field ‘ifru_addr’ has incomplete type ‘sockaddr’

I am doing the Standford CS144 lab, but the code cannot make

In file included from /home/wangyan/csLab/sponge/libsponge/util/tun.cc:7:
/usr/include/linux/if.h:211:19: error: field ‘ifru_addr’ has incomplete type ‘sockaddr’ 
struct sockaddr ifru_addr;

I try the others recommend，add the code

#include <sys/socket.h>

It still doesn't work