[Qemu-devel] [PATCH v5 23/28] qapi: More rigorous checking for type safety bypass

[Eric Blake <eblake@redhat.com>]

Now that we have a way to validate every type, we can also be
stricter about enforcing that callers that want to bypass
type safety in generated code.  Prior to this patch, it didn't
matter what value was associated with the key 'gen', but it
looked odd that 'gen':'yes' could result in bypassing the
generated code.  These changes also enforce the changes made
earlier in the series for documentation and consolidation of
using '**' as the wildcard type, as well as 'gen':false as the
canonical spelling for requesting type bypass.

Signed-off-by: Eric Blake <eblake@redhat.com>
---
 scripts/qapi.py                            | 23 ++++++++++++++++++-----
 tests/qapi-schema/type-bypass-bad-gen.err  |  1 +
 tests/qapi-schema/type-bypass-bad-gen.exit |  2 +-
 tests/qapi-schema/type-bypass-bad-gen.json |  2 +-
 tests/qapi-schema/type-bypass-bad-gen.out  |  3 ---
 tests/qapi-schema/type-bypass-no-gen.err   |  1 +
 tests/qapi-schema/type-bypass-no-gen.exit  |  2 +-
 tests/qapi-schema/type-bypass-no-gen.json  |  2 +-
 tests/qapi-schema/type-bypass-no-gen.out   |  3 ---
 9 files changed, 24 insertions(+), 15 deletions(-)

diff --git a/scripts/qapi.py b/scripts/qapi.py
index 9421431..800e8e4 100644
--- a/scripts/qapi.py
+++ b/scripts/qapi.py
@@ -321,13 +321,14 @@ def check_name(expr_info, source, name, allow_optional = False):
                             "%s uses invalid name '%s'" % (source, name))

 def check_type(expr_info, source, data, allow_array = False,
-               allowed_metas = [], allow_dict = True, allow_optional = False):
+               allowed_metas = [], allow_dict = True, allow_optional = False,
+               allow_star = False):
     global all_names

     if data is None:
         return

-    if data == '**':
+    if allow_star and data == '**':
         return

     # Check if array type for data is okay
@@ -343,6 +344,10 @@ def check_type(expr_info, source, data, allow_array = False,

     # Check if type name for data is okay
     if isinstance(data, str):
+        if data == '**':
+            raise QAPIExprError(expr_info,
+                                "%s uses '**' but did not request 'gen':false"
+                                % source)
         if not data in all_names:
             raise QAPIExprError(expr_info,
                                 "%s uses unknown type '%s'"
@@ -367,19 +372,23 @@ def check_type(expr_info, source, data, allow_array = False,
                    allow_array=True,
                    allowed_metas=['built-in', 'union', 'alternate', 'struct',
                                   'enum'],
-                   allow_dict=True, allow_optional=True)
+                   allow_dict=True, allow_optional=True, allow_star=allow_star)

 def check_command(expr, expr_info):
     name = expr['command']
+    allow_star = expr.has_key('gen')
+
     check_type(expr_info, "'data' for command '%s'" % name,
                expr.get('data'),
-               allowed_metas=['union', 'struct'], allow_optional=True)
+               allowed_metas=['union', 'struct'], allow_optional=True,
+               allow_star=allow_star)
     returns_meta = ['union', 'struct']
     if name in returns_whitelist:
         returns_meta += ['built-in', 'alternate', 'enum']
     check_type(expr_info, "'returns' for command '%s'" % name,
                expr.get('returns'), allow_array=True,
-               allowed_metas=returns_meta, allow_optional=True)
+               allowed_metas=returns_meta, allow_optional=True,
+               allow_star=allow_star)

 def check_event(expr, expr_info):
     global events
@@ -574,6 +583,10 @@ def check_keys(expr_elem, meta, required, optional=[]):
             raise QAPIExprError(info,
                                 "%s '%s' has unknown key '%s'"
                                 % (meta, name, key))
+        if (key == 'gen' or key == 'success-response') and value != False:
+            raise QAPIExprError(info,
+                                "'%s' of %s '%s' should only use false value"
+                                % (key, meta, name))
     for key in required:
         if not expr.has_key(key):
             raise QAPIExprError(info,
diff --git a/tests/qapi-schema/type-bypass-bad-gen.err b/tests/qapi-schema/type-bypass-bad-gen.err
index e69de29..a83c3c6 100644
--- a/tests/qapi-schema/type-bypass-bad-gen.err
+++ b/tests/qapi-schema/type-bypass-bad-gen.err
@@ -0,0 +1 @@
+tests/qapi-schema/type-bypass-bad-gen.json:2: 'gen' of command 'foo' should only use false value
diff --git a/tests/qapi-schema/type-bypass-bad-gen.exit b/tests/qapi-schema/type-bypass-bad-gen.exit
index 573541a..d00491f 100644
--- a/tests/qapi-schema/type-bypass-bad-gen.exit
+++ b/tests/qapi-schema/type-bypass-bad-gen.exit
@@ -1 +1 @@
-0
+1
diff --git a/tests/qapi-schema/type-bypass-bad-gen.json b/tests/qapi-schema/type-bypass-bad-gen.json
index bb70bee..e8dec34 100644
--- a/tests/qapi-schema/type-bypass-bad-gen.json
+++ b/tests/qapi-schema/type-bypass-bad-gen.json
@@ -1,2 +1,2 @@
-# FIXME: 'gen' should only appear with value false
+# 'gen' should only appear with value false
 { 'command': 'foo', 'gen': 'whatever' }
diff --git a/tests/qapi-schema/type-bypass-bad-gen.out b/tests/qapi-schema/type-bypass-bad-gen.out
index e678f2c..e69de29 100644
--- a/tests/qapi-schema/type-bypass-bad-gen.out
+++ b/tests/qapi-schema/type-bypass-bad-gen.out
@@ -1,3 +0,0 @@
-[OrderedDict([('command', 'foo'), ('gen', 'whatever')])]
-[]
-[]
diff --git a/tests/qapi-schema/type-bypass-no-gen.err b/tests/qapi-schema/type-bypass-no-gen.err
index e69de29..20cef0a 100644
--- a/tests/qapi-schema/type-bypass-no-gen.err
+++ b/tests/qapi-schema/type-bypass-no-gen.err
@@ -0,0 +1 @@
+tests/qapi-schema/type-bypass-no-gen.json:2: Member 'arg' of 'data' for command 'unsafe' uses '**' but did not request 'gen':false
diff --git a/tests/qapi-schema/type-bypass-no-gen.exit b/tests/qapi-schema/type-bypass-no-gen.exit
index 573541a..d00491f 100644
--- a/tests/qapi-schema/type-bypass-no-gen.exit
+++ b/tests/qapi-schema/type-bypass-no-gen.exit
@@ -1 +1 @@
-0
+1
diff --git a/tests/qapi-schema/type-bypass-no-gen.json b/tests/qapi-schema/type-bypass-no-gen.json
index af87c19..49b5742 100644
--- a/tests/qapi-schema/type-bypass-no-gen.json
+++ b/tests/qapi-schema/type-bypass-no-gen.json
@@ -1,2 +1,2 @@
-# FIXME: type bypass should only work with 'gen':false
+# type bypass only works with 'gen':'no'
 { 'command': 'unsafe', 'data': { 'arg': '**' }, 'returns': '**' }
diff --git a/tests/qapi-schema/type-bypass-no-gen.out b/tests/qapi-schema/type-bypass-no-gen.out
index 8b2a9ac..e69de29 100644
--- a/tests/qapi-schema/type-bypass-no-gen.out
+++ b/tests/qapi-schema/type-bypass-no-gen.out
@@ -1,3 +0,0 @@
-[OrderedDict([('command', 'unsafe'), ('data', OrderedDict([('arg', '**')])), ('returns', '**')])]
-[]
-[]
-- 
2.1.0