tools/testing/selftests/bpf/test_cgroup_storage.c

   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_DW, BPF_REG_3, BPF_REG_0, 0),
  24                 BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, 0x1),
  25                 BPF_STX_MEM(BPF_DW, 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_DW, 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         cgroup_fd = cgroup_setup_and_join(TEST_CGROUP);
  78
  79         /* Attach the bpf program */
  80         if (bpf_prog_attach(prog_fd, cgroup_fd, BPF_CGROUP_INET_EGRESS, 0)) {
  81                 printf("Failed to attach bpf program\n");
  82                 goto err;
  83         }
  84
  85         if (bpf_map_get_next_key(map_fd, NULL, &key)) {
  86                 printf("Failed to get the first key in cgroup storage\n");
  87                 goto err;
  88         }
  89
  90         if (bpf_map_lookup_elem(map_fd, &key, &value)) {
  91                 printf("Failed to lookup cgroup storage 0\n");
  92                 goto err;
  93         }
  94
  95         for (cpu = 0; cpu < nproc; cpu++)
  96                 percpu_value[cpu] = 1000;
  97
  98         if (bpf_map_update_elem(percpu_map_fd, &key, percpu_value, 0)) {
  99                 printf("Failed to update the data in the cgroup storage\n");
 100                 goto err;
 101         }
 102
 103         /* Every second packet should be dropped */
 104         assert(system("ping localhost -c 1 -W 1 -q > /dev/null") == 0);
 105         assert(system("ping localhost -c 1 -W 1 -q > /dev/null"));
 106         assert(system("ping localhost -c 1 -W 1 -q > /dev/null") == 0);
 107
 108         /* Check the counter in the cgroup local storage */
 109         if (bpf_map_lookup_elem(map_fd, &key, &value)) {
 110                 printf("Failed to lookup cgroup storage\n");
 111                 goto err;
 112         }
 113
 114         if (value != 3) {
 115                 printf("Unexpected data in the cgroup storage: %llu\n", value);
 116                 goto err;
 117         }
 118
 119         /* Bump the counter in the cgroup local storage */
 120         value++;
 121         if (bpf_map_update_elem(map_fd, &key, &value, 0)) {
 122                 printf("Failed to update the data in the cgroup storage\n");
 123                 goto err;
 124         }
 125
 126         /* Every second packet should be dropped */
 127         assert(system("ping localhost -c 1 -W 1 -q > /dev/null") == 0);
 128         assert(system("ping localhost -c 1 -W 1 -q > /dev/null"));
 129         assert(system("ping localhost -c 1 -W 1 -q > /dev/null") == 0);
 130
 131         /* Check the final value of the counter in the cgroup local storage */
 132         if (bpf_map_lookup_elem(map_fd, &key, &value)) {
 133                 printf("Failed to lookup the cgroup storage\n");
 134                 goto err;
 135         }
 136
 137         if (value != 7) {
 138                 printf("Unexpected data in the cgroup storage: %llu\n", value);
 139                 goto err;
 140         }
 141
 142         /* Check the final value of the counter in the percpu local storage */
 143
 144         for (cpu = 0; cpu < nproc; cpu++)
 145                 percpu_value[cpu] = 0;
 146
 147         if (bpf_map_lookup_elem(percpu_map_fd, &key, percpu_value)) {
 148                 printf("Failed to lookup the per-cpu cgroup storage\n");
 149                 goto err;
 150         }
 151
 152         value = 0;
 153         for (cpu = 0; cpu < nproc; cpu++)
 154                 value += percpu_value[cpu];
 155
 156         if (value != nproc * 1000 + 6) {
 157                 printf("Unexpected data in the per-cpu cgroup storage\n");
 158                 goto err;
 159         }
 160
 161         error = 0;
 162         printf("test_cgroup_storage:PASS\n");
 163
 164 err:
 165         cleanup_cgroup_environment();
 166         free(percpu_value);
 167
 168 out:
 169         return error;
 170 }