[PATCH] testsuite: provide support for testing labeled NFS

[Stephen Smalley <sds@tycho.nsa.gov>]

Provide instructions in the README.md file, the required kernel config
options in defconfig, and a nfs.sh script for running the testsuite
within a labeled NFS mount.  This depends on the previous change to
enable running over labeled NFS without failures.

This completes the first part of
https://github.com/SELinuxProject/selinux-testsuite/issues/32.

What remains unfinished is adding tests that context mounts are properly
honored, with and without security_label in exports, for NFS, and
default labeling of NFS when neither security_label nor context mounts
are used (i.e. genfscon default of nfs_t).

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
---
 README.md | 41 +++++++++++++++++++++++++++++++++++++++++
 defconfig | 10 ++++++++++
 nfs.sh    | 13 +++++++++++++
 3 files changed, 64 insertions(+)
 create mode 100755 nfs.sh

diff --git a/README.md b/README.md
index 4352796edb2d..25ffe1233a2d 100644
--- a/README.md
+++ b/README.md
@@ -118,6 +118,47 @@ the tests:
 	tests/infiniband_pkey/ibpkey_test.conf
 	tests/infiniband_endport/ibendport_test.conf
 
+#### NFS
+
+It is possible to run most of the tests within a labeled NFS mount in
+order to exercise the NFS security labeling functionality.  Certain
+tests have been excluded from such testing due to differences between
+NFS and local filesystems; these tests will be automatically skipped.
+
+You will need to install an additional package, the package below
+is for Fedora/RHEL but other Linux distributions should have a similar
+package:
+
+* nfs-utils _(for `nfsd', `exportfs', and other NFS-related programs)_
+
+On a modern Fedora system you can install this dependency with the
+following command:
+
+	# dnf install nfs-utils
+
+If your distribution does not use systemd as its init system, you will
+need to customize the nfs.sh script found in this directory to
+correctly start and stop the nfs server.  You may also choose to not
+start/stop the nfs-server as part of the script by removing those lines
+if you are already using NFS for other reasons.
+
+Before running the tests in a labeled NFS mount, first ensure that you
+can run them successfully on a local filesystem following the standard
+instructions further below.  Any failures that occur on a local
+filesystem should also typically be expected when running over NFS.
+
+To run the tests within a labeled NFS mount, you can run the
+nfs.sh script while in the selinux-testsuite directory:
+
+       # cd selinux-testsuite
+       # ./nfs.sh
+
+The script will start the nfs-server, export the mount containing the
+testsuite directory with the security_label option to localhost, mount
+it via NFSv4.2 on /mnt/selinux-testsuite, switch to that directory,
+and run the testsuite there.  After completion, it will unmount and
+unexport the mount and then stop the nfs-server.
+
 ## Running the Tests
 
 Create a shell with the `unconfined_r` or `sysadm_r` role and the Linux
diff --git a/defconfig b/defconfig
index 7cb6a2ca7f71..8419e40b79dc 100644
--- a/defconfig
+++ b/defconfig
@@ -94,3 +94,13 @@ CONFIG_TRACEPOINTS=y
 CONFIG_BLK_DEV_LOOP=m
 CONFIG_BLK_DEV_LOOP_MIN_COUNT=0
 CONFIG_QFMT_V2=y
+
+# Test labeled NFS.
+# This is not required for SELinux operation itself.
+CONFIG_NFS_FS=m
+CONFIG_NFS_V4=m
+CONFIG_NFS_V4_2=y
+CONFIG_NFS_V4_SECURITY_LABEL=y
+CONFIG_NFSD=m
+CONFIG_NFSD_V4=y
+CONFIG_NFSD_V4_SECURITY_LABEL=y
diff --git a/nfs.sh b/nfs.sh
new file mode 100755
index 000000000000..31c66c377cae
--- /dev/null
+++ b/nfs.sh
@@ -0,0 +1,13 @@
+#!/bin/sh -e
+MOUNT=`stat --print %m .`
+TESTDIR=`pwd`
+systemctl start nfs-server
+exportfs -orw,no_root_squash,security_label localhost:$MOUNT
+mkdir -p /mnt/selinux-testsuite
+mount -t nfs -o vers=4.2 localhost:$TESTDIR /mnt/selinux-testsuite
+pushd /mnt/selinux-testsuite
+make test
+popd
+umount /mnt/selinux-testsuite
+exportfs -u localhost:$MOUNT
+systemctl stop nfs-server
-- 
2.24.1