From e23ab2b9b3b21b9d856d94120d65083c38f6c27f Mon Sep 17 00:00:00 2001
From: Arman Uguray <armansito@chromium.org>
Date: Mon, 10 Nov 2014 09:07:19 -0800
Subject: [PATCH] shared/gatt-server: Implement "Write" request and command.

This patch implements the "Write" request and command for the GATT
server role. Writes are delegated to the attribute's write handler,
which is also responsible for performing certain permission checks.
---
 src/shared/gatt-server.c | 135 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 135 insertions(+)

diff --git a/src/shared/gatt-server.c b/src/shared/gatt-server.c
index ddb714dbd..34cab0561 100644
--- a/src/shared/gatt-server.c
+++ b/src/shared/gatt-server.c
@@ -50,6 +50,11 @@ struct async_read_op {
 	struct queue *db_data;
 };
 
+struct async_write_op {
+	struct bt_gatt_server *server;
+	uint8_t opcode;
+};
+
 struct bt_gatt_server {
 	struct gatt_db *db;
 	struct bt_att *att;
@@ -60,8 +65,11 @@ struct bt_gatt_server {
 	unsigned int read_by_grp_type_id;
 	unsigned int read_by_type_id;
 	unsigned int find_info_id;
+	unsigned int write_id;
+	unsigned int write_cmd_id;
 
 	struct async_read_op *pending_read_op;
+	struct async_write_op *pending_write_op;
 
 	bt_gatt_server_debug_func_t debug_callback;
 	bt_gatt_server_destroy_func_t debug_destroy;
@@ -77,10 +85,15 @@ static void bt_gatt_server_free(struct bt_gatt_server *server)
 	bt_att_unregister(server->att, server->read_by_grp_type_id);
 	bt_att_unregister(server->att, server->read_by_type_id);
 	bt_att_unregister(server->att, server->find_info_id);
+	bt_att_unregister(server->att, server->write_id);
+	bt_att_unregister(server->att, server->write_cmd_id);
 
 	if (server->pending_read_op)
 		server->pending_read_op->server = NULL;
 
+	if (server->pending_write_op)
+		server->pending_write_op->server = NULL;
+
 	bt_att_unref(server->att);
 	free(server);
 }
@@ -626,6 +639,114 @@ done:
 							NULL, NULL, NULL);
 }
 
+static void async_write_op_destroy(struct async_write_op *op)
+{
+	if (op->server)
+		op->server->pending_write_op = NULL;
+
+	free(op);
+}
+
+static void write_complete_cb(struct gatt_db_attribute *attr, int err,
+								void *user_data)
+{
+	struct async_write_op *op = user_data;
+	struct bt_gatt_server *server = op->server;
+	uint16_t handle;
+
+	if (!server || op->opcode == BT_ATT_OP_WRITE_CMD) {
+		async_write_op_destroy(op);
+		return;
+	}
+
+	handle = gatt_db_attribute_get_handle(attr);
+
+	if (err) {
+		uint8_t rsp_pdu[4];
+		uint8_t att_ecode = att_ecode_from_error(err);
+
+		encode_error_rsp(op->opcode, handle, att_ecode, rsp_pdu);
+		bt_att_send(server->att, BT_ATT_OP_ERROR_RSP, rsp_pdu, 4,
+							NULL, NULL, NULL);
+	} else {
+		bt_att_send(server->att, BT_ATT_OP_WRITE_RSP, NULL, 0,
+							NULL, NULL, NULL);
+	}
+
+	async_write_op_destroy(op);
+}
+
+static void write_cb(uint8_t opcode, const void *pdu,
+					uint16_t length, void *user_data)
+{
+	struct bt_gatt_server *server = user_data;
+	struct gatt_db_attribute *attr;
+	uint16_t handle = 0;
+	uint8_t rsp_pdu[4];
+	struct async_write_op *op = NULL;
+	uint8_t ecode;
+	uint32_t perm;
+
+	if (length < 2) {
+		ecode = BT_ATT_ERROR_INVALID_PDU;
+		goto error;
+	}
+
+	handle = get_le16(pdu);
+	attr = gatt_db_get_attribute(server->db, handle);
+	if (!attr) {
+		ecode = BT_ATT_ERROR_INVALID_HANDLE;
+		goto error;
+	}
+
+	util_debug(server->debug_callback, server->debug_data,
+				"Write %s - handle: 0x%04x",
+				(opcode == BT_ATT_OP_WRITE_REQ) ? "Req" : "Cmd",
+				handle);
+
+	if (!gatt_db_attribute_get_permissions(attr, &perm)) {
+		ecode = BT_ATT_ERROR_INVALID_HANDLE;
+		goto error;
+	}
+
+	if (!(perm & BT_ATT_PERM_WRITE)) {
+		ecode = BT_ATT_ERROR_WRITE_NOT_PERMITTED;
+		goto error;
+	}
+
+	if (server->pending_write_op) {
+		ecode = BT_ATT_ERROR_UNLIKELY;
+		goto error;
+	}
+
+	op = new0(struct async_write_op, 1);
+	if (!op) {
+		ecode = BT_ATT_ERROR_INSUFFICIENT_RESOURCES;
+		goto error;
+	}
+
+	op->server = server;
+	op->opcode = opcode;
+	server->pending_write_op = op;
+
+	if (gatt_db_attribute_write(attr, 0, pdu + 2, length - 2, opcode,
+						NULL, write_complete_cb, op))
+		return;
+
+	if (op)
+		async_write_op_destroy(op);
+
+	ecode = BT_ATT_ERROR_UNLIKELY;
+
+error:
+	if (opcode == BT_ATT_OP_WRITE_CMD)
+		return;
+
+	encode_error_rsp(opcode, handle, ecode, rsp_pdu);
+	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)
 {
@@ -690,6 +811,20 @@ static bool gatt_server_register_att_handlers(struct bt_gatt_server *server)
 	if (!server->find_info_id)
 		return false;
 
+	/* Write Request */
+	server->write_id = bt_att_register(server->att, BT_ATT_OP_WRITE_REQ,
+								write_cb,
+								server, NULL);
+	if (!server->write_id)
+		return false;
+
+	/* Write Command */
+	server->write_cmd_id = bt_att_register(server->att, BT_ATT_OP_WRITE_CMD,
+								write_cb,
+								server, NULL);
+	if (!server->write_cmd_id)
+		return false;
+
 	return true;
 }
 
-- 
2.47.3