/*
 * Copyright 2010, Atis Elsts, the.kfx@gmail.com
 * Distributed under the terms of the MIT license.
 */


#include <unistd.h>
#include <memory.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <arpa/inet.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>


const unsigned short TEST_PROTOCOL = 89;


void
recvLoop(int fd)
{
        for (;;) {
                char buffer[1000];
                sockaddr_storage address;
                socklen_t socklen = sizeof(address);
                memset(&address, 0, socklen);

                int status = recvfrom(fd, buffer, sizeof(buffer) - 1, 0,
                        (sockaddr *) &address, &socklen);
                if (status < 0) {
                        perror("recvfrom");
                        exit(-1);
                }
                if (status == 0) {
                        printf("received EOF!\n");
                        break;
                } else {
                        char *p = buffer;
                        if (address.ss_family == AF_INET && status >= sizeof(struct ip))
                                p += sizeof(struct ip);
                        buffer[status] = 0;
                        printf("received %d bytes: \"%s\"\n", status, p);
                }
        }
}


int
main(int argc, char *argv[])
{
        int socketFamily = AF_INET;

        if (argc > 1) {
                if (!strcmp(argv[1], "-4"))
                        socketFamily = AF_INET;
                else if (!strcmp(argv[1], "-6"))
                        socketFamily = AF_INET6;
        }

        int fd = socket(socketFamily, SOCK_RAW, TEST_PROTOCOL);
        if (fd < 0) {
                perror("socket");
                return -1;
        }

        sockaddr_storage localAddress;
        memset(&localAddress, 0, sizeof(localAddress));
        if (socketFamily == AF_INET) {
                sockaddr_in *sa = (sockaddr_in *) &localAddress;
                sa->sin_family = AF_INET;
        } else {
                sockaddr_in6 *sa = (sockaddr_in6 *) &localAddress;
                sa->sin6_family = AF_INET6;
        }

        // TODO: is this even necessary?
        if (bind(fd, (sockaddr *)&localAddress, socketFamily == AF_INET ?
                        sizeof(sockaddr_in) : sizeof(sockaddr_in6)) < 0) {
                perror("bind");
                return -1;
        }

        for (;;)
                recvLoop(fd);
}