[Libguestfs] [PATCH 2/5] New API: internal-get-console-socket to support virt-rescue.

[Richard W.M. Jones]

This API intended for use by virt-rescue only gets the file descriptor
of the console socket.
---
 generator/actions_core.ml                  | 11 +++++++
 generator/actions_properties_deprecated.ml |  4 +--
 lib/Makefile.am                            |  1 +
 lib/conn-socket.c                          | 16 +++++++++-
 lib/guestfs-internal.h                     |  3 ++
 lib/rescue.c                               | 47 ++++++++++++++++++++++++++++++
 6 files changed, 79 insertions(+), 3 deletions(-)
 create mode 100644 lib/rescue.c

diff --git a/generator/actions_core.ml b/generator/actions_core.ml
index ed89f74..765a7fe 100644
--- a/generator/actions_core.ml
+++ b/generator/actions_core.ml
@@ -1722,6 +1722,17 @@ call it returns a simple true/false boolean result, instead
 of throwing an exception if a feature is not found.  For
 other documentation see C<guestfs_available>." };
 
+  { defaults with
+    name = "internal_get_console_socket"; added = (1, 37, 1);
+    style = RInt "fd", [], [];
+    visibility = VInternal;
+    test_excuse = "writing to the socket may block";
+    shortdesc = "get the appliance console socket";
+    longdesc = "\
+This call is used by L<virt-rescue(1)> to write directly to
+appliance console (for passing through keystrokes).  It should
+not normally be used by other libguestfs users." };
+
 ]
 
 let daemon_functions = [
diff --git a/generator/actions_properties_deprecated.ml b/generator/actions_properties_deprecated.ml
index 5327782..f36509e 100644
--- a/generator/actions_properties_deprecated.ml
+++ b/generator/actions_properties_deprecated.ml
@@ -128,7 +128,7 @@ See C<guestfs_set_backend> and L<guestfs(3)/BACKEND>." };
   { defaults with
     name = "set_direct"; added = (1, 0, 72);
     style = RErr, [Bool "direct"], [];
-    deprecated_by = Deprecated_no_replacement;
+    deprecated_by = Replaced_by "internal_get_console_socket";
     fish_alias = ["direct"]; config_only = true;
     blocking = false;
     shortdesc = "enable or disable direct appliance mode";
@@ -149,7 +149,7 @@ The default is disabled." };
   { defaults with
     name = "get_direct"; added = (1, 0, 72);
     style = RBool "direct", [], [];
-    deprecated_by = Deprecated_no_replacement;
+    deprecated_by = Replaced_by "internal_get_console_socket";
     blocking = false;
     shortdesc = "get direct appliance mode flag";
     longdesc = "\
diff --git a/lib/Makefile.am b/lib/Makefile.am
index e1ab1bf..774274b 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -116,6 +116,7 @@ libguestfs_la_SOURCES = \
 	private-data.c \
 	proto.c \
 	qemu.c \
+	rescue.c \
 	stringsbuf.c \
 	structs-compare.c \
 	structs-copy.c \
diff --git a/lib/conn-socket.c b/lib/conn-socket.c
index 4e1f781..43f5e67 100644
--- a/lib/conn-socket.c
+++ b/lib/conn-socket.c
@@ -1,5 +1,5 @@
 /* libguestfs
- * Copyright (C) 2013 Red Hat Inc.
+ * Copyright (C) 2013-2017 Red Hat Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -396,6 +396,19 @@ handle_log_message (guestfs_h *g,
   return 1;
 }
 
+static int
+get_console_sock (guestfs_h *g, struct connection *connv)
+{
+  struct connection_socket *conn = (struct connection_socket *) connv;
+
+  if (conn->console_sock == -1) {
+    error (g, _("console socket not connected"));
+    return -1;
+  }
+
+  return conn->console_sock;
+}
+
 static void
 free_conn_socket (guestfs_h *g, struct connection *connv)
 {
@@ -417,6 +430,7 @@ static struct connection_ops ops = {
   .read_data = read_data,
   .write_data = write_data,
   .can_read_data = can_read_data,
+  .get_console_sock = get_console_sock,
 };
 
 /**
diff --git a/lib/guestfs-internal.h b/lib/guestfs-internal.h
index 7126b88..5e9d97c 100644
--- a/lib/guestfs-internal.h
+++ b/lib/guestfs-internal.h
@@ -373,6 +373,9 @@ struct connection_ops {
    * Returns: 1 = yes, 0 = no, -1 = error
    */
   int (*can_read_data) (guestfs_h *g, struct connection *);
+
+  /* Get the console socket (to support virt-rescue). */
+  int (*get_console_sock) (guestfs_h *g, struct connection *);
 };
 
 /**
diff --git a/lib/rescue.c b/lib/rescue.c
new file mode 100644
index 0000000..ae7811a
--- /dev/null
+++ b/lib/rescue.c
@@ -0,0 +1,47 @@
+/* libguestfs
+ * Copyright (C) 2017 Red Hat Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * Support for virt-rescue(1).
+ */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <libintl.h>
+
+#include "guestfs.h"
+#include "guestfs-internal.h"
+#include "guestfs-internal-actions.h"
+
+int
+guestfs_impl_internal_get_console_socket (guestfs_h *g)
+{
+  if (!g->conn) {
+    error (g, _("no console socket, the handle must be launched"));
+    return -1;
+  }
+
+  if (!g->conn->ops->get_console_sock)
+    NOT_SUPPORTED (g, -1,
+           _("connection class does not support getting the console socket"));
+
+  return g->conn->ops->get_console_sock (g, g->conn);
+}
-- 
2.9.3