userdbd: modernize signal handling

Let's make use of SD_EVENT_SIGNAL_PROCMASK so that we don't have to mask
the signals manually. Let's use sd_event_set_exit_signal() instead of
rolling our own SIGTERM/SIGINT handling. Let's use "floating" event
sources instead of keeping references on our own.

Let's also debug log if we can't enable watchdog handling.

3 files changed, 8 insertions, 16 deletions

diff --git a/src/userdb/userdbd-manager.c b/src/userdb/userdbd-manager.c
index 997ef83f57..81f327ef2e 100644
--- a/src/userdb/userdbd-manager.c
+++ b/src/userdb/userdbd-manager.c
@@ -95,15 +95,11 @@ int manager_new(Manager **ret) {
         if (r < 0)
                 return r;
 
-        r = sd_event_add_signal(m->event, NULL, SIGINT, NULL, NULL);
+        r = sd_event_set_signal_exit(m->event, true);
         if (r < 0)
                 return r;
 
-        r = sd_event_add_signal(m->event, NULL, SIGTERM, NULL, NULL);
-        if (r < 0)
-                return r;
-
-        r = sd_event_add_signal(m->event, NULL, SIGRTMIN+18, sigrtmin18_handler, NULL);
+        r = sd_event_add_signal(m->event, NULL, (SIGRTMIN+18)|SD_EVENT_SIGNAL_PROCMASK, sigrtmin18_handler, NULL);
         if (r < 0)
                 return r;
 
@@ -111,7 +107,9 @@ int manager_new(Manager **ret) {
         if (r < 0)
                 log_debug_errno(r, "Failed allocate memory pressure event source, ignoring: %m");
 
-        (void) sd_event_set_watchdog(m->event, true);
+        r = sd_event_set_watchdog(m->event, true);
+        if (r < 0)
+                log_debug_errno(r, "Failed to enable watchdog handling, ignoring: %m");
 
         m->workers_fixed = set_new(NULL);
         m->workers_dynamic = set_new(NULL);
@@ -119,11 +117,11 @@ int manager_new(Manager **ret) {
         if (!m->workers_fixed || !m->workers_dynamic)
                 return -ENOMEM;
 
-        r = sd_event_add_signal(m->event, &m->sigusr2_event_source, SIGUSR2, on_sigusr2, m);
+        r = sd_event_add_signal(m->event, NULL, SIGUSR2|SD_EVENT_SIGNAL_PROCMASK, on_sigusr2, m);
         if (r < 0)
                 return r;
 
-        r = sd_event_add_signal(m->event, &m->sigchld_event_source, SIGCHLD, on_sigchld, m);
+        r = sd_event_add_signal(m->event, NULL, SIGCHLD|SD_EVENT_SIGNAL_PROCMASK, on_sigchld, m);
         if (r < 0)
                 return r;
 
@@ -138,9 +136,6 @@ Manager* manager_free(Manager *m) {
         set_free(m->workers_fixed);
         set_free(m->workers_dynamic);
 
-        sd_event_source_disable_unref(m->sigusr2_event_source);
-        sd_event_source_disable_unref(m->sigchld_event_source);
-
         sd_event_unref(m->event);
 
         return mfree(m);
diff --git a/src/userdb/userdbd-manager.h b/src/userdb/userdbd-manager.h
index 35931da4c0..4fb45e6c35 100644
--- a/src/userdb/userdbd-manager.h
+++ b/src/userdb/userdbd-manager.h
@@ -18,9 +18,6 @@ struct Manager {
         Set *workers_fixed;    /* Workers 0…USERDB_WORKERS_MIN */
         Set *workers_dynamic;  /* Workers USERD_WORKERS_MIN+1…USERDB_WORKERS_MAX */
 
-        sd_event_source *sigusr2_event_source;
-        sd_event_source *sigchld_event_source;
-
         int listen_fd;
 
         RateLimit worker_ratelimit;
diff --git a/src/userdb/userdbd.c b/src/userdb/userdbd.c
index 2bf37a52c4..89ac9c7ba9 100644
--- a/src/userdb/userdbd.c
+++ b/src/userdb/userdbd.c
@@ -37,7 +37,7 @@ static int run(int argc, char *argv[]) {
         if (setenv("SYSTEMD_BYPASS_USERDB", "io.systemd.NameServiceSwitch:io.systemd.Multiplexer:io.systemd.DropIn", 1) < 0)
                 return log_error_errno(errno, "Failed to set $SYSTEMD_BYPASS_USERDB: %m");
 
-        assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGCHLD, SIGTERM, SIGINT, SIGUSR2, SIGRTMIN+18, -1) >= 0);
+        assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGCHLD, -1) >= 0);
 
         r = manager_new(&m);
         if (r < 0)