blob: 7ab60c6a5d9e40b70d49becde219ab6bc9485eac [file] [log] [blame]
// Copyright (c) 2011 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_util.h"
#include <cstring>
namespace net {
// Based on DJB's public domain code.
bool DNSDomainFromDot(const base::StringPiece& dotted, std::string* out) {
const char* buf = dotted.data();
unsigned n = dotted.size();
char label[63];
size_t labellen = 0; /* <= sizeof label */
char name[255];
size_t namelen = 0; /* <= sizeof name */
char ch;
for (;;) {
if (!n)
break;
ch = *buf++;
--n;
if (ch == '.') {
// Don't allow empty labels per http://crbug.com/456391.
if (!labellen)
return false;
if (namelen + labellen + 1 > sizeof name)
return false;
name[namelen++] = static_cast<char>(labellen);
memcpy(name + namelen, label, labellen);
namelen += labellen;
labellen = 0;
continue;
}
if (labellen >= sizeof label)
return false;
label[labellen++] = ch;
}
// Allow empty label at end of name to disable suffix search.
if (labellen) {
if (namelen + labellen + 1 > sizeof name)
return false;
name[namelen++] = static_cast<char>(labellen);
memcpy(name + namelen, label, labellen);
namelen += labellen;
labellen = 0;
}
if (namelen + 1 > sizeof name)
return false;
if (namelen == 0) // Empty names e.g. "", "." are not valid.
return false;
name[namelen++] = 0; // This is the root label (of length 0).
*out = std::string(name, namelen);
return true;
}
std::string DNSDomainToString(const base::StringPiece& domain) {
std::string ret;
for (unsigned i = 0; i < domain.size() && domain[i]; i += domain[i] + 1) {
#if CHAR_MIN < 0
if (domain[i] < 0)
return std::string();
#endif
if (domain[i] > 63)
return std::string();
if (i)
ret += ".";
if (static_cast<unsigned>(domain[i]) + i + 1 > domain.size())
return std::string();
domain.substr(i + 1, domain[i]).AppendToString(&ret);
}
return ret;
}
} // namespace net