1 zga klaar, 2 wat comments erbij gez-et

diff --git a/1intro.tex b/1intro.tex
index b25808d..88cd5f1 100644 (file)
--- a/1intro.tex
+++ b/1intro.tex
@@ -15,34 +15,34 @@ conformity to the specification of an \emph{existing} implementation.
 
 \subsection{SUT}
 %3,4
-The \textit{System under test} (SUT) is a
-Java\footnote{\url{http://www.java.com}} TCP driven echo server that executed
-on a virtualized Ubuntu system\footnote{\url{http://www.ubuntu.com}} running on
-the Linux kernel\footnote{\url{http://www.kernel.org}} version $3.13$. To test
-the error behaviour custom iptables output policies have to be set
-Listing~\ref{listing:iptables}. This is needed because the kernel by default
-closes all connections from unknown sources and the manually created TCP
-packets used in testing the implementation are from a source unknown to the
-kernel.
+The \textit{System under test} (SUT) is the TCP implementation of a system
+running a Linux kernel\footnote{\url{http://www.kernel.org}} version $3.13$.
+TCP is not a program that runs on its own and therefore we have to make use of
+some tools to be able to test the protocol. This is further described in
+Section~\ref{section:testenv}.
 
-\begin{lstlisting}[label={listing:iptables},caption={settings iptables}]
-Chain OUTPUT (policy ACCEPT)
-target prot    opt     source  destination
-ACCEPT tcp     --      anywhere        anywhere        tcp flags:PSH/PSH
-DROP   tcp     --      anywhere        anywhere        tcp flags:RST/RST
-\end{lstlisting}
+The specification of TCP is too big to be tested in one go so we focus on
+specific sections from \textit{RFC793}.
+\begin{itemize}
+       \item Sequence numbers~\cite[Section~3.3]{rfc793}.
+       \item Setting up a connection via the 
+               ``Three-way handshake''~\cite[Section~3.4]{rfc793}.
+       \item Closing a connection~\cite[Section~3.5]{rfc793}.
+       \item Data communication~\cite[Section~3.7]{rfc793}.
+\end{itemize}
 
-\subsection{Risks} \label{sec:risks}
+\subsection{Risks}
+\label{sec:risks}
 %5. Risks
 Risks can be divided into two categories. Project risks and product risks.
-Because an existing implementation is used the project risks are non
+Because an existing implementation is tested the project risks are non
 applicable. Product risks however are very important since it is unknown if the
 product has been tested during development.
 
 The product risks for the SUT are significant because misbehaviour of the SUT
 could have potential large consequences. The key characteristics of TCP are
-integrity and reliability~\cite{rfc793}, these characteristics cease to exist
-when the implementation is faulty.
+integrity and reliability~\cite[Section~1]{rfc793}, these characteristics cease
+to exist when the implementation is faulty.
 
 Because TCP is a core functionality of a networking capable system it is
 crucial that the TCP implementation functions according to the specification.
@@ -50,4 +50,8 @@ Several critical systems could rely on the correct functionality of the TCP
 implementation. A failure in the SUT could therefore have extensive
 consequences. Even more so since TCP is a computer-to-computer protocol, which
 leaves no room for ambiguity, which could be solved in a computer-to-human
-protocol.
+protocol. Another effect of the SUT being a computer-to-computer protocol
+without a standalone program is the fact that we can only observe the SUT
+indirectly. With the use of tools we can see what the output is for a given
+input but there is always the risk that the tools give an incomplete or faulty
+view of the output.

diff --git a/2approach.tex b/2approach.tex
index c982a86..76b1e1a 100644 (file)
--- a/2approach.tex
+++ b/2approach.tex
@@ -159,8 +159,23 @@ parameters:
 \end{enumerate}
 
 \subsubsection{Test environment and automatization}
-All the tools we are going to use together with the SUT gives us the following
-collection of software.
+\label{section:testenv}
+%%%Java\footnote{\url{http://www.java.com}} TCP driven echo server that executed
+%%%on a virtualized Ubuntu system\footnote{\url{http://www.ubuntu.com}} running on
+%%%the error behaviour custom iptables output policies have to be set
+%%%Listing~\ref{listing:iptables}. This is needed because the kernel by default
+%%%closes all connections from unknown sources and the manually created TCP
+%%%packets used in testing the implementation are from a source unknown to the
+%%%kernel.
+%%%
+%%%\begin{lstlisting}[label={listing:iptables},caption={settings iptables}]
+%%%Chain OUTPUT (policy ACCEPT)
+%%%target      prot    opt     source  destination
+%%%ACCEPT      tcp     --      anywhere        anywhere        tcp flags:PSH/PSH
+%%%DROP        tcp     --      anywhere        anywhere        tcp flags:RST/RST
+%%%\end{lstlisting}
+%%%All the tools we are going to use together with the SUT gives us the following
+%%%collection of software.
 
 \begin{enumerate}
        \item Windows, used as a host OS.