1 /* 2 * Copyright (C) 2019 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 18 #pragma once 19 20 #include <arpa/nameser.h> 21 #include <netdb.h> 22 23 #include <string> 24 #include <vector> 25 26 #include <aidl/android/net/INetd.h> 27 #include <gtest/gtest.h> 28 #include <netdutils/InternetAddresses.h> 29 30 #include "dns_responder/dns_responder.h" 31 32 class ScopeBlockedUIDRule { 33 using INetd = aidl::android::net::INetd; 34 35 public: ScopeBlockedUIDRule(INetd * netSrv,uid_t testUid)36 ScopeBlockedUIDRule(INetd* netSrv, uid_t testUid) 37 : mNetSrv(netSrv), mTestUid(testUid), mSavedUid(getuid()) { 38 // Add drop rule for testUid. Also enable the standby chain because it might not be 39 // enabled. Unfortunately we cannot use FIREWALL_CHAIN_NONE, or custom iptables rules, for 40 // this purpose because netd calls fchown() on the DNS query sockets, and "iptables -m 41 // owner" matches the UID of the socket creator, not the UID set by fchown(). 42 // TODO: migrate FIREWALL_CHAIN_NONE to eBPF as well. 43 EXPECT_TRUE(mNetSrv->firewallEnableChildChain(INetd::FIREWALL_CHAIN_STANDBY, true).isOk()); 44 EXPECT_TRUE(mNetSrv->firewallSetUidRule(INetd::FIREWALL_CHAIN_STANDBY, mTestUid, 45 INetd::FIREWALL_RULE_DENY) 46 .isOk()); 47 EXPECT_TRUE(seteuid(mTestUid) == 0); 48 }; ~ScopeBlockedUIDRule()49 ~ScopeBlockedUIDRule() { 50 // Restore uid 51 EXPECT_TRUE(seteuid(mSavedUid) == 0); 52 // Remove drop rule for testUid, and disable the standby chain. 53 EXPECT_TRUE(mNetSrv->firewallSetUidRule(INetd::FIREWALL_CHAIN_STANDBY, mTestUid, 54 INetd::FIREWALL_RULE_ALLOW) 55 .isOk()); 56 EXPECT_TRUE(mNetSrv->firewallEnableChildChain(INetd::FIREWALL_CHAIN_STANDBY, false).isOk()); 57 } 58 59 private: 60 INetd* mNetSrv; 61 const uid_t mTestUid; 62 const uid_t mSavedUid; 63 }; 64 65 class ScopedChangeUID { 66 public: ScopedChangeUID(uid_t testUid)67 ScopedChangeUID(uid_t testUid) : mTestUid(testUid), mSavedUid(getuid()) { 68 EXPECT_TRUE(seteuid(mTestUid) == 0); 69 }; ~ScopedChangeUID()70 ~ScopedChangeUID() { EXPECT_TRUE(seteuid(mSavedUid) == 0); } 71 72 private: 73 const uid_t mTestUid; 74 const uid_t mSavedUid; 75 }; 76 77 struct DnsRecord { 78 std::string host_name; // host name 79 ns_type type; // record type 80 std::string addr; // ipv4/v6 address 81 }; 82 83 // TODO: make this dynamic and stop depending on implementation details. 84 constexpr int TEST_NETID = 30; 85 // Use maximum reserved appId for applications to avoid conflict with existing uids. 86 constexpr int TEST_UID = 99999; 87 88 static constexpr char kLocalHost[] = "localhost"; 89 static constexpr char kLocalHostAddr[] = "127.0.0.1"; 90 static constexpr char kIp6LocalHost[] = "ip6-localhost"; 91 static constexpr char kIp6LocalHostAddr[] = "::1"; 92 static constexpr char kHelloExampleCom[] = "hello.example.com."; 93 static constexpr char kHelloExampleComAddrV4[] = "1.2.3.4"; 94 static constexpr char kHelloExampleComAddrV6[] = "::1.2.3.4"; 95 static constexpr char kExampleComDomain[] = ".example.com"; 96 97 constexpr size_t kMaxmiumLabelSize = 63; // see RFC 1035 section 2.3.4. 98 99 static const std::vector<uint8_t> kHelloExampleComQueryV4 = { 100 /* Header */ 101 0x00, 0x00, /* Transaction ID: 0x0000 */ 102 0x01, 0x00, /* Flags: rd */ 103 0x00, 0x01, /* Questions: 1 */ 104 0x00, 0x00, /* Answer RRs: 0 */ 105 0x00, 0x00, /* Authority RRs: 0 */ 106 0x00, 0x00, /* Additional RRs: 0 */ 107 /* Queries */ 108 0x05, 0x68, 0x65, 0x6c, 0x6c, 0x6f, 0x07, 0x65, 0x78, 0x61, 0x6d, 0x70, 0x6c, 0x65, 0x03, 109 0x63, 0x6f, 0x6d, 0x00, /* Name: hello.example.com */ 110 0x00, 0x01, /* Type: A */ 111 0x00, 0x01 /* Class: IN */ 112 }; 113 114 static const std::vector<uint8_t> kHelloExampleComResponseV4 = { 115 /* Header */ 116 0x00, 0x00, /* Transaction ID: 0x0000 */ 117 0x81, 0x80, /* Flags: qr rd ra */ 118 0x00, 0x01, /* Questions: 1 */ 119 0x00, 0x01, /* Answer RRs: 1 */ 120 0x00, 0x00, /* Authority RRs: 0 */ 121 0x00, 0x00, /* Additional RRs: 0 */ 122 /* Queries */ 123 0x05, 0x68, 0x65, 0x6c, 0x6c, 0x6f, 0x07, 0x65, 0x78, 0x61, 0x6d, 0x70, 0x6c, 0x65, 0x03, 124 0x63, 0x6f, 0x6d, 0x00, /* Name: hello.example.com */ 125 0x00, 0x01, /* Type: A */ 126 0x00, 0x01, /* Class: IN */ 127 /* Answers */ 128 0x05, 0x68, 0x65, 0x6c, 0x6c, 0x6f, 0x07, 0x65, 0x78, 0x61, 0x6d, 0x70, 0x6c, 0x65, 0x03, 129 0x63, 0x6f, 0x6d, 0x00, /* Name: hello.example.com */ 130 0x00, 0x01, /* Type: A */ 131 0x00, 0x01, /* Class: IN */ 132 0x00, 0x00, 0x00, 0x00, /* Time to live: 0 */ 133 0x00, 0x04, /* Data length: 4 */ 134 0x01, 0x02, 0x03, 0x04 /* Address: 1.2.3.4 */ 135 }; 136 137 // Illegal hostnames 138 static constexpr char kBadCharAfterPeriodHost[] = "hello.example.^com."; 139 static constexpr char kBadCharBeforePeriodHost[] = "hello.example^.com."; 140 static constexpr char kBadCharAtTheEndHost[] = "hello.example.com^."; 141 static constexpr char kBadCharInTheMiddleOfLabelHost[] = "hello.ex^ample.com."; 142 143 static const test::DNSHeader kDefaultDnsHeader = { 144 // Don't need to initialize the flag "id" and "rd" because DNS responder assigns them from 145 // query to response. See RFC 1035 section 4.1.1. 146 .id = 0, // unused. should be assigned from query to response 147 .ra = false, // recursive query support is not available 148 .rcode = ns_r_noerror, // no error 149 .qr = true, // message is a response 150 .opcode = QUERY, // a standard query 151 .aa = false, // answer/authority portion was not authenticated by the server 152 .tr = false, // message is not truncated 153 .rd = false, // unused. should be assigned from query to response 154 .ad = false, // non-authenticated data is unacceptable 155 }; 156 157 // The CNAME chain records for building a response message which exceeds 512 bytes. 158 // 159 // Ignoring the other fields of the message, the response message has 8 CNAMEs in 5 answer RRs 160 // and each CNAME has 77 bytes as the follows. The response message at least has 616 bytes in 161 // answer section and has already exceeded 512 bytes totally. 162 // 163 // The CNAME is presented as: 164 // 0 1 64 65 72 73 76 77 165 // +---+--........--+---+---+---+---+---+---+---+---+---+---+---+---+---+ 166 // | 63| {x, .., x} | 7 | e | x | a | m | p | l | e | 3 | c | o | m | 0 | 167 // +---+--........--+---+---+---+---+---+---+---+---+---+---+---+---+---+ 168 // ^-- x = {a, b, c, d} 169 // 170 const std::string kCnameA = std::string(kMaxmiumLabelSize, 'a') + kExampleComDomain + "."; 171 const std::string kCnameB = std::string(kMaxmiumLabelSize, 'b') + kExampleComDomain + "."; 172 const std::string kCnameC = std::string(kMaxmiumLabelSize, 'c') + kExampleComDomain + "."; 173 const std::string kCnameD = std::string(kMaxmiumLabelSize, 'd') + kExampleComDomain + "."; 174 const std::vector<DnsRecord> kLargeCnameChainRecords = { 175 {kHelloExampleCom, ns_type::ns_t_cname, kCnameA}, 176 {kCnameA, ns_type::ns_t_cname, kCnameB}, 177 {kCnameB, ns_type::ns_t_cname, kCnameC}, 178 {kCnameC, ns_type::ns_t_cname, kCnameD}, 179 {kCnameD, ns_type::ns_t_a, kHelloExampleComAddrV4}, 180 }; 181 182 // TODO: Integrate GetNumQueries relevent functions 183 size_t GetNumQueries(const test::DNSResponder& dns, const char* name); 184 size_t GetNumQueriesForProtocol(const test::DNSResponder& dns, const int protocol, 185 const char* name); 186 size_t GetNumQueriesForType(const test::DNSResponder& dns, ns_type type, const char* name); 187 std::string ToString(const hostent* he); 188 std::string ToString(const addrinfo* ai); 189 std::string ToString(const android::netdutils::ScopedAddrinfo& ai); 190 std::string ToString(const sockaddr_storage* addr); 191 std::vector<std::string> ToStrings(const hostent* he); 192 std::vector<std::string> ToStrings(const addrinfo* ai); 193 std::vector<std::string> ToStrings(const android::netdutils::ScopedAddrinfo& ai); 194 195 // Wait for |condition| to be met until |timeout|. 196 bool PollForCondition(const std::function<bool()>& condition, 197 std::chrono::milliseconds timeout = std::chrono::milliseconds(1000)); 198