1 // SPDX-License-Identifier: GPL-2.0-only 2 /* Copyright (c) 2020 Facebook */ 3 #include <linux/bpf.h> 4 #include <linux/fs.h> 5 #include <linux/filter.h> 6 #include <linux/kernel.h> 7 8 struct bpf_iter_seq_map_info { 9 u32 mid; 10 }; 11 12 static void *bpf_map_seq_start(struct seq_file *seq, loff_t *pos) 13 { 14 struct bpf_iter_seq_map_info *info = seq->private; 15 struct bpf_map *map; 16 17 map = bpf_map_get_curr_or_next(&info->mid); 18 if (!map) 19 return NULL; 20 21 ++*pos; 22 return map; 23 } 24 25 static void *bpf_map_seq_next(struct seq_file *seq, void *v, loff_t *pos) 26 { 27 struct bpf_iter_seq_map_info *info = seq->private; 28 struct bpf_map *map; 29 30 ++*pos; 31 ++info->mid; 32 bpf_map_put((struct bpf_map *)v); 33 map = bpf_map_get_curr_or_next(&info->mid); 34 if (!map) 35 return NULL; 36 37 return map; 38 } 39 40 struct bpf_iter__bpf_map { 41 __bpf_md_ptr(struct bpf_iter_meta *, meta); 42 __bpf_md_ptr(struct bpf_map *, map); 43 }; 44 45 DEFINE_BPF_ITER_FUNC(bpf_map, struct bpf_iter_meta *meta, struct bpf_map *map) 46 47 static int __bpf_map_seq_show(struct seq_file *seq, void *v, bool in_stop) 48 { 49 struct bpf_iter__bpf_map ctx; 50 struct bpf_iter_meta meta; 51 struct bpf_prog *prog; 52 int ret = 0; 53 54 ctx.meta = &meta; 55 ctx.map = v; 56 meta.seq = seq; 57 prog = bpf_iter_get_info(&meta, in_stop); 58 if (prog) 59 ret = bpf_iter_run_prog(prog, &ctx); 60 61 return ret; 62 } 63 64 static int bpf_map_seq_show(struct seq_file *seq, void *v) 65 { 66 return __bpf_map_seq_show(seq, v, false); 67 } 68 69 static void bpf_map_seq_stop(struct seq_file *seq, void *v) 70 { 71 if (!v) 72 (void)__bpf_map_seq_show(seq, v, true); 73 else 74 bpf_map_put((struct bpf_map *)v); 75 } 76 77 static const struct seq_operations bpf_map_seq_ops = { 78 .start = bpf_map_seq_start, 79 .next = bpf_map_seq_next, 80 .stop = bpf_map_seq_stop, 81 .show = bpf_map_seq_show, 82 }; 83 84 static const struct bpf_iter_reg bpf_map_reg_info = { 85 .target = "bpf_map", 86 .seq_ops = &bpf_map_seq_ops, 87 .init_seq_private = NULL, 88 .fini_seq_private = NULL, 89 .seq_priv_size = sizeof(struct bpf_iter_seq_map_info), 90 .ctx_arg_info_size = 1, 91 .ctx_arg_info = { 92 { offsetof(struct bpf_iter__bpf_map, map), 93 PTR_TO_BTF_ID_OR_NULL }, 94 }, 95 }; 96 97 static int __init bpf_map_iter_init(void) 98 { 99 return bpf_iter_reg_target(&bpf_map_reg_info); 100 } 101 102 late_initcall(bpf_map_iter_init); 103