数据包隧道提供程序IOS中的动态DNS

Question

我有使用数据包隧道提供商的应用程序包含vpn配置关于隧道的设置有任何优雅合法的方式可以通过设备使用的dns(wifi、4g等(将其更改为动态

let dnsSettings=NEDNSettings(服务器：[8.8.8](

tunnelNetworkSettings.dnSettings=dnsSettings

Answer 1

您可以使用以下代码获取系统DNS服务器

static func getSystemDnsList() -> ([String]/*IPV4*/, [String]/*IPV6*/) {
var dnsListIPV4 = [String]()
var dnsListIPV6 = [String]()
let structSize = MemoryLayout<__res_9_state>.size
let res = UnsafeMutablePointer<__res_9_state>.allocate(capacity: structSize)
let result = res_9_ninit(res)
if result == 0 {
let structSize = MemoryLayout<res_9_sockaddr_union>.size
let capacity = Int(res.pointee.nscount) * structSize
let addrUnion = UnsafeMutablePointer<res_9_sockaddr_union>.allocate(capacity: capacity)
res_9_getservers(res, addrUnion, res.pointee.nscount)
for i in 0..<Int(res.pointee.nscount) {
if addrUnion[i].sin.sin_family == AF_INET {
let ip = UnsafeMutablePointer<Int8>.allocate(capacity: Int(INET_ADDRSTRLEN))
var ipStringObject : String?
if let ipStr = inet_ntop(AF_INET, &(addrUnion[i].sin.sin_addr), ip, socklen_t(INET_ADDRSTRLEN)) {
ipStringObject = String(utf8String: ipStr)
}
var portStringObject : String?
let port = nTohs(addrUnion[i].sin.sin_port)
portStringObject = String(format: "%d", port)
if let ip = ipStringObject {
dnsListIPV4.append(ip)
}
} else if addrUnion[i].sin6.sin6_family == AF_INET6 {
let ip = UnsafeMutablePointer<Int8>.allocate(capacity: Int(INET6_ADDRSTRLEN))
var ipStringObject : String?
if let ipStr = inet_ntop(AF_INET6, &(addrUnion[i].sin6.sin6_addr), ip, socklen_t(INET6_ADDRSTRLEN)) {
ipStringObject = String(utf8String: ipStr)
}
var portStringObject : String?
let port = nTohs(addrUnion[i].sin6.sin6_port)
portStringObject = String(format: "%d", port)
if let ip = ipStringObject {
dnsListIPV6.append(ip)
}
}
}
res_9_nclose(res)
free(res)
}
return (dnsListIPV4, dnsListIPV6)
}