Allow to remove systemd library

This change allows to compile a binder
that doesn't use libsystemd.

The restriction implied is that the neither
the systemd event loop nor the systemd dbus
facilities are availables. Consequently,
the dbus transparancy of APIs isn't available.

Also the work isn't fully complete because
afb-ws-client doesn't handle the removal of
libsystemd.

A more general work still have to be made to
allow the binder to run as library using an
external event loop.

Change-Id: I27a80862868b9c5a0453011a1d8aa3ce75cb5f6e
Signed-off-by: Jose Bollo <jose.bollo@iot.bzh>

15 files changed, 250 insertions, 63 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index da8fe366..f5c6d2ae 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -40,6 +40,8 @@ INCLUDE(CTest)
 # possible settings
 
 option(AGL_DEVEL                   "Activates developping features" OFF)
+option(WITH_SYSTEMD                "Require use of libsystemd"      ON)
+
 option(INCLUDE_MONITORING          "Activates installation of monitoring" OFF)
 
 option(INCLUDE_SUPERVISOR          "Activates installation of supervisor" OFF)
@@ -101,8 +103,10 @@ IF(cynara_FOUND)
 	ADD_DEFINITIONS(-DBACKEND_PERMISSION_IS_CYNARA)
 ENDIF(cynara_FOUND)
 
+IF(NOT libsystemd_FOUND AND NOT WITH_SYSTEMD)
+  set(libsystemd_FOUND 1)
+ENDIF()
 IF(HAVE_LIBMAGIC AND libsystemd_FOUND AND libmicrohttpd_FOUND AND openssl_FOUND AND uuid_FOUND)
-  ADD_DEFINITIONS(-DUSE_MAGIC_MIME_TYPE)
 ELSE()
   IF(NOT HAVE_LIBMAGIC)
     MESSAGE(WARNING "\"magic.h\" or \"libmagic.so\" missing.
@@ -125,6 +129,7 @@ ELSE()
   ENDIF()
 ENDIF()
 
+ADD_DEFINITIONS(-DUSE_MAGIC_MIME_TYPE)
 ADD_DEFINITIONS(-DAFB_VERSION="${PROJECT_VERSION}")
 
 INCLUDE_DIRECTORIES(
diff --git a/coverage/bin/Makefile b/coverage/bin/Makefile
index c0581693..222d265a 100644
--- a/coverage/bin/Makefile
+++ b/coverage/bin/Makefile
@@ -60,7 +60,7 @@ ldflags = -ldl -lrt -lpthread \
 
 cflags = $(ccflags) $(ldflags)
 
-defs = 	-DAGL_DEVEL \
+defs = 	-DAGL_DEVE=1L \
 	-DWITH_MONITORING_OPTION \
 	-DAFB_VERSION=\"cov\" \
 	-DUSE_SIG_MONITOR_DUMPSTACK=1 \
@@ -69,9 +69,17 @@ defs = 	-DAGL_DEVEL \
 	-DUSE_SIG_MONITOR_TIMERS=1 \
 	-DWITH_AFB_HOOK=1 \
 	-DWITH_AFB_TRACE=1 \
+	-DWITH_LEGACY_BINDING_V1=0 \
+	-DWITH_LEGACY_BINDING_V2=1 \
+	-DWITH_LEGACY_BINDING_VDYN=0 \
+	-DWITH_DBUS_TRANSPARENCY=0 \
+	-DWITH_SUPERVISION=0 \
+	-DWITH_DYNAMIC_BINDING=1 \
+	-DWITH_SYSTEMD=0 \
+	-DWITH_FDEV_EPOLL=1 \
 	-DBINDING_INSTALL_DIR=\"$(shell pwd)/fake\"
 
-afb_lib_src = $(shell ls $(srcdir)/*.c | egrep -v '/afs-|/main-|/fdev-epoll.c|/afb-ws-client.c' )
+afb_lib_src = $(shell ls $(srcdir)/*.c | egrep -v '/afs-|/main-|/afb-ws-client.c' )
 afb_lib_obj = $(patsubst $(srcdir)/%.c,%.o,$(afb_lib_src))
 afb_lib = afb-lib.a
 afb_lib_defs = $(defs)
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 71cd1ff2..64a8d973 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -66,6 +66,8 @@ add_definitions(
   -DWITH_DBUS_TRANSPARENCY=$<BOOL:${INCLUDE_DBUS_TRANSPARENCY}>
   -DWITH_SUPERVISION=$<BOOL:${INCLUDE_SUPERVISOR}>
   -DWITH_DYNAMIC_BINDING=$<BOOL:${WITH_DYNAMIC_BINDING}>
+  -DWITH_SYSTEMD=$<BOOL:${WITH_SYSTEMD}>
+  -DWITH_FDEV_EPOLL=$<NOT:$<BOOL:${WITH_SYSTEMD}>>
 )
 ############################################################################
 
diff --git a/src/afb-export.c b/src/afb-export.c
index 8ebe8e06..202a73f6 100644
--- a/src/afb-export.c
+++ b/src/afb-export.c
@@ -50,7 +50,9 @@
 #include "afb-xreq.h"
 #include "afb-calls.h"
 
+#if WITH_SYSTEMD
 #include "systemd.h"
+#endif
 #include "jobs.h"
 #include "verbose.h"
 #include "globset.h"
@@ -312,20 +314,35 @@ static int event_broadcast_cb(struct afb_api_x3 *closure, const char *name, stru
 
 static struct sd_event *get_event_loop(struct afb_api_x3 *closure)
 {
+#if WITH_SYSTEMD
 	jobs_acquire_event_manager();
 	return systemd_get_event_loop();
+#else
+	errno = ENOTSUP;
+	return NULL;
+#endif
 }
 
 static struct sd_bus *get_user_bus(struct afb_api_x3 *closure)
 {
+#if WITH_SYSTEMD
 	jobs_acquire_event_manager();
 	return systemd_get_user_bus();
+#else
+	errno = ENOTSUP;
+	return NULL;
+#endif
 }
 
 static struct sd_bus *get_system_bus(struct afb_api_x3 *closure)
 {
+#if WITH_SYSTEMD
 	jobs_acquire_event_manager();
 	return systemd_get_system_bus();
+#else
+	errno = ENOTSUP;
+	return NULL;
+#endif
 }
 
 static int rootdir_open_locale_cb(struct afb_api_x3 *closure, const char *filename, int flags, const char *locale)
@@ -481,7 +498,6 @@ static struct sd_event *hooked_get_event_loop(struct afb_api_x3 *closure)
 	struct afb_export *export = from_api_x3(closure);
 	struct sd_event *r;
 
-	jobs_acquire_event_manager();
 	r = get_event_loop(closure);
 	return afb_hook_api_get_event_loop(export, r);
 }
@@ -491,7 +507,6 @@ static struct sd_bus *hooked_get_user_bus(struct afb_api_x3 *closure)
 	struct afb_export *export = from_api_x3(closure);
 	struct sd_bus *r;
 
-	jobs_acquire_event_manager();
 	r = get_user_bus(closure);
 	return afb_hook_api_get_user_bus(export, r);
 }
@@ -501,7 +516,6 @@ static struct sd_bus *hooked_get_system_bus(struct afb_api_x3 *closure)
 	struct afb_export *export = from_api_x3(closure);
 	struct sd_bus *r;
 
-	jobs_acquire_event_manager();
 	r = get_system_bus(closure);
 	return afb_hook_api_get_system_bus(export, r);
 }
diff --git a/src/afb-fdev.c b/src/afb-fdev.c
index a5f95660..e98d39d2 100644
--- a/src/afb-fdev.c
+++ b/src/afb-fdev.c
@@ -15,9 +15,12 @@
  * limitations under the License.
  */
 
+#include "evmgr.h"
 #include "fdev.h"
-
 #include "jobs.h"
+
+#if WITH_SYSTEMD
+
 #include "systemd.h"
 #include "fdev-systemd.h"
 
@@ -26,3 +29,17 @@ struct fdev *afb_fdev_create(int fd)
 	jobs_acquire_event_manager();
 	return fdev_systemd_create(systemd_get_event_loop(), fd);
 }
+
+#endif
+#if WITH_FDEV_EPOLL
+
+#include "evmgr.h"
+#include "fdev-epoll.h"
+
+struct fdev *afb_fdev_create(int fd)
+{
+	struct evmgr *evmgr = jobs_acquire_event_manager();
+	return fdev_epoll_add(evmgr_get_fdev_epoll(evmgr), fd);
+}
+
+#endif
diff --git a/src/afb-socket.c b/src/afb-socket.c
index cf788de6..754baea0 100644
--- a/src/afb-socket.c
+++ b/src/afb-socket.c
@@ -32,10 +32,13 @@
 #include "afb-fdev.h"
 #include "afb-socket.h"
 
-#include "systemd.h"
 #include "fdev.h"
 #include "verbose.h"
 
+#if WITH_SYSTEMD
+#include "systemd.h"
+#endif
+
 #define BACKLOG  5
 
 /******************************************************************************/
@@ -225,11 +228,11 @@ static int open_tcp(const char *spec, int server, int reuseaddr)
  */
 static int open_systemd(const char *spec)
 {
-#if defined(NO_SYSTEMD_ACTIVATION)
+#if WITH_SYSTEMD
+	return systemd_fds_for(spec);
+#else
 	errno = EAFNOSUPPORT;
 	return -1;
-#else
-	return systemd_fds_for(spec);
 #endif
 }
 
diff --git a/src/evmgr.c b/src/evmgr.c
index 2dc35e42..d26502df 100644
--- a/src/evmgr.c
+++ b/src/evmgr.c
@@ -33,20 +33,92 @@
 
 #include "evmgr.h"
 #include "verbose.h"
+
+#if WITH_SYSTEMD
 #include "systemd.h"
+#else
+#include "fdev-epoll.h"
+#include "fdev.h"
+#endif
 
 /** Description of handled event loops */
 struct evmgr
 {
-	unsigned state;        /**< encoded state */
 	int efd;               /**< event notification */
+	unsigned state;        /**< encoded state */
 	void *holder;          /**< holder of the evmgr */
+#if WITH_SYSTEMD
 	struct sd_event *sdev; /**< the systemd event loop */
+#endif
+#if WITH_FDEV_EPOLL
+	struct fdev_epoll *fdev_epoll;
+	struct fdev *fdev;
+#endif
 };
 
 #define EVLOOP_STATE_WAIT           1U
 #define EVLOOP_STATE_RUN            2U
 
+
+/**
+ * Internal callback for evmgr management.
+ * The effect of this function is hidden: it exits
+ * the waiting poll if any.
+ */
+static void evmgr_on_efd_event(struct evmgr *evmgr)
+{
+	uint64_t x;
+	read(evmgr->efd, &x, sizeof x);
+}
+
+/**
+ * wakeup the event loop if needed by sending
+ * an event.
+ */
+void evmgr_wakeup(struct evmgr *evmgr)
+{
+	uint64_t x;
+
+	if (evmgr->state & EVLOOP_STATE_WAIT) {
+		x = 1;
+		write(evmgr->efd, &x, sizeof x);
+	}
+}
+
+/**
+ */
+void *evmgr_holder(struct evmgr *evmgr)
+{
+	return evmgr->holder;
+}
+
+/**
+ */
+int evmgr_release_if(struct evmgr *evmgr, void *holder)
+{
+	if (evmgr->holder != holder)
+		return 0;
+	evmgr->holder = 0;
+	return 1;
+}
+
+/**
+ */
+int evmgr_try_hold(struct evmgr *evmgr, void *holder)
+{
+	if (!evmgr->holder)
+		evmgr->holder = holder;
+	return evmgr->holder == holder;
+}
+
+/******************************************************************************/
+/******************************************************************************/
+/******  SYSTEM D                                                        ******/
+/******************************************************************************/
+/******************************************************************************/
+
+#if WITH_SYSTEMD
+
 /**
  * Run the event loop is set.
  */
@@ -98,59 +170,101 @@ int evmgr_can_run(struct evmgr *evmgr)
 /**
  * Internal callback for evmgr management.
  * The effect of this function is hidden: it exits
- * the waiting poll if any.
+ * the waiting poll if any. Then it wakes up a thread
+ * awaiting the evmgr using signal.
  */
-static void evmgr_on_efd_event(struct evmgr *evmgr)
+static int on_evmgr_efd(sd_event_source *s, int fd, uint32_t revents, void *userdata)
 {
-	uint64_t x;
-	read(evmgr->efd, &x, sizeof x);
+	struct evmgr *evmgr = userdata;
+	evmgr_on_efd_event(evmgr);
+	return 1;
 }
 
 /**
- * wakeup the event loop if needed by sending
- * an event.
+ * Gets a sd_event item for the current thread.
+ * @return a sd_event or NULL in case of error
  */
-void evmgr_wakeup(struct evmgr *evmgr)
+int evmgr_create(struct evmgr **result)
 {
-	uint64_t x;
+	int rc;
+	struct evmgr *evmgr;
 
-	if (evmgr->state & EVLOOP_STATE_WAIT) {
-		x = 1;
-		write(evmgr->efd, &x, sizeof x);
+	/* creates the evmgr on need */
+	evmgr = malloc(sizeof *evmgr);
+	if (!evmgr) {
+		ERROR("out of memory");
+		rc = -ENOMEM;
+		goto error;
+	}
+
+	/* creates the eventfd for waking up polls */
+	evmgr->efd = eventfd(0, EFD_CLOEXEC|EFD_SEMAPHORE);
+	if (evmgr->efd < 0) {
+		ERROR("can't make eventfd for events");
+		rc = -errno;
+		goto error1;
 	}
+	/* create the systemd event loop */
+	evmgr->sdev = systemd_get_event_loop();
+	if (!evmgr->sdev) {
+		ERROR("can't make new event loop");
+		goto error2;
+	}
+	/* put the eventfd in the event loop */
+	rc = sd_event_add_io(evmgr->sdev, NULL, evmgr->efd, EPOLLIN, on_evmgr_efd, evmgr);
+	if (rc < 0) {
+		ERROR("can't register eventfd");
+		goto error2;
+	}
+
+	/* start the creation */
+	evmgr->state = 0;
+	evmgr->holder = 0;
+	*result = evmgr;
+	return 0;
+
+
+error2:
+	close(evmgr->efd);
+error1:
+	free(evmgr);
+error:
+	*result = 0;
+	return rc;
 }
 
+#endif
+#if WITH_FDEV_EPOLL
+
 /**
+ * Run the event loop is set.
  */
-void *evmgr_holder(struct evmgr *evmgr)
+void evmgr_run(struct evmgr *evmgr)
 {
-	return evmgr->holder;
+	int rc;
+
+	evmgr->state = EVLOOP_STATE_WAIT|EVLOOP_STATE_RUN;
+	rc = fdev_epoll_wait_and_dispatch(evmgr->fdev_epoll, -1);
+	evmgr->state = 0;
 }
 
-/**
- */
-int evmgr_release_if(struct evmgr *evmgr, void *holder)
+void evmgr_job_run(int signum, struct evmgr *evmgr)
 {
-	if (evmgr->holder != holder)
-		return 0;
-	evmgr->holder = 0;
-	return 1;
+	if (signum)
+		evmgr->state = 0;
+	else
+		evmgr_run(evmgr);
 }
 
-/**
- */
-int evmgr_try_hold(struct evmgr *evmgr, void *holder)
+int evmgr_can_run(struct evmgr *evmgr)
 {
-	if (!evmgr->holder)
-		evmgr->holder = holder;
-	return evmgr->holder == holder;
+	return !evmgr->state;
 }
 
-/******************************************************************************/
-/******************************************************************************/
-/******  SYSTEM D                                                        ******/
-/******************************************************************************/
-/******************************************************************************/
+struct fdev_epoll *evmgr_get_fdev_epoll(struct evmgr *evmgr)
+{
+	return evmgr->fdev_epoll;
+}
 
 /**
  * Internal callback for evmgr management.
@@ -158,11 +272,10 @@ int evmgr_try_hold(struct evmgr *evmgr, void *holder)
  * the waiting poll if any. Then it wakes up a thread
  * awaiting the evmgr using signal.
  */
-static int on_evmgr_efd(sd_event_source *s, int fd, uint32_t revents, void *userdata)
+static void on_evmgr_efd(void *closure, uint32_t event, struct fdev *fdev)
 {
-	struct evmgr *evmgr = userdata;
+	struct evmgr *evmgr = closure;
 	evmgr_on_efd_event(evmgr);
-	return 1;
 }
 
 /**
@@ -189,19 +302,23 @@ int evmgr_create(struct evmgr **result)
 		rc = -errno;
 		goto error1;
 	}
+
 	/* create the systemd event loop */
-	evmgr->sdev = systemd_get_event_loop();
-	if (!evmgr->sdev) {
+	evmgr->fdev_epoll = fdev_epoll_create();
+	if (!evmgr->fdev_epoll) {
 		ERROR("can't make new event loop");
 		goto error2;
 	}
 	/* put the eventfd in the event loop */
-	rc = sd_event_add_io(evmgr->sdev, NULL, evmgr->efd, EPOLLIN, on_evmgr_efd, evmgr);
-	if (rc < 0) {
-		ERROR("can't register eventfd");
-		goto error2;
+	evmgr->fdev = fdev_epoll_add(evmgr->fdev_epoll, evmgr->efd);
+	if (evmgr->fdev == NULL) {
+		ERROR("can't add eventfd");
+		goto error3;
 	}
 
+	fdev_set_callback(evmgr->fdev, on_evmgr_efd, evmgr);
+	fdev_set_events(evmgr->fdev, EPOLLIN);
+
 	/* start the creation */
 	evmgr->state = 0;
 	evmgr->holder = 0;
@@ -209,6 +326,8 @@ int evmgr_create(struct evmgr **result)
 	return 0;
 
 
+error3:
+	fdev_epoll_destroy(evmgr->fdev_epoll);
 error2:
 	close(evmgr->efd);
 error1:
@@ -218,3 +337,4 @@ error:
 	return rc;
 }
 
+#endif
diff --git a/src/evmgr.h b/src/evmgr.h
index c78ea33f..e7af226f 100644
--- a/src/evmgr.h
+++ b/src/evmgr.h
@@ -28,3 +28,8 @@ extern int evmgr_release_if(struct evmgr *evmgr, void *holder);
 extern int evmgr_try_hold(struct evmgr *evmgr, void *holder);
 extern void *evmgr_holder(struct evmgr *evmgr);
 extern int evmgr_create(struct evmgr **result);
+
+#if WITH_FDEV_EPOLL
+struct fdev_epoll;
+extern struct fdev_epoll *evmgr_get_fdev_epoll(struct evmgr *evmgr);
+#endif
diff --git a/src/fdev-systemd.h b/src/fdev-systemd.h
index 2d573efe..ee46186a 100644
--- a/src/fdev-systemd.h
+++ b/src/fdev-systemd.h
@@ -21,3 +21,4 @@ struct fdev;
 struct sd_event;
 
 extern struct fdev *fdev_systemd_create(struct sd_event *eloop, int fd);
+
diff --git a/src/jobs.c b/src/jobs.c
index 936c6f1d..4a9ce188 100644
--- a/src/jobs.c
+++ b/src/jobs.c
@@ -22,20 +22,14 @@
 #include <unistd.h>
 #include <signal.h>
 #include <string.h>
-#include <time.h>
-#include <sys/syscall.h>
 #include <pthread.h>
 #include <errno.h>
 #include <assert.h>
-#include <sys/eventfd.h>
-
-#include <systemd/sd-event.h>
 
 #include "jobs.h"
 #include "evmgr.h"
 #include "sig-monitor.h"
 #include "verbose.h"
-#include "systemd.h"
 
 #define EVENT_TIMEOUT_TOP  	((uint64_t)-1)
 #define EVENT_TIMEOUT_CHILD	((uint64_t)10000)
@@ -715,7 +709,7 @@ int jobs_call(
 /**
  * Ensure that the current running thread can control the event loop.
  */
-void jobs_acquire_event_manager()
+struct evmgr *jobs_acquire_event_manager()
 {
 	struct thread lt;
 
@@ -755,6 +749,7 @@ void jobs_acquire_event_manager()
 		evloop_release();
 		current_thread = NULL;
 	}
+	return evmgr;
 }
 
 /**
diff --git a/src/jobs.h b/src/jobs.h
index 4b0fa8bb..60ee383f 100644
--- a/src/jobs.h
+++ b/src/jobs.h
@@ -18,6 +18,7 @@
 #pragma once
 
 struct jobloop;
+struct evmgr;
 
 extern int jobs_queue(
 		const void *group,
@@ -46,6 +47,6 @@ extern int jobs_start(
 		void (*start)(int signum, void* arg),
 		void *arg);
 
-extern void jobs_acquire_event_manager();
+extern struct evmgr *jobs_acquire_event_manager();
 
 extern void jobs_exit(void (*handler)());
diff --git a/src/main-afb-daemon.c b/src/main-afb-daemon.c
index d825d803..705c69f9 100644
--- a/src/main-afb-daemon.c
+++ b/src/main-afb-daemon.c
@@ -36,7 +36,9 @@
 
 #include <json-c/json.h>
 
-#include <systemd/sd-daemon.h>
+#if WITH_SYSTEMD
+#   include <systemd/sd-daemon.h>
+#endif
 
 #include "afb-args.h"
 #include "afb-hswitch.h"
@@ -885,7 +887,9 @@ static void start(int signum, void *arg)
 		goto error;
 
 	/* ready */
+#if WITH_SYSTEMD
 	sd_notify(1, "READY=1");
+#endif
 
 	/* activate the watchdog */
 #if HAS_WATCHDOG
diff --git a/src/systemd.c b/src/systemd.c
index 29d626bc..747e6a83 100644
--- a/src/systemd.c
+++ b/src/systemd.c
@@ -15,6 +15,8 @@
  * limitations under the License.
  */
 
+#if WITH_SYSTEMD
+
 #define _GNU_SOURCE
 
 #include <unistd.h>
@@ -113,3 +115,4 @@ int systemd_fds_for(const char *name)
 	return -1;
 }
 
+#endif
diff --git a/src/systemd.h b/src/systemd.h
index d9efa352..0fadfa7d 100644
--- a/src/systemd.h
+++ b/src/systemd.h
@@ -17,6 +17,8 @@
 
 #pragma once
 
+#if WITH_SYSTEMD
+
 struct sd_event;
 struct sd_bus;
 
@@ -27,4 +29,4 @@ extern struct sd_bus *systemd_get_system_bus();
 extern int systemd_fds_init();
 extern int systemd_fds_for(const char *name);
 
-
+#endif
diff --git a/src/watchdog.c b/src/watchdog.c
index 92144ba0..1aa9a51e 100644
--- a/src/watchdog.c
+++ b/src/watchdog.c
@@ -23,19 +23,26 @@
 
 #include <stdlib.h>
 
+#include "jobs.h"
+
+#if WITH_SYSTEMD
+
 #include <systemd/sd-event.h>
 #include <systemd/sd-daemon.h>
 
-#include "jobs.h"
 #include "systemd.h"
 
+#endif
+
 int watchdog_activate()
 {
+#if WITH_SYSTEMD
 	/* set the watchdog */
 	if (sd_watchdog_enabled(0, NULL)) {
 		jobs_acquire_event_manager();
 		sd_event_set_watchdog(systemd_get_event_loop(), 1);
 	}
+#endif
 	return 0;
 }