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
The possible warning values are:
Promiscuous mode was requested, but the capture source
doesn't support promiscuous mode.
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
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
The possible error values are:
The handle has already been activated.
The capture source specified when the handle was created
The process doesn't have permission to open the capture
The process has permission to open the capture source but
doesn't have permission to put it into promiscuous mode.
Monitor mode was specified but the capture source doesn't
support monitor mode.
The capture source device is not up.
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
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().
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 2021-08-27.
(At that time, the date of the most recent commit that was found
in the repository was 2021-08-17.) If you discover any rendering
problems in this HTML version of the page, or you believe there
is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
24 November 2019 PCAP_ACTIVATE(3PCAP)