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Diffstat (limited to 'scripts/gen-hostnqn.sh')
| -rw-r--r-- | scripts/gen-hostnqn.sh | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/scripts/gen-hostnqn.sh b/scripts/gen-hostnqn.sh new file mode 100644 index 0000000..d8783cf --- /dev/null +++ b/scripts/gen-hostnqn.sh @@ -0,0 +1,42 @@ +#!/bin/bash + +LC_ALL=C + +UUID=$(dmidecode -s system-uuid | tr -d '[:space:]') + +if [ -z "$UUID" ] ; then + >&2 echo "No UUID found, can't determine hostnqn." + exit 1 +fi + +# convert UUID to lower-case only: +UUID=$(echo $UUID | tr '[:upper:]' '[:lower:]') + +# check UUID format, e.g.: 4c4c4544-0156-4a10-8134-b7d04f383232, so: 8-4-4-4-12 +if ! [[ $UUID =~ ^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$ ]] ; then + >&2 echo "UUID has invalid format." + >&2 echo "Invalid UUID: ${UUID}" + exit 2 +fi + +# HEURISTIC: +# (1) if any one given character occurs more than 50% of the time, it is likely +# that the UUID is fake. +# (2) if the first or the last group consists of mostly the same character, it +# is likely that the UUID is fake. +FIRST_GROUP="$(echo $UUID | cut -d'-' -f1)" +LAST_GROUP="$(echo $UUID | cut -d'-' -f5)" +for i in {{0..9},{a..f}} ; do + COUNT_TOTAL="${UUID//[^$i]}" + COUNT_FIRST="${FIRST_GROUP//[^$i]}" + COUNT_LAST="${LAST_GROUP//[^$i]}" + if [ ${#COUNT_TOTAL} -ge 16 ] || [ ${#COUNT_FIRST} -ge 7 ] || [ ${#COUNT_LAST} -ge 11 ] ; then + >&2 echo "UUID is too repetitive. This may be a false alert." + >&2 echo "Repetitive UUID: ${UUID}" + exit 3 + fi +done + +HOSTNQN="nqn.2014-08.org.nvmexpress:uuid:${UUID}" + +echo $HOSTNQN |