DnsQueryConfig，此API的功能是，获取本机的DNS，API的官方文档在这：
```
https://docs.microsoft.com/en-us/windows/win32/api/windns/nf-windns-dnsqueryconfig
```
在项目`github.com/kbinani/win`下新建了文件`dnsapi.go`，代码如下：
```go
// This file was automatically generated by https://github.com/kbinani/win/blob/generator/internal/cmd/gen/gen.go
// go run internal/cmd/gen/gen.go
// +build windows
package win
import "unsafe"
var (
// Library
libdnsapi uintptr
// function
dnsQueryConfig uintptr
)
type DNS_CONFIG_TYPE uint32
type IP4_ARRAY struct {
AddrCount DWORD
IP4_ADDRESS [0]IP_ADDRESS_STRING
}
type PIP4_ARRAY *IP4_ARRAY
func init(){
// Library
libdnsapi = doLoadLibrary("Dnsapi.dll")
// Functions
dnsQueryConfig = doGetProcAddress(libdnsapi, "DnsQueryConfig")
}
func DnsQueryConfig(config DNS_CONFIG_TYPE, flag DWORD, pwsAdapterName PCWSTR, pReserved PVOID, pBuffer PVOID, pBufLen DWORD_PTR) int32 {
ret1 := syscall6(dnsQueryConfig,
6,
uintptr(unsafe.Pointer(&config)),
uintptr(unsafe.Pointer(&flag)),
uintptr(unsafe.Pointer(pwsAdapterName)),
uintptr(pReserved),
uintptr(pBuffer),
uintptr(unsafe.Pointer(pBufLen)),
)
return int32(ret1)
}
```
在自己的项目中，代码如下：
```go
package main
import (
"fmt"
"github.com/kbinani/win"
"unsafe"
)
func main(){
// func DnsQueryConfig(config DNS_CONFIG_TYPE, flag DWORD, pwsAdapterName PCWSTR, pReserved PVOID, pBuffer PVOID, pBufLen DWORD_PTR) int32 {
config := win.DNS_CONFIG_TYPE(6)
flag := win.DWORD(0)
pwsAdapterName := win.PCWSTR(nil)
pReserved := win.PVOID(unsafe.Pointer(nil))
buffer := win.IP4_ARRAY{}
a := win.PVOID(unsafe.Pointer(&buffer))
l := uint32(unsafe.Sizeof(buffer))
pBufLen := win.DWORD_PTR(unsafe.Pointer(&l))
//bufferp := win.From
r := win.DnsQueryConfig(config, flag, pwsAdapterName, pReserved, a, pBufLen)
fmt.Println(r)
}
```
运行的结果始终返回代码87：
```shell
87
Process finished with exit code 0
```
我查了下此87代表的意思是`无效的参数`：
```c++
#define ERROR_INVALID_PARAMETER 87L
```
还请大神指点，哪儿出错了，非常感谢
-----
这个问题解决了：
```go
package main
import (
"fmt"
"golang.org/x/sys/windows"
"net"
"strings"
"unsafe"
)
const (
DnsConfigDnsServerList int32 = 6
)
type char byte
type IpAddressString struct {
DNS [4 * 10]char
}
type Ip4Array struct {
AddrCount uint32
Ip4Address [1]IpAddressString
}
func main() {
fmt.Println(dns())
}
func dns() []string {
dns := []string{}
dnsapi := windows.NewLazyDLL("Dnsapi.dll")
dnsQuery := dnsapi.NewProc("DnsQueryConfig")
bufferBytes := make([]byte, 60)
loop:
buffer := (*Ip4Array)(unsafe.Pointer(&bufferBytes[0]))
blen := len(bufferBytes)
r1, _, _ := dnsQuery.Call(uintptr(DnsConfigDnsServerList), uintptr(0), uintptr(0), uintptr(0), uintptr(unsafe.Pointer(&bufferBytes[0])), uintptr(unsafe.Pointer(&blen)))
if r1 == 234 {
bufferBytes = make([]byte, blen)
goto loop
} else if r1 == 0 {
} else {
return dns
}
for i := uint32(1); i <= buffer.AddrCount; i++ {
right := i * 4
left := right - 4
tmpChars := buffer.Ip4Address[0].DNS[left:right]
tmpStr := []string{}
for j := 0; j < len(tmpChars); j++ {
tmpStr = append(tmpStr, fmt.Sprint(tmpChars[j]))
}
tmpDNS := strings.Join(tmpStr, ".")
pDns := net.ParseIP(tmpDNS)
if pDns == nil {
continue
}
if !pDns.IsGlobalUnicast() {
continue
}
dns = append(dns, tmpDNS)
}
return dns
}
```
运行结果：
```
[10.198.1.1 114.114.114.114 114.114.115.115 8.8.8.8 218.85.157.99 218.85.152.99]
```
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