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1 /*
2  * Copyright (c) 2015 Dmitry V. Levin <ldv@altlinux.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. The name of the author may not be used to endorse or promote products
14  *    derived from this software without specific prior written permission.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #ifdef HAVE_CONFIG_H
29 # include "config.h"
30 #endif
31 
32 #include <stdio.h>
33 #include <stdint.h>
34 #include <unistd.h>
35 #include <sys/syscall.h>
36 
37 #if defined HAVE_UNION_BPF_ATTR_LOG_BUF && defined __NR_bpf
38 # include <linux/bpf.h>
39 
40 static const struct bpf_insn insns[] = {
41 	{ .code = BPF_JMP | BPF_EXIT }
42 };
43 
44 static char log_buf[4096];
45 
46 static int
map_create(void)47 map_create(void)
48 {
49 	union bpf_attr attr = {
50 		.key_size = 4,
51 		.value_size = 8,
52 		.max_entries = 256
53 	};
54 	return syscall(__NR_bpf, BPF_MAP_CREATE, &attr, sizeof(attr));
55 }
56 
57 static int
map_any(int cmd)58 map_any(int cmd)
59 {
60 	union bpf_attr attr = {
61 		.map_fd = -1,
62 		.key = 0xdeadbeef,
63 		.value = 0xbadc0ded
64 	};
65 	return syscall(__NR_bpf, cmd, &attr, sizeof(attr));
66 }
67 
68 static int
prog_load(void)69 prog_load(void)
70 {
71 	union bpf_attr attr = {
72 		.insn_cnt = sizeof(insns) / sizeof(insns[0]),
73 		.insns = (unsigned long) insns,
74 		.license = (unsigned long) "GPL",
75 		.log_level = 42,
76 		.log_size = sizeof(log_buf),
77 		.log_buf = (unsigned long) log_buf
78 	};
79 	return syscall(__NR_bpf, BPF_PROG_LOAD, &attr, sizeof(attr));
80 }
81 
82 int
main(void)83 main(void)
84 {
85 	if (!map_create())
86 		return 77;
87 	printf("bpf\\(BPF_MAP_CREATE, "
88 	       "\\{map_type=BPF_MAP_TYPE_UNSPEC, key_size=4, value_size=8, max_entries=256\\}, "
89 	       "%u\\) += -1 .*\n",
90 		(unsigned) sizeof(union bpf_attr));
91 
92 	if (!map_any(BPF_MAP_LOOKUP_ELEM))
93 		return 77;
94 	printf("bpf\\(BPF_MAP_LOOKUP_ELEM, "
95 	       "\\{map_fd=-1, key=0xdeadbeef\\}, %u\\) += -1 .*\n",
96 		(unsigned) sizeof(union bpf_attr));
97 
98 	if (!map_any(BPF_MAP_UPDATE_ELEM))
99 		return 77;
100 	printf("bpf\\(BPF_MAP_UPDATE_ELEM, "
101 	       "\\{map_fd=-1, key=0xdeadbeef, value=0xbadc0ded, flags=BPF_ANY\\}, "
102 	       "%u\\) += -1 .*\n",
103 		(unsigned) sizeof(union bpf_attr));
104 
105 	if (!map_any(BPF_MAP_DELETE_ELEM))
106 		return 77;
107 	printf("bpf\\(BPF_MAP_DELETE_ELEM, "
108 	       "\\{map_fd=-1, key=0xdeadbeef\\}, %u\\) += -1 .*\n",
109 		(unsigned) sizeof(union bpf_attr));
110 
111 	if (!map_any(BPF_MAP_GET_NEXT_KEY))
112 		return 77;
113 	printf("bpf\\(BPF_MAP_GET_NEXT_KEY, "
114 	       "\\{map_fd=-1, key=0xdeadbeef\\}, %u\\) += -1 .*\n",
115 		(unsigned) sizeof(union bpf_attr));
116 
117 	if (!prog_load())
118 		return 77;
119 	printf("bpf\\(BPF_PROG_LOAD, "
120 	       "\\{prog_type=BPF_PROG_TYPE_UNSPEC, insn_cnt=1, insns=%p, "
121 	       "license=\"GPL\", log_level=42, log_size=4096, log_buf=%p, "
122 	       "kern_version=0\\}, %u\\) += -1 .*\n",
123 		insns, log_buf, (unsigned) sizeof(union bpf_attr));
124 
125 	return 0;
126 }
127 
128 #else
129 
130 int
main(void)131 main(void)
132 {
133 	return 77;
134 }
135 
136 #endif
137