seitan,cooker: add wd to change work directory and mknod

./seitan-cooker demo/mknod.hjson demo/mknod.gluten demo/mknod.bpf

Start seitan with the socket option:
./seitan -s /tmp/seitan.sock -i demo/mknod.gluten

Start the container:
sudo rm -f /dev/lol
sudo chown $USER:$USER /tmp/seitan.sock
podman run -ti --runtime /usr/bin/crun \
        --security-opt label=disable \
        -v $(pwd)/test:/test \
        --annotation run.oci.seccomp_bpf_data="$(base64 -w0 demo/mknod.bpf)" \
        --annotation run.oci.seccomp.receiver=/tmp/seitan.sock fedora \
        sh -c 'mknod /dev/lol c 1 7 && ls -l /dev/lol'

1 files changed, 2 insertions, 3 deletions

diff --git a/demo/mknod.hjson b/demo/mknod.hjson
index 9660e0d..01f3c07 100644
--- a/demo/mknod.hjson
+++ b/demo/mknod.hjson
@@ -26,10 +26,9 @@
           "major": 1,
           "minor": { "tag": { "get": "minor" } }
         },
-        "ret": "x"/*,
-        "context": { "user": "init", "mnt": "caller" }*/
+        "context": { "cwd": "caller" }
       },
-    "return": { "tag": "x" }
+    "return": { "value": 0 }
   }
 ]