src/errorpage.h

   1 /*
   2  * Copyright (C) 1996-2015 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/StatusCode.h"
  19 #include "ip/Address.h"
  20 #include "SquidString.h"
  21 /* auth/UserRequest.h is empty unless USE_AUTH is defined */
  22 #include "auth/UserRequest.h"
  23 #if USE_OPENSSL
  24 #include "ssl/ErrorDetail.h"
  25 #endif
  26
  27 /// error page callback
  28 typedef void ERCB(int fd, void *, size_t);
  29
  30 /**
  31  \defgroup ErrorPageAPI Error Pages API
  32  \ingroup Components
  33  \section ErrorPageStringCodes Error Page % codes for text insertion.
  34  *
  35  \verbatim
  36    a - User identity                            x
  37    B - URL with FTP %2f hack                    x
  38    c - Squid error code                         x
  39    d - seconds elapsed since request received   x
  40    D - Error details                            x
  41    e - errno                                    x
  42    E - strerror()                               x
  43    f - FTP request line                         x
  44    F - FTP reply line                           x
  45    g - FTP server message                       x
  46    h - cache hostname                           x
  47    H - server host name                         x
  48    i - client IP address                        x
  49    I - server IP address                        x
  50    l - HREF link for CSS stylesheet inclusion   x
  51    L - HREF link for more info/contact          x
  52    M - Request Method                           x
  53    m - Error message returned by auth helper    x
  54    o - Message returned external acl helper     x
  55    p - URL port #                               x
  56    P - Protocol                                 x
  57    R - Full HTTP Request                        x
  58    S - squid signature from ERR_SIGNATURE       x
  59    s - caching proxy software with version      x
  60    t - local time                               x
  61    T - UTC                                      x
  62    U - URL without password                     x
  63    u - URL with password                        x
  64    w - cachemgr email address                   x
  65    W - error data (to be included in the mailto links)
  66    x - error name                               x
  67    z - dns server error message                 x
  68    Z - Preformatted error message               x
  69  \endverbatim
  70  */
  71
  72 class HttpReply;
  73 class HttpRequest;
  74 class MemBuf;
  75
  76 /// \ingroup ErrorPageAPI
  77 class ErrorState
  78 {
  79     CBDATA_CLASS(ErrorState);
  80
  81 public:
  82     ErrorState(err_type type, Http::StatusCode, HttpRequest * request);
  83     ErrorState(); // not implemented.
  84     ~ErrorState();
  85
  86     /// Creates a general request forwarding error with the right http_status.
  87     static ErrorState *NewForwarding(err_type type, HttpRequest *request);
  88
  89     /**
  90      * Allocates and initializes an error response
  91      */
  92     HttpReply *BuildHttpReply(void);
  93
  94     /// set error type-specific detail code
  95     void detailError(int dCode) {detailCode = dCode;}
  96
  97 private:
  98     /**
  99      * Locates error page template to be used for this error
 100      * and constructs the HTML page content from it.
 101      */
 102     MemBuf *BuildContent(void);
 103
 104     /**
 105      * Convert the given template string into textual output
 106      *
 107      * \param text            The string to be converted
 108      * \param allowRecursion  Whether to convert codes which output may contain codes
 109      */
 110     MemBuf *ConvertText(const char *text, bool allowRecursion);
 111
 112     /**
 113      * Generates the Location: header value for a deny_info error page
 114      * to be used for this error.
 115      */
 116     void DenyInfoLocation(const char *name, HttpRequest *request, MemBuf &result);
 117
 118     /**
 119      * Map the Error page and deny_info template % codes into textual output.
 120      *
 121      * Several of the codes produce blocks of non-URL compatible results.
 122      * When processing the deny_info location URL they will be skipped.
 123      *
 124      * \param token                    The token following % which need to be converted
 125      * \param building_deny_info_url   Perform special deny_info actions, such as URL-encoding and token skipping.
 126      * \ allowRecursion   True if the codes which do recursions should converted
 127      */
 128     const char *Convert(char token, bool building_deny_info_url, bool allowRecursion);
 129
 130     /**
 131      * CacheManager / Debug dump of the ErrorState object.
 132      * Writes output into the given MemBuf.
 133      \retval 0 successful completion.
 134      */
 135     int Dump(MemBuf * mb);
 136
 137 public:
 138     err_type type;
 139     int page_id;
 140     char *err_language;
 141     Http::StatusCode httpStatus;
 142 #if USE_AUTH
 143     Auth::UserRequest::Pointer auth_user_request;
 144 #endif
 145     HttpRequest *request;
 146     char *url;
 147     int xerrno;
 148     unsigned short port;
 149     String dnsError; ///< DNS lookup error message
 150     time_t ttl;
 151
 152     Ip::Address src_addr;
 153     char *redirect_url;
 154     ERCB *callback;
 155     void *callback_data;
 156
 157     struct {
 158         wordlist *server_msg;
 159         char *request;
 160         char *reply;
 161         char *cwd_msg;
 162         MemBuf *listing;
 163     } ftp;
 164
 165     char *request_hdrs;
 166     char *err_msg; /* Preformatted error message from the cache */
 167
 168 #if USE_OPENSSL
 169     Ssl::ErrorDetail *detail;
 170 #endif
 171     /// type-specific detail about the transaction error;
 172     /// overwrites xerrno; overwritten by detail, if any.
 173     int detailCode;
 174 };
 175
 176 /**
 177  \ingroup ErrorPageAPI
 178  *
 179  * This function finds the error messages formats, and stores
 180  * them in error_text[]
 181  *
 182  \par Global effects:
 183  *            error_text[] - is modified
 184  */
 185 void errorInitialize(void);
 186
 187 /// \ingroup ErrorPageAPI
 188 void errorClean(void);
 189
 190 /**
 191  * \ingroup ErrorPageAPI
 192  *
 193  * This function generates a error page from the info contained
 194  * by err and then sends it to the client.
 195  * The callback function errorSendComplete() is called after
 196  * the page has been written to the client (clientConn).
 197  * errorSendComplete() deallocates err.  We need to add
 198  * err to the cbdata because comm_write() requires it
 199  * for all callback data pointers.
 200  *
 201  \note normally errorSend() should only be called from
 202  *     routines in ssl.c and pass.c, where we don't have any
 203  *     StoreEntry's.  In client_side.c we must allocate a StoreEntry
 204  *     for errors and use errorAppendEntry() to account for
 205  *     persistent/pipeline connections.
 206  *
 207  \param clientConn  socket where page object is to be written
 208  \param err         This object is destroyed after use in this function.
 209  */
 210 void errorSend(const Comm::ConnectionPointer &conn, ErrorState *err);
 211
 212 /**
 213  \ingroup ErrorPageAPI
 214  *
 215  * This function generates a error page from the info contained
 216  * by err and then stores the text in the specified store
 217  * entry.
 218  * This function should only be called by "server
 219  * side routines" which need to communicate errors to the
 220  * client side.  It should also be called from client_side.c
 221  * because we now support persistent connections, and
 222  * cannot assume that we can immediately write to the socket
 223  * for an error.
 224  *
 225  \param entry   ??
 226  \param err     This object is destroyed after use in this function.
 227  */
 228 void errorAppendEntry(StoreEntry *entry, ErrorState *err);
 229
 230 /// \ingroup ErrorPageAPI
 231 err_type errorReservePageId(const char *page_name);
 232
 233 const char *errorPageName(int pageId); ///< error ID to string
 234
 235 /**
 236  \ingroup ErrorPageAPI
 237  *
 238  * loads text templates used for error pages and details;
 239  * supports translation of templates
 240  */
 241 class TemplateFile
 242 {
 243 public:
 244     TemplateFile(const char *name, const err_type code);
 245     virtual ~TemplateFile() {}
 246
 247     /// return true if the data loaded from disk without any problem
 248     bool loaded() const {return wasLoaded;}
 249
 250     /**
 251      * Load the page_name template from a file which  probably exist at:
 252      *  (a) admin specified custom directory (error_directory)
 253      *  (b) default language translation directory (error_default_language)
 254      *  (c) English sub-directory where errors should ALWAYS exist
 255      */
 256     bool loadDefault();
 257
 258     /**
 259      * Load an error template for a given HTTP request. This function examines the
 260      * Accept-Language header and select the first available template. If the default
 261      * template selected (eg because of a "Accept-Language: *"), or not available
 262      * template found this function return false.
 263      */
 264     bool loadFor(const HttpRequest *request);
 265
 266     /**
 267      * Load the file given by "path". It uses the "parse()" method.
 268      * On success return true and sets the "defined" member
 269      */
 270     bool loadFromFile(const char *path);
 271
 272     /// The language used for the template
 273     const char *language() {return errLanguage.termedBuf();}
 274
 275     bool silent; ///< Whether to print error messages on cache.log file or not. It is user defined.
 276
 277 protected:
 278     /// Used to parse (if parsing required) the template data .
 279     virtual bool parse(const char *buf, int len, bool eof) = 0;
 280
 281     /**
 282      * Try to load the "page_name" template for a given language "lang"
 283      * from squid errors directory
 284      \return true on success false otherwise
 285      */
 286     bool tryLoadTemplate(const char *lang);
 287
 288     bool wasLoaded; ///< True if the template data read from disk without any problem
 289     String errLanguage; ///< The error language of the template.
 290     String templateName; ///< The name of the template
 291     err_type templateCode; ///< The internal code for this template.
 292 };
 293
 294 /**
 295  * Parses the Accept-Language header value and return one language item on
 296  * each call.
 297  * Will ignore any whitespace, q-values, and detectably invalid language
 298  * codes in the header.
 299  *
 300  * \param hdr is the Accept-Language header value
 301  * \param lang a buffer to store parsed language code in
 302  * \param langlen the length of the lang buffer
 303  * \param pos is used to store the offset state of parsing. Must be "0" on first call.
 304  *            Will be altered to point at the start of next field-value.
 305  * \return true if something looking like a language token has been placed in lang, false otherwise
 306  */
 307 bool strHdrAcptLangGetItem(const String &hdr, char *lang, int langLen, size_t &pos);
 308
 309 #endif /* SQUID_ERRORPAGE_H */
 310