blob: 66290b461bc080aeaa99091e72afccc7a354fccd [file] [log] [blame]
// Copyright (c) 2012 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/dns/dns_hosts.h"
#include "base/file_util.h"
#include "base/logging.h"
#include "base/metrics/histogram.h"
#include "base/string_tokenizer.h"
#include "base/string_util.h"
namespace net {
void ParseHosts(const std::string& contents, DnsHosts* dns_hosts) {
DnsHosts& hosts = *dns_hosts;
// Split into lines. Accept CR for Windows.
StringTokenizer contents_lines(contents, "\n\r");
while (contents_lines.GetNext()) {
// Ignore comments after '#'.
std::string line = contents_lines.token();
StringTokenizer line_parts(line, "#");
if (line_parts.GetNext() && !line_parts.token_is_delim()) {
// Split and trim whitespace.
std::string part = line_parts.token();
StringTokenizer tokens(part, " \t");
if (tokens.GetNext()) {
IPAddressNumber ip;
// TODO(szym): handle %iface notation on mac
if (!ParseIPLiteralToNumber(tokens.token(), &ip))
continue; // Ignore malformed lines.
AddressFamily fam = (ip.size() == 4) ? ADDRESS_FAMILY_IPV4 :
while (tokens.GetNext()) {
DnsHostsKey key(tokens.token(), fam);
IPAddressNumber& mapped_ip = hosts[key];
if (mapped_ip.empty())
mapped_ip = ip;
// else ignore this entry (first hit counts)
bool ParseHostsFile(const FilePath& path, DnsHosts* dns_hosts) {
// Missing file indicates empty HOSTS.
if (!file_util::PathExists(path))
return true;
int64 size;
if (!file_util::GetFileSize(path, &size))
return false;
UMA_HISTOGRAM_COUNTS("AsyncDNS.HostsSize", size);
// Reject HOSTS files larger than |kMaxHostsSize|.
const int64 kMaxHostsSize = 1 << 16;
if (size > kMaxHostsSize)
return false;
std::string contents;
if (!file_util::ReadFileToString(path, &contents))
return false;
ParseHosts(contents, dns_hosts);
return true;
} // namespace net