PCAP_ACTIVATE(3PCAP) PCAP_ACTIVATE(3PCAP)

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_CAPTURE_NOTSUP
Packet capture is not supported on the capture source.

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,
PCAP_ERROR_PERM_DENIED, or PCAP_ERROR_CAPTURE_NOTSUP 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(3PCAP).

SEE ALSO

pcap(3PCAP)

3 June 2024 PCAP_ACTIVATE(3PCAP)