[Qemu-devel] [PATCH v2 04/10] util: add QAuthZ object as an authorization base class

["Daniel P. Berrange" <berrange@redhat.com>]

The current qemu_acl module provides a simple access control
list facility inside QEMU, which is used via a set of monitor
commands acl_show, acl_policy, acl_add, acl_remove & acl_reset.

Note there is no ability to create ACLs - the network services
(eg VNC server) were expected to create ACLs that they want to
check.

There is also no way to define ACLs on the command line, nor
potentially integrate with external authorization systems like
polkit, pam, ldap lookup, etc.

The QAuthZ object defines a minimal abstract QOM class that can
be subclassed for creating different authorization providers.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
---
 MAINTAINERS          |  7 +++++
 Makefile             |  1 +
 Makefile.objs        |  2 ++
 Makefile.target      |  2 ++
 include/qemu/authz.h | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 util/Makefile.objs   |  2 ++
 util/authz.c         | 46 +++++++++++++++++++++++++++++
 7 files changed, 141 insertions(+)
 create mode 100644 include/qemu/authz.h
 create mode 100644 util/authz.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 2f5a338..9dcbde9 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1297,6 +1297,13 @@ F: include/qemu/throttle.h
 F: util/throttle.c
 L: qemu-block@nongnu.org
 
+Authorization
+M: Daniel P. Berrange <berrange@redhat.com>
+S: Maintained
+F: util/authz*
+F: include/qemu/authz*
+F: tests/test-authz-*
+
 Usermode Emulation
 ------------------
 Overall
diff --git a/Makefile b/Makefile
index 70e3ebc..903dc35 100644
--- a/Makefile
+++ b/Makefile
@@ -150,6 +150,7 @@ endif
 dummy := $(call unnest-vars,, \
                 stub-obj-y \
                 util-obj-y \
+                util-qom-obj-y \
                 qga-obj-y \
                 ivshmem-client-obj-y \
                 ivshmem-server-obj-y \
diff --git a/Makefile.objs b/Makefile.objs
index fbcaa74..8bc9a77 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -4,6 +4,8 @@ stub-obj-y = stubs/
 util-obj-y = util/ qobject/ qapi/
 util-obj-y += qmp-introspect.o qapi-types.o qapi-visit.o qapi-event.o
 
+util-qom-obj-y += util/
+
 #######################################################################
 # block-obj-y is code used by both qemu system emulation and qemu-img
 
diff --git a/Makefile.target b/Makefile.target
index 34ddb7e..9728f86 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -171,6 +171,7 @@ include $(SRC_PATH)/Makefile.objs
 dummy := $(call unnest-vars,,target-obj-y)
 target-obj-y-save := $(target-obj-y)
 dummy := $(call unnest-vars,.., \
+               util-qom-obj-y \
                block-obj-y \
                block-obj-m \
                crypto-obj-y \
@@ -183,6 +184,7 @@ target-obj-y := $(target-obj-y-save)
 all-obj-y += $(common-obj-y)
 all-obj-y += $(target-obj-y)
 all-obj-y += $(qom-obj-y)
+all-obj-y += $(util-qom-obj-y)
 all-obj-$(CONFIG_SOFTMMU) += $(block-obj-y)
 all-obj-$(CONFIG_USER_ONLY) += $(crypto-aes-obj-y)
 all-obj-$(CONFIG_SOFTMMU) += $(crypto-obj-y)
diff --git a/include/qemu/authz.h b/include/qemu/authz.h
new file mode 100644
index 0000000..89fa6da
--- /dev/null
+++ b/include/qemu/authz.h
@@ -0,0 +1,81 @@
+/*
+ * QEMU authorization framework
+ *
+ * Copyright (c) 2016 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, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef QAUTHZ_H__
+#define QAUTHZ_H__
+
+#include "qemu-common.h"
+#include "qapi/error.h"
+#include "qom/object.h"
+
+
+#define TYPE_QAUTHZ "authz"
+
+#define QAUTHZ_CLASS(klass) \
+     OBJECT_CLASS_CHECK(QAuthZClass, (klass), \
+                        TYPE_QAUTHZ)
+#define QAUTHZ_GET_CLASS(obj) \
+     OBJECT_GET_CLASS(QAuthZClass, (obj), \
+                      TYPE_QAUTHZ)
+#define QAUTHZ(obj) \
+     INTERFACE_CHECK(QAuthZ, (obj), \
+                     TYPE_QAUTHZ)
+
+typedef struct QAuthZ QAuthZ;
+typedef struct QAuthZClass QAuthZClass;
+
+/**
+ * QAuthZ:
+ *
+ * The QAuthZ class defines an API contract to be used
+ * for providing an authorization driver for network
+ * services.
+ */
+
+struct QAuthZ {
+    Object parent_obj;
+};
+
+
+struct QAuthZClass {
+    ObjectClass parent_class;
+
+    bool (*is_allowed)(QAuthZ *authz,
+                       const char *identity,
+                       Error **errp);
+};
+
+
+/**
+ * qauthz_is_allowed:
+ * @authz: the authorization object
+ * @identity: the user identity to authorize
+ * @errp: pointer to a NULL initialized error object
+ *
+ * Check if a user @identity is authorized
+ *
+ * Returns: true if @identity is authorizd, false otherwise
+ */
+bool qauthz_is_allowed(QAuthZ *authz,
+                       const char *identity,
+                       Error **errp);
+
+#endif /* QAUTHZ_H__ */
+
diff --git a/util/Makefile.objs b/util/Makefile.objs
index a8a777e..b29fb45 100644
--- a/util/Makefile.objs
+++ b/util/Makefile.objs
@@ -32,3 +32,5 @@ util-obj-y += buffer.o
 util-obj-y += timed-average.o
 util-obj-y += base64.o
 util-obj-y += log.o
+
+util-qom-obj-y += authz.o
diff --git a/util/authz.c b/util/authz.c
new file mode 100644
index 0000000..fd9f84e
--- /dev/null
+++ b/util/authz.c
@@ -0,0 +1,46 @@
+/*
+ * QEMU authorization framework
+ *
+ * Copyright (c) 2016 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, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/authz.h"
+
+bool qauthz_is_allowed(QAuthZ *authz,
+                       const char *identity,
+                       Error **errp)
+{
+    QAuthZClass *cls = QAUTHZ_GET_CLASS(authz);
+
+    return cls->is_allowed(authz, identity, errp);
+}
+
+static const TypeInfo authz_info = {
+    .parent = TYPE_OBJECT,
+    .name = TYPE_QAUTHZ,
+    .instance_size = sizeof(QAuthZ),
+    .class_size = sizeof(QAuthZClass),
+};
+
+static void qauthz_register_types(void)
+{
+    type_register_static(&authz_info);
+}
+
+type_init(qauthz_register_types)
+
-- 
2.5.0