pcap_setdirection — Npcap API

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.