Initial s390-tools-2.0.0 import

This commit is based on the s390-tools-1.39.0 version.

Changes on top of s390-tools-1.39.0:

 - Add MIT license to all source files
 - Add LICENSE file
 - Transform REAMDE to README.md (markdown)
 - Add AUTHORS.md file
 - Add CONTRIBUTING.md file
 - Move changelog from README to CHANGELOG.md file

Reviewed-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>

iucvterm/doc/ts-shell/README.ts-shell

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+Terminal server setup
+=====================
+
+This README file provides additional information for configuring
+a terminal server.
+
+
+
+Installation overview
+---------------------
+The s390-tools package installs the ts-shell(1) program along with
+a set of configuration files in `/etc/iucvterm`.
+
+The ts-shell program is pre-configured to connect to any other z/VM
+guest virtual machines (if the z/VM guest virtual machine has the
+respective IUCV authorizations).
+The administrator can change the ts-shell configuration to restrict
+connections to particular z/VM guest virtual machines only.
+
+There are no user authorizations by default. The administrator must
+edit `/etc/iucvterm/ts-authorization.conf` to assign authorizations.
+See the manual page for ts-shell(1) and the `authorization-sample.conf`
+file in the documentation directory for configuration examples.
+
+In addition, the documentation directory also contains the
+iucvconn_on_login sample program that is an alternative to ts-shell.
+
+
+
+
+Setup considerations for the terminal server shell (ts-shell)
+-------------------------------------------------------------
+Adding new ts-shell users
+~~~~~~~~~~~~~~~~~~~~~~~~~
+The ts-shell installation creates a system group ts-shell.
+If you intend to use ts-shell as a login shell for users, ensure that
+these users are all members of ts-shell.  To add existing users to
+group ts-shell, use +usermod -G ts-shell 'username'+.
+
+The ts-shell configuration files and `/var/log/ts-shell` are
+readable only by members of the *ts-shell* group.
+
+
+Enabling terminal session transcripts
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ts-shell(1) can be configured to create transcripts of terminal sessions
+to particular z/VM guest virtual machines. The transcripts are written
+to log files in the `/var/log/ts-shell` directory.
+
+NOTE:	The `/var/log/ts-shell` directory permission has the
+	set-group-ID bit set. Sub-directories that are created by
+	different users will inherit the group ownership of the
+	`/var/log/ts-shell` directory.
+
+See the ts-shell(1) manual page for more information about terminal
+session transcripts.
+
+
+Setting up command completion (optional)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+*ts-shell* supports completion for commands and, if possible, for
+z/VM guest virtual machines. The completion is triggered using the
+'Tab' key. Command completion is an optional feature.
+
+To enable command completion, install one of the following Perl
+ReadLine libraries:
+
+- Term::ReadLine::Gnu
+- Term::ReadLine::Perl
+
+Check your Linux distribution for packages that provide these Perl
+ReadLine interfaces.
+
+
+
+
+Setup a terminal server using the iucvconn_on_login program
+-----------------------------------------------------------
+*iucvconn_on_login* is a sample script that uses the iucvconn(1)
+program to establish an IUCV terminal connection to a Linux
+instance that runs as z/VM guest operating system.
+
+It can be used as an alternative to set up a terminal server.
+The idea of iucvconn_on_login is to establish a terminal connection
+at login time.
+The z/VM guest virtual machine to which iucvconn_on_login will
+connect is the name of the Linux user that logs in.
+
+For example, if you log in as Linux user "lxguest1", iucvconn_on_login
+is started and establishes a terminal connection to the z/VM guest
+virtual machine lxguest1.
+
+
+Adding new users for z/VM guest virtual machines
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+To set up a terminal server using the iucvconn_on_login program,
+create a new Linux user for each z/VM guest virtual machine using
+the z/VM user ID as name. Set the login shell of those users to
+*iucvconn_on_login*.
+
+NOTE:	User names are case-sensitive in Linux.	To ensure consistency,
+	always use either lower or upper case characters for your
+	user names.
+
+To create a new user for z/VM guest virtual machine LXGUEST1
+----
+useradd -s /usr/bin/iucvconn_on_login lxguest1
+----
+
+If you log in as user 'lxguest1' on the terminal server (for example
+using ssh(1)), *iucvconn_on_login* immediately establishes the terminal
+connection to the z/VM virtual guest virtual machine 'lxguest1'.
+
+To access the default terminal ('lnxhvc0') on the Linux instance in
+z/VM guest virtual machine LXGUEST1
+----
+ssh lxguest1@terminal.server
+----
+To access the terminal 'lnxterm' on the Linux instance in
+z/VM guest virtual machine LXGUEST1
+----
+ssh -t lxguest1@terminal.server lnxterm
+----
+For ssh(1), you must use the "-t" parameter if you want to specify an
+alternate terminal identifier. The "-t" parameter ensures that ssh
+starts iucvconn_on_login on a terminal.

iucvterm/doc/ts-shell/authorization-sample.conf

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+# Terminal server authorization configuration
+#
+# See ts-shell(1) manual page for file format.
+
+
+## Examples -- System lists
+
+# alice is authorized to connect to guest1 .. guest5
+alice = list:guest1,guest2,guest3,guest4,guest5
+
+## bob is authorized to connect to systems listed in the file "test-systems.list"
+bob = file:/etc/iucvterm/systems/test-systems.list
+
+# authorize all members of the Linux 'admins' group to connect to systems
+# listed in the file "admin-systems.list"
+@admins = file:/etc/iucvterm/groups/admin-systems.list
+
+
+## Examples -- Regular expressions
+
+# eve has authorization to connect to systems with
+#   a) names starting with 'guest', followed by exactly 2 digits
+#   b) names starting with 'lnx', followed by 5 alphanumeric characters
+eve = regex:(?:guest\d{2}|lnx\w{5})

iucvterm/doc/ts-shell/iucvconn_on_login

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+#! /bin/sh
+#
+# iucvconn_on_login - start terminal connection at login
+#
+# Shell script to connect to a Linux guest operation system
+# using the iucvconn(1) program.
+# The z/VM guest virtual machine to which iucvconn_on_login will connect
+# is the name of the Linux user that logs in.
+#
+# Copyright IBM Corp. 2008, 2017
+#
+# s390-tools is free software; you can redistribute it and/or modify
+# it under the terms of the MIT license. See LICENSE for details.
+#
+prog_name=`basename $0`
+guest_name=${USER:-`whoami 2>/dev/null`}
+terminal=lnxhvc0
+iucvconn=`which iucvconn 2>/dev/null`
+
+__error() {
+	printf "$prog_name: $@\n" >&2
+	exit 1
+}
+
+# check if we have been called with -c <name> to specify an alternate
+# terminal identifier. This can be used by ssh: "ssh -t guest@ts my_term"
+case "$1" in
+  -c) test -n "$2" && terminal=$2 ;;
+esac
+
+test -t 1 || __error "The $prog_name program requires a terminal to run on"
+test "x$guest_name" = x && \
+	__error "Failed to determine the target z/VM guest virtual machine"
+test -x "$iucvconn" || __error "Failed to run the 'iucvconn' program"
+
+printf "$prog_name: Connecting to $guest_name (terminal ID: $terminal)\n\n"
+exec $iucvconn $guest_name $terminal

iucvterm/doc/ts-shell/sample-system.list

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+# Terminal server shell -- system list
+#
+# This file lists z/VM guest virtual machines, each name on a separate line.
+# Empty lines or lines starting with '#' are ignored.
+# See ts-shell(1) for more information.
+#
+#------|<---------------------------------------------------
+LNXSYSA
+LNXSYSB
+LNXSYS01
+LNXSYS42