[Qemu-devel] [PATCH] qmp: allow setting properties to empty string in qmp-shell

[Qemu-devel] [PATCH] qmp: allow setting properties to empty string in qmp-shell

[Daniel P. Berrange]

The qmp-shell property parser currently rejects attempts to
set string properties to the empty string eg

  (QEMU) migrate-set-parameters  tls-hostname=
  Error while parsing command line: Expected a key=value pair, got 'tls-hostname='
command format: <command-name>  [arg-name1=arg1] ... [arg-nameN=argN]

This is caused by checking the wrong condition after splitting
the parameter on '='. The "partition" method will return "" for
the separator field, if the seperator was not present, so that
is the correct thing to check for malformed syntax.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
---
 scripts/qmp/qmp-shell | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/scripts/qmp/qmp-shell b/scripts/qmp/qmp-shell
index 0373b24..eccb88a 100755
--- a/scripts/qmp/qmp-shell
+++ b/scripts/qmp/qmp-shell
@@ -166,8 +166,8 @@ class QMPShell(qmp.QEMUMonitorProtocol):
 
     def __cli_expr(self, tokens, parent):
         for arg in tokens:
-            (key, _, val) = arg.partition('=')
-            if not val:
+            (key, sep, val) = arg.partition('=')
+            if sep != '=':
                 raise QMPShellError("Expected a key=value pair, got '%s'" % arg)
 
             value = self.__parse_value(val)
-- 
2.9.3

Re: [Qemu-devel] [PATCH] qmp: allow setting properties to empty string in qmp-shell

[Eric Blake]

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On 03/02/2017 06:24 AM, Daniel P. Berrange wrote:
> The qmp-shell property parser currently rejects attempts to
> set string properties to the empty string eg
> 
>   (QEMU) migrate-set-parameters  tls-hostname=
>   Error while parsing command line: Expected a key=value pair, got 'tls-hostname='
> command format: <command-name>  [arg-name1=arg1] ... [arg-nameN=argN]
> 
> This is caused by checking the wrong condition after splitting
> the parameter on '='. The "partition" method will return "" for
> the separator field, if the seperator was not present, so that
> is the correct thing to check for malformed syntax.
> 
> Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
> ---
>  scripts/qmp/qmp-shell | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Reviewed-by: Eric Blake <eblake@redhat.com>

Probably worth having in 2.9, since we are having the parallel
discussion about permitting an empty string as a way to clear out TLS in
migration parameters.

> 
> diff --git a/scripts/qmp/qmp-shell b/scripts/qmp/qmp-shell
> index 0373b24..eccb88a 100755
> --- a/scripts/qmp/qmp-shell
> +++ b/scripts/qmp/qmp-shell
> @@ -166,8 +166,8 @@ class QMPShell(qmp.QEMUMonitorProtocol):
>  
>      def __cli_expr(self, tokens, parent):
>          for arg in tokens:
> -            (key, _, val) = arg.partition('=')
> -            if not val:
> +            (key, sep, val) = arg.partition('=')
> +            if sep != '=':
>                  raise QMPShellError("Expected a key=value pair, got '%s'" % arg)
>  
>              value = self.__parse_value(val)
> 

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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Re: [Qemu-devel] [PATCH] qmp: allow setting properties to empty string in qmp-shell

[John Snow]

On 03/02/2017 07:24 AM, Daniel P. Berrange wrote:
> The qmp-shell property parser currently rejects attempts to
> set string properties to the empty string eg
> 
>   (QEMU) migrate-set-parameters  tls-hostname=
>   Error while parsing command line: Expected a key=value pair, got 'tls-hostname='
> command format: <command-name>  [arg-name1=arg1] ... [arg-nameN=argN]
> 
> This is caused by checking the wrong condition after splitting
> the parameter on '='. The "partition" method will return "" for
> the separator field, if the seperator was not present, so that
> is the correct thing to check for malformed syntax.
> 

Ah, good point.

> Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

Reviewed-by: John Snow <jsnow@redhat.com>

> ---
>  scripts/qmp/qmp-shell | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/scripts/qmp/qmp-shell b/scripts/qmp/qmp-shell
> index 0373b24..eccb88a 100755
> --- a/scripts/qmp/qmp-shell
> +++ b/scripts/qmp/qmp-shell
> @@ -166,8 +166,8 @@ class QMPShell(qmp.QEMUMonitorProtocol):
>  
>      def __cli_expr(self, tokens, parent):
>          for arg in tokens:
> -            (key, _, val) = arg.partition('=')
> -            if not val:
> +            (key, sep, val) = arg.partition('=')
> +            if sep != '=':
>                  raise QMPShellError("Expected a key=value pair, got '%s'" % arg)
>  
>              value = self.__parse_value(val)
> 

Re: [Qemu-devel] [PATCH] qmp: allow setting properties to empty string in qmp-shell

[Markus Armbruster]

"Daniel P. Berrange" <berrange@redhat.com> writes:

> The qmp-shell property parser currently rejects attempts to
> set string properties to the empty string eg
>
>   (QEMU) migrate-set-parameters  tls-hostname=
>   Error while parsing command line: Expected a key=value pair, got 'tls-hostname='
> command format: <command-name>  [arg-name1=arg1] ... [arg-nameN=argN]
>
> This is caused by checking the wrong condition after splitting
> the parameter on '='. The "partition" method will return "" for
> the separator field, if the seperator was not present, so that
> is the correct thing to check for malformed syntax.
>
> Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

I'll take this through my tree, unless qemu-trivial beats me to the
punch.  Thanks!