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1 /*
2  * Check decoding of readv and writev syscalls.
3  *
4  * Copyright (c) 2016 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 <assert.h>
33 #include <stdio.h>
34 #include <unistd.h>
35 #include <sys/uio.h>
36 
37 int
main(void)38 main(void)
39 {
40 	tprintf("%s", "");
41 
42 	int fds[2];
43 	pipe_maxfd(fds);
44 
45 	static const char w0_c[] = "012";
46 	const char *w0_d = hexdump_strdup(w0_c);
47 	void *w0 = tail_memdup(w0_c, LENGTH_OF(w0_c));
48 
49 	const void *efault = w0 + LENGTH_OF(w0_c);
50 
51 	static const char w1_c[] = "34567";
52 	const char *w1_d = hexdump_strdup(w1_c);
53 	void *w1 = tail_memdup(w1_c, LENGTH_OF(w1_c));
54 
55 	static const char w2_c[] = "89abcde";
56 	const char *w2_d = hexdump_strdup(w2_c);
57 	void *w2 = tail_memdup(w2_c, LENGTH_OF(w2_c));
58 	long rc;
59 
60 	rc = writev(fds[1], efault, 42);
61 	tprintf("writev(%d, %p, 42) = %ld %s (%m)\n",
62 		fds[1], efault, rc, errno2name());
63 
64 	rc = readv(fds[0], efault, 42);
65 	tprintf("readv(%d, %p, 42) = %ld %s (%m)\n",
66 		fds[0], efault, rc, errno2name());
67 
68 	static const char r0_c[] = "01234567";
69 	const char *r0_d = hexdump_strdup(r0_c);
70 	static const char r1_c[] = "89abcde";
71 	const char *r1_d = hexdump_strdup(r1_c);
72 
73 	const struct iovec w_iov_[] = {
74 		{
75 			.iov_base = w0,
76 			.iov_len = LENGTH_OF(w0_c)
77 		}, {
78 			.iov_base = w1,
79 			.iov_len = LENGTH_OF(w1_c)
80 		}, {
81 			.iov_base = w2,
82 			.iov_len = LENGTH_OF(w2_c)
83 		}
84 	};
85 	const struct iovec *w_iov = tail_memdup(w_iov_, sizeof(w_iov_));
86 
87 	tprintf("writev(%d, [], 0) = %ld\n",
88 		fds[1], (long) writev(fds[1], w_iov, 0));
89 
90 	rc = writev(fds[1], w_iov + ARRAY_SIZE(w_iov_) - 1, 2);
91 	tprintf("writev(%d, [{iov_base=\"%s\", iov_len=%u}, %p], 2)"
92 		" = %ld %s (%m)\n",
93 		fds[1], w2_c, LENGTH_OF(w2_c), w_iov + ARRAY_SIZE(w_iov_),
94 		rc, errno2name());
95 
96 	const unsigned int w_len =
97 		LENGTH_OF(w0_c) + LENGTH_OF(w1_c) + LENGTH_OF(w2_c);
98 
99 	assert(writev(fds[1], w_iov, ARRAY_SIZE(w_iov_)) == (int) w_len);
100 	close(fds[1]);
101 	tprintf("writev(%d, [{iov_base=\"%s\", iov_len=%u}"
102 		", {iov_base=\"%s\", iov_len=%u}"
103 		", {iov_base=\"%s\", iov_len=%u}], %u) = %u\n"
104 		" * %u bytes in buffer 0\n"
105 		" | 00000 %-49s  %-16s |\n"
106 		" * %u bytes in buffer 1\n"
107 		" | 00000 %-49s  %-16s |\n"
108 		" * %u bytes in buffer 2\n"
109 		" | 00000 %-49s  %-16s |\n",
110 		fds[1], w0_c, LENGTH_OF(w0_c), w1_c, LENGTH_OF(w1_c),
111 		w2_c, LENGTH_OF(w2_c), ARRAY_SIZE(w_iov_), w_len,
112 		LENGTH_OF(w0_c), w0_d, w0_c,
113 		LENGTH_OF(w1_c), w1_d, w1_c, LENGTH_OF(w2_c), w2_d, w2_c);
114 
115 	const unsigned int r_len = (w_len + 1) / 2;
116 	void *r0 = tail_alloc(r_len);
117 	const struct iovec r0_iov_[] = {
118 		{
119 			.iov_base = r0,
120 			.iov_len = r_len
121 		}
122 	};
123 	const struct iovec *r_iov = tail_memdup(r0_iov_, sizeof(r0_iov_));
124 
125 	assert(readv(fds[0], r_iov, ARRAY_SIZE(r0_iov_)) == (int) r_len);
126 	tprintf("readv(%d, [{iov_base=\"%s\", iov_len=%u}], %u) = %u\n"
127 		" * %u bytes in buffer 0\n"
128 		" | 00000 %-49s  %-16s |\n",
129 		fds[0],
130 		r0_c, r_len, ARRAY_SIZE(r0_iov_), r_len, r_len, r0_d, r0_c);
131 
132 	void *r1 = tail_alloc(r_len);
133 	void *r2 = tail_alloc(w_len);
134 	const struct iovec r1_iov_[] = {
135 		{
136 			.iov_base = r1,
137 			.iov_len = r_len
138 		},
139 		{
140 			.iov_base = r2,
141 			.iov_len = w_len
142 		}
143 	};
144 	r_iov = tail_memdup(r1_iov_, sizeof(r1_iov_));
145 
146 	assert(readv(fds[0], r_iov, ARRAY_SIZE(r1_iov_)) == (int) w_len - (int) r_len);
147 	tprintf("readv(%d, [{iov_base=\"%s\", iov_len=%u}"
148 		", {iov_base=\"\", iov_len=%u}], %u) = %u\n"
149 		" * %u bytes in buffer 0\n"
150 		" | 00000 %-49s  %-16s |\n",
151 		fds[0], r1_c, r_len, w_len, ARRAY_SIZE(r1_iov_), w_len - r_len,
152 		w_len - r_len, r1_d, r1_c);
153 	close(fds[0]);
154 
155 	tprintf("+++ exited with 0 +++\n");
156 	return 0;
157 }
158