pcap_setdirection(3) pcap_setdirection(3)
NAME
pcap_setdirection - set the direction for which packets will be
captured
SYNOPSIS
#include <pcap/pcap.h>
pcap_setdirection(3) *p, pcap_direction_t d);
DESCRIPTION
pcap_setdirection() is used to specify a direction that packets will be
captured. d is one of the constants PCAP_D_IN, PCAP_D_OUT or
PCAP_D_INOUT. PCAP_D_IN will only capture packets received by the
device, PCAP_D_OUT will only capture packets sent by the device and
PCAP_D_INOUT will capture packets received by or sent by the device.
PCAP_D_INOUT is the default setting if this function is not called.
pcap_setdirection() isn't necessarily fully supported on all platforms;
some platforms might return an error for all values, and some other
platforms might not support PCAP_D_OUT.
This operation is not supported if a ``savefile'' is being read.
RETURN VALUE
pcap_setdirection() returns 0 on success, PCAP_ERROR_NOT_ACTIVATED if
called on a capture handle that has been created but not activated, or
PCAP_ERROR on other errors. 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_setdirection(3)
libpcap 1.11.0 - Generated Tue Sep 15 09:19:11 CDT 2026