// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2020 Cloudflare

#include <errno.h>
#include <stdbool.h>
#include <linux/bpf.h>

#include <bpf/bpf_helpers.h>

struct {
        __uint(type, BPF_MAP_TYPE_SOCKMAP);
        __uint(max_entries, 2);
        __type(key, __u32);
        __type(value, __u64);
} sock_map SEC(".maps");

struct {
        __uint(type, BPF_MAP_TYPE_SOCKMAP);
        __uint(max_entries, 2);
        __type(key, __u32);
        __type(value, __u64);
} nop_map SEC(".maps");

struct {
        __uint(type, BPF_MAP_TYPE_SOCKHASH);
        __uint(max_entries, 2);
        __type(key, __u32);
        __type(value, __u64);
} sock_hash SEC(".maps");

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

struct {
        __uint(type, BPF_MAP_TYPE_ARRAY);
        __uint(max_entries, 1);
        __type(key, int);
        __type(value, int);
} parser_map SEC(".maps");

bool test_sockmap = false; /* toggled by user-space */
bool test_ingress = false; /* toggled by user-space */

SEC("sk_skb/stream_parser")
int prog_stream_parser(struct __sk_buff *skb)
{
        int *value;
        __u32 key = 0;

        value = bpf_map_lookup_elem(&parser_map, &key);
        if (value && *value)
                return *value;

        return skb->len;
}

SEC("sk_skb/stream_verdict")
int prog_stream_verdict(struct __sk_buff *skb)
{
        unsigned int *count;
        __u32 zero = 0;
        int verdict;

        if (test_sockmap)
                verdict = bpf_sk_redirect_map(skb, &sock_map, zero, 0);
        else
                verdict = bpf_sk_redirect_hash(skb, &sock_hash, &zero, 0);

        count = bpf_map_lookup_elem(&verdict_map, &verdict);
        if (count)
                (*count)++;

        return verdict;
}

SEC("sk_skb")
int prog_skb_verdict(struct __sk_buff *skb)
{
        unsigned int *count;
        __u32 zero = 0;
        int verdict;

        if (test_sockmap)
                verdict = bpf_sk_redirect_map(skb, &sock_map, zero,
                                              test_ingress ? BPF_F_INGRESS : 0);
        else
                verdict = bpf_sk_redirect_hash(skb, &sock_hash, &zero,
                                               test_ingress ? BPF_F_INGRESS : 0);

        count = bpf_map_lookup_elem(&verdict_map, &verdict);
        if (count)
                (*count)++;

        return verdict;
}

SEC("sk_msg")
int prog_msg_verdict(struct sk_msg_md *msg)
{
        unsigned int *count;
        __u32 zero = 0;
        int verdict;

        if (test_sockmap)
                verdict = bpf_msg_redirect_map(msg, &sock_map, zero, 0);
        else
                verdict = bpf_msg_redirect_hash(msg, &sock_hash, &zero, 0);

        count = bpf_map_lookup_elem(&verdict_map, &verdict);
        if (count)
                (*count)++;

        return verdict;
}

SEC("sk_reuseport")
int prog_reuseport(struct sk_reuseport_md *reuse)
{
        unsigned int *count;
        int err, verdict;
        __u32 zero = 0;

        if (test_sockmap)
                err = bpf_sk_select_reuseport(reuse, &sock_map, &zero, 0);
        else
                err = bpf_sk_select_reuseport(reuse, &sock_hash, &zero, 0);
        verdict = err ? SK_DROP : SK_PASS;

        count = bpf_map_lookup_elem(&verdict_map, &verdict);
        if (count)
                (*count)++;

        return verdict;
}

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