how to use multicast with Interniche

Hi

I have the same problem.

Defining IP_MULTICAST is not the only thing to do.

I join a small guide provided by Altera.

Compilation is OK but It doesn't work for me.

I think we have to modify mcastlist() routine located in allports.c.

But I don't know exactly what to do.

Mikael.

Hi,

I have worked out how to do multicast, i am posting the steps here for everyone to share.

1. in IPPORT.h

You need to turn on 3 defines.

# define IP_MULTICAST 1 // obvious one# define ETHMCAST 1 // give the readme.txt in ipmc directory, turn this one# define IGMP_V2 // This is not mentioned anywhere, i figured it out myself by reading the code

2. Do whatever you need to get it compiled. Eg undefine IN_MENUS, comment out codes that causes compilation errors. Appearently they are bunch of code relates to ipmc demostration, and they have no use at all. I would strongly recommend altera to remove them from being compiled in by default, they cause so much confusion.

3. define a dummy mcastlist()

nets[0]->n_mcastlist = this_mcastlist;

Giving the documentation it said, the idea is to have this done at the mac level.

And i am using tse, there is an option called multicast hash table which you can enable. But anyway, i am a pure software guy, i dont have much idea there.

But in my case, i did not turn on the option in tse (I tried to turn it on, but then my fpga would not compile, and i am not a hardware guy, i dont know how to fix it). I simply used a dummy mcastlist(), it works anyway.

That is all, multicast should work now.

BTW, if anyone knows how to detect ethernet cable disconnection, that'd be good. I looked around in TSE and Interniche code, it does not seem possible.

Hi

Thanks for your response, I have just a little problem.

I defined a dummy mcastlist() :

int dummy_mcastlist(struct in_multi * multi_ptr)
{
USE_ARG(multi_ptr);
return 0;
}

And I put this line just after Nichestack initialization

extern int dummy_mcastlist(struct in_multi * multi_ptr)
...
while (!iniche_net_ready)
    TK_SLEEP(1);
nets->n_mcastlist = dummy_mcastlist;

Compilation is OK but setsockopt() fails on MULTICAST_IF :

   memset(&local_addr,0,sizeof(local_addr)); 
    local_addr.sin_family = AF_INET;
    local_addr.sin_port = htons(USED_PORT);
    local_addr.sin_addr.s_addr = htonl(INADDR_ANY);    
    if((setsockopt (sock, IPPROTO_IP, IP_MULTICAST_IF,(char*) &local_addr,sizeof(local_addr)))<0)
    {
    fprintf(stderr,"multicast_if failed\n");}

I am not able to send multicast packet.

What's wrong?

Have I to do some changes in allports.c?

Thanks.

Mikael.

Hi

I am now able to set IP_MULTICAST_IF and IP_ADD_MEMBERSHIP options.

It was a socket programming error:

considere the following code :

 struct in_addr local_addr;
   IP4_ADDR(local_address.s_addr,192,168,1,2);
    
    if((setsockopt (sock, IPPROTO_IP,    IP_MULTICAST_IF,&local_addr,sizeof(local_addr)))<0)
    {
    fprintf(stderr,"multicast_if failed\n");}

But sendto always returns an error.

Any idea?

Thanks.

Mikael.