[meta-arm] arm-autonomy/xenguest-manager: Private xenguest-manager functions

Submitted by Nathan Dunne on Nov. 23, 2020, 1:31 p.m. | Patch ID: 178095

Details

Message ID 20201123133125.24226-1-Nathan.Dunne@arm.com
State New
Headers show

Commit Message

Nathan Dunne Nov. 23, 2020, 1:31 p.m. 
Ensure that init scripts sourced on guest start cannot execute functions
from the parent script. This is done using a check for the BASH_SUBSHELL
variable to see the depth of execution.

An error will be thrown if any init script attempts to execute a
function from xenguest-manager

Issue-Id: SCM-1623
Signed-off-by: Nathan Dunne <Nathan.Dunne@arm.com>

Change-Id: I87fee51d03a64d99728a7eca1ca789ec7293096b
---
 .../xenguest/files/xenguest-manager           | 44 +++++++++++++++++--
 1 file changed, 41 insertions(+), 3 deletions(-)

-- 
2.17.1
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diff --git a/meta-arm-autonomy/recipes-extended/xenguest/files/xenguest-manager b/meta-arm-autonomy/recipes-extended/xenguest/files/xenguest-manager
index edd9a89..33ec40f 100755
--- a/meta-arm-autonomy/recipes-extended/xenguest/files/xenguest-manager
+++ b/meta-arm-autonomy/recipes-extended/xenguest/files/xenguest-manager
@@ -54,7 +54,24 @@  with ACTION being one of:
 EOF
 }
 
+# Ensure init scripts in subshells do not call private functions
+function check_private()
+{
+
+    # Return:
+    # 0 - success
+    # 1 - failure
+
+    if [ $BASH_SUBSHELL -ne 0 ]; then
+        echo "Attempted to execute private function ${FUNCNAME[1]} in subshell!"
+        exit 1
+    fi
+}
+
 is_integer() {
+
+    check_private
+
     if ! [[ "${1}" =~ ^[0-9]+$ ]]; then
         >&2 echo "error: invalid number '${1}'"; exit 1
     fi
@@ -62,6 +79,9 @@  is_integer() {
 
 # check size and convert it to MB, e.g '1[G]' => '1000M'
 check_size() {
+
+    check_private
+
     local disksize="${1}"
 
     [ -n "${disksize}" ] || disksize="invalid"
@@ -101,6 +121,8 @@  function xenguest_volume_init()
     # 0 - success
     # 1 - failure
 
+    check_private
+
     if [ -z "${XENGUEST_VOLUME_DEVICE:-}" -o \
         ! -b ${XENGUEST_VOLUME_DEVICE:-} ]; then
         echo "${PREF} Invalid volume device in configuration: ${XENGUEST_VOLUME_DEVICE:-}"
@@ -154,6 +176,8 @@  function xenguest_volume_init()
 # Detach a disk we attached to xen
 function xenguest_detach_disk()
 {
+    check_private
+
     echo "xl block-detach 0 \$\(xl block-list 0 | " \
         "grep \"domain/0\" | awk '{print \$1}'\)" \
             >> ${LOGFILE} 2>&1
@@ -177,6 +201,8 @@  function xenguest_disk_init()
     # 1 - failed at guest disk preparation
     # 2 - failed at guest disk creation
 
+    check_private
+
     guestname="$1"
     guestfile="$2"
     devname="/dev/${XENGUEST_VOLUME_NAME}/${guestname}"
@@ -454,6 +480,7 @@  function xenguest_disk_init()
 
 function xenguest_guest_create()
 {
+    check_private
     guestfile="$1"
     guestname="$2"
 
@@ -502,6 +529,8 @@  function xenguest_guest_create()
 
 function xenguest_guest_remove()
 {
+    check_private
+
     guestname="$1"
     devname="/dev/${XENGUEST_VOLUME_NAME}/${guestname}"
 
@@ -526,6 +555,8 @@  function xenguest_guest_remove()
 
 function xenguest_guest_start()
 {
+    check_private
+
     guestname="${1}"
     guestdir=${XENGUEST_CONF_BASE}/guests/${guestname}
 
@@ -560,7 +591,8 @@  function xenguest_guest_start()
                 rm -f ${guestcfgfile}
                 popd > /dev/null 2>&1
                 echo "Error in init script $f" >> ${LOGFILE} 2>&1
-                echo "${PREF} Error during pre init script of ${guestname}"
+                echo "${PREF} Error during pre init script $(basename $f) of ${guestname}"
+                echo "${PREF} Check the log: ${LOGFILE} for more information"
                 exit 1
             fi
         else
@@ -589,7 +621,8 @@  function xenguest_guest_start()
                 xl destroy ${guestname} >> ${LOGFILE} 2>&1
                 popd > /dev/null 2>&1
                 echo "Error in init script $f" >> ${LOGFILE} 2>&1
-                echo "${PREF} Error during init script of ${guestname}"
+                echo "${PREF} Error during init script $(basename $f) of ${guestname}"
+                echo "${PREF} Check the log: ${LOGFILE} for more information"
                 exit 1
             fi
         else
@@ -618,7 +651,8 @@  function xenguest_guest_start()
                 xl destroy ${guestname} >> ${LOGFILE} 2>&1
                 popd > /dev/null 2>&1
                 echo "Error in init script $f" >> ${LOGFILE} 2>&1
-                echo "${PREF} Error during post init script of ${guestname}"
+                echo "${PREF} Error during post init script $(basename $f) of ${guestname}"
+                echo "${PREF} Check the log: ${LOGFILE} for more information"
                 exit 1
             fi
         else
@@ -632,6 +666,8 @@  function xenguest_guest_start()
 
 function xenguest_guest_stop()
 {
+    check_private
+
     guestname="${1}"
     echo "xl shutdown ${guestname}" >> ${LOGFILE} 2>&1
     xl shutdown ${guestname} >> ${LOGFILE} 2>&1
@@ -643,6 +679,8 @@  function xenguest_guest_stop()
 
 function check_guest_arg()
 {
+    check_private
+
     cmd="${1}"
     guestname="${2:-}"
     if [ -z "${guestname:-}" ]; then

Comments

Jon Mason Nov. 23, 2020, 2:26 p.m. 
On Mon, Nov 23, 2020 at 01:31:25PM +0000, Nathan Dunne wrote:
> Ensure that init scripts sourced on guest start cannot execute functions

> from the parent script. This is done using a check for the BASH_SUBSHELL

> variable to see the depth of execution.

> 

> An error will be thrown if any init script attempts to execute a

> function from xenguest-manager

> 

> Issue-Id: SCM-1623

> Signed-off-by: Nathan Dunne <Nathan.Dunne@arm.com>

> Change-Id: I87fee51d03a64d99728a7eca1ca789ec7293096b


Pushed to master.

Thanks,
Jon

> ---

>  .../xenguest/files/xenguest-manager           | 44 +++++++++++++++++--

>  1 file changed, 41 insertions(+), 3 deletions(-)

> 

> diff --git a/meta-arm-autonomy/recipes-extended/xenguest/files/xenguest-manager b/meta-arm-autonomy/recipes-extended/xenguest/files/xenguest-manager

> index edd9a89..33ec40f 100755

> --- a/meta-arm-autonomy/recipes-extended/xenguest/files/xenguest-manager

> +++ b/meta-arm-autonomy/recipes-extended/xenguest/files/xenguest-manager

> @@ -54,7 +54,24 @@ with ACTION being one of:

>  EOF

>  }

>  

> +# Ensure init scripts in subshells do not call private functions

> +function check_private()

> +{

> +

> +    # Return:

> +    # 0 - success

> +    # 1 - failure

> +

> +    if [ $BASH_SUBSHELL -ne 0 ]; then

> +        echo "Attempted to execute private function ${FUNCNAME[1]} in subshell!"

> +        exit 1

> +    fi

> +}

> +

>  is_integer() {

> +

> +    check_private

> +

>      if ! [[ "${1}" =~ ^[0-9]+$ ]]; then

>          >&2 echo "error: invalid number '${1}'"; exit 1

>      fi

> @@ -62,6 +79,9 @@ is_integer() {

>  

>  # check size and convert it to MB, e.g '1[G]' => '1000M'

>  check_size() {

> +

> +    check_private

> +

>      local disksize="${1}"

>  

>      [ -n "${disksize}" ] || disksize="invalid"

> @@ -101,6 +121,8 @@ function xenguest_volume_init()

>      # 0 - success

>      # 1 - failure

>  

> +    check_private

> +

>      if [ -z "${XENGUEST_VOLUME_DEVICE:-}" -o \

>          ! -b ${XENGUEST_VOLUME_DEVICE:-} ]; then

>          echo "${PREF} Invalid volume device in configuration: ${XENGUEST_VOLUME_DEVICE:-}"

> @@ -154,6 +176,8 @@ function xenguest_volume_init()

>  # Detach a disk we attached to xen

>  function xenguest_detach_disk()

>  {

> +    check_private

> +

>      echo "xl block-detach 0 \$\(xl block-list 0 | " \

>          "grep \"domain/0\" | awk '{print \$1}'\)" \

>              >> ${LOGFILE} 2>&1

> @@ -177,6 +201,8 @@ function xenguest_disk_init()

>      # 1 - failed at guest disk preparation

>      # 2 - failed at guest disk creation

>  

> +    check_private

> +

>      guestname="$1"

>      guestfile="$2"

>      devname="/dev/${XENGUEST_VOLUME_NAME}/${guestname}"

> @@ -454,6 +480,7 @@ function xenguest_disk_init()

>  

>  function xenguest_guest_create()

>  {

> +    check_private

>      guestfile="$1"

>      guestname="$2"

>  

> @@ -502,6 +529,8 @@ function xenguest_guest_create()

>  

>  function xenguest_guest_remove()

>  {

> +    check_private

> +

>      guestname="$1"

>      devname="/dev/${XENGUEST_VOLUME_NAME}/${guestname}"

>  

> @@ -526,6 +555,8 @@ function xenguest_guest_remove()

>  

>  function xenguest_guest_start()

>  {

> +    check_private

> +

>      guestname="${1}"

>      guestdir=${XENGUEST_CONF_BASE}/guests/${guestname}

>  

> @@ -560,7 +591,8 @@ function xenguest_guest_start()

>                  rm -f ${guestcfgfile}

>                  popd > /dev/null 2>&1

>                  echo "Error in init script $f" >> ${LOGFILE} 2>&1

> -                echo "${PREF} Error during pre init script of ${guestname}"

> +                echo "${PREF} Error during pre init script $(basename $f) of ${guestname}"

> +                echo "${PREF} Check the log: ${LOGFILE} for more information"

>                  exit 1

>              fi

>          else

> @@ -589,7 +621,8 @@ function xenguest_guest_start()

>                  xl destroy ${guestname} >> ${LOGFILE} 2>&1

>                  popd > /dev/null 2>&1

>                  echo "Error in init script $f" >> ${LOGFILE} 2>&1

> -                echo "${PREF} Error during init script of ${guestname}"

> +                echo "${PREF} Error during init script $(basename $f) of ${guestname}"

> +                echo "${PREF} Check the log: ${LOGFILE} for more information"

>                  exit 1

>              fi

>          else

> @@ -618,7 +651,8 @@ function xenguest_guest_start()

>                  xl destroy ${guestname} >> ${LOGFILE} 2>&1

>                  popd > /dev/null 2>&1

>                  echo "Error in init script $f" >> ${LOGFILE} 2>&1

> -                echo "${PREF} Error during post init script of ${guestname}"

> +                echo "${PREF} Error during post init script $(basename $f) of ${guestname}"

> +                echo "${PREF} Check the log: ${LOGFILE} for more information"

>                  exit 1

>              fi

>          else

> @@ -632,6 +666,8 @@ function xenguest_guest_start()

>  

>  function xenguest_guest_stop()

>  {

> +    check_private

> +

>      guestname="${1}"

>      echo "xl shutdown ${guestname}" >> ${LOGFILE} 2>&1

>      xl shutdown ${guestname} >> ${LOGFILE} 2>&1

> @@ -643,6 +679,8 @@ function xenguest_guest_stop()

>  

>  function check_guest_arg()

>  {

> +    check_private

> +

>      cmd="${1}"

>      guestname="${2:-}"

>      if [ -z "${guestname:-}" ]; then

> -- 

> 2.17.1

> 


> 

> 

>
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