• Ondřej Zajíček's avatar
    Basic VRF support · 943478b0
    Ondřej Zajíček authored
    Add basic VRF (virtual routing and forwarding) support. Protocols can be
    associated with VRFs, such protocols will be restricted to interfaces
    assigned to the VRF (as reported by Linux kernel) and will use sockets
    bound to the VRF. E.g., different multihop BGP instances can use diffent
    kernel routing tables to handle BGP TCP connections.
    
    The VRF support is preliminary, currently there are several limitations:
    
    - Recent Linux kernels (4.11) do not handle correctly sockets bound
    to interaces that are part of VRF, so most protocols other than multihop
    BGP do not work. This will be fixed by future kernel versions.
    
    - Neighbor cache ignores VRFs. Breaks config with the same prefix on
    local interfaces in different VRFs. Not much problem as single hop
    protocols do not work anyways.
    
    - Olock code ignores VRFs. Breaks config with multiple BGP peers with the
    same IP address in different VRFs.
    
    - Incoming BGP connections are not dispatched according to VRFs.
    Breaks config with multiple BGP peers with the same IP address in
    different VRFs. Perhaps we would need some kernel API to read VRF of
    incoming connection? Or probably use multiple listening sockets in
    int-new branch.
    
    - We should handle master VRF interface up/down events and perhaps
    disable associated protocols when VRF goes down. Or at least disable
    associated interfaces.
    
    - Also we should check if the master iface is really VRF iface and
    not some other kind of master iface.
    
    - BFD session request dispatch should be aware of VRFs.
    
    - Perhaps kernel protocol should read default kernel table ID from VRF
    iface so it is not necessary to configure it.
    
    - Perhaps we should have per-VRF default table.
    943478b0