[Qemu-devel] [PATCH 13/14] qapi: convert change

[Anthony Liguori <aliguori@us.ibm.com>]

Convert the change command to QAPI and document all of its gloriousness.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
---
 blockdev.c       |   27 ++++++++----------
 blockdev.h       |    6 +++-
 hmp-commands.hx  |    3 +-
 hmp.c            |   59 ++++++++++++++++++++++++++++++++++++++++
 hmp.h            |    1 +
 monitor.c        |   78 +++++++----------------------------------------------
 qapi-schema.json |   38 ++++++++++++++++++++++++++
 qmp-commands.hx  |    3 +-
 8 files changed, 127 insertions(+), 88 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index c00c69d..3832118 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -785,8 +785,9 @@ void qmp_change_blockdev(const char *device, const char *filename,
     qmp_bdrv_open_encrypted(bs, filename, bdrv_flags, drv, password, errp);
 }
 
-int do_change_block(Monitor *mon, const char *device,
-                    const char *filename, const char *fmt)
+void deprecated_qmp_change_blockdev(const char *device, const char *filename,
+                                    bool has_format, const char *format,
+                                    Error **errp)
 {
     BlockDriverState *bs;
     BlockDriver *drv = NULL;
@@ -795,14 +796,14 @@ int do_change_block(Monitor *mon, const char *device,
 
     bs = bdrv_find(device);
     if (!bs) {
-        qerror_report(QERR_DEVICE_NOT_FOUND, device);
-        return -1;
+        error_set(errp, QERR_DEVICE_NOT_FOUND, device);
+        return;
     }
-    if (fmt) {
-        drv = bdrv_find_whitelisted_format(fmt);
+    if (has_format) {
+        drv = bdrv_find_whitelisted_format(format);
         if (!drv) {
-            qerror_report(QERR_INVALID_BLOCK_FORMAT, fmt);
-            return -1;
+            error_set(errp, QERR_INVALID_BLOCK_FORMAT, format);
+            return;
         }
     }
 
@@ -811,17 +812,13 @@ int do_change_block(Monitor *mon, const char *device,
 
     eject_device(bs, 0, &err);
     if (err) {
-        qerror_report_err(err);
-        return -1;
+        error_propagate(errp, err);
+        return;
     }
 
     qmp_bdrv_open_encrypted(bs, filename, bdrv_flags, drv, NULL, &err);
-    if (err) {
-        qerror_report_err(err);
-        return -1;
-    }
 
-    return 0;
+    error_propagate(errp, err);
 }
 
 int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data)
diff --git a/blockdev.h b/blockdev.h
index badbf01..54b142f 100644
--- a/blockdev.h
+++ b/blockdev.h
@@ -12,6 +12,7 @@
 
 #include "block.h"
 #include "qemu-queue.h"
+#include "error.h"
 
 void blockdev_mark_auto_del(BlockDriverState *bs);
 void blockdev_auto_del(BlockDriverState *bs);
@@ -59,8 +60,9 @@ DriveInfo *add_init_drive(const char *opts);
 
 void do_commit(Monitor *mon, const QDict *qdict);
 int do_block_set_passwd(Monitor *mon, const QDict *qdict, QObject **ret_data);
-int do_change_block(Monitor *mon, const char *device,
-                    const char *filename, const char *fmt);
+void deprecated_qmp_change_blockdev(const char *device, const char *filename,
+                                    bool has_format, const char *format,
+                                    Error **errp);
 int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data);
 int do_snapshot_blkdev(Monitor *mon, const QDict *qdict, QObject **ret_data);
 int do_block_resize(Monitor *mon, const QDict *qdict, QObject **ret_data);
diff --git a/hmp-commands.hx b/hmp-commands.hx
index 2f0ffa3..700d2f1 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -108,8 +108,7 @@ ETEXI
         .args_type  = "device:B,target:F,arg:s?",
         .params     = "device filename [format]",
         .help       = "change a removable medium, optional format",
-        .user_print = monitor_user_noop,
-        .mhandler.cmd_new = do_change,
+        .mhandler.cmd = hmp_change,
     },
 
 STEXI
diff --git a/hmp.c b/hmp.c
index a8ae36b..e8bca20 100644
--- a/hmp.c
+++ b/hmp.c
@@ -50,3 +50,62 @@ void hmp_block_passwd(Monitor *mon, const QDict *qdict)
         error_free(err);
     }
 }
+
+static void cb_hmp_change_bdrv_pwd(Monitor *mon, const char *password,
+                                   void *opaque)
+{
+    Error *encryption_err = opaque;
+    Error *err = NULL;
+    const char *device;
+
+    device = error_get_field(encryption_err, "device");
+
+    qmp_block_passwd(device, password, &err);
+    if (err) {
+        monitor_printf(mon, "invalid password\n");
+        error_free(err);
+    }
+
+    error_free(encryption_err);
+
+    monitor_read_command(mon, 1);
+}
+
+static void hmp_change_read_arg(Monitor *mon, const char *password,
+                                void *opaque)
+{
+    qmp_change_vnc_password(password, NULL);
+    monitor_read_command(mon, 1);
+}
+
+void hmp_change(Monitor *mon, const QDict *qdict)
+{
+    const char *device = qdict_get_str(qdict, "device");
+    const char *target = qdict_get_str(qdict, "target");
+    const char *arg = qdict_get_try_str(qdict, "arg");
+    Error *err = NULL;
+
+    if (strcmp(device, "vnc") == 0 &&
+        (strcmp(target, "passwd") == 0 ||
+         strcmp(target, "password") == 0)) {
+        if (arg == NULL) {
+            monitor_read_password(mon, hmp_change_read_arg, NULL);
+            return;
+        }
+    }
+
+    qmp_change(device, target, !!arg, arg, &err);
+    if (error_is_type(err, QERR_DEVICE_ENCRYPTED)) {
+        monitor_printf(mon, "%s (%s) is encrypted.\n",
+                       error_get_field(err, "device"),
+                       error_get_field(err, "encrypted_filename"));
+        if (!monitor_get_rs(mon)) {
+            monitor_printf(mon,
+                           "terminal does not support password prompting\n");
+            error_free(err);
+            return;
+        }
+        readline_start(monitor_get_rs(mon), "Password: ", 1,
+                       cb_hmp_change_bdrv_pwd, err);
+    }
+}
diff --git a/hmp.h b/hmp.h
index 8f72ef2..9df6ccc 100644
--- a/hmp.h
+++ b/hmp.h
@@ -20,5 +20,6 @@
 void hmp_info_name(Monitor *mon);
 void hmp_eject(Monitor *mon, const QDict *args);
 void hmp_block_passwd(Monitor *mon, const QDict *qdict);
+void hmp_change(Monitor *mon, const QDict *qdict);
 
 #endif
diff --git a/monitor.c b/monitor.c
index 5cb36cd..9801a2d 100644
--- a/monitor.c
+++ b/monitor.c
@@ -1005,78 +1005,22 @@ static int do_quit(Monitor *mon, const QDict *qdict, QObject **ret_data)
     return 0;
 }
 
-#ifdef CONFIG_VNC
-static int change_vnc_password(const char *password)
-{
-    if (!password || !password[0]) {
-        if (vnc_display_disable_login(NULL)) {
-            qerror_report(QERR_SET_PASSWD_FAILED);
-            return -1;
-        }
-        return 0;
-    }
-
-    if (vnc_display_password(NULL, password) < 0) {
-        qerror_report(QERR_SET_PASSWD_FAILED);
-        return -1;
-    }
-
-    return 0;
-}
-
-static void change_vnc_password_cb(Monitor *mon, const char *password,
-                                   void *opaque)
+void qmp_change(const char *device, const char *target,
+                bool has_arg, const char *arg, Error **err)
 {
-    change_vnc_password(password);
-    monitor_read_command(mon, 1);
-}
-
-static int do_change_vnc(Monitor *mon, const char *target, const char *arg)
-{
-    if (strcmp(target, "passwd") == 0 ||
-        strcmp(target, "password") == 0) {
-        if (arg) {
-            char password[9];
-            strncpy(password, arg, sizeof(password));
-            password[sizeof(password) - 1] = '\0';
-            return change_vnc_password(password);
+    if (strcmp(device, "vnc") == 0) {
+        if (strcmp(target, "passwd") == 0 || strcmp(target, "password") == 0) {
+            if (!has_arg || !arg[0]) {
+                vnc_display_disable_login(NULL);
+            } else {
+                qmp_change_vnc_password(arg, err);
+            }
         } else {
-            return monitor_read_password(mon, change_vnc_password_cb, NULL);
+            qmp_change_vnc_listen(target, err);
         }
     } else {
-        if (vnc_display_open(NULL, target) < 0) {
-            qerror_report(QERR_VNC_SERVER_FAILED, target);
-            return -1;
-        }
+        deprecated_qmp_change_blockdev(device, target, has_arg, arg, err);
     }
-
-    return 0;
-}
-#else
-static int do_change_vnc(Monitor *mon, const char *target, const char *arg)
-{
-    qerror_report(QERR_FEATURE_DISABLED, "vnc");
-    return -ENODEV;
-}
-#endif
-
-/**
- * do_change(): Change a removable medium, or VNC configuration
- */
-static int do_change(Monitor *mon, const QDict *qdict, QObject **ret_data)
-{
-    const char *device = qdict_get_str(qdict, "device");
-    const char *target = qdict_get_str(qdict, "target");
-    const char *arg = qdict_get_try_str(qdict, "arg");
-    int ret;
-
-    if (strcmp(device, "vnc") == 0) {
-        ret = do_change_vnc(mon, target, arg);
-    } else {
-        ret = do_change_block(mon, device, target, arg);
-    }
-
-    return ret;
 }
 
 static int set_password(Monitor *mon, const QDict *qdict, QObject **ret_data)
diff --git a/qapi-schema.json b/qapi-schema.json
index 139c6e3..f108d20 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -84,6 +84,44 @@
   'data': {'device': 'str', 'password': 'str'} }
 
 ##
+# @change:
+#
+# This command is multiple commands multiplexed together.  Generally speaking,
+# it should not be used in favor of the single purpose alternatives such as
+# @change-vnc-listen, @change-vnc-password, and @change-blockdev.
+#
+# @device: This is normally the name of a block device but it may also be 'vnc'.
+#          when it's 'vnc', then sub command depends on @target
+#
+# @target: If @device is a block device, then this is the new filename.
+#          If @device is 'vnc', then if the value 'password' selects the vnc
+#          change password command.   Otherwise, this specifies a new server URI
+#          address to listen to for VNC connections.
+#
+# @arg:    If @device is a block device, then this is an optional format to open
+#          the device with.
+#          If @device is 'vnc' and @target is 'password', this is the new VNC
+#          password to set.  If this argument is an empty string, then no future
+#          logins will be allowed.
+#
+# Returns: Nothing on success.
+#          If @device is not a valid block device, DeviceNotFound
+#          If @format is not a valid block format, InvalidBlockFormat
+#          If the new block device is encrypted, DeviceEncrypted.  Note that
+#          if this error is returned, the device has been opened successfully
+#          and an additional call to @block_passwd is required to set the
+#          device's password.  The behavior of reads and writes to the block
+#          device between when these calls are executed is undefined.
+#
+# Notes:  It is strongly recommended that this interface is not used especially
+#         for changing block devices.
+#
+# Since: 0.14.0
+##
+{ 'command': 'change',
+  'data': {'device': 'str', 'target': 'str', '*arg': 'str'} }
+
+##
 # @set-blockdev-password:
 #
 # Alias for @block_passwd.
diff --git a/qmp-commands.hx b/qmp-commands.hx
index cec7135..89b8d00 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -117,8 +117,7 @@ EQMP
         .args_type  = "device:B,target:F,arg:s?",
         .params     = "device filename [format]",
         .help       = "change a removable medium, optional format",
-        .user_print = monitor_user_noop,
-        .mhandler.cmd_new = do_change,
+        .mhandler.cmd_new = qmp_marshal_input_change,
     },
 
     {
-- 
1.7.4.1