// SPDX-License-Identifier: GPL-2.0-only/* Copyright (c) 2020 Facebook */#include <linux/bpf.h>#include <linux/fs.h>#include <linux/filter.h>#include <linux/kernel.h>#include <linux/btf_ids.h> struct bpf_iter_seq_map_info {	u32 map_id;}; static void *bpf_map_seq_start(struct seq_file *seq, loff_t *pos){	struct bpf_iter_seq_map_info *info = seq->private;	struct bpf_map *map; 	map = bpf_map_get_curr_or_next(&info->map_id);	if (!map)		return NULL; 	if (*pos == 0)		++*pos;	return map;} static void *bpf_map_seq_next(struct seq_file *seq, void *v, loff_t *pos){	struct bpf_iter_seq_map_info *info = seq->private; 	++*pos;	++info->map_id;	bpf_map_put((struct bpf_map *)v);	return bpf_map_get_curr_or_next(&info->map_id);} struct bpf_iter__bpf_map {	__bpf_md_ptr(struct bpf_iter_meta *, meta);	__bpf_md_ptr(struct bpf_map *, map);}; DEFINE_BPF_ITER_FUNC(bpf_map, struct bpf_iter_meta *meta, struct bpf_map *map) static int __bpf_map_seq_show(struct seq_file *seq, void *v, bool in_stop){	struct bpf_iter__bpf_map ctx;	struct bpf_iter_meta meta;	struct bpf_prog *prog;	int ret = 0; 	ctx.meta = &meta;	ctx.map = v;	meta.seq = seq;	prog = bpf_iter_get_info(&meta, in_stop);	if (prog)		ret = bpf_iter_run_prog(prog, &ctx); 	return ret;} static int bpf_map_seq_show(struct seq_file *seq, void *v){	return __bpf_map_seq_show(seq, v, false);} static void bpf_map_seq_stop(struct seq_file *seq, void *v){	if (!v)		(void)__bpf_map_seq_show(seq, v, true);	else		bpf_map_put((struct bpf_map *)v);} static const struct seq_operations bpf_map_seq_ops = {	.start	= bpf_map_seq_start,	.next	= bpf_map_seq_next,	.stop	= bpf_map_seq_stop,	.show	= bpf_map_seq_show,}; BTF_ID_LIST(btf_bpf_map_id)BTF_ID(struct, bpf_map) static const struct bpf_iter_seq_info bpf_map_seq_info = {	.seq_ops		= &bpf_map_seq_ops,	.init_seq_private	= NULL,	.fini_seq_private	= NULL,	.seq_priv_size		= sizeof(struct bpf_iter_seq_map_info),}; static struct bpf_iter_reg bpf_map_reg_info = {	.target			= "bpf_map",	.ctx_arg_info_size	= 1,	.ctx_arg_info		= {		{ offsetof(struct bpf_iter__bpf_map, map),		  PTR_TO_BTF_ID_OR_NULL },	},	.seq_info		= &bpf_map_seq_info,}; static int bpf_iter_attach_map(struct bpf_prog *prog,			       union bpf_iter_link_info *linfo,			       struct bpf_iter_aux_info *aux){	u32 key_acc_size, value_acc_size, key_size, value_size;	struct bpf_map *map;	bool is_percpu = false;	int err = -EINVAL; 	if (!linfo->map.map_fd)		return -EBADF; 	map = bpf_map_get_with_uref(linfo->map.map_fd);	if (IS_ERR(map))		return PTR_ERR(map); 	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||	    map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY)		is_percpu = true;	else if (map->map_type != BPF_MAP_TYPE_HASH &&		 map->map_type != BPF_MAP_TYPE_LRU_HASH &&		 map->map_type != BPF_MAP_TYPE_ARRAY)		goto put_map; 	key_acc_size = prog->aux->max_rdonly_access;	value_acc_size = prog->aux->max_rdwr_access;	key_size = map->key_size;	if (!is_percpu)		value_size = map->value_size;	else		value_size = round_up(map->value_size, 8) * num_possible_cpus(); 	if (key_acc_size > key_size || value_acc_size > value_size) {		err = -EACCES;		goto put_map;	} 	aux->map = map;	return 0; put_map:	bpf_map_put_with_uref(map);	return err;} static void bpf_iter_detach_map(struct bpf_iter_aux_info *aux){	bpf_map_put_with_uref(aux->map);} void bpf_iter_map_show_fdinfo(const struct bpf_iter_aux_info *aux,			      struct seq_file *seq){	seq_printf(seq, "map_id:\t%u\n", aux->map->id);} int bpf_iter_map_fill_link_info(const struct bpf_iter_aux_info *aux,				struct bpf_link_info *info){	info->iter.map.map_id = aux->map->id;	return 0;} DEFINE_BPF_ITER_FUNC(bpf_map_elem, struct bpf_iter_meta *meta,		     struct bpf_map *map, void *key, void *value) static const struct bpf_iter_reg bpf_map_elem_reg_info = {	.target			= "bpf_map_elem",	.attach_target		= bpf_iter_attach_map,	.detach_target		= bpf_iter_detach_map,	.show_fdinfo		= bpf_iter_map_show_fdinfo,	.fill_link_info		= bpf_iter_map_fill_link_info,	.ctx_arg_info_size	= 2,	.ctx_arg_info		= {		{ offsetof(struct bpf_iter__bpf_map_elem, key),		  PTR_TO_RDONLY_BUF_OR_NULL },		{ offsetof(struct bpf_iter__bpf_map_elem, value),		  PTR_TO_RDWR_BUF_OR_NULL },	},}; static int __init bpf_map_iter_init(void){	int ret; 	bpf_map_reg_info.ctx_arg_info[0].btf_id = *btf_bpf_map_id;	ret = bpf_iter_reg_target(&bpf_map_reg_info);	if (ret)		return ret; 	return bpf_iter_reg_target(&bpf_map_elem_reg_info);} late_initcall(bpf_map_iter_init);