Swift - Get device's WIFI IP Address

Question

I need to get IP Address of iOS device in Swift. This is not a duplicate of other questions about this! I need to get only WiFi IP address, if there is no wifi ip address - I need to handle it. There are a few questions about it on Stack Overflow, but there are only functions that return ip addresses. For example (from How to get Ip address in swift):

func getIFAddresses() -> [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
}

Here I get 2 values - address from mobile internet(I think) and WiFi address I need. Is there any other way to get ONLY WiFi IP Address?

Answer 1

Swift 4.2 UIDevice extension that avoids force unwraps and supports cellular and wired ip addresses:

import UIKit

extension UIDevice {

    private struct InterfaceNames {
        static let wifi = ["en0"]
        static let wired = ["en2", "en3", "en4"]
        static let cellular = ["pdp_ip0","pdp_ip1","pdp_ip2","pdp_ip3"]
        static let supported = wifi + wired + cellular
    }

    func ipAddress() -> String? {
        var ipAddress: String?
        var ifaddr: UnsafeMutablePointer<ifaddrs>?

        if getifaddrs(&ifaddr) == 0 {
            var pointer = ifaddr

            while pointer != nil {
                defer { pointer = pointer?.pointee.ifa_next }

                guard
                    let interface = pointer?.pointee,
                    interface.ifa_addr.pointee.sa_family == UInt8(AF_INET) || interface.ifa_addr.pointee.sa_family == UInt8(AF_INET6),
                    let interfaceName = interface.ifa_name,
                    let interfaceNameFormatted = String(cString: interfaceName, encoding: .utf8),
                    InterfaceNames.supported.contains(interfaceNameFormatted)
                    else { continue }

                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)

                guard
                    let formattedIpAddress = String(cString: hostname, encoding: .utf8),
                    !formattedIpAddress.isEmpty
                    else { continue }

                ipAddress = formattedIpAddress
                break
            }

            freeifaddrs(ifaddr)
        }

        return ipAddress
    }

}

Usage:

UIDevice.current.ipAddress()

Answer 2

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
}

Answer 3

If you want only IPv4 response as output just modify the solution by Martin R.

 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) {  // **ipv6 committed
        if addrFamily == UInt8(AF_INET){

            // 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
}

Usage:

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

Answer 4

Create bridging header and Include #include <ifaddrs.h> in it.

then write this method

func getIFAddresses() -> [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
}

when I call this method in my viewController like var arr : NSArray = self.getIFAddresses() I get perfect response in my console like

IP :( "10.0.0.94" )

from this array you can access it where ever u want. Hope it helps

Answer 5

All the answers here gives only ip address for wifi and not wired or cellular. Following snippet can be used for wifi/wired/cellular case:

func getIPAddressForCellOrWireless()-> String? {

    let WIFI_IF : [String] = ["en0"]
    let KNOWN_WIRED_IFS : [String] = ["en2", "en3", "en4"]
    let KNOWN_CELL_IFS : [String] = ["pdp_ip0","pdp_ip1","pdp_ip2","pdp_ip3"]

    var addresses : [String : String] = ["wireless":"",
                                         "wired":"",
                                         "cell":""]

    var address: String?
    var ifaddr: UnsafeMutablePointer<ifaddrs>? = nil
    if getifaddrs(&ifaddr) == 0 {

        var ptr = ifaddr
        while ptr != nil {
            defer { ptr = ptr?.pointee.ifa_next } // memory has been renamed to pointee in swift 3 so changed memory to pointee

            let interface = ptr?.pointee
            let addrFamily = interface?.ifa_addr.pointee.sa_family
            if addrFamily == UInt8(AF_INET) || addrFamily == UInt8(AF_INET6) {

                if let name: String = String(cString: (interface?.ifa_name)!), (WIFI_IF.contains(name) || KNOWN_WIRED_IFS.contains(name) || KNOWN_CELL_IFS.contains(name)) {

                    // String.fromCString() is deprecated in Swift 3. So use the following code inorder to get the exact IP Address.
                    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)
                    if WIFI_IF.contains(name){
                        addresses["wireless"] =  address
                    }else if KNOWN_WIRED_IFS.contains(name){
                        addresses["wired"] =  address
                    }else if KNOWN_CELL_IFS.contains(name){
                        addresses["cell"] =  address
                    }
                }

            }
        }
    }
    freeifaddrs(ifaddr)

    var ipAddressString : String?
    let wirelessString = addresses["wireless"]
    let wiredString = addresses["wired"]
    let cellString = addresses["cell"]
    if let wirelessString = wirelessString, wirelessString.count > 0{
        ipAddressString = wirelessString
    }else if let wiredString = wiredString, wiredString.count > 0{
        ipAddressString = wiredString
    }else if let cellString = cellString, cellString.count > 0{
        ipAddressString = cellString
    }
    return ipAddressString
}

Answer 6

You can fetch IP address using the code below:

Note : I've used reachability so that it captures new IP address in case WiFi is changed to another.

1. In Podfile file

   pod 'ReachabilitySwift' and then install pod

2. In AppDelegate.swift file import ReachabilitySwift

   Note : If it prompts an error that Could not find ReachabilitySwift module then simply copy and paste this. It works!

3. didFinishLaunchingOptions function

   NotificationCenter.default.addObserver(self, selector: #selector(self.reachabilityChanged), name: ReachabilityChangedNotification, object: reachability)
   
   do{
       try reachability.startNotifier()
   }
   catch {
       print("could not start reachability notifier")
   } 
   

4. Then copy paste below code in AppDelegate file

   func reachabilityChanged(note: NSNotification) {
   
       let reachability = note.object as! Reachability
   
       if reachability.isReachable {
           if reachability.isReachableViaWiFi {
               print("Reachable via WiFi")
           } else {
               print("Reachable via Cellular")
           }
   
           setIPAddress()
       } else {
           ipAddress = "" // No IP captures
           print("Network not reachable")
       }
   }
   
   func setIPAddress() {
       if let addr = self.getWiFiAddress() {
           print("ipAddress : \(addr)")
           ipAddress = addr
       } else {
           ipAddress = "" // No IP captures
           print("No WiFi address")
       }
   }
   
   // 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 addr = interface.ifa_addr.pointee
                   var hostname = [CChar](repeating: 0, count: Int(NI_MAXHOST))
                   getnameinfo(&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
   }
   

5. Add this in Bridging-Header file #include<ifaddrs.h>

   In case you don't have this file then you can create it Check this link

6.

func applicationWillEnterForeground(_ application: UIApplication) {
        // Post notification
        NotificationCenter.default.post(name: ReachabilityChangedNotification, object: reachability)
        // Called as part of the transition from the background to the active state; here you can undo many of the changes made on entering the background.
    }

7. If you want to remove observer, then:

   reachability.stopNotifier()  
   
   NSNotificationCenter.defaultCenter().removeObserver(self,name: ReachabilityChangedNotification,object: reachability)