Move googleurl into the Chrome repo.

url/url_canon_ip.cc

+// Copyright 2009, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "googleurl/src/url_canon_ip.h"
+
+#include <stdlib.h>
+
+#include "base/basictypes.h"
+#include "base/logging.h"
+#include "googleurl/src/url_canon_internal.h"
+
+namespace url_canon {
+
+namespace {
+
+// Converts one of the character types that represent a numerical base to the
+// corresponding base.
+int BaseForType(SharedCharTypes type) {
+  switch (type) {
+    case CHAR_HEX:
+      return 16;
+    case CHAR_DEC:
+      return 10;
+    case CHAR_OCT:
+      return 8;
+    default:
+      return 0;
+  }
+}
+
+template<typename CHAR, typename UCHAR>
+bool DoFindIPv4Components(const CHAR* spec,
+                          const url_parse::Component& host,
+                          url_parse::Component components[4]) {
+  if (!host.is_nonempty())
+    return false;
+
+  int cur_component = 0;  // Index of the component we're working on.
+  int cur_component_begin = host.begin;  // Start of the current component.
+  int end = host.end();
+  for (int i = host.begin; /* nothing */; i++) {
+    if (i >= end || spec[i] == '.') {
+      // Found the end of the current component.
+      int component_len = i - cur_component_begin;
+      components[cur_component] =
+          url_parse::Component(cur_component_begin, component_len);
+
+      // The next component starts after the dot.
+      cur_component_begin = i + 1;
+      cur_component++;
+
+      // Don't allow empty components (two dots in a row), except we may
+      // allow an empty component at the end (this would indicate that the
+      // input ends in a dot). We also want to error if the component is
+      // empty and it's the only component (cur_component == 1).
+      if (component_len == 0 && (i < end || cur_component == 1))
+        return false;
+
+      if (i >= end)
+        break;  // End of the input.
+
+      if (cur_component == 4) {
+        // Anything else after the 4th component is an error unless it is a
+        // dot that would otherwise be treated as the end of input.
+        if (spec[i] == '.' && i + 1 == end)
+          break;
+        return false;
+      }
+    } else if (static_cast<UCHAR>(spec[i]) >= 0x80 ||
+               !IsIPv4Char(static_cast<unsigned char>(spec[i]))) {
+      // Invalid character for an IPv4 address.
+      return false;
+    }
+  }
+
+  // Fill in any unused components.
+  while (cur_component < 4)
+    components[cur_component++] = url_parse::Component();
+  return true;
+}
+
+// Converts an IPv4 component to a 32-bit number, while checking for overflow.
+//
+// Possible return values:
+// - IPV4    - The number was valid, and did not overflow.
+// - BROKEN  - The input was numeric, but too large for a 32-bit field.
+// - NEUTRAL - Input was not numeric.
+//
+// The input is assumed to be ASCII. FindIPv4Components should have stripped
+// out any input that is greater than 7 bits. The components are assumed
+// to be non-empty.
+template<typename CHAR>
+CanonHostInfo::Family IPv4ComponentToNumber(
+    const CHAR* spec,
+    const url_parse::Component& component,
+    uint32* number) {
+  // Figure out the base
+  SharedCharTypes base;
+  int base_prefix_len = 0;  // Size of the prefix for this base.
+  if (spec[component.begin] == '0') {
+    // Either hex or dec, or a standalone zero.
+    if (component.len == 1) {
+      base = CHAR_DEC;
+    } else if (spec[component.begin + 1] == 'X' ||
+               spec[component.begin + 1] == 'x') {
+      base = CHAR_HEX;
+      base_prefix_len = 2;
+    } else {
+      base = CHAR_OCT;
+      base_prefix_len = 1;
+    }
+  } else {
+    base = CHAR_DEC;
+  }
+
+  // Extend the prefix to consume all leading zeros.
+  while (base_prefix_len < component.len &&
+         spec[component.begin + base_prefix_len] == '0')
+    base_prefix_len++;
+
+  // Put the component, minus any base prefix, into a NULL-terminated buffer so
+  // we can call the standard library.  Because leading zeros have already been
+  // discarded, filling the entire buffer is guaranteed to trigger the 32-bit
+  // overflow check.
+  const int kMaxComponentLen = 16;
+  char buf[kMaxComponentLen + 1];  // digits + '\0'
+  int dest_i = 0;
+  for (int i = component.begin + base_prefix_len; i < component.end(); i++) {
+    // We know the input is 7-bit, so convert to narrow (if this is the wide
+    // version of the template) by casting.
+    char input = static_cast<char>(spec[i]);
+
+    // Validate that this character is OK for the given base.
+    if (!IsCharOfType(input, base))
+      return CanonHostInfo::NEUTRAL;
+
+    // Fill the buffer, if there's space remaining.  This check allows us to
+    // verify that all characters are numeric, even those that don't fit.
+    if (dest_i < kMaxComponentLen)
+      buf[dest_i++] = input;
+  }
+
+  buf[dest_i] = '\0';
+
+  // Use the 64-bit strtoi so we get a big number (no hex, decimal, or octal
+  // number can overflow a 64-bit number in <= 16 characters).
+  uint64 num = _strtoui64(buf, NULL, BaseForType(base));
+
+  // Check for 32-bit overflow.
+  if (num > kuint32max)
+    return CanonHostInfo::BROKEN;
+
+  // No overflow.  Success!
+  *number = static_cast<uint32>(num);
+  return CanonHostInfo::IPV4;
+}
+
+// See declaration of IPv4AddressToNumber for documentation.
+template<typename CHAR>
+CanonHostInfo::Family DoIPv4AddressToNumber(const CHAR* spec,
+                                            const url_parse::Component& host,
+                                            unsigned char address[4],
+                                            int* num_ipv4_components) {
+  // The identified components. Not all may exist.
+  url_parse::Component components[4];
+  if (!FindIPv4Components(spec, host, components))
+    return CanonHostInfo::NEUTRAL;
+
+  // Convert existing components to digits. Values up to
+  // |existing_components| will be valid.
+  uint32 component_values[4];
+  int existing_components = 0;
+
+  // Set to true if one or more components are BROKEN.  BROKEN is only
+  // returned if all components are IPV4 or BROKEN, so, for example,
+  // 12345678912345.de returns NEUTRAL rather than broken.
+  bool broken = false;
+  for (int i = 0; i < 4; i++) {
+    if (components[i].len <= 0)
+      continue;
+    CanonHostInfo::Family family = IPv4ComponentToNumber(
+        spec, components[i], &component_values[existing_components]);
+
+    if (family == CanonHostInfo::BROKEN) {
+      broken = true;
+    } else if (family != CanonHostInfo::IPV4) {
+      // Stop if we hit a non-BROKEN invalid non-empty component.
+      return family;
+    }
+
+    existing_components++;
+  }
+
+  if (broken)
+    return CanonHostInfo::BROKEN;
+
+  // Use that sequence of numbers to fill out the 4-component IP address.
+
+  // First, process all components but the last, while making sure each fits
+  // within an 8-bit field.
+  for (int i = 0; i < existing_components - 1; i++) {
+    if (component_values[i] > kuint8max)
+      return CanonHostInfo::BROKEN;
+    address[i] = static_cast<unsigned char>(component_values[i]);
+  }
+
+  // Next, consume the last component to fill in the remaining bytes.
+  uint32 last_value = component_values[existing_components - 1];
+  for (int i = 3; i >= existing_components - 1; i--) {
+    address[i] = static_cast<unsigned char>(last_value);
+    last_value >>= 8;
+  }
+
+  // If the last component has residual bits, report overflow.
+  if (last_value != 0)
+    return CanonHostInfo::BROKEN;
+
+  // Tell the caller how many components we saw.
+  *num_ipv4_components = existing_components;
+
+  // Success!
+  return CanonHostInfo::IPV4;
+}
+
+// Return true if we've made a final IPV4/BROKEN decision, false if the result
+// is NEUTRAL, and we could use a second opinion.
+template<typename CHAR, typename UCHAR>
+bool DoCanonicalizeIPv4Address(const CHAR* spec,
+                               const url_parse::Component& host,
+                               CanonOutput* output,
+                               CanonHostInfo* host_info) {
+  host_info->family = IPv4AddressToNumber(
+      spec, host, host_info->address, &host_info->num_ipv4_components);
+
+  switch (host_info->family) {
+    case CanonHostInfo::IPV4:
+      // Definitely an IPv4 address.
+      host_info->out_host.begin = output->length();
+      AppendIPv4Address(host_info->address, output);
+      host_info->out_host.len = output->length() - host_info->out_host.begin;
+      return true;
+    case CanonHostInfo::BROKEN:
+      // Definitely broken.
+      return true;
+    default:
+      // Could be IPv6 or a hostname.
+      return false;
+  }
+}
+
+// Helper class that describes the main components of an IPv6 input string.
+// See the following examples to understand how it breaks up an input string:
+//
+// [Example 1]: input = "[::aa:bb]"
+//  ==> num_hex_components = 2
+//  ==> hex_components[0] = Component(3,2) "aa"
+//  ==> hex_components[1] = Component(6,2) "bb"
+//  ==> index_of_contraction = 0
+//  ==> ipv4_component = Component(0, -1)
+//
+// [Example 2]: input = "[1:2::3:4:5]"
+//  ==> num_hex_components = 5
+//  ==> hex_components[0] = Component(1,1) "1"
+//  ==> hex_components[1] = Component(3,1) "2"
+//  ==> hex_components[2] = Component(6,1) "3"
+//  ==> hex_components[3] = Component(8,1) "4"
+//  ==> hex_components[4] = Component(10,1) "5"
+//  ==> index_of_contraction = 2
+//  ==> ipv4_component = Component(0, -1)
+//
+// [Example 3]: input = "[::ffff:192.168.0.1]"
+//  ==> num_hex_components = 1
+//  ==> hex_components[0] = Component(3,4) "ffff"
+//  ==> index_of_contraction = 0
+//  ==> ipv4_component = Component(8, 11) "192.168.0.1"
+//
+// [Example 4]: input = "[1::]"
+//  ==> num_hex_components = 1
+//  ==> hex_components[0] = Component(1,1) "1"
+//  ==> index_of_contraction = 1
+//  ==> ipv4_component = Component(0, -1)
+//
+// [Example 5]: input = "[::192.168.0.1]"
+//  ==> num_hex_components = 0
+//  ==> index_of_contraction = 0
+//  ==> ipv4_component = Component(8, 11) "192.168.0.1"
+//
+struct IPv6Parsed {
+  // Zero-out the parse information.
+  void reset() {
+    num_hex_components = 0;
+    index_of_contraction = -1;
+    ipv4_component.reset();
+  }
+
+  // There can be up to 8 hex components (colon separated) in the literal.
+  url_parse::Component hex_components[8];
+
+  // The count of hex components present. Ranges from [0,8].
+  int num_hex_components;
+
+  // The index of the hex component that the "::" contraction precedes, or
+  // -1 if there is no contraction.
+  int index_of_contraction;
+
+  // The range of characters which are an IPv4 literal.
+  url_parse::Component ipv4_component;
+};
+
+// Parse the IPv6 input string. If parsing succeeded returns true and fills
+// |parsed| with the information. If parsing failed (because the input is
+// invalid) returns false.
+template<typename CHAR, typename UCHAR>
+bool DoParseIPv6(const CHAR* spec,
+                 const url_parse::Component& host,
+                 IPv6Parsed* parsed) {
+  // Zero-out the info.
+  parsed->reset();
+
+  if (!host.is_nonempty())
+    return false;
+
+  // The index for start and end of address range (no brackets).
+  int begin = host.begin;
+  int end = host.end();
+
+  int cur_component_begin = begin;  // Start of the current component.
+
+  // Scan through the input, searching for hex components, "::" contractions,
+  // and IPv4 components.
+  for (int i = begin; /* i <= end */; i++) {
+    bool is_colon = spec[i] == ':';
+    bool is_contraction = is_colon && i < end - 1 && spec[i + 1] == ':';
+
+    // We reached the end of the current component if we encounter a colon
+    // (separator between hex components, or start of a contraction), or end of
+    // input.
+    if (is_colon || i == end) {
+      int component_len = i - cur_component_begin;
+
+      // A component should not have more than 4 hex digits.
+      if (component_len > 4)
+        return false;
+
+      // Don't allow empty components.
+      if (component_len == 0) {
+        // The exception is when contractions appear at beginning of the
+        // input or at the end of the input.
+        if (!((is_contraction && i == begin) || (i == end &&
+            parsed->index_of_contraction == parsed->num_hex_components)))
+          return false;
+      }
+
+      // Add the hex component we just found to running list.
+      if (component_len > 0) {
+        // Can't have more than 8 components!
+        if (parsed->num_hex_components >= 8)
+          return false;
+
+        parsed->hex_components[parsed->num_hex_components++] =
+            url_parse::Component(cur_component_begin, component_len);
+      }
+    }
+
+    if (i == end)
+      break;  // Reached the end of the input, DONE.
+
+    // We found a "::" contraction.
+    if (is_contraction) {
+      // There can be at most one contraction in the literal.
+      if (parsed->index_of_contraction != -1)
+        return false;
+      parsed->index_of_contraction = parsed->num_hex_components;
+      ++i;  // Consume the colon we peeked.
+    }
+
+    if (is_colon) {
+      // Colons are separators between components, keep track of where the
+      // current component started (after this colon).
+      cur_component_begin = i + 1;
+    } else {
+      if (static_cast<UCHAR>(spec[i]) >= 0x80)
+        return false;  // Not ASCII.
+
+      if (!IsHexChar(static_cast<unsigned char>(spec[i]))) {
+        // Regular components are hex numbers. It is also possible for
+        // a component to be an IPv4 address in dotted form.
+        if (IsIPv4Char(static_cast<unsigned char>(spec[i]))) {
+          // Since IPv4 address can only appear at the end, assume the rest
+          // of the string is an IPv4 address. (We will parse this separately
+          // later).
+          parsed->ipv4_component = url_parse::Component(
+              cur_component_begin, end - cur_component_begin);
+          break;
+        } else {
+          // The character was neither a hex digit, nor an IPv4 character.
+          return false;
+        }
+      }
+    }
+  }
+
+  return true;
+}
+
+// Verifies the parsed IPv6 information, checking that the various components
+// add up to the right number of bits (hex components are 16 bits, while
+// embedded IPv4 formats are 32 bits, and contractions are placeholdes for
+// 16 or more bits). Returns true if sizes match up, false otherwise. On
+// success writes the length of the contraction (if any) to
+// |out_num_bytes_of_contraction|.
+bool CheckIPv6ComponentsSize(const IPv6Parsed& parsed,
+                             int* out_num_bytes_of_contraction) {
+  // Each group of four hex digits contributes 16 bits.
+  int num_bytes_without_contraction = parsed.num_hex_components * 2;
+
+  // If an IPv4 address was embedded at the end, it contributes 32 bits.
+  if (parsed.ipv4_component.is_valid())
+    num_bytes_without_contraction += 4;
+
+  // If there was a "::" contraction, its size is going to be:
+  // MAX([16bits], [128bits] - num_bytes_without_contraction).
+  int num_bytes_of_contraction = 0;
+  if (parsed.index_of_contraction != -1) {
+    num_bytes_of_contraction = 16 - num_bytes_without_contraction;
+    if (num_bytes_of_contraction < 2)
+      num_bytes_of_contraction = 2;
+  }
+
+  // Check that the numbers add up.
+  if (num_bytes_without_contraction + num_bytes_of_contraction != 16)
+    return false;
+
+  *out_num_bytes_of_contraction = num_bytes_of_contraction;
+  return true;
+}
+
+// Converts a hex comonent into a number. This cannot fail since the caller has
+// already verified that each character in the string was a hex digit, and
+// that there were no more than 4 characters.
+template<typename CHAR>
+uint16 IPv6HexComponentToNumber(const CHAR* spec,
+                                const url_parse::Component& component) {
+  DCHECK(component.len <= 4);
+
+  // Copy the hex string into a C-string.
+  char buf[5];
+  for (int i = 0; i < component.len; ++i)
+    buf[i] = static_cast<char>(spec[component.begin + i]);
+  buf[component.len] = '\0';
+
+  // Convert it to a number (overflow is not possible, since with 4 hex
+  // characters we can at most have a 16 bit number).
+  return static_cast<uint16>(_strtoui64(buf, NULL, 16));
+}
+
+// Converts an IPv6 address to a 128-bit number (network byte order), returning
+// true on success. False means that the input was not a valid IPv6 address.
+template<typename CHAR, typename UCHAR>
+bool DoIPv6AddressToNumber(const CHAR* spec,
+                           const url_parse::Component& host,
+                           unsigned char address[16]) {
+  // Make sure the component is bounded by '[' and ']'.
+  int end = host.end();
+  if (!host.is_nonempty() || spec[host.begin] != '[' || spec[end - 1] != ']')
+    return false;
+
+  // Exclude the square brackets.
+  url_parse::Component ipv6_comp(host.begin + 1, host.len - 2);
+
+  // Parse the IPv6 address -- identify where all the colon separated hex
+  // components are, the "::" contraction, and the embedded IPv4 address.
+  IPv6Parsed ipv6_parsed;
+  if (!DoParseIPv6<CHAR, UCHAR>(spec, ipv6_comp, &ipv6_parsed))
+    return false;
+
+  // Do some basic size checks to make sure that the address doesn't
+  // specify more than 128 bits or fewer than 128 bits. This also resolves
+  // how may zero bytes the "::" contraction represents.
+  int num_bytes_of_contraction;
+  if (!CheckIPv6ComponentsSize(ipv6_parsed, &num_bytes_of_contraction))
+    return false;
+
+  int cur_index_in_address = 0;
+
+  // Loop through each hex components, and contraction in order.
+  for (int i = 0; i <= ipv6_parsed.num_hex_components; ++i) {
+    // Append the contraction if it appears before this component.
+    if (i == ipv6_parsed.index_of_contraction) {
+      for (int j = 0; j < num_bytes_of_contraction; ++j)
+        address[cur_index_in_address++] = 0;
+    }
+    // Append the hex component's value.
+    if (i != ipv6_parsed.num_hex_components) {
+      // Get the 16-bit value for this hex component.
+      uint16 number = IPv6HexComponentToNumber<CHAR>(
+          spec, ipv6_parsed.hex_components[i]);
+      // Append to |address|, in network byte order.
+      address[cur_index_in_address++] = (number & 0xFF00) >> 8;
+      address[cur_index_in_address++] = (number & 0x00FF);
+    }
+  }
+
+  // If there was an IPv4 section, convert it into a 32-bit number and append
+  // it to |address|.
+  if (ipv6_parsed.ipv4_component.is_valid()) {
+    // Append the 32-bit number to |address|.
+    int ignored_num_ipv4_components;
+    if (CanonHostInfo::IPV4 !=
+        IPv4AddressToNumber(spec,
+                            ipv6_parsed.ipv4_component,
+                            &address[cur_index_in_address],
+                            &ignored_num_ipv4_components))
+      return false;
+  }
+
+  return true;
+}
+
+// Searches for the longest sequence of zeros in |address|, and writes the
+// range into |contraction_range|. The run of zeros must be at least 16 bits,
+// and if there is a tie the first is chosen.
+void ChooseIPv6ContractionRange(const unsigned char address[16],
+                                url_parse::Component* contraction_range) {
+  // The longest run of zeros in |address| seen so far.
+  url_parse::Component max_range;
+
+  // The current run of zeros in |address| being iterated over.
+  url_parse::Component cur_range;
+
+  for (int i = 0; i < 16; i += 2) {
+    // Test for 16 bits worth of zero.
+    bool is_zero = (address[i] == 0 && address[i + 1] == 0);
+
+    if (is_zero) {
+      // Add the zero to the current range (or start a new one).
+      if (!cur_range.is_valid())
+        cur_range = url_parse::Component(i, 0);
+      cur_range.len += 2;
+    }
+
+    if (!is_zero || i == 14) {
+      // Just completed a run of zeros. If the run is greater than 16 bits,
+      // it is a candidate for the contraction.
+      if (cur_range.len > 2 && cur_range.len > max_range.len) {
+        max_range = cur_range;
+      }
+      cur_range.reset();
+    }
+  }
+  *contraction_range = max_range;
+}
+
+// Return true if we've made a final IPV6/BROKEN decision, false if the result
+// is NEUTRAL, and we could use a second opinion.
+template<typename CHAR, typename UCHAR>
+bool DoCanonicalizeIPv6Address(const CHAR* spec,
+                               const url_parse::Component& host,
+                               CanonOutput* output,
+                               CanonHostInfo* host_info) {
+  // Turn the IP address into a 128 bit number.
+  if (!IPv6AddressToNumber(spec, host, host_info->address)) {
+    // If it's not an IPv6 address, scan for characters that should *only*
+    // exist in an IPv6 address.
+    for (int i = host.begin; i < host.end(); i++) {
+      switch (spec[i]) {
+        case '[':
+        case ']':
+        case ':':
+          host_info->family = CanonHostInfo::BROKEN;
+          return true;
+      }
+    }
+
+    // No invalid characters.  Could still be IPv4 or a hostname.
+    host_info->family = CanonHostInfo::NEUTRAL;
+    return false;
+  }
+
+  host_info->out_host.begin = output->length();
+  output->push_back('[');
+  AppendIPv6Address(host_info->address, output);
+  output->push_back(']');
+  host_info->out_host.len = output->length() - host_info->out_host.begin;
+
+  host_info->family = CanonHostInfo::IPV6;
+  return true;
+}
+
+}  // namespace
+
+void AppendIPv4Address(const unsigned char address[4], CanonOutput* output) {
+  for (int i = 0; i < 4; i++) {
+    char str[16];
+    _itoa_s(address[i], str, 10);
+
+    for (int ch = 0; str[ch] != 0; ch++)
+      output->push_back(str[ch]);
+
+    if (i != 3)
+      output->push_back('.');
+  }
+}
+
+void AppendIPv6Address(const unsigned char address[16], CanonOutput* output) {
+  // We will output the address according to the rules in:
+  // http://tools.ietf.org/html/draft-kawamura-ipv6-text-representation-01#section-4
+
+  // Start by finding where to place the "::" contraction (if any).
+  url_parse::Component contraction_range;
+  ChooseIPv6ContractionRange(address, &contraction_range);
+
+  for (int i = 0; i <= 14;) {
+    // We check 2 bytes at a time, from bytes (0, 1) to (14, 15), inclusive.
+    DCHECK(i % 2 == 0);
+    if (i == contraction_range.begin && contraction_range.len > 0) {
+      // Jump over the contraction.
+      if (i == 0)
+        output->push_back(':');
+      output->push_back(':');
+      i = contraction_range.end();
+    } else {
+      // Consume the next 16 bits from |address|.
+      int x = address[i] << 8 | address[i + 1];
+
+      i += 2;
+
+      // Stringify the 16 bit number (at most requires 4 hex digits).
+      char str[5];
+      _itoa_s(x, str, 16);
+      for (int ch = 0; str[ch] != 0; ++ch)
+        output->push_back(str[ch]);
+
+      // Put a colon after each number, except the last.
+      if (i < 16)
+        output->push_back(':');
+    }
+  }
+}
+
+bool FindIPv4Components(const char* spec,
+                        const url_parse::Component& host,
+                        url_parse::Component components[4]) {
+  return DoFindIPv4Components<char, unsigned char>(spec, host, components);
+}
+
+bool FindIPv4Components(const char16* spec,
+                        const url_parse::Component& host,
+                        url_parse::Component components[4]) {
+  return DoFindIPv4Components<char16, char16>(spec, host, components);
+}
+
+void CanonicalizeIPAddress(const char* spec,
+                           const url_parse::Component& host,
+                           CanonOutput* output,
+                           CanonHostInfo* host_info) {
+  if (DoCanonicalizeIPv4Address<char, unsigned char>(
+          spec, host, output, host_info))
+    return;
+  if (DoCanonicalizeIPv6Address<char, unsigned char>(
+          spec, host, output, host_info))
+    return;
+}
+
+void CanonicalizeIPAddress(const char16* spec,
+                           const url_parse::Component& host,
+                           CanonOutput* output,
+                           CanonHostInfo* host_info) {
+  if (DoCanonicalizeIPv4Address<char16, char16>(
+          spec, host, output, host_info))
+    return;
+  if (DoCanonicalizeIPv6Address<char16, char16>(
+          spec, host, output, host_info))
+    return;
+}
+
+CanonHostInfo::Family IPv4AddressToNumber(const char* spec,
+                                          const url_parse::Component& host,
+                                          unsigned char address[4],
+                                          int* num_ipv4_components) {
+  return DoIPv4AddressToNumber<char>(spec, host, address, num_ipv4_components);
+}
+
+CanonHostInfo::Family IPv4AddressToNumber(const char16* spec,
+                                          const url_parse::Component& host,
+                                          unsigned char address[4],
+                                          int* num_ipv4_components) {
+  return DoIPv4AddressToNumber<char16>(
+      spec, host, address, num_ipv4_components);
+}
+
+bool IPv6AddressToNumber(const char* spec,
+                         const url_parse::Component& host,
+                         unsigned char address[16]) {
+  return DoIPv6AddressToNumber<char, unsigned char>(spec, host, address);
+}
+
+bool IPv6AddressToNumber(const char16* spec,
+                         const url_parse::Component& host,
+                         unsigned char address[16]) {
+  return DoIPv6AddressToNumber<char16, char16>(spec, host, address);
+}
+
+}  // namespace url_canon