Adding upstream version 247.3.upstream/247.3upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 482 insertions, 0 deletions

diff --git a/src/core/core-varlink.c b/src/core/core-varlink.c
new file mode 100644
index 0000000..dd6c11a
--- /dev/null
+++ b/src/core/core-varlink.c
@@ -0,0 +1,482 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include "core-varlink.h"
+#include "mkdir.h"
+#include "strv.h"
+#include "user-util.h"
+#include "varlink.h"
+
+typedef struct LookupParameters {
+        const char *user_name;
+        const char *group_name;
+        union {
+                uid_t uid;
+                gid_t gid;
+        };
+        const char *service;
+} LookupParameters;
+
+static const char* const managed_oom_mode_properties[] = {
+        "ManagedOOMSwap",
+        "ManagedOOMMemoryPressure",
+};
+
+static int build_user_json(const char *user_name, uid_t uid, JsonVariant **ret) {
+        assert(user_name);
+        assert(uid_is_valid(uid));
+        assert(ret);
+
+        return json_build(ret, JSON_BUILD_OBJECT(
+                                   JSON_BUILD_PAIR("record", JSON_BUILD_OBJECT(
+                                       JSON_BUILD_PAIR("userName", JSON_BUILD_STRING(user_name)),
+                                       JSON_BUILD_PAIR("uid", JSON_BUILD_UNSIGNED(uid)),
+                                       JSON_BUILD_PAIR("gid", JSON_BUILD_UNSIGNED(uid)),
+                                       JSON_BUILD_PAIR("realName", JSON_BUILD_STRING("Dynamic User")),
+                                       JSON_BUILD_PAIR("homeDirectory", JSON_BUILD_STRING("/")),
+                                       JSON_BUILD_PAIR("shell", JSON_BUILD_STRING(NOLOGIN)),
+                                       JSON_BUILD_PAIR("locked", JSON_BUILD_BOOLEAN(true)),
+                                       JSON_BUILD_PAIR("service", JSON_BUILD_STRING("io.systemd.DynamicUser")),
+                                       JSON_BUILD_PAIR("disposition", JSON_BUILD_STRING("dynamic"))))));
+}
+
+static bool user_match_lookup_parameters(LookupParameters *p, const char *name, uid_t uid) {
+        assert(p);
+
+        if (p->user_name && !streq(name, p->user_name))
+                return false;
+
+        if (uid_is_valid(p->uid) && uid != p->uid)
+                return false;
+
+        return true;
+}
+
+static int build_managed_oom_json_array_element(Unit *u, const char *property, JsonVariant **ret_v) {
+        bool use_limit = false;
+        CGroupContext *c;
+        const char *mode;
+
+        assert(u);
+        assert(property);
+        assert(ret_v);
+
+        if (!UNIT_VTABLE(u)->can_set_managed_oom)
+                return -EOPNOTSUPP;
+
+        c = unit_get_cgroup_context(u);
+        if (!c)
+                return -EINVAL;
+
+        if (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(u)))
+                /* systemd-oomd should always treat inactive units as though they didn't enable any action since they
+                 * should not have a valid cgroup */
+                mode = managed_oom_mode_to_string(MANAGED_OOM_AUTO);
+        else if (streq(property, "ManagedOOMSwap"))
+                mode = managed_oom_mode_to_string(c->moom_swap);
+        else if (streq(property, "ManagedOOMMemoryPressure")) {
+                mode = managed_oom_mode_to_string(c->moom_mem_pressure);
+                use_limit = true;
+        } else
+                return -EINVAL;
+
+        return json_build(ret_v, JSON_BUILD_OBJECT(
+                                 JSON_BUILD_PAIR("mode", JSON_BUILD_STRING(mode)),
+                                 JSON_BUILD_PAIR("path", JSON_BUILD_STRING(u->cgroup_path)),
+                                 JSON_BUILD_PAIR("property", JSON_BUILD_STRING(property)),
+                                 JSON_BUILD_PAIR_CONDITION(use_limit, "limit", JSON_BUILD_UNSIGNED(c->moom_mem_pressure_limit))));
+}
+
+int manager_varlink_send_managed_oom_update(Unit *u) {
+        _cleanup_(json_variant_unrefp) JsonVariant *arr = NULL, *v = NULL;
+        CGroupContext *c;
+        int r;
+
+        assert(u);
+
+        if (!UNIT_VTABLE(u)->can_set_managed_oom || !u->manager || !u->manager->managed_oom_varlink_request || !u->cgroup_path)
+                return 0;
+
+        c = unit_get_cgroup_context(u);
+        if (!c)
+                return 0;
+
+        r = json_build(&arr, JSON_BUILD_EMPTY_ARRAY);
+        if (r < 0)
+                return r;
+
+        for (size_t i = 0; i < ELEMENTSOF(managed_oom_mode_properties); i++) {
+                _cleanup_(json_variant_unrefp) JsonVariant *e = NULL;
+
+                r = build_managed_oom_json_array_element(u, managed_oom_mode_properties[i], &e);
+                if (r < 0)
+                        return r;
+
+                r = json_variant_append_array(&arr, e);
+                if (r < 0)
+                        return r;
+        }
+
+        r = json_build(&v, JSON_BUILD_OBJECT(JSON_BUILD_PAIR("cgroups", JSON_BUILD_VARIANT(arr))));
+        if (r < 0)
+                return r;
+
+        return varlink_notify(u->manager->managed_oom_varlink_request, v);
+}
+
+static int vl_method_subscribe_managed_oom_cgroups(
+                Varlink *link,
+                JsonVariant *parameters,
+                VarlinkMethodFlags flags,
+                void *userdata) {
+        static const UnitType supported_unit_types[] = { UNIT_SLICE, UNIT_SERVICE, UNIT_SCOPE };
+        _cleanup_(json_variant_unrefp) JsonVariant *v = NULL, *arr = NULL;
+        Manager *m = userdata;
+        int r;
+
+        assert(link);
+        assert(m);
+
+        if (json_variant_elements(parameters) > 0)
+                return varlink_error_invalid_parameter(link, parameters);
+
+        /* We only take one subscriber for this method so return an error if there's already an existing one.
+         * This shouldn't happen since systemd-oomd is the only client of this method. */
+        if (FLAGS_SET(flags, VARLINK_METHOD_MORE) && m->managed_oom_varlink_request)
+                return varlink_error(m->managed_oom_varlink_request, VARLINK_ERROR_SUBSCRIPTION_TAKEN, NULL);
+
+        r = json_build(&arr, JSON_BUILD_EMPTY_ARRAY);
+        if (r < 0)
+                return r;
+
+        for (size_t i = 0; i < ELEMENTSOF(supported_unit_types); i++) {
+                Unit *u;
+
+                LIST_FOREACH(units_by_type, u, m->units_by_type[supported_unit_types[i]]) {
+                        CGroupContext *c;
+
+                        if (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(u)))
+                                continue;
+
+                        c = unit_get_cgroup_context(u);
+                        if (!c)
+                                continue;
+
+                        for (size_t j = 0; j < ELEMENTSOF(managed_oom_mode_properties); j++) {
+                                _cleanup_(json_variant_unrefp) JsonVariant *e = NULL;
+
+                                /* For the initial varlink call we only care about units that enabled (i.e. mode is not
+                                 * set to "auto") oomd properties. */
+                                if (!(streq(managed_oom_mode_properties[j], "ManagedOOMSwap") && c->moom_swap == MANAGED_OOM_KILL) &&
+                                    !(streq(managed_oom_mode_properties[j], "ManagedOOMMemoryPressure") && c->moom_mem_pressure == MANAGED_OOM_KILL))
+                                        continue;
+
+                                r = build_managed_oom_json_array_element(u, managed_oom_mode_properties[j], &e);
+                                if (r < 0)
+                                        return r;
+
+                                r = json_variant_append_array(&arr, e);
+                                if (r < 0)
+                                        return r;
+                        }
+                }
+        }
+
+        r = json_build(&v, JSON_BUILD_OBJECT(JSON_BUILD_PAIR("cgroups", JSON_BUILD_VARIANT(arr))));
+        if (r < 0)
+                return r;
+
+        if (!FLAGS_SET(flags, VARLINK_METHOD_MORE))
+                return varlink_reply(link, v);
+
+        m->managed_oom_varlink_request = varlink_ref(link);
+        return varlink_notify(m->managed_oom_varlink_request, v);
+}
+
+static int vl_method_get_user_record(Varlink *link, JsonVariant *parameters, VarlinkMethodFlags flags, void *userdata) {
+
+        static const JsonDispatch dispatch_table[] = {
+                { "uid",      JSON_VARIANT_UNSIGNED, json_dispatch_uid_gid,      offsetof(LookupParameters, uid),       0         },
+                { "userName", JSON_VARIANT_STRING,   json_dispatch_const_string, offsetof(LookupParameters, user_name), JSON_SAFE },
+                { "service",  JSON_VARIANT_STRING,   json_dispatch_const_string, offsetof(LookupParameters, service),   0         },
+                {}
+        };
+
+        _cleanup_(json_variant_unrefp) JsonVariant *v = NULL;
+        LookupParameters p = {
+                .uid = UID_INVALID,
+        };
+        _cleanup_free_ char *found_name = NULL;
+        uid_t found_uid = UID_INVALID, uid;
+        Manager *m = userdata;
+        const char *un;
+        int r;
+
+        assert(parameters);
+        assert(m);
+
+        r = json_dispatch(parameters, dispatch_table, NULL, 0, &p);
+        if (r < 0)
+                return r;
+
+        if (!streq_ptr(p.service, "io.systemd.DynamicUser"))
+                return varlink_error(link, "io.systemd.UserDatabase.BadService", NULL);
+
+        if (uid_is_valid(p.uid))
+                r = dynamic_user_lookup_uid(m, p.uid, &found_name);
+        else if (p.user_name)
+                r = dynamic_user_lookup_name(m, p.user_name, &found_uid);
+        else {
+                DynamicUser *d;
+
+                HASHMAP_FOREACH(d, m->dynamic_users) {
+                        r = dynamic_user_current(d, &uid);
+                        if (r == -EAGAIN) /* not realized yet? */
+                                continue;
+                        if (r < 0)
+                                return r;
+
+                        if (!user_match_lookup_parameters(&p, d->name, uid))
+                                continue;
+
+                        if (v) {
+                                r = varlink_notify(link, v);
+                                if (r < 0)
+                                        return r;
+
+                                v = json_variant_unref(v);
+                        }
+
+                        r = build_user_json(d->name, uid, &v);
+                        if (r < 0)
+                                return r;
+                }
+
+                if (!v)
+                        return varlink_error(link, "io.systemd.UserDatabase.NoRecordFound", NULL);
+
+                return varlink_reply(link, v);
+        }
+        if (r == -ESRCH)
+                return varlink_error(link, "io.systemd.UserDatabase.NoRecordFound", NULL);
+        if (r < 0)
+                return r;
+
+        uid = uid_is_valid(found_uid) ? found_uid : p.uid;
+        un = found_name ?: p.user_name;
+
+        if (!user_match_lookup_parameters(&p, un, uid))
+                return varlink_error(link, "io.systemd.UserDatabase.ConflictingRecordFound", NULL);
+
+        r = build_user_json(un, uid, &v);
+        if (r < 0)
+                return r;
+
+        return varlink_reply(link, v);
+}
+
+static int build_group_json(const char *group_name, gid_t gid, JsonVariant **ret) {
+        assert(group_name);
+        assert(gid_is_valid(gid));
+        assert(ret);
+
+        return json_build(ret, JSON_BUILD_OBJECT(
+                                   JSON_BUILD_PAIR("record", JSON_BUILD_OBJECT(
+                                       JSON_BUILD_PAIR("groupName", JSON_BUILD_STRING(group_name)),
+                                       JSON_BUILD_PAIR("description", JSON_BUILD_STRING("Dynamic Group")),
+                                       JSON_BUILD_PAIR("gid", JSON_BUILD_UNSIGNED(gid)),
+                                       JSON_BUILD_PAIR("service", JSON_BUILD_STRING("io.systemd.DynamicUser")),
+                                       JSON_BUILD_PAIR("disposition", JSON_BUILD_STRING("dynamic"))))));
+    }
+
+static bool group_match_lookup_parameters(LookupParameters *p, const char *name, gid_t gid) {
+        assert(p);
+
+        if (p->group_name && !streq(name, p->group_name))
+                return false;
+
+        if (gid_is_valid(p->gid) && gid != p->gid)
+                return false;
+
+        return true;
+}
+
+static int vl_method_get_group_record(Varlink *link, JsonVariant *parameters, VarlinkMethodFlags flags, void *userdata) {
+
+        static const JsonDispatch dispatch_table[] = {
+                { "gid",       JSON_VARIANT_UNSIGNED, json_dispatch_uid_gid,      offsetof(LookupParameters, gid),        0         },
+                { "groupName", JSON_VARIANT_STRING,   json_dispatch_const_string, offsetof(LookupParameters, group_name), JSON_SAFE },
+                { "service",   JSON_VARIANT_STRING,   json_dispatch_const_string, offsetof(LookupParameters, service),    0         },
+                {}
+        };
+
+        _cleanup_(json_variant_unrefp) JsonVariant *v = NULL;
+        LookupParameters p = {
+                .gid = GID_INVALID,
+        };
+        _cleanup_free_ char *found_name = NULL;
+        uid_t found_gid = GID_INVALID, gid;
+        Manager *m = userdata;
+        const char *gn;
+        int r;
+
+        assert(parameters);
+        assert(m);
+
+        r = json_dispatch(parameters, dispatch_table, NULL, 0, &p);
+        if (r < 0)
+                return r;
+
+        if (!streq_ptr(p.service, "io.systemd.DynamicUser"))
+                return varlink_error(link, "io.systemd.UserDatabase.BadService", NULL);
+
+        if (gid_is_valid(p.gid))
+                r = dynamic_user_lookup_uid(m, (uid_t) p.gid, &found_name);
+        else if (p.group_name)
+                r = dynamic_user_lookup_name(m, p.group_name, (uid_t*) &found_gid);
+        else {
+                DynamicUser *d;
+
+                HASHMAP_FOREACH(d, m->dynamic_users) {
+                        uid_t uid;
+
+                        r = dynamic_user_current(d, &uid);
+                        if (r == -EAGAIN)
+                                continue;
+                        if (r < 0)
+                                return r;
+
+                        if (!group_match_lookup_parameters(&p, d->name, (gid_t) uid))
+                                continue;
+
+                        if (v) {
+                                r = varlink_notify(link, v);
+                                if (r < 0)
+                                        return r;
+
+                                v = json_variant_unref(v);
+                        }
+
+                        r = build_group_json(d->name, (gid_t) uid, &v);
+                        if (r < 0)
+                                return r;
+                }
+
+                if (!v)
+                        return varlink_error(link, "io.systemd.UserDatabase.NoRecordFound", NULL);
+
+                return varlink_reply(link, v);
+        }
+        if (r == -ESRCH)
+                return varlink_error(link, "io.systemd.UserDatabase.NoRecordFound", NULL);
+        if (r < 0)
+                return r;
+
+        gid = gid_is_valid(found_gid) ? found_gid : p.gid;
+        gn = found_name ?: p.group_name;
+
+        if (!group_match_lookup_parameters(&p, gn, gid))
+                return varlink_error(link, "io.systemd.UserDatabase.ConflictingRecordFound", NULL);
+
+        r = build_group_json(gn, gid, &v);
+        if (r < 0)
+                return r;
+
+        return varlink_reply(link, v);
+}
+
+static int vl_method_get_memberships(Varlink *link, JsonVariant *parameters, VarlinkMethodFlags flags, void *userdata) {
+
+        static const JsonDispatch dispatch_table[] = {
+                { "userName",  JSON_VARIANT_STRING, json_dispatch_const_string, offsetof(LookupParameters, user_name),  JSON_SAFE },
+                { "groupName", JSON_VARIANT_STRING, json_dispatch_const_string, offsetof(LookupParameters, group_name), JSON_SAFE },
+                { "service",   JSON_VARIANT_STRING, json_dispatch_const_string, offsetof(LookupParameters, service),    0         },
+                {}
+        };
+
+        LookupParameters p = {};
+        int r;
+
+        assert(parameters);
+
+        r = json_dispatch(parameters, dispatch_table, NULL, 0, &p);
+        if (r < 0)
+                return r;
+
+        if (!streq_ptr(p.service, "io.systemd.DynamicUser"))
+                return varlink_error(link, "io.systemd.UserDatabase.BadService", NULL);
+
+        /* We don't support auxiliary groups with dynamic users. */
+        return varlink_error(link, "io.systemd.UserDatabase.NoRecordFound", NULL);
+}
+
+static void vl_disconnect(VarlinkServer *s, Varlink *link, void *userdata) {
+        Manager *m = userdata;
+
+        assert(m);
+        assert(s);
+        assert(link);
+
+        if (link == m->managed_oom_varlink_request)
+                m->managed_oom_varlink_request = varlink_unref(link);
+}
+
+int manager_varlink_init(Manager *m) {
+        _cleanup_(varlink_server_unrefp) VarlinkServer *s = NULL;
+        int r;
+
+        assert(m);
+
+        if (m->varlink_server)
+                return 0;
+
+        if (!MANAGER_IS_SYSTEM(m))
+                return 0;
+
+        r = varlink_server_new(&s, VARLINK_SERVER_ACCOUNT_UID);
+        if (r < 0)
+                return log_error_errno(r, "Failed to allocate varlink server object: %m");
+
+        varlink_server_set_userdata(s, m);
+
+        r = varlink_server_bind_method_many(
+                        s,
+                        "io.systemd.UserDatabase.GetUserRecord",  vl_method_get_user_record,
+                        "io.systemd.UserDatabase.GetGroupRecord", vl_method_get_group_record,
+                        "io.systemd.UserDatabase.GetMemberships", vl_method_get_memberships,
+                        "io.systemd.ManagedOOM.SubscribeManagedOOMCGroups",  vl_method_subscribe_managed_oom_cgroups);
+        if (r < 0)
+                return log_error_errno(r, "Failed to register varlink methods: %m");
+
+        r = varlink_server_bind_disconnect(s, vl_disconnect);
+        if (r < 0)
+                return log_error_errno(r, "Failed to register varlink disconnect handler: %m");
+
+        if (!MANAGER_IS_TEST_RUN(m)) {
+                (void) mkdir_p_label("/run/systemd/userdb", 0755);
+
+                r = varlink_server_listen_address(s, "/run/systemd/userdb/io.systemd.DynamicUser", 0666);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to bind to varlink socket: %m");
+
+                r = varlink_server_listen_address(s, VARLINK_ADDR_PATH_MANAGED_OOM, 0666);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to bind to varlink socket: %m");
+        }
+
+        r = varlink_server_attach_event(s, m->event, SD_EVENT_PRIORITY_NORMAL);
+        if (r < 0)
+                return log_error_errno(r, "Failed to attach varlink connection to event loop: %m");
+
+        m->varlink_server = TAKE_PTR(s);
+        return 0;
+}
+
+void manager_varlink_done(Manager *m) {
+        assert(m);
+
+        /* Send the final message if we still have a subscribe request open. */
+        if (m->managed_oom_varlink_request)
+                m->managed_oom_varlink_request = varlink_close_unref(m->managed_oom_varlink_request);
+
+        m->varlink_server = varlink_server_unref(m->varlink_server);
+}