pcap_activate(3pcap) — Linux manual page


PCAP_ACTIVATE(3PCAP)                                    PCAP_ACTIVATE(3PCAP)

NAME         top

       pcap_activate - activate a capture handle

SYNOPSIS         top

       #include <pcap/pcap.h>

       int pcap_activate(pcap_t *p);

DESCRIPTION         top

       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         top

       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:

              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 default),

              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:

              The handle has already been activated.

              The capture source specified when the handle was created
              doesn't exist.

              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.

       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.

       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().

SEE ALSO         top


COLOPHON         top

       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 2020-09-18.
       (At that time, the date of the most recent commit that was found in
       the repository was 2020-09-15.)  If you discover any rendering prob‐
       lems in this HTML version of the page, or you believe there is a bet‐
       ter 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 man-pages@man7.org

                              24 November 2019          PCAP_ACTIVATE(3PCAP)