pcap_stats (3)
Leading comments
Copyright (c) 1994, 1996, 1997 The Regents of the University of California. All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that: (1) source code distributions retain the above copyright notice and this paragraph in its entirety, (2) distributions including binary code include the above copyright notice and this paragraph in its entirety in the documentation or other materials provided with the distribution...
NAME
pcap_stats - get capture statisticsSYNOPSIS
#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.