Add IPAddress class as a replacement for the IPAddressNumber typedef.

net/base/ip_address.cc

Index: net/base/ip_address.cc
diff --git a/net/base/ip_address.cc b/net/base/ip_address.cc
new file mode 100644
index 0000000000000000000000000000000000000000..9b76f2e34319f48fd0e4f80a9b843fc5e57eb59b
--- /dev/null
+++ b/net/base/ip_address.cc
@@ -0,0 +1,390 @@
+// Copyright (c) 2015 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_address.h"
+
+#include "base/logging.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/string_split.h"
+#include "base/strings/stringprintf.h"
+#include "base/sys_byteorder.h"
+#include "url/gurl.h"
+#include "url/url_canon_ip.h"
+
+namespace net {
+
+const unsigned char IPAddress::kIPv4MappedPrefix[] = {0, 0, 0, 0, 0,    0,
+                                                      0, 0, 0, 0, 0xFF, 0xFF};
+
+IPAddress::IPAddress() {}
+
+IPAddress::~IPAddress() {}
+
+IPAddress::IPAddress(std::vector<unsigned char>& ip_address)
+    : ip_address_(ip_address) {}
+
+// Don't compare IPv4 and IPv6 addresses (they have different range
+// reservations). Keep separate reservation arrays for each IP type, and
+// consolidate adjacent reserved ranges within a reservation array when
+// possible.
+// Sources for info:
+// www.iana.org/assignments/ipv4-address-space/ipv4-address-space.xhtml
+// www.iana.org/assignments/ipv6-address-space/ipv6-address-space.xhtml
+// They're formatted here with the prefix as the last element. For example:
+// 10.0.0.0/8 becomes 10,0,0,0,8 and fec0::/10 becomes 0xfe,0xc0,0,0,0...,10.
+bool IPAddress::IsIPAddressReserved() const {
+  static const unsigned char kReservedIPv4[][5] = {
+      {0, 0, 0, 0, 8},     {10, 0, 0, 0, 8},      {100, 64, 0, 0, 10},
+      {127, 0, 0, 0, 8},   {169, 254, 0, 0, 16},  {172, 16, 0, 0, 12},
+      {192, 0, 2, 0, 24},  {192, 88, 99, 0, 24},  {192, 168, 0, 0, 16},
+      {198, 18, 0, 0, 15}, {198, 51, 100, 0, 24}, {203, 0, 113, 0, 24},
+      {224, 0, 0, 0, 3}};
+  static const unsigned char kReservedIPv6[][17] = {
+      {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 8},
+      {0x40, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2},
+      {0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2},
+      {0xc0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3},
+      {0xe0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4},
+      {0xf0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5},
+      {0xf8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 6},
+      {0xfc, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 7},
+      {0xfe, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 9},
+      {0xfe, 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 10},
+      {0xfe, 0xc0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 10},
+  };
+  size_t array_size = 0;
+  const unsigned char* array = NULL;
+  switch (ip_address_.size()) {
+    case kIPv4AddressSize:
+      array_size = arraysize(kReservedIPv4);
+      array = kReservedIPv4[0];
+      break;
+    case kIPv6AddressSize:
+      array_size = arraysize(kReservedIPv6);
+      array = kReservedIPv6[0];
+      break;
+  }
+  if (!array)
+    return false;
+  size_t width = ip_address_.size() + 1;
+  for (size_t i = 0; i < array_size; ++i, array += width) {
+    if (IPAddressPrefixCheck(array, array[width - 1]))
+      return true;
+  }
+  return false;
+}
+
+std::string IPAddress::ToString() const {
+  std::string str;
+  url::StdStringCanonOutput output(&str);
+
+  if (IsIPv4()) {
+    url::AppendIPv4Address(&ip_address_.front(), &output);
+  } else if (IsIPv6()) {
+    url::AppendIPv6Address(&ip_address_.front(), &output);
+  } else {
+    size_t address_len = ip_address_.size();
+    CHECK(false) << "Invalid IP address with length: " << address_len;
+  }
+
+  output.Complete();
+  return str;
+}
+
+std::string IPAddress::ToStringWithPort(uint16_t port) const {
+  std::string address_str = ToString();
+
+  if (IsIPv6()) {
+    // Need to bracket IPv6 addresses since they contain colons.
+    return base::StringPrintf("[%s]:%d", address_str.c_str(), port);
+  }
+  return base::StringPrintf("%s:%d", address_str.c_str(), port);
+}
+
+std::string IPAddress::ToPackedString() const {
+  return std::string(reinterpret_cast<const char*>(&ip_address_.front()),
+                     ip_address_.size());
+}
+
+// Returns number of matching initial bits between the addresses and |other|.
+unsigned IPAddress::CommonPrefixLength(const IPAddress& other) const {
+  DCHECK_EQ(ip_address_.size(), other.ip_address_.size());
+  for (size_t i = 0; i < ip_address_.size(); ++i) {
+    unsigned diff = ip_address_[i] ^ other.ip_address_[i];
+    if (!diff)
+      continue;
+    for (unsigned j = 0; j < CHAR_BIT; ++j) {
+      if (diff & (1 << (CHAR_BIT - 1)))
+        return i * CHAR_BIT + j;
+      diff <<= 1;
+    }
+    NOTREACHED();
+  }
+  return ip_address_.size() * CHAR_BIT;
+}
+
+// Computes the number of leading 1-bits in |ip_address_|.
+unsigned IPAddress::MaskPrefixLength() const {
+  std::vector<unsigned char> all_ones_mask(ip_address_.size(), 0xFF);
+  IPAddress all_ones(all_ones_mask);
+  return all_ones.CommonPrefixLength(all_ones);
+}
+
+bool IPAddress::IsIPv4Mapped() const {
+  if (!IsIPv6())
+    return false;
+  return std::equal(ip_address_.begin(),
+                    ip_address_.begin() + arraysize(kIPv4MappedPrefix),
+                    kIPv4MappedPrefix);
+}
+
+AddressFamily IPAddress::GetAddressFamily() const {
+  switch (ip_address_.size()) {
+    case kIPv4AddressSize:
+      return ADDRESS_FAMILY_IPV4;
+    case kIPv6AddressSize:
+      return ADDRESS_FAMILY_IPV6;
+    default:
+      return ADDRESS_FAMILY_UNSPECIFIED;
+  }
+}
+
+bool IPAddress::MatchesPrefix(const IPAddress& ip_prefix,
+                              size_t prefix_length_in_bits) {
+  // Both the input IP address and the prefix IP address should be
+  // either IPv4 or IPv6.
+  DCHECK(IsIPv4() || IsIPv6());
+  DCHECK(ip_prefix.IsIPv4() || ip_prefix.IsIPv6());
+
+  DCHECK_LE(prefix_length_in_bits, ip_prefix.ip_address_.size() * 8);
+
+  // In case we have an IPv6 / IPv4 mismatch, convert the IPv4 addresses to
+  // IPv6 addresses in order to do the comparison.
+  if (ip_address_.size() != ip_prefix.ip_address_.size()) {
+    if (IsIPv4()) {
+      IPAddress temp = IPAddress::ConvertIPv4ToIPv6(*this);
+      return temp.MatchesPrefix(ip_prefix, prefix_length_in_bits);
+    }
+    IPAddress temp = IPAddress::ConvertIPv4ToIPv6(ip_prefix);
+    return MatchesPrefix(temp, 96 + prefix_length_in_bits);
+  }
+
+  return IPAddressPrefixCheck(&ip_prefix, prefix_length_in_bits);
+}
+
+bool IPAddress::ToSockAddrWithPort(struct sockaddr* address,
+                                   socklen_t* address_length,
+                                   int port) const {
+  DCHECK(address);
+  DCHECK(address_length);
+  switch (ip_address_.size()) {
+    case kIPv4AddressSize: {
+      socklen_t kSockaddrInSize = sizeof(struct sockaddr_in);
+      if (*address_length < kSockaddrInSize)
+        return false;
+      *address_length = kSockaddrInSize;
+      struct sockaddr_in* addr = reinterpret_cast<struct sockaddr_in*>(address);
+      memset(addr, 0, sizeof(struct sockaddr_in));
+      addr->sin_family = AF_INET;
+      addr->sin_port = base::HostToNet16(port);
+      memcpy(&addr->sin_addr, &ip_address_[0], kIPv4AddressSize);
+      break;
+    }
+    case kIPv6AddressSize: {
+      socklen_t kSockaddrInSize = sizeof(struct sockaddr_in6);
+      if (*address_length < kSockaddrInSize)
+        return false;
+      *address_length = kSockaddrInSize;
+      struct sockaddr_in6* addr6 =
+          reinterpret_cast<struct sockaddr_in6*>(address);
+      memset(addr6, 0, sizeof(struct sockaddr_in6));
+      addr6->sin6_family = AF_INET6;
+      addr6->sin6_port = base::HostToNet16(port);
+      memcpy(&addr6->sin6_addr, &ip_address_[0], kIPv6AddressSize);
+      break;
+    }
+    default:
+      return false;
+  }
+  return true;
+}
+
+// static
+bool IPAddress::FromURLHostname(const std::string& hostname,
+                                IPAddress* ip_address) {
+  // |hostname| is an already canoncalized hostname, conforming to RFC 3986.
+  // For an IP address, this is defined in Section 3.2.2 of RFC 3986, with
+  // the canonical form for IPv6 addresses defined in Section 4 of RFC 5952.
+  url::Component host_comp(0, hostname.size());
+
+  std::vector<unsigned char> ip;
+
+  // If it has a bracket, try parsing it as an IPv6 address.
+  if (hostname[0] == '[') {
+    ip.resize(16);  // 128 bits.
+    bool result =
+        url::IPv6AddressToNumber(hostname.data(), host_comp, &(ip)[0]);
+    ip_address->ip_address_ = ip;
+    return result;
+  }
+
+  // Otherwise, try IPv4.
+  ip.resize(4);  // 32 bits.
+  int num_components;
+  url::CanonHostInfo::Family family = url::IPv4AddressToNumber(
+      hostname.data(), host_comp, &(ip)[0], &num_components);
+  ip_address->ip_address_ = ip;
+  return family == url::CanonHostInfo::IPV4;
+}
+
+// static
+bool IPAddress::FromIPLiteral(const base::StringPiece& ip_literal,
+                              IPAddress* ip_address) {
+  std::vector<unsigned char> ip;
+
+  // |ip_literal| could be either a IPv4 or an IPv6 literal. If it contains
+  // a colon however, it must be an IPv6 address.
+  if (ip_literal.find(':') != base::StringPiece::npos) {
+    // GURL expects IPv6 hostnames to be surrounded with brackets.
+    std::string host_brackets = "[";
+    ip_literal.AppendToString(&host_brackets);
+    host_brackets.push_back(']');
+    url::Component host_comp(0, host_brackets.size());
+
+    // Try parsing the hostname as an IPv6 literal.
+    ip.resize(16);  // 128 bits.
+    bool result =
+        url::IPv6AddressToNumber(host_brackets.data(), host_comp, &(ip)[0]);
+    ip_address->ip_address_ = ip;
+    return result;
+  }
+
+  // Otherwise the string is an IPv4 address.
+  ip.resize(4);  // 32 bits.
+  url::Component host_comp(0, ip_literal.size());
+  int num_components;
+  url::CanonHostInfo::Family family = url::IPv4AddressToNumber(
+      ip_literal.data(), host_comp, &(ip)[0], &num_components);
+
+  ip_address->ip_address_ = ip;
+  return family == url::CanonHostInfo::IPV4;
+}
+
+// static
+bool IPAddress::FromCIDRBlock(const std::string& cidr_literal,
+                              IPAddress* ip_address,
+                              size_t* prefix_length_in_bits) {
+  // We expect CIDR notation to match one of these two templates:
+  //   <IPv4-literal> "/" <number of bits>
+  //   <IPv6-literal> "/" <number of bits>
+
+  std::vector<base::StringPiece> parts = base::SplitStringPiece(
+      cidr_literal, "/", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
+  if (parts.size() != 2)
+    return false;
+
+  // Parse the IP address.
+  if (!IPAddress::FromIPLiteral(parts[0], ip_address))
+    return false;
+
+  // Parse the prefix length.
+  int number_of_bits = -1;
+  if (!base::StringToInt(parts[1], &number_of_bits))
+    return false;
+
+  // Make sure the prefix length is in a valid range.
+  if (number_of_bits < 0 ||
+      number_of_bits > static_cast<int>(ip_address->ip_address_.size() * 8))
+    return false;
+
+  *prefix_length_in_bits = static_cast<size_t>(number_of_bits);
+  return true;
+}
+
+// static
+IPAddress IPAddress::FromLegacy(const IPAddressNumber& ip_address) {
+  std::vector<unsigned char> address_copy(ip_address);
+  IPAddress new_address(address_copy);
+  return new_address;
+}
+
+// static
+IPAddress IPAddress::ConvertIPv4ToIPv6(const IPAddress& ipv4_address) {
+  DCHECK(ipv4_address.IsIPv4());
+
+  // IPv4-mapped addresses are formed by:
+  // <80 bits of zeros>  + <16 bits of ones> + <32-bit IPv4 address>.
+  std::vector<unsigned char> ipv6_address;
+  ipv6_address.reserve(16);
+  ipv6_address.insert(ipv6_address.end(), kIPv4MappedPrefix,
+                      kIPv4MappedPrefix + arraysize(kIPv4MappedPrefix));
+  ipv6_address.insert(ipv6_address.end(), ipv4_address.ip_address_.begin(),
+                      ipv4_address.ip_address_.end());
+  return IPAddress(ipv6_address);
+}
+
+// static
+IPAddress IPAddress::ConvertIPv4MappedToIPv4(const IPAddress& address) {
+  DCHECK(address.IsIPv4Mapped());
+  std::vector<unsigned char> without_prefix(
+      address.ip_address_.begin() + arraysize(kIPv4MappedPrefix),
+      address.ip_address_.end());
+  IPAddress ip_address(without_prefix);
+  return ip_address;
+}
+
+bool IPAddress::operator==(const IPAddress& that) const {
+  return ip_address_ == that.ip_address_;
+}
+
+bool IPAddress::operator!=(const IPAddress& that) const {
+  return ip_address_ != that.ip_address_;
+}
+
+bool IPAddress::operator<(const IPAddress& that) const {
+  // Sort IPv4 before IPv6.
+  if (ip_address_.size() != that.ip_address_.size()) {
+    return ip_address_.size() < that.ip_address_.size();
+  }
+
+  return ip_address_ < that.ip_address_;
+}
+
+bool IPAddress::operator>(const IPAddress& that) const {
+  // Sort IPv4 after IPv6.
+  if (ip_address_.size() != that.ip_address_.size()) {
+    return ip_address_.size() > that.ip_address_.size();
+  }
+
+  return ip_address_ > that.ip_address_;
+}
+
+bool IPAddress::IPAddressPrefixCheck(const IPAddress* ip_prefix,
+                                     size_t prefix_length_in_bits) const {
+  return IPAddressPrefixCheck(&(ip_prefix->ip_address_)[0],
+                              prefix_length_in_bits);
+}
+
+bool IPAddress::IPAddressPrefixCheck(const unsigned char* ip_prefix,
+                                     size_t prefix_length_in_bits) const {
+  // Compare all the bytes that fall entirely within the prefix.
+  int num_entire_bytes_in_prefix = prefix_length_in_bits / 8;
+  for (int i = 0; i < num_entire_bytes_in_prefix; ++i) {
+    if (ip_address_[i] != ip_prefix[i])
+      return false;
+  }
+
+  // In case the prefix was not a multiple of 8, there will be 1 byte
+  // which is only partially masked.
+  int remaining_bits = prefix_length_in_bits % 8;
+  if (remaining_bits != 0) {
+    unsigned char mask = 0xFF << (8 - remaining_bits);
+    int i = num_entire_bytes_in_prefix;
+    if ((ip_address_[i] & mask) != (ip_prefix[i] & mask))
+      return false;
+  }
+  return true;
+}
+
+}  // namespace net