162306a36Sopenharmony_ci// SPDX-License-Identifier: GPL-2.0
262306a36Sopenharmony_ci/* Copyright (c) 2022 Google */
362306a36Sopenharmony_ci
462306a36Sopenharmony_ci#include "bpf_iter.h"
562306a36Sopenharmony_ci#include <bpf/bpf_helpers.h>
662306a36Sopenharmony_ci#include <bpf/bpf_tracing.h>
762306a36Sopenharmony_ci
862306a36Sopenharmony_cichar _license[] SEC("license") = "GPL";
962306a36Sopenharmony_ciint terminate_early = 0;
1062306a36Sopenharmony_ciu64 terminal_cgroup = 0;
1162306a36Sopenharmony_ci
1262306a36Sopenharmony_cistatic inline u64 cgroup_id(struct cgroup *cgrp)
1362306a36Sopenharmony_ci{
1462306a36Sopenharmony_ci	return cgrp->kn->id;
1562306a36Sopenharmony_ci}
1662306a36Sopenharmony_ci
1762306a36Sopenharmony_ciSEC("iter/cgroup")
1862306a36Sopenharmony_ciint cgroup_id_printer(struct bpf_iter__cgroup *ctx)
1962306a36Sopenharmony_ci{
2062306a36Sopenharmony_ci	struct seq_file *seq = ctx->meta->seq;
2162306a36Sopenharmony_ci	struct cgroup *cgrp = ctx->cgroup;
2262306a36Sopenharmony_ci
2362306a36Sopenharmony_ci	/* epilogue */
2462306a36Sopenharmony_ci	if (cgrp == NULL) {
2562306a36Sopenharmony_ci		BPF_SEQ_PRINTF(seq, "epilogue\n");
2662306a36Sopenharmony_ci		return 0;
2762306a36Sopenharmony_ci	}
2862306a36Sopenharmony_ci
2962306a36Sopenharmony_ci	/* prologue */
3062306a36Sopenharmony_ci	if (ctx->meta->seq_num == 0)
3162306a36Sopenharmony_ci		BPF_SEQ_PRINTF(seq, "prologue\n");
3262306a36Sopenharmony_ci
3362306a36Sopenharmony_ci	BPF_SEQ_PRINTF(seq, "%8llu\n", cgroup_id(cgrp));
3462306a36Sopenharmony_ci
3562306a36Sopenharmony_ci	if (terminal_cgroup == cgroup_id(cgrp))
3662306a36Sopenharmony_ci		return 1;
3762306a36Sopenharmony_ci
3862306a36Sopenharmony_ci	return terminate_early ? 1 : 0;
3962306a36Sopenharmony_ci}
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