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Diffstat (limited to 'pcap_stats.3pcap')
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diff --git a/pcap_stats.3pcap b/pcap_stats.3pcap new file mode 100644 index 0000000..a953e21 --- /dev/null +++ b/pcap_stats.3pcap @@ -0,0 +1,99 @@ +.\" @(#) $Header: /tcpdump/master/libpcap/pcap_stats.3pcap,v 1.3 2008-04-06 02:53:22 guy Exp $ +.\" +.\" 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, and (3) all advertising materials mentioning +.\" features or use of this software display the following acknowledgement: +.\" ``This product includes software developed by the University of California, +.\" Lawrence Berkeley Laboratory and its contributors.'' Neither the name of +.\" the University nor the names of its contributors may be used to endorse +.\" or promote products derived from this software without specific prior +.\" written permission. +.\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED +.\" WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF +.\" MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. +.\" +.TH PCAP_STATS 3PCAP "7 September 2009" +.SH NAME +pcap_stats \- get capture statistics +.SH SYNOPSIS +.nf +.ft B +#include <pcap/pcap.h> +.ft +.LP +.ft B +int pcap_stats(pcap_t *p, struct pcap_stat *ps); +.ft +.fi +.SH DESCRIPTION +.B pcap_stats() +fills in the +.B 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. +.PP +.B 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''. +.PP +A +.B struct pcap_stat +has the following members: +.RS +.TP +.B ps_recv +number of packets received; +.TP +.B 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; +.TP +.B ps_ifdrop +number of packets dropped by the network interface or its driver. +.RE +.PP +The statistics do not behave the same way on all platforms. +.B ps_recv +might count packets whether they passed any filter set with +.BR 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. +.B 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 +.B ps_recv +and +.B ps_drop +might, or might not, count packets not yet read from the operating +system and thus not yet seen by the application. +.B 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. +.SH RETURN VALUE +.B pcap_stats() +returns 0 on success and returns \-1 if there is an error or if +.I p +doesn't support packet statistics. +If \-1 is returned, +.B pcap_geterr() +or +.B pcap_perror() +may be called with +.I p +as an argument to fetch or display the error text. +.SH SEE ALSO +pcap(3PCAP), pcap_geterr(3PCAP) |