pcap_set_immediate_mode(3pcap) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | BACKWARD COMPATIBILITY | SEE ALSO | COLOPHON

PCAP_SET_IMMEDIATE_MODE(3PCAP)            PCAP_SET_IMMEDIATE_MODE(3PCAP)

NAME         top

       pcap_set_immediate_mode - set immediate mode for a not-yet-
       activated capture handle

SYNOPSIS         top

       #include <pcap/pcap.h>

       int pcap_set_immediate_mode(pcap_t *p, int immediate_mode);

DESCRIPTION         top

       pcap_set_immediate_mode() sets whether immediate mode should be
       set on a capture handle when the handle is activated.  In
       immediate mode, packets are always delivered as soon as they
       arrive, with no buffering.  If immediate_mode is non-zero,
       immediate mode will be set, otherwise it will not be set.

RETURN VALUE         top

       pcap_set_immediate_mode() returns 0 on success or
       PCAP_ERROR_ACTIVATED if called on a capture handle that has been
       activated.

BACKWARD COMPATIBILITY         top

       This function became available in libpcap release 1.5.0.  In
       previous releases, if immediate delivery of packets is required:

              on FreeBSD, NetBSD, OpenBSD, DragonFly BSD, macOS, and
              Solaris 11, immediate mode must be turned on with a
              BIOCIMMEDIATE ioctl(2), as documented in bpf(4), on the
              descriptor returned by pcap_fileno(3PCAP), after
              pcap_activate(3PCAP) is called;

              on Solaris 10 and earlier versions of Solaris, immediate
              mode must be turned on by using a read timeout of 0 when
              opening the device (this will not provide immediate
              delivery of packets on other platforms, so don't assume
              it's sufficient);

              on Digital UNIX/Tru64 UNIX, immediate mode must be turned
              on by doing a BIOCMBIC ioctl, as documented in
              packetfilter(7), to clear the ENBATCH flag on the
              descriptor returned by pcap_fileno(3PCAP), after
              pcap_activate(3PCAP) is called;

              on Windows, immediate mode must be turned on by calling
              pcap_setmintocopy() with a size of 0.

       On Linux, with previous releases of libpcap, capture devices are
       always in immediate mode; however, in 1.5.0 and later, they are,
       by default, not in immediate mode, so if
       pcap_set_immediate_mode() is available, it should be used.

       On other platforms, capture devices are always in immediate mode.

SEE ALSO         top

       pcap(3PCAP), pcap_create(3PCAP), pcap_activate(3PCAP)

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 2021-04-01.
       (At that time, the date of the most recent commit that was found
       in the repository was 2021-03-31.)  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
       man-pages@man7.org

                             23 August 2018PCAP_SET_IMMEDIATE_MODE(3PCAP)