PCAP_STATS(3) FreeBSD Library Functions Manual PCAP_STATS(3)
NAME
pcap_stats - get capture statistics
SYNOPSIS
#include <pcap/pcap.h>
int pcap_stats(pcap_t *p, struct pcap_stat *ps);
DESCRIPTION
pcap_stats() fills in the struct pcap_stat pointed to by its second
argument. The values represent packet statistics from the start of the
run to the time of the call.
pcap_stats() is supported only on live captures, not on ``savefiles''; no
statistics are stored in ``savefiles'', so no statistics are available
when reading from a ``savefile''.
A struct pcap_stat has the following members:
ps_recv
number of packets received;
ps_drop
number of packets dropped because there was no room in the
operating system's buffer when they arrived, because
packets weren't being read fast enough;
ps_ifdrop
number of packets dropped by the network interface or its
driver.
The statistics do not behave the same way on all platforms. ps_recv
might count packets whether they passed any filter set with
pcap_setfilter(3) or not, or it might count only packets that pass the
filter. It also might, or might not, count packets dropped because there
was no room in the operating system's buffer when they arrived. ps_drop
is not available on all platforms; it is zero on platforms where it's not
available. If packet filtering is done in libpcap, rather than in the
operating system, it would count packets that don't pass the filter.
Both ps_recv and ps_drop might, or might not, count packets not yet read
from the operating system and thus not yet seen by the application.
ps_ifdrop might, or might not, be implemented; if it's zero, that might
mean that no packets were dropped by the interface, or it might mean that
the statistic is unavailable, so it should not be treated as an
indication that the interface did not drop any packets.
RETURN VALUE
pcap_stats() returns 0 on success, PCAP_ERROR_NOT_ACTIVATED if called on
a capture handle that has been created but not activated, or PCAP_ERROR
if there is another error or if p doesn't support packet statistics. 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.
SEE ALSO
pcap(3)
5 March 2022 PCAP_STATS(3)