Return-Path: From: Arman Uguray To: linux-bluetooth@vger.kernel.org Cc: Arman Uguray Subject: [PATCH BlueZ v1 01/11] shared/gatt-server: Implement "Read By Type" request. Date: Fri, 7 Nov 2014 12:41:49 -0800 Message-Id: <1415392919-17572-2-git-send-email-armansito@chromium.org> In-Reply-To: <1415392919-17572-1-git-send-email-armansito@chromium.org> References: <1415392919-17572-1-git-send-email-armansito@chromium.org> Sender: linux-bluetooth-owner@vger.kernel.org List-ID: This patch implements the ATT protocol "Read By Type" request for shared/gatt-server. Logic is implemented that allows asynchronous reading of non-standard attribute values via the registered read and read completion callbacks. --- src/shared/gatt-server.c | 246 ++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 243 insertions(+), 3 deletions(-) diff --git a/src/shared/gatt-server.c b/src/shared/gatt-server.c index 18f82c4..ddb0be1 100644 --- a/src/shared/gatt-server.c +++ b/src/shared/gatt-server.c @@ -40,6 +40,16 @@ #define MIN(a, b) ((a) < (b) ? (a) : (b)) #endif +struct async_read_op { + struct bt_gatt_server *server; + uint8_t opcode; + bool done; + uint8_t *pdu; + size_t pdu_len; + size_t value_len; + struct queue *db_data; +}; + struct bt_gatt_server { struct gatt_db *db; struct bt_att *att; @@ -48,6 +58,9 @@ struct bt_gatt_server { unsigned int mtu_id; unsigned int read_by_grp_type_id; + unsigned int read_by_type_id; + + struct async_read_op *pending_read_op; bt_gatt_server_debug_func_t debug_callback; bt_gatt_server_destroy_func_t debug_destroy; @@ -61,11 +74,23 @@ static void bt_gatt_server_free(struct bt_gatt_server *server) bt_att_unregister(server->att, server->mtu_id); bt_att_unregister(server->att, server->read_by_grp_type_id); + bt_att_unregister(server->att, server->read_by_type_id); bt_att_unref(server->att); + if (server->pending_read_op) + server->pending_read_op->server = NULL; + free(server); } +static uint8_t att_ecode_from_error(int err) +{ + if (err < 0 || err > UINT8_MAX) + return 0xff; + + return err; +} + static void encode_error_rsp(uint8_t opcode, uint16_t handle, uint8_t ecode, uint8_t pdu[4]) { @@ -136,14 +161,15 @@ static bool encode_read_by_grp_type_rsp(struct gatt_db *db, struct queue *q, * value is seen. */ if (iter == 0) { - data_val_len = value.iov_len; + data_val_len = MIN(MIN((unsigned)mtu - 6, 251), + value.iov_len); pdu[0] = data_val_len + 4; iter++; } else if (value.iov_len != data_val_len) break; /* Stop if this unit would surpass the MTU */ - if (iter + data_val_len + 4 > mtu) + if (iter + data_val_len + 4 > mtu - 1) break; gatt_db_attribute_get_service_handles(attrib, &start_handle, @@ -151,7 +177,7 @@ static bool encode_read_by_grp_type_rsp(struct gatt_db *db, struct queue *q, put_le16(start_handle, pdu + iter); put_le16(end_handle, pdu + iter + 2); - memcpy(pdu + iter + 4, value.iov_base, value.iov_len); + memcpy(pdu + iter + 4, value.iov_base, data_val_len); iter += data_val_len + 4; } @@ -248,6 +274,212 @@ done: NULL, NULL, NULL); } +static void async_read_op_destroy(struct async_read_op *op) +{ + if (op->server) + op->server->pending_read_op = NULL; + + queue_destroy(op->db_data, NULL); + free(op->pdu); + free(op); +} + +static void process_read_by_type(struct async_read_op *op); + +static void read_by_type_read_complete_cb(struct gatt_db_attribute *attr, + int err, const uint8_t *value, + size_t len, void *user_data) +{ + struct async_read_op *op = user_data; + struct bt_gatt_server *server = op->server; + uint16_t mtu; + uint16_t handle; + + if (!server) { + async_read_op_destroy(op); + return; + } + + mtu = bt_att_get_mtu(server->att); + handle = gatt_db_attribute_get_handle(attr); + + /* Terminate the operation if there was an error */ + if (err) { + uint8_t pdu[4]; + uint8_t att_ecode = att_ecode_from_error(err); + + encode_error_rsp(BT_ATT_OP_READ_BY_TYPE_REQ, handle, att_ecode, + pdu); + bt_att_send(server->att, BT_ATT_OP_ERROR_RSP, pdu, 4, NULL, + NULL, NULL); + async_read_op_destroy(op); + return; + } + + if (op->pdu_len == 0) { + op->value_len = MIN(MIN((unsigned) mtu - 4, 253), len); + op->pdu[0] = op->value_len + 2; + op->pdu_len++; + } else if (len != op->value_len) { + op->done = true; + goto done; + } + + /* Stop if this would surpass the MTU */ + if (op->pdu_len + op->value_len + 2 > (unsigned) mtu - 1) { + op->done = true; + goto done; + } + + /* Encode the current value */ + put_le16(handle, op->pdu + op->pdu_len); + memcpy(op->pdu + op->pdu_len + 2, value, op->value_len); + + op->pdu_len += op->value_len + 2; + + if (op->pdu_len == (unsigned) mtu - 1) + op->done = true; + +done: + process_read_by_type(op); +} + +static void process_read_by_type(struct async_read_op *op) +{ + struct bt_gatt_server *server = op->server; + uint8_t rsp_opcode; + uint8_t rsp_len; + uint8_t ecode; + uint16_t ehandle; + struct gatt_db_attribute *attr; + uint32_t perm; + + attr = queue_pop_head(op->db_data); + + if (op->done || !attr) { + rsp_opcode = BT_ATT_OP_READ_BY_TYPE_RSP; + rsp_len = op->pdu_len; + goto done; + } + + if (!gatt_db_attribute_get_permissions(attr, &perm)) { + ecode = BT_ATT_ERROR_UNLIKELY; + goto error; + } + + /* + * Check for the READ access permission. Encryption, + * authentication, and authorization permissions need to be + * checked by the read handler, since bt_att is agnostic to + * connection type and doesn't have security information on it. + */ + if (perm && !(perm & BT_ATT_PERM_READ)) { + ecode = BT_ATT_ERROR_READ_NOT_PERMITTED; + goto error; + } + + if (gatt_db_attribute_read(attr, 0, op->opcode, NULL, + read_by_type_read_complete_cb, op)) + return; + + ecode = BT_ATT_ERROR_UNLIKELY; + +error: + ehandle = gatt_db_attribute_get_handle(attr); + rsp_opcode = BT_ATT_OP_ERROR_RSP; + rsp_len = 4; + encode_error_rsp(BT_ATT_OP_READ_BY_TYPE_REQ, ehandle, ecode, op->pdu); + +done: + bt_att_send(server->att, rsp_opcode, op->pdu, rsp_len, NULL, + NULL, NULL); + async_read_op_destroy(op); +} + +static void read_by_type_cb(uint8_t opcode, const void *pdu, + uint16_t length, void *user_data) +{ + struct bt_gatt_server *server = user_data; + uint16_t start, end; + bt_uuid_t type; + uint8_t rsp_pdu[4]; + uint16_t ehandle = 0; + uint8_t ecode; + struct queue *q = NULL; + struct async_read_op *op; + + if (length != 6 && length != 20) { + ecode = BT_ATT_ERROR_INVALID_PDU; + goto error; + } + + q = queue_new(); + if (!q) { + ecode = BT_ATT_ERROR_INSUFFICIENT_RESOURCES; + goto error; + } + + start = get_le16(pdu); + end = get_le16(pdu + 2); + get_uuid_le(pdu + 4, length - 4, &type); + + util_debug(server->debug_callback, server->debug_data, + "Read By Type - start: 0x%04x end: 0x%04x", + start, end); + + if (!start || !end) { + ecode = BT_ATT_ERROR_INVALID_HANDLE; + goto error; + } + + ehandle = start; + + if (start > end) { + ecode = BT_ATT_ERROR_INVALID_HANDLE; + goto error; + } + + gatt_db_read_by_type(server->db, start, end, type, q); + + if (queue_isempty(q)) { + ecode = BT_ATT_ERROR_ATTRIBUTE_NOT_FOUND; + goto error; + } + + if (server->pending_read_op) { + ecode = BT_ATT_ERROR_UNLIKELY; + goto error; + } + + op = new0(struct async_read_op, 1); + if (!op) { + ecode = BT_ATT_ERROR_INSUFFICIENT_RESOURCES; + goto error; + } + + op->pdu = malloc(bt_att_get_mtu(server->att)); + if (!op->pdu) { + free(op); + ecode = BT_ATT_ERROR_INSUFFICIENT_RESOURCES; + goto error; + } + + op->opcode = opcode; + op->server = server; + op->db_data = q; + server->pending_read_op = op; + + process_read_by_type(op); + + return; + +error: + encode_error_rsp(opcode, ehandle, ecode, rsp_pdu); + queue_destroy(q, NULL); + bt_att_send(server->att, BT_ATT_OP_ERROR_RSP, rsp_pdu, 4, + NULL, NULL, NULL); +} + static void exchange_mtu_cb(uint8_t opcode, const void *pdu, uint16_t length, void *user_data) { @@ -296,6 +528,14 @@ static bool gatt_server_register_att_handlers(struct bt_gatt_server *server) if (!server->read_by_grp_type_id) return false; + /* Read By Type */ + server->read_by_type_id = bt_att_register(server->att, + BT_ATT_OP_READ_BY_TYPE_REQ, + read_by_type_cb, + server, NULL); + if (!server->read_by_type_id) + return false; + return true; } -- 2.1.0.rc2.206.gedb03e5