Merge bitcoin/bitcoin#31022: test: Add mockable steady clock, tests for PCP and NATPMP implementations

0f716f28896c6edfcd4e2a2b25c88f478a029c7b qa: cover PROTOCOL_ERROR variant in PCP unit tests (Antoine Poinsot)
fc700bb47fd8b6ac58f612b932aef0e361686cc3 test: Add tests for PCP and NATPMP implementations (laanwj)
caf952103317a7fa8bd2bceb35d4e8ace5968906 net: Use mockable steady clock in PCP implementation (laanwj)
03648321ecb704b69e47eed7e3df6a779aee8f11 util: Add mockable steady_clock (laanwj)
ab1d3ece026844e682676673b8a461964a5b3ce4 net: Add optional length checking to CService::SetSockAddr (laanwj)

Pull request description:

  Add a NodeSteadyClock, a steady_clock that can be mocked with millisecond precision. Use this in the PCP implementation.

  Then add a mock for a simple scriptable UDP server,, which is used to test various code paths (including successful mappings, timeouts and errors) in the PCP and NATPMP implementations.

  Includes "net: Add optional length checking to CService::SetSockAddr" from #31014 as a prerequisite.

ACKs for top commit:
  darosior:
    re-ACK 0f716f28896c6edfcd4e2a2b25c88f478a029c7b
  i-am-yuvi:
    Concept ACK 0f716f28896c6edfcd4e2a2b25c88f478a029c7b
  achow101:
    ACK 0f716f28896c6edfcd4e2a2b25c88f478a029c7b

Tree-SHA512: 6f91b24e6fe46a3fded7a13972efd77c98e6ef235f8898e4ae44068c5df32d1cdabb22cb66c351b338dc98cb2073b624e43607a28107f4999302bfbe7a138229

src/common/netif.cpp

@@ -169,16 +169,9 @@ std::optional<CNetAddr> QueryDefaultGatewayImpl(sa_family_t family)
 
 std::optional<CNetAddr> FromSockAddr(const struct sockaddr* addr)
 {
-    // Check valid length. Note that sa_len is not part of POSIX, and exists on MacOS and some BSDs only, so we can't
-    // do this check in SetSockAddr.
-    if (!(addr->sa_family == AF_INET && addr->sa_len == sizeof(struct sockaddr_in)) &&
-        !(addr->sa_family == AF_INET6 && addr->sa_len == sizeof(struct sockaddr_in6))) {
-        return std::nullopt;
-    }
-
     // Fill in a CService from the sockaddr, then drop the port part.
     CService service;
-    if (service.SetSockAddr(addr)) {
+    if (service.SetSockAddr(addr, addr->sa_len)) {
         return (CNetAddr)service;
     }
     return std::nullopt;

src/common/pcp.cpp

@@ -235,9 +235,9 @@ std::optional<std::vector<uint8_t>> PCPSendRecv(Sock &sock, const std::string &p
         }
 
         // Wait for response(s) until we get a valid response, a network error, or time out.
-        auto cur_time = time_point_cast<milliseconds>(steady_clock::now());
+        auto cur_time = time_point_cast<milliseconds>(MockableSteadyClock::now());
         auto deadline = cur_time + timeout_per_try;
-        while ((cur_time = time_point_cast<milliseconds>(steady_clock::now())) < deadline) {
+        while ((cur_time = time_point_cast<milliseconds>(MockableSteadyClock::now())) < deadline) {
             Sock::Event occurred = 0;
             if (!sock.Wait(deadline - cur_time, Sock::RECV, &occurred)) {
                 LogPrintLevel(BCLog::NET, BCLog::Level::Warning, "%s: Could not wait on socket: %s\n", protocol, NetworkErrorString(WSAGetLastError()));
@@ -426,7 +426,7 @@ std::variant<MappingResult, MappingError> PCPRequestPortMap(const PCPMappingNonc
         return MappingError::NETWORK_ERROR;
     }
     CService internal;
-    if (!internal.SetSockAddr((struct sockaddr*)&internal_addr)) return MappingError::NETWORK_ERROR;
+    if (!internal.SetSockAddr((struct sockaddr*)&internal_addr, internal_addrlen)) return MappingError::NETWORK_ERROR;
     LogPrintLevel(BCLog::NET, BCLog::Level::Debug, "pcp: Internal address after connect: %s\n", internal.ToStringAddr());
 
     // Build request packet. Make sure the packet is zeroed so that reserved fields are zero

src/net.cpp

@@ -387,7 +387,7 @@ static CAddress GetBindAddress(const Sock& sock)
     struct sockaddr_storage sockaddr_bind;
     socklen_t sockaddr_bind_len = sizeof(sockaddr_bind);
     if (!sock.GetSockName((struct sockaddr*)&sockaddr_bind, &sockaddr_bind_len)) {
-        addr_bind.SetSockAddr((const struct sockaddr*)&sockaddr_bind);
+        addr_bind.SetSockAddr((const struct sockaddr*)&sockaddr_bind, sockaddr_bind_len);
     } else {
         LogPrintLevel(BCLog::NET, BCLog::Level::Warning, "getsockname failed\n");
     }
@@ -1746,7 +1746,7 @@ void CConnman::AcceptConnection(const ListenSocket& hListenSocket) {
         return;
     }
 
-    if (!addr.SetSockAddr((const struct sockaddr*)&sockaddr)) {
+    if (!addr.SetSockAddr((const struct sockaddr*)&sockaddr, len)) {
         LogPrintLevel(BCLog::NET, BCLog::Level::Warning, "Unknown socket family\n");
     } else {
         addr = CAddress{MaybeFlipIPv6toCJDNS(addr), NODE_NONE};

src/netaddress.cpp

@@ -807,13 +807,15 @@ CService::CService(const struct sockaddr_in6 &addr) : CNetAddr(addr.sin6_addr, a
    assert(addr.sin6_family == AF_INET6);
 }
 
-bool CService::SetSockAddr(const struct sockaddr *paddr)
+bool CService::SetSockAddr(const struct sockaddr *paddr, socklen_t addrlen)
 {
     switch (paddr->sa_family) {
     case AF_INET:
+        if (addrlen != sizeof(struct sockaddr_in)) return false;
         *this = CService(*(const struct sockaddr_in*)paddr);
         return true;
     case AF_INET6:
+        if (addrlen != sizeof(struct sockaddr_in6)) return false;
         *this = CService(*(const struct sockaddr_in6*)paddr);
         return true;
     default:

src/netaddress.h

@@ -539,7 +539,14 @@ public:
     explicit CService(const struct sockaddr_in& addr);
     uint16_t GetPort() const;
     bool GetSockAddr(struct sockaddr* paddr, socklen_t* addrlen) const;
-    bool SetSockAddr(const struct sockaddr* paddr);
+    /**
+     * Set CService from a network sockaddr.
+     * @param[in] paddr Pointer to sockaddr structure
+     * @param[in] addrlen Length of sockaddr structure in bytes. This will be checked to exactly match the length of
+     * a socket address of the provided family, unless std::nullopt is passed
+     * @returns true on success
+     */
+    bool SetSockAddr(const struct sockaddr* paddr, socklen_t addrlen);
     /**
      * Get the address family
      * @returns AF_UNSPEC if unspecified

src/test/CMakeLists.txt

@@ -87,6 +87,7 @@ add_executable(test_bitcoin
   netbase_tests.cpp
   node_warnings_tests.cpp
   orphanage_tests.cpp
+  pcp_tests.cpp
   peerman_tests.cpp
   pmt_tests.cpp
   policy_fee_tests.cpp

src/test/pcp_tests.cpp

@@ -0,0 +1,699 @@
+// Copyright (c) 2024 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <common/pcp.h>
+#include <netbase.h>
+#include <test/util/logging.h>
+#include <test/util/setup_common.h>
+#include <util/time.h>
+
+#include <boost/test/unit_test.hpp>
+
+#include <algorithm>
+#include <deque>
+
+using namespace std::literals;
+
+/// UDP test server operation.
+struct TestOp {
+    std::chrono::milliseconds delay;
+    enum Op {
+        SEND, // Expect send (with optional data)
+        RECV, // Expect receive (with data)
+        NOP,  // Just delay
+    } op;
+    std::vector<uint8_t> data;
+
+    //! Injected error.
+    //! Set this field to a non-zero value to return the errno code from send or receive operation.
+    int error;
+
+    TestOp(std::chrono::milliseconds delay_in, Op op_in, const std::vector<uint8_t> &data_in, int error_in):
+        delay(delay_in), op(op_in), data(data_in), error(error_in) {}
+};
+
+/// Save the value of CreateSock and restore when the test ends.
+class PCPTestingSetup : public BasicTestingSetup
+{
+public:
+    explicit PCPTestingSetup(const ChainType chainType = ChainType::MAIN,
+                             TestOpts opts = {})
+        : BasicTestingSetup{chainType, opts},
+          m_create_sock_orig{CreateSock}
+    {
+        const std::optional<CService> local_ipv4{Lookup("192.168.0.6", 1, false)};
+        const std::optional<CService> local_ipv6{Lookup("2a10:1234:5678:9abc:def0:1234:5678:9abc", 1, false)};
+        const std::optional<CService> gateway_ipv4{Lookup("192.168.0.1", 1, false)};
+        const std::optional<CService> gateway_ipv6{Lookup("2a10:1234:5678:9abc:def0:0000:0000:0000", 1, false)};
+        BOOST_REQUIRE(local_ipv4 && local_ipv6 && gateway_ipv4 && gateway_ipv6);
+        default_local_ipv4 = *local_ipv4;
+        default_local_ipv6 = *local_ipv6;
+        default_gateway_ipv4 = *gateway_ipv4;
+        default_gateway_ipv6 = *gateway_ipv6;
+
+        struct in_addr inaddr_any;
+        inaddr_any.s_addr = htonl(INADDR_ANY);
+        bind_any_ipv4 = CNetAddr(inaddr_any);
+    }
+
+    ~PCPTestingSetup()
+    {
+        CreateSock = m_create_sock_orig;
+        MockableSteadyClock::ClearMockTime();
+    }
+
+    // Default testing nonce.
+    static constexpr PCPMappingNonce TEST_NONCE{0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc};
+    // Default network addresses.
+    CNetAddr default_local_ipv4;
+    CNetAddr default_local_ipv6;
+    CNetAddr default_gateway_ipv4;
+    CNetAddr default_gateway_ipv6;
+    // IPv4 bind
+    CNetAddr bind_any_ipv4;
+private:
+    const decltype(CreateSock) m_create_sock_orig;
+};
+
+/** Simple scripted UDP server emulation for testing.
+ */
+class PCPTestSock final : public Sock
+{
+public:
+    // Note: we awkwardly mark all methods as const, and properties as mutable,
+    // because Sock expects all networking calls to be const.
+    explicit PCPTestSock(const CNetAddr &local_ip, const CNetAddr &gateway_ip, const std::vector<TestOp> &script)
+        : Sock{INVALID_SOCKET},
+          m_script(script),
+          m_local_ip(local_ip),
+          m_gateway_ip(gateway_ip)
+    {
+        ElapseTime(std::chrono::seconds(0)); // start mocking steady time
+        PrepareOp();
+    }
+
+    PCPTestSock& operator=(Sock&& other) override
+    {
+        assert(false && "Move of Sock into PCPTestSock not allowed.");
+        return *this;
+    }
+
+    ssize_t Send(const void* data, size_t len, int) const override {
+        if (!m_connected) return -1;
+        Span in_pkt = Span(static_cast<const uint8_t*>(data), len);
+        if (AtEndOfScript() || CurOp().op != TestOp::SEND) {
+            // Ignore sends after end of script, or sends when we expect a receive.
+            FailScript();
+            return len;
+        }
+        if (CurOp().error) return -1; // Inject failure
+        if (CurOp().data.empty() || std::ranges::equal(CurOp().data, in_pkt)) {
+            AdvanceOp();
+        } else {
+            // Wrong send, fail script
+            FailScript();
+        }
+        return len;
+    }
+
+    ssize_t Recv(void* buf, size_t len, int flags) const override
+    {
+        if (!m_connected || AtEndOfScript() || CurOp().op != TestOp::RECV || m_time_left != 0s) {
+            return -1;
+        }
+        if (CurOp().error) return -1; // Inject failure
+        const auto &recv_pkt = CurOp().data;
+        const size_t consume_bytes{std::min(len, recv_pkt.size())};
+        std::memcpy(buf, recv_pkt.data(), consume_bytes);
+        if ((flags & MSG_PEEK) == 0) {
+            AdvanceOp();
+        }
+        return consume_bytes;
+    }
+
+    int Connect(const sockaddr* sa, socklen_t sa_len) const override {
+        CService service;
+        if (service.SetSockAddr(sa, sa_len) && service == CService(m_gateway_ip, 5351)) {
+            if (m_bound.IsBindAny()) { // If bind-any, bind to local ip.
+                m_bound = CService(m_local_ip, 0);
+            }
+            if (m_bound.GetPort() == 0) { // If no port assigned, assign port 1.
+                m_bound = CService(m_bound, 1);
+            }
+            m_connected = true;
+            return 0;
+        }
+        return -1;
+    }
+
+    int Bind(const sockaddr* sa, socklen_t sa_len) const override {
+        CService service;
+        if (service.SetSockAddr(sa, sa_len)) {
+            // Can only bind to one of our local ips
+            if (!service.IsBindAny() && service != m_local_ip) {
+                return -1;
+            }
+            m_bound = service;
+            return 0;
+        }
+        return -1;
+    }
+
+    int Listen(int) const override { return -1; }
+
+    std::unique_ptr<Sock> Accept(sockaddr* addr, socklen_t* addr_len) const override
+    {
+        return nullptr;
+    };
+
+    int GetSockOpt(int level, int opt_name, void* opt_val, socklen_t* opt_len) const override
+    {
+        return -1;
+    }
+
+    int SetSockOpt(int, int, const void*, socklen_t) const override { return 0; }
+
+    int GetSockName(sockaddr* name, socklen_t* name_len) const override
+    {
+        // Return the address we've been bound to.
+        return m_bound.GetSockAddr(name, name_len) ? 0 : -1;
+    }
+
+    bool SetNonBlocking() const override { return true; }
+
+    bool IsSelectable() const override { return true; }
+
+    bool Wait(std::chrono::milliseconds timeout,
+              Event requested,
+              Event* occurred = nullptr) const override
+    {
+        // Only handles receive events.
+        if (AtEndOfScript() || requested != Sock::RECV) {
+            ElapseTime(timeout);
+        } else {
+            std::chrono::milliseconds delay = std::min(m_time_left, timeout);
+            ElapseTime(delay);
+            m_time_left -= delay;
+            if (CurOp().op == TestOp::RECV && m_time_left == 0s && occurred != nullptr) {
+                *occurred = Sock::RECV;
+            }
+            if (CurOp().op == TestOp::NOP) {
+                // This was a pure delay operation, move to the next op.
+                AdvanceOp();
+            }
+        }
+        return true;
+    }
+
+    bool WaitMany(std::chrono::milliseconds timeout, EventsPerSock& events_per_sock) const override
+    {
+        return false;
+    }
+
+    bool IsConnected(std::string&) const override
+    {
+        return true;
+    }
+
+private:
+    const std::vector<TestOp> m_script;
+    mutable size_t m_script_ptr = 0;
+    mutable std::chrono::milliseconds m_time_left;
+    mutable std::chrono::milliseconds m_time{MockableSteadyClock::INITIAL_MOCK_TIME};
+    mutable bool m_connected{false};
+    mutable CService m_bound;
+    mutable CNetAddr m_local_ip;
+    mutable CNetAddr m_gateway_ip;
+
+    void ElapseTime(std::chrono::milliseconds duration) const
+    {
+        m_time += duration;
+        MockableSteadyClock::SetMockTime(m_time);
+    }
+
+    bool AtEndOfScript() const { return m_script_ptr == m_script.size(); }
+    const TestOp &CurOp() const {
+        BOOST_REQUIRE(m_script_ptr < m_script.size());
+        return m_script[m_script_ptr];
+    }
+
+    void PrepareOp() const {
+        if (AtEndOfScript()) return;
+        m_time_left = CurOp().delay;
+    }
+
+    void AdvanceOp() const
+    {
+        m_script_ptr += 1;
+        PrepareOp();
+    }
+
+    void FailScript() const { m_script_ptr = m_script.size(); }
+};
+
+BOOST_FIXTURE_TEST_SUITE(pcp_tests, PCPTestingSetup)
+
+// NAT-PMP IPv4 good-weather scenario.
+BOOST_AUTO_TEST_CASE(natpmp_ipv4)
+{
+    const std::vector<TestOp> script{
+        {
+            0ms, TestOp::SEND,
+            {
+                0x00, 0x00, // version, opcode (request external IP)
+            }, 0
+        },
+        {
+            2ms, TestOp::RECV,
+            {
+                0x00, 0x80, 0x00, 0x00, // version, opcode (external IP), result code (success)
+                0x66, 0xfd, 0xa1, 0xee, // seconds sinds start of epoch
+                0x01, 0x02, 0x03, 0x04, // external IP address
+            }, 0
+        },
+        {
+            0ms, TestOp::SEND,
+            {
+                0x00, 0x02, 0x00, 0x00, // version, opcode (request map TCP)
+                0x04, 0xd2, 0x04, 0xd2, // internal port, suggested external port
+                0x00, 0x00, 0x03, 0xe8, // requested mapping lifetime in seconds
+            }, 0
+        },
+        {
+            2ms, TestOp::RECV,
+            {
+                0x00, 0x82, 0x00, 0x00, // version, opcode (mapped TCP)
+                0x66, 0xfd, 0xa1, 0xee, // seconds sinds start of epoch
+                0x04, 0xd2, 0x04, 0xd2, // internal port, mapped external port
+                0x00, 0x00, 0x01, 0xf4, // mapping lifetime in seconds
+            }, 0
+        },
+    };
+    CreateSock = [this, &script](int domain, int type, int protocol) {
+        if (domain == AF_INET && type == SOCK_DGRAM && protocol == IPPROTO_UDP) return std::make_unique<PCPTestSock>(default_local_ipv4, default_gateway_ipv4, script);
+        return std::unique_ptr<PCPTestSock>();
+    };
+
+    auto res = NATPMPRequestPortMap(default_gateway_ipv4, 1234, 1000, 1, 200ms);
+
+    MappingResult* mapping = std::get_if<MappingResult>(&res);
+    BOOST_REQUIRE(mapping);
+    BOOST_CHECK_EQUAL(mapping->version, 0);
+    BOOST_CHECK_EQUAL(mapping->internal.ToStringAddrPort(), "192.168.0.6:1234");
+    BOOST_CHECK_EQUAL(mapping->external.ToStringAddrPort(), "1.2.3.4:1234");
+    BOOST_CHECK_EQUAL(mapping->lifetime, 500);
+}
+
+// PCP IPv4 good-weather scenario.
+BOOST_AUTO_TEST_CASE(pcp_ipv4)
+{
+    const std::vector<TestOp> script{
+        {
+            0ms, TestOp::SEND,
+            {
+                0x02, 0x01, 0x00, 0x00, // version, opcode
+                0x00, 0x00, 0x03, 0xe8, // lifetime
+                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xc0, 0xa8, 0x00, 0x06, // internal IP
+                0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, // nonce
+                0x06, 0x00, 0x00, 0x00, // protocol (TCP), reserved
+                0x04, 0xd2, 0x04, 0xd2, // internal port, suggested external port
+                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00, // suggested external IP
+            }, 0
+        },
+        {
+            250ms, TestOp::RECV, // 250ms delay before answer
+            {
+                0x02, 0x81, 0x00, 0x00, // version, opcode, result success
+                0x00, 0x00, 0x01, 0xf4, // granted lifetime
+                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // reserved
+                0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, // nonce
+                0x06, 0x00, 0x00, 0x00, // protocol (TCP), reserved
+                0x04, 0xd2, 0x04, 0xd2, // internal port, assigned external port
+                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0x01, 0x02, 0x03, 0x04, // assigned external IP
+            }, 0
+        },
+    };
+    CreateSock = [this, &script](int domain, int type, int protocol) {
+        if (domain == AF_INET && type == SOCK_DGRAM && protocol == IPPROTO_UDP) return std::make_unique<PCPTestSock>(default_local_ipv4, default_gateway_ipv4, script);
+        return std::unique_ptr<PCPTestSock>();
+    };
+
+    auto res = PCPRequestPortMap(TEST_NONCE, default_gateway_ipv4, bind_any_ipv4, 1234, 1000, 1, 1000ms);
+
+    MappingResult* mapping = std::get_if<MappingResult>(&res);
+    BOOST_REQUIRE(mapping);
+    BOOST_CHECK_EQUAL(mapping->version, 2);
+    BOOST_CHECK_EQUAL(mapping->internal.ToStringAddrPort(), "192.168.0.6:1234");
+    BOOST_CHECK_EQUAL(mapping->external.ToStringAddrPort(), "1.2.3.4:1234");
+    BOOST_CHECK_EQUAL(mapping->lifetime, 500);
+}
+
+// PCP IPv6 good-weather scenario.
+BOOST_AUTO_TEST_CASE(pcp_ipv6)
+{
+    const std::vector<TestOp> script{
+        {
+            0ms, TestOp::SEND,
+            {
+                0x02, 0x01, 0x00, 0x00, // version, opcode
+                0x00, 0x00, 0x03, 0xe8, // lifetime
+                0x2a, 0x10, 0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, 0xde, 0xf0, 0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, // internal IP
+                0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, // nonce
+                0x06, 0x00, 0x00, 0x00, // protocol (TCP), reserved
+                0x04, 0xd2, 0x04, 0xd2, // internal port, suggested external port
+                0x2a, 0x10, 0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, 0xde, 0xf0, 0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, // suggested external IP
+            }, 0
+        },
+        {
+            500ms, TestOp::RECV, // 500ms delay before answer
+            {
+                0x02, 0x81, 0x00, 0x00, // version, opcode, result success
+                0x00, 0x00, 0x01, 0xf4, // granted lifetime
+                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // reserved
+                0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, // nonce
+                0x06, 0x00, 0x00, 0x00, // protocol (TCP), reserved
+                0x04, 0xd2, 0x04, 0xd2, // internal port, assigned external port
+                0x2a, 0x10, 0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, 0xde, 0xf0, 0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, // suggested external IP
+            }, 0
+        },
+    };
+    CreateSock = [this, &script](int domain, int type, int protocol) {
+        if (domain == AF_INET6 && type == SOCK_DGRAM && protocol == IPPROTO_UDP) return std::make_unique<PCPTestSock>(default_local_ipv6, default_gateway_ipv6, script);
+        return std::unique_ptr<PCPTestSock>();
+    };
+
+    auto res = PCPRequestPortMap(TEST_NONCE, default_gateway_ipv6, default_local_ipv6, 1234, 1000, 1, 1000ms);
+
+    MappingResult* mapping = std::get_if<MappingResult>(&res);
+    BOOST_REQUIRE(mapping);
+    BOOST_CHECK_EQUAL(mapping->version, 2);
+    BOOST_CHECK_EQUAL(mapping->internal.ToStringAddrPort(), "[2a10:1234:5678:9abc:def0:1234:5678:9abc]:1234");
+    BOOST_CHECK_EQUAL(mapping->external.ToStringAddrPort(), "[2a10:1234:5678:9abc:def0:1234:5678:9abc]:1234");
+    BOOST_CHECK_EQUAL(mapping->lifetime, 500);
+}
+
+// PCP timeout.
+BOOST_AUTO_TEST_CASE(pcp_timeout)
+{
+    const std::vector<TestOp> script{};
+    CreateSock = [this, &script](int domain, int type, int protocol) {
+        if (domain == AF_INET && type == SOCK_DGRAM && protocol == IPPROTO_UDP) return std::make_unique<PCPTestSock>(default_local_ipv4, default_gateway_ipv4, script);
+        return std::unique_ptr<PCPTestSock>();
+    };
+
+    ASSERT_DEBUG_LOG("pcp: Retrying (1)");
+    ASSERT_DEBUG_LOG("pcp: Retrying (2)");
+    ASSERT_DEBUG_LOG("pcp: Timeout");
+
+    auto res = PCPRequestPortMap(TEST_NONCE, default_gateway_ipv4, bind_any_ipv4, 1234, 1000, 3, 2000ms);
+
+    MappingError* err = std::get_if<MappingError>(&res);
+    BOOST_REQUIRE(err);
+    BOOST_CHECK_EQUAL(*err, MappingError::NETWORK_ERROR);
+}
+
+// PCP failure receiving (router sends ICMP port closed).
+BOOST_AUTO_TEST_CASE(pcp_connrefused)
+{
+    const std::vector<TestOp> script{
+        {
+            0ms, TestOp::SEND,
+            { // May send anything.
+            }, 0
+        },
+        {
+            0ms, TestOp::RECV,
+            {
+            }, ECONNREFUSED
+        },
+    };
+    CreateSock = [this, &script](int domain, int type, int protocol) {
+        if (domain == AF_INET && type == SOCK_DGRAM && protocol == IPPROTO_UDP) return std::make_unique<PCPTestSock>(default_local_ipv4, default_gateway_ipv4, script);
+        return std::unique_ptr<PCPTestSock>();
+    };
+
+    ASSERT_DEBUG_LOG("pcp: Could not receive response");
+
+    auto res = PCPRequestPortMap(TEST_NONCE, default_gateway_ipv4, bind_any_ipv4, 1234, 1000, 3, 2000ms);
+
+    MappingError* err = std::get_if<MappingError>(&res);
+    BOOST_REQUIRE(err);
+    BOOST_CHECK_EQUAL(*err, MappingError::NETWORK_ERROR);
+}
+
+// PCP IPv6 success after one timeout.
+BOOST_AUTO_TEST_CASE(pcp_ipv6_timeout_success)
+{
+    const std::vector<TestOp> script{
+        {
+            0ms, TestOp::SEND,
+            {
+                0x02, 0x01, 0x00, 0x00, // version, opcode
+                0x00, 0x00, 0x03, 0xe8, // lifetime
+                0x2a, 0x10, 0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, 0xde, 0xf0, 0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, // internal IP
+                0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, // nonce
+                0x06, 0x00, 0x00, 0x00, // protocol (TCP), reserved
+                0x04, 0xd2, 0x04, 0xd2, // internal port, suggested external port
+                0x2a, 0x10, 0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, 0xde, 0xf0, 0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, // suggested external IP
+            }, 0
+        },
+        {
+            2001ms, TestOp::NOP, // Takes longer to respond than timeout of 2000ms
+            {}, 0
+        },
+        {
+            0ms, TestOp::SEND, // Repeated send (try 2)
+            {
+                0x02, 0x01, 0x00, 0x00, // version, opcode
+                0x00, 0x00, 0x03, 0xe8, // lifetime
+                0x2a, 0x10, 0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, 0xde, 0xf0, 0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, // internal IP
+                0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, // nonce
+                0x06, 0x00, 0x00, 0x00, // protocol (TCP), reserved
+                0x04, 0xd2, 0x04, 0xd2, // internal port, suggested external port
+                0x2a, 0x10, 0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, 0xde, 0xf0, 0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, // suggested external IP
+            }, 0
+        },
+        {
+            200ms, TestOp::RECV, // This time we're in time
+            {
+                0x02, 0x81, 0x00, 0x00, // version, opcode, result success
+                0x00, 0x00, 0x01, 0xf4, // granted lifetime
+                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // reserved
+                0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, // nonce
+                0x06, 0x00, 0x00, 0x00, // protocol (TCP), reserved
+                0x04, 0xd2, 0x04, 0xd2, // internal port, assigned external port
+                0x2a, 0x10, 0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, 0xde, 0xf0, 0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, // suggested external IP
+            }, 0
+        },
+    };
+    CreateSock = [this, &script](int domain, int type, int protocol) {
+        if (domain == AF_INET6 && type == SOCK_DGRAM && protocol == IPPROTO_UDP) return std::make_unique<PCPTestSock>(default_local_ipv6, default_gateway_ipv6, script);
+        return std::unique_ptr<PCPTestSock>();
+    };
+
+    ASSERT_DEBUG_LOG("pcp: Retrying (1)");
+    ASSERT_DEBUG_LOG("pcp: Timeout");
+
+    auto res = PCPRequestPortMap(TEST_NONCE, default_gateway_ipv6, default_local_ipv6, 1234, 1000, 2, 2000ms);
+
+    BOOST_CHECK(std::get_if<MappingResult>(&res));
+}
+
+// PCP IPv4 failure (no resources).
+BOOST_AUTO_TEST_CASE(pcp_ipv4_fail_no_resources)
+{
+    const std::vector<TestOp> script{
+        {
+            0ms, TestOp::SEND,
+            {
+                0x02, 0x01, 0x00, 0x00, // version, opcode
+                0x00, 0x00, 0x03, 0xe8, // lifetime
+                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xc0, 0xa8, 0x00, 0x06, // internal IP
+                0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, // nonce
+                0x06, 0x00, 0x00, 0x00, // protocol (TCP), reserved
+                0x04, 0xd2, 0x04, 0xd2, // internal port, suggested external port
+                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00, // suggested external IP
+            }, 0
+        },
+        {
+            500ms, TestOp::RECV,
+            {
+                0x02, 0x81, 0x00, 0x08, // version, opcode, result 0x08: no resources
+                0x00, 0x00, 0x00, 0x00, // granted lifetime
+                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // reserved
+                0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, // nonce
+                0x06, 0x00, 0x00, 0x00, // protocol (TCP), reserved
+                0x04, 0xd2, 0x00, 0x00, // internal port, assigned external port
+                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // assigned external IP
+            }, 0
+        },
+    };
+    CreateSock = [this, &script](int domain, int type, int protocol) {
+        if (domain == AF_INET && type == SOCK_DGRAM && protocol == IPPROTO_UDP) return std::make_unique<PCPTestSock>(default_local_ipv4, default_gateway_ipv4, script);
+        return std::unique_ptr<PCPTestSock>();
+    };
+
+    auto res = PCPRequestPortMap(TEST_NONCE, default_gateway_ipv4, bind_any_ipv4, 1234, 1000, 3, 1000ms);
+
+    MappingError* err = std::get_if<MappingError>(&res);
+    BOOST_REQUIRE(err);
+    BOOST_CHECK_EQUAL(*err, MappingError::NO_RESOURCES);
+}
+
+// PCP IPv4 failure (test NATPMP downgrade scenario).
+BOOST_AUTO_TEST_CASE(pcp_ipv4_fail_unsupported_version)
+{
+    const std::vector<TestOp> script{
+        {
+            0ms, TestOp::SEND,
+            {
+                0x02, 0x01, 0x00, 0x00, // version, opcode
+                0x00, 0x00, 0x03, 0xe8, // lifetime
+                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xc0, 0xa8, 0x00, 0x06, // internal IP
+                0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, // nonce
+                0x06, 0x00, 0x00, 0x00, // protocol (TCP), reserved
+                0x04, 0xd2, 0x04, 0xd2, // internal port, suggested external port
+                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00, // suggested external IP
+            }, 0
+        },
+        {
+            500ms, TestOp::RECV,
+            {
+                0x00, 0x81, 0x00, 0x01, // version, opcode, result 0x01: unsupported version
+                0x00, 0x00, 0x00, 0x00,
+            }, 0
+        },
+    };
+    CreateSock = [this, &script](int domain, int type, int protocol) {
+        if (domain == AF_INET && type == SOCK_DGRAM && protocol == IPPROTO_UDP) return std::make_unique<PCPTestSock>(default_local_ipv4, default_gateway_ipv4, script);
+        return std::unique_ptr<PCPTestSock>();
+    };
+
+    auto res = PCPRequestPortMap(TEST_NONCE, default_gateway_ipv4, bind_any_ipv4, 1234, 1000, 3, 1000ms);
+
+    MappingError* err = std::get_if<MappingError>(&res);
+    BOOST_REQUIRE(err);
+    BOOST_CHECK_EQUAL(*err, MappingError::UNSUPP_VERSION);
+}
+
+// NAT-PMP IPv4 protocol error scenarii.
+BOOST_AUTO_TEST_CASE(natpmp_protocol_error)
+{
+    // First scenario: non-0 result code when requesting external IP.
+    std::vector<TestOp> script{
+        {
+            0ms, TestOp::SEND,
+            {
+                0x00, 0x00, // version, opcode (request external IP)
+            }, 0
+        },
+        {
+            2ms, TestOp::RECV,
+            {
+                0x00, 0x80, 0x00, 0x42, // version, opcode (external IP), result code (*NOT* success)
+                0x66, 0xfd, 0xa1, 0xee, // seconds sinds start of epoch
+                0x01, 0x02, 0x03, 0x04, // external IP address
+            }, 0
+        },
+    };
+    CreateSock = [this, &script](int domain, int type, int protocol) {
+        if (domain == AF_INET && type == SOCK_DGRAM && protocol == IPPROTO_UDP) return std::make_unique<PCPTestSock>(default_local_ipv4, default_gateway_ipv4, script);
+        return std::unique_ptr<PCPTestSock>();
+    };
+
+    auto res = NATPMPRequestPortMap(default_gateway_ipv4, 1234, 1000, 1, 200ms);
+
+    MappingError* err = std::get_if<MappingError>(&res);
+    BOOST_REQUIRE(err);
+    BOOST_CHECK_EQUAL(*err, MappingError::PROTOCOL_ERROR);
+
+    // First scenario: non-0 result code when requesting port mapping.
+    script = {
+        {
+            0ms, TestOp::SEND,
+            {
+                0x00, 0x00, // version, opcode (request external IP)
+            }, 0
+        },
+        {
+            2ms, TestOp::RECV,
+            {
+                0x00, 0x80, 0x00, 0x00, // version, opcode (external IP), result code (success)
+                0x66, 0xfd, 0xa1, 0xee, // seconds sinds start of epoch
+                0x01, 0x02, 0x03, 0x04, // external IP address
+            }, 0
+        },
+        {
+            0ms, TestOp::SEND,
+            {
+                0x00, 0x02, 0x00, 0x00, // version, opcode (request map TCP)
+                0x04, 0xd2, 0x04, 0xd2, // internal port, suggested external port
+                0x00, 0x00, 0x03, 0xe8, // requested mapping lifetime in seconds
+            }, 0
+        },
+        {
+            2ms, TestOp::RECV,
+            {
+                0x00, 0x82, 0x00, 0x43, // version, opcode (mapped TCP)
+                0x66, 0xfd, 0xa1, 0xee, // seconds sinds start of epoch
+                0x04, 0xd2, 0x04, 0xd2, // internal port, mapped external port
+                0x00, 0x00, 0x01, 0xf4, // mapping lifetime in seconds
+            }, 0
+        },
+    };
+    CreateSock = [this, &script](int domain, int type, int protocol) {
+        if (domain == AF_INET && type == SOCK_DGRAM && protocol == IPPROTO_UDP) return std::make_unique<PCPTestSock>(default_local_ipv4, default_gateway_ipv4, script);
+        return std::unique_ptr<PCPTestSock>();
+    };
+
+    res = NATPMPRequestPortMap(default_gateway_ipv4, 1234, 1000, 1, 200ms);
+
+    err = std::get_if<MappingError>(&res);
+    BOOST_REQUIRE(err);
+    BOOST_CHECK_EQUAL(*err, MappingError::PROTOCOL_ERROR);
+}
+
+// PCP IPv4 protocol error scenario.
+BOOST_AUTO_TEST_CASE(pcp_protocol_error)
+{
+    const std::vector<TestOp> script{
+        {
+            0ms, TestOp::SEND,
+            {
+                0x02, 0x01, 0x00, 0x00, // version, opcode
+                0x00, 0x00, 0x03, 0xe8, // lifetime
+                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xc0, 0xa8, 0x00, 0x06, // internal IP
+                0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, // nonce
+                0x06, 0x00, 0x00, 0x00, // protocol (TCP), reserved
+                0x04, 0xd2, 0x04, 0xd2, // internal port, suggested external port
+                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00, // suggested external IP
+            }, 0
+        },
+        {
+            250ms, TestOp::RECV, // 250ms delay before answer
+            {
+                0x02, 0x81, 0x00, 0x42, // version, opcode, result error
+                0x00, 0x00, 0x01, 0xf4, // granted lifetime
+                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // reserved
+                0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, // nonce
+                0x06, 0x00, 0x00, 0x00, // protocol (TCP), reserved
+                0x04, 0xd2, 0x04, 0xd2, // internal port, assigned external port
+                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0x01, 0x02, 0x03, 0x04, // assigned external IP
+            }, 0
+        },
+    };
+    CreateSock = [this, &script](int domain, int type, int protocol) {
+        if (domain == AF_INET && type == SOCK_DGRAM && protocol == IPPROTO_UDP) return std::make_unique<PCPTestSock>(default_local_ipv4, default_gateway_ipv4, script);
+        return std::unique_ptr<PCPTestSock>();
+    };
+
+    auto res = PCPRequestPortMap(TEST_NONCE, default_gateway_ipv4, bind_any_ipv4, 1234, 1000, 1, 1000ms);
+
+    MappingError* err = std::get_if<MappingError>(&res);
+    BOOST_REQUIRE(err);
+    BOOST_CHECK_EQUAL(*err, MappingError::PROTOCOL_ERROR);
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+

src/util/time.cpp

@@ -21,6 +21,7 @@ void UninterruptibleSleep(const std::chrono::microseconds& n) { std::this_thread
 
 static std::atomic<std::chrono::seconds> g_mock_time{}; //!< For testing
 std::atomic<bool> g_used_system_time{false};
+static std::atomic<std::chrono::milliseconds> g_mock_steady_time{}; //!< For testing
 
 NodeClock::time_point NodeClock::now() noexcept
 {
@@ -48,6 +49,30 @@ std::chrono::seconds GetMockTime()
     return g_mock_time.load(std::memory_order_relaxed);
 }
 
+MockableSteadyClock::time_point MockableSteadyClock::now() noexcept
+{
+    const auto mocktime{g_mock_steady_time.load(std::memory_order_relaxed)};
+    if (!mocktime.count()) {
+        g_used_system_time = true;
+    }
+    const auto ret{
+        mocktime.count() ?
+            mocktime :
+            std::chrono::steady_clock::now().time_since_epoch()};
+    return time_point{ret};
+};
+
+void MockableSteadyClock::SetMockTime(std::chrono::milliseconds mock_time_in)
+{
+    Assert(mock_time_in >= 0s);
+    g_mock_steady_time.store(mock_time_in, std::memory_order_relaxed);
+}
+
+void MockableSteadyClock::ClearMockTime()
+{
+    g_mock_steady_time.store(0ms, std::memory_order_relaxed);
+}
+
 int64_t GetTime() { return GetTime<std::chrono::seconds>().count(); }
 
 std::string FormatISO8601DateTime(int64_t nTime)

src/util/time.h

@@ -31,6 +31,31 @@ using SteadyMicroseconds = std::chrono::time_point<std::chrono::steady_clock, st
 
 using SystemClock = std::chrono::system_clock;
 
+/**
+ * Version of SteadyClock that is mockable in the context of tests (set the
+ * current value with SetMockTime), otherwise the system steady clock.
+ */
+struct MockableSteadyClock : public std::chrono::steady_clock {
+    using time_point = std::chrono::time_point<MockableSteadyClock>;
+
+    static constexpr std::chrono::milliseconds INITIAL_MOCK_TIME{1};
+
+    /** Return current system time or mocked time, if set */
+    static time_point now() noexcept;
+    static std::time_t to_time_t(const time_point&) = delete; // unused
+    static time_point from_time_t(std::time_t) = delete;      // unused
+
+    /** Set mock time for testing.
+     * When mocking the steady clock, start at INITIAL_MOCK_TIME and add durations to elapse time as necessary
+     * for testing.
+     * To stop mocking, call ClearMockTime().
+     */
+    static void SetMockTime(std::chrono::milliseconds mock_time_in);
+
+    /** Clear mock time, go back to system steady clock. */
+    static void ClearMockTime();
+};
+
 void UninterruptibleSleep(const std::chrono::microseconds& n);
 
 /**