• Linus Lüssing's avatar
    bridge: simplify ip_mc_check_igmp() and ipv6_mc_check_mld() calls · ba5ea614
    Linus Lüssing authored
    This patch refactors ip_mc_check_igmp(), ipv6_mc_check_mld() and
    their callers (more precisely, the Linux bridge) to not rely on
    the skb_trimmed parameter anymore.
    
    An skb with its tail trimmed to the IP packet length was initially
    introduced for the following three reasons:
    
    1) To be able to verify the ICMPv6 checksum.
    2) To be able to distinguish the version of an IGMP or MLD query.
       They are distinguishable only by their size.
    3) To avoid parsing data for an IGMPv3 or MLDv2 report that is
       beyond the IP packet but still within the skb.
    
    The first case still uses a cloned and potentially trimmed skb to
    verfiy. However, there is no need to propagate it to the caller.
    For the second and third case explicit IP packet length checks were
    added.
    
    This hopefully makes ip_mc_check_igmp() and ipv6_mc_check_mld() easier
    to read and verfiy, as well as easier to use.
    Signed-off-by: default avatarLinus Lüssing <linus.luessing@c0d3.blue>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    ba5ea614
multicast.c 47.9 KB