获取网络包到达网卡的时间

#include <sys/socket.h> 
#include <netinet/in.h> 
#include <arpa/inet.h> 
#include <unistd.h> 
#include <stdlib.h> 
#include <string.h> 
#include <stdio.h> 
#include <stdint.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#define PORT 31500

int main(){ 
     int sockfd,len; 
     struct sockaddr_in addr; 
     int addr_len = sizeof(struct sockaddr_in); 
     char buffer[256]; 

     if((sockfd=socket(AF_INET,SOCK_DGRAM,0))<0){ 
          perror ("socket"); 
          exit(1); 
     } 

     bzero ( &addr, sizeof(addr) ); 
     addr.sin_family=AF_INET; 
     addr.sin_port=htons(PORT); 
     addr.sin_addr.s_addr=htonl(INADDR_ANY) ; 
     if (bind(sockfd, (struct sockaddr *)&addr, sizeof(addr))<0){ 
          perror("connect"); 
          exit(1); 
     } 
     struct timeval tv, tvNow,tvRes;
     while(1){ 
          bzero(buffer,sizeof(buffer)); 
          len = recvfrom(sockfd,buffer,sizeof(buffer), 0 , (struct sockaddr *)&addr ,(socklen_t*)&addr_len); 
          printf("receive from %s\n" , inet_ntoa( addr.sin_addr)); 
          int iRet = ioctl(sockfd, SIOCGSTAMP, &tv);
          gettimeofday(&tvNow, NULL);
          uint64_t ddwNow = tvNow.tv_sec*1000000 + tvNow.tv_usec;
          uint64_t ddwTv = tv.tv_sec*1000000 + tv.tv_usec;

          printf("Now:%lu Tv:%lu dff:%lu\n",ddwNow,ddwTv,(ddwNow - ddwTv)/1000000);
          sleep(10);
     } 
     return 0;
}  

import socket
address = (‘127.0.0.1‘,31500)
s = socket.socket(socket.AF_INET,socket.SOCK_DGRAM)
while True:
     msg = raw_input()
     if not msg:
          break
     s.sendto(msg,address)

s.close()

#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <stdint.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#define SERVPORT 31500

int main(int argc, char **argv) 
{ 
     int sockfd; 
     struct sockaddr_in srvAddr; 
     sockfd = socket(AF_INET ,SOCK_DGRAM,0 ); 
     if(sockfd< 0 ) 
     { 
          printf("socket error\n"); 
          return 0; 
     }    

     bzero(&srvAddr, sizeof(srvAddr) ); 
     srvAddr.sin_family = AF_INET; 
     srvAddr.sin_port   = htons(SERVPORT); 
     srvAddr.sin_addr.s_addr = htonl(INADDR_ANY); 

     bind(sockfd, (struct sockaddr*)&srvAddr,sizeof(srvAddr)); 

     while(1) 
     {    
          struct msghdr msg; 

          struct sockaddr_in clientAddr; 
          msg.msg_name = &clientAddr; 
          msg.msg_namelen= sizeof(clientAddr); 

          struct iovec iov; 
          msg.msg_iov = &iov; 
          msg.msg_iovlen =1; 
          char text[1024] ; 
          iov.iov_base= text; 
          iov.iov_len = sizeof(text); 

          char ctrl[CMSG_SPACE(sizeof(struct timeval))]; 
          struct cmsghdr *cmsg=(struct cmsghdr*)&ctrl; 
          msg.msg_control = (caddr_t)ctrl; 
          msg.msg_controllen = sizeof(ctrl); 

          int rc = recvmsg(sockfd,&msg,0); 
          if(rc== -1) 
          { 
               printf("recvmsg error\n"); 
               return 0; 
          } 

          struct timeval tv, tvNow,tvRes;

          if(cmsg->cmsg_level ==SOL_SOCKET&& 
                    cmsg->cmsg_type  ==SCM_TIMESTAMP && 
                    cmsg->cmsg_len   ==CMSG_LEN(sizeof(tv)) 
            ) 
          memcpy(&tv,CMSG_DATA(cmsg),sizeof(tv)); 
          gettimeofday(&tvNow, NULL);
          uint64_t ddwNow = tvNow.tv_sec*1000000 + tvNow.tv_usec;
          uint64_t ddwTv = tv.tv_sec*1000000 + tv.tv_usec;

          printf("Now:%lu Tv:%lu dff:%lu\n",ddwNow,ddwTv,(ddwNow - ddwTv)/1000000);
          sleep(10);
     } 
}