src/errorpage.cc

   1 /*
   2  * Copyright (C) 1996-2020 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 /* DEBUG: section 04    Error Generation */
  10
  11 #include "squid.h"
  12 #include "AccessLogEntry.h"
  13 #include "cache_cf.h"
  14 #include "clients/forward.h"
  15 #include "comm/Connection.h"
  16 #include "comm/Write.h"
  17 #include "err_detail_type.h"
  18 #include "errorpage.h"
  19 #include "fde.h"
  20 #include "format/Format.h"
  21 #include "fs_io.h"
  22 #include "html_quote.h"
  23 #include "HttpHeaderTools.h"
  24 #include "HttpReply.h"
  25 #include "HttpRequest.h"
  26 #include "MemBuf.h"
  27 #include "MemObject.h"
  28 #include "rfc1738.h"
  29 #include "sbuf/Stream.h"
  30 #include "SquidConfig.h"
  31 #include "SquidTime.h"
  32 #include "Store.h"
  33 #include "tools.h"
  34 #include "wordlist.h"
  35 #if USE_AUTH
  36 #include "auth/UserRequest.h"
  37 #endif
  38 #if USE_OPENSSL
  39 #include "ssl/ErrorDetailManager.h"
  40 #endif
  41
  42 /**
  43  \defgroup ErrorPageInternal Error Page Internals
  44  \ingroup ErrorPageAPI
  45  *
  46  \section ErrorPagesAbstract Abstract:
  47  *   These routines are used to generate error messages to be
  48  *   sent to clients.  The error type is used to select between
  49  *   the various message formats. (formats are stored in the
  50  *   Config.errorDirectory)
  51  */
  52
  53 #if !defined(DEFAULT_SQUID_ERROR_DIR)
  54 /** Where to look for errors if config path fails.
  55  \note Please use ./configure --datadir=/path instead of patching
  56  */
  57 #define DEFAULT_SQUID_ERROR_DIR   DEFAULT_SQUID_DATA_DIR"/errors"
  58 #endif
  59
  60 /// \ingroup ErrorPageInternal
  61 CBDATA_CLASS_INIT(ErrorState);
  62
  63 const SBuf ErrorState::LogformatMagic("@Squid{");
  64
  65 /* local types */
  66
  67 /// an error page created from admin-configurable metadata (e.g. deny_info)
  68 class ErrorDynamicPageInfo {
  69 public:
  70     ErrorDynamicPageInfo(const int anId, const char *aName, const SBuf &aCfgLocation);
  71     ~ErrorDynamicPageInfo() { xfree(page_name); }
  72
  73     /// error_text[] index for response body (unused in redirection responses)
  74     int id;
  75
  76     /// Primary deny_info parameter:
  77     /// * May start with an HTTP status code.
  78     /// * Either a well-known error page name, a filename, or a redirect URL.
  79     char *page_name;
  80
  81     /// admin-configured HTTP Location header value for redirection responses
  82     const char *uri;
  83
  84     /// admin-configured name for the error page template (custom or standard)
  85     const char *filename;
  86
  87     /// deny_info directive position in squid.conf (for reporting)
  88     SBuf cfgLocation;
  89
  90     // XXX: Misnamed. Not just for redirects.
  91     /// admin-configured HTTP status code
  92     Http::StatusCode page_redirect;
  93
  94 private:
  95     // no copying of any kind
  96     ErrorDynamicPageInfo(ErrorDynamicPageInfo &&) = delete;
  97 };
  98
  99 namespace ErrorPage {
 100
 101 /// state and parameters shared by several ErrorState::compile*() methods
 102 class Build
 103 {
 104 public:
 105     SBuf output; ///< compilation result
 106     const char *input = nullptr; ///< template bytes that need to be compiled
 107     bool building_deny_info_url = false; ///< whether we compile deny_info URI
 108     bool allowRecursion = false; ///< whether top-level compile() calls are OK
 109 };
 110
 111 /// pretty-prints error page/deny_info building error
 112 class BuildErrorPrinter
 113 {
 114 public:
 115     BuildErrorPrinter(const SBuf &anInputLocation, int aPage, const char *aMsg, const char *aNear): inputLocation(anInputLocation), page_id(aPage), msg(aMsg), near(aNear) {}
 116
 117     /// reports error details (for admin-visible exceptions and debugging)
 118     std::ostream &print(std::ostream &) const;
 119
 120     /// print() helper to report where the error was found
 121     std::ostream &printLocation(std::ostream &os) const;
 122
 123     /* saved constructor parameters */
 124     const SBuf &inputLocation;
 125     const int page_id;
 126     const char *msg;
 127     const char *near;
 128 };
 129
 130 static inline std::ostream &
 131 operator <<(std::ostream &os, const BuildErrorPrinter &context)
 132 {
 133     return context.print(os);
 134 }
 135
 136 static const char *IsDenyInfoUri(const int page_id);
 137
 138 static void ImportStaticErrorText(const int page_id, const char *text, const SBuf &inputLocation);
 139 static void ValidateStaticError(const int page_id, const SBuf &inputLocation);
 140
 141 } // namespace ErrorPage
 142
 143 /* local constant and vars */
 144
 145 /**
 146  \ingroup ErrorPageInternal
 147  *
 148  \note  hard coded error messages are not appended with %S
 149  *      automagically to give you more control on the format
 150  */
 151 static const struct {
 152     int type;           /* and page_id */
 153     const char *text;
 154 }
 155
 156 error_hard_text[] = {
 157
 158     {
 159         ERR_SQUID_SIGNATURE,
 160         "\n<br>\n"
 161         "<hr>\n"
 162         "<div id=\"footer\">\n"
 163         "Generated %T by %h (%s)\n"
 164         "</div>\n"
 165         "</body></html>\n"
 166     },
 167     {
 168         TCP_RESET,
 169         "reset"
 170     },
 171     {
 172         ERR_SECURE_ACCEPT_FAIL,
 173         "secure accept fail"
 174     },
 175     {
 176         ERR_REQUEST_START_TIMEOUT,
 177         "request start timedout"
 178     },
 179     {
 180         MGR_INDEX,
 181         "mgr_index"
 182     }
 183 };
 184
 185 /// \ingroup ErrorPageInternal
 186 static std::vector<ErrorDynamicPageInfo *> ErrorDynamicPages;
 187
 188 /* local prototypes */
 189
 190 /// \ingroup ErrorPageInternal
 191 static const int error_hard_text_count = sizeof(error_hard_text) / sizeof(*error_hard_text);
 192
 193 /// \ingroup ErrorPageInternal
 194 static char **error_text = NULL;
 195
 196 /// \ingroup ErrorPageInternal
 197 static int error_page_count = 0;
 198
 199 /// \ingroup ErrorPageInternal
 200 static MemBuf error_stylesheet;
 201
 202 static const char *errorFindHardText(err_type type);
 203 static IOCB errorSendComplete;
 204
 205 /// \ingroup ErrorPageInternal
 206 /// manages an error page template
 207 class ErrorPageFile: public TemplateFile
 208 {
 209 public:
 210     ErrorPageFile(const char *name, const err_type code) : TemplateFile(name, code) {}
 211
 212     /// The template text data read from disk
 213     const char *text() { return template_.c_str(); }
 214
 215 protected:
 216     virtual void setDefault() override {
 217         template_ = "Internal Error: Missing Template ";
 218         template_.append(templateName.termedBuf());
 219     }
 220 };
 221
 222 /// \ingroup ErrorPageInternal
 223 err_type &operator++ (err_type &anErr)
 224 {
 225     int tmp = (int)anErr;
 226     anErr = (err_type)(++tmp);
 227     return anErr;
 228 }
 229
 230 /// \ingroup ErrorPageInternal
 231 int operator - (err_type const &anErr, err_type const &anErr2)
 232 {
 233     return (int)anErr - (int)anErr2;
 234 }
 235
 236 /// \return deny_info URL if the given page is a deny_info page with a URL
 237 /// \return nullptr otherwise
 238 static const char *
 239 ErrorPage::IsDenyInfoUri(const int page_id)
 240 {
 241     if (ERR_MAX <= page_id && page_id < error_page_count)
 242         return ErrorDynamicPages.at(page_id - ERR_MAX)->uri; // may be nil
 243     return nullptr;
 244 }
 245
 246 void
 247 errorInitialize(void)
 248 {
 249     using ErrorPage::ImportStaticErrorText;
 250
 251     err_type i;
 252     const char *text;
 253     error_page_count = ERR_MAX + ErrorDynamicPages.size();
 254     error_text = static_cast<char **>(xcalloc(error_page_count, sizeof(char *)));
 255
 256     for (i = ERR_NONE, ++i; i < error_page_count; ++i) {
 257         safe_free(error_text[i]);
 258
 259         if ((text = errorFindHardText(i))) {
 260             /**\par
 261              * Index any hard-coded error text into defaults.
 262              */
 263             static const SBuf builtIn("built-in");
 264             ImportStaticErrorText(i, text, builtIn);
 265
 266         } else if (i < ERR_MAX) {
 267             /**\par
 268              * Index precompiled fixed template files from one of two sources:
 269              *  (a) default language translation directory (error_default_language)
 270              *  (b) admin specified custom directory (error_directory)
 271              */
 272             ErrorPageFile errTmpl(err_type_str[i], i);
 273             errTmpl.loadDefault();
 274             ImportStaticErrorText(i, errTmpl.text(), errTmpl.filename);
 275         } else {
 276             /** \par
 277              * Index any unknown file names used by deny_info.
 278              */
 279             ErrorDynamicPageInfo *info = ErrorDynamicPages.at(i - ERR_MAX);
 280             assert(info && info->id == i && info->page_name);
 281
 282             if (info->filename) {
 283                 /** But only if they are not redirection URL. */
 284                 ErrorPageFile errTmpl(info->filename, ERR_MAX);
 285                 errTmpl.loadDefault();
 286                 ImportStaticErrorText(i, errTmpl.text(), errTmpl.filename);
 287             } else {
 288                 assert(info->uri);
 289                 ErrorPage::ValidateStaticError(i, info->cfgLocation);
 290             }
 291         }
 292     }
 293
 294     error_stylesheet.reset();
 295
 296     // look for and load stylesheet into global MemBuf for it.
 297     if (Config.errorStylesheet) {
 298         ErrorPageFile tmpl("StylesSheet", ERR_MAX);
 299         tmpl.loadFromFile(Config.errorStylesheet);
 300         error_stylesheet.appendf("%s",tmpl.text());
 301     }
 302
 303 #if USE_OPENSSL
 304     Ssl::errorDetailInitialize();
 305 #endif
 306 }
 307
 308 void
 309 errorClean(void)
 310 {
 311     if (error_text) {
 312         int i;
 313
 314         for (i = ERR_NONE + 1; i < error_page_count; ++i)
 315             safe_free(error_text[i]);
 316
 317         safe_free(error_text);
 318     }
 319
 320     while (!ErrorDynamicPages.empty()) {
 321         delete ErrorDynamicPages.back();
 322         ErrorDynamicPages.pop_back();
 323     }
 324
 325     error_page_count = 0;
 326
 327 #if USE_OPENSSL
 328     Ssl::errorDetailClean();
 329 #endif
 330 }
 331
 332 /// \ingroup ErrorPageInternal
 333 static const char *
 334 errorFindHardText(err_type type)
 335 {
 336     int i;
 337
 338     for (i = 0; i < error_hard_text_count; ++i)
 339         if (error_hard_text[i].type == type)
 340             return error_hard_text[i].text;
 341
 342     return NULL;
 343 }
 344
 345 TemplateFile::TemplateFile(const char *name, const err_type code): silent(false), wasLoaded(false), templateName(name), templateCode(code)
 346 {
 347     assert(name);
 348 }
 349
 350 void
 351 TemplateFile::loadDefault()
 352 {
 353     if (loaded()) // already loaded?
 354         return;
 355
 356     /** test error_directory configured location */
 357     if (Config.errorDirectory) {
 358         char path[MAXPATHLEN];
 359         snprintf(path, sizeof(path), "%s/%s", Config.errorDirectory, templateName.termedBuf());
 360         loadFromFile(path);
 361     }
 362
 363 #if USE_ERR_LOCALES
 364     /** test error_default_language location */
 365     if (!loaded() && Config.errorDefaultLanguage) {
 366         if (!tryLoadTemplate(Config.errorDefaultLanguage)) {
 367             debugs(1, (templateCode < TCP_RESET ? DBG_CRITICAL : 3), "Unable to load default error language files. Reset to backups.");
 368         }
 369     }
 370 #endif
 371
 372     /* test default location if failed (templates == English translation base templates) */
 373     if (!loaded()) {
 374         tryLoadTemplate("templates");
 375     }
 376
 377     /* giving up if failed */
 378     if (!loaded()) {
 379         debugs(1, (templateCode < TCP_RESET ? DBG_CRITICAL : 3), "WARNING: failed to find or read error text file " << templateName);
 380         template_.clear();
 381         setDefault();
 382         wasLoaded = true;
 383     }
 384 }
 385
 386 bool
 387 TemplateFile::tryLoadTemplate(const char *lang)
 388 {
 389     assert(lang);
 390
 391     char path[MAXPATHLEN];
 392     /* TODO: prep the directory path string to prevent snprintf ... */
 393     snprintf(path, sizeof(path), "%s/%s/%s",
 394              DEFAULT_SQUID_ERROR_DIR, lang, templateName.termedBuf());
 395     path[MAXPATHLEN-1] = '\0';
 396
 397     if (loadFromFile(path))
 398         return true;
 399
 400 #if HAVE_GLOB
 401     if ( strlen(lang) == 2) {
 402         /* TODO glob the error directory for sub-dirs matching: <tag> '-*'   */
 403         /* use first result. */
 404         debugs(4,2, HERE << "wildcard fallback errors not coded yet.");
 405     }
 406 #endif
 407
 408     return false;
 409 }
 410
 411 bool
 412 TemplateFile::loadFromFile(const char *path)
 413 {
 414     int fd;
 415     char buf[4096];
 416     ssize_t len;
 417
 418     if (loaded()) // already loaded?
 419         return true;
 420
 421     fd = file_open(path, O_RDONLY | O_TEXT);
 422
 423     if (fd < 0) {
 424         /* with dynamic locale negotiation we may see some failures before a success. */
 425         if (!silent && templateCode < TCP_RESET) {
 426             int xerrno = errno;
 427             debugs(4, DBG_CRITICAL, "ERROR: loading file '" << path << "': " << xstrerr(xerrno));
 428         }
 429         wasLoaded = false;
 430         return wasLoaded;
 431     }
 432
 433     template_.clear();
 434     while ((len = FD_READ_METHOD(fd, buf, sizeof(buf))) > 0) {
 435         template_.append(buf, len);
 436     }
 437
 438     if (len < 0) {
 439         int xerrno = errno;
 440         file_close(fd);
 441         debugs(4, DBG_CRITICAL, MYNAME << "ERROR: failed to fully read: '" << path << "': " << xstrerr(xerrno));
 442         wasLoaded = false;
 443         return false;
 444     }
 445
 446     file_close(fd);
 447
 448     filename = SBuf(path);
 449
 450     if (!parse()) {
 451         debugs(4, DBG_CRITICAL, "ERROR: parsing error in template file: " << path);
 452         wasLoaded = false;
 453         return false;
 454     }
 455
 456     wasLoaded = true;
 457     return wasLoaded;
 458 }
 459
 460 bool strHdrAcptLangGetItem(const String &hdr, char *lang, int langLen, size_t &pos)
 461 {
 462     while (pos < hdr.size()) {
 463
 464         /* skip any initial whitespace. */
 465         while (pos < hdr.size() && xisspace(hdr[pos]))
 466             ++pos;
 467
 468         /*
 469          * Header value format:
 470          *  - sequence of whitespace delimited tags
 471          *  - each tag may suffix with ';'.* which we can ignore.
 472          *  - IFF a tag contains only two characters we can wildcard ANY translations matching: <it> '-'? .*
 473          *    with preference given to an exact match.
 474          */
 475         bool invalid_byte = false;
 476         char *dt = lang;
 477         while (pos < hdr.size() && hdr[pos] != ';' && hdr[pos] != ',' && !xisspace(hdr[pos]) && dt < (lang + (langLen -1)) ) {
 478             if (!invalid_byte) {
 479 #if USE_HTTP_VIOLATIONS
 480                 // if accepting violations we may as well accept some broken browsers
 481                 //  which may send us the right code, wrong ISO formatting.
 482                 if (hdr[pos] == '_')
 483                     *dt = '-';
 484                 else
 485 #endif
 486                     *dt = xtolower(hdr[pos]);
 487                 // valid codes only contain A-Z, hyphen (-) and *
 488                 if (*dt != '-' && *dt != '*' && (*dt < 'a' || *dt > 'z') )
 489                     invalid_byte = true;
 490                 else
 491                     ++dt; // move to next destination byte.
 492             }
 493             ++pos;
 494         }
 495         *dt = '\0'; // nul-terminated the filename content string before system use.
 496
 497         // if we terminated the tag on garbage or ';' we need to skip to the next ',' or end of header.
 498         while (pos < hdr.size() && hdr[pos] != ',')
 499             ++pos;
 500
 501         if (pos < hdr.size() && hdr[pos] == ',')
 502             ++pos;
 503
 504         debugs(4, 9, "STATE: lang=" << lang << ", pos=" << pos << ", buf='" << ((pos < hdr.size()) ? hdr.substr(pos,hdr.size()) : "") << "'");
 505
 506         /* if we found anything we might use, try it. */
 507         if (*lang != '\0' && !invalid_byte)
 508             return true;
 509     }
 510     return false;
 511 }
 512
 513 bool
 514 TemplateFile::loadFor(const HttpRequest *request)
 515 {
 516     String hdr;
 517
 518 #if USE_ERR_LOCALES
 519     if (loaded()) // already loaded?
 520         return true;
 521
 522     if (!request || !request->header.getList(Http::HdrType::ACCEPT_LANGUAGE, &hdr))
 523         return false;
 524
 525     char lang[256];
 526     size_t pos = 0; // current parsing position in header string
 527
 528     debugs(4, 6, HERE << "Testing Header: '" << hdr << "'");
 529
 530     while ( strHdrAcptLangGetItem(hdr, lang, 256, pos) ) {
 531
 532         /* wildcard uses the configured default language */
 533         if (lang[0] == '*' && lang[1] == '\0') {
 534             debugs(4, 6, HERE << "Found language '" << lang << "'. Using configured default.");
 535             return false;
 536         }
 537
 538         debugs(4, 6, HERE << "Found language '" << lang << "', testing for available template");
 539
 540         if (tryLoadTemplate(lang)) {
 541             /* store the language we found for the Content-Language reply header */
 542             errLanguage = lang;
 543             break;
 544         } else if (Config.errorLogMissingLanguages) {
 545             debugs(4, DBG_IMPORTANT, "WARNING: Error Pages Missing Language: " << lang);
 546         }
 547     }
 548 #endif
 549
 550     return loaded();
 551 }
 552
 553 ErrorDynamicPageInfo::ErrorDynamicPageInfo(const int anId, const char *aName, const SBuf &aCfgLocation):
 554     id(anId),
 555     page_name(xstrdup(aName)),
 556     uri(nullptr),
 557     filename(nullptr),
 558     cfgLocation(aCfgLocation),
 559     page_redirect(static_cast<Http::StatusCode>(atoi(page_name)))
 560 {
 561     const char *filenameOrUri = nullptr;
 562     if (xisdigit(*page_name)) {
 563         if (const char *statusCodeEnd = strchr(page_name, ':'))
 564             filenameOrUri = statusCodeEnd + 1;
 565     } else {
 566         assert(!page_redirect);
 567         filenameOrUri = page_name;
 568     }
 569
 570     // Guessed uri, filename, or both values may be nil or malformed.
 571     // They are validated later.
 572     if (!page_redirect) {
 573         if (filenameOrUri && strchr(filenameOrUri, ':')) // looks like a URL
 574             uri = filenameOrUri;
 575         else
 576             filename = filenameOrUri;
 577     }
 578     else if (page_redirect/100 == 3) {
 579         // redirects imply a URL
 580         uri = filenameOrUri;
 581     } else {
 582         // non-redirects imply an error page name
 583         filename = filenameOrUri;
 584     }
 585
 586     const auto info = this; // source code change reduction hack
 587     // TODO: Move and refactor to avoid self_destruct()s in reconfigure.
 588
 589     /* WARNING on redirection status:
 590      * 2xx are permitted, but not documented officially.
 591      * - might be useful for serving static files (PAC etc) in special cases
 592      * 3xx require a URL suitable for Location: header.
 593      * - the current design does not allow for a Location: URI as well as a local file template
 594      *   although this possibility is explicitly permitted in the specs.
 595      * 4xx-5xx require a local file template.
 596      * - sending Location: on these codes with no body is invalid by the specs.
 597      * - current result is Squid crashing or XSS problems as dynamic deny_info load random disk files.
 598      * - a future redesign of the file loading may result in loading remote objects sent inline as local body.
 599      */
 600     if (info->page_redirect == Http::scNone)
 601         ; // special case okay.
 602     else if (info->page_redirect < 200 || info->page_redirect > 599) {
 603         // out of range
 604         debugs(0, DBG_CRITICAL, "FATAL: status " << info->page_redirect << " is not valid on '" << page_name << "'");
 605         self_destruct();
 606     } else if ( /* >= 200 && */ info->page_redirect < 300 && strchr(&(page_name[4]), ':')) {
 607         // 2xx require a local template file
 608         debugs(0, DBG_CRITICAL, "FATAL: status " << info->page_redirect << " requires a template on '" << page_name << "'");
 609         self_destruct();
 610     } else if (info->page_redirect >= 300 && info->page_redirect <= 399 && !strchr(&(page_name[4]), ':')) {
 611         // 3xx require an absolute URL
 612         debugs(0, DBG_CRITICAL, "FATAL: status " << info->page_redirect << " requires a URL on '" << page_name << "'");
 613         self_destruct();
 614     } else if (info->page_redirect >= 400 /* && <= 599 */ && strchr(&(page_name[4]), ':')) {
 615         // 4xx/5xx require a local template file
 616         debugs(0, DBG_CRITICAL, "FATAL: status " << info->page_redirect << " requires a template on '" << page_name << "'");
 617         self_destruct();
 618     }
 619     // else okay.
 620 }
 621
 622 /// \ingroup ErrorPageInternal
 623 static int
 624 errorPageId(const char *page_name)
 625 {
 626     for (int i = 0; i < ERR_MAX; ++i) {
 627         if (strcmp(err_type_str[i], page_name) == 0)
 628             return i;
 629     }
 630
 631     for (size_t j = 0; j < ErrorDynamicPages.size(); ++j) {
 632         if (strcmp(ErrorDynamicPages[j]->page_name, page_name) == 0)
 633             return j + ERR_MAX;
 634     }
 635
 636     return ERR_NONE;
 637 }
 638
 639 err_type
 640 errorReservePageId(const char *page_name, const SBuf &cfgLocation)
 641 {
 642     int id = errorPageId(page_name);
 643
 644     if (id == ERR_NONE) {
 645         id = ERR_MAX + ErrorDynamicPages.size();
 646         const auto info = new ErrorDynamicPageInfo(id, page_name, cfgLocation);
 647         ErrorDynamicPages.push_back(info);
 648     }
 649
 650     return (err_type)id;
 651 }
 652
 653 /// \ingroup ErrorPageInternal
 654 const char *
 655 errorPageName(int pageId)
 656 {
 657     if (pageId >= ERR_NONE && pageId < ERR_MAX)     /* common case */
 658         return err_type_str[pageId];
 659
 660     if (pageId >= ERR_MAX && pageId - ERR_MAX < (ssize_t)ErrorDynamicPages.size())
 661         return ErrorDynamicPages[pageId - ERR_MAX]->page_name;
 662
 663     return "ERR_UNKNOWN";   /* should not happen */
 664 }
 665
 666 ErrorState *
 667 ErrorState::NewForwarding(err_type type, HttpRequestPointer &request, const AccessLogEntry::Pointer &ale)
 668 {
 669     const Http::StatusCode status = (request && request->flags.needValidation) ?
 670                                     Http::scGatewayTimeout : Http::scServiceUnavailable;
 671     return new ErrorState(type, status, request.getRaw(), ale);
 672 }
 673
 674 ErrorState::ErrorState(err_type t) :
 675     type(t),
 676     page_id(t),
 677     callback(nullptr)
 678 {
 679 }
 680
 681 ErrorState::ErrorState(err_type t, Http::StatusCode status, HttpRequest * req, const AccessLogEntry::Pointer &anAle) :
 682     ErrorState(t)
 683 {
 684     if (page_id >= ERR_MAX && ErrorDynamicPages[page_id - ERR_MAX]->page_redirect != Http::scNone)
 685         httpStatus = ErrorDynamicPages[page_id - ERR_MAX]->page_redirect;
 686     else
 687         httpStatus = status;
 688
 689     if (req) {
 690         request = req;
 691         src_addr = req->client_addr;
 692     }
 693
 694     ale = anAle;
 695 }
 696
 697 ErrorState::ErrorState(HttpRequest * req, HttpReply *errorReply) :
 698     ErrorState(ERR_RELAY_REMOTE)
 699 {
 700     Must(errorReply);
 701     response_ = errorReply;
 702     httpStatus = errorReply->sline.status();
 703
 704     if (req) {
 705         request = req;
 706         src_addr = req->client_addr;
 707     }
 708 }
 709
 710 void
 711 errorAppendEntry(StoreEntry * entry, ErrorState * err)
 712 {
 713     assert(entry->mem_obj != NULL);
 714     assert (entry->isEmpty());
 715     debugs(4, 4, "Creating an error page for entry " << entry <<
 716            " with errorstate " << err <<
 717            " page id " << err->page_id);
 718
 719     if (entry->store_status != STORE_PENDING) {
 720         debugs(4, 2, "Skipping error page due to store_status: " << entry->store_status);
 721         /*
 722          * If the entry is not STORE_PENDING, then no clients
 723          * care about it, and we don't need to generate an
 724          * error message
 725          */
 726         assert(EBIT_TEST(entry->flags, ENTRY_ABORTED));
 727         assert(entry->mem_obj->nclients == 0);
 728         delete err;
 729         return;
 730     }
 731
 732     if (err->page_id == TCP_RESET) {
 733         if (err->request) {
 734             debugs(4, 2, "RSTing this reply");
 735             err->request->flags.resetTcp = true;
 736         }
 737     }
 738
 739     entry->storeErrorResponse(err->BuildHttpReply());
 740     delete err;
 741 }
 742
 743 void
 744 errorSend(const Comm::ConnectionPointer &conn, ErrorState * err)
 745 {
 746     debugs(4, 3, conn << ", err=" << err);
 747     assert(Comm::IsConnOpen(conn));
 748
 749     HttpReplyPointer rep(err->BuildHttpReply());
 750
 751     MemBuf *mb = rep->pack();
 752     AsyncCall::Pointer call = commCbCall(78, 5, "errorSendComplete",
 753                                          CommIoCbPtrFun(&errorSendComplete, err));
 754     Comm::Write(conn, mb, call);
 755     delete mb;
 756 }
 757
 758 /**
 759  \ingroup ErrorPageAPI
 760  *
 761  * Called by commHandleWrite() after data has been written
 762  * to the client socket.
 763  *
 764  \note If there is a callback, the callback is responsible for
 765  *     closing the FD, otherwise we do it ourselves.
 766  */
 767 static void
 768 errorSendComplete(const Comm::ConnectionPointer &conn, char *, size_t size, Comm::Flag errflag, int, void *data)
 769 {
 770     ErrorState *err = static_cast<ErrorState *>(data);
 771     debugs(4, 3, HERE << conn << ", size=" << size);
 772
 773     if (errflag != Comm::ERR_CLOSING) {
 774         if (err->callback) {
 775             debugs(4, 3, "errorSendComplete: callback");
 776             err->callback(conn->fd, err->callback_data, size);
 777         } else {
 778             debugs(4, 3, "errorSendComplete: comm_close");
 779             conn->close();
 780         }
 781     }
 782
 783     delete err;
 784 }
 785
 786 ErrorState::~ErrorState()
 787 {
 788     safe_free(redirect_url);
 789     safe_free(url);
 790     safe_free(request_hdrs);
 791     wordlistDestroy(&ftp.server_msg);
 792     safe_free(ftp.request);
 793     safe_free(ftp.reply);
 794     safe_free(err_msg);
 795 #if USE_ERR_LOCALES
 796     if (err_language != Config.errorDefaultLanguage)
 797 #endif
 798         safe_free(err_language);
 799 #if USE_OPENSSL
 800     delete detail;
 801 #endif
 802 }
 803
 804 int
 805 ErrorState::Dump(MemBuf * mb)
 806 {
 807     MemBuf str;
 808     char ntoabuf[MAX_IPSTRLEN];
 809
 810     str.reset();
 811     /* email subject line */
 812     str.appendf("CacheErrorInfo - %s", errorPageName(type));
 813     mb->appendf("?subject=%s", rfc1738_escape_part(str.buf));
 814     str.reset();
 815     /* email body */
 816     str.appendf("CacheHost: %s\r\n", getMyHostname());
 817     /* - Err Msgs */
 818     str.appendf("ErrPage: %s\r\n", errorPageName(type));
 819
 820     if (xerrno) {
 821         str.appendf("Err: (%d) %s\r\n", xerrno, strerror(xerrno));
 822     } else {
 823         str.append("Err: [none]\r\n", 13);
 824     }
 825 #if USE_AUTH
 826     if (auth_user_request.getRaw() && auth_user_request->denyMessage())
 827         str.appendf("Auth ErrMsg: %s\r\n", auth_user_request->denyMessage());
 828 #endif
 829     if (dnsError.size() > 0)
 830         str.appendf("DNS ErrMsg: %s\r\n", dnsError.termedBuf());
 831
 832     /* - TimeStamp */
 833     str.appendf("TimeStamp: %s\r\n\r\n", mkrfc1123(squid_curtime));
 834
 835     /* - IP stuff */
 836     str.appendf("ClientIP: %s\r\n", src_addr.toStr(ntoabuf,MAX_IPSTRLEN));
 837
 838     if (request && request->hier.host[0] != '\0') {
 839         str.appendf("ServerIP: %s\r\n", request->hier.host);
 840     }
 841
 842     str.append("\r\n", 2);
 843     /* - HTTP stuff */
 844     str.append("HTTP Request:\r\n", 15);
 845     if (request) {
 846         str.appendf(SQUIDSBUFPH " " SQUIDSBUFPH " %s/%d.%d\n",
 847                     SQUIDSBUFPRINT(request->method.image()),
 848                     SQUIDSBUFPRINT(request->url.path()),
 849                     AnyP::ProtocolType_str[request->http_ver.protocol],
 850                     request->http_ver.major, request->http_ver.minor);
 851         request->header.packInto(&str);
 852     }
 853
 854     str.append("\r\n", 2);
 855     /* - FTP stuff */
 856
 857     if (ftp.request) {
 858         str.appendf("FTP Request: %s\r\n", ftp.request);
 859         str.appendf("FTP Reply: %s\r\n", (ftp.reply? ftp.reply:"[none]"));
 860         str.append("FTP Msg: ", 9);
 861         wordlistCat(ftp.server_msg, &str);
 862         str.append("\r\n", 2);
 863     }
 864
 865     str.append("\r\n", 2);
 866     mb->appendf("&body=%s", rfc1738_escape_part(str.buf));
 867     str.clean();
 868     return 0;
 869 }
 870
 871 /// \ingroup ErrorPageInternal
 872 #define CVT_BUF_SZ 512
 873
 874 void
 875 ErrorState::compileLogformatCode(Build &build)
 876 {
 877     assert(LogformatMagic.cmp(build.input, LogformatMagic.length()) == 0);
 878
 879     try {
 880         const auto logformat = build.input + LogformatMagic.length();
 881
 882         // Logformat supports undocumented "external" encoding specifications
 883         // like [%>h] or "%<a". To preserve the possibility of extending
 884         // @Squid{} syntax to non-logformat sequences, we require logformat
 885         // sequences to start with '%'. This restriction does not limit
 886         // logformat quoting abilities. TODO: Deprecate "external" encoding?
 887         if (*logformat != '%')
 888             throw TexcHere("logformat expressions that do not start with % are not supported");
 889
 890         static MemBuf result;
 891         result.reset();
 892         const auto logformatLen = Format::AssembleOne(logformat, result, ale);
 893         assert(logformatLen > 0);
 894         const auto closure = logformat + logformatLen;
 895         if (*closure != '}')
 896             throw TexcHere("Missing closing brace (})");
 897         build.output.append(result.content(), result.contentSize());
 898         build.input = closure + 1;
 899         return;
 900     } catch (...) {
 901         noteBuildError("Bad @Squid{logformat} sequence", build.input);
 902     }
 903
 904     // we cannot recover reliably so stop interpreting the rest of input
 905     const auto remainingSize = strlen(build.input);
 906     build.output.append(build.input, remainingSize);
 907     build.input += remainingSize;
 908 }
 909
 910 void
 911 ErrorState::compileLegacyCode(Build &build)
 912 {
 913     static MemBuf mb;
 914     const char *p = NULL;   /* takes priority over mb if set */
 915     int do_quote = 1;
 916     int no_urlescape = 0;       /* if true then item is NOT to be further URL-encoded */
 917     char ntoabuf[MAX_IPSTRLEN];
 918
 919     mb.reset();
 920
 921     const auto &building_deny_info_url = build.building_deny_info_url; // a change reduction hack
 922
 923     const auto letter = build.input[1];
 924
 925     switch (letter) {
 926
 927     case 'a':
 928 #if USE_AUTH
 929         if (request && request->auth_user_request)
 930             p = request->auth_user_request->username();
 931         if (!p)
 932 #endif
 933             p = "-";
 934         break;
 935
 936     case 'A':
 937         // TODO: When/if we get ALE here, pass it as well
 938         if (const auto addr = FindListeningPortAddress(request.getRaw(), nullptr))
 939             mb.appendf("%s", addr->toStr(ntoabuf, MAX_IPSTRLEN));
 940         else
 941             p = "-";
 942         break;
 943
 944     case 'b':
 945         mb.appendf("%u", getMyPort());
 946         break;
 947
 948     case 'B':
 949         if (building_deny_info_url) break;
 950         if (request) {
 951             const SBuf &tmp = Ftp::UrlWith2f(request.getRaw());
 952             mb.append(tmp.rawContent(), tmp.length());
 953         } else
 954             p = "[no URL]";
 955         break;
 956
 957     case 'c':
 958         if (building_deny_info_url) break;
 959         p = errorPageName(type);
 960         break;
 961
 962     case 'D':
 963         if (!build.allowRecursion)
 964             p = "%D";  // if recursion is not allowed, do not convert
 965 #if USE_OPENSSL
 966         // currently only SSL error details implemented
 967         else if (detail) {
 968             detail->useRequest(request.getRaw());
 969             const String &errDetail = detail->toString();
 970             if (errDetail.size() > 0) {
 971                 const auto compiledDetail = compileBody(errDetail.termedBuf(), false);
 972                 mb.append(compiledDetail.rawContent(), compiledDetail.length());
 973                 do_quote = 0;
 974             }
 975         }
 976 #endif
 977         if (!mb.contentSize())
 978             mb.append("[No Error Detail]", 17);
 979         break;
 980
 981     case 'e':
 982         mb.appendf("%d", xerrno);
 983         break;
 984
 985     case 'E':
 986         if (xerrno)
 987             mb.appendf("(%d) %s", xerrno, strerror(xerrno));
 988         else
 989             mb.append("[No Error]", 10);
 990         break;
 991
 992     case 'f':
 993         if (building_deny_info_url) break;
 994         /* FTP REQUEST LINE */
 995         if (ftp.request)
 996             p = ftp.request;
 997         else
 998             p = "nothing";
 999         break;
1000
1001     case 'F':
1002         if (building_deny_info_url) break;
1003         /* FTP REPLY LINE */
1004         if (ftp.reply)
1005             p = ftp.reply;
1006         else
1007             p = "nothing";
1008         break;
1009
1010     case 'g':
1011         if (building_deny_info_url) break;
1012         /* FTP SERVER RESPONSE */
1013         if (ftp.listing) {
1014             mb.append(ftp.listing->content(), ftp.listing->contentSize());
1015             do_quote = 0;
1016         } else if (ftp.server_msg) {
1017             wordlistCat(ftp.server_msg, &mb);
1018         }
1019         break;
1020
1021     case 'h':
1022         mb.appendf("%s", getMyHostname());
1023         break;
1024
1025     case 'H':
1026         if (request) {
1027             if (request->hier.host[0] != '\0') // if non-empty string.
1028                 p = request->hier.host;
1029             else
1030                 p = request->url.host();
1031         } else if (!building_deny_info_url)
1032             p = "[unknown host]";
1033         break;
1034
1035     case 'i':
1036         mb.appendf("%s", src_addr.toStr(ntoabuf,MAX_IPSTRLEN));
1037         break;
1038
1039     case 'I':
1040         if (request && request->hier.tcpServer)
1041             p = request->hier.tcpServer->remote.toStr(ntoabuf,MAX_IPSTRLEN);
1042         else if (!building_deny_info_url)
1043             p = "[unknown]";
1044         break;
1045
1046     case 'l':
1047         if (building_deny_info_url) break;
1048         mb.append(error_stylesheet.content(), error_stylesheet.contentSize());
1049         do_quote = 0;
1050         break;
1051
1052     case 'L':
1053         if (building_deny_info_url) break;
1054         if (Config.errHtmlText) {
1055             mb.appendf("%s", Config.errHtmlText);
1056             do_quote = 0;
1057         } else
1058             p = "[not available]";
1059         break;
1060
1061     case 'm':
1062         if (building_deny_info_url) break;
1063 #if USE_AUTH
1064         if (auth_user_request.getRaw())
1065             p = auth_user_request->denyMessage("[not available]");
1066         else
1067             p = "[not available]";
1068 #else
1069         p = "-";
1070 #endif
1071         break;
1072
1073     case 'M':
1074         if (request) {
1075             const SBuf &m = request->method.image();
1076             mb.append(m.rawContent(), m.length());
1077         } else if (!building_deny_info_url)
1078             p = "[unknown method]";
1079         break;
1080
1081     case 'O':
1082         if (!building_deny_info_url)
1083             do_quote = 0;
1084     case 'o':
1085         p = request ? request->extacl_message.termedBuf() : external_acl_message;
1086         if (!p && !building_deny_info_url)
1087             p = "[not available]";
1088         break;
1089
1090     case 'p':
1091         if (request) {
1092             mb.appendf("%u", request->url.port());
1093         } else if (!building_deny_info_url) {
1094             p = "[unknown port]";
1095         }
1096         break;
1097
1098     case 'P':
1099         if (request) {
1100             const SBuf &m = request->url.getScheme().image();
1101             mb.append(m.rawContent(), m.length());
1102         } else if (!building_deny_info_url) {
1103             p = "[unknown protocol]";
1104         }
1105         break;
1106
1107     case 'R':
1108         if (building_deny_info_url) {
1109             if (request != NULL) {
1110                 const SBuf &tmp = request->url.path();
1111                 mb.append(tmp.rawContent(), tmp.length());
1112                 no_urlescape = 1;
1113             } else
1114                 p = "[no request]";
1115             break;
1116         }
1117         if (request) {
1118             mb.appendf(SQUIDSBUFPH " " SQUIDSBUFPH " %s/%d.%d\n",
1119                        SQUIDSBUFPRINT(request->method.image()),
1120                        SQUIDSBUFPRINT(request->url.path()),
1121                        AnyP::ProtocolType_str[request->http_ver.protocol],
1122                        request->http_ver.major, request->http_ver.minor);
1123             request->header.packInto(&mb, true); //hide authorization data
1124         } else if (request_hdrs) {
1125             p = request_hdrs;
1126         } else {
1127             p = "[no request]";
1128         }
1129         break;
1130
1131     case 's':
1132         /* for backward compat we make %s show the full URL. Drop this in some future release. */
1133         if (building_deny_info_url) {
1134             if (request) {
1135                 const SBuf &tmp = request->effectiveRequestUri();
1136                 mb.append(tmp.rawContent(), tmp.length());
1137             } else
1138                 p = url;
1139             debugs(0, DBG_CRITICAL, "WARNING: deny_info now accepts coded tags. Use %u to get the full URL instead of %s");
1140         } else
1141             p = visible_appname_string;
1142         break;
1143
1144     case 'S':
1145         if (building_deny_info_url) {
1146             p = visible_appname_string;
1147             break;
1148         }
1149         /* signature may contain %-escapes, recursion */
1150         if (page_id != ERR_SQUID_SIGNATURE) {
1151             const int saved_id = page_id;
1152             page_id = ERR_SQUID_SIGNATURE;
1153             const auto signature = buildBody();
1154             mb.append(signature.rawContent(), signature.length());
1155             page_id = saved_id;
1156             do_quote = 0;
1157         } else {
1158             /* wow, somebody put %S into ERR_SIGNATURE, stop recursion */
1159             p = "[%S]";
1160         }
1161         break;
1162
1163     case 't':
1164         mb.appendf("%s", Time::FormatHttpd(squid_curtime));
1165         break;
1166
1167     case 'T':
1168         mb.appendf("%s", mkrfc1123(squid_curtime));
1169         break;
1170
1171     case 'U':
1172         /* Using the fake-https version of absolute-URI so error pages see https:// */
1173         /* even when the url-path cannot be shown as more than '*' */
1174         if (request)
1175             p = urlCanonicalFakeHttps(request.getRaw());
1176         else if (url)
1177             p = url;
1178         else if (!building_deny_info_url)
1179             p = "[no URL]";
1180         break;
1181
1182     case 'u':
1183         if (request) {
1184             const SBuf &tmp = request->effectiveRequestUri();
1185             mb.append(tmp.rawContent(), tmp.length());
1186         } else if (url)
1187             p = url;
1188         else if (!building_deny_info_url)
1189             p = "[no URL]";
1190         break;
1191
1192     case 'w':
1193         if (Config.adminEmail)
1194             mb.appendf("%s", Config.adminEmail);
1195         else if (!building_deny_info_url)
1196             p = "[unknown]";
1197         break;
1198
1199     case 'W':
1200         if (building_deny_info_url) break;
1201         if (Config.adminEmail && Config.onoff.emailErrData)
1202             Dump(&mb);
1203         no_urlescape = 1;
1204         break;
1205
1206     case 'x':
1207 #if USE_OPENSSL
1208         if (detail)
1209             mb.appendf("%s", detail->errorName());
1210         else
1211 #endif
1212             if (!building_deny_info_url)
1213                 p = "[Unknown Error Code]";
1214         break;
1215
1216     case 'z':
1217         if (building_deny_info_url) break;
1218         if (dnsError.size() > 0)
1219             p = dnsError.termedBuf();
1220         else if (ftp.cwd_msg)
1221             p = ftp.cwd_msg;
1222         else
1223             p = "[unknown]";
1224         break;
1225
1226     case 'Z':
1227         if (building_deny_info_url) break;
1228         if (err_msg)
1229             p = err_msg;
1230         else
1231             p = "[unknown]";
1232         break;
1233
1234     case '%':
1235         p = "%";
1236         break;
1237
1238     default:
1239         if (building_deny_info_url)
1240             bypassBuildErrorXXX("Unsupported deny_info %code", build.input);
1241         else if (letter != ';')
1242             bypassBuildErrorXXX("Unsupported error page %code", build.input);
1243         // else too many "font-size: 100%;" template errors to report
1244
1245         mb.append(build.input, 2);
1246         do_quote = 0;
1247         break;
1248     }
1249
1250     if (!p)
1251         p = mb.buf;     /* do not use mb after this assignment! */
1252
1253     assert(p);
1254
1255     debugs(4, 3, "%" << letter << " --> '" << p << "'" );
1256
1257     if (do_quote)
1258         p = html_quote(p);
1259
1260     if (building_deny_info_url && !no_urlescape)
1261         p = rfc1738_escape_part(p);
1262
1263     // TODO: Optimize by replacing mb with direct build.output usage.
1264     build.output.append(p, strlen(p));
1265     build.input += 2;
1266 }
1267
1268 void
1269 ErrorState::validate()
1270 {
1271     if (const auto urlTemplate = ErrorPage::IsDenyInfoUri(page_id)) {
1272         (void)compile(urlTemplate, true, true);
1273     } else {
1274         assert(page_id > ERR_NONE);
1275         assert(page_id < error_page_count);
1276         (void)compileBody(error_text[page_id], true);
1277     }
1278 }
1279
1280 HttpReply *
1281 ErrorState::BuildHttpReply()
1282 {
1283     if (response_)
1284         return response_.getRaw();
1285
1286     HttpReply *rep = new HttpReply;
1287     const char *name = errorPageName(page_id);
1288     /* no LMT for error pages; error pages expire immediately */
1289
1290     if (const auto urlTemplate = ErrorPage::IsDenyInfoUri(page_id)) {
1291         /* Redirection */
1292         Http::StatusCode status = Http::scFound;
1293         // Use configured 3xx reply status if set.
1294         if (name[0] == '3')
1295             status = httpStatus;
1296         else {
1297             // Use 307 for HTTP/1.1 non-GET/HEAD requests.
1298             if (request && request->method != Http::METHOD_GET && request->method != Http::METHOD_HEAD && request->http_ver >= Http::ProtocolVersion(1,1))
1299                 status = Http::scTemporaryRedirect;
1300         }
1301
1302         rep->setHeaders(status, NULL, "text/html;charset=utf-8", 0, 0, -1);
1303
1304         if (request) {
1305             auto location = compile(urlTemplate, true, true);
1306             rep->header.putStr(Http::HdrType::LOCATION, location.c_str());
1307         }
1308
1309         httpHeaderPutStrf(&rep->header, Http::HdrType::X_SQUID_ERROR, "%d %s", httpStatus, "Access Denied");
1310     } else {
1311         const auto body = buildBody();
1312         rep->setHeaders(httpStatus, NULL, "text/html;charset=utf-8", body.length(), 0, -1);
1313         /*
1314          * include some information for downstream caches. Implicit
1315          * replaceable content. This isn't quite sufficient. xerrno is not
1316          * necessarily meaningful to another system, so we really should
1317          * expand it. Additionally, we should identify ourselves. Someone
1318          * might want to know. Someone _will_ want to know OTOH, the first
1319          * X-CACHE-MISS entry should tell us who.
1320          */
1321         httpHeaderPutStrf(&rep->header, Http::HdrType::X_SQUID_ERROR, "%s %d", name, xerrno);
1322
1323 #if USE_ERR_LOCALES
1324         /*
1325          * If error page auto-negotiate is enabled in any way, send the Vary.
1326          * RFC 2616 section 13.6 and 14.44 says MAY and SHOULD do this.
1327          * We have even better reasons though:
1328          * see http://wiki.squid-cache.org/KnowledgeBase/VaryNotCaching
1329          */
1330         if (!Config.errorDirectory) {
1331             /* We 'negotiated' this ONLY from the Accept-Language. */
1332             rep->header.delById(Http::HdrType::VARY);
1333             rep->header.putStr(Http::HdrType::VARY, "Accept-Language");
1334         }
1335
1336         /* add the Content-Language header according to RFC section 14.12 */
1337         if (err_language) {
1338             rep->header.putStr(Http::HdrType::CONTENT_LANGUAGE, err_language);
1339         } else
1340 #endif /* USE_ERROR_LOCALES */
1341         {
1342             /* default templates are in English */
1343             /* language is known unless error_directory override used */
1344             if (!Config.errorDirectory)
1345                 rep->header.putStr(Http::HdrType::CONTENT_LANGUAGE, "en");
1346         }
1347
1348         rep->body.set(body);
1349     }
1350
1351     // Make sure error codes get back to the client side for logging and
1352     // error tracking.
1353     if (request) {
1354         int edc = ERR_DETAIL_NONE; // error detail code
1355 #if USE_OPENSSL
1356         if (detail)
1357             edc = detail->errorNo();
1358         else
1359 #endif
1360             if (detailCode)
1361                 edc = detailCode;
1362             else
1363                 edc = xerrno;
1364         request->detailError(type, edc);
1365     }
1366
1367     return rep;
1368 }
1369
1370 SBuf
1371 ErrorState::buildBody()
1372 {
1373     assert(page_id > ERR_NONE && page_id < error_page_count);
1374
1375 #if USE_ERR_LOCALES
1376     /** error_directory option in squid.conf overrides translations.
1377      * Custom errors are always found either in error_directory or the templates directory.
1378      * Otherwise locate the Accept-Language header
1379      */
1380     if (!Config.errorDirectory && page_id < ERR_MAX) {
1381         if (err_language && err_language != Config.errorDefaultLanguage)
1382             safe_free(err_language);
1383
1384         ErrorPageFile localeTmpl(err_type_str[page_id], static_cast<err_type>(page_id));
1385         if (localeTmpl.loadFor(request.getRaw())) {
1386             inputLocation = localeTmpl.filename;
1387             assert(localeTmpl.language());
1388             err_language = xstrdup(localeTmpl.language());
1389             return compileBody(localeTmpl.text(), true);
1390         }
1391     }
1392 #endif /* USE_ERR_LOCALES */
1393
1394     /** \par
1395      * If client-specific error templates are not enabled or available.
1396      * fall back to the old style squid.conf settings.
1397      */
1398 #if USE_ERR_LOCALES
1399     if (!Config.errorDirectory)
1400         err_language = Config.errorDefaultLanguage;
1401 #endif
1402     debugs(4, 2, "No existing error page language negotiated for " << errorPageName(page_id) << ". Using default error file.");
1403     return compileBody(error_text[page_id], true);
1404 }
1405
1406 SBuf
1407 ErrorState::compileBody(const char *input, bool allowRecursion)
1408 {
1409     return compile(input, false, allowRecursion);
1410 }
1411
1412 SBuf
1413 ErrorState::compile(const char *input, bool building_deny_info_url, bool allowRecursion)
1414 {
1415     assert(input);
1416
1417     Build build;
1418     build.building_deny_info_url = building_deny_info_url;
1419     build.allowRecursion = allowRecursion;
1420     build.input = input;
1421
1422     auto blockStart = build.input;
1423     while (const auto letter = *build.input) {
1424         if (letter == '%') {
1425             build.output.append(blockStart, build.input - blockStart);
1426             compileLegacyCode(build);
1427             blockStart = build.input;
1428         }
1429         else if (letter == '@' && LogformatMagic.cmp(build.input, LogformatMagic.length()) == 0) {
1430             build.output.append(blockStart, build.input - blockStart);
1431             compileLogformatCode(build);
1432             blockStart = build.input;
1433         } else {
1434             ++build.input;
1435         }
1436     }
1437     build.output.append(blockStart, build.input - blockStart);
1438     return build.output;
1439 }
1440
1441 /// react to a compile() error
1442 /// \param msg  description of what went wrong
1443 /// \param near  approximate start of the problematic input
1444 /// \param  forceBypass whether detection of this error was introduced late,
1445 /// after old configurations containing this error could have been
1446 /// successfully validated and deployed (i.e. the admin may not be
1447 /// able to fix this newly detected but old problem quickly)
1448 void
1449 ErrorState::noteBuildError_(const char *msg, const char *near, const bool forceBypass)
1450 {
1451     using ErrorPage::BuildErrorPrinter;
1452     const auto runtime = !starting_up;
1453     if (runtime || forceBypass) {
1454         // swallow this problem because the admin may not be (and/or the page
1455         // building code is not) ready to handle throwing consequences
1456
1457         static unsigned int seenErrors = 0;
1458         ++seenErrors;
1459
1460         const auto debugLevel =
1461             (seenErrors > 100) ? DBG_DATA:
1462             (starting_up || reconfiguring) ? DBG_CRITICAL:
1463             3; // most other errors have been reported as configuration errors
1464
1465         // Error fatality depends on the error context: Reconfiguration errors
1466         // are, like startup ones, DBG_CRITICAL but will never become FATAL.
1467         if (starting_up && seenErrors <= 10)
1468             debugs(4, debugLevel, "WARNING: The following configuration error will be fatal in future Squid versions");
1469
1470         debugs(4, debugLevel, "ERROR: " << BuildErrorPrinter(inputLocation, page_id, msg, near));
1471     } else {
1472         throw TexcHere(ToSBuf(BuildErrorPrinter(inputLocation, page_id, msg, near)));
1473     }
1474 }
1475
1476 /* ErrorPage::BuildErrorPrinter */
1477
1478 std::ostream &
1479 ErrorPage::BuildErrorPrinter::printLocation(std::ostream &os) const {
1480     if (!inputLocation.isEmpty())
1481         return os << inputLocation;
1482
1483     if (page_id < ERR_NONE || page_id >= error_page_count)
1484         return os << "[error page " << page_id << "]"; // should not happen
1485
1486     if (page_id < ERR_MAX)
1487         return os << err_type_str[page_id];
1488
1489     return os << "deny_info " << ErrorDynamicPages.at(page_id - ERR_MAX)->page_name;
1490 }
1491
1492 std::ostream &
1493 ErrorPage::BuildErrorPrinter::print(std::ostream &os) const {
1494     printLocation(os) << ": " << msg << " near ";
1495
1496     // TODO: Add support for prefix printing to Raw
1497     const size_t maxContextLength = 15; // plus "..."
1498     if (strlen(near) > maxContextLength) {
1499         os.write(near, maxContextLength);
1500         os << "...";
1501     } else {
1502         os << near;
1503     }
1504
1505     // XXX: We should not be converting (inner) exception to text if we are
1506     // going to throw again. See "add arbitrary (re)thrower-supplied details"
1507     // TODO in TextException.h for a long-term in-catcher solution.
1508     if (std::current_exception())
1509         os << "\n    additional info: " << CurrentException;
1510
1511     return os;
1512 }
1513
1514 /// add error page template to the global index
1515 static void
1516 ErrorPage::ImportStaticErrorText(const int page_id, const char *text, const SBuf &inputLocation)
1517 {
1518     assert(!error_text[page_id]);
1519     error_text[page_id] = xstrdup(text);
1520     ValidateStaticError(page_id, inputLocation);
1521 }
1522
1523 /// validate static error page
1524 static void
1525 ErrorPage::ValidateStaticError(const int page_id, const SBuf &inputLocation)
1526 {
1527     // Supplying nil ALE pointer limits validation to logformat %code
1528     // recognition by Format::Token::parse(). This is probably desirable
1529     // because actual %code assembly is slow and should not affect validation
1530     // when our ALE cannot have any real data (this code is not associated
1531     // with any real transaction).
1532     ErrorState anErr(err_type(page_id), Http::scNone, nullptr, nullptr);
1533     anErr.inputLocation = inputLocation;
1534     anErr.validate();
1535 }
1536