[Qemu-devel] [PATCH 09/14] QMP: New argument checker (second part)

[Luiz Capitulino <lcapitulino@redhat.com>]

This commit introduces the second (and last) part of QMP's new
argument checker.

The job is done by check_client_args_type(), it iterates over
the client's argument qdict and for for each argument it checks
if it exists and if its type is valid.

It's important to observe the following changes from the existing
argument checker:

  - If the handler accepts an O-type argument, unknown arguments
    are passed down to it. It's up to O-type handlers to validate
    their arguments

  - Boolean types (eg. 'b' and '-') don't accept integers anymore,
    only json-bool

  - Argument types '/' and '.' are currently unsupported under QMP,
    thus they're not handled

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
---
 monitor.c |   94 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 93 insertions(+), 1 deletions(-)

diff --git a/monitor.c b/monitor.c
index edc362f..602ccdd 100644
--- a/monitor.c
+++ b/monitor.c
@@ -4144,6 +4144,95 @@ static int invalid_qmp_mode(const Monitor *mon, const char *cmd_name)
 }
 
 /*
+ * Argument validation rules:
+ *
+ * 1. The argument must exist in cmd_args qdict
+ * 2. The argument type must be the expected one
+ *
+ * Special case: If the argument doesn't exist in cmd_args and
+ *               the QMP_ACCEPT_UNKNOWNS flag is set, then the
+ *               checking is skipped for it.
+ */
+static int check_client_args_type(const QDict *client_args,
+                                  const QDict *cmd_args, int flags)
+{
+    const QDictEntry *ent;
+
+    for (ent = qdict_first(client_args); ent;ent = qdict_next(client_args,ent)){
+        QObject *obj;
+        QString *arg_type;
+        const QObject *client_arg = qdict_entry_value(ent);
+        const char *client_arg_name = qdict_entry_key(ent);
+
+        obj = qdict_get(cmd_args, client_arg_name);
+        if (!obj) {
+            if (flags & QMP_ACCEPT_UNKNOWNS) {
+                /* handler accepts unknowns */
+                continue;
+            }
+            /* client arg doesn't exist */
+            qerror_report(QERR_INVALID_PARAMETER, client_arg_name);
+            return -1;
+        }
+
+        arg_type = qobject_to_qstring(obj);
+        assert(arg_type != NULL);
+
+        /* check if argument's type is correct */
+        switch (qstring_get_str(arg_type)[0]) {
+        case 'F':
+        case 'B':
+        case 's':
+            if (qobject_type(client_arg) != QTYPE_QSTRING) {
+                qerror_report(QERR_INVALID_PARAMETER_TYPE, client_arg_name,
+                              "string");
+                return -1;
+            }
+        break;
+        case 'i':
+        case 'l':
+        case 'M':
+            if (qobject_type(client_arg) != QTYPE_QINT) {
+                qerror_report(QERR_INVALID_PARAMETER_TYPE, client_arg_name,
+                              "int");
+                return -1; 
+            }
+            break;
+        case 'f':
+        case 'T':
+            if (qobject_type(client_arg) != QTYPE_QINT &&
+                qobject_type(client_arg) != QTYPE_QFLOAT) {
+                qerror_report(QERR_INVALID_PARAMETER_TYPE, client_arg_name,
+                              "number");
+               return -1; 
+            }
+            break;
+        case 'b':
+        case '-':
+            if (qobject_type(client_arg) != QTYPE_QBOOL) {
+                qerror_report(QERR_INVALID_PARAMETER_TYPE, client_arg_name,
+                              "bool");
+               return -1; 
+            }
+            break;
+        case 'O':
+            assert(flags & QMP_ACCEPT_UNKNOWNS);
+            break;
+        case '/':
+        case '.':
+            /*
+             * These types are not supported by QMP and thus are not
+             * handled here. Fall through.
+             */
+        default:
+            abort();
+        }
+    }
+
+    return 0;
+}
+
+/*
  * - Check if the client has passed all mandatory args
  * - Set special flags for argument validation
  */
@@ -4220,6 +4309,9 @@ out:
  * Client argument checking rules:
  *
  * 1. Client must provide all mandatory arguments
+ * 2. Each argument provided by the client must be expected
+ * 3. Each argument provided by the client must have the type expected
+ *    by the command
  */
 static int qmp_check_client_args(const mon_cmd_t *cmd, QDict *client_args)
 {
@@ -4234,7 +4326,7 @@ static int qmp_check_client_args(const mon_cmd_t *cmd, QDict *client_args)
         goto out;
     }
 
-    /* TODO: Check client args type */
+    err = check_client_args_type(client_args, cmd_args, flags);
 
 out:
     QDECREF(cmd_args);
-- 
1.7.1.359.gd0b8d