qemu: conf: Add qemu.conf knobs for setting up TLS for NBD

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

src/qemu/libvirtd_qemu.aug

@@ -119,6 +119,9 @@ module Libvirtd_qemu =
    let vxhs_entry = bool_entry "vxhs_tls"
                  | str_entry "vxhs_tls_x509_cert_dir"
 
+   let nbd_entry = bool_entry "nbd_tls"
+                | str_entry "nbd_tls_x509_cert_dir"
+
    (* Each entry in the config is one of the following ... *)
    let entry = default_tls_entry
              | vnc_entry
@@ -138,6 +141,7 @@ module Libvirtd_qemu =
              | gluster_debug_level_entry
              | memory_entry
              | vxhs_entry
+             | nbd_entry
 
    let comment = [ label "#comment" . del /#[ \t]*/ "# " .  store /([^ \t\n][^\n]*)?/ . del /\n/ "\n" ]
    let empty = [ label "#empty" . eol ]

src/qemu/qemu.conf

@@ -297,6 +297,40 @@
 #vxhs_tls_x509_cert_dir = "/etc/pki/libvirt-vxhs"
 
 
+
+# Enable use of TLS encryption for all NBD disk devices that don't
+# specifically disable it.
+#
+# When the NBD server is set up appropriately, x509 certificates are required
+# for authentication between the client and the remote NBD server.
+#
+# It is necessary to setup CA and issue the client certificate before
+# enabling this.
+#
+#nbd_tls = 1
+
+
+# In order to override the default TLS certificate location for NBD
+# backed storage, supply a valid path to the certificate directory.
+# This is used to authenticate the NBD block device clients to the NBD
+# server.
+#
+# If the provided path does not exist, libvirtd will fail to start.
+# If the path is not provided, but nbd_tls = 1, then the
+# default_tls_x509_cert_dir path will be used.
+#
+# NBD block device clients expect the client certificate and key to be
+# present in the certificate directory along with the CA certificate.
+# Since this is only a client the server-key.pem certificate is not needed.
+# Thus a NBD directory must contain the following:
+#
+#  ca-cert.pem - the CA master certificate
+#  client-cert.pem - the client certificate signed with the ca-cert.pem
+#  client-key.pem - the client private key
+#
+#nbd_tls_x509_cert_dir = "/etc/pki/libvirt-nbd"
+
+
 # In order to override the default TLS certificate location for migration
 # certificates, supply a valid path to the certificate directory. If the
 # provided path does not exist, libvirtd will fail to start. If the path is

src/qemu/qemu_conf.c

@@ -279,6 +279,7 @@ virQEMUDriverConfigPtr virQEMUDriverConfigNew(bool privileged)
     SET_TLS_X509_CERT_DEFAULT(chardev);
     SET_TLS_X509_CERT_DEFAULT(migrate);
     SET_TLS_X509_CERT_DEFAULT(vxhs);
+    SET_TLS_X509_CERT_DEFAULT(nbd);
 
 #undef SET_TLS_X509_CERT_DEFAULT
 
@@ -378,6 +379,7 @@ static void virQEMUDriverConfigDispose(void *obj)
     VIR_FREE(cfg->chardevTLSx509secretUUID);
 
     VIR_FREE(cfg->vxhsTLSx509certdir);
+    VIR_FREE(cfg->nbdTLSx509certdir);
 
     VIR_FREE(cfg->migrateTLSx509certdir);
     VIR_FREE(cfg->migrateTLSx509secretUUID);
@@ -458,6 +460,7 @@ virQEMUDriverConfigTLSDirResetDefaults(virQEMUDriverConfigPtr cfg)
     CHECK_RESET_CERT_DIR_DEFAULT(chardev);
     CHECK_RESET_CERT_DIR_DEFAULT(migrate);
     CHECK_RESET_CERT_DIR_DEFAULT(vxhs);
+    CHECK_RESET_CERT_DIR_DEFAULT(nbd);
 
     return 0;
 }
@@ -561,6 +564,10 @@ int virQEMUDriverConfigLoadFile(virQEMUDriverConfigPtr cfg,
         goto cleanup;
     if (virConfGetValueString(conf, "vxhs_tls_x509_cert_dir", &cfg->vxhsTLSx509certdir) < 0)
         goto cleanup;
+    if (virConfGetValueBool(conf, "nbd_tls", &cfg->nbdTLS) < 0)
+        goto cleanup;
+    if (virConfGetValueString(conf, "nbd_tls_x509_cert_dir", &cfg->nbdTLSx509certdir) < 0)
+        goto cleanup;
 
 #define GET_CONFIG_TLS_CERTINFO(val) \
     do { \
@@ -992,6 +999,14 @@ virQEMUDriverConfigValidate(virQEMUDriverConfigPtr cfg)
         return -1;
     }
 
+    if (STRNEQ(cfg->nbdTLSx509certdir, SYSCONFDIR "/pki/qemu") &&
+        !virFileExists(cfg->nbdTLSx509certdir)) {
+        virReportError(VIR_ERR_CONF_SYNTAX,
+                       _("nbd_tls_x509_cert_dir directory '%s' does not exist"),
+                       cfg->nbdTLSx509certdir);
+        return -1;
+    }
+
     return 0;
 }
 

src/qemu/qemu_conf.h

@@ -207,6 +207,9 @@ struct _virQEMUDriverConfig {
 
     bool vxhsTLS;
     char *vxhsTLSx509certdir;
+
+    bool nbdTLS;
+    char *nbdTLSx509certdir;
 };
 
 /* Main driver state */

src/qemu/test_libvirtd_qemu.aug.in

@@ -27,6 +27,8 @@ module Test_libvirtd_qemu =
 { "chardev_tls_x509_secret_uuid" = "00000000-0000-0000-0000-000000000000" }
 { "vxhs_tls" = "1" }
 { "vxhs_tls_x509_cert_dir" = "/etc/pki/libvirt-vxhs" }
+{ "nbd_tls" = "1" }
+{ "nbd_tls_x509_cert_dir" = "/etc/pki/libvirt-nbd" }
 { "migrate_tls_x509_cert_dir" = "/etc/pki/libvirt-migrate" }
 { "migrate_tls_x509_verify" = "1" }
 { "migrate_tls_x509_secret_uuid" = "00000000-0000-0000-0000-000000000000" }