• S
    fib_rules: add .suppress operation · 7764a45a
    Stefan Tomanek 提交于
    This change adds a new operation to the fib_rules_ops struct; it allows the
    suppression of routing decisions if certain criteria are not met by its
    results.
    
    The first implemented constraint is a minimum prefix length added to the
    structures of routing rules. If a rule is added with a minimum prefix length
    >0, only routes meeting this threshold will be considered. Any other (more
    general) routing table entries will be ignored.
    
    When configuring a system with multiple network uplinks and default routes, it
    is often convinient to reference the main routing table multiple times - but
    omitting the default route. Using this patch and a modified "ip" utility, this
    can be achieved by using the following command sequence:
    
      $ ip route add table secuplink default via 10.42.23.1
    
      $ ip rule add pref 100            table main prefixlength 1
      $ ip rule add pref 150 fwmark 0xA table secuplink
    
    With this setup, packets marked 0xA will be processed by the additional routing
    table "secuplink", but only if no suitable route in the main routing table can
    be found. By using a minimal prefixlength of 1, the default route (/0) of the
    table "main" is hidden to packets processed by rule 100; packets traveling to
    destinations with more specific routing entries are processed as usual.
    Signed-off-by: NStefan Tomanek <stefan.tomanek@wertarbyte.de>
    Signed-off-by: NDavid S. Miller <davem@davemloft.net>
    7764a45a
fib6_rules.c 7.3 KB