#include <pcap/pcap.h> int pcap_set_tstamp_type(pcap_t *p, int tstamp_type);
pcap_set_tstamp_type() sets the type of time stamp desired for packets captured on the pcap descriptor to the type specified by tstamp_type. It must be called on a pcap descriptor created by pcap_create(3PCAP) that has not yet been activated by pcap_activate(3PCAP). pcap_list_tstamp_types(3PCAP) will give a list of the time stamp types supported by a given capture device. See pcap-tstamp(7) for a list of all the time stamp types.
pcap_set_tstamp_type() returns 0 on success if the specified time stamp type is expected to be supported by the capture device, PCAP_WARNING_TSTAMP_TYPE_NOTSUP if the specified time stamp type is not supported by the capture device, PCAP_ERROR_ACTIVATED if called on a capture handle that has been activated, and PCAP_ERROR_CANTSET_TSTAMP_TYPE if the capture device doesn't support setting the time stamp type (only older versions of libpcap will return that; newer versions will always allow the time stamp type to be set to the default type).
This function 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.