NAME

       pcap_activate - activate a capture handle

SYNOPSIS

       #include <pcap/pcap.h>

       int pcap_activate(pcap_t *p);

DESCRIPTION

       pcap_activate()  is  used  to  activate  a packet capture handle to look at packets on the
       network, with the options that were set on the handle being in effect.

RETURN VALUE

       pcap_activate() returns 0 on success  without  warnings,  a  non-zero  positive  value  on
       success  with  warnings, and a negative value on error.  A non-zero return value indicates
       what warning or error condition occurred.

       The possible warning values are:

       PCAP_WARNING_PROMISC_NOTSUP
              Promiscuous mode was requested, but the capture source doesn't support  promiscuous
              mode.

       PCAP_WARNING_TSTAMP_TYPE_NOTSUP
              The  time stamp type specified in a previous pcap_set_tstamp_type(3PCAP) call isn't
              supported by the capture source (the time stamp type is left as the default),

       PCAP_WARNING
              Another warning condition occurred; pcap_geterr(3PCAP) or pcap_perror(3PCAP) may be
              called  with  p as an argument to fetch or display a message describing the warning
              condition.

       The possible error values are:

       PCAP_ERROR_ACTIVATED
              The handle has already been activated.

       PCAP_ERROR_NO_SUCH_DEVICE
              The capture source specified when the handle was created doesn't exist.

       PCAP_ERROR_PERM_DENIED
              The process doesn't have permission to open the capture source.

       PCAP_ERROR_PROMISC_PERM_DENIED
              The process has permission to open the capture source but doesn't  have  permission
              to put it into promiscuous mode.

       PCAP_ERROR_RFMON_NOTSUP
              Monitor mode was specified but the capture source doesn't support monitor mode.

       PCAP_ERROR_IFACE_NOT_UP
              The capture source device is not up.

       PCAP_ERROR
              Another  error occurred.  pcap_geterr() or pcap_perror() may be called with p as an
              argument to fetch or display a message describing the error.

       If PCAP_WARNING_PROMISC_NOTSUP, PCAP_ERROR_NO_SUCH_DEVICE,  or  PCAP_ERROR_PERM_DENIED  is
       returned,  pcap_geterr()  or pcap_perror() may be called with p as an argument to fetch or
       display an message giving additional details about the problem that might  be  useful  for
       debugging the problem if it's unexpected.

       Additional  warning and error codes may be added in the future; a program should check for
       positive, negative, and zero return codes, and treat all positive return codes as warnings
       and  all  negative  return codes as errors.  pcap_statustostr(3PCAP) can be called, with a
       warning or error code as an argument, to fetch a message describing the warning  or  error
       code.

       If  pcap_activate() fails, the pcap_t * is not closed and freed; it should be closed using
       pcap_close().

SEE ALSO

       pcap(3PCAP)

                                         24 November 2019                    PCAP_ACTIVATE(3PCAP)