Swift – Get device’s WIFI IP Address

According to several SO threads (e.g. What exactly means iOS networking interface name? what’s pdp_ip ? what’s ap?), the WiFi interface on an iOS device always has then name “en0”.

Your code (which seems to be what I answered at How to get Ip address in swift 🙂 retrieves a list of the IP addresses of all running network interfaces. It can easily be modified to return only the IP address
of the “en0” interface, and actually that is what I originally had
answered at that thread (and this is just a Swift translation of the
answer to how to get ip address of iphone programmatically):

// Return IP address of WiFi interface (en0) as a String, or `nil`
func getWiFiAddress() -> String? {
    var address : String?

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

        // For each interface ...
        var ptr = ifaddr
        while ptr != nil {
            defer { ptr = ptr.memory.ifa_next }

            let interface = ptr.memory

            // Check for IPv4 or IPv6 interface:
            let addrFamily = interface.ifa_addr.memory.sa_family
            if addrFamily == UInt8(AF_INET) || addrFamily == UInt8(AF_INET6) {

                // Check interface name:
                if let name = String.fromCString(interface.ifa_name) where name == "en0" {

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

    return address
}

Usage:

if let addr = getWiFiAddress() {
    print(addr)
} else {
    print("No WiFi address")
}

---

Update for Swift 3: In addition to adopting the code to the
many changes in Swift 3,
iterating over all interfaces can now use the new generalized
sequence() function:

Do NOT forget to add #include <ifaddrs.h> in your bridging header

// Return IP address of WiFi interface (en0) as a String, or `nil`
func getWiFiAddress() -> String? {
    var address : String?

    // Get list of all interfaces on the local machine:
    var ifaddr : UnsafeMutablePointer<ifaddrs>?
    guard getifaddrs(&ifaddr) == 0 else { return nil }
    guard let firstAddr = ifaddr else { return nil }

    // For each interface ...
    for ifptr in sequence(first: firstAddr, next: { $0.pointee.ifa_next }) {
        let interface = ifptr.pointee

        // Check for IPv4 or IPv6 interface:
        let addrFamily = interface.ifa_addr.pointee.sa_family
        if addrFamily == UInt8(AF_INET) || addrFamily == UInt8(AF_INET6) {

            // Check interface name:
            let name = String(cString: interface.ifa_name)
            if  name == "en0" {

                // Convert interface address to a human readable string:
                var hostname = [CChar](repeating: 0, count: Int(NI_MAXHOST))
                getnameinfo(interface.ifa_addr, socklen_t(interface.ifa_addr.pointee.sa_len),
                            &hostname, socklen_t(hostname.count),
                            nil, socklen_t(0), NI_NUMERICHOST)
                address = String(cString: hostname)
            }
        }
    }
    freeifaddrs(ifaddr)

    return address
}

---

For those of you who came looking for more than the WIFI IP you could modify this code a little

func getAddress(for network: Network) -> String? {
    var address: String?

    // Get list of all interfaces on the local machine:
    var ifaddr: UnsafeMutablePointer<ifaddrs>?
    guard getifaddrs(&ifaddr) == 0 else { return nil }
    guard let firstAddr = ifaddr else { return nil }

    // For each interface ...
    for ifptr in sequence(first: firstAddr, next: { $0.pointee.ifa_next }) {
        let interface = ifptr.pointee

        // Check for IPv4 or IPv6 interface:
        let addrFamily = interface.ifa_addr.pointee.sa_family
        if addrFamily == UInt8(AF_INET) || addrFamily == UInt8(AF_INET6) {

            // Check interface name:
            let name = String(cString: interface.ifa_name)
            if name == network.rawValue {

                // Convert interface address to a human readable string:
                var hostname = [CChar](repeating: 0, count: Int(NI_MAXHOST))
                getnameinfo(interface.ifa_addr, socklen_t(interface.ifa_addr.pointee.sa_len),
                            &hostname, socklen_t(hostname.count),
                            nil, socklen_t(0), NI_NUMERICHOST)
                address = String(cString: hostname)
            }
        }
    }
    freeifaddrs(ifaddr)

    return address
}

enum Network: String {
    case wifi = "en0"
    case cellular = "pdp_ip0"
    //... case ipv4 = "ipv4"
    //... case ipv6 = "ipv6"
}

Then we have access to the cellular IP as well.

guard let wifiIp = getAddress(for: .wifi) else { return }

&

guard let cellularIp = getAddress(for: .cellular) else { return }