dns_util.cc revision c2e0dbddbe15c98d52c4786dac06cb8952a8ae6d
15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Copyright (c) 2011 The Chromium Authors. All rights reserved. 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Use of this source code is governed by a BSD-style license that can be 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// found in the LICENSE file. 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 55821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "net/base/dns_util.h" 65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <cstring> 85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 95821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace net { 105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Based on DJB's public domain code. 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)bool DNSDomainFromDot(const base::StringPiece& dotted, std::string* out) { 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const char* buf = dotted.data(); 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) unsigned n = dotted.size(); 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) char label[63]; 165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) unsigned int labellen = 0; /* <= sizeof label */ 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) char name[255]; 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) unsigned int namelen = 0; /* <= sizeof name */ 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) char ch; 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) for (;;) { 225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (!n) 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) break; 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ch = *buf++; 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) --n; 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (ch == '.') { 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (labellen) { 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (namelen + labellen + 1 > sizeof name) 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return false; 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) name[namelen++] = labellen; 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) memcpy(name + namelen, label, labellen); 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) namelen += labellen; 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) labellen = 0; 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) continue; 365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (labellen >= sizeof label) 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return false; 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) label[labellen++] = ch; 405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (labellen) { 435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (namelen + labellen + 1 > sizeof name) 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return false; 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) name[namelen++] = labellen; 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) memcpy(name + namelen, label, labellen); 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) namelen += labellen; 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) labellen = 0; 495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (namelen + 1 > sizeof name) 525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return false; 535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) name[namelen++] = 0; // This is the root label (of length 0). 545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) *out = std::string(name, namelen); 565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return true; 575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)std::string DNSDomainToString(const base::StringPiece& domain) { 605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) std::string ret; 615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) for (unsigned i = 0; i < domain.size() && domain[i]; i += domain[i] + 1) { 635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#if CHAR_MIN < 0 645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (domain[i] < 0) 65c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) return std::string(); 665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#endif 675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (domain[i] > 63) 68c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) return std::string(); 695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (i) 715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ret += "."; 725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (static_cast<unsigned>(domain[i]) + i + 1 > domain.size()) 74c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) return std::string(); 755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) domain.substr(i + 1, domain[i]).AppendToString(&ret); 775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return ret; 795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)bool IsSTD3ASCIIValidCharacter(char c) { 825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (c <= 0x2c) 835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return false; 845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (c >= 0x7b) 855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return false; 865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (c >= 0x2e && c <= 0x2f) 875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return false; 885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (c >= 0x3a && c <= 0x40) 895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return false; 905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (c >= 0x5b && c <= 0x60) 915821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return false; 925821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return true; 935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 945821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)std::string TrimEndingDot(const base::StringPiece& host) { 965821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) base::StringPiece host_trimmed = host; 975821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) size_t len = host_trimmed.length(); 985821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (len > 1 && host_trimmed[len - 1] == '.') { 995821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) host_trimmed.remove_suffix(1); 1005821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1015821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return host_trimmed.as_string(); 1025821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 1035821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1045821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} // namespace net 105