[Qemu-devel] [PATCH v3 1/5] qapi: Convert getfd and closefd

[Corey Bryant <coreyb@linux.vnet.ibm.com>]

Signed-off-by: Corey Bryant <coreyb@linux.vnet.ibm.com>
---
v2:
 -Convert getfd and closefd to QAPI (lcapitulino@redhat.com)
 -Remove changes that returned fd from getfd (lcapitulino@redhat.com)
 -Wrap hmp_* functions around qmp_* functions (kwolf@redhat.com)
 -Move hmp_* functions to hmp.c (lcapitulino@redhat.com)
 -Drop .user_print lines (lcapitulino@redhat.com)
 -Use 'cmd' instead of 'cmd_new' for HMP (lcapitulino@redhat.com)
 -Change QMP command existance back to 0.14 (lcapitulino@redhat.com)

v3:
 -Remove unnecessary return statements from qmp_* functions
  (lcapitulino@redhat.com)
 -Add notes to QMP command describing behavior in more detail
  (lcapitulino@redhat.com, eblake@redhat.com)

 hmp-commands.hx  |    6 ++----
 hmp.c            |   18 ++++++++++++++++++
 hmp.h            |    2 ++
 monitor.c        |   32 ++++++++++++++------------------
 qapi-schema.json |   35 +++++++++++++++++++++++++++++++++++
 qmp-commands.hx  |   14 ++++++++++----
 6 files changed, 81 insertions(+), 26 deletions(-)

diff --git a/hmp-commands.hx b/hmp-commands.hx
index f5d9d91..eea8b32 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -1236,8 +1236,7 @@ ETEXI
         .args_type  = "fdname:s",
         .params     = "getfd name",
         .help       = "receive a file descriptor via SCM rights and assign it a name",
-        .user_print = monitor_user_noop,
-        .mhandler.cmd_new = do_getfd,
+        .mhandler.cmd = hmp_getfd,
     },
 
 STEXI
@@ -1253,8 +1252,7 @@ ETEXI
         .args_type  = "fdname:s",
         .params     = "closefd name",
         .help       = "close a file descriptor previously passed via SCM rights",
-        .user_print = monitor_user_noop,
-        .mhandler.cmd_new = do_closefd,
+        .mhandler.cmd = hmp_closefd,
     },
 
 STEXI
diff --git a/hmp.c b/hmp.c
index 2ce8cb9..6241856 100644
--- a/hmp.c
+++ b/hmp.c
@@ -999,3 +999,21 @@ void hmp_netdev_del(Monitor *mon, const QDict *qdict)
     qmp_netdev_del(id, &err);
     hmp_handle_error(mon, &err);
 }
+
+void hmp_getfd(Monitor *mon, const QDict *qdict)
+{
+    const char *fdname = qdict_get_str(qdict, "fdname");
+    Error *errp = NULL;
+
+    qmp_getfd(fdname, &errp);
+    hmp_handle_error(mon, &errp);
+}
+
+void hmp_closefd(Monitor *mon, const QDict *qdict)
+{
+    const char *fdname = qdict_get_str(qdict, "fdname");
+    Error *errp = NULL;
+
+    qmp_closefd(fdname, &errp);
+    hmp_handle_error(mon, &errp);
+}
diff --git a/hmp.h b/hmp.h
index 79d138d..8d2b0d7 100644
--- a/hmp.h
+++ b/hmp.h
@@ -64,5 +64,7 @@ void hmp_device_del(Monitor *mon, const QDict *qdict);
 void hmp_dump_guest_memory(Monitor *mon, const QDict *qdict);
 void hmp_netdev_add(Monitor *mon, const QDict *qdict);
 void hmp_netdev_del(Monitor *mon, const QDict *qdict);
+void hmp_getfd(Monitor *mon, const QDict *qdict);
+void hmp_closefd(Monitor *mon, const QDict *qdict);
 
 #endif
diff --git a/monitor.c b/monitor.c
index a3bc2c7..1a7f7e7 100644
--- a/monitor.c
+++ b/monitor.c
@@ -2182,48 +2182,45 @@ static void do_inject_mce(Monitor *mon, const QDict *qdict)
 }
 #endif
 
-static int do_getfd(Monitor *mon, const QDict *qdict, QObject **ret_data)
+void qmp_getfd(const char *fdname, Error **errp)
 {
-    const char *fdname = qdict_get_str(qdict, "fdname");
     mon_fd_t *monfd;
     int fd;
 
-    fd = qemu_chr_fe_get_msgfd(mon->chr);
+    fd = qemu_chr_fe_get_msgfd(cur_mon->chr);
     if (fd == -1) {
-        qerror_report(QERR_FD_NOT_SUPPLIED);
-        return -1;
+        error_set(errp, QERR_FD_NOT_SUPPLIED);
+        return;
     }
 
     if (qemu_isdigit(fdname[0])) {
-        qerror_report(QERR_INVALID_PARAMETER_VALUE, "fdname",
-                      "a name not starting with a digit");
-        return -1;
+        error_set(errp, QERR_INVALID_PARAMETER_VALUE, "fdname",
+                  "a name not starting with a digit");
+        return;
     }
 
-    QLIST_FOREACH(monfd, &mon->fds, next) {
+    QLIST_FOREACH(monfd, &cur_mon->fds, next) {
         if (strcmp(monfd->name, fdname) != 0) {
             continue;
         }
 
         close(monfd->fd);
         monfd->fd = fd;
-        return 0;
+        return;
     }
 
     monfd = g_malloc0(sizeof(mon_fd_t));
     monfd->name = g_strdup(fdname);
     monfd->fd = fd;
 
-    QLIST_INSERT_HEAD(&mon->fds, monfd, next);
-    return 0;
+    QLIST_INSERT_HEAD(&cur_mon->fds, monfd, next);
 }
 
-static int do_closefd(Monitor *mon, const QDict *qdict, QObject **ret_data)
+void qmp_closefd(const char *fdname, Error **errp)
 {
-    const char *fdname = qdict_get_str(qdict, "fdname");
     mon_fd_t *monfd;
 
-    QLIST_FOREACH(monfd, &mon->fds, next) {
+    QLIST_FOREACH(monfd, &cur_mon->fds, next) {
         if (strcmp(monfd->name, fdname) != 0) {
             continue;
         }
@@ -2232,11 +2229,10 @@ static int do_closefd(Monitor *mon, const QDict *qdict, QObject **ret_data)
         close(monfd->fd);
         g_free(monfd->name);
         g_free(monfd);
-        return 0;
+        return;
     }
 
-    qerror_report(QERR_FD_NOT_FOUND, fdname);
-    return -1;
+    error_set(errp, QERR_FD_NOT_FOUND, fdname);
 }
 
 static void do_loadvm(Monitor *mon, const QDict *qdict)
diff --git a/qapi-schema.json b/qapi-schema.json
index 3b6e346..26a6b84 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1862,3 +1862,38 @@
 # Since: 0.14.0
 ##
 { 'command': 'netdev_del', 'data': {'id': 'str'} }
+
+##
+# @getfd:
+#
+# Receive a file descriptor via SCM rights and assign it a name
+#
+# @fdname: file descriptor name
+#
+# Returns: Nothing on success
+#          If file descriptor was not received, FdNotSupplied
+#          If @fdname is not valid, InvalidParameterType
+#
+# Since: 0.14.0
+#
+# Notes: If @fdname already exists, the file descriptor assigned to
+#        it will be closed and replaced by the received file
+#        descriptor.
+#        The 'closefd' command can be used to explicitly close the
+#        file descriptor when it is no longer needed.
+##
+{ 'command': 'getfd', 'data': {'fdname': 'str'} }
+
+##
+# @closefd:
+#
+# Close a file descriptor previously passed via SCM rights
+#
+# @fdname: file descriptor name
+#
+# Returns: Nothing on success
+#          If @fdname is not found, FdNotFound
+#
+# Since: 0.14.0
+##
+{ 'command': 'closefd', 'data': {'fdname': 'str'} }
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 2e1a38e..e3cf3c5 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -873,8 +873,7 @@ EQMP
         .args_type  = "fdname:s",
         .params     = "getfd name",
         .help       = "receive a file descriptor via SCM rights and assign it a name",
-        .user_print = monitor_user_noop,
-        .mhandler.cmd_new = do_getfd,
+        .mhandler.cmd_new = qmp_marshal_input_getfd,
     },
 
 SQMP
@@ -892,6 +891,14 @@ Example:
 -> { "execute": "getfd", "arguments": { "fdname": "fd1" } }
 <- { "return": {} }
 
+Notes:
+
+(1) If the name specified by the "fdname" argument already exists,
+    the file descriptor assigned to it will be closed and replaced
+    by the received file descriptor.
+(2) The 'closefd' command can be used to explicitly close the file
+    descriptor when it is no longer needed.
+
 EQMP
 
     {
@@ -899,8 +906,7 @@ EQMP
         .args_type  = "fdname:s",
         .params     = "closefd name",
         .help       = "close a file descriptor previously passed via SCM rights",
-        .user_print = monitor_user_noop,
-        .mhandler.cmd_new = do_closefd,
+        .mhandler.cmd_new = qmp_marshal_input_closefd,
     },
 
 SQMP
-- 
1.7.10.2