如何在C/C++中接收原始的第2层数据包？

在POSIXy C中如何接收第二层数据包？数据包只有src和dst MAC地址,类型/长度和自定义格式的数据.他们不是TCP或UDP或IP或IGMP或ARP或其他 – 他们是由五金家伙给我的家庭酿造的格式.

我的套接字(AF_PACKET,SOCK_RAW,IPPROTO_RAW)不会从其recvfrom()返回.

我可以发送正常,我无法接收,无论我在网络堆栈中的什么选项.

(平台是VxWorks,但我可以翻译POSIX或Linux或其他任何…)

接收代码(当前化身)：

int s;

 if ((s = socket(AF_PACKET,IPPROTO_RAW)) < 0) {
  printf("socket create error.");
      return -1;
 }

   struct ifreq          _ifr;   
   strncpy(_ifr.ifr_name,"lltemac0",strlen("lltemac0"));
   ioctl(s,IP_SIOCGIFINDEX,&_ifr);

   struct sockaddr_ll _sockAttrib;
   memset(&_sockAttrib,sizeof(_sockAttrib));
   _sockAttrib.sll_len      = sizeof(_sockAttrib);
   _sockAttrib.sll_family   = AF_PACKET;
   _sockAttrib.sll_protocol = IFT_ETHER;
   _sockAttrib.sll_ifindex  = _ifr.ifr_ifindex;
   _sockAttrib.sll_hatype   = 0xFFFF;
   _sockAttrib.sll_pkttype  = PACKET_HOST;
   _sockAttrib.sll_halen    = 6;
   _sockAttrib.sll_addr[0]  = 0x00;
   _sockAttrib.sll_addr[1]  = 0x02;
   _sockAttrib.sll_addr[2]  = 0x03;
   _sockAttrib.sll_addr[3]  = 0x12;
   _sockAttrib.sll_addr[4]  = 0x34;
   _sockAttrib.sll_addr[5]  = 0x56;
   int _sockAttribLen = sizeof(_sockAttrib);


 char packet[64];
 memset(packet,sizeof(packet));

   if (recvfrom(s,(char *)packet,sizeof(packet),(struct sockaddr *)&_sockAttrib,&_sockAttribLen) < 0)
   {
      printf("packet receive error.");
   }

   // code never reaches here