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 posi-
tive value on success with warnings, and a negative value on error. A
non-zero return value indicates what warning or error condition oc-
curred.
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 sup-
port 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 de-
scribing the error.
If PCAP_WARNING_PROMISC_NOTSUP, PCAP_ERROR_NO_SUCH_DEVICE, or PCAP_ER-
ROR_PERM_DENIED is returned, pcap_geterr() or pcap_perror() may be
called with p as an argument to fetch or display an message giving ad-
ditional 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 pro-
gram 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)
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