blob: dd6c11ab4d0df9cf69c2546e6e938a7b02ec0f1b [file] [log] [blame] [raw]
/* 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);
}