a2/1cases.tex

   1 \subsection{Preflight checklist}
   2 Before actual certification is commenced we perform a manual test using a
   3 checklist.
   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
   8 user permissions.
   9
  10 \begin{longtable}{|l|rp{.8\linewidth}|}
  11         \hline
  12         Check 1 & \multicolumn{2}{l|}{Get the SUT in a workable state.}\\
  13         \hline
  14         \multirow{3}{*}{Course of action}
  15                 & 1. & Import the VirtualBox image into VirtualBox.\\
  16                 & 2. & Boot the vm.\\
  17                 & 3. & Verify the SUT booted successfully and the network modules are
  18                 loaded.\\
  19         \hline
  20         Passed & \multicolumn{2}{l|}{\textit{Yes/No}}\\
  21         \hline\hline
  22         Check 2 & \multicolumn{2}{l|}{Verify the SUT is complete.}\\
  23         \hline
  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
  31                         \texttt{\$ scapy}.\\
  32                 & 5. & Verify all scripts used for testing are present on the system.\\
  33         \hline
  34         Passed & \multicolumn{2}{l|}{\textit{Yes/No}}\\
  35         \hline\hline
  36         Check 3 & \multicolumn{2}{l|}{Initialize the testing environment..}\\
  37         \hline
  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}\\
  51         \hline
  52         Passed & \multicolumn{2}{l|}{\textit{Yes/No}}\\
  53         \hline\hline
  54         Check 4 & \multicolumn{2}{l|}{Test the tool environment.}\\
  55         \hline
  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.\\
  61         \hline
  62         Passed & \multicolumn{2}{l|}{\textit{Yes/No}}\\
  63         \hline\hline
  64         Check 5 & \multicolumn{2}{l|}{All test inputs and scripts are present.}\\
  65         \hline
  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}\\
  70         \hline
  71         Passed & \multicolumn{2}{l|}{\textit{Yes/No}}\\
  72         \hline
  73         \caption{Preflight checklist\label{tbl:preflight}}
  74 \end{longtable}
  75
  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.
  82
  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
  87 specification.
  88
  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.
  92
  93 \begin{enumerate}
  94         \item \emph{Number of segments} in request~\footnote{A request is
  95                 considered establishing a connection (handshake) and a number of
  96                 payload segments}
  97                 \begin{enumerate}
  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)
 102                 \end{enumerate}
 103         \item \emph{source port}
 104                 \begin{enumerate}
 105                         \item Correct
 106                         \item Incorrect
 107                 \end{enumerate}
 108         \item \emph{destination port}
 109                 \begin{enumerate}
 110                         \item Correct
 111                         \item Incorrect
 112                 \end{enumerate}
 113         \item Bit errors in \emph{payload}
 114                 \begin{enumerate}
 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
 118                 \end{enumerate}
 119         \item \emph{checksum}
 120                 \begin{enumerate}
 121                         \item Correct
 122                         \item Incorrect
 123                 \end{enumerate}
 124         \item \emph{Segment order}
 125                 \begin{enumerate}
 126                         \item Correct
 127                         \item Out of order
 128                         \item Missing Segments
 129                 \end{enumerate}
 130 \end{enumerate}
 131
 132 These partitions were chosen since they correspond to key parts of the TCP
 133 specification.
 134
 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.
 138
 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.
 142
 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
 147 of one word
 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
 150 of bit errors occur.
 151
 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).
 159
 160 \bigskip
 161
 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.
 165
 166 This is expressed in Table~\ref{tbl: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).
 173
 174 \setcounter{TCC}{1}
 175 \begin{table}[H]
 176         \centering
 177         \begin{tabular}{|l|l|l|l|l|l||l|l|l|l|}
 178                 \hline
 179                 & \multicolumn{9}{c|}{\textbf{Partition}}\\
 180                 \hline
 181                 & 4 & 5 & 3 & 6 & 2 & 1a & 1b & 1c & 1d\\
 182                 \hline\hline
 183                 \multirow{9}{*}{Instance}
 184                 & a & a & a & a & a & \doTCC & \doTCC & \doTCC & \doTCC\\
 185                 & a & b & b & c & b & \xmark & \xmark & \doTCC & \doTCC\\
 186                 & c & a & b & a & b & \xmark & \xmark & \doTCC & \doTCC\\
 187                 & c & b & a & c & a & \xmark & \xmark & \doTCC & \doTCC\\
 188                 & b & a & b & c & a & \xmark & \xmark & \doTCC & \doTCC\\
 189                 & b & b & a & b & b & \xmark & \xmark & \doTCC & \doTCC\\
 190                 & c & b & b & a & b & \xmark & \doTCC & \doTCC & \doTCC\\
 191                 & b & b & b & a & b & \xmark & \doTCC & \doTCC & \doTCC\\
 192                 & a & b & b & b & a & \xmark & \xmark & \doTCC & \doTCC\\
 193                 \hline
 194         \end{tabular}
 195 \caption{Combinations of test cases}
 196 \label{tbl:testpairs}
 197 \end{table}
 198
 199 \subsection{Quality, completeness and coverage of tests}
 200
 201 The network packets used in testing are constructed from prerecorded, known to
 202 be correct, network traffic. These packets are then modified with well used and
 203 field tested tools. Due to this the chance of errors in the test cases is quite
 204 low. However, no formal proof of correctness of the test cases is present, this
 205 means that any defects found might not be the result of a fault in the SUT.
 206 Therefore detected defects should only indicate there is a high chance that
 207 there is a fault in the SUT and can not result directly in the conclusion that
 208 there actually is one.
 209
 210 \bigskip
 211
 212 Due to the nature of black-box testing coverage of the code in the
 213 implementation of the SUT is unknown. However completeness of the tests over
 214 the specification of the SUT can be assessed.
 215
 216 \bigskip
 217
 218 Due to the clear and exhaustive specification of TCP the completeness of the
 219 test suite can be clearly assessed.
 220
 221 As always, $100\%$ completeness is not feasible, therefore test cases are
 222 carefully selected to cover the most interesting parts of the TCP specification
 223 to ensure a complete but feasible test suite.
 224
 225 To further increase the coverage of the test suites tests are randomized. The
 226 tests which test the handling of \emph{bit errors}, changes in the \emph{packet
 227 order} and \emph{dropped packets} randomize where they introduce an error. The
 228 test suite runs these tests multiple times to increase the likelihood that they
 229 discover a fault which is only present when an error occurs in a certain
 230 position.
 231
 232 To further decrease the number of tests needed test cases are divided into
 233 equivalence partitions and the combination of cases as described in
 234 Table~\ref{tbl:testpairs} ensures that all partitions are
 235 covered and the number of individual tests is still feasible.
 236
 237
 238 %
 239 % wat ik ook probeer ik krijg de eerste collum
 240 % zijn tekst niet verticaal gecentered
 241 %
 242
 243
 244 \subsection{Test suite}
 245
 246 Before executing the test suite the test environment has to be initialized.
 247
 248 \begin{enumerate}
 249         \item Boot the vm using VirtualBox.
 250         \item Setup iptables by executing \texttt{\# code/iptables.sh}
 251         \item Navigate to the working directory by running
 252                 \texttt{\$ cd /home/student/tt2015}
 253         \item Start the echo server by running
 254                 \texttt{\# cd code/server \&\& Java Main}
 255 \end{enumerate}
 256
 257 \subsubsection{Preflight checks}
 258 The we do the preflight checks as defined in Table~\ref{tbl:preflight}.
 259
 260 \subsubsection{Test Cases}
 261 If the SUT passes the preflight checks the actual test cases can be executed.
 262 Table~\ref{tbl:testcases} shows the expected results of each of the test cases
 263 described in Table~\ref{table:testpairs}.
 264
 265 \setcounter{TCC}{1}
 266 \begin{table}[H]
 267         \centering
 268     \begin{tabular}{|l|p{.7\linewidth}|}
 269         \hline
 270         Test number & Expected results\\
 271         \hline\hline
 272         \doTCC & An ACK\# of the send sequence number + 1.\\  \hline
 273         \doTCC & An ACK\# of the sequence number of the last send segment + the
 274                 size of the payload of that segment.\\  \hline
 275         \doTCC & An ACK\# of the sequence number of the last send segment + the
 276                 size of the payload of that segment.\\  \hline
 277         \doTCC & An ACK\# of the sequence number of the last send segment + the
 278                 size of the payload of that segment.\\  \hline
 279         \doTCC & The ACK\# for the SEQ\# of the first segments which is
 280                 corrupted is received for each consecutive segment send.\\
 281         $\vdots$ & \\
 282         \setcounter{TCC}{14}
 283         \doTCC & The ACK\# for the SEQ\# of the first segments which is
 284                 corrupted is received for each consecutive segment send.\\  \hline
 285         \doTCC & The segment is not attributed to the current connection
 286                 and therefore no ACK\# is received. \\  \hline
 287         \doTCC & The ACK\# for the SEQ\# of the first segments which is
 288                 corrupted is received for each consecutive segment send.\\  \hline
 289         \doTCC & The ACK\# for the SEQ\# of the first segments which is
 290                 corrupted is received for each consecutive segment send.\\  \hline
 291         \doTCC & The segment is not attributed to the current connection
 292                 and therefore no ACK\# is received. \\  \hline
 293         \doTCC & The ACK\# for the SEQ\# of the first segments which is
 294                 corrupted is received for each consecutive segment send.\\  \hline
 295         \doTCC & The ACK\# for the SEQ\# of the first segments which is
 296                 corrupted is received for each consecutive segment send.\\ \hline
 297         \doTCC & The ACK\# for the SEQ\# of the first segments which is
 298                 corrupted is received for each consecutive segment send.\\  \hline
 299         \doTCC & The ACK\# for the SEQ\# of the first segments which is
 300                 corrupted is received for each consecutive segment send.\\ \hline
 301         \hline
 302     \end{tabular}
 303 \caption{Expected results of test cases}
 304 \label{table:preflightresults}
 305 \end{table}
 306
 307 % Bij Ramons afwezigheid
 308 % Paul Vitero (linkerkant lange gang)
 309 % verdieping Mercator
 310
 311
 312 %\begin{longtable}{|p{.2\linewidth}|p{.8\linewidth}|}
 313         %\hline
 314         %Nr & 1 \\\hline
 315         %Title & Single valid request with 1byte payload. \\\hline
 316         %Input & Generated packets. \\\hline
 317         %Expected output & Packets echoed back by Echo-Server. \\\hline
 318         %\multirow{2}{*}{Course of action}
 319  %& 1. Use the steps listed above in order to start the SUT. \\
 320  %& 2. Execute the script by running \texttt{\# code/client/tests/1.py} \\\hline
 321         %Valid trace & Verify that the script prints 'Success'. \\\hline
 322         %\hline
 323 %
 324         %Nr & 2 \\\hline
 325         %Title & Single valid request with 65495bytes payload. \\\hline
 326         %Input & Generated packets. \\\hline
 327         %Expected output & Packets echoed back by Echo-Server. \\\hline
 328         %\multirow{2}{*}{Course of action}
 329         %& 1. Use the steps listed above in order to start the SUT. \\
 330         %& 2. Execute the script by running \texttt{\# code/client/tests/2.py} \\\hline
 331         %Valid trace & Verify that the script prints 'Success'. \\\hline
 332         %\hline
 333 %
 334         %Nr & 3 \\\hline
 335         %Title & 5 valid requests with 1byte payload. \\\hline
 336         %Input & Generated packets. \\\hline
 337         %Expected output & Packets echoed back by Echo-Server, in the same order as the client sent them. \\\hline
 338         %\multirow{2}{*}{Course of action}
 339         %& 1. Use the steps listed above in order to start the SUT. \\
 340         %& 2. Execute the script by running \texttt{\# code/client/tests/3.py} \\\hline
 341         %Valid trace & Verify that the script prints 'Success'. \\\hline
 342         %\hline
 343 %
 344         %Nr & 4 \\\hline
 345         %Title & 5 valid requests with 65495bytes payload. \\\hline
 346         %Input & Generated packets with 65495bytes payload. \\\hline
 347         %Expected output & Packets echoed back by Echo-Server, in the same order as the client sent them. \\\hline
 348         %\multirow{2}{*}{Course of action}
 349         %& 1. Use the steps listed above in order to start the SUT. \\
 350         %& 2. Execute the script by running \texttt{\# code/client/tests/4.py} \\\hline
 351         %Valid trace & Verify that the script prints 'Success'. \\\hline
 352         %\hline
 353 %
 354         %Nr & 5 \\\hline
 355         %Title & 5 valid requests with 1byte payload sent out of order. \\\hline
 356         %Input & Generated packets with 1byte payload, two packets are swapped in position. \\\hline
 357         %Expected output & All requests sent up to and including
 358          %the swapped packet with the lowest sequence number, the remaining packets are dropped. \\\hline
 359         %\multirow{2}{*}{Course of action}
 360         %& 1. Use the steps listed above in order to start the SUT. \\
 361         %& 2. Execute the script by running \texttt{\# code/client/tests/5.py} \\\hline
 362         %Valid trace & Verify that the script prints 'Success'. \\\hline
 363         %\hline
 364 %
 365         %Nr & 6 \\\hline
 366         %Title & Request with corrupted source port. \\\hline
 367         %Input & Generated packets with 1byte payload, in these packets the source port number is increased by one. \\\hline
 368         %Expected output & - \\\hline
 369         %\multirow{2}{*}{Course of action}
 370         %& 1. Use the steps listed above in order to start the SUT. \\
 371         %& 2. Execute the script by running \texttt{\# code/client/tests/6.py} \\\hline
 372         %Valid trace & Verify that the script prints 'Success'. \\\hline
 373         %\hline
 374 %
 375 %
 376         %Nr & 6 \\\hline
 377         %Title & Request with corrupted destination port. \\\hline
 378         %Input & Generated packets with 1byte payload, in these packets the destination port number is increased by one. \\\hline
 379         %Expected output & - \\\hline
 380         %\multirow{2}{*}{Course of action}
 381         %& 1. Use the steps listed above in order to start the SUT. \\
 382         %& 2. Execute the script by running \texttt{\# code/client/tests/6.py} \\\hline
 383         %Valid trace & Verify that the script prints 'Success'. \\\hline
 384         %\hline
 385 %
 386 %\end{longtable}
 387
 388 %\begin{tabularx}{\linewidth}{| l | X|}
 389 %\hline
 390 %Nr & 1 \\\hline
 391 %Title & Single valid request. \\\hline
 392 %Input & Pcap file with prerecorded valid packets. \\\hline
 393 %Expected output & Pcap file with valid response to request. \\\hline
 394 %Course of action & \begin{enumerate}
 395 %       \item Execute \emph{./scripts/tests/case1-single-valid.sh}
 396 %       \item Load \emph{output/case1.pcap} with ...
 397 %\end{enumerate} \\\hline
 398 %Valid trace & \begin{enumerate}
 399 %       \item \textbf{Hier packets benoemen?}
 400 %\end{enumerate} \\\hline
 401 %\end{tabularx}
 402 %
 403 %\begin{tabularx}{\linewidth}{| l | X|}
 404 %       \hline
 405 %       Nr & 2 \\\hline
 406 %Title & Single request with corrupted checksum. \\\hline
 407 %       Input & Pcap file used as \emph{test-case 1} input. \\\hline
 408 %       Expected output & No response from SUT, logs with rejected packets. \\\hline
 409 %       Course of action & \begin{enumerate}
 410 %               \item Load input pcap file into ....
 411 %               \item Corrupt checksum of loaded packets.
 412 %               \item Save resulting packets as pcap file.
 413 %               \item Load new pcap file into ...
 414 %               \item Replay new pcap file.
 415 %               \item Record SUT response using...
 416 %               \item Extract log with rejected packets.
 417 %               \item Save recorded packets as a pcap file.
 418 %               \item Analyze packets in resulting file.
 419 %       \end{enumerate} \\\hline
 420 %       Valid trace & \begin{enumerate}
 421 %               \item \textbf{Aangeven welke packets corrupted zijn?}
 422 %       \end{enumerate} \\\hline
 423 %\end{tabularx}
 424 %\end{table}