7

我试图以这种方式获取路由器地址。

- (NSString *) routerIp {

  NSString *address = @"error";
  struct ifaddrs *interfaces = NULL;
  struct ifaddrs *temp_addr = NULL;
  int success = 0;

  // retrieve the current interfaces - returns 0 on success
  success = getifaddrs(&interfaces);
  if (success == 0)
  {
    // Loop through linked list of interfaces
    temp_addr = interfaces;
    while(temp_addr != NULL)
    {
      if(temp_addr->ifa_addr->sa_family == AF_INET)
      {
        // Check if interface is en0 which is the wifi connection on the iPhone
        if([[NSString stringWithUTF8String:temp_addr->ifa_name] isEqualToString:@"en0"])
        {
          // Get NSString from C String //ifa_addr
          address = [NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_dstaddr)->sin_addr)];
        }
      }

      temp_addr = temp_addr->ifa_next;
    }
  }

  // Free memory
  freeifaddrs(interfaces);

  return address;
}

路由器地址总是看起来像 xxx.xxx.255.255 但它应该看起来像 xxx.xxx.0.1 或类似的东西......

有什么办法可以获取有效地址吗?

谢谢你的帮助!

4

3 回答 3

10

我一直在寻找一种方法来自己获取默认网关的 IP 地址。我将只关注这一点 - 我不需要获取默认路由器的 MAC 地址,所以这只是部分回答了 OP 的问题。

我不喜欢解析 netstat 输出的想法。此外,您无法根据机器上接口的 IP 地址获得默认路由。与您相同范围内的任何 IP 地址都可以作为默认网关 - 唯一的规则是您的 IP 和默认网关都需要属于同一子网。

我要确保的另一件事是获取默认网关的 IP 地址,即使我的多个本地接口都分配有 IP 地址(例如,我同时连接到 Wifi 和有线以太网时间,并且两个接口都已启动,并带有 IP 地址)。对于我的应用程序,通过哪个接口设置默认路由并不重要(它可以是 en0、en1、ppp0 或其他任何东西)。

我认为获取该信息的最佳(也是最类似于 Apple)的方法是使用系统配置框架 - 此线程中上述帖子中的链接为我指明了这个方向,但并没有真正提供有关如何进行的详细信息使用它,我没有发现它的 Apple 文档很有用(至少考虑到我的技能水平)。

请注意,我在 Objective-C 方面不是很有经验 - 我正在编写一个我自己需要的应用程序(而且我找不到),对于那个应用程序,我只需要默认的 IP 地址网关。

所以 - 这就是我在我的应用程序中所做的,它似乎工作正常(而且比我迄今为止发现的大多数其他解决方案更短更简单:

- (NSString *)defaultRouter {

    SCDynamicStoreRef ds = SCDynamicStoreCreate(kCFAllocatorDefault, CFSTR("myapp"), NULL, NULL);
    CFDictionaryRef dr = SCDynamicStoreCopyValue(ds, CFSTR("State:/Network/Global/IPv4"));
    CFStringRef router = CFDictionaryGetValue(dr, CFSTR("Router"));
    NSString *routerString = [NSString stringWithString:(__bridge NSString *)router];
    CFRelease(dr);
    CFRelease(ds);

    return routerString;
}

请注意,在我的应用程序中,上面是一个更大的方法的一部分(我实际上没有 defaultRouter: 方法)。此外,为简洁起见,我省略了一些检查(如 [routerString 长度] 等)。

希望有人觉得这很有用。也请随时修复我在上面的代码中可能遇到的任何错误——我还是个新手!

PS。当我检查使用系统配置框架本身的“scutil”的输出时,我知道要寻找什么:

MacBook:~$ scutil 
> show State:/Network/Global/IPv4
<dictionary> {
  PrimaryInterface : en1
  PrimaryService : <service_id>
  Router : <ipv4_address>
}
> show State:/Network/Global/IPv6
<dictionary> {
  PrimaryInterface : en1
  PrimaryService : <service_id>
  Router : <ipv6_address>
}
于 2012-12-03T21:14:37.677 回答
4

这是我为查找机器路径而编写的一些代码。我从netstat. 请注意,强烈建议我不要这样做,因为这些系统调用不是受支持的 API,并且可能随时更改。他们建议我只解析netstat.

自定义路由.c:

#import "CustomRoute.h"
@implementation CustomRoute

+ (NSMutableArray*) getRoutes
{
    NSMutableArray* routeArray = [NSMutableArray array];
    CustomRoute* route = nil;

    size_t needed;
    int mib[6];
    char *buf, *next, *lim;
    register struct rt_msghdr2 *rtm;

    mib[0] = CTL_NET;
    mib[1] = PF_ROUTE;
    mib[2] = 0;
    mib[3] = 0;
    mib[4] = NET_RT_DUMP2;
    mib[5] = 0;

    if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) {
        err(1, "sysctl: net.route.0.0.dump estimate");
    }

    if ((buf = malloc(needed)) == 0) {
        err(2, "malloc(%lu)", (unsigned long)needed);
    }
    if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) {
        err(1, "sysctl: net.route.0.0.dump");
    }

    lim  = buf + needed;

    for (next = buf; next < lim; next += rtm->rtm_msglen) {
        rtm = (struct rt_msghdr2 *)next;
        route = [self getRoute:rtm];
        if(route != nil)
        {
            [routeArray addObject:route];
        }
    }
    free(buf);
    printf("Total routes: %u\n",    [routeArray count]);
    return routeArray;
}


+ (CustomRoute*) getRoute:(struct rt_msghdr2 *)rtm
{
    //sockaddrs are after the message header
    struct sockaddr* dst_sa = (struct sockaddr *)(rtm + 1);

    CustomRoute* route = nil;

    if(rtm->rtm_addrs & RTA_DST)
    {
        switch(dst_sa->sa_family)
        {
            case AF_INET:
                if(dst_sa->sa_family == AF_INET && !((rtm->rtm_flags & RTF_WASCLONED) && (rtm->rtm_parentflags & RTF_PRCLONING)))
                {
                    route = [[CustomRoute alloc] initWithRtm:rtm];
                }
            break;

        }
    }

    return route;
}

-(void) setAddr:(struct sockaddr*)sa index:(int)rtax_index
{
    if(rtax_index >= 0 && rtax_index < RTAX_MAX)
    {
        memcpy(&(m_addrs[rtax_index]), sa, sizeof(struct sockaddr));
    }

}

-(NSString*) getDestination
{
    return [self getAddrStringByIndex:RTAX_DST];
}

-(NSString*) getNetmask
{
    return [self getAddrStringByIndex:RTAX_NETMASK];
}

-(NSString*) getGateway
{
    return [self getAddrStringByIndex:RTAX_GATEWAY];
}

-(NSString*) getDetails
{
    NSMutableString* result = [[NSMutableString alloc] init];
    [result appendFormat: [NSString stringWithFormat: @"message type: 0x%06x\n", m_rtm.rtm_type]];
    [result appendFormat: [NSString stringWithFormat: @"flags: 0x%06x\n", m_rtm.rtm_flags]];
    [result appendFormat: [NSString stringWithFormat: @"addrs: 0x%06x\n", m_rtm.rtm_addrs]];


    return result;
}


-initWithRtm: (struct rt_msghdr2*) rtm
{
    int i;
    struct sockaddr* sa = (struct sockaddr*)(rtm + 1);


    //copy over the route message
    memcpy(&(m_rtm), rtm, sizeof(struct rt_msghdr2));
    for(i = 0; i < RTAX_MAX; i++)
    {
        [self setAddr:&(sa[i]) index:i];
    }
    return self;
}

- init
{
    memset(m_addrs, 0, sizeof(m_addrs));
    return self;
}

@end


@implementation CustomRoute (Private)

-(NSString*) getAddrStringByIndex: (int)rtax_index
{
    NSString * routeString = nil;
    struct sockaddr* sa = &(m_addrs[rtax_index]);
    int flagVal = 1 << rtax_index;

    if(!(m_rtm.rtm_addrs & flagVal))
    {
        return @"none";
    }


    if(rtax_index >= 0 && rtax_index < RTAX_MAX)
    {
        switch(sa->sa_family)
        {
            case AF_INET:
            {
                struct sockaddr_in* si = (struct sockaddr_in *)sa;
                if(si->sin_addr.s_addr == INADDR_ANY)
                    routeString = @"default";
                else
                    routeString = [NSString stringWithCString:(char *)inet_ntoa(si->sin_addr) encoding:NSASCIIStringEncoding];
            }
            break;

            case AF_LINK:
                {
                    struct sockaddr_dl* sdl = (struct sockaddr_dl*)sa;
                    if(sdl->sdl_nlen + sdl->sdl_alen + sdl->sdl_slen == 0)
                    {
                        routeString = [NSString stringWithFormat: @"link #%d", sdl->sdl_index];
                    }
                    else
                        routeString = [NSString stringWithCString:link_ntoa(sdl) encoding:NSASCIIStringEncoding];
                }
            break;

            default:
                {
                    char a[3 * sa->sa_len];
                    char *cp;
                    char *sep = "";
                    int i;

                    if(sa->sa_len == 0)
                    {
                        routeString = @"empty";
                    }
                    else
                    {
                        a[0] = (char)NULL;
                        for(i = 0, cp = a; i < sa->sa_len; i++)
                        {
                            cp += sprintf(cp, "%s%02x", sep, (unsigned char)sa->sa_data[i]);
                            sep = ":";
                        }
                        routeString = [NSString stringWithCString:a encoding:NSASCIIStringEncoding];
                    }
                }
        }
    }
    return routeString;
}

@end

自定义路由.h:

#import <Cocoa/Cocoa.h>
#import <net/route.h>
#import <sys/socket.h>
#import <netinet/in.h>
#import <net/if_dl.h>
#import <sys/sysctl.h>

@interface CustomRoute : NSObject {
    struct sockaddr     m_addrs[RTAX_MAX];
    struct rt_msghdr2   m_rtm;
    int                 m_len;      /* length of the sockaddr array */
}

+ (NSMutableArray*) getRoutes;
+ (CustomRoute*) getRoute:(struct rt_msghdr2 *)rtm;

- (void) setAddr:(struct sockaddr*)sa index:(int)rtax_index;

- (NSString*) getDestination;
- (NSString*) getNetmask;
- (NSString*) getGateway;
- initWithRtm: (struct rt_msghdr2*) rtm;


@end
于 2010-01-23T21:45:31.400 回答
1

xxx.xxx.255.255 is the subnet mask. You need the gateway address.

See table 3-10, there is an entry for router in thsi pdf: http://developer.apple.com/Mac/library/documentation/Networking/Conceptual/SystemConfigFrameworks/SystemConfigFrameworks.pdf

The HTML version is here: http://developer.apple.com/Mac/library/documentation/Networking/Conceptual/SystemConfigFrameworks/SC_Overview/SC_Overview.html

于 2010-01-21T23:00:47.030 回答