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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | SEE ALSO | COLOPHON |
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PCAP_STATS(3PCAP) PCAP_STATS(3PCAP)
pcap_stats - get capture statistics
#include <pcap/pcap.h>
int pcap_stats(pcap_t *p, struct pcap_stat *ps);
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.
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(3PCAP) or pcap_perror(3PCAP) may be called with p as
an argument to fetch or display the error text.
pcap(3PCAP)
This page is part of the libpcap (packet capture library)
project. Information about the project can be found at
⟨http://www.tcpdump.org/⟩. If you have a bug report for this
manual page, see ⟨http://www.tcpdump.org/#patches⟩. This page
was obtained from the project's upstream Git repository
⟨https://github.com/the-tcpdump-group/libpcap.git⟩ on 2023-12-22.
(At that time, the date of the most recent commit that was found
in the repository was 2023-12-13.) If you discover any rendering
problems in this HTML version of the page, or you believe there
is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
man-pages@man7.org
5 March 2022 PCAP_STATS(3PCAP)
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HTML rendering created 2023-12-22 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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