X-Git-Url: https://git.martlubbers.net/?a=blobdiff_plain;f=a2%2F1cases.tex;h=2d27d9bb7ea7e6783b1cbef34bf4c0a42b7c8fab;hb=77b0b50ede869e3643b063c90910cbacebd4b57b;hp=c6afba27d640e8ba46a55f444d8ee049f7c512b1;hpb=97331f69d92ae883d0436894e3c0f19fe1a0c550;p=tt2015.git diff --git a/a2/1cases.tex b/a2/1cases.tex index c6afba2..2d27d9b 100644 --- a/a2/1cases.tex +++ b/a2/1cases.tex @@ -91,13 +91,14 @@ a feasible test suite the tests are divided into equivalence partitions. Below these partitions are given. \begin{enumerate} - \item \emph{Number of packets} in request~\footnote{A request is considered - establishing a connection (handshake) and a number of payload packets} + \item \emph{Number of segments} in request~\footnote{A request is + considered establishing a connection (handshake) and a number of + payload segments} \begin{enumerate} - \item 0 payload packets - \item 1 payload packet - \item n=small payload packets - \item n=big payload packets + \item 0 payload segments + \item 1 payload segments + \item n=small payload segments (1 byte) + \item n=big payload segments (65495 bytes) \end{enumerate} \item \emph{source port} \begin{enumerate} @@ -109,53 +110,88 @@ these partitions are given. \item Correct \item Incorrect \end{enumerate} - \item Bits flipped in \emph{payload} + \item Bit errors in \emph{payload} \begin{enumerate} \item Correct payload - \item Payload with even number of bits flipped - \item Payload with odd number of bits flipped + \item Payload with bit flips that do not show in checksum + \item Payload with bit flips that do show in checksum \end{enumerate} \item \emph{checksum} \begin{enumerate} \item Correct \item Incorrect \end{enumerate} - \item Packet order + \item \emph{Segment order} \begin{enumerate} \item Correct \item Out of order - \item Missing packets + \item Missing Segments \end{enumerate} \end{enumerate} -\textbf{hier iets over waarom deze partities relevant zijn! Waarom odd en -even number of bits flipped bijv interessant?} +These partitions were chosen since they correspond to key parts of the TCP +specification. + +TCP segments are send over a TCP connection from a \emph{source} to a \emph{destination port}. Therefore segments which are received that have a +source or destination port set to an incorrect value should not be regarded +as segments belonging to the connection by the SUT. + +TCP uses a \emph{checksum} to catch any error introduced in headers, when this +checksum does not match the actual computed checksum the SUT should +disregard the received segment. + +The TCP checksum is also an inherently weak one, as it is simply the +bitwise negation of the addition, in ones complement arithmetic, +of all 16 bit words in the header and data of the segment (excluding the +checksum itself). Therefore any \emph{bit error} where the ones complement value +of one word +increases by one, and the value of another decreases by one, is undetected. +The SUT should exhibit the same behavior and accept packets where these type +of bit errors occur. + +TCP guarantees that segments are delivered \emph{in order} +,even when they are received +out of order and that missing segments are resend. The SUT should +exhibit the same behavior. If segments are received out of order it should +either reassemble them when the missing packet has arrived or request them to +be resend when the Missing segments should be re-requested (by ACK-ing +the correct sequence number). + \bigskip Partitions 2 to 6 are tested using pairwise testing to keep the number of test cases feasible. The pairs are then all *except some where it does not make sense to do so) tested with the different request sizes of partition 1. -This is expressed in Table~\ref{table:testpairs}. +This is expressed in Table~\ref{table:testpairs}. In this table the first five +columns represent the different options for the partitions 2 to 6 of the above +enumeration. The last four columns are the different number segments as +described in the partition 1 of the above enumeration. These cells identify +individual test cases by a number. An \xmark in the cell indicates that this +test case can not be created as it is not possible with that number of segments +(eg. sending segments out of order when the number of segments is 1). +\newcounter{TCC} +\setcounter{TCC}{1} +\newcommand{\doTCC}{\theTCC \stepcounter{TCC}} \begin{table}[H] \centering - \begin{tabular}{|l|l|l|l|l|l|l|l|l|l|l|} + \begin{tabular}{|l|l|l|l|l|l||l|l|l|l|} \hline - & \multicolumn{10}{c|}{\textbf{Partition}}\\ + & \multicolumn{9}{c|}{\textbf{Partition}}\\ \hline - & \# & 4 & 5 & 3 & 6 & 2 & 1a & 1b & 1c & 1d\\ + & 4 & 5 & 3 & 6 & 2 & 1a & 1b & 1c & 1d\\ \hline\hline \multirow{9}{*}{Instance} - & 1 & a & a & a & a & a & \checkmark & \checkmark & \checkmark & \checkmark\\ - & 2 & a & b & b & c & b & \xmark & \xmark & \checkmark & \checkmark\\ - & 3 & c & a & b & a & b & \xmark & \xmark & \checkmark & \checkmark\\ - & 4 & c & b & a & c & a & \xmark & \xmark & \checkmark & \checkmark\\ - & 5 & b & a & b & c & a & \xmark & \xmark & \checkmark & \checkmark\\ - & 6 & b & b & a & b & b & \xmark & \xmark & \checkmark & \checkmark\\ - & 7 & c & b & b & a & b & \checkmark & \checkmark & \checkmark & \checkmark\\ - & 8 & b & b & b & a & b & \checkmark & \checkmark & \checkmark & \checkmark\\ - & 9 & a & b & b & b & a & \xmark & \xmark & \checkmark & \checkmark\\ + & a & a & a & a & a & \doTCC & \doTCC & \doTCC & \doTCC\\ + & a & b & b & c & b & \xmark & \xmark & \doTCC & \doTCC\\ + & c & a & b & a & b & \xmark & \xmark & \doTCC & \doTCC\\ + & c & b & a & c & a & \xmark & \xmark & \doTCC & \doTCC\\ + & b & a & b & c & a & \xmark & \xmark & \doTCC & \doTCC\\ + & b & b & a & b & b & \xmark & \xmark & \doTCC & \doTCC\\ + & c & b & b & a & b & \xmark & \doTCC & \doTCC & \doTCC\\ + & b & b & b & a & b & \xmark & \doTCC & \doTCC & \doTCC\\ + & a & b & b & b & a & \xmark & \xmark & \doTCC & \doTCC\\ \hline \end{tabular} \caption{Combinations of test cases} @@ -186,7 +222,14 @@ test suite can be clearly assessed. As always, $100\%$ completeness is not feasible, therefore test cases are carefully selected to cover the most interesting parts of the TCP specification -to ensure a test suite. +to ensure a complete but feasible test suite. + +To further increase the coverage of the test suites tests are randomized. The +tests which test the handling of \emph{bit errors}, changes in the \emph{packet +order} and \emph{dropped packets} randomize where they introduce an error. The +test suite runs these tests multiple times to increase the likelihood that they +discover a fault which is only present when an error occurs in a certain +position. To further decrease the number of tests needed test cases are divided into equivalence partitions and the combination of cases as described in @@ -202,7 +245,69 @@ covered and the number of individual tests is still feasible. \subsection{Test cases} -%\begin{table} +Before every test case use the following steps to initialize the testing environment. + +\begin{enumerate} + \item Boot the vm using VirtualBox. + \item Setup iptables by executing \texttt{\# code/iptables.sh} + \item Navigate to the working directory by running \texttt{\$ cd /home/student/tt2015} + \item Start the echo server by running \texttt{\# cd code/server \&\& java Main} +\end{enumerate} + +\begin{longtable}{|p{.2\linewidth}|p{.8\linewidth}|} + \hline + Nr & 1 \\\hline + Title & Single valid request with 1byte payload. \\\hline + Input & Generated packets. \\\hline + Expected output & Packets echoed back by Echo-Server. \\\hline + \multirow{2}{*}{Course of action} + & 1. Use the steps listed above in order to start the SUT. \\ + & 2. Execute the script by running \texttt{\# code/client/tests/1.py} \\\hline + Valid trace & Verify that the script prints 'Success'. \\\hline + \hline + + Nr & 2 \\\hline + Title & Single valid request with 65495bytes payload. \\\hline + Input & Generated packets. \\\hline + Expected output & Packets echoed back by Echo-Server. \\\hline + \multirow{2}{*}{Course of action} + & 1. Use the steps listed above in order to start the SUT. \\ + & 2. Execute the script by running \texttt{\# code/client/tests/2.py} \\\hline + Valid trace & Verify that the script prints 'Success'. \\\hline + \hline + + Nr & 3 \\\hline + Title & 5 valid requests with 1byte payload. \\\hline + Input & Generated packets. \\\hline + Expected output & Packets echoed back by Echo-Server, in the same order as the client sent them. \\\hline + \multirow{2}{*}{Course of action} + & 1. Use the steps listed above in order to start the SUT. \\ + & 2. Execute the script by running \texttt{\# code/client/tests/3.py} \\\hline + Valid trace & Verify that the script prints 'Success'. \\\hline + \hline + + Nr & 4 \\\hline + Title & 5 valid requests with 65495bytes payload. \\\hline + Input & Generated packets with 65495bytes payload. \\\hline + Expected output & Packets echoed back by Echo-Server, in the same order as the client sent them. \\\hline + \multirow{2}{*}{Course of action} + & 1. Use the steps listed above in order to start the SUT. \\ + & 2. Execute the script by running \texttt{\# code/client/tests/4.py} \\\hline + Valid trace & Verify that the script prints 'Success'. \\\hline + \hline + + Nr & 5 \\\hline + Title & 5 valid requests with 1byte payload sent out of order. \\\hline + Input & Generated packets with 1byte payload, two packets are swapped in position. \\\hline + Expected output & All requests sent up to and including + the swapped packet with the lowest sequence number, the remaining packets are dropped. \\\hline + \multirow{2}{*}{Course of action} + & 1. Use the steps listed above in order to start the SUT. \\ + & 2. Execute the script by running \texttt{\# code/client/tests/5.py} \\\hline + Valid trace & Verify that the script prints 'Success'. \\\hline + \hline +\end{longtable} + %\begin{tabularx}{\linewidth}{| l | X|} %\hline %Nr & 1 \\\hline