如何获取ios设备的当前IP地址

#define MAXADDRS    32

extern char *if_names[MAXADDRS];
extern char *ip_names[MAXADDRS];
extern char *hw_addrs[MAXADDRS];
extern unsigned long ip_addrs[MAXADDRS];

// Function prototypes

void InitAddresses();
void FreeAddresses();
void GetIPAddresses();
void GetHWAddresses();
IPAddress.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <sys/sockio.h>
#include <net/if.h>
#include <errno.h>
#include <net/if_dl.h>
#include <net/ethernet.h>
#include "IPAddress.h"

#define min(a,b)    ((a) < (b) ? (a) : (b))
#define max(a,b)    ((a) > (b) ? (a) : (b))

#define BUFFERSIZE  4000

char *if_names[MAXADDRS];
char *ip_names[MAXADDRS];
char *hw_addrs[MAXADDRS];
unsigned long ip_addrs[MAXADDRS];

static int   nextAddr = 0;

void InitAddresses()
{
    int i;
    for (i=0; i<MAXADDRS; ++i)
    {
        if_names[i] = ip_names[i] = hw_addrs[i] = NULL;
        ip_addrs[i] = 0;
    }
}

void FreeAddresses()
{
    int i;
    for (i=0; i<MAXADDRS; ++i)
    {
        if (if_names[i] != 0) free(if_names[i]);
        if (ip_names[i] != 0) free(ip_names[i]);
        if (hw_addrs[i] != 0) free(hw_addrs[i]);
        ip_addrs[i] = 0;
    }
    InitAddresses();
}

void GetIPAddresses()
{
    int                 i, len, flags;
    char                buffer[BUFFERSIZE], *ptr, lastname[IFNAMSIZ], *cptr;
    struct ifconf       ifc;
    struct ifreq        *ifr, ifrcopy;
    struct sockaddr_in  *sin;

    char temp[80];

    int sockfd;

    for (i=0; i<MAXADDRS; ++i)
    {
        if_names[i] = ip_names[i] = NULL;
        ip_addrs[i] = 0;
    }

    sockfd = socket(AF_INET, SOCK_DGRAM, 0);
    if (sockfd < 0)
    {
        perror("socket failed");
               return;
               }

   ifc.ifc_len = BUFFERSIZE;
   ifc.ifc_buf = buffer;

   if (ioctl(sockfd, SIOCGIFCONF, &ifc) < 0)
   {
       perror("ioctl error");
              return;
              }

      lastname[0] = 0;

      for (ptr = buffer; ptr < buffer + ifc.ifc_len; )
      {
          ifr = (struct ifreq *)ptr;
          len = max(sizeof(struct sockaddr), ifr->ifr_addr.sa_len);
          ptr += sizeof(ifr->ifr_name) + len;   // for next one in buffer

          if (ifr->ifr_addr.sa_family != AF_INET)
          {
              continue; // ignore if not desired address family
          }

          if ((cptr = (char *)strchr(ifr->ifr_name, ':')) != NULL)
          {
              *cptr = 0;        // replace colon will null
          }

          if (strncmp(lastname, ifr->ifr_name, IFNAMSIZ) == 0)
          {
              continue; /* already processed this interface */
          }

          memcpy(lastname, ifr->ifr_name, IFNAMSIZ);

          ifrcopy = *ifr;
          ioctl(sockfd, SIOCGIFFLAGS, &ifrcopy);
          flags = ifrcopy.ifr_flags;
          if ((flags & IFF_UP) == 0)
          {
              continue; // ignore if interface not up
          }

          if_names[nextAddr] = (char *)malloc(strlen(ifr->ifr_name)+1);
          if (if_names[nextAddr] == NULL)
          {
              return;
          }
          strcpy(if_names[nextAddr], ifr->ifr_name);

          sin = (struct sockaddr_in *)&ifr->ifr_addr;
          strcpy(temp, inet_ntoa(sin->sin_addr));

          ip_names[nextAddr] = (char *)malloc(strlen(temp)+1);
          if (ip_names[nextAddr] == NULL)
          {
              return;
          }
          strcpy(ip_names[nextAddr], temp);

          ip_addrs[nextAddr] = sin->sin_addr.s_addr;

          ++nextAddr;
      }

    close(sockfd);
}

void GetHWAddresses()
{
    struct ifconf ifc;
    struct ifreq *ifr;
    int i, sockfd;
    char buffer[BUFFERSIZE], *cp, *cplim;
    char temp[80];

    for (i=0; i<MAXADDRS; ++i)
    {
        hw_addrs[i] = NULL;
    }

    sockfd = socket(AF_INET, SOCK_DGRAM, 0);
    if (sockfd < 0)
    {
        perror("socket failed");
        return;
    }

    ifc.ifc_len = BUFFERSIZE;
    ifc.ifc_buf = buffer;

    if (ioctl(sockfd, SIOCGIFCONF, (char *)&ifc) < 0)
    {
        perror("ioctl error");
        close(sockfd);
        return;
     }

     ifr = ifc.ifc_req;

     cplim = buffer + ifc.ifc_len;

     for (cp=buffer; cp < cplim; )
     {
         ifr = (struct ifreq *)cp;
         if (ifr->ifr_addr.sa_family == AF_LINK)
         {
             struct sockaddr_dl *sdl = (struct sockaddr_dl *)&ifr->ifr_addr;
             int a,b,c,d,e,f;
             int i;

             strcpy(temp, (char *)ether_ntoa((const struct ether_addr *)LLADDR(sdl)));
             sscanf(temp, "%x:%x:%x:%x:%x:%x", &a, &b, &c, &d, &e, &f);
            sprintf(temp, "%02X:%02X:%02X:%02X:%02X:%02X",a,b,c,d,e,f);

            for (i=0; i<MAXADDRS; ++i)
            {
                if ((if_names[i] != NULL) && (strcmp(ifr->ifr_name, if_names[i]) == 0))
                {
                    if (hw_addrs[i] == NULL)
                    {
                        hw_addrs[i] = (char *)malloc(strlen(temp)+1);
                        strcpy(hw_addrs[i], temp);
                        break;
                    }
                }
            }
        }
         cp += sizeof(ifr->ifr_name) + max(sizeof(ifr->ifr_addr), ifr->ifr_addr.sa_len);
    }
    close(sockfd);
}
使用的方法

- (void)getIPAddress
{
    InitAddresses();
    GetIPAddresses();
    GetHWAddresses();

    int i;
    NSString *deviceIP = nil;
    for (i=0; i<MAXADDRS; ++i)
    {
        static unsigned long localHost = 0x7F000001;            // 127.0.0.1
        unsigned long theAddr;

        theAddr = ip_addrs[i];

        if (theAddr == 0) break;
        if (theAddr == localHost) continue;

        NSLog(@"Name: %s MAC: %s IP: %s\n", if_names[i], hw_addrs[i], ip_names[i]);
    }
}
[self getIPAddress]就能获取当前IP地址。

2013年6月11日添加 今天我项目添加一个功能，实时检测设备IP地址，发现上述代码FreeAddress也无用。 在http://stackoverflow.com/questions/7072989/iphone-ipad-how-to-get-my-ip-address-programmatically有更为简单的获取IP地址的方法，并且能实时更新。