From bbefbe9273409e081ebb20ef1dc3e3e8be6bfb9f Mon Sep 17 00:00:00 2001
From: Muminul Islam <muislam@microsoft.com>
Date: Wed, 18 Aug 2021 15:32:09 -0700
Subject: [PATCH] tools: Add a script to check image compatibility

This script checks if an image is compatible with Cloud Hypervisor.
At first, it detects the image type(raw or qcow2),
partition type whether it is DOS or GPT.
Then it mounts the image and checks if VIRTIO Configs
are enabled in the kernel config. In the end, it provides
a message about the compatibility of the image.

Signed-off-by: Muminul Islam <muislam@microsoft.com>
---
 scripts/check-image-compatability.sh | 215 +++++++++++++++++++++++++++
 1 file changed, 215 insertions(+)
 create mode 100755 scripts/check-image-compatability.sh

diff --git a/scripts/check-image-compatability.sh b/scripts/check-image-compatability.sh
new file mode 100755
index 000000000..22063c827
--- /dev/null
+++ b/scripts/check-image-compatability.sh
@@ -0,0 +1,215 @@
+#!/bin/bash
+: '
+    This script checks if an image is compatible with Cloud Hypervisor.
+    At first, it detects the image type(raw or qcow2),
+    partition type whether it is DOS or GPT.
+    Then it mounts the image and checks if VIRTIO Configs
+    are enabled in the kernel config. In the end, it provides
+    a message about the compatibility of the image.
+'
+
+
+
+usage="$(basename "$0") [-h] -f -w -- program to check Cloud Hypervisor compatible image
+
+where:
+    -h  show this help text
+    -f  image file location
+    -w  directory to be used for temporary files"
+
+function check_command {
+    if ! command -v  $1 &> /dev/null
+        then
+            echo "Command $1 could not be found"
+        exit 1
+    fi
+};
+
+function check_if_root {
+    if [ "$EUID" -ne 0 ]; then
+        echo "Please run as root"
+        exit 1
+    fi
+
+};
+
+check_if_root
+working_dir=""
+while getopts ':hf:w:' option; do
+    case "$option" in
+        h) echo "$usage"
+            exit
+            ;;
+        f) file_name=$OPTARG
+            ;;
+        w) working_dir=$OPTARG
+            ;;
+        :) printf "missing argument for -%s\n" "$OPTARG" >&2
+            echo "$usage" >&2
+            exit 1
+            ;;
+        \?) printf "illegal option: -%s\n" "$OPTARG" >&2
+            echo "$usage" >&2
+            exit 1
+            ;;
+    esac
+done
+
+shift $((OPTIND - 1))
+
+if [ -z "${file_name}" ]; then
+    echo "You must provide the image file name"
+	exit 1
+fi
+if [[ ! -f ${file_name} ]]; then
+    echo "File ${file_name} does not exist"
+    exit 1
+fi
+
+file_abs_path=`readlink -m ${file_name}`
+if [[ "${working_dir}" != "" && ! -d "${working_dir}" ]]; then
+    echo "Directory ${working_dir} does not exist"
+    exit 1
+elif [[ "${working_dir}" == "" ]]; then
+    working_dir=`mktemp -d`
+    tmp_created=1
+else
+    working_dir=`readlink -m ${working_dir}`
+fi
+
+#get file extension and image type
+extension="${file_name##*.}"
+filename="${file_name%.*}"
+dest_file=${working_dir}/${filename}.raw
+image_type=$(qemu-img info ${file_abs_path} | grep 'file format:' | awk '{ print $3 }')
+echo "Image type detected as ${image_type}"
+
+
+if [[ "${image_type}" == "raw" ]]; then
+	dest_file=${file_abs_path}
+elif [[ "$image_type" == "qcow2" ]]; then
+    if lsmod | grep "nbd" &> /dev/null ; then
+        echo "Module nbd is loaded!"
+    else
+        echo "Module nbd is not loaded. Trying to load the module"
+        modprobe nbd max_part=8
+        if [ $? != 0 ]; then
+            echo "failed to load nbd module. Exiting"
+            exit 1
+        fi
+    fi
+    check_command qemu-img
+    dest_file=/dev/nbd0
+    qemu-nbd --connect=${dest_file} ${file_abs_path} --read-only
+fi
+
+check_command blkid
+#get part info
+part_type=$(blkid -o value -s PTTYPE ${dest_file})
+
+check_command partx
+nr_partitions=`partx -g ${dest_file}  | wc -l`
+
+check_command fdisk
+out=`fdisk -l  ${dest_file} --bytes | grep -i -A ${nr_partitions} 'Device' | tail -n +2`
+
+IFS='
+'
+i=0
+declare -A liness
+for x in $out ; do
+	lines[$i]=$x
+	i=$((i+1))
+done
+
+declare -A partitions
+IFS=' '
+i=0
+ROWS=${#lines[@]}
+
+for line in "${lines[@]}";
+do
+	j=0
+	read -a str_arr <<< "$line"
+	for val in "${str_arr[@]}";
+	do
+		if [[ "$val" != "*" ]]; then
+			partitions[$i,$j]=$val
+			j=$((j+1))
+		fi
+	done
+	i=$((i+1))
+done
+
+COLUMNS=$j
+COUNT=${#partitions[@]}
+START_ADDRESS_INDEX=1
+FILE_SYS_INDEX2=$((COLUMNS-1))
+FILE_SYS_INDEX1=$((COLUMNS-2))
+DEVICE_INDEX=0
+# Here we have all the partition info now lets mount and analyze the contents
+for ((i=0;i<ROWS;i++)) do
+	if [[ "$part_type" == "gpt" && "${partitions[$i,${FILE_SYS_INDEX1}]}" == "Linux" && "${partitions[$i,${FILE_SYS_INDEX2}]}" == "filesystem" ]]; then
+        echo "The image has GPT partitions"
+        MOUNT_ROW=$i
+		break
+	elif [[ "$part_type" == "dos" && "${partitions[$i,${FILE_SYS_INDEX1}]}" == "Linux" && "${partitions[$i,${FILE_SYS_INDEX2}]}" == "" ]]; then
+        echo "The image has DOS partitions"
+        MOUNT_ROW=$i
+        break
+	fi
+done
+
+start_address=${partitions[${MOUNT_ROW},${START_ADDRESS_INDEX}]}
+offset=$((start_address*512))
+
+MOUNT_DIR=/mnt/clh-img-check/
+rm -rf ${MOUNT_DIR}
+mkdir ${MOUNT_DIR}
+if [[ "${image_type}" == "raw" ]]; then
+    mount -o ro,loop,offset=$offset ${dest_file} ${MOUNT_DIR}
+elif [[ "${image_type}" == "qcow2" ]]; then
+    mount -o ro ${partitions[${MOUNT_ROW},${DEVICE_INDEX}]} ${MOUNT_DIR}
+fi
+
+CONFIG_DIR=${MOUNT_DIR}boot/
+if [[ "$part_type" == "dos" ]]; then
+	CONFIG_DIR=${MOUNT_DIR}
+fi
+
+#check VIRTIO
+HAS_VIRTIO=1
+for conf_file in ${CONFIG_DIR}config*; do
+    out=`grep -E "CONFIG_VIRTIO=y|CONFIG_VIRTIO_BLK=y|CONFIG_VIRTIO_BLK=m" ${conf_file} | wc -l`
+    if [[ "$out" != "2" ]]; then
+	    echo "VIRTIO not found"
+		HAS_VIRTIO=0
+	fi
+done
+
+#clean up
+umount ${MOUNT_DIR}
+
+if [[ "${tmp_created}" == "1" ]]; then
+    rm -rf ${working_dir}
+fi
+
+if [[ "${image_type}" == "qcow2" ]];then
+    qemu-nbd --disconnect ${dest_file} > /dev/null
+fi
+
+result=""
+if [[ "${part_type}" == "dos" ]]; then
+	result="dos mode not supported"
+fi
+if [[ "${HAS_VIRTIO}" == "0" ]]; then
+	if [[ "$result" != "" ]]; then
+		result="${result},"
+	fi
+	result="$result VirtIO module not found in the image"
+fi
+if [[ "$result" == "" ]];then
+	echo "No incompatibilities found"
+else
+	echo "$result"
+fi