mihalyr/0MulticastTesting.md

## 0MulticastTesting.md

      
    Raw
  

              0MulticastTesting.md
            
          
    IPv4 and IPv6 multicast testing script.
Based on Multicast: From Theory to Practice in Linux Journal
Run on two separate machines with the same group/port as arguments to test multicast.
On Fedora if multicast is not enabled in the firewall this rule might help:
sudo firewall-cmd --direct --add-rule ipv4 filter INPUT 0 -s 192.168.0.0/24 -m addrtype --dst-type MULTICAST -j ACCEPT
sudo firewall-cmd --direct --add-rule ipv6 filter INPUT 0 -s fe80::/64 -m addrtype --dst-type MULTICAST -j ACCEPT

Usage:
Usage: ./mcast_test mcast_group port [ttl]

IPv4 example:
Machine 1 (eli):
./mcast_test 230.0.0.1 37652
eli: Received message from 192.168.0.201.
	Hi, I'm raspi. Merry Christmas!	(TTL==1)
eli: Received message from 192.168.0.201.
	Hi, I'm raspi. Merry Christmas!	(TTL==1)

Machine 2 (raspi):
./mcast_test 230.0.0.1 37652
raspi: Received message from 192.168.0.193.
	Hi, I'm eli. Merry Christmas!	(TTL==1)
raspi: Received message from 192.168.0.193.
	Hi, I'm eli. Merry Christmas!	(TTL==1)

IPv6 example:
Machine 1 (eli):
./mcast6_test ff05::1 33333
eli: Received message from fe80::xxxx:xxxx:xxxx:c920.
	Hi, I'm raspi. Merry Christmas!	(TTL==1)
eli: Received message from fe80::xxxx:xxxx:xxxx:c920.
	Hi, I'm raspi. Merry Christmas!	(TTL==1)

Machine 2 (raspi):
./mcast6_test ff05::1 33333
raspi: Received message from fe80::xxxx:xxxx:xxxx:6eed.
	Hi, I'm eli. Merry Christmas!	(TTL==1)
raspi: Received message from fe80::xxxx:xxxx:xxxx:6eed.
	Hi, I'm eli. Merry Christmas!	(TTL==1)


## Makefile
.SUFFIXES:
.SUFFIXES: .c
.PHONY: all clean

SHELL = /bin/sh
TARGETS = mcast_test mcast6_test

all: $(TARGETS)

clean:
	rm -f $(TARGETS)

## mcast6_test.c
/*
 * IPv6 Multicast testing utility.
 * Adapted from the IPv4 example in https://www.linuxjournal.com/article/3041
 *
 * Run on two separate machines with the same group/port as arguments to test multicast.
 */
/*
 * This is free software released under the GPL license.
 * See the GNU GPL for details.
 *
 * (c) Juan-Mariano de Goyeneche. 1998, 1999.
 * Modifications: (c) Robert Mihaly. 2020.
 * 2020-01-29: Modified original IPv4 code to use IPv6
 *
 */
#include <stdio.h>   /* printf(), snprintf() */
#include <stdlib.h>      /* strtol(), exit() */
#include <sys/types.h>
#include <sys/socket.h>  /* socket(), setsockopt(), bind(), recvfrom(), sendto() */
#include <errno.h>       /* perror() */
#include <netinet/in.h>  /* IPPROTO_IP, sockaddr_in, htons(), htonl() */
#include <arpa/inet.h>   /* inet_addr() */
#include <unistd.h>      /* fork(), sleep() */
#include <sys/utsname.h> /* uname() */
#include <string.h>      /* memset() */

#define MAXLEN 1024
#define DELAY 2
#define TTL 1

int main(int argc, char* argv[])
{
   u_int no = 0;
   u_int yes = 1;    /* Used with SO_REUSEADDR. In Linux both u_int */
                     /* and u_char are valid. */
   int send_s, recv_s;  /* Sockets for sending and receiving. */
   int ttl;
   struct sockaddr_in6 mcast_group;
   struct ipv6_mreq mreq;
   struct utsname name;
   char buf6[INET6_ADDRSTRLEN];

   if ((argc<3) || (argc>4)) {
       fprintf(stderr, "Usage: %s mcast_group port [ttl]\n", argv[0]);
       exit(1);
   }

   memset(&mcast_group, 0, sizeof(mcast_group));
   mcast_group.sin6_family = AF_INET6;
   mcast_group.sin6_port = htons((unsigned short int)strtol(argv[2], NULL, 0));
   inet_pton(AF_INET6, argv[1], &mcast_group.sin6_addr);

   if ((send_s=socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
       perror ("send socket");
       exit(1);
   }

   /* If ttl supplied, set it */
   if (argc == 4) {
       ttl = strtol(argv[3], NULL, 0);
   } else {
       ttl = TTL;
   }
   printf("ttl = %d\n", ttl);

   if (setsockopt(send_s, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0) {
       perror ("ttl setsockopt");
       exit(1);
   }

   /* Disable Loop-back */
   if (setsockopt(send_s, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &no, sizeof(no)) < 0) {
       perror ("loop setsockopt");
       exit(1);
   }

   if ((recv_s=socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
       perror ("recv socket");
       exit(1);
   }

   if (setsockopt(recv_s, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) {
       perror("reuseaddr setsockopt");
       exit(1);
   }

   if (bind(recv_s, (struct sockaddr*)&mcast_group,sizeof(mcast_group)) < 0){
       perror ("bind");
       exit(1);
   }

   /* Tell the kernel we want to join that multicast group. */
   mreq.ipv6mr_multiaddr = mcast_group.sin6_addr;
   mreq.ipv6mr_interface = INADDR_ANY;

   if (setsockopt(recv_s, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
       perror ("add_membership setsockopt");
       exit(1);
   }

   if (uname(&name) < 0) {
       perror ("uname");
       exit(1);
   }

   switch (fork()) {
     case -1: /* Error fork()ing */
       perror("fork");
       exit(1);
     case 0: {  /* Child -> receive. */
       int n;
       int len;
       struct sockaddr_in6 from;
       char message [MAXLEN+1];

       for (;;) {
         len=sizeof(from);
         if ((n=recvfrom(recv_s, message, MAXLEN, 0, (struct sockaddr*)&from, &len)) < 0) {
              perror ("recv");
              exit(1);
            }
            inet_ntop(AF_INET6, &from.sin6_addr, buf6, sizeof(buf6));
            message[n] = 0; /* null-terminate string */
            printf("%s: Received message from %s.\n", name.nodename, buf6);
            printf("\t%s", message);
         }
         /* Not reached. */
       }
     default: { /* Parent -> send. */
       char message [MAXLEN];
       snprintf (message, sizeof(message), "Hi, I'm %s. "
            "Merry Christmas!\t(TTL==%d)\n", name.nodename, ttl);
       for (;;) {
         if (sendto(send_s, message, strlen(message), 0, (struct sockaddr*)&mcast_group, sizeof(mcast_group)) < strlen(message)) {
            perror("sendto");
            exit(1);
         }
         sleep(DELAY);
       }
    /* Not reached. */
    }
  }
  /* Not really reached. */
}

## mcast_test.c
/*
 * IPv4 Multicast testing utility.
 * Source: Multicast: From Theory to Practice in Linux Journal
 *         https://www.linuxjournal.com/article/3041
 *
 * Run on two separate machines with the same group/port as arguments to test multicast.
 */
/*
 * This is free software released under the GPL license.
 * See the GNU GPL for details.
 *
 * (c) Juan-Mariano de Goyeneche. 1998, 1999.
 *
 */

#include <stdio.h>   /* printf(), snprintf() */
#include <stdlib.h>      /* strtol(), exit() */
#include <sys/types.h>
#include <sys/socket.h>  /* socket(), setsockopt(), bind(), recvfrom(), sendto() */
#include <errno.h>       /* perror() */
#include <netinet/in.h>  /* IPPROTO_IP, sockaddr_in, htons(), htonl() */
#include <arpa/inet.h>   /* inet_addr() */
#include <unistd.h>      /* fork(), sleep() */
#include <sys/utsname.h> /* uname() */
#include <string.h>      /* memset() */

#define MAXLEN 1024
#define DELAY 2
#define TTL 1

int main(int argc, char* argv[])
{
   u_char no = 0;
   u_int yes = 1;    /* Used with SO_REUSEADDR. In Linux both u_int */
                     /* and u_char are valid. */
   int send_s, recv_s;  /* Sockets for sending and receiving. */
   u_char ttl;
   struct sockaddr_in mcast_group;
   struct ip_mreq mreq;
   struct utsname name;

   if ((argc<3) || (argc>4)) {
       fprintf(stderr, "Usage: %s mcast_group port [ttl]\n", argv[0]);
       exit(1);
   }

   memset(&mcast_group, 0, sizeof(mcast_group));
   mcast_group.sin_family = AF_INET;
   mcast_group.sin_port = htons((unsigned short int)strtol(argv[2], NULL, 0));
   mcast_group.sin_addr.s_addr = inet_addr(argv[1]);

   if ((send_s=socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
       perror ("send socket");
       exit(1);
   }

   /* If ttl supplied, set it */
   if (argc == 4) {
       ttl = strtol(argv[3], NULL, 0);
   } else {
       ttl = TTL;
   }

   if (setsockopt(send_s, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0) {
       perror ("ttl setsockopt");
       exit(1);
   }

   /* Disable Loop-back */
   if (setsockopt(send_s, IPPROTO_IP, IP_MULTICAST_LOOP, &no, sizeof(no)) < 0) {
       perror ("loop setsockopt");
       exit(1);
   }

   if ((recv_s=socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
       perror ("recv socket");
       exit(1);
   }

   if (setsockopt(recv_s, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) {
       perror("reuseaddr setsockopt");
       exit(1);
   }

   if (bind(recv_s, (struct sockaddr*)&mcast_group,sizeof(mcast_group)) < 0){
       perror ("bind");
       exit(1);
   }

   /* Tell the kernel we want to join that multicast group. */
   mreq.imr_multiaddr = mcast_group.sin_addr;
   mreq.imr_interface.s_addr = htonl(INADDR_ANY);

   if (setsockopt(recv_s, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
       perror ("add_membership setsockopt");
       exit(1);
   }

   if (uname(&name) < 0) {
       perror ("uname");
       exit(1);
   }

   switch (fork()) {
     case -1: /* Error fork()ing */
       perror("fork");
       exit(1);
     case 0: {  /* Child -> receive. */
       int n;
       int len;
       struct sockaddr_in from;
       char message [MAXLEN+1];

       for (;;) {
         len=sizeof(from);
         if ((n=recvfrom(recv_s, message, MAXLEN, 0, (struct sockaddr*)&from, &len)) < 0) {
              perror ("recv");
              exit(1);
            }
            message[n] = 0; /* null-terminate string */
            printf("%s: Received message from %s.\n", name.nodename, inet_ntoa(from.sin_addr));
            printf("\t%s", message);
         }
         /* Not reached. */
       }
     default: { /* Parent -> send. */
       char message [MAXLEN];
       snprintf (message, sizeof(message), "Hi, I'm %s. "
            "Merry Christmas!\t(TTL==%d)\n", name.nodename, ttl);
       for (;;) {
         if (sendto(send_s, message, strlen(message), 0, (struct sockaddr*)&mcast_group, sizeof(mcast_group)) < strlen(message)) {
            perror("sendto");
            exit(1);
         }
         sleep(DELAY);
       }
    /* Not reached. */
    }
  }
  /* Not really reached. */
}
	.SUFFIXES:
	.SUFFIXES: .c
	.PHONY: all clean

	SHELL = /bin/sh
	TARGETS = mcast_test mcast6_test

	all: $(TARGETS)

	clean:
	rm -f $(TARGETS)
	/*
	* IPv6 Multicast testing utility.
	* Adapted from the IPv4 example in https://www.linuxjournal.com/article/3041
	*
	* Run on two separate machines with the same group/port as arguments to test multicast.
	*/
	/*
	* This is free software released under the GPL license.
	* See the GNU GPL for details.
	*
	* (c) Juan-Mariano de Goyeneche. 1998, 1999.
	* Modifications: (c) Robert Mihaly. 2020.
	* 2020-01-29: Modified original IPv4 code to use IPv6
	*
	*/
	#include <stdio.h> /* printf(), snprintf() */
	#include <stdlib.h> /* strtol(), exit() */
	#include <sys/types.h>
	#include <sys/socket.h> /* socket(), setsockopt(), bind(), recvfrom(), sendto() */
	#include <errno.h> /* perror() */
	#include <netinet/in.h> /* IPPROTO_IP, sockaddr_in, htons(), htonl() */
	#include <arpa/inet.h> /* inet_addr() */
	#include <unistd.h> /* fork(), sleep() */
	#include <sys/utsname.h> /* uname() */
	#include <string.h> /* memset() */

	#define MAXLEN 1024
	#define DELAY 2
	#define TTL 1

	int main(int argc, char* argv[])
	{
	u_int no = 0;
	u_int yes = 1; /* Used with SO_REUSEADDR. In Linux both u_int */
	/* and u_char are valid. */
	int send_s, recv_s; /* Sockets for sending and receiving. */
	int ttl;
	struct sockaddr_in6 mcast_group;
	struct ipv6_mreq mreq;
	struct utsname name;
	char buf6[INET6_ADDRSTRLEN];

	if ((argc<3) \|\| (argc>4)) {
	fprintf(stderr, "Usage: %s mcast_group port [ttl]\n", argv[0]);
	exit(1);
	}

	memset(&mcast_group, 0, sizeof(mcast_group));
	mcast_group.sin6_family = AF_INET6;
	mcast_group.sin6_port = htons((unsigned short int)strtol(argv[2], NULL, 0));
	inet_pton(AF_INET6, argv[1], &mcast_group.sin6_addr);

	if ((send_s=socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
	perror ("send socket");
	exit(1);
	}

	/* If ttl supplied, set it */
	if (argc == 4) {
	ttl = strtol(argv[3], NULL, 0);
	} else {
	ttl = TTL;
	}
	printf("ttl = %d\n", ttl);

	if (setsockopt(send_s, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0) {
	perror ("ttl setsockopt");
	exit(1);
	}

	/* Disable Loop-back */
	if (setsockopt(send_s, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &no, sizeof(no)) < 0) {
	perror ("loop setsockopt");
	exit(1);
	}

	if ((recv_s=socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
	perror ("recv socket");
	exit(1);
	}

	if (setsockopt(recv_s, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) {
	perror("reuseaddr setsockopt");
	exit(1);
	}

	if (bind(recv_s, (struct sockaddr*)&mcast_group,sizeof(mcast_group)) < 0){
	perror ("bind");
	exit(1);
	}

	/* Tell the kernel we want to join that multicast group. */
	mreq.ipv6mr_multiaddr = mcast_group.sin6_addr;
	mreq.ipv6mr_interface = INADDR_ANY;

	if (setsockopt(recv_s, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
	perror ("add_membership setsockopt");
	exit(1);
	}

	if (uname(&name) < 0) {
	perror ("uname");
	exit(1);
	}

	switch (fork()) {
	case -1: /* Error fork()ing */
	perror("fork");
	exit(1);
	case 0: { /* Child -> receive. */
	int n;
	int len;
	struct sockaddr_in6 from;
	char message [MAXLEN+1];

	for (;;) {
	len=sizeof(from);
	if ((n=recvfrom(recv_s, message, MAXLEN, 0, (struct sockaddr*)&from, &len)) < 0) {
	perror ("recv");
	exit(1);
	}
	inet_ntop(AF_INET6, &from.sin6_addr, buf6, sizeof(buf6));
	message[n] = 0; /* null-terminate string */
	printf("%s: Received message from %s.\n", name.nodename, buf6);
	printf("\t%s", message);
	}
	/* Not reached. */
	}
	default: { /* Parent -> send. */
	char message [MAXLEN];
	snprintf (message, sizeof(message), "Hi, I'm %s. "
	"Merry Christmas!\t(TTL==%d)\n", name.nodename, ttl);
	for (;;) {
	if (sendto(send_s, message, strlen(message), 0, (struct sockaddr*)&mcast_group, sizeof(mcast_group)) < strlen(message)) {
	perror("sendto");
	exit(1);
	}
	sleep(DELAY);
	}
	/* Not reached. */
	}
	}
	/* Not really reached. */
	}
	/*
	* IPv4 Multicast testing utility.
	* Source: Multicast: From Theory to Practice in Linux Journal
	* https://www.linuxjournal.com/article/3041
	*
	* Run on two separate machines with the same group/port as arguments to test multicast.
	*/
	/*
	* This is free software released under the GPL license.
	* See the GNU GPL for details.
	*
	* (c) Juan-Mariano de Goyeneche. 1998, 1999.
	*
	*/

	#include <stdio.h> /* printf(), snprintf() */
	#include <stdlib.h> /* strtol(), exit() */
	#include <sys/types.h>
	#include <sys/socket.h> /* socket(), setsockopt(), bind(), recvfrom(), sendto() */
	#include <errno.h> /* perror() */
	#include <netinet/in.h> /* IPPROTO_IP, sockaddr_in, htons(), htonl() */
	#include <arpa/inet.h> /* inet_addr() */
	#include <unistd.h> /* fork(), sleep() */
	#include <sys/utsname.h> /* uname() */
	#include <string.h> /* memset() */

	#define MAXLEN 1024
	#define DELAY 2
	#define TTL 1

	int main(int argc, char* argv[])
	{
	u_char no = 0;
	u_int yes = 1; /* Used with SO_REUSEADDR. In Linux both u_int */
	/* and u_char are valid. */
	int send_s, recv_s; /* Sockets for sending and receiving. */
	u_char ttl;
	struct sockaddr_in mcast_group;
	struct ip_mreq mreq;
	struct utsname name;

	if ((argc<3) \|\| (argc>4)) {
	fprintf(stderr, "Usage: %s mcast_group port [ttl]\n", argv[0]);
	exit(1);
	}

	memset(&mcast_group, 0, sizeof(mcast_group));
	mcast_group.sin_family = AF_INET;
	mcast_group.sin_port = htons((unsigned short int)strtol(argv[2], NULL, 0));
	mcast_group.sin_addr.s_addr = inet_addr(argv[1]);

	if ((send_s=socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
	perror ("send socket");
	exit(1);
	}

	/* If ttl supplied, set it */
	if (argc == 4) {
	ttl = strtol(argv[3], NULL, 0);
	} else {
	ttl = TTL;
	}

	if (setsockopt(send_s, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0) {
	perror ("ttl setsockopt");
	exit(1);
	}

	/* Disable Loop-back */
	if (setsockopt(send_s, IPPROTO_IP, IP_MULTICAST_LOOP, &no, sizeof(no)) < 0) {
	perror ("loop setsockopt");
	exit(1);
	}

	if ((recv_s=socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
	perror ("recv socket");
	exit(1);
	}

	if (setsockopt(recv_s, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) {
	perror("reuseaddr setsockopt");
	exit(1);
	}

	if (bind(recv_s, (struct sockaddr*)&mcast_group,sizeof(mcast_group)) < 0){
	perror ("bind");
	exit(1);
	}

	/* Tell the kernel we want to join that multicast group. */
	mreq.imr_multiaddr = mcast_group.sin_addr;
	mreq.imr_interface.s_addr = htonl(INADDR_ANY);

	if (setsockopt(recv_s, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
	perror ("add_membership setsockopt");
	exit(1);
	}

	if (uname(&name) < 0) {
	perror ("uname");
	exit(1);
	}

	switch (fork()) {
	case -1: /* Error fork()ing */
	perror("fork");
	exit(1);
	case 0: { /* Child -> receive. */
	int n;
	int len;
	struct sockaddr_in from;
	char message [MAXLEN+1];

	for (;;) {
	len=sizeof(from);
	if ((n=recvfrom(recv_s, message, MAXLEN, 0, (struct sockaddr*)&from, &len)) < 0) {
	perror ("recv");
	exit(1);
	}
	message[n] = 0; /* null-terminate string */
	printf("%s: Received message from %s.\n", name.nodename, inet_ntoa(from.sin_addr));
	printf("\t%s", message);
	}
	/* Not reached. */
	}
	default: { /* Parent -> send. */
	char message [MAXLEN];
	snprintf (message, sizeof(message), "Hi, I'm %s. "
	"Merry Christmas!\t(TTL==%d)\n", name.nodename, ttl);
	for (;;) {
	if (sendto(send_s, message, strlen(message), 0, (struct sockaddr*)&mcast_group, sizeof(mcast_group)) < strlen(message)) {
	perror("sendto");
	exit(1);
	}
	sleep(DELAY);
	}
	/* Not reached. */
	}
	}
	/* Not really reached. */
	}