lib: Create API for GATT service discovery

2 files changed, 118 insertions, 2 deletions

diff --git a/lib/ble.c b/lib/ble.c
index d859cc4..8a46283 100644
--- a/lib/ble.c
+++ b/lib/ble.c
@@ -37,6 +37,9 @@ struct ble_device {
     bt_bdaddr_t bda;
     int conn_id;
 
+    btgatt_srvc_id_t *srvcs;
+    uint8_t srvc_count;
+
     ble_device_t *next;
 };
 
@@ -277,6 +280,76 @@ int ble_remove_bond(const uint8_t *address) {
     return ble_pair_internal(address, 2);
 }
 
+static ble_device_t *find_device_by_conn_id(int conn_id) {
+    ble_device_t *dev;
+
+    for (dev = data.devices; dev ; dev = dev->next)
+        if (dev->conn_id == conn_id)
+            break;
+
+    return dev;
+}
+
+static int find_service(ble_device_t *dev, btgatt_srvc_id_t *srvc_id) {
+    int id;
+
+    for (id = 0; id < dev->srvc_count; id++)
+        if (!memcmp(&dev->srvcs[id], srvc_id, sizeof(btgatt_srvc_id_t)))
+            return id;
+
+    return -1;
+}
+
+/* Called when the service discovery finishes */
+void service_discovery_complete_cb(int conn_id, int status) {
+    if (data.cbs.srvc_finished_cb)
+        data.cbs.srvc_finished_cb(conn_id, status);
+}
+
+/* Called for each service discovery result */
+void service_discovery_result_cb(int conn_id, btgatt_srvc_id_t *srvc_id) {
+    int id;
+    ble_device_t *dev;
+
+    dev = find_device_by_conn_id(conn_id);
+    if (!dev)
+        return;
+
+    id = find_service(dev, srvc_id);
+    if (id < 0) {
+        id = dev->srvc_count++;
+        dev->srvcs = realloc(dev->srvcs,
+                             dev->srvc_count * sizeof(btgatt_srvc_id_t));
+        memcpy(&dev->srvcs[id], srvc_id, sizeof(btgatt_srvc_id_t));
+    }
+
+    if (data.cbs.srvc_found_cb)
+        data.cbs.srvc_found_cb(conn_id, id, srvc_id->id.uuid.uu,
+                               srvc_id->is_primary);
+}
+
+int ble_gatt_discover_services(int conn_id, const uint8_t *uuid) {
+    bt_status_t s;
+    bt_uuid_t uu, *u = NULL;
+
+    if (conn_id <= 0)
+        return -1;
+
+    if (!data.gattiface)
+        return -1;
+
+    if (uuid) {
+        memcpy(uu.uu, uuid, 16 * sizeof(uint8_t));
+        u = &uu;
+    }
+
+    s = data.gattiface->client->search_service(conn_id, u);
+    if (s != BT_STATUS_SUCCESS)
+        return -s;
+
+    return 0;
+}
+
 /* Called when the client registration is finished */
 static void register_client_cb(int status, int client_if, bt_uuid_t *app_uuid) {
     if (status == BT_STATUS_SUCCESS) {
@@ -293,8 +366,8 @@ static const btgatt_client_callbacks_t gattccbs = {
     scan_result_cb,
     connect_cb,
     disconnect_cb,
-    NULL, /* search_complete_cb */
-    NULL, /* search_result_cb */
+    service_discovery_complete_cb,
+    service_discovery_result_cb,
     NULL, /* get_characteristic_cb */
     NULL, /* get_descriptor_cb */
     NULL, /* get_included_service_cb */
@@ -418,7 +491,10 @@ static void remove_all_devices() {
     dev = data.devices;
     while (dev) {
         next = dev->next;
+
+        free(dev->srvcs);
         free(dev);
+
         dev = next;
     }
 }
diff --git a/lib/ble.h b/lib/ble.h
index 6f75801..738e89d 100644
--- a/lib/ble.h
+++ b/lib/ble.h
@@ -106,6 +106,30 @@ typedef void (*ble_bond_state_cb_t)(const uint8_t *address,
                                     ble_bond_state_t state, int status);
 
 /**
+ * Type that represents a callback function to notify of a new GATT element
+ * (service, characteristic or descriptor) found in a BLE device.
+ *
+ * @param conn_id The identifier of the connected remote device.
+ * @param id ID of the service, characteristic or descriptor.
+ * @param uuid A pointer to a 16 element array representing each part of the
+ *             service, characteristic or descriptor UUID.
+ * @param props Additional element properties. For services, whether the service
+ *              is primary or not: 1 primary, 0 included. Always zero for other
+ *              GATT elements.
+ */
+typedef void (*ble_gatt_found_cb_t)(int conn_id, int id, const uint8_t *uuid,
+                                    int props);
+
+/**
+ * Type that represents a callback function to notify that a GATT operation has
+ * finished.
+ *
+ * @param conn_id The identifier of the connected remote device.
+ * @param status The status in which the operation has finished.
+ */
+typedef void (*ble_gatt_finished_cb_t)(int conn_id, int status);
+
+/**
  * List of callbacks for BLE operations.
  */
 typedef struct ble_cbs {
@@ -115,6 +139,8 @@ typedef struct ble_cbs {
     ble_connect_cb_t connect_cb;
     ble_connect_cb_t disconnect_cb;
     ble_bond_state_cb_t bond_state_cb;
+    ble_gatt_found_cb_t srvc_found_cb;
+    ble_gatt_finished_cb_t srvc_finished_cb;
 } ble_cbs_t;
 
 /**
@@ -219,4 +245,18 @@ int ble_cancel_pairing(const uint8_t *address);
  * @return -1 if failed to remove bond.
  */
 int ble_remove_bond(const uint8_t *address);
+
+/**
+ * Discover services in a BLE device.
+ *
+ * There should be an active connection with the device.
+ *
+ * @param conn_id The identifier of the connected remote device.
+ * @param uuid Service UUID: if not NULL then only services with this UUID will
+ *             be notified.
+ *
+ * @return 0 if service discovery has been successfully requested.
+ * @return -1 if failed to request service discovery.
+ */
+int ble_gatt_discover_services(int conn_id, const uint8_t *uuid);
 #endif