From b750101eb236130cf056c675997decbac904cc49 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 17:35:18 +0200 Subject: Adding upstream version 252.22. Signed-off-by: Daniel Baumann --- src/core/unit.h | 1194 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1194 insertions(+) create mode 100644 src/core/unit.h (limited to 'src/core/unit.h') diff --git a/src/core/unit.h b/src/core/unit.h new file mode 100644 index 0000000..65a1d26 --- /dev/null +++ b/src/core/unit.h @@ -0,0 +1,1194 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +#pragma once + +#include +#include +#include +#include + +#include "sd-id128.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 = -EINVAL, +} KillOperation; + +typedef enum CollectMode { + COLLECT_INACTIVE, + COLLECT_INACTIVE_OR_FAILED, + _COLLECT_MODE_MAX, + _COLLECT_MODE_INVALID = -EINVAL, +} 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 initially configured from the mount unit file however the dependency will be updated + * from /proc/self/mountinfo as soon as the kernel will make the entry for that mount available in + * the /proc file */ + UNIT_DEPENDENCY_MOUNT_FILE = 1 << 5, + + /* A dependency created or updated because of data read from /proc/self/mountinfo */ + UNIT_DEPENDENCY_MOUNTINFO = 1 << 6, + + /* A dependency created because of data read from /proc/swaps and no other configuration source */ + UNIT_DEPENDENCY_PROC_SWAP = 1 << 7, + + /* A dependency for units in slices assigned by directly setting Slice= */ + UNIT_DEPENDENCY_SLICE_PROPERTY = 1 << 8, + + _UNIT_DEPENDENCY_MASK_FULL = (1 << 9) - 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; + +/* Store information about why a unit was activated. + * We start with trigger units (.path/.timer), eventually it will be expanded to include more metadata. */ +typedef struct ActivationDetails { + unsigned n_ref; + UnitType trigger_unit_type; + char *trigger_unit_name; +} ActivationDetails; + +/* For casting an activation event into the various unit-specific types */ +#define DEFINE_ACTIVATION_DETAILS_CAST(UPPERCASE, MixedCase, UNIT_TYPE) \ + static inline MixedCase* UPPERCASE(ActivationDetails *a) { \ + if (_unlikely_(!a || a->trigger_unit_type != UNIT_##UNIT_TYPE)) \ + return NULL; \ + \ + return (MixedCase*) a; \ + } + +/* For casting the various unit types into a unit */ +#define ACTIVATION_DETAILS(u) \ + ({ \ + typeof(u) _u_ = (u); \ + ActivationDetails *_w_ = _u_ ? &(_u_)->meta : NULL; \ + _w_; \ + }) + +ActivationDetails *activation_details_new(Unit *trigger_unit); +ActivationDetails *activation_details_ref(ActivationDetails *p); +ActivationDetails *activation_details_unref(ActivationDetails *p); +void activation_details_serialize(ActivationDetails *p, FILE *f); +int activation_details_deserialize(const char *key, const char *value, ActivationDetails **info); +int activation_details_append_env(ActivationDetails *info, char ***strv); +int activation_details_append_pair(ActivationDetails *info, char ***strv); +DEFINE_TRIVIAL_CLEANUP_FUNC(ActivationDetails*, activation_details_unref); + +typedef struct ActivationDetailsVTable { + /* How much memory does an object of this activation type need */ + size_t object_size; + + /* 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)(ActivationDetails *info, Unit *trigger_unit); + + /* This should free all type-specific variables. It should be idempotent. */ + void (*done)(ActivationDetails *info); + + /* This should serialize all type-specific variables. */ + void (*serialize)(ActivationDetails *info, FILE *f); + + /* This should deserialize all type-specific variables, one at a time. */ + int (*deserialize)(const char *key, const char *value, ActivationDetails **info); + + /* This should format the type-specific variables for the env block of the spawned service, + * and return the number of added items. */ + int (*append_env)(ActivationDetails *info, char ***strv); + + /* This should append type-specific variables as key/value pairs for the D-Bus property of the job, + * and return the number of added pairs. */ + int (*append_pair)(ActivationDetails *info, char ***strv); +} ActivationDetailsVTable; + +extern const ActivationDetailsVTable * const activation_details_vtable[_UNIT_TYPE_MAX]; + +static inline const ActivationDetailsVTable* ACTIVATION_DETAILS_VTABLE(const ActivationDetails *a) { + assert(a); + assert(a->trigger_unit_type < _UNIT_TYPE_MAX); + + return activation_details_vtable[a->trigger_unit_type]; +} + +/* Newer LLVM versions don't like implicit casts from large pointer types to smaller enums, hence let's add + * explicit type-safe helpers for that. */ +static inline UnitDependency UNIT_DEPENDENCY_FROM_PTR(const void *p) { + return PTR_TO_INT(p); +} + +static inline void* UNIT_DEPENDENCY_TO_PTR(UnitDependency d) { + return INT_TO_PTR(d); +} + +#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; /* The one special name that we use for identification */ + char *instance; + + Set *aliases; /* All the other names. */ + + /* For each dependency type we can look up another Hashmap with this, whose key is a Unit* object, + * and whose value encodes why the dependency exists, using the UnitDependencyInfo type. i.e. a + * Hashmap(UnitDependency → Hashmap(Unit* → UnitDependencyInfo)) */ + Hashmap *dependencies; + + /* Similar, for RequiresMountsFor= path dependencies. The key is the path, the value the + * UnitDependencyInfo type */ + Hashmap *requires_mounts_for; + + char *description; + char **documentation; + + /* The SELinux context used for checking access to this unit read off the unit file at load time (do + * not confuse with the selinux_context field in ExecContext which is the SELinux context we'll set + * for processes) */ + char *access_selinux_context; + + 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; + + /* Freezer state */ + sd_bus_message *pending_freezer_message; + FreezerState freezer_state; + + /* Job timeout and action to take */ + EmergencyAction job_timeout_action; + usec_t job_timeout; + usec_t job_running_timeout; + char *job_timeout_reboot_arg; + + /* 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; + + /* 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; + + /* 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 shall be checked for clean-up. */ + LIST_FIELDS(Unit, stop_when_unneeded_queue); + + /* Queue of units that have an Uphold= dependency from some other unit, and should be checked for starting */ + LIST_FIELDS(Unit, start_when_upheld_queue); + + /* Queue of units that have a BindTo= dependency on some other unit, and should possibly be shut down */ + LIST_FIELDS(Unit, stop_when_bound_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; + + /* The unit has been marked for reload, restart, etc. Stored as 1u << marker1 | 1u << marker2. */ + unsigned markers; + + /* 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 StopWhenUnneeded=, BindsTo=, Uphold= logic */ + RateLimit auto_start_stop_ratelimit; + sd_event_source *auto_start_stop_event_source; + + /* 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 OOM kills initiated 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; + uint64_t cgroup_id; + 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; + uint64_t ip_accounting_extra[_CGROUP_IP_ACCOUNTING_METRIC_MAX]; + + 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; + + /* BPF programs managed (e.g. loaded to kernel) by an entity external to systemd, + * attached to unit cgroup by provided program fd and attach type. */ + Hashmap *bpf_foreign_by_key; + + FDSet *initial_socket_bind_link_fds; +#if BPF_FRAMEWORK + /* BPF links to BPF programs attached to cgroup/bind{4|6} hooks and + * responsible for allowing or denying a unit to bind(2) to a socket + * address. */ + struct bpf_link *ipv4_socket_bind_link; + struct bpf_link *ipv6_socket_bind_link; +#endif + + FDSet *initial_restric_ifaces_link_fds; +#if BPF_FRAMEWORK + struct bpf_link *restrict_ifaces_ingress_bpf_link; + struct bpf_link *restrict_ifaces_egress_bpf_link; +#endif + + /* 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 OnSuccess=/OnFailure= units */ + JobMode on_success_job_mode; + JobMode on_failure_job_mode; + + /* If the job had a specific trigger that needs to be advertised (eg: a path unit), store it. */ + ActivationDetails *activation_details; + + /* 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 in_start_when_upheld_queue:1; + bool in_stop_when_bound_queue:1; + + bool sent_dbus_new_signal:1; + + bool job_running_timeout_set: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, + + /* Escape elements of ExecStart= syntax before writing */ + UNIT_ESCAPE_EXEC_SYNTAX = 1 << 4, + + /* Apply C escaping before writing */ + UNIT_ESCAPE_C = 1 << 5, +} 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); + + /* Serialize state and file descriptors that should be carried over into the new + * instance after reexecution. */ + 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, bool managed_oom); + + /* 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); + + /* Return a copy of the status string pointer. */ + const char* (*status_text)(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 returns false all jobs for units + * of this type will immediately fail. */ + bool (*supported)(void); + + /* If this function is set, it's invoked first as part of starting a unit to allow start rate + * limiting checks to occur before we do anything else. */ + int (*can_start)(Unit *u); + + /* The strings to print in status messages */ + UnitStatusMessageFormats status_message_formats; + + /* True if transient units of this type are OK */ + bool can_transient; + + /* True if cgroup delegation is permissible */ + bool can_delegate; + + /* True if the unit type triggers other units, i.e. can have a UNIT_TRIGGERS dependency */ + bool can_trigger; + + /* True if the unit type knows a failure state, and thus can be source of an OnFailure= dependency */ + bool can_fail; + + /* True if units of this type shall be startable only once and then never again */ + bool once_only; + + /* Do not serialize this unit when preparing for root switch */ + bool exclude_from_switch_root_serialization; + + /* True if queued jobs of this type should be GC'ed if no other job needs them anymore */ + bool gc_jobs; + + /* True if systemd-oomd can monitor and act on this unit's recursive children's cgroups */ + bool can_set_managed_oom; +} UnitVTable; + +extern const UnitVTable * const unit_vtable[_UNIT_TYPE_MAX]; + +static inline const UnitVTable* UNIT_VTABLE(const 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) + +Unit* unit_has_dependency(const Unit *u, UnitDependencyAtom atom, Unit *other); +int unit_get_dependency_array(const Unit *u, UnitDependencyAtom atom, Unit ***ret_array); + +static inline Hashmap* unit_get_dependencies(Unit *u, UnitDependency d) { + return hashmap_get(u->dependencies, UNIT_DEPENDENCY_TO_PTR(d)); +} + +static inline Unit* UNIT_TRIGGER(Unit *u) { + return unit_has_dependency(u, UNIT_ATOM_TRIGGERS, NULL); +} + +static inline Unit* UNIT_GET_SLICE(const Unit *u) { + return unit_has_dependency(u, UNIT_ATOM_IN_SLICE, NULL); +} + +Unit* unit_new(Manager *m, size_t size); +Unit* 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)); +} + +static inline const char* unit_status_text(Unit *u) { + if (u && UNIT_VTABLE(u)->status_text) + return UNIT_VTABLE(u)->status_text(u); + return NULL; +} + +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); +void unit_submit_to_start_when_upheld_queue(Unit *u); +void unit_submit_to_stop_when_bound_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, char **combined); + +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); + +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, ActivationDetails *details); +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); + +void unit_notify_cgroup_oom(Unit *u, bool managed_oom); + +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, 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); + +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 *format, const char *ident) _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, const char *dependency_name, UnitDependencyAtom atom, JobMode job_mode); +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(const 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); +bool unit_is_upheld_by_active(Unit *u, Unit **ret_culprit); +bool unit_is_bound_by_inactive(Unit *u, Unit **ret_culprit); + +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_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); +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); + +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; +} + +static inline bool unit_log_level_test(const Unit *u, int level) { + ExecContext *ec = unit_get_exec_context(u); + return !ec || ec->log_level_max < 0 || ec->log_level_max >= LOG_PRI(level); +} + +/* 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); + +Condition *unit_find_failed_condition(Unit *u); + +/* Macros which append UNIT= or USER_UNIT= to the message */ + +#define log_unit_full_errno_zerook(unit, level, error, ...) \ + ({ \ + const Unit *_u = (unit); \ + const int _l = (level); \ + (log_get_max_level() < LOG_PRI(_l) || (_u && !unit_log_level_test(_u, _l))) ? -ERRNO_VALUE(error) : \ + _u ? log_object_internal(_l, 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(_l, error, PROJECT_FILE, __LINE__, __func__, ##__VA_ARGS__); \ + }) + +#define log_unit_full_errno(unit, level, error, ...) \ + ({ \ + int _error = (error); \ + ASSERT_NON_ZERO(_error); \ + log_unit_full_errno_zerook(unit, level, _error, ##__VA_ARGS__); \ + }) + +#define log_unit_full(unit, level, ...) (void) log_unit_full_errno_zerook(unit, level, 0, __VA_ARGS__) + +#define log_unit_debug(unit, ...) log_unit_full(unit, LOG_DEBUG, __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__) + +#if LOG_TRACE +# define log_unit_trace(...) log_unit_debug(__VA_ARGS__) +# define log_unit_trace_errno(...) log_unit_debug_errno(__VA_ARGS__) +#else +# define log_unit_trace(...) do {} while (0) +# define log_unit_trace_errno(e, ...) (-ERRNO_VALUE(e)) +#endif + +#define log_unit_struct_errno(unit, level, error, ...) \ + ({ \ + const Unit *_u = (unit); \ + const int _l = (level); \ + unit_log_level_test(_u, _l) ? \ + log_struct_errno(_l, error, __VA_ARGS__, LOG_UNIT_ID(_u)) : \ + -ERRNO_VALUE(error); \ + }) + +#define log_unit_struct(unit, level, ...) log_unit_struct_errno(unit, level, 0, __VA_ARGS__) + +#define log_unit_struct_iovec_errno(unit, level, error, iovec, n_iovec) \ + ({ \ + const int _l = (level); \ + unit_log_level_test(unit, _l) ? \ + log_struct_iovec_errno(_l, error, iovec, n_iovec) : \ + -ERRNO_VALUE(error); \ + }) + +#define log_unit_struct_iovec(unit, level, iovec, n_iovec) log_unit_struct_iovec_errno(unit, level, 0, iovec, n_iovec) + +/* Like LOG_MESSAGE(), but with the unit name prefixed. */ +#define LOG_UNIT_MESSAGE(unit, fmt, ...) LOG_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_; + +typedef struct UnitForEachDependencyData { + /* Stores state for the FOREACH macro below for iterating through all deps that have any of the + * specified dependency atom bits set */ + UnitDependencyAtom match_atom; + Hashmap *by_type, *by_unit; + void *current_type; + Iterator by_type_iterator, by_unit_iterator; + Unit **current_unit; +} UnitForEachDependencyData; + +/* Iterates through all dependencies that have a specific atom in the dependency type set. This tries to be + * smart: if the atom is unique, we'll directly go to right entry. Otherwise we'll iterate through the + * per-dependency type hashmap and match all dep that have the right atom set. */ +#define _UNIT_FOREACH_DEPENDENCY(other, u, ma, data) \ + for (UnitForEachDependencyData data = { \ + .match_atom = (ma), \ + .by_type = (u)->dependencies, \ + .by_type_iterator = ITERATOR_FIRST, \ + .current_unit = &(other), \ + }; \ + ({ \ + UnitDependency _dt = _UNIT_DEPENDENCY_INVALID; \ + bool _found; \ + \ + if (data.by_type && ITERATOR_IS_FIRST(data.by_type_iterator)) { \ + _dt = unit_dependency_from_unique_atom(data.match_atom); \ + if (_dt >= 0) { \ + data.by_unit = hashmap_get(data.by_type, UNIT_DEPENDENCY_TO_PTR(_dt)); \ + data.current_type = UNIT_DEPENDENCY_TO_PTR(_dt); \ + data.by_type = NULL; \ + _found = !!data.by_unit; \ + } \ + } \ + if (_dt < 0) \ + _found = hashmap_iterate(data.by_type, \ + &data.by_type_iterator, \ + (void**)&(data.by_unit), \ + (const void**) &(data.current_type)); \ + _found; \ + }); ) \ + if ((unit_dependency_to_atom(UNIT_DEPENDENCY_FROM_PTR(data.current_type)) & data.match_atom) != 0) \ + for (data.by_unit_iterator = ITERATOR_FIRST; \ + hashmap_iterate(data.by_unit, \ + &data.by_unit_iterator, \ + NULL, \ + (const void**) data.current_unit); ) + +/* Note: this matches deps that have *any* of the atoms specified in match_atom set */ +#define UNIT_FOREACH_DEPENDENCY(other, u, match_atom) \ + _UNIT_FOREACH_DEPENDENCY(other, u, match_atom, UNIQ_T(data, UNIQ)) -- cgit v1.2.3