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#ifndef NETSYS_CLAT_UTILS_H
16#define NETSYS_CLAT_UTILS_H
17
18#include <linux/if_tun.h>
19#include <netinet/icmp6.h>
20#include <netinet/in.h>
21#include <netinet/ip6.h>
22#include <string>
23#include <sys/uio.h>
24
25#include "clat_constants.h"
26#include "inet_addr.h"
27
28namespace OHOS {
29namespace nmd {
30using namespace OHOS::NetManagerStandard;
31typedef struct {
32    std::string v6Iface;
33    std::string tunIface;
34    INetAddr v4Addr;
35    INetAddr v6Addr;
36    std::string nat64PrefixStr;
37    int tunFd;
38    int readSock6;
39    int writeSock6;
40} ClatdTracker;
41
42typedef struct {
43    ip6_hdr v6Header;
44    nd_neighbor_solicit ns;
45    uint8_t nonceOptType;
46    uint8_t nonceOptLen;
47    uint8_t nonce[6];
48} ClatdDadPacket;
49
50typedef struct {
51    __u8 flags;
52    __u8 gsoType;
53    __u16 hdrLen;     /* Ethernet + IP + tcp/udp hdrs */
54    __u16 gsoSize;    /* Bytes to append to hdr_len per frame */
55    __u16 csumStart;  /* Position to start checksumming from */
56    __u16 csumOffset; /* Offset after that to place checksum */
57} virtioNetHdr;
58
59typedef struct {
60    virtioNetHdr vnet;
61    uint8_t payload[CLAT_DATA_LINK_HDR_LEN + CLAT_MAX_MTU];
62    char pad; // +1 to make packet truncation obvious
63} ClatdReadV6Buf;
64
65typedef struct {
66    tun_pi tunProtocolInfo;
67    uint8_t payload[CLAT_MAX_MTU];
68    char pad; // +1 to make packet truncation obvious
69} ClatdReadTunBuf;
70
71typedef iovec ClatdPacket[CLATD_MAX];
72
73void FreeTunV4Addr(const std::string &v4AddrStr);
74int32_t SelectIpv4Address(const std::string &initV4AddrStr, int prefixLen, std::string &v4AddrStr);
75int32_t GenerateIpv6Address(const std::string &v6IfaceStr, const std::string &v4AddrStr, const std::string &prefix64Str,
76                            uint32_t mark, std::string &v6AddrStr);
77uint16_t CalChecksum(const void *data, int len);
78uint32_t AddChecksum(uint32_t sum, const void *data, int len);
79uint16_t Checksum32To16(uint32_t sum32);
80uint16_t AdjustChecksum(uint16_t oldSum16, uint32_t oldSumHdr, uint32_t newSumHdr);
81int32_t CreateTunInterface(const std::string &tunIface, int &fd);
82int32_t OpenPacketSocket(int &readSock6);
83int32_t OpenRawSocket6(const uint32_t mark, int &writeSock6);
84int32_t ConfigureWriteSocket(const int sockFd, const std::string &v6Iface);
85int32_t ConfigureReadSocket(const int sockFd, const std::string &addrStr, int ifIndex);
86int32_t SetTunInterfaceAddress(const std::string &ifName, const std::string &tunAddr, int32_t prefix);
87
88} // namespace nmd
89} // namespace OHOS
90#endif