1 // SPDX-License-Identifier: GPL-2.0
2 #include <assert.h>
3 #include <bpf/bpf.h>
4 #include <linux/filter.h>
5 #include <stdio.h>
6 #include <stdlib.h>
7 #include <sys/sysinfo.h>
8 
9 #include "bpf_rlimit.h"
10 #include "cgroup_helpers.h"
11 
12 char bpf_log_buf[BPF_LOG_BUF_SIZE];
13 
14 #define TEST_CGROUP "/test-bpf-cgroup-storage-buf/"
15 
16 int main(int argc, char **argv)
17 {
18 	struct bpf_insn prog[] = {
19 		BPF_LD_MAP_FD(BPF_REG_1, 0), /* percpu map fd */
20 		BPF_MOV64_IMM(BPF_REG_2, 0), /* flags, not used */
21 		BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
22 			     BPF_FUNC_get_local_storage),
23 		BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_0, 0),
24 		BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, 0x1),
25 		BPF_STX_MEM(BPF_W, BPF_REG_0, BPF_REG_3, 0),
26 
27 		BPF_LD_MAP_FD(BPF_REG_1, 0), /* map fd */
28 		BPF_MOV64_IMM(BPF_REG_2, 0), /* flags, not used */
29 		BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
30 			     BPF_FUNC_get_local_storage),
31 		BPF_MOV64_IMM(BPF_REG_1, 1),
32 		BPF_STX_XADD(BPF_DW, BPF_REG_0, BPF_REG_1, 0),
33 		BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, 0),
34 		BPF_ALU64_IMM(BPF_AND, BPF_REG_1, 0x1),
35 		BPF_MOV64_REG(BPF_REG_0, BPF_REG_1),
36 		BPF_EXIT_INSN(),
37 	};
38 	size_t insns_cnt = sizeof(prog) / sizeof(struct bpf_insn);
39 	int error = EXIT_FAILURE;
40 	int map_fd, percpu_map_fd, prog_fd, cgroup_fd;
41 	struct bpf_cgroup_storage_key key;
42 	unsigned long long value;
43 	unsigned long long *percpu_value;
44 	int cpu, nproc;
45 
46 	nproc = get_nprocs_conf();
47 	percpu_value = malloc(sizeof(*percpu_value) * nproc);
48 	if (!percpu_value) {
49 		printf("Not enough memory for per-cpu area (%d cpus)\n", nproc);
50 		goto err;
51 	}
52 
53 	map_fd = bpf_create_map(BPF_MAP_TYPE_CGROUP_STORAGE, sizeof(key),
54 				sizeof(value), 0, 0);
55 	if (map_fd < 0) {
56 		printf("Failed to create map: %s\n", strerror(errno));
57 		goto out;
58 	}
59 
60 	percpu_map_fd = bpf_create_map(BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE,
61 				       sizeof(key), sizeof(value), 0, 0);
62 	if (percpu_map_fd < 0) {
63 		printf("Failed to create map: %s\n", strerror(errno));
64 		goto out;
65 	}
66 
67 	prog[0].imm = percpu_map_fd;
68 	prog[7].imm = map_fd;
69 	prog_fd = bpf_load_program(BPF_PROG_TYPE_CGROUP_SKB,
70 				   prog, insns_cnt, "GPL", 0,
71 				   bpf_log_buf, BPF_LOG_BUF_SIZE);
72 	if (prog_fd < 0) {
73 		printf("Failed to load bpf program: %s\n", bpf_log_buf);
74 		goto out;
75 	}
76 
77 	if (setup_cgroup_environment()) {
78 		printf("Failed to setup cgroup environment\n");
79 		goto err;
80 	}
81 
82 	/* Create a cgroup, get fd, and join it */
83 	cgroup_fd = create_and_get_cgroup(TEST_CGROUP);
84 	if (!cgroup_fd) {
85 		printf("Failed to create test cgroup\n");
86 		goto err;
87 	}
88 
89 	if (join_cgroup(TEST_CGROUP)) {
90 		printf("Failed to join cgroup\n");
91 		goto err;
92 	}
93 
94 	/* Attach the bpf program */
95 	if (bpf_prog_attach(prog_fd, cgroup_fd, BPF_CGROUP_INET_EGRESS, 0)) {
96 		printf("Failed to attach bpf program\n");
97 		goto err;
98 	}
99 
100 	if (bpf_map_get_next_key(map_fd, NULL, &key)) {
101 		printf("Failed to get the first key in cgroup storage\n");
102 		goto err;
103 	}
104 
105 	if (bpf_map_lookup_elem(map_fd, &key, &value)) {
106 		printf("Failed to lookup cgroup storage 0\n");
107 		goto err;
108 	}
109 
110 	for (cpu = 0; cpu < nproc; cpu++)
111 		percpu_value[cpu] = 1000;
112 
113 	if (bpf_map_update_elem(percpu_map_fd, &key, percpu_value, 0)) {
114 		printf("Failed to update the data in the cgroup storage\n");
115 		goto err;
116 	}
117 
118 	/* Every second packet should be dropped */
119 	assert(system("ping localhost -c 1 -W 1 -q > /dev/null") == 0);
120 	assert(system("ping localhost -c 1 -W 1 -q > /dev/null"));
121 	assert(system("ping localhost -c 1 -W 1 -q > /dev/null") == 0);
122 
123 	/* Check the counter in the cgroup local storage */
124 	if (bpf_map_lookup_elem(map_fd, &key, &value)) {
125 		printf("Failed to lookup cgroup storage\n");
126 		goto err;
127 	}
128 
129 	if (value != 3) {
130 		printf("Unexpected data in the cgroup storage: %llu\n", value);
131 		goto err;
132 	}
133 
134 	/* Bump the counter in the cgroup local storage */
135 	value++;
136 	if (bpf_map_update_elem(map_fd, &key, &value, 0)) {
137 		printf("Failed to update the data in the cgroup storage\n");
138 		goto err;
139 	}
140 
141 	/* Every second packet should be dropped */
142 	assert(system("ping localhost -c 1 -W 1 -q > /dev/null") == 0);
143 	assert(system("ping localhost -c 1 -W 1 -q > /dev/null"));
144 	assert(system("ping localhost -c 1 -W 1 -q > /dev/null") == 0);
145 
146 	/* Check the final value of the counter in the cgroup local storage */
147 	if (bpf_map_lookup_elem(map_fd, &key, &value)) {
148 		printf("Failed to lookup the cgroup storage\n");
149 		goto err;
150 	}
151 
152 	if (value != 7) {
153 		printf("Unexpected data in the cgroup storage: %llu\n", value);
154 		goto err;
155 	}
156 
157 	/* Check the final value of the counter in the percpu local storage */
158 
159 	for (cpu = 0; cpu < nproc; cpu++)
160 		percpu_value[cpu] = 0;
161 
162 	if (bpf_map_lookup_elem(percpu_map_fd, &key, percpu_value)) {
163 		printf("Failed to lookup the per-cpu cgroup storage\n");
164 		goto err;
165 	}
166 
167 	value = 0;
168 	for (cpu = 0; cpu < nproc; cpu++)
169 		value += percpu_value[cpu];
170 
171 	if (value != nproc * 1000 + 6) {
172 		printf("Unexpected data in the per-cpu cgroup storage\n");
173 		goto err;
174 	}
175 
176 	error = 0;
177 	printf("test_cgroup_storage:PASS\n");
178 
179 err:
180 	cleanup_cgroup_environment();
181 	free(percpu_value);
182 
183 out:
184 	return error;
185 }
186