Home | History | Annotate | Download | only in dns 
      1 /*
      2  * Copyright (C) 2017 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #include "dns/DnsTlsServer.h"
     18 
     19 #include <algorithm>
     20 
     21 namespace {
     22 
     23 // Returns a tuple of references to the elements of a.
     24 auto make_tie(const sockaddr_in& a) {
     25     return std::tie(a.sin_port, a.sin_addr.s_addr);
     26 }
     27 
     28 // Returns a tuple of references to the elements of a.
     29 auto make_tie(const sockaddr_in6& a) {
     30     // Skip flowinfo, which is not relevant.
     31     return std::tie(
     32         a.sin6_port,
     33         a.sin6_addr,
     34         a.sin6_scope_id
     35     );
     36 }
     37 
     38 } // namespace
     39 
     40 // These binary operators make sockaddr_storage comparable.  They need to be
     41 // in the global namespace so that the std::tuple < and == operators can see them.
     42 static bool operator <(const in6_addr& x, const in6_addr& y) {
     43     return std::lexicographical_compare(
     44             std::begin(x.s6_addr), std::end(x.s6_addr),
     45             std::begin(y.s6_addr), std::end(y.s6_addr));
     46 }
     47 
     48 static bool operator ==(const in6_addr& x, const in6_addr& y) {
     49     return std::equal(
     50             std::begin(x.s6_addr), std::end(x.s6_addr),
     51             std::begin(y.s6_addr), std::end(y.s6_addr));
     52 }
     53 
     54 static bool operator <(const sockaddr_storage& x, const sockaddr_storage& y) {
     55     if (x.ss_family != y.ss_family) {
     56         return x.ss_family < y.ss_family;
     57     }
     58     // Same address family.
     59     if (x.ss_family == AF_INET) {
     60         const sockaddr_in& x_sin = reinterpret_cast<const sockaddr_in&>(x);
     61         const sockaddr_in& y_sin = reinterpret_cast<const sockaddr_in&>(y);
     62         return make_tie(x_sin) < make_tie(y_sin);
     63     } else if (x.ss_family == AF_INET6) {
     64         const sockaddr_in6& x_sin6 = reinterpret_cast<const sockaddr_in6&>(x);
     65         const sockaddr_in6& y_sin6 = reinterpret_cast<const sockaddr_in6&>(y);
     66         return make_tie(x_sin6) < make_tie(y_sin6);
     67     }
     68     return false;  // Unknown address type.  This is an error.
     69 }
     70 
     71 static bool operator ==(const sockaddr_storage& x, const sockaddr_storage& y) {
     72     if (x.ss_family != y.ss_family) {
     73         return false;
     74     }
     75     // Same address family.
     76     if (x.ss_family == AF_INET) {
     77         const sockaddr_in& x_sin = reinterpret_cast<const sockaddr_in&>(x);
     78         const sockaddr_in& y_sin = reinterpret_cast<const sockaddr_in&>(y);
     79         return make_tie(x_sin) == make_tie(y_sin);
     80     } else if (x.ss_family == AF_INET6) {
     81         const sockaddr_in6& x_sin6 = reinterpret_cast<const sockaddr_in6&>(x);
     82         const sockaddr_in6& y_sin6 = reinterpret_cast<const sockaddr_in6&>(y);
     83         return make_tie(x_sin6) == make_tie(y_sin6);
     84     }
     85     return false;  // Unknown address type.  This is an error.
     86 }
     87 
     88 namespace android {
     89 namespace net {
     90 
     91 // This comparison ignores ports and fingerprints.
     92 bool AddressComparator::operator() (const DnsTlsServer& x, const DnsTlsServer& y) const {
     93     if (x.ss.ss_family != y.ss.ss_family) {
     94         return x.ss.ss_family < y.ss.ss_family;
     95     }
     96     // Same address family.
     97     if (x.ss.ss_family == AF_INET) {
     98         const sockaddr_in& x_sin = reinterpret_cast<const sockaddr_in&>(x.ss);
     99         const sockaddr_in& y_sin = reinterpret_cast<const sockaddr_in&>(y.ss);
    100         return x_sin.sin_addr.s_addr < y_sin.sin_addr.s_addr;
    101     } else if (x.ss.ss_family == AF_INET6) {
    102         const sockaddr_in6& x_sin6 = reinterpret_cast<const sockaddr_in6&>(x.ss);
    103         const sockaddr_in6& y_sin6 = reinterpret_cast<const sockaddr_in6&>(y.ss);
    104         return std::tie(x_sin6.sin6_addr, x_sin6.sin6_scope_id) <
    105                 std::tie(y_sin6.sin6_addr, y_sin6.sin6_scope_id);
    106     }
    107     return false;  // Unknown address type.  This is an error.
    108 }
    109 
    110 // Returns a tuple of references to the elements of s.
    111 auto make_tie(const DnsTlsServer& s) {
    112     return std::tie(
    113         s.ss,
    114         s.name,
    115         s.fingerprints,
    116         s.protocol
    117     );
    118 }
    119 
    120 bool DnsTlsServer::operator <(const DnsTlsServer& other) const {
    121     return make_tie(*this) < make_tie(other);
    122 }
    123 
    124 bool DnsTlsServer::operator ==(const DnsTlsServer& other) const {
    125     return make_tie(*this) == make_tie(other);
    126 }
    127 
    128 bool DnsTlsServer::wasExplicitlyConfigured() const {
    129     return !name.empty() || !fingerprints.empty();
    130 }
    131 
    132 }  // namespace net
    133 }  // namespace android
    134