/*
 * Copyright (c) 2020 The Regents of the University of California
 * 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;
 * neither the name of the copyright holders nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * 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 <gtest/gtest.h>

#include <cstring>
#include <sstream>
#include <utility>

#include "base/gtest/logging.hh"
#include "base/socket.hh"

static const int TestPort1 = 7893;
static const int TestPort2 = 7894;

using namespace gem5;

/*
 * Socket.test tests socket.cc. It should be noted that some features of
 * socket.cc have not been fully tested due to interaction with system-calls.
 */

namespace {

std::string
repeat(const std::string& str, size_t n)
{
    std::stringstream ss;
    for (int i = 0; i < n; ++i) {
        ss << str;
    }
    return ss.str();
}

} // namespace

TEST(UnixSocketAddrTest, AbstractSocket)
{
    UnixSocketAddr sock_addr = UnixSocketAddr::build("@abstract");
    EXPECT_EQ(AF_UNIX, sock_addr.addr.sun_family);
    // null byte will not show, so compare from the first byte
    EXPECT_STREQ("abstract", sock_addr.addr.sun_path + 1);
    EXPECT_TRUE(sock_addr.isAbstract);
    EXPECT_STREQ("@abstract", sock_addr.formattedPath.c_str());
}

TEST(UnixSocketAddrTest, TruncatedAbstractSocket)
{
    // Test that address is truncated if longer than sizeof(sun_path)
    constexpr size_t MaxSize = sizeof(std::declval<sockaddr_un>().sun_path);

    // >sizeof(sun_path) bytes
    std::string addr = "@" + repeat("123456789", 100);
    ASSERT_GT(addr.size(), MaxSize);
    std::string truncated_addr = addr.substr(0, MaxSize);

    UnixSocketAddr sock_addr = UnixSocketAddr::build(addr);
    EXPECT_EQ(AF_UNIX, sock_addr.addr.sun_family);
    // Use memcmp so that we can compare null bytes as well
    std::string null_formatted = '\0' + truncated_addr.substr(1);
    EXPECT_EQ(0, std::memcmp(null_formatted.c_str(), sock_addr.addr.sun_path,
                             MaxSize));
    EXPECT_TRUE(sock_addr.isAbstract);
    EXPECT_EQ(truncated_addr, sock_addr.formattedPath);
}

TEST(UnixSocketAddrTest, FileBasedSocket)
{
    std::string addr = "/home/parent/dir/x";
    UnixSocketAddr sock_addr = UnixSocketAddr::build(addr);
    EXPECT_EQ(AF_UNIX, sock_addr.addr.sun_family);
    EXPECT_STREQ(addr.c_str(), sock_addr.addr.sun_path);
    EXPECT_FALSE(sock_addr.isAbstract);
    EXPECT_EQ(addr, sock_addr.formattedPath);
}

TEST(UnixSocketAddrTest, TruncatedFileBasedSocket)
{
    // sun_path should null terminate, so test that address is truncated if
    // longer than sizeof(sun_path) - 1 bytes.
    constexpr size_t MaxSize =
        sizeof(std::declval<sockaddr_un>().sun_path) - 1;

    // >sizeof(sun_path) - 1 bytes
    std::string addr = "/" + repeat("123456789", 100);
    ASSERT_GT(addr.size(), MaxSize);
    std::string truncated_addr = addr.substr(0, MaxSize);

    UnixSocketAddr sock_addr = UnixSocketAddr::build(addr);
    EXPECT_EQ(AF_UNIX, sock_addr.addr.sun_family);
    EXPECT_STREQ(truncated_addr.c_str(), sock_addr.addr.sun_path);
    EXPECT_FALSE(sock_addr.isAbstract);
    EXPECT_EQ(truncated_addr, sock_addr.formattedPath);
}

class MockListenSocket : public ListenSocketInet
{
  public:
    MockListenSocket(int port) : ListenSocketInet("mock", port) {}
    /*
     * This mock Listen Socket is used to ensure the static variables are reset
     * back to their default values after deconstruction (i.e., after a test
     * has completed).
     */
    ~MockListenSocket()
    {
        cleanup();
    }
};

TEST(SocketTest, DefaultBehavior)
{
    /*
     * Tests the default behavior where listenSocket is constructed, and is
     * not listening to a port.
     */
    MockListenSocket listen_socket(-1);
    EXPECT_EQ(-1, listen_socket.getfd());
    EXPECT_FALSE(listen_socket.islistening());
    EXPECT_FALSE(listen_socket.allDisabled());
}

TEST(SocketTest, DisableAll)
{
    MockListenSocket listen_socket(-1);
    listen_socket.disableAll();
    EXPECT_EQ(-1, listen_socket.getfd());
    EXPECT_FALSE(listen_socket.islistening());
    EXPECT_TRUE(listen_socket.allDisabled());
}

TEST(SocketTest, ListenToPort)
{
    MockListenSocket listen_socket(TestPort1);
    listen_socket.listen();
    EXPECT_NE(-1, listen_socket.getfd());
    EXPECT_TRUE(listen_socket.islistening());
    EXPECT_FALSE(listen_socket.allDisabled());
}

TEST(SocketTest, RelistenWithSameInstanceSamePort)
{
    MockListenSocket listen_socket(TestPort1);
    listen_socket.listen();

    /*
     * You cannot listen to another port if you are already listening to one.
     */
    gtestLogOutput.str("");
    EXPECT_ANY_THROW(listen_socket.listen());
    std::string expected =
        "panic: panic condition listening occurred: "
        "Socket already listening!\n";
    std::string actual = gtestLogOutput.str();
    EXPECT_EQ(expected, actual);
}

TEST(SocketTest, RelistenWithDifferentInstanceOnDifferentPort)
{
    MockListenSocket listen_socket(TestPort1);
    listen_socket.listen();

    /*
     * You can listen to another port with a different instance.
     */
    MockListenSocket listen_socket_2(TestPort2);
    listen_socket_2.listen();
}

TEST(SocketTest, RelistenWithDifferentInstanceOnSamePort)
{
    MockListenSocket listen_socket(TestPort1);
    listen_socket.listen();

    /*
     * You cannot listen to a port that's already being listened to.
     */
    MockListenSocket listen_socket_2(TestPort1);
    listen_socket_2.listen();
}

TEST(SocketTest, AcceptError)
{
    MockListenSocket listen_socket(-1);
    EXPECT_ANY_THROW(listen_socket.accept());
    std::string expected =
        "panic: panic condition sfd == -1 occurred: mock: Failed to accept "
        "connection: Bad file descriptor\n";
    std::string actual = gtestLogOutput.str();
    EXPECT_EQ(expected, actual);
}