sysext: make some calls available via varlink

src/shared/discover-image.c

@@ -1353,6 +1353,24 @@ bool image_in_search_path(
         return false;
 }
 
+int image_to_json(const struct Image *img, JsonVariant **ret) {
+        assert(img);
+
+        return json_build(ret,
+                          JSON_BUILD_OBJECT(
+                                          JSON_BUILD_PAIR_STRING("Type", image_type_to_string(img->type)),
+                                          JSON_BUILD_PAIR_STRING("Class", image_class_to_string(img->class)),
+                                          JSON_BUILD_PAIR_STRING("Name", img->name),
+                                          JSON_BUILD_PAIR_CONDITION(img->path, "Path", JSON_BUILD_STRING(img->path)),
+                                          JSON_BUILD_PAIR_BOOLEAN("ReadOnly", img->read_only),
+                                          JSON_BUILD_PAIR_CONDITION(img->crtime != 0, "CreationTimestamp", JSON_BUILD_UNSIGNED(img->crtime)),
+                                          JSON_BUILD_PAIR_CONDITION(img->mtime != 0, "ModificationTimestamp", JSON_BUILD_UNSIGNED(img->mtime)),
+                                          JSON_BUILD_PAIR_CONDITION(img->usage != UINT64_MAX, "Usage", JSON_BUILD_UNSIGNED(img->usage)),
+                                          JSON_BUILD_PAIR_CONDITION(img->usage_exclusive != UINT64_MAX, "UsageExclusive", JSON_BUILD_UNSIGNED(img->usage_exclusive)),
+                                          JSON_BUILD_PAIR_CONDITION(img->limit != UINT64_MAX, "Limit", JSON_BUILD_UNSIGNED(img->limit)),
+                                          JSON_BUILD_PAIR_CONDITION(img->limit_exclusive != UINT64_MAX, "LimitExclusive", JSON_BUILD_UNSIGNED(img->limit_exclusive))));
+}
+
 static const char* const image_type_table[_IMAGE_TYPE_MAX] = {
         [IMAGE_DIRECTORY] = "directory",
         [IMAGE_SUBVOLUME] = "subvolume",

src/shared/discover-image.h

@@ -8,6 +8,7 @@
 
 #include "hashmap.h"
 #include "image-policy.h"
+#include "json.h"
 #include "lock-util.h"
 #include "macro.h"
 #include "os-util.h"
@@ -116,4 +117,6 @@ static inline bool IMAGE_IS_HOST(const struct Image *i) {
         return false;
 }
 
+int image_to_json(const struct Image *i, JsonVariant **ret);
+
 extern const struct hash_ops image_hash_ops;

src/shared/meson.build

@@ -175,6 +175,7 @@ shared_sources = files(
         'varlink-io.systemd.Resolve.c',
         'varlink-io.systemd.UserDatabase.c',
         'varlink-io.systemd.oom.c',
+        'varlink-io.systemd.sysext.c',
         'varlink-org.varlink.service.c',
         'verb-log-control.c',
         'verbs.c',

src/shared/varlink-io.systemd.sysext.c

@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include "varlink-io.systemd.sysext.h"
+
+static VARLINK_DEFINE_ENUM_TYPE(
+                ImageClass,
+                VARLINK_DEFINE_ENUM_VALUE(sysext),
+                VARLINK_DEFINE_ENUM_VALUE(confext));
+
+static VARLINK_DEFINE_ENUM_TYPE(
+                ImageType,
+                VARLINK_DEFINE_ENUM_VALUE(directory),
+                VARLINK_DEFINE_ENUM_VALUE(subvolume),
+                VARLINK_DEFINE_ENUM_VALUE(raw),
+                VARLINK_DEFINE_ENUM_VALUE(block));
+
+static VARLINK_DEFINE_METHOD(
+                Merge,
+                VARLINK_DEFINE_INPUT_BY_TYPE(class, ImageClass, VARLINK_NULLABLE),
+                VARLINK_DEFINE_INPUT(force, VARLINK_BOOL, VARLINK_NULLABLE),
+                VARLINK_DEFINE_INPUT(noReload, VARLINK_BOOL, VARLINK_NULLABLE),
+                VARLINK_DEFINE_INPUT(noexec, VARLINK_BOOL, VARLINK_NULLABLE));
+
+static VARLINK_DEFINE_METHOD(
+                Unmerge,
+                VARLINK_DEFINE_INPUT_BY_TYPE(class, ImageClass, VARLINK_NULLABLE),
+                VARLINK_DEFINE_INPUT(noReload, VARLINK_BOOL, VARLINK_NULLABLE));
+
+static VARLINK_DEFINE_METHOD(
+                Refresh,
+                VARLINK_DEFINE_INPUT_BY_TYPE(class, ImageClass, VARLINK_NULLABLE),
+                VARLINK_DEFINE_INPUT(force, VARLINK_BOOL, VARLINK_NULLABLE),
+                VARLINK_DEFINE_INPUT(noReload, VARLINK_BOOL, VARLINK_NULLABLE),
+                VARLINK_DEFINE_INPUT(noexec, VARLINK_BOOL, VARLINK_NULLABLE));
+
+static VARLINK_DEFINE_METHOD(
+                List,
+                VARLINK_DEFINE_INPUT_BY_TYPE(class, ImageClass, VARLINK_NULLABLE),
+                VARLINK_DEFINE_OUTPUT_BY_TYPE(Class, ImageClass, 0),
+                VARLINK_DEFINE_OUTPUT_BY_TYPE(Type, ImageType, 0),
+                VARLINK_DEFINE_OUTPUT(Name, VARLINK_STRING, 0),
+                VARLINK_DEFINE_OUTPUT(Path, VARLINK_STRING, VARLINK_NULLABLE),
+                VARLINK_DEFINE_OUTPUT(ReadOnly, VARLINK_BOOL, 0),
+                VARLINK_DEFINE_OUTPUT(CreationTimestamp, VARLINK_INT, VARLINK_NULLABLE),
+                VARLINK_DEFINE_OUTPUT(ModificationTimestamp, VARLINK_INT, VARLINK_NULLABLE),
+                VARLINK_DEFINE_OUTPUT(Usage, VARLINK_INT, VARLINK_NULLABLE),
+                VARLINK_DEFINE_OUTPUT(UsageExclusive, VARLINK_INT, VARLINK_NULLABLE),
+                VARLINK_DEFINE_OUTPUT(Limit, VARLINK_INT, VARLINK_NULLABLE),
+                VARLINK_DEFINE_OUTPUT(LimitExclusive, VARLINK_INT, VARLINK_NULLABLE));
+
+static VARLINK_DEFINE_ERROR(NoImagesFound);
+
+static VARLINK_DEFINE_ERROR(
+                AlreadyMerged,
+                VARLINK_DEFINE_FIELD(hierarchy, VARLINK_STRING, 0));
+
+VARLINK_DEFINE_INTERFACE(
+                io_systemd_sysext,
+                "io.systemd.sysext",
+                &vl_type_ImageClass,
+                &vl_type_ImageType,
+                &vl_method_Merge,
+                &vl_method_Unmerge,
+                &vl_method_Refresh,
+                &vl_method_List,
+                &vl_error_NoImagesFound,
+                &vl_error_AlreadyMerged);

src/shared/varlink-io.systemd.sysext.h

@@ -0,0 +1,6 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+#pragma once
+
+#include "varlink-idl.h"
+
+extern const VarlinkInterface vl_interface_io_systemd_sysext;