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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 "lapi/bpf.h"
20 #include "bpf_common.h"
21 
22 #define VAL_SZ 1024
23 
24 static void *key4;
25 static void *key8;
26 static char *val_set;
27 static char *val_get;
28 static union bpf_attr *attr;
29 
30 struct map_type {
31 	uint32_t id;
32 	char *name;
33 	int key_size;
34 	void **key;
35 };
36 
37 static const struct map_type map_types[] = {
38 	{BPF_MAP_TYPE_HASH, "hash", 8, &key8},
39 	{BPF_MAP_TYPE_ARRAY, "array", 4, &key4}
40 };
41 
run(unsigned int n)42 void run(unsigned int n)
43 {
44 	int fd, i;
45 	void *key = *map_types[n].key;
46 
47 	memset(attr, 0, sizeof(*attr));
48 	attr->map_type = map_types[n].id;
49 	attr->key_size = map_types[n].key_size;
50 	attr->value_size = VAL_SZ;
51 	attr->max_entries = 1;
52 
53 	fd = bpf_map_create(attr);
54 	tst_res(TPASS, "Created %s map", map_types[n].name);
55 
56 	memset(attr, 0, sizeof(*attr));
57 	attr->map_fd = fd;
58 	attr->key = ptr_to_u64(key);
59 	attr->value = ptr_to_u64(val_get);
60 
61 	memset(val_get, 'x', VAL_SZ);
62 
63 	TEST(bpf(BPF_MAP_LOOKUP_ELEM, attr, sizeof(*attr)));
64 
65 	switch (map_types[n].id) {
66 	case BPF_MAP_TYPE_HASH:
67 		if (TST_RET != -1 || TST_ERR != ENOENT) {
68 			tst_res(TFAIL | TTERRNO,
69 				"Empty hash map lookup should fail with ENOENT");
70 		} else {
71 			tst_res(TPASS | TTERRNO, "Empty hash map lookup");
72 		}
73 	break;
74 	case BPF_MAP_TYPE_ARRAY:
75 		if (TST_RET != -1) {
76 			for (i = 0; i < VAL_SZ; i++) {
77 				if (val_get[i] != 0) {
78 					tst_res(TFAIL,
79 						"Preallocated array map val not zero");
80 					break;
81 				}
82 			}
83 			if (i < VAL_SZ)
84 				tst_res(TPASS, "Preallocated array map lookup");
85 		} else {
86 			tst_res(TFAIL | TERRNO, "Prellocated array map lookup");
87 		}
88 	break;
89 	}
90 
91 	memset(attr, 0, sizeof(*attr));
92 	attr->map_fd = fd;
93 	attr->key = ptr_to_u64(key);
94 	attr->value = ptr_to_u64(val_set);
95 	attr->flags = BPF_ANY;
96 
97 	TEST(bpf(BPF_MAP_UPDATE_ELEM, attr, sizeof(*attr)));
98 	if (TST_RET == -1) {
99 		tst_brk(TFAIL | TTERRNO,
100 			"Update %s map element",
101 			map_types[n].name);
102 	} else {
103 		tst_res(TPASS,
104 			"Update %s map element",
105 			map_types[n].name);
106 	}
107 
108 	memset(attr, 0, sizeof(*attr));
109 	attr->map_fd = fd;
110 	attr->key = ptr_to_u64(key);
111 	attr->value = ptr_to_u64(val_get);
112 
113 	TEST(bpf(BPF_MAP_LOOKUP_ELEM, attr, sizeof(*attr)));
114 	if (TST_RET == -1) {
115 		tst_res(TFAIL | TTERRNO,
116 			"%s map lookup missing",
117 			map_types[n].name);
118 	} else if (memcmp(val_set, val_get, (size_t) VAL_SZ)) {
119 		tst_res(TFAIL,
120 			"%s map lookup returned different value",
121 			map_types[n].name);
122 	} else {
123 		tst_res(TPASS, "%s map lookup", map_types[n].name);
124 	}
125 
126 	SAFE_CLOSE(fd);
127 }
128 
setup(void)129 static void setup(void)
130 {
131 	unsigned int i;
132 
133 	rlimit_bump_memlock();
134 
135 	memcpy(key8, "12345678", 8);
136 	memset(key4, 0, 4);
137 
138 	for (i = 0; i < VAL_SZ; i++)
139 		val_set[i] = i % 256;
140 }
141 
142 static struct tst_test test = {
143 	.tcnt = ARRAY_SIZE(map_types),
144 	.test = run,
145 	.setup = setup,
146 	.min_kver = "3.19",
147 	.bufs = (struct tst_buffers []) {
148 		{&key4, .size = 4},
149 		{&key8, .size = 8},
150 		{&val_set, .size = VAL_SZ},
151 		{&val_get, .size = VAL_SZ},
152 		{&attr, .size = sizeof(*attr)},
153 		{},
154 	},
155 };
156