I've just installed the kismet package from openbsd packages collection
on my acer ferrari laptop with openbsd 4.0.

It seems that the package doesn't support the rt2500 sourcetype and
therefore I thought it would be best if I recompiled my own source.

The divce I'm using is an USB2 D-Link DWL-G122 which gives the
following input to dmesg;
------------------------
rum0: at uhub2 port 6 (addr 2) disconnected
rum0 detached
rum0 at uhub2 port 6
rum0: Ralink 802.11 bg WLAN, rev 2.00/0.01, addr 2
rum0: MAC/BBP RT2573 (rev 0x2573a), RF RT2528, address
00:17:9a:d0:62:e7
-----------------------------

The only change I did to /etc/kismet/kismet.conf was to add the
following line
-----------------------------
source=rt2500,rum0,dlink
-----------------------------

I also tried to configure kismet using rt2500
(source=rt2500,rum0,dlink), rt2573 (source=rt2573,rum0,dlink) and
rt2528 (source=rt2528,rum0,dlink) but it seems noone of those works;

With config source=rt2500,rum0,dlink
------------------------------------------------------------
# kismet
Server options: none
Client options: none
Starting server...
Waiting for server to start before starting UI...
Will drop privs to _kismet (547) gid 547
No specific sources given to be enabled, all will be enabled.
Enabling channel hopping.
Enabling channel splitting.
FATAL: Support for capture source type 'rt2500' was not built. Check
the output from 'configure' for more information about why it might not
have been compiled in.
-------------------------------------------------------------------------------------------


With config source=rt2573,rum0,dlink or source=rt2528,rum0,dlink
-------------------------------------------------------------------------
# kismet
Server options: none
Client options: none
Starting server...
Waiting for server to start before starting UI...
Will drop privs to _kismet (547) gid 547
No specific sources given to be enabled, all will be enabled.
Enabling channel hopping.
Enabling channel splitting.
FATAL: Unknown capture source type 'rt2528' in source
'rt2528,rum0,dlink'
-------------------------------------------------------------------------

So I guessed that because the rt2500 source type wasn't built for this
package, but is indeed supported with kismet, i tried to compile it
myself (only displaying the last lines);
---------------------------------------
# cd kismet-2006-04-R1
# ./configure
...........
...........
checking for strftime... yes
checking for strstr... yes
checking for system-level getopt_long()... yes
checking for stdint.h... (cached) yes
checking for accept() addrlen type... socklen_t
checking for special C compiler options needed for large files... no
checking for _FILE_OFFSET_BITS value needed for large files... no
checking for _LARGE_FILES value needed for large files... no
checking for main in -luClibc++... no
configure: WARNING: uclibc++ not available on this system
checking for main in -lstdc++... no
configure: WARNING: libstdc++ not available on this system
configure: error: Neither uclibc uClibc++ or standard gcc stdc++
libraries found.
---------------------------------------------------------------

So I figured I was missing some package from the OpenBSD packages
collection for openbsd4.0. and this is what I've installed now;
---------------------------
# pkg_info
bash-3.1.17 GNU Bourne Again Shell
bzip-0.21 block-sorting file compressor, encumbered
bzip2-1.0.3 block-sorting file compressor, unencumbered
expat-2.0.0 XML 1.0 parser written in C
g++-3.3.6p2 GNU compiler collection: C++ compiler
gcc-3.3.6p2 GNU compiler collection: core C compiler
gettext-0.14.5p1 GNU gettext
gnutls-1.0.25p0 GNU Transport Layer Security library
kismet-200508R1p1 802.11 layer2 wireless network detector, sniffer,
and IDS
libgcrypt-1.2.0p1 crypto library based on code used in GnuPG
libgpg-error-1.1p0 error codes for GnuPG related software
libiconv-1.9.2p3 character set conversion library
libslang-1.4.9p3 stack-based interpreter for terminal applications
libst-1.4p0 threaded library for writing Internet applications
libstdc++-3.3.6p0 GNU compiler collection: C++ compiler library
mtr-0.71-no_x11 Matt's traceroute - network diagnostic tool
nano-1.2.5-slang small, easy to use editor
opencdk-0.5.5p0 Open Crypto Development Kit
wget-1.10.2p0 retrieve files from the web via HTTP, HTTPS and FTP
-------------------------------------------------------------------------------


And I couldn't find uClibc++ from the packages collection (
ftp://ftp.su.se/pub/OpenBSD/4.0/packages/i386/ ) but I sure found
uClibc++-0.2.1 by googling the web so I downloaded it, and tried to
compile it;
----------------------------------------------
# cd uClibc++-0.2.1
# make menuconfig
"./Rules.mak", line 24: Need an operator
"./Rules.mak", line 26: Need an operator
"./Rules.mak", line 58: Need an operator
"./Rules.mak", line 70: Missing dependency operator
"./Rules.mak", line 71: Need an operator
"./Rules.mak", line 72: Need an operator
"./Rules.mak", line 89: Need an operator
"./Rules.mak", line 107: Missing dependency operator
"./Rules.mak", line 110: Need an operator
"./Rules.mak", line 112: Need an operator
"./Rules.mak", line 114: Missing dependency operator
"./Rules.mak", line 116: Need an operator
"./Rules.mak", line 119: Missing dependency operator
"./Rules.mak", line 121: Need an operator
"./Rules.mak", line 135: Missing dependency operator
"./Rules.mak", line 137: Need an operator
"./Rules.mak", line 138: Missing dependency operator
"./Rules.mak", line 140: Need an operator
"./Rules.mak", line 146: Missing dependency operator
"./Rules.mak", line 148: Need an operator
"./Rules.mak", line 149: Missing dependency operator
"./Rules.mak", line 151: Missing dependency operator
"./Rules.mak", line 153: Need an operator
"./Rules.mak", line 154: Need an operator
Fatal errors encountered -- cannot continue
--------------------------------------------------------------------------------------------------------

Any ideas on how I should proceed? Something I've missed? How I could
get rt2500-chipset to work with OpenBSD40?

After some research I just found out that the sourcetype
"radiotap_bsd_b" works very well with my rum0 device. I have tried it
and yes, I did recieve alot of IV's.

source=radiotap_bsd_b,rum0,dwl_g122

Works like a charm. Didn't need to install any other packages.
Perhaps this will help someone else.