Update the iscsi-gen-initiatorname script: harden and generalize

The iscsi-gen-initiatorname script seems only to be used by
the SUSE distrubution, so it has never been very "general". This
update makes the script more resiliant, with better error
messages if a problem occurs, as well as more generic, allowing
the caller to set the "base IQN" value, though the default
contains to be the same.

Changes:
- Added use of getopts to parse options
- Added a "-h" option for help
- Added an option to supply base IQN
- Added better checking of options and params
- Added comments to the script itself
- Now check to see if iname file can be written to
  (handling read-only mounts better)
- Fixed initiator name listed in file (it was wrong)
- Removed use of printf(1)
- Fixed iBFT initiator name setting in general
- Now set iname file mode to 0600 even when it comes from
  iBFT
- Cleaned up the script to use variables instead of repeating
  file pathnames or other values

1 files changed, 50 insertions, 22 deletions

diff --git a/utils/iscsi-gen-initiatorname b/utils/iscsi-gen-initiatorname
index 3e30465..a375968 100755
--- a/utils/iscsi-gen-initiatorname
+++ b/utils/iscsi-gen-initiatorname
@@ -8,23 +8,47 @@
 # This script is licensed under the GPL.
 #
 
-if [ "$1" ] ; then
-    if [ "$1" = "-f" ] ; then
-	FORCE=1
-    else
-	echo "Invalid option $1"
-	echo "Usage: $0 [-f]"
-	exit 1
-    fi
+NAME="$0"
+INAME_FILE="/etc/iscsi/initiatorname.iscsi"
+IQN_BASE="iqn.1996-04.de.suse:01"
+
+usage_and_exit()
+{
+    xit_val=$1
+
+    echo "Usage: $NAME [OPTIONS] -- generate an iSCSI initiatorname"
+    echo "Where OPTIONS are from:"
+    echo "   -h          print usage and exit"
+    echo "   -f          overwrite existing initiator name, if any"
+    echo "   -b IQN-BASE use IQN-BASE for the IQN generated (default $IQN_BASE)"
+    exit $xit_val
+}
+
+while getopts "hfb:" o ; do
+    case "${o}" in
+	h) usage_and_exit 0 ;;
+	f) FORCE=1 ;;
+	b) IQN_BASE=${OPTARG} ;;
+	?) usage_and_exit 1 ;;
+    esac
+done
+shift $(($OPTIND-1))
+
+if [ "$#" -gt 0 ] ; then
+    echo "Invalid argument(s): $*"
+    usage_and_exit
 fi
 
+# use the iBFT initiator name, if present
 if [ -d /sys/firmware/ibft/initiator ] ; then
     read iSCSI_INITIATOR_NAME < /sys/firmware/ibft/initiator/initiator-name
 fi
 
-if [ -f /etc/iscsi/initiatorname.iscsi -a -z "$FORCE" ] ; then
+# if we have an iBFT initiator name and an initiator name
+# file, they had better match, unless "force" is set
+if [ -f $INAME_FILE -a -z "$FORCE" ] ; then
     if [ "$iSCSI_INITIATOR_NAME" ] ; then
-	eval $(cat /etc/iscsi/initiatorname.iscsi | sed -e '/^#/d')
+	eval $(cat $INAME_FILE | sed -e '/^#/d')
 	if [ "$iSCSI_INITIATOR_NAME" != "$InitiatorName" ] ; then
 	    echo "iSCSI Initiatorname from iBFT is different from the current setting."
 	    echo "Please call '@SBINDIR@/iscsi-gen-initiatorname -f' to update the iSCSI Initiatorname."
@@ -33,10 +57,12 @@ if [ -f /etc/iscsi/initiatorname.iscsi -a -z "$FORCE" ] ; then
     fi
 fi
 
+# if we have an initiator name from iBFT or from
+# an existing initiator name file, use it
 if [ "$iSCSI_INITIATOR_NAME" ] ; then
-    cat << EOF >> /etc/iscsi/initiatorname.iscsi
-##
-## /etc/iscsi/iscsi.initiatorname
+    echo "##" > $INAME_FILE || exit 1
+    echo "## $INAME_FILE" >> $INAME_FILE
+    cat << EOF >> $INAME_FILE
 ##
 ## iSCSI Initiatorname taken from iBFT BIOS tables.
 ##
@@ -48,14 +74,16 @@ if [ "$iSCSI_INITIATOR_NAME" ] ; then
 ## @SBINDIR@/iscsi-gen-initiatorname -f
 ## to recreate an updated version of this file.
 ##
-InitiatorName=$iSCSI_INITIATOR_NAME
 EOF
+    echo "InitiatorName=$iSCSI_INITIATOR_NAME" >> $INAME_FILE
+    chmod 0600 $INAME_FILE
 fi
 
-if [ ! -f /etc/iscsi/initiatorname.iscsi ] ; then
-    cat << EOF >> /etc/iscsi/initiatorname.iscsi
-##
-## /etc/iscsi/iscsi.initiatorname
+# if we still do not have an initiator name, create one
+if [ ! -f $INAME_FILE ] ; then
+    echo "##" > $INAME_FILE || exit 1
+    echo "## $INAME_FILE" >> $INAME_FILE
+    cat << EOF >> $INAME_FILE
 ##
 ## Default iSCSI Initiatorname.
 ##
@@ -65,9 +93,9 @@ if [ ! -f /etc/iscsi/initiatorname.iscsi ] ; then
 ## may reject this initiator.  The InitiatorName must be unique
 ## for each iSCSI initiator.  Do NOT duplicate iSCSI InitiatorNames.
 EOF
-	ISSUEDATE="1996-04"
-	INAME=$(@SBINDIR@/iscsi-iname -p iqn.$ISSUEDATE.de.suse:01)
-	printf "InitiatorName=$INAME\n"  >>/etc/iscsi/initiatorname.iscsi
-	chmod 0600 /etc/iscsi/initiatorname.iscsi
+    # create a unique initiator name using iscsi-iname
+    INAME=$(@SBINDIR@/iscsi-iname -p "$IQN_BASE")
+    echo "InitiatorName=$INAME" >> $INAME_FILE
+    chmod 0600 $INAME_FILE
 fi