ffi.py

from cffi import FFI

ffi = FFI()
ffi.cdef("""
void *malloc(size_t size);

#define CLONE_NEWNS 0x00020000
#define CLONE_NEWCGROUP 0x02000000
#define CLONE_NEWUTS 0x04000000
#define CLONE_NEWIPC 0x08000000
#define CLONE_NEWNET 0x40000000
#define CLONE_NEWUSER 0x10000000
#define CLONE_NEWPID 0x20000000
#define CLONE_NEWTIME 0x00000080

int clone(int (*fn)(void *), void *stack, int flags, void *arg, ...);

typedef struct {
    unsigned char r, g, b;
} pixel_t;
""")
C = ffi.dlopen(None)


print('CLONE_NEWNS', C.CLONE_NEWNS)


@ffi.callback("int(void *)")
def child(arg):
    pixel = ffi.cast("pixel_t *", arg)
    print("child arg", pixel.r, pixel.g, pixel.b)
    return 0

stack = C.malloc(1024*1024)
print('malloc(1024*1024)', stack)

arg = ffi.new("pixel_t*")
arg.r = 0
arg.g = 0
arg.b = 0

ret = C.clone(child, stack+1024*1024, C.CLONE_NEWNS, ffi.cast("void *", arg))
print('clone(child)', ret)