| /* |
| * Copyright 2017, The Android Open Source Project |
| * |
| * 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. |
| */ |
| #pragma once |
| |
| #include "interface.h" |
| #include "message.h" |
| #include "result.h" |
| #include "router.h" |
| #include "socket.h" |
| #include "timer.h" |
| |
| #include <netinet/in.h> |
| #include <stdint.h> |
| |
| #include <random> |
| |
| |
| class DhcpClient { |
| public: |
| DhcpClient(); |
| |
| // Initialize the DHCP client to listen on |interfaceName|. |
| Result init(const char* interfaceName); |
| Result run(); |
| private: |
| enum class State { |
| Init, |
| Selecting, |
| Requesting, |
| Bound, |
| Renewing, |
| Rebinding |
| }; |
| const char* stateToStr(State state); |
| |
| // Wait for any pending timeouts |
| void waitAndReceive(const sigset_t& pollSignalMask); |
| // Create a varying timeout (+- 1 second) based on the next timeout. |
| uint32_t calculateTimeoutMillis(); |
| // Increase the next timeout in a manner that's compliant with the DHCP RFC. |
| void increaseTimeout(); |
| // Move to |state|, the next poll timeout will be zero and the new |
| // state will be immediately evaluated. |
| void setNextState(State state); |
| // Configure network interface based on the DHCP configuration in |msg|. |
| bool configureDhcp(const Message& msg); |
| // Halt network operations on the network interface for when configuration |
| // is not possible and the protocol demands it. |
| void haltNetwork(); |
| // Receive a message on the socket and populate |msg| with the received |
| // data. If the message is a valid DHCP message the method returns true. If |
| // it's not valid false is returned. |
| bool receiveDhcpMessage(Message* msg); |
| |
| void sendDhcpDiscover(); |
| void sendDhcpRequest(in_addr_t destination); |
| void sendMessage(const Message& message); |
| Result send(in_addr_t source, in_addr_t destination, |
| uint16_t sourcePort, uint16_t destinationPort, |
| const uint8_t* data, size_t size); |
| |
| std::mt19937 mRandomEngine; // Mersenne Twister RNG |
| std::uniform_int_distribution<int> mRandomDistribution; |
| |
| struct DhcpInfo { |
| uint32_t t1; |
| uint32_t t2; |
| uint32_t leaseTime; |
| uint16_t mtu; |
| in_addr_t dns[4]; |
| in_addr_t gateway; |
| in_addr_t subnetMask; |
| in_addr_t serverId; |
| in_addr_t offeredAddress; |
| } mDhcpInfo; |
| |
| Router mRouter; |
| Interface mInterface; |
| Message mLastMsg; |
| Timer mT1, mT2; |
| Socket mSocket; |
| State mState; |
| uint32_t mNextTimeout; |
| bool mFuzzNextTimeout; |
| |
| in_addr_t mRequestAddress; // Address we'd like to use in requests |
| in_addr_t mServerAddress; // Server to send request to |
| }; |
| |