Andi, David, I disagree. If you suspect we would be better using IP multicast, I think your suspects are not supported. Try the following exercises, please.... Can you provide better solutions without IPN?
renzo Exercise #1. I am a user (NOT ROOT), I like kvm, qemu etc. I want an efficient network between my VM. My solution: I Create a IPN socket, with protocol IPN_VDESWITCH and all the VM can communicate. Your solution: - I am condamned by two kernel developers to run the switch in the userland - I beg the sysadm to give me some pre-allocated taps connected together by a kernel bridge. - I create a multicast socket limited to this host (TTL=0) and I use it like a hub. It cannot switch the packets. Exercise #2. I am a sysadm (maybe a lab administrator). I want my users (not root) of the group "vmenabled" to run their VM connected to a network. I have hundreds of users in vmenabled(say students). My Solution: I create a IPN socket, with protocol IPN_VDESWITCH, connected to a virtual interface say ipn0. I give to the socket permission 760 owner root:vmenabled. Your solution: - I am condamned by two kernel developers to run the switch in the userland - I create a multicast socket connected to a tap and then I define iptables filters to avoid unauthorized users to join the net. - I create hundreds of preallocated tap interfaces, at least one per user. Exercise #3. I am a user (NOT ROOT) and I have a heavy stream of *very private data* generated by some processes that must be received by several processes. I am looking for an efficient solution. Data can be ASCII strings, or a binary stream. It is not a "networking" issue, it is just IPC. My solution. I Create a IPN socket with permission 700, IPN_BROADCAST protocol. All the processes connect to the socket either for writing or for reading (or both). Your solution: - I am condamned by two kernel developers to use userland inefficient solutions like named pipes, tee, or a user daemon among AF_UNIX sockets. - If I use multicast, others can read the stream. (security by obscurity? the attacker do not know the address?) - I use a multicast socket with SSL (it sounds funny to use encryption to talk with myself, exposing the stream to crypto attack). -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/