Release Notes PN 93000359_Z Digi RealPort Driver Package for Linux dgrp-1.9-39.i386.rpm Tested Linux Distributions: Red Hat Enterprise Linux 2.1, 3, 4, 5.x, 6.x, 7.x Red Hat Linux 7.2, 7.3, 8, 9 Fedora Core 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 17 Mandriva Linux 8.2, 9.0, 9.1, 9.2, 10.0, 10.1, 2006, 2007.1, 2008 SuSE 8.1, 8.2, 9.0, 9.1, 9.2, 9.3, 10.0, 10.1, 10.2, 11.1, 11.2 Debian 3.0.r1, 3.1, 4, 6.0 Ubuntu 7.04, 7.10, 8.04, 8.10, 12.04 Linux Kernels supported: 2.4.x (UP and SMP) 2.6.x (UP and SMP) 3.x.x (UP and SMP) 4.x.x (UP and SMP) RPM Part Number 40002086_Z 06/01/2018 CONTENTS Section Description 1 Introduction 2 Supported Products 3 Enhancements 4 Bug Fixes 5 Known Limitations 6 Additional Information 7 History 1. 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. It is currently supported on the following hardware platforms: o Standard i386/i486 and Pentium PC (x86 32bit) o x86 64bit and is currently supported on the following Linux distributions: o Red Hat Enterprise Linux 2.1, 3, 4, 5.x, 6.x, 7.x o Red Hat Linux 7.2, 7.3, 8, 9 o Fedora Core 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 17, 18 o Mandriva Linux 8.2, 9.0, 9.1, 9.2, 10.0, 10.1, 2006, 2007.1, 2008 o SuSE 8.1, 8.2, 9.0, 9.1, 9.2, 9.3, 10.0, 10.1, 10.2, 11.1, 11.2 o OpenSuSE 42.3 o Debian 3.0.r1, 3.1, 4, 6, 9 o Ubuntu 7.04, 7.10, 8.04, 8.10, 12.04, 14.04, 16.04 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Because of the rapid rate of releases from each respective Vendor, the tested/supported list above quickly becomes out of date.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 2.4.37, 2.6.38, and on various 3.X and 4.X kernels up through 4.16. It is anticipated that this driver will work with Vendor kernel releases newer than the above but cannot be guaranteed 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. Please reference the following number(s) when searching the Digi International web site (www.digi.com) or ftp site (ftp.digi.com) for the latest software package: RPM Part Number: 40002086_Z 2. SUPPORTED PRODUCTS Digi Connect Family Digi EtherLite Family Digi Flex Family Digi One Family Digi CM Family Digi PortServer Family Digi PortServer II Family Digi PortServer TS Family Digi PortServer TS MEI Family Digi PortServer TS W MEI Family Digi PortServer TS M MEI Family Digi PortServer TS H MEI Family Digi PortServer TS P MEI Family IBM LAN Attached RAN 16 3. ENHANCEMENTS o Added IPv6 address driver support for terminal servers (such as the ConnectPort TS 16) that provide them. (RP-99) o Added support for newer kernels through (at least) 4.16. (RP-110) o Updated the in-source openssl package to version 1.0.2o. (This is only used if openssl is not installed on the Linux host when the driver is installed.) (RP-117) o Added "Running the Realport (dgrp) driver on UEFI/SecureBoot systems" section to release notes. (RP-116) 4. BUG FIXES o Fix edge case in port closing code that could lead to a kernel lockup. (RP-113) 5. KNOWN LIMITATIONS o To build the dgrp driver you must have first loaded the matching kernel source tree for your target kernel. o To verify that you have matching kernel source, run "/bin/uname -r" and check to make sure the /usr/src directory has the corresponding linux- directory. o If you are running a prebuilt kernel from a packaged distribution, this typically involves loading the kernel sources from your distribution CD to your system, then using the following commands to do the following: 1. cd /usr/src/linux- 2. make mrproper Clean up any old version files. 3. make oldconfig Make a configuration file to match your running kernel. 4. make dep Create the dependency and version files. Now you can load and build the dgrp driver package. o Occasionally, a Linux Vendor will ship a kernel that simply cannot be autodetected to add the various changes that might be required for that specific kernel. Because of this, there is an option that can be used for both the srpm and tgz to tell the driver package exactly what distribution you have. Currently, the only needed and recognized option is for Red Hat AS/ES/WS 3 and Fedora The flags are: REDHAT_AS_3 / REDHAT_ES_3 / REDHAT_WS_3 FEDORA Examples: To tell the srpm that you have Red Hat AS 3, run this instead: o rpmbuild --rebuild --define DISTRO=REDHAT_AS_3 40002086_Z.src.rpm To tell the tgz that you have Red Hat AS 3, run this during the "configure" phase: o ./configure DISTRO=REDHAT_AS_3 o 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. o There is a known incompatibility/issues with the 2.6.26 kernel. Because of these incompatibility/issues, the 2.6.26 kernel is not supported with this driver. o There is a known incompatibility between our driver and the Red Hat 7.1 distribution which ships 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. o There is a problem with the SBRK ioctl. When a BRK is sent no more data is transmitted until the port is closed. o The ports on EM modules are observed to perform at a slightly reduced speed during throughput testing. o The ditty PRINTER option is not yet supported. o 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. 6. ADDITIONAL INFORMATION o This driver is distributed both as a source RPM and as a compressed tar file of the source. o If you install the source RPM version of the source, it is usually as easy as running the following: 1. rpmbuild --rebuild 40002086_Z.src.rpm 2. rpm -i dgrp-1.9-39.i386.rpm o If you install the compresed tar version of the source, it is usually as easy as running the following: 1. tar xvfz 40002086_Z.tgz 2. cd ./dgrp-1.9 3. ./configure 4. make all 5. make install 6. make postinstall o This package includes several support utilites: o ditty - an stty replacement. o dinc - a cu/tip replacement. o 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. o 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. o 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". o The following manpages are provided: ditty-rp(1), drpd(8), dgrp(8), dgrp_cfg_node(8), dgrp_gui(8). o Red Hat 7.1 -- Kernel Compatibility Issues Some 2.4 kernel-based distributions (Red Hat 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. o Running the Realport (dgrp) driver on UEFI/SecureBoot systems. If your system generates a "Required key not available" message when trying to load the Realport (dgrp) driver, then you are probably running on a UEFI system with the SecureBoot option enabled. If you don't actually require the Secureboot functionality, the simplest soluion is to boot into the UEFI setup menu (typically by pressing a special key like F2 when the system first boots) and disable SecureBoot, after which your locally compiled kernel modules such as the dgrp driver should load and run properly without further effort. If you wish to keep SecureBoot enabled on your system, then you will need to sign kernel modules that you compile locally (such as the dgrp driver) with a Machine Owner Key (MOK). Details: Step 1. Does your system generate a "Required key not available" error message when trying to load the dgrp driver? If not, no further set up action is required on your system; the dgrp driver should load and operate normally. Go to Step 5. Step 2. Have you previously created a Machine Owner Key (MOK) for your computer and do you still have access to its corresponding .der and .priv files? If yes, skip to Step 3. If no, create a new MOK with openssl. For example: openssl req -new -x509 -newkey rsa:2048 \ -keyout MOK.priv -outform DER -out MOK.der \ -nodes \ -days 36500 \ -subj "/CN=My_Own_MOK/" will create two files -- MOK.der and MOK.priv -- which define your new machine owner key. You can replace "36500" with the number of days in the future when you want the MOK to expire and "My_Own_MOK" with some identifying text that will help you recognize and distinguish this particular MOK from others when it is presented to you in a menu. Step 3. Is your MOK already enrolled with your machine's UEFI system? To see what MOKs are currently enrolled: mokutil --list-enrolled or, for an abbreviated version: mokutil --list-enrolled | grep "Subject.*CN" Is your MOK already enrolled with your UEFI system? If so, skip to Step 4. If not, registering a new MOK with your UEFI and boot loader is a three part process: a. Mark the MOK with an import request sudo mokutil --import MOK.der This will request you to supply a password to be used to unlock the MOK during the next step. You can confirm that the new MOK has been imported and is pending enrollment with: sudo mokutil --list-new | grep "Subject.*CN" b. Then, on the next reboot you should be presented with the UEFI MOK Management screen (watch carefully since it may timeout if no action is taken) which will allow you to view and optionally enroll the pending MOK. View and enroll your new key (this will prompt for the password you created in step "a") to complete the MOK enrollment. c. Once the MOK has been accepted, the UEFI MOK Management screen will advise you that a subsequent reboot is required. This time the system should boot directly into Linux. Once the Linux system is back up, confirm that your new MOK has been enrolled with: mokutil --list-enrolled | grep "Subject.*CN" Step 4. Sign the dgrp module with your machine owner key (MOK). Assuming that your MOK.der and MOK.priv files in the current directory ("./"), sign the dgrp module using the "sign-file" script distributed with your kernel. For example: #Ubuntu 16 and similar systems sudo /usr/src/linux-headers-$(uname -r)/scripts/sign-file \ sha256 ./MOK.priv ./MOK.der $(modinfo -n dgrp) #RHEL 7 and similar systems sudo /usr/src/kernels/$(uname -r)/scripts/sign-file \ sha256 ./MOK.priv ./MOK.der $(modinfo -n dgrp) This looks for the "sign-file" script and the "dgrp.ko" module in the expected places for the currently running kernel (hence the "uname -r" and "modinfo -n" in the invocation). You can confirm that the dgrp module has been signed with tail -c 100 $(modinfo -n dgrp) | od -c which should now report "Module signature appended". Step 5. Proceed normally. You should now be able to load and run the dgrp driver and utilities such as "dgrp_gui" normally (without "Required key not available" error messages). Known problems -------------- - As of this writing, Centos 7.5 appears to have a shim bug that makes it fail to notice when new MOKs are pending enrollment, so the MOK Management Screen never appears. We can sign modules with existing MOKs, create new ones and schedule them for enrollment, but we cannot actually enroll new MOKs under CentOS 7.5 Other distributions including RHEL 7.5, Ubuntu 16.04 and OpenSuSE 42.3 work properly and, once a MOK is registered with one of them, all, including CentOS 7.5 can use it. So, until the CentOS 7.5 bug is fixed, enrollment of new MOKs (step 3 above) must be performed on some other OS. Once a MOK is enrolled with the UEFI (a one time process) it can used to sign modules on any OS, including CentOS 7.5. 7. HISTORY o Version 1.9-38 o Updated the in-source openssl package to version 1.0.2l. (This is only used if openssl is not installed on the Linux host when the driver is installed.) (RP-86) o Added support for 4.X kernels. Tested with Ubuntu 14 and 16's 4.4.0-81 kernel, Debian 9.0.0's 4.9.0-3 kernel, OpenSuSE 42.3's 4.4.73.1 kernel, and with a custom 4.11.4 kernel from kernel.org. (NPI-489) o The 3.10.0-514.el7 kernel used in the new RHEL 7.3 release introduced another backport fix related to TTY_CLOSING that caused the Realport driver build to fail. (RP-93) o Version 1.9-36 o Fix an installation problem on systems such as RHEL 7 where /etc/sysconfig/network exists but does not define a NETWORKING environment variable. o Fix a driver build problem on newer kernels, which removed definitions for TTY_CLOSING (in v3.11) and TTY_HW_COOK_IN (in v3.19). Note that Red Hat backported at least some of these definition removals into RHEL 7 kernels starting sometime shortly after 3.10.0-229, so this driver fix is also needed for their newer 3.10 kernels. o Add a description of the rtstoggle option to the ditty man page. o Fix a timing vulerability where an application that fast cycles many port open/closes could occasionally obstruct a close from completing properly, thus leading to a "locked" port. o Fix a problem that could cause the dpa.dgrp utility program to crash with an arithmetic exception if it happened to catch a port during the early stages of an uncompleted open. o Fix the default prefix so that builds from the .tgz distribution file will properly install man pages to /usr/share/man (rather than /share/man). o Version 1.9-35 o Previously there was a time window at the beginning of port opens during which "dgrp_cfg_node" could mistakenly conclude that the corresponding node was idle. If "dgrp_cfg_node uninit" were called during this window it could crash the kernel. A new detection mechanism has been added to cover these conditions. o Version 1.9-34 o Fix driver build problem on systems (such as RHEL 7) that define CONFIG_UIDGID_STRICT_TYPE_CHECKS. o Version 1.9-33 o Added support for the now latest 3.X kernels (from 3.9.0 through 3.14). o Use /tmp/dgrp (rather than /tmp) during installation to avoid the unintended side-effect of modifying the permissions on /tmp. o Fix an initialization problem where first opens of transparent print devices (/dev/pr*) could crash 3.7.0 and newer kernels. o Version 1.9-32 Interim test release o Version 1.9-31 o Added support for 3.X kernels through 3.8. o Changed the dgrp udev rules: a. Use SYMLINK rather than NAME since the latter causes problems on newer systems. b. Add TAG="systemd" so dgrp devices will be recognized on systemd-based distributions (e.g: to start getty's). o Updated configure scripts to add support for newer distributions. o Version 1.9-30 o Added support for kernels up to 2.6.38 o Version 1.9-20 Added support for kernels up to 2.6.28 Added support for many new versions of distributions. Added support for new style "init" scripts in SuSE 11.1 Fixed very rare data corruption issue when under very high loads and multiple PortServers and SMP. o Version 1.9-17 Added support for Red Hat Enterprise 5, Added support for Fedora Core 5, 6 and 7. Fixed problem with registering our devices with sysfs in 2.6.18. Fix compile WARNINGs under 2.6.18. Fix a problem with the RealPort UDEV script when using new versions of UDEV. Fix problem on network disconnect/reconnects where the port would always bring up DTR/RTS, even in cases where the port had both signals down before the network disconnect. o Version 1.9-6 Added support for DPA for RealPort. The utility is installed as /usr/bin/dpa.dgrp Added support for SYSFS in the 2.6 kernels. o Version 1.9-4 Fixed problem with setting baud rates higher than 38400 when using the driver on the IBM pSeries (PPC64) platform. o Version 1.9-1 Fixed driver not working under 2.6.10 kernels and higher. Fixed problem with adding similar node names to the driver. o Version 1.8-1 Added RTS Toggle support to the driver. Added support for the new Alan Cox TTY layer changes in the kernel. Added support for Fedora Core 3, Mandriva Linux 10.1 Added -n option back into the daemon. Added more race condition checking in the tty_close routine and the input routine. Fixed driver not working under 2.6.8 kernels and higher. o Version 1.7-1 Added support for x86 64bit. Added support for Fedora Core 1, Core 2. Updated SSL version to 0.9.7d Removed support for Linux 2.2 kernels. Fixed problem with installing from the tar.gz image. Fixed problem with major() and minor() symbols not being found on very early versions of the 2.4 kernels. Fixed problem on setting the following "o flag" settings: nl<0/1> cr<0/1/2/3> tab<0/1/2/3> bs<0/1> vt<0/1> ff<0/1> Fixed man page of ditty, now correctly describes [-]DTR. Fixed dgrp_cfg_node to correctly set device permissions when using the -m flag. Fixed dgrp_cfg_node to correctly set owner and group when both options are selected. Fixed dgrp_cfg_node to correctly set WAN line speed. Fixed reporting DTR inconsistancy when opening and closing the tty ports very rapidly. Reworked locking in dgrp_tty_write to fix possible deadlock. Fixed possible race condition in tty_close and dgrp_input. Added fix to resolve possible false "RealPort protocol error" detection. Fixed bug on port close. Port might not have gotten drained before the close. o Version 1.6-2 Added support for RealPort with encryption. Added support for Red Hat 9, Suse 8.2, Mandriva Linux 9.1. Added support in ditty for the "startin" and "startout" options. 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. 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. o 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 Red hat 7.3, Suse 8, Mandriva Linux 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. o Version 1.4-0: Improved support for Red Hat 7.1 by offering an architecture to workaround a problematic kernel patch shipped with that distribution. 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 Red Hat 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 Red Hat 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