即使启用了DHCP客户端，如何使用固定的默认IP立即启动接口？

我使用的是和声2.03b。对于我的网络接口，我使用DHCP客户端连同一个回退到一个固定的默认IP地址。通常，当网络接口被初始化或者当它正在进行NETWON和NetUp来改变配置时，它首先尝试通过DHCP获得IP地址。如果它没有得到一个IP，它等待大约10秒，直到它开始使用固定默认IP地址。在此之前，它没有地址，而不是这种行为，我希望网络接口总是可以立即使用固定的默认回退IP地址。然后几秒钟后，如果收到了一个提议，它就应该从DHCP租约地址转换为IP。我可以想到四种方法：方法1——TCPIpH.DHCPyEnable（）：不使用TCPipPixPixStAcKyNETUP（）。然后等待，直到TCPipIsStaskStaseUs（）返回SysStasuSuxRead和TCPIpHyStaskNeTestUp（Neth:=）真。之后调用TCPIpH.dHCPyEnable（）。（也请参阅TCPIpH.DHCPYEnable（）的成功要求是什么？）方法2：TCPIpHyStaskIpdialAlsieIe（）或TCPIpHyStaskYNETUP（）通常使用TcPIPpNETWorksObjultDHCPUcliton启动标记。然后等待，直到TCPipIsStaskStaseUs（）返回SysStasuSuxRead和TCPIpHyStaskNeTestUp（Neth:=）真。之后，调用TCPIPSISTACKNETWorkAddiSsSSET（）来设置固定的默认地址。方法3——TCPIpH.DHCPitimeOutt和TCPIpH.DHCPUIITHEFLYTMO：在10到0中更改StRySCONFIG.H（或MHC）中的TCPIpH.DHCPUTIOUT。在StaskIn.c中，它将将TCPIPDHCIPITATA.DHCPTMO设置为TCPIpH.DHCPUTIMOUT。但是，在函数中的DHCP。C中，有一个检查：要么我必须删除那个检查，要么我也必须将TCPIpH.DHCPGiNITHiFieltTMO更改为0。这在DHCPU.Buy.h中定义，我需要编辑。更改后的DHCPTMO导致O.DHCPCHECKRUNFECVER EVER（）立即发送TCPIPStAdxAddiSersServEvices（PNETIF、TCPIPSHSTACKADADESRSX Service EXDHCPC、TCPIPPSTACKYADADESRSX Service EVER RUNIORIVER），它设置了固定默认IP。方法4：TCPIpH.DHCPIRealEdvestTimeOutSoT（）：直接在TCPIpH栈之后SyPrimalIsIZE（）或TCPIPPSTACKYNETUP（）调用TCPIpH.DHCPIQuestEtTimeOutSuter（）。但是，TCPIpH.DHCPIQuestTimeOutSoT（）要求IntTMO是一个值，它不是零：因此，这将要求我删除DHCP.c中的IntTMO的检查。更改的DHCPTMO导致O.DHCPCHECKRUNFACKEVER（）立即发送一个TCPIPSISTACKADADESServServEvices（PNETIF，TCPIPSYSTACKADADESRSSER）VICEYDHCPC，TCPIPSISTACKADADRESS1 Service EVETIGRUNIORIVER，它设置固定默认IP。问题：-对于每种方法：这个想法是正确的吗？是否缺少一些细节（例如额外的检查）？还是不应该这样工作？-是否有另一种方法使接口立即与固定默认IP地址一起出现？-你会推荐哪种方法，为什么？



      以下为原文

    I'm using HARMony 2.03b. For my network interface I use the DHCP client together with a fallback to a fixed default IP address. Normally when the network interface is initialized or when it is doing a NetDown and NetUp to change the config, it tries first to get an IP address via DHCP. If it doesn't get an IP it waits for about 10 seconds until it starts using the fixed default IP address. Before that, it doesn't have an address.

Instead of this behavior I would like to have the network interface always immediately available with the fixed default fallback IP address. And then a few seconds later it should change to the IP from the DHCP lease address if you have received an offer.

I can think of four ways of doing this:

Method 1 - TCPIP_DHCP_Enable():
Do TCPIP_STACK_Initialize() or TCPIP_STACK_NetUp() without the TCPIP_NETWORK_CONFIG_DHCP_CLIENT_ON startFlag. Then wait until TCPIP_STACK_Status() returns SYS_STATUS_READY and TCPIP_STACK_NetIsUp(netH) == true. And after that call TCPIP_DHCP_Enable().
(see also thread What are the requirements for TCPIP_DHCP_Enable() to succeed? )

Method 2 - TCPIP_STACK_NetworkAddressSet():
Do TCPIP_STACK_Initialize() or TCPIP_STACK_NetUp() normally with the TCPIP_NETWORK_CONFIG_DHCP_CLIENT_ON startFlag. Then wait until TCPIP_STACK_Status() returns
SYS_STATUS_READY and TCPIP_STACK_NetIsUp(netH) == true. Directly after that call TCPIP_STACK_NetworkAddressSet() to set the fixed default address.

Method 3 - TCPIP_DHCP_TIMEOUT and TCPIP_DHCP_INIT_FAIL_TMO:
Change TCPIP_DHCP_TIMEOUT in system_config.h (or MHC) from 10 to 0. In system_init.c it will set tcpipDHCPInitData.dhcpTmo to TCPIP_DHCP_TIMEOUT. However, in dhcp.c in function TCPIP_DHCP_Initialize() there is a check:
// use a safe value for the fail timeout
pClient->tOpFailTmo = (pDhcpConfig->dhcpTmo < 1) ? TCPIP_DHCP_INIT_FAIL_TMO : (uint16_t)pDhcpConfig->dhcpTmo;
Because of this either I would have to remove that check, or I would also have to change TCPIP_DHCP_INIT_FAIL_TMO to 0. This is defined in dhcp_private.h which I would need to edit.
The changed dhcpTmo causes _DHCPCheckRunFailEvent() to send out immediately an TCPIP_STACK_AddressServiceEvent(pNetIf, TCPIP_STACK_ADDRESS_SERVICE_DHCPC, TCPIP_STACK_ADDRESS_SERVICE_EVENT_RUN_FAIL), which sets the fixed default IP.

Method 4 - TCPIP_DHCP_RequestTimeoutSet():
Directly after TCPIP_STACK_Initialize() or TCPIP_STACK_NetUp() call TCPIP_DHCP_RequestTimeoutSet(). However, TCPIP_DHCP_RequestTimeoutSet() requires initTmo to be a
value, which is not zero:
bool TCPIP_DHCP_RequestTimeoutSet(TCPIP_NET_HANDLE hNet, uint16_t initTmo, uint16_t dhcpBaseTmo)
{
    TCPIP_NET_IF* pNetIf = _TCPIPStackHandleToNetUp(hNet);
    if(DHCPClients && pNetIf && initTmo)
    {
        DHCP_CLIENT_VARS* pClient = DHCPClients + TCPIP_STACK_NetIxGet(pNetIf);
        pClient->tOpFailTmo = initTmo;
So this would require me to remove the check for initTmo in dhcp.c.
The changed dhcpTmo causes _DHCPCheckRunFailEvent() to send out immediately an TCPIP_STACK_AddressServiceEvent(pNetIf, TCPIP_STACK_ADDRESS_SERVICE_DHCPC, TCPIP_STACK_ADDRESS_SERVICE_EVENT_RUN_FAIL), which sets the fixed default IP.

Questions:
- For each of the methods: Is the idea correct? Are some details (e.g. additional checks) missing? Or is it not supposed to work like that?
- Is there another method to make the interface come up immediately with the fixed default IP address?
- Which of the methods would you recommend and why?