[Qemu-devel] [PATCH 1/3] qapi-schema: Make @password in set_password optional

[Michal Privoznik <mprivozn@redhat.com>]

So, imagine you've started a guest with ticketing enabled. You've set
some password to access your SPICE/VNC session. However, later you
want to give the access to somebody else's and therefore disable the
ticketing. Come on, be imaginative! Currently, there's no way how to
achieve this. And while there are two possible ways to fulfill the
goal: 1) invent new monitor command to disable ticketing, or 2) let
@password argument to 'set_password' monitor command be optional, I'm
choosing the latter. It's easier to implement, after all.

The idea behind, how this will work, is: if user issues the command
without the password field, it means they want to disable the
ticketing. Any subsequent call to the call with password field filled
in, will enable the ticketing again.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
---
 hmp-commands.hx  | 2 +-
 hmp.c            | 3 ++-
 qapi-schema.json | 8 +++++---
 qmp-commands.hx  | 2 +-
 qmp.c            | 6 +++++-
 5 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/hmp-commands.hx b/hmp-commands.hx
index e37bc8b..91dffb2 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -1576,7 +1576,7 @@ ETEXI
 
     {
         .name       = "set_password",
-        .args_type  = "protocol:s,password:s,connected:s?",
+        .args_type  = "protocol:s,password:s?,connected:s?",
         .params     = "protocol password action-if-connected",
         .help       = "set spice/vnc password",
         .mhandler.cmd = hmp_set_password,
diff --git a/hmp.c b/hmp.c
index b47f331..ce0d19e 100644
--- a/hmp.c
+++ b/hmp.c
@@ -1147,7 +1147,8 @@ void hmp_set_password(Monitor *mon, const QDict *qdict)
     const char *connected = qdict_get_try_str(qdict, "connected");
     Error *err = NULL;
 
-    qmp_set_password(protocol, password, !!connected, connected, &err);
+    qmp_set_password(protocol, !!password, password,
+                     !!connected, connected, &err);
     hmp_handle_error(mon, &err);
 }
 
diff --git a/qapi-schema.json b/qapi-schema.json
index e16f8eb..a0d9b38 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1561,12 +1561,14 @@
 ##
 # @set_password:
 #
-# Sets the password of a remote display session.
+# Sets (and enables) the password of a remote display session.
+# Or, optionally since 2.2.1, if no @password is passed, disables
+# password for remote display.
 #
 # @protocol: `vnc' to modify the VNC server password
 #            `spice' to modify the Spice server password
 #
-# @password: the new password
+# @password: #optional the new password
 #
 # @connected: #optional how to handle existing clients when changing the
 #                       password.  If nothing is specified, defaults to `keep'
@@ -1580,7 +1582,7 @@
 # Since: 0.14.0
 ##
 { 'command': 'set_password',
-  'data': {'protocol': 'str', 'password': 'str', '*connected': 'str'} }
+  'data': {'protocol': 'str', '*password': 'str', '*connected': 'str'} }
 
 ##
 # @expire_password:
diff --git a/qmp-commands.hx b/qmp-commands.hx
index a85d847..e926a4e 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -1753,7 +1753,7 @@ EQMP
 
     {
         .name       = "set_password",
-        .args_type  = "protocol:s,password:s,connected:s?",
+        .args_type  = "protocol:s,password:s?,connected:s?",
         .mhandler.cmd_new = qmp_marshal_input_set_password,
     },
 
diff --git a/qmp.c b/qmp.c
index 6b2c4be..4f741f9 100644
--- a/qmp.c
+++ b/qmp.c
@@ -276,13 +276,17 @@ out:
     return 0;
 }
 
-void qmp_set_password(const char *protocol, const char *password,
+void qmp_set_password(const char *protocol,
+                      bool has_password, const char *password,
                       bool has_connected, const char *connected, Error **errp)
 {
     int disconnect_if_connected = 0;
     int fail_if_connected = 0;
     int rc;
 
+    if (!has_password)
+        password = NULL;
+
     if (has_connected) {
         if (strcmp(connected, "fail") == 0) {
             fail_if_connected = 1;
-- 
2.0.5