ipf_hook
return ipf_hook(info, 1, 0, arg);
return ipf_hook(info, 0, 0, arg);
return ipf_hook(info, 1, FI_NOCKSUM, arg);
ipf_hook(info, out, 0, arg));
return ipf_hook(info, 0, FI_NOCKSUM, arg);
static int ipf_hook __P((hook_data_t, int, int, void *));