管理ifaddrs以及在Swift中返回MAC地址

func getIFAddresses() -> [String] {


print("GET IF ADDRESSSE")

var addresses = [String]()

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

    print("getifaddrs(getifaddrs)")

    // 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

        print("flags(flags)")
        print("addr(addr)")

        // 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) {

                print("addr.sa_family(addr.sa_family)")

                // Convert interface address to a human readable string:
                var hostname = [CChar](count: Int(NI_MAXHOST),repeatedValue: 0)

                print("hostname(hostname)")

                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)
    print("freeifaddrs(freeifaddrs)")
}
print("ADDRESSES (addresses)")
return addresses

(备注/澄清：这是对“管理ifaddrs以及在Swift中返回MAC地址”和“是否有可能从 How to get Ip address in swift修改代码以返回MAC地址”的问题的答案).
这不是“检索连接到我的路由器的所有IP”的解决方案
问题正文中也提到了这一点.)

这是返回的引用代码的扩展
本地(up和running)接口为
一个(接口名称,IP地址,MAC地址)元组的数组.
从AF_LINK类型的接口检索MAC地址
它们在接口列表中存储为sockaddr_dl结构.
这是一个可变长度的结构,Swift的严格类型系统使一些指针杂乱成为必要.

重要提示：此代码适用于在Mac计算机上运行.
它无法在iOS设备上获取MAC地址.
iOS有意将“02：00：00：00：00：00”作为硬件地址返回
出于隐私原因,请参阅所有接口,例如
Trouble with MAC address in iOS 7.0.2.)

func getInterfaces() -> [(name : String,addr: String,mac : String)] {

    var addresses = [(name : String,mac : String)]()
    var nameToMac = [ String : 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 flags = Int32(ptr.memory.ifa_flags)
            let addr = ptr.memory.ifa_addr

            if let name = String.fromCString(ptr.memory.ifa_name)  {

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

                    if addr.memory.sa_family == UInt8(AF_LINK) {
                        // Get MAC address from sockaddr_dl structure and store in nameToMac dictionary:
                        let dl = UnsafePointer<sockaddr_dl>(ptr.memory.ifa_addr)
                        let lladdr = UnsafeBufferPointer(start: UnsafePointer<Int8>(dl) + 8 + Int(dl.memory.sdl_nlen),count: Int(dl.memory.sdl_alen))
                        if lladdr.count == 6 {
                            nameToMac[name] = lladdr.map { String(format:"%02hhx",$0)}.joinWithSeparator(":")
                        }
                    }

                    if addr.memory.sa_family == UInt8(AF_INET) || addr.memory.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.memory.sa_len),NI_NUMERICHOST) == 0) {
                            if let address = String.fromCString(hostname) {
                                addresses.append( (name: name,addr: address,mac : "") )
                            }
                        }
                    }
                }
            }
        }
        freeifaddrs(ifaddr)
    }

    // Now add the mac address to the tuples:
    for (i,addr) in addresses.enumerate() {
        if let mac = nameToMac[addr.name] {
            addresses[i] = (name: addr.name,addr: addr.addr,mac : mac)
        }
    }

    return addresses
}

你必须添加

#include <ifaddrs.h>
#include <net/if_dl.h>

到桥接头文件进行编译.

用法示例：

for addr in getInterfaces() {
   print(addr)
}
// ("en0","fe80::1234:7fff:fe2e:8765%en0","a9:55:6f:2e:57:78")
// ("en0","192.168.2.108","a9:55:6f:2e:57:78")
// ...

更新Swift 3(Xcode 8)：

func getInterfaces() -> [(name : String,mac : String)]()
    var nameToMac = [ String: String ]()

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

    // For each interface ...
    for ptr in sequence(first: firstAddr,next: { $0.pointee.ifa_next }) {
        let flags = Int32(ptr.pointee.ifa_flags)
        if let addr = ptr.pointee.ifa_addr {
            let name = String(cString: ptr.pointee.ifa_name)

            // Check for running IPv4,IPv6 interfaces. Skip the loopback interface.
            if (flags & (IFF_UP|IFF_RUNNING|IFF_LOOPBACK)) == (IFF_UP|IFF_RUNNING) {
                switch Int32(addr.pointee.sa_family) {
                case AF_LINK:
                    // Get MAC address from sockaddr_dl structure and store in nameToMac dictionary:
                    addr.withMemoryRebound(to: sockaddr_dl.self,capacity: 1) { dl in
                        dl.withMemoryRebound(to: Int8.self,capacity: 8 + Int(dl.pointee.sdl_nlen + dl.pointee.sdl_alen)) {
                            let lladdr = UnsafeBufferPointer(start: $0 + 8 + Int(dl.pointee.sdl_nlen),count: Int(dl.pointee.sdl_alen))
                            if lladdr.count == 6 {
                                nameToMac[name] = lladdr.map { String(format:"%02hhx",$0)}.joined(separator: ":")
                            }
                        }
                    }
                case AF_INET,AF_INET6:
                    // Convert interface address to a human readable string:
                    var hostname = [CChar](repeating: 0,count: Int(NI_MAXHOST))
                    if (getnameinfo(addr,socklen_t(addr.pointee.sa_len),NI_NUMERICHOST) == 0) {
                        let address = String(cString: hostname)
                        addresses.append( (name: name,mac : "") )
                    }
                default:
                    break
                }
            }
        }
    }

    freeifaddrs(ifaddr)

    // Now add the mac address to the tuples:
    for (i,addr) in addresses.enumerated() {
        if let mac = nameToMac[addr.name] {
            addresses[i] = (name: addr.name,mac : mac)
        }
    }

    return addresses
}