src/filter_http_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 <metaproxy/filter.hpp>
  21 #include <metaproxy/package.hpp>
  22 #include <metaproxy/util.hpp>
  23 #include "filter_http_rewrite.hpp"
  24 #include "html_parser.hpp"
  25
  26 #include <yaz/zgdu.h>
  27 #include <yaz/log.h>
  28
  29 #include <stack>
  30 #include <boost/regex.hpp>
  31 #include <boost/lexical_cast.hpp>
  32 #include <boost/algorithm/string.hpp>
  33
  34 #include <map>
  35
  36 namespace mp = metaproxy_1;
  37 namespace yf = mp::filter;
  38
  39 namespace metaproxy_1 {
  40     namespace filter {
  41         class HttpRewrite::Replace {
  42         public:
  43             bool start_anchor;
  44             boost::regex re;
  45             boost::smatch what;
  46             std::string recipe;
  47             std::map<int, std::string> group_index;
  48             std::string sub_vars(
  49                 const std::map<std::string, std::string> & vars) const;
  50             void parse_groups(std::string pattern);
  51         };
  52
  53         class HttpRewrite::Rule {
  54         public:
  55             std::list<Replace> replace_list;
  56             bool test_patterns(
  57                 std::map<std::string, std::string> &vars,
  58                 std::string &txt, bool anchor);
  59         };
  60         class HttpRewrite::Within {
  61         public:
  62             std::string header;
  63             std::string attr;
  64             std::string tag;
  65             std::string type;
  66             bool reqline;
  67             RulePtr rule;
  68             bool exec(std::map<std::string, std::string> &vars,
  69                       std::string &txt, bool anchor) const;
  70         };
  71
  72         class HttpRewrite::Content {
  73         public:
  74             std::string type;
  75             boost::regex content_re;
  76             std::list<Within> within_list;
  77             void configure(const xmlNode *ptr,
  78                            std::map<std::string, RulePtr > &rules);
  79             void quoted_literal(std::string &content,
  80                                 std::map<std::string, std::string> &vars) const;
  81             void parse(int verbose, std::string &content,
  82                        std::map<std::string, std::string> & vars) const;
  83         };
  84         class HttpRewrite::Phase {
  85         public:
  86             Phase();
  87             int m_verbose;
  88             std::list<Content> content_list;
  89             void rewrite_reqline(mp::odr & o, Z_HTTP_Request *hreq,
  90                 std::map<std::string, std::string> & vars) const;
  91             void rewrite_headers(mp::odr & o, Z_HTTP_Header *headers,
  92                 std::map<std::string, std::string> & vars) const;
  93             void rewrite_body(mp::odr & o,
  94                               const char *content_type,
  95                               char **content_buf, int *content_len,
  96                               std::map<std::string, std::string> & vars) const;
  97         };
  98         class HttpRewrite::Event : public HTMLParserEvent {
  99             void openTagStart(const char *tag, int tag_len);
 100             void anyTagEnd(const char *tag, int tag_len, int close_it);
 101             void attribute(const char *tag, int tag_len,
 102                            const char *attr, int attr_len,
 103                            const char *value, int val_len,
 104                            const char *sep);
 105             void closeTag(const char *tag, int tag_len);
 106             void text(const char *value, int len);
 107             const Content *m_content;
 108             WRBUF m_w;
 109             std::stack<std::list<Within>::const_iterator> s_within;
 110             std::map<std::string, std::string> &m_vars;
 111         public:
 112             Event(const Content *p, std::map<std::string, std::string> &vars);
 113             ~Event();
 114             const char *result();
 115         };
 116     }
 117 }
 118
 119 yf::HttpRewrite::HttpRewrite() :
 120     req_phase(new Phase), res_phase(new Phase)
 121 {
 122 }
 123
 124 yf::HttpRewrite::~HttpRewrite()
 125 {
 126 }
 127
 128 void yf::HttpRewrite::process(mp::Package & package) const
 129 {
 130     yaz_log(YLOG_LOG, "HttpRewrite begins....");
 131     Z_GDU *gdu = package.request().get();
 132     //map of request/response vars
 133     std::map<std::string, std::string> vars;
 134     //we have an http req
 135     if (gdu && gdu->which == Z_GDU_HTTP_Request)
 136     {
 137         Z_HTTP_Request *hreq = gdu->u.HTTP_Request;
 138         mp::odr o;
 139         req_phase->rewrite_reqline(o, hreq, vars);
 140         yaz_log(YLOG_LOG, ">> Request headers");
 141         req_phase->rewrite_headers(o, hreq->headers, vars);
 142         req_phase->rewrite_body(o,
 143                                 z_HTTP_header_lookup(hreq->headers,
 144                                                      "Content-Type"),
 145                                 &hreq->content_buf, &hreq->content_len,
 146                                 vars);
 147         package.request() = gdu;
 148     }
 149     package.move();
 150     gdu = package.response().get();
 151     if (gdu && gdu->which == Z_GDU_HTTP_Response)
 152     {
 153         Z_HTTP_Response *hres = gdu->u.HTTP_Response;
 154         yaz_log(YLOG_LOG, "Response code %d", hres->code);
 155         mp::odr o;
 156         yaz_log(YLOG_LOG, "<< Respose headers");
 157         res_phase->rewrite_headers(o, hres->headers, vars);
 158         res_phase->rewrite_body(o,
 159                                 z_HTTP_header_lookup(hres->headers,
 160                                                      "Content-Type"),
 161                                 &hres->content_buf, &hres->content_len,
 162                                 vars);
 163         package.response() = gdu;
 164     }
 165 }
 166
 167 void yf::HttpRewrite::Phase::rewrite_reqline (mp::odr & o,
 168         Z_HTTP_Request *hreq,
 169         std::map<std::string, std::string> & vars) const
 170 {
 171     //rewrite the request line
 172     std::string path;
 173     if (strstr(hreq->path, "http://") == hreq->path)
 174     {
 175         yaz_log(YLOG_LOG, "Path in the method line is absolute, "
 176             "possibly a proxy request");
 177         path += hreq->path;
 178     }
 179     else
 180     {
 181         //TODO what about proto
 182         const char *host = z_HTTP_header_lookup(hreq->headers, "Host");
 183         if (!host)
 184             return;
 185
 186         path += "http://";
 187         path += host;
 188         path += hreq->path;
 189     }
 190
 191     std::list<Content>::const_iterator cit = content_list.begin();
 192     for (; cit != content_list.end(); cit++)
 193         if (cit->type == "headers")
 194             break;
 195
 196     if (cit == content_list.end())
 197         return;
 198
 199     std::list<Within>::const_iterator it = cit->within_list.begin();
 200     for (; it != cit->within_list.end(); it++)
 201         if (it->reqline)
 202         {
 203             yaz_log(YLOG_LOG, "Proxy request URL is %s", path.c_str());
 204             if (it->exec(vars, path, true))
 205             {
 206                 yaz_log(YLOG_LOG, "Rewritten request URL is %s", path.c_str());
 207                 hreq->path = odr_strdup(o, path.c_str());
 208             }
 209         }
 210 }
 211
 212 void yf::HttpRewrite::Phase::rewrite_headers(mp::odr & o,
 213         Z_HTTP_Header *headers,
 214         std::map<std::string, std::string> & vars) const
 215 {
 216     std::list<Content>::const_iterator cit = content_list.begin();
 217     for (; cit != content_list.end(); cit++)
 218         if (cit->type == "headers")
 219             break;
 220
 221     if (cit == content_list.end())
 222         return;
 223
 224     for (Z_HTTP_Header *header = headers; header; header = header->next)
 225     {
 226         std::list<Within>::const_iterator it = cit->within_list.begin();
 227         for (; it != cit->within_list.end(); it++)
 228         {
 229             if (it->header.length() > 0 &&
 230                 yaz_strcasecmp(it->header.c_str(), header->name) == 0)
 231             {
 232                 std::string sheader(header->name);
 233                 sheader += ": ";
 234                 sheader += header->value;
 235
 236                 if (it->exec(vars, sheader, true))
 237                 {
 238                     size_t pos = sheader.find(": ");
 239                     if (pos == std::string::npos)
 240                     {
 241                         yaz_log(YLOG_LOG, "Header malformed during rewrite, ignoring");
 242                         continue;
 243                     }
 244                     header->name = odr_strdup(
 245                         o, sheader.substr(0, pos).c_str());
 246                     header->value = odr_strdup(
 247                         o, sheader.substr(pos + 2, std::string::npos).c_str());
 248                 }
 249             }
 250         }
 251     }
 252 }
 253
 254 void yf::HttpRewrite::Phase::rewrite_body(
 255     mp::odr &o,
 256     const char *content_type,
 257     char **content_buf,
 258     int *content_len,
 259     std::map<std::string, std::string> & vars) const
 260 {
 261     if (*content_len == 0)
 262         return;
 263     std::list<Content>::const_iterator cit = content_list.begin();
 264     for (; cit != content_list.end(); cit++)
 265     {
 266         yaz_log(YLOG_LOG, "rewrite_body: content_type=%s type=%s",
 267                 content_type, cit->type.c_str());
 268         if (cit->type != "headers"
 269             && regex_match(content_type, cit->content_re))
 270             break;
 271     }
 272     if (cit == content_list.end())
 273         return;
 274
 275     int i;
 276     for (i = 0; i < *content_len; i++)
 277         if ((*content_buf)[i] == 0)
 278             return;  // binary content. skip
 279
 280     std::string content(*content_buf, *content_len);
 281     cit->parse(m_verbose, content, vars);
 282     *content_buf = odr_strdup(o, content.c_str());
 283     *content_len = strlen(*content_buf);
 284 }
 285
 286 yf::HttpRewrite::Event::Event(const Content *p,
 287                               std::map<std::string, std::string> & vars
 288     ) : m_content(p), m_vars(vars)
 289 {
 290     m_w = wrbuf_alloc();
 291 }
 292
 293 yf::HttpRewrite::Event::~Event()
 294 {
 295     wrbuf_destroy(m_w);
 296 }
 297
 298 const char *yf::HttpRewrite::Event::result()
 299 {
 300     return wrbuf_cstr(m_w);
 301 }
 302
 303 void yf::HttpRewrite::Event::openTagStart(const char *tag, int tag_len)
 304 {
 305     wrbuf_putc(m_w, '<');
 306     wrbuf_write(m_w, tag, tag_len);
 307
 308     std::string t(tag, tag_len);
 309     std::list<Within>::const_iterator it = m_content->within_list.begin();
 310     for (; it != m_content->within_list.end(); it++)
 311     {
 312         if (it->tag.length() > 0 && yaz_strcasecmp(it->tag.c_str(),
 313                                                    t.c_str()) == 0)
 314         {
 315             std::vector<std::string> attr;
 316             boost::split(attr, it->attr, boost::is_any_of(","));
 317             size_t i;
 318             for (i = 0; i < attr.size(); i++)
 319             {
 320                 if (attr[i].compare("#text") == 0)
 321                 {
 322                     s_within.push(it);
 323                     return;
 324                 }
 325             }
 326         }
 327     }
 328 }
 329
 330 void yf::HttpRewrite::Event::anyTagEnd(const char *tag, int tag_len,
 331                                        int close_it)
 332 {
 333     if (close_it)
 334     {
 335         if (!s_within.empty())
 336         {
 337             std::list<Within>::const_iterator it = s_within.top();
 338             std::string t(tag, tag_len);
 339             if (yaz_strcasecmp(it->tag.c_str(), t.c_str()) == 0)
 340                 s_within.pop();
 341         }
 342     }
 343     if (close_it)
 344         wrbuf_putc(m_w, '/');
 345     wrbuf_putc(m_w, '>');
 346 }
 347
 348 void yf::HttpRewrite::Event::attribute(const char *tag, int tag_len,
 349                                        const char *attr, int attr_len,
 350                                        const char *value, int val_len,
 351                                        const char *sep)
 352 {
 353     std::list<Within>::const_iterator it = m_content->within_list.begin();
 354     bool subst = false;
 355
 356     for (; it != m_content->within_list.end(); it++)
 357     {
 358         std::string t(tag, tag_len);
 359         if (it->tag.length() == 0 ||
 360             yaz_strcasecmp(it->tag.c_str(), t.c_str()) == 0)
 361         {
 362             std::string a(attr, attr_len);
 363             std::vector<std::string> attr;
 364             boost::split(attr, it->attr, boost::is_any_of(","));
 365             size_t i;
 366             for (i = 0; i < attr.size(); i++)
 367             {
 368                 if (attr[i].compare("#text") &&
 369                     yaz_strcasecmp(attr[i].c_str(), a.c_str()) == 0)
 370                     subst = true;
 371             }
 372         }
 373         if (subst)
 374             break;
 375     }
 376
 377     wrbuf_putc(m_w, ' ');
 378     wrbuf_write(m_w, attr, attr_len);
 379     if (value)
 380     {
 381         wrbuf_puts(m_w, "=");
 382         wrbuf_puts(m_w, sep);
 383
 384         std::string output;
 385         if (subst)
 386         {
 387             std::string s(value, val_len);
 388             it->exec(m_vars, s, true);
 389             wrbuf_puts(m_w, s.c_str());
 390         }
 391         else
 392             wrbuf_write(m_w, value, val_len);
 393         wrbuf_puts(m_w, sep);
 394     }
 395 }
 396
 397 void yf::HttpRewrite::Event::closeTag(const char *tag, int tag_len)
 398 {
 399     if (!s_within.empty())
 400     {
 401         std::list<Within>::const_iterator it = s_within.top();
 402         std::string t(tag, tag_len);
 403         if (yaz_strcasecmp(it->tag.c_str(), t.c_str()) == 0)
 404             s_within.pop();
 405     }
 406     wrbuf_puts(m_w, "</");
 407     wrbuf_write(m_w, tag, tag_len);
 408 }
 409
 410 void yf::HttpRewrite::Event::text(const char *value, int len)
 411 {
 412     std::list<Within>::const_iterator it = m_content->within_list.end();
 413     if (!s_within.empty())
 414         it = s_within.top();
 415     if (it != m_content->within_list.end())
 416     {
 417         std::string s(value, len);
 418         it->exec(m_vars, s, false);
 419         wrbuf_puts(m_w, s.c_str());
 420     }
 421     else
 422         wrbuf_write(m_w, value, len);
 423 }
 424
 425 static bool embed_quoted_literal(
 426     std::string &content,
 427     std::map<std::string, std::string> &vars,
 428     mp::filter::HttpRewrite::RulePtr ruleptr)
 429 {
 430     bool replace = false;
 431     std::string res;
 432     const char *cp = content.c_str();
 433     const char *cp0 = cp;
 434     while (*cp)
 435     {
 436         if (*cp == '"' || *cp == '\'')
 437         {
 438             int m = *cp;
 439             cp++;
 440             res.append(cp0, cp - cp0);
 441             cp0 = cp;
 442             while (*cp)
 443             {
 444                 if (cp[-1] != '\\' && *cp == m)
 445                     break;
 446                 if (*cp == '\n')
 447                     break;
 448                 cp++;
 449             }
 450             if (!*cp)
 451                 break;
 452             std::string s(cp0, cp - cp0);
 453             if (ruleptr->test_patterns(vars, s, true))
 454                 replace = true;
 455             cp0 = cp;
 456             res.append(s);
 457         }
 458         else if (*cp == '/' && cp[1] == '/')
 459         {
 460             while (cp[1] && cp[1] != '\n')
 461                 cp++;
 462         }
 463         cp++;
 464     }
 465     res.append(cp0, cp - cp0);
 466     content = res;
 467     return replace;
 468 }
 469
 470 bool yf::HttpRewrite::Within::exec(
 471     std::map<std::string, std::string> & vars,
 472     std::string & txt, bool anchor) const
 473 {
 474     if (type == "quoted-literal")
 475     {
 476         return embed_quoted_literal(txt, vars, rule);
 477     }
 478     else
 479     {
 480         return rule->test_patterns(vars, txt, anchor);
 481     }
 482 }
 483
 484 bool yf::HttpRewrite::Rule::test_patterns(
 485     std::map<std::string, std::string> & vars,
 486     std::string & txt, bool anchor)
 487 {
 488     bool replaces = false;
 489     bool first = anchor;
 490     std::string out;
 491     std::string::const_iterator start, end;
 492     start = txt.begin();
 493     end = txt.end();
 494     while (1)
 495     {
 496         std::list<Replace>::iterator bit = replace_list.end();
 497         {
 498             std::string::const_iterator best_pos = txt.end();
 499             std::list<Replace>::iterator it = replace_list.begin();
 500             for (; it != replace_list.end(); it++)
 501             {
 502                 if (it->start_anchor && !first)
 503                     continue;
 504                 if (regex_search(start, end, it->what, it->re))
 505                 {
 506                     if (it->what[0].first < best_pos)
 507                     {
 508                         best_pos = it->what[0].first;
 509                         bit = it;
 510                     }
 511                 }
 512             }
 513             if (bit == replace_list.end())
 514                 break;
 515         }
 516         first = false;
 517         replaces = true;
 518         size_t i;
 519         for (i = 1; i < bit->what.size(); ++i)
 520         {
 521             //check if the group is named
 522             std::map<int, std::string>::const_iterator git
 523                 = bit->group_index.find(i);
 524             if (git != bit->group_index.end())
 525             {   //it is
 526                 vars[git->second] = bit->what[i];
 527             }
 528
 529         }
 530         //prepare replacement string
 531         std::string rvalue = bit->sub_vars(vars);
 532         yaz_log(YLOG_LOG, "! Rewritten '%s' to '%s'",
 533                 bit->what.str(0).c_str(), rvalue.c_str());
 534         out.append(start, bit->what[0].first);
 535         out.append(rvalue);
 536         start = bit->what[0].second; //move search forward
 537     }
 538     out.append(start, end);
 539     txt = out;
 540     return replaces;
 541 }
 542
 543 void yf::HttpRewrite::Replace::parse_groups(std::string pattern)
 544 {
 545     int gnum = 0;
 546     bool esc = false;
 547     const std::string &str = pattern;
 548     std::string res;
 549     start_anchor = str[0] == '^';
 550     yaz_log(YLOG_LOG, "Parsing groups from '%s'", str.c_str());
 551     for (size_t i = 0; i < str.size(); ++i)
 552     {
 553         res += str[i];
 554         if (!esc && str[i] == '\\')
 555         {
 556             esc = true;
 557             continue;
 558         }
 559         if (!esc && str[i] == '(') //group starts
 560         {
 561             gnum++;
 562             if (i+1 < str.size() && str[i+1] == '?') //group with attrs
 563             {
 564                 i++;
 565                 if (i+1 < str.size() && str[i+1] == ':') //non-capturing
 566                 {
 567                     if (gnum > 0) gnum--;
 568                     res += str[i];
 569                     i++;
 570                     res += str[i];
 571                     continue;
 572                 }
 573                 if (i+1 < str.size() && str[i+1] == 'P') //optional, python
 574                     i++;
 575                 if (i+1 < str.size() && str[i+1] == '<') //named
 576                 {
 577                     i++;
 578                     std::string gname;
 579                     bool term = false;
 580                     while (++i < str.size())
 581                     {
 582                         if (str[i] == '>') { term = true; break; }
 583                         if (!isalnum(str[i]))
 584                             throw mp::filter::FilterException
 585                                 ("Only alphanumeric chars allowed, found "
 586                                  " in '"
 587                                  + str
 588                                  + "' at "
 589                                  + boost::lexical_cast<std::string>(i));
 590                         gname += str[i];
 591                     }
 592                     if (!term)
 593                         throw mp::filter::FilterException
 594                             ("Unterminated group name '" + gname
 595                              + " in '" + str +"'");
 596                     group_index[gnum] = gname;
 597                     yaz_log(YLOG_LOG, "Found named group '%s' at $%d",
 598                             gname.c_str(), gnum);
 599                 }
 600             }
 601         }
 602         esc = false;
 603     }
 604     re = res;
 605 }
 606
 607 std::string yf::HttpRewrite::Replace::sub_vars(
 608     const std::map<std::string, std::string> & vars) const
 609 {
 610     std::string out;
 611     bool esc = false;
 612     const std::string & in = recipe;
 613     for (size_t i = 0; i < in.size(); ++i)
 614     {
 615         if (!esc && in[i] == '\\')
 616         {
 617             esc = true;
 618             continue;
 619         }
 620         if (!esc && in[i] == '$') //var
 621         {
 622             if (i+1 < in.size() && in[i+1] == '{') //ref prefix
 623             {
 624                 ++i;
 625                 std::string name;
 626                 bool term = false;
 627                 while (++i < in.size())
 628                 {
 629                     if (in[i] == '}') { term = true; break; }
 630                     name += in[i];
 631                 }
 632                 if (!term) throw mp::filter::FilterException
 633                     ("Unterminated var ref in '"+in+"' at "
 634                      + boost::lexical_cast<std::string>(i));
 635                 std::map<std::string, std::string>::const_iterator it
 636                     = vars.find(name);
 637                 if (it != vars.end())
 638                 {
 639                     out += it->second;
 640                 }
 641             }
 642             else
 643             {
 644                 throw mp::filter::FilterException
 645                     ("Malformed or trimmed var ref in '"
 646                      +in+"' at "+boost::lexical_cast<std::string>(i));
 647             }
 648             continue;
 649         }
 650         //passthru
 651         out += in[i];
 652         esc = false;
 653     }
 654     return out;
 655 }
 656
 657 yf::HttpRewrite::Phase::Phase() : m_verbose(0)
 658 {
 659 }
 660
 661 void yf::HttpRewrite::Content::parse(
 662     int verbose,
 663     std::string &content,
 664     std::map<std::string, std::string> &vars) const
 665 {
 666     if (type == "html")
 667     {
 668         HTMLParser parser;
 669         Event ev(this, vars);
 670
 671         parser.set_verbose(verbose);
 672
 673         parser.parse(ev, content.c_str());
 674         content = ev.result();
 675     }
 676     if (type == "quoted-literal")
 677     {
 678         quoted_literal(content, vars);
 679     }
 680 }
 681
 682 void yf::HttpRewrite::Content::quoted_literal(
 683     std::string &content,
 684     std::map<std::string, std::string> &vars) const
 685 {
 686     std::list<Within>::const_iterator it = within_list.begin();
 687     if (it != within_list.end())
 688         embed_quoted_literal(content, vars, it->rule);
 689 }
 690
 691 void yf::HttpRewrite::Content::configure(
 692     const xmlNode *ptr, std::map<std::string, RulePtr > &rules)
 693 {
 694     for (; ptr; ptr = ptr->next)
 695     {
 696         if (ptr->type != XML_ELEMENT_NODE)
 697             continue;
 698         if (!strcmp((const char *) ptr->name, "within"))
 699         {
 700             static const char *names[7] =
 701                 { "header", "attr", "tag", "rule", "reqline", "type", 0 };
 702             std::string values[6];
 703             mp::xml::parse_attr(ptr, names, values);
 704             Within w;
 705             w.header = values[0];
 706             w.attr = values[1];
 707             w.tag = values[2];
 708             std::map<std::string,RulePtr>::const_iterator it =
 709                 rules.find(values[3]);
 710             if (it == rules.end())
 711                 throw mp::filter::FilterException
 712                     ("Reference to non-existing rule '" + values[3] +
 713                      "' in http_rewrite filter");
 714             w.rule = it->second;
 715             w.reqline = values[4] == "1";
 716             w.type = values[5];
 717             if (w.type.empty() || w.type == "quoted-literal")
 718                 ;
 719             else
 720                 throw mp::filter::FilterException
 721                     ("within type must be quoted-literal or none in "
 722                      " in http_rewrite filter");
 723             within_list.push_back(w);
 724         }
 725     }
 726 }
 727
 728 void yf::HttpRewrite::configure_phase(const xmlNode *ptr, Phase &phase)
 729 {
 730     static const char *names[2] = { "verbose", 0 };
 731     std::string values[1];
 732     values[0] = "0";
 733     mp::xml::parse_attr(ptr, names, values);
 734
 735     phase.m_verbose = atoi(values[0].c_str());
 736
 737     std::map<std::string, RulePtr > rules;
 738     for (ptr = ptr->children; ptr; ptr = ptr->next)
 739     {
 740         if (ptr->type != XML_ELEMENT_NODE)
 741             continue;
 742         else if (!strcmp((const char *) ptr->name, "rule"))
 743         {
 744             static const char *names[2] = { "name", 0 };
 745             std::string values[1];
 746             values[0] = "default";
 747             mp::xml::parse_attr(ptr, names, values);
 748
 749             RulePtr rule(new Rule);
 750             for (xmlNode *p = ptr->children; p; p = p->next)
 751             {
 752                 if (p->type != XML_ELEMENT_NODE)
 753                     continue;
 754                 if (!strcmp((const char *) p->name, "rewrite"))
 755                 {
 756                     Replace replace;
 757                     std::string from;
 758                     const struct _xmlAttr *attr;
 759                     for (attr = p->properties; attr; attr = attr->next)
 760                     {
 761                         if (!strcmp((const char *) attr->name,  "from"))
 762                             from = mp::xml::get_text(attr->children);
 763                         else if (!strcmp((const char *) attr->name,  "to"))
 764                             replace.recipe = mp::xml::get_text(attr->children);
 765                         else
 766                             throw mp::filter::FilterException
 767                                 ("Bad attribute "
 768                                  + std::string((const char *) attr->name)
 769                                  + " in rewrite section of http_rewrite");
 770                     }
 771                     yaz_log(YLOG_LOG, "Found rewrite rule from '%s' to '%s'",
 772                             from.c_str(), replace.recipe.c_str());
 773                     if (!from.empty())
 774                     {
 775                         replace.parse_groups(from);
 776                         rule->replace_list.push_back(replace);
 777                     }
 778                 }
 779                 else
 780                     throw mp::filter::FilterException
 781                         ("Bad element "
 782                          + std::string((const char *) p->name)
 783                          + " in http_rewrite filter");
 784             }
 785             rules[values[0]] = rule;
 786         }
 787         else if (!strcmp((const char *) ptr->name, "content"))
 788         {
 789             static const char *names[3] =
 790                 { "type", "mime", 0 };
 791             std::string values[2];
 792             mp::xml::parse_attr(ptr, names, values);
 793             if (values[0].empty())
 794             {
 795                     throw mp::filter::FilterException
 796                         ("Missing attribute, type for for element "
 797                          + std::string((const char *) ptr->name)
 798                          + " in http_rewrite filter");
 799             }
 800             Content c;
 801
 802             c.type = values[0];
 803             // if (!values[1].empty())
 804                 c.content_re = values[1];
 805             c.configure(ptr->children, rules);
 806             phase.content_list.push_back(c);
 807         }
 808         else
 809         {
 810             throw mp::filter::FilterException
 811                 ("Bad element "
 812                  + std::string((const char *) ptr->name)
 813                  + " in http_rewrite filter");
 814         }
 815     }
 816 }
 817
 818 void yf::HttpRewrite::configure(const xmlNode * ptr, bool test_only,
 819         const char *path)
 820 {
 821     for (ptr = ptr->children; ptr; ptr = ptr->next)
 822     {
 823         if (ptr->type != XML_ELEMENT_NODE)
 824             continue;
 825         else if (!strcmp((const char *) ptr->name, "request"))
 826         {
 827             configure_phase(ptr, *req_phase);
 828         }
 829         else if (!strcmp((const char *) ptr->name, "response"))
 830         {
 831             configure_phase(ptr, *res_phase);
 832         }
 833         else
 834         {
 835             throw mp::filter::FilterException
 836                 ("Bad element "
 837                  + std::string((const char *) ptr->name)
 838                  + " in http_rewrite1 filter");
 839         }
 840     }
 841 }
 842
 843 static mp::filter::Base* filter_creator()
 844 {
 845     return new mp::filter::HttpRewrite;
 846 }
 847
 848 extern "C" {
 849     struct metaproxy_1_filter_struct metaproxy_1_filter_http_rewrite = {
 850         0,
 851         "http_rewrite",
 852         filter_creator
 853     };
 854 }
 855
 856
 857 /*
 858  * Local variables:
 859  * c-basic-offset: 4
 860  * c-file-style: "Stroustrup"
 861  * indent-tabs-mode: nil
 862  * End:
 863  * vim: shiftwidth=4 tabstop=8 expandtab
 864  */
 865