src/errorpage.cc

   1 /*
   2  * Copyright (C) 1996-2023 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 "error/Detail.h"
  18 #include "error/SysErrorDetail.h"
  19 #include "errorpage.h"
  20 #include "fde.h"
  21 #include "format/Format.h"
  22 #include "fs_io.h"
  23 #include "html_quote.h"
  24 #include "HttpHeaderTools.h"
  25 #include "HttpReply.h"
  26 #include "HttpRequest.h"
  27 #include "MemBuf.h"
  28 #include "MemObject.h"
  29 #include "rfc1738.h"
  30 #include "sbuf/Stream.h"
  31 #include "SquidConfig.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 #include <array>
  43
  44 /**
  45  \defgroup ErrorPageInternal Error Page Internals
  46  \ingroup ErrorPageAPI
  47  *
  48  \section ErrorPagesAbstract Abstract:
  49  *   These routines are used to generate error messages to be
  50  *   sent to clients.  The error type is used to select between
  51  *   the various message formats. (formats are stored in the
  52  *   Config.errorDirectory)
  53  */
  54
  55 #if !defined(DEFAULT_SQUID_ERROR_DIR)
  56 /** Where to look for errors if config path fails.
  57  \note Please use ./configure --datadir=/path instead of patching
  58  */
  59 #define DEFAULT_SQUID_ERROR_DIR   DEFAULT_SQUID_DATA_DIR"/errors"
  60 #endif
  61
  62 /// \ingroup ErrorPageInternal
  63 CBDATA_CLASS_INIT(ErrorState);
  64
  65 const SBuf ErrorState::LogformatMagic("@Squid{");
  66
  67 /* local types */
  68
  69 /// an error page created from admin-configurable metadata (e.g. deny_info)
  70 class ErrorDynamicPageInfo {
  71 public:
  72     ErrorDynamicPageInfo(const int anId, const char *aName, const SBuf &aCfgLocation);
  73     ~ErrorDynamicPageInfo() { xfree(page_name); }
  74
  75     /// error_text[] index for response body (unused in redirection responses)
  76     int id;
  77
  78     /// Primary deny_info parameter:
  79     /// * May start with an HTTP status code.
  80     /// * Either a well-known error page name, a filename, or a redirect URL.
  81     char *page_name;
  82
  83     /// admin-configured HTTP Location header value for redirection responses
  84     const char *uri;
  85
  86     /// admin-configured name for the error page template (custom or standard)
  87     const char *filename;
  88
  89     /// deny_info directive position in squid.conf (for reporting)
  90     SBuf cfgLocation;
  91
  92     // XXX: Misnamed. Not just for redirects.
  93     /// admin-configured HTTP status code
  94     Http::StatusCode page_redirect;
  95
  96 private:
  97     // no copying of any kind
  98     ErrorDynamicPageInfo(ErrorDynamicPageInfo &&) = delete;
  99 };
 100
 101 namespace ErrorPage {
 102
 103 /// state and parameters shared by several ErrorState::compile*() methods
 104 class Build
 105 {
 106 public:
 107     SBuf output; ///< compilation result
 108     const char *input = nullptr; ///< template bytes that need to be compiled
 109     bool building_deny_info_url = false; ///< whether we compile deny_info URI
 110     bool allowRecursion = false; ///< whether top-level compile() calls are OK
 111 };
 112
 113 /// pretty-prints error page/deny_info building error
 114 class BuildErrorPrinter
 115 {
 116 public:
 117     BuildErrorPrinter(const SBuf &anInputLocation, int aPage, const char *aMsg, const char *aNear): inputLocation(anInputLocation), page_id(aPage), msg(aMsg), near(aNear) {}
 118
 119     /// reports error details (for admin-visible exceptions and debugging)
 120     std::ostream &print(std::ostream &) const;
 121
 122     /// print() helper to report where the error was found
 123     std::ostream &printLocation(std::ostream &os) const;
 124
 125     /* saved constructor parameters */
 126     const SBuf &inputLocation;
 127     const int page_id;
 128     const char *msg;
 129     const char *near;
 130 };
 131
 132 static inline std::ostream &
 133 operator <<(std::ostream &os, const BuildErrorPrinter &context)
 134 {
 135     return context.print(os);
 136 }
 137
 138 static const char *IsDenyInfoUri(const int page_id);
 139
 140 static void ImportStaticErrorText(const int page_id, const char *text, const SBuf &inputLocation);
 141 static void ValidateStaticError(const int page_id, const SBuf &inputLocation);
 142
 143 } // namespace ErrorPage
 144
 145 /* local constant and vars */
 146
 147 /// an error page (or a part of an error page) with hard-coded template text
 148 class HardCodedError {
 149 public:
 150     err_type type; ///< identifies the error (or a special error template part)
 151     const char *text; ///< a string literal containing the error template
 152 };
 153
 154 /// error messages that cannot be configured/customized externally
 155 static const std::array<HardCodedError, 7> HardCodedErrors = {
 156     {
 157         {
 158             ERR_SQUID_SIGNATURE,
 159             "\n<br>\n"
 160             "<hr>\n"
 161             "<div id=\"footer\">\n"
 162             "Generated %T by %h (%s)\n"
 163             "</div>\n"
 164             "</body></html>\n"
 165         },
 166         {
 167             TCP_RESET,
 168             "reset"
 169         },
 170         {
 171             ERR_CLIENT_GONE,
 172             "unexpected client disconnect"
 173         },
 174         {
 175             ERR_SECURE_ACCEPT_FAIL,
 176             "secure accept fail"
 177         },
 178         {
 179             ERR_REQUEST_START_TIMEOUT,
 180             "request start timedout"
 181         },
 182         {
 183             ERR_REQUEST_PARSE_TIMEOUT,
 184             "request parse timedout"
 185         },
 186         {
 187             ERR_RELAY_REMOTE,
 188             "relay server response"
 189         }
 190     }
 191 };
 192
 193 /// \ingroup ErrorPageInternal
 194 static std::vector<ErrorDynamicPageInfo *> ErrorDynamicPages;
 195
 196 /* local prototypes */
 197
 198 /// \ingroup ErrorPageInternal
 199 static char **error_text = nullptr;
 200
 201 /// \ingroup ErrorPageInternal
 202 static int error_page_count = 0;
 203
 204 /// \ingroup ErrorPageInternal
 205 static MemBuf error_stylesheet;
 206
 207 static const char *errorFindHardText(err_type type);
 208 static IOCB errorSendComplete;
 209
 210 /// \ingroup ErrorPageInternal
 211 /// manages an error page template
 212 class ErrorPageFile: public TemplateFile
 213 {
 214 public:
 215     ErrorPageFile(const char *name, const err_type code) : TemplateFile(name, code) {}
 216
 217     /// The template text data read from disk
 218     const char *text() { return template_.c_str(); }
 219
 220 protected:
 221     void setDefault() override {
 222         template_ = "Internal Error: Missing Template ";
 223         template_.append(templateName.termedBuf());
 224     }
 225 };
 226
 227 /// \ingroup ErrorPageInternal
 228 static err_type &
 229 operator++ (err_type &anErr)
 230 {
 231     int tmp = (int)anErr;
 232     anErr = (err_type)(++tmp);
 233     return anErr;
 234 }
 235
 236 /// \ingroup ErrorPageInternal
 237 static int
 238 operator -(err_type const &anErr, err_type const &anErr2)
 239 {
 240     return (int)anErr - (int)anErr2;
 241 }
 242
 243 /// \return deny_info URL if the given page is a deny_info page with a URL
 244 /// \return nullptr otherwise
 245 static const char *
 246 ErrorPage::IsDenyInfoUri(const int page_id)
 247 {
 248     if (ERR_MAX <= page_id && page_id < error_page_count)
 249         return ErrorDynamicPages.at(page_id - ERR_MAX)->uri; // may be nil
 250     return nullptr;
 251 }
 252
 253 void
 254 errorInitialize(void)
 255 {
 256     using ErrorPage::ImportStaticErrorText;
 257
 258     err_type i;
 259     const char *text;
 260     error_page_count = ERR_MAX + ErrorDynamicPages.size();
 261     error_text = static_cast<char **>(xcalloc(error_page_count, sizeof(char *)));
 262
 263     for (i = ERR_NONE, ++i; i < error_page_count; ++i) {
 264         safe_free(error_text[i]);
 265
 266         if ((text = errorFindHardText(i))) {
 267             /**\par
 268              * Index any hard-coded error text into defaults.
 269              */
 270             static const SBuf builtIn("built-in");
 271             ImportStaticErrorText(i, text, builtIn);
 272
 273         } else if (i < ERR_MAX) {
 274             /**\par
 275              * Index precompiled fixed template files from one of two sources:
 276              *  (a) default language translation directory (error_default_language)
 277              *  (b) admin specified custom directory (error_directory)
 278              */
 279             ErrorPageFile errTmpl(err_type_str[i], i);
 280             errTmpl.loadDefault();
 281             ImportStaticErrorText(i, errTmpl.text(), errTmpl.filename);
 282         } else {
 283             /** \par
 284              * Index any unknown file names used by deny_info.
 285              */
 286             ErrorDynamicPageInfo *info = ErrorDynamicPages.at(i - ERR_MAX);
 287             assert(info && info->id == i && info->page_name);
 288
 289             if (info->filename) {
 290                 /** But only if they are not redirection URL. */
 291                 ErrorPageFile errTmpl(info->filename, ERR_MAX);
 292                 errTmpl.loadDefault();
 293                 ImportStaticErrorText(i, errTmpl.text(), errTmpl.filename);
 294             } else {
 295                 assert(info->uri);
 296                 ErrorPage::ValidateStaticError(i, info->cfgLocation);
 297             }
 298         }
 299     }
 300
 301     error_stylesheet.reset();
 302
 303     // look for and load stylesheet into global MemBuf for it.
 304     if (Config.errorStylesheet) {
 305         ErrorPageFile tmpl("StylesSheet", ERR_MAX);
 306         tmpl.loadFromFile(Config.errorStylesheet);
 307         error_stylesheet.appendf("%s",tmpl.text());
 308     }
 309
 310 #if USE_OPENSSL
 311     Ssl::errorDetailInitialize();
 312 #endif
 313 }
 314
 315 void
 316 errorClean(void)
 317 {
 318     if (error_text) {
 319         int i;
 320
 321         for (i = ERR_NONE + 1; i < error_page_count; ++i)
 322             safe_free(error_text[i]);
 323
 324         safe_free(error_text);
 325     }
 326
 327     while (!ErrorDynamicPages.empty()) {
 328         delete ErrorDynamicPages.back();
 329         ErrorDynamicPages.pop_back();
 330     }
 331
 332     error_page_count = 0;
 333
 334 #if USE_OPENSSL
 335     Ssl::errorDetailClean();
 336 #endif
 337 }
 338
 339 /// \ingroup ErrorPageInternal
 340 static const char *
 341 errorFindHardText(err_type type)
 342 {
 343     for (const auto &m: HardCodedErrors) {
 344         if (m.type == type)
 345             return m.text;
 346     }
 347     return nullptr;
 348 }
 349
 350 TemplateFile::TemplateFile(const char *name, const err_type code): silent(false), wasLoaded(false), templateName(name), templateCode(code)
 351 {
 352     assert(name);
 353 }
 354
 355 void
 356 TemplateFile::loadDefault()
 357 {
 358     if (loaded()) // already loaded?
 359         return;
 360
 361     /** test error_directory configured location */
 362     if (Config.errorDirectory) {
 363         char path[MAXPATHLEN];
 364         snprintf(path, sizeof(path), "%s/%s", Config.errorDirectory, templateName.termedBuf());
 365         loadFromFile(path);
 366     }
 367
 368 #if USE_ERR_LOCALES
 369     /** test error_default_language location */
 370     if (!loaded() && Config.errorDefaultLanguage) {
 371         if (!tryLoadTemplate(Config.errorDefaultLanguage)) {
 372             debugs(1, (templateCode < TCP_RESET ? DBG_CRITICAL : 3), "ERROR: Unable to load default error language files. Reset to backups.");
 373         }
 374     }
 375 #endif
 376
 377     /* test default location if failed (templates == English translation base templates) */
 378     if (!loaded()) {
 379         tryLoadTemplate("templates");
 380     }
 381
 382     /* giving up if failed */
 383     if (!loaded()) {
 384         debugs(1, (templateCode < TCP_RESET ? DBG_CRITICAL : 3), "WARNING: failed to find or read error text file " << templateName);
 385         template_.clear();
 386         setDefault();
 387         wasLoaded = true;
 388     }
 389 }
 390
 391 bool
 392 TemplateFile::tryLoadTemplate(const char *lang)
 393 {
 394     assert(lang);
 395
 396     char path[MAXPATHLEN];
 397     /* TODO: prep the directory path string to prevent snprintf ... */
 398     snprintf(path, sizeof(path), "%s/%s/%s",
 399              DEFAULT_SQUID_ERROR_DIR, lang, templateName.termedBuf());
 400     path[MAXPATHLEN-1] = '\0';
 401
 402     if (loadFromFile(path))
 403         return true;
 404
 405 #if HAVE_GLOB
 406     if ( strlen(lang) == 2) {
 407         /* TODO glob the error directory for sub-dirs matching: <tag> '-*'   */
 408         /* use first result. */
 409         debugs(4,2, "wildcard fallback errors not coded yet.");
 410     }
 411 #endif
 412
 413     return false;
 414 }
 415
 416 bool
 417 TemplateFile::loadFromFile(const char *path)
 418 {
 419     int fd;
 420     char buf[4096];
 421     ssize_t len;
 422
 423     if (loaded()) // already loaded?
 424         return true;
 425
 426     fd = file_open(path, O_RDONLY | O_TEXT);
 427
 428     if (fd < 0) {
 429         /* with dynamic locale negotiation we may see some failures before a success. */
 430         if (!silent && templateCode < TCP_RESET) {
 431             int xerrno = errno;
 432             debugs(4, DBG_CRITICAL, "ERROR: loading file '" << path << "': " << xstrerr(xerrno));
 433         }
 434         wasLoaded = false;
 435         return wasLoaded;
 436     }
 437
 438     template_.clear();
 439     while ((len = FD_READ_METHOD(fd, buf, sizeof(buf))) > 0) {
 440         template_.append(buf, len);
 441     }
 442
 443     if (len < 0) {
 444         int xerrno = errno;
 445         file_close(fd);
 446         debugs(4, DBG_CRITICAL, MYNAME << "ERROR: failed to fully read: '" << path << "': " << xstrerr(xerrno));
 447         wasLoaded = false;
 448         return false;
 449     }
 450
 451     file_close(fd);
 452
 453     filename = SBuf(path);
 454
 455     if (!parse()) {
 456         debugs(4, DBG_CRITICAL, "ERROR: parsing error in template file: " << path);
 457         wasLoaded = false;
 458         return false;
 459     }
 460
 461     wasLoaded = true;
 462     return wasLoaded;
 463 }
 464
 465 bool strHdrAcptLangGetItem(const String &hdr, char *lang, int langLen, size_t &pos)
 466 {
 467     while (pos < hdr.size()) {
 468
 469         /* skip any initial whitespace. */
 470         while (pos < hdr.size() && xisspace(hdr[pos]))
 471             ++pos;
 472
 473         /*
 474          * Header value format:
 475          *  - sequence of whitespace delimited tags
 476          *  - each tag may suffix with ';'.* which we can ignore.
 477          *  - IFF a tag contains only two characters we can wildcard ANY translations matching: <it> '-'? .*
 478          *    with preference given to an exact match.
 479          */
 480         bool invalid_byte = false;
 481         char *dt = lang;
 482         while (pos < hdr.size() && hdr[pos] != ';' && hdr[pos] != ',' && !xisspace(hdr[pos]) && dt < (lang + (langLen -1)) ) {
 483             if (!invalid_byte) {
 484 #if USE_HTTP_VIOLATIONS
 485                 // if accepting violations we may as well accept some broken browsers
 486                 //  which may send us the right code, wrong ISO formatting.
 487                 if (hdr[pos] == '_')
 488                     *dt = '-';
 489                 else
 490 #endif
 491                     *dt = xtolower(hdr[pos]);
 492                 // valid codes only contain A-Z, hyphen (-) and *
 493                 if (*dt != '-' && *dt != '*' && (*dt < 'a' || *dt > 'z') )
 494                     invalid_byte = true;
 495                 else
 496                     ++dt; // move to next destination byte.
 497             }
 498             ++pos;
 499         }
 500         *dt = '\0'; // nul-terminated the filename content string before system use.
 501
 502         // if we terminated the tag on garbage or ';' we need to skip to the next ',' or end of header.
 503         while (pos < hdr.size() && hdr[pos] != ',')
 504             ++pos;
 505
 506         if (pos < hdr.size() && hdr[pos] == ',')
 507             ++pos;
 508
 509         debugs(4, 9, "STATE: lang=" << lang << ", pos=" << pos << ", buf='" << ((pos < hdr.size()) ? hdr.substr(pos,hdr.size()) : "") << "'");
 510
 511         /* if we found anything we might use, try it. */
 512         if (*lang != '\0' && !invalid_byte)
 513             return true;
 514     }
 515     return false;
 516 }
 517
 518 bool
 519 TemplateFile::loadFor(const HttpRequest *request)
 520 {
 521     String hdr;
 522
 523 #if USE_ERR_LOCALES
 524     if (loaded()) // already loaded?
 525         return true;
 526
 527     if (!request || !request->header.getList(Http::HdrType::ACCEPT_LANGUAGE, &hdr))
 528         return false;
 529
 530     char lang[256];
 531     size_t pos = 0; // current parsing position in header string
 532
 533     debugs(4, 6, "Testing Header: '" << hdr << "'");
 534
 535     while ( strHdrAcptLangGetItem(hdr, lang, 256, pos) ) {
 536
 537         /* wildcard uses the configured default language */
 538         if (lang[0] == '*' && lang[1] == '\0') {
 539             debugs(4, 6, "Found language '" << lang << "'. Using configured default.");
 540             return false;
 541         }
 542
 543         debugs(4, 6, "Found language '" << lang << "', testing for available template");
 544
 545         if (tryLoadTemplate(lang)) {
 546             /* store the language we found for the Content-Language reply header */
 547             errLanguage = lang;
 548             break;
 549         } else if (Config.errorLogMissingLanguages) {
 550             debugs(4, DBG_IMPORTANT, "WARNING: Error Pages Missing Language: " << lang);
 551         }
 552     }
 553 #else
 554     (void)request;
 555 #endif
 556
 557     return loaded();
 558 }
 559
 560 ErrorDynamicPageInfo::ErrorDynamicPageInfo(const int anId, const char *aName, const SBuf &aCfgLocation):
 561     id(anId),
 562     page_name(xstrdup(aName)),
 563     uri(nullptr),
 564     filename(nullptr),
 565     cfgLocation(aCfgLocation),
 566     page_redirect(static_cast<Http::StatusCode>(atoi(page_name)))
 567 {
 568     const char *filenameOrUri = nullptr;
 569     if (xisdigit(*page_name)) {
 570         if (const char *statusCodeEnd = strchr(page_name, ':'))
 571             filenameOrUri = statusCodeEnd + 1;
 572     } else {
 573         assert(!page_redirect);
 574         filenameOrUri = page_name;
 575     }
 576
 577     // Guessed uri, filename, or both values may be nil or malformed.
 578     // They are validated later.
 579     if (!page_redirect) {
 580         if (filenameOrUri && strchr(filenameOrUri, ':')) // looks like a URL
 581             uri = filenameOrUri;
 582         else
 583             filename = filenameOrUri;
 584     }
 585     else if (page_redirect/100 == 3) {
 586         // redirects imply a URL
 587         uri = filenameOrUri;
 588     } else {
 589         // non-redirects imply an error page name
 590         filename = filenameOrUri;
 591     }
 592
 593     const auto info = this; // source code change reduction hack
 594     // TODO: Move and refactor to avoid self_destruct()s in reconfigure.
 595
 596     /* WARNING on redirection status:
 597      * 2xx are permitted, but not documented officially.
 598      * - might be useful for serving static files (PAC etc) in special cases
 599      * 3xx require a URL suitable for Location: header.
 600      * - the current design does not allow for a Location: URI as well as a local file template
 601      *   although this possibility is explicitly permitted in the specs.
 602      * 4xx-5xx require a local file template.
 603      * - sending Location: on these codes with no body is invalid by the specs.
 604      * - current result is Squid crashing or XSS problems as dynamic deny_info load random disk files.
 605      * - a future redesign of the file loading may result in loading remote objects sent inline as local body.
 606      */
 607     if (info->page_redirect == Http::scNone)
 608         ; // special case okay.
 609     else if (info->page_redirect < 200 || info->page_redirect > 599) {
 610         // out of range
 611         debugs(0, DBG_CRITICAL, "FATAL: status " << info->page_redirect << " is not valid on '" << page_name << "'");
 612         self_destruct();
 613     } else if ( /* >= 200 && */ info->page_redirect < 300 && strchr(&(page_name[4]), ':')) {
 614         // 2xx require a local template file
 615         debugs(0, DBG_CRITICAL, "FATAL: status " << info->page_redirect << " requires a template on '" << page_name << "'");
 616         self_destruct();
 617     } else if (info->page_redirect >= 300 && info->page_redirect <= 399 && !strchr(&(page_name[4]), ':')) {
 618         // 3xx require an absolute URL
 619         debugs(0, DBG_CRITICAL, "FATAL: status " << info->page_redirect << " requires a URL on '" << page_name << "'");
 620         self_destruct();
 621     } else if (info->page_redirect >= 400 /* && <= 599 */ && strchr(&(page_name[4]), ':')) {
 622         // 4xx/5xx require a local template file
 623         debugs(0, DBG_CRITICAL, "FATAL: status " << info->page_redirect << " requires a template on '" << page_name << "'");
 624         self_destruct();
 625     }
 626     // else okay.
 627 }
 628
 629 /// \ingroup ErrorPageInternal
 630 static int
 631 errorPageId(const char *page_name)
 632 {
 633     for (int i = 0; i < ERR_MAX; ++i) {
 634         if (strcmp(err_type_str[i], page_name) == 0)
 635             return i;
 636     }
 637
 638     for (size_t j = 0; j < ErrorDynamicPages.size(); ++j) {
 639         if (strcmp(ErrorDynamicPages[j]->page_name, page_name) == 0)
 640             return j + ERR_MAX;
 641     }
 642
 643     return ERR_NONE;
 644 }
 645
 646 err_type
 647 errorReservePageId(const char *page_name, const SBuf &cfgLocation)
 648 {
 649     int id = errorPageId(page_name);
 650
 651     if (id == ERR_NONE) {
 652         id = ERR_MAX + ErrorDynamicPages.size();
 653         const auto info = new ErrorDynamicPageInfo(id, page_name, cfgLocation);
 654         ErrorDynamicPages.push_back(info);
 655     }
 656
 657     return (err_type)id;
 658 }
 659
 660 /// \ingroup ErrorPageInternal
 661 const char *
 662 errorPageName(int pageId)
 663 {
 664     if (pageId >= ERR_NONE && pageId < ERR_MAX)     /* common case */
 665         return err_type_str[pageId];
 666
 667     if (pageId >= ERR_MAX && pageId - ERR_MAX < (ssize_t)ErrorDynamicPages.size())
 668         return ErrorDynamicPages[pageId - ERR_MAX]->page_name;
 669
 670     return "ERR_UNKNOWN";   /* should not happen */
 671 }
 672
 673 ErrorState *
 674 ErrorState::NewForwarding(err_type type, HttpRequestPointer &request, const AccessLogEntry::Pointer &ale)
 675 {
 676     const Http::StatusCode status = (request && request->flags.needValidation) ?
 677                                     Http::scGatewayTimeout : Http::scServiceUnavailable;
 678     return new ErrorState(type, status, request.getRaw(), ale);
 679 }
 680
 681 ErrorState::ErrorState(err_type t) :
 682     type(t),
 683     page_id(t),
 684     callback(nullptr)
 685 {
 686 }
 687
 688 ErrorState::ErrorState(err_type t, Http::StatusCode status, HttpRequest * req, const AccessLogEntry::Pointer &anAle) :
 689     ErrorState(t)
 690 {
 691     if (page_id >= ERR_MAX && ErrorDynamicPages[page_id - ERR_MAX]->page_redirect != Http::scNone)
 692         httpStatus = ErrorDynamicPages[page_id - ERR_MAX]->page_redirect;
 693     else
 694         httpStatus = status;
 695
 696     if (req) {
 697         request = req;
 698         src_addr = req->client_addr;
 699     }
 700
 701     ale = anAle;
 702 }
 703
 704 ErrorState::ErrorState(HttpRequest * req, HttpReply *errorReply) :
 705     ErrorState(ERR_RELAY_REMOTE)
 706 {
 707     Must(errorReply);
 708     response_ = errorReply;
 709     httpStatus = errorReply->sline.status();
 710
 711     if (req) {
 712         request = req;
 713         src_addr = req->client_addr;
 714     }
 715 }
 716
 717 void
 718 errorAppendEntry(StoreEntry * entry, ErrorState * err)
 719 {
 720     assert(entry->mem_obj != nullptr);
 721     assert (entry->isEmpty());
 722     debugs(4, 4, "storing " << err << " in " << *entry);
 723
 724     if (entry->store_status != STORE_PENDING) {
 725         debugs(4, 2, "Skipping error page due to store_status: " << entry->store_status);
 726         /*
 727          * If the entry is not STORE_PENDING, then no clients
 728          * care about it, and we don't need to generate an
 729          * error message
 730          */
 731         assert(EBIT_TEST(entry->flags, ENTRY_ABORTED));
 732         assert(entry->mem_obj->nclients == 0);
 733         delete err;
 734         return;
 735     }
 736
 737     if (err->page_id == TCP_RESET) {
 738         if (err->request) {
 739             debugs(4, 2, "RSTing this reply");
 740             err->request->flags.resetTcp = true;
 741         }
 742     }
 743
 744     entry->storeErrorResponse(err->BuildHttpReply());
 745     delete err;
 746 }
 747
 748 void
 749 errorSend(const Comm::ConnectionPointer &conn, ErrorState * err)
 750 {
 751     debugs(4, 3, conn << ", err=" << err);
 752     assert(Comm::IsConnOpen(conn));
 753
 754     HttpReplyPointer rep(err->BuildHttpReply());
 755
 756     MemBuf *mb = rep->pack();
 757     AsyncCall::Pointer call = commCbCall(78, 5, "errorSendComplete",
 758                                          CommIoCbPtrFun(&errorSendComplete, err));
 759     Comm::Write(conn, mb, call);
 760     delete mb;
 761 }
 762
 763 /**
 764  \ingroup ErrorPageAPI
 765  *
 766  * Called by commHandleWrite() after data has been written
 767  * to the client socket.
 768  *
 769  \note If there is a callback, the callback is responsible for
 770  *     closing the FD, otherwise we do it ourselves.
 771  */
 772 static void
 773 errorSendComplete(const Comm::ConnectionPointer &conn, char *, size_t size, Comm::Flag errflag, int, void *data)
 774 {
 775     ErrorState *err = static_cast<ErrorState *>(data);
 776     debugs(4, 3, conn << ", size=" << size);
 777
 778     if (errflag != Comm::ERR_CLOSING) {
 779         if (err->callback) {
 780             debugs(4, 3, "errorSendComplete: callback");
 781             err->callback(conn->fd, err->callback_data, size);
 782         } else {
 783             debugs(4, 3, "errorSendComplete: comm_close");
 784             conn->close();
 785         }
 786     }
 787
 788     delete err;
 789 }
 790
 791 ErrorState::~ErrorState()
 792 {
 793     safe_free(redirect_url);
 794     safe_free(url);
 795     safe_free(request_hdrs);
 796     wordlistDestroy(&ftp.server_msg);
 797     safe_free(ftp.request);
 798     safe_free(ftp.reply);
 799     safe_free(err_msg);
 800 #if USE_ERR_LOCALES
 801     if (err_language != Config.errorDefaultLanguage)
 802 #endif
 803         safe_free(err_language);
 804 }
 805
 806 int
 807 ErrorState::Dump(MemBuf * mb)
 808 {
 809     MemBuf str;
 810     char ntoabuf[MAX_IPSTRLEN];
 811
 812     str.reset();
 813     /* email subject line */
 814     str.appendf("CacheErrorInfo - %s", errorPageName(type));
 815     mb->appendf("?subject=%s", rfc1738_escape_part(str.buf));
 816     str.reset();
 817     /* email body */
 818     str.appendf("CacheHost: %s\r\n", getMyHostname());
 819     /* - Err Msgs */
 820     str.appendf("ErrPage: %s\r\n", errorPageName(type));
 821
 822     if (xerrno) {
 823         str.appendf("Err: (%d) %s\r\n", xerrno, strerror(xerrno));
 824     } else {
 825         str.append("Err: [none]\r\n", 13);
 826     }
 827 #if USE_AUTH
 828     if (auth_user_request.getRaw() && auth_user_request->denyMessage())
 829         str.appendf("Auth ErrMsg: %s\r\n", auth_user_request->denyMessage());
 830 #endif
 831     if (dnsError.size() > 0)
 832         str.appendf("DNS ErrMsg: %s\r\n", dnsError.termedBuf());
 833
 834     /* - TimeStamp */
 835     str.appendf("TimeStamp: %s\r\n\r\n", Time::FormatRfc1123(squid_curtime));
 836
 837     /* - IP stuff */
 838     str.appendf("ClientIP: %s\r\n", src_addr.toStr(ntoabuf,MAX_IPSTRLEN));
 839
 840     if (request && request->hier.host[0] != '\0') {
 841         str.appendf("ServerIP: %s\r\n", request->hier.host);
 842     }
 843
 844     str.append("\r\n", 2);
 845     /* - HTTP stuff */
 846     str.append("HTTP Request:\r\n", 15);
 847     if (request) {
 848         str.appendf(SQUIDSBUFPH " " SQUIDSBUFPH " %s/%d.%d\n",
 849                     SQUIDSBUFPRINT(request->method.image()),
 850                     SQUIDSBUFPRINT(request->url.path()),
 851                     AnyP::ProtocolType_str[request->http_ver.protocol],
 852                     request->http_ver.major, request->http_ver.minor);
 853         request->header.packInto(&str);
 854     }
 855
 856     str.append("\r\n", 2);
 857     /* - FTP stuff */
 858
 859     if (ftp.request) {
 860         str.appendf("FTP Request: %s\r\n", ftp.request);
 861         str.appendf("FTP Reply: %s\r\n", (ftp.reply? ftp.reply:"[none]"));
 862         str.append("FTP Msg: ", 9);
 863         wordlistCat(ftp.server_msg, &str);
 864         str.append("\r\n", 2);
 865     }
 866
 867     str.append("\r\n", 2);
 868     mb->appendf("&body=%s", rfc1738_escape_part(str.buf));
 869     str.clean();
 870     return 0;
 871 }
 872
 873 /// \ingroup ErrorPageInternal
 874 #define CVT_BUF_SZ 512
 875
 876 void
 877 ErrorState::compileLogformatCode(Build &build)
 878 {
 879     assert(LogformatMagic.cmp(build.input, LogformatMagic.length()) == 0);
 880
 881     try {
 882         const auto logformat = build.input + LogformatMagic.length();
 883
 884         // Logformat supports undocumented "external" encoding specifications
 885         // like [%>h] or "%<a". To preserve the possibility of extending
 886         // @Squid{} syntax to non-logformat sequences, we require logformat
 887         // sequences to start with '%'. This restriction does not limit
 888         // logformat quoting abilities. TODO: Deprecate "external" encoding?
 889         if (*logformat != '%')
 890             throw TexcHere("logformat expressions that do not start with % are not supported");
 891
 892         static MemBuf result;
 893         result.reset();
 894         const auto logformatLen = Format::AssembleOne(logformat, result, ale);
 895         assert(logformatLen > 0);
 896         const auto closure = logformat + logformatLen;
 897         if (*closure != '}')
 898             throw TexcHere("Missing closing brace (})");
 899         build.output.append(result.content(), result.contentSize());
 900         build.input = closure + 1;
 901         return;
 902     } catch (...) {
 903         noteBuildError("Bad @Squid{logformat} sequence", build.input);
 904     }
 905
 906     // we cannot recover reliably so stop interpreting the rest of input
 907     const auto remainingSize = strlen(build.input);
 908     build.output.append(build.input, remainingSize);
 909     build.input += remainingSize;
 910 }
 911
 912 void
 913 ErrorState::compileLegacyCode(Build &build)
 914 {
 915     static MemBuf mb;
 916     const char *p = nullptr;   /* takes priority over mb if set */
 917     int do_quote = 1;
 918     int no_urlescape = 0;       /* if true then item is NOT to be further URL-encoded */
 919     char ntoabuf[MAX_IPSTRLEN];
 920
 921     mb.reset();
 922
 923     const auto &building_deny_info_url = build.building_deny_info_url; // a change reduction hack
 924
 925     const auto letter = build.input[1];
 926
 927     switch (letter) {
 928
 929     case 'a':
 930 #if USE_AUTH
 931         if (request && request->auth_user_request)
 932             p = request->auth_user_request->username();
 933         if (!p)
 934 #endif
 935             p = "-";
 936         break;
 937
 938     case 'A':
 939         // TODO: When/if we get ALE here, pass it as well
 940         if (const auto addr = FindListeningPortAddress(request.getRaw(), nullptr))
 941             mb.appendf("%s", addr->toStr(ntoabuf, MAX_IPSTRLEN));
 942         else
 943             p = "-";
 944         break;
 945
 946     case 'b':
 947         mb.appendf("%u", getMyPort());
 948         break;
 949
 950     case 'B':
 951         if (building_deny_info_url) break;
 952         if (request) {
 953             const SBuf &tmp = Ftp::UrlWith2f(request.getRaw());
 954             mb.append(tmp.rawContent(), tmp.length());
 955         } else
 956             p = "[no URL]";
 957         break;
 958
 959     case 'c':
 960         if (building_deny_info_url) break;
 961         p = errorPageName(type);
 962         break;
 963
 964     case 'D':
 965         if (!build.allowRecursion)
 966             p = "%D";  // if recursion is not allowed, do not convert
 967         else if (detail) {
 968             auto rawDetail = detail->verbose(request);
 969             // XXX: Performance regression. c_str() reallocates
 970             const auto compiledDetail = compileBody(rawDetail.c_str(), false);
 971             mb.append(compiledDetail.rawContent(), compiledDetail.length());
 972             do_quote = 0;
 973         }
 974         if (!mb.contentSize())
 975             mb.append("[No Error Detail]", 17);
 976         break;
 977
 978     case 'e':
 979         mb.appendf("%d", xerrno);
 980         break;
 981
 982     case 'E':
 983         if (xerrno)
 984             mb.appendf("(%d) %s", xerrno, strerror(xerrno));
 985         else
 986             mb.append("[No Error]", 10);
 987         break;
 988
 989     case 'f':
 990         if (building_deny_info_url) break;
 991         /* FTP REQUEST LINE */
 992         if (ftp.request)
 993             p = ftp.request;
 994         else
 995             p = "nothing";
 996         break;
 997
 998     case 'F':
 999         if (building_deny_info_url) break;
1000         /* FTP REPLY LINE */
1001         if (ftp.reply)
1002             p = ftp.reply;
1003         else
1004             p = "nothing";
1005         break;
1006
1007     case 'g':
1008         if (building_deny_info_url) break;
1009         /* FTP SERVER RESPONSE */
1010         if (ftp.listing) {
1011             mb.append(ftp.listing->content(), ftp.listing->contentSize());
1012             do_quote = 0;
1013         } else if (ftp.server_msg) {
1014             wordlistCat(ftp.server_msg, &mb);
1015         }
1016         break;
1017
1018     case 'h':
1019         mb.appendf("%s", getMyHostname());
1020         break;
1021
1022     case 'H':
1023         if (request) {
1024             if (request->hier.host[0] != '\0') // if non-empty string.
1025                 p = request->hier.host;
1026             else
1027                 p = request->url.host();
1028         } else if (!building_deny_info_url)
1029             p = "[unknown host]";
1030         break;
1031
1032     case 'i':
1033         mb.appendf("%s", src_addr.toStr(ntoabuf,MAX_IPSTRLEN));
1034         break;
1035
1036     case 'I':
1037         if (request && request->hier.tcpServer)
1038             p = request->hier.tcpServer->remote.toStr(ntoabuf,MAX_IPSTRLEN);
1039         else if (!building_deny_info_url)
1040             p = "[unknown]";
1041         break;
1042
1043     case 'l':
1044         if (building_deny_info_url) break;
1045         mb.append(error_stylesheet.content(), error_stylesheet.contentSize());
1046         do_quote = 0;
1047         break;
1048
1049     case 'L':
1050         if (building_deny_info_url) break;
1051         if (Config.errHtmlText) {
1052             mb.appendf("%s", Config.errHtmlText);
1053             do_quote = 0;
1054         } else
1055             p = "[not available]";
1056         break;
1057
1058     case 'm':
1059         if (building_deny_info_url) break;
1060 #if USE_AUTH
1061         if (auth_user_request.getRaw())
1062             p = auth_user_request->denyMessage("[not available]");
1063         else
1064             p = "[not available]";
1065 #else
1066         p = "-";
1067 #endif
1068         break;
1069
1070     case 'M':
1071         if (request) {
1072             const SBuf &m = request->method.image();
1073             mb.append(m.rawContent(), m.length());
1074         } else if (!building_deny_info_url)
1075             p = "[unknown method]";
1076         break;
1077
1078     case 'O':
1079         if (!building_deny_info_url)
1080             do_quote = 0;
1081         [[fallthrough]];
1082     case 'o':
1083         p = request ? request->extacl_message.termedBuf() : external_acl_message;
1084         if (!p && !building_deny_info_url)
1085             p = "[not available]";
1086         break;
1087
1088     case 'p':
1089         if (request) {
1090             mb.appendf("%u", request->url.port());
1091         } else if (!building_deny_info_url) {
1092             p = "[unknown port]";
1093         }
1094         break;
1095
1096     case 'P':
1097         if (request) {
1098             const SBuf &m = request->url.getScheme().image();
1099             mb.append(m.rawContent(), m.length());
1100         } else if (!building_deny_info_url) {
1101             p = "[unknown protocol]";
1102         }
1103         break;
1104
1105     case 'R':
1106         if (building_deny_info_url) {
1107             if (request != nullptr) {
1108                 const SBuf &tmp = request->url.path();
1109                 mb.append(tmp.rawContent(), tmp.length());
1110                 no_urlescape = 1;
1111             } else
1112                 p = "[no request]";
1113             break;
1114         }
1115         if (request) {
1116             mb.appendf(SQUIDSBUFPH " " SQUIDSBUFPH " %s/%d.%d\n",
1117                        SQUIDSBUFPRINT(request->method.image()),
1118                        SQUIDSBUFPRINT(request->url.path()),
1119                        AnyP::ProtocolType_str[request->http_ver.protocol],
1120                        request->http_ver.major, request->http_ver.minor);
1121             request->header.packInto(&mb, true); //hide authorization data
1122         } else if (request_hdrs) {
1123             p = request_hdrs;
1124         } else {
1125             p = "[no request]";
1126         }
1127         break;
1128
1129     case 's':
1130         /* for backward compat we make %s show the full URL. Drop this in some future release. */
1131         if (building_deny_info_url) {
1132             if (request) {
1133                 const SBuf &tmp = request->effectiveRequestUri();
1134                 mb.append(tmp.rawContent(), tmp.length());
1135             } else
1136                 p = url;
1137             debugs(0, DBG_CRITICAL, "WARNING: deny_info now accepts coded tags. Use %u to get the full URL instead of %s");
1138         } else
1139             p = visible_appname_string;
1140         break;
1141
1142     case 'S':
1143         if (building_deny_info_url) {
1144             p = visible_appname_string;
1145             break;
1146         }
1147         /* signature may contain %-escapes, recursion */
1148         if (page_id != ERR_SQUID_SIGNATURE) {
1149             const int saved_id = page_id;
1150             page_id = ERR_SQUID_SIGNATURE;
1151             const auto signature = buildBody();
1152             mb.append(signature.rawContent(), signature.length());
1153             page_id = saved_id;
1154             do_quote = 0;
1155         } else {
1156             /* wow, somebody put %S into ERR_SIGNATURE, stop recursion */
1157             p = "[%S]";
1158         }
1159         break;
1160
1161     case 't':
1162         mb.appendf("%s", Time::FormatHttpd(squid_curtime));
1163         break;
1164
1165     case 'T':
1166         mb.appendf("%s", Time::FormatRfc1123(squid_curtime));
1167         break;
1168
1169     case 'U':
1170         /* Using the fake-https version of absolute-URI so error pages see https:// */
1171         /* even when the url-path cannot be shown as more than '*' */
1172         if (request)
1173             p = urlCanonicalFakeHttps(request.getRaw());
1174         else if (url)
1175             p = url;
1176         else if (!building_deny_info_url)
1177             p = "[no URL]";
1178         break;
1179
1180     case 'u':
1181         if (request) {
1182             const SBuf &tmp = request->effectiveRequestUri();
1183             mb.append(tmp.rawContent(), tmp.length());
1184         } else if (url)
1185             p = url;
1186         else if (!building_deny_info_url)
1187             p = "[no URL]";
1188         break;
1189
1190     case 'w':
1191         if (Config.adminEmail)
1192             mb.appendf("%s", Config.adminEmail);
1193         else if (!building_deny_info_url)
1194             p = "[unknown]";
1195         break;
1196
1197     case 'W':
1198         if (building_deny_info_url) break;
1199         if (Config.adminEmail && Config.onoff.emailErrData)
1200             Dump(&mb);
1201         no_urlescape = 1;
1202         break;
1203
1204     case 'x':
1205         if (detail) {
1206             const auto brief = detail->brief();
1207             mb.append(brief.rawContent(), brief.length());
1208         } else if (!building_deny_info_url) {
1209             p = "[Unknown Error Code]";
1210         }
1211         break;
1212
1213     case 'z':
1214         if (building_deny_info_url) break;
1215         if (dnsError.size() > 0)
1216             p = dnsError.termedBuf();
1217         else if (ftp.cwd_msg)
1218             p = ftp.cwd_msg;
1219         else
1220             p = "[unknown]";
1221         break;
1222
1223     case 'Z':
1224         if (building_deny_info_url) break;
1225         if (err_msg)
1226             p = err_msg;
1227         else
1228             p = "[unknown]";
1229         break;
1230
1231     case '%':
1232         p = "%";
1233         break;
1234
1235     default:
1236         if (building_deny_info_url)
1237             bypassBuildErrorXXX("Unsupported deny_info %code", build.input);
1238         else if (letter != ';')
1239             bypassBuildErrorXXX("Unsupported error page %code", build.input);
1240         // else too many "font-size: 100%;" template errors to report
1241
1242         mb.append(build.input, 2);
1243         do_quote = 0;
1244         break;
1245     }
1246
1247     if (!p)
1248         p = mb.buf;     /* do not use mb after this assignment! */
1249
1250     assert(p);
1251
1252     debugs(4, 3, "%" << letter << " --> '" << p << "'" );
1253
1254     if (do_quote)
1255         p = html_quote(p);
1256
1257     if (building_deny_info_url && !no_urlescape)
1258         p = rfc1738_escape_part(p);
1259
1260     // TODO: Optimize by replacing mb with direct build.output usage.
1261     build.output.append(p, strlen(p));
1262     build.input += 2;
1263 }
1264
1265 void
1266 ErrorState::validate()
1267 {
1268     if (const auto urlTemplate = ErrorPage::IsDenyInfoUri(page_id)) {
1269         (void)compile(urlTemplate, true, true);
1270     } else {
1271         assert(page_id > ERR_NONE);
1272         assert(page_id < error_page_count);
1273         (void)compileBody(error_text[page_id], true);
1274     }
1275 }
1276
1277 HttpReply *
1278 ErrorState::BuildHttpReply()
1279 {
1280     if (response_)
1281         return response_.getRaw();
1282
1283     HttpReply *rep = new HttpReply;
1284     const char *name = errorPageName(page_id);
1285     /* no LMT for error pages; error pages expire immediately */
1286
1287     if (const auto urlTemplate = ErrorPage::IsDenyInfoUri(page_id)) {
1288         /* Redirection */
1289         Http::StatusCode status = Http::scFound;
1290         // Use configured 3xx reply status if set.
1291         if (name[0] == '3')
1292             status = httpStatus;
1293         else {
1294             // Use 307 for HTTP/1.1 non-GET/HEAD requests.
1295             if (request && request->method != Http::METHOD_GET && request->method != Http::METHOD_HEAD && request->http_ver >= Http::ProtocolVersion(1,1))
1296                 status = Http::scTemporaryRedirect;
1297         }
1298
1299         rep->setHeaders(status, nullptr, "text/html;charset=utf-8", 0, 0, -1);
1300
1301         if (request) {
1302             auto location = compile(urlTemplate, true, true);
1303             rep->header.putStr(Http::HdrType::LOCATION, location.c_str());
1304         }
1305
1306         httpHeaderPutStrf(&rep->header, Http::HdrType::X_SQUID_ERROR, "%d %s", httpStatus, "Access Denied");
1307     } else {
1308         const auto body = buildBody();
1309         rep->setHeaders(httpStatus, nullptr, "text/html;charset=utf-8", body.length(), 0, -1);
1310         /*
1311          * include some information for downstream caches. Implicit
1312          * replaceable content. This isn't quite sufficient. xerrno is not
1313          * necessarily meaningful to another system, so we really should
1314          * expand it. Additionally, we should identify ourselves. Someone
1315          * might want to know. Someone _will_ want to know OTOH, the first
1316          * X-CACHE-MISS entry should tell us who.
1317          */
1318         httpHeaderPutStrf(&rep->header, Http::HdrType::X_SQUID_ERROR, "%s %d", name, xerrno);
1319
1320 #if USE_ERR_LOCALES
1321         /*
1322          * If error page auto-negotiate is enabled in any way, send the Vary.
1323          * RFC 2616 section 13.6 and 14.44 says MAY and SHOULD do this.
1324          * We have even better reasons though:
1325          * see http://wiki.squid-cache.org/KnowledgeBase/VaryNotCaching
1326          */
1327         if (!Config.errorDirectory) {
1328             /* We 'negotiated' this ONLY from the Accept-Language. */
1329             static const SBuf acceptLanguage("Accept-Language");
1330             rep->header.updateOrAddStr(Http::HdrType::VARY, acceptLanguage);
1331         }
1332
1333         /* add the Content-Language header according to RFC section 14.12 */
1334         if (err_language) {
1335             rep->header.putStr(Http::HdrType::CONTENT_LANGUAGE, err_language);
1336         } else
1337 #endif /* USE_ERROR_LOCALES */
1338         {
1339             /* default templates are in English */
1340             /* language is known unless error_directory override used */
1341             if (!Config.errorDirectory)
1342                 rep->header.putStr(Http::HdrType::CONTENT_LANGUAGE, "en");
1343         }
1344
1345         rep->body.set(body);
1346     }
1347
1348     // Make sure error codes get back to the client side for logging and
1349     // error tracking.
1350     if (request) {
1351         if (detail)
1352             request->detailError(type, detail);
1353         else
1354             request->detailError(type, SysErrorDetail::NewIfAny(xerrno));
1355     }
1356
1357     return rep;
1358 }
1359
1360 SBuf
1361 ErrorState::buildBody()
1362 {
1363     assert(page_id > ERR_NONE && page_id < error_page_count);
1364
1365 #if USE_ERR_LOCALES
1366     /** error_directory option in squid.conf overrides translations.
1367      * Custom errors are always found either in error_directory or the templates directory.
1368      * Otherwise locate the Accept-Language header
1369      */
1370     if (!Config.errorDirectory && page_id < ERR_MAX) {
1371         if (err_language && err_language != Config.errorDefaultLanguage)
1372             safe_free(err_language);
1373
1374         ErrorPageFile localeTmpl(err_type_str[page_id], static_cast<err_type>(page_id));
1375         if (localeTmpl.loadFor(request.getRaw())) {
1376             inputLocation = localeTmpl.filename;
1377             assert(localeTmpl.language());
1378             err_language = xstrdup(localeTmpl.language());
1379             return compileBody(localeTmpl.text(), true);
1380         }
1381     }
1382 #endif /* USE_ERR_LOCALES */
1383
1384     /** \par
1385      * If client-specific error templates are not enabled or available.
1386      * fall back to the old style squid.conf settings.
1387      */
1388 #if USE_ERR_LOCALES
1389     if (!Config.errorDirectory)
1390         err_language = Config.errorDefaultLanguage;
1391 #endif
1392     debugs(4, 2, "No existing error page language negotiated for " << this << ". Using default error file.");
1393     return compileBody(error_text[page_id], true);
1394 }
1395
1396 SBuf
1397 ErrorState::compileBody(const char *input, bool allowRecursion)
1398 {
1399     return compile(input, false, allowRecursion);
1400 }
1401
1402 SBuf
1403 ErrorState::compile(const char *input, bool building_deny_info_url, bool allowRecursion)
1404 {
1405     assert(input);
1406
1407     Build build;
1408     build.building_deny_info_url = building_deny_info_url;
1409     build.allowRecursion = allowRecursion;
1410     build.input = input;
1411
1412     auto blockStart = build.input;
1413     while (const auto letter = *build.input) {
1414         if (letter == '%') {
1415             build.output.append(blockStart, build.input - blockStart);
1416             compileLegacyCode(build);
1417             blockStart = build.input;
1418         }
1419         else if (letter == '@' && LogformatMagic.cmp(build.input, LogformatMagic.length()) == 0) {
1420             build.output.append(blockStart, build.input - blockStart);
1421             compileLogformatCode(build);
1422             blockStart = build.input;
1423         } else {
1424             ++build.input;
1425         }
1426     }
1427     build.output.append(blockStart, build.input - blockStart);
1428     return build.output;
1429 }
1430
1431 /// react to a compile() error
1432 /// \param msg  description of what went wrong
1433 /// \param near  approximate start of the problematic input
1434 /// \param  forceBypass whether detection of this error was introduced late,
1435 /// after old configurations containing this error could have been
1436 /// successfully validated and deployed (i.e. the admin may not be
1437 /// able to fix this newly detected but old problem quickly)
1438 void
1439 ErrorState::noteBuildError_(const char *msg, const char *near, const bool forceBypass)
1440 {
1441     using ErrorPage::BuildErrorPrinter;
1442     const auto runtime = !starting_up;
1443     if (runtime || forceBypass) {
1444         // swallow this problem because the admin may not be (and/or the page
1445         // building code is not) ready to handle throwing consequences
1446
1447         static unsigned int seenErrors = 0;
1448         ++seenErrors;
1449
1450         const auto debugLevel =
1451             (seenErrors > 100) ? DBG_DATA:
1452             (starting_up || reconfiguring) ? DBG_CRITICAL:
1453             3; // most other errors have been reported as configuration errors
1454
1455         // Error fatality depends on the error context: Reconfiguration errors
1456         // are, like startup ones, DBG_CRITICAL but will never become FATAL.
1457         if (starting_up && seenErrors <= 10)
1458             debugs(4, debugLevel, "WARNING: The following configuration error will be fatal in future Squid versions");
1459
1460         debugs(4, debugLevel, "ERROR: " << BuildErrorPrinter(inputLocation, page_id, msg, near));
1461     } else {
1462         throw TexcHere(ToSBuf(BuildErrorPrinter(inputLocation, page_id, msg, near)));
1463     }
1464 }
1465
1466 /* ErrorPage::BuildErrorPrinter */
1467
1468 std::ostream &
1469 ErrorPage::BuildErrorPrinter::printLocation(std::ostream &os) const {
1470     if (!inputLocation.isEmpty())
1471         return os << inputLocation;
1472
1473     if (page_id < ERR_NONE || page_id >= error_page_count)
1474         return os << "[error page " << page_id << "]"; // should not happen
1475
1476     if (page_id < ERR_MAX)
1477         return os << err_type_str[page_id];
1478
1479     return os << "deny_info " << ErrorDynamicPages.at(page_id - ERR_MAX)->page_name;
1480 }
1481
1482 std::ostream &
1483 ErrorPage::BuildErrorPrinter::print(std::ostream &os) const {
1484     printLocation(os) << ": " << msg << " near ";
1485
1486     // TODO: Add support for prefix printing to Raw
1487     const size_t maxContextLength = 15; // plus "..."
1488     if (strlen(near) > maxContextLength) {
1489         os.write(near, maxContextLength);
1490         os << "...";
1491     } else {
1492         os << near;
1493     }
1494
1495     // XXX: We should not be converting (inner) exception to text if we are
1496     // going to throw again. See "add arbitrary (re)thrower-supplied details"
1497     // TODO in TextException.h for a long-term in-catcher solution.
1498     if (std::current_exception())
1499         os << "\n    additional info: " << CurrentException;
1500
1501     return os;
1502 }
1503
1504 /// add error page template to the global index
1505 static void
1506 ErrorPage::ImportStaticErrorText(const int page_id, const char *text, const SBuf &inputLocation)
1507 {
1508     assert(!error_text[page_id]);
1509     error_text[page_id] = xstrdup(text);
1510     ValidateStaticError(page_id, inputLocation);
1511 }
1512
1513 /// validate static error page
1514 static void
1515 ErrorPage::ValidateStaticError(const int page_id, const SBuf &inputLocation)
1516 {
1517     // Supplying nil ALE pointer limits validation to logformat %code
1518     // recognition by Format::Token::parse(). This is probably desirable
1519     // because actual %code assembly is slow and should not affect validation
1520     // when our ALE cannot have any real data (this code is not associated
1521     // with any real transaction).
1522     ErrorState anErr(err_type(page_id), Http::scNone, nullptr, nullptr);
1523     anErr.inputLocation = inputLocation;
1524     anErr.validate();
1525 }
1526
1527 std::ostream &
1528 operator <<(std::ostream &os, const ErrorState *err)
1529 {
1530     if (err)
1531         os << errorPageName(err->page_id);
1532     else
1533         os << "[none]";
1534     return os;
1535 }
1536