src/http/ContentLengthInterpreter.h

   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 #ifndef SQUID_SRC_HTTP_CONTENTLENGTH_INTERPRETER_H
  10 #define SQUID_SRC_HTTP_CONTENTLENGTH_INTERPRETER_H
  11
  12 #include "http/StatusCode.h"
  13
  14 class String;
  15
  16 namespace Http
  17 {
  18
  19 /// Finds the intended Content-Length value while parsing message-header fields.
  20 /// Deals with complications such as value lists and/or repeated fields.
  21 class ContentLengthInterpreter
  22 {
  23 public:
  24     ContentLengthInterpreter();
  25
  26     /// updates history based on the given message-header field
  27     /// \return true iff the field should be added/remembered for future use
  28     bool checkField(const String &field);
  29
  30     /// prohibits Content-Length in 1xx and 204 responses
  31     void applyStatusCodeRules(const StatusCode code) {
  32         if (!prohibitedAndIgnored_ && ProhibitsContentLength(code))
  33             prohibitedAndIgnored_ = (code == scNoContent) ? "prohibited and ignored in the 204 response" :
  34                                     "prohibited and ignored the 1xx response";
  35     }
  36
  37     // TODO: implement
  38     /// prohibits Content-Length in GET/HEAD requests
  39     // void applyRequestMethodRules(const Http::MethodType method);
  40
  41     /// prohibits Content-Length in trailer
  42     void applyTrailerRules() {
  43         if (!prohibitedAndIgnored_)
  44             prohibitedAndIgnored_ = "prohibited in trailers";
  45     }
  46
  47     const char *prohibitedAndIgnored() const { return prohibitedAndIgnored_; }
  48
  49     /// intended Content-Length value if sawGood is set and sawBad is not set
  50     /// meaningless otherwise
  51     int64_t value;
  52
  53     /* for debugging (declared here to minimize padding) */
  54     const char *headerWideProblem; ///< worst header-wide problem found (or nil)
  55     const int debugLevel; ///< debugging level for certain warnings
  56
  57     /// whether a malformed Content-Length value was present
  58     bool sawBad;
  59
  60     /// whether all remembered fields should be removed
  61     /// removed fields ought to be replaced with the intended value (if known)
  62     /// irrelevant if sawBad is set
  63     bool needsSanitizing;
  64
  65     /// whether a valid field value was present, possibly among problematic ones
  66     /// irrelevant if sawBad is set
  67     bool sawGood;
  68
  69 protected:
  70     const char *findDigits(const char *prefix, const char *valueEnd) const;
  71     bool goodSuffix(const char *suffix, const char * const end) const;
  72     bool checkValue(const char *start, const int size);
  73     bool checkList(const String &list);
  74
  75 private:
  76     /// whether and why Content-Length is prohibited
  77     const char *prohibitedAndIgnored_;
  78 };
  79
  80 } // namespace Http
  81
  82 #endif /* SQUID_SRC_HTTP_CONTENTLENGTH_INTERPRETER_H */
  83