netlink_manager_unittest.cc

// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// This file provides tests for individual messages.  It tests
// NetlinkMessageFactory's ability to create specific message types and it
// tests the various NetlinkMessage types' ability to parse those
// messages.

// This file tests the public interface to NetlinkManager.
#include "shill/netlink_manager.h"

#include <string>

#include <gmock/gmock.h>
#include <gtest/gtest.h>

#include "shill/mock_netlink_socket.h"
#include "shill/mock_sockets.h"
#include "shill/mock_time.h"
#include "shill/netlink_attribute.h"
#include "shill/nl80211_message.h"

using base::Bind;
using base::Unretained;
using std::string;
using testing::_;
using testing::Invoke;
using testing::Return;
using testing::Test;

namespace shill {

namespace {

// These data blocks have been collected by shill using NetlinkManager while,
// simultaneously (and manually) comparing shill output with that of the 'iw'
// code from which it was derived.  The test strings represent the raw packet
// data coming from the kernel.  The comments above each of these strings is
// the markup that "iw" outputs for ech of these packets.

// These constants are consistent throughout the packets, below.

const uint16_t kNl80211FamilyId = 0x13;

// wlan0 (phy #0): disconnected (by AP) reason: 2: Previous authentication no
// longer valid

const unsigned char kNL80211_CMD_DISCONNECT[] = {
  0x30, 0x00, 0x00, 0x00, 0x13, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x30, 0x01, 0x00, 0x00, 0x08, 0x00, 0x01, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x08, 0x00, 0x03, 0x00,
  0x04, 0x00, 0x00, 0x00, 0x06, 0x00, 0x36, 0x00,
  0x02, 0x00, 0x00, 0x00, 0x04, 0x00, 0x47, 0x00,
};

const char kGetFamilyCommandString[] = "CTRL_CMD_GETFAMILY";

}  // namespace

class NetlinkManagerTest : public Test {
 public:
  NetlinkManagerTest()
      : netlink_manager_(NetlinkManager::GetInstance()),
        sockets_(new MockSockets),
        saved_sequence_number_(0) {
    netlink_manager_->message_types_[Nl80211Message::kMessageTypeString]
        .family_id = kNl80211FamilyId;
    netlink_manager_->message_factory_.AddFactoryMethod(
        kNl80211FamilyId, Bind(&Nl80211Message::CreateMessage));
    Nl80211Message::SetMessageType(kNl80211FamilyId);
    // Passes ownership.
    netlink_socket_.sockets_.reset(sockets_);

    EXPECT_NE(reinterpret_cast<NetlinkManager *>(NULL), netlink_manager_);
    netlink_manager_->sock_ = &netlink_socket_;
    EXPECT_TRUE(netlink_manager_->Init());
  }

  ~NetlinkManagerTest() {
    // NetlinkManager is a singleton, the sock_ field *MUST* be cleared
    // before "NetlinkManagerTest::socket_" gets invalidated, otherwise
    // later tests will refer to a corrupted memory.
    netlink_manager_->sock_ = NULL;
  }

  // |SaveReply|, |SendMessage|, and |ReplyToSentMessage| work together to
  // enable a test to get a response to a sent message.  They must be called
  // in the order, above, so that a) a reply message is available to b) have
  // its sequence number replaced, and then c) sent back to the code.
  void SaveReply(const ByteString &message) {
    saved_message_ = message;
  }

  // Replaces the |saved_message_|'s sequence number with the sent value.
  bool SendMessage(const ByteString &outgoing_message) {
    if (outgoing_message.GetLength() < sizeof(nlmsghdr)) {
      LOG(ERROR) << "Outgoing message is too short";
      return false;
    }
    const nlmsghdr *outgoing_header =
        reinterpret_cast<const nlmsghdr *>(outgoing_message.GetConstData());

    if (saved_message_.GetLength() < sizeof(nlmsghdr)) {
      LOG(ERROR) << "Saved message is too short; have you called |SaveReply|?";
      return false;
    }
    nlmsghdr *reply_header =
        reinterpret_cast<nlmsghdr *>(saved_message_.GetData());

    reply_header->nlmsg_seq = outgoing_header->nlmsg_seq;
    saved_sequence_number_ = reply_header->nlmsg_seq;
    return true;
  }

  bool ReplyToSentMessage(ByteString *message) {
    if (!message) {
      return false;
    }
    *message = saved_message_;
    return true;
  }

  bool ReplyWithRandomMessage(ByteString *message) {
    GetFamilyMessage get_family_message;
    // Any number that's not 0 or 1 is acceptable, here.  Zero is bad because
    // we want to make sure that this message is different than the main
    // send/receive pair.  One is bad becasue the default for
    // |saved_sequence_number_| is zero and the likely default value for the
    // first sequence number generated from the code is 1.
    const uint32_t kRandomOffset = 1003;
    if (!message) {
      return false;
    }
    *message = get_family_message.Encode(saved_sequence_number_ +
                                         kRandomOffset);
    return true;
  }

 protected:
  class MockHandler80211 {
   public:
    MockHandler80211() :
      on_netlink_message_(base::Bind(&MockHandler80211::OnNetlinkMessage,
                                     base::Unretained(this))) {}
    MOCK_METHOD1(OnNetlinkMessage, void(const NetlinkMessage &msg));
    const NetlinkManager::NetlinkMessageHandler &on_netlink_message() const {
      return on_netlink_message_;
    }
   private:
    NetlinkManager::NetlinkMessageHandler on_netlink_message_;
    DISALLOW_COPY_AND_ASSIGN(MockHandler80211);
  };

  void Reset() {
    netlink_manager_->Reset(false);
  }

  NetlinkManager *netlink_manager_;
  MockNetlinkSocket netlink_socket_;
  MockSockets *sockets_;  // Owned by |netlink_socket_|.
  ByteString saved_message_;
  uint32_t saved_sequence_number_;
};

namespace {

class TimeFunctor {
 public:
  TimeFunctor(time_t tv_sec, suseconds_t tv_usec) {
    return_value_.tv_sec = tv_sec;
    return_value_.tv_usec = tv_usec;
  }

  TimeFunctor() {
    return_value_.tv_sec = 0;
    return_value_.tv_usec = 0;
  }

  TimeFunctor(const TimeFunctor &other) {
    return_value_.tv_sec = other.return_value_.tv_sec;
    return_value_.tv_usec = other.return_value_.tv_usec;
  }

  TimeFunctor &operator=(const TimeFunctor &rhs) {
    return_value_.tv_sec = rhs.return_value_.tv_sec;
    return_value_.tv_usec = rhs.return_value_.tv_usec;
    return *this;
  }

  // Replaces GetTimeMonotonic.
  int operator()(struct timeval *answer) {
    if (answer) {
      *answer = return_value_;
    }
    return 0;
  }

 private:
  struct timeval return_value_;

  // No DISALLOW_COPY_AND_ASSIGN since testing::Invoke uses copy.
};

}  // namespace

// TODO(wdg): Add a test for multi-part messages.  crbug.com/224652
// TODO(wdg): Add a test for SubscribeToEvents (verify that it handles bad input
// appropriately, and that it calls NetlinkSocket::SubscribeToEvents if input
// is good.)

TEST_F(NetlinkManagerTest, GetFamily) {
  const uint16_t kSampleMessageType = 42;
  const string kSampleMessageName("SampleMessageName");
  const uint32_t kRandomSequenceNumber = 3;

  NewFamilyMessage new_family_message;
  new_family_message.attributes()->CreateAttribute(
      CTRL_ATTR_FAMILY_ID,
      base::Bind(&NetlinkAttribute::NewControlAttributeFromId));
  new_family_message.attributes()->SetU16AttributeValue(
      CTRL_ATTR_FAMILY_ID, kSampleMessageType);
  new_family_message.attributes()->CreateAttribute(
      CTRL_ATTR_FAMILY_NAME,
      base::Bind(&NetlinkAttribute::NewControlAttributeFromId));
  new_family_message.attributes()->SetStringAttributeValue(
      CTRL_ATTR_FAMILY_NAME, kSampleMessageName);

  // The sequence number is immaterial since it'll be overwritten.
  SaveReply(new_family_message.Encode(kRandomSequenceNumber));
  EXPECT_CALL(netlink_socket_, SendMessage(_)).
      WillOnce(Invoke(this, &NetlinkManagerTest::SendMessage));
  EXPECT_CALL(netlink_socket_, file_descriptor()).WillRepeatedly(Return(0));
  EXPECT_CALL(*sockets_, Select(_, _, _, _, _)).WillOnce(Return(1));
  EXPECT_CALL(netlink_socket_, RecvMessage(_)).
      WillOnce(Invoke(this, &NetlinkManagerTest::ReplyToSentMessage));
  NetlinkMessageFactory::FactoryMethod null_factory;
  EXPECT_EQ(kSampleMessageType, netlink_manager_->GetFamily(kSampleMessageName,
                                                            null_factory));
}

TEST_F(NetlinkManagerTest, GetFamilyOneInterstitialMessage) {
  Reset();

  const uint16_t kSampleMessageType = 42;
  const string kSampleMessageName("SampleMessageName");
  const uint32_t kRandomSequenceNumber = 3;

  NewFamilyMessage new_family_message;
  new_family_message.attributes()->CreateAttribute(
      CTRL_ATTR_FAMILY_ID,
      base::Bind(&NetlinkAttribute::NewControlAttributeFromId));
  new_family_message.attributes()->SetU16AttributeValue(
      CTRL_ATTR_FAMILY_ID, kSampleMessageType);
  new_family_message.attributes()->CreateAttribute(
      CTRL_ATTR_FAMILY_NAME,
      base::Bind(&NetlinkAttribute::NewControlAttributeFromId));
  new_family_message.attributes()->SetStringAttributeValue(
      CTRL_ATTR_FAMILY_NAME, kSampleMessageName);

  // The sequence number is immaterial since it'll be overwritten.
  SaveReply(new_family_message.Encode(kRandomSequenceNumber));
  EXPECT_CALL(netlink_socket_, SendMessage(_)).
      WillOnce(Invoke(this, &NetlinkManagerTest::SendMessage));
  EXPECT_CALL(netlink_socket_, file_descriptor()).WillRepeatedly(Return(0));
  EXPECT_CALL(*sockets_, Select(_, _, _, _, _)).WillRepeatedly(Return(1));
  EXPECT_CALL(netlink_socket_, RecvMessage(_)).
      WillOnce(Invoke(this, &NetlinkManagerTest::ReplyWithRandomMessage)).
      WillOnce(Invoke(this, &NetlinkManagerTest::ReplyToSentMessage));
  NetlinkMessageFactory::FactoryMethod null_factory;
  EXPECT_EQ(kSampleMessageType, netlink_manager_->GetFamily(kSampleMessageName,
                                                            null_factory));
}

TEST_F(NetlinkManagerTest, GetFamilyTimeout) {
  Reset();
  MockTime time;
  netlink_manager_->time_ = &time;

  EXPECT_CALL(netlink_socket_, SendMessage(_)).WillOnce(Return(true));
  time_t kStartSeconds = 1234;  // Arbitrary.
  suseconds_t kSmallUsec = 100;
  EXPECT_CALL(time, GetTimeMonotonic(_)).
      WillOnce(Invoke(TimeFunctor(kStartSeconds, 0))).  // Initial time.
      WillOnce(Invoke(TimeFunctor(kStartSeconds, kSmallUsec))).
      WillOnce(Invoke(TimeFunctor(kStartSeconds, 2 * kSmallUsec))).
      WillOnce(Invoke(TimeFunctor(
          kStartSeconds + NetlinkManager::kMaximumNewFamilyWaitSeconds + 1,
          NetlinkManager::kMaximumNewFamilyWaitMicroSeconds)));
  EXPECT_CALL(netlink_socket_, file_descriptor()).WillRepeatedly(Return(0));
  EXPECT_CALL(*sockets_, Select(_, _, _, _, _)).WillRepeatedly(Return(1));
  EXPECT_CALL(netlink_socket_, RecvMessage(_)).
      WillRepeatedly(Invoke(this, &NetlinkManagerTest::ReplyWithRandomMessage));
  NetlinkMessageFactory::FactoryMethod null_factory;

  const string kSampleMessageName("SampleMessageName");
  EXPECT_EQ(NetlinkMessage::kIllegalMessageType,
            netlink_manager_->GetFamily(kSampleMessageName, null_factory));
}

TEST_F(NetlinkManagerTest, BroadcastHandlerTest) {
  nlmsghdr *message = const_cast<nlmsghdr *>(
        reinterpret_cast<const nlmsghdr *>(kNL80211_CMD_DISCONNECT));

  MockHandler80211 handler1;
  MockHandler80211 handler2;

  // Simple, 1 handler, case.
  EXPECT_CALL(handler1, OnNetlinkMessage(_)).Times(1);
  EXPECT_FALSE(
      netlink_manager_->FindBroadcastHandler(handler1.on_netlink_message()));
  netlink_manager_->AddBroadcastHandler(handler1.on_netlink_message());
  EXPECT_TRUE(
      netlink_manager_->FindBroadcastHandler(handler1.on_netlink_message()));
  netlink_manager_->OnNlMessageReceived(message);

  // Add a second handler.
  EXPECT_CALL(handler1, OnNetlinkMessage(_)).Times(1);
  EXPECT_CALL(handler2, OnNetlinkMessage(_)).Times(1);
  netlink_manager_->AddBroadcastHandler(handler2.on_netlink_message());
  netlink_manager_->OnNlMessageReceived(message);

  // Verify that a handler can't be added twice.
  EXPECT_CALL(handler1, OnNetlinkMessage(_)).Times(1);
  EXPECT_CALL(handler2, OnNetlinkMessage(_)).Times(1);
  netlink_manager_->AddBroadcastHandler(handler1.on_netlink_message());
  netlink_manager_->OnNlMessageReceived(message);

  // Check that we can remove a handler.
  EXPECT_CALL(handler1, OnNetlinkMessage(_)).Times(0);
  EXPECT_CALL(handler2, OnNetlinkMessage(_)).Times(1);
  EXPECT_TRUE(netlink_manager_->RemoveBroadcastHandler(
      handler1.on_netlink_message()));
  netlink_manager_->OnNlMessageReceived(message);

  // Check that re-adding the handler goes smoothly.
  EXPECT_CALL(handler1, OnNetlinkMessage(_)).Times(1);
  EXPECT_CALL(handler2, OnNetlinkMessage(_)).Times(1);
  netlink_manager_->AddBroadcastHandler(handler1.on_netlink_message());
  netlink_manager_->OnNlMessageReceived(message);

  // Check that ClearBroadcastHandlers works.
  netlink_manager_->ClearBroadcastHandlers();
  EXPECT_CALL(handler1, OnNetlinkMessage(_)).Times(0);
  EXPECT_CALL(handler2, OnNetlinkMessage(_)).Times(0);
  netlink_manager_->OnNlMessageReceived(message);
}

TEST_F(NetlinkManagerTest, MessageHandlerTest) {
  Reset();
  MockHandler80211 handler_broadcast;
  EXPECT_TRUE(netlink_manager_->AddBroadcastHandler(
      handler_broadcast.on_netlink_message()));

  Nl80211Message sent_message_1(CTRL_CMD_GETFAMILY, kGetFamilyCommandString);
  MockHandler80211 handler_sent_1;

  Nl80211Message sent_message_2(CTRL_CMD_GETFAMILY, kGetFamilyCommandString);
  MockHandler80211 handler_sent_2;

  // Set up the received message as a response to sent_message_1.
  scoped_array<unsigned char> message_memory(
      new unsigned char[sizeof(kNL80211_CMD_DISCONNECT)]);
  memcpy(message_memory.get(), kNL80211_CMD_DISCONNECT,
         sizeof(kNL80211_CMD_DISCONNECT));
  nlmsghdr *received_message =
        reinterpret_cast<nlmsghdr *>(message_memory.get());

  // Now, we can start the actual test...

  // Verify that generic handler gets called for a message when no
  // message-specific handler has been installed.
  EXPECT_CALL(handler_broadcast, OnNetlinkMessage(_)).Times(1);
  netlink_manager_->OnNlMessageReceived(received_message);

  // Send the message and give our handler.  Verify that we get called back.
  EXPECT_CALL(netlink_socket_, SendMessage(_)).WillOnce(Return(true));
  EXPECT_TRUE(netlink_manager_->SendMessage(
      &sent_message_1, handler_sent_1.on_netlink_message()));
  // Make it appear that this message is in response to our sent message.
  received_message->nlmsg_seq = netlink_socket_.GetLastSequenceNumber();
  EXPECT_CALL(handler_sent_1, OnNetlinkMessage(_)).Times(1);
  netlink_manager_->OnNlMessageReceived(received_message);

  // Verify that broadcast handler is called for the message after the
  // message-specific handler is called once.
  EXPECT_CALL(handler_broadcast, OnNetlinkMessage(_)).Times(1);
  netlink_manager_->OnNlMessageReceived(received_message);

  // Install and then uninstall message-specific handler; verify broadcast
  // handler is called on message receipt.
  EXPECT_CALL(netlink_socket_, SendMessage(_)).WillOnce(Return(true));
  EXPECT_TRUE(netlink_manager_->SendMessage(
      &sent_message_1, handler_sent_1.on_netlink_message()));
  received_message->nlmsg_seq = netlink_socket_.GetLastSequenceNumber();
  EXPECT_TRUE(netlink_manager_->RemoveMessageHandler(sent_message_1));
  EXPECT_CALL(handler_broadcast, OnNetlinkMessage(_)).Times(1);
  netlink_manager_->OnNlMessageReceived(received_message);

  // Install handler for different message; verify that broadcast handler is
  // called for _this_ message.
  EXPECT_CALL(netlink_socket_, SendMessage(_)).WillOnce(Return(true));
  EXPECT_TRUE(netlink_manager_->SendMessage(
      &sent_message_2, handler_sent_2.on_netlink_message()));
  EXPECT_CALL(handler_broadcast, OnNetlinkMessage(_)).Times(1);
  netlink_manager_->OnNlMessageReceived(received_message);

  // Change the ID for the message to that of the second handler; verify that
  // the appropriate handler is called for _that_ message.
  received_message->nlmsg_seq = netlink_socket_.GetLastSequenceNumber();
  EXPECT_CALL(handler_sent_2, OnNetlinkMessage(_)).Times(1);
  netlink_manager_->OnNlMessageReceived(received_message);
}

}  // namespace shill