pcap_activate(3pcap) — Linux manual page
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)
COLOPHON
This page is part of the libpcap (packet capture library)
project. Information about the project can be found at
⟨http://www.tcpdump.org/⟩. If you have a bug report for this
manual page, see ⟨http://www.tcpdump.org/#patches⟩. This page
was obtained from the project's upstream Git repository
⟨https://github.com/the-tcpdump-group/libpcap.git⟩ on 2024-06-14.
(At that time, the date of the most recent commit that was found
in the repository was 2024-06-04.) If you discover any rendering
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