| // Copyright 2018 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 "arc/network/device.h" |
| |
| #include <arpa/inet.h> |
| #include <sys/socket.h> |
| #include <sys/types.h> |
| |
| #include <map> |
| #include <utility> |
| |
| #include <base/bind.h> |
| #include <base/lazy_instance.h> |
| #include <base/logging.h> |
| #include <base/strings/stringprintf.h> |
| |
| #include "arc/network/arc_ip_config.h" |
| |
| namespace arc_networkd { |
| |
| // These are used to identify which ARC++ data path should be used when setting |
| // up the Android device. |
| const char kAndroidDevice[] = "arc0"; |
| const char kAndroidLegacyDevice[] = "android"; |
| |
| namespace { |
| |
| constexpr uint32_t kMdnsMcastAddress = 0xfb0000e0; // 224.0.0.251 (NBO) |
| constexpr uint16_t kMdnsPort = 5353; |
| constexpr uint32_t kSsdpMcastAddress = 0xfaffffef; // 239.255.255.250 (NBO) |
| constexpr uint16_t kSsdpPort = 1900; |
| |
| constexpr int kMaxRandomAddressTries = 3; |
| |
| std::string MacAddressToString(const MacAddress& addr) { |
| return base::StringPrintf("%02x:%02x:%02x:%02x:%02x:%02x", addr[0], addr[1], |
| addr[2], addr[3], addr[4], addr[5]); |
| } |
| |
| std::string IPv4AddressToString(uint32_t addr) { |
| char buf[INET_ADDRSTRLEN] = {0}; |
| struct in_addr ia; |
| ia.s_addr = addr; |
| return !inet_ntop(AF_INET, &ia, buf, sizeof(buf)) ? "" : buf; |
| } |
| |
| } // namespace |
| |
| Device::Config::Config(const std::string& host_ifname, |
| const std::string& guest_ifname, |
| const MacAddress& guest_mac_addr, |
| std::unique_ptr<Subnet> ipv4_subnet, |
| std::unique_ptr<SubnetAddress> host_ipv4_addr, |
| std::unique_ptr<SubnetAddress> guest_ipv4_addr) |
| : host_ifname_(host_ifname), |
| guest_ifname_(guest_ifname), |
| guest_mac_addr_(guest_mac_addr), |
| ipv4_subnet_(std::move(ipv4_subnet)), |
| host_ipv4_addr_(std::move(host_ipv4_addr)), |
| guest_ipv4_addr_(std::move(guest_ipv4_addr)) {} |
| |
| Device::Device(const std::string& ifname, |
| std::unique_ptr<Device::Config> config, |
| const Device::Options& options, |
| const MessageSink& msg_sink) |
| : ifname_(ifname), |
| config_(std::move(config)), |
| options_(options), |
| msg_sink_(msg_sink) { |
| DCHECK(config_); |
| if (msg_sink_.is_null()) |
| return; |
| |
| IpHelperMessage msg; |
| msg.set_dev_ifname(ifname_); |
| auto* dev_config = msg.mutable_dev_config(); |
| FillProto(dev_config); |
| msg_sink_.Run(msg); |
| } |
| |
| Device::~Device() { |
| if (msg_sink_.is_null()) |
| return; |
| |
| IpHelperMessage msg; |
| msg.set_dev_ifname(ifname_); |
| msg.set_teardown(true); |
| msg_sink_.Run(msg); |
| } |
| |
| void Device::FillProto(DeviceConfig* msg) { |
| msg->set_br_ifname(config_->host_ifname()); |
| msg->set_br_ipv4(IPv4AddressToString(config_->host_ipv4_addr())); |
| msg->set_arc_ifname(config_->guest_ifname()); |
| msg->set_arc_ipv4(IPv4AddressToString(config_->guest_ipv4_addr())); |
| msg->set_mac_addr(MacAddressToString(config_->guest_mac_addr())); |
| |
| msg->set_fwd_multicast(options_.fwd_multicast); |
| msg->set_find_ipv6_routes(options_.find_ipv6_routes); |
| } |
| |
| void Device::Enable(const std::string& ifname) { |
| if (ifname.empty()) |
| return; |
| |
| LOG(INFO) << "Enabling device " << ifname_; |
| |
| // If operating in legacy single network mode, enable inbound traffic to ARC |
| // from the interface. |
| if (ifname_ == kAndroidLegacyDevice) { |
| LOG(INFO) << "Binding interface " << ifname << " to device " << ifname_; |
| legacy_lan_ifname_ = ifname; |
| |
| if (!msg_sink_.is_null()) { |
| IpHelperMessage msg; |
| msg.set_dev_ifname(ifname_); |
| msg.set_enable_inbound_ifname(legacy_lan_ifname_); |
| msg_sink_.Run(msg); |
| } |
| } |
| |
| // TODO(garrick): Revisit multicast forwarding when NAT rules are enabled |
| // for other devices. |
| if (options_.fwd_multicast) { |
| mdns_forwarder_.reset(new MulticastForwarder()); |
| mdns_forwarder_->Start(config_->host_ifname(), legacy_lan_ifname_, |
| config_->guest_ipv4_addr(), kMdnsMcastAddress, |
| kMdnsPort, |
| /* allow_stateless */ true); |
| |
| ssdp_forwarder_.reset(new MulticastForwarder()); |
| ssdp_forwarder_->Start(config_->host_ifname(), legacy_lan_ifname_, |
| INADDR_ANY, kSsdpMcastAddress, kSsdpPort, |
| /* allow_stateless */ false); |
| } |
| |
| if (options_.find_ipv6_routes) { |
| router_finder_.reset(new RouterFinder()); |
| router_finder_->Start( |
| legacy_lan_ifname_, |
| base::Bind(&Device::OnRouteFound, weak_factory_.GetWeakPtr())); |
| } |
| } |
| |
| void Device::Disable() { |
| LOG(INFO) << "Disabling device " << ifname_; |
| |
| neighbor_finder_.reset(); |
| router_finder_.reset(); |
| ssdp_forwarder_.reset(); |
| mdns_forwarder_.reset(); |
| |
| // The rest of this function clears state applicable only when operating in |
| // legacy single network mode. |
| if (msg_sink_.is_null() || ifname_ != kAndroidLegacyDevice) |
| return; |
| |
| // Clear IPv6 info, if necessary. |
| if (options_.find_ipv6_routes) { |
| IpHelperMessage msg; |
| msg.set_dev_ifname(ifname_); |
| msg.set_clear_arc_ip(true); |
| msg_sink_.Run(msg); |
| } |
| |
| // Disable inbound traffic. |
| if (!legacy_lan_ifname_.empty()) { |
| LOG(INFO) << "Unbinding interface " << legacy_lan_ifname_ << " from device " |
| << ifname_; |
| legacy_lan_ifname_.clear(); |
| |
| IpHelperMessage msg; |
| msg.set_dev_ifname(ifname_); |
| msg.set_disable_inbound(true); |
| msg_sink_.Run(msg); |
| } |
| } |
| |
| void Device::OnRouteFound(const struct in6_addr& prefix, |
| int prefix_len, |
| const struct in6_addr& router) { |
| if (prefix_len == 64) { |
| LOG(INFO) << "Found IPv6 network on iface " << legacy_lan_ifname_ |
| << " route=" << prefix << "/" << prefix_len |
| << ", gateway=" << router; |
| |
| memcpy(&random_address_, &prefix, sizeof(random_address_)); |
| random_address_prefix_len_ = prefix_len; |
| random_address_tries_ = 0; |
| |
| ArcIpConfig::GenerateRandom(&random_address_, random_address_prefix_len_); |
| |
| neighbor_finder_.reset(new NeighborFinder()); |
| neighbor_finder_->Check( |
| legacy_lan_ifname_, random_address_, |
| base::Bind(&Device::OnNeighborCheckResult, weak_factory_.GetWeakPtr())); |
| } else { |
| LOG(INFO) << "No IPv6 connectivity available on " << legacy_lan_ifname_; |
| } |
| } |
| |
| void Device::OnNeighborCheckResult(bool found) { |
| if (found) { |
| if (++random_address_tries_ >= kMaxRandomAddressTries) { |
| LOG(WARNING) << "Too many IP collisions, giving up."; |
| return; |
| } |
| |
| struct in6_addr previous_address = random_address_; |
| ArcIpConfig::GenerateRandom(&random_address_, random_address_prefix_len_); |
| |
| LOG(INFO) << "Detected IP collision for " << previous_address |
| << ", retrying with new address " << random_address_; |
| |
| neighbor_finder_->Check( |
| legacy_lan_ifname_, random_address_, |
| base::Bind(&Device::OnNeighborCheckResult, weak_factory_.GetWeakPtr())); |
| } else { |
| struct in6_addr router; |
| |
| if (!ArcIpConfig::GetV6Address(config_->host_ifname(), &router)) { |
| LOG(ERROR) << "Error reading link local address for " |
| << config_->host_ifname(); |
| return; |
| } |
| |
| LOG(INFO) << "Setting IPv6 address " << random_address_ |
| << "/128, gateway=" << router << " on " << legacy_lan_ifname_; |
| |
| // Set up new ARC IPv6 address, NDP, and forwarding rules. |
| if (!msg_sink_.is_null()) { |
| IpHelperMessage msg; |
| msg.set_dev_ifname(ifname_); |
| SetArcIp* setup_msg = msg.mutable_set_arc_ip(); |
| setup_msg->set_prefix(&random_address_, sizeof(struct in6_addr)); |
| setup_msg->set_prefix_len(128); |
| setup_msg->set_router(&router, sizeof(struct in6_addr)); |
| setup_msg->set_lan_ifname(legacy_lan_ifname_); |
| msg_sink_.Run(msg); |
| } |
| } |
| } |
| |
| } // namespace arc_networkd |