wait-until-removed: Add Interface parameter

The additional interface parameter can be a string
(ex. "intf" "obj1"), or be in a single string with
the obj parameter (ex. "intf obj1 obj2..."). The
latter is used when passing the parameters from
a systemd unit.
The wait-until-removed option will block until the
requested interface is not present in the specified
dbus object.

Change-Id: Ia935af5721e2aec8c271eff483cff9c3a1f1fa24
Signed-off-by: Adriana Kobylak <anoo@us.ibm.com>

3 files changed, 110 insertions, 4 deletions

diff --git a/libmapper/app.c b/libmapper/app.c
index aa42461..e4aea03 100644
--- a/libmapper/app.c
+++ b/libmapper/app.c
@@ -84,16 +84,57 @@ static void quit(int r, void *loop)
 	sd_event_exit((sd_event *)loop, r);
 }
 
+static char** split_args(char* arg)
+{
+	int i = 0;
+	int count = 0;
+	char* p = arg;
+
+	while((p = strchr(p, ' ')) != NULL) {
+		count++;
+		p++;
+	}
+	if (count == 0)
+		return NULL;
+
+	/* Need to allocate space for count+1 number of arguments */
+	count++;
+	char** args = (char**)malloc(sizeof(*args) * count);
+	if (args != NULL) {
+		i = 0;
+		p = strtok(arg, " ");
+		while((p != NULL) && (i < count)) {
+			args[i++] = p;
+			p = strtok(NULL, " ");
+		}
+	}
+
+	return args;
+}
+
 static int wait_main(int argc, char *argv[])
 {
 	int r;
+	bool free_args = false;
+	char** args = argv + 2;
 	sd_bus *conn = NULL;
 	sd_event *loop = NULL;
 	mapper_async_wait *wait = NULL;
 
-	if(argc < 3) {
+	if((!strcmp(argv[1], "wait")) && argc < 3) {
 		fprintf(stderr, "Usage: %s wait OBJECTPATH...\n", argv[0]);
 		exit(EXIT_FAILURE);
+	} else if((!strcmp(argv[1], "wait-until-removed")) && argc < 4) {
+		/* The arguments can be passed by a single string, ex: "intf obj1..." */
+		/* Try to split the single into the multiple arguments */
+		args = split_args(argv[2]);
+		if (args != NULL)
+			free_args = true;
+		else {
+			fprintf(stderr, "Usage: %s wait-until-removed \
+					INTERFACE OBJECTPATH...\n", argv[0]);
+			exit(EXIT_FAILURE);
+		}
 	}
 
 	r = sd_bus_default_system(&conn);
@@ -120,9 +161,11 @@ static int wait_main(int argc, char *argv[])
 	}
 
 	if (!strcmp(argv[1], "wait"))
-		r = mapper_wait_async(conn, loop, argv+2, quit, loop, &wait, true);
+		r = mapper_wait_async(conn, loop, NULL, args, quit, loop, &wait,
+				true);
 	else if (!strcmp(argv[1], "wait-until-removed"))
-		r = mapper_wait_async(conn, loop, argv+2, quit, loop, &wait, false);
+		r = mapper_wait_async(conn, loop, args[0], args+1, quit, loop, &wait,
+				false);
 	if(r < 0) {
 		fprintf(stderr, "Error configuring waitlist: %s\n",
 				strerror(-r));
@@ -137,6 +180,8 @@ static int wait_main(int argc, char *argv[])
 	}
 
 finish:
+	if (free_args)
+		free(args);
 	exit(r < 0 ? EXIT_FAILURE : EXIT_SUCCESS);
 }
 
diff --git a/libmapper/mapper.c b/libmapper/mapper.c
index ad64d4a..4f2d022 100644
--- a/libmapper/mapper.c
+++ b/libmapper/mapper.c
@@ -45,6 +45,7 @@ static const uint64_t mapper_busy_delay_interval_usec = 1000000;
 
 struct mapper_async_wait
 {
+	char *intf;
 	char **objs;
 	void (*callback)(int, void *);
 	void *userdata;
@@ -150,6 +151,49 @@ static int async_wait_timeout_callback(sd_event_source *s,
 	return 0;
 }
 
+static int get_interface(sd_bus_message *m,
+		mapper_async_wait *wait, char* interface)
+{
+	int r = 0;
+	char* tmp_intf = NULL;
+
+	for(int i = 0; i<wait->count; ++i) {
+		sd_bus_error error = SD_BUS_ERROR_NULL;
+		r = sd_bus_call_method(
+				wait->conn,
+				MAPPER_BUSNAME,
+				MAPPER_PATH,
+				MAPPER_INTERFACE,
+				"GetSubTreePaths",
+				&error,
+				&m,
+				"sias",
+				wait->objs[i],
+				0, 1,
+				wait->intf);
+		if (r < 0) {
+			fprintf(stderr, "Error invoking method: %s\n",
+					strerror(-r));
+			return r;
+		}
+
+		r = sd_bus_message_read(m, "as", 1, &tmp_intf);
+		if (r < 0) {
+			// Ignore the errno when the intf does not exist (ENXIO)
+			if (r == -ENXIO) {
+				r = 0;
+				continue;
+			}
+		} else
+			break;
+	}
+
+	if (tmp_intf)
+		strcpy(interface, tmp_intf);
+
+	return r;
+}
+
 static int async_wait_getobject_callback(sd_bus_message *m,
 		void *userdata,
 		sd_bus_error *e)
@@ -163,6 +207,18 @@ static int async_wait_getobject_callback(sd_bus_message *m,
 		goto exit;
 
 	r = sd_bus_message_get_errno(m);
+
+	if (!r && !wait->added) {
+		// Dbus object exists, need to check if it has the requested interface
+		char intf[256];
+		intf[0] = '\0';
+		r = get_interface(m, wait, intf);
+		if ((r < 0) || (strlen(intf) != 0))
+			goto exit;
+		else
+			r = 0;
+	}
+
 	if(r == ENOENT) {
 		if (wait->added)
 			goto exit;
@@ -303,6 +359,7 @@ void mapper_wait_async_free(mapper_async_wait *w)
 
 int mapper_wait_async(sd_bus *conn,
 		sd_event *loop,
+		const char *intf,
 		char *objs[],
 		void (*callback)(int, void *),
 		void *userdata,
@@ -325,6 +382,10 @@ int mapper_wait_async(sd_bus *conn,
 	if(!wait->count)
 		return 0;
 	wait->added = added;
+	if (intf != NULL)
+		wait->intf = strdup(intf);
+	else
+		wait->intf = NULL;
 
 	wait->objs = sarraydup(objs);
 	if(!wait->objs) {
diff --git a/libmapper/mapper.h b/libmapper/mapper.h
index 9f85c5f..b3fed6b 100644
--- a/libmapper/mapper.h
+++ b/libmapper/mapper.h
@@ -8,7 +8,7 @@ extern "C" {
 typedef struct mapper_async_wait mapper_async_wait;
 void mapper_wait_async_free(mapper_async_wait *);
 
-int mapper_wait_async(sd_bus *, sd_event *, char *[],
+int mapper_wait_async(sd_bus *, sd_event *, const char *, char *[],
 		void (*)(int, void *), void *, mapper_async_wait **,
 		bool);
 int mapper_get_service(sd_bus *conn, const char *obj, char **service);