• Patrick McHardy's avatar
    ipv4: ipmr: support multiple tables · f0ad0860
    Patrick McHardy authored
    This patch adds support for multiple independant multicast routing instances,
    named "tables".
    
    Userspace multicast routing daemons can bind to a specific table instance by
    issuing a setsockopt call using a new option MRT_TABLE. The table number is
    stored in the raw socket data and affects all following ipmr setsockopt(),
    getsockopt() and ioctl() calls. By default, a single table (RT_TABLE_DEFAULT)
    is created with a default routing rule pointing to it. Newly created pimreg
    devices have the table number appended ("pimregX"), with the exception of
    devices created in the default table, which are named just "pimreg" for
    compatibility reasons.
    
    Packets are directed to a specific table instance using routing rules,
    similar to how regular routing rules work. Currently iif, oif and mark
    are supported as keys, source and destination addresses could be supported
    additionally.
    
    Example usage:
    
    - bind pimd/xorp/... to a specific table:
    
    uint32_t table = 123;
    setsockopt(fd, IPPROTO_IP, MRT_TABLE, &table, sizeof(table));
    
    - create routing rules directing packets to the new table:
    
    # ip mrule add iif eth0 lookup 123
    # ip mrule add oif eth0 lookup 123
    Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    f0ad0860
ipv4.h 1.54 KB