src/errorpage.h

   1 /*
   2  * Copyright (C) 1996-2020 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 /* DEBUG: section 04    Error Generation */
  10
  11 #ifndef   SQUID_ERRORPAGE_H
  12 #define   SQUID_ERRORPAGE_H
  13
  14 #include "cbdata.h"
  15 #include "comm/forward.h"
  16 #include "err_detail_type.h"
  17 #include "err_type.h"
  18 #include "http/forward.h"
  19 #include "http/StatusCode.h"
  20 #include "ip/Address.h"
  21 #include "log/forward.h"
  22 #include "sbuf/SBuf.h"
  23 #include "SquidString.h"
  24 /* auth/UserRequest.h is empty unless USE_AUTH is defined */
  25 #include "auth/UserRequest.h"
  26 #if USE_OPENSSL
  27 #include "ssl/ErrorDetail.h"
  28 #endif
  29
  30 /// error page callback
  31 typedef void ERCB(int fd, void *, size_t);
  32
  33 /**
  34  \defgroup ErrorPageAPI Error Pages API
  35  \ingroup Components
  36  \section ErrorPageStringCodes Error Page % codes for text insertion.
  37  *
  38  \verbatim
  39    a - User identity                            x
  40    A - Local listening IP address               x
  41    B - URL with FTP %2f hack                    x
  42    c - Squid error code                         x
  43    d - seconds elapsed since request received   x
  44    D - Error details                            x
  45    e - errno                                    x
  46    E - strerror()                               x
  47    f - FTP request line                         x
  48    F - FTP reply line                           x
  49    g - FTP server message                       x
  50    h - cache hostname                           x
  51    H - server host name                         x
  52    i - client IP address                        x
  53    I - server IP address                        x
  54    l - HREF link for CSS stylesheet inclusion   x
  55    L - HREF link for more info/contact          x
  56    M - Request Method                           x
  57    m - Error message returned by auth helper    x
  58    o - Message returned external acl helper     x
  59    p - URL port #                               x
  60    P - Protocol                                 x
  61    R - Full HTTP Request                        x
  62    S - squid signature from ERR_SIGNATURE       x
  63    s - caching proxy software with version      x
  64    t - local time                               x
  65    T - UTC                                      x
  66    U - URL without password                     x
  67    u - URL with password                        x
  68    w - cachemgr email address                   x
  69    W - error data (to be included in the mailto links)
  70    x - error name                               x
  71    z - dns server error message                 x
  72    Z - Preformatted error message               x
  73  \endverbatim
  74  *
  75  * Plus logformat %codes embedded using @Squid{%logformat_code} syntax.
  76  */
  77
  78 class MemBuf;
  79 class StoreEntry;
  80 class wordlist;
  81
  82 namespace ErrorPage {
  83
  84 class Build;
  85
  86 } // namespace ErrorPage
  87
  88 /// \ingroup ErrorPageAPI
  89 class ErrorState
  90 {
  91     CBDATA_CLASS(ErrorState);
  92
  93 public:
  94     /// creates an error of type other than ERR_RELAY_REMOTE
  95     ErrorState(err_type type, Http::StatusCode, HttpRequest * request, const AccessLogEntryPointer &al);
  96     ErrorState() = delete; // not implemented.
  97
  98     /// creates an ERR_RELAY_REMOTE error
  99     ErrorState(HttpRequest * request, HttpReply *);
 100
 101     ~ErrorState();
 102
 103     /// Creates a general request forwarding error with the right http_status.
 104     static ErrorState *NewForwarding(err_type, HttpRequestPointer &, const AccessLogEntryPointer &);
 105
 106     /**
 107      * Allocates and initializes an error response
 108      */
 109     HttpReply *BuildHttpReply(void);
 110
 111     /// set error type-specific detail code
 112     void detailError(int dCode) {detailCode = dCode;}
 113
 114     /// ensures that a future BuildHttpReply() is likely to succeed
 115     void validate();
 116
 117     /// the source of the error template (for reporting purposes)
 118     SBuf inputLocation;
 119
 120 private:
 121     typedef ErrorPage::Build Build;
 122
 123     /// initializations shared by public constructors
 124     explicit ErrorState(err_type type);
 125
 126     /// locates the right error page template for this error and compiles it
 127     SBuf buildBody();
 128
 129     /// compiles error page or error detail template (i.e. anything but deny_url)
 130     /// \param input  the template text to be compiled
 131     /// \param allowRecursion  whether to compile %codes which produce %codes
 132     SBuf compileBody(const char *text, bool allowRecursion);
 133
 134     /// compile a single-letter %code like %D
 135     void compileLegacyCode(Build &build);
 136
 137     /// compile @Squid{%code} sequence containing a single logformat %code
 138     void compileLogformatCode(Build &build);
 139
 140     /// replaces all legacy and logformat %codes in the given input
 141     /// \param input  the template text to be converted
 142     /// \param building_deny_info_url  whether input is a deny_info URL parameter
 143     /// \param allowRecursion  whether to compile %codes which produce %codes
 144     /// \returns the given input with all %codes substituted
 145     SBuf compile(const char *input, bool building_deny_info_url, bool allowRecursion);
 146
 147     /// React to a compile() error, throwing if buildContext allows.
 148     /// \param msg description of what went wrong
 149     /// \param near approximate start of the problematic input
 150     void noteBuildError(const char *msg, const char *near) {
 151         noteBuildError_(msg, near, false);
 152     }
 153
 154     /// Note a compile() error but do not throw for backwards
 155     /// compatibility with older configurations that may have such errors.
 156     /// Should eventually be replaced with noteBuildError().
 157     /// \param msg description of what went wrong
 158     /// \param near approximate start of the problematic input
 159     void bypassBuildErrorXXX(const char *msg, const char *near) {
 160         noteBuildError_(msg, near, true);
 161     }
 162
 163     /**
 164      * CacheManager / Debug dump of the ErrorState object.
 165      * Writes output into the given MemBuf.
 166      \retval 0 successful completion.
 167      */
 168     int Dump(MemBuf * mb);
 169
 170 public:
 171     err_type type = ERR_NONE;
 172     int page_id = ERR_NONE;
 173     char *err_language = nullptr;
 174     Http::StatusCode httpStatus = Http::scNone;
 175 #if USE_AUTH
 176     Auth::UserRequest::Pointer auth_user_request;
 177 #endif
 178     HttpRequestPointer request;
 179     char *url = nullptr;
 180     int xerrno = 0;
 181     unsigned short port = 0;
 182     String dnsError; ///< DNS lookup error message
 183     time_t ttl = 0;
 184
 185     Ip::Address src_addr;
 186     char *redirect_url = nullptr;
 187     ERCB *callback;
 188     void *callback_data = nullptr;
 189
 190     struct {
 191         wordlist *server_msg = nullptr;
 192         char *request = nullptr;
 193         char *reply = nullptr;
 194         char *cwd_msg = nullptr;
 195         MemBuf *listing = nullptr;
 196     } ftp;
 197
 198     char *request_hdrs = nullptr;
 199     char *err_msg = nullptr; /* Preformatted error message from the cache */
 200
 201     AccessLogEntryPointer ale; ///< transaction details (or nil)
 202
 203 #if USE_OPENSSL
 204     Ssl::ErrorDetail *detail = nullptr;
 205 #endif
 206     /// type-specific detail about the transaction error;
 207     /// overwrites xerrno; overwritten by detail, if any.
 208     int detailCode = ERR_DETAIL_NONE;
 209
 210     HttpReplyPointer response_;
 211
 212 private:
 213     void noteBuildError_(const char *msg, const char *near, const bool forceBypass);
 214
 215     static const SBuf LogformatMagic; ///< marks each embedded logformat entry
 216 };
 217
 218 /**
 219  \ingroup ErrorPageAPI
 220  *
 221  * This function finds the error messages formats, and stores
 222  * them in error_text[]
 223  *
 224  \par Global effects:
 225  *            error_text[] - is modified
 226  */
 227 void errorInitialize(void);
 228
 229 /// \ingroup ErrorPageAPI
 230 void errorClean(void);
 231
 232 /**
 233  * \ingroup ErrorPageAPI
 234  *
 235  * This function generates a error page from the info contained
 236  * by err and then sends it to the client.
 237  * The callback function errorSendComplete() is called after
 238  * the page has been written to the client (clientConn).
 239  * errorSendComplete() deallocates err.  We need to add
 240  * err to the cbdata because comm_write() requires it
 241  * for all callback data pointers.
 242  *
 243  \note normally errorSend() should only be called from
 244  *     routines in ssl.c and pass.c, where we don't have any
 245  *     StoreEntry's.  In client_side.c we must allocate a StoreEntry
 246  *     for errors and use errorAppendEntry() to account for
 247  *     persistent/pipeline connections.
 248  *
 249  \param clientConn  socket where page object is to be written
 250  \param err         This object is destroyed after use in this function.
 251  */
 252 void errorSend(const Comm::ConnectionPointer &conn, ErrorState *err);
 253
 254 /**
 255  \ingroup ErrorPageAPI
 256  *
 257  * This function generates a error page from the info contained
 258  * by err and then stores the text in the specified store
 259  * entry.
 260  * This function should only be called by "server
 261  * side routines" which need to communicate errors to the
 262  * client side.  It should also be called from client_side.c
 263  * because we now support persistent connections, and
 264  * cannot assume that we can immediately write to the socket
 265  * for an error.
 266  *
 267  \param entry   ??
 268  \param err     This object is destroyed after use in this function.
 269  */
 270 void errorAppendEntry(StoreEntry *entry, ErrorState *err);
 271
 272 /// allocates a new slot for the error page
 273 err_type errorReservePageId(const char *page_name, const SBuf &cfgLocation);
 274
 275 const char *errorPageName(int pageId); ///< error ID to string
 276
 277 /**
 278  \ingroup ErrorPageAPI
 279  *
 280  * loads text templates used for error pages and details;
 281  * supports translation of templates
 282  */
 283 class TemplateFile
 284 {
 285 public:
 286     TemplateFile(const char *name, const err_type code);
 287     virtual ~TemplateFile() {}
 288
 289     /// return true if the data loaded from disk without any problem
 290     bool loaded() const {return wasLoaded;}
 291
 292     /**
 293      * Load the page_name template from a file which  probably exist at:
 294      *  (a) admin specified custom directory (error_directory)
 295      *  (b) default language translation directory (error_default_language)
 296      *  (c) English sub-directory where errors should ALWAYS exist
 297      * If all of the above fail, setDefault() is called.
 298      */
 299     void loadDefault();
 300
 301     /**
 302      * Load an error template for a given HTTP request. This function examines the
 303      * Accept-Language header and select the first available template. If the default
 304      * template selected (eg because of a "Accept-Language: *"), or not available
 305      * template found this function return false.
 306      */
 307     bool loadFor(const HttpRequest *request);
 308
 309     /**
 310      * Load the file given by "path". It uses the "parse()" method.
 311      * On success return true and sets the "defined" member
 312      */
 313     bool loadFromFile(const char *path);
 314
 315     /// The language used for the template
 316     const char *language() {return errLanguage.termedBuf();}
 317
 318     SBuf filename; ///< where the template was loaded from
 319
 320     bool silent; ///< Whether to print error messages on cache.log file or not. It is user defined.
 321
 322 protected:
 323     /// post-process the loaded template
 324     virtual bool parse() { return true; }
 325
 326     /// recover from loadDefault() failure to load or parse() a template
 327     virtual void setDefault() {}
 328
 329     /**
 330      * Try to load the "page_name" template for a given language "lang"
 331      * from squid errors directory
 332      \return true on success false otherwise
 333      */
 334     bool tryLoadTemplate(const char *lang);
 335
 336     SBuf template_; ///< raw template contents
 337     bool wasLoaded; ///< True if the template data read from disk without any problem
 338     String errLanguage; ///< The error language of the template.
 339     String templateName; ///< The name of the template
 340     err_type templateCode; ///< The internal code for this template.
 341 };
 342
 343 /**
 344  * Parses the Accept-Language header value and return one language item on
 345  * each call.
 346  * Will ignore any whitespace, q-values, and detectably invalid language
 347  * codes in the header.
 348  *
 349  * \param hdr is the Accept-Language header value
 350  * \param lang a buffer to store parsed language code in
 351  * \param langlen the length of the lang buffer
 352  * \param pos is used to store the offset state of parsing. Must be "0" on first call.
 353  *            Will be altered to point at the start of next field-value.
 354  * \return true if something looking like a language token has been placed in lang, false otherwise
 355  */
 356 bool strHdrAcptLangGetItem(const String &hdr, char *lang, int langLen, size_t &pos);
 357
 358 #endif /* SQUID_ERRORPAGE_H */
 359