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 #include <android-base/format.h>
22 #include <netdutils/InternetAddresses.h>
23 
24 namespace {
25 
26 // Returns a tuple of references to the elements of a.
make_tie(const sockaddr_in & a)27 auto make_tie(const sockaddr_in& a) {
28     return std::tie(a.sin_port, a.sin_addr.s_addr);
29 }
30 
31 // Returns a tuple of references to the elements of a.
make_tie(const sockaddr_in6 & a)32 auto make_tie(const sockaddr_in6& a) {
33     // Skip flowinfo, which is not relevant.
34     return std::tie(
35         a.sin6_port,
36         a.sin6_addr,
37         a.sin6_scope_id
38     );
39 }
40 
41 } // namespace
42 
43 // These binary operators make sockaddr_storage comparable.  They need to be
44 // in the global namespace so that the std::tuple < and == operators can see them.
operator <(const in6_addr & x,const in6_addr & y)45 static bool operator <(const in6_addr& x, const in6_addr& y) {
46     return std::lexicographical_compare(
47             std::begin(x.s6_addr), std::end(x.s6_addr),
48             std::begin(y.s6_addr), std::end(y.s6_addr));
49 }
50 
operator ==(const in6_addr & x,const in6_addr & y)51 static bool operator ==(const in6_addr& x, const in6_addr& y) {
52     return std::equal(
53             std::begin(x.s6_addr), std::end(x.s6_addr),
54             std::begin(y.s6_addr), std::end(y.s6_addr));
55 }
56 
operator <(const sockaddr_storage & x,const sockaddr_storage & y)57 static bool operator <(const sockaddr_storage& x, const sockaddr_storage& y) {
58     if (x.ss_family != y.ss_family) {
59         return x.ss_family < y.ss_family;
60     }
61     // Same address family.
62     if (x.ss_family == AF_INET) {
63         const sockaddr_in& x_sin = reinterpret_cast<const sockaddr_in&>(x);
64         const sockaddr_in& y_sin = reinterpret_cast<const sockaddr_in&>(y);
65         return make_tie(x_sin) < make_tie(y_sin);
66     } else if (x.ss_family == AF_INET6) {
67         const sockaddr_in6& x_sin6 = reinterpret_cast<const sockaddr_in6&>(x);
68         const sockaddr_in6& y_sin6 = reinterpret_cast<const sockaddr_in6&>(y);
69         return make_tie(x_sin6) < make_tie(y_sin6);
70     }
71     return false;  // Unknown address type.  This is an error.
72 }
73 
operator ==(const sockaddr_storage & x,const sockaddr_storage & y)74 static bool operator ==(const sockaddr_storage& x, const sockaddr_storage& y) {
75     if (x.ss_family != y.ss_family) {
76         return false;
77     }
78     // Same address family.
79     if (x.ss_family == AF_INET) {
80         const sockaddr_in& x_sin = reinterpret_cast<const sockaddr_in&>(x);
81         const sockaddr_in& y_sin = reinterpret_cast<const sockaddr_in&>(y);
82         return make_tie(x_sin) == make_tie(y_sin);
83     } else if (x.ss_family == AF_INET6) {
84         const sockaddr_in6& x_sin6 = reinterpret_cast<const sockaddr_in6&>(x);
85         const sockaddr_in6& y_sin6 = reinterpret_cast<const sockaddr_in6&>(y);
86         return make_tie(x_sin6) == make_tie(y_sin6);
87     }
88     return false;  // Unknown address type.  This is an error.
89 }
90 
91 namespace android {
92 namespace net {
93 
94 // This comparison ignores ports and certificates.
operator ()(const DnsTlsServer & x,const DnsTlsServer & y) const95 bool AddressComparator::operator() (const DnsTlsServer& x, const DnsTlsServer& y) const {
96     if (x.ss.ss_family != y.ss.ss_family) {
97         return x.ss.ss_family < y.ss.ss_family;
98     }
99     // Same address family.
100     if (x.ss.ss_family == AF_INET) {
101         const sockaddr_in& x_sin = reinterpret_cast<const sockaddr_in&>(x.ss);
102         const sockaddr_in& y_sin = reinterpret_cast<const sockaddr_in&>(y.ss);
103         return x_sin.sin_addr.s_addr < y_sin.sin_addr.s_addr;
104     } else if (x.ss.ss_family == AF_INET6) {
105         const sockaddr_in6& x_sin6 = reinterpret_cast<const sockaddr_in6&>(x.ss);
106         const sockaddr_in6& y_sin6 = reinterpret_cast<const sockaddr_in6&>(y.ss);
107         return std::tie(x_sin6.sin6_addr, x_sin6.sin6_scope_id) <
108                 std::tie(y_sin6.sin6_addr, y_sin6.sin6_scope_id);
109     }
110     return false;  // Unknown address type.  This is an error.
111 }
112 
113 // Returns a tuple of references to the elements of s.
make_tie(const DnsTlsServer & s)114 auto make_tie(const DnsTlsServer& s) {
115     return std::tie(s.ss, s.name, s.protocol);
116 }
117 
operator <(const DnsTlsServer & other) const118 bool DnsTlsServer::operator <(const DnsTlsServer& other) const {
119     return make_tie(*this) < make_tie(other);
120 }
121 
operator ==(const DnsTlsServer & other) const122 bool DnsTlsServer::operator ==(const DnsTlsServer& other) const {
123     return make_tie(*this) == make_tie(other);
124 }
125 
wasExplicitlyConfigured() const126 bool DnsTlsServer::wasExplicitlyConfigured() const {
127     return !name.empty();
128 }
129 
toIpString() const130 std::string DnsTlsServer::toIpString() const {
131     return netdutils::IPSockAddr::toIPSockAddr(ss).ip().toString();
132 }
133 
toString() const134 std::string DnsTlsServer::toString() const {
135     return fmt::format("{{{}/{}}}", toIpString(), name);
136 }
137 
138 }  // namespace net
139 }  // namespace android
140