// SPDX-License-Identifier: GPL-2.0-only/* Copyright (c) 2022 Red Hat, Inc. */#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_link_info {	u32 link_id;}; static void *bpf_link_seq_start(struct seq_file *seq, loff_t *pos){	struct bpf_iter_seq_link_info *info = seq->private;	struct bpf_link *link; 	link = bpf_link_get_curr_or_next(&info->link_id);	if (!link)		return NULL; 	if (*pos == 0)		++*pos;	return link;} static void *bpf_link_seq_next(struct seq_file *seq, void *v, loff_t *pos){	struct bpf_iter_seq_link_info *info = seq->private; 	++*pos;	++info->link_id;	bpf_link_put((struct bpf_link *)v);	return bpf_link_get_curr_or_next(&info->link_id);} struct bpf_iter__bpf_link {	__bpf_md_ptr(struct bpf_iter_meta *, meta);	__bpf_md_ptr(struct bpf_link *, link);}; DEFINE_BPF_ITER_FUNC(bpf_link, struct bpf_iter_meta *meta, struct bpf_link *link) static int __bpf_link_seq_show(struct seq_file *seq, void *v, bool in_stop){	struct bpf_iter__bpf_link ctx;	struct bpf_iter_meta meta;	struct bpf_prog *prog;	int ret = 0; 	ctx.meta = &meta;	ctx.link = 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_link_seq_show(struct seq_file *seq, void *v){	return __bpf_link_seq_show(seq, v, false);} static void bpf_link_seq_stop(struct seq_file *seq, void *v){	if (!v)		(void)__bpf_link_seq_show(seq, v, true);	else		bpf_link_put((struct bpf_link *)v);} static const struct seq_operations bpf_link_seq_ops = {	.start	= bpf_link_seq_start,	.next	= bpf_link_seq_next,	.stop	= bpf_link_seq_stop,	.show	= bpf_link_seq_show,}; BTF_ID_LIST_SINGLE(btf_bpf_link_id, struct, bpf_link) static const struct bpf_iter_seq_info bpf_link_seq_info = {	.seq_ops		= &bpf_link_seq_ops,	.init_seq_private	= NULL,	.fini_seq_private	= NULL,	.seq_priv_size		= sizeof(struct bpf_iter_seq_link_info),}; static struct bpf_iter_reg bpf_link_reg_info = {	.target			= "bpf_link",	.ctx_arg_info_size	= 1,	.ctx_arg_info		= {		{ offsetof(struct bpf_iter__bpf_link, link),		  PTR_TO_BTF_ID_OR_NULL },	},	.seq_info		= &bpf_link_seq_info,}; static int __init bpf_link_iter_init(void){	bpf_link_reg_info.ctx_arg_info[0].btf_id = *btf_bpf_link_id;	return bpf_iter_reg_target(&bpf_link_reg_info);} late_initcall(bpf_link_iter_init);