src/test_filter_rewrite.cpp

   1 /* This file is part of Metaproxy.
   2    Copyright (C) 2005-2013 Index Data
   3
   4 Metaproxy is free software; you can redistribute it and/or modify it under
   5 the terms of the GNU General Public License as published by the Free
   6 Software Foundation; either version 2, or (at your option) any later
   7 version.
   8
   9 Metaproxy is distributed in the hope that it will be useful, but WITHOUT ANY
  10 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12 for more details.
  13
  14 You should have received a copy of the GNU General Public License
  15 along with this program; if not, write to the Free Software
  16 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17 */
  18
  19 #include "config.hpp"
  20 #include <iostream>
  21 #include <stdexcept>
  22
  23 #include "filter_http_client.hpp"
  24 #include <metaproxy/util.hpp>
  25 #include "router_chain.hpp"
  26 #include <metaproxy/package.hpp>
  27
  28 #include <boost/regex.hpp>
  29 #include <boost/lexical_cast.hpp>
  30
  31 #define BOOST_AUTO_TEST_MAIN
  32 #define BOOST_TEST_DYN_LINK
  33
  34 #include <boost/test/auto_unit_test.hpp>
  35
  36 using namespace boost::unit_test;
  37 namespace mp = metaproxy_1;
  38
  39 typedef std::pair<std::string, std::string> string_pair;
  40 typedef std::vector<string_pair> spair_vec;
  41 typedef spair_vec::iterator spv_iter;
  42
  43 class FilterHeaderRewrite: public mp::filter::Base {
  44 public:
  45     void process(mp::Package & package) const {
  46         Z_GDU *gdu = package.request().get();
  47         //map of request/response vars
  48         std::map<std::string, std::string> vars;
  49         //we have an http req
  50         if (gdu && gdu->which == Z_GDU_HTTP_Request)
  51         {
  52             Z_HTTP_Request *hreq = gdu->u.HTTP_Request;
  53             mp::odr o;
  54             //rewrite the request line
  55             std::string path;
  56             if (strstr(hreq->path, "http://") == hreq->path)
  57             {
  58                 std::cout << "Path in the method line is absolute, "
  59                     "possibly a proxy request\n";
  60                 path += hreq->path;
  61             }
  62             else
  63             {
  64                 //TODO what about proto
  65                path += z_HTTP_header_lookup(hreq->headers, "Host");
  66                path += hreq->path;
  67             }
  68             std::cout << "Proxy request URL is " << path << std::endl;
  69             std::string npath =
  70                 test_patterns(vars, path, req_uri_pats, req_groups_bynum);
  71             std::cout << "Resp request URL is " << npath << std::endl;
  72             if (!npath.empty())
  73                 hreq->path = odr_strdup(o, npath.c_str());
  74             std::cout << ">> Request headers" << std::endl;
  75             //iterate headers
  76             for (Z_HTTP_Header *header = hreq->headers;
  77                     header != 0;
  78                     header = header->next)
  79             {
  80                 std::string sheader(header->name);
  81                 sheader += ": ";
  82                 sheader += header->value;
  83                 std::cout << header->name << ": " << header->value << std::endl;
  84                 std::string out = test_patterns(vars,
  85                         sheader,
  86                         req_uri_pats, req_groups_bynum);
  87                 if (!out.empty())
  88                 {
  89                     size_t pos = out.find(": ");
  90                     if (pos == std::string::npos)
  91                     {
  92                         std::cout << "Header malformed during rewrite, ignoring";
  93                         continue;
  94                     }
  95                     header->name = odr_strdup(o, out.substr(0, pos).c_str());
  96                     header->value = odr_strdup(o, out.substr(pos+2,
  97                                 std::string::npos).c_str());
  98                 }
  99             }
 100             package.request() = gdu;
 101         }
 102         package.move();
 103         gdu = package.response().get();
 104         if (gdu && gdu->which == Z_GDU_HTTP_Response)
 105         {
 106             Z_HTTP_Response *hr = gdu->u.HTTP_Response;
 107             std::cout << "Response " << hr->code;
 108             std::cout << "<< Respose headers" << std::endl;
 109             mp::odr o;
 110             //iterate headers
 111             for (Z_HTTP_Header *header = hr->headers;
 112                     header != 0;
 113                     header = header->next)
 114             {
 115                 std::cout << header->name << ": " << header->value << std::endl;
 116                 std::string out = test_patterns(vars,
 117                         std::string(header->value),
 118                         res_uri_pats, res_groups_bynum);
 119                 if (!out.empty())
 120                     header->value = odr_strdup(o, out.c_str());
 121             }
 122             package.response() = gdu;
 123         }
 124     };
 125
 126     void configure(const xmlNode* ptr, bool test_only, const char *path) {};
 127
 128     /**
 129      * Tests pattern from the vector in order and executes recipe on
 130        the first match.
 131      */
 132     const std::string test_patterns(
 133             std::map<std::string, std::string> & vars,
 134             const std::string & txt,
 135             const spair_vec & uri_pats,
 136             const std::vector<std::map<int, std::string> > & groups_bynum_vec)
 137         const
 138     {
 139         for (int i = 0; i < uri_pats.size(); i++)
 140         {
 141             std::string out = search_replace(vars, txt,
 142                     uri_pats[i].first, uri_pats[i].second,
 143                     groups_bynum_vec[i]);
 144             if (!out.empty()) return out;
 145         }
 146         return "";
 147     }
 148
 149
 150     const std::string search_replace(
 151             std::map<std::string, std::string> & vars,
 152             const std::string & txt,
 153             const std::string & uri_re,
 154             const std::string & uri_pat,
 155             const std::map<int, std::string> & groups_bynum) const
 156     {
 157         //exec regex against value
 158         boost::regex re(uri_re);
 159         boost::smatch what;
 160         std::string::const_iterator start, end;
 161         start = txt.begin();
 162         end = txt.end();
 163         std::string out;
 164         while (regex_search(start, end, what, re)) //find next full match
 165         {
 166             unsigned i;
 167             for (i = 1; i < what.size(); ++i)
 168             {
 169                 //check if the group is named
 170                 std::map<int, std::string>::const_iterator it
 171                     = groups_bynum.find(i);
 172                 if (it != groups_bynum.end())
 173                 {   //it is
 174                     std::string name = it->second;
 175                     if (!what[i].str().empty())
 176                         vars[name] = what[i];
 177                 }
 178
 179             }
 180             //prepare replacement string
 181             std::string rvalue = sub_vars(uri_pat, vars);
 182             //rewrite value
 183             std::string rhvalue = what.prefix().str()
 184                 + rvalue + what.suffix().str();
 185             std::cout << "! Rewritten '"+what.str(0)+"' to '"+rvalue+"'\n";
 186             out += rhvalue;
 187             start = what[0].second; //move search forward
 188         }
 189         return out;
 190     }
 191
 192     static void parse_groups(
 193             const spair_vec & uri_pats,
 194             std::vector<std::map<int, std::string> > & groups_bynum_vec)
 195     {
 196         for (int h = 0; h < uri_pats.size(); h++)
 197         {
 198             int gnum = 0;
 199             bool esc = false;
 200             //regex is first, subpat is second
 201             std::string str = uri_pats[h].first;
 202             //for each pair we have an indexing map
 203             std::map<int, std::string> groups_bynum;
 204             for (int i = 0; i < str.size(); ++i)
 205             {
 206                 if (!esc && str[i] == '\\')
 207                 {
 208                     esc = true;
 209                     continue;
 210                 }
 211                 if (!esc && str[i] == '(') //group starts
 212                 {
 213                     gnum++;
 214                     if (i+1 < str.size() && str[i+1] == '?') //group with attrs
 215                     {
 216                         i++;
 217                         if (i+1 < str.size() && str[i+1] == ':') //non-capturing
 218                         {
 219                             if (gnum > 0) gnum--;
 220                             i++;
 221                             continue;
 222                         }
 223                         if (i+1 < str.size() && str[i+1] == 'P') //optional, python
 224                             i++;
 225                         if (i+1 < str.size() && str[i+1] == '<') //named
 226                         {
 227                             i++;
 228                             std::string gname;
 229                             bool term = false;
 230                             while (++i < str.size())
 231                             {
 232                                 if (str[i] == '>') { term = true; break; }
 233                                 if (!isalnum(str[i]))
 234                                     throw mp::filter::FilterException
 235                                         ("Only alphanumeric chars allowed, found "
 236                                          " in '"
 237                                          + str
 238                                          + "' at "
 239                                          + boost::lexical_cast<std::string>(i));
 240                                 gname += str[i];
 241                             }
 242                             if (!term)
 243                                 throw mp::filter::FilterException
 244                                     ("Unterminated group name '" + gname
 245                                      + " in '" + str +"'");
 246                             groups_bynum[gnum] = gname;
 247                             std::cout << "Found named group '" << gname
 248                                 << "' at $" << gnum << std::endl;
 249                         }
 250                     }
 251                 }
 252                 esc = false;
 253             }
 254             groups_bynum_vec.push_back(groups_bynum);
 255         }
 256     }
 257
 258     static std::string sub_vars (const std::string & in,
 259             const std::map<std::string, std::string> & vars)
 260     {
 261         std::string out;
 262         bool esc = false;
 263         for (int i = 0; i < in.size(); ++i)
 264         {
 265             if (!esc && in[i] == '\\')
 266             {
 267                 esc = true;
 268                 continue;
 269             }
 270             if (!esc && in[i] == '$') //var
 271             {
 272                 if (i+1 < in.size() && in[i+1] == '{') //ref prefix
 273                 {
 274                     ++i;
 275                     std::string name;
 276                     bool term = false;
 277                     while (++i < in.size())
 278                     {
 279                         if (in[i] == '}') { term = true; break; }
 280                         name += in[i];
 281                     }
 282                     if (!term) throw mp::filter::FilterException
 283                         ("Unterminated var ref in '"+in+"' at "
 284                          + boost::lexical_cast<std::string>(i));
 285                     std::map<std::string, std::string>::const_iterator it
 286                         = vars.find(name);
 287                     if (it != vars.end())
 288                     {
 289                         out += it->second;
 290                     }
 291                 }
 292                 else
 293                 {
 294                     throw mp::filter::FilterException
 295                         ("Malformed or trimmed var ref in '"
 296                          +in+"' at "+boost::lexical_cast<std::string>(i));
 297                 }
 298                 continue;
 299             }
 300             //passthru
 301             out += in[i];
 302             esc = false;
 303         }
 304         return out;
 305     }
 306
 307     void configure(
 308             const spair_vec req_uri_pats,
 309             const spair_vec res_uri_pats)
 310     {
 311        //TODO should we really copy them out?
 312        this->req_uri_pats = req_uri_pats;
 313        this->res_uri_pats = res_uri_pats;
 314        //pick up names
 315        parse_groups(req_uri_pats, req_groups_bynum);
 316        parse_groups(res_uri_pats, res_groups_bynum);
 317     };
 318
 319 private:
 320     std::map<std::string, std::string> vars;
 321     spair_vec req_uri_pats;
 322     spair_vec res_uri_pats;
 323     std::vector<std::map<int, std::string> > req_groups_bynum;
 324     std::vector<std::map<int, std::string> > res_groups_bynum;
 325
 326 };
 327
 328
 329 BOOST_AUTO_TEST_CASE( test_filter_rewrite_1 )
 330 {
 331     try
 332     {
 333        FilterHeaderRewrite fhr;
 334     }
 335     catch ( ... ) {
 336         BOOST_CHECK (false);
 337     }
 338 }
 339
 340 BOOST_AUTO_TEST_CASE( test_filter_rewrite_2 )
 341 {
 342     try
 343     {
 344         mp::RouterChain router;
 345
 346         FilterHeaderRewrite fhr;
 347
 348         spair_vec vec_req;
 349         vec_req.push_back(std::make_pair(
 350         "(?<proto>http\\:\\/\\/s?)(?<pxhost>[^\\/?#]+)\\/(?<pxpath>[^\\/]+)"
 351         "\\/(?<host>[^\\/]+)(?<path>.*)",
 352         "${proto}${host}${path}"
 353         ));
 354         vec_req.push_back(std::make_pair(
 355         "(?:Host\\: )(.*)",
 356         "Host: localhost"
 357         ));
 358
 359         spair_vec vec_res;
 360         vec_res.push_back(std::make_pair(
 361         "(?<proto>http\\:\\/\\/s?)(?<host>[^\\/?#]+)\\/(?<path>[^ >]+)",
 362         "http://${pxhost}/${pxpath}/${host}/${path}"
 363         ));
 364
 365         fhr.configure(vec_req, vec_res);
 366
 367         mp::filter::HTTPClient hc;
 368
 369         router.append(fhr);
 370         router.append(hc);
 371
 372         // create an http request
 373         mp::Package pack;
 374
 375         mp::odr odr;
 376         Z_GDU *gdu_req = z_get_HTTP_Request_uri(odr,
 377         "http://proxyhost/proxypath/localhost:80/~jakub/targetsite.php", 0, 1);
 378
 379         pack.request() = gdu_req;
 380
 381         //feed to the router
 382         pack.router(router).move();
 383
 384         //analyze the response
 385         Z_GDU *gdu_res = pack.response().get();
 386         BOOST_CHECK(gdu_res);
 387         BOOST_CHECK_EQUAL(gdu_res->which, Z_GDU_HTTP_Response);
 388
 389         Z_HTTP_Response *hres = gdu_res->u.HTTP_Response;
 390         BOOST_CHECK(hres);
 391
 392     }
 393     catch (std::exception & e) {
 394         std::cout << e.what();
 395         BOOST_CHECK (false);
 396     }
 397 }
 398
 399 /*
 400  * Local variables:
 401  * c-basic-offset: 4
 402  * c-file-style: "Stroustrup"
 403  * indent-tabs-mode: nil
 404  * End:
 405  * vim: shiftwidth=4 tabstop=8 expandtab
 406  */
 407