[clug] Securing EtherApe with setcap

[Bryan Kilgallin (PC)]

Thanks for the explanations, Bob:

> Essentially, the kernel deals with the lower-levels of the network
> protocol stack and only delivers the data part of a packet from the
> transport layer (UDP, TCP or other) to an application (user-space
> program).

The EtherApe Capture menu lists Mode. Which can be Link Layer, IP or TCP.

> As the transport layer is responsible for determining what "port" a
> packet belongs to, it keeps network traffic flowing only to the intended
> destination program.

An EtherApe legend is listing the protocols ICMPV6, IGMP, ARP, DOMAIN, 
HTTPS, POP3, HTTP, UDP-UNKN.

> This is also part of the "security model" that Linux has inherited from
> BSD and similar Unices etc.

{*Berkeley Software Distribution* (*BSD*) is a Unix 
<https://en.wikipedia.org/wiki/Unix> operating system 
<https://en.wikipedia.org/wiki/Operating_system> derivative developed 
and distributed by the Computer Systems Research Group 
<https://en.wikipedia.org/wiki/Computer_Systems_Research_Group> (CSRG) 
of the University of California, Berkeley 
<https://en.wikipedia.org/wiki/University_of_California,_Berkeley>, from 
1977 to 1995.}

I understand that Linux is merely Unix-like.

https://en.wikipedia.org/wiki/Berkeley_Software_Distribution

> The "raw" interface allows the kernel to deliver network packets from
> the data-link layer (layer 2) to user-space programs, if they wish.

I have only a hazy idea of this concept.

{From lowest to highest, the layers are the link layer 
<https://en.wikipedia.org/wiki/Link_layer>, containing communication 
methods for data that remains within a single network segment (link); 
the internet layer <https://en.wikipedia.org/wiki/Internet_layer>, 
connecting independent networks, thus providing internetworking 
<https://en.wikipedia.org/wiki/Internetworking>; the transport layer 
<https://en.wikipedia.org/wiki/Transport_layer> handling host-to-host 
communication; and the application layer 
<https://en.wikipedia.org/wiki/Application_layer>, which provides 
process-to-process data exchange for applications.}

https://en.wikipedia.org/wiki/Internet_protocol_suite

Regards,
Bryan.

-- 
www.netspeed.com.au/bryan/
==========================