1 \subsection{Preflight checklist
}
2 Before actual certification is commenced we perform a manual test using a
4 If any of the checks fail we immediately reject the product.
5 The checklist is given in the table below. All commands in
\texttt{monospace
}
6 are to be run in a terminal. Commands prefixed with a
\texttt{\#
} should be run
7 with root permissions. Commands prefixed with a
\texttt{\$
} should be run with
10 \begin{longtable
}{|l|rp
{.8\linewidth}|
}
12 Check
1 &
\multicolumn{2}{l|
}{Get the SUT in a workable state.
}\\
14 \multirow{3}{*
}{Course of action
}
15 &
1. & Import the VirtualBox image into VirtualBox.\\
17 &
3. & Verify the SUT booted successfully and the network modules are
20 Passed &
\multicolumn{2}{l|
}{\textit{Yes/No
}}\\
22 Check
2 &
\multicolumn{2}{l|
}{Verify the SUT is complete.
}\\
24 \multirow{5}{*
}{Course of action
}
25 &
1. & Boot the SUT as in
\emph{Check
1}.\\
26 &
2. & Verify the loopback device exists by running
27 \texttt{\$ ifconfig
}.\\
28 &
3. & Verify the
\emph{echo-server
} is present on the system by running
29 \texttt{\$ file code/server/Main.java
}\\
30 &
4. & Verify
\emph{Scapy
} is present on the system by running
32 &
5. & Verify all scripts used for testing are present on the system.\\
34 Passed &
\multicolumn{2}{l|
}{\textit{Yes/No
}}\\
36 Check
3 &
\multicolumn{2}{l|
}{Initialize the testing environment..
}\\
38 \multirow{6}{*
}{Course of action
}
39 &
1. & Boot the SUT as in
\emph{Check
1}.\\
40 &
2. & Setup iptables by executing
41 \texttt{\# code/iptables.sh
}~
\footnote{The IPTables script ensures
42 that the OS does not drop packets due to an the unknown source.
}\\
43 &
3. & Navigate to the working directory by running
44 \texttt{\$ cd /home/student/tt2015
}\\
45 &
4. & Compile the echo server by running
46 \texttt{\# cd code/server \&\& make
}\\
47 &
5. & Start the echo server by running
48 \texttt{\# cd code/server \&\& java Main
}\\
49 &
6. & Generate all test cases by running
50 \texttt{\$ python code/client/gen.py
}\\
52 Passed &
\multicolumn{2}{l|
}{\textit{Yes/No
}}\\
54 Check
4 &
\multicolumn{2}{l|
}{Test the tool environment.
}\\
56 \multirow{3}{*
}{Course of action
}
57 &
1. & Initialize the SUT as in
\emph{Check
3}\\
58 &
2. & Execute the test script by running
59 \texttt{\# code/client/helloworld.py
}\\
60 &
3. & Verify the console displays a success message.\\
62 Passed &
\multicolumn{2}{l|
}{\textit{Yes/No
}}\\
64 Check
5 &
\multicolumn{2}{l|
}{All test inputs and scripts are present.
}\\
66 \multirow{2}{*
}{Course of action
}
67 &
1. & Boot the SUT as in
\emph{Check
1}.\\
68 &
2. & Verify that the test generation script is present by running
69 \texttt{\$ file code/client/test.py
}\\
71 Passed &
\multicolumn{2}{l|
}{\textit{Yes/No
}}\\
73 \caption{Preflight checklist
\label{tbl:preflight
}}
76 \subsection{Testing of SUT
}
77 The SUT is a series of services for other computer programs with no end-user
78 facing interface. Therefore the SUT will be tested solely by calling it's
79 services through various automated scripts. An automated test suite will be
80 available which executes all these automated scripts and aggregates their
81 results to asses whether or not the SUT has passed the test.
83 The implementation of the SUT is tested using black box testing techniques. A
84 series of tests asses the correctness of the implementation with regards to the
85 TCP specification. These tests are specified in Table~
\textbf{referentie naar
86 tests-tabel
}. The test cases aim to cover the most interesting parts of the TCP
89 To cover the TCP specification as complete as possible while still maintaining
90 a feasible test suite the tests are divided into equivalence partitions. Below
91 these partitions are given.
94 \item \emph{Number of segments
} in request~
\footnote{A request is
95 considered establishing a connection (handshake) and a number of
98 \item 0 payload segments
99 \item 1 payload segments
100 \item n=small payload segments (
1 byte)
101 \item n=big payload segments (
65495 bytes)
103 \item \emph{source port
}
108 \item \emph{destination port
}
113 \item Bit errors in
\emph{payload
}
115 \item Correct payload
116 \item Payload with bit flips that do not show in checksum
117 \item Payload with bit flips that do show in checksum
119 \item \emph{checksum
}
124 \item \emph{Segment order
}
128 \item Missing Segments
132 These partitions were chosen since they correspond to key parts of the TCP
135 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
136 source or destination port set to an incorrect value should not be regarded
137 as segments belonging to the connection by the SUT.
139 TCP uses a
\emph{checksum
} to catch any error introduced in headers, when this
140 checksum does not match the actual computed checksum the SUT should
141 disregard the received segment.
143 The TCP checksum is also an inherently weak one, as it is simply the
144 bitwise negation of the addition, in ones complement arithmetic,
145 of all
16 bit words in the header and data of the segment (excluding the
146 checksum itself). Therefore any
\emph{bit error
} where the ones complement value
148 increases by one, and the value of another decreases by one, is undetected.
149 The SUT should exhibit the same behavior and accept packets where these type
152 TCP guarantees that segments are delivered
\emph{in order
}
153 ,even when they are received
154 out of order and that missing segments are resend. The SUT should
155 exhibit the same behavior. If segments are received out of order it should
156 either reassemble them when the missing packet has arrived or request them to
157 be resend when the Missing segments should be re-requested (by ACK-ing
158 the correct sequence number).
162 Partitions
2 to
6 are tested using pairwise testing to keep the number of test
163 cases feasible. The pairs are then all *except some where it does not make sense
164 to do so) tested with the different request sizes of partition
1.
166 This is expressed in Table~
\ref{table:testpairs
}. In this table the first five
167 columns represent the different options for the partitions
2 to
6 of the above
168 enumeration. The last four columns are the different number segments as
169 described in the partition
1 of the above enumeration. These cells identify
170 individual test cases by a number. An
\xmark in the cell indicates that this
171 test case can not be created as it is not possible with that number of segments
172 (eg. sending segments out of order when the number of segments is
1).
176 \newcommand{\doTCC}{\theTCC \stepcounter{TCC
}}
179 \begin{tabular
}{|l|l|l|l|l|l||l|l|l|l|
}
181 &
\multicolumn{9}{c|
}{\textbf{Partition
}}\\
183 &
4 &
5 &
3 &
6 &
2 &
1a &
1b &
1c &
1d\\
185 \multirow{9}{*
}{Instance
}
186 & a & a & a & a & a &
\doTCC &
\doTCC &
\doTCC &
\doTCC\\
187 & a & b & b & c & b &
\xmark &
\xmark &
\doTCC &
\doTCC\\
188 & c & a & b & a & b &
\xmark &
\xmark &
\doTCC &
\doTCC\\
189 & c & b & a & c & a &
\xmark &
\xmark &
\doTCC &
\doTCC\\
190 & b & a & b & c & a &
\xmark &
\xmark &
\doTCC &
\doTCC\\
191 & b & b & a & b & b &
\xmark &
\xmark &
\doTCC &
\doTCC\\
192 & c & b & b & a & b &
\xmark &
\doTCC &
\doTCC &
\doTCC\\
193 & b & b & b & a & b &
\xmark &
\doTCC &
\doTCC &
\doTCC\\
194 & a & b & b & b & a &
\xmark &
\xmark &
\doTCC &
\doTCC\\
197 \caption{Combinations of test cases
}
198 \label{table:testpairs
}
201 \subsection{Quality, completeness and coverage of tests
}
203 The network packets used in testing are constructed from prerecorded, known to
204 be correct, network traffic. These packets are then modified with well used and
205 field tested tools. Due to this the chance of errors in the test cases is quite
206 low. However, no formal proof of correctness of the test cases is present, this
207 means that any defects found might not be the result of a fault in the SUT.
208 Therefore detected defects should only indicate there is a high chance that
209 there is a fault in the SUT and can not result directly in the conclusion that
210 there actually is one.
214 Due to the nature of black-box testing coverage of the code in the
215 implementation of the SUT is unknown. However completeness of the tests over
216 the specification of the SUT can be assessed.
220 Due to the clear and exhaustive specification of TCP the completeness of the
221 test suite can be clearly assessed.
223 As always, $
100\%$ completeness is not feasible, therefore test cases are
224 carefully selected to cover the most interesting parts of the TCP specification
225 to ensure a complete but feasible test suite.
227 To further increase the coverage of the test suites tests are randomized. The
228 tests which test the handling of
\emph{bit errors
}, changes in the
\emph{packet
229 order
} and
\emph{dropped packets
} randomize where they introduce an error. The
230 test suite runs these tests multiple times to increase the likelihood that they
231 discover a fault which is only present when an error occurs in a certain
234 To further decrease the number of tests needed test cases are divided into
235 equivalence partitions and the combination of cases as described in
236 Table~
\ref{table:testpairs
} ensures that all partitions are
237 covered and the number of individual tests is still feasible.
241 % wat ik ook probeer ik krijg de eerste collum
242 % zijn tekst niet verticaal gecentered
246 \subsection{Test cases
}
248 Before every test case use the following steps to initialize the testing environment.
251 \item Boot the vm using VirtualBox.
252 \item Setup iptables by executing
\texttt{\# code/iptables.sh
}
253 \item Navigate to the working directory by running
\texttt{\$ cd /home/student/tt2015
}
254 \item Start the echo server by running
\texttt{\# cd code/server \&\& java Main
}
257 \begin{longtable
}{|p
{.2\linewidth}|p
{.8\linewidth}|
}
260 Title & Single valid request with
1byte payload. \\
\hline
261 Input & Generated packets. \\
\hline
262 Expected output & Packets echoed back by Echo-Server. \\
\hline
263 \multirow{2}{*
}{Course of action
}
264 &
1. Use the steps listed above in order to start the SUT. \\
265 &
2. Execute the script by running
\texttt{\# code/client/tests/
1.py
} \\
\hline
266 Valid trace & Verify that the script prints 'Success'. \\
\hline
270 Title & Single valid request with
65495bytes payload. \\
\hline
271 Input & Generated packets. \\
\hline
272 Expected output & Packets echoed back by Echo-Server. \\
\hline
273 \multirow{2}{*
}{Course of action
}
274 &
1. Use the steps listed above in order to start the SUT. \\
275 &
2. Execute the script by running
\texttt{\# code/client/tests/
2.py
} \\
\hline
276 Valid trace & Verify that the script prints 'Success'. \\
\hline
280 Title &
5 valid requests with
1byte payload. \\
\hline
281 Input & Generated packets. \\
\hline
282 Expected output & Packets echoed back by Echo-Server, in the same order as the client sent them. \\
\hline
283 \multirow{2}{*
}{Course of action
}
284 &
1. Use the steps listed above in order to start the SUT. \\
285 &
2. Execute the script by running
\texttt{\# code/client/tests/
3.py
} \\
\hline
286 Valid trace & Verify that the script prints 'Success'. \\
\hline
290 Title &
5 valid requests with
65495bytes payload. \\
\hline
291 Input & Generated packets with
65495bytes payload. \\
\hline
292 Expected output & Packets echoed back by Echo-Server, in the same order as the client sent them. \\
\hline
293 \multirow{2}{*
}{Course of action
}
294 &
1. Use the steps listed above in order to start the SUT. \\
295 &
2. Execute the script by running
\texttt{\# code/client/tests/
4.py
} \\
\hline
296 Valid trace & Verify that the script prints 'Success'. \\
\hline
300 Title &
5 valid requests with
1byte payload sent out of order. \\
\hline
301 Input & Generated packets with
1byte payload, two packets are swapped in position. \\
\hline
302 Expected output & All requests sent up to and including
303 the swapped packet with the lowest sequence number, the remaining packets are dropped. \\
\hline
304 \multirow{2}{*
}{Course of action
}
305 &
1. Use the steps listed above in order to start the SUT. \\
306 &
2. Execute the script by running
\texttt{\# code/client/tests/
5.py
} \\
\hline
307 Valid trace & Verify that the script prints 'Success'. \\
\hline
311 %\begin{tabularx}{\linewidth}{| l | X|}
314 %Title & Single valid request. \\\hline
315 %Input & Pcap file with prerecorded valid packets. \\\hline
316 %Expected output & Pcap file with valid response to request. \\\hline
317 %Course of action & \begin{enumerate}
318 % \item Execute \emph{./scripts/tests/case1-single-valid.sh}
319 % \item Load \emph{output/case1.pcap} with ...
320 %\end{enumerate} \\\hline
321 %Valid trace & \begin{enumerate}
322 % \item \textbf{Hier packets benoemen?}
323 %\end{enumerate} \\\hline
326 %\begin{tabularx}{\linewidth}{| l | X|}
329 %Title & Single request with corrupted checksum. \\\hline
330 % Input & Pcap file used as \emph{test-case 1} input. \\\hline
331 % Expected output & No response from SUT, logs with rejected packets. \\\hline
332 % Course of action & \begin{enumerate}
333 % \item Load input pcap file into ....
334 % \item Corrupt checksum of loaded packets.
335 % \item Save resulting packets as pcap file.
336 % \item Load new pcap file into ...
337 % \item Replay new pcap file.
338 % \item Record SUT response using...
339 % \item Extract log with rejected packets.
340 % \item Save recorded packets as a pcap file.
341 % \item Analyze packets in resulting file.
342 % \end{enumerate} \\\hline
343 % Valid trace & \begin{enumerate}
344 % \item \textbf{Aangeven welke packets corrupted zijn?}
345 % \end{enumerate} \\\hline