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  • Yotam Gigi's avatar
    net: Introduce psample, a new genetlink channel for packet sampling · 6ae0a628
    Yotam Gigi authored
    
    
    Add a general way for kernel modules to sample packets, without being tied
    to any specific subsystem. This netlink channel can be used by tc,
    iptables, etc. and allow to standardize packet sampling in the kernel.
    
    For every sampled packet, the psample module adds the following metadata
    fields:
    
    PSAMPLE_ATTR_IIFINDEX - the packets input ifindex, if applicable
    
    PSAMPLE_ATTR_OIFINDEX - the packet output ifindex, if applicable
    
    PSAMPLE_ATTR_ORIGSIZE - the packet's original size, in case it has been
       truncated during sampling
    
    PSAMPLE_ATTR_SAMPLE_GROUP - the packet's sample group, which is set by the
       user who initiated the sampling. This field allows the user to
       differentiate between several samplers working simultaneously and
       filter packets relevant to him
    
    PSAMPLE_ATTR_GROUP_SEQ - sequence counter of last sent packet. The
       sequence is kept for each group
    
    PSAMPLE_ATTR_SAMPLE_RATE - the sampling rate used for sampling the packets
    
    PSAMPLE_ATTR_DATA - the actual packet bits
    
    The sampled packets are sent to the PSAMPLE_NL_MCGRP_SAMPLE multicast
    group. In addition, add the GET_GROUPS netlink command which allows the
    user to see the current sample groups, their refcount and sequence number.
    This command currently supports only netlink dump mode.
    
    Signed-off-by: default avatarYotam Gigi <yotamg@mellanox.com>
    Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
    Reviewed-by: default avatarJamal Hadi Salim <jhs@mojatatu.com>
    Reviewed-by: default avatarSimon Horman <simon.horman@netronome.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    6ae0a628