strace of it working

file_678044.txt (text/plain), 502 bytes, created by Matthew Thode ( prometheanfire ) on 2019-02-17 02:53:05 UTC

openat(AT_FDCWD, "/proc/net/ip_tables_names", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0440, st_size=0, ...}) = 0
read(3, "nat\nfilter\n", 1024)          = 11
socket(AF_INET, SOCK_RAW, IPPROTO_RAW)  = 4
fcntl(4, F_SETFD, FD_CLOEXEC)           = 0
getsockopt(4, SOL_IP, IPT_SO_GET_INFO, "nat\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., [84]) = 0
getsockopt(4, SOL_IP, IPT_SO_GET_ENTRIES, "nat\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., [1160]) = 0