// SPDX-License-Identifier: GPL-2.0
#include <stdio.h>
#include <assert.h>
#include <bpf/bpf.h>
#include <bpf/libbpf.h>
#include "sock_example.h"
#include <unistd.h>
#include <arpa/inet.h>

struct flow_key_record {
        __be32 src;
        __be32 dst;
        union {
                __be32 ports;
                __be16 port16[2];
        };
        __u32 ip_proto;
};

struct pair {
        __u64 packets;
        __u64 bytes;
};

int main(int argc, char **argv)
{
        int i, sock, fd, main_prog_fd, hash_map_fd;
        struct bpf_program *prog;
        struct bpf_object *obj;
        char filename[256];
        FILE *f;

        snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);

        obj = bpf_object__open_file(filename, NULL);
        if (libbpf_get_error(obj)) {
                fprintf(stderr, "ERROR: opening BPF object file failed\n");
                return 0;
        }

        /* load BPF program */
        if (bpf_object__load(obj)) {
                fprintf(stderr, "ERROR: loading BPF object file failed\n");
                goto cleanup;
        }

        hash_map_fd = bpf_object__find_map_fd_by_name(obj, "hash_map");
        if (hash_map_fd < 0) {
                fprintf(stderr, "ERROR: finding a map in obj file failed\n");
                goto cleanup;
        }

        /* find BPF main program */
        main_prog_fd = 0;
        bpf_object__for_each_program(prog, obj) {
                fd = bpf_program__fd(prog);

                if (!strcmp(bpf_program__name(prog), "main_prog"))
                        main_prog_fd = fd;
        }

        if (main_prog_fd == 0) {
                fprintf(stderr, "ERROR: can't find main_prog\n");
                goto cleanup;
        }

        sock = open_raw_sock("lo");

        /* attach BPF program to socket */
        assert(setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, &main_prog_fd,
                          sizeof(__u32)) == 0);

        if (argc > 1)
                f = popen("ping -4 -c5 localhost", "r");
        else
                f = popen("netperf -l 4 localhost", "r");
        (void) f;

        for (i = 0; i < 5; i++) {
                struct flow_key_record key = {}, next_key;
                struct pair value;

                sleep(1);
                printf("IP     src.port -> dst.port               bytes      packets\n");
                while (bpf_map_get_next_key(hash_map_fd, &key, &next_key) == 0) {
                        bpf_map_lookup_elem(hash_map_fd, &next_key, &value);
                        printf("%s.%05d -> %s.%05d %12lld %12lld\n",
                               inet_ntoa((struct in_addr){htonl(next_key.src)}),
                               next_key.port16[0],
                               inet_ntoa((struct in_addr){htonl(next_key.dst)}),
                               next_key.port16[1],
                               value.bytes, value.packets);
                        key = next_key;
                }
        }

cleanup:
        bpf_object__close(obj);
        return 0;
}