1 files changed, 55 insertions, 0 deletions
diff --git a/hw/vfio-user/device.c b/hw/vfio-user/device.c
new file mode 100644
index 0000000000..4212fefd44
--- /dev/null
+++ b/hw/vfio-user/device.c
@@ -0,0 +1,55 @@
+/*
+ * vfio protocol over a UNIX socket device handling.
+ *
+ * Copyright © 2018, 2021 Oracle and/or its affiliates.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "qemu/error-report.h"
+
+#include "hw/vfio-user/device.h"
+#include "hw/vfio-user/trace.h"
+
+/*
+ * These are to defend against a malign server trying
+ * to force us to run out of memory.
+ */
+#define VFIO_USER_MAX_REGIONS   100
+#define VFIO_USER_MAX_IRQS      50
+
+bool vfio_user_get_device_info(VFIOUserProxy *proxy,
+                               struct vfio_device_info *info, Error **errp)
+{
+    VFIOUserDeviceInfo msg;
+    uint32_t argsz = sizeof(msg) - sizeof(msg.hdr);
+
+    memset(&msg, 0, sizeof(msg));
+    vfio_user_request_msg(&msg.hdr, VFIO_USER_DEVICE_GET_INFO, sizeof(msg), 0);
+    msg.argsz = argsz;
+
+    if (!vfio_user_send_wait(proxy, &msg.hdr, NULL, 0, errp)) {
+        return false;
+    }
+
+    if (msg.hdr.flags & VFIO_USER_ERROR) {
+        error_setg_errno(errp, -msg.hdr.error_reply,
+                         "VFIO_USER_DEVICE_GET_INFO failed");
+        return false;
+    }
+
+    trace_vfio_user_get_info(msg.num_regions, msg.num_irqs);
+
+    memcpy(info, &msg.argsz, argsz);
+
+    /* defend against a malicious server */
+    if (info->num_regions > VFIO_USER_MAX_REGIONS ||
+        info->num_irqs > VFIO_USER_MAX_IRQS) {
+        error_setg_errno(errp, EINVAL, "invalid reply");
+        return false;
+    }
+
+    return true;
+}