#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif /* _GNU_SOURCE */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <getopt.h>
#include <string.h>
#include <errno.h>
#include <signal.h>
#include <net/if.h>
#include <sys/epoll.h>
#include <pfring.h>
#include <pfring_zc.h>
#include <sched.h>

int stop = 0;

void handler(int sig) {
    stop = 1;
}//end handler

void stick_cpu_core(int cpu) {
    cpu_set_t cpuset;

    CPU_ZERO(&cpuset);
    CPU_SET(cpu, &cpuset);

    sched_setaffinity(0, sizeof(cpu_set_t), &cpuset);
}//end stick_cpu_core

pfring *open_ring(const char *dev) {
    pfring *r;

    printf("open %s\n", dev);
    r = pfring_open(dev, 1536, PF_RING_PROMISC);
    if(!r) {
        perror("pfring_open()");
        exit(1);
    }//end if

    pfring_enable_ring(r);

    return r;
}//end open_ring

static void epoll_ctl_add(int epfd, int fd, uint32_t events) {
    struct epoll_event ev;

    ev.events = events;
    ev.data.fd = fd;
    if(epoll_ctl(epfd, EPOLL_CTL_ADD, fd, &ev) == -1) {
        perror("epoll_ctl()");
        exit(1);
    }//end if
}//end epoll_ctl_add

int main(int argc, char *argv[]) {

    int core = 8;

    if(argc == 2) {
        core = atoi(argv[1]);
    }//end if

    signal(SIGINT, handler);

    for(int i = 0 ; i < core ;i  ) {

        if(fork() == 0) {
            stick_cpu_core(i);

            char dev[64];
            snprintf(dev, sizeof(dev), "zc:ens2f0@%d", i);
            pfring *ens2f0 = open_ring(dev);
            snprintf(dev, sizeof(dev), "zc:ens2f1@%d", i);
            pfring *ens2f1 = open_ring(dev);

            int epfd = epoll_create1(1);
            int ens2f0_fd, ens2f1_fd;
            ens2f0_fd = pfring_get_selectable_fd(ens2f0);
            ens2f1_fd = pfring_get_selectable_fd(ens2f1);

            epoll_ctl_add(epfd, ens2f0_fd, EPOLLIN);
            epoll_ctl_add(epfd, ens2f1_fd, EPOLLIN);

            struct epoll_event events[2];

            while(!stop) {
                int nfds = epoll_wait(epfd, events, 2, 1000);
                if(nfds < 0) {
                    perror("epoll_wait()");
                    break;
                } else if(nfds == 0) {
                    continue;
                }//end if

                for(int i = 0 ; i < nfds ; i  ) {
                    pfring *r, *s;
                    if(events[i].data.fd == ens2f0_fd) {
                        r = ens2f0;
                        s = ens2f1;
                    } else {
                        r = ens2f1;
                        s = ens2f0;
                    }//end else

                    u_char *buf;
                    struct pfring_pkthdr hdr;
                    errno = 0;
                    hdr.caplen = 0;
                    int ret = pfring_recv(r, &buf, 0, &hdr, 0);
                    if(ret < 0 && errno != 0) {
                        perror("pfring_recv()");
                        continue;
                    }//end if

                    errno = 0;
                    ret = pfring_send(s, (char *)buf, hdr.caplen, 1);
                    if(ret < 0 && errno != 0) {
                        perror("pfring_send()");
                    }//end if
                }//end for
            }//end while

            pfring_close(ens2f0);
            pfring_close(ens2f1);

            exit(0);
        }//end if
    }//end for

    while(!stop) {
        sleep(1);
    }//end while
    sleep(3);

    return 0;
}//end main