#! /bin/bash # $Id$ # Copyright (C) 2004 Enrico Scholz # # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; version 2 of the License. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program; if not, write to the Free Software # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. : ${UTIL_VSERVER_VARS:=/usr/lib/util-vserver/util-vserver-vars} test -e "$UTIL_VSERVER_VARS" || { echo "Can not find util-vserver installation; aborting..." >&2 exit 1 } . "$UTIL_VSERVER_VARS" . "$_LIB_FUNCTIONS" function showHelp() { echo \ $"Usage: /usr/sbin/chcontext [--cap [!]] [--secure] [--ctx ] [--disconnect] [--domainname ] [--hostname ] [--flag +] [--silent] [--] command arguments ... chcontext allocate a new security context and executes a command in that context. By default, a new/unused context is allocated --cap CAP_NAME Add a capability from the command. This option may be repeated several time. See /usr/include/linux/capability.h In general, this option is used with the --secure option --secure removes most critical capabilities and --cap adds specific ones. --cap !CAP_NAME Remove a capability from the command. This option may be repeated several time. See /usr/include/linux/capability.h --ctx num Select the context. On root in context 0 is allowed to select a specific context. Context number 1 is special. It can see all processes in any contexts, but can't kill them though. Option --ctx may be repeated several times to specify up to 16 contexts. --disconnect Start the command in background and make the process a child of process 1. --domainname new_domainname Set the domainname (NIS) in the new security context. Use "none" to unset the domain name. --flag Set one flag in the new or current security context. The following flags are supported. The option may be used several time. fakeinit: The new process will believe it is process number 1. Useful to run a real /sbin/init in a vserver. lock: The new process is trapped and can't use chcontext anymore. sched: The new process and its children will share a common execution priority. nproc: Limit the number of process in the vserver according to ulimit setting. Normally, ulimit is a per user thing. With this flag, it becomes a per vserver thing. private: No one can join this security context once created. ulimit: Apply the current ulimit to the whole context --hostname new_hostname Set the hostname in the new security context This is need because if you create a less privileged security context, it may be unable to change its hostname --secure Remove all the capabilities to make a virtual server trustable --silent Do not print the allocated context number. Report bugs to <$PACKAGE_BUGREPORT>." exit $1 } function showVersion() { echo \ $"chcontext $PACKAGE_VERSION -- allocates/enters a security context This program is part of $PACKAGE_STRING Copyright (C) 2003 Enrico Scholz This program is free software; you may redistribute it under the terms of the GNU General Public License. This program has absolutely no warranty." exit $1 } function cleanup() { if test -d "$tmpdir"; then local S="$tmpdir"/socket test ! -S "$S" || $_KEEP_CTX_ALIVE --quit "$S" &>/dev/null rm -rf "$tmpdir" fi } $_VSERVER_INFO - FEATURE migrate || exec $_CHCONTEXT_COMPAT "$@" tmp=$(getopt -o + --long cap:,ctx:,disconnect,domainname:,flag:,hostname:,secure,silent,help,version -n "$0" -- "$@") || exit 1 eval set -- "$tmp" OPT_CAPS=() OPT_CTX= OPT_DISCONNECT= OPT_FLAGS=() OPT_SECURE= OPT_SILENT= while true; do case "$1" in --help) showHelp $0 ;; --version) showVersion ;; --cap) OPT_CAPS=( "${OPT_CAPS[@]}" "$1" ); shift;; --ctx) OPT_CTX=$1; shift;; --disconnect) OPT_DISCONNECT=1; --domainname) OPT_DOMAINNAME=$1; shift;; --hostname) OPT_HOSTNAME=$1; shift;; --flag) OPT_FLAGS=( "${OPT_FLAGS[@]}" "$1" ); shift;; --secure) OPT_SECURE=1;; --silent) OPT_SILENT=1;; --) shift; break;; *) echo $"chcontext: internal error; arg=='$1'" >&2; exit 1;; esac shift done tmpdir= tmpdir=$(mktemp -d /tmp/chcontext.XXXXXX) trap "cleanup" EXIT xid=$($_VCONTEXT --create ${OPT_SILENT:+--silent} ${OPT_CTX:+--xid "$OPT_CTX"} -- $_CTX_KEEP_ALIVE --socket "$tmpdir"/socket --timeout 60) rc=$? test "$rc" -ne 255 || echo $"chcontext: Failed to create the context; aborting..." >&2 exit 1 } test "$rc" -ne 254 || xid=$OPT_CTX test "$xid" || { echo $"chcontext: Failed to determine context xid; aborting..." >&2 exit 1 } set -e test "$rc" -ne 0 || { rm -rf "$tmpdir" unset rc } if test "$rc" -ne 254; then $_VATTRIBUTE --xid "$xid" -s \ ${OPT_CAPS:+--cap "${OPT_CAPS[@]}"} ${OPT_FLAGS:+--flag "${OPT_FLAGS[@]}"} \ ${OPT_SECURE:+--secure} $_VUNAME --xid "$xid" -s \ ${OPT_DOMAINNAME:+--domainname "$OPT_DOMAINNAME"} \ ${OPT_HOSTNAME:+--nodename "$OPT_HOSTNAME"} fi exec $_VCONTEXT --migrate --xid "$xid" \ ${OPT_SILENT:+--silent} \ ${OPT_DISCONNECT:+--disconnect} \ ${rc:--syncsock "$tmpdir"/socket} \ -- "$@"