Substantially flesh out the spicedummy.sh script.

This makes it more user friendly and enables it to run from
an installed location, rather than just the source tree.

This also adds the ability to add '--query hostname' which
will query an XDMCP server for a session, rather than relying
on xinit.
Acked-by: Frediano Ziglio <fziglio@redhat.com>

README

@@ -91,8 +91,10 @@ To use this driver, simply add:
 
 to the configure line.  This will build the Xorg driver.  A simplistic
 example is included showing the general concepts of using this driver.
-Refer to the spice-video-dummy/spicedummy.sh bash script for more
-information.
+You can try this by running:
+  spice-video-dummy/spicedummy.sh
+
+That bash script is recommended reading.
 
 
 Using code coverage (gcov)

spice-video-dummy/spicedummy.sh

 #!/bin/bash
 #  Example script that shows how to launch the spice video driver
-#   and attach x11spice to it.  This is not meant for production
-#   purposes.
+#   and attach x11spice to it.
+#  This is not recommended for production use without some study
+#   and understanding of what is happening.  At the very least,
+#   any user should explore using ssl to encrypt the x11spice traffic.
 
+# Note on XDMCP
+#   To use XDMCP on fairly modern systems, you need to make 2 changes.
+# First, you need to edit /etc/gdm/custom.conf and under the
+#  [xdmcp]
+# section, add:
+#  Enabled=true
+# Next, you more than likely want to avoid policy kit complaining
+#  about color devices.  A hint on how to this can be found here:
+#    http://c-nergy.be/blog/?p=12043
+# Also note that if you are running inside a virtual machine,
+#  you will most likely not get 'real' hardware acceleration,
+#  and a result, a gnome session will generally fail with a 'Mr. Yuk'
+#  screen.
+
+usage()
+{
+    cat << EOF
+Usage:
+  spicedummy.sh [--display :n] [--query hostname] [x11spice-arguments]
+If no x11spice arguments are provided, a random password will be
+  generated and passed in along with --allow-control.
+If no display is given, :2 will be used.
+If --query is provided, Xorg will be started with a request to query the
+  given host via XDMCP.  Otherwise, xinit will be invoked.
+Note that XDMCP usually requires some further configuration.
+EOF
+    exit 1
+}
+
+# Parse arguments
 export DISPLAY=:2
+while [ $# -gt 0 ] ; do
+    case "$1" in
+    --display)
+        shift;
+        if [ $# -lt 1 ] ; then
+            echo Error: no display given
+            usage
+        fi
+        export DISPLAY="$1"
+        shift;
+        ;;
+    --query)
+        shift;
+        if [ $# -lt 1 ] ; then
+            echo Error: no hostname given
+            usage
+        fi
+        xdmcp="$1"
+        shift;
+        ;;
+    --help)
+        usage;
+        ;;
+    *)  args="$args $1"
+        shift;
+        ;;
+    esac
+done
+
+if [ -z "$args" ] ; then
+    # Generate a random password
+    password=`hexdump -n2 -e '2/1 "%02x"' /dev/urandom`
+    args="--password=$password --allow-control"
+fi
 
-password=`hexdump -n2 -e '2/1 "%02x"' /dev/urandom`
 zerodir=`dirname $0`
-dummydir=`(cd $zerodir; pwd)`
-xmodules=`Xorg -showDefaultModulePath 2>&1`
+dummydir=`(cd "$zerodir"; pwd)`
+if [ -x /usr/libexec/Xorg ] ; then
+    xorg=/usr/libexec/Xorg
+else
+    xorg=`which Xorg`
+fi
+xmodules=`"$xorg" -showDefaultModulePath 2>&1`
+x11spice=`which x11spice`
+if [ ! -x "$x11spice" ] ; then
+    x11spice="$dummydir/../src/x11spice"
+fi
+
+if [ ! -x "$x11spice" ] ; then
+    echo "Error: x11spice not found in the path."
+    echo "Cowardly refusing to start"
+    exit 1
+fi
+
+# Make sure xinit is likely to work
+if [ -z "$xdmcp" -a ! -f ~/.xinitrc ] ; then
+    type xterm >/dev/null 2>&1
+    if [ $? -ne 0 ] ; then
+        echo "Error: You do not have either ~/.xinitrc or xterm available."
+        echo "Cowardly refusing to start."
+        exit 1
+    fi
+fi
+
+# Build up an Xorg command line
+xcmd="\"$xorg\" $DISPLAY -novtswitch vt00"
+if [ "$zerodir" = "/usr/bin" ] ; then
+    xcmd+=" -config spicedummy.conf"
+else
+    xcmd+=" -modulepath \"$dummydir/src/.libs,$xmodules\""
+    xcmd+=" -config \"$dummydir/X11/spicedummy.conf\""
+fi
 
 # Start Xorg
-xinit -- `which Xorg` $DISPLAY \
-    -modulepath "$dummydir/src/.libs,$xmodules" \
-    -config "$dummydir/spicedummy.conf" &
-xpid=$!
-sleep 1
+if [ -n "$xdmcp" ] ; then
+    export XAUTHORITY=`mktemp`
+    chmod og-rwx $XAUTHORITY
+    xauth -f $XAUTHORITY add $DISPLAY . $(hexdump -n16 -e '16/1 "%02x"' /dev/urandom)
+    eval $xcmd -auth $XAUTHORITY -query "$xdmcp" &
+else
+    eval xinit -- $xcmd &
+fi
 
-$dummydir/../src/x11spice --password=$password --allow-control &
+# The child of eval will be our Xinit or Xorg session.
+#  eval was used to enable spaces in directory paths to work as expected.
+xpid=`ps -o pid= --ppid $!`
+
+# Wait for Xorg to be usable
+let t=0
+while [ $t -lt 300 ] ; do
+    sleep 0.1
+    t=$((t+1))
+    xdpyinfo >/dev/null 2>&1
+    if [ $? -eq 0 ] ; then
+        break
+    fi
+
+    ps $xpid >/dev/null 2>&1
+    if [ $? -ne 0 ] ; then
+        echo "X server exited before we could connect"
+        exit 1
+    fi
+done
+
+if [ $t -ge 300 ] ; then
+    echo "We did not successfully start the X server"
+    kill $xpid
+    exit 1
+fi
+
+# We have a working X server, now let's start x11spice
+"$x11spice" $args &
 spicepid=$!
 
 echo Xorg server started as pid $xpid
 echo Spice server started as pid $spicepid
-echo You should be able to connect with a spice client now to port 5900,
-echo  using a password of $password
+if [ -n "$password" ] ; then
+    echo You should be able to connect with a spice client now to port 5900,
+    echo  using a password of $password
+fi
 
 wait $spicepid
 
+if [ -n "$xdmcp" ] ; then
+    rm -f $XAUTHORITY
+fi
+
 kill $xpid