guest agent: add supported command list to guest-info RPC

Not that there is blacklisting functionality we can no longer infer
the agent's capabilities via version. This patch extends the current
guest-info RPC to also return a list of dictionaries containing the name
of each supported RPC, along with a boolean indicating whether or not
the command has been disabled by a guest administrator/distro.

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

qapi-schema-guest.json

@@ -43,7 +43,11 @@
 #
 # Since: 0.15.0
 ##
-{ 'type': 'GuestAgentInfo', 'data': {'version': 'str'} }
+{ 'type': 'GuestAgentCommandInfo',
+  'data': { 'name': 'str', 'enabled': 'bool' } }
+{ 'type': 'GuestAgentInfo',
+  'data': { 'version': 'str',
+            'supported_commands': ['GuestAgentCommandInfo'] } }
 { 'command': 'guest-info',
   'returns': 'GuestAgentInfo' }
 

qapi/qmp-core.h

@@ -38,6 +38,7 @@ void qmp_register_command(const char *name, QmpCommandFunc *fn);
 QmpCommand *qmp_find_command(const char *name);
 QObject *qmp_dispatch(QObject *request);
 void qmp_disable_command(const char *name);
+bool qmp_command_is_enabled(const char *name);
 char **qmp_get_command_list(void);
 
 #endif

qapi/qmp-registry.c

@@ -52,6 +52,19 @@ void qmp_disable_command(const char *name)
     }
 }
 
+bool qmp_command_is_enabled(const char *name)
+{
+    QmpCommand *cmd;
+
+    QTAILQ_FOREACH(cmd, &qmp_commands, node) {
+        if (strcmp(cmd->name, name) == 0) {
+            return cmd->enabled;
+        }
+    }
+
+    return false;
+}
+
 char **qmp_get_command_list(void)
 {
     QmpCommand *cmd;

qga/guest-agent-commands.c

@@ -57,9 +57,33 @@ void qmp_guest_ping(Error **err)
 struct GuestAgentInfo *qmp_guest_info(Error **err)
 {
     GuestAgentInfo *info = g_malloc0(sizeof(GuestAgentInfo));
+    GuestAgentCommandInfo *cmd_info;
+    GuestAgentCommandInfoList *cmd_info_list;
+    char **cmd_list_head, **cmd_list;
 
     info->version = g_strdup(QGA_VERSION);
 
+    cmd_list_head = cmd_list = qmp_get_command_list();
+    if (*cmd_list_head == NULL) {
+        goto out;
+    }
+
+    while (*cmd_list) {
+        cmd_info = g_malloc0(sizeof(GuestAgentCommandInfo));
+        cmd_info->name = strdup(*cmd_list);
+        cmd_info->enabled = qmp_command_is_enabled(cmd_info->name);
+
+        cmd_info_list = g_malloc0(sizeof(GuestAgentCommandInfoList));
+        cmd_info_list->value = cmd_info;
+        cmd_info_list->next = info->supported_commands;
+        info->supported_commands = cmd_info_list;
+
+        g_free(*cmd_list);
+        cmd_list++;
+    }
+
+out:
+    g_free(cmd_list_head);
     return info;
 }