Update the count of open sockets
tcpmib.CurrEstab
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 CurrEstab (equivalent to SNMP's MIB TCP_MIB_CURRESTAB)