Swift和C混合Socket编程实现简单的ping命令&主机发现

Swift和C混合Socket编程实现简单的ping命令

这个是用Mac下的Network Utility工具实现ping命令,用Wireshark抓取的ICMP数据包:

发送ICMP数据包内容

接受ICMP数据包内容

 

一.icmp结构

要真正了解ping命令实现原理，就要了解ping命令所使用到的TCP/IP协议。
ICMP(Internet
 Control 
Message,网际控制报文协议)是为网关和目标主机而提供的一种差错控制机制，使它们在遇到差错时能把错误报告给报文源发方。ICMP协议是IP层的
一个协议，但是由于差错报告在发送给报文源发方时可能也要经过若干子网，因此牵涉到路由选择等问题，所以ICMP报文需通过IP协议来发送。

ICMP数据报的数据发送前需要两级封装：首先添加ICMP报头形成ICMP报文，再添加IP报头形成IP数据报

各种ICMP报文的前32bits都是三个长度固定的字段：type类型字段(8位)、code代码字段(8位)、checksum校验和字段(16位)

8bits类型和8bits代码字段：一起决定了ICMP报文的类型。常见的有：
　　
　　类型8、代码0：回射请求。
　　
　　类型0、代码0：回射应答。
　　
　　类型11、代码0：超时。
　　
　　16bits校验和字段：包括数据在内的整个ICMP数据包的校验和，其计算方法和IP头部校验和的计算方法是一样的。

对于ICMP回射请求和应答报文来说，接下来是16bits标识符字段：用于标识本ICMP进程。
　　
最后是16bits序列号字段：用于判断回射应答数据报。

ICMP报文包含在IP数据报中，属于IP的一个用户，IP头部就在ICMP报文的前面

一个ICMP报文包括IP头部（20字节）、ICMP头部（8字节）和ICMP报文数据部分

 

ICMP报文格式,在Mac(Unix)下结构包含在ip_icmp.h中:

引入头文件#include //icmp数据包结构

struct icmp {
    u_char    icmp_type;        /* type of message, see below */
    u_char    icmp_code;        /* type sub code */
    u_short    icmp_cksum;        /* ones complement cksum of struct */
    union {
        u_char ih_pptr;            /* ICMP_PARAMPROB */
        struct in_addr ih_gwaddr;    /* ICMP_REDIRECT */
        struct ih_idseq {
            n_short    icd_id;
            n_short    icd_seq;
        } ih_idseq;
        int ih_void;

        /* ICMP_UNREACH_NEEDFRAG -- Path MTU Discovery (RFC1191) */
        struct ih_pmtu {
            n_short ipm_void;
            n_short ipm_nextmtu;
        } ih_pmtu;

        struct ih_rtradv {
            u_char irt_num_addrs;
            u_char irt_wpa;
            u_int16_t irt_lifetime;
        } ih_rtradv;
    } icmp_hun;
#define    icmp_pptr    icmp_hun.ih_pptr
#define    icmp_gwaddr    icmp_hun.ih_gwaddr
#define    icmp_id        icmp_hun.ih_idseq.icd_id
#define    icmp_seq    icmp_hun.ih_idseq.icd_seq
#define    icmp_void    icmp_hun.ih_void
#define    icmp_pmvoid    icmp_hun.ih_pmtu.ipm_void
#define    icmp_nextmtu    icmp_hun.ih_pmtu.ipm_nextmtu
#define    icmp_num_addrs    icmp_hun.ih_rtradv.irt_num_addrs
#define    icmp_wpa    icmp_hun.ih_rtradv.irt_wpa
#define    icmp_lifetime    icmp_hun.ih_rtradv.irt_lifetime
    union {
        struct id_ts {
            n_time its_otime;
            n_time its_rtime;
            n_time its_ttime;
        } id_ts;
        struct id_ip  {
            struct ip idi_ip;
            /* options and then 64 bits of data */
        } id_ip;
        struct icmp_ra_addr id_radv;
        u_int32_t id_mask;
        char    id_data[1];
    } icmp_dun;
#define    icmp_otime    icmp_dun.id_ts.its_otime
#define    icmp_rtime    icmp_dun.id_ts.its_rtime
#define    icmp_ttime    icmp_dun.id_ts.its_ttime
#define    icmp_ip        icmp_dun.id_ip.idi_ip
#define    icmp_radv    icmp_dun.id_radv
#define    icmp_mask    icmp_dun.id_mask
#define    icmp_data    icmp_dun.id_data
};

IP报文格式,在Mac(Unix)下结构包含在ip.h中:

引入头文件#include //ip数据包结构

struct ip {
#ifdef _IP_VHL
    u_char    ip_vhl;            /* version << 4 | header length >> 2 */
#else
#if BYTE_ORDER == LITTLE_ENDIAN
    u_int    ip_hl:4,        /* header length */
        ip_v:4;            /* version */
#endif
#if BYTE_ORDER == BIG_ENDIAN
    u_int    ip_v:4,            /* version */
        ip_hl:4;        /* header length */
#endif
#endif /* not _IP_VHL */
    u_char    ip_tos;            /* type of service */
    u_short    ip_len;            /* total length */
    u_short    ip_id;            /* identification */
    u_short    ip_off;            /* fragment offset field */
#define    IP_RF 0x8000            /* reserved fragment flag */
#define    IP_DF 0x4000            /* dont fragment flag */
#define    IP_MF 0x2000            /* more fragments flag */
#define    IP_OFFMASK 0x1fff        /* mask for fragmenting bits */
    u_char    ip_ttl;            /* time to live */
    u_char    ip_p;            /* protocol */
    u_short    ip_sum;            /* checksum */
    struct    in_addr ip_src,ip_dst;    /* source and dest address */
};

二.具体实现代码

//xSocketPing.c


#include "xSocketPing.h"

//statistics
void statistics(char* back){
    double percent = ((double)sendPacketNumber - (double)recvPacketNumber) / (double)sendPacketNumber * 100;
    sprintf(back, "---%s ping statistics---
%d packets trasmitted, %d packet received, %0.1f%% packet loss",inet_ntoa(dstAddr.sin_addr),sendPacketNumber,recvPacketNumber,percent);
}
//check sum
unsigned short checkSum(unsigned short *buffer, int size){
    unsigned long checkSum = 0;
    while (size > 1) {
        checkSum += *buffer++;
        size -= sizeof(unsigned short);//unsigned short is 2 bytes = 16 bits
    }
    //if size is odd number
    if (size == 1){
        checkSum += *(unsigned short *)buffer;
    }
    checkSum = (checkSum >> 16) + (checkSum & 0xFFFF);
    checkSum += (checkSum >> 16);
    return ~checkSum;
}

//calculate time difference
double timeSubtract(struct timeval *recvTimeStamp, struct timeval *sendTimeStamp){
    //calculate seconds
    long timevalSec = recvTimeStamp->tv_sec - sendTimeStamp->tv_sec;
    //calculate microsends
    long timevalUsec = recvTimeStamp->tv_usec - sendTimeStamp->tv_usec;
    
    //if microsends less then zero
    if (timevalUsec < 0) {
        timevalSec -= 1;
        timevalUsec = - timevalUsec;
    }
    return (timevalSec * 1000.0 + timevalUsec) / 1000.0;
}

//fill icmp packet and return size of packet
int fillPacket(int packetSequence){
    int packetSize = 0;
    struct icmp *icmpHeader = (struct icmp *)sendBuffer;
    
    icmpHeader->icmp_type = ICMP_ECHO;
    icmpHeader->icmp_code = 0;
    icmpHeader->icmp_cksum = 0;
    icmpHeader->icmp_id = pid;
    icmpHeader->icmp_seq = packetSequence;
    packetSize = dataSize + 8;
    tvSend = (struct timeval *)icmpHeader->icmp_data;
    gettimeofday(tvSend, NULL);//get current of time
    icmpHeader->icmp_cksum = checkSum((unsigned short *)icmpHeader, packetSize);
    return packetSize;
}

//send icmp packet to dstAddr
int sendPacket(int packetSequence){
    int packSize = 0;
    packSize = fillPacket(packetSequence);
    if ((sendto(socketfd, sendBuffer, packSize, 0, (struct sockaddr *)&dstAddr, sizeof(dstAddr))) < 0) {
        printf("Send icmp packet Error
");
        sendPacketNumber--;
        recvPacketNumber--;
        return -1;
    }
    return 0;
}

//setting ip address
void settingIP(){
    //initialize
    bzero(&dstAddr,sizeof(dstAddr));
    dstAddr.sin_family = AF_INET;
    dstAddr.sin_addr.s_addr = inet_addr(ipAddr);
}

//get current process id
void getPid(){
    pid = getpid();
}

//create socket
int createSocket(){
    //原始套接字SOCK_RAW需要使用root权限,所以改用SOCK_DGRAM
    if ((socketfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_ICMP)) < 0) {
        printf("Create Socket Error
");
        return -1;
    }
    return 0;
}

//setting socket
void settingSocket(int timeout){
    int size = 50 * 1024;
    //setting timeout seconds or you can set it by microseconds
    struct timeval timeOut;
    timeOut.tv_sec = timeout;
    //扩大套接字接收缓冲区到50K这样做主要为了减小接收缓冲区溢出的可能性,若无意中ping一个广播地址或多播地址,将会引来大量应答
    setsockopt(socketfd, SOL_SOCKET, SO_RCVBUF, &size, sizeof(size));
    setsockopt(socketfd, SOL_SOCKET, SO_RCVTIMEO, (char *)&timeOut, sizeof(timeOut));
}

//destory socket
void destorySocket(){
    close(socketfd);
}

//unpacket
void unPacket(char* packetBuffer,char* back, long size){
    struct ip *ipHeader = NULL;
    struct icmp *icmpHeader = NULL;
    
    double rtt;//往返时间
    int ipHeaderLength;//ip header length
    
    ipHeader = (struct ip *)packetBuffer;
    ipHeaderLength = ipHeader->ip_hl<<2;//求ip报头长度,即ip报头的长度标志乘4
    icmpHeader = (struct icmp *)(packetBuffer + ipHeaderLength);//越过IP头，point to ICMP header
    size -= ipHeaderLength;
    if (size < 8){
        back = "Unpacket Error:packet size minmum 8 bytes
";
    }
    
    if ((icmpHeader->icmp_type == ICMP_ECHOREPLY) && (icmpHeader->icmp_id == pid)) {
        tvSend = (struct timeval *)icmpHeader->icmp_data;
        gettimeofday(&tvRecv, NULL);
        //以毫秒为单位计算rtt
        rtt = timeSubtract(&tvRecv, tvSend);
        sprintf(back,"%ld bytes from %s: icmp_seq=%u ttl=%d time=%.1f ms
",size,inet_ntoa(recvAddr.sin_addr),icmpHeader->icmp_seq,ipHeader->ip_ttl,rtt);
    }else{
        back = "Unpacket Error
";
    }
}

//receive packet
void receivePacket(char* back){
    //claculate packet size
    int packetSize = sizeof(recvAddr);
    long size;
    if ((size = recvfrom(socketfd, recvBuffer, sizeof(recvBuffer), 0, (struct sockaddr *)&recvAddr, (socklen_t *)&packetSize)) < 0) {
        sprintf(back,"Receive timeout
");
        recvPacketNumber--;
    }else{
        gettimeofday(&tvRecv, NULL);
        //char temp[100] = {0};
        unPacket(recvBuffer, back, size);
        //printf("%s
",temp);
    }
}

void ping(char *ipAddress, int number, int timeout){
    int packetnumber = 0;
    ipAddr = ipAddress;
    sendPacketNumber = number;
    recvPacketNumber = number;
    
    settingIP();
    getPid();
    if (createSocket() != -1){
        settingSocket(timeout);
        printf("PING %s: %d bytes of data.
",ipAddress,dataSize);
        while(packetnumber < number){
            if (sendPacket(packetnumber) != -1){
                char back[100] = {0};
                receivePacket(back);
                printf("%s",back);
            }
            sleep(1);
            packetnumber++;
        }
        char back[100] = {0};
        statistics(back);
        printf("%s
",back);
        destorySocket();
    }
}

//xSocketPing.h

#ifndef xSocketPing_h
#define xSocketPing_h

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>//基本系统数据类型
#include <sys/socket.h>
#include <netinet/in.h>
//get current of time
#include <sys/time.h>
#include <arpa/inet.h>//inet_ntoa将一个IP转换成一个互联网标准点分格式的字符串
#include <unistd.h>//close(int)
#include <netdb.h>//定义了与网络有关的结构、变量类型、宏、函数等
//ip packet structure
#include <netinet/ip.h>
//icmp packet structure
#include <netinet/ip_icmp.h>

//time to live
int ttl = 64;
//icmp data size ,icmp header 8bytes,data size 56bytes,the maximum of packet size 64bytes
int dataSize = 56;
//packet number
int sendPacketNumber;
int recvPacketNumber;
//ip address
char * ipAddr;

//send packet of time
struct timeval *tvSend;
//receive packet of time
struct timeval tvRecv;

//Socket address, internet style.
//the destination address
struct sockaddr_in dstAddr;
//the receive address
struct sockaddr_in recvAddr;

//send icmp buffer
char sendBuffer[1024] = {0};
//receive icmp replay buffer
char recvBuffer[1024] = {0};

//the current process of id
int pid;
//socket
int socketfd = 0;


void statistics(char* back);
unsigned short checkSum(unsigned short *buffer, int size);
double timeSubtract(struct timeval *recvTimeStamp, struct timeval *sendTimeStamp);
int fillPacket(int packetSequence);
int sendPacket(int packetSequence);
void settingIP();
void getPid();
int createSocket();
void settingSocket(int timeout);
void destorySocket();
void unPacket(char* packetBuffer,char* back, long size);
void receivePacket(char* back);
void ping(char *ipAddress, int number, int timeout);


#endif /* xSocketPing_h */

//xSocketPing.swift

import Foundation

public class xSocketPing{
    
    private var ipAddress:String
    //default packet number 3 or you can setting it by yourself
    private var packetNumber:Int = 3
    private var timeout:Int = 1
    //refresh UI
    weak var delegate:refreshTextDelegate?

    init(ipAddress:String, delegate:refreshTextDelegate){
        self.ipAddress = ipAddress
        self.delegate = delegate
    }
    convenience init(ipAddress:String, packetNumber:Int, delegate:refreshTextDelegate){
        self.init(ipAddress: ipAddress,delegate: delegate)
        self.packetNumber = packetNumber
    }
    convenience init(ipAddress:String, packetNumber:Int, timeout:Int, delegate:refreshTextDelegate){
        self.init(ipAddress: ipAddress,packetNumber: packetNumber,delegate: delegate)
        self.timeout = timeout
    }
    
    public func xPing(){
        let tempIpAddress:UnsafeMutablePointer = UnsafeMutablePointer<Int8>((ipAddress as NSString).UTF8String)
        ipAddr = tempIpAddress
        sendPacketNumber = Int32(packetNumber)
        recvPacketNumber = Int32(packetNumber)
        
        settingIP()
        getPid()
        if createSocket() != -1 {
            settingSocket(Int32(timeout))
            let message:String = "PING (ipAddress): 56 bytes of data.
"
            refresh(message, speed: 0.0)
            //将String转换为UnsafeMutablePointer<CChar>,相当于char tempmessage[100]
            let tempmessage:UnsafeMutablePointer = UnsafeMutablePointer<CChar>.alloc(100)
            var packetsequence:Int = 0
            var speed:Float = 0.0
            
            while packetsequence < packetNumber {
                if sendPacket(Int32(packetsequence)) != -1 {
                    receivePacket(tempmessage)
                    //Calculate percentage
                    speed = (Float(packetNumber) - (Float(packetNumber) - Float(packetsequence))) / Float(packetNumber)
                    //将UnsafeMutablePointer<CChar>转换为String
                    refresh(String.fromCString(tempmessage)!, speed: speed)
                }
                sleep(1);
                packetsequence++
            }
            statistics(tempmessage)
            refresh(String.fromCString(tempmessage)!, speed: 1)
            destorySocket()
        }
    }
    
    func refresh(text:String, speed:Float){
        delegate?.refresh(text, speed: speed)
    }
    deinit{
        print("xSocketPing destory")
    }
}

//ViewController.swift

import UIKit

protocol refreshTextDelegate:NSObjectProtocol{
    func refresh(text:String, speed:Float)
}

class ViewController: UIViewController,refreshTextDelegate {

    @IBOutlet weak var xprogress: UIProgressView!
    @IBOutlet weak var xip: UITextField!
    @IBOutlet weak var xnumber: UITextField!
    @IBOutlet weak var xtext: UITextView!
    
    var number:Int = 3
    var ip:String = "192.168.1.1"
    
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        xtext.text = ""
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    
    @IBAction func xNumberChange(sender: UIStepper) {
        xnumber.text = "(Int(sender.value))"
        self.number = Int(sender.value)
    }
    
    @IBAction func beginPing(sender: UIButton) {
        sender.enabled = false
        xip.enabled = false
        xnumber.enabled = false
        
        xprogress.progress = 0
        xtext.text = ""
        
        let ip = xip.text
        if ip == ""{
            let alert = UIAlertView(title: "Error", message: "No IP Address", delegate: self, cancelButtonTitle: "OK")
            alert.show()
        }else{
            dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), {
                let ping:xSocketPing = xSocketPing(ipAddress: "(ip!)", packetNumber: self.number, delegate: self)
                ping.xPing()
            })
        }
        xnumber.enabled = true
        xip.enabled = true
        sender.enabled = true
    }
    
    
    func refresh(text:String, speed:Float) {
        dispatch_async(dispatch_get_main_queue(), {
            //更新进度条
            self.xprogress.progress = speed
            //更新UITextView,追加内容并滚动到最下面
            self.xtext.text.appendContentsOf(text)
            self.xtext.scrollRangeToVisible(NSMakeRange(self.xtext.text.characters.count, 0))
        })
    }
    override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
        self.view.endEditing(true)
    }
}

运行结果图:

 

 

使用Swift进行主机发现和MAC地址解析

贴出的都是核心代码,代码都有注释,全部代码可以在Github上下载.

主机发现基本原理:根据Stackoverflow上面的解释,应该是读取arp缓存表来获取MAC地址.(依旧不知道Fing是弄的,根据抓包来看是发送arp数据包来实现主机扫描的,但是又不能使用原始套接字,又不能获取本机MAC地址,没办法,只能继续研究下去了.如果有哪位大神知道,希望告知,谢谢.)

至于IP地址是使用getifaddrs函数来获取本机的所有网卡的信息:具体看Get all Ethernet information in Swift　　(返回的信息中包含了IP地址,子网掩码,广播地址.)

然后获取WiFi的SSID和BSSID:Get WIFI SSID and BSSID     

获取网卡信息和WiFi的信息我放到了一个类中方便调用.

class GetInterfaceInformation{
    
    /**
    get ethernet information about name,address,netmask,broadcast
    
    - returns: return Dictionary contain Ethernet name,ip address,netmask,broadcast
    */
    static func getInterfaceInformation() -> [String:[String]] {
        var information = [String:[String]]()
        
        var ifaddr:UnsafeMutablePointer<ifaddrs> = nil
        //retrieve the current interface -- return 0 on success
        if getifaddrs(&ifaddr) == 0 {
            var interface = ifaddr
            //loop through linked list of interface
            while interface != nil {
                if interface.memory.ifa_addr.memory.sa_family == UInt8(AF_INET) {//ipv4
                    let interfaceName = String.fromCString(interface.memory.ifa_name)
                    let interfaceAddress = String.fromCString(inet_ntoa(UnsafeMutablePointer<sockaddr_in>(interface.memory.ifa_addr).memory.sin_addr))
                    let interfaceNetmask = String.fromCString(inet_ntoa(UnsafeMutablePointer<sockaddr_in>(interface.memory.ifa_netmask).memory.sin_addr))
                    //ifa_dstaddr /* P2P interface destination */
                    //The ifa_dstaddr field references the destination address on a P2P inter-face, interface,
                    //face, if one exists, otherwise it contains the broadcast address.
                    let interfaceBroadcast = String.fromCString(inet_ntoa(UnsafeMutablePointer<sockaddr_in>(interface.memory.ifa_dstaddr).memory.sin_addr))
                    
                    if let name = interfaceName {
                        information[name] = [interfaceAddress!,interfaceNetmask!,interfaceBroadcast!]
                    }
                }
                interface = interface.memory.ifa_next
            }
            freeifaddrs(ifaddr)
        }
        return information
    }
    
    /**
    get WI-FI information
    
    - returns: return Dictionary contain ssid and bssid
    */
    static func getWIFIInformation() -> [String:String] {
        var informationDictionary = [String:String]()
        if #available(iOS 9.0, *) {
            let information = NEHotspotHelper.supportedNetworkInterfaces()
            informationDictionary["SSID"] = information[0].SSID!
            informationDictionary["BSSID"] = information[0].BSSID!
            return informationDictionary
        } else {
            // Fallback on earlier versions
            let informationArray:NSArray? = CNCopySupportedInterfaces()
            if let information = informationArray {
                let dict:NSDictionary? = CNCopyCurrentNetworkInfo(information[0] as! CFStringRef)
                if let temp = dict {
                    informationDictionary["SSID"] = String(temp["SSID"]!)
                    informationDictionary["BSSID"] = String(temp["BSSID"]!)
                    return informationDictionary
                }
            }
        }
        return informationDictionary
    }
}

之后根据IP地址和子网掩码,计算出IP地址池

/// Calculate Network Information about all the possible IP address.....
public class Network{
    
    private var mask:in_addr_t
    private var ip:in_addr_t
    /**
    if ip or netmask is error,return nil
    
    - parameter ipAddress: ip
    - parameter netmask:   mask
    
    - returns: return nil if error
    */
    init?(ipAddress:String, netmask:String){
        ip = inet_addr(ipAddress)
        mask = inet_addr(netmask)
        
        guard ip != INADDR_NONE else { return nil }
        guard mask != INADDR_NONE else { return nil }
    }
    
    /// calculate host number in lan(contain 0 and 255)
    public var HostNumber:Int { return Int(~mask.bigEndian) + 1 }
    
    /// calculate first ip address like 192.168.1.0
    public var firstIPAddress:String { return String.fromCString(inet_ntoa(in_addr(s_addr: ip & mask)))! }
    
    /// calculate all host ip address like 192.168.1.1~192.168.1.254
    public var allHostIP:[String] {
        var temp = [String]()
        for i in 0..<HostNumber - 2 {
            let tempip = CFSwapInt32(CFSwapInt32(inet_addr(firstIPAddress)) + UInt32(i + 1))
            temp.append(String.fromCString(inet_ntoa(in_addr(s_addr: tempip)))!)
        }
        return temp
    }
}

之后循环IP地址,获取到MAC地址就保存对应的条目,并用于之后的显示.

读取缓存表是参考的stackoverflow上面的代码.

//
//  GetMAC.h
//  NetManager
//
//  Created by XWJACK on 3/12/16.
//  Copyright © 2016 XWJACK. All rights reserved.
//

#ifndef GetMAC_h
#define GetMAC_h

#include <stdio.h>
#include <stdlib.h>
//GetMAC
#include <sys/sysctl.h>

#include <netinet/if_ether.h>
#include <net/if_arp.h>
#include <net/route.h>
#include <net/if_dl.h>
#include <sys/socket.h>

#include <err.h>
#include <errno.h>

int ctoMACAddress(in_addr_t addr, char *back);

#endif /* GetMAC_h */

头文件的设置:如果发现找不到对应的头文件,需要将Mac OS中的头文件包含到

如果只是真机调试,就复制到对应的目录.

例如:route.h文件需要从Mac OS对应目录复制到:

/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/usr/include/net/route.h

#include "GetMAC.h"

/**
 *  This function was finded in stackoverflow.
 *  How do I query the ARP table on iPhone?:http://stackoverflow.com/questions/2258172/how-do-i-query-the-arp-table-on-iphone
 *  Getting ARP table on iPhone/iPad:http://stackoverflow.com/questions/10395041/getting-arp-table-on-iphone-ipad
 *  I samplified this code and fixed some memory leak.
 *
 *
 *  @param addr IP Address
 *  @param back MAC Address
 *
 *  @return if error return -1 ,else return 0
 */
int ctoMACAddress(in_addr_t addr, char *back) {
    char *buf,*next;
    size_t needed;
    
    struct rt_msghdr *rtm;
    struct sockaddr_inarp *sin;
    struct sockaddr_dl *sdl;
    
    int mib[6] = {
        CTL_NET,//Top-level identifiers  network
        PF_ROUTE,//Protocol families, same as address families for now.
        0,
        AF_INET,//internetwork: UDP, TCP
        NET_RT_FLAGS,//PF_ROUTE - Routing table
        RTF_LLINFO//generated by link layer
    };
    
    if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) {
        printf("route-sysctl-estimate");
        return -1;
    }
    if ((buf = (char *)malloc(needed)) == NULL) {
        printf("malloc");
        return -1;
    }
    if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) {
        printf("retrieval of routing table");
        free(buf);
        return -1;
    }
    
    for (next = buf; next < buf + needed; next += rtm->rtm_msglen) {
        
        rtm = (struct rt_msghdr *)next;
        sin = (struct sockaddr_inarp *)(rtm + 1);
        sdl = (struct sockaddr_dl *)(sin + 1);
        
        if (addr != sin->sin_addr.s_addr || sdl->sdl_alen < 6) { continue; }
        
        u_char *cp = (u_char*)LLADDR(sdl);
        
        //ret = [NSString stringWithFormat:@"%02X:%02X:%02X:%02X:%02X:%02X",cp[0], cp[1], cp[2], cp[3], cp[4], cp[5]];
        sprintf(back, "%02X:%02X:%02X:%02X:%02X:%02X", cp[0], cp[1], cp[2], cp[3], cp[4], cp[5]);
        break;
    }
    if (next >= buf + needed) {
        free(buf);
        return -1;
    }
    
    free(buf);
    return 0;
}

至于MAC地址和主机名的获取是扩展String方法实现的,这样很简单:

// MARK: - It's very convenience to change IP to MACAddress or HostName
extension String {
    public var toMACAddress:String? {
        let back:UnsafeMutablePointer = UnsafeMutablePointer<Int8>((self as NSString).UTF8String)
        if ctoMACAddress(inet_addr(self), back) == -1 { return nil }
        return String.fromCString(back)
    }
    public var toHostName:String? {
        let back:UnsafeMutablePointer = UnsafeMutablePointer<Int8>((self as NSString).UTF8String)
        var ip = in_addr()
        guard inet_aton(back, &ip) == 1 else { return nil }
        let hp = gethostbyaddr(&ip, UInt32(sizeofValue(ip)), AF_INET)
        if hp != nil { return String.fromCString(hp.memory.h_name) }
        return nil
    }
}

具体的扫描类:进程和线程的概念还是没有熟悉....还需要多看.那个败笔等我学会了就会更新.

/// Globe varible to store all interface information: ip,mac,name,picture sort by ip.
var list = [String:[String]]()

public class Scanner {
    public static func refresh() {
        
        /// get local interface ip,netmask,broadcast
        let allInterfaceInformation = GetInterfaceInformation.getInterfaceInformation()
        
        if allInterfaceInformation["en0"] == nil {
            let alert = UIAlertView(title: "No Network", message: "You have not connected to Wi-Fi", delegate: nil, cancelButtonTitle: "OK")
            alert.show()
            return
        }
        let wifi = GetInterfaceInformation.getWIFIInformation()
        
        /// Calculate all ip address
        if let network = Network(ipAddress: allInterfaceInformation["en0"]![0], netmask: allInterfaceInformation["en0"]![1]) {
            let allhostip = network.allHostIP
            
            //let group = dispatch_group_create()
            dispatch_sync(dispatch_queue_create(nil, DISPATCH_QUEUE_SERIAL), {
                for i in allhostip {
                    dispatch_async(dispatch_queue_create(nil, DISPATCH_QUEUE_CONCURRENT),  {
                        let ping = xSocketPing(ipAddress: i, packetNumber: 1, timeout: 10, delegate: nil)
                        ping.xPing()
                    })
                }
            //dispatch_group_notify(group, dispatch_queue_create(nil, DISPATCH_QUEUE_SERIAL), {
                NSThread.sleepForTimeInterval(5)//这是个败笔
                
                for i in allhostip {
                    //if ip is myslef, jump.
                    if i == allInterfaceInformation["en0"]![0] { list[i] = ["xx:xx:xx:xx:xx:xx", UIDevice.currentDevice().name, "Local.png"]; continue }
                    
                    if let MACAddress = i.toMACAddress {
                        //if mac is route
                        
                        if wifi["BSSID"]! == MACAddress {
                            list[i] = [MACAddress, wifi["SSID"]!, "Wifi.png"]
                            continue
                        }
                        //others
                        if let hostname = i.toHostName { list[i] = [MACAddress, hostname, "User.png"]; continue }
                        list[i] = [MACAddress, "unknow", "User.png"]
                    }
                    //print(list)
                }
            })
            //print(allhostip)
        }else {
            let alert = UIAlertView(title: "Error", message: "Calculate Error", delegate: nil, cancelButtonTitle: "OK")
            alert.show()
            return
        }
        print(list)
    }
}

运行环境OS X10.10.5,Xcode7.0,Swift2.1,iOS9.0模拟器

如果任然有疑惑可以评论.新浪博客已经不更新了..但是博客园还是会继续更新下去.
如果发现任何错误也可以联系我,谢谢

GitHub项目地址:NetManager

本程序还有很多不足之处,后续会持续更新,并更新GitHub项目,需要改进的,请在博客上留言
抓包的图片是不更新的,所以会和运行结果图不一样.

更新于2016-3-13
新增主机发现功能,mac地址解析功能,本机mac不能使用,用xx:xx:xx:xx:xx:xx代替,获得WiFi的SSID和BSSID.
程序依旧有许多不足的地方,如果有大神,希望帮我改改.
- 没有运行循环,用的是超时.
- 有时候会出现连续发送icmp失败的情况.
- 再次刷新的时候会出现bogon变成unknow的情况.
- 主机发现是根据stackoverflow上面的代码改编的.应该是读取arp缓存表,但是前提是发送icmp来刷新缓存表.
- 发送icmp数据包是多线程异步并列的形式发送.线程这里没有处理好,当学会了之后再更新.
- 那个进度条还没有添加,给人感觉是卡死的,因为设置的是同步的.

更新于2016-1-13
修复bug,优化部分显示,更好,更安全的处理指针类型.

更新于2016-1-12
新增功能:优化显示,将返回的结果显示到模拟器中.发送数据包在额外的线程中进行,不会阻塞主线程.由于程序使用的是Swift和C语言混合编程,用到了指针,交互的时候容易crash.后续会继续修复bug.

更新2016-1-7
新增功能:优化显示,将返回结果集中到主函数中,方便调用,修复部分bug,添加超时处理,防止程序一直处于阻塞状态.