// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */

#include <vmlinux.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include <bpf/bpf_core_read.h>
#include "../bpf_experimental.h"
#include "bpf_misc.h"

struct node_data {
        long key;
        long data;
        struct bpf_rb_node node;
};

struct map_value {
        struct node_data __kptr *node;
};

struct node_data2 {
        long key[4];
};

/* This is necessary so that LLVM generates BTF for node_data struct
 * If it's not included, a fwd reference for node_data will be generated but
 * no struct. Example BTF of "node" field in map_value when not included:
 *
 * [10] PTR '(anon)' type_id=35
 * [34] FWD 'node_data' fwd_kind=struct
 * [35] TYPE_TAG 'kptr_ref' type_id=34
 */
struct node_data *just_here_because_btf_bug;

struct {
        __uint(type, BPF_MAP_TYPE_ARRAY);
        __type(key, int);
        __type(value, struct map_value);
        __uint(max_entries, 2);
} some_nodes SEC(".maps");

SEC("tc")
__failure __msg("invalid kptr access, R2 type=ptr_node_data2 expected=ptr_node_data")
long stash_rb_nodes(void *ctx)
{
        struct map_value *mapval;
        struct node_data2 *res;
        int idx = 0;

        mapval = bpf_map_lookup_elem(&some_nodes, &idx);
        if (!mapval)
                return 1;

        res = bpf_obj_new(typeof(*res));
        if (!res)
                return 1;
        res->key[0] = 40;

        res = bpf_kptr_xchg(&mapval->node, res);
        if (res)
                bpf_obj_drop(res);
        return 0;
}

SEC("tc")
__failure __msg("R1 must have zero offset when passed to release func")
long drop_rb_node_off(void *ctx)
{
        struct map_value *mapval;
        struct node_data *res;
        int idx = 0;

        mapval = bpf_map_lookup_elem(&some_nodes, &idx);
        if (!mapval)
                return 1;

        res = bpf_obj_new(typeof(*res));
        if (!res)
                return 1;
        /* Try releasing with graph node offset */
        bpf_obj_drop(&res->node);
        return 0;
}

char _license[] SEC("license") = "GPL";