The Tcpdump Group git mirrors - libpcap/blob - testprogs/visopts.py

   1 #!/usr/bin/env python3
   2
   3 """
   4 This program parses the output from pcap_compile() to visualize the CFG after
   5 each optimize phase.
   6
   7 Usage guide:
   8 1. Enable optimizer debugging code when configure libpcap,
   9    and build libpcap & the test programs
  10        ./configure --enable-optimizer-dbg
  11        make
  12        make testprogs
  13 2. Run filtertest to compile BPF expression and produce the CFG as a
  14    DOT graph, save to output a.txt
  15        testprogs/filtertest -g EN10MB host 192.168.1.1 > a.txt
  16 3. Send a.txt to this program's standard input
  17        cat a.txt | testprogs/visopts.py
  18    (Graphviz must be installed)
  19 4. Step 2&3 can be merged:
  20        testprogs/filtertest -g EN10MB host 192.168.1.1 | testprogs/visopts.py
  21 5. The standard output is something like this:
  22        generated files under directory: /tmp/visopts-W9ekBw
  23          the directory will be removed when this programs finished.
  24        open this link: http://localhost:39062/expr1.html
  25 6. Open the URL at the 3rd line in a browser.
  26
  27 Note:
  28 1. The CFG is translated to SVG images, expr1.html embeds them as external
  29    documents. If you open expr1.html as local file using file:// protocol, some
  30    browsers will deny such requests so the web page will not work properly.
  31    For Chrome, you can run it using the following command to avoid this:
  32        chromium --disable-web-security
  33    That's why this program starts a localhost HTTP server.
  34 2. expr1.html uses jQuery from https://ajax.googleapis.com, so it needs Internet
  35    access to work.
  36 """
  37
  38 import sys, os
  39 import string
  40
  41 html_template = string.Template("""
  42 <html>
  43   <head>
  44     <title>BPF compiler optimization phases for "${expr_html}"</title>
  45     <style type="text/css">
  46       .hc {
  47          /* half width container */
  48          display: inline-block;
  49          float: left;
  50          width: 50%;
  51       }
  52     </style>
  53
  54     <script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"/></script>
  55     <!--script type="text/javascript" src="./jquery.min.js"/></script-->
  56     <script type="text/javascript">
  57       var expr = '${expr_json}';
  58       var exprid = 1;
  59       var gcount = ${gcount};
  60       var logs = JSON.parse('${logs}');
  61       logs[gcount] = "";
  62
  63       var leftsvg = null;
  64       var rightsvg = null;
  65
  66       function gurl(index) {
  67          index += 1;
  68          if (index < 10)
  69            s = "00" + index;
  70          else if (index < 100)
  71            s = "0" + index;
  72          else
  73            s = "" + index;
  74          return "./expr" + exprid + "_g" + s + ".svg"
  75       }
  76
  77       function annotate_svgs() {
  78          if (!leftsvg || !rightsvg) return;
  79
  80          $$.each([$$(leftsvg), $$(rightsvg)], function() {
  81            $$(this).find("[id|='block'][opacity]").each(function() {
  82              $$(this).removeAttr('opacity');
  83             });
  84           });
  85
  86          $$(leftsvg).find("[id|='block']").each(function() {
  87            var has = $$(rightsvg).find("#" + this.id).length != 0;
  88            if (!has) $$(this).attr("opacity", "0.4");
  89            else {
  90              $$(this).click(function() {
  91                 var target = $$(rightsvg).find("#" + this.id);
  92                 var offset = $$("#rightsvgc").offset().top + target.position().top;
  93                 window.scrollTo(0, offset);
  94                 target.focus();
  95              });
  96            }
  97           });
  98          $$(rightsvg).find("[id|='block']").each(function() {
  99            var has = $$(leftsvg).find("#" + this.id).length != 0;
 100            if (!has) $$(this).attr("opacity", "0.4");
 101            else {
 102              $$(this).click(function() {
 103                 var target = $$(leftsvg).find("#" + this.id);
 104                 var offset = $$("#leftsvgc").offset().top + target.position().top;
 105                 window.scrollTo(0, offset);
 106                 target.focus();
 107              });
 108            }
 109           });
 110       }
 111
 112       function init_svgroot(svg) {
 113          svg.setAttribute("width", "100%");
 114          svg.setAttribute("height", "100%");
 115       }
 116       function wait_leftsvg() {
 117          if (leftsvg) return;
 118          var doc = document.getElementById("leftsvgc").getSVGDocument();
 119          if (doc == null) {
 120             setTimeout(wait_leftsvg, 500);
 121             return;
 122          }
 123          leftsvg = doc.documentElement;
 124          //console.log(leftsvg);
 125          // initialize it
 126          init_svgroot(leftsvg);
 127          annotate_svgs();
 128       }
 129       function wait_rightsvg() {
 130          if (rightsvg) return;
 131          var doc = document.getElementById("rightsvgc").getSVGDocument();
 132          if (doc == null) {
 133             setTimeout(wait_rightsvg, 500);
 134             return;
 135          }
 136          rightsvg = doc.documentElement;
 137          //console.log(rightsvg);
 138          // initialize it
 139          init_svgroot(rightsvg);
 140          annotate_svgs();
 141       }
 142       function load_left(index) {
 143         var url = gurl(index);
 144         var frag = "<embed id='leftsvgc'  type='image/svg+xml' pluginspage='https://www.adobe.com/svg/viewer/install/' src='" + url + "'/>";
 145         $$("#lsvg").html(frag);
 146         $$("#lcomment").html(logs[index]);
 147         $$("#lsvglink").attr("href", url);
 148         leftsvg = null;
 149         wait_leftsvg();
 150       }
 151       function load_right(index) {
 152         var url = gurl(index);
 153         var frag = "<embed id='rightsvgc' type='image/svg+xml' pluginspage='https://www.adobe.com/svg/viewer/install/' src='" + url + "'/>";
 154         $$("#rsvg").html(frag);
 155         $$("#rcomment").html(logs[index]);
 156         $$("#rsvglink").attr("href", url);
 157         rightsvg = null;
 158         wait_rightsvg();
 159       }
 160
 161       $$(document).ready(function() {
 162         for (var i = 0; i < gcount; i++) {
 163           var opt = "<option value='" + i + "'>loop" + i + " -- " + logs[i] + "</option>";
 164           $$("#lselect").append(opt);
 165           $$("#rselect").append(opt);
 166         }
 167         var on_selected = function() {
 168           var index = parseInt($$(this).children("option:selected").val());
 169           if (this.id == "lselect")
 170              load_left(index);
 171           else
 172              load_right(index);
 173         }
 174         $$("#lselect").change(on_selected);
 175         $$("#rselect").change(on_selected);
 176
 177         $$("#backward").click(function() {
 178           var index = parseInt($$("#lselect option:selected").val());
 179           if (index <= 0) return;
 180           $$("#lselect").val(index - 1).change();
 181           $$("#rselect").val(index).change();
 182         });
 183         $$("#forward").click(function() {
 184           var index = parseInt($$("#rselect option:selected").val());
 185           if (index >= gcount - 1) return;
 186           $$("#lselect").val(index).change();
 187           $$("#rselect").val(index + 1).change();
 188         });
 189
 190         if (gcount >= 1) $$("#lselect").val(0).change();
 191         if (gcount >= 2) $$("#rselect").val(1).change();
 192       });
 193     </script>
 194   </head>
 195   <body style="width: 96%">
 196     <div>
 197       <h1>${expr_html}</h1>
 198       <div style="text-align: center;">
 199         <button id="backward" type="button">&lt;&lt;</button>
 200           &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
 201         <button id="forward" type="button">&gt;&gt;</button>
 202       </div>
 203     </div>
 204     <br/>
 205     <div style="clear: both;">
 206        <div class="hc lc">
 207         <select id="lselect"></select>
 208         <a id="lsvglink" target="_blank">open this svg in browser</a>
 209         <p id="lcomment"></p>
 210        </div>
 211        <div class="hc rc">
 212         <select id="rselect"></select>
 213         <a id="rsvglink" target="_blank">open this svg in browser</a>
 214         <p id="rcomment"></p>
 215        </div>
 216     </div>
 217     <br/>
 218     <div style="clear: both;">
 219        <div id="lsvg"  class="hc lc"></div>
 220        <div id="rsvg" class="hc rc"></div>
 221     </div>
 222   </body>
 223 </html>
 224 """)
 225
 226 def write_html(expr, gcount, logs):
 227     import html
 228     import json
 229
 230     # In the Python 2.7 version this used to be str.encode('string-escape'),
 231     # which was a normal string, but in Python 3 the "string_escape" encoding
 232     # no longer exists and even with the "unicode_escape" encoding encode()
 233     # always returns a binary string.  So let's just escape the single quotes
 234     # here and hope the result is a valid JavaScript string literal.
 235     def encode(s):
 236         return s.replace("'", "\'")
 237
 238     mapping = {
 239         'expr_html': html.escape(expr),
 240         'expr_json': encode(expr),
 241         'gcount': gcount,
 242         'logs': encode(json.dumps([s.strip().replace("\n", "<br/>") for s in logs])),
 243     }
 244     with open("expr1.html", "wt") as f:
 245         f.write(html_template.safe_substitute(mapping))
 246
 247 def render_on_html(infile):
 248     import subprocess
 249
 250     expr = None
 251     gid = 1
 252     log = ""
 253     dot = ""
 254     indot = 0
 255     logs = []
 256
 257     for line in infile:
 258         if line.startswith("machine codes for filter:"):
 259             expr = line[len("machine codes for filter:"):].strip()
 260             break
 261         elif line.startswith("digraph BPF {"):
 262             indot = 1
 263             dot = line
 264         elif indot:
 265             dot += line
 266             if line.startswith("}"):
 267                 indot = 2
 268         else:
 269             log += line
 270
 271         if indot == 2:
 272             try:
 273                 svg=subprocess.check_output(['dot', '-Tsvg'], input=dot, universal_newlines=True)
 274             except OSError as ose:
 275                 print("Failed to run 'dot':", ose)
 276                 print("(Is Graphviz installed?)")
 277                 return False
 278             except subprocess.CalledProcessError as cpe:
 279                 print("Got an error from the 'dot' process: ", cpe)
 280                 return False
 281
 282             with open("expr1_g%03d.svg" % gid, "wt") as f:
 283                 f.write(svg)
 284
 285             logs.append(log)
 286             gid += 1
 287             log = ""
 288             dot = ""
 289             indot = 0
 290
 291     if indot != 0:
 292         #unterminated dot graph for expression
 293         return False
 294     if expr is None:
 295         # BPF parser encounter error(s)
 296         return False
 297     write_html(expr, gid - 1, logs)
 298     return True
 299
 300 def run_httpd():
 301     import http.server
 302
 303     httpd = http.server.HTTPServer(("localhost", 0), http.server.SimpleHTTPRequestHandler)
 304     print("open this link: http://localhost:%d/expr1.html" % httpd.server_port)
 305     try:
 306         httpd.serve_forever()
 307     except KeyboardInterrupt as e:
 308         pass
 309
 310 def main():
 311     import tempfile
 312     import atexit
 313     import shutil
 314     os.chdir(tempfile.mkdtemp(prefix="visopts-"))
 315     atexit.register(shutil.rmtree, os.getcwd())
 316     print("generated files under directory: %s" % os.getcwd())
 317     print("  the directory will be removed when this program has finished.")
 318
 319     if not render_on_html(sys.stdin):
 320         return 1
 321     run_httpd()
 322     return 0
 323
 324 if __name__ == "__main__":
 325     if '-h' in sys.argv or '--help' in sys.argv:
 326         print(__doc__)
 327         exit(0)
 328     exit(main())