-void cap_init(const char *device, const char *filter, int promisc);
+void cap_add_ifname(const char *ifname); /* call one or more times */
+void cap_add_filter(const char *filter); /* call zero or more times */
+void cap_start(const int promisc);
void cap_fd_set(fd_set *read_set, int *max_fd,
struct timeval *timeout, int *need_timeout);
void cap_poll(fd_set *read_set);
void cap_stop(void);
void cap_fd_set(fd_set *read_set, int *max_fd,
struct timeval *timeout, int *need_timeout);
void cap_poll(fd_set *read_set);
void cap_stop(void);