// ----------------------------------------------------------------------
// File: EosUdpDumper.cc
// Author: Andreas-Joachim Peters - CERN
// ----------------------------------------------------------------------

/************************************************************************
 * EOS - the CERN Disk Storage System                                   *
 * Copyright (C) 2011 CERN/Switzerland                                  *
 *                                                                      *
 * This program is free software: you can redistribute it and/or modify *
 * it under the terms of the GNU General Public License as published by *
 * the Free Software Foundation, either version 3 of the License, or    *
 * (at your option) any later version.                                  *
 *                                                                      *
 * This program is distributed in the hope that it will be useful,      *
 * but WITHOUT ANY WARRANTY; without even the implied warranty of       *
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the        *
 * GNU General Public License for more details.                         *
 *                                                                      *
 * You should have received a copy of the GNU General Public License    *
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.*
 ************************************************************************/

/*-----------------------------------------------------------------------------*/
/*-----------------------------------------------------------------------------*/
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
/*-----------------------------------------------------------------------------*/

// a UDP server listening by default on port 32.000 dumping UDP packets of max. 64k

int main(int argc, char** argv)
{
  int sockfd, n;
  struct sockaddr_in servaddr, cliaddr;
  socklen_t len;
  char mesg[65536];
  int port = 32000;

  if (argc > 1) {
    if (atoi(argv[1]) && (argc == 2)) {
      port = atoi(argv[1]);
    } else {
      fprintf(stderr, "usage: eos-udp-dumper [port]\n");
      exit(-1);
    }
  }

  fprintf(stdout, "[eos-udp-dumper]: listening on port %d (max_message_size"
          "=64k)\n", port);
  sockfd = socket(AF_INET, SOCK_DGRAM, 0);

  if (sockfd == -1) {
    fprintf(stderr, "error: failed while calling socket\n");
    return 1;
  }

  bzero(&servaddr, sizeof(servaddr));
  servaddr.sin_family = AF_INET;
  servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
  servaddr.sin_port = htons(port);
  bind(sockfd, (struct sockaddr*)&servaddr, sizeof(servaddr));

  for (;;) {
    len = sizeof(cliaddr);
    n = recvfrom(sockfd, mesg, 65536, 0, (struct sockaddr*)&cliaddr, &len);

    if (n == -1) {
      fprintf(stderr, "error: failed while calling recvfrom\n");
      return 1;
    }

    if (sendto(sockfd, mesg, n, 0, (struct sockaddr*)&cliaddr,
               sizeof(cliaddr)) == -1) {
      fprintf(stderr, "error: failed while calling sendto\n");
      return 1;
    }

    printf("-------------------------------------------------------\n");
    mesg[n] = 0;
    printf("%s", mesg);
    printf("-------------------------------------------------------\n");
  }
}