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 "DnsTlsServer.h"
18 
19 #include <algorithm>
20 
21 namespace {
22 
23 // Returns a tuple of references to the elements of a.
make_tie(const sockaddr_in & 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.
make_tie(const sockaddr_in6 & 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.
operator <(const in6_addr & x,const in6_addr & y)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 
operator ==(const in6_addr & x,const in6_addr & y)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 
operator <(const sockaddr_storage & x,const sockaddr_storage & y)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 
operator ==(const sockaddr_storage & x,const sockaddr_storage & y)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 certificates.
operator ()(const DnsTlsServer & x,const DnsTlsServer & y) const92 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.
make_tie(const DnsTlsServer & s)111 auto make_tie(const DnsTlsServer& s) {
112     return std::tie(s.ss, s.name, s.protocol, s.connectTimeout);
113 }
114 
operator <(const DnsTlsServer & other) const115 bool DnsTlsServer::operator <(const DnsTlsServer& other) const {
116     return make_tie(*this) < make_tie(other);
117 }
118 
operator ==(const DnsTlsServer & other) const119 bool DnsTlsServer::operator ==(const DnsTlsServer& other) const {
120     return make_tie(*this) == make_tie(other);
121 }
122 
wasExplicitlyConfigured() const123 bool DnsTlsServer::wasExplicitlyConfigured() const {
124     return !name.empty();
125 }
126 
127 }  // namespace net
128 }  // namespace android
129