94 lines
1.9 KiB
C
94 lines
1.9 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Copyright (C) 2023. Huawei Technologies Co., Ltd */
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#include <linux/bpf.h>
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#include <time.h>
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#include <bpf/bpf_helpers.h>
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#include "bpf_misc.h"
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struct inner_map_type {
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__uint(type, BPF_MAP_TYPE_ARRAY);
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__uint(key_size, 4);
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__uint(value_size, 4);
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__uint(max_entries, 1);
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} inner_map SEC(".maps");
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struct {
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__uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
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__type(key, int);
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__type(value, int);
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__uint(max_entries, 1);
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__array(values, struct inner_map_type);
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} outer_array_map SEC(".maps") = {
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.values = {
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[0] = &inner_map,
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},
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};
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struct {
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__uint(type, BPF_MAP_TYPE_HASH_OF_MAPS);
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__type(key, int);
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__type(value, int);
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__uint(max_entries, 1);
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__array(values, struct inner_map_type);
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} outer_htab_map SEC(".maps") = {
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.values = {
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[0] = &inner_map,
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},
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};
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char _license[] SEC("license") = "GPL";
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int tgid = 0;
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static int acc_map_in_map(void *outer_map)
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{
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int i, key, value = 0xdeadbeef;
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void *inner_map;
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if ((bpf_get_current_pid_tgid() >> 32) != tgid)
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return 0;
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/* Find nonexistent inner map */
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key = 1;
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inner_map = bpf_map_lookup_elem(outer_map, &key);
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if (inner_map)
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return 0;
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/* Find the old inner map */
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key = 0;
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inner_map = bpf_map_lookup_elem(outer_map, &key);
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if (!inner_map)
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return 0;
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/* Wait for the old inner map to be replaced */
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for (i = 0; i < 2048; i++)
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bpf_map_update_elem(inner_map, &key, &value, 0);
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return 0;
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}
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SEC("?kprobe/" SYS_PREFIX "sys_getpgid")
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int access_map_in_array(void *ctx)
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{
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return acc_map_in_map(&outer_array_map);
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}
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SEC("?fentry.s/" SYS_PREFIX "sys_getpgid")
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int sleepable_access_map_in_array(void *ctx)
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{
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return acc_map_in_map(&outer_array_map);
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}
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SEC("?kprobe/" SYS_PREFIX "sys_getpgid")
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int access_map_in_htab(void *ctx)
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{
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return acc_map_in_map(&outer_htab_map);
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}
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SEC("?fentry.s/" SYS_PREFIX "sys_getpgid")
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int sleepable_access_map_in_htab(void *ctx)
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{
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return acc_map_in_map(&outer_htab_map);
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}
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