// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB

/*
 * ibumad BPF sample user side
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 *
 * Copyright(c) 2018 Ira Weiny, Intel Corporation
 */

#include <linux/bpf.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <limits.h>

#include <getopt.h>
#include <net/if.h>

#include <bpf/bpf.h>
#include "bpf_util.h"
#include <bpf/libbpf.h>

static struct bpf_link *tp_links[3];
static struct bpf_object *obj;
static int map_fd[2];
static int tp_cnt;

static void dump_counts(int fd)
{
        __u32 key;
        __u64 value;

        for (key = 0; key < 256; key++) {
                if (bpf_map_lookup_elem(fd, &key, &value)) {
                        printf("failed to read key %u\n", key);
                        continue;
                }
                if (value)
                        printf("0x%02x : %llu\n", key, value);
        }
}

static void dump_all_counts(void)
{
        printf("Read 'Class : count'\n");
        dump_counts(map_fd[0]);
        printf("Write 'Class : count'\n");
        dump_counts(map_fd[1]);
}

static void dump_exit(int sig)
{
        dump_all_counts();
        /* Detach tracepoints */
        while (tp_cnt)
                bpf_link__destroy(tp_links[--tp_cnt]);

        bpf_object__close(obj);
        exit(0);
}

static const struct option long_options[] = {
        {"help",      no_argument,       NULL, 'h'},
        {"delay",     required_argument, NULL, 'd'},
};

static void usage(char *cmd)
{
        printf("eBPF test program to count packets from various IP addresses\n"
                "Usage: %s <options>\n"
                "       --help,   -h  this menu\n"
                "       --delay,  -d  <delay>  wait <delay> sec between prints [1 - 1000000]\n"
                , cmd
                );
}

int main(int argc, char **argv)
{
        struct bpf_program *prog;
        unsigned long delay = 5;
        char filename[256];
        int longindex = 0;
        int opt, err = -1;

        while ((opt = getopt_long(argc, argv, "hd:rSw",
                                  long_options, &longindex)) != -1) {
                switch (opt) {
                case 'd':
                        delay = strtoul(optarg, NULL, 0);
                        if (delay == ULONG_MAX || delay < 0 ||
                            delay > 1000000) {
                                fprintf(stderr, "ERROR: invalid delay : %s\n",
                                        optarg);
                                usage(argv[0]);
                                return 1;
                        }
                        break;
                default:
                case 'h':
                        usage(argv[0]);
                        return 1;
                }
        }

        /* Do one final dump when exiting */
        signal(SIGINT, dump_exit);
        signal(SIGTERM, dump_exit);

        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 err;
        }

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

        map_fd[0] = bpf_object__find_map_fd_by_name(obj, "read_count");
        map_fd[1] = bpf_object__find_map_fd_by_name(obj, "write_count");
        if (map_fd[0] < 0 || map_fd[1] < 0) {
                fprintf(stderr, "ERROR: finding a map in obj file failed\n");
                goto cleanup;
        }

        bpf_object__for_each_program(prog, obj) {
                tp_links[tp_cnt] = bpf_program__attach(prog);
                if (libbpf_get_error(tp_links[tp_cnt])) {
                        fprintf(stderr, "ERROR: bpf_program__attach failed\n");
                        tp_links[tp_cnt] = NULL;
                        goto cleanup;
                }
                tp_cnt++;
        }

        while (1) {
                sleep(delay);
                dump_all_counts();
        }
        err = 0;

cleanup:
        /* Detach tracepoints */
        while (tp_cnt)
                bpf_link__destroy(tp_links[--tp_cnt]);

        bpf_object__close(obj);
        return err;
}