tools: Provide a script to recover fubar'ed XATTRs setup

Our code is not bug free. The refcounting I introduced will
almost certainly not work in some use cases. Provide a script
that will remove all the XATTRs set by libvirt so that it can
start cleanly.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

tools/Makefile.am

@@ -75,6 +75,7 @@ EXTRA_DIST = \
 	virt-login-shell.conf \
 	virsh-edit.c \
 	bash-completion/vsh \
+	libvirt_recover_xattrs.sh \
 	$(PODFILES) \
 	$(MANINFILES) \
 	$(NULL)

tools/libvirt_recover_xattrs.sh

@@ -0,0 +1,96 @@
+#!/bin/bash
+
+function die {
+    echo $@ >&2
+    exit 1
+}
+
+function show_help {
+    cat << EOF
+Usage: ${0##*/} -[hqn] [PATH]
+
+Clear out any XATTRs set by libvirt on all files that have them.
+The idea is to reset refcounting, should it break.
+
+  -h    display this help and exit
+  -q    quiet (don't print which files are being fixed)
+  -n    dry run; don't remove any XATTR just report the file name
+
+PATH can be specified to refine search to only to given path
+instead of whole root ('/'), which is the default.
+EOF
+}
+
+QUIET=0
+DRY_RUN=0
+P="/"
+
+# So far only qemu and lxc drivers use security driver.
+URI=("qemu:///system"
+     "qemu:///session"
+     "lxc:///system")
+
+LIBVIRT_XATTR_PREFIX="trusted.libvirt.security"
+
+if [ `whoami` != "root" ]; then
+    die "Must be run as root"
+fi
+
+while getopts hqn opt; do
+    case $opt in
+        h)
+            show_help
+            exit 0
+            ;;
+        q)
+            QUIET=1
+            ;;
+        n)
+            DRY_RUN=1
+            ;;
+        *)
+            show_help >&2
+            exit 1
+            ;;
+    esac
+done
+
+shift $((OPTIND - 1))
+if [ $# -gt 0 ]; then
+    P=$1
+fi
+
+if [ ${DRY_RUN} -eq 0 ]; then
+    for u in ${URI[*]} ; do
+        if [ -n "`virsh -q -c $u list 2>/dev/null`" ]; then
+            die "There are still some domains running for $u"
+        fi
+    done
+fi
+
+
+# On Linux we use 'trusted' namespace, on FreeBSD we use 'system'
+# as there is no 'trusted'.
+XATTRS=("trusted.libvirt.security.dac"
+        "trusted.libvirt.security.ref_dac"
+        "trusted.libvirt.security.selinux"
+        "trusted.libvirt.security.ref_selinux",
+        "system.libvirt.security.dac"
+        "system.libvirt.security.ref_dac"
+        "system.libvirt.security.selinux"
+        "system.libvirt.security.ref_selinux")
+
+for i in $(getfattr -R -d -m ${LIBVIRT_XATTR_PREFIX} --absolute-names ${P} 2>/dev/null | grep "^# file:" | cut -d':' -f 2); do
+    if [ ${DRY_RUN} -ne 0 ]; then
+        echo $i
+        getfattr -d -m ${LIBVIRT_XATTR_PREFIX} $i
+        continue
+    fi
+
+    if [ ${QUIET} -eq 0 ]; then
+        echo "Fixing $i";
+    fi
+    for x in ${XATTRS[*]}; do
+        setfattr -x $x $i
+    done
+done