1 /* 2 * Copyright (C) 2016 The Android Open Source Project 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in 12 * the documentation and/or other materials provided with the 13 * distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include "tcp.h" 30 31 #include <android-base/parseint.h> 32 #include <android-base/stringprintf.h> 33 34 namespace tcp { 35 36 static constexpr int kProtocolVersion = 1; 37 static constexpr size_t kHandshakeLength = 4; 38 static constexpr int kHandshakeTimeoutMs = 2000; 39 40 // Extract the big-endian 8-byte message length into a 64-bit number. 41 static uint64_t ExtractMessageLength(const void* buffer) { 42 uint64_t ret = 0; 43 for (int i = 0; i < 8; ++i) { 44 ret |= uint64_t{reinterpret_cast<const uint8_t*>(buffer)[i]} << (56 - i * 8); 45 } 46 return ret; 47 } 48 49 // Encode the 64-bit number into a big-endian 8-byte message length. 50 static void EncodeMessageLength(uint64_t length, void* buffer) { 51 for (int i = 0; i < 8; ++i) { 52 reinterpret_cast<uint8_t*>(buffer)[i] = length >> (56 - i * 8); 53 } 54 } 55 56 class TcpTransport : public Transport { 57 public: 58 // Factory function so we can return nullptr if initialization fails. 59 static std::unique_ptr<TcpTransport> NewTransport(std::unique_ptr<Socket> socket, 60 std::string* error); 61 62 ~TcpTransport() override = default; 63 64 ssize_t Read(void* data, size_t length) override; 65 ssize_t Write(const void* data, size_t length) override; 66 int Close() override; 67 68 private: 69 explicit TcpTransport(std::unique_ptr<Socket> sock) : socket_(std::move(sock)) {} 70 71 // Connects to the device and performs the initial handshake. Returns false and fills |error| 72 // on failure. 73 bool InitializeProtocol(std::string* error); 74 75 std::unique_ptr<Socket> socket_; 76 uint64_t message_bytes_left_ = 0; 77 78 DISALLOW_COPY_AND_ASSIGN(TcpTransport); 79 }; 80 81 std::unique_ptr<TcpTransport> TcpTransport::NewTransport(std::unique_ptr<Socket> socket, 82 std::string* error) { 83 std::unique_ptr<TcpTransport> transport(new TcpTransport(std::move(socket))); 84 85 if (!transport->InitializeProtocol(error)) { 86 return nullptr; 87 } 88 89 return transport; 90 } 91 92 // These error strings are checked in tcp_test.cpp and should be kept in sync. 93 bool TcpTransport::InitializeProtocol(std::string* error) { 94 std::string handshake_message(android::base::StringPrintf("FB%02d", kProtocolVersion)); 95 96 if (!socket_->Send(handshake_message.c_str(), kHandshakeLength)) { 97 *error = android::base::StringPrintf("Failed to send initialization message (%s)", 98 Socket::GetErrorMessage().c_str()); 99 return false; 100 } 101 102 char buffer[kHandshakeLength + 1]; 103 buffer[kHandshakeLength] = '\0'; 104 if (socket_->ReceiveAll(buffer, kHandshakeLength, kHandshakeTimeoutMs) != kHandshakeLength) { 105 *error = android::base::StringPrintf( 106 "No initialization message received (%s). Target may not support TCP fastboot", 107 Socket::GetErrorMessage().c_str()); 108 return false; 109 } 110 111 if (memcmp(buffer, "FB", 2) != 0) { 112 *error = "Unrecognized initialization message. Target may not support TCP fastboot"; 113 return false; 114 } 115 116 int version = 0; 117 if (!android::base::ParseInt(buffer + 2, &version) || version < kProtocolVersion) { 118 *error = android::base::StringPrintf("Unknown TCP protocol version %s (host version %02d)", 119 buffer + 2, kProtocolVersion); 120 return false; 121 } 122 123 error->clear(); 124 return true; 125 } 126 127 ssize_t TcpTransport::Read(void* data, size_t length) { 128 if (socket_ == nullptr) { 129 return -1; 130 } 131 132 // Unless we're mid-message, read the next 8-byte message length. 133 if (message_bytes_left_ == 0) { 134 char buffer[8]; 135 if (socket_->ReceiveAll(buffer, 8, 0) != 8) { 136 Close(); 137 return -1; 138 } 139 message_bytes_left_ = ExtractMessageLength(buffer); 140 } 141 142 // Now read the message (up to |length| bytes). 143 if (length > message_bytes_left_) { 144 length = message_bytes_left_; 145 } 146 ssize_t bytes_read = socket_->ReceiveAll(data, length, 0); 147 if (bytes_read == -1) { 148 Close(); 149 } else { 150 message_bytes_left_ -= bytes_read; 151 } 152 return bytes_read; 153 } 154 155 ssize_t TcpTransport::Write(const void* data, size_t length) { 156 if (socket_ == nullptr) { 157 return -1; 158 } 159 160 // Use multi-buffer writes for better performance. 161 char header[8]; 162 EncodeMessageLength(length, header); 163 if (!socket_->Send(std::vector<cutils_socket_buffer_t>{{header, 8}, {data, length}})) { 164 Close(); 165 return -1; 166 } 167 168 return length; 169 } 170 171 int TcpTransport::Close() { 172 if (socket_ == nullptr) { 173 return 0; 174 } 175 176 int result = socket_->Close(); 177 socket_.reset(); 178 return result; 179 } 180 181 std::unique_ptr<Transport> Connect(const std::string& hostname, int port, std::string* error) { 182 return internal::Connect(Socket::NewClient(Socket::Protocol::kTcp, hostname, port, error), 183 error); 184 } 185 186 namespace internal { 187 188 std::unique_ptr<Transport> Connect(std::unique_ptr<Socket> sock, std::string* error) { 189 if (sock == nullptr) { 190 // If Socket creation failed |error| is already set. 191 return nullptr; 192 } 193 194 return TcpTransport::NewTransport(std::move(sock), error); 195 } 196 197 } // namespace internal 198 199 } // namespace tcp 200
