Release Notes PN 93000359G Digi RealPort Linux Version 1.6 Release 2 Software Package 40002086G 08/13/2003 _________________________________________________________________ Contents 1. Introduction 2. Supported Products 3. Enhancements 4. Bug Fixes 5. Know Limitations 6. Printers 7. Ditty 8. Configuration and Startup 9. Documentation 10. History _________________________________________________________________ Introduction Digi RealPort Linux is a driver package for Digi's Ethernet-based Serial Products. It is assumed that TCP/IP is running on the system and is properly configured. It is also useful, though not necessary, for the Wish package to be installed, or some other TCL interpreter, in order to use the RealPort Manager configuration tool. Supported Linux Kernels * 2.4-based kernels on Intel and Alpha platforms * 2.2-based kernels on Intel and Alpha platforms * 2.0-based kernels equal or newer than 2.0.36 on Intel platforms The driver package has been tested with the following unmodified Linux distributions: * RedHat Advanced Server 2.1 * RedHat 9.0 * RedHat 8.0 * RedHat 7.3 * RedHat 7.2 * RedHat 7.1 * RedHat 7.0 * RedHat 6.2 * SuSe 8.2 * SuSe 8.1 * SuSe 8.0 * SuSe 7.1 * SuSe 7.0 * SuSe 6.4 * Mandrake 9.1 * Mandrake 9.0 * Mandrake 8.2 * Mandrake 8.0 * Mandrake 7.2 * SCO Linux 4.0 (Uses Suse 8.2 kernel) * Caldera OpenLinux 3.1.1 server * Caldera OpenLinux 3.1.1 workstation * Caldera OpenLinux 3.1 server * Conectiva 6.0 * TurboLinux 7.0 workstation * TurboLinux 6.1 workstation * TurboLinux 6.0 server * Debian 3.0r1 NOTE: Because of the rapid rate of releases from each respective Vendor, the tested/supported list above quickly becomes out of date. This driver package has been tested and verified working for kernels up to and including version 2.4.22 from kernel.org. It is anticipated that this driver will work with Vendor kernel releases of up to 2.4.22, but cannot be guarenteed because each respective Vendor can, and does, add their own various changes/patches to the stock kernel.org kernel. These additional Vendor patches to the stock kernel.org linux kernel can cause unforeseen incompatibilities with this driver. Supported Products * Digi One RealPort Device Server * Digi One EM * Digi One IA * Digi One IA RealPort * Digi One RealPort * Digi One SP * Digi One TS * Digi Flex * PortServer 8 * PortServer 16 * PortServer II 16 Rack * PortServer II 16 * PortServer TS 2 * PortServer TS 4 * PortServer TS 8 * PortServer TS 16 * PortServer TS 16 Rack * EtherLite 2 * EtherLite 8 * EtherLite 16 * EtherLite 32 * EtherLite 80 * EtherLite 160 * EtherLite 162 Enhancements * Added support for RealPort with encryption. * Added support for Redhat 9.0, Suse 8.2, Mandrake 9.1, and SCO Linux 4.0 * Added support in ditty for the "startin" and "startout" options. * Added support for Linux beta 2.6.0 kernels up to and including the "test2" version. * dgipserv - Added support to set unassigned Ethernet address, support for setting the tftp server IP address, support for setting virtual ports and virtual ports timeouts, and support for setting optimize to throughput or latency. Bug Fixes * Fixed "configure" script problem where modversion.h wasn't being found in the proper location. * Fixed include file problem where the driver would not compile correctly under some newer versions of the 2.4 kernel. * Fixed problem with an incorrect assert message being generated. Known Limitations * The procedure to build this package using the .tgz (non-rpm) has changed. You *must* run "./configure" at the toplevel before trying to compile the package with a "make". * To install this package correctly under SuSE 8.0, a symlink from /usr/lib/libncurses.so.2.1 to /usr/lib/libncurses.so needs to be created. Simply run this command: ln -s /usr/lib/libncurses.so.2.1 /usr/lib/libncurses.so then start the installation of the Realport package. * There is a known incompatibility between our driver and some Linux distributions which ship a custom modified 2.4 kernel. The problem manifests itself with device driver usage counts which never decrease, possible loss of use of some numbers of ports, and possible system instability. The root cause is in the modification of the kernel, which makes a change to an internal interface and introduces an incompatibility. The largest distribution affected by this issue is RedHat 7.1. It is important to note that RedHat 7.2 does NOT have this issue. See the RedHat 7.1 section below for details. * There is a problem with the SBRK ioctl. When a BRK is sent no more data is transmitted until the port is closed. * The ports on EM modules are observed to perform at a slightly reduced speed during throughput testing. * The ditty PRINTER option is not yet supported. * If this RealPort driver package detects that the system's OpenSSL layer is too old to be used reliably, the driver will compile its own more current version of OpenSSL. This compile could take a considerable amount of time, anywhere from 5 to 60 minutes extra. The extra time it takes depends upon how fast of system the driver is being compiled on. Printers Transparent print now works, as of driver version 1.4.3 or higher. Ditty The ditty program provided with this package is named "ditty-rp" so as to not interfere with any other versions of ditty installed on the system (for use with other Digi products). Configuration and Startup There is a package of configuration tools provided that are, by default, located in the /usr/bin/dgrp/config directory. There are scripts for using the command line to add and remove products, as well as the RealPort Manager. This is essentially a graphical front end for the scripts and a visual tool for monitoring individual serial ports. The software package includes two startup scripts in either the /etc/rc.d/init.d or /etc/init.d directories named "dgrp_daemon" and "dgrp_ditty". These scripts will be executed at startup automatically if the "chkconfig" tool is present on the system during the post installation phase of the driver install. Otherwise, these scripts must be manually added to the system startup. To load and initialize the driver by hand, execute "dgrp_daemon start". To stop the driver daemons and unload the driver, execute "dgrp_daemon stop" followed by "rmmod dgrp". Documentation The following manpages are provided: ditty-rp(1), drpd(8), dgrp(8), dgrp_cfg_node(8), dgrp_gui(8). RedHat 7.1 -- Kernel Compatibility Issues Some 2.4 kernel-based distributions (RedHat 7.1 included) have a patch applied to them which modifies the behavior of Linux when an open of a serial port is canceled (for instance, if an application is waiting for the carrier signal and a user hits CTRL-C to kill the application). With this behavior change, the device driver is unable to cleanup its internal data structures and the sane functioning of the driver is compromised. The classic symptom of this problem is that the command "lsmod", which (among other things) will return a count of the applications using the device driver, will return a non-zero value even if all applications associated with the serial ports are killed. Unfortunately, it is impossible (from within the device driver) to determine which behavior is implemented in the running kernel. However, Digi now provides a workaround to allow customers with this problem to change the Digi behavior to be compatible with these "patched" kernels. To enable the change which provides alternate behavior when a serial "open" call fails, execute the following after the device driver is loaded: echo "alt_fail_open=1" > /proc/dgrp/info To return to the standard behavior, execute: echo "alt_fail_open=0" > /proc/dgrp/info To examine the current state of this driver tuning variable: cat /proc/dgrp/info Unfortunately, this command must be executed each time the device driver is loaded (i.e. when the system is booted). To make this process easier for customers, the Digi standard driver startup tools will execute the command on the customer's behalf when it loads the driver if the following command is executed: touch /usr/bin/dgrp/config/alt_fail_open This command will create a file in your file system. The Digi tools, if they detect the existence of this file, will enable the "alt_fail_open" behavior on your behalf at every system boot. History * Version 1.5-0: + Added Transparent print support. Please read the man page for "dgrp", under section "Transparent Print" for more information. Changed package install to run a "configure" script first before trying to compile the driver. The script should catch most of the problems that the compile might have beforehand, and give a much better description of the problem than a cryptic compiler error message. Added Support for Redhat 7.3, Suse 8.0, Mandrake 8.2, and Caldera OpenLinux 3.1.1 (server and workstation) Fixed off-by-one error in the tbuf parsing. This bug, although very rare, could have caused the kernel to panic, or cause random kernel memory corruption. + Version 1.4-0: o Improved support for RedHat 7.1 by offering an architecture to workaround a problematic kernel patch shipped with that distribution. See the RedHat 7.1 section below for details. Added support for EL-8, EL-16 and EL-32. Added the "dgelreset" application, which allows one to reset an EtherLite regardless of whether it is running RealPort compatible firmware, and without having to specify a MAC address. Added "MODULE LICENSE" information to the device driver, in order to comply with anti-tainting policies in newer 2.4 Linux kernels. Modified driver to prevent port "hangup" in the event that the daemon dies. Added TCFLSH handling to "ditty-rp"... previously, the "flushin", "flushout", and "flush" options didn't work. o Version 1.3-0: Added full support for Digi's EtherLite products which are running Digi RealPort compatible firmware, including the EtherLite 2, EtherLite 160, EtherLite 162, and the EtherLite 80. Fixed a kernel panic if a port is open, `dgrp_daemon stop` is executed, and a program then goes to write to the still open port. Now write returns EIO in that condition. Fixed a select(2) problem in kernel 2.2.15 and later of 2.2.x kernels which could cause programs like telnet or ssh to appear to hang until a key is pressed. Fixed a data loss problem which would manifest itself when exactly four kilobytes of data were transmitted after a port was opened. Added /lib/modules/`uname -r`/kernel/drivers/char to the list of locations that the kit will test for existence when trying to find an appropriate location to install the driver module, in response to testing in native 2.4 kernel-based distributions. o Version 1.2-2: Increased support for Digi's ethernet-based serial connectivity family; including Digi One, EtherLite, and PortServer products. Added support for arbitrary integer baud rates via the "ditty-rp" utility. Detailed information about the type and version of configured remote devices was made available via the "/proc/dgrp/nodeinfo" file. A memory corruption problem which would cause sysem instability was eliminated. Unexpected pauses and loss in port traffic as a result of a network buffer overflow were resolved. o Version 1.1-7: Added 2.4 kernel support. Removed references to invalid email addresses. Driver now handles RedHat 7.0 (kgcc vs. gcc). The GUI tool now displays the DCD signal when viewing ports. RealPort ports now match other Linux serial ports for default settings, as well as making all port settings "sticky". As a result of this change, CLOCAL is now on by default. Configuration scripts remove the "/dev" files if a PortServer is unconfigured. Only physical line drops are detected as a "hangup" condition... the driver would previously treat a change from CLOCAL to -CLOCAL as a carrier transition. Startup scripts are installed in "/etc/init.d" if "/etc/rc.d/init.d" does not exist. RPM installation will not "error out" if "chkconfig" (a RedHat tool) does not exist on the system. A message was added to the RPM installation to communicate to users whether the installation scripts were added or not. On newer systems, RPM would inadvertently strip the driver module of its symbols, causing it to fail. The module is no longer stripped. o Version 1.0-0: Added a new proc file: /proc/dgrp/info. This file allows one to determine the value of a number of state variables associated with the driver, including the driver revision. Continued refinement of the GUI. The GUI is now distributed as a single file, rather than a collection of "tcl" files. dgrp_cfg_node now does validity checking of its ID and COUNT parameters. o Version 0.1-7: A first pass at cleaning up the code was completed for beta release. All driver build warnings have been fixed. Appropriate part numbers have been correctly placed in the appropriate documents. A useful driver revision number is now placed in the console log when the module is loaded. o Version 0.1-5: a minimum break time of 250ms is now enforced. A PPP hang problem was resolved. Continued enhancements of the packaging. o Version 0.1-4: decided to install dgrp.o to the /usr/bin/dgrp directory, and then link in the postinstall phase to a suitable /lib/modules/*/misc directory. This avoids the problem of having the path to dgrp.o hardcoded in the spec file. o Version 0.1-3: added new scripts to autoload the driver on system startup and initialize any PortServers configured in /etc/dgrp.backing.store o Version 0.1-1 - pilot release in January 1999