syslog: rework syslog detection so that we need no compile-time option what the name of the syslog implementation is

4 files changed, 60 insertions, 18 deletions

diff --git a/src/manager.c b/src/manager.c
index 9edb8f09bb..a9aaee3d81 100644
--- a/src/manager.c
+++ b/src/manager.c
@@ -2451,6 +2451,12 @@ void manager_send_unit_audit(Manager *m, Unit *u, int type, bool success) {
         if (m->n_deserializing > 0)
                 return;
 
+        if (m->running_as != MANAGER_SYSTEM)
+                return;
+
+        if (u->meta.type != UNIT_SERVICE)
+                return;
+
         if (!(p = unit_name_to_prefix_and_instance(u->meta.id))) {
                 log_error("Failed to allocate unit name for audit message: %s", strerror(ENOMEM));
                 return;
@@ -2965,6 +2971,47 @@ int manager_set_default_controllers(Manager *m, char **controllers) {
         return 0;
 }
 
+void manager_recheck_syslog(Manager *m) {
+        Unit *u;
+
+        assert(m);
+
+        if (m->running_as != MANAGER_SYSTEM)
+                return;
+
+        if ((u = manager_get_unit(m, SPECIAL_SYSLOG_SOCKET))) {
+                SocketState state;
+
+                state = SOCKET(u)->state;
+
+                if (state != SOCKET_DEAD &&
+                    state != SOCKET_FAILED &&
+                    state != SOCKET_RUNNING) {
+
+                        /* Hmm, the socket is not set up, or is still
+                         * listening, let's better not try to use
+                         * it. Note that we have no problem if the
+                         * socket is completely down, since there
+                         * might be a foreign /dev/log socket around
+                         * and we want to make use of that.
+                         */
+
+                        log_close_syslog();
+                        return;
+                }
+        }
+
+        if ((u = manager_get_unit(m, SPECIAL_SYSLOG_TARGET)))
+                if (TARGET(u)->state != TARGET_ACTIVE) {
+                        log_close_syslog();
+                        return;
+                }
+
+        /* Hmm, OK, so the socket is either fully up, or fully down,
+         * and the target is up, then let's make use of the socket */
+        log_open();
+}
+
 static const char* const manager_running_as_table[_MANAGER_RUNNING_AS_MAX] = {
         [MANAGER_SYSTEM] = "system",
         [MANAGER_USER] = "user"
diff --git a/src/manager.h b/src/manager.h
index efca4ff7f6..c183e105af 100644
--- a/src/manager.h
+++ b/src/manager.h
@@ -285,6 +285,8 @@ void manager_check_finished(Manager *m);
 void manager_run_generators(Manager *m);
 void manager_undo_generators(Manager *m);
 
+void manager_recheck_syslog(Manager *m);
+
 const char *manager_running_as_to_string(ManagerRunningAs i);
 ManagerRunningAs manager_running_as_from_string(const char *s);
 
diff --git a/src/special.h b/src/special.h
index ba2bc143e0..6a75e2cf7d 100644
--- a/src/special.h
+++ b/src/special.h
@@ -24,21 +24,24 @@
 
 #define SPECIAL_DEFAULT_TARGET "default.target"
 
+/* Shutdown targets */
+#define SPECIAL_UMOUNT_TARGET "umount.target"
 /* This is not really intended to be started by directly. This is
  * mostly so that other targets (reboot/halt/poweroff) can depend on
  * it to bring all services down that want to be brought down on
  * system shutdown. */
 #define SPECIAL_SHUTDOWN_TARGET "shutdown.target"
-#define SPECIAL_UMOUNT_TARGET "umount.target"
 #define SPECIAL_HALT_TARGET "halt.target"
 #define SPECIAL_POWEROFF_TARGET "poweroff.target"
 #define SPECIAL_REBOOT_TARGET "reboot.target"
 #define SPECIAL_KEXEC_TARGET "kexec.target"
 #define SPECIAL_EXIT_TARGET "exit.target"
 
+/* Special boot targets */
 #define SPECIAL_RESCUE_TARGET "rescue.target"
 #define SPECIAL_EMERGENCY_TARGET "emergency.target"
 
+/* Early boot targets */
 #define SPECIAL_SYSINIT_TARGET "sysinit.target"
 #define SPECIAL_SOCKETS_TARGET "sockets.target"
 #define SPECIAL_LOCAL_FS_TARGET "local-fs.target"         /* LSB's $local_fs */
@@ -46,8 +49,8 @@
 #define SPECIAL_SWAP_TARGET "swap.target"
 #define SPECIAL_BASIC_TARGET "basic.target"
 
+/* LSB compatibility */
 #define SPECIAL_NETWORK_TARGET "network.target"           /* LSB's $network */
-
 #define SPECIAL_NSS_LOOKUP_TARGET "nss-lookup.target"     /* LSB's $named */
 #define SPECIAL_RPCBIND_TARGET "rpcbind.target"           /* LSB's $portmap */
 #define SPECIAL_SYSLOG_TARGET "syslog.target"             /* LSB's $syslog; Should pull in syslog.socket or syslog.service */
@@ -56,22 +59,22 @@
 #define SPECIAL_MAIL_TRANSFER_AGENT_TARGET "mail-transfer-agent.target" /* Debian's $mail-{transport|transfer-agent */
 #define SPECIAL_HTTP_DAEMON_TARGET "http-daemon.target"
 
+/* Magic early boot services */
 #define SPECIAL_FSCK_SERVICE "fsck@.service"
 #define SPECIAL_QUOTACHECK_SERVICE "quotacheck.service"
 #define SPECIAL_REMOUNT_ROOTFS_SERVICE "remount-rootfs.service"
 
+/* Services systemd relies on */
 #define SPECIAL_DBUS_SERVICE "dbus.service"
 #define SPECIAL_DBUS_SOCKET "dbus.socket"
 #define SPECIAL_LOGGER_SOCKET "systemd-logger.socket"
+#define SPECIAL_SYSLOG_SOCKET "syslog.socket"
 
+/* Magic init signals */
 #define SPECIAL_KBREQUEST_TARGET "kbrequest.target"
 #define SPECIAL_SIGPWR_TARGET "sigpwr.target"
 #define SPECIAL_CTRL_ALT_DEL_TARGET "ctrl-alt-del.target"
 
-#ifndef SPECIAL_SYSLOG_SERVICE
-#define SPECIAL_SYSLOG_SERVICE "syslog.service"
-#endif
-
 /* For SysV compatibility. Usually an alias for a saner target. On
  * SysV-free systems this doesn't exist. */
 #define SPECIAL_RUNLEVEL2_TARGET "runlevel2.target"
diff --git a/src/unit.c b/src/unit.c
index 10de40affc..6f10f51fbd 100644
--- a/src/unit.c
+++ b/src/unit.c
@@ -1224,12 +1224,6 @@ void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns, bool reload_su
                          * yet connected. */
                         bus_init(u->meta.manager, true);
 
-                if (unit_has_name(u, SPECIAL_SYSLOG_SERVICE))
-                        /* The syslog daemon just might have become
-                         * available, hence try to connect to it, if
-                         * we aren't yet connected. */
-                        log_open();
-
                 if (u->meta.type == UNIT_SERVICE &&
                     !UNIT_IS_ACTIVE_OR_RELOADING(os)) {
                         /* Write audit record if we have just finished starting up */
@@ -1242,12 +1236,6 @@ void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns, bool reload_su
 
         } else {
 
-                if (unit_has_name(u, SPECIAL_SYSLOG_SERVICE))
-                        /* The syslog daemon might just have
-                         * terminated, hence try to disconnect from
-                         * it. */
-                        log_close_syslog();
-
                 /* We don't care about D-Bus here, since we'll get an
                  * asynchronous notification for it anyway. */
 
@@ -1277,6 +1265,8 @@ void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns, bool reload_su
 
         unit_add_to_dbus_queue(u);
         unit_add_to_gc_queue(u);
+
+        manager_recheck_syslog(u->meta.manager);
 }
 
 int unit_watch_fd(Unit *u, int fd, uint32_t events, Watch *w) {