Plugin monitoring

plugin development monitoring

Introduction

As detailed in monitoring mode tutorial, T2 can either be remotely controlled by USR1/2 signals or by the t2stat command. Each plugin can implement a monitoring function which will be called during monitoring or report operation.

Getting started

Create folders for your data and results

If you have not created a separate data and results directory yet, please do it now. This will greatly facilitate your workflow:

mkdir ~/data ~/results

Reset tranalyzer2 and the plugins configuration

If you have followed the other tutorials, you may have modified some of the core and plugins configuration. To ensure your results match those in this tutorial, make sure to reset everything:

t2conf -a --reset

You can also clean all build files:

t2build -a -c

Empty the plugin folder

To ensure we are not left with some unneeded plugins or plugins which were built using different core configuration, it is safer to empty the plugins folder:

t2build -e -y

Are you sure you want to empty the plugin folder '/home/user/.tranalyzer/plugins' (y/N)? yes
Plugin folder emptied

Download the PCAP file

The PCAP file used in this tutorial can be downloaded here:

Please save it in your ~/data folder:

wget --no-check-certificate -P ~/data https://tranalyzer.com/download/data/annoloc2.pcap

Configure Tranalyzer2 core

For this tutorial, we need to activate the monitoring mode using PCAP time. We want to produce a differential machine report. All the required flags reside in main.h:

  • tranalyzer2/src/main.h

    • MONINTTMPCP=1 (monitoring mode using PCAP time)
    • DIFF_REPORT=1 (differential report)
    • MACHINE_REPORT=1 (machine report)

Change the configuration of Tranalyzer2 using the following t2conf command:

t2conf tranalyzer2 -D MONINTTMPCP=1 -D DIFF_REPORT=1 -D MACHINE_REPORT=1

Build tranalyzer2 and the required plugins

For this tutorial, we will need to build the core (tranalyzer2) and the following plugin:

We do not need flow output, so no sink plugin is needed.

As you may have modified some of the automatically generated files, it is safer to use the -r and -f options.

t2build -r -f tranalyzer2 tcpStates

...

BUILDING SUCCESSFUL

Source code

In this tutorial, we will extend tcpWin03.tar.gz, the final version of the previous tutorial (Plugin end report).

If you are impatient, you can download the intermediate and final versions of the tcpWin plugin we will develop in this tutorial.

To use one of those plugins, just unpack it in the plugins folder of your T2 installation.

tranpl

tar -xf ~/Downloads/tcpWin05.tar.gz

And let t2_aliases know about it:

source "$T2HOME/scripts/t2_aliases"

Implementing the monitoring

If your plugin wants to contribute information to the monitoring mode, then global variables and a void t2Monitoring(FILE *stream, uint8_t state) callback have to be added.

So open tcpWin.c and add two global variables after the tcpWinFlows definition. Look for the // <-- markers below. If you already completed the end report tutorial, you only need to add the winStatG0 variable, which will be used in the differential mode to store the old value of winStatG. If this is your first plugin just add both variables: winStatG and winStatG0. Note that if you use one of the T2_LOG*_DIFF*() macro, then variables MUST always follow this naming convention: variable name for old value = variable name for current value suffixed with 0, e.g., static uint8_t myVar, myVar0;.

tcpWin

vi src/tcpWin.c

...

/*
 * Plugin variables that may be used by other plugins (MUST be declared in
 * the header file as 'extern tcpWinFlow_t *tcpWinFlows;'
 */

tcpWinFlow_t *tcpWinFlows;


/*
 * Static variables are only visible in this file
 */

static uint32_t pktTcpCnt;              // Aggregated TCP packet count
static uint32_t winThCntG, winThCntG0;  // <-- Aggregated win threshold count and variable for the last threshold count
static uint8_t tcpWinStat;              // <-- Aggregated status
...

Then in the t2OnFlowTerminate(...) callback, add the lines marked by // <-- to aggregate tcpWinStat and winThCnt of all flows, if you did not do the end report tutorial. Here we aggregate all flow information into global variables.

vi src/tcpWin.c

...
void t2OnFlowTerminate(unsigned long flowIndex, outputBuffer_t *buf) {
    tcpWinFlow_t * const tcpWinFlowP = &tcpWinFlows[flowIndex];

    tcpWinStat |= tcpWinFlowP->stat;        // <-- Aggregate all packet flags
    pktTcpCnt  += tcpWinFlowP->pktTcpCnt;   // Count all TCP packets
    winThCntG  += tcpWinFlowP->winThCnt;    // <-- Sum all winThCnt packet counts

    OUTBUF_APPEND_U8(buf, tcpWinFlowP->stat);
    OUTBUF_APPEND_U8(buf, tcpWinFlowP->ttl);
    OUTBUF_APPEND_U32(buf, tcpWinFlowP->tcpWinInit);
    OUTBUF_APPEND_U32(buf, tcpWinFlowP->winThCnt);

    float f = 0.0;
    if (tcpWinFlowP->pktTcpCnt) f = (float)tcpWinFlowP->winThCnt/(float)tcpWinFlowP->pktTcpCnt;

    OUTBUF_APPEND_FLT(buf, f);
}
...

Note, that a snapshot taken by the monitoring is now only representing the terminated flows not the actually existing state in the memory. If you want that, you need to shift that code, a bit modified into the t2OnLayer4(...) callback. We will try that later.

Implementing the t2Monitoring() callback

Now add the void t2Monitoring(FILE *stream, uint8_t state) callback after the t2OnFlowTerminate(...) callback (or after the t2PluginReport(...) callback if you implemented the end report already).

The t2Monitoring(...) function is called by the core:

  • At T2 initialization: T2_MON_PRI_HDR for the machine mode to output header information.
  • At a USR1/2 interrupt: T2_MON_PRI_VAL to print data in the machine mode and T2_MON_PRI_REPORT for the report mode.

Note the DIFF_REPORT pragma, which implements the backup of the old winThCntG value.

If one case is not implemented, nothing will appear.

vi src/tcpWin.c

...

/*
 * This function is used to report information regarding the plugin
 * at regular interval or when a USR1 signal is received.
 */
void t2Monitoring(FILE *stream, uint8_t state) {

    switch (state) {

        // Print the name of the variables that will be output
        case T2_MON_PRI_HDR: // hdr output at the beginning
            fputs("winPktThCnt" SEP_CHR, stream); // Note the trailing separator (SEP_CHR)
            return;

        // Print the variables to monitor
        case T2_MON_PRI_VAL: // USR1/2 interrupt machine mode
            // Note the trailing separator (SEP_CHR)
            fprintf(stream, "%" PRIu32 /* winPktThCnt */ SEP_CHR, winThCntG - winThCntG0);
            break;

        // Print a report similar to t2PluginReport()
        case T2_MON_PRI_REPORT: // USR1/2 interrupt report mode
            T2_FPLOG_DIFFNUMP(stream, plugin_name,
                    "Number of TCP winsize packets below threshold" STR(TCPWIN_THRES),
                    winThCntG, numPackets);
            break;

        default:  // Invalid state, do nothing
            return;
    }

#if DIFF_REPORT == 1
    winThCntG0 = winThCntG; // differential mode, save the old value
#endif // DIFF_REPORT == 1
}

...

After you edited the skeleton code you should compare your implementation with tcpWin04.tar.gz.

Now compile tcpWin.

t2build tcpWin

If compilation was error free, execute T2 with the -l option to redirect all end report info to the file ~/results/annoloc2_log.txt.

t2 -r ~/data/annoloc2.pcap -l -w ~/results/

%repTyp   time                dur          memUsageKB  fillSzHashMap  numFlows  numAFlows  numBFlows  numPkts  numAPkts  numBPkts  numV4Pkts  numV6Pkts  numVxPkts  numBytes  numABytes  numBBytes  numFrgV4Pkts  numFrgV6Pkts  numAlarms  rawBandwidth  globalWarn          0x0042Pkts  0x0042Bytes  0x00fePkts  0x00feBytes  0x0806Pkts  0x0806Bytes  0x8035Pkts  0x8035Bytes  0x0800Pkts  0x0800Bytes  0x86ddPkts  0x86ddBytes  ICMPPkts  ICMPBytes  IGMPPkts  IGMPBytes  TCPPkts  TCPBytes  UDPPkts  UDPBytes  GREPkts  GREBytes  ICMPv6Pkts  ICMPv6Bytes  SCTPPkts  SCTPBytes  winPktThCnt
USR1MR_D  1022171702.125000   0.308953000  18857       2144           2152      1220       932        14548    6878      7670      14542      3          0          765516    358988     406528     31            0             0          262155.094    0x0c00881a0202c044  0           0            0           0            3           126          0           0            14542       765256       3           134          34        2220       0         0          11316    628896    3192     134172    0        0         0           0            0         0          5
USR1MR_D  1022171703.027000   0.999902000  2039        1735           1770      963        807        49194    22820     26374     49162      22         0          2586276   1191528    1394748    97            0             0          270888.438    0x0c00987a0202c044  0           0            0           0            10          420          0           0            49162       2584404      22          1452         129       7938       0         0          37923    2109222   11132    468696    0        0         0           0            0         0          23
USR1MR_D  1022171704.334000   1.307000     848         1069           1131      650        481        48765    22660     26105     48734      26         0          2562726   1182212    1380514    91            0             0          267914.906    0x0c00987a0202c044  0           0            0           0            5           210          0           0            48734       2560800      26          1716         133       8202       0         0          37502    2085364   11125    468950    0        0         0           0            0         0          39
USR1MR_D  1022171705.030000   0.999696000  574         757            833       489        344        47156    22079     25077     47146      2          0          2471500   1148578    1322922    91            0             0          253765.031    0x0c00987a0202c044  0           0            0           0            8           336          0           0            47146       2471064      2           100          124       7704       0         0          36153    2006038   10870    457388    0        0         0           0            0         0          43
USR1MR_D  1022171706.009000   0.999979000  528         618            687       384        303        47251    21942     25309     47239      3          0          2480982   1143508    1337474    96            0             0          257045.938    0x0c00987a0202c044  0           0            0           0            9           378          0           0            47239       2480442      3           162          139       8814       0         0          36192    2013364   10909    458330    0        0         1           62           0         0          52
USR1MR_D  1022171707.298000   1.289000     488         628            714       396        318        48061    22155     25906     48038      5          0          2520286   1153038    1367248    71            0             0          263887.188    0x0c00987a0202d044  0           0            0           0            18          756          0           0            48038       2519208      5           322          112       7032       0         0          37267    2064558   10657    447646    5        170       2           124          0         0          47
USR1MR_D  1022171708.102000   0.999804000  467         559            622       339        283        48284    22114     26170     48262      3          0          2539600   1155564    1384036    79            0             0          266056.719    0x0c00987a0202d044  0           0            0           0            19          798          0           0            48262       2538612      3           190          117       7458       0         0          37526    2084196   10619    446990    1        34        2           124          0         0          37
USR1MR_D  1022171709.695000   1.593000     335         527            598       351        247        49272    22973     26299     49249      7          0          2587936   1198894    1389042    96            0             0          270947.375    0x0c00987a0202d044  0           0            0           0            16          672          0           0            49249       2586870      7           394          143       8910       0         0          38179    2117206   10931    461018    0        0         1           62           0         0          58
USR1MR_D  1022171710.175000   0.999480000  476         528            583       323        260        50508    23624     26884     50497      4          0          2662064   1237564    1424500    97            0             0          282688.781    0x0c00987a0202d044  0           0            0           0            7           294          0           0            50497       2661506      4           264          109       6738       0         0          39825    2209682   10560    445112    7        238       0           0            0         0          28
USR1MR_D  1022171711.193000   1.018000     307         474            524       306        218        48619    22823     25796     48603      2          0          2563366   1196706    1366660    84            0             0          272032.375    0x0c00987a0202d044  0           0            0           0            14          588          0           0            48603       2562646      2           132          113       7122       0         0          38302    2125628   10189    429994    0        0         0           0            0         0          28
USR1MR_D  1022171712.691000   1.498000     307         535            574       332        242        49611    23075     26536     49599      0          0          2603054   1202538    1400516    95            0             0          277082.562    0x0c00987a0202d044  0           0            0           0            12          504          0           0            49599       2602550      0           0            134       8508       0         0          38673    2139862   10792    454180    0        0         0           0            0         0          23
USR1MR_D  1022171713.000000   0.999309000  340         447            529       293        236        50143    23468     26675     50134      0          0          2631530   1223992    1407538    96            0             0          278520.219    0x0c00987a0202d044  0           0            0           0            9           378          0           0            50134       2631152      0           0            113       7050       0         0          39099    2164110   10922    459992    0        0         0           0            0         0          24
USR1MR_D  1022171714.741000   1.741000     278         380            499       287        212        47899    22509     25390     47873      17         0          2514274   1172650    1341624    94            0             0          263678.375    0x0c00987a0202d044  0           0            0           0            9           378          0           0            47873       2512870      17          1026         115       7278       1         38         37075    2056666   10696    449812    0        0         0           0            0         0          35
USR1MR_D  1022171715.263000   0.999522000  258         378            477       275        202        49110    22878     26232     49096      3          0          2582484   1195104    1387380    89            0             0          272797.156    0x0c00987a0202d044  0           0            0           0            11          462          0           0            49096       2581824      3           198          130       8052       1         38         38284    2123868   10684    450064    0        0         0           0            0         0          46
USR1MR_D  1022171716.269000   1.006000     332         471            543       316        227        49985    23187     26798     49976      4          0          2627906   1210650    1417256    94            0             0          278140.844    0x0c00987a0202d044  0           0            0           0            5           210          0           0            49976       2627432      4           264          128       8064       0         0          39083    2166434   10769    453198    0        0         0           0            0         0          25
USR1MR_D  1022171717.932000   1.663000     291         386            500       286        214        48938    22518     26420     48921      6          0          2575532   1178164    1397368    93            0             0          273963.812    0x0c00987a0202d044  0           0            0           0            11          462          0           0            48921       2574738      6           332          130       8148       0         0          38233    2122014   10562    444840    0        0         0           0            0         0          29
USR1MR_D  1022171718.200000   0.999268000  197         309            427       240        187        47700    21873     25827     47675      21         0          2501292   1138298    1362994    88            0             0          263612.438    0x0c00987a0202d044  0           0            0           0            4           168          0           0            47675       2499750      21          1374         121       7530       0         0          37041    2050350   10528    442956    3        102       3           186          0         0          34
USR1MR_D  1022171719.284000   1.084000     262         374            472       286        186        48263    21982     26281     48249      2          0          2532294   1143108    1389186    97            0             0          268193.375    0x0c00987a0202d044  0           0            0           0            12          504          0           0            48249       2531690      2           100          134       8532       0         0          37445    2074682   10671    448542    0        0         0           0            0         0          34
USR1MR_D  1022171720.1095000  1.811000     278         397            531       306        225        49621    22621     27000     49599      4          0          2611286   1179958    1431328    93            0             0          277837.719    0x0c00987a0202d044  0           0            0           0            18          756          0           0            49599       2610330      4           200          113       7074       0         0          39044    2164776   10444    438612    0        0         0           0            0         0          32
USR1MR_D  1022171721.640000   0.999545000  222         406            506       282        224        50166    22964     27202     50160      0          0          2639776   1198584    1441192    93            0             0          280237.719    0x0c00987a0222d044  0           0            0           0            6           252          0           0            50160       2639524      0           0            125       7746       0         0          39445    2186290   10590    445488    0        0         0           0            0         0          109
USR1MR_D  1022171722.427000   0.999787000  241         459            562       327        235        47175    21896     25279     47160      4          0          2478598   1140152    1338446    92            0             0          256399.453    0x0c00987a0222d044  0           0            0           0            11          462          0           0            47160       2477872      4           264          117       7458       0         0          36225    2015758   10822    454920    0        0         0           0            0         0          40
USR1MR_D  1022171723.058000   0.999631000  193         357            485       276        209        48872    22650     26222     48858      8          0          2578544   1187328    1391216    99            0             0          271465.625    0x0c00987a0222d044  0           0            0           0            6           252          0           0            48858       2577860      8           432          114       7260       0         0          38162    2124068   10587    446862    0        0         0           0            0         0          41
USR1MR_D  1022171724.127000   1.069000     213         412            575       321        254        50089    23028     27061     50080      3          0          2634246   1201068    1433178    88            0             0          281685.219    0x0c00987a0222d044  0           0            0           0            6           252          0           0            50080       2633832      3           162          107       6726       0         0          39264    2177144   10710    450028    0        0         1           62           0         0          55
USR1MR_D  1022171725.274000   1.147000     209         376            544       319        225        49908    22880     27028     49883      18         0          2627904   1195840    1432064    93            0             0          279872.562    0x0c00987a0222d044  0           0            0           0            7           294          0           0            49883       2626422      18          1188         139       8694       3         114        39002    2165132   10756    453636    0        0         0           0            0         0          63
USR1MR_D  1022171726.378000   1.104000     200         293            497       281        216        48767    22322     26445     48754      6          0          2565306   1165528    1399778    90            0             0          271439.000    0x0c00987a0222d044  0           0            0           0            7           294          0           0            48754       2564648      6           364          133       8394       5         190        37987    2109006   10634    447388    0        0         0           0            0         0          76

You will notice your monitoring column, winPktThCnt. Wasn’t so difficult, right?

Now remove tcpStates and rerun T2:

t2build -u tcpStates

Plugin 'tcpStates'


UNLOADING SUCCESSFUL

t2 -r ~/data/annoloc2.pcap -l -w ~/results/

%repTyp   time                dur          memUsageKB  fillSzHashMap  numFlows  numAFlows  numBFlows  numPkts  numAPkts  numBPkts  numV4Pkts  numV6Pkts  numVxPkts  numBytes  numABytes  numBBytes  numFrgV4Pkts  numFrgV6Pkts  numAlarms  rawBandwidth  globalWarn          0x0042Pkts  0x0042Bytes  0x00fePkts  0x00feBytes  0x0806Pkts  0x0806Bytes  0x8035Pkts  0x8035Bytes  0x0800Pkts  0x0800Bytes  0x86ddPkts  0x86ddBytes  ICMPPkts  ICMPBytes  IGMPPkts  IGMPBytes  TCPPkts  TCPBytes  UDPPkts  UDPBytes  GREPkts  GREBytes  ICMPv6Pkts  ICMPv6Bytes  SCTPPkts  SCTPBytes  winPktThCnt
USR1MR_D  1022171702.125000   0.308953000  18792       2152           2152      1220       932        14548    6878      7670      14542      3          0          765516    358988     406528     31            0             0          262155.094    0x0c00881a0202c044  0           0            0           0            3           126          0           0            14542       765256       3           134          34        2220       0         0          11316    628896    3192     134172    0        0         0           0            0         0          0
USR1MR_D  1022171703.027000   0.999902000  2003        1767           1767      961        806        49194    22820     26374     49162      22         0          2586276   1191528    1394748    97            0             0          270888.438    0x0c00987a0202c044  0           0            0           0            10          420          0           0            49162       2584404      22          1452         129       7938       0         0          37923    2109222   11132    468696    0        0         0           0            0         0          0
USR1MR_D  1022171704.334000   1.307000     836         1112           1112      639        473        48765    22660     26105     48734      26         0          2562726   1182212    1380514    91            0             0          267914.906    0x0c00987a0202c044  0           0            0           0            5           210          0           0            48734       2560800      26          1716         133       8202       0         0          37502    2085364   11125    468950    0        0         0           0            0         0          0
USR1MR_D  1022171705.030000   0.999696000  569         816            816       480        336        47156    22079     25077     47146      2          0          2471500   1148578    1322922    91            0             0          253765.031    0x0c00987a0202c044  0           0            0           0            8           336          0           0            47146       2471064      2           100          124       7704       0         0          36153    2006038   10870    457388    0        0         0           0            0         0          0
USR1MR_D  1022171706.009000   0.999979000  528         658            658       369        289        47251    21942     25309     47239      3          0          2480982   1143508    1337474    96            0             0          257045.938    0x0c00987a0202c044  0           0            0           0            9           378          0           0            47239       2480442      3           162          139       8814       0         0          36192    2013364   10909    458330    0        0         1           62           0         0          0
USR1MR_D  1022171707.298000   1.289000     488         685            685       381        304        48061    22155     25906     48038      5          0          2520286   1153038    1367248    71            0             0          263887.188    0x0c00987a0202d044  0           0            0           0            18          756          0           0            48038       2519208      5           322          112       7032       0         0          37267    2064558   10657    447646    5        170       2           124          0         0          0
USR1MR_D  1022171708.102000   0.999804000  454         595            595       325        270        48284    22114     26170     48262      3          0          2539600   1155564    1384036    79            0             0          266056.719    0x0c00987a0202d044  0           0            0           0            19          798          0           0            48262       2538612      3           190          117       7458       0         0          37526    2084196   10619    446990    1        34        2           124          0         0          0
USR1MR_D  1022171709.695000   1.593000     340         579            579       339        240        49272    22973     26299     49249      7          0          2587936   1198894    1389042    96            0             0          270947.375    0x0c00987a0202d044  0           0            0           0            16          672          0           0            49249       2586870      7           394          143       8910       0         0          38179    2117206   10931    461018    0        0         1           62           0         0          0
USR1MR_D  1022171710.175000   0.999480000  467         564            564       312        252        50508    23624     26884     50497      4          0          2662064   1237564    1424500    97            0             0          282688.781    0x0c00987a0202d044  0           0            0           0            7           294          0           0            50497       2661506      4           264          109       6738       0         0          39825    2209682   10560    445112    7        238       0           0            0         0          0
USR1MR_D  1022171711.193000   1.018000     312         516            516       302        214        48619    22823     25796     48603      2          0          2563366   1196706    1366660    84            0             0          272032.375    0x0c00987a0202d044  0           0            0           0            14          588          0           0            48603       2562646      2           132          113       7122       0         0          38302    2125628   10189    429994    0        0         0           0            0         0          0
USR1MR_D  1022171712.691000   1.498000     295         565            565       327        238        49611    23075     26536     49599      0          0          2603054   1202538    1400516    95            0             0          277082.562    0x0c00987a0202d044  0           0            0           0            12          504          0           0            49599       2602550      0           0            134       8508       0         0          38673    2139862   10792    454180    0        0         0           0            0         0          0
USR1MR_D  1022171713.000000   0.999309000  352         517            517       286        231        50143    23467     26676     50134      0          0          2631530   1223930    1407600    96            0             0          278520.219    0x0c00987a0202d044  0           0            0           0            9           378          0           0            50134       2631152      0           0            113       7050       0         0          39099    2164110   10922    459992    0        0         0           0            0         0          0
USR1MR_D  1022171714.741000   1.741000     287         472            472       274        198        47899    22508     25391     47873      17         0          2514274   1172604    1341670    94            0             0          263678.375    0x0c00987a0202d044  0           0            0           0            9           378          0           0            47873       2512870      17          1026         115       7278       1         38         37075    2056666   10696    449812    0        0         0           0            0         0          0
USR1MR_D  1022171715.263000   0.999522000  266         452            452       260        192        49110    22878     26232     49096      3          0          2582484   1195104    1387380    89            0             0          272797.156    0x0c00987a0202d044  0           0            0           0            11          462          0           0            49096       2581824      3           198          130       8052       1         38         38284    2123868   10684    450064    0        0         0           0            0         0          0
USR1MR_D  1022171716.269000   1.006000     336         527            527       307        220        49985    23187     26798     49976      4          0          2627906   1210650    1417256    94            0             0          278140.844    0x0c00987a0202d044  0           0            0           0            5           210          0           0            49976       2627432      4           264          128       8064       0         0          39083    2166434   10769    453198    0        0         0           0            0         0          0
USR1MR_D  1022171717.932000   1.663000     299         479            479       273        206        48938    22517     26421     48921      6          0          2575532   1178110    1397422    93            0             0          273963.812    0x0c00987a0202d044  0           0            0           0            11          462          0           0            48921       2574738      6           332          130       8148       0         0          38233    2122014   10562    444840    0        0         0           0            0         0          0
USR1MR_D  1022171718.200000   0.999268000  221         410            410       230        180        47700    21873     25827     47675      21         0          2501292   1138298    1362994    88            0             0          263612.438    0x0c00987a0202d044  0           0            0           0            4           168          0           0            47675       2499750      21          1374         121       7530       0         0          37041    2050350   10528    442956    3        102       3           186          0         0          0
USR1MR_D  1022171719.284000   1.084000     266         451            451       275        176        48263    21982     26281     48249      2          0          2532294   1143108    1389186    97            0             0          268193.375    0x0c00987a0202d044  0           0            0           0            12          504          0           0            48249       2531690      2           100          134       8532       0         0          37445    2074682   10671    448542    0        0         0           0            0         0          0
USR1MR_D  1022171720.1095000  1.811000     295         507            507       294        213        49621    22621     27000     49599      4          0          2611286   1179958    1431328    93            0             0          277837.719    0x0c00987a0202d044  0           0            0           0            18          756          0           0            49599       2610330      4           200          113       7074       0         0          39044    2164776   10444    438612    0        0         0           0            0         0          0
USR1MR_D  1022171721.640000   0.999545000  233         486            486       273        213        50166    22964     27202     50160      0          0          2639776   1198584    1441192    93            0             0          280237.719    0x0c00987a0222d044  0           0            0           0            6           252          0           0            50160       2639524      0           0            125       7746       0         0          39445    2186290   10590    445488    0        0         0           0            0         0          0
USR1MR_D  1022171722.427000   0.999787000  250         539            539       314        225        47175    21896     25279     47160      4          0          2478598   1140152    1338446    92            0             0          256399.453    0x0c00987a0222d044  0           0            0           0            11          462          0           0            47160       2477872      4           264          117       7458       0         0          36225    2015758   10822    454920    0        0         0           0            0         0          0
USR1MR_D  1022171723.058000   0.999631000  205         455            455       259        196        48872    22649     26223     48858      8          0          2578544   1187274    1391270    99            0             0          271465.625    0x0c00987a0222d044  0           0            0           0            6           252          0           0            48858       2577860      8           432          114       7260       0         0          38162    2124068   10587    446862    0        0         0           0            0         0          0
USR1MR_D  1022171724.127000   1.069000     234         552            552       309        243        50089    23027     27062     50080      3          0          2634246   1201014    1433232    88            0             0          281685.219    0x0c00987a0222d044  0           0            0           0            6           252          0           0            50080       2633832      3           162          107       6726       0         0          39264    2177144   10710    450028    0        0         1           62           0         0          0
USR1MR_D  1022171725.274000   1.147000     233         517            517       301        216        49908    22880     27028     49883      18         0          2627904   1195840    1432064    93            0             0          279872.562    0x0c00987a0222d044  0           0            0           0            7           294          0           0            49883       2626422      18          1188         139       8694       3         114        39002    2165132   10756    453636    0        0         0           0            0         0          0
USR1MR_D  1022171726.378000   1.104000     238         473            473       269        204        48767    22322     26445     48754      6          0          2565306   1165528    1399778    90            0             0          271439.000    0x0c00987a0222d044  0           0            0           0            7           294          0           0            48754       2564648      6           364          133       8394       5         190        37987    2109006   10634    447388    0        0         0           0            0         0          0

Comparing the column winPktThCnt you notice that without the tcpStates plugin all output of your tcpWin plugin is now 0. Why? Because no flow terminated yet! The timeout is by default three minutes (180 seconds) and the processing time of the pcap is only 0.5 seconds. So one way is to reduce the flow timeout (FLOW_TIMEOUT in tranalyzer.h), the other is to move the code to the t2OnLayer4(...) callback as already indicated above. So delete or comment out the two lines we added in the t2OnFlowTerminate(...) callback and add the lines marked with // <-- in the t2OnLayer4(...) callback.

vi src/tcpWin.c

...
void t2OnLayer4(packet_t *packet, unsigned long flowIndex) {
    const flow_t * const flowP = &flows[flowIndex];
    if (flowP->l4Proto != L3_TCP) return; // process only TCP

    // only 1. frag packet will be processed
    if (!t2_is_first_fragment(packet)) return;

    tcpWinFlow_t * const tcpWinFlowP = &tcpWinFlows[flowIndex];
    const tcpHeader_t * const tcpHeader = (tcpHeader_t*)packet->l4HdrP;
    const uint32_t tcpWin = ntohs(tcpHeader->window);

    if (tcpWin < TCPWIN_THRES) {
        tcpWinFlowP->winThCnt++;                // count the packet
        tcpWinFlowP->stat |= TCPWIN_STAT_THU;   // set the status bit
        tcpWinStat |= tcpWinFlowP->stat;        // <-- Aggregate all packet flags
        winThCntG++;                            // <-- count all winThCnt packet
    }
}
...

Recompile and rerun t2:

t2build tcpWin

t2 -r ~/data/annoloc2.pcap -l -w ~/results/

%repTyp   time                dur          memUsageKB  fillSzHashMap  numFlows  numAFlows  numBFlows  numPkts  numAPkts  numBPkts  numV4Pkts  numV6Pkts  numVxPkts  numBytes  numABytes  numBBytes  numFrgV4Pkts  numFrgV6Pkts  numAlarms  rawBandwidth  globalWarn          0x0042Pkts  0x0042Bytes  0x00fePkts  0x00feBytes  0x0806Pkts  0x0806Bytes  0x8035Pkts  0x8035Bytes  0x0800Pkts  0x0800Bytes  0x86ddPkts  0x86ddBytes  ICMPPkts  ICMPBytes  IGMPPkts  IGMPBytes  TCPPkts  TCPBytes  UDPPkts  UDPBytes  GREPkts  GREBytes  ICMPv6Pkts  ICMPv6Bytes  SCTPPkts  SCTPBytes  winPktThCnt
USR1MR_D  1022171702.125000   0.308953000  18825       2152           2152      1220       932        14548    6878      7670      14542      3          0          765516    358988     406528     31            0             0          262155.094    0x0c00881a0202c044  0           0            0           0            3           126          0           0            14542       765256       3           134          34        2220       0         0          11316    628896    3192     134172    0        0         0           0            0         0          25
USR1MR_D  1022171703.027000   0.999902000  2003        1767           1767      961        806        49194    22820     26374     49162      22         0          2586276   1191528    1394748    97            0             0          270888.438    0x0c00987a0202c044  0           0            0           0            10          420          0           0            49162       2584404      22          1452         129       7938       0         0          37923    2109222   11132    468696    0        0         0           0            0         0          104
USR1MR_D  1022171704.334000   1.307000     835         1112           1112      639        473        48765    22660     26105     48734      26         0          2562726   1182212    1380514    91            0             0          267914.906    0x0c00987a0202c044  0           0            0           0            5           210          0           0            48734       2560800      26          1716         133       8202       0         0          37502    2085364   11125    468950    0        0         0           0            0         0          126
USR1MR_D  1022171705.030000   0.999696000  570         816            816       480        336        47156    22079     25077     47146      2          0          2471500   1148578    1322922    91            0             0          253765.031    0x0c00987a0202c044  0           0            0           0            8           336          0           0            47146       2471064      2           100          124       7704       0         0          36153    2006038   10870    457388    0        0         0           0            0         0          121
USR1MR_D  1022171706.009000   0.999979000  528         658            658       369        289        47251    21942     25309     47239      3          0          2480982   1143508    1337474    96            0             0          257045.938    0x0c00987a0202c044  0           0            0           0            9           378          0           0            47239       2480442      3           162          139       8814       0         0          36192    2013364   10909    458330    0        0         1           62           0         0          110
USR1MR_D  1022171707.298000   1.289000     488         685            685       381        304        48061    22155     25906     48038      5          0          2520286   1153038    1367248    71            0             0          263887.188    0x0c00987a0202d044  0           0            0           0            18          756          0           0            48038       2519208      5           322          112       7032       0         0          37267    2064558   10657    447646    5        170       2           124          0         0          111
USR1MR_D  1022171708.102000   0.999804000  454         595            595       325        270        48284    22114     26170     48262      3          0          2539600   1155564    1384036    79            0             0          266056.719    0x0c00987a0202d044  0           0            0           0            19          798          0           0            48262       2538612      3           190          117       7458       0         0          37526    2084196   10619    446990    1        34        2           124          0         0          90
USR1MR_D  1022171709.695000   1.593000     340         579            579       339        240        49272    22973     26299     49249      7          0          2587936   1198894    1389042    96            0             0          270947.375    0x0c00987a0202d044  0           0            0           0            16          672          0           0            49249       2586870      7           394          143       8910       0         0          38179    2117206   10931    461018    0        0         1           62           0         0          122
USR1MR_D  1022171710.175000   0.999480000  467         564            564       312        252        50508    23624     26884     50497      4          0          2662064   1237564    1424500    97            0             0          282688.781    0x0c00987a0202d044  0           0            0           0            7           294          0           0            50497       2661506      4           264          109       6738       0         0          39825    2209682   10560    445112    7        238       0           0            0         0          96
USR1MR_D  1022171711.193000   1.018000     311         516            516       302        214        48619    22823     25796     48603      2          0          2563366   1196706    1366660    84            0             0          272032.375    0x0c00987a0202d044  0           0            0           0            14          588          0           0            48603       2562646      2           132          113       7122       0         0          38302    2125628   10189    429994    0        0         0           0            0         0          84
USR1MR_D  1022171712.691000   1.498000     295         565            565       327        238        49611    23075     26536     49599      0          0          2603054   1202538    1400516    95            0             0          277082.562    0x0c00987a0202d044  0           0            0           0            12          504          0           0            49599       2602550      0           0            134       8508       0         0          38673    2139862   10792    454180    0        0         0           0            0         0          81
USR1MR_D  1022171713.000000   0.999309000  353         517            517       286        231        50143    23467     26676     50134      0          0          2631530   1223930    1407600    96            0             0          278520.219    0x0c00987a0202d044  0           0            0           0            9           378          0           0            50134       2631152      0           0            113       7050       0         0          39099    2164110   10922    459992    0        0         0           0            0         0          89
USR1MR_D  1022171714.741000   1.741000     286         472            472       274        198        47899    22508     25391     47873      17         0          2514274   1172604    1341670    94            0             0          263678.375    0x0c00987a0202d044  0           0            0           0            9           378          0           0            47873       2512870      17          1026         115       7278       1         38         37075    2056666   10696    449812    0        0         0           0            0         0          115
USR1MR_D  1022171715.263000   0.999522000  267         452            452       260        192        49110    22878     26232     49096      3          0          2582484   1195104    1387380    89            0             0          272797.156    0x0c00987a0202d044  0           0            0           0            11          462          0           0            49096       2581824      3           198          130       8052       1         38         38284    2123868   10684    450064    0        0         0           0            0         0          98
USR1MR_D  1022171716.269000   1.006000     335         527            527       307        220        49985    23187     26798     49976      4          0          2627906   1210650    1417256    94            0             0          278140.844    0x0c00987a0202d044  0           0            0           0            5           210          0           0            49976       2627432      4           264          128       8064       0         0          39083    2166434   10769    453198    0        0         0           0            0         0          72
USR1MR_D  1022171717.932000   1.663000     299         479            479       273        206        48938    22517     26421     48921      6          0          2575532   1178110    1397422    93            0             0          273963.812    0x0c00987a0202d044  0           0            0           0            11          462          0           0            48921       2574738      6           332          130       8148       0         0          38233    2122014   10562    444840    0        0         0           0            0         0          78
USR1MR_D  1022171718.200000   0.999268000  222         410            410       230        180        47700    21873     25827     47675      21         0          2501292   1138298    1362994    88            0             0          263612.438    0x0c00987a0202d044  0           0            0           0            4           168          0           0            47675       2499750      21          1374         121       7530       0         0          37041    2050350   10528    442956    3        102       3           186          0         0          97
USR1MR_D  1022171719.284000   1.084000     266         451            451       275        176        48263    21982     26281     48249      2          0          2532294   1143108    1389186    97            0             0          268193.375    0x0c00987a0202d044  0           0            0           0            12          504          0           0            48249       2531690      2           100          134       8532       0         0          37445    2074682   10671    448542    0        0         0           0            0         0          77
USR1MR_D  1022171720.1095000  1.811000     295         507            507       294        213        49621    22621     27000     49599      4          0          2611286   1179958    1431328    93            0             0          277837.719    0x0c00987a0202d044  0           0            0           0            18          756          0           0            49599       2610330      4           200          113       7074       0         0          39044    2164776   10444    438612    0        0         0           0            0         0          70
USR1MR_D  1022171721.640000   0.999545000  233         486            486       273        213        50166    22964     27202     50160      0          0          2639776   1198584    1441192    93            0             0          280237.719    0x0c00987a0222d044  0           0            0           0            6           252          0           0            50160       2639524      0           0            125       7746       0         0          39445    2186290   10590    445488    0        0         0           0            0         0          83
USR1MR_D  1022171722.427000   0.999787000  250         539            539       314        225        47175    21896     25279     47160      4          0          2478598   1140152    1338446    92            0             0          256399.453    0x0c00987a0222d044  0           0            0           0            11          462          0           0            47160       2477872      4           264          117       7458       0         0          36225    2015758   10822    454920    0        0         0           0            0         0          82
USR1MR_D  1022171723.058000   0.999631000  205         455            455       259        196        48872    22649     26223     48858      8          0          2578544   1187274    1391270    99            0             0          271465.625    0x0c00987a0222d044  0           0            0           0            6           252          0           0            48858       2577860      8           432          114       7260       0         0          38162    2124068   10587    446862    0        0         0           0            0         0          84
USR1MR_D  1022171724.127000   1.069000     233         552            552       309        243        50089    23027     27062     50080      3          0          2634246   1201014    1433232    88            0             0          281685.219    0x0c00987a0222d044  0           0            0           0            6           252          0           0            50080       2633832      3           162          107       6726       0         0          39264    2177144   10710    450028    0        0         1           62           0         0          102
USR1MR_D  1022171725.274000   1.147000     234         517            517       301        216        49908    22880     27028     49883      18         0          2627904   1195840    1432064    93            0             0          279872.562    0x0c00987a0222d044  0           0            0           0            7           294          0           0            49883       2626422      18          1188         139       8694       3         114        39002    2165132   10756    453636    0        0         0           0            0         0          123
USR1MR_D  1022171726.378000   1.104000     237         473            473       269        204        48767    22322     26445     48754      6          0          2565306   1165528    1399778    90            0             0          271439.000    0x0c00987a0222d044  0           0            0           0            7           294          0           0            48754       2564648      6           364          133       8394       5         190        37987    2109006   10634    447388    0        0         0           0            0         0          119

See? Looks better right?

Conclusion

Play a bit around with the different types of reporting and change the config in tranalyzer.h and main.h as being discussed in monitoring mode. And compare the results to the end report. Also try to run t2 on an interface, and play around with the different time base modes and remote control options in main.h.

At this point I like to refer to the monitoring mode tutorial.

And don’t forget to reset the monitoring mode:

t2conf tranalyzer2 -D MONINTTMPCP=0 -D DIFF_REPORT=0 -D MACHINE_REPORT=0 && t2build -R

or use the new command:

t2conf --reset tranalyzer2 && t2build -R

You can download the final version of the tcpWin plugin.

The next tutorial will teach you how to add plugin packet output.

Have fun writing plugins!

See also