keyval: Restrict key components to valid QAPI names

Until now, key components are separated by '.'.  This leaves little
room for evolving the syntax, and is incompatible with the __RFQDN_
prefix convention for downstream extensions.

Since key components will be commonly used as QAPI member names by the
QObject input visitor, we can just as well borrow the QAPI naming
rules here: letters, digits, hyphen and period starting with a letter,
with an optional __RFQDN_ prefix for downstream extensions.

Signed-off-by: Markus Armbruster <[email protected]>
Reviewed-by: Kevin Wolf <[email protected]>
Message-Id: <[email protected]>

tests/test-keyval.c

@@ -41,6 +41,11 @@ static void test_keyval_parse(void)
     error_free_or_abort(&err);
     g_assert(!qdict);
 
+    /* Invalid non-empty key (qemu_opts_parse() doesn't care) */
+    qdict = keyval_parse("7up=val", NULL, &err);
+    error_free_or_abort(&err);
+    g_assert(!qdict);
+
     /* Overlong key */
     memset(long_key, 'a', 127);
     long_key[127] = 'z';
@@ -73,6 +78,11 @@ static void test_keyval_parse(void)
     QDECREF(qdict);
     g_free(params);
 
+    /* Crap after valid key */
+    qdict = keyval_parse("key[0]=val", NULL, &err);
+    error_free_or_abort(&err);
+    g_assert(!qdict);
+
     /* Multiple keys, last one wins */
     qdict = keyval_parse("a=1,b=2,,x,a=3", NULL, &error_abort);
     g_assert_cmpuint(qdict_size(qdict), ==, 2);

util/keyval.c

@@ -34,6 +34,8 @@
  *   doesn't have one, because R.a must be an object to satisfy a.b=1
  *   and a string to satisfy a=2.
  *
+ * Key-fragments must be valid QAPI names.
+ *
  * The length of any key-fragment must be between 1 and 127.
  *
  * Design flaw: there is no way to denote an empty non-root object.
@@ -51,12 +53,12 @@
  * where no-key is syntactic sugar for implied-key=val-no-key.
  *
  * TODO support lists
- * TODO support key-fragment with __RFQDN_ prefix (downstream extensions)
  */
 
 #include "qemu/osdep.h"
 #include "qapi/error.h"
 #include "qapi/qmp/qstring.h"
+#include "qapi/util.h"
 #include "qemu/option.h"
 
 /*
@@ -118,6 +120,7 @@ static const char *keyval_parse_one(QDict *qdict, const char *params,
     size_t len;
     char key_in_cur[128];
     QDict *cur;
+    int ret;
     QObject *next;
     QString *val;
 
@@ -137,9 +140,10 @@ static const char *keyval_parse_one(QDict *qdict, const char *params,
     cur = qdict;
     s = key;
     for (;;) {
-        for (len = 0; s + len < key_end && s[len] != '.'; len++) {
-        }
-        if (!len) {
+        ret = parse_qapi_name(s, false);
+        len = ret < 0 ? 0 : ret;
+        assert(s + len <= key_end);
+        if (!len || (s + len < key_end && s[len] != '.')) {
             assert(key != implied_key);
             error_setg(errp, "Invalid parameter '%.*s'",
                        (int)(key_end - key), key);