// Copyright 2016 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.

#include "patchpanel/client.h"

#include <fcntl.h>

#include <base/logging.h>
#include <chromeos/dbus/service_constants.h>
#include <dbus/message.h>
#include <dbus/object_path.h>

#include "patchpanel/net_util.h"

namespace patchpanel {

namespace {

std::ostream& operator<<(std::ostream& stream,
                         const ModifyPortRuleRequest& request) {
  stream << "{ operation: "
         << ModifyPortRuleRequest::Operation_Name(request.op())
         << ", rule type: "
         << ModifyPortRuleRequest::RuleType_Name(request.type())
         << ", protocol: "
         << ModifyPortRuleRequest::Protocol_Name(request.proto());
  if (!request.input_ifname().empty()) {
    stream << ", input interface name: " << request.input_ifname();
  }
  if (!request.input_dst_ip().empty()) {
    stream << ", input destination IP: " << request.input_dst_ip();
  }
  stream << ", input destination port: " << request.input_dst_port();
  if (!request.dst_ip().empty()) {
    stream << ", destination IP: " << request.dst_ip();
  }
  if (request.dst_port() != 0) {
    stream << ", destination port: " << request.dst_port();
  }
  stream << " }";
  return stream;
}

}  // namespace

// static
std::unique_ptr<Client> Client::New() {
  dbus::Bus::Options opts;
  opts.bus_type = dbus::Bus::SYSTEM;
  scoped_refptr<dbus::Bus> bus(new dbus::Bus(std::move(opts)));

  if (!bus->Connect()) {
    LOG(ERROR) << "Failed to connect to system bus";
    return nullptr;
  }

  dbus::ObjectProxy* proxy = bus->GetObjectProxy(
      kPatchPanelServiceName, dbus::ObjectPath(kPatchPanelServicePath));
  if (!proxy) {
    LOG(ERROR) << "Unable to get dbus proxy for " << kPatchPanelServiceName;
    return nullptr;
  }

  return std::make_unique<Client>(std::move(bus), proxy);
}

Client::~Client() {
  if (bus_)
    bus_->ShutdownAndBlock();
}

bool Client::NotifyArcStartup(pid_t pid) {
  dbus::MethodCall method_call(kPatchPanelInterface, kArcStartupMethod);
  dbus::MessageWriter writer(&method_call);

  ArcStartupRequest request;
  request.set_pid(static_cast<uint32_t>(pid));

  if (!writer.AppendProtoAsArrayOfBytes(request)) {
    LOG(ERROR) << "Failed to encode ArcStartupRequest proto";
    return false;
  }

  std::unique_ptr<dbus::Response> dbus_response = proxy_->CallMethodAndBlock(
      &method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT);
  if (!dbus_response) {
    LOG(ERROR) << "Failed to send dbus message to patchpanel service";
    return false;
  }

  dbus::MessageReader reader(dbus_response.get());
  ArcStartupResponse response;
  if (!reader.PopArrayOfBytesAsProto(&response)) {
    LOG(ERROR) << "Failed to parse response proto";
    return false;
  }

  return true;
}

bool Client::NotifyArcShutdown() {
  dbus::MethodCall method_call(kPatchPanelInterface, kArcShutdownMethod);
  dbus::MessageWriter writer(&method_call);

  ArcShutdownRequest request;
  if (!writer.AppendProtoAsArrayOfBytes(request)) {
    LOG(ERROR) << "Failed to encode ArcShutdownRequest proto";
    return false;
  }

  std::unique_ptr<dbus::Response> dbus_response = proxy_->CallMethodAndBlock(
      &method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT);
  if (!dbus_response) {
    LOG(ERROR) << "Failed to send dbus message to patchpanel service";
    return false;
  }

  dbus::MessageReader reader(dbus_response.get());
  ArcShutdownResponse response;
  if (!reader.PopArrayOfBytesAsProto(&response)) {
    LOG(ERROR) << "Failed to parse response proto";
    return false;
  }

  return true;
}

std::vector<NetworkDevice> Client::NotifyArcVmStartup(uint32_t cid) {
  dbus::MethodCall method_call(kPatchPanelInterface, kArcVmStartupMethod);
  dbus::MessageWriter writer(&method_call);

  ArcVmStartupRequest request;
  request.set_cid(cid);

  if (!writer.AppendProtoAsArrayOfBytes(request)) {
    LOG(ERROR) << "Failed to encode ArcVmStartupRequest proto";
    return {};
  }

  std::unique_ptr<dbus::Response> dbus_response = proxy_->CallMethodAndBlock(
      &method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT);
  if (!dbus_response) {
    LOG(ERROR) << "Failed to send dbus message to patchpanel service";
    return {};
  }

  dbus::MessageReader reader(dbus_response.get());
  ArcVmStartupResponse response;
  if (!reader.PopArrayOfBytesAsProto(&response)) {
    LOG(ERROR) << "Failed to parse response proto";
    return {};
  }

  std::vector<NetworkDevice> devices;
  for (const auto& d : response.devices()) {
    devices.emplace_back(d);
  }
  return devices;
}

bool Client::NotifyArcVmShutdown(uint32_t cid) {
  dbus::MethodCall method_call(kPatchPanelInterface, kArcVmShutdownMethod);
  dbus::MessageWriter writer(&method_call);

  ArcVmShutdownRequest request;
  request.set_cid(cid);

  if (!writer.AppendProtoAsArrayOfBytes(request)) {
    LOG(ERROR) << "Failed to encode ArcVmShutdownRequest proto";
    return false;
  }

  std::unique_ptr<dbus::Response> dbus_response = proxy_->CallMethodAndBlock(
      &method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT);
  if (!dbus_response) {
    LOG(ERROR) << "Failed to send dbus message to patchpanel service";
    return false;
  }

  dbus::MessageReader reader(dbus_response.get());
  ArcVmShutdownResponse response;
  if (!reader.PopArrayOfBytesAsProto(&response)) {
    LOG(ERROR) << "Failed to parse response proto";
    return false;
  }

  return true;
}

bool Client::NotifyTerminaVmStartup(uint32_t cid,
                                    NetworkDevice* device,
                                    IPv4Subnet* container_subnet) {
  dbus::MethodCall method_call(kPatchPanelInterface, kTerminaVmStartupMethod);
  dbus::MessageWriter writer(&method_call);

  TerminaVmStartupRequest request;
  request.set_cid(cid);

  if (!writer.AppendProtoAsArrayOfBytes(request)) {
    LOG(ERROR) << "Failed to encode TerminaVmStartupRequest proto";
    return false;
  }

  std::unique_ptr<dbus::Response> dbus_response = proxy_->CallMethodAndBlock(
      &method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT);
  if (!dbus_response) {
    LOG(ERROR) << "Failed to send dbus message to patchpanel service";
    return false;
  }

  dbus::MessageReader reader(dbus_response.get());
  TerminaVmStartupResponse response;
  if (!reader.PopArrayOfBytesAsProto(&response)) {
    LOG(ERROR) << "Failed to parse response proto";
    return false;
  }

  if (!response.has_device()) {
    LOG(ERROR) << "No device found";
    return false;
  }
  *device = response.device();

  if (response.has_container_subnet()) {
    *container_subnet = response.container_subnet();
  } else {
    LOG(WARNING) << "No container subnet found";
  }

  return true;
}

bool Client::NotifyTerminaVmShutdown(uint32_t cid) {
  dbus::MethodCall method_call(kPatchPanelInterface, kTerminaVmShutdownMethod);
  dbus::MessageWriter writer(&method_call);

  TerminaVmShutdownRequest request;
  request.set_cid(cid);

  if (!writer.AppendProtoAsArrayOfBytes(request)) {
    LOG(ERROR) << "Failed to encode TerminaVmShutdownRequest proto";
    return false;
  }

  std::unique_ptr<dbus::Response> dbus_response = proxy_->CallMethodAndBlock(
      &method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT);
  if (!dbus_response) {
    LOG(ERROR) << "Failed to send dbus message to patchpanel service";
    return false;
  }

  dbus::MessageReader reader(dbus_response.get());
  TerminaVmShutdownResponse response;
  if (!reader.PopArrayOfBytesAsProto(&response)) {
    LOG(ERROR) << "Failed to parse response proto";
    return false;
  }

  return true;
}

bool Client::NotifyPluginVmStartup(uint64_t vm_id,
                                   int subnet_index,
                                   NetworkDevice* device) {
  dbus::MethodCall method_call(kPatchPanelInterface, kPluginVmStartupMethod);
  dbus::MessageWriter writer(&method_call);

  PluginVmStartupRequest request;
  request.set_id(vm_id);
  request.set_subnet_index(subnet_index);

  if (!writer.AppendProtoAsArrayOfBytes(request)) {
    LOG(ERROR) << "Failed to encode PluginVmStartupRequest proto";
    return false;
  }

  std::unique_ptr<dbus::Response> dbus_response = proxy_->CallMethodAndBlock(
      &method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT);
  if (!dbus_response) {
    LOG(ERROR) << "Failed to send dbus message to patchpanel service";
    return false;
  }

  dbus::MessageReader reader(dbus_response.get());
  PluginVmStartupResponse response;
  if (!reader.PopArrayOfBytesAsProto(&response)) {
    LOG(ERROR) << "Failed to parse response proto";
    return false;
  }

  if (!response.has_device()) {
    LOG(ERROR) << "No device found";
    return false;
  }
  *device = response.device();

  return true;
}

bool Client::NotifyPluginVmShutdown(uint64_t vm_id) {
  dbus::MethodCall method_call(kPatchPanelInterface, kPluginVmShutdownMethod);
  dbus::MessageWriter writer(&method_call);

  PluginVmShutdownRequest request;
  request.set_id(vm_id);

  if (!writer.AppendProtoAsArrayOfBytes(request)) {
    LOG(ERROR) << "Failed to encode PluginVmShutdownRequest proto";
    return false;
  }

  std::unique_ptr<dbus::Response> dbus_response = proxy_->CallMethodAndBlock(
      &method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT);
  if (!dbus_response) {
    LOG(ERROR) << "Failed to send dbus message to patchpanel service";
    return false;
  }

  dbus::MessageReader reader(dbus_response.get());
  PluginVmShutdownResponse response;
  if (!reader.PopArrayOfBytesAsProto(&response)) {
    LOG(ERROR) << "Failed to parse response proto";
    return false;
  }

  return true;
}

bool Client::DefaultVpnRouting(int socket) {
  return SendSetVpnIntentRequest(socket, SetVpnIntentRequest::DEFAULT_ROUTING);
}

bool Client::RouteOnVpn(int socket) {
  return SendSetVpnIntentRequest(socket, SetVpnIntentRequest::ROUTE_ON_VPN);
}

bool Client::BypassVpn(int socket) {
  return SendSetVpnIntentRequest(socket, SetVpnIntentRequest::BYPASS_VPN);
}

bool Client::SendSetVpnIntentRequest(
    int socket, SetVpnIntentRequest::VpnRoutingPolicy policy) {
  dbus::MethodCall method_call(kPatchPanelInterface, kSetVpnIntentMethod);
  dbus::MessageWriter writer(&method_call);

  SetVpnIntentRequest request;
  SetVpnIntentResponse response;
  request.set_policy(policy);

  if (!writer.AppendProtoAsArrayOfBytes(request)) {
    LOG(ERROR) << "Failed to encode SetVpnIntentRequest proto";
    return false;
  }
  writer.AppendFileDescriptor(socket);

  std::unique_ptr<dbus::Response> dbus_response = proxy_->CallMethodAndBlock(
      &method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT);
  if (!dbus_response) {
    LOG(ERROR)
        << "Failed to send SetVpnIntentRequest message to patchpanel service";
    return false;
  }

  dbus::MessageReader reader(dbus_response.get());
  if (!reader.PopArrayOfBytesAsProto(&response)) {
    LOG(ERROR) << "Failed to parse SetVpnIntentResponse proto";
    return false;
  }

  if (!response.success()) {
    LOG(ERROR) << "SetVpnIntentRequest failed";
    return false;
  }
  return true;
}

std::pair<base::ScopedFD, patchpanel::ConnectNamespaceResponse>
Client::ConnectNamespace(pid_t pid,
                         const std::string& outbound_ifname,
                         bool forward_user_traffic) {
  // Prepare and serialize the request proto.
  ConnectNamespaceRequest request;
  request.set_pid(static_cast<int32_t>(pid));
  request.set_outbound_physical_device(outbound_ifname);
  request.set_allow_user_traffic(forward_user_traffic);

  dbus::MethodCall method_call(kPatchPanelInterface, kConnectNamespaceMethod);
  dbus::MessageWriter writer(&method_call);
  if (!writer.AppendProtoAsArrayOfBytes(request)) {
    LOG(ERROR) << "Failed to encode ConnectNamespaceRequest proto";
    return {};
  }

  // Prepare an fd pair and append one fd directly after the serialized request.
  int pipe_fds[2] = {-1, -1};
  if (pipe2(pipe_fds, O_CLOEXEC) < 0) {
    PLOG(ERROR) << "Failed to create a pair of fds with pipe2()";
    return {};
  }
  base::ScopedFD fd_local(pipe_fds[0]);
  // MessageWriter::AppendFileDescriptor duplicates the fd, so use ScopeFD to
  // make sure the original fd is closed eventually.
  base::ScopedFD fd_remote(pipe_fds[1]);
  writer.AppendFileDescriptor(pipe_fds[1]);

  std::unique_ptr<dbus::Response> dbus_response = proxy_->CallMethodAndBlock(
      &method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT);
  if (!dbus_response) {
    LOG(ERROR) << "Failed to send ConnectNamespace message to patchpanel";
    return {};
  }

  dbus::MessageReader reader(dbus_response.get());
  ConnectNamespaceResponse response;
  if (!reader.PopArrayOfBytesAsProto(&response)) {
    LOG(ERROR) << "Failed to parse ConnectNamespaceResponse proto";
    return {};
  }

  if (response.peer_ifname().empty() || response.host_ifname().empty()) {
    LOG(ERROR) << "ConnectNamespace for netns pid " << pid << " failed";
    return {};
  }

  std::string subnet_info = IPv4AddressToCidrString(
      response.ipv4_subnet().base_addr(), response.ipv4_subnet().prefix_len());
  LOG(INFO) << "ConnectNamespace for netns pid " << pid
            << " succeeded: peer_ifname=" << response.peer_ifname()
            << " peer_ipv4_address="
            << IPv4AddressToString(response.peer_ipv4_address())
            << " host_ifname=" << response.host_ifname()
            << " host_ipv4_address="
            << IPv4AddressToString(response.host_ipv4_address())
            << " subnet=" << subnet_info;

  return std::make_pair(std::move(fd_local), std::move(response));
}

std::vector<TrafficCounter> Client::GetTrafficCounters(
    const std::set<std::string>& devices) {
  dbus::MethodCall method_call(kPatchPanelInterface, kGetTrafficCountersMethod);
  dbus::MessageWriter writer(&method_call);

  TrafficCountersRequest request;
  for (const auto& device : devices) {
    request.add_devices(device);
  }

  if (!writer.AppendProtoAsArrayOfBytes(request)) {
    LOG(ERROR) << "Failed to encode TrafficCountersRequest proto";
    return {};
  }

  std::unique_ptr<dbus::Response> dbus_response = proxy_->CallMethodAndBlock(
      &method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT);
  if (!dbus_response) {
    LOG(ERROR) << "Failed to send TrafficCountersRequest message to patchpanel "
                  "service";
    return {};
  }

  TrafficCountersResponse response;
  dbus::MessageReader reader(dbus_response.get());
  if (!reader.PopArrayOfBytesAsProto(&response)) {
    LOG(ERROR) << "Failed to parse TrafficCountersResponse proto";
    return {};
  }

  return {response.counters().begin(), response.counters().end()};
}

bool Client::ModifyPortRule(ModifyPortRuleRequest::Operation op,
                            ModifyPortRuleRequest::RuleType type,
                            ModifyPortRuleRequest::Protocol proto,
                            const std::string& input_ifname,
                            const std::string& input_dst_ip,
                            uint32_t input_dst_port,
                            const std::string& dst_ip,
                            uint32_t dst_port) {
  dbus::MethodCall method_call(kPatchPanelInterface, kModifyPortRuleMethod);
  dbus::MessageWriter writer(&method_call);

  ModifyPortRuleRequest request;
  ModifyPortRuleResponse response;

  request.set_op(op);
  request.set_type(type);
  request.set_proto(proto);
  request.set_input_ifname(input_ifname);
  request.set_input_dst_ip(input_dst_ip);
  request.set_input_dst_port(input_dst_port);
  request.set_dst_ip(dst_ip);
  request.set_dst_port(dst_port);

  if (!writer.AppendProtoAsArrayOfBytes(request)) {
    LOG(ERROR) << "Failed to encode ModifyPortRuleRequest proto " << request;
    return false;
  }

  std::unique_ptr<dbus::Response> dbus_response = proxy_->CallMethodAndBlock(
      &method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT);
  if (!dbus_response) {
    LOG(ERROR)
        << "Failed to send ModifyPortRuleRequest message to patchpanel service "
        << request;
    return false;
  }

  dbus::MessageReader reader(dbus_response.get());
  if (!reader.PopArrayOfBytesAsProto(&response)) {
    LOG(ERROR) << "Failed to parse ModifyPortRuleResponse proto " << request;
    return false;
  }

  if (!response.success()) {
    LOG(ERROR) << "ModifyPortRuleRequest failed " << request;
    return false;
  }
  return true;
}

}  // namespace patchpanel