| // SPDX-License-Identifier: GPL-2.0 |
| /* Copyright (c) 2021 Facebook */ |
| |
| #include <errno.h> |
| #include <linux/bpf.h> |
| #include <stdbool.h> |
| #include <bpf/bpf_helpers.h> |
| #include "bpf_misc.h" |
| |
| char _license[] SEC("license") = "GPL"; |
| |
| struct bpf_map; |
| |
| __u8 rand_vals[2500000]; |
| const __u32 nr_rand_bytes = 2500000; |
| |
| struct { |
| __uint(type, BPF_MAP_TYPE_ARRAY); |
| __uint(key_size, sizeof(__u32)); |
| /* max entries and value_size will be set programmatically. |
| * They are configurable from the userspace bench program. |
| */ |
| } array_map SEC(".maps"); |
| |
| struct { |
| __uint(type, BPF_MAP_TYPE_BLOOM_FILTER); |
| /* max entries, value_size, and # of hash functions will be set |
| * programmatically. They are configurable from the userspace |
| * bench program. |
| */ |
| __uint(map_extra, 3); |
| } bloom_map SEC(".maps"); |
| |
| struct { |
| __uint(type, BPF_MAP_TYPE_HASH); |
| /* max entries, key_size, and value_size, will be set |
| * programmatically. They are configurable from the userspace |
| * bench program. |
| */ |
| } hashmap SEC(".maps"); |
| |
| struct callback_ctx { |
| struct bpf_map *map; |
| bool update; |
| }; |
| |
| /* Tracks the number of hits, drops, and false hits */ |
| struct { |
| __u32 stats[3]; |
| } __attribute__((__aligned__(256))) percpu_stats[256]; |
| |
| const __u32 hit_key = 0; |
| const __u32 drop_key = 1; |
| const __u32 false_hit_key = 2; |
| |
| __u8 value_size; |
| |
| const volatile bool hashmap_use_bloom; |
| const volatile bool count_false_hits; |
| |
| int error = 0; |
| |
| static __always_inline void log_result(__u32 key) |
| { |
| __u32 cpu = bpf_get_smp_processor_id(); |
| |
| percpu_stats[cpu & 255].stats[key]++; |
| } |
| |
| static __u64 |
| bloom_callback(struct bpf_map *map, __u32 *key, void *val, |
| struct callback_ctx *data) |
| { |
| int err; |
| |
| if (data->update) |
| err = bpf_map_push_elem(data->map, val, 0); |
| else |
| err = bpf_map_peek_elem(data->map, val); |
| |
| if (err) { |
| error |= 1; |
| return 1; /* stop the iteration */ |
| } |
| |
| log_result(hit_key); |
| |
| return 0; |
| } |
| |
| SEC("fentry/" SYS_PREFIX "sys_getpgid") |
| int bloom_lookup(void *ctx) |
| { |
| struct callback_ctx data; |
| |
| data.map = (struct bpf_map *)&bloom_map; |
| data.update = false; |
| |
| bpf_for_each_map_elem(&array_map, bloom_callback, &data, 0); |
| |
| return 0; |
| } |
| |
| SEC("fentry/" SYS_PREFIX "sys_getpgid") |
| int bloom_update(void *ctx) |
| { |
| struct callback_ctx data; |
| |
| data.map = (struct bpf_map *)&bloom_map; |
| data.update = true; |
| |
| bpf_for_each_map_elem(&array_map, bloom_callback, &data, 0); |
| |
| return 0; |
| } |
| |
| SEC("fentry/" SYS_PREFIX "sys_getpgid") |
| int bloom_hashmap_lookup(void *ctx) |
| { |
| __u64 *result; |
| int i, err; |
| |
| __u32 index = bpf_get_prandom_u32(); |
| __u32 bitmask = (1ULL << 21) - 1; |
| |
| for (i = 0; i < 1024; i++, index += value_size) { |
| index = index & bitmask; |
| |
| if (hashmap_use_bloom) { |
| err = bpf_map_peek_elem(&bloom_map, |
| rand_vals + index); |
| if (err) { |
| if (err != -ENOENT) { |
| error |= 2; |
| return 0; |
| } |
| log_result(hit_key); |
| continue; |
| } |
| } |
| |
| result = bpf_map_lookup_elem(&hashmap, |
| rand_vals + index); |
| if (result) { |
| log_result(hit_key); |
| } else { |
| if (hashmap_use_bloom && count_false_hits) |
| log_result(false_hit_key); |
| log_result(drop_key); |
| } |
| } |
| |
| return 0; |
| } |