| /* |
| * |
| * Copyright (c) 2022 Project CHIP Authors |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| #include <lib/dnssd/minimal_mdns/AddressPolicy.h> |
| |
| #include <lib/support/logging/CHIPLogging.h> |
| |
| namespace mdns { |
| namespace Minimal { |
| namespace { |
| |
| /// Checks if the current interface is powered on |
| /// and not local loopback. |
| template <typename T> |
| bool IsCurrentInterfaceUsable(T & iterator) |
| { |
| if (!iterator.IsUp()) |
| { |
| return false; // not a usable interface |
| } |
| char name[chip::Inet::InterfaceId::kMaxIfNameLength]; |
| if (iterator.GetInterfaceName(name, sizeof(name)) != CHIP_NO_ERROR) |
| { |
| ChipLogError(Discovery, "Failed to get interface name."); |
| return false; |
| } |
| |
| // TODO: need a better way to ignore local loopback interfaces/addresses |
| // We do not want to listen on local loopback even though they are up and |
| // support multicast |
| // |
| // Some way to detect 'is local looback' that is smarter (e.g. at least |
| // strict string compare on linux instead of substring) would be better. |
| // |
| // This would reject likely valid interfaces like 'lollipop' or 'lostinspace' |
| if (strncmp(name, "lo", 2) == 0) |
| { |
| /// local loopback interface is not usable by MDNS |
| return false; |
| } |
| return true; |
| } |
| |
| class AllInterfaces : public mdns::Minimal::ListenIterator |
| { |
| public: |
| AllInterfaces() { SkipToFirstValidInterface(); } |
| |
| bool Next(chip::Inet::InterfaceId * id, chip::Inet::IPAddressType * type) override |
| { |
| if (!mIterator.HasCurrent()) |
| { |
| return false; |
| } |
| |
| #if INET_CONFIG_ENABLE_IPV4 |
| if (mState == State::kIpV4) |
| { |
| *id = mIterator.GetInterfaceId(); |
| *type = chip::Inet::IPAddressType::kIPv4; |
| mState = State::kIpV6; |
| return true; |
| } |
| #endif |
| |
| *id = mIterator.GetInterfaceId(); |
| *type = chip::Inet::IPAddressType::kIPv6; |
| #if INET_CONFIG_ENABLE_IPV4 |
| mState = State::kIpV4; |
| #endif |
| |
| for (mIterator.Next(); SkipCurrentInterface(); mIterator.Next()) |
| { |
| } |
| return true; |
| } |
| |
| private: |
| #if INET_CONFIG_ENABLE_IPV4 |
| enum class State |
| { |
| kIpV4, |
| kIpV6, |
| }; |
| State mState = State::kIpV4; |
| #endif |
| chip::Inet::InterfaceIterator mIterator; |
| |
| void SkipToFirstValidInterface() |
| { |
| do |
| { |
| if (!SkipCurrentInterface()) |
| { |
| break; |
| } |
| } while (mIterator.Next()); |
| } |
| |
| bool SkipCurrentInterface() |
| { |
| if (!mIterator.HasCurrent()) |
| { |
| return false; // nothing to try. |
| } |
| |
| return !IsCurrentInterfaceUsable(mIterator); |
| } |
| }; |
| |
| class AllAddressesIterator : public mdns::Minimal::IpAddressIterator |
| { |
| public: |
| AllAddressesIterator(chip::Inet::InterfaceId interfaceId, chip::Inet::IPAddressType addrType) : |
| mInterfaceIdFilter(interfaceId), mAddrType(addrType) |
| {} |
| |
| bool Next(chip::Inet::IPAddress & dest) |
| { |
| while (true) |
| { |
| if (!mIterator.HasCurrent()) |
| { |
| return false; |
| } |
| |
| if (mIterator.GetInterfaceId() != mInterfaceIdFilter) |
| { |
| mIterator.Next(); |
| continue; |
| } |
| |
| CHIP_ERROR err = mIterator.GetAddress(dest); |
| mIterator.Next(); |
| |
| if (mAddrType != chip::Inet::IPAddressType::kAny) |
| { |
| if (dest.Type() != mAddrType) |
| { |
| continue; |
| } |
| } |
| |
| if (err != CHIP_NO_ERROR) |
| { |
| ChipLogError(Discovery, "Failed to fetch interface IP address: %" CHIP_ERROR_FORMAT, err.Format()); |
| continue; |
| } |
| |
| return true; |
| } |
| } |
| |
| private: |
| const chip::Inet::InterfaceId mInterfaceIdFilter; |
| const chip::Inet::IPAddressType mAddrType; |
| chip::Inet::InterfaceAddressIterator mIterator; |
| }; |
| |
| class DefaultAddressPolicy : public AddressPolicy |
| { |
| public: |
| chip::Platform::UniquePtr<ListenIterator> GetListenEndpoints() override |
| { |
| return chip::Platform::UniquePtr<ListenIterator>(chip::Platform::New<AllInterfaces>()); |
| } |
| |
| chip::Platform::UniquePtr<IpAddressIterator> GetIpAddressesForEndpoint(chip::Inet::InterfaceId interfaceId, |
| chip::Inet::IPAddressType type) override |
| { |
| return chip::Platform::UniquePtr<IpAddressIterator>(chip::Platform::New<AllAddressesIterator>(interfaceId, type)); |
| } |
| }; |
| |
| DefaultAddressPolicy gDefaultAddressPolicy; |
| |
| } // namespace |
| |
| void SetDefaultAddressPolicy() |
| { |
| SetAddressPolicy(&gDefaultAddressPolicy); |
| } |
| |
| } // namespace Minimal |
| } // namespace mdns |