Feature: Promiscuous mode

[imsnif]

On network interfaces, promiscuous mode would indicate a situation where traffic sent to the interface might not necessarily be addressed to it. An example of such a use case would be to connect a sniffer to a switch port that mirrors the traffic of a different switch port.

In such a situation, bandwhich cannot rely on information regarding system processes, because there is no guarantee the traffic originates at or is intended for processes on the system. It also cannot ascertain the "direction" of the traffic (using pcap as we do), because it cannot match any of the source or destination addresses (IPs or MAC addresses) to anything on the system. The only valuable information bandwhich can display in this case is the "connections" table.

If we start bandwhich with --promiscuous, we would only be displaying the connections table. On each connection, instead of showing the network card, we would be showing the source ip.

When started in promiscuous mode, we should:

• Store both the source and destination IP of each packet
• Store network utilization by connection rather than by local socket (identifying upload and download by the direction of the packet, indicated by its source and destination).
• Render only the connections table
• Stringify connections as "[IP/HOST 1]:[PORT 1] <=> [IP/HOST 2]:[PORT 2] (tcp/udp/icmp)"
• Allow network interfaces that are down or have no IPs.

This follows a conversation here: #140