C ++ DGRAM套接字获取RECEIVER地址 [英] C++ DGRAM socket get the RECEIVER address

问题描述

在C ++中，

如何获取使用recvfrom接收的UDP数据包的接收方地址。我知道它应该是相同的主机，我收到的数据包，但我需要从接收的数据包中提取，以验证一些东西。我如何做到这一点？

我发现一种方法是：

 code> int r = getsockopt（receiver_sock，SOL_IP，SO_ORIGINAL_DST，（struct sockaddr *）& sender_addr，（socklen_t *）& addr_len）;`
  

但我遇到错误：

 错误：SO_ORIGINAL_DST未在此范围中声明
  

我使用适当的标题

  #include< sys / types.h> 
 #include< sys / socket.h> 
 #include< netinet / in.h> 
 #include< /usr/src/linux-headers-2.6.32-21/include/linux/netfilter_ipv4.h> 
 #include< arpa / inet.h> 
 #include< linux / netfilter.h> 
  

使用netfilter_ipv4给出其他错误，如INT_MIN未声明。但是，我认为错误是更根本的，而不是包含正确的标题。

请帮助。

解决方案

在Linux上，您要使用 IP_PKTINFO 选项，请参阅 ip（7） ， http://www.kernel.org/doc/man-pages/online/pages/man2/sendmsg.2.html =nofollow> recvmsg（2） 呼叫。

Stevens 有这样做的例子，但使用在Linux上不可用的 IP_RECVDSTADDR 和 IP_RECVIF 选项。 / p>

In C++,
how can I get the receiver address of the UDP packet which I have received using recvfrom. I know that it should be the same host on which I am receiving the packet, but I need to extract it from the received packet, in order to verify something. How can I do this?

I found that one way of doing this is:

int r = getsockopt(receiver_sock, SOL_IP, SO_ORIGINAL_DST, (struct sockaddr *) &sender_addr, (socklen_t *)&addr_len);`

But I get the error:

error: ‘SO_ORIGINAL_DST’ was not declared in this scope

I am using the appropriate headers

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include </usr/src/linux-headers-2.6.32-21/include/linux/netfilter_ipv4.h>
#include <arpa/inet.h>    
#include <linux/netfilter.h>

Using netfilter_ipv4 gives other errors like INT_MIN not declared. However, I think the mistake is something more fundamental rather than inclusion of proper header.

Please help.

解决方案

On Linux you want to use IP_PKTINFO option, see ip(7), and the recvmsg(2) call.

Stevens has examples of doing this but with IP_RECVDSTADDR and IP_RECVIF options that are not available on Linux.

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