Mark wrote:
> "Les Cargill" <lcargil...@comcast.com> wrote in message
> news:k7fdln$248$1@dont-email.me...
>>> static struct proto_ops igmp_snoop_ops = {
>>>      family:       AF_IGMP_SNOOP,
>>>      release:      _igmp_snoop_sock_release,
>>>      bind:         sock_no_bind,
>>>      connect:      sock_no_connect,
>>>      socketpair:   sock_no_socketpair,
>>>      accept:       sock_no_accept,
>>>      getname:      sock_no_getname,
>>>      poll:         datagram_poll,
>>>      ioctl:        sock_no_ioctl,
>>>      listen:       sock_no_listen,
>>>      shutdown:     sock_no_shutdown,
>>>      setsockopt:   _igmp_snoop_setsockopt,
>>>      getsockopt:   sock_no_getsockopt,
>>>      sendmsg:      _igmp_snoop_sock_sendmsg,
>>>      recvmsg:      _igmp_snoop_sock_recvmsg,
>>>      mmap:         sock_no_mmap,
>>>      sendpage:     sock_no_sendpage,
>>> }

>>> However from a user space perspective a socket is created as:

>>> fd = socket (AF_IGMPSNOOP, SOCK_RAW, IPPROTO_IGMP)

>>> I'm wondering what is the rationale for adding a new family, while in
>>> fact a
>>> raw socket is being used to access the stack for IGMP packets? Would not
>>> it
>>> be the same to just create AF_INET raw socket and do the things?

>> Possibly.

>> I'm pretty sure IGMP snooping is really a "bridge" thing.

>> http://www.linuxfoundation.org/collaborate/workgroups/networking/brid...

>> I don't know why you'd need a socket for bridge-based IGMP snooping
>> at all. Bridges don't need no steenking sockets.  This being said, this
>> is another one of those things...

> Thanks for the response.
> Another thing that comes to my mind is that perhaps the implementor of
> AF_IGMPSNOOP family wanted to have just a small subset of socket operations,
> not a full-blown socket, basically only the 'release', 'poll', setsockopt,
> sendmsg and recvmsg are implemented for this new family. May be they wanted
> to have a light-weight mechanism.

> Mark