pcap_activate(3)
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,
PCAP_WARNING_PROMISC_NOTSUP
on success on a device that doesn't support promiscuous mode if
promiscuous mode was requested,
PCAP_WARNING_TSTAMP_TYPE_NOTSUP
on success if the time stamp type specified in a previous
pcap_set_tstamp_type()
call isn't supported by the capture source (the time stamp type is
left as the default),
PCAP_WARNING
on success with any other warning,
PCAP_ERROR_ACTIVATED
if the handle has already been activated,
PCAP_ERROR_NO_SUCH_DEVICE
if the capture source specified when the handle was created doesn't
exist,
PCAP_ERROR_PERM_DENIED
if the process doesn't have permission to open the capture source,
PCAP_ERROR_PROMISC_PERM_DENIED
if the process has permission to open the capture source but doesn't
have permission to put it into promiscuous mode,
PCAP_ERROR_RFMON_NOTSUP
if monitor mode was specified but the capture source doesn't support
monitor mode,
PCAP_ERROR_IFACE_NOT_UP
if the capture source is not up, and
PCAP_ERROR
if another error occurred.
If
PCAP_WARNING
or
PCAP_ERROR
is returned,
pcap_geterr()
or
pcap_perror()
may be called with
p
as an argument to fetch or display a message describing the warning or
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.