[PATCH 02/14] qapi: add 'insecure-types' option for -compat argument

["Daniel P. Berrangé" <berrange@redhat.com>]

This introduces a new 'insecure-types' option for the 'compat'
argument that accepts three values

 * accept: Allow any usage
 * reject: Reject with an error reported
 * warn: Allow any usage, with a warning reported

For historical compatibility it defaults to 'accept'.

The 'reject' and 'warn' values will take effect for any type
that has been explicitly marked insecure, or is lacking an
explicit declaration of its security status.

This new command line option is currently a no-op, but will
become functional as following patches enable the checks.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
 include/qapi/compat-policy.h |  5 +++++
 qapi/compat.json             | 23 ++++++++++++++++++++++-
 qapi/qapi-util.c             | 30 ++++++++++++++++++++++++++++++
 3 files changed, 57 insertions(+), 1 deletion(-)

diff --git a/include/qapi/compat-policy.h b/include/qapi/compat-policy.h
index ea65e10744..f5af209069 100644
--- a/include/qapi/compat-policy.h
+++ b/include/qapi/compat-policy.h
@@ -24,6 +24,11 @@ bool compat_policy_input_ok(uint64_t features,
                             const char *kind, const char *name,
                             Error **errp);
 
+bool compat_policy_check_security(const CompatPolicy *policy,
+                                  const char *typename,
+                                  bool is_secure,
+                                  Error **errp);
+
 /*
  * Create a QObject input visitor for @obj for use with QMP
  *
diff --git a/qapi/compat.json b/qapi/compat.json
index 90b8d51cf2..d57f25e112 100644
--- a/qapi/compat.json
+++ b/qapi/compat.json
@@ -37,6 +37,23 @@
 { 'enum': 'CompatPolicyOutput',
   'data': [ 'accept', 'hide' ] }
 
+##
+# @CompatPolicySecurity:
+#
+# Policy for handling any devices or backends which do not provide a
+# security boundary to protect against untrusted environments
+#
+# @accept: Allow any usage
+#
+# @reject: Reject with an error reported
+#
+# @warn: Allow any usage, with a warning reported
+#
+# Since: 10.2
+##
+{ 'enum': 'CompatPolicySecurity',
+  'data': [ 'accept', 'reject', 'warn' ] }
+
 ##
 # @CompatPolicy:
 #
@@ -62,10 +79,14 @@
 # @unstable-output: how to handle unstable output (default 'accept')
 #     (since 6.2)
 #
+# @insecure-types: how to handle types that are not declared secure
+#     (default 'accept') (since 10.2)
+#
 # Since: 6.0
 ##
 { 'struct': 'CompatPolicy',
   'data': { '*deprecated-input': 'CompatPolicyInput',
             '*deprecated-output': 'CompatPolicyOutput',
             '*unstable-input': 'CompatPolicyInput',
-            '*unstable-output': 'CompatPolicyOutput' } }
+            '*unstable-output': 'CompatPolicyOutput',
+            '*insecure-types': 'CompatPolicySecurity' } }
diff --git a/qapi/qapi-util.c b/qapi/qapi-util.c
index 3d849fe034..38b1cec7a4 100644
--- a/qapi/qapi-util.c
+++ b/qapi/qapi-util.c
@@ -14,6 +14,7 @@
 #include "qapi/compat-policy.h"
 #include "qapi/error.h"
 #include "qemu/ctype.h"
+#include "qemu/error-report.h"
 #include "qapi/qmp/qerror.h"
 
 CompatPolicy compat_policy;
@@ -58,6 +59,35 @@ bool compat_policy_input_ok(uint64_t features,
     return true;
 }
 
+bool compat_policy_check_security(const CompatPolicy *policy,
+                                  const char *typename,
+                                  bool is_secure,
+                                  Error **errp)
+{
+    if (is_secure) {
+        return true;
+    }
+
+    switch (policy->insecure_types) {
+    case COMPAT_POLICY_SECURITY_ACCEPT:
+        return true;
+
+    case COMPAT_POLICY_SECURITY_REJECT:
+        error_setg(errp, "Type '%s' does not provide a security boundary "
+                   "to protect against untrusted data or actions", typename);
+        return false;
+
+    case COMPAT_POLICY_SECURITY_WARN:
+        warn_report("Type '%s' does not provide a security boundary "
+                    "to protect against untrusted data or actions", typename);
+        return true;
+
+    default:
+        g_assert_not_reached();
+    }
+}
+
+
 const char *qapi_enum_lookup(const QEnumLookup *lookup, int val)
 {
     assert(val >= 0 && val < lookup->size);
-- 
2.55.0