fastboot: socket testing improvements.

(This code was originally part of a huge fastboot CL but has been split
out to try to make the CLs a little more manageable).

More prep for fastboot TCP and UDP implementations. This CL adds a
SocketMock class that makes it easy to mock out network behavior so we
can unit test the TCP and UDP protocols.

Also uses the new libcutils socket_get_local_port() to avoid hardcoding
a server port in unit tests.

Bug: http://b/26157893.
Change-Id: I1ba10f31e98d7349313fc15f240383d63378a8db

1 files changed, 132 insertions, 0 deletions

diff --git a/fastboot/socket_mock.cpp b/fastboot/socket_mock.cpp
new file mode 100644
index 000000000..8fea55466
--- /dev/null
+++ b/fastboot/socket_mock.cpp
@@ -0,0 +1,132 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "socket_mock.h"
+
+#include <gtest/gtest.h>
+
+SocketMock::SocketMock() : Socket(INVALID_SOCKET) {}
+
+SocketMock::~SocketMock() {
+    if (!events_.empty()) {
+        ADD_FAILURE() << events_.size() << " event(s) were not handled";
+    }
+}
+
+ssize_t SocketMock::Send(const void* data, size_t length) {
+    if (events_.empty()) {
+        ADD_FAILURE() << "Send() was called when no message was expected";
+        return -1;
+    }
+
+    if (events_.front().type != EventType::kSend) {
+        ADD_FAILURE() << "Send() was called out-of-order";
+        return -1;
+    }
+
+    std::string message(reinterpret_cast<const char*>(data), length);
+    if (events_.front().message != message) {
+        ADD_FAILURE() << "Send() expected " << events_.front().message << ", but got " << message;
+        return -1;
+    }
+
+    ssize_t return_value = events_.front().return_value;
+    events_.pop();
+    return return_value;
+}
+
+ssize_t SocketMock::Receive(void* data, size_t length, int /*timeout_ms*/) {
+    if (events_.empty()) {
+        ADD_FAILURE() << "Receive() was called when no message was ready";
+        return -1;
+    }
+
+    if (events_.front().type != EventType::kReceive) {
+        ADD_FAILURE() << "Receive() was called out-of-order";
+        return -1;
+    }
+
+    if (events_.front().return_value > static_cast<ssize_t>(length)) {
+        ADD_FAILURE() << "Receive(): not enough bytes (" << length << ") for "
+                      << events_.front().message;
+        return -1;
+    }
+
+    ssize_t return_value = events_.front().return_value;
+    if (return_value > 0) {
+        memcpy(data, events_.front().message.data(), return_value);
+    }
+    events_.pop();
+    return return_value;
+}
+
+int SocketMock::Close() {
+    return 0;
+}
+
+std::unique_ptr<Socket> SocketMock::Accept() {
+    if (events_.empty()) {
+        ADD_FAILURE() << "Accept() was called when no socket was ready";
+        return nullptr;
+    }
+
+    if (events_.front().type != EventType::kAccept) {
+        ADD_FAILURE() << "Accept() was called out-of-order";
+        return nullptr;
+    }
+
+    std::unique_ptr<Socket> sock = std::move(events_.front().sock);
+    events_.pop();
+    return sock;
+}
+
+void SocketMock::ExpectSend(std::string message) {
+    ssize_t return_value = message.length();
+    events_.push(Event(EventType::kSend, std::move(message), return_value, nullptr));
+}
+
+void SocketMock::ExpectSendFailure(std::string message) {
+    events_.push(Event(EventType::kSend, std::move(message), -1, nullptr));
+}
+
+void SocketMock::AddReceive(std::string message) {
+    ssize_t return_value = message.length();
+    events_.push(Event(EventType::kReceive, std::move(message), return_value, nullptr));
+}
+
+void SocketMock::AddReceiveFailure() {
+    events_.push(Event(EventType::kReceive, "", -1, nullptr));
+}
+
+void SocketMock::AddAccept(std::unique_ptr<Socket> sock) {
+    events_.push(Event(EventType::kAccept, "", 0, std::move(sock)));
+}
+
+SocketMock::Event::Event(EventType _type, std::string _message, ssize_t _return_value,
+                         std::unique_ptr<Socket> _sock)
+        : type(_type), message(_message), return_value(_return_value), sock(std::move(_sock)) {}