WIP: rollback status introspection

Signed-off-by: g2flyer <michael.steiner@intel.com>

libos/include/libos_fs_pseudo.h

@@ -229,6 +229,7 @@ int proc_ipc_thread_follow_link(struct libos_dentry* dent, char** out_target);
 
 int init_devfs(void);
 int init_attestation(struct pseudo_node* dev);
+int init_rollback(struct pseudo_node* dev);
 
 /* sysfs */
 

libos/src/fs/dev/fs.c

@@ -176,5 +176,9 @@ int init_devfs(void) {
     if (ret < 0)
         return ret;
 
+    ret = init_rollback(root);
+    if (ret < 0)
+        return ret;
+
     return 0;
 }

libos/src/fs/dev/rollback.c

@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/* Copyright (C) 2024 Intel Labs
+ *                    Michael Steiner <michael.steiner@intel.com>
+ */
+
+/*!
+ * \file
+ *
+ * This file contains a pseudo-device for an application to inspect the rollback protection state.
+ * `/dev/rollback/<path> pseudo-file.
+ *
+ */
+
+// TODO (MST): also add pseudo file to get hash of the last seen root hash (or, better for
+// atomicity, status ahd hash)
+
+#include "api.h"
+#include "libos_fs_encrypted.h"
+#include "libos_fs_pseudo.h"
+#include "pal.h"
+#include "toml_utils.h"
+
+static int path_load(struct libos_dentry* dent, char** out_data, size_t* out_size) {
+    // TODO (MST): implement me
+    // - find volume matching path
+    //   - libos/include/libos_fs.h:int walk_mounts(int (*walk)(struct libos_mount* mount, void*
+    //     arg), void* arg);
+    //   - libos_mount* find_mount_from_uri(const char* uri) path_lookupat(start, path,
+    //   - lookup_flags, &dent);
+    //
+    // - find (relative) path in map
+    /*
+    struct libos_encrypted_volume_state_map* file_state = NULL;
+    lock(&(enc->volume->files_state_map_lock));
+    HASH_FIND_STR(enc->volume->files_state_map, norm_path, file_state);
+    unlock(&(enc->volume->files_state_map_lock));
+    */
+    // - prepare outpub buffer with map entry
+    /*
+   if (is_set) {
+        char* buf = malloc(sizeof(pf_key));
+        if (!buf)
+            return -ENOMEM;
+        memcpy(buf, &pf_key, sizeof(pf_key));
+
+        *out_data = buf;
+        *out_size = sizeof(pf_key);
+    } else {
+        *out_data = NULL;
+        *out_size = 0;
+    }
+    */
+    __UNUSED(dent);
+    __UNUSED(out_data);
+    __UNUSED(out_size);
+    return 0;
+}
+
+int init_rollback(struct pseudo_node* dev) {
+    struct pseudo_node* rollback_dir = pseudo_add_dir(dev, "rollback");
+    pseudo_add_str(rollback_dir, "file_status", &path_load);
+
+    return 0;
+}

libos/src/meson.build

@@ -19,6 +19,7 @@ libos_sources = files(
     'fs/chroot/fs.c',
     'fs/dev/attestation.c',
     'fs/dev/fs.c',
+    'fs/dev/rollback.c',
     'fs/etc/fs.c',
     'fs/eventfd/fs.c',
     'fs/libos_dcache.c',

libos/test/regression/meson.build

@@ -100,6 +100,7 @@ tests = {
     'readdir': {},
     'rename_unlink': {},
     'rename_unlink_fchown': {},
+    'rollback': {},
     'run_test': {
         'include_directories': include_directories(
             # for `gramine_entry_api.h`

libos/test/regression/rollback.c

@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/* Copyright (C) 2024 Intel Corporation
+ *                    Michael Steiner <michael.steiner@intel.com>
+ */
+
+/* Test for setting and reading encrypted files keys (/dev/attestation/keys). */
+
+#include <assert.h>
+#include <err.h>
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdint.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include "rw_file.h"
+
+// TODO (MST): implement me
+// - tests
+//   - handles correctly paths which are not encryped files
+//   - reports correctly presence/absence of files
+//   - for existing files, reports correct state (one for each state)
+
+int main(int argc, char** argv) {
+    return 0;
+}

libos/test/regression/tests.toml

@@ -99,6 +99,7 @@ manifests = [
   "readdir",
   "rename_unlink",
   "rename_unlink_fchown",
+  "rollback",
   "run_test",
   "rwlock",
   "sched",

libos/test/regression/tests_musl.toml

@@ -101,6 +101,7 @@ manifests = [
   "readdir",
   "rename_unlink",
   "rename_unlink_fchown",
+  "rollback",
   "run_test",
   "rwlock",
   "sched",