make utmp/wtmp support configurable

This adds --disable-utmp option to configure. If it is used, all
utmp-related functionality, including querying runlevel support,
is removed.

7 files changed, 87 insertions, 19 deletions

diff --git a/Makefile-man.am b/Makefile-man.am
index bd5306e676..2b3fa95e70 100644
--- a/Makefile-man.am
+++ b/Makefile-man.am
@@ -23,7 +23,6 @@ MANPAGES += \
 	man/machine-id.5 \
 	man/machine-info.5 \
 	man/os-release.5 \
-	man/runlevel.8 \
 	man/sd-daemon.3 \
 	man/sd-id128.3 \
 	man/sd-journal.3 \
@@ -93,7 +92,6 @@ MANPAGES += \
 	man/systemd-tty-ask-password-agent.1 \
 	man/systemd-udevd.service.8 \
 	man/systemd-update-done.service.8 \
-	man/systemd-update-utmp.service.8 \
 	man/systemd.1 \
 	man/systemd.automount.5 \
 	man/systemd.device.5 \
@@ -227,8 +225,6 @@ MANPAGES_ALIAS += \
 	man/systemd-udevd-kernel.socket.8 \
 	man/systemd-udevd.8 \
 	man/systemd-update-done.8 \
-	man/systemd-update-utmp-runlevel.service.8 \
-	man/systemd-update-utmp.8 \
 	man/systemd-user.conf.5
 man/SD_ALERT.3: man/sd-daemon.3
 man/SD_CRIT.3: man/sd-daemon.3
@@ -334,8 +330,6 @@ man/systemd-udevd-control.socket.8: man/systemd-udevd.service.8
 man/systemd-udevd-kernel.socket.8: man/systemd-udevd.service.8
 man/systemd-udevd.8: man/systemd-udevd.service.8
 man/systemd-update-done.8: man/systemd-update-done.service.8
-man/systemd-update-utmp-runlevel.service.8: man/systemd-update-utmp.service.8
-man/systemd-update-utmp.8: man/systemd-update-utmp.service.8
 man/systemd-user.conf.5: man/systemd-system.conf.5
 man/SD_ALERT.html: man/sd-daemon.html
 	$(html-alias)
@@ -649,12 +643,6 @@ man/systemd-udevd.html: man/systemd-udevd.service.html
 man/systemd-update-done.html: man/systemd-update-done.service.html
 	$(html-alias)
 
-man/systemd-update-utmp-runlevel.service.html: man/systemd-update-utmp.service.html
-	$(html-alias)
-
-man/systemd-update-utmp.html: man/systemd-update-utmp.service.html
-	$(html-alias)
-
 man/systemd-user.conf.html: man/systemd-system.conf.html
 	$(html-alias)
 
@@ -1509,6 +1497,23 @@ MANPAGES_ALIAS += \
 
 endif
 
+if HAVE_UTMP
+MANPAGES += \
+	man/runlevel.8 \
+	man/systemd-update-utmp.service.8
+MANPAGES_ALIAS += \
+	man/systemd-update-utmp-runlevel.service.8 \
+	man/systemd-update-utmp.8
+man/systemd-update-utmp-runlevel.service.8: man/systemd-update-utmp.service.8
+man/systemd-update-utmp.8: man/systemd-update-utmp.service.8
+man/systemd-update-utmp-runlevel.service.html: man/systemd-update-utmp.service.html
+	$(html-alias)
+
+man/systemd-update-utmp.html: man/systemd-update-utmp.service.html
+	$(html-alias)
+
+endif
+
 # Really, do not edit this file.
 
 EXTRA_DIST += \
diff --git a/Makefile.am b/Makefile.am
index 0f54c5c014..e0cba76329 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -378,7 +378,6 @@ rootlibexec_PROGRAMS = \
 	systemd \
 	systemd-cgroups-agent \
 	systemd-initctl \
-	systemd-update-utmp \
 	systemd-shutdownd \
 	systemd-shutdown \
 	systemd-remount-fs \
@@ -391,6 +390,11 @@ rootlibexec_PROGRAMS = \
 	systemd-socket-proxyd \
 	systemd-update-done
 
+if HAVE_UTMP
+rootlibexec_PROGRAMS += \
+	systemd-update-utmp
+endif
+
 systemgenerator_PROGRAMS = \
 	systemd-getty-generator \
 	systemd-fstab-generator \
@@ -517,8 +521,6 @@ nodist_systemunit_DATA = \
 	units/systemd-initctl.service \
 	units/systemd-shutdownd.service \
 	units/systemd-remount-fs.service \
-	units/systemd-update-utmp.service \
-	units/systemd-update-utmp-runlevel.service \
 	units/systemd-ask-password-wall.service \
 	units/systemd-ask-password-console.service \
 	units/systemd-sysctl.service \
@@ -544,6 +546,12 @@ nodist_systemunit_DATA = \
 	units/systemd-nspawn@.service \
 	units/systemd-update-done.service
 
+if HAVE_UTMP
+nodist_systemunit_DATA += \
+	units/systemd-update-utmp.service \
+	units/systemd-update-utmp-runlevel.service
+endif
+
 dist_userunit_DATA = \
 	units/user/basic.target \
 	units/user/default.target \
@@ -804,7 +812,6 @@ libsystemd_shared_la_SOURCES = \
 	src/shared/cgroup-show.h \
 	src/shared/unit-name.c \
 	src/shared/unit-name.h \
-	src/shared/utmp-wtmp.c \
 	src/shared/utmp-wtmp.h \
 	src/shared/watchdog.c \
 	src/shared/watchdog.h \
@@ -878,6 +885,11 @@ libsystemd_shared_la_SOURCES = \
 	src/shared/switch-root.c \
 	src/shared/nss-util.h
 
+if HAVE_UTMP
+libsystemd_shared_la_SOURCES += \
+	src/shared/utmp-wtmp.c
+endif
+
 nodist_libsystemd_shared_la_SOURCES = \
 	src/shared/errno-from-name.h \
 	src/shared/errno-to-name.h \
@@ -5856,6 +5868,7 @@ SOCKETS_TARGET_WANTS += \
 	systemd-initctl.socket \
 	systemd-shutdownd.socket
 
+if HAVE_UTMP
 if HAVE_SYSV_COMPAT
 RUNLEVEL1_TARGET_WANTS += \
 	systemd-update-utmp-runlevel.service
@@ -5870,7 +5883,10 @@ RUNLEVEL5_TARGET_WANTS += \
 endif
 
 SYSINIT_TARGET_WANTS += \
-	systemd-update-utmp.service \
+	systemd-update-utmp.service
+endif
+
+SYSINIT_TARGET_WANTS += \
 	systemd-update-done.service
 
 LOCAL_FS_TARGET_WANTS += \
diff --git a/configure.ac b/configure.ac
index 84644e163f..e33c8f75ac 100644
--- a/configure.ac
+++ b/configure.ac
@@ -346,6 +346,16 @@ AS_IF([test "x$enable_dbus" != "xno"], [
 AM_CONDITIONAL(HAVE_DBUS, [test "$have_dbus" = "yes"])
 
 # ------------------------------------------------------------------------------
+have_utmp=yes
+AC_ARG_ENABLE([utmp], AS_HELP_STRING([--disable-utmp], [disable utmp/wtmp log handling]),
+        AS_CASE("x${enableval}",
+                [xyes], [have_utmp=yes],
+                [xno],  [have_utmp=no],
+                AC_MSG_ERROR(bad value ${enableval} for --enable-utmp)))
+AS_IF([test "x$have_utmp" = "xyes"], [AC_DEFINE(HAVE_UTMP, 1, [Define if utmp/wtmp support is enabled])])
+AM_CONDITIONAL([HAVE_UTMP], [test "x$have_utmp" = "xyes"])
+
+# ------------------------------------------------------------------------------
 have_compat_libs=no
 AC_ARG_ENABLE([compat_libs], AS_HELP_STRING([--enable-compat-libs],[Enable creation of compatibility libraries]),
                 [case "${enableval}" in
@@ -1372,6 +1382,7 @@ AC_MSG_RESULT([
         Split /usr:              ${enable_split_usr}
         SysV compatibility:      ${SYSTEM_SYSV_COMPAT}
         compatibility libraries: ${have_compat_libs}
+        utmp/wtmp support:       ${have_utmp}
 
         prefix:                  ${prefix}
         rootprefix:              ${with_rootprefix}
diff --git a/man/runlevel.xml b/man/runlevel.xml
index 976753a737..db9a436724 100644
--- a/man/runlevel.xml
+++ b/man/runlevel.xml
@@ -22,7 +22,8 @@
 -->
 
 <refentry id="runlevel"
-          xmlns:xi="http://www.w3.org/2001/XInclude">
+          xmlns:xi="http://www.w3.org/2001/XInclude"
+          conditional="HAVE_UTMP">
 
         <refentryinfo>
                 <title>runlevel</title>
diff --git a/man/systemd-update-utmp.service.xml b/man/systemd-update-utmp.service.xml
index 7d9e32e60a..caa1d8f568 100644
--- a/man/systemd-update-utmp.service.xml
+++ b/man/systemd-update-utmp.service.xml
@@ -19,7 +19,7 @@
   You should have received a copy of the GNU Lesser General Public License
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 -->
-<refentry id="systemd-update-utmp.service">
+<refentry id="systemd-update-utmp.service" conditional="HAVE_UTMP">
 
         <refentryinfo>
                 <title>systemd-update-utmp.service</title>
diff --git a/src/core/build.h b/src/core/build.h
index a7f12a33e4..d5e55506cf 100644
--- a/src/core/build.h
+++ b/src/core/build.h
@@ -63,6 +63,12 @@
 #define _SYSVINIT_FEATURE_ "-SYSVINIT"
 #endif
 
+#ifdef HAVE_UTMP
+#define _UTMP_FEATURE_ "+UTMP"
+#else
+#define _UTMP_FEATURE_ "-UTMP"
+#endif
+
 #ifdef HAVE_LIBCRYPTSETUP
 #define _LIBCRYPTSETUP_FEATURE_ "+LIBCRYPTSETUP"
 #else
@@ -137,6 +143,7 @@
         _APPARMOR_FEATURE_ " "                                          \
         _SMACK_FEATURE_ " "                                             \
         _SYSVINIT_FEATURE_ " "                                          \
+        _UTMP_FEATURE_ " "                                              \
         _LIBCRYPTSETUP_FEATURE_ " "                                     \
         _GCRYPT_FEATURE_ " "                                            \
         _GNUTLS_FEATURE_ " "                                            \
diff --git a/src/shared/utmp-wtmp.h b/src/shared/utmp-wtmp.h
index 040a16e746..87d004e615 100644
--- a/src/shared/utmp-wtmp.h
+++ b/src/shared/utmp-wtmp.h
@@ -23,6 +23,7 @@
 
 #include "util.h"
 
+#ifdef HAVE_UTMP
 int utmp_get_runlevel(int *runlevel, int *previous);
 
 int utmp_put_shutdown(void);
@@ -33,3 +34,30 @@ int utmp_put_dead_process(const char *id, pid_t pid, int code, int status);
 int utmp_put_init_process(const char *id, pid_t pid, pid_t sid, const char *line);
 
 int utmp_wall(const char *message, const char *username, bool (*match_tty)(const char *tty));
+
+#else /* HAVE_UTMP */
+
+static inline int utmp_get_runlevel(int *runlevel, int *previous) {
+        return -ESRCH;
+}
+static inline int utmp_put_shutdown(void) {
+        return 0;
+}
+static inline int utmp_put_reboot(usec_t timestamp) {
+        return 0;
+}
+static inline int utmp_put_runlevel(int runlevel, int previous) {
+        return 0;
+}
+static inline int utmp_put_dead_process(const char *id, pid_t pid, int code, int status) {
+        return 0;
+}
+static inline int utmp_put_init_process(const char *id, pid_t pid, pid_t sid, const char *line) {
+        return 0;
+}
+static inline int utmp_wall(const char *message, const char *username,
+                bool (*match_tty)(const char *tty)) {
+        return 0;
+}
+
+#endif /* HAVE_UTMP */