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+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+#pragma once
+
+#include <stdbool.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "bpf-program.h"
+#include "condition.h"
+#include "emergency-action.h"
+#include "list.h"
+#include "show-status.h"
+#include "set.h"
+#include "unit-file.h"
+#include "cgroup.h"
+
+typedef struct UnitRef UnitRef;
+
+typedef enum KillOperation {
+ KILL_TERMINATE,
+ KILL_TERMINATE_AND_LOG,
+ KILL_RESTART,
+ KILL_KILL,
+ KILL_WATCHDOG,
+ _KILL_OPERATION_MAX,
+ _KILL_OPERATION_INVALID = -1
+} KillOperation;
+
+typedef enum CollectMode {
+ COLLECT_INACTIVE,
+ COLLECT_INACTIVE_OR_FAILED,
+ _COLLECT_MODE_MAX,
+ _COLLECT_MODE_INVALID = -1,
+} CollectMode;
+
+static inline bool UNIT_IS_ACTIVE_OR_RELOADING(UnitActiveState t) {
+ return IN_SET(t, UNIT_ACTIVE, UNIT_RELOADING);
+}
+
+static inline bool UNIT_IS_ACTIVE_OR_ACTIVATING(UnitActiveState t) {
+ return IN_SET(t, UNIT_ACTIVE, UNIT_ACTIVATING, UNIT_RELOADING);
+}
+
+static inline bool UNIT_IS_INACTIVE_OR_DEACTIVATING(UnitActiveState t) {
+ return IN_SET(t, UNIT_INACTIVE, UNIT_FAILED, UNIT_DEACTIVATING);
+}
+
+static inline bool UNIT_IS_INACTIVE_OR_FAILED(UnitActiveState t) {
+ return IN_SET(t, UNIT_INACTIVE, UNIT_FAILED);
+}
+
+static inline bool UNIT_IS_LOAD_COMPLETE(UnitLoadState t) {
+ return t >= 0 && t < _UNIT_LOAD_STATE_MAX && t != UNIT_STUB && t != UNIT_MERGED;
+}
+
+/* Stores the 'reason' a dependency was created as a bit mask, i.e. due to which configuration source it came to be. We
+ * use this so that we can selectively flush out parts of dependencies again. Note that the same dependency might be
+ * created as a result of multiple "reasons", hence the bitmask. */
+typedef enum UnitDependencyMask {
+ /* Configured directly by the unit file, .wants/.requires symlink or drop-in, or as an immediate result of a
+ * non-dependency option configured that way. */
+ UNIT_DEPENDENCY_FILE = 1 << 0,
+
+ /* As unconditional implicit dependency (not affected by unit configuration — except by the unit name and
+ * type) */
+ UNIT_DEPENDENCY_IMPLICIT = 1 << 1,
+
+ /* A dependency effected by DefaultDependencies=yes. Note that dependencies marked this way are conceptually
+ * just a subset of UNIT_DEPENDENCY_FILE, as DefaultDependencies= is itself a unit file setting that can only
+ * be set in unit files. We make this two separate bits only to help debugging how dependencies came to be. */
+ UNIT_DEPENDENCY_DEFAULT = 1 << 2,
+
+ /* A dependency created from udev rules */
+ UNIT_DEPENDENCY_UDEV = 1 << 3,
+
+ /* A dependency created because of some unit's RequiresMountsFor= setting */
+ UNIT_DEPENDENCY_PATH = 1 << 4,
+
+ /* A dependency created because of data read from /proc/self/mountinfo and no other configuration source */
+ UNIT_DEPENDENCY_MOUNTINFO_IMPLICIT = 1 << 5,
+
+ /* A dependency created because of data read from /proc/self/mountinfo, but conditionalized by
+ * DefaultDependencies= and thus also involving configuration from UNIT_DEPENDENCY_FILE sources */
+ UNIT_DEPENDENCY_MOUNTINFO_DEFAULT = 1 << 6,
+
+ /* A dependency created because of data read from /proc/swaps and no other configuration source */
+ UNIT_DEPENDENCY_PROC_SWAP = 1 << 7,
+
+ _UNIT_DEPENDENCY_MASK_FULL = (1 << 8) - 1,
+} UnitDependencyMask;
+
+/* The Unit's dependencies[] hashmaps use this structure as value. It has the same size as a void pointer, and thus can
+ * be stored directly as hashmap value, without any indirection. Note that this stores two masks, as both the origin
+ * and the destination of a dependency might have created it. */
+typedef union UnitDependencyInfo {
+ void *data;
+ struct {
+ UnitDependencyMask origin_mask:16;
+ UnitDependencyMask destination_mask:16;
+ } _packed_;
+} UnitDependencyInfo;
+
+#include "job.h"
+
+struct UnitRef {
+ /* Keeps tracks of references to a unit. This is useful so
+ * that we can merge two units if necessary and correct all
+ * references to them */
+
+ Unit *source, *target;
+ LIST_FIELDS(UnitRef, refs_by_target);
+};
+
+typedef struct Unit {
+ Manager *manager;
+
+ UnitType type;
+ UnitLoadState load_state;
+ Unit *merged_into;
+
+ FreezerState freezer_state;
+ sd_bus_message *pending_freezer_message;
+
+ char *id; /* The one special name that we use for identification */
+ char *instance;
+
+ Set *aliases; /* All the other names. */
+
+ /* For each dependency type we maintain a Hashmap whose key is the Unit* object, and the value encodes why the
+ * dependency exists, using the UnitDependencyInfo type */
+ Hashmap *dependencies[_UNIT_DEPENDENCY_MAX];
+
+ /* Similar, for RequiresMountsFor= path dependencies. The key is the path, the value the UnitDependencyInfo type */
+ Hashmap *requires_mounts_for;
+
+ char *description;
+ char **documentation;
+
+ char *fragment_path; /* if loaded from a config file this is the primary path to it */
+ char *source_path; /* if converted, the source file */
+ char **dropin_paths;
+
+ usec_t fragment_not_found_timestamp_hash;
+ usec_t fragment_mtime;
+ usec_t source_mtime;
+ usec_t dropin_mtime;
+
+ /* If this is a transient unit we are currently writing, this is where we are writing it to */
+ FILE *transient_file;
+
+ /* If there is something to do with this unit, then this is the installed job for it */
+ Job *job;
+
+ /* JOB_NOP jobs are special and can be installed without disturbing the real job. */
+ Job *nop_job;
+
+ /* The slot used for watching NameOwnerChanged signals */
+ sd_bus_slot *match_bus_slot;
+ sd_bus_slot *get_name_owner_slot;
+
+ /* References to this unit from clients */
+ sd_bus_track *bus_track;
+ char **deserialized_refs;
+
+ /* Job timeout and action to take */
+ usec_t job_timeout;
+ usec_t job_running_timeout;
+ bool job_running_timeout_set:1;
+ EmergencyAction job_timeout_action;
+ char *job_timeout_reboot_arg;
+
+ /* References to this */
+ LIST_HEAD(UnitRef, refs_by_target);
+
+ /* Conditions to check */
+ LIST_HEAD(Condition, conditions);
+ LIST_HEAD(Condition, asserts);
+
+ dual_timestamp condition_timestamp;
+ dual_timestamp assert_timestamp;
+
+ /* Updated whenever the low-level state changes */
+ dual_timestamp state_change_timestamp;
+
+ /* Updated whenever the (high-level) active state enters or leaves the active or inactive states */
+ dual_timestamp inactive_exit_timestamp;
+ dual_timestamp active_enter_timestamp;
+ dual_timestamp active_exit_timestamp;
+ dual_timestamp inactive_enter_timestamp;
+
+ UnitRef slice;
+
+ /* Per type list */
+ LIST_FIELDS(Unit, units_by_type);
+
+ /* Load queue */
+ LIST_FIELDS(Unit, load_queue);
+
+ /* D-Bus queue */
+ LIST_FIELDS(Unit, dbus_queue);
+
+ /* Cleanup queue */
+ LIST_FIELDS(Unit, cleanup_queue);
+
+ /* GC queue */
+ LIST_FIELDS(Unit, gc_queue);
+
+ /* CGroup realize members queue */
+ LIST_FIELDS(Unit, cgroup_realize_queue);
+
+ /* cgroup empty queue */
+ LIST_FIELDS(Unit, cgroup_empty_queue);
+
+ /* cgroup OOM queue */
+ LIST_FIELDS(Unit, cgroup_oom_queue);
+
+ /* Target dependencies queue */
+ LIST_FIELDS(Unit, target_deps_queue);
+
+ /* Queue of units with StopWhenUnneeded set that shell be checked for clean-up. */
+ LIST_FIELDS(Unit, stop_when_unneeded_queue);
+
+ /* PIDs we keep an eye on. Note that a unit might have many
+ * more, but these are the ones we care enough about to
+ * process SIGCHLD for */
+ Set *pids;
+
+ /* Used in SIGCHLD and sd_notify() message event invocation logic to avoid that we dispatch the same event
+ * multiple times on the same unit. */
+ unsigned sigchldgen;
+ unsigned notifygen;
+
+ /* Used during GC sweeps */
+ unsigned gc_marker;
+
+ /* Error code when we didn't manage to load the unit (negative) */
+ int load_error;
+
+ /* Put a ratelimit on unit starting */
+ RateLimit start_ratelimit;
+ EmergencyAction start_limit_action;
+
+ /* What to do on failure or success */
+ EmergencyAction success_action, failure_action;
+ int success_action_exit_status, failure_action_exit_status;
+ char *reboot_arg;
+
+ /* Make sure we never enter endless loops with the check unneeded logic, or the BindsTo= logic */
+ RateLimit auto_stop_ratelimit;
+
+ /* Reference to a specific UID/GID */
+ uid_t ref_uid;
+ gid_t ref_gid;
+
+ /* Cached unit file state and preset */
+ UnitFileState unit_file_state;
+ int unit_file_preset;
+
+ /* Where the cpu.stat or cpuacct.usage was at the time the unit was started */
+ nsec_t cpu_usage_base;
+ nsec_t cpu_usage_last; /* the most recently read value */
+
+ /* The current counter of processes sent SIGKILL by systemd-oomd */
+ uint64_t managed_oom_kill_last;
+
+ /* The current counter of the oom_kill field in the memory.events cgroup attribute */
+ uint64_t oom_kill_last;
+
+ /* Where the io.stat data was at the time the unit was started */
+ uint64_t io_accounting_base[_CGROUP_IO_ACCOUNTING_METRIC_MAX];
+ uint64_t io_accounting_last[_CGROUP_IO_ACCOUNTING_METRIC_MAX]; /* the most recently read value */
+
+ /* Counterparts in the cgroup filesystem */
+ char *cgroup_path;
+ CGroupMask cgroup_realized_mask; /* In which hierarchies does this unit's cgroup exist? (only relevant on cgroup v1) */
+ 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) */
+ CGroupMask cgroup_invalidated_mask; /* A mask specifying controllers which shall be considered invalidated, and require re-realization */
+ CGroupMask cgroup_members_mask; /* A cache for the controllers required by all children of this cgroup (only relevant for slice units) */
+
+ /* Inotify watch descriptors for watching cgroup.events and memory.events on cgroupv2 */
+ int cgroup_control_inotify_wd;
+ int cgroup_memory_inotify_wd;
+
+ /* Device Controller BPF program */
+ BPFProgram *bpf_device_control_installed;
+
+ /* IP BPF Firewalling/accounting */
+ int ip_accounting_ingress_map_fd;
+ int ip_accounting_egress_map_fd;
+
+ int ipv4_allow_map_fd;
+ int ipv6_allow_map_fd;
+ int ipv4_deny_map_fd;
+ int ipv6_deny_map_fd;
+
+ BPFProgram *ip_bpf_ingress, *ip_bpf_ingress_installed;
+ BPFProgram *ip_bpf_egress, *ip_bpf_egress_installed;
+ Set *ip_bpf_custom_ingress;
+ Set *ip_bpf_custom_ingress_installed;
+ Set *ip_bpf_custom_egress;
+ Set *ip_bpf_custom_egress_installed;
+
+ uint64_t ip_accounting_extra[_CGROUP_IP_ACCOUNTING_METRIC_MAX];
+
+ /* Low-priority event source which is used to remove watched PIDs that have gone away, and subscribe to any new
+ * ones which might have appeared. */
+ sd_event_source *rewatch_pids_event_source;
+
+ /* How to start OnFailure units */
+ JobMode on_failure_job_mode;
+
+ /* Tweaking the GC logic */
+ CollectMode collect_mode;
+
+ /* The current invocation ID */
+ sd_id128_t invocation_id;
+ char invocation_id_string[SD_ID128_STRING_MAX]; /* useful when logging */
+
+ /* Garbage collect us we nobody wants or requires us anymore */
+ bool stop_when_unneeded;
+
+ /* Create default dependencies */
+ bool default_dependencies;
+
+ /* Refuse manual starting, allow starting only indirectly via dependency. */
+ bool refuse_manual_start;
+
+ /* Don't allow the user to stop this unit manually, allow stopping only indirectly via dependency. */
+ bool refuse_manual_stop;
+
+ /* Allow isolation requests */
+ bool allow_isolate;
+
+ /* Ignore this unit when isolating */
+ bool ignore_on_isolate;
+
+ /* Did the last condition check succeed? */
+ bool condition_result;
+ bool assert_result;
+
+ /* Is this a transient unit? */
+ bool transient;
+
+ /* Is this a unit that is always running and cannot be stopped? */
+ bool perpetual;
+
+ /* Booleans indicating membership of this unit in the various queues */
+ bool in_load_queue:1;
+ bool in_dbus_queue:1;
+ bool in_cleanup_queue:1;
+ bool in_gc_queue:1;
+ bool in_cgroup_realize_queue:1;
+ bool in_cgroup_empty_queue:1;
+ bool in_cgroup_oom_queue:1;
+ bool in_target_deps_queue:1;
+ bool in_stop_when_unneeded_queue:1;
+
+ bool sent_dbus_new_signal:1;
+
+ bool in_audit:1;
+ bool on_console:1;
+
+ bool cgroup_realized:1;
+ bool cgroup_members_mask_valid:1;
+
+ /* Reset cgroup accounting next time we fork something off */
+ bool reset_accounting:1;
+
+ bool start_limit_hit:1;
+
+ /* Did we already invoke unit_coldplug() for this unit? */
+ bool coldplugged:1;
+
+ /* For transient units: whether to add a bus track reference after creating the unit */
+ bool bus_track_add:1;
+
+ /* Remember which unit state files we created */
+ bool exported_invocation_id:1;
+ bool exported_log_level_max:1;
+ bool exported_log_extra_fields:1;
+ bool exported_log_ratelimit_interval:1;
+ bool exported_log_ratelimit_burst:1;
+
+ /* Whether we warned about clamping the CPU quota period */
+ bool warned_clamping_cpu_quota_period:1;
+
+ /* When writing transient unit files, stores which section we stored last. If < 0, we didn't write any yet. If
+ * == 0 we are in the [Unit] section, if > 0 we are in the unit type-specific section. */
+ signed int last_section_private:2;
+} Unit;
+
+typedef struct UnitStatusMessageFormats {
+ const char *starting_stopping[2];
+ const char *finished_start_job[_JOB_RESULT_MAX];
+ const char *finished_stop_job[_JOB_RESULT_MAX];
+ /* If this entry is present, it'll be called to provide a context-dependent format string,
+ * or NULL to fall back to finished_{start,stop}_job; if those are NULL too, fall back to generic. */
+ const char *(*finished_job)(Unit *u, JobType t, JobResult result);
+} UnitStatusMessageFormats;
+
+/* Flags used when writing drop-in files or transient unit files */
+typedef enum UnitWriteFlags {
+ /* Write a runtime unit file or drop-in (i.e. one below /run) */
+ UNIT_RUNTIME = 1 << 0,
+
+ /* Write a persistent drop-in (i.e. one below /etc) */
+ UNIT_PERSISTENT = 1 << 1,
+
+ /* Place this item in the per-unit-type private section, instead of [Unit] */
+ UNIT_PRIVATE = 1 << 2,
+
+ /* Apply specifier escaping before writing */
+ UNIT_ESCAPE_SPECIFIERS = 1 << 3,
+
+ /* Apply C escaping before writing */
+ UNIT_ESCAPE_C = 1 << 4,
+} UnitWriteFlags;
+
+/* Returns true if neither persistent, nor runtime storage is requested, i.e. this is a check invocation only */
+static inline bool UNIT_WRITE_FLAGS_NOOP(UnitWriteFlags flags) {
+ return (flags & (UNIT_RUNTIME|UNIT_PERSISTENT)) == 0;
+}
+
+#include "kill.h"
+
+typedef struct UnitVTable {
+ /* How much memory does an object of this unit type need */
+ size_t object_size;
+
+ /* If greater than 0, the offset into the object where
+ * ExecContext is found, if the unit type has that */
+ size_t exec_context_offset;
+
+ /* If greater than 0, the offset into the object where
+ * CGroupContext is found, if the unit type has that */
+ size_t cgroup_context_offset;
+
+ /* If greater than 0, the offset into the object where
+ * KillContext is found, if the unit type has that */
+ size_t kill_context_offset;
+
+ /* If greater than 0, the offset into the object where the
+ * pointer to ExecRuntime is found, if the unit type has
+ * that */
+ size_t exec_runtime_offset;
+
+ /* If greater than 0, the offset into the object where the pointer to DynamicCreds is found, if the unit type
+ * has that. */
+ size_t dynamic_creds_offset;
+
+ /* The name of the configuration file section with the private settings of this unit */
+ const char *private_section;
+
+ /* Config file sections this unit type understands, separated
+ * by NUL chars */
+ const char *sections;
+
+ /* This should reset all type-specific variables. This should
+ * not allocate memory, and is called with zero-initialized
+ * data. It should hence only initialize variables that need
+ * to be set != 0. */
+ void (*init)(Unit *u);
+
+ /* This should free all type-specific variables. It should be
+ * idempotent. */
+ void (*done)(Unit *u);
+
+ /* Actually load data from disk. This may fail, and should set
+ * load_state to UNIT_LOADED, UNIT_MERGED or leave it at
+ * UNIT_STUB if no configuration could be found. */
+ int (*load)(Unit *u);
+
+ /* During deserialization we only record the intended state to return to. With coldplug() we actually put the
+ * deserialized state in effect. This is where unit_notify() should be called to start things up. Note that
+ * this callback is invoked *before* we leave the reloading state of the manager, i.e. *before* we consider the
+ * reloading to be complete. Thus, this callback should just restore the exact same state for any unit that was
+ * in effect before the reload, i.e. units should not catch up with changes happened during the reload. That's
+ * what catchup() below is for. */
+ int (*coldplug)(Unit *u);
+
+ /* This is called shortly after all units' coldplug() call was invoked, and *after* the manager left the
+ * reloading state. It's supposed to catch up with state changes due to external events we missed so far (for
+ * example because they took place while we were reloading/reexecing) */
+ void (*catchup)(Unit *u);
+
+ void (*dump)(Unit *u, FILE *f, const char *prefix);
+
+ int (*start)(Unit *u);
+ int (*stop)(Unit *u);
+ int (*reload)(Unit *u);
+
+ int (*kill)(Unit *u, KillWho w, int signo, sd_bus_error *error);
+
+ /* Clear out the various runtime/state/cache/logs/configuration data */
+ int (*clean)(Unit *u, ExecCleanMask m);
+
+ /* Freeze the unit */
+ int (*freeze)(Unit *u);
+ int (*thaw)(Unit *u);
+ bool (*can_freeze)(Unit *u);
+
+ /* Return which kind of data can be cleaned */
+ int (*can_clean)(Unit *u, ExecCleanMask *ret);
+
+ bool (*can_reload)(Unit *u);
+
+ /* Write all data that cannot be restored from other sources
+ * away using unit_serialize_item() */
+ int (*serialize)(Unit *u, FILE *f, FDSet *fds);
+
+ /* Restore one item from the serialization */
+ int (*deserialize_item)(Unit *u, const char *key, const char *data, FDSet *fds);
+
+ /* Try to match up fds with what we need for this unit */
+ void (*distribute_fds)(Unit *u, FDSet *fds);
+
+ /* Boils down the more complex internal state of this unit to
+ * a simpler one that the engine can understand */
+ UnitActiveState (*active_state)(Unit *u);
+
+ /* Returns the substate specific to this unit type as
+ * string. This is purely information so that we can give the
+ * user a more fine grained explanation in which actual state a
+ * unit is in. */
+ const char* (*sub_state_to_string)(Unit *u);
+
+ /* Additionally to UnitActiveState determine whether unit is to be restarted. */
+ bool (*will_restart)(Unit *u);
+
+ /* Return false when there is a reason to prevent this unit from being gc'ed
+ * even though nothing references it and it isn't active in any way. */
+ bool (*may_gc)(Unit *u);
+
+ /* Return true when the unit is not controlled by the manager (e.g. extrinsic mounts). */
+ bool (*is_extrinsic)(Unit *u);
+
+ /* When the unit is not running and no job for it queued we shall release its runtime resources */
+ void (*release_resources)(Unit *u);
+
+ /* Invoked on every child that died */
+ void (*sigchld_event)(Unit *u, pid_t pid, int code, int status);
+
+ /* Reset failed state if we are in failed state */
+ void (*reset_failed)(Unit *u);
+
+ /* Called whenever any of the cgroups this unit watches for ran empty */
+ void (*notify_cgroup_empty)(Unit *u);
+
+ /* Called whenever an OOM kill event on this unit was seen */
+ void (*notify_cgroup_oom)(Unit *u);
+
+ /* Called whenever a process of this unit sends us a message */
+ void (*notify_message)(Unit *u, const struct ucred *ucred, char * const *tags, FDSet *fds);
+
+ /* Called whenever a name this Unit registered for comes or goes away. */
+ void (*bus_name_owner_change)(Unit *u, const char *new_owner);
+
+ /* Called for each property that is being set */
+ int (*bus_set_property)(Unit *u, const char *name, sd_bus_message *message, UnitWriteFlags flags, sd_bus_error *error);
+
+ /* Called after at least one property got changed to apply the necessary change */
+ int (*bus_commit_properties)(Unit *u);
+
+ /* Return the unit this unit is following */
+ Unit *(*following)(Unit *u);
+
+ /* Return the set of units that are following each other */
+ int (*following_set)(Unit *u, Set **s);
+
+ /* Invoked each time a unit this unit is triggering changes
+ * state or gains/loses a job */
+ void (*trigger_notify)(Unit *u, Unit *trigger);
+
+ /* Called whenever CLOCK_REALTIME made a jump */
+ void (*time_change)(Unit *u);
+
+ /* Called whenever /etc/localtime was modified */
+ void (*timezone_change)(Unit *u);
+
+ /* Returns the next timeout of a unit */
+ int (*get_timeout)(Unit *u, usec_t *timeout);
+
+ /* Returns the main PID if there is any defined, or 0. */
+ pid_t (*main_pid)(Unit *u);
+
+ /* Returns the main PID if there is any defined, or 0. */
+ pid_t (*control_pid)(Unit *u);
+
+ /* Returns true if the unit currently needs access to the console */
+ bool (*needs_console)(Unit *u);
+
+ /* Returns the exit status to propagate in case of FailureAction=exit/SuccessAction=exit; usually returns the
+ * exit code of the "main" process of the service or similar. */
+ int (*exit_status)(Unit *u);
+
+ /* Like the enumerate() callback further down, but only enumerates the perpetual units, i.e. all units that
+ * unconditionally exist and are always active. The main reason to keep both enumeration functions separate is
+ * philosophical: the state of perpetual units should be put in place by coldplug(), while the state of those
+ * discovered through regular enumeration should be put in place by catchup(), see below. */
+ void (*enumerate_perpetual)(Manager *m);
+
+ /* This is called for each unit type and should be used to enumerate units already existing in the system
+ * internally and load them. However, everything that is loaded here should still stay in inactive state. It is
+ * the job of the catchup() call above to put the units into the discovered state. */
+ void (*enumerate)(Manager *m);
+
+ /* Type specific cleanups. */
+ void (*shutdown)(Manager *m);
+
+ /* If this function is set and return false all jobs for units
+ * of this type will immediately fail. */
+ bool (*supported)(void);
+
+ /* The strings to print in status messages */
+ UnitStatusMessageFormats status_message_formats;
+
+ /* True if transient units of this type are OK */
+ bool can_transient:1;
+
+ /* True if cgroup delegation is permissible */
+ bool can_delegate:1;
+
+ /* True if the unit type triggers other units, i.e. can have a UNIT_TRIGGERS dependency */
+ bool can_trigger:1;
+
+ /* True if the unit type knows a failure state, and thus can be source of an OnFailure= dependency */
+ bool can_fail:1;
+
+ /* True if units of this type shall be startable only once and then never again */
+ bool once_only:1;
+
+ /* True if queued jobs of this type should be GC'ed if no other job needs them anymore */
+ bool gc_jobs:1;
+
+ /* True if systemd-oomd can monitor and act on this unit's recursive children's cgroup(s) */
+ bool can_set_managed_oom:1;
+} UnitVTable;
+
+extern const UnitVTable * const unit_vtable[_UNIT_TYPE_MAX];
+
+static inline const UnitVTable* UNIT_VTABLE(Unit *u) {
+ return unit_vtable[u->type];
+}
+
+/* For casting a unit into the various unit types */
+#define DEFINE_CAST(UPPERCASE, MixedCase) \
+ static inline MixedCase* UPPERCASE(Unit *u) { \
+ if (_unlikely_(!u || u->type != UNIT_##UPPERCASE)) \
+ return NULL; \
+ \
+ return (MixedCase*) u; \
+ }
+
+/* For casting the various unit types into a unit */
+#define UNIT(u) \
+ ({ \
+ typeof(u) _u_ = (u); \
+ Unit *_w_ = _u_ ? &(_u_)->meta : NULL; \
+ _w_; \
+ })
+
+#define UNIT_HAS_EXEC_CONTEXT(u) (UNIT_VTABLE(u)->exec_context_offset > 0)
+#define UNIT_HAS_CGROUP_CONTEXT(u) (UNIT_VTABLE(u)->cgroup_context_offset > 0)
+#define UNIT_HAS_KILL_CONTEXT(u) (UNIT_VTABLE(u)->kill_context_offset > 0)
+
+static inline Unit* UNIT_TRIGGER(Unit *u) {
+ return hashmap_first_key(u->dependencies[UNIT_TRIGGERS]);
+}
+
+Unit *unit_new(Manager *m, size_t size);
+void unit_free(Unit *u);
+DEFINE_TRIVIAL_CLEANUP_FUNC(Unit *, unit_free);
+
+int unit_new_for_name(Manager *m, size_t size, const char *name, Unit **ret);
+int unit_add_name(Unit *u, const char *name);
+
+int unit_add_dependency(Unit *u, UnitDependency d, Unit *other, bool add_reference, UnitDependencyMask mask);
+int unit_add_two_dependencies(Unit *u, UnitDependency d, UnitDependency e, Unit *other, bool add_reference, UnitDependencyMask mask);
+
+int unit_add_dependency_by_name(Unit *u, UnitDependency d, const char *name, bool add_reference, UnitDependencyMask mask);
+int unit_add_two_dependencies_by_name(Unit *u, UnitDependency d, UnitDependency e, const char *name, bool add_reference, UnitDependencyMask mask);
+
+int unit_add_exec_dependencies(Unit *u, ExecContext *c);
+
+int unit_choose_id(Unit *u, const char *name);
+int unit_set_description(Unit *u, const char *description);
+
+bool unit_may_gc(Unit *u);
+
+static inline bool unit_is_extrinsic(Unit *u) {
+ return u->perpetual ||
+ (UNIT_VTABLE(u)->is_extrinsic && UNIT_VTABLE(u)->is_extrinsic(u));
+}
+
+void unit_add_to_load_queue(Unit *u);
+void unit_add_to_dbus_queue(Unit *u);
+void unit_add_to_cleanup_queue(Unit *u);
+void unit_add_to_gc_queue(Unit *u);
+void unit_add_to_target_deps_queue(Unit *u);
+void unit_submit_to_stop_when_unneeded_queue(Unit *u);
+
+int unit_merge(Unit *u, Unit *other);
+int unit_merge_by_name(Unit *u, const char *other);
+
+Unit *unit_follow_merge(Unit *u) _pure_;
+
+int unit_load_fragment_and_dropin(Unit *u, bool fragment_required);
+int unit_load(Unit *unit);
+
+int unit_set_slice(Unit *u, Unit *slice);
+int unit_set_default_slice(Unit *u);
+
+const char *unit_description(Unit *u) _pure_;
+const char *unit_status_string(Unit *u) _pure_;
+
+bool unit_has_name(const Unit *u, const char *name);
+
+UnitActiveState unit_active_state(Unit *u);
+FreezerState unit_freezer_state(Unit *u);
+int unit_freezer_state_kernel(Unit *u, FreezerState *ret);
+
+const char* unit_sub_state_to_string(Unit *u);
+
+void unit_dump(Unit *u, FILE *f, const char *prefix);
+
+bool unit_can_reload(Unit *u) _pure_;
+bool unit_can_start(Unit *u) _pure_;
+bool unit_can_stop(Unit *u) _pure_;
+bool unit_can_isolate(Unit *u) _pure_;
+
+int unit_start(Unit *u);
+int unit_stop(Unit *u);
+int unit_reload(Unit *u);
+
+int unit_kill(Unit *u, KillWho w, int signo, sd_bus_error *error);
+int unit_kill_common(Unit *u, KillWho who, int signo, pid_t main_pid, pid_t control_pid, sd_bus_error *error);
+
+typedef enum UnitNotifyFlags {
+ UNIT_NOTIFY_RELOAD_FAILURE = 1 << 0,
+ UNIT_NOTIFY_WILL_AUTO_RESTART = 1 << 1,
+ UNIT_NOTIFY_SKIP_CONDITION = 1 << 2,
+} UnitNotifyFlags;
+
+void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns, UnitNotifyFlags flags);
+
+int unit_watch_pid(Unit *u, pid_t pid, bool exclusive);
+void unit_unwatch_pid(Unit *u, pid_t pid);
+void unit_unwatch_all_pids(Unit *u);
+
+int unit_enqueue_rewatch_pids(Unit *u);
+void unit_dequeue_rewatch_pids(Unit *u);
+
+int unit_install_bus_match(Unit *u, sd_bus *bus, const char *name);
+int unit_watch_bus_name(Unit *u, const char *name);
+void unit_unwatch_bus_name(Unit *u, const char *name);
+
+bool unit_job_is_applicable(Unit *u, JobType j);
+
+int set_unit_path(const char *p);
+
+char *unit_dbus_path(Unit *u);
+char *unit_dbus_path_invocation_id(Unit *u);
+
+int unit_load_related_unit(Unit *u, const char *type, Unit **_found);
+
+bool unit_can_serialize(Unit *u) _pure_;
+
+int unit_serialize(Unit *u, FILE *f, FDSet *fds, bool serialize_jobs);
+int unit_deserialize(Unit *u, FILE *f, FDSet *fds);
+int unit_deserialize_skip(FILE *f);
+
+int unit_add_node_dependency(Unit *u, const char *what, UnitDependency d, UnitDependencyMask mask);
+int unit_add_blockdev_dependency(Unit *u, const char *what, UnitDependencyMask mask);
+
+int unit_coldplug(Unit *u);
+void unit_catchup(Unit *u);
+
+void unit_status_printf(Unit *u, StatusType status_type, const char *status, const char *unit_status_msg_format) _printf_(4, 0);
+
+bool unit_need_daemon_reload(Unit *u);
+
+void unit_reset_failed(Unit *u);
+
+Unit *unit_following(Unit *u);
+int unit_following_set(Unit *u, Set **s);
+
+const char *unit_slice_name(Unit *u);
+
+bool unit_stop_pending(Unit *u) _pure_;
+bool unit_inactive_or_pending(Unit *u) _pure_;
+bool unit_active_or_pending(Unit *u);
+bool unit_will_restart_default(Unit *u);
+bool unit_will_restart(Unit *u);
+
+int unit_add_default_target_dependency(Unit *u, Unit *target);
+
+void unit_start_on_failure(Unit *u);
+void unit_trigger_notify(Unit *u);
+
+UnitFileState unit_get_unit_file_state(Unit *u);
+int unit_get_unit_file_preset(Unit *u);
+
+Unit* unit_ref_set(UnitRef *ref, Unit *source, Unit *target);
+void unit_ref_unset(UnitRef *ref);
+
+#define UNIT_DEREF(ref) ((ref).target)
+#define UNIT_ISSET(ref) (!!(ref).target)
+
+int unit_patch_contexts(Unit *u);
+
+ExecContext *unit_get_exec_context(Unit *u) _pure_;
+KillContext *unit_get_kill_context(Unit *u) _pure_;
+CGroupContext *unit_get_cgroup_context(Unit *u) _pure_;
+
+ExecRuntime *unit_get_exec_runtime(Unit *u) _pure_;
+
+int unit_setup_exec_runtime(Unit *u);
+int unit_setup_dynamic_creds(Unit *u);
+
+char* unit_escape_setting(const char *s, UnitWriteFlags flags, char **buf);
+char* unit_concat_strv(char **l, UnitWriteFlags flags);
+
+int unit_write_setting(Unit *u, UnitWriteFlags flags, const char *name, const char *data);
+int unit_write_settingf(Unit *u, UnitWriteFlags mode, const char *name, const char *format, ...) _printf_(4,5);
+
+int unit_kill_context(Unit *u, KillContext *c, KillOperation k, pid_t main_pid, pid_t control_pid, bool main_pid_alien);
+
+int unit_make_transient(Unit *u);
+
+int unit_require_mounts_for(Unit *u, const char *path, UnitDependencyMask mask);
+
+bool unit_type_supported(UnitType t);
+
+bool unit_is_pristine(Unit *u);
+
+bool unit_is_unneeded(Unit *u);
+
+pid_t unit_control_pid(Unit *u);
+pid_t unit_main_pid(Unit *u);
+
+void unit_warn_if_dir_nonempty(Unit *u, const char* where);
+int unit_fail_if_noncanonical(Unit *u, const char* where);
+
+int unit_test_start_limit(Unit *u);
+
+int unit_ref_uid_gid(Unit *u, uid_t uid, gid_t gid);
+void unit_unref_uid_gid(Unit *u, bool destroy_now);
+
+void unit_notify_user_lookup(Unit *u, uid_t uid, gid_t gid);
+
+int unit_acquire_invocation_id(Unit *u);
+
+bool unit_shall_confirm_spawn(Unit *u);
+
+int unit_set_exec_params(Unit *s, ExecParameters *p);
+
+int unit_fork_helper_process(Unit *u, const char *name, pid_t *ret);
+int unit_fork_and_watch_rm_rf(Unit *u, char **paths, pid_t *ret_pid);
+
+void unit_remove_dependencies(Unit *u, UnitDependencyMask mask);
+
+void unit_export_state_files(Unit *u);
+void unit_unlink_state_files(Unit *u);
+
+int unit_prepare_exec(Unit *u);
+
+int unit_log_leftover_process_start(pid_t pid, int sig, void *userdata);
+int unit_log_leftover_process_stop(pid_t pid, int sig, void *userdata);
+int unit_warn_leftover_processes(Unit *u, cg_kill_log_func_t log_func);
+
+bool unit_needs_console(Unit *u);
+
+const char *unit_label_path(const Unit *u);
+
+int unit_pid_attachable(Unit *unit, pid_t pid, sd_bus_error *error);
+
+static inline bool unit_has_job_type(Unit *u, JobType type) {
+ return u && u->job && u->job->type == type;
+}
+
+/* unit_log_skip is for cases like ExecCondition= where a unit is considered "done"
+ * after some execution, rather than succeeded or failed. */
+void unit_log_skip(Unit *u, const char *result);
+void unit_log_success(Unit *u);
+void unit_log_failure(Unit *u, const char *result);
+static inline void unit_log_result(Unit *u, bool success, const char *result) {
+ if (success)
+ unit_log_success(u);
+ else
+ unit_log_failure(u, result);
+}
+
+void unit_log_process_exit(Unit *u, const char *kind, const char *command, bool success, int code, int status);
+
+int unit_exit_status(Unit *u);
+int unit_success_action_exit_status(Unit *u);
+int unit_failure_action_exit_status(Unit *u);
+
+int unit_test_trigger_loaded(Unit *u);
+
+void unit_destroy_runtime_data(Unit *u, const ExecContext *context);
+int unit_clean(Unit *u, ExecCleanMask mask);
+int unit_can_clean(Unit *u, ExecCleanMask *ret_mask);
+
+bool unit_can_freeze(Unit *u);
+int unit_freeze(Unit *u);
+void unit_frozen(Unit *u);
+
+int unit_thaw(Unit *u);
+void unit_thawed(Unit *u);
+
+int unit_freeze_vtable_common(Unit *u);
+int unit_thaw_vtable_common(Unit *u);
+
+/* Macros which append UNIT= or USER_UNIT= to the message */
+
+#define log_unit_full_errno(unit, level, error, ...) \
+ ({ \
+ const Unit *_u = (unit); \
+ (log_get_max_level() < LOG_PRI(level)) ? -ERRNO_VALUE(error) : \
+ _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__) : \
+ log_internal(level, error, PROJECT_FILE, __LINE__, __func__, ##__VA_ARGS__); \
+ })
+
+#define log_unit_full(unit, level, ...) (void) log_unit_full_errno(unit, level, 0, __VA_ARGS__)
+
+#define log_unit_debug(unit, ...) log_unit_full_errno(unit, LOG_DEBUG, 0, __VA_ARGS__)
+#define log_unit_info(unit, ...) log_unit_full(unit, LOG_INFO, __VA_ARGS__)
+#define log_unit_notice(unit, ...) log_unit_full(unit, LOG_NOTICE, __VA_ARGS__)
+#define log_unit_warning(unit, ...) log_unit_full(unit, LOG_WARNING, __VA_ARGS__)
+#define log_unit_error(unit, ...) log_unit_full(unit, LOG_ERR, __VA_ARGS__)
+
+#define log_unit_debug_errno(unit, error, ...) log_unit_full_errno(unit, LOG_DEBUG, error, __VA_ARGS__)
+#define log_unit_info_errno(unit, error, ...) log_unit_full_errno(unit, LOG_INFO, error, __VA_ARGS__)
+#define log_unit_notice_errno(unit, error, ...) log_unit_full_errno(unit, LOG_NOTICE, error, __VA_ARGS__)
+#define log_unit_warning_errno(unit, error, ...) log_unit_full_errno(unit, LOG_WARNING, error, __VA_ARGS__)
+#define log_unit_error_errno(unit, error, ...) log_unit_full_errno(unit, LOG_ERR, error, __VA_ARGS__)
+
+#define LOG_UNIT_MESSAGE(unit, fmt, ...) "MESSAGE=%s: " fmt, (unit)->id, ##__VA_ARGS__
+#define LOG_UNIT_ID(unit) (unit)->manager->unit_log_format_string, (unit)->id
+#define LOG_UNIT_INVOCATION_ID(unit) (unit)->manager->invocation_log_format_string, (unit)->invocation_id_string
+
+const char* collect_mode_to_string(CollectMode m) _const_;
+CollectMode collect_mode_from_string(const char *s) _pure_;