net/base/ip_pattern.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "net/base/ip_pattern.h"
   6
   7 #include <string>
   8
   9 #include "base/logging.h"
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/stl_util.h"
  12 #include "base/strings/string_number_conversions.h"
  13 #include "base/strings/string_split.h"
  14 #include "base/strings/string_tokenizer.h"
  15
  16 namespace net {
  17
  18 class IPPattern::ComponentPattern {
  19  public:
  20   ComponentPattern();
  21   void AppendRange(uint32_t min, uint32_t max);
  22   bool Match(uint32_t value) const;
  23
  24  private:
  25   struct Range {
  26    public:
  27     Range(uint32_t min, uint32_t max) : minimum(min), maximum(max) {}
  28     uint32_t minimum;
  29     uint32_t maximum;
  30   };
  31   typedef std::vector<Range> RangeVector;
  32
  33   RangeVector ranges_;
  34
  35   DISALLOW_COPY_AND_ASSIGN(ComponentPattern);
  36 };
  37
  38 IPPattern::ComponentPattern::ComponentPattern() {}
  39
  40 void IPPattern::ComponentPattern::AppendRange(uint32_t min, uint32_t max) {
  41   ranges_.push_back(Range(min, max));
  42 }
  43
  44 bool IPPattern::ComponentPattern::Match(uint32_t value) const {
  45   // Simple linear search should be fine, as we usually only have very few
  46   // distinct ranges to test.
  47   for (RangeVector::const_iterator range_it = ranges_.begin();
  48        range_it != ranges_.end(); ++range_it) {
  49     if (range_it->maximum >= value && range_it->minimum <= value)
  50       return true;
  51   }
  52   return false;
  53 }
  54
  55 IPPattern::IPPattern() : is_ipv4_(true) {}
  56
  57 IPPattern::~IPPattern() {
  58   STLDeleteElements(&component_patterns_);
  59 }
  60
  61 bool IPPattern::Match(const IPAddressNumber& address) const {
  62   if (ip_mask_.empty())
  63     return false;
  64   bool address_is_ipv4 = address.size() == kIPv4AddressSize;
  65   if (address_is_ipv4 != is_ipv4_)
  66     return false;
  67
  68   ComponentPatternList::const_iterator pattern_it(component_patterns_.begin());
  69   int fixed_value_index = 0;
  70   // IPv6 |address| vectors have 16 pieces, while our  |ip_mask_| has only
  71   // 8, so it is easier to count separately.
  72   int address_index = 0;
  73   for (size_t i = 0; i < ip_mask_.size(); ++i) {
  74     uint32_t value_to_test = address[address_index++];
  75     if (!is_ipv4_) {
  76       value_to_test = (value_to_test << 8) + address[address_index++];
  77     }
  78     if (ip_mask_[i]) {
  79       if (component_values_[fixed_value_index++] != value_to_test)
  80         return false;
  81       continue;
  82     }
  83     if (!(*pattern_it)->Match(value_to_test))
  84       return false;
  85     ++pattern_it;
  86   }
  87   return true;
  88 }
  89
  90 bool IPPattern::ParsePattern(const std::string& ip_pattern) {
  91   DCHECK(ip_mask_.empty());
  92   if (ip_pattern.find(':') != std::string::npos) {
  93     is_ipv4_ = false;
  94   }
  95
  96   std::vector<base::StringPiece> components =
  97       base::SplitStringPiece(ip_pattern, is_ipv4_ ? "." : ":",
  98                              base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
  99   if (components.size() != (is_ipv4_ ? 4u : 8u)) {
 100     DVLOG(1) << "Invalid component count: " << ip_pattern;
 101     return false;
 102   }
 103   for (base::StringPiece component : components) {
 104     if (component.empty()) {
 105       DVLOG(1) << "Empty component: " << ip_pattern;
 106       return false;
 107     }
 108     if (component == "*") {
 109       // Let standard code handle this below.
 110       component = is_ipv4_ ? "[0-255]" : "[0-FFFF]";
 111     } else if (component[0] != '[') {
 112       // This value will just have a specific integer to match.
 113       uint32_t value;
 114       if (!ValueTextToInt(component, &value))
 115         return false;
 116       ip_mask_.push_back(true);
 117       component_values_.push_back(value);
 118       continue;
 119     }
 120     if (component[component.size() - 1] != ']') {
 121       DVLOG(1) << "Missing close bracket: " << ip_pattern;
 122       return false;
 123     }
 124     // Now we know the size() is at least 2.
 125     if (component.size() == 2) {
 126       DVLOG(1) << "Empty bracket: " << ip_pattern;
 127       return false;
 128     }
 129     // We'll need a pattern to match this bracketed component.
 130     scoped_ptr<ComponentPattern> component_pattern(new ComponentPattern);
 131     // Trim leading and trailing bracket before calling for parsing.
 132     if (!ParseComponentPattern(component.substr(1, component.size() - 2),
 133                                component_pattern.get())) {
 134       return false;
 135     }
 136     ip_mask_.push_back(false);
 137     component_patterns_.push_back(component_pattern.release());
 138   }
 139   return true;
 140 }
 141
 142 bool IPPattern::ParseComponentPattern(const base::StringPiece& text,
 143                                       ComponentPattern* pattern) const {
 144   // We're given a comma separated set of ranges, some of which may be simple
 145   // constants.
 146   for (const std::string& range : base::SplitString(
 147            text, ",", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL)) {
 148     base::StringTokenizer range_pair(range, "-");
 149     uint32_t min = 0;
 150     range_pair.GetNext();
 151     if (!ValueTextToInt(range_pair.token_piece(), &min))
 152       return false;
 153     uint32_t max = min;  // Sometimes we have no distinct max.
 154     if (range_pair.GetNext()) {
 155       if (!ValueTextToInt(range_pair.token_piece(), &max))
 156         return false;
 157     }
 158     if (range_pair.GetNext()) {
 159       // Too many "-" in this range specifier.
 160       DVLOG(1) << "Too many hyphens in range: ";
 161       return false;
 162     }
 163     pattern->AppendRange(min, max);
 164   }
 165   return true;
 166 }
 167
 168 bool IPPattern::ValueTextToInt(const base::StringPiece& input,
 169                                uint32_t* output) const {
 170   bool ok = is_ipv4_ ? base::StringToUint(input, output) :
 171                        base::HexStringToUInt(input, output);
 172   if (!ok) {
 173     DVLOG(1) << "Could not convert value to number: " << input;
 174     return false;
 175   }
 176   if (is_ipv4_ && *output > 255u) {
 177     DVLOG(1) << "IPv4 component greater than 255";
 178     return false;
 179   }
 180   if (!is_ipv4_ && *output > 0xFFFFu) {
 181     DVLOG(1) << "IPv6 component greater than 0xFFFF";
 182     return false;
 183   }
 184   return ok;
 185 }
 186
 187 }  // namespace net