src/core/unit.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 #pragma once
   3
   4 #include <stdbool.h>
   5 #include <stdlib.h>
   6 #include <unistd.h>
   7
   8 #include "bpf-program.h"
   9 #include "condition.h"
  10 #include "emergency-action.h"
  11 #include "install.h"
  12 #include "list.h"
  13 #include "set.h"
  14 #include "unit-name.h"
  15 #include "cgroup.h"
  16
  17 typedef struct UnitRef UnitRef;
  18
  19 typedef enum KillOperation {
  20         KILL_TERMINATE,
  21         KILL_TERMINATE_AND_LOG,
  22         KILL_KILL,
  23         KILL_WATCHDOG,
  24         _KILL_OPERATION_MAX,
  25         _KILL_OPERATION_INVALID = -1
  26 } KillOperation;
  27
  28 typedef enum CollectMode {
  29         COLLECT_INACTIVE,
  30         COLLECT_INACTIVE_OR_FAILED,
  31         _COLLECT_MODE_MAX,
  32         _COLLECT_MODE_INVALID = -1,
  33 } CollectMode;
  34
  35 static inline bool UNIT_IS_ACTIVE_OR_RELOADING(UnitActiveState t) {
  36         return IN_SET(t, UNIT_ACTIVE, UNIT_RELOADING);
  37 }
  38
  39 static inline bool UNIT_IS_ACTIVE_OR_ACTIVATING(UnitActiveState t) {
  40         return IN_SET(t, UNIT_ACTIVE, UNIT_ACTIVATING, UNIT_RELOADING);
  41 }
  42
  43 static inline bool UNIT_IS_INACTIVE_OR_DEACTIVATING(UnitActiveState t) {
  44         return IN_SET(t, UNIT_INACTIVE, UNIT_FAILED, UNIT_DEACTIVATING);
  45 }
  46
  47 static inline bool UNIT_IS_INACTIVE_OR_FAILED(UnitActiveState t) {
  48         return IN_SET(t, UNIT_INACTIVE, UNIT_FAILED);
  49 }
  50
  51 /* Stores the 'reason' a dependency was created as a bit mask, i.e. due to which configuration source it came to be. We
  52  * use this so that we can selectively flush out parts of dependencies again. Note that the same dependency might be
  53  * created as a result of multiple "reasons", hence the bitmask. */
  54 typedef enum UnitDependencyMask {
  55         /* Configured directly by the unit file, .wants/.requires symlink or drop-in, or as an immediate result of a
  56          * non-dependency option configured that way.  */
  57         UNIT_DEPENDENCY_FILE               = 1 << 0,
  58
  59         /* As unconditional implicit dependency (not affected by unit configuration — except by the unit name and
  60          * type) */
  61         UNIT_DEPENDENCY_IMPLICIT           = 1 << 1,
  62
  63         /* A dependency effected by DefaultDependencies=yes. Note that dependencies marked this way are conceptually
  64          * just a subset of UNIT_DEPENDENCY_FILE, as DefaultDependencies= is itself a unit file setting that can only
  65          * be set in unit files. We make this two separate bits only to help debugging how dependencies came to be. */
  66         UNIT_DEPENDENCY_DEFAULT            = 1 << 2,
  67
  68         /* A dependency created from udev rules */
  69         UNIT_DEPENDENCY_UDEV               = 1 << 3,
  70
  71         /* A dependency created because of some unit's RequiresMountsFor= setting */
  72         UNIT_DEPENDENCY_PATH               = 1 << 4,
  73
  74         /* A dependency created because of data read from /proc/self/mountinfo and no other configuration source */
  75         UNIT_DEPENDENCY_MOUNTINFO_IMPLICIT = 1 << 5,
  76
  77         /* A dependency created because of data read from /proc/self/mountinfo, but conditionalized by
  78          * DefaultDependencies= and thus also involving configuration from UNIT_DEPENDENCY_FILE sources */
  79         UNIT_DEPENDENCY_MOUNTINFO_DEFAULT  = 1 << 6,
  80
  81         /* A dependency created because of data read from /proc/swaps and no other configuration source */
  82         UNIT_DEPENDENCY_PROC_SWAP          = 1 << 7,
  83
  84         _UNIT_DEPENDENCY_MASK_FULL         = (1 << 8) - 1,
  85 } UnitDependencyMask;
  86
  87 /* The Unit's dependencies[] hashmaps use this structure as value. It has the same size as a void pointer, and thus can
  88  * be stored directly as hashmap value, without any indirection. Note that this stores two masks, as both the origin
  89  * and the destination of a dependency might have created it. */
  90 typedef union UnitDependencyInfo {
  91         void *data;
  92         struct {
  93                 UnitDependencyMask origin_mask:16;
  94                 UnitDependencyMask destination_mask:16;
  95         } _packed_;
  96 } UnitDependencyInfo;
  97
  98 #include "job.h"
  99
 100 struct UnitRef {
 101         /* Keeps tracks of references to a unit. This is useful so
 102          * that we can merge two units if necessary and correct all
 103          * references to them */
 104
 105         Unit *source, *target;
 106         LIST_FIELDS(UnitRef, refs_by_target);
 107 };
 108
 109 typedef struct Unit {
 110         Manager *manager;
 111
 112         UnitType type;
 113         UnitLoadState load_state;
 114         Unit *merged_into;
 115
 116         char *id; /* One name is special because we use it for identification. Points to an entry in the names set */
 117         char *instance;
 118
 119         Set *names;
 120
 121         /* For each dependency type we maintain a Hashmap whose key is the Unit* object, and the value encodes why the
 122          * dependency exists, using the UnitDependencyInfo type */
 123         Hashmap *dependencies[_UNIT_DEPENDENCY_MAX];
 124
 125         /* Similar, for RequiresMountsFor= path dependencies. The key is the path, the value the UnitDependencyInfo type */
 126         Hashmap *requires_mounts_for;
 127
 128         char *description;
 129         char **documentation;
 130
 131         char *fragment_path; /* if loaded from a config file this is the primary path to it */
 132         char *source_path; /* if converted, the source file */
 133         char **dropin_paths;
 134
 135         usec_t fragment_mtime;
 136         usec_t source_mtime;
 137         usec_t dropin_mtime;
 138
 139         /* If this is a transient unit we are currently writing, this is where we are writing it to */
 140         FILE *transient_file;
 141
 142         /* If there is something to do with this unit, then this is the installed job for it */
 143         Job *job;
 144
 145         /* JOB_NOP jobs are special and can be installed without disturbing the real job. */
 146         Job *nop_job;
 147
 148         /* The slot used for watching NameOwnerChanged signals */
 149         sd_bus_slot *match_bus_slot;
 150
 151         /* References to this unit from clients */
 152         sd_bus_track *bus_track;
 153         char **deserialized_refs;
 154
 155         /* Job timeout and action to take */
 156         usec_t job_timeout;
 157         usec_t job_running_timeout;
 158         bool job_running_timeout_set:1;
 159         EmergencyAction job_timeout_action;
 160         char *job_timeout_reboot_arg;
 161
 162         /* References to this */
 163         LIST_HEAD(UnitRef, refs_by_target);
 164
 165         /* Conditions to check */
 166         LIST_HEAD(Condition, conditions);
 167         LIST_HEAD(Condition, asserts);
 168
 169         dual_timestamp condition_timestamp;
 170         dual_timestamp assert_timestamp;
 171
 172         /* Updated whenever the low-level state changes */
 173         dual_timestamp state_change_timestamp;
 174
 175         /* Updated whenever the (high-level) active state enters or leaves the active or inactive states */
 176         dual_timestamp inactive_exit_timestamp;
 177         dual_timestamp active_enter_timestamp;
 178         dual_timestamp active_exit_timestamp;
 179         dual_timestamp inactive_enter_timestamp;
 180
 181         UnitRef slice;
 182
 183         /* Per type list */
 184         LIST_FIELDS(Unit, units_by_type);
 185
 186         /* Load queue */
 187         LIST_FIELDS(Unit, load_queue);
 188
 189         /* D-Bus queue */
 190         LIST_FIELDS(Unit, dbus_queue);
 191
 192         /* Cleanup queue */
 193         LIST_FIELDS(Unit, cleanup_queue);
 194
 195         /* GC queue */
 196         LIST_FIELDS(Unit, gc_queue);
 197
 198         /* CGroup realize members queue */
 199         LIST_FIELDS(Unit, cgroup_realize_queue);
 200
 201         /* cgroup empty queue */
 202         LIST_FIELDS(Unit, cgroup_empty_queue);
 203
 204         /* cgroup OOM queue */
 205         LIST_FIELDS(Unit, cgroup_oom_queue);
 206
 207         /* Target dependencies queue */
 208         LIST_FIELDS(Unit, target_deps_queue);
 209
 210         /* Queue of units with StopWhenUnneeded set that shell be checked for clean-up. */
 211         LIST_FIELDS(Unit, stop_when_unneeded_queue);
 212
 213         /* PIDs we keep an eye on. Note that a unit might have many
 214          * more, but these are the ones we care enough about to
 215          * process SIGCHLD for */
 216         Set *pids;
 217
 218         /* Used in SIGCHLD and sd_notify() message event invocation logic to avoid that we dispatch the same event
 219          * multiple times on the same unit. */
 220         unsigned sigchldgen;
 221         unsigned notifygen;
 222
 223         /* Used during GC sweeps */
 224         unsigned gc_marker;
 225
 226         /* Error code when we didn't manage to load the unit (negative) */
 227         int load_error;
 228
 229         /* Put a ratelimit on unit starting */
 230         RateLimit start_limit;
 231         EmergencyAction start_limit_action;
 232
 233         /* What to do on failure or success */
 234         EmergencyAction success_action, failure_action;
 235         int success_action_exit_status, failure_action_exit_status;
 236         char *reboot_arg;
 237
 238         /* Make sure we never enter endless loops with the check unneeded logic, or the BindsTo= logic */
 239         RateLimit auto_stop_ratelimit;
 240
 241         /* Reference to a specific UID/GID */
 242         uid_t ref_uid;
 243         gid_t ref_gid;
 244
 245         /* Cached unit file state and preset */
 246         UnitFileState unit_file_state;
 247         int unit_file_preset;
 248
 249         /* Where the cpu.stat or cpuacct.usage was at the time the unit was started */
 250         nsec_t cpu_usage_base;
 251         nsec_t cpu_usage_last; /* the most recently read value */
 252
 253         /* The  current counter of the oom_kill field in the memory.events cgroup attribute */
 254         uint64_t oom_kill_last;
 255
 256         /* Where the io.stat data was at the time the unit was started */
 257         uint64_t io_accounting_base[_CGROUP_IO_ACCOUNTING_METRIC_MAX];
 258         uint64_t io_accounting_last[_CGROUP_IO_ACCOUNTING_METRIC_MAX]; /* the most recently read value */
 259
 260         /* Counterparts in the cgroup filesystem */
 261         char *cgroup_path;
 262         CGroupMask cgroup_realized_mask;           /* In which hierarchies does this unit's cgroup exist? (only relevant on cgroup v1) */
 263         CGroupMask cgroup_enabled_mask;            /* Which controllers are enabled (or more correctly: enabled for the children) for this unit's cgroup? (only relevant on cgroup v2) */
 264         CGroupMask cgroup_invalidated_mask;        /* A mask specifying controllers which shall be considered invalidated, and require re-realization */
 265         CGroupMask cgroup_members_mask;            /* A cache for the controllers required by all children of this cgroup (only relevant for slice units) */
 266
 267         /* Inotify watch descriptors for watching cgroup.events and memory.events on cgroupv2 */
 268         int cgroup_control_inotify_wd;
 269         int cgroup_memory_inotify_wd;
 270
 271         /* Device Controller BPF program */
 272         BPFProgram *bpf_device_control_installed;
 273
 274         /* IP BPF Firewalling/accounting */
 275         int ip_accounting_ingress_map_fd;
 276         int ip_accounting_egress_map_fd;
 277
 278         int ipv4_allow_map_fd;
 279         int ipv6_allow_map_fd;
 280         int ipv4_deny_map_fd;
 281         int ipv6_deny_map_fd;
 282
 283         BPFProgram *ip_bpf_ingress, *ip_bpf_ingress_installed;
 284         BPFProgram *ip_bpf_egress, *ip_bpf_egress_installed;
 285         Set *ip_bpf_custom_ingress;
 286         Set *ip_bpf_custom_ingress_installed;
 287         Set *ip_bpf_custom_egress;
 288         Set *ip_bpf_custom_egress_installed;
 289
 290         uint64_t ip_accounting_extra[_CGROUP_IP_ACCOUNTING_METRIC_MAX];
 291
 292         /* Low-priority event source which is used to remove watched PIDs that have gone away, and subscribe to any new
 293          * ones which might have appeared. */
 294         sd_event_source *rewatch_pids_event_source;
 295
 296         /* How to start OnFailure units */
 297         JobMode on_failure_job_mode;
 298
 299         /* Tweaking the GC logic */
 300         CollectMode collect_mode;
 301
 302         /* The current invocation ID */
 303         sd_id128_t invocation_id;
 304         char invocation_id_string[SD_ID128_STRING_MAX]; /* useful when logging */
 305
 306         /* Garbage collect us we nobody wants or requires us anymore */
 307         bool stop_when_unneeded;
 308
 309         /* Create default dependencies */
 310         bool default_dependencies;
 311
 312         /* Refuse manual starting, allow starting only indirectly via dependency. */
 313         bool refuse_manual_start;
 314
 315         /* Don't allow the user to stop this unit manually, allow stopping only indirectly via dependency. */
 316         bool refuse_manual_stop;
 317
 318         /* Allow isolation requests */
 319         bool allow_isolate;
 320
 321         /* Ignore this unit when isolating */
 322         bool ignore_on_isolate;
 323
 324         /* Did the last condition check succeed? */
 325         bool condition_result;
 326         bool assert_result;
 327
 328         /* Is this a transient unit? */
 329         bool transient;
 330
 331         /* Is this a unit that is always running and cannot be stopped? */
 332         bool perpetual;
 333
 334         /* Booleans indicating membership of this unit in the various queues */
 335         bool in_load_queue:1;
 336         bool in_dbus_queue:1;
 337         bool in_cleanup_queue:1;
 338         bool in_gc_queue:1;
 339         bool in_cgroup_realize_queue:1;
 340         bool in_cgroup_empty_queue:1;
 341         bool in_cgroup_oom_queue:1;
 342         bool in_target_deps_queue:1;
 343         bool in_stop_when_unneeded_queue:1;
 344
 345         bool sent_dbus_new_signal:1;
 346
 347         bool in_audit:1;
 348         bool on_console:1;
 349
 350         bool cgroup_realized:1;
 351         bool cgroup_members_mask_valid:1;
 352
 353         /* Reset cgroup accounting next time we fork something off */
 354         bool reset_accounting:1;
 355
 356         bool start_limit_hit:1;
 357
 358         /* Did we already invoke unit_coldplug() for this unit? */
 359         bool coldplugged:1;
 360
 361         /* For transient units: whether to add a bus track reference after creating the unit */
 362         bool bus_track_add:1;
 363
 364         /* Remember which unit state files we created */
 365         bool exported_invocation_id:1;
 366         bool exported_log_level_max:1;
 367         bool exported_log_extra_fields:1;
 368         bool exported_log_rate_limit_interval:1;
 369         bool exported_log_rate_limit_burst:1;
 370
 371         /* Whether we warned about clamping the CPU quota period */
 372         bool warned_clamping_cpu_quota_period:1;
 373
 374         /* When writing transient unit files, stores which section we stored last. If < 0, we didn't write any yet. If
 375          * == 0 we are in the [Unit] section, if > 0 we are in the unit type-specific section. */
 376         signed int last_section_private:2;
 377 } Unit;
 378
 379 typedef struct UnitStatusMessageFormats {
 380         const char *starting_stopping[2];
 381         const char *finished_start_job[_JOB_RESULT_MAX];
 382         const char *finished_stop_job[_JOB_RESULT_MAX];
 383 } UnitStatusMessageFormats;
 384
 385 /* Flags used when writing drop-in files or transient unit files */
 386 typedef enum UnitWriteFlags {
 387         /* Write a runtime unit file or drop-in (i.e. one below /run) */
 388         UNIT_RUNTIME           = 1 << 0,
 389
 390         /* Write a persistent drop-in (i.e. one below /etc) */
 391         UNIT_PERSISTENT        = 1 << 1,
 392
 393         /* Place this item in the per-unit-type private section, instead of [Unit] */
 394         UNIT_PRIVATE           = 1 << 2,
 395
 396         /* Apply specifier escaping before writing */
 397         UNIT_ESCAPE_SPECIFIERS = 1 << 3,
 398
 399         /* Apply C escaping before writing */
 400         UNIT_ESCAPE_C          = 1 << 4,
 401 } UnitWriteFlags;
 402
 403 /* Returns true if neither persistent, nor runtime storage is requested, i.e. this is a check invocation only */
 404 static inline bool UNIT_WRITE_FLAGS_NOOP(UnitWriteFlags flags) {
 405         return (flags & (UNIT_RUNTIME|UNIT_PERSISTENT)) == 0;
 406 }
 407
 408 #include "kill.h"
 409
 410 typedef struct UnitVTable {
 411         /* How much memory does an object of this unit type need */
 412         size_t object_size;
 413
 414         /* If greater than 0, the offset into the object where
 415          * ExecContext is found, if the unit type has that */
 416         size_t exec_context_offset;
 417
 418         /* If greater than 0, the offset into the object where
 419          * CGroupContext is found, if the unit type has that */
 420         size_t cgroup_context_offset;
 421
 422         /* If greater than 0, the offset into the object where
 423          * KillContext is found, if the unit type has that */
 424         size_t kill_context_offset;
 425
 426         /* If greater than 0, the offset into the object where the
 427          * pointer to ExecRuntime is found, if the unit type has
 428          * that */
 429         size_t exec_runtime_offset;
 430
 431         /* If greater than 0, the offset into the object where the pointer to DynamicCreds is found, if the unit type
 432          * has that. */
 433         size_t dynamic_creds_offset;
 434
 435         /* The name of the configuration file section with the private settings of this unit */
 436         const char *private_section;
 437
 438         /* Config file sections this unit type understands, separated
 439          * by NUL chars */
 440         const char *sections;
 441
 442         /* This should reset all type-specific variables. This should
 443          * not allocate memory, and is called with zero-initialized
 444          * data. It should hence only initialize variables that need
 445          * to be set != 0. */
 446         void (*init)(Unit *u);
 447
 448         /* This should free all type-specific variables. It should be
 449          * idempotent. */
 450         void (*done)(Unit *u);
 451
 452         /* Actually load data from disk. This may fail, and should set
 453          * load_state to UNIT_LOADED, UNIT_MERGED or leave it at
 454          * UNIT_STUB if no configuration could be found. */
 455         int (*load)(Unit *u);
 456
 457         /* During deserialization we only record the intended state to return to. With coldplug() we actually put the
 458          * deserialized state in effect. This is where unit_notify() should be called to start things up. Note that
 459          * this callback is invoked *before* we leave the reloading state of the manager, i.e. *before* we consider the
 460          * reloading to be complete. Thus, this callback should just restore the exact same state for any unit that was
 461          * in effect before the reload, i.e. units should not catch up with changes happened during the reload. That's
 462          * what catchup() below is for. */
 463         int (*coldplug)(Unit *u);
 464
 465         /* This is called shortly after all units' coldplug() call was invoked, and *after* the manager left the
 466          * reloading state. It's supposed to catch up with state changes due to external events we missed so far (for
 467          * example because they took place while we were reloading/reexecing) */
 468         void (*catchup)(Unit *u);
 469
 470         void (*dump)(Unit *u, FILE *f, const char *prefix);
 471
 472         int (*start)(Unit *u);
 473         int (*stop)(Unit *u);
 474         int (*reload)(Unit *u);
 475
 476         int (*kill)(Unit *u, KillWho w, int signo, sd_bus_error *error);
 477
 478         /* Clear out the various runtime/state/cache/logs/configuration data */
 479         int (*clean)(Unit *u, ExecCleanMask m);
 480
 481         /* Return which kind of data can be cleaned */
 482         int (*can_clean)(Unit *u, ExecCleanMask *ret);
 483
 484         bool (*can_reload)(Unit *u);
 485
 486         /* Write all data that cannot be restored from other sources
 487          * away using unit_serialize_item() */
 488         int (*serialize)(Unit *u, FILE *f, FDSet *fds);
 489
 490         /* Restore one item from the serialization */
 491         int (*deserialize_item)(Unit *u, const char *key, const char *data, FDSet *fds);
 492
 493         /* Try to match up fds with what we need for this unit */
 494         void (*distribute_fds)(Unit *u, FDSet *fds);
 495
 496         /* Boils down the more complex internal state of this unit to
 497          * a simpler one that the engine can understand */
 498         UnitActiveState (*active_state)(Unit *u);
 499
 500         /* Returns the substate specific to this unit type as
 501          * string. This is purely information so that we can give the
 502          * user a more fine grained explanation in which actual state a
 503          * unit is in. */
 504         const char* (*sub_state_to_string)(Unit *u);
 505
 506         /* Additionally to UnitActiveState determine whether unit is to be restarted. */
 507         bool (*will_restart)(Unit *u);
 508
 509         /* Return false when there is a reason to prevent this unit from being gc'ed
 510          * even though nothing references it and it isn't active in any way. */
 511         bool (*may_gc)(Unit *u);
 512
 513         /* When the unit is not running and no job for it queued we shall release its runtime resources */
 514         void (*release_resources)(Unit *u);
 515
 516         /* Invoked on every child that died */
 517         void (*sigchld_event)(Unit *u, pid_t pid, int code, int status);
 518
 519         /* Reset failed state if we are in failed state */
 520         void (*reset_failed)(Unit *u);
 521
 522         /* Called whenever any of the cgroups this unit watches for ran empty */
 523         void (*notify_cgroup_empty)(Unit *u);
 524
 525         /* Called whenever an OOM kill event on this unit was seen */
 526         void (*notify_cgroup_oom)(Unit *u);
 527
 528         /* Called whenever a process of this unit sends us a message */
 529         void (*notify_message)(Unit *u, const struct ucred *ucred, char **tags, FDSet *fds);
 530
 531         /* Called whenever a name this Unit registered for comes or goes away. */
 532         void (*bus_name_owner_change)(Unit *u, const char *name, const char *old_owner, const char *new_owner);
 533
 534         /* Called for each property that is being set */
 535         int (*bus_set_property)(Unit *u, const char *name, sd_bus_message *message, UnitWriteFlags flags, sd_bus_error *error);
 536
 537         /* Called after at least one property got changed to apply the necessary change */
 538         int (*bus_commit_properties)(Unit *u);
 539
 540         /* Return the unit this unit is following */
 541         Unit *(*following)(Unit *u);
 542
 543         /* Return the set of units that are following each other */
 544         int (*following_set)(Unit *u, Set **s);
 545
 546         /* Invoked each time a unit this unit is triggering changes
 547          * state or gains/loses a job */
 548         void (*trigger_notify)(Unit *u, Unit *trigger);
 549
 550         /* Called whenever CLOCK_REALTIME made a jump */
 551         void (*time_change)(Unit *u);
 552
 553         /* Called whenever /etc/localtime was modified */
 554         void (*timezone_change)(Unit *u);
 555
 556         /* Returns the next timeout of a unit */
 557         int (*get_timeout)(Unit *u, usec_t *timeout);
 558
 559         /* Returns the main PID if there is any defined, or 0. */
 560         pid_t (*main_pid)(Unit *u);
 561
 562         /* Returns the main PID if there is any defined, or 0. */
 563         pid_t (*control_pid)(Unit *u);
 564
 565         /* Returns true if the unit currently needs access to the console */
 566         bool (*needs_console)(Unit *u);
 567
 568         /* Returns the exit status to propagate in case of FailureAction=exit/SuccessAction=exit; usually returns the
 569          * exit code of the "main" process of the service or similar. */
 570         int (*exit_status)(Unit *u);
 571
 572         /* Like the enumerate() callback further down, but only enumerates the perpetual units, i.e. all units that
 573          * unconditionally exist and are always active. The main reason to keep both enumeration functions separate is
 574          * philosophical: the state of perpetual units should be put in place by coldplug(), while the state of those
 575          * discovered through regular enumeration should be put in place by catchup(), see below. */
 576         void (*enumerate_perpetual)(Manager *m);
 577
 578         /* This is called for each unit type and should be used to enumerate units already existing in the system
 579          * internally and load them. However, everything that is loaded here should still stay in inactive state. It is
 580          * the job of the catchup() call above to put the units into the discovered state. */
 581         void (*enumerate)(Manager *m);
 582
 583         /* Type specific cleanups. */
 584         void (*shutdown)(Manager *m);
 585
 586         /* If this function is set and return false all jobs for units
 587          * of this type will immediately fail. */
 588         bool (*supported)(void);
 589
 590         /* The bus vtable */
 591         const sd_bus_vtable *bus_vtable;
 592
 593         /* The strings to print in status messages */
 594         UnitStatusMessageFormats status_message_formats;
 595
 596         /* True if transient units of this type are OK */
 597         bool can_transient:1;
 598
 599         /* True if cgroup delegation is permissible */
 600         bool can_delegate:1;
 601
 602         /* True if units of this type shall be startable only once and then never again */
 603         bool once_only:1;
 604
 605         /* True if queued jobs of this type should be GC'ed if no other job needs them anymore */
 606         bool gc_jobs:1;
 607 } UnitVTable;
 608
 609 extern const UnitVTable * const unit_vtable[_UNIT_TYPE_MAX];
 610
 611 static inline const UnitVTable* UNIT_VTABLE(Unit *u) {
 612         return unit_vtable[u->type];
 613 }
 614
 615 /* For casting a unit into the various unit types */
 616 #define DEFINE_CAST(UPPERCASE, MixedCase)                               \
 617         static inline MixedCase* UPPERCASE(Unit *u) {                   \
 618                 if (_unlikely_(!u || u->type != UNIT_##UPPERCASE))      \
 619                         return NULL;                                    \
 620                                                                         \
 621                 return (MixedCase*) u;                                  \
 622         }
 623
 624 /* For casting the various unit types into a unit */
 625 #define UNIT(u)                                         \
 626         ({                                              \
 627                 typeof(u) _u_ = (u);                    \
 628                 Unit *_w_ = _u_ ? &(_u_)->meta : NULL;  \
 629                 _w_;                                    \
 630         })
 631
 632 #define UNIT_HAS_EXEC_CONTEXT(u) (UNIT_VTABLE(u)->exec_context_offset > 0)
 633 #define UNIT_HAS_CGROUP_CONTEXT(u) (UNIT_VTABLE(u)->cgroup_context_offset > 0)
 634 #define UNIT_HAS_KILL_CONTEXT(u) (UNIT_VTABLE(u)->kill_context_offset > 0)
 635
 636 static inline Unit* UNIT_TRIGGER(Unit *u) {
 637         return hashmap_first_key(u->dependencies[UNIT_TRIGGERS]);
 638 }
 639
 640 Unit *unit_new(Manager *m, size_t size);
 641 void unit_free(Unit *u);
 642 DEFINE_TRIVIAL_CLEANUP_FUNC(Unit *, unit_free);
 643
 644 int unit_new_for_name(Manager *m, size_t size, const char *name, Unit **ret);
 645 int unit_add_name(Unit *u, const char *name);
 646
 647 int unit_add_dependency(Unit *u, UnitDependency d, Unit *other, bool add_reference, UnitDependencyMask mask);
 648 int unit_add_two_dependencies(Unit *u, UnitDependency d, UnitDependency e, Unit *other, bool add_reference, UnitDependencyMask mask);
 649
 650 int unit_add_dependency_by_name(Unit *u, UnitDependency d, const char *name, bool add_reference, UnitDependencyMask mask);
 651 int unit_add_two_dependencies_by_name(Unit *u, UnitDependency d, UnitDependency e, const char *name, bool add_reference, UnitDependencyMask mask);
 652
 653 int unit_add_exec_dependencies(Unit *u, ExecContext *c);
 654
 655 int unit_choose_id(Unit *u, const char *name);
 656 int unit_set_description(Unit *u, const char *description);
 657
 658 bool unit_may_gc(Unit *u);
 659
 660 void unit_add_to_load_queue(Unit *u);
 661 void unit_add_to_dbus_queue(Unit *u);
 662 void unit_add_to_cleanup_queue(Unit *u);
 663 void unit_add_to_gc_queue(Unit *u);
 664 void unit_add_to_target_deps_queue(Unit *u);
 665 void unit_submit_to_stop_when_unneeded_queue(Unit *u);
 666
 667 int unit_merge(Unit *u, Unit *other);
 668 int unit_merge_by_name(Unit *u, const char *other);
 669
 670 Unit *unit_follow_merge(Unit *u) _pure_;
 671
 672 int unit_load_fragment_and_dropin(Unit *u);
 673 int unit_load_fragment_and_dropin_optional(Unit *u);
 674 int unit_load(Unit *unit);
 675
 676 int unit_set_slice(Unit *u, Unit *slice);
 677 int unit_set_default_slice(Unit *u);
 678
 679 const char *unit_description(Unit *u) _pure_;
 680 const char *unit_status_string(Unit *u) _pure_;
 681
 682 bool unit_has_name(const Unit *u, const char *name);
 683
 684 UnitActiveState unit_active_state(Unit *u);
 685
 686 const char* unit_sub_state_to_string(Unit *u);
 687
 688 void unit_dump(Unit *u, FILE *f, const char *prefix);
 689
 690 bool unit_can_reload(Unit *u) _pure_;
 691 bool unit_can_start(Unit *u) _pure_;
 692 bool unit_can_stop(Unit *u) _pure_;
 693 bool unit_can_isolate(Unit *u) _pure_;
 694
 695 int unit_start(Unit *u);
 696 int unit_stop(Unit *u);
 697 int unit_reload(Unit *u);
 698
 699 int unit_kill(Unit *u, KillWho w, int signo, sd_bus_error *error);
 700 int unit_kill_common(Unit *u, KillWho who, int signo, pid_t main_pid, pid_t control_pid, sd_bus_error *error);
 701
 702 typedef enum UnitNotifyFlags {
 703         UNIT_NOTIFY_RELOAD_FAILURE    = 1 << 0,
 704         UNIT_NOTIFY_WILL_AUTO_RESTART = 1 << 1,
 705         UNIT_NOTIFY_SKIP_CONDITION    = 1 << 2,
 706 } UnitNotifyFlags;
 707
 708 void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns, UnitNotifyFlags flags);
 709
 710 int unit_watch_pid(Unit *u, pid_t pid, bool exclusive);
 711 void unit_unwatch_pid(Unit *u, pid_t pid);
 712 void unit_unwatch_all_pids(Unit *u);
 713
 714 int unit_enqueue_rewatch_pids(Unit *u);
 715 void unit_dequeue_rewatch_pids(Unit *u);
 716
 717 int unit_install_bus_match(Unit *u, sd_bus *bus, const char *name);
 718 int unit_watch_bus_name(Unit *u, const char *name);
 719 void unit_unwatch_bus_name(Unit *u, const char *name);
 720
 721 bool unit_job_is_applicable(Unit *u, JobType j);
 722
 723 int set_unit_path(const char *p);
 724
 725 char *unit_dbus_path(Unit *u);
 726 char *unit_dbus_path_invocation_id(Unit *u);
 727
 728 int unit_load_related_unit(Unit *u, const char *type, Unit **_found);
 729
 730 bool unit_can_serialize(Unit *u) _pure_;
 731
 732 int unit_serialize(Unit *u, FILE *f, FDSet *fds, bool serialize_jobs);
 733 int unit_deserialize(Unit *u, FILE *f, FDSet *fds);
 734 int unit_deserialize_skip(FILE *f);
 735
 736 int unit_add_node_dependency(Unit *u, const char *what, bool wants, UnitDependency d, UnitDependencyMask mask);
 737
 738 int unit_coldplug(Unit *u);
 739 void unit_catchup(Unit *u);
 740
 741 void unit_status_printf(Unit *u, const char *status, const char *unit_status_msg_format) _printf_(3, 0);
 742
 743 bool unit_need_daemon_reload(Unit *u);
 744
 745 void unit_reset_failed(Unit *u);
 746
 747 Unit *unit_following(Unit *u);
 748 int unit_following_set(Unit *u, Set **s);
 749
 750 const char *unit_slice_name(Unit *u);
 751
 752 bool unit_stop_pending(Unit *u) _pure_;
 753 bool unit_inactive_or_pending(Unit *u) _pure_;
 754 bool unit_active_or_pending(Unit *u);
 755 bool unit_will_restart(Unit *u);
 756
 757 int unit_add_default_target_dependency(Unit *u, Unit *target);
 758
 759 void unit_start_on_failure(Unit *u);
 760 void unit_trigger_notify(Unit *u);
 761
 762 UnitFileState unit_get_unit_file_state(Unit *u);
 763 int unit_get_unit_file_preset(Unit *u);
 764
 765 Unit* unit_ref_set(UnitRef *ref, Unit *source, Unit *target);
 766 void unit_ref_unset(UnitRef *ref);
 767
 768 #define UNIT_DEREF(ref) ((ref).target)
 769 #define UNIT_ISSET(ref) (!!(ref).target)
 770
 771 int unit_patch_contexts(Unit *u);
 772
 773 ExecContext *unit_get_exec_context(Unit *u) _pure_;
 774 KillContext *unit_get_kill_context(Unit *u) _pure_;
 775 CGroupContext *unit_get_cgroup_context(Unit *u) _pure_;
 776
 777 ExecRuntime *unit_get_exec_runtime(Unit *u) _pure_;
 778
 779 int unit_setup_exec_runtime(Unit *u);
 780 int unit_setup_dynamic_creds(Unit *u);
 781
 782 char* unit_escape_setting(const char *s, UnitWriteFlags flags, char **buf);
 783 char* unit_concat_strv(char **l, UnitWriteFlags flags);
 784
 785 int unit_write_setting(Unit *u, UnitWriteFlags flags, const char *name, const char *data);
 786 int unit_write_settingf(Unit *u, UnitWriteFlags mode, const char *name, const char *format, ...) _printf_(4,5);
 787
 788 int unit_kill_context(Unit *u, KillContext *c, KillOperation k, pid_t main_pid, pid_t control_pid, bool main_pid_alien);
 789
 790 int unit_make_transient(Unit *u);
 791
 792 int unit_require_mounts_for(Unit *u, const char *path, UnitDependencyMask mask);
 793
 794 bool unit_type_supported(UnitType t);
 795
 796 bool unit_is_pristine(Unit *u);
 797
 798 bool unit_is_unneeded(Unit *u);
 799
 800 pid_t unit_control_pid(Unit *u);
 801 pid_t unit_main_pid(Unit *u);
 802
 803 static inline bool unit_supported(Unit *u) {
 804         return unit_type_supported(u->type);
 805 }
 806
 807 void unit_warn_if_dir_nonempty(Unit *u, const char* where);
 808 int unit_fail_if_noncanonical(Unit *u, const char* where);
 809
 810 int unit_test_start_limit(Unit *u);
 811
 812 void unit_unref_uid(Unit *u, bool destroy_now);
 813 int unit_ref_uid(Unit *u, uid_t uid, bool clean_ipc);
 814
 815 void unit_unref_gid(Unit *u, bool destroy_now);
 816 int unit_ref_gid(Unit *u, gid_t gid, bool clean_ipc);
 817
 818 int unit_ref_uid_gid(Unit *u, uid_t uid, gid_t gid);
 819 void unit_unref_uid_gid(Unit *u, bool destroy_now);
 820
 821 void unit_notify_user_lookup(Unit *u, uid_t uid, gid_t gid);
 822
 823 int unit_set_invocation_id(Unit *u, sd_id128_t id);
 824 int unit_acquire_invocation_id(Unit *u);
 825
 826 bool unit_shall_confirm_spawn(Unit *u);
 827
 828 int unit_set_exec_params(Unit *s, ExecParameters *p);
 829
 830 int unit_fork_helper_process(Unit *u, const char *name, pid_t *ret);
 831
 832 void unit_remove_dependencies(Unit *u, UnitDependencyMask mask);
 833
 834 void unit_export_state_files(Unit *u);
 835 void unit_unlink_state_files(Unit *u);
 836
 837 int unit_prepare_exec(Unit *u);
 838
 839 int unit_warn_leftover_processes(Unit *u);
 840
 841 bool unit_needs_console(Unit *u);
 842
 843 const char *unit_label_path(Unit *u);
 844
 845 int unit_pid_attachable(Unit *unit, pid_t pid, sd_bus_error *error);
 846
 847 /* unit_log_skip is for cases like ExecCondition= where a unit is considered "done"
 848  * after some execution, rather than succeeded or failed. */
 849 void unit_log_skip(Unit *u, const char *result);
 850 void unit_log_success(Unit *u);
 851 void unit_log_failure(Unit *u, const char *result);
 852 static inline void unit_log_result(Unit *u, bool success, const char *result) {
 853         if (success)
 854                 unit_log_success(u);
 855         else
 856                 unit_log_failure(u, result);
 857 }
 858
 859 void unit_log_process_exit(Unit *u, int level, const char *kind, const char *command, int code, int status);
 860
 861 int unit_exit_status(Unit *u);
 862 int unit_success_action_exit_status(Unit *u);
 863 int unit_failure_action_exit_status(Unit *u);
 864
 865 int unit_test_trigger_loaded(Unit *u);
 866
 867 int unit_clean(Unit *u, ExecCleanMask mask);
 868 int unit_can_clean(Unit *u, ExecCleanMask *ret_mask);
 869
 870 /* Macros which append UNIT= or USER_UNIT= to the message */
 871
 872 #define log_unit_full(unit, level, error, ...)                          \
 873         ({                                                              \
 874                 const Unit *_u = (unit);                                \
 875                 _u ? log_object_internal(level, error, PROJECT_FILE, __LINE__, __func__, _u->manager->unit_log_field, _u->id, _u->manager->invocation_log_field, _u->invocation_id_string, ##__VA_ARGS__) : \
 876                         log_internal(level, error, PROJECT_FILE, __LINE__, __func__, ##__VA_ARGS__); \
 877         })
 878
 879 #define log_unit_debug(unit, ...)   log_unit_full(unit, LOG_DEBUG, 0, ##__VA_ARGS__)
 880 #define log_unit_info(unit, ...)    log_unit_full(unit, LOG_INFO, 0, ##__VA_ARGS__)
 881 #define log_unit_notice(unit, ...)  log_unit_full(unit, LOG_NOTICE, 0, ##__VA_ARGS__)
 882 #define log_unit_warning(unit, ...) log_unit_full(unit, LOG_WARNING, 0, ##__VA_ARGS__)
 883 #define log_unit_error(unit, ...)   log_unit_full(unit, LOG_ERR, 0, ##__VA_ARGS__)
 884
 885 #define log_unit_debug_errno(unit, error, ...)   log_unit_full(unit, LOG_DEBUG, error, ##__VA_ARGS__)
 886 #define log_unit_info_errno(unit, error, ...)    log_unit_full(unit, LOG_INFO, error, ##__VA_ARGS__)
 887 #define log_unit_notice_errno(unit, error, ...)  log_unit_full(unit, LOG_NOTICE, error, ##__VA_ARGS__)
 888 #define log_unit_warning_errno(unit, error, ...) log_unit_full(unit, LOG_WARNING, error, ##__VA_ARGS__)
 889 #define log_unit_error_errno(unit, error, ...)   log_unit_full(unit, LOG_ERR, error, ##__VA_ARGS__)
 890
 891 #define LOG_UNIT_MESSAGE(unit, fmt, ...) "MESSAGE=%s: " fmt, (unit)->id, ##__VA_ARGS__
 892 #define LOG_UNIT_ID(unit) (unit)->manager->unit_log_format_string, (unit)->id
 893 #define LOG_UNIT_INVOCATION_ID(unit) (unit)->manager->invocation_log_format_string, (unit)->invocation_id_string
 894
 895 const char* collect_mode_to_string(CollectMode m) _const_;
 896 CollectMode collect_mode_from_string(const char *s) _pure_;