src/core/dbus-scope.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include "alloc-util.h"
   4 #include "bus-common-errors.h"
   5 #include "bus-get-properties.h"
   6 #include "dbus-cgroup.h"
   7 #include "dbus-kill.h"
   8 #include "dbus-manager.h"
   9 #include "dbus-scope.h"
  10 #include "dbus-unit.h"
  11 #include "dbus-util.h"
  12 #include "dbus.h"
  13 #include "scope.h"
  14 #include "selinux-access.h"
  15 #include "unit.h"
  16
  17 int bus_scope_method_abandon(sd_bus_message *message, void *userdata, sd_bus_error *error) {
  18         Scope *s = ASSERT_PTR(userdata);
  19         int r;
  20
  21         assert(message);
  22
  23         r = mac_selinux_unit_access_check(UNIT(s), message, "stop", error);
  24         if (r < 0)
  25                 return r;
  26
  27         r = bus_verify_manage_units_async(UNIT(s)->manager, message, error);
  28         if (r < 0)
  29                 return r;
  30         if (r == 0)
  31                 return 1; /* No authorization for now, but the async polkit stuff will call us again when it has it */
  32
  33         r = scope_abandon(s);
  34         if (r == -ESTALE)
  35                 return sd_bus_error_setf(error, BUS_ERROR_SCOPE_NOT_RUNNING, "Scope %s is not running, cannot abandon.", UNIT(s)->id);
  36         if (r < 0)
  37                 return r;
  38
  39         return sd_bus_reply_method_return(message, NULL);
  40 }
  41
  42 static BUS_DEFINE_PROPERTY_GET_ENUM(property_get_result, scope_result, ScopeResult);
  43 static BUS_DEFINE_SET_TRANSIENT_PARSE(oom_policy, OOMPolicy, oom_policy_from_string);
  44
  45 const sd_bus_vtable bus_scope_vtable[] = {
  46         SD_BUS_VTABLE_START(0),
  47         SD_BUS_PROPERTY("Controller", "s", NULL, offsetof(Scope, controller), SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
  48         SD_BUS_PROPERTY("TimeoutStopUSec", "t", bus_property_get_usec, offsetof(Scope, timeout_stop_usec), SD_BUS_VTABLE_PROPERTY_CONST),
  49         SD_BUS_PROPERTY("Result", "s", property_get_result, offsetof(Scope, result), SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
  50         SD_BUS_PROPERTY("RuntimeMaxUSec", "t", bus_property_get_usec, offsetof(Scope, runtime_max_usec), SD_BUS_VTABLE_PROPERTY_CONST),
  51         SD_BUS_PROPERTY("RuntimeRandomizedExtraUSec", "t", bus_property_get_usec, offsetof(Scope, runtime_rand_extra_usec), SD_BUS_VTABLE_PROPERTY_CONST),
  52         SD_BUS_PROPERTY("OOMPolicy", "s", bus_property_get_oom_policy, offsetof(Scope, oom_policy), SD_BUS_VTABLE_PROPERTY_CONST),
  53         SD_BUS_SIGNAL("RequestStop", NULL, 0),
  54         SD_BUS_METHOD("Abandon", NULL, NULL, bus_scope_method_abandon, SD_BUS_VTABLE_UNPRIVILEGED),
  55         SD_BUS_VTABLE_END
  56 };
  57
  58 static int bus_scope_set_transient_property(
  59                 Scope *s,
  60                 const char *name,
  61                 sd_bus_message *message,
  62                 UnitWriteFlags flags,
  63                 sd_bus_error *error) {
  64
  65         Unit *u = UNIT(s);
  66         int r;
  67
  68         assert(s);
  69         assert(name);
  70         assert(message);
  71
  72         flags |= UNIT_PRIVATE;
  73
  74         if (streq(name, "TimeoutStopUSec"))
  75                 return bus_set_transient_usec(u, name, &s->timeout_stop_usec, message, flags, error);
  76
  77         if (streq(name, "RuntimeMaxUSec"))
  78                 return bus_set_transient_usec(u, name, &s->runtime_max_usec, message, flags, error);
  79
  80         if (streq(name, "RuntimeRandomizedExtraUSec"))
  81                 return bus_set_transient_usec(u, name, &s->runtime_rand_extra_usec, message, flags, error);
  82
  83         if (streq(name, "OOMPolicy"))
  84                 return bus_set_transient_oom_policy(u, name, &s->oom_policy, message, flags, error);
  85
  86         if (streq(name, "PIDs")) {
  87                 _cleanup_(sd_bus_creds_unrefp) sd_bus_creds *creds = NULL;
  88                 unsigned n = 0;
  89
  90                 r = sd_bus_message_enter_container(message, 'a', "u");
  91                 if (r < 0)
  92                         return r;
  93
  94                 for (;;) {
  95                         _cleanup_(pidref_done) PidRef pidref = PIDREF_NULL;
  96                         uint32_t upid;
  97                         pid_t pid;
  98
  99                         r = sd_bus_message_read(message, "u", &upid);
 100                         if (r < 0)
 101                                 return r;
 102                         if (r == 0)
 103                                 break;
 104
 105                         if (upid == 0) {
 106                                 if (!creds) {
 107                                         r = sd_bus_query_sender_creds(message, SD_BUS_CREDS_PID, &creds);
 108                                         if (r < 0)
 109                                                 return r;
 110                                 }
 111
 112                                 r = sd_bus_creds_get_pid(creds, &pid);
 113                                 if (r < 0)
 114                                         return r;
 115                         } else
 116                                 pid = (uid_t) upid;
 117
 118                         r = pidref_set_pid(&pidref, pid);
 119                         if (r < 0)
 120                                 return r;
 121
 122                         r = unit_pid_attachable(u, &pidref, error);
 123                         if (r < 0)
 124                                 return r;
 125
 126                         if (!UNIT_WRITE_FLAGS_NOOP(flags)) {
 127                                 r = unit_watch_pidref(u, &pidref, /* exclusive= */ false);
 128                                 if (r < 0 && r != -EEXIST)
 129                                         return r;
 130                         }
 131
 132                         n++;
 133                 }
 134
 135                 r = sd_bus_message_exit_container(message);
 136                 if (r < 0)
 137                         return r;
 138
 139                 if (n <= 0)
 140                         return -EINVAL;
 141
 142                 return 1;
 143
 144         } else if (streq(name, "Controller")) {
 145                 const char *controller;
 146
 147                 /* We can't support direct connections with this, as direct connections know no service or unique name
 148                  * concept, but the Controller field stores exactly that. */
 149                 if (sd_bus_message_get_bus(message) != u->manager->api_bus)
 150                         return sd_bus_error_set(error, SD_BUS_ERROR_NOT_SUPPORTED, "Sorry, Controller= logic only supported via the bus.");
 151
 152                 r = sd_bus_message_read(message, "s", &controller);
 153                 if (r < 0)
 154                         return r;
 155
 156                 if (!isempty(controller) && !sd_bus_service_name_is_valid(controller))
 157                         return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Controller '%s' is not a valid bus name.", controller);
 158
 159                 if (!UNIT_WRITE_FLAGS_NOOP(flags)) {
 160                         r = free_and_strdup(&s->controller, empty_to_null(controller));
 161                         if (r < 0)
 162                                 return r;
 163                 }
 164
 165                 return 1;
 166         }
 167
 168         return 0;
 169 }
 170
 171 int bus_scope_set_property(
 172                 Unit *u,
 173                 const char *name,
 174                 sd_bus_message *message,
 175                 UnitWriteFlags flags,
 176                 sd_bus_error *error) {
 177
 178         Scope *s = SCOPE(u);
 179         int r;
 180
 181         assert(s);
 182         assert(name);
 183         assert(message);
 184
 185         r = bus_cgroup_set_property(u, &s->cgroup_context, name, message, flags, error);
 186         if (r != 0)
 187                 return r;
 188
 189         if (u->load_state == UNIT_STUB) {
 190                 /* While we are created we still accept PIDs */
 191
 192                 r = bus_scope_set_transient_property(s, name, message, flags, error);
 193                 if (r != 0)
 194                         return r;
 195
 196                 r = bus_kill_context_set_transient_property(u, &s->kill_context, name, message, flags, error);
 197                 if (r != 0)
 198                         return r;
 199
 200                 if (streq(name, "User"))
 201                         return bus_set_transient_user_relaxed(u, name, &s->user, message, flags, error);
 202
 203                 if (streq(name, "Group"))
 204                         return bus_set_transient_user_relaxed(u, name, &s->group, message, flags, error);
 205         }
 206
 207         return 0;
 208 }
 209
 210 int bus_scope_commit_properties(Unit *u) {
 211         assert(u);
 212
 213         unit_realize_cgroup(u);
 214
 215         return 0;
 216 }
 217
 218 int bus_scope_send_request_stop(Scope *s) {
 219         _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL;
 220         _cleanup_free_ char *p = NULL;
 221         int r;
 222
 223         assert(s);
 224
 225         if (!s->controller)
 226                 return 0;
 227
 228         p = unit_dbus_path(UNIT(s));
 229         if (!p)
 230                 return -ENOMEM;
 231
 232         r = sd_bus_message_new_signal(
 233                         UNIT(s)->manager->api_bus,
 234                         &m,
 235                         p,
 236                         "org.freedesktop.systemd1.Scope",
 237                         "RequestStop");
 238         if (r < 0)
 239                 return r;
 240
 241         return sd_bus_send_to(UNIT(s)->manager->api_bus, m, s->controller, NULL);
 242 }
 243
 244 static int on_controller_gone(sd_bus_track *track, void *userdata) {
 245         Scope *s = userdata;
 246
 247         assert(track);
 248
 249         if (s->controller) {
 250                 log_unit_debug(UNIT(s), "Controller %s disappeared from bus.", s->controller);
 251                 unit_add_to_dbus_queue(UNIT(s));
 252                 s->controller = mfree(s->controller);
 253         }
 254
 255         s->controller_track = sd_bus_track_unref(s->controller_track);
 256
 257         return 0;
 258 }
 259
 260 int bus_scope_track_controller(Scope *s) {
 261         int r;
 262
 263         assert(s);
 264
 265         if (!s->controller || s->controller_track)
 266                 return 0;
 267
 268         r = sd_bus_track_new(UNIT(s)->manager->api_bus, &s->controller_track, on_controller_gone, s);
 269         if (r < 0)
 270                 return r;
 271
 272         r = sd_bus_track_add_name(s->controller_track, s->controller);
 273         if (r < 0) {
 274                 s->controller_track = sd_bus_track_unref(s->controller_track);
 275                 return r;
 276         }
 277
 278         return 0;
 279 }