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// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "net/base/ip_pattern.h"
#include <memory>
#include <string>
#include "base/logging.h"
#include "base/macros.h"
#include "base/stl_util.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_split.h"
#include "base/strings/string_tokenizer.h"
#include "net/base/ip_address.h"
namespace net {
class IPPattern::ComponentPattern {
public:
ComponentPattern();
void AppendRange(uint32_t min, uint32_t max);
bool Match(uint32_t value) const;
private:
struct Range {
public:
Range(uint32_t min, uint32_t max) : minimum(min), maximum(max) {}
uint32_t minimum;
uint32_t maximum;
};
typedef std::vector<Range> RangeVector;
RangeVector ranges_;
DISALLOW_COPY_AND_ASSIGN(ComponentPattern);
};
IPPattern::ComponentPattern::ComponentPattern() = default;
void IPPattern::ComponentPattern::AppendRange(uint32_t min, uint32_t max) {
ranges_.push_back(Range(min, max));
}
bool IPPattern::ComponentPattern::Match(uint32_t value) const {
// Simple linear search should be fine, as we usually only have very few
// distinct ranges to test.
for (auto range_it = ranges_.begin(); range_it != ranges_.end(); ++range_it) {
if (range_it->maximum >= value && range_it->minimum <= value)
return true;
}
return false;
}
IPPattern::IPPattern() : is_ipv4_(true) {}
IPPattern::~IPPattern() = default;
bool IPPattern::Match(const IPAddress& address) const {
if (ip_mask_.empty())
return false;
if (address.IsIPv4() != is_ipv4_)
return false;
auto pattern_it(component_patterns_.begin());
int fixed_value_index = 0;
// IPv6 |address| vectors have 16 pieces, while our |ip_mask_| has only
// 8, so it is easier to count separately.
int address_index = 0;
for (size_t i = 0; i < ip_mask_.size(); ++i) {
uint32_t value_to_test = address.bytes()[address_index++];
if (!is_ipv4_) {
value_to_test = (value_to_test << 8) + address.bytes()[address_index++];
}
if (ip_mask_[i]) {
if (component_values_[fixed_value_index++] != value_to_test)
return false;
continue;
}
if (!(*pattern_it)->Match(value_to_test))
return false;
++pattern_it;
}
return true;
}
bool IPPattern::ParsePattern(const std::string& ip_pattern) {
DCHECK(ip_mask_.empty());
if (ip_pattern.find(':') != std::string::npos) {
is_ipv4_ = false;
}
std::vector<base::StringPiece> components =
base::SplitStringPiece(ip_pattern, is_ipv4_ ? "." : ":",
base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
if (components.size() != (is_ipv4_ ? 4u : 8u)) {
DVLOG(1) << "Invalid component count: " << ip_pattern;
return false;
}
for (base::StringPiece component : components) {
if (component.empty()) {
DVLOG(1) << "Empty component: " << ip_pattern;
return false;
}
if (component == "*") {
// Let standard code handle this below.
component = is_ipv4_ ? "[0-255]" : "[0-FFFF]";
} else if (component[0] != '[') {
// This value will just have a specific integer to match.
uint32_t value;
if (!ValueTextToInt(component, &value))
return false;
ip_mask_.push_back(true);
component_values_.push_back(value);
continue;
}
if (component.back() != ']') {
DVLOG(1) << "Missing close bracket: " << ip_pattern;
return false;
}
// Now we know the size() is at least 2.
if (component.size() == 2) {
DVLOG(1) << "Empty bracket: " << ip_pattern;
return false;
}
// We'll need a pattern to match this bracketed component.
std::unique_ptr<ComponentPattern> component_pattern(new ComponentPattern);
// Trim leading and trailing bracket before calling for parsing.
if (!ParseComponentPattern(component.substr(1, component.size() - 2),
component_pattern.get())) {
return false;
}
ip_mask_.push_back(false);
component_patterns_.push_back(std::move(component_pattern));
}
return true;
}
bool IPPattern::ParseComponentPattern(const base::StringPiece& text,
ComponentPattern* pattern) const {
// We're given a comma separated set of ranges, some of which may be simple
// constants.
for (const std::string& range : base::SplitString(
text, ",", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL)) {
base::StringTokenizer range_pair(range, "-");
uint32_t min = 0;
range_pair.GetNext();
if (!ValueTextToInt(range_pair.token_piece(), &min))
return false;
uint32_t max = min; // Sometimes we have no distinct max.
if (range_pair.GetNext()) {
if (!ValueTextToInt(range_pair.token_piece(), &max))
return false;
}
if (range_pair.GetNext()) {
// Too many "-" in this range specifier.
DVLOG(1) << "Too many hyphens in range: ";
return false;
}
pattern->AppendRange(min, max);
}
return true;
}
bool IPPattern::ValueTextToInt(const base::StringPiece& input,
uint32_t* output) const {
bool ok = is_ipv4_ ? base::StringToUint(input, output) :
base::HexStringToUInt(input, output);
if (!ok) {
DVLOG(1) << "Could not convert value to number: " << input;
return false;
}
if (is_ipv4_ && *output > 255u) {
DVLOG(1) << "IPv4 component greater than 255";
return false;
}
if (!is_ipv4_ && *output > 0xFFFFu) {
DVLOG(1) << "IPv6 component greater than 0xFFFF";
return false;
}
return ok;
}
} // namespace net