Count the passive creation of a socket
tcpmib.PassiveOpens
op
value to be added to the counter (default value of 1)
sk
pointer to the struct sock being acted on
The packet pointed to by skb is filtered by the function tcpmib_filter_key. If the packet passes the filter is is counted in the global PassiveOpens (equivalent to SNMP's MIB TCP_MIB_PASSIVEOPENS)