xref: /freebsd/contrib/libpcap/pcap_setdirection.3pcap (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
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PCAP_SETDIRECTION 3PCAP "5 March 2022"
NAME
pcap_setdirection - set the direction for which packets will be captured
SYNOPSIS
#include <pcap/pcap.h>

int pcap_setdirection(pcap_t *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 (3PCAP) or pcap_perror (3PCAP) may be called with p as an argument to fetch or display the error text.
SEE ALSO
pcap (3PCAP)