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1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (c) 2019 Richard Palethorpe <rpalethorpe@suse.com>
4  *
5  * Trivial Extended Berkeley Packet Filter (eBPF) test.
6  *
7  * Sanity check creating and updating maps.
8  */
9 /*
10  * If test is executed in a loop and limit for locked memory (ulimit -l) is
11  * too low bpf() call can fail with EPERM due to deffered freeing.
12  */
13 
14 #include <limits.h>
15 #include <string.h>
16 
17 #include "config.h"
18 #include "tst_test.h"
19 #include "bpf_common.h"
20 
21 #define VAL_SZ 1024
22 
23 static void *key4;
24 static void *key8;
25 static char *val_set;
26 static char *val_get;
27 static union bpf_attr *attr;
28 
29 struct map_type {
30 	uint32_t id;
31 	char *name;
32 	int key_size;
33 	void **key;
34 };
35 
36 static const struct map_type map_types[] = {
37 	{BPF_MAP_TYPE_HASH, "hash", 8, &key8},
38 	{BPF_MAP_TYPE_ARRAY, "array", 4, &key4}
39 };
40 
run(unsigned int n)41 void run(unsigned int n)
42 {
43 	int fd, i;
44 	void *key = *map_types[n].key;
45 
46 	memset(attr, 0, sizeof(*attr));
47 	attr->map_type = map_types[n].id;
48 	attr->key_size = map_types[n].key_size;
49 	attr->value_size = VAL_SZ;
50 	attr->max_entries = 1;
51 
52 	fd = bpf_map_create(attr);
53 	tst_res(TPASS, "Created %s map", map_types[n].name);
54 
55 	memset(attr, 0, sizeof(*attr));
56 	attr->map_fd = fd;
57 	attr->key = ptr_to_u64(key);
58 	attr->value = ptr_to_u64(val_get);
59 
60 	memset(val_get, 'x', VAL_SZ);
61 
62 	TEST(bpf(BPF_MAP_LOOKUP_ELEM, attr, sizeof(*attr)));
63 
64 	switch (map_types[n].id) {
65 	case BPF_MAP_TYPE_HASH:
66 		if (TST_RET != -1 || TST_ERR != ENOENT) {
67 			tst_res(TFAIL | TTERRNO,
68 				"Empty hash map lookup should fail with ENOENT");
69 		} else {
70 			tst_res(TPASS | TTERRNO, "Empty hash map lookup");
71 		}
72 	break;
73 	case BPF_MAP_TYPE_ARRAY:
74 		if (TST_RET != -1) {
75 			for (i = 0; i < VAL_SZ; i++) {
76 				if (val_get[i] != 0) {
77 					tst_res(TFAIL,
78 						"Preallocated array map val not zero");
79 					break;
80 				}
81 			}
82 			if (i < VAL_SZ)
83 				tst_res(TPASS, "Preallocated array map lookup");
84 		} else {
85 			tst_res(TFAIL | TTERRNO, "Prellocated array map lookup");
86 		}
87 	break;
88 	}
89 
90 	memset(attr, 0, sizeof(*attr));
91 	attr->map_fd = fd;
92 	attr->key = ptr_to_u64(key);
93 	attr->value = ptr_to_u64(val_set);
94 	attr->flags = BPF_ANY;
95 
96 	TEST(bpf(BPF_MAP_UPDATE_ELEM, attr, sizeof(*attr)));
97 	if (TST_RET == -1) {
98 		tst_brk(TFAIL | TTERRNO,
99 			"Update %s map element",
100 			map_types[n].name);
101 	} else {
102 		tst_res(TPASS,
103 			"Update %s map element",
104 			map_types[n].name);
105 	}
106 
107 	memset(attr, 0, sizeof(*attr));
108 	attr->map_fd = fd;
109 	attr->key = ptr_to_u64(key);
110 	attr->value = ptr_to_u64(val_get);
111 
112 	TEST(bpf(BPF_MAP_LOOKUP_ELEM, attr, sizeof(*attr)));
113 	if (TST_RET == -1) {
114 		tst_res(TFAIL | TTERRNO,
115 			"%s map lookup missing",
116 			map_types[n].name);
117 	} else if (memcmp(val_set, val_get, (size_t) VAL_SZ)) {
118 		tst_res(TFAIL,
119 			"%s map lookup returned different value",
120 			map_types[n].name);
121 	} else {
122 		tst_res(TPASS, "%s map lookup", map_types[n].name);
123 	}
124 
125 	SAFE_CLOSE(fd);
126 }
127 
setup(void)128 static void setup(void)
129 {
130 	unsigned int i;
131 
132 	rlimit_bump_memlock();
133 
134 	memcpy(key8, "12345678", 8);
135 	memset(key4, 0, 4);
136 
137 	for (i = 0; i < VAL_SZ; i++)
138 		val_set[i] = i % 256;
139 }
140 
141 static struct tst_test test = {
142 	.tcnt = ARRAY_SIZE(map_types),
143 	.test = run,
144 	.setup = setup,
145 	.min_kver = "3.19",
146 	.bufs = (struct tst_buffers []) {
147 		{&key4, .size = 4},
148 		{&key8, .size = 8},
149 		{&val_set, .size = VAL_SZ},
150 		{&val_get, .size = VAL_SZ},
151 		{&attr, .size = sizeof(*attr)},
152 		{},
153 	},
154 };
155