[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]

Re: [libvirt] [Qemu-devel] [PATCH v2 2/4] qapi: Add passfd QMP command





On 06/13/2012 03:46 PM, Luiz Capitulino wrote:
On Fri,  8 Jun 2012 11:42:57 -0400
Corey Bryant <coreyb linux vnet ibm com> wrote:

This patch adds the passfd QMP command using the QAPI framework.
Like the getfd command, it is used to pass a file descriptor via
SCM_RIGHTS.  However, the passfd command also returns the received
file descriptor, which is a difference in behavior from the getfd
command, which returns nothing.

Let's call it pass-fd instead.

Sure, that works for me.


Also, getfd automatically closes a fd if an existing fdname is passed again.
I don't think this is a good behavior, I think pass-fd should fail instead
(note that we can't fix getfd though).


I agree. It makes sense to fail rather than blindly closing the existing fd. It can be closed explicitly with closefd if the user wants it closed.


The closefd command can be used to close a file descriptor that was
passed with the passfd command.

v2:
  -Introduce new QMP command to pass/return fd (lcapitulino redhat com)
  -Use passfd as command name (berrange redhat com)

Signed-off-by: Corey Bryant <coreyb linux vnet ibm com>
---
  monitor.c        |   14 ++++++++++----
  qapi-schema.json |   15 +++++++++++++++
  qmp-commands.hx  |   27 +++++++++++++++++++++++++++
  3 files changed, 52 insertions(+), 4 deletions(-)

diff --git a/monitor.c b/monitor.c
index 4c53cb6..980a226 100644
--- a/monitor.c
+++ b/monitor.c
@@ -2182,7 +2182,7 @@ static void do_inject_mce(Monitor *mon, const QDict *qdict)
  }
  #endif

-void qmp_getfd(const char *fdname, Error **errp)
+int64_t qmp_passfd(const char *fdname, Error **errp)
  {
      mon_fd_t *monfd;
      int fd;
@@ -2190,13 +2190,13 @@ void qmp_getfd(const char *fdname, Error **errp)
      fd = qemu_chr_fe_get_msgfd(cur_mon->chr);
      if (fd == -1) {
          error_set(errp, QERR_FD_NOT_SUPPLIED);
-        return;
+        return -1;
      }

      if (qemu_isdigit(fdname[0])) {
          error_set(errp, QERR_INVALID_PARAMETER_VALUE, "fdname",
                    "a name not starting with a digit");
-        return;
+        return -1;
      }

      QLIST_FOREACH(monfd, &cur_mon->fds, next) {
@@ -2206,7 +2206,7 @@ void qmp_getfd(const char *fdname, Error **errp)

          close(monfd->fd);
          monfd->fd = fd;
-        return;
+        return fd;
      }

      monfd = g_malloc0(sizeof(mon_fd_t));
@@ -2214,6 +2214,12 @@ void qmp_getfd(const char *fdname, Error **errp)
      monfd->fd = fd;

      QLIST_INSERT_HEAD(&cur_mon->fds, monfd, next);
+    return fd;
+}
+
+void qmp_getfd(const char *fdname, Error **errp)
+{
+    qmp_passfd(fdname, errp);
      return;
  }

diff --git a/qapi-schema.json b/qapi-schema.json
index 6be1d90..15da1b8 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1864,6 +1864,21 @@
  { 'command': 'netdev_del', 'data': {'id': 'str'} }

  ##
+# @passfd:
+#
+# Pass a file descriptor via SCM rights and assign it a name
+#
+# @fdname: file descriptor name
+#
+# Returns: The QEMU file descriptor that was received
+#          If file descriptor was not received, FdNotSupplied
+#          If @fdname is not valid, InvalidParameterType
+#
+# Since: 1.2.0
+##
+{ 'command': 'passfd', 'data': {'fdname': 'str'}, 'returns': 'int' }
+
+##
  # @getfd:
  #
  # Receive a file descriptor via SCM rights and assign it a name
diff --git a/qmp-commands.hx b/qmp-commands.hx
index f8c0f68..338a0b3 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -869,6 +869,33 @@ Example:
  EQMP

      {
+        .name       = "passfd",
+        .args_type  = "fdname:s",
+        .params     = "passfd name",
+        .help       = "pass a file descriptor via SCM rights and assign it a name",
+        .mhandler.cmd_new = qmp_marshal_input_passfd,
+    },
+
+SQMP
+passfd
+------
+
+Pass a file descriptor via SCM rights and assign it a name.
+
+Arguments:
+
+- "fdname": file descriptor name (json-string)
+
+Return a json-int with the QEMU file descriptor that was received.
+
+Example:
+
+-> { "execute": "passfd", "arguments": { "fdname": "fd1" } }
+<- { "return": 42 }
+
+EQMP
+
+    {
          .name       = "getfd",
          .args_type  = "fdname:s",
          .params     = "getfd name",


--
Regards,
Corey



[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]