click-fastclassifier.cc

Click is a modular router toolkit. To use it you ll need to know how to compile and install the sof

      String step = program.substring(program.begin(), find(program, '\n'));
      program = program.substring(step.end() + 1, program.end());
      // check for many things
      if (isdigit((unsigned char) step[0]) || isspace((unsigned char) step[0])) {
	// real step
	Classifier_Insn e;
	int crap, pos;
	int v[4], m[4];
	sscanf(step.c_str(), "%d %d/%2x%2x%2x%2x%%%2x%2x%2x%2x yes->%n",
	       &crap, &e.offset, &v[0], &v[1], &v[2], &v[3],
	       &m[0], &m[1], &m[2], &m[3], &pos);
	for (int i = 0; i < 4; i++) {
	  e.value.c[i] = v[i];
	  e.mask.c[i] = m[i];
	}
	// read yes destination
	step = step.substring(pos);
	if (step[0] == '[') {
	  sscanf(step.c_str(), "[%d] no->%n", &e.yes, &pos);
	  e.yes = -e.yes;
	} else
	  sscanf(step.c_str(), "step %d no->%n", &e.yes, &pos);
	// read no destination
	step = step.substring(pos);
	if (step[0] == '[') {
	  sscanf(step.c_str(), "[%d]", &e.no);
	  e.no = -e.no;
	} else
	  sscanf(step.c_str(), "step %d", &e.no);
	// push expr onto list
	prog.program.push_back(e);
      } else if (sscanf(step.c_str(), "all->[%d]", &prog.output_everything))
	/* nada */;
      else if (sscanf(step.c_str(), "safe length %d", &prog.safe_length))
	/* nada */;
      else if (sscanf(step.c_str(), "alignment offset %d", &prog.align_offset)) {
	/* nada */;
      }
    }

    // search for an existing fast classifier with the same program
    bool found_program = false;
    for (int i = 0; i < all_programs.size() && !found_program; i++)
      if (prog == all_programs[i]) {
	program_map.push_back(i);
	found_program = true;
      }

    if (!found_program) {
      // set new names
      String class_name = "Fast" + classifier_tname + "@@" + c->name();
      String cxx_name = translate_class_name(class_name);
      prog.eclass = ElementClassT::base_type(class_name);

      // add new program
      all_programs.push_back(prog);
      gen_eclass_names.push_back(class_name);
      gen_cxxclass_names.push_back(cxx_name);
      old_configurations.push_back(c->configuration());
      program_map.push_back(all_programs.size() - 1);
    }
  }

  // complain if any programs missing
  for (int i = 0; i < iprograms.size(); i++)
    if (program_map[i] < 0)
      errh->fatal("classifier program missing for '%s :: %s'!", classifiers[i]->name_c_str(), classifiers[i]->type_name().c_str());
}

static void
output_classifier_program(int which,
			  StringAccum &header, StringAccum &source,
			  ErrorHandler *)
{
  String cxx_name = gen_cxxclass_names[which];
  String class_name = gen_eclass_names[which];
  const Classifier_Program &prog = all_programs[which];
  FastClassifier_Cid *cid = cids[prog.type];
  if (cid->headers) {
    cid->headers(prog, source);
    cid->headers = 0;		// only call cid->headers once
  }

  header << "class " << cxx_name << " : public Element {\n\
  void devirtualize_all() { }\n\
 public:\n  "
	 << cxx_name << "() { }\n  ~" << cxx_name << "() { }\n\
  const char *class_name() const { return \"" << class_name << "\"; }\n\
  const char *port_count() const { return \"1/" << prog.noutputs << "\"; }\n\
  const char *processing() const { return PUSH; }\n";

  if (prog.output_everything >= 0) {
    header << "  void push(int, Packet *);\n};\n";
    source << "void\n" << cxx_name << "::push(int, Packet *p)\n{\n";
    if (prog.output_everything < prog.noutputs)
      source << "  output(" << prog.output_everything << ").push(p);\n";
    else
      source << "  p->kill();\n";
    source << "}\n";
  } else {
    bool need_checked = (prog.safe_length >= cid->guaranteed_packet_length);
    if (need_checked) {
      header << "  void length_checked_push(Packet *);\n";
      source << "void\n" << cxx_name << "::length_checked_push(Packet *p)\n{\n";
      cid->checked_body(prog, source);
      source << "}\n";
    }

    header << "  inline void length_unchecked_push(Packet *);\n\
  void push(int, Packet *);\n};\n";
    source << "inline void\n" << cxx_name
	   << "::length_unchecked_push(Packet *p)\n{\n";
    cid->unchecked_body(prog, source);
    source << "}\n";

    source << "void\n" << cxx_name << "::push(int, Packet *p)\n{\n";
    cid->push_body(prog, source);
    source << "}\n";
  }
}


static void
compile_classifiers(RouterT *r, const String &package_name,
		    RouterT *nr, Vector<ElementT *> &classifiers,
		    int compile_drivers, ErrorHandler *errh)
{
    // create C++ files
    StringAccum header, source, source_body;
    header << "#ifndef CLICK_" << package_name << "_HH\n"
	   << "#define CLICK_" << package_name << "_HH\n"
	   << "#include <click/package.hh>\n#include <click/element.hh>\n";

    // analyze Classifiers into programs
    analyze_classifiers(nr, classifiers, errh);

    // add requirement
    r->add_requirement(package_name);

    // write Classifier programs
    for (int i = 0; i < all_programs.size(); i++)
	output_classifier_program(i, header, source_body, errh);

    // change element landmarks and types
    for (int i = 0; i < classifiers.size(); i++) {
	ElementT *classifier_e = classifiers[i];
	const Classifier_Program &prog = all_programs[program_map[i]];
	classifier_e->set_type(prog.eclass);
	classifier_e->set_configuration(String());
	change_landmark(classifier_e);
    }

    // write final text
    header << "#endif\n";
    source << "/** click-compile: -w */\n";
    {
	StringAccum elem2package, cmd_sa;
	int nclasses = gen_cxxclass_names.size();
	for (int i = 0; i < nclasses; i++)
	    elem2package <<  "-\t\"" << package_name << ".hh\"\t" << gen_cxxclass_names[i] << '-' << gen_eclass_names[i] << '\n';
	cmd_sa << click_buildtool_prog << " elem2package " << package_name;
	source << shell_command_output_string(cmd_sa.take_string(), elem2package.take_string(), errh);
    }
    source << "CLICK_DECLS\n" << source_body << "CLICK_ENDDECLS\n";

    // add source files to archive
    {
	ArchiveElement ae = init_archive_element(package_name + ".cc", 0600);
	ae.data = source.take_string();
	r->add_archive(ae);

	ae.name = package_name + ".hh";
	ae.data = header.take_string();
	r->add_archive(ae);
    }

    // add compiled versions to archive
    if (compile_drivers) {
	int source_ae = r->archive_index(package_name + ".cc");
	BailErrorHandler berrh(errh);
	bool tmpdir_populated = false;

	if (compile_drivers & (1 << Driver::LINUXMODULE))
	    if (String fn = click_compile_archive_file(r->archive(), &r->archive()[source_ae], package_name, "linuxmodule", "", tmpdir_populated, &berrh)) {
		ArchiveElement ae = init_archive_element(package_name + ".ko", 0600);
		ae.data = file_string(fn, errh);
		r->add_archive(ae);
	    }

	if (compile_drivers & (1 << Driver::USERLEVEL))
	    if (String fn = click_compile_archive_file(r->archive(), &r->archive()[source_ae], package_name, "userlevel", "", tmpdir_populated, &berrh)) {
		ArchiveElement ae = init_archive_element(package_name + ".uo", 0600);
		ae.data = file_string(fn, errh);
		r->add_archive(ae);
	    }
    }

    // add elementmap to archive
    {
	String emap_package = "elementmap-" + package_name + ".xml";
	if (r->archive_index(emap_package) < 0)
	    r->add_archive(init_archive_element(emap_package, 0600));
	ArchiveElement &ae = r->archive(emap_package);
	ElementMap em(ae.data);
	ElementTraits t;
	t.header_file = package_name + ".hh";
	t.source_file = package_name + ".cc";
	t.processing_code = "h/h";
	t.flow_code = "x/x";
	for (int i = 0; i < gen_eclass_names.size(); i++) {
	    t.name = gen_eclass_names[i];
	    t.cxx = gen_cxxclass_names[i];
	    em.add(t);
	}
	ae.data = em.unparse("fastclassifier");
    }

    // add classifier configurations to archive
    {
	if (r->archive_index("fastclassifier_info") < 0)
	    r->add_archive(init_archive_element("fastclassifier_info", 0600));
	ArchiveElement &ae = r->archive("fastclassifier_info");
	StringAccum sa;
	for (int i = 0; i < gen_eclass_names.size(); i++) {
	    sa << gen_eclass_names[i] << '\t'
	       << cids[all_programs[i].type]->name << '\t'
	       << cp_quote(old_configurations[i]) << '\n';
	}
	ae.data += sa.take_string();
    }
}



static void
reverse_transformation(RouterT *r, ErrorHandler *)
{
  // parse fastclassifier_config
  if (r->archive_index("fastclassifier_info") < 0)
    return;
  ArchiveElement &fc_ae = r->archive("fastclassifier_info");
  Vector<String> click_names, old_type_names, configurations;
  parse_tabbed_lines(fc_ae.data, &click_names, &old_type_names,
		     &configurations, (void *)0);

  // prepare type_map : type -> configuration #
  HashTable<ElementClassT *, int> type_map(-1);
  for (int i = 0; i < click_names.size(); i++)
    type_map.set(ElementClassT::base_type(click_names[i]), i);

  // change configuration
  for (int i = 0; i < r->nelements(); i++) {
    ElementT *e = r->element(i);
    int x = type_map.get(e->type());
    if (x >= 0) {
      e->set_configuration(configurations[x]);
      e->set_type(ElementClassT::base_type(old_type_names[x]));
    }
  }

  // remove requirements
  {
    Vector<String> requirements = r->requirements();
    for (int i = 0; i < requirements.size(); i++)
      if (requirements[i].substring(0, 14) == "fastclassifier")
	r->remove_requirement(requirements[i]);
  }

  // remove archive elements
  for (int i = 0; i < r->narchive(); i++) {
    ArchiveElement &ae = r->archive(i);
    if (ae.name.substring(0, 14) == "fastclassifier"
	|| ae.name == "elementmap-fastclassifier.xml")
      ae.name = String();
  }
}

extern "C" {
void add_fast_classifiers_1();
void add_fast_classifiers_2();
}

int
main(int argc, char **argv)
{
  click_static_initialize();
  CLICK_DEFAULT_PROVIDES;
  ErrorHandler *errh = new PrefixErrorHandler(ErrorHandler::default_handler(), "click-fastclassifier: ");

  // read command line arguments
  Clp_Parser *clp =
    Clp_NewParser(argc, argv, sizeof(options) / sizeof(options[0]), options);
  Clp_SetOptionChar(clp, '+', Clp_ShortNegated);
  program_name = Clp_ProgramName(clp);

  const char *router_file = 0;
  const char *output_file = 0;
  int compile_drivers = 0;
  bool combine_classifiers = true;
  bool do_compile = true;
  bool source_only = false;
  bool config_only = false;
  bool reverse = false;
  bool file_is_expr = false;

  while (1) {
    int opt = Clp_Next(clp);
    switch (opt) {

     case HELP_OPT:
      usage();
      exit(0);
      break;

     case VERSION_OPT:
      printf("click-fastclassifier (Click) %s\n", CLICK_VERSION);
      printf("Copyright (c) 1999-2000 Massachusetts Institute of Technology\n\
Copyright (c) 2000-2001 Mazu Networks, Inc.\n\
Copyright (c) 2001 International Computer Science Institute\n\
Copyright (c) 2007 Regents of the University of California\n\
This is free software; see the source for copying conditions.\n\
There is NO warranty, not even for merchantability or fitness for a\n\
particular purpose.\n");
      exit(0);
      break;

     case CLICKPATH_OPT:
      set_clickpath(clp->vstr);
      break;

     case ROUTER_OPT:
     case EXPRESSION_OPT:
     router_file:
      if (router_file) {
	errh->error("router configuration specified twice");
	goto bad_option;
      }
      router_file = clp->vstr;
      file_is_expr = (opt == EXPRESSION_OPT);
      break;

     case Clp_NotOption:
      if (!click_maybe_define(clp->vstr, errh))
	  goto router_file;
      break;

     case OUTPUT_OPT:
      if (output_file) {
	errh->error("output file specified twice");
	goto bad_option;
      }
      output_file = clp->vstr;
      break;

     case COMBINE_OPT:
      combine_classifiers = !clp->negated;
      break;

     case COMPILE_OPT:
      do_compile = !clp->negated;
      break;

     case REVERSE_OPT:
      reverse = !clp->negated;
      break;

     case SOURCE_OPT:
      source_only = !clp->negated;
      break;

     case CONFIG_OPT:
      config_only = !clp->negated;
      break;

     case KERNEL_OPT:
      compile_drivers |= 1 << Driver::LINUXMODULE;
      break;

     case USERLEVEL_OPT:
      compile_drivers |= 1 << Driver::USERLEVEL;
      break;

     case QUIET_OPT:
      quiet_arg = (clp->negated ? "" : "-q ");
      break;

     case VERBOSE_OPT:
      verbose = !clp->negated;
      break;

     bad_option:
     case Clp_BadOption:
      short_usage();
      exit(1);
      break;

     case Clp_Done:
      goto done;

    }
  }

 done:
  RouterT *r = read_router(router_file, file_is_expr, errh);
  if (r)
    r->flatten(errh);
  if (!r || errh->nerrors() > 0)
    exit(1);
  if (source_only || config_only)
    compile_drivers = 0;

  // open output file
  FILE *outf = stdout;
  if (output_file && strcmp(output_file, "-") != 0) {
    outf = fopen(output_file, "w");
    if (!outf)
      errh->fatal("%s: %s", output_file, strerror(errno));
  }

  // handle reverse case
  if (reverse) {
    reverse_transformation(r, errh);
    write_router_file(r, outf, errh);
    exit(0);
  }

  // install classifier handlers
  add_interesting_handler("program");
  add_fast_classifiers_1();
  add_fast_classifiers_2();

  // find Click binaries
  runclick_prog = clickpath_find_file("click", "bin", CLICK_BINDIR, errh);
  click_buildtool_prog = clickpath_find_file("click-buildtool", "bin", CLICK_BINDIR, errh);

  // find Classifiers
  Vector<ElementT *> classifiers;
  for (RouterT::iterator x = r->begin_elements(); x; x++)
    if (cid_name_map.get(x->type_name()) >= 0)
      classifiers.push_back(x);

  // quit early if no Classifiers
  if (classifiers.size() == 0) {
    if (source_only)
      errh->message("no Classifiers in router");
    else
      write_router_file(r, outf, errh);
    exit(0);
  }

  // try combining classifiers
  if (combine_classifiers) {
    bool any_combined = false;
    for (int i = 0; i < classifiers.size(); i++)
      any_combined |= try_combine_classifiers(r, classifiers[i]);
    if (any_combined)
      try_remove_classifiers(r, classifiers);
  }

  // create classifiers program
  RouterT *classprogr = classifiers_program(r, classifiers);

  // figure out package name
  String package_name;
  {
      md5_state_t pms;
      char buf[MD5_TEXT_DIGEST_MAX_SIZE];
      String s = classprogr->configuration_string();
      md5_init(&pms);
      md5_append(&pms, (const md5_byte_t *) s.data(), s.length());
      int buflen = md5_finish_text(&pms, buf, 0);
      md5_free(&pms);
      package_name = "clickfc_" + String(buf, buflen);
  }

  if (do_compile)
    compile_classifiers(r, package_name, classprogr, classifiers, compile_drivers, errh);

  // write output
  if (source_only) {
    if (r->archive_index(package_name + ".hh") < 0) {
      errh->error("no source code generated");
      exit(1);
    }
    const ArchiveElement &aeh = r->archive(package_name + ".hh");
    const ArchiveElement &aec = r->archive(package_name + ".cc");
    ignore_result(fwrite(aeh.data.data(), 1, aeh.data.length(), outf));
    ignore_result(fwrite(aec.data.data(), 1, aec.data.length(), outf));
  } else if (config_only) {
    String config = r->configuration_string();
    ignore_result(fwrite(config.data(), 1, config.length(), outf));
  } else
    write_router_file(r, outf, errh);

  exit(0);
}