qemu-char: add qemu_chr_disconnect to close a fd accepted by listen fd

The patch introduces qemu_chr_disconnect(). The function is used for
closing a fd accepted by listen fd. Though we already have qemu_chr_delete(),
but it closes not only accepted fd but also listen fd. This new function
is used when we still want to keep listen fd.

Signed-off-by: Tetsuya Mukawa <mukawa@igel.co.jp>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Tested-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Victor Kaplansky <victork@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

2 files changed, 15 insertions, 0 deletions

diff --git a/include/sysemu/char.h b/include/sysemu/char.h
index 372a6fd40b..1eb2d0f309 100644
--- a/include/sysemu/char.h
+++ b/include/sysemu/char.h
@@ -75,6 +75,7 @@ struct CharDriverState {
     IOReadHandler *chr_read;
     void *handler_opaque;
     void (*chr_close)(struct CharDriverState *chr);
+    void (*chr_disconnect)(struct CharDriverState *chr);
     void (*chr_accept_input)(struct CharDriverState *chr);
     void (*chr_set_echo)(struct CharDriverState *chr, bool echo);
     void (*chr_set_fe_open)(struct CharDriverState *chr, int fe_open);
@@ -143,6 +144,12 @@ void qemu_chr_parse_common(QemuOpts *opts, ChardevCommon *backend);
  */
 CharDriverState *qemu_chr_new(const char *label, const char *filename,
                               void (*init)(struct CharDriverState *s));
+/**
+ * @qemu_chr_disconnect:
+ *
+ * Close a fd accpeted by character backend.
+ */
+void qemu_chr_disconnect(CharDriverState *chr);
 
 /**
  * @qemu_chr_new_noreplay:
diff --git a/qemu-char.c b/qemu-char.c
index b13ecbb025..e3127772c4 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -4012,6 +4012,13 @@ void qemu_chr_fe_release(CharDriverState *s)
     s->avail_connections++;
 }
 
+void qemu_chr_disconnect(CharDriverState *chr)
+{
+    if (chr->chr_disconnect) {
+        chr->chr_disconnect(chr);
+    }
+}
+
 static void qemu_chr_free_common(CharDriverState *chr)
 {
     g_free(chr->filename);
@@ -4389,6 +4396,7 @@ static CharDriverState *qmp_chardev_open_socket(const char *id,
     chr->chr_write = tcp_chr_write;
     chr->chr_sync_read = tcp_chr_sync_read;
     chr->chr_close = tcp_chr_close;
+    chr->chr_disconnect = tcp_chr_disconnect;
     chr->get_msgfds = tcp_get_msgfds;
     chr->set_msgfds = tcp_set_msgfds;
     chr->chr_add_client = tcp_chr_add_client;