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 the biggest two reserved appId for applications to avoid conflict with existing uids. 86 constexpr int TEST_UID = 99999; 87 constexpr int TEST_UID2 = 99998; 88 89 static constexpr char kLocalHost[] = "localhost"; 90 static constexpr char kLocalHostAddr[] = "127.0.0.1"; 91 static constexpr char kIp6LocalHost[] = "ip6-localhost"; 92 static constexpr char kIp6LocalHostAddr[] = "::1"; 93 static constexpr char kHelloExampleCom[] = "hello.example.com."; 94 static constexpr char kHelloExampleComAddrV4[] = "1.2.3.4"; 95 static constexpr char kHelloExampleComAddrV6[] = "::1.2.3.4"; 96 static constexpr char kExampleComDomain[] = ".example.com"; 97 98 constexpr size_t kMaxmiumLabelSize = 63; // see RFC 1035 section 2.3.4. 99 100 static const std::vector<uint8_t> kHelloExampleComQueryV4 = { 101 /* Header */ 102 0x00, 0x00, /* Transaction ID: 0x0000 */ 103 0x01, 0x00, /* Flags: rd */ 104 0x00, 0x01, /* Questions: 1 */ 105 0x00, 0x00, /* Answer RRs: 0 */ 106 0x00, 0x00, /* Authority RRs: 0 */ 107 0x00, 0x00, /* Additional RRs: 0 */ 108 /* Queries */ 109 0x05, 0x68, 0x65, 0x6c, 0x6c, 0x6f, 0x07, 0x65, 0x78, 0x61, 0x6d, 0x70, 0x6c, 0x65, 0x03, 110 0x63, 0x6f, 0x6d, 0x00, /* Name: hello.example.com */ 111 0x00, 0x01, /* Type: A */ 112 0x00, 0x01 /* Class: IN */ 113 }; 114 115 static const std::vector<uint8_t> kHelloExampleComResponseV4 = { 116 /* Header */ 117 0x00, 0x00, /* Transaction ID: 0x0000 */ 118 0x81, 0x80, /* Flags: qr rd ra */ 119 0x00, 0x01, /* Questions: 1 */ 120 0x00, 0x01, /* Answer RRs: 1 */ 121 0x00, 0x00, /* Authority RRs: 0 */ 122 0x00, 0x00, /* Additional RRs: 0 */ 123 /* Queries */ 124 0x05, 0x68, 0x65, 0x6c, 0x6c, 0x6f, 0x07, 0x65, 0x78, 0x61, 0x6d, 0x70, 0x6c, 0x65, 0x03, 125 0x63, 0x6f, 0x6d, 0x00, /* Name: hello.example.com */ 126 0x00, 0x01, /* Type: A */ 127 0x00, 0x01, /* Class: IN */ 128 /* Answers */ 129 0x05, 0x68, 0x65, 0x6c, 0x6c, 0x6f, 0x07, 0x65, 0x78, 0x61, 0x6d, 0x70, 0x6c, 0x65, 0x03, 130 0x63, 0x6f, 0x6d, 0x00, /* Name: hello.example.com */ 131 0x00, 0x01, /* Type: A */ 132 0x00, 0x01, /* Class: IN */ 133 0x00, 0x00, 0x00, 0x00, /* Time to live: 0 */ 134 0x00, 0x04, /* Data length: 4 */ 135 0x01, 0x02, 0x03, 0x04 /* Address: 1.2.3.4 */ 136 }; 137 138 // Illegal hostnames 139 static constexpr char kBadCharAfterPeriodHost[] = "hello.example.^com."; 140 static constexpr char kBadCharBeforePeriodHost[] = "hello.example^.com."; 141 static constexpr char kBadCharAtTheEndHost[] = "hello.example.com^."; 142 static constexpr char kBadCharInTheMiddleOfLabelHost[] = "hello.ex^ample.com."; 143 144 static const test::DNSHeader kDefaultDnsHeader = { 145 // Don't need to initialize the flag "id" and "rd" because DNS responder assigns them from 146 // query to response. See RFC 1035 section 4.1.1. 147 .id = 0, // unused. should be assigned from query to response 148 .ra = false, // recursive query support is not available 149 .rcode = ns_r_noerror, // no error 150 .qr = true, // message is a response 151 .opcode = QUERY, // a standard query 152 .aa = false, // answer/authority portion was not authenticated by the server 153 .tr = false, // message is not truncated 154 .rd = false, // unused. should be assigned from query to response 155 .ad = false, // non-authenticated data is unacceptable 156 }; 157 158 // The CNAME chain records for building a response message which exceeds 512 bytes. 159 // 160 // Ignoring the other fields of the message, the response message has 8 CNAMEs in 5 answer RRs 161 // and each CNAME has 77 bytes as the follows. The response message at least has 616 bytes in 162 // answer section and has already exceeded 512 bytes totally. 163 // 164 // The CNAME is presented as: 165 // 0 1 64 65 72 73 76 77 166 // +---+--........--+---+---+---+---+---+---+---+---+---+---+---+---+---+ 167 // | 63| {x, .., x} | 7 | e | x | a | m | p | l | e | 3 | c | o | m | 0 | 168 // +---+--........--+---+---+---+---+---+---+---+---+---+---+---+---+---+ 169 // ^-- x = {a, b, c, d} 170 // 171 const std::string kCnameA = std::string(kMaxmiumLabelSize, 'a') + kExampleComDomain + "."; 172 const std::string kCnameB = std::string(kMaxmiumLabelSize, 'b') + kExampleComDomain + "."; 173 const std::string kCnameC = std::string(kMaxmiumLabelSize, 'c') + kExampleComDomain + "."; 174 const std::string kCnameD = std::string(kMaxmiumLabelSize, 'd') + kExampleComDomain + "."; 175 const std::vector<DnsRecord> kLargeCnameChainRecords = { 176 {kHelloExampleCom, ns_type::ns_t_cname, kCnameA}, 177 {kCnameA, ns_type::ns_t_cname, kCnameB}, 178 {kCnameB, ns_type::ns_t_cname, kCnameC}, 179 {kCnameC, ns_type::ns_t_cname, kCnameD}, 180 {kCnameD, ns_type::ns_t_a, kHelloExampleComAddrV4}, 181 }; 182 183 // TODO: Integrate GetNumQueries relevent functions 184 size_t GetNumQueries(const test::DNSResponder& dns, const char* name); 185 size_t GetNumQueriesForProtocol(const test::DNSResponder& dns, const int protocol, 186 const char* name); 187 size_t GetNumQueriesForType(const test::DNSResponder& dns, ns_type type, const char* name); 188 std::string ToString(const hostent* he); 189 std::string ToString(const addrinfo* ai); 190 std::string ToString(const android::netdutils::ScopedAddrinfo& ai); 191 std::string ToString(const sockaddr_storage* addr); 192 std::vector<std::string> ToStrings(const hostent* he); 193 std::vector<std::string> ToStrings(const addrinfo* ai); 194 std::vector<std::string> ToStrings(const android::netdutils::ScopedAddrinfo& ai); 195 196 // Wait for |condition| to be met until |timeout|. 197 bool PollForCondition(const std::function<bool()>& condition, 198 std::chrono::milliseconds timeout = std::chrono::milliseconds(1000)); 199