\n",
109 	       fd, linger, (unsigned int) sizeof(linger->l_onoff), errstr);
110 
111 	/* setsockopt optval EFAULT */
112 	set_linger(fd, &linger->l_linger, sizeof(*linger));
113 	printf("setsockopt(%d, SOL_SOCKET, SO_LINGER, %p, %d) = %s\n",
114 	       fd, &linger->l_linger, (unsigned int) sizeof(*linger), errstr);
115 
116 	/* getsockopt with zero optlen */
117 	*len = 0;
118 	get_linger(fd, linger, len);
119 	printf("getsockopt(%d, SOL_SOCKET, SO_LINGER, %p, [0]) = %s\n",
120 	       fd, linger, errstr);
121 
122 	/* getsockopt with optlen larger than necessary - shortened */
123 	*len = sizeof(*linger) + 1;
124 	get_linger(fd, linger, len);
125 	printf("getsockopt(%d, SOL_SOCKET, SO_LINGER, {l_onoff=%d, l_linger=%d}"
126 	       ", [%u->%d]) = %s\n",
127 	       fd, linger->l_onoff, linger->l_linger,
128 	       (unsigned int) sizeof(*linger) + 1, *len, errstr);
129 
130 	/*
131 	 * getsockopt with optlen less than sizeof(linger->l_onoff):
132 	 * the part of struct linger.l_onoff is printed in hex.
133 	 */
134 	*len = sizeof_l_onoff_truncated;
135 	get_linger(fd, l_onoff_truncated, len);
136 	printf("getsockopt(%d, SOL_SOCKET, SO_LINGER, {l_onoff=", fd);
137 	print_quoted_hex(l_onoff_truncated, *len);
138 	printf("}, [%d]) = %s\n", *len, errstr);
139 
140 	/*
141 	 * getsockopt with optlen equals to sizeof(struct linger.l_onoff):
142 	 * struct linger.l_linger is not printed.
143 	 */
144 	*len = sizeof_l_onoff;
145 	get_linger(fd, l_onoff, len);
146 	printf("getsockopt(%d, SOL_SOCKET, SO_LINGER, {l_onoff=%d}"
147 	       ", [%d]) = %s\n",
148 	       fd, l_onoff->l_onoff, *len, errstr);
149 
150 	/*
151 	 * getsockopt with optlen greater than sizeof(struct linger.l_onoff)
152 	 * but smaller than sizeof(struct linger):
153 	 * the part of struct linger.l_linger is printed in hex.
154 	 */
155 	*len = sizeof_l_linger_truncated;
156 	get_linger(fd, l_linger_truncated, len);
157 	/*
158 	 * Copy to a properly aligned structure to avoid unaligned access
159 	 * to struct linger.l_onoff field.
160 	 */
161 	memcpy(linger, l_linger_truncated, sizeof_l_linger_truncated);
162 	printf("getsockopt(%d, SOL_SOCKET, SO_LINGER, {l_onoff=%d, l_linger=",
163 	       fd, linger->l_onoff);
164 	print_quoted_hex(&linger->l_linger, sizeof_l_linger_truncated -
165 					    offsetof(struct linger, l_linger));
166 	printf("}, [%d]) = %s\n", *len, errstr);
167 
168 	/* getsockopt optval EFAULT */
169 	*len = sizeof(*linger);
170 	get_linger(fd, &linger->l_linger, len);
171 	printf("getsockopt(%d, SOL_SOCKET, SO_LINGER, %p, [%d]) = %s\n",
172 	       fd, &linger->l_linger, *len, errstr);
173 
174 	/* getsockopt optlen EFAULT */
175 	get_linger(fd, linger, len + 1);
176 	printf("getsockopt(%d, SOL_SOCKET, SO_LINGER, %p, %p) = %s\n",
177 	       fd, linger, len + 1, errstr);
178 
179 	puts("+++ exited with 0 +++");
180 	return 0;
181 }
182