pcap_stats(3PCAP) man page

Updated: 25 July 2018 • View in plain textReturn to Main Contents

This man page documents libpcap version 1.10.0 (see also: git master branch, 1.10.4, 1.10.2, 1.10.1, 1.9.1, 1.8.1, 1.7.4, 1.6.2, 1.5.3).

Your system may have a different version installed, possibly with some local modifications. To achieve the best results, please make sure this version of this man page suits your needs. If necessary, try to look for a different version on this web site or in the man pages available in your installation.

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(3PCAP) 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 and returns PCAP_ERROR if there is an error or if p doesn't support packet statistics. If PCAP_ERROR is returned, pcap_geterr(3PCAP) or pcap_perror(3PCAP) may be called with p as an argument to fetch or display the error text.

SEE ALSO

pcap(3PCAP)


COLOPHON

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