451 lines
11 KiB
C
451 lines
11 KiB
C
/******************************************************************************/
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/* */
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/* Copyright (c) International Business Machines Corp., 2006 */
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/* */
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/* This program is free software; you can redistribute it and/or modify */
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/* it under the terms of the GNU General Public License as published by */
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/* the Free Software Foundation; either version 2 of the License, or */
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/* (at your option) any later version. */
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/* */
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/* This program is distributed in the hope that it will be useful, */
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/* but WITHOUT ANY WARRANTY; without even the implied warranty of */
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/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See */
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/* the GNU General Public License for more details. */
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/* */
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/* You should have received a copy of the GNU General Public License */
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/* along with this program; if not, write to the Free Software */
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/* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */
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/* */
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/******************************************************************************/
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/*
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* File:
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* ns-mcast_receiver.c
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*
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* Description:
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* This is a multicast UDP datagram receiver
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*
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* Author:
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* Mitsuru Chinen <mitch@jp.ibm.com>
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*
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* History:
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* Apr 19 2006 - Created (Mitsuru Chinen)
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*---------------------------------------------------------------------------*/
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/*
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* Header Files
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*/
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#include <netinet/in.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <errno.h>
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#include <netdb.h>
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#include <signal.h>
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#include <time.h>
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#include <unistd.h>
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#include <net/if.h>
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#include <sys/ioctl.h>
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#include <sys/socket.h>
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#include <sys/types.h>
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#include "ns-mcast.h"
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#include "ns-traffic.h"
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/*
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* Structure Definitions
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*/
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struct mcast_rcv_info {
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struct addrinfo *mainfo;
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struct group_req *greq;
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struct group_filter *gsf;
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double timeout;
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};
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/*
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* Gloval variables
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*/
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char *program_name; /* program name */
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struct sigaction handler; /* Behavior for a signal */
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int catch_sighup; /* When catch the SIGHUP, set to non-zero */
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/*
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* Function: usage()
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*
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* Descripton:
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* Print the usage of this program. Then, terminate this program with
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* the specified exit value.
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*
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* Argument:
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* exit_value: exit value
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*
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* Return value:
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* This function does not return.
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*/
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void usage(char *program_name, int exit_value)
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{
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FILE *stream = stdout; /* stream where the usage is output */
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if (exit_value == EXIT_FAILURE)
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stream = stderr;
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fprintf(stream, "%s [OPTION]\n"
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"\t-f num\ttprotocol family\n"
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"\t\t 4 : IPv4\n"
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"\t\t 6 : IPv6\n"
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"\t-I ifname\tname of listening interface\n"
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"\t-m addr\tmulticast address\n"
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"\t-F mode\tfilter mode\n"
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"\t\t include : include mode\n"
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"\t\t exclude : exclude mode\n"
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"\t-s addrs\tcomma separated array of Source Addresses\n"
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"\t-p num\tport number\n"
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"\t-t value\ttimeout [sec]\n"
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"\t-b\t\twork in the background\n"
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"\t-d\t\tdisplay debug informations\n"
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"\t-h\t\tdisplay this usage\n", program_name);
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exit(exit_value);
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}
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/*
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* Function: set_signal_flag()
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*
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* Description:
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* This function sets global variables accordig to signal
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*
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* Argument:
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* type: type of signal
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*
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* Return value:
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* None
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*/
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void set_signal_flag(int type)
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{
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if (debug)
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fprintf(stderr, "Catch signal. type is %d\n", type);
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switch (type) {
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case SIGHUP:
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catch_sighup = 1;
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handler.sa_handler = SIG_IGN;
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if (sigaction(type, &handler, NULL) < 0)
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fatal_error("sigaction()");
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break;
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default:
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fprintf(stderr, "Unexpected signal (%d) is caught\n", type);
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exit(EXIT_FAILURE);
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}
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}
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/*
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* Function: parse_options()
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*
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* Description:
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* This function parse the options
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*
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* Argument:
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* argc: the number of argument
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* argv: arguments
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* info_p: pointer to data of multicast receiver information
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* bg_p: pointer to the flag of working in backgrond
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*
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* Return value:
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* None
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*/
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void
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parse_options(int argc, char *argv[], struct mcast_rcv_info *info_p, int *bg_p)
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{
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int optc; /* option */
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unsigned long opt_ul; /* option value in unsigned long */
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double opt_d; /* option value in double */
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uint32_t ifindex = 0; /* interface index where listening multicast */
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sa_family_t family = AF_UNSPEC; /* protocol family */
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char *maddr; /* multicast address */
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uint32_t fmode = 0; /* filter mode */
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char *saddrs; /* comma separated array of source addresses */
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char *portnum; /* listen port number in character string */
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maddr = NULL;
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saddrs = NULL;
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portnum = NULL;
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while ((optc = getopt(argc, argv, "f:I:m:F:s:p:t:bdh")) != EOF) {
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switch (optc) {
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case 'f':
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if (optarg[0] == '4')
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family = PF_INET; /* IPv4 */
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else if (optarg[0] == '6')
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family = PF_INET6; /* IPv6 */
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else {
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fprintf(stderr,
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"protocol family should be 4 or 6.\n");
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usage(program_name, EXIT_FAILURE);
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}
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break;
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case 'I':
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ifindex = if_nametoindex(optarg);
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if (ifindex == 0) {
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fprintf(stderr,
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"specified interface is incorrect\n");
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usage(program_name, EXIT_FAILURE);
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}
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break;
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case 'm':
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maddr = strdup(optarg);
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if (maddr == NULL)
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fatal_error("strdup()");
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break;
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case 'F':
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if (strncmp(optarg, "exclude", 8) == 0)
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fmode = MCAST_EXCLUDE;
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else if (strncmp(optarg, "include", 8) == 0)
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fmode = MCAST_INCLUDE;
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else {
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fprintf(stderr,
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"specified filter mode is incorrect\n");
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usage(program_name, EXIT_FAILURE);
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}
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break;
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case 's':
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saddrs = strdup(optarg);
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if (saddrs == NULL)
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fatal_error("strdup()");
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break;
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case 'p':
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opt_ul = strtoul(optarg, NULL, 0);
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if (opt_ul < PORTNUMMIN || PORTNUMMAX < opt_ul) {
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fprintf(stderr,
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"The range of port is from %u to %u\n",
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PORTNUMMIN, PORTNUMMAX);
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usage(program_name, EXIT_FAILURE);
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}
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portnum = strdup(optarg);
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break;
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case 't':
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opt_d = strtod(optarg, NULL);
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if (opt_d < 0.0) {
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fprintf(stderr,
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"Timeout should be positive value\n");
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usage(program_name, EXIT_FAILURE);
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}
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info_p->timeout = opt_d;
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break;
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case 'b':
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*bg_p = 1;
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break;
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case 'd':
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debug = 1;
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break;
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case 'h':
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usage(program_name, EXIT_SUCCESS);
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break;
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default:
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usage(program_name, EXIT_FAILURE);
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}
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}
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if (ifindex == 0) {
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fprintf(stderr, "specified interface seems incorrect\n");
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usage(program_name, EXIT_FAILURE);
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}
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if (maddr == NULL) {
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fprintf(stderr, "multicast address is not specified\n");
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usage(program_name, EXIT_FAILURE);
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}
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if (portnum == NULL) {
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fprintf(stderr, "listening port number is not specified\n");
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usage(program_name, EXIT_FAILURE);
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}
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info_p->mainfo = get_maddrinfo(family, maddr, portnum);
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info_p->greq = create_group_info(ifindex, info_p->mainfo);
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if (saddrs) {
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if (fmode != MCAST_EXCLUDE && fmode != MCAST_INCLUDE) {
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fprintf(stderr, "filter mode is wrong\n");
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usage(program_name, EXIT_FAILURE);
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}
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info_p->gsf =
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create_source_filter(ifindex, info_p->mainfo, fmode,
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saddrs);
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}
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free(maddr);
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free(saddrs);
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free(portnum);
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}
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/*
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* Function: create_mcast_socket()
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*
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* Description:
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* This function creates a socket to receive multicast datagrams
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*
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* Argument:
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* info_p: pointer to data of multicast receiver information
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*
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* Return value:
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* file descriptor referencing the socket
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*/
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int create_mcast_socket(struct mcast_rcv_info *info_p)
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{
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int sd; /* socket file descriptor */
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int level; /* protocol levels */
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int on; /* flag for setsockopt */
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switch (info_p->mainfo->ai_family) {
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case PF_INET:
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level = IPPROTO_IP;
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break;
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case PF_INET6:
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level = IPPROTO_IPV6;
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break;
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default:
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level = 0;
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fprintf(stderr, "Unknown protocol level %d\n", level);
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exit(EXIT_FAILURE);
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break;
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}
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/* Create a socket */
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sd = socket(info_p->mainfo->ai_family, info_p->mainfo->ai_socktype,
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info_p->mainfo->ai_protocol);
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if (sd < 0)
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fatal_error("socket()");
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/* Bind to the multicast address */
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if (bind(sd, info_p->mainfo->ai_addr, info_p->mainfo->ai_addrlen) < 0)
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fatal_error("bind()");
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/* Enable to reuse the socket */
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on = 1;
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if (setsockopt(sd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(int)))
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fatal_error("setsockopt(): failed to set reuse the socket");
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/* Join the multicast group */
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if (setsockopt
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(sd, level, MCAST_JOIN_GROUP, info_p->greq,
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sizeof(struct group_req)))
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fatal_error("setsockopt(): failed to join the multicast group");
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/* Apply the source filter */
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if (info_p->gsf) {
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if (setsockopt
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(sd, level, MCAST_MSFILTER, info_p->gsf,
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GROUP_FILTER_SIZE(info_p->gsf->gf_numsrc)))
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fatal_error
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("setsockopt(): failed to apply the source filter");
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}
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return sd;
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}
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/*
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* Function: receive_mcast()
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*
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* Description:
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* This function receives multicast datagarms
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*
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* Argument:
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* info_p: pointer to data of multicast receiver information
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*
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* Return value:
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* None
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*/
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void receive_mcast(struct mcast_rcv_info *info_p)
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{
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int sd;
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char *msgbuf; /* Pointer to the message */
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size_t msgbuf_size; /* size of msgbuf */
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ssize_t msglen; /* the length of message */
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socklen_t optlen; /* size of the result parameter */
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double start_time; /* start time when receiving datagrams */
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/* Create a socket */
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sd = create_mcast_socket(info_p);
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/* Allocate a buffer to store the message */
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optlen = sizeof(msgbuf_size);
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if (getsockopt(sd, SOL_SOCKET, SO_RCVBUF, &msgbuf_size, &optlen) < 0) {
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perror("getsockopt()");
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close(sd);
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exit(EXIT_FAILURE);
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}
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msgbuf = malloc(msgbuf_size + 1);
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if (msgbuf == NULL) {
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fprintf(stderr, "malloc() is failed.\n");
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close(sd);
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exit(EXIT_FAILURE);
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}
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/* Set singal hander for SIGHUP */
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handler.sa_handler = set_signal_flag;
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handler.sa_flags = 0;
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if (sigfillset(&handler.sa_mask) < 0)
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fatal_error("sigfillset()");
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if (sigaction(SIGHUP, &handler, NULL) < 0)
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fatal_error("sigfillset()");
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/* Receive the message */
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start_time = time(NULL);
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for (;;) {
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struct sockaddr_storage addr;
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socklen_t addrlen;
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addrlen = sizeof(addr);
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msglen = recvfrom(sd, msgbuf, msgbuf_size, MSG_DONTWAIT,
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(struct sockaddr *)&addr, &addrlen);
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if (msglen < 0) {
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if (errno != EAGAIN)
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fatal_error("recvfrom()");
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} else if (debug)
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fprintf(stderr, "received %zd byte message\n", msglen);
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if (info_p->timeout)
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if (info_p->timeout < difftime(time(NULL), start_time))
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break;
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if (catch_sighup) /* catch SIGHUP */
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break;
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}
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close(sd);
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}
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/*
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*
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* Function: main()
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*
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*/
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int main(int argc, char *argv[])
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{
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struct mcast_rcv_info mcast_rcv;
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int background = 0;
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debug = 0;
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program_name = strdup(argv[0]);
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memset(&mcast_rcv, '\0', sizeof(struct mcast_rcv_info));
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parse_options(argc, argv, &mcast_rcv, &background);
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if (background) /* Work in the background */
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if (daemon(0, 0) < 0)
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fatal_error("daemon()");
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receive_mcast(&mcast_rcv);
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exit(EXIT_SUCCESS);
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}
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