[src/trunk]: src/share/man/man9 Explain how the extension bit works in the bi...

[dyoung <dyoung%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/7b1e7b7f75f4
branches:  trunk
changeset: 582929:7b1e7b7f75f4
user:      dyoung <dyoung%NetBSD.org@localhost>
date:      Mon Jul 11 21:59:12 2005 +0000

description:
Explain how the extension bit works in the bitmap that tells which
fields are present.

diffstat:

 share/man/man9/ieee80211_radiotap.9 |  9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)

diffs (23 lines):

diff -r 510f4ba5bace -r 7b1e7b7f75f4 share/man/man9/ieee80211_radiotap.9
--- a/share/man/man9/ieee80211_radiotap.9       Mon Jul 11 21:42:58 2005 +0000
+++ b/share/man/man9/ieee80211_radiotap.9       Mon Jul 11 21:59:12 2005 +0000
@@ -1,4 +1,4 @@
-.\" $NetBSD: ieee80211_radiotap.9,v 1.3 2005/04/25 14:37:49 wiz Exp $
+.\" $NetBSD: ieee80211_radiotap.9,v 1.4 2005/07/11 21:59:12 dyoung Exp $
 .\"
 .\" Copyright (c) 2004 Bruce M. Simpson <bms%spc.org@localhost>,
 .\"                    Darron Broad <darron%kewl.org@localhost>,
@@ -186,7 +186,12 @@
 This bit is reserved for any future extensions to the
 .Vt radiotap
 structure.
-It should not be used at this time.
+A driver sets IEEE80211_RADIOTAP_EXT to extend the it_present bitmap
+by another 64 bits.
+The bitmap can be extended by multiples of 32 bits to 96, 128, 160
+bits or longer, by setting IEEE80211_RADIOTAP_EXT in the extensions.
+The bitmap ends at the first extension field where IEEE80211_RADIOTAP_EXT
+is not set.
 .El
 .Sh EXAMPLES
 Radiotap header for the Cisco Aironet driver: