| // Copyright (c) 2009 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/dns_util.h" |
| |
| #include <cstring> |
| |
| namespace net { |
| |
| // Based on DJB's public domain code. |
| bool DNSDomainFromDot(const std::string& dotted, std::string* out) { |
| const char* buf = dotted.data(); |
| unsigned n = dotted.size(); |
| char label[63]; |
| unsigned int labellen = 0; /* <= sizeof label */ |
| char name[255]; |
| unsigned int namelen = 0; /* <= sizeof name */ |
| char ch; |
| |
| for (;;) { |
| if (!n) |
| break; |
| ch = *buf++; |
| --n; |
| if (ch == '.') { |
| if (labellen) { |
| if (namelen + labellen + 1 > sizeof name) |
| return false; |
| name[namelen++] = labellen; |
| memcpy(name + namelen, label, labellen); |
| namelen += labellen; |
| labellen = 0; |
| } |
| continue; |
| } |
| if (labellen >= sizeof label) |
| return false; |
| label[labellen++] = ch; |
| } |
| |
| if (labellen) { |
| if (namelen + labellen + 1 > sizeof name) |
| return false; |
| name[namelen++] = labellen; |
| memcpy(name + namelen, label, labellen); |
| namelen += labellen; |
| labellen = 0; |
| } |
| |
| if (namelen + 1 > sizeof name) |
| return false; |
| name[namelen++] = 0; // This is the root label (of length 0). |
| |
| *out = std::string(name, namelen); |
| return true; |
| } |
| |
| std::string DNSDomainToString(const std::string& domain) { |
| std::string ret; |
| |
| for (unsigned i = 0; i < domain.size() && domain[i]; i += domain[i] + 1) { |
| if (domain[i] < 0 || domain[i] > 63) |
| return ""; |
| |
| if (i) |
| ret += "."; |
| |
| if (static_cast<unsigned>(domain[i]) + i + 1 > domain.size()) |
| return ""; |
| |
| ret += domain.substr(i + 1, domain[i]); |
| } |
| return ret; |
| } |
| |
| bool IsSTD3ASCIIValidCharacter(char c) { |
| if (c <= 0x2c) |
| return false; |
| if (c >= 0x7b) |
| return false; |
| if (c >= 0x2e && c <= 0x2f) |
| return false; |
| if (c >= 0x3a && c <= 0x40) |
| return false; |
| if (c >= 0x5b && c <= 0x60) |
| return false; |
| return true; |
| } |
| |
| std::string TrimEndingDot(const std::string& host) { |
| std::string host_trimmed = host; |
| size_t len = host_trimmed.length(); |
| if (len > 1 && host_trimmed[len - 1] == '.') |
| host_trimmed.erase(len - 1); |
| return host_trimmed; |
| } |
| |
| } // namespace net |