1 /*
2  * Copyright (C) 2024 Huawei Device Co., Ltd.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at
6  *
7  *     http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15 
16 #ifndef OHOS_DHCP_ARP_CHECKER_H
17 #define OHOS_DHCP_ARP_CHECKER_H
18 
19 #include <arpa/inet.h>
20 #include <netinet/if_ether.h>
21 #include <string>
22 
23 namespace OHOS {
24 namespace DHCP {
25 constexpr int32_t IPV4_ALEN = 4;
26 constexpr int32_t INTEGER_MAX = 0x7FFFFFFF;
27 
28 struct ArpPacket {
29     uint16_t ar_hrd; // hardware type
30     uint16_t ar_pro; // protocol type
31     uint8_t ar_hln; // length of hardware address
32     uint8_t ar_pln; // length of protocol address
33     uint16_t ar_op; // opcode
34     uint8_t ar_sha[ETH_ALEN]; // sender hardware address
35     uint8_t ar_spa[IPV4_ALEN]; // sender protocol address
36     uint8_t ar_tha[ETH_ALEN]; // target hardware address
37     uint8_t ar_tpa[IPV4_ALEN]; // target protocol address
38 } __attribute__ ((__packed__));
39 
40 class DhcpArpChecker {
41 public:
42     DhcpArpChecker();
43     ~DhcpArpChecker();
44     bool Start(std::string& ifname, std::string& hwAddr, std::string& senderIp, std::string& targetIp);
45     void Stop();
46     bool DoArpCheck(int32_t timeoutMillis, bool isFillSenderIp, uint64_t &timeCost);
47     void GetGwMacAddrList(int32_t timeoutMillis, bool isFillSenderIp, std::vector<std::string>& gwMacLists);
48 
49 private:
50     bool SetArpPacket(ArpPacket& arpPacket, bool isFillSenderIp);
51     int32_t CreateSocket(const char *iface, uint16_t protocol);
52     int32_t SendData(uint8_t *buff, int32_t count, uint8_t *destHwaddr);
53     int32_t RecvData(uint8_t *buff, int32_t count, int32_t timeoutMillis);
54     int32_t CloseSocket(void);
55     bool SetNonBlock(int32_t fd);
56     void SaveGwMacAddr(std::string gwMacAddr, std::vector<std::string>& gwMacLists);
57 private:
58     bool m_isSocketCreated;
59     struct in_addr m_localIpAddr;
60     struct in_addr m_targetIpAddr;
61     uint8_t m_localMacAddr[ETH_ALEN];
62     uint8_t m_l2Broadcast[ETH_ALEN];
63     int32_t m_socketFd;
64     uint16_t m_ifaceIndex;
65     uint16_t m_protocol;
66 };
67 }
68 }
69 #endif
70