Active sessions

[admin]

You can filter the result by local port (80 or 443) and also by TCP state. TCP_ESTABLISHED should be enough since visualization uses web sockets where connection is always open during an active session.

Code:

states = {
  'TCP_ESTABLISHED',
  'TCP_SYN_SENT',
  'TCP_SYN_RECV',
  'TCP_FIN_WAIT1',
  'TCP_FIN_WAIT2',
  'TCP_TIME_WAIT',
  'TCP_CLOSE',
  'TCP_CLOSE_WAIT',
  'TCP_LAST_ACK',
  'TCP_LISTEN',
  'TCP_CLOSING',
};

-- convert hex to readable IP
function toip(hex)
  local res = {}

  for i = 4, 1, -1 do
    local j = (i - 1) * 2 + 1
    local ch = hex:sub(j, j + 1)
    res[ #res + 1 ] = tonumber(ch, 16)
  end

  return table.concat(res, '.')
end

for line in io.lines('/proc/net/tcp') do
  local_ip, local_port, remote_ip, remote_port, state =
    line:match('(%x+):(%x+)%s+(%x+):(%x+)%s+(%x+)')

  -- valid line
  if local_ip and local_port and remote_ip and remote_port and state then
    local_ip = toip(local_ip)
    local_port = tonumber(local_port, 16)

    remote_ip = toip(remote_ip)
    remote_port = tonumber(remote_port, 16)

    state = states[ tonumber(state, 16) ]

    log(local_ip, local_port, remote_ip, remote_port, state)
  end
end