DEVSERV

DEVSERV V1.3 by Paul Ratcliffe (c) May 2004 DEVSERV comprises an OS/2 server and client library to provide device IOCtl capability for co-operating applications across a TCP/IP network. The program is freeware and as such: USE OF THIS PROGRAM IS ENTIRELY AT YOUR OWN RISK. SERVER The server process is run as a daemon which listens for client calls on TCP port 50000. It accepts client requests and makes calls to device drivers' IOCtl functions using the supplied parameters and data, returning any parameters and data from the driver to the client. Installation requires the daemon to be started either from CONFIG.SYS e.g. RUN=x:\path\DEVSERV.EXE [/P<port>] [/D] or from the command line: DETACH x:\path\DEVSERV.EXE [/P<port>] [/D] where x:\path is the drive and directory in which you installed DEVSERV.EXE /P<port> is an alternative TCP port to listen on /D enables Debug mode The server may also be started non-detached which will allow observation of the debug output - debug mode is pointless if the program is started detached. SECURITY This program can potentially leave your system wide open to attack. Security is a necessary part of installation. A configuration file called DEVSERV.CNF should be created and installed in the same directory as DEVSERV.EXE . If no configuration file is found, DEVSERV will only allow access to the IP address 127.0.0.1 (the local loopback address). The configuration file is checked for changes every time a new client attempts to connect. The configuration file consists of 1 or more lines containing an IP address and a mask in the form: <IP address> <Mask> The mask can be specified to allow access to 1 or more clients using similar IP addressed. This is best explained by way of examples: 192.168.0.1 255.255.255.255 allows access only to 192.168.0.1 192.168.3.0 255.255.255.0 allows access to all of 192.168.3.x 195.8.0.0 255.255.0.0 allows access to all of 195.8.x.x 10.0.0.0 255.0.0.0 allows access to all of 10.x.x.x 0.0.0.0 0.0.0.0 allows access to any host Basically, the client's IP address is logically Anded with the mask and compared to the IP address specified in the configuration file - if it matches, access is granted; if it doesn't, the connection is immediately closed. CLIENT The client application has to be written to make either IOCtl calls to local device drivers or to remote device drivers via the DEVCLI.DLL library. See the sample code REBOOT.C for an example of how this is achieved (you should now see why security is so important!). The client library DEVCLI.DLL must be present in either the same directory as the client application, or preferably somewhere along the LIBPATH. The client is then started almost as normal - there will be some method of telling the application to use a remote host and port though, but this is application dependent. HISTORY Version 1.3 02-05-04 Bug fix for incorrect file handle on automatic reconnect. Version 1.2 29-09-03 Removed reliance on PR0UTIL.DLL - Warp 4 now required. Version 1.1 26-03-02 Configuration file now read when client connects, if it has changed. Version 1.0 14-05-99 Initial release. OTHER This program was initially developed under Warp 3 (without Win-OS/2) and now is developed under Warp 4 using VisualAge C++ 3.0 for OS/2. If you use this program could you please let me know. Also if you have any comments, criticisms, bug reports or anything that could be improved. I will reply to all messages received (remove the numbers from the address). Paul Ratcliffe: Internet: devserv@orac12.clara34.co56.uk78