pcap_list_tstamp_types, pcap_free_tstamp_types - get a list of time stamp types
  supported by a capture device, and free that list
#include <pcap/pcap.h>
int pcap_list_tstamp_types(pcap_t *p, int **tstamp_typesp);
void pcap_free_tstamp_types(int *tstamp_types);
pcap_list_tstamp_types() is used to get a list of the supported time
  stamp types of the interface associated with the pcap descriptor.
  pcap_list_tstamp_types() allocates an array to hold the list and sets
  *tstamp_typesp to point to the array. See pcap-tstamp(7) for a
  list of all the time stamp types.
The caller is responsible for freeing the array with
    pcap_free_tstamp_types(), which frees the list pointed to by
    tstamp_types.
pcap_list_tstamp_types() returns the number of time stamp types in the
  array on success and PCAP_ERROR on failure. A return value of one means
  that the only time stamp type supported is the one in the list, which is the
  capture device's default time stamp type. A return value of zero means that
  the only time stamp type supported is PCAP_TSTAMP_HOST, which is the
  capture device's default time stamp type (only older versions of libpcap will
  return that; newer versions will always return one or more types). If
  PCAP_ERROR is returned, pcap_geterr(3) or pcap_perror(3)
  may be called with p as an argument to fetch or display the error text.
These functions became available in libpcap release 1.2.1. In previous releases,
  the time stamp type cannot be set; only the default time stamp type offered by
  a capture source is available.
pcap(3), pcap_tstamp_type_val_to_name(3), pcap-tstamp(7)