shared/gatt-client: Introduce struct bt_gatt_characteristic_iter.

shared/gatt-client currently defines a service iterator which returns service
data in a copy. The user then accesses the service's characteristics by manually
going through an array of bt_gatt_characteristic_t.

This patch changes this by restricting access to individual characteristic
entries via a new characteristic iterator. This is done so that gatt-client code
can internally store private data on each characteristic (e.g. reference count
for notification sessions) which shouldn't be exposed to external code.

The code also changes the service iterator functions to return a pointer to an
internally stored bt_gatt_service_t structure rather than returning its contents
in a copy.

1 files changed, 18 insertions, 13 deletions

diff --git a/tools/btgatt-client.c b/tools/btgatt-client.c
index d1395b25d..8bde1eeac 100644
--- a/tools/btgatt-client.c
+++ b/tools/btgatt-client.c
@@ -169,16 +169,21 @@ static void print_uuid(const uint8_t uuid[16])
 
 static void print_service(const bt_gatt_service_t *service)
 {
+	struct bt_gatt_characteristic_iter iter;
 	const bt_gatt_characteristic_t *chrc;
-	size_t i, j;
+	size_t i;
+
+	if (!bt_gatt_characteristic_iter_init(&iter, service)) {
+		PRLOG("Failed to initialize characteristic iterator\n");
+		return;
+	}
 
 	printf(COLOR_RED "service" COLOR_OFF " - start: 0x%04x, "
 				"end: 0x%04x, uuid: ",
 				service->start_handle, service->end_handle);
 	print_uuid(service->uuid);
 
-	for (i = 0; i < service->num_chrcs; i++) {
-		chrc = service->chrcs + i;
+	while (bt_gatt_characteristic_iter_next(&iter, &chrc)) {
 		printf("\t  " COLOR_YELLOW "charac" COLOR_OFF
 				" - start: 0x%04x, end: 0x%04x, "
 				"value: 0x%04x, props: 0x%02x, uuid: ",
@@ -186,13 +191,13 @@ static void print_service(const bt_gatt_service_t *service)
 				chrc->end_handle,
 				chrc->value_handle,
 				chrc->properties);
-		print_uuid(service->chrcs[i].uuid);
+		print_uuid(chrc->uuid);
 
-		for (j = 0; j < chrc->num_descs; j++) {
+		for (i = 0; i < chrc->num_descs; i++) {
 			printf("\t\t  " COLOR_MAGENTA "descr" COLOR_OFF
 						" - handle: 0x%04x, uuid: ",
-						chrc->descs[j].handle);
-			print_uuid(chrc->descs[j].uuid);
+						chrc->descs[i].handle);
+			print_uuid(chrc->descs[i].uuid);
 		}
 	}
 
@@ -202,7 +207,7 @@ static void print_service(const bt_gatt_service_t *service)
 static void print_services(struct client *cli)
 {
 	struct bt_gatt_service_iter iter;
-	bt_gatt_service_t service;
+	const bt_gatt_service_t *service;
 
 	if (!bt_gatt_service_iter_init(&iter, cli->gatt)) {
 		PRLOG("Failed to initialize service iterator\n");
@@ -212,13 +217,13 @@ static void print_services(struct client *cli)
 	printf("\n");
 
 	while (bt_gatt_service_iter_next(&iter, &service))
-		print_service(&service);
+		print_service(service);
 }
 
 static void print_services_by_uuid(struct client *cli, const bt_uuid_t *uuid)
 {
 	struct bt_gatt_service_iter iter;
-	bt_gatt_service_t service;
+	const bt_gatt_service_t *service;
 
 	if (!bt_gatt_service_iter_init(&iter, cli->gatt)) {
 		PRLOG("Failed to initialize service iterator\n");
@@ -229,13 +234,13 @@ static void print_services_by_uuid(struct client *cli, const bt_uuid_t *uuid)
 
 	while (bt_gatt_service_iter_next_by_uuid(&iter, uuid->value.u128.data,
 								&service))
-		print_service(&service);
+		print_service(service);
 }
 
 static void print_services_by_handle(struct client *cli, uint16_t handle)
 {
 	struct bt_gatt_service_iter iter;
-	bt_gatt_service_t service;
+	const bt_gatt_service_t *service;
 
 	if (!bt_gatt_service_iter_init(&iter, cli->gatt)) {
 		PRLOG("Failed to initialize service iterator\n");
@@ -245,7 +250,7 @@ static void print_services_by_handle(struct client *cli, uint16_t handle)
 	printf("\n");
 
 	while (bt_gatt_service_iter_next_by_handle(&iter, handle, &service))
-		print_service(&service);
+		print_service(service);
 }
 
 static void ready_cb(bool success, uint8_t att_ecode, void *user_data)