When security drivers are active but confinement is not enabled,
there is no need to autogenerate <seclabel> elements when starting
a domain def that contains no <seclabel> elements. In fact,
autogenerating the elements can result in needless save/restore and
migration failures when the security driver is not active on the
restore/migration target.

This patch changes the virSecurityManagerGenLabel function in
src/security_manager.c to only autogenerate a <seclabel> element
if none is already defined for the domain *and* default
confinement is enabled. Otherwise the needless <seclabel>
autogeneration is skipped.

Resolves: https://bugzilla.opensuse.org/show_bug.cgi?id=1051017
Signed-off-by: Jim Fehlig <jfehlig@suse.com>
---

V2: Don't autogenerate a seclabel if domain does not contain one
    and confinement is disabled.

 src/security/security_manager.c | 42 +++++++++++++++++++++--------------------
 1 file changed, 22 insertions(+), 20 deletions(-)

diff --git a/src/security/security_manager.c b/src/security/security_manager.c
index 013bbc37e..10515c314 100644
--- a/src/security/security_manager.c
+++ b/src/security/security_manager.c
@@ -650,30 +650,32 @@ virSecurityManagerGenLabel(virSecurityManagerPtr mgr,
     for (i = 0; sec_managers[i]; i++) {
         generated = false;
         seclabel = virDomainDefGetSecurityLabelDef(vm, sec_managers[i]->drv->name);
-        if (!seclabel) {
-            if (!(seclabel = virSecurityLabelDefNew(sec_managers[i]->drv->name)))
-                goto cleanup;
-            generated = seclabel->implicit = true;
-        }
+        if (seclabel) {
+            if (seclabel->type == VIR_DOMAIN_SECLABEL_DEFAULT) {
+                if (virSecurityManagerGetDefaultConfined(sec_managers[i])) {
+                    seclabel->type = VIR_DOMAIN_SECLABEL_DYNAMIC;
+                } else {
+                    seclabel->type = VIR_DOMAIN_SECLABEL_NONE;
+                    seclabel->relabel = false;
+                }
+            }
 
-        if (seclabel->type == VIR_DOMAIN_SECLABEL_DEFAULT) {
+            if (seclabel->type == VIR_DOMAIN_SECLABEL_NONE) {
+                if (virSecurityManagerGetRequireConfined(sec_managers[i])) {
+                    virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                                   _("Unconfined guests are not allowed on this host"));
+                    goto cleanup;
+                }
+            }
+        } else {
+            /* Only generate seclabel if confinement is enabled */
             if (virSecurityManagerGetDefaultConfined(sec_managers[i])) {
+                if (!(seclabel = virSecurityLabelDefNew(sec_managers[i]->drv->name)))
+                    goto cleanup;
+                generated = seclabel->implicit = true;
                 seclabel->type = VIR_DOMAIN_SECLABEL_DYNAMIC;
             } else {
-                seclabel->type = VIR_DOMAIN_SECLABEL_NONE;
-                seclabel->relabel = false;
-            }
-        }
-
-        if (seclabel->type == VIR_DOMAIN_SECLABEL_NONE) {
-            if (virSecurityManagerGetRequireConfined(sec_managers[i])) {
-                virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
-                               _("Unconfined guests are not allowed on this host"));
-                goto cleanup;
-            } else if (vm->nseclabels && generated) {
-                VIR_DEBUG("Skipping auto generated seclabel of type none");
-                virSecurityLabelDefFree(seclabel);
-                seclabel = NULL;
+                VIR_DEBUG("Skipping auto generated seclabel");
                 continue;
             }
         }
-- 
2.13.1

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On Wed, Aug 16, 2017 at 05:54:08PM -0600, Jim Fehlig wrote:
> When security drivers are active but confinement is not enabled,
> there is no need to autogenerate <seclabel> elements when starting
> a domain def that contains no <seclabel> elements. In fact,
> autogenerating the elements can result in needless save/restore and
> migration failures when the security driver is not active on the
> restore/migration target.
>
> This patch changes the virSecurityManagerGenLabel function in
> src/security_manager.c to only autogenerate a <seclabel> element
> if none is already defined for the domain *and* default
> confinement is enabled. Otherwise the needless <seclabel>
> autogeneration is skipped.
>
> Resolves: https://bugzilla.opensuse.org/show_bug.cgi?id=1051017
> Signed-off-by: Jim Fehlig <jfehlig@suse.com>
> ---
>
> V2: Don't autogenerate a seclabel if domain does not contain one
>     and confinement is disabled.
>
>  src/security/security_manager.c | 42 +++++++++++++++++++++--------------------
>  1 file changed, 22 insertions(+), 20 deletions(-)
>
> diff --git a/src/security/security_manager.c b/src/security/security_manager.c
> index 013bbc37e..10515c314 100644
> --- a/src/security/security_manager.c
> +++ b/src/security/security_manager.c
> @@ -650,30 +650,32 @@ virSecurityManagerGenLabel(virSecurityManagerPtr mgr,
>      for (i = 0; sec_managers[i]; i++) {
>          generated = false;
>          seclabel = virDomainDefGetSecurityLabelDef(vm, sec_managers[i]->drv->name);
> -        if (!seclabel) {
> -            if (!(seclabel = virSecurityLabelDefNew(sec_managers[i]->drv->name)))
> -                goto cleanup;
> -            generated = seclabel->implicit = true;
> -        }
> +        if (seclabel) {

Just a tiny nitpick, generally we prefer the 'if' block to be shorter than the
corresponding 'else' block.

> +            if (seclabel->type == VIR_DOMAIN_SECLABEL_DEFAULT) {
> +                if (virSecurityManagerGetDefaultConfined(sec_managers[i])) {
> +                    seclabel->type = VIR_DOMAIN_SECLABEL_DYNAMIC;
> +                } else {
> +                    seclabel->type = VIR_DOMAIN_SECLABEL_NONE;
> +                    seclabel->relabel = false;
> +                }
> +            }
>
> -        if (seclabel->type == VIR_DOMAIN_SECLABEL_DEFAULT) {
> +            if (seclabel->type == VIR_DOMAIN_SECLABEL_NONE) {
> +                if (virSecurityManagerGetRequireConfined(sec_managers[i])) {
> +                    virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> +                                   _("Unconfined guests are not allowed on this host"));
> +                    goto cleanup;
> +                }
> +            }
> +        } else {
> +            /* Only generate seclabel if confinement is enabled */
>              if (virSecurityManagerGetDefaultConfined(sec_managers[i])) {

The same applies to this nested if-else block.

> +                if (!(seclabel = virSecurityLabelDefNew(sec_managers[i]->drv->name)))
> +                    goto cleanup;
> +                generated = seclabel->implicit = true;
>                  seclabel->type = VIR_DOMAIN_SECLABEL_DYNAMIC;
>              } else {
> -                seclabel->type = VIR_DOMAIN_SECLABEL_NONE;
> -                seclabel->relabel = false;
> -            }
> -        }
> -
> -        if (seclabel->type == VIR_DOMAIN_SECLABEL_NONE) {
> -            if (virSecurityManagerGetRequireConfined(sec_managers[i])) {
> -                virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> -                               _("Unconfined guests are not allowed on this host"));
> -                goto cleanup;
> -            } else if (vm->nseclabels && generated) {
> -                VIR_DEBUG("Skipping auto generated seclabel of type none");
> -                virSecurityLabelDefFree(seclabel);
> -                seclabel = NULL;
> +                VIR_DEBUG("Skipping auto generated seclabel");
>                  continue;
>              }
>          }

ACK with the adjustment.

Erik

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On 08/17/2017 02:17 AM, Erik Skultety wrote:
> On Wed, Aug 16, 2017 at 05:54:08PM -0600, Jim Fehlig wrote:
>> When security drivers are active but confinement is not enabled,
>> there is no need to autogenerate <seclabel> elements when starting
>> a domain def that contains no <seclabel> elements. In fact,
>> autogenerating the elements can result in needless save/restore and
>> migration failures when the security driver is not active on the
>> restore/migration target.
>>
>> This patch changes the virSecurityManagerGenLabel function in
>> src/security_manager.c to only autogenerate a <seclabel> element
>> if none is already defined for the domain *and* default
>> confinement is enabled. Otherwise the needless <seclabel>
>> autogeneration is skipped.
>>
>> Resolves: https://bugzilla.opensuse.org/show_bug.cgi?id=1051017
>> Signed-off-by: Jim Fehlig <jfehlig@suse.com>
>> ---
>>
>> V2: Don't autogenerate a seclabel if domain does not contain one
>>      and confinement is disabled.
>>
>>   src/security/security_manager.c | 42 +++++++++++++++++++++--------------------
>>   1 file changed, 22 insertions(+), 20 deletions(-)
>>
>> diff --git a/src/security/security_manager.c b/src/security/security_manager.c
>> index 013bbc37e..10515c314 100644
>> --- a/src/security/security_manager.c
>> +++ b/src/security/security_manager.c
>> @@ -650,30 +650,32 @@ virSecurityManagerGenLabel(virSecurityManagerPtr mgr,
>>       for (i = 0; sec_managers[i]; i++) {
>>           generated = false;
>>           seclabel = virDomainDefGetSecurityLabelDef(vm, sec_managers[i]->drv->name);
>> -        if (!seclabel) {
>> -            if (!(seclabel = virSecurityLabelDefNew(sec_managers[i]->drv->name)))
>> -                goto cleanup;
>> -            generated = seclabel->implicit = true;
>> -        }
>> +        if (seclabel) {
> 
> Just a tiny nitpick, generally we prefer the 'if' block to be shorter than the
> corresponding 'else' block.

Thanks for the review! Sorry, but I'm not sure what you mean by "shorter". Do 
you mean the 'if' block should contain fewer lines of code than the 'else' block?

Regards,
Jim

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On Fri, Aug 18, 2017 at 12:18:20AM -0600, Jim Fehlig wrote:
> On 08/17/2017 02:17 AM, Erik Skultety wrote:
> > On Wed, Aug 16, 2017 at 05:54:08PM -0600, Jim Fehlig wrote:
> > > When security drivers are active but confinement is not enabled,
> > > there is no need to autogenerate <seclabel> elements when starting
> > > a domain def that contains no <seclabel> elements. In fact,
> > > autogenerating the elements can result in needless save/restore and
> > > migration failures when the security driver is not active on the
> > > restore/migration target.
> > >
> > > This patch changes the virSecurityManagerGenLabel function in
> > > src/security_manager.c to only autogenerate a <seclabel> element
> > > if none is already defined for the domain *and* default
> > > confinement is enabled. Otherwise the needless <seclabel>
> > > autogeneration is skipped.
> > >
> > > Resolves: https://bugzilla.opensuse.org/show_bug.cgi?id=1051017
> > > Signed-off-by: Jim Fehlig <jfehlig@suse.com>
> > > ---
> > >
> > > V2: Don't autogenerate a seclabel if domain does not contain one
> > >      and confinement is disabled.
> > >
> > >   src/security/security_manager.c | 42 +++++++++++++++++++++--------------------
> > >   1 file changed, 22 insertions(+), 20 deletions(-)
> > >
> > > diff --git a/src/security/security_manager.c b/src/security/security_manager.c
> > > index 013bbc37e..10515c314 100644
> > > --- a/src/security/security_manager.c
> > > +++ b/src/security/security_manager.c
> > > @@ -650,30 +650,32 @@ virSecurityManagerGenLabel(virSecurityManagerPtr mgr,
> > >       for (i = 0; sec_managers[i]; i++) {
> > >           generated = false;
> > >           seclabel = virDomainDefGetSecurityLabelDef(vm, sec_managers[i]->drv->name);
> > > -        if (!seclabel) {
> > > -            if (!(seclabel = virSecurityLabelDefNew(sec_managers[i]->drv->name)))
> > > -                goto cleanup;
> > > -            generated = seclabel->implicit = true;
> > > -        }
> > > +        if (seclabel) {
> >
> > Just a tiny nitpick, generally we prefer the 'if' block to be shorter than the
> > corresponding 'else' block.
>
> Thanks for the review! Sorry, but I'm not sure what you mean by "shorter".
> Do you mean the 'if' block should contain fewer lines of code than the
> 'else' block?

Yeah, that's exactly what I meant, I'm sorry, not being a native speaker once
again resulted in a poor choice of wording :/. Next time I'll do better in
expressing myself more precisely, I promise :).

Erik

>
> Regards,
> Jim

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On 08/18/2017 01:44 AM, Erik Skultety wrote:
> On Fri, Aug 18, 2017 at 12:18:20AM -0600, Jim Fehlig wrote:
>> On 08/17/2017 02:17 AM, Erik Skultety wrote:
>>> On Wed, Aug 16, 2017 at 05:54:08PM -0600, Jim Fehlig wrote:
>>>> When security drivers are active but confinement is not enabled,
>>>> there is no need to autogenerate <seclabel> elements when starting
>>>> a domain def that contains no <seclabel> elements. In fact,
>>>> autogenerating the elements can result in needless save/restore and
>>>> migration failures when the security driver is not active on the
>>>> restore/migration target.
>>>>
>>>> This patch changes the virSecurityManagerGenLabel function in
>>>> src/security_manager.c to only autogenerate a <seclabel> element
>>>> if none is already defined for the domain *and* default
>>>> confinement is enabled. Otherwise the needless <seclabel>
>>>> autogeneration is skipped.
>>>>
>>>> Resolves: https://bugzilla.opensuse.org/show_bug.cgi?id=1051017
>>>> Signed-off-by: Jim Fehlig <jfehlig@suse.com>
>>>> ---
>>>>
>>>> V2: Don't autogenerate a seclabel if domain does not contain one
>>>>       and confinement is disabled.
>>>>
>>>>    src/security/security_manager.c | 42 +++++++++++++++++++++--------------------
>>>>    1 file changed, 22 insertions(+), 20 deletions(-)
>>>>
>>>> diff --git a/src/security/security_manager.c b/src/security/security_manager.c
>>>> index 013bbc37e..10515c314 100644
>>>> --- a/src/security/security_manager.c
>>>> +++ b/src/security/security_manager.c
>>>> @@ -650,30 +650,32 @@ virSecurityManagerGenLabel(virSecurityManagerPtr mgr,
>>>>        for (i = 0; sec_managers[i]; i++) {
>>>>            generated = false;
>>>>            seclabel = virDomainDefGetSecurityLabelDef(vm, sec_managers[i]->drv->name);
>>>> -        if (!seclabel) {
>>>> -            if (!(seclabel = virSecurityLabelDefNew(sec_managers[i]->drv->name)))
>>>> -                goto cleanup;
>>>> -            generated = seclabel->implicit = true;
>>>> -        }
>>>> +        if (seclabel) {
>>>
>>> Just a tiny nitpick, generally we prefer the 'if' block to be shorter than the
>>> corresponding 'else' block.
>>
>> Thanks for the review! Sorry, but I'm not sure what you mean by "shorter".
>> Do you mean the 'if' block should contain fewer lines of code than the
>> 'else' block?
> 
> Yeah, that's exactly what I meant, I'm sorry, not being a native speaker once
> again resulted in a poor choice of wording :/. Next time I'll do better in
> expressing myself more precisely, I promise :).

I think you were pretty clear, its just that I've been around libvirt a long 
time and don't recall hearing such a preference. I was simply double checking :-).

I've pushed this one after making the suggested change.

Regards,
Jim

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