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Systemd/name.c

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/*-*- 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 "name.h"
#include "macro.h"
#include "strv.h"
#include "load-fragment.h"
#include "load-dropin.h"
#include "log.h"
const NameVTable * const name_vtable[_NAME_TYPE_MAX] = {
[NAME_SERVICE] = &service_vtable,
[NAME_TIMER] = &timer_vtable,
[NAME_SOCKET] = &socket_vtable,
[NAME_TARGET] = &target_vtable,
[NAME_DEVICE] = &device_vtable,
[NAME_MOUNT] = &mount_vtable,
[NAME_AUTOMOUNT] = &automount_vtable,
[NAME_SNAPSHOT] = &snapshot_vtable
};
NameType name_type_from_string(const char *n) {
NameType t;
assert(n);
for (t = 0; t < _NAME_TYPE_MAX; t++)
if (endswith(n, name_vtable[t]->suffix))
return t;
return _NAME_TYPE_INVALID;
}
#define VALID_CHARS \
"0123456789" \
"abcdefghijklmnopqrstuvwxyz" \
"ABCDEFGHIJKLMNOPQRSTUVWXYZ" \
"-_"
bool name_is_valid(const char *n) {
NameType t;
const char *e, *i;
assert(n);
if (strlen(n) >= NAME_MAX)
return false;
t = name_type_from_string(n);
if (t < 0 || t >= _NAME_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;
}
Name *name_new(Manager *m) {
Name *n;
assert(m);
if (!(n = new0(Name, 1)))
return NULL;
if (!(n->meta.names = set_new(string_hash_func, string_compare_func))) {
free(n);
return NULL;
}
n->meta.manager = m;
n->meta.type = _NAME_TYPE_INVALID;
return n;
}
int name_add_name(Name *n, const char *text) {
NameType t;
char *s;
int r;
assert(n);
assert(text);
if ((t = name_type_from_string(text)) == _NAME_TYPE_INVALID)
return -EINVAL;
if (n->meta.type != _NAME_TYPE_INVALID && t != n->meta.type)
return -EINVAL;
if (!(s = strdup(text)))
return -ENOMEM;
if ((r = set_put(n->meta.names, s)) < 0) {
free(s);
return r;
}
if ((r = hashmap_put(n->meta.manager->names, s, n)) < 0) {
set_remove(n->meta.names, s);
free(s);
return r;
}
n->meta.type = t;
if (!n->meta.id)
n->meta.id = s;
return 0;
}
void name_add_to_load_queue(Name *n) {
assert(n);
if (n->meta.load_state != NAME_STUB || n->meta.in_load_queue)
return;
LIST_PREPEND(Meta, load_queue, n->meta.manager->load_queue, &n->meta);
n->meta.in_load_queue = true;
}
static void bidi_set_free(Name *name, Set *s) {
Iterator i;
Name *other;
assert(name);
/* Frees the set and makes sure we are dropped from the
* inverse pointers */
SET_FOREACH(other, s, i) {
NameDependency d;
for (d = 0; d < _NAME_DEPENDENCY_MAX; d++)
set_remove(other->meta.dependencies[d], name);
}
set_free(s);
}
void name_free(Name *name) {
NameDependency d;
Iterator i;
char *t;
assert(name);
/* Detach from next 'bigger' objects */
SET_FOREACH(t, name->meta.names, i)
hashmap_remove_value(name->meta.manager->names, t, name);
if (name->meta.in_load_queue)
LIST_REMOVE(Meta, load_queue, name->meta.manager->load_queue, &name->meta);
if (name->meta.load_state == NAME_LOADED)
if (NAME_VTABLE(name)->done)
NAME_VTABLE(name)->done(name);
/* Free data and next 'smaller' objects */
if (name->meta.job)
job_free(name->meta.job);
for (d = 0; d < _NAME_DEPENDENCY_MAX; d++)
bidi_set_free(name, name->meta.dependencies[d]);
free(name->meta.description);
while ((t = set_steal_first(name->meta.names)))
free(t);
set_free(name->meta.names);
free(name);
}
NameActiveState name_active_state(Name *name) {
assert(name);
if (name->meta.load_state != NAME_LOADED)
return NAME_INACTIVE;
return NAME_VTABLE(name)->active_state(name);
}
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 name_merge(Name *name, Name *other) {
int r;
NameDependency d;
assert(name);
assert(other);
assert(name->meta.manager == other->meta.manager);
/* This merges 'other' into 'name'. FIXME: This does not
* rollback on failure. */
if (name->meta.type != other->meta.type)
return -EINVAL;
if (other->meta.load_state != NAME_STUB)
return -EINVAL;
/* Merge names */
if ((r = ensure_merge(&name->meta.names, other->meta.names)) < 0)
return r;
/* Merge dependencies */
for (d = 0; d < _NAME_DEPENDENCY_MAX; d++)
/* fixme, the inverse mapping is missing */
if ((r = ensure_merge(&name->meta.dependencies[d], other->meta.dependencies[d])) < 0)
return r;
return 0;
}
const char* name_id(Name *n) {
assert(n);
if (n->meta.id)
return n->meta.id;
return set_first(n->meta.names);
}
const char *name_description(Name *n) {
assert(n);
if (n->meta.description)
return n->meta.description;
return name_id(n);
}
void name_dump(Name *n, FILE *f, const char *prefix) {
static const char* const load_state_table[_NAME_LOAD_STATE_MAX] = {
[NAME_STUB] = "stub",
[NAME_LOADED] = "loaded",
[NAME_FAILED] = "failed"
};
static const char* const active_state_table[_NAME_ACTIVE_STATE_MAX] = {
[NAME_ACTIVE] = "active",
[NAME_INACTIVE] = "inactive",
[NAME_ACTIVATING] = "activating",
[NAME_DEACTIVATING] = "deactivating"
};
static const char* const dependency_table[_NAME_DEPENDENCY_MAX] = {
[NAME_REQUIRES] = "Requires",
[NAME_SOFT_REQUIRES] = "SoftRequires",
[NAME_WANTS] = "Wants",
[NAME_REQUISITE] = "Requisite",
[NAME_SOFT_REQUISITE] = "SoftRequisite",
[NAME_REQUIRED_BY] = "RequiredBy",
[NAME_SOFT_REQUIRED_BY] = "SoftRequiredBy",
[NAME_WANTED_BY] = "WantedBy",
[NAME_CONFLICTS] = "Conflicts",
[NAME_BEFORE] = "Before",
[NAME_AFTER] = "After",
};
char *t;
NameDependency d;
Iterator i;
char *prefix2;
assert(n);
if (!prefix)
prefix = "";
prefix2 = strappend(prefix, "\t");
if (!prefix2)
prefix2 = "";
fprintf(f,
"%s→ Name %s:\n"
"%s\tDescription: %s\n"
"%s\tName Load State: %s\n"
"%s\tName Active State: %s\n",
prefix, name_id(n),
prefix, name_description(n),
prefix, load_state_table[n->meta.load_state],
prefix, active_state_table[name_active_state(n)]);
SET_FOREACH(t, n->meta.names, i)
fprintf(f, "%s\tName: %s\n", prefix, t);
for (d = 0; d < _NAME_DEPENDENCY_MAX; d++) {
Name *other;
if (set_isempty(n->meta.dependencies[d]))
continue;
SET_FOREACH(other, n->meta.dependencies[d], i)
fprintf(f, "%s\t%s: %s\n", prefix, dependency_table[d], name_id(other));
}
if (NAME_VTABLE(n)->dump)
NAME_VTABLE(n)->dump(n, f, prefix2);
if (n->meta.job)
job_dump(n->meta.job, f, prefix2);
free(prefix2);
}
static int verify_type(Name *name) {
char *n;
Iterator i;
assert(name);
/* Checks that all aliases of this name have the same and valid type */
SET_FOREACH(n, name->meta.names, i) {
NameType t;
if ((t = name_type_from_string(n)) == _NAME_TYPE_INVALID)
return -EINVAL;
if (name->meta.type == _NAME_TYPE_INVALID) {
name->meta.type = t;
continue;
}
if (name->meta.type != t)
return -EINVAL;
}
if (name->meta.type == _NAME_TYPE_INVALID)
return -EINVAL;
return 0;
}
/* Common implementation for multiple backends */
int name_load_fragment_and_dropin(Name *n) {
int r;
assert(n);
/* Load a .socket file */
if ((r = name_load_fragment(n)) < 0)
return r;
/* Load drop-in directory data */
if ((r = name_load_dropin(n)) < 0)
return r;
return 0;
}
int name_load(Name *name) {
int r;
assert(name);
if (name->meta.in_load_queue) {
LIST_REMOVE(Meta, load_queue, name->meta.manager->load_queue, &name->meta);
name->meta.in_load_queue = false;
}
if (name->meta.load_state != NAME_STUB)
return 0;
if ((r = verify_type(name)) < 0)
return r;
if (NAME_VTABLE(name)->init)
if ((r = NAME_VTABLE(name)->init(name)) < 0)
goto fail;
name->meta.load_state = NAME_LOADED;
return 0;
fail:
name->meta.load_state = NAME_FAILED;
return r;
}
/* Errors:
* -EBADR: This name type does not support starting.
* -EALREADY: Name is already started.
* -EAGAIN: An operation is already in progress. Retry later.
*/
int name_start(Name *n) {
NameActiveState state;
assert(n);
if (!NAME_VTABLE(n)->start)
return -EBADR;
state = name_active_state(n);
if (NAME_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 name is in some "auto
* restart" state where it waits for a holdoff timer to elapse
* before it will start again. */
return NAME_VTABLE(n)->start(n);
}
bool name_can_start(Name *n) {
assert(n);
return !!NAME_VTABLE(n)->start;
}
/* Errors:
* -EBADR: This name type does not support stopping.
* -EALREADY: Name is already stopped.
* -EAGAIN: An operation is already in progress. Retry later.
*/
int name_stop(Name *n) {
NameActiveState state;
assert(n);
if (!NAME_VTABLE(n)->stop)
return -EBADR;
state = name_active_state(n);
if (state == NAME_INACTIVE)
return -EALREADY;
if (state == NAME_DEACTIVATING)
return 0;
return NAME_VTABLE(n)->stop(n);
}
/* Errors:
* -EBADR: This name type does not support reloading.
* -ENOEXEC: Name is not started.
* -EAGAIN: An operation is already in progress. Retry later.
*/
int name_reload(Name *n) {
NameActiveState state;
assert(n);
if (!name_can_reload(n))
return -EBADR;
state = name_active_state(n);
if (name_active_state(n) == NAME_ACTIVE_RELOADING)
return -EALREADY;
if (name_active_state(n) != NAME_ACTIVE)
return -ENOEXEC;
return NAME_VTABLE(n)->reload(n);
}
bool name_can_reload(Name *n) {
assert(n);
if (!NAME_VTABLE(n)->reload)
return false;
if (!NAME_VTABLE(n)->can_reload)
return true;
return NAME_VTABLE(n)->can_reload(n);
}
static void retroactively_start_dependencies(Name *n) {
Iterator i;
Name *other;
assert(n);
assert(NAME_IS_ACTIVE_OR_ACTIVATING(name_active_state(n)));
SET_FOREACH(other, n->meta.dependencies[NAME_REQUIRES], i)
if (!NAME_IS_ACTIVE_OR_ACTIVATING(name_active_state(other)))
manager_add_job(n->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL);
SET_FOREACH(other, n->meta.dependencies[NAME_SOFT_REQUIRES], i)
if (!NAME_IS_ACTIVE_OR_ACTIVATING(name_active_state(other)))
manager_add_job(n->meta.manager, JOB_START, other, JOB_FAIL, false, NULL);
SET_FOREACH(other, n->meta.dependencies[NAME_REQUISITE], i)
if (!NAME_IS_ACTIVE_OR_ACTIVATING(name_active_state(other)))
manager_add_job(n->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL);
SET_FOREACH(other, n->meta.dependencies[NAME_WANTS], i)
if (!NAME_IS_ACTIVE_OR_ACTIVATING(name_active_state(other)))
manager_add_job(n->meta.manager, JOB_START, other, JOB_FAIL, false, NULL);
SET_FOREACH(other, n->meta.dependencies[NAME_CONFLICTS], i)
if (!NAME_IS_ACTIVE_OR_ACTIVATING(name_active_state(other)))
manager_add_job(n->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL);
}
static void retroactively_stop_dependencies(Name *n) {
Iterator i;
Name *other;
assert(n);
assert(NAME_IS_INACTIVE_OR_DEACTIVATING(name_active_state(n)));
SET_FOREACH(other, n->meta.dependencies[NAME_REQUIRED_BY], i)
if (!NAME_IS_INACTIVE_OR_DEACTIVATING(name_active_state(other)))
manager_add_job(n->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL);
}
void name_notify(Name *n, NameActiveState os, NameActiveState ns) {
assert(n);
assert(os < _NAME_ACTIVE_STATE_MAX);
assert(ns < _NAME_ACTIVE_STATE_MAX);
assert(!(os == NAME_ACTIVE && ns == NAME_ACTIVATING));
assert(!(os == NAME_INACTIVE && ns == NAME_DEACTIVATING));
if (os == ns)
return;
if (!NAME_IS_ACTIVE_OR_RELOADING(os) && NAME_IS_ACTIVE_OR_RELOADING(ns))
n->meta.active_enter_timestamp = now(CLOCK_REALTIME);
else if (NAME_IS_ACTIVE_OR_RELOADING(os) && !NAME_IS_ACTIVE_OR_RELOADING(ns))
n->meta.active_exit_timestamp = now(CLOCK_REALTIME);
if (n->meta.job) {
if (n->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(n->meta.job);
else {
assert(n->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 (n->meta.job->type) {
case JOB_START:
case JOB_VERIFY_ACTIVE:
if (NAME_IS_ACTIVE_OR_RELOADING(ns)) {
job_finish_and_invalidate(n->meta.job, true);
return;
} else if (ns == NAME_ACTIVATING)
return;
else
job_finish_and_invalidate(n->meta.job, false);
break;
case JOB_RELOAD:
case JOB_RELOAD_OR_START:
if (ns == NAME_ACTIVE) {
job_finish_and_invalidate(n->meta.job, true);
return;
} else if (ns == NAME_ACTIVATING || ns == NAME_ACTIVE_RELOADING)
return;
else
job_finish_and_invalidate(n->meta.job, false);
break;
case JOB_STOP:
case JOB_RESTART:
case JOB_TRY_RESTART:
if (ns == NAME_INACTIVE) {
job_finish_and_invalidate(n->meta.job, true);
return;
} else if (ns == NAME_DEACTIVATING)
return;
else
job_finish_and_invalidate(n->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 (NAME_IS_INACTIVE_OR_DEACTIVATING(os) && NAME_IS_ACTIVE_OR_ACTIVATING(ns))
retroactively_start_dependencies(n);
else if (NAME_IS_ACTIVE_OR_ACTIVATING(os) && NAME_IS_INACTIVE_OR_DEACTIVATING(ns))
retroactively_stop_dependencies(n);
}
int name_watch_fd(Name *n, int fd, uint32_t events) {
struct epoll_event ev;
assert(n);
assert(fd >= 0);
zero(ev);
ev.data.fd = fd;
ev.data.ptr = n;
ev.data.u32 = MANAGER_FD;
ev.events = events;
if (epoll_ctl(n->meta.manager->epoll_fd, EPOLL_CTL_ADD, fd, &ev) >= 0)
return 0;
if (errno == EEXIST)
if (epoll_ctl(n->meta.manager->epoll_fd, EPOLL_CTL_MOD, fd, &ev) >= 0)
return 0;
return -errno;
}
void name_unwatch_fd(Name *n, int fd) {
assert(n);
assert(fd >= 0);
assert_se(epoll_ctl(n->meta.manager->epoll_fd, EPOLL_CTL_DEL, fd, NULL) >= 0 || errno == ENOENT);
}
int name_watch_pid(Name *n, pid_t pid) {
assert(n);
assert(pid >= 1);
return hashmap_put(n->meta.manager->watch_pids, UINT32_TO_PTR(pid), n);
}
void name_unwatch_pid(Name *n, pid_t pid) {
assert(n);
assert(pid >= 1);
hashmap_remove(n->meta.manager->watch_pids, UINT32_TO_PTR(pid));
}
int name_watch_timer(Name *n, usec_t delay, int *id) {
struct epoll_event ev;
int fd;
struct itimerspec its;
int flags;
bool ours;
assert(n);
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 = n;
ev.data.u32 = MANAGER_TIMER;
ev.events = POLLIN;
if (epoll_ctl(n->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 name_unwatch_timer(Name *n, int *id) {
assert(n);
assert(id);
if (*id >= 0) {
assert_se(epoll_ctl(n->meta.manager->epoll_fd, EPOLL_CTL_DEL, *id, NULL) >= 0);
assert_se(close_nointr(*id) == 0);
*id = -1;
}
}
char *name_change_suffix(const char *t, const char *suffix) {
char *e, *n;
size_t a, b;
assert(t);
assert(name_is_valid(t));
assert(suffix);
assert_se(e = strrchr(t, '.'));
a = e - t;
b = strlen(suffix);
if (!(n = new(char, a + b + 1)))
return NULL;
memcpy(n, t, a);
memcpy(n+a, suffix, b+1);
return n;
}
bool name_job_is_applicable(Name *n, JobType j) {
assert(n);
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 name_can_start(n);
case JOB_RELOAD:
return name_can_reload(n);
case JOB_RELOAD_OR_START:
return name_can_reload(n) && name_can_start(n);
default:
assert_not_reached("Invalid job type");
}
}
int name_add_dependency(Name *n, NameDependency d, Name *other) {
static const NameDependency inverse_table[_NAME_DEPENDENCY_MAX] = {
[NAME_REQUIRES] = NAME_REQUIRED_BY,
[NAME_SOFT_REQUIRES] = NAME_SOFT_REQUIRED_BY,
[NAME_WANTS] = NAME_WANTED_BY,
[NAME_REQUISITE] = NAME_REQUIRED_BY,
[NAME_SOFT_REQUISITE] = NAME_SOFT_REQUIRED_BY,
[NAME_REQUIRED_BY] = _NAME_DEPENDENCY_INVALID,
[NAME_SOFT_REQUIRED_BY] = _NAME_DEPENDENCY_INVALID,
[NAME_WANTED_BY] = _NAME_DEPENDENCY_INVALID,
[NAME_CONFLICTS] = NAME_CONFLICTS,
[NAME_BEFORE] = NAME_AFTER,
[NAME_AFTER] = NAME_BEFORE
};
int r;
assert(n);
assert(d >= 0 && d < _NAME_DEPENDENCY_MAX);
assert(inverse_table[d] != _NAME_DEPENDENCY_INVALID);
assert(other);
if (n == other)
return 0;
if ((r = set_ensure_allocated(&n->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(n->meta.dependencies[d], other)) < 0)
return r;
if ((r = set_put(other->meta.dependencies[inverse_table[d]], n)) < 0) {
set_remove(n->meta.dependencies[d], other);
return r;
}
return 0;
}
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