src/errorpage.cc

   1 /*
   2  * Copyright (C) 1996-2021 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 "SquidTime.h"
  33 #include "Store.h"
  34 #include "tools.h"
  35 #include "wordlist.h"
  36 #if USE_AUTH
  37 #include "auth/UserRequest.h"
  38 #endif
  39 #if USE_OPENSSL
  40 #include "ssl/ErrorDetailManager.h"
  41 #endif
  42
  43 /**
  44  \defgroup ErrorPageInternal Error Page Internals
  45  \ingroup ErrorPageAPI
  46  *
  47  \section ErrorPagesAbstract Abstract:
  48  *   These routines are used to generate error messages to be
  49  *   sent to clients.  The error type is used to select between
  50  *   the various message formats. (formats are stored in the
  51  *   Config.errorDirectory)
  52  */
  53
  54 #if !defined(DEFAULT_SQUID_ERROR_DIR)
  55 /** Where to look for errors if config path fails.
  56  \note Please use ./configure --datadir=/path instead of patching
  57  */
  58 #define DEFAULT_SQUID_ERROR_DIR   DEFAULT_SQUID_DATA_DIR"/errors"
  59 #endif
  60
  61 /// \ingroup ErrorPageInternal
  62 CBDATA_CLASS_INIT(ErrorState);
  63
  64 const SBuf ErrorState::LogformatMagic("@Squid{");
  65
  66 /* local types */
  67
  68 /// an error page created from admin-configurable metadata (e.g. deny_info)
  69 class ErrorDynamicPageInfo {
  70 public:
  71     ErrorDynamicPageInfo(const int anId, const char *aName, const SBuf &aCfgLocation);
  72     ~ErrorDynamicPageInfo() { xfree(page_name); }
  73
  74     /// error_text[] index for response body (unused in redirection responses)
  75     int id;
  76
  77     /// Primary deny_info parameter:
  78     /// * May start with an HTTP status code.
  79     /// * Either a well-known error page name, a filename, or a redirect URL.
  80     char *page_name;
  81
  82     /// admin-configured HTTP Location header value for redirection responses
  83     const char *uri;
  84
  85     /// admin-configured name for the error page template (custom or standard)
  86     const char *filename;
  87
  88     /// deny_info directive position in squid.conf (for reporting)
  89     SBuf cfgLocation;
  90
  91     // XXX: Misnamed. Not just for redirects.
  92     /// admin-configured HTTP status code
  93     Http::StatusCode page_redirect;
  94
  95 private:
  96     // no copying of any kind
  97     ErrorDynamicPageInfo(ErrorDynamicPageInfo &&) = delete;
  98 };
  99
 100 namespace ErrorPage {
 101
 102 /// state and parameters shared by several ErrorState::compile*() methods
 103 class Build
 104 {
 105 public:
 106     SBuf output; ///< compilation result
 107     const char *input = nullptr; ///< template bytes that need to be compiled
 108     bool building_deny_info_url = false; ///< whether we compile deny_info URI
 109     bool allowRecursion = false; ///< whether top-level compile() calls are OK
 110 };
 111
 112 /// pretty-prints error page/deny_info building error
 113 class BuildErrorPrinter
 114 {
 115 public:
 116     BuildErrorPrinter(const SBuf &anInputLocation, int aPage, const char *aMsg, const char *aNear): inputLocation(anInputLocation), page_id(aPage), msg(aMsg), near(aNear) {}
 117
 118     /// reports error details (for admin-visible exceptions and debugging)
 119     std::ostream &print(std::ostream &) const;
 120
 121     /// print() helper to report where the error was found
 122     std::ostream &printLocation(std::ostream &os) const;
 123
 124     /* saved constructor parameters */
 125     const SBuf &inputLocation;
 126     const int page_id;
 127     const char *msg;
 128     const char *near;
 129 };
 130
 131 static inline std::ostream &
 132 operator <<(std::ostream &os, const BuildErrorPrinter &context)
 133 {
 134     return context.print(os);
 135 }
 136
 137 static const char *IsDenyInfoUri(const int page_id);
 138
 139 static void ImportStaticErrorText(const int page_id, const char *text, const SBuf &inputLocation);
 140 static void ValidateStaticError(const int page_id, const SBuf &inputLocation);
 141
 142 } // namespace ErrorPage
 143
 144 /* local constant and vars */
 145
 146 /**
 147  \ingroup ErrorPageInternal
 148  *
 149  \note  hard coded error messages are not appended with %S
 150  *      automagically to give you more control on the format
 151  */
 152 static const struct {
 153     int type;           /* and page_id */
 154     const char *text;
 155 }
 156
 157 error_hard_text[] = {
 158
 159     {
 160         ERR_SQUID_SIGNATURE,
 161         "\n<br>\n"
 162         "<hr>\n"
 163         "<div id=\"footer\">\n"
 164         "Generated %T by %h (%s)\n"
 165         "</div>\n"
 166         "</body></html>\n"
 167     },
 168     {
 169         TCP_RESET,
 170         "reset"
 171     },
 172     {
 173         ERR_CLIENT_GONE,
 174         "unexpected client disconnect"
 175     },
 176     {
 177         ERR_SECURE_ACCEPT_FAIL,
 178         "secure accept fail"
 179     },
 180     {
 181         ERR_REQUEST_START_TIMEOUT,
 182         "request start timedout"
 183     },
 184     {
 185         MGR_INDEX,
 186         "mgr_index"
 187     }
 188 };
 189
 190 /// \ingroup ErrorPageInternal
 191 static std::vector<ErrorDynamicPageInfo *> ErrorDynamicPages;
 192
 193 /* local prototypes */
 194
 195 /// \ingroup ErrorPageInternal
 196 static const int error_hard_text_count = sizeof(error_hard_text) / sizeof(*error_hard_text);
 197
 198 /// \ingroup ErrorPageInternal
 199 static char **error_text = NULL;
 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     virtual 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     int i;
 344
 345     for (i = 0; i < error_hard_text_count; ++i)
 346         if (error_hard_text[i].type == type)
 347             return error_hard_text[i].text;
 348
 349     return NULL;
 350 }
 351
 352 TemplateFile::TemplateFile(const char *name, const err_type code): silent(false), wasLoaded(false), templateName(name), templateCode(code)
 353 {
 354     assert(name);
 355 }
 356
 357 void
 358 TemplateFile::loadDefault()
 359 {
 360     if (loaded()) // already loaded?
 361         return;
 362
 363     /** test error_directory configured location */
 364     if (Config.errorDirectory) {
 365         char path[MAXPATHLEN];
 366         snprintf(path, sizeof(path), "%s/%s", Config.errorDirectory, templateName.termedBuf());
 367         loadFromFile(path);
 368     }
 369
 370 #if USE_ERR_LOCALES
 371     /** test error_default_language location */
 372     if (!loaded() && Config.errorDefaultLanguage) {
 373         if (!tryLoadTemplate(Config.errorDefaultLanguage)) {
 374             debugs(1, (templateCode < TCP_RESET ? DBG_CRITICAL : 3), "Unable to load default error language files. Reset to backups.");
 375         }
 376     }
 377 #endif
 378
 379     /* test default location if failed (templates == English translation base templates) */
 380     if (!loaded()) {
 381         tryLoadTemplate("templates");
 382     }
 383
 384     /* giving up if failed */
 385     if (!loaded()) {
 386         debugs(1, (templateCode < TCP_RESET ? DBG_CRITICAL : 3), "WARNING: failed to find or read error text file " << templateName);
 387         template_.clear();
 388         setDefault();
 389         wasLoaded = true;
 390     }
 391 }
 392
 393 bool
 394 TemplateFile::tryLoadTemplate(const char *lang)
 395 {
 396     assert(lang);
 397
 398     char path[MAXPATHLEN];
 399     /* TODO: prep the directory path string to prevent snprintf ... */
 400     snprintf(path, sizeof(path), "%s/%s/%s",
 401              DEFAULT_SQUID_ERROR_DIR, lang, templateName.termedBuf());
 402     path[MAXPATHLEN-1] = '\0';
 403
 404     if (loadFromFile(path))
 405         return true;
 406
 407 #if HAVE_GLOB
 408     if ( strlen(lang) == 2) {
 409         /* TODO glob the error directory for sub-dirs matching: <tag> '-*'   */
 410         /* use first result. */
 411         debugs(4,2, HERE << "wildcard fallback errors not coded yet.");
 412     }
 413 #endif
 414
 415     return false;
 416 }
 417
 418 bool
 419 TemplateFile::loadFromFile(const char *path)
 420 {
 421     int fd;
 422     char buf[4096];
 423     ssize_t len;
 424
 425     if (loaded()) // already loaded?
 426         return true;
 427
 428     fd = file_open(path, O_RDONLY | O_TEXT);
 429
 430     if (fd < 0) {
 431         /* with dynamic locale negotiation we may see some failures before a success. */
 432         if (!silent && templateCode < TCP_RESET) {
 433             int xerrno = errno;
 434             debugs(4, DBG_CRITICAL, "ERROR: loading file '" << path << "': " << xstrerr(xerrno));
 435         }
 436         wasLoaded = false;
 437         return wasLoaded;
 438     }
 439
 440     template_.clear();
 441     while ((len = FD_READ_METHOD(fd, buf, sizeof(buf))) > 0) {
 442         template_.append(buf, len);
 443     }
 444
 445     if (len < 0) {
 446         int xerrno = errno;
 447         file_close(fd);
 448         debugs(4, DBG_CRITICAL, MYNAME << "ERROR: failed to fully read: '" << path << "': " << xstrerr(xerrno));
 449         wasLoaded = false;
 450         return false;
 451     }
 452
 453     file_close(fd);
 454
 455     filename = SBuf(path);
 456
 457     if (!parse()) {
 458         debugs(4, DBG_CRITICAL, "ERROR: parsing error in template file: " << path);
 459         wasLoaded = false;
 460         return false;
 461     }
 462
 463     wasLoaded = true;
 464     return wasLoaded;
 465 }
 466
 467 bool strHdrAcptLangGetItem(const String &hdr, char *lang, int langLen, size_t &pos)
 468 {
 469     while (pos < hdr.size()) {
 470
 471         /* skip any initial whitespace. */
 472         while (pos < hdr.size() && xisspace(hdr[pos]))
 473             ++pos;
 474
 475         /*
 476          * Header value format:
 477          *  - sequence of whitespace delimited tags
 478          *  - each tag may suffix with ';'.* which we can ignore.
 479          *  - IFF a tag contains only two characters we can wildcard ANY translations matching: <it> '-'? .*
 480          *    with preference given to an exact match.
 481          */
 482         bool invalid_byte = false;
 483         char *dt = lang;
 484         while (pos < hdr.size() && hdr[pos] != ';' && hdr[pos] != ',' && !xisspace(hdr[pos]) && dt < (lang + (langLen -1)) ) {
 485             if (!invalid_byte) {
 486 #if USE_HTTP_VIOLATIONS
 487                 // if accepting violations we may as well accept some broken browsers
 488                 //  which may send us the right code, wrong ISO formatting.
 489                 if (hdr[pos] == '_')
 490                     *dt = '-';
 491                 else
 492 #endif
 493                     *dt = xtolower(hdr[pos]);
 494                 // valid codes only contain A-Z, hyphen (-) and *
 495                 if (*dt != '-' && *dt != '*' && (*dt < 'a' || *dt > 'z') )
 496                     invalid_byte = true;
 497                 else
 498                     ++dt; // move to next destination byte.
 499             }
 500             ++pos;
 501         }
 502         *dt = '\0'; // nul-terminated the filename content string before system use.
 503
 504         // if we terminated the tag on garbage or ';' we need to skip to the next ',' or end of header.
 505         while (pos < hdr.size() && hdr[pos] != ',')
 506             ++pos;
 507
 508         if (pos < hdr.size() && hdr[pos] == ',')
 509             ++pos;
 510
 511         debugs(4, 9, "STATE: lang=" << lang << ", pos=" << pos << ", buf='" << ((pos < hdr.size()) ? hdr.substr(pos,hdr.size()) : "") << "'");
 512
 513         /* if we found anything we might use, try it. */
 514         if (*lang != '\0' && !invalid_byte)
 515             return true;
 516     }
 517     return false;
 518 }
 519
 520 bool
 521 TemplateFile::loadFor(const HttpRequest *request)
 522 {
 523     String hdr;
 524
 525 #if USE_ERR_LOCALES
 526     if (loaded()) // already loaded?
 527         return true;
 528
 529     if (!request || !request->header.getList(Http::HdrType::ACCEPT_LANGUAGE, &hdr))
 530         return false;
 531
 532     char lang[256];
 533     size_t pos = 0; // current parsing position in header string
 534
 535     debugs(4, 6, HERE << "Testing Header: '" << hdr << "'");
 536
 537     while ( strHdrAcptLangGetItem(hdr, lang, 256, pos) ) {
 538
 539         /* wildcard uses the configured default language */
 540         if (lang[0] == '*' && lang[1] == '\0') {
 541             debugs(4, 6, HERE << "Found language '" << lang << "'. Using configured default.");
 542             return false;
 543         }
 544
 545         debugs(4, 6, HERE << "Found language '" << lang << "', testing for available template");
 546
 547         if (tryLoadTemplate(lang)) {
 548             /* store the language we found for the Content-Language reply header */
 549             errLanguage = lang;
 550             break;
 551         } else if (Config.errorLogMissingLanguages) {
 552             debugs(4, DBG_IMPORTANT, "WARNING: Error Pages Missing Language: " << lang);
 553         }
 554     }
 555 #else
 556     (void)request;
 557 #endif
 558
 559     return loaded();
 560 }
 561
 562 ErrorDynamicPageInfo::ErrorDynamicPageInfo(const int anId, const char *aName, const SBuf &aCfgLocation):
 563     id(anId),
 564     page_name(xstrdup(aName)),
 565     uri(nullptr),
 566     filename(nullptr),
 567     cfgLocation(aCfgLocation),
 568     page_redirect(static_cast<Http::StatusCode>(atoi(page_name)))
 569 {
 570     const char *filenameOrUri = nullptr;
 571     if (xisdigit(*page_name)) {
 572         if (const char *statusCodeEnd = strchr(page_name, ':'))
 573             filenameOrUri = statusCodeEnd + 1;
 574     } else {
 575         assert(!page_redirect);
 576         filenameOrUri = page_name;
 577     }
 578
 579     // Guessed uri, filename, or both values may be nil or malformed.
 580     // They are validated later.
 581     if (!page_redirect) {
 582         if (filenameOrUri && strchr(filenameOrUri, ':')) // looks like a URL
 583             uri = filenameOrUri;
 584         else
 585             filename = filenameOrUri;
 586     }
 587     else if (page_redirect/100 == 3) {
 588         // redirects imply a URL
 589         uri = filenameOrUri;
 590     } else {
 591         // non-redirects imply an error page name
 592         filename = filenameOrUri;
 593     }
 594
 595     const auto info = this; // source code change reduction hack
 596     // TODO: Move and refactor to avoid self_destruct()s in reconfigure.
 597
 598     /* WARNING on redirection status:
 599      * 2xx are permitted, but not documented officially.
 600      * - might be useful for serving static files (PAC etc) in special cases
 601      * 3xx require a URL suitable for Location: header.
 602      * - the current design does not allow for a Location: URI as well as a local file template
 603      *   although this possibility is explicitly permitted in the specs.
 604      * 4xx-5xx require a local file template.
 605      * - sending Location: on these codes with no body is invalid by the specs.
 606      * - current result is Squid crashing or XSS problems as dynamic deny_info load random disk files.
 607      * - a future redesign of the file loading may result in loading remote objects sent inline as local body.
 608      */
 609     if (info->page_redirect == Http::scNone)
 610         ; // special case okay.
 611     else if (info->page_redirect < 200 || info->page_redirect > 599) {
 612         // out of range
 613         debugs(0, DBG_CRITICAL, "FATAL: status " << info->page_redirect << " is not valid on '" << page_name << "'");
 614         self_destruct();
 615     } else if ( /* >= 200 && */ info->page_redirect < 300 && strchr(&(page_name[4]), ':')) {
 616         // 2xx require a local template file
 617         debugs(0, DBG_CRITICAL, "FATAL: status " << info->page_redirect << " requires a template on '" << page_name << "'");
 618         self_destruct();
 619     } else if (info->page_redirect >= 300 && info->page_redirect <= 399 && !strchr(&(page_name[4]), ':')) {
 620         // 3xx require an absolute URL
 621         debugs(0, DBG_CRITICAL, "FATAL: status " << info->page_redirect << " requires a URL on '" << page_name << "'");
 622         self_destruct();
 623     } else if (info->page_redirect >= 400 /* && <= 599 */ && strchr(&(page_name[4]), ':')) {
 624         // 4xx/5xx require a local template file
 625         debugs(0, DBG_CRITICAL, "FATAL: status " << info->page_redirect << " requires a template on '" << page_name << "'");
 626         self_destruct();
 627     }
 628     // else okay.
 629 }
 630
 631 /// \ingroup ErrorPageInternal
 632 static int
 633 errorPageId(const char *page_name)
 634 {
 635     for (int i = 0; i < ERR_MAX; ++i) {
 636         if (strcmp(err_type_str[i], page_name) == 0)
 637             return i;
 638     }
 639
 640     for (size_t j = 0; j < ErrorDynamicPages.size(); ++j) {
 641         if (strcmp(ErrorDynamicPages[j]->page_name, page_name) == 0)
 642             return j + ERR_MAX;
 643     }
 644
 645     return ERR_NONE;
 646 }
 647
 648 err_type
 649 errorReservePageId(const char *page_name, const SBuf &cfgLocation)
 650 {
 651     int id = errorPageId(page_name);
 652
 653     if (id == ERR_NONE) {
 654         id = ERR_MAX + ErrorDynamicPages.size();
 655         const auto info = new ErrorDynamicPageInfo(id, page_name, cfgLocation);
 656         ErrorDynamicPages.push_back(info);
 657     }
 658
 659     return (err_type)id;
 660 }
 661
 662 /// \ingroup ErrorPageInternal
 663 const char *
 664 errorPageName(int pageId)
 665 {
 666     if (pageId >= ERR_NONE && pageId < ERR_MAX)     /* common case */
 667         return err_type_str[pageId];
 668
 669     if (pageId >= ERR_MAX && pageId - ERR_MAX < (ssize_t)ErrorDynamicPages.size())
 670         return ErrorDynamicPages[pageId - ERR_MAX]->page_name;
 671
 672     return "ERR_UNKNOWN";   /* should not happen */
 673 }
 674
 675 ErrorState *
 676 ErrorState::NewForwarding(err_type type, HttpRequestPointer &request, const AccessLogEntry::Pointer &ale)
 677 {
 678     const Http::StatusCode status = (request && request->flags.needValidation) ?
 679                                     Http::scGatewayTimeout : Http::scServiceUnavailable;
 680     return new ErrorState(type, status, request.getRaw(), ale);
 681 }
 682
 683 ErrorState::ErrorState(err_type t) :
 684     type(t),
 685     page_id(t),
 686     callback(nullptr)
 687 {
 688 }
 689
 690 ErrorState::ErrorState(err_type t, Http::StatusCode status, HttpRequest * req, const AccessLogEntry::Pointer &anAle) :
 691     ErrorState(t)
 692 {
 693     if (page_id >= ERR_MAX && ErrorDynamicPages[page_id - ERR_MAX]->page_redirect != Http::scNone)
 694         httpStatus = ErrorDynamicPages[page_id - ERR_MAX]->page_redirect;
 695     else
 696         httpStatus = status;
 697
 698     if (req) {
 699         request = req;
 700         src_addr = req->client_addr;
 701     }
 702
 703     ale = anAle;
 704 }
 705
 706 ErrorState::ErrorState(HttpRequest * req, HttpReply *errorReply) :
 707     ErrorState(ERR_RELAY_REMOTE)
 708 {
 709     Must(errorReply);
 710     response_ = errorReply;
 711     httpStatus = errorReply->sline.status();
 712
 713     if (req) {
 714         request = req;
 715         src_addr = req->client_addr;
 716     }
 717 }
 718
 719 void
 720 errorAppendEntry(StoreEntry * entry, ErrorState * err)
 721 {
 722     assert(entry->mem_obj != NULL);
 723     assert (entry->isEmpty());
 724     debugs(4, 4, "storing " << err << " in " << *entry);
 725
 726     if (entry->store_status != STORE_PENDING) {
 727         debugs(4, 2, "Skipping error page due to store_status: " << entry->store_status);
 728         /*
 729          * If the entry is not STORE_PENDING, then no clients
 730          * care about it, and we don't need to generate an
 731          * error message
 732          */
 733         assert(EBIT_TEST(entry->flags, ENTRY_ABORTED));
 734         assert(entry->mem_obj->nclients == 0);
 735         delete err;
 736         return;
 737     }
 738
 739     if (err->page_id == TCP_RESET) {
 740         if (err->request) {
 741             debugs(4, 2, "RSTing this reply");
 742             err->request->flags.resetTcp = true;
 743         }
 744     }
 745
 746     entry->storeErrorResponse(err->BuildHttpReply());
 747     delete err;
 748 }
 749
 750 void
 751 errorSend(const Comm::ConnectionPointer &conn, ErrorState * err)
 752 {
 753     debugs(4, 3, conn << ", err=" << err);
 754     assert(Comm::IsConnOpen(conn));
 755
 756     HttpReplyPointer rep(err->BuildHttpReply());
 757
 758     MemBuf *mb = rep->pack();
 759     AsyncCall::Pointer call = commCbCall(78, 5, "errorSendComplete",
 760                                          CommIoCbPtrFun(&errorSendComplete, err));
 761     Comm::Write(conn, mb, call);
 762     delete mb;
 763 }
 764
 765 /**
 766  \ingroup ErrorPageAPI
 767  *
 768  * Called by commHandleWrite() after data has been written
 769  * to the client socket.
 770  *
 771  \note If there is a callback, the callback is responsible for
 772  *     closing the FD, otherwise we do it ourselves.
 773  */
 774 static void
 775 errorSendComplete(const Comm::ConnectionPointer &conn, char *, size_t size, Comm::Flag errflag, int, void *data)
 776 {
 777     ErrorState *err = static_cast<ErrorState *>(data);
 778     debugs(4, 3, HERE << conn << ", size=" << size);
 779
 780     if (errflag != Comm::ERR_CLOSING) {
 781         if (err->callback) {
 782             debugs(4, 3, "errorSendComplete: callback");
 783             err->callback(conn->fd, err->callback_data, size);
 784         } else {
 785             debugs(4, 3, "errorSendComplete: comm_close");
 786             conn->close();
 787         }
 788     }
 789
 790     delete err;
 791 }
 792
 793 ErrorState::~ErrorState()
 794 {
 795     safe_free(redirect_url);
 796     safe_free(url);
 797     safe_free(request_hdrs);
 798     wordlistDestroy(&ftp.server_msg);
 799     safe_free(ftp.request);
 800     safe_free(ftp.reply);
 801     safe_free(err_msg);
 802 #if USE_ERR_LOCALES
 803     if (err_language != Config.errorDefaultLanguage)
 804 #endif
 805         safe_free(err_language);
 806 }
 807
 808 int
 809 ErrorState::Dump(MemBuf * mb)
 810 {
 811     MemBuf str;
 812     char ntoabuf[MAX_IPSTRLEN];
 813
 814     str.reset();
 815     /* email subject line */
 816     str.appendf("CacheErrorInfo - %s", errorPageName(type));
 817     mb->appendf("?subject=%s", rfc1738_escape_part(str.buf));
 818     str.reset();
 819     /* email body */
 820     str.appendf("CacheHost: %s\r\n", getMyHostname());
 821     /* - Err Msgs */
 822     str.appendf("ErrPage: %s\r\n", errorPageName(type));
 823
 824     if (xerrno) {
 825         str.appendf("Err: (%d) %s\r\n", xerrno, strerror(xerrno));
 826     } else {
 827         str.append("Err: [none]\r\n", 13);
 828     }
 829 #if USE_AUTH
 830     if (auth_user_request.getRaw() && auth_user_request->denyMessage())
 831         str.appendf("Auth ErrMsg: %s\r\n", auth_user_request->denyMessage());
 832 #endif
 833     if (dnsError.size() > 0)
 834         str.appendf("DNS ErrMsg: %s\r\n", dnsError.termedBuf());
 835
 836     /* - TimeStamp */
 837     str.appendf("TimeStamp: %s\r\n\r\n", mkrfc1123(squid_curtime));
 838
 839     /* - IP stuff */
 840     str.appendf("ClientIP: %s\r\n", src_addr.toStr(ntoabuf,MAX_IPSTRLEN));
 841
 842     if (request && request->hier.host[0] != '\0') {
 843         str.appendf("ServerIP: %s\r\n", request->hier.host);
 844     }
 845
 846     str.append("\r\n", 2);
 847     /* - HTTP stuff */
 848     str.append("HTTP Request:\r\n", 15);
 849     if (request) {
 850         str.appendf(SQUIDSBUFPH " " SQUIDSBUFPH " %s/%d.%d\n",
 851                     SQUIDSBUFPRINT(request->method.image()),
 852                     SQUIDSBUFPRINT(request->url.path()),
 853                     AnyP::ProtocolType_str[request->http_ver.protocol],
 854                     request->http_ver.major, request->http_ver.minor);
 855         request->header.packInto(&str);
 856     }
 857
 858     str.append("\r\n", 2);
 859     /* - FTP stuff */
 860
 861     if (ftp.request) {
 862         str.appendf("FTP Request: %s\r\n", ftp.request);
 863         str.appendf("FTP Reply: %s\r\n", (ftp.reply? ftp.reply:"[none]"));
 864         str.append("FTP Msg: ", 9);
 865         wordlistCat(ftp.server_msg, &str);
 866         str.append("\r\n", 2);
 867     }
 868
 869     str.append("\r\n", 2);
 870     mb->appendf("&body=%s", rfc1738_escape_part(str.buf));
 871     str.clean();
 872     return 0;
 873 }
 874
 875 /// \ingroup ErrorPageInternal
 876 #define CVT_BUF_SZ 512
 877
 878 void
 879 ErrorState::compileLogformatCode(Build &build)
 880 {
 881     assert(LogformatMagic.cmp(build.input, LogformatMagic.length()) == 0);
 882
 883     try {
 884         const auto logformat = build.input + LogformatMagic.length();
 885
 886         // Logformat supports undocumented "external" encoding specifications
 887         // like [%>h] or "%<a". To preserve the possibility of extending
 888         // @Squid{} syntax to non-logformat sequences, we require logformat
 889         // sequences to start with '%'. This restriction does not limit
 890         // logformat quoting abilities. TODO: Deprecate "external" encoding?
 891         if (*logformat != '%')
 892             throw TexcHere("logformat expressions that do not start with % are not supported");
 893
 894         static MemBuf result;
 895         result.reset();
 896         const auto logformatLen = Format::AssembleOne(logformat, result, ale);
 897         assert(logformatLen > 0);
 898         const auto closure = logformat + logformatLen;
 899         if (*closure != '}')
 900             throw TexcHere("Missing closing brace (})");
 901         build.output.append(result.content(), result.contentSize());
 902         build.input = closure + 1;
 903         return;
 904     } catch (...) {
 905         noteBuildError("Bad @Squid{logformat} sequence", build.input);
 906     }
 907
 908     // we cannot recover reliably so stop interpreting the rest of input
 909     const auto remainingSize = strlen(build.input);
 910     build.output.append(build.input, remainingSize);
 911     build.input += remainingSize;
 912 }
 913
 914 void
 915 ErrorState::compileLegacyCode(Build &build)
 916 {
 917     static MemBuf mb;
 918     const char *p = NULL;   /* takes priority over mb if set */
 919     int do_quote = 1;
 920     int no_urlescape = 0;       /* if true then item is NOT to be further URL-encoded */
 921     char ntoabuf[MAX_IPSTRLEN];
 922
 923     mb.reset();
 924
 925     const auto &building_deny_info_url = build.building_deny_info_url; // a change reduction hack
 926
 927     const auto letter = build.input[1];
 928
 929     switch (letter) {
 930
 931     case 'a':
 932 #if USE_AUTH
 933         if (request && request->auth_user_request)
 934             p = request->auth_user_request->username();
 935         if (!p)
 936 #endif
 937             p = "-";
 938         break;
 939
 940     case 'A':
 941         // TODO: When/if we get ALE here, pass it as well
 942         if (const auto addr = FindListeningPortAddress(request.getRaw(), nullptr))
 943             mb.appendf("%s", addr->toStr(ntoabuf, MAX_IPSTRLEN));
 944         else
 945             p = "-";
 946         break;
 947
 948     case 'b':
 949         mb.appendf("%u", getMyPort());
 950         break;
 951
 952     case 'B':
 953         if (building_deny_info_url) break;
 954         if (request) {
 955             const SBuf &tmp = Ftp::UrlWith2f(request.getRaw());
 956             mb.append(tmp.rawContent(), tmp.length());
 957         } else
 958             p = "[no URL]";
 959         break;
 960
 961     case 'c':
 962         if (building_deny_info_url) break;
 963         p = errorPageName(type);
 964         break;
 965
 966     case 'D':
 967         if (!build.allowRecursion)
 968             p = "%D";  // if recursion is not allowed, do not convert
 969         else if (detail) {
 970             auto rawDetail = detail->verbose(request);
 971             // XXX: Performance regression. c_str() reallocates
 972             const auto compiledDetail = compileBody(rawDetail.c_str(), false);
 973             mb.append(compiledDetail.rawContent(), compiledDetail.length());
 974             do_quote = 0;
 975         }
 976         if (!mb.contentSize())
 977             mb.append("[No Error Detail]", 17);
 978         break;
 979
 980     case 'e':
 981         mb.appendf("%d", xerrno);
 982         break;
 983
 984     case 'E':
 985         if (xerrno)
 986             mb.appendf("(%d) %s", xerrno, strerror(xerrno));
 987         else
 988             mb.append("[No Error]", 10);
 989         break;
 990
 991     case 'f':
 992         if (building_deny_info_url) break;
 993         /* FTP REQUEST LINE */
 994         if (ftp.request)
 995             p = ftp.request;
 996         else
 997             p = "nothing";
 998         break;
 999
1000     case 'F':
1001         if (building_deny_info_url) break;
1002         /* FTP REPLY LINE */
1003         if (ftp.reply)
1004             p = ftp.reply;
1005         else
1006             p = "nothing";
1007         break;
1008
1009     case 'g':
1010         if (building_deny_info_url) break;
1011         /* FTP SERVER RESPONSE */
1012         if (ftp.listing) {
1013             mb.append(ftp.listing->content(), ftp.listing->contentSize());
1014             do_quote = 0;
1015         } else if (ftp.server_msg) {
1016             wordlistCat(ftp.server_msg, &mb);
1017         }
1018         break;
1019
1020     case 'h':
1021         mb.appendf("%s", getMyHostname());
1022         break;
1023
1024     case 'H':
1025         if (request) {
1026             if (request->hier.host[0] != '\0') // if non-empty string.
1027                 p = request->hier.host;
1028             else
1029                 p = request->url.host();
1030         } else if (!building_deny_info_url)
1031             p = "[unknown host]";
1032         break;
1033
1034     case 'i':
1035         mb.appendf("%s", src_addr.toStr(ntoabuf,MAX_IPSTRLEN));
1036         break;
1037
1038     case 'I':
1039         if (request && request->hier.tcpServer)
1040             p = request->hier.tcpServer->remote.toStr(ntoabuf,MAX_IPSTRLEN);
1041         else if (!building_deny_info_url)
1042             p = "[unknown]";
1043         break;
1044
1045     case 'l':
1046         if (building_deny_info_url) break;
1047         mb.append(error_stylesheet.content(), error_stylesheet.contentSize());
1048         do_quote = 0;
1049         break;
1050
1051     case 'L':
1052         if (building_deny_info_url) break;
1053         if (Config.errHtmlText) {
1054             mb.appendf("%s", Config.errHtmlText);
1055             do_quote = 0;
1056         } else
1057             p = "[not available]";
1058         break;
1059
1060     case 'm':
1061         if (building_deny_info_url) break;
1062 #if USE_AUTH
1063         if (auth_user_request.getRaw())
1064             p = auth_user_request->denyMessage("[not available]");
1065         else
1066             p = "[not available]";
1067 #else
1068         p = "-";
1069 #endif
1070         break;
1071
1072     case 'M':
1073         if (request) {
1074             const SBuf &m = request->method.image();
1075             mb.append(m.rawContent(), m.length());
1076         } else if (!building_deny_info_url)
1077             p = "[unknown method]";
1078         break;
1079
1080     case 'O':
1081         if (!building_deny_info_url)
1082             do_quote = 0;
1083     /* [[fallthrough]] */
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 (detail) {
1208             const auto brief = detail->brief();
1209             mb.append(brief.rawContent(), brief.length());
1210         } else if (!building_deny_info_url) {
1211             p = "[Unknown Error Code]";
1212         }
1213         break;
1214
1215     case 'z':
1216         if (building_deny_info_url) break;
1217         if (dnsError.size() > 0)
1218             p = dnsError.termedBuf();
1219         else if (ftp.cwd_msg)
1220             p = ftp.cwd_msg;
1221         else
1222             p = "[unknown]";
1223         break;
1224
1225     case 'Z':
1226         if (building_deny_info_url) break;
1227         if (err_msg)
1228             p = err_msg;
1229         else
1230             p = "[unknown]";
1231         break;
1232
1233     case '%':
1234         p = "%";
1235         break;
1236
1237     default:
1238         if (building_deny_info_url)
1239             bypassBuildErrorXXX("Unsupported deny_info %code", build.input);
1240         else if (letter != ';')
1241             bypassBuildErrorXXX("Unsupported error page %code", build.input);
1242         // else too many "font-size: 100%;" template errors to report
1243
1244         mb.append(build.input, 2);
1245         do_quote = 0;
1246         break;
1247     }
1248
1249     if (!p)
1250         p = mb.buf;     /* do not use mb after this assignment! */
1251
1252     assert(p);
1253
1254     debugs(4, 3, "%" << letter << " --> '" << p << "'" );
1255
1256     if (do_quote)
1257         p = html_quote(p);
1258
1259     if (building_deny_info_url && !no_urlescape)
1260         p = rfc1738_escape_part(p);
1261
1262     // TODO: Optimize by replacing mb with direct build.output usage.
1263     build.output.append(p, strlen(p));
1264     build.input += 2;
1265 }
1266
1267 void
1268 ErrorState::validate()
1269 {
1270     if (const auto urlTemplate = ErrorPage::IsDenyInfoUri(page_id)) {
1271         (void)compile(urlTemplate, true, true);
1272     } else {
1273         assert(page_id > ERR_NONE);
1274         assert(page_id < error_page_count);
1275         (void)compileBody(error_text[page_id], true);
1276     }
1277 }
1278
1279 HttpReply *
1280 ErrorState::BuildHttpReply()
1281 {
1282     if (response_)
1283         return response_.getRaw();
1284
1285     HttpReply *rep = new HttpReply;
1286     const char *name = errorPageName(page_id);
1287     /* no LMT for error pages; error pages expire immediately */
1288
1289     if (const auto urlTemplate = ErrorPage::IsDenyInfoUri(page_id)) {
1290         /* Redirection */
1291         Http::StatusCode status = Http::scFound;
1292         // Use configured 3xx reply status if set.
1293         if (name[0] == '3')
1294             status = httpStatus;
1295         else {
1296             // Use 307 for HTTP/1.1 non-GET/HEAD requests.
1297             if (request && request->method != Http::METHOD_GET && request->method != Http::METHOD_HEAD && request->http_ver >= Http::ProtocolVersion(1,1))
1298                 status = Http::scTemporaryRedirect;
1299         }
1300
1301         rep->setHeaders(status, NULL, "text/html;charset=utf-8", 0, 0, -1);
1302
1303         if (request) {
1304             auto location = compile(urlTemplate, true, true);
1305             rep->header.putStr(Http::HdrType::LOCATION, location.c_str());
1306         }
1307
1308         httpHeaderPutStrf(&rep->header, Http::HdrType::X_SQUID_ERROR, "%d %s", httpStatus, "Access Denied");
1309     } else {
1310         const auto body = buildBody();
1311         rep->setHeaders(httpStatus, NULL, "text/html;charset=utf-8", body.length(), 0, -1);
1312         /*
1313          * include some information for downstream caches. Implicit
1314          * replaceable content. This isn't quite sufficient. xerrno is not
1315          * necessarily meaningful to another system, so we really should
1316          * expand it. Additionally, we should identify ourselves. Someone
1317          * might want to know. Someone _will_ want to know OTOH, the first
1318          * X-CACHE-MISS entry should tell us who.
1319          */
1320         httpHeaderPutStrf(&rep->header, Http::HdrType::X_SQUID_ERROR, "%s %d", name, xerrno);
1321
1322 #if USE_ERR_LOCALES
1323         /*
1324          * If error page auto-negotiate is enabled in any way, send the Vary.
1325          * RFC 2616 section 13.6 and 14.44 says MAY and SHOULD do this.
1326          * We have even better reasons though:
1327          * see http://wiki.squid-cache.org/KnowledgeBase/VaryNotCaching
1328          */
1329         if (!Config.errorDirectory) {
1330             /* We 'negotiated' this ONLY from the Accept-Language. */
1331             rep->header.delById(Http::HdrType::VARY);
1332             rep->header.putStr(Http::HdrType::VARY, "Accept-Language");
1333         }
1334
1335         /* add the Content-Language header according to RFC section 14.12 */
1336         if (err_language) {
1337             rep->header.putStr(Http::HdrType::CONTENT_LANGUAGE, err_language);
1338         } else
1339 #endif /* USE_ERROR_LOCALES */
1340         {
1341             /* default templates are in English */
1342             /* language is known unless error_directory override used */
1343             if (!Config.errorDirectory)
1344                 rep->header.putStr(Http::HdrType::CONTENT_LANGUAGE, "en");
1345         }
1346
1347         rep->body.set(body);
1348     }
1349
1350     // Make sure error codes get back to the client side for logging and
1351     // error tracking.
1352     if (request) {
1353         if (detail)
1354             request->detailError(type, detail);
1355         else
1356             request->detailError(type, SysErrorDetail::NewIfAny(xerrno));
1357     }
1358
1359     return rep;
1360 }
1361
1362 SBuf
1363 ErrorState::buildBody()
1364 {
1365     assert(page_id > ERR_NONE && page_id < error_page_count);
1366
1367 #if USE_ERR_LOCALES
1368     /** error_directory option in squid.conf overrides translations.
1369      * Custom errors are always found either in error_directory or the templates directory.
1370      * Otherwise locate the Accept-Language header
1371      */
1372     if (!Config.errorDirectory && page_id < ERR_MAX) {
1373         if (err_language && err_language != Config.errorDefaultLanguage)
1374             safe_free(err_language);
1375
1376         ErrorPageFile localeTmpl(err_type_str[page_id], static_cast<err_type>(page_id));
1377         if (localeTmpl.loadFor(request.getRaw())) {
1378             inputLocation = localeTmpl.filename;
1379             assert(localeTmpl.language());
1380             err_language = xstrdup(localeTmpl.language());
1381             return compileBody(localeTmpl.text(), true);
1382         }
1383     }
1384 #endif /* USE_ERR_LOCALES */
1385
1386     /** \par
1387      * If client-specific error templates are not enabled or available.
1388      * fall back to the old style squid.conf settings.
1389      */
1390 #if USE_ERR_LOCALES
1391     if (!Config.errorDirectory)
1392         err_language = Config.errorDefaultLanguage;
1393 #endif
1394     debugs(4, 2, "No existing error page language negotiated for " << this << ". Using default error file.");
1395     return compileBody(error_text[page_id], true);
1396 }
1397
1398 SBuf
1399 ErrorState::compileBody(const char *input, bool allowRecursion)
1400 {
1401     return compile(input, false, allowRecursion);
1402 }
1403
1404 SBuf
1405 ErrorState::compile(const char *input, bool building_deny_info_url, bool allowRecursion)
1406 {
1407     assert(input);
1408
1409     Build build;
1410     build.building_deny_info_url = building_deny_info_url;
1411     build.allowRecursion = allowRecursion;
1412     build.input = input;
1413
1414     auto blockStart = build.input;
1415     while (const auto letter = *build.input) {
1416         if (letter == '%') {
1417             build.output.append(blockStart, build.input - blockStart);
1418             compileLegacyCode(build);
1419             blockStart = build.input;
1420         }
1421         else if (letter == '@' && LogformatMagic.cmp(build.input, LogformatMagic.length()) == 0) {
1422             build.output.append(blockStart, build.input - blockStart);
1423             compileLogformatCode(build);
1424             blockStart = build.input;
1425         } else {
1426             ++build.input;
1427         }
1428     }
1429     build.output.append(blockStart, build.input - blockStart);
1430     return build.output;
1431 }
1432
1433 /// react to a compile() error
1434 /// \param msg  description of what went wrong
1435 /// \param near  approximate start of the problematic input
1436 /// \param  forceBypass whether detection of this error was introduced late,
1437 /// after old configurations containing this error could have been
1438 /// successfully validated and deployed (i.e. the admin may not be
1439 /// able to fix this newly detected but old problem quickly)
1440 void
1441 ErrorState::noteBuildError_(const char *msg, const char *near, const bool forceBypass)
1442 {
1443     using ErrorPage::BuildErrorPrinter;
1444     const auto runtime = !starting_up;
1445     if (runtime || forceBypass) {
1446         // swallow this problem because the admin may not be (and/or the page
1447         // building code is not) ready to handle throwing consequences
1448
1449         static unsigned int seenErrors = 0;
1450         ++seenErrors;
1451
1452         const auto debugLevel =
1453             (seenErrors > 100) ? DBG_DATA:
1454             (starting_up || reconfiguring) ? DBG_CRITICAL:
1455             3; // most other errors have been reported as configuration errors
1456
1457         // Error fatality depends on the error context: Reconfiguration errors
1458         // are, like startup ones, DBG_CRITICAL but will never become FATAL.
1459         if (starting_up && seenErrors <= 10)
1460             debugs(4, debugLevel, "WARNING: The following configuration error will be fatal in future Squid versions");
1461
1462         debugs(4, debugLevel, "ERROR: " << BuildErrorPrinter(inputLocation, page_id, msg, near));
1463     } else {
1464         throw TexcHere(ToSBuf(BuildErrorPrinter(inputLocation, page_id, msg, near)));
1465     }
1466 }
1467
1468 /* ErrorPage::BuildErrorPrinter */
1469
1470 std::ostream &
1471 ErrorPage::BuildErrorPrinter::printLocation(std::ostream &os) const {
1472     if (!inputLocation.isEmpty())
1473         return os << inputLocation;
1474
1475     if (page_id < ERR_NONE || page_id >= error_page_count)
1476         return os << "[error page " << page_id << "]"; // should not happen
1477
1478     if (page_id < ERR_MAX)
1479         return os << err_type_str[page_id];
1480
1481     return os << "deny_info " << ErrorDynamicPages.at(page_id - ERR_MAX)->page_name;
1482 }
1483
1484 std::ostream &
1485 ErrorPage::BuildErrorPrinter::print(std::ostream &os) const {
1486     printLocation(os) << ": " << msg << " near ";
1487
1488     // TODO: Add support for prefix printing to Raw
1489     const size_t maxContextLength = 15; // plus "..."
1490     if (strlen(near) > maxContextLength) {
1491         os.write(near, maxContextLength);
1492         os << "...";
1493     } else {
1494         os << near;
1495     }
1496
1497     // XXX: We should not be converting (inner) exception to text if we are
1498     // going to throw again. See "add arbitrary (re)thrower-supplied details"
1499     // TODO in TextException.h for a long-term in-catcher solution.
1500     if (std::current_exception())
1501         os << "\n    additional info: " << CurrentException;
1502
1503     return os;
1504 }
1505
1506 /// add error page template to the global index
1507 static void
1508 ErrorPage::ImportStaticErrorText(const int page_id, const char *text, const SBuf &inputLocation)
1509 {
1510     assert(!error_text[page_id]);
1511     error_text[page_id] = xstrdup(text);
1512     ValidateStaticError(page_id, inputLocation);
1513 }
1514
1515 /// validate static error page
1516 static void
1517 ErrorPage::ValidateStaticError(const int page_id, const SBuf &inputLocation)
1518 {
1519     // Supplying nil ALE pointer limits validation to logformat %code
1520     // recognition by Format::Token::parse(). This is probably desirable
1521     // because actual %code assembly is slow and should not affect validation
1522     // when our ALE cannot have any real data (this code is not associated
1523     // with any real transaction).
1524     ErrorState anErr(err_type(page_id), Http::scNone, nullptr, nullptr);
1525     anErr.inputLocation = inputLocation;
1526     anErr.validate();
1527 }
1528
1529 std::ostream &
1530 operator <<(std::ostream &os, const ErrorState *err)
1531 {
1532     if (err)
1533         os << errorPageName(err->page_id);
1534     else
1535         os << "[none]";
1536     return os;
1537 }
1538