From 29ae1c13a59187119f5b2a38b54dbbec936d8f87 Mon Sep 17 00:00:00 2001 From: Vasil Dimov Date: Wed, 7 Apr 2021 10:18:39 +0200 Subject: fuzz: split FuzzedSock interface and implementation Move the `FuzzedSock`'s implementation from `src/test/fuzz/util.h` to `src/test/fuzz/util.cpp`. A separate interface and implementation make the code more readable for consumers who don't need to (better not) know the implementation details. --- src/test/fuzz/util.cpp | 173 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 173 insertions(+) (limited to 'src/test/fuzz/util.cpp') diff --git a/src/test/fuzz/util.cpp b/src/test/fuzz/util.cpp index d16c5afac7..f772bc01d8 100644 --- a/src/test/fuzz/util.cpp +++ b/src/test/fuzz/util.cpp @@ -7,6 +7,170 @@ #include #include +FuzzedSock::FuzzedSock(FuzzedDataProvider& fuzzed_data_provider) + : m_fuzzed_data_provider{fuzzed_data_provider} +{ + m_socket = fuzzed_data_provider.ConsumeIntegralInRange(INVALID_SOCKET - 1, INVALID_SOCKET); +} + +FuzzedSock::~FuzzedSock() +{ + // Sock::~Sock() will be called after FuzzedSock::~FuzzedSock() and it will call + // Sock::Reset() (not FuzzedSock::Reset()!) which will call CloseSocket(m_socket). + // Avoid closing an arbitrary file descriptor (m_socket is just a random very high number which + // theoretically may concide with a real opened file descriptor). + Reset(); +} + +FuzzedSock& FuzzedSock::operator=(Sock&& other) +{ + assert(false && "Move of Sock into FuzzedSock not allowed."); + return *this; +} + +void FuzzedSock::Reset() +{ + m_socket = INVALID_SOCKET; +} + +ssize_t FuzzedSock::Send(const void* data, size_t len, int flags) const +{ + constexpr std::array send_errnos{ + EACCES, + EAGAIN, + EALREADY, + EBADF, + ECONNRESET, + EDESTADDRREQ, + EFAULT, + EINTR, + EINVAL, + EISCONN, + EMSGSIZE, + ENOBUFS, + ENOMEM, + ENOTCONN, + ENOTSOCK, + EOPNOTSUPP, + EPIPE, + EWOULDBLOCK, + }; + if (m_fuzzed_data_provider.ConsumeBool()) { + return len; + } + const ssize_t r = m_fuzzed_data_provider.ConsumeIntegralInRange(-1, len); + if (r == -1) { + SetFuzzedErrNo(m_fuzzed_data_provider, send_errnos); + } + return r; +} + +ssize_t FuzzedSock::Recv(void* buf, size_t len, int flags) const +{ + // Have a permanent error at recv_errnos[0] because when the fuzzed data is exhausted + // SetFuzzedErrNo() will always return the first element and we want to avoid Recv() + // returning -1 and setting errno to EAGAIN repeatedly. + constexpr std::array recv_errnos{ + ECONNREFUSED, + EAGAIN, + EBADF, + EFAULT, + EINTR, + EINVAL, + ENOMEM, + ENOTCONN, + ENOTSOCK, + EWOULDBLOCK, + }; + assert(buf != nullptr || len == 0); + if (len == 0 || m_fuzzed_data_provider.ConsumeBool()) { + const ssize_t r = m_fuzzed_data_provider.ConsumeBool() ? 0 : -1; + if (r == -1) { + SetFuzzedErrNo(m_fuzzed_data_provider, recv_errnos); + } + return r; + } + std::vector random_bytes; + bool pad_to_len_bytes{m_fuzzed_data_provider.ConsumeBool()}; + if (m_peek_data.has_value()) { + // `MSG_PEEK` was used in the preceding `Recv()` call, return `m_peek_data`. + random_bytes.assign({m_peek_data.value()}); + if ((flags & MSG_PEEK) == 0) { + m_peek_data.reset(); + } + pad_to_len_bytes = false; + } else if ((flags & MSG_PEEK) != 0) { + // New call with `MSG_PEEK`. + random_bytes = m_fuzzed_data_provider.ConsumeBytes(1); + if (!random_bytes.empty()) { + m_peek_data = random_bytes[0]; + pad_to_len_bytes = false; + } + } else { + random_bytes = m_fuzzed_data_provider.ConsumeBytes( + m_fuzzed_data_provider.ConsumeIntegralInRange(0, len)); + } + if (random_bytes.empty()) { + const ssize_t r = m_fuzzed_data_provider.ConsumeBool() ? 0 : -1; + if (r == -1) { + SetFuzzedErrNo(m_fuzzed_data_provider, recv_errnos); + } + return r; + } + std::memcpy(buf, random_bytes.data(), random_bytes.size()); + if (pad_to_len_bytes) { + if (len > random_bytes.size()) { + std::memset((char*)buf + random_bytes.size(), 0, len - random_bytes.size()); + } + return len; + } + if (m_fuzzed_data_provider.ConsumeBool() && std::getenv("FUZZED_SOCKET_FAKE_LATENCY") != nullptr) { + std::this_thread::sleep_for(std::chrono::milliseconds{2}); + } + return random_bytes.size(); +} + +int FuzzedSock::Connect(const sockaddr*, socklen_t) const +{ + // Have a permanent error at connect_errnos[0] because when the fuzzed data is exhausted + // SetFuzzedErrNo() will always return the first element and we want to avoid Connect() + // returning -1 and setting errno to EAGAIN repeatedly. + constexpr std::array connect_errnos{ + ECONNREFUSED, + EAGAIN, + ECONNRESET, + EHOSTUNREACH, + EINPROGRESS, + EINTR, + ENETUNREACH, + ETIMEDOUT, + }; + if (m_fuzzed_data_provider.ConsumeBool()) { + SetFuzzedErrNo(m_fuzzed_data_provider, connect_errnos); + return -1; + } + return 0; +} + +int FuzzedSock::GetSockOpt(int level, int opt_name, void* opt_val, socklen_t* opt_len) const +{ + constexpr std::array getsockopt_errnos{ + ENOMEM, + ENOBUFS, + }; + if (m_fuzzed_data_provider.ConsumeBool()) { + SetFuzzedErrNo(m_fuzzed_data_provider, getsockopt_errnos); + return -1; + } + if (opt_val == nullptr) { + return 0; + } + std::memcpy(opt_val, + ConsumeFixedLengthByteVector(m_fuzzed_data_provider, *opt_len).data(), + *opt_len); + return 0; +} + bool FuzzedSock::Wait(std::chrono::milliseconds timeout, Event requested, Event* occurred) const { constexpr std::array wait_errnos{ @@ -24,6 +188,15 @@ bool FuzzedSock::Wait(std::chrono::milliseconds timeout, Event requested, Event* return true; } +bool FuzzedSock::IsConnected(std::string& errmsg) const +{ + if (m_fuzzed_data_provider.ConsumeBool()) { + return true; + } + errmsg = "disconnected at random by the fuzzer"; + return false; +} + void FillNode(FuzzedDataProvider& fuzzed_data_provider, CNode& node, bool init_version) noexcept { const ServiceFlags remote_services = ConsumeWeakEnum(fuzzed_data_provider, ALL_SERVICE_FLAGS); -- cgit v1.2.3