/*-*- Mode: C; c-basic-offset: 8 -*-*/ /*** This file is part of systemd. Copyright 2010 Lennart Poettering systemd is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ #include <assert.h> #include <errno.h> #include <string.h> #include <sys/epoll.h> #include <signal.h> #include <sys/signalfd.h> #include <sys/wait.h> #include <unistd.h> #include <sys/poll.h> #include <sys/reboot.h> #include <sys/ioctl.h> #include <linux/kd.h> #include <libcgroup.h> #include "manager.h" #include "hashmap.h" #include "macro.h" #include "strv.h" #include "log.h" #include "util.h" #include "ratelimit.h" #include "cgroup.h" #include "mount-setup.h" static int manager_setup_signals(Manager *m) { sigset_t mask; struct epoll_event ev; assert(m); assert_se(sigemptyset(&mask) == 0); assert_se(sigaddset(&mask, SIGCHLD) == 0); assert_se(sigaddset(&mask, SIGINT) == 0); /* Kernel sends us this on control-alt-del */ assert_se(sigaddset(&mask, SIGWINCH) == 0); /* Kernel sends us this on kbrequest (alt-arrowup) */ assert_se(sigaddset(&mask, SIGTERM) == 0); assert_se(sigaddset(&mask, SIGHUP) == 0); assert_se(sigaddset(&mask, SIGUSR1) == 0); assert_se(sigaddset(&mask, SIGUSR2) == 0); assert_se(sigaddset(&mask, SIGPIPE) == 0); assert_se(sigaddset(&mask, SIGPWR) == 0); assert_se(sigaddset(&mask, SIGTTIN) == 0); assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0); m->signal_watch.type = WATCH_SIGNAL; if ((m->signal_watch.fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0) return -errno; zero(ev); ev.events = EPOLLIN; ev.data.ptr = &m->signal_watch; if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->signal_watch.fd, &ev) < 0) return -errno; if (m->running_as == MANAGER_INIT) { /* Enable that we get SIGINT on control-alt-del */ if (reboot(RB_DISABLE_CAD) < 0) log_warning("Failed to enable ctrl-alt-del handling: %s", strerror(errno)); /* Enable that we get SIGWINCH on kbrequest */ if (ioctl(0, KDSIGACCEPT, SIGWINCH) < 0) log_warning("Failed to enable kbrequest handling: %s", strerror(errno)); } return 0; } static char** session_dirs(void) { const char *home, *e; char *config_home = NULL, *data_home = NULL; char **config_dirs = NULL, **data_dirs = NULL; char **r = NULL, **t; /* Implement the mechanisms defined in * * http://standards.freedesktop.org/basedir-spec/basedir-spec-0.6.html * * We look in both the config and the data dirs because we * want to encourage that distributors ship their unit files * as data, and allow overriding as configuration. */ home = getenv("HOME"); if ((e = getenv("XDG_CONFIG_HOME"))) { if (asprintf(&config_home, "%s/systemd/session", e) < 0) goto fail; } else if (home) { if (asprintf(&config_home, "%s/.config/systemd/session", home) < 0) goto fail; } if ((e = getenv("XDG_CONFIG_DIRS"))) config_dirs = strv_split(e, ":"); else config_dirs = strv_new("/etc/xdg", NULL); if (!config_dirs) goto fail; if ((e = getenv("XDG_DATA_HOME"))) { if (asprintf(&data_home, "%s/systemd/session", e) < 0) goto fail; } else if (home) { if (asprintf(&data_home, "%s/.local/share/systemd/session", home) < 0) goto fail; } if ((e = getenv("XDG_DATA_DIRS"))) data_dirs = strv_split(e, ":"); else data_dirs = strv_new("/usr/local/share", "/usr/share", NULL); if (!data_dirs) goto fail; /* Now merge everything we found. */ if (config_home) { if (!(t = strv_append(r, config_home))) goto fail; strv_free(r); r = t; } if (!(t = strv_merge_concat(r, config_dirs, "/systemd/session"))) goto finish; strv_free(r); r = t; if (!(t = strv_append(r, SESSION_CONFIG_UNIT_PATH))) goto fail; strv_free(r); r = t; if (data_home) { if (!(t = strv_append(r, data_home))) goto fail; strv_free(r); r = t; } if (!(t = strv_merge_concat(r, data_dirs, "/systemd/session"))) goto fail; strv_free(r); r = t; if (!(t = strv_append(r, SESSION_DATA_UNIT_PATH))) goto fail; strv_free(r); r = t; if (!strv_path_make_absolute_cwd(r)) goto fail; finish: free(config_home); strv_free(config_dirs); free(data_home); strv_free(data_dirs); return r; fail: strv_free(r); r = NULL; goto finish; } static int manager_find_paths(Manager *m) { const char *e; char *t; assert(m); /* First priority is whatever has been passed to us via env * vars */ if ((e = getenv("SYSTEMD_UNIT_PATH"))) if (!(m->unit_path = split_path_and_make_absolute(e))) return -ENOMEM; if (strv_isempty(m->unit_path)) { /* Nothing is set, so let's figure something out. */ strv_free(m->unit_path); if (m->running_as == MANAGER_SESSION) { if (!(m->unit_path = session_dirs())) return -ENOMEM; } else if (!(m->unit_path = strv_new( SYSTEM_CONFIG_UNIT_PATH, /* /etc/systemd/system/ */ SYSTEM_DATA_UNIT_PATH, /* /lib/systemd/system/ */ NULL))) return -ENOMEM; } if (m->running_as == MANAGER_INIT) { /* /etc/init.d/ compativility does not matter to users */ if ((e = getenv("SYSTEMD_SYSVINIT_PATH"))) if (!(m->sysvinit_path = split_path_and_make_absolute(e))) return -ENOMEM; if (strv_isempty(m->sysvinit_path)) { strv_free(m->sysvinit_path); if (!(m->sysvinit_path = strv_new( SYSTEM_SYSVINIT_PATH, /* /etc/init.d/ */ NULL))) return -ENOMEM; } } strv_uniq(m->unit_path); strv_uniq(m->sysvinit_path); assert(!strv_isempty(m->unit_path)); if (!(t = strv_join(m->unit_path, "\n\t"))) return -ENOMEM; log_debug("Looking for unit files in:\n\t%s", t); free(t); if (!strv_isempty(m->sysvinit_path)) { if (!(t = strv_join(m->sysvinit_path, "\n\t"))) return -ENOMEM; log_debug("Looking for SysV init scripts in:\n\t%s", t); free(t); } else log_debug("Ignoring SysV init scripts."); return 0; } int manager_new(Manager **_m) { Manager *m; int r = -ENOMEM; assert(_m); if (!(m = new0(Manager, 1))) return -ENOMEM; m->signal_watch.fd = m->mount_watch.fd = m->udev_watch.fd = m->epoll_fd = -1; m->current_job_id = 1; /* start as id #1, so that we can leave #0 around as "null-like" value */ if (!(m->units = hashmap_new(string_hash_func, string_compare_func))) goto fail; if (!(m->jobs = hashmap_new(trivial_hash_func, trivial_compare_func))) goto fail; if (!(m->transaction_jobs = hashmap_new(trivial_hash_func, trivial_compare_func))) goto fail; if (!(m->watch_pids = hashmap_new(trivial_hash_func, trivial_compare_func))) goto fail; if (!(m->cgroup_bondings = hashmap_new(string_hash_func, string_compare_func))) goto fail; if ((m->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0) goto fail; if (getpid() == 1) m->running_as = MANAGER_INIT; else if (getuid() == 0) m->running_as = MANAGER_SYSTEM; else m->running_as = MANAGER_SESSION; log_debug("systemd running in %s mode.", manager_running_as_to_string(m->running_as)); if ((r = manager_find_paths(m)) < 0) goto fail; if ((r = manager_setup_signals(m)) < 0) goto fail; if ((r = manager_setup_cgroup(m)) < 0) goto fail; /* Try to connect to the busses, if possible. */ if ((r = bus_init_system(m)) < 0 || (r = bus_init_api(m)) < 0) goto fail; *_m = m; return 0; fail: manager_free(m); return r; } static unsigned manager_dispatch_cleanup_queue(Manager *m) { Meta *meta; unsigned n = 0; assert(m); while ((meta = m->cleanup_queue)) { assert(meta->in_cleanup_queue); unit_free(UNIT(meta)); n++; } return n; } void manager_free(Manager *m) { UnitType c; Unit *u; Job *j; assert(m); while ((j = hashmap_first(m->transaction_jobs))) job_free(j); while ((u = hashmap_first(m->units))) unit_free(u); manager_dispatch_cleanup_queue(m); for (c = 0; c < _UNIT_TYPE_MAX; c++) if (unit_vtable[c]->shutdown) unit_vtable[c]->shutdown(m); manager_shutdown_cgroup(m); bus_done_api(m); bus_done_system(m); hashmap_free(m->units); hashmap_free(m->jobs); hashmap_free(m->transaction_jobs); hashmap_free(m->watch_pids); if (m->epoll_fd >= 0) close_nointr(m->epoll_fd); if (m->signal_watch.fd >= 0) close_nointr(m->signal_watch.fd); strv_free(m->unit_path); strv_free(m->sysvinit_path); free(m->cgroup_controller); free(m->cgroup_hierarchy); assert(hashmap_isempty(m->cgroup_bondings)); hashmap_free(m->cgroup_bondings); free(m); } int manager_coldplug(Manager *m) { int r; UnitType c; Iterator i; Unit *u; char *k; assert(m); /* First, let's ask every type to load all units from * disk/kernel that it might know */ for (c = 0; c < _UNIT_TYPE_MAX; c++) if (unit_vtable[c]->enumerate) if ((r = unit_vtable[c]->enumerate(m)) < 0) return r; manager_dispatch_load_queue(m); /* Then, let's set up their initial state. */ HASHMAP_FOREACH_KEY(u, k, m->units, i) { /* ignore aliases */ if (unit_id(u) != k) continue; if (UNIT_VTABLE(u)->coldplug) if ((r = UNIT_VTABLE(u)->coldplug(u)) < 0) return r; } return 0; } static void transaction_delete_job(Manager *m, Job *j, bool delete_dependencies) { assert(m); assert(j); /* Deletes one job from the transaction */ manager_transaction_unlink_job(m, j, delete_dependencies); if (!j->installed) job_free(j); } static void transaction_delete_unit(Manager *m, Unit *u) { Job *j; /* Deletes all jobs associated with a certain unit from the * transaction */ while ((j = hashmap_get(m->transaction_jobs, u))) transaction_delete_job(m, j, true); } static void transaction_clean_dependencies(Manager *m) { Iterator i; Job *j; assert(m); /* Drops all dependencies of all installed jobs */ HASHMAP_FOREACH(j, m->jobs, i) { while (j->subject_list) job_dependency_free(j->subject_list); while (j->object_list) job_dependency_free(j->object_list); } assert(!m->transaction_anchor); } static void transaction_abort(Manager *m) { Job *j; assert(m); while ((j = hashmap_first(m->transaction_jobs))) if (j->installed) transaction_delete_job(m, j, true); else job_free(j); assert(hashmap_isempty(m->transaction_jobs)); transaction_clean_dependencies(m); } static void transaction_find_jobs_that_matter_to_anchor(Manager *m, Job *j, unsigned generation) { JobDependency *l; assert(m); /* A recursive sweep through the graph that marks all units * that matter to the anchor job, i.e. are directly or * indirectly a dependency of the anchor job via paths that * are fully marked as mattering. */ if (j) l = j->subject_list; else l = m->transaction_anchor; LIST_FOREACH(subject, l, l) { /* This link does not matter */ if (!l->matters) continue; /* This unit has already been marked */ if (l->object->generation == generation) continue; l->object->matters_to_anchor = true; l->object->generation = generation; transaction_find_jobs_that_matter_to_anchor(m, l->object, generation); } } static void transaction_merge_and_delete_job(Manager *m, Job *j, Job *other, JobType t) { JobDependency *l, *last; assert(j); assert(other); assert(j->unit == other->unit); assert(!j->installed); /* Merges 'other' into 'j' and then deletes j. */ j->type = t; j->state = JOB_WAITING; j->forced = j->forced || other->forced; j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor; /* Patch us in as new owner of the JobDependency objects */ last = NULL; LIST_FOREACH(subject, l, other->subject_list) { assert(l->subject == other); l->subject = j; last = l; } /* Merge both lists */ if (last) { last->subject_next = j->subject_list; if (j->subject_list) j->subject_list->subject_prev = last; j->subject_list = other->subject_list; } /* Patch us in as new owner of the JobDependency objects */ last = NULL; LIST_FOREACH(object, l, other->object_list) { assert(l->object == other); l->object = j; last = l; } /* Merge both lists */ if (last) { last->object_next = j->object_list; if (j->object_list) j->object_list->object_prev = last; j->object_list = other->object_list; } /* Kill the other job */ other->subject_list = NULL; other->object_list = NULL; transaction_delete_job(m, other, true); } static int delete_one_unmergeable_job(Manager *m, Job *j) { Job *k; assert(j); /* Tries to delete one item in the linked list * j->transaction_next->transaction_next->... that conflicts * whith another one, in an attempt to make an inconsistent * transaction work. */ /* We rely here on the fact that if a merged with b does not * merge with c, either a or b merge with c neither */ LIST_FOREACH(transaction, j, j) LIST_FOREACH(transaction, k, j->transaction_next) { Job *d; /* Is this one mergeable? Then skip it */ if (job_type_is_mergeable(j->type, k->type)) continue; /* Ok, we found two that conflict, let's see if we can * drop one of them */ if (!j->matters_to_anchor) d = j; else if (!k->matters_to_anchor) d = k; else return -ENOEXEC; /* Ok, we can drop one, so let's do so. */ log_debug("Trying to fix job merging by deleting job %s/%s", unit_id(d->unit), job_type_to_string(d->type)); transaction_delete_job(m, d, true); return 0; } return -EINVAL; } static int transaction_merge_jobs(Manager *m) { Job *j; Iterator i; int r; assert(m); /* First step, check whether any of the jobs for one specific * task conflict. If so, try to drop one of them. */ HASHMAP_FOREACH(j, m->transaction_jobs, i) { JobType t; Job *k; t = j->type; LIST_FOREACH(transaction, k, j->transaction_next) { if ((r = job_type_merge(&t, k->type)) >= 0) continue; /* OK, we could not merge all jobs for this * action. Let's see if we can get rid of one * of them */ if ((r = delete_one_unmergeable_job(m, j)) >= 0) /* Ok, we managed to drop one, now * let's ask our callers to call us * again after garbage collecting */ return -EAGAIN; /* We couldn't merge anything. Failure */ return r; } } /* Second step, merge the jobs. */ HASHMAP_FOREACH(j, m->transaction_jobs, i) { JobType t = j->type; Job *k; /* Merge all transactions */ LIST_FOREACH(transaction, k, j->transaction_next) assert_se(job_type_merge(&t, k->type) == 0); /* If an active job is mergeable, merge it too */ if (j->unit->meta.job) job_type_merge(&t, j->unit->meta.job->type); /* Might fail. Which is OK */ while ((k = j->transaction_next)) { if (j->installed) { transaction_merge_and_delete_job(m, k, j, t); j = k; } else transaction_merge_and_delete_job(m, j, k, t); } assert(!j->transaction_next); assert(!j->transaction_prev); } return 0; } static void transaction_drop_redundant(Manager *m) { bool again; assert(m); /* Goes through the transaction and removes all jobs that are * a noop */ do { Job *j; Iterator i; again = false; HASHMAP_FOREACH(j, m->transaction_jobs, i) { bool changes_something = false; Job *k; LIST_FOREACH(transaction, k, j) { if (!job_is_anchor(k) && job_type_is_redundant(k->type, unit_active_state(k->unit))) continue; changes_something = true; break; } if (changes_something) continue; log_debug("Found redundant job %s/%s, dropping.", unit_id(j->unit), job_type_to_string(j->type)); transaction_delete_job(m, j, false); again = true; break; } } while (again); } static bool unit_matters_to_anchor(Unit *u, Job *j) { assert(u); assert(!j->transaction_prev); /* Checks whether at least one of the jobs for this unit * matters to the anchor. */ LIST_FOREACH(transaction, j, j) if (j->matters_to_anchor) return true; return false; } static int transaction_verify_order_one(Manager *m, Job *j, Job *from, unsigned generation) { Iterator i; Unit *u; int r; assert(m); assert(j); assert(!j->transaction_prev); /* Does a recursive sweep through the ordering graph, looking * for a cycle. If we find cycle we try to break it. */ /* Did we find a cycle? */ if (j->marker && j->generation == generation) { Job *k; /* So, we already have been here. We have a * cycle. Let's try to break it. We go backwards in * our path and try to find a suitable job to * remove. We use the marker to find our way back, * since smart how we are we stored our way back in * there. */ log_debug("Found ordering cycle on %s/%s", unit_id(j->unit), job_type_to_string(j->type)); for (k = from; k; k = (k->generation == generation ? k->marker : NULL)) { log_debug("Walked on cycle path to %s/%s", unit_id(k->unit), job_type_to_string(k->type)); if (!k->installed && !unit_matters_to_anchor(k->unit, k)) { /* Ok, we can drop this one, so let's * do so. */ log_debug("Breaking order cycle by deleting job %s/%s", unit_id(k->unit), job_type_to_string(k->type)); transaction_delete_unit(m, k->unit); return -EAGAIN; } /* Check if this in fact was the beginning of * the cycle */ if (k == j) break; } log_debug("Unable to break cycle"); return -ENOEXEC; } /* Make the marker point to where we come from, so that we can * find our way backwards if we want to break a cycle */ j->marker = from; j->generation = generation; /* We assume that the the dependencies are bidirectional, and * hence can ignore UNIT_AFTER */ SET_FOREACH(u, j->unit->meta.dependencies[UNIT_BEFORE], i) { Job *o; /* Is there a job for this unit? */ if (!(o = hashmap_get(m->transaction_jobs, u))) /* Ok, there is no job for this in the * transaction, but maybe there is already one * running? */ if (!(o = u->meta.job)) continue; if ((r = transaction_verify_order_one(m, o, j, generation)) < 0) return r; } /* Ok, let's backtrack, and remember that this entry is not on * our path anymore. */ j->marker = NULL; return 0; } static int transaction_verify_order(Manager *m, unsigned *generation) { Job *j; int r; Iterator i; assert(m); assert(generation); /* Check if the ordering graph is cyclic. If it is, try to fix * that up by dropping one of the jobs. */ HASHMAP_FOREACH(j, m->transaction_jobs, i) if ((r = transaction_verify_order_one(m, j, NULL, (*generation)++)) < 0) return r; return 0; } static void transaction_collect_garbage(Manager *m) { bool again; assert(m); /* Drop jobs that are not required by any other job */ do { Iterator i; Job *j; again = false; HASHMAP_FOREACH(j, m->transaction_jobs, i) { if (j->object_list) continue; log_debug("Garbage collecting job %s/%s", unit_id(j->unit), job_type_to_string(j->type)); transaction_delete_job(m, j, true); again = true; break; } } while (again); } static int transaction_is_destructive(Manager *m, JobMode mode) { Iterator i; Job *j; assert(m); /* Checks whether applying this transaction means that * existing jobs would be replaced */ HASHMAP_FOREACH(j, m->transaction_jobs, i) { /* Assume merged */ assert(!j->transaction_prev); assert(!j->transaction_next); if (j->unit->meta.job && j->unit->meta.job != j && !job_type_is_superset(j->type, j->unit->meta.job->type)) return -EEXIST; } return 0; } static void transaction_minimize_impact(Manager *m) { bool again; assert(m); /* Drops all unnecessary jobs that reverse already active jobs * or that stop a running service. */ do { Job *j; Iterator i; again = false; HASHMAP_FOREACH(j, m->transaction_jobs, i) { LIST_FOREACH(transaction, j, j) { bool stops_running_service, changes_existing_job; /* If it matters, we shouldn't drop it */ if (j->matters_to_anchor) continue; /* Would this stop a running service? * Would this change an existing job? * If so, let's drop this entry */ stops_running_service = j->type == JOB_STOP && UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(j->unit)); changes_existing_job = j->unit->meta.job && job_type_is_conflicting(j->type, j->unit->meta.job->state); if (!stops_running_service && !changes_existing_job) continue; if (stops_running_service) log_debug("%s/%s would stop a running service.", unit_id(j->unit), job_type_to_string(j->type)); if (changes_existing_job) log_debug("%s/%s would change existing job.", unit_id(j->unit), job_type_to_string(j->type)); /* Ok, let's get rid of this */ log_debug("Deleting %s/%s to minimize impact.", unit_id(j->unit), job_type_to_string(j->type)); transaction_delete_job(m, j, true); again = true; break; } if (again) break; } } while (again); } static int transaction_apply(Manager *m, JobMode mode) { Iterator i; Job *j; int r; /* Moves the transaction jobs to the set of active jobs */ HASHMAP_FOREACH(j, m->transaction_jobs, i) { /* Assume merged */ assert(!j->transaction_prev); assert(!j->transaction_next); if (j->installed) continue; if ((r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j)) < 0) goto rollback; } while ((j = hashmap_steal_first(m->transaction_jobs))) { if (j->installed) continue; if (j->unit->meta.job) job_free(j->unit->meta.job); j->unit->meta.job = j; j->installed = true; /* We're fully installed. Now let's free data we don't * need anymore. */ assert(!j->transaction_next); assert(!j->transaction_prev); job_add_to_run_queue(j); job_add_to_dbus_queue(j); } /* As last step, kill all remaining job dependencies. */ transaction_clean_dependencies(m); return 0; rollback: HASHMAP_FOREACH(j, m->transaction_jobs, i) { if (j->installed) continue; hashmap_remove(m->jobs, UINT32_TO_PTR(j->id)); } return r; } static int transaction_activate(Manager *m, JobMode mode) { int r; unsigned generation = 1; assert(m); /* This applies the changes recorded in transaction_jobs to * the actual list of jobs, if possible. */ /* First step: figure out which jobs matter */ transaction_find_jobs_that_matter_to_anchor(m, NULL, generation++); /* Second step: Try not to stop any running services if * we don't have to. Don't try to reverse running * jobs if we don't have to. */ transaction_minimize_impact(m); /* Third step: Drop redundant jobs */ transaction_drop_redundant(m); for (;;) { /* Fourth step: Let's remove unneeded jobs that might * be lurking. */ transaction_collect_garbage(m); /* Fifth step: verify order makes sense and correct * cycles if necessary and possible */ if ((r = transaction_verify_order(m, &generation)) >= 0) break; if (r != -EAGAIN) { log_debug("Requested transaction contains an unfixable cyclic ordering dependency: %s", strerror(-r)); goto rollback; } /* Let's see if the resulting transaction ordering * graph is still cyclic... */ } for (;;) { /* Sixth step: let's drop unmergeable entries if * necessary and possible, merge entries we can * merge */ if ((r = transaction_merge_jobs(m)) >= 0) break; if (r != -EAGAIN) { log_debug("Requested transaction contains unmergable jobs: %s", strerror(-r)); goto rollback; } /* Seventh step: an entry got dropped, let's garbage * collect its dependencies. */ transaction_collect_garbage(m); /* Let's see if the resulting transaction still has * unmergeable entries ... */ } /* Eights step: Drop redundant jobs again, if the merging now allows us to drop more. */ transaction_drop_redundant(m); /* Ninth step: check whether we can actually apply this */ if (mode == JOB_FAIL) if ((r = transaction_is_destructive(m, mode)) < 0) { log_debug("Requested transaction contradicts existing jobs: %s", strerror(-r)); goto rollback; } /* Tenth step: apply changes */ if ((r = transaction_apply(m, mode)) < 0) { log_debug("Failed to apply transaction: %s", strerror(-r)); goto rollback; } assert(hashmap_isempty(m->transaction_jobs)); assert(!m->transaction_anchor); return 0; rollback: transaction_abort(m); return r; } static Job* transaction_add_one_job(Manager *m, JobType type, Unit *unit, bool force, bool *is_new) { Job *j, *f; int r; assert(m); assert(unit); /* Looks for an axisting prospective job and returns that. If * it doesn't exist it is created and added to the prospective * jobs list. */ f = hashmap_get(m->transaction_jobs, unit); LIST_FOREACH(transaction, j, f) { assert(j->unit == unit); if (j->type == type) { if (is_new) *is_new = false; return j; } } if (unit->meta.job && unit->meta.job->type == type) j = unit->meta.job; else if (!(j = job_new(m, type, unit))) return NULL; j->generation = 0; j->marker = NULL; j->matters_to_anchor = false; j->forced = force; LIST_PREPEND(Job, transaction, f, j); if ((r = hashmap_replace(m->transaction_jobs, unit, f)) < 0) { job_free(j); return NULL; } if (is_new) *is_new = true; log_debug("Added job %s/%s to transaction.", unit_id(unit), job_type_to_string(type)); return j; } void manager_transaction_unlink_job(Manager *m, Job *j, bool delete_dependencies) { assert(m); assert(j); if (j->transaction_prev) j->transaction_prev->transaction_next = j->transaction_next; else if (j->transaction_next) hashmap_replace(m->transaction_jobs, j->unit, j->transaction_next); else hashmap_remove_value(m->transaction_jobs, j->unit, j); if (j->transaction_next) j->transaction_next->transaction_prev = j->transaction_prev; j->transaction_prev = j->transaction_next = NULL; while (j->subject_list) job_dependency_free(j->subject_list); while (j->object_list) { Job *other = j->object_list->matters ? j->object_list->subject : NULL; job_dependency_free(j->object_list); if (other && delete_dependencies) { log_debug("Deleting job %s/%s as dependency of job %s/%s", unit_id(other->unit), job_type_to_string(other->type), unit_id(j->unit), job_type_to_string(j->type)); transaction_delete_job(m, other, delete_dependencies); } } } static int transaction_add_job_and_dependencies(Manager *m, JobType type, Unit *unit, Job *by, bool matters, bool force, Job **_ret) { Job *ret; Iterator i; Unit *dep; int r; bool is_new; assert(m); assert(type < _JOB_TYPE_MAX); assert(unit); if (unit->meta.load_state != UNIT_LOADED) return -EINVAL; if (!unit_job_is_applicable(unit, type)) return -EBADR; /* First add the job. */ if (!(ret = transaction_add_one_job(m, type, unit, force, &is_new))) return -ENOMEM; /* Then, add a link to the job. */ if (!job_dependency_new(by, ret, matters)) return -ENOMEM; if (is_new) { /* Finally, recursively add in all dependencies. */ if (type == JOB_START || type == JOB_RELOAD_OR_START) { SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES], i) if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, true, force, NULL)) < 0 && r != -EBADR) goto fail; SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_SOFT_REQUIRES], i) if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, !force, force, NULL)) < 0 && r != -EBADR) goto fail; SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_WANTS], i) if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, false, force, NULL)) < 0) log_warning("Cannot add dependency job for unit %s, ignoring: %s", unit_id(dep), strerror(-r)); SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE], i) if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, true, force, NULL)) < 0 && r != -EBADR) goto fail; SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_SOFT_REQUISITE], i) if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, !force, force, NULL)) < 0 && r != -EBADR) goto fail; SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_CONFLICTS], i) if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, force, NULL)) < 0 && r != -EBADR) goto fail; } else if (type == JOB_STOP || type == JOB_RESTART || type == JOB_TRY_RESTART) { SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRED_BY], i) if ((r = transaction_add_job_and_dependencies(m, type, dep, ret, true, force, NULL)) < 0 && r != -EBADR) goto fail; } /* JOB_VERIFY_STARTED, JOB_RELOAD require no dependency handling */ } if (_ret) *_ret = ret; return 0; fail: return r; } int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool force, Job **_ret) { int r; Job *ret; assert(m); assert(type < _JOB_TYPE_MAX); assert(unit); assert(mode < _JOB_MODE_MAX); log_debug("Trying to enqueue job %s/%s", unit_id(unit), job_type_to_string(type)); if ((r = transaction_add_job_and_dependencies(m, type, unit, NULL, true, force, &ret)) < 0) { transaction_abort(m); return r; } if ((r = transaction_activate(m, mode)) < 0) return r; log_debug("Enqueued job %s/%s as %u", unit_id(unit), job_type_to_string(type), (unsigned) ret->id); if (_ret) *_ret = ret; return 0; } Job *manager_get_job(Manager *m, uint32_t id) { assert(m); return hashmap_get(m->jobs, UINT32_TO_PTR(id)); } Unit *manager_get_unit(Manager *m, const char *name) { assert(m); assert(name); return hashmap_get(m->units, name); } unsigned manager_dispatch_load_queue(Manager *m) { Meta *meta; unsigned n = 0; assert(m); /* Make sure we are not run recursively */ if (m->dispatching_load_queue) return 0; m->dispatching_load_queue = true; /* Dispatches the load queue. Takes a unit from the queue and * tries to load its data until the queue is empty */ while ((meta = m->load_queue)) { assert(meta->in_load_queue); unit_load(UNIT(meta)); n++; } m->dispatching_load_queue = false; return n; } int manager_load_unit(Manager *m, const char *path, Unit **_ret) { Unit *ret; int r; const char *name; assert(m); assert(path); assert(_ret); /* This will load the service information files, but not actually * start any services or anything. */ name = file_name_from_path(path); if ((ret = manager_get_unit(m, name))) { *_ret = ret; return 0; } if (!(ret = unit_new(m))) return -ENOMEM; if (is_path(path)) { if (!(ret->meta.fragment_path = strdup(path))) { unit_free(ret); return -ENOMEM; } } if ((r = unit_add_name(ret, name)) < 0) { unit_free(ret); return r; } unit_add_to_load_queue(ret); unit_add_to_dbus_queue(ret); manager_dispatch_load_queue(m); *_ret = unit_follow_merge(ret); return 0; } void manager_dump_jobs(Manager *s, FILE *f, const char *prefix) { Iterator i; Job *j; assert(s); assert(f); HASHMAP_FOREACH(j, s->jobs, i) job_dump(j, f, prefix); } void manager_dump_units(Manager *s, FILE *f, const char *prefix) { Iterator i; Unit *u; const char *t; assert(s); assert(f); HASHMAP_FOREACH_KEY(u, t, s->units, i) if (unit_id(u) == t) unit_dump(u, f, prefix); } void manager_clear_jobs(Manager *m) { Job *j; assert(m); transaction_abort(m); while ((j = hashmap_first(m->jobs))) job_free(j); } unsigned manager_dispatch_run_queue(Manager *m) { Job *j; unsigned n = 0; if (m->dispatching_run_queue) return 0; m->dispatching_run_queue = true; while ((j = m->run_queue)) { assert(j->installed); assert(j->in_run_queue); job_run_and_invalidate(j); n++; } m->dispatching_run_queue = false; return n; } unsigned manager_dispatch_dbus_queue(Manager *m) { Job *j; Meta *meta; unsigned n = 0; assert(m); if (m->dispatching_dbus_queue) return 0; m->dispatching_dbus_queue = true; while ((meta = m->dbus_unit_queue)) { assert(meta->in_dbus_queue); bus_unit_send_change_signal(UNIT(meta)); n++; } while ((j = m->dbus_job_queue)) { assert(j->in_dbus_queue); bus_job_send_change_signal(j); n++; } m->dispatching_dbus_queue = false; return n; } static int manager_dispatch_sigchld(Manager *m) { assert(m); log_debug("dispatching SIGCHLD"); for (;;) { siginfo_t si; Unit *u; zero(si); if (waitid(P_ALL, 0, &si, WEXITED|WNOHANG) < 0) { if (errno == ECHILD) break; return -errno; } if (si.si_pid == 0) break; if (si.si_code != CLD_EXITED && si.si_code != CLD_KILLED && si.si_code != CLD_DUMPED) continue; log_debug("child %llu died (code=%s, status=%i)", (long long unsigned) si.si_pid, sigchld_code_to_string(si.si_code), si.si_status); if (!(u = hashmap_remove(m->watch_pids, UINT32_TO_PTR(si.si_pid)))) continue; UNIT_VTABLE(u)->sigchld_event(u, si.si_pid, si.si_code, si.si_status); } return 0; } static int manager_process_signal_fd(Manager *m, bool *quit) { ssize_t n; struct signalfd_siginfo sfsi; bool sigchld = false; assert(m); for (;;) { if ((n = read(m->signal_watch.fd, &sfsi, sizeof(sfsi))) != sizeof(sfsi)) { if (n >= 0) return -EIO; if (errno == EAGAIN) break; return -errno; } switch (sfsi.ssi_signo) { case SIGCHLD: sigchld = true; break; case SIGINT: case SIGTERM: if (m->running_as != MANAGER_INIT) { *quit = true; return 0; } else { Unit *target; int r; if ((r = manager_load_unit(m, SPECIAL_CTRL_ALT_DEL_TARGET, &target)) < 0) log_error("Failed to load ctrl-alt-del target: %s", strerror(-r)); else if ((r = manager_add_job(m, JOB_START, target, JOB_REPLACE, true, NULL)) < 0) log_error("Failed to enqueue ctrl-alt-del job: %s", strerror(-r)); break; } case SIGWINCH: if (m->running_as == MANAGER_INIT) { Unit *target; int r; if ((r = manager_load_unit(m, SPECIAL_KBREQUEST_TARGET, &target)) < 0) log_error("Failed to load kbrequest target: %s", strerror(-r)); else if ((r = manager_add_job(m, JOB_START, target, JOB_REPLACE, true, NULL)) < 0) log_error("Failed to enqueue kbrequest job: %s", strerror(-r)); break; } /* This is a nop on non-init systemd's */ break; case SIGUSR1: printf("→ By units:\n"); manager_dump_units(m, stdout, "\t"); printf("→ By jobs:\n"); manager_dump_jobs(m, stdout, "\t"); break; default: log_info("Got unhandled signal <%s>.", strsignal(sfsi.ssi_signo)); } } if (sigchld) return manager_dispatch_sigchld(m); return 0; } static int process_event(Manager *m, struct epoll_event *ev, bool *quit) { int r; Watch *w; assert(m); assert(ev); assert(w = ev->data.ptr); switch (w->type) { case WATCH_SIGNAL: /* An incoming signal? */ if (ev->events != EPOLLIN) return -EINVAL; if ((r = manager_process_signal_fd(m, quit)) < 0) return r; break; case WATCH_FD: /* Some fd event, to be dispatched to the units */ UNIT_VTABLE(w->data.unit)->fd_event(w->data.unit, w->fd, ev->events, w); break; case WATCH_TIMER: { uint64_t v; ssize_t k; /* Some timer event, to be dispatched to the units */ if ((k = read(w->fd, &v, sizeof(v))) != sizeof(v)) { if (k < 0 && (errno == EINTR || errno == EAGAIN)) break; return k < 0 ? -errno : -EIO; } UNIT_VTABLE(w->data.unit)->timer_event(w->data.unit, v, w); break; } case WATCH_MOUNT: /* Some mount table change, intended for the mount subsystem */ mount_fd_event(m, ev->events); break; case WATCH_UDEV: /* Some notification from udev, intended for the device subsystem */ device_fd_event(m, ev->events); break; case WATCH_DBUS_WATCH: bus_watch_event(m, w, ev->events); break; case WATCH_DBUS_TIMEOUT: bus_timeout_event(m, w, ev->events); break; default: assert_not_reached("Unknown epoll event type."); } return 0; } int manager_loop(Manager *m) { int r; bool quit = false; RATELIMIT_DEFINE(rl, 1*USEC_PER_SEC, 1000); assert(m); do { struct epoll_event event; int n; if (!ratelimit_test(&rl)) { /* Yay, something is going seriously wrong, pause a little */ log_warning("Looping too fast. Throttling execution a little."); sleep(1); } if (manager_dispatch_cleanup_queue(m) > 0) continue; if (manager_dispatch_load_queue(m) > 0) continue; if (manager_dispatch_run_queue(m) > 0) continue; if (bus_dispatch(m) > 0) continue; if (manager_dispatch_dbus_queue(m) > 0) continue; if ((n = epoll_wait(m->epoll_fd, &event, 1, -1)) < 0) { if (errno == -EINTR) continue; return -errno; } assert(n == 1); if ((r = process_event(m, &event, &quit)) < 0) return r; } while (!quit); return 0; } int manager_get_unit_from_dbus_path(Manager *m, const char *s, Unit **_u) { char *n; Unit *u; assert(m); assert(s); assert(_u); if (!startswith(s, "/org/freedesktop/systemd1/unit/")) return -EINVAL; if (!(n = bus_path_unescape(s+31))) return -ENOMEM; u = manager_get_unit(m, n); free(n); if (!u) return -ENOENT; *_u = u; return 0; } int manager_get_job_from_dbus_path(Manager *m, const char *s, Job **_j) { Job *j; unsigned id; int r; assert(m); assert(s); assert(_j); if (!startswith(s, "/org/freedesktop/systemd1/job/")) return -EINVAL; if ((r = safe_atou(s + 30, &id)) < 0) return r; if (!(j = manager_get_job(m, id))) return -ENOENT; *_j = j; return 0; } static const char* const manager_running_as_table[_MANAGER_RUNNING_AS_MAX] = { [MANAGER_INIT] = "init", [MANAGER_SYSTEM] = "system", [MANAGER_SESSION] = "session" }; DEFINE_STRING_TABLE_LOOKUP(manager_running_as, ManagerRunningAs);