pcap_set_immediate_mode(3) - NetBSD Manual Pages

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PCAP_SET_IMMEDIATE_MODE(3)                          PCAP_SET_IMMEDIATE_MODE(3)




NAME

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


SYNOPSIS

       #include <pcap/pcap.h>

       int pcap_set_immediate_mode(pcap_t *p, int immediate_mode);


DESCRIPTION

       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

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


BACKWARD COMPATIBILITY

       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(@MAN_DEVICES@), on the descriptor
              returned by pcap_fileno(3), after pcap_activate(3) 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(3), after pcap_activate(3) 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

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



                                22 August 2018      PCAP_SET_IMMEDIATE_MODE(3)