Services/UDS: Added a function to send EAPoL-Start packets (#2920)

* Services/UDS: Added a function to generate the EAPoL-Start packet body.

* Services/UDS: Added filter for beacons.

* Services/UDS: Lock a mutex when accessing connection_status from both the emulation and network thread.

* Services/UDS: Handle the Association Response frame and respond with the EAPoL-Start frame.

* fixup: make use of current_node, changed received_beacons into a list, mutex and assert corrections

* fixup: fix damn clang-format
This commit is contained in:
B3n30 2017-09-25 08:16:27 +02:00 committed by GitHub
parent a81536f53f
commit d673d508dd
5 changed files with 243 additions and 81 deletions

View file

@ -2,8 +2,10 @@
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include <algorithm>
#include <array>
#include <cstring>
#include <list>
#include <mutex>
#include <unordered_map>
#include <vector>
@ -37,9 +39,12 @@ static ConnectionStatus connection_status{};
/* Node information about the current network.
* The amount of elements in this vector is always the maximum number
* of nodes specified in the network configuration.
* The first node is always the host, so this always contains at least 1 entry.
* The first node is always the host.
*/
static NodeList node_info(1);
static NodeList node_info;
// Node information about our own system.
static NodeInfo current_node;
// Mapping of bind node ids to their respective events.
static std::unordered_map<u32, Kernel::SharedPtr<Kernel::Event>> bind_node_events;
@ -54,6 +59,10 @@ static NetworkInfo network_info;
// Event that will generate and send the 802.11 beacon frames.
static int beacon_broadcast_event;
// Mutex to synchronize access to the connection status between the emulation thread and the
// network thread.
static std::mutex connection_status_mutex;
// Mutex to synchronize access to the list of received beacons between the emulation thread and the
// network thread.
static std::mutex beacon_mutex;
@ -63,14 +72,26 @@ static std::mutex beacon_mutex;
constexpr size_t MaxBeaconFrames = 15;
// List of the last <MaxBeaconFrames> beacons received from the network.
static std::deque<Network::WifiPacket> received_beacons;
static std::list<Network::WifiPacket> received_beacons;
/**
* Returns a list of received 802.11 beacon frames from the specified sender since the last call.
*/
std::deque<Network::WifiPacket> GetReceivedBeacons(const MacAddress& sender) {
std::list<Network::WifiPacket> GetReceivedBeacons(const MacAddress& sender) {
std::lock_guard<std::mutex> lock(beacon_mutex);
// TODO(Subv): Filter by sender.
if (sender != Network::BroadcastMac) {
std::list<Network::WifiPacket> filtered_list;
const auto beacon = std::find_if(received_beacons.begin(), received_beacons.end(),
[&sender](const Network::WifiPacket& packet) {
return packet.transmitter_address == sender;
});
if (beacon != received_beacons.end()) {
filtered_list.push_back(*beacon);
// TODO(B3N30): Check if the complete deque is cleared or just the fetched entries
received_beacons.erase(beacon);
}
return filtered_list;
}
return std::move(received_beacons);
}
@ -83,6 +104,15 @@ void SendPacket(Network::WifiPacket& packet) {
// limit is exceeded.
void HandleBeaconFrame(const Network::WifiPacket& packet) {
std::lock_guard<std::mutex> lock(beacon_mutex);
const auto unique_beacon =
std::find_if(received_beacons.begin(), received_beacons.end(),
[&packet](const Network::WifiPacket& new_packet) {
return new_packet.transmitter_address == packet.transmitter_address;
});
if (unique_beacon != received_beacons.end()) {
// We already have a beacon from the same mac in the deque, remove the old one;
received_beacons.erase(unique_beacon);
}
received_beacons.emplace_back(packet);
@ -91,14 +121,33 @@ void HandleBeaconFrame(const Network::WifiPacket& packet) {
received_beacons.pop_front();
}
void HandleAssociationResponseFrame(const Network::WifiPacket& packet) {
auto assoc_result = GetAssociationResult(packet.data);
ASSERT_MSG(std::get<AssocStatus>(assoc_result) == AssocStatus::Successful,
"Could not join network");
{
std::lock_guard<std::mutex> lock(connection_status_mutex);
ASSERT(connection_status.status == static_cast<u32>(NetworkStatus::Connecting));
}
// Send the EAPoL-Start packet to the server.
using Network::WifiPacket;
WifiPacket eapol_start;
eapol_start.channel = network_channel;
eapol_start.data = GenerateEAPoLStartFrame(std::get<u16>(assoc_result), current_node);
// TODO(B3N30): Encrypt the packet.
eapol_start.destination_address = packet.transmitter_address;
eapol_start.type = WifiPacket::PacketType::Data;
SendPacket(eapol_start);
}
/*
* Returns an available index in the nodes array for the
* currently-hosted UDS network.
*/
static u16 GetNextAvailableNodeId() {
ASSERT_MSG(connection_status.status == static_cast<u32>(NetworkStatus::ConnectedAsHost),
"Can not accept clients if we're not hosting a network");
for (u16 index = 0; index < connection_status.max_nodes; ++index) {
if ((connection_status.node_bitmask & (1 << index)) == 0)
return index;
@ -113,27 +162,37 @@ static u16 GetNextAvailableNodeId() {
* authentication frame with SEQ1.
*/
void StartConnectionSequence(const MacAddress& server) {
using Network::WifiPacket;
WifiPacket auth_request;
{
std::lock_guard<std::mutex> lock(connection_status_mutex);
ASSERT(connection_status.status == static_cast<u32>(NetworkStatus::NotConnected));
// TODO(Subv): Handle timeout.
// Send an authentication frame with SEQ1
using Network::WifiPacket;
WifiPacket auth_request;
auth_request.channel = network_channel;
auth_request.data = GenerateAuthenticationFrame(AuthenticationSeq::SEQ1);
auth_request.destination_address = server;
auth_request.type = WifiPacket::PacketType::Authentication;
}
SendPacket(auth_request);
}
/// Sends an Association Response frame to the specified mac address
void SendAssociationResponseFrame(const MacAddress& address) {
ASSERT_MSG(connection_status.status == static_cast<u32>(NetworkStatus::ConnectedAsHost));
using Network::WifiPacket;
WifiPacket assoc_response;
{
std::lock_guard<std::mutex> lock(connection_status_mutex);
if (connection_status.status != static_cast<u32>(NetworkStatus::ConnectedAsHost)) {
LOG_ERROR(Service_NWM, "Connection sequence aborted, because connection status is %u",
connection_status.status);
return;
}
assoc_response.channel = network_channel;
// TODO(Subv): This will cause multiple clients to end up with the same association id, but
// we're not using that for anything.
@ -142,6 +201,7 @@ void SendAssociationResponseFrame(const MacAddress& address) {
network_info.network_id);
assoc_response.destination_address = address;
assoc_response.type = WifiPacket::PacketType::AssociationResponse;
}
SendPacket(assoc_response);
}
@ -155,16 +215,23 @@ void SendAssociationResponseFrame(const MacAddress& address) {
void HandleAuthenticationFrame(const Network::WifiPacket& packet) {
// Only the SEQ1 auth frame is handled here, the SEQ2 frame doesn't need any special behavior
if (GetAuthenticationSeqNumber(packet.data) == AuthenticationSeq::SEQ1) {
ASSERT_MSG(connection_status.status == static_cast<u32>(NetworkStatus::ConnectedAsHost));
// Respond with an authentication response frame with SEQ2
using Network::WifiPacket;
WifiPacket auth_request;
{
std::lock_guard<std::mutex> lock(connection_status_mutex);
if (connection_status.status != static_cast<u32>(NetworkStatus::ConnectedAsHost)) {
LOG_ERROR(Service_NWM,
"Connection sequence aborted, because connection status is %u",
connection_status.status);
return;
}
// Respond with an authentication response frame with SEQ2
auth_request.channel = network_channel;
auth_request.data = GenerateAuthenticationFrame(AuthenticationSeq::SEQ2);
auth_request.destination_address = packet.transmitter_address;
auth_request.type = WifiPacket::PacketType::Authentication;
}
SendPacket(auth_request);
SendAssociationResponseFrame(packet.transmitter_address);
@ -180,6 +247,9 @@ void OnWifiPacketReceived(const Network::WifiPacket& packet) {
case Network::WifiPacket::PacketType::Authentication:
HandleAuthenticationFrame(packet);
break;
case Network::WifiPacket::PacketType::AssociationResponse:
HandleAssociationResponseFrame(packet);
break;
}
}
@ -305,7 +375,7 @@ static void InitializeWithVersion(Interface* self) {
u32 sharedmem_size = rp.Pop<u32>();
// Update the node information with the data the game gave us.
rp.PopRaw(node_info[0]);
rp.PopRaw(current_node);
u16 version = rp.Pop<u16>();
@ -315,10 +385,14 @@ static void InitializeWithVersion(Interface* self) {
ASSERT_MSG(recv_buffer_memory->size == sharedmem_size, "Invalid shared memory size.");
{
std::lock_guard<std::mutex> lock(connection_status_mutex);
// Reset the connection status, it contains all zeros after initialization,
// except for the actual status value.
connection_status = {};
connection_status.status = static_cast<u32>(NetworkStatus::NotConnected);
}
IPC::RequestBuilder rb = rp.MakeBuilder(1, 2);
rb.Push(RESULT_SUCCESS);
@ -348,12 +422,16 @@ static void GetConnectionStatus(Interface* self) {
IPC::RequestBuilder rb = rp.MakeBuilder(13, 0);
rb.Push(RESULT_SUCCESS);
{
std::lock_guard<std::mutex> lock(connection_status_mutex);
rb.PushRaw(connection_status);
// Reset the bitmask of changed nodes after each call to this
// function to prevent falsely informing games of outstanding
// changes in subsequent calls.
// TODO(Subv): Find exactly where the NWM module resets this value.
connection_status.changed_nodes = 0;
}
LOG_DEBUG(Service_NWM, "called");
}
@ -434,10 +512,13 @@ static void BeginHostingNetwork(Interface* self) {
// The real UDS module throws a fatal error if this assert fails.
ASSERT_MSG(network_info.max_nodes > 1, "Trying to host a network of only one member.");
{
std::lock_guard<std::mutex> lock(connection_status_mutex);
connection_status.status = static_cast<u32>(NetworkStatus::ConnectedAsHost);
// Ensure the application data size is less than the maximum value.
ASSERT_MSG(network_info.application_data_size <= ApplicationDataSize, "Data size is too big.");
ASSERT_MSG(network_info.application_data_size <= ApplicationDataSize,
"Data size is too big.");
// Set up basic information for this network.
network_info.oui_value = NintendoOUI;
@ -453,12 +534,14 @@ static void BeginHostingNetwork(Interface* self) {
network_info.total_nodes = 1;
// The host is always the first node
connection_status.network_node_id = 1;
node_info[0].network_node_id = 1;
current_node.network_node_id = 1;
connection_status.nodes[0] = connection_status.network_node_id;
// Set the bit 0 in the nodes bitmask to indicate that node 1 is already taken.
connection_status.node_bitmask |= 1;
// Notify the application that the first node was set.
connection_status.changed_nodes |= 1;
node_info[0] = current_node;
}
// If the game has a preferred channel, use that instead.
if (network_info.channel != 0)
@ -495,9 +578,13 @@ static void DestroyNetwork(Interface* self) {
// Unschedule the beacon broadcast event.
CoreTiming::UnscheduleEvent(beacon_broadcast_event, 0);
{
std::lock_guard<std::mutex> lock(connection_status_mutex);
// TODO(Subv): Check if connection_status is indeed reset after this call.
connection_status = {};
connection_status.status = static_cast<u8>(NetworkStatus::NotConnected);
}
connection_status_event->Signal();
IPC::RequestBuilder rb = rp.MakeBuilder(1, 0);
@ -540,6 +627,10 @@ static void SendTo(Interface* self) {
IPC::RequestBuilder rb = rp.MakeBuilder(1, 0);
u16 network_node_id;
{
std::lock_guard<std::mutex> lock(connection_status_mutex);
if (connection_status.status != static_cast<u32>(NetworkStatus::ConnectedAsClient) &&
connection_status.status != static_cast<u32>(NetworkStatus::ConnectedAsHost)) {
rb.Push(ResultCode(ErrorDescription::NotAuthorized, ErrorModule::UDS,
@ -553,6 +644,9 @@ static void SendTo(Interface* self) {
return;
}
network_node_id = connection_status.network_node_id;
}
// TODO(Subv): Do something with the flags.
constexpr size_t MaxSize = 0x5C6;
@ -567,8 +661,8 @@ static void SendTo(Interface* self) {
// TODO(Subv): Increment the sequence number after each sent packet.
u16 sequence_number = 0;
std::vector<u8> data_payload = GenerateDataPayload(
data, data_channel, dest_node_id, connection_status.network_node_id, sequence_number);
std::vector<u8> data_payload =
GenerateDataPayload(data, data_channel, dest_node_id, network_node_id, sequence_number);
// TODO(Subv): Retrieve the MAC address of the dest_node_id and our own to encrypt
// and encapsulate the payload.
@ -595,6 +689,7 @@ static void GetChannel(Interface* self) {
IPC::RequestParser rp(Kernel::GetCommandBuffer(), 0x1A, 0, 0);
IPC::RequestBuilder rb = rp.MakeBuilder(2, 0);
std::lock_guard<std::mutex> lock(connection_status_mutex);
bool is_connected = connection_status.status != static_cast<u32>(NetworkStatus::NotConnected);
u8 channel = is_connected ? network_channel : 0;
@ -766,6 +861,7 @@ static void BeaconBroadcastCallback(u64 userdata, int cycles_late) {
* @param network_node_id Network Node Id of the connecting client.
*/
void OnClientConnected(u16 network_node_id) {
std::lock_guard<std::mutex> lock(connection_status_mutex);
ASSERT_MSG(connection_status.status == static_cast<u32>(NetworkStatus::ConnectedAsHost),
"Can not accept clients if we're not hosting a network");
ASSERT_MSG(connection_status.total_nodes < connection_status.max_nodes,
@ -827,8 +923,11 @@ NWM_UDS::~NWM_UDS() {
connection_status_event = nullptr;
recv_buffer_memory = nullptr;
{
std::lock_guard<std::mutex> lock(connection_status_mutex);
connection_status = {};
connection_status.status = static_cast<u32>(NetworkStatus::NotConnected);
}
CoreTiming::UnscheduleEvent(beacon_broadcast_event, 0);
}

View file

@ -75,5 +75,14 @@ std::vector<u8> GenerateAssocResponseFrame(AssocStatus status, u16 association_i
return data;
}
std::tuple<AssocStatus, u16> GetAssociationResult(const std::vector<u8>& body) {
AssociationResponseFrame frame;
memcpy(&frame, body.data(), sizeof(frame));
constexpr u16 AssociationIdMask = 0x3FFF;
return std::make_tuple(static_cast<AssocStatus>(frame.status_code),
frame.assoc_id & AssociationIdMask);
}
} // namespace NWM
} // namespace Service

View file

@ -4,6 +4,7 @@
#pragma once
#include <tuple>
#include <vector>
#include "common/common_types.h"
#include "common/swap.h"
@ -47,5 +48,9 @@ AuthenticationSeq GetAuthenticationSeqNumber(const std::vector<u8>& body);
/// network id, starting at the frame body.
std::vector<u8> GenerateAssocResponseFrame(AssocStatus status, u16 association_id, u32 network_id);
/// Returns a tuple of (association status, association id) from the body of an AssociationResponse
/// frame.
std::tuple<AssocStatus, u16> GetAssociationResult(const std::vector<u8>& body);
} // namespace NWM
} // namespace Service

View file

@ -274,5 +274,26 @@ std::vector<u8> GenerateDataPayload(const std::vector<u8>& data, u8 channel, u16
return buffer;
}
std::vector<u8> GenerateEAPoLStartFrame(u16 association_id, const NodeInfo& node_info) {
EAPoLStartPacket eapol_start{};
eapol_start.association_id = association_id;
eapol_start.friend_code_seed = node_info.friend_code_seed;
for (int i = 0; i < node_info.username.size(); ++i)
eapol_start.username[i] = node_info.username[i];
// Note: The network_node_id and unknown bytes seem to be uninitialized in the NWM module.
// TODO(B3N30): The last 8 bytes seem to have a fixed value of 07 88 15 00 04 e9 13 00 in
// EAPoL-Start packets from different 3DSs to the same host during a Super Smash Bros. 4 game.
// Find out what that means.
std::vector<u8> eapol_buffer(sizeof(EAPoLStartPacket));
std::memcpy(eapol_buffer.data(), &eapol_start, sizeof(eapol_start));
std::vector<u8> buffer = GenerateLLCHeader(EtherType::EAPoL);
buffer.insert(buffer.end(), eapol_buffer.begin(), eapol_buffer.end());
return buffer;
}
} // namespace NWM
} // namespace Service

View file

@ -67,6 +67,27 @@ struct DataFrameCryptoCTR {
static_assert(sizeof(DataFrameCryptoCTR) == 16, "DataFrameCryptoCTR has the wrong size");
constexpr u16 EAPoLStartMagic = 0x201;
/*
* Nintendo EAPoLStartPacket, is used to initaliaze a connection between client and host
*/
struct EAPoLStartPacket {
u16_be magic = EAPoLStartMagic;
u16_be association_id;
// This value is hardcoded to 1 in the NWM module.
u16_be unknown = 1;
INSERT_PADDING_BYTES(2);
u64_be friend_code_seed;
std::array<u16_be, 10> username;
INSERT_PADDING_BYTES(4);
u16_be network_node_id;
INSERT_PADDING_BYTES(6);
};
static_assert(sizeof(EAPoLStartPacket) == 0x30, "EAPoLStartPacket has the wrong size");
/**
* Generates an unencrypted 802.11 data payload.
* @returns The generated frame payload.
@ -74,5 +95,12 @@ static_assert(sizeof(DataFrameCryptoCTR) == 16, "DataFrameCryptoCTR has the wron
std::vector<u8> GenerateDataPayload(const std::vector<u8>& data, u8 channel, u16 dest_node,
u16 src_node, u16 sequence_number);
/*
* Generates an unencrypted 802.11 data frame body with the EAPoL-Start format for UDS
* communication.
* @returns The generated frame body.
*/
std::vector<u8> GenerateEAPoLStartFrame(u16 association_id, const NodeInfo& node_info);
} // namespace NWM
} // namespace Service