1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2020 Facebook */ 3 #include "bpf_iter.h" 4 #include <bpf/bpf_helpers.h> 5 #include <bpf/bpf_tracing.h> 6 7 char _license[] SEC("license") = "GPL"; 8 9 struct key_t { 10 int a; 11 int b; 12 int c; 13 }; 14 15 struct { 16 __uint(type, BPF_MAP_TYPE_HASH); 17 __uint(max_entries, 3); 18 __type(key, struct key_t); 19 __type(value, __u64); 20 } hashmap1 SEC(".maps"); 21 22 struct { 23 __uint(type, BPF_MAP_TYPE_HASH); 24 __uint(max_entries, 3); 25 __type(key, __u64); 26 __type(value, __u64); 27 } hashmap2 SEC(".maps"); 28 29 struct { 30 __uint(type, BPF_MAP_TYPE_HASH); 31 __uint(max_entries, 3); 32 __type(key, struct key_t); 33 __type(value, __u32); 34 } hashmap3 SEC(".maps"); 35 36 /* will set before prog run */ 37 bool in_test_mode = 0; 38 39 /* will collect results during prog run */ 40 __u32 key_sum_a = 0, key_sum_b = 0, key_sum_c = 0; 41 __u64 val_sum = 0; 42 43 SEC("iter/bpf_map_elem") 44 int dump_bpf_hash_map(struct bpf_iter__bpf_map_elem *ctx) 45 { 46 struct seq_file *seq = ctx->meta->seq; 47 __u32 seq_num = ctx->meta->seq_num; 48 struct bpf_map *map = ctx->map; 49 struct key_t *key = ctx->key; 50 __u64 *val = ctx->value; 51 52 if (in_test_mode) { 53 /* test mode is used by selftests to 54 * test functionality of bpf_hash_map iter. 55 * 56 * the above hashmap1 will have correct size 57 * and will be accepted, hashmap2 and hashmap3 58 * should be rejected due to smaller key/value 59 * size. 60 */ 61 if (key == (void *)0 || val == (void *)0) 62 return 0; 63 64 key_sum_a += key->a; 65 key_sum_b += key->b; 66 key_sum_c += key->c; 67 val_sum += *val; 68 return 0; 69 } 70 71 /* non-test mode, the map is prepared with the 72 * below bpftool command sequence: 73 * bpftool map create /sys/fs/bpf/m1 type hash \ 74 * key 12 value 8 entries 3 name map1 75 * bpftool map update id 77 key 0 0 0 1 0 0 0 0 0 0 0 1 \ 76 * value 0 0 0 1 0 0 0 1 77 * bpftool map update id 77 key 0 0 0 1 0 0 0 0 0 0 0 2 \ 78 * value 0 0 0 1 0 0 0 2 79 * The bpftool iter command line: 80 * bpftool iter pin ./bpf_iter_bpf_hash_map.o /sys/fs/bpf/p1 \ 81 * map id 77 82 * The below output will be: 83 * map dump starts 84 * 77: (1000000 0 2000000) (200000001000000) 85 * 77: (1000000 0 1000000) (100000001000000) 86 * map dump ends 87 */ 88 if (seq_num == 0) 89 BPF_SEQ_PRINTF(seq, "map dump starts\n"); 90 91 if (key == (void *)0 || val == (void *)0) { 92 BPF_SEQ_PRINTF(seq, "map dump ends\n"); 93 return 0; 94 } 95 96 BPF_SEQ_PRINTF(seq, "%d: (%x %d %x) (%llx)\n", map->id, 97 key->a, key->b, key->c, *val); 98 99 return 0; 100 } 101