Adding upstream version 241.upstream/241upstream

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

1 files changed, 856 insertions, 0 deletions

diff --git a/src/core/unit.h b/src/core/unit.h
new file mode 100644
index 0000000..43cf157
--- /dev/null
+++ b/src/core/unit.h
@@ -0,0 +1,856 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdbool.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "bpf-program.h"
+#include "condition.h"
+#include "emergency-action.h"
+#include "install.h"
+#include "list.h"
+#include "unit-name.h"
+#include "cgroup.h"
+
+typedef struct UnitRef UnitRef;
+
+typedef enum KillOperation {
+        KILL_TERMINATE,
+        KILL_TERMINATE_AND_LOG,
+        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);
+}
+
+/* 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/.requries 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;
+
+        char *id; /* One name is special because we use it for identification. Points to an entry in the names set */
+        char *instance;
+
+        Set *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_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;
+
+        /* 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);
+
+        /* 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_limit;
+        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 */
+
+        /* 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 specifiying 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) */
+        int cgroup_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;
+
+        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_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_rate_limit_interval:1;
+        bool exported_log_rate_limit_burst: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];
+} 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);
+
+        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);
+
+        /* 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 a process of this unit sends us a message */
+        void (*notify_message)(Unit *u, const struct ucred *ucred, char **tags, FDSet *fds);
+
+        /* Called whenever a name this Unit registered for comes or goes away. */
+        void (*bus_name_owner_change)(Unit *u, const char *name, const char *old_owner, 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 bus vtable */
+        const sd_bus_vtable *bus_vtable;
+
+        /* 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 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;
+} 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);
+
+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);
+int unit_load_fragment_and_dropin_optional(Unit *u);
+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_;
+
+bool unit_has_name(const Unit *u, const char *name);
+
+UnitActiveState unit_active_state(Unit *u);
+
+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,
+} UnitNotifyFlags;
+
+void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns, UnitNotifyFlags flags);
+
+int unit_watch_pid(Unit *u, pid_t pid);
+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, bool wants, UnitDependency d, UnitDependencyMask mask);
+
+int unit_coldplug(Unit *u);
+void unit_catchup(Unit *u);
+
+void unit_status_printf(Unit *u, const char *status, const char *unit_status_msg_format) _printf_(3, 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(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);
+
+static inline bool unit_supported(Unit *u) {
+        return unit_type_supported(u->type);
+}
+
+void unit_warn_if_dir_nonempty(Unit *u, const char* where);
+int unit_fail_if_noncanonical(Unit *u, const char* where);
+
+int unit_start_limit_test(Unit *u);
+
+void unit_unref_uid(Unit *u, bool destroy_now);
+int unit_ref_uid(Unit *u, uid_t uid, bool clean_ipc);
+
+void unit_unref_gid(Unit *u, bool destroy_now);
+int unit_ref_gid(Unit *u, gid_t gid, bool clean_ipc);
+
+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_set_invocation_id(Unit *u, sd_id128_t id);
+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);
+
+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);
+
+void unit_warn_leftover_processes(Unit *u);
+
+bool unit_needs_console(Unit *u);
+
+const char *unit_label_path(Unit *u);
+
+int unit_pid_attachable(Unit *unit, pid_t pid, sd_bus_error *error);
+
+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, int level, const char *kind, const char *command, 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);
+
+/* Macros which append UNIT= or USER_UNIT= to the message */
+
+#define log_unit_full(unit, level, error, ...)                          \
+        ({                                                              \
+                const Unit *_u = (unit);                                \
+                _u ? log_object_internal(level, error, __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, __FILE__, __LINE__, __func__, ##__VA_ARGS__); \
+        })
+
+#define log_unit_debug(unit, ...)   log_unit_full(unit, LOG_DEBUG, 0, ##__VA_ARGS__)
+#define log_unit_info(unit, ...)    log_unit_full(unit, LOG_INFO, 0, ##__VA_ARGS__)
+#define log_unit_notice(unit, ...)  log_unit_full(unit, LOG_NOTICE, 0, ##__VA_ARGS__)
+#define log_unit_warning(unit, ...) log_unit_full(unit, LOG_WARNING, 0, ##__VA_ARGS__)
+#define log_unit_error(unit, ...)   log_unit_full(unit, LOG_ERR, 0, ##__VA_ARGS__)
+
+#define log_unit_debug_errno(unit, error, ...)   log_unit_full(unit, LOG_DEBUG, error, ##__VA_ARGS__)
+#define log_unit_info_errno(unit, error, ...)    log_unit_full(unit, LOG_INFO, error, ##__VA_ARGS__)
+#define log_unit_notice_errno(unit, error, ...)  log_unit_full(unit, LOG_NOTICE, error, ##__VA_ARGS__)
+#define log_unit_warning_errno(unit, error, ...) log_unit_full(unit, LOG_WARNING, error, ##__VA_ARGS__)
+#define log_unit_error_errno(unit, error, ...)   log_unit_full(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_;