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// 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/string_tokenizer.h"
#include "base/string_util.h"
namespace net {
void ParseHosts(const std::string& contents, DnsHosts* dns_hosts) {
CHECK(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, "#");
line_parts.set_options(StringTokenizer::RETURN_DELIMS);
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 :
ADDRESS_FAMILY_IPV6;
while (tokens.GetNext()) {
DnsHostsKey key(tokens.token(), fam);
StringToLowerASCII(&(key.first));
IPAddressNumber& mapped_ip = hosts[key];
if (mapped_ip.empty())
mapped_ip = ip;
// else ignore this entry (first hit counts)
}
}
}
}
}
DnsHostsReader::DnsHostsReader(const FilePath& path,
const CallbackType& callback)
: path_(path),
callback_(callback),
success_(false) {
DCHECK(!callback.is_null());
}
DnsHostsReader::DnsHostsReader(const FilePath& path)
: path_(path),
success_(false) {
}
// Reads the contents of the file at |path| into |str| if the total length is
// less than |max_size|.
static bool ReadFile(const FilePath& path, int64 max_size, std::string* str) {
int64 size;
if (!file_util::GetFileSize(path, &size) || size > max_size)
return false;
return file_util::ReadFileToString(path, str);
}
void DnsHostsReader::DoWork() {
success_ = false;
dns_hosts_.clear();
// Missing file indicates empty HOSTS.
if (!file_util::PathExists(path_)) {
success_ = true;
return;
}
std::string contents;
const int64 kMaxHostsSize = 1 << 16;
if (ReadFile(path_, kMaxHostsSize, &contents)) {
success_ = true;
ParseHosts(contents, &dns_hosts_);
}
}
void DnsHostsReader::OnWorkFinished() {
DCHECK(!IsCancelled());
if (success_)
callback_.Run(dns_hosts_);
}
DnsHostsReader::~DnsHostsReader() {}
} // namespace net
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