diff options
Diffstat (limited to 'unit.c')
| -rw-r--r-- | unit.c | 807 |
1 files changed, 807 insertions, 0 deletions
diff --git a/unit.c b/unit.c new file mode 100644 index 0000000000..15401e24fe --- /dev/null +++ b/unit.c @@ -0,0 +1,807 @@ +/*-*- Mode: C; c-basic-offset: 8 -*-*/ + +#include <assert.h> +#include <errno.h> +#include <string.h> +#include <sys/epoll.h> +#include <sys/timerfd.h> +#include <sys/poll.h> + +#include "set.h" +#include "unit.h" +#include "macro.h" +#include "strv.h" +#include "load-fragment.h" +#include "load-dropin.h" +#include "log.h" + +const UnitVTable * const unit_vtable[_UNIT_TYPE_MAX] = { + [UNIT_SERVICE] = &service_vtable, + [UNIT_TIMER] = &timer_vtable, + [UNIT_SOCKET] = &socket_vtable, + [UNIT_TARGET] = &target_vtable, + [UNIT_DEVICE] = &device_vtable, + [UNIT_MOUNT] = &mount_vtable, + [UNIT_AUTOMOUNT] = &automount_vtable, + [UNIT_SNAPSHOT] = &snapshot_vtable +}; + +UnitType unit_name_to_type(const char *n) { + UnitType t; + + assert(n); + + for (t = 0; t < _UNIT_TYPE_MAX; t++) + if (endswith(n, unit_vtable[t]->suffix)) + return t; + + return _UNIT_TYPE_INVALID; +} + +#define VALID_CHARS \ + "0123456789" \ + "abcdefghijklmnopqrstuvwxyz" \ + "ABCDEFGHIJKLMNOPQRSTUVWXYZ" \ + "-_" + +bool unit_name_is_valid(const char *n) { + UnitType t; + const char *e, *i; + + assert(n); + + if (strlen(n) >= UNIT_NAME_MAX) + return false; + + t = unit_name_to_type(n); + if (t < 0 || t >= _UNIT_TYPE_MAX) + return false; + + if (!(e = strrchr(n, '.'))) + return false; + + for (i = n; i < e; i++) + if (!strchr(VALID_CHARS, *i)) + return false; + + return true; +} + +char *unit_name_change_suffix(const char *n, const char *suffix) { + char *e, *r; + size_t a, b; + + assert(n); + assert(unit_name_is_valid(n)); + assert(suffix); + + assert_se(e = strrchr(n, '.')); + a = e - n; + b = strlen(suffix); + + if (!(r = new(char, a + b + 1))) + return NULL; + + memcpy(r, n, a); + memcpy(r+a, suffix, b+1); + + return r; +} + +Unit *unit_new(Manager *m) { + Unit *u; + + assert(m); + + if (!(u = new0(Unit, 1))) + return NULL; + + if (!(u->meta.names = set_new(string_hash_func, string_compare_func))) { + free(u); + return NULL; + } + + u->meta.manager = m; + u->meta.type = _UNIT_TYPE_INVALID; + + return u; +} + +int unit_add_name(Unit *u, const char *text) { + UnitType t; + char *s; + int r; + + assert(u); + assert(text); + + if (!unit_name_is_valid(text)) + return -EINVAL; + + if ((t = unit_name_to_type(text)) == _UNIT_TYPE_INVALID) + return -EINVAL; + + if (u->meta.type != _UNIT_TYPE_INVALID && t != u->meta.type) + return -EINVAL; + + if (!(s = strdup(text))) + return -ENOMEM; + + if ((r = set_put(u->meta.names, s)) < 0) { + free(s); + + if (r == -EEXIST) + return 0; + + return r; + } + + if ((r = hashmap_put(u->meta.manager->units, s, u)) < 0) { + set_remove(u->meta.names, s); + free(s); + return r; + } + + u->meta.type = t; + + if (!u->meta.id) + u->meta.id = s; + + return 0; +} + +void unit_add_to_load_queue(Unit *u) { + assert(u); + + if (u->meta.load_state != UNIT_STUB || u->meta.in_load_queue) + return; + + LIST_PREPEND(Meta, load_queue, u->meta.manager->load_queue, &u->meta); + u->meta.in_load_queue = true; +} + +static void bidi_set_free(Unit *u, Set *s) { + Iterator i; + Unit *other; + + assert(u); + + /* Frees the set and makes sure we are dropped from the + * inverse pointers */ + + SET_FOREACH(other, s, i) { + UnitDependency d; + + for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++) + set_remove(other->meta.dependencies[d], u); + } + + set_free(s); +} + +void unit_free(Unit *u) { + UnitDependency d; + Iterator i; + char *t; + + assert(u); + + /* Detach from next 'bigger' objects */ + + SET_FOREACH(t, u->meta.names, i) + hashmap_remove_value(u->meta.manager->units, t, u); + + if (u->meta.in_load_queue) + LIST_REMOVE(Meta, load_queue, u->meta.manager->load_queue, &u->meta); + + if (u->meta.load_state == UNIT_LOADED) + if (UNIT_VTABLE(u)->done) + UNIT_VTABLE(u)->done(u); + + /* Free data and next 'smaller' objects */ + if (u->meta.job) + job_free(u->meta.job); + + for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++) + bidi_set_free(u, u->meta.dependencies[d]); + + free(u->meta.description); + + while ((t = set_steal_first(u->meta.names))) + free(t); + set_free(u->meta.names); + + free(u); +} + +UnitActiveState unit_active_state(Unit *u) { + assert(u); + + if (u->meta.load_state != UNIT_LOADED) + return UNIT_INACTIVE; + + return UNIT_VTABLE(u)->active_state(u); +} + +static int ensure_merge(Set **s, Set *other) { + + if (!other) + return 0; + + if (*s) + return set_merge(*s, other); + + if (!(*s = set_copy(other))) + return -ENOMEM; + + return 0; +} + +/* FIXME: Does not rollback on failure! */ +int unit_merge(Unit *u, Unit *other) { + int r; + UnitDependency d; + + assert(u); + assert(other); + assert(u->meta.manager == other->meta.manager); + + /* This merges 'other' into 'unit'. FIXME: This does not + * rollback on failure. */ + + if (u->meta.type != u->meta.type) + return -EINVAL; + + if (u->meta.load_state != UNIT_STUB) + return -EINVAL; + + /* Merge names */ + if ((r = ensure_merge(&u->meta.names, other->meta.names)) < 0) + return r; + + /* Merge dependencies */ + for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++) + /* fixme, the inverse mapping is missing */ + if ((r = ensure_merge(&u->meta.dependencies[d], other->meta.dependencies[d])) < 0) + return r; + + return 0; +} + +const char* unit_id(Unit *u) { + assert(u); + + if (u->meta.id) + return u->meta.id; + + return set_first(u->meta.names); +} + +const char *unit_description(Unit *u) { + assert(u); + + if (u->meta.description) + return u->meta.description; + + return unit_id(u); +} + +void unit_dump(Unit *u, FILE *f, const char *prefix) { + + static const char* const load_state_table[_UNIT_LOAD_STATE_MAX] = { + [UNIT_STUB] = "stub", + [UNIT_LOADED] = "loaded", + [UNIT_FAILED] = "failed" + }; + + static const char* const active_state_table[_UNIT_ACTIVE_STATE_MAX] = { + [UNIT_ACTIVE] = "active", + [UNIT_INACTIVE] = "inactive", + [UNIT_ACTIVATING] = "activating", + [UNIT_DEACTIVATING] = "deactivating" + }; + + static const char* const dependency_table[_UNIT_DEPENDENCY_MAX] = { + [UNIT_REQUIRES] = "Requires", + [UNIT_SOFT_REQUIRES] = "SoftRequires", + [UNIT_WANTS] = "Wants", + [UNIT_REQUISITE] = "Requisite", + [UNIT_SOFT_REQUISITE] = "SoftRequisite", + [UNIT_REQUIRED_BY] = "RequiredBy", + [UNIT_SOFT_REQUIRED_BY] = "SoftRequiredBy", + [UNIT_WANTED_BY] = "WantedBy", + [UNIT_CONFLICTS] = "Conflicts", + [UNIT_BEFORE] = "Before", + [UNIT_AFTER] = "After", + }; + + char *t; + UnitDependency d; + Iterator i; + char *prefix2; + + assert(u); + + if (!prefix) + prefix = ""; + prefix2 = strappend(prefix, "\t"); + if (!prefix2) + prefix2 = ""; + + fprintf(f, + "%s→ Unit %s:\n" + "%s\tDescription: %s\n" + "%s\tUnit Load State: %s\n" + "%s\tUnit Active State: %s\n", + prefix, unit_id(u), + prefix, unit_description(u), + prefix, load_state_table[u->meta.load_state], + prefix, active_state_table[unit_active_state(u)]); + + SET_FOREACH(t, u->meta.names, i) + fprintf(f, "%s\tName: %s\n", prefix, t); + + for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++) { + Unit *other; + + if (set_isempty(u->meta.dependencies[d])) + continue; + + SET_FOREACH(other, u->meta.dependencies[d], i) + fprintf(f, "%s\t%s: %s\n", prefix, dependency_table[d], unit_id(other)); + } + + if (UNIT_VTABLE(u)->dump) + UNIT_VTABLE(u)->dump(u, f, prefix2); + + if (u->meta.job) + job_dump(u->meta.job, f, prefix2); + + free(prefix2); +} + +/* Common implementation for multiple backends */ +int unit_load_fragment_and_dropin(Unit *u) { + int r; + + assert(u); + + /* Load a .socket file */ + if ((r = unit_load_fragment(u)) < 0) + return r; + + /* Load drop-in directory data */ + if ((r = unit_load_dropin(u)) < 0) + return r; + + return 0; +} + +int unit_load(Unit *u) { + int r; + + assert(u); + + if (u->meta.in_load_queue) { + LIST_REMOVE(Meta, load_queue, u->meta.manager->load_queue, &u->meta); + u->meta.in_load_queue = false; + } + + if (u->meta.load_state != UNIT_STUB) + return 0; + + if (UNIT_VTABLE(u)->init) + if ((r = UNIT_VTABLE(u)->init(u)) < 0) + goto fail; + + u->meta.load_state = UNIT_LOADED; + return 0; + +fail: + u->meta.load_state = UNIT_FAILED; + return r; +} + +/* Errors: + * -EBADR: This unit type does not support starting. + * -EALREADY: Unit is already started. + * -EAGAIN: An operation is already in progress. Retry later. + */ +int unit_start(Unit *u) { + UnitActiveState state; + + assert(u); + + if (!UNIT_VTABLE(u)->start) + return -EBADR; + + state = unit_active_state(u); + if (UNIT_IS_ACTIVE_OR_RELOADING(state)) + return -EALREADY; + + /* We don't suppress calls to ->start() here when we are + * already starting, to allow this request to be used as a + * "hurry up" call, for example when the unit is in some "auto + * restart" state where it waits for a holdoff timer to elapse + * before it will start again. */ + + return UNIT_VTABLE(u)->start(u); +} + +bool unit_can_start(Unit *u) { + assert(u); + + return !!UNIT_VTABLE(u)->start; +} + +/* Errors: + * -EBADR: This unit type does not support stopping. + * -EALREADY: Unit is already stopped. + * -EAGAIN: An operation is already in progress. Retry later. + */ +int unit_stop(Unit *u) { + UnitActiveState state; + + assert(u); + + if (!UNIT_VTABLE(u)->stop) + return -EBADR; + + state = unit_active_state(u); + if (state == UNIT_INACTIVE) + return -EALREADY; + + if (state == UNIT_DEACTIVATING) + return 0; + + return UNIT_VTABLE(u)->stop(u); +} + +/* Errors: + * -EBADR: This unit type does not support reloading. + * -ENOEXEC: Unit is not started. + * -EAGAIN: An operation is already in progress. Retry later. + */ +int unit_reload(Unit *u) { + UnitActiveState state; + + assert(u); + + if (!unit_can_reload(u)) + return -EBADR; + + state = unit_active_state(u); + if (unit_active_state(u) == UNIT_ACTIVE_RELOADING) + return -EALREADY; + + if (unit_active_state(u) != UNIT_ACTIVE) + return -ENOEXEC; + + return UNIT_VTABLE(u)->reload(u); +} + +bool unit_can_reload(Unit *u) { + assert(u); + + if (!UNIT_VTABLE(u)->reload) + return false; + + if (!UNIT_VTABLE(u)->can_reload) + return true; + + return UNIT_VTABLE(u)->can_reload(u); +} + +static void retroactively_start_dependencies(Unit *u) { + Iterator i; + Unit *other; + + assert(u); + assert(UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u))); + + SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES], i) + if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other))) + manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL); + + SET_FOREACH(other, u->meta.dependencies[UNIT_SOFT_REQUIRES], i) + if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other))) + manager_add_job(u->meta.manager, JOB_START, other, JOB_FAIL, false, NULL); + + SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE], i) + if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other))) + manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL); + + SET_FOREACH(other, u->meta.dependencies[UNIT_WANTS], i) + if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other))) + manager_add_job(u->meta.manager, JOB_START, other, JOB_FAIL, false, NULL); + + SET_FOREACH(other, u->meta.dependencies[UNIT_CONFLICTS], i) + if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other))) + manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL); +} + +static void retroactively_stop_dependencies(Unit *u) { + Iterator i; + Unit *other; + + assert(u); + assert(UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(u))); + + SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY], i) + if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other))) + manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL); +} + +void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns) { + assert(u); + assert(os < _UNIT_ACTIVE_STATE_MAX); + assert(ns < _UNIT_ACTIVE_STATE_MAX); + assert(!(os == UNIT_ACTIVE && ns == UNIT_ACTIVATING)); + assert(!(os == UNIT_INACTIVE && ns == UNIT_DEACTIVATING)); + + if (os == ns) + return; + + if (!UNIT_IS_ACTIVE_OR_RELOADING(os) && UNIT_IS_ACTIVE_OR_RELOADING(ns)) + u->meta.active_enter_timestamp = now(CLOCK_REALTIME); + else if (UNIT_IS_ACTIVE_OR_RELOADING(os) && !UNIT_IS_ACTIVE_OR_RELOADING(ns)) + u->meta.active_exit_timestamp = now(CLOCK_REALTIME); + + if (u->meta.job) { + + if (u->meta.job->state == JOB_WAITING) + + /* So we reached a different state for this + * job. Let's see if we can run it now if it + * failed previously due to EAGAIN. */ + job_schedule_run(u->meta.job); + + else { + assert(u->meta.job->state == JOB_RUNNING); + + /* Let's check of this state change + * constitutes a finished job, or maybe + * cotradicts a running job and hence needs to + * invalidate jobs. */ + + switch (u->meta.job->type) { + + case JOB_START: + case JOB_VERIFY_ACTIVE: + + if (UNIT_IS_ACTIVE_OR_RELOADING(ns)) { + job_finish_and_invalidate(u->meta.job, true); + return; + } else if (ns == UNIT_ACTIVATING) + return; + else + job_finish_and_invalidate(u->meta.job, false); + + break; + + case JOB_RELOAD: + case JOB_RELOAD_OR_START: + + if (ns == UNIT_ACTIVE) { + job_finish_and_invalidate(u->meta.job, true); + return; + } else if (ns == UNIT_ACTIVATING || ns == UNIT_ACTIVE_RELOADING) + return; + else + job_finish_and_invalidate(u->meta.job, false); + + break; + + case JOB_STOP: + case JOB_RESTART: + case JOB_TRY_RESTART: + + if (ns == UNIT_INACTIVE) { + job_finish_and_invalidate(u->meta.job, true); + return; + } else if (ns == UNIT_DEACTIVATING) + return; + else + job_finish_and_invalidate(u->meta.job, false); + + break; + + default: + assert_not_reached("Job type unknown"); + } + } + } + + /* If this state change happened without being requested by a + * job, then let's retroactively start or stop dependencies */ + + if (UNIT_IS_INACTIVE_OR_DEACTIVATING(os) && UNIT_IS_ACTIVE_OR_ACTIVATING(ns)) + retroactively_start_dependencies(u); + else if (UNIT_IS_ACTIVE_OR_ACTIVATING(os) && UNIT_IS_INACTIVE_OR_DEACTIVATING(ns)) + retroactively_stop_dependencies(u); +} + +int unit_watch_fd(Unit *u, int fd, uint32_t events) { + struct epoll_event ev; + + assert(u); + assert(fd >= 0); + + zero(ev); + ev.data.fd = fd; + ev.data.ptr = u; + ev.data.u32 = MANAGER_FD; + ev.events = events; + + if (epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_ADD, fd, &ev) >= 0) + return 0; + + if (errno == EEXIST) + if (epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_MOD, fd, &ev) >= 0) + return 0; + + return -errno; +} + +void unit_unwatch_fd(Unit *u, int fd) { + assert(u); + assert(fd >= 0); + + assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, fd, NULL) >= 0 || errno == ENOENT); +} + +int unit_watch_pid(Unit *u, pid_t pid) { + assert(u); + assert(pid >= 1); + + return hashmap_put(u->meta.manager->watch_pids, UINT32_TO_PTR(pid), u); +} + +void unit_unwatch_pid(Unit *u, pid_t pid) { + assert(u); + assert(pid >= 1); + + hashmap_remove(u->meta.manager->watch_pids, UINT32_TO_PTR(pid)); +} + +int unit_watch_timer(Unit *u, usec_t delay, int *id) { + struct epoll_event ev; + int fd; + struct itimerspec its; + int flags; + bool ours; + + assert(u); + assert(id); + + /* This will try to reuse the old timer if there is one */ + + if (*id >= 0) { + ours = false; + fd = *id; + + } else { + ours = true; + + if ((fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK|TFD_CLOEXEC)) < 0) + return -errno; + } + + zero(its); + + if (delay <= 0) { + /* Set absolute time in the past, but not 0, since we + * don't want to disarm the timer */ + its.it_value.tv_sec = 0; + its.it_value.tv_nsec = 1; + + flags = TFD_TIMER_ABSTIME; + } else { + timespec_store(&its.it_value, delay); + flags = 0; + } + + /* This will also flush the elapse counter */ + if (timerfd_settime(fd, flags, &its, NULL) < 0) + goto fail; + + zero(ev); + ev.data.fd = fd; + ev.data.ptr = u; + ev.data.u32 = MANAGER_TIMER; + ev.events = POLLIN; + + if (epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0) + goto fail; + + *id = fd; + return 0; + +fail: + if (ours) + assert_se(close_nointr(fd) == 0); + + return -errno; +} + +void unit_unwatch_timer(Unit *u, int *id) { + assert(u); + assert(id); + + if (*id < 0) + return; + + assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, *id, NULL) >= 0); + assert_se(close_nointr(*id) == 0); + *id = -1; +} + +bool unit_job_is_applicable(Unit *u, JobType j) { + assert(u); + assert(j >= 0 && j < _JOB_TYPE_MAX); + + switch (j) { + + case JOB_VERIFY_ACTIVE: + case JOB_START: + return true; + + case JOB_STOP: + case JOB_RESTART: + case JOB_TRY_RESTART: + return unit_can_start(u); + + case JOB_RELOAD: + return unit_can_reload(u); + + case JOB_RELOAD_OR_START: + return unit_can_reload(u) && unit_can_start(u); + + default: + assert_not_reached("Invalid job type"); + } +} + +int unit_add_dependency(Unit *u, UnitDependency d, Unit *other) { + + static const UnitDependency inverse_table[_UNIT_DEPENDENCY_MAX] = { + [UNIT_REQUIRES] = UNIT_REQUIRED_BY, + [UNIT_SOFT_REQUIRES] = UNIT_SOFT_REQUIRED_BY, + [UNIT_WANTS] = UNIT_WANTED_BY, + [UNIT_REQUISITE] = UNIT_REQUIRED_BY, + [UNIT_SOFT_REQUISITE] = UNIT_SOFT_REQUIRED_BY, + [UNIT_REQUIRED_BY] = _UNIT_DEPENDENCY_INVALID, + [UNIT_SOFT_REQUIRED_BY] = _UNIT_DEPENDENCY_INVALID, + [UNIT_WANTED_BY] = _UNIT_DEPENDENCY_INVALID, + [UNIT_CONFLICTS] = UNIT_CONFLICTS, + [UNIT_BEFORE] = UNIT_AFTER, + [UNIT_AFTER] = UNIT_BEFORE + }; + int r; + + assert(u); + assert(d >= 0 && d < _UNIT_DEPENDENCY_MAX); + assert(inverse_table[d] != _UNIT_DEPENDENCY_INVALID); + assert(other); + + /* We won't allow dependencies on ourselves. We will not + * consider them an error however. */ + if (u == other) + return 0; + + if ((r = set_ensure_allocated(&u->meta.dependencies[d], trivial_hash_func, trivial_compare_func)) < 0) + return r; + + if ((r = set_ensure_allocated(&other->meta.dependencies[inverse_table[d]], trivial_hash_func, trivial_compare_func)) < 0) + return r; + + if ((r = set_put(u->meta.dependencies[d], other)) < 0) + return r; + + if ((r = set_put(other->meta.dependencies[inverse_table[d]], u)) < 0) { + set_remove(u->meta.dependencies[d], other); + return r; + } + + return 0; +} |