PCAP_SETDIRECTION(3)   FreeBSD Library Functions Manual   PCAP_SETDIRECTION(3)

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(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)