How to get IPhone's Public IP Address without using a third party url

问题

For my project, i need to get the IPhone's Public IP address, there are so many examples available, which show public IP address by using external / third party URL. I just want to know how to extract IPhones's IP Address without help of using another url.

Note :- I used This one but shows only the local IP address , i need public IP address

   func getIPAddress() -> [String] {
    var addresses = [String]()

    // Get list of all interfaces on the local machine:
    var ifaddr : UnsafeMutablePointer<ifaddrs> = nil
    if getifaddrs(&ifaddr) == 0 {

        // For each interface ...
        for (var ptr = ifaddr; ptr != nil; ptr = ptr.memory.ifa_next) {
            let flags = Int32(ptr.memory.ifa_flags)
            var addr = ptr.memory.ifa_addr.memory

            // Check for running IPv4, IPv6 interfaces. Skip the loopback interface.
            if (flags & (IFF_UP|IFF_RUNNING|IFF_LOOPBACK)) == (IFF_UP|IFF_RUNNING) {
                if addr.sa_family == UInt8(AF_INET) || addr.sa_family == UInt8(AF_INET6) {

                    // Convert interface address to a human readable string:
                    var hostname = [CChar](count: Int(NI_MAXHOST), repeatedValue: 0)
                    if (getnameinfo(&addr, socklen_t(addr.sa_len), &hostname, socklen_t(hostname.count),
                        nil, socklen_t(0), NI_NUMERICHOST) == 0) {
                            if let address = String.fromCString(hostname) {
                                addresses.append(address)
                            }
                    }
                }
            }
        }
        freeifaddrs(ifaddr)
    }

    return addresses
}

I used this one in my swift project by using a header file, it generates Local IP

回答1:

import Darwin

var hostName = [Int8](count: 255, repeatedValue: 0)
gethostname(&hostName, hostName.count)

var hints = addrinfo()
var res = UnsafeMutablePointer<addrinfo>()
var p = UnsafeMutablePointer<addrinfo>()
var p4 = UnsafeMutablePointer<sockaddr_in>()
var p6 = UnsafeMutablePointer<sockaddr_in6>()

hints.ai_flags = AI_ALL
hints.ai_family = PF_UNSPEC
hints.ai_socktype = SOCK_STREAM
var ipstr = [CChar](count: Int(INET6_ADDRSTRLEN), repeatedValue: 0)

print("List of IP addresses on host \(String.fromCString(hostName)!)\n")

if getaddrinfo( hostName, "0", &hints, &res) == 0 {

    var ipFamily = ""
    var s: Int32 = 0
    var port: in_port_t = 0
    for(p = res; p != nil; p = p.memory.ai_next) {

        switch p.memory.ai_family {
        case PF_INET:
            p4 = UnsafeMutablePointer<sockaddr_in>(p.memory.ai_addr)
            inet_ntop(AF_INET, &p4.memory.sin_addr, &ipstr, socklen_t(INET6_ADDRSTRLEN))
            ipFamily = "IPv4"
            port = p4.memory.sin_port.bigEndian
        case PF_INET6:
            p6 = UnsafeMutablePointer<sockaddr_in6>(p.memory.ai_addr)
            inet_ntop(AF_INET6, &p6.memory.sin6_addr, &ipstr, socklen_t(INET6_ADDRSTRLEN))
            ipFamily = "IPv6"
            port = p6.memory.sin6_port.bigEndian
        default:

            break
        }
        print("\t\(ipFamily):", String.fromCString(ipstr)!)

    }
    // free unmanaged memmory !!!!!
    freeaddrinfo(res)
}

prints on my own computer

List of IP addresses on host Ivos-MacBook.local

    IPv6: fe80::225:ff:fe40:9c72
    IPv6: 2a02:130:200:1350:225:ff:fe40:9c72
    IPv4: 192.168.1.106

for external IP, you need help of external service (not swift specific :-))

来源：https://stackoverflow.com/questions/33494983/how-to-get-iphones-public-ip-address-without-using-a-third-party-url