xref: /linux/samples/bpf/test_map_in_map_user.c (revision 0d3b051adbb72ed81956447d0d1e54d5943ee6f5)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2017 Facebook
4  */
5 #include <sys/resource.h>
6 #include <sys/socket.h>
7 #include <arpa/inet.h>
8 #include <stdint.h>
9 #include <assert.h>
10 #include <errno.h>
11 #include <stdlib.h>
12 #include <stdio.h>
13 #include <bpf/bpf.h>
14 #include <bpf/libbpf.h>
15 
16 static int map_fd[7];
17 
18 #define PORT_A		(map_fd[0])
19 #define PORT_H		(map_fd[1])
20 #define REG_RESULT_H	(map_fd[2])
21 #define INLINE_RESULT_H	(map_fd[3])
22 #define A_OF_PORT_A	(map_fd[4]) /* Test case #0 */
23 #define H_OF_PORT_A	(map_fd[5]) /* Test case #1 */
24 #define H_OF_PORT_H	(map_fd[6]) /* Test case #2 */
25 
26 static const char * const test_names[] = {
27 	"Array of Array",
28 	"Hash of Array",
29 	"Hash of Hash",
30 };
31 
32 #define NR_TESTS (sizeof(test_names) / sizeof(*test_names))
33 
34 static void check_map_id(int inner_map_fd, int map_in_map_fd, uint32_t key)
35 {
36 	struct bpf_map_info info = {};
37 	uint32_t info_len = sizeof(info);
38 	int ret, id;
39 
40 	ret = bpf_obj_get_info_by_fd(inner_map_fd, &info, &info_len);
41 	assert(!ret);
42 
43 	ret = bpf_map_lookup_elem(map_in_map_fd, &key, &id);
44 	assert(!ret);
45 	assert(id == info.id);
46 }
47 
48 static void populate_map(uint32_t port_key, int magic_result)
49 {
50 	int ret;
51 
52 	ret = bpf_map_update_elem(PORT_A, &port_key, &magic_result, BPF_ANY);
53 	assert(!ret);
54 
55 	ret = bpf_map_update_elem(PORT_H, &port_key, &magic_result,
56 				  BPF_NOEXIST);
57 	assert(!ret);
58 
59 	ret = bpf_map_update_elem(A_OF_PORT_A, &port_key, &PORT_A, BPF_ANY);
60 	assert(!ret);
61 	check_map_id(PORT_A, A_OF_PORT_A, port_key);
62 
63 	ret = bpf_map_update_elem(H_OF_PORT_A, &port_key, &PORT_A, BPF_NOEXIST);
64 	assert(!ret);
65 	check_map_id(PORT_A, H_OF_PORT_A, port_key);
66 
67 	ret = bpf_map_update_elem(H_OF_PORT_H, &port_key, &PORT_H, BPF_NOEXIST);
68 	assert(!ret);
69 	check_map_id(PORT_H, H_OF_PORT_H, port_key);
70 }
71 
72 static void test_map_in_map(void)
73 {
74 	struct sockaddr_in6 in6 = { .sin6_family = AF_INET6 };
75 	uint32_t result_key = 0, port_key;
76 	int result, inline_result;
77 	int magic_result = 0xfaceb00c;
78 	int ret;
79 	int i;
80 
81 	port_key = rand() & 0x00FF;
82 	populate_map(port_key, magic_result);
83 
84 	in6.sin6_addr.s6_addr16[0] = 0xdead;
85 	in6.sin6_addr.s6_addr16[1] = 0xbeef;
86 	in6.sin6_port = port_key;
87 
88 	for (i = 0; i < NR_TESTS; i++) {
89 		printf("%s: ", test_names[i]);
90 
91 		in6.sin6_addr.s6_addr16[7] = i;
92 		ret = connect(-1, (struct sockaddr *)&in6, sizeof(in6));
93 		assert(ret == -1 && errno == EBADF);
94 
95 		ret = bpf_map_lookup_elem(REG_RESULT_H, &result_key, &result);
96 		assert(!ret);
97 
98 		ret = bpf_map_lookup_elem(INLINE_RESULT_H, &result_key,
99 					  &inline_result);
100 		assert(!ret);
101 
102 		if (result != magic_result || inline_result != magic_result) {
103 			printf("Error. result:%d inline_result:%d\n",
104 			       result, inline_result);
105 			exit(1);
106 		}
107 
108 		bpf_map_delete_elem(REG_RESULT_H, &result_key);
109 		bpf_map_delete_elem(INLINE_RESULT_H, &result_key);
110 
111 		printf("Pass\n");
112 	}
113 }
114 
115 int main(int argc, char **argv)
116 {
117 	struct bpf_link *link = NULL;
118 	struct bpf_program *prog;
119 	struct bpf_object *obj;
120 	char filename[256];
121 
122 	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
123 	obj = bpf_object__open_file(filename, NULL);
124 	if (libbpf_get_error(obj)) {
125 		fprintf(stderr, "ERROR: opening BPF object file failed\n");
126 		return 0;
127 	}
128 
129 	prog = bpf_object__find_program_by_name(obj, "trace_sys_connect");
130 	if (!prog) {
131 		printf("finding a prog in obj file failed\n");
132 		goto cleanup;
133 	}
134 
135 	/* load BPF program */
136 	if (bpf_object__load(obj)) {
137 		fprintf(stderr, "ERROR: loading BPF object file failed\n");
138 		goto cleanup;
139 	}
140 
141 	map_fd[0] = bpf_object__find_map_fd_by_name(obj, "port_a");
142 	map_fd[1] = bpf_object__find_map_fd_by_name(obj, "port_h");
143 	map_fd[2] = bpf_object__find_map_fd_by_name(obj, "reg_result_h");
144 	map_fd[3] = bpf_object__find_map_fd_by_name(obj, "inline_result_h");
145 	map_fd[4] = bpf_object__find_map_fd_by_name(obj, "a_of_port_a");
146 	map_fd[5] = bpf_object__find_map_fd_by_name(obj, "h_of_port_a");
147 	map_fd[6] = bpf_object__find_map_fd_by_name(obj, "h_of_port_h");
148 	if (map_fd[0] < 0 || map_fd[1] < 0 || map_fd[2] < 0 ||
149 	    map_fd[3] < 0 || map_fd[4] < 0 || map_fd[5] < 0 || map_fd[6] < 0) {
150 		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
151 		goto cleanup;
152 	}
153 
154 	link = bpf_program__attach(prog);
155 	if (libbpf_get_error(link)) {
156 		fprintf(stderr, "ERROR: bpf_program__attach failed\n");
157 		link = NULL;
158 		goto cleanup;
159 	}
160 
161 	test_map_in_map();
162 
163 cleanup:
164 	bpf_link__destroy(link);
165 	bpf_object__close(obj);
166 	return 0;
167 }
168